Popular Science Monthly 1929-08: Vol 115 Iss 2

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JO ula ar August — —_ MONTHLY Founded 1872 aaiassnscalaet ianl o te nS, a. F me oe ei : TER ae ba a : a i } i te * & Rs ;

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WHAT WESTINGHOUSE IS DOING IN RESEARCH DRAWN FOR WESTINGHOUSE BY C, PETER HELCK r ie t IS) “9 on Lana WESTINGHOUSE MEASURES INTERNAL STRESSES IN MACHINE PARTS WITH THIS LIGHT-PROJECTION MACHINE Tomorrow’s electrification--on view today Spend today with Westinghouse research engi- neers and catch a glimpse of what Westinghouse is doing toward meeting tomorrow’s electrical requirements... In a quiet wing of the laboratories in East Pitts- burgh, slightly pungent with the fumes of mys- terious chemicals, specialists are applying electricity to chemistry. Time alone can tell what new electrical principles they will uncover to aid the industries that depend on chemistry for their advancement. A cathode ray tube sputters in a dark trator of energy man has yet developed. Nothing can live in the path of its rays. Westinghouse research is seeking its com- mercial value. tors for higher voltages, and new insulators with metallic Westinghouse JO rasstitetetee corner. We know it as the greatest concen- —. -> Wiring = Westinghouse glaze making it possible to solder cables securely to porcelain. There they are applying unusual tests to find the dynamic strength of metals, and the amount of permanent distortion they may undergo at high temperatures. Again they are developing inexpensive iron-base alloys to take the place of platinum in tubes and cells. Now we are among the grid-glow tubes and photo-electric cells. These super-sensitive tubes are the keys to automatic traffic controls, fire and smoke detectors, counting and sort- ing devices that need not touch their Apparatus subjects, and switches that will turn on lights automatically when daylight wanes. Thus Westinghouse research is ever looking forward, alert to the future needs and possi- bilities of every application of electricity The Sign of a Here we find men working on new insula- ‘"«*tinghouse Dealer -—J]eading the way to new economies for in- dustry and new conveniences and comforts for the home. cor ice. Us wit the tab It. acc cer!

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Co OSS te SS ~ oD Aucusr, 1929 POPULAR SCIENCE MONTHLY USED CAR ADVANTAGES Oftered By CADILLAC-La SALLE Dealers car— proper pricing —fair dealing. Bear in mind also that there is a remarkably strong trend to new Cadillacs and La Salles. Buyers of new cars have discovered, for example, that it is practically as easy to buy a Cadillac-built La Salle as it is to purchase a car of lesser quality and prestige. For only a little more a month (La Salle is priced as low as $2275 F. O. B. Detroit) they can enjoy what no other car —excepting Cadillac itself —can give them — the 8-cylinder superi- ority of the famous Cadillac-La Salle 90-degree, V-type power plant and invaluable features of handling-ease TIS rather significant that the Used Car business of Cadillac- La Salle dealers is more active than it has ever been in Cadillac history and the largest in volume. Quick turn-overs in Used Cars mean the buyers have discovered advantages that cannot be ignored. Certainly when Used Cars move rapidly out of the showrooms into the hands of eager buyers there must be an important reason. What are these Used Car advantages that are offered by Cadillac-La Salle dealers? For one thing, the Cadillac-La Salle dealer has placed his Used Car department on an equality with his new car department,— Which means not only that the cars are well conditioned and ready to deliver satisfactory serv- ice, but that the sale of a Used Car is surrounded with all the safeguards for and safety exclusive to Cadillac-La Salle. The market value of the cars they turn in is frequently sufficient for the down payment and they take care of the balance in easy monthly pay- ments by employing the convenient banking service of the General Motors Deferred‘Payment Plan. And so, because of this widespread trend, Cadillac- La Salle dealers have an exceptional variety of good cars of standard makes among their Used Cars. As there have been no forced sales these trade-ins have been accepted at reasonable market prices. There is no excess to pass on to the Used Car buyer. Values are exceptionally high. Consequently the Cadillac-La Salle dealer is in an enviable preferred position for the sale of Used Cars, as well as new cars, and the public’s recog- nition of this fact is the reason why these dealers are enjoying a remarkably active Used Car business. the purchaser that a repu- table dealer can provide. It becomes a matter of accurate information con- cerning the status of the CADILLAC-LA SALLE CADILLAC MOTOR CAR COMPANY Division of General Motors DETROIT, MICHIGAN OSHAWA, CANADA

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2 POPULAR SCIENCE MONTHLY | Aucust, 1929 LEADING ARTICLES T Astronomy Taught Himself to Ay J and Broke a World’s Record . By Michel Mok 17 Comet: The amazing ride to fame of an ex-cowboy and a former railroad ‘Our Solar System? oe ty mechanic Future Trip to the Stars s Portrayed Non Fhene Home froma Train! . . .» wae in Movies __. . 68 A startling new link in the chain of communication Discoverer of Stas... . 136 650 Miles by Plane for $4.68! . By Robert E. Martin 21 How the Diesel motor has invaded the aky A bil Tubes to Link City and Airport . . 23 utomovbues Men and mail may speed to planes tonngh giant tunnels" Cecsiies Westen e Bilten Dliens 0 Crushed in the Jaws of Arctic Ice . . Robert A. Bartlett 24 Year . 60 A veteran mariner’s greatest thrills, as es oy itzhugh Green Odd Tricycle Truck Turns in Its Has Our Earth a Glass Heart? . By John E. Lodge 31 Own Len ; 63 What you might see if you could look “through to China” Gas Pump Dial Safeguards Against A Man Who Always Does the Impossible __. Short Measure . 63 By Frank Parber Stockbridge 32 How Improved Roads Cut Your The dramatic story of a modern alchemist who gave us a new world eg we = ia - | Famous Flights . ; . 34 Fl ~o B | Tool B idea 88 A pictorial presentation of aviation’s astonishing advance Stop Light Indicator 88 Little Black Bag to Solve Crimes ° ° ° By H.C. Davis 42 Installing Piston Rings 88 Latest exploits of science, the supersleuth Spark Time Indicator . ; 88 Learn to Fly with Larry Brent . By Larry Brent 44 Locking Your Gasoline . 88 Through a betoth-taking tail spin with a greenhorn pilot Toy Dams to Save Lives . By Arthur A. Stuart 47 — , How engineers use models to solve gigantic problems Aviation At the Throttle of the “Big Hog” . . . By Arthur Grahame 52 Riding a two-hundred-ton locomotive over mountain rails Tonge Se Fly and Broke 17 How to Rescue a Drowning Man ___.. ._ + - ae 650 Miles by Plane for $4. 68! . Qi Valuable information presented in vivid pictures | Three Plan to GirdleWorld . . 26 Model Planes in Amazing Flights. ‘ . By Edwin W. Teale 55 First Rocket Plane _.. 26 Thrills and surprises in flying miniature machines Huge Flying Boats for Great — ny = 26 An Airplane “Plow orse” . . 27 SPECIAL FEATURES Leorning - Navigate. . . . 7 Gover'Bedigm:).):) 6 60 8 we ew By Herbert Pons New 500- Mi ieee.) . 27 A $15,000 Trifle ‘ . By Wallace Ames 4 Air Mail Saves a Day . 27 The financial editor’s ‘monthly counsel — “Lindy” Oils the F amily “Car” 28 What Insulation Really Does By Collins P. Bliss, M.A. 12 Maps Alaska from the . 28 Popular Science Institute offers helpful ‘advice to home builders New Valveless Motor. . . 28 Our Readers Say . ck 2 © # 6% te. *e..00 Oe A Perilous Perch . . - . . 28 Shot froma Warship . . . . 28 People in the Public Eye ‘ee ««- 14.082 Student Pilots. . . . 29 Little stories of unusual folks you "d like to know Checking the Air Records . . 29 Back of the Month’s News . . By Karl Vooght 48 Plane Dispatchers Now . . . 29 Absorbing facts behind the latest discoveries A Monoplane-Biplane. . . . 29 Beware of Radio Bargains! . . . . As Told to Newton Burke 70 Safety Overalls. . . . . . 29 Timely hints for the set buyer Cures Engine Cough . . . . 29 Two New Tubes—What They Do . By Alfred P. Lane 71 maar: | — : * £ & % = How new equipment adds volume and distance amous Fignts . »* Are You Interested in Aviation? . 41 Lining the Rooms of Your House_. By Roger B. Whitman 74 Model Planes in Amazing Flights 55 An expert’s practical advice on inside wall construction America’s Fastest Flyer. 136 Your Motorized Workshop . By William W. Klenke 78 Directions for making a Colonial, footstool . ew Ornaments for Your Home : . . By Berton Elliot 80 Eng ineering on Helpful hints for the amateur decorator Editorials ve. a a | Genius of Bridges |... . 30 Dollars Your Car Can Save You. : - " By Martin Bunn 84 | New ome noi Brid -_... yon Bridge . Gus and Joe tell why it pays to own an automobile | At the Throttle of the “Be Hog” 52 Tools That Help You See Better . By Henry Simon 96 | _ Invents a Power Plant to wo ar How mirrors and magnifiers aid the machinist . Small Streams. 59 fos ee Le uk, Ne, Dommlay Stearn a eeemz amamuahes memih ta, seg te pone, tat Crna, £25, cl count, Te Entered as second-class matter Dec. 28, 1918, at the Post Office senting in its editorial columns numerous stories of new products of ap New ¥ York under the act of March. 3 3. 1879; sdalts onal entry as second-class optepes, Eoouias | = ty-y 8 Menthi does aot underwrite the business met. os cen, a Printed a0 BK, A. ag ooee matte: tt x the Popular Menent aitinies fe for on - ees on Tian ‘authorized, OB Belence Bepartment, Canada. . Inc. Single copy, 25 cents. Yearly iy ‘eubeoripricns President it and Treasurer; R. C. Wilson, Vic Vice-President; A. L. Cole, Beoretary. IE

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Avoust, 1929 POPULAR SCIENCE MONTHLY 3 —$——_—— —— = Exceptional People He Finge ~ Lightning . . 30 Genius of idges : 30 A Man Who Always Does the Im- possible ‘ 32 Builds Remarkable Scale Model of Coal Mine 58 He Washes Dishes All Day to Test New Product... a of 62 America’s Fastest Flyer _ 136 Health and Hygiene Cleaning the Air of Dust .. 49 Deadly Chemicals Purify City Drinking Water. . 57 Drafty ee Better for Our Health? . : 61 Oxygen Piped i in | Hospital P 63 Joy and Sorrow Upset the Diges- tion, Says Expert. ; 66 Germless Arctic Islands the Healthiest Spot? . . 68 Scientists Above Par Phy sically . 69 Laboratory Discoveries A Poor Shot Led to Tinless Tin Cans . 50 Fountain of Racing Atoms May Explain Aurora . 62 Smartest Children Are Strongest . 62 New Rustless Steel Cuts Glass Like a Diamond... 63 Curious Facts Revealed by Pro- peller Tests .. 67 Camera and Tiny Furnace Tell How Fuel Burns . oe lee ee Nature Victim of the Rattler ._. 51 Tails Handicap Squirrel “Chan- nel Swimmers” . 60 Windows of “Health Glass” Make Hens Lay More ._. 60 Dyed Trees and Give Us Colored Lumber 69 New Devices ae the Home Paper Bags for Kitchen Refuse . 76 Convenient Kitchen Sink ._. 76 New “Air-Pocket” Base Turns Saucepan into ‘Waterless Cooker”... ae bo Door Laundry Hamper — a | Nigt ht Lamp Goes on When Main ights Switch Off. 76 “Waterless Cooker” Prepares Whole Meal ata Time. . . 76 Helps Fill the Baby’s Bottle . . 77 Can Opener. Scissors Grinder, in Same Bracket 77 Rolling Electric Ironer Has Table Attachment . 77 Turn the Crank and You Have Potato Chips. . . 77 Apron Resists Grease . 77 A Toasted Sandwich a Minute from New Grill . . 77 Hinged Bracket Saves Time in Hanging Clothes . 77 g& Cans Inventions Now—Phone Home from a Train! 20 Refine Ore with Thunderbolts . 49 Turntable Device to Stop Rail Crossing Jolts . . . . . 59 “Electric Eye” Turns on the Lights. 59 Novel Pipe Wrench Grips Like a Human Hand 62 High ae Grinding Tool for the Shop 62 In i Machine Sorts ‘Screws, uts,or Bolts . . 63 Novel Draftsman’s Compass ‘De- signed for Precision. . 64 Combines Shadow Boxing with Bag Punching. 64 A New Way to Get That Exercise 65 Mechanical Archer Tests Arrows — Defects. ‘a ai 65 an ewriter ‘Lam hie ~ wed oie 3 r 65 Electric ‘Board “Boy” Posts Stocks k 66 Microscope Casts Its Wonders on a Screen Strop This Safety Razor Like a Straight One... 67 New Tieeuenenee Easy to Read 68 Mechanical Money Changer “Spots” Counterfeits . . . 69 Photography Aerial Photos by Night. 27 Rare Books on the Screen for All toReaad ... ieee | Radio Ten-Pound Radio Transmitter for rr | ABGeebmemse.. i.» « «| & Solder or Binding Posts? . . . 73 B-Eliminator Condensers . . . 73 How to Use 32-Volt D.C... . . 7 Plugging in the Short-Wave Set . 73 Ships New T Canal Barge . . . 48 An “Old 1 Ironsides”’ as Small as Your Hand . 58 Thrilling W haling Scene Depicted in Model . 59 Rudder in Bow Aids Liner to Make Sharp Turns . 60 New Fire Boat Pumps 12,000 Gal- lons a Minute. 60 Two 1,000-Foot Steamers Planned in En land. 63 Warship'’s name Range Guns Fire Tons of Stee 69 Unusual Facts and Ideas Tubes to Link City and Airport . 23 Has Our Earth a Glass Heart? . 31 Vacuum Tube a Mile Long . . 48 Why Metals Grow Tired , 50 A Poor Shot Led to Tinless Tin 50 g Emergency Beading Tool . t New Processes and @ Facts about Poison Gas in Cleve- land Tragedy 50 What Do You _ about Time- ieces? 51 Philadelphia i in Miniature, : a $100,- 000 Toy City 58 Perfumed Glue and Shoe Polish . 59 Pearls 25,000 Years Old Found in the Rocks. 60 Mountains of Waste Paper Sal- vaged by Machiner . , Skulls Used as Drinking Bowls . 61 = e Dance of Smoke Seen er Microscope. 61 pV wom Tests Poison Gases on Hosts of Tadpoles . 64 Curious Mineral ‘Squirms ‘and Sweats under Heat .. 64 Warship’s Oarsmen Train in ‘the, Fighting Top . 64 Secret of Film Pictures Found in Cattle Food! . . ~~ oe Tunnel Diggers F ind Gold . . 65 Ancient Roman House Had Fur- nace and Bath . 65 Five-Million-Dollar War on Fruit Fly Pest .. 68 Seais Depth Finder May Locate Sunken Gold... » 2 ae Germless Arctic Islands the Healthiest Spot? _.. . 68 Army Tanks “Lock Horns” . 69 Spending Millions for War on Mos- quitoes ‘ . 134 For the Home Owner When Front Doors Need Paint . 90 Reproducing an Old Chair . . 104 How to Drain Your Ice Box . . 106 On the Hunt for Old Lights . . 108 Building Garden Woodwork . . 110 How to Make a Gun Cabinet. . 112 Knotty Lumber for Boxes. . 113 Trellis for Flower Pot ._. . 114 Reseating a Chair with Cane . 120 Painting in Damp Weather . 122 Hints for the Mechanic Doctor Owns Marvelous Shop . 92 Motor Wheel Drives Boy’s Coaster 111 Twenty-One Tools from Files. 114 Novel Saw Rack aie . 118 Hints on Sharpening an Ax . 124 Ideas for the Handy Man This Model Flies cores OI U Novel Mount for Shi Tops, Crosstrees, an Blocks - . 86 More Comfort at the Beach . . 100 Fishermen’s Knots r . 102 Home Worksho Chemistry . . 107 Blueprints for Home Workshop . 109 Toy Foot-Propelled Auto . . 110 A Shake and Guess Game. . i Wizardey i in Wire Puzzles. _. 116 Old Photographic Films Make Good Stencils . . 118 Homemade Gluepot . 119 Pattern for Cutting Moccasins. is In This Issue—Hundreds of Fascinating Articles Tell the Latest News of Laboratory Discoveries, Scientific Triumphs, and Amazing New Inventions

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ee ee . - nae SS oe See POPULAR SCIENCE MONTHLY Aucust, 1929 SUCCESS! Why is it that with a crowbar you can dislodge an object many times heavier than yourself? Answer: leverage. “Give me a lever and a place to stand,” said the wise Greek, Archimedes, “and I will move the earth.” Today, money is the lever with which the work of the world is accomplished. Little can be achieved without capital; with capital, almost — everything. When you invest in sound, strongly secured Real Estate Mortgage Bonds you are fashioning a lever with which you can remove the obstacles to success and happiness. Our booklet, “How to Build an Independent Income,” has helped put the lever to fortune in the hands of thou- sands of men and women. The coupon below will bring you a copy; mail it today. Tue F H.SmrriCo. Investment Securities—F ounded 1873 Smith Bld¢., Washington, D. C. Branch offices in New York and Other Cities eee eee eee eeeeeeee A $15,000 “TRIFLE” Frank Ditmar applies simple arithmetic to his investment program and learns the true value of 2% extra By Wa.wace Ames, Financial Editor I “‘I guess I am just a sap,”’ mourned Frank Ditmar one evening the first of the month. He had drawn his salary, made a deposit in the savings account and was looking at the red ink figures representing interest credits. “‘What makes you talk like that?” inquired Mrs. Ditmar. **Look at this bank book and you'll see,” said Frank. ‘‘We’ll never get any- where at the rate we are going. For two years we have been depositing $50 in the bank regularly each month. What have we to show for it? The magnificent sum of $1,251. In two whole years the interest on our savings has amounted to only $51. At that rate we will not be able to retire on an independent income, even if we live to be 100 years old.” **You are no sap,” replied Mrs. Ditmar. “You are just a little impatient. We may be worth only $1,251 now, but I for one am mighty glad we have that much in the bank. Aside from a nest egg for the ‘rainy day’ we have formed the habit of saving and that is worth a lot— a whole lot more than the $51 interest our savings have earned to date.” “Just the same,” insisted Frank, “I wish we were getting ahead faster.” II For fully a week Frank Ditmar held to the same attitude toward his family’s financial future. Getting ahead by regu- lar savings and nominal interest continued to seem like slow, discouraging work. But a surprise was in store for him. “I made a date for you tonight,” announced Mrs. Ditmar, when her hus- band came home from the office. “‘The representative of a firm of investment bankers was here today. Mrs. Reid sug- gested that he call on us. He has a propo- sition that the Reids have become very much interested in. It sounded so good to me that I asked him to return this evening and talk with you. After you have heard his story I think you will get some new ideas regarding our money problems.” At eight o’clock Mr. Fisk, the invest- ment salesman called. He explained the principal details of a security that paid 6%, but Frank Ditmar showed a mini- mum of interest. “‘What’s 6%?” Frank argued. “‘That’s only 2% more than we are getting now—just $20 a year on $1,- 000. A mere trifle—not worth bothering with. I'd just as soon plug along at 4% as to get 6%. Unless I see a chance to make a killing we might as well stick to 4% bank interest and reconcile our- selves to the fact that we will never get rich. And I have just enough common sense not to risk what money we have in any get-rich-quick scheme.” “You are just the type of man I like to talk to,” said the investment sales- man. “‘As you know, this 6% security is a sound investment—not a get-rich- quick scheme. I cannot promise you sudden, fabulous wealth if you make this investment. But the 2% extra that you get over 4% bank interest means a lot more to you than you realize. Did you ever try to figure out what 2% extra means to you?” Frank admitted that he had not. It just seemed to him an inconsequential trifle—$20 a year on $1,000 as he had already mentioned. “It may surprise you,” suggested Mr. Fisk, ‘‘to learn that 2% extra may mean thousands of dollars greater independent wealth. It may mean gaining financial independence as many as five to ten years quicker.” “That begins to (Continued on page 5) FINANCIAL WORTH AT AGE 60 Through Quarterly Investment of Various Amounts (Interest Re-invested) Comparing 4% and 6% Quarterly Compound Interest : $150 Quarter! 225 Quarterl $300 Quarterl Starting 8 Gain at , Gain at Gain at at 4% 6% 2% Extral 4% 6% 2%Extral 4% 6% 2% Extra Age 25 .| $45,861 $71,454 $25,593 | $68,791 $107,181 $38,390 | $91,721 $142,908 $51,187 ER 34,851 50,429 15,588 52,276 75,658 23,382 69,702 100,877 31,175 35.. 25,828 34,835 9,007 38,742 52,253 13,511 51,656 69,671 18,015 40..4 18,433 23,250 4,817 27,650 34,875 7,225 36,866 46,500 9,634 45. 12,273 14,649 2,276 18,559 21,973 3,414 24,746 29,297 4,551 50 7,406 8,262 856 11,109 12,393 1,284 14,813 16,525 1,712 Through Single Investment of Various Amounts (Interest Re-invested) Comparing 4% and 6% Quarterly Compound Interest . 2,500 Investment $5,000 Investment $10,000 Investment Starting $ Gain at Gain at Gain at at 4% 6% 2%Extral 4% 6% 2%Extral 4% 6% 2% Extra Age 25.......| $10,068 $20,100 $10,032 | $20,136 $40,199 $20,063 | $40,271 $80,398 $40,127 | Tee & 8,251 14,923 6,672 16,502 29,947 13,445 33,004 59,693 26,689 36. .3.4. 6,762 11,080 4,318 13,524 22,160 8,636 27,048 44,320 17,272 40. 5,542 8,227 2,685 11,084 16,453 5,369 22,167 32,906 10,739 | Segere 4,542 6,108 1,566 9,084 12,216 3,132 18,167 24,432 6,265 (RE 3,722 4,535 813 7,444 9,070 1,626 14,888 18,140 3,252 Av a ~ - SS YALA BR REE. “RS, ~ oe

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SS = CD mee SS Oo —_ or Mm RO FUN ft OD Mt ee rere OP me Dm | SS Fo —See oP ~~ =e @ 3 a AuGUST, 1929 The Foundation of Fortunes Just as the office building that . reaches high into the skies must be built on a firm, lasting founda- tion, so must one’s financial struc- ture be buile solidly on the foundation of sound investment. Fidelity First Mortgage 6% Real Estate Bonds provide the financial backing for many of these income- producing buildings which we see in course of erection and at the same time serve as the foundation forthousands of personal fortunes that are built to endure and yield good returns. May we send you a copy of the booklet, ‘‘The House Behind the Bonds” which explains why Fidel- ity Bonds should form the founda- tion of your investment plans. I BOND.* MORTGAGE ry ENTEERPresides® ew INCORPORATED 1913 4uUM 660 Chemical Bldg., St. Louis 1188 New York Life Bldg., Chicago 378 Colorado Nat’! Bank Bidg., Denver y, POPULAR SCIENCE MONTHLY “FISCAL—MANAGE D” INVESTMENT TRUSTS You’ll never grow rich by accident Thousands of people are trying to do it. Buying this stock and that on tips... hunches .. . “‘inside inform- ation” which proves to be outside mis-information . . . trusting to chance . . . getting nowhere. There is a better way for you. Invest in the common stock of Financial Investing Co. of New York, Ltd., which is an investment trust. It owns hundreds of stocks and bonds, spread over 30 countries. Each security is selected, O. K.’d and watched by United States Fiscal Corporation, whose experts do noth- ing but manage investment trusts. Your dividends flow from earnings and profits under this scientific sys- tem. Think what a powerful force this puts behind your dollars! Will you investigate today ? Send for our “Four-Year Analysis” of FINANCIAL INVESTING CO. of NEW YORK, Lid. Ask for Booklet J-7 SMITH. REED & JONES INCORPORATED Investment Securities The Chase National Bank Bidg¢. 20 Pine Street New York ! A $15,000 ‘‘Trifle’’ (Continued from page 4) sound interesting,” said Frank, “if what you say istrue. Can you prove it?” “*Sure I can prove it—prove it by sim- ple arithmetic. That’s just why I came here tonight. This little black book con- tains a lot of interest tables, showing how money grows at various rates of interest for different periods of time. **First let us look into the matter of doubling your money. According to the table, $1,000 at 4% interest, compounded every three months, grows to $2,007 in 17% years. At 6% interest, compounded every three months, the same $1,000 doubles itself, to be exact, grows to $2,013, in 113% years. 2% extra may seem like a trifle to you, yet that trifling difference in your favor shortens by 5% years the length of time required to double your money. **Now let us figure out another calcu- lation. Since it takes 174 years to double your money at 4% quarterly compound interest, how much more than double your money would you have in 17% years if you got the 2% extra—6% instead of 4%? According to the book you would have $2,835. In this example the ‘trifling’ 2% extra means $828 in your pocket. You may spurn $20, the difference on $1,000 in a year, but $828—that’s a dif- ferent matter.” “Yes,” agreed Frank; “that begins to amount to something. I did not realize that such an insignificant difference could pile up to such figures, or mean so much in time saved.” **Since you are interested suppose we carry this mathematical study a little further,” suggested Mr. Fisk. “Let us find out what the 2% extra means on monthly amounts of $50.” A little figur- ing produced the following comparisons: $50 MONTHLY Quarterly Compound Interest Gain at 4% 6% 2% Ex. 5 Years. . $3,325.00 $3,503.00 $178.00 10 Years.. 7,382.00 8,221.50 839.50 15 Years.. 12,332.00 14,576.50 2,244.50 **Possibly,”” suggested Mr. Fisk, “‘you would not get excited over the prospect of gaining $178 in five years, representing 2% extra for that period on a $50 month- ly investment. But you can’t lightly pass up the chance to gain $2,244.50 which is the 2% extra in 15 years. This last cal- culation demonstrates how rapidly your gain accelerates with the passing years.” “That’s almost unbelievable,” ejacu- lated Frank Ditmar. ‘$178 gain in five years and $2,244.50 gain in 15 years— without increasing the monthly invest- ment! But the figures are there. I guess they must be true.” ‘Let me draw one more mathematical picture,” requested Mr. Fisk, “‘a picture of your comparative financial worth at five year intervals up to the time you are 60 years old, assuming that from now until then you save $50 monthly and in- vest it each three months in units of $150. How old are you now?” “Thirty,” an- (Continued on page 6) etire mn |5 years os gousr Pacecnt Hoiag Dudget by investing in safe First Mortgage Bonds Follow the definite plan given in the new edition of this famous 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 in- dicated and absolutely safe—independent of luck, business genius or speculation. Every fact has been harvested out of the 48 years’ experience of Cochran & McCluer in the first mortgage investment banking business. The plan is so simple any one can under- stand it—so definite any one can follow it—and so certain no one can fail. In addition to the Financial Independ- ence Plan and the unique budget sched- ule, the book gives suggestions that en- able you to enjoy more of the good things of lite, both while building your inde- pendent fortune and after you have at- tained it. We invite the most skeptical to read this gee, straightforward, interesting book. hone, call or send coupon. We employ no salesmen, therefore none will call. MAIL THIS FOR [NEW EDITION anes eee eet ttt ae f Cochran & McCluer Co. °®™* 4 5 46 N. Dearborn St., Chicago } ; Please send me, without obligation, ! a copy of the new edition of your! mows “How to Retire in = i City. State. eeeseeeoeesewesens Cochran &MChuer Co, Established 1881—Never a loss to any investor 46 North Dearborn St., Chicago, IIl. Telephone Central 0930 The Electrician’s Wiring Manual By F. E. SENGSTOCK, E. E. Contains all the information needed for the proper installation of lighting and power systems in houses and other buildings. | It completely covers inside electrical wiring and construction in accordance with the National Electrical Code. Pocket size—flexible binding 448 pp. Price, $2.50 POPULAR SCIENCE MONTHLY 250 Fourth Ave. New York City

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NE Are Women Smokers Turning Men to Pipes? Men of America, awaken! The old story of Samson and Delilah is being played again in a modern form! The lovely ledike of our land are filching one by one our few remain- ing rights! buetep ... the vote... the ci ttes . . » no longer have we these comforts to ourselves. But one joyous right still re- mains our own—pipe-smoking! Every day men who have never smoked a pipe before are learning that it is the sweetest, purest, most econemical form in which tobacco can be smoked! Especially those who have chanced to start with the tobacco that comes in the famous blue tin. Read Mr. Bockmeyer’s letter. (His and all other letters from Edgeworth smokers are absolutely genuine—unpaid and un- solicited.) 270 Woodridge Street Woodridge, N. J. February 21, 1929 Larus & Bro. Co., Inc. Richmond, Va. Gentlemen: I received your sample of Edgeworth, and after giving it a fair trial I want you to know that it is better than any tobacco I have ever smoked. The whole family enjoyed the aroma. I will surely recommend Edgeworth to all my friends. Yours very truly, (Signed) M. Bockmeyer Mr. Bockmeyer is right. It’s barely pos- sible to puff purer melody on the air than comes from the golden grains of Edge- worth. Edgeworth is one of those marvelous mixtures that bring peace on earth and good will to your pipe. Mild, surely; yet with a full-bodied character to its Burley blend that almost invariably wins over pipe-smokers on the very first few puffs. Try this FREE offer now! If you’ve never smoked a pipe, let us send you free some generous pipefuls of Edge- worth Ready-Rubbed smoking tobacco. Simply write your name and address to Larus & Brother Co., 108, 21st Street, Rich- mond, Va. When you’ve smoked that first lorious pipeful of dgeworth, just ask yourself if you’ve ever smoked tobacco in &@ more en- joyable form! A wager you won’t. Edge- worth smokers have been tell- ing us for twen- ty-five years that Edgeworth is THE smoke of smokes for them! On their word we stand. . « e- Both Edgeworth Ready-Rubbed and Edge- worth P. 4B Slice come in various sizes from ee, small et packages, to handsome pound humidor tins. Plug Slice Edgeworth is packed in thin slices, for pipe-smokers who like to “rub up” their tobacco in the palm of the hand. POPULAR SCIENCE MONTHLY A $15,000 “TRIFLE” (Continued from page 5) swered Frank. A little more figuring produced the following table: $150 QUARTERLY Comparing 4% and 6% Compound Interest Gain at 4% 6% 2% Ex. At Age 35...$ 3,336 $ 3,521 $ 185 At Age 40... 7,406 8,262 856 At Age 45... 12,373 14,649 2,276 At Age 50... 18,433 23,250 4,817 At Age 55... 25,828 34,835 9,007 At Age 60... 34,851 50,439 15,588 “Just look at that ‘gain’ column!” ex- claimed Frank. “It goes up thousands of dollars every five years.” “Yes,” remarked Mr. Fisk, and you will note that the trifling 2% extra is a =, $15,588 when you are sixty years old. “Some trifle!” was all Frank could say. ‘‘ You have sold me. Now let us lay out a program of investing so I can get the 2% extra.” i The figures used in this investment story were taken from a compound inter- est book. In actual practice no investor would achieve the actual results shown. If a few days’ delay occurs in making monthly or quarterly investments, if the exact amounts referred to in the examples are not invested, if investments are made in securities which pay a little more or a little less than an even 6%, or if any other similar irregularity takes place, the final result is altered. However, the practical result of getting 2% extra—6% instead of 4%—is demonstrated by the figures worked out by Mr. Fisk. They correctly show what a surprising difference 2% makes over a period of years. The moral of this story is as applicable to the man or woman with several thou- sand dollars accumulated as it is to the one who is just starting to build his for- tune. Of course, the larger the sum in- vested the more important the 2% extra becomes, but it is an important item, even in small amounts, as Frank Ditmar learned. It would not be sound judgment for Frank Ditmar to take all his money out of the savings bank and invest it in securities. PopuLarR SctENcE MontTHLy has always advised its readers to keep a nest egg in the bank for emergencies. But since Ditmar had a snug sum in the bank he very properly started on a long term program to gain the 2% extra that he could obtain from sound securities. One may be inclined to.think of invest- ment in securities in terms of thousands rather than hundreds of dollars. As a practical matter it is just as easy to in- vest in hundred-dollar units, or even smaller amounts. You can buy one share of stock a month, or two shares, or three— any number that you have money on hand to pay for. Or you can arrange through many investment banking firms to invest on the partial payment plan, spreading Aucust, 1929 your payments over a period of ten months or so. At the beginning of this article appears a table which helps you to figure out what the 2% extra may mean to you when you reach age 60, either on an investment or a single large amount or quarterly in- vestments of a smaller amount. To Help You Get Ahead T= Booklets listed below will help every family in laying out a financial plan. They will be sent on request. **How to Build an Independent Income” is the title of a new booklet by the F. H. Smith poe ap | which explains conclusively how people of moderate means may obtain financial se ity. ‘55 Years of Investment Sery- ce”’ describes the history of progress of the F. H. Smith Company as well as making an attractive suggestion in first mortgage real estate bonds. May be obtained by addressing the home office of The F. H. Smith Company, Smith Building, Washington, D. C. The House Behind the Bonds reminds the investor of the importance, not only of studying the investment, but of checking up the banker who offers it. Address: Fidelity Bond & Mort- gage Co., 1188 New York Life Building, Chi- cago, Ill. ‘*The Investment Trust from the Inves- tor’s Viewpoint,”’ presents an explanation of this form of investment in easily understood terms, illustrated with some interesting examples of how the general investment trust will help the man with $100 or more to get ahead. Pub- lished for free distribution by United States Fis- cal Corporation, 50 Broadway, New York. Ask them for Booklet IT. How to Retire in Fifteen Years is the story of a safe, sure and definite method of establish- ing an estate and ouilding an independent in- come which will support you the rest of your life on the basis of your present living budget. Write for the booklet to Cochran & McCluer Company, 46 North Dearborn St., Chicago, Ill. How to Get the Things You Want tells how you Can use insurance as an active part of your rogram for getting ahead ieonsiclly. Phoenix utual Life Insurance Company, 328 Elm Street, Hartford, Conn., will send you this booklet on request. The Guaranteed Way to Financial Inde- pendence tells how a definite monthly savings oes will bring you financial independence. rite for this booklet to Investors Syndicate, 100 North Seventh Street, Minneapolis, Minn. The Making of a Good Investment tells how 614% can be made on investment in First Mortgage Bonds in units of $50, $100, $250, $500 and $1000; how the bonds are protected an how simple it is to purchase them. . For a copy of this booklet address United States Mortgage Bond Company, Limited, Detroit, Michigan. Four-Year Analysis of Financial Invest- ing Co. of New York, Ltd. In charts, dia- rams and statistical tables, this booklet ana- Freed the first four years of operations of one of the older of American general management investment trusts. Published by Smith, Reed & Jones, Inc., 1405 Chase National Bank Building, New York. a i te OIE a a ee ab =o & @ BR me a? -«-~

Page 9

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RARE ee ne Avucust, 1929

POPULAR SCIENCE MONTHLY

FROM CO NTROL PANEL TO HORNS BACK OF Lat

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“From behind the. screen these horns We TE yl <4 rik EQUIPMENT = sive the movies @ i HK \ : equipped for ghd pr Maintaining * ’ alee ge the film the illusion “7a mesh . ‘ ove — * attac: Ls ym : =I “Teas

WHAT MAKES THE PICTURE TALK? Your enjoyment of a Sound Picture depends largely on the quality of apparatus used. It pays to go to theatres equipped by the makers of your telephone — the Western Electric Company

dee you go to hear | a Sound Picture you wish to be certain that the voices will be clear and natural; that the musical accompaniment and the sound effects coming from the screen will be thor- oughly pleasing. Near you is probably at least one theatre which ° assures just that, because it is equipped with the

To Theatre Exhibitors People know good Sound re- we uction when they hear it. ey are quick to appreciate the high quality assured by Western Electric equipment. If your theatre is thus equipped you will render a service by displaying that fact in your advertising and in lobby and outside signs. For addition- al information address Elec- trical Research Products, Inc., 50 Church Street, New York.

Western Electric Sound of considering their patrons’ The sensitive Sound Picture microphone (C), designed for stu- dio recording. A de- velopment of the broadcasting micro- phone (B) and the telephone transmitter (A), indicating how “Sound Pictures came out of the telephone.” System. This apparatus, made by the mak- ers of your telephone, is installed and in- spected by engineers trained in this new art. The reliable quality of this Sound System has been recognized by over 2,000 theatre exhibitors — exhibitors who have a habit and who therefore believe that it is worth satisfaction

Western Electric’s experience with this very problem which, after years of unsuc- cessful effort by others, finally made Sound Pictures possible. This same organization which brought the telephone to its present excellence will likewise constantly seek to improve Sound Picture apparatus still further. a little extra investment to secure equipment of proved results. In selecting Western Electric these exhibitors knew that the correct transmission and repro- duction of sound is an extremely difficult prob- lem, as is evidenced by the wide differences in quality between various radios and phonographs. They knew that it was Jeciric SYSTEM

The loud - speaking horn (C), a marked improvement for Sound Picture pur- poses over the cone loudspeaker (B). It is a direct descendant of the familiar telephone receiver (A), and is made with the same care.

Page 10

TR ite Stee a ote bon A at LR TT SE pai site was Dota heaatatinee — 8 POPULAR SCIENCE MONTHLY AucGust, 1929 Guaranteed Advertisement Automobiles and Accessories Page Smoking Materials Page Radio Apparatus Page EES EES SS Chesterfield Cigarettes..................-. 94-95 Carter Radio Company................... 125 mpion Spark Plug Co...............-. ne hove, eee 6 Ceco Manufacturing Co.,Inc............. 125 | OPS eee CG Hikak 0 csavaevisaneen soe Back Cover Day-Fan ElectricCo..................... 9 i ing Corporation........... I aig écdran5'o Bre 6: kis: 4-» sere arama 125 Sturlebake Corporation of America, The. . National Carbon Co., Inc................. 89 een of America............ 85 Razors, Toilet Ar ticles, Etc. a EY 55. -40a'e a5 ecohol ais mire wamagiee 125 Building Materials ices cinmunon 117 Gillete Safety ee ot Seer 11 Aviation Celotex Company, The................+:: m rmacal Company............. 15 Masonite Corposstion. Seecenl a Siaedeess peaee Company, Es...........---+.--. a3 a ea aren a Procter & Gamble..................ceeee 122 American School of Aviation.............. 130-141 eS eee 134 Dayton School cf Aviation, The........... 140 Books ag a ~ ae Raeare eesds seniad 101 ° ‘on i | ere Educational secs aie na 105 Haldeman-Julius Co... ..7.........-.50%- Science News-Letter .............ecsceees yan Sehect, Berea as + 3080 <8 141 erican ool o otography.......... 130 * Bites Miectrical Gchool...............2000. 130 Sporting Goods Pot oe y= ts S pipedaananaieiass 130 ene ne 132 P Things to Make Coyne Electrical School” ................ BE ~~ ~apappmnnaeneeate 123 Detroit School of Lettering............... 131-141 PORE SURE Bint se +s nc sscssccccccoees 118 Finlay Engineering College................ 130 Harley Davidson Motor Co............... 115 American Chime Clock Co..............-- III, 5 cig Sie a Bhs. cle -0-4ia 0-0-0. 050 130-137 Mead Cycle Co.....-.... 0.6.2 seer eens 123 eee ss OO ee ee eee International Correspondence Schoo Ohio eat Supply | OR: I RO 120 Ideal Aeroplane & Supply Co., Inc......... 0 12m SS. 132-136-142 Oe rere 123 heh gigkeccsess reduces Miniature Ship Models, Inc............... Detteretee, Miemry Cox ccc ciccccnccoce Industrial Equipment oO l 4 Norton Company.................. Third Cover Investments Popular Science South Bend Lathe Worlks 000001... 120 aylor Instrument Companies............ 10 Cochran & McCluer Co...............45. 5 G U A R A N T E E bo ee rer errr re 121 Fidelity Bond & Mortgage Co............. 5 Smith Company, The F.H............... 4 Smith, Reed & Jones, Inc................. 5 © Patent Attorneys POPULAR SCIENCE Tools and Shop Equipment MONTHLY guarantees every Coleman, Watson E....................5. 137 article of merchandise adver- Dieterich, Albert E Wickes, Neeeteoreers 137 tised in its columns. Readers vans Gmpeay, Victor J... .......6.. 133 TI CO o.oo oc scence cedccecceee - Fisher Mfe. of * RCO Atkias & Company, E.C................. who buy products advertised oe nba ects, Adam hearer es eae = ce 8 ST Es The.......-++++-++ in POPULAR SCIENCE ee eee 137 Boice, W. B. & J. E............--. ese eees Lancaster & Allwine...................:. 139 Brown & Sharpe Mfg. Co................. MONTHLY may expect them teen, irieeh.......... 139 Clayton & Lambert Manufacturing Co..... to give absolute satisfaction Munn & Company er ee 137 Delta Specialty Company................. under normal and proper use. O’Brien, Clarence A...............0.000. 135 = & — ev: bes asicapan ss Tools, Radio Apparatus, Oil Randolph & Company..................4. 139 Foley Saw Tocl Co., Inc.................. Burners and Refrigerators ad- Gerstner & Sons, H...................... vertised in POPULAR SCIENCE Heston S sy wee mes siert macmenre Pare sed oe + MONTHLY have been tested or : a... investigated by the Popular Musical Instruments Parks Woodworking Machine Co., The..... Science Institute of Standards a on — Co, Ths: ..--.....-- and each advertisement carries Buescher Band Instrument Co............ 123 Porter-Cable Machine Co., The........... the insignia indicating ap- ME cs sy cases cesnesccs xs 120 q Simonds = NM, oc ccreasbncnecass proce . , EE Th Scb a lesaetcscesecease owever, other pro ucts ! Stanley Rule & Level Plant, The... 000 advertised in the magazine \ Scott-Bansbach Machinery Co............ not subject to test carry the Business Opportunities { ' Waco Tool Works, CLR cod Kheeee ae oe same guarantee to readers as Hi | products tested. A | American Buajnce Dulldere adel dia Rat eae i: |! Blue Ribbon Gum Co., Inc................ | General THE PUBLISHERS Central States Manufacturing Ge... 128 i | ME. cc cis cast tcctsssinaas '126-127- 128 i | Eakins Co. bene Gidh a tibet Sed erdad Sagrani ale an ingh EE ee ee a Western os oy gla nt sce —— oy Metallic Letter Co..............0.0.00055 131 Al | . | Sereno es BN ei livn igstcord ace Mecdeceat an pe i | Landon School, The.....4.........00..05. 1390 Spencer Mead Co...................-.--. | La Salle Extension University. i.) Cees: 131-141 EE BI, GO, so Wins so cds vise ce 00.c08 122 {4 rrie ool of Mechanical Dentistry .. 41 Hh Watches and Jewelry McSweeney Elec. School............... et i aes are # Seporion.. - VaR * a 139 } ” ational Electrical School................ 139 ‘ i Studebaker Watch Company.............. National Radio Institute... .... 131 Miscellaneous if New York Electrical School, The.......... 131 if New York Institute of r Photography aoe. 137 _ if Page-Davis Sch. of Ad Lae {tp ae 131 Apparatus Engineering Co................ 121 MW Hardware Supplies Radio Institute of Aeceniin oe i a See «Me MONE GG. ..o... 6 iis cc ccccees 137 School of Engineering of Milwaukee ....... 138 Baby Calculator Sales Co................. 143 Standard Business Training Institute...... 130 += Bauer & Black....... EIS ea ok ors Se 114 itn Gs. ic cteceeceescectc = 2... pees 131 Bureau of Inventive Science............... 136 atte Weed.......... , piss hennene ae A eee Oe 140 Plymouth Rock SquabCo............... 120 oc cwidedenduleasebep« 108 Universal Plumbing School................ 130 Wetherill’s Specialties, Dr................ 120

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Page 11

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ae Aucust, 1929 POPULAR SCIENCE MONTHLY 9 Medan ..in selecting radio...look for ENGINEERING

Directly above is the 9-tube Day-Fan Radio in a new and par- ticularly pleasing small Console of walnut. With specially match- ed Dynamic speaker, complete except tubes, $169.50. At upper right, the deluxe Con- sole, a cabinet of rare beauty, con- structed of walnut with matched burl panels. Sliding doors: With specially matched Dynamic Speak- er, complete except tubes, $225.00.

Here’s a Champion of quality in construction What’s the real difference between ordinarily good radio and excellent radio today? You’ve got to go deeper than the looks of the cabinet to find out. The difference lies in features of electrical and mechanical design—finer workmanship— better materials: expert engineering. These things are not spectacular, but they contribute directly to the set’s performance and stability. Day-Fan, in order to achieve a new and de- lightful brilliance of tone, improved selec- tivity, increased power and amazing volume without distortion—is spending more money in the manufacture of its chassis than ever. (And yet we have reduced the prices of the sets.) Day-Fan has always been noted for super-

iority in its audio amplification system, which directly affects the quality of tone. To this superiority there have now been added further improvements. Two of the new highly efficient UX-245 Power tubes (D, qhuvat are used in push-pull amplification. They deliver great undistorted output to the speaker. Each pees of the amp- lifier, including the agrees esigned dynamic speaker, is carefully matched in impedances, one with another. This is responsible for full flow of undistorted power, preserving the beauty of tone. Throughout, the new Day-Fan set is dis- tinguished from average receivers by greater amounts of material, closer limits nm manu- facture, careful matching of units, and pains- taking adjustment of the whole set. Variable tuning condenser (L) is large and rugged. In transformers, coils, chokes, condensers and other hidden parts, the standard is “only the best”, with each unit ample in size for its work. - No wonder Popular Science Institute of Standards, scientifically testing radio perform- ance, confers on Day-Fan Radio its unquali- fied approval. ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee -=— Day-Fan Electric Co., 1708 Wisconsin Blvd., Dayton, Ohio Please mail me descriptive literature on Day-Fan Radio. i Tell me where I can hear demonstration. FULL-POWER-: TU B E : UTILIZING EE ARDIGD | Peer rere rr rr reer r rr rrrrrrrrr err Ceres eee ee ee eee eee

Perr rrr rrr rrr errr reer rr eee Pere Terr Tee eee eee eee ee eee PPOUPPREPUUCEUEPOEESOE POSE U CCCP SET eee eee

Page 12

a Ne — a ee i POPULAR SCIENCE MONTHLY Aucust, 1929 ARE YOU STILL PLAYING “BLIND MAN’S BUFF” FOR YEARS... ONE OF THE LARGEST COLD STORAGE PLANTS IN CHICAGO ... DE- PENDED ON THE ENGINEER’S SENSE OF TOUCH OR FEEL— =BLIND MAN'S. BUFFi—TO DE- TERMINE THE “RIGHT” TEMPER- ATURE FOR AMMONIA GAS ‘Tycos TEMPERATURE /JCONTROL INSTRUMENTS Science has developed heat treating for metal-baking processes for finish. ing and innumerable other processes in industry in which temperature con- trol is not only an essential part but in many instances the foundation. Tycos in cAniation A. full line of Aviation Instruments for ships and air ports. Trcos for the Home Bros Office Thermometers A\n aid in promoting human efficiency. Tyeos Bath Thermometers Treoe Home Set Bake Oven Thermometer, Candy Thermom- ever, Sugar Meter. The secret of accurate results in cooking. Foose Wall Thermometers To help you to mai a Pp ure in your house conducive to good health. Fece Quality Compasses Boos Fever Thermometers Trove Stormoguide Forecasts the weather twenty-four hours ahead with dependable accuracy. Temperature controlling instruments are a prime necessity in Industry to- day. JZycos Temperature Indicating, Recording and Controlling Instruments are recognized as the “Standard” equip- ment in America’s largest plants. Tae Mipews EEE Pe Cheap instruments are no further re- euaghent = your pepe he moved from “Blind Man's Buff” than is the human element of engineer’s touch. X for the Medical Pro fession Jrcos Instruments are “Accurate”—and built to deliver enduring satisfactory LveOs operation with minimum maintenance. oe Sphygr » Recording Pocket and Office types. Don't play Blind Man’s Buff—install the recognized Bone Fever Thermometers. “Standard” Tyeos Instruments. Your dealer will show them to you. Ask us, on a postal, for booklets on any of the above. IN EVERY INDUSTRY — Scce Temperature Instruments are the “Watch Dogs”’ P of maintained quality. In many instances they are the basis of manufacturing Bulletins on request processes—and they Gauge deliver the goods. roummurcronens, ee ercneetes tee arylor Instrument Companies preparation there are undoubtedly Secs Instruments for Indicating, Recording or Controlling heat that will save Main Office and Factory money for you in your plant and give you the assurance of the STE a - uniform quality you are always striving for. ROCHE R, N.Y. U.S. A. Informative literature on any type of instrument will be sent Canadian Plant: Secs BUILDING, TORONTO you promptly on request, or our engineer will consult with ' SHORT & MASON, Ltd you on the application of Jee to your particular manufac- » Ltd. turing problem. Manufacturing Distributors in Gréat Britain Rept mec cnieniiidiaaiaiciiiatienditi HE ~ SIXTH ~ SENSE ~ OF~ INDUSTRY cos Temperature [Instruments INDICATING - RECORDING ~ CONTROLLING ah naire vo ReeE

Page 13

sete aL a RR Aueust, 1929 Ava} Jrom Home Here you are in your own bathroom, A place for everything, and every- thing in its place. Hot wateralways, a good mirror, and a fresh package of Gillette Blades on the shelf. Then it’s easy to get your full measure of comfort. POPULAR SCIENCE MONTHLY ll Achilly morning in the mountains. And a mirror from your shaving kit tacked to a tree. A wind-burnt, sun-burnt face with perhaps a two- day beard. Then it’s pleasant to re- member that you tookalong a fresh pack of Gillette Blades for comfort. ... you can’t expect as smooth a shave WHETHER you shave quietly and luxuriously at home; or strenuously, over the shoulders of other harassed travelers in a Pullman wash- room; or primitively in camp, with the cold lake for your wash basin—no matter how different the shaving condi- tions may be—put a fresh Gil- lette Blade in your holder and you're sure of a smooth, com- fortable shave. Your guarantee of this unchanging comfort is thecareful honing, the del- icate stropping that Gillette’s mar- velous machines give every blade. No human hand, however expert, however patient or tireless, could But you can count on your Gillette Blade to give you a comfortable shave anywhere ever work such comfort into a blade. And Gillette goes one step further. It sets aside almost half of all its blade department workers to do nothing but inspect your blades— Tu E only individ- ual in history, ancient or modern, whose picture and signature are found ineverycity and town, in every country in the world, is King C. Gillette. This picture and Signature are univer- sal sign-language for a perfect shave, and rewards with a bonus the end- less search for any blade that may be below par. You see, eight out of ten men in America shave with a Gillette and expect every Gillette Blade to do its duty. So every blade has to be good, no matter how difficult the condi- tions it goes up against—hard water, cold water, tough beards, tender skins, slapdash lather—a dozen vary- ing conditions that affect the com- fort of your shave. Conditions change —the blade doesn’t. That’s why you can always slip a fresh Gillette Blade in your razor and enjoy a swift, sure shave wherever you are. Gillette Safety Razor Co., Boston, U. S. A. Gillette

Page 14

POPULAR SCIENCE MONTHLY Aucust, 192) What Insulation Really Does

House at right is insulated; the other isn’t. See how escaping heat has melted snow on roof. EN is a house really insu- lated? Just what will the in- sulation do? These are points on which there is considerable confusion among people who are building or buying a home. Very frequently they think they are getting an insulated dwelling when, as a matter of fact, they are not. Still more frequently, they know nothing at all about insulation and éntirely overlook this very important feature. By including a sufficiently thick layer of one of the standard insulating ma- terials in the roof and walls of a house, it will bring down fuel costs about one third, make possible the use of a con- siderably smaller heating system, afford uniforma room temperature with elimina- tion of drafts, and keep upstairs rooms ten to fifteen degrees cooler than outside temperature in summer. This is too good a thing to be ignored by the up-to-date builder, and Popular Science Institute, in line with its policy of promoting the use of efficient and modern methods in house construction, aims to increase the knowledge of, and use of, insulation. Ce het on few people really know the facts about “ser tion. A letter that shows how easy it is for many ple to be misled on the matter of insu- fation came from one of our readers the other day. This reader is building a home and is much concerned about Securing good construction. To his letter he adds this postscript: “P. S. Builder claims that house has been completely insulated by the use of two thicknesses of building paper under clapboards and shingles.” His builder was probably honest, but not very up-to-date. The type of con- struction described was considered at one time “insulation,” but today there are materials on the market only a half inch thick that are as effective as ninety-five layers of building paper in stopping heat leakage. So this reader’s two thicknesses of building paper will not afford much insulation, as measured by modern stand-

< es « AG wm The Right Materials Cut a8 = Fuel Bills in Winter and Keep You Cool in Summer By COLLINS P. BLISS Director, Popular Science Institute

readily as through a half inch of good insulating material. An air space in the construction of walls or roof should not be expected to af- ford sufficient insulation in itself, though air spaces are to be taken advantage of when possible in the application of insulating material. O GET real insulation, it is necessary that the roof and walls of a house contain a standard insu- lating material in a thickness recom- mended by the manufacturer. There are now a number of good insulat- ing materials on the market in vari- ous forms from which the builder may choose. Samples may be seen at local building supply firms and a selection made of a material most

Applying insulating material of the felt type to the ceiling of a room—for saving and year-round comfort. ards. Building paper, however, does have a very definite place in good house con- struction. It stops air leakage, though it does not take the place of an insulator which stops heat leakage. Building paper should be considered merely as a desirable addition to insulation and not a substi- tute. Another material that used to be con- sidered a good insulator was suitable for the purpose. In making a choice, consider the cost of the in- sulation itself in the proper thick- ness, the cost of having it applied, and how well it suits structural requirements. A booklet, “Insulation in Building Construction,” can be obtained from Popular Science Institute at twenty-five cents a copy. In sending for this, or ask- ing any special questions, address: Popular Science Institute, 250 Fourth Ave., New York, N. Y.

back plaster, but the way in which this really served was as a wind-stopper. A material that is merely air-tight is not enough; rubber coats and window glass, for example, are useful wind- stoppers but let heat go through quite readily. There are still a number of people—even architects and building contractors—who be- lieve air spaces to be highly ef- fective in preventing heat loss. Scientific investigations con- ducted by authorities have definitely proved, however, that the value of air spaces as insula- tion is slight and that air spaces greater than three quarters of an inch in width give no additional value for heat insulating pur- poses. Heat will go through an

and SERVICE AIDS FOR READERS Insulation in Building Construc- List of Approved Radio Prod- What the Radio Buyer Should List of Approved Tools List of Approved Oil Heating Advice on Installing Oil Heat List of Approved Refrigerators Refrigeration for the Home* INSTITUTE BULLETINS tion* ucts Know* Devices *Price 25 cents each

air space about three times as

a tee ees

Page 15

Avoeust, 1929 POPULAR SCIENCE MONTHLY From dance hall floors to railway coach ceilings ..this grainless wood board Beauty, such as paneled ceilings need, is usually required to sell a product. Dura- bility, that a floor must have, is necessary to keep it sold. Manufacturers who adopt Masonite Presdwood find that it gives their products both durability and beauty. Samples for testing will be gladly supplied. In a Denver dancing academy the tap-tap-a-tap of metal tipped clogs resounds from a floor of Masonite Presdwood. At Pull- man, Illinois, ceilings of Presd- wood are applied to railway FOR DANCE e . HALL FLOORS coaches. And in scores of widely varying industries, hundreds of products are be- ing made better and at lower cost because of this grainless wood. Many of these Presdwood products require the strength and durability that are indicated in the service rendered at Denver. Used eight hours a day at the Fred Merritt School of Tap Dancing, the Presdwood floor showed no signs of wear, even after weeks and weeks of usage. Other Presdwood products may require smoothness and ease of finishing — there, again, Presdwood is ideal, as evidenced by its use for paneling .. . not only in ceilings of railway coaches but in fine homes and buildings as well. Is easily cut Beauty and lasting qualities are but a part of the advantages of Masonite Presdwood. It is mois- ture resisting and almost immune from warping, shrinking and buckling. It is extremely easy FOR BREAKFAST NOOKS pea | ae = a var Fe SSS a I SPN an IS 2S oe oe sO ‘ (| doe PRESDWOOD ||) i) || a MASONITE STRUCTURAL INSULATION to work with. It can be sawed, punched, planed, milled or sanded. It is liked by shop fore- men, experienced with mate- rials of all kinds, and is just as welcome in homes where handy . ° FOR RAILWAY men put up shelving or build a — coacu cetine radio cabinet. Wherever it is used it never harms fine tools, for it contains no artificial binder. Has wide range of uses The uses of Presdwood are many and varied. They range from bedroom screens to toys, from motor truck bodies to hydroplane hulls, from bread boxes to loud speaker tension boards, from out-door signs to kitchen cabinets, from office par- titions to billiard tables, from clothes hampers to breakfast nooks. Fully eighty of Presdwood’s many uses, in in- dustry and the home, are listed in the Presdwood booklet which is gladly sent to those who appre- ciate the beauties of fine materials or who wish to effect manufacturing economies with this work- ° able grainless wood. MASONITE CORPORATION Dept. 728, 111 West Washington Street Chicago, Illinois FOR PANELING = PISO) ING? —>. a 61929 M.c.

