Popular Science Monthly 1927-07: Vol 111 Iss 1

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Doing the kind of work that a fine tool does Why do slowly by hand what a Millers Falls Electric Drill does so much easier, quicker and better? This fine, power- ful tool bites through any material without laying against it—wood, steel, building tile, cement, all the same. You can’t do by hand the quality of work that you get with this electric tool. If you always want to be sure of the standard of work that a fine tool produces, better drop in at the hardware store where you trade and “heft” this Millers Falls drill. It is light but strongly made, with a fine balance which any good judge of tools will know at once. Specifications: Portable Electric Drill No. 414 MOTOR, Universal—operates on D. C., or efficiently ventilated + Pig-tail brushes {not on A. C., up to 60 cycles * SPEED, No load usually found in drills of this size}, easily 1800 R. P. M. 1.2 Amps * CAPACITY, 0-% replaced from outside without taking in. in steel, 0-% in. in cast iron, 0-% in. in tool apart + Grease lubrication through- wood + Furnished for 110 or 220 volts « Jacobs out + 8 feet best quality rubber covered heavy duty chuck > Heat treated alloy steel cord furnished ~ Spindle offset for close gears’ Ball thrust bearing on spindle - Arma- boring —'% in. from outside of hous- ture mounted on high grade ball bearings .« ing + Weight 5% lbs. net + Overall Automatic switch mounted in handle - Ar- length 12 in. * Packed one in a heavy cor- mored attachment plug: Aluminum housing rugated box + PRICE + 110 Volts, $30.00. MILLERS FALLS MILLERS FALLS, MASS. CHICAGO, 9 SOUTH CLINTON STREET MILLERS FALLS COMPANY NEW YORK, 28 WARREN STREET

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.SS. EET POPULAR SCIENCE MONTHLY Moi? Table of Contents Index to the issues from JULY TO DECEMBER 1927

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POPULAR SCIENCE MONTHLY July, WHAT IS NEW THIS MONTH Table of Contents for July LEADING ARTICLES Wrretess Powrr—Tue Next Great INVENTION By Alden P. Armagnac Will radio and earth currents soon run the — s engines? How Fioops CHALLENGE ScIENCcE ;, By Edgar C. Wheeler What science has learned from a great disaster Tue Larcest PackaGe Ever SHIPpep . The story of a remarkable engineering feat Cannep Foop anp Your HEALTH . By Thomas M. Johnson An informative article on the diet question Srocx Cars Trestep tn Reat Races By Joseph S. Edgerton How speed trials point the way to better automobiles A New Era or Huce Brinces ; . By Orville H. Kneen A famous engineer tells why men now can build mile-long spans Counters THat Never Far . By Jack O’ Donnell Why the tireless homing pigeon is man’s valued friend Wuat Game Do You Piay?. . . .. . By Arthur Grahame A discussion of the “danger age” in sports BRONCHO-BUSTERS OF THE AIR . What happens when a test pilot tries ‘out a new plane GLENN Curtiss SEES A VISION OF AVIATION’S FuTuRE . Reported by Frank Parker Stockbridge Startling’ predictions by a pioneer birdman Uncte Sam’s Toy Coat Mine ; Where Government scientists test mining hazards | By Cy Caldwell By M. E. Clements His Strance Woritp CAME TRUE. . By Don Knowlton How modern wonders vindicate Jules Verne’s amazing prophecies Sam Loyp’s Puzz_e Pace Is Your Houses Too Hort or Cotp? New discoveries about the uses of insulation Stop THE Noises in Your Car Gus and Joe tell how to trace rattles and squeaks Tue ApvANTAGE or Group MANAGEMENT TO THE Pusuic Utiuity INVESTOR . By Wallace Ames Wauart Is a Goop Keene? . By Carlos de Zafra FICTION By John R. McMahon ‘ By Martin Bunn Curer or BaTTraLion . By Karl W. Detzer The thrills and science of fire-fighting portrayed i in a graphio story Bare Hanps—Partd. . By Hawthorne Daniel A gripping novel of man’s conquest of Nature RADIO Perrect “A” Current ror Your Rapio . By Alfred P. Lane You Neep a LicutninG ARRESTER . As told to Newton Burke THE HOME WORKSHOP . By Berton Elliot By Everett Eames By F. S. Browning How to Appty Art TRANSFERS . Butitpine A Corner CLOSET Hints on Usitne Taps anv Dies 20 21 23 Q4 14 40 61 63 73 74 78 4 Automobiles A Highway on the Roof Tops Tests Autoist’s Footwork Ignition Hints for Your Car . New Auto Motor . “Taxis” Old and New in the Gehan Theater Teaches Traffic Laws Odd Cycle-Auto Solves Gas Problem Rollers for Grade Crossings . Measure Auto Seat’s Bumps Novel Siphon Starter . Screen Your Car . Switch to Control Genmater Pedal Extension Easy to Build . A Table for the Auto Lunch Rope Luggage Carrier Aviation BSESSZSBRZ8RRB2SERSER LE 13 4 Fly Own Gliders in Novel Club . Trans-Ocean Airmen Crash in Test — Flight . . . ° 13 A Triple-Purpose War — 45 French Build “Ghost” Plane 47 Our First Ocean Air Liner? . 52 | Germans Have Flying Yacht 58 Exceptional People He’s America’s Orchid King! 39 | She Makes Bike Tires ‘ 46 Makes Table of 51,000 Parts 46 He “Clocks” the Big Races . 47 Lumberman Models Forest Crea- tures in Wood . ; 4 To Cross Ocean in Sailboat . 47 Loops the Loop in Auto . 49 Commands Arctic Ship 54 Uses Homemade Diving Helinet 55 He Makes Intricate Glass a ratus. . : « Mae Girl Daredevil Rivals Ma ‘ 56 Health and Hygiene What Your Nervous System Looks Like . ; 34 Does a Permanent Wen —— Yous Hair? . 84 How Do You Sleep? 35 Soap as a Germ-Killer 48 Deaths from Heart Disease . 49 Healing with Music 51 Salt ““Peps Up” Miners . 52 Don’t Listen with Your Eyes . & New Diabetes aed ne Insulin , 58 1927, Vol. 111, No. 1. Popular my Monthly is Bupéehed mes monthly Hy 50 Fourth ‘Avenue, New York, N. » by the Popular lishing Co., Entered as second-class’ ts r Dee. 28, 1918, at the Post Ome ‘at New York under the act of March 3, 1879; additional “entry as second-class matter at Chicago, Illinois. ps as second-class matter at the Post Office Department, Canada. Printed | . 8. A. Copyright, 1927, Ld the Popular Science Publishing Co., Ine. Bingle ‘copy, 25 cents. Yearly subscriptions to President and Treasurer; R. C. The use of Poouee United States, its possessions, and Canada, $2.50; foreign countries, $3. The contents of this magazine must not be reprinted without permission. In pre- senting in its editorial columns numerous stories of new products of ap; science, Popular Science Monthly does not underwrite the business m of the individuals or concerns producing them. Monthly articles for stock-selling schemes is never authorized. O. Wilson, Vice-President; A. L. Cole, Sseretary. Capen, uly, 1927 Rolls Auto An T Card Elect Send Movi Stom Lesse “ Mo’ a ————

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July, ira em BSSSBSBRSBRERBZSSZSELEES BSS sy ie 39 46 | a 2a- 47 4 49 55 a- le ur ces uly, 1927 POPULAR SCIENCE MONTHLY In This Single Issue We Publish More Than 250 Articles Depicting the Latest Achievements and Discoveries in the World of Science and Invention ——— Students Take Poison in Test How Does Noise Affect a Typist? Blood 1/2 of a Man’s Weight Laboratory Discoveries A New Electric Insulator Earth’s Bulgings Studied Ethylene as a Fruit Ripener Cathode Rays Dry Paint Oils. Engineers Study “Cold Light” . Whitewashes Defy Heat. . Test Machines in “‘ Padded C ell” Science Explains “‘ Bloody Rains” New Processes and Inventions It Sees through ae and Fog. New Microscope Pullmans Substitute Bedrooms for Berths . . ate ae a8 Electric Hole Saw. It Measures Furnace Heat Shows When Gas Is Poor Ingenious Combination Tool Three Lanterns in One! . Blocks Improve Acoustics. Paper from Old Dollar Bills . Cutting Steel with Iron . . Novel Device Compares Fingerprints New Ultra-Violet Lamp Detects FalseGems ._. Colored Lights Teach Piano. . Life Preserver Instantly Inflated New Fire Engine Uses Soap Suds Machine Tests Boxer’s Punch Tobacco Chemically Made “Eraser Key” Aids Typists . Vise Holds at Any Angle Odd Apparatus Produces Music” “New 54 54 57 34 34 34 35 35 45 49 49 12 35 39 4h 44 44 45 45 46 46 47 50 50 50 51 51 52 52 53 53 54 New Devices oo ihe Home A Furnace That Feeds Itself : Are You Planning to Buy an Oil Burner? .. ‘ New Fork Has Automatic Ejector Oversize “Tea Ball”? Cooks Rice Cup-Size Egg Beater. . Wide-Rim Pie Plate Can’t Spill Juice Candy Making Instrument Set... Versatile Traveling Iron . Metal Ring Saves Gas R New Cake Pan Has Window A Bath for Your Razor Blades . New Electric Mixer Saves Work. Electric Dishwasher Has fenatl Ca- pacity . Rolls Out Doughnuts - ‘ Automatic Safety Iron Stand 4 An Unusual Electric Fan for Your Table. Card Table Folds by Single Leg . Electric Range Runs Automatically Photography © Send Color Photos by Wire .,. Movies That “Live”. . Stomach Can Be Photographed . Lessens Movie Film Breakage “Movies” Preserve County Records 46 56 58 58 58 58 58 58 58 58 59 59 59 59 59 59 59 59 34 44 49 52 - 64 4 Radio Broadcasting from Balloons . New York’s Storm Detector World’s Biggest Vacuum Tube . “Mystery” Burgtar Alarm .. Has Radio Wave All to Himself How to Choose Condensers .. Be Sure to Have a Good Ground AB C’s of Radio . 7 35 45 46 47 55 60 60 60 Unusual Facts and Ideas Blowing Up a Mountain _. Six —-* Foot Leap by Balloon Jum : Whippet ‘eae a Race Horse World’s Largest Submarine . Firemen Test Water Pressure 500 Feet above Street. .. A Motor “What-Is-It” Traffic Cops of Other Lands" The Story of a Baseball .. Smoke War On in New York U. S. Sends Most Telegrams Cat Has Nerves Extracted Wealth Wasted in Lightning Houses of Rammed Earth Gold Plucked from Air . Is Quiet Necessary for Good Golf? . Ice Lowers 16-Ton Floor , Armor for Matador’s Horse Brushes from Chinese Pigs To Remove Unwanted Grass Salt Lake Changes into Fresh Staginga Deer Rodeo . . Ship Plastered with Oysters . Deposits by Chute in Burglar-Proof Bank . ; Carries His Own Breeze . Biggest Crane Afloat . “*Smell-Meter”’ to Fight Bugs ; Music Sets Off Powerful Explosive . Gyroscope for Giant Yacht . Find Mummy in Ohio Cave . Puncture Vine Spreads East Industry Now Uses Garnet ._. Recording Languages for Posterity . Falling Meteor Misses Cyclist Male Birds Hatch Eggs . . “Wheel of Seven Sad Sounds” . You Can’t Tell ‘Em Apart Six Musical Instruments in One! A Diamond Rush in Action . New Depths for Oil Wells Doll’s House in Match Box ._. Sixteen-Ton Bridge Holds Sixty-Ton House U.S. Phones England : a Sample Toot Building — —_— a Giant Task . 12 12 12 12 13 13 30 31 34 34 35 35 Ad 45 48 48 48 48 48 48 49 49 50 50 51 52 52 52 52 53 53 55 56 56 56 56 56 57 57 57 57: 57 64 Hints for the Mechanic Holder for Small Taps Made from Auto Valve. . A Small Shop Method for Tapping Nuts Quickly .. Inside Calipers Serve as Surface Gage in Emergency .. 3 An Angle-Iron Timber Hanger s Why a Tap Breaks . 104 104 104 104 105 4 ? Messntinn Angles with Extreme Accuracy . 105 What Causes Chatter Marks 105 How to Use a Diamond for Trueing Grinding Wheels ._. 105 Guard for Tapeline Case Made from Old Inner Tube. 105 Pocket First Aid Kit Goes in Small Razor Case. . 106 Expanding Chuck for Use in Fin- ished Holes. . 107 Substantial Horse for ‘Shop ‘Use Made of Iron Bars. ; . 107 Grinding Chucking Reamers_. 107 How to Straighten Hardened Parts 108 Using Micrometer to Measure Work with Concave Face . 108 Sheet Metal Holder Keeps Acid Bottle from Spilling . . . 108 Lengthening Short T-Bolts. . 108 Using Twin Angle Plates to Mount Lathe Work . : 109 Soft Jaws for Lathe Chuck. 109 Ideas for the Handy Man A Driveway for Your Garage . 15 Swinging Seat for Campers. 76 . “Tuckaway”’ Canvas Bed . 76 How to Make a Fire-by-Frietion Set . 76 Airplane Weather Vane. . 76 Rowboat Anchor for Fishermen 76 Hammering Out a Porch Lantern. 81 Replacing Jackknife Handles . . 82 Rubber Cement Mends Torn Hunt- ing Coat Invisibly. 82 Gimlet Bit Serves as Pipe-Cleaner. 82 Flaming Letters Light Camp . 84 Ground Glass Substitute P Easily Made . -\ oe Building a Sturdy Porch Swing 7 Tiny Decorative Galleon Has Wal- nut Shell Hull. . 87 How to Lock a Dial ‘Telephone Against Unauthorized Use . 87 Painted Glass Checkerboard 89 Oversize Glueing Clamps . . 89 A Square Peg in a Round Hole. 90 How to Solve the Popular Science Block Puzzle . ; 90 Tool Rack of Pipe Straps Sos 90 ~~" for Your Home Work- 91 Ruaes Candle Propels Fireworks Barge 93 High ote Fruit Press Made with Auto Jack and Rim . 93 Our Viking Ship Model. . 94 Aerial Top Made with Spools and Clothespin . . 96 Acetone in the Home Workshop 97 How to Make a Paneled Chest. . 98 Sturdy Toy Glider Folded from Let- ter Paper . .- —_ C-Clamp Made from Large Nut . 99 Neat Wooden Stand Holds Watch at Night. 100 How toGrind Smooth HoiesThrough Plate Glass . . 100 Window “Curtains” for Garage 101 Convenient Gate Latch . 101 How to Take Care of Paint Brushes. 102 # Preserving Large Corks. 103

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POPULAR SCIENCE MONTHLY August, WHAT IS NEW THIS MONTH Table of Contents for August LEADING ARTICLES Way We May Wart Twenty YEArRs For OcEAN Air LINES. . By Commander Richard E. Byrd, U.S. N. An expert’s view of future commercial sea flights Linpeercu’s GREAT PARTNER By Frank Parker Stockbridge Details of the first New York-to-Paris plane Tue First PLANE TO GeRMANY . . ._ By George Lee Dowd, Jr. Interesting Predictions by Aviation Authorities LIFEBOATS UNDER THE SEA . . . . By Alden P, Armagnac An inventor’s amazing plan to make submarines safe On THE’SEA IN A CABLE SHIP . By Edgar C. Wheeler Thrills in the lives of the “ocean linemen” A $10,000,000 “‘ AcciDENT’”’ By Kenneth Wilcox Payne The remarkable story of an unusual personality Eacu or Us Has Forty Staves . By Robert E. Martin Do you realize what you owe to electric power in your daily life? Hore ror Hay Fever Victims . By Norman C. McLoud How recent medical discoveries yielded a a new treatment StrRaNGE Ants Grow FLowers . . By Hyatt E. Gibson What a noted biclogist discovered in the jungle Even Worms Sotve Puzzizs By Prescott Lecky Watching “dumb animals” think New Turitiers Dery Graviry . ; By Elwell Crissey A revelation of the engineering skill that goes into amusement devices Deck Fans To AID Sea Fiyers . A Swiss engineer’s ingenious scheme for mid-ocean airplane landings Sam Loyp’s Puzz_e Pace Is Your Home Sare From Fire? , By John R/McM ie Some valuable hints on protecting your dwelling Wuen Your Moror S1zz1gs . , : By Martin Bunn Gus and Joe give timely advice on summer overheating Do You Know tHE Trout Asout O11 Burners?. How Your Euecrric Toaster Hewes Pay Pusuic Utmiry Drvi- DENDS . . By Wallace Ames FICTION Warriuine Wueers—Partl . By Edmund M. Littell * The birth of the automobile told in a fascinating new novel Bare Hanps—Conciusion . . By Hawthorne Daniel The swift climax of an absorbing tale of the North RADIO How to Hook Your PHONOGRAPH TO THE Rapio SET. By Alfred P. Lane ConTROLLING Rapio VoLUME By John Carr THE HOME WORKSHOP By Capt. E. A. McCann By D. M. Clayton By Charles Kugler A Sure-Mopet VANE LINDBERGH’s PLANE, Toy Size Cuttina THREADS ACCURATELY . 12 14 22 Q4 26 27 29 33 38 43 65 66 69 18 40 62 64 73 76 & Automobiles Briton Develops Cheap Fuel . . 4% Soft-Faced Hammer Saves Your Car 44 When You Drive Your Car Around a Corner . . Soom Movies Test Auto Drivers Mud No Terror to This Car! R. R. Gates Direct Traffic Twin Engines Prive Novel Bus . Amazing Car‘tTurns in Its Own Length . Odd Electric Car for Shopping Light Signals Auto Speed __.. — Auto Curtains from Flap- Ww histle Indicates Boiling New Battery Terminal Tool A Simple Spring Oiler An Emergency Hose Clamp Spiked Board Pulls You Out SSS222 2285 S888 Aviation New Motor Balloon .. — Gyroscope Stabilizer for Airplane . Ib Testing Helicopter Model . . . 7 Plane Hauls Glider in Aerial Train . 32 “Superpower” for Airplanes “Wing Flutter” Wrecks Planes Ingenious Device Tests Air Pilot’s Vision . ; Glider Soars Fourteen Wows New “Booster”’ for Airplanes S22 85 Health and Hygiene Eyeglasses and Efficiency New Disease from the West Blueberry Cure for Diabetes . . Aid for Deaf Has Tone Control . 47 Water Purified by Rays . 48 “Dust Mask” pe 4 Against ( Con- tagion S33 Hums You to Sleep . . . eee . ay | Laboratory Discoveries Oil Ships and Rainfall Sash Cords Tested at Bureau of Standards . ; Can Rays Produce Life? . That Mythical “Sea Level” Artificial Light Speeds Up Beets Test Cigarette Fire Danger . Sounds That Kill . sage Dark Rubber Lives Longer . The Speed Limit of Vision Tin Not Harmful. . ; Why Your Watch Slows Down. . Gas Appliances Made Safer . Laboratory Tests Models Tiny Whaling Ship for Movies ._ . $1 Model Building in Cork . . . Midget Locomotive That Runs. . & S BSStTa2esessesee & August, 1927, Vol.111, No.2. Popular Gptenee peogenty te published monthly at Fourth Avenue, New York, N. Y., by the Fopu r Science Publishing y as second-class matter Dec. 28, , at the Post Office at matter at Chicago, Illinois. Entered as second-class matter at the Post Office Department, Canada. Printed in U. 8. A. Copyright, 1927, by the Popular Science Pu biishing Co., Inc. Single copy, 25 cents. Yearly ‘subscriptions to United States, its possessions, and Canada, $2.50; foreign countries, $3. The contents of this magazine must not be reprinted without permission. In senting in its editorial columns numerous stories of new products of ap} science, Popular Science Monthly does not underwrite the business m of the individuals or concerns producing them. The use of Popular Science Monthly articles for stock-selling schemes is never authorised. oO. B. Capea, President and Treasurer; R. C. Wilson, Vice-President; A. retary. . Cole, See sgust, 192 Drill ¢ New I Warns “Touc Bur

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AUGUI I yet, 1927 H 44 44 44 46 48 48 48 50 51 53 68 68 68 68 68 68 ind wn ap- ne by S BSSV2uzezsessse & $1 $1 POPULAR SCIENCE MONTHLY a ———————— More Than 250 Striking Articles in This Single Issue Cover from Every Angle the Latest Developments in the World of Ynvention and Discovery — Carved Figures Depict Famous Battle vw Aut Small-Scale Railway in His Back Yard . ; Models for Flood Prevention Miniature Stage Tests Lights , Factory Ventilation Studied with Model ; Rubber for Ship’ s Crosstrees ae Ship Models Built from Our Blue- prints Constructs Miniature 31 31 31 37 55 56 79 . 108 New Devices for he Home Safety Guard for Your Iron Cord Detachable Edge — Knife Sharp ‘ Shears _ from Cob. Novel Glass Teapot Has Handy Ball . Pad Protects Your Ironing Board . New Asbestos Iron Stand Novel Washer Operates by Suction . “Heat Domes”” Cook with Gas Turned Off . ; Fish Clamp Makes Scaling Easy Adjustable Glove Drier . An Iron You Don’t Lift . New Grapefruit Tool. . Keeps Moths from Your Clothes “Holder for Holders” on Gas Range . Drying Rack Clamps on Radiator . Removes Vegetable Seeds and Skins New Processes and Inventions Life-Saving Suits for Harbor Firemen France Tries Iron Roads _. New Device Rectifies Current Odd Oil-Burning Locomotive Houses Washed by Machine Ten-Pound Electric Handsaw Magnet Saves Worker’s Eyes Electricity Hastens Crops . . Flame Burns Under Water in New Boiler. ‘ Portable Reading Lamp Holder Map Puzzle Teaches Geography. Wooden R. R. Ties Passing . “Ultrawhistle” Gives Silent Sum- mons . Auto’s Exhaust Heats Coffee Pot Lunch Kit and Table in One “Ear Lorgnette” for Theater —— Fisherman Reels Them n ‘ Hat of a Dozen Shapes a Clock Controls Electric Lights . Saw Guide Replaces Miter Box . Live-Saving Suit Resembles Diver's Costume . . Mechanical Smoker Breaks In Pipes High-Speed Marker Lays Traffic Lines. ; Overheated Engine Stops ‘Ttself . Signal Stops This Elevator . A New Way to Open Letters . Drill Carries Its Own Motor New Paint Stops Oil Leaks . Warns of Dangerous Fumes. . “Touchy” Electric Cable Traps the Burglar . . . E ‘ 58 16 44 44 45 45 45 46 46 46 47 47 47 47 49 49 50 50 50 50 50 51 51 51 52 52 53 54 54 55 55 4 * Tests a Tipplers’ Breath . Strange New Liquid Makes Wood Fireproof. Space-Saving Gas Mains Shaped like Planks . . ‘ Liquefied Gas for Fuel Manless Tractor Plows without Steering . eis $2,000,000 Offered for His Picture Invention , Cop Invents Anti-Burglar Camera . New Camera Faster Than Lightning Feeds Movie Film at High Speed . Portable Arc Lamp Aids Amateur Movie-Makers . ; Radio New Radio Beacon . “Radio Watchman” Guards Ohio Reservoir . — Hunting Treasure by Wireless . Radio Lights to Guide Airmen ._. Weather Maps by Radio for Los Angeles . . . Hides Antenna in Ship’ s Hull “Radio Roof” 100 Miles Up New Ideas for Chargers . Static Still Uneonquered . Keep Tube Prongs Clean Heat Spoils Dry Cells C-Voltage for Power Tubes . A B C’s of Radio . : Ships Destroyers Ready for Scrap ane , Most Powerful Fireboat . . ; “Old Ironsides’”’ Comes Back Destroyer Her Own Dry Dock Like a Fly in a Sugar Bowl. . . “Black Fleet” Fails to “Capture” New England ; ese Repairing a Superdreadnaught, ‘ Britain’s New “‘ Mystery Ship” Monster Warship Aground . . Modern Hospital Sails with Fleet Largest Oil anaes — to Have No Funnels . 56 ¥ Aerial Car Paints High Electric 56 57 57 60 17 37 48 50 30 30 30 30 30 30 35 55 Unusual Facts ail bites Moving a 350-Foot Front Man Was Neveran Ape. . Telephones from Ocean Bed . Treasure from the Dead Sea Metered Fuel for Homes . Re-Create Indian Salt Mine Giant Testing Machine . Rebuilding a Whale . . Faraday’s Coil Brought to America . Traffic Tower ina Hotel. . . Counting Cash by Electricity Artificial Heat for the Ocean. Largest Dredge for New York’s Bridge . ; How Apes Might Talk Building Stone Waterproofed Speeding Up the Chariot Race . More Power from Less Coal . Coaling a Locomotive Minutes . . in Four a7 35 36 36 36 36 36 37 a b Cable. 53 Mammoth Tool Bores 13-Foot Cyl inders . , 53 To Hush Riveters | 54 “Perpetual Motion’ *_Almost 55 Twins’ Minds Run Alike 55 Building Mammoth Generator . 55 Measuring Niagara’s Power . 55 X-Rays Ferret Out Rum. 56 Hottest Spots on Earth . 56 Seventy Million Phone Calls a Day 56 A Deep-Sea “Butterfly Net” 56 Valuable New Mineral Found in Vast Deposit . 57 Canal Runs through ’ Five-Mile Tunnel . , 57 Plaster Statues Made Bronze. - Hints for the Mechanic New Machines Aid Mechanics . . 102 Diamond Holder for Surface Grinder 103 Installing Leather Packing . . 103 Piece of String Solves a Tapping Problem. . 103 Non-Removable Rivets ‘for Small Plates. . 104 Working Cast Iron onthe Lathe. . 105 Oiled Reamer Bores Smaller . 105 Compound for Chasing Threads . 105 Oiling Hints 105 Soap Serves as Cutting Compound, Cools Bearings . 105 Pliers Adapted for Knurling “a Milling Odd-Width Narrow Slots . 105 Holding Short Pins Vertically . 107 Ideas for the Handy Man Kitchen Table Serves As Bench 75 How to Mix White Lead Paint . 75 Lindbergh’s Plane, Toy Size 76 Timesaving Mail Box Has Hinged Bottom . . obs Oe A Plug That Fits Three Holes . . Constructing an Egyptian Type Stool 78 A Hall Mail Rack Easy to Build 78 How to Make a Teakwood Tea Tray Table. . 7 Toy Glider Made with Feathers 79 Archers Can Make Own Targets 82 A Real Home for Your Dog. . 84 Adapting a Carpenter’s Level for Testing Inclines. ‘ 84 Hiding Defects in Woodwork 84 Varnishing Glass . . 85 How to Do Wrought Ironwork . . 86 Blueprints for Your Home Work- SaaS 87 Building a Sand-Box Play Shelter 88 Cement for Filling Cracks ; 88 Patching a Shingled Roof 89 Stopping a Water Leak . 89 Liquid Metal Polish .. 89 Solving Your House-Painting Prob- lems. . ; 90 Rebuilding a Transmission . 92 Bench Vise Helps Clamp Glued- Up Work. 93 To Bore a Flat Steel Spring . ; 93 How to Make a Paneled Chest . 94 How to Fix a Noisy Electric Motor . 98 Pine Cone and Feathers Make tend Peacock . 98

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POPULAR SCIENCE MONTHLY WHAT IS NEW THIS MONTH Table of Contents for September LEADING ARTICLES America TAKES TO THE AIR. By Frank Parker Stockbridge Strides we are making toward “sky traffic” Our Sun Is Surinxine! . . « By Arthur A. Stuart Latest discoveries of our solar neighbor’: s secrets Coutp Air Invapers Destroy Us? . . . By Caleb Johnson A startling picture of a future war terror How Anmats Maxe Love. ... . . By Elwell Crissey Strange mating ways of odd creatures Buasts Toat SavepaCity . . . ._ . By Orville H. Kneen Wonderful new uses of dynamite Next We’Lt SEE To Paris By George Lee Dowd, Jr. Plans of a “television” pioneer to span the Atlantic Way We Mos Herogs . . ByA.A. Brill A psychologist’s remarkable disclosure of the reason we hail “ supermen” Piows a THousanp AcrEsA Day. . . By Wheeler McMillen Mechanical wonders of an up-to-date farm He Traprep THREE BanpiTs WITH A Microscope! By Edwin Ketchum How chemistry aided a thrilling man hunt Wauat’s AT THE Top oF THE Sky? . . . By Alden P. Armagnac Sensational air dashes into the greatest unexplored region of all Wuen Neptune Scowlis. . . .« « By Jack O'Donnell Queer misadventures of ships at sea $10,000,000 War on Worms. . . A glimpse of a nation-wide struggle with the devastating corn borer AIRPLANES 2,000 Years Op! . . . By H.C. North Remarkable “modern” devices used by ancient priests To Evrore By Rocket . . » 4 An amazing airship that could cross the ocean in in ninety minutes Wauat Everyone Asks about FiyiInc. . « « Answers to familiar but little-understood aviation queries Sam Loyn’s Puzzie Pace A House with 30 SERVANTS. Modernizing your home with electricity Some Five Points or Vatve Grinpinc . . By Martin Bunn Gus and Joe discuss an “‘easy”’ job Dw You Ever See Tone Qua.ity? . # Way Pusuic Utiuitres Arse a Goop INVESTMENT By Wallace Ames FICTION ; ScHEDULE Or— — Leo F. Creagan A thrilling story ‘of an express train’s race against time Warruinc WHEets—Part2 . . By Edmund M. Littell An unusual novel of the automobile’s invention RADIO TRICKS OF THE Rapio Quacks . By Alexander E. Senauke THE HOME WORKSHOP By John R. McMahon New Ways To Paint Furniture . . . . . By Berton Elliot How to Burp a B-Exmuator . . . . By Alfred P. Lane System in Surrace Grinpinc . . By Hector J. Chamberland 17 18 20 21 23 24 27 29 30 35 40 41 43 62 65 66 69 &m 14 32 63 73 74 78 Automobiles Illuminating Gas for Your Car? Wheel Operates Car Lights . A Motorist’s Rocking Chair Sight-Seeing Bus Has Balcony Baggage Car for Your Auto . Your Car’s Brakes : Motors Race to Garage Roof Electric Brakes for Autos “Sidecarette” Carries Three Headlight Utility. .°. Old Tube Holds Luggage A Wheel Puller... Protection against Thieves . . Wire Loop Holds Screw . . . , Aviation Flying Safety Increases Super-Beacop for Chicago Radio Beacons Guide Airmen “Balloon Bicycle” Invented A “Flying Doughnut”. Plans Plane to Fly Forward, Back- ward, Upor Down .. Flyer Takes His Car Along . ‘ Exceptional People Takes Notes beneath the Sea . . 18 Steel Magnate Plows Own Farm . 1 Smallest Grandfather in the World? 18 Making Gigantic Statue of Christ . 1§ Prepares Cheap “ Platinum” Mimics Wood with Concrete Gets Medal for Purest Insulin Man Races Horse. . **Hops Off” from Surf Board Makes Clock Case of 5000 Pieces Build Their Own Speed Boat He Made Himself an Automobile Health arid Hygiene New War on Heart Disease . Perspiration Causes Weight Loss Lights Show Inside of Eye Heart Murmurs ‘‘Tuned-In” Refutes Attack on Oatmeal . Wakes Up Sleeping Muscles Manikin Teaches Posture SAerisessesS Ss SAIwSeLS Laboratory Discoveries — Bared by Strange Detective ays. . Test Plants with Ultra-Violet Light. Engineers Check Earth’s Slip Every Atom a Flashlight Approaching Synthetic Life . Fingerprint Records on Skin Poison Ivy Antidote Found . “Armor” of Germ Analyzed What the Moon Is Made Of Squirrel’s Memory Tested Charts Predict Track Record . Bricks Are Now Tested final Their Ring . ; SSF Ftesesesses Ss September, 1927, Vol. 111, No.3. Popular NEVO aA OO month- United States, its possessions, and Canada, $2.50; foreign countries, $3. Tb at 250 Fourth “Avenue, ‘New York, N.Y., by the Science Publishing contents of this magazine must not be reprinted without permission. Inf in its editorial columns numerous stories of new products of app , Inc. Entered as second-class matter Dec. 28, Suita at the Post Office at senting New York under the act of March 3, 1879; additional entry as second-class science, Popular Science Monthly does not underwrite the business meti matter at Chicago, Illinois. Entered as second-class matter at oe Post Office of the individuals or concerns poems them. The use of Popular Sc Department, Canada. Printed in U. 8. ex Copyright, 1927, the Popular Monthly articles for “aor B. Cap Science Publishing Co., Inc. Single copy, 25 cents. Yearly ‘ad scriptions to President and Treasurer; R. ng schemes is never authorized. O. . Wilson, Vice-President; A. L. Cole, Secretati BSBSSB822E2R22R5R R23 SSeS

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Septembg September, 1927 'H r? 3ack- Ss ble 1g orld? 18 ist . wy SAaersssssS SAaIwsweEES eries ective ight. 31 8 39 39 . & 4 4 43 . 4 5 él Their 2 SSS222R2S2RRR8FE2 SSEAnS — POPULAR SCIENCE MONTHLY A New X-Ray Discovery Germs Give Light Uranium Aids Growing Crops 57 Only Four Basic Odors 59 Models Models Show Earth’s ee 38 A Skyscraper of Glass 50 Builds Old Ironsides . 54 Lawyer’s Hobby Repairing Old Ship Models . 54 A School for Ship Modeling . 54 Ship Replicas Their Business 54 Makes “Spanish Galleon” . 54 Model Yacht Tests Odd Design 54 Electric Motor Drives Baby Plane . 55 Making Blocks for Ship Models . 105 Ship Models Built from Our Blue- wi prints New Devices io the Home Gravity Operates This Salt-Shaker . 60 Unusual Coffee Pot Has Strainer in Lid . 60 Automatic Heat Control for Iron 60 Combination Salt and Pepper Shaker 60 Makes Your Candlesticks Electric . 60 New Tongs Save Your Hands . 60 Double Fork Picks Up Hot Things 60 Odd Ladle Drains Vegetables . . 61 A Percolator You Can Take Apart. 61 Peels Oranges with Two Motions . 61 Space-Saving Refrigerator Dishes . 61 Sanitary Waste Receptacle . . . 61 A Picnic Container for Seasoning . 61 One-Hand Serving Utensils ._. 61 Prongs Keep Your Pictures Straight 61 Toasts Four Slices at Once .. 61 New Processes and Inventions Latest Armored Car Charged with Electricity . . ; 13 Matching Colors by Machine 38 Boards from Lumber Chips . 39 Machine Fights Forest Fires 44 Builds Diving Motor Boat 46 Vibrating Bed Woos Sleep 47 Mask Saves Pugilist’s Face . 47 Clock Like Speedometer . 48 Device Indicates North Star. 48 A Razor-Blade Lawnmower . 48 Folds 5000 Letters an Hour . 48 Fertilizer Applied by Hose 49 Canoe Built of Paper 49 Saves Gold for Dentists ._. . 49 Scarlet Ray Is New Traffic Signal . 49 “Seasick Chair” Tests Saiiors 49 Magnifier in Pencil Style . . . Si Turbine Locomotive Tested . 52 Telephone Meter Sells by We rd 56 Lifeboat Inflated Like Tire . 56 Self-Service Hat Checker 57 Amazing Engine Tested . 57 Tent Train Saves Pavement 58 Radio Electric Device Makes Sy nthetic Music . . Baa Engineer and Brakeman Talk by Radio. : Wave of Hand Starts Steel Mill Lights Controlled by Radio . Turns Your Phone into a Radio Set Big Gain in Radio Precision Neat Wiring Made Easier Binding Posts That Hold Locating the B-Eliminator Shield the Detector Tube A B C’s of Radio . ‘ Unusual Facts and Ideas Baseball at Night under Floodlights Giant Locomotive and Its “Pup” Huge Switchboard for Summer White House —— World’s Highest Dam Your Capacity to Learn . Tiny Plants Tunnel in Stone Can Animals Run Machines? A Welding Shop on Wheels . Thousands of Tons of Color Personalities Made Over Bees Sip Poison . ; Largest Dock in the World - Earthquake “Made to Order” Expedition to “‘Lost World” Hop Growers Work on Stilts ; How Much Do You Know of the World You LiveIn? . . Dike to Enlarge Holland Bulkiest Freight Parcel Aviator Chases Rainbow Horse’s Mummy in Coffin. Biggest Family, 44 Children? Seeds Forecast Tree Sizes Dropper Feeds Tiny Birds. Garden Is Floral U. S. Map Unpacking a 23-Foot Python Huge Book Taller Than a Man Rat-Proof Ships End Plague Start of Balloon Race. . , Fearless Men Vanishing from the Earth? . : Almost Beats the Camera Prehistoric Monster Lives 2,000,000-Year-Old Pine Cone Schoolboys Build a House Live on a Vast Ice Cake . Pipe Sweetened by Steam Fights Skyscraper Fires .. What Turns Animals White? Mighty Natural — Could seal ply Cities ; Birds’ Nest in Mop . Organ Nearly Wrecks Itself | Insane Sleep in Sawdust Bed Zoo Sells Elephant Hides Roman “Cannon Ball” Found . Grasshopper in a Glacier For the Home Builder Are You Planning to Buy an Oil Sash Weights Force Stubborn Win- Win oe ee net Fe, 3 Shelves for a Child’s Room . . Invisible Springs Keep Windows from Ratiling r Adding a Room to Your House . . How to Insert Flashing under Old I ee dF. 104 Combination Awning and Shutter foe Bumesiow ... ... 3... 110 Puttying Sash Lights ...... 112 Hints for the Mechanic Draft Regulator Protects Boiler . . 116 Milling Cutter Locates Index Plate weet a te eet dk 116 Simple Shop-Made Chuck for Hole 13 ccc OS hae 117 13 | Old Auto Motor Used for Hoist . 7 Illuminated Table for Tracing Blue- 13 OE 6 6:2 tome eie wee F 118 37 | Pencil Holder for Dividers . 118 38 | Angle Iron Rack Holds Many Tools 119 38 | Indexing Welded Gear Teeth . . . 119 38 | How to Obtain a Light Driving Fit 44 UN cielid cals Mica leben 120 44 | Clamp for Holding Small Round 45 Finished Plates ........ 120 45 | Triple Center Punch Lays Out Dies . 121 46 Welding Torch Bushes Holes in Foun- 46 gt ara aS ee 121 46 | Piston Ring Keeps Line Shafting 46 Ce sw 0's 6 0 'Sers Se 121 46 47 f Ideas for the Handy Man 47 | Improvises Rudder Post from Car 50 a. area r * 55 50 | My Motorized Shop Cost $20... 76 50 | Unique Noah’s Ark Toy Floats or 50 a rere 80 51 | A Handmade Canoe Paddle. . . . 80 51 | Simply Built Reading Tables . . . 81 51 What You Can Make of Stone. . . 82 52 | Howto Take Up Rod Bearings . . 84 ‘ | Hints on Using Hand Screws for 52 WOMEME 5 6 6k gs ie 4 84 53 | A Cube for You to Whittle . 88 53 | Toy Auto Built for Speed .. 90 53 | A Cabinet for Your Curios . . 92 55 |° An Aquarium at Low Cost 96 56 | How to Make Tables, Chairs and 56 Accessories for the Camp é 98 57 | Simple Straw Instrument Measures 58 TN ik 6 ta oe bo a ae 100 Net Handle Aids in Shooting a Bow . 101 58 | Howto Make a Sewing Cabinet with 58 Lyre-Shaped Legs ....... 102 . 58 | A Dressing Table for Baby . . 104 . 137 | “Framing” Pictures with Fiber . 187 a, ree Teer 106 . 143 | What Do You Want to Make? . . . 107 . 143 | Making Garden Hose Washers. . . 116 Replacing a Broken Glass Knob 110 Iron Holder and Stand. ..... 111 Tightening Loose Casters... . . 111 Linoleum Drainboards ..... . 112 New Waysto Paint ....... 113 59 | Combed Stencil Effects for the Ame- telir DOCONEEEE. 2. sss ss 113 82 | Ammonia in the Home Workshop . 114 86 | How to Prolong the Life of a Wooden NT igs 4 6% 4 115 86 @ An Easy-to-Fit Cork... ..... 115 More Than 250 Striking Articles in This Single Issue Cover from Every Angle the Latest Developments in the World of Invention and Discovery

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POPULAR SCIENCE MONTHLY WHAT IS NEW THIS MONTH Table of Contents for October LEADING ARTICLES ComMMANDER Byrp Te.ts How to Get INTO AVIATION , Famous flyer answers a young man’s questions about the flying game Tue Conriict BETWEEN SCIENCE AND RELIGION ; Introduction by Bruce Barton A discussion of evolution and theology by leaders in public life Arrman Piunces Seven Mixes 1n Buazine PLane ... By L. G. Pope The miraculous escape of an altitude flyer, seeking a record One Minuionts or AN Inch PootocrapHeD!. . . es New steel-making secrets from high-powered microscopes ~ Waar Linpsercu Founp In His Mart Baa. Surprising facts about the greatest postal deluge in history Wuat Basies Born Topay May SEE . Scientists’ prophetic vision of the future Lapysucs Brep To Say Pests. Queer soldiers in an amazing battle ‘TREASURES FROM THE SKY . Astonishing new facts about meteorites Mopernw Maatc i Licut Marvelous creations of engineers who study illumination THe Mopern “Iceman” ARRIVES . An authoritative discussion of iceless refrigerators Tuey’RE CREATING A New Wortpd . How chemistry’s triumphs are remaking your daily life Cuaart TeLtts WHEN TO Marry. By Hornell Hart A fascinating scientific way to foretell your chance of happiness Next—Tre Crasu-Proor PLANE. . Inventors’ ideas that may end danger in fight Sam Loyn’s Puzziz Pace ‘ Is Your House Bureiar-Proor? . Simple ways to guard your home against intruders Don’t Br A Bacx-Seat Driver! . By Martin Bunn Gus shows the dangers of too much advice by passengers Tue ANsSwErs TO YOUR QUESTIONS ON Rapio OPERATION Tue Financia, ADVENTURES OF JERRY QuirK . By Wallace Ames FICTION Taus Up!. . . By Cy Caldwell Tense moments of a test pilot, as told by one of them Warriinc WHEeets—Part THREE . . By Edmund M. Littell « The Story of the Automobile Age in a fascinating novel RADIO Rapio Questions Everrpopy Asks ..... +... -« Common queries answered by an expert TRENDs OF THE YEAR IN Rapio. . By John Carr A survey of what the market offers broadcast fans Mopern “B” Suppty ror Oxp Sets By Alfred P. Lane How to adapt the “De Luxe” or factory-built eliminator THE HOME WORKSHOP Patcuinc DamMaGep FurniturRD . . By Chelsea Fraser A Fiytne Mopet or LinpBEerGnH’s PLANE. By J. Danner Bunch and Avison F. Koch Bertrer Heatine at Lower Cost . By Charles B. Carlon . By Fitzhugh Green By Myron M. Stearns . By Arthur A. Stuart By Neil M. Clark By Robert E. Martin By Prof. Collins P. Bliss .By Louis E. Van Norman By Join R. McMahon 12 14 15 18 21 23 27 30 33 35 39 43 66 67 69 62 63 78 75 76 77 “Puncture-Proofing” by Uncle Sam... Know Your Car. . . Simple Holder for Hats Chamberlin’s Flight f Leviathan . .... Motor Car”’ Asia Smallest Monoplane? a re New Flying Battleship Porous Parachute Safer Beacons Pierce 15-Mile Air Tour Cheaper Than Reveals How Birds Fly Sky Ambulance Travels Exceptional Builds Luxurious Doll’s Modern Pace Takes Its Automobiles He Manufactures Half-Size Autos . Tested Auto Jack Always in Place ... . Engine Pumps Air Mattress ‘ Windshield Wiper Holder. . . . . Ten Dollars foran Idea. . . . . . Emergency Valve Grinder. . . . . Chains Last Twice as Long . . . . Aviation tom the Huge British Transport Plane. . . Ten-Passenger Monoplane “Safe as Luxurious Air Service in Europe and Extra Wing Gives Stability . . . . Tiny English Flying Boat . . Huge Beacons on Wheels for Air De- Balloon Sets Distance Record . . . Balloon Can Fly for Weeks . . . . What Speed Can Man Endure? . . _ Midget 250-Pound Monoplane. . . Radio Lights Guide Aviator A Plane with Revolving Wings Glider Moves Wings Like a Bird Finnish Plane Has Ice Runners . . Rail Fare . Planes Used in 156 Ways. .... New American Air Lines on Plane “Flying Doughnut” Plane Crashes . People Shoots Himself from a Cannon ‘ Young Inventor Wins Big Reward . Castle. . . Woman Becomes Oil Expert. . . . The Youngest Deep-Sea Diver. Amateur Astronomer Builds Camera Monk Carves Passion Play . Girl Druggist at Twenty-One . re Builds Huge Camera on Auto. . . Sculptures with Dental Tools . . . Airport Run bya Woman .... Clergyman Builds Own Church . . A Real “One-Man Band”... . . Health and Hygiene =e Poor Blood Causes Old Age. . . . g Hardy Germs Survive Boiling . . . SSSSS8S3S8S8S8 S43559 Ree SaARGKRRASSSS5S October, 1927, Vol. 111, No. 4. Popular Science 4 / is pees month- at 250 Fourth Avenue, N New York, N.Y., by . & opular Science Publishing ntered as second-class matter Dec. 28 , 1918, at the Post Office at New ork under the act ‘ot March 3, 1879; addit 4 entry as second-class Beet ae ea anced eRe Caaattt at Op tne Popes men e PO Science Publishing Co., Ine. Single copy, 25 cents. enslyy oubeatlptione nited States, its possessions, and Canada, $2 pon A of nis magazine must not be rep sent its editorial columns numerous stories ce, Popular Science Monthly does - underwrite the business m or concerns hem. The use of Popular Science oatiing schemes is never authorized. O. B. Capel, resident; A. L. Cole, scien of the individuals Monthly articles for stock: President and Treasurer; R. C. Wilson, Vice-P: roducing t Any without permission. In of new pi roducts of ap foreign countries, $3. The re- — — ————

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oS e as and De- S2I2222ze8E2 # “7 : es le rd sera ne 36 46 41 $3. The BoP: ec! an —— SSASS4SSSSSSSRSSS8S8 SSss $ SS SRARGKRRARSSSERS POPULAR SCIENCE MONTHLY English Foot Census to Standardize i 47 Sizes “ec ” Nerves at Work Get “Het Up” . . 53 Laboratory Discoveries Fastest Top inthe World. ... . 36 Tests “Fire Thermometer” . . . . 36 Predicts Race of Supermen . . . . 37 Coat of Paint Warms House. . . . 44 New Tones from the Flute .... 45 Platinum Analyzes Breath . . . . 45 Atoms Smashed at Last, Scientists ee a es oes 53 New Devices for the Home Ingenious Rubber Cap for Bottles. . 60 Dishing Ladle Serves as Mold. . . 60 Triple Kettle Conserves Fuel yk String Beans Cut by Machine. . . 60 A Funnel for Small Bottles .. . . 60 New Lightweight Vacuum Cleaner. 60 A Combination Can Opener. . . . 60 Knives Made of Stainless Glass . . 61 A Food Grinder for Every Need. . 61 A Lock that Can’t Be Picked . . . 61 Miniature Electric Range. . . . . 61 Handy Grapefruit Corer... . . 61 Adding a Handle to Sauce Bottle . 61 Simple Device Shells the Peas. . . 61 Gas Range Has Broiler Drawer . . 61 An Improved Cheese Knife... . 61 New Processes and Inventions New Amphibious War Tank. . . . 16 Remarkable Car Fights Forest Fires 17 Air Propellers Guide Rudderless Boat 17 Electrical Machine Audits Sales . . 17 Designs Trans-Atlantic Speedboat . 17 Inventions Speed Up Modern Foot- ball ere ae ee eee 32 Dryer Makes Hay While It Rains! . 32 What the World Wants of Inventors 38 A Sight-Seeing Railroad Car. . . . 44 Steel Belt Mends Tools. ..... 44 Whirling Shafts Move Sugar. .. . 44 Silk Made from Cornstalks Prom- ises Farmer Profits. ...... 45 “Centipede” Aids Tunneling . . . 45 Asphalt “Cures” Concrete . . . . 45 Electric Timer at Regatta. . . . 46 ee Used to Measure Crops 47 ests a Pianist’s Muscles Grass Clippers Save Your Hands. . 48 A Hair-Curling Automat . ... . 48 Tool Removes Broken Screws . . . 48 Hay Cut and Stored by Compressed MO, we 48 Balloon Life-Preserver .. |... 48 Toasts Bread at Sixty Slices a | ae See Pee 48 Novel Hoist Piles Lumber in Mill ks aw a ee, ke 48 Sensitive Device Detects Voice’s sarees gies 48 Children Pedal Own Merry-Go- se ee kere Ce 18 49 Odd Magnifying Glass Self-Focusing 49 Skinless Hot Dogs Perfected. . . . 49 Non-Spillable Drinking Cup for MS Sw tk 49 ] Combination Fountain Pen and “Headlights” for Pedestrians . . . 49 A Many-Purpose Microscope-Tele- Hot Air Polishes Metal Big Balloons from Tire Tubes . . . “Electric Eye” Gives Burglar Alarm 51 A Garden on Shelves... .... 51 “Rockingbed” Duplicates Train ee eae ek 54 He Swims by Machinery ... . . 58 A Distillery for Steel. . . . . . . 58 Natural Wonders Bottom of Sea Yields Oil . . . . . 36 Looking intoa Voleano. .... . 37 Braving Arctic for Science. . . . . 37 A Mystery of the Heavens .... 44 Study Your Rainbows; Data May pe eee eee 46 Filming Earthquakes. ...... 47 Trailing Will-o’-the-Wisp .... . 51 Hailstones Big as Baseballs Puncture | |” a rr 52 Raindrops’ Measures Taken. . . . 53 Radio Radio Hastens Barley Growth. . . 46 Helps Ships Defy Fog ...... 47 Power on Short Wave ...... 50 Radio Set in Cone Speaker .. . . 50 New Radio Time Signals Keep World RG thas oa 6 eo ee 52 Motor Run by Radio ...... 54 AMCecd meee... issue 65 Advantages of Cabled Leads ... 65 How to Use Condensers. . .... 65 Unusual Facts and Ideas The “Fighting Face” of a Battle- . Footprints Milleniums Old .... 36 Ants Practice Agriculture. . .. . 36 Snakes’ Hospital Has Beds and Diet of Imported Bugs ....... 44 Giving Steam “Elbow Room” .. 45 “Pillows” Made of Milk .... . 46 Gas Warfare Called Humane ... 46 Everglades to Be Reclaimed . 46 Hands Shape Hammer Handle. . . 46 Smallest Book inthe World. . . . 47 Vampires Let Victims Sleep. . . . 47 **White Terror” of Sea Ended 50 Snakes Outwitted ........ 50 Does Earth Turn on Core? .... 51 Root Grows Like Duck’s Head . . 52 Twenty-Five Acres of Glass. . . . 52 Shipyard Built Far from Sea... 52 Lamp Made of Gun Shell. . . . . 53 Toy Soldier Many Ages Old ... 53 Eagles Trained to Hunt. .... . 53 All Bride’s Attire Synthetic . . . . 53 High Pressure to Crush Egg ... 58 Railway School Underground . . . 59 How Much Do You Know of the World You Live In? ...... 59 4 For the Home Owner Paper Hanging Made Easy .... 80 Clothes Hamper of Woven Paper . 100 Novelty Finishes for Woodwork . . 100 Removing Paint from Woodwork . 112 Staining New Wood to Match Old . 112 Refinishing Golden Oak Chest. . . 114 Gray Stain Effect on Oak... . . 116 How to Sandpaper Moldings . 118 Removing Furniture Blemishes 26 How to Free Nickel from Rust . 118 How to Prevent Brown Spots in’ PoumteneCeaer . ww ws 137 Imitation Antique Oak... .... 145 How Much Wall Paper to Order. . 144 Hints for Mechanics When’s a Right Angle Right? . . . 82 Repairing a Split Saw Handle. . . 92 Dressing a Worn Emery Wheel 98 Why Some Saws Have “Nibs” . . 106 Center Punch for Young Machinists meee | So LOR AUG o's 12 Gages for Milling Cutters. ... . 122 ea a eee 126 Grinding Threads on a Lathe . . . 127 Square Ladle for Pouring Metal . . 128 Old Tap and Valve Handle Used as Chuck wee 2 ee 128 Heavy Trammel Points for Large ee ee ere errr 5 oe 129 How to Protect Reamers .... . 129 ~ Testing Dies for Hardness ... . 131 Self-Centering Punch for Use with , s_si(‘édgsh eS APPR ams Con 132 Special Lathe Dog. ....... 138 Speedy Tool for Boring Large Holes PR RE sixes, 53:0) Gerster ead teal 134 Special Tools for Auto Repairs . . 141 Replacing Electric Motor Bushings 146 Old Wrench Serves as Anvil . 146 Ideas for the Handy Man Finishing Your Ship Model . . . . 84 How to Build a Boudoir Cabinet 86 Barbless Arrowheads for Hunting . 94 A Simple Outdoor “Gym” .... 96 Wear-Proof Thwart Fastening. . . 96 Lattice Decorates Flower Box. . . 98 Clamp for Gluing Furniture. . . . 98 Bench Plate for Riveting . . ... 98 Blueprints for Your Workshop 102 Tape Aids in Taking Portraits 104 An Automatic Camera Timer . . . 104 Miniature Clocks Easy to Build . . 106 Toy Whistle Made from Spool 108 How to Lengthen a Stepladder . 108 Home Workshop Chemistry. . . . 110 Bed Rail Joints for Tables . 120 Building a Circular Tower . . . . 120 Novel Test for Electric Cord . . . 120 Bench Legs from Angle Irons . . . 126 How to Make Anchor Bolts. . . . 127 Ship Models from Our Blueprints . 130 Bit of Thread Detects Gas Leak . . 134 Uses for Old Umbrellas. ..... 137 Novel Way to Decorate China . . 138 Sewing Cabinet of Rare Charm . . 142 » Installing Ship Model Lights ka Hundreds of Striking Articles in This Single Issue Cover from Every Angle the Latest Developments ‘in the World of Invention and Discovery ee ————

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POPULAR SCIENCE MONTHLY Novemb T E s S Table of Contents for November ; M Si M LEADING ARTICLES T Astronomy N I’m Gorne To Raise My Boy to BEA PLumBER. . 9 If As a —— Blow Up We'd 7 By Kenneth Wilcox Pay yne Bi ca Te di By te Too Bi Rie eae 58 T Does a college education pay? Suey ett Oe die oe 9 94 ; N Is Fiyine REAuiYy Sare? .. By George Lee Dowd, Jr. 12 ea! ae The truth about the dangers of aviation Automobiles Frx Limits or THE UNIVERSE . By Edgar C. Wheeler 15 Making the Grade... ..... 31 SI Astronomy’s new measurements of the world i mae 3 oe sah — soe a H yasoline” Made from Coal . . . An UnrockaBie Sup. h h ‘ 17 Solid Tires May Blow Out . . T Keeping a yacht steady with a mig ty gyroscope Dangling Straps Warn Motorists of | Wuo Dip THe SHootina? . By Calvin H. Goddard 21 ss ts ss ss oom 49 | N How a bullet’s “fingerprints” yield telltale clues A30-Inch Car ......... 1 ‘ Lasoratory May Propuce Lire . . By Sir Oliver Lodge 23 Express Lanes for Motoring. . . . & § A startling prediction by a noted scientist Know YourCar......... 52 Ne Autos Play Leapfrog. ...... 59 A Turrp DEGREE FOR AUTOMOBILES . . By Fay Leone Faurote 24 hinGueastine: ..... 70 P Cars tested in amazing new ways Dash Indicator for Lights .... 1% ’ You’ve Gort a Patent, But— . By Bruce Donald 26 Ingenious Auto Striper. . . . . . 70 Ne Mistakes some inventors make i in safeguarding their ideas Extra Curtain Adds Comfort ... 70 | Can THE Bees TALK? .. By Myron M. Stearns 27 a me 4 a ee oe i. Sp Marvels of communication that rival our own we nage verte he toaray 70 : Solving Auto Engine Secrets. . . . 144 Te New Mernops or Trarric CONTROL ._ By Earl Chapin May 29 What to Look for When Your Car : How American cities are fighting congestion WOM Bs ea we we 130 Th Geniuses Wo CrEATED PLANEs oF Ain Heroes By H. A. Bruno 32 Aviati | High spots in the lives of famous aviation designers Risks Death ; — — Bi; a Ne . isks Death in Homemade Blimp . An Or Supway or 90,000 MILEs J" B y Robert E. Martin 34 First Air Truck Delivers Typewriters Fo The thrills and romantic history of pipe-line laying , a... gs 54 Mrraces—Nature’s Own Fakes Exposep . By H.C. North 37 Airplane Factories Swamped with M New discoveries about famous illusions — eee ew eA 16 é' Brivces Butt or Macic Dust By Earle Duffy 39 Students in Flying Record .... 54 Ph Wonders of the Concrete Age we live in New Air Endurance Mark Set. . . 54 ( 2 Air Explosion Peril Reduced. . . 54 Str Every Roor a LanpinG FIELD . 45 . , an Red Lights to Warn Flyers . . . . 54 ] An inventor's novel scheme to launch and land planes Flyer Safe in Four-Mile Fall. . . . 54 Ne Your Aviation QuESTiIONS— . es = &« @& « oe Navy Catapult Secrets Guarded . 55 f Answers to perplexing queries about flying ad oo a ay te ome aia 55 A : wo Planes Talk by io in Flight 55 ] Sam Loyp’s Puzzie Page .. . aa i oe ae ee Tied tel iens...- . 5 - Wuoxe Rooms Tuat Fotp Up... . By John R. McMahon 67 Airplane of 2,000 Years Ago... 55 . Disappearing beds and stairways for your home U.S. Takes All Helium Output . . 55 Spc Drivinc—Dozinc—Deat3!. , .By Martin Bunn 69 Upside Down Flying Record 55 y Gus and Joe warn the sleepy motorist ee Ocean ew Field 55 Keep in Minp Tues Ports Ir You Use Exectric Suppiy ror oe Seen Ses. ss § Your Rapio Raa sae" a ee 6 Exceptional People ” How Rocer Bares Investep His Mom EY. . By Wallace Ames 4 He’s Uncle Sam’s “Official Watch”. 41 lie FI re TI O N Priest Makes Safety Devices. . . . 88 Als Kidnapped by 500-Pound Fish. . . 56 I Turntable Cyclist ...... 58 Contact! , . By Armstrong Perry 18 ep ies a ; *% Tel How a Signal Corps. man saved a regiment Official Candy Eater... .... & Ele Warrune Wueeits—Part Four By Edmund M. Littell 42 Explorations | Ne Romance and automobile history in a stirring novel America Found 1000 B.C.? . . . et _ Metal Mirrors of Flappers in Ancient RADIO Greece Unearthed 47 | C is : ee Se ee La Aun Axsout Since Dra Controu . . By John Carr 62 Crusoe’s Island an Eden... . . cy st A SumpLe Power AMPLIFIER By Alfred P. Lane %6 Tenting on an Iceberg... . . . 53 AN THE HOME WORKSHOP _ Health and Hygiene a Mind Works Best When Tired. . . 369] ——— How To Do Decorative Merat Work . By Edward Thatcher %3 Oxygen Shortage Causes A Rapro Casrvet You Can But. . By Charles A. King 74 Stammering. ......... 40 Easy Ways To HanpieE Heavy Work. By H. L. Wheeler 78 4% Gainsin Medicine. ....... 40 November, 1927, Vol. 111, No. 5. Popeiec! Science Monthly is published month- United States, its possessions, and. Canada, $2.50; foreign countries, $3. Thé iy at 250 Fourth Avenue, New York, , by the Popular Science Publishing contents of this magazine must not be reprinted without permission. In pre ‘o., Inc. Entered as second-class LAD A Dec. 28, 1918, at the Post Office at senting in its editorial columns numerous stories of new products of apple New York under the act of March 3, 1879; additional entry as second-class science, Popular Science Monthly doés not underwrite the business methods matter at Chicago, Illinois. Entered as second-class matter at the Post Office of the individuals or concerns ———- them. The use of Popular Science Department, Canada. Printed in U. 8. 7 Copyright, 1927, by the Popular Monthly articles for stock-selling schemes is never authorized. O. B. Capel Science Publishing Co., Inc. Single copy, 25 cents. Yearly subscriptions to President and Treasurer; R. ©. Wilson, Vice-President; A. L. Cole, Secretary.

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H Ve’d 56 57 31 s of 49 51 52 59 70 70 70 70 is . . 14 Car .. & .—) or = ters vith ight KGGKGKAKKHKATASSSS = Sse ient ne POPULAR SCIENCE MONTHLY

Doctors Vindicate Hair Bob 46 % Full Novels on Phonograph Produced ¥ 2,000,000 Lepers in the World. . . 49 Sleeping Sickness Kills 5000 . 46 by New Process ........ 43 ee, or re 52 Electric Baths for Noses . . .. . 47 | Wire Stretcher Saves Fence . . 48 Home Heated by Sawdust. . . . . 52 Seasickness Laid to Plain Fear 48 | Rest for Overworked Tongue . . . 49 | How Much Do You Know of the Surgical Chisel Driven by Air . . . 48 | Ocean Undercurrents Filmed 49 World You Live In? ...... 53 ° “Foot Fins” Help Swimmer. . 49 | The Mechanical Stevedore 53 Laboratory Discoveries A Home Hair Clipper. . . . .. . 50 | One Wheel Rules Power of 80,000 Testing Food by Color. ..... 41 | Babies Rocked by Electricity . . . 50 ES ee aaa ee ee 56 May Solve Mystery of Magnet-Bent Blast Precools Fruit Cars... . . 50 | Suffocating Goldfish Saved .... 56 [agt Rays ........-.;-. 41 Gun Shoots Light Rays. .... . 50 | Cats and Dogs Color Blind .... 57 Seedless iaee Defies Winter . . . ‘46 | New Golfing Machine 50 | Milk Sold by the Chunk ...°*. . 57 Microbes Produce Cone a 48 a = ae Ee ie. bara a tose 50 | Snake Myths Spiked. ...... 57 Man Evolved from Dust, Not pes, New Bicycle Boat ........ 50 No Peril of World Starving . 57 ee a re 48 | Shocking by Foot ........ Si | A PomtioemGe «1.6 se 58 Hope Dashed for Gold in 7 49 | toy ne . ... 51 | Operatingona Dragon. .... . 58 Tine Clock Held on Soun 49 | Keyless Saxophone. ....... 51 | Ship Flirts with Iceberg... .. . 59 New Television Idea. ...... SB | AWolding Goat ......... 51 | Largest MobileGun ....... 59 Models ee + a a any Rh at Gatdes teh 51 as Is Made from Sawdust . . 51 Ship Made with Two Tools . . . 48 | Horse-Racing Odds Figured by For the Home Owner How to hn Ship Model Hulls for Mechanical Bookmaker ... . 52 | How to Beautify Your Fireplace. . 81 5s a yk eee . . 118 | New Gliding Effect on Piano 53 | Better Heating at Lower Cost . 84 Troubles Sith Overheated Cars . . 130 | “Mechanical Man” Gets Angry . 56 | Paper Hanging Made Easy . . 89 h Parr ll wa | —— ge 56 | Ventilating Hood Carries Off Cook- ' me asoline Engine for Freight . . . 56 a are 125 New D gio’ for C eH 4 Electric Landslide Alarms. . . . . 56 | Basement Storage Racks .... . 125 -_ kn b a , Removing the Dust from Industry . 57 | Window Ventilators ...... . 126 ~~ obi - le Ria Chair Folds into Package... . . 57 | Marking Your Screens .... . . 126 6 —" xtracts e4 | A Paint Gun ona Pole. ..... 57 Pers Oranges and Potatoes by Tum Super Locomotive ‘sss 981 Hints for the Mechanic TOT a eae ife-Saving Rocket. . . . . . . . 59 | System in Surface Grinding. . . . 112 Noviee Bread Knife Has Odd-Shaped 64 | Germans Make Gas from Sewage. . 154 | Easily Made Reel Holders Keep a ee eee ee ee Wee Ug csv ss. 6 eo os is h Reac Srealy- Dregne ice Cnet Photography Ning Ditul Oi Bikes’ © 11 Tea Strainer of Unusual Design Has fein sar ony sow ag pi = tiliee ston — yas: a Pouring Spout... . +. 64 . a eee, + Blue Color Gages Machining Speed. 114 This Spiralled Disk Keeps Your : Milk from Burning. ... . . . 64 Radio Finishing a Cast-Iron Fast ie Non-Tarnishable Eggs Spoons Save | | A Not Quite So Loud Speaker. . . 47 | Teft'Handed Filing Safest’ | | | | 114 " a — ar “Sed in 64 | How to Shield Your Receiver . 61 | Holder for Countersunk Screws . . 114 olding Window “Inserts e Queer Sources of Hum ...... 61 | Hunting Trouble in Shop Mot 115 . ‘ g Trouble in Shop Motors. . a . ‘in New Bottle % re pom ae Bee we . Convenient Holder for Valves to Be Nig oe ee Se tS ee SE NN i 36) <4 od. 26 ed hcrkn be a Se 116 | See ee 65 : : Box for Heating Small Parts with a Plunger on New Fork Drops Its §. | Unusual Facts and Ideas “oo 17 Ph sng oe “ Ta te Sets may, Basie ce aay ase as = — an for Hardening Ends of ia ; onograph’s Birthday. . ... . ng een rye ee N he a 9 One Out 65 Measuring to Shanghai. ..... 14 | Making Center Reamers in the th em ga 65 coe aes rere 14 ee ae eee 124 ee ane oa See Plood.a Dleming. .......%. 14 A Toothbrush Adjustable to Any es Parachute Tows the Baby. . . . . 31 Improved Cloties Reel with Ratchet “| Joys of a Bull-Fighter =. 1 | Mase See Sees Ty omen 65 Treadmill Trains Dogs to Run. . . 31 | Five Ways to Paint Tilt-Top Tables. 75 s . a fa, ae ee A One-Man Power Plant... . . 31 | Enter the Stage Carpenter 80 ad Cushing Whence 65 Air Liner Becomes Playhouse . . . 31 | Boring Guide Makes Furniture N p Seen Sixty-Foot Tower Built of Concrete ray ed nd (oS Se 82 To CN «6 4 4 + & e106 #6 * » 36 | Using Wood Screws... .... 86 ay Ae and ptr yay Give Electric Power. . . 40 | How 7 = om Se hea ae 92 Steel for Paving ......... 40 | What You Can Do wit alic Acid 100 New Rock Borer ........ 4 | Amteap Maem... . .. 25s 40 | Blueprints for Your Home Workshop 102 Light Rivals Sun. ........ 14 | ‘Blood Tells” in Animals, Too 41 | Quick Ways to Mix Paste and Trim Aluminum Plates Speed Map- Building Spires Doomed .... . 41 WO gos. sk to, ats 104 ete a, gab)... 40 | Dictaphone in Harbor Records Small Bending Dies for Sheet Metal Television Opera. ........ 40 I ss eta a eae we 46 Nae a se ee 106 Electric Plow Kills All Pests. 41 | Just a Rainy Day Railroad .. . 46 | Hintson Paper Hanging .... . 106 New Use for Vacuum Tubes. 41 | Fighting Gorilla, Doctor Finds Him A Roller Rack for Ties. ., ... 108 Fireman Dives in Gas Mask. . . 46 Rett-raemded. 2 ww tt ls 46 | What You Can Make with Wallboard 110 A Realistic Mechanical Football Nation’s Gas from One Plant . . . 47 | Handy Test Tube Rack for the ee oh ek a ke Cg 47 | Second Highest Dam Planned... . 48 Home Laboratory ....... 118 Lawn Mower of Razor Blades. . . 47 | Ship Made with Two Tools . . . . 48 | How to Finish Curtain Poles in Mechanical Ears” Beat Man’s. . 47 | Flameless Fire of Rust Causes Losses Polychrome Effects. . . . . . . 128 A Mail Box for Motorists. . . . . SB. Wit... 2 ta 49 @ “Comicull” Doll Has Clothespin Body 132

Hundreds of Striking Articles in This Single Issue Cover from Every Angle the Latest Developments in the World of Invention and Discovery

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EE POPULAR SCIENCE MONTHLY WHAT IS NEW THIS MONTH Table of Contents for December LEADING ARTICLES Russer rrom Wreeps My New Goat—Edison . By Frank Parker ‘Stockbridge The great inventor’s story of his latest research Atr-Ratt Lines May Span U.S. . By William P. MacCracken, Jr. Transportation of the future as seen by a high Government official Myrtus asout Mars ExpLopep . . By Donald H. Menzel A noted astronomer’s new description of the red planet Fieuttine Bap Bugs wit Goon . By John Walker Harrington Amazing ways insects save crops Marconi—Tue Fartuer or Rapto How transocean wireless “happened” Tue Human Minp Craves Wonvers . By Morris Fishbein, M.D. A medical authority’s explanation of the quack’s appeal Firty Years To Burtp Cuurcn . . . . By Jesse F. Gelders Why the newest cathedral will stand for twenty centuries Gerttine Reapy ror THE Next War .- By George Lee Dowd, Jr. New engines of destruction for tomorrow’s combats Watk East anp You Lose Weicar. . By Thomas M. Johnson Startling facts of “relativity” explained Sir Artuur Kerra Says Darwin Was Ricut By Edgar C. Wheeler An expert’s summary of the evidence for evolution CrotHes WoveEN From Rock. . By Orville H. Kneen Marvels of asbestos, the wonder mineral We.tper—New Taitor or STEEL .. . By L. G. Pope Forging industry’s structures with white-hot ‘metal “T’m Gorne To Senp My Boy to Cottece” . By J. B. Minnerly An answer to the claim that “higher education” doesn’t pay Huntine Witp Zesras wiTH Fisopotes . By Thomas W. Phelps How African zoo collectors succeeded when cowboys failed Aviation NEEps 10,000 Younc Men : By Caleb Johnson Why many besides pilots are wanted in the flying game How THe Hier Fryers Cums Strange equipment for man and motor in | altitude planes Sam Loyp’s Puzzue Pace. ‘yar ae ae ee ee Buitp ror Your Wire, But— . . By John R. McMahon Hints on avoiding costly alterations in your plans “Your Car Neep NEVER FREEZE” ' Gus and Joe discuss a pressing winter problem, New Rapio Propucts APPROVED BY PoPpULAR SCIENCE . Institute of Standards FINANCIAL ARTICLE. . . By Alden P. Armagnac . By Mariin Bunn By Wallace Ames * F ’ C bd ION Kaka AND Kaxkapo. By Andrew A. Caffrey Dizzy misadventures of the air Warriunc WHeets—Part Five . A thrillmg automobile romance in novel form RADIO Way Can’t I Ostarn Tone Quatity? THE HOME WORKSHOP At Last—Tue True Santa Marta. . By E. Armitage McCann New Ways To Decorate Grrts. . . . ._ . By Berton Elliot Mak1nG THE Most oF THE VEE . . By Henry Simon By Edmund M. Littell By Alfred P. Lane 25 26 28 29 31 34 37 43 45 66 67 69 17 40 62 73 74 78 Astronomy Boy Builds Own Telescope . Earth’s Speed May Vary Telescope of Plate Glass . Automobiles Motor Car Advance . Safety in Hub Light . Know Your Motor Car . Autos Built at Home of Junk, ‘Re- source, and Ingenuity. . . . Three-in-One Motor Trunk . Aluminum-Wheeled €ar Built in Spare Time . Water Pumps Tires . ‘ Fighting Snow on W indshields Cures Sagging Garage Doors Novel Secret Switch . Weatherstripping Your Garage . Ten Dollars for an Idea! . Aviation . Airplane Rains Men . . U. S. Deliberately Burns an ‘Air- lane. Half Plane, Half Dirigible Frame of Giant Air Liner Plane Crash Harmless Here . New Air Mapping Invention : Alarm Clock for Dozing Aeronauts . Skeleton Plane for Novices . Chicago-Mexico Air Mail . Macready May Win Record A Bomber’s Balloon Tires “Vest Pccket”’ Balloon Trip Nearly 5,000 Aviation Pupils Airdrome Afloat Nears Completion. Monoplane’s Unstrutted Wings Hold 17 Men . Good Airplanes Built in Many Good Designs . . ; Amphibian Commuting Planes . Propeller Serves As —_ Brake . Seaplane Kings ‘ Exceptional Peo om Champion Woman Nail Driver . Sprinter’s Sprinting Family . He Goes Fishing with a Kite . The Greatest Woman Cabinetmaker Explorations Volcanoe Island Alters Its Face. . Three Boats Battered to Bits Film- ing the Colorado Rapids / Bicycle Glacier Climbing Health and Hygiene Deaf Mute “Listens In”. . : Antitoxin Victor Over Erysipelas Tides of Blood Present Problem Ultra-Violet Window Panes . Year Breaks Health Record . Ses 47 47 59 70 70 70 70 70 SSS5 8 S882 Seese Ss SSS8B December, 1927, Vol. 111, No. 6. Poputer Science Monthly is published month- United States, its possessions, and Canada, $2.50; foreign countries, $3. ly at 250 Fourth Avenue, New York, N.Y., by the Popular Science Publishing contents of this magazine must not be reprinted without permission. In Inc. Entered as secon nd-ciass matter Dec. 28, 1918, at the Post Office at senting in its editorial columns numerous stories of new products of ap The ied New York under the act of March 3, 1879; additional entPy as second-class science, Popular Science Monthly does not underwrite the business methods matter at Chicago, Illinois. Entered as oe matter at the Post Office of the individuals or concerns producing them. Department, Canada. Printed in U. 8S. A. Copyright, 1927, by the Popular Monthly articles for stock-selling schemes is never sathermer. oO. Science Publishing Co., Inc. Single copy, 25 cents. Yearly ‘subscriptions to President and Treasurer; R. C. Wilson, Vice-President; A. L. Cole, Secretarh The use of syouser, Science Capen,

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POPULAR SCIENCE MONTHLY

Laboratory Discoveries uring to Billionth of Inch . . 14 — he on Fish Oil . . . 38 Tiniest Particle May Be Etheron . 39 Rain Making Yet Unachieved . . 39 Earthquakes to Order Next? . . 3D Testing New Cable Insulation . . 39 Mystery in Electric Vapor . . . 46 Wave Lengths of Elements . . . 48 Traffic Paint Endurance Test . . 49 A Window-Envelope Contest . . 49 Copper Hardened for Knives . . 52 Crickets Chirp T: emperature , 52 Ready to Breed Supermen, Says Noted Gland Expert . . 53 X-Rays Speed Evolution. . . . 53 X-Ray Catalogues Minerals. . 54 Aurora, 600 Miles in Air, Highest Ever Seen by Man ae 55 Measuring between Atoms 55 Mystery of the Blue Geese ¢ Solved | vad Science .. 57 Models Smallest Colliery . . . 2 te Ships Molded from Paper ; 58 Paper Models Help Design Amateur Stage Settings .. : { Building Airplane Models . . . 123 New Devices for the Home Handy Scissors Sharpener. . 64 A Breakfast Table Paper Rack. . 64 Pie Crust Mixer Is Woman’s Inven- tion .. 64 Sink Strainer Has Ingenious Fold- ing Cover. is Floor Lamp Tilts for Reading we A Window Lock You Can’t Force . 64 Holder for Darning Cotton . . . 64 Renovates YourFurs . . . . 64 This Soap Holder Floats. . . . 65 New Can Opener . 65 You Can Sit Up in This Volding Bed 65 Adjustable Rack for Pots and Pans 65 Fits the Candle to the Stick. . . 65 Double-Bottom Cooker Easy to Clean. : 65 Antiburglar Lock Attachment . . 65 Novel Bracelet Holds Yarn. . . 65 New Processes and Inventions This Lighthouse Tends Itself with Electrical Machinery . . . 46 Wrist Watch Winds Itself . .. . 46 Steam Clears Rails of Ice... 46 Thermos “Food Trolley” Carries Hospital Meals. . . . . . 47 Electric Eye Runs Factory . . . 47 A Boat That Can’t Capsize. . . 49 How to Tame Balky Wires . . 50 Ratchet Gives Bicycle High Speed . 50 Lightning Shorthand Typewriter . 50 Glass Violin String Case. . . . 50 Machine Tests Paint Brushes . . 51 Dustless Street Cleaning at Last . 51 New Economical Label Licker . . 51 4

A Mirror That Tells Your Height . 51 ® When Sea Gets Out of Gear . Machine Skins Wire in Hurry . . 51 “One Way Windows’ Invented. . 53 Nickel-in-Slot Soda Water counwns in Ten Flavors .. aoe Fertilizer Made of Cocoa. . . . 54 Gas Made from Water by New Electric Cell a. sé, ea Rubber from Cactus Juice. . . 58 Photography Camera Records Fly’s Footprints . 38 Speeding Bullets Can Be Filmed . 46 Color Photography Nearer . . . 47 A Screen for Home Movies. . . 135 Radio New Radio Photos . . » «2 ae Trees Cast “ Radio Shadows’ —— Plow Lays Radio Wire in Furrow . 50 Cooling Huge Radio Transmitting Tubes a Battle Tanks Talk by Radio . . 87 How to Build Your Own Electric Radio Receiver. . . + € What Limits Your Distance? = ae Emergency Battery Measures . . 61 Balancing Condensers .. . & New Socket for A. C. Tubes" é a! ae Unusual Facts and Ideas Ruined City of Tokio Rebuilt . . 14 New Aluminum Rival . . . . 38 Limits Seen for Television . . . 39 Test PoisonGas Masks . . . . 39 U. S. First in “Calamities”’ . 46 How Much Do You Know of the World You Live in? . . 46 Mica the Versatile Mineral . . . 47 Sharks Die in “Sea Desert”. . . 47 Trees Fight for Lives . . . . 47 A Bridge That Alters Shape. . . 48 Noisy Oysters Spoil Survey. . . 48 Bicyclist Has Trailer to C _ Children : . 49 “Hot Dogs” Capture England . . 49 Rubber Horseshoes . . . . 49 Native Foods Best . . . . 49 “Halfway to Heaven” on Fire Ladder . 51 Snail Is a Rip Van Winkle, Sleeping for ‘Twenty Years .. : 52 Lion “Packs” Hardest Punch . . 52 Lunch Wagon Trails Patrons . . 52 Industry Shifts Westward . . . 52 Two-Mile Bridge Projected . . . 52 A Theater Curtain of Water . . 53 World’s Smallest Scissors . . . 53 Building a Hippopotamus . . . 53 A Church ona Chassis . . . . 53 Gigantic Water Lilies . . . . 54 Tiniest Iceless Refrigerator . . 54 Queer Rivers That Fail in Attempts to Reach Sea .. : 54 Oil Tanks Made into Houses . . 54 Broadway Glare’s 49 Rivals. . . 55 How Not to Clean Dress . . . 55 What Do You Want to Know?. . 55 Earth Tides Likened to Sea’s . . 56 “Vacuum Bottle” Buildings . . Ba

} Cutting Odd Shapes i in Glass Bridging the Hudson at Last . . Race Horses with Glasses Run Fast- Oe i et Flies Go Six Miles a Day Plant Punctures Tires . . Census of Lightning Flashes . A Housetop Farm Chrysanthemums a Foot in Width . For the Home Owner Concrete Houses While You Wait . Why Hot Water Pipes Freeze First . Filter for Purifying Cistern Water . A Workmanlike bot to —_—* Wall- Board : Storing Screens in a Garage . A Back Yard Incinerator ‘ Making Locks for Window Sashes . A Prop for Your Clothesline Patching Metal Roofs Remedy for Sagging Doors .

60 60 111 113 . 118 121 121 . 122 . 122 . 128 Hints for the Mechanic Quick-Acting Holder for Short Weld- ing Rods Clip for Vise Expedites Filing of Thin Work... ; Clamp Puller for Shafts... Making French Curves for Drafting Use . Hooklike Tool for Repairing Hy- drants Quickly Sockets Placed in Concrete Floor to Save Drilling j Lathe Used in Emergency to Cut Long Keyway . : Grinding Taper Shanks on Arbors . 114 114 114 115 115 115 116 116 Ideas for the Handy Man A Christmas Doll’s House F New Ways to Light Your Tree . Metal Work for Beginners. How I Built a Desk from Scraps. A Simply Made Push Sled for Baby Restoring Antique Furniture. Hints on Laying Out a Home Work- shop Compactly_. A Joint You Can Take Apart Kaleidoscope Made at Trifling Cost How to Stripe Furniture How to Make a Tool Case : Pencil Holder Improves Marking Gage. . ‘ Oil in the Home Workshop A Blueprints for Your Home W ork- shop . How to Drive Your Tool Grinder by Foot Power . Emergency Repair for Hacksaw’ lade. How to Fasten Light Fixtures to a Cement Wall or Floor. . Wood Filler Gives Two-Tone Effect Ball Bearings Used as Wheels for Scooter How to Rig Up a Simple Telegraph Line . 75 76 80 81 84 86 88 94 95 95 96 99 100 102 112 121 127 128 135 136 . 186

Hundreds of Striking Articles in This Single Issue Cover from Every Angle the Latest Developments in the W orld of Invention and Discovery

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july, } 2 RR VIRB OT o nm. NS MA!

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POPULAR SCIENCE MONTHLY 1 \ - - Oh S Campagne OF THE HOUR—YET 25-YEARS PROVED With a quarter~century of quality slightly lesser wheel base than Cadillac, experience behind it, besides being the the La Salle is powered by the 90-de- smartest automobile of the hour, the La gree, V-type, eight-cylinder engine for Salleis Cadillac in its finest essence. Of which Cadillac has long been famous. FOR A SMALL DOWN PAYMENT—with the appraisal value of your used car acceptable as cash— you may possess a La Salle on the liberal term payment plan of the General Motors Acceptance Corporation—the famous G. M. A. S plan From $2495 to $2685, f. Oo. b. Detroit ay )LA SALLE 4 CADILLAC MOTOR CAR COMPANY DETROIT, MICHIGAN , OSHAWA, CANADA Division of General Motors Corporation Ge MANUFACTURED + COMPLETELY *BY *THE *CADILLAC * MOTOR’ CAR * COMPANY ¢ WITHIN 4 1TS *OWN * PLANTS @. This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS... See page 6.

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——_— | | | | i | = POPULAR SCIENCE MONTHLY WHAT IS NEW THIS MONTH Table of Contents for July LEADING ARTICLES Wrre.ess Power—Tue Next Great INVENTION , By Alden P. Armagnac Will radio and earth currents soon run the world’s engines? How Fioops CHALLENGE ScIENCE By Edgar C. Wheeler What science has learned from a great disaster Tue Larcest PackaGce Ever SHIPPED . The story of a remarkable engineering feat CANNED Foop anp Your HEAttu . By Thomas M. Johnson An informative article on the diet question Stock Cars Testep in Reat Races. . By Joseph S. Edgerton How speed trials point the way to better automobiles A New Era or Huce Brinces , . By Orville H. Kneen A famous engineer tells why men now can build mile-long spans Courters Tuat Never Fart... By Jack O’ Donnell Why the tireless homing pigeon is man’s valued friend Wuat Game Do You Ptiay? . . By Arthur Grahame A discussion of the “danger age”’ in -- BRONCHO-BUSTERS OF THE AIR. : By Cy Caldwell What happens when a test pilot tries ‘out a new plane Guenn Curtiss Szes a Vision oF AviaTIon’s Future . Reported by Frank Parker Stockbridge Startling predictions by a pioneer birdman Uncie Sam’s Toy Coat Mine... Where Government scientists test mining hazards By M. E. Clements His StraANGE Woritp CAME TRUE .. By Don Knowlton How modern wonders vindicate Jules Verne’s ; amazing prophecies Sam Loyn’s Puzzie Pace Is Your House Too Hor or Cotp? New discoveries about the uses of insulation By John R. McMahon Stop THE Noises tn Your Car . By Martin Bunn Gus and Joe tell how to trace rattles and squeaks Tue ADVANTAGE OF Group MANAGEMENT TO THE Pustic UTILity INVESTOR . By Wallace Ames Wuat Is a Goop ary By Carlos de Zafra FICTION Curer oF BATTALION . By Karl W. Detzer The thrills and science of fire-fighting portray ed in a graphic story Bare Hanps—Parti5d. . By Hawthorne Daniel A gripping novel of man’s conquest of Nature RADIO Perrect “A” Current ror Your Rapio . By Alfred P. Lane You Neep a LicutninG ARRESTER . As told to Newton Burlce THE HOME WORKSHOP . By Berton Elliot By Everett Eames By F. 8. Browning How to Apprty Art TRANSFERS . Buripine A CorNER CLOSET Hints on Usine Taps anp Dies 40 61 63 73 74 b Automobiles A Highway on the Roof Tops Tests Autoist’s Footwork Ignition Hints for Your Car . New Auto Motor . “Taxis’’ Old and New in the Sehewe Theater Teaches Traffic Laws Odd Cycle-Auto Solves Gas Problem Rollers for Grade Crossings . Measure Auto Seat’s Bumps Novel Siphon Starter . Screen Your Car . er Switch to Control Generator Pedal Extension Easy to Build . A Table for the Auto Lunch Rope Luggage Carrier Aviation Fly Own Gliders in Novel Club . Trans-Ocean Airmen Crash in Test Flight A Triple-Purpose War Plane French Build “Ghost” Plane Our First Ocean Air Liner? . Germans Have Flying Yacht Exceptional People He’s America’s Orchid King! She Makes Bike Tires . Makes Table of 51,000 Parts He “Clocks” the Big Races . Lumberman Models Forest Crea- tures in Wood To Cross Ocean in Sailboat : Loops the Loop in Auto . Commands Arctic Ship Uses Homemade Diving Helmet He Makes Intricate Glass Appa- ratus . oe D Girl Daredevil Rivals She Health and Hygiene What Your Nervous meee Looks Like. . Does a aN Ww ave 7 Y our Hair? How Do You Sleep? Soap as a Germ-Killer Deaths from Heart Disease . Healing with Music Salt “Peps Up” Miners . Don’t Listen with Your Eyes New Diabetes waned nen Insulin 68 68 13 July 1927, Vol. 111, No. 1. Popular Science Monthly is peptic’ wee monthly 50 Fourth Avenue, New York, N. Y., by the Popular Selence Publishing > Ine. tered as second-class matter Dee. 28, , at 2 Post Omee at New York under the act of March. 3, 1879; Gaditional Pt second-class matter at Chicago, Illinois. Entered as second-class matter at ithe Po Post Office Bipartenens Canada. Printed in U. 8. A. Copyright, 1927, = the Popular Science Publishing Co., Inc. Single copy, 25 cents. Yearly subscriptions to President and Treasurer; United States, its possessions, and Canada, $2.50; foreign countries, $3. contents of this magazine must not be reprinted without permission. In pre- senting in its editorial columns numerous stories of new eee 2 of = science, Popular Science Monthly does not underwrite the b of the individuals or concerns producing Monthly articles for ae schemes is never authorized. O. B. them. The — ied The use of Peoatar ‘Selene Capen, . Wilson, Vice-President; A. L. Cole, Secretary. — July, —

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43 44 44 . 46 n 48 . 49 n 51 53 55 68 68 68 68 68 68 13 13 45 47 52 53 34 34 35 48 49 51 52 52 POPULAR SCIENCE MONTHLY In This Single Issue We Publish More Than 250 Articles Depicting the Latest Achtevements and Discoveries in the World of Science and Invention Students Take Poison in Test How Does Noise Affect a Typist? Blood 1/2 of a Man’s Weight Laboratory Discoveries A New Electric Insulator Earth’s Bulgings Studied Ethylene as a Fruit Ripener Cathode Rays Dry Paint Oils Engineers Study “Cold Light” Whitewashes Defy Heat. . Test Machines in ‘‘ Padded Cell’ ° Science Explains “ Bloody Rains” New Processes and Inventions It Sees through Darkness and Fog. New Microscope Lamp Pullmans Substitute a for Berths. ; arene Electric Hole Saw It Measures Furnace Heat Shows When Gas Is Poor Ingenious Combination Tool Three Lanterns in One! . Blocks Improve Acoustics . Paper from Old Dollar Bills . Cutting Steel with Iron . Novel Device Compares F ingerprints New Ultra-Violet Lamp Detects FalseGems ._. Colored Lights Teach Piano . Life Preserver Instantly Inflated New Fire Engine Uses Soap Suds Machine Tests Boxer’s Punch Tobacco Chemically Made “Eraser Key” Aids Typists . Vise Holds at Any Angle Odd Apparatus Produces 7 New Music”’ ; New Devices for the Home A Furnace That Feeds Itself. Are You Planning to Buy an Oil Burner? ._. , New Fork Has Automatic Ejector Oversize “‘Tea Ball’ Cooks Rice Cup-Size Egg Beater... Wide-Rim Pie Plate Can’t Spill Juice Candy Making Instrument Set. . Versatile Traveling Iron . Metal Ring SavesGas .. New Cake Pan Has Window A Bath for Your Razor Blades . New Electric Mixer Saves Work . Electric Dishwasher Has sates Ca- pacity . ; : Rolls Out Doughnuts Automatic Safety Iron Stand An Unusual Electric Fan for Your Table. ; Card Table Folds by Single Leg . . Electric Range Runs Automatically Photogra phy Send Color Photos by Wire . Movies That “Live” ‘ Stomach Can Be Photographed . Lessens Movie Film Breakage “Movies” Preserve County Records 54% Radio ¥ Measuring Angles with Extreme 54 Accuracy . 105 57 | Broadcasting from Balloons. . . 35 What Causes Chatter Marks 105 New York’s Storm Detector . . 45 How to Use a Diamond for Trueing World’s Biggest Vacuum Tube . . 46 Grinding Wheels . 105 “Mystery” Burglar Alarm . . . 47 | Guard for Tapeline Case Made from 34 | Has Radio Wave Allto Himself . 55 Old Inner Tube. 105 34 | How to Choose Condensers. . . 60 | Pocket First Aid Kit Goes in Small 34 | Be Sure to Havea Good Ground . 60 Razor Case. . 106 35 | ABC’sof Radio. . . . 60 | Expanding Chuck for Use in Fin- oS 4. ished Holes. . 107 a U I sc 2 sp Horse for ‘Shop ‘Use ade of Iron Bars. 107 49 nusual Facts and Ideas Grinding Chucking Reamers 107 Blowing Up a Mountain 12 | How to Straighten Hardened Parts 108 Six Hundred Foot Leap by Balloon Using Micrometer to Measure Work Jumper. . . 12 with Concave Face. 108 Whippet Beats a Race Horse . . 12 | Shect’ Metal Holder Keeps / Acid 12 World’s Largest Submarine .. 12 Bottle from Spilling . . 108 5 Firemen Test Water Pressure 500 Lengthening Short T-Bolts._. . 108 : Feet above Street. . . . . 13 | Using Twin Angle Plates to Mount 39 | A Motor “What-Is-It” . a Lathe Work . : 109 44 | Lraffic Cops of Other Lands . . 30 | Soft Jaws for Lathe Chuck. 109 44 es beg | of Ae a ee i = Smoke War On in New York . . 3 a U.S. Sends Most Telegrams . . 34 Ideas f or the Handy Man 45 Cat Has Nerves Extracted . . . 35 | A Driveway for Your Garage . 75 46 Wealth Wasted in Lightning . . 35 | Swinging Seat for Campers. 76 4g | Houses of Rammed Earth . . . 44 | “Tuckaway” Canvas Bed. . 76 47 Gold Plucked from Air . . 45 | How to Make a F tte -Friction 50 Is Quiet Necessary for Good ‘Golf? 48 Set 76 Ice Lowers 16-Ton Floor . . . 48 Airplane Weather Vane. . 76 59 | Armor for Matador’s Horse .. 48 | Rowboat Anchor for Fishermen 76 50 Brushes from Chinese Pigs . . . 48 Hammering Out a Porch Lantern. 81 51 To Remove Unwanted Grass . . 48 | Replacing Jackknife Handles 2 ae 51 Salt Lake Changes into Fresh . . 48 | Rubber Cement Mends Torn Hunt- 59 | Staging a Deer Rodeo . . 49 ing Coat Invisibly. . 82 52 | Ship Plastered with Oysters . ; 49 | Gimlet Bit Serves as Pipe-C leaner. 82 53 | Deposits by C hute in Burglar-Proof Flaming Letters Light Camp _. 84 53 Bank. . : 50 | Ground Glass Substitute Easily : Carries His Own Breeze. . . . 50 Made . pes 54 Biggest Crane Afloat. . . in Building a Sturdy Porch Swi ing 86 **Smell-Meter”’ to Fight Bugs . . §2 | Tiny Decorative Galleon Has Wal- Music Sets Off Powerful Explosive . 52 nut Shell Hull. . 87 Gyroscope for Giant Yacht . . . 52 | How to Lock a Dial "Telephone 46 | Find Mummy in Ohio Cave. . . 52 Against Unauthorized Use . . 87 Puncture Vine Spreads East . . 53 Painted Glass Checkerboard 89 56 | Industry Now Uses Garnet .. 53 | Oversize Glueing Clamps 89 58 .| Recording Languages for Posterity . 55 A Square Peg in a Round Hole. 90 58 | Falling Meteor Misses Cyclist . . 56 | How to Solve the ama Science 58 | Male Birds Hatch Eggs. . . . 56 Block Puzzle .. 90 53 | ‘Wheel of Seven Sad Sounds” . . 56 | Tool Rack of Pipe Straps ‘ 90 58 | YouCan’t Tell’Em Apart . . . 56 a a for Your Home Work- 58 | Six Musical Instruments in One! . 56 hop. 91 58 | A Diamond Rushin Action. . . 57 anae Candle Propels Fireworks 58 | New Depthsfor Oil Wells . . . 57 Barge 93 59 | Doll’s House in Match Box. . 57 | High Power Fruit Press Made with 59 | Sixteen-Ton Bridge Holds Sixty-Ton Auto Jack and Rim . 93 House . 57 | Our Viking Ship Model . 94 59 | U.S. Phones England a Sample Toot 57 | Aerial Top Made with Spools ‘and 59 | Building er —_ a Giant Clothespin . . 59 Task. . 64 | Acetone in the Home W. orkshop 97 How to Make a Paneled Chest. 98 59 ee Toy Glider Folded from Let- 7 "1 ter Pa a r Hints f or the Mechanic C-Clamp Made from Large Nut . 99 Holder for Small Taps Made from Neat Wooden Stand Holds Watch Auto Valve. 104 at Night. 100 A Small Shop Method for Tapping How toGrind Smooth Holes Through 34 Nuts Quickly .. 104 Plate Glass. . . 100 44 | Inside Calipers Serve as Surface Window “Curtains” for Garage 101 49 Gage in Emergency . . 104 | Convenient Gate Latch. . . 101 52 | An Angle-Iron Timber Hanger. 104 | How to Take Care of Paint Brushes. 102 64 4 Why a Tap Breaks . . 105 § Preserving Large Corks. ; 103

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4 POPULAR SCIENCE MONTHLY July, 1927 Why Public Utility Securities are a GOOD INVESTMENT for YOu By WALLACE AMES, Financial Editor ” ELL! Here’s news!”’ exclaimed Fred Johnson as he and his wife sat down in the living room one evening after dinner and he started to read the local newspaper. ‘“‘Our electric light company has been sold. Bought by some big interests back East. Wonder what that means. I hope we et better service. Perhaps we will, ut I'll bet it will cost us more,” Fred concluded rather skeptically. Two months later. The front door opened and Fred rushed in. “‘Did you ever see such a night! Hear that wind! See that hail beating against the windows! Gee! I’m glad I got home! If this keeps up there won't be a tree or a wire left standing in this town by morning.”’ ; The storm’s damage was worse and came sooner than Fred expected. By eight o'clock that night the electric light service was Te gees demoral- ized and every family in the town was fumbling around in candle light. *‘This reminds me of the hurricane five years ago,’’ said Fred. Remember that? The electric light plant was out of commission for over a month. Wonder how long we will be in the dark this time.”’ Now Fred Johnson was going to find out, at least in part, what it meant to have the local light plant managed by the ‘‘big interests."’ Within an hour of the time that local service was interrupted by the storm, emergency messages were on their way in every direction to numerous other companies all under the same manage- ment. By morning over a hundred line-men, engineers and other workers were OS on the one job and in four days full service was resumed. This is just one example of the effect of group management of public utility properties. There are numberless others. What does it all mean to the investor? Let us see. HE electric light and P rgd in- dustry is only about forty years old. At the beginning small, inde- pendent companies were established in various towns and cities. Each one struggled along alone, as best it could, unaided by the others. Service was often inefficient, limited, undependable as also were profits to the companies. Then the era of group management started. A number of utility prop- erties, usually in the same territory, were brought under the control and operating management of one central organization. Generally the com- bined properties were in adjoining A Service for Readers of POPULAR SCIENCE MONTHLY HIS Department is to help readers in the establish- ment of proper financial pro- grams at the beginning of their business careers; it assists those who have accumulated money in the proper investment of it so that it will be safe and so that it will grow. The Editor of this Department is an authority on investment matters and he will not only every month give the readers interesting and useful informa- tion in his articles, but is also ready to aid in personal invest- ment problems. Advice will be gladly given regarding the proper investment of funds and proper plans of saving. Address all your inquiries to Wallace Ames, Financial Editor, POPULAR SCIENCE MONTHLY, 250 Fourth Avenue, New York. Any advertising appearing in this section will be carefully in- vestigated by the Publisher of POPULAR SCIENCE MONTHLY. Readers can be sure that com- panies advertising are reliable and that they offer securities which represent sound financial investments. While investments obviously cannot be guaranteed by the Publisher, every effort will be made to insure that only advertisements of ab- solutely reliable companies are accepted. towns. A lot of small (and often weak) companies were combined to- gether and made into one big, strong company. ith a number of generating plants connected up, better service to the en- tire territory is assured. If one plant breaks down electric current can be supplied from other plants without interruption of service. One of the problems of a light and power company is to keep as even a demand as possible for current every day in the week and every hour of the day. In one community the big demand might be at night, in an- other case it would come in the morn- ing, and soon. When a large territory is served by one company, or com- bined group of companies, it is easier to average the demand on each gener- ating plant. During the peak demand in one community, a manufacturing center, for. instance, power could be drawn from not only the local plant, but from others which otherwise would be operating at but a fraction of their capacity. | companies can afford to employ more skilled engineers and manag- ers because their services are spread over wider fields. This has resulted in im- provements which small independent companies could not hope for. And, as the example related earlier in this article shows, the operating staff of each individual property is reinforced by the operating staff of the parent organization. Plant and equipment is more modernized and kept in a more perfect state of repair. The general effect of group manage- ment of utilities has not only resulted in improved service to customers, but in cheaper service. Everyone knows how. wages, cost of coal and com- modities have increased since 1913. The public utilities have had to meet these rising costs. Yet the retail cost of electricity was 7.4 cents per kw.h. in 1926 as compared to 8.7 in 1913. This is a decrease of about 15%. If you take into consideration the value of the 1913 dollar present rates are about 4.2 or a decrease of 52% over rates in 1913. Big companies, byying in larger uantities, naturally buy at more Soondiie prices. But this is not the only means of saving. Generating and combustion machinery has been improved under the study of skilled engineers and thus millions of tons of coal have been saved. In communities adapted to it, water power has been July, oF. by i Full; 250 Fe

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ily, 1927 -S ie U can be rithout light cep as current y hour ty the in an- morn- rritory ’ com- easier gener- emand turing ild be plant, “rwise action mploy anag- Joull in im- ndent And, 1 this aff of ‘orced arent ent is more nage- ulted ;, but nows com- 1913. meet cost ities been July, 1927 etire Mn l 5 Years on your Present living Budget by investing in safe 64% First Mortgage Bonds Follow the definite plan given in this book, and your financial independence is won. The plan works just as surely, whether you are now earning $1,000 or $100,000 a year. The way is certain—each step plainly indicated and absolutely safe—inde- pendent of luck, business genius or speculation. Every fact has been harvested out of the 46 years’ experience of Cochran & McCluer in the first mortgage invest- ment banking business. The plan is so simple, anyone can understand it—so definite anyone can followit—and socertain, noonecan fail. In addition to the Financial Independ- ence Plan and the unique budget schedule, the book gives suggestions that enable you to enjoy more of the good things of life, both while build- ing your independent fortune and after you have attained it. We invite the most skeptical to read this plain, straightforward, interesting book. Send coupon. We employ no sales- men, therefore none will call. GOSS eee re se TT f Cochran & McCluer Co. 8) 46 N. Dearborn St., Chicago, Ill. ; Please send me, without obligation, d your book, ‘‘Behind The Scenes Where Bonds Are Made.”’ | See er Lieeseeeeeeeee eee eee Cochran &M‘Cluer Co. Established 1881—Never a loss to any investor. 46 North Dearborn Street, CHICAGO Construction of Small Alternating Current Motors By PROF. A. E. WATSON Brown University This book contains complete instructions for building small al- ternating current motors in several sizes. The designs will be found in harmony with those of the very best manufacturers and they can be worked out by the amateur for making useful instruments. Fully Illustrated. Price, $1.50 POPULAR SCIENCE MONTHLY 250 Fourth Ave. New York City POPULAR SCIENCE MONTHLY Why Public Utility Shares Ate a Good Investment. (Continued from page 4) harnessed and is producing millions of horsepower without burning coal or employing much labor. The average yield on well secured ee utility investments is coming own. According to skilled opinion this class of security will before long yield about the same as seasoned railroad investments. At the present time well secured public atilisy bonds yield 5% to 544%. Not long ago most of them were on a 6% basis or higher. It is still — to buy public utility pre- ferred stock to yield 7%, but many of them now pay 614% or 6%. The in- vestor of the future will probably not get as high a return on his public utility securities as he can get [ in- vesting today. The leading investment banking organizations of the United States, with few exceptions, deal in public utility bonds and preferred stock. These bankers are within reach of every in- vestor. Their offices and bra: ches are in all principal cities and their sales- men cover a large part of the Country. And they have facilities for dealing by mail with investors who cannot easily be reached by representatives. If you deal with a reputable invest- ment banker (and it is not difficult to establish the fact) you may rest as- sured that each investment has been thoroughly investigated before it is offered to the public. An investment banker plans to be in business per- manently. He is dependent on the good will of his customers. Their good will and his future depend on his selling satisfactory investments. Most public utilities sell their pre- ferred stock direct to the customers whom they serve with power and light. In fact this movement, known as the Customer Ownership plan, has so spread since the war that upwards of one and one-half millions of people own over twelve and one-half million shares of public utility stock. To Help You Get Ahead Mowe Booklets listed below will help every family in laying out a financial plan. They will be sent on request. The House Behind the Bonds reminds the in- vestor of the importance, not only of studying the investment, but of checking up the banker who ofers it. Address: Fidelity Bond & Mortgag: Co., 1188 New York Life Building, Chicago, Ill. Behind the Scenes where Bonds Are Made tells how you can retire in fifteen years and have an income equal to your present living budget. This booklet can be secured by writing to Cochran and McCluer Company, 46 North Dearborn Street, Chicago, Ill. a Why Investors THE WORLD OVER SELECT SMITH BONDS HY is it that men and women all over the world, in 48 States and in 51 countries and territories abroad, are as of one mind in their choice of SmirH Bonps? The reasons can be stated briefly: SmitH Bonps give you the essen- tials of successful investing—safety and ample return—614% interest with strong first mortgage security. Confidence in SMITH BONDS is World-Wide These essentials are not all. Where- ever the mails carry,: our Mail Service Department, in Washing- ton, D. C., enables you to have your investments handled by mail with the same individual attention and cooperation that you would receive if you called at one of our offices. 63/ whether you invest ? O much or little Another reason: Denominations of $1,000, $500 and $100, and Invest- ment Savings Plan payments of $10, $20, $30 or more a month, place 614% Situ Bonps within easy reach of every investor. Regular monthly payments earn the full rate of bond interest. Mail the form below for two booklets —one explaining the safeguards that protect every investor in our First Mortgage Bonds, the other showing how your monthly savings will grow at 64%. THE F H. SMITH Co. CONTINENTAL & COMMERCIAL BANK PHILADELPHIA B@STON 8ST. LOUIS PITTSBURGH Founded 1873 SMITH BLDG., WASHINGTON, D.C. 285 MADISON AVE., NEW YORK, N.Y. BLDG., CHICAGO, ILL. BUFFALO MINNEAPOLIS ALBANY Seem eee meee eee ee HEHEHE EH EE HEHE HEHEHE TEES See eee Hee ERE E EE HEHE EEE HEHEHE EEEES © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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at Isa GOOD LATHE? POPULAR SCIENCE MONTHLY July, 1927 By CarLos DE ZAFRA, M. E. Assistant Director Popular Science Institute of Standards HERE is just as much difference between a good lathe upon which accurate work may be turned out and a poor one, as there is between any other good and poor quality tool. Small parts for model making, and repair parts for precision work cannot be accurately turned out from a cheaply made lathe. And, in order to determine the ac- curacy of a lathe, there are a great number of items which must be checked upon—the exact number de- pending on the simplicity or complic- ity of its design and type. To per- form all the various tests that the Pop- ular Science Institute of Standards con- siders essential for a thorough check- up of a lathe requires considerable equipment including squares, gages, arbors, scribes and so forth. Among the first things done is to determine the setting of the lathe by longitudinal and lateral leveling. The swing over the “‘V’s’’ and over the carriage, and the maximum dis- tance between centers give a check upon the capacity of the lathe. Next, the Institute checks up on the fitting of the headstock, the tail- stock, and the carriage on the ‘*V’s’’ is checked up, as these should fit snugly and yet ——g of easy adjustment without play. MONG other items about which the tester must satisfy himself are: Have the headstock, tailstock and catriage been planted properly, the V's’ shaped to the proper angle and the “"V’s’’ of the bed scraped true and straight? Is the live center exactly true, and is the center bearing in the live spindle axially true with its spindle? Is the live spindle exactly parallel with the “‘V’s”’ in both hor1- zontal and vertical planes? Does the carriage move exactly at right angles to the “‘V’s’’? Is the tail spindle exactly parallel with the ‘V's’ in both the horizontal and vertical planes? Are the head and tail centers exactly in line? Is the faceplate exact- ly true? Is the faceplate exactly at right angles to the line of centers? In all, there are some forty points of inspection on the ordinary screw cutting lathe while a still greater © Popular Science Monthly GUARANTEE The above seal on an advertisement indicates that the products referred to have been approved after test by the Popular Science Institute of Standards. opuLaR Science MonrTHLy guaran- tees every articie of merchandise ad- vertised in its columns. Readers who buy products advertised in Poputar Science Montsaiy may expect them to give absolute satisfaction under normal and proper use. Our readers in buying these products are guar- anteed this satisfaction by Poputar Science Montuiy. THE PusiisHers Engineers are here shown testing 4 lathe in the laboratory of the Popular Science Institute of Standards. These tests cover some forty points and determine definitely whether the lathe is a good one or not number must be checked in the case of lathes with special attachments and accessories. In addition to the above, careful inspection and examination are made by the Institute of Standards’ Engineers to ascertain the appearance of scraped and of polished surfaces, as to finished corners being properly rounded, width on cone steps, change gears fitting stud properly, and uniformity of size of squires for wrenches. FTER such inspection, the lathe is actually operated and employed in doing some work which will de- termine the degree of accuracy of its work, as a check against whatever the previous inspection may or may not have disclosed. In short, the test- ing of any machine tool is very much like the thorough physical examina- tion that a physician gives a patient. Certain characteristics are looked for first of all, and the examination is progressive and complete. A lathe that can successfully pass such tests is nec- essarily a good one that can be safely purchased. The Popular Science Institute has prepared a list of the machine and hand tools that have its approval as the result of satisfactory test findings. This, and also similar lists of radi and oil burning equipment are avail- able on request. Readers of the maga- zine who wish to obtain such lists of would like information about these different types of equipment should address their inquiries to the Popular Science Institute of Standards, Two hundred and fifty, Fourth Avenue, New York, New York, July

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ly, 1927 a lathe Scéence ts cover finitely or not case of ts and careful > made yineers craped nished width 1g stud ize of athe is ployed ill de- of its latever ir may 1e test- - much amina- atient. ced for ‘ion 1s he that is nec- safely te has 1e and val as dings. radia avail- maga- lists or ; these should opular , Lwo e, New July, 1927 POPULAR SCIENCE MONTHLY Whether you have a beard ‘‘like wire” or as soft as silk, your GOOD shave will become a PERFECT shave if you read “Three Reasons.’’ On request we will gladly send you a copy, free. z'5) This seal on a radio, tool or oil burner“advertise Some men hurry ... others take their time —the nature of the skin and beard of every man differs from his neighbor’s. The New Improved Gillette makes shaving comfortable and enjoyable to ALL. It has a shaving edge with ample KNOWN THE EFACES ARE ai hd a NOT ALIKE aa space beneath to receive shaved hair and lather without clog- ging; (2) an adjustability of shaving edge so precise as to micrometric exactness mensions that makes it the hand-tailored razor for your face... Get a New- Improved Gillette today and your shay- ing troubles are over. THE GILLETTE SAFETY RAZOR CO. BOSTON, U. 8S. Ae WORLD OVER men: signifies the approval of the INSTITUTE OF STANDARDS. Seepage 6.

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s POPULAR SCIENCE MONTHLY July, 1927 Five-tube set for aerial or loop. Priced at °95 * ibenged sales and consequent lowered manufacturing costs now enable dealers to offer the Grebe Synchro- phase at $95.00. Only the price is changed. There is the same remarkable tone quality and reception efficiency — the same eas station finding of its one dial control— that have long made the Synchrophase the dominant receiver in the better set field. Send jor Booklet P. Then have your dealer demonstrate the exclusive Grebe features. A. H. Grebe © Co., Inc. 109 West 57th St., New York City Factory: Richmond Hill, N. Y. Western Branch: 443 So. San Pedro St., Los Angeles, Calif. The oldest exclusive radio manufacturer : ‘ SSSyNCHROPHASE , TRADE MARK REG. US. PAT. OFF. . Grebe Socket Power , 2 LNIDU@ Dcotoee ere ( power, ample voltage to (09) operate 180-volt power tube; self-adjusting, quiet. For any 5and 6-tube re- ceiver and the Synchro- phase Seven; 110 volts, th} d()}) 60 cycles A.C. Without BH theca tube, $50. © , TRADE MARK y = REO.US PAT. OFF. PG Be cee

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July, 1927 i ALL JULY, 1927 SUMNER N.BLOSSOM Editor VOL. III, NO. I Wireless Power— The Next Great Invention Electrical Experts, in Amazing Experiments, Reveal How Radio Beams Soon May Light and Heat Our Homes By ALDEN P. ARMAGNAC N A New York lecture hall a few nights ago, a group of engineers watched a scientist raise in nis hand an electric light bulb. To it was at- tached a four-foot copper rod. A short distance away a radio vacuum tube was turned on—and_ instantly the buib glowed brilliantly! This was “radio power,” dream of scientists. On a laboratory scale, Dr. Phil- lips Thomas, research engi- neer of the Westinghouse Electric and Manufactur- ing Company, had demon- strated before the New York Electrical Society how near scientists had come to the transmission of energy without wires between cities and across country. Tomorrow, radio beams of power may light and heat your home. Electric waves surging without wires through the earth and the ether may drive airplanes, automobiles and trains. In- stead of the present un- economical use of coal in small power plants scat- tered through every coun- try, a few monster central stations may generate all of the world’s power, which may be tapped by an aerial or a grounded wire at any point on the earth’s surface. Isolated homes as well as the factories ‘of a metropolis will share equally in the wealth of available power by wireless. Such a prophecy for the future is well within the limits of possibility, in this wonder age of science. A few months Courtesy New York Electrical Society Wireless light and power already have been achieved in the laboratory. Here Dr. Phillips Thomas, research engineer of the Westinghouse Electric and Manufacturing Company, is using radio impulses from the vacuum tube at left to light a small electric lamp attached to a copper “‘aerial’’ rod ago, no one dreamed that soon you would be able to see by radio—yet now we have television! Will radio power be the next great invention? Many scientists are at work on it today—and at any moment it may be realized on a practical scale. The idea of transmitting power with- out wires is not new. Heinrich Hertz, discoverer of radio waves, tested its pos- sibility and found it feasible. Nikola Tesla, celebrated inventor, who devised a system of wired power to transmit alternating electric cur- rents, now in use through- out the world, has experi- mented in the field for years. Even now he is designing an amazing wireless power plant to be erected at Ni- agara Falls. Dr. Charles Steinmetz, one of the great- est electricians the world has known, was a firm be- liever in future wireless power and suggested a method by which it might be achieved. Senator Mar- coni, father of radio com- munication, adds his expert opinion that power by radio is near. ON recently Mar- coni told the Institu- tion of Civil Engineers in London that the transmis- sion of power by electrical waves awaited only the perfection of devices for projecting the waves in. parallel beams in such a manner as to minimize dis- persion and diffusion of the energy into space. The ordinary broadcasting station projects random waves in all directions that follow outward paths like the spokes of a cartwheel. A few miles away, you could not collect power enough to run your watch. But Marconi has invented a radio reflector that concentrates the waves in one direction, bunching them all together, as between two adjacent spokes of the wheel. In his system a

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HYDROELECTRIC POWER STATION a ES a re — AL POPULAR SCIENCE MONTHLY WRAY PROJECTOR | » WITH SHORT AERIAL AND CURVED REFLECTOR Ch as a | / : X| HIGH-FREQUENCY APPARATUS STEPS UP] VOLTAGE WITH TURBO- my GENERATOR are arranged in a curved row at the back of the main number of short “aerials” broadcasting antenna, to reflect the waves it emits in a beam with parallel or, at most, slightly fan-shaped edges. Be- tween London and Canada, and else- where, this type of “beam radio” has produced strong signals for radio teleg- raphy, at a distance where ordinary sig- nals would be weak and inaudible. A “magnifying transmitter,” that hurls electric currents at millions of volts into the earth, to be recovered as power at any point on its surface, is the inven- tion of Nikola Tesla. “The transmission of power without wires is not a theory or a mere possi- bility,” this wizard of electricity told me recently. “It is a fact which I myself have demonstrated in numerous practical experiments, conducted on a large scale with a generator of 1500 kilowatts capac- ity. As long ago as 1899 I found that the current from my magnifying transmitter traverses the globe and returns to its origin with undiminished strength. This afforded evidence that there was virtually no loss in the transmission through the earth; and that by a properly organized apparatus at the sending and receiving stations, power in industrial amounts could be transmitted with an efficiency as high as ninety-nine and a half per- cent.” O TRANSMIT power through the earth, Dr. Tesla said, he plans to erect at Niagara a huge tower similar to the one he had partially completed on Long Island, N. Y., when it was de- stroyed at the outbreak of the European war. Contrary to popular opinion, neither that nor the improved structure he proposes is a radio tower. Like some gigantic pile driver, it will jar the earth, not the air, with artificial thunderbolts manufactured in its mushroomlike dome. In the sky, as well as the earth, may lie the secret of wireless power. A study of huge sparks, some of them 400 feet long, that Tesla has produced in his laboratory, has shown that in the rare- fied upper atmosphere electricity could travel with surprising ease, though at ground level it takes thousands of volts to produce.a spark a few inches long. Other experiments have shown that the levels at which such a flow of electric power could be produced are within a reasonable distance of the earth,—say 30,000 feet above sea level. This has led Hugh Pollard, a British engineer, to sug- gest monster towers reaching into the clouds and topped by captive balloons, to feed power at millions of volts into the vast conducting layer of the upper air. At other points on the earth’s surface, such as Mount McKinley with its 20,000 foot peak in Alaska, Mount Whitney in California, and Mont Blanc in France, similar towers would withdraw the power for distribution. At the poles, Pollard points out, this conducting layer of air is probably much nearer, perhaps only a mile high, because here the rotating force of the whirling earth is little felt, and does not pull the atmosphere away from the surface, as it does at the equator. A polar power plant The famous power tower at Shoreham, Long Island, designed by Nikola Tesla to transmit thousands of horsepower through the earth. It was dismantled at th¢ outbreak of the European war. The inventor now plans to construct a similar tower at Niagara Falls ZS ee Ly How radio eventually may supply our homes and industries with light, heat and power. Our artist pictures here his con- ception of a wonderful power transmission system of the future, based on present lab ratory experiments. High power beams of short radio waves, projected for long distances by means of huge refiectors, would be tapped by receiving apparatus, much as we now tap broadcast radio programs July, 1927 HIGH POWER BEAM OF EXTREMELY SHORT RADIO WAVES oe — a agp age: Oe yg On weee mae Sa es “ re eg eel aie atl might therefore feed power more easily into the aerial electric reservoir. More- over, the exploring parties of Vilhjalmur Stefansson and of Capt. Donald MacMil- lan in the Far North, and of Sir Ernest Shackleton, Roald Amundsen, and Capt. Robert F. Scott in Antarctic regions have reported that vast stores of coal, and occasionally oil, exist near the poles. There would be no lack of fuel, then, to run the plants—fuel that now lies unused simply because the cost of transporting it to civilization would be too great. OW well the theory of a low conduct- ing air level at the poles agrees with fact is likely soon to be known. Arctic explorers invariably return with accounts of strange displays of northern lights—a weirdly beautiful electric phenomenon still not fully understood, but known to have a definite connection with the elec- trified upper air. The most recent polar expeditions have collected masses of sci- entific data taken from auroral observa- tions, which may confirm the existence of such a low-hanging layer. The amazing system of wireless power proposed by Dr. Steinmetz, the exact opposite of Tesla’s “earth power,” was to girdle the earth with power from the out- side instead of from within. A broad- casting station, he said, might emit a wave of tremendous strength—millions of horsepower—that would circle the earth and return to its starting point. If the wave length were properly chosen, such a wave would have lost only a small part of its power by the time it completed its journey, and would continue its circuit many times. The broadcasting station would time its successive waves so accu- rately that the first one returned at the exact moment that a similar one was be- ing sent out. The only additional power required, then, to keep the waves going would be to make up the slight loss in transmission, as long as no power was being withdrawn. When some receiving station “tuned-in” to withdraw the wireless power, it would “leave a hole in the wave”’ that the broadcasting station would make up_by supplying an addi- tional amount. Many stations scattered over the world could feed power into the wave, each one carefully timed to emit its waves just as the main wave passed by.

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ly, 1927 easily More- almur icMil- Yrnest Capt. ; have , and poles. en, to nused ‘ing it i\duct- ; with Arctic ounts its—a nenon wn to : elec- polar of sci- serva- nce of ower exact vas to e out- road- mit a lions > the point. 1osen, small sleted ircuit ation accu- it the is be- power going ss in r was ‘iving the ole in ation addi- tered o the nit its d by. . apparatus on the July, 1927 Cai POPULAR SCIENCE MONTHLY RAY RECEIVER il LECT 21¢C LINE wm ~ ‘ont oe rn eta gine SMALL PROJECTORS ADJUSTED are) HOMES AND FACTORIES 7% TO DIRECT LOW POWER gs “Radio power” of another sort was used by Dr. Harvey C. Rentschler, like Dr. Thomas a Westinghouse __re- search engineer, to perform a feat that had baffled chem- ists for years. He demonstrated his same night that Dr. Thomas disclosed his method of trans- mitting power with- out wires. Inanew type of “radio furnace” that melts metals in a vacuum, Dr. Rentschler succeeded in obtaining the rare metal uranium in a solid mass for the first time. The device that accomplished this remarkable result and thereby inaugurated a new science— “radiochemistry ”—was designed to focus a large quantity of radio power in a small space, rather than transmit it to a dis- tance. When Dr. Rentschler threw a switch that turned on the current, radio waves from a powerful electric coil pierced the emptiness of the vacuum to generate a terrific electric current in a small capsule of impure powder con- taining uranium. ‘There ID likely, Dr. Thomas told the scientists who witnessed his demonstration of lamp-light- ing by radio. Already he can transmit power with- out wires over a short distance. With im- proved vacuum tubes and electric cir- cuits, he said, he hoped to improve his power transmission until he produced a type of wireless wave that would yield a space-annihilating beam over which huge quantities of power might be sent. Short radio waves, ten thousand times shorter than those used in broadcasting, are the means Dr. Thomas will use. His E —— ree re BEAM AT ronan RECEIVER . FOR. RADIO . POWER a “beam radio”—but a beam goal is unlike any that has ever been produced. If he can make his radio waves short enough—and powerful enough—he will focus them to a narrow, four-inch ray by means of a curved metal mirror! Then he will project his beam, like a searchlight, to its destination. Such rays would criss-cross a city, and wires would become obsolete. Each home would have its own “rod receiver,” a short copper wire, resem- bling the one Dr. Thomas was a flash, and incandes- cent metal swelled to a molten mass. When it cooled, Dr. Rentschler was the first man in the world to see what this extremely heavy metal looked like. Much like iron in its gray- ish appearance, it was far more precious than platinum. Other rare metals of like properties yielded their se- crets to Dr. Rentschler when placed in the vacuum and heated by radio waves. The new furnace is of ines- timable value to chemists, who can now watch reac- tions they could never see before—that can take place only at high temperatures, used in his demonstration, with which you could tap the power flowing through the ether just as you now listen-in to music with your radio set. The idea of reflecting radio waves with mirrors may seem a little startling, but, your own experitnce will yield the evidence in its favor. The silvered re- flector of your car’s head- light concentrates its rays in a parallel beam. Light waves and radio waves are closely related to each other, differing only in their length; the waves of light are much shorter. Could radio waves, like light, be focused? in a vacuum. With radio power in a test tube already achieved, will the next step be radio power in your home? Very Courtesy New York Electrical Society A remarkable concentration of radio power. Dr. Harvey C. Rentschler, Westinghouse research engineer, demonstrates his new type of ‘‘radio furnace’’ which melts metals in a vacuum. Powerful radio waves from the electric coil above Doctor Rentschler’s hand penetrate the adja- cent vacuum tube and generate a terrific current in the metal within In between light and radio are heat waves—of medium length. Like light waves, they too can be (Continued on page 114)

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i ee 12 POPULAR SCIENCE MONTHLY July, 1927 | N ews of the Month A whippet lost to a horse the other day, in a feature race at the first national meet of the Pacific Coast Whippet Association. Ar- royo Sloe Eyes, a California igs bred dog, beat all his canine eo : fos competitors but, matched ee against a race horse, Clock- work, lost over a 200-yard mc d course. Phato shows Ar- = royo and Clockwork racing Cross-country hiking by bal- loon is the latest sport. With all but five pounds of his weight supported by a bal- loon, a man can leap with fantastic ease over houses, trees and streams. In the illustration, a balloon jumper After the blasting. Note the size of the rocks into which the mountain was split. The dynamite had been planted in 200 holes in the rock of Berlin is seen descending from a record 600-foot jump Boo-oo-m! At the sound of the blast, a whole mountain blows up and tons of rock hurtle skyward! A New York road building company used this novel method of obtaining rock for roadbeds. The mountain was solid rock, 75 feet high, 900 feet long. Photo shows it right after blasting Great Britain is the proud possessor of the world’s biggest and fastest submarine, pictured below—the X/, just launched. A commerce raider with the speed of a destroyer, it boasts a powerful armament and has a displacement of 8600 tons Ships sighted in fogs, smoke pierced at a glance —these are the latest wonders of television in its newest form, nocto- vision, promised by John L. Paird, Scotch televi- sion pioneer. Baird is seen above with the apparatus with which he has dem- onstrated these marvels July

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1927 guty, 1927 POPULAR SCIENCE MONTHLY 13 Cross-Country Hiking by Balloon—Britain Builds Largest Submarine—Blowing Up a Mountain—Ingenious Inventions Flights in homemade gliders, or motorless airplanes, have become so popular in Ger- many that clubs have been formed, the mem- bers of which build their own machines and a hold competitions. The flyer starts at the , ee top of a hill, and, racing down the slope, . swoops into the air. By careful balancing he can take advantage of wind currents to remain in the air a surprising length of time, as the aeronaut below is demonstrating Boston gave its water supply a high pressure test the other day that reassured the city considerably in respect to the danger of fire in its tall buildings. This spectacular test was made in the Custom House Tower, and the water was forced to the height ot 500 feet—far above the roof level of the city A tragic ending to one trans- Atlantic flight attempt occurred at Langley Field, Va., when the plane that was to carry Comman- der Noel Davis to Paris crashed to earth during a test. Davis and e the his companion, Lieut. Stanton which H. Wooster, were instantly killed The when the plane buried its nose in anted the ground, as shown in the photo- rock graph below, taken from another plane a few minutes after the fatal accident. At right may be seen the mass of debris, all that was left of the forward part of the plane, including the cockpit in which they were sitting. Over- loading was blamed for the wreck This remarkable vehicle is probably the fogs, Fone smallest and oddest motorcycle in the latest world. It consists mostly of one large m in front wheel into which is built a one- octo- cylinder motor. ‘The gasoline tank is a can John located below the handlebars. The brakes elevi- are nonexistent, the driver stopping his ; seen machine when necessary by dragging his ratus feet. Remarkable speed, however, is claimed dem- for it by its inventor, William Nichols, of Massachusetts Institute of Technology arvels

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POPULAR SCIENCE MONTHLY Chief of rena A Thrilling Story of the Science of Fire Fighting By Kari W. DETZER Illustrated by H. T. Fisk Marshal Sullivan spread out his big hands in a gesture of failure. “Kel- logg,”” he _ said, “when you get the job, don’t be hard on the old man” HE fire marshal, whose name was Peter G. Sullivan, scowled at the report of his first assistant. “Just the two of °em?” he demanded. “Nobody else?” “Just the two,” the first assistant affirmed. He stood across the desk from his chief. Sullivan was a huge man, overlapping his cha:.’, with hands like mallets and a face like a sun-cured ham. The assistant, was the taller of the two, just as old, but with less meat on his bones. “I tried to talk Kellogg out of it,” he com- plained. “But you know these young Johnny-Jump-ups—no stoppin’ them! And civil service commission watchin’ us close. Was we to try a bit of fancy work to keep Kellogg from climbing over the head of old Dargan, they’d be on us like a fallin’ wall.” “Send ’em in, one at a time,” the marshal commanded. Captain Kerry Dargan, Fire Engine Company 14, strode determinedly into the bare quarters of his chief. He carried his uniform cap in his hands, and the marshal noted that the two nickel-plated bugles on its peak had been polished carefully for this occasion. He was a short, knotty veteran, this Captain Dargan; his shoulders were square, and his jaws; even the toes of his stubby, black shoes were cut straight across. “*Mornin’, Chief,’ he said. His voice rumbled across the room. “Hello, Kerry.”” The marshal pushed a cigar toward the captain of Engine 14. “Smoke?” Dargan dragged a chair nearer. “Thanks, Pete,”’ he said. “Kerry,” began the marshal, “I hear you’re goin’ up for battalion chief. I was wonderin’. How old are you now?” “Fifty-seven, Chief.” *‘How long you been captain?” “Twenty-six year, come March.” The marshal turned slowly, searching for his cuspidor; search- ing, too, for an argument to dissuade his old friend from risking July, 1927 defeat in competition with the younger man. “Examinations is kind of stiff, Kerry,” he said. “This here new civil service board . . . no sense to it or anythi . . but a fellow can’t get by no more just bein’ a good fireman.” “No,” Dargan agreed. “Ain’t like the old days in the department. But I know my stuff. Been studyin’ hydrauligg Kind of hard rememberin’ such nonse: but I’m goin’ to take a chanct. Cant break even on the book questions, Fj drown that guy out on the fire businegg stuff.” “Sure,” the marshal conceded, puttin’ out fire and writin’ about it 4 different.” OURSE it is!” boomed louder. “But that Kel logg! He’s a sufferin’ disgrace to the bugles on his hat, tryin’ for battalion chief, young as he is. Why, it ain’t ten year since I give him his first dose @ smoke. Captain already, and wantin’ to be chief! I got my stomach full o’ him!” “He’s right young,” the marshal ad mitted. “But that don’t make a lot of difference on this paper stuff. Board’ got to judge ’em fair, Kerry. If he beats you today ... well, you'll always feel bad about it. Why don’t you leave good enough alone? Go back to your company, Tll give you ten days extry leave on your vacation. You ain’t far from pension. . . “Not by the holy hydrants I won't! Take to the air for him? Why, that boy can’t wet down a roof, Pete. Ain’t got the beginnin’s of a bat chief!” The marshal sighed. He had known it would be no use. He spoke hurriedly, knowing also the extravagances of Captain Kerry Dargan’s temper. “Up to you, Kerry, up to you! I stand in nobody’s way, and you know me long enough to be sure of it. Shake, Kerry. Best luck. But, Kerry . . . hydrau- lics, it’s a tough proposition to tackle!” Captain Dargan tramped out of the room. Thirty seconds later the trim, young, confident figure of Captain John Kellogg advanced to the marshal’s desk. He lifted his right hand sharply to a proper salute that betokened military training. “Captain Kellogg reports, sir.”” he said, and stood at ease while the marshal studied him. He was not more than thirty-two or three. His eyes, which were light gray, did not falter as they met the chief’s. . ‘Goin’ up for battalion chief, Kellogg?” the marshal asked. He did not offer this captain a cigar. “Well, there’s been 8 vacancy a long time in stockyards battalion, you know. Near two years. Captain Dargan’s been handlin’ the job of actin’ chief pretty good, don’t you think?” ~ “Yes, sir.’ Dargan’s voige ARGAN’S a good fireman. Knows his stuff. But he ain’t got book learnin’! Now, Captain, I don’t say it ain't right and proper for you to go up ag’in’ him. I don’t know wh else you can do. But . . . don’t you see, Kellogg?” “See what, sir?” Again the marshal turned and searched his cuspidor. “Course you'll beat him,” he said confidentially. “‘He ain’ comfortable with a fountain pen. And hydraulics is hard for old man.” “T have some trouble with hydraulics, too, sir.” “Listen, Kellogg. If you don’t go up for promotion in yo battalion, and nobody else does, it still leaves a vacancy. Ol Dargan will hold it, actin’ chief. Then after a bit, three or fo years, he’ll retire on pension. And you'll have the job to yo self.”’ “The vacancy is there now, sir. Best man ought to get it.” “Married, Kellogg?” Jul

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July, 1927 > younger 't like the it I know ydraulieg, nonse t. Can | tions, Ty > business ad, “o rout it n’s Voice that Kel. ‘e to the battalion ain’t ten t dose @ vantin’ to |o” him!” irshal ad- e a lot of Board’s f he beats ways feel eave good company, ry leave far from | I won't! that boy Ain’t got known it hurriedly, ances of er. . you! I know me Shake, . hydrau. » tackle!” y seconds n Kellogg id sharply d at ease hirty-two er as they hal asked. ’s been a ow. Near of actin’ it he ain’t ay it ain't now what or “He ain’ ard for yn in yo incy. Old ‘ee or fo b to you get it.” POPULAR SCIENCE MONTHLY 15 Kellogg lay on the hot floor .. . “Not yet, sir. Can’t afford to. Battalion chief makes more money. Maybe then... ” * All right!’ Marshal Sullivan spread out his big hands in a gesture of failure. He had known this would be no use also. “T'll put nothin’ in your way. But Kellogg . . . when you get the job, don’t go bein’ hard on the old man. He’s a good fire- man. Give all his life to the business. Go easy on him.” He paused, scratching his chin. “Lots o’ young officers with old men under em... ” Again he paused, and this time indicated that the interview was over. IVE hours later the first assistant marshal looked up thank- fully at the clock in the examining board room. Before him at two tables sat the two candidates for the office of battalion chief in the stockyards district. Dargan had finished his ex- amination paper with twenty minutes to spare. Young Kellogg still added sums, multiplied, strove with intricate fractions. There had been five problems in hydraulics. “Time’s up,” the assistant marshal said. Two other members of the board put down their magazines and strolled over from the windows. They folded the completed examination papers and stuffed them into manila envelopes, which they sealed with wax. Captain Kellogg turned to his elderly rival. “Hard one, wasn’t it?” he said. He tried to be casual. “Yeh,” Dargan answered gruffly. “’Rithmetic ain’t for grown-ups.” ‘I mean the fire problems.” “Oh, them? No... easy.” Captain Kellogg frowned. “I didn’t think so,” he said. “That one on Schwart’s beef house ... here . . . fighting a fire in the cellar of Schwart’s beef house, if you were chief of battalion and first in. It nearly got me.” “That’s easy,” Dargan disputed. “All you can do in that old trap is go in and drown it, ’lest it gits too hot. Then yank your companies out, far enough so’s the walls won’t hit ’em.” Kellogg drew a comb from his pocket and ran it through his hair. Dargan bit off a mouthful of tobacco. “T’ve always worried about that beef house,” Kellogg con- fessed. “Thought about it a lot . . . hard place to fight fire. How’d you say you’d distribute first alarm companies?” Captain Dargan glanced at the younger officer scornfully. This youngster might understand the books, but he didn’t know the fire business. ““Nach-eral. way,’ he said. “You drive in from the south, don’t you? Beef house backs up on the river. Good enough. ammonia was knocking him out. . . how could old Dargan stand it? He heard a warning shout and saw Dargan rise to his knees. An immense wrench of timbers thundered above the noise of the fire. ‘*‘ Cut off!’ Dargan cried If the fire’s in the basement, hit the two main south doors. First two companies . . . send ’em in there. First truck company to roof and up the sides to ventilate.” “Ventilate right away?” “Sure... ammonia in there... ventilate right away. Third company in to foot of elevator shaft, passin’ first two companies. There’s where your fire will be. Fourth company follow ’em. Then have your truck take a second line off pumper, to roof. Use your squad for whatever else there is. but have smoke helmets handy. Don’t give squad a line; have ’em ready with smoke helmets. That’s how I done it.” “T brought them in from the north,”’ Kellogg said thought- fully. “North?” Dargan spat. “Yeh, suppose you would. That’s the trouble with young fellers. Climb over all them fences to get round behind it. You’d have plenty of water, north, on second alarm. Two fire tugs.” “The examination says it’s a windy day,” Kellogg added stubbornly. ‘We wouldn’t have the smoke in our faces, north side.”’ He was snapping a rubber band around his note paper. Dargan looked at him disdainfully. “Leave the best man win,” he grumbled, and didn’t see Kellogg’s outstretched hand. “You won’t hear from these for a couple of weeks,” the first assistant explained. “Got to have regular meeting of board first, before we break the seals. Goodbye, Dargan. Goodbye, Kellogg.”’ APTAIN JOHN KELLOGG discussed the whole examina- tion that night with his crew on Engine 26. It was a warm evening, early in August. The broad front doors of the company quarters stood open to a noisy street. In the apparatus room young Jim Burton sat on duty before the busy alarm instrument board. Outside, where it was cooler, white-haired Hennessey, with a face like a monk’s and the vocabulary of a wharf rat; McSweeney, who had served eighteen years in the same com- pany; Stein, whose brother was an organizer of the garment workers’ union; and Driver Johann Carlson tipped back their chairs against the freshly sprinkled front of the building and heard their captain approvingly. They knew he would make a good battalion chief. “I’m not sure of that one question,” he was saying. “I often wonder what I'd do if that old trap did catch fire.” Five pairs of eyes picked out the tall, black silhouette of Schwart’s beef house against the smoky evening sky line. “Was I havin’ my say,’ Hennessey replied, “I'd leave the

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Engine 26 racketed into the ‘ street, its bell chattering, motor : 937 grumbling. Driver Carlson’s ed wife was waving goodbye from the driveway. Pedestrians halted to watch the brief, glam- orous passage of crimson steel blasted shack burn. Them walls could fall a hundred feet.” ** Aye,’” McSweeney agreed. “I'd have no close dealin’s with it. I'd get off on top o’ the box cars at the sidin’, and siamese my lines two-and-two, and I'd hit her from there. Might be safe that far off. Ammonie . . . she’s poor stuff when she gets to runnin’ free and easy.” In the engine house the joker alarm set up an excited rattle. Jim Burton was on his feet before the polished instruments. “That’s us!”’ he said, and the crew leaped. It was a roof fire, in a crowded tenement district, a dusty, smoky little blaze that hung on stubbornly. Captain Kellogg fought it without enthusiasm, subdued it at length, and re- turned silently to his quarters, still mulling over the questions of the day’s examination. The problems in hydraulics had been difficult. That had not surprised him. He had told the marshal that hydraulics bothered him. But that second one, for instance. He remembered it per- fectly, even to the blurred carbon of the typewriter. “Fire is discovered on the twenty-second floor of the Columbia building,” it,had begun, “‘two hundred and seventy-two feet above the street. You command battalion, Your first engine lays eight sections of two-and-a-half-inch hose. Hydrant pres- sure is ninety pounds. The pumper uses a hard suction. It is a new model thousand-gallon machine. You instruct your captain to hook on a half-inch tip. What is your nozzle pressure per square inch on the twenty-second floor?” Captain Kellogg climbed dejectedly from the engine and set the crew to wiping down the wheels. It worried him, that one problem. He had figured the thing out twice since coming back from the board room, each time with a different result. 7 A’ LEAST old Dargan didn’t get it,” he assured himself savagely. “Probably missed all the hydraulics.’’ But what consolation was there in that? Twice and a third time that hot week he saw Acting Chief Dargan at insignificant fires. The old man had grown shorter, it seemed to Kellogg, squarer of build, harder jawed. He scowled as he worked. On Saturday night Kellogg led his company into the front doors of a great oil-soaked garage. The wind was at his back . - - he always made sure of that; he had no liking for drafts puffing flame and smoke into his eyes. Dargan rattled up in his own apparatus. “Lead off!”’ he was screaming. “Joe, pull a two-bagger! A POPULAR SCIENCE MONTHLY July, 1927 two-bagger, Joe! Four more pumps . . . what you doin’, 26? In at it! Don’t go blockin’ the door!”’ He led his own crew in past Kellogg’s handful of men, and with spiteful vehemence attacked the flame. In ten minutes, even before the second alarm reinforcements had their hose laid, Acting Chief Dargan’s battalion had beaten the fire. “Get up close so’s you can hit her next time,” he coun. seled Captain Kellogg as the two companies were break. ing their hose sections and rolling them into wet fifty. foot lengths. ‘‘That’s what the fire business is for. Get in and knock it out!” “Lots of gasoline,” Kel. logg answered sharply. “I got a good crew.” ““Savin’ ’em for pensions, mebbe,’’ Dargan countered, and gave the younger officer his broad, square back. Sunday passed without an alarm in the stockyards district, a gloomy day with spongy clouds and occasional sprinkles of rain, The fumes of rendering vats and the odor of cattle pens pressed down breathlessly upon the district. Sunday night the air lightened. A fresh country wind drifted down from the north and Captain Kellogg went early to bed, leaving McSweeney on watch at the alarm stand. Hennessey and Jim Burton were playing checkers at the rear of the appa ratus room. Stein had draped his meager body over the rough contours of hose on the box of the pumper, where he claimed it was cooler, and slept intermittently. Johann Carlson stood in the dark on the front driveway, talking in an undertone to his wife. Kellogg, tired though he was, could not sleep. There was still the examination to plague him. The board had not yet opened the papers. But he was certain now that he had missed that second problem in hydraulics; missed it by twenty pounds. Forgot to allow for friction through eight sections of hose, Dargan might have stubbed his toes on that one too; very likely he had. But Dargan couldn’t miss the others. That’s where being a captain twenty-six years counted for something. ‘Take that seventh question, for instance, about a fire in a china store, 7 OU are in with first company at a fire in a china store,” it had said. ‘*The blaze is small, in a basement stairway halfway back. The room is long, with a door on street and alley.” He’d answered that right, he was willing to swear. He had advised the spray tip on the hose nozzle. Heavy stream would smash the china. Smaller cities would have used chemicals in that situation. Big towns depend more on water, and in a china store, spray. So much for that. But then came the beef house. Dargan said he was wrong there. Dargan was a good practical fire fighter. Well, he still thought that if the situation ever arose, he’d go in from the north. He hated smoke in his face. . . . He turned restlessly on his hot pillow. At the same moment he heard the steel teeth of the joker alarm bite out a message in the apparatus room below. Five sharp notes . . . pause... five more... pause... a third five. In the code of the department, the instrument was shouting “ Alarm of fire!’ Kellogg sat up quickly, flinging back the sheet. Once more the joker was snapping. Three . . . two . . . two. Call for Ladder Truck 12. Truck 12’s station was only half a mile across the district. Sometimes Engine 26 followed Truck 12 on a joker alarm Sometimes Engine 14 followed. Depended on location of the fire. Kellogg swung his feet over the edge of his cot. Like all firemen he wore his socks abed. His toes instinctively found their way into the tops of his bunkers, standing ready at the bedside. Even before the joker set up its next impatient call, Captain Kellogg’s feet were pushing down the wide mouths d the rubber boots. He stood up sharply, listening, dragging the bunkers upward with his left hand, his right pushing his blu shirt down into them. He snapped the iron clasp at the waist. “Two... six.... the joker sputtered. Kellogg wrapped an arm about the brass pole that thrust up ward beside his bed through a hole in the floor. Ten seconds tf had taken him to dress. He kicked away the canvas screel covering the hole and, hugging the pole with his right arm, she down to the apparatus room. (Continued on page 124) Jul; ha th be! pre dai F

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July, 1937 loin’, 26? men, and minutes, hose laid, S$ you can he coun. gg as the re break. tions and wet fifty. at’s what for. Get ‘i e,” Kel. rply. “I pensions, ountered, ger officer ick. district, a »s of rain. ns pressed nd drifted y to bed, Lennessey the appa- the rough claimed it 1 stood in one to his e was still et opened issed that 7 pounds, ; of hose, rery likely it’s where ng. Take \ina store, ” na store, , stairway treet and . He had am would emicals in im a china eef house. | practical ‘Ver arose, e moment nessage in ause ... ment was ging back . two ation was er alarm on of the Like all ely found dy at the tient call, nouths of gging the z his blue > waist. thrust up seconds it ‘as screel arm, she r page 124) July, 1927 POPULAR SCIENCE MONTHLY The" ‘horseless carria, is exhibited for 4 first time. Drawn for “Whirling W beels’’ by B. J. _tacanell Do you Remember When ~ the Automobile was new and people shouted “Get a Horse!’’? Those were the days that marked the beginning of one of the most thrilling and romantic struggles that America has known—the race of iriventive gen- iuses to produce the marvelous machine that we now call the Automobile. EDMUND M.LITTELL Author of ''Midge’’and ''Fire-Shy”’ has written the story of the Age of the Autorhobile in a masterful novel that has caught the full flavor and drama of this exciting period. If you know the thrill of skimming over the highway, cradled in comfort behind a smooth humming motor, if you recognize the glamor of industrial progress, if you respond to the heroism of pioneers— men of vision who dared face poverty, discouragement and ridicule for an ideal— do not miss EDMUND M. LITTELL ‘Whirling Wheels” the remarkable serial which begins in our next issue. It is a vigorous, sweeping story of the struggles and triumphs, loves and hates of real flesh- and-blood people. But more than that it traces accurately and with infinite detail the growth of the Automobile from an idea to the tremendous industry that we know today. Pop pular Science FOR AUGUST— ON YOUR NEWSSTAND JULY 2nd

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18 How Floods Challenge Science Engineers Propose Gigantic New System of Levees in “‘Fight to Finish’’ to End Musstssippit Disasters ESTRUCTION, misery, death— and a gigantic challenge to the engineering genius of man! If there is one outstanding fact that has grown on the American people, watching the Mississippi River let loose its most devastating flood, it is this: Science, achieving wonderful conquests of the air, the earth and the elements, has yet to leash the waters that rise in their might and break their bounds. Helplessly, men see the flood rear its swollen crest. In futile desperation they fight back. By the thou- sands they swarm the levees, piling sandbags to reinforce the bar- riers. And yet the mighty waters surge on. That is the Missis- sippi flood at its worst —$500,000,000 in dam- age perhaps. As this is written, there is a nation-wide demand for science to find a remedy. Thirteen Mississippi floods in less than half a century! Every- where Government of- ficials, engineers and scientists are saying there must be no more. But what is to be done, and how? If, one day late last April, you could have stood in Memphis, Tennessee. watching POPULAR SCIENCE MONTHLY By Epvcar C. WHEELER the crest of the flood sweep slowly by, you would have realized something of its overwhelming power. Two million cubic feet of water flowing past every second— more than a billion gallons every twenty- four hours—the volume of ten Niagaras in a single stream! And if, a few days later, you had been a few miles from Vicksburg, where one of Typical scene of the havoc wrought by the Mississippi flood—an Arkansas city inundated after the water burst through a crevasse. Encampments of refugees are seen on the levee July, 1927 An irresistible force rushing to the sea—the mad torrent of the Mississippi thundering through the gap in the Poydras levee, below New Orleans. This gap was made by dynamite blasts, to divert the flood and save the city the strongest of the river levees gave way, you would have seen the Mississippi then as an immense, overburdened storm sewer, fed by 240 tributaries with the drainage of two thirds of the nation’s territory. In that one stream you would have witnessed the joining of many distant waters, drained from an area of mor than a million and a quarter square miles, brought down from as far west as the Rockies, as far east as the Alleghanies, and as far north as the Canadian border! The Missouri from Mon. tana and the Dakotas; the Platte from Wy- oming and Nebraska; the Arkansas from Col- orado, Kansas and Ok- lahoma; the Ohio from Pennsylvania; the IL linois from the regionof Chicago; the Des Moines, Wabash, Ten- nessee, Cumberland— these and hundreds of other lesser rivers and streams you would have found mingled there in devastating flood tide. Small wonder that em- bankments of earth and sand should fail to bridle them all! \ F ET experts believe that final mastery not only is_ possible, but practical. Plans are already under way for a scientific survey whi pre: cer! pro of pro van wat in ¢ of | ina Ass alor syst ers Bur obs pers sno’ ords tion prec

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July, 197 shing to the nt of the 1g through dras levee, ‘his gap was blasts, to ave the city Ce gave way, sippi then od storm with the - nation’s yuld have y distant of mor are miles, st as the leghanies, rth as the der! The mm Mon- Dakotas; rom Wy- Nebraska; from Col- s and Ok- Yhio from ; the IL > regionof -he Des ash, Ten- erland— ndreds of ivers and ould have 1 there in ood tide. that em- earth and fail to ll! ts believe mastery possible, Plans ider way c survey July, 1927 of the flood regions. The chief of Army engineers, Maj. Gen. Edgar Jadwin, after a rsonal inspection, has predicted that the pres- ent Mississippi levees will be heightened at least five feet. Others have proposed rebuild- ing the entire 2,000- mile levee system, mak- ing it stronger, higher, and uniform in struc- ture. At a cost repre- senting one half the losses of the latest flood, we are told, the levees could be built strong enough to assure safety for ali time. ‘PDEFORE long we B may see great walls of concrete rising to a height of fifty feet or more and extending for thousands of miles on both sides of the river and its important trib- utaries. It is not be- yond the range of vision to foresee vast dredging operations that will deepen the river channels, make more room for flood waters, and open their far-reaching courses to POPULAR SCIENCE MONTHLY MELTING SNOWS SwWELt RIVERS a gle navigation. Then would the wide- flung network of rivers, now a menacing flood source, be converted into a great inland system of commercial waterways, with an outlet, perhaps, through the Illinois River into the Great Lakes; thence by way of the projected St. Lawrence waterway into the Atlantic Ocean. If the flood control legislation now planned is enacted, this will involve undertakings calling for the expenditure of hundreds of millions of dollars, directly affecting forty states. New sources of hydro-electric power will inevitably be created. _These are _ possibilities which eventually may grow out of tragic loss. For the present, the immediate con- cern is to safeguard life and property. In the knowledge of floods, their origin and progress, science has ad- vanced far. Today the coming of flood waters can be forecast weeks in advance, and inhabitants of threatened areas warned in ample time to seek safety. Assigned to definite sections along the important river systems are trained forecast- ers of the U. S. Weather Bureau. Each makes daily observations of rainfall, tem- perature and melting of snow. Considering these rec- ords in relation to the slope of the region and the condi- tion of the soil, he is able to predict very accurately the The development of the Mississippi deluge may be traced in the numbers above. The first warning came in August, 1926, with rains in Kansas. The Mississippi and its tributaries drain two thirds of the United States, producing at flood crest the volume of ten Niagaras! approach of danzerously high water. From records of previous floods, he knows the time it takes for high water to flow from tributaries into the main stream and for the flood crest to pass from one city to the next. Thus, for example, the time required for high waters to pass Pittsburgh, Pa., down the Ohio and Mississippi to New Orleans is twenty-two days. From Pittsburgh to Cincinnati, O., it takes five days; from Cincinnati to Cairo, IIl., six days; from Cairo to Vicks- ‘‘Make Mississippi a Vast Lake,’’ Is Hoover’s Solution “TE. IS essential that time and money be not wasted in the consideration of visionary measures of relief. The feasible means of guarding against future disasters in the lower Mississippi is the adequate widening and raising of the levees on the main river and its back- water tributaries, and the extensions of bank protection, with special treatment in special situations in the lower valley. “The most practicable and economical reservoir is that which may be formed by high and strong levees in the most strategic location, the valley of the river itself, creating in effect a self-evacuating lake extending for 1,000 miles from Cairo to the Gulf.” HERPERT HOOVER Secretary of Commerce 19 burg, Miss., seven days; and from Vicksburg to New Orleans, four days. The movement of flood water, of course, is slower than that of the river current. In the: latest flood it was con- siderably slower than ordinary because of the extremely high waters. DVANCE warn- ings of the Missis- sippi’s greatest flood unquestionably saved hundreds of lives. In- deed, the first grim warning of the catas- trophe came as long ago as August of last year, when heavy rains raised the waters of rivers in Kansas and Oklahoma. These were followed in October by damaging floods in the Arkansas and Neosho Rivers in the Kansas prairie region. Then the rains drifted east- ward, over Missouri, Illinois, Ohio, Tennes- s see, Kentucky, and the : Cumberland valley. Since all this water was at a season when rivers of the Mississippi sys- tem should normally have been at their low- est levels, official ob- servers realized then that trouble was brew- ing. “We knew then,” says H. C. Franken- field, head of the Weather Bureau division of rivers and floods, “that if the rains of the coming winter and spring were much above normal, we were going to have a big flood. But, of course, we could not predict the volume of the torrent.” His worst fears were realized. Late in December more rains swept Tennessee and Kentucky. The Cumberland and Tennessee rivers rose tc flood stage. All high water records in the Cumberland were broken. In January the winter rains became more widespread, and the Ohio River flooded. By March every one of the Mississippi's tributaries was dangerously swollen. Melting snows in the north and in the moun- tains far to the west and east added to the rising waters. As the deluge gathered, Uncle Sam’s watchful ob- servers sent daily reports and warnings down the line. Along the levees of the lower river engineers organized workers and materials to re- sist the advancing enemy. Sandbags and other rein- forcements were held in readiness. At crucial -points levees’ were strengthened. Inhabitants were forewarned. Then, in April, the angry (Continued on page 111) PITTSBURGH

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POPULAR SCIENCE MONTHLY Loading the painting, in a huge crate, on the trailer that carried it to Havre The Largest Package Aver Shipped Removal, crating and transportation of five-ton war painting from France to America a triumph of mechanics Spindles which were used, up- ended, to roll up the canvas from Paris, France, to this country, a five- ton painting recently taxed the ingenuity of mechanics and engineerscharged with its transport—for it was ie said to be the largest pack- dee age ever shipped to the fan ry United States! #5 The “Pantheon de la Guerre,”’ or “memorial of the war,” as the monster canvas is named, is a I: AN eventful trip in a packing case reinforced with iron rods and rainproofed with zinc, raising the weight to ten tons. A ventilating system guarded it against heat. As there was no truck in Paris big enough to carry it, a special truck and trailer were built. The precious load ar- rived at the port of Le Havre without mis- hap, though in one village en route a sharp turn made it necessary to re- move street and shop signs before the truck could pass! Then it de- veloped that neither the dock cranes nor the special cranes of the liner Paris, a panorama history of the World War. It is four ‘hundred feet long, fifty feet high and contains six thousand portraits. Until recently it occupied an entire building in Paris. When it was decided to bring it to America, unusual difficulties were met with and overcome. To remove the stupendous canvas from the wall without tearing, it was sus- pended like a shower curtain from sliding hooks on a metal bar. At one end a spindle the exact height of the painting was raised between concrete towers, and the canvas rolled up on it. Forty-five workmen were required for this job. Carefully the roll was lowered and crated Velvety cloth was fed into the roll to protect the canvas face from abrasion Floating derricks had to be brought into action to swing the case on the deck of the Paris Femoving the painting from its Paris home: A runway had to be built around the top of the building to aid in rolling up the canvas on which it was to sail, could lift it! A huge floating crane finally swung it aboard, and it made the ocean trip above deck—there was no way of getting it into the hold. The painting will be exhibited in cities all over the United States. Its value if incalculable. Two French artists, Pier Carrier-Belleuse and Auguste-Francoi Gorguet, with eighteen helpers, worked on it every day during the war, recording each event as it occurred. When the Armistice was declared, it was complete live whe the can: by 1 «whe

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July, ¥ mading the inting, in huge crate, | the trailer at carried to Havre ed ris home: he top of ne canvas lift it! A swung it rip above ng it into 1 in cities ; value i ts, Pierre -Francois , worked recording Vhen the complete July, 1927 T onned Food POPULAR SCIENCE MONTHLY 21 and Your H ealth New Discoveries about V'ittamins Science Has Used to Make Your Meals Good for You done her own cooking and “ put up” fruit and vegetables every year. They were good enough for her and her family, but since she moved into a small city apartment to be near her married daughter, Grandma has had to eat “canned stuff.” “They taste good,” she said, “but it seems like the old way must be best. There can’t be any life left in the food.” So the family took Grandma Jones on a personally conducted tour through an up-to-date cannery. She saw and heard things about high grade canning methods that surprised her. She came away satis- fed that her imagination—not actual conditions—had made: her think un- favorably of canned food. Almost at a glance, she saw automatic machinery in a spotless light-flooded room, handling tons of fresh peas with all the care she would have given a quart of them. She saw how orderly the process went on. Seven washings, endless inspection, con- stant supervision! In one line, peas issued from a washer through which ran a constant stream of fresh water. They passed on through a grader which sorted them into sizes—on through scalding water which left them bright, fresh and clean—over belts where deft fingers removed all that were not perfect— then to automatic filling machines, ready for the cans, N ANOTHER line she saw the bright, new empty cans, glistening in the light, emerge from a bath of boiling water and live steam. They moved to meet the freshly washed peas at the filling machines where just the right amount of hot juice was added to the peas in each can. The cans were quickly sealed by machinery, then moved to giant retorts or cookers, ‘where live steam carried Fe: fifty years, Grandma Jones has By Tuomas M. Jounson the cooking to exactly the proper stage. “We pour in the hot juice before they are hermetically sealed, to reduce the oxygen to a minimum,” the guide ex- plained. “Then the heating in the retorts takes up the rest. The peas are cooked, as nearly as possible, without air. “But how about these vitamins, young man?” Grandma Jones asked. “Do you mean to tell me heating those peas so long doesn’t kill the value of the food?” “We're sure it doesn’t,” replied the guide. “We've had scientists checking up on that very thing. When you used to cook your vege- tables before you canned them, in an Prof. W. H. Eddy of Teachers College, Columbia University, the only scientist who claims to have seen the “‘chemical ghosts” called vitamins. Here in his laboratory he believes he has isolated the vitamin of yeast uncovered kettle over your kitchen range, you were killing vitamins. They can’t stand being cooked in the presence of air. It’s the oxidation you have to watch for, and that is what we avoid.”’ “What?” asked Grandma, incredulous. “Do you mean to say that canned foods are better for me than the things I cook over my own stove?” " ELL, there are more vitamins in many canned foods than in home prepared,” the guide explained, “and food chemists believe a certain amount of vitamins are absolutely essential for growth and health. You must have fats, carbohydrates and protein, but the vi- tamin is the spark that sets off the energy they provide. -Without the vitamin, the other elements are useless to the body. Except for this vitamin advantage in canned foods, there is really no difference between canned foods and fresh foods cooked in the home. Both are fresh to begin with—and both are cooked before they are eaten. “Besides,” the guide went on, “the fruits and vegetables used by canners are grown from specially selected varieties, that are usually better for canning than the ones shipped fresh. Added to that, there’s no chance for deterioration between the time of pick- ing and canning. Often ‘fresh peas’ have been on the market from two to four days before they reach your kitchen. “We canners don’t dis- courage home cooking,” he continued, “but we do say that under our carefully supervised conditions, we produce as good food as you can prepare yourselves. Americans eat more canned foods than any other people on earth, and the more two- by-four kitchenettes there are, the more cans are opened throughout this broad land.”

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POPULAR SCIENCE MONTHLY Left: canning plant sani- tary sealing machines seal the cans hermeti- cally at the rate of 80 to 120 cans a minute Below: Delivered to the cannery, aspara- gus goes to the spot- less sorting table where it is graded by hand according to col- or, quality and size Photon Courtesy California Packing Corporation That fitted Grandma Jones’s case exactly, so she sat down on a packing case full of cans of peas to listen while the young man told her more. ‘Ever since canning was discovered through the offer of a prize by Napo- leon Bonaparte’ more than a hundred years ago, people have thought the same thing you do, madam,” he said. “They couldn’t see how canned goods could compare with the home-cooked variety. But lately the canners have called in some of the ablest food chemists to help them. A lot of experiments have been made, mainly with white rats, and they have proved numerous facts about canned foods, particularly with reference to their vitamin content.” HEN he quoted what Dr. E. F. Kohman, research chem- ist of the National Canners’ Asso- ciation, has to say about vitamin C, the enemy of scurvy, which has been found most susceptible to heat and oxidation: “*There is now considerable evidence that commercially In the modern automatically capand July, 19 of them, and feed them a diet withoy any vitamin C. Feed those in another cage canned cabbage, and those in g third, home-cooked cabbage. The ray in the first cage will develop scurvy. The ones in the other cages will not devel} scurvy. But it will take five times gg much home-cooked cabbage to k away symptoms of the disease as it doe canned. The canned food has mor vitamin C. “ OW of course,” he hastened ty add, “it doesn’t follow that people must eat canned food to prevent scurvy. Cooked food will do it, but not so well as canned cabbage, peas, spinach or cabbage slaw. We are always finding out something new about canned goods. Prof. Walter H. Eddy, of Teachers College, Columbia Univer. sity, one of the foremost vitamin authorities, says that the ‘raw food’ fad can be overdone. “Chemists are continually making investigations to improve our meth. ods. Recently they found that by lining our wooden brine tanks with tin plates, we would reduce spoilage by bacteria. They are making impor. tant researches in this fascinating field of food chemistry. What are vitamins like? Is there a vita. min therapy? Can disease be cured by applying vitamins to diet? These are questions that are puzzling investigators. “Dr. E. V. McCollum of Johns Hopkins University pre. dicted recently that when we order dinner in the restaurant of the future we will order some. thing like this: protein, eight ounces; carbohydrates, three ounces; fats, mineral and oils, one ounce; but all will be well gar. nished with ‘vitamin saucé,’ Even that highly scientific com- bination of concentrated food elements would be useless with- canned foods are richer in vitamin C than the same foodstuffs home- cooked. Certain conditions in the sterilizing process that canned foods receive, and that do not obtain in home cooking, are ac- tually beneficial in preserving this vi- timin. Also, in the case of some products purchased raw on the market, the time which elapses between harvesting and cooking is considerably greater than that occurring in canned foods, and there is evidence that raw foods lose vitamin C in storage. *“**Cabbage canned and processed for thirty minutes at temperatures ranging from 212° to 260° F. had practically the same vitamin content, and this was four to five times as high as cabbage pur- chased raw on the market and home- cooked. Commercially canned spinach was also found richer in vitamin C by several times than home-cooked spinach, and there was no significant difference when the regular commercial process of seventy minutes was extended to 120 minutes.’” RANDMA JONES was slowly hav- ing her mind changed, but she wouldn’t give up without a struggle. “Now, young man,” she objected, lishment. Filling cans with asparagus in an up-to-date canning estab- Only a few hours elapse from the time the as- paragus is cut in the fields until it reaches the canning tables. This assures fresh food tothe consumers of canned goods “T’ve read somewhere about these vi- tamins, that you can’t see them with a microscope. How does a chemist know whether they’re in canned food or home- cooked food, for that matter?” *““That’s where the white rats come in.” the young man replied. “Take a cage out the vitamin to act as the electric spark and make its energy of use to the body. “The millennium of the food chemist, according to Dr. Eddy, will come when we know the exact food requirements of the human being of every age and occupation, and the exact contributions made to these requirements by available foodstuffs. “It seems,” the young man con tinued, “‘as if more and more depended on proper appli- (Continued on page 118) After the cans are sealed, they pass to these huge cooking retorts, where live steam carries the cooking to exactly the proper stage, without destroying any of the beneficial vitamins I I

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July, 199 tL without 1 another ose in g The rats rvy. The t develop times ag to keep as it does las more tened to ow that > prevent , but not » Spinach 'S finding , Canned Eddy, of , Univer. vitamin aw food’ 7 making ur meth. that by nks with | spoilage 1g impor. scinati What a > a Vita sease be umins to ons that rs. lium of sity pre. vhen we urant of er some- in, eight . three oils, one well gar- saucé,’ ific com- ed food ss with- t as the ake its y. the food ir. Eddy, now the > human ion, and to these stuffs. an con- lepended page 112) ries July, 1927 tock Cars Tested in Real Races Everyday Automobiles, Picked at Random from the Factories, Vie for Supremacy on Speedway POPULAR SCIENCE MONTHLY nt , = _ An eight-cylinder stock car hitting eighty miles an hour on a banked turn at the Culver City Speedway, Calif., during a recent two-hour test run. This car was partially stripped. All future tests will require complete equipment By JOSEPH S. EDGERTON FASCINATING new spectacle, and one that gives promise of definite scientific value in the development of better motor ears, comes to America’s speedways this summer. In place of highly specialized racing cars that only expert pilots can manage, we shall see everyday pleasure ears, picked at random from the stock of automobile factories, flash along the track in thrilling tests of speed and endur- ance. Well-groomed sedans and coupés, exactly like those which you and I drive through the streets, but with veteran racing drivers at the wheel, will be called upon to give their best in the stern com- petition of the track. At this writing an mportant series of racing events for actual stock cars has been arranged for. the coming weeks under the supervision of a national contest board, and sanctioned by the American Automobile Association. By the time you read this article the first of these events—a seventy-five-mile Eastern stock car championship race scheduled for the Atlantic City Speedway —probably will have been run, On the incomplete entry list were various makes, including Studebaker, Essex, Paige, Chrysler, Stutz, Auburn and Whippet, while among their pilots were such old-time racing drivers as Harry Hartz, Fred Comer, Zeke Meyer, Gil Anderson, L. L. Corum, Tom Rooney and Wade Morton. Entries were limited to standard stock models of 300 cubic-inch engine displacement or less. _ This initial event, for a stock car trophy and cash prizes, was expected to set the standard for subsequent races of the sea- son—one at the Rockingham Speedway, Salem, N. H., scheduled for July 4; others at the Indianapolis Speedway and the Washington Baltimore Speedway at Laur- el, Md. In addition, it has been an- “nounced that a $500 challenge trophy, to be contested for by strictly stock closed cars on the Indianapolis Speedway, has been offered by Samuel Stevens, banker and automobile enthusiast of Rome, N. Y. The Stevens Trophy will go to the first car establishing an average of sixty miles an hour for twenty-four hours. So, for the first time in history, racing will give the auto owner a reliable meas- Above: A stock closed car of well-known make refueling at the pits during official speed test on the Culver City track. Left: championship racer, driving ure of the merits of his car in competi- tion with others he meets on the road, under absolutely fair conditions. Early in the history of automobile contests, so- called “stock car’’ races came into dis- repute, for the reason that most of the entries were altered for the races into special speed machines. In this year’s events, we are assured, no alterations will be tolerated. The races are confined strictly to factory cars just as they are sold to the customer, without change of gear ratios, gasoline feed sys- tems, ignition or timing equipment, or the stripping of the chassis in any particular. Indeed, automobile manufacturers who once shied at “ stock car” races now are wel- coming an absolutely fair test of their cars. SSURANCE of such fairness they find in the personnel of the national contest board, which includes such names as Capt. E. V. Rickenbacker, former rac- ing driver and war ace; Tommy Milton, retired champion; Thomas J. Little, chief engineer of the Marmon Motor Company, and T. E. Myers, manager of the Indianapolis Speedway. Moreover, the rigid rules of entry bar the chance of unfair advan- tage. The contest board exercises the right to pick every competing car at random from the manu- facturer’s stock, and to supervise it un- til the race. Each car must carry its complete equipment and accessories. The only allowable “tinkering” will be grind- ing valves, honing cylinders, relieving piston and bearing clearances, and ad- justing moving parts. Experts declare that the centests not only will permit the public to check the claims of performance made by manufac- turers and dealers, but will bring valuable improvements in automobile design. Gruelling racing conditions will reveal weaknesses in present fueling systems, steering mechanisms, cooling devices, brakes and motors, and also will stimulate engineering competition.