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Pa a a a 14 POPULAR SCIENCE MONTHLY Ow Readuy Aucust, 1929 ae eae Calm Yourself, Mac “ 4 SPECTACLE indeed—Poputar Science MonTHLy attempting to revive old John D. Rockefeller and make him over into a guardian angel of science! In one issue I read a rather convincing article on the Rockefeller Institute for Medical Re- search. But in the very next issue along comes an article on ‘What John D. Rockefeller Has Done for Me,’ picturing him as ‘the greatest benefactor of science who ever lived.’ What’s the idea? “TI see- where the Power Trust has been exposed buying control of American newspapers. Can it be that Poputar Science has fallen for the glitter of some of John D.’s bright new dimes? Or what? ; ae “The picture of Harry Sinclair soaking in jail while pious old John D. steps into the pages of Poputar ScrENCE as ‘a tremendous and vital force in the advance of science’ is really too touching to contemplate. apy “Oil seems to have a way of spreading itself in devious and wondrous ways.”—S. MacL. Seattle, Wash. What—More Bills? “ (\NE good argument Mr. Eastman missed in advocating the proposed thirteen- month calendar is that we won't need to be bothered any more with those beautifully adorned calendars sent out each year by the coal man and the life insurance agent.””— S. L. F., Springfield, Til. “Why didn’t George Eastman mention the fact that there would then be thirteen rent bills, gas, electric, and installment bills, with but twenty-six pay days, as usual, per year?”’— L. N. E., Racine, Wis. See Page 21 for Answer to This Mystery “yN ONE of your recent issues, John F. O’Ryan says that nonexplosive fuel will replace gasoline for aviation. Of what use is a fuel if it will not explode? The explosions in the motor are what make it go.”’—H. L. A., Pitcairn, Pa. Maybe They’re Dry Flies “(\NE of your recent articles contained the statement: ‘Watch a ene fly which has been sub- j merged in water. It can- not fly until it has dried gi > ~ off.’ A few minutes ago I = Zz zy submerged two common 7 house flies (nursa domes- = tica) in water, releasing them six inches below the surface. Both rose to the surface of the water and immediately flew away. Many-in- sects will do this—those with wings to which water does not adhere.”"—C. L. N., Raleigh, North Carolina. Thanks—It’ll Be Out Soon ” I WOULD like to know whether your most interesting series of articles, ‘The Real Fathers of Flight,’ will appear in book form. I have read every installment in Popunar Scrence Monruty and enjoy it greatly. The illustrations and the story are so interesting that I should think that the book would seH to the general public. If you haven't con- sidered this before I hope you will give it serious - consideration now.’—C. M., New York City. Who Can Settle It? “ AN EDITORIAL iin your July number implies without directly saying so that the wheel is the most important in- vention. I had thought that the question was set- tled years ago. The al- phabet is the world’s most important invention for reasons that are too obvious for me to = Think it over.”"—B. L. M., New Haven, onn. This Is Certainly Tough “T AM truly glad that Mr. R. L., Ph.D., of Bismarck, N. D., has joined the few who ‘understand Einstein. But i wish he would tell me and the rest of your readers something. If this old world jumps up to meet us to keep us from falling and getting hurt when we step off of a tower or high steeple, or if it is going up our way, what is it doing to them poor Chinamen on the opposite side from us? The earth can’t jump two ways at the same time, so if that poor Chinaman happens to step off of a high tower at the same time one of us does, that poor fellow is left out in space, and where will he go?”’— F. C. C. C., Flint, Tex. The Kind We Like to Get ? you may be interested to learn from an old reader of PopuLak ScteENcE MOonTHLY that he considers the series of pencil sketches of inventors and engineers which you are now running one of the best things you have done in a long time. “The ones of Edison, De Forest, and Hoover I have had framed for the walls of my study, and trust that there will be several more to follow which I can have framed in the same style and add to my collection. “I would also like to add a word of praise for the artist, Mr. Rosenmeyer, who, it seems to me, has a wonderful ability to put on paper the spirit of his subjects. May he be able to give us many more drawings equal to the four or five that have appeared. “‘As to the magazine in general, I can only say that it is the most interesting paper that I read. While I receive, and read more or less, many technical and scientific publica- tions, I find Poputar Scitence Monrtuay holds my attention from cover to cover, due to the human interest quality of its contents, which is entirely lacking in so much scientific litera- ture.”’—L. S. M., Hartford, Conn. “I have read your magazine since last No- vember, and I think it one of the finest I ever read. I call it a ‘Storehouse of Knowledge,’ clean and wholesome in every sense of the word, and my wish to you is long may you grow and pros- per.” —J. A. H., Louisville, O His Favorite Authors “PLEASE don’t let Bunch and Koch, Edward Thatcher, or Captain McCann stop writing articles for PopuLar ScrENcE, as they have made the Home Workshop De- partment of the magazine second to none.” — T. P. G., Charlotte, N. C. “I am very much interested in your Home Workshop Department and have found some very good projects to make, for which I am grateful to you.” —A. H., Milwaukee, Wis. Answering O. T. K. “O T. K., of Poughkeepsie, N. Y., wonders * why Poputar ScreNcE prints such an ‘insidiously harmful’ set of articles as ‘I Am Learning to Be a Flyer.’ O. T. K. is certainly ignorant of airplanes and aviation. There is more study, work, and responsibility in avia- tion than any other occupation.’”’—A. E. T., West Hartford, Conn. “T can’t help but feel that O. T. K. has at some time tried to pass the test for air pilot and was rejected.”’—J. F. C., Indianapolis, Ind. “Of course, O. T. K. is right in some things. Aviation was not made in a minute, and it takes study and hard work to make a success- ful pilot.’ —G. R. M., Washington, Pa. “The chief criticism of O. T. K. seems to be that you have pictured aviation as a career in too rosy hues. In my estimation that is im- possible to do.” —D. K. D., Helper, Utah. “The comment of O. T. K. is well founded, although I do not agree with it entirely. I personally have found Larry Brent's articles very interesting, but they should not be per- mitted to become the factor in deciding one’s life vocation.” —J. C., Brooklyn, N. Y. “O. T. K. is all wet.”—W. R. McP., San Leandro, Calif. Who Knows Another One? ? R. KARL P. SCHMIDT states in his article on snake stories that snakes do not milk cows. Maybe Mr. Schmidt isn’t fully acquainted with the habits of all of our Florida snakes. Unfortunately, we have a snake that is known as the gopher snake. It won’t milk a cow every time it sees one, but will do it now and then. “This snake is of a steel- blue color, grows to a length of eight feet, sometimes having a diameter of three and a half inches at the thickest part, is not poison- ous, and puffs or blows at anyone who comes too close, like an old turkey hen. It is usually discovered in damp parts of the country. It feeds on rats. **At one time my father had about fifteen cows. For two or three afternoons in succes- sion one of them would come out of the pasture with no milk in her udder. We blamed the loss of milk on a neighbor. On a succeeding afternoon I watched the cows from behind brush and trees and caught a gopher snake, red-handed, getting his afternoon tea.”’— H. R. H., Jupiter, Fla. Au ‘sages = SS — a

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Aueust, 1929 Snubbed into solitaire Here is a man of charm and distinction who loves bridge and plays it like a master. Yet were you to follow him to Palm Beach in the winter or to New- port in the summer, you would usually find him playing solitaire — certainly not from choice— but actually snubbed 4 ew. mt aon POPULAR SCIENCE MONTHLY into it by those of his own set. He is the fourth nobody wants. And he doesn’t know why. If you have ever met a person with a real case of halitosis (bad breath) you can readily understand what a barrier to social or business success it would be. Imagine yourself in such a pre- dicament. As a matter of fact, the probabilities are that you do have halitosis frequently. Few escape it for the reason that every day, in normal mouths, odor-producing conditions (many of germ origin) de- velop. So, thousands have halitosis and are unable to detect it. Since the risk is great and detection difficult, the wise thing to do is to defi- ~ nitely put your breath beyond suspicion GREAT! That’s what men say about Listerine Shaving Cream. So soothing, so refreshing. by the daily use of full strength Listerine as a mouth wash and gargle. It both prevents halitosis and ends it, should it get the upper hand. While safe and pleasant in action, full strength Listerine is a powerful germicide which kills even the stubborn Staphylococcus Aureus (pus) germ in 15 seconds. Naturally, it destroys lesser germs in the mouth. Furthermore, it’s an active deodorant which overcomes odors of all kinds, No fastidious person will omit the use of Listerine daily. Lambert Phar- macal Company, St. Louis, Mo., U.S. A. LISTERINE THE SAFE ANTISEPTIC

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a a sa 2 -_ RLS ‘ a _ cers, eee & WITH CELOTEX 1 CAN TRANSFORM Your ATTIC INTO A COOL, LIVABLE For cooler homes in summer, warmer homes in winter and less fuel waste... Dusstshata at the roofline... ODERN home owners insist on AL Celotex for repair and remodel work because it insulates as well as builds . . . keeps your home at an even temperature throughall seasons and changes in weather. Celotex insulated roofs resist the pass- age of scorching sun’s rays . . . retard furnace-heat-leakage . . . help keep out penetrating dampness and chill. With the roof insulated with Celotex, you can use the attic for extra living space, for bedrooms, playroom, workshop or den. Attic rooms protected by Celotex are always cozy and healthful. Celotex is the only insulation made from the long, tough fibres of cane. It comes in big, strong boards, 4 feet wide, 7 to 12 feet long and 7/16 of an inch thick. Also made “double-thick” — 7% inch. When used on the outside of houses, as sheathing, Celotex adds structural strength .. . makes walls tighter and more permanent. And on inside walls and ceilings, you can obtain finer, smoother plastered surfaces with Celotex Lath. This new lath, 18 inches by 48 inches and 7/16 of an inch thick (also made “double- thick” — 7 inch), is especially designed to reinforce against plaster cracks and to eliminate disfiguring lath marks. =z Be sure it’s Cane Fibre Insulation ! Only Celotex is made from the long, tough fibres of cane. The peculiar advantages of cane fibre insuiai n cannot be obtained in any other material. Be sure you get CELOTEX! Ask your architect, builder or dealer for further information on Celotex—and write to us for our free booklet, “Year "Round Comfort and Fuel Saving for Every Home.” The Celotex Company, Chicago, Illi- nois. In Canada: Alexander Murray & Co., Ltd., Montreal. Sales distributors throughout the world. All reliable deal ers can supply Celotex Standard Build- ing Board and Celotex Lath. The word CELOTEX (Reg. U. 8. Pat. Of.) fe the trademark of and indicates ™ie ae” CELOTEX BRAND INSULATING CANE BOARD When you buy a new house, look for the Celotex sign. Itis your assurance of greater home comfort Aucust, 1929 Red ERR Cel in i oa 2 & ch oo Of tet © _—_— ~— eee a wet == --

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Se 1 OO PORN 96. 1S eS eee Gcmialind MI mt Um AWN | | AUGUST, 1929 SUMNER BLOSSOM Editor VOL. I1§, NO. 2 — “Reg’’ Robbins (left) and “‘ Jim’’ Kelly, with Mrs. Robbins and Mrs. Kelly, after record duration flight in the Fort Worth, above. OLD but graceful single- motored Ryan brougham mono- plane swooped down toa perfect “three-point” landing at the Meacham municipal airport at Fort Worth, Tex., one Sunday afternoon a few weeks ago. Cheering wildly, 60,000 men and women who had been waiting to see it touch the earth broke through ropes and a cordon of police, overran the muddy field, and engulfed the little silver sky-ship. Deadly tired, covered with grime, but grinning behind eight days’ growth of rd, two young men clambered stiffly out of the cabin and were almost crushed by their excited fellow citizens. One of them, James Kelly, just twenty- three years old, was an ex-cowboy with little flying experience. The other, Reg- inald L. Robbins, three years his senior, was a former railroad mechanic who had never had a flying lesson in his life. These two semiamateurs had finished the longest sustained flight ever accom- plished. With only each other for com- pany, they had flown night and day for 172 hours, thirty-two minutes, and one second—four and a half hours more than a week! They had shattered the refueling endurance record established a few months previously by the Question Mark, the three-motored, $100,000 U. S. Army plane, manned by five experts and backed by the Government’s mechanical and sci- entific resources, by twenty-one hours, fifty-one minutes, and forty-six seconds— nearly a full day! And they had achieved that amazing feat in a reconditioned airplane, chris- tened the Fort Worth, that already had flown a total of 50,000 miles—equal to twice the circumference of the earth— and that was equipped wittl a Wright Whirlwind motor which had been bought secondhand two years previously and had run for 500 hours since. Moreover, they had never refueled a plane until A Dramatic Story of an Eight-Day Spectacle —How a Junk Plane Was Kept in the Air More Than a Week By MICHEL MOK. their flight was actually under way, and had practiced the making of contact, without transfer of gas, only three times on the day before taking off. Not only had they staged a dramatic eight-day spectacle, but by demonstrat- ing the endurance and airworthiness of a single-motored ship and the feasibility of refueling over a long period, they had made a definite contribution to the prog- ress of aviation. RILLIANT as it was, their accom- plishment did not stand alone. It was the most spectacular of an astonish- ing series of aerial feats, which followed in quick succession. Within three days from the descent of the Fort Worth, a new altitude mark was hung up by a German flyer who climbed almost eight miles, a new speed mark was set by two French army pilots, and the United States wit- nessed a new solo endurance record, a new altitude record for light planes, a new seaplane speed record, and a new alti- tude record for women! 17

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18 When the Fort Worth landed, Kelly and Robbins scarcely had time to stretch their legs after climbing out of the cramped quarters-in which they had traveled 12,900 miles before they were bombarded with questions. **How do you feel?”’ Robbins was asked. The chief pilot of the monoplane was slightly deaf from the constant droning of his faithful motor, and the question had to be repeated. “Ob!” he said, rub- bing his chin. “Right now I feel like having a shave!” ‘HAT was the hardest part of the flight?” someone asked Kelly. The former cow- puncher chuckled. “Keeping ‘Reg’ (Rob- bins) awake long enough to pilot the ship,” he replied in his Texas draw], “‘so I could snatch a little sleep!” These answers epitomized the characters and dispositions of the unassuming men who had given an exhibition of courage and cool- headed skill rare even among air- men. Twice, at least, death had grazed the wings of their rebuilt plane as they were wheeling about endlessly half a mile or more above the airport, but it had failed to break their dogged determination to finish history’s longest excur- sion in the air. And through danger, discomfort, and sickness, their sense of humor did not desert them for a moment. That same “Jim” Kelly, riding the plane like an aerial broncho buster on the second day of the marathon, came within an inch of being cut to ribbons or hurled to the ground from a height of some 2,500 feet! Perched on an eight-inch catwalk along which he had to crawl twice each day to grease the rocker arms of the en- gine, the buckle of his safety belt nicked the propeller. One glancing blow from the blade, whirling 1,300 revolutions a minute, and the cowboy never would have made another flight, uttered an- other joke, nor seen the girl he had married just six weeks before! a A note dropped by Robbins that day, not a word was said about Kelly’s narrow es- cape from death. The chief pilot, in his message, merely complained of a slight attack of air-sick- ness. Nor did it become known until after the pair were safely back to earth that it was this same mis- hap to the propeller that finally forced the Fort Worth. down to earth. The tiny crack in the wooden blade began to widen. during a heavy rain the flyers encountered on the Friday night before their descent, resulting in an ominous vibration. At One of seventeen refueling contacts dur- ing the Fort Worth’s flight. Above is K. K. Hoffman, pilot of the refueling plane Midland. At right: H. S. Jones, who handled job of lowering gas hose. POPULAR SCIENCE MONTHLY the same time, they saw that the fabric of the wings was beginning to fray under the impact of wind and rain following the steady grind of continuous flying. But by the following evening the endurance record of the Question Mark would be topped by the one required hour. Rob- bins and Kelly set their jaws, and kept on. They made it! That Satur- day night, with victory theirs, you might have thought they would have “‘called it a week” and glided down to safety. But they did nothing of the sort. They were determined to remain in the air 200 and, if possible, 300 hours! “We plan to stay up until she falls apart,’ Robbins, the self-taught flyer, had said when they took off in their secondhand plane. He kept his word. At midnight, the Fort Worth ran into a severe electrical storm. Kelly was at the controls when it broke. A terrific crash of thunder awoke Robbins, who had been asleep for about an hour. He took the controls. Drenching rain, mixed with heavy hailstones, beat upon the frazzling wing fabric. The gash in the propeller was widening constantly. This they knew because the motor vibration increased by the minute. Dazzling streaks of lightning shot from black clouds. Then a blinding flash! The The crowd rushing out to meet the Fort Worth as it landed at Meacham municipal airport, Fort Worth, Tex., at the end of the record flight of more than a week in the air. AucustT, 1929 pilots looked into each other's faces, “Are we struck?” asked Kelly. “Almost,” said Robbins. Through a forty-mile gale, through rain and hail, amid deafening peals of thunder, the former railroad mechanic piloted the Fort Worth to safety. NCE out of the storm, he “hugged” Meacham Field for the rest of the night. When daylight came on Sunday morning, the flyers decided to try keeping the plane aloft until 11:33, when an en- tire week would have elapsed since they hopped off. Again, they made it! But still, they were not satisfied. It then occurred to them to stay up until after- noon to give as many of their fellow citizens as possible a chance to see the Fort Worth land. Running the risk of crashing with a shattered propeller, they kept on winging until 4:05 p.m. Robbins had made good his promise. Had they re- mained in the air longer, the pro- peller undoubtedly would have flown to bits and the plane liter- ally would have “fallen apart”’! When the flight began Rob- bins, who had never attended a flying school, had had about six years of expe- rience as a commercial flyer and a “barnstorm- er.” With his savings, he had bought the old Ryan monoplane, the despair of everybody ex- cept himself. He con- sented to have the ship rebuilt but refused to have the motor touched. “T can coax it better if it’s left the way it is,” he said. ELLY, who had been a cowpuncher since he was a lad, had the advantage of formal flying instruction, but he was a greenhorn at the game. He had finished his course less than two months before he stepped into the cabin of the Fort Worth! With 250 gallons of gasoline aboard, the secondhand Ryan took to the air at 11:33 on a Sunday morning. Except for Kelly’s “‘close cail’” on Monday morn- ing, and Robbins’ attack of air-sickness, all went well during the first five days. Refueling took place regularly three times a day, except on one day when the reserve supply of gasoline was so large that once was enough. In all, seventeen refueling contacts were made suc- cessfully. The last, early on the final Sunday morning of the flight, was accom- plished in a driving rain. This is believed to have been the first time that a plane, in mid-air, has ever been refueled in a rain- storm. N INNOVATION in refueling was intro- duced by Robbins. The pipe into which the re- fueling hose was to fit was connected at the side of the Fort Worth instead of sen ms wee A REALS ETE ~~ we se elle Oe CC lS Ss & wet owe ot bed ee ee oe ee

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2 rome reranammagm Seal Avueust, 1929 being placed in the top, as was the case on the Question Mark. This was done to reduce the danger of fire or asphyxiation through spilling of gasoline over the ship. This is how the delicate and dangerous refueling maneuvers were executed: HE Midland, the refueling plane, also a Ryan brougham, piloted by K. K. Hoffman and carrying H. S. Jones as “contact man,” went up early each morn- ing and again twice in the evening to supply the Fort Worth’s needs. While the refueling ship hovered over the endurance plane, Jones dropped a thirty-seven-foot hose through a hole in the bottom of the Midland. Meanwhile, Robbins pulled his ship under the supply plane in such a way that the funnel, situated back of the right wing of the Fort Worth, would main- tain a position some twenty feet under the hole in the Midland. Kelly then caught the end of the hose and inserted it in.the funnel. While the gas was turned on from the upper ship, Robbins flew with one hand on the “‘stick” and the other on the throttle. When the tank was full, he pulled to the left and dropped away. Although a distance of twenty feet between the two planes was the rule, only ten feet of the hose was used on a few occasions! Six- teen of the seventeen contacts made during the flight were ac- complished without a hitch. Once, fifteen gallons of gasoline were spilled when Kelly forgot to re- move a rag used to keep dust from the funnel. The contacts, Which occurred at an altitude of from 2,500 to 4,000 feet, took eight minutes each. About 110 gallons of gasoline were transferred in the mornings and from 130 to 140 gallons more in the two re- fuelings at night. Twice daily, four and a half gallons of oil were taken on by the Fort Worth. D, sacks of mail, and news- papers also were low- ered to Robbins and Kelly at regular inter- vals. Thus, living for more than a week from half to two miles above civilization, they enjoyed the novel experience of reading descriptions of the progress of their feat in their home-town papers from day to day! Even a touch of family life was intro- duced into this picturesque adventure. On Wednesday when, with seventy-six hours of flying to their credit, the pilots had passed the minimum halfway mark, Mrs. Robbins and Mrs. Kelly celebrated the occasion by “visiting” their hus- bands! The airplane in which they went up played about the Fort Worth for about f an hour, while the two couples had & good “plane-to-plane” talk by means of signals. : Mrs. Robbins and Mrs. Kelly virtually lived on Meacham Field during the week POPULAR SCIENCE MONTHLY of the flight. Here they were kept in con- stant touch with the flyers through notes dropped by Robbins. The pilots went aloft without para- chutes, but after Kelly’s near-mishap they asked for them. They received them on the third day, when Robbins dropped a note which said: “I am afraid the end is near! Kelly has a ’chute now and is thinking of his wife. I can’t refuel alone! In another note, re- ferring to the «| cramped three-by- three-foot space in which they slept, he said: “We can under- Three record makers. stand how people who live in small houses get by.”’ That was on Friday. After that came the storm, and Robbins, though he kept his nerve, had other things to think about than the dropping of jocular mes- sages. ORE than likely, both he and Kelly were heartened for their fight with the elements by a great ovation they received on Friday evening, when they had exceeded the Question Mark’s record by the necessary hour. Thousands of their friends and well-wishers at the air- port staged a celebration in which the entire city joined. The Fort Worth swooped to within 100 feet of the crowd and the pilots waved their thanks to the Marvel Crosson, girl flyer of San Diego, Calif., who set an unofficial women’s altitude record of 24,000 feet. Top: Barney Zimmerly, who climbed 24,600 feet to break world’s alti- tude record for light planes. Left: Herbert J. Fahy, a test-pilot, who stayed up nearly thirty-seven hours for a new solo endurance mark. 19 throng who cheered and waved in reply. Similar scenes were again enacted on the Sunday afternoon of their descent. Then the flyers received, in addition to cheers, a fund, raised by the Fort Worth Association of Commerce, which had passed $12,000 by the time they landed. They received also nearly $2,200 from six air transport com- panies which jointly offered them $100 for each hour they would stay aloft after break- ing the Question Mark’s record. HEIR splendid achievement im- mediately seemed to serve as an incentive for a number of other fine aerial feats. Three days after the landing of the Fort Worth, Herbert J. Fahy, test-pilot for the Lockheed Air- craft Company, of Los Angeles, Calif., broke all records for solo endurance. flights, staying aloft thirty-six hours, fifty-six min- utes, and thirty-six seconds. Fahy not only shattered the official rec- ord of thirty-four hours and fifty- three minutes established by Royal Thomas, but also the un- official mark of thirty-five hours, thirty-three minutes, and twenty- one seconds hung up by Martin Jensen. The previous day, Barney Zim- merly, of Marshall, Mo., had established a new world’s altitude record for light airplanes by as- cending to a height of 24,600 feet above Park Airport, East St. Louis, Mo., in a 690-pound low- wing Barling NB-3 monoplane. LIMBING in a cabin mono- plane until the altimeter indi- cated a height of 24,000 feet, Miss Marvel Crosson, of San Diego, Calif., set an unofficial altitude record for women the same day. The previous mark, made by Mrs. Louis McPhetridge Thaden, of Oakland, Calif., was 20,270 feet. A day or two before the vic- tories of Zimmerly and Miss Cros- son, all existing speed records for military seaplanes were smashed by Lieut. W. G. Tomlinson, of the Navy, who covered the 100-mile course over the Potomac River at an average speed of 175.01 miles an hour in the tenth Curtiss Marine Trophy Race. In France, about the same time, Com- mandants Weiss and Girier, French army pilots, broke the world’s speed record for a distance of 5,000 kilometers (about 3,125 miles), flying their 600-horsepower army plane twenty-six hours at an aver- age speed of 180 kilometers (about 112 miles) an hour. Finally, at Dessau, Germany, Willy Neunhofer reached an altitude of 41,795 feet, nearly eight miles above the earth, exceeding the recently-set world’s record of Apollo Soucek, U. S. Navy pilot, by 2,655 feet.

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20 POPULAR SCIENCE MONTHLY Aucust, 1929 Now—Phone Home from a Train! Operation of the amazing new train telephone service is pictured here by our artist. In circle: W. D. Robb, a, vice president of Canadian National Railways, telephoning from train. At left: Exchange board of central relay station for phone service to and from a train moving fifty miles an _ hour. TERMINAL OR “CENTRAL” STATIONS, -~ F* AT INTERVALS OF ~~~ 15O MILES, RECEIVE MESSAGES FROM TELEGRAPH WIRE ANTENNA 20-WATT BROAD- FCASTING EQUIPMENT .s > BY LISTENING IN_ON.CALLS RECEIVING SET. BROAD- CAST PROGRAMS f ARE PICKED UP WHEN PHONE IS NOT IN USE TWO FOUR-WIRE SENDING AND RE- CEIVING ANTENNAE ON ROOF OF COACH 2 TRANSMIT AND RECEIVE CALLS W. G. Barber, general manager of Canadian National Telegraphs, talking from his Toron- to office to a train speeding a mile a minute and 150 miles away. CENTRAL STATION SENDS MESSAGE ~ ON OVER REGULAR LONG DISTANCE: > TELEPHONE LINES & LONG-DISTANCE telephone conversation, the first of -its kind in North America, was car- ried on, the other day, between a passenger on an express train speeding fifty miles an hour toward Allandale, Canada, and a friend in an office at Toronto, 150 miles away. Officials of the Canadian National Rail- ways immediately announced that two of their crack limited trains will be fitted with the telephone service. Passengers then may call anyone living in North America who owns a telephone! How the feat is accomplished is pic- tured on this page. When a train pas- senger talks into the telephone, the mes- sage is carried to a radio transmitter in the coach, and sent out from an antenna on the roof. The radio waves are used only to bridge the gap between the racing train and telegraph wires beside the track. The wires act as a receiving antenna, carrying the message to a “central,”’ with receiving equipment, located in a railway station. Such “central” stations are to be established 150 miles apart. From them, the message is transmitted over regular telephone wires to the party called. When a message is sent to some- one on the train, its progress follows a reverse sequence. The combination of radio and telephone is being applied also to ocean liners and_air- planes. One trans-At- lantic vessel has installed an experimental instru- ment and regular ship- to-ship and _ ship-to- shore telephone services are promised soon. Two- way radiophones have proved so successful in aircraft that, as reported in PopuLar ScIENCE MonrTu ty, they were in- stalled recently as a reg- ular service on planes of a western air line. _— eee: on oo ae a a a ee ae s+ 2 Soe er _

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POPULAR SCIENCE MONTHLY Warming up the Diesel motor of the oil-burning ‘‘mys- tery plane’’ for its first public demonstration at Langley Field, Va. 650 Miles by Plane for $4.68! Startling New Facts About the Oil-Burning Diesel Motor That Promises Sweeping Changes in Aviation WO men recently slid down from the sky and landed their plane on Langley Field, Virginia. They had come to attend the Fourth Annual Engineering Research Conference held under the auspices of the National Advisory Committee for Aero- nautics. No one noticed them particu- larly—the arrival or departure of an air- plane at an aviation field is a common- place occurrence. But as soon as the plane was safely on the ground, things began to happen. Huge special tarpaulins were swished out of the fuselage and the motor was wrapped up like a mummy. Then heavy chains were drawn around the tarpaulins and secured by padlocks. The men were Capt. L. M. Woolson, of the engineering staff of the Packard Mo- tor Company, and his assistant, Walter Lees. They had just completed an epoch- making flight in a plane powered by a secretly-designed new motor that may revolutionize aviation. ae Captain Woolson still is un- communicative about the details of the “mystery motor,” which he designed, he disclosed one important fact: The air- - plane had traveled from Detroit to Lang- ley Field, a distance of 650 miles against adverse weather conditions, without halt or trouble of any kind, and at a fuel cost of only $4.68. A similar airplane, powered by the ordinary gasoline aviation motor, would have used more than twenty- seven dollars worth of fuel on such a trip! Captain Woolson at last was persuaded to stage a demonstration. Experts were not permitted to make a detailed exami- nation of the motor, which in outward appearance so closely resembles the standard gasoline airplane motor that the average man could not tell the differ- ence. However, the fact that the motor By ROBERT E. MARTIN Capt. L. M. Woolson, Packard motor engineer, designer of the new Diesel type airplane engine. burns fuel oil instead of gasoline, coupled with such details as could be seen, makes it possible to give a general description of the motor and to some extent forecast its possibilities. The new motor is of the Diesel type. Its use of fuel oil instead of gasoline elimi- nates one of the most serious hazards of airplane eperation—the ever-present pos- sibility of fire. It has nine cylinders set like the spokes of a wheel. The familiar spark plugs and carburetor which form an indispensable part of the ordinary gas- oline aviation engine are absent. There is only one valve in each cylinder head. The engine is of the four-stroke type and operates at from 1,700 to 2,000 revolu- tions per minute, about the speed of ordi- nary gasoline aviation motors. It is said to weigh about three pounds for each horsepower developed, as compared with an average two-pound weight for each horsepower of the gasoline type motor—a disadvantage which is more than offset by reduction in weight of fuel, as will be shown later. HE forerunner of Captain Woolson’s creation is the heavy, lumbering Diesel engine built only in large sizes for industrial plants and motor ships. Curi- ously enough, mystery surrounds Dr. Rudolf Diesel, the German engineer physicist who invented the engine which bears his name. He disappeared from a cross-channel steamer while on his way to England just before the outbreak of the World War. The operation of the Diesel-type engine is simple in principle. In the four-stroke gasoline motor used for airplanes, metor boats, automobiles, and so on, the piston on its down stroke draws a charge of gaso- line mixed with air in through the car- buretor. On the next up stroke the charge is compressed, and at the top of the stroke an electric spark ignites the mixture and the piston is driven down for the power stroke. On the next up stroke the exhaust gases are expelled through the exhaust valve and the cycle is repeated. The four-stroke Diesel motor operates in much the same way except that when

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22 POPULAR SCIENCE MONTHLY Aucust, 1929 the piston goes down, instead of drawing in a charge of gasoline and air, it draws in a charge of plain air. When it comes up again it compresses the air to a pressure of about 500 pounds per square inch, compared with the ninety pounds of compression in the average gasoline motor. At the top of the stroke a small quantity of liquid fuel oil is squirted di- rectly into the highly compressed charge of air and, since compress- ing air to 500 pounds produces a temperature of about 1,000 de- grees F., the fuel immediately ignites and drives down the pis- ton. The following up stroke, of course, drives out the exhaust gases through the exhaust, valve. has two valves, one to let in the charge of gasoline and air, the other to let out the exhaust gases. The Diesel marine engine also has two valves for each cylinder. Captain Woolson’s motor, on the | other hand, has but one valve for | | HE common gasoline motor | | COOLING FINS fe & & ‘ \, AIR INTAKES NINECYLINDERS \ \ (AIR COOLED) \ \ Our artist’s impression of the new mo- tor. In general appearance it resembles the ordinary gasoline airplane motor. NOSE OF AIRPLANE OIL INJECTOR \ MECHANISM affect the operation of the other cylinders. Ignition, of course, cannot fail. So long as the pis- tons compress the charge of air to 500 pounds the temperature of the compressed charge will in- evitably rise to 1,000 degrees F., and this temperature is consider- ably hotter than what we ordi- narily term “red-hot.” Will Captain Woolson’s engine have any effect on the develop- ment of the automobile? Fore- casting future developments is a rather uncertain business, but it must be apparent that the new en- gine ought to find its place in buses and trucks if not in ordi- nary autos. AS AVIATION engine is op- erated at or near full power practically all of the time, and the Diesel type engine is inherently suited to such operation. Unless, though, Captain Woolson’s motor has features that do not appear on the surface, it would not be ideally | adapted to the operation of an | ordinary automobile, the speed of each cylinder. Consequently, this valve performs both the functions of letting in the charge of air and letting out the exhaust gases. The valve opens at the bottom of the stroke in the usual manner and remains open practically for a complete [revolution of the flywheel while the piston is coming up to drive out the exhaust gases and going down again to draw in the fresh charge of air. This construction is possible in the Diesel type airplane motor because of the short exhaust pipe and the absence of a muffler. The one-valve arrangement would be impossible in a marine type motor because of its long exhaust pipe and rauffler. The common method of starting the smaller sizes of Diesel marine engines is by compressed air, which is fed to the proper cylinder by means of a rotary valve. Captain Woolson starts his motor by the pressure of a button on the control panel in the cabin, and as several of the witnesses of the demonstration noticed a smell like gunpowder as the motor was started, it is quite possible that he uses the ordinary compressed air system in starting, rearranged to operate by the ex- plosions of charges of gunpowder. The possibilities of the new Die- sel aviation engine are tremen- dous. The record shows that Cap- tain Woolson used but fifty-four gallons of fuel oil traveling from Detroit to Langley Field. A similar gasoline-powered plane would have used ninety-one gallons of gasoline. While fuel oil weighs slightly more per gallon than gasoline, there is a notable saving in the weight of fuel required to drive the plane for a given distance. This means that a Diesel-powered airplane, in addi- tion to costing far less per mile for fuel, should be able to carry enough of it to go many more miles than a gasoline-powered plane. It is not too much to expect that new nonstop distance flights will be recorded and records may even be set that may never be equaled by gasoline-driven planes. Reliability is quite obviously the first and most important feature of an avia- tion motor, and in this respect the new Diesel aircraft motor, is in a class by it- self. There being no electrical ignition system, the usual troubles with short- circuited spark plugs, burned-out magne- tos, burned timer contacts, and so on, are eliminated. In addition, the absence of electrical apparatus on the motor greatly simplifies the use of radio transmitting and receiving apparatus in the airplane. F COURSE, the Diesel aircraft mo- tor can be disabled by a failure in the oil supply, and in this respect it is no im- provement over the usual type of gaso- line-driven motor. Valve trouble should be cut in two on the Diesel aircraft motor because it uses just half the number of valves employed on a gasoline motor. Carburetor troubles, too, are eliminated, because there is no carburetor. The flow of fuel oil into each cylinder is controlled by a separate pump- ing arrangement so that the failure of the fuel supply on any one cylinder would not COMPRESSES AIR TO 500 LB PER SQUARE IN N UP STROKE AT TOP OF STROKE LIQUID FUEL IS SQUIRTED IN The four strokes of the Diesel motor. Its compression is more than five times that of the gasoline airplane engine. which must constantly be changed to meet traffic and other conditions. In buses and trucks of the electric drive type, however, the motor is connected di- rectly to an electric generator so that con- stant speed can be maintained. The Diesel engine already has won its spurs in the higher horsepower units adapted to marine and stationary use and consequently Captain Woolson’s develop- ment of the Diesel aviation engine will have little effect in this direction. One other point must be considered. The production of any large number of airplane engines designed to use fuel oil in place of gasoline undoubtedly would re- sult in an increase in the price of fuel oil and perhaps a decrease in the price of gasoline, so that the advantage of low cost of operation for the Diesel motor would tend to disappear as larger and larger numbers of them went into use. But even if the price of fuel oil should be boosted, the Diesel airplane engine still would have a great advantage over its gasoline-operated competitor. Leaking pipes or even the worst crash landing can- not result in a fire, for fuel oil cannot be ignited by a spark as can gasoline. It will ignite only under the ex- treme temperature in the cylinder at the top of compression stroke. T MAY truthfully be said that the introduction of the Diesel engine eliminates fire risk in air- plane operation. A dirigible filled with helium gas and operated by Diesel motors likewise would be immune to fire. As this is written, reports from Germany state that Prof. Hugo Junkers, famous aero- nautical engineer, is now experi- menting with a Diesel engine pow- ered plane. His experiments also are veiled in secrecy. It is appar- ent, therefore, that there is going to be competition in the development of the Diesel aircraft motor. It is a rich prize for which the engineers are competing—but America seems to be in the lead so far! Pet RE RE oF ST ERNE 8 ERATED

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Pee Sh Omen ae ey eee TC Harvey Wiley Corbett (left) inspecting pneumatic mail carrier in N. Y. Post Office. Aueust, 1929 POPULAR SCIENCE MONTHLY 23 ubes to Link City and Airport POSTAL CLERK SORTS LETTERS IN THE AIR ry : / PASSENGERS ARRIVING AT Baas AIRPORT tA DaTH OF TUBES / AND TUNNELS ‘4 vy i UNDER CITY UTURE high- anal passenger EUMATIC TUBES SHOOT MAIL CONTAINERS 1O AIRPORT POS ¥ OFFICE .~ Vi 4 UNNEL FOR AND TUBey4 oe if bes 7 and mail connections between if ‘ congested cities and their sub- / ‘ urban airports, as recently iia predicted by Harvey Wiley Corbett, SUBWAY CAR GRINGS ti edie oi SUBWAY CAR noted American architect, are pic- PASSENGERS FROM AMRPOR ——— “ tured. here by our artist. Air mail, : Al PORT, packed in bulletlike containers, he “9 .says, will be shot by compressed air 3 through underground tubes running na between the airport and a centrally “% AR same size AS located city terminal. Incoming and or phew! CABIN SO ACH LOAD FiLiSA outgoing air line passengers will be MACHINE ATTHE whisked through a superspeed sub- way in streamlined cars. The air terminal in the city will Le much like that of a railway in its accom- modations. Here passengers will consult a Our artist’s conception of future high-speed subway and pneumatic tube sys- tems for rushing passen- gers and mail between city terminal and airport, as predicted by Mr. Corbett. HARDENED STEEL POST OFFICE “SL? moitrs on ices ©information clerks, buy tickets, and de- \-. eral —- ., stax scend to waiting subway cars, each of which will hold the same number of people as the cabin of an air liner. Arriving at the airport, they will step out and enter . the waiting plane, already tuned up on its concrete embarking platform. In the post office section’ of the ter- minal, and also at the airport, air com- _pressors will supply mighty blasts to drive the letter containers to and from : the air field. Incoming mail already will enim” have been sorted into the containers in . AND CONCOURSE the air by a clerk aboard the plane. A successful experiment in handling mail by “‘ underground air guns” has been made in New York City. There twenty- five stations are connected by speedy Drawn Especially for | pneumatic tubes said to transport letters POPULAR SCIENCE a distance equal to five and a half times MonrTHLY by B. G. Seielstad around the earth every day. SORTING MAIL TO BE PLACED IN DIFFERENT eg SONTAINERS AIRWAY TIME-TABLES NETTER 4 Ba PNEUMATIC MAIL 4 - > CHUTE MECHANISM FOR KONTAINERS ] DIRECT HIGH SPEED DELIVERY TO AIRPORT

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“There we were, on the wind swept shore, jawing at each other for all we were worth.”’

(Crushed in the Jaws of Arctic Ice Famous Old Sea Dog Who Won Glory with Peary Spins a Brisk Yarn of Adventure By CAPT. ROBERT A. BARTLETT As Told to FITZHUGH GREEN FEW years ago I braced myself abaft the wheel against a howl- ing northeast gale, with black darkness of midnight around me, and watched my poor ship. the steam sealer Leopard, fight a losing battle for her life. There was little we could do to save her. High seas were sweeping us toward the wild chaos of trash ice that lines the outer Newfoundland coast in early spring. Bitter cold numbed our hands. Our hull had sprung a dozen leaks. Our engine was sobbing its heart out over the impossible task of holding the ship against the tempest. “Maybe we could get a fore staysail on her!” the mate yelled into my ear. “Try it!’ I yelled back. They hadn’t a ghost of a show. But it would keep their minds off death. For an hour the men struggled waist deep in foaming seas. Frozen canvas tore the skin from their knuckles. One man’s arm was nearly torn from its socket. Twice the sail started up and was snatched away by the wind. Finally it was torn to ribbons, flapping into the night like the shredded garments of a scarecrow. The ship suddenly began to vibrate. It was as if a giant were underneath, pounding her hull with a huge mallet. Roar of the Captain Bartlett lashing empty drums under his schooner, the Morrissey, when she ran on a reef in north Greenland in 1926. She came off three days later. wind and sea was too great for us to hear anything. But we could feel it: thump— ker-plunk! Quiver—crash! It was the ice; great jagged floes raftered by the wind and tossed about by the sea. First we would lift and slam down on one; then another would lift and slam down on us. The chief engineer came crawling to me over the wet deck. “She’s taking more water!” he sang out. “‘More than we can handle!” I told him to give his blamed pumps more steam. He got mad and left. But there was nothing we could do. The ice

Aucust, 1929 would have us in kindling in another thirty minutes. The sea would drown us in five more; even in life preservers swimming men cannot live long in zero weather. , Most of the men came aft. They knew our boats wouldn’t last a minute in the ice even if we could get them launched. As Newfoundlanders, they knew many a ship had gone out and never come back, leaving no trace. It looked as if we'd soon be another such mystery. CARED? Not exactly. I guess we felt more angry than scared; sore at getting such a tough break and not hav- ing a chance to do anything about it. Then all of a sudden the Leopard seemed to get more on an even keel. At first I thought I must be growing a little weak-minded. But the wash had stopped. And I could begin to hear the ice, instead of just feel it. I held a lantern over the side. Instead of black water I saw a rough white surface. Providence had been good to us. We had been blown in among the heavy ice jammed against Wreck Point about a hundred miles north of Brigus, where my home is. But the floes were grinding and the bumps we had been getting changed to ugly pressure. Streaks of dawn were just showing‘in the east when the chief and his dirty gang came out of the engine room. “We quit,” he said. “‘She’s stove in all along the port bilge.” I ran to the rail and saw that the floes had cut into her lower timbers like a knife into cheese. We ripped spars and timbers out of her until we could lay a sort of walkway over the trash ice alongside. While we worked, the foremost shrouds popped like rifle shots and the whole shebang went over the forecastle with a noise like a warehouse collapsing. CARCELY had we got onto the slush ice than the Leopard went down. She didn’t splash or corkscrew; she just seemed to melt into the ice. It was a hard sight for us who had called her our ship. Slipping and falling, we somehow made our way across the floes to the rocky beach. We were done in by the time we touched dry land. Only it wasn’t dry, on account of the snow flurries that still blew in off the sea. There was a bit of wreckage there, the bow of the old Delmar, which had foundered here some years before. We crawled in, wet and shivering, and waited for daybreak. Some “As I plunged in, the shock of the cold water on my bare skin was just like getting a thousand volts of electricity.” Ft . at - pt Pn, _ - * Kote . —— “§ < yoann — PA _ a

a eer ape

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wT wa a ee \e@ Avueust, 1929 fishermen found us later and our lives. saved * * * Captain Bartlett shook his head as he ended his recital, which was taking place in the tiny after cabin of his schooner Effie M. Morrissey. Before him on the one deal table lay a chart outspread. “FP\HERE’S the spot,” he said reverently, marking with a thick thumb the un- marked grave of his last sealing ship. In the brief silence I studied this famous mariner, trying to see what it was in him that kept him perpetually at his hard calling. Weighing over two hundred pounds, all solid brawn, with a ruddy weather- beaten face, voice hoarsened by forty years at sea, he made a fine picture of a seaman. “Not many real sailors left.” I spoke my thought aloud. Captain Bartlett sprang to his feet, nearly knocking a fine sextant on the deck. “Real sailors!” he snorted. “There ain’t one man out of fifty that goes to sea today who knows what sailoring is! Monkey-wrench sailors is what we’ve got! Good to grease a bearing and tighten a bolt. But when it comes to passing an earring on the main yard—!” Loudly the captain blew through his nose and glared at me until I felt as if it were somehow my fault. I quickly changed the subject. “‘ You’ve seen mutiny?” I asked. “Mutiny.” He rolled the word on his tongue, lifting a corner of his upper lip as if it were distasteful. “Yes, friend, I saw it on the Solent. I'd rather not give her real name, as her owners are still in business. In the late fall we shipped a cargo of Newfoundland seal oil and hides for a European port. It came on to blow; not a full gale, but a smart breeze that kicked up a nasty sea. “ ABOUT a week out of port we ran into really dirty weather with over- cast sky, patches of raw fog, and the wind still holding. As luck would have it our rudder gear jammed. On account of the heavy sea running we couldn't get it fixed. “For the better part of another week we drifted until we were clear of the trade Captain Bartlett sighting through his sextant—a fine picture of a sea- man, all solid brawn, with ruddy, weather-beaten face, voice hoars- ened by forty years of life at sea. POPULAR SCIENCE MONTHLY routes. Then the ship’s company began to fall ill. First, we thought it was a case of food poisoning. But the symptoms told us it was something worse. “ AS YOU know, the old ships carried no doctor. Medical equipment was all put in a small chest which the captain kept. In the top of this chest was a book of instructions. If a man had a pain in his side, fever, vomiting, and a rash, the captain simply wrote those things down in a list and looked up the disease in the book that corresponded. Then he’d get the proper medication out of his chest and administer it. “You can imagine our feelings when we learned from the cook, who had it from the mate, who had it direct from the captain, that there wasn’t anything in the book that fitted the symptoms our sick men were having! “One man died. Another lay dying. A dozen were stricken. There began to be mutterings. At night in the forecastle the deck hands gathered and discussed the terrible situation. There we were, a drifting derelict, miles from the routes ships traveled, and a mysterious malady sweeping down upon us like a curse. “*Tt’s all right now, lads,’ the mate told us one morning, a day or two later. The Viking, Newfoundland sealer, in which Captain Bartlett’s father went seal hunting for many years. It was in this same Viking that the explorer Nansen, as a lad, first went into the Arctic. “We ripped spars and timbers out of her until we could lay a sort of walkway over the ice.’’ “We’ve got the rudder fixed and we're 999 going on. “On that same day a big sailor we had aboard, a man who had once been in com- mand of his own vessel, but had been reduced for drinking, declared that if any of us were going to get home alive the ship ought to be taken west to the nearest port instead of east to Europe. He figured we could reach medical help in a few days if we turned about. “By night he had won the crew over to his way of thinking. A committee went to the captain and told him they thought he ought to put back west to save us all from dying of the disease aboard. “TTXHE captain nearly had apoplexy, He was a heavy-set man; domineer- ing and very strict. ‘Mutiny!’ he shouted right off. ‘Ill mutiny you—you loafers!’ With that he grabbed a belaying pin off the starboard after rail and rushed for the spokesman, who nearly fell down a hatch trying to keep from having his skull fractured. “That night the crew tried to capture the ship. I couldn’t join either side be- cause I was flat on my back with pains and fever. But the captain, mate, cook, and two loyal sailors were ready for the trouble makers. The captain didn’t pay much attention to any but the leader. He grabbed him and threw him over his shoulder like a professional wrestler. Then he had the mate bind him and lock him in a lazarette under the cabin. “At seeing their leader captured the mutineers lost heart that night and decid- ed to wait until daylight. In the morning the captain made some of them come up and talk to him. In his hand he had a big revolver, the only firearm on the ship. ““*We’ve got the topsails on her,’ he told them. ‘The mate and the cook and I will steer. If you don’t want to set any more canvas it'll take us maybe two months to reach port. If you want to make sail we can make it in three weeks with some luck. Take your choice. But meanwhile don’t (Continued on page 139)

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POPULAR SCIENCE MONTHLY AucGust, 1929 Keeping Pace with Aviation Poy +. sant Mo YS ‘ as O ae 2» Nad . UN; > STATED t. * — We ~ x é ‘ ‘ ad E .va3 4, . + 5 STETTIN paca Gfcuina i & aus Sis er SOLSK AFRICA Route of proposed nonstop flights around the world. Circles along the course indicate points of contact with refueling planes. Three Plan to Girdle World—Nonstop! HREE nonstop flights around the world are in prospect. Each of three intrepid air adventurers has his mind set on being the first flyer to circle the globe by airplane without setting wheels on the ground. The three are Art Goebel, Dole flight winner across the Pacific; Parker Cramer, co-pilot on the ill-fated Greater Rockford flight, and Albert D. Hulse, U. S. Army Reserve, former air mail flyer on the New Orleans-to-Pilottown route. All three are assembling equipment, plotting routes, and locating refueling stations. Aeronautical experts regard the under- taking as the greatest aerial venture ever planned. The route to be followed will cover approximately 13,500 miles, and from five to five and a half days will be required to complete it. The amazing refueling endurance flights of the Fort Worth and of the Army plane Question Mark, described in an article on page 17 of this issue, gave ample demonstration that a nonstop around-. the-world flight is possible with the proper equipment. In fact, these flights inspired Goebel, Cramer, and Hulse to plan the attempt. ULSE has announced that his plane will be equipped with five 420-horse- power motors, capable of a maximum speed of 120 miles an hour and a cruising speed of 110 miles an hour. Only three motors will be used in flight. The other two will be kept for emergency.. The plane, he said, will be of metal and linen fabric con- struction, built to accommo- date a crew of six with a compact galley and sleeping quarters. Its gasoline tanks will have a capacity of 1,900 gallons, sufficient for the long, overwater hop from Nova Scotia to Scotland. Hulse proposes to start from Roosevelt Field, New First Rocket Plane. hopes to fly by the same means. York, the early part of October. His route will carry him up the New England coast to Boston, to Nova Scotia, across the Atlantic ocean to Scotland, over Germany and Poland, across Moscow, over northern Siberia to Nome, Alaska, down the Pacific coast to Seattle, Wash., and then across the northern part of the United States to New York. Twenty-two refueling stations are to be established. Ten of these stations are to be used only in emergency. The re- fueling planes will be similar to those used to keep the Question Mark in the air for 150 hours. ULSE’S plane will start from New York with its gasoline tanks only half filled. When over Boston, it will be met by the first of the refueling ships and the tanks filled. This is because the dan- ger of fueling while in flight is much less than that of attempting to take a heavily loaded plane off the ground. Trying to take off with too heavy a load caused the failure of many attempted trans-Atlantic flights. Motors which would be severely taxed to lift a heavy fuel load from a ~ a> hold the rockets, whose recoils are counted on to propel the plane. Metal compartments at the rear will dead start are capable of lifting twice the load while in flight. A second refueling plane will meet the around-the-world ship over Nova Scotia and the tanks will be filled to capacity for the long water hop. The first of the re- fueling planes in Europe will meet Hulse’s ship off of Glasgow, Scotland. Other re- fueling contacts will be made over north- ern Germany—Stettin; Moscow, Siberia, Nome and Juneau, Alaska; and at Seattle, Wash. Emergency refueling stations will be located across the United States, but they are not expected to be needed. The flight across the Atlantic and over the waste lands of Siberia will be made at an altitude of from 14,500 to 20,000 feet to benefit by the strong westerly winds which prevail at these heights during the early fall. Huge Flying Boats for Great Lakes Service IANT air boats, each holding as many people as a standard sleeping car, are to link Cleveland, Detroit, and Buffalo in a new Great Lakes air line. The metal hulls for the first two of the boats are reported under con- struction at Lake Constance, Germany, by the Dornier- Wahl Company. When com- pleted, they will be shipped to this country and fitted with American motors and furnishings. Each plane is to have four 500-horsepower motors, an innovation which Col. Charles A. Lindbergh recently prophesied would be the next step in increasing safety of air passenger travel. The plan is for the winged boats to fly at an average height of about 200 feet during the speedy trips which are expected to save almost an hour between Cleveland and Detroit. Constant radio communication will be main- tained with the shore. Lunches will be served in the air. The designer of the hulls, . Dornier, is said to be completing, in Germany, @ Pre Fritz von Opel, the German sportsman who helped develop the spectacular rocket automobile, is seen at the right working on a bullet-shaped monoplane—a winged skyrocket which he Dr

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Auoust, 1929 Learning to Navigate U. S. Army pilots are being taught the technique of navigation at a special school recently opened at Wright Fieid, Dayton, O. Experts give in- struction in astronomical methods, dead reckon- ing, and radio direction finding. Here a group of students are shown learning to use sextants. gigantic, twelve-motored air-and-water boat. It will have a total of 6,000 horsepower, equivalent in output to five hundred motors like the one that drove the original Wright biplane in 1903! Other sky monsters are projected for air travel in Europe. An all-metal, fifty- five-passenger Handley Page biplane is under construction for the Imperial Air- . ways in England. Besides a main cabin for forty passengers, it will have a number of “private staterooms” holding one or two people. The big air liners will be used -on the London-Paris airway. The largest land plane in the world, a hundred-passenger Junkers, is reported being built in Germany. It is designed to fly at high altitudes, its equipment including superchargers for the motors and oxygen outfits for passenger cabins. Air Mail Saves a Day WHOLE business day is clipped from the coast-to-coast journey of air mail by a new flying schedule recently in- augurated. Two nights and a day, in- stead of two days and a night, make up the flying time of the planes, which cover two thirds of their trip in darkness. Thus, letters posted in New York at six o'clock in the evening are scheduled to reach San Francisco before the opening of business on the second day following. The installation, by the U. S. Depart- ment of Commerce, of beacons at ten-mile intervals over the western end of the route, has made night flying com- paratively safe all along the | airway. The old _ service, leaving i in the morning and arriving the second evening following, will be continued. Thus two transcontinental air mails each day will be provided. Exactly seventy years ago the first stagecoach line to California began carrying mails from St. Louis. It enabled a letter to go from coast to coast in the sur- prisingly speedy time, for that period, of twenty-four days. When pony express POPULAR SCIENCE MONTHLY Operating radio instruments of the practice plane—one of the essentials of the course. riders, a few years later, began racing across the plains in relays, they cut the time to twelve and a half days. The fast- est mail trains of the railroads still require almost eighty-three hours for the journey that the latest air mail service has reduced to thirty-two. New 500-Mile Beacon WHEEL of light, a thousand miles in diameter, will have its hub at Chicago when the colossal 2,000,000,000- candlepower searchlight, recently offered the city by Elmer A. Sperry, New York inventor, is installed. The $100,000 aerial beacon is to be named “ Lindbergh Light,” in honor of Col. Charles A. Lindbergh. It will revolve at the top of a 125-foot tower on the roof of a lake-front skyscraper. On clear nights, its beam, reaching 500 miles, is expected to sweep in a circle that An Airplane “*Plow Siieo. As part of the ceremony of breaking ground recently for a new airplane factory at Fairfax Field, Kansas City, Kas., a big biplane was hitched like a horse to a farm plow which it dragged down the field. This photo shows the mayors of Kansas City, Kas., and Kansas City, Mo., doing their best to guide the outfit. An idea any farmer might try. A student taking a sight from forward cockpit of a monoplane used as a flying classroom. will touch twelve states—one fourth of all those in the Union! It will be visible to night flyers from Buffalo, N. Y., on the east, to Omaha, Neb., on the west and from the Canadian border above the Great Lakes, on the north, to Memphis, Tennessee, on the south! The light, it is said, will actually be more dazzling than that of the midday sun! At Chicago, on the hottest days, it is com- puted that the sunlight’s intensity does not exceed 900 candlepower for each square millimeter, while at the lamp, the illumination sent forth surpasses this intensity by almost 100 candlepower. Aerial Photos by Night N AMAZING “cat’s-eye camera,” which takes aerial photographs at night unseen, was demonstrated recently during the war games in Ohio, in which almost 200 fighting craft of the sky took part. The instrument, the secrets of which are closely guarded by the U. S. Army, is designed to enable observation planes to photograph enemy troop movements or the activity around military centers under cover of darkness. The camera is described as being synchronized with a flashlight apparatus whose illumination is so instantaneous that it does not register on the human eye. Exposures made during these quicker- than-the-eye flashes may be developed while the plane races back to its own lines and can be dropped at headquarters by parachutes, placing them in the hands of Army officers within ten or fifteen minutes after they have been taken. Because the flash is invisible to human eyes, it is said, the camera will enable silent planes to circle over the enemy in the dark, taking photos — their presence being known. A Box of Fog J, filled with fog is part of the equipment being used by the Massa- chusetts Institute of Tech- nology, Cambridge, to learn more about this enemy of air- men. The long wooden box, tightly sealed, is filled with vapor from a boiler and a beam of light is shot through the artificial fog bank. A (Continued on page 29)

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A Perilous Perch. This sky photo pictures a thrilling moment in the recent un- successful attempt of Martin Jensen and two comrades to break the world’s refueling endurance record in monoplane Three Musketeers above Roosevelt Field, N. Y. It shows Jensen on the catwalk, in full blast of the propeller’s backwash, repairing a gas leak, New Valveless Motor A remarkable new type airplane motor, featuring sixteen air-cooled cylinders without valves, is shown at the right with its inventor, G. E. Franklin, president of the Franklin Aeronautical Corpora- tion, during a recent demonstra- tion at Kansas City, Mo. He predicts that it will bring radical changes in the design of both air- craft and automobile power plants. Weighing 359 pounds, the new engine is said to develop 400 horsepower, or better than one horsepower per pound. Franklin began work on the invention soon after the close of the war. Un- usual parts of the motor, including substitute for crank shaft, are shown in circle below, center. Maps Alaska from the Air A ribbon of photographic film longer than a city block feeds into this newest auto- matic aerial camera, used by the Govern- ment expedition, led by Lieut. Com. A. W. Radford, above, which is mapping 10,000 miles of uncharted Alaskan territory. . The instrument makes four exposures simu)taneously : one downward, one ahead, and two at the sides of the line of flight. POPULAR SCIENCE MONTHLY Parts of new motor. EW airplanes, airports, airways—they’re com- ing so fast that it’s a lively task to keep informed of them all. Pictures and brief articles on these pages give you a clear and fas- cinating view of the impor- tant advances in aviation. Aucust, 1929 Shot from a Warship Recent maneuvers and battle practice of Uncle Sam’s Pacific Fleet off southern California demonstrated the vital part scouting and observation planes will play in future naval engage- ments. This photo was snapped just as a big Navy observation seaplane was catapulted from the deck of the U. S. S, Tennessee. Cam that replaces crank shaft (center); double-ended piston (right); connecting rod. “Lindy”? Oils the Family ‘‘Car’’ Before—and after—Col. Lindbergh’s re- cent marriage to Anne Morrow, daughter of the American ambassador to Mexico, he led reporters a merry chase by his frequent and unheralded flights. Here he is standing in the rain at Portland, Me., greasing motor of plane he flew from Maine to New York with his bride-to-be and members of her family shortly before the wedding. Aen en a a ae RA Bl TA stereo , ME ee ae | fr; Oo & peZ &

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A earn A REBAR Pt m8 © AE Ser 6% te SAAT ti ete sonia Ralaaniatiu tt Aueust, 1929 photo-electric cell permits recording of the amount of light that penetrates the vapor. Various kinds and colors of light are being tried. Real fog banks, coming in from the sea, are also studied with special instruments sent aloft on captive balloons and kites. The experimenters hope to develop a means of classifying fog, and measuring accurately the visibility on different days, thus giving more exact information to cross-country flyers. Checking the Air Records O TO the Bureau of Standards, Wash- ington, D. C., some day after you have read in your newspaper of an American aviation record being broken, and you will find a studious young man working with strange looking instruments, retracing the flight and determining to a mathematical precision just how much the new record exceeds the old one. This man, who has the final say on whether a new mark has been set, is H. B. Henrickson, assistant physicist in the Aeronautical Instruments section. Whenever a flyer tries for a record, the barograph, or recording instrument car- ried on his airplane, is forwarded to Henrickson for computation. He removes the smoked-chart cylinder, on which atmospheric pressure has left its tale- telling trace by means of a stylus, and places it in a “fixing”’ solution to preserve a more or less permanent record of the flight. The entire barograph, with the excep- tion of the outside cover, is placed under a spe- cially prepared bell-jar. There, with the clock- work mechanism of the instrument ticking away and a stylus following the waving, scratched line left by the flight, Henrickson is able to follow every movement of the airplane on its record-breaking attempt. This process is called the “flight history test,” in which temperature and pressure and rate of change during the flight are duplicated. In an altitude flight, for example, Henrickson will start the stylus of the pen arm on the ground pressure | line of the barograph chart. The air is exhausted at a rate approximately the same as that shown by the trace until the lowest, or “ceiling” pressure of the flight is reached. A pressure reading is taken on a standard mer- curial barometer connected to the bell-jar. This pressure is then con- verted into feet altitude. Reproduction of temperature changes are necessary to accurate reading of the chart. Henrickson has invented a simple airplane thermometer, which is attached on wing struts, to give an accurate record of temperature changes. Student Pilots EARLY fifteen thousand Amer- | can young people are experi- encing the thrills of learning to fly which Larry Brent has been recount- POPULAR SCIENCE MONTHLY ing in PopuLar ScreNcE Montuiy. The Department of Commerce reports 14,082 student pilots licensed at present—a number that could man all of the war planes flying on both sides of the trenches at the end of the World War. A year ago there were only 2,235 licenses of all classes, from students to the highest rank of transport Ms Cures Engine Cough Commander Karl Smith, U. S. Navy, with device he has invented to clean air entering carburetor of a seaplane engine, thus preventing spray water from stalling the engine, Airplane thermometer that was devised by Henrickson to record temperature changes. Aviation’s Referee H. B. Henrickson, assistant physicist in the Aeronautical In- struments Section of the Bureau of Standards, checking barograph N used by Lieut. Soucek in altitude X flight of 39,140 feet. Right: , Temperature recorder on strut. om Nw => od - The new air cleaner installed on seaplane. In- rushing air, whirled by vanes, is freed of water. pilots, registered in the United States. Because commercial air transport com- panies eagerly seek pilots with Army flying experience, a special ruling was recently made to attract flyers to fill the depleted ranks of the Army Air Corps. Civilian pilots will be accepted for one year’s serv- ice and given the rank of second lieutenant, Major General James E. Fechet, Chief of the Air Corps, announced recently. Plane Dispatchers Now T ONE end of the long runway at Roosevelt Field, New York, a man in white overalls waved a red and a green starters’ flag the other day, inaugurating a new safety feature at the famous American airport. As airplane dispatcher, he signaled the machines when to start and kept the field clear of taxiing planes when pilots were preparing to land. Starters with their flags have been a familiar sight at flying meets, but few air- ports in this country have used them. Now that the planes at large air fields are as numerous on ordinary days as they used to be at aviation meets, control of the traffic is needed. A Monoplane-Biplane . A MONOPLANE in the morning; a biplane in the afternoon! You can take your choice of which kind of craft you will have, if you own a Belgian machine recently demon- strated in this country. Interchange- able wings allow it to be converted quickly from one type of machine to the other.’ King Albert of Belgium, who is a skilled aviator, flies one of the convertible machines. Safety Overalls ° ABORATORY _ experi- LU menters found, some # years ago, that orange- ~~ colored objects are most easily seen from a distance. Now an air field at Kansas City, Mo., announces that its attendants will wear orange overalls, so that pilots preparing to land can see them readily.

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HE Franklin Institute f Philadelphia t he other day presented the Edward Longstreth Medal for meritorious work in science to John F. Peters, consulting engineer of the Westinghouse Electric and Manufacturing Company, at Pittsburgh, for his invention of the “klydonograph,” the only simple device in existence for “fingerprinting” the most elu- sive and deadly enemy of elec- tric power transmission—light- ning. When lightning flashes from lowering clouds and strikes a modern transmission line, it cripples the power circuit and vanishes again, all in a few millionths of a second. Yet, in that incredibly brief space of time, the klydonograph takes a rogues’ gallery picture of the marauder and its Bertillon measurements. In fact, the de- vice, in laboratory tests, has recorded artificial surges lasting less than ten billionths of a second! Until Peters perfected his amazing little apparatus, there was no way of gathering the evidence lightning leaves after striking power lines. To protect them from this menace, scientists must know the enemy’s characteristics. How powerful is it? How fast does it strike? How long does it stay? Which way does it go? The klydono- graph answers these questions. It is a sensitive eight-day camera, which now stands guard aoe over many Lt. A. J. Williams, American known as “Amer- transmission ica’s fastest fiyer.”’ lines. It takes care of itself except for a weekly change of photo- graphic film. Clockwork in the device tells the time of the lightning shock and turns the film spool. The size, intensity, and arrangement of the delicate lines in the developed klydonograph picture tell sci- entists all the peculiarities of the “finger- printed” lightning bolt. The man who invented this instru- ment never had the advantages of mod- ern technical training. Born and raised on a farm near Chambersburg, Pa., he had to do his share of the chores and so rarely attended the one-room country school more than five months in a year. The result was that he remained in its POPULAR SCIENCE MONTHLY John F. Peters, Westinghouse consulting engineer, with the klydonograph he invented to take “‘fingerprints’’ of lightning. People in the Public Kye classes until he was eighteen years old! Peters’ parents had decided to make a carpenter out of him, and he followed that trade for a time, but he had made up his mind to become an electrical en- gineer and so he studied electricity and mechanical drawing in the evenings after work. When he was twenty, the Westing- house Electric Company refused him admittance to its two-year electrical course because of lack of technical train- ing. Young Peters took a job as an elec- trician with the Pittsburgh Steel Com- pany at Monessen, Pa., and doggedly continued his studies. A year later, he again applied at the Henrietta H. Swope, of the Harvard Observa- tory staff, who discovered 400 new variable stars. Aucust, 1929 Westinghouse works and de- clared himself willing to do any kind of work. He was given a job in one of the shops and after three months was made assis- tant foreman of the section making D. C. motors. But Peters was not: satisfied. Sacri- ficing a considerable portion of his foreman’s pay, he secured a position in the Transformer En- gineering Department. Mean- while, for twelve years, he dili- gently pursued his’ evening studies of engineering, mathe- matics, and other subjects. In 1918, Peters was made a free lance in the Transformer Engineering Department, devot- ing his time to consulting work and special problems. High- voltage transmission, continuity of power service, and abnormal voltage and current investiga- tions kept him busy during the next few years. The klydono- graph is one of several develop- ments of this period. In 1925, Peters was appointed consulting engineer for the entire West- inghouse organization. A little over forty years old, the man who, twenty years ago, lacked sufficient technical training, today has more than thirty patented inventions! Genius of Bridges HE U. §&. War De- partment re- cently had un- der considera- tion a plan, submitted by the North River Bridge Company, of New York City, to build a rail- way and high- way suspension bridge _across the Hudson River from Fifty-seventh street in Man- hattan to the New Jersey shore. It called for a double-deck structure with a single span of 3,240 feet, to be connected on the New York side with a great union pas- senger station. The new bridge would accommodate at least 40,000,000 vehicles, 400,000,000 passengers, and 25,000,000 tons of freight per year. Its cost is es- timated at about $200,000,000. The designer of this gigantic project, who originated it some thirty-five years, ago and has been working for its realiza- tion ever since, started his career in this country as a stone mason in the grounds of the Phila- (Continued on page 135) Gustav ‘Lindenthal, designer of famous bridges and tunnels. — ote ete elle SO oe oe ~~ fe hCUMDlUet — —_— TT = = =

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Aucust, 1929 POPULAR SCIENCE MONTHLY 31 Has Our Earth a Glass. Heart? MOUNTAINS WERE FORMED BYE THE FOLDING OF THE CRU By AS THE EARTH COOLED AND SHRANK —. JOHN E. LODGE F YOU could put the earth under a super X-ray machine and look clear through its vitals—what would you see? You would be startled to find that the “‘heart”’ of our planet is an immense sea of liquid glass, taking up about half of its 7,900-mile diameter! Surrounding this great molten-glass core, you would observe a layer of metal, probably 1,000 miles thick—the distance from New York to Chicago!— and resembling the iron found in meteorites. Above that, you would come upon a stratum, again about 1,000 miles in depth, con- sisting of dark-colored fire- formed basalt rock. And finally, you would notice that the outer “shell ”’—the earth’s crust on which we live—is a comparatively thin skin composed of gran- ite reaching to a depth of only some thirty miles. DEEP HAT, at least, was the imaginary “‘X-ray pho- tograph” of the earth’s interior projected a few weeks ago by Dr. Reginald A. Daly, professor of geol- ogy in Harvard University. His theory of the liquid glass core enveloped by successive layers of iron, basalt, and granite is at com- plete variance with that of a number of other scientists, who still assume that the earth is “‘a molten ball of fiery ma- terial with only a very thin crust between man and realistic hell-fire.” The planet’s “glass heart,”’ according to Dr. Daly, is subject to the incon- ceivable pressure of 50,000,000 pounds on each square inch, and to the intense heat of 50,000 degrees centigrade! The continents and oceans on which we live, the Harvard geologist said, are in constant process-of sliding and floating on the great glass sea that occupies the earth’s center. This motion, causing landslides of enormous blocks of the planet’s surface, is responsible for earth- quakes, volcanoes, and the formation of mountains. What probably happened, according to Dr. Daly, was this: The earth developed from gases pulled away from the sun. Millions of years ago, while these gases were being transformed into liquids and semisolids, the planet met with a gigantic catastrophe, in the course of which a huge chunk of it, which later became the moon, was hurled into space. How the earth’s interior might appear if we could put it under a giant X-ray machine—a drawing based on the remarkable new theory advanced by Dr. R. A. Daly, noted Harvard geologist. ‘\ OUTER SHELL Sac OR CRUST OF Mose GRANITE,ABOUT lige 30 MILES y \ EARTHQUAKES AND VOLCANOES ARE CAUSED BY LANDSLIDES OF HUGE BLOCKS OF THE FART CRUST RIDING ON GREA GLASS CORE This early disaster may have been caused by tre- mendous tidal waves rolling over the earth or by the fact that it was pear-shaped and lopsided at the time. At any rate, the planet has never quite recovered from that cosmic accident and ever since then has shown a tendency to correct its dis- torted, unfinished shape and perfect its symmetry. The “landslides” of the earth’s outer crust and the crumplings on the downside of these slides, which cause mountain ranges to rise and great masses of lava to spout to the surface, are probably the re- sults of the unceasing tendency of gravity to overcome the planet’s original distorted condition. In other words, whenever an earthquake occurs or a volcano erupts, the earth is putting forth another effort to make itself into a smooth, round globe. Challenging the theory that the earth’s heart is molten, Dr. R. R. Cummings, head of the Indiana University Depart- ment of Geology, recently declared that our globe is solid to the core and has re- Y + STIMATED AT EIC -HES. THIS 1S JSE OF MINOR SHOCKS AROUND a Drawnespecially for POPULAR SCIENCE MONTHLY by B. G. Seielstad . sistance to change of form as great as if made of finest steel. “The fact that the earth continues to rotate,” he said, “is evidence of rigid- ity. Raw eggs will not spin about their long axes, due to internal friction of the liquid contents; hard-boiled eggs will.” He also cited the fact that great earth- quakes shake the entire earth. And he contended that the center of the earth is a core of nickel-iron, with a radius of about 2,100 miles, immediately surround- ed by a shell of magnesium and iron silicate about 440 miles thick.

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32 POPULAR SCIENCE MONTHLY Aucust, 1929 Reese —A Man Who Always Does the Impossible By FRANK PARKER STOCKBRIDGE F ALL America’s in- dustrial and _ eco- nomic changes in these amazing ten years since the war, the most colorful, and in many ways the most important, is what may be termed the “chemical revolution.” Out of the laboratories have poured scientific discoveries which have transformed our world. Where we were drab, we are now brilliant with color. Where we dressed in cotton, we now wear rayon. Where we were dependent upon foreign sources for such essentials as fixed nitrogen for fertilizers and explosives, we now take our own nitrogen from our own air. And we do all of these things more cheaply and in larger ERE is the story of a man who has started a revolution, the end of which nobody can foresee—a chemical revolution. It is the story of an extraordinary man who helped win the war, and who has given us the opportunity to live better and more cheaply than ever before. It is an intensely human article, depicting one of the marvels of our day.—The Editor. cellulose powders for our own Government and others, as well as for industrial and sporting purposes, buying our supply of diphenylamine from Germany. “Then Germany began the war and the world’s supply of the essential stabilizer for smokeless powder was cut off. “We had to find out how to make it. And we had to learn quickly.” T WAS a problem compli- cated enough. America had no aniline dye industry—that was a German monopoly, America had almost no com- mercial supply of the coal-tar intermediates from which ani- line is made, hence, no supply of the basic products from which diphenylamine was volume than anyone dreamed possible, ten years ago. Where ,we had fewer chemists working in industry than any other civilized nation before the war, we now have more trained chemical brains than there are in all of the rest of the world put together! Behind every revolution there is a mind. Thousands of minds coéperated to bring the chemical revolution to fulfill- ment, but somebody started it. Who? I asked chemists, industrialists, any- body who might know, to name the man who started the chemical revolution, who put chemistry into American industry. Some said this man and some said that, but most of them said “ Reese.” OI went to Wilmington, Delaware, to see Dr. Charles Lee Reese, founder of the great Du Pont chemical laboratories, for many years the company’s chemical director, today a director of the corpora- tion and its consultant on all technical matters. ““Is it true,” I asked him, “that you won the war by discovering the chemical secrets of the Germans?” That was one of the things that had been told me about Dr. Reese. The dignified, courteous gentleman to whom I put the question smiled depre- catingly. “Don’t attribute too much to me,” he said. “It is true, however, that we did succeed in surprising the German govern- ment and the German scientists at the very beginning of the war.” They had thought, the Germans, that they alone held the secret of smokeless powder. The essential ingredient, di- phenylamine, the stabilizing element with- out which nitrocellulose powders cannot be made, came only from German laboratories. Even the great Du Pont company imported its supply of this chemical, a by-product of the great German aniline dye industry. Nobody else could make it, the Germans thought. Derived from coal tar and the manufac- ture of gas and coke, it was one of those carefully camouflaged chemical secrets for which the German chemical industry was famous. But the Germans apparently had greatly underestimated Dr. Reese. “The British had to have smokeless powder, instantly, in huge quantities,” Dr. Reese told me. “‘They were caught unprepared for the war, and there was no place except the United States to which they could turn for ammunition. “The British government offered us a huge contract for powder, with time limits so close that at the best our facil- ities would be severely taxed. We ac- cepted the contract, although we did not know where we were going to get the diphenylamine essential for use as a stabilizer. “My work since 1902 had been chiefly in the development of nitrocellulose powder for the United States Army and Navy. While in Germany, in 1908, I learned that German chemists, by the use of diphenylamine, had solved the problem of stabilizing nitrocellulose, to insure against premature or spontaneous explosion. “T could not obtain the secret formula for its manufacture but I did arrange for asupply and we began making nitro- made in Germany. But Dr. Reese is not only a great chemist but a great organizer. He called his staff heads together. “There are two ways that I think of by which diphenylamine can be produced,” he told them. ‘“We’ll turn over one laboratory to one line of research, another entire laboratory to the other.” And to the heads of these two groups he said: “Hire all the additional chemists you need, requisition whatever supplies and apparatus you require. Go toit, both of you. Never mind,the expense. Go to it—and get it!” The laboratories went to it. * E TOOK the British contract and started production of smokeless powder at once,” Dr. Reese told me. “I know that the Germans laughed at our confidence—they told me so, some of them, after the war was over. We could go only so far; then our supply of the stabilizer would be exhausted and we could make no more powder for Eng- land.” : Day and night the laboratories oper- ated, scientists worked in twelve-hour shifts, trying this reaction, testing that result. Meantime, so confident was Dr. Reese that they would succeed, that he did not wait until the answer had been found before arranging for supplies of the coal-tar products from which aniline is made. Then one morning, Dr. Reese found the head of one of the two laboratories waiting at the door when he reached his office. ““We’ve found it, chief!’ he exclaimed. “Here’s a sample. (Continued on page 130) = So a =| pot

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Avaust, 1929 4 Cer eee a A BRIG ars - —- Z 7 POPULAR SCIENCE MONTHLY Drawn Especially for Porputar Sctznce Montaty by B. J. Rosenmeyer Dr. Cuartes Lee Reese, Father of Industrial Research IGNIFIED schoolmaster, he taught industry how to draw fabulous wealth from research in pure science. From his work as founder and director of the great Du Pont chemical laboratories at Wilmington, Del., have come the beautiful, weather-defying finish of your car, artificial silks for your wife’s stockings, dyes to make your world gay with colors, and many other wonderful products in everyday use. Today, at the age of sixty-seven, he still devotes his scholarly mind to the service of utilizing the discoveries of science for the benefit of us all.