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POPULAR SCIENCE MONTHLY A veritable bridge on stilts is this lofty arched viaduct on the Rbhaetian railroad, which traverses the Alps Mountains in Switzerland WO spans of startling magni- tude, one on each coast, are soon to usher in the “new era of magnificently great bridges.” After a generation of planning, definite steps are under way to bridge San Fran- cisco’s Golden Gate with a single span of 4,000 feet. On the east coast, construc- tion will start this summer on a gigantic suspension span over the historic Hudson, from New York City to New Jersey. Its single span of 3500 feet will be double the greatest so far achieved—two thirds of a mile, or almost fourteen city blocks from tower to tower! As this is written contracts are being arranged for the erection of the first of two 650-foot towers to support the Hud- son River span. This will be on the New Jersey side of the river. At the same time, across the continent, a corps of noted engineers headed by Robert Ridgway, veteran New York subway builder, are working on the difficult problem of select- ing the site for the California bridge, which will stretch from San Francisco across the bay to a point in Alameda County. In these two gigantic projects the science of bridge building attains a scale which, only a few years ago, seemed be- yond the range of the practical. They are possible today only because men of in- genuity and courage have overcome seemingly impassable obstacles with new inventions and materials. For skill and daring the bridge builder is in a class by himself. From far below the equator to the frozen North, strands of cable are being spun over swift cur- rents, and leaning towers of steel spring from widely separated banks to meet in mid-air. To these spinners of lofty steel webs, a single misstep often means a watery grave, with, perhaps, an iceberg for a monument. Vision, for instance, a bleak June day on the Copper River in Alaska, a few years ago. Bridgemen are anchoring their caisson to the shore, when a thunderous Right: World’s greatest cement bridge, spanning the Seine River at St. Pierre du Vauvray, France, 430 feet long and 114 feet high eA New Era 0 July, 197, roar echoes across the ice-choked channel. A monstrous berg detaches itself from the great Miles Glacier and plunges into the icy depths. Now a wave of tidal proportions rolls toward them. In a few moments it has picked up the great steel cylinder like a plaything, and has flung it many yards away on the shallow bar. Not until days - later can it be jacked back into its appointed place. This was only an incident of that job, one of the daily and hourly assaults against supermen who dared to bridge a river of ice and icebergs. Deep snows, hundred-mile gales, rains and floods and bitter cold, freezing the river to a depth of nine feet, successively challenged their ingenuity. But a rich copper country was at stake. The tale of their bitter struggle for its opening is an epic of the North. Borings and surveys were made with superhuman efforts. Thousands of miles away, the planning and fabricating were completed. Erection began on piers s0. carefully located that the largest bergs could not reach them. Floating ice tore away parts of the concrete forms as they were erected. A tower, supporting com- pressed air pipes, was built on a cofferdam resting on the river bed. Sensing danger, the bridgemen built a new tower on cables swung over the unfinished pier. A few minutes after the pipes had been moved, the old tower and cofferdam were lost in the rising water and ice! "THE biting cold of the following win- ter caught them unexpectedly early, with a concrete pier yet to be poured. They built a housing around the pier and heated the interior. Concrete, water, sand and rock were heated to more than 100 degrees, mixed on shore, and carried overhead for a third of a mile in bitter cold, to be deposited at an average tem- fas Zanesville, Ohio, boasts the only three-ended bridge in existence. Muskingum River in the form of a Y, giving access to tw > separate points on one side of the river This odd structure crosses the Juls

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July, 1977 — se ting were piers so est bergs z ice tore s as they ing com- -offerdam g danger, tower On i pier. A 1ad_ been lam were ving win- lly early, > poured. pier and +» water, iore than d carried in bitter ‘age tem- ses the he river July, 1927 How Engineers Plan and Dare to Build Mile-Long Spans. of Steel By Orvit_te H. KNEEN POPULAR SCIENCE MONTHLY 25 ‘ Re wnat Aik ea iy Bah y es Wy Hl ( As \ A am 26 OS Ue perature of seventy degrees. The pier was perfectly molded, an unprecedented feat. In the spring the ice renewed its drive on the falsework. The river rose, swollen by rains. For days and weeks, armed with steam jets and ice chisels, the bridge builders defended their position. Many times the falsework groaned. But in the end the bridgemen won. A ten-million pound web of steel today rises far above the charging ice floes, carrying long ore trains to and from the heart of the copper country. Year after year it is resisting the combined attacks of the Arctic. I asked Dr. D. B. Steinman, one of the country’s most resourceful bridge engi- neers, why it is that in scarcely half a century such stupendous bridges have become feasible, almost commonplace. “We are just entering an era of bridge building which will far exceed the present achievements,” he told me. “The motor car is the basic cause. It has brought the spirit of travel to millions, and they desire to move in reasonably straight lines. In the movement of goods, too, every mile saved opens up new fields of industry. ” par eone recently our great rivers and bays were considered insurmount- able. Even when we learned how to bridge them safely, the cost of long spans seemed excessive. But today the building of a great bridge is simply a business enterprise. We determine in advance the best type of bridge and its cost. We com- pile traffic records and anticipate its growth. For the larger structures we establish small toll charges, more than enough to pay all operating costs. If the revenue will repay the entire cost within, oe. — — Tacoma, Wash. An unparalleled engineering feat—How counterweight boxes filled with sand quickly lifted the 750- ton center span of the new bridge over Carquinez Straits, Calif., into its place 135 feet above the water The highest timber bridge ever constructed (above) carries the tracks of a logging railroad 893 feet across the Cedar River near It contains 836,000 feet of lumber. Cf two-deck construction, it reaches a height of 204 feet. At the left is a remarkable example of modern steel arch construction—the $10,000,000 bridge over the Mississippi River at St. Louis, Mo. say, twenty years, the project is a good investment. The community finally re- ceives the bridge, which has been paid for by its users.” “But why,” I asked, “are engineers so confident that much larger spans can be safely built?” ** Because we now understand the forces and materials with which we are dealing. We have new materials, of known strength, and capable of infinite variety. Moreover, we have evolved a science of design, and have invented new structural forms and combinations, such as the truss. “You may be surprised to know,” he went on, “that the suspension principle of the Brookiyn Bridge, with overhead cables to carry the load, was invented by primitive man. We have been unable to - improve on this principle; the basic idea was perfect from the outset. Our appar- ent progress in this type, now enabling us to project single spans approaching a mile in length, has been largely in devis- ing better materials, tools and labor- saving methods in erection. “Primitive bridges invariably followed the suspension type, wherever native vines or plants permitted. In Peru ex plorers recently found a 148-foot span of fibrous roots flung by daring natives far above a deep river. Even longer spans, many prehistoric, have been found in India, China, Australia, Mexico and South America. Whole tribes have been known to cross mountain rivers on stout cables spun of vines or even animal hides, the ends securely anchored to trees or rocks, with a rough floor of logs lashed on. Perhaps an arrow carried the first string across. “Such bridges, while light and shaky, will carry even pack animals. Twenty- five men at a time, for instance, can cross a 100-foot chasm (Continued on page 128)

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POPULAR SCIENCE MONTHLY July, 1927” ouriers | hat Never Fail Game to the Last, Thoroughbred Homing Pigeons Carry On When Even Radio and Airplanes Falter By Jack O’ DONNELL ESPITE the amazing develop- ment of the telephone, the telegraph, the airplane and other means of rapid communi- cation in the last quarter of a century, the humble homing pigeon still remains one of the surest, safest and most faithful messengers to which man turns in his hour of extremity. When static interferes with the wire- less, when wind or storm or sleet or snow level telephone and telegraph wires, when rivers or creeks overflow and wash out railroad bridges, when airplanes lose propellers; in short, when all other means of communication are at a standstill, the sturdy, courageous and intelligent little homing pigeon may be, and often is, called upon to bridge the gaps between isolated sections. These feathered messengers, which were first imported to this country from Bel- gium back in the late ’sixties, have played important réles in time of peace and in time of war, in sport and commerce, as messengers of mercy and—of Cupid. Their part in the World War forms one of the most glorious and romantic chapters of American history. When all other means of communication between men in the front line and their artillery sup- port failed at Grand Pré, a little one- pound homing pigeon made its way through lead and smoke and gas to - American headquarters, bearing the mes- sage that brought relief and saved the day for our forces. , It was 2 homing pi- geon, all but mortally wounded, that came back from the Lost Bat- talion in the Argonne to General Headquarters with the message that gave the exact location and the condition of that ill-fated command. Time and again these little fliers have been the only means of sending news of disasters, such as the Corpus Christi (Texas) flood of a few years ago, out of the stricken areas. Is it any wonder that these birds have won the respect and admiration of men and women all over the world? Is it any wonder that there After a flight of 2,000 miles, this faithful hom- ing pigeon was picked up, wet and ex- hausted, on a New York street. On one of its legs was a message telling that Dr. Edmund Heller, famous naturalist, was lost in the Hoodoo Mountains of Yellow- stone National Park, Wyoming. The bird’s courageous flight summoned a rescue party are more than 15,000 organized pigeon- eers and perhaps 300,000 unorganized owners and racers of homing pigeons in the United States? While a vast majority of the thorough- bred homing pigeons in the United States are kept solely for racing purposes, others - bed i a The start of a recent spectacular race between a thousand homing pigeons and an Army airplane, from Washington, D. C., to Baltimore, Maryland. The pho- tograph shows the release’ of some of the pigeons near the Washington Monument iv Og ee si are used extensively by commercial con- cerns in the mountainous regions of the West and Northwest where thousands of villages, crossroad stores and farms are without regular mail or wire service. In those sections salesmen carry the feathered messengers.in specially con- structed boxes on the running boards of their automobiles and use them for emergency or rush orders. One large flour company on the Pacific coast keeps a loft of 500 homers at its Western headquarters. Thousands of rush orders are brought to the main offices by these pigeons every month, much more promptly than they could be delivered through “regular channels.” HE best homing pigeons, when well trained, fly from five to seven hun- dred miles in a day without “dropping” for food or drink. The average commer- cial bird, however, will not average more than two or three hundred miles in a day. While there is a wide difference of opinion as to how homing pigeons find their way home from distant points— some holding it is instinct that leads them; others that it is due to their telescopic eyes and prodigious memories— the weight of authority appears to sup- port the latter school. Scientific tests have demonstrated that without its wonderful memory, its extraordinary powers of sight, observation and endur- ance a pigeon could no more find its way home from a distance of sev- eral hundred miles, un- 1 less it had first seen some of the intervening land- marks, than could an aviator, without mechan. ical instruments and maps, find his way from Canada to the Gulf of Mexico. ; The training of hom- ing pigeons is an art im itself. It requires great patience, a vast amount of time, and long hours of watching and waiting. This training _ begins when the squeaker, or baby pigeon, is six weeks old. The first thing it is taught is that the rattle of a can of grain is the taught to go quickly (Continued on page 112) rr tell call to meals. It is then

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July, 1927 _ ial con- ; of the yusands | farms service, ry the ly con- yards of em for Pacific ; at its inds of e main month, ould be els.” en well on hun- pping” ommer- xe more 1a day. ence of ns find oints— t leads o their 1ories— to sup- ic tests out its rdinary endur- ould no y home of sev- les, un- en some ig land- uld an nechan- s and ry from Gulf of of hom- 1 art in *s great amount g hours waiting. begins ker, or x weeks ing it is e rattle 1 is the is then quickly mage 112) July, 1927 What Ga e Do Yrou Play: There’s an Age Limit for the Average Man in Every Sport—How to Take Stock of Yourself By ARTHUR GRAHAME - ROPS Dead on Golf Links.” That headline ap- pears in the newspapers.much too frequently for the mental comfort of those of us who have stepped unwillingly out of the charmed circle of youth but still like to take our exercise at first hand. “G, Henry Blank,” we read, “53 years old, prominent in banking circles, died yesterday morning while playing golf on the course of the Clearfields Country Club. After making a good drive off the first tee, Mr. Blank complained of dizzi- ness and shortness of breath. While waiting his turn to drive from the second tee he collapsed suddenly. Physicians said that death had been caused by heart disease.” Disturbing reading for the man ap- proaching or past the forty-year mark, whose love of keen competition and a good sweat makes him unwilling to ex- change the joys of active participation in sports for a seat in a baseball grandstand POPULAR SCIENCE MONTHLY or behind the steering wheel of a motor car. More encouraging are the news items on the sporting page. Youth must be served, but often, he learns here, youth must wait modestly in the back- ground while some veteran athlete gath- ers a few more honors. Devereux Milburn, who is 46 years old and has been -playing polo for thirty years, shares with Tommy Hitchcock, who is 27, the distinction of a ten-goal handicap, the highest rating of American polo. Clarence De Mar, close to the 40- yedr mark, continues to win grueling Marathon races. Walter Johnson, in his fortieth year and starting his twenty- first year of baseball, continues one of the greatest of pitchers. Last October, Grover Cleveland Alex- ander, then in his fortieth year, saved the World Series for the Cardinals. Matt McGrath and Pat Ryan, both nearing fifty, hold their places = bf among the great weight throwers of the world. John Ball, famous British golfer, won his first amateur cham- pionship in 1888, his last a quarter of a century later, and half a dozen of them between. Sandy Herd won the British professional golf championship at the age of 58. Arthur S. Lyon, who is 50 years old and weighs only 120 pounds, is the best saber fencer in America, and in the last two international matches against strong Brit- ish teams won every one of his bouts. These all are veteran ath- letes who continue to hold their own against much younger men. In some sports, notably golf and tennis, special provision has been made to provide com- petition against men of their Though he’s nearing the fifty mark, Matt McGrath, world record weight thrower, still holds his own against younger competitors own age for players who have reached the “veteran” 27 Pr Devereux Milburn and Lord Wodehouse, famous polo players, are outstanding examples of men who, in the middle forties, aren’t worrying—yet—about “quitting time.” But they never allowed themselves to get out of training stage. The annual championship tourna- ment of the United States Seniors’ Golf Association attracts three or four hundred golfers who compete in five age classes— 55 to 59, 60 to 64, 65 to 69, 70 to 74, and over 75. Last year’s championship was won by Frank A. Hoyt, of the Engineers’ Country Club, who, competing in the 55 to 59-year class, shot 152 for thirty-six holes over a difficult course—a long way from the usual conception of “old man’s golf.”” Even more remarkable was the performance of F. P. Abercrombie, of the Philadelphia Cricket Club, who had a winning score of 186 for thirty-six holes in the 75-year class. In tennis the national veterans’ championship, open to players 45 years old,or over, provides sport much higher in quality than that seen in most club tournaments open to men of all ages. UT such men form only a small de- tachment of the army of “over forty” players. Most of us, as we reach the middle years, are willing to play for the fun of the game and leave champion- ships to others. The Earl of Balfour plays both tennis and golf at '79. John D. Rockefeller, now 85, enjoys his daily golf. The venerable Bishop of London, who visited us recently, engaged in a tennis match with Miss Helen Wills. John Allaire, vice president of the Amateur Fencers’ League, who is 68 years old, fences for two hours four days:a week. Secretary of War Dwight F. Davis, who gave tennis the Davis Cup and with ’ Holcombe Ward held the national doubles championship almost thirty years ago, still plays tennis when he can find time— and plays a strong game, as does his old partner. And in almost any club devoted to sports you will find some “old-timer” who is able to make the best of the young- sters step lively to beat him. Against all this stand those frequently read headlines, “Drops Dead on Golf Links.” Is there a definite quitting time in sport? If there is, when do we reach it?

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POPULAR SCIENCE MONTHLY Naturally, in many cases the heart can’t stand the sudden strain. The man who wants to continue his activity in sport through middle life never should allow himself to get out of coudition. If he intends to play tennis in the summer, he should play indoor tennis dur- ing the winter, or take up some other game. Personally, I’ve found that bowling, sup- plemented by setting-up exer- cises, keeps me in good condi- tion during the off-season. “Sometimes, of course, cir- cumstances make it necessary for a mzn to give up sport for a year or two. If he is organ- to his game by starting very carefully and slowly. A few games—not sets!—of the easi- est kind of tennis is quite enough for a man who hasn't been playing for a year or so. I set out to learn the answers to those questions. The first man I went to was Dr. Philip B. Hawk, well-known dietitian and food research expert, who held the national veterans’ singles tennis championship from 1921 to 1923 and has been a strong contender for the title each year since then. And, by the way, veterans’ tennis as played in the national veterans’ campionship is no game for decrepit old gentlemen—far, far from it. It’s as hard and fast a game as any other variety of high-class tennis. Doctor Hawk is 52 years old. “When,” I asked him, “should a man give up tennis?” “That depends entirely on the man,” said Dr. Hawk promptly. “If his heart is in good condition, he need never give it up. I’ve been playing for more than thirty years, and believe I put up as good a game today as I ever did. “Of course,” he went on, “as a man grows older he must take precautions that a youngster isn’t likely to bother about. Every man over forty who takes part in any strenuous sport should go to his physician for a thorough physical examination before the opening of the season. I always do that. Heart troubles sometimes de ‘op rapidly, and if there is anything wrong with me, I want to know it before I take any violent exercise. And the tennis player who has passed forty should work out very carefully in the early part of the season. He never should place a sudden strain on his heart —or on any other part of his body, for. that matter. EMEMBER, though, that you can’t draw general conclusions _ from one man’s experience. I’m fortunate in being a descendant of strong, long-lived people, and that counts for a great deal. And I’ve never given up active play. That’s a really dangerous thing to do. Many young men engage in strenuous sports in college, take no exercise for the first two or three years of their business careers, and then try to go back to sport. The venerable Bishop of London put up a strong game as partner of Helen Wills in California recently. Regular pr >c- tice makes it possible to play tennis, at least, indefinitely “Quitting time? For the normally healthy man, there is no quitting time in tennis. Sensible living the year round, the precaution of a physical check-up once a year, and careful practice in the spring, should make it possible for a man to play tennis indefinitely. I, for one, hope to stick to the game as long as I can carry a racket around the court!” Next I went to Daniel Chase, former New York State director of physical education and chief of the New York State bureau of physical education. Mr. Chase is executive secretary of the Sportsmanship Brotherhood, an organiza- tion whose chiéf object is the teaching of the spirit of sportsmanship to the young people of this and other countries. He was for some years director of athletics at ° Hamilton College, and while at the head of New York State’s physical education forces made a special study of sports and exercise for middle aged men and women. I told him about those “Drops Dead ically sound, he can get back | switch to golf. July, 1997 ; sport. Golf is an exception—the exertion it demands is not severe or sudden, and for a man who is in ordinary good health golf is a safe and beneticial game at almost any age. Swimming is another exception, exercising every muscle of the body with. out strain. ** Baseball is a fine game, but I'd draw the danger line at about forty—perhaps a few years earlier—except for the pro. fessional who plays day in and day out through the season. The ‘business vs. pro- fessional men’ games that are a feature of so many outings are bad medicine. | don’t believe in baseball for men over thirty who do not use their bodies pretty steadily. It isn’t good, for example, for mill operatives who sit down all day at their work. Playground ball, which is baseball played on a small diamond with a soft ball, gives the players the same fun and zest of competition without the danger of heart strain. " T= danger line in track athletics for the average man must be drawn a little after thirty. One of the most dan- gerous sports in the world is the ‘fat men’s race,’ another favorite at outings. Com- pared with it, polo, hockey and automo. bile racing are safe. The 250-pounder of thirty or forty who indulges in a fifty-yard burst of running is asking for trouble, “Tn tennis it is more difficult to fix the danger line. It all depends on the player. The man who is able to play every day, or almost every day, and has been accus- tomed to doing it for years, can go on playing all his life. “Provided a man keeps fairly steadily at his game, he can continue to take part even in strenuous sports until he is well into middle age. The whole secret is never to get altogether out of training, and never to place a sudden strain on the heart. If you haven’t time to play enough tennis or baseball to make it safe for you, And remember that the most dangerous thing to do in sports is to give them up altogether. Every man should continue to play some game.” on Golf Links” headlines. “Yes, I have seen them, too,” . said Mr. Chase-“‘And, of course, many people, of all ages, have asked me about this so-called ‘golf suicide.’ “Now, we can’t get away from the unpleasant fact that men do drop dead on golf links. Nor can we get away from the fact that men drop dead in other places. For example, many people are overtaken by heart failure while climbing the stairs on their way to bed. The differ- ence is that when a man dies suddenly whiie playing a game it is news; if the same man were to die suddenly in his home, it would excite no comment. “But I do think there is a definite quitting time for the average man in almost every America’s best saber fencer, Arthur S. Lyon, won the last international match against Britain. Yet he, too. is past 50

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July, 1997 Juty, 1927 POPULAR SCIENCE MONTHLY 29 exertion den, and ‘a “a! Broncho-Busters of the Air it almost : cceptions dy with. . ; rad By A test pilot tells Ww . esha experiences of the 1e pro- 7 4 . day a Cy CALDWELL men who fly untried Yeon planes—How two icine. J HEN the two fa- f th t d 1en over — —_ = O em se a recor pilots, Clarence D. ' nile, Chamberlin a n d for nonstop flight | day at Bert Acosta, recently drove & which is thenew W right-Bellanca mon- a new type of airplane is ynd with oplane continuously for fifty- accepted for testing by the ame ful one hours, eleven minutes and United States Army or Navy, out the twenty seconds, they did more and before a Government pilot than shatter the world’s record is allowed to fly the machine, for duration flight. They put its safety must be demon- letics for their ship through the greatest ry strated by the manufacturer. drawn @ and most severe test ever given No matter what specifications ost dame to a flying machine. For two © ¥ may be written into the Gov- at men’s days and two nights and part ernment’s contract with an . Com of another day, while the plane airplane manufacturer, this automo. hummed steadily in a circular one always is included: “The under a course within a twenty-five airplane shall be demonstrated fty-vadil mile radius of Roosevelt Field, by the contractor to be a rea- trouble Long Island, the two pilots sonably safe flying machine.” o fix the took turns at the controls. And the man who does the » player. Each, in turn, was able to demonstrating is the com- r day, @ snatch a bit of rest or a wink of pany’s test pilot. He is the » accel sleep. But not once during first man to leave the earth in n go on those weary hours was respite this carefully-wrought mate- given to the 200-horsepower rialization of an aeronautical steadily air-cooled engine which drove engineer’s dream—and some- ike part them onward. Not once was times engineers have bad » is wae a strut, brace, bolt or fabric dreams. ecret # relieved of the strain of flight. From the fact that he is the raining, Yet, when the last drop of first man up in n on tie the $85-gallon gasoline supply oy an untried plane enough a er — nal og ta —which Lea for you, iers glided to a safe landing, ‘ conceivably, do hat the after traveling 400 miles far- ar Romer Pre anything with rts is ther than thedistancefromNew monoplane when it com- him—there has -y oe York to Paris, mechanicians pleted its record flight grown the idea a * reported the machine in “as po Bat ert that testing new good shape as at the take-off!’’ onds. At right: Clarence airplanes must —_ This world’s record was a D. ey so cock- ' be extra-hazard- supreme triumph for two of the sll bey Al em aan ous work, Actu- airmen whose almost daily job took turns at the controls ally. it is not. ngineering knowledge and experiment have advanced so far it is to risk their necks putting airplanes of new design through their first paces. They are the bronchobusters of aviation. To their daring and skill is due much of the present progress in mak- ing heavier-than- air machines safe and reliable thatacapableen- gineer may esti- mate accurately not only the air stresses that materiais to be used in the new plane must withstand, but also the high and low speeds, the rate of climb, and the altitude that the projected plane will attain—and that before a single part is made. . A plane is standing on a factory flying field awaiting its initial test flight. It is a large bomber and torpedo-carrier built for the U.S. Navy. As the parts were made, many specimens were broken to discover what strain they would bear. If the part proved unable to withstand a strain of from five to twelve times what it would have to withstand in flight, it was The author photographed from the air while testing a new Navy bomber. “It’s not so hazardous as you might think,”’ he says, “‘for every part of the machine has been thoroughly tested before it goes up into the air”’ redesigned. The completed units have been subjected to loading to find what load each unit (Continued on page 130) carriers. Always, for example, before he last past 50

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% .° POPULAR SCIENCE MONTHLY July, 1927 July Trathe Cops of Other, Lands Seagal. | A military uniform distinguishes the traf- fic officer of Paris (left) —though Americans who find it all their lives are worth to cross a Parisian boule- vard sigh for the mili- tary precision of New York’s traffic system E us a as A raised club, a shrill whistle—these mean “Stop!” in Madrid, Spain. At least there’s nothing ambiguous about this, even to the foreigner Sunny Honolulu, Ha- waii, provides its cops with all the comforts of home—a _ comfort- able seat and an um- brella as protection against the glaring sun so Wherever a street intersection is, this genial cop Unique bull’s-eye wristbands help make the of Belgrade, Serbia, is guarding it. White hand signals of traffic policemen at Ber- gloves help make his signals plainly visible lin’s crowded street intersections conspicuous In Oporto, Portugal, the traffic cops you meet The “‘bobbies”’ of London have capacious slickers-—-and Traffic cops in Stockholm, Sweden, carry A on the most peaceful street corners carry wear them often.. White sleeve bands make their sig- swords. They operate red and green lights € diminutive revolvers and signal with clubs nals visible through the dense fogs of the British capital which signal to drivers whether to go or stop

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uly, 1927 club, a ‘le—these op!” in oain. At 3 nothing bout this, foreigner ake the it Ber- picuous July, 1927 POPULAR SCIENCE MONTHLY Each of the millions of baseballs used every year in American parks and sandlots starts in the factory as a little ball of cork and rubber The cork-rubber core goes to a winding machine that wraps it with three layers of resilient woolen yarn From a Bouncing Little Marble of Rubber to Fame over the Fence Over the yarn is stretched the cover—two “figure eight’’ pieces of tough horsehide sewed together by hand; 216 stitches to each ball The finished ball, weighing exactly | five ounces, is a triumph of mechan- H ical science and patience. Now it is ready to meet its fate in a ball park The grand finale. Babe Ruth clouts it high over the wall for a home run, and Soars eee ’ —the kids on the other side of the fence scramble madly for the prize. S> another of we a big league club's yearly quota of about 7,000 baseballs passes into the unknown

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32 POPULAR SCIENCE MONTHLY Glenn Curtiss Sees A Vision of Aviation’s Future Motorcycle planes, weighing 40 pounds and carrying commuters from home to work 300 miles away; radio power and pilotless craft predicted by air pioneer Reported by FRANK PARKER STOCKBRIDGE OOKING forward in the effort to visu- alize the future of aviation, some things seem crystal clear to me. But looking backward, over twenty-two. years of aerial experimentation, be- ginning with my first associa- tion with Captain Tom Bald- win in building dirigibles, I recall so many dreams which failed to materialize that I hesitate to commit myself to definite predictions. Let what I have to say here, then, be taken merely as my pres- ent beliefs, rather than as definite prophecy: That every city planned in the future will have a conveniently situated aviation field as an essential part of the plan goes without saying. Present cities not so equipped will have to provide such fields. Flying from city to city, or from sub- urbs to the city and back, will be one of the most important developments of aviation in the near future. Aviation will greatly extend the suburban areas of our cities. Already many men of means are using flying boats for “commuting” between their waterside suburban homes and water-front cities. The first flying boat which I sold to a private customer was purchased by Harold F. McCormick, I think in 1914. Mr. McCormick used it for several years for his daily trip from his home at Lake Forest, IIl., to his office in the Harvester Building, landing and departing from the Chicago Yacht Club Basin in the heart of downtown Chicago. HE flying commut- er, however, must have something besides the flying boat. Just be- fore the war we built what we called an auto- plane, a sort of flying automobi'2, with an in- closed, streamlined body, mounted on four wheels which could be steered when on the ground. It had the en- gine in front and ‘the propellerattherear, and was designed to elimi- nate much of the risk of bad landing fields and “Hovering” type of plane. designed by Curtiss, which he believes may solve the problem of safe landing in the heart of cities. practically stand still in the air It can The war put a stop to our experiments. With the development of wireless transmission of power there will eventually be perfected a personal airplane so individual, so compact and so flexible that it will compare with air- planes as the motorcycle does with forced landings. automobiles. This will be the type of aircraft chiefly used by commuters. & I see the flying motorcycle, it will be built entirely of duralumin or some other light alloy, with folding wings. The body will be just large enough for one man tositincomfortably. Rollers, rather than wheels, will be the landing gear. It will have a wing-spread of about twelve feet, a lifting surface of, say, fifty square feet, and weigh around forty pounds. It will have a lifting capacity of about 200 >> y or Curtiss built this autoplane for the “flying commuter”’ before the war. Today he predicts we'll fly to work in “flying motorcycles’? having folding wings aad roliers for wheels pounds, leaving 160 pounds for motor and passenger, This presupposes a mueh lighter motor than any now made. Great power will not he required, of course, for high speed will not be desir. able. At the Curtiss plant on Long Island several of our young engineers experiment- ed with sma!! planes. Rivalry as to who could fly the small- est plane arose among them, and some remarkable results were obtained, using air. cooled motorcycle engines, No motor yet produced, however, is light enough {or the commuting flyer’s indi- vidual plane. What is needed is weight- less, or practically weightless power. BELIEVE that will come. In view of what has been accomplished already in radio transmission of energy, I may not be peering very far into the future when! visualize a central source of energy, send- ing out waves to which the commuting flyer can tune-in his plane. His fiying range will probably be short, but sufficient to get him to the city and back every day from a distance of perhaps fifty miles. That development only awaits the logical next step in radio engineering, and I have seen so many marvelous developments in that field that I believe this one, too, may come in my own lifetime. For the long-distance commuter, travel- ing two or three hundred miles daily from home to office, the large multi-passenger plane, or flying bus, will be the main re liance. Such machines, dependable and _ eco- nomical, have already been built. Refine ments in such matters as emergency control are well within the reach of present knowl - edge. The flying bus will also carry mail. It will be a multiple-plane machine, with two or three 500-h. p. engines, inclosed cabins, ample reserve power for storms or engine trou- ble. It will fly at high speed, up to a possible July 150 call: Jat The Jong win fron win devi cop! prol fron mor buil first grou im{ requ for of I drea nati copt ing | ings in 0 it 1 utili area the then that who off t so fe on plan proc trafi nary Gov land wou dow mut or al poin in hi fast is t Jiner Lon dark kno nom mul a cr thre to k sam on eigh wou men hea mor seve fligh have the whic the ever add ity,

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July, 199 ES 0 pounds senger, ; &@ much any now r will not urse, for be desir. ‘iss plant ral of our periment- . Rivalry che small. ng them, le results sing air. engines, produced, ough for er’s indi- s weight- wer. n view of | already “may not -e when! gy, send- mmuting ‘is flying sufficient very day ty miles. 1e logical id I have ments in too, may r, travel- 1ily from ice, the assenger ing bus, nain re 1achines, nd eco already Refine- matters control hin the t knowl bus will . It will le-plane two or engines, , ample yer for ne trou- at high possible July, 1927 150 miles an hour, and so designed as to be able to hover over one spot and practi- cally stand still in the air. One of our own Janes embodied this hovering principle. The five wings were rotatable on their jongitudinal axes, sike an ordinary window shutter, so that the back-draft from the three propellers, acting upon the wings, produced a lifting effect. POPULAR SCIENCE MONTHLY pound must be added to the basic weight of the machine. Anything approaching regular air pas- senger service across the ocean must wait upon great improvements in navigating instruments, both as to accuracy and reliability. Night flying and flying in fogs must be made safer than at present. It 33 the ocean. Today a perfectly private conversation can be carried on intelligibly from any part of the United States to England; signatures to checks and other documents have been transmitted over- seas by radio and accepted by banks and courts; photographs are readily trans- mitted. All of that reduces the demand for speedier flight from conti- [ believe this type of hovering device, rather than the heli- copter, will help | solve the problem of landing in or arising from a limited area. At Ham- mondsport, many years ago, we built what was, I believe, the first helicopter to rise from the ground. Contrary to popular impression, the helicopter requires a great deal of space for safety, because of its lack of lateral maneuverability. The dream often pictured by imagi- native artists, of fleets of heli- copters alighting upon or depart- ing from the roofs of tall build- ings, will always remain a dream, in my belief. I doubt whether it will ever be practical to utilize city roof tops for landing areas. Air currents produced by the presence of the buildings themselves will always make that dangerous. To roof over whole city blocks would shut off too much light and air. And so far as relief from street traffic congestion goes, a very few planes in the air at one time can produce a much more serious nent to continent. In much less than fifty years, however, I expect there will be regular air mail routes estab- lished across the Atlantic. Car- rying mail is a much simpler job than carrying passengers. Mail matter, moreover, represents almost the only class of com- modities which can stand the freight toll of air transportation over long distances. Even silk, once the most precious of regular freights, no longer can pay such high transportation charges; rayon has cut into the silk market and reduced the demand. The greatest developments of the next few years in aviation, aside from preparations for the next war, will be in the mail service and in passenger car- rying between cities. In fact, the airplane is rapidly approach- ing the point where it will be the most economical means of trans- portation for men whose time is of value. highway route between Miami, Florida, where I live, and Venice, on the opposite coast of Florida, traffic congestion than the ordi- nary man imagines! In the case of New York City, Governors Island offers an ideal landing field. A short subway tunnel would bring it within five minutes of downtown Manhattan. The aerial com- muter will tie up his flying motorcycle or alight from his flying bus at some such point as that and be at his office or shop in half the time it now takes him by the fastest available means of travel. pm popular dream which I do not expect to see realized in my time is that of the swift trans-Atlantic air liner, filled with passengers, flying from London to New York between dawn and dark. It can be done, but with our present knowledge it is both uneco- nomical and unsafe. A multi-passenger plane with a cruising radius of two or three hours in the air is easy to build. But to carry the same number of passengers on a@ continuous eighteen-hour flight would require an im- mensely larger and heavier machine, with more engines, and six or seven times as much fuel ca- pacity. And to add further flight duration there would ave to be conveniences for the comfort of passengers which can be eliminated in the short-radius plane. For every pound of useful load added to an airplane’s capac- ity, considerably more than a Glenn Hammond Curtiss as he is today. From the start, as experi- menter and builder, he has been a leader in aviation. He has done more, probably, than any other to make flying easier, safer and more popular may take fifty years before such a regular service, with aircraft competent to sur- meunt the hazards of storm, is established; and by that time the need for it may easily have passed. It took fifty years after the first steamship, the Savannah, crossed the Atlantic in 1815, before regular, scheduled sailings were possible. At present the cost of trans-Atlantic flight, assuming that it were safe, would be prohibitive to all but a very few; and recent developments in radio and tele- vision have made many of the things unnecessary for which men of great wealth might pay for fast transport across How the Curtiss “flying lifeboat,’ built during the war, cruised safely to land after shedding its wings. Flying boats will play an increasingly important role, Curtiss predicts where Mr. Stockbridge lives, is more than three hundred miles; the rail route is at least a hundred miles longer. Every time we have met to work on this series of articles for PorpuLAR SciENCE MONTHLY, one or the other of us had to make an eight-hour motor trip or a twelve-hour railroad trip, spend a night away from home and take as much time going back. The air-line distance between our homes is two hundred miles—easily flown in an hour anda half. If adequate airplane pas- senger service had been available, the time saved us would have been far in excess of the additional cost of transportation: Before such passenger service can develop to its fullest possibilities, before the aerial mail service can realize its fullest usefulness, great advances in night flying must be made. The time will come when we will look upon the present system of marking mail routes by searchlights and locating landing fields by the same means as_ ridicu- lously crude. As with coast light- houses, the time whenlights are need- ed worst is when they can’t be seen, by reason of fogs or storms. Up-to-date ships at sea are equipped with the (Continued on page 113) As an example, the

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What the human nervous system actually is like is shown in this remarkably complete rep- lica, the work of Dr. Rufus B. Weaver, noted anatomist, of Philadelphia. So valuable is the model regarded that it is locked in a vault of the Hahnemann Medical College, Philadelphia On these pages are presented each month brief stories of scientific discovery and research hav- ing practical bearing on our everyday problems. A New Electric Insulator HMEAPER deliveries usually mean cheaper goods—whether the com- modity be electricity or groceries. A new insulating material for high voltage transmission lines now promises cheaper electric light, heat and power for homes, office buildings and factories. The invention comes from the laboratories of Russian scientists headed by Dr. Abram Joffe, director of the Physical-Technical Institute of Leningrad. High pressure electric currents are al- ways trying to jump out of the wires that carry them, either from wire to wire or to the ground. To prevent this “leakage” elaborate and costly methods have been required. Tall masts, for instance, are fitted with wide-spreading cross arms to hold the wires far apart, while the wires themselves are suspended from expensive porcelain insulators. The Russian scientists say that a very thin layer of the new insulation—a com- paratively cheap, varnishlike material— will resist the pressure of high voltage fully as well as will the heavy, expensive porcelain. In round figures, they have shown that a film of the stuff a third of an inch thick will resist the pressure of a hundred million volts! POPULAR SCIENCE MONTHLY Latest Advances in Science If the new method proves practical, it may be possible to lay high tension lines in conduits and so do away with the present expensive pole construction. Send Color Photos by Wire OLOR pictures, in addition to black and white photographs, soon may be sent over long distance wires, officials of the American Telephone and Telegraph Company recently announced. The com- pany is planning to add color reproducing mechanism to its present apparatus. At present a person or business concern wishing to send a three-color picture by wire would have to send three separate photographs of the picture—one taken through a screen which filtered out all colors but red; another through a blue filter, and a third through a yellow one. The receiver would have to print the three different negatives successively in their respective colors on the same paper. The proposal now is to install apparatus at the various telephoto stations to de- liver finished color prints. Ethylene As Fruit Ripener NCE again chemical research pays big dividends. This time it is in the dis- covery of a method, announced recently before the American Chemical Society, of saving American fruit growers millions of dollars a year by the use of ethylene gas. Dr. R. B. Harvey, of the Collegé of Agriculture in St. Paul, Minn., is the dis- coverer. He has found by experiment that this gas, used in cutting torches and as an anesthetic, has the property of ripening fruit in an amazingly short time. Fruits which would require days or weeks to ripen on the trees now can be ripened, it seems, in a few hours. In addition, the gas averts danger of plant diseases. Sweeter fruit may also be July, 1927 556 in the world. Last year Americans sent more than 200,000,000 telegrams, o almost ‘two messages for every maj woman and child! : If Samuel Finley Breese Morse wer alive today to read these recently com. piled figures, he would rub his eyes at the miracle of invention. Smoke War On in New York EW YORK CITY has begun , scientific campaign to clear its ai of smoke. In the May issue of PopuLar Sctreneg Montuty, George Lee Dowd, Jr., re. vealed startling facts about the menace of smoke and dust in American cities. Short. ly afterward, came the announcement that.the New York health commission, codperating with engineers, had under. taken a survey of the city’s smoke con. ditions. Among other things, they wil make a count of smoking stacks and wil] estimate the volume of smoke emitted by industrial plants. Meanwhile, experts of the British Medical Research Council have estimated that London smoke shuts off at least sixty. five percent of the health-giving ultra. violet rays of sunlight. For the first time they have succeeded in demonstrating conclusively that one of the greatest injuries caused by smoke is the blanketing of these beneficial rays. Earth’s Bulgings Studied HE earth under our feet is not, ap parently, the “solid ground” we think it is. Dr. Sakuhei Fujiwhar, | Japanese earthquake expert, tells us that | the entire bed of the Pacific Ocean is rotating like a giant spinning soup bowl} And Charles Gorceix of the French Academy of Sciences adds that the earth a result of the gas treat- ment, for it is said to in- crease the fruit’s sugar con- tent, reduce its acidity, and make it more palatable. Moreover, it is claimed, a fruit crop may be distrib- uted over a period of weeks, instead of being dumped on the market all at once. ro U. S. Sends Most Telegrams MERICANS send more telegrams than all the people of Europe. A third of all the telegraph wires in “| aA | | | the world are in the United States. We have 2,220,002 miles of telegraph wires, compared with 2,662,740 miles in Europe and 6,549,- Permanent waving doesn’t injure the hair, announce Bureau of Standards experts, after recent tests to find out how much heat if various types of hair could stand without breaking. The photo {| shows C. R. Brown of the Bureau placing a strand of hair in the test oven, the door of wihich is opened by a weighted lever

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July, 1927 eS Americans egrams, or ery man, lorse were ntly com. yes at the w York begun 4 2ar its air R ScCIENcE |, Jr., re menace of es. Short. yuNncement mmission, ad under. moke con. they will 's and will mitted by e British estimated east sixty. ing ultra. first time onstrating greatest rlanketing died S not, ap- und” we ‘ujiwhara, Is us that | Ocean is oup bowl. e French the earth air in the i ted lever | July, 1927 POPULAR SCIENCE MONTHLY Insulator Promises Cheaper Transmission of Power—-Hair Waving Tested—Frutt Ripened by Gas— Other Discoveries probably is growing flatter at the poles and bulging out at the waist line. Still another scientist likens the bulging to that of an imperfect golf ball. At least two scientific undertakings within. the next few months will add much to knowledge of our globe. One, planned by the California Institute of Technology, will study land movements in southern California. Monuments will be set in a straight ted earthquake fault. line across a sus- If the monu- ments are twisted out of line in the next few years, it will be taken to indicate earthquake danger. The other expedi- tion, undertaken by the U.S. Geological Survey, will explore scientifically the vol- eanic Aleutian Is- lands, southwest of Alaska, one of the quakiest spots on the face of the earth. Rays Dry Up Paint Oils HEN, a few months ago, Dr. W. D. Coolidge of the General Elec- tric Company first demonstrated his new cathode ray tube and its remarkable prop- erties of working strong changes in substances placed in the path of its rays, everyone asked: Of what use is it? Today, at least one practical use has been found. Prof. J. S. Long of Lehigh Uni- versity has revealed distance transmission of radio waves. In this connection the German physi- cist, Prof. Werner Kolhorster, recently advanced the opinion that the mysteri- ous cosmic, or Millikan, rays, which are believed to be stronger fifty or 100 miles up in the atmosphere, may interfere with long distance radio waves. Wealth Wasted in Lightning VERY lightning flash you see repre- sents enough wasted electricity to light vour home for forty years and more. One flash, on the average, represents about 30,000 kilowatt hours of electric A tiny new microscope lamp is the latest aid to microscope users, developed in one of the great research laboratories. Attached under the plate, the lamp throws its light directly on the object being studied, eliminating shadows human ailments. The part of the nervous system which the cat lost was the “sympathetic” sys- tem controlling the animal’s ability to bristle its hair and to govern its-body tem- perature. In the human body these nerves are believed to govern blood pres- sure and the bodily effects of emotions. Other recent prog- ress in medicine in- cludes an iodine treat- ment for American sleeping sickness, de- veloped by Dr. Fred- eric J. Farnell, of Providence, R. L.; a new drug containing mercury derivative and chaulmoogra oil for treatment of lep- Lighting engineers hope to discover new secrets of ‘‘cold light’? from phosphorus, which they are studying at the General Electric Laboratories, Nela Park, O., with the remarkable apparatus above that cathode rays from the Coolidge tube will dry paint in amazingly short time. Exposing glass plates coated with linseed and other paint oils to the bombardment of electrons, he found that the plates dried in only two or three hours. Broadcasting from Balloons O STUDY how radio waves pass through the upper levels of the at- mosphere, two French engineers, Capt. Reginald Bureau and P. Idrac, recently sent up tiny floating broadcasting sta- tions equipped with vacuum tube trans- mitters in place of baskets. the usual balloon Automatic devices sent out a Succession of signals as the balloon pro- gressed upward, while radio engineers throughout France and Switzerland noted the variations in reception. While results of the novel experiment have not yet been announced, they are expected to reveal new facts which will be of value in the development of long power, worth more than $2,000 at pre- vailing American prices. Throughout the world something like 2,000 thunderstorms are going on all the time. In their lightning flashes, the earth is continually wasting more than four billion horsepower—nearly a thou- sand times more than all the electric power now generated in the world. These figures have just been announced by Prof. C. T. R. Wilson of Cambridge University, England. Cat Has Nerves Extracted FEW weeks ago Dr. W. B. Cannon, of Harvard University, performed a delicate operation on a cat and removed part of its nervous system. The cat, recovering, had the unusual experience of gazing upon its own nerves mounted on a card! It also made important con- tributions to scientific knowledge about nervous disorders, certain kinds of in- digestion, high blood pressure, and other rosy; the use of the spectroscope in the treatment of cancer for analyzing cancerous tissue; a serum treatment for peritonitis: and the begin- ning of research by the School of Den- tistry, Temple University, Philadelphia, to find a cure for pyorrhea. How Do You Sleep? HAT love and financial worries are two violent disturbers of sleep has now been demonstrated scientifically by Dr. H. M. Johnson in tests of eighteen university students at the Mellon Insti- tute, Pittsburgh. Among other things, the tests upset the belief that a normally healthy person “sleeps like a log.” In the experiments the volunteer students slept on special beds which recorded every movement they made during their slumbers. The results showed that the average straightaway period of rest during eight hours of sleep was only fourteen minutes. Each student “turned over” and changed his position on the average thirty-five times a night.

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POPULAR SCIENGE MONTHLY After the coal dust explosion, trained rescue men plunge into the smoke-filled experimental mine to test oxygen equipment and other rescue apparatus Uncle Sam's Toy Coal Mine How Scientists Play with Fire and Gas beneath the Earth ROM the black mouth of a coal mine, gaping in the side of a ra- vine, suddenly belches a terrifying mass of flame, with chokiny clouds of smoke and gas. A dust explosion—the thing most feared by coal miners—has swept through the workings with an- nihilating speed. Trained rescue men, wearing grotesque masks and oxygen equipment, plunge into the hole and grope through the murk. But in that mine, strange to say, are no men to be rescued. The only workers there to tell of the blast are marvelous instruments of science. For this coal mine is like no other in the world. It has no production nor profits. Operated by the U. S. Bureau of Mines near Bruceton, Pa., a few miles out of Pittsburgh, its sole output is new knowledge gained by re- markable experiments to make coal min- ing more efficient and less hazardous. Here engineers and chemists experiment to their heart’s content. Deliberately they fill the mine with coal dust and ex- plode it to learn of its hazards. They fill the workings with poisonous gas, then enter to observe the effects. At other times they test the safety of mining methods and machines. To study the effects of made-to-order ex- plosions, observation stations lined with con- crete have been estab- lished at intervals of 100 feet throughout the mine. In each of these are placed delicate in- struments which record the force of an ex- plosion and the speed with which it spreads. One instrument, for ex- ample, uses a ray of light to record on a photographic film va- riations in pressure produced by a blast. By M. E. Ciemenrs Another device causes a break in an elec- tric circuit when the flame of an ex- plosion passes, the break being recorded by the pen of a timing instrument con- nected in the circuit. These records trace the progress of an explosion from one observation station to the next. In producing an explosion, the experi- menters first scatter coal dust along the mine entries. Then they load a cannon with four pounds: of black blasting powder and place it on the floor of the main entry, pointing outward. An elec- tric switch at the surface fires the cannon. From the muzzle shoots a flame twenty feet long. The coal dust, flung into the Above: Conduct- ing ventilation tests with ingeni- ous apparatus in the depths of Uncle Sam’s ex- perimental mine Left: The geo- phone, developed for communica- tion between en- tombed miners and rescuers July, 1927 Sampling air in a mine tunnel espe- cially constructed to solve problems of ventilating the new vehicular tunnel beneath the Hudson River air, is ignited, and the explosion begins, Recent tests demonstrated that finely powdered rock dust, scattered through the mine, will act as a screen to stem the tide of explosion. Powdered limestone, dolomite and shale, in turn, were strewn lavishly along the mine passages. In every instance, when the cannon was fired, the explosion was checked immediately, hemmed in by a curtain of rock dust. Other experiments have aided in de. veloping methods of communication be- tween entombed miners and rescuers. By line radio, or “‘wired wireless,” voices have been transmitted from 400 feet be- low the surface. With the geophone, a war-time instrument for detecting tunnel- ing operations of the enemy, sledge ham- of ground telegraphy, Morse code has _ been sent through 800 feet of solid rock into the depths of the mine. Improved rescue ap- paratus likewise has been developed through knowledge gained by sending trained rescue men into the mine im- mediately after an ex plosion. Asidefrom mine safety, the Bruceton experiment- ers recently have studied the problem of ventilating long vehicular tunnels, such as the new tube under the Hudson River, and of removing deadly carbon monoxide gas of auto mobile exhausts. To measure accurately the contamination caused by auto en- gines, they actually constructed a test tunnel 130 feet underground and 1000 feet from the mouth of the mine Through it autos were run while instru ments recorded conditions of the at mosphere. mer blows in the workings | have been heard 650 feet | away. And by a method | wit of { me tw ver the In he: put ver ven tere all Ver will wo! Ver nob mec ous of stra alot liev

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July, 1927 1el espe- roblems ehicular n River 10 1 begins, at finely through stem the mestone, e strewn In every is fired, ediately, dust. d in de. ition be- uers. By ” voices feet be- phone, a g tunnel. lige ham- workings 650 feet . method egraphy, as been 0 feet of e depths scue ap- has been hrough ined by | rescue nine im- / an ex 1e safety, eriment- > studied vehicular nder the ‘ing the of auto- -curately 2uto el- d a test nd 1000 > mine, > instru- the at July, 1927 His Scran ge W orld Came POPULAR SCIENCE MONTHLY 37 rue How Some Amazing Prophectes of Jules Verne, Laughed At in His Time, Have Been Realized in Today’s Mechanical and Electrical Marvels ID you know that a Frenchman, born in 1828, not only fore- told, but described with amazing accuracy, several of the most outstanding of the mechanical inventions of the twentieth century—in- ventions which have changed the course of history? This man was Jules Verne. In his day he was famous (as he still is) as an author, for he put his forecasts of future in- ventions into the form of ad- venture stories of startling in- terest. Many a boy has sat up all night thrilling to the hair- breadth escapes of one of Verne’s heroes. His centenary will be observed next year the world over. But in the days when Jules Verne was writing his stories, nobody thought of taking his mechanical prophecies _ seri- ously; for he wrote of ships that flew through the air, of boats that traveled hundreds of miles under the sea, of strange vehicles that bounded along the road at an unbe- lievable speed, without horses to pull them. Of course these things do not seem strange to us, today. But Jules Verne wrote of them in days when people burned oil lamps, drove horses, and wondered whether railroad trains were safe to ride on! — reason why Verne’s proph- ecies of mechanical invention seemed mere fancies to his contem- poraries, was the fact that many of his ks were out-and-out nightmares of adventure, which nobody—not even the author—could be expected to take seriously. For instance, in “ A Journey to the Cen- ter of the Earth,”’ he tells how a German professor, his nephew and a _ guide descended several hundred miles into the: earth through the crater of an extinct Iceland volcano. There they found an immense sea, upon which they sailed for By Don KNowLTON eee Cad Jules Verne at 76. His enthralling books, in which his heroes used strange contrivances unknown in his time and experienced amazing adventures, have in many instances proven truly prophetic. Will fu- ture inventive genius realize still more of his fantastic predictions? days; witnessed a fight between a sea serpent and a great sea lizard, each forty feet long, monsters which still survived from prehistoric days; and finally, through a series of weird accidents, were spouted up on the crest of a column of boiling water and lava, until they shot out of Mt. Etna, as part of a volcanic eruption! In another yarn, Verne describes a trip from the earth to the moon. A giant gun, 900 feet long, was buried in the ground in Florida. The charge was 400,000 pounds of guncotton. Its bullet was a hollow conical projectile of alu- minum, in which rode three hardy ad- venturers, two dogs, and half a dozen chickens! The gun was shot at the moon, but en route the projectile was swerved from its course by the attraction of a meteorite. As a result, it rode, not to the moon, but around it, returning to the earth and falling, red-hot, into the Pacific! Its passengers, still alive, were rescued, and became the heroes of the day! In another story, “Steam House,’ Verne tells of a steam engine built in the shape of an elephant and drawing two trailers, which traversed the wilder parts of India. The passengers became. embroiled in a feud of vengeance resulting from the Sepoy revolt. In this, Verne was merely playing with science. HEREFORE, when, inter- spersed with these lurid phantasies, Verne produced books containing serious scien- tific prophecy, his enthralled readers attached no more seri- ous credence to the latter than to the former. In “20,000 Leagues under the Seas” —one of the most famous stories in all adventure literature—he put his characters on board a submarine which was prac- tically identical with our sub- marines of today. Yet people of his own time considered the submarine merely another Verne phantasy. Verne himself, though, took many of his prophecies seriously, as is amply evidenced by a cablegram which he sent to a New York newspaper in 1898 on the occasion of the thousand- mile voyage of Simon Lake’s submarine. The cable began, “While my book, ‘Twenty Thousand Leagues under the Seas,’ is entirely a work of the imagina- tion, my conviction is that all I said in it will come to pass.” He pointed to Lake’s vessel as direct evidence of this. It is fascinating, today, to look back at his predictions and to see how many of them have come true; to marvel at the shrewdest of them and to laugh at some which now seem to us absurd. In the main, Verne was right. People do fly through the air, pilot boats under the sea, and ride in horseless carriages. Em- inent scientists even plan seriously to shoot a rocket to the moon. But the

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38 methods by which these things are done are, in many instances, quite different from anything Verne imagined. Verne’s submarine proved the most accurate of his prophecies. The sub- marine of today possesses a remarkably similar construction. It delves into the depths of the ocean, it acquires great speed, and it covers long distances with- out rising to the surface—just as did Verne’s. Furthermore, the feats of Verne’s adventurers, who, by the aid of diving apparatus, oxygen sup- pliers, and electric lights, left his submarine, the Nautilus, and went walk- ing on the bottom of the sea, have since been duplicated. HE mistake which Verne made in re- gard to his submarine (a mistake which he also made in connection with his aircraft, as shown later) was in the choice of motive power. His submarine was propelled entirely by electricity. Electricity-producing substances were mined beneath the waves, the electricity was stored in vast batteries of untold strength, and away went the Nautilus, even to the South Pole! And yet, Verne was not so far wrong. How could he, in his time, have guessed the amazing motive power of petroleum? Be- sides, as far as naviga- tion beneath the sea is concerned, Verne was right—it is electricity which propels our pres- ent-day submarines, once they sink beneath the surface. Their Die- sel engines charge their storage batteries for this purpose. So Verne’s er- ror was merely one of ways and means. In- stead of underwater min- erals, we use subter- ranean oil. Among the most fas- cinating of Verne’s con- ceptions are his dream- flights in the air. The conquest of the sky had for him a tremendous fascination. Away back in 1863—during our Civil War—Verne wrote the first of his more famous stories of the air—‘‘Five Weeks in a Balloon.” In this yarn, he takes three adventurers across Africa in a balloon which can, if desired, remain in the air for days at a time, ascending or descending as the pilot wills. HE idea of the balloon itself was not, of course, new, for balloon flights of considerable length had been made be- fore 1863. But Verne undertook to show in this story that devices would be in- vented to enable balloons to remain in Courtesy Parke, Austin & Lipscomb Four illustrations from Jules Verne’s books, showing with what amazing accu- racy he foretold some of our modern marvels. “Twenty Thousand Leagues under the Seas,” depict the adventurers walking on the bottom of the ocean, and Captain Nemo on his submarine, the Nautilus. At the left, the moon projectile of “From the Earth to the Moon,” and above, The Terror, the strange submarine-auto-airplane of ‘“‘Master of the World’’ POPULAR SCIENCE MONTHLY the air for long periods and cover im- mense distances, without returning to a supply base for more gas. His guess in this direction is ingenious. His balloon was made to ascend or de- scend, not by alternately throwing out ballast and letting out gas, but by ex- panding or contracting the gas in the bag by changing its temperature. The bag was large enough to balance the balloon, when not quite filled with hydrogen at v sea level and normal temperature. If the hydrogen in the bag is heated, he rea- soned, it will expand, its air displacement will be greater, and so the balloon will rise. If, then, the hydrogen is allowed to cool, it will contract in volume, its air displacement will be less—and the bal- loon will descend. He therefore put on board his balloon a battery which decomposed water into hydrogen, rising from one electrode, and oxygen, rising at the other. These gases were then allowed to mingle and feed into a blowpipe, which in turn was used to heat a kind of stove much like the modern The two smaller pictures, from July, 1927 closed car heater of today. This stoye warmed the hydrogen in the bag. “Light the blowpipe!’’ cries his balloonist—apq the balloon shoots up. “Put out the blowpipe,” he ad yises, when he wants to land—the gas cools slowly, and the balloon drifts earthward. All this withoyt the loss of a single cubic foot of gas! Ingenious, yes—but history has not fulfilled this prophecy. Balloons haye covered long distances, and today we watch their crass-coup. try races with excite. ment; but no such device as that described by Verne has come into use, One would assume, at once, that batteries powerful enough to gen. erate sufficient oxygen and hydrogen to raise the balloon by the heat of their combustion as often as needed during long flights, would be so heayy that the balloon could not lift them off the ground. Verne must have been aware of this, for he has the inventor of this device state that the nature of his batteries is a “secret,” that they are made of “new metals and powerful acids” not heretofore discovered, But “new metals and powerful acids,” which might make a battery of infinitely light weight and great power, have not been discovered even today. N FACT, the swiftness of mechanical inven: tion and scientific dis. covery in Verne’s day seems to have led him into a fundamental er. ror in regard to the laws governing the genera tion and behavior of energy. His mistake in this direction is well illustrated by a quota tion from his delightful story, “‘Mysterious Is land”— a tale whieh chronicles the melo dramatic death of the inventor of the Nautilus, Captain Nemo. In this yarn, his fanciful em gineer, Cyrus Hard says that steamers burn water instead of coal, and continues: “Yes, water decomposed into its prim tive elements, and decomposed doubtless by electricity, which will have become & powerful and manageable force! Yes, my friends, I believe that water will one day be employed as fuel, that hydrogen oxygen which constitute it, used singly or together, will furnish an inexhaustible source of heat and light, of an intensity a which coal is not capable. Some day ame coalrooms of steamers and the tenders of | locomotives will, instead of coal, be stor with these two condensed gases, which will burn in the (Continued on page 110) [ Br the twe for str _ ‘she are for

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July, 1927 Lis stove __. Light ist—and out the wants to and the without gas! has not ns have day we »SS-Coun. | excite. ch device bed by into use, ume, at atteries h to gen. oxygen raise the heat of 1 as often ing long so heavy on could off the 1ust have is, for he r of this that the tteries is , they are y metals ids” not covered, tals and ”? which attery of weight er, have 2red even swiftness al inven: tific dis- ne’s day july, 1927 He’s America’s Orchid King! POPULAR SCIENCE MONTHLY These flowers took six years to grow! ORE than a_ hundred thousand orchids a year come from the plant of Thomas Young, Jr., at Bound Brook, N. J. Said to be the greatest producer of orchids in the world, he has devoted twenty years to the cultivation for the market of these prized and costly flowers. Some of his strikingly beautiful plants are ‘shown in the photograph above. From six to eight years of care are lavished upon each plant be- Heating plant of Young’s orchid farm orchids growing wild would take root. After they have been nursed and coddled in glass tubes, such as the one Mr. Young is holding here, the tiny seedlings are transferred to pots. Six mighty boilers keep the hot- houses at the correct tempera- ture for the delicate plants. Each year the plants are trans- planted until at last they re- ward the patient grower with their incomparable flowers. Many rare species with color- ings of vivid beauty, such as the Cypri- pedium_ above, are among the rows of plants in the unique glass-roofed farm. led him ental er- the laws genera- avicr of intakes New Pullmans Substitute Luxurious Bedrooms for Berths a quota lelightful rious e which e melo- 1 of the Nautilus, In this “iful en Hardi mers stead of fore even a single orchid appears. The seeds are planted in a special preparation designed to replace the fungus in which Thomas Young, the world’s greatest orchid grower LL the comforts of home are provided in the latest Pullman sleep- ingcars, designed exclusively for overnight travel. There are no upper and lower berths; instead, the car con- tains fourteen luxurious “bedrooms.” Each com- partment is provided with a full-length bed, a folding table and chair, hot and cold water, electric fans, shaded lights, and a full- length mirror! The two photographs give some idea of the comparative spa- ciousness of the rooms. Unlike the old style Pull- man, the new cars are not convertible into day coach- es. Adjoiningcompartments have communicating doors, ordinarily locked, which may be-thrown open for friends traveling together. its prim doubtless pecome & Yes, my | one day ogen singly or haustible tensity of > day the enders of be sto 1s, which page 110)

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40 POPULAR SCIENCE MONTHLY July, i977 Hands The Triumph of Mechanical Skill and Ingenuity in the Wilds of a Desolate Island By HAWTHORNE DANIEL AVED by shipwreck from the hands of the murderous seal poacher, Kiska Joe, four Seattle yachtsmen—Parker, Thornton, Williams and Kelly—were cast up on the deso- late shore of Devil Island in the far northern Aleutian archipelago. With them was Oomak, one of Kiska Joe’s crew of native Aleuts. They found shelter in a cave, killed game for food, and later made tools of steel by smelting ore found on the island. Their attempt to build a boat was interrupted by the unexpected appearance of Kiska Joe’s schooner. Parker, risking the hostility of the poacher, was seized and bound. The others attempted to resist the invader’s armed attack by rolling boulders from a cliff. Just when their plight seemed desperate, a mysterious and dreadful cry echoed through the island. Kiska Joe fled in terror. Later the castaways resumed work on their boat and on an in- genius steam engine to run it. To celebrate the completion of the engine, after many weeks, Oomak prepared a feast. While the men sat at the meal, Oomak, suddenly startled, seized a ladle and flung it into the open doorway. It struck a figure standing in the dark outside. There was a groan, and a body fell across the threshold. It was a woman! Now read on: Oomak cried aloud and retreated to the back of the cave, where he crouched behind the table in terror. For a moment the white men stood motionless, then Thornton stepped forward. He stooped beside the body and drew aside the hair. “An Aleut woman,” he said. “Help me bring her in.” They lifted her gently and laid her on one of the beds, Wy, liams brought water and bathed her face. A bump on her fore. head marked the spot where Oomak’s blow had struck, but the skin was hardly broken. “Stunned,” said Thornton presently. “It’s a good thing th ladle hit the top of the doorway first. Who the deuce is she The woman lay with her eyes shut, breathing lightly. §) was dressed in rabbit skins as they were, and wore moccasiy of sealskin. Her face was wrinkled and old, yet her museculy arms suggested strength and vigor. It was impossible to gues, her age. She was wild in appearance—savage and unkempt— even more so than others of her kind. Yet her face was no unintelligent. Thornton turned to Oomak, who was still crouching in th corner whimpering. “Come here,” ordered the engineer, but the Aleut only crouched more closely against the stone wall of the cave. “Come on, Oomak,” wheedled Thornton. “There’s nothing to be afraid of. She isn’t a spirit or a devil. She’s a live womag, and you just knocked her senseless. Come on, and see if yoy can tell who she is.” ILLIAMS joined in the coaxing, and at last the Aleut crept forward. As his eyes fell upon the face that was lit by the firelight, he started back again. “Tuginana!”’ he cried. The woman stirred, as if she had hear the name. “Do you know her?” asked Thornton. “Tuginana,” repeated Oomak. “She spirit. She dead! Tuginana. Dead—twelve year!” **She’s not dead,” returned Thornton. ‘‘She’s alive, and she’ wake up presently. But who is she, Oomak?”’ “Tuginana,” he said again, drawing back, still half afraid, “She Kiska Joe’s wife!”’ The others stared at him. Kiska Joe’s wife? She who had been reported dead twelve years ago? What was she doing here’ The woman opened her eyes. For half a minute she lay still, then muttered a single word. “Oomak!” “Yes,” agreed Thornton. “He is Qomak, and we are friends,” “Kiska Joe not here?” she asked. “No, he’s not here.” “You not hurt Tuginana?” “No, we won't hurt you.” She made an effort to sit up, and smiled faintly. “I watch you all the time here,” she said. “Nighttime! watch. Daytime I watch. You not hurt Tuginana?”’ Again they reassured her, and Oomak, partly recovered from his fright, began to prepare food for her. “How did you come to this island?” asked Williams. “T live here ten—twelve year,” she replied. * Alone?” “Nobody—just me. In big cave—there.”’ She pointed vaguely. “How did you get here?” She smiled. **Oomak—he know—maybe.”’ But Oomak refused to talk. He pottered over the fire. “Kiska Joe—he think I dead,”’ she said at last. “‘He much *fraid of me.” “What do you mean?” “He keel my child,” she replied. “Knock head on schooner —mad!”’ “‘Kiska Joe killed your child?’’ asked Thornton in surprise recalling the story the Coast Guard officer had toid him. ° E KEEL child—say I keel,’ she explained. “We am schooner. He bury child here.’’ She pointed in th direction of the beach. “I very mad—try keel Kiska Joe,” she went on. “We fight. I fall over rail.”’ “You fell into the water?” “Yes. I fall. Storm make big wave. Schooner sail quick. It go away. I swim.” “You swam ashore?”’ “To this land. Yes, I glad. My boy here. I stay.” “How long ago was that?”’ “T not know. Ten year. Maybe twelve. I not know.’ “Have you seen Kiska Joe since then?” “Yes, I see. I try keel. He run.” “Why did he come back?” “To bring present for dead child. I take. I try keel Kish Joe maybe ten time.” She sm..d and tapped her breast *Kiska Joe he ’fraid of me. He run.” > “But kill ] m3

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July, i977 eds. Wil. 1 her fore. k, but the thing the e is she?” htly. She MOCCasging e to Zuesy nkempt~ € Was not ing in the leut only ive. ’s nothing ve woman, see if you the Aleut hat was lit had heard She dead! , and shel alf afraid, e who had loing here? 1e lay still, -e friends,” ighttime I vered from S. 1e pointed fire. “He much yn schooner in surprise, him. . “We o ted in the a Joe,” she il quick. ft Ow. keel Kisks her breast July, 1927 POPULAR SCIENCE MONTHLY 41 “One steam engine, two steam engine, three steam engine.’”’ Thornton, the engineer, counted off the seconds aloud, while Williams at the helm steered for his milepost. “Why did he run?” “He ’fraid,”’ she repeated. “She spirit. She devil,” muttered Oomak from beside the fire. “That's it,”’ said Thornton to the others. “‘Kiska Joe thought she was dead, so naturally he ran when she came after bim. Conscience.” “Why did you come here tonight?” asked Williams. She smiled. “T come every night—long time. I see you work. What you make?” she asked suddenly. . OU mean, what have we been making?” ——_, “A boat.” “You go away?” “Yes. Before long.” “You take Tuginana?” “Certainly. Where do you want to go?” Her mild features changed suddenly. Her eyes glittered, her teeth clenched. A deep frown cut her forehead. “T go to Kiska Joe—I keel him!” she whispered. “But why did you come so close to us tonight?’’ asked Thorn- ton after a moment. The hard face melted again into a smile, and she looked to where Oomak was cooking fish by the fire. “I smell beans,” she said. ‘‘Not eat beans for long time. Icome close to smell. I think maybe I get some, like I got ham.” “Oh, you took the ham, did you?” asked Thornton. “Did you take the axe, too?” “Yes.” ¥ ~m you made the picture of the bird on the rock?” es.” “What for?” “TI will keel Kiska Joe,”’ she whispered fiercely. “Then that wasn’t meant for us?” “No! No! For Kiska Joe. Not you.” _They saw it all plainly now. “Anybody else would have gone insane,” said Thornton. “But all she has done is to develop a monomania. She wants to kill Kiska Joe, and I can’t say I blame her much. He deserves it. But of course, he’s been afraid, too. He has come here to The craft they had built from raw materials moved steadily through the sea leave offerings to the spirit of his child, and has seen her every time. She rushed at him to try to kill him, and he thought she was dead. No wonder he ran. Anyone would have done the same.” Tuginana, having learned that they were getting ready to leave the island, went back to her cave only to get the axe. She helped Oomak, and made it possible for him to help with the engine. He grew accustomed to her presence, and when he learned that she had been the one who had uttered the frightful shrieks they had heard—the first time because she thought - Kiska Joe had come ashore, and the second time because he actually had come—Oomak began to feel more reassured, for that eliminated one of his devils. Then, when she told them that she had pulled Tuginak’s body into the cave after finding it during the midnight storm that had washed it up—had pulled it in there to learn who it was—Oomak began to feel quite friendly. And when she admitted having taken the axe, the ham, and a number of his smoked rabbits, he decided there was nothing devilish about her, and so permitted her to assist him, and even to do most of his work. CCORDING to their calendar, Tuginana had appeared on the evening of the fourteenth of September. It began to look as if they might be ready to leave the island in two or three more weeks. With their goal so near, the white men labored even harder than they had worked before. The time was approaching when they would put to the test the boat and the engine they had built. Would their handiwork stand the strain of several days at sea? Would they be able to get to some inhabited land before the crude engine wore out or broke down? Would they be able, at last, to set the Coast Guard on Kiska Joe’s trail with the hope that Parker might still be rescued? Or would they find that their friend had been brutally murdered long before? Would the plans that they had worked out miscarry? Or would they manage to succeed? The result was on the knees of the gods, and all the castaways could do was to work and prepare, in an effort to forestall every possible difficulty. For soon they would take their lives in their hands, and set out to sea on the cockleshell that they had built from the raw materials the island had provided. Installing their machinery in the boat proved simpler than

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eas os SS ee x see 4 2 POPULAR SCIENCE MONTHLY Installing the machinery proved simpler than they had expected. They moved the heavy engine on improvised rollers-cut from logs, and th:n hoisted it aboard oa inclined skids they had thought. They moved the heavy engine on improvised rollers cut from logs, and hoisted it aboard along inclined skids. The engine was placed with a boiler on each side, to save space in the little vessel, and so that one man could readily be stoker and engineer. When they had bolted the engine in, Thornton went off to make the propeller and the propeller shaft, while the others connected the boilers, made bricks of clay for the fire boxes and a funnel of steel plates. Sf ocr had whittled out the pattern for the propelier during the evenings of the preceding two months, and prided himself upon its perfection. But the casting was not simple. Still, it was done, and a square hole was cast in the hub for the shaft. October came before the boat was complete and ready for her launching. They took their sealskin of oil aboard, and lavishly oiled their machine. The boat was excessively heavy, and it took them a day to push her down the ways into the water, but at last she was afloat. Williams and Kelly looked her over carefully for leaks, and plugged a dozen. But overnight in the water served to swell the planks and make her tight. Thornton worked over the machinery. He filled the boilers with water, and tightened the spigot throttles and a dozen joints. He got up a little steam and opened the throttles very gently, but was forced to re-time the inlet and exhaust valve. Again he opened the throttles, and the flywheel turned suddenly. He stoked up the fires and opened the throttles wider. The engine ran with a terrific clatter. Groans, clanks, wheezes and weird sounds came from a dozen sources. The vibration was so violent that he was forced to install metal braces from the cylinder to the keel and to the bulkheads—but the engine ran! The nose of the boat was against the clay of the little river’s bank, and the propeller, unable to push the boat ahead, sent a slowly moving stream of foamy water toward the other bank. The group watched with their hearts in their throats. For five minutes Thornton let the engine run, and when he shut it down at last, his companions were too happy to cheer—too de- lighted to do more than go quietly ashore with thankfulness in their hearts. They dug through the sand bar at the mouth of the stream, and loaded their little ship with charcoal and fuel, and with seal- skins of fresh water. During the summer they had caught eight seals. Two of the skins had gone to make the belt that ran the lathe. One served as a container for their oil. Five others were filled with fresh water, four of them for the boilers, the other for drinking. They had eliminated the task of building tanks for their water, and had decided against a condenser as too difficult to construct. They would fill the boilers full of fresh water July, 1977 when they started, and when this the reserve supply in the sealskins ray out, they would use salt water. “But won't that cake in your boilers” asked Williams. Thornton nodded. “Still, we can make it do, and a trig trip will show us how far our fresh water will carry us before we have to turn ty salt.” “How far shall we go on the trial?” “Around the island.” ARLY the next morning they ge out. Oomak and Tuginana wep left behind with instructions to get te gether enough food for the trip, and ty gather up what belongings they wished to take. The engine started, and with Willians at the tiller, they slid noisily dow. stream. They grounded on the sand bar, but got off immediately, and made thei way into the open sea. A heavy swel was running, and until they had gone quarter of a mile offshore they pitched fearfully. Once outside they turned ty the north. Williams, having marked of what he estimated to be a mile, from th mouth of the stream to where a rock rox prominently on the beach, steered fo his milepost while Thornton counted t himself as the boat proceeded. “One steam engine, two steam engine, three steam engine,” he counted aloud. “Four steam engine five steam engine, six—” “What the devil?” asked Kelly of Williams. “He ain’t gon crazy now, has he?’’ “Shut up,” ordered Williams. “He's timing us.” “Timing us? How?” “You try it yourself, sometime. Say ‘one steam engine, tye steam engine, three steam engine.’ and keep it up until you hav counted sixty. Then check yourself up with a watch, and youl find, after a little practice, that you can come within two@ three seconds of a minute every time.” Kelly listened to Thornton as he counted. “Fifty-one steam engine, fifty-two steam engine, fifty-three steam engine,” ani below the engineer felt the bearings of his engine, watched hi water gages, oiled, turned the throttles a trifle, and opened th cast-iron doors to the fire boxes to throw charcoal on the fires *Gee,”’ remarked Kelly, from where he was standing on th bow deck. ‘“‘Ain’t those fires beauties? You can feel the hea from ‘em clear up here. Bright, too, ain’t they now?” “One steam engine, two steam engine, three steam engine} they heard Thornton, still counting. “Four steam engine, five} steam engine—”’ ‘“*Time!”’ shouted Williams. *““Have we made the mile?” roared Thornton. { “Yes. How long did it take?”’ “Ten minutes and five seconds—nearly six miles an how Not so bad,”’ Thornton smiled as he looked out at the two on th deck. .“‘And you know, no engineer will ever admit that a neq engine won’t improve. If this one gets worn in before iti worn out we'll do better than that.” . T WAS roughly twelve miles around the island, and for a pat of the way they ran against a mild current, but having sta within an hour after sunrise, they returned to the creek by tht time the morning was half gone. Ashore again, Thornton went to work at once with forge aml hammer and grindstone to make small repairs and adjustments But they. were almost ready, and three days later, in a sea thal had grown calmer, they lifted their last remaining supplié aboard, took Tuginana and Oomak over the side, and clanks and hisses, slowly made their way down the little stream and out into the smooth, cold sea. With high hopes, the castaways are embarked on thel desperate adventure back to civilization. What does tht treacherous sea hold in store for them? And what of Parke and Kiska Joe? The final installment next month is | with thrills and swift action.

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July, 197 this and Iskins ray - boilers?” nd a trial esh water Oo turn to trial?” | they set ana Were to get to ip, and to ey wished 1 Williams ily down. » sand bar, nade their PaVy swell iad gone a »y pitched turned to marked of >, from the a, rock rose steered for ounted te am engine, 1m engine, ain’t gone ngine, two il you have and youl hin two o -one steam gine,” anf ratched his opened the n the fires ling on the el the heat m engine,” “ngine, five s an hou. . two on the that a new before it’ d for a part ving started reek by the h forge anl 1justments 1 a sea thal ng supplie , and ittle streall d on thei does + of Parke h is | July, 1927 ee ae i peprere (EERPRAT + + at a ih > oi i . et ae Ry e ] ie ~ ihe Hii NY : & “ 5, | FREIGHT PLATFORM : ~ £ y, 4 Se artist pictures here an ingenious / new plan for solving New York City’s traffic problems by a remarkable system of roof-top boulevards running more than sixteen miles in a straight line through the heart of the city. Bridging of cross streets for free movement of traffic; moving platforms for speedy and convenient passenger service; healthful elevated playgrounds for children; under- ground railway freight service—these are some of its outstanding features. The proposed system, conceived by John K. Hencken, a New York engineer, has been approved by a number of emi- A Highway on the New York Engineer Proposes POPULAR SCIENCE MONTHLY ort 4 i & tf 4 = >. % a Z 40 yf he Be oe DET oe ny oi ¥ LEVEL AND BOULEVAR! ~ S. LROOMS, RESTAU AND SHOPS nent engineers and city planners. They say it is entirely feasible from an engi- neering standpoint. It calls for a series of buildings of uniform twelve-story height extending from the lower tip of Man- hattan Island to Yonkers, connected by bridges at all cross streets. Sub-basements would contain four railroad tracks for freight service, as well as conduits and sewers. The first floor, arcaded to form a ten-foot sidewalk, would be devoted to stores and shops. Through the second or main floors, continuous moving platforms for free passenger service would run at graduated Roof ‘Lops 43 speeds ranging from three to twenty miles an hour. These platforms also would be carried on bridges over cross streets. Other lower floors would be occupied by retail shops, restaurants, theaters and soon. The upper floors would be used in business sections for offices; in residential districts for apartments and studios. ; North-bound and south-bound boule- vards on the roof-tops would be separated by a protected parkway, reached by ele- vators. Other elevators, in every block, would carry motor cars from the street level to the elevated boulevards.

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POPULAR SCIENCE MONTHLY Steel cup of the saw. A 14-inch drill bit acts as a pilot for locating the hole and for guiding the saw made with this new tool. In the illustration a plumber is preparing to make a con- nection to the soil pipe in a basement. Another size cuts a neat hole in an auto- mobile instrument board to insert a new instrument or a clock. Movies That “Live” Ayoten pictures that seem to have vivid Electric Hole Saw OU don’t “bore” a hole with the device pictured above—you “saw” it. The device—an odd-shaped circular saw —is inserted on the end of an electric drill, and revolves at high speed, cutting a large, _ round hole through metal or wood. It follows the guiding path of an ordinary twist drill mounted at its center, whose tip projects a trifle beyond the rim of the saw teeth. Unusual holes are easily and quickly KNOW YOUR CAR | | NE of the peculiar things about the ignition system is that it rarely gives warning of | an impending breakdown. Of | course, if the points are becom- ing corroded so that the motor begins to miss, you are being served notice that the points need attention. Ordinarily there is little danger that the condenser or spark coil will break down; consequently it | doesn’t pay to carry an extra | coil or condenser, unless you are going into territory where there are no service stations. Spark plugs do give out at times, so it is always well to carry a couple of spares. Wire and insulating tape also may come in handy. To feel safe about your ignition system, observe the following rules: 1. Inspect the breaker points and the timer mechanism before each long trip. 2. Carry spare spark plugs, wire and tape. 3. Look over the wiring oc- casionally to makesurethat nothing is coming loose. and real depth, with near and far objects standing apart from each other, are ob- tained with a stereoscopic camera in- vented by Harry K. Fairall, of Holly. wood, Cal. The camera’s two lenses, their shutters working simultaneously, make double pictures. One picture is then printed in green and the other in red. Projected on top of each other on the theater screen, they do not quite match, for they were taken from slightly different angles. Wher looking at the twin picture, a two-holed eyepiece with red and green glasses is used. Only one image is there- fore visible to each eye; and the combined effect is as if the eyes themselves, instead of the camera’s lenses, had viewed the original scene. Tests Autoist’s Footwork OW steady is your foot on the acceler- ator or brake pedal? In Germany, the Berlin license officials have devised an ingenious apparatus, pictured below, to test would-be auto drivers. While the applicant responds to commands intended to excite and confuse him, to correspond to emergencies that might arise on the motor highway, asensitive needle registers the steadiness of his foot pressure on an imaginary control. The moving needle gages the foot pressure exerted under varying degrees of excitement July, 1927 It Measures Furnace Heat HERE the blistering heat of flaming furnace is too intense tg permit a man to come near it, this ney hand pyrometer, pictured below, takes its temperature at a safe distance. The operator simply sights through the eye. piece at the open furnace door, presses g button, and a needle on the scale instantly shows the fire’s temperature. The device is for use in steel plants and other places where terrific heats must be known accurately. Within the instry. Simply holding it at a safe distance from a blistering hot furnace measures the heat ment the fire’s heat is focused on a “thermocouple,” two joined strips of unlike metals. As the thermocouple is heated, the tiny quantity of electricity generated is indicated on a dial that in- terprets it as equivalent to so many degrees of temperature in the furnace. Houses of Rammed Earth ? OST soils are perfectly suitable for rammed earth houses, says Dr. H. B. Humphreys of the U. S. Department of Agriculture. He recommends earth that forms in clods when dug, or that, in a footpath, remains hard in wet weather, It is better for the amateur to try his hand at a small building, perhaps a ga rage, first, he says, to practice handling the earth. An ordinary roof and concrete floors make the rammed earth dwelling complete. Anyone who has a plot of ground caa build himself a rammed earth house with his own hands, says Dr. Humphreys The dirt removed in excavating will be more than enough for the walls. Shows When Gas Is Poor OW much heat your gas contaimif can now be measured by a sim calorimeter, or “heat-meter,” devi by Prof. S. W. Parr of the University ¢ Illinois. With it gas companies can in advance the quality of the gas send out, long before complaints the gas does not burn properly mi come pouring in. ; Plugged into the gas supply line, a calorimeter consists of a burner heats running water circulating in metal ‘acket around it. The number degrees that the water rises in temper ture, in passing through the apparatis is read directly on a scale as a measufe of the quality of the gas. still city the gen pare radi ence ness a re\ or a boar devic pend way

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July, 1927 Heat at of itense te this new Ww, takes ice. The the eye- presses a instantly ants and must be e instru. from a 1e heat ed on a strips of couple is lectricity that in- y degrees ‘arth table for 's Dr. partment ds_ earth r that, in weather. > try his IPS @ ga handling concrete dwelling ound cam yuse with mphreys. g will be ng umber tem i pparatis, measure July, 1927 New York’s Storm Detector OWER stations that supply New York City with electricity are now warned of approaching thunderstorms by a new radio device, so that they may prepare for the peak load when lights go on through- out the city as it finds itself in darkness. The thunderstorm detector starts ring- ing a bell at intervals when the storm is still 200 miles away. When the storm is only half an hour’s distance from the city, though the sky may still be clear, the bell rings continuously, and all the generating stations are signaled to pre- are for the increased load. The apparatus used is similar to a radio, but is arranged to record the pres- ence of static rather than discard it. Whitewashes Defy Heat EW whitewashes that can stand heat have recently been announced be- fore the American Chemical Society. To be used in factories where they are ex- posed to high temperatures, the lately discovered compounds, which contain lime, were described as being durable, economical, easy to apply, and capable of giving a brilliant white coat. Several months’ exposure to severe heat, it was said, had not harmed them. The paper on the new whitewashes was read to the Society as part of a sym- posium on lime, directed by Prof. J. R. Withrow, of Ohio State University. Ingenious Combination Tool REMARKABLY versatile power- driven tool, shown below, is being used in German workshops. At its busi- ness end may be attached interchangeably a revolving cutter that bores and trims, or a planer for smoothing the edges of boards. Through a flexible cable, the device is run by an electric motor sus- pended overhead or placed out of the way at the end of the workbench. Connected to an overhead motor, the tool can be used with ease in unusual positions POPULAR SCIENCE MONTHLY Three Lanterns in One! ERE’S an electric signal lantern that, according to the maker, “will never leave you in the dark,” for it has three lights instead of one. Up-end it, press a switch, and from a bulb concealed in a reflector in the base a powerful spot light will beam forth. For signaling, a broader beam comes from a bulb near the rim, and a red light shines from the side. It was designed especially for railroad men. To save the battery, the switch turns off the spotlight when the signal light goes on, and vice versa. The red side light is independent of the other two. Gold Plucked from Air NCLE SAM is literally picking gold out of the air through a device in the U. S. Assay Office, New York City, which recovers metal that formerly went up in fumes from the smelting of bar gold. Six hundred ounces of gold, valued at $12,400, have thus far been recovered from the dust. Driven up the stack by a giant fan, the gold-bearing fumes from the furnaces pass between two metal plates charged with high voltage electricity. Gold parti- cies suspended in the gases become electri- fied and settle on the electrodes, whence they fall or are shaken into a collecting chamber below. A Triple-Purpose War Plane oe. torpedo plane and scouting machine, the latest naval airplane, pictured above, is a “triple threat” indeed. Tested recently at Anacostia, D. C., it carries its pilot and observer in protected cockpits below the wing, while a machine gunner at the rear pours a withering fire upon enemy planes. With a touch of his control, the observer can loose a death-dealing bomb from beneath the fuselage or launch a torpedo as the plane darts toward a hostile warship. How Much Do You Know of the World You Live In? EST yourself with the twelve questions below, selected from hundreds sent in by our readers. For the correct answers turn to page 135. 1. What is the only active volca- no in the continental United States? 2. What is the longest river in the world?. 3. How were the Aleutian Is- lands formed? 4. Where did prehistoric people build stone apartment houses? 5. Wheredosponges come from? 6. Where is Portuguese spoken in America? 7. Where is the “Blarney Stone’’? 8. What animal keeps African rivers from being choked? 9. Where was writing invented? 10. What is the highest moun- tain in the world? 11. What islands have the fewest insects? 12. Where are there clams large enough to kill a man?

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POPULAR SCIENCE MONTHLY . nocd : en | . i OS | Tf VELA I) } She Makes Bike Tires AKING tires for racing bicycles is the unusual specialty of Mrs. Ernie Pye, of Newark, N. J. Her late husband, a star cyclist, who had perfected a special tire for racing, left her his patents for the process. Now Mrs. Pye herself manu- factures the tires at her Newark shop. Each one is made to order for her customer; she numbers in her clientele virtually all American racing cyclists, professional and amateur. Some riders want heavier tires than others, some a trifle larger or smaller, according to the kind of race in which they are to be used. Whatever their needs, Mrs. Pye tries to fill them. Seven tiers of woven thread, with al- ternate layers of shellac, go into the tread. The inner tube is made of extremely thin Para rubber. Large drums support the embryo tires during the weaving operation. World’s Biggest Vacuum Tube HE largest vacuum tube ever made for radio broadcasting, with a power of 100 kilowatts, was recently installed by the General Electric Company at its sta- tion WGY in Schenectady, N. Y. Seven and a half feet high, the giant tube weighs a hundred pounds. Its tungsten filament is as thick as a lead pencil, and a water jacket of copper tubing keeps it from overheating. Used to am- plify the output of a husky twenty-kilowatt tube, the new monster will hurl a radio wave of unheard-of power to aid in transmission experiments. New Auto Motor OTOR fuel costs can be cut to five cents a gallon, claims Walter S. Rohn, consult- ing engineer, of Needham, Mass., with an amazing new automo- bile motor he has invented that has no spark plugs nor connect- ing rods. Like the huge Diesel engines used to propel ships, it will burn low-grade oil instead of gasoline. An odd-shaped cam on the crankshaft receives power directly from a roller mounted on the piston. Heat gen- erated by terrific compression ignites the fuel mixture in a “slow” explosion. Blocks Improve Acoustics Hoe for better acoustics in large halls and theaters is held out by the per- fection of new concrete building blocks, the latest contribution of Emile Berliner, inventor of the microphone, disk phono- graph records and other devices. Berliner’s new blocks are described as W.S. Rohn, Massachusetts engineer, with the plans for the new auto motor he has patented. Heat generated by compression ignites the low-grade oil that it burns in place of gasoline July, 197 having all the acoustic properties of wood, In the illustration, the inventor is testj with a tuning fork the sound qualities gf the blocks installed in the assembly hal} of a school in Washington, D. C. Once place of extremely bad acoustics, it is noy said to make a child’s voice audible seventy-five feet away. Paper from Old Dollar Bills ORN-OUT dollar bills will yy longer be a loss, but a source of profit to the Government. As a result of experiments by Government experts, g way has been found to convert the fou tons of condemned bills returned each day to Washington for destruction intg fine writing paper. With new machinery, the colored ink is now removed from the bills, so that the resultant pulp is of a quality suited for a first-class grade of stationery, Hitherto the bills destroyed have pro. duced only a worthless pulp, which was sold to souvenir makers. Furnace Feeds Itself ECHANICAL hands tend you heating plant in a new domestic furnace recently exhibited in New York Coal fed from an automatic hopper out side the furnace is distributed in the fire by a revolving grate. Set a contrd lever at hot, medium or low, and you can go away and let the furnace stoke itself, A Table of 51,000 Parts ROM all over the world came the 51,000 bits of wood with which George L. Hathaway, of Cincinnati, Ohio, con structed the remarkable inlaid chess table below. Among them are fragments from the famous chestnut tree at Cambridge, Mass., beneath which the “‘villag smithy” stood; a rare piece of African cork; and a piece of the first navel orange tree imported from Spain a century ago These and the others Hathaway whit tled into shape with a_ pocketknile, trimmed with a handsaw, and laboriously glued in place. He traveled 13,000 miles to collect his material. George L. Hathaway at work on the amazing chess table whose construction took 41 month - a a eee tee ee ae | ee Be te Pe ee. ie, ek | See rf mst LY S343 hor &

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July, 1977 s of wood, is testin ualities of mbly hall py Once a , it is now e audible r Bills will no source of a result of experts, a t the four rned each ction into slored ink s, SO that ity suited tationery, have pro. which was self end your ~ domestic New York, ypper out od in the a control 1d you can -oke itself, Parts came the ich George Ohio, con- chess table 1ents from ‘am bridge, ** village of African vel orange ntury ago. way whit- »cketknile, aboriously 3,000 miles the amazing k 41 month July, 1927 Cutting Steel with Iron {~ MAY seem surprising that it is I ssible to cut a bar of steel, even of the hardest tool material, with a smooth disk of soft iron—and yet it can actually bedone. The iron disk, slightly roughened at its periphery, is rotated at high speed, so that any point of the periphery travels at least 300 feet a second. If a steel bar js pressed against the rotating edge of the disk, the friction will transform a great amount of energy into heat, which melts the steel. The greater part of the molten steel is thrown off by the centrifugal force of the rotating disk in the form of a shower of brilliant sparks, but a small part becomes welded to the cutting edge of the disk. The disk, contrary to what one might expect, does not become ex- cessively hot, because it is cooled by its rapid motion through the air. To Cross Ocean in Sailboat N A twenty-foot sail- boat, Paul Muller, of Berlin, Germany, plans soon to cross the Atlan- tic. After twenty years as a convict, he intends to start life over again in South America; heshould reach its shores, he esti- mates, after three months on the water, though he will have only a compass toguide him. Despite the factthat Mullerhasnever been to sea in all his forty- one years, he steadfastly refuses to believe that his hazardous voyage may end in disaster. POPULAR SCIENCE MONTHLY 47 German ex-convict and the tiny craft in which, with only a com- pass to guide him, he plans to cross the ocean, to start life anew Lumberman Models Forest Creatures in Wood a Ps ee. HESE amazingly lifelike models of wild creatures were carved out of solid wood by Alfred La Clair, lumber- man, of Biddeford, Maine. The only tool that he used was an ordinary jackknife. One outstanding example of La Clair’s ingenuity is the figure of a bear, now placed on a roadside near Black Lake, Canada. This was hewn out of a solid tree trunk with an axe, then finished with the knife. He “Clocks” the Big Races Ww racing automobiles come hurtling around the speed- way on the home stretch, the man at the finish line must have remarkably keen eyes to pick the winner. This is the difficult job of Odis A. Porter, of Indianapolis, Ind. Timer of big auto races, he shares with his unique time- registering device, shown in the illustration, the distinction of being the only timing combination in the United States approved by the In- ternational Aeronautical Federation, world governing body of air racing. French Build “Ghost”? Plane NVISIBLE and silent in the darkness of night, an amazing plane being de- veloped by the French aviation service may be a new terror in future warfare. Equipped with newly designed silencers for the engine, such a plane, it is said, has flown unheard at a height. of only 300 feet from the ground. A special paint on the wings and body merges the plane with the dark night sky, hiding it com- pletely from observers only a few hun- dred feet away. Silence and invisibility would add im- measurably to the death-dealing powers of airplanes, according to experts, espe- cially for night attacks. During the World War the purring of planes was usually sufficient to get the enemy defense guns into action. “Mystery” Burglar Alarm O WIRES or visible electrical connec- tions betray the presence of an amaz- ing new type of burglar alarm invented by a young French engineer. A field of radio waves is set up in the room to be protected, and the apparatus is adjusted until the electric circuit is in a state of equilibrium. As a burglar steps into the room, the slight disturbance the mere presence of his body makes in the charged room is enough to unbalance the electric circuit and ring a gong that gives the alarm. After a number of tests, the apparatus has been installed in Paris to protect valuable state papers at the Spanish embassy.