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34 POPULAR SCIENCE MONTHLY Avausr, 1999 first motoriess In this birdlike glider Lilienthal made his spectacular flights by in 1891. He was killed leaping from the top of a hill near the Baltic Sea in northeastern in glider crash in 1896. Germany. His daring feats led to the invention of the airplane. The first military airplane—the Wright brothers’ biplane successfully passing U. 8. Government tests at Fort Myer, Va., July 30, 1909. Nearly six years earlier, December 17, 1903, the fitst : successful powered plane, built by the Wrights, A pioneer machine that almost flew—Dr. 8. P. Langley’s ‘‘aerodrome”’ made its historic flight at Kitty Hawk, N. C. on a houseboat from which it was launched above the Potomac River, October 7, 1903. It crashed into the river, as it did in a second test. Famous Flights—A Vivid Story of Aviation in Pictures A pioneer in cross-country flying. Gienn H. Curtiss in his biplane at start of the historic Albany-New York flight, May 29, 1910. He won New York World prize of $10,000. Monoplane in which Louis Bleriot, French airman, first flew across English Channel, July 25, 1909. Right: Alberto Santos-Dument, who made first airplane flight in Europe, September 13, 1906—600 feet. The first flight from the deck of a battie- ship—Eugene Ely, in an early Curtiss " biplane, hopping from the VU. 8. 8. * Pennsylvania in 1911. A great event Adolphe Pegoud, firet flyer to loop-the- in the advance of naval aviation, and Glenn H. Curtiss, inventor of the hydroaeroplane and flying loop, in the monoplane he used for one which forecast airplane carriers. boat, giving first public demonstration of a plane equip- the stunt near Paris in September, 1913. ped with pontoons, at San Diego, Calif., January 26, 1911. Pie LE ea LO A eee

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sees Avaust, 1929 POPULAR Mail arriving in Washington, D. C., from New York, after a flight establishing world’s first regular air mail service, May 15, 1918. The crew of the NC-4, first aviators to tridge the Atlantic. Lieut. mander A. C, Read, commander of flight, is at extreme left. Sister the NC-I and NC-3, also made the attempt, but were forced down at sea. after falling in mid-ocean. — ~~. ey a, aitiag n 29 eh nS be ae Se SCIENCE MONTHLY 35 First to fly the Atlantic. The U. 8. Navy’s flying boat NC-4 in the Azores on the way from Newfoundland to England via Portugal. The flight be- gan May 16, 1919; the plane arrived at Plymouth, England, on May 31. Harry Hawker, British pilot who, with Commander Grieve, at- tempted a nonstop flight from Com- Newfoundland to Ireland, May 18, - ships, 1919. They were picked up ~ Their crews were rescued, Patrol boats were stationed along the way, VERY step in the advance of flying has been a romance of reckless daring and high adventure. How many of these past heroes and their thrilling feats do you recall? To them aviation largely owes its present status as a thriving industry. First nonstop flight across the Atlantic. Capt. John Alcock (right) and Lieut. A. W. Brown, of the British air service, crossed from St. Johns, Newfoundland, to Clifden, Ireland, June 14, 1919, flying 1,960 miles in sixteen hours, twelve minutes, and winning London Daily Mail prize of $50,000. Upper photo shows their plane after the flight. British dirigible R-34, first lighter-than-air craft to cross the Atlantic, landing at Roosevelt Field, N. Y., after 3,120-mile flight from East Fortune, Scotland, Start- ing July 2, 1919, the trip took 108 hours. The return voyage to Pulham, England, was without mishap, Major S. H. Scott, commander of the airship, stands at center in upper photo. At the extreme left is Lieut. Commander American observer on the flight, who was killed later in the Shenandoah disaster.

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36 POPULAR SCIENCE MONTHLY ' Aucust, 1929

: First nonstop transcontinental flight, . — . Lieut. Oakley G. Kelly (center) and U. 8S. Army flyers, led -by Capt. St. Clair Streett (third Lieut. James A. Macready (left), who from left), who beat all records in a 3,575-mile flight flew from Mitchel Field, N. ¥.. to from New York to Alaska, July 15-August 24, 1920. San Diego, Calif., May 2 and 3, 1923,

Three of the four Army round-the- world planes arriving over Long Island, N. Y., near the end of their 27,553-mile trip, in 1924, Leaving Seattle, Wash., April 6, they flew via Alaska, Japan, India, Persia, Tur- key, Austria, England, Greenland, and Newfoundland. Two completed the flight safely on September 28, Lieut, Russell L. Maughan (right) standing beside the Army pursuit plane in which he made the first dawn-to-dusk flight across the continent, June 23, 1924. flyers in England. Left to right: Lieut. Leigh

Lieut. Lowell Smith, and Lieut. J. Harding.

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Flying boat ia which the Spanish airmen, Comman- der Ramon Franco ard Capt. Ruiz de Aida, blazed a 6,230-mile trail from Spain to Buenos Aires, Argentina, by way of Canary and Cape Verde Islands, in 1926. Completing first round-trip Eng- land-Australia flight—Alan Cob- ham landing on the Thames River, October 1, 1926, Delivered across the ocean—Uncle Sam’s dirigible Los Angeles, formerly the ZR-3, landing at Lake- hurst, N. J., after a flight of 5,066 miles from the Zeppelin works at Friedrichshafen, Germany, October 12-15, 1924. It carried 32 passengers on its nonstop flight of 81 hours and 17 minutes. Across the U. s. in see Hop—The Army Flight around the World—England to Australia, and Spain to Buenos Aires

oa oe” a es a Se st __ ———— Ose tae nee oO

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soar Aveust, 1929 POPULAR SCIENCE MONTHLY 37 Who can forget that first daring airplane flight over the North Pole? Right: Monoplane Josephine Ford, piloted by Commander Richard B. Byrd and the late Floyd Bennett, leaving Spitsbergen for fifteen-hour hop to the Pole and return, May 9, 1926. Below: Roald Amundsen, famous Viking explorer, congratulating Byrd, And how the world was thrilled by the history-making flight of the dirigible Norge, carrying the Amundsen-Elisworth-Nobile ex- pedition, from Kings Bay, Spits- bergen, over the Pole to Teller, Alaska, May 11-14, 1926. Above: The Norge starting the 2,700-mile voyage. Right: The late Roald Amundsen, commander of ship. Army amphibian planes over tropical waters on U. S. Good Will tour through Latin America. Five planes, led by Maj. Herbert A. Dargue, left San Antonio, Tex., December 21, 1926. One crashed. Four flew 20,470 miles, arriving at Washington, D. C., May 2, 1927. Right: President Coolidge welcoming the flyers at Bolling Field. ‘ f ‘ eed Wr Overshadowed but by no means eclipsed by Lindbergh’s great hop to Paris was the record nonstop flight of Clarence D, Chamberlin from New York to Eisleben, Germany, in the monoplane Columbia. With Charles A. Levine as passenger, he started from Roosevelt Field, N. Y., June 4, 1927, and flew 3,911 miles in 424 hours, Above: The Columbia nose down in a German swamp. At right: Chamberlin (left) and Levine before the start at Roosevelt Field, Air Pioneers Who Blazed the Long Trails—Lindbergh, Byrd, Chamberlin, Amundsen, and the U. S. Army Good Will Flyers The great story of Colonel Lindbergh and the first New York-Paris flight, May 20- 21, 1927, was retold in pictures in last month’s issue. Here ie the Spirit of St. Louis flying from Belgium-to England.

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Trans-Atilantic passenger travel by airship reslly began with the great flight of the Ger- man dirigible Graf Zeppelin from Fried- richshafen, Germany, to Lakehurst, N. J., October 11-15, 1928, With a crew of forty, twenty passengers, and freight, she traveled 6,630 miles in 111 hours 46 minutes, though buffeted and damaged by storm. The photo shows the Zeppelin passing over New York, Westward across the Atlantic in an open cockpit biplane. The start of the 4,200-mile flight of Capt, Francisco Jimenez and Capt, Ignacio Iglesias, Spanish airmen, from Seville, Spain, to Bahia, Brazil, March, . 1929,

Jirnenez and Iglesias, standing beside their plane at Seville before the start of the flight to Brazil. Loaded, the machine weighed 10,000 pounds. It was equipped with a 500-horsepower motor. > Yale. = POPULAR SCIENCE MONTHLY “Breguet biplane in which they made 35,000-mile

Aucusr, 1929

First to fly the Atlantic westward in a single hop—from Africa to Brazil, Capt, Dieudonne Costes (left) and Joseph Lebrix, French aces, in

Lady Mary Bailey, British aviatrix, with daughters at Croydon airport, England, after a round-trip solo flight to Cape Town, Africa, starting March 9, 19928, flight around the world in 338 flying hours, start- ing and ending at Paris, October, 1927-April, 1928, pmiaimialy

American air heroes who, up to the summer of 1927, had distinguished themselves in ocean flights, photographed after a reception by President Coolidge. They include Lindbergh, Cham. berlin, Byrd, Balchen, Brock, Schlee, Ruth Elder, Haldeman, Levine, Maitland, and Hegenberger. U. S. Army plane Question Mark refuel- ing from ‘‘nurse ship’’ during record duration flight of 150 hours in California last January.

The Lockheed mono- plane in which Capt. Frank M. Hawks set a cross-continent speed record of 18 hours, 21 minutes, 59 seconds, February 4-5, 1929. The plane flew about 2,700 miles at an } _ ~, fee average speed of 150 ~ wo aoe * , miles an hour. A sie a5 ~ special cowling around Tecan i the Wright motor re- - eee a ae - te SE AE seas agg

duced air resistance and increased speed. Graf Zeppelin’s Voyage to America—First Westward Atlantic Crossing by Airplane—Great Distance and Duration Flights

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9 Avaeust, 1929 POPULAR SCIENCE MONTHLY 39 Commander Francesco de Pinedo, Italian Royal Air Force, who flew 30,000 miles over four continents, February 13-June 16, 1927. His course: Rome-Africa-South Am- erica-United States-Newfoundland-Rome. First to make a nonstop flight over the Pacific to Hawaii— Lieut. Albert F. Hegenberger (left) and hwy Lester J. Maitland, U. 8. Army Air Corps. In ‘the tri-motored monoplane The Bird of Para- dise, they completed the 2,407-mile hop from Oakland, Calif., to Honolulu in twenty- six hours, June 28-29, 1927. Art Goebel, winner of the Dole race from Oakland, Calif., to Honolulu, Hawaii, August 16-17, 1927, and $25,000 prize. Time: 26 hours, 17% minutes. Martin Jensen was the only other flyer to teach the goal. Of eight Wor } \ Ry) The race cost ten lives. Monoplane Woolaroc in which Goebel won Dole race with Lt, William Davis, Jr., as navigator. William 8. Brock (left) and Edward F. Schlee, who flew 12,300 miles, Newfoundland to Japan, in an attempted round- the-world flight, August 27-September 14, 1927, 2, Commander Richard E. Byrd and monoplane America after forced at Ver-Sur-Mer, France, in record senger ocean flight from Roosevelt Fi ¥., June 28-29, 1927. Left to right: N Byrd, Acosta, Balchen, Above: Wreck of the America after.fiyers had missed Paris in fog. eg H & z il The Bird of Paradise, Army transport plane, coming down to the landing field at Honolulu, Hawaii, after its nonstop flight over the ocean from California. It was the longest overwater flight at- tempted up to that time, and a triumph of skillful navigation. When the plane took off from Oakland, the load carried was 13,500 pounds—more than 6% tons—of which 6,240 pounds was gasoline, Colonel Lindbergh in Spirit of St. Louis arriving over Havana, Cuba, in his Good Will Tour of Central and South America, Between December 18, 1927, and Febru- ary 13, 1928, he flew 9,060 miles over strange country. The America’s Thrilling Atlantic Flight — Over the Pacific to Hawaii — Pinedo’s Amazing Feat — Lindbergh’s Good Will Tour

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40 POPULAR SCIENCE MONTHLY Fitst westward passage of North Atlantic by airplane. The German monoplane Bremen on Greenly Island, off Labrador, after 2,125- mile hop from Ireland, April 13, 1928. Right: Southern Cross fiyers. Left to right: Lieut. Com. Lyon, navigator; Capt. Kingsford- Smith; Capt. Ulm, co-pilot; James Warner, radio man. —— © ~ =; -. Gt ee Fe —-=- * FS a 6 i= . ————— ll - - ae 2 = a m aI ts a ~~ Earhart, first woman to cross the Atlantic by air- in the monoplane Friendship, after landing in from Newfoundland, June 17-18, 1928. She flew with Wilmer Stults, pilot, and Louis Gordon, i An attempted westward trans-Atlantic flight that failed. The flying boat of Capt. Frank G. Courtney and three companions in mid-ocean after being forced down, August 2, 1928. All were rescued by steamer responding to 8.0.8. Aucust, 1929 In this ski-equipped monoplane Capt, George H. Wilkins and Lieut. Carl B, Eielson made the first airplane flight across the Arctic Ocean, April 15-16, 1928. From Point Barrow, Alaska, they flew 2,200 miles to Spitsbergen in twenty hours and twenty minutes, In one of the greatest of all flights, Capt. Charles E. Kingsford-Smith and three companions, in the tri-motored monoplane Southern Cross, spanned the Pacific for the first time, May 31- June 9, 1928. From Oakland, Calif., they flew 7,400 miles to Brisbane, Australia, in 83 hours, stopping at Honolulu and Fiji Islands en route. Maj. Arturo Ferrarin (left) and Maj. Carlo del Prete (right), Italian pilots, made a record noristop flight of 4,466 miles from Rome to Rouros, Brazil, in $1 hours, 59 minutes, July 3-5, 1928, Below: Theit powerful monoplane. First Westward Atlantic Crossing — Wilkins’ Great Hop Over the Arctic — Pacific Ocean Spanned by the Southern Cross ween a? iT: ee SUSE 00

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le el ol a _ oes ? =. = eo ae Avueust, 1929 POPULAR SCIENCE MONTHLY Are You Interested in hovieatiill O YOU think POPULAR SCIENCE MONTHLY should run more aviation news, or less? The magazine is edited for its readers, and we have believed that a widespread general interest in aviation has justified the space we have given the subject. And yet here is a letter from a reader of long standing that surprised us: “ AM one of your old readers—in two senses of the word. I have been read- ing PorutarR Scr—eENcE MontTuiy for a dozen years, and a month ago I passed my sixtieth milestone. Perhaps you will consider me a bit old- fashioned. Perhaps I am, for that matter, although I am still active in my profes- sion, civil engineering, and last year was granted two patents in the automotive field, in which I have long been interested as a sort of avocation. “TI am prefacing this communication with these few statements so that you will not consider me hopelessly behind the times when I ask you whether you do not believe you are devoting entirely too much space to aviation. “Most of your covers for the last year or so have pictured aviation subjects, and it has seemed to me that I could not the gentleman, still we believe that his letter raises so many interesting points that it should be submitted to our readers to the end that we get a frank ex- pression of opinion from them. Are you interested in aviation? Have you flown, or would you like to fly? Do you own or are you planning to buy an airplane? Would you like to take a course in piloting as Larry Brent did? Would you use an airplane instead of a railroad train for a transcontinental journey? Would you like to see more or fewer arti- c'es in the magazine about the oppor- tunities in aviation? Are you interested in the new types of planes developed from time to time and in the new engineering features of these planes? These are just a few topics that our correspondent’s letter suggests. Un- doubtedly you have other ideas about aviation. Won't you write us a letter and express fully and frankly your views on the subject? Such letters are the editor’s best guide in producing the type of maga- zine best suited to your needs. If you are too busy to write a letter, you will help us by filling out the accom- panying coupon and mailing it to The Editor, Porputar Scrence Mownruty, 250 Fourth Avenue, New York City. Nine gentle we do not agree with turn two pages of any issue without en- countering an aviation article of some kind. You have had air mail, air trans- portation routes, airports, the ‘Fathers of Flight,’ ‘How I Learned to Fly,’ and whatnot. Most of it is interesting reading, I will admit, but, don’t you think, empha- sized all out of proportion to the impor- tance of the subject? “Aviation today has scant relation, in my opinion, to science or utility. The air mail is uncertain, transportation by airplane, despite claims of promoters, virtually negligible; private ownership of airplanes is a joke. A few people have airplanes merely to attract attention and show their neighbors that they can af- ford them. “I would not accept an airplane as a gift. I would not ride in one even if Lind- bergh was the pilot, and I am certain the _ Fill and Mail to the Editor vast majority of sensible persons feel the same way. Although I am, and have been for forty years, engaged in a profession that can be classified as scientific, I have no interest in the so-called science of aerodynamics, which does not move, has scarcely advanced since its princip!es were established by the Wright brothers. “You did print an article—by a British war pilot if I recall correctly—some time ago which considered these points. I applauded this at the time, for I believed at last you were on the right track, but in the very next issue you regained your membership in the aviation claque, and you have r2mained there ever since. “I would not counsel you to banish aviation entirely from your magazine, but I would urge that you treat it in its proper relation to other things.”’—J. P. F., Chicago, IIl. Out This Coupon Underline, in each case, the word or words which convey your answer. Dear Editor: aviation news. less I own——do not own planning to buy I use do not use for pleasure. I believe Poputar ScreENcE Monta y should publish more—— I am interested particularly in: 1. New types of planes. 2. Learning to fly. 3. Getting into aviation (a) as pilot. (b) as aviation engineer. (c) as mechanic. (d) as a business. a plane. an airplane for business an airplane for business transportation—— cote CCHS HOS OREO HOCH HHE SS OOM SD etoeoeeen 2 6 0 6 © £16 0. 2isteis 04 oe RES Oe ee oo 6 660 £ O46 66 6.0% *.4 © 6 © * 6056 Oe ee Serer Occupation....... Note: The foregoing is for the information and ScrENcE MonTHLy and is given to them in confidence. Mail to The Editor, PopuLar Science Montacy, 250 Fourth Ave., New York City. I am planning to buy not pleasure. idance of the editors of PopuLAR

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42 Capt. William A. Jones, famous firearms expert, comparing the “fingerprints’’ on two bullets under a double microscope. LITTLE black bag, twenty-two inches - long and a foot high, and looking for all the world like the traveling case you take along on. week-end trips, was recently presented to each of the detectives at police headquarters in New York City. These bags, however, The were not designed to hold pajamas, toothbrushes, and combs. They are portable miniature laboratories for use in the scientific detection of crime; an outfit devised by modern criminology to defeat the cunning of the evildoer and track him down. There are a huge magnifying glass, a complete fingerprint set, including the vacuura gun for blowing powder, white or black, and the powders themselves; test tubes in which to preserve such tell- tale exhibits as hair or finger nails of vic- tim or murderer; a searchlight capable of burning seven hours, a pair of rubber gloves, a trouble-finder, which is a lan- weapon. yard bearing a flashlight; steel mirror, small saw, hammer, three chisels, pair of calipers, screw driver, pair of tweezers, tape measure, set of colored crayons, paper, twine, and stenographer’s note- k. ISTRIBUTION of the new tool kit marks the latest step in crime solu- tion along scientific lines. The old-time “deduction” method, which depended largely upon the ingenuity and reasoning powers of the individual detective, is virtually a thing of the past. It has been superseded almost entirely by exact science and specialized knowledge. One of the newest branches of scientific crime detection is “fingerprinting” bul- lets. As an example of the effective work done in this field, take a case solved re- cently in Maryland by Captain William A. Jones, famous New York firearms expert. A gun was left beside a murder victim to suggest suicide. Relatives sus- pected foul play and called in Captain Jones. When he examined the fatal lead Characteristic marks of fir- ing pin and breech block revealed that shells in top row were fired in a different gun from those at bottom. Identifying a From bullet B, fired from suspected gun, a narrow strip was superim- posed on murder bullet A. markings POPULAR SCIENCE MONTHLY Aucust, 1929 aittle Black Bag to Solve Crimes By H. C. DAVIS and the gun, he found that the firearm had four grooves in the rifling inside the barrel, while the death-bullet had been fired from a weapon with six! Experts in ballis- tics, as the scien- ‘tific study of fire- arms is called, have murderer’s matched, discovered that every bullet is marked by the gun that shoots it and that no two guns are alike in this respect. First of all, the rifling varies. These spiral grooves within the barrel, which spin the bullet to keep it from somersaulting in its flight, twist to the right in some makes, and to the left in others. The number of these grooves varies from four to seven, and in some weapons they make a greater number of turns in a given distance than in others. A glance at a bullet will tell an expert what sort of barrel it passed through, and so narrow down the search for the weapon used in a killing. When a firing pin strikes the primer of a cartridge, it leaves a craterlike indenta- tion. Frequently a peculi- arity of the pin offers the expert a clue. Such was the case not long ago when a man was found dead by the roadside near Herkimer, N. Y. Both barrels of a shotgun had been emptied into his body and the two empty shells lay beside him. When examined, one shell was seen to have been ex- ploded by an ordinary firing pin and the other by a tri- angular one! State police searched the neighborhood and brought in a gun in which one pin had been broken and replaced with a piece of metal that made a - triangular dent. The owner confessed to the shooting. Another noted arms expert, Major Calvin Goddard, some weeks ago sought to solve the St. Valentine’s Day gang killings in Chicago and traced the fatal bullets apparently to the guns of gang- sters already under arrest. So impressed were the Chicago police that four detec- tives were sent to New York for training in similar work. And the Chicago cor- oner, on the same occasion, declared: Bi prey and fingerprinting are now equally important in crime detection.” Speaking of fingerprints, the recording of the impressions of the thumbs of criminals as a means of identification was one of the earliest processes introduced to take the element of guessing out of crime detection. The fact that fingerprints never change during the life of the in- dividual was discovered by J. E. Purkinje, a German physiologist, in 1823, and it was he who was largely responsible for their present classification. ‘There are three principal types—loops, whorls, and arches. The fingers of about sixty per- cent of all people have markings of the loop variety, thirty-five percent have whorls, and five percent arches. The Paris police force was the first to adopt fingerprinting. This it did in Black kit bags recently issued to New York detectives. Each contains the scientific crime detection outfit spread on the table. Pa

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Avoust, 1929 POPULAR SCIENCE MONTHLY N HIS revelation of the appalling crime “harvest” in America, President Hoover pointed out that “more than 9,000 human beings are lawlessly killed in the United States each year,” and that “little more than half as many arrests follow.” This article tells of remarkable detective methods developed by science to meet what the President termed the “dominant issue before the country.”—The Editor. 1882 as part of the elaborate system of criminal identification invented by Al- phonse Bertillon which, virtually un- changed, is used by the police of most countries today. Aside from making finger impressions, it includes taking measurements of various parts of the ‘body and recording the color of the iris of the eye. Today files of the New York police department contain more than 500,000 fingerprints arranged so that a particular specimen may be found for purposes of comparison within five minutes! HE number of sciences enlisted in the war upon enemies of society continu- ally increases. Chemistry, microscopy, psychology, biology, and general medi- cine have figured conspicuously in fa- mous criminal cases. More recently, Roentgenology—the scientific applica- tion of X-rays—geology, mineralogy, astronomy, ethnology, zoology, ornithol- ogy, botany, and even entomology, have proved invaluable aids to the detective, as have also metallurgy and various branches of technology, including spe- cialized knowledge of ink, papers, cloths, hair, dyes, leather, foodstuffs, and other substances. How chemistry, microscopy, and Roentgenology are used in the detection of fraudulent imitations of masterpieces of Nine Police photos of Paul Diamond—“ the man of many faces.’’ His cleverness in disguising himself was defeated by fingerprints. ' feiters of prehistoric ex- painting was described in PopuLar ScieNcE Montuty for May. Likewise, a knowledge of paleontology and geology have been employed to expose counter- cavations. Not long ago, geology was instrumental in solving a New York mur- der mystery. The re- mains of a woman's body, weighted down with pieces of stone, was washed up on the New Jersey shore of the Hud- son River. Detectives at first assumed that the stones were pieces of the rocks found where the - body was discovered, and hence that the crime had been committed in that neighborhood. Geologists of Columbia University, how- ever, established that the stones were parts of the foliated sock on which por- tions of upper Manhattan are built. In this way the crime was traced to up- town New York, where the murderer had obtained the stones from a subway excavation. Capture and conviction of the criminal followed. Entomology, bacteriology, and pathol- ogy a few years ago led to the solution of one of the most baffling murder mysteries in _his- tory. An elderly married man was found dead in bed in his home at Cape Town, South Africa. No marks of violence were found on the body, nor could physicians discover a “natural” cause of death. INALLY, a specialist diagnosed it as nagana, or sleeping sickness. This only deepened the mystery, for the tsetse fly, the carrier of the fatal germs, is not native to Cape Town. Then a detective had an inspira- tion! A man who was a close friend of the young widow had recently re- turned from a trip to a region 700 miles distant. An entomologist was con- sulted, and he disclosed that the tsetse fly abounded in that particular part of the interior! Next, the movements of the friend were traced, and it was soon found that he had imported the deadly insects and in- eer ce we ae eee > rot’s collection. SS = oe A typical fingerprint in Fau- Prints are on record, yet no two have been found identical. 43 J. A. Faurot, former New York deputy police commissioner, who introduced Bertillon system of identification to America. troduced them under the mosquito netting of the old husband. In many homicide cases chemists, by analyzing the remains of poison in the stomachs of victims, and of blood, drug, and acid stains on clothes, beds, rugs, and automobiles, have given in- valuable aid in tracking down culprits. In cases of drowning, water from the lungs is examined for flora, fauna, and mud peculiar to certain regions. Millions of COUPLE of years ago, discovery by a chemist of partly digested sardines in what was left of the stomach of a rich California rancher who had been shot to death and then burned beyond recogni- tion led to the solution of a crime that had been planned with diabolical in- genuity, and to the capture of the mur- derer. The slayer had put his own clothes on the body of the victim before cre- mating it, then had disappeared to create an impression of suicide. But before the murder, the two men had eaten at a hotel and the innkeeper, at the inquest, after recognizing bits of charred clothing as belonging to the murderer, testified that the man had had lunch at his place in company with a prosperous ranch owner who had ordered sardines! Shortly afterward, similar methods aided in establishing the identity of a wife-murderer and causing his subsequent arrest. In a shallow grave dug hurriedly on the outskirts of New York City, the police found the body of a woman in such an advanced state of decomposition that recognition was impossible. The stomach was sent to a chemical laboratory and all that was found were a few grape seeds. Then the neighbor of a man in one of the suburbs, whose wife had dis- appeared mysteriously about a week pre- viously, remembered having had dinner with her the evening before her dis- appearance. And they had eaten grapes for dessert! This at once fixed the iden- tity of the dead woman, and it was but the work of a day or so to capture and grill the husband, who confessed.

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D. Warren Boyer HE “deadly tail spin,” if you will take my word for it, is every bit as terrifying, as sickening, as sensa- tional, as deadly, as it is advertised. I anked Enslow if he liked tail spins. He answered with one those vague looks. A foolish question. No flyer likes spins. POPULAR SCIENCE MONTHLY Whirling to Earth in a Sickening Tail Spin! It Feel? You'll Know When You Read This Great Story By LARRY BRENT I have been in three spins; two voluntary spins and one into which I plunged against my will—because my sense of balance did not function quickly enough to save me. These spins were part of my flying instruction. I asked for them. I wanted to learn how to pull a ship out of a tail spin. For years I had been reading newspaper accounts of flyers being killed. “His plane went into a tail spin, and he could not pull it out.” Or, “It is be- lieved that So-and-So went into a tail spin from which he could not ex- tricate himself.” From the moment I started learning to fly it was in the back of my mind that, fairly early in my course, I would have my instructor show me how to pull a ship out of a spin. I wanted that lesson behind me before I took my first solo flight. When- ever it came into my mind, I asked my in- structor when we would do some spins. I had had a little more than six hours of instruction when Randy Enslow, my in- structor, said: “47OUR air work has been improving. Your take-off is improv- ing, too. And your land- ings are fair—as fair as we can expect at this stage. I think the time has come to show you how to get out of a spin.” ie Aucust, 1929 ry Brent Our plane had duplicate controls, but we did not use the speaking tube. . When Enslow pointed upward it meant climb; downward meant glide. How Does We wore parachutes. Randy Enslow has twice had to make parachute jumps from planes to save his life. He mentioned these jumps one time when I asked him whether he thought it would be all right if I “bailed out” some morning just for the thrill of it. Enslow has a way of looking at people who ask him silly questions. It is a look that does not have to be elaborated with words. His eyes go dull. His mouth goes slack. It is as though he were watching the antics of animbecile. But this time he elaborated the look with fifteen words: “The only times I used a parachute I would have been killed if I hadn’t.”’ HAD heard about one of those jumps. A salesman-demonstrator from one of the parachute companies gave us a lecture one morning in ground school. He showed us, in the classroom, just what happens when the rip cord is pulled—how the parachute spills out of its pack, and how the neatly stowed cords unfold. Then he showed us how a parachute is repacked— a laborious, delicate job. After his lecture and demonstration were over, he said to the ring of students and pilots surround- ing him—there were at least thirty men in the crowd: **My plane is outside. If any of you boys would like to go up and make a jump, today would be a perfect day for it. No wind. The ground is dry. Who would like to go up with me and make a jump? I mean, of course, it will be free.” How many men, among them some dare-devils of the air, jumped at this chance? Not one! The circle of flyers and fledglings jeered and hooted. Jump out of a nice, safe plane? Not on your life! Said one flyer: ‘“‘When I see my wings breaking off and go floating by, then I'll jump.” Without a single exception, every flyer I have talked to has said the same thing. a weet eee ee ee el Se te ee, - tee ie eh i a) lao} & @ de a &, mo ert o

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Aveust, 1929 No parachute jumps for them unless it 1s abso- ly necessary. Gisin William—Bill —Purcell, who is in charge of the Curtiss Ground School, told us of oneof Randy Enslow’s parachute jumping ex- periences. Enslow has had more hair-raising experiences than any flyer I have met. On this occasion he was flying alone in a cabin plane. He happened to be wearing a parachute. An- other ship smashed into him and folded both wings back about the fuselage, there- by making Enslow a prisoner in a trap which was hurtling to earth. HAVE been in a plane when Enslow pulled it out of some tight corners, and I know how quickly he must have acted on that. occasion. He kicked a hole through the side of the cabin and squeezed out feet first. Then, somehow, his head became caught! He twisted, kicked, and wiggled, but could not free his head. In another few seconds, Randy certainly would have been a dead man. He reached down and pulled the parachute rip cord. The chute blossomed. Would it snap his head off—or pull him clear of the wreck- age?: It yanked his head out of the trap— and he floated to earth. Among the old war flyers there was a saying, “Don’t use up your luck.” It meant, don’t tempt fate by- flying too long, because sooner or later you'll crash. Randy Enslow has “‘used up” more of both kinds of luck than any man I ever knew. He has been in more perilous positions—and had more miraculous, whole-skinned escapes. Enslow and other veteran flyers insist that these escapes are seldom miraculous. They are the happy results of hundreds of hours of flying experience. The longer you fly, the safer you become, the readier is your brain to deal with split-second emergencies. Lieutenant Arthur Phillips, a well- known Army flyer who, for a time, was an instructor at Curtiss Field, reduced this rule to figures. I asked him one time how long it would take a flyer to learn every- thing about flying. He answered: “A man can be a good flyer and make a good living at flying without knowing everything. I recently made a survey among Army flyers, asking them how long it took a man to learn to fly perfectly. According to them, a flyer did not stop learning until he had flown about 1,200 hours. They agreed that, up tothe 1,200th hour, a flyer seldom makes a cross- country trip without learning something new.” THOUGHT that that estimate was too extreme until I made inquiries at the New York office of Pan American Air- ways. I wanted to know how much ex- perience a flyer must have to join their pilot staff. I was informed that senior pilots (each Pan American ship carries two pilots) must have flown at least 2,000 ours; that junior pilots must have flown 1,500 hours. Major Burtis Thomson, an Army flyer, put it this way to me: “You will get into tight squeezes at 1,000 hours that will scare you green— POPULAR SCIENCE MONTHLY because you won- der how you would have handled the same situation at your 200th or 500th hour.” Randy Enslow said: ““It depends on how and where you pile up your hourage. A man who has done barnstorming is better at his 500th hour than a flying field flyer with 2,000 hours.” Assen Jordanoff, who was my first instructor and who flew with the Germans during the war, disagreed, and asked Enslow to ex- plain himself. Enslow did. ‘*‘A barnstormer has to bring his ship down into places where a ship has never landed before—into \ fields in steep In and out of a tail spin. Tail is up, not down as popularly believed, and revolving madly. The nose is revolving, too. valleys sometimes, - and into fields no larger than back yards. Every inch of the way down is new territory. You don’t know what updrafts, downdrafts, or cross currents to expect. But you land your ship. And your next town will present an entirely different set of problems. A barnstormer flies his ship!” “And makes nothing but side-slip landings,” Jordanoff gibed. This may need explanation. Good pilots consider a straight glide a more workmanlike approach to a landing than a side-slip. Sometimes a side-slip landing is neces- sary, owing to the smallness of the field or wind condi- tions. But a pilot who gets into the habit of making side-slip landings is guilty of lazy flying. “ DARNSTORMERS,” Enslow argued, “learn to land on a dime. And in barnstorming, you're taking off and landing every five minutes, in all kinds of weather, usually with a ship that should have been on the junk pile a year be- fore. You learn to fly anything—any where—any time.” Enslow is a graduate of the barnstorming school. He and Lindbergh were barnstormers before Lind- bergh went into the air mail. I am so convinced that barnstorming is the best way to learn flying that I am seriously con- sidering going into it as soon as I have my limited commercial license. It is an excellent way to pile up hourage, and Enslow says there is still fair money to be picked up at it, in spite After it was all over, Enslow gave my shoulder a fatherly slap, and said: ‘‘Don’t worry, kid, you’re going to make a fiyer.’’ 45 of the increasing number of airports with their resident flyers. The old Army flyers’ saying, ‘‘ Don’t use up your luck,” was much more appro- priate in the old days than it is now. Planes are so much safer than they used to be. There was a time when a pilot who found his ship in a tail spin had only one thing to do: pray for his soul. There was no hope for his body. In those days he wore no.’chute, and in those days a ship once in a spin stayed in the spin until it crashed. {OST modern ships are engineered with such perfect stability that they must either be fought into a spin or they will, of their own accord, pull out of a spin. The most advanced of modern ships will almost fly themselves. Many of them you can fly “‘hands off” for minutes at a time, provided the air isn’t too rough. I have been in a Ford-Stout loaded with twelve passengers when the pilot—I sat beside him—had his hands off the con- trols for almost five minutes. Many flyers believe that the time will soon come when, with gyroscopic stabilizers, a plane may be set on a course and will hold it without attention from the pilot for hours. It will do practically everything itself but take off and land. The plane in which Enslow and I did the tail spins had duplicate controls. We did not use the speaking tube. In fact, we had been using it less and less lately. A gesture to the right or left meant a right or left turn; a thumb jabbed upward meant climb; downward meant glide. If I wanted to attract his attention, I flapped the ailerons or wabbled the rudder

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es —_ ee 4 | Ht nf ae } i ! N | i H Hy 1 i / _——-- I asked Enslow as we walked over to the ship that morning if he liked tail spins. He answered with one of those vague looks. I had asked a foolish ques- tion. No flyers, with the possible excep- tion of the stunt men who are a law unto themselves, like tail spins. The spin has a bad reputation. As far as I am con- cerned, it de- serves a much worse reputa- tion. CLIMBED our ship that morning until the altimeter read 2,500 feet. Then Enslow took the controls, cut the motor, and shouted: “‘Hey —safety belt?” Mine was secure- ly buckled. I nodded. He climbed to about 3,000 feet. Again he cut the gun and shouted: “Hey—a loop!” The nose went down. The speed of the motor increased audibly. Back came the duplicate contro! stick between my knees. Up went the nose. The horizon dropped out of sight. I was then conscious of a sensation as if my brains were rushing to the front of my skull. The safety belt pulled against my waist. Looking straight up, I saw the ground flashing by. Then the horizon came back to where it be- longed. Enslow did other stunts—wing overs, vertical banks, side slips, a roll out of another loop—trying out the ship’s re- sponsiveness. He climbed to 4,000 feet and cut the gun. He shouted above the singing of the wires: “Hey!—Spin! Hang on, kid!” Enslow helping me into parachute harness. The chute is neatly packed in the seat-cushion bag. E PULLED the nose up almost . straight into the sky, then threw her over on the left wing—and we were in it! I want to say again that everything bad I have ever heard about the tail spin has been an understatement. The terror of the tail spin simply cannot be exaggerated. But I wish to correct one popular mis- conception. A tail spin does not mean that a ship is spinning toward earth tail down. The tail is up—way up— and revolving madly. The nose is also revolving madly, but point- ing straight down. In that spin- ning condition, the ship plunges toward earth. A. spin starts loosely—that is, with tail and nose describing fairly large circles. Then the spin be- gins to “tighten up”; the circles cut by the revolving nose and tail grow smaller and smaller. The ground was reeling, spin- ning, whirling. Unless you have been in a tail spin, nothing I can say will help your imagination to grasp how rapidly and in how many directions the ground was whirling. In tight turns, I have * time I took the controls. POPULAR SCIENCE MONTHLY seen the horizon go past the nose of my ship at 1,200 miles a minute! A good reporter might be able to describe his sensations during a spin. I cannot. There was only the sensation of that horrible whirling and the sound of screaming wires as we shot toward earth. From start to finish, it lasted only five or six seconds. Suddenly the ground ceased whirl- ing. We were in a straight dive. I glanced at my altimeter. It had read 4,000 at the beginning of the spin. It now read 2,800. We had lost 1,200 feet. We lost another 200 feet in the dive, then Randy pulled her out of it. He cut the motor long enough to shout: “‘Hey! Grab her! Climb!” I took the controls and climbed. I felt a little uneasy in the vicinity of my breakfast. I have made references to my stomach in previous articles— how it shrank and protested the first But more and more recently it had become “air minded.” Now it was back at its old tricks—shrinking, quivering, objecting to the prolonged insult of that spinning dive toward earth. My hand on the stick was none too steady. This time I was to put her into the spin; and this time I was to pull her out of the spin. Could I do it? I kept my eye on the altimeter. The A side-slip landing, illus- tna, trated here, sometimes is necessary where the field is too small for a straight glide landing. NORMAL COURSE S PLANE IN STRAIGHT & “~~ FOR LANDING PLANE LANDING ae WIT WIDE MARGIN 4 OF SAFETY Randy showed me how to pull the rip cord to release the parachute. With right hand, grab a ring at your left side, and yank. Right: Hooking the last strap. GLIDE ~ No SPACE, INSUFFICIENT a : another spin—a reverse spin! Aucust, 1929 needle crept from 3,000 to 3,500. When it reached 4,000, Randy cut the motor. “Hey! Spin her!” I spun her. I did what he had done. I pulled back the stick until the nose was well up. The moment she stalled, I cut the gun and pushed the stick to the left. The left wing went over and down. The nose swooped down. Click! Snap! Who-o-oosh! We were in the spin! r HAD been so easy! Some ships, I have said, must be fought into a spin. Time after time, you pull up the nose until you stall, then push the left or right wing over. And time after time, the ship will slip out of that position into a straight dive—but not a spin. And once that type of ship is in a spin, it is just about as hard to get her out. You fight them in and you fight them out—and sometimes you cannot fight them out in time! Then the newspapers have another piece of bad fiving news to spread all over the front page. The ship we were flying that day went into a spin almost too easily. It snapped into it. And again we were plunging down, tail up, and the earth was a horrible swimming confusion. And suddenly I could understand why students freeze onto the con- trols in tail spins. To pull out of the spin you must do exactly the opposite of what your common sense tells you to do. You are diving straight down at the earth, aren’t you? And to pull out of a dive, you pull your stick back, don’t you? Yes—to both questions. But to pull out of a spin, you do not pull the stick back. You gently push it forward! At the same time you kick your rudder and hold it against the direction of the spin. T WAS. prob- able that Ran- dy Enslow had the pyrene in his hand, ready to slug me on the head if I made the wrong ma- neuver. Many a time has the fire extin- guisher been used on a frozen student in a spin. I want to say again that instruc- tors are among the greatest unsung heroes of the air. But I kept my head, and presently we were no longer spinning. We were in a straight dive. It was then that I went into my third spin, the one I had no in- tention of going into. Although we were in a straight dive, the universe was still reeling. I pulled out of the dive. In doing so, I pulled out too far. Up went the nose, over went the right wing—and down we went in I had heard about these reverse spins—how students, even trained flyers, are (Continued on page 134) nen see ae EO a ea a ee — i nwa. on ae ee ee eee

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Oma Bmw OD OP oF we OF OP = ~ oF ~~ ( et hee OS —cr or US w 8 aS eS ed ee ee ee ee * Owe aS t+ ~~ 6S oc == ty ‘ or wf te on oe Aveust, 1929 Dr. Fredrik Vogt with scale model of Stevenson Creek experimental dam. It was made of materials taken from the site of the actual structure, which is pictured at right. N A basement room at the University of Colorado, Boul- der, is alaboratory unlike any other in the world. There en- gineers build and break little dams —exact replicas in miniature of the mighty water barriers of western states. From these scientific toys they are able to calculate accu- rately the capacities of the real dams and to safeguard the lives and property of valley-dwellers in irrigated regions. A noted association of research engineers, the Engineering Foun- dation, with headquarters in New York City, in conjunction with the U. S. Bureau of Reclamation, is conducting the tests. So suc- cessful have they proved that the Foundation predicts that models and mathematics will go hand in hand in planning all future dams, and the Bureau, not long ago, set aside a fund of $20,000 to carry on the work. In the past, model dams of rubber and of celluloid have been used in tests. The diminutive barriers of the Boulder laboratory, however, are made of the same material that goes into the large structures. Dirt and bits of rock have been transported as far as a thousand miles for this purpose. Not only is the material in the model similar to that in the real dam, but hundreds of painstaking measurements insure that the model is’ built exactly to scale. HEN the little arched walls are completed, miniature floods of heavy mercury, or water contained in rubber bags, press against the “upstream” face in a testing pit. Against the ‘“down- stream” face, a battery of needle-pointed rods, connected to delicate recording instruments, touch the surface and measure the slightest ulge. Even closer watch is kept upon de- flections in the model by POPULAR SCIENCE MONTHLY Toy Dams to Save Lives By ARTHUR A. STUART an amazing instrument, an optical strain gage which notes variations down to one millionth of an inch! The first model made at the Boulder laboratory was a scale reproduction of an experimental dam built, not long ago, by the Engineering Foundation in a wild ravine in the mountains near Fresno, Calif. Known as the Stevenson Creek Dam, it was designed to see how thin a sixty-foot-high arch dam could safely be made. Only two feet thick, it showed A dam at Lawrence, Kan., giving way before the rushing flood waters of the Kaw River. It is to prevent such disasters that the tests descrited here are devised. feet when 47 The Stevenson Creek experimental dam, built by Engineering Fcundation near Fres- no, Calif., to deter- mine strength of walls. surprising strength, holding back water that rose until it overflowed the top. The model of this dam, made on a scale of an inch to a foot, underwent 250 load tests before it broke. A scale replica of the Gibson Dam, a_ Reclamation project on the Sun River, west of Great Falls, Mont., is now under test in the unique Colorado “proving ground.” NE of the experts experiment- ing with the models is Dr. . Fredrik Vogt, of the. Norwegian Institute of Technology. Before . coming to America, he made elaborate tests of the weak points of different-shaped dams, by molding models of rubber, sim- ilar to that used in erasers. At Princeton University, New Jersey, Professor George E. Beggs is noted for a series of models made of celluloid. A remarkable one-fortieth-size reproduction of the Steyenson Creek structure in- dicated capacities that almost exactly tallied with the results ob- tained from the finished) dam. At present, Professor Beggs is at work upon two models of this sixty-foot dam asit would appearif it were eighty feet and a hundred feet high, respectively. Tests upon them are expected to reveal to what height the thin concrete wall could be built before it would give way under the terrific strain of water piling up behind it. The cost of determining this by increasing the dam’s height would be more than $50,000. Knowledge gained from tests of. this kind is proving valuable in two great proj- ects now under way. A concrete dam that will be a foot higher than the present record-holder, the Pacoima Canyon structure of southern California, de- scribed in the May PorputaR SCIENCE Montu_y, is being built on the Skagit River in the state of Washington. When completed next spring, it will stand 386 feet high and form the heart of a $30,000,000 hydroelectric project un- der construction by the city of Seattle. The neighboring state of Ore- gon will soon eclipse this record. On the Owyhee’ River, _ the Government is build- ing a gigantic wall of concrete to rise 405 finished.

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48 Back o By KARL VOOGHT NEW type of canal barge, the motive power of which is supplied by a detachable outboard gas- oline motor instead of by the old-time horse or mule, docked at London, England, the other day after a successful 147- mile run from Birmingham. The 1929 model barge has an electric klaxon horn and headlight. A dis- tant cousin of this craft was put into service recently along the waterways of the 600,000-acre delta section of northern California. It is the world’s first floating filling station—a steel tanker designed to supply the gasoline and lubricating oil needs of the farms of that dis- trict, which can be reached only by waterways. The appearance of the motor- driven barge would indicate that the train, the motor truck, and the POPULAR SCIENCE MONTHLY Aucust, 1929 ’s News source to the observer. Later the famous physicists, Fizeau and Fou- cault, devised mechanical methods of making accurate measurements of the speed of light. R. MICHELSON, who is now seventy-six years old, began his studies in this field in 1880, when he found that the velocity of light was 186,360 miles a second. These tests he repeated in 1883 with the aid of Professor Morley principally to prove the existence of ether, considered a necessary medium for the transmission of light waves. It was upon the neg- ative results of these tests that Einstein based his original rela- tivity theory, in which the exist- ence of the ether is denied. In 1926, Dr. Michelson corrected his earlier findings and placed the Good-by mules! The lat- : yy, est in canal boats, pro- ' if pelled by outboard motor, : / in London after 147-mile run from’ Birmingham, England, in fifty hours. commercial airplane have not yet made the canal obsolete as a means of transportation. Although, in this ‘country at least, most freight is shipped by train and truck, the great eanals are still extensively used for leisurely and inexpensive transmission of goods. As recently as 1903, a sum of $101,000,000 to rebuild the Erie Canal so it might accommodate barges of 1,000-ton capacity and more was authorized by popular vote of the citizens of New York State! And as late as 1914, the Cape Cod Canal from Barnstable Bay to Buzzard’s Bay, Mass., was opened, cutting off 100 miles and the most dangerous portion of the assage between New York and Boston. The Chesapeake and Ohio Canal, the Illinois and Michigan Canal, and the IIli- nois and Mississippi Canal, to mention only a few, also are still largely used. HE first American canal was dug in Orange County, N. Y.,in 1750, forthe transportation of stones. Work on the first real lock canal was not started until 41 years later. This was the Union Canal, from the Schuylkill River, near Reading, Pa., to Middletown on the Susquehanna River, which was finished in 1827. George Washington was the father of a plan for a great interstate system of canals, to connect the Great Lakes with the Atlantic. His original scheme to ex- tend the Chesapeake and Ohio Canal to Pittsburgh and from there to Ashtabula at Lake Erie was postponed on account of the tremendous cost. Had it been car- ried out, Baltimore, Md., might have grown to the size and the importance of New York City. The Erie Canal, connecting New York with Lake Erie, was opened from Buffalo to Albany in 1825 with a total length of The first floating “filling station”’ delivering 500- pound drum of gasoline for farmers on a river in northern California. 325 miles. It reduced the time of trans- portation over this route from twenty to ten days and freight rates from $100 to $3 a ton! Incidentally, it will be remem- bered that President Garfield, when a boy, drove mules hauling barges along the Erie Canal. Vacuum Tube a Mile Long R. ALBERT A. MICHELSON, dis- tinguished University of Chicago physicist, whose measurements of the velocity of light are accepted as the last word on the subject, recently announced his intention of reducing or possibly eliminating the slightest error in his pre- vious figures by making the amazing new test of reflecting a beam of light ten times back and forth through a vacuum tube a mile long! That light travels with a speed of about 186,000 miles a second was discovered through observations during eclipses of Jupiter's moons by the Danish astron- omer Olaus Rémer as early as 1675. Until that time it was believed that light re- quired no time at all to pass from its velocity of light at 186,284 miles a sec- ond. This figure he reached after an in- genious experiment on top of Mt. Wilson in California. Here he set up a powerful arc lamp and a rotating octagonal mirror, an adaptation of the method used by Foucault. The latter.apparatus worked like a spinning top of eight-sided shape with a mirror in each of its eight faces. On another mountain, twenty-two miles away—San Antonio Peak—he placed a stationary mirror. A ray of light directed on the rotating mirror from the arc lamp was shot across to San Antonio Peak, where mirror No. 2 promptly cast it back to the rotating mirror on Mt. Wilson. Knowing the speed of his spinning mirror, Professor Michelson thus was enabled to calculate the fraction of a second it had taken the light to travel the forty-four miles from Mt. Wilson to San Antonio Peak and back. In round numbers, the trip took 1/4,200 of one second! — mind can scarcely conceive this terrific speed. In the time it takes you to blink your eye light travels fast enough to go around the earth—25,000

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Avueust, 1929 miles—seven times. Yet this distance is so small compared to interstellar spaces that the light now reaching earth from the nearest fixed star, Alpha Centauri, started almost four and a half years ago! Following his 1926 experiment, Dr. Michelson said that it had made possible the measuring of light velocity with only one mile of error a second! Close as this was, the scientist was not satisfied. He knew he could obtain even greater ac- curacy by increasing the length of the path over which the light is made to travel. So last year, he repeated the test, attempting to send the light from Mt. Wilson to a peak about 100 miles away and back. However, the air was not suffi- ciently clear to obtain a satisfactory image and the experiment was aban- doned. It was then that Professor Mich- elson determined to de- vise a new test, which would eliminate such fac- tors as temperature, hu- midity, and air pressure. Hence, the vacuum tube! Refine Ore with Thunderbolts MAN-MADE thun- derbolt of 3,000,000 volts, hurled across a thir- teen-foot gap, recently was put to work refining ores by a California min- ing company. When Hec- tor M. Hassell, inventor of the lightning machine, throws the switch, a giant tongue of fire and death streaks through the air, its unleashed power destroy- ing life and disintegrat- ing solutions in its path. This spectacular experiment of separat- ingmineral solutions by means of harnessed lightning interests us all. It suggests again the possibility that future scientific Joves may hurl their superbolts to smash atoms and realize the dream of the Middle Ages, the transmutation of metals, or send their giant sparks as “death rays” in time of war to blow up battleships or wipe out cities. About five years ago, an Englishman, H. Grindell Matthews, arrived in this country with the claim that he had _ perfected such a death ray. He showed moving pictures of his device killing instantly an animal sixty-five feet away and blowing up a motorcycle. He said that by increasing the power he could bring down planes from the sky or stun the populations of cities so they could be easily taken in time of war. O* HIS return to Eng- land, he announced that he had disposed of his invention to an Amer- ican concern, but nothing has been heard of it since. During the World War, & report was circulated that a German had invented an electrical POPULAR SCIENCE MONTHLY Three-million-volt thunderbolt machine, exhibited by John T. Martin, president of the California mining company which is put- ting its harnessed lightning to work re- fining ores. Left: A photo of the tongued streaks of man-made lightning discharged by the apparatus. ray that could short- circuit the motors of planes flying overhead. It was never confirmed. High tension elec- tricity has been applied before — usually in voltages under sixty thousand—to break- ing down chemical solutions into their various elements. * In the laboratories of the Carnegie Institution, in Washington, D. C., and of the General Electric Com- pany, in Pittsfield, Mass., 5,000,000-volt “guns” recently gave awe-inspiring exhi- bitions of their power. Whether these thunderbolts of the laboratory will ever burst open the atom and allow science to create metals at will is a fascinating conjecture which only time can answer. Two photos of a slate grinding mill, illustrating effectiveness of electric “precipita- tor’’ in preventing dust. They show the dust collector working and not working. 49 Cleaning the Air of Dust THE trillion cubic feet of air which New York City’s inhabitants breathe, there are 2,100 tons of dust— on a clear day! This staggering quan- tity is enough to cover an area the length and width of a city block with a pile high enough everywhere to bury a@ man standing upright. When the wind blows, even more dust is stirred up, aceording to Prof. H. H. Sheldon, of New York University, who declares these the first definite figures ever obtained on the actual amount of dust in the city’s air. R centuries the pollution of air in great industrial centers has been recognized as an evil. Perhaps the first recorded protest against it was that of Queen Eleanor of England, who in 1257 refused to live longer at Nottingham Castle because of ob- noxious black smoke from the village below. She went off in a huff to live at Tutbury Castle. Edward the First of England, in 1307, issued a proclama- tion prohibiting coal burning in London because of the “sulferous smoke and savour of the firing.” It is said one man was hanged for persisting in burning coal. If smoky-chimney offenders are less summarily dealt with today, it is not be- cause their offense is minimized. Dust alone is a prolific source of asthma, medical authorities say; but probably its greatest danger is as a carrier of disease germs, of which countless numbers may ride on a single dust particle. A test plate exposed for five minutes in a typical New York apartment: after sweeping collected 2,700 bacteria, as compared with 225 in a model hospital. Another source of danger from dust is that it screens out the ultra- violet health rays from sunshine. HAT is dust? Usually minute parti- cles of soot, fibers, vegetable matter, molds, varying in size from the cinder that gets in your eye to particles so minute that they may remain in the air, wind-borne, for as long as two years! What can be done about it? The first step, which health departments of many cities are taking, is to see that stoking of boilers and furnaces is done intelligent- ly, to prevent excessive smoke. An air-cleaning campaign of this kind conducted by the U. S. Bureau of Mines resulted in a ninety-five percent reduction of soot in the business section of Salt Lake City. Prof. Sheldon foresees that it may be necessary to install in apartment house chimneys electric devices to abstract the soot from outgoing gases. Such “electric precipita- tors” are based on the discovery of Dr. F. G. Cottrell, of the University of California, that metal plates highly charged with as much as 600,000 volts of electricity will gather solid particles suspended in air or gases. Smelters

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50 have installed them as a boon to farmers in the neighborhood, whose fields were formerly ruined by soot and fumes; and they have been applied to dust removal in cement and slate milling plants, tar re- moval in gas manufacture, and the re- covery of precious metals that otherwise would go up the flues in refining plants. A Poor Shot Led to Tinless Tin Cans LAZY helper tossed a box of chem- icals. It landed with a plop in a 100-pound pot-of- molten aluminum. Thus wac born a secret alloy. Now, with the recent invention by its dis- coverers of a way to electroplate it on iron, it may revolutionize at least one major industry. “Tinless tin cans” for food and to- bacco, made of the cheap new alloy, are said to threaten the long-held supremacy of the old-fashioned tin can. Other uses are seen for the alloy in airplane metal, and as a substitute for expensive chromium plating on auto radiators and bath fixtures. These fascinating vistas are opened by the discovery within the last year of a way to plate the alloy. But for eight years it has awaited use. Its romantic story starts in a Chicago workshop where its co-discoverers, Major A. Messlein and Edward L. Girard, Chi- cago engineers, were preparing a “melt” of aluminum to make a light engine. A 100-pound pot of molten aluminum stood in the room. Girard called to a small colored boy, a helper, to pass him a wooden box, filled with assorted chemi- cals, to modify the batch. Instead, the boy tossed the box to another assistant who was nearer. He missed the catch. Into the pot of aluminum went box, chemicals, and all. “Seventy-five dollars gone!” Girard exclaimed, looking rue- fully at where the chemicals had vanished in the “spoiled” batch. UT it wasn’t spoiled! Fragments of the metal that had slopped over the side of the pot and solidified behaved less like aluminum than any metal the experi- menters had ever seen. Tests of samples proved it was more like steel in strength. It had two other important features; it didn’t tarnish or corrode, and, unlike aluminum, it could be soldered—a netes- sity. for instance, in can-making. Could they duplicate the lucky acci- dent that gave them the mixture? Luckily the experimenters knew what was in the box, and were thus able to produce the alloy intentionally. For it defied analysis! Prominent chemists, and even the U. S. Bureau of Stand- ards, Girard says, could not tell them what was in it. Chemists of rival corporations, who might have given much to know of an aluminum alloy as strong as steel, confessed they could not detect the mystery metal’s ingredients. The experimenters freely gave away samples of the secret alloy—a silvery, light metal. It contained, they readily admitted, ninety-five percent of alumi- num—and four other vital and secret ingredients. Try to find them! They knew that if they could find a way to plate the alloy upon iron they would have a valuable substitute for tin. How- POPULAR SCIENCE MONTHLY ever, prominent chemists assured them— for a fee—that it was impossible, first to plate an alloy at all, second, to plate any- thing containing aluminum, and, third, to plate anything but copper with elec- tricity upon iron, to which tin is applied in the manufacture of tin cans. Notwith- standing, Messlein set to work and eventually succeeded by himself, Girard Machine used in the remarkable process of electroplating the new secret alloy on iron. says, in performing all three of the “im- possible” feats. He plated his alloy on iron. The first of several plants which will use the new process is now operating. Sample cans made with the new metal have shown no deterioration nor injured food placed in them for test, Girard says. Why Metals Grow Tired BRIDGE in New Jersey recently col- lapsed for no apparent reason. Its beams, girders, and other steel parts ap- peared to be in excellent condition and gave no warning of the impending crash. Following an investigation the most ac- ceptable theory was that metal fatigue caused the catastrophe. Metals get tired, just as, animals do; A remarkable photo of hardened steel, highly mag- nified, showing deposit of ferrite (light streaks). Such deposits may cause fatigue of the metal. Aucust, 1929 there is no way of preventing it except by resting the metal. That is the astonish- ing statement of Prof. J. B. Kommers, of the University of Wisconsin. When metal gets tired, it may break—some- times at a wholly unexpected moment. A motor bus that carries forty passen- gers in the rush hour may wait until it is returning to the garage late at night to snap an axle. It seems as if minor jars, repeated many times, are more likely to make metal break than a few rude shocks. For some seventy years, metallurgists have been trying to find - out why. ERMAN experts tackled the prob- y lem first, but without conclusive results. Then Prof. H. F. Moore, of the University of Illinois, devised a way to subject metals to 100,000,000 shocks in the laboratory to observe its behavior. From microscopic. ex- aminations during the tests it appeared that metal failure starts when one of the microscopic steel crystals that compose it is cloven in two by local pressure and its broken parts, seen as separated by a line across the crystal, slip upon each other. When the shocks are continued the slipping spreads to other crystals and widens into a definite crack. Then the piece breaks. Later tests showed that local stresses causing fatigue are intensified when the metal is not of uniform structure. And this may not necessarily mean flaws are present; for there are a number of differ- ent varieties of crystallized steel, such as pearlite, ferrite, and austenite, of which a single fragment of metal may be com- posed. Remarkable high-power photo- micrographs recently obtained by the Bell Telephone Laboratories show vividly the streaks of different steels which may cause fractures to start. Corrosion may also result in fatigue and breaking, says R. J. McKay, New York metallurgist. While the mystery of “fatigue” in metals is gradually being cleared up, practical tests meanwhile help to remove its menace. In the University of Illinois engineering laboratory, tests have been developed that, in a few days, subject a metal part to as much wear as it would normally receive in a lifetime. Another safeguard is a method of X-ray examina- tion developed at the Massachusetts In- stitute of Technology that reveals flaws before they become dangerous. Facts about Poison Gas in Cleveland Tragedy OSPITAL patients and heroic physi- cians and nurses who sought to res- cue them—123 persons in all—were killed by poisonous fumés from burning X-ray films that exploded in a basement stor- age room of the Cleveland Clinic Foun- dation some weeks ago. In addition to these victims, at least fifty more were made severely ill. Although its heavy death toll deeply shocked the nation, the disaster might have been much more appalling in its results. Experts who have since investi- gated its causes state that the 75,000 pieces of burning nitrate photographic film generated about 1,000,000 cubic feet of gas, enough to kill 4,000,000 persons— the population of greater Chicago! ee wn

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a es oe || ——— Aucust, 1929 About thirty percent of the deadly gas, the experts say, was nitrogen oxide, a red- dish-brown corrosive gas closely related to nitric acid; another thirty percent was carbon monoxide, the same colorless, odorless gas that has killed many persons in closed garages where automobile en- gines had been allowed to run, and the remaining forty per- cert was harmless. The fatal effect of large quantities of nitrogen oxide or earbon monoxide may be imagined by realizing that one part of either in 100 parts of air is deadly! So strong were the poisons that coroner's as- sistants, performing autopsies at the morgue, were over- come by the fumes arising from the vic- tims’ bodies. HILE most of the victims . died as a result of inhaling nitrogen oxide and carbon mo- noxide, analyses of the blood of others showed the effects of hydrocyanic acid and bromine gas. This indicated that different chemical conditions were created at the same instant in various portions of the four-story building. What really happened was that the clinic, from cellar to roof, until that blew off, was converted in about half a minute into one gigantic chemical retort, with many chemical reactions going on at once, unstable organic compounds build- ing up and breaking down in quick suc- cession. These fatal chemical reactions occurred in rooms and corridors, and even in the lungs and bloodstreams of persons inhaling the gases. HE cellulose nitrate of which the X-ray films were made is virtually identical in composition with smokeless powder. When this material burns, three forms of nitrogen oxide result. At first, nitric oxide is given off. Composed of equal parts of nitrogen and oxygen, this is the harmless “laughing gas” adminis- tered by dentists. But on contact with the air, it oxidizes to the deadly nitrogen dioxide, composed of one atom of nitro- gen to two of oxygen. :The third form of the same compound is nitrogen tetroxide, containing two atoms of nitrogen and four of oxygen. Nitrogen dioxide mixed with water is nitric acid. The report of the experts recommended that, to prevent recurrence of catastro- phies of this character, inflammable films in all clinics and hospitals be stored in separate steel or other fireproof cabinets. New Grand Canyon Bridge REMARKABLE new steel highway span, bridging the Colorado River at Marble Gorge, northwestern Arizona, was opened to automobile traffic recently with officials of Arizona and Utah par- tcipating in a two-day celebration. Over this 616-foot bridge, 500 feet above the charging water of the Colorado, POPULAR SCIENCE MONTHLY yt, The completed steel highway bridge across the Colorado River, Marble Gorge, Ariz. Left: The 834-foot con- crete roadway supported by the high span. machines wili speed into picturesque country hitherto inaccessible to motor- ists. For millions of years the river has been digging the Grand Canyon of the Colorado. Only now have the two sides of the chasm been linked by a solid road. Once upon a time, the plateau, through which the canyon cuts, was ocean bottom. Gradually, through geologic ages, it rose above the water. The belief is that the turbulent water of the river, draining a guarter million square miles of territory, How Much De You | Know about Timepieces? EST your knowledge with these questions, chosen from hundreds asked by our readers. You will find a list of the correct answers on page 137. 1. Is it bad to turn the hands of a watch or clock back- ward? 2. What is meant by adjust- ing a watch for positions? 3. What is the difference be- tween a pocket watch and a chronometer? 4. Is there any watch that will keep perfect time? 5. How does a stop watch work? 6. What is ‘“‘railroad accu- racy”’ in a watch? 7. How was time measured before they invented clocks and watches? 8. What is isochronism? 9. What advantage has a pendulum clock? 10. Why is the day divided into two periods of twelve hours, with sixty minutes in each hour and sixty seconds in each minute? 51 4 P: yn a7 7 cut down as the land rose, in the manner of a saw biting into a log lifted against it. The “sawdust” from this cutting, the silt of the worn-away rocks, spreads out be- low the canyon forming the rich soil of California’s famous Imperial Valley. In some places along the 283 miles of the Grand Canyon its depth is more than a mile. Its width varies from a few hun- dred feet to twelve miles. Much of the wild gorge still remains unexamined. On either side, the walls stand like mile- thick books lying side by side, the layers of rock forming the “leaves.” Victim of the Rattler FTER handling poisonous snakes for twenty years as head keeper of mam- mals and reptiles at the Bronx Zoological Gardens, New York, Charles E. Snyder died a few weeks ago from the effects of a rattlesnake’s bite while hunting in the hills near Suffern, N. Y., for specimens with which to enrich the Zoo’s collection. Two injections of serum, used with great success in numerous previous cases, were administered to Snyder in vain. The ex- pert, confident that his experience would enable him to cope with the emergency himself, apparently applied too late for the serum treatment. Snake-bite antitoxins are a compara- tively recent development. The first serums were obtained in experiments some thirty years ago at the laboratories of the Pasteur Institute, Lille, France, under the direction of Dr. A. Calmette, famous authority on snake venoms. At that time, the annual death toll from snake bites throughout the world was appalling. In British India alone, they were responsible for about 25,000 deaths in one year! HE poisons used at the Pasteur labo- ratories were imported from Cochin- China. Here representatives of the Insti- tute studied the methods of the so-called “‘snake-charmers” and found that they did not hypnotize the reptiles but im- munized themselves to their bites by self- inoculations! with minute quantities of venom. The Frenchmen brought the poison, extracted from the cobra, most venomous of Asiatic snakes, back to the Institute. There, by mixing the poisons from several species of reptiles and experi- menting with the mixtures on horses, the antitoxin was de- (Continued on page 134)

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52 POPULAR SCIENCE MONTHLY August, 1929 At the Throttle of the “Big Hog" A Thrilling Ride in the Cab of a Crack Mountain Locomotive HE two-hundred-ton mountain- ype locomotive Philip E. Thomas waited in the railroad yard- at Keyser, West Virginia, to couple onto the Baltimore and Ohio’s crack New York-St. Louis flyer, the National Limited. It waited to pick up a sleek string of Pullmans and haul them westward over the West End of the Cum- berland Division—up the far-famed Sev- enteen-Mile Grade, the longest heavy grade in the East; over the 2,628-foot “hump” of the Alleghenies near Alta- mont; at last down the Cheat River Grade into Grafton on the far side of the moun- tains—eighty miles of the most spectacu- lar railroading east of the Rockies. Outside the cab the wind whistled bleakly between waiting box cars and coal-laden gondolas. Ahead, green switch lights reflected wanly on the polished steel rails. In the cab everything was warm and cozy, if a trifle sooty. Old Man Grief was riding the rails of the Cum- berland Division that night. The Potomac River, swollen by three days of driving rain, had. over- flowed its banks; in its valley trains were feeling their way gingerly along rails that were un- der six inches of flood water; and No. 1, the National Limited, would be twen- ty minutes late pulling into Keyser. With a clear fire burning in the fire box, and the steam gage showing two hun- dred and twenty pounds pressure, there was time for a little chat. Engineer Jim Pugh—a stubby, solid man with a firm mouth and the keenest of eyes; a man who carries his forty-two years of mountain railroading lightly— settled comfortably on the leather-cush- ioned seat on the right side of the cab, glanced briefly at various illuminated dials, then turned a quizzical gaze on me and answered the question I had asked a moment ago. O, I don’t like riding in automo- biles,” he said. “Fifty miles an hour over the mountains in the cab of a fine engine like the 5501 ””—his gauntleted hand gently patted the bronze throttle— “with an all-steel train roaring along be- hind you, good hundred-pound steel rails under your drivers, and a white light Engineer Jim Pugh, a stubby, solid man with firm mouth and keen eyes— typical of the American passen- ger engineer. Sure of himself, com- posed, keenly alert—the right man on the job. “‘Clear blockf’’ called Fire- man Fazenbaker. ‘‘Clear block!’’ echoed Engineer Pugh, to avoid a mistake, shining on the signal mast telling you everything's clear in the block ahead— that’s nothing to worry about. But it’s different in an automobile—no rails to run on, no signals to warn you of danger, and nothing under you but a contraption pretty near as flimsy as the paper they write train orders on, and faster than a runaway freight headed for the Big Hole. “**Railroad service involves hazard’— the ‘Book of Rules’ says that, and the ‘Book of Rules’ always is right—but rail- road service doesn’t involve one tenth as much hazard as taking what they call a pleasure ride in one of those gosh- blamed Big, red-haired Fireman Fazenbaker stepped on a pedal protruding from the steel deck, the fire box doors opened with a clang, and the locomotive cab was By ARTHUR GRAHAME flooded with a ruddy glow. I noticed a broad grin on Fireman Fazenbaker’s soot- coated face, and as broad a grin on the face of Road Foreman of Engines Charley Schuh, my guide in this experiment in head-end railroading. In case you don’t know, a road foreman of engines is an official who spends most of his time riding over his division in locomotive cabs, checking up on the performance of engines and enginemen. REMAN SCHUH leaned over until his lips were close to my ear. ‘‘ That’s the way with most veteran ‘hogheads,’” he said. “Scared to death of automobiles. The ‘tallowpots’ are younger—most of them like to burn gasoline, and to kid the old fellows about it. What’s that? Oh, yes—an engineer is called a ‘hoghead.’ When they got to building locomotives bigger and bigger, the firemen had to work harder and harder shoveling enough coal to keep up the proper head of steam, so they got to calling an engine a ‘hog’ —a coal hog—and then an engineer a ‘hoghead.’ A fireman is a ‘tallowpot’— has been ever since the old days when they greased cylinders with tallow in- stead of with lubricating oil. But they don’t like those nicknames—they’d much rather be called enginemen.” “Hey, up there!” Seven feet below us on the stone ballast appeared a brisk little man whose brass buttons gleamed in the lights of the cab—Conductor Mohler. He swung himself briskly up the iron ladder, compared watches with Jim Pugh, handed him a train order, remarked “‘Here she comes” as an electric headlight glared back of the station, and briskly swung himself down to earth. Jim Pugh read the order with care, then passed it over to his fireman. Back of us a lantern waved in a small circle across the track—the signal to back. Our bell clanged softly. Jim Pugh reached up and swung the bar of the Ragonnet reverse gear, opened his throt- tle gently, and the 5501 backed down the track and coupled onto the waiting train without a jar. Air brakes were tested. Two short blasts of the shrill air whistled in the cab. Without apparent effort the 5501 leaned against the long string of steel Pullmans, and we moved smoothly ahead. N A moment we were past the tele- graph tower, out of the yard, and on the main line. Fazenbaker jerked at the whistle cord. ‘‘Hooo-hooo-ho-ho!” blared the 5501—fair warning for a grade cross- ing. Now we were moving faster. Under the cab the trailer wheels clicked ever more rapidly over the rail joints, fell into a definite rhythm, and seemed to sing Gettin’ outa town, gettin’ outa town, gettin’ outa town”’—the song of the rails that the real railroader never can forget.