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“Taxis” Old and New in ¥ POPULAR SCIENCE MONTHLY the Sahara R many years the sole recourse of desert travelers, the camel is at last finding a rival in the tractor automobile. The photograph shows the tentlike cabin or “bussoura,”’ age-old device carried on the camel’s back to protect the traveler against the blistering heat of a protracted march. Near by are two fleet automobiles of the French military transport service, equipped with special caterpillar treads, which are regularly engaged in making trips across the rapidly shifting sands of the Sahara desert. Ice Lowers 16-Ton Floor UNSHINE and ice took the place of jacks in a recent unique engineering feat at St. Petersburg, Fla.; when a six- teen-ton concrete slab, the floor of a pier bandstand, had to be lowered. ‘Desiring to drop it from its two-foot height above the pier to a height of six inches, engineers found their screw jacks too bulky for the job. They therefore raised the floor slightly. and set thirty-two fifty-pound cakes of ice under it, meanwhile arrang- ing the new underpinning. As the ice melted in the brilliant sunshine, the floor settled gradually and successfully to its new foundation. Is Quiet Necessary for Good Golf? ORNS, whistles and tin pans sounded lustily during a unique golf tour- nament recently held at Atlanta, Ga. Women golfers who participated sought to prove that the quiet demanded by men players was unnecessary for the game, if the players exercise proper mental con- centration. As each player made a stroke, spectators hooted and cat-called in efforts to distract her attention. Another novel feature of the tournament was that each member had to play the entire course with a single club, selected at random from the bag. WHEN You BRUsH your teeth, allow the lather to remain on a little time before rinsing, to heighten the germicidal effect, advises the U. S. Army Medical Corps. The ordinary soap contained in most prep- arations for the teeth is said to be a valuable antiseptic. ; Armor for Matador’s Horse PAIN’S famous bull fights are becom- ing more humane and less gory—for horses, at least. To guard against the horns of a charging bull, the matador’s mount must now wear padded armor like that illustrated above. The matador still must shift for himself. July, 1927 Salt Lake Changes into Fresh GRICULTURE in the vicinity o Honolulu, Hawaii, has played ap interesting part in the novel phenomenog of turning a salt lake into a fresh-water lake. Originally connected with the seg by an underground passage, the volcanie lake crater of Salt Lake was lined with hundreds of tons of salt where evapora. tion had occurred. When great areas near by were recently plowed for sugar cane, rain and irrigation carried silt intg the lake and plugged the sea opening, Now fresh-water streams have washed away the salt and the former salt lake jg a reservoir. To Remove Unwanted Grass RASS or weeds growing on garden walks or other places where they are not desired, can be removed easily and quickly by scattering a few handfuls of finely crushed ferrous sulphate of iron, commercially known as green vitriol, over the spots, and then about half that much of powdered potassium chlorate. Sprinkle the dusted area with water and await results. !In the presence of moisture and atmospheric oxygen, the ferrous sulphate is oxidized to ferric sulphate, which gradually changes to iron oxide, releasing the sulphuric acid with which it was combined. This acid is in itself highly destructive to vegeta tion, and its effect is increased materially by the chlorine generated by the reaction of the acid with the potassium chlorate, Brushes from Chinese Pigs OGS don’t remind most people of paint brushes, yet they furnish the bristles for hundreds of thousands of them. The finest bristles for the best brushes come from the pigs in China. The Chinese workmen grade the _ bristles according to stiffness, elasticity and flexibility, and also sort them _ into lengths. The bristles of each length ar tied up in small bundles, the root end turned in one direction and the split end in the other. The root end is bound into the ferrule of the brush and the split end spreads the paint or varnish. i= gS Does noise disturb the golfer? These women put that convention of the links to the test

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July, 1977 into icinity of layed an enomenon esh-water h the sea e volcanic ined with - evapora. eat areas for sugar 1 silt inte - Opening, e washed alt lake ig Grass m garden here they ved easily r handfuls te of iron, en vitriol, ibout half potassium isted area ts. 'In the mospherie ; oxidized ly changes huric acid This acid to vegeta materially e reaction chlorate, e Pigs people of irnish the ls of them, t brushes na. The >» bristles icity and 1em__ into length are root end » split end ound inte the split sh. test July, 1927 Science Explains “Bloody Rains”’ “QCHOWERS of blood,” the terror of people of ancient times, are no longer a mystery to science. When such a shower of red rain fell a few weeks ago in southern France, microscopic exami- nation of the “bloody drops’ showed them to contain colored dust blown across the Mediterranean from the Sahara. Volcanic eruptions, and possibly mete- oric dust from shooting stars, have at other times produced colored raindrops. Sometimes the fluid deposited by certain butterflies just before they take flight for the first time leaves a “bloody rain,” of red drops spattered over rocks and earth. Vari-colored rains have been recorded, from white, due to chalky earth, to “ink,” due to smoke or soot. “Yellow rain,” not infrequent in the United States, has been traced to pine tree pollen. Other “miraculous” showers—of fish and frogs, for instance—have actually occurred when tornadoes or waterspouts over shallow water and sucked them aloft. But on at least one occasion a reported rain of frogs was traced to tor- rential rains that washed away a muddy layer of earth and exposed a vast number of frogs that had lain buried in the ooze. Stomach Can Be Photographed CIENCE at last has found a way to photograph the inside of the stomach, according to reports from Germany. A tiny camera containing seven films is in- serted directly into the stomach on the end of a tube. It takes a complete set of pictures of the stomach’s actions in fourteen seconds’ time. The operation is said to be entirely painless, and the re- sults obtained much more satisfactory than X-ray pictures. Test Machines in Padded Cell HE strangest “padded cell” in the world has just been completed at Manchester, England. Not intended for human occupancy, it is being used by an electric company to test to the breaking point high-speed machinery. Cushioned walls of reinforced concrete nine feet thick protect observers from flywheels and other machine parts that are likely to fly apart under terrific speed. Tele- scopes and fast camera lenses peer POPULAR SCIENCE MONTHLY through holes in the wall to watch the tests. Without such a “cell,” these unique tests would be prohibited by their dan- ger. The twenty-ton rotor of a great generator, for instance, spin- ning 3,000 times a minute—a not unusual speed in practice— could loose as much destructive energy as that of a head-on col- lision between two ten-car railroad trains speeding at forty miles an hour! 3 s — ; ‘ ; ete 4 “ a - as es . + f - 5 alter es — 4 s d { = miei : teh * a. ; ? Ship Plastered with Oysters F YOU'VE ever wondered what a ship must look like after it has lain at the sea’s bottom for several years, the photo- graph above will give you a good idea. Raised from the bottom of Chesapeake Bay after seven years beneath the waves, the S. S. Wotan was found to be a first- class oyster bed! Thousands of oysters covered every exposed inch, including the propeller. The photograph shows how the bivalves had to be scraped off with long poles when the ship was brought into dry dock at Baltimore, Md. Wells, the King’s ranger, corners part of the herd and selects a fine deer 49 The end of a thrilling loop— the car speeds down an incline, shoots off at an angle, turns a loop and then lands upright Loops the Loop in Auto EARING down an inclined runway in his acrobatic car and looping the loop at the end of it is an everyday affair for Sieg, German daredevil. He has put guide wheels on the back of his motorless car to flip him off at the right angle. Deaths from Heart Disease ONTRARY to popular belief, death from heart disease seidom occurs sud- denly, according to a recent statement by Dr. 'T. Stuart Hart, New York specialist. Most types of heart disease, he says, re- sult in prolonged, gradually increasing in- validism before death; the types of heart disease in which death may come abruptly form a very small group compared with the type from which the great majority of patients suffer. Theater Teaches Traffic Laws A expressly for motorists and pedestrians, with six free per- formances daily, is being run by the police of Frankfort-on-Main, Germany, to in- struct the public in traffic laws. The stage represents an avenue with several street crossings, complete with sidewalks and lamp posts. Automobiles, horses and wagons, pedestrians, even a nurse with a baby carriage, perform their parts in the drama. Every imaginable violation of the law is portrayed, with police and chaffeurs indulging in instructive repartee. Staging a Deer Rodeo OMETHING unusual in the way of rodeos occurred the other day in England, when Sir Henry Dering staged a round-up of the 400 deer on his Ash- ford, Kent, estate. Under the direction of Wells, the King’s head ranger, more than fifty deer were selected and sent all over the country, to bring new blood into existing herds. In the illustration, Wells has just slipped from his horse to capture a fine deer by the hind leg. A RECORD ocean depth of 34,416 feet, more than six and a half miles, has just been discovered by the cruiser Emden between Japan and the Dutch East Indies, the German Admiralty announces. The former record was 32,644 feet, off Japan.

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50 POPULAR SCIENCE MONTHLY Suly, 199 Wa Oud Produce Fighting Fire with Soap Suds Coupe-Motorcycle, Fake Pear| = | Detector and Other Novelties ae Comparison of finger prints is made easier for Los Angeles police by this new device, called a ‘‘com- parograph.”’ The observer, looking into the hood, sees the two specimen prints, illuminated, en- larged and apparently placed on top of each other. The lines merge if the finger prints are identi- cal, or quickly show up differences in formation Ultra-violet rays from a new quartz lamp designed for jewelers reveal imi- tation pearls with startling clearness, making the artificial gems appear shab- by by contrast with real ones. The German inventor calls his device the “lucidoscope.”’ It has a special holder to grasp the gems, as shown above Banking by a chute is the novel con- venience provided for after-hour de- positors by a Cicero, Ill., bank. The chute is built into the bank walls, and deposits are made from the street as Here’s how Harry Dorer, of Newark, N. J., shown at the upper right. In addition keeps the heat from interfering with summer to ordinary burglar alarms, the 35-ton painting jobs around his house. He attaches vault door has a sensitive sound wave a fan to a portable scaffold fastened to his relay device that starts an alarm going belt, and suspends it over his head so that the at the slightest noise. Even the clap- breeze blows directly on his face. Current is ping of hands, as the cashier is demon- supplied from an electric socket in the house strating at the right, sets off the alarm Red and white lights flashing along the keyboard, instead notes on a printed page, tead pupils to play the piano in latest method of teaching. Th pupils’ keyboard has miniatut electric lamps behind its key, all controlled by. the teacher’ piano. When she strikes a chord, corresponding lamps light on the pupils’ keyboard. method is said to be mud speedier than the usual labot ous way of learning the no@

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Suly, 1997 POPULAR SCIENCE MONTHLY 51 site: 1927 Cts} of Lnventive Suds, Pear| vel ties Pi * Music has healing powers, believes Huston Ray, concert pianist, and to utilize them he has developed a remarkable apparatus. He takes music from a radio receiver, phono- graph, or piano, transforms it first into elec- trical waves, and then applies the radiations directly to the patient through curious disk- like reflectors. He is shown above giving a demonstration in New York, and at the left with some of his sound wave apparatus Now the swimmer can wear a belt which, in i emergency, becomes a life buoy; or the ocean traveler may wear a life \ preserver constantly and no one be the wiser. George Waimel, of Kitch- When this vehicle comes to a ener, Ont., Canada, has stop, it has four wheels. Under invented the device, 1 way, the two small wheels at the which lies flat against j sides fold up and the machine the body, as shown in becomes a motorcycle. A French upper view at left. By a inventor’s answer to the high turn of a screw, a glass i cost of gasoline, it is designed to | provide automobile comfort for | two passengers despite its small j size. Foot pedals regulate the { motor, while the steering is | done with a pair of handlebars container within, holding compressed gas, is brok- en, inflating the belt ights flashing rd, instead d page, tead . piano in th eaching. Th has miniatut nind its keys the teacher’ trikes a chord, , nps light @ Soap suds are used to fight fires by Germany’s latest fire- yboard. Ti fighting machine. Particularly useful in smothering gasoline ; . : j : to be mud or benzine fires, where streams of water would be useless, Giants all—here we have, in one picture, the biggest crane afloat, the world’s usual labot this machine carries two large foam generators, filled with largest floating dock (at Southampton, England), and, in the background, the ing the note powdered soap. High-pressure jets of water race through S. S. Berengaria! The huge crane bears no resemblance to the conventional the soap chamber, operating water wheels that churn the boom. It is hinged at one side, and ponderous pistons slide vertically to raise or soap into suds, to issue in a foamy blast from the hoze nozzle lower ‘t. Hoisting the heavy machinery of the Berengaria is child’s play for it

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52 POPULAR SCIENCE MONTHLY ‘' $Scisiccagl aa sal Srtere, nt. tty eee oe Lessens Movie Film Breakage ACKED with a thin strip of brass, as pictured above, a new movie film passes through the projecting machine with considerably lessened danger of breakage. Holes cut in the metal, instead of in the film, are engaged by the cog- wheels that advance it. Thus the fragile strip is relieved of strain; moreover, the cogs cannot become clogged with shreds of film emulsion, as often happens with standard film. According to the inventor, Arthur Price, of Freeport, N. Y., the new film will be particularly useful for the miniature automatic projectors used in show window advertising, since it will run indefinitely without attention. Machine Tests Boxer’s Punch SPARRING partner that can’t be knocked out and yet tells accurately the strength behind each punch, is pro- vided boxers in a novel electrical machine, pictured at the right. Perfected in Berlin for testing the punching ability of prize fighters, it substitutes a sturdy and un- feeling electrical apparatus for the body of the boxer’s opponent. Gyroscope for Giant Yacht ALLED the world’s largest motor yacht, a 294-foot vessel now being built at Wilmington, Delaware, will have a huge gyroscope—a monster replica of a child’s balancing top—just forward of the powerful Diesel engines, as an anti-roll de- vice. The spinning twenty-ton wheel is expected to keep the yacht on a steady keel in rough seas Our First Ocean Air Liner? IRPLANE, ocean liner, and dirigible are rolled into one in an amazing design for the latest proposed trans- Atlantic craft. It is called the “aero- ship-plane”’ by its inventors, three New York engineers. It is driven by two giant propellers, while helium-filled cubicles and planelike fins support it aloft. If necessary, it could descend to ride upon the waves. Its speed is estimated at ninety miles an hour in the air, and that of a liner in the water. A hundred and twenty feet long, the craft would accommodate thirty pas- sengers, while a crew of only four men would man the simplified controls. Gyro- scopes within the envelope, it is said, will enable the craft to hover motionless in mid-air in stormy weather. Its inventors hope before many months to complete the first of these strange ships. Testing his punch. The apparatus records elec- trically the force behind each blow delivered July, 197 Music Sets Off Powerful Explosive USIC-MADE explosions marked an unusual test made upon iodide of nitrogen, one of the most powerfyl explosives. Known to be more gy. ceptible to some vibration rates thant others, the explosive’s critical point was discovered by rubbing some of it on the strings of a bass viol. Each of these strings, the investigators knew, could vibrate only at a certain rate that cor. responded to its musical note. One after another the strings were set in vibration by playing the same note on another bass viol in the room. Though nothing hap. pened when the E-string was sounded, the G-string caused a detonation. The vibration rate to which the powder was most sensitive was determined as 60 per second. “Smell-Meter” to Fight Bugs N OLFACTOMETER, or “smell. meter,” is the latest instrument devised by the U. S. Bureau of Ento. mology to aid in its war against injurious insects. By its use the bug and beetle ex. perts hope to find what odors lure certain harmful insects most strongly. From the facts thus learned, powerful artificial scents will be developed that will attract swarms of the pests to places where they can be destroyed. Don’t Listen with Your Eyes URN on the radio and shut you eyes, is the advice of the Massachu- setts State Board of Optometry. In a simple set of eye-saving rules, it is pointed out that eye muscles and nerves are sub- jected to a greater strain than any other part of the body. To rest them, as well as to avoid distracting sights, close the eyes when listening to a concert or speaker. And when you read at night, shut your eyes for two minutes at the end of every twenty pages. Find Mummy in Ohio Cave lg age need not go to Egypt to dig up archaeological treasures, as witness the find of a party of Boy Scouts near Lancaster, Ohio. In a hidden cave the young explorers came upon a mum- my, wrapped in woven reeds. Taken to the Ohio State Archaeological Museum at Lancaster, it was judged by C. H. Shetrone, curator, a discovery of con- siderable importance. Relics found with it indicated that it was the mummy of an Indian princess. Tobacco Chemically Made YNTHETIC tobacco is the latest “substitute” produced in Germany. Thin sheets of prepared paper are impreg- nated with chemically made nicotine. Dyed and perfumed to resemble real to- bacco, they are then made into cigars. Mine workers endure the heat in the shafts more easily when salt is added to their drinking water, it has been found. Excessive perspiration causes a loss. 0 salt from the body, and replacing this loss prevents much of the exhaustion that would otherwise result. iT

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July, 197 erful $ marked pon iodide L powerfyl more us. tes _thanto point was f it on the 1 of these ew, could that cor. One after 1 vibration other bass thing hap. 3; sounded, tion. The owder was | as 60 per it Bugs or “smell. instrument | of Ento- t injurious | beetle ex. ure Certain ly. From il artificial vill attract where they ur Eyes shut your Massachu- try. Ina t is pointed es are sub- any other m, as well , close the -oncert or | at night, tes at the o Cave o Egypt to -“aSUTes, as Boy Scouts idden cave yn a mum- Taken to 1 Museum by C. H. ry of con- found with mmy of an Made the latest Germany. ure impreg- » nicotine. ble real to- > cigars. eat in the s added to een found. a loss. of lacing this ustion that july, 1927 POPULAR SCIENCE MONTHLY a NEXT MONTH! ha epic of the automobile—how, jn One amazing quarter-century, we became a nation on wheels, with one auto to every three adults—the strug- | les, failures, triumphs, of the first | makers—all these you'll find in “Whirling Wheels” By EDMUND M. LITTELL —an absorbing new novel beginning in next month’s issue. Both as a picture of the development of the automobile and a fascinating story, you'll enjoy it. Germans Have Flying Yacht APABLE of flying as well as sailing, an amazing yacht marketed by a German airplane concern can even “taxi” out of the water up on land. Spectators at a recent test saw the crew of the schoonerlike craft transform it into an airplane and fly away. The duralumin masts are demountable for flying, and besides its conventional sails and anchors the yacht has all the necessary aviation instruments. Under the wings are placed removable wheels for climbing to land from the water. All-metal construction minimizes the fire hazard. Industry Now Uses Garnet ARNET, the red -stone formerly so popular as a jewel, is today a valu- able aid in several industries. For rough grinding, garnet paper somewhat re- sembling sandpaper is made by coating sheets with broken fragments of the stone. Harder than glass or quartz, it has the added advantage of breaking up irreg- ularly, always leaving sharp edges ex- posed. Chips of garnet are often used in inexpensive watches as bearings, instead of the sapphires and rubies required in higher-priced timepieces. Puncture Vine Spreads East EWARE of the puncture vine, the sharp-spined burs of which can easily pierce the tread of an automobile tire! Known in California for years, this curious weed has recently spread as far eastward as Illinois, its seeds carried imbedded in the wheels of motor cars. In Kings County, Calif., drastic methods, including spraying the roadsides with oil, have been adopted by Wallace Sullivan, county agent, to eradicate the pest. OnE DISADVANTAGE of insulin, hailed as a remedy for diabetes, is that it cannot be given in the form of drops, powders or tablets, but must be injected under the skin. Investigators, under Prof. J. C. Minkowski of the University at Breslau, Germany, have produced a substitute for the pancreatic insulin, found effective in a number of cases, which can be given to the patients in capsules. [Seen : = Test of new device to prevent railroad accidents. Rollers for Grade Crossings EVOLVING rollers, spinning back- ward under a car that tried to ride forward over them, would hold the car practically stationary, though its own wheels might be turning at top speed. This fact is utilized in the latest scheme to prevent accidents at railroad crossings, proposed by Charles Burnett, of Wash- ington Court House, Ohio. Sunk in the pavement, the rollers would extend all the way across the road (the illustration’ shows a small model used for testing). By means of an electric control, they could be locked or released. At the approach of a train, the rollers would automatically be released. De- prived of its tractive power, an auto upon reaching them would come to a stop with its wheels futilely spinning. Not until the passing train tripped the locking switch as it passed out of the danger zone could the car proceed. RARE ncis, saalbso et ‘ The universal adjustment on this vise enables work of awkward or unusual shape to be held upright “Eraser Key” Aids Typists Fg typewriter can now be equipped with an “eraser key”’ or “eraser lever’’ which makes the erasing of errors on single copies easy, neat and automatic, according to two Californians who have invented the device. To erase the letter or letters, simply press the lever or key. This thrusts a sharp-edged renewable eraser forward and upward against the platen, to take out one letter at a time. In the picture the eraser key is placed at the right. When attached, the eraser op- erates as though it were an original part of the machine’s mechanism. Vise Holds at Any Arigle WIST the vise pictured at the left to any angle you want, says the maker— and it will stay put. Locked with a spe- cial lever, it is said to be so rigid that even oil poured over the ball of the universal joint won’t make it slip. Another ad- vantage—instead of working in a cramped position, the user can turn the vise to hold the work at the most convenient angle. In the illustration a machinist is using it to hold a metal fork in an upright position while he is working on it. The locking lever is seen just above the metal ball that supports the vise.

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54 POPULAR SCIENCE MONTHLY The students pictured at the right can well afford to look serious, for they are—literally—about to take ee poison! To learn new facts about certain drugs and © poisons, Dr. Linn J. Boyd of Flower Hospital, N. Y., ; : recently administered mild doses to fifty volunteers. fe a Their symptoms were then carefully charted. The doses, of course, were harmless, and for purposes of = iad ww comparison some students unwittingly received pills * a which contained nothing more than milk and water d > iv Explorers of Science The “new music” of our mechanical era had its first American hearing not long ago, when George Antheil, composer, startled a New York audience with his “ Ballet Mecanique.”’ Antheil’s idea is to interpret our industrial age by means of such instruments as electric bells, air- plane propellers, auto horns, anvils, torpedoes, screw drivers, police whistles, repeating alarm clocks and so on. The New York audience survived the performance. The young composer is shown above with some of his instruments When any exploring is to be done in the Arctic, ten to one Capt. Robert A. Bartlett and his schooner, the Morrissey, will be called upon. Captain Bob commanded the ship Peary used in 1909 when he reached the North Pole Science can now say definitely that a noisy office makes a typist less efficient. Curious apparatus was used to prove this, in experiments conducted recently by Dr. Donald A. Laird, psychologist, at Colgate University. A noise-making machine (pictured at right) rang bells and produced all the clatter that might conceivably occur in the noisiest of offices. Meanwhile the typist went about her work, while an apparatus like a gas mask (above) analyzed her bodily reactions to the disturbing sounds and measured the wasted energy. In this photograph note the background made up of panels of sugar cane fiber, which, when in place, reduced the noise by fifty percent

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55 POPULAR SCIENCE MONTHLY —a—. be er ‘ + se bea Languages of all races of the world will be preserved : ‘ ae on phonograph records for posterity, when a unique ; : collection being made for the new Museum of 4 @ j i Languages at the Sorbonne, Paris, is completed. ee: ig The photo at the left shows a Ukrainian making a £ ! i ‘ i : record of a song in his native tongue. Careful selection . } 4 4 ; = is made of the persons whose voices are recorded, so that the records preserved may be absolutely authentic Men Who Are Doing the Unusual in New Fields of Experiment—P otsons, e Office Noises, Auto Seats, Tested; Recording Languages for Posterity Exploring the ocean’s bottom is possible for anyone who can make a diving helmet like the one above, the creation of Carl Breuer, Princeton University student. Breuer tested it out first in a swimming pool, and then took it with him on a trip to Bermuda to collect coral specimens There’s no chance that radio station ‘‘2-EB” will inter- fere with broadcasting pro- grams. Boyd Phelps, of Jamaica, N. Y., rigged up this unique station at his home to transmit signals on the remarkably low wave length of five meters. (Left) Boyd testing the wave lengths of the transmitter rt A. in the station at home. (In he circle) The portable motor- ole truck station in which he tours the country to test the range of his signals Ever wonder how the amaz- ing glass apparatus chemists use was made? Here’s how it’s done at the U.S. Bureau of Standards, by O. E. Sperling, chief glass blower, shown here shaping the last tube of an intricate device (Right) Bumpless and slide- less auto seats may be de- vised as a result of tests by Bureau of Standards experts with a unique apparatus that measures jolts that occur in riding over rough highways

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Wheel of Seven Sad Sounds fees the late Emperor of Japan was borne to his last resting place, the coffin, in accordance with ancient custom, was carried in a unique hearse with wheels specially constructed to emit the famous “seven melancholy sounds.” These are simply seven different creaks, produced in unison at each revo- lution by the friction of the wooden parts of which the wheels are made. Ingenious joinery is required in the construction. One of the wheels is pictured above. Falling Meteor Misses Cyclist — a falling meteor, visible all over England, whizzed through the air like a bluish rocket one night a few weeks ago, one person saw it land. Reginald Harvey was cycling through Oxfordshire when “a ball of fire the size of a coconut” shot past him, whistling, and hit the road twenty feet ahead. Only gray ashes, strewn about the ground, re- mained of it. As far as known, no meteor ever killed a man; Harvey probably had the narrowest escape on record. Male Birds Hatch Eggs HE males keep house among the rare Arctic surf birds, recent discoveries have revealed. Though this bird has been known to science for 150 years, the first nest and eggs were found only recently on Mt. McKinley, Alaska. From the bird’s breeding habits, it is now known that not only does the father bird hatch the eggs, but he defends them far more valiantly than does the female. Are You Planning to Buy | an Oil Burner? AS A result of its investigation of 3,343 oil burner installa- tions, the Popular Science Institute of Standards is prepared to assist readers planning to install this type of heating equipment. Advice on selection and installation to meet your weeds will be sent, providing the following information is sup- plied: (a) Number of rooms in house; (b) Type of heating system; (c) Annual coal consumption; (d) Gas or electricity installed. No charge will be made for this service. Address your letter: Oil Burner Service, Srovter Science Institute, 250 Fourth Avenue, New York City. EE Girl Daredevil Rivals Men WINGING clear of a speeding auto- mobile as she grasped the perilous rope ladder suspended from a plane above, Mabel Cody, girl daredevil, made spectators at Daytona Beach, Fla., gasp the other day as she per- formed the feat pic- tured at the right. Both car and plane were whizzing over the sand at something like a mile-a-minute clip at the moment Miss Cody made her hazardous hop. The ladder was pulled in by a hanging rope from above. POPULAR SCIENCE MONTHLY You Can’t Tell ’Em Apart HOUGH appearances are against it, the remarkable photograph at the left is not a trick picture. It was made at the first meeting of the Twin Brothers Club in Los Angeles, Calif. Only men who look alike are eligible for member- ship. These four sets of twins passed the entrance tests with flying colors. Six Instruments in One IS own orchestra and _ orchestra leader at the same time, S. L, Norris of Dalton, Ga., has invented a remarkable device that enables him to play a fiddle, a guitar, and a ’cello all at the same time—and a whistle, banjo, and set of bells besides, making a total of six pieces in all. Foot pedals and strange gears are features of his ingenious invention which was recently exhibited at a fiddlers’ con- vention in Atlanta. The photograph } below shows it in operation. When a fiddler combines mechanical ingenuity with musical ability, something unusual is bound to result. Here is S. L. Norris, of Georgia, with his one-man, six-piece orchestra

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A part against it, yh at the was made 1 Brothers Inly men member- assed the ‘S. One orchestra ie, S&S. ivented a s him to cello all tle, banjo, + a total of gears are ion which llers’ con- hotograph

POPULAR SCIENCE MONTHLY

Sixteen-Ton Bridge Holds Sixty-Ton House HEN moving day came around for the owner of the large frame house pictured above, in West Newton, Mass., he decided to take his house with him over the railroad bridge to the other side of the tracks. The photograph shows how the remarkable engineering feat was accomplished. ‘Though the bridge was rated for a load of only sixteen tons, heavy timbers supported it safely during the moving of the sixty-ton dwelling. Telephone and telegraph wires were cut in order to allow the house to pass. A Diamond Rush in Action ‘AS DIAMOND rushing is staged to- day, it’s length of leg that counts, and the winners win by seconds. When British government officials gave the signal that startled the latest South Africa rush to stake diamond claims at the Grasfontein farm, a remarkable scene, pictured below, was enacted. As though shot from a bow, thousands of bare-legged fortune-hunters dashed across the veldt to seize the best spots of the world’s richest diamond field. Men, women and children, they had been waiting for weeks for this moment. The photograph shows them just after the start. Many large diamond companies

hired professional runners to race ahead and secure the finest claims. <A vivid picture of a modern diamond rush was drawn by Edgar C. Wheeler in the March Porputar Scrence Monrueyy in his article, “Crystals of Fire.” Blood 1-20th of Man’s Weight wo a man gives a quart of blood for a transfusion, he parts with more than a fourth of his entire life stream, recent tésts have shown. The average healthy man possesses an amount of blood equal to 4.9 percent, or about one twentieth of his total weight; for example, if

Doll’s House in Match Box IGHT housekeeping on a small scale goes on in this tiny doll’s house, constructed in a match box. The designer of the minute apartments, Charles W. Aldridge, of Battersea, England, spent thirty-five hours “building”’ it, and mak- ing a doll small enough to be the occupant. A masterpiece of tinycraft, it is com- pletely furnished, even to pictures on the walls and a covering on the table. New Depths for Oil Wells MOE than 8,000 feet deep and still going down, a California oil well is already the deepest well in the world. Advances in rotary drilling machinery have made possible many recent depth records, and wells two or three miles deep are predicted for the near future.

you weigh 160 pounds, you have about eight pounds of blood—a little less than four quarts. The quantity of blood was determined by in- jecting dye into each sub- ject’s circulation. Three minutes later, samples of the blood were taken. The extent to which the dye had been diluted showed the amount of blood possessed.

U. S. Phones England a Sample Toot MONG the first novel uses made of the new trans- Atlantic telephone between the United States and England was that by an enterprising middle- western manufacturer of auto- mobile horns. To close a sale in London, he mounted his new two-tone horn near the phone, as seen in the illustration above, and sent a sample toot across the Atlantic. The musical sound was

Racing for diamonds! This is what the recent South Africa diamond rush at Grasfontein actually looked like after the starting signal was given. Each participant carries pegs with which to stake out his claim °

clearly heard by the customer , four thousand miles away.

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58 POPULAR SCIENCE MONTHLY July, 1977 Handy Aids for Homemakers Spear a potato with this remarkable fork, hold it over a plate, and presto! the hot potato is pushed off automatically. Meat, cake, or waffles are also served more handily with this convement new device Especially designed for travelers is this electric iron, with its detachable handle that can be clipped in place by a spring or packed separately ina small space. High and low heats are provided by reversing the position of the connecting plug. In the base of the iron is a hole in which a curling iron may be inserted as shown above + In a new handy set of scientifically-made instru- ments for candy making are a special candy thermometer to control the temperature of the mix and keep it from burning; a “‘sugar meter” that measures the sweetness of the syrup; and an oven thermometer. Another useful new device, which this housewife is holding in her left hand, is a low- temperature thermometer for the home refrigerator Here’s the modern way to boil rice—in an alum- inum ball with holes in the sides, like a huge tea ball, which unhinges to let cooked food drop out Gas heat is saved by an ingenio.s metal rimg that fits over any burner of the gas Tange. It prevents the outer gas flame from spreading in all directions, con- centrating it directly under the utensil to be heated. Not only is waste elim- inated, it is said, when the novel de- vice is used, but cooking is more rapid A new egg beater is shaped especially to fit in an ordinary coffee cup or glass tumbler, to avoid waste when, for instance, only a single egg is to be beaten. Adaptable, of course, to larger bowls, too, it makes a serviceable all-around utensil for the kitchen The clothes hamper, like the san- itary kitchen garbage can, is now improved by the addition of a handy foot pedal arrangement, —— — a oa ho blapmang Here’s another modern improvement for This ph hes perforated pth the cake pan! A mica window in this pan sides, for thorough ventilation, makes * possible to watch how the baking Juice won’t spill over the edge of and is patterned to resemble rattan ag ne without taking the pan — this new pie plate. Beyond the place the top of the stove or even removing where the rim of the ordinary pie heat-retaining lid. A small hole is also plate usually ends is another wide provided, through which the cook can im- sert a straw to find out if the cake is done outer rim, to keep the liquid in and so retain the flavor in the pie ee. ae es a

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July, 1927 POPULAR SCIENCE MONTHLY 59 Electric Table Fan, Rice Boiler, Novel Clothes H. am per, Dishwasher and Other New Devices Lighten Housework - July, 197 CTS velers is tachable . in place With a hole in its cover for the razor itely ina handle, as shown above, a new bath for heats are razor blades is said to keep them free position from rust, and even to remove invisible the base particles of rust in new blades. The con- a curling tainer is so designed that the blade itself wn above does not come in contact with any hard substance, but hangs from the handle Here’s a device that cuts the doughnut and puts the hole in besides. In skilled hands it disposes of a mass of dovgh with amazing speed, whirling out doughnuts as it goes. A snap of the wire holder, and the tool comes apart for cleaning, without the removal of screws, as demonstrated in the upper picture Unique in shape, the new elec- tric dishwasher above uses whirling sprays of water within its domelike hood to clean the dishes. An electric motor con- cealed in the base spins the jets; and rubber connections lead the water from faucet to washer and back to the sink. The nineteen-inch wire basket within the hinged cover holds all after-dinner dishes, includ- ing silver, of an average family Five times as fast, it is said, as you can beat eggs or batter by hand, this motorized ptr. Dover beater does it for you. Its cord plugs fps Seal into the wall socket, and a switch at the This iron stand performs the additional tiene, oul side of the sturdy motor varies its speed duty of saving current and preventing the the utensil electric iron from overheating. If the house- waste elim- wife is called away to the telephone or other - novel de- duties while ironing, replacing the iron on more rapid its stand automatically shuts off the current An electric fan that rests horizontally on the table, can be picked up by a handle, and vement for plugs into any socket like a portable lamp, in this pam is an interesting novelty. Its strong up- the baking ward breeze maintains the surrounding air With completely automatic time and tem- he pan from in circulation without creating dangerous Open one leg of this bridge table and the rest perature control, a new electric range may moving the drafts or blowing directly upon persons unfold automatically, at the same time! be set to cook for any desired time, at what- nole is also near by, according to the maker. A guard Ingenious levers connect them so that they ever temperature you wish. Five switches ook can in- Protects fingers from the whirling blades work together and snap locked when open. along the front control the heat of the three ‘ake is done Folding in one leg causes the others to follow cooking plates and the oven top and bot- tom, giving three degrees of heat as needed

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POPULAR SCIENCE MONTHLY

ea

July, 1927

Ju ints for Radio Beginners ° ° ~ ° Capacity and Voltage Determine the Type of Construction EGINNERS in radio often become +: re, 8 a | broad tuning and lack of selectivity, completely bewildered on the sub- Testing the effectiveness of a groun( ject of condensers. The trouble is connection with scientific accuracy j, that too many names are applied to outside the range of amateur work, but a exactly the same article. For instance, is not difficult to determine in a rough \ the terms grid condenser, bridging con- way whether the ground is good enough, } denser, stopping condenser, by-pass con- With a poor ground connection, you wif rad il denser, plate condenser, filter condenser, find that removing the ground wire from § of : \ all refer to a plain, ordinary fixed con- the receiver makes almost no differeng§ of : denser of whatever capacity is required in the strength with which local station § smo at that particular point in the radio ave received; and on the rare occasion = out |, circuit. when distant stations are tuned-in with} No: In fact, there is no difference, from an good volume, disconnecting the ground § _ tical electrical point of view, between the two may result in only a slight decrease jg} in : \. condensers shown in the photograph on signal strength. resp ™ this page except that the small one is of You can be sure that if connecting@§ deve fixed capacity and the larger one can be disconnecting your ground makes litte} depe ) adjusted to any capacity from a very low difference in reception results, you— batt & minimum up to the maximum obtainable ground connection is not as good asitf fect when the movable plates are fully en- should be. men gaged with the stationary ones. Both are Under ordinary conditions, the bet sligh of .00025 microfarad capacity, and while possible ground for radio purposes isaf_ ity the larger condenser ordinarily is used wire properly clamped to the water supph§ Eve as a tuning condenser because of the pipe as near as possible to the point wher volt variable capacity feature, it could be used / it enters the building. The next bef that in place of the small fixed condenser with ' ground is a connection to the cold wate§ sisti1 . . ‘ : These two condensers are electrically the same. . : : eT ae : ‘ \ identical results. She Gitenenee fa, Gee tateet ene ts elbenaiite pipe somewhere upstairs. And if yoy now ' All condensers, no matter by what high can't do that, connect to any availabk§ the | y sounding name they are called, consist, point on the cold or hot water pipinge§ labor essentially, of some metal plates separated to the steam or hot water radiator. Th Ye by air, mica, paper or other nonconductor. trouble with connections made to am that And, assuming that the condenser is made point on the piping upstairs is that th® ably of high grade materials, it has only two joints in the piping may produce rathe§ _ perfe qualifications that are important to the high resistance because of the pipe com§ your user. You will want to know its capacity pound used in them. varia in microfarads and the voltage it will Don’t use the gas piping as a ground speal stand in continuous duty without break- In the first place, this is forbidden by th they ing down. rules governing your fire insurance; in tk} batte Its ratings on these two points deter- second place, the gas pipe is a poor grounl Bu mine the type of construction that will 4) anyway. In most installations, theres— man- prove most economical, and have an while the water supply pipe is the best ground an insulating bushing in the pipe some cease important bearing on the size of the for radio, pipe driven in the soil will give good where near the meter. preve finished article. The capacity of any ‘esults if you sink it far enough in a damp place When no water supply pipe is availabe must condenser’ is determined by the area of the radio fan must construct his om§ Knov _the plates, the distance between them, poor ground connection will show up in ground. The simplest way is to drivesg batte and the material used as insulation. The the form of generally weak reception, pipe at least three feet down into dam voltage is determined by the spacing of particularly on distant stations; and ground. Merely driving a short lengthd ft the plates if air is the insulator, and by occasionally a poor ground is the cause of _ pipe inte sun-baked top soil will not git § the thickness of the insu- you a good ground. tig batte lation when paper or some ABC’s of RADI O absolutely necessary W™ they” other material is used. get down to damp earth§ glass The higher the capac- IF YOU find it necessary to save one way of saving money that When there is doul— pure | ity, the greater the area of every possible penny in buying —_ doesn’t entail any reduction in the about the condition of th§ water ihe plates and the higher parts for a radio set that you expect efficiency of the finished set, pro- soil, it will prove worl Placec the voltage, the more in- to build, divide your money so that vided you do a careful and work- while to bury seve with . : at least the important parts willbe manlike job. So little can be saved cig <e — to i sulation must be used. cele ae eames b teied Canina Mined a square feet of metal # In: r | ee ae ¥ f 3 as high-grade as possi e. or in- y pure 1asIng Oow-grade nixed con- ae : . ail ] 7 afte aumb That is why fixed conden stance, the tone quality and conse- _densers, grid leaks and other small dec ply aS possidle & | serfs vary In size 1n propor- quently your enjoyment of the set __ parts that it is not worth while to making a solid connectitt plates tion to the capacity and will depend entirely on the quality get anything but the best. A plain to the metal with a heawg pacity working voltage. of the audio transformers in the _ piece of dry wood will serve as a piece of copper wire, § the po audio amplifying end of the set. panel until you can afford a bake- as No. 6 or No. 4. nectec Be Sure to Have Save money elsewhere if you must, _ lite or rubber one. ; copper can be used, bit the ce re but be sure to get modern, high- In short, have the important equally good results @ plates a Good Ground grade audio transformers. parts as high-grade as you can and he aieinined teem any de the jy er ie You can buy cheap variable con- save by constructing many of the oer caus alien connex SeCeE Sto we densers and they will work reason- simpler items, including the cabi- me wae ee tri quently is due to an ably well, at least fora while. The net. Basically your set will be good. can. It also is a good ideg § Ps unsatisfactory ground con- same may be said of tube sockets. Later on you can add parts to in dry weather, to pt termin Sometimes a complete a high-grade outfit. water on the ground. indivic

nection. Winding your own tuning coils is

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July, 1927 TS selectivity, a ground ccuracy js | vork, butit in a rough od enough, yn, you will 1 wire from » differenc cal stations E Occasions 1ed-in with the ground decrease in nnecting o nakes litte ults, you good as if ;, the bes rposes is 4 ater supply point wher » next bed cold wate ind if you y availabk ‘r piping & liator. The ide to any is that the duce rather > pipe com s a ground} iden by th ance; in th poor grount ns, theres pipe some is available ct his om ; to drives into dam rt lengthd vill not git ound. Iti cessary W lamp ea > is do lition of th rove W ry sever f metal # ssible alle | connectiag ‘ith a heavy r wire, § o. 4. Shee » used, bil results cf om any oiler or a good ides er, to poll ‘round. July, 1927 POPULAR SCIENCE MONTHLY 61 Perfect A-Current for Your Radio A Storage Battery Will Supply It—Hzints on Charging, Installation and Care That Wall Insure Best Results N SOME respects the storage battery that you use to heat the vacuum tube filaments in your radio set is a unique piece of apparatus. It is capable of supplying an absolutely smooth flow of current with- out a trace of fluctuation. No other commercially prac- tical piece of apparatus is in a class with it in this respect. In fact, laboratories devoted to scientific research depend entirely on storage batteries when they need per- fect direct current—in experi- ments, for instance, where the slightest tremor or irregular- ity would spoil everything. Even on high direct current voltages this holds good, so that storage batteries con- sisting of hundreds of cells now are a standard part of the equipment of any good laboratory. You can be sure, therefore, that if your storage battery is in reason- ably good condition, it will give you a perfectly noiseless flow of current through your vacuum tubes. You may hear various noises coming out of the loud- speaker, but you can rest assured that they are never caused by the storage A- battery. But a storage battery, like any other man-made device, can break down and cease to function properly. In order to prevent that unpleasant possibility, you must give your battery proper care. Knowing what takes place inside the battery will help you do it. HE illustration on this page gives a good idea of how all lead acid storage batteries are constructed. Essentially, they consist of an acid-proof rubber or glass jar for each cell. The solution is pure sulphuric acid mixed with distilled water. Positive and negative plates are placed close to each other with separators between to insulate them. The aumber and size of the plates determine the ca- pacity of the battery. All the positive plates are con- nected to one terminal of the cell and the negative Plates to the other. Then the individual cells are connected in series by lead strips burned on to the terminals. Since each individual cell develops By ALFRED P. LANE All lead acid storage batteries are built this way with minor variations, depending on the capacity and the service for which the battery is designed approximately two volts regardless of the size or number of plates, the total voltage of the bat- tery is the sum of the voltages developed by the individual cells. That is why a small capacity bat- tery runs a six or eight tube radio set just as well as any larger size. Both positive and neg- ative plates are made from grids cast out of lead to which a little antimony has been added. The lat- ter metal adds stiffness to Modern batteries are so carefully constructed that the chance of an acid leak is remote. tray put under the battery can be used for extra protection A rubber mat or a large glass the plates and helps to pre- vent them irom _ buckling. Lead peroxide is pasted into the openings in the positive grids while the negative plates are pasted with litharge. During manufacture, the plates are subjected to tre- mendous pressure to make sure that the material will stay in the openings in the grids. The storage battery actual- ly does not store electricity. It is a storehouse of chemical energy that is capable of pro- ducing electricity. The proc- ess is reversible so that after the chemical energy is all used up, a current of elec- tricity can be passed through the cell in the opposite direc- tion to restore the plates to their originat condition. When a metallic circuit is made between the positive and negative terminals of a Be sure to use a fuse in one of the wires leading to your storage battery. It will prevent the possibility of a fire from a short-circuited wire storage battery, current flows. through this circuit. The chemical action required to produce the electricity causes lead sulphate to form in both positive and negative plates. This action also reduces the amount of sulphuric acid in the solu- tion. Reversing the action—that is, forcing current through the battery from some outside source—changes the sulphate back to lead peroxide and litharge or sponge lead and increases the amount of sulphuric acid in the solution. Conse- quently the amount of acid in the solu- tion at any given time is an accurate index of the state of charge of the battery.

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H tT i | } 62 Sulphuric acid is much heavier than water, so that, as the acid goes out of the solution into the plates during discharge, the weight of the solution becomes less and less and a hydrometer floating in the solution would sink lower and lower. However, the lead sulphate takes up more space than the material from which it is formed, and if the battery is discharged too far, this sulphate will clog up the pores of the plates and swell and buckle them. And if the battery is allowed to stand in a discharged condition, the sulphate becomes hardened in such a way that subsequent charg- ing does not reduce it and the bat- tery is permanently injured or, perhaps, completely ruined. H Storage batteries are rated according to the number of ampere hours of electric current they can supply on one charge. An ampere hour means a current of one am- pere flowing for one hour. For low rates of current consumption, as in radio A-battery use, it is easy to compute approximately how long a battery of a certain size will run any particular radio set. Just divide the ampere hour capacity of the battery by the rate of current con- sumption of the set and the result is the number of hours the set will run before the battery needs recharging. If, for example, a set takes one ampere of cur- rent and is connected to a sixty-ampere hour battery, you will get sixty hours of use on a charge. If the set takes two amperes the battery will run it for thirty hours, and so on. Although a storage battery supplies perfectly smooth direct current, it is not necessary to have a uniform flow to re- charge it as long as the pulsating current flows in one direction and the average rate of flow is within correct limits. O STORAGE battery should be charged at a higher rate than is needed to give it a complete charge in eight hours, and it is better to use a rate that will fully charge the battery in about sixteen hours’ time. Much lower rates than this can be used with good results, and consequently trickle chargers with a half-ampere rate are coming‘into use very rapidly. A storage battery is like an automobile tire in that its length of life is well defined. You can bank on a high-grade tire’s lasting for from ten to fifteen thousand miles; if your storage battery gets the proper care you can be assured of from four to six years of satis- factory service. In time the active material in the plates falls away and settles in the space provided at the bottom of the jar. Eventually the space ‘s all filled up with the active material that is dislodged from the places, they are short-circuited by the piled-up sediment, and the life of the battery is ended. The amount of space allowed below the plates in the battery always is made large enough so that by the time the short circuit occurs, the plates are practically worn out anyway. But a huge percentage of POPULAR SCIENCE MONTHLY Don’t Do This! YDROGEN and oxygen are produced in the storage bat- tery, especially while it is being charged. These gases individually are colorless, odorless and harmless, but when mixed together in the space above the solution in the battery, they will explode with great violence if ignited by a spark or the flame from a match. If you want to inspect the level of the solution, use an electric flashlight—Don’t use a match! batteries used for radio work never live to a ripe old age. Abuse and neglect cut them off in what ought to be the prime of life. Insufficient charging ‘is the most prev- alent form of abuse. Allowing the battery to stand discharged comes next. In either case the result is the same: the active material in the plates turns into hard sulphate. HE storage battery is a long-suffering piece of apparatus. It will keep deliv- ering current like a game fighter under con- ditions that are ruinous, and then it will suddenly throw up the sponge when you least expect it. Unfortunately, too, stor- age batteries stand mistreatment without showing signs of distress. It would be better if the battery turned bright red or set up a tremendous noise at the first sign of mistreatment, to warn the radio fan that something was wrong. Any good storage battery will keep the tubes in your set lighted for many hours after it has passed the danger line of chemical exhaustion and the point where injurious sulphation starts. This means that you must not keep on using the battery until the tubes go out. And if you do happen to run the battery down to complete discharge by accident, waste A good way to forestall corrosion is to clean tl.e terminals and the top of your battery every few months with a rag moistened with ammonia and then smear a thin coat of vaseline on the terminals July, 1927 no time in connecting up our charger and giving the battery a full charge, with a couple of hou | overcharge for good measure. One peculiarity of the lead acid storage battery is that it doesn’t charge properly if it is exhausted and the charging rate is too low Radio fans have found themsel veg in trouble on this account without knowing what was wrong. The maximum and minimum charging rates depend on the surface area of the battery plates. You can apply a half-ampere charging rate from trickle charger to a small battery say one having a thirty ampere hour capacity, which will gradually bring it up to full charge even if itjg down to the limit of safe discharge, : But you may have trouble if yo | use the same rate on a battery of [ 120 to 150 ampere hours. The | trickle charger will keep the big | battery charged once it is brought i to that condition by charging at a higher rate, but even then, the big battery is not so desirable because g greater percentage of the charging current | is wasted in replacing the internal losses, : which are in proportion to the size of the | battery. y That is one of the reasons why it actually is better to buy a small battery rather than a large one if you expect to use a trickle charger. And if you are going | to keep the battery charged at all times, there is no need for the larger and mor expensive battery anyway. Keeping your battery charged is you first consideration, but care in other directions is necessary also. Be sure to place the battery where it is easy to get at. Then when it become necessary to add water or test it, you wil not shirk the job because of the trouble ae ND remember that while noises from the loudspeaker never come froma any | action inside the battery, there is plenty | of chance for trouble with poor connec. | tions in the wiring. Make sure that | the wires from the storage A-battery ti | the radio set are of ample size. The far. ther away the battery is from the radio set, the larger should be the wires. No 18 wire is large enough if the battery is only a foot or two from the set, buti you have the battery in the cellar ori near-by closet, use No. 12 wir} Whatever size wire you use, pay particular attention to the bint) ing posts. See that they ar firmly clamped on the wire and | that the bared end of the wir is clean and free from corrosi0n | This is most likely to occur @} the binding posts at the battery, | s* itis a good plan to inspet these connections every fet months or at the first sign d noisy reception that isn’t cause by static in the air. Wiping off the top of the bat tery and the binding posts witha rag moistened with ammonia is4 good way to forestall corrosiét | After you have the top of the bat } tery cleaned, go over all the &| posed lead parts with a vaseline) covered rag. Corroded terminal and a (Continued on page 13) Jul pai pal wo is ¢ wh was sho fit. we | the louc tub eno wire trie but hav alon livir radi wire to a with I br dow of t latec plac

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july, 1927 2am aULerY 9 of hours | re. ead acid - doesn’t chausted too low, emsel veg without g. The charging € area of an apply e froma battery, - ampere | radually ren if itis ischarge, | le if you | attery of | rs. The : the big 4 | brought ; irging at hen, the | ecause a | g current | al losses, ize of the Se why it | battery expect to are going all times, and more d is your in other where it , becomes , you will e trouble, yises from | frora any | is plenty \ r connec. sure that | yattery to The far. | the radio rires. No. pattery is t, but il ellar or . 12 wire | use, pay |) the bind | they ar wire ant | the wit COrTOsiOn , occur @ | e battery | fo inspect very few t sign d vt ca f the bat sts witha nonia is 4 corrosion / of the bat 4 ll the e&| vaseline’ terminal n page 13) July, 1927 POPULAR SCIENCE MONTHLY 63 You Need a Lightning Arrester How One Man Nearly Burned Down His House Before He Learned the Importance of This Radio Protective Device NEARLY burned down my house just to save a dollar! And even if I was Incky enough to avoid a serious fire, saving that dollar cost me a new pair of window curtains and a painter’s bill for touching up the woodwork where the flames had scorched. Doing odd jobs around the house is one of my chief amusements; so when my wife and I decided that it was about time to get a radio, I shopped around a bit to buy an out- fit. We had settled on the amount we could afford to pay, and it took some careful figuring to stay within the limit. I picked out a set and a loudspeaker and batteries and tubes, and after that there was just enough left to get some antenna wire and insulators. ‘The dealer tried to sell me a lightning arrester, but the extra dollar for that would have pushed the total beyond the top limit; so I decided to get along without it. There was a table near our living room window that made a fine place for the radio. I strung the antenna wire from a pole on the roof to another one on the garage, with an insulator at each end. I brought the end of the wire down io a binding post on one of those flat strips of insu- lated metal designed to be placed across the window sill so that you can shut the win- dow down on it. The other end of the lead-in insulator I connected to the antenna binding post of the set. The radiator in front of the win- dow turned out to be a good enough ground for ordinary use. “If my wife hadn’t put out the flames with the water in the vase, we’d have had to buy new goldfish besides paying for the rest of the damage!” The set worked fine for several months, until one spring evening, when I was reading the paper and not paying much attention to the broadcasting. “Harry,” said my wife, “what is the matter with the radio? Don’t you hear all those Snapping and scratching noises?” « “DROBABLY the batteries running down,” I replied absently, and went on with the paper. A moment later— “Oh, Harry! Quick, look! fire!” she shrieked. I dropped the newspaper and jumped up just in time to see angry red flames licking their way up the curtain behind the radio set. My wife already had grabbed a flower vase full of water and started for the window. I looked around excitedly for another vase, snatched up the goldfish bowl, and It’s on -As Told to NeEwTOon BuRKE if my wife hadn’t succeeded in putting out the flames with the water in the vase, we'd have had to buy a couple of new goldfish besides paying for the rest of the damage. There was a real storm going on outside by the time we had cleaned up the mess, and the flashes of lightning gave me a clue to what had happened. In fact, a severe shock in the arm when I grasped the antenna lead-in would have been evidence enough for anybody. The wire to the antenna binding post on the radio set had been tight when I first put it in, but the table had been pushed back to the wall and the wire sagged so that it was only a fraction of an inch from the radiator. I recalled how Benjamin Franklin had drawn sparks from a string of a kite flying during a thunderstorm, and I figured that my antenna had acted like Franklin’s kite string. The sudden surges of electricity induced by the electrical storm must have flashed across the small space between the antenna lead-in and the iron of the radiator. The edge of the curtain must have been in the path of the spark. It seemed funny to me that the electric current should have chosen a high-resist- ance path across the air rather than the solid metal path offered by the coils in the radio set, but you never can be quite sure of what a high-frequency discharge is going to do. It generally takes the shortest path if the longer path has many twists and turns in it, such as the coils in the radio set. To prevent further -trouble while the storm continued, I discon- nected the wire from the antenna binding post and wound the bare end of it around the radiator valve. The next day I stopped in at the radio dealer’s store and told him about our near- catastrophe. “It’s a lucky thing you were there when it hap- pened,”’ he commented, “or your house probably would have burned down. The fact that the radio would have been turned off if you had been out, wouldn’t have helped matters any. And what’s more, you wouldn’t stand a ghost of a show of col- lecting any money from the fire insurance company, be- cause you were violating one of the clauses of your policy by using a radio set without a protective device or, in other words, a lightning arrester.” He brought out several different makes that had been approved by the Fire Underwriters. *“How do you install one of these lightning arresters?”’ I asked. *That’s an easy matter,” he replied. “Just fasten it with these screws to the woodwork right outside the window. Connect a piece of wire from one binding post on the lightning arrester and join it to the nearest point on the antenna lead- in. Then run another wire from the other binding post on the arrester down the side of the house on insulators and con- nect with a ground clamp to a three-foot piece of pipe driven into the ground. 2 “TF YOU find that you can’t drive a pipe into the ground at that point, you can run the wire through the cellar window and connect with a ground clamp to the nearest point on the cold-water pipe.” *“You can wrap up one of those right now,” I said. “I should have taken your advice in the first place.” é

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; t + adele — o4 POPULAR SCIENCE MONTHLY July, 1927 Building Largest Map a Giant Task wade sis wt a ae Me iit Preparing on a jigsaw one of the cardboard layers which, cemented together, give the proper eleva- tions of mountains and valleys to the plaster block Movies Preserve County Records AN you imagine yourself studying a map sixty-three feet from east to west and forty-six feet north to south? Such are the dimensions of the largest map of its kind in existence, now in con- struction at the Babson Institute, Welles- ly Hills, Mass. So huge is it that it covers the floor of an entire hall. Its scale is four miles to the inch, so you can almost find your home on it! When completed, it will be used for study and for photo- graphic purposes. The map will be a relief map of the United States and Canada, with moun. tains raised, plains leveled and valleys sunk to correct scale. Its most unusual feature is its curved surface, suggesting vividly the spherical nature of the earth, At present the foundation is practically re._, is pictured above. Over this, piece by piece, will be fitted the relief work, in plaster blocks molded to show the surface characteristics of a square section o country. The measurements for this painstaking job are all based on maps made by the Government. job would have taken four years and i volved endless files of information cards Instead, the “‘movies”’ were used. A battery of four cameras was set up in the vault containing the records Under the glare of powerful lamps, a clerk slipped a volume in place. Shutters clicked, and the camera film was advanced one space as its operator pressed a foot pedal and turned over NE of the strangest movies ever ade was recently staged in Seattle, Wash., when more than a thousand mo- tion picture reels were used to film the county records—the first feat of its kind in the world. A Seattle title concern was faced with the gigantic task of classifying two mil- lion records of real estate transactions stored a in the county vaults. The (Above) Projecting machines threw pictures of the rec- ords on a screen, page by page, from which clerks com- piled their informa- tion for cross-index- ing. (Right) The records were filmed with movie cameras Placed overhead the entire 2400 volumes were filmed. At the firm’s office, the records were thrown on screens while clerks speedily cross-indexed them. Each machine was equipped with a device by which the operate could spin the film t any point, just as if he were turning the leaves of a hook. The task was completed in 4 months. The film records, pre served in the company’ vaults, are now an Ik stantly accessible and complete library of real estate information. the page. Thus ins few weeks, page by page, | possib] lobster tell wl lobster: but th as man they gi Now are you quickly Andrev Note then tu : CO if t which 1 father widow. At fir grandfa his wife qualifie Sister, advise

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uly, 1927 Sk h moun | valleys unusual zgesting ie earth. actically nls, piece work, in e surface ction of for this on =maps s and ii on cards i. is set up records lamps, & Shutters id vanced -d a foot ned over us in@ by page, volumes ’s office, e thrown le clerks ;-indexed chine was a device operator » film to as if he he leaves task was months. rds, pre ympany’s w an IF ible and ‘y of jon. July, 1927 POPULAR SCIENCE MONTHLY 65 Sam Loyd’s Puzzles Time Your Mental Speed Six Fascinating Tests to Gage Y our Abilities maker offers here another set of his newest wit sharpeners. Your speed and accuracy in answering them will help you measure your mental equipment. Hundreds of our readers have told us of the pleasure and profit they have de- rived from Sam Loyd’s problems from month to month. To use them as mental tests, time yourself in solving them, then turn to page 133 for the correct answers and your rating. How Clearly Do You Think? HE old phrase, “as difficult to guess as the first cost of a lobster,”’ orig- jnated in the House of Representatives during the bitter tariff war between John Quincy Adams and Andrew Jackson in 1829. During the debate regarding a tax on raw material, a representative of one of the eastern states asked how it was T= world’s most famous puzzle possible to calculate the first cost of a lobster. This member, when pressed to tell what he knew about the price of lobsters, could only say: “Prices vary, but the original lobster catchers receive as many shillings for six dozen lobsters as they give lobsters for thirty-two shillings.” Now, from that rather confusing data, are you a clear enough thinker to figure quickly the original cost of a lobster in Andrew Jackson’s time? Note how long it takes you to answer, then turn to page 133 for your rating. A Problem of Logic CORRESPONDENT wishes to know if there is a law in any of our states which would have prohibited his grand- father from marrying the sister of his widow. At first blush, it would appear that his grandfather must first have died to make his wife a widow, and so have been dis- qualified from marrying his widow's sister. But closer inspection leads us to advise the young man that his grand- daddy was within his rights in leading the sister of his widow to the altar. Bring your logic to bear on this prob- lem, time yourself, then see, on page 133, whether you possess a legal mind. Can You Concentrate? SPORTIVE young hare, ambitious to disprove AZsop’s aspersion on his forefathers, challenged a tortoise to race him around a circular track 100 yards in circumference. They were to race in opposite directions, and the hare gave his rival a start of one eighth of the distance. The hare held suc: a mean opinion of the other’s ability that he loitered along, nibbling the grass, and only realized that the plodding tortoise was threatening his prestige when they met at a point where the hare had run but one sixth of his 100 yards. The aroused hare went at top speed for the remainder of the distance and was lucky enough to make the con- test a dead heat. How much faster did the hare go during that spurt than he went up to the time of their meeting? Here’s a chance to test your ability to concentrate. Time your answer; check your rating on page 133. Are You Quick at Figures? A LAND speculator, having paid $ 25,000 for a likely looking tract, divided it into plots of three lots each, which he disposed of at $750 per plot. His gross profits equalled his cost for seventy-five of the lots. Can you tell just how many plots the tract contained? ; Time yourself in solving this situation, then turn to page 133 to measure how high you stand in arithmetic. Where Ingenuity Counts ARON D. and Count C., two jovial gentlemen I encountered in the card room of a steamer, offered to initiate me in the mysteries of a new game. I lost the first game, and the baron and the count each won enough to double the stack of chips with which he started. The baron and I scored the second game, thereby doubling our respective table assets. Then, in the final skirmish, the count and I scored, doubling the chips - which he and I had at the opening of the third game. A mysterious feature of our session was that while each player won twice and lost but once, the baron and count quit winners, and I was a loser to the extent of four dollars. After that third game, our three stacks of chips were just alike. How much money did I put on the table when I started? This is a problem that will tax your ingenuity. See page 133 for your rating. Your Power of Analysis UNT MARY bought some peanuts for the children and gave to the eldest, a boy, one peanut and one quarter of the remainder. To the next in age, a girl, she likewise gave one peanut and one quarter of the remainder. To the third, a boy, she also gave one peanut and one quarter of the remainder. The smallest, a girl, also received one peanut and one quarter of the remainder. It was found then that the boys had received 100 more peanuts than the girls. How many peanuts did Aunt Mary keep for herself? Here is a test of your power of analysis. Time yourself, then refer to page 133 for your rating. Sam Loyd has prepared another set of his fascinating new test puzzles, which will appear in next month’s issue.

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66 Is Your House Too Hot or Cold? How Proper Insulation of Walls, Roof and Floors Will Give Summer Coolness and Cut Winter Heating Costs By Joun R. McMauon . OYS, we'll freeze to death unless we get shelter,” said the leader of an Arctic expedition to his party, caught in a blizzard far from their base camp. All hands began to cut blocks of snow and ice. These they laid in a circle, flying sleet cementing the joints. Within a short time the shivering men were snug and safe within the igloo, enjoying a hot supper. A small alcohol stove made the house almost too warm. The men stripped to their underwear. And it was fifty below zero on the other side of the snow walls! About the same time, a group of ex- plorers in the tropics received the happy gift of a cake of ice from a passing river steamer. How could they make it last with a temperature of 105 in the shade? “We'll wrap the ice in woolen blankets, men,” said the leader. “That will keep it until tomorrow, anyhow, and give us some long, cold drinks!” Between ice and wool, used for seem- ingly contradictory purposes in these two incidents, lies the story of insulation. It is a story that is important to all of us in its application to home comfort and economy. At first sight it is quite simple. But little study develops that the subject is as tricky as an outlaw mustang. CIENTISTS tell us that dead air is the supreme insulator. If that is so, why squander money on other materials when air is free and we can have plenty of it within our walls? The scientists explain that such air is not properly dead: it moves; it transmits heat and cold. To insulate practically, we must con- fine air, neither too much nor too little. A material that is merely air-tight is not enough; rubber coats and window glass, for example, are useful wind stoppers but do little to exclude cold. In buying our underwear, we do not buy on a basis of thickness; heavy cotton is not equal to thin wool, which some- POPULAR SCIENCE MONTHLY LATHING~ Rees, i) Seg ap Dees By A \ 7 fj, ~ \NSULATION CROSS SEC7/ON Be IMS ON We \ INSULATION i Method of insulating a house with mineral wool used as loose packing in walls and between floors ISSN SS ! it i | 1 | fe How the Bureau of Standards tests heat and cold resistant qualities of wall materials. A, warm chamber; B, cold chamber; C, panel under test; a, electric fans; d, electric heating coil; e, ammonia cooling coil; f, heat:ng control coil; g, conducti- meter and guard panel; A, recording thermometer July, 97 and summer. People are beginning ty realize that a house properly insulated means that they no longer need swelte and lose sleep on midsummer nights be, cause the place is like an oven. While the best job of insulation is done on a new building, much improvement can be effected upon an old structur, You can insulate your walls, roof and attic floor without great difficulty. Wher remodeling or even ordinary replacement is planned, insulation means simply selecting and applying the right material instead of anything that happens to be available. In general, figures for the insulation values of complete house walls place g wood house at the top of the list. Thatig, a wood frame house, with siding, paper, sheathing, lath and plaster, will be cool. est in summer and warmest in winter, Next ranks a brick house with eight-inch walls furred and plastered. Following is a list of wall values as given by various authorities. These values ar measured by the number of heat units— called British thermal units, or B. t. u— that pass through one square foot of stated thickness in a given time for each degree difference between inside and out- side temperature. From an insulation standpoint, therefore, the smaller the fig. ures, the better the material. B.t.u. per hour Brick, 8 inches thick.................m Brick, 8 inches thick, furred and plastered.% Cometete, GAneh. .... ioc ic csce ces sc 0 Hollow tile, 8-inch, with stucco...........4 Hollow tile, 8-inch, furred and plastered...% Concrete blocks... .. Concrete blocks, furred and plastered. a) Wood frame, siding, paper, sheathing) Rath amd plaster... 2... cece eens ecu sy These figures, it must be noted, ari not accepted by all authorities, owim possibly to differences in methods df testing and to variations in material A point of general agreement is the gail through having an air space, whethel due to air or the added resistance #) another wall or both. It also appear that in wood fram how keeps a better grip on its confined air. In general, light, porous materials are better insu- lators than dense, heavy ones. Cypress excludes more cold than maple, brick more than granite. Our ancestors solved the problem by building extra thick walls. We thinned the walls, hav- ing superior heating sys- tems for winter; ice and electric fans for summer. Today there is a general | a every detail tow standard constructie counts. Paper ald saves a loss of .07 of heat unit for each sq foot of surface eve hour. Another impo fact on which authop ties seem agreed that one inch of among several ins ing materials on # market in_ sheet quilt form is about equ to an eight-inch, 0& r! & . mY 3 NV tlhe | ad, tendency to insulate houses both for winter What insulation does: Escaping heat melted the snow on the roof of the unin- sulated house at the left; the roof at the right is insulated except for one spot side wall of frame masonry. This indie July, | that But ¥ wall F rial eC the ef whole orot fifth § cold 1: al a 2 ee U su that d by the ton. his he mable made cate € pes their t At jist, 25 ane of one | wool, minera other paper, wool. mate! packed sample binder. sheep’s wool a insulat prise m™ Amo ces, mi as loos and | Quilted ble, ce is naile constru is usué more t foot wi six inc nailed plastere inside « itis “gl rich mc an inch use on strengt] narrow HE rial Standar and .33, value t Even a’ ; an inch heat an side wa times a: being th for mate Labor the mat as is tl ma } furring

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July, i977 rd? ginning to insulated ed swelter nights be. ion is done provement structure, roof and ty. Where placement 1S simply it material ens to be insulation Is place a t. Thatis, ng, paper, ill be cool. in winter, eight-inch eS as given values ar at units— -B. t.u- re foot of .e for each e and out- insulation ler the fig. .u. per hour @ lastered.% stered. ..f red...... sheathing | 8) noted, ar} ies, Owing} ethods @ materia. is the gall , whether istance # O appeali od = fram il towat nstructicy ver alot of .07 of ach squat we eve importa h authon agreed h of il ins ; on & sheet bout equy inch, ow frame # s indie July, 1927 that jnsulation pays by a good margin. t we should not argue from this that a yall plus half an inch of insulating mate- rial equals a wall and a half. Considering the effect of insulation on the house as a ghole, we must remember that window ass area remains the same and is a constant source of loss. If a wall is one ffth glass and its resistance to heat and cold is doubled by the addition of insulat- ing materials, the total improvement is gctually only eighty percent. URNING now to the values of the in- sulating materials themselves, we find that definite figures have been established by the Bureau of Standards at Washing- ion. To the man contemplating insulating his house, these figures are of inesti- mable value. The Government scientists made their measurements with deli- cate electrical apparatus. Their sam- ples and methods were uniform. They tested a large number of materials under their trade names. At the head of the Government list, with insulation values between % and .29 for a thickness POPULAR SCIENCE MONTHLY A special wood fiber board is required for direct plastering or placing next to masonry. And with this it is advisable to use a quick-setting gypsum plaster with not more than ten percent of lime, to set within two hours, to avoid swelling of the fiber through moisture. A space of three sixteenths inch between the board units allows for expansion. 67 outer edges and six inches apart on interior studs or beams. Insurance against crack- ing of plaster at the joints may be had by nailing over them strips of metal lath four inches in width. The sugar-cane board is also used for outside stucco, preferably with lath on its surface, and sometimes the stucco is applied with a cement gun. The latter method of spraying on plaster of one inch, we find kapok, wool, hair felt, slag and mineral wool, felt and other fibers quilted in paper, corkboard, cotton wool. Several of these materials are loosely packed, and the corkboard sample has no artificial binder. That cotton wool, sheep’s wool and mineral wool wre much alike in insulating value will sur- prise most persons. Among these substan- ces, mineral wool is used as loose packing in walls and between floors. Quilted material is flexi- ble, comes in rolls and isnailed to studs in frame construction. Corkboard is usually one inch or more thick, and in pieces one foot wide by thirty-two or thirty- sx inches long. It may be nailed to studs and_ directly plastered, or placed against the inside of a masonry wall to which itis “glued”’ by a half inch layer of rich mortar. Corkboard less than aninch thick is hardly advisable for ue on studs because of lack of strength, especially owing to the narrow width of the pieces. Photo Weuer- haeuser Forest Products HERE are about a dozen mate- rials to which the Bureau of Standards gives a rating between .29 and .83, or slightly less in insulating with air pressure is speedier than elbow grease, but it is apt to be messy and not equal to handwork. About on an insulat- ing par with the fibers of wood and cane is an odd-sounding material, “eelgrass inclosed in burlap.” It reminds me of the swamp rushes which in southeastern Europe serve as lath under plaster. That it is not a novelty and is very resistant to decay is established by the condition of a sample which was built into a New England house 290 Photo Armstrong Cork & Insulation Co. Corkboard has high insu- lating value. It may be nailed directly to roof rafters, as shown in the photo above, and plastered (Left) Applying balsam wool between the studding. Its fexibility enables it to be tucked into corners and fitted around projections years ago. The eelgrass is made up as a quilted roll three feet wide. When applied to wood frame, it needs the support of headers every three feet between studs or beams, unless put on sheathing or laid upon a subfloor. Furring strips are requisite for a plaster job. The quilt has a thickness of one third to three fourths inch. Ceiba and balsa are tropical woods which, being very light and porous, have merit in house insulation. SO-CALLED wool has been produced from native wood and made into a flexible quilt one half to one inch thick and in widths from seventeen to thirty-three inches, for house insulat- ing purposes. The finely cut fibers are treated chemically to resist fire, and the makers claim the material will not burn. An adhesive sub- stance holds the fleecy fibers together and in firm attachment to the covers of asphalt-coated paper, which obviates stitching or puncturing the material. The quilt strips must run the same value than the materials above. Even at this figure it appears that an inch of insulation stops as much heat and cold as the ordinary out- side wall of a dweiling which is eight times as thick. And the cost is small— being three to twelve cents a square foot for material. Labor costs, obviously, are least when material is in large and rigid sheets, a is the case with wood fiber board. This may be plastered direct inside, but furring strips with wood or metal lath are advised for stucco exterior. Photo Samuel Cahot Inv. Insulating “quilt” being applied to studding and covered with lap siding. Reduced heating cost more than offset the insulation cost, this owner figured Sugar-cane fiber board is plastered direct in the same way. Moisten the board with light sprinkling one day before application. If the ceiling is to be plastered, put a cross piece or header, so-called, every four feet between ceiling beams, which are presumably of stand- ard spacing—sixteen inches on centers. Nail the board with one-and-one-half-inch roofing nails three inches apart at the direction as studs, beams or rafters. Strips of seventeen-inch width may be placed between studs close to sheathing boards, the edge laps being fastened to stud sides with lath nailed through. Or wider quilt may be tacked over the inside top of studs, to be followed with lath and plaster or any kind of wallboard. The material may be applied over furring strips on the inside of masonry wails. There doesn’t seem to be any possible connection be- (Continued on page 134)

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68 Seven Handy Kinks for Autoists Window Screens, Luggage Carrier, Table, Other Ideas gage to the running board of your car by the use of a rope arranged as shown in Fig. 1. The eyes should be bent up from an iron rod at least one quarter inch in diameter. By loosening the screws, the eyes can be turned under the running board when not in use. Yeu can lash considerable bulky lug- Secret Switch Foils Thief bf ort properly installed, the switch shown in Fig. 3 is so well concealed that the auto thief will never find it. As you get out of the car, slip the brass plate into your pocket, leaving the two screw SPACE FOR 4 LUGGAGE : j | Ne Lili 1) WW, LY) Rope UNDERSIDE OF RUNNING BOARD Fig. 1. Several special eyes and some rope ar- ranged in this way will hold considerable luggage DOOR CLOSED my 8 % yy, \ * CIRCUIT-CLOSING PLATE. REMOVED BY OWNER ON LEAVING CAR Fig. 3. Secret switch in ignition circuit to foil the automobile thief % " - ~~ Hip : | * ‘ TE SIPHON) WAIL at aE ' ae 7 Pp ssestesasasn : ! Il at ' Hit 1 Hii ' LOT Fiz. 4. To start the siphon, move hose rapidly up and down, applying thumb on the up stroke POPULAR SCIENCE MONTHLY Ten Dollars for an Idea! Pat KOSELKE, of Lansing, II1., wins the $10 prize this month for his suggestion of the auto win- dow screens (Fig. 5). Each month Poputar Scrence Montatiy awards $10 in addition to regular space rates to the reader sending in the best idea for motorists. Other pub- lished contributions will be paid for at usual rates. PEDAL EXTENSION (4, STEEL PLATE) Fig. 2. A wrought iron pedal extension of this design is convenient, safe and easily made heads exposed. The wires should be run inside the body lining so they will not show. If the sheet metal of the body extends over the surface where the screws are to be fastened, insulate the screws. Novel Siphon Starter OU can start a siphon with a piece of hose asin Fig. 4. Push the hose down with a rapid motion, at the bottom of the stroke clamp your thumb over the end; pull up and repeat until the hose is full of gasoline. This stunt will work only with gasoline or other free flowing liquids. Screen Your Car OR auto camping trips, screen at least two of the windows as shown in Fig. 5. The cross members are hinged so the screen can fold up. Cloth netting is used, the upper edge fastened with snap fast- eners and the lower edge held in place by the window pane, which is cranked up against the lower edge of the screen. Switch to Control Generator O CONTROL the output of the gen- erator, you can install a switch on the instrument board and wire it in series with the third brush and one or two head- light bulbs arranged in parallel (Fig. 6). When the switch is on, the bulb is short circuited and the third brush functions as usual. When the switch is off, the bulb is July, 1977 in series with the third brush and th output is increased. Pedal Extension Easy to Build S° LONG as cars are built to fit the average-sized person, the short mag or woman will have trouble reaching the pedals. A strong, yet easily built exten. sion can be built as shown in Fig, 2, A Table for the Auto Lunch ) Sev 4% shows how to build a simple table that will prove useful for servi luncheon in the car. When not in use, it can be folded out of the way. HINGED TOP BAR MM cA | if it ma) 1 1 i wll iy HINGED BRACE BAR NARROW STRIP winpow_ FR PLATE GLASS WINDOW CLOTH SCREEN ATTACHED TO SIDE BARS Fig. 5. Screens for at least two windows will add to your comfort when auto camping PUSH BUTTON SWITCH >> Sy ELECTRIC LAMP SZ) i | \ i N\ be ‘il LIGHTING GENERATOR Fig. 6. You can change the output of your charging generator by using this arrangement Fig. 7. A folding table that will prove handy on auto luncheon parties and is easily made Tes E

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July, 1977 CS and the . Build to fit the hort man ching the Lilt exten. ig. 2, unch a simple IMMUTATR 4 JSH ; R ut of your rrangement rove handy asily made Joly, 1927 POPULAR SCIENCE MONTHLY 69 Stop the Noises in Your Car Gus tells how to trace and cure the squeaks, rattles, hum and thumps that warn the driver something’s amiss aren, « EY, Joe!’ Gus Wilson shouted to his partner. “See if you can’t stop that infernal racket outside. I can’t even hear this motor run, much less tell if there are any noises in it!” Joe Clark swung open the door of the Model Garage and stepped outside. A second later the roaring and clattering subsided into a dismal clanking and then ceased altogether. Gus, with a grunt of satisfaction, picked up his stethoscope and soon was com- pletely absorbed in testing the car he was working on. The motor was purring as quietly as a contented cat, but Gus lis- tened carefully at every point where there was any possibility of noises that would reveal incorrect adjustments in the mechanism. “What are you doing—listening for the heartbeats?” asked a young fellow who had strolled up so silently that Gus hadn’t heard him. “Iam,” replied Gus, “if that’s what you want to call °em. Was that your car making all the racket outside?” “Yes, but don’t put that stethoscope of yours near my motor. It would bust your eardrums.” “QO I heard,”’ Gus growled. ‘‘ When are Wyou going to overhaul that junk ple, anyway?”’ “Junk pile! Where do you get that stuff?” snapped Will Otis, the owner of noisy car. “Maybe I’m anticipating a bit, Otis,” said Gus with a grin. “If the car isn’t junk by now, it will be very shortly if you leave it in that condition. Hang around afew minutes till I get this job out of the way and I'll have a look at it. You'll have By Martin Bunn if to take me for a ride, though—I want to find out what else I can hear besides motor noises.” When the two men were in the noisy car, Otis stepped on the self-starter and the motor started with a clattering roar. They drove about a mile, which included one rather steep hill. Gus made no re- marks during the ride, but he was making mental notes of the various queer noises that were assailing his ears. “I’m afraid it’s going to be a long list,” he said as they pulled up in front of the Model Garage. “Some of the troubles are your own fault and the rest of ’em are just natural wear or things that are loose. “PD ETTER make a list so you won’t forget any of ’em. First there’s a dull thump that means a loose main bear- ing, I'll bet a hat. Then there’s at least two connecting rods that need taking up. You can hear the metallic clank they make clear enough. Those clicking noises are loose valve tappets, and I wouldn’t be surprised if the cam shaft is a trifle loose, too. “That rumbling, grating noise that comes and goes with changing motor speeds probably is a loose timing chain that hits the side of the case now and then. And the rattle when you step on the throttle sounds to me like loose pis- tons. By the way, when did you put grease in the transmission last?” “It must have been nearly a year ago,” confessed Otis sheepishly. “‘I forgot about it, I guess.” “It costs money to forget things like that,”” said Gus. “It sounded dry as a bone. I hope the gears and bearings aren’t worn too badly. The rear end has quite a hum. I suppose you haven"t put any- thing in the differential case for a year, either.” “TI guess that’s right,” admitted the other. “You ought to have those things fixed,” said Gus. “‘The question is, though, do you want me to fix everything or do you want to do some of the work yourself? All the things I mentioned are shop jobs, but there’s plenty of noises about the car that you can fix yourself, if you want to save money.” “Sure I want to save money,” replied Otis. “If I don’t, I won’t have any to pay your bill for the rest of the work. What are the things I could fix?” “Don’t worry about them until I get rid of the motor, transmission and rear end noises,” Gus advised. “It will be much easier to find the smaller noises after the big ones are cured.” right,”’ Otis agreed. ‘I'll leave the bus here and you can get busy on the work you’ve mentioned. When shall I come back?” “In about a week,” suggested Gus. Otis showed up about a week later and Gus was ready for him. “*Take me for another ride,”’ said Gus, “and see if you notice any difference.” Otis said nothing until they had driven several blocks. “IT can hardly believe it’s the same car!” he burst out enthusiastically. ““Now I can see why you didn’t want to have me bother about the rest of the noises. They were drowned out by the ones you fixed. The motor sounds fine now, and the hum in the rear end is gone, but there’s a fine collection of rattles and squeaks I never noticed before. Where do they all come from?”

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70 POPULAR SCIENCE MONTHLY July, 1977 Gus smiled. “That’s for you to find out,” he said. “‘ Finding squeaks and rattles is just a matter of pa- tience and keeping at it. Rattles are easier to find than squeaks because a rattle always means something is loose somewhere. Squeaks are hard to find because parts can be fastened together so tightly that you can’t detect any looseness, and yet the jounces and jars will make them rub together enough to squeak like the dickens. “The first thing to do is to get out your wrench and screw driver and go over every nut and screw you can find—and from the way this car rattles, you'll find plenty of loose ones. . “It’s surprising what a loud rattle can come from a small part that’s just a trifle loose. At certain motor or car speeds, the loose parts get to vibrating. The smaller the part, the Gus says— “ WRENCH, a screw driver, an oil can and plenty of patience and F agemanger are the tools you need to get rid of squeaks and rat- tles in your car. Remember that the loudness of the squeak is no indica- tion of the amount of motion be- tween the parts that are causing the noise. And the squeak doesn’t al- ways seem to come from the parts that are actually producing it. Usu- ally the vibration is carried to some other part that sends the vibration to your ear.” are worn bright by friction and see jf the squeak stops. If it does, you can tighten up the fastenings of the doo, so there won't be any chance fy motion. “And don’t jump at conclusions jy deciding where the noise is comj from,” Gus continued. “Sometime one loose part will make a noise that is a good imitation of the noise yoy are likely to hear from some othe part. A fellow came in here the othe day to have the main bearings of his motor tightened up. He had heard, dull thump whenever the motor was puliing hard on a hill. I found the trouble, but it had nothing to do with the bearings of the motor. One of the bolts that held the motor in the frame was loose, and every time he opened the throttle and the motor began ty labor, it just naturally bounced w and down with a thump that cer. tainly sounded like main bearings, faster the rattle. Keep that in mind. If you hear-a real fast rattle, you know it must be some small part like the license plate or a section of the piping or perhaps one of the small rods that work the spark and throttle. “Those clattering noises you hear only when you strike a bump in the road are usually made by some large part that’s worked loose. Worn brake rod clevises and spring bushings make these parts. clatter like sixty when you go over bumps. Of course there isn’t any way to tighten up on spring bushings or brake rod clevis bearings—you ve got to replace them. Sometimes, though, most of the wear is on the clevis pin or the bolt that goes through the bushing in the end of the spring. In that case you can get rid of a lot of the looseness by using new pins and bolts.” “Why can’t I just tighten the nuts on the end of the spring bolts until they bind a little bit?” asked Otis. - ON’T try any bum mechanic’s jcb like that!”’ Gus growled. “In the first place, it won’t work because spring bolts are built with a shoulder that keeps the nut from doing anything except stop- ping it from turning. In the second place, the bolt wouldn’t stay tight for any length of time even if you screwed the nut on hard enough to cramp the spring clip against the end of the spring. “That’s nearly as bad as the job I saw a fellow who called himself a mechanic do on a brake rod clevis. He put it on the anvil and pounded it with a hammer until he had the holes oval in shape. They stayed tight for al- most two weeks,” Gus concluded. “Oh, I wouldn’t do anything like that,”’ Otis grinned. HIGH PITCHED HUM OR SQUEAK CAUSED BY NERAT It had been on the “*%*4TR WN a= Md ce HEADLIGHT tip of his tongue to @{ASs'Nav = suggest that partic- = JANGLE ular idea. “Now, about those squeaks,’’ Gus continued as they stopped in front of the Model Garage, “don’t be discour- aged if you can’t LOOSE RIMS / OR SPOKES. CAUSE CREAK- ING NOISES | HOOD FASTENINGS, LOOSE vt i. VALVE TAPPETS CAUSE CLICKING NOISE | BOARDS RATTLE LOOSE EXHAUST MANIFOLD CAUSES HISSING SQUEAK \ “4 - STEERING GEAR LON A first. Remember that a cricket can make a whale of a noise just by rubbing some of its parts together. Wherever there’s any chance for two surfaces to rub together, no matter how slight the motion is, there’s a chance for a squeak. “Squeaks are the result of vibration, and vibration is set up between two sur- faces that are rubbing together only when there is the kind of friction you get when the surfaces are dry. Dry wood rubbing against dry wood or against metal will start vibrations that travel through the whole mass of wood or metal. Then the air carries these vibrations to your ear and you hear squeaks. ss HAT’S why a car doesn’t squeak so much when you are out in the rain. The water gets between the rubbing sur- faces and lubricates them just enough to stop vibrations. Also, the water swells the wood and makes the joint much tighter, thereby eliminating friction. “Wood wheels that squeak after a spell of dry weather can be cured by throwing a pail of water over them. Rattling floor boards sometimes can be quieted in the same way. “Of course, oil stops squeaks much better than water because it doesn’t dry out in a few days. But you wouldn’t want to squirt oil all over your car on the chance that it might stop a couple of squeaks you can’t locate. “If you suspect that a squeak is com- ing from a particular spot—say from the edge of one of the doors—you can test it by putting a little oil on the surfaces that LOOSE BEARINGS/CAUSE METALLIC CLANK OR DULL THUD , RATTLES FROM LOOSE DASH FITTINGS FFLER~ PLATES BRAK WORN GEARS OR BEARINGS iN TRANSMISSION CAUSE GROWLING NOISES CAUSE HUM mi ie et, conNecrions [7 {REA WORN OR LOOSE GEARS IN REAR END “Then there was another chap who came in to have the commutator the generator touched up because he said it was squealing like blazes. Come to find out, it was the stuffing box bearing on the water pump. He had forgotten to lubr. cate it, and the dry packing was setting up enough friction to produce a nice, loud squeal. “One queer noise that bothered me for a while in a car I was working on turned out to be loose plates in the muffler. At certain speeds downhill, the loose plates would slide forward, closing up the pas sages. Then the gas pressure would slap them back again with a sound that wa a cross between a clank and a thud.” “There’s a bit of a commutator squeal from the generator of this car,”’ Otis inter. rupted. “ What’s the best way to get nd of it?” ™ ON’T do anything,” Gus replied “I looked at the commutator and it seems to be in good condition. Oftena commutator will develop a squeak that will go away by itself if you let it alone Of course, if the commutator is worn @ the brushes get so loose in the holders that they start chattering at certain speeds you ought to have the commutator truel up and fit new brushes. Sometimes the commutator will take on a kind of dirly glaze that makes it squeak. Wiping ital with a rag and a little gasoline wil usually fix that particular trouble. It isn’t a bad idea to clean the commutate that way once in a while, anyway, ani while you are about it, scrape the acct mulated carbon dust that is ground of the brushes out d DOORS SQUEAK. the slots betwee OR RATTLE ” the copper bars. “Gee!” exclaimel Otis, “I can see have a lot of heavy detective work ahead of me smoke out all the squeaks on this car.” “That’s the per alty for having § quiet motor,” sa Gus. “Keep at it though, and eventt ally you'll at leas get rid of the wort WINDOW GLASS MAY CHATTER LOOSE BODY BOLTS AUSE CREAKS AND THUMPING NOISES LICENSE PLATES RATTLE LOOSE SPRING SHACKLES KING NOISES BY LOOSE WHEEL 2 2 Try Study this diagram to heip locate the various noises your car makes. Careful listening will divide the racket into many different sounds, each of which has its particular cause noises. ” Seem to find them at

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July, 1927 july, 1927 POPULAR SCIENCE MONTHLY 71 and see if . you Can the door lance f, i Do you know:— lusions in , s coming — —how to avoid “‘orphans’’? ome Imes . =o t A Ow —how to buy a used car m. O me other J u , 2 a * dge from a friend: ngs of his Uu S e d d heard g % : notor was Ca r ‘ound the | to do with a= te) Ine of the the frame ¢ he opened | ‘s| IMNVESt Z*- you may Save *200 unced up : that cer. earings, i chapwho} a= IG) itator on se he said to fin ° ng onl Write us now for to lubri- e as setting your copy of this free book! nice, loud red me for AX . vote . hg re “ ne ate Seg on turned a irthday, Lhe Studebaker Corporatio uffler. At Pi g e America published a remarkable new book. one ed e to th Public The fund of facts in “How to Judge a Used aula sla on Used Car Sales Car” may easily save you $200 or more in buying 1 that wa a used car! This valuable, free buyer’s guide _ thud.” ; ‘ ; reveals frankly how to judge used car values, how tor squeal 1 Everyusedcarisconspicuously marked with its to find the best bargains—prints startling infor- ‘oon price in plain figures, and that price, just as the mation never before made public. price of our new cars, is rigidly maintained. Boiled down into ten minutes interesting read- ; ing are the safeguards experienced automobile us replies 2 All Studebaker automobiles which are sold dealers apply when buying used cars for resale. “— as CERTIFIED CARS have been properly Every paragraph is the summary of years of ueak that reconditioned, and carry a 30-day guarantee experience—every page is full of time-saving, t it alone for replacement of defective parts and free money-making pointers. 1 fora til service on adjustments, Pictures and text in this helpful used car man- age ual show you what code prices mean, why dealers in speeds — ) P ator trail 3 Every purchaser of a used car may drive it turn the speedometer back to zero, how to fix etimes the for five days, and then, if not satisfied for any the value of a used car offered by a friend, how dof Py reason, turn it back and apply the money to avoid “orphans” —and other important points _ ine wil paid as a credit on the purchase of any other the average buyer would over = . ouble. It car in stock—new or used.(It is assumed Send the coupon below zow for your copy o ym mutator that the car has not been damaged in the this helpful guide to’greater value. Learn how yway, and meantime.) to get more for your motoring money. Invest 2c Pee ‘ in a postage stamp—it may save you $200! res out d To the Public: We pledge adherence to the ee 7 mee above policy in selling used cars. | DepartmentG56, South Bend, Indiana or bars. ; po : Please send my copy of valuable free booklet, ‘How to Judge a | exclaimel . Used Car.” can seek dtudebake. Dealer I t of heavy pe ner a a all th ° ° ! _— i 8 ssictngeeetsncantteienintea sal State....... diated 5 n thiscatt Sign and Mail the Coupon Now: ananonene een aon ane ome s the per having # sa 89 LT U DEBA KER nd event Il at leas This is a Studebaker Year the wort _

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‘72 POPULAR SCIENCE MONTHLY July, 1927 Jul

LL On making a House into a Home Make a Garden Trellis from Plan No. 22e HOME is what you make it. It starts as a bare house on a plot of ground. | Then some one sets out shrubs. The first skimpy grass develops into a rich green lawn. Vines—either plain or flowering have turned many a house into a home. Have you ever thought of building a garden trellis? It is comparatively simple when you have Stanley Plan No. 22e to help you. eI But did you ever think of this? The oc- casional user of tools needs good ones even more than the professional. For good tools are a real encouragement to good work. Y You can buy Stanley Tools separately and so collect your own set. For your conve- nience in buying there are also complete sets of Stanley Tools in chests at a wide variety

of prices from $15 to $95. Or there are @ assortments in strong cardboard boxes con- 2 taining directions for making your own tool have chest. Priced from $5 to $20. ot <— ) plied oi: appr mad Your hardware dealer has Plan No. 22e as well as other ‘a ' Stanley Plans for making useful articles, or he can get a them for you. The plans cost only 10c each. Ask him, also, for y for small Catalog No. Se50, which shows many useful pens Stanley Tools. It is free. If he cannot supply you write ode to The Stanley Works, New Britain, Conn. Now able, all store | © the p | ter | ment ‘|| The best tools are the cheapest to use in m ; Ask your hardware dealer | hood Buy separately or in assortments ER paper | ] fii carrie eae | An a ——f motif obtai At & pai paper eled « nn | ished —<=F) moist

© This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6

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July, 1977 nd ye- ets ty re n- 901 her get lso, eful rite July, 1927 POPULAR SCIENCE MONTHLY Wo f \ Arthur Wakeling. Editor JB You Can Decorate Furniture and Craft Work with Astonishing Ease by Using Inexpensive Decalcomania Designs O POPULAR has become the use of transfer patterns on commercial furniture and art wares that it is surprising more home _ workers have not taken advantage of this decora- tive vogue. Many, of course, do not understand how easily transfers are ap- plied and still fewer amateur decorators appreciate the variety of brilliant effects made possible by these designs. Decalcomania (de-kal-ko-mania) trans- fers, as they are called, have been used in the furniture trade for years to give ex- ~A pensive pieces the artistic finishing touches they need. Now they are avail- able, too, in almost all department stores (usually in the paint or art ma- terials depart- ments), as well as In many neighbor- hood hardware, wall paper, and paint stores; and they are carried by the larger mail order houses. An almost endless variety of designs, motifs, colorings, shapes and sizes can be obtained. A transfer is nothing more or less than & paint film attached temporarily to a paper backing. When applied to enam- eled or lacquered furniture or other fin- ished surfaces, the paper backing is moistened and removed, the paint film A center line on the back of the transfer is a great aid in placing it centrally and vertically By BERTON ELLIOT Varnish or other adhesive is applied to the transfer and allowed to stand until “‘tacky”’ After being saturated with water, the paper backing is either lifted up or slipped off The transfer is pressed down, from the cen- ter outwards, with a rubber roller or a cloth being left attached to the surface. Some transfers are quite flat, while others have a texture and depth that make them appear almost as if hand painted. The best types have virtually the appearance of hand painting; you can see the brush marks! The main use of transfers is, of course, on painted furniture, that is, on pieces which have already been finished with white or colored enamel or lacquer. They are used less often, but frequently with striking effect, upon natural finished fur- niture—pieces that have been stained and varnished. The many ways in which this can be done are best learned by ob- serving closely good examples in a high class furniture store. Among the most popular motifs are floral designs, which are appropriate for almost every decora- tive purpose. Ships are much in vogue at present, although their use is more re- stricted, as are bird and fruit designs. Many colorful nursery pictures can be obtained; these work wonders in brighten- ing up both the furniture and permanent woodwork in children’s rooms. Silhouette transfers fill the need for a contrasty, posterlike style of treatment. Medallions are useful for (Continued on page 88)

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74 POPULAR SCIENCE MONTHLY July, 1927 Huilding a (Corner ©loset An Easy Method of Constructing a Colontal China Cabinet in Any Dining Room—How to Keep the Cost Low F THE many decora- O tive arid useful built- in furniture units now obtainable, the corner china closet ranks among the first in the estimation of home owners. This is as it should be, for not only do the fine lines of Colonial doors lend dignity and charm to a room, but the spacious interior of the closet holds all the china, cut glass and table linen that a family of ordinary size re- quires. This type of closet is a favorite with housekeepers, because it is out of the way and takes less floor space than the ordinary cumber- some and somewhat fragile china closet. As the first step in building a closet of the type illus- trated, it is a good plan to make the lower door. It is not necessary for the ama- teur woodworker to con- struct it by millwork meth- ods, as a satisfactory door can be made more easily. Glue together % in. thick white pine, bass wood or whitewood to make a board 2 ft. 3 in. by 2 ft. 11 in., the grain running the short way. Prepare two strips % in. by 2 in. by 2 ft. 11 in., and then have a mill man cut grooves along one edge of both of these, and along each long edge of the large board, so that the parts may be glued together with a tight maple spline in the grooves. You can, of course, cut the grooves yourself, if you have a suit- able plane. LOOS FOR EA T= E- PIN HINGES _5= (CH PART OF : By Everett Eames The lower door of this charming closet, with its triangular paneling, is reminiscent of the so-called Connecticut style of Colonial architecture, of which there are several examples in the Metropolitan Museum of Art, NewYork been clamped tightly and allowed to dry. Perhaps the upper door is beyond the abilities of a good many home workers, but one may be purchased already glazed from a millwork supply house. In this case the door cost $7.50. To build the closet proper, screw cleats to the wall after beveling them to receive the upright boarding. If you happen to strike a stud, only a few long screws are required, but if you are fastening the cleat HE panel effect is ob- only to the lath, use eight or ten 214-in. screws. ~ Place cleats also on floor and ceil- tained by gluing on °% in. thick pieces, as indi- cated. The dimensions ing. Erect four %-in. boards 8 given do not have to be followed exactly, but it is or 9 in. wide from floor to ceiling. Complete inclosing well to maintain about the same proportions. A quarter-round molding, in this case of oak, is boiled or steamed until pliable enough to be bent into place around the curved edge of the upper triangle. It is fastened with glue and brads. Use freshly prepared the closet by the “cut-and- RAISED PANEL SECTION OF DOOR CORNER OF ROOM —SS=>= = yor —H | =, BOARD = (FROM FLOOR TO CEILING) hot glue and have plenty of confidence in it, as it will not allow the parts to sep- arate when once they have DOOR CASING —+-7 2-6 -=— 10 Front and plan views of the closet and a detail of the lower door. The upper door is purchased from a millwork dealer fit” method, first making the top section of the wall over the door, then the casing, and lastly the shelves. Bear in mind that you are buildi the closet to suit the doors, The shelves, which are sup- ported on cleats, must be lined up carefully, so that their edges will correspond with the door divisions. In hanging the doors, use three or, preferably, four 2-in, loose-pin hinges. Ball-and. socket catches are the neatest type to use for the doors and are sufficiently strong. The color scheme of the room governs the painting of the doors and trim. Usually a cupboard of this kind is white or cream colored enam- el, or it is stained mahogany or walnut and varnished to match with the furniture The interior should be white. The wall surrounding the door casing can be sized and papered, or painted to match the walls of the room, and the picture molding and mop board carried around as cit cumstances require. If the builder wishes a secret hiding place, it is possible to leave a section d the top of the closet loose, so that small objects can be inserted into the space above. How to Resharpen Cutters of a Pencil-Pointing Machine O RESHARPEN the revolving cut ters of a standard pencil-pointing machine, obtain a %-in. wooden dowd about 4 in. long and sharpen as if it wer a pencil. Dip the pointed end into a mix ture of oil and fine emery and insert in the machine. Hold the stick stationary and turn the handle of the machine backward. Withdraw the stick when necessary t renew the emery and repeat the proces several times. When the cutters have been restored to their original keenness, wash off the oil and emery with gasoline —R. R. RunDELL. WueENn THE large blade of a jackknife i broken, the stub can be ground so as form asmall screw driver toward the back, where the steel is thicker. The thinne edge of the stub, if ground off square and left with a sharp corner, will serve for opening cans. A small notch in the stub will aid in scraping insulation from. the ends of insulated wires.—L. T. K. stc isf cal spi ne: inc the Alt the on pri fille tan of 1 tre bel sur ject wa} aba the ma’ yiel der: exc soft hav well the it x foot trer solic in. ¢ nex! surf, satis kept tren and wide boar with boar long then and stak flush

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July, 1927 aking the wall over ising, and Bear in building > doors, h are sup- must be so. that orrespond ons. loors, use four 2-in, Ball-and. re neatest loors and ng. e of the zinting of Usually s kind is ed enam- nahogany nished te furniture, be white ding the sized and to match 1, and the und =mop id as cir. et hiding section of hat small he space ers of hine ving cut -pointing en dowd if it were to a mix ert in the nary and ackward. essary to e proces ers have keenness, gasoline kknife is 1 so as bo the back, e thinne juare serve for the stub from K. July, 1927 POPULAR SCIENCE MONTHLY 75 eA Driveway for Your Garage How to Lay Concrete Tracks at Lowest Cost— Materials You Will Need— Making the Forms— Methods of Mixing driveways can be made of finely crushed stone, cinders, gravel, flag- stone, planks, and other materials, solid concrete ultimately proves the most sat- isfactory. Anyone, if properly advised, can construct his own concrete runways. Narrow runways, 16 to 24 in. wide and spaced 56 in. center to center, make a neat driveway. Dig the trenches a few inches wider and 5 or 6 in. deep. Tamp the bed thoroughly with a tamper made by nailing two handles to a block of wood. Alternately soak with water and tamp the ground until you can walk on it without leaving a foot- print. If the runways are being built on earth recently filled in, it is best to soak and tamp every day for a couple of weeks. The final bottom of the trench should be about 6 in. below the ground or lawn surface if the runways are to be flush, but there is no ob- jection to making the run- way surface an inch or more above the lawn. Large boulders should be removed if directly under the runway, as the concrete may crack over such an un- yielding point. Small boul- ders and gravel furnish an excellent base. In unusually soft ground it is desirable to have six inches or more of well-tamped gravel and stones to support the concrete. If the soil is spongy or marshy, it may be necessary to make “spread footings”’ by widening the bottom of the trench to 30 inches or so and laying solidly packed rock and gravel about 8 in. deep. Such conditions are rather rare. Mirveway more or less permanent SE cheap, green’ lumber for the forms, as it will warp less than dry boards. The planed surface should be next to the concrete. Boards 1 by 6 in., surfaced on one side and one edge, will be satisfactory; 1 by 4 in. boards can also be used, but the upper edge should be kept 6 in. above the bottom of the trench. Set the boards end to end in the trench and outside of them drive short stakes wide enough so that the ends of the boards can be nailed to them, each end with two sixpenny nails. From extra boards cut a dozen or more spacers as long as the runways are to be wide. Set them every 4 ft. Place stakes outside and nail the side boards to them. The stakes should be driven down or cut off flush with the top edge of the forms. By Roserr S. Lewis The spacers are removed just as the concrete is poured. The alignment and grade are obtained by establishing stakes at each end of the runway, with a wire or cord drawn tightly between. It must hang free from the boards in order to remain straight. By making the lines parallel to the house and extending them by sighting through, accurate alignment can be obtained. After the earth in the trench has been thoroughly tamped, the forms are filled with concrete section by section and then covered to protect the surface of the cement and to prevent too rapid and unequal drying Cement comes in bags of about 94 Ibs. each, approximately 1 cu.ft. It must be stored in a dry place. It is usually better to order just before using. Lumpy ce- ment, if it has not been exposed to damp- ness, can be rolled out or the lumps removed by hammering with a round stick. Lumps that cannot be crushed in the hand should be discarded. A great deal of poor concrete comes from a tendency to use the most available gravel and pebbles, some of which may be quite unsuitable. If sand is to be obtained in the neighborhood, test it by stirring in a glass of water; cloudy water and the presence of considerable sediment at the bottom of the glass, indicate too much loam and dirt. In general, it is necessary to buy suit- able sand. River sand is usually clean, but it is often too fine to use unless mixed with coarser sand. Sand that has an odor or soils the hands is quite unfit for concrete. Coarse aggregate makes up the large bulk of the concrete; this consists of gravel or crushed stone, for preference, or cinders, trap rock, and similar mate- rials. This aggregate must be free from dirt and clay. No stones over 2 in. long should be used. Never use shale or soft materials that tend to crumble. The total cubic feet occupied by con- crete is length multiplied by width, mul- tiplied by depth, all in feet. Thus a single runway 60 ft. long, 2 ft. wide and 6 in. deep contains 60 by 2 by 4%, or 60 cu. ft. The two runways contain 120 cu. ft. and, dividing by 27, the total volume of concrete is closely 4.5 cu. yds. The cuvic yard is the unit in which ready mixed concrete is always measured. Concrete of 1:2:4 mix is recommended for runways; this means a mixture of 1 cu. ft. cement (one bag), 2 cu. ft. sand, and 4 cu. ft. gravel. A 6-in. depth of this mix will carry ordinary automobiles and occasional fuel trucks with- out cracking. One “batch” consisting of a bag of cement with the necessary sand and grave! will make 4)2 cu. ft. of con- crete, which is 0.167 of a cubic yard. Six such batches make a full yard (27 cu. ft.). Spread out in the runway, a single batch will make 6.75 ft. of runway 16 in. wide, 6 ft. of runway 18 in. wide, 5.4 ft. of runway 20 in. wide, 4.9 ft. of runway 22 in. wide, and 4.5 ft. of runway 24 in. _ wide. A width of 18 or 20 inches ordinarily will be found suf- ficient, and 16 is considered the minimum. From these data the actual quantities needed for any width and length of single runway can easily be figured. Assuming, for example, a runway 60 ft. long, 18 in. wide, and 6 in. deep. One “batch” will make 6 ft. of length; 60 feet will, there- fore, take 10 batches, or a total of 10 bags of cement, 20 cu. ft. sand, and 40 cu. ft. gravel, which, when mixed, will make 45 cu. ft. of concrete, which equals 1.67 or 124 cu. yds. The two runways will re- quire 34 cu. yds. HE easiest way to mix concrete, one might say, is to buy it ready mixed. In some cities one can buy 1:2:4 mix and have it delivered. Even if only a richer mixture is available, tne saving in time and work will justify the slightly higher cost. This varies but usually is in the neighbor- hood of $6 or $8 a cubic yard, plus a charge for delivery. It is but little more than the materials cost and saves more than one half the back-bending work. A cu. yd. of 1:2:4 (Continued on page 92)

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How-to-Ma POPULAR SCIENCE MONTHLY July, 1927 ke Kinks for Campers Swinging Seat—‘Tuckaway’’ Bed —Fire-by-Friction Set— Airplane Weather Vane—Convement Anchor for Rowboat canvas chairs for comfortable seats when camping in the woods if you know the trick of making a swinging chair from light poles and, of course, are in a locality where there are no restrictions on cutting the necessary branches. A chair such as that illustrated at the right can be made in a few minutes from willow poles and hay wire. The seat is supported by two tri- pods, which are connected by means of a tie piece at the top. The crossbars which carry the swing will remain in place almost without support, but it is better to provide blocks or pegs to hold them or at least to lash them in position. The seat itself is made of lighter poles fastened together with wire as shown so as to be comfortably flexible-—W. CLark SANDERCOCK. Yen need not depend upon folding HE equipment of even the best- planned camp often falls short of accommodating unexpected guests. It is not difficult, however, to construct several folding camp beds and keep them on hand for emergency use. A serviceable “tuckaway” cot for this purpose can be made, as illustrated be- low, by preparing legs and rails of maple, birch, ash or other hard wood and assembling them with a length of 1%-in. gas pipe about 4 ft. 3 in. long, which serves as a pivot. The covering is heavy canvas about 30 in. wide. It is advisable to varnish the wood. OULD you make a fire by friction in an emergency as did Thorn- ton in the serial “Bare Hands,” now running in PoruLaR SCIENCE Montuty? It is always an entertaining and sometimes a very useful stunt for campers to know. A carefully made out- fit, such as Boy Scouts use for making fire by friction quickly, is not essential. Suitable ma- terials may be found wherever there is an accumulation of forest waste, although it is not likely you will be able to make a fire in record FIREBOARD 15"LONG AND 1° THICK This comfortable camp chair can be built with wood cut on the spot and a few yards of hay baling wire knee or foot. Make shallow holes in it and in the handhold, as shown below. String the bow with a pliable leather thong and “make fire” by rotating the drill briskly in the center of a small heap of any dry, inflammable material, such as inner bark, wood scrapings or dry grass. When smoke appears, add a little a —> Co time with them. Dried elm, birch, poplar or willow give excellent re- sults. The fireboard should be long enough to allow it to be held firmly with the 10” LONG DRILL %" DIA. AND AN EMERGENCY FIRE - MAKING OUTFIT Details of a simple homemade folding camp cot; an outfit for making fire by friction; an airplane weather vane; method of raising a rowboat anchor from the rower’s seat UNDERSIDE OF LEFT HANDHOLD WEIGHT EFFICIENT ANCHORING DEVICE tinder and fan gently. It is best & have a small groove running from the edge of the fireboard to the hole, g9 that air can be forced through it under the tinder. As soon as the tinder jg afire, transfer it to a larger mass of tinder and fine kindling. ° HICH way does the wind blow?” can be answered easily if an airplane weather vane, such as that illustrated, is doing duty upon a tall post in a summer camp or is mounted upon a boathouse, garage, barn or other building. It is a par. ticularly attractive form of vane fora camp because the whirring propeller gives such a lively and cheerful im- pression. Cut the body from a board % in, thick and fit a thin tin rudder in a slot at the tail end after tapering wood, as indicated below. Add the wing, and whittle the propeller, which is 8 in long, from soft white pine. Balance the assembly upon a narrow edge and at the center of gravity bore a hole to receive the pivot pin. Inserta steel ball in the hole so that the vane will turn with little friction. The letters are cut from tin and placed in slots in the letter arms, which are pieces of wood % in. thick, 2 in. wide at the center, 1 in. wide at the ends, and % in. long. They may be halved together or one may be simply laid across the other. The whole assembly should be painted in bright colors.—C. A. K A ROWBOAT anchor for the purposes of a fisherman is illustrated at the left. A heavy sash weight is used as the an- chor. It is tied to alength of sash cord; this is carried through a pulley attached 2 or 3 in. below the tip of the bow of the boat and through one or more screw eyes which are turned in along the inside of the gunwale. At the fisherman’s or rower’s seat is a cleat or screw eye to which the rope may be tied. With this arrange- ment it is not necessary to get up and go for ward every time the anchor has to be pull up. Furthermore, it al lows the anchor to be dropped instantly, _be- fore the boat can drift from a selected fishing place.—R. P. Lincou. Ul

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July, 1927 TS t ; best t from the hole, so it under tinder is mass of he wind swered une, such ity upon np or is garage, S @ par. ane fora propeller rful im- d % in. in a slot wood, as ing, and is 8 in, a, narrow rity bore Insert a vane will id placed hich are wide at s, and 2% gether or nply laid issembly nted in C. AK anchor rposes of lustrated avy sash s the an- » a length this is a pulley in. below »w of the rh one or »s which long the gunwale. nan’s oF , cleat or hich the d. arrange- lecessary go for- ime the e pulled re, it al yr to be tly, be -an drift 1 fishing LINCOLN. July, 1927 POPULAR SCIENCE MONTHLY 77 44 . y Fa. 4 » 7x pfs P * = A ~ =~"=7"" TOBACCO THE BEST PIPE SMOKE EVER MADE!” A VAST MULTITUDE OF PIPE SMOKERS in- stantly welcomed and praised. Old Briar. Thousands upon thousands claim Old Briar to be «‘the best pipe smoke ever made.’” The additional enjoyment, satisfaction and pipe comfort you get out of a pipeful of Old Briar costs but a fraction of a cent more than ordinary tobaccos. Wil {lh it os IF YOUR DEALER DOES NOT HAVE : . . . OLD BRIAR Light up your pipeful of Old Briar. Let the ripe fragrance of . * : : . Tear cut this coupon and mail to: Old Briar creep up your pipes stem. Enjoy every bit of its United States Tobacco Co., Richmond, Va. U.S.A. full, pleasant aroma — its rich body — its extra smoothness. ee aT ee Notice how mild and cool it is — how completely satisfying. mall you on receipt of this eoupon and Soe the regula . . . Old Briar 50c humidor box. In addition, we will include Then you will know why this wonderful tobacco continues to one 35¢ pocket package of Old Briar — extra — if you ia- = . 7 clude your dealer’s name. Send no money, but pay the win the praise of pipe smokers everywhere. postman 50c when he delivers your order. Tear out the coupon, now, while it’s handy! Generations of tobacco culture, years of selecting and of testing the finest leaf tobacco, of scientific mellowing and blending, ener ener ne ee have gone into the perfecting of Old Briar. IT ALL IR ann n-oncennnennsamnvensecer trian SHOWS UP IN THE SMOKE. City and State. ...--.-.-----.2-----0+e-e-0-eere-2"+ Weemee TRE FR ktc cn ccccnccsmescnacbsuananns TO DEALERS: Old Briar is sold in Pocket packages at 25c and Humidor boxes at 50c, $1.00 and $2.00. If your jobber has not supplied you, write us and we will send you a supply by prepaid Parcel Post at regular Dealers’ prices. If you prefer—send stamps, money order or check with coupon. UNITED STATES TOBACCO COMPANY. RICHMOND. VIRGINIA, U.S.A, IS} This seal on a radio, tool or oil burner advertisement signifies tte approval of the INSTITUTE OF STANDARDS. See page 6.

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POPULAR SCIENCE MONTHLY July, 1927 Hints on Using TAPS and DIES Cutting Clean, Accurate Threads by Hand—Reclaiming a Jammed Bolt—Tapping Oversize— Other Time-Saving Kinks NYONE whose mind leans to- ward things mechanical today realizes the great importance of proper screw threads in ma- chine construction and repair. Truly, the modern world is held together by screw threads. Realizing, as we do, that threaded con- struction is essential, what sort of screw threads shall we make? Loose fitting, ragged By F. S. BROWNING and the finishing or bottoming tap has practically no taper. The taper tap, with its smaller point, is easier to start in a hole, but can be used only in tapping a “through” hole such as on a nut. It is also used as a starter for the plug tap. The plug tap is the best tap for all What Is Wrong in This Picture? pipe fittings into which petcocks, drain plugs, and the like are to be inserted, They generally have a taper so as to permit a steam- or water-tight joint. The taps most useful to have in your repair kit are a set of machine screw sizes from Nos. 1 to 14, USS, hand plug taps from l¢ to % in. by sixteenths and from 5% to 1 in. by eighths, anda set of SAE taper taps from 3% to % in. by sixteenths threads, or clean. sharp threads, true in pitch and lead, fitting snugly together and resisting vibration? Ob- viously the latter. Many a machine has ended at the junk heap because of poorly cut, ill-fitting threads. The vibration that ruins many a machine originates often in loosely fitting threaded parts. Taps and dies are such commonly used articles in re- pair work on automobiles, tractors and farm imple- ments that: it seems strange to find many who have only a hazy idea as to their use and proper care. Also, there seems to be a great many mechan- ics who do not know how to get the most out of their taps and dies. Consequently these and % to 1 in. by eighths. Frequently certain taps are required for spark plugs. For the %-in. size, use a regular 4-in. taper pipe tap which has 14 threads to the inch, and with this tap use a Ye in. diameter drill. For the %-in. size use a special y%-in. tap which has 18 threads to the inch and with it use a 13¢-in. drill. Fora metric spark plug you will need a tap 18 m/m diameter by 1.5 m/m pitch. Almost everything _ that has been said about taps can be applied equally well to dies. Dies are of all kinds and shapes. They are used in stocks, which usually have some kind of a guide attach- ment. They are adjustable tools are subject to abuses which their importance should prevent them from receiving—in most cases sim- ply through lack of knowledge of their proper use. The taps most commonly used in everyday repair work are of two kinds, those for bolt threads and those for pipe threads. Hand taps for threading nuts are used to cut internal threads in which to screw bolts or other threaded parts. They sometimes are used in sets of three, taper, plug, and bottoming. These have different tapers (chamfers). The starting or taper tap has the longest taper; the following or plug tap has a shorter taper, You can see at a glance that this man is not going to do a very good job in tapping the hole through the piece of steel in his vise. are indicated. See if you can name them before reading the article around use. In addition to not being very difficult to start in a hole, it has a longer threaded portion than the taper tap and can be used where it is necessary to have a thread nearly to the bottom of a “blind” hole. A bottoming tap is used only where a thread is needed clear down to the bot- tom of a “blind” hole. The bottoming tap having practically no taper, cuts full size all the way and must be used after a taper or a plug tap. Pipe taps are for cutting threads in Five errors to size so that they can cut a little under size to allow for variation in fit as may be desired. The solid type of die has practically disappeared from use in late years with the exception of the hexagon sha die, which is used for rethreading jammed or rusty bolts. This is a very con venient die as it can be held in an ordinary monkey wrench (Continued on page 106) NM ANY time-saving shop ideas are contained in the continuation of the Better Shop Methods Department, to be found on: pages 104 to 10% Ju Bl Awe I

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July, 1927 cs, drain inserted, 0 as to pint. in your reWw sizes lug taps nd from is, and a ips from x teenths ghths. in taps ‘k plugs. , use a pipe tap s to the ap use & ill. For 1 special has 18 ind with For a you. will liameter ig that taps cal well to Il kinds ure used lly have - attach- justable can cut to allow as may uctically urs with shaped ireading ery COn- yrdinary page 106) eas are ation of rtment, to 109. July, 1927 POPULAR SCIENCE MONTHLY 79 “Wish I had one Starrett Combination Builders Tool No. 439 ‘Well — wishing won’t get you mine, big boy. They’re the handiest tools in my kit. Better get some of your own next pay day — you’ll wonder how you ever got along without them.” The Starrett No. 94 Combination Square is eight tools in one. ; . ie. It combines a Marking Gage, Rule, Try-square, Miter, Depth Gage, Starrett Combination Height Gage, Level and Plumb. Square No. 94 The Starrett Combination Builders Tool No. 439 will save you a heap of figuring if you’re doing any roof construction work. Ask your tool dealer to show you these tools. Write us for free copy of Catalog No. 23 W describing over 2500 fine tools. Starrett Universal Scraper No. 194 Here’s a scraper with eight sharp cutting edges. The ends of the blade are ground square and any one of them can be brought into use by means of the ball joint. The spring plunger makes the ball joint easy to adjust to any desired angle. THE L. S. STARRETT CO. © World’s Greatest Toolmakers Manufacturers of Hacksaws Unexcelled Steel Tapes—Standard for Accuracy ATHOL, MASS. Starrett Universal Scraper No. 194 Use Starrett Tools IS} This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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. eee tenes

a ‘ ‘ ‘ =_~ \ You SimplyBrushItOn / a The fact that you never have painted or never could paint means nothing now. Rogers Brushing Lacquer is an entirely new and different proposition. No expert ability or experience is required. Any average man or woman can use “Rogers.” It isn’t ae on. No long, careful brushing out is required. ou simply flow it on with a full brush.'Then you sort of spread it out. “Rogers” forms a wonderfully smooth, satiny coating of brilliant color, right over the old finish. Then it Dries while you wait! Dries in30 minutes or less. Dries free from laps or brush marks. Dries before dust can mar it. Dries in time for any urgent need. Dries toa smooth, porcelain-like color- ful finish that wears and wears and WEARS. Does not print or gather lint. There are scores of things in your home that will need brightening up for summer. A few are suggested on the opposite page. Try. this wonderful Rogers Brushing Lacquer. See how simple it is. There are hundreds of other uses in every home, store, office, factory and building in many industries. Dealers everywhere now sell and demonstrate “Rogers.” Comes in cans, ready for use, in 18richcolors, also, black, white and clear. To insure eta results in- sist upon the genuine in the ‘“‘Oriental” oe. cr Ss ites ee Dry in “ae iki 40 Minutes » OR LESS yan.

99 Our ‘‘ Money-Back” Guaranty Try one can of Rogers Brushing Lacquer. If not more than satisfied, return what is left to your dealer. He is authorized to refund the entire purchase price

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LACQUER IT ORY~30 CAINDTES \ \ VT. i e >a a *» ose be ee “™ a — ‘Cap BRUSHIN LACQUER

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; eo have improved. but- what about gasoline? Ir IS a far cry from the “horseless buggy” of yesterday to the automobile of today. But the first cars and the latest cars are alike in one fundamental respect: doth depend on gasoline for fuel. Gasoline is not a perfect fuel. It has always had one inherent fault. It explodes too quickly (“knocks”) as temperature and compression increase. Carbon increases both temperature and compression beyond the point at which the present day automobile is designed to operate efficiently on regular gasoline. And the full efficiency of the modern motor car and its continued development have both depended upon the discovery of a “knockless” fuel. After eight years of experiment, General Motors Re- search Laboratories developed Ethyl brand of anti- knock compound, a chemical ingredient which leading oil companies are mixing with their regular gasoline to form Ethyl Gasoline. Ethyl Gasoline is ¢he efficient fuel for automobiles of today and tomorrow. This super-gasoline will give your engine a performance such as you have never known. It is available throughout the United States and Canada and is sold at pumps which display the “ETHYL” trade- mark. Try it today. Eruyt Gaso_ine Corporation, 25 Broadway, New York ETHYL GASOLINE BES WS SSPEE_LSSETE_ZS SS em rs wat OTN OTTO. . eS CET IOS z ae, » o

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July, 1927 POPULAR SCIENCE MONTHLY . $1 Hammering a Porch Lantern How to Make a Hanging Lamp of Unusual Simplicity and a Bracket for It—Coloring the Copper By Dick Hutcuinson distinction and beauty are high. This tempts many an amateur me- chanic to make one himself, but unless the method of construction is well under- stood, there are bound to be discouraging bumps. —_ For several years I have been building lanterns of many styles, but I can’t make them for everyone, so I am passing along this design so that the other fellow may get a little pleasure out of making one for himself. This lantern is really a most interesting hand hammered copper piece, and it is simple to make. The tools required are an 8-0z. ball peen hammer, an anvil or any smooth surface block of steel or iron, a vise, a pair of cutting pliers, a file, and a pair of tin snips. Before beginning, buy at a hardware store one of the short type of ordinary barn lantern globes, which is approxi- mately 414 in. high over all. Obtain also asheet of 16 or 18 gage soft copper. To make the cap, draw a circle 75¢ in. in diameter on the copper. Draw a line from the center to the outer edge. Then, measuring to a point 314 in. straight across from the outer end of the first line, draw another line to the center, and a third line 14 in. within and parallel to the last. With the tin snips, cut out as shown in one of the accompanying drawings. Clean up the flat end of the ball peen hammer by rubbing it over a piece of jeweler’s fine emery paper until there are no scratches. Lay the cap piece on the anvil and hammer over one side only. Pisin for porch lanterns of real HANDLE ELECTRIC FIXTURE BUSHING oe Mr. Hutchinson dem- onstrates how to ham- mer the cap of the lantern into a cone shape by holding it at a slight angle to the anvil. The fnished lantern is shown above Then turn the piece over, and, holding it at a slight angle with the anvil, hammer it carefully into a cone shape. Hold the piece slightly raised on the anvil, and work around the inside with the hammer, beginning at the outer edge and working back and forth toward the center, ham- mering just enough to bend, but not enough to expand the metal. Continue until the gap is closed. Next, drill three holes in each side, and, forcing over the lap, rivet together with No. 14 brass escutcheon pins. These should be driven in from the outside, cut off close to the metal, and headed on the inside. They make very neat rivets. The top rim should be lg by 13% in., with four Y-in. lugs, equally spaced, so that when the piece is formed into a hoop they will balance. Hammer this piece on one side only. Drill a hole in each of the lugs; then bend the strip into _aloop. This is done by placing a bar of round iron of any size in the vise and gradually shap- ing the hoop over this witha hammer. The barI use is 1 in. in diameter. Fit the hoop over the rim on the large end of the lantern globe, drill holes at each end, and rivet together. The bottom rim, which is 14% by 12% in., is made in the same ROUND copper WIRE 18” LONG = manner except that it has no lugs. This should be fitted to the small end ~ 13%- ' How the parts for the lantern are cut out and assembled, and & bracket of suitable design from which to suspend the light of the globe. The base is a 31-in. disk with four \-in. aE lugs, which should be drilled and bent down at right angles. The base should not be hammered unless it is necessary to fit it into the bottom rim tightly after having been riveted into place. The four ribs are % by 94% in. Ham- mer on one side only. Drill.one hole 4% in. from the end of each; then, with a pair of pliers, bend the other end as is shown in one of the drawings. This is done by measuring 1 in. from the bottom end of the rib and bending over at this point. Drive down with the hammer, measure ¥% in. farther, and bend back sharply to an angle of about 45 degrees. Then shape the rib with the pliers as indicated. Have the hammered side face outward. The handle is a piece of 44 in. round copper wire, 18 in. long, hammered all over, and bent as illustrated. A hole should be drilled in the center of the cap large enough to admit a \%-in. fixture bushing, and the top filed off smoothly so that the bushing will fit down snugly. END the four lugs on the top rim in until they form the same angle as that of the cap. Turn the cap upside down, and set the top rim in and center it; mark and drill holes in the cap to line up with those in the lugs. Then rivet the rim to the cap with No. 14 escutcheon pins. Center and drill four holes 4% in. from the bottom of the top rim at equal dis- tances apart and rivet the ribs in place. Drill a 14-in. hole in the center of each side of the top rim, and spring the handle into these. Center and drill holes 4% in. from the bottom of the bottom rim to correspond with those in the lugs on the base. Drive the base up into the rim until the holes line up, and rivet. Wire a keyless (Continued on page 86)

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PocketGen for the man on the job! HE man on the job wants to know the truth about the time. He needs a sturdy, steddy watch—an accu- rate time-keeper that will stand rough-and- tumble everyday use. Pocket Ben is that kind. Sold everywhere for $1.50. With lumi- nous night-and-day dial, $2.25. WESTERN CLOCK COMPANY La Salle, Illinois

esr Yz2s © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. POPULAR SCIENCE MONTHLY July, 197,

Replacing Jackknife Handle How to Shape Them from Wood and Finish Them to Imitate Stag, Bone or Celluloid

By CHELSEA FRASER ANY a man wears out his pockets and suffers sundry slight abrasions of his hands be- cause a cherished pocketknife has a broken handle. Yet almost any dark-colored handle, whether cellu- loid, stag, bone or wood, can be duplicated successfully with the simplest tools and materials. Even light-colored handles, if made of wood, are easily replaced. Any small scrap of wood will be sufficient for making the new han- dle, provided it is straight-grained and firm in texture. Maple, beech, birch, magnolia, walnut, mahogany

and gumwood are suitable. Carefully remove the broken sec- tions by splitting them, if wood; cracking them, if bone; and softening them with a hot iron, if celluloid. Avoid reducing the length of the rivets, but file off the burred edges around their heads. Force a strip of stiff paper over the rivets and trim to make a templet for the new handle. Plane the wood for the new handle to }@ in. thinner than the old handle so as to allow for reheading the rivets. Trace the templet on it, mark and drill the rivet holes, then cut out the new handle. Shape it with a knife, chisel or cabinet file, frequently pressing it in position to compare its convexity with the bolsters at the ends of the knife. Black ink may be used to stain a new wooden handle, if followed by several coats of thin shellac Finish with No. 1 and No. 14 sandpaper, In riveting a new handle in place, insert) an old mill file or several case knife blades between the brass lining plates to act as an anvil. Rivet lightly so as not) to split the wood. If the rivets still pro. ject slightly, file them flush with the! wood. Smooth the new handle with No. | sandpaper. Use a small gouge or 4) leather punch to make indentations in imitation of staghorn, if necessary. Then stain the wood, rub briskly with burlap) when dry, and apply several coats of thin shellac. Rub the last coat with powdered pumice stone and oil on felt.

2 In coloring wood, either ° fabric dyes or thin enamd

PAPER TEMPLET 4 MADE FROM IMPRESSION = HANDLE (CONVEXED) RIVET—y ’ SSS / SS SEEEEE ESSE or brushing lacquer may kk used. Mottled effects may be obtained by applying a plain undercoat and stip) pling on a second color after the first is dry.

WHEN a number of irregi lar curves have to be drawn, a flexible ruler can be made. by incasing a strip of lead about \ in. thick and 4%.

IMITATION STAG The steps in making a new pocketknife handle and fastening it in position with the same rivets that held the old handle BENCH TOP” ‘a or 3% in. wide in a thi rubber tube. This will hold its shape however it B bent.

Rubber Cement Mends Torn Hunting Coat Invisibly UBBER cement may be used for repairing tears in clothing, as I dis- covered on a hunting trip recently. A large three-cornered tear in a new coat was patched invisibly by turning the cloth inside out, applying a small quan- tity of transparent rubber cement near the edges of the tear, and covering the damaged area and cement with a smal piece of cloth. A weight was placed on) the cloth until the cement dried and later) on, at home, a warm flatiron was mul over the patch.—A. S. JAMIESON.

For CLEANING the bore of a pipe, I have! found nothing better than a gimlet bit which can be obtained at any hardwart) store for a few cents. A size should be! chosen that is a trifle larger than the) diameter of the bore.—A. P. A. |

Jul I a b 0 b a s

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July, a July, 1927 POPULAR SCIENCE MONTHLY 83 a You hear woug = for Electrol v h em —— pias In the homes of owners....In offices . . On the street . . Always words of praise wooden n shellac sandpaper, ace, insert sase_ knife x plates to SO as not s still pro with the| th No. 0 uge or a tations in ary. Then ith burlap | coats of coat with stone and od, either ‘in enamel er may be fects may ipplying a and stip ond color ry. of irregt be drawn, h a small placed on 1 and later 1 was run N. pe, I have zimlet bit.) "hardware! should be than the — Listed as Standard by the Underwriters’ Laboratories, and bears its label. Approved by the New York City Board of Standards and Appeals—and by the Commonwealth of Mass- achusetts Department of Public Safety, “ran The Master \ \ j | Furnace Man | for this modernized oil burner, othe most talked about oil burner in America! In what owners say about Electrol lies the answer to Electrol’s rapid rise in public preference. Men who know fine engineering, and who have successfully heated their homes with Electrol for years, are enthusiastically recommending it to their friends. The Master Control, found only on Electrol, is a feature you will not care to be without. This wonderful device constantly safeguards your comfort like a living sentinel watching over the burner’s operation day and night. It watches the supply, the flow and the burning of the oil, and every fac- tor of Electrol’s all-electric, entirely automatic operation. Ignition is instantaneous and posi- tive. No gas pilot light is needed. The oil is atomized into a fine mist and ignited directly by electricity. Low air velocity insures extremely quiet operation. Regardless of the type of heating plant in your home, Electrol will eco- nomically add comforts, conveniences and heating certainty, worth many ‘imes its cost. Send for this book “The Master Furnace Man”’ is an enlightening book containing much valuable information on the proper selection of an oil burner. Callon the Electrol dealer in your locality. He will gladly make a conscientious study of the heating requirements of your home, without charge—and explain the attractive Electrol budget payment plan, a sxe ELECTROL INC. of Missouri 7: a 4 180 Dorcas Street, St. Louis, U. S. A. Ps 7 $ i af ae eS ee ee oes Rs 18 fe ze" Tx Oe = a or Pa The OIL BURNER with The Master pene ee Ss CLIO S. © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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Pipe Smoker Finds the Right Tobacco for the Tropics Evident!y, one of the problems of pipe smokers who live in the tropics is to find a tobacco that high temperature will not spoil. Mr. R. G. Rigg of Colombia, S. A., was happy to find that he could enjoy in South America the same tobacco that had been his favorite since 1908 when he lived in Towa. His letter follows: October 6, 1926 Larus & Bro. Co. Richmond, Va., U. 8. A. Gentlemen: Most all ‘well-known tobaccos smoke well in a cold or temperate climate, but very few in a tropical climate. They are mostly too heavy, don’t seem to blended right—at least that is my opinion gained from practical experience. However, Edgeworth is the same in any climate. Again that is my opinion gained Ry penction’ experience. cannot get the same pleasure out of any brand of tobacco that I can out of eworth, and I have tried many—and paid fancy prices too. It costs real money to smoke imported tobaccos here; the im- port duty is very high. Anyway, we cannot have everything we would like in these countries, so we hold on to all the little pleasures possible. Now you know why I smoke Edgeworth. Yours respectfully, R. G. Rigg, Cartagena, Colombia, S. A. Let us send you free samples of Edge- worth so that you may put it to the pipe test. If you like the sam- ples, you'll like Edge- worth wherever and whenever you buy it, for it never changes in ee quality. Write your name and address to Larus & Brother C om - pany, 10 S. 21st Street, Richmond, Va. We'll be grate- ful for the name and address of your tobacco dealer, too, if you care to add them. Edgeworth is-sold in various sizes to suit the needs and means of all purchasers. Both Edgeworth Plug Slice and Edgeworth Ready-Rubbed are packed in small, pocket- size packages, in handsome humidors hold- ing a pound, and also in several handy in- between sizes. To Retail Tobacco Merchants: If your jobber cannot supply you with Edgeworth, Larus & Brother Company will gladly send you prepaid by parcel post a one- or two- dozen carton of any size of Edgeworth Plug Slice of Edgeworth Ready-Rubbed for the same price you would pay the jobber. 4% 1 radio—tune inon WRV A, Richmond, Va. Edgeworth Station. Wave length 256 meters. POPULAR SCIENCE MONTHLY July, 197 Flaming Letters Light Camp i) Bottles Used As Lamps. ‘in Making Novel Sign By J. V. Hazzarp UD TOLSON bolted his supper and fell to rum- maging through his dunnage chest, whistling the while. His search pro- duced cold chisel, hammer, pliers, a small lamp wick, and a length of %-in. iron wire. The litter under his tent yielded an ordinary pop bottle and, after a search, a top for it. This he laid on the tent floor, slot- ted with the chisel and threaded with the lamp wick, after turning and pounding down the rough edges of the cut. Kerosene to half fill the bottle he poured, with a grin, from his neighbor’s lamp. A hook for hanging he accomplished by twisting a piece of wire snugly, but not tightly about the bottle neck, bending a hook in the end left projecting for that purpose. Darkness fell before the job was fin- ished. Jud hung the completed flare on his wire clothesline and touched a match to the wick. There was a small light, accompanied by a heavy black smoke; then a long waving tongue of flame lit the whole back of the tent. ay J FOR ANGULAR FLARES pes INDENTATION FOR en! ee HORIZONTAL WIRE Bottles which hang one above the other are supported at an angle so that the flame of one will not fracture the bottle directly above. All other bottles are merely hooked over the horizontal wires in positions marked by slight bends, which keep them in place “Hey! What the hunk you doing!” yelled a voice from the next tent. Jud’s invitation to come and find out was in- terrupted by the arrival of half the camp, bucket in hand, for tents have a habit of burning with surprising alacrity and sea- soned campers know the folly of hesitation. Order being restored and the flaming bottle deposited at a safe distance, Jud found opportunity to explain his plan. Opening night found the Crescent Canoe Club fairly buzzing with life and Wires strung between posts support kerosene-filled bottles, which are arranged to form one or more letters, as desired color. Canoes came and went, sporting new fittings, new varnish and new ladies, Music floated across the water from the mess tent where the floor had been cleared for dancing. Flags and Jap lanterns festooned tents and trees. Darkness came slowly and softly. Withit came a fusillade of shots from a line of figures dimly out- lined along the water front. At the far right a torch flared, then another, and another, until there blazed against the blackness a tremendous “C.”’ There fol- lowed the crash of another volley and “R” flamed, a bit smokily at first and then steadily. Volley followed volley and letter after letter the name of the Club appeared, outlined in flaring letters across the eighty-foot frontage of the camp. A long round of applause followed by a rush for the canoes signified the appreciation of the guests. The view from the river proved even more striking, “But, how did they do it?” Even the old-timers along the river asked the question. Morning found the curious gazing ata peculiar arrangement of tall posts and tightly strung wires. To the rustic fence fronting the camp were secured 8-foot posts spaced at 10-foot intervals, the tops being joined by tightly stretched wire; 2 feet below this stretched another wire and 2 feet below, another. The three parallel strands were joined with lighter pieces on which appeared loops at regular intervals. “That’s what the lights hang on al right,” observed one, “but where and what are the lights?” It goes without saying that no one guessed, but when, a week later, the sign made its reappear} ance in honor of the Commodore’s bi day, the Crescents were obliged to tél] the story of “Jud’s blaze of glory” 0) several score enthusiastic and envious) campers. A deal of planning had been necessaryil Where flares hung (Continued on page 8) IS} This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. July, | per a su the _| 8-in. 12-1 fact sav high insté men spac for t 14 | from able.

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ttles, sired , sporting ew ladies, from the en cleared lanterns ness came a fusillade limly out- \t the far ther, and sainst the There fol- olley and first and ed_ volley ne of the ing letters ze of the e followed nified the The view e striking. Even the isked the azing ata posts and he rustic e secured intervals, - stretched d another The three ith lighter at regular ssiameneiiiiatin ing on all vhere s without but whe, reappear re’s birth-| ed to tel} glory” d envious necessary: on page 85) July; 1927 ——— Flaming Letters (Continued from page 84) rpendicularly one above the other it had heen found necessary to guy them out to 3 supplementary wire as indicated, else the heat from the lower flares fractured those above. Originally the flares were placed at gin. intervals, but later it developed that ‘| 1¢-in. intervals produced just as satis- factory results and effected a considerable saving in fuel and labor. Letters 3 ft. high, with a corresponding saving in fares, would be large enough in many instances. Indeed, the suggested arrange- ment illustrated below is based upon 3-ft. spacing rather than the 4-ft. letters used for the canoe club sign. It was found that the sign would burn 14 hours continuously, or two evenings from dusk to midnight without refilling. Two miles away the sign was easily read- able, having all the appearance of an electrically lighted affair. Once in use the flares served various purposes. The landing float, projecting some twenty feet from shore, had been rammed occasionally by motor boats and r % Pk WIRING AND \ FLARES FOR THE LETTERS R-E-C-N> — i“ > . f { Method of spacing bottles for letters 3 ft. high. The flares are placed 12 in. apart unwary canoeists, so it became the practice to light the outer corners with lanterns. In one way or another we managed to kick one or other of these overboard about once a month. With the advent of the flares a hole was cut in the decking of the float just over the beam forming the front member of the frame- work at these corners and, with its bottom resting on the beam and neck and top projecting a scant 4 in. above deck, the flare served all purposes. They also proved valuable in lighting up dark corners where illumination with- out brilliant light was desirable and two or three judiciously hung about the camp site before turning in for the night assured sufficient light to distinguish inquisitive prowlers from members of the club. Preparing Ground Glass in an Emergency HEN a small piece of ground glass is required, as to replace the ground glass of a camera, and the commercial product cannot be easily or immediately obtained, it is possible to prepare a piece of plain glass by rubbing it with fine emery paper lubricated with a few drops of thick - By bearing down on the glass with moderate pressure and adding oil from time to time, one can prepare a small plate with relatively little effort.—L. D. S. —— POPULAR SCIENCE MONTHLY Pesky little screws are easy with > r 4 x m me z ° oO 85 While left hand holds work, and right hand holds driver steady, you start screw with thumb-turn on blade. “YANKEE” No.15 R with this handy Ratchet Screw- driver you can start wobbly screws quickly by revolving Knurled Washer + > z Az m m z i] a with thumb and forefinger. how useful! Ratchet Screw-driver. No. 10—Without thumb-turn. Eight sizes: 2 to 12- inch blades. No. 11—Same as No. 10, except ratchet shifter moves across tool. Some Other *“*Yankee”’ Tools Plain Screw-drivers Automatic Push Drills Spiral Screw-drivers ~ Feed Bench rills Ratchet Bit Braces Ratchet Tap Wrenches Ratchet Breast and Vises—Removable Hand Drills Base Dealers Everywhere Sell “Vankee”’ Tools “‘Yankee’”’ on the tool you buy means the utmost in quality, efficiency and durability. Nort Bros. Mre. Co., Philadelphia, U.S. A. “YANKEE TOOLS © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDAR®DS. See page 6. Then you send screw home in a jiffy by Ratchet Movement. How simple— Right and Left Ratchet, and Rigid. Saves time and strength. Ask your dealer to show you the ‘ Yankee” No. 15—With “Yankee” thumb-turn on blade. Ratchet shifter moves lengthwise. Six sizes: 2 to 8-inch blades. FREE New ** Yankee” Tool Book This interesting little book is for all lovers of fine Tools. It tells just what you want to know about all the famous “YANKEE” Tools for making work easier and quicker. °

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POPULAR SCIENCE MONTHLY July, i9y better Cheney Hammer for finishing | work Carpenters them- selves are respon- sible for the slick new features of the Cheney Fin- ishing Hammer. They knew what they wanted in a good finishing hammer—and said so. Cheney did the rest. The Cheney Finishing Hammer has the same fine Cheney tool-steel head that’s been tem- pered to stand the gaff and the same wonderful Cheney “hang” that means a whale-of-a-lot to a man at the end of the day’s work. Addedto these features is a new, slender, second-growth hickory handle with a real spring in it. It re- bounds from finishing work without marring it andactually fits in a man’s hand with honest comfort. Your first job with a Cheney Finishing Hammer will tell you the story better than we can. Try one. Building a Sturdy Porch Swing IX MAKING this porch swing, it is essential to use oak or some other hard, strong wood. The stock may be cut to the following thicknesses and ° widths and dressed at a woodwork- ing mill. Two bottom rails 134 by 3 by 78 in., one back rail 134 by 6 by 68 in., one back rail 134 by 4 by 68 in., two back posts (a) 13% by 134 by 22 in., and two front posts (b) 134 by 314 by 914 in., two arms 134 by 4 by 2214 in., two furrings (c) % by ¥% by 914 in., four cushion supports (d) 4 by 2% by 19 in., or use only two and make them 4 in. wide (ve erified for length), and fifteen seat slats 7 14 by 4% by 23 in., eight back pieces 4 by 45% by 20 in. and six 14 by 44 by 21 if in. Eight lag screws zs by 6 in. and twelve 3; by 5 in., with washers; 2 Ibs. fourpenny nails; chain; stain and varnish. The nails should be staggered as indicated (e) to avoid splitting. The chain holes (f) should be bored with a %%-in. bit.—C. K. is Straight lines and simple construc. tion are the main © features of this | swing. The wood p is stained and given — two coats of varnish 4 | Ms Top, front and end views of the swing, which is assembled entirely with lag screws and nails. All sharp corners of the frame are planed off and the seat corners rounded before assembling How to Hammer Out a Porch Lantern (Continued from page 81) porcelain socket with weatherproof wire, and slip the wire up through the bushing in the top of the lantern. Screw the bush- ing into the top of the socket. Allow enough wire to reach from the lantern, through the bracket, and to the outlet box for attaching to the service wires. Slip the large end of the globe into the top rim, place the bottom rim over the small end of the globe, and spring the ribs into place over the edge of the bottom rim, and the lantern is complete. The bracket illustrated is a simple one to make. The plate is cut from the same stock as the lantern—5 by 14in. A %-in. square is cut out of each corner and the piece is bent up into a box shape. A 3-in. hole is drilled through the center for at- taching to the outlet box, and above this, another hole is drilled to admit the wires. The arm and bracket are made of %-in. copper, 1 in. wide, and riveted together and to the plate with escutcheon pins. The ring is an ordinary fixture loop, held in place by a \%-in. hexagon fixture bum) The whole piece may be left a coppe or natural color, or, if desired, a pet manent reddish brown may be obtained by heating the finished metal slowly with a blowtorch. Care must be taken, hor ever, not to overheat it or a scale form and spoil the effect. A verd green seems to be the mot) popular finish. To produce this, mill about 5 oz. commercial nitric acid in 1q@ water in a glass or earthen bowl. [it merse the pieces to be colored in t solution, remove immediately, and h up where they can remain for five or# days. This formula is worth remembt® ing, as I spent a lot of time and mon before I finally succeeded in producing satisfactory verd green. It works eq well on brass and copper. With any of the above finishes, iti well to go over the entire piece wi good floor wax; this will preserve @ finish and resist the weather. f © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. july,

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lines and — onstruc- ~ the main — of this The wood © and given ~ of varnish — aie Ah oe | nd nails. f embling | ; | xture bum! ft a copper ‘ed, a pe ve obtained slowly with} aken, how . scale will > the most; this, mil) vcid in 1 qt) owl. Tn} red in ti , and h - five or remember and mone »roducing rks equal ishes, it iece with# reserve # july, 1927 Mier Decorative Galleon Has Walnut Shell Hull = galleon illustrated is made of a walnut shell with toothpick spars and stiff brown wrapping paper sails. Fore- castle and poop are of writing paper, and deck, keel, cradle and base are from a correspondence card. Gilt borders and designs from Christmas cards, pieces of cigar bands and the brilliant tissue paper lining of envelopes furnish material for the decorative touches, figurehead and banners. No rigging is necessary. The half shell is turned open side down on the correspondence card while a light cil line marks the shape of the deck, which is then cut out and glued in place. Cutting the keel is a case of fit and try; the cradles are formed the same way. A walnut galleon on a stand and another about ready to set sail in an aquarium These are glued to the hull and the base attached to the cradles. The decks and sides of forecastle and poop are made in one piece; the ends are separate pieces. Masts and bowsprit are stepped by poking needle holes through superstructure and deck and forcing the toothpicks through the holes. Sails are cut and glued to the spars be- fore the latter are attached to the masts and, after the glue has set, are given a realistic curve by rolling around a pencil. Ladders leading to the poop deck may be marked off with black ink and the rudder post is represented in the same manner. With the addition of a half dozen bird shot for ballast and a coat of shellac, a nut shell galleon will ride the waves of an aquarium.—J. V. H. How to Lock a Dial Telephone Against Unauthorized Use O PREVENT unauthorized calls being made on a dial tele- phone, especially one located in an office and acces- sible to anyone after business hours, the instru- ment can be locked by using a light padlock as shown. In one large office this has reduced the telephone bills $50 a month. The phone May still be used to answer incoming —Irvine L. HoLLANDER. tes Padlock prevents dial from being turned POPULAR SCIENCE MONTHLY Men Are Changing By Scores of Thousands From old-type shaving soaps to this unique creation—let us send you 10-day tube to try GENTLEMEN: 80% of the present users of Palmolive Shaving Cream once were wedded to rival prepara- tions. Millions have discarded old-type shaving soaps for it. We won them over by giving them liberal test tubes of this unique creation to try. Then asked them to compare with pres- ent favorites. ~ Now we seek a like opportunity of proving results to you. We believe you'll find that 5 major mistakes in shaving prep- arations have been corrected. And shaving thus given a new element of comfort, speed and pleasure. These 5 advantages 1. Multiplies itself in lather 250 times. 2. Softens the beard in one min- ute. 3. Maintains its creamy fullness for 10 minutes on the face. 4. Strong bubbles hold the hairs erect for cutting. 5. Fine after-effects due to palm and olive oil content. Let us prove this We ask your permission to prove these things—to send you a tube to try. We are masters of soap making. One of our soaps— Palmolive—is the leading toilet soap of the world. We have worked hard to excel in a Shaving Cream. We made upand tested 130 formulas before we attained our ideal. Co us the kindness to mail this coupon, for your sake and for ours. THE PALMOLIVE-PEET COMPANY, CHICAGO, ILL. li PI 0: 10 To add the final touch to shaving luxury, we have created Palmolive After Shaving Talc—especially for men. Doesn't show. Leaves the skin smooth and fresh, and gives that well-groomed look. Try the sample we are sending free with the tube of Shaving Cream. Here are new de- lights for every man. Please let us prove them to you. Clip coupon now. 3616 PALMOLIVE & * SHAVES and a can of Palmolive After Shaving Talc Simply insert your name and address and mail to Dept. B-1355, Palmolive, 3702 Iron Street, Chicago, Ill. Residents of Wisconsin should address Palmolive, Milwaukee, Wis. FREE oe * Ghiia giles pean iaaeradh abaecale aren “566 © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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POPULAR SCIENCE MONTHLY July, 19 AAS Rh hk Le ; “GiveMeA ® Cigar, Please’ You don’t hear men ordering cigars that way—not if they know anything about them. They know the kind they want and ask for it. When you ask wrench, tools. has are used. speci more than wrench.” The pressed steel frame of a breaks. Sharp new jaws can be inserted when the old ones get dull. The nut guard keeps a TRI- MO from being knocked out of adjustment. TRI- MO users know that these features are worth demanding. If you want a pipe wrench or monkey wrench, let it be known you want a TRIMO. But don’t keep it secret. Always specify TRIMO. TRIMONT Manufacturing Co. ROXBURY (Boston), MASS. America’s Leading Wrench Makers for Nearly Forty Years oieieeeeneeeniiiteieimmetil vrvvvrvy~wrewvy 3 The same can be said of tools. your dealer for a TRIMO he realizes that you know good pipe For the name TRIMO won re- spect wher- ever such tools The man who fies TRIMO gets “— @est «4 TRIMO never TRI- MO’S jaws arerenewable. How to Apply Art Transfers (Continued from page 73) more formal decorative work. Other classifications from which one can choose are conventional designs, which are for the more formal pieces; oriental designs re- sembling the work of Chinese and Japa- nese artists, especially desirable for red or black lacquered radio cabinets, secre- taries, chests, telephone stands and so- called occasional pieces in oriental color schemes; landscapes, for rather ornate painted furniture in period designs, and Colonial designs, which are now enjoying great popularity. If you decide which of these classifica- tions is most appropriate for the piece you wish to decorate, you will find the process of choosing appropriate transfers will be much easier than if you make a hasty and haphazard hunt through the large variety of samples of all these types which you will be shown in any well-stocked shop. In addition to these classifications, thereis another type of transfer in- tended especially for use over natural fin- ished furniture, which gives the ef- fect of inlaid band- ings and inserts. So perfect are some of these that it is al- most impossible to tell them from actu- al inlays, although they can be obtained for a fraction of the cost and _ require none of the skill which genuine in- laying calls for. When you have decided upon the type of design you wish, make up your mind as to the approximate size. It should be proportionate to the surface on which it is to be applied. The tendency is to select a design that is too small. The shape, too, should correspond to the surface on which the transfer is to be used. Your good taste will govern in selecting the coloring.. If you can take a small sample of the background color with you when buying transfers, it is a simple matter to choose. OME aarticles can be decorated with almost any type of pattern. A magazine rack, for instance, would be in good form decorated with any motif with the excep- tion, perhaps, of fruit. -Breakfast sets are generally done with four corner designs. Card tables and other small tables often have a central design combined with corner pieces and occasionally a narrow border is run entirely around the table top or connected with the corner designs. Lineal borders are obtainable for this purpose in 2-ft. lengths. You will find that the back of each transfer usually is marked with vertical and horizontal guide lines. These are to aid you in centering the design and apply- ing it exactly horizontal or vertical. If there are no guide lines, trim the top of the transfer paper to a straight edge just above the design and mark the vertigs center line. Make careful measurements before plying transfers and upon your eye. The best design will ng be satisfactory if off center or crooked, A: quick-drying varnish js a a do not rely m ideal adhesive for transfers, as it; elastic and does not cause puckering, Th. various proprietary adhesive cement made on a varnish base also are y excellent. A good grade of liquid glues often used by home decorators because} is so convenient; its adhesive propertig are entirely satisfactory, but there 5 some tendency for glued transfers to dry and pucker up while drying. Apply a thin, even coat of the adhesiy selected to the face of the transfer, cove. The surface is cleaned first with clear water, then with gasoline diluted with water ing every bit of th design. Allowy stand until the af hesive is “ tacky” sticky. Place { transfer on the face to be decoratal and rub down hay with a cloth « preferably, with rubber roller su as is used for mou ing photograp Work from the ce ter outwar to avoid wrinkli Next saturatet paper backing wi lukewarm wate Wait about thi minutes before ¢ ing this, however, if glue has been used an adhesive. If any air bubbles are sea after applying the water, smooth the) with the roller. Then lift or slide off tk, paper backing. Clean the surface immediately sponging with water. In case the tran has beeri applied with varnish, the wa will not remove surplus deposits of nish, so go over the entire surface a secotl time with gasoline diluted about 5014 cent with water. No hesitation need lt felt in doing this if the surface, wh paint, enamel, lacquer or varnish, is t oughly dry, as it will not appreciall affect its appearance. Even should t& finish become streaked for any reason¢ ing the application of the transfers, ite be polished with furniture polish or to restore the luster. It is important to wash up the suri at once after removing the paper backilf because the gum remaining on the face the transfer is otherwise almost certail pucker and crack the design. Even the best transfers sometimes sé a bit temperamental and occasionally @ may go wrong, but if reasonable car used, there will rarely be any difficulty. If one has had any experience in work or decorative painting, it is of possible to touch up designs with a oil colors so as to (Continued on page July © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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July, 199 — ers it edge jug the verticy s before rely m ign will ng - crooked, rnish is q) ers, as it kering. Th re. cement are u iquid gluey rs because ‘e propertig ut there 5 fers to dray the adhesin nsfer, cove. ry bit of th 1. Allow d for moun photog p rom the ce outwar d wrin cli saturatet acking wi rm wate bout thir ; before ¢ been usedai bles are sea mooth then! slide off tk ediately iy . the tran h, the w osits of face a secon bout 501 tion need i ace, whi nish, is th appreciall 1 should th y reason nsfers, iteal olish or » the surlat aper backilt n the face »st certail netimes se asionally om nable care - difficulty. rience in# , it is ole with artis d on page ge 6. July, 1927 —— How to Apply Transfers (Continued from page 88) pring out the high lights and shadows and tone down or change the colors, where necessary, to bring the design more in harmony with the body color. If well done, this makes the design appear wholly hand painted. It is frequently resorted to by professional furniture decorators. Whether a protective coat of varnish should be applied over the transfers de- nds upon the individual piece, how it will be used, and the effect desired. If it is going to have any hard _wear over the decorated surface, as, for instance, in the case of .a breakfast table or the back of a chair, the transfer must be protected; otherwise the hand-painted effect will be most fully preserved by leaving the trans- fer uncoatéd. ARNISH, when used as a protective coating, is generally applied with a small brush, following the outline as closely aspossible. This gives a glossy luster to the design and changes the effect consider- ably. Clear brushing lacquer may be used and, as it has not so high a gloss, gives a more artistic effect than varnish; indeed, it is an ideal coating for this purpose. Clear lacquer does not, as one might ex- pect without trying it, “pick up” the transfer colors or cause them to “bleed.” Flat varnish also may be used; it dries without gloss, but has little wearing qualities. Sometimes a pleasing effect is ob- tained by coating the entire surface of uered articles with clear lacquer. One should make sure of the effect in advance, however, by trying a small sample, as this treatment will change considerably the appearance of a colored lacquer finish. If the piece had been finished with enam- el instead of colored lacquer, do not con- clude that varnish can be similarly used over the entire surface, because it gives a distinctly yellow tone, especially over light and delicate tints. After making a few experiments with decalcomania transfers, you will find you have at your command one of the most inexpensive and attractive methods of decoration ever developed for furniture and craft work. Painted Glass Checkerboard MAKE a glass checkerboard, cut a piece of plate glass 14 or 15 in. square, grind the edges smooth with emery powder moistened with turpentine, mark off a border of 1 or 1% in., as the case may be, and divide into 1%-in. squares. Paint the squares alternately black and red, and the border any color desired. Then mount the glass, painted oa down, in a small table or any suitable rame. AMATEUR woodworkers sometimes have to glue up furniture that is too large for such cabinetmaker’s clamps as may be available. If two pairs of iron bar clamps of either the 3 or 4 ft. length are at hand, itis a simple matter to drill 3¢-in. holes through them at intervals and bolt them together in pairs to make double size clamps. es POPULAR SCIENCE MONTHLY points of the Clemson Star 1. CLEMSON EXPERIENCE . 124 years of the combined experience of the Clemson Family. 2. CLEMSON STEEL... Special Tungsten Steel made to exact specifications and correct manufacturing processes. 3. CLEMSON TEETH .... The correct angle and rounded gullet of the teeth give them the maximum cutting ability, strength and endurance. 4. CLEMSON SET .... The teeth are set in a manner to maintain the proper clearance, to keep the cut free of chips. 5. CLEMSON TEMPER.... The heat-treating methods used give STAR Blades an extraordi- nary degree of strength, tough- ness and uniformity. Every STAR Blade is branded withaSTAR A Star Hack Saw Blade and this Chart free if asked for on a business letterhead This chart in full size in two colors shows the proper hack saw blade to be used in cutting operations. hinery steel, sugian sad Vas cans. An general work. for cutting extra fine stock, thin pipe, a. tubing and sheets. o- Fe HE bint salesman for Star Blades are the Blades themselves. Recognizing this we will send free a Star Blade and above chart, full size, in two colors to any reader of Popular Science Monthly asking for them on their business letterhead. We make this liberal offer as we know that if you once use Star Blades in your plant you will be a regular buyer. Since 1883—for 45 years—we have con- centrated on the efficient and economical production of hack saw blades on a volume basis. This concentration has resulted in the production of a hack saw blade that elimi- nates the great waste of breakage . . . ablade that will do the toughest work. Star blades have gained their prestige by reliable, de- pendable performance. pOCUARTERS for MACK SAW B | CLEMSON BROTHERS,inc. > © MIDOLETOWN, NEW YORK © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. blade for cutting ma- eighteen-tooth hand blade, a good all-round saw for

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Try Shooting asa Relaxation Th e CROSMAN 22 “Power Without Powder’’ Enjoy the pleasnres of target shooting on your picnics, camping or out- ing trips. . Have a shoo ing gallery in your yai oy ment, cellar. Feel the thrill of the bull’s eye —ping! ping! ping!— three, four, five per- fect shots. The Cros- man . je can fired anywhere— needs no cleaning— accuracy unsur- passed—makes no noise—andthe am- munition costs so little the saving soon pays for Even seasoned sharp-shooters find this new gun accurate beyond anything in their experience. Ab- sence of powder-de- it in barrel keeps it true, from first shot to last—like shooting a newly-cleaned gun every shot. Put bullet after bullet through same hole. Establish new high records and astonish your friends. the gun. Here's the most remarkable gun that has ap- peared for years—a . rifle that uses “— Needs no | powder accuracy caning not obtain Powderless, smokeless, noiseless. Never needs cleaning—every bullet passing through barrel acts like swab — leaves it brighter and cleaner. Shoot all day, then put gun away and rest while your friends mess with oily, blackened rags. Next day out-shoot them again with your won- derful Crosman. cleaning, is silent and sci- powerful gun. Complete illustrated. Shows new-shaped bullet—— explains superior accuracy —tells why saving in am- munition soon pays for gun —quotes Crosman feats that delighted owners— pictures penetration tests— reveals novel features— lists exclusive Crosman ad- vantages, etc. Postal! brings it. Write now. CROSMAN ARMS CO. 412 St. Paul St. ROCHESTER, N. Y. POPULAR SCIENCE MONTHLY July, 1927 Send for Free The delight of Booklet menwhowiory Now gk, ship of a handsome, A Square Peg in a Round Hole By Arruur L. Situ AN you whittle a single block which will exactly fill each of three holes cut in a strip of wood as shown at the right? The plug must fit in such a way that it can be pushed right through any one of the holes. The openings are cut in a flat strip of cigar-box wood or thin 3-ply stock 2 by 5 PERSPECTIVE VIEWS OF CUT-OUT PU EACH PUZZLE TO BE FITTED WITH A THAT WILL FILL THE THREE HOLES. ZZLES. PLUG SEE = A single block or plug can be whittled that will fit ac- curately all of these holes => (A PERSPECTIVE OF PLUGS SPONDING CUT-OUT PUZZLES. Two puzzles of the plug-and-hole type. After studying these solutions, it should not be difficult to solve the problem above i in. The triangle has g —a— base and altitude of 1 in, the square is 1 in., and the T measures 1 in. each way, The plug which will §jlj these holes will be illus. trated in the August issue, This puzzle is similar to the very old one of the circle, square and cross, which is also illustrated. The problem, indeed, can be varied infinitely. Letters may even be used as in the PSM (Poputar Scrence MontTHuiy) puzzle shown, In this example the let- ters are 14% in. high, Most three-letter initials could be treated similarly, The solution of these puzzles depends upon the fact that a solid has three dimensions: in one it may take the form of a circle, in another it may be a square, and in another, a Greek cross or other figure. How to Solve the Poputar Science Block Puzzle N VIEW of the unusual popularity which movable block puzzles are en- joying, a problem was offered our readers last month to move the blocks illustrated below from the position of a Greek cross PS. POSITION GREEK CROSS POSITION First and last positions of the pieces with letters and numbers to aid in fol- lowing the moves required for a solution to a position resembling the letters PS (PorpuLaR SCIENCE). . For the purpose of demonstrating the solution, the blocks are lettered A to I. The box is numbered as if divided into 16 squares. Where two or more blocks are represented in the following tabulation by several letters together, all the blocks so represented are moved at once. The moves are: CF to 8, 12,16 Fto 4,8 A to 14 AB to 3, 4 DEto 10,11, 12 F to 11, 15 D tol, 2,5 14, 15,16 CG to 12, 16 E to 6, 9, 10 HA to 9,13 DE to 2, 3,4 Ito 7 IB to 1,5 6, 7, 8 Htoli5and1l Cto6and2 IBtol,5 G to 15 D to 6,7,10 HA to 9,13 E to 11, 14, 15 F to 10, 14 F to 12, 16 G to 15 DE to 5, 6, 9, 10, 13, 14 AB to 1, 2 Gto4and8 Cto 16 GHI to 3, 7, 11 C to 4 E to 8, 11, 12 Ito4 DE to 2,3,6, D to 3, 4,7 GH to 3, 7 7,10, 11 IB to 2, 6 E to 11, 14,15 Atol5 HiA to 1, 5 D to 9,10,13 HtolSand 14 F to 9, 13 AB to 5, 6 IB to 9, 13 C to l4and0 HI to 1, 2 D to 1, 2, 5 C to 14 G to 3 E to 3, 6, 7 E to 12, 15, Cto7 H to 10 16 The blocks will now be in the PS posi- tion. When this solution has been mas tered, try working the puzzle backward, without referring to the moves above, from the PS to the Greek cross position. Ingenious Block Puzzles You Can Make Easily (THOSE who enjoy making and solving puzzles will find a num- ber of the most fascinating problems with their solutions on our Blue- print No. 65 (see page 91). Included on the one sheet are a number of puzzles of the Chinese cross variety, a movable letter puzzle, the puzzles shown above, and one or two others. Tool Rack of Pipe Straps ALVANIZED OVERLAPPING pipe straps at- a tached to a horizon- tal strip and nailed to uprights at the rear of the home mechanic’s bench in the manner shown make an excellent rack for small tools. Jul ry. These straps are cheap and are made in several sizes. Pipe straps make neat tool holders © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. NR Sl : NOWIHOAA eA MAAR HAS Ae ee tT... SSSSRSSSSS SESS asesessy POOVINIOOMMAMY Ps wo

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duly, 1927 ——— dle has a of 1 in., and the *h way. will fill e illus- st issue, similar > of the is also can be Letters s in the \CIENCE shown. the let- . high. initials milarly. f these pon the as three > it may a circle, » 9, 13 14and 10 » 14 » 12, 15, 5 PS posi- een mas- ackward, s above, position. traps LAPPING ps make holders July, 1927 POPULAR SCIENCE MONTHLY 91 Blueprints for Your Home Workshop AN ONE of the blueprints listed below can be obtained for 25 cents. The blue- prints are complete in themselves, but if you wish the cor- responding back jssue of the maga- zine, in which the. project was described in detail, it can be had for 25 cents addi- tional so long as copies are available. The Editor will be glad to answer any specific questions relative to tools, ma- terial, or equipment. PopuLAR SciENCE Montuiy 250 Fourth Avenue, New York GENTLEMEN: 2 Send me the blueprint, or blueprints, Ihave underlined below, for which I in- ee dollars........ cents: Described No. Title inIssuesof Price 1. Sewing Table Feb., 22 25c 2. Smoking Cabinet Mar., ’22 25c 3. End Table Apr., “33 25c 5. Kitchen Cabinet May, 22 25c 8. Shaving Cabinet June, 22 25c 9, Arbor, Gate and Seats July, "22 25c 10. Porch Swing Aug., "22 25c 11. Bench and Tilt Table Sept., ’22 25c 12. Electric Washer Oct., “ae 25c 13. Tea Wagon Nov., ’22 25c 14. Christmas Toys Dec., "22 25c 15. Workshop Bench Jen., "75 25c 16. Inlaid Radio Cabinet Feb., 23 25c 17. Cedar Chest Mar., ’23 25c 18. Phone Table and Stool Mar., ’23 25c 19. Grandfather’s Clock Apr., °23 25c 20. Flat Top Desk Apr., “25 25c 21. Colonial Desk Apr., “23 25c 22. Cabinet and Desk Apr., "23 25c 23. Pergola Garage May, ’23 25c 24. Gateleg Table June, ’23 25¢ 25. Canoe Sailing Outfit July, 23 25c 26. Baby’s Crib and Pen Sept., ’23 25c 27. Kitchen-Cabinet Table Oct., °23 25c 28. Pullman Play Table Nov., ’23 25c¢ 29. Toy Tea Cart, etc. Dec., "23 25c 30. Tool Cabinet, etc. Jan., "24 25c 31. Sewing Cabinets Feb., "24 25c 32. Chinese Game Table Mar., ’24 25c 33. Dining Alcove Apr., "24 25c 34. Garden Trellises May, "24 25c 35. Simple Radio Cabinet Oct., "24 25c 36. Rush-Bottom Chair Nov., ’24 25c 37. Simplified Bookcase Dec., 24 25¢ 38. Sheraton Table Jan., "25 25c 39. Salem Chest Feb., "25 25c 40. Desk in Sheraton Style Mar., ’25 25c 41. One-Tube Radio Set May, ’25 25c 42, Three-Stage Amplifier June, ’25 25c 43. Four-Tube Receiver July, "25 25c 44. Pirate Ship Model—Hull Feb., °26 25c 45. Pirate Ship—Details 46. Galleon Model—Hull May, ’°26 25c 47. Galleon Model—Details June, 26 25c¢ 48. Sailing Yacht Model july, °26 25c 49. Broom Cabinet Aug., 726 25c 50. Airplane Model (Flying) 51. Clipper Ship Model—Hull Oct., 26 25c 52. Clipper Model— Details Oct., "26 25c 53. Clipper Model—Rigging Nov., ’26 25c 54. Five-Tube Radio Set Oct., 26 25¢ 55. Five-Tube Set—Details Oct., "26 25c 56. Bird and Animal Toys Zep 26 25c 57. Constit ut ion Model—Hull Jan., °27 25c 58. Constit ution—Rigging Feb., -°27 25c¢ 59. Const it ution—Rigging Mar., ’27 25c 60. Welsh Dresser 61. Viking Ship Mode'—Hull Apr., ’27 25c 62. Viking Ship—Details io. “W 25c 63. Toy Motor Boat—Hull May, °27 25c 64. Toy Motor Boat—Details May, ’27 25c 65. Six Simple Block Puzzles June, ’27 25c eee eee ee eee eee ee eee eee ee eee ee eee eee) NS PORE er err eee slits lin, Making measurements accurate to thousandths of an inch is everyday work for Brown & Sharpe tools in the hands of mechanics. In fitting small parts in automobiles, sewing machines, motors and in the manufacture of thousands of other products where accuracy is vital, Brown & Sharpe tools play an essential part. Wherever mechanics must rely on accurate tools, they use Brown & Sharpe products with confi- dence that the work will be right. For the per- formance of Brown & Sharpe tools sets a stand- ard of accuracy throughout the mechanical world. BROWN & SHARPE MEG. CO. PROVIDENCE, R. L., U.S.A. eae f Hardware dealers can supply you, or write for Catalog No. 30. © “World’s Standard of Accuracy” © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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ae a cae ES Ce ee POPULAR SCIENCE MONTHLY July, 1977 Keeps Your Eye on the Ball Your next “play” in develop- ing a machine aims at the goal of higher production—and you'd like to see how it scores. Your every move will register on a Counter; each change in mechanism or operating method. Just keep your eye on the dial! You can gauge your gains in machine production and follow through ta new records on your REAR The Set-Back Rotary Ratchet Counter below is for machines such as presses and metal-stamping machines where a reciprocating movement indicates an operation. Registers one for each throw of the lever and sets back to zero from any figure by turning knob once round. Supplied with from four to ten figure-wheels, as required. Price with four figures, as illustrated, $11.50 subject to discount. (Cut less than \% size.) Set back Revolution Counter of similar model, $10.00 (list). Smaller counters from $2.00 up. The “Form UM” Magnetic Counter below counts operations or units of output, from any distance that wires connect with machines. Can be placed over desk or on convenient Counter-Board. Cut 4% Size. Mechanical contacts on your ma- chine make and break the electrical cir- cuit which operates the counter. The electro-magnetic drive can get its current from your regular lighting circuit (110 volts), or from storage battery. Write us about that counting problem of yours—at least ask for counter catalogue. The Veeder Mfg. Co. 44 Sargeant St., Hartford, Conn. A Driveway for Your Garage | (Continued from page 75) mix will fill 38 lineal ft. of runway 18 in. wide and 6 in. deep. Have it dumped in several shallow boxes on the ground be- tween the runways. Order only a cubic yard at a time, as it takes three or four hours to lay and finish. The next easiest way, if the runways are, say, 50 ft. or more in length, is to rent the smallest machine mixer available, of about 4-yd. capacity. This is espe- cially desirable if the garage floor or other concrete work is to be done. Have all forms and equipment ready; then one or two days’ use of the mixer will probably complete the work at low cost. Instruc- tions for starting and operating the mixer can be obtained from the renting company. The machines are simple and easily operated. F YOU decide to mix by hand, first construct close to the forms a platform about 8 ft. square, of shiplap or tongue- and-groove boards laid on two by fours spaced about 2 ft. apart. Build in one piece so that the platform can be picked up and moved as the runways are filled with successive batches. Use a square-pointed shovel, designed for this work. A long handle is usually preferred because it saves some stooping. A garden spade is handy for working the concrete against the forms. When one person is working unaided, a “batch” based as previously explained on one bag of cement will be found about the right size. Dump 2 cu. ft. of sand on the mixing platform, measuring it and the gravel in a bottomless box holding an exact cubic foot, 12 in. on every side. Spread out the sand and distribute the bag of cement over it fairly evenly. Mix thoroughly by turning over until the entire pile has been moved four times or more. Now add water evenly, by using a hose or sprinkling can, and again turn the pile at least four times. Spread the “mortar” out, and add 4 cu. ft. of gravel on top, and again turn, in this instance at least eight times. Add water until the mushy mass when piled settles or flattens out under its own weight, but still does not run all over the board. HOVEL the mix into the forms, taking care to work it down into the corners as you go and force it against the sides of the form. Heap it about )% in. above the top edge of the form, and shovel the entire batch into the form before smooth- ing the surface. Now take a wood “float,’’ which is simply a piece of wood 4 in. wide and about 14 in. long, with corners rounded and a handle in the middle, and carefully trowel the surface until it is smooth and just even with the top edges of the form. All gravel should be worked beneath the surface. If a rounded corner is desired, use an “edging” tool, and for spacing into sec- tions, as is usual on sidewalks, a groover is necessary. I have a very fair runway, however, without either of these special tools. Leave the end of this section sloping, and immediately mix and place another batch. When you cease work at the end of the day, place a short board at the end of the work. When starting another section the next day, remove the board and place a strip of expahsion material (asphalted felt). A still better way is to place the expansion strip‘first, tacked ty the board, and then remove only the board when the next section is poured, Freshly laid concrete should be covered, Leave it for a few hours until the surface is hardened and then lay boards acrogg the forms. After a couple of days, place sand, earth, sawdust, burlap, or similar material on it, and keep this damp for g week by sprinkling. Always protect the concrete from the direct sun. If the work is done in rainy weather, the board cover will be sufficient, but a hard rainstorm within a few hours of laying will cause g pitted surface, even if the water merely drips through the cracks. i POSSIBLE, do not use the runways for three weeks or more. When remoy- ing the forms, be very careful not to chip or break the edges. As a rule it is best to leave the forms for several months, thus preventing too rapid drying of the edges and likewise protecting them from dam- age until they are hard. Smoothing the surface as laid, by means of a wooden float, will give a semi- rough finish which is quite suitable for runways. Use of a metal trowel will givea smoother finish, but it may be slippery. If the grade is steep, or the slope is across the runways, it may be desirable to leave an extra rough surface by laying the wooden trowel on the wet surface just before the “initial set” and slowly raising it again. On very steep runways a series of “cleats” can be made by pressing 4 narrow strip of wood across and into the concrete just before the final set occurs,a| | few hours after it has been poured. Any desired sort of design can be pressed into the surface, by making the “die” beforehand. With a small sted trowel or groover and some green paste, made by mixing mineral coloring matter with cement and water, decorative Ee terns can be laid out. A flagstone effect is obtained by making wide and irre zigzag grooves in the surface and filling them with green mortar to simulate grass. From three to ten pounds of coloring matter per bag of cement is usually used. It is also possible to color concrete by mixing in green or other mineral powder from the paint store. In order to save expense and avoid any possible weakening of the main body of concrete, it is advis able to mix thoroughly a mortar of ce ment and powder, adding gravel, finally water. Use this as a top surface about % in. thick, applying it within about an hour—before the underbody has become hard. Granite effects can be obtained inet pensively by mixing into the mortar granite and fancy crushed quartz chips or marble dust. The top surface can be wire-brushed so as to bring out the attractive quartz surface. ee r1S} This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. ee Jul

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July, 197 aad %¢ another the end 1 at the another 1e board material Vay is to acked to | | only the} | | poured, | | covered, | | e surface | | 1s acrogs | | ys, place r similar mp fora otect the the work ard cover ‘ainstorm | 1 cause a | or merely | runways | nl remoy- | yt to chip | is best to iths, thus the edges om dam- laid, by ve @ semi- itable for will givea slippery. e is across e to leave vying the ‘face just ‘ly raising ‘S @ series pressing & 1 into the L occurs, a} | ured, 1 can bel! aking the mall sted en paste, ng matter ative one hed 1 irregular und filling late grass. f coloring ally used. yncrete by al powder ‘r to save veakening t is advis tar of ce ravel, and! yp surface it within inderbody ined inek ie mortat urtz chips, ice can be! - out —$— July, 1927 Roman Candle Propels Fireworks Barge This toy boat, alight with fireworks, is a novelty for any Fourth of July celebration ITH a few Roman candles, spar- klers, flower pots, and the like, any boy can have a “whiz of a display”’ with a fireworks barge made as illustrated. Cut a piece of board boat shaped, mount a cigar box on it, and set up two masts with the lids of baking powder tins nailed on their upper ends. Fix a holder fora Roman candle at the stern. With an awl or wire nail, make holes around the edges to receive sparklers. Set the fireworks in place, clamp the Roman candle down firmly in its cradle with a block of wood, launch the boat and light everything, the Roman candle last of all, as its explosions will propel the boat through the water. If the pool is small, fit a rudder to steer the illuminated ship in a circle.—Hr S1Biey. High Power Fruit Press Made with Auto Jack and Rim N THE illustration below is shown how I combined an auto jack and an old clincher rim to build a high pressure fruit press on my home workbench. A hole was bored through a piece of 2-in. plank to receive a bolt, which was passed through the tire valve hole in the rim and through a hole in the bench. A nut drew the whole structure firmly in place. A flat bot- tomed pan was placed on the plank, and inside of it, a vessel of smaller diameter with holes punched | in its sides near the base to allow the A powerful press for juice to flow out extracting fruit juices freely into the larger pan. Acircular block of wood was fitted snug- ly into the inner vessel; on it was placed another block, on which in turn was set the foot of the jack. With the jack bearing against the top of the rim, the apparatus was complete and ready for operation. If small quantities of fruit are to be | Prepared, it is sufficient to press the juice out into the lower pan, which is emptied when full. On a larger scale, it is better to punch a hole in the bottom of the outer pan so that the juice can be caught in another vessel. This, of course, ruins the pan for other purposes. —OweEn Lovevoy. POPULAR SCIENCE MONTHLY 93 TELEVISION-— With television now an accomplished fact, it may not be long before we are all taking our ease in front of a new type of radio, watching pictures spring out of the air. Meanwhile, keep the electrical contacts of your present radio clean with a NICHOLSON Tungsten Point File. Or, if you want to sharpen edged tools, use a NICHOLSON Mill Bastard File— or, again, if you need a tool to cut away metal stock, use the NICHOLSON Flat Bastard File. There are NICHOLSON Files to meet every filing need today—and there will be in the future. You will be interested in our booklet “Adventures and Uses of NICHOLSON Files.” Sent compliment- ary, of course. OLS, NICHOLSON FILE CO. *Se% ® PROVIDENCE, R.|., U.S.A. U.S.A. BTRADE MARKY —A File for Every Purpose auistuteeteeneneaiiemenenene eeeemnemeneenliemmmmamemnia — © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. — a ——= Se ee Se

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fib hor meanness Ferd ao 94 IF YOU CAN USE AN EXTRA #20°° BILL OU can save $20.00 in no time by using SMOOTH-ON NO. 1 to do your own household repairing—and in addition you will have that proud ‘“‘I-did-it- myself” feeling. Here is what one enthusiast did with two 35 cent cans:—A $25 lamp stand loose in base, two big leaks in heating furnace smoke pipe, loose hammer handle, and three loose hooks in tiled bath room wall were all put into good usable condition at an average cost of 10 cts. for each repair—and $20.00 easily saved over what would have been paid to professional fixers or for new parts. By using Smooth-On to make dozens of the simple repairs necessary in every home, you can save enough to pay your radio upkeep, buy yourself or your wife a camera, a bull pup or some other pleasure giving article that you would otherwise hate to spend the money for. On the Automobile Smooth-On No. 1, being unaffected by water, oil, gasoline or heat, is also excellent for automobile repairs. Try it for stopping radi- ator, tank, pipe line and hose connection leaks from the outside, keeping exhaust line connections tight to prevent the escape of obnoxious burnt gases, repairing cracked water jackets and crank, gear and differential cases, keeping grease cups, lubricator connections, | nuts and hub caps from loosening and falling off, tightening loose hinges, robe rails, etc. The FREE Smooth-On Repair Book ~— will show you how an astonishing number of home and automobile repairs are as easy for you to make as for somebody else. e . Mail the coupon for a free copy and get Smooth-On No. 1 in 7-02. or 1 or 5-lb. can from any hardware store. —_ Smooth-On Mfg. Co. Dept. 58, 574 Communipaw Ave. JERSEY CITY, N. J. SMOOTH-ON MFG. CO., Dept. 58, 574 Communipaw Ave., Jersey City, N. J. Please send the free Smooth-On Repair Book. Return this coupon for a FREE copy of Booklet © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. J POPULAR SCIENCE MONTHLY July, 1977 ————___ There Is Still Time for Y ou to Build Our Viking Ship Model By Capt. E. Armitage McCann The completed model is a picturesque and colorful decoration, yet easy to make with the aid of our Blueprints Nos. 61 and 62. VEN if you are not one of those who have been building our Viking ship model from the instructions given in the April, May and June issues, you can begin now simply by sending for PopuLarR Science Monrtuty Blueprints Nos. 61 and 62 (see page 91). These show all the parts full size and are undoubtedly the simplest of all our ship model blue- prints to follow. Those who wish may improve the ap- pearance of the hull by doing some addi- tional carving. Down the stem and stern on both sides of the centerpiece, from the head and tail, cut a pattern such as is indicated on Blueprint No. 62—scrolls or concentric circles. On the ends of the gunwales there should be similar scrollwork patterns. Along the rest of the gunwales, I suggest cutting or burning a rune. One is given full size on Blueprint No. 61. On the steering gear, when it is made, you may burn the name of the Norse God “Thor” | and on the oar blades, if oars are made, gir, the sea-god. Next come the shields, of which there should be seventeen on a side. Button molds may be used, but they are clumsy. White and black checker men sawn in half would make See list on page 91 their diameter shave them down to rather less than half their thickness. Make thin brass wire staples 14 in. each way, and drive these into the backs. Cut the points off 16 square and 18 conical-headed antique upholstery nails, leaving just enough shank to go through the shields. Cut a slot in a piece of wood to take the staples so that the shields will lie flat, and drive the fancy nails in, after drilling holes. For further ornamentation, gesso is best, but any embossing paint will do, or the designs may be carved. On the shields with the conical nailheads, run five lines from the center to the edge, Around the edge of the other shields, place a series of dots. The backs may be var. nished; the faces of the eighteen painted black with gold lines, and of the sixteen, yellow with black dots. To put these in position, bore holes down through the gunwale and molding, each hole being in a middle position be tween the oar holes. Into each of these carefully drive with a touch of glue half of a round toothpick. When all are in, snip them off so that they project about 3¢ in. and give them a coat of light stain. The shields are dropped on these by theit arm-holds (sta ples), but it is bet good shields, but I found it just as easy to cut them from semihard- wood. Plane down to Y in. a number of strips that are more than 1 in. wide, and lightly nail four or five to- gether. Draw 1-in. circles on these ay - egis eas ter to leave them off for the present. The steering oat is made of any ones 3 te whic shou turn eithe ends of th end | ing. crote to sj cente ¥ in. it in rest 0 them ¥ in. Th stripe yelloy shoul wood 31% in. long by % in. at the widest. When the bottom of the oat is level with the keel, bore a hole to take a pin driv- en into the hole ia and fret-saw them. For about half The shields are cut from thin wood and decorated with upholstery nails and paint the lower cleat, (Continued on page 9)

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July, 1927 . to rather Make thin way, and ‘e and 18 ery nails, o through ‘e of wood hields will ls in, after gesso is t will do, . On the eads, run the edge, elds, place ay be var ‘n painted 1e sixteen, yore holes 1 molding, »sition be- h of these t glue half all are in, ject about ight stain. se by theit Ids (sta- it it is bet save them 1e present. Leering oat e of any 14 in. long in. at When the of the oat with the re a h a, pin driv- the hole ia ver cleat, -d on page 9) —_—_$_ Joly, 1927 — Our Viking Ship Model (Continued from page 94) BSRIR CENTER OAR. OTHERS SHORTER K The sail, tent, pennant, steering oar, anchor, jramework for tent, and center rowing oar which was described last month. This should be an easy fit so that the oar will turn on it. Bore holes in the top cleat on either side of the oar and through them pass a cord to hold the oar, knotting the ends inboard. To a hole in the lower part of the blade, tie a cord; fasten the other end loosely to a hole in the backboard. Poles will be needed for the tent awn- ing. This may extend from the forward crotch to the after one, but it looks better to spread only the after end from the center crotch to the third one. One pole will lie in the crotches, extending about % in. beyond them. With thin cord lash it in position. Make four shorter poles to rest on the top of the hull proper and cross each other over the ridge pole, and lash them in position. All the poles are about ¥ in. in diameter. The tent itself may be linen or silk, striped yellow and red, red and white, or yellow and black. Tie the corners to the poles, or, more correctly, to holes in the gunwales. The mast, which was previously made, should have a hole drilled 14% in. irom thé top for the halyard. The yard will be 834 in. long and 3% in. in diameter at the idle, tapering to about one third less at the end. Both spars should be stained brown. The real sails were made of dyed wool, but this is rather heavy for a model, so silk or linen may be used. The example shown was made from a piece of silk shirting, with red, yellow and white stripes, so cut that the stripes are even on both sides. A plain silk or linen can be used and the stripes painted on it. The chief thing to remember is that we are building a ship (Continued on page 96) re POPULAR SCIENCE MONTHLY Audiometer Audiphone VITA PHONE By-products of your telephone Ts microphone, familiar to the radio world, has been called “younger brother of the telephone.” It is but one of a family of products which owe their existence to the com- munication system engineers and to the men who made your telephone at Western Electric. Forty-five years’ experience as man- ufacturers for the Bell System has brought not only a telephone that is the world’s standard, but also a Vitaphone to give a voice to the motion picture screen; an Audiometer to test the hearing with accuracy never before possible; an Audiphone which gives new aid to the hard of hearing; an Electrical Stethoscope to amplify the faintest heart sounds; a Public Address System to carry a speaker’s voice to crowds of thou- sands and tens of thousands. Making telephones that are the world’s standard, Western Electric has now broadened its field of activity to include the manufacture of many other types of equipment to com- municate sound, and in so doing has immeasurably broadened its oppor- tunity to serve. Vitaphone 1 ¥ iy ga@a bhi BU Electrical Stethoscope sack of your telephone esfern Electric Since 1882 Manufacturers for the Bell System © This seal on a radio, tool or oil burner advertisement signifies tne appreval of the INSTITUTE OF STANDARDS. See page 6.