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POPULAR SCIENCE MONTHLY 53 Aveust, 1929 #1 Along lonely moun- eyed his steam and water gages in- ae tently; now and then opened the : fire box door to peer at the inferno within. Now he stepped over to the ' left-side window, and looked out. My eyes followed his gaze. Far ahead, over the track, a white light gleamed on a signal mast. “Clear block!” called Fireman Fazenbaker. “Clear block!” came the answer from En- gineer Jim Pugh. i os re ay eh WAYING and rum- bling, the 5501 roared on through the night. “Why do both of us call the signals? Just to be on the safe side,” explained Jim Pugh. “Now, when I see a white light I know it’s white—if I ever get a ae . : to feeling doubtful about it, a ae i °: oo Ss . I'll stop running trains: But Jim Pugh was out of the cab oiling the loco- . ' és ; other engineers have seen red motive almast before its drivers ceased turning. . : lights, and have been just as sure as I am that they were white. A lot of those men aren't alive today—the next thing they saw was the rear- end markers of a stalled train ahead of them, and then it was too late to avert a collision. And, speaking generally, an engineer who smashes into a stalled train doesn’t live to tell about it—tons of wrecked steel and clouds of scalding steam see to that. But, to get back to the signals, two men are un- likely to think that the same red light is white, and that’s why it’s part of the fireman’s job to watch the signals, and to call them. If he calls a sig- nal, and the engineer doesn’t ‘iiwite,wuee oe SP HEL = 4 4 Pia F og na Oe * oS li repeat, it’s up to him to cross pe As e.. over to the right-hand side of The author, on the step of the big mountain-type locomotive the cab and see what's the Philip E. Thomas, says good-by to Engineer Pugh after a thrill- matter—more than one engi- Many and marvelous are the ma- pn hehe in the coh. Guanting Se See neer has died of heart trouble, chines built by man, but few are ch denn tn the clt-alahe cellvead. cestausent a Gan Cae, at his post, with his hand on more impressive or more complicated the .open throttle, and his than is the modern locomotive. Some- Jim Pugh leaned from the cab window, train rushing at full speed to glory. thing like 7,000 separate parts go into its _ his steady eyes on the right-of-way ahead, “Taking chances is the one thing that building, and nearly all of these parts his steady hand on the throttle. Sure of doesn’t pay in railroading. There are must be made and fitted with the careful himself, composed, relaxed physically and _ engineers who are in such a hurry to get precision of the parts of a fine timepiece. at the same time keenly alert mentally— somewhere that they run past stop signals It was not for nothing that Matthias the right man on the right job! to get there—but you won't find them Baldwin, first of the world’s great loco- Fireman Fazenbaker, calmly efficient, running good trains on good railroads. The most experienced engineers get the best trains—and the fel- lows who don’t get killed running past stop signals get fired before their seniority entitles them to run a real good train. “Looking back over the forty-two years that I’ve been railroading on _ this Cumberland Division —TI started back in 1887, as a call-boy in motive builders, spent his early years at a watchmaker’s bench! As the 5501 thun- dered on through the night I sat in the cab —the nerve center of this tremendous mechanism. Carefully shaded electric bulbs illuminated the dials of various instru- ments—steam gage, air pressure gage, water gage, speed in- dicator. Over on the righ ° Meme Peter Cooper opened the throttle and the Tom Thumb leaped into the lead as the directors B ght side Engineer cheered. One of the queerest races ever run, between locomotive and stagecoach, back in 1829. (Continued on page 1 42)

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If a drowning swimmer throws his arms about your neck from behind, like this, you can break the hold by grasping and twisting one of his wrists. Then you can duck down, holding the wrist, and come up behind with a hammer lock and have him in your power. Photographs by D. Warren Boyer EVEN thousand persons are drowned each year, according to statistics of - the National Safety Council, because no one cap- able‘ of effecting a rescue is at hand to avert the tragedy. The pictures on this page tell you what to do to save the life of a drowning person. The safest way to approach a struggling bather is from the rear. Otherwise, he may throw his arms about you in a death grip. One of the photographs shows how to escape such a grip. The method of bringing a rescued person ashore depends upon his behavior. If he is still struggling, the cross chest carry, POPULAR SCIENCE MONTHLY The cross chest carry—a good way to bring a struggling person ashore. Throw one arm across his chest to prevent interference with your stroke; swim on your side, supporting him on your hip. One of the most effective ways of keeping a drowning man's head above the waves while swimming to shore with him. Turn him on his back; then, placing both hands firmly under his jaws, swim on your back, using a scissors kick. After a little practice with these various methods of rescue, you’ll be surprised to find how easily you can tow even a heavy person through the water. It pays to learn. Aucust, 1929 To revive an unconscious person, stretch him out, as shown. Then press down and in on the floating ribs every four to five seconds. This will induce breathing. An exhausted bather who is not strug- gling may be taken ashore easily by this “tired swimmer carry.’? Have him float face upward with his hands resting on your shoulders. This will leave both your arms free and allow you to swim with the breast stroke and push him to safety. You can keep a struggling bather at arm’s length while towing him in by pulling him along by the hair, face upward. This may look like an inhuman method of res- cue, but it is one which may save your life —and his. holding him in a position in which he cannot interfere with your swimming stroke, or the hair carry, towing him, face up- ward, by the hair, are best. If he is quiet, you can place both hands over his jaws as he lies on his back and, swimming back- ward, pull him to safety. Am exhausted bather, otherwise nor- mal, can be pushed to shore easily if he can float face upward and place his hands on your shoulders. Swimming with 4 breast stroke you can push him ahead of you. j Once ashore, resuscitation 1s accomplished, if needed, by 4 rhythmic pressure upon the floating ribs. Re yaa, —— of FOO OUD

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cen icons Aucusrt, 1929 NE of the strangest accidents that ever befell a model air- plane occurred over a field on the out- skirts of Chicago. Members of the Illinois Model Aero Club were tuning up feather- weight duration planes. ‘Two of the little machines whirred into the air side by side. They mounted in great circles lifted by updrafts under low- hanging clouds. When they disappeared in the clouds, they were never seen again! Repeated search of the vicinity revealed no trace of them. They seemed to have disappeared from the face of the earth. The theory is ad- vanced that after entering the clouds, they flew for many minutes in a straight line, and when their rubber mo- tors were unwound dropped into a field of tall weeds or among the branches of trees. The flight of a model air- plane is always an adventure. The unexpected spices it. No one can predict just what will happen. This is one of the reasons why, over the coun- try, the sport of flying miniature planes is_ being taken up. About 200,000 enthusiasts belong to the Air- plane Model League of Amer- ica, which held a national contest at Detroit last year and sent two winners on a trip to Europe. A second nation-wide contest was spon- sored by the National Playground and America. Recreation Association of Twenty thousand contestants local elimination meets, in which were chosen those sent to the finals at Atlantic City, N. J. Both organizations are holding similar tournaments this year, the League flyers meeting at Detroit and the Association con- testants at Louisville, Ky. At the latter meet, an Amelia Earhart Trophy is offered as a prize to the girl entrant who makes the best showing. EVERAL dozen companies in the United States now deal exclusively in supplies for little planes. Miniature aircraft are being constructed in schools as part of elementary courses in aeronautics. Every large city has its club of model building en- thusiasts. Summer camps and playground groups have model flying rallies, and in some cities, tiny hangars have been erected in POPULAR SCIENCE MONTHLY Bud Pearl, California contestant in Atlantic City model airplane meet, explains the fine points of his twin pusher to Mrs. Thomas A. Edison. Model Planes in Amazing Flights By EDWIN W. TEALE public parks to house diminutive machines entered in local meets. Of all the contest flights of last year, probably the most spectacular was that of a little rubber-band-propelled machine entered Just like a real ship—a featherweight rise-off-ground mono- plane taking off at the starting line in a distance contest. that started out to fly the Atlantic! Tudor Morris, of Peru, Indiana, entered the model in the Atlantic City tournament. Equipped with floats, it took off from a starting pool on the inland side of the city and, soaring high, headed over the build- ings for the ocean. Men of the Coast Guard in fast motor beats were called upon to follow it during its record- breaking twelve-and-a-half- minute flight. They found it, nearly a mile from shore, riding the ocean waves on its tiny floats. The previous duration record for a model airplane with floats had been two minutes and fifty-three seconds. IELD glasses are now part of the equipment of judges at important meets so they can keep the models in view as long as_ possible. What often happened be- fore this became the rule is illustrated by the hard-luck experience of Donald Shet- land. In a meet at Provi- dence, R. I., his fifteen-inch tractor was still flying when it went out of the judges’ sight, and what might have been a record could not be counted. Another racing model, launched at the Detroit meet by Joseph Lucas, veteran of the Illinois Model Aero Club, flew so far that it had to be hunted by an aviator in a real air- plane! Speeding away on a bee line, the racer passed over a stream and disappeared beyond trees and fields of high weeds. It seemed hopelessly lost. However, an Army airman at Selfridge Field offered to make a search. Taking off in a fast plane he roared back and forth over the fields beyond the airport until he sighted the glistening wings of the little machine amid tall weeds. He kept circling and diving over the spot until Lucas arrived and re- covered the model. wo all model flyers are as lucky. Thomas Hill, a six- teen-year-old boy from Winston- Salem, N. C., who won a trip to Europe at the same meet, never found his plane after its winning flight. To prevent the loss of valuable models during tests, many builders have started the practice of printiag their names and addresses on the little planes so finders will return them in case

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56 they fly too far afield. The amazing records set by the latest miniature machines have been made possible largely through re- duction of weight. Five years ago, a racing model three feet long, with a twenty-eight-inch wing and twin twelve-inch propellers, weighed from eight to ten ounces. Now the same machine can be built to weigh two and a half ounces. Refinement of detail and the wide use of lighter-than- cork balsa wood accounts for this striking advance. Equipped with the same amount of power as the heavier planes of the past, the modern thistledown eraft floats through the air to new records for duration and distance. Although wound-up strands of rubber re- main the standard motor equipment for record-making models, other sources of power are constantly being tested. At the Atlantic City tournament each of five different types of power was represented in a separate con- test. The most spectacular were the rocket planes. Some of them were ruled out, as they were simply Fourth of July skyrockets with flippers attached for wings! The craft that won the event was an ingenious little plane made by Burton Simcox, of Knoxville, Tenn. The “power plant” was a powder magazine stored in a drinking straw! A® escaping from a balloon propels a freak plane designed .by Wilbur Reitze, of Baltimore, Md. Just before the start of each flight, Reitze blows up a long balloon to which wings have been at- tached. Holding the combination craft aloft, he releases the mouth of the balloon. The air, escaping violently in one direc- tion, pushes the plane in the other! Ina model made by Virgil Rossner, of Peru, Ind., compressed air drives the pistons of a tiny motor that turns the propeller. In one flight, it stayed up seven and a half minutes. There are times when a diminutive aircraft will per- form evolutions in the air just as though some Lilli- putian airman were holding the stick in the tiny cockpit. For instance, when Frank Lauder wound up the R. O.G. monoplane (R. O. G. is an abbreviation of “rise off the ground”) which he made from instructions in PopuLaR Scrence MonrTuiy, and placed it on the ground near his home in South Norwalk, Conn., it made a regular “test flight.” Taking off after a short run, it banked in a wide circle to the right, came down in a _ perfect three-point landing, ran along the ground, and climbed again for a straight flight of more than 300 feet—all with one winding. The race is on! Launching a flock of speedy | models in tournament at Hawley Airport, Los Angeles, Calif. Right: A twin pusher model gain- ing altitude in duration contest at Atiantic City. 3 ei Pen eS Bees ee i me POPULAR SCIENCE MONTHLY Anotherstartlinginstance of a little plane piloting it- self occurred during an indoor meet at Detroit. Aram Abgarian, a fifteen- year-old contestant, had stayed up all night making alterations on a single “prop” duration plane entered in the Stout Trophy Con- test. When he launched the model in the great Olympia Hall, it climbed quickly to a height of sixty feet, avoiding steel girders near the ceiling, and at that altitude circled for more than five minutes. Then it began to descend slowly, as though trying to remain the last fraction of a second in the air. Although there was no evidence of drafts in the building, as the floating plane approached one corner of the auditorium, it banked, made a left-hand turn, and sailed along the wall to the opposite corner. There it banked again and, soaring close above the heads of spectators in the gallery, made a third right-angle turn and drifted to a perfect landing in the middle of the A trim model seaplane gathering speed for the take-off from starting tank at Atlantic City. From this tank Tudor Morris’ model made its record- breaking 12'4- minute flight out over the sea, as described in this article. Aucusr, 1929 floor. It had more than doubled the world’s indoor endurance record, its re. markable maneuvering dur- ing the glide accounting for many seconds. The thrills of flying model planes, however, are not confined to those who break records. Queer adventures often befall the little ma- chines built and flown by back-lot airmen. They add to the excitement of the sport. One of the most amazing was that of a model that kept on climbing after its main wing came off! Randolph Leach, of Mont- clair, N. J., had just launched his twin pusher and it was climbing at a steep angle when the rub- ber band holding the wing in place snapped. Instead of plunging to the ground, the machine, supported by the upward drive of §its propellers, kept rising for several feet. CARCELY less startling was the flight of the ““Shimmying Mosquito,” a single-propeller tractor monoplane made by Irving Blumberg, of Astoria, N. Y. In a take-off, the whirling blade struck a telephone wire, breaking the propeller in half. But, to the surprise of watchers, the machine kept on flying. Jerked up and down by the uneven pull of the screw, it shimmied through the air for more than a minute. Almost every new feat or innovation in big airplanes offers a challenge to the flyers of baby machines. When the mono- planes of the Byrd Antarctic Expedition were being equipped with skis, Wayne Brown, of Andalusia, Ala., replaced the wheels on his R. O. G. pusher with skis and accomplished some pretty take-offs from smooth stretches of trimmed grass. Stories of the feats of balloon-strafing aces of the aerial dog fight in miniature. Toy balloons were released as targets for “fighting models” —pusher planes with pins sticking from thefront. Each time a machine struck a bal- loon, the pin punctured it and another “‘enemy” plunged to earth. OW fascinating the sport of flying toy planes may become is illustrated by @ letter sent to an American supply company by a major of the U. S. Army, stationed in Hawaii. “This must stop,” he wrote. ‘“‘My son spends every cent he can get on models and accessories. Model flying absorbs all his spare time. He even neg- lects his studies to find time for it.” World War inspired a recent . FE ENEMA IN to ln ro: - ae a ee — byw +

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jor ist on et his 2B- me empEe Pear We = Auaust, 1929 POPULAR SCIENCE MONTHLY 57 ‘POPULAR SCIENCE. - 2 SCRAP BOOK * », N the following pages are presented a month’s record of invention, and brief bits about the new, interesting and unusual things people are doing in all parts of the world. Deadly Chemicals Purify City Drinking Water ’ ent A few of Croton. reservoir’s 1,800 fountains. They continually freshen the water with oxygen. the little animalcules that might cause disease. An elaborate system of pipes carries the evil smelling gas into the wa- ter, where it takes its toll of death-dealing germs. Attendants must wear gas masks when they work around these pipes, or they might suffer the same fate as did thousands of soldiers during the war. Sometimes the water in such reservoirs becomes bad-tasting, or has an obnox- ious smell, caused by a vegetable growth in the water. Chlorine won’t help this, but copper sulphate will, and so the lat- ter is poured into the water as it rushes through the pipes. Copper sulphate de- stroys the tiny plants, so that the water which reaches the household faucet is perfectly pure. You’ve noticed how flat water gets when left standing in a glass. The same thing happens to water kept in storage. So great fountains fling the water into the air and treat it with the oxygen that gives it life again. At the Croton reser- of its massive dam. But each day, be- voir eighteen hundred of these aerators, fore this water goes racing down to mil- a veritable “park of fountains,” help to lions of thirsty throats, huge quantities Rist husinshes Blesie geotect the. seen. whe make the water sparkling as any from of chlorine are used to attack and kill work around the pipes of purifying chlorine. a bubbling spring. Behind the massive Croton Dam can be stored thirty billion gallons of water for New York City. ADLY chlorine gas, one good whiff of which would bowl you over, is being used every day to safe- guard millions of lives by purifying the drinking water of our cities. Every drop of almost a billion gallons of water used every twenty-four hours in New York City has been made pure and healthful by this gas. A deadly enemy im one guise, yet—your best friend in another. Thirty miles from the heart of New York City the huge Croton reservoir holds enough water to supply the world’s argest city for more than a month. Thirty billion gallons can be stored back

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wu Builds Remarkable Scale Model of Coal Mine STRIKINGLY faithful miniature of A a Pennsylvania coal mine, built to scale and complete in every detail, in- cluding shafts, elevators, breaker house, railroad tracks and cars, lumberyard, and even a power house, has been constructed by Donald Tiffany, model maker of Bayside, N. Y. The photograph above shows him with his latest creation. It took Tiffany and his assistants three months to complete the model, every bit of which was carved, painted, and put together by hand. Tiffany considers the midget mine the finest thing he has made How the midget buildings are anchored by nails on wooden pedestals. Comparison with the hand gives an idea of their small size. in a long career, in the course of which he has turned out countless ship models, airports, Pullman cars, factories, houses, and entire real estate developments. When a young man he was a cabinet- maker, but turned to model making. An “Old Ironsides” as Small as Your Hand SURPRISINGLY small model of “Old Ironsides,” the doughty frig- ate Constitution, which won glory in the War of 1812, has been made by W. E. Haseltine, of Ripon, Wis. This gem of patient handicraft was built on a scale of one thirty-second of an inch to the foot. The length of the hull is six and a half inches —about an inch longer than the size of an average cigar! The usual ship- model scale is three times larger, one tenth of an inch to the foot. This is about as small as most people can do the job, according to Capt. E. Armitage McCann, noted mod- el maker whose articles appear in PoputarR Scrence Montu_y. In the tiny reproduction of “Old Ironsides,” fifty-two guns are turned of brass and mounted on rainiature mahogany Carriages. The dimensions of each are five thirty-seconds by three sixty- ‘fourths of an inch, and they weigh only one and a half grains apiece! In this connection, it is recalled that all the copper and brass for the Constitution was supplied by Paul Revere, who was an artist, an engraver, an iron- monger, a coppersmith, and—a dentist! The anchors on Haseltine’s model are made of steel with mahogany crossbars; they are three-eighths of an inch long and weigh two grains each. The tiny fife rails are fitted with steel belaying pins a hundredth of an inch in diameter! Old close-grain mahogany was used in building the little hull, but the masts and spars—the main mast measures five and a half inches from the deck—are from the spars of the famous old ship, and the double martingale, or dolphin striker, is made from a splinter of this identical part of the original Constitution, on a section of which the model is also mounted. Navy officials have requested the loan of the model for placing aboard the old frigate during a tour of American ports. Scale model of “Old Ironsides,’’ the hull of which is only six and a half incties long. W. E. Haseltine, the builder, is holding the small ship. The modei of the Con- stitution mounted on a portion of double mar- tingale of the original frigate. Masts and spars of the model are from spars of the original. The foot rule in the fore- ground gives an idea of the tiny vessel’s size. . Aucust, 1929 Philadelphia in Miniature, a $100,000 Toy City WONDERFUL relief model of the city of Philadelphia, covering a base eighteen by twenty-two feet, fills an en- tire room in the offices of the municipal department of Wharves, ‘Docks, and Ferries in the Quaker City. In meticulous detail, it comprises wooden miniatures of every building, street, sidewalk, bridge, and monument and even has tiny realistic representations of the trees, shrubs, and grass in famous Fairmount Park and Rittenhouse Square. Several projected great buildings, among them the new station of the Pennsylvania Railroad, built to scale from architects’ drawings, are featured also in the midget metropolis. The reproduction has been made on a scale of one inch for every 250 feet. As the tallest building in Philadelphia 1s the 548-foot City Hall tower, this means that the highest structure in the Lilliputian City of Brotherly Love is only a trifle over two inches tall. Still, every detail has been worked out carefully, down to the ventilators and even radio aerials. Work on the model was started in 1911, when the city zoning plan idea was first introduced in Phila- delphia, but it has been brought up to date by Heber James, a city engineer, who is seen above placing a wooden mimature skyscraper in the center of the city. The skyscrapers are all carved by hand and held in place by nails protruding from little blocks of wood. Pieces of painted sponge are used for bushes and grass, and dyed putty stuck on pins for trees. The model’s value is estimated at more than a hundred thousand dollars. Build a Model Helicopter N UNUSUAL article on page 81 of this issue tells how to build a re- markable helicopter model which has made a record flight of thirty-seven sec- onds. Included is a drawing of the hel- icopter toy which, in 1878, started the Wright brothers to- ward the invention of the airplane. Ba ahaa RETR GEE VD “ae

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ee CO ele ee ll — CD Oo — Der or OD DH ee wo Avueust, 1929 ‘Electric Eye”’ Turns on the Lights HEN does light get so dim you begin to strain your eyes? Human eyes can- not distinguish the exact point, but a supersensitive machine, designed by the General Elec- tric Company to turn on lights in schoolrooms, can! The light in the room falls upon a lens under which is a hoto-electric cell, that trans- lates light variations into cor- nding electrical varia- tions. When the intensity de- creases to a point where strain on the pupils’ eyes may result, the “light monitor” auto- matically switches on the lights by means of an electric relay. It determines infallibly when the button should be pressed. An automatic time clock disconnects the apparatus during hours when the school is not in session. Invents a Power Plant to Harness Small Streams MALL streams may be harnessed to generate sufficient electric current to light the farms of a neighborhood, if an invention by Frank L. Gaede, a filling station attendant of Plymouth, Indiana, realizes his expectations. His novel water power machine consists of a series of troughs carried on endless chains over sprocket wheels so they dip into the water at the upstream side and are carried back by the current, spilling the water on the downstream side. The wheels turn between two pontoons floating in cement basins, which keep them from moving on a horizontal plane but allow them to rise and fall with the water. Thus the height of the stream does not affect the operation of the machine. In tests with a model, with fourteen-inch troughs, the inventor found that a small movement in the water kept the wheels spinning. A large machine, he concludes, could be operated by a small creek to produce electricity for home consumption. Frank L. Gaede, of Plymouth, Ind., with model of water power plant he has invented to produce electricity from creeks. POPULAR SCIENCE MONTHLY Thrilling Whaling Scene Depicted in Model EMORIES of Herman Melville’s Moby Dick are evoked by a unique representation of an old-time whaling scene which it took J. H. Webb, of Los Angeles, Calif., two solid months to carve out and mount. The model con- sists of a miniature of a full-rigged three- masted New Bedford whaler, standing by in a choppy sea while part of her crew of twenty-two men, in a small whaleboat, await the death of a “‘sea beast” they have just harpooned. There are two other whales in the scene; one is depicted “ blow- ing” in characteristic fashion, and the other is swimming at full speed away from the fatal spot. Webb, seen above with his model, made the ship out of bits of wood and copper and mounted it on plaster-of- Paris waves, appropriately colored. The sailors and whales he carved of solder. He gained his skill at this handicraft by whittling done in leisure hours during a career of forty-five years at sea. The editor will be glad to supply, wherever possible, the names and ad- dresses of manufacturers of the vari- ous devices mentioned in these pages. wf be ~ Double-track model railroad with the new “joltless’’ rail crossings, demonstrated by the inventor, W. H. Whalen, of Los Angeles. Small turntables do the trick. 59 Perfumed Glue and Shoe Polish ERFUMING shoe polish and removing unpleasant odors from rubber goods are among some of the latest achievements of modern in- dustrial chemistry. Experi- menters in French industrial laboratories recently have made glue smell like violets and axle grease like attar of roses. Coumarin, a chemical derived from the tonka bean, the seed of a pod-bearing tree of Guiana; Bulgarian oil of roses, and aromatic compounds of benzene are some of the ele- ments used in these magic transformations. But substituting pleasant odors for disagreeable ones are not the only aims of this new branch of synthetic chemistry. Imitation leather has been given the fragrance of real Russian leather, and American chemists are now working on a process to impart an odor of Scotch and Irish peat smoke to domestic woolens. Turntable Device to Stop Rail Crossing Jolts TREET and railway cars may no longer bump over rail crossings if an invention of W. H. Whalen, a Los Angeles railroad man, proves successful in practical tests. In the usual intersec- tion, grooves are cut across each rail wide enough to allow the flanges of car wheels to go through. When a wheel strikes one of these openings, passengers are jolted. In Whalen’s four-track crossing, this difficulty is overcome by the use of four small turntables, one at each rail inter- section, and’ each containing a single groove. As a car approaches the cross- ing, they turn automatically, presenting the grooves in the right direction for the car to pass without encountering any cross grooves. A model, which Whalen re- cently exhibited, attracted the interest of California street car officials and a practical test was arranged. RP ein ei a | ore

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POPULAR SCIENCE MONTHLY Aucust, 1929 New Fire Boat Pumps 12,000 Gallons a Minute from four huge pumps, a new fire boat, said to be the largest in the world, recently gave a spectacular exhi- bition in the bay at Seattle, Wash. The craft, named the Alki, has just been added to the fire-fighting equipment of the city. Seattle recently won a trophy for the proficiency of its fire department in preventing and extinguishing blazes. Last. year it is said to have broken the world’s per capita fire loss record, setting the new low mark of eighty-two cents per person for such losses. The new fire boat can pump 12,000 gallons of water a minute when its ma- chinery is working at full speed, as in the photograph above. Fifty such boats could pump enough water to supply all New York City! The largest city in America uses an average of approximately 600.000 gallons every minute. Rudder in Bow Aids Liner to Make Sharp Turns HEN the helmsman turns the wheel of the Princess Norah, a new steamship recently launched at Van- couver, B. C., Canada, rudders at both the bow and the stern swing the boat in the desired direction. The vessel, de- signed for coastal service to the north of Vancouver, is unique in having a rudder at the nose. She was built for the Canadian Pacific Railway. A. glance at a map of British Columbia will reveal the importance of enabling a large vessel to squirm through narrow channels between jutting rocks of the in- numerable islands that stand along the coast. The rudder at the nose of the craft is expected to allow it to alter its course suddenly and to circle in narrow quarters. Pearls 25,000 Years Old Found in the Rocks EN of the oldest pearls on earth were found not long ago by geologists of the University of California in probing among rocks that were laid down 25,000 years ago. They came upon round fossil objects that proved to be real pearls, made by some prehistoric ancestor of the Grom four powerful geysers of water modern oyster. They range in size from three sixteenths to five sixteenths of an inch in diameter, and in spite of their great age, retain some of their luster. The find occurred near Redding, Calif. Tails Handicap Squirrel **Channel Swimmers’’ WIMMING the Mississippi River is as great a feat for a squirrel, sizes considered, as swimming the English Channel is for a man. Yet W. T. Cox, Superintendent of the Upper Mississippi Refuge, reports that these little rodents frequently plunge boldly into the water and head for the opposite bank. At first they swim with their bushy tails sticking straight up, as if to keep them dry. Later, as they weary in the struggle with the swift current, their tails sink lower and lower, until they are Unusual bow rudder of Princess Norah, de- signed to aid steering through winding channels. dragging in the water, making their progress more difficult. In every case, Cox reports, the squirrels seem to have a definite destination in view when they start their long swim. When allowed to crawl up an oar into a boat, they will ride as long as the boat travels in the direction they want to go. If its direction is altered, they jump out and resume swimming! Gray squirrels, fox squirrels, and red squirrels all have been seen crossing the Mississippi. Windows of ‘Health Glass” Make Hens Lay More LF pig glass has reached the chicken coop! Window panes admitting ultra-violet rays have been found to increase the fertility of eggs and to keep hens producing more of them. That these mysterious rays also speed up incubation was discovered by two ex- perimenters at the Mayo Foundation, Rochester, Minn., Dr. Charles Sheard and Dr. G. M. Higgins. When a quartz mercury arc, giving off ultra-violet rays, was added to the equipment of an ordi- nary incubator, twenty percent of the eggs were hatched from twenty-four to forty-eight hours sooner than other eggs of the same batch. In coops where quartz glass is not used, the addition of cod liver oil to the rations of laying hens is said to have the same effect as treatment with ultra-violet rays, increasing their egg-laying record. Gasoline Waste a Billion Dollars a Year O FEED the seven hundred and fifty million “horses” that power the auto- mobiles of the United States during 1929 will require seventeen billion gallons of gasoline and four hundred million gallons of oil, according to Dr. Gustav Egloff, an oil expert of Chicago, Ill. Present automobile motors, he says, are only twenty percent efficient, so that about eighty percent of the fuel is wasted. This annual loss he calculates to be more than a billion dollars a year. When engineers design a gasoline engine of greater effi- ciency, much of this waste will be saved, Dr. Egloff declares. a a a oa toe -* © 4 = wt wo 4 leet Oe 2déSes 4

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\e an enema D Aucust, 1929 Mountains of Waste Paper Salvaged by Machinery Dumped into a steaming vat, waste paper is beaten into a pulp and colored brown. T THE time of the Revolu- tion, there was not enough paper in this country to wad the guns of the Ameri- can soldiers and scarcely sufficient to carry the orders of the officers. In 1810, the consumption had reached a pound a year per person. Today, America consumes annually more than the combined weight of all the men, women, and children in the nation! What becomes of these millions of pounds of paper, used and thrown away? The manner in which much of it is reclaimed and made into brown wrapping paper or corru- gated cardboard is revealed by the pic- tures on this page, taken at a factory at Whippany, N. J. They show what hap- pens to the old papers that you save up and sell to the junkman. Huge storerooms receive the mountains of discarded newspapers and magazines when they arrive at the reclaiming plant. From these piles loads are carried into vat rooms within the factory. In these steaming caldrons, whirling arms beat the paper into pulp as it is fed in by the work- men. After passing through the maelstrom of a beating vat, the pulp goes through several refining processes and is colored to a brown hue. Then it travels to a great battery of steam-heated rollers, out of which streams the finished product. More than a hundred of these hollow rollers, filled with steam, dry and toughen the paper as they press it into an endless sheet. Emerging, it :s spun on rolls to be shipped. This is the process followed in making the wrapping paper. The manu- facture of the corrugated cardboard fol- lows much the same procedure up to the final steps, when the pulp is put through special machinery. Strange Dance of Smoke Seen under Microscope than a puff of smoke really looks YY like is revealed by a high-power microscope apparatus recently installed at the Museum of Peaceful Arts, in New York City. A visitor who blows cigarette smoke into the apparatus can see in- POPULAR SCIENCE MONTHLY New paper made from old. A roll of the finished product on hand truck, ready for shipment and commercial use. dividual particles of smoke dancing in a curious, erratic way beneath the lens, darting first in one direction and then another. Their strange motion, called a “Brownian movement,” is explained as due to their collisions with the invisible molecules of air that surround them. Drafty Dwellings Better for Our Health? HOUSE should be so uncomfortable that people will not stay in it too much, according to Dr. Leonard Hill, British pioneer advocate of sunlight and ultra-violet rays for. the promotion of health. If homes are too comfortable, he says, growing children may stay indoors and play when they ought to be out in the sunlight and open air. On the other hand, f peeve photographs on this page illustrate a striking instance of everyday waste turned into profit by in- genuity. Each issue of POPULAR SCIENCE MONTHLY contains scores of fascinat- ing articles and pictures bringing you the news of scientific discoveries and in- ventions for saving money, time, and labor. 61 Passing over a hundred rollers filled with steam, the paper is dried and toughened. if they grow up in drafty and cold dwellings, they exercise more and in the end live under more healthful conditions. He declares there is much to be said scientifically in favor of the light, flimsy houses of the Japanese —dwellings which favor outdoor life—and contends that our modern homes are warmer and more sub- stantial than they should be. Skulls Used as Drinking Bowls in Tibet W light on the mysterious land of Tibet and the strange customs of its inhabitants was shed re- cently by a collection of bone objects brought from that forbidding mid-Asiatie plateau by an expedition of the Field Museum of Natural History, Chicago, under the leadership of Dr. Berthold Laufer. Among the interesting articles in this collection are bowls made of human skulls, used for libations in honor of the Lama gods; trumpets made from human thigh bones; tambourines fashioned out of human skullcaps, and a bone apron consisting of forty-one large plaques exquisitely carved from bones and con- nected by double chains of round and square bone heads. Dr. Laufer, curator of anthropology of the Field Museum, explains that the skull bowls, some of which are elaborately decorated, lined with gilded copper and fitted with metal lids, are used by the Lama priests to pour liquor on the altars of their temples as tribute to the gods. The Tibetans also use these bowls in a peculiarly barbaric form of ancestor wor- ship, which prescribes that a dead man’s son preserve his father’s cranium and drink from it to his parent’s memory on his birthday anniversaries. The thigh-bone trumpets are blown to summon or disperse evil spirits. Either the bones of criminals or of persons hav- ing died violent deaths are used in their construction. The bone tambourines are shaken while reciting prayers. And the bone apron is used by magicians during secret ceremonies to pacify evil spirits and cast out demons.

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ia Siieelppesiindinttetdr sasieperatetemnermmens tet ee =z. te er ee re 8 ot a 62 ° High Speed Grinding Tool for the Shop — of 25,000 revolutions a minute is said to be obtained di- rectly, without the aid of gears or pulleys, from the small motor of a new grinder for shop use. This speed is made possible by using a rotary frequency changer, which raises an alternating current from sixty cycles to 420 cycles. The surface of a half-inch abrasive wheel, rotating at this high speed, travels more than half a mile every sixty seconds, enabling it to do fast cutting not pos- sible at 3,500 revolutions a minute, the speed of the usual shop grinding head. The frequency changer is separate from the grinding motor and one changing apparatus will supply current at higher frequency to several motors. Another innovation in the new tool is the method of oiling the ball bear- ings. While a continuous supply of oil is necessary, too much is objectionable. An automatic system sprays a fine mist of oil continuously over the bearings. After lubricating the bearings, the oil drains back into a reservoir to be S\ used over again. He Washes Dishes All Day to Test New Product F YOU dislike to wash dishes, you won't envy the job of Wilhelm Nauer, of Pittsburgh, Pa. He washes twenty trays, all day long, every day in the week. Nauer is a “scientific dishwasher” employed by the Westinghouse Electric and Manufacturing Co., to test a new kind of tray made with a paper base upon which a resin composition is baked. This composition is used also in making cer- tain types of propellers for airplanes. Every three and a half minutes, Nauer finishes scrubbing and wiping a tray. He will keep this up, month after month, until the trays wear out! The purpose of the unusual experiment is to determine the wearing quality of the new product. In manufacturing propellers, the resin composition is baked upon a canvas base. Propellers made in this way pulled the tri-motored Fokker monoplane, Southern Cross, on its flight from San Francisco to Australia, and carried Mait- land and Hegenberger, U. S. Army flyers, across the Pacific between America and Hawaii. Such propellers came into use during the war when black walnut, of which the screws were largely made then, became scarce, and a synthetic product was sought as a substitute. X Novel Pipe Wrench Grips Like a Human Hand WRENCH that grips a pipe like a human hand and is said to break the tightest joints without marring or chew- ing the surface of the metal is the latest aid to plumbers. Three curved chain links are hinged to the base of the wrench handle. They encircle the pipe, and a lip at the end of the last link hooks over a second lip on the base of the handle so that a slight pull on the handle tightens — a POPULAR SCIENCE MONTHLY All day Wilhelm Nauer, of Pittsburgh, washes and wipes trays to find how long they will wear. the grip of the links about the pipe. A movement of the handle in the opposite direction relaxes the hold of the links. Thus, a perfect ratchet action is pos- sible and the tool can be used in close quarters, it is reported. The fact that the wrench is without teeth is said by its makers to allow it to be used without damaging threads or marring brass pipes. Chain links, in place of jaws, circle the pipe and grip it tightly with pull of the handle. Aucust, 1929 The new grinding tool with small high-speed motor. The surface of half-inch abrasive wheel at right speeds half a mile every minute. Left: Grinding a plumber’s die with the new tool. Its high speed permits unusually rapid cutting. Smartest Children Are Strongest NUSUALLY _ smart children are taller and stronger and weigh more than less intelligent boys and girls, tests among New York public school pupils showed. The experiments were under- taken by a Columbia University professor to disprove the belief that the minds of geniuses are housed in puny bodies. The investigator compared a group of forty-five children, each of whom was the smartest among 200 schoolmates, with an equal number of average intelligence, duplicating each pair in sex, age, and race. Their development was watched for seven years and the difference in size, weight, and strength remained in favor of the gifted boys and girls. At the age of about ten years, the average height of the clever children was 52.9 inches as against 51.2 inches for the less gifted ones, and the average weight of the prodigies was 74 pounds as com- pared with 63.9 pounds for the others. Strength measurements showed that a good brain is usually accompanied by a strong right arm. The bright children had an average grip of 55.11 pounds, as compared with 51.58 for the duller pupils. Fountain of Racing Atoms May Explain Aurora FOUNTAIN of atoms, untold bil- lions of invisible particles rushing thousands of miles into the sky above the tropics and descending at the earth's magnetic poles, is pictured by Dr. H. B. Maris and Dr. E. O. Hulburt, of the United States Naval Research Labora- tory, Washington, D. C. In a recent report to the American Physical Society, they suggest that at great heights the atoms of rising air gases become elec- trified by ultra-violet rays from the sun. They are thus attracted, according to the theory, toward the magnetic poles, rush: ing at a speed of more than 5,000 miles an hour through the upper atmosphere. Such a hypothesis, the Navy physicists ‘declare, would explain the manner in which polar regions are provided with electrical energy to display the flashing brilliance of their auroras. s&s -— = me we me ele ome) be ee ee eee QO FeO et & 241 oS a —_ -

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> SY OS OS i rl . — wa er SS niretae POPULAR SCIENCE MONTHLY Left: The strange three-wheel truck. The load is carried in front and the driver in the rear. On the highway it arrears to run bacxwards. Below: Labor-saving machine for sorting various sizes of nuts, Odd Tricycle Truck Turns in Its Own Length TRICYCLE motor truck that swings around in a complete circle in its own length and appears to run backwards was recently put through successful trials in London, England. The load is carried in front, and the motor, tanks, steering gear, and driver’s cab are at the rear. Two ordinary-sized truck wheels with solid rub- ber tires bear the load at the front, while a single smaller rear wheel is pivoted at the center of the truck frame for steering. Because of the ease with which the un- usual motor conveyance can be whirled about or maneuvered in cramped quarters, the makers believe it will be widely adopt- ed for use in congested city districts. Comparatively small in size, it is espe- cially adapted for light hauling. By progressing in “‘crawfish fashion,” with the motor behind and the load be- fore, the vehicle, it is claimed, can be driven up to loading platforms or curbs with greater accuracy and less effort than is the case with trucks that have to be backed into such positions. Gas Pump Dial Safeguards Against Short Measure “MECHANICAL watchdog,” to pro- tect motorists from short measure at gasoline filling stations, is the inven- tion of A. R. Mason, of San Francisco, Calif. The device is attached to the gasoline pump and is said to keep an accurate record of the amount of fuel that passes through the mechanism and to show this record on a dial clearly visible to the car owner. At the end of the filling operation, the device automatically stamps a receipt giving the number of gallons of gasoline purchased. Sales up to thirty gallons are recorded by the invention. Oxygen Piped in Hospital N A manner similar to that in which illuminating gas is piped into a house, ‘oxygen now may be supplied to rooms in hospitals so that a constant supply is available at all times for administration In emergencies. A new invention which was devised to regulate the flow of this precious gas is said to make such an arrangement possible. screws, or bolts. Dropping between the threaded rods shown in the photo, they fall into bins. ” 7S y ‘) Ingenious Machine Sorts Screws, Nuts, or Bolts MACHINE that sorts various sizes of screws, nuts, or bolts that have been reclaimed from wrecked buildings, and places them in separate bins, has been invented by a Torrance, Calif., shop worker. It eliminates the tedious process of sorting by hand. A pair of revolving threaded rollers, driven by an electric motor, receive the odd-sized pieces from a hopper at one end. Under the hopper the rollers are close together, gradually spreading apart. Thus the smaller pieces fall through first. The larger ones ride along until the open- am New dial recording attachment for gasoline pumps and its inventor, A. R. Mason, of San Francisco. 63 ings between the rollers are large enough to admit them. Bins below catch the different sizes as they drop. Only one kind of material is handled at a time, the screws, nuts, and bolts being run through the machine separately. New Rustless Steel Cuts Glass Like a Diamond TEEL so hard it scratches glass like a diamond, does not rust, and retains its hardness even when red-hot, is now being produced in America by a nitrating process dis- covered some time ago. When an inexpensive form of steel is treated in a hard- ening box with circulating ammonia gas heated to a high temperature, it de- velops the thin, hard, rust- proof skin distinguishing the new metal. Recently nitrated steel pins and bushings in a mechanism for starting and stopping electric motors were subjected to a gruel- ling test by the Westing- house company. After the machine had performed its function some 22,000,000 times, inspection showed that all parts of it were worn out except the pins and bushings. They were as good as new. Many everyday uses for the new metal have been suggested. Safety razor blades of nitrated steel, it is pointed out, would never lose their edge, nor rust. Plow- shares could be left out in all weather without rusting, and bearings made of the metal would run until they became red-hot without losing their hardness. Two 1,000-Foot Steamers Planned in England MAGINE a steamship which, if stood on end and placed beside the Wool- worth Building, would top that sky- scraper by 208 feet! That is the size of two giant vessels planned by the Cunard Line, of England. Each of the enormous liners would be more than 1,000 feet long and have a displacement of at least 75,000 tons! The new ships would be the world’s biggest. The present cham- pionship is a matter of some con- troversy. The British White Star Line claims it for the Majestic, originally the Bismarck. This is contested by the American owners of the Leviathan, formerly the Vaterland. The Majestic measures 915 feet six inches in length; the Leviathan, 907 feet six inches. Dr. Ernest Foerster, consulting engi- neer of the Hamburg-American Line, who designed both steamers, said his original plans made both identical in size, but that, through a change in design, the Majestic was lengthened eight feet. This change is estimated to have added 700 tons of displacement, so that the Majestic now has a displace- ment of 64,800 tons, as against 64,100 for the Leviathan:

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Warship’s Oarsmen Train in the Fighting Top NE of the oddest training quarters for a rowing crew is the fighting mast of the U.S.S. California. Here the oarsmen, who represent that battleship in rowing contests, take their daily work- out. Their practice equipment is a rowing machine designed to duplicate, as closely as possible, an actual racing shell. Stripped to the waist, and bracing their feet in toe holds, the husky gobs “row” with “oars” consisting of grips attached to pulley weights, while the coxwain stands by, timing the strokes. The fighting mast is a tower of latticed steel designed to hold observers during a sea battle. It is made with weblike construction so that if a shell should plow through, it would still stand. If made solid, it would come down in ruins if a big shell struck it. Because the “cage” is completely open on all sides, the oarsmen practice under the same outdoor conditions of an actual race. Novel Draftsman’s Compass Designed for Precision NEW draftsman’s compass has been designed to eliminate the faults of the familiar two-legged instrument with which circles are usually drawn. The improved compass consists of a needle- pointed vertical post, from the center of which an arm runs horizontally. This arm, marked in fractions of inches on one side and centimeters on the other, carries a slide to which is attached a holder for the marking lead. Thus, by moving the slide along the measuring arm, the scriber can be adjusted accurately so as to obtain any desired radius. To fix the radius of a circle to be described with the ordinary compass, the two legs are adjusted near the hinge where they join. A slight error at this point is magnified at the tips of the —_ Also, the legs sometimes spread slightly while the circle is being traced and cause inaccuracies. The improved compass is said by the makers to eliminate both of these possibilities of error. It is claimed that after the compass has drawn a hundred consecutive circles, so fixed is the adjust- ment that it can go back over the first, tracing the original line exactly. POPULAR SCIENCE MONTHLY Rowing practice in the fighting mast of the U. S. S. Cali- fornia. Here the huskies of the crew develop skill and brawn on a rowing machine; the ‘“‘oars’’ are grips attached to pulley weights. Every time you sock it a good one, the “shadow ball’’ pic- tured below is likely to snap back and land you one on the nose. A rubber cord attaches it to head- band. The latest for boxing practice. Combines Shadow Boxing with Bag Punching PUNCHING bag that follows you around the room has been designed by H. O. Costello, a former boxer and athletic trainer, to combine the benefits of bag punching and shadow boxing. A ball, which serves as a punching bag, is attached by a rubber cord to a headband worn by the boxer. When it is struck, it flies out, the rubber band quickly snap- ping it back at the striker. In punching, dodging, and ducking, all the footwork and headwork of an actual ring contest are demanded from the user of the device, the inventor declares. Exercising with the ball is said to give a complete work-out of all the muscles and to be excellent training for boxing. The photo above shows the device in use. The new precision compass. It is adjusted by a slide which moves along the horizontal arm. Aucust, 1999 Secret of Film Pictures Found in Cattle Food! HE film in your camera records photographs because cattle don’t eat pure food. That, in effect, is the partial explanation of a long-standing mystery given by Dr. C. E. K. Mees, noted American photographic expert. The average snapshotter goes on taking pic- tures without bothering much about why specks of silver salt in a coat of gelatin on the flexible celluloid film turn black when light hits them. Though this is the phenomenon on which all photography is based, it has puzzled chemists for more than a generation. Now Dr. Mees finds that the specks of silver bromide used to impregnate the film are not alone responsible for its sensitive- ness to light, as was long supposed. Traces of a sulphur compound which he finds in the gelatin coating play an important part in making the silver crystals more sensi- tive. Gelatin used in films is made from the hides of cattle, and Dr. Mees says that the sulphur is there because the cattle eat plants that contain impurities. Although the exact mechanism by which the sulphur does its work is still not perfectly understood, it seems likely that if there were a “pure food law” for cattle, there might not be any more picture-taking. Curious Mineral Squirms and Sweats under Heat STRANGE mineral that writhes and perspires like a man when flame is applied to it, has been found in a large deposit near Libby, Mont. Called vermiculite, it has previously been discovered in small quantities in several parts of the United States. The Montana find was revealed by a prospector who was searching through an old tunnel in the Rainy Creek district. He noticed flakes of coarse, micalike ma- terial writhe and swell and give off water when touched by the flame of his candle. Although no commercial use has been found for vermiculite, its properties sug- gest that it may be valuable as insulating material; for, when expanded, it is very light, has a golden or silvery luster, and has low heat conductivity. Some types of the mineral burst into long threads when heated. The Libby deposits are accompanied by asbestos and feldspar. Army Tests Poison Gases on Hosts of Tadpoles SWARMING legion of more than 20,000 tadpoles became martyrs to science last year in the laboratories of the Chemical Warfare Service of the U. S. Army. The different poison gases with which the Service is experimenting are tested upon the wiggling “tads” to discover the exact amount required for a fatal dose. Experts of the laboratory say that the reaction of a tadpole to poison 1s . similar to that of human beings, and for this reason they form a cheap and effective means of testing the war poisons. Four shipments a year, each containing from five to ten thousan tadpoles, are supplied by Army men en- gaged in swamp dredging in Tennessee.

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ds at ial ry ic- vy ill ly or wee SPO lee SO _— oP RU Oar es S&S CV Aucustr, 1929 Comets Hauled from Space by Our Solar System? NEW theory of the origin of comets was advanced recently by Dr. N. T. Bobrovnikoff, of the Lick Observatory, California. He suggests that a million years ago, when primitive man was already on the earth, our solar system swept through a meteor-sprinkled part of space, carrying off comets in the same way that a speeding motor car will catch insects in a swarm and pull them along with it. This belief is strengthened, he declares, by mathematical theories of the move- ment of heavenly bodies, which indicate that our solar system is using up its celestial fireworks and that comets are getting scarcer. Somewhere, billions of miles in the direction of the con- stellation Orion, lies the cloud of scattered meteoric matter where the | “comet catching” took place, ac- cording to Dr. Bobrovnikoff. A striking feature of comets is the small amount of solid matter they contain in proportion to the size of their streaming, gaseous tails. The famous comet of 1882 was estimated to have a tail a hundred million miles long. Yet, the famous British astronomer, Sir John Herschel, de- clared all the solid matter in it could be packed into a traveling bag! Ancient Roman House Had Furnace and Bath HAT the ancient Romans used hot-air furnaces in their homes is shown by the arrangement of the foundations of a Roman villa, prob- ably built toward the end of the third century, which was recently unearthed in Hampshire, England. The basement has an outer wall of flint set in cement, from which a flue leads to a furnace chamber. A layer of soot on the floor and walls of this chamber indicates that the house had an under- ground heating plant. This is further proved by channelings under the floors and flues in the walls through which the heat was circulated. ; Below the remains of a tessellated floor raised about three feet above the furnace chamber is a small drain, which suggests that the villa also had a _ bathroom. Discovery of a coin bearing the likeness and name of Emperor Constantine the Great, who reigned in the beginning of the fourth century, served to establish the approximate age of the house. The archeological treasure was discovered accidentally by a farmer who came upon it while planting an apple tree. Handy Typewriter Lamp Shields from Glare LIGHTING attachment that illu- A minates the keyboard of a type- writer, but shields the glare from the eyes of the typist, is part of the equipment of a new portable machine. The electric lamp, on an adjustable lever at one side of the machine, is equipped with a curved reflector which directs the light down on the paper and the keys. Current is supplied to the lamp through a cord which can be plugged into any POPULAR SCIENCE MONTHLY convenient outlet. The light can be adjusted to prevent reflected glare from the paper. The new attach- ment is said to eliminate much of the eyestrain from night typing. A New Way to Get That Exercise N INGENIOUS exer- cising apparatus, in- vented by a French physical culture instructor, can be set up in the home and is said to strengthen all mus- cles of the body. It consists of a steel rod, with a weight at one end and a The new home exerciser—a pivoted bar with a weight at one end and handle and stirrup at the other. handle and a stirrup at the other, pivoted on an upright metal post. In using the apparatus, one foot is ex- tended back of the body and placed in the stirrup, while the hand on the same side grasps the handle. The weighted rod is pulled down with both hand and foot until the muscles are tired. The handle is then shifted to the opposite side of the rod and the muscles of the other side of the body are exercised in similar manner. The apparatus can be adjusted to suit the height and strength of the user. Shaded-lamp at right of machine throws light on the work while shielding the typist’s eyes Mechanical Archer Tests Arrows for Defects WOODEN bowman that shoots every arrow in a quiver with the same speed and with equal accuracy, tests the “ammunition” used by the Archery Club of Seattle, Wash., to detect arrows that are defective. The mechani- cal archer is the invention of Rev. J. J. Pflueger, a Seattle pastor and a member of the club, seen at right in the photo. The wooden platform of the device holds the bow at the front, while the bow- string is pulled back by a sliding block attached by a cable to a pedal at the rear of the apparatus. String and arrowhead are gripped by two notched wooden wheels in the sliding block. These turn as the block is pulled back, engaging notches in the platform, in a sort of ratchet arrangement. After the pedal has been pushed down, drawing back the bow, a trigger is sprung to release the wheels, allowing them to turn and letting go the bowstring to drive the arrow. The force of the shot is determined by the dis- tance the pedal is depressed. The ele- vation of the platform, determining the angle at which the arrows are shot, is regulated by a sliding arm at the front of the apparatus. Besides detecting defective arrows, the machine enables the club members to trim the feathers of all arrows so they shoot the same under the same con- ditions. When shafts have passed the test of the wooden bowman, and then fail to hit the bull’s-eye in subsequent tournaments, the club members know the fault is with the archer and not the arrows. Tunnel Diggers Find Gold A TUNNEL that paid for itself in gold was completed in the Philippine Islands not long ago. While building an aqueduct to bring water to Manila, diggers encountered a 9,000-foot vein of ore valued at $20,000,000, it is said. Within a thirty-mile radius of Manila are several areas of gold bearing ground.

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DOM ae nannEy iaeiendeies oe ee Rear of one of the new stock quota- tion boards, showing intricate mechanism which relays electrical impulses from operator’s keyboard : to moving numbered cylinder dials. cad Electric “Board Boy” Posts Stocks N AN effort to keep up with 10,000,000- share days in Wall Street, electric stock quotation boards have been invented to replace the old hand method of posting, in brokers’ offices, the prices at which stocks are selling. The usual method is for ““board boys” to post the quotations by hand, as is done in displaying the score at athletic contests. It is slow, lagging far behind the ticker tape, which itself frequently falls behind the active market. A French war ace originated the idea upon which is based one of two new electric stock quotation boards. The ticker tape passes before two operators in the sending room. They sit at machines-that resemble typewriters and, by pressing down keys that correspond to the figures which are ea Keyboard of posting machine, and one of the dial units (above) of the board shown at left. printed under each stock on the tape, cause the numbers to appear on the wall board under abbreviations of the stock name. The keys make contacts which cause electrical impulses to shift small rotating cylinders inserted in thequota- tion board beneath each listed stock. The Microscope Casts Its Wonders on a Sereen NSTEAD of looking into the eyepiece of a microscope and then making a free-hand sketch of what is seen, with attendant inaccuracies,laboratory workers Within the curtained “dark room”’ an enlarged image of object under microscope appears on screen for tracing. now can trace the outline of the enlarged object directly from an image thrown upon a sheet of paper. This is made possible in a recent German invention by special lenses and mirrors. Light - from a microscope lamp is pro- ") jected through the glass slide that holds the specimen and up through the microscope to what ordinarily would be the eyepiece. In the new instrument, however, the eyepiece is replaced by glass prisms that reflect the enlarged image to a flat mirror. This, in turn, throws it upon a sheet of paper within a dark-curtained inclosure, in much the same man- ner as a moving picture image is thrown upon a screen in a theater. All the laboratory worker has to do is to trace around the image and he has an accurate enlarged drawing of the object being examined. Hl Wiis a i 4 A second type of board installed in a stock broker’s office. Beneath each listed stock is a moving paper strip on which are printed the quotations. The operator, at extreme right, posts the quotations as recorded on ticker tape. Avucust, 1929 py aS Salt cylinders are numbered from one through nine to zero, so that the touch of the “typewriter” key causes the correct number to appear. All stocks whose abbreviations begin with letters in the first half of the alphabet are handled by one operator; all those in the second half, by another. This arrange- ment increases the speed of the posting, which is said to be limited now only by the speed of the ticker. From a central sending office, boards all over the country can be operated. In case a broker wants reports on only a few stocks in which his customers are inter- ested, he can cut out all the rest and receive only these by “plugging in” on a device resembling a telephone switchboard. In the second type of electric quotation board, the operator sits beside the ticker in the broker’s office and posts the quo- tations electrically for the one board, instead of having it operated from a dis- tant sending room. The method of post- ing the figures also is different. Instead of rotating numbered cylinders, it employs strips of paper on which are printed the changing quotations. Each time a new transaction is recorded, the strip under each stock méves downward from a roll concealed behind the board, and displays in type the latest quotation. The figures are stamped on the strips by printing mechanisms at the rear of the board, con- trolled electrically from the operator’s “typewriter.” Joy and Sorrow Upset the Digestion, Says Expert HEN you have just been informed that you are going to get the raise in salary you asked for, don’t celebrate by eating a big meal. Likewise, avoid the dinner table right after receiving sad or unpleasant news or while very tired or absent-minded. Those, in substance, are the “don’ts” issued recently by Dr. Walter C. Alvarez, of the Mayo Clinic, Rochester, Minn., who declared that joy, fear, anger, and all other emotions upset the digestion. They cause the blood to flow to and from the lining membranes of the stomach, which is not fit to perform its digestive function when it contains too much or too little of the vital fluid.

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Aucust, 1929 Strop This Safety Razor Like a Straight One HE latest innovation in safety razors, » parte met by Rollin C. Warner, of Albany, New York, is one whose blade can be sharpened, like a barber's straight razor, on an ordinary strop. It is simple in construction and in use has the ap- pearance of the ordinary hoe-type safety razor, yet no special apparatus is re- quired for stropping. The photographs below show the razor being used and the manner of sharpening. On the side of the blade opposite the cutting edge is a metal tube. When the blade is to be sharpened, the guard and handle are removed and the tapering end The new safety razor in use, and with handle ad- justed for stropping like a barber’s straight razor. of the handle is pushed into one end of the tube, bringing the handle parallel to the cutting edge of the blade. In this position the blade can be stropped or honed like any straight razor. How Improved Roads Cut Your Motoring Bill HEN the roads in your neighbor- hood are improved, the cost of operating your automobile is lessened by one to two cents a mile. After studying the operating expenses of more than 1,600 automobiles and trucks, the Iowa State College Engineering Experiment Station, at Ames, recently compiled _ Statistics to show the part good roads play in reducing motoring costs. The figures reveal that when a poor road is changed into a high-class high- way, those who use it regularly have 2.06 cents a mile clipped from the cost of driving their cars. A reduction of 1.07 cents a mile results when a bad road is made into a road of fair quality, and -99 cents a mile is saved by improving a fair road to a high type highway. The same investigation showed that the 1,600 machines ran an average of 11,000 miles a year each, and that their operat- ing cost varied from four to nine cents a mile, depending on the type of machine. POPULAR SCIENCE MONTHLY Rare Books on the Screen for All to Read ARE volumes at the Berlin State: Library, Germany, are being repro- duced for general use in a novel manner. Each page of the book is photographed with a special camera of extraordinarily small size. Later, enlarged slides, made from the camera plates, are thrown upon a screen for patrons to read. The slides are sent out to various libraries in Ger- many, so that the contents of the rare books, of which there may exist but a single copy, are made available to many readers while the precious volume itself remains unhandled and preserved. In making the photographic plates, a rack which holds the book open at the page to be photographed is placed on a table top facing a small camera mounted on a pygmy tripod, as shown in the photograph above. The slide made from the photograph is numbered to corres- pond with the page number of the book. Thus a reader can “‘turn” to the page he wants by selecting the slide with the Ten-Pound Radio Transmitter for Airplanes geese MIDGET radio transmitter that weighs only slightly more than a portable typewriter, and occupies less space, has been devised for use of flyers by experts of the United States Coast Guard. Complete in itself, the baby set weighs less than ten pounds. It is to be put through rigid tests by W. W. Reynolds, Chief Radio Elec- trician of the Coast Guard, seen examining the little apparatus in the photograph. If it stands up under the tests it will become part of the equipment of coast guard seaplanes so that these “eyes” of the coast patrol can report from the air to their bases during flights, as well as receive instructions by means of receiving sets. In an emergency an S.0.S. and the plane’s position can be transmitted to headquarters. The editor will be glad, wherever possible, to supply the names and addresses of manufacturers of de- vices mentioned on these pages. number and placing it in the projection machine, which flashes it upon the screen as long as he wishes to read it or make notes from its contents. Curious Facts Revealed by Propeller Tests N RECENT tests of airplane pro- pellers, Westinghouse engineers found that with a 400-horsepower propeller blowing directly at a large hole in a near-by wall, air cannot get out! Like panic-stricken people in a burning build- ing, the rebounding and eddying air jams the exit. An eight-foot pipe through the wall, projecting four feet on each side, avoids this confusion, and lets out a vigorous blast. The roar of this propeller test neces- sitated a noise-proof building. Due to the churning air, the room became nearly two degrees hotter every minute, and at 120 degrees F. ventilation was necessary. a W. W. Reynolds, chief radio expert of U. S. Coast Guard, with ten-pound transmitter for airplanes.

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POPULAR SCIENCE MONTHLY eit = oe

Future Trip to the Stars Portrayed in Movies HE adventures of a celestial Colum- bus who sets sail into space with two companions in a weird electrical Santa Maria form the theme of a motion pic- ture film recently produced in Germany. The time is supposed to be a. p. 3929, two thousand years hence. The hero of the film story is the inventor of a mar- velous spherical airship driven by whirl- ing rings, with which he defies gravity. This fanciful machine, pictured above, contains an air pressure tank to protect the occupants as the machine soars away from the earth’s atmosphere on its trip of exploration among the heavenly bodies. Beyond the range of earth’s gravity the passengers find themselves walking on the ceiling of the compartment like flies. Other fantastic adventures befall them but each is said to be based upon known laws of Nature and discoveries of astronomy, giving the story a plausibility that adds to its interest. Germless Arctic Islands the Healthiest Spot? 1594, more than 100 years after Columbus discovered America, the Dutch navigator Barend Barendsz, still seeking a short cut to the East Indies through the North Polar sea, was caught in the ice off the islands of Nova Zembla in the Arctic Ocean north of Russia. Barendsz and his crew were marooned on the islands for three years and suffered untold hardships from lack of food. Little did these sturdy sailors dream that the scene of their sufferings was the most healthful spot known in the world. Yet a Russian scientist claims recently to have discovered that Nova Zembla is entirely free of disease-breeding germs. The investigator, who spent a winter on the islands, tested air, water, dust, and earth without finding one germ. He placed sterile dishes containing agar-agar jelly, a substance considered especially conducive to bacterial growth, outdoors for many hours and then heated them in an incubator. The microbe hunt proved fruitless! A similar experiment conducted for fifteen minutes in any city in the United States would have resulted in the

Adventurers in the fantastic gravity-defying airship are pictured in the new movie as walking on the ceiling of the cabin. Above: A view of the strange ship, driven by whirling rings, leaving earth. formation of populous germ colonies. Next came an astonishing experiment. Fresh meat was put in an open jar and placed outside, where it was left for eight months. At the end of that period, there wasn’t a trace of putrefaction! Nova Zembla is an archipelago con- sisting mainly of two islands. On the southern island live about 100 persons. - These people; if all the Russian scientist says is true, should be the healthiest and longest-lived specimens of humanity. But the investigator’s report made no mention of the inhabitants. It did, how- ever, recommend the establishment of sanatoriums on the island. Sonic Depth Finder May Locate Sunken Gold OLD, jewels, and other treasure worth millions that lie in sunken vessels on the ocean floor may be located and salvaged with the aid of the sonic depth finder, according to Rear Admiral H. P. Douglas, hydrographic officer of the British Navy. While the approximate locations of wrecked treasure ships are known, the great difficulty in attempted salvage has always been to find the exact spot. This, the English officer believes, may be done with the sonic depth finder, a device which, by transmitting sound waves from a vessel and recording the time required for them to be reflected back from the bottom of the ocean, determines the exact distance between the surface and any object they strike far below.

Aucust, 1929 Five-Million-Dollar War on Fruit Fly Pest FIVE-MILLION-DOLLAR battle is being waged against the Mediter- ranean fruit fly in Florida. This pest, recently discovered for the first time in the United States, has caused severe re- strictions to be placed upon the move- ment of fruit out of Florida, where infested areas are confined, and where the U. §, Bureau of Entomology has begun a death battle against it. The fly, itself, is a harmless insect about the size of a house fly. Its habits are cleanly. It lives upon plant juices and “honey dew” such as some insects ex- crete. But the activity of a large family of grub “children” it produces more than outweighs the good be- havior of their parents. Several flies often lay their eggs in the same hole, bored in the skin of a fruit or vegetable, so that as many as a hun- * a dred of the hungry grubs . \ hatch out, eating rav- \ enously and growing rap- idly. After ruining the fruit or vegetable, they rest as pupae, and then emerge full-grown flies, ready to produce an- other family of the de- structive grubs. The life cycle of a complete gen- eration of the Mediter- ranean fruit fly often covers less than a month, so they increase rapidly. First known as a pest in Spain in 1842, the insect spread to all the fruit-raising coun- tries of the Mediterranean, thus gaining its name, before extending its activities to Australia, New Zealand, Brazil, and the Hawaiian Islands. It is most success- fully attacked in its adult stage. New Thermometer Easy to Read beers MERCURY ther- mometer designed to be read as easily as a watch has been produced through the use of a new kind of bright red glass. The color of this opaque material was found to offer greatest contrast to the silvery gray of mer- cury. Against the red background, the top of the mercury column can be seen at a glance. Although the strip of the glass is wider than the mercury column, shields restrict the amount that is visible, so the width of the gray and the red strips are the same. The rising mercury blots out the red. The thermometer in the illustration is designed for use on the boiler of a house heating plant. The new feature also is being applied to hospital and room thermometers.

Ab TR

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Aveust, 1929 Mechanical Money Changer ‘‘Spots’’ Counterfeits HE United States Treasury once paid a high salary to a man who, while counting gold pieces, was able instantly to detect by touch every defective or fraudulent coin. In a candy store in New York City the other day, a robot demonstrated similar infallibility in handling silver quarters. Its business is to turn out five nickels for a quarter and to watch for counterfeit money and worthless slugs. When a coin is given to the “‘ mechan- ical man,” before it returns the five smaller coins, it automatically weighs the quarter, analyzes its metallic content, and determines if its size is up to stand- ard. As a test, three types of bad coins were offered. One was made of gilded brass, another was slightly undersize, and a third was slightly underweight. Each time, the machine returned the quarters with the request “Please - use good coins only” uttered by means of a phonograph record which is set in operation when the delicate mechanism determines that a bad coin has been in- serted in the slot. Warship’s Long-Range Guns Fire Tons of Steel IGHT and a half tons of steel, in the form of screaming shells, leave the big guns on the U. S. S. California every time they all are fired together. An unusual photograph of part of the ves- sel’s armament in action was obtained recently during battle practice in the Pacific. The long-range guns were snapped from the bridge as gunners trained them upon a distant target at the rear of the battleship. To the left of the guns, with a sailor standing upon it, can be noted one of the launching catapults for the swift scouting airplanes with which all battleships of the Pacific Fleet were recently equipped. Big guns of the U. S. S. California in action, photographed from above. Plane-launching catapult is seen at the left. POPULAR SCIENCE MONTHLY Army Tanks “Lock Horns” in ITH clawing endless treads and panting motors, two Army tanks recently fought out a butting contest on the level plain of Miller Field, Staten Island, N. Y. They met in head-on Camera and Tiny Furnace Tell How Fuel Burns TOY-SIZED furnace only three feet long and six inches thick, with a mica window in its side, is helping to show the best design for boilers burning powdered fuel. Camera records made through its window reveal just what happens to a burning particle shot through it, accord- ing to H. K. Griffin and David F. Smith of the Pittsburgh Experiment Station, U. S. Bureau of Mines, and J. R. Adams, research fellow of the Carnegie Institute of Technology. The complete track of each burning particle is recorded on the photographic film, which revolves on a drum in the camera. From this chart an observer can tell how long the particle took to burn, and also, through thermometer and gas measurements, how much oxygen it used up and how much heat it yielded. Among the fuels tested ‘so far are coal, coke, and charcoal. Analysis of what be- comes of a single speck of fuel in the miniature furnace gives a perfect small-scale reproduction of combustion in a big one, the experimenters say. Scientists above Par Physically OES an interest in science benefit us physically? A reply in the affirmative is sug- gested by tests covering five years made upon members of the National Academy of Sciences by Dr. Ales Hrdlicka, anthropologist of the U. S. National Museum, Washing- ton, D. C. He took measure- ments of one hundred of the eminent scientists who belong to the Academy and compared them to the measurements of the population at large. The results showed, he re- ports, that the scientists possess an above-the-average physique and a large head, contradicting the old conception of a scientist as a long-haired individual who neglected his body. Butting Battle collision during Army maneuvers, and neither would give way. Steel clashed against steel, treads bit into the earth, motors roared, while the two jugger- nauts pushed and bumped. At last one reared into the air, astride the nose of the other, and was pushed backward onto the steel skids at its rear so that its treads no longer dug into the ground, and the battle was over. The victorious tank then backed away, lower- ing its steel antagonist to the ground with a final snort of its powerful motor. Dyed Trees May Give Us Colored Lumber CHEMES to dye the sap of a tree so that colored wood will result usually have been classed with trying to cross milkweeds and eggplants to produce egg- nogs, or feeding hens ham so they will lay ham omelets. Now, experiments in Maine indicate that the plan may be more feasible than jokers have supposed. The process followed in experiments recently reported by a chemical organiza- tion are as follows: About four feet from the ground, a number of holes were bored in the trunk. Others are bored in three or four of the main roots. All were con- nected by rubber piping with a dye res- ervoir, placed twelve feet from the ground among the branches to form a ‘gravity feed” of the dye to the roots and the trunk. Throughout the early spring, a con- stant supply of dye is carried by the sap to all parts of the tree. The process at present is described as expensive, for the average tree requires about six pounds of dye, and the construction of the reser- voirs requires considerable labor. But cheaper methods may be devised so that varicolored wood for furniture some day may be produced in this manner on a large scale. UNUSUAL events, useful in- ventions,. and important discoveries are reported on these pages each month in hundreds of fascinating arti- cles and pictures. POPULAR SCIENCE MONTHLY not only helps you keep abreast of the times, but offers many practi- cable ideas that you can apply to everyday problems,

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— of Bargains! Veteran Service Man Warns of Gyp Receivers That Lurk Behind Attractive As told to NEWTON BURKE STARTED in the radio game through a newspaper “ad” that read: “Radio service man wanted. Fine oppor- tunity for advancement. Must have own car.” I'd played around with radio till I really knew quite a lot about it. I had what passed for a car, so next morning I applied for the job and got it. My new boss was smooth in manner and a nobby dresser. “Young man,” he told me, “your job is to keep the cus- tomers satisfied. Don’t argue with ’em. Don’t tell ’em anything. Just fix the sets so they'll work, but spend as little time on them as possible. I’m selling sets with a free service guarantee, so the more sets you can fix in a day the less the service is going to cost me.” “T’'ll do my best, Mr. Slade,”’ I replied. He took me into the back room. It was as bare as a hermit’s cave. “This is where you hang out,” he said. He seemed to take it for granted that I had all the necessary tools. “Now get busy,” he ordered, handing me a bunch of service call slips. I sneaked home. chucked a pair of headphones, a couple of screw drivers, a soldering out- fit, and some other junk into an old bag and set out to make my calls. I followed instructions. I didn’t say a word that wasn’t That crook I was working for had kidded the old fel- low into trading in a feally good battery set for @ fancy box full of junk. es POPULAR SCIENCE MONTHLY Radio Cabinets necessary. But what a lot [found out! The first call took me to a dis- agreeable old woman who handed me an awful call-down. “Well it’s about time they sent you around!” she rasped. “Here I’ve paid my good money for a new electric radio set with free service, and do I get the service? I do not! That set hasn’t been working for three days.” You can imagine my surprise when I dug into that fancy-looking cabinet and found a shoddy, old-style battery set run by an antique combination A and B eliminator of the liquid type made by some fly-by-night concern. The _ set hadn’t been any good even when it was new, and the eliminator had been in storage so long the connections were all corroded. One was eaten through and when I fixed it the set worked. She was stung, no doubt about that. HE next few calls were much the same and I became more disgusted with each one. Then I struck one that made me boiling mad. A white-haired old man, an invalid, apparently with only a little money to spend on luxuries, was sitting there patiently waiting for some- one to fix his set so he could listen in again. That crook I was working for had kidded the old fellow into trading in a really good battery set for a fancy box full of junk under the impression that he a oN “Your job,”’ said my new boss, Fix the sets, but spend just as little time on them as possible.’’ “is to keep the customers satisfied. was getting a modern electric receiver! I quit the job. Since then, I’ve batted around a lot as a radio service man and I'm convinced that you can’t get some- thing for nothing. In fact you’re much more likely to get nothing for something! A radio bargain set is like any other bargain. It isn’t worth a cent more than you pay for it. At best, it’s a last year’s set with last year’s faults. The main thing in buying a set is to know exactly what you are getting. Don’t let a fancy cabinet fool you. . It’s easy to hide some out-of-date model and a three- dollar loudspeaker behind shiny wood- work. I’m not saying there are no real radio bargains. Changing styles often throw good outfits on the market at clearance prices; but only the man who knows radio can know a real bargain from a fake, or can analyze the disadvantages of an obso- lete set and decide whether the price is low enough to offset them. HE mere fact that a receiver actually is a full electric set doesn’t prove that it’s modern. Plenty of early types of electric sets that now are “orphans,” with no manufacturer standing back of them, are reposing on shelves waiting for easy- mark buyers. If you don’t know anything about radio, before you buy a set familiarize yourself with the appearance of the lat- est receivers as advertised by the manu- facturers. Note particularly the model or type number, the number and kind of tubes used, arrangement of controls on the panel, and so on. The same reasoning applies to loudspeakers. Remember that no matter how little you know about the actual functioning of a radio set, nobody can sting you with an obsolete outfit if you know exactly what you want to buy and then insist on getting it. no NR ees

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AvuGusT, 1929 Two New Tubes—W Remarkable A. C. Screen Grid Amplifier Offers Undreamed-of Distance, and an Improved Power Tube Adds Volume with Excellent Tone Quality By ALFRED P. LANE OU will hear a great deal this fall and winter about two remarkable new radio vacuum tubes. One of these, the new UY-224, is a heater type screen grid amplifier designed to operate directly on alternating current, the heater voltage being two and a half, the same as required by the UY-227 tube. This tube seems destined to revolution- ize our conception of what is possible in radio-frequency amplification. Two stages of radio amplification, using this tube, will give as much amplification as can be obtained from four stages using the ordi- nary 201A tube or its A. C. equivalents, the 227 or 226 tubes. However, it must be remembered that while two stages of screen grid radio- . frequency amplification may be made equivalent to four stages of ordinary amplification, as far as sensitiveness to distant signals is concerned, the screen grid circuit would not equal the circuit using the older tubes for selectivity, be- cause selectivity is determined to a large extent by the number of tuned stages. To obtain the same selectivity with the two-stage screen grid circuit it would be necessary to include extra tuned stages even if no tubes were connected to them. The other new arrival is the UX-245 power amplifier tube. This tube fits in between the 171A tube, which has been on the market for some time, and the very powerful UX-250 tube introduced last season. Working at recommended maximum voltages, the 245 tube will give as much volume without distortion as the UX-210 tube. And still more important, it ac- complishes these results with a maximum plate voltage of 250, only seventy volts more than re- quired for best results with the 171A tube and 200 volts less than the recommended maximum volt- age for the 210 tube. _ means that by using the new 245 tube it is now possible to obtain a large amount of vol- ume without distortion and yet keep the B-voltages to a point where very expensive filter con- densers and rectifiers are not re- quired in the B-eliminator circuit. POPULAR SCIENCE MONTHLY 71 hat They Do RE ‘a Testing internal capacity of new UY-224 screen grid tube, and effectiveness of ex- ternal shielding methods, in radio laboratory, Popular Science Institute of Standards. For instance, the voltage requirement of a 210 tube used singly or in push-pull arrangement necessitates the use of the 281 type rectifier tube. A B-eliminator circuit to furnish the necessary current for a 250 tube used singly or in push-pull must be of the full wave type using two 281 tubes. The necessary voltage and current requirements of the new UX-245 tube are, however, so much lower that it is possible to operate a single tube at maximum voltage requirements from the much less expensive 280 full wave rectifier tube. If the B requirements of the rest of the radio circuit are not too severe, it is - possible to operate two 245 tubes in a push-pull circuit, with the necessary cur- rent obtainable from a tube of the 280 type. HE UY-224 A. C. screen grid tube is a logical development from the UX-222 battery-type screen grid tube. Similarly, the UX-245 power tube is a logical devel- opment from the UX-171A tube. Figure 1 shows these four tubes side by side so that you can compare them. At the left is the UX-222 battery-type screen grid tube. Next to it is the new UY-224 A. C. screen grid tube. Then comes the 171A tube, and at the right is the new UX-245 Fig. 1. New tubes compared with old. Left to right: UX- 222 battery-type screen grid tube, new UY-224 A.C. screen grid tube, 171A power tube, and the new UX-245 power tube. power tube. The new A. C. screen grid tube is not merely an A. C. type of the battery operated screen grid tube, but is definitely a more powerful radio-fre- quency amplifier. In fact, it is at least twice as good as the battery-type tube. This improvement in operation was made possible by the more copious flow of elec- trons obtainable from the A. C. heated cathode, together with a rearrangement and change in spacing of the elements in the tube. principle the screen grid amplifier tube of either the battery or A. C. type is essentially like an ordinary 201 tube except for the spacing in the elements and the addition of an extra element in the tube, the screen grid. To understand the exact functions of the screen grid it is necessary to re- fresh your memory on the ordinary opera- tion of a standard type tube. You know, of course, that the action of any tube de- pends upon the flow of electrons sent out from the heated filament or cathode. In the screen grid tube the addition of the screen grid and the spacing of the ele- ments or electrodes makes the plate cir- cuit of the tube of exceptionally high resistance without materially reducing the effect of the grid voltage on the plate current. Therefore, increas- ing the number of turns in the plate coil will greatly increase the voltage amplification of the circuit. Because of the lower re- sistance of the plate circuit of the ordinary 226 and 227 or 201A tubes, increasing the number of turns in the plate coil would not prove equally effective, and in practice would not be possible be- cause of the difficulty with re- generation and oscillation effects. Placing a screen grid in the tube in such a way that it will shield the plate from the grid therefore accomplishes two very important results. First, it reduces the electrical capacity between the ed

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72 plate and grid and this greatly reduces the tendency toward oscillation. Con- sequently, all ordinary neutralizing meth- ods may be dispensed with, provided, of course, that the screen grid tube is prop- erly shielded. This necessity for guarding against oscillation is what cuts down the ordinary tube’s efficiency as a radio-frequency amplifier, and if the screen grid accom- plishes nothing more than to eliminate the capacity between the elements it will be a worth while improvement. Actu- ally, however, the screen grid accomplishes still more in that it greatly increases the tube’s power to amplify signals in the manner al- ready mentioned. N THE ordinary radio vacuum tube the flow of electrons is attracted to- ward the plate because the latter is at a positive volt- age. ‘In the screen grid tube both the plate and the screen grid are at positive voltages, the screen grid of the new UY-224 being nor- mally biased at seventy-five-volt positive, with 180 volts applied to the plate. The peculiar construction of both the battery type and the A. C. type screen grid tube, in which the control grid is brought out to a metal cap on the top of the tubes, is necessary to keep the capac- ity between the control grid and the plate at as low a figure as possible. You will note from Figure 3 that the screen grid is interposed between the cylindrical plate and the control grid in such a way that the capacity between the two is re- duced to almost nothing. In the ordinary vacuum tube where all the leads are brought out to the prongs on the base, at least half of the internal capacity of the tube is due to the capacity between the leads themselves. In the screen grid type the capacity between the leads is almost eliminated by bringing the control grid lead out to the cap on the top of the tube, and the screen grid eliminates the capac- ity between the elements. CONSIDERATION of these factors will show you how important it is to prevent any capacity between the leads outside of the tubes. The entire benefit conferred by the peculiar screen grid con- struction and the metal cap lead for the control grid would be completely lost if, for instance, the grid and plate leads from the tubes were so placed that there was POPULAR SCIENCE MONTHLY screen grid removed, exposing the sheet metal plate. The third view shows the plate removed, exposing the inner screen grid, while the view at the right shows the inner screen grid removed leaving only the control grid and the A. C. heated cathode element. The connection to the plate, the cathode, the screen grid, and the heater filament terminals are brought out to the five prongs on the base of the tube, which is designed to fit into the standard UY socket. The control grid, as mentioned above, is brought out to the small metal cap, cemented to the top of the tube. In Figure 4 is shown a theoretical wir- ing diagram of an ordinary 227-type tube arranged as a radio-frequency amplifier, and in dotted lines are shown the addi- tions that make the circuit cor- rect for the screen grid type tube. ECAUSE of the charac- teristics of the screen grid type tube, it cannot be used in a regular circuit unless changes are made in the radio- frequency transformer. The number of turns in the plate coil must be increased. If the screen grid tube is used in a circuit with the correct number of turns for the 201A or 227 tube, the amplification ob- tainable actually may be less than that obtained from the 227 or 201A tube. Thus if you attempt to revise the cir- cuit in a radio receiver you must, in addition to arranging for the new connec- tions to the tube, greatly increase the number of turns in the coil marked L in the diagram of Figure 4, below at left. To obtain the maximum results from the new screen grid Fig. 3. shows the arrangement of elements in the new A. C. Figure 2 shows the com- plicated construction of the elements in the new UY-224 A. C. type screen grid amplifier tube. It is this complicated and delicate construction which accounts for the higher price of the new tube. At the left is capacity between them. ° : The illustration of -B shown the complete as- 2%) sembly minus the glass tube. Next to it is shown the elements with the outer section of the amplifier. Fig. 4. Wiring diagram showing ¢s- sential parts of a radio-frequency Dotted lines changes in using screen grid tube. tube it is necessary to l pay particular atten- tion to shielding. If you use only one stage of radio-frequency am- plification you can get away with practically no shielding. With two or more stages ex- ing must be resorted to. e.4 Theoretically, perfect shielding would inter- pose a metallic shield over the lead wires go- ing to the control grid, indicate Fig. 2. New UY-224 A. C. screen grid amplifier tube dissected to show complicated construction. This diagram amplifier tube. tremely careful shield- . Aucust, 1929 and also to the plate terminal of the socket, in such a way that there would be no external capacity between them. Furthermore, the shielding must prevent capacity effect between corresponding leads in different stages. In a forthcoming issue of Porutag Science Montuty, probably next month, will appear a constructional article that will show you how to take full advantage of the amplification possibilities of the new screen grid tube by means of practically com- plete shielding. HE current require- ments for the UY-224 screen grid amplifier tube are as follows: heater volt- age 2.5, either A. C. or D.C.; heater current, 1.75 am- peres; plate voltage, 180 volts; screen voltage, maxi- mum 75 volts; grid bias voltage, minus 1.5 volts. The new UX-245 power tube fits the standard UX socket, but it cannot be used in a set designed for the 171A tube. This is be- cause the UX-245 is de- signed to operate at two and a half volts on the heater filament and if it is placed in a circuit designed for the UX- 171A tube, where five volts are applied to the filament, the tube will be burned out at once. The filament current of the tube is one and a half amperes. The plate voltage is 250 maximum, and the grid bias voltage should be minus fifty volts. It is possible, therefore, to use the UX-245 tube in any receiver designed for the UX-171A provided the fila- ment current is reduced: in voltage to two and a half, but owing to the high fila- ment current it is not a good tube to use in a battery type set unless a separate A. C. filament heating transformer is used to sup- ply the filament current for the UX-245. It will operate with satisfactory results on 180 volts on the plate, in which case the grid bias voltage should be minus thirty-three. The plate current of the UX-245 is thirty-five mils as compared with a maximum of twenty mils for the UX-171A. F YOU already own a radio receiver us- ing the UX-250 power tube in the last stage of audio amplification, the UX-245 tube is of no particular interest to you as you are already using a tube having a greater power handling capacity than the new tube. The same reasoning applies if you have a receiver using a UX-210 tube. However, if you are considering the pur- chase of a new receiver, choose a set designed to handle the UX-245 in pref- erence to the UX-171A. Of course, if the receiver you are considering is equipped with two UX-171A tubes in a push-pull circuit that is another story, for two UX-171A tubes operating in push-pull ~ will deliver more undistorted power than a single UX-245. z Wenn et or . ’

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ee Avucust, 1929 POPULAR SCIENCE MONTHLY 73 Timely Kinks for the Radio Fan Plugging in the Short-Wave Set How to Make a Simple Adapter Connection from an Old Tube Base—Current on the Farm—B-Eliminator Facts NE of the simplest ways to con- nect a short-wave receiver to your regular broadcast set, so as to make use of the audio am- plification in the latter, is to construct a special adapter plug which can be placed in the detector tube socket of the broad- cast receiver in place of the detector tube. This special plug can be made easily from the base of a burned-out tube. Wrap the old tube in several thicknesses of cloth, place it on the workbench, and break the glass with a hammer. The - function of the cloth, of course, is to guard against flying glass. . Remove from the base all of the glass fragments, as well as the cement that held the glass tube in place. To remove the fine wires at- tached to the tube prongs, grasp each wire in turn with a pair of pliers and touch a hot soldering iron to the soldered connection at the tip of the prong. This will soften the solder and you can pull out the wire. Replace these wires with the new leads which are to be connected to the short-wave adapter unit, and solder them to the prongs. Since the prongs on the base are not marked, the simplest way to determine which is the grid prong, and so on, is to place the base over a socket and note the markings on the socket which indicate the connections. How to Use 32-Volt D. C. F YOU are located on a farm where the only source of electric current is that from the battery-operated farm lighting plant, there are two ways in which you can use the thirty-two-volt current to operate the filament circuit of a battery receiver. The simp'est and most satisfactory method is to tap into the battery itself, using three cells. However, if the farm lighting outfit is at some distance from the house this is not practical, because very large wire would be required to obtain the full six volts for your re- ceiver. Under such conditions the best method is to use the full thirty-two-volt potential with a variable resistance to reduce the flow of current. If your receiver is of the standard five- tube type, it requires a current of one and a quarter amperes. A rheostat to handle this current on a thirty-two-volt circuit should have a resistance of not less than twenty-four ohms, with a current-carrying capacity of not less than one and a quarter amperes. The simplest method of control is to connect the rheostat in series with the drop wire that you plug into the light socket. Turn the Using pliers and a soldering iron to remove the wires from the prongs of burned-out tube base. rheostats in the set full on and connect a high-grade voltmeter permanently across the A-battery wires inside the radio set. Always place the plug in the electric light socket with the rheostat turned so that the full resistance is in the circuit. Then gradually turn the rheostat until the voltmeter reads exactly five volts. You will notice that practically all of the resistance must: be in the circuit when the battery is fully charged and that the rheostat must be turned to maintain the full five volts as the battery runs down. Special rheostats suitable for this service A B C’s of Radio FTEN it is difficult to lo- cate a mistake in wiring a receiver after the work is completed. You may check the actual wiring against that shown in the blueprint dia- gram a half dozen times with- out finding the error. And yet the fact that the receiver re- fuses to work is positive proof that something is wrong either with the wiring or with some piece of apparatus. If you encounter trouble of this kind, fold up the blue- print and put it away. Then, on a large sheet of paper, make a rough but accurate wiring diagram, working directly from the receiver. Then, get out the original blueprint again and check it against the drawing you have made. Very frequeatly, by means of this method, the mistake is immediately apparent. are sold by most radio supply houses. The same system, of course, can be used on a 110-volt farm lighting circuit. A suitable rheostat for such service should have a total resistance of not less than eighty ohms and a current carrying capacity of one and a quarter amperes. B-Eliminator Condensers N THE standard filter circuit of a B-eliminator three condensers are used. One is connected directly between the positive wire and the negative wire before the first choke coil, the second between the two choke coils, and the third across the line beyond the second choke coil. All of these condensers have a definite effect on the filtering action of the circuit, but they are not exactly alike in their action on the hum. The first condenser has little action on the hum but great effect on the final voltage produced. The larger the first condenser, the greater the final voltage and also the greater the strain on the rectifier tube. The size of the middle condenser is of most im- portance in determining the amount of hum produced. The larger the condenser, the less hum you get. The size of the third condenser has some effect on the amount of hum but has a greater effect on the tone quality of the signals.. A relatively small condenser here will not seriously increase the hum but will result in poor tone quality. The third conden- ser acts as a storehouse for the current drawn by the plate circuit of the power tube and must be large enough to supply the instantaneous demand for relatively large amounts of current required to reproduce the low notes. Solder or Binding Posts? O FAR as operating results are con- cerned, it makes no difference whether you wire your receiver with solder con- nections or use binding posts, provided you make a solid joint. Radio fans who have never tried a soldering iron seem to think it takes longer to make solder connections. If the instruments are fitted with soldering lugs this is not the case. Usually it takes less time to solder a wire to a lug than it does to form a neat loop in the wire, remove a binding post nut, fit the loop over the screw, and replace and tighten the nut. Furthermore, it is always more difficult to cut a piece of wire to the proper length if you have to allow for loops at each end than it is if you simply have to make connections to a soldering lug.

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74 POPULAR SCIENCE MONTHLY Aucust, 1929 Design selected by the Kerseys for the home they plan to build. Their problem is to choose the best materials. Courtesy The Home Guild of America, Architects. Lining the Rooms of Your House A Wide Variety of Good Wall Materials Are Available to the Home Builder— An Expert Helps You to Choose * “TOW can we talk about what we are going to do indoors?” asked Mrs. Kersey. With her husband she was paying a third visit to the architect’s office, getting his expert advice on plans for their suburban home. “Of course, it has been. interesting to find out how the outside walls and roof should be made, and I’ve enjoyed it;, but I’m crazy to get to work on the plans for inside. I want a white Colonial dining room, and the living room is to be oak with beams across the ceiling. The kitchen is to be tan and blue, and—” ‘Here now, don’t go so fast,” broke in the architect. “‘ You can’t decorate your walls before you build ’em, you know, and that’s what I want to see you about.” “Well, what is there to the walls?” inquired Mrs. Kersey. “‘They’re plaster, aren't they? And that’s just—just—put on, isn’t it?” “Yes, but you can’t put it on air. So far, your walls are only a frame of studs sixteen inches apart, and they have to be covered with something to put the plaster on. The question is, what is that some- thing to be? You see, plaster has no strength, and when it’s in a thin sheet on a wall, it can’t even stand up by itself. It isn’t sticky, soit won’t hold on wood. The commonest way to put it on is to nail wood lath across the studs a little dis- tance apart, and to spread a thick mixture of plaster on them with enough force to shove some of it through. The plaster that goes through will bulge and droop down over the back, and when it hardens it acts as a hook that binds the plaster to the lath. The same idea holds true for metal lath, but that is full of little holes, and the plaster gets more of a grip. And metal lath won’t burn. Another way is to line the walls with sheets of material porous enough for the plaster to cling to; little threads of plaster work into the a home of your own? In this article, one of an entertain- ing series, an expert gives valua- ble advice on how to select the best materials to assure beauty, comfort, and durability. If you have some special problem, Pop- ular Science Institute will be glad to help you solve it. Just write a letter to the Building Service, Popular Science Institute, 250 Fourth Avenue, New York City. = you, too, planning to build By ROGER B. WHITMAN pores, and when they dry the plaster sur- face is there to stay. **But what are your ideas about decora- tion? It may be that in some rooms you won't use any plaster at all. Are you planning to finish with paint or with paper?” ** Wall papér in the bedrooms and in the dining room,”’ said Mrs. Kersey. “‘In the living room I want scenic paper in panels with moldings around them, and the rest of the walls painted. The library should be paneled in oak, I think, and of course the bathrooms should be tiled.” “‘That’s something to start on. You'll want plaster under the wall paper, so we can settle on how you want it put on.” “Does it make any difference?” “Not in appearance. But there'll be a difference in cost, and in permanence. Wood lath will be the cheapest, but it'll move with the settlement of the house, and the plaster will crack. Metal lath costs more, but has much greater strength. It comes in big sheets that are put on with the edges overlapping, and being steel, it won't distort enough to crack the plaster unless the settlement is much worse than it should be. It should be used wherever there are expensive decorations as a sort of insurance against damage—in the living room, dining room, and the en- trance hall. When people can’t afford to use it over the whole room the next best thing is to put it in the corners. That’s where cracking usually begins, and strips of metal lath bent to fit will do a lot to hold things together. “But with any kind of lath you'll have to wait a couple of weeks or maybe a month for the plaster to dry, before you can decorate, and that’s something to think about. There’s the chief advantage in using plaster board; you can decorate as soon as it’s up.” “Plaster board?” inquired Mr. Kersey. “What's that?” “TTS plaster cast in sheets at the fac- tory and covered with tough paper for strength. It’s wide enough to stretch over three or four studs, and goes from floor to ceiling. Joints between the sheets are filled with special cement, and covered with paper-thin strips of perforated metal. The joint is so smooth that when it’s papered or painted you can’t see it. Plas- ter board hasn’t the strength of lath and plaster, but it can be stiffened by giving it acoat of plaster. And there’s a new ma- terial that’s even better. It’s like plaster, but is much harder and stronger, so that one coat will make plaster board or wall board as stiff as you could want it.” “Now you're springing another new one,” broke in Mr. Kersey. “‘What do you mean—wall board?”

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Lucust, 1929 “You might call it artificial a wood,” responded the archi- tect. “It’s made of wood fiber or some other vegetable fiber ground up and pressed into boards one eighth or ‘one fourth inch thick and four feet wide. The fibers run every which way, so there’s no grain. Some kinds are compressed so hard they’re al- most like wood; you can nail them to the studs and have a finished wall ready for paint- ing. They're not so good for papering, because there's no way to make a smooth joint between sheets that won’t crack and show through; but you can nail moldings over the joints that will divide the wall or the ceiling into panels, and with painting you'll get a mighty pretty effect that would be hard to beat. ** Other kinds of wall board, not compressed so hard, are porous enough for plaster to bind to them. They're put up with the same kind of joints as plaster board; strips of per- forated metal or insect wire bedded in cement. Those porous wall boards are thicker than plaster board. They are sound deadeners, and good heat insula- tors, too.” “‘Did I understand you to say that one kind of wall is fireproof?” asked Mrs. Kersey. “That’s metal lath and plaster; but I didn’t say fireproof—I said fire re- sistant. That is, it is better able to keep the wood behind it from catching than the others.” “That's what I want, then. Fire is the one thing I’m afraid of. Will you put metal lath behind the paneling in the library, too?” “ATO, THE wood is nailed directly to the studs. But if you want to make that room fire-safe, there’s a kind of paneling made of cement. It is so exact an imitation of carved wood that the first time I saw it I had to dig it with my knife before I could believe it was anything else. It has the grain and the color, and you can get it in practically any pattern you want.” POPULAR SCIENCE MONTHLY Applying porous wall board as a base for plaster. Thicker than plaster board, this material is a sound deadener as well as a good heat insulator. “Put us down for that, then, and the downstairs rooms are all settled.” “Oh no, they’re not. How about the kitchen? Have you thought of having that tiled?” No, I haven’t,” responded Mrs. Kersey. “Would you put tiles all over?” “Yes, if you’re willing to stand the ex- pense, and to my mind it’s worth while. Glazed clay tile won’t absorb grease and smoke, it is easily cleaned, and will keep the kitchen fresh and bright.” “That sounds fine, and I'd like it—if we An unusually attractive example of the modern tiled bathroom. The tiles are cemented to a backing of metal lath and cement plaster and fitted one by one. 75 can afford it. Is there any- thing else we might use?” ““Oh yes. Any finish that’s hard and smooth will do; something that grease won’t cling to—enamel, forinstance. You could use enameled plaster, but it’s better to have something harder. You can make the walls of sheets of cement and asbestos; that is hard as a rock. The sheets are nailed to the studs or over plaster board or wall board, and they come already enam- eled and divided to look like tiles. You could use that in the bathroom, too; it’s water- proof.” “ATO, I’VE set my heart on a tiled bathroom,” said Mrs. Kersey. “‘By the way, how are tiles put on? Are they nailed?” “Heavens, no! You can’t nail a piece of china, and that’s practically what tiles are. There’s a backing of metal lath and cement plaster, and the tiles are cemented to it. They are put on one by one. Have you decided on the color?” “T've been dreaming about it for months. The walls are to be dark green at the bottom, shading through light green to white at the top and the ceiling. It’s to look hke the bottom of the ocean, you see.” “With the bathtub hollowed out of a chunk of coral, I suppose?” the architect laughed. “‘But seriously, that should look good, especially if you use tiles that are not evenly colored. You can get them with wavy surfaces and in shaded tones, to avoid monotony. Any large wall surface that’s the same all over is uninteresting compared with one that has high lights and shadows, and that changes with the lightings. Take your living room, for instance, where you say you want panels of scenic paper with painted surfaces be- tween. Don’t have those surfaces dead flat and of even colors. Either make them rough, or stipple them in two or three colors to give texture and inter- est. But don’t go too far the other way. Don’t make the walls so rough or of such staring colors that they kill every- thing else. “Did you (Continued on page 133) Left: Wire cloth bedded in plaster makes a neat, noncrack- ing joint between sheets of wall board or plaster board. This photo shows how it’s done. Applying the first coat of plaster on metal lath, Some of the plaster,. forced through many small holes, binds the rest firmly to the lath,

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POPULAR SCIENCE MONTHLY Aucust, 1929

ewest Household Devices

Open the bottom of this novel two-door laundry hamper, and the clothes tumble out. There’s no need to fish for clothes wadded in the corner. Garments to be laundered go in the top door.

< es ae ne £ Cooking foods in their own steam is made easy by a new waterless cooker that prepares a whole meal at a time. The lower picture shows the heavy bottom of three layers—two of aluminum, with as- bestos between—to prevent scorching. O fe . ee This fiye-watt night lamp for nursery or sick room goes on when the main light above it is switched off. The drop cord which suspends the lamp screws into any socket.

Here’s a sanitary new way of disposing of kitchen refuse. Paper bags are held open by a metal frame. When a bag is full it is closed by a draw string and thrown away. —_, Beauty and utility combine in_ this prize-winning kitchen sink de- signed by a Uni- versity of Califor- nia art student. Note spacious table areas, con- venient drawers, and cupboards. A new type of base for pots is said to convert any covered saucepan into a “waterless cooker.’’ Placed over a gas flame, it forms an air pocket beneath the pan and prevents scorch- ing. ‘The heat is comparable to that of a double boiler.

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Avcust, 1929 POPULAR SCIENCE MONTHLY | 77 OES some part of housekeeping cause your wife worry or drudgery? Maybe she needs one of these inventions. Twin labor savers for the kitchen are a new can opener and knife or scis- sors grinder, inter- changeable in a single wall bracket. The can opener will remove the lids of round, square, or oval _ containers. This hinged bracket makes easy work of hariging clothes from a window. Bracket, pul- ley, and line swing into the room. No need to lean out. The same device with grinding wheel attachment in place. Scissors are sharpened on a special small wheel at the side, while knife blades are given an edge in groove at center. A convenient kit for han- dling and filling baby’s bot- tles. It holds seven, steri- lizes them all at once, and supports them for filling. Toasted sandwiches can be made in short order with this up-to-date aluminum electric grill. It turns out one a minute, and adjusts itself to any size, from paper-thin to thick sliced sandwiches, Made of waterproof fiber, this remarkable kitchen apron cannot become damp or soggy, according to the maker. It alsoresists grease. Turn the crank, and you have potato chips. Simply place a potato into the convenient holder of this Built into a new electric ironing machine is a convenient tray to receive the ironed articles. It facilitates greatly the handling of sheets and other machine and a revolving large pieces, and it gives the ironing machine the utility of a table as well. cutter does the rest. It also The entire equipment rolls on casters, so that it can be moved easily to slices carrots and onions. the most convenient location, where it is plugged into a wall socket.

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POPULAR SCIENCE MONTHLY AuGust, 1929 F Hour Motorized Workshop How to Use It Expertly in Making a Colonial Footstool or Other Small Pieces of Furniture HEN I was a boy of fourteen it was a treat for me to visit my chum’s home workshop and try my hand at turning some simple “whatnot” on a homemade foot-power lathe. Today many splendid small woodworking ma- chines are available. All one has to do is to turn on the electric switch to experience the expert’s joy of creating beautiful and useful things from wood. It is my purpose in this and following articles to show the amateur how to make beautiful, useful, and substantial pieces of furniture almost entirely with these motorized home workshops, and do it more easily and accurately than by hand. The first project, a footstool of Colonial design, allows a variety of machine operations to be learned. Obviously, any similar small piece of furniture will in- volve the same methods. Mexican mahogany is an excellent material to use for the visible parts, al- How to hold the rails (sidepieces) when cut- ting them to exact length on the circular saw. though other woods such as birch or maple may be substituted and stained to imitate mahogany, if desired. Step No. 1—Getting Out the Stock for the Rails. On the circular saw cut the four rails (two side and two end pieces) to the approximate sizes to make it easier to handle them on the planer. Pine or whitewood will serve for them if they are to be covered with upholstery. Plane one surface smooth and true and mark it with an X on all pieces to indicate the working face. Hold this face against the planer fence and joint (plane) one edge smooth and true. This edge on each piece should be marked with an X to identify it as the working edge. On the circular saw hold the working edge against the fence and rip all pieces to the width of 2% in. (% in. being allowed for planing). In like manner cut the four Author of Art and Education in Wood-Turning By WILLIAM W. KLENKE Colonial footstool made by Mr. Klenke to demon- strate how small woodworking machines are used. MACHINERY is remaking all our home workshops. More than anything else, the introduction of compact, ef- ficient, and reasonably priced woodworking machines has helped to popularize the hobby of making things with tools. Why? Because machines lend new zest to the work, they take away the drudgery, and they make it possible for the beginner as well as the trained craftsman to turn out satis- factory projects. In a series of articles, of which this is the first, Mr. | Klenke will demonstrate in detail how to operate both combination and_ individual machines. Through the cour- tesy of various manufacturers, he will illustrate the use of many machines that have been approved by the Popular Science Institute. pieces (if necessary) to the thickness of 14% in. (4% in. extra for planing). Now cut one end of each piece square. Adjust the guard to get each pair of pieces exactly the same length, and cut the other end of each. Plane the remaining surfaces and edges smooth and true on the planer. Step No. 2—Legs. Draw and cut out an accurate cardboard pattern. Use it to mark the wood. To avoid splitting, bore %%-in. holes for the handles or cross spindles before sawing the curves. On the jig saw cut the design out carefully, keeping just outside the lines. Be sure to make “‘safety”’ cuts in the waste stock where necessary to avoid having to back out the saw at acute corner curves and perhaps cause the blade to break. Step No. 3—S pindles. The stock should be 1% by 1% in.; this allows \% in. for truing up on the lathe. Locate the center of each end by drawing diagonal lines. Bore small holes to receive the points of the lathe centers. Rough the corners off with a gouge and then turn to the largest diameter. Next cut down a short distance to give the exact length from shoulder to shoulder—8 in. Turn the spindle to the design and sandpaper it in the lathe. Turn the dowels at the ends to exactly % in. in diameter and 1} in. long, and as you cut the work free, round up the ends with a small skew chisel. Step No. 4—Sandpapering. On the disk sander true up and smooth all flat sur- faces and convex curves. For concave CF : {- ri pee Cutting one of the footstool legs on the jig saw. Note the rod and adjustable foot which holds down the stock on the table. One face of each piece is planed; then this face is held against the fence or guide of the planer and one edge is jointed (made true) as shown at the left. The posi- tion of the hands is important. A swinging guard presses against the wood and covers the cutter.

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Avcust, 1929 POPULAR SCIENCE MONTHLY ons ih 2D a) a6 4+ Se oe | 7 TL q- of E ‘A-COLONIAL*F OG® -BY= “WILLLAM*W-KLEN KE: s SEDE-VIEWS Mr. Klenke’s original pencil sketch of the footstool, made as a preliminary to illustrating the va- rious steps in machining the parts. curves use a drum sander, if available; otherwise turn a cylinder to 3 in. in diameter and fasten a sheet of No. 14% sandpaper to it. Step No. 5—Joints. Locate accurately all centers for the dowel holes—two in each end of each of the four rails and corresponding holes in the legs. By means of the lathe and a chuck, bore all the holes. If you use a short auger dowel bit, which is advisable, first file off the threads on the point (leave the point itself) to prevent the bit from pulling too fast. Step No. 6—Assembling. Make a trial fitting of all parts between clamps but without glue. Mark the joints of mating members No. 1 and No. 1, No. 2 and No. 2, and so on. Two separate gluing operations are necessary. First glue the long rails and legs together. Place a scrap of wood under the clamp to avoid bruising the legs. Put plenty of glue into the holes and on the dowel pins; then GLUE BLOCKS FOR >‘ BRACE 7 ) ! ” ° uN ---% X12 DOWEL as f > =o oq . ¢ F b-— , Yd TOP VIEW 3sDOWEL 1 1" SQUARE. “— RES [ INE OF UPHOLSTERY = ay @.\ a I Mkt = Seo © © es | Rte ‘a0 1! Se ae | Pee FRONT VIEW Dimensioned views which show the shape of legs and spindles and the exact location of the dowcls. For details, see the drawings in the lower left-hand corner. Step No. 7—Cleaning Up. Remove all excess glue with a sharp chisel, cutting, wherever possible, across the grain. Sandpaper thoroughly all parts with No. \%, 0, and 00 paper, rubbing with the grain. Round the corners slightly. Step No. .8—Finishing. There are many ways of finishing mahogany. One of my favorite methods is as follows: Buy a high-grade mahogany water stain powder and dissolve according to direc- tions, or obtain a prepared wood stain or Cleaning up the convex curves of the legs on a drum sander. If this type of sander is not available, a sanding cylinder can be turned from wood, the edges of the sandpaper being held in a groove with a small strip of wood; the roll is used in the lathe. The spindles or handles in the lathe. Calipers are used to make measure- ments. Note the stock left for dowels at each end, | clamp the work together lightly. Use only a liquid glue of the best quality or a tested brand of flake hide glue. Sight across the legs for any twist.’ Allow at least five hours for the glue to dry. Next assemble the project completely, being sure that all four legs rest on a true surface, that the frame is square, and that the tops of all rails are in line. It isa good idea to have some fine sawdust on hand when gluing to sprinkle over the glue that oozes out; this will absorb it sufficiently to allow it to be peeled off like gum immediately afterwards with a chisel. When the glue has set, glue the corner blocks in place dye of first-class quality. Use liberally and let it dry. Brush on very thin white shellac and sandpaper when dry with No. 00 paper. Apply two coats of paste wood filler, following the directions on the can. Allow at least two full days for the filler to harden. Apply three thin coats of white shellac, rubbing each coat when dry with No. 00 sandpaper, and the last coat with crude oil (or light machine oil) and fine pumice stone powder. If you have a spraying outfit, spray clear lacquer on instead of shellac. The selection of a covering and the method of applying the upholstery is a matter of individual! choice.

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POPULAR SCIENCE MONTHLY AucGust, 1929 ! New O *, — (RATS . \ ee ¥; : zi a ‘ eee eee — : var Yi XY Bit 7 You can duplicate some of the finest effects of professional decorators by panel- ing your living room walls with specially prepared and easily applied moldings. rnaments for Your Home Ways to Use the Ready-Made Carvings and Moldings Now Available for Walls, Woodwork, and Furniture By BERTON ELLIOT MATEUR decorators now have at their disposal a wide variety of ornamental carvings, moldings, and relief decorations. These have been placed on sale in many of the larger paint stores and painter's supply houses throughout the country, as well as in some of the more up-to-date smaller paint stores. Applied carvings have been used in fur- niture factories for years, and relief decorations have been employed to a considerable extent in public buildings, clubs, and fine residences. Ready-made decorative materials of this kind, how- ever, have never before been generally available to the home decorator. This form of decoration, which is new to most home owners, provides thickness in addition to length and breadth and therefore gives a depth and richness of appearance that cannot be obtained through flat surface decoration. It pro- duces high lights and shadows with their ever interesting and changing effects. There are two distinct types of relief ornaments on the market. One consists of relatively small ornamental carvings, in- tended principally for use on furniture, but used to some extent for adding deco- rative touches where needed on door Mr. Elliot blends the colors on a wall molding with a cloth to match a so-called “‘Tiffany’’ finished wall. The wreath below—a perfect imitation of delicate wood carving—is for use on furniture. panels, wood trim, and other architec- tural surfaces. These are generally made from some wood composition. The other type consists of larger de- signs for wall and ceiling decoration. Some of these are cast from various com- positions, but a newer form, made of pressed fiber or paper, is proving popular and has stimulated the present vogue for - relief decoration because of its light weight, ease of application, and reason- able price. Wood composition carvings and mold- ings come in a variety of designs covering the principal requirements of furniture decoration, including panel centers, key plates, knob plates, post aprons, and corner pieces. Wreaths, baskets, vases, urns, floral groups, garlands, and rosettes are among the patterns most generally offered. These are handled in much the same way as transfer and stencil decora- tions, except, of course, that their use is precluded on table tops and similar places. The color treatment may be obtained in various ways. Where used on painted furniture the carvings may be finished in the trim color of the piece being deco- rated—colored free-hand with an artist’s brush, wiped off in polychrome effects, dusted with bronze powder, or antiqued with brown pigment. Applied carvings are still better adapted foruseonstained (Continued on page 124)

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Aucust, 1929 This POPULAR SCIENCE MONTHLY Model Flies Straight Up How to Construct a Small Rubber-Driven Helicopter of New and Improved Design By VINCENT JOHNSTONE a Vi ‘ie ck ° OU may have to wait many years to see large airplanes that are able to take off and land from the same spot without any run what- soever, but with relatively little difficulty you can build a spectacular flying model of a helicopter, as this type of ship is called. Man-carrying helicopters, of course. have actually risen from the ground and flown in the same manner, but the main difficulty lies in steering them accurately in any desired horizontal direction. If you build and experiment with the sur- prising little model shown in Figs. 1, 2, and 3, you may discover some principle which, if adapted to a large helicopter, would make it more practical. Before describing the construction of this recent model, I should like to remind you of the historic helicopter given to the Wright brothers by their father in 1878. This was made as shown in Fig. 4 and is known as the Penaud type. After you have built the new half- minute helicopter, you can construct the earlier Penaud model, if you wish, by adding a little sail at the bottom of the model and eliminating the set of propel- lers fastened to the body, leaving only the one propeller mounted on the shaft. In- deed, you will have a better helicopter model than the Wright brothers had, as your Penaud model will be of the latest materials—balsa wood, ambroid type cement, selected rubber strands, and music wire. The half-minute helicopter has made rapid progress in the way of records. At the time this article was written the official record stood at thirty-seven sec- onds. Unofficially, a flight of forty-one seconds has been made. As the propeller mounted on the shaft rotates in one direction, a torque is Fig. 1. Helicopter models, although novel and rarely seen, are easy to make and per- form weil in the air. produced in the opposite direction. On the Penaud model this torque was taken up mainly by the flat sail surface; but in our half-minute helicopter the problem is met by allowing the body to rotate with a set of left-hand propeller blades, which are attached to it. These opposed blades produce lft as well as counteract the torque, and the arrangement gives greater efficiency. Helicopters are rather unstable. You will note this to be true with your model, especially if you build a two-blade pro- peller for the shaft (Fig. 2), for at the instant when the two sets of blades are parallel to each other the helicopter loses its stability; but, of course, it recovers aS soon as the sets of blades separate. If you build a three- or a four- bladed propeller for mounting on the shaft, you will over- come most of the wobbling. zs HE helicopter model's weight is most important. Be sure that you make your propeller blades extremely light; in fact, almost paper thin. Light weight is one of the main keys to the success of the machine. The materials needed are 4 or 6 pes. balsa %% in. thick by 1% by 5% in. (triangular) for pro- — blanks; 2 pes. lg by % by 8% in. 8 PIECES _ Mahe av, ERIECES . Aax 4 BLADES ~ o@ RIGHT-HAND .. PROP! balsa veneer; 8 pes. % by % by % in. balsa veneer; 2 pcs. 44 by % in. square balsa veneer; 1 pc. No. 8 plated music wire for making S-hooks, bottom hook, and propeller shaft; and 3 small washers. The body is made of two thin balsa veneer pieces, as illustrated, with cross- pieces of the same material at 1%4-in. intervals. You should see that the parts are well cemented together. The two ends are joined with pieces of balsa 4% in. thick, which are slightly rounded off. A small brass washer should be ce- mented to the very center of the top piece on the outside to form the bearing. The bottom piece is provided with a hook cemented at the center. Inciden- tally, tweezers are handy for inserting the S-hook in place if the motor is wound with an egg-beater winder. The propeller blades all can be made alike if you wish. They should be cut from triangular blocks of balsa % by 1}4 by 5% in. and carved in the usual man- ner, except that two (or three or four, as the case may be) are right-handed and two left-handed. The blades of the propeller operated by the shaft should rise at an angle of about 15° as shown. Use a %-in. cube for the hub of a four- bladed propeller and a 5-in. triangular block for one with three blades. The shaft should be slipped in place loosely and the propeller balanced. The blades which are fastened to the body also are attached at an angle of 15° to a horizontal line—one blade to one side of the body and (Continued on page 117) CEMENTED JOINT Gua Te cement) : 3 BLADES» Fig. 2. A helicopter model of the type which holds the world’s record. The upper propeller can have two, three, or four blades, as preferred.

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82 POPULAR SCIENCE MONTHLY ARCHIMEDES lather of Applied Science Sumner Buiossom, Editor Raymonp J. Brown, Managing Editor Artruur WakE.inc, Home Workshop Editor Aurrep P. Lang, Technical Editor Epocar C. WHEELER, Associate Editor IsraEL Doskow, Art Editor Published Monthly by Popular Science Publishing Company, Inc., 250 Fourth Avenue, New York City. Single Copies Twenty- five Cents. In the United States andIts Possessions and in Canada, $2.50 the Year. In All Other Countries, $3.00 the Year. What Is Science? OME people still associate the word science with musty tomes full of involved mathematical formulas, read only by be-spectacled college professors. Actually, however, any book that deals with facts or principles is just as truly a work of science as is a textbook on chemistry or a vol- ume devoted to the Einstein theory. The word science, as the dictionary defines it, means knowledge of principles or facts. According to that all-embracing definition, anything outside the realm of pure imagination must necessarily be science. Science is, therefore, the fountainhead of all human progress —of all human art—even of all human thought. For progress involves the use of knowledge and facts, art has to do with the skillful handling of materials which are the products of knowl- edge, and even the wildest flight of the imagination must, at least, have had a starting point in fact! In this issue we are starting a new department which we may truthfully say is almost pure science. It is filled with new facts —curious facts—and above all with interesting facts. Turn to the PopuLar Scrence Scrap Book on page 57. Making Stamps Stick EADERS of Popru.ar Science Monruty, as a whole, dis- play a keen interest in mechanical whys and wherefores. They want to know what makes the wheels go round. And when the wheels stop, they want to know why. This analytical frame of mind is shown in a letter from one reader who found out why. Having noted, he writes, recent adverse comments in the newspapers regarding the poor stick- ing qualities of postage stamps, and having had some trouble of the sort himself, he studied the problem and came to the con- clusion that the trouble is with the user and not with the gum on the stamps. They fail to stick, he explains, because they are not properly applied. The average person licks the stamp and thereby removes the gum, whereas if the envelope is moistened and the dry stamp pressed on it, the stamp will stick so tightly that it cannot be removed without tearing. Whether a stamp sticks or not may seem to be a small mat- ter, but who can tell when a loosened stamp may be the direct cause of a severe financial loss or, perhaps, result in upsetting the most carefully laid plans? And the chap who will take the trouble to find out why his reg stamps don’t stick is also the fellow who finds out why is car stopped and fixes it himself, instead of spending a good portion of his week’s salary for a tow-in. AuGust, 1929 The Most Useless Thing AMiper whirling machines and flashing electrical appa- ratus at a recent science exposition in New York City, a few ounces of grayish-silver metal fashioned into rods and plates occupied a special glass case in one exhibit—unques- tionably the most useless thing at the show. It was the newly- obtained metallic element “‘columbium,” for which no use is known. Although the metal, first found in a rare Massachusetts mineral, was discovered more than a century ago, last February there were only fourteen grams of it in the world—enough to make one disk a little larger than a half dollar! But today, thanks to a new refining process devised by Dr. E. W. Balke, a chemist for a Chicago chemical and metal manu- facturing concern, twenty-five pounds of columbium are in existence. The question is: Was he wasting his company’s time and money to obtain a useless metal? Useless? Science knows no such word. It thinks of helium, an unwanted gas until someone thought of filling airships with it; or argon, a “white elephant” until the introduction of gas- filled electric lamps; of neon, a worthless rarity once, that today f ashes a scarlet message from thousands of advertising electric signs throughout the land. Columbium useless? Chemists will find a use for it. To- morrow it will join the ranks of the myriad products that make life better for you and for me. It Won’t Be Long Now " OIRE silk cushions and upholstery in cheerful colors mounted with the owner’s initials are charmingly appro- priate in this unique plane interior.” This caption appeared recently beneath a photograph of a luxurious plane cabin in a New York newspaper. And on the woman’s page, surrounded by the latest skirt-length hints from Paris, recipes for brand-new salads and desserts, and advice on summer care for the baby! The innovation is significant. When automobile manufac- turers began to concentrate on upholstery, flower vases, and other trinkets and accessories for their car interiors, the day of universal motoring was upon us. Women, as everyone knows, are the buyers of the nation; at any rate, they are the power behind the buyers’ thrones. The fact that airplane manufac- turers are beginning to consider their tastes and preferences is a sure sign that the day of the family plane is nearer than most of us suppose. They Are Saying— “TD ADIO is going to produce a superuniversity in the United States that will be the greatest educational and cultural institution in all history.”—Major General George O. Squier, retired. “Science, you know, is a lot of fun.” —Dr. A. A. Michelson. “We are not ready for night flying with passengers until we have four-motored planes.’’—Col. Charles A. Lindbergh. “*Man, rather than vermin, is now the chief carrier of dis- ease.” —Dr. Shirley W. Wynne, Health Commissioner, New York City. “I believe in Spinoza’s God, who reveals himself in the orderly harmony in being, not in God who deals with the facts and actions of men.” —Professor Albert Einstein. “Sleeping is something to be learned, just like swimming or dancing.’—Dr. Edmund Jacobson, University of Chicago psychologist. “Every sane man knows that commercial air transport has a real future.”—Elisha Lee, Vice President, Pennsylvania Railroad. “If the earth should move far from the sun, rain would cease and conditions might be so changed.as to make Jife impossible.” —Dr. William Bowie, U. S. Coast and Geodetic Survey. “At thepresent time heredity is not considered of importance as a cause of cancer.’"’-—Dr. Shields Warren, Palmer Memorial Hospital. “It would seem that Nature made every possible mistake before she reached her greatest achievement—man. Or per- haps some would say her worst mistake cf all.”—Dr. Arthur Eddington, Cambridge University astronomer. “The time has passed when men are lured by the hope of finding great tracts of land in the region of the North Pole.” — Peter Freuchen, Danish explorer.

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Avucust, 1929 POPULAR SCIENCE MONTHLY Lnsist that your car be HOUDAILLE equipped Houdailles are not in the experimental stage. because * * They are the result of 27 years of experience in building the hydraulic shock absorber which is now the world’s standard of comparison. because e e Houdailles are easy to adjust. bd 24 é need bec. AUSC.. Houdaille’s double or balanced piston assures supreme riding comfort for years. These X-ray views show the automatic replenishing valve, air vents Houdaille’s patented reservoir automatically re- and the reservoir which holds a reserve supply of fluid and elimi- CCHU“SE ee plenishes the fluid in the working chambers nates the need of packing the instrument against high working pressures. The one moving part of the Houdaille instrument is the double or balanced piston. With pressure chambers on both sides because Houdaille’s patented air vent allows the escape of the shaft, side thrust is neutralized and wear is reduced to the ee of gas and air from the working chambers. Fluid — mixed with air or gas changes viscosity and in a hy- draulic shock absorber causes loss of resistance. Houdailles have been selected on merit by the becau SC.. engineers who build Lincoln, Pierce-Arrow, Cun- ningham, Stearns-Knight, Jordan, Ford, Nash Advanced Six, Chrysler Imperial, Studebaker President, Graham- Paige and many European cars. Your car dealer can supply Houdailles HOUDE ENGINEERING CORPORATION, BUFFALO, N. Y. HOUDAILLE The Houdeille Hydraulic double acting shock absorber is frequently imi- ° tated in appearance. To avoid disappointment, identify the genuine Hon- Hydraulic een en my HOUDE ENG. core.” ~— Double-Acting SHOCK ABSORBERS

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| ‘ i « if ; ~ Bath House $15 Ss w 4 5~3 a") ry i Pe ; } Joe’s pencil was busy for a few minutes, **By Jinks!’’ he exclaimed. ‘‘Looks to me as though you’d come close to justifying the entire car expense.’® ; POPULAR SCIENCE MONTHLY — eh Aucust, 1929 Dollars Your Car Can Save You By MARTIN BUNN N ARGUMENT between’ two customers that threatened to develop into a regular fight was -™- in progress just outside the Model Garage. Gus Wilson stood it about as long as he could. “Hey! You guys outside there!” he shouted, banging on the side of a con- venient pail with a monkey wrench to emphasize his remarks. “Isn’t it hot enough around here without you two spilling all that extra hot air? Joe, see if you can’t shoo ’em away.” Joe Clark, Gus’s partner in operating the Model Garage, and the bookkeeping member of the firm, went to the rescue. “What's it all about?” he interrupted as, pencil in hand, he confronted the two argumentative gentlemen. “Ted, here, is shooting off a lot of bunk about how his car doesn’t cost him any- thing to run,” said one of them. “But it isn’t bunk, Mac,” protested the other. “I know what I’m talking about. Don’t I pay the bills?” “Just arguing won't get you any- where,” said Joe. “Why not do a little figuring and see how it comes out in black and white on paper? If I under- stand you right Ted, here, is convinced that. his car doesn’t cost him anything to run, while you, Mac, claim that’s a lot of applesauce and that your car is running you straight to the poorhouse. Is that the sense of it?” ““You’ve got it,” Ted agreed. “But, Joe,” Mac protested, “Ted can’t possibly be right. You can’t spend money * Ask Gus—He Knows EEPING your foot on the clutch pedal all the time is bad business. It puts '' extra wear on the clutch | throw-out bearing, and évery | time you go overa bump, your | foot pushes the pedal down a | bit and the clutch slips. The | friction surfaces have enough to do starting the car in the regular manner without giving "em extra wear that way. They'll last a lot longer if you don’t, “‘ride”’ the clutch. Don’t have your motor roar- ing when you let in the clutch to start the car. The slower the motor is turning over and the more carefully you let in the clutch, the less the wear on clutch facings. Remember that the clutch is the link between the motor | and rear wheels. It has to | stand the gaff every time you try to jump from nothing to full speed in no time at all. and have it, too, you know. That’s ‘Just a minute, Mac,” Joe broke in. “‘Let’s settle this thing on paper—not with chin music. You've both got the same kind of car and you got ’em about the same time, so we ought to get some pretty interesting figures out of this. Let’s get Mac’s story on paper first. How do you figure your car’s making your pocketbook so limp?” “It’s as plain as the nose on my face,” Mac asserted, subconsciously scratching that rather prominent feature. “I drive about six thousand miles a year, and you've told me before that it costs at least eight cents a mile to operate a car like mine. That makes four hundred and eighty dollars right there.” ** ALL right, I’ve got that down,” said Joe as he noted the figure on a piece of paper. “Anything else you can charge against the car?” “Lots,” grumbled Mac. “Every time we go out for a ride on Sunday we invite some people to go with us, and I get stuck for dinner for the crowd. Every time I drive to a show in the city there’s a park- ing charge added to the cost of the tickets. Because we've got the car we don’t have to take the last train home and that means we go to some restaurant instead of raid- ing the ice box after we get home. “Then we wouldn’t belong to the country club if we didn’t have a car to go back and forth, (Continued on page 129)

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AvueusT, 1929 | PPLE TAS UTS

SE SET IE ROE I I om V,

INTRINSIC IRIN IR IRIS YI

~~ oe i : pli <= = Fhstegrvagh tiy Bechrech MAJOR ‘JAMES E. HAHN President AMRAD CORPORATION, of BOSTON President DE FOREST CROSLEY, LTD., of TORONTO Director CROSLEY RADIO CORP., of CINCINNATI Says: °*Sinee the vacuum tube is the heart of any receiving set we are naturally very exacting im choosing tubes for the testing of AMRAD instruments. Our experience has taught us that RCA Radiotrons give the best results. Consequently we recommend their use in all radio sets bearing our name.’’ tea The widespread endorsement of RCA Radiotrons by makers of quality radio sets is your assurance that they will give you finer reception. Ordinarily they should serve you faithfully for a year

Look for this mark on every Radiotron

of average use. placed in every socket. This complete reequipment is wise be- cause worn tubes are a drain on new ones. RCA RADIOTRON . RADIOTRON DIVISION RADIO-VICTOR CORPORATION OF AMERICA NEW YORK CHICAGO ATLANTA DALLAS SAN FRANCISCO 6) 5 geveg er rer % ) one ars ee 4 ‘i Pe ) w my a 2 5 ANSI IND Vas f i OS a SS 4 “~ 4 2 4 be a LIN UY © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. POPULAR SCIENCE MONTHLY 85 After that a brand new Radiotron should be |

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Novel Mo PRACTICAL way of mounting a divided-hull ship model is shown in the illustrations at the right. Figure 1 shows the upper part of the ship resting on a bookcase top as a water-line model. In Fig. 2 is the same model with the bottom, or underwater portion, attached, and with a % in. thick aluminum plate interposed between the two hull sections. This plate may be removed if the model is to remain as a full-hull model. An aluminum sheet when slightly tarnished has the effect of still water, as in a calm sea. The two-part hull and the inter- posed aluminum sheet also appear in Fig. 3, but with three panels of wood which match the wood and finish of the bookcase and which, when in position, conceal the front and ends of the underwater part of the hull. This gives a model the true effect of a ship sailing, which is not the case when a model has the sails spread and at the same time reveals the full hull. A view of the entire hull in this case is quickly disclosed by removing the three panels. This is easily done, pe canal LIFTS SEIZINGS (THREADS) STARBOARD BRACE REAR VIEW OF SAIL ATTACHED TO YARD) — —, CLEWLINES ON BACK OF SAIL--— FRONT YIEW OF SAIL. Uw (REMOVED FROM YARD) SOFT COPPER CABLE _ STRANDS COILOF ° MAGNET WIRE IMITATION SPLICES BELAYING PIN Method of attaching sails so they can be readily removed; suggestions for wire rigging. POPULAR SCIENCE MONTHLY as they are not permanently fixed in place. A shipshape way of getting sail on a model and also some suggestions on the use of wire standing rigging in place of cord are illustrated at the left. To begin with, the yards on all ships (including the clipper ships, except the very old ones) were provided on the upper side with stout iron rods called “jack- stays,”’ to which the-sails were attached by seizings of marline or rope yarn. In this model a straight wire with bent ends is made, and the sail attached to it by seizings of thread spaced as shown. The wire jackstay with the sail at- tached is removably fastened to the yard by pushing the bent-down ends into holes provided at the ends of the yard; a further fastening is, provided by the swivel hooks AA, which are formed from small brass nails. The blocks for buntlines are seized to the jackstay. The fastenings of braces, lifts, and foot- ropes to the yard is made clear in the illustration. These rigging parts, as well as all shrouds, backstays, and headstays, may be easily made (and set up) from strands of small, soft copper cable, or cable laid up from fine copper wire. This cable is easily untwisted, and part of the strands, when retwisted into smaller cable, may be brought to the correct proportion Aucust, 1929 unt for a Ship Model The Hull Appears to Be Afloat Yet the Underwater Part Can Be Examined—Short Cuts in Rigging This little brigantine, a masterpiece of perfection in all details, can be displayed either as a water-line model with sails or a full-hull model without sails. of the various rigging details. Another advantage of wire standing rigging is that an imitation splice is easily made by twisting the end back on itself. Another use of wire—small cotton covered magnet wire, dyed brown—is the making of neat hand coils to be hung on the belaying pins. The bolt ropes on the sails and all run- ning rigging should be dyed brown. A good effect of weather-beaten canvas may be produced by dyeing the sails faintly with a small pinch of black textile dye dis- solved in water. Tops, Crosstrees, and Blocks N BUILDING two models of the Sovereign of the Seas from PoruLar ScrencE Monruty Blueprints Nos. 51, 52, and 53, I made use of several ideas that other readers may find useful. For the tops, crosstrees, and caps, I broke up some strawberry boxes and glued two pieces together so that the grain of one ran at right angles to the grain of the other. After the glue had hardened, I cut the shapes out with a coping saw and rubbed them down to the proper thickness on a piece of sandpaper. The blocks were made from the hard, close-grained wood of a ten-cent zigzag folding rule. After drilling the wood, I whittled each block with a sharp knife, leaving it on the piece as long as possible. Some of the blocks were little larger than an ordinary pinhead.—T. C. Morris. re en esa. '

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AuGUST, 1929 POPULAR SCIENCE MONTHLY 87 _ FALSE-FACE ON YOUR HANDIWORK! ARE you proud of the things you make of wood? Then why masquer- ade them under a coat of paint or lac- quer? If that desk or table or book- case is worth making at all, it’s worth the finest finish you can apply... Johnson’s Wood Dye, which makes the full beauty of the wood itself a part of your handiwork. Johnson’s Wood Dye contains no pigments. It leaves no muddy scum when it dries. And it goes on without streaks or laps. The colors are true and clear, and they sink deeply into JOHNISON’S WOOD DYE the wood, giving you a finish as per- manent as the wood itself. Instead of a false-face you have the genuine thing ... the wood itself, in all the charm with which Nature endowed it. Our manual on professional wood finishing, showing you how to obtain the brilliant finishing effects you see on fine furniture, will be mailed to you free on request. Just send coupon. S. C. JOHNSON & SON “The Interior Finishing Authorities” Racine, Wisconsin SOSSSOSSSSSSSSSOSOSSOSSSSOSOSSOSOSOOOSD S. C. JOHNSON & SON, Dept. (PSM 8) Racine, Wisconsin Gentlemen: Please send me without charge your manual of professional wood finishing. SOSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSOSOSSSOSOSSSSSSOSOSOOOSOSOSOSOOOOSD

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POPULAR SCIENCE MONTHLY Aucust, 1929 Helpful Ideas for the Car Owner A Handy Floor Board Tool Box—Fitting the Piston Rings—Ingenious Indicators—Locking the Gas Tank

Fig. 1. How to construct an ingenious and simple floor board tool box from an ordinary bread pan. NEAT and simple floor board tool box made from a bread pan is shown in Fig. 1. To install, cut out a piece of the floor board with a keyho!le saw. Underneath the opening nail two strips to form a support for the piece you have sawed out, which wil] be the cover of the box. To this strip fasten four angle iron pieces set as shown in the drawing. If you use another kind of pan—for in- stance, one with straight sides—it will be necessary to rivet or bolt the sides of the pan to the angle iron pieces. The tool box can be located at any point where the play of the springs will not cause any part of the running gear to hit it. An advantage of this type of tool box is that it is concealed by the floor mat and con- sequently there is little chance of tle tools being stolen. Stop Light Indicator HE common method of hooking the dash light in series with the tail-light, using three-volt bulbs at each point, works nicely with the tail-light, but the system does not work with the stop light, which uses a much more powerful bulb, for no one wants a large bulb shining from the dash. The wiring arrangement shown in Fig. 2 eliminates this difficulty. A one-and-a-half-

STOP LIGHT

Fig.?. The prize winner—the arrangement of a novel flashlight indicator that tells condition of stop light. Ten Dollars for an Idea James Pesek, of Chicago, Ill., wins this month’s $10 prize for his sugges- tion for a stop light indicator, shown in Fig. 2, in lower left-hand corner of page. Each month POPULAR SCIENCE MONTHLY awards $10, in addition to regular space rates, for the best idea sent in for motorists. Other contribu- tions used are paid for at usual rates.