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Harmonica Band! > you can learn to play as well as the next fellow. All you need is a Hohner Harmonica, our free instruc- tion book, and a little practice — and first thing you know, you'll be reeling off the tunes like a veteran! ~ Pretty soon you'll be locking round for some other chaps to join you in a harmonica band—and that’s when you'll really appre- ciate what fun there is in being able to play this “miniature orchestra.” There are harmonica contests, too, in which thousands of boys take part—and some mighty handsome prizes waiting for those who win! A special orthophonic Victor’ Record (No. 20377) “How to Play the Harmonica” is now available for those who wish to learn by listening to the living voice of the instructor, and following the notes as they are sounded on his harmonica. Illustrated instruction sheet also included. Reverse side réproduces**Old Black Joe” as rendered on harmonica with piano accompaniment. At all dealers selling Victor Records . . . complete 75c \ FREE Instruction Book Anyone can learn to play the harmonica b lowing the clear, simple, illustrated

instructions given in our booklet “‘How to Play the Harmonica.” Free at your dealer’s—or write to M. HOHNER, Inc. Dept. 504 114 East 16th Street New York

POPULAR SCIENCE MONTHLY July, we | suty 3} Our Viking Ship Model | (Continued from page 95) ay with a gold and black color scheme, helped prevent the shields from falling of out with a touch of red here and there. hitch a thin cord to the tholes. ’ On the center is painted a prancing There is no direct evidence as to the| black horse, having its mane tied with exact shape of the anchors carried hy! ribbons and a heraldic tail. The Norse- these vessels, because the iron part Me men seemed to have been particularly rusted away, but from the wooden stock | fond of horses by way of decoration. remaining, it would presumably be the! The sail may have some thin shellac shape illustrated on page 95. It may be A painted on where it is to be cut, to pre-cast or cut from sheet lead. : | lise vent fraying, or be hemmed, or have The cable is a piece of heavy call | | wit brown cord sewed around the edges. It about 10 in. long or two pieces laid te || ben may be allowed to hang slack, which I gether; this is hitched to the fing} | pail rather prefer, or and twisted round Pp ' may have wire sewn the post on the boy, || | pho _into the hems to the rest being coilei} | clea make them belly down in the bottom | | a 80 out, or may be of the ship. Att painted with thin This vessel hay} | any gum arabic or shel- sixteen pairs of oar, | | bein lac and bellied out These may be mak A with an electric fan and laid inside, @ | | the while drying. The shipped by putting | | tone sail is shown hang- the ends through} | acet ing slack on page the oar holes. The} | suffi 94 and bellied out center ones are 44) | latt on page 70 of the in. long, the others} | thin April issue. You SIDE FRAMES OF gradually shorte,. | | tion may take your BASE 4, THICK ing to about 3% in } | Plac choice. : long for the en} | pow The top edge is ones. The flat blada | | and sewed to the yard are a full \% in} | This with a buttonhole wide by 1% in. log firml st itch (marline- How the shields are made and decorated, and a and the looms a full meta hitch). The lower stand designed to carry out the dragon motif yy in. in diameter, sitiol corners have light When shipped they If cords sewn to them for sheets. To the are rather a nuisance and I think th) | luloi center of the yard fasten a cord with a __ ship looks as well without them. beus round turn and hitch, leaving a long end There remains but a base, or stand, wf | the c which is hitched round the mast; theother make. This may be any pattern yo§ | tate. end goes through the hole in the mast, please. from and is made fast to one of the beams. That is all! I am sure that those wh) | fect To the yardarms are fastened cords have built the ship will have a very gay} | °S¢ which are hitched to the after beam, and and interesting model in their homes. aceta from near the top of the mast another May one also suggest, for those wh} | ons cord leads to the stem, where it is tied _ like pairs, that it consorts very well with} | ito: under the dragon’s head. From the very _ the pirate galley described some time ag En top of the mast there may be a long _ in this magazine and for which blueprials| | addec pennant flag of red or yellow. (Nos. 44 and 45) are still obtainable. easily The shields may now be placed on their a whick tholes, alternate black and yellow, start- Next month, a ship model weathe and ing aft, so that they overlap slightly, the vane. Quaint decorations of this typ stirres outer edges being, the after ones. To are all the vogue. Say mus ; Av Aerial Top Made with Spools and Clothespin | |*.,3 By F. Crarxe HuGues Z be pas small end of one of these sections is SECTION PROPELLER fitted and glued part of the clothespin, ais ( as shown. Into the large end is glued a = Ss" short dowel. When the glue is dry, — bom round the end of the dowel with sand- The parte weed for making the ewtiill Diseo paper. This completes the handle. and how they are assembled for spinning pl Cut out the sheet metal propeller, twist ? var the ends, and punch two small holes less brads into one end to receive the pm | jany’™ about 1 in. apart, as indicated. Prepare peller. The toy then may be enam Bottle the motor spool by driving twosmallhead- one or more colors. hme - —— — © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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leavy cond | es laid to.|| the ri sted round on the bow, eing Coiled the bottom ip. vessel has airs of oars, ay be made inside, or by putting s t holes. The les are 44 the othey r shorten. out 3% in + the end e flat blades ull \ in 154 in, long ooms a ful those who a very gay SPOOLS ) RD & LLER = aerial top - spinning ve the pit nameled i} — Home Workshop Chemistry Simple Formulas that Will Save Time and Money CETONE is a light, mobile liquid, very volatile and inflammable. | It iscolorless, has a fragrant odor and mixes with water, alcohol and ether, as well as henzol. It can be obtained at the larger int stores and chemical supply houses. Primarily acetone is a solvent for cam- phor and celluloid. It is often used to clean bottles, flasks and cans. since it has a solvent action on many oils and rosins. At the same time, this liquid will remove any water present in such vessels, and, being volatile, it dries them quickly. A bronzing solution may be made with the aid of ace- tone and cellulose acetate. Dissolve sufficient of the latter until a thin,flowing solu- tion is obtained. Place the metal powder in this and stir it well. This will hold firmly on wood, metal or compo- sition. If desired, cel- luloid chips may beused in place of the cellulose ace- tate. Celluloid from old photographic films is just as effective as purchased chips. In this case, however, benzol, acetone and amy] acetate must be mixed in equal propor- tions before the celluloid, which is cut into small pieces, can be dissolved. Enough of the celluloid should be added to the solution to make a thick but easily brushed fluid. The metal powders, which can be obtained in any paint store and many hardware stores, are then stirred into the mixture. Only enough should be mixed for immediate use and it must be applied as quickly as possible. A varnish, which is not especially strong or durable, may be made in an emer- gency. About 1 oz. shellac is dissolved cold in 4% pt. acetone with the aid of vigorous shaking. Pulverized rosin may be taken in place of shellac; it dissolves more rapidly. When a solution has been effected, 14 0z. ozonized turpentine is added. As a reminder, the following label may be pasted on the acetone bottle: Mixing acetone and shellac with stirring device run by motor Acetone (Dimethyl ketone) CH3-CO-CH3; Keep this light, volatile liquid in a tightly corked ttle. Keep away from flames. Dissolves celluloid. By smearing the cork and the neck of any bottle with this mixture, the bottle can be ss oer tightly. _4 varnish can be made quickly in an emergency by devolving shellac or even powdered rosin in this Bottles, flasks and cans may be cleaned with ace- tone as it dissolves fats, rosins and oils. It is often used in paint and varnish removers. POPULAR SCIENCE MONTHLY | | 2 wtf y ~Se ge a rowd this summer with real sport / lw outdoors is waiting for you. Slip away from the stifling heat and everyday scenes. A fishing trip for a day or a week! A jaunt over long stretches of country road! A spin through the fresh night air! Happy hours on the golf course — at the beach — or a couple of weeks of glorious, carefree vacation! Enjoy yourself this summer as you never have be- ~ fore. Know the thrill that comes with the proud ownership of a Harley-Davidson Twin. This trim, good looking mount—sturdily built and dependable under any conditions — costs only 2¢ per mile for gas, oil, tires and all! Plenty of room in the sidecar for a friend and your outfit. Prices as low as $310 f. o. b. factory — on easy Pay-As-You-Ride terms. See your Harley-Davidson dealer — send coupon for catalog. Har.Ley-Davipson Motor Company Department PS Milwaukee, Wisconsin HARLEY-DAVIDSON The Single is the famous Harley-Davidson solomount — 80 miles per gallon. Price, $235 f.o. b. factory. — ““ SR a ND A a ene

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. En eaten z POPULAR SCIENCE MONTHLY essecscsseaeces The New Red Jacket Easy Now master workman. The complete equipment con. sists of the powerful Red Jacket Motor, with direct drive to an accurate w turning lathe (capacity 9 in. x in.); a bench saw, that has depth and side gauges; scroll and jig saw; and all accessories for both por- table and stationary power drilling, buffing. grinding and cleaning. A Special Crafts Course ™ And Blueprint Service is free to Red Jacket Shop owners—all that there is to know about handicraft methods, is taught by special correspondence. Buy on Your Own Terms Only $10.00 down. Interesting Literature Free It’s fun to make furniture, garden trellis, toys, improvements and repairs with a set of tools like this carefully designed by @ Attaches to any light socket and converts your work bench into a complete private tool and machine shop. materials, woods, carving, sawing, turn- ing, designing, carpentering, decorating, Liberal discounts for cash. Easy monthly payment plans. It is no hardship to own a Red Jacket. Just send the coupon. You will be sur- prised with all it contains. Beautiful, § instructive, Fascinating, Interesting. = Everything Explained in Our Literature. Ssenusessssnses MAIL COUPON NOWesssessesssssen WACO TOOL WORKS, 2915 So. Wabash Avenue, Chicago, Illinois. , Manager, Dept. 7. Please send me particulars about 10-day free trial, free blueprints, and $10 down payment. Address PITTI Ifill iiiiii iit, Low Smoking Stand Made Like Bench By Cuartes A. KING THIS popu- = lar type of smoking stand there is ample space for a large assortment of ac- cessories, all of which are hidden when the cover has been closed. The proportions of the piece are such that it may be used in an emer- gency asaseat and it is, therefore, especially serviceable in a small house. Mahogany, oak or any semihardwood may be used. First make the rim of the box, rabbeting each piece to receive the 1 in. thick bottom. Miter the corners and glue on small triangular blocks as shown in the detail! marked “gluing corners” so that hand screws may be applied to draw the joints together. After the joints have been glued, the temporary blocks may be removed and saw cuts made through the corners as shown, so that thin splines may be glued in to reinforce the joints. The grain of the splines should run across the miter. The stand serves as a seat when closed Peel mill: il Hil RTL ill i}! HUMIDOR||_-——— |HUM il tS in i | Makes 5150 w4) Opening Cans a Funny Way Here's an amazing new way to make big money—easy as A-B-C! So surprising that R. A. Stewart Seanad we $151 in aweek! All due to a startling little device that ban- ishes old style can openers to the scrap heap. MEX. this almost magical device is a real ‘million dollar’’ can opener. Imagine a little, inexpensive, auto- matic machine that opens any can, round, square, or oval at the turn of a crank! Cuts the entire top out slick and clean in a couple of seconds. No more snagging your fingers on jagged tin edges! No more fishing around with a spoon to get all the food out of a can! Speedo ends this bother and danger forever. No wonder women sieaply 60 0 coder that agcnts everywhere pad $7 to $izinan hour, steady as clockwork! Agents! Distributors! ory an ner- ous FREE THEE OFFER. ORM today while the it. om “CENTRAL STATES MFG. CO. 4500 Mary Av. Dept. H-840 St. Louis, Mo. ELEVATION (PART IN SECTION) Front and plan views of stand; one way to make corner joints; reinforcing blocks Simpler types of joints may be used, if preferred. Plain butt joints will do if the stand is to be made of a soft wood and enameled or lacquered. Make the legs, shape the rails, and fasten them together with dowels. Then attach the case to the legs with brads or screws driven through the bottom. Make the top, which is 12% in. by 2 ft. 6% in., of &% in. thick plywood, if it can be obtained. Do not overlook the half-round molding, which is_ glued around the case at the bottom. Zinc humidors or other fittings may be arranged and a piece of felt 9144 by 13 in. glued inside the cover as a background for a flexible wire pipe rack. July, in Do you want more sales through hardware stores? W E HAVE distributors located in every important hardware job. bing center in the country now successfully selling our product, This is a “ready-made” up- and-doing sales organization that is now available to manufacturers to sell to the hardware trade foyr | or five additional products that have real merit. ; Also we are in a position to assist manufacturer or patentee finan. cially, if necessary. Please give full details in first letter, which will, of course, be treated confidentially. This advertisement is inserted by an advertiser using Popurag SCIENCE MONTHLY. Address: Box W PopuLar ScieNcE MonruLy 250 Fourth Avenue, New York BUY NOW ‘Sui FREE Save “r: Established 1888 PLUMBING HEATING WATER SYSTEM: jae ’ ‘ { } ; We quote the very lowest prices and give the high- class goods. Full information on all uirements, g oaned. Writs est INSTALL YOUR OWN WORK, Tools | today for money-saving catalog. Wesupply coat at B. KAROL & SONS CO. 200,5-"©°2i FREE TO BOYS Seni “THE SHOOTER’S ART” Tells how to hold, aim and handle rifles; helps Now you guide others in correct knowledge of guns. Gives facts that make crack shots. Contains safety and common sense instruction every ay and boy should have. Helps to make joys leaders. Your copy Free. Write at once. The NEW BENJAMIN 2!8, . P Outshoots ad 4 at your dealer’s r BENJAMIN or sent postpaid. Write! Air Rifle & Mfg. Co., €29 N. Broadway, St. Louis, Mo. This folly guaranteed watch cannot be manofactured in America'lt less than $12. Genuine lezsther strap. Accurate--durable-- SEND NO MONEY. Pay on delivery $3.99 plus postage. **FE U. S. Swiss Agents, 561 Broadway, New York City, Deptiil ee © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. Own a CORONA The portable typewriter built like an office machine, Has four-row keyboard and big-machine features throughout, Write to L C Smith and Corona Typewriters Inc 713 E.Washington St., Syracuse, N.Y- July, to Itd and STA 8) ans

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July, in === nt ough es? located ‘are job. Try now oduct, le” up- ion. that facturers ade four ts that ; to assist e finan. give full 1 will, of tially. inserted POPULAR biiverod, Lee red in Americs'ié July, 1927 dy Toy Glider Folded from Letter Paper ROM a piece of lightweight letter ser 8% by 11 in., you can make a toy glider that will fly surprisingly well. It doesn’t require any measuring or ruling and there is no pasting to be done. At the same time, the little plane is quite FOLD TO RIGHT, OPEN AND (ex FOLD TO LEFT ft ) CUT HERE AND SAVE FOR TAIL B FOLDATOB , , FOLDCTOD A i Oy’ « FOLD THIS WAY REPEAT ON OTHER SIDE aor WILL LOOK LIKE THIS ) Sree FOLD TAIL AND CO =“ CUTON DOTTED Lines eae ea aoe CUT ON DOTTED ie, AND INSERT ENDS E-E INTO G-G Note how points E are tucked in to lock tail and wing Steps in making the glider. sturdy and, barring accident, will survive many flights. The steps in making the glider are | shown in the accompanying illustration, which ‘is self-explanatory. The most satisfactory way of launch- ing the plane is to grasp it with the middle finger over the wing, as suggested in the sketch at the bottom of the illustration. Throw it forward, tail first, with a brisk downward motion. It will turn a loop and then fly gracefully and steadily in a straight line.—H. S. C-Clamp Made from Large Nut ECENTLY I SET SCREW needed a small but very ‘ vm strong C-clamp to . aid in doing a re- pair job. Picking out a 34 in. square nut and a suitable set screw from the junk box, I sawed out one side of the nut as shown and drilled and tapped it to take the set screw. This kink should be useful to model mak- ers, who rarely have a sufficient supply of small clamps.—S. A. AsquiTH. An easy way to make strong little clamps POPULAR SCIENCE MONTHLY To Men _ who think their faces are clean This cream goes into a clean-shaven face pink--and comes out a dingy grey ORE-DIRT is in every face. It greys the cleanest complexion. It defies the daily wash, so that you think your face is clean when it isn’t! Where does it come from? Dusty roads, soot-belching chimneys, passing motors—the air teems with millions of minute particles of grime. These particles are so small you can’t see them. They are smaller than the skin pores; they get packed under the skin. There they hide, laughing at the wash cloth that cleans only skin surface. If pore-dirt is allowed to remain too long, a blackhead results. But generally it merely greys your skin, Highly magnified cross- section of theskin show- ing how pore-dirt be- comes imbedded in the pore. Surface washing cannot remove it. am os" FREE test convinces thousands. The pore after Pom- eian Massage Cream oe cleansed it. The cream first loosens pore- dirt and then rolls the dirt out on the face. gives it a sallow look as though you had been up late the night before. “Unwashable dirt,’ cosmeticians call it. But a minute’s massage with Pompeian Massage Cream rolls every bit of it free. Goes in PINK and rolls out a dingy GREY! Try it!! Prove to yourself that Fompeian Massage Cream beginsto clean where ordinary cleansing stops. First wash your faceand handsascleanasyoucan. Then scoop a little cream from the jar and massage it into your face. Keep on rubbing until the cream rolls out of your skin in tiny pellets. Note this amazing thing — the cream that went into the skin a clean pink rolls out a dingy grey. The gtimed-in dirt is now removed. Your pores can once more fully breathe. Your skin quickly responds to the invigorating massage. Your face looks, feels, and és really clean! Test the benefits of Pompeian Massage Cream on your face — FREE. Fill in the coupon and mail it to us — right now while you are reading this magazine. POMPEIAN MASSAGE CREAM Pompeian Laboratories, Dept.301 G 595 Fifth Avenue, New York City Gentlemen : Please send me a generous trial tube of. Pompeian Massage Cream . . . enough for three facial massages. Name Address___ ae State © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS _ See page 6.

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100 POPULAR SCIENCE MONTHLY July, 197 Always strong at the finish ON THE next to the top step of Bill Gettner’s brand-new hand- made ladder lies the plane he should be using. It’s the Sargent Steel Block Plane—the one for just such small jobs as rounding off the last sharp edges or for use in close quarters. But Bill simply couldn’t resist showing how the big Sargent Auto-Set Bench Plane can be used for even such a close cut as this. It’s a versatile plane—the Auto-Set—great for coarse or fine cutting and so much lighter than ordinary planes of the same size that you can use it for hours without tiring. Both these Sargent Planes should be on every school and home work-bench. They are very moderate in cost and long-lasting. See them at your hardware deal- er’s and write us for descriptive booklet today. SARGENT & COMPANY, Manufacturers, 50 Water St., New Haven, Conn. SARGENT Sargent Steel Block Plane No. 5206 PLANES Sargent Auto-Set Bench Plane No. 714 ¢ weeks of pleasurable practice gives you command of theConn saxo- phone which enables you to entertain yourself and friends. Be popular, increase your income if you wish! Start now with aneasy-playingConn. Choice of world’s foremost artists—and costs no more. Free Trial, Easy Payments onany \ Conn. Write forFree Book, details. ' G. Conn, Lid., 732. Conn Bldg. Elkh art, ind. BAND 4 INSTRUM ENTS © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. Book tellin e for ss ‘ayments. No terest. r made. U all Epa ee rat at Sizes trom 1 1-2 to $0 b. D, Ale in| Saw, igo and Earp Outfits. Write me RE for Free and 2 Seticenrs re Terms Offer. witte Engine w Witte Bidg.,Kansas City, Empire iit: Neat Wooden Stand Holds | Watch at Night M* WATCH rests safely at night ing “watch slot” like that illustrated || The materials needed for making ong like it are a thin strip of quartered oak o other hardwood, 4 in. thick and 2 jy CENTER VELVET OR END PIECE eee Z BASE AND CASING OF |," 0AK How to make a case which protects a watch and allows it to be used as a small clock wide, and a scrap of felt. The parts ap glued together, thoroughly sandpapered, | and stained and varnished. The interior then is lined with fet or velvet, and the bottom of the base js| covered with some material to protect the| table or bureau on which the stand is ty rest.—F. D. How to Grind Smooth Holes through Plate Glass AVING a number of 14-in. holes tp drill in a 4% in. thick sheet of glass I made the tool illustrated. It produce the holes easily without causing amy chipping or breaking. A 4-in. length of stiff brass rod \ in in diameter was flattened slightly at on end and was tinned with solder. A Yin || hole was drilled vertically in a block d wood and the rod was inserted in it sos 14" CARBORUNDUM \S= i> AND Ta SOLDER| “¥ a ) c x * HUCK -s ee. s| en Ne 38GB Se aS % BRASS ROD Method of making a carborundum drill and using it to grind clean-cut holes in glass to allow the flattened end to project ¥ in. above the surface of the wood. A long paper tube was made, havingal internal diameter of 4 in. The inten surface was shellacked to make it pe fectly smooth. This was placed centrall| over the projecting rod and held by meaty of putty. Molten half-and-half solder, which coarse carborundum powder been mixed, was poured into the tuk around the rod. ; To use the drill, a guide block havi a \-in. hole was placed on the glass shet and the tool held in the chuck of ah drill.—W. J. Epmonps, Jr. Juls of blo pla Ex or | onl not whi anc

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July, 197 ——_ | | Holds | it it night ing illustrated, || making one ered oak op project ¥ yood. e, having al The inter ake it per ed centrally) Id by meals} ilf solder, powder hai to the tube lock having e glass shet! k of a hand eT

July, 1927 POPULAR SCIENCE MONTHLY

TheShipshape Home 9» Tue beauty of “Curtains for Garage well-kept yards is i often marred by tempt to keep the windows clean and covered with shades and curtains is an My method of solving the problem is to dampen white scouring powder and apply many otherwise unsightly garage windows. Yet to at- endless task. it to the panes with a small rag or sponge.

The “curtains”? which so greatly improve this garage are made with scouring powder The rubbing can be done either straight up and down or so as to form a sort of floral design. Then the center of the lower panes is wiped out in the shape of an inverted V. The rag and damp powder are next applied along the edges of this V with a circular motion to give the appearance of ruffles on the curtains. My own practice is to use pink colored chalk for the ruffles. —Frances AusTIN TROUTMAN.

THE simple latch Convenient illustrated will Gate Latch keep an ornamen-

tal wire gate closed, yet it requires no time or attention to operate as do many types of latches and hooks. Furthermore, it will last for years and never get out of order. Set a block 2 by 4 by 12 in. on edge and in the center cut a V-shaped notch 114 or 2in. deep and 2 in. long. From each point CK SPRING WIRE

This latch for a light, ornamental iron gate is easy to make and foolproof in operation of the notch, bevel off to the end of the block. Bend a piece of heavy brass wire to the shape of the block and staple it in place so that it will act as a spring. Exactly under where you wish the gate to stop when closed, drive a good cedar or locust stake and spike the block to it. From the fact that the gate is held shut only from the bottom, the catch could not be recommended for use on gates where horses or cattle are kept, but for poultry yards or gardens it is efficient and will save much annoyance and time. —Cuartes E. GarpNeEr.

The Vulcanized Repair The Shaler 5-Minute Vulcan- izer takes the work and muss out of puncture repairing. It is so simpleand safe a child can use it. To make a repair you simply clamp one of the Shaler Patch- &-Heat Units over the puncture, touch a match to the fuel, give it five minutes to cool; then un- screw the clamp and throw the little fuel pan away. That’s all. No gasoline—no sticky cement —no muss. The repaired tube is as good as new and ready for immediate use. When you fix a puncture with the Shaler 5-Minute Vulcanizer the patch is there to stay for the life of the tire. Even under the constant flexing of Balloon tires which loosens ordinary cement- ed patches, Shaler improved Patches are not effected. For this reason alone you should be sure that every puncture is Shaler Vulcanized—to prevent the trouble and tire expense that results from under-inflation due to leaky repairs. But there’s an- other reason.

Be sure you have a Shaler 5-Minute Vulcanizer in your car today. You'll find them in stock wherever auto accessories are carried. If you have a Shaler now, be sure you have a supply of the improved Shaler Patches especially designed for Balloon tires. The SHALER Company World’s Headquarters for Tire Repair Equipment 1007 Fourth Street - Waupun, Wis., Branch Factories: Beeston, Eng., and Montreal, Can. SHA REG. U.S. PAT. OFF.

EASY TO USE Be sure you have this handy outfit in your car today. Fixes punctures in a jiffy any- where—and fixes them right. ee are outfit—$1.50. Extra Patch-@-Heat Units, 75c per box of 12. Prices slightly higher in Canada and far West.

© This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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102 . ‘lore are just two kinds of homes today those that have oil heat —and those that haven’t HERE was a time—not so long ago— when the automobile was the dividing line between those who “belonged” and those who didn’t. Of course, no such distinction will ever be made regarding oil heat— but the fact remains that the most progres- sive people in every walk of life now regard automatic heat as a necessity. Think what it means to turn over all your heating problems toa little ther- mostat that does all the worrying for you, looks after the furnace while you're enjoying those last precious moments of sleep; keeps your house always at the temperature you like best, with never more than 2° varia- tion; does away with the drudgery of the coal shovel, with ashes, soot, dust and dirt; in short, takes every thought of the furnace off your mind and leaves you and all your family free to revel in luxurious comfort all win- ter long. That’s NOKOL automatic oil heat. Here is a burner that revises all previ- ous conceptions of oil heat—a burner that not only eliminates the usual oil- burning noise, heretofore the main objection to oil heat, but attains a new standard of performanceandefficiency. Its amazingly efficient method of com- bustion does away with soot, carbon and dirt, with smell of oil, with waste- ful operation. It gives full auto- matic heat at unusually low cost; a cost about the same as hard coal— often less. Mail the coupon for free booklet on oil heat and details of our convenient budget plan. NEW Silent N No COAL -U.S.PAT. OFF. REG AUTOMATIC OIL HEATING FOR HOMES FREE—NEW BOOK AMERICAN NOKOL COMPANY 4166 Schubert Ave., Chicago Please send me your new book on OIL HEAT. Name POPULAR SCIENCE MONTHLY July, i977 The SHIPSHAPE HOME. You Can Do Better Painting If Y ou Look After Your Brushes Carefully By Ben BriGuTon UCH of your success in keeping your home shipshape depends upon how well you can do paint- ing, varnishing and lacquering. And this in turn depends to a surprising extent upon the brushes you use. It takes a good brush to do a good job, yet many amateurs will use ten-cent brushes in spite of the fact that a pro- fessional painter with years of experience finds it necessary to use the best of tools. Good brushes naturally cost more than poor ones, just as paint of good quality costs more than cheap paint: You may be surprised to find how much good brushes For floors, you will have a choice be. tween a 214-in. round or oval brush org 4-in. flat brush. While some painters pre. fer a flat brush, it is generally considered that the round type produces best results, especially in the hands of an amateur, When doing outside painting, either a flat or a round brush may be used. The advantage of the round brush is that it carries more paint and compels one to brush the paint well into the surface, especially on siding. The sizes most ex. tensively used are 21% in. and 4 in, for The type of perma- nent brush keeper do cost as compared a . used by Raisin with the glorified ie ite Waring, noted au- whisk brooms that S thority on wood ‘ ek a4 nishing, is shown are so often sold at cae a cut-rate paint! coun- ; ters. The cost of a ‘ good brush, however, is only a small per- wire runs through the brush handles and rests in stir- rups soldered in- side the can, as can centage of the cost of See yi be seen in the the materials used in : ad container, ° ° e cans, W painting, and, fur- aan Py 14! 9 in., can be made from a stand- thermore, good brushes will last for A first-class ard sheet of tin, — 20 by 28 in. The brush is always true top of each Aan economy. 2p LP tainer slants slight- As an amateur can- ro { ly by age oa ‘ at: ; ‘ wi piled on i not tell by inspec- ‘te Sine sant tion whether a brush | oe are made of brass is a good one or Be F se not, it is important to buy brushes made by a manufacturer of first-ratereputationor to rely upon the guarantee of a dependable dealer. It makes considerable difference, for instance, whether a brush is made of “flagged” or “butt” bristles; the former is by far the more satisfactory. It is quite as important to select brushes adapted for the work you are doing. Varnishing and enameling require one type of brush, floor work another type. Wall painting calls for regular wall brushes. Outside painting is done with house painting brushes. For varnish, enamel and the new brush- ing lacquers, brushes of the soft bristle type are best. Fitch, bear-hair and ox- hair are all used. Professional auto fin- ishers and some others like camel’s-hair, but it is better for the amateur to use one of the other types. A 2-in. or 3-in. flat brush, preferably the latter, are good sizes for average requirements. You also ought to have a 1-in. or 14-in. brush for small surfaces, as well as a very small brush such as a pencil brush or a 4-in. square-cornered brush of soft bristle. For walls and ceilings a flat wall brush Small brush keepers may be made from care- fully opened vegetable cans. The varnish pan at left was cut from the bottom of a one-gallon can. It has a removable wire rest for the brush round and flat brushes, respectively. A flat or oval sash tool, which is a s long-handled brush, is needed for window sash and small trimming. A duster, pref- erably of the 4-in. flat type, is useful. Bristles are set in rubber, glue o cement. Glue-set brushes never should be put in water. Cement-set brushes are not to be used in shellac or anything contain ing alcohol. Rubber-set brushes can be used in practically any material. Even the best new brushes have a few loose bristles. They can be worked out with the fingers after wetting the brush with oil or tur- (Continued on page 103) — should be used, preferably 4 in. wide. © This seal on a radio, tooi or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. 3 sha the con brol met cork val ers and the tigh plac Yg-il cide heac valy fine the it is tem grou

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July, 1977 ————_ VIE Y ou lly choice be. brush or a Linters pre. considered est results, amateur, g, either q used. The | is that it els one to ie surface, S most ex. 1 4 in. for rom care- rnish pan »ne-gallon the brush tively. A sas or window ster, pref- useful. , glue or should be 1es are not g contail- es can be l. ave a few orked out the brush n page 108) July, 1927 — Look After Your Brushes (Continued from page 102) ntine, or by dipping the brush in oil or int and brushing it on a clean board. The brush can be very well cleaned, too, simply by striking the dry bristles across the extended fingers, as a boy runs a stick along a picket fence. | “The best way to keep your brushes in ood condition is to clean them thorough- ly after each painting operation. Gaso- line is the most economical cleanser, al- though turpentine, benzine and naphtha are all good. | For brushes used in enamel, varnish ‘or paint mixtures, a good cleanser may be made by mixing two parts of gasoline and one part turpentine. | T RUSHES that have been used in shellac must be cleaned with wood or | denatured alcohol, or if hardened, with | varnish remover followed by alcohol. | The cleaning process may be carried fur- ther by washing brushes with warm water and soap, but do not make the mistake of some amateurs who take all the life out of their brushes by using a cheap soap, strong in alkali. Hang the clean brush up by the handle until dry, then wrap it in paper folded flat so as to keep the bristles properly shaped and protect them from dust. Do not store brushe* in a hot, dry place, as the block may shrink or the bristles be- come loose. When brushes are used rarely, that is at intervals of a month or more, it is best to treat bristles with vaseline or paraffine oil, and wash them out with gasoline just before using. This keeps the bristles straight and full of life. Some painters prefer to keep brushes in a receptacle of oil or some preparation such as one part oil and one part turpen- tine, which they term a “brush keeper.” This is an excellent method if one remem- bers to renew the liquid as it evaporates. ‘| Provide a cover for the container. Either drive a tack into each brush handle and suspend it from the edge of the receptacle, or hang it from a wire or stick across the top. If the brushes are allowed to stand on the bottom of the container, the bristles are certain to curl. Tue cork used in P reserving a large bottle in which I keep lin- Large Corks seed oil stuck and broke repeatedly until I devised the method illustrated for preserving large corks. I thread the stem of an old Ford valve, make two large sheet metal wash- ers for the top and bottom of the cork, and tighten them in place with two %-in. nuts, In- cidentally, the head of the |! valve makes a {L- fine stand for the cork when it is laid down temporarily on a bench or table, or on the Large cork reinforced with Ford valve stem ground.—F Rank W. BentLey, Jr. POPULAR SCIENCE MONTHLY 1886 oo J r= 1876 1896 1926 190060 *S° 1916 “— Milestones =! in National Service An Advertisement of the American Telephone and Telegraph Company THERE are twenty-five Bell companies butonly one Bell System—and one Bell aim and ideal, stated by President Walter S. Gifford as: “A telephone service for this nation, so far as humanly possible free from imperfections, errors or delays, and enabling anyone any- where at any time to pick upa telephone and talk to anyone else anywhere else in this country, clearly, quickly and at a reason- able cost.” The year 1926 brought the service of the Bell Telephone System measurably nearer that goal. Seven hundred and eighty- one thousand telephones were added to the System—bringing the total number interconnected in and with the Bell to more than seventeen and a half million. The number of applica- tions waiting for service, including those in new and outlying sections, was reduced fifty per cent. A third transcontinental tele- — line was completed to the acific coast. The largest number of miles of toll wire for one year was added ta: the System—more than 664,000 miles, The average length of time for completing toll calls throughout the System was lowered by thirty- five seconds, A seven per cent improvement over the previous year was made in the quality of voice transmis- sion in toll calls. An adjustment was made in long distance rates amounting to areduction of about $3,000,000 annually. PPLUMBING-HEATING] FURY CLD OT MOT BY Uwe Cla ' ———TT ~“y Lowest wholesale prices on highest quality Grade » A goods, Any Handy Man otateenn can install his own Plumb- y ing and Heating BY OUR NEW EASY METHOD. Get S, the best and pay only a little each month. Send for FREE Book. New bargain catalog just issued. With A material and high labor cost. 50 years i home owners, farmers, ' . E SF BB] of econo, ical service to : ha. f=} ke] builders and mechanics. Million Dollar Plants > ves k a Miback up = Lor mp ggg RG 4 a-° wy ~Y you the whole story. ic your c LJ : = x) Taek e/aN °s6 HARDIN-LAVIN Co. §s: YRS 106-16 West Pershing Road, Chicago, tl. 876 y tae "; e. § our cut-to-fit systems you save waste | The Super Elto clamps on any open boat — gives all motor boating pleasures at amaz- ingly small cost. P s , reliable, Write toda Light and portable. for in- tensely interesting catalog! EL’ OUT- BOARD MOTOR CO. Ole Evinrude, President, Mason St., Dept. W, Milwaukee. SPZLEELO’ IS) This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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104 Conducted by America’s leading magazine for the Outdoorsman Field & Stream Almanac. With covering 15 classes of fish, the 1927 contest will be bi of all. Yet many prizes will be won with fish o' no cmmeontiney size. WINNERS SE- LECT THEIR PRIZES. Get into the contest yourself this year! Complete details in the current issue. Get copy from newsstand Mm or send $1 5 months’ trial Sek subscription to Desk P, 45 W. 45th Street, New York City. SEE @: Grocomn anieenn Sneentiedt an finest motion pictures of hunting and fishing ever made, obtainable on terms amounting to FREE LOAN. Thebest entertainment for ban- quets, emetene or ane ofclubs and associations every kind, or private enter- tainments. Write for Ask the Man Who Mows One The tougher the * beard, the easier : it is to shave with Barbasol. . . No brush.Norub.in. No . after-smart. Try Barbasol— 3 times—accord- ing to directions. “Mister, next!” Barbasol For Modern Shaving ——— a ee ee you’re The Barbasol Company Indianapolis, Ind. I enclose 10c. Please send trial tube. P-S-M-7-27 POPULAR SCIENCE MONTHLY July, 197 i July, Small Shop Method for Tapping Nuts SIMPLE and effective rig for the quantity tapping of nuts is illus- trated. It can be made up readily in the smallest shop from materials that are always at hand. The only economical way of tapping hexagon or square parts is in a second operation, and the use of such a method becomes almost imperative if, as in the present case, the part is rather long, while at the same time a nearly full thread is required. A regular wrench socket of the re- quired shape and form, such as is used in a well-known type of socket wrench, is held between the jaws of a small square vise, which in turn is placed in an ordinary small bread pan and clamped to the table of the drill press. The pan is filled with cutting oil to the required depth. In the drawing the oil level is shown rather low to reveal the arrange- ment, but in practice the oil should nearly cover the product. A regular long nut tap is used and held in the regular chuck of the drill press. The press should be so arranged that when the lever arm is in a vertical posi- tion, pointing down, the tap is at the end of its run. Whenever possible, a spindle depth stop should be used. ———___ CLAMP I>, FINISHED ON SHANK Oris ( é WRENCH Z Z BREAD PAN eas —_ Z The nut is held in a wrench socket, which jg clamped in a vise and submerged in oj In operation, a nut or other prodye|} | thit to be tapped is dropped into the socket, A and the tap, with the weight of the lever |} | is arm on it, started. When the spindle/f | $re4 has gets to the end of its run, the nut starts to rise and continues to rise until jt D passes beyond the thread of the when the spindle is raised and anothe part put in. It is necessary for thei}| W socket to be placed so high that the end/f | i7 ¢ of the threads on the tap, in the lower. =i most position of the latter, will be just slightly below the top of the socket; that TI Holder for Small Taps Made from Auto Valve ECAUSE of the location of the holes in a recent small tapping job, I could use neither a standard tap holder or the plate handle for them. There was room for my fingers, and nothing else. The accompanying illustrations show a holder I made to meet this emergency from an old An emergency tap holder for use in close corners Ford engine valve. The tap, of course, is tightened by turning forward the 54-in. nut. For my lighter taps, it seems to please the hand a little better than several other expensive T-handle holders I have. It is a good kink to re- member. How valve was con- verted into holder An Angle-Iron Timber Hanger A= hanger can be made cheap- ly and easily from a piece of stand- ard angle iron. Two cuts are made in the leg of the angle at a distance apart equal to the width of the timber to be is to insure the product's being pushed poe on to the plain shank in every case and 7 thus to allow the next part to slip on, ve ( abili will held, and holes are drilled for the spikes If or lag screws. Then the angle iron js bent and fixed in place.—F Rep Fisuer, — se @~SUPPORTING TIMBER (eq As ANGLE IRON shou SPIKES OR A LAG SCREWS whe with spec ness Al | | neve How a length of angle iron is cut, drilled whet! and bent to form a hanger for heavy timber T a } | avoic 1 | posit Inside Calipers Serve as face Surface Gage Substitute [), It heav HERE a surface is to be set wi | 2 flat on the milling machine or plane pea parallel to the table, a pair of inside calipers will serve in place of a surface Testing a set-up with. inside calipers y make sure the work is parallel with table gage. The caliper spring is held on @ table and the fingers are placed so asW§ prevent the upper point from tippimiiy sidewise. The lower point, is kept i contact with the table.—J. F. HARDECKER ul tect © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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t, which ig ged in oil ler product the socket, of the lever the spindle e nut starts ise until it of the tap, nd another } ry for the hat the end | the lower. will be just socket; that ing pushed ry case and slip on, r the spikes igle iron is D FisHEr. ~ut, drilled avy timber calipers with tab | | | July, 1927 POPULAR SCIENCE MONTHLY _———— Old Bill says— HE mechanic who is good at mak- Ting excuses is seldom good at any- thing else. About half of the resistance of a tap is caused by friction; indeed, this has a ter tendency to break the tap than has the actual cutting. Don’t tie your good ideas to a cloud; they may always remain nothing but mist. Where extreme accuracy is required in the measurement of angles, a sine par will give more satisfactory results than a bevel protractor. The sine bar is not as difficult to use as many young mechanics imagine, yet it is capable of determining angles to fractions of a second. You need never brag about your ability or what you can do; what you do will speak for itself. If you have trouble with chatter marks. when grinding, probably the wheel is out of balance; correct this or select another wheel. As there is pride in ownership, there should also be pride in workmanship. A diamond ffor truing grinding wheels should not be used too long without resetting and it should be in- spected frequently for cracks or loose- ness. Always set a diamond below center, never above; and flood it with water whenever possible. Take light cuts with the diamond to avoid overheating and change its position frequently so that a large sur- face is never in contact with the wheel. It is important to remember that heavy cuts and no water wil] soon wear a flat spot on the point of the diamond; this causes excessive heat and is apt to loosen the setting. Guard for Tapeline Case Made from Old Inner Tube oe tapeline cases will stand some throwing about in the tool box, or dropping on the floor, but this is not so of the type with composition sides and a brass rim. The brass soon loosens from the sides and the case comes to pieces. To protect this type of case from abuse, a section of held on ced so a8 om. tippili is kept mg [A RDECKER | | inner tube about 134 in. long can be stretched over it as is shown. A hole is cut to permit the Rubber binding pro- tape to unwind.— tects edges of case F. W. B. Carried by Hardware Dealers Everywhere WE SUGGEST No. 108—8 x 2 x 1 inches No. 109—6 x 2 x 1 inches No. 110—7 x 2 x 1 inches Send for catalog P-1 for complete list of Carborundum Products Registered Trade Name used by The Carborundum Com- pany for Silicon Car- bide. This Trade Mark is the exclusive property of The Car- borundum Company. An edge tool is only as good as its edge Always keepa CarBoruNDUM Stone handy ou can trust your finest edge tools to a Carborundum Com- bination Stone—the stone that always gives a better edge quicker. Keeps every edge tool in perfect working shape. There is no other material that is so hard and sharp as Carborundum and it cuts an edge on your tools amazingly fast. Carpenters, craftsmen, the man who has a set of tools at home—all users of edge tools should complete their tool kits with a Carborundum Combination Stone, It is made with one side coarse grit for taking out nicks and bringing the tool to an edge—the other side fine grit for giving the smooth finished edge. Every stone uniform in grit and grade. It will not wear unevenly— lasts a life time. Always has a free cutting action. Will not readily fill or glaze. You can use this stone dry or you get a smoother edge by the use of oil. arborundum REG. U. S. PAT. OFF. THE CARBORUNDUM COMPANY, NIAGARA FALLS, N. Y. CANADIAN CARBORUNDUM CO., LTD., NIAGARA FALLS, ONT. Sales Offices and Warehouses in New York, Chicago, Boston, Philadelphia, Cleveland, Detroit, Cincinnati, Pittsburgh, Grand Rapids, Milwaukee The Carborundum Co., Ltd., Manchester, Eng. Deutsche Carborundum Werke, Dusseldorf, Germany D-sign, Workmanship, and finishofthe high st order are found in all Gerstner Tool Cases A 2c STAMP road to success. See Money Making Opportunities on pages 116 to 135. —will start you on the ‘or Toolmakers and Machinists They eiogee. Write for H. GERSTNER & SONS 543 Columbia St., Dayton, 0. It’s Easy to Build Made in two sizes. to cut 2%” stock. dadoing, sanding. Driven by any % to &% h. p. motor. Attaches to light sock- et. Sold with or without motor. Send 10c for de- scriptive catalog of bench saws, drills, jointers band saws, an lathes. W.8. & J.E.Boice Dept. P.S.7-C {AW BUILD YOUR OWN W\| GRANDFATHER'S CLOCK i rints and instructions. Buy from us at surprisingly low rofit building artistic clocks as as $5.00. prices. Ask for at- f AMERICAN CHIME CLOCK CO. il 1603 RUFFNER STREET © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. —when your ripping, mitering, grooving. etc., are done on the Boice-Crane Handisaw Swings saws as large as 8” Attachments for grinding, Toledo, Ohie 3

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ne ne Se SR Na DOE ae ee ene ee O need now to let cracks or holes in walls and ceilings make a room look shabby. With Rutland Patching Plaster you can easily and quickly fix them like new. You just mix this handy plaster with water and fill the crack or hole. The patch will be as lasting as the wall itself. Rutland Patching Plaster willnotcrack, crumble or fall out. It will not shrink as plaster of paris shrinks. It’s easier to use than plaster of paris because it does not get hard or “set” instantly. Paint, wall-paper and hardware stores sell it. If your dealer hasn’t Rutland, we will mail a package direct and you can pay the postman 30c. plus postage. Rutland Fire Clay Co., Dept. R-10, Rutland, Ver- mont. atl ) Salas vee TER " _s oe - Rutlan Patching Plaster MAKE BIG SPARE-TIME.F - MONEY ' Have fun playing for dances, and \ get good pay for it. You can be § ready in sixty days with a True Tone Saxophone If youcan whistle atune youcanlearn “| to play a Buescher. 3 lessons given onre- quest with each Buescher Sax’ give — quick, easy start. Many learn scales first hour, tunes first week, with Bueschers. Easy to Play — Easy to“Pay Take any Buescher Instrument home for six days’ trial. See what you can do. If you de- cide to keep it, pay a little each month. Send for the Beautiful Catalog and the details of this lib- eral plan. No obligation. Mail the coupon today. BUESCHER BAND INSTRUMENT CO. 2019 Buescher Block Elkhart, Indiana r j BUESCHER BAND INSTRUMENT CO. 834A | 2019 Buescher Block, Elkhart, Ind. | { Gentlemen: Without obligating mein any way please send | me your free literature.Mentioninstrumentinterestedin. | POPULAR SCIENCE MONTHLY Hints on Using Taps and Dies (Continued from page 78) and consequently can be used anywhere that a regular hex nut will go. A set of these dies sometimes will save you the trouble of taking a motor apart. An- other way in which these dies will help is by using them on your rough work so as to save your more expensive dies. Before starting a tap, reference should be made to a tap drill chart to see if the proper size drill has been used. Never use a monkey wrench or an S wrench except in cases where it is ab- solutely necessary, as in a corner when a small ratchet wrench is not at hand. AVE the work perfectly level and rigid before starting. Take care that you start the tap true. When the tap has caught, take a look to make sure that the tap is straight in the work. If it is not quite true, turn the tap backward and then forward again, pressing in the direction to straighten on the forward stroke only, and using an even pressure on both arms of the tap wrench. When you are tapping steel, use a continual application of Jard oil and take care not to force the tap. If the tap seems to stick, turn it back and start over again. This will loosen the chips. Never use a large tap wrench on a small tap as you will probably break the tap. Cast iron is best tapped dry as the chips crumble easily and do not form long curls. Never use machine oil as a lubricant on any kind of tapping; indeed, the tap will cut easier dry. When threading a rod with a die, place it upright in a vise and file off any burrs that there may be on the end of the rod. Later, if the die does not catch well, take a file and make four flat bevels at equal distances around the end of the rod. This will enable two or three teeth to take hold at once. After the die is started, make sure that it is straight. Do not use much force on the die stock and use plenty of lard oil. It frequently occurs that you want to have a tap cut oversize. There are several methods of doing this. One is to pack the groove with some cotton waste or a rag. Another is to heat the tap in boiling water and do your tapping with the hot tap. The first method is the better. N AGGRAVATING job is trying to remove a broken stud. The easiest method is by means of one of the several good screw extractors that are on the market, but one of these is not always available. Try pouring kerosene around the stud and let it stand for awhile. It will penetrate between the threads and usually loosen the stud. If a piece of the stud protrudes beyond the hole, it can be removed with a diamond point chisel and hammer. Then use a center punch to spot the center of the stud and drill it out with a drill slightly smaller than the size of the thread. After this is done, the hole should be cleaned out with a tap of the same size as the thread. In the case of a hardened set screw, first heat with a blowtorch. Sometimes a broken stud that protrudes. can }y removed by simply filing it square; » filing a slot and using a screw driver, Where the thread is a very fine trouble may be caused because the ny} becomes stripped. A good way to around this is to line the nut with sof solder. Then start it on the bolt ang work it slowly downward. This really cuts a new thread inside the nut. A trick worth knowing is how to make a screw hold in sheet metal. Take , punch with a sharp point and a long taper, the shank of which is the prope size for the tap you are going to ug, Place the sheet metal over the hardie hole in your anvil or over a nut of medium size and drive the punch in at the desired point. This will make a short cylinde into which you can tap a couple of threads to serve for holding a small screy, The illustration on page 78 indicates five errors in tapping, as follows: 4 monkey wreneh is being used instead of a tap wrench. The tap has not been entered straight into the work. Instead of backing the tap out to straighten it, the workman is trying to force the tap toward him. The tap itself is a bottom. ing tap instead of a plug or taper tap; the taper and plug taps of the set of three taps are to be seen on the bench, if you look closely. Finally, the me. chanic has machine oil at hand asa lubricant and it should not be used. Pocket First Aid Kit ECHANICS constantly are mm ning splinters in their hands, get ting cinders or chips in their eyes, suffering other minor injuries. It pa therefore, to have at hand a first aid kit One of the most compact pocket kits is that illustrated. It is contained ins small safety razor case. The tweezers have a short piece HORSEHAIR LOOP TIED ON MATCH STICK Besides iodine and cotton, the case contains tweezers, a needle point and a horsehair loop sewing needle soldered on the hank end, to aid in removing splinters. A hors hair loop, for taking particles from th eyes, is tied on a match stick and th stick is thrust through a cork so that tht horsehair may be kept thoroughly steril inside a small bottle. A fine enam wire such as from the secondary of a Far coil will serve in place of hor Another bottle contains iodine for and scratches. Cotton for use in applyii iodine is packed tightly around bottles.—D. S. Jenkins. © This seal on a radio, tool or. oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. IS We edge teetl expe: be sr widt! the e on e

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July, iy les can be square; gy y driver, y fine ise the aa way to get ag e bolt This realy ut. ow to make ]. Take g and a long the proper ing to use, the hardie t of medium the desired rt cylinder! couple of. small screw, 8 indicates follows: 4' 1 instead of s not been -k. Instead raighten it, rce the tap s a bottom. taper tap; ' the set of the bench, y, the me- hand asa be used. | Kit y are rub hands, get. oir eyes, o s. It pays irst aid kit wcket kits is ‘ained ina rt piece o POINT OF -EDLE SOLDER TWEEZERS se contains rsehair loop the handk ors. A horse es from th ick and th : so that the ughly s 1e enali ry of a For f horsehatt ine for a » in appl around re 6. July, 1927 _— | Expanding Chuck for Use in Finished Holes INIONS, sprockets, or the like which Prove holes machined before the out- side diameter is finished, can be handled efficiently in the chuck illustrated. Theuse of this chuck saves many trips to the arbor press, for the chuck stays in the spindle of the lathe and expands into the finished hole. It consists of a shank to fit the lathe spindle, a tapered pin, a bushing split in JAWS YL). Device for holding work in which a hole has been machined before outside is turned three places, a nut and a stiff spring. The bushing expands when drawn toward the spindle by the nut. The spring releases the jaws when the nut is loosened. All parts are made of steel, and for severe use should be hardened and ground. Jaws to fit holes of several sizes can be made, if required, and used with the same shank. It may be advisable to tap the rear end of the shank for a draw-in rod.—G. A. LuErs. Substantial Horse for Shop Use Made of Iron Bars ONG bars in the power hack saw or on the drill press must have their free end supported. An empty carbide can is sometimes seen as the support, but it is seldom the correct height; and wooden horses such as carpenters use are easily broken in the machine shop. Illustrated is an adjustable iron horse made of flat bar iron that can be used in connec- tion with the hack saw, drill press, shaper, or milling machine. Of course, if it is to be used for the miller, it will have to be made higher than shown. The joints are made with %- in. rivets or bolts. —W. S. MILEs. Adjustable stand for supporting long stock Grinding Chucking Reamers NEARLY all chucking reamers are 4 made with unequally spaced teeth. It is well to bear in mind that if the cutting edges are ground as in a reamer with teeth evenly spaced, trouble will be experienced. There is only one way to grind such a reamer. The chamfer must he spotted off cylindrically to the required width and each tooth must be cleared to the edge by raising or lowering the set-up on every index. The reamer will then start cutting evenly.—H. J. C. POPULAR SCIENCE MONTHLY Water Fam Open to youg | C€ 7° WHERE nature is ~undistitbed ee wheal Re" changing vista of the great Out-of-doors leads through —. mile after mile of unsettled country and winding waterways. With a Johnson Motor astern of any good boat, you may cruise through chain after chain of charming water regions— fishing, hunting, camping as your fancy dictates. { This summer follow America’s water trails with a Johnson. fi Four new 1927 models offer speeds of 8, 13, 22, and 29 miles per hour respectively— setting a new standard of water- motoring performance. 4% Send 10c in stamps or coin for our “Guide to Waterway Travels” —outlining over 50 charted water trips through the United States and Canada. Catalog sent free! © is Johnson Motors sold by sport goods —hardware—marine supply dealers JOHNSON MOTOR COMPANY 2538 Sample St., South Benga Ind = ae oH Export Division: 75 West Street New York, New York, U. S.A. Canadian Distributor- Peterborough Canoe Company Peterborough, Ontario, Canada Johnson National Demonstration eek June 27th — July 4th Water Motoring demonstrations. Free trial and rides. Races! Ask your dealer. , WORLD'S LARGESI e a dg SS LS > ————— Wood In A Can ~may be sawed and worked with tools / Surprising, yes, but here it is. PLASTIC WOOD handles like putty as it comes from the can. It hardens on exposure to air into watertight wood which takes paint, stain, lacquer and varnish like any wood. Use PLASTIC WOOD wherever wood needs replacing. Use it in boat construction, for repairing furniture, in cabinet work—in fact in any woodworking job. Sold by Hardware and Paint Dealers—'4 lb., 35c3 one pound, $1.00. Send coupon if they cannot supply you. INSURANCE The ECLIPSE Nut Lock for disc wheels protects valuable automobile equipment from theft—for less than the cost of a new tube. The ECLIPSE is rust-proof, fool-proof and tamper-proof. each postpaid — sB specify make and size of wheel. At your dealers— or if he cannot supply you send his name we will supply you direct. ADDISON-LESLIE CO. 30 Bolivar Street, Canton, Mass. Finesse pend me a trial quantity of PLASTIC WOOD for which | en- close ° Name. ASSOCIATED INDUSTRIES CORPORATION Pomona, Calif. Address Name and address of Hard ‘e Dealer © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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nearest ee eee ee ee

seit free aaa ee ene eace ET os a taaingatg APN eee

108

Morning to night—your hair smoothly in place) “I Can’t Get "Em Up,—” ae **I can’t get ’em up in the morn—ing. So complains the bugler. But your problem is different. Stub- born, pestiferous cow-licks—you can’t make them lie down in the morning! And an hour or so after you brush your hair it’s generally out of place again. But that need not be so, today! You can. keep your hair smoothly in place, all day long. From Coast to Coast, the hair dress- ing more fellows use than any other is —Stacomb. ‘Stacomb not only keeps your hair looking right. It is also beneficial. Never leaves hair gummy nor sticky. Nor dried out, as frequent wetting with water makes it. And it helps to prevent dandruff! Stacomb comes as a combing cream—in jars and tubes—and now in the popular new liquid form as well. All drug and department stores. FREE OFFER fe ead

Standard Laboratories, Inc., t. BC-9, 113 W. 18th Street, New York dd me free sample of Stacomb as checked: Original, cream form [] New liquid form 0 MDa ddkd ct csicn needa wena owedesekes 0

For your home shop! Combination 11-inch band saw and 1l-inch wood-lathe. If you have a knack for woodwork- ing you can turn out first-class bridge lamps, cabinets, furniture, ship models, etc., in fast time. Get one! Write for specification circular. THE PARKS WOODWORKING MACHINE CO. 1547 Knowlton Street Cincinnati, 0. POPULAR SCIENCE MONTHLY

Suny, i997

BURN YOUR NAME ON TOOLs |

How to Straighten Hardened Parts ECHANICS do not generally realize that it is possible to deform hardened steel permanently by pressure applied while the part is heated at a temperature of anywhere between 500 and 600 deg. F., or from a deep straw to a deep blue. This little known fact can be put to good advantage in straightening parts that have become warped in quenching. No matter how careful the heat treatment may be, there are always apt to be occasional parts, especially if the work is long and slender, that will be- come warped to an extent which will render them unfit for use. Reharden- ing such work often merely aggravates the trouble and,even if successful, is not best for fine steel. In many cases, how- ever, such pieces can be straightened during tempering. The writer has always done the straight- ening in a liquid salt bath, but no doubt it can be done, though less easily, over a flame. The part should be drawn to the highest possible temperature and allowed to cool again. The piece then is placed by means of clamps under a tension in a direction opposite that of the warpage. Two of the many methods which may be used are illustrated. At the left, a small shaft is being straightened in a Two methods of clamping deformed steel parts to straighten them

——__ simple clamp made from a couple of blocky of cold rolled square stock and a bolt, At the right, a thin flat piece is being “ironed out” with the help of a pair of machinist clamps and a stout bar. It will be note that there is also a small spacer betwen the two pieces on top, to prevent over. doing the straightening. By placing sug, ‘a spacer to one side only of the work, twist can be takep out from a piece af the same time that the bend is removed, Where a fairly heavy piece is con. siderably warped, it should be straight, ened by degrees by repeatedly subject. ing it to the process, each time allowing the piece to cool until it can be touched. After the work is in the desired shape, it should be allowed to get en. tirely cold. It should then be re-heated a third time to the drawing temperature— the clamps, of course, having been re moved—to show if there is any tendency for it to return to its former shape. Judgment must be practiced in ap

plying the corrective strain to the parts so as not to crack them. The writer has had occasion to reclaim by this simple process and at the expenditure of only a very little time in each case, some valu able pieces which would otherwise have been a dead loss.—HeEnry Simon.

Using Micrometer to Measure Work with Concave Face LLUS- TRATED is a set-up of a micrometer with a short piece of drill rod held on the anvil to aid in check- ing a small part having one side concave. Tiwo small parallel clamps grip the rod,while a larger clamp holds the smaller ones. Sheet Metal Holder Keeps Acid Bottle from Spilling HE accom- panying illus- © tration shows a sheet metal holder for bottles contain- ing acid, gasoline, or other liquid. It can be set upon the

How testing is done with aid of drill rod

cot and nest tools and foetrumenta,o¢ 4 bench alongside cia bottle holder from an ordinary pen or» Complete Outtit whatever work is that tilts forward T-bolt, two nuts Eas circular free. Write to- Ht being done. - and any screw of Making a common pe BEN CO. 5 <= ED The holder is so arranged that when the _ suitable length. T-bolt longet bottle is tipped forward the liquid comes out in drops through a groove cut into the cork. When released, it returns to a sale position. The holder is made of No. lf sheet steel. The bottle clamp is lightly riveted to the frame.—ArTHUR KENDALL

SHEET METAL - CLAM

BOTTLE | SUPPORT |

ONE-PIECE SHEET METAL FRAME The bottle is held in a sheet metal clamp, which is pivoted in a light but rigid frame

Lengthening Short T-Bolts | CCASION- ALLY a job comes into the shop that requires the use of extra long bolts to strap it down on the ma- chine bed. If these are not available, they can be im- provised as shown

© This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

quently anothe1 there a than bo Soft LI mac! lathe ch ists ha pieces ¢ should « the jaws

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Juty, 1977 of blocks bolt. At “ironed chinists’ be noted between nt Over. INg such work, a € taken piece at ime that ‘emoved, Rs fairly 2 18 Con. arped, it straight. grees by subject.

July, 1927

POPULAR SCIENCE MONTHLY 109

aS Using Twin Angle Plates to Mount Lathe Work SSIBLY there are some machinists who do not fully appreciate the use- fulness of angle plates in connection with Jathe work of a character similar to that illustrated. This is a casting that cannot readily be gripped with the usual four- jawed chuck. The first thought would be to send it to a boring mill, but if a mill is not available, some other method must be To handle such a casting with angle plates, one of them is clamped to the

HOLDING BOLTS LATHE FACEPLATE BORING BAR How to mount on a lathe faceplate work that normally requires use of boring mill

faceplate of a lathe and the casting put in place and centered approximately. Then the other angle plate is bolted on for rigidity. The numerous holes in the plates can be used for bolts, or, if tapped, for set screws for locating the work more pre- cisely. The angle plates can be made of cast iron, or in an emergency, of heavy steel plate. Machining time on the lathe will fre- quently be less than on a boring mill, and another advantage of this method is that there are always more lathes available than boring mills. Soft Jaws for Lathe Chuck _ cremmged parts requiring further machine work cannot be gripped by a lathe chuck without mutilation. Machin- ists have used cardboard shims, loose pieces of brass, and the like to prevent this. A better way is shown in the up- per part of the accompanying il- Justration. Brass plates are formed to fit on the chuck jaws in such a way as to grip tightly and not slip off when the work is removed. The lower view shows a method more limited in scope, which may be more desirable where it can be used on duplicate work. ~A_ brass , ring is made and split to allow it to open and close with pressure. This ring can be made fairly thick, and will distribute the jaw pressure over a large area. Properly made, it should open up to release the work when the jaws are Joosened.—G. A. L.

Using brass to protect Polished work in lathe

Simonds Inserted Tooth Saws ake short work of heavy, tough metal-cutting jobs. The plates of wear-resisting steel are tempered to give maximum strength and stiffness for heavy duty cutting. [si High Speed Steel Teeth of m SIMONDS SAW AND STEEL COMPANY _ “The Saw Makers” Established 1832 ; Fitchburg, Mass. Branches and Service Stations in Principal Cities

SAWS THAT CUT METAL FASTER

eK: | oe i ™

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a an juipment Included in Price of Lathe ‘ VEO Has. All These Practical Features NVQ \ v Co \ \ \\ FIUNIOR FES) SRE CERTNG \e x CR LATRE \ SHEE SH» VES

Back Geared Head Stock; Six Spindle Speeds; Power Feed to Carriage; 3-4 inch hole through Spindle; Plain or Graduated Compound Rest: Micrometer Graduated Collars on Cross Feed and ‘ompound Rest Screws. Cuts screw threads 4 to 40 per in. left or right hand. Built in 2 1-2, 3, 31-2, 4 and 4 1-2 foot bed lengths, either Bench or Floor re A precision lathe, limit of accuracy one thousandth (.001”) of aninch. Weight 375 Ibs. The Lathe can be equipped with Motor Drive, operated by a quarter H. P. Reversing Motor that plugs into ordinary lamp socket. Comes complete, ready to use, FREE BOOKLET 22-K—Just off the press! 24 inter- esting pages of practical lathe information. 133 photographs. Tiestentes the lathe doing different classes of jsion work, and describes various types and drives. A book- et of real interest and value to any Mechanic, SOUTH BEND LATHE WORKS 836 East Madison Street - South Bend, Indiana New York City Salesroom, 183 Centre St.; Phone Canal 9085 <_< vey b eae oa rsh a he a: at Fue FS)

SE ee OE Se Ym ee ee r1S] This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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BENDS ANAT ANA ATANTAN TAN ZANT AN SEE MILES AWAY! er Distance! Bring tion Resse Special Petes STLY Binoculars—G Famous ll GUALITE lonscel’ Net 6. no oy 8, Bae A io. POWER (10 times max. ni )—exa' definition—| llumination—wide field of vision—30 MM, .maki it possible’ tte ahs swiftly Imoving ob! objec without moving the Complete ee with se Wand meet Straps. U; ly, Soid for why He | A 5-00, To . yt our tical Division * Direct -by- a we price it. for LIMITED TIME, at onty $27. TESTED by the GOVERNMENT Bureau of Standards at Washi . Used o8 by a, ft and Navy Offi- cers and Commanders. ted rial and observa- tion! We are eclling t oeeke ab ‘at this Special Be Reresin ia Price to big Game | ry cs, Gre a xplorers ourists Motorists: , Mountain Climbers, Sportsmen men an en al over the World! DON’T MISS th es that BINOCULARS will give you! ORDER YOUR yates —TODAY! _ comment. We ask for NO money in Advance. Nothing ‘ on Delivery. We send BIN- 46 Difprent: OCULARS for 10 Days’ trial sible persons. i If pleased, on aw oe on . a Plan: D: Vy 5 ghee enti at pay ro at oss 7) “10 ct $2 and $ 50 TLEME. herwise return Order NO Wi Limited Quantity! SEAVER-WILLIAMS co. | | | 2 Generations of Honorable Dealings ’’ | 365 WASHINGTON STREET, BOSTON, MASS. rgeat 3 of B in the World | Sontiomen: —Send me $27.50 BINOCULARS 10-POWER for 10 D it 4s arousing natton-wide Absolutely FREE to respon- Teac Order er for $26. 50 in PULL “SET Importers, Exporters, International Mail-Order House E Trial on the above p one : Se oo Pm, velit cppreciate ond re senect the some * r | information, “TH aNK YOU. 7-27 Poe} 8 ORY a ee TELLS ALL ABOUT THE 15 New Features as well as the many other features of the wonderful Motor that thrilled the soars in 1926 by its remarkable speed and power. You will want to kno pecially about “The Pilot” —a NEW device thee steers your boat in any course you choose — straight or curved, without ae f — -agael one. Leaves you free to cast, or troll or rest. T: LOCKWOOD BOAT @ ‘MOTOR: of S in Stop ° Pind ein boa tor. Get the facts now. WRITE FOR FREE FOLDER oe a anced engineering methods backed (wo be. marine engine building OCcCKWw I MOTOR ween 717 Jackson Se. POPULAR SCIENCE MONTHLY 19 J uly, In July, His Strange World Came True (Continued from page 38) furnaces with enormous calorific power . Water will be the coal of the future.” Needless to say, here Verne fell into the same error as the inventors of perpetual motion machines. He did not realize that it would take, theoretically, an equal amount, and, practically, a greater amount, of energy to decompose water into hydrogen and oxygen, than the two gases so obtained could generate by their reunion. But think when Verne wrote this! And—getting back to his balloon story— who knows but that men may yet be able to spend five weeks in a balloon, and cross a continent? HE greatest of Verne’s stories of the con- quest of the air is “ Robur the Conqueror,” which appeared in 1886. Even at that time Verne anticipated the controversy between proponents of lighter-than-air machines and advocates of the heavier-than-air type. In “Robur the Conqueror,” Verne has the in- ventor of a heavier-than-air machine kidnap two champions of the lighter-than-air type, and take the amazed victims on a nonstop flight practically around the world. The two kid- naped men finally escape—still unconvinced— and build a lighter-than-air machine. Verne’s climax is reached when this lighter-than-air dirigible, making its trial flight, is crashed into and brought to earth by the heavier-than-air Albatross. The scientific prophecy which Verne made was the prediction that the heavier-than- air type would prove more practicable than the lighter-than-air type. To date, Verne has been correct in this pre- diction—although the matter is not yet settled. Experiments are today being made with the rigid dirigible which may bring the lighter- than-air type into the lead. The fascinating thing about “Robur the Conqueror” is Verne’s description of his air- craft of the future, the Albatross—a flying machine with a body of compressed paper, lifted and held in the air by seventy-four hori- zontal screws and propelled by electric motors actuated by batteries of “secret’’ composition. HE most obvious error in Verne’s guess was in connection with the nature of the power employed. Again, the expectation sug- gested in “Five Weeks in a Balloon” —namely, that battery units of tremendous power, in proportion to their weight, could be devised— is evident. Verne apparently had the idea that substances would be discovered which would give an almost inexhaustible flow of electricity merely by means of, the chemical energy con- tained within them. Verne’s airship might be compared with an electric automobile whose battery never needed recharging. Unfortu- nately, there “‘ain’t no such animal” yet. Furthermore, if such batteries should be devised, the weight of the necessary motors alone would be greater than the weight of a gasoline engine capable of producing equiva- lent results. It was the “explosive mixtures capable of producing mechanical motion’’—which Verne discarded—which actually became the motive power of the modern airplane. But how could Verne have guessed that in 1886? Although the gas engine had been invented nine years before, it was still little more than an experi- ment. Steam had by that time been tried out, and he recognized its limitations. Electricity was just coming into its own, and it is not strange that Verne expected it to perform miracles of which present scientific knowledge shows it incapable. The screws mounted on perpendicular axes, which enabled Verne’s machine to rise straight from the ground without any forward motion whatever, have not materialized. In this, did Verne make a mistake?—or was he even ahesp! of our own time? Inventors are still work | on this idea today—the helicopter. Thug ga) they have been only partly successful, Bute we say that it cannot—will not—be done? In 1905—the very year of his death, w Jules Verne was seventy-seven years old wrote a third story of the air, which he call “The Master of the World.” In this described a machine capable not only of fly) in the air but also of sailing on water, trayelj under the water, and bounding along Toads 4 120 miles an hour! In short, The Terror, ag calls the contrivance, is a combination ub. marine, automobile and aircraft! We of tog have less reason to laugh at such a conceptigg than had readers at the time the book » peared. For the airplane-automobile hag beg! | | produced experimentally, the fiying boat js i TI daily use. Who is to say the rest of ham prophecy is not to be fulfilled? has} Even by 1905, Verne had not given up terir idea that electricity would prove to be t smal master motive power. In the story, the “} clos inspector in the federal police department! we taken prisoner on board The Terror, says; i a HE power by which the machine pull. driven was neither steam nor gasoli fold. No doubt it was electricity, generated board, at some high power. Naturally, Cc asked myself whence comes this electricit H.A from piles, or from accumulators? But were these piles or accumulators ch Unless, indeed, the electricity was d directly from the surrounding air or from ff water, by processes hitherto unknown.” At this, we laugh. But— Should we? Of course, Verne, in his “ Master of World,” is wildly melodramatic. He has Th Terror enter an automobile race, the finishd A 2c which was at Chicago—win the race at §— road to miles an hour, and disappear into la&§ Opportu Why | Michigan! He has it flee from two submani destroyers at Buffalo (there are no destre at Buffalo, and never were) by diving ¢ the Niagara River—and, just as it was to go over the Falls, taking to its wings flying away! Nevertheless, much can be said in Ve defense. He began his prophecies of invei in the sixties. By 1905—when he “The Master of the World ’’—mechanie vention had progressed at such an uw edented rate that Verne no doubt felt hi justified in assuming that the future bring new inventions at a still more rapid pit ee } sample and ; HAT happened, as we of course ki Factory was that the years 1905 to 1927 hang Sam Frees been utilized not so’ much in discovering new principles, as in perfecting the cation of principles hitherto discovered. ~ Me But what of the future? What of electro a radio-activity, and the relationship betweiy ———— electrical energy and the constitution of th individual atom? Scientists tell us, toda that the atom contains within itself mm energy than Verne imagined in his wilde dreams! Some day may we not learn how get at that energy, and put it to work? So we cannot be sure that Verne was fe pad sowabe . b than ¢c! wrong, even as to his strange assumpt tow to do it, concerning sources of electrical energy. pty Po EXPERIMENTS using a million volts will shot be made with cathode rays, according recent announcement of Dr. A. Lincoln shall, of the General Electric Company, ciated with Dr. W. D. Coolidge in the deve ment of the cathode ray tube. So far highest voltage applied has been |b million. © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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en ahead? l wo cing | US fag, But cay lone? | th, wi | S Old—~fg) he call | this f of fly i travel x roads, At all lead- -rOr, ag ing hardware dealers. Or write us. tion sy > of tod t onceptig book Ron This perfectly balanced 1-pound st y hammer is made of tool steel. It has chisel-edged claws, without al- en up tering the claw feature. It has two to be small claws right and left to reach the “he close corners next to wall. The artmen head is correctly balanced making aaye; it possible to remove 10’s at one cafes pull. Write for fully illustrated > gasol folder. erated turally, Chisel-Edge Claw Hammer Co. electrici H. A. Ayvad, Hoboken, N. J., Dept. E But ues CHISEL - EDGE- as dra ‘foi? CLAW HAMMER vn.” —will start A 2c STAMP [wit srt road to success. See Money Making Opportunities on pages 116 to 135. Why Suffer With That Pain This moderately priced Therapeutic Lamp bakes out pain. Physicians highly recommend it for Bronchitis, Stiff Neck, Ovarian olds, Neuralgia, and all pains caused by congestion and poor circulation. | i Complete with 260 Watt Bulb, 8 feet of cord, two piece standard plug} can be attached to any regular electric light socket. Shade and reflector made of alu- minum, diameter 7 1-2 inches. Send no money,pay postman $5.00 (plus a few cents postage) on receipt of lamp. DANIEL LEVY 2353 82nd St. Brooklyn, N. Y. Dies Acents Wanted a from ~ 44 Styies, colors and /#aat Spsant matctocnaye acne AO A Factory We ship on sy ba eset doen Wastbev. fis . horns, wheels, ..equip- |W Tires ment gndrapaire stb usual price, \ Cycle Company Write us Mead Dept. P-250 Chicago freszaisiog eeDaiks Breed squabs and make money. Sold by millions at higher Prices than chickens. Write at once for two free books telling how todoit. One is 40 pages printed in colors, other 32 pages. for Books 3 and 4. You will be surprised. Plymouth Rock assumpti TEy: Squad Company, 616 H Street, Melrose Highlands, Massachusetts. i BUILD AND FLY A will sh MODEL cording AEROPLANE ance ee Learn the principles of Aviation npany, with an accurate el of a real "plane. Ideal Bullding-Fiying Instructions show you how. | Drawi truc- for any one of the following "planes sent postpaid for 25 cents? Ly ay Plane: Curt a JN4D-2 hraiging Plane; DeHavil- + NC- i or Tau ono z acer. 48-pp. Catalon of Pacts d Supplies—Sc Pp. Pp. the deve So far$ een Of Racer. 48-pp. Catalog of Parts an 163-165 s IDEAL AEROPLANE & SUPPLY CO. es York City POPULAR SCIENCE MONTHLY Floods Challenge Science (Continued from page 19) crest of waters began its advance down the lower river. Strange to say, most experts agree that the very earthworks the inhabitants have built are the source of greatest peril during a flood | like this. Time was, before white men came to America, when the great river went its own good way, and settled its own flood problems by spreading out over the land where it willed. But with advancing civilization men have pushed the river back, guiding it by two thousand miles of embankments into an ever narrowing channel, reclaiming fertile farm lands. Silt deposited on the river bed has further restricted the channel room for the flow of water. And so men have had to build the levees higher and higher. In recent times $10,000,000 has been spent every year to raise the dikes. T IS because the levees have failed time and again that engineers have proposed other plans for controlling the floods. One of these would call for the establishment of huge reservoirs at points along the main stream and its tributaries, into which excess waters could be drained. To this plan the objections have been raised that such reservoirs would render worthless immense areas of rich farm land; that the cost would run into billions and would be out of all proportion to the partial relief that might be given; and that the reservoirs could not be relied upon to be empty when most needed. Another proposal is for spillways at intervals in the levees, with channels to lead the excess water to other streams or to the sea. This, in effect, was the purpose of the engineers recently when they deliberately dynamited the Poydras levee below New Orleans in an effort to save the Louisiana city by lowering the water level. The chief objection to this plan is that the relief is only temporary and local. Reforestation of cleared lands has been sug- gested. Indeed, the denuding of forests is held by many as the primary cause of the Missis- sippi floods. To this engineers reply by recall- ing that the worst flood ever experienced in St. Louis occurred in 1844, when the virgin forests had barely been touched. Weather observers add their records to show that the high waters on the average are no higher than they were half a century ago. Where forests have been cleared, they point out, farming has kept the soil so broken and permeable or so covered with vegetation that it absorbs rainfall about as effectively as forest land, if not better. ge the majority of engineers and scien- tists who have studied the problem have fallen back on the strengthening of the levee system and the deepening of river channels as the greatest hope for the future. What they | urge is the construction of a great new system of dikes designed scientifically to withstand pressure greater than the greatest conceivable flood can produce. Today the levees are little more than banks of earth rising forty feet and more. In some places they are reinforced: with planking, brush, or concrete piling. In flood time they are topped by bags of sand. As the flood pressure grows, armed guards patrol the em- bankments, ever watchful for muddy seepage, first sign of a leak. Sandbags sunk on the river side of the levee may stop the leak in time. ; The whole tragic battle with the Mississippi has been one of courage and resourcefulness against overwhelming odds, fought from be- hind ramparts that are penetrable and scien- tifically out of date. Like every other war against a powerful enemy, it will not have been in vain if it inspires new determination to build defenses that will withstand all tests. 111 ~the police special and sport solo Varo praise it. New riders welcome it. Already a coast-to-coast motorcycle sensation. That’s the startling story of the new Indian Scout 45—a mount winning thou- sands to the biggest thrills of motorcycling. For real, rugged outdoor sport, hop on the Scout 45. It’s the steadiest, sturdiest, snap- piest mount you ever rode! Ride the 45 a Mile The Scout 45 has a super- powerful motor,almostinstant acceleration, large oversize brake, classysport handle bars. Holds boundless power for the veteran rider, easy handling features for the novice. Guides you quickly through traffic— out to the open—anywhere, anytime—safely! Ride the 45 a mile —and find the full meaning of its amazing country-wide popularity. Easy to Own Call on your nearest Indian deal- er and find how easily you can own a Scout-45 under our generous pay- as-you-ride plan. Or mail coupon below for the complete interesting story of this popular model. DEALERS! A few good territories open. Our proposition is a winner for ambitious men. Writenow, Sndian Molocyele Co __ ___Dept. H-7, SPRINGFIELD, MASS. -. Indian Motocycle Co., Dept. H-7, Springfield, Mass. Send me FREE descriptive circular on the new Indian Scout 45. This places me under no obligation. Name © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. tra REP OS AA re SM

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cAnnouncement Sterling “*@” LIGHT-SOCKET POWER UNITS They're here—two perfected light-socket power supply units—eliminators of all “A’’ batteries and chargers. Two models—R-96-Raytheon for 6 volt and R-94-G.E. bulb for 4 volt, Radiolas especially. Sterling model R-96 is universal for all sets using 3 to 10 large tubes. Employs Ray- theon’s new 2 14 ampere rectifier. No heat —no bulb—no breakage—long lived. Sterling indicator makes this unit adjustable to point of highest operating efficiency and lowest power cost. These units have two stages of filter, large capacity, smoothing out the last trace of hum. Automatic switch gives instant control of all power when with “B” eliminator or “B” batteries. One installation, one adjustment—and your “A” troubles are ended. Ask your dealer to show you this remarkable Sterling “A” Power unit. ferling The Sterling Mfg. Company 2831-53 Prospect Ave., Cleveland, Ohio Dealers—pDon’t miss the com- plete Sterling display at the Chi- cago R. M. A. Show, Booth 68. POPULAR SCIENCE MONTHLY July, 197 Radio Specialty Co.,96-P Park Place, New York. N.Y. { “Build your own with ““RASCO”’ Parts’’ Canned Food and Your Health | (Continued from page 22) cation of the various vitamins, without which the finest food combinations seem useless.” Dr. Eddy is the only scientist who claims he has really seen a vitamin, for these sub- stances are really chemical ghosts, invisible to the eye. Dr. Eddy believes he has isolated the vitamin of yeast; that the white crystals resembling snowflakes, in his test tube, is that. If Dr. Eddy’s “bios” is really a vitamin, it shows they are probably necessary to plant as well as animal life, for yeast is a plant. Though Dr. Eddy’s bios is the nearest scientists have come to seeing a chemical ghost, they are sure, thanks to thousands of white rats who have died a noble death, that five such ghosts exist. They are labeled A, B, C, D and E. In fact, the first vitamin discovery was due to rats, for Dr. McCollum, trying to discover the relative feeding values of “pure” carbohydrates, protein and fats, found the rats thrived on none of them, and apparently needed some other element. When he switched to milk and green vegetables, the rats perked right up. The chemical ghosts, then, were in these foods, a fact that had never been actually ascertained before, though people had known for a long time that milk, fresh fruits and vegetables were good for them. | be THE twenty years since Dr. McCollum’s first discovery, doctors and scientists have finally reached definite conclusions about the vitamins, as follows: Vitamin A, or the antixerophthalmic. Necessary for growth. Its lack causes eye ailments. Found in milk, eggs, animal fat and fish oil, particularly cod liver oil, which has 200 times as much vitamin A as butter fat. Also found in fruits and vegetables, including spinach, chard, cabbage, lettuce, water cress, asparagus, yellow corn, millet, carrots, sweet potatoes, parsnips, mangoes, beans, green peas, bananas, apples and tomatoes, the latter being very rich in it. Vitamin B, prevents beri-beri or poly- neuritis. It was first discovered during the Russo-Japanese War when Japanese sailony eating mostly polished rice and fish, down with beri-beri. Change to unpolished rice helped. This vitamin is present in yp, polished rice, whole wheat bread and break. fast food, yeast, most seeds, vegetables, fruits nuts and dairy products. Vitamin C, the antiscorbutic or preventive, is found in most fruits, gree, leaves and tubers, particularly in cab lemons, oranges, tomatoes, apples, stray. berries, carrots, peas, bananas, spinach, gtape. fruit and corn. It is in milk if the cow hy eaten green food. Its presence in citrus fryjts accounts for their being taken on long sq trips. They prevent scurvy ITAMIN D, the antirachitic or enemy of rickets, controls the deposit of calcium jg the bones. It occurs in fish oil, particularly eoq liver oil, egg yolk, milk and some vegetables, Cod liver oil has been found efficacious jp treating rickets in children. Vitamin E, the most recently discovered, js called the antisterility vitamin. It is believed to be the secret of large families, and is foun in the wheat germ, vegetable oils, fresh meats and salad vegetables, especially lettuce.. -: These are the five vitamins in good standing with the medical profession. Others may be in| existence, and at the rate at which vitamins! have been found in the last few years, there is every reason to expect new discoveries, Doctors believe that more and more- use yil] be made of the new life-giving substances i the treatment of the numerous dietary diseases and ailments. The human race travels on its stomach, and if that can be kept working, th’ rest of the body is apt to follow. So Grandma Jones found she needn’t wory about canning taking away all her vitamins After all, vitamins come in cans, she found— sometimes more in cans than in kettles. Gool canners see to that. All that she needs to & is get reliable canned foods and stop worrying Nature will do the rest, Couriers That Never Fail (Continued from page 26) from the landing board of its loft into the trap, or coop. For a homing pigeon that lingers out- side its loft is like a race horse that stops a hundred feet or so from the finish. When the homer has learned this important step, he is taken out for trial flights. These begin a few feet from the landing board and are gradually lengthened until, at the end of ten days, he is being tossed from a point a mile or two away. EXT come flights from points five, ten, twenty, fifty, and even a hundred miles away. The pigeoneer weeds out the stragglers, or birds that don’t find their way back to the loft in good time, for all good lofts—especially in racing—are built on the inexorable law of the survival of the fittest. The long distance flights take place in the fall. Some of these are over 500-mile courses, some over shorter distances. Many birds that are unbeatable at 500 miles show little or no speed in the shorter races. The pigeon that can cover 500 miles in a day, however, is the one that commands a price of $500 or more when put up for sale. A bird that won the San Sebastian, a blue ribbon race of 648 miles from Spain to England, in 1920, was sold to Louis Heitzman, of Louisville, Ky., for. $1086. But it took fifty years of scientific breeding to produce that pigeon. The homing pigeon’s contributions to the happiness and welfare of mankind are many and varied. In sparsely settled sections of Arizona, Texas, Nevada and Montana many physicians find it practicable to use them as messengers between themselves am patients living in distant and lonely placs where there are neither telephone nor telegraph lines. One doctor in Arizona always takes tw birds with him when he goes to these distant places. After treating his patient, he leavesth pigeons with the family with instructions ® release one of them in the morning after placiy a red band on its leg if the patient is ve white one if he is better, and a blue one if condition is unchanged. The second pigédl carries another message later. HE use of homing pigeons by Arctic & plorers and by members of expeditions isla unexplored sections of the world has in many thrilling rescues and the saving @ many lives. Boom towns on our own frontitt especially in Alaska, have found the feather! beauties of great value during those between the establishment of the “town” the opening of modern lines of communicatit Only last year homing pigeons were summon medical assistance to a new settle on Dime Creek, Alaska, when half the m Det were suddenly stricken with ptomaine pout ing. 3 Homing pigeons can stand freezing weallt) high winds and even hail, but they can m® little or no headway in rainy weather despl the fact that they are game to the last drop blood in their tiny bodies. is © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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July, 197 enemy of alcium in ularly cod egetables, acious in overed, is s believed 1 is found esh meats 1Ce,. 3 1 standing may be in Vitamins | ars, there iScoveries, e- use will July, 1927 “pe > yourself allyou need isheat It’s aregular hobby with thousands of people— to fix things themselves. And now, with Kester Metal Mender men, women and boys actually solder! Youtoo,can use Kester Metal Mender expertly right in your own home. Kester requires only heat, is easy to use, and it’s a genuine solder, too! It carries a scientific flux inside itself. Like the lead ina pencil, this flux does the work. Think of how many useful things you could put back into service with just a touch of Kester, here and there. 1d tensil +4 — old ts itl Buy a can today from your hardware dealer, general store, auto supply shop or druggist. If Da want to be convinced without expense —write for Free Sample. lectrical een ess older it! KESTER METAL MENDER The Household Solder CHICAGO SOLDER COMPANY 4207-09 Wrightwood Ave., Chicago, U.S.A. Established 1899 POPULAR SCIENCE MONTHLY ‘ARTE © New Resistors ON HE] Half Size Made in all types for all circuit requirements. See them at your dealers. Send for illustrated folder of circuit suggestions. CARTER Resistors In Canada: Carter Radio Co. Ltd., Toronto CARTER RADIO CO. CHICAGO —_ lee yee og MEMBE RM AS Tube Effi adjusting filament current your tubes require. Eliminates hand rheostats. Simplifies wiring. In- sist on Amperite. Accept nothing else. Price $1.10 - complete. Sold everywhere. Write for Free Hook- Ups and g construction data to Dept. & RADIALL COMPANY } 50 Franklin Street New York City i] The “SELF-ADJUSTING" Rhcostat A’ Vision of Aviation’s Future (Continued from page 33) radio compass, enabling them to locate their positions and chart their courses in the thick- est weather; liners come into New York harbor as safely by night or in fog as they do by day- light, guided by the induced currents from a tiny electric cable laid along the bottom of the Ambrose Channel. With a device to keep the airplane on an even keel and the radio compass improved, mail planes will fly by night as safely as they do by day, and it will be a simple step to guide them to their landing fields by means of just such an electrical device as that used in New York harbor. An induced current from a wire running to the field would deflect a needle to the right or left, indicating that the flyer was off his course, while the intensification of the current as the plane approaches the field can be indicated. By some such means as that, mail and interurban aerial service will become a night-and-day affair. LOOK forward, too, to steady development and increased use of the flying boats, for crossing the Great Lakes, wide bays and gulfs, and flight along river courses. This is the safest form of air travel yet devised, for in case of a forced landing from any cause there is the buoyant medium of the water to float upon. The chief danger here is from storms so severe as to wreck the craft by the action of the wind upon the wings. Nine times out of ten flying boats forced to land on a rough sea have been unable to rise again, because of the waves, of damage to propellers or wings, or of being out of gas. To overcome this handicap, we built, during the war, what may be called the flying lifeboat. This is a flying boat with discardable wings, with a small auxiliary motor and a water propeller. After alighting on the rough water, the wings are detached and left behind. The hull is built like an unsinkable lifeboat. If the air propellers are not damaged, they may furnish motive power to get the craft to land; otherwise they can be thrown over and reliance placed upon the auxiliary motive power and sea propeller to keep the boat head-on to the waves and eventually bring it into port. Air fighting in the next war will be vastly different from air fighting in the last war; safer, too, for the actual combatants. Much that we learned about military aviation in the last war was put into practical form too late to be of service before the armistice. For example, there was the aerial torpedo. We built twenty- five of these, but none. so far as I know, ever got to the front. Few persons ever knew any- thing about them. HE aerial torpedo is a pilotless airplane, controlled by radio, filled with high explo- sives calculated to drop, with its load, after a given number of miles or upon an impulse transmitted to it. We built some of each type. The rudders and elevator are controlled by a clockwork mechanism, which in turn responds to radio impulses from without; balance is maintained by a gyroscope which gets its power from a servomotor actuated by the wind as the machine flies. The controlling mechanism was the invention of Lawrence Sperry, who gave much to aviation and finally lost his life in a flight over the English Channel. Bombing will be done in the next war by these aerial torpedoes, launched from perhaps a hundred miles from the objective, impervious to enemy attack unless struck in a vital part of the mechanism. Fighting airplanes i in the next war will have no “blind spot”’ from which an enemy plane can attack with impunity. That was one of the last war problems put up to us for solution. We built a pursuit triplane (Continued on page 114) 113 Cone ° Cabinet Model ACi2. .. $30 “The reproducer is the most vital adjunct to a radio installation” Yet nine people out of ten buy speakers with- out making any com- parisons. You will appreciate your Amplionevenmoreafter you have heard it in comparison with others. Make a test! If your dealer has no Amplion Cone in stock to give you a demonstra- tion, write to us for the address of one who has. Amplion has themostcom- plete range of radio sound reproducers on the market. Models range all the way from $12 to $135 to fit every radio set and every purse. THE AMPLION CORPO- RATION OF AMERICA 280 Madison Avenue New York The Amplion Corporation of Canada, Ltd.,Toronto,Ont. 929900009. 099O 04100910. 100 001010009010 1000000000000000100000000 9909900900011 OIOOG ( rIS} This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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114 POPULAR SCIENCE MONTHLY July, 197 ae ——e A Vision of Aviation’s Future (Continued from page 113) having an opening in the bottom of the f at the rear, through which a machine-gunner could operate his weapon while in flight inveage an enemy plane got “on his tail.” The radia: tors were placed on the sides, and the action of the wind upon them produced a sound which gave this plane the nickname of “ Whistling Billy.” “Whistling Billy” was begun only few months before the Armistice and was ng} finished in time to get to the front. ’ Doubtless there will be hundreds of yp. dreamed-of developments in flying in the next few years. In some directions we have gone further in the nineteen years since I flew the June Bug than anyone then dreamed possible; in other directions aviation has not come any- where near the visions of its pioneers, and J doubt, as I have already said, whether some of those dreams ever will be realized. Of one point, however, I feel certain. The dirigible will never dominate the field of ayig- tion, and is not comparable with the airplane, Lighter-than-air craft has proved itself tog Must Men Suffer afer 40? N AMERICAN ‘scientist has made a frequent nightly risings, chronic fatigue, depression . 7 - tions. ¢ discovery that touches the very key- and weakness are symptoms. fragile, too unwieldy, too expensive in every. E32. re way, to compete with the airplane. note of health, vigor, and welfare of men past 40. He has found a simple home treat- ment for prostate gland trouble. FREE Book This institution has published a little book, ““Why Many Men Are Old at 40” which reveals amazing facts about old age. If you suffer with prostate as | cl trouble, it may be a godsend to you. While the ‘ No Medicine edition lasts it will be matted Free els aan an Wireless Power Without medicine, surgery, violet rays or With conditions that may lead to surgery—or that : ment. $ . - ‘ take the pep, energy and joy of living out of life. (Continued from page 11) down and trick treatments, he has found a way to Mail the coupon = A lnasattonaly o ; Cushion | — agg the eg | een THE ELECTRO reflected from a mirror as a beam—the polished: ee cere econ mama | THERMALCO. oe ers ere I : 1 : is for that very purpose. us you mi the success of this treatment that an organi- = pf base hg ; expect with good reason that radio waves, zation has been established to furnish it to the millions of men who are in need of it. least the short ones that approached nearest to the character of heat waves, might be GPCSSSecceseseceseeeSeeeeeeeeeeeeeeTeseseeeeeeseseese THE ELECTRO THERMAL CO. Western Address Suive 40-P, 303 Van Nuys Bidg., Los Angeles, Calif. PTTTTIIIIII iii) laboratory he set up reflectors six feet in diam- eter, made of pitch and wax and modeled i the same parabolic or curved, somewhat cone shaped, form used in the reflectors of auto mobile headlights. [ MMEDIATELY he found he could projett a_ six-foot-wide radio beam across his laboratory. With his parabolic mirrors, Herts was able to focus radio waves up to sixty-sit centimeters—about two feet—long. This is close to the practical limit. Radio waves) | commonly used for broadcasting, often a} | quarter of a mile long, cannot be reflected ina mirror of reasonable size, for to give best re sults the wave must be considerably smaller than the mirror. But it is easy to produce short waves. In fact, a few years ago two | victims without knowing. Very often such con- ditions as sciatica, aches in back, feet and legs, t = 4071 Main St., Steubenville, Ohio. : | . aaa 4 . 2 Out of 3 Men E Remains? usd tariamusnemasteetot | Tighe ame Way: ou woulll Are you one of the 2 out of 3 men who have = Name 5 Heinrich Hertz, who discovered the existence prostate trouble at a certain age, according Add = | of radio waves, succeeded years ago in focusing to many medical authorities? Many are : City = | extremely short radio waves to a beam. Imhis . = ead the Money Making Opportuni- Make More Money ro pages 116 to 135 “ this “ion ADDING MACHINE THE VEST POCKET LAWYER ra ope cal A complete law course—clearly analyzed Guaranteed 6 years. Made of Steel, notaToy. | in understandable English. It is a daily guide—a manual of reference for the busi- ness man—the law student—the justice of the peace—the notary public—the farmer— the clergyman—the merchant—the banker —the doctor. 360 pp. _ Price $1.50, postpaid POPULAR SCIENCE MONTHLY 250 Fourth Avenue, New York City Learn Cartooning At Home—tin Your Spare Time from the school that has trained scores of today’s successful cartoon- ists who earn from $50 to $200 and more a week. The Landon Picture Chart Method of teaching makes original drawing easy to learn. Send 6c in stamps for full information and chart to test your ~ “ aut 4 SEND NO MONEY See eh oteen, Fe esti. tely. . ‘e on deliv- ery. If not eatisfied after 10 day trial money refunded. Agents wanted. BABY CALCULATOR SALES CO. P. O. Box 1118, Chicago, Ili., Dept. 16 ust name and address. radio experts, Dr. E. F. Nichols and J. D. Tear, succeeded in creating radio waves short that they lapsed into the heat-wave band. These waves were only a hundredth of! } an inch long! For radio power, then, it is readily possible : to obtain a short wave capable of being shot as 100 a straight, narrow beam from a parabolic mir Results Quick—Part or Full Time. , ‘Take Fg ts raising. It’s interesti healthful, PROFITABLE. Easy to s all you can produce at big prices. Our new course by Henry M. Lamon, former gov't ae. gives short cuts k, “How to Raise Poultry eee, Wate Se ee Eee ability. Also state age. i NATIONAL POULTRY INSTITUTE THE LANDON SCHOOL ror, as Dr. Thomas proposes. One remaiming Washington, D. C. | 1451 National Bidg.,Cleveland,O. difficulty still stands in the way—the shorter the wave, the less power can be put into it! The very construction of the vacuum tube that generates the wave makes loss of power the inevitable result of an attempt to shorten the wave length, unless some way can be found to prevent the tube from burning out under i® creased current. This is the problem that Dr Thomas faces, and that he has already gom far toward solving. Dept. 413 Travel on “Uncle Sam’s” Payroll RAILWAY POSTAL CLERKS COUPON=> P 4 FRANKLIN INSTITUTE o Dept. K-266, Rochester, N.Y. } — Sirs: Rush to me without charge: — (1) Specimen Railway Postal Clerk ss book Coaching: (2) FREE 32-page y ° ° ° @* — describing U. S. Government positions When he lit his lamps by radio before the - $1 700 to $3000 Year oe ane can na feltpartie- New York Electrical Society, he was using # MEN "30 vs s. vw any PO ions “ o ~ vacuum tube that embodied the best combine B UPO ° NAME... 2. cece ccc cecesee cesccceces tion he has yet (Continued on page 116) 9 IMMEDIATELY .¢ ¢ - Steady Work. No Layoffs. Paid Vacations. ~ RDS CeO PET Te TE Te —— SPORT © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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is to the ears. what glasses are to the eyes. Invisible, comfortable, weight- tess and harmless, Anyone can pete be. i. wt one hundred thog- sanisold. Write ite for booklet an: THE MORLEY CO., Dept. 707. Pry . : sem ‘Street, Philadelphia A LIP-Z1P SHOOTER ’ CAMPERS AND TOURISTS: Here is the very thing for you; campers tell us that this is the greatest weapon to be had where fire arms 4g are prohibited. Zip-Zip Shooter is noiseless, powerful and effective and is use zo great number of*tourists and campers, - T! this wonderful

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Wireless Power (Continued from page 114) obtained of short wave and maximum power. The radio wave that furnished the wireless current supply was only two and four-tenths meters—about eight feet—long; yet through it he was able to “broadcast”’ thirty watts, about a twentieth of a horsepower. He can produce a wave of half that length, though his power is also cut in half. To try out his scheme of reflecting a beam with a metal mirror, Dr. Thomas awaits the shorter-wave, higher-power beam he hopes to obtain. In his demonstration he allowed his radio waves to scatter at random through the surrounding air, and his feat of transmitting an appreciable amount of power was therefore the more remarkable. iy THOMAS is not the first scientist to light lamps by radio; his simplified apparatus, rather than the demonstration of wireless light, is his greatest accomplishment. Nearly four years ago, Dr. Willis R. Whitney, of the Gen- eral Electric Company, demonstrated before the American Association for the Advance- ment of Science at Cincinnati what he then characterized as an advance “as near to the wireless transmission of power as we have yet seen.” Standing a foot away from a powerful electric coil through which alternating current was pulsing at high frequency he held up a lamp bulb like those in your home and caused it to glow by wireless power. This experiment follows the same principle as Dr. Rentschler’s radio furnace, instead of Dr. Thomas’ method of using radio waves at a distance. More than twenty years before, Nikola Tesla first lit a lamp by radio. He used a wave of a size that required a huge receiving coil of wire attached to the lamp. The other end of the coil was grounded, and the length of the wire was so chosen as to be exactly “in tune” with the broadcasting station hundreds of feet away. What Dr. Thomas has done is to substitute for complicated receivers an ordinary piece of straight wire, made possible by the short wave he has produced. To pick up power from any radio wave, the rod, Dr. Thomas found, must be exactly half as long as the wave itself. Col- lecting current from a broadcasting wave would therefore require a rod of unwieldy length. With Dr. Thomas’ eight-foot wave, it need be only four feet long—a handy little rod to keep in your home! HE way that Dr. Thomas’ “half-wave receiver,’ as he calls it, picks up power from the air might be illustrated by placing a hollow tube half an “ocean wave length” long in the breakers at the seashore, pointing out to sea. One end of the tube would lie in the crest of an incoming wave, the other in the trough of the preceding one, and water would surge through it in one direction. A moment later, the crest would have reached the other end, the first end would be in a trough, and water would rush through it the other way. In the same manner an alternating surge of current runs back and forth along the metal rod from the radio waves in the air. This much science already knows about the mechanics of generating and handling the radio power beam. But there will be more to learn—for the ray that. Dr. Thomas seeks in his East Pittsburgh, Pa., laboratory, ‘is a dan- gerous subject for experiment before scientists learn to control it. No one knows what might happen if such a beam were turned loose! It might render the air through which it passed a conductor of electricity, much as does a bolt of lightning temporarily—and turn a shaft of air into an “electric wire” along which you could send an ordinary electric cur- rent. The radio beam, then, need not itself conduct the power, but (Continued on page 123)

115 A... LABORATORY... PRODUCT

With a Blade of LIGHT he slew the Greatest of all Demons~ DARKNESS Burcess BATTERY COMPANY GENERAL SALES OFFICE: CHICAGO Canadian Factories and Offices: Niagara Falls and Winnipeg

BURGESS FLASHLIGHTS & BATTERIES © This seal on a radio, tool or oil burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6.

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116 POPULAR SCIENCE MONTHLY — July, 19

Rates 30 Cents a Word. A 10% discount is Blue Prints allowed on all contracts for six consecutive inser- TO THE man who has a Home Workshes aul ni tions. : Advertisements intended for the Septem- work with tools. Popular Science Monthly offer opportunity to purchase blue prints giving deta 7” ber, 1927, issue should be received by July Sth. construction of useful articles for the home. The fol ing are a few of the blue prints available: No. 15, | op Bench, No. 17, Cedar and Mahogany e

it ervii No. 41, One-tube Radio Set, No. 42, Racio Advertising S 1ces with three stages of amplification, No. 43, Foy Radio Receiver, 44 and 45, Model Pirate Ship, 46 q ADVERTISE in 24 metropolitan dailies, 24 words, Spanish Galleon, 48, Model Sailing Yacht, No. 50, , $15.00. Helpful Guide listir 1000 publications, 4c a plane model, 51, 52 and 53, Clipper Ship, 54 and | stamps. Wade Company, Baltimore Bldg., Chicago.:..-. un i Five-tube Radio set. Send 25c for each blue prin

24 WORDS,-151 rural weeklies, $6.04. Ad-Meyer; wish to ee Science Monthly, 242 Fourth A 4112P Hartford, St. Louis, Mos “POPULAR SCIENCE” New York, N portan' Advertisers should not be by the im-

t facts on Money Making. today for the muick~ Aetion “Advertising Rate Folger" “which contains : : Boats and Launches ‘ormation of value to you. If you are anxious for quick The best evidence that it pays prot returne, do i now! Address got, inquiry to: advertisers to use the classified HUBBELL Marine Coolers convert Ford. engines anager ass vertising, ‘opular cience marine motors. ooklet free. ord sp t, Monthly. 250 Fourth Ave. New York. columns of POPULAR SCIEN CE built, blue print and directions, sixty cents. C. 6. EF FECTIVE letters and pars for honest MONTHLY is the fact that this bell, 14C Cottage St., “at oe a onn. a propositions w rown, Box Park, Arizona : arri BUILD your own boat utboard motor cee a magazine c cs the second largest runabout, cruiser, row or sail using our knoe) volume of classified advertising of materials. 55 Models. Send 25c for catalog: “Brooks MH : : . g Boat Co., Inc., Salt Street, Saginaw W.S Authors, Song Poem Writers, Manuscripts 7 magazine in the world. ead what Mr. M. E. Stephenson ‘ oe SONG Poem Writers—Send for pro sition. Ray u rtunt for Hibbel-r, D10, 2104 N. Keystone Ave, Chicag = pony cing psec = Business Opportunities er — 7 1 mon . Song Writers’ Guide.” D22-1239 Ein: Green Popul i ising 1 LEARN the collection business. Good income; — a AL opular Science— results. Interesting booklet, “Skillful Collecting, tree, “ SHORT stories, articles, etc., revised, typewritten, National Collector's Association, Science Building, New. hor —— Hursh Service, "Dept. 3, Box 1013, Harris- Gentlemen: ark, Ohio. tio urg, Pi . BECOME a Foot Correctionist. A New Profession pee, POEM. W: Writers. Monarch, 1472 Broadway, od rn ann ee ~ not medical nor chirop ay All the trade you can attend pt ew Yor b, to; many are making 0,000 yearly, easy terms 5 ; 5 x % the classified columns of ‘‘Popu- for training by mail, no further capital needed or necua Chien poe nib. »-edigeee. oe teteadane lar Science” has been a paying buy, no agency or solleiting. Address Stephenson Tae rr Cc 7 ds. B B Tform- proposition. The mumber of ory, ac ay, Boston, Mass at dimen tee Fm Pine gg ane years I have carried the adver- COPA LENTS procured; Trade Marks Registered—A tisement in your classified col- mprehensive, experienced, prompt servi ad re MANUSCRIPTS revised, typed. Quality work; low ; ‘ i 1 Salon Gad desaamans of oar tdene. rates. Satisfaction guaranteed. Try us first. Bessinger umns without interruption testi- advice gladly ean ed without charge. Bost Of in- Service, Galion, Ohio. fies to that fact. . : formation and form for disclosing idea free on request _It is the best magazine of its Richard B. Owen, 44 Owen Bldg., Washington, D. G, x kind in the field and a four square or 41-Z Park Row, New Yor Automobiles and cAccessories Proposition oie s .— SM ENIATURE die-casting chines $50.00. Byrd= Ci - « DELIVERY bodies for Ford Model T. Chassis with able, not only to the advertiser, ADVE TISE-__In 3/5 evuntry newspapers; 28 words, Inclosed cab, suitable for Contractors, Grocerymen and but to the readers as well. $10.00. Keator, Hartford Bldg., Chicag Farmers. Three styles. Price $49.50. Write Daniel Sincerely yours USED correspondence school courses sold on rte Zimmerman, Craigville, Indiana. : urchase basis. Also rented and cachane - Money- SAVE 40-80%. New and Used Automotive Parts, STEPHENSON LABORATORY, ack guarantee. , Catalog free. (Courses bought.) Le 2000 models also truck parts, 5000 bargains. Bankrupt M. E. STEPHENSON Mountain, Pisgah, Alabama. supplies, wires. —— $10 1. Particul free. Robbins Com i giandaris OE: Stator $m0.00 te Sh Sond” hess FIRST PRIZE $10.00, SP Boawebth ie. Brockign: wey, SON Comme | pecenk Motor $700.00. Ready for delivery. OX5 Motors $100.00 F. A. Schliemann, Vallejo, Calif. OPERATE money-making mail-order business ia psf up. aoe Et ee ogue. Nicholas Beazley Airplane (Rhodes Mfg. Co.) spare time. Write for free particulars, “ Triangle Mail 12 week Order Service, ue Island Ave nica SEND dime 1 for 12 inch mounted propeller and circu- SECOND PRIZE $5.00 MAKE new delicious food specialty at — is Sis ‘C Jars on free three foot model aeroplane. © selling. Leonard A. Phillips, Fairfield, Calif. everywhere. Big profits. Formula and selling oan ¢ Aero Shop, 3050 Huribut Ave., Detrolt, Mitch (Popular Science Monthly) Burand, Box 453, Tacoma, Wash. or a Flying Boats, Aircraft Motors, ena SELL: by Mail!—Books, Novelties, Bargain! a 00 H.P. Gnome Rotary motor. new, $75 THIRD PRIZE- $3.00 Pee Oe alare FREER) Ce cites se. Souk Florida. poacher helmets, $3.75. Nonsplinterable 7 ~ Dearborn, Chicago. ’ les: wide vision, $4.00; oval, $2.50. Logan Airplanes, Isabel Bushinger, Monte Vista, Colo. ear * FY West Superior, ‘Cleveland. ’ (La Salle Extension University) $50. red aby ames teeny lee ters. we —_ AEROPLANE motors. A few famous Gnome 9- ere Ot Cee. Ohiy, . whi Minder, 1€5 H.P. aeroplane engines costing Army PRIZE WINNERS who receive $1.00 - aad $3,000 s. each. Le Rhone 120 H.P., $50.00 each. each for their letters: YOU Are Now Reading " - Ff Fy — may 1eR Rhone £0 H , $50.00 each. Propellers. Aeroplanes . make you Thousands of Do _ tied you’ : on or 00 up. Hesistal goggles, $2.00 a. Send 10c for Edgar Leaverton, Columbus, Ohio '‘Eye-o ng’ po - ee We ee Ls ¢ , yual plete 12 e booklet. Marvin A. eames 730 (New York Electrical School) Formulas for aking the orld’s ggest-Selling ngton Ave., No. Minneapolis, Minn H A. Bol Rumford, Mai om = ce aA vient git hy py Making = - rman ter, or aine ce, etc. e today fo oney- Sierdirnvries ee das tot today’ gu deriving prods “ra™(Ehe Leo-fes Company} Information. Dr. Liscomb Miller, Chemist, Taps “Quick-Action Advertising Rate Folder” showing “How . F. Whiting Ignace, Mich. : Yau Gen Use Popular Seience Monthly Profitabiy.” N feng Re ay ered SIGNS and Showcards Easily painted with Lett Address your inquiry to: Manager, Classified Advertis- Patterns. Large variety of Styles and S —e Samples ing, Popular Science Monthly, 250 Fourth Ave., New Paul S. Bethscheider, West Point, Nebr. for stamp. John Rahn, B2120 Neva Ave., Chicago. York. (The Union Looms Works) BUSINESS Guide with free legal service sells every M H. Barr, Bart Fla. where. Wells cleared $1,185 in 35 days. rite for tre 2 . rs. W. pa ee ) outfit. Nichols Co., Naperville, Ill, a. Bending Machines “= i aekeen oe at P mA... —— you in bans reat pomeny g R Ah schanz, lem, Oregon en and women, opportunity to earn THE Famous Hossfeld ‘“Wrenchless” Universal (La Salle Extension University) ly operating Ragedale's original “New Ley Iron Bender is the last word in bending machines. Bends | Charles R. Kuglin, Chicago, Ill. commercial candy book free. W. Hillyer Ragsdale both Pipe and Bars to 2 i conceivable shape. | 9,E y NN... Bends Eyes, “U's”, Angles, Rings, Coils, etc. Accuratel Theo. Audel Co.) Drawer 1 ast Orange, anything fr email nail up toa 1% ° pipe cold. MAKE Much Money—Making, Selling Your Pectanthy sdjusced wit jut a wrenc - "Thoweande in use. yoods. Formulas, Processes, Trade Secrets. All = lines. Catalog Free. C. Thaxly Co., W:

write for circular *1d prices. Hossfeld Mfg. Co., oC. Winona, Minn. H. ¢c.

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n on, D. C, Byrd— , 28 words, id on re |. Money- ight.) Lee d Or Ub 3 Enright, . Cents ves. ils FREE, Receive r. ses every- sky. nly, prints a) sis.oo it! Year, d are look >, Write Us, ells every ite for ire vel $ July, 1927 Those who see the great roaring shops of Coyne forthe first time are amazed. Here arestudents from every State in the Union working on the greatest outlay of electrical apparatus everassembled in any school. .. costing hundreds of thousands of dollars ...real dynamos, huge motors, actual skeleton houses, complete power plants, transmitting sta- tions, switchboards of all kinds . . . everything from doorbells to farm power systems. Here, with A Glimpse Into the Coyne Electrical School 117 this full-size machinery in full operation every day, Coyne students get years of experience in a few months, Here with two instructors to every 25 men, Coyne students learn by actually doing. Here —and nowhere else inthe world—can you get such training! The photograph above is one of 150 viewsin our catalog, a copy of which will be mailed free upon request. See coupon below. LEARN ELECTRICITY Without Books or Lessons IN 12 WEEKS By Actual Work—in the Great Shops of Coyne i No Education or Experience Needed With a personal, gractica/ method like this, is it any wonder I can make any man into a master electrician in 12 happy weeks? OME kinds of jobs ought to be labeled with a big sign that says ‘‘Man-killer.’’ They are either so heavy, dirty and hard that they sap a man’sstrength and keep him dog-tired all the time—or else they are so disagreeable, uninter- esting and poorly paid that they kill his ambition in almost no time. And AMBITION is the most valuable thing a man can have! Fascinating Work— Real Pay! That’s why so many men are turning to ELEC- TRICITY, which offers unlimited rewards and op- sae | aga ordinary salaries of $50—$75— 100—and $150 a week! Right now big electrical jobs are actually going begging! Electrical experts with 12 weeks of training are in demand—and the need is growing every day! The situation is one that spells O-P-P-O-R-T-U-N-I-T-Y in letters a foot high for theman whois wide-awake enough toseeit! Learn Quickly Let memake you a master electrician—the Coyne way. I’ve doneit for thousands of others—farmers, factory men, and hundreds who haven’t had more than 8th grade education! I cando it for you~and start you off on the road to independence and big earnings in just 90 days! No Books or Dry Lessons The secret of Coyne-training is that it is ALL PRACTICAL work. No books—no dry lessons—n6é useless theory. In the great shops of COYNE you the “ins and outs” of Electricity by actual work on rea? electrical equipment—the finest out- lay in the country! And best of all—experts work right with you every step of the way, showing you sane electrical secrets that are essential to your COYN H. C. LEWIS, Pres., Dept. B7-73 1300-10 W. Harrison St., Chicago, Ill. $100 aWeek Jobs are commoninelectricity. Our free employment bureau puts you in touch with many openings to choose from. The following are only a few of the kind of positions = fit yourself for in the Great hops of Coyne: Farm Ligh' Ex ehting Fee #100 a Week Armature rt mat) to $100 a Week Power House Operator $50 to $75 a Week Auto Electrician $60 to $100 a Week Inventor, Unlimited Income Maintainance Engineer $60 to $100 a Week Service Station Owner $200 a Week Radio Expert, $75 to $150 a Week Contractor, $3,500 to $15,000aYear FREE R. R. Fare When You Enroll Bicht now I will allow your Railroad ‘are from any point in the U.S. to Chicago—the world’s Grea‘ Elece trical center. Send coupon for details. i ELECTRICAL I SCHOOL I ou don’t need a bit of previous experience or advanced education. Many of our most successful graduates are fellows who never went to high school and hated **book-learning.’’ The Coyne method is different/ FREE If You Act Now Make up your mind today to get into one of these real-pay electrical jobs, If you act now— I'll pay your railroad fare to Chicago and give you 2 special courses free! RADIO and AUTO-- MOTIVE ELECTRICITY! And be- sides that, I help many fellows to ) pers time jobs where they can make most of their living expenses while learning! FREE employment service for life after graduation, too. We place dozens of men in won- derful jobs every week! Send for FREE Book Just give me a chance to tell you about the unlimited opportunity that awaits you. Let me send this big book free, containing over 150 photographs and listing and telling you how you can qualify for the kind of jobs that pay $75-$200 a week. If you really want more money and a wonderful future, send for this book now! No obliga- tion. Simply mail the coupon. Mail FREE BOOK Coupon ' COYNE ELECTRICAL SCHOOL H. C. Lewis, Pres., Dept. B7-73 f 1300-10 W. Harrison St., Chicago, Ill, Dear Mr. Lewis: I want the facts, so without obligation, send me your free illus- trated catalog and details of your R. R. fare, i Nis oscakecaatussnasddasnashankcadiac ee TNE 6 sin 0001806 iniwsdsinciucieanaadedeaaadaeee j Sich sdsserdncrsesedesdvkewitcous DMG ctssscccts Bieeateee é

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118 Business Opportuni.ies MONEY MAKING OPPORTUNITIES SECTION For Boys Help Wanted CLEVER new money-making scheme you can operate anywhere by mail in spare time. A permanent income with the least expenditure of money, time and effort. Not a cheap affair but a high class mee office busi- ness paying $ 00 a week and up. Takes $10 to operate it. Particulars for addressed stam envelope or $2 for complete instructions. Metropolitan News Bureau, Box 1038, Washington, D. C. CASH in on your artistic ability. Your home, your ——, your spare time, ¥A5 A old mfne. Not a corre- 8 ence course. Sam particulars 10c. Sartco, spond Mulberry, Springfield. Ohio. INCOME Increaser— Newly enlarged 36-page monthly magazine of best, latest ideas, plans, schemes, tips. inters, starters. One year, $1.00. Three months, 25c. fncome f Increaser, 63S Court, Boston, Mass. INTERESTED in Science? Form -Seience Club in your town. Conduct experiments, field trips, ete. In- struction booklet, club plans, membership blanks, sample magazine, 25c coin. Scientific Clubs America, McComb, Mississippi. For Inventors UNPATENTED Ideas Can be Sold. I tell you how and help you make the sale. Free particulars (Copy- righted). Write W. T. Greene, 805 Jenifer Building, Washington, D. C. INVENTIONS _Commercialized. Patented or un- tented. Write Adam Fisher Mig. Co., 183 Enright, St. Capital Raising CAPITAL Raising Campaigns Prepared. Commission Basis. Morris Advertising Agency, 3608 Warren St., Philadelphia. Auis, Mo. INVENTORS: Get this pamphlet—**What to In- vent.” No theory or guess work, but things actually asked for by manufacturers. Sent prepaid for only $1.00. Inventors’ Syndicate, 23 Paladium Bldg., St. Louis, Mo. I AM in touch with hundreds of moneyed men and manufacturers who wish to buy good inventions. Hart- ley, 38 Court S6.. Bangor, Maine. Chalk Talks LAUGH producing program, $1.00. Cartoonist Balda, Oshkosh, Wisconsin. Catalog free. Chemists OUR new catalog listing 5000 chemicals, 2500 illus- trations, Laboratory apparatus and 1000 books. Sent on receipt of . Radio catalog (100 pages) liberal discounts, 10c. Laboratory Materials Company, 641 East 71st Street, Chicago, U. 8. A. INVENTORS’ Universal Educator—contains 900 mechanical movements; 50 perpetual motions. Tells how to obtain and sell patents. Suggests new ideas. Explains how to select your attorney and avoid patent sharks. Special Price, $1.00 postpaid. Albert E. Dieter- ich, 681 Ouray Bldg., Washington, D. C. GET your own patents. Forms tions, $1. Cooperson, Campbell, C: alif. INVENTORS assisted financially to secure patents. Write for particulars. Equitable Investment Com- pany, Box 1648, Washington, D. C. complete instruc- For Men and Women MAKE iortunes as Real Estate Specialists, | $100,000. Cooperate with me. Learn the secret success. Use my remarkable system. Start at nf spare time. Build wonderful business without or experience. Write at once lor my amazing Tone. making offer Same Ostrander, Room 34, 18 Fag, 18 St., New Yo WAN’ TED— Wepresatatives in every factory ing United States. Fopular Science Monthly, 259 foun Ave., New York. MEN wanting Forest Ranger or U. S. Mail position $125-$225 monthly; steady, interesting work. Fartiey. lars free. Write Y. Bradford, 31 South 52nd St., Fhily. delphia, Pa. HOW to obtain — in South \merica, $m Box 342, South Bend, C%, $1.00 ARE you old at ons ? See our advertisement page 133 of this issue. The Electro Thermal Come Company, 4071 Main Street, Steubenville, Ohio. —_—_——= Help Wanted Instruction FIREMEN, Brakemen, Baggagemen (white or ored), slee ping car, train porters (colore'), $1 monthly. E: xperience unnecessary. 838 Railway East St. Louis, Ill. DETECTIVES Earn Big Money. Excellent tunity. Travel. Fascinating work. ix periense x a Write, George Wagner, 2190-P 18 $1140 to $3000 year. Steady, pleasant work. a tion. Short hours. Experience unneceasary. education. List a. and sample ——— aig particulars—Free te today sure. tute, Dept. L30, Rochester, N. Y. 8S. GOVERNMENT jobs. Men—women, 18 w SSeaOrive names poe Jt, scam. Experience es : ~ unnecessary. Particulars free. rite, George Wagner, , Dogs, Birds, Fish Peeeeery artioule Incorporations WANTED—Representatives in every factory in the United States. Popular Science Monthly, 250 Four th DELAWARE Incorporator, Charters: Fees Smali BEAUTIFUL registered bull pups, $15. Bulldogs, 501 Rockwood, Dallas, Texas. Ave., New York. Education and Instruction DON’T prepare for any Civil Service examination without seeing our free catalogue. Columbian Corre- spondence College, Washington, D. C. HOME Study Courses. All Schools, Lowest Prices. Terms. Cotanes Free. Mention subject. Fred Goetz, 440-B Sansome, San Francisco. **4,001,001,001,001 BRIEF numerals.’ One dollar for the system with its interesting ll until Nov. 1927. Enclose self addressed stamped envelope for samples or reply. Address Hyrum Alpha Thomas, Box 69, Glenw , Iowa. CARTOONING and Commercial Art. 25 lessons, 300 Illustrations, 2 clothbound volumes and drawing outfit $5 postpaid. Catalog Free. Nu-Way Art School, 220 Graham Ave., Brooklyn, N. Y. hong Study Courses by all schools on all sub- — s, sold complete in fine condition, at bargain prices, use slightly used. Sensational’ reductions on all standard drafting, engineering, automobile, radio, chemistry, electrical courses. Money Back Guarantee. Easy Terms. Courses bought. Write for Ay catalog. Economy Educator Service (Dept. N), 202 W 49th St., New York. LEARN simplified bookkeeping and Pitman light- line shorthand, 50c; squaring circle interest problems. Will Marr, 605, Nashville, Tenn. DETECTIVE’S Ring—Watch Others U oe Sterling silver with special mirror. Patented. “Lik eyes in back of your head."’ Send $3.00 and strip a paper showing finger size. Guaranteed. Ren Mfg. Co., Desk 62, Winchester, Mass. Formulas Manufacturing a ‘‘Famous New 4 in 1 Formula $1.00, BIG Profits! Beauty Cream.” Sell by agents or mail. Earl P. O., Box 235, Lorain, Ohio. DON’T Buy Formulas till you’ve read my Valuable, “Eye-Opening” Literature for Guaranteed Money-Making Specialties in all lines. Mailed Free. Address Miller, Manufacturer's Chemist, Tampa, Florida. + MAKE Much Money—Making, Selling Your — Goods. Formulas, eee Trade Secrets. All k ee Cc ‘atalog Free. . Thaxly Co., ncnhnesen » C. For Sale FOR Sale: Patent for United States and foreign countries, Improved Flour Sifter; Outright or Royalty Basis. Harry Nakagawa, Tanana, Alaska. SWIFTHAND, the New Writing System, revolution- izes handwriting, combining shorthand speed with the a and legibility of print. New principle elimi- nates guesswork despite speed. No abbreviations need be memorized. Scientifically based on the alphabet but even easier to learn. Uses only longhand strokes. Particulars FREE. Economy Educator Service (Dept. N), 202 W. 49th St., New York. _HOME study: High School, courses. beeen free. Normal, Business, and Apply, Carnegie in Ten Lessons. Shelby course LEARN Bookkee} plete. Makes is brief, concise, com kkeeping easily understood. Price $5. Write for particulars. Shelby lublishing Co., 605 Cotton Exchange Bldg., Memphis, Tenn. LaSALLE Traffic Course, 40 books, like new, sacrifice $20.00. LaSalle American Law and Procedure, 14 vols., $20.00. —— Sieber Accountancy, 5 new volumes, $10.00. a will be quickly taken. Rush bar 3 order. We will ship on receipt of ‘A down, balance . D. Business Builders, Athens, N. Y. "BOGBLE entry ‘bookkeeping mastered in 60 hours with 8 keys; guaranteed; diploma.” International Book- keeping Institute, Desk 10, Springfield, Mo. CARTOONING—Complete course. Unusually low rice. Particulars on request. Carlson Cartoon Service, Jept. S, 116 West 39th Street, New York. Electrical THE Electriciun’s Wiring Manual, By F. E. Seng¢- stock, E. E. Contains all the information needed for the yroper installation of lighting and power systems in ouses and other buildings. it a and covers inside electrical wi and construction accordance with the National Electric Code. Pocket size—flexible bind- pp. Price $2.50. Popular Science Monthly, } Fourth Ave., New York City. Farm Wanted WANTED—Hear from owner good farm for sale. Cash price, particulars. D. F. oa FY Minn. Financing and Investments ASSU. ny vert in the Stock Market. How this is best ob how you can trade in 100 shares of stock lor mgi50 t to $225 is capatnet in our free Booklet. Paul Kaye, 149 Broadway, New York. For the Home HOT water on tap, $6. Make your own Automatic. Write John Kirkeby, San Luis Obispo, Calif. GRANDFATHER clock works $5.00. Build your own case, instructions free; make good profits selling your friends. Clock works with chimes bg old or new cases. Write for full particulars. Clock Co.. Nicetown, Penn. TO THE man who likes to work with tools, Popular Science Monthly offers the opportunity to purchase blue- prints giving details of the construction of useful articies for the home. The following are a few of the blueprints es No. 1, Sewing Table, No. 5, Kitchen Cabinet, No. 13, Tea Wagon, No. 15, Workshop Bench, No. 17, Cedar ‘and Mahogany of est, No. 43, Four Tube Radio Receiver, 44 and 45, Model Pirate Ship, 46 and 47, Spanish Galleon, 48, Model Salling Yacht. Send 25c for each blueprint that you wish to + =A Science Monthly, 242 Fourth Avenue, New York, N. CEDAR chests only $11. 5" Rede “Gamnalete with rich copper trim—you assemble and save half— send for pictures. ‘‘Red-i-Kut’’ Kuempel, Guttenberg, forms. Chas. G. Guyer, 901 Orange St., Witmingae Delaware. Inlays EXPERT inlays; send stamp for samples, literatun Robert Herrick; Newark, New York. $$$ Insects Wanted WHY Not spend Spring, Summer, Fall ga butterflies, insects? I buy hundreds of kinds f for lections. Some worth $1 to $7. Simple outdoor wok with my instructions, illustrations, price-list. Send im for Illustrated P geapectue. Sinelair, Dealer in Insects, Dept. 7, Box 1424, San Diego, Calif. Inventions Wanted INVENTIONS commercialized. Patented or m patented. Write Adam Fisher Mfg. Co., 183 Enright, St. Louis, Mo. WILL buy approved invention. Write W. L. Kendig 416 N. Duke Street, Lancaster, Pa. Laboratory and Chemical Services YOUR che:nical problem solved and working form or process furnished for $5.00. Write me. W. § Richards, Industrial Chemist, Box 2402, Boston, Mas EXPERIMENTERS. 20 C.P. Quality Chemica for $1.00. Chem. Laboratories, 900 Belmont, Chica, Literary THREE essays: ‘“The Flowers of Democracy .” “For ‘Sports’ Cnly, ” ‘“‘The Powers That Be,” and oq “Beycnd Marriage.’’ All for cne dollar. Sohn val, Box 294, South Bend, Indiana. Machines _ CONCRETE Building Block Machines and Moll Catalog free. Concrete Manufacturing Co., 5 N. Mali Iowa. St. Louis, Mo. Help Wanted Magic Tricks EARN $25 weekly, spare time, writing for news- — . . ‘ : 7 MAGICS — Tricks — Puzzles. Catalogue Fre apers, magazines. Experience unnecessary. Details Schembri Company, Box 1124, Detroit, Michigan. ree. Press Syndicate, 971, St. Louis, Mo. STEAMSHIP positions—Europe. Orient. Good pay. Experience unnecessary. List of positions free. Box 122-Z. Mount Vernon, N. Y. SILVERING Mirrors, French plate, easily learned; immense profits. Plans fr Wear Mirror Works, Excelsior Springs, Mo. MEN wanting forest ranger job: $125-$200 month, nice cabin. Hunt, trap and patrol. Write for list National forests. "Rayson, Dept. B-23, Denver, Colo. NEW 1927 “‘Fun-Magic-Mystery” now ready. 1 pages, profusely illustrated. Over 750 tricks—i —jokes—puzzles—books—European novelties at ® duced prices. Postpaid, 10c. "ha e Douglas, Station A4 Dallas, Te:.as. ——— Mailing Lists MEN, get Forest Ranger job: $125-$200 mo. and home furnished; permanent; hunt, fish, trap. For details, write Norton, 224 McMann Bide., Denver, Colo. IF YOU Are A Man Worthy of the name and not afraid to work I'll bet you. $50.00 you can’t work for us thirty days and earn less than $200.00. Think I’m bluffing? Then answer this ad and show me up. Open- ings for managers. Wonder Box sells on sight. The best selling proposition in America today. Write Tom Walk- er, Dept. 111, Pittsburgh, Pa. SECRET Service B e, credentials and year's membership $2. Money back if not satisfied. Con- tinental Secret Service System, Box 81K, Waukegan, Ill. 99% GUARANTEED Mailing Lists. Agents, But ness Firms, Individuals, Professions, for every Guaranteed reliable and accurately compiled. —_ and price list on a National Mailing List 845 Broad St., Newark, N. J. Manufacturing WIRE: Steel, Aluminum Copper and Brass. Witt goods manufactured to order. Cooley Manufacturilg Co., 528 N. Western Ave., Chicago, Illinois. D! Salarie fered plans machi knowl wedge motive Mechz man is fine sa tion tc Drafti: like th good-n room. Fir We h: time me¢ with onl and easi off doing done in | fices. We specify. by notec ployers « ing lesso learn at TI Coupe and emp this inst: ink and sional qi in your j

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‘all gat cinds ry yutdoor work ist. Send i er in Insects, (ee $$$ nted or m 183 Enright, Vv. L. Kendig, rvices ‘king formih W. Stedma soston, Mass. y Chemicals mnt, Chieage le “~ ; J obs Veiby, Ities at Te Station A4, ne ——e \gents, Bus every neti d. Catalogu ing List ©, a ——————— Brass. Wir anufact GO INTO DRAFTING! EERE! eRe: Salaam XPERT Draftsmen are urgently E needed in all building, manu- facturing and engineering lines. Salaries of $60 to $125 a week are of- fered to men who can draw original plans, who can calculate and design machinery, buildings and products. A knowledge of Drafting is the entering wedge to success in the Electrical, Auto- motive, Structural, Architectural and all Mechanical industries. A good Drafts- man is always sure of employment at a fine salary, and he’s in line for promo- tion to still better, executive positions. Drafting is fascinating work, and you'll like the fine bunch of fellows and the good-natured atmosphere of the Drafting room. First~We Train You We have developed a simplified, one-step-at-a- time method for teaching Drafting. Any man with only common schooling can learn, quickly and easily, at home in spare time. We start you off doing actual Drafting room jobs, the way it’s done in the big Architectural and Engineering of- fices. We give you the kind of training employers specify. In fact our instruction has been prepared by noted Engineers who are themselves big em- ployers of Draftsmen. Mail coupon for 3 Draft- ing lessons, actually free, to prove that you can learn at home, in your spare time. Then We Help You Get PLACED! Coupon also brings amazing combination training and employment service offer, which says, unless this instruction leads directly to a better job and increased salary, it will not cost you a penny. Outfit GIVEN! We include without ex- tra charge, as a part of this training, imported in- struments, board, T- ; square, triangles, paper, ink and supplies. These are full size and _profes- sional quality—the kind you will keep and use in your job after you finish. MONEY MAKING OPPORTUNITIES SECTION EVERY JUNE fiw They Say ‘‘Go \W Back Half a Mil- lion Places, to the End of the Line!” You men who are earning less than $40 a week, who have neither school education nor specialized training—have you noticed how hard it’s getting to find, or spit a good job? Have ou watched the spread of UNEMPLOY ENT, and do you cae that it’s your class which are first to be fired when the high pitch of prosperity lets down a bit? Do you realize that BIG CHANGES have taken place in all business and industry in the past five years, and that unless you learn to know and face these dangers, you’re SUNK? The American School presents these facts in a friendly spirit, to help you realize how O. C. MILLER O. C. Miller, Director Extension Work School} these NEW CONDITIONS strike at your very existence. Each Year Worse “Luck”’ Ten years ago men could “get by” with neither schooling nor training. Then it was still possible to learn by “practical experi- ence” alone. Today, there are MILLIONS of high school and college graduates to compete with you for jobs and advancement. Each June half a million more come into the battle field armed with DIPLOMAS. They are elbowing uneducated, untrained men out of the way. They are pushing into the facto- ries and offices and drafting rooms. What chance have YOU to win against this “ June” army of better educated men? There’s One Way Out! Now you see the danger which you must face sooner or later. What are you going to do about it? You can’t quit your job and go away to school, but the school can come to you. You can get SPECIALIZED TRAINING, right in your own home, in spare time, the best sort of education for your needs, better for your purposes than general school subjects, the kind of equipment which employers are seeking these days of highly-organized industry. We have equipped 250,000 men to meet the new dangers, we have prepared them for better jobs and bigger pay. We have placed many in fine positioris. You have only to follow their example. You can afford the cost and the terms. And you take no risk. We take all the risk that you will succeed. You must master the training, you must be placed in a well-paid position, or the service will not cost you a penny. LAST CALL! What are you going to do about it? You must face the new dangers RIGHT NOW. You dare not put off decision. It will be much harder to meet the enemy WHEN HE IS UPON YOU. You won’t find it as convenient to start, after you're out of a job, as today. Snap into it, then. Mail the coupon. Get all the facts about the new conditions in our booklet “The June Terror.” Look into the opportunities open to you when you're an expert Draftsman. Find out how easily you can learn, at home. Get our guarantee to train you and help you get placed. DO IT NOW! DRAFTING Lessons FREE! O. C. MILLER, Director Extension Work, American School, Dept. DB-75, Drexel Av. & 58th St., Chicago. (C Please send free booklet ‘“The June Terror.” 3 C—O Please send 3 Free Drafting lessons to prove I can learn at home, in spare time.

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120 Miscellaneous MONEY MAKING OPPORTUNITIES SECTION Patent Attorneys

FORMS to cast Lead Soldiers, Indians, Marines, Trap- oe, Ane, 151 kinds. Send 10c for IHustrated Cata- rue. Henry C . Schiercke, 1034 72nd St., Brooklyn, N.Y. ADVERTISER: Ask today for a copy of: the “Quick-Aetion Advertising Rate Folder.” It contains some important facts which will prove yy

and valua ~A to you. It also tells ‘“‘How You Can Use Popular Science Monthly Profitably.”’ Le =| d like to know, re t you? Address your inquiry to: Manager, Classified Advertising, Popular Science ‘Monthly, 50 Fourth ye New York. CASH Paid for dental gold, false teeth, discarded jewelry, diamonds, pas. Mail to Robert Uhler, 425 Sterling St., Brooklyn, N. Y. Models and Model Supplies

SHIP Model Fittings: Send ria ys pe list. A. J. Fisher, 1002 Etowah Ave., Royal Oak, Mich SPECIAL pepeianery or parts, Dies, Tools. Metal Specialties, Model special gears, stock gears and Model Supplies. end 5c for Catalogue. The Pierce Model Works, Tinley Park, Ill. WORKING models built. Drawings prepared free. Let our designing and engineering departments and 27 years cnperience assist you with your invention. Lowest acess. ohmeier Mfg. Co., 1385 E.-17th St., Cleveland, 0. WOODS for Models, Scroll Work and inlaying. Fred Wild, 510 East 11th St., New York. SHIP Model Fittings and readycut hulls. Send aa for list. Roy Hancock, 323 Douglas, Portsmouth,

AIRPLANE models, build and fly them. Our large cokshanes illustrating 31 finest meee, complete line of supplies sent pompase for 10 cents. 8. pie Air- craft Corp., 341-P-Monroe St., ake N. Y. SPECIAL machine builders, tool and die makers, inventor’s models, production work of all kinds. Dept. J. uality Hardware & Machine Co., Ravenswood and orndale Avenues, Chicago, Ill. SHIP Models! a, I parts and blueprints for Three Masted Chinese Junk, 60c postpaid. Casson- Craft, Framingham, Mass. MODEL steam engines and boilers. Boat and boiler fittings. Les 10c stamp for catalog. Refunded with first o odel Machine Shop. 212 Price St., Rah- way, New. a, :

Motion Picture Business

MOVIE film Ic ft. 150 ft. $1. Reels $2.75 up. Stam brings — 7. — list. X. Sales Company, Box Al5 New Haven, C

Motorcycles Used, rebuilt. Catalog free.

Guaran- MOTORCYCLE bargains. Floyd teed. Shipped on approval. Clymer, 812 Broadway, Denver, INDIAN motorcycles $50. Bai models—$10 deposit with oe. — O.D. Stern Bros., 1790 Ist Ave., N. Y. C

PATENTS, Trade-Marks, all countries. Ten years experience examining Fo ny eee in Patent Office. Consultation invited. George Beeler, Patent Attorney, 11 Park Place, New York. ¥ July, 197

Rabbits MAKE big profits with Chinchilla Rabbits, Rag P Money Makers. Write for facts. Conrad’s. Ranch. Denver, Colo.

MONROE E. MILLER, Ouray Bldg., Washington, D. C., Patent Lawyer, Mechanical, Electrical Expert. Book- let and Priority Record blank ‘gratis. PATENTS Procured: Trade Marks Registered.—A comprehensive, experienced, premes service for the pro- tection and development of your ideas. Preliminary advice gladly furnis ed without charge. Booklet of in- formation and form for disclosing idea free on request. Richard B. Owen, 44 Owen Bldg., Washington, D. C., or 41-Z Park Row, New York. RICHARD E. BABCOCK, Patent Lawyer, Washington Loan & Trust Bldg., Washington, D. C. ’ Booklet PATENT, trade-marks, copyrights. Reliable services by an experienced practitioner devoting personal at- tention to each case. Inquiries invited. References furnished. B. P. Fishburne, Patent Lawyer. 525-C McGill Building, Washington, D. C. LANCASTER AND ALLWINE, 232 oa Building, Washington, D. C. “Originators of the Form Evidence of Conception.’”’ Before disclosing your invention to anyone send for blank form to be signed and witnessed. Form and patent information bulletin free.

CARL MILLER, en agg Patent Attorney. ar vill Building, Washington, D . C. Write for Instruc- ons.

EDWARD C. SASNETT, Formerly a <a = iner U. S. Patent Office, “Attorney-at-Law. Strict pergenal service. Correspondence invited. 516 Nrecuit uilding, Washington, D. MR. ADVERTISER: ak today for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting It_ also tells ‘“‘How You Can Use Popular Science Monthly Profitably.”’ Ry d like to know, wouldn’t you? Address your inquiry to: Man- ager, "Classified Advertising, Popular Selence Monthly, 250 Fourth Avenue, New York. IMPORTANT to advertisers! Are you deriving profit from your advertising? Write today for a copy of the “Quick-Action Advertising Rate Folder’ showing ‘““How You Can Use Popular ae Monthly PROFITABLY.” Address your inquiry to: Manager, Classified Advertis- ve. F ‘opular Science Monthly, 250 Fourth Ave., New

and valuable to you.

INVENTOR’S Advisor, valuable free. Lebiner, Three Parkrow, New PATENTS. As one of the oldest patent firms in America we give inventors, at lowest consistent charge, a service noted for results, evidenced by many well- known Patents of extraordinary value. Book, Patent- Sense, free. cey & Lacey, 648 F. St., Wash., D. C. Estab. 1869. — book, sent

il Real Estate—Orchards—Farm Lands PECAN—Orange—Fig Groves “On the Gur Monthly payments. Guaranteed care. Big, returns. Suburban Orchards, Dept. **S,’’ Biloxi, LAND free if planted to bananas. Bananas crop the second year. -$5.00 monthly will plant fl which should pay $1,500 profit annually. Companies will cultivate and market your —_ ° ananas ripen every day and you get your rh every 90 days. For particulars address Fantha Plante. tion Co., Empire Building, Block 744, Pittsburgh, Pg.

ous

ies

| Salesmen and Agents Wanted

AGENTS—Clever invention! meng - ap mak pen a fountain pen. Fast office seller, big profit, increasing everywhere. [Exclusive territory offers Sample free. H. Marui Company, Tribune Bldg. » NewYork GET our free sample case, toilet articles, perfumesay speciaities. Wonderfully profitable. La Derma | Dept. F., St. Louis, Missouri. AGENTS. $60—$200 a week. Genuine gold letter letters for store windows easily applied. Free samples. offer to general agents. Metallic Letter Co., 434-4. ¥ Clark, Chicago. BANKRUPT and Rummage Sales. Make daily. We start you, furnishing everything. Distributoy Dept. 34, 609 Division, Chicago. $10 DAILY silvering mirrors, plating and refi lamps, reflectors, autos, beds, chandeliers by new m Outfits. furnished. Write’ Gunmetal Co., Ave. {F, Decatur, Illinois. AGENTS—Best seller; Jem Rubber Repair for ting and tubes; supersedes vulcanization at a saving of ove 800 per cent; put it on cold, it vulcanizes itself in ty sainunes, and is guaranteed to last the life of the by tube; sells to every auto owner and accessory d particulars how to make big money and free sam dress Amazon Rubber Co., 504 Amazon Building, delphia, Pennsylvania. BIG money and fast sales. Every owner buys initials for his auto. You charge $1.50; make $1.3 Ten orders daily easy. Write for a? 2

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Patents for Sale

INVENTORS: Use our special service for presenting your invention or tent to manufacturers. Adam Fisher Mfg. Co., 183-A Enright, St. Louis, Mo. samples. American Monogram Co., Orange, New Jersey. A BUSINESS of your own—Making Sparkling Glag Name and Number Plates, Checkerboards, Signs. Big Book and Sample free. EK. Palmer, 513, Wooster, Ohio, AGENTS—Make a dollar an hour. Sell Me patent patch for Sestanthy mending leaks in all u Sample package free. Collette Mfg. Co., Dept. 4j, Amsterdam, N. Y.

TO MANUFACTURERS—Sale or Royalty. Patent No. 1,607,933. Whitney Book Trolly, adjustable table. A. Whitney, Big Timber, Mont. PATENTS listed for sale. Equitable Investment Company, Box 1648, Washington, D. C.

Motors

MOTORS—New GE 110 or 220 —_ by A yee ee Phase, % HP $11.90, 4% HP , 53 fail $3 Check or Money Order. We wil enip vat O.D. — where. Motor Specialties Co., Crafton, Penna.

Photographs and Supplies

HAVE you acamera? Write for free sample of our big magazine, showing how to make better pictures and earn money. American Photography, 117 Camera House, Boston, 17, Massachusetts.

Music and Musical Instruments

SAXOPHONISTS — Clarinetists — Cornetists — Trombonists—get “‘Free Pointers.” Virtuoso Music School, 36, Buffalo, ; A VIOLINS—Fine handmade. 935 14th, San Pedro, Cal. Office Devices ADDRESSING machines, multigraph, duplicators, folders, check writers, sealers dictating machines, at about half new cost. Pruitt, 117 N. Market 8t., C hicago. ALL ADVERTISERS ene not be without the im- Rortant facts on Money ng. Write today for the ick-Action Advertising Rate Folder’ which contains ‘ormation of value to you. If you are anxious for quick rofit returns, do it now! Address your inquiry to:

Low prices. J. Lehto,

er, Classified ee Popular Science Monthly, 250 Fourth Ave., New York. Patent Attorneys PATENTS—tTime counts in "ideas. for patents. Don’t risk delay in protecting your ideas. Send sketch or model for instructions or write for FR ik, “How to Obtain a Patent” and “Record of ievension™™ form. No

MAKE money in Photography. Learn quickly at home. Spare or = = New Plan. Nothing like it. Experience unnece American School of Photog- rapliy, Dept. 1743, 3001 “Michigan Avenue, Chicago.

Photoplays Wanted EARN $10 daily silvering mirrors, fisting and mm finishing metal ware, headlights, chandeliers, bedsteads Outfits furnished. F. Decie Laboratories, 1133 Broat way, New York. POLMET Polishing — cs all metal. Selly fast at 25c. Sample free. F. C. Gale, 15 Edinbon St., Boston. ANY salesman can sell them! Merchants everywher use punchboards. Someone sells them, why not you Collect big commissions daily. Newest, largest elaborate catalog sent upon request. Lincoln Sales Co., 9 8. Clik ton, Chicago, Dept. G. AGENTS: Make $500.00 Monthly. Pay daily. Nom vestment. Rhinestone initial buckles and novelties. Sd easy everywhere. Exclusive territory. Chaton Noveliy Co., 606 Blue Island. Chicago. DON’T sell for others. Employ agents yoursell Make your own products. Toilet articles, hou specialties, etc. 500% profit. We furnish everyt and show you how. Valuable booklet free. Write once. ne Scientific Laboratories, 1976 W. Broad, Richmond, Va

$8$1250 FOR a Photoplay Story by an unknown writer and sold through our Sales Dept. We revise, copyright and market. Located in the heart of Motion Picture Industry, we know the demand. Estab. 1917. Send Mss. for free criticism. Booklet on request. Universal Scenario Compens. 214 Western & Santa Monica Bldg., Hollywood, Calif.

Pipe and Boiler Tubes PIPE second hand, guaranteed suitable for all prac- tical purposes with new threads and couplings, sixteen feet and over; cut to your requirements, also Boiler Tubes. New Fittings. Pfaff & Kendall, 100 Waydell St., Newark, N. J. e

Printing and Engraving

BETTER Printing for Less Money. Write us about your printing needs, and you will save money. Ernest Fantus Company, 525 South Dearborn Street, Chicago.

charge for information on how to pr = ye confidential. Prompt, careful, efficient larence é O’Brien, Registered Patent ‘Attorney, Security Bank Building arecnty across street from Patent Office), Washington, D. C. (See page 125) PATENTS. Booklet free. Highest references. Best results. romptness assured. Watson E. Coleman, Patent Lawyer, 724 9th Street, Washington, D. C. INVENTORS’ Guide free on request; gives valuable information and advice for all who have original ideas or improvements. Frank Lederman, Registered Attorney Engineer, Woolworth Bldg., 1714, New York. UNPATENTED Ideas Can Be Sold. I tell you how and help you make the sale. Free particulars (Copy- fipnted). Write W. T. Greene, 811 Jenifer Building, ashington, D. C. “MILLIONS spent annually for Ideas! Hundreds now wanted! pesent yours and profit! Write today for free book—tells how to protect yourself, how to invent, ideas wanted! How we help you sell, ete. American indus- tries, Inc., 501 Victor Bldg., Washington, D.C.

SUPERIOR quality printing. Attractive samples free. Kay Press, 5406 Thurston, Rochester, N. Y. LET us bid on your printing order. First class work. Lowest prices. Crane Printing Co., 1111 East 33rd, Kansas City, Mo. portan' ADVERTISERS should not be without the im- ant facts on Money Making. Write today for the ,, PGuiek-Aetion Advertising Rate Folder” which contains information of value to you. If you are anxious for quick rofit returns, do it now! Address your inquiry to: anager, Classified Advertising, Popular Science Monthly, 250 Fourth Ave., New York. 250 LETTERHEADS, 250 Envelopes—Bond, $3.00. Arrow Press, Kankakee, Ill. “NEARGRAYV UREMBOSO" tionery— ditterent—exquisite—Sampies. Knox, Indiana. a THOUSAND Hammermill Bond letterheads four dollars; Multigraphing. two. Miscellaneous printing. Mayray, Monmouth, Illinois. :

mbossed Sta- Sollidays,

AGENTS, both sexes, we manufacture and contml new household article. Fast seller. Big profits. Ex rag \ ee Write now, Connolly, 123 Liberty AGENTS, Salesmen, Crewmen—You'll have tht Devil’s own time finding a better seller than “Zippo” Splendid profit on snappy 50c **Go-Getter” repeat that sells on a ten-second demonstration. Works whik you watch it. Demonstrates value while others wast time making claims. New development. G scientific triumph of the age. It’s the berries. Write immediately for comnlete proposition. Kara Company, 907 Bozan Street, Fort Wayne, Indiana. AMAZING Gas Saver. Every Auto. 1 free to intr duce. Vapor moisture. Doubles Mileage. Critchlow, E-142, Wheaton, III. $75 WEEKLY. Man or woman wanted with — and industry, to distribute Rawleigh’s How Products to steady users. Fine openings near you. train and help you so you can make up to $100 a week@® more. No experience necessary. Pleasant, profi dignified work. Write to-day. W. T. Rawleigh Cy Dept. NY9953, Freeport, Ill. FREE: Large wholesale specialty catalog, showii best sellers from all parts of the world. Sporjs ©, Lesueur Center, Minn. NEW Camera. Regular black and white phote finished quickly inside camera. Make money selling cameras, taking photos or doing both. Crown Compal, Dept. 485, Norwalk, Conn. $50.00 WEEKLY easy, Applying ry Initials @ on Automobiles. No experience n ed, $1.4 5 profit, $1.50 job. Free samples. ‘‘Ralco Monograms,” Washington, Boston, Mass. 35% COMMISSION selling $1.50 boxes Mon Genteenety. New. Write. Wolfeprint, Lawndale, elphia CALIFORNIA perfumed beads selling like hot cakes Agents coining mone: a. profits. Catalog fret Mission Kactory, R2328 W. Pico, Los Angeles, Calll SIMPLEX Vaporizer. 25 to 60% increased mileat® guaranteed. Retails $1. Thirty days free trial. Er clusive territory. American Fixture Co., 232 West Water, Milwaukee, Wis.

July;

Page 139

July, 199 —_ abbit 360 Coneat li | Lands — the Gui» Big, Biloxi, Mie ——_—_ d refi new me! 0., Ave.< —_——_—_. air for tires ving of over itself in two of the tire or y dealer. P sam ad. ilding, er buys make $1.35 ars and fre yt. 47, Eas irkling Glas , Signs. Big pster, Ohie,

be ny not est elaborate o., 9 8. laily. Noi® velties. Sel ‘ton Novelty ts yoursell, 3, householl and contrd profits. Ex 123 Liberty 1 have the an ‘*Zippo.” epeat articke Works whik thers waste Greatest ries. Write aram-Smith Indiana. ———— ree to intr Critchlow, ith ambition Household ar you. We OO a weekor , profi wleigh Ca, og, showing Sporjs ©, — hite photo oney selling n Company, Initials @ profit rams,”

Mon ndale, ___ a e a = atalog geles, Calf

Juty, 1927 Salesmen and Agents Wanted

———————_ wanted to resilver mirrors at home. Im- YOU monte plating autoparts, tableware, etc., write for information. Sprinkle, Plater, 96, Marion, Indiana. er TY Y (In Advance) introducing latest guar- $15.00 Dey a men—women—children. Just write ont rs. We deliver and collect. Capital—experience ordécessary. Samples furnjshed. Milton Mathews, wad 1527, Cincinnati, Ohio. err aay, G Sells Like Shoes. Every perscn « prospect. tng pes for Mason Shoes direct from factory. 85 ns styles. Amazingly low prices. No experience stun” FREE outfit. Mason Shoe Mfg. Co., Dept. 14, Chippewa Falls, Wis. R Agent let me tell you how to make the ours Pigeest-selling Specialties as, Sealatite, punc- ture-proofing liquid for tires; Solvit Hand Cleaner; Mendit, Fabric Patching Liquid; Cellu-lac Automobile sh—-all colors; Bugacide, Fly-killing Spray; Non- Thermic Ice Saving Cloth; Tufnit, for qu rupling life Silk Hosiery; Ducopol Guaranteed Most Efficient Automobile Polish. Fifty other equally Big Money- Makers. Investment Small. Profits Great! Let me teil ou how to get the profit you’re entitled to. Miller, rdustrial Chemist, Miller Chemical Building, Tampa, Florida. AGENTS: Build a permanently profitable business on one easily sold item. Globe Re-Atomizers, a new, patented invention has an untouched, ten-mullion dollar market awaiting it. Act now and obtain exclusive repre- sentation. Send $1.00 for sample and complete informa- tion. References: Chamber of Commerce, R. G. Dun, National City Bank, Brotherhood Bank, Globe Sales & Distributing Co., 101A Spokane St., Seattle, Wash. AGENTS Wanted. $2.00 an hour for special advertis- ing work among local families. Exceptional oppor- tunity; pay starts immediately. American Products Co., 9216 Monmouth, Cincinnati, Ohio. GREAT neckwear line now free! Features finest quality neckwear at factory prices. Collect big com- missions daily. Write for FREE tie offer and FREE outfit. Nawco Neckwear, desk 7-V, Covington, Ky. AT LAST! Reasonable priced Auto Emblems for every Lodge. Sells ior only $1.25. Write for attractive selli position and FREE sample case offer. North Centr Bistributors, Department 10, Ashland, Ohio. A PAYING Position Open to representative of charac- ter. Take orders shoes-hosiery direct to wearer. Good income. Permanent. Write now. Tanners Shoe Mfg. Co., 7-95 C St., Boston, Mass. AGENTS $17.50 daily. Bonus besides. Sell finest line hosiery. Seven months guarantee. New selling plan gets orders. Write quick. Silk hose free for your own use. Betterknit Textile Co., Silk, 232, Greenfield, Ohio. SELL America’s Quality Asko all brass Spark Plug; sample outfit free; openings for State and County dis- tributors; excellent profits: product guaranteed. Write “Asko,” Canton, Illinois. AGENTS—Genuine Broadcloth Novelty Shirts for wear with or without coats—Great Summer Sellers— Write quick for territory and FREE Samples. Cincinnati Shirt Company, Lane 1607, Cincinnati, Ohio. AGENTS $240 month. Bonus besides. New auto given. Introduce new guaranteed hosiery. 126 styles, colors. Finest silks. Credit given. Samples furnished. Wilknit Hosiery Co., Dept. 1632, Greenfield, Ohio. AGENTS. We have a whirlwind seller. Get details. Webster. 608 Wrightwood, Chicago, III. MAKE Much Money—Making, Selling Your Own Goods. Formulas, Processes, Trade Secrets. All kinds. ee Catalog Free. C. Thaxly Co., Washington, D.C. SALESMEN—get exclusive selling rights of a scien- tific drugless health oo needed in every home; unlimited possibilities! Write Radiumized Applicator Co., 1303w Fillmore, Buffalo, N. Y. AGENTS make $3.00 an hour taking orders for our 40 fascinating Kitchen LL yng No Competition. a quick. General Products Co., Dept. 31-F, Newark,

MARVELOUS patented invention, seals 3,000 enve- lopes hourly! Sells on sight $4.50. Tremendous profits! Big repeat business. Exclusive territory. Consolidated, 3 Nottingham Bldg., Boston. BRAND new solid brass household article. Greatest trouble saver on market for price. Keeps iron cord out of the way. Sellsin every home. 100% profit. Send 50c = 4 and proposition. R. L. David Co., San Jose, fornia. SALESMEN 600% Profit—Agents, Salesmen—Get inon this. Huge public installment buying created big demand for this article. Sold to merchants and others do:ng credit business. Three $7 sales daily net you $562 monthly. You should more than-double this with sub- agents. Five powerful selling methods. Article sold and backed by ironclad guarantee. Wire or write at once for valuable territory now open to hustlers. Busi- hess Builders, Dept. 10, Athens, N. Y. AGENT: Be a thousand miles ahead of competition. Patented product housewives want. profit. Commission in advance if wanted. Manager, Box 929, New Orleans, La. TOOL salesman for complete line of automotive tools sold direct to mechanics and repair shops; exclusive territory; 30% commission. Automotive Tool Mfg. Co., Milwaukee, Wis. SALESMEN—Get free outfit and make $90 a week taking orders for famous Taylor rain-proof, made-to- measure caps and knickers for men. Also eight other big profit-makers. Commission in advance. We deliver. fayloi Cap Manufacturers, Desk T-7, Cincinnati, Ohio. ARE = old at forty? See our advertisement on page 133 of this issue. The Electro Thermal Company, 4071 Main Street, Steubenvi'le, Ohio. NO MORE punctures, use Emmett’s Puncture Pro- tector. Cheap, clean, permanent. Free Sample. Agents Me Femmett's Products, 1026 N. W. 7th Court,

A SENSATIONAL seller. “Kleanezy,” the new mop with the steel plate. Housewives delighted. Eager buyers. Will send one Prepaid on approval to convince i how easily you can make $20.00 daily. Kleanezy Co., Dept. 7-L, Delphos, Ohio. AGENTS—Make $100 weekly selling real Irish aam- ask table linen; big profits; sells on sight. Supplied direct © Manufacturer’s price. Goods sent by mail. Send $5 or full size sample cloth 2x2'% yards and free book of samples. Amazing value. Brands Limited, Successors to James Lindsay & Co., Belfast, Ireland (Established 100 years). tev ALKER made $165 first day selling Collection Sys- $65 to doctors and merchants. Retails $6.50. Collects .00, costs $1.50. Adjustment Assn., Mobile, Alabama

Now Installed by Over Two Million Car Owners VER two million motorists throughout the world have now installed the Stransky Vaporizer on all makes of cars, trucks, tractors—even on an aeroplane. Learn here from their own lips how this queer little device has increased gasoline mileage and power and ended carbon, spark-plug and other engine troubles caused by faulty gas feeding. Read what competent authorities say. priced car installed a somewhat similar gas vaporizer as standard equipment on a recent model. Official tests have shown that most car owners waste 20 to 30 per cent of their gasoline by improper carburetion. Thousands testify that this device i saved them this much and more—in some cases u to 50 per cent. It is a simple, harmless piece of metal, not much larger than a dollar coin. A 12-year-old boy caninstallit. Andit is automatic and self-regulating. You just install it and forget about it. Then check results before and after using—and believe the evi- dence of your own eyes. This amazing device performs an

Then accept the inventor’s challenge to test the device on your car—AT HIS RISK! A Daring Offer The inventor will send the Stransky Vaporizer to any- body to test on any car. If it doesn’t save gasoline and prove satisfactory in every way—the test is free. What is more, HE WILL PAY A CASH FORFEIT if the test is un- successful. If you are as pleased with the device as other car owners have been, he offers an easy way to own it FREE OF COST! He guar- antees that it will not harm the engine in any way. Even though you read no further, isn’t the above as bold an offer as you ever read before? How The Invention Carroll.

FORD 57 Miles on a Galion J. T. Jackson, Mich., reports he drove a 1914 model Ford 57 miles on one gallon. CHEVROLET Miles on a Galion “We have tried them out. Chevrolet got 43 miles.”—F. S. DODGE 0 Miles on a Galion made over 40 miles per gallon on my Dodge between Brownsville, Texas, and Tam- pico, Mexico,”’—T. INTERNATION- AL TRUCKS Saves 41 per “I find it better than you recommend it. On the Inter- national truck we use we are saving by positive test 41 per cent in gas and our engine uses less oil.”” George Bell. additional service—a new, easy way to clean out already formed carbon deposits—the same way carbon is removed from the famous Diesel engine. Then, in addition, read what other car owners say it has done—increased power, low- ered gasoline cost, ended ‘“‘barks” and “spitting’’ caused by carbon and fouled spark-plugs. And you can prove the story on your car— at the inventor’s risk. Accept This Offer This coupon below will bring you full details of the offer that lets you test this device at the inventor’s risk—the test to be free and a cash forfeit paid by the inventor if you are not thoroughly delighted. Cent Here, also, is a wonderful oppor- tunity to make a handsome income —just showing this device to car owners and letting it sell itself. Read on the right how other Stransky representatives are piling up big cash profits. Over 5000 men have become Stransky distribu- L. Brown.

Works John A. Stransky, former candidate for Governor of South Dakota, and one of the best-known men in the Northwest, is the inventor of the Stransky Vaporizer and Decarbonizer. As evidence of its sound engineering principle, a well-known, high- The STRANSKY VAPORIZER Saves Gasoline J. A. STRANSKY MFG. CO., Dept. H-730 Pukwana, &. D. Resources Over $500,000.00 Est. 10 (Ten) Years tors. Last year they netted $300,000 in profits on this low-priced gas-saver. No experience required—we give you a written plan to follow that shows how to sell every car owner. If you want to make $75 to $150 a week, speak up now! The coupon below costs you only a 2c stamp.

Fill out your name and address below without obligation to buy anything. Address envelope to J. A. STRANSKY MFG. CO., Dept. H-730 Pukwana, South Dakota DG. oi cco0ssssssseagevestaeeamnen ene ss aa BEBIOIE os 50.5 0690000080864 0Se06 5550088 2 OGk eee te eee NID oc sidx nan scanke

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ees dint ELECTRICAL iV) AND MECHANICAL

Get into This—the World’s Biggest BusineSS Pay IT NEEDS YOU! 6& Thousan@ Milton Dollars paid every year for upkeep! Tremendous Op rtunities for Big Raises ay QUICK ph er ry Man— clip coupon ommon schooling all you need. I give zon Lifetime Employment vice— Lifetime Consultation Service too! Pll Train You AT HOME Get my Free Book. Find out how you can become a Big Pay man in amazingly quick time? Keep your present job. Stay home. You don’t have to leaye yous doorstep. Master every a of Auto AJ ork right in own home. See how I train you oa. QUICKLY, and Beeny to BOSS INTO BUSINESS av EON BIG OUTFITS Tools, Tool Bag, Portable Elec- * trical Test Bench, 303 Wir-

See b evesccaneadiybemadet ing Diagram Make Money QUICK Charts, and Spe- Send for thie amazing Free Book richt cial Electrical ge

OW! See how hundreds of men are Pd their salaries, making Big eztra pare-time money, and getting into Move “IN Yea Businesses St theirown QOutfit — all Free ma reW W'Sito et of Extra Charge. s. w. COOKE, Directing Engineer Chicago Motor Trainin Corporation Dept. B-25, 1916 Sunnyside Ave., ane AGO malt JOB-WAY COUPON B. W. COOKE, Directing Engineer, Chicago Motor Training Corporation, Dept. B-25 1916 Sunnyside Ave., Chicago, IIL. Send me Auto Book gad proof that I can become an Auto Expert at home in spare t Also send your 4 Outfits Offer. It is understood that this obligates me in no way.

Experimental

z — S WEA or cums

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Bearings, Belting, Blue Prints, Books on Mechanical and Scientific Subjects, Brass, Castings, Compressors, Gears, Lathes, Mo- tors, Saws, Shafting, and Supplies of every kind for Model Makers and Handy Men. Complete Catalogue 25 cents, which is otewed on first $2.00 order. AMALGAMATED SALES AND SERVICE CORPORATION 327-D South LaSalle St., Chicago, Illinois, U.S.A. MONEY MAKING OPPORTUNITIES SECTION Shop Equipment BATTERY and Tire Shop Equipment and Supplies at wholesale. Send for our latest catalog. Adams- Barrs, Columbus, Ohio.

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Wireless Power (Continued from page 115) serve simply as a channel for electricity. For instance, an isolated mining camp in the face of an inaccessible mountain might receive electric power to run the mining machinery from a beam shot through the air from the base of the mountain. One thing, Dr. Thomas says, is certain— with half the power of a modern broadcast- ing station behind it, a short-wave radio ray fo- cused in a narrow beam of concentrated power | would kill anyone who stepped in its way. Stray electric currents which it would induce | in a man’s body would instantly burn him up.