Fig. 3. A tin can with top and bottom removed aids in sliding new piston rings into piston grooves. volt flashlight bulb is connected across the wire that leads to the stop light from the stop light switch. When current flows through a wire, there is a loss in voltage which can be read by means of a voltmeter connected at both ends of the wire. The flashlight bulb requires very little voltage to make it glow, and the drop in voltage in the wire leading to the stop light is sufficient to operate it. The beauty of the system is that if the stop light bulb burns out the flashlight cannot light, but if the flashlight burns out it will not affect the operation of the stop light. If the flashlight does not glow brightly enough add a few feet to the wire marked X in the diagram. Installing Piston Rings NE of the simplest ways to fit piston rings to the grooves of a piston is to _ take a tin can slightly smaller than the diameter of the piston and cut away the bottom and the top and slit it on one side. Slide the rings on to the can, as shown in Fig. 3. Push the can down over the top of the piston until the edge of it is at the edge of the l6west ring groove. Slide one of the rings down into the groove. Pull the can back to next groove, and so on.

(oA pat SESW 4mm 41584 S555 NS qeaeemesatemes SSS < TV»

Fig. 4. When the timer contacts are closed, the bulb lights; when they break, the light goes out. Spark Time Indicator T IS difficult to locate the exact point at which the contacts in the timer break and thereby cause the spark in the cylinder. You can, however, wire an electric light bulb, as shown in Fig. 4, to get:an absolute indication of the exact moment when the contact breaks. One terminal of the bulb is wired directly to the battery and the other to the terminal of the coil that is connected to the timer. When the contacts are closed the bulb will light. When the contacts break, the bulb will go out. This method of timing or checking the ignition system is one which will be found helpful not only to the garage mechanic but to the motorist who works on his own car in his spare time. It does away with guesswork, and because of its simplicity of operation saves considerable time on the job. Locking Your Gasoline ASOLINE thieves will be foiled by the fuel tank cap lock shown in Fig. 5. This is an ordinary small cabinet door lock which should be riveted, or screwed and riveted, to the under side of the tank cap. Make sure that the lock does not project far enough to interfere with placing the cap on the tank. Mark where the bolt of the lock comes when the cap is tight down and cut a slot in the in- side of the opening into which it may drop when the key is turned.

LOCK FASTENED TO CAP-, = Se sss RIM

Fig. 5. This fuel tank cap lock is an ordinary small door lock riveted or screwed in place under cap.

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929

Avucust, 1929

POPULAR SCIENCE MONTHLY t Try this Yardstic.

89 Brain

MEASURE YOUR KNOWLEDGE with the - POPULAR SCIENCE |F- | Se mn is talking about the famous “Popular Science QUESTIONNAIRE Questionnaire.” Doctors, Lawyers, Professors, College Grad- : Ly uates and thousands of others have tested themselves with this g 1. Why does radium continue to Questionnaire. In the panel is the list of questions of which the. ; placate cere Questionnaire is composed. How many of them can you answer? 2. Are the stars solid like the : f . —_ eS ae ad Like an Old-fashioned Dr. E. E, Free, who has remarkable < 4. Why is glass transparent? Ex ination genius for condensing the known 5. Hey owe Soom is te am facts about scientific questions in- f & Wienadae... May we ask you to make this to easily remembered paragraphs. . 7. How was petroleum formed? —- test carefully, reading thequestions SPECIAL OFFER : &. Do slestsons realty secs slowly and giving thought to each ze cussent tp flowtuatioanah tt one? When you cannot answerone Tue Pocxer Gute To Science is the | ©. Wastotetnd hepgein your satisfactorily to yourself, puta zero not for sale. It is offered to rn" e Me ilcimanmarmem Mme eS without one penny extra cost wit 11. What are X-rays? ————------—-— On the other hand, give yourself 3 14 go ore stletene wi dx read scm iirc credit of four o) for each satisfac- os RS “a ‘Mo sian *ileds 13. Why does heat expand things tory answer. Then when you are _, * OPULA ah, nt and cold contract them?........--- - ties on” from where Tue Pocketr er 14. Why does the moon appear to through, sie ond near you have Gute To Science leaves off. Tue he change its shape from time to come to making a mark of 100. G ° ll that time? This is lik ‘old-fashioned Pocxer GuIDE gives you a a “ 15. What is the brain made of ——_—- Js Is ike an Old-fashioned €xa- the scientists have discovered up to 16. Why is it possible that the in- mination, but you will find it fas- to right now— Po SCIENCE ' i t rth is growin: : : ° ‘ . PULAR NC) ct | erate Bod yt” aaa a) cinating. The questions all have to Montuty will give you all the im- 7 ] 17. Why is frost more Mhely ona do with the wonders of the world portant, interesting and new dis- al | i tccarayteensersrec we live in. All can be given quick coveries of science for the next 14 “ i 18. Does thinking use up the and straight forward answers by shemelidi i. inker’s energy 2.-.-.-------------------— er < 4 (a “ 19. Which travels faster, electri- oy gemee <8 education. It takes over 300 articles and - a ae ill disti All of the questions in the fa- pictures every month to tell the mea nm Toth pall mous Popular Science Question- feaders of POPULAR SCIENCE ne 21. What makes the noise of thun- naire’? and many hundreds of Monty all that has happened in E 22 whe would men ultimately ge — now been a the scientific, radio, mechanical ' ” suffocate if all the green plants or the first time, in one OK~— and automotive fields. h on, ie teieecmetinces, Tue Pocxer GurvE To SCIENCE. N in Gold y * move the impurities in it? All that you probably ever will Your ame in 10 n at. Ree ee ae want to know about science istold Tue Pocasr Guae 20! Scape ge ta vi a in this one 284-page book that will in beauifal fexible fabrikoid| We wil ~ rom _— = onan fit in your pocket or grace a library cama THE PocKkET GumwEe at no extra TOTAL PERCENTAGE... table. Curiosity-satisfying facts cost to you if you use the coupon below about the world weliveinaremade immediately. y a instantly availabletoyouinsimple We omen to you the Seecial Ofer of B " question-and-answer form in Be Bogs catin (regular price by the - ga iN Tue Pocxet Guiwe To Science. h would be $3.50) with the Tur Poc- r = i Into this one mont yf \ oeitieatbook You are assured of the ac- oe Guwe See ~ sree is : re alre - k | \ has been con- curacy of the answers in THE oe ngs bac p che «ppm Fp mem “s cueadinn P OCKET GuIDE To SCIENCE be- your subscription 14 months if you accept k factsabout cause it has been edited by this offer. the world we live in. SEND NO MONEY Send no money, just the cou- pon. If within 10 days after you receive the book and magazine | you decide that you are not sat-

postman $2 95,P and the first ieee fully satisfactory tO TE

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; i = ee ee POPULAR SCIENCE MONTHLY Aucusr, 1929 When Front Doors Need Paint As They Do Frequently, You Can Refinish Them Yourself so They Will Not Blister or Crack by Following the Hints of F. N. VANDERWALKER UTSIDE doors and floors are subjected to the hard- est service and- conse- quently require more at- tention than other surfaces of a house to keep them from looking shabby. The refinishing of doors once or twice between paintings of the outside or the inside of the house saves the housekeeper con- siderable anxiety about -appear- ances. After all; guests gain their first impression from the general aspect of the entrance. Refinishing doors is one of the tasks any handy man can do well, thereby saving money and avoid- ing the inconvenience of having to hunt up a professional painter who may not be especially en- thusiastic about doing small jobs of this kind. Tn a previous issue (August, 1928) of this magazine, methods for applying an enamel finish to outsicle doors were described. It should be of interest also to know how to apply a high-grade paint finish, which’ costs less and is easier to apply. As a rule the old and soiled painted surface is in good condi- tion as far as soundness of foun- dation is concerned, but often the paint is chalking off. Such a surface needs to be sandpapered just enough to clean and smooth it. When a stained and varnished door is to be painted instead of revarnished, it should be sandpapered well to cut off any gloss or crumbling varnish. It is not nec- essary to remove old varnish that has merely become duil in places, but it should be sanded enough to make it uniformly dull. The same is true of old enameled surfaces. Doors which were merely oiled, or stained and oiled, require sandpapering. If they have been allowed to weather until the wood has checked and opened up and raised in ridges, considerably more work Beautiful entrances such as this lose much of their charm if they are not kept clean and freshly painted. They must be repainted more frequently than the remainder of the house. is called for; they should be sanded with No. 1 paper wrapped around a block of wood until the ridges and rough places have been made smooth, and finished with No. 4% or No. 0 paper. The sanding of painted, varnished, and enameled sur- faces that are in sound condition may be done with No. 4 paper. Any first-class house paint is suitable for doors. At least two coats should be applied, and three coats are well worth the slight additional cost. In painting doors that are exposed to the direct rays of the sun and therefore might blister badly if the undercoats were too rich in oil, the point to be careful about is to use the least possible amount For applying the paint you need first of all a good quality brush 2 or 2 4in. wide with long bristles for edges, panels, and flat surfaces. of oil in the first and second coats. If you use undercoats that are rich in oil, they are too elastic— more elastic in time than the fin- ishing coat of the same paint be- cause the weather reduces the elasticity of the finishing coat be- fore it affects the undercoats. When the surface gets hot, the undercoats expand more than the finishing coat and the surface may be marred by blistering or “alli- gatoring.” If you use ready-mixed house paint, you can reduce its elasticity for the undercoats by this method: Pour off into a separate can the oil that has risen to the top and take out one half or one third of the pigment, depending upon whether you are to apply two or three coats. Mix the pigment for the undercoats with turpentine only, but for the last coat mix the pigment with oil alone — that is, the oil drawn off when the can was opened. If you are to use white lead paint, mix the lead for the under- coats with turpentine only and mix the last coat with about one fourth turpentine and three fourths boiled linseed oil. In case you want a light tint rather than white, add to the lead the desired tinting color ground in oil; this comes in 1-lb. cans. For very dark colors such as dark green, use ready-mixed paint of the color wanted for all coats, or use white lead undercoats tinted about half as dark as the finishing coat is to be, and then use for the last coat a tinting color, such as medium, light, or dark chrome green, thinned with about one fourth turpentine and three fourths boiled linseed oil. When a door with varnish upon it—or any other varnished surface—is to be painted, and assuming that the body var- nish is still firm, the first coat of paint should be mixed (Continued on page 118) i | To cut neatly around lights of glass and for other delicate work, you should have a round or flat brush 1 in. wide, known as a sash tool.

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Aveust, 1929 C&L 32 satisfaction. : You're investing in better and longer performance when you buy a Clayton & Lambert © AN EXPANDED gas orifice makes a blow-torch a piece of junk. And it’s the easiest thing in the world to enlarge the orifice in an ordinary torch. But a No. 32 Clayton & Lambert blow-torch has an orifice that can’t be en- larged — no matter how carelessly or how tight you close the valve. It’s a patented Clayton & Lambert improvement—one reason why you get longer service when you buy a Clayton & Lambert. In addition to being non-spreading, the orifice will not clog. As you close down the valve the carbon cleans out automat- ically. The improved orifice is but one of many Clayton & Lambert advance- ments. Every bit of mechanism is de- signed to give you quicker, better action. . Inside and out, a Clayton & Lambert is built for long, strenuous use. Where a This is one of the most popular blow-torches we have ever made. It is more expensive than the 158 because it is made for much harder use. It is designed for the man who uses a blow-torch in his daily business and demands not only excellent performance but rugged ability to stand rough handling. 32 contains the most advanced, patented C&L blow-torch improvements. It also has a red handle with a gold stripe. Sure sign of POPULAR SCIENCE MONTHLY C&L 158 This blow-torch is especially made and priced for the man who likes to do odd jobs around the house, or to tinker with mechanical things. It will last a lifetime if it is not abused. The us retail price is about five dollars. Most hardware, electrical and automobile accessory stores have it—or can get it for you quickly. Look for the gold- banded, red handle. © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. hard bump might occur, a Clayton & Lambert is rein- forced. Wherever extra protection should be—you'll find it in Clayton & Lambert. As an example, all Clayton & Lamberts are made non-explosive by a patented method of building the fittings into the tank. The vaporizing chamber is another Clayton & Lambert fea- ture. Its special vein system gives you quicker heat—more heat—and cuts down your fuel bills. You can’t see these things which Clay- ton & Lambert have done to give you the blow-torch you want. They’re inside—in the “works,” the important part of a torch. But they’re there—along with numer- ous other refinements. They ac- count for superior performance and durability. And that’s why Clayton & Lamberts are the most popular torches in the world. You'll know a Clayton & Lambert by the red handle with a gold stripe. CLAYTON & LAMBERT MANUFACTURING Co., Detroit, Mich.

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The metal working bench is located in a corner at the left of the engine lathe. Screws, bolts, nails, and small hardware are kept in glass jars. Above the bench are racks for hammers, wrenches, and many other tools, including a large num- ber of auger bits, which are hidden by the shelves. Planes are stored beneath. The thoroughly modern engine lathe has a swing of 12 in. and a bed 5 ft. long. Dr. Scofield has a complete and costly collection of tools and attachments for use with it. Hew does your workshop com- pare with Dr. Scofield’s? Even if far less complete, it may be noteworthy for its arrange- ment, neatness, convenience, or some special feature. Send a photograph or photographs of it, accompanied by a brief de- scription, to the Home Workshop Editor. For each photograph that is found suitable for pub- lication, five dollars will be paid. POPULAR SCIENCE MONTHLY Doctor Owns Marvelous Little Shop ert eee Ed ge ‘ e . pS aa i. Aucust, 1929 Richard J. Scofield, M.D., of New York, in his extraordinarily complete home workshop. He estimates that he has fully one thousand tools. He finds relaxation from his exacting professional duties by working at his engine lathe and doing a variety of cabinetmaking, metal spinning, and decorative and hammered metal work. The cabinetmaker’s bench is shown at the right above. The drawers are filled with tools. On the other bench is a small lathe of 4-in. swing and with a 2 ft. 6 in. long bed. A grinding head with carborundum wheels is mounted on the same table. Heavier grinding is done on the grind- stone. Each machine has its own motor. A small band saw, a circular saw, and a jointer are shown at the left. All Dr. Scofield’s small machines, including the speed lathe in the view above, are mounted in such a way that they can be rolled into a convenient position for use. His shop is too small to allow each machine to have its own fixed position.

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929 Aveust, 1929 POPULAR SCIENCE MONTHLY 93 _ How to Use Your Back Saw _ Told by the Makers of “The Saw Most Carpenters Use” T is Disston Steel and Disston Skill that make Disston Saws supreme. Steel made in the Disston Steel Works puts stamina, toughness, long cutting life, into every Disston Saw, Tool, and File. Disston Skill gives better balance to every Disston Back Saw; makes Disston Hand Saws lead the world; and maintains Disston leadership in compass saws, dovetail saws, coping saws, and other small saws for every purpose. No other saws can give you such lasting satisfaction. Ask for Disston! Hand Saws, of course; and every other type of saws for bench or machine work. ” Files for the Wood Worker “TheSaw aspen: ee mated i Cabinet Files (fine teeth) for smooth- The two handiest saws for the home work- ‘ ig and fishing wood surfaces, easing tht aap oe te Sale peer wor caine: a rs, etc. * Disston n ing. me | tp es tench la se ce na “4 pn tery ay Bong Flat 8° Wood | 50c. other styles and sizes to choose from. by i , a | ag, ck. | OU must have a back saw if you expect to do accurate : cabinet work, cut mitres, grooves, mortises, moldings, etc., or do careful joinery. You should also have a bench hook, (below), for holding the work firmly. You tan also use a back saw in a mitre box. In using a mitre box, be sure slots in box line up with the cut to be made. Hold work against back of box and start cut carefully with a back stroke, holding handle slightly Handiest of Pocket Levels upward. After cut is started, gradually level the saw and Band Saws for Better Work For truin struction work. levellin continue the cut with blade horizontal. Hold saw firmly : : oa Fuing up const 8 . . Disston “Thin Ga Narrow Band Saws shelves, etc., use a Disston Featherweight for clean, straight and accurate cutting. are 2 to 3 = ailinin, Site um tateer Pocket Level. It is the lightest and handiest oneal ana eheaks up to on” naan, | args a ce hoe pees a In using a bench hook, have it at left Saw 9 8” long, 14” wide, 25-gauge, brazed, : - siaiamimabian of cut to be maae. In making mortises, $2.03. Other sizes in proportion. tenons, etc., after starting cut, keep saw level and watch depth at both ends. Use a light, even, level stroke. Leave line, or part of line, on the finished work. Use two bench hooks to support long material. The new Disston Back Saws have heavier backs, to stiffen the blade, keep it straight, and hold the teeth in the cut. Teeth are shaped and set to cut smoother and easier. Blade and handle are balanced to insure better work. he Disston No. 4 Back Saw is made with 8, 10, 12, 14 and 16-inch th | blades. The 12-inch blade, 3 inches under back, toothed 14 he points to inch, is handiest for the home workshop. It costs $3.00. ng ' Good hardware merchants everywhere sell Disston Saws. m | le. | d- | For Cutting Dovetails, etc. For Your Power Saw Outfit ae Wherever the finest possible joint is needed, Disston Saws insure better work. Cut easier, : and for dovetailing, pattern making, etc., use stay sharp longer. Disston Circular Saws thi aga _ 68 Bovetai > - extra yyy ue | gy fi pm in, with fine teeth. The 8” le, 1 ints to fit. any make of machine. your dealer to inch, is most popular. $1.60. “ Makers of “THE SAW MOST CARPENTERS USE” cannot caaly you, write to us for prices. a ir ee oe oe ee ee ee oe oe we oe oe oe ee ae ee ee ee ee ee ce ce ee re ee ee ee ee eee ee ee ae ee ee ee ee ee ee ee ee we we we oe es Henry Disston & Sons, Inc., Philadelphia, U.S. A. in . Every saw user will enjoy reading “The Disston Saw, Tool and (In Canada, address Henry Disston & Sons, Ltd., Toronte) or File Book,” an illustrated manual on the selection, care, and use Please send me “The Disston Saw, Tool and File Book.” +h of tools. It tells how to file and set saws, etc., and contains helpful n, information on band and circular saws. Use coupon, or write. Name and Address © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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© 1929, Liccerrt & Myers Tosacco Co, 94 POPULAR SCIENCE MONTHLY Aucust, 1929 ...on the floor it’s ME / FINE TURKISH and DOMESTIC tobaccos

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929 Avcust 1929 POPULAR SCIENCE MONTHLY 95 ..In a cigarette it’s TASTE/ * TASTE above everything When it comes to taste, the really fine cigarette begins where the average ciga- rette leaves off. Something more than ordinary tobaccos and routine care are needed to produce the aroma and charac- ter that are Chesterfield’s own. * + Not ordinary tobaccos, but tobaccos chosen, one by one, in ail the leaf markets of the world, for flavor, richness, mild- ness... tobaccos matured and mellowed by ageing, in Nature’s perfect way. + @ ¢ Not routine care, but tobaccos blended to scientific balance, to bring out the finer qualities that make acigarette—and ‘‘cross- blended,”’ the Chesterfield way, to round out and perfect the delicious flavor. ¢ & Chesterfield is much more than ‘‘some- thing to smoke,”’ just because each step is governed by taste, above everything. And long experience has taught us—and Chesterfield smokers as well—that a really fine cigarette can be made by no other rule. - field -...not only BLENDED but CROSS-BLENDED - rive Bs nal sek MILD... and yet «+ « THEY SATISFY OS

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“aa That Help You See Better Magnifiers and Small Mirrors | Will Save You from Eyestrain and Insure Greater Accuracy— Novel Ways to Use the Camera By HENRY SIMON LMOST every shop boasts a magnifying glass or two. Occa- sionally that glass is dug up and / used, but generally speaking, mechanics are averse to having anything around of which the “vitals” are glass. Not without good reason, too, for glass and metal don’t mix very well. A more liberal use of optical aids never- theless is one of the biggest “boosts” a mechanic can give himself. The draw- backs can be overcome, partly by getting used to handling “tools” made of glass and partly by making devices that will allow them to be taken care of easily. Then, too, there is a good deal in a proper choice of these “glass tools,” and even more in knowing when and how to apply them. In magnifying glasses, for example, what is the maximum combination of low price and high performance? A very good team is that of A, Fig. 1, page 98— a 4- or 5-in. reading glass with large field and low magnification, and a 10-power glass for detailed work. Do not be sur- prised to learn that the small 10-power glass, about % in. in diameter, costs twice as much as the large reading glass, be- cause if it is really good, that small glass is composed of three lenses as at B. Perhaps the best magnifying glass for all-around use is one marked “6x,” meaning that it magnifies six times. It has a fair field of vision, good power, and is always easy to handle. A 14-power glass, on the other hand, will generally mark the useful limit of magnification for shop use. With any but fairly large and therefore low-power glasses, there is difficulty in keeping them per- fectly clean, especially when much oil is used, as in hardening rooms, screw machine departments, and similar places. The oil enters the inner corner of the raised rim and thence spreads over the entire sur- face, no matter how many times it is wiped off—and the wiping is the more tiresome the smaller is the gless. A homemade mounting for a cheap glass that will do away with this difficulty is shown in Fig. 2 at B. It is a plain ring of aluminum or fiber with cupped surfaces that just meet the edges of the lens. The lens itself is a push fit in the fiber POPULAR SCIENCE MONTHLY Using a reading glass to follow the progress of a fine cut on a lathe. The holder itself is shown in detail on page 98, Fig. 5. ring, and it may be set in varnish in the alumi- num one. In either case, the ring should be care- fully blackened all over. An easy-to-clean setting, which pro- tects the lens while in use as well as the standard kind, is that of Fig. 3. The handle may be made of fine hardwood or light metal. The lens setting proper is similar to that just described. The two spring rings guard the glass from damage when it is put down anywhere, but can be instantly depressed to permit wiping off the lens. A good way to rig up a reading glass for steady use and still allow it to be removed is that of Fig. 4. Placed con- veniently in a dark corner of a room, the lamp gives brilliant and even illumina- tion, and no handling of the lens is necessary. Did you ever follow the progress of a fine cut on the lathe with a reading glass? If not, try it the next time you have one of those superfinicky jobs, and see how much nervous tension it will save you and how it will speed up some kinds of work by eliminating guessing. The glass may be held by hand, or you may rig up an easy-to-put-on and easy-to-take-off holder right on the tool post, as in Fig. 5. Besides giving you a picture of the cutting operation such as you cannot get A photograph of an intricate set-up makes a perma- nent record in case you have to duplicate the work. Aucusr, 1929 otherwise, this arrangement will also guard your eyes from flying chips. At A, Fig. 6, is shown a headgear made of wire, which obstructs very little of your ordinary vision. At B is illustrated the same idea applied in the shape of a clip for an eye shade; in: this case the holder also forms a handle when it is desired to use the lens by hand. Finally, there is a very convenient rig for those who wear glasses in the clip at C. HAYS G good magnifying lenses is one thing, but proper illumination and the right way of viewing objects is another and hardly less important con- sideration. Good sunlight from the cor- rect angle is usually the best illumination, but it is not always to be had. The light of an electric Jamp, properly used, is on the whole preferable. The background against which the object is viewed is another point. The poorest background is a neutral or non- uniform one; black and white are equally good if it is remembered that the illumi- nated edge—usually the upper edge—of an object should be viewed against black, and the unilluminated or lower edge against white, for the reasons appear- ing in Fig. 7. You may save a lot of eye- strain by remembering this _ simple point, especially in viewing threads. By the way, how should a thread be viewed; as at A, Fig. 8, or as at B? It is remarkable how many misconceptions there are in regard to this point. Without going into the “why’s,” there is no dif- ference with any ordinary screw thread in which of the two ways it is viewed—at least when the viewing is done “ by hand.” With steep threads, which may be either multiple or threads of heavy lead, the viewing should always be in the direc- tion of the helix angle, as at B, for the reasons which are made clear in the drawing. It is well to remember on general principles —_ (Continued on page 98)

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1929 PONS wR 0's Iso ide of | ted the is ly, ose is on is or- yn, tht on he yn- lly ni- -of ge ir- le be ns ut if- f in POPULAR SCIENCE MONTHLY ee Aucust, 1929 Ll 7 or 7000 H. P. — they depend alike on Starrett Accuracy able as the world’s greatest toolmakers No matter what the size or importance can make it. of the job — no matter whether you use tools in your daily work or at home, for fun, you want things right—one hundred per cent right! Starrett Tools are worthy of your highest skill, and always will be throughout years of constant use. You may select any one of the more than 2500 Starrett Tools knowing that it is as accurate, as depend- That is why Starrett Tools mean good work—why using Starrett Tools stamps you as a good workman, the world over. Have you a copy of the ‘great Starrett Catalog containing full descriptions, ill- ustrations and prices? If not, send for your copy, free, today ,No.24“W.” +. - THE L. S. STARRETT CO. World’s Gr - a -_ 8 MGeoal Tapes Standard for Accurecy ‘5 ATHOL, MASS., U.S.A. 97 Starrett Pocket Slide Calipers, No. 425, with improved clamping lock; for inside or outside measurements. The popular No. 436 Starrett Micrometer in one inch sizes up to 12ins. and in sets. Furnished with or without lock nut, ratchet stop and half thousandth divisi- ons. Starrett Combination Square No. 94 — eight tools in one—mark- ing gage, rule, uare, miter, epth gage, height gage, leveland plumb. Starrett © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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98 POPULAR SCIENCE MONTHLY Aucust, 1929 Tools That Help You See Better (Continued from page 96) Figs. 1 to 4. Magnify- ing glasses used in the shop; settings and holders; reading glass hung on light shade. Figs. 8 to 10. Various ways to study a screw thread; defects re- vealed by magnifica- tion; uses for a mirror. that although optical projec- tion is an excellent way of checking screw threads, no point of view can ever give the exact theoretical outline of the thread. The mechanic who once makes up his mind not to pass by the benefits offered by op- tical instruments will find many further uses for the magnifying glass, some of which are sug- gested in Fig. 9. Looking over the cutting edges of a reamer or tap through a 10-power lens will give a new idea of the im- portance of having tools sharp. It will explain why the highly- finished gaging or wearing sur- face at A will lust several times as long as a poorly-fimished one at B. It will solve the puzzle of why, by merely putting a high finish on the surface of the cutting edge on a drill or bit as at C, it can be made to outlast the one at D, sometimes six to one. It will show cracks in hardened parts, such as the die at E, and explain the cause of failure of many a hardened, rolled, or forged piece. Second in rank among the optical helps for the mechanic is the mirror. This may be either plane or convex and mag- nifying. Before you kink your neck the next time in a vain attempt to find what is the matter with some inaccessible part of a machine—as, for example, the underside of a projecting arm—see if you can’t save time and trouble with the help of a fifty-cent pocket mirror, as suggested at A in Fig. 10. A mirror of similar size, but of the convex or magnifying kind, will Figs. 5 to 7. Reading glass holder for lathe; wire lens holders; backgrounds for magnified objects. be equally handy in concentrating a beam of bright light on some corner or recess when a flashlight is not on hand or where the space is too small to use one, as shown at B. And incidentally, such a magnifying mirror is a mighty good “first aid” accessory when something is in your eye, as sug- gested at C. One of the best uses of mir- rors, either plane or concave, is for the steady illumination of fine scales on machines or instruments which are otherwise hard to read. Here the mirror has the advan- tage of putting the light exactly where it is wanted, yet without occupying much space. As in- dicated at A in Fig. 11, a plane mirror will illuminate a certain surface, while a concave one will give greater intensity of light on a smaller area. Whichever is used, it is essential to have some readily adjustable mounting for the mirror. A cheap and quickly made one is that at B, improvised from a small block of hardwood and a piece of soft copper wire. By turning the block and bending the wire, the mirror may be instantly adjusted to any angle. A more permanent mounting, but one which is, also more trouble to make, is the double ring at C. A plane mirror occasionally may be rigged up with good effect on the lathe or miller to aid in some delicate finishing operation, as illustrated by the example at A, Fig. 12. Another mirror may be used to light (Continued on page 123) Figs. 11 and 12. Méirror holder of wood and wire, a double ring mounting. A\ use of mirrors in machining’ eon Aart hy

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Avoust, 1929 POPULAR SCIENCE MONTHLY 99 N present day precision work where accuracy is figured in terms of thou- sandths—even ten thousandths of inches only the finest tools can stand the pace. To meet the demands of skilled mechan- ics for accuracy in tools, Brown & Sharpe has long produced precision tools which comply with the most rigid standards. It is a tribute to this effort that Brown & Sharpe Tools have become known as the “World’s Standard of Accuracy.” Micrometer Depth Gauge No. 607 shown above is a particularly serviceable and handy tool. It is furnished with three measuring rods which give it a range from 0 to 3” by thou- sandths. This tool as well as over 2300 others are shown in the new Brown & Sharpe Catalog No.31. Ask your hardware dealer for a copy or write to us for one. Address Dept. P.S., Brown & Sharpe Mfg. Co., Providence, R. L, U.S. A. _ (Bs "“WORLD’S STANDARD OF ACCURACY” BROWN & SHARPE TOOLS © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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100 Built for Men Who Know! PEXTO Screw Drivers are built for men who know good tools. Sturdy, well-balanced, it’s a pleasure to grip one. Ownership brings an assurance that is sure to reflect itself in the job at hand. And PEXTO Screw Drivers are typical of the whole PEXTO line. Send for booklet “S.” It contains useful information on the care and use of all kinds of small tools, and pictures many of the PEXTO: Hammers Screw Drivers Snips Wrenches Pliers Squares Chisels Pruning Shears Braces “It Pays to Say Pexto” THE Peck Stow & WILCOX COMPANY Southington, Conn., U. S. A. POPULAR SCIENCE MONTHLY Avucust, 1929 \ Y Kp YY) \ ma USI : AN A> rn Wy Ay Ate \ a i 7 = Ky Wome ig oe [a LS VAG Ss TNs EX . Aa AK RCS Le a ty, ~ Ss . “i The seashore is doubly delightful when you have adequate beach furniture and protection from the direct sunlight. More Comfort at the Beach How to Make a Back Rest, a Sand Table, and a Sun Shelter or a Parasol Holder By Hi Sisitey = recreation if one does not have to pay for it in sunburn, a lame back, and gritty sandwiches. These drawbacks can be avoided by making beach furniture of the kind illustrated. The back rest is one of the greatest comforts. Essentially a steamer chair minus legs, it is so easy to make one can- not afford to be without it. White pine is desirable for the side members because of its light weight, and it will be found strong enough for the purpose. Before [= G all day on the sands is a fine Folding beach equipment which can be made with little difficulty and at trifling expense. assembling the framework, slip the round cross members through the hemmed ends of the cloth, which can be purchased from an awning manufacturer. A piece about 16 by 52 in. is required. As a standard beach umbrella is expen- sive, you can save money by making a staff with a socket to support any straight-handled parasol available—for example, a Japanese parasol, which is light and durable. A section of brass tubing of the desired diameter is ideal for the socket, but lacking this you can make one from a piece of sheet brass, copper, galvanized iron, or even tin. The little beach taboret is handy for keeping food, beverages, or sewing basket out of the sand. Fasten the pine block on the underside of the plywood top by driving finishing nails through the top. A section of broomstick or any round stock will serve for the leg. For protection from sun, wind, and sudden showers, a folding beach shelter is always useful. The principal expense is the cloth. Ordinary unbleached muslin will bring the investment down to a minimum. Bolt the crossbars so that they can be folded together and rolled up in the cloth, together with the 6-ft. or longer stringers. From personal experience, I recom- mend painting all woodwork some bright color, such as red, blue, or green, for on a crowded beach there is so much other equipment and often driftwood of a neutral color that it is not always easy to locate your own property, once you wander away from it. © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. =

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1929 aT es ite it. CR tet het ST SS we = ] FF AucustT, 1929 Cy a true picture of this rapidly developing industry. See the opportunities it offers young men. Clip the coupon and mail for your free copy of the book “Aviation— What It Means to You.” Read in this book the thoroughness with which students in Universal Avia- tion Schools are trained as Aviation Mechanics and Pilots. See why fly- ing training will place you at a big advantage although you may en- gage in one of the many other lines of aeronautical work. Familiarize yourself with the various aeronau- tical terms as explained here. This Universal students taking book is interesting- Course work on all types ly written, truthful of motors including latest air cooled makes. in all respects, full of illustrations and honestly helpful to you in planning a way to enter this field of big, new opportunities. Send for your copy—FREE—today. Background of Universal Aviation Schools Universal Aviation Schools form a national system, individual schools being located in a number of key cities and all schools Pxsgivation sng ratine offering the same ™%nivemafSchoos. @ POPULAR SCIENCE MONTHLY courses and high type Sasi*itic Wesne of training. These “™ sa” “ schools are owned and directed by the Universal Avi- ation Corporation,a concern which, with its affiliated lines, covers over 17,500 miles of airways a day carry- 101 carn the Way to get started in Aviation ing air mail, express and passengers. Having the tremendous resources of the Universal Aviation Corpor- ation behind them, the schools have been provided with the finest equip- ment obtainable and the most com- petent instructors in the country. Insurance Provided for Universal Flight Students Only new production, government licensed’ planes and thoroughly ex- perienced government licensed transport pilots are employed in Universal flying training. The re- markable safety of Universal train- ing is shown by the fact that Uni- versal flight students were the first to be offered complete insurance protection throughout their train- ing byan established insurance firm. This insurance assists you in secur- ing financial backing to learn to fly. Fulldetails are explained in the book “Aviation — What It Means To You.” Mail coupon for your copy. Universal Aviation Schools Robertson Flying School, St. Louis, Mo. Mid-Plane Flying School, Minneapolis, Minn. Egyptian Flying School, Marion, Ill. Porterfield Flying School, Kansas City, Kan. Central Flying School, Wichita, Kan. A class of stu- the Aviation Business Course. Universal Flying School, Rochester, Minn. Universal Flying School, St. Pau), Minn. Universal Flying School, Memphis, Tenn. Universal Flying School, Cleveland, Ohio Braniff Flying School, Oklahoma City, Okla. ass ane A Division of Universal Aviation Corporation ‘ UNIVERSAL AVIATION } Universal Aviation Schools ‘ Pe Suite 1046-55 Boatmen’s Bk. Bldg. ° ‘& eters St. Louis, Mo. Please send me at once your free book, “Aviation —WhatIt MeansTo You.” Laminterested in: OFlying Course 0 Aviation Mechanic’s Course DC Business Course

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102 POPULAR SCIENCE MONTHLY Aucusr, 1929 JLVM Hand Forged TVVLS Nationally Known for StrengthandWear. Hand-forged from selected chromium, molybdenum and Tungsten steels. Heat- treated to give greatest hard- ness and strength. YOU’LL WANT THIS KIT EVERY Mechanic and handy man needs a few extra fine Punches and Chisels in useful sizes. Plomb Tools for sale by leading Auto, Aviation, Plumbing Jobbers and Hardware Dealers. Fully guar- anteed. If your dealer can’t supply this No. 3 Punch and Chisel Kit we will send it prepaid from our nearest office, upon receipt of $1.90. 6finetools: Regular, Cape and Diamond Chisels, 2 Rivet and 1 Center Punches. & check or Tr. a PLOMB TOOL COMPANY Los Angeles 2209 Santa Fe Ave. New York 4906—36th Street, Long Island City 1146 West Lake Street 2705 Williams Street ‘Chicago Dallas Gentlemen: Enclosed is (M. O.) (Check) for $1.90 for which please send me the above No. 3 Plomb Punch and Chisel Kit, postpaid. .th ne Khahne ede enseneeeees cecewenic Eb eédvectosneccbbescenenene UCCESS or failure in fishing is often a matter of knots and _ hitches. Those who have experienced the dis- appointment of having a prize catch—or one that looked like a prize—dash away with the bait simply because a supposedly secure knot had slipped will understand the truth of this statement. Every angler should know the best methods of splicing or forming loops in Fig. 1. In tying a compound loop, an ordinary running knot is first formed. Heavy cord has been used for clearness. Fig. 3. This is the compound knot when drawn tight. It will not slip or break easily. Fishing experts have found it superior to the well-known bowline because the line is bent less sharply when forming the knot. Fig. 5. The ends are passed through the central twist or opening; one is shown through, the other about to go through. Fig. 7. An excellent hitch for attach- ing a line to the loop of a leader. Fishermen’s Knots Fig. 6. The twist knot when pulled tight. It is con- sidered by many anglers as the best knot of its kind. - By Water E. Burton his lines, leaders, and snells. While there are eight different knots that cover all of the ordinary demands of fishermen, two or three are of outstanding interest and should be used in preference to others when possible. For forming a loop on the end of a line or snell, there is nothing better than a compound knot (Fig. 3), according to one of the leading authorities on fishing tackle. Of course, you can use the simple loop knot that everyone knows how to tie, but it is not quite (Continued on page 118) Fig. 2. The free end is looped over the main cord and over a part of the first knot made; then it is carried under the remaining parts, Fig. 4. The first step in tying a knot in gut leaders is to carry each end twice around the other in opposite directions. © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. A nme go

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rts, Speed, power, durability, light weight—the features that have made Millers Falls Drills outstanding in the electric tool field—have been built into this new, up-to-date power tool. Here is a Drill with Millers Falls quality for only $25.00, an inexpen- n sive electric tool for light service around the house . and shop. meer y NEW YORK: 28 Warren Street FOR ONLY $25 : YOU CAN GET MILLERS FALLS QUALITY IN A DRILL For illustrations and descriptions of the whole electric tool line send for the new Electric Tool Catalog. Write today. There is no charge. MILLERS FALLS COMPANY MILLERS FALLS - MASSACHUSETTS © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. Aucust, 1929 POPULAR SCIENCE MONTHLY MILLERS FALIS TOOLS Think of the hundred and one things you can do with this drill. And for only $2.50 extra you can get a bench stand that will double its usés. Make a note now to look at this new power tool, to handle it, to see what it can do. Try it on your own work under your own conditions. Test it in comparison with any other electric drill of the same price and draw your own conclusions. CHICAGO: 9 So. Clinton Street 103

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104 POPULAR SCIENCE MONTHLY Aucust, 1929 Photographed just as re- turned after 44 years of services -and only a rivet worn out! Pliers purchased in 1885 by Mr. H. S. Meacham Says Mr. Meacham: **They are just as good as new, except that the small pin that holds the jaws together has broken... ”’ ~ Old pliers, old friends of Mr. Meacham, you were a “Be S” money’s-worth! Only toolsof yourcharacter can leave the forges of Reproducing an Old Chais You Will Find It Easy to Build This Charming ‘«‘Ladder-Back”’ Even If You Do Not Own a Lathe By FrepDERICK J. BRYANT of Germantown, Phila., Pa. | | S “ladder-back”’ chair, which takes its name from the arrangement of the slats forming the back, is a good specimen of some of the earliest chairs made in this country. Chairs of this type, because of their decorative appearance and Colonial associations, are popular and in demand for use in a hallway, living room, or bed- room. They are not, it must be admitted, espe- cially comfortable. The design illustrated was chosen because it is not difficult to copy. The back legs are plain except for the upper ends. The ir- regularly shaped knobs may be part of the legs or turned separately. Another feature is the fact that this chair can be made without a lathe. It may be well to cut and fit the mortises before round- ing over the legs by hand or turning the stock in a lathe. If the stock is left square until the slats are fitted into place and the holes are made for the rounds, it is a simple matter to lay out the work. Soft pine fillers can be placed tempo- rarily into the mortises if the legs are to be turned. The fillers will prevent chipping near the edges. All of the mortises and holes should be about % in. deep. 2B ee ot Measured drawings of a genuine Colonial ladder-back chair of excellent proportions and unusual simplicity. Handmade reproductions of this type of chair are highly prized for their decorative quality and antique look. Wooden dowels or pins are used to strengthen the slat joints. To make the back legs by hand, plane the stock exactly square with the ‘base 13{ in. and the top 17%, in. On the larger end measure in from each corner exactly ¥ in. Connect these points cornerwise and you will have laid out an eight-sided figure—an octagon. Do the same on the smaller end, measuring 7% in. instead of ~ Y%in. With the aid of a straight » stick, draw lines the full length of the posts to connect these cor- » ner measurements. Now plane _ or bevel the corners of the leg, - being careful not to cut below _ the bevel lines. All of the bev- _ els should measure about % in. wide at the big end. S THE next step, remove the remaining corners witha plane. The knobs at the top can be omitted if necessary. After. this comes the scraping, filing, and sandpapering. The front legs are made in the same manner. The seat rounds are % in. in diameter, and on them is woven the rush or fiber seat. Rush was used on the original, but fiber is easier for the amateur to handle. Simple printed direc- tions are usually given with the fiber when it is purchased. The chair rounds below the seat are 34 in. at the ends and lin. in (Continued on page 119) © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. inet hance NEE OEP

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Sc a ee ee en, ES ee i ee ee) Aveust, 1929 POPULAR SCIENCE MONTHLY 105 “The Von Hoffmann Graduate Qualifies” Will Give You a Thorough— Practical Training The training which the Von Hoffmann student receives is the exact training which he must have to qualify for immediate positions on the ground or in the air. The cost is low considering daily flying, the thoroughness of theo- retical and ground instruction on latest modern type planes, Wright Whirlwind and other standard motors. OUR INSTRUCTORS ARE EX-ARMY PILOTS EACH WITH OVER 3000 HOURS OF FLYING Our School esi All Instructors and Airplanes Licensed by U. S. A a Government, Aeronautics PROUD OF Branch, Dept. of Commerce Our record to All Airplanes used by us for both instruction and date shows that passenger service are planes licensed by the U. S. every Von Hoff- Government and our instructors are U. S. mann graduate has received a Licénsed Transport Pilots and U. S. Licensed a . ‘ U. S. Govern- Mechanics. Our equipment is new and of modern i EL | design, subject to daily U. S. Government In- spections. (We have a resident Flying Course U.S.Government Inspector on the Easy Monthly Payments We teach you by actual fly- field—think what this means to UJ is easy to pay the Von Hoffmann way ing and practical instruction; because small monthly payments are extended. no long course needed. No you.) Let us show you how you can startnowand pay eudent bond required. later, even after you have finished the course Ground Course prt sa VON HOFFMANN AIRCRAFT SCHOOL 820 Lambert-St. Louis Flying Field (Lindbergh’s Own Field) St. Louis, Mo.

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é rs os = + es ar |Y ain * Ait KAP. "aia , hs tn 2G ae Follow the lead of the big industrial plants ... they use SIMONDS SAWS foe reasons why the big indus- trial plants use Simonds Saws are also the reasons why you should use Simonds Narrow Band Saws and Circular Saws in your own home workshop. Simonds Band Saws are noted for theamountof punishmenttheywill stand. Thespecially tempered alloy steel used in Simonds Saws gives them unusual toughness, strength and flexibility. And in regard to workmanship—Simonds Band Saws are as good as nearly a cen- tury’s experience can make them. A free booklet on woodcutting saws will be sent on request. Just write for it. siMg FILES 4 KNIVES ] STEEL SIMONDS SAW AND STEEL COMPANY FITCHBURG, MASS. “The Saw Makers” Established 1832 Branch Offices and Service Shops in Principal Cities POPULAR SCIENCE MONTHLY Aucust, 1929 How to Drain Your Ice Box Two Easy Ways to Install Piping That Does Away with the Nuisance of Emptying a Pan By Everett EAMES | FIG 1 | | REFRIGERATOR » F DRIP PIPE y 4 FUNNEL / / BELL OUT PIPE WIRE FASTENERS 1 ZO “ ai JOIST SSE SSS SSIS SHORT PIECE OF LEAD PIPE WITH HALF OF 2° BRASS UNION ye BRASS PIPE PLUG q : -" FLOOR a Diagram showing trap and piping beneath floor ready to be connected to the house drain. ANY refrigerators which use ice are allowed to drip into a pan in the old-fashioned way. Anyone who has tried to empty one of these brim- ful pans and has mopped up afterwards realizes that there is much to be desired in the arrangement. But when the ice box, like the Arkansas traveler’s leaky roof, is in use, you cannot fix it; and when it is not in use, it does not need fixing. Why not be a little forehanded and get rid of this nuisance by making a permanent pipe connection for the dis- posal of the drip water? There are two desirable methods of accomplishing this. One depends some- what on the foresight of the plumber who piped your home, and whether he has left an opening at one or more of the bends in the 2-in. pipe that carries away the water from the kitchen sink. This opening will be found closed with a brass plug. To connect the refrigerator with this outlet, first buy a new lead trap or obtain an old but renovated one from a plumber. A short piece of lead pipe with half of a 2-in. brass union on one end, and enough extra lead pipe to reach the overflow end of the trap, as shown in Fig. 1, also will be needed. The trap can be fastened to the floor by means of heavy wires. Its upper end Fig. 2. Sediment pan under floor with pipe which leads outside through the foundation. . 2). The pan is set at a slight angle and is should be belled out slightly with a ball peen hammer after it has been passed through a hole drilled for the purpose in the floor. The refrigerator drip pipe discharges through a funnel into the lead waste pipe, thus providing a flexible connection between the two. “ The other method is to pass a lead pipe through the floor and allow the water to drip into a rectangular copper pan (Fig. drained by a 1-in. lead pipe, which passes through a hole drilled through the rear wall of the house. Sometimes the water can be allowed to drip directly into a flower garden, or a watering can may be kept under the pipe. The object of using a pan is to provide a convenient method of catching the slime and waste particles released from the melting ice, which in time would clog the pipe. A trap of No. 30 brass or copper screen should be soldered across the inside CUT ON LINES-A 8 BEND ON LINES-8 G te) ' ‘ Fe: Sena ee SOLDER TRAP (30 COPPER SCREEN -!" HIGH CORNERS _) ¢ J ) aa ‘ Sew I" LEAD’ PIPE cur ar ance” \ + FIG.3 How the pan is made and provided with a screen to keep all the sediment from the pipe. of the pan just in front of the outlet, as shown in Fig. 3. The method of constructing the pan and making the joint between the pan and the pipe should be studied before the metal is cut. When placed as shown, the screen is not likely to be clogged, but even if it is, water can run over it into the compartment with the outlet. It will be noted, too, that the pipe is bent and sawed off at an angle before being soldered to the bottom of the pan. The reason a pan cannot be used in the first method is that any opening (except the roof vent) which is even remotely connected with a sewer, as in the case of a sink run-off, must be water-sealed, as by a trap. Any cleansing necessary can be accomplished by removing the plug at the bottom of the trap. _ @._ This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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» 1929

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Home Workshop Chemistry % Simple Formulas that y Will Save Time =<=- and Mon nvA tal

HE home workshop chemist can gage the moisture content of the atmos- phere with considerable accuracy by making a contrivance for which the essen- tial materials are a sheet of white filter paper and a small quantity of chloride of cobalt. Less than half a dram of the chemical dissolved in half an ounce of

GCASS IMPREGNATED PAPER

Using water colors to prepare a tinted scale for comparison with the impregnat- ed filter paper. The completed moisture- measuring instru- ment is at the right.

water (or as — as you can pile on a five-cent piece dissolved in two teaspoon- fuls of water) is sufficient for one sheet of filter paper. Pour the solution in a flat-bottomed developing tray; then fold the filter paper until it is small enough to fit the tray and place it on top of the liquid. The paper will quickly absorb the solution and will assume a beautiful rose color. After one minute or more, when the paper is evenly colored, remove it from the tray, unfold it, and let any excess solution drip back into the tray. Hang the wet paper over a horizontal glass rod, or pin it to a narrow strip of wood, leaving it thus in a warm place until it is dry, when the color will no longer be rose red but a rich and beauti- ful blue. It is this remarkable change of color which makes it possible to measure with considerable accuracy the moisture con- tent of the atmosphere. In dry air the paper will retain the vivid blue color, but the greater the percentage of moisture in the air, the more will the color of the paper change from pure blue to rose color. For ordinary purposes the observation of the tint of the paper will indicate with sufficient accuracy the percentage of moisture, but where greater accuracy is required, it is necessary to employ a more exact method. Provide yourself with a long strip of white, smooth draw-

ing paper, about (Continued on page 122)

POPULAR SCIENCE MONTHLY 107 “Whoa! .. easy

now, says the drill point. rane **YANKEE”’ Two-Speed Hand Drill No. 1435 Length, ll inches. 3-jaw chuck; 44-inch. Price, $4.50.

= do not want to burr the hole or snap your drill. The drill gives you warning: “Go easy, in drilling through.” With “Yankee”’ No. 1435, anew two- speed hand drill, you shift instantly to low gear and slow speed for easy drilling through. You avoid jamming. Saves drills! You make holes true, smooth, free of burrs. Saves time and bother! This drill, only 11 inches long, is the only small drill that gives you these speed cheages. Your dealer knows it as “Yankee”? No. 1435. Ask for it by name and number. Price, $4.50.

“Yankee’’ No. 250 Tap Wrench, with Ratchet adjustments and sliding cross-bar, makes awk- ward jobs easy. Price, $1.85. Ask for “Yankee”

**Yankee”’ No. 1530 Ratchet Hand Drill. Five adjustments, including “Yankee”? Double Ratchet for work in tight places where crank can be moved only to and fro. Length, 1014 inches. Weight, 114 lbs. Three-jaw chuck; 14-inch capacity. Price, $5.25. a Aa rs: P| YANKEE’ TOOLS MAKE BETTER MECHANICS NORTH BROS. MFG. CO., Philadelphia, U. 8. A. I want to know all about tools that save time and effort: You may send your book showing pictures of “‘ Yankee” Tools and the ingenious ways they work: Breast, Hand, Chain and Bench Drills, and Bit Braces, with “Yankee” Ratchet. Adjustable-Tension Push Drills, Vises, Etc.

© This seal on an advertisement in POPULAR SCHENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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108

IF YOU CAN USE AN ‘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 I0 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, beingunaffected by water, oil, gasoline or heat, is also excellent for auto- mobile repairs. Try it for stopping radiator, 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, tighten- ing 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. 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.

Doit with SMOOTHON

SMOOTH-ON MFG. CO., Dept. 58. 574 Communipaw Ave., Jersey City, N. J. Please send the free Smooth-On Repair Book. POPULAR SCIENCE MONTHLY Aucust, 1929

On the Hunt for Old Lights If You Can Lay Hands on a Good Looking Gas Lamp, Discard the Burner and Wire It for Electricity By Harovp P. Stranp an electric lamp, you will need the following materials, which can be purchased from any well-stocked electri- cal supply store: a two-light cluster and stem, two pull chain sockets, an attach- ment plug, silk parallel cord of the re- quired length, a -in. hard rubber bushing, and 2 ft. of bead chain. The necessary tools are a \%-in. pipe tap, 5¢-in. drill, tap wrench for holding the tap, pair of pliers, small screw driver, jackknife, gas pliers, and a bit stock. The step-by-step operations are shown in the drawings below. After lifting the shade from its support, unscrew the old gas burner (Fig. 1) by placing the pliers just beneath the adjust- ing wheel and turning to the left. Remove the gas cock and stem with the pliers; it may be that it is cemented in with a sealing compound or solder, in which case apply heat from a torch, taking care to keep.it away from any finished surface which may be marred. In this operation the lamp is usually turned upside down and the heat applied to the L-block into which the stem screws. Now screw the cluster and stem on the end of the pipe at the top of the stand (Fig. 2). With the 5¢-in. twist drill (rather than 3%-in. as in the drawing), ik CONVERT an old gas lamp into

Attractive electric table lamp made from an old and supposedly worthless gas burner. ream the hole through the base as in Fig. 3 to reach the vertical hole in the stand or upright. Place the tap in the tap wrench and carefully cut some threads in the hole (Fig. 4) to secure the bushing, which follows next. Drop the bead chain into the top of the lamp through the cluster and shake it down through the center of the lamp and out at the bottom. Then trim one end of the lamp cord bare with the knife and twist the strands together, both wires into one cable. Wrap this wire around the bead chain (Fig. 5), making the joint as small as possible and yet sufficiently strong. Pull the cord up through the lamp by means of the bead chain. A little difficulty may be expe- rienced in getting the joint to passthrough the bottom end, but by making a <areful twist it will go. Some the outer silk covering of the cord, if of a thick variety, may have to be removed. The connections to the sockets at the cluster are made by

BARE ENDS OF ELECTRIC CORD WIRES TWISTED TO END OF CHAIN

CLUSTER cutting the cord clean from the bead chain and splitting the outer silk covering with the knife for about 3 in. At a point 114 in. from the end of each wire, scrape a bare spot about ¥% in. long. Take two short pieces of wire, scrape the ends bare for 1 in., and wrap each one on the bare spots on the cord, tightening the joints with the fingers. Apply some flux and solder the joints. Wind them with {both rubber and friction tape, keeping them as small as possible (Fig. 6). The socket caps are now screwed on, the connections made to the contact screws, and the shells snapped in place. The other end of the cord is carried out through the bushing and the attach- ment plug connected to its end. The completed

Diagrams showing step by step how a two-light electric cluster and stem are substituted for the burner of an old table gas lamp.

lamp (except the shade) is shown in Fig. 7.

A A Oe nr pe

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1929 i ig. id ap ds Z, AucustT, 1929 | Blueprints for Your Home Workshop | 1 7 ~~ UR blueprints can be obtained: for 25 cents a sheet. In some cases there are two or three sheets to one subject. The blueprints are complete in themselves, but if you wish the corresponding back issue of the magazine in which the project was described in detail, it can be had for 25 cents additional so long as copies are available. Other subjects besides those below are to be had; send a stamped envelope for the complete list. Popular Science Monthly, 250 Fourth Avenue, New York Send me the blueprint, or blueprints, I have underlined below, for which I inclose........ VOR r ee eee CT ee eee Described No. Title in Issues of Price 15. Workshop Bench *Jan., °’23 25c 30. Tool Cabinet, etc. *Jan., ’24 25c 31. Sewing Cabinets Feb., ’24 25c 43. Four-Tube Receiver (battery operated) *July, °25 25c 44-45. Pirate Ship Model *Feb., °26 50c 46-47. Galleon Ship Model *May, ’26 50c 48. Yacht Model (20-in.) *July, ’26 25c 50. Airplane Model (rise-off- ground tractor, 36-in.) *Sept., °26 25c 51-52-53. Clipper Model, Sovereign of the Seas *Oct., ’26 75c 54. Five-Tube Radio Set *Oct., .’26 25c 55. Five-Tube Set—Details *Oct., ’26 25c¢ 56. Bird and Animal Toys Dec., ’26 25c 57-58-59. Constitution Ship Model (‘‘Old Ironsides’’)*Jan., ’27 75c 61-62. Viking Ship Model Apr., ’27 50c 63-64. Toy Motor Boat, 29 in. long hull May, ’27 50c 65. Six Simple Block Puzzles June, ’27 25c 66. Ship-Model Weather Vane Aug., ’27 25c 67. Toy Model of Lindbergh’s New York-to-ParisPlane Aug., ’27 25c 68. Magazine-Rack Table and Book-Trough Table 69. Flying Model (3-ft.) of Sept., °27 25c Lindbergh’s Monoplane *Oct., °27 25c 70-71. Console Radio Cabinet Nov., ’27 50c 72. Doll’s House *Dec., ’27 25c 73. Doll’s House Furniture *Dec., ’27 25c 74-75-76. Santa Maria Ship Model, 18 in. long hull *Dec., ’27 75c 77. Simple Pier Cabinet and Decorative Wall Shelves Jan., ’28 25c 78. Simple Treasure Chests Feb., ’28 25c 79. Electric Radio Set Feb., ’28 25c 80. High Power Unit for Elec- tric Radio Set Mar., ’28 25c 81. Low Power Unit for Elec- tric Radio Set *Apr., ’28 25c 82. Simple Single-Stick Air- plane Model (30-in.) Mar., ’28 25c 83-84-85. Mayflower Model Apr., ’28 75c 86. Racing Airplane Model (35-in. twin-pusher type) May, ’28 25c 87. Seaplane Model (30-in.) June, ’28 25c 88. Simple Modernistic Stand; Modernistic Bookcase Aug., ’28 25c 89-90. Bremen Scale Flying Model (3-ft.) Aug., ’28 50c 91. Modern Folding Screens Sept., ’28 25c 92. Simple Baltimore Clipper Ship Model (8 in. long) Sept., ’28 25c 93. Three Modern Lamps Gst., "RR 25c 94-95-96. Mississippi Steam- boat Model Nov., ’28 7s 97. Modern Electric Radio Set in One-Tube Form Nov., ’28 25c 93. Modern Electric Radio Set in Two-Tube Form Dec., ’28 25c 99. Modern Electric Radio Set in Four-Tube Form Jan., °’29 25c Modernistic Book Ends, Book Shelf, Low Stand Dec., ’28 25c 101. Toy Fire Engine, Sprin- | 100. kler, Truck, Tractor Dec., ’28 25c 102. Morris Seaplane Model (record flight, 1214 min.)Mar., ’29 25c 103. One-Tube Battery Radio Set (old No. 41 revised to Mar., ’29) 25c 104. Tractor Airplane Model (record, 6,024 ft.) May, ’29 25c 105. Tavern Table and Colo- é nial Mirror June, ’29 25c 106-107. Yacht Model (42-in.) June, ’29 50c *Magazine only out of print. Name. , , a AVEO eer (Please print name and address very clearly) Street... . City and State...... POPULAR SCIENCE MONTHLY We have Sent 3,000,000 men this free 7-day tube 86% of those who try it discard their old-style methods. Will you do us the kindness of send- ing the coupon for your test? It’s free. GENTLEMEN: Some time ago we asked 1,000 men to advise us in creating a new shaving preparation ~—Palmolive Shaving Cream. They told us @| Simportant ways old —! methods failed to please. After much experimenting we've finally succeeded—and millions of men have acclaimed the cream we make. If you had been one of the 1,000 men we asked, what would you have suggested? Please read this list and see if these are not the things you, too, have sought: 1: Multiplies itself in lather 250 times. 2: Softens the beard in one minute. 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. \Y PALMOLIVE RADIO HOUR~Broadcast every Wednesday night—from 9:30 to 10:30 p. m., eastern time; 8:30 to 9:30 p. m., central time; 7:30 to 8:30 p.m., mountain time; 6:30 to 7:30 p.m., Pacific Coast time—over station WEAF and 37 stations associated with The National Broadcasting Co. 4731 Our free test offer In order that men might know what our great laboratories had achieved we told them: “Don’t buy—yet.” For we wanted to prove to them, at our expense, the wonders of the shaving cream we'd made. And of the millions who have made our no-risk test, we find 86% stick to Palmolive Shaving Cream—reject cheir former methods for this new one. Probably you will find we have anticipated your desires in our unique new cream. So we ask you, in fairness to yourself—and to us who have tried to please you—to mail the coupon now. A generous 7-day test will come to you by return mail. Act now. To add the final-touch to shaving luxury, we have cre- ated Palmolive After Shaving Talc—especially for men. It does not show on the face. Try the sample we are sending free with the tube of Shaving Cream. '7 SHAVES FREE! 1 andacan ofPalmoliveAfter Shaving Talc Simply insert your name and address and mail to Palmolive, Dept. B-3089, 595 Fifth Avenue, New York City. In Canada, address Palmolive, Toronto, 8, Ont. 1 (Piease print your name and address) ——— wr we ew er ws ss es ses as Ss ssn eee

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110 POPULAR SCIENCE MONTHLY AuGustT, 1929 Improved Operation ~ (CHARACTERIZED by durability, ease of handling and improved operation, the Stanley Bit Brace No. 810 combines all the features that the expert tool user wants. Two sets of pawls give six- teen divisions in one revolu- tion of the pawl gear, prevent any back turning and make a very sensitive and easy op- erating ratchet. Ball bearing chuck holds round shank drills up to and including half inch, also Morse taper shank and square taper shank. All operative parts are practically indestructible. Your hardware dealer carries Stanley Bit Brace No. 810. Ask him for a copy of Stanley Tool Catalog 34e or send to us for a copy. The Stanley Rule and Level Plant, New Britain, Conn. STANLEY TOOLS The Choice of Most Carpenters i could be used. The Building Garden Woodwork advance of the simple trellises and fences described in the July issue, but they enhance a garden greatly and well repay the amateur woodworker for whatever effort he makes in designing and constructing them. The pergola illus- trated was built by Charles Thiel, of North Andover, Mass., a reader of PorpuLaR SCIENCE Monrtuty. Not only did he work out an unusually attractive design for the upper part of the pergola, but he arranged the latticework in a pattern to spell his name, as a close inspection of the photograph will re- veal. This was such a novel idea that it attracted much at- tention in his neigh- borhood and _ has been copied by other craftsmen. Another type of substantial arbor—one’ with two seats and a garden gate—which has been built with much success by readers is shown completely in PopuLar ScrenceE Montuty Blueprint No. 9, which can be obtained for twenty-five cents (see the list on page 109). Besides the usual assembly views and a complete bill of materials, this blueprint contains ice and pergolas are a step in Toy Foot-Propelled Auto for Small Child REQUENTLY it happens a little fellow of from two to four or five years old wants an auto “just like Daddy’s” when he is too small for factory-built, foot-pedal-driven models. Then, too, these models are expensive for UPRIG! BOARD Pa Working drawings of the toy auto, the original model of which was constructed in the Mishawaka (Ind.)High School shops. The steering wheel is turned from 1-in. stock, but a ready-made substitute car is painted brightly. Pergola constructed by Charles Thiel in such a way that the latticework spells his name. a full size pattern of one half the top curve and other full size details, making it very easy to work from. Designs and bills of materials for sev- eral trellises of a more elaborate type than those illustrated last month are con- tained in Blueprint No. 34. On this sheet is also an in- teresting sundial support built of wood in trellis fash- ion. Indeed, this sheet is so filled with helpful sugges- tions that anyone planning to build trellises will find it an aid in deciding the best arrange- ment for his own particular purposes. An especially graceful wooden porch swing is com- pletely detailed in Blueprint No. 10 and is a good pro- ject where oak, ash, or other hardwood can be obtained at a reasonable price. Another piece of attractive and easily made furniture for the porch, garden, or breakfast room is the bench and tilt-top table of Blueprint No. 11. Normally the piece is used as a bench and has a roomy compartment for storage under the seat. When a table is desired, the back is tilted forward and forms a rectangular top 2 ft. 6 in. by 4 ft. 6 in. A colorful homemade car for a boy not big enough to operate a pedal-driven machine. many pocketbooks. Both considerations had some bearing on the design and building of the car illustrated. Any kind of wood that does not split easily will do for the wooden parts. The axles, kingbolt, and tie-rod are made of mild steel. The wheels may be pur- chased from a manual training supply house or taken from an old wagon or other toy, if one is available. To connect the steering wheel with the axle, a heavy cord will do, but a piece of -in. stranded steel cable will be better and last longer. Notice that the cords cross under the car.—H. R. Goprpert and E. SPRAGUE. | @® This seal on an advertisement in POPULAR SCIENCE MONTHI ™ signifies the approval of the INSTITUTE OF STANDARDS. See page 8. NS EO ETT A oe

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[929 \y ‘

ee 2k oe 2

Anon e oN

AucustT, 1929

Motor Wheel Drives Boy’s Coaster

In spite of rough pavements and heavy loads, this little auto has given excellent service. LLOWING the publication of an article on making a homemade coaster in the July issue of last year, many in- quiries were received asking how power could be applied to the little car. The most practical plan is the use of a standard motor wheel such as are manu- factured for attaching to a bicycle. This has the advantage of being a compact, self-contained unit, relieving the coaster of any additional weight. The only alteration required in fitting the wheel to the coaster as originally illus- trated last July is the removal of the dummy gas tank. The coupling for the two units is merely a block of clear yellow pine or oak sawed to fit the front end of the motor wheel, with a vertical bolt up through the forward end. A horizontal bolt secures the motor wheel to the fork at the rear end of the wooden block. The fork should be just wide enough to take the front motor support with washers on each side. This is important, for if there is any side play the motor wheel will tend to wobble when in motion. After removing the dummy gas tank, nail or screw a wooden crosspiece or cleat 1 by 3 in. by the width of the body over the rear axle (on top of the main body board) and a similar piece on the end of the board (see A and B). Then bore a %- in. hole through the axle block to receive the bolt. A rear seat fastened to the coupling block will not interfere with operation and there is plenty of power to carry an extra passenger. A “‘mechanic”’ is handy, too, for a motor of this type must be pushed to get started, and it is awkward for the pilot to do this. The car can be stopped within a few feet in an emergency.—H. S.