Here, then, is a veritable “death ray” —not a fantastic dream, Dr. Thomas points out, but like radio power a sober scientific possibility. In time of war, this ray would prove a terrible and awe-inspiring weapon. Radio rays of overwhelming power turned upon an enemy army would cause it to disappear in smoke. Along the radio beam might course powerful electric currents to complete the destruction. UT in its peacetime uses it would be of greatest service to man. High towers could be used to keep the deadly beam where it could do no harm as it transmitted vast quantities of power across the earth. At night a bluish glow would surround the transmitting tower from leakage of the high-tension current, and per- haps even the beam would glow like a search- light piercing faint mist. Smaller beams, less dangerous to man, might distribute the power at the receiving station. This would correspond roughly to the present system of using transformers to change the dangerous high-tension electric current used in wired power transmission into low pressure current safe for home use. Into your home, perhaps straight through the wall, the ray would enter, while the “half- wave receiver” would absorb power to light your lamps—not ordinary lamps, but a special type of electric light built like a radio vacuum tube—and run your washing machine and electric toaster. Can it be done? The “ifs” are merely matters of figures now. Scientists have taken away the mystery that cloaks radio power, and have shown how it is to be attained. Each by his own method, they are drawing nearer and nearer to its useful realization. With all the resources of great laboratories at their com- mand, they are working out the last practical details. Any day, now, they may announce to a waiting world that at last the goal has been achieved. Science Gives Shaving Hints HERE’S a good reason why many men lose their temper more easily when they shave. The nerves on the side of the face are linked closely to the anger centers of the brain, and disturbing them causes trouble. This is one fact brought out in a recent scientific study of shaving. Here are others: In stropping your razor, use a rigid strop, or, if you prefer a supple one, use a slow stroke. If the strop is too supple, or stroke too rapid, a tiny following wave in the leather or other material curls up after the blade and dulls it. Don’t let the blade get heated. Soft steel, such as that in safety blades, heats quickly, so in stropping them use a very slow and rather short stroke. Don’t dip your razor in boiling water just before shaving, for this softens the steel. Washing the face with toilet water be- fore soaping makes the beard soft and in- sures an easier shave.

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No time. was Expert | masters. p- portunities to “ior ee while studying. Day and or ng classes. Athletics. Enter any time. Low tuition— terms rite toda = your copy of 84-page iliustrated ‘‘Blue Book, ”* mailed MONEY MAKING OPPORTUNITIES SECTION Tuly, 197 Chief of Battalion (Continued from page 16) McSweeney already had the receiver off its hook at the listening phone. His flat fingers pushed open the switch of the telegraph key at the right of the board and tapped it twice. Hennessey was running from the rear of the room. Jim Burton jogged at his heels. “I'd of give you five more moves!” he was crying. “You ain’t no checker player!’’ Hennessey answered him. “Hush, will you? Listen for location!” McSweeney at the telephone repeated the crisp words of the operator at fire alarm head- quarters. “Corner of Hayden and Standard street. Standard and Hayden.” “Let’s go!” Kellogg shouted, and clawed up to his place on the right side of the driver's seat. RIVER CARLSON, there ahead of him, sagged down like a sack behind the steer- ing gear, while his wife waved goodbye from the driveway. Burton and Hennessey, still arguing, thrust their arms into rubber coats they snatched from the brass hose pipes on the tailboard. McSweeney, who had paused to bite off a chunk of tobacco, ran, as the great motor pumper jerked forward, and hopped to the rear step. Pipeman Stein still clung to the hose box. It was one minute past nine by the clock. Engine 26 racketed into the street, its bell chattering, motor grumbling. Men and boys halted in their Sunday night strolls to watch the brief, glamorous passage of crimson steel. “Hayden and Standard,” Captain Kellogg shouted to his driver. “ Better take the Ward street bridge. Truck 12 will be going that way; break an opening for us if there’s a crowd.” Five seconds later he muttered: “That’s only half a block from Schwart’s beef house, come to think.” He yanked the bell rope savagely, as if a new, hot fury had laid hold on him. Driver Carlson braced his feet and elbows, slowed the swaying engine, swung a corner with casual grace, and at once accelerated speed. *‘Open her up full,” the captain counseled. “Straightaway now. I'll watch the bridge . she’s down all right. Tender’s got his lantern out, giving us the highball. Open her ? up full—that’s good! HE engine plunged out of the tawdry lights of the stockyards business district into a region of vast darkness. Occasional blank building fronts lifted sheer from the sidewalks. The rancid odor of the stockyards was sharper here and mingled with the oily smell of the industrial river and the acrid breath of railroad yards. The ruby tail lamp of Truck 12 careened close ahead now. The lumbering length of the ladders made for slower progress than the compact power of Engine 26. It drew to the right of the road at a corner where a dim elec- tric light broke the sulky obscurity. By the glare of his own headlights, Captain Kellogg saw the commander of Truck 12 in the middle of the roadway, booted feet apart, listening, while a police patrolman waved his night stick. The pumper grumbled to a halt. A sharp gust of wind swept up the river and struck Kellogg’s sweaty face. **Where’s it at?”’ he shouted, tumbling down from the seat. “Don’t know,” the captain of Truck 12 answered. ‘“Smoke—all over the place. Officer smelt it, telephoned alarm.” He ran back toward his truck. Kellogg sniffed. ‘“That’s not coal,” he told himself. ‘“‘Not railroad yards.” Aloud he shouted: “Smells like lard.” His crew had slid down from the pumper. Axes in hand, they explored the dark with reckless feet. A trio of laddermen from the truck appeared out of the -gloom “Down that way!” the first of them Panted, “Smoke’s lots thicker.” Captain Kellogg's ax smashed the gate in g high wooden wall topped by strands of wire. A cinder road lay straight to Schwart's beef house. Far to the left cattle were com. plaining in their pens. To the rear, acrogs dis. tant roofs, shrilled the siren of Flying Squadron Number 5, arriving thirty seconds late. The smoke lay in black swaths on the warm moist cinders of the roadway, like heaps of dirty wool. Winds from the river stirred Lf Kellogg jammed the claw of his wrec' under the main south door of the beef de “Give a hand here!” he cried. Men strained, and the big door broke o Dead, frosty air pushed out, chill with the bite of ammonia and the sharp tang of smoke, ERE ’t is!” Kellogg shouted. “Lay, line, men. Eight section, round to the north end. Couple to corner plug, lay eight section, half-inch tip, hard suction. Get that, Carlson? Hard suction!” He backed out rapidly. Stinging smoke crowded after him. He slammed the door, That blasted wind from the river, pushing all the fire and heat this way!. He knew it would, Hadn’t he told Dargan so? Hadn’t he said » in his examination? “Keep this door shut!” he commanded. Ax in hand, he plunged around to the rear, There was one fence intervening. He rippeda hole through it with his ax, ready for hos, Midway across the north end of the brick wall, Kellogg found the rear door. He rattled th latch. He lifted his ax, then put it dom deliberately. **Where’s that line?’ he demanded of the dark. “Engine 26!” he bellowed. “Are you! dead or something? This way—here! Got to f wait all night?” Hennessey ran first, as a senior pipema| should, his arms wrapped about the great bras | nozzle. New white hose flapped at his rubber] boot heels. Behind him, struggling with th! stiff fabric folds, Burton was panting already. “Truck 12 captain pulled a box alarm,” kk called to his officer. Kellogg guided Hennessey to the door. “He did, eh? That brings Dargan.” McSweeney charged around the cornet d the building. Afar off Stein cried: “Ready, 26?” **All set!”” McSweeney answered. “Water!” Captain Kellogg demanded. E LIFTED his ax, and waited while at hissed through the tip of the noatk, He'd start no drafts till he had a good stream ready. A flutter of spray splashed against th wall. The ax bit into the timbers above the lock. The door withstood the first blow aml the second. It opened at the third. Ont more the breath of ammonia, of smoke dead air. The smell of curing beef. The ail of artificial refrigeration. The wind whined up the river at Kellogg’ back. “In and at it!” he commanded. “Find it men!” He had inspected the beef house often enough in preparation for this emergency. knew each of its intricate passages on its seven cold dark floors. This rear door, through which he just had come, opét merely into a narrow brick-paved entry, | low ceiling and heavy, exposed, whitew beams. At its opposite end another thick gave upon a long, cold corridor. This corridor extended south to the fu the building. There it opened by a series of doors upon the front verde : corridor was about a (Continued on page t July. |

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July, 197 July. 1927 stirred it, | | King iron -ef house, oke 0 h the bite 10ke, “ Lay in _ to the ay eight Get that, ig smoke | the door, | ushing all | it would, he said 9 nded. » the rear, e ripped a for hose, prick wall, attled the ; it dow led of the| “Are you | e! Got to " pipeman great brass nded. | while ait he nozsle, od stream igainst the above the blow an ird. Onc smoke ani . The ail : Kellogg’ “Find it yuse often gency. on Dar 0 ne, 0 antry, hitew thick 4 he fronté r a simi | ards, J} mn page t MONEY MAKING OPPORTUNITIES SECTION Chief of Battalion (Continued from page 124) hundred and forty feet long. Usually, in spite of warnings from the fire department, it was duttered with hand trucks, left by laborers at the end of the day. Two thirds of the way to- ward the front, and on the right, opened the proad shaft of the beef elevator. It was a t gaping crater, capable of immense drafts, extending upward seven tall stories to the fimsy penthouse on the flat roof. Beyond the shaft, and on the right, a narrow iron door, always kept tightly closed, gave upon the cooling plant, with its condensers coated with st. The second door that he was hunting now was no more than ten feet inside the entry, if Kellogg remembered rightly. It was a heavy parrier of varnished oak, about eight inches thick, insulated with cork lining. The latch had a long iron handle like the lock on a butcher’s cooler. He felt forward with the toes of his boots. He’d find that second door, _drag his hose through it into the corridor. AR across the river he heard the clamor of engines responding to the box alarm. Out in the yard the captain of Truck 12 was shouting, collecting his scattered crew The flying squadron commander cried: “Helmets, Squad 5, smoke helmets! Have ’em ready!” So Dargan was coming! Kellogg, hands stretched out ahead of him, discovered the second door. Let Dargan come! Let him stick his face in the south entrance! Wind was from the river. Wind was always from the river. Pushing smoke and fire through to the other end. Into the crew’s face if they attacked from the south. Only Dargan said not. He’d been a captain twenty-six years; maybe he was right. Maybe there was some other reason for going in from the south. Kellogg hesitated asecond. Then he pulled upon the long iron latch. He knew he was right! He’d enter from the north. “Stand aside there, I’m opening!” he warned Hennessey. He threw his weight against the handle. The door into the long corridor opened six inches. Heat puffed out. Heat saturated with fumes of ammonia and the nauseous odor of burning beef. Firelight shone dimly, hooded in yellow smoke. Burning rafters crackled. Decper in the basement sounded the destructive murmur of big flame. “Water!”’ Kellogg ordered. He slid to the left six inches, head ducked, right foot braced to prevent an outward explosion of the par- tially opened door. “Give her water any- where!” EGRIPPED the cold brass of the nozzle. Hennessey and McSweeney crowded close behind. Stein, coughing, was crawling forward along the line. Burton halted in the outer door according to orders. “She’s goin’ good,” McSweeney cried, “all the way through.” Burton ran into the entry. “Dargan’s here, sir!” he cried. you're in wrong; says come out... .” “Out?” Captain Kellogg turned the tip of the nozzle slightly to the right. “Up a bit!” he directed. “Hit her a mite higher. Wash along the ceiling. . . .” Acting Chief Dargan stormed through the outside door. , “Kellogg?” he screamed. “Kellogg, you in this way? Out with you! Are you a babe in arms, I ask you? Out! First company in and you take back door? Out with you! Do it right! Other end to. Get in front—front, I say—where you can see it comin’!” commander of Engine 26 whirled around and looked Dargan in the face. He heard cSweeney growl beside him, heard Hennes- “Says > sey swear. He hesitated (Continued on page 126) LAW OFFICES @ OPPOSITE U-S- PATENT OFFICE / Protect Your Ideas Y At the left is a view of my drafting and _ specification offices where oa large staff of experienced experts is in my constant employ. All drawings and specifications are prepares under my rere sonal super- vision. 4 i a7 OaTeIN : PNG ae “ CON gas Soy for an improvement on an old Office. another). Strict Secrecy Pre- served—Write Me in Confidence All communications, sketches, drawings, etc., are held in strictest confidence in strong, steel, fireproof files, which are accessible only to authorized members of my staff. Feel free to write me fully and frankly. Your case will have my personal attention. It is probable that I can help you. Highest references. But FIRST— clip the coupon and get my free book. Do THAT right now. every inventor should have. and the ‘“‘Record of Invention’ form, to- gether with detailed information on how to proceed and the costs involved. Do this NOW. 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We can proceed in the quickest, safest and best ways in preparing an application for a patent covering your idea. ur success has been built on the strength of careful, efficient, satisfactory service to inventors and trade- “ owners located in every state in the nion. Clarence A. ©O’Brien : Registered Patent Attorney ; 88-S Security Savings & Com. Bank Bidg., Washington, D. C. - Please send me your free book, “How to Obtain a Patent,” and your ‘“‘Record qf Invention” form without any cost or obligation on my part. ee eee eee eee eee eee eee ee eee eee eee eee eee (Important: Print or Write name clearly) 125 RID INVENTORS “Write for these FREE BOOKS)

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Originators of forms “Evidence of Conception.” Make More Money Read the Money Making Opportunities on pages 116 to 135 of this issue. MONEY MAKING OPPORTUNITIES SECTION Chief of Battalion (Continued from page 125) another breath. Then habits of obedience rose swiftly in him. Dargan was acting chief. “Close this door,” Kellogg bade. “Tight! Get around front, men. Shut down your pipe. Drag now, drag! Around front!” In the courtyard he heard Dargan’s voice. “Second line off Engine 14, I say. You, Truck 12, ventilate! Ventilate! Open her up! Get some air on it! Lost time enough!” ELLOGG ran ahead, back the way he had come. The line of Engine 14, Dargan’s company, already twisted into the south base- ment door. Kellogg followed it. Hotter here, immeasurably hotter. “Down!” he commanded. “Hit the ground!” He dropped to his knees. There was less smoke close to the floor. He hitched forward. This entry was exactly like the one he just had left. Dargan’s crew already had opened the insulated doors. They crouched at the left; Kellogg passed them. McSweeney crawled up behind him, lugging the nozzle. Hennessey followed, dragging line. Stein tripped midway to the second door, sprawled there, panting. Burton, who came last, eased the stiff, throbbing hose outside around the corner of the building. “Ready!” Kellogg grasped the tip. He pulled upward, then forward, on the shut-off valve. Water, released from its fabric bonds, pressed a stout white pillar against the fire. A little behind him and to his right, Engine 14 was washing down the ceiling beams. Fire filled the long corridor ahead. Flame in fan- tastic shapes blazed orange and purple with wisps of ultramarine. Smoke fluttered in yel- low, opaque pennants. EAT. ..smoke... burned air... ammonia. ..and behind it the wind from the river, sweeping through from the rear. Captain Kellogg muttered rebelliously and pulled his head deeper into the collar of his rubber coat. This was no place to attack it! He knew it now, if ever he had been uncertain. Lick it from here? It couldn't be done! He aimed determinedly at a new spout of flame on the wall. Ammonia rasped his throat. His white pillar of water ploughed into the turmoil ahead, eight hundred gallons a minute. Kellogg coughed; tough on a good crew, having to eat smoke like this. He hugged the nozzle, felt the throb of his engine back in the street, eight hose lengths away, the churn of its jowly piston pumps, the rumble of its racing mctor. Good old engine! She’d do her best! Suddenly in the turmoil behind him he heard Dargan crying out, bursting through the door. He was shouting his name: “Kel- logg! Kellogg!” The commander of Engine 26 sloughed deaf- ly at the flame. He'd had enough of Dargan for one night. A sudden splash of water dropped from the ceiling above his head. He knew what that indicated. Truck 12 had dragged its line up to the roof and was wetting down the elevator shaft. Dargan lurched toward him through the gloom. “You, Kellogg!” he shouted. “Are you quittin’ on me? Up and at it! Move in ten foot and give some firemen a chance back here!” Kellogg hitched ahead. He told himself vehemently that no man could live ten feet farther in with all that wind blowing through. More water dripped from the ceiling. More engines were working; must be fourth-alarm companies. “Get up forward, I tell you!” Dargan cried. “Hit her right!” Kellogg turned. He saw Dargan kneeling in the smoke beside him. The old man’s rubber coat was open. Firelight shone in his eves, j his unprotected eyes that should have baked: such heat. His helmet was pushed half off hg square gray head. His mouth was spread wide shouting. “Show you how a fireman does jt!” he |! howled into Kellogg’s ear. i He had pulled the hose of Engine 14 behind him through the insulated door. Ke} tugged on his own line. It would not move McSweeney prodded him with his boot. McSweeney lifted convulsively to his knees, then dropped back. “Get him out!” Kellogg ordered. He saw Hennessey drag McSweeney to air; pious-looking Hennessey, his mouth wi uttering horrible words. The hose move more easily now under Kellogg’s baked fingers, He advanced six inches. Dargan advanced | beside him. “We kin beat it!” the old man argued, Tr fire retreated suddenly and as sudden. ly leaped forward again. Another hot stream of dirty water from above splashed upon Kellogg’s neck. He moved his head! slowly, trying to shake off his helmet. }. must be scorching the hair on his scalp, the way it felt. His elbows slipped, and rested on the hot floor—more comfortable that way, | The ammonia was knocking him out, }e! had wits enough to realize. His mind refused. to act. How could old Dargan stand it, if he | a younger man... He heard a warning shout beside him. He saw Dargan rise to his knees, turn halfway around, drop back. An immense wrench of timbers thundered above the noise of the fire, “Cut off!” Dargan cried. Kellogg lifted to one elbow. Behind them, section of ceiling had tumbled. Skulking| flames, released from concealment, played er’ citedly with new drafts. The two lines of hog | wormed through under a heap of wreckage, Of his own crew, or of Captain Dargans, Kellogg’s seared eyes could make out no sign The passage was blocked. Fire marched’ triumphantly at them. | “Cut off!’ Dargan was screaming. | Kellogg lifted his hands. The nozzle did no respond to his urging. ‘Opening his eyes, ke saw that it lay upon the floor, spilling its wate! uselessly. He tried to pick it up. His helmet dropped as he lunged forward. Better off not so heavy. He touched the brass pipe—ani couldn’t lift it. Sloth overcame him. He was dizzy, needed to sleep. He sank down into th muddy pools on the hot cement floor and ther stayed; nothing mattered. .. . PRAY revived him. Spray, and a terrible croaking voice hurling epithets at him And the answering cries of men. The cella was darker. There was less flame. Kellog could see nothing. Barbed wire lodged in ls throat. His nose was afire. Ammonia. Smoke, Heat. Burned air. Then Dargan’s voice, stil pouring out abuse, commanding him to waket, to sit up, to show some guts. -Hands gripped his rubber jacket. His tos dragged on cement. His eyes felt the mereyd cool air. a give him a hypodermic,” someon said. At noon the next day Chief Marshal Pett sprawled across it. Kel saying, Sulli “Hel “ Ha’ chief. D: job on a hydraulic wind tha Dargan 1 “But marshal “ Nobo The job’: Dargan, chief. Or wiping th new job it assistant give it to “And | m Durn Let Yc OM chi Sess @ Vi orate pl built by Wagone: made a; Not ] group o homema with. O: were ma Althoug} wel showed ; G. Sullivan stopped his car jerkily and ® marked that he’d be durned. In a wicker chit on the front porch of Captain Kellogg’s how sat the captain himself. He was wadded wil bandages and wore a blanket around i shoulders. Opposite him, smoking a cigth the squat, square figure of Captain Kem Dargan sat astride the porch rail. “Not by the holy hydrants you won't? fuse it!” Dargan was (Continued on page If} playthin, spools, a Not o Ventiven enc assertion terials; valuable ee

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> haked in alf off his ead Wide, | it!” he|! 14 behind Kel ot Move, Kellogg ney lifted ped back, | other’ hot | splashed | his head Imet. It scalp, the rested on | t way. | 1 out, he id refused 1 it, if he, him. He 1 halfway wrench ‘of of the fire, id them, a Skulki layed es of hose wreckage, Dargan's It no sign. marched le did not | s eyes, he! y its water | Lis helmet | setter off; pipe—and 1. He was mm. into the and there July, 1927 MONEY MAKING OPPORTUNITIES SECTION "Chief of Battalion (Continued from page 126) saying as the marshal sauntered up the walk. Sullivan tramped heavily up the steps. “Hello, Kellogg. Hello, Dargan,” he said. “Have a chair, Pete,” Captain Dargan offered, “and Ill do the first talkin’. This Johnny-Jump-up was right yesterday. I should have attack-ted that beef house from the i ., you should,” Sullivan granted. “T see that, Kerry, soon’s I get there on the 4-11. That's why I sent the rest in from behind. You was wrong. You must of been neglectin’ your job of late, Kerry. Must of been readin’ too many books. I thought so, day afore rday, when they graded the papers for bat chief. You was a false alarm on all the fire fightin’ questions, Kerry. Only thing is, you got all the hydraulics stuff right.” “Hydraulics?” “Wait a minute. You did your talkin’.” The marshal turned, searching a cuspidor. Finding none, he spat over the porch rail. said impartially. “Got the rest, the straight fire business. But you won, Kerry. You had two points the best o’ him.” ? E?” Dargan demanded. “Me? I withdraws!” “Withdraw? That leaves Kellogg—”’ “Not me, sir,” Captain Kellogg spoke dog- gedly. “A chief's got to be up on hydraulics; rule book says so.” Marshal Sullivan took off his broad-rimmed black hat and scratched his head. “So there you are,” he told his first assistant later, back in central office. “Neither man’‘ll have it. Kellogg says Dargan drug him out, saved him from being burnt up. Says if a man can’t stand a little smoke he ain’t fit to be chief. Dargan says he won't ride into no chief's job on a book. Says he don’t think much of hydraulics. It’s knowin’ about such things as wind that counts. Won’t have it, neither one. Dargan run me off the porch.” “But who’s battalion chief?” the assistant marshal asked. “Nobody,” Sullivan answered. ‘Nobody. The job’s vacant. We’re just where we was. Dargan, bein’ rankin’ captain, still is actin’ chief. Only one thing's different,” he paused, wiping the sweat from his red face: “‘we got a new job in the department. It’s actin’ advisory assistant to actin’ battalion chief. Dargan give it to Kellogg.” “And Kellogg?” “Durned if he don’t say yes!” let Your Boy Build His Toys! a toys constructed by children with their own hands pos- sess a value not found in the most elab- orate playthings displayed in stores or built by parents, says Dr. Lovisa C. Wagoner of Iowa State College, who has made a special study of the subject. Not long ago Dr. Wagoner asked a group of mothers to describe the best homemade toys their children played with. Of ninety-five toys described, half were made by the children themselves. Although a large proportion of the chil- dren were less than five years old, they showed surprising ingenuity in creating playthings out of old boxes, string, paper, spools, and other odds and ends. Not only do such toys stimulate in- ventiveness, says Dr. Wagoner, but they sO encourage the qualities of self- assertion and mastery of available ma- terials; qualities which will prove in- valuable in later life. a “You muffed the hydraulics, Kellogg,” he. OUR OFFER: Your first step— | The inventor should write for our blank form “RECORD OF INVENTION.” This should be signed, witnessed and returned to us together with model or sketch and description of the invention for INSPECTION and INSTRUCTIONS FREE. Our Four Books Mailed Free to Inventors Our Illustrated Guide Book HOW TO OBTAIN A PATENT Contains full instructions regarding U. S. Patents. Our Methods, Terms, and 100 Mechanical Move- ments illustrated and described. OUR TRADE-MARK BOOK Shows value and necessity of Trade-Mark Protec- tion. Information regarding Trade-Marks and unfair competition in trade. OUR FOREIGN BOOK We have Direct Agencies in Foreign Countries, and secure Foreign Patents in shortest time and at lowest cost. Progress of Invention Description of World’s Most Pressing Prob- lems by Leading Scientists and Inventors ALL COMMUNICATIONS AND DATA STRICTLY CONFIDENTIAL INTERFERENCE AND INFRINGEMENT SUITS PROSECUTED IMPORTANT TO MAKE YOUR CASE SPECIAL AND AVOID DELAY YOU SHOULD HAVE YOUR CASE MADE SPECIAL IN OUR OFFICE to secure protection, save correspondence and obtain early filing date in Patent Office. To secure special preparation of yo ur case send $25.00 on account with model or sketch and description of your invention. Highest Reference Prompt Attention—Reasonable Terms Private Office, Victor J. Evans, with View of Patent Office Through Window WRITE TODA Yerncccccccccccccesnscececcessssnnaccene Free Coupon New Yo VICTOR J. EVANS & CO. Main Offices: 760 Ninth St., Washington, D.C. 1007 Woolworth Bldg. Chicago Offices, 1114 Tacoma Bldg. Gentlemen: Please send me FREE OF CHARGE your books as described above. vs rt) 3 oO > Qu Qu 5 o n r Patent Attorneys rk Offices Philadelphia Offices Pittsburgh Offices 518-519 Liberty Bldg. 514 Empire Bldg. San Francisco Offices, Hobart Bldg. Seececececegcsasesceeseecescsssas

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128 MONEY MAKING OPPORTUNITIES SECTION poe B5URawewy | A Now Era of Huge Bridges) 7 So writes W. H. Adams of Ohio in Aug- : ust 1925. V. A. Marini of California re- PET pen ger ae | orts $11275 sales in 3 months. Jacob | on a bridge made from onl i i i : a “ y three one-inch piles were provided to reach bedr : Gordon of — mo mf ig hoe in 2 ropes. A log bridge for the same span would cated at thirty-eight feet below a he: th ae in fone pence ee af Sh ye $3000 require two timbers twenty-four inches square Nothing but clay was found, and no piles af wit - - ~ es m one | and over 100 feet long, the cutting and placing greater length were procurable in South « a“ y- Bram bought one outfit April 5 and 7 more by : ” ae : A 28. Iwata, bought one outfit and 10 more | of which would be a superhuman task for America. Shipping from this country Meant muh witht’ a year. Mrs. Lane of Pittsburgh says “sold | natives. months of delay. The engineers rose to the ph pang hgh f Ri 8 Te “You doubtless know that modern wire- occasion by digging straight down from th|| of John Culp says: “E hing going lovely. | cable bridges, which stretch a half-mile or bottom of the cofferdam until they struck rock, Colnpette wiegoee septtaved = more in a series of graceful swings, are due to sixty feet below water level, filling the pit with — P world after all.” “Tien the genius of John A. Roebling. He started the masonry, and building upon that. American d . $700 ahead end of sec- first wire mill in this country only three quar- resourcefulness such as that is known th _— ond week. ters of a century ago. A few years later he world over.” nel startled the world with his kite over the roar- I asked Dr. Steinman how heavy bridge ~~ ing Niagara Falls, which carried a string that materials could be moved far into the interigr tay began the first great wire-cable bridge. This of such countries. he 821-foot span was one of the few suspension “Steel parts and machinery are designed ae bridges ever used for railroad traffic. It served and built in pieces which will fit the holds gf 7 in for almost half a century. vessels and limited hoisting equipment. When — necessary, they dre designed to be packed h : “TT BIRTY years later Roebling devised the dreds of miles on native animals. A steel cabk astonishing sweep of 1596 feet across several hundred feet long, for instance, is yp. Te the East River of New York. He had found _ rolled into a number of connected coils, each 7 that cables made up on the ground were un-_ carried by a mule. If one should go over, . wieldy, and the wires would not stay in place. cliff, the rest would follow—but the cables yil] _. So he invented our present method of spinning always arrive, and in one piece!” tide . + ode + S | the cables in place. He died before the - Furnish secret formulas, raw material and equip- | Brooklyn Bridge was begun, from injuries re- IS was my clue for introducing the sub- ment. Little capital required; no experience needed. | ceived during the surveys. But his monument, ‘Eee of accidents, for I had hesitated ty ee i Build A Business of Your Qwni | designed largely by rule of thumb, held all inquire how many men are killed per bridg cofferd No limit to the sale of Crispettes. Everybody likes | records for length for many years, being ex- erected. Sl ietwee } ag R. : 2 eciiow, it a confection. Write tor ceeded at last by the Firth of Forth bridge in “So scientifically are modern bridges de| “wh ent. Start now, in yourown town, | Scotland, a steel cantilever type, and in 1903 _ tailed and erected,” he said, “that very larg} | | askec Profits $1000 a Month Easily Possible by the Williamsburg span over the East River, spans are now built thousands of miles from “Spe Send | for illustrated book of fe. 4 Scaeeiion only four and one half feet longer in span. home, with much native labor and without a reachin enthusiastic letters from others—shows their placea “It was only two years ago that the Bear _ single fatality. The pioneers were the oneswho} | of long of business, tells how and when to start, and allin- | Mountain bridge over the Hudson attained the had to take the chances. Without electric power| t ‘ formation needed. Free. Write now! 1632-foot record, and only last year that the or modern equipment the marvelous structurg| 0 LONG-EAKINS COMPANY Philadelphia-Camden span achieved 1750 of bygone days required superb daring, and’ oa 747 High Street Springfield, Ohio | feet, almost exactly one third of a mile. But often at the cost of life and limb. Remember} | mogt now plans are under way for a span between _ that lofty bridges are nearly always located’ g Detroit and Windsor, Ontario, of 1850 feet; above treacherous water. coer} E ” TUD the Hudson River bridge at 179th Street, “One of the most tragic chapters in bridg “Bre New York, 3500 feet; and the Golden Gate building,” continued the engineer, “was that ater co COURSES _ bridge, 4000 feet. In addition,Gustav Linden- of the Quebec cantilever across the St. Lar Bridge thal has planned another Hudson River cross- _ rence. Its 1800-foot span still holds the worlds bridge ¢ THAT LEAD TO BUSINESS CAREERS or less ing at 59th Street, 3240 feet, while the pro- record for all spans. Efforts to skimp in mate jected Liberty Bridge over the Narrows of rial and in engineering services resulted in vie partner New York will require a span of about 4500 lation of some principles of conservative de large su , feet.” sign. Deficient sections were built. On Augut)} | gne-incl See An on eet Desition? I had heard of an unusual great suspension 29, 1907, a bottom chord buckled, causing te} | hattan experts will show you how, guide you step by step | bridge, the Florianopolis bridge, designed by collapse of the entire structure of forty millim} | hich } to success and help solve your personal business | Tr. Steinman for a remote part of South pounds, and the death of one hundred work and fou lems thru the time-saving lem Method. > : L a fnevensien olan caaiies 08 Ne pI America, and I asked him to give me some’ men. cables, Suties. Simply mark on the coupon the field in which you | details. “Investigation gave us many valuable le wire, a a one RY Ay Ty ; : ; sons. The Canadian government took ove gatline of our salary-increasing pian. Also copy. et ‘JT WAS conceived by the Governor of the project, prepared new designs unde “Ty out how the y plan starts average Santa Catharina, a remote state of south- the best practice, and almost doubled th} re thy Uh ish seed —— ern Brazil, to connect his island capital with weight of metal. Yet one defect remaineh)} | two mil am amma Find Yourself Thru LaSalle —= — the mainland,” he explained. “He did not either in a part or in the method of erectiot get som LASALLE EXTENSION UNIVERSITY live to see his lifelong ambition fulfilled. Many On September 11, 1916, while lifting the) | realize ¢ The World’s Largest Business Training Institution other disappointmerfts came to all of us before _ ton span which was to close the gap, and befor} | distance 783-R i we completed it. the eyes of thousands of spectators, something} “We. cents Cogito tem Seta “Its most unique feature, perhaps, is the gave way and the huge truss crumpled into} a... my nt in the business field first use of heat-treated eyebars in place of _ the river, carrying thirteen men with it. Buta} | thot in ¢ ghgehed below. Send alsa cork wire cables. This new steel is three times as year later an identical truss was lifted im} | tures wi obligation. strong as ordinary steel. The unique eyebars place without incident. primitive S Sooke ft ee facilitated the design of a structure with four Himalay O Traffic Management times the rigidity and with one third less steel “”J*ODAY we can meet almost every natunl O Modern Salesmanship for stiffening. We also designed a novel meth- foe on its own ground, from high water SB ieee od of taking care of expansion and contraction, _ floods to wind, snow, ice jams, and temperatutt; Ne O Law—Degree of LL.B. by permitting the main towers to rock on their changes ranging from sixty below to 120 abort) HA’ S ba mene 7 tem CO Expert Bookkeeping bases. Asa result, this bridge proved to be the Yes, and we even have to provide against fir the O Modern Foremanship O C. P. A. Coaching most economical suspension bridge ever built. When the Williamsburg Bridge was bel} | theory a O Personnel Management emcee 7 nies “Yes, we had many troubles,” he recalled. _ built over the East River of New York, a ft} | Universi 5 Baking ed eeCorre- Ol Effective Speaking “Our preliminary surveys, unavoidably lim- broke out on the scaffolds high up on a towe. isons spondence and Practice 0 Stenotypy ited, indivated rock was available for anchor- It damaged some of the 7696 wires m neve ing the cables on the mainland. When work eighteen-inch cable, which had to be his exper Name was under way I received a cablegram in New Since then good practice permits only sted Poisons it Present Position ... | York that no rock was found. I was asked to scaffolds at such danger points.” & marke cable a new design, for a bridge six thousand A few weeks ago twenty thousand peopled | able dro) Ee Rn nn nn neo —--~ | miles away! By extreme — = not only 7 San Francisco Bay region, a be . No no made designs for a new type of foundation, but __ the second largest cantilever bridge on the@ way, h Make Mor e Mone did it amie, and cabled the new plans the _tinent, observed a thrilling incident. nding : closing span, 750 tons of steel, was raised 19) | may \il] Read the Money Making Opportunities | fllowingday. . “Sing “At another point, forty-foot steel sheet feet in a few minutes, (Continued on page Would a | on pages 116 to 135 of this issue.

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ek, indi. iter level, 10 Piles of in South TY Meant Se to the from the | ruck rock, pit with American nown the vy, bridge | 1€ interior | designe e holds of | nt. When cked hun. steel cable ice, is un- poils, each go over a cables will g the sub- sitated to! per bridge the worlds p in mate ited in vio vative de-| On August ausing the | rty million dred work-| Juable les took ovet gns under yubled the remained, of erection. ig the 640 and befor something mpled. into h it. Buta) lifted into ery natunl h water and emperature , 120 above. gainst fir. was York, 2 fire on a towe. ires sphd be only sted d_peopled sed to viel on the dent. ; raised Ii on page I july, 1927 MONEY MAKING OPPORTUNITIES SECTION 129 - A New Era of Huge Bridges (Continued from page 128) without a hitch and without a man on bridge or closing span. Never before in history had the weight of ten thousand men been lifted so quickly and safely. I asked Dr. Steinman, the designer, how it was done. “Tt was simply a case of planning each detail beforehand,” he explained. ‘At each corner of the closing span, floating on barges, a two- and-one-half-inch cable was fastened, running over a sheave on the overhanging bridge, and down to a wooden box filled with five carloads of sand. When it was released the span natu- rally rose like an elevator, the four counter- weights of sand being slightly heavier than the span. It required just half an hour to lift each closing span. The novel plan saved time by permitting assembly of the spans while the bridge was being erected. “PPHIS Carquinez Straits bridge involved several unique features. The founda- tions, 182 feet deep, are in the deepest water in which such work was ever attempted. The tide is about seven feet per second, and has a range of almost nine feet. Teredos caused one group of piles to collapse in a few weeks. We | had to build a false wall around the timber cofferdam, waterproof it, and fill the water between with poisonous copper sulphate.” “What will be the ultimate limit of span?” I asked. “Speaking broadly, we have far to go before reaching a mechanical limit. Before the weight of long spans becomes too great for present types of piers, no doubt we shall have even stronger and lighter materials. Every pound of metal can now be placed where it will do the most good. Clumsy, massive designs of the past are giving way to more graceful and more scientific structures. “Erection methods, too, are becoming faster, safer, more efficient. The Brooklyn Bridge took ten years to build. Today a bridge of equal size could be built in four years or less. Holton D. Robinson (Dr. Steinman’s partner) so improved the methods of spinning large suspension cables, that the great twenty- one-inch and thirty-inch cables of the Man- hattan and Philadelphia-Camden Bridges, which he supervised, were spun in only three and four months, respectively. The Brooklyn cables, with slightly more than half as much wire, required twenty-one months. “TT’HERE is no reason, when dense traffic demands, why single suspension spans two miles in length cannot be built. You can get some conception of this span when you realize that it is more than three quarters the distance across Manhattan Island. “We are justified in believing that future bridges will be executed on so grand a scale that in comparison, our present vaunted struc- tures will appear as slight and crude as the primitive bridges built by the aborigines in the Himalayas or the Andes now appear to us.” New Theory for Poisoning HAT poisons kill by electrically shocking the nerves and brain, is the remarkable theory advanced by Dr. R. Beutner, of the University of Louisville medical school. How _ actually operate to bring about death never been satisfactorily explained. In his experiments, Dr. Beutner placed strong poisons in a new type of electric cell, producing & marked electrical effect, often a consider- able drop in voltage. No nonpoisonous substance acted in the same way, he reported. He suggests, therefore, that ic charges produced by a violent poison may kill a man in much the same way as would a bolt of lightning. PATENTS TRADE-MARKS -: DESIGNS FOREIGN PATENTS MUNN @ CO. PATENT ATTORNEYS Associated since 1846 with the Scientific American 1583 SCIENTIFIC AMERICAN BUILDING 24 WEST goth STREET New York City 522 SCIENTIFIC AMERICAN BUILDING Washington, D. C. 1311 TOWER BUILDING Chicago, Ill. 664 HOBART BUILDING San Francisco, Cal. 519 VAN NUYS BUILDING Los Angeles, Cal. wae Books and Information on Patents and Trade-Marks By Request. Associates in all Foreign Countries. Os (ommercialized re) ON A CASH OR ROYALTY BASIS Se PATENTED or UNPATENTED n Business 25 Nears -Complete Facilities-References.. dre ADAM FISHER MFe. Co. 183-D Enright Ave. T. Louis.Mo. INYENJIONS : INVENTORS 2:22: facts before applying for Patents. Our book Patent-Sense gives those facts; sent free. Write LACEY & LACEY. 48 F St., Washington, D. C. Send for our Guide Book, our terms, methods, etc. Send of your invention for Inspec- tion and Instructions Free. Terms Reasonable. Best Ref- erences. RANDOLPH & CO. Dept. 130, Washington, D.C. and Evidence of Invention Blank, sent Free on request. PROTECT NVENTORS your ipeas HOW TO GET YOUR PATENT, Tells model or sketch and description who derive larg- simple but vital Established 1869.

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130 MONEY MAKING OPPORTUNITIES SECTION July, 1977 july, 19 i Broncho-Busters of (fq! : RAILWAY POSTAL CLERKS| MEN—BOYS ' { the Air MAIL CARRIERS—POSTOFFICE CLERKS oan it (Continued from page 29) $1700 to $2700 a Year for Life Sst" 9 y po N ; - No “lay-offs” because of strikes, poor business, ete.—sure pay FRANKLIN INSTITUTE, Dept. K-264, Rochester, N.Y. would carry before failing. One model of every E chance. Common nense education suficient “no politcal nfusnce."” Spurustins ling haw wast appeiserens. =" ©) Fol | important part has been destroyed in this man. E TEADY WORK (.',.20205,22¢ 00 1: Hiaingy neu Gis aa 0 ner, so that before the first plane has been | - & the page. Oo icity Mollacter tsi7iate 22100) assembled ready for flight nearly a whole air. € eres adil Bis. CiRural Mail Carrier ($2100 to $3300) plane has been destroyed. APC MN sinsiuilheacasnedinabababeniiaddicnuns With such careful work it is virtually im. DS -6:1 0 ehbbee eed cee eeaewaeenb naman possible that the plane will fall to pieces in the air, which many people watching an initia] test flight think is likely to happen. Other things may happen, but no test pilot who has watched the construction of an airplane in a good factory will worry for fear bits of it wil] stray off in mid-air. Before he takes up that plane, the pilot will have a lengthy conference with the chief engineer, who will suggest how it should be flown and how it may be expected to perform, The pilot has flown from twenty to forty dif- ferent types of planes, among which at least two or three will bear some resemblance to the type about to be tested; therefore he has a good idea of how the new machine will act and feel to him. $50 to $100 wo, To AGENTS Amazing Anti-Glare Device For Automobiles preventsloss of life and makes big money salesmen. Motorists buy on 30-second ‘You can quickly qualify for big-paying positionsin Motion | demonstration. Treated by secret pr: [~ Picture, Portrait, Commercial or News Photography, OF | fead-tights Also used by Ony ass rea 4 start your own business. No experience needed. i . or CAMERA FREE rear new York Studion | Ssastapuialotter and sen ma ee See, to awents.No obligation. Ad- issinger | FTER their conference, the chief and the NEW YORK INSTITUTE OF PHOTOGRAPHY pilot stroll out to the plane, and it is Dept. 5 10 West 33rd St. New York | TH Seta, Gi, Sout. @ probable that they are feeling more tense than they look. For one of them is to take into the air a brand-new creation, worth $40,000, in which all the hopes of the factory are riding; the other is to learn whether his creation is good, no good, or “just another air- plane” —of which Uncle Sam desires no dupli-. a oe he eee Ses ase cece | Me Pi bios he coveralls Sa wis ea tno sro restag. Wri lan, pushes his goggles up on his head, and climbs . H F EF aboard the huge bomber. SESE, TEES SESS Sean Ave Silene SA. “Switches off! Gas on! Prime her!” says the pilot, as he pumps gasoline with the hand pump until the motor pump starts and re lieves him of that job. A mechanic on the engine platform primes } the cylinders with six pushes of a plunger, turns | vigorously the handle of the inertia starter, calls, “‘Contact!” and engages the starter. The starter flywheel, turning $5,000 revolu- tions a minute, engages through gears the motor’s crank shaft—and the engine wakes up and roars. It turns over slowly, warming up, while the pilot watches his gas and oil pressure gages. He snaps on his safety belt, tries his con- trols, and sees that the stabilizer, or tail-plane, TI, High School is set correctly. He has lived with that plane since it was a dream on paper, watched it grow to a beautiful silver-colored reality. Now itis Course in his at last, to play with or fight with, to handle 2 Years gently or roughly—gently, he hopes! This simplified, complete High School urse—specially prepared for home study teach Mail to mount Birds, Ani- a fe a eee En taxider. : Tan yartist Easily, quickly learned by men women and Bien Me dos wet tesutfal ee ste Bi Bre from Spare Time Sell and Mounting for - Free Booke iin all aboat. bow to learn taxi- dermy. Sénd Today. You will be delighted. Don’t Delay! Necthwestern School of Taxidermy °"*3m AN Wes “Patents of commercial value financed on royalty basis without expense to inventor. Mail models and copies of patents or full details to sot Holding Corp., 41 East 42nd Street, Ali Hafed, a Persian farmer, sold his acres to go out and seek his for- tune. He who bought the farm found it contained a diamond mine which made him _ fabulously rich. Ali Hafed over- looked the great oppor- T LAST the motor is warm enough. tunity at his door to go by leading professors—meets all 3 Steadily th luti t You can b far afield in search of i require- oteadiy ; e revolu 1on counter swings cents, coin wealth—which illustrates ments for entrance to college, business, and around the dial as the pilot advances the a Stamm throttle and the engine roars into full power. It runs “all out” for a minute before he 9.7543 Bo: throttles down, and waves the chocks from . t truth, leading professions. EARN $200 TO Fn aétinen 20 Other Engi If you like to draw, develop your talent. Your fortune lies in your hand. Present opportunities for both men ou ccess, a a and women to illustrate magazines, newspapers, etc., your inclinations may be, — can’t hope before the wheels. Then he taxies to the have never been excelled. Publishers are buying millions to succeed without specialized training. Let down-wind end of the field. swings into the ky ee pe pee ees in tin : , oviney inte artists as Neysa McMein, Norman Rockwell, Charles American School wind, checks his instrument readings, 1 Livingston Bull, Clare Briggs, Sidney Smith. ‘Fontaine Drexel Ave, & seth Street opens the throttle steadily. BOOKLET Ox an others. ach student ge n r- Dept. -B- Chicag — " sonal attention. No previous training is necessary. ~ o The plane rolls along the runway, gathers PROMPT! Te cians Sere wat of speed, lifts its tail, goes faster. The pilot eases Senc students and testimonial letters. Complete outline of course | American School, Dept H. 6-75 Drexel Ave. and 58th St., Chicago back on the control wheel, swings it a trifle to with all the details. Just write your name, age, occupation . ° level the wings pulls back gently—and the WATS and address in the margin and send it to us. Send me full information on the subject checked and “3 4 724 Ni how you will heip me win success in that line. plane is off the ground. He pushes forward on Avetinect the wheel to prove to himself that he has fore and aft control, and rocks the wings laterally. P He is only a foot in the air, and can shut off r and land if things don’t feel right. tade-ma But control seems normal. He eases back Handboo! the wheel, finds he is climbing at too steep an movemen angle, pushes forward again, adjusts the AL] stabilizer—and notes that the plane is slightly Formerly m. tail-heavy, a minor (Continued on page 181) of Iilustrating 7147 Federal School Bildg., |§ Minneapolis, Minn. 681-A Our:

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nough. swings es the power. ore he s from to the 'to the s, and gathers yt eases rifle to nd the vard on 1as fore terally. shut off os back nage 181) —— july, 1927 NEW INDUSTRY NEEDS MEN CONDENSER RE VALVE ER ELECTRIC Refrigeration over-night development of this bi ili dollar industry has created a C all s Yo u 2 tl shortage of trained men. Production, service, installation and sales positions are crying for competent men to fill them: tod: bi t rtunity. Greater profit | ay de Refrigeration or radio! Learn af home—be ready to fil @ ait Pay POSITION in just a few months. ind floor! Illustrated book of op- Ses in this magic new industry FREE. Be en >. _— neighborhood to learn about it. INEERING SERVICE gr ES, ENGINE Division 3120 N. Clark St., Chicago ——— @\ Auto Owners Wanted \..01 tines? Insured TIRES— the only tires in America Insured for One Year against all road haz- ards regardless of mileage. Insur- ance Policy with every tire. Made by the only tire factory in America selling its product through author- ized Salesmen-Agents. We offer ® opportunity of life-time to establish ! profitable tire business of your own. No capital required. Sales Kit and advertising helps furnished. We a SH Exclusive territory granted. ice UVDRO today for catalog and com- plete information about the Hydro any A a ADDRESS NEAREST B De'tts. HYDRO- UNITED TIRE. pala dl POTTSTOWN. PA. CHICAGO, ILL. ey DEMONSTRATIONS. New ¥: OISTURE HUMIDIFIER GAS SA AVER, va all oon rocks, tractors, Ss, engines, engines run ALL. THE TIME with the same wonderful efficiency they do on seed, moist night. Amazing records. G6ililes on | Gallon Ch Dodg 14s Greriand a7) 3 Heaex' 89: ete 4 . age} added power: faster pickup; \ engine doe r n, Amacing —_ from hard troubles. - uick Sales Bis Prost ceeet Start NOW, i FREE to Introduce Factory Sales - Distributors $2500 monthly. Spare er fulltime. WRITE TODAY. Address: Walter Critchiow, inventor, EA-120 St., Wheaton, Ili. STAMMERING] Ifs Guse and Gire % You can be quickly cured if you stammer. Send 10 cents, coin or stamps, for 288-page cloth bound book on Stammering and Stuttering. It tells how I cured myself after Stammering and Deuttoring for 20 years. BENJAMIN N. BOGUE 7543 Bogue Bidg.. 1147 N.111.St. indianapolis PATENTS BOOKLET FRE aes | oa PROMPTNESS: ASSURED ESULTS Send drawing pd model for canta vice WATSON E. COLEMAN, Patent Lawyer 724 Ninth Street Washington, Dp. &. PATENTS Trade-marks, Copyrights, Patent Litigation, Handbook with illustrations, 100 mechanical movements. Sent free on request. ALBERT E. DIETERICH Formerly member Examining Corp. U. S. Patent Office Patent Lawyer and Solicitor 27 years’ experience MONEY MAKING OPPORTUNITIES SECTION Broncho-Busters of the Air (Continued from page 130) fault. A bump under the left wing throws it up; a quarter turn of the wheel deflects the | ailerons and puts the wing down. “The plane answers readily for one of its size, but the con- trol works too hard. The pilot has been in the air five seconds, and he has discovered two minor faults. All that he will learn eventually about this plane will not come so quickly. But the flying char- acteristics of the craft are known to him in the first few minutes. He retards the throttle to easy cruising speed and looks at his gages. Oil and gas pressure, water and oil temperatures, are normal, though oil is running warm. Instinctively his mind will focus on the gage marked “Oil Out.” Though he will forget none of the others, that one will stand out. HE engine is purring like a big cat; the plane is climbing buoyantly. At 500 feet the pilot pushes forward on the control wheel, gains more speed, and does a gentle turn. Later he will turn with the nose of the plane stuck high in air, turn right at the stalling point, turn any way. But now the plane feels strange to him, though vaguely like all of them. With a watchful eye on the instrument board and the ever-mounting oil temperature, he does a series of turns that grow steeper and steeper until they are nearly vertical. ‘Then he throttles down and practices a landing in the air, gliding down at sixty miles an hour, pull- ing back his control until the plane is level, and, as it loses speed, right back until wheels and tail-skid are level and the nose is up in the air. Then the nose falls, the plane dives and comes out in a glide. Although he has been a thousand feet in the air, he has found exactly how the plane lands; he knows the right gliding angle, and the speed at which the machine is no longer flying but is settling, ready to sit down. He tries a few stalled turns, but no stunts, for this plane will | not be required to stunt. 681-A Ouray Bldg. Washington, D. C. After twenty minutes the oil temperature is too high. He throttles the motor and adjusts the stabilizer until the plane is gliding for the | field at a steady sixty miles, evenly balanced with motor idling. Near the ground he pulls back gently on the control until the plane is flying level, slowly settling and losing forward speed. All the time he is pulling just a little further back, turning the wheel slightly from side to side to keep the wings level laterally until the plane is just a foot off the ground, when he pulls the wheel right back until he is _ hugging it against his chest. The tail drops slowly and easily, and the plane settles on both | wheels and tail-skid for a “three-point” | landing. E TAXIES to the factory doors, climbs from the big bomber, and divests himself of helmet and parachute while the executives of the factory crowd around. “Well, how is she?” “Fine!” he tells them. “Just fine!” Then, in the general manager’s office, inti- mate details are given to the manager, the chief engineer, the president. Not quite so fine now. ““Well—”’ the pilot fills and lights his pipe, settles back i in a chair, and begins: He men- tions various types of planes and touches on certain of their characteristics, comparing the way they handle and the way this plane han- dles. The rudder is heavier than that of a cer- tain ship, lighter than that of another. Ailerons are hard to operate—almost as hard as those of that other type, for instance. Elevators, sensitive for a plane of this size. In short, call- ing upon his knowledge of types with which all are familiar, he tries (Continued on page 132) 131 “Four years ago you and I worked at the same bench, I realized that to get ahead I needed special training, and decided to let the International Correspondence Schools help me. I wanted you to do the same, but you said, ‘Aw, forget it!’ You had the same chance I had, but you turned it down. No, Jim, you can’t expect more money until you’ve trained yourself to handle bigger work.” There are lots of “Jims” in the world— in stores, factories, offices, everywhere. Are you one of them? Wake up! Every time you see an I. C, S. coupon your chance is staring you in the face. Don’t turn it down. Right now over 180,000 men and women are preparing themselves for bigger jobs and better pay through I. C. S. courses. You can join them and get in line for promotion. Mark and mail this coupon, and find out how. heme 5 CORRESPONDENCE SCHOOLS 7634-E, Scranton, Penna, Without . m=“ te lease send me a copy of your booklet, “Who Wins and Why,” —- full . rs about the course before "which I have marke $ BUSINESS TRAINING Pwned Salesmanship Advertising ey Letters how Card Lettering paerenny and Typing Civil Service Railway Mail Clerk Common School Subjects High School Subjects ‘Tllustrating [_jJCartooning i, AND INDUSTRIAL COURSES 1 Electric Lishtioe® Mechanical Engineer 5 oral and ) Banking Law (including C.P.A.) Accounting Surveying and ing Metallurgy se Pet Name Street Address. oooh City. Occupation... If you reside in “Canada, “een this ‘coupon ‘to the “Interne tional Correspondence Schools Canadian Limited, Montreal 1000 NEEDED INVENTIONS: Here is the most remarkable book ever offered to invertors. One Thousand needed inventions listed and _ descri Arranged as follows: General Problems; Automotive; Mechanical; Electrical; Chemical; Radio; Marine. Separate ey on the Ten Most Needed Inventions. This book may give you one idea that will win you a fortune. Nothing else like it has ever o— published. Com- piled at enormous expense. Edited by Raymond Francis Yates, formerly eee Editor of a lead- ing scientific magazine. Over 100 pages, -durably bound. Send no money. Pay awe only $1.00 plus postage on arrival (Outside U. S. $1.20. Cash with Order), Money back after 10 days’ examination if desired. Limited edition. Write NOW. core OF INVENTIVE SCIENCE Dept. 2 ter New York,

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MONEY MAKING OPPORTUNITIES SECTION “If it wasn’t for you and the training you gave me, Mr. Dobe, I wouldn’t be making $8000.00 a YEAR NOW” pub! ment. by _ Beck. lic build Sleewto facet House Designed by Beck This is but one of a great any balitinee designed is, churches and He has designed sc ings. Learned Drafting at Home! Beck answered my advertisement and got my free book on Draftsmanship. what I want you todo now. Beck was then a helper making $12.00 a week, but he took my simple, easily understood and qu learned course in drafting at home without iving w thing. 1 1 time I answered your advertisement,” writes Beck, “‘and wondered how I could take u your course as I was not able to save enoug out of $12.00 a week to make the first pay- That’s quickly his job. You can do the same ill you? “I often look back to the But I finally did it and it was the best money I ever spent in my life. to your training I am not afraid to tackle any work along drafting lines and can read- ily master all the architect’s plans. Mail this Free Coupon or Write Today for Thanks .FREE Book! Beck asked for the Free Book first. Will you ask for it today? Certainl. all by writing for Get it successful you can be. money you are not obligated at uecessful Dratsmanship.”’ it. Then make up your mind how js man ing real and you know , x - adage “‘What man done man can do.’’ So mail the Free Coupon be- low—or write a letter or a t card. Do that now. io man who is dissatisfied with what he is makin now should fail to get a read ‘Successful Drafts- manship.’’ DOBE EASY DRAFTING 1951 Lawrence Ave. Div. B-136 Dobe winners. Name Easy Drafting 1951 Lawrence Ave., Div. B-136, Chicago You may send me free your book “‘Successful Drafts- manship” and names and addresses of more Dobe Age. Address Broncho-Busters of the Air (Continued from page 131) to place in the minds of men who have not flown it an accurate idea of what sort of flying machine the new creation really is. Questions are fired at him and answered. The pilot talks on: the ship is too tail- heavy, excessive vibration in tail unit, aileron balances vibrate, oil runs far too hot—never thought that oil-cooler would do the work, anyhow—motor is rough; flies right wing low— this a mere rigging detail. The engineer sighs his relief at that last one, for he knows the pilot is running out of griefs—perhaps. After the conference those men know as much about the plane as if they had flown it themselves; that is, if the test pilot can convey his impressions intelligently, which is as im- portant as his ability to fly the plane. For no man is more useless as a test pilot than the man who flies anything well, but who fails to dis- cover and inform the chief engineer what is wrong with it. Following the test flight, and after a few changes have been made, the plane is loaded to full war weight and takes the air for a ten-minute climb. The naval inspector is in the gunner’s seat, with a paper on which he will note time, height minute by minute, oil and water temperatures, gas and oil pressures, engine revolutions, air speed, air temperatures. In this and succeeding flights the pilot will climb at certain predetermined speeds until he determines the speed at which the plane climbs highest in ten minutes. Then will follow climbs to “service ceiling,” the height to which a plane will climb until it fails to gain more alti- tude than 100 feet per minute. When it will go no highe has reached“ absolute ceiling.” } IS during altitude climbs that the skill of the pilot, or his lack of it, is apparent. An accurate pilot's climb will chart as an evenly- curved line, while that of a careless or inept pilot will chart as a line with frequent flat spots, indicating where he has failed to gain height. After the plane has made its climbs it is put through speed tests, which are “clocked,” or timed by ground observers over a measured mile or half mile. When the speed runs are over a field on the edge of a congested factory district, they offer varied thrills. In a large, heavily-loaded bomber flying at 100 miles an hour or more, the pilot has a vehicle that handles about as easily as a ten-ton truck. He must fly it just above the factory chimneys, head straight for the course on the field, and go pounding along as low as he can fly without hitting things. Across the field he goes, and a mile beyond the last marker to turn; for the plane loses speed on turns and must regain top speed before it passes the marker on the return trip. One mile past the other marker, turn, and back again. Three times each way over the course completes the speed test, unless the plane has failed to develop the speed called for in the contract. In that case the runs must be made again and again until the speed is at- tained—or until the pilot has demonstrated beyond doubt that the desired speed simply wasn't built into the plane. PEED-TESTING over a factory district field is quite as unpleasant flying as any pilot has to do. In the event of engine failure he has only roofs, streets, or vacant lots to land on. So he sits, hoping that the engine will keep going—and it usually does. If the sun is shining from a sky filled with scattered clouds, or if a wind is blowing, the pilot must be alert to counteract the effect of severe air bumps. Flying at full speed from five to twenty feet above the course, the plane will get a bump under one wing or the tail that will tilt wing or nose to the ground. The pilot i moves his controls to correct this movement before a wing tip hooks the ground—at typ miles a minute. And when a heavy bomberis flying fast the controls do not move It’s a case of quick perception and strength. There have been planes that none but strong pilots could fly safely. Such, in general, is the method of testing an airplane. Different classes of machines call for different kinds of tests. A pursuit plane, for instance, must be proved capable of doi any stunt possible in the air. It must roll, spin, and dive; it must “turn on a nj and have excellent maneuverability. For a training plane the important requirement js such stability that pupils can learn to fly in it with maximum safety. S EACH plane is built for some specific purpose, the pilot must conduct his tests to demonstrate that plane’s fitness for the work it has to do. And, above all, he must dis- cover every fault and pass it on to the chief engineer; for unlucky is the test pilot who passes as perfect an airplane that other pilots find to be full of objectionable faults! He will be summoned to confer with the factory pow- ers, and after that conference he will no longer be the first man up. For many years the testing of airplanes built by experienced engineers has been fairly safe. But the testing of freak airplanes pro- duced by enthusiastic amateurs is a horsefly of a different color—almost on a par with leaping from the Woolworth tower clinging to an ordinary cotton umbrella. A conspicuous example was the testing of an airplane designed by a boy of nineteen who had enjoyed a particularly brilliant career at school, and had joined the engineering staff of a motor company in England. Either the boy was a good salesman, or he possessed influen- tial friends, for he prevailed upon the company to build a large and exceedingly ugly airplane that he had designed to break the monotony— and possibly somebody’s neck. The company, it must be noted, knew nothing of airp but were pinning their faith on this embryo engineer, who had received considerable pub- licity, and who was generally referred to as the “Boy Wonder.” AN EXPERIENCED pilot was induced to test the plane, though he consented with some misgivings. However, he taxied to the far end of the field, headed into the wind, came tearing across the field toward where company officials, including the Boy Wonder, were standing. The twin engines roared i unison as they dragged that remarkable air plane forward. On it went until, when it way nearly to the little crowd of observers, it let) the ground and soared into the air like a lark Almost instantly, however, it exchanged thit larklike movement for one more nearly re sembling that of a skyrocket. Up to perhaps) seventy feet it shot like a mad thing, its tal hanging almost vertically beneath it. Thenit lost flying speed, fell sideways to the and crashed into fragments. As the company officials, who had beet standing in a fear-stricken bunch within hundred feet of where the insane machine had lit, dashed over to haul the pilot’s body from the wreckage, they were relieved and amaze to see him crawl out and stand erect. He) shook himself like a wet collie, and gh around him. For a moment he couldn’t sp He wasn’t hurt, but he was quite the angrié man in sight. ““Where—?” he gasped at last. “Whe that Boy Wonder?” But the Boy Wonder had disappeared. =

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uly, 1927 nent is fly in it specific his tests for the ust dis- he chief lot who r pilots He will ry pow- o longer irplanes n fairly nes pro- horsefly ar with nging to ing of an een who areer at z staff of the boy _ influen- ompaly airplane 10tony— ompany, ‘irplanes, - embryo ble pub- to as the duced to ited with to the July, 1927 a | A | y , tion for Buiiders! Up-iedate rmation for Buliders p-ti ate, Inside tone Guides and Trade References—handy, ‘et size; fully illustrated; easy to learn. Don’t ; ind! Be a boss! Study in spare time. Send for Guides covering your trade, on free trial. Pay $1 g month if satisfied. Mail Trial Coupon Today! RPENTERS curs *6 GUIDES Is Carpenters Guides. (4 vols.$6.) Ex- ay m handie every kind of carpentry job—in- ideor outside work, Pictures, plans, calculations and s make any jobeasy. New short-cuts, modern methodsexplained. Builders and contractors tions answered. Steel Square and othe problems solved. A practical Guide and help- ing hand for every carpenter; easy, quick methods of work that help you to be a leader. UMBERS cues *6 GUIDES Audels Plumbers Guides. (4 vols. $6.) A standard Guide explaining the theory and practice of all plumbing, heating, steamfitting, gasfitting andsheet metal work. Answers your questions on any job. Clearly explains the new short- cuts and modern methods so you can understand. A complete reference of the Trade and home study course, Folly illustrated, authentic, ao date, with complete Plumbers’Code, ASONS cies *6 GUIDES Audels Masons Guides. (4 vols. $6.) Every Bricklayer, Cement Worker, Plasterer, a, Setter and Stone Mason will find the answer to his questions and problems in this ; series. Inside Trade information on al the latest and 3 Course and complete reference library ing the Mason’s Trade; including A i di tical outline of steel construction. A ing hand for workmen and may HANDY LECTRICITY cine °4 Audels Handy Book of Electricity. (1 vol. $4.) A reliable authority and handy helper for every Electrical Worker, covering Wiring, Radio, Calcula- tions, Armatures, Maintenance, Motors, Batteries. A — lete Study Course and Ready Reference in one Guide for Flectricien,, Hnpineet and Student. bookssatisfactory,I will mail $1 in7 days FOURGUIDES _ $ IDES — THEO. AUDEL & CO. 65 W. 23 ST. New York City Please mail me for free examination TRIAL on each set orde and will mail $1 a COUPON § month on each set ordered until I have 6 FOUR GU $6 0 PLUMBERS ELECTRICIANS FOUR GUIDES $6 HANDY GUIDE $4 the books marked (x) below. If I find PENT purchase price. [] CAR NTERS MASONS Name Occupation Employed by To the Man With an Idea I offer a most comprehensive, experi- enced, efficient service for his prompt, legal protection and the development of his proposition. Send sketch, or model and description, for advice as to cost, search through prior United States patents, etc. Preliminary advice glad- ly furnished without charge. My experience and familiarity with various arts, frequently enable me to accurately ad- vise clients as to probable patentability be- fore they go to any expense. Booklet of valuable information and form for properly disclosing your idea, free on re- quest. Write today. RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington, D. C. 41-D, Park Row New York City TRADE. - MARKS REGISTERED MONEY MAKING OPPORTUNITIES SECTION Answers to the Sam Loyd Puzzles on Page 65 The Cost of a Lobster Lobsters were first sold at eight shillings per dozen, which would be at the rate of forty-eight shillings for six dozen, or thirty-two shillings for four dozen. Therefore, the cost of a single lobster would be two thirds of a shilling, or eight pence. You did well if you answered this puzzle in eight minutes. The Grandfather’s Marriage Suppose A and B are sisters. The man in question marries A; she dies, leaving him a widower. He then marries B, who survives him and becomes his widow. Thus he may be said to have married his widow’s sister, A, although she was his first rather than his second wife. If you have a good legal mind you should have answered this in five minutes or less. The Hare and the Tortoise The tortoise had run four and a quarter times as fast as the hare up to the time of their meet- ing, which was at a point where the hare had gone but one sixth of the distance of the course. Therefore, the hare now had to go five times four and a quarter times as fast as he went up to the time of their meeting, in order to finish on equal terms with the tortoise. For the dis- tance of that spurt the hare had to go twenty- one and a quarter times as fast, or twenty and a quarter times faster, than his time for cover- ing the first sixth of the distance. Fifteen minutes for the answer is a good rating. The Land Speculator The speculator bought 150 lots for $25,000 and sold them for $37,500. Thus his profits amounted to $12,500, or the original cost price of seventy-five lots. Fifteen minutes is a good record for this one. Mysterious Card Game The problem is readily solved by working backward. I must have started to play with $10.40. The baron put up $3.20 and the count $5.60. After the first round I had left $1.60, the baron $6.40, and the count $11.20. After the second round I had $3.20, the baron $12.80, and the count $3.20. After the third round, which the count and I won, each player had chips amounting to $6.40. Fifteen minutes is excellent. Aunt Mary’s Peanuts There were 1,021 peanuts. The first boy received 256; then a girl 192; then 144 to the next boy, and to the smallest child 108. This left $321 peanuts for Aunt Mary. Ten minutes is good. Pines Draw Most Lightning HE U. S. Forest Service has been investi- gating to find out what kinds of trees are most frequently struck by lightning. Pine, oak, spruce and fir, it reports, are most likely to be hit. In a study of 76,000 trees struck in the West, it was found that seventy-two percent of all that were struck were western yellow pine and Douglas fir. High, isolated trees are especially attractive to lightning bolts, the experimenters believe. And smooth-bark trees offer less chance of being struck than those with thick, furrowed bark. These facts are important to Uncle Sam's foresters in preventing fire hazards, for light- ning causes nearly 3500 forest fires in the United States every year. 133 Are You Hungry For Adventure. Popularity. Big Pay? THEN CHOOSE AVIATION! A™ you a red-blooded,' daring he-man? Do ) you crave adventure, : pee admiration, } and the ro wets of great crowds? Then why not get into the Aviation In- ustry—the greatest ad- venture since time began —-the test thrill ever offered to man? Think what Aviation offers you. The praise and plaudits of the multitude, Ordinary salaries up to $75 and better than $200 a week! And a chance to get in on the ground floor where rewards will ke unlimited! Aviation is growing so swiftly that one can keep track of all the astonishing new developments. Air-mail routes have just been extended to forma vast aerial network over the entire U.S. Many Come mercial Airlines and airplane factories are now being organized. Men like Henry Ford are investing mil- lions in the future of commercial Aviation for they see its great possibilities, Become An Aviation Expert? Get into this thrilling profession at once while UR the field is new and PICK YO uncrowded. Now—by a JOB unique new plan—you can quickly secure the basic and preparatory training you need to get started in the Aviation Industry at home, in spare time, Ex- perts will teach you the secrets and fundamentals of Practical Aviation— give you all the inside Airplane Instructor Airplane Engineer Airplane Repairman Airplane Assembler Ar ecnentoten Airplane Inspector Airplane Builder Airplane Salesman Exhibition Manager facts that = — _ pee ae gy hence your succes cer study of Aviation by this Alzptame otor remarkable method is al- most as fascinating as the actual work itself. Airplane Designer ing, reads lik tells you things about this astonishing profession_you never even dreamed of. Write for your copy today. AMERICAN SCHOOL OF AVIATION 3601 S. Michigan Ave., Dept. 136-B Chicago AMERICAN SCHOOL OF AVIATION 3601 S. Michigan Ave., Dept.136.p, Chicago, Ill. Without obligation, please send me your FREE Book, ‘‘Op- | seneiticnte the Atrpline iadasteye” Also infortuntion about your Course in Practical Aviation. : | | Name Address [an em _—____an—

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134 MONEY MAKING OPPORTUNITIES SECTION July, 1927 July, 1927 Perfect A-Current for Your Radio (Continued from page 62) water once a month on the average, but # special, small capacity batteries that designed for use with trickle chargers hays sufficient water space so that water need be added only once every six months or a Year. The use of a small battery and a trickle also practically eliminates the need for to determine whether the battery is in of a charge, although it is desirable to ¢ the battery occasionally when you first j it to make sure that the trickle charger jg keeping it fully charged. The most reliable method of testing is with a hydrometer, Remember that your battery will be injured by undercharging and that a moderate amount of overcharging is beneficial rather than othe wise. So if you are using a full-rate charger and there is any doubt in your mind as to whether the battery is fully charged, give it g dirty battery are two positive signs of neglect. Batteries are so well made nowadays that there is little chance for acid leaks, but to be on the safe side place the battery and charger on a rubber mat or set them in a large glass tray such as is used for photographic purposes. HILE the six volts developed by a stor- age A-battery are not sufficient to cause a shock or to break down the thinnest insu- lation, the characteristics of a storage battery are such that even the smallest size is capable of supplying an enormous amount of current if a short circuit occurs anywhere in the wiring. If, for example, the two wires from the battery happened to become short-circuited at the binding posts of the set, hundreds of amperes would flow through the wires and make them red-hot. The temperature of the wires would Now, for the first time, you are offered the opportunity to learn the trick of Mind Reading. You can become an ac- complished “Super-Mentalist Magician”, easily and quickly, Amaze your friends with your seemingly superhuman, psychic powers.. Make yourself the mag- netic center of every crowd. Mind Reading only a part of the Complete Tarbell Course in Magic Mind Reading is a_ vital past of the Magician’s training. Tarbell teaches you the most astounding acts and the princi- les on which all stage mind reading is sed. But in addition, you get a complete course covering the whole realm of Magic. Impromptu tricks; the science of tricks; sleight-of-hand; and even big stage illusions; everything to enable you to become a highly paid performer. For the business man, salesman, or profes- sional man, Magic as a “hobby” pays tremendous returns both in money profits and in social prestige. Make $250 to $1,000 a Month Magic has always been the most popular form of entertainment. Magicians are in great demand not only for the stage, but by clubs, churches, lodges, schools and for social affairs. High salaries are paid. Plenty of opportunity to make $25 to $100 a performance, on the side, with- out neglecting your regular business. The great Tarbell course will fit you for this work. It was designed for b gi but the profession has also adopted it for the new *kinks’’ and basic principles it teaches, Mail Special Offer Coupon! Special Offer for a Limited Time Only. You can get this great course, endorsed by the lg ya yt the Coupon NOW! oe Tarbell System, Inc., Dept. B-136 keep on rising to the melting point of copper and the short circuit eventually would be broken when the wire fused apart. Naturally, anything inflammable that was in contact with the red-hot wire would be set on fire. But there really is no excuse for fires of this type, with the correct use of a fuse. You can use special battery cable that is fitted with a fuse or you can connect a por- celain electric light socket in one of the wires leading to the A-battery, as near the B-battery as possible. Screw a five-ampere plug fuse in the socket. A fuse at this point is required by the rules of the fire insurance companies. Your storage battery requires the addition of distilled water at intervals. If the level of the solution in the battery is allowed to get below the top edges of the plates, the exposed parts of the plates are ruined and the capacity of the battery is reduced. Large size batteries that are charged periodically by a two- to five-am- pere charger require the addition of distilled a time and the charge is running continuously, couple of hours extra to be sure. The low-rate trickle-chargers cannot injure your battery even if you do not use the set for several days at OME day the research engineers may pro- duce 2 radio vacuum tube that will not need a storage batiery to heat the filament, but if you own fi storage-battery-operated set have no fear that any such development will make your equipment obsolete or that the elimina. | tion of the storage battery wiil improve results in any way. In fact, it probably will be many years before a set without a storage battery. will be anywhere near so good as your present outfit at anywhere near the same low operatin expense. The only possible advantage of ting rid of the storage battery would be te} eliminate the attention required by this part of your radio apparatus, and the use of a ge trickle charger and a modern battery already | has reduced that particular disadvantage. Is Your House Too Hot or Cold? (Continued from page 67) tween a snowy linen tablecloth and the problem of keeping a house comfortable in summer and winter. Yet flax is a basic mate- rial both for elegance and for insulation. It is a plant fiber of great toughness and resistance to decay. There are millions of tiny air cells between the fine long strands of the stalks, and these are multiplied by the process of felting. The substance is chemically treated to repel vermin, but there is no addition of a binder which might impair insulation value. The refrigerating industry used flax long before the idea of house insulation became widespread, and it is said that most refrigerator cars on the railroads yet employ this substance. From some of the cars junked for old age, the flax lining has been recovered in such a state of preservation that it could be used again. ** LAX is generally in quilt form of five sixteenths to one inch thickness and in various widths to fit between studs and beams or to go over them. There is also a form in which wood lath are attached to quilt by wire stitching, so that there is a ready base for interior plaster or outside stucco. An asphalt paper covers the quilt in this case, while the sizes are four by three feet and also thirty-two inches by three feet. The lath combination is Sawdust, the classic filling for ice house wall, has no better rank than .40, we learn. Comme gated asbestos paper is on a par with thi layers of the same and with wallboard made: stiff pasteboard, the index figure being 50) Sawdust is too loose, paste-board too dense, for the most efficient stoppage of heat flow. “4 ECAUSE asbestos will not burn, it hag perhaps received undue popular credit a) an insulator. Wrapping steam pipes with#) single thickness of it prevents little heat los It is necessary to have many layers, a good thickness and plenty of air cells. Cypress lumber is rated at .66, after come, in the order of their decreasing insulation} | value, the following materials: asphalt roofing} | fuller’s earth, white pine, asbestos mill boardy mahogany, Virginia pine, oak, maple, leather, rubber, celluloid, paraffine, gypsum plat ter, and asbestos wood (asbestos and cement): One hollow tile house insulated with cork board has saved sixty-two percent of heati cost, according to the owner. Giving the detail figures in a recent number of the journal issued] by the American Society of Heating and Ve tilating Engineers, he says: “The house is practically free from all drafts, and in summer the second floor is just as 1926 Sunnyside Avenue, Chicago, Ill. made either for magnesite or Portland cement as the first floor, due to the insulation on te SOSSSSSSESSeeeeeeeeeeeeeesseeeeeess: | plaster or stucco. ceiling of the second floor. . . The attic is ui Tarbell System, Inc., Dept. B-136 A mixture of flax and rye straw is manufac- _ heated, and in winter and summer has pra - BE pep emngerge = ye tured in board form and should be serviceable. tically the outside temperature. . . The sp grins full information’on the Tarbell System of The straw of any grain is tough, enduring and under the roof is not insulated because . No obligation on my part whatever. has insulating merit. Some day thisfact willbe attic is used only for storage purposes. recognized and millions of tons of straw now To have an attic that may be an oven ora ee burned will be put to use in house construction. ice box according to season while there I® Add Let us glance over the materials which, perpetual climate of comfort in your living ane)) OT re a ee ae according to the Bureau of Standards, have less _ sleeping quarters, is certainly a triumph of tit ee oe a ee A euasnedasgenaenanaessesesscsucacad insulation value than those we have considered. modern art of home insulation! Address .

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July, 1927 le to rst instal} charger jg treliable ter, be injured fe amount 1an other. ec ind as to , give it q e low-rate tery even 1 days at Linuously, may pro- will not ment, but 1 set have vill make » elimina- ve results July, 1927 ()UARE NEEDED IN TRAFFIC INSPECTION > iz this healthful, dignified position. 1 Train You for Traffic Inspection permo.salary and expenses You can get on the payroll of a great railway company— in a profitable and permanent profession where hours are regular, and work pleasant. You will be away from desk or shop, seeing new sights and faces each minute and prac- tically your own boss. Promotions are on completion of 3 months’ spare time home study, offer 3 position that will pay you at least $120 per month and expenses to start, or refund your tuition. For eight I have been training and placing men in this lucrative ession. See what they say about it. Mail coupon today for full information Seeeeeeaan- tr T. Jarrell, Pres., ieadard Business Training Inst., Buffalo, N. Y. You may send me entirely free, your booklet No. piv. 3 showing how I can earn $250 a month salary. Weavavin| COLLEGE Trained Draftsmen earn $60 to $100 a week. 4 months’ inter- esting study at Chicago Tech. fits 7a to earn big money in draft- ng’ sfertile field. Common school- ing all you need. Expert instruc- tors. Gpportunities or self-sup- MONTH hile studying. Free Employ- t Service. Day or Evening " Classes. Athletics. ter an Fin Iso intensive courses in Hagineering, Electricity. and Building. Write for free 84-page ‘Blue Book’' and facts about how to onalify for a high-pay drafting job in 4 months. us teet zoe st- Chicago Technical Colleg can’t come to Chi , study at home. ’ "FS he hte Tire Repair Business is good now/ §00 Nation - wide chain of Tire Surgery ‘ Shops now being extended to every uly town and city. Men handy with tools and willing to work are needed. We train you, furnish everything and establish in a shop of your own. Small restment req ired. Write for in- teresting book. o- iT CO. STORRS Some Ce. 7 A's 0 ee 1) on 7,6 3 A ee Be Your Own Boss man’s Digest famous hunting magazine. Hunting, fishing, trapping stories and pictures; information, tips, successful secrets on guns, dogs, tackle, all outdoor sports. Special advtg. offer—send 10¢ coin or stamps with name and address for 3 months’ subscription TSMAN’S DIGEST, Dept. 8-G, Cincinnati, Ohio. = | Se 1OF Am looking tor more ambitious young th] + fellows who want fine electrical posi- I tions paying $60 to $125 a week. you q Qualify, I will first put you thru a rapid, Oy but practical JOB-TICKET method of home-instruction in your spare time. Then I will help you pet placed in a permanent, sat- isfactory position, or I will refund the small amount charged for your instruction. Gram- mar school education and good references re- Gyired. Write today, Ask for 5 Job-tickets REE and my_ combination training and job ief Engineer Dunlap, Electrical Division. AMERICAN SCHOOL Drexei Ave. & 58th St., Dept.EB-75, Chicago 38 et, offer. Chief MONEY MAKING OPPORTUNITIES SECTION Here Are Correct Answers to Questions on Page 45 1. Mount Lassen, in northern California. While no lava has been discharged from it within historic times, steam and clouds of volcanic dust occasionally pour from it. 2. The Mississippi, the length of which, including the Missouri, is 4,194 miles. 3. The Aleutian Islands comprise a long chain of islands running southwest from Alaska almost to Siberia. A number of them are volcanic. They mark the tops of a great chain of volcanic mountains partially sub- merged under the sea, doubtless by the same subsidence of Alaska that produced the Bering Strait. 4. In southwestern United States, especi- ally in New Mexico, some of these houses are still in existence, inhabited by the Pueblo Indians. In prehistoric times there were many more of these villages. Houses three or four stories high were built of stone. It is believed that these stone villages were out- posts of the ancient Aztec civilization of Mexico. 5. The sponge of commerce is really the skeleton of an animal that lives in tropical seas. The great sponge fisheries are off the Florida coast and the West Indies. Here you can see natives fish up the sponge animals by thousands. The body of the sponge is allowed to decay and the skeleton is washed and bleached. This skeleton forms the “sponge.” 6. Brazil, which was originally settled largely by Portuguese immigrants. Just as North America is largely English-speaking because it was settled by the English, and just as South America is largely Spanish- speaking because it was settled by the Spanish, so Brazil has retained the language of its original settlers. 7. This famous stone is built into an ancient castle near the city of Cork, in southern Ire- land. According to an ancient legend, any one who kisses it will receive the gift of fluent speech. Many a traveler has hung his head downward from the top of the castle wall so that he might reach the stone and test its magic. 8. The hippopotamus. In Africa, vegeta- tion grows very rapidly and the rivers would soon be choked, were it not that the hippo- potami plow through them, eating the vege- tation and acting as a sort of natural dredge. 9. The most ancient writing of which we have any knowledge is that by the first inhabitants of Babylonia, 6,000 years ago. It is probable, however, that a crude form of writing has been invented by the ancestors of these people even before they came to Baby- lonia from Persia. 10. Mount Everest, highest peak of the Himalaya Mountains, northeast of India. These mountains mark the boundary between the British possessions in India and the independent Chinese state of Tibet. Mount Everest has been surveyed at 29,000 feet high. It never has been climbed. 11. This distinction belongs to the Mar- quesan Islands in the South Pacific, owing to their long distance from other land. 12. On the South Sea islands there lives the largest shellfish in the world. Its shell is fre- quently a foot or more in diameter. If a wader accidentally puts his foot on the crea- ture when the shell is open, the shell will snap shut and the luckless individual is caught. It is said that men have been held in this way until the tide rose and drowned them. 135 x 3505 \ 7¢ ar ‘ bean oma oke Trainea Men Earn Thi AGNES alat pay envelope get into ELECTRICITY Ds be satisfied with small pay—don’t be content with less] than $70 to $200 a week— the money that thousands of men no smarter than you are earning. You can make it, too! It’s easy! “Cooke” Training will show you how and prepare you quickly for a Big Pay Job in Electricity at $3,500 to $10,000 a year! LEARN AT HOME—EARN SPARETIME MONEY, TOO! You don’t have to quit your present job nor lose a minute from your daily work, With my famous “Work Sheet” and “Jcb Ticket” Method I teach you in your spare time. Just give me an hour or so each evening and you'll be amazed how quickly you'll learn—and not only the simple things but the fullest practice of Electricity! I give you the kind of knowl- edge that bosses the Big Jobs and commands the Big Money! What’s more, while you’re still learning —in fact, only a few weeks after you start with me I'll show you how to get sparetime jobs, how to do the work and tell you what to charge. Lots of my “boys” earn as high as $25 a week this way while learning. NOTHING LIKE “COOKE” TRAINING If you want the Big Money and want it quickly, be sure to see what ‘“‘Cooke” Training will do for you. There’s nothing else like it. It’s the Course with 10,000 boosters; the Course that big Electrical Companies select for their employees and that anyone who can read and write can easily master! Don’t make a final move until you've = and found out all about this wonderful training. IF YOU'RE NOT MAKING $70 A WEEK OR MORE—MAIL COUPON! Right now—this very minute—act to find out why the “Cooke Trained Man Is The Big Pay Man’”’ everywhere! Let me tell you the whole amazing ’ e Ill train story. Let me tell you about the Six Big Electrical Outfits and the you at home ! many other fine services I give you without extra cost. And let me send you my Big Book of Proof, Pictures and ee yn | Facts. No 7 Clip an mati coupon NOW! L. L. COOKE Chief Instruction Engineer L. L. COOKE SCHOOL OF ELECTRICITY Dept. 3-B - 2150 Lawrence Ave., Chicago, Ill, “4 FREE BOOK COUPON- MAIL IT’ L. L. COOKE, Chief Igstruction Engineer Dept. 3-B; 2150 Lawrence Ave., Chicago, Ill. Please send me copy of your Big Book of Facts— “The Secrets of Success in Electricity.’’ This does not obligate me. Name Address Resident: toR. A. Lee end this cou '° it, Ontario ©: of Canadal si Special Representative, 7 Medbury Lane,

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POPULAR SCIENCE MONTHLY Sixth Sense of Indust in the payee RTIFICIAL weather made to order! Any weather from the freezin ; Tyco s for the Home dry cold of Arctic regions to the steaming heat of Central Brazil « be produced in the testing box (shown in the photograph) used b Treos Office Thermometers research engineers to insure the quality of the receiving sets of the Rad An - Se rte human efficiency. Corporation of America. Tycos ti jermometers To enable you to get the most good from your bath. To give satisfactory service to their users in all parts of the world Radic have to be made to withstand extremes of heat and humidity in all parts of . we Home Set P ; Stee es Thermometer, Candy Thermometer, the world. A Jcos Wet and Dry Bulb Recording Thermometer is a vital a factor in suhing | the severe tests Radiolas are put through. q x a Thermometers Zrcos Instruments for Indicating, Recording and Controlling Tempera’ To help you maintain a temperature in your house are are" by industrial as well as research engineers wherever temperatures conducive to good health. Ske Quality Compasses to be exactly measured or controlled in fractions of degrees. ' To show you the right way in unfamiliar country. Whatever you manufacture, whether delicate precision work or steel for) Tycos Fever munities skyscrapers, candy or furniture, textiles or tools, paints or perfumery, if yout a worm ao. products go samp heat treating processes, you can save money and insure) Fcos Stormoguide ices in euetinn eneeGane haw cand uniform quality o production by using Zcos Instruments. ‘ with dependable accuracy. In the Fos Line of 8,000 different kinds of Heat Indicating, Recording Troe Hygrometer and Controlling Instruments, there are Zeos Instruments that will help you? To enable you to keep the humidity of the atmos- phere in your home correct at all times. take the guess out of manufacturing. ener literature on any type 0 instruments will be sent you on request. Or our engineers will consult with” Fycos for the Medical Profession you on the application of Jyeos to your particular manufacturing process. Zrcos Sphygmomanometer, Pocket and Office types. Fecos Urinalysis Glassware. mm. : Jyeos Fever Thermometers. Taylor Instrument Companies Di c J pom mad will show them to Main Office and Factory : Ask us, on a postal, for book- ROCHESTER,N.Y. - - U.S.A. ~~ dee on any of the above. Canadian Plant: Sees BUILDING, TORONTO SHORT & MASON, Ltd. Manufacturing Distributors in Great Britain rr iE ~ SI IXTH ~ SENSE ~ wer INDUSTRY 'Ycos Tempera ture Instrument, DICATING - RECORDING ~ CONTROLLING © This seal on a radio, tool or oi! burner advertisement signifies the approval of the INSTITUTE OF STANDARDS. See page 6. R. R. DONNELLEY & BONS CO., CHICAGO