Ye x72 CARRIAGE BOLT PASSENGER SEAT

COASTER WHEEL

“2—— FORK FOR MOTOR ARM OUPLING BLOCK

How the motor wheel is attached to the coaster. The control wires are carr'ed to a convenient

block extending from the right side of the car. ‘ a NN \ (eg POPULAR SCIENCE MONTHLY Will you risk 2¢ for a *200 return?

Pledge to the Public on Used Car Sales { Every used car is conspicuously marked with its lowest price im plain figures, and that price, just as the price of our new cars, is rigidly maintained. 2 All Studebaker automobiles which are sold as CERTIFIED CARS have been properly reconditioned, and carry a 30-day guarantee for replacement of defective parts and free sérvice on ad- justments. Every purchaser of a used car may drive it for five days, and then, if not satisfied for any reason, turn it back and apply the money paid as a credit on the purchase of any other car in stock—new or used. (It is assumed that the car has not been damaged in the meantime.) —— © 1928 The Studebaker Corporation of America =<gse\ 130,000 people

THE STUDEBAKER CORPORATION OF AMERICA | Dept. 168, South Bend, Indiana | Please send me my copy of your valuable free booklet, “How to Judge a Used Car.” | | | NN a cae anecnned OS Sn lll a you willing to gamble a 2c stamp on the chance thatthis free booklet, “How to Judge a Used Car”, will do for you what it has done for thousands of others— that it may save you $200 on the used car you buy? See if the answers to these questionsare worth 2cto you: What do code prices mean? Howcan [avoid “orphans”? What is a fair price to set on aused car offered bya friend? What is the model year of a given used car? What does the speedometer tell? The answers to these questions and a host of others are in the 32 interesting pages of text and picture you get for a 2c stamp when you send for your free copy of “How to Judge a Used Car”. Will you take a chance on your own judgment when you buy your used car—or will you have the benefit of the information that car ex- pertshaveaccumulated dur- ing years of buying experi- ence? Fill in and mail the coupon below —let a 2c stamp insure you of used car service and satisfaction! have saved money * by mailing this coupon!

Builder of Champions — =

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112 Champion Spark Plugs exeel and outsell throughout the world It is a fact that Champion Spark Plugs keep the vast majority of the motor cars of the world running. In the realm of business few indeed are the American products which enjoy the proud privilege of outselling all others throughout the world. No matter what the business, or prod- uct, you may rest assured that if it has roerited a universal preference, it is because it has deserved it; because it is a better product. There is a very real significance in the fact that Champion Spark Plugs out- sell throughout the world. A signifi- cance that is part and parcel of a never varying formula which directly con- cerns the material, design, manufac- ture and ultimate performance of Champion Spark Plugs. For the unity of purpose which dominates Champion has always been expressed in an uncom- promising search for better material, better design, better manufacture and better ultimate performance. You can buy Champion Spark Plugs with every assurance of superior per- formance and dependability. They will exact from your engine the utmost in power, speed, acceleration and economy because they are the better spark plugs. CHAMPION Spark Plugs TOLEDO, OHIO WINDSOR, ONT. POPULAR SCIENCE MONTHLY Aucust, 1929

How to Make It Is Ornamented in Every hunter likes to keep his shotguns and rifles in a dust- proof cabinet where they are well displayed and always accessible. | a Gun Cabinet Hunter’s Fashion and Has Space for Displaying Four Firearms By R. L. ReEapy Manual Arts Instructor, Batavia ( Ill.) High School pride in their firearms and like to display them to their friends. This can be done most conveniently if a gun cabinet is constructed such as the one illustrated. i While this cabinet requires careful | dein invariably take great

a ed w Ny TIN NZ I

LA Ai: - bee work to build neatly, it is so ornamental and serviceable when completed that no hunter should begrudge the time neces- sary or the relatively small cost for ma- terials. The experienced woodworker will find the drawings self-explanatory, but the following list of suggested operations may be helpful to the beginner: 1. Prepare the side or- naments, sawing the out- line of the rabbits, carving the recesses, cutting the mortises as shown, and planning for the side pan- els and the back panel. 2. Make two bottom side rails and plow one edge of each for panels. 3. Make four side stiles with tenons at the top end to enter the mortises in

<ZZA_\_] =p

ZZ

the side ornaments and mortises in the inner edges near the bottom to re- ceive the tenons of the bottom side rails. Plow the pieces for the side and back panels.

4. Assemble the sides.

= SIDE METHOD OF FORMING DESIGN ON CENTER RAIL

Front and side views of the cabinet with the dimensions followed by Mr. Ready, and explanatory details drawn to a larger scale.

5. Plow the side units for the top and bottom shelves. 6. Cut the back panel (Continued on page 113)

|

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AucustT, 1929 Making a Gun Cabinet (Continued from page 112) By first drawing a series of 1-in. squares, you can easily enlarge these parts to full size. and carve the rabbit design as shown above. 7. Assemble the case, taking care that it is perfectly square and true. 8. Make door frame, as shown, with the bottom, middle, and top rails mortised into the side rails. The center rail is made of a solid piece 34 by 8 by 15 in. Half the thickness of all of this piece, except that which forms the equivalent of a 2 in. wide rail, is cut away with the dado cutter or by hand; then the outline of the duck is sawed and carved as indicated. 9. Construct the drawer as indicated. 10. Make gun-butt holder as shown and gouge it out to fit the gun butts. 11. Insert the glass. The molding used is common screen molding ripped through the center. 12. Finish as desired. If made of oak, one coat of old English stain and two coats of flat varnish will give an attractive and durable finish. The Materials Needed No. Pcs. T. 7 L. Parts 4 % 1% 60 Side stiles 3 % 10 1744 Shelves (dadoed 3¢ in. into sides) 2% 1% 9 Bottom side rails (tenoned 1 in. into side stiles) 544 10 Side ornaments 1% 48 Door stiles 1% 15 Top and bottom door rails (tenoned 34 % 2 \eo\eo\\co POP in.) 1% 8 15 Center rail (tenoned 34 in.) 2% 174% Drawer front 2% 6 8 Drawer sides 1% 6 15144 Drawer back 1% 8% 16 Three-ply drawer bottom 2 4% ##.+1T% 55% Three-ply side panels 1% 17 63 Three-ply back panel 1 3% 8% 16% Gun-butt holder All dimensions are given in inches. Knotty Lumber for Boxes HAT knotty lumber will make a box with short, thick sides more resistant to rough handling than clear lumber, has been learned through experiments at the Forest Products Laboratory of the U. S. Forest Service. The size of any one knot in a board used for this purpose should not exceed one third the width of the board, and the aggregate diameter of all the knots within a length equal to the width of a board should not exceed the diameter of the largest knot allowable. Added to the other advantages of using knotty lumber in boxes is the lower cost of such lumber as compared to clear lumber. POPULAR SCIENCE MONTHLY 113 JOHN HENRY MEARS tells Jess Hrovuy. Joun Henry Mears, who holds the round-the-world record of 23 days, 15 hours, 18 minutes, shows Jim Henry, Mennen salesman, the route of his new globe- circling dash, Mr. Mears will travel by air, land and sea... “I'm racing around the world and MENNEN rides with me” Au ROUND-THE-WORLD is some test for a shaving cream. On a ship today—on land tomorrow—high in a speed plane over desert waste, sea or mountains. Different water, different weather, every time I shave! That’s why I’m taking Mennen Shav- ing Cream with me. I’ve experi- mented, and I know that Mennen gives me the same smooth shave everywhere—with any water in any weather...” Mennen Shaving Cream meets every shaving test to which men put it. Its scientific principle is Dermu- tation—an exclusive Mennen process which softens the beard, lubricates the blade, and tones the skin. Now! Two Tyres oF MENNEN— with or without Menthol Mennen Shaving Cream in the good old green-striped carton is the familiar favorite of millions of men. Now there is another Mennen cream—Mennen Menthol-iced with the triple-cool tingling lather. It is distinctly the young man’s shave. Menthol-iced comes in a gay orange-striped carton. Your druggist has both Mennen creams. Take your choice. SpectaL AFTER-SHAVE offer! A special traveler’s size of Mennen Taicum for Men is given free right now at your drug store when you buy a tube of Mennen Skin Balm. These two Mennen preparations are masculine delights. See your druggist today. Ask for the Mennen Arrer-Suave special. MENNASH FOR THE MODERN SHAVE —2 kinds of Mennen Shaving Cream Menthol-iced in the orange-striped carton. Without menthol in the green-striped carton, Mennen Skin Balm—the cooling cream-like lotion inatube. Non-greasy. 7 » ae * A “og Mennen Talcum for Men f , —the natural-tint man’s * powder that does not show. FOR THE SHAVE Send for a trial tube of Mennen Shaving Cream and Skin Balm. Just write name Free 14 Smooth Shaves! and address in the margin below and send it to Mennen Co., Newark, N.T. Dept. P-4

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114 To iaopeove your Game weara PAL ATHLETIC SUPPORTER Pal Let your mind and body both be free -+. unconstrained. Wear an athletic supporter. Nature left a crucial zone unguarded. Even when you forget the danger, your body remembers. PAL is far superior to the ordinary all- elastic supporter. It is porous... knit of soft-covered elastic threads. A more é- ficient supporter ... snug where it should be .. . comfortable all over. PAL doesn’t get perspiration-stiff . . . doesn’t chafe. At all drug stores ... one dollar. (Price slightly higher in Canada.) Bauer & Black A Division of the Kendall Co. CHICAGO... NEW YORK... TORONTO Also makers of the famous O=P=C For 40 years the leading suspensory for daily wear | atch it work! Once watch this machine in ac- tion and you will ‘‘swear off’’ on hand sanding for all time. Weighs only 13 pounds and works any- where a lamp cord will reach. The only portable belt sander is the TAKE; Sander Gives smooth ripple- less finish because of belt action, and is five times faster than hand sand- ing. Sands flat or curved ——— oe ~y a ne. Quickly pays for Feclf. wo sizes. Ask for information or free demonstration. The PORTER-CABLE MACHINE CO. 2000 Salina St. Syracuse, N. Y. POPULAR SCIENCE MONTHLY Aucust, 1929 t By W. A. DEVETTE HE trellis illustrated was designed for plants which ordinarily are allowed to droop over the edge of the pot or are placed in hanging baskets. The delicate framework with its graceful curved top makes it possible to train the plant to grow upwards and gives a better appear- ance when the pot is placed on a window sill or anywhere below the eye level.: The entire trellis can be made from Yj-in. wood, preferably poplar. All the parts are 4 in. square with the excep- tion of the seven top members, which are cut from pieces 4 by 1 by 6 in. and are spaced 14 in. apart. The four up- rights, which are 94 in. long, are placed in pairs 414 in. apart. The two long crosspieces are 15 in.; they are spaced 3 in. apart and the lower one is placed 34 in. from the bottom of the uprights. The two supports for the curved top members are 5 in. long; the four braces are 24 in. The twenty-three pickets, which are spaced % in. apart— eight at each end and seven on the “‘gate”—are cut as follows: three 434 in. long, four 5% in., four 5% in., four 51% in., two 6 in., two 65% in., two 6% in., and two 615% in. The trellis may be painted or finished with white brushing lacquer. This article represents in condensed form an entry which won third prize in the elementary woodworking division of a national contest for teachers of OME mechanics re- gard a discarded file as useless junk, yet old files often can be revamped into useful tools with but little grinding or forging. Round files may be made into pin and center punches, scribers, prick punches, reamers, and chisels. The | file teeth on the grip portion of the tools, when smoothed slightly on the grinding wheel, give the ef- fect of a knurled finish and aid one in holding the tool. Square and tri- angular files make glass drills, dia- mond-point chisels, bearing scrapers, small lathe threading and boring tools, and square-hole broaches. Half-rounds are chiefly used as bearing scrapers; the teeth are ground off the entire length, the in- side slightly hollow ground, and the edges honed with an oilstone to a smooth, sharp- cutting surface. Lathe tools made from flat files give excellent service, especially in threading and cutting-off operations, for they permit Discarded files provided the steel for these chisels, punches, scrapers, and other tools. Tiny Trellis Built for Flower Pot 7 — 44 inch squares Curved top dk: mt Flower-pot trellis designed for climbing plants, and a detail showing shape of the arched top. oY shopwork conducted by the Education- al Department of POPULAR SCIENCE MONTHLY. Mr. DeVette teaches in the Wilson Junior High School, Erie, Pa. Twenty-One Tools Made from Outworn Files By R. M. Kocu working in close corners. Wood chisels of all sizes can be made from flat mill files; and when the temper is drawn slightly, they hold up well in actual use. Considerable grinding is required, however, if it is desired to taper the blade very much, but this is not abso- lutely necessary, although it im- proves the appear- ance of the tool a good deal. Auger bit files can be made into small screw drivers for radio and elec- trical apparatus. Cut the file in half, put a small handle on each piece, grind the blades smooth, then draw the temper to a light blue to avoid breaking. The accompanying illustration shows some tools made from files at odd times with the aid of a grinding wheel only. The tools and the kind of file used in making each of them are as follows: 1. Glass drili made from 8-in. triangular saw file. 2. Lathe cutting-off tool, 12-in. flat mill file. (Continued on page 115) © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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1929 Aueust, 1929 POPULAR SCIENCE MONTHLY 115 “4 . x ar © F A Shake-and-Guess Game for Children y | | sn Sets eorron = f 3 ~~ one 0 Ree oe FINGERS 3 ( " ‘\iy Ss AN SOLDER Wy Y wiReE ENDS AWW ROOTS BAKING POWDER CAN 24x 3%" LADY FINGERS NUMBERED ee .AND CUT LONG End and side views of the game and details showing how the ‘“‘lady fingers’’ are fastened. “TADY FINGERS” is an_ entertaining guessing game for children. It also will | serve as a novel substitute for a dice shaker or a spinner in other games of chance. A baking powder can and six round sticks of wood 3¢ in. in diameter and 334 in. long are required. The fan-shaped hole in the center can be cut over a block of wood with a small chisel. The wire “roots” that hold the fingers can be a Sue single ag 4 of oy a0 ewe AWAY on your swift Harley- i even fine copper wire. ey are fas- ° : ° f paca the fingers Nit small nails; and the Davidson! Race with the wind—whir 1 twisted togeth hed th h loose ends are twisted together, pushed throug : : sisein the bottom ofthe can, and soldered t over hills — flash a the straightaways - the tin as shown. a é The one whose turn it oe holds the free as afl eagle! e ith the cover down and shakes it around. . Then ie calls out any ve from ane to six All roads beckon to sae Jump into the d brings the can to the horizontal position, : it; m with the slot at the bottom, as indicated, so saddle and See America! Cities, moun = that the fingers fall into the slot. If the called tains, lakes, seashores — just choose your ° figure rests on top, he is considered a good 3 - d G O guesser; if it age “1 top sane he is route for a glorious vacation an be llowed another chance; if his number is at S the bottom, he is a very poor guesser and is THERE! F orget the cost — the upkeep a eps Re gume—sreeeen Ww. Cham. of a Harley-Davidson is only a cent or two ; Tools from Outworn Files per mile. » (Continued from page 114) e 3. Sheet metal reamer, 14-in. square bastard See your local dealer today — look over , file. the Big Twin shown above, and our won- a 4. — belt punch, 8-in. round bastard d f 1 kage T a a ont $290 f . . fin q file. erru. wl . oo. Bs ‘ 5. Small screw driver, auger bit file. d Si 1 y $235 d $255 ‘ 6. Oil groove ones, SOS round file. ‘ tory » and our Ing es at an P 7. Diamond-point chisel, 12-in. square file. - ss . Ss . 8. Drift punch, 14-in. round fle. Ask about his Pay-As-You-Ride Plan. 9. Pocket scriber, 4-in. file. , ‘ ih Intch punch, ote. sone i. - Mail the Coupon for literature ) 11. Heavy center punch, 14-in. roun e. , ° Og ped agen agmatine that illustrates our complete line. 13. 14-in. pin punch, 12-in. round file. 14. 3-in. flat chisel, 12-in. round file. e 15. 5%-in. flat chisel, 14-in. round file. 16. Belt knife and gasket cutter, 6-in. knife a section file. ; 17. 1-in. wood chisel, 14-in. flat mill file. 18. Tinner’s scraper, 8-in. flat mill file. HAR pa 19. Bearing scraper, 6-in. half-round file. LEY 20. Bearing scraper, 10-in. triangular mill file. | “" Bearing scraper, 14-in. half-round file. 7 xeep the file cool when grinding to avoid ° ° Rog ae ee ae Rae ee cera ERE ka eee ruining the temper. Mail this HARLEY-DAVIDSON MOTOR CO. To cut off a portion of a file, grind a groove Coupon Dept. PS, Milwaukee, Wis. — Date........ccoooss+« — completely around it at the desired point, . Interested in your motorcycles. Send literature. clamp it in a vise, and strike the projecting end sharply with a hammer. To anneal a file, heat it to a cherry red and keep it covered with lime until cool. Touching up the handles-and grips of your tools with paint improves them. = = . yp Ore are Name Address My age is [] 12-15 years [] 16-19 years [ 20-30 years [] 31 years and up. Check Your Age Group,

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116 POPULAR SCIENCE MONTHLY Aucust, 1929 The bending of star shapes or other intricate forms can be done accurately around nails driven into a board. ca e Puzzles How to Develop Original Combinations to Mystify Your Friends—Two Simple Principles Give the Key OU can devise many fascinating wire puzzles if you are familiar with the two simple principles presented here. Bus bar or copper antenna wire may be used. All joints are best if soldered neatly, but the work itself is not difficult. In Fig. 1 we have two rings hinged to- gether, A and B. On one of them hangs another ring C, and over this is the somewhat smaller ring D. The solution is so simple that it can scarcely be called a puzzle. A and B are folded together as in Fig. 2. Ring C with D will slide down to the joint, permitting D to be lifted off as shown. If for A we substitute a star as in Fig. 3, the solution is not so apparent, since D must be worked around through the points of the star. Ring B in this case should not be too large; its circum- ference should cut, the points of the star in half. D should be just large enough to slip over the points. For C in Fig. 1 we may substitute a triangle, star, or other form. Another principle is illustrated in Fig. 4. On the U-shaped wire (in the upper of the two dia- grams) are hung rings B and C. Between them is the smaller ring D, which may be removed as shown in the lower diagram. By combining this principle with that of Fig. 1, we can make By ARTHUR L. SMITH a confusing puzzle. For A and B, Fig. 1, we substitute two stars as in Fig. 5. On the points of these are hung the four rings C’, C', C?, and C*, two on each star. On one of these, C, for instance, is placed the ring D. To remove it, the C ring holding it is worked around to the joint. The stars are folded together, and D may be removed by working it around through the points and the other C rings on the principle shown in Fig. 4. Another D ring may be put over either C? or C’, and it is possible to remove both D’s. To make this puzzle it is best to lay out a star on a board as in Fig. 6. Two circles are described from the same center, one within the other. The angular degree and the length of the points will depend upon the difference in their diameters. For a six-pointed star A few of the many puzzles which can be made by utilizing the two solutions shown in Fig. 2 and in the lower view of Fig. 4. the radius of the circle will give the distance between the points. Nails are driven into the board at the points of all angles as shown. The heads must be cut off so that the nails do not project more than \% in. above the sur- face. The wire then may be bent accurately around the nails. Figure 7 shows another varia- tion of these two principles. A and B of Fig. 1 are elongated to U shapes so that D may slip over them. On the ends of these must be hung devices to prevent the removal of D. The illustration shows a ring C, over which is placed D. At the other end is another ring £E, attached as shown. To remove D, the U’s are folded and ring C is moved around to the joint, which permits D to be brought around to the bend of U and worked through £ on the principle of Fig. 4. Ring C may be attached in the same manner as E, if desired.

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1929 es nd rd. the and out cles one ree ond 1eir tar ive its. ard as ect ur- ent ria- to ver ust the ion is as are ind to of the ay 1er AucustT, 1929 This Model Flies Up (Continued from page 81) RIGHT-HANC PROPELLER , LEFT-HAND PROPELLER Fig. 3. How to mount the revolving propeller (upper view); the completed model (lower). the other blade to the opposite side. Be sure that these blades in both cases are ar- ranged so that the rounded side of the camber will be up. It is suggested that you fasten the blades 134 in. down from the body so that they will be braced by the small body crosspieces. These propellers should be as light and feathery as it is possible to make them. They can be brought down in weight and thickness by a generous use of coarse and fine grades of sandpaper. Use No. 2 at first and finish off with No. 0000. You will find it necessary to install the propeller shaft in the revolving propeller by slipping it through the underside of the top piece, placing two washers and the propeller on it, and then fastening it to the propeller. A long shaft will be found helpful in counter- acting any wobbling effect, in which case No. 6 (.016 in.) music wire is a suitable size. Two strands of % by )% in. flat rubber are satisfactory for this machine. Unhook the S-hook and wind the motor as for an airplane model; then replace the S-hook with pliers or tweezers. — ee es se, TWO-BLADE PROPELLEF 6 PIECES 52" ie'x % a 2 PIECES | — \/52 x78 X7 i RUBBER HOOK NO.6 MUSIC WIRE GOLDBEATER’S SKIN, OR JAPANESE TISSUE " ti; gg “2 SQUARE BAMBOO “I 2 DROPS OF CEMENT TO CENTER S-HOOK Fig. 4. Design for a Penaud model like that given the Wright brothers by their father. POPULAR SCIENCE MONTHLY ow Your Morning Shave Can Last Longer You can stay clean-shaven all day because of closer shaving made possible by small-bubble lather. __— is a satisfaction when, in the evening, you realize that your morning shave is lasting. This six o’clock satisfaction means you’ve had a really close shave in the morning. That means a properly moistened beard, and Colgate’s guarantees that. Small bubbles— that’s the Colgate secret of such efficiency. Small bub- bles get down to the base of the beard and moisten it more thoroughly than big, air-filled bubbles. Two vital facts—easily proved The minute you lather up with Colgate’s, two things happen: 1. The soap in the lather breaks up the oil film that covers each hair. 2. Billions of tiny, moisture- laden bubbles — down through your beard... crowd around each whisker... soak it soft with water. Instantly your beard gets moist .... easier to cut and = .... scientifically softened — down at the ase .... then your razor can do its best work. Better grooming—the utmost in shaving comfort. A world of critical men, after various experiments with big-bubble lathers, have found that Colgate’s is supreme. You, too, will agree. Let us help you in de- ciding—note our offer below. 117 ORDINARY LATHER Ordinary, big-bubble lather (greatly mag- nified). Note air-filled bubbles which can’t soften the beard effi- ciently. Only water can do the job. Only small bubbles permit sufficient water. COLGATE LATHER Colgate’s lather (grea ly magnified) showing moisture contact with beard and minimum air. A common-sense principle scientifically authenticated and proved out practically by millions of men. of “After-Shave.” COLGATE, Dept. B- 1771 595 Fifth Ave., New York. In Canada address Colgate, Toronto, 8 Ontario. Please send me FREE, the seven-day trial tube of Colgate’s Rapid Shave Cream; also a sample bottle

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118 POPULAR SCIENCE MONTHLY Aucust, 1929 Now—A REPEATER 20 Shots at One Loading! WE manufacturers of the highest powered pneumatic rifle in the world now announce another great achieve- ment—THE CROSMAN PNEUMATIC .22 RE- PEATER with 20 shots at one loading—the ONLY high-powered re- peating pneumatic rifle in the world. A real re- peater for target and small game-shooting such as every gun en- thusiast has impatiently awaited—and now can have at the surprisingly low price of *15 This new Crosman Re- peater has all the fea- tures of the famous Crosman Single-Shot— no noise, amazing ac- curacy, no cleaning, low cost ammunition, and power to kill small game —PLUS 1 Twenty shots at * one loading. 2 Greatly increased * adjustable power. 3 Checkered w al- * nut stock and forearm. 4 Improved . * sights (peep WHY or open sight it is called a optional). Pneumatic : The high- Exclusive owered * pyrasteel SMAN valve, giving is called fa life-time serv- TIC a oS ice. todistin- fu ish it rom toy air ies. Get a Crosman Repeaterat your dealer’ s. i he has not yet been supplied, mail us $15 a his name—if west of the Rockies. $16—and we will send you one prepaid. Or mail us $5 and pay your postman the balance on delivery. CROSMAN ARMS CO. ge St. Paul St., . N.Y. IRN, Pneumatic .22 REPEATER "POWER WITHOUT POWDER’ Novel Saw Rack Saves Waste Motions A rack which holds saws in a position to be picked up without a moment’s loss of time. As AN improvement over hanging up my saws on nails, I built the rack illustrated, which allows the saws to be grasped instantly in the proper position for use. The rack can be made of 1 by 2 by 12 in. or heavier pieces spaced 3¢ in. apart and screwed to a 2 by 4 of the required length.—Grorce W. Royer. When Doors Need Paint (Continued from page 90) with turpentine, but a little good floor or spar varnish should be added to knit the new paint to the old varnish firmly and to avoid cracking later. A good pro- portion of varnish to turpentine is about one third varnish and two thirds tur- pentine for this coat, although as little as one fourth varnish will serve the pur- pose. For applying the paint you should have a flat brush of good quality with long bristles — one about 2 or 2% in. wide. You will need also a round or flat l-in. brush if there are lights of glass in the door. It is necessary to remove the door from its hinges to paint the bottom and the top edges. It is very impor- tant to paint these edges to prevent warping. First paint A, next B, then C, and so on, The Materials Needed for Two Coats a. Ready-mixed outside oil paint, 1 pt., or b. White lead paint requiring: 1 pt. boiled linseed oil 1 pt. turpentine 5 lbs. white lead, regular grind 1 Ib. tinting color to suit Note: The formula for white lead paint is based on the use of a 5-lb. can and will make a little more than 1 qt. of paint, or enough for two doors. After painting them, place the door on its hinges again and paint the parts in the order shown above. The door knob and escutcheon plates should be removed before painting. If the hinges are solid brass it is usual to keep them free from paint, but if they are plated it is customary to paint them. Fishermen’s Knots (Continued from page 102) as reliable as the slightly more complicated compound loop knot. In tying the compound loop, first form an ordinary slip or running knot (Fig. 1). Then loop the free end about, passing it over the two portions of the large loop and under the re- maining parts of the line as shown in Fig. 2. Finally draw the knot tight, and you have a loop that will not slip or break easily. For the sake of clarity, a cord much larger than any- thing you are likely to encounter in fishing was used in making the illustrations. Perhaps you wonder why the compound knot is recommended rather than the familiar bow- line, which is easier to tie and which, at first glance, looks as if it would do just as well. After much experimenting, fishing experts have found that the bowline will break sooner than the compound because the line is bent more sharply in forming the knot. For that reason, the latter knot has been adopted as standard on manufactured tackle, and has preved its superiority during years of use. If you do even the simplest fishing, you will encounter the difficulty of joining two pieces of gut leader together. When you use an or- dinary knot, the chances are that the splice will part just when it should hold. So it will repay you to tie the twist knot (Fig. 6), considered by many anglers as the best for such purposes. In tying it, first twist the two ends about each other, giving each two turns as shown in Fig. 4. Then pass the ends through the central opening between the twisted lines in opposite directions (Fig. 5) and pull the knot taut. To attach the fishing line to the loop of a snell or leader in such a way that you can untie it quickly, there is nothing better than the helm knot or tiller hitch. It is easy to tie, as shown in Fig. 7. Other knots which the fisherman can use include the single and double buffer, the com- mon leader, and the reef or square knot. However, the three knots illustrated will be found superior in most instances. These knots are by no means confined to fishing activities. They are useful for joining all kinds of ropes and lines. Knowledge of how to use knots has saved many a life. Old Photographic Films Make Good Stencils Stencil cut from an old negative with a razor blade. It bends without cracking. ya regular stencil paper is not avail- able, an old photographic film is a prac- tical material for making any simple stencil which does not require too careful and elabo- rate design and craftsmanship. Such a stencil is easy to keep clean.—F. W. Bent ey, Jr.

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ted hen two ea the ny- ‘ing not OW- irst ell. arts ner ent hat as has ise. will or- will pay red ses. out 1 in tral site f a atie the , as use »m- 10t. to ing . of rail- rac- ncil ibo- ncil Avucust, 1929 POPULAR SCIENCE MONTHLY 119 Reproducing an Old Chair (Continued from page 104) List of Materials Parts No. Dia. Length | Legs—back 2 134 3814 | front 2 1% 16 | Rounds—front 2 1 1844 | side 4 1 1214 | back 1 1 12% | seat 1 34 124% | seat 1 34 18% | seat 2 34 13 Slats, bowed 4 S¢by2loby | 13 long. Fiber or rush sufficient for one seat. The stock is maple. All dimensions are in inches. the middle. These are usually worked out by hand. Only one round is to be placed under the seat and between the back posts; this is on the same level as the bottom one on the front side. Asa matter of fact, I could find no sign of a rear round on the old chair, but for additional strength it seems advisable to include one. The slats are only 5¢ in. thick. As they are bowed slightly, each piecé can be steamed or soaked in boiling water and then clamped to aform. Another way is to shape each slat, from a piece of stock 1 in. thick with the aid of a spokeshave. At the present time many old chairs of this type are being refinished in modern ways. Some are even painted jet black with touches of gilt or bronze paint; others are given a dark brown or chocolate color. For an antique maple finish, a very light walnut stain may be used and wiped or sandpapered off in places to give a high-lighted effect. If it is not possible to obtain rush or fiber locally, send a self-addressed stamped envelope to the Information Department of POPULAR SCIENCE MONTHLY for the names of dealers. Homemade Gluepot Keeps Hot a Long Time YVREN a large quantity of hot glue is to be used and a gluepot of suitable capacity is not available, an excellent and inexpensive substitute can be made as shown from a 6- or 8-qt. galvanized pail, a 5-lb. syrup bucket or similar container, and a sheet of heavy tin. CUT OUT FOR BRUSH HANDLE KL IN COVER FOR GLUEPOT S SSw TIN BUCKET BUCKET COVER Glue remains fluid in this pot for con- siderable time when once the water is hot. The large quantity of water which this gluepot holds is an advantage because with one heating on the kitchen range or gas stove the glue will remain in a fluid state for a considerable time. Do not omit the cover for the small bucket because keeping the glue covered when not actually being used will prevent a “skin”’ from forming.—R. C. STANLEY. ATKINS "SAWS je . ’ hate — * , \ cs \ | bay your home workshop, use the new ATKINS Hack Saw Blades which have revolutionized metal-cutting in thousands of factories, shops and mills all over the world. They cut TWICE as fast and last SIX times as long as ordinary blades. Just try one on your next metal-cutting job! For every kind of wood or metal cutting, there are ATKINS Saws, to do the work faster, easier and better—‘‘A Perfect Saw for Every Purpose.’ Hand Saws,—**400"’ and ‘‘401,’’—and other favorites for cross- cutting and ripping. Back Saws to do fine work in Cutting mitres, grooves, etc. Band Saws in narrow widths for home shop machines. Circular Saws in all sizes to fit your power saw outfit—cross-cut saws, tip saws, etc. Dado Heads to cut grooves! Metal-Cutting Circular Saws! Grinding Wheels and Files to sharpen tools speedily! Cabinet Scrapers of Silver Steel! Saw Filers and Saw Sets, etc. Just ask to see ATKINS Saws and Tools-at your Hardware Store. Four FREE Booklets Every tool user should have **Saw Sense,"’ “Saws in the Home,’ ‘*Dado Heads"’ and ‘Circular Saws’’—four hel ful booklets ATKINS offers FREE. Just send us the coup mn = E.C. ATKINS & CO. ““*s,. 428 S. Illinois St. Indianapolis, Ind. = “a me Send me Booklets ‘‘Saw Sense] ‘‘Saws in the Home” “te S for best Photo ("Dado Heads’’[] ‘*‘Circular Saws’’[ and full information ™, of a Home Work- on your Home Workshop Photo Prizes(]. shop each month Name............ Write us today for ‘‘Rules of ATKINS Photo Contest”’ offering $10.00 each DINE 65 65:66 50.05.05 0s 02 an apiaties hecmeautiates tae ae month for best photo of a Home- Workshop interior, and second prize of My Dealer Is... $5.00. Act NOW! Send coupon, hina ERS ORES) “Silver Steel’ Hack Saw BLADES And 10 Other Kinds of ATKINS Saws and Tools for YOUR Home Shop 400" is the finest hand saw made. Sil- lade. handle of Rosewood. ATKINS | Romn @) SCRAPER This Back Saw has ’ rigid Silver Steel ATK | | S blade. Apple wood [EMMsy Nets handle. 8 to 18 in. blade lengths. SAW ATKINS CIRCULAR SAW S Nickeled steeladjust- i“ able hack saw 4 AT K | bs) — Non ~ Breakable or a Silver St eel Blue- :! 8. sabaaaiaiaer ss ATKINS Da End Blade eads is a quick, No.!IO HACK SAW ATKINS he GROOVER OR DADO HEADS ATKINS offers you Silver Steel Narrow Band Saws, in many lengths and widths for small machines, These McKam Tooth ATKIN Ss Saws are jualled M°SKAM TOOTH for = work, im CIRCULAR SAW po | le Machine Knives in sizes for small work- shop planers, up to the largest machine- knife cutting job. ATKINS CIRCULAR MITRE SAWS ATKINS MACHINE ATKINS Mitre Saws are ideal for fine, smooth cabinet work. It planes as it saws Made of Silver Steel! ATKINS Circular Metal-Cutting Saws, of various diameters and thicknesses. Do fast, clean work. © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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120 POPULAR SCIENCE MONTHLY

NEW. MODEL DUTH BEND LATHES a FOR THE ™

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9-in.x 3-ft.Jur unior Back Geared Scréw Cuttin New Free Catalog shows all sizes od ; J Bench Lathe, wi from 9 inch to 18 inch * ersh ~§ Countershaft Driven Vathes, ; Count aft +169 | Motor Driven Lathes. Quick Pod re and Equipment Change Gear Lathes,Stand- 9” Rt ard Change Gear Lathes, Poa av 5 Toel Room Lathes.Gap Poe > 7. Prices of — Sizes of Quick Change Gear Bed Lathes, Brake 8 re Equipm rum Lathes and .. . o —= thes with Cc ne sil Ch Bench Lathes. t& shoes ; o ry : of Lathe Shi, ountershaft ilent ain rgha he wane Z Drive Motor Drive ASS. as o' x7 490 Ibs. $294.00 $398.00 + 41” x4’ 725 ibs. 359.00 498.00 we Seg? 13” x 5’ 1110 ibs. 443.00 602.00 oats 15” x6’ 1550 Ibe. 543.00 720.00 So%oe ; 16” x 8’ 2035 1 817.00 Ie PL WRITE FOR FREE CATALOG ese Pa SOUTH BEND LATHE WORKS KS ra 3 s 825; E. Madison Street, South Bend, Indiana,U.S.A. SS ey oO ¢ Lathe Builders for 23 years—44,000 users

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de Yet a World Famous CONN . on FREE TRIAL Any band or orchestra instru- ment ~at 4 on free trial. No obligation. Beauty of design; mechan bai a CLOCK ¢2isers FREE BOOK Shows how YOU Can Make bee fa Of Fine Clocks Right at Home Money - Makin, HOUSANDS of menhave ideas. Gives toh built our Clocks. For tions, "pe descrip- their own use— or to sell — ae and ®t money-making prices. It's parts. s.WriteNOW easy, fascinating. Only ordi- or your copy. nary tools needed. We furnish plans, instructions, parts. Works all assembled, ready to

inilinnes of tone mat acco install, as low as $1.65; others that nothi than a Conn with chimes at all prices. You can completel make the case, or simply as- More than 50 years’ experience semble knock-down parts. Cash-in on the demand for craftaman-built Mantel Clocks, Ban- satisfy you rie esses e possible ’s ‘ l Write Now for illus- Dverf Conns, Yet they cost i S Clocks, ne : AYSin trated book and details | 20more. Usedande y ere’s a hobby t in famous artists. | pleasure, in ownership and of Pree Trial and St: Ltd spare-time or full-time PROFITS! a pn agg SF | Write for FREE Catalog and Special Blue Print Offer AMERICAN CHIME CLOCK COMPANY ‘ 1691-H Ruffner St. Philadelphia, Pa, A SHIP MODEL FOR $4 98 Build the historic Santa Maria LaPinta or the Mayflower. We send you C.O.D. the are cut to fit, ready to a for 34.98, plus a few cents

Breed squabs and make money. Sold by millions at higher prices than chickens. Write at once for two free books tell- ing how to dc post Machines » My Shapting & Mangers \ at F6L2 unclutiad bucky You f ef A Complete Woodworking Shop foro

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A combination of machines on which you and a couple of helpers can work at the same time. Write for de- tails. 15 days approval, money back guarantee. Scott Bansbach Mach. Co. 148 So. Clinton St., Chicago, tt.

Aucust, 1929

Reseating a Chair with Cane Paste this Home Workshop Refer- ence Sheet, including the head above, in your scrapbook in the sec- tion marked furniture. (August, 1929, POPULAR SCIENCE MONTHLY.) What materials and tools are neces- sary to reseat a chair with cane web- bing? ANE webbing, either open or close woven; splines, preferably of reed, if the groove in the chair is curved; glue, and a sponge or cloth and water. Machine-woven cane webbing may be ob- tained in either open or close weave, im various widths by the running foot, and in several sizes of canes and meshes. Open-woven cane web- bing of “‘fine-fine’’ cane is the kind and size generally used for reseating chairs. Splines are narrow wedge-shaped lengths of reed or wood. They are forced into grooves with the webbing, and their function is to hold the cane securely in place. These are sold in lengths of about 10 ft. each and in three sizes. The medium size should be used with fine-fine cane webbing. The toois required are a mallet or hammer; \y-, 4-, and 34-in. chisels; wooden wedges (to be made); a pair of heavy scissors or tinner’s snips, and a jackknife. How is the seat frame prepared for caning? 1. Cut off the webbing with a knife next to the spline. 2. Remove the spline with chisel and mallet (see Fig. 1). 3. Clean out the cane ends and glue with a chisel. 4. Wash the frame with soap and water. Scrape the inner surface of the frame if necessary. What is necessary to prepare the ma- terials for use? 1. Make about five wedges of 14-in. hard- wood in several widths varying from 1 to 2 in. Taper them at one end to } in. in thickness. FIG_2_ TRIMMING FIG. 2 REMOVING SPLINE THE WEBBING WITH CHISEL

VY} | Ly (wood SCREW

Yiy Y, SEAT UW FIG. 4 - SIMPLE DEPTH GAGE

FIG.3 SCORING WITH MARKING GAGE Figs. 1 to 4. Steps in removing a spline, cutting the cane, and marking and testing a groove. 2. Lay the webbing over the frame and with scissors or snips cut the piece so that it extends over the groove about 1 in. all around. 3. Soak spline and webbing in water until thoroughly pliable. (Continued on page 121)

@ This seal on an adyertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

ron: ea a

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Page 123

|929 a; n a 2a qT “iw Bod ee Aucust, 1929 POPULAR SCIENCE MONTHLY 121 Reseating a Chair (Continued from page 120) Warm water will speed the softening process. 4. Fit the spline loosely in the groove, if the ve is a curved one, and cut it to length. Make the joint at the back of theframe. If the corners are angular, cut miters on the splines. What is the method of caning the seat? allowing the parallel strands of cane to run parallel with the front edge of the frame. Drive the webbing into the front groove with a wedge. Let the wedge remain. opposite groove. B Fig. 5. Corner of a seat frame which shows webbing trimmed at A and spline inserted at B. 3. Repeat the process with two more wedges at the other two grooves. 4. With another wedge force the webbing in the groove entirely around the frame. Remove the fixed wedges as the work progresses. 5. Cut off all ends of the webbing with a chisel in the bottom of the groove at the outer corner (see Fig. 2). 6. Run glue into the groove and distribute it over the cane and sides of the groove. 7. Drive the spline in with a mallet, pro- tecting it with a block of wood. Be careful that the curved edge of the spline is not driven be- low the surface of the frame (Fig. 5). What finishing is necessary? 1. Sponge off all excess glue. 2. When the webbing is nearly dry, the hair- like projections, if any, may be removed by passing the webbing over a gas flame. Be care- ful not to burn the cane. 3. When the cane webbing is to be left a natural color, it will look better and last longer if it is given a coat of tough, elastic varnish. When hand-woven seats are to be re- placed with machine webbing, what are the steps to follow? 1. Cut off the old seat with a knife, clean out all ends of cane from the holes, and wash the frame with soap and water. 2. File the spur of a marking gage to a knife edge. Set the spur to coincide with the inner edges of the holes, and gage entirely around the seat frame. Repeat the process several times so as to make the scoring rea- sonably deep. Continue the scoring in inacces- sible places with a knife. 3. Increase the gage setting 3¢ in. and again score entirely around the frame (Fig. 3). 4. Cut the groove 4 in. deep with a chisel in the same manner as spline is removed (Fig. 1). It is advisable to make a simple depth gage (Fig. 4). A router plane may be used to finish the cut if available. Clean out the groove thoroughly. Round the corners slightly with a chisel or sandpaper. 5. Proceed with the reseating as previously explained.—L. D. Perry. 1. Place the webbing over the seat frame, | 2. Drive the webbing in with a wedge in the | i — ABtop Wi) Put new incentive in front of If) Wyn | Weary, m/|) 4 if ‘ ) / Me ee , y Te your workman. Get him pushing ee for high production—watching his work add up 3 == - on a Veeder-Root Counter. Let him see his efforts COUNT in pieces per day or hour. So he'll be encouraged to do more, earn more—and you'll know you get all you pay for. Saving over- runs and under-runs by counting the work as produced The Veeder-Root Catalogue will show you Counters to register increased production at ANY machine. Sent free to all who may meet with the problem—in invention,engineering or manufacturing. Noedau—/RQOTinconronaree ‘IPARKS y} WOODWORKING MACHINES = | ‘ar-5 this real Laborato MICROSCOPE You can own this accurate German- made, professional, laboratory micro- scope for 50% less than the cost of an ordinary low-powered instrument. A perfect microscope for biological and technological work; magnifies 20 to 220 diameters; 4” by 4” stage with clips fully adjustable for finest observation; draw tube per- mits use of additional objectives; iris diaphragm with plane and con- vex mirrors under stage regulates light. This fine compound pre- cision instrument complete in wooden cabinet only $36 postpaid. Buy direct and save at least 50%. Money refunded if not satisfied after 5-day trial. Write for free copy of, **Exploring Invisible orlds.’ Appa € ring Co. er 2006 Chestnut St., Phila., Pa. f Guaranteed ten years Cabinet Shep No. 10 $290 | with Motor >. You ought to have xe this handy Parks in your shop. Compact, complete machine de- signed like a big production outfit at 1/5 the cost. loor space required only 42x72 inches. Does any kind of cabinet or joinery work. Write for circular. The Parks Woodworkin Machine Co. Canadian Factory: 338 pty ineinnat —_ it, Montreal Worlds Wonder Wrench Banishes Old Style Wrenches? Strong, convenient \ TOOL CHESTS that will give the ut- most service under all conditions. GERSTNER Chests are made that way. Free Catalog. H. GERSTNER & SONS 568 Columbia St., Dayton, Ohio. IT’S EASY TO BUILD THINGS You can perform every woodworking opera- tion with greater speed, accuracy and econ- omy on Boice-Crane’s o Universal Handisaw Table 15 in. x 17 in. Table 8 in. dia. tilts 45 ane tee ewes int de tara rooving. ngs 9 in. saw, cuts . Y in. stock. Insert takes 6in.x 10. Uses blades % in. to 1 in. dado head, cope heads and 8 in. wide. Bronze bear- in. sand disc. in, Jointer nes. Speed 660 R.P.M. Height po 14 in. Sold with or without Send 10c for new catalog “‘C’’ describing and illustrating Boice-Crane’s Universal Jig Saw © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. lete line of_ band srape Hon saws, circular saws, mortisers, jointers, lathes and the ice - ksh x “WB kJ Ee. BOICE Dept. P.$.8-E TOLEDO, OHIO

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122 POPULAR SCIENCE MONTHLY dir Men—you who love to tinker—here’s just the soap you need. LAVA cleans quickly and thoroughly the toughest-looking pair of hands that ever around awork bench. Makes more lather in 15 seconds than ordinary soap in 60, and even hard or cold water won’t dis- courage it. Millions useit. “Good old Lava,” they callit. Gets hands clean! Not just “‘sur- face clean,” but clean ‘way down deep. As easy on your hands as fur-lined gloves—because it’s made from fine vegetable oils and pulver- ized Italian pumice that’s almost as fine as flour. All grocers and druggists sell it. Sample cake of Lava Soap FREE! ove mcen= Mail this coupons °*°°--- Procter & Gamble (Dept. X-829) Cincinnati, Ohio. Please send me, FREE, a sample cake of LAVA, the hand soap that removes all the dirt and grease, Build This IDEAL Flying Model of the FORD MONOPLANE A PERFECT 3-ft. miniature of the “Floyd Ben- nett," the Tri-motor plane now used by Com- marder Byrd in the Antarctic. Anybody can build and fly it. The IDEAL Com lete Construction Out fit contains everything need all parts, fittings and materials, fuil plans, diagrams and instructions. The Model is guaranteed to fly when corseetty built. COMPLETE CONSTRUCTION OUT vir (West of ver, Colo. and in Canada $9.00 7 Ask Your Dealer, or Order Direct Plans for Model Airplanes [-::=.== Some te yy — 1/2-nize Pt with Q of ts ing-Ply necragtions =! one | =) Oe Folrwing: Fi ew Pork: ‘aris; | — | Curtiss; DeHiA ILLAND; NC-4/ , , Diane: ‘Bleriot; : kaube or Sino. EACH OU sa ewneess 25c Free with each plan. 64-Page Book for Medel Builders Contains plans for building Gliders and Rac- ers; = information about Scale Mogels: fad complete catalog of Parts, Materials. and Fittings for all kinds iy ah Models. Postpaid for...... 5c Ideal Aeroplane & Supply Co., Inc. 28 West 19th Street, New York City TO CAST LEAD sououns, estas, Wad and — ne ~ models. Easy and inexpensiv: I furnish all necessary Ceenee, TRAPPERS Wonderful ‘“True to Life’’ material. Send 5c Stamp for TMlustrated ‘Gataloges. Henry C. Schiercke, 1034-72nd St., Brooklyn, N.Y. | Home Workshop Chemistry (Continued from page 107) 1 in. wide. By crosslines 14 in. or more apart, divide the strip in fifty oblong fields. Also obtain a cake of cobalt blue and one of rose color—both water colors—a glass of water, and a fine camel’s-hair brush. Borrow a calibrated hygrometer, if possible, and hang it up in the bathroom on a particu- larly dry day. Place the impregnated paper on a board set across the bathtub or in some other convenient position. If the air in the room is so dry that the hy- grometer shows practically no moisture, paint the first field on the strip of drawing paper with cobalt blue so that the tint corresponds exactly with the color of the treated paper. Then turn on the hot water, and as the bath- tub fills, watch the hygrometer carefully. When it indicates two degrees of moisture, quickly paint the second field on the paper tape the same color which your impregnated paper shows. Continue in this way as the hu- midity increases at two-degree intervals until you have completed the series of fifty fields, each representing an increase of two percert in humidity. WATE colors do not look exactly the same when dry as when they are first applied, but the difference is not enough to cause any serious error; and, indeed, you can allow for the change if you do a little preliminary experi- menting. After the paper ribbon with the painted scale of tints is dry, mark each field with the number of degrees of humidity which the color represents as indicated by the hygrometer. This calibrated strip enables you to determine with fair accuracy the percentage of moisture in the atmosphere by comparing the tint of the impregnated paper with the color scale. The impregnated filter paper will retain its sensibility to moisture and hence its value as an indicator indefinitely, provided it is kept clean and free from dust. A simple, convenient, and effective way of mounting the paper is to suspend a strip of it in a vertically mounted glass tube, open at the bottom and covered at the top with a loose layer of absorbent cotton. If the impregnated filter paper is to serve as a calibrated hygrometer for scientific purposes, it is better to mount a square of it behind glass in a small framelike box, which should be open at the bottom and sides to admit the air and at the same time protect the contents from dust. In the center of the paper a small window should be cut out, corresponding in size to the oblong fields of color on the calibrated color scale. This strip of paper should be so mounted behind the filter paper that it can be slid up or down until the color of the field of the scale matches exactly the color of the paper. The figures on the calibrated strip ‘will indicate the degree of moisture.—Ernest WELLECK. Painting in Damp Weather AMATEUR house painters are told repeat- edly and emphatically never to attempt to paint in damp weather. Occasionally, how- ever, it is necessary to take a chance for some compelling reason, as when any delay would interfere with other essential work. In such cases it is wise to follow the example of pro- fessional painters and apply the paint with exceptional vigor, brushing it out thoroughly in a thin, uniform film. Prolonged and painstaking brushing will counteract some of the adverse results which come from painting in damp, chilly weather and will lessen the likelihood that the paint will wrinkle. Since oil thickens in the cold, it is permissible to thin the paint slightly with turpentine, even the last coat, which ordinarily should carry very little turpentine. Add only sufficient to allow the paint to be brushed out thin; too much will reduce the gloss. Aucust, 1929 Over the Mountains from Los Angeles 39 Mile FIVE Think of it! MILES over rough Wt anrrny | Seats, burning only HUNDR-D FIFTY-NINE ELEVEN GALLONS OF GASO Imagine more than FIFTY MILES TO THE GALLON. That is what the WHIRLWIND CARBURETING DEVICE does for D. R. Gilbert, enough of a saving on poe one trip to more than pay the cost of the Whirlwind TE WHIRLWIND SAVES MOTORISTS Miuwions OF Dowars YEARLY Whirlwind users, reporting the results of their tests, are amazed at the results they are getting. Letters keep streaming into the office telling of mileages all the way from 22 to 59 miles on a gasee. resulting in a saving of from 25% to 50% in gas bills alone. Mark A. Estes writes, “I was making 17 miles to the gallon on my Pontiac Coupe. Today, with the Whirl- — I am making 35.5 miles to the gallon.” 'P. Goerzen writes, “34-6/10 miles with the Whirl- wind. | a! a a oe) of 21 miles to the gallon.’ R. J ‘The Whirlwind increased the mileage on pany Ford. ‘truck from 12 to 26 miles to gallon and 25% n speed.”’ Car owners all over the world are saving money every day with the Whirlwind, besides having better operating motors. Think what this means on your own car. Figure up your savings-—enough for a radio—a bank account— added pleasures. Why let the Oil Companies profit by your waste? Find out about this amazing little device that will pay for itself every few weeks. FITS ALL C In just a few minutes the Whirlwind can be installed on any make of car, truck or tractor. It’s actually less work than changing your oil or putting water = the battery. No drilling, tapping or changes of any kind It is to work perfectly on an make of car, truck or tractor, large or small, new model or old el. The more you drive the more you will save men ibutors wanted Free Sample and $100.00 a week offer Whirlwind men are making bi; profits supplying this fast selling device that car owners cannot afford to be without. territory is stillopen. Free —— offer and full particulars sent on request. Just check the coagpon Guarantee ' No matter what kind of a car you have—no matter how big a gas- eater it is—The Whirlwind will save you money. We absolutely guar- antee that the Whirlwind will more than save its cost in line alone within thirty days, or the trial will cost you nothing. We invite you to test ~ at our risk'and expense. You are to be the sole judge. — nae -Free Trial Coupon— ------—--- Whirlwind Mfg. Co., 999-35-E Third St., Milwaukee, Wisc Gentlemen: You may send me full particulars of your Whirlwind Carbureting device and free trial offer. This does not obligate me in any way whatever. ° Bs 6656 :66 5466600056 s0s esesedcceneesessceeeeues COUNT —— here x you are interested in full or part time salesman posi- ton. oe rcccegeccecccecscs STATE SAVE MONEY—MAKE MONEY ‘ue H & A BAND SAW The choice of thousands of factories, shops and manual training schools, A real heavy-duty outfit— not a play- thing—but reasonably priced. For home or commercial shop, it will enable you to save or make money on countless jobs. Write for attrac- tive folder and prices. HESTON & ANDERSON 808 Market Street Fairfield, lowa DIESEL ENGINES Marine and Stationary By Ensign DAVID L. JONES, U.S. Navy The most complete, thor- ouchly practical an! up-to- date treatise on the Diesel Engine ever published. It explains their construction, troubles, remedies, operation and adjustments, practical trials and tests and the ele- mentary thermodynamics of all types of the Diesel Engine. The book is fully illustrated with drawings of working parts and detail engravings. 400 pages. Price $5.00 Popular Science Monthly 250 Fourth Ave. New York, N. Y. ~ pisaions MARINE LocoMoTIVE STATIONARY _ A definite program for getting ahead financially will be found on page four of this issue. @ This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8. a oe arte

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1929

Aveust, 1929 POPULAR SCIENCE MONTHLY 123

Tools That Help You See (Continued from page 98) the work by way of the first mirror, and a reading glass may be used to magnify the jmage in the first mirror, as in the diagram at B. In this way the mechanic can keep a magnified image of the recess or bore before him without straining or moving in any way from his natural position. One of the handiest tools in the shop is a dental mirror for examining tapped, reamed, or recessed holes over % in. in diameter and small bores and recesses of every kind, as sug- gested by Fig. 13 below. With its long handle, it enables you to get down into deep places and reveal things you could never know otherwise. Because of its handiness the dental mirror makes an excellent inspection tool for many purposes. When necessary it may be used in combination with a small electric lamp. There remains our friend the camera, which, although not exactly the simplest kind of instrument, yet is owned by everybody and

I Pa! al all ea “e's SMALLEST INTERVAL 0625] 480 SMALLEST INTERVAL .0O5/

Figs. 13 and 14. Dental mirror and its uses; scales reduced in size by photographic method. therefore may be said to “belong.’”” How many times do we remember some hard-to-set- up job on the lathe, or some other odd “rig- ging” that we took hours to figure out, only to find when we had to repeat it half a year later that we had it to figure out all over again! A “shot”? with an ordinary pocket kodak, costing all told ten cents and ten minutes time, will preserve the entire set-up with every clamp, bolt, block, washer, balance weight, and other accessories and their exact arrangement. The writer for years regularly used such photographic records for all difficult or “touchy ” set-ups on automatic screw machines. If a photograph such as that reproduced at the bottom of page 96 saves only half an hour in getting a machine running, it will more than have paid for itself. Finally, there is the reducing ability of the photographic camera. This is especially useful for the experimenter. Fig. 14 at A shows a temporary but accurate scale required on a shopmade instrument; it was produced from a large-scale drawing by the camera to a degree of fineness and accuracy that would be utterly out of the question by hand. At B is a similar reduction of a regular length-measuring scale. In conjunction with a 10-power magnifying glass, such a scale may be used to read off lengths of .005 in. and to estimate .002 in. Contour distances such as those at C, the width of graduations, scratches, prick marks, and similar things that are other- wise difficult to measure, can be easily ascer- tained in this simple manner. A good way is to reduce a regulation 1¢-in. scale to one in which each ]%-in. division equals .005 in. as shown at D, which means that the picture of a scale 6 in. long will have

a length of .480 in.

Your Own

al This blue-prints furnished. Sent on 10 Days Trial Easy Terms

MAKE Summer Furniture

Do your woodworking quickly,easily with this man-sized motorized workshop. Efficient, practical in design. Equipped with powerful two-shaft motor that permits We will be glad carrying of two or three important operations at one time. Numer- $100 te furnish our ous other exclusive a ny og sae craftsmen appreciate. Complete ‘‘Delta’’ Handi-Shop includes all necessary equipment for Circular Sawing, Wood Turning, Scroll Sawing, Sanding, Drilling ——_s. .-~ ¥ bee ge Grinding and Buffing. Fullinstructions and complete set of working $1.00. Without obligation you can test the Handi-Shop under actual working conditions for 10 days in your own home. Send at once for FREE illustrated literature, giving complete description of the new 1929 Model “‘Delta’”’ Handi-Shop, and full details of 10-Day Trial Offer and Easy Payment Plans. Delta Specialty Co. 1661-67 Holton St., Milwaukee, Wis. Dept. B-89

Blueprints complete set of 10 working Blue-

Delta Speciality Company, Dept. B-89, 1661-67 Holton, St., Milwaukee, Wis. (Please send me, FREE, illustrated litera- ture describing 1929 model “‘Delta”’ Handi- Shop. Also details of 10-Day Trial Offer and Easy Payment Plans. CL enclose $1.00 for set of 10 Blue-prints of Summer Furniture.

SOUSERSeeeeeeseenansasaee,

Has wing eqrend 16 in. with main fuselage 16 ta-s Tin. carved wood

= C4 © > - 5 ele wits THE AF ARKOGR” Tools FromTheft. write with elec- Sores eae Tes Sed icramentne any metal, like writing on paper with Ota or Outfit $3.86 - Interest- ws illustra cir: free. Write to- > co. <== ED 1171-A East Stark St., Portiand, Oregon

propeller; ly rubber motor, Soars to great heights assembled. Sim; ly fasten wings and launch. Only 50c. Junior modd---it n : 4 ply rubber m - fat ice list. SPEEDO MFG. CO.” Depl. 5, 200 Albany Avenue, Brooklyn N. Y. ZIP-ZIP SHOOTER HOUSANDS of boys are made I happy with this wonderful nr a shooter, scientifically and practical made. If you like hunting and outdoor t yee get a Zip-Zip ——- Tm plenty ep an: orce. our dealer ippens 0 fave them, order trom us. Zip-Zip shooter 35c or three for $1.00; send stamps, coin or money order. AUTOMATIC RUBBER CO. Columbia, S. C. ere

oO! t

of Your Town You have heard of Tom Brown of the famous Tom Brown's Clown Band. You have prob- ably heard his records. You, also, might develop into a Saxophone izard and earn a princely in- come. Atleast, you can have alot of fun, be popular socially and in college, and earn easy money on the side. It’s easy to learn on af§ uescher True Tone Saxophone and easy to pay for it by our spe- cial plan. 6days’ trial on any Saxo- phone, Cornet, Trombone, Trump- et or other instrument. Mention instrument for Free circulars. Buescher Band Instrument Co. 2813 Buescher Block (505) Elkhart, Indiana

New Models now ready, for delivery direct [f terms, ‘Bo not buy until you get then.

The Waco Wonder Sho “i NOw 5

Aset Jacket Electric tools brings a power- ful Nose Det Motor, Waco Crafteman‘s wood Serning fot. sre enna bandeswe, and all eopes™ sa " an n r ae for ‘Grilling, buffing, inding and cleaning. Attaches to light socket an oe you private ma- chine shop. ONLY 810.00 DOWN. att — I 7 J You will be y nteresti: uf ure. You re ae F: aacinating. Beautiful, WACO TOOL WORKS, Inc. 5216 W. Kinzie St., Chicago. ° Please send me all information FREE. @ This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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a) User THE ASHSALES Consiy N. Ashiand Ave., CLIP_HERE ~ Mane Fo Also FREE Oving amating 125-Pleture stery st The“Pocket Machine Shop!” with its 1-TON POWER-GEAR it Outgrips a 40-Lb. Visel g to . 22 EC pangs zee Pema Se ai Wr: toe Tar) An Automatic Nes'and Clamp, making Work, etc. E\FEL-ELASH. PLERENCH KIT Gay “Eye-fel—Flash””) “The T.N.T. of Tools"’ to With each Kit.g 64-page Manual of Mechanics {A QUARANTEED) SUPER-QUALITY PRODUCT (©'29-J.E.) Big Year Money-Maker for Ple«efich factory S78'sa00 Time. Say x pee ee Here is a pleas- ant, easy wav to make BIG MONEY in a CASH BUSINESS of your own. Very little money required to start—no stock to carry—NO CAN- VASSING. Start in spare time and build a PERMA- NENT, SUCCESSFUL BUSINESS filing saws on the Foley Automatic Saw Filer. started on the road to F R E E P L AN SUCCESS. F Pl shows you how to get ali the business you can handle. A fine, STEADY INCOME the year ‘round — no dull seasons—REPEAT BUSINESS. Write Quick! Send for details atonce! Get start- ed making BIG MONEY. No experience rneces- sary. WRITE TODAY! Hundreds of men have Foley Saw Tool Co., Inc. 1008 Foley Blidg., 11 Main St. N. E., Minneapolis, Minn. POPULAR SCIENCE MONTHLY Aucust, 1929 Ornaments for Your Home (Continued from page 80) furniture, for which the majority of transfer designs are unsuited. Those which are made of wood composition will take stain practically the same as any wood surface. They may be stained like the flat surfaces, or very pleas- ing two-tone effects may be produced by wip- ing the stain from the carvings before it has commenced to set. In some cases it may be desirable to thin the stain before applying it to the carvings and afterwards to wipe it off, too, in order to obtain just the desired effect. As a rule, however, too great a contrast between the two tones should be avoided. Often a delicately beautiful effect may be gained by using sandpaper or steel wool to produce the high lights after the stain is dry, instead of wiping it off when wet. In stain finishing no preparation of the sur- face is necessary; in fact, the stain must be applied directly to the surface so that it will have an opportunity to penetrate. The stain is followed by a thin coat of shellac, which seals it and keeps it from bleeding through the finishing coats of varnish. Where lacquer, oil paint, or enamel is used for the color decoration of carvings, it is a safe practice to apply a preliminary coat of shellac to seal the surface, although that is not necessary with some of the makes of ornamental carvings on the market. The second type of relief designs—those for wall decorations—may be obtained in the form of panel medallions, borders, friezes, panel moldings, cove cornices, centerpieces, over-fireplace panels, plaques, pendants, pilas- ters, and rosettes. Wall relief ornaments are applied on top of the plaster. The heavier cast relief forms are cemented in place with plaster of Paris and glue size, or plaster and lime. The pressed fiber and lighter composition ornaments are usually applied with wall paper paste or plastic paint. Where wall paper paste is used, it is brushed on to the back of the ornaments (several at a time) and allowed to Coloring an ornamental carving applied to the otherwise plain door panel of a china closet. soak in for five minutes or so.. Then another coating of paste is applied, and the ornaments are placed on the wall. They should be pressed tightly into contact with the surface, which is best accomplished with a flat wooden paddle or other instrument, pushed hard against the low places of the ornament. Care must be taken not to flatten out the raised parts of the design while it is wet with the paste. Any wrinkles or buckles in the flat part of the relief may be smoothed out with a paddle or a putty knife. When ornaments are applied over bare plaster, the wall first should be sized to prevent the paste from soaking in. Plastic paint, if available, affords the best a Carved design composed of three separate pieces. When a unit of the desired shape can- not be had, it is often possible to combine two or more ornaments. In finishing the carving, stain is applied freely, then partly wiped off. method of applying the pressed fiber orna- ments. The same@rocedure is followed as with paste, except that the plastic paint is pressed into the crevices at the back of the relief form until they are a little more than full. This method gives a solid surface when dry and insures a firm, smooth job. When used in rooms that are done through- out in plastic paint decoration, the ornamental forms are simply pressed into the plastic paint, which holds them securely in place. All of the usual forms of wall and ceiling color treatment may be used over these orna- ments. Being more or less porous or absorbent, they ordinarily require the use of a size or priming coat to seal the surface just as do bare plaster walls. Afterwards they may be brush coated with wall paint, “Tiffany” or sponge stippled, two-toned glazed, or dusted. The use of the pressed fiber type of ornament offers a number of desirable mechanical ad- vantages over solid plaster, which, in any case, the amateur cannot easily apply. They do not crack or check, and, being somewhat flexible, they conform to any irregularities of construc- tion. It is not necessary to saw and trim them to an exact fit; imperfect joints and crevices may be filled with plastic paint or plaster of Paris and paint. In fact, when fiber moldings are applied with paste, it is preferable not to butt them tightly together, but to allow about Yg in. between lengths for expansion, the gap to be filled with any suitable composition when the moisture from the paste has dried out. The possibilities of relief ornamentation are almost unlimited. Ceiling centerpieces may be used in sets with larger and smaller ones of the same design in adjoining large and small rooms. Another method sometimes employed is to repeat detached motifs at intervals and tie them together with lengths of a suitable border design. Relief forms in period motifs also are obtainable for use in period interiors. Hints on Sharpening an Ax N SHARPENING an ax for chopping, give the blade a long bevel and a fine, sharp edge. For splitting, on the other hand, the blade should not be ground so far back because its purpose is to wedge the wood apart quickly and tear the fibers, not cut out large chips. If you do considerable splitting and chopping, it is well to use a double-bladed or double- bitted ax with one splitting and one chopping edge.—ArTHUR KEIL. © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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» 1929 l- 1a- ith ed rm his nd h- tal nt, ng a- it, or re sh ve at :. 4 SF eee eee Aucust, 1929 from the cellar to the attic radio may be enjoyed through the installation of Carter Wall Plates The use of Carter wall outlet plates enables you to bring aerial, ground and power leads to your receiver through one out- let, eliminating the in- convenience of several wires from various points. Adding loud speakers to various rooms gives the advantage of extra radio sets by simply plugging into Carter Wall Plates. _. Send for catalog Carter Radio Co. P-S-8 es: , Chicago, Il. POPULAR SCIENCE MONTHLY Install Amperite for every tube and smooth out *‘A’”’ $1.10 with mounti: ng current wabble that ruins (in ao S. - ) atal reception. Amperite ad- dealers. jue itself to the exact of each tube. A type © — — for every tube—A.C.orD. C. \ \ Radial | Compa pmpary- \ WRES Amportts Metheute of modern circuits and Write Dept. PS 8 TONATROL Your dio henge ELECTRAD TONATROLS give smooth quiet adjust- ment of radio volume. Built to last. A model for every type receiver, battery or electric, with or without filament switch attached. $1.50 to $3.00. Also, Super-Tonatrol for high-power re- ceivers. New—different. Extra long-lived. $2.40. Write Dept. PS8 for circular. 175 Varick St., New York, N.Y. ZRAD= =ELEC AIRPLANE 12-inch scale model of fi irit of St. Louis. lesigned and ve: all parts and foe. oe Pe oree 3 “mon Rae y back. MANN ; DEWTGN = Box E Chillicothe,Ohie Experiments with 110-Volt Alternating Current By J. D. ADAMS Here at last is a book that develops a practical working familiarity with the alternating current— the form in which electricity is used in every home. The author shows how this can be done in an in- expensive way. 256 pages, 135 illustrations Price, postpaid, $1.75 POPULAR SCIENCE MONTHLY 250 Fourth Avenue New York Pattern for Cutting Strong Moccasins Two-piece moccasins which require a minimum of sewing, yet are strong and comfortable. STRONG, serviceable moccasin can be made of two pieces of leather cut as shown in the drawing below. The leather used should be fairly flexible, but not too thin. The seams are made by butting the edges together and sewing through them with heavy waxed linen thread so that the thread is concealed wherever it crosses the joint. The rear vertical seam should be sewn first; then the rear horizontal seam should be sewn from the center each way, because a certain amount of pucker will MOCCASIN = | )(3-of How to lay out patterns for. cutting the two pieces. The dimensions are for a man’s mocca- sin corresponding to about size No. 9. be necessary in order to make a smooth joint. Similarly, the top piece should be fastened at the center of the toe and sewn both ways. The dimensions given will make a moc- casin of about men’s size No. 9. By cut- ting down the center of the top piece for 2 in. and inserting eyelets, a lacing can be used which will adjust the moccasin to larger or smaller feet. For foot sizes con- siderably smaller or larger than size No. 9, the pattern should be adjusted from a standard foot chart.—Rosert T. Pounp. Emergency Beading Tool N AN emer- gency a saw- tooth corrugated fastener is a good tool for scratching ornamental beads in wood. A wood- en strip may be Corrugated fastener used used as a guide.— tocut beads. Itis advis- RaymMonp WaILEs. 4bletohold it with pliers. 125 TUALLY TL LONGER PRONOUNCED SEE —c€ Radiotu —better tone quality and clearer reproduction If you want a thrill from an extra- fine performance of your radio, in- stall a complete set of CeCo Tubes at one time. Users of CeCo Tubes have learned to expect exceptionally faithful re- production of tone quality. They also know that it is not necessary to shift tubes from one socket to an- other in order to obtain the best re- production their set is capable of giving —the high quality and char- acter of CeCo Tubes are uniform. There are 64 reasons for this. Every tube that leaves the CeCo factory is thoroughly seasoned and given 64 exacting tests for uniform- ity of quality and characteristics that affect successful radio reproduction. The result is not only uniformity, but much longer life as well. If you need just one tube, try a CeCo. As the other tubes wear out, install CeCo’s until you have a com- plete set. Then call in your neigh- bors and ask them if they ever heard better radio reproduction. Hear the CeCo Couriers — Every Monday night at 7:30 P. M. Eastern Standard time over the Columbia System. CeCo Manufacturing Company, Inc. PROVIDENCE, R. I. Licensed under patents and applications of the Radio Corporation of America, the General Elec- tric Company, and the Westinghouse Electric and Manufacturing Company. ° e % MOUVNSNNU Aco nLUOEOOOULAOVOTEROU AUPE © This seal on an advertisement in POPULAR SCIENCE MONTHLY signifies the approval of the INSTITUTE OF STANDARDS. See page 8.

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126 POPULAR SCIENCE MONTHLY Aveusr, 1929 Advertising GET Into aevesteing, 5 —— quickly # bome, Ex- perieney, unnecessary. ew t books used. ractical work. Old “established schol — name Ra address for interesting free booklet. Davis School of Advertising, Dept. 174-C, 3601 Mich gan, Chicago. Advertising Services 24 WORDS,-151 rural weeklies, $6.04. Ad-Meyer, 4112P Hartford, St. Louis, Mo. Aviation SIMPLEX Air Model Co., Auburn, Mass. Send 5 cents for supply booklet. “SKYWARD HO!" Wonder book on aviation—32 pases. 150 illustrations. Shows you complete training ‘or flying career, fame, fortune! t free. Write today Parks Air College, 215 Mo. Theatre Bldg., St. Louis, Mo. ana American School of Aviation announces a new correspondence course in Mechanics of Aviation. A thorough training in Practical Aeronautics. American eee of Aviation, Dept. 6742, 3601 Michigan Ave., cago, I BIGGEST, Best Catalog Model Airplanes, Part Supplies; 5c¢ Seen Ideal Company, 21 West iBek Street, New York FLY in your own home built sport plane. peed two stamps. Chas. Russell, Box 455, Toledo, Ohio. MODEL airplanes that fly—supplies for all papas. Complete " of accessories. Send 10 cents for 56 p: . Model Aircraft Corp., 397-C Bridge’: St, MODEL Airplane Builders. Send for free Catal Shifier-Smith construction set, $2.50. Tudor-Morris construction set, $2.75. Lind dbergh Plane construction set, $3.25. ockheed-Vega construction set, $5.25. New Model ROG. kit, $0.60. Fine Blueprint for any above model 25c. Model Airplane Supply, 29 Nort Ave., New Rochelle, N. MOUNTE > propeier 12 inches with circulars on free three foot model 25c postpaid. Aero Shop, 3050 Hurlbut Avenue, Detroit, Michigan. LOCKHEED-VEGA model — compressed air, record rubber model kits, supplies. Illustrated manual bargain list 10c. Advanced Peru Model, Peru, Indiana. Rates 40 Cents a Word. A 10% discount is allowed on all contracts for six consecutive inser- tions. Advertisements intended for the October 1929, issue should be received by Sept. 5th. Submit details of proposition with order. Business Opportunities MIRRORS resilvered at home. Costs near 5 cents per square foot; you charge 75 cents. Immense profits plating autoparts, refiectors, tableware, stoves. Re- finishing metalware, ete. Outfits furnished. Details Free. Write Sprinkle, Plater, 94, Marion, Indiana. INVENTION Commercialized. Patented cr un- patented. Write Adam Fisher Mfg. Co., 183 Enright, St. Louis, Mo. WE START you in business, furnishing everything. Men and women, earn $40 to $100 weekly operating our original ‘“‘New System Specialty Candy Factories.’ Begin home spare time. Unlimited opportunity. Val- uable booklet free. W. Hillyer Ragsdale, Drawer 19, East Orange, N. J. AS A business proposition Stock privileges offers many advantages; profitable and interesting, small or wg tal as desired. Write Paul Kaye, 11 W. 42nd LEARN Dry Cleaning! My book formulas teach you. Make money in your town, be independent. Price $1.00. Hoffmann Laboratories, Boulder, Colo. HERE'S a chance to get into a permanent and profitable business with your earnings keeping pace with your ability. We teach you. You earn from the Start. Beginin your own locality. You join — 000, — company. A big, national advertiser. We hav for a few more reliable men. Write Dept. C, The * Piller Brush Company, 3580 Main St., Hartford, Conn., for full particulars. For Inventors UNPATENTED Ideas Can be Sold. I tell you ou how and help you make the sale. Free particulars (Cc opy- righted). Write W. F. Greene, 905 Barrister Building, Washington, D..C. INVENTORS’ Universal Educator—contains 909 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. PATENTS, If you have an invention which you wish to patent you can write fully and freely to Munn & Co., for advice in regard to the best way of obtaining Protection, Please send sketches, or a model of your invention and a description of the device, explaining its operation. All communications are strietly confidential. Our Hand- Book on Patents is sent free on request. This explaing our methods, terms, etc., in regard to Patents, Trade Marks, Foreign Patents, etc. ‘Scientific American” contains Patent Office Notes, Decisions of interest to inventors and particulars of recently patented inven- tions. Munn & Company, Solicitors of Patents, 524 Scientific American Bldg., Washington, D. C.: 1523 Sei- entific American Building, 24 W. 40th St.. New York City: 1313 Tower ae. . ores: Ill: 666 Hobart Bldg., San — Calif.: 521 Van Nuys Bldg., Los Angeles, INVENTIONS Commercialized. Patented or un- patented. Write Adam Fisher Mfg. Co., 183 Enright, St. Louis, Mo. Formulas SUCCEED With Your Own Products. Make them yourself. Formulas, Processes, ‘l'rade-Secrets. All lines, ee. circulars free. C. Thaxly Co., Washington, Cartoonists AMATEUR Cartoonists: Sell your cartoons. New plan. Smith's Service, PS1194, Wenatchee, Wash. GUARANTEED Formulas: “Exclusive But Not Expensive” For Va Largest Selling Specialties. All Lines. Play Safe, get my Valuable, ‘‘Eye-opening” Literature before buying common Catalogue’! Stock —— Miller, Manufacturer’s Chemist, Tampa, lorida. Chalk Talks INDUSTRIAL chemist furnishes formulas, processes; all lines. Individual service. Moderate charges. Clore, Industrial Chemist, Crawfordsville, Ind. LAUGH producing program, $1.00. Catalog free. Cartoonist Balda, Oshkosh, Wisconsin. For the Home Charters Bending Machines DELAWARE Charters; fees small; free forms. Chas. G. Guyer, Wilmington, Delaware. THE Famous Hossfeld “Wrenchless’ Universal teen penéet is the last word in bending machines. Bends 1 cold or hot into most any capemvelis shape, in- cluding E - Bolts and a ag Spring Fyes. hs — rs or 1%” pipe cold. Thousands in use by classes of Saae from the smallest shops te. the largest railway systems. Write for circular and prices. Hossfeld Mfg. Co., Winona, Minn. Books and Periodicals Chemicals 1929 BOOKLET of Chemicai Experiments. Illus- trated, 15c. General Chemical Company, Box 397, Reading, Penna. CATALOG listing 2500 illustrations chemists’ sup- plies, 5000 chemicals, 1000 scientific books sent for 50c. — Materials Company, 641 East 71st St., Chicago. 4TH EDITION Revised and down to date. “Radio Theory and Operating,"’ by Mary Texanna Loomis. The standard radio text and reference book of America. 992 s, over 800 illustrations, flexible binding. Price, $350, postage paid. For sale by hundreds of book- dealers throughout America and many foreign countries. Or may be purchased direct from the publishers. Send check or money order to Loomis Publishing Company, Dept. 22, Washington, D.C Business Opportunities LEARN the collection business. Good income; quick results. Interesting booklet, “Skillful ye free. oy, Collector's Association, Science Building, New- ark, ¢ BECOME a Foot Correctionist. A New Profession not medical nor chiro y. All the trade you can attend to; many are making $3,000 to $10,000 yearly, easy terms for Aye by mall, no further capital needed or goods to y or soliciting. Address Stephenson Labora- ack Bay, Boston, Mass. tory. to USED correspondence school courses sold on —_— basis. Also rented and exchanged. Senar- k guarantee. Catalog free. (Courses bought.) Lee Mountain, Pisgah, Alabama. SUCCEED With Your Own Products. Make them yourself. Formulas, Ra se Trade-Secrets. All lines. rae @ circulars free. C. Thaxly Co., Washington, — Advertisement may make you Thousands of if you'll write immediately for my “Eye- Open s Literature describing Guaranteed Formulas; Trade Processes, a te = Information your Home, Room or Office. Make the oney ad gute to. Dr. Liscombe Miller, Chemist, GRANDFATHER clock works, $5.00. Bulld your own case, instructions free; make good profits selling your friends. Clock works with chimes for old or new cases. Write for full particulars. Clock Co., Nicetown, Penn. Help Wanted Instruction GOVERNMENT Jobs. Sumee-qaese year. women, 18-50. Steady jobs. No “layoffs. t work. Paid vacation. Short hours. Common education usually sufficient. Thousands 1929 —————. 25 coach Free. Write today sure for full particulars. Franklin Institute, Dept. W26, Rochester, N. Y. Men— Pleasan BEGINNERS instructed for hotel positions in Florida, Bermuda, California. Lee Hotel Institute, Drawer 1508, Boston. Dogs for Sale ST. BERNARD Puppies! Championbred parentage; reasonable, ~ | free, photos submitted: Helvetia Kennels, Dept. 8, Napierville, Que. Inventions Wanted INVENTIONS Wanted—Patented, unpatented. If you have an idea for sale write Hartley, Box 928, Bangor, Maine. Education and Instruction INVENTIONS Commercialized. Patented or un- patented. Write Adam Fisher Mfg. Co., 183 Enright, St. Louis, Mo. DON’T prepare for any Civil Service examination without seeing our free catalogue. Columbian Corte- spondence College, Washington, D. C. USED courses—Standard Correspondence Schools. Sold, rented. Guaranteed. Courses bought. Aneslys, 195 Woodward, Builfalo. “DOUBLE Entry Bookkeeping 60 hours with 8 Keys; guaranteed. (Diplomas.) International Bookkeeping Inst.—10, Springfield, Mo." BOOKKEEPING—Accounting and Auditing. Com- plete course 37 lessons. low cost. Write for free sample lesson. No obligation. sane Vocational Institute, Lyric Bldg., Richmond, Engines—Motors—“Dynamos MAKE Electric Motors—half and one horse-power. A. C. induction motor winding models show connections plain sight. Learn quick, easy. Dept. B, Gaines Bros., Gainesville, Texas. Farms and Farm Lands GET quick cash sale for your property anywhere. Details free. Write Fisher Agency, Hannibal, Missouri. Laboratory and Chemical Services YOUR chemical problem ogived and formula or process furnished for $5.00. Write me. W. Stedman Richards, Industrial Chemist, Box 2402, Boston, Mass. Lumber PLY WOOD—5 cents per foot and up. Particulars on application. MenSon 3502 South 54th Street. Tacoma, Washington. “SAMPLES 20 cabinet woods, 20 inlay woods either set $1.00 postpaid, both $1.75. Sets include rosewood, ebony, zebra, benin, vermillion. Send for catalogue. Craftsman Wood’ Service, 717 East 62nd Street, Chicago."’ Manufacturing Models, dies, stamp- SPECIALTY Manufacturing. plating, ings, casting, screw machine, wire products, enameling and assembling very reasonable. Quantity production. Estimates promptly furnished. Satisfaction guaranteed. Majestic Products Mfg. Company. Box 877, Chicago. a ———————

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a, 6 #21 irr aol Aucust, 1929 Miscellaneous G—wWorthy enterprises seeking capital $20, ee, consult Hansel Financing Specialists, Box 315-PX, Washington, D. C. D-OUT Electric Lamps Repaired one cent. We West Coast Lamp Co., 344 30th Street, san Francisco, Calif. Models and Model Supplies —— Machinery or parts, Dies, Tools, Metal SPECIAL fodel special gears, stock gears and Model pags ‘Send 5c for Catalogue. The Pierce Model Works, Tinley Park, Ill. Model Fittings: Catalog Dime. A. J. Fisher, wer Towah Ave., Royal Oak, Mich. eas A SHIP model for $4.98. Build the historic Santa Maria, LaPinta or the Mayflower. We send you C.O.D. the parts cut to fit, ready to assemble for $4.98, plus a few cents postage. No tools needed except a small ham- mer. Parts for model of Constitution sent C.O.D. for $6.98, plus postage. Write for illustrated catalogue. Miniature Ship Models, Inc., PP5, 3216 Baring Street, Philadelphia, Pa. Motorcycles MOTORCYCLE Bargains. If you are seriously inter- ested in buying a motorcycle of guaranteed standard make, at a enomenally low price—and really mean pusiness—this is your opportunity. We have at the moment some Harley-Davidson motorcycles, with prices ranging as low as $89.00. These machines are guaranteed to be in perfect condition. While they last, they are offered at a tremendous sacrifice. If you are seriously interested in buying a good motorcycle, send for descrip- tive literature today, as there are a limited number available for this offer. Heinz Motor Company, 621 West North Avenue, Baltimore, Md. Music and “Musical Instruments SAXOPHONISTS — Clarinetists — Cornetists — Trombonists—get ‘Free Pointers.” Virtuoso Music School, 36, Buffalo, N. Y. Patent cAttorneys PATENTS—Time counts in applying for patents. F Don't risk delay in protecting your ideas. Send sketch or model for instructions or write for FREE k, “How to Obtain a Patent” and ‘Record of Invention” form. No charge for information on how to proceed. Communica- tions strictly confidential. Prompt, careful, efficient service. Clarence A. O'Brien, Registered Patent Attorney, Security Bank Building (directly across street from Patent Office), Washington, D. C. (See page 135.) PATENTS. Booklet free. Highest references. Best results. Promptness assured. Watson E. Coleman, Patent Lawyer, 724 9th Street, Washington, D. C. UNPATENTED Ideas Can Be Sold. I tell you how and help you make the sale. Free porttewere (Copy- ted). Write W. T. Greene, 911 Barrister Building, ashington, D. C. LANCASTER AND ALLWINE, 232 Ouray 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. MONROE E. MILLER, Ouray Bldg., Washington, D. C., Patent Lawyer, Mechanical, Electrical Expert. Book- let and Priority Record blank gratis. PATENTS—Free instructions. Former Patent Office Examiner. Moderate terms. Booklet. Albert Jacobs, 725 Barrister Bldg., Washington, D. C. “INVENTOR’S GUIDE,” valuable information, free: Frank Ledermann, Registered Attorney-Engineer, 1714 Woolworth Building, New York. INVENTOR’S Adviser with mechanical movements sent free. Labiner, 3 Parkrow, New York. PATENTS procured at reasonable rates with time to en. Sales negotiated. Staff of registered attorneys and engineers. Write for particulars. Inventors Serv- os =. Dept. A, Union Trust Building, Washing- n, D.C. PATENTS Procured; Trade Marks Registered— Preliminary advice furnished without charge. Booklet and form for disclosing idea free. Irving L. McCathran, 705 International Building, Washington, D. C. PATENTS—Write for FREE Instructions. Send Drawing or Model for Examination. Carl Miller, Regis- tered Patent Attorney (former Patent Office examiner), 257 McGill Building, Washington, D. C. INVENTIONS patented; inventions developed; cor- respondence invited; confidential device; trademarks Stered; copyrights. Edward Gottlieb, Patent Attorney—Engineer, 5 Beekman Street, New York. INVENTORS who derive largest profits know and heed certain simple but vital facts before applying for tents. Our book ‘Patent Sense’ gives those fact Tee. Lacey & Lacey, 648 F. St., Washington, D. C Established 1869. Patents for Sale INVENTIONS Commercialized. Patented or unpat- ented. wee Adam Fisher Mfg. Co., 183 Enright, St. Photography Instructions MAKE money in Photography. Learn quickly at home. Spare or full time. New Plan. Nothing like it. Experience unnecessary. American School of Photog- raphy, Dept. 1743, 3601 Michigan Avenue, Chicago. 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. MONEY MAKING OPPORTUNITIES SECTION Amazingly Easy Way to get into ELECTRICITY Don’t spend your life waiting for $5.00 raises in a dull, hopeless job. Now ...and forever ... say good-bye to 25 and 35 dollars a week. Let me show you how to qualify for jobs leading to salaries of $50, $60 and up, a week, in Electricity—NOT by correspondence, but by an amazing way to teach, that makes you a practical expert in 90 days! Getting into Electricity is far easier than you imagine! Act now, today! Learn Without Books in9Q pays ACK of experience—age, or advanced education bar noone. I don’t care if you don’t know an armature from an air brake—I don’t ex- pect you to! I don’t care if you’re 16 years old or 40—it makes nodifference! Don’t let lack of money stop you. Most of the men at Coyne have no Jobs - Pay - Future Don’t worry about a job, Coyne training settles the job uestion for life. Demand for yne men often exceeds the supply. Our employment bu- reau gives you lifetime serv- for Jobs ice. Two weeks after gradu- ation, Clyde F. Hart got a po- more money than you have. bentions pane sition as electrician with the Railroad Fare reau gives youlifetimeemploy- 1 (Creat Western Railroad at Armature Expert | wees | Over $100 a week. That’s not Allowed Cit. : Substation Operator. wee} unusual. We can point to I will allow your railroad fare | 4°” to Chicago, and if you should | [pyenter_.. need part-time work I’llassist | s.rvice you to it. Then, in 12 brief [,,4; ee Ww eCnitmited Coyne men making up to $600 a sod $60 a mA 4 is only pp to $1008 Week? the beginning of your oppor- go» Wicck sod up tunity. You gointo radio, bat- weeks, in the great roaring shops of Coyne, I train you as you never dreamed you could be trained . . . on the greatest outlay of electrical ap tus ever assembled ... costing hun of thousands of dollars. . . real dynamos, engines, power plants, autos, switch- boards, transmitting stations. . . every- thing from doorbells to farm power and lighting . . . full-sized. . . in full oper- ation every day! No Books — All Actual Work No books, no baffling charts... all real actual work . . . building real batteries . «. Winding real armatures, operating real motors, dynamos and generators, wiring houses, etc., etc. That’s a glimpse of how we make you a master practical electri- cian in 90 days, teaching you far more than the average ordinary electrician ev- er knows and fitting you to step into jobs leading to big pay immediately after grad- uation. Here, in this world-famous Parent school—and nowhere else in the world— can you get such training! tery or automotive electrical business for yourself and make up to $15,000 a year. Get The Facts Coyne is your one great chance to get into cioctdialia, Every obstacle is removed. This school is 30 years old—Coyne train- ing is tested—proven beyond all doubt— endorsed by many large electrical con- cerns. You can find out everything ab- solutely free, and right now I'll include my new courses, Aviation Electricity and Radioand Automotive Electricity. Simply mail thecoupon and let me send you the big, free Coyne book of 150 photographs... facts... jobs ... salaries . . . op- portunities. Tells you how many earn expenses while training and how weassist our graduates in the field. This does not obligate you, So act at once. Just mail coupon. Mr. H C. LEWIS, Pres. S00 S. Paulina St., Chicago. Ul. Dear Mr. Lewis: Without obl Lette. SCHOOL ESTABLISHED 1899 500 S. Paulina St. «bac tion send me your big free cat- alog and all details of Fare to Chicago, Free Employ- ment Service, Aviation Electricity, Radioand cctomotive Ez. trical Courses and how I can “‘earn while learning.’’ Name. Dept. C9-73' Chicago, 1. | cir, Ribas 127 ae 1 | Be ee Ss eee Se a a te

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128 The only man who could talk to the Superintendent “Soon after I began studying,” a student wrote to us the other day, ‘“‘we had a change in management at our plant. I certainly was glad then that I had de- cided to study in my spare time. For, thanks to my I. C. S. course, I was the only man in the organiza- tion who could talk to the Superintendent in his own language. As a result, I was promoted over men who been here from ten to twenty years. My salary has been increased 90 per cent in the last ten months.” That’s a true story of what just one I. C. S. student has done. There are thousands of others. Every mail brings letters from men and women telling of promotions ¢_d in- creases in salary due directly to spare-time study. One hour a day, spent with the I. C. S. in the quiet of your own home, will prepare you for success in the work you like best. Yes, it will! Put it up to us to prove it. Mail this Coupon for Free Booklet ee ieee ee ee eee INTERNATIONAL CORRESPONDENCE SCHOOLS “The Universal University’ Box 7633-F, Seranton, Penna. Without cost or obligation on my pert, please sen’! me a copy of your 48-page booklet, “‘Whe Wins and Why,” and tell me how I can qualify for the tion, or in the subject, before which I have marked an X: TECHNICAL AND INDUSTRIAL COURSES Architect Automobile Work Architectural Draftsman [_] Aviation Engines Building Foreman Plumber and Steam Fitter Concrete Builder Plumbing Inspector Contractor and Builder Foreman Plumber Structural Draftsman Heating and Ventilation Structural Engineer Sheet-Metal Worker barat noe Engineer Steam Engineer ] Electrical Contractor Marine Engineer Electric Wiring Refrigeration Engineer Electric Lighting R. RB. Positions Electric Car Running Highway Engineer Telegraph Engineer Chemistry Pharmacy Coal Mining Engineer Navigation [) Assayer Iron and Steel Worker Textile Overseer or Supt. Cotton Manufacturing Woolen Manufacturing Agriculture () Fruit Growing Mechanical Draftsman Machine Shop Practice Toolmaker Patternmaker Civil Engineer Surveying and Mapping Bridge Engineer Poultry Farming Gas Engine Operating Mathematics -[) Radio BUSINESS TRAINING COURSES Business Management Business Correspondence Industrial Management Show Card and Sign Personnel Management Lettering Traffic Management Stenography and Typing Accounting and C. P. A, Lj English ching “ivil Service Cost Accounting Railway Mail Clerk Bookkeeping Mail Carrier Secretarial Work Grade School Subjects Span rench High School Subjects | Salesmanship Illustrating [() Cartooning Advertising Lumber Dealer Sahin ditt chddiientcindndsdisdndetetickannediieihgatnahddiesindininedsiesieutanes Street i caisctbvnncnaccdencettintnececccscncrttneconcceseneasenscitenecscesscesecesesenese itadeletessataneamsonadanigntencsapancscsned Rice cnapactencwtincnasosctesincsinence TEST ALES TI eccee If you reside in Canada, send this coupon to the International Correspondence Schools Canadian, Limited, Montreal, Canada aera Central ty pag eat a MONEY MAKING OPPORTUNITIES SECTION Photoplays Wanted $1250 FOR original photoplay story. Our sales department sold unknown author's first story for above amount. We revise, copyright and market stories for both silent and talking pictures. Located in the heart of motion picture industry. We know the demand. Established 1917. Free booklet. Universal Scenario am gy, y, 214 Western & Santa Monica Bldg., Holl)- we . California. Printing and Engraving FINEST Bond Letterheads 8x11, $3.95 M._ En- velopes, 95 M. Oberman Company, Box 1042, Chicago. 1000 BUSINESS Cards $2.75 Postpaid. Samples Free. John Miller, Montgomery Ave., Narberth, Pa. Printing Outfits and Supplies RINT your own cards, stationery, circulars, ad- vertising, etc. Junior Press $5.90; job presses, $11, rotary $149. Print for others; big profit. Easy rules rnished. Write for catalog presses, type, paper, etc. elsey Company, Q-3, Meriden, Conn. Salesmen and cAgents Wanted AGENTS —Clever invention! Inkspoon makes every = a fountain pen. Fast office seller, big profit, demand nereasing everywhere. Exclusive territory offered. Sample free. H. Marui Company,Tribune Bidg., New York. AGENTS. $60—$200 a week. Genuine gold letters for store windows easily applied. Free samples. Liberal offer to general agents. etallic Letter Co., 434-A. N. Clark, Chicago. A BUSINESS of your own—Making Sparkling Glass Name and Number Pilates, Checkerboards, Signs. Big Book and Sample free. E. Palmer, 513, Wooster, Ohio. CALIFORNIA perfumed beads selling like hot cakes. Agents coining money. Big profits. Catalog free. ission Factory, R 2328 W. Pico, Los Angeles, Calif, SUCCEED With Your Own Products. Make them yourself. Formulas, Processes, Trade-Secrets. All lines. ae. circulars free. C. Thaxly Co., Washington, BIG money and fast sales. Every owner buys gold initials for his auto. You charge $1.50; make $1.35. Ten orders daily easy. Write for particulars and free samples. American Monogram Co., Dept. 47, East Orange, New Jersey. .00 WEEKLY easy, applying gold Initials on Auto- mobiles: No experience needed, $1.45 profit every $1.50 job. Free Samples. “‘Ralco Monograms,”’ 1041 Wash- ington, Boston, Mass. $10 DAILY silvering mirrors, plating and refinishing lamps, reflectors, autos, beds, chandeliers by new method. Outfits furnished. Write Gunmetal Co., Ave. F, Decatur, Illinois. $12.00 DAILY Showing New Linen-Like Tablecloth. Wash like oilcloth. No laundering. Sample free. Bestever, 646 Irving Park Station, Chicago. LOID-LAC Amazing New Auto Refinishing Discovery. Not a Paint, Polish, Cleaner or Wax. Restores Colors and Finish to Old Cars im thirty minutes! Greatest Automotive Development in years. Make it yourself with my simple, Guaranteed Formula. Today's Fastest Money-maker. Write or wire for detailed exclusive offer. $50,000.00 Business for $50. Grasp today’s opportunity today! Loid Miller, Industrial Chemist, Tampa, Florida. JUST Out—New Patented Apron. No strings or straps—$20.00 a day every day; over 100% profit; com- missions daily. Write for free offer. Sta-Put Co., Dept. 908, St. Louis, Mo. GET our Free Sample Case—Toilet Articles, Flavor- ings and Specialties. Wonderfully profitable. LaDerma Co., Dept. F, St. Louis, Mo. Aucust, 1999 Salesmen and cAgents Wanted $85 WEEKLY. Amazing one-year guarant Rosecliff Shirts fast. 24 hour shipments. No subetin’ ee. Big ao ye nd ee — own shirts free, set free outfit including ties. ept. PS8, Roseclif Shirts, 1237 Broadway, New York. 5 $$ $15 DAILY selling custom quality shirts and ties Largest cash commissions, extra bonuses. Outfits free. District managers wanted. Parmode, 50 Lesser Bldg St. Louis. . NEW invention—Sells every business. Four $1 Sales daily pay $288 weekly. Adjustment Service, Dept M3, Mobile, Ala. ‘ SOMETHING new—no house to house canvassing. 4 roposition in which you can build up real business Noinvestment. Badger Co., Ft. Atkinson, Wis. : $100 WEEKLY selling all-wool union made-to. measure suits and overcoats at $23.50 and up. Build bi; repeat business. Big pay daily—monthly bonus extra. Large swatch samples FREE. W. Z. Gibson, Ine., 509 S. Throop, Dept. H-521, Chicago. STEAMSHIP positions—Men —Women. Good Experience unnecessary. List of positions free. Bey 122-X, Mount Vernon, N. Y. CARTER Window Washer. Exclusive Distributor wanted. BIG PROFITS. Cleans, Dries, Polishes, one operation. Territory closing fast. Act quick. CARTER PRODUCTS, 982% Front Street, Cleveland, Ohio, 78.00 MADE by Iowa Salesman first day New Hot Dog Machine; sells $18.50; commission $8.5 direct factory connections. Leonard E. Dickerson, Dept. R-7, Springfield, Mo. BIG Money Taking Orders for Union Label Printing. Over 1000 free cuts. Positively America’s largest print- ing stationery line. 101 standard items covering every business need such as—letterheads, noteheads, enve- lopes, billheads, business cards, statements, garage forms; shipping, battery, dry cleaner, tire, storage and hat cleaning tags; repair forms; blotters; gummed parcel post, shipping and drug stickers, ete. Lowest prices. Easy, quick sales. Repeat orders. Bigger com- missions—up to 50%! Weship everywhere. New FREE outfit. Kaeser-Blair, Dept. 136, Cincinnati, Ohio. A SPLENDID side line—we sell pass books, check covers, coin bags, etc., mainly to banks. They are cen- trally located and do business quickly. Little time is lost. Our samples are light, compact, easily carried. Sales run into money, items repeat well, commission is liberal, and all paid immediately. We also have an excellent line of advertising novelties for merchants Our quality is good, the variety extensive, the styles interesting. Line is big enough to devote your whole time if you wish. We are manufacturers, own our buildings, been in business fifteen years, make thirteen thousand sales a year, ship to every state. You could work wherever you happen to be. Correspondence in- vited. Continental Bank-Supply Co., Mexico, Missouri. Song Writers SONGWRITERS: Submit Your Song Poem or Complete Song! Will return it immediately if not accepted! Chester Escher, Music Publisher, 125 W. 45th St., New York City. SONGWRITERS: Substantial Advance Royalties are paid on publisher's acceptance. Write for Free Boo! on developing ideas for song words or music requires by canes Pictures. Newcomer Associates, 1674 Broad- way, N. Y. SONG Poem Writers—‘‘Real” proposition. Hibbeler, D10, 2104 N. Keystone, Chicago. Stamps and Coins STAMPS, 100. All different, 3 cents. P. S. Quaker Stamp Co., Toledo, Ohio. 20 VARIETIES unused free. Postage 2c. Miami Stamp Co., Toledo, O. STAMPS, 105 China, etc., 2c. Album (500 illustra- tions) 3c. Bullard, Station BB, Boston. RARE United States and foreign coins, war medals and decorations. German bill and catalogue, 10c. Alexis Mengelle, Colorado Springs, Colorado. Lists free, Pp. & “AGENTS: Bea thousand mites ahead of competition. Patented product Housewives want. Commission in advance if wanted. Vice-President, Box 929, New Orleans, Louisiana. $50 WEEKLY. Men wanted to demonstrate and take 10 orders daily direct from motorists. Amazing Magnetic Trouble Light. Sticks anywhere! More orders, bigger pay. Write for demonstrator and par- ticulars. Magno, Beacon Bldg., Dept. 46B, Boston, Mass. GOLD Leaf Window Letters and Script Signs. No experience; 500% profit; samples free. Consolidated, 60-Y, West Van Buren, Chicago. MAKE your own products. Employ agents yourself Toilet articles, soap, extracts. Ye furnish everything. Valuable book Free. National Scientific Laboratories, 1970 W. Broad, Richmond, Va. AGENTS—$250 Month. Raincoats. All colors. Your choice $2.65. Part time $2 hour. Complete line 60 patterns, silks, suedes, tweeds, Leather-Lyke. Outfit sent free, postage prepaid. Write Comer Mfg. Co., Dept. O-419, Dayton, Ohio. PUNCHBOARD Salesmen make $200.00 weekly selling punchboards and vending machines. Big repeat commissions. Beautiful 3-color catalog free. Best season now. Write today. Old reliable company, established 20 years. Lincoln Sales, 116 S. Wells, Chicago, Dept. G. CALIFORNIA gold, quarter size; 27c, $14 size; 53c. White cent and Catalogue, 10c. Norman Shultz, Salt Lake, Utah. OLD Coins, large Spring selling catalog of coins for sale free to collectors only. Catalog quoting prices paid for coins, ten cents. William Hesslein, 101B Tremont St., Boston, Mass. $10.00 FOR 25c. A choice assortment of 500 all differ- ent stamps guaranteed to catalogue over $10.00, offered to approval applicants for only 25c. Edgewood Stamp Co., Dept. S, Milford, Conn. Stories Wanted BIG demand for Photoplay, Talking Picture and Magazine Stories. We revise, develop and copyright. Sell on commission. Established 1917.- Booklet free. Universal Scenario Company, 414 Western & Santa Monica Building, Hollywood, California. Telegraphy TELEGRAPHY—Both Morse and Wireless—taught thoroughly, quickly. Big salaries. Wonderful opportu- nities. Expenses low: chance to earn part. ool established fifty years. Catalog free. Dodge's Institute, Hart Ave., Valparaiso, Ind. SCREW-HOLDING screw driver! Sells $1.50. Fac- tories, garages, mechanics, electricians, radio buy on sight! ixclusive territory; free trial offer! Jiffy 1117 Winthrop Bldg., Boston. AGENTS Wanted to introduce fast-selling personal necessity and distribute free ane. $1.25 an hour easy. Particulars free. Albert Mills, 3782 Monmouth, Cincinnati, O. Typewriters and Supplies TYPEWRITERS—Factory Rebuilt Royals, Reming- tons, Underwoods. New Royal, Remington and Corona Portables. New “Excellograph” Rotary Stencil Duplica- tor $37.50. Terms. Catalogue Free. Pittsburgh Type _wWriter Supply, Department 543, Pittsburgh, Pa. omnes sak

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IST, 1929 red ae ‘antee 0 substing shirts free, 3, Roseclity ——_____ S and ties, ut fits free. sser Bldg, a ur $15 sales Dept. M-3, 1 2Vass! Te ng. A Vis. : >i stribu lahes, on eo. E , Ohio, - day sion $8., Dickerson, l Printing. gest pene: ering every ads, enve- ts, garage torage and ; gummed Cc. Lowest ‘igger com- mission is > have an nerchants. the styles our whole wn Missouri. LT Poem or ly if not , 125 W. valties are e Booklet id Broad. Hibbeler, ists free, 2. Pw & ) illustra- ar medals gue, 10c. size; 53¢. ultz, Salt nont St., all differ- 0, offered dd Stamp | ee Avucust, 1929 Dollars Your Car Can Save You (Continued from page 84) so what I spend at the club ought to be charged inst the car—and, believe me, it’s plenty! That car doesn’t do anything else but take us to places where we can spend money!” “H’m,” grunted Joe. “You seem to make out a case. What have you got to say, Ted, for our side of the argument?” “Well,” Ted began, “I drive about as many miles as Mac does, so I guess the four-hundred- and-eighty-dollar figure fits me, too, but the car saves money in lots of ways.” “‘As for instance?’’ questioned Joe, jiggling his pencil. “Qn vacations, for one thing,’ Ted ex- plained. “If you want to put down some , you can start with exactly fifty-six dollars and eighty cents railroad fare we saved last summer. That’s what the tickets for the wife, the two kids, and myself would have cost on my vacation. Then you can put down at least four dollars more that we saved on ex- pressage by carrying our baggage in the car. Also, because we had the car and didn’t have to hang around the hetel all the time, we were satisfied with a cheaper hotel farther from the beach. That saved at least twenty dollars on the hotel bill. And we found a beach where we could conveniently get into our bathing suits in the car. Every time we did it we saved just one-fifty in bath house fees. Figure all that up for a two weeks’ vacation! This year we're going motor camping for our vacation and we'll save still more.” “apaATs nearly a fifth of your car expense already offset by saving,’ Joe commented. “How do you account for the rest?”’ “It’s kind of hard to give definite figures,”’ Ted said slowly. “It’s principally in getting our fun out of the car instead of spending money on more expensive amusements. Nearly every clear Sunday we go off on a picnic in the car. That doesn’t cost us anything but the food, and the wife says it’s cheaper to get up a picnic than to cook Sunday dinner. Then, since we've got the picnic to look forward to on Sunday, we don’t bother to go to the movies on Saturday night as we used to before we got the car. The savings that way ought to come to quite a respectable total during the course of a year. ‘Before we got the car I used to hang out with a bunch of fellows from the office Saturday afternoons. Usually we went to a matinee, or shot some pool or something, and what with one thing and another I generally spent at least three or four dollars. Now I head for home right after the office closes, have a bite to eat at home, and we go for a ride; or, if the wife is busy, I spend the afternoon washing and polishing the car.” Dk pencil was busy for a few minutes. “By Jinks!” he exclaimed. “‘Looks to me as though you'd come pretty close to justifying the entire car expense.” “Tf I haven't,” Ted grinned, “‘you can put down a little something for doctor’s bills saved. I’ve noticed that we don’t have to call in the doctor quite so often now that we spend more time outdoors.” “Well,” observed Joe, “far as I can see, you're both right in this argument. Each one of you is looking at it from a different view- point. It only goes to show that a car will help you to spend money if you're inclined that vay or it will help you to save money if you'll et it!”’ HAYE you a motor car problem that needs solving? Let Gus and Joe answer it. Write to Mr. Bunn in care of POPULAR SCIENCE MONTHLY, 250 Fourth Avenue, New York City. MONEY MAKING OPPORTUNITIES SECTION 129 Pick the RADIO Job you want... and fill it in only months Read This Thrilling Free Book It gives you the real “dope” about Radio and describes in detail the famous training that has enabled us to place thousands of our students in fine positions, usually from 3 to 10 days after graduation, It may mean the turning point in your life. It tells in 50 fascinating pages and photos all about Radio’s brilliant opportunities for adven- ture and success. Mail the coupon now — the book is absolutely free ! Radio Institute of America, Dept. P.S.-8 326 Broadway, New Yor! A > By means of this“ Big-League” home-training sponsored by Radio Corporation of America WE struggle along on less than $45 a week? Why wait years for success that can be yours in only 9 months? As a result of a marvelous new kind of home-study training in Radio, hundreds of men are today leading straight for fi- nancial independence! Radio pays from $2,000 to $25,000 a year. The work is thrill- ing...the hours are short. Vacations with pay... opportunities for seeing the world ee. adventure galore! Prepare at Home with this Big Laboratory Outfit Get the “How” as well as the “Why” of Radio—with this expert training! Only an hour or so a day—in spare time—is all you need! As part of your course, you receive absolutely free of extra e—a magnificent outlay of apparatus. With this outfit you learn to build fine sets and solve the problems that bring big pay. Training sponsored by Radio Corporation of America Our graduates are in big demand every- where. They enjoy greater success because they’re posted right up-to-the-minute in everythingin Radio. Radio’s progress each year is measured by the accomplishment of the great engineers at work in the re- search Siannuie of RCA. This great organization sets the standards for the in- dustry, and stands back of every lesson in the course. : Money Back if Not Satisfied The lessons prepare you for success in all phases of Radio—manufacturing, servic- ing, selling, ship and shore broadcasting, Television and Photoradiograms. A signed agreement backed by RCA assures you of complete satisfaction upon completion of the training—or your money will be promptly refunded. Dept. P.S.-8 home. Name Radio Institute of America 326 Broadway, New York, N. Y. Gentlemen: Please send me your big FREE 50-page book which tells about the brilliant o famous laboratory-meth nities in Radio and about your of,guaranteed radio instruction at Add é

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130 MONEY MAKING OPPORTUNITIES SECTION A RAILWAY

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YOU CAN MAKE $50 A DAY WITHOUT SELLING! If you are ambitious and want to build a big, profitable and permanent business that is all your own—this is your opportunity. We need men to act as my exclusive distributors for Blue Ribbon Chewing Gum—the new, highest qual- ity and delicious chewing gum sold only through Blue Ribbon automatic machines. You will place these marvelous machines in good locations in your territo You have only to keep your machines sup- plied with Blue Ribbon gum and take out your money. Our sensational premium plan guarantees big profits from every one of your machines. We take all the risk to prove to you that you can make $50 every day in this profitable business. You don’t have to gamble a penny of your own money Reserve your territory now rite TODAY for re particulars. BLUE RIBBON GUM CO., Inc. 395 Broadway, Dept. 67, New York City Learn Cartooning Home—in The famous Picture ChartMethod of teaching original drawing bas the door of success for —~s jhether y — you have talent or not, oxnd ig sam to test your abil- oe of the work of its earning $50 to $300 bees Please state your age. E LANDON SCHOOL 145). National Bidg., Cleveland, 0

Reese— A Man Who Always Does the Impossible (Continued from page $2) We discovered it just as you said we would.” “Good work!” exclaimed Dr. Reese. “I knew you'd succeed.” The other had scarcely finished telling how the result had been arrived at when Dr. Reese's telephone rang. “TI called you to say that we've found out how to make diphenylamine.”’ It was the voice of the chief chemist of the other laboratory! “Both of them found the secret,” Dr. Reese told me, “‘and we did not lose a day on our British contract. “And that experience proved what I had long maintained—that the time had come for America to declare its chemical independence of Europe. “To make diphenylamine we had to get into the aniline business ourselves. Now was the time to lay the foundation, at least, for an American aniline and dye industry.” He got the backing he asked for to do precisely that, and as a result of the new markets created for their services there are more American chemists employed in industrial research today than in all the rest of the world put together. iv HE had never done anything more than that Dr. Reese's name would always stand high in the annals of America. But that is only a small part of his achievement. Another war victory, for example. High explosives, of which trinitrotoluene (T.N.T.) is the most famous, came to play a greater and increasing part in the war. Here, again, America and the rest of the world were de- pendent upon Germany. Toluene, the essential substance of T.N.T., is another product of coal tar. The’ formula in this instance was no secret, but there wasn’t enough toluene being produced in America to supply anything like the war demand of the Allies, let alone our own probable requirements should we get into the conflict. Dr. Reese, already deep in the aniline business, knew the whereabouts of every ounce of toluene, knew precisely what facilities existed for its production, knew just what would have to be done and how long it would take to produce more. And it all added up to less than enough. What was needed was a new way of making toluene. So again Reese called in his chemical right-hand men. “We ought to be able to build up toluene out of benzene,”’ he told one group. “‘See what you can do.” To the other group he said: “See if you can find a way to break down xylene into toluene.”’ ‘THE result was a repetitioh of the former effort. Both laboratories found ways to make toluene. What proved of even greater importance, one of them developed a new sub- stance, xylol, which proved of even greater value than toluol, so that when the United States went into the war we loaded our depth bombs and high explosive shells with trinitro- xylol—T.N.X. Those two war incidents illustrate the method by which scientific research in industry is done. Teamwork, organization, a definite problem stated; perhaps a suggestion as to how it may be solved. That is the method estab- lished by Dr. Reese, and now adopted in every great research laboratory. It is a method which demands from the man at the head of the research organization, not only a thorough knowledge of science, but a thorough under- standing of its economic relations and the ability to organize and train a staff of scientists and get the most out of them. “Like a school-teacher setting problems for his classes to solve,” I suggested. Dr. Reese, tall, erect, with pince-nez astride his nose, reminded me of more (Continued on page 131) Aucust, 1929 BOOK ON

FREE Send your name and address toda i amazing new book. It tells anes nws thet bi iH money and startling opportunities in A /@ thrilling new field and how you ualif: ity for a real job in this fascinatin; ting industry Learn at Home Find out all about the sudden demand for daring young men in Aviation, and how can now secure the basic fundamen tion, at home > oe gh ) yj startlin; Opportunit 7 / the Airplane ndustry. No obligation. a f AMERICAN SCHOOL OF AVIATION 3601 Michigan Ave., Dept. 137.c, Chicago, tit, weeos PLUMBERS Old style plumbers are fading like the horseand buggy. The world de- mands modern Plumbing and Skilled Trained Mechanics todoit. Unlim- ited, swift growing field. ee to $100 a week or start own train you quick. Learn in 8-12 Wis todo any job with skilland science. Need no previous experience. Strictly toolus- ing system. Opportunity knocks. Inves- tigate teday—amazing offer—low tuition. orld’s greatest school. Write— UNIVERSAL PLUMBING SCHOOL 2131 TroostAve. Kansas City, Mo.

urse for men of ambi- Electrica et ~ hE Over 5000 men trained. Condensed course in Theoretical and Practical Elec- including trical Engineering the — subjects of Mathematics and Mechanical | by Students construct motors, install wiring, test elec- trical machinery. Course designed to be completed one college year. BLISS ELECTRICAL SCHOOL Prepare for your fecteattes in the most interesting ¢ iy in the world. talog on request. 108 Takoma Ave., Washington, D.C. <n REEREPERENESRESS npHERSRE “STAMMERING| Ifs Guse and Gre * You can be quickly cured if you Stammer. Send 10 cents, coin or stamps, for 288-page cloth bound book * Stammering and Stuttering. It tells how I cured

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929 dp es OA Zz ro now, and rms, ie to J| roel eran ate oie 2st EDS a: al lie ical sil tes. en Aveust, 1929 That’s the way we teach and we do more—we give the student a thorough training which will insure his success in after life. No field offers such great possibilities to ambitious men as the ELECTRICAL FIELD. You must however be practically trained before you can reach the harvest of your knowledge. We teach you electricity by giving you the actual work todo * Every branch of Practical Electricity is so thoroughly and so personally taught as to place one who graduates from our school several years ahead of the experienced man in the field who has not had special training such as we give. Write for our Free Booklet today, or call at the school and get full par- ticulars. School open all year. THE NEW YORK ELECTRICAL SCHOOL %40 West 17th Street, New York i Account aiT Executive Accountants oc 34 Cty ~ OOO eutio Account: tes. we a. you Choro! at home in spare eee A. reais or executive a tora a Frevious experience an unnecessary. supervision o Cas A. a large “staft of C. pf y ranch i Tmermbgre of ths America Institute of — | | | | | | Ui i ie — ll ued irlte for for free Extens versity, Dept.883-H. Chicago The Extension Uni actnnce Tress = g institution SCIENCE NEW S* LETTER [eyce enjoy a weekty | that sparkles from cover to cover, see th ine. The light reader is charmed b its delig htful enter- e qualities. The thtoker is rewarded with the very latest ane | most valuable news in every branch of scien Introductory a. “1 Sor 13 weeks 2151 B St., N. W. Washington, D.C. bo oye Ft dy Bt. Ican ou at home during spare time. Write for my ER Fate’sook," “Mow to Become a Good P. and tells how others maste: a Denmanebip ny wr the Tamblyn System. Your name will be elegantly written on a card if 700 enclose stamp to pay postege. Write to- day fo. FW. TAMBLYN, Kane Gg Bd S.A. AGENTS 500% PROFIT GENUINE GOLD LEAF LETTERS Guaranteed to never tarnish. Anyone can ut them on stores and “ffice windows normous demand, large protits, Paul Clark says: smallest day $28.70. R.L. Reel made $920 in two months. | Write cae for free sample and liberal offer to general agents. METALLIC LETTER CO., 433A N. Clark Street, Chicage. Ecration ad vist fats tbe Jay Lag iahed choot. Succougful eradusten © No sbligs: ae PAGE-DAVIS SCHOOL OF “ADVERTISING Dept.136-c 3601 Michigan Ave., Chicago, U. S.A. Reese—A Man Who Always Does the Impossible (Continued from page 130) than one of the teachers of my own youth. He smiled at my suggestion. “‘Of course,” he said; “it’s merely an exten- sion of my life work, teaching chemistry, into the field of industry. I’ve been teaching chemistry ever since I got through going to college myself. I was brought up in an atmosphere of chemicals. I can’t remember when I wasn’t interested in the subject.” Dr. Reese’s father had been a dr-ggist, in the days before the Civil War when the more familiar sign on a drug store front was “Chemist.’’ An uncle was also an apothecary; another uncle and a grandfather were phy- sicians. “T never lost my interest, even as a boy, in trying to find out what different things were made of,’’ Dr. Reese told me. “I remember picking up a piece of stone in a field near Baltimore, observing that it was composed of several different kinds of stone fused together, and spending a great deal of time and study trying to discover how it got that way.’ BORN in Baltimore in 1862, young Reese’s early surroundings were those of literary and artistic culture supported by modest wealth. He was not yet twenty-two when he graduated from the University of Virginia, with his enthusiasm for chemistry heightened by the work he did there. Then he went to Germany, to famous Heidelberg, to study more chemistry, and returned with a Ph.D. degree to his home city to become an instructor in chemistry in the young Johns Hopkins Univer- sity. “*T didn’t have any idea at that time of ever doing anything except teach chemistry,”’ Dr. Reese told me. “‘If I had told anyone nae I expected some day to organize chemical laboratories for industrial concerns I would have been laughed at. Science and industry were far apart as the poles, at least so all industrialists and most scientists believed.” So from teaching chemistry at Johns Hop- kins he went on teaching chemistry, as profes- sor of that science, at Wake Forest College in North Carolina and the South Carolina Military Academy, until 1896, when he went back to Johns Hopkins and taught chemistry until 1900. wi the turn of the century business began to be done on bigger and broader lines than before, business men began to slough off some of their contempt for “‘college men,’ university professors began to realize that America is, after all, a business nation, first and last, and that there is nothing incompatible with culture in the effort to improve business. The New Jersey Zinc Company had a prob- lem to solve—how to make sulphuric acid more economically. Looking for a chemist to solve it, they picked Dr. Reese. He found the way. It may not mean much to the man in the street to learn that someone has found a new way to make sulphuric acid, but that substance is the most important chemical in all industry, even more important, probably, than alcohol. So although Reese’s new process didn’t get him any headlines in the newspapers, it made a real sensation in industry. Business heads began to ask the identity of the young man who had found the revolutionary process. When it was disclosed that he was merely a college professor, most of the curious ones just laughed. But Eugene du Pont, then president of E. I. du Pont de Nemours & Company, asked Dr. Reese to come and see him. Perhaps a univer- sity-trained chemist could find out some inter- esting things about explosives. Their meeting was the beginning of the new era in American industrialism. Dr. Reese proposed that the Du Ponts establish a research (Continued on page 132) MONEY MAKING OPPORTUNITIES SECTION | 131 who want facts on the Jobs now open in Radio You will find a true picture of iftio’s many opportunities es in this book. lis you waere © . Wiceie sens are + ak they pay. how ou are time to get one. The den mand for well: trained men is far greater than the supply. Many start at two and three times their old ontemes ; 4202 Arsenal St., 8t. is, 13. ‘rent from, § $35 A 0 $100 9 ee at. 7 Bait Lake cits City, Yah. ea Kes ver E. Sait Lake mere 4 fore. The $50 to 3 ry wail jobs “hat opening now will in many cases lead quic to $100 to $150 a week. = course that pays mee — e day you enroll I will s wore sto make money doing ‘2 yor to ‘ found in every ry neigh ll you how sca pe ihe cee Ge cnarege. Nashville, fenn., m ade’ $935 in his spare time hile studying. 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This Free Book is —if you write for it and indicate th plan (by number) thet interests you. is Actress; SUE Ftd, Stvcaey,Jucwngas, cousee Reese—A Man Who Does the Impossible (Continued from page 1.31) laboratory on purely scientific lines, as was done in Germany. “That was almost the first, if not the first, really scientific industrial research laboratory in America,” he told me. “The General Electric Company had begun some research work in a small way about the same time, 1902, but that is the only instance I know of which compares with what I was privileged to inaugurate for the Du Ponts.” One laboratory grew into five. The prob- lems of explosives were solved, and the by- products of the explosive business began to compare in value with the explosives them- selves. For the chemical laboratories were finding ways to make the same raw materials which entered into the manufacture of smoke- less powder into a thousand other things. Nitric acid, sulphuric acid, and_ cellulose are the basic chemicals in the manufacture of modern explosives. Before the European War the laboratories under Dr. Reese's direc- tion had developed ways of using those and a few other substances for the manufacture of artificial leather, artificial ivory, or pyralin; and other products. The war slowed down activ- ities in these fields, but opened up others. NE was the development of a method of extracting nitrogen from the air. Chile nitrates had been the world’s only large source of fixed nitrogen when the war began. Ger- many had a process of fixing atmospheric nitrogen; so had Norway, and so, in a still semiexperimental way, had America. Dr. Reese set his chemists to work to study all of these and all other possible methods of fixing nitrogen. ** Almost the commonest of all the elements, nitrogen is the most difficult to capture and the hardest to keep in captivity,” said Dr. Reese. ‘It is the basis of all explosives, because of that intense desire to set itself free. It is also the essential element of plant food without which vegetation wi!l not grow. So long as the rest of the world was dependent upon Chile, where there are vast natural deposits of nitrate of soda, progress in the manufacture of fertilizers and of the industrial products which are based upon nitrocellulose was bound to be limited, while in time of war a powerful enemy might shut off this source of supply completely. *“We began experiments in the fixation of atmospheric nitrogen during the war. The process originated by Georges Claude, the great French scientist, seemed to offer the greatest possibilities. That has led us into the field of physics as well as of chemistry, for in our ammonia works in West Virginia we deal with pressures as high as 15,000 pounds to the square inch. That pressure is necessary to induce the nitrogen of the air to combine with hydrogen extracted from water into synthetic ammonia. Here is an inexhaustible supply of raw materials—water and air.” HILE nitrates are still imported, mainly for use in fertilizers, but practically all ex- plosives made in America today, as well as most of the fixed nitrogen used in other indus- tries, come directly from the air. What has happened in the United States in the martufacture of dyes is a matter almost of common knowledge. Dr. Reese pointed the way. Today we live in a world which is almost a riot of color because of the great volume of cheaply-produced dyes made in America. After the war Dr. Reese's attention turned to other possible applications in industry of the two chemical substances which formed the base of the explosives business—nitric acid and cellulose. Out of the research he directed came a dozen more revolutionary inventions and applications of chemistry to industry. Artificial silk, all of which is now known under the general trade term of “rayon,” wag being made in Europe before the war; a num. ber of American companies were formed after the war to manufacture it in America. And artificial silk is actually nothing but nitro. cellulose. Dr. Reese's initiative in research developed a process of making rayon from wood pulp instead of from nitrated cotton. The method is different from the others; the end-product is the same. Another universally-used product of the chemistry of nitric acid and cellulose is the artificial ivory once known only as “celluloid” and now by a dozen other names invented by their respective makers. The most spectacular and revolutionary of all these postwar results of Dr. Reese’s re search work, however, is pyroxylin lacquer, the new quick-drying surface covering, taking the place of both paint and varnish, and now universally used as a finish for automobiles and many other articles. “FIYHE pyroxylin lacquer was a development of our pyralin business,’ Dr. Reese related, “We had been making for several years a thin, transparent lacquer for protecting bright brass work and the like against tarnishing. One of our agents in California had been having trouble with the finish of his car, which required repainting or revarnishing every few months. It occurred to him that this lacquer might serve as a better protection of the paint against the weather. He tried it, found it fairly satisfac- tory, and got some others to try it. “He reported his experiment, and we began to study the problem in the laboratories. It was not enough, however, to make merely a varnish. If we could produce a heavy-bodied pigmented enamel which would take the place of either paint or varnish we thought it might have some commercial value. ‘The development of the lacquer was purely a chemical laboratory affair. Everybody today is familiar with the revolution it has brought about in only three or four years in the auto- mobile industry. It has made it possible to finish automobiles in a wide variety of colors, reduced the upkeep by eliminating frequent repaintings, cut down the cost of making cars by reducing the time they must spend in the paint shops, and has eliminated the immense storage space formerly required while the paint was drying.” HE discovery came just in time, Dr. Reese pointed out. The world’s supply of high- grade resins is dwindling and resins are the basis of the old varnishes and enamel paints. Now cellulose takes the place of resin and the supply of cellulose is illimitable. “*We don’t wear as much cotton as we used to, in the form of cotton, but we use more cotton in other forms than ever before,’’ he said. “Rayon, pyroxylin enamels, artificial leathers, motion picture films, all of the plastic materials coming under the general head of ‘celluloid’ and its similar substances, as well as a large proportion of all of the explosives used in industry, are made of nitrated cotton— nitrocellulose. ** And don’t overlook the fact that explosives are even more important in peace than in war. All modern industry is based on the use of ex- plosives. We couldn’t build skyscrapers with- out using explosives to blast out the iron and the coal; we can’t dig canals or railroad tun- nels without explosives; in New York you can't excavate the foundations for a house without explosives. Farmers use explosives to clear land, to dig drainage ditches. You can’t imagine building the new Boulder Dam without using explosives.” “What is going to (Continued on page 133) Aucusr, 1999

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” ial hum. ! after And nitro. ped a pulp hod is uct is f the s the loid” ed by ry of quer, aking now s and ment thin, brass ne of ing aths. serve t the sfac- egan — ly a died lace ight rely day ight uto- > to ors, 1ent cars the 2int ese gh- the nts. the sed ore he ial stic as sed ves ar. PX- th- nd in- ou ise pu 3) Aveust, 1929 MONEY MAKING OPPORTUNITIES SECTION — | Ty Reese—A Man Who Always Does the Impossible (Continued from page 132) happen next in chemical industry?’’ I asked. “God only knows!” exclaimed Dr. Reese. “Whatever it is, it will probably change a few more industries from their present lines to new ones. That is what every new discovery and invention does. ¥. “Qne great American industry had to reor- ganize its entire business when the modern high-power incandescent lamp displaced the old-fashioned arc lights on the streets; its busi- ness was supplying carbons for the arcs. If it had not been fcr the scientific research workers whom it called in, that company might have failed. Instead, its scientists found new ap- plications of its supply of raw materials, which have made it greater and richer than its founders ever dreamed. a weed is what is going on in American industry today. What industry needs is more research in pure science. Industry is using up available scientific knowledge so rapidly that it won't be long before every scientific fact ever discovered will be utilized for the benefit of all humanity. We need more knowledge, more facts scientifically proved merely because they are facts. Farseeing men in industry today realize that no knowledge is worthless, whether or not it seems to have any immediate bearing on business. Some day, in some way, every new truth finds its application in industry.” Lining the Rooms of Your House (Continued from page 75) ever notice that when you are standing on a hill and looking at a view you don't take in the beauties of the things near by? In a room everything is in the foreground, and you shouldn’t make the background of walls so distracting as to claim attention. Think of the walls only as the background for the furniture and fittings, and you'll get the idea. What I say about the walls goes for the trim, too.” “Trim? What's that?” “The doors and the frames around the doors and windows that cover the edges of the plastering. You might say that the trim is all of the woodwork except the floors. It goes a long way toward giving a room its character. Fifteen years ago I'd have had to design it all for you and have it specially made, because the stock patterns of the sash-and-door mills were pretty nearly impossible. But now their de- signs are made by crack architects, and you can get stock doors and frames, stairs, porches, and everything else that you'll be proud to use. And there are machine-made moldings that are such perfect copies of handwork that they'd fool anybody. You can even duplicate the beautiful woodwork of the early New England — and at only part of the cost of hand- work. “@UPPOSE I make some sketches of the dining room and library and living room. They'll be something to start with, and we can change them around to get what you want. ‘And while your wife is working on that part of it,” he went on, turning to Mr. Kersey, “you've got a real job ahead of you. We can’t go much further without deciding on how the house is to be heated, and that'll be up to you. Here's a list of makers of heating plants. Show them the house plans and ask them for recom- mendations, and when you've heard what they have to say, you'll have a pretty fair idea of what to do about it.” Mr. Whitman’s next article gives val- uable advice on selecting the right heat- ing plant for the home you plan to build. VICTOR BUILDING Our New Building Nearl Patent Office Special Us for Our Own Use \Y by experienced Patent Lawyers and Draftsmen. t ; answer any questions in regard to Patents, Trademarks or Copyrights without charge. FOR THE PROTECTION OUR OFFE ; OF YOUR INVENTION YOUR FIRST STEP—The inventor should write for our blank form “RECORD OF INVENTION.” Before disclosing your invention, a sketch and description should be made on our “Record of Invention Blank”, signed, witnessed, then re- turned to us and we will place it in our fireproof secret files. We will also give our opinion as to whether the invention comes within the Patent Office definition of a patentable in- vention. 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Learn to Fly with Larry Brent (Continued from page 46) made so dizzy by the first spin that they helplessly put their ships into reverse spins, and continue doing this until the whirling dulls their minds beyond any usefulness and—oh, well. I have heard of pilots holding ships in spins for 5,000 and 6,000 feet, and pulling them out. I'll believe those stories when I see it done! If any flyer has ever made a spin of more than 2,500 feet and pulled out of it without falling off into a reverse spin, I would like to hear about it—with verification. In that reverse spin of mine, I did what I had been told to do—what I had practiced with a broom handle, night after night, as I sat.on my bed. I pushed the stick forward and kicked the rudder against the spin. I have since wondered what was in Randy’s mind dur- ing that spin. Was he grinning, as he usually did, when I got myself into a tight corner, or did he have that pyrene can in his hand, ready to reach back and let me have it? We snapped out of the spin into a vertical dive. .This time I was steadier. I pulled out slowly. I found my horizon, and although it was going past like water squirting out of a — I held the nose steady and kept the wings evel. ; Enslow looked back at me. Then he grinned. Below my goggles I must have been the color of an unripe lemon. I had never had such a scare, never gone through such a sickening physical experience. He took the controls. Back of the Month’s News (Continued from page 51) veloped. Shortly afterwards, antisnake-bite serums were also evolved in laboratories in Brazil and in this country. Because it is extremely irritable, the rattle- snake is the greatest offender among many poisonous snakes in the United States. The rustle of wind in the leaves or even a distant glimpse of a man will excite its fear and arouse its defensive fury. Experts are not certain whether it must vibrate the tip of its tail be- fore it can strike, but agree that it never strikes without warning. Any sound will cause the rattler to coil itself into a spiral. According to Dr. Calmette, it lifts its head eight or ten inches after coiling. At the same time, the tail goes up and begins its rattling. In this posi- tion the snake remains, ready to strike, as long as it believes itself menaced. Whenever you hear the rattling noise, ex- perts advise, stop dead in your tracks. Don’t make the slightest motion. If you do, the rattlesnake will strike. If you don’t it forgets all about you, uncoils and gees away. Spending Millions for War on Mosquitoes HE other day, Dr. A. S. Barrett, chief of the Milwaukee Public Museum expedition to East Africa, returned with thrilling tales of high adventure in the jungle. The explorer told of shooting a charging rhinoceros at a distance of only twenty feet and of killing other wild beasts in self-defense. But he and his party agreed that of all the creatures that menace man on the Dark Continent the most ferocious is—the mosquito! Emerging from jungle swamps in swarms of millions, the insects descended nightly upon the helpless men, robbing them of sleep and even endangering their lives. All means of combating the pests proved unavailing. Small wonder that the tortured travelers preferred the attacks of animals they could fight with gun and hunting knife. One doesn’t have to go to Africa, however, to learn that the mosquito is one of the most nl When we touched ground, a few minutes later, in the gentlest of three-point landings, I would not have given a dime for the entire airplane industry. I sat down on the low rail fence near the “lighthouse’’ on the line and tried to convince my stomach that it was all over. I informed it that we were never going up in an airplane again. ‘*We’’ were through. I went over to the field restaurant and drank a cup of hot black coffee. That helped. But it took an hour for that awful physical depression to go away. No, I didn’t lose my breakfast. And presently I decided that [ would, after all, keep on and fulfill my ambi- tion to become an air mail pilot. Two hours later I went up again with Enslow for my regular daily lesson. I made some fair landings. Enslow grinned, gave my shoulder a fatherly slap, and said: ‘Don’t worry, kid. You're going to make a flyer.’’ Next week, I’ve decided, we'll go up for some more spins. But I know I will never like spins. Some day, years from now, with five or ten thousand hours behind me, when someone asks me if I like spins, I know I will give them the same dull, vague look with which Randy answers foolish questions. Next month Larry will tell of other thrilling adventures that will make you tingle with the excitement of learning to be a pilot. cruel enemies of mankind. Scientists have cal- culated that in the United States 7,283 gallons of human blood—the equivalent of the total vital fluid of more than 3,750 adult persons— is sacrificed each year to mosquitoes. On a “battle front”’ stretching from Maine to Florida, thousands of men are engaged each year in a battle to exterminate the pests, and millions of dollars are spent. The weapons include ditch-digging tanks, rotary oil-sprays, power pumps, tide-gates, gasoline engines, and electric dynamos. These are used to drain swamps where mosquitoes breed, or spread oil on waters that cannot be drained, to kill their larvee or “wrigglers.”’ MOoOsau Toes breed both in salt and in fresh water. The killifish or salt minnow is the great natural enemy of the immature salt marsh mosquito. Hence, 140,000 acres of salt marsh in metropolitan New Jersey and the sea- shore resort region have been trenched with some 40,000,000 feet of narrow ditching in such a way as to cause the water upon them to rise and fall with the tides, thus affording passage- ways for man’s ally—the killifish! In the New Jersey salt marshes it has been found necessary to fence out the tide with dikes! From these diked areas the water is re- moved by gravity through tide gates. Where the marsh is too low, the water is pumped out. The huge drainage pumps used in this proc- ess draw 2,800 gallons of water from fhe marsh per minute. And as examination has shown that there are about 400 eggs, larvee or “wrig- glers’’ to each surface gallon of marsh water, each of the machines is responsible for the destruction of 1,120,000 potential pests per minute. Maintaining that average and work- ing day and night, one pump would kill 67,- 200,000 in an hour, 1,612,800,000 per day, and 11,289,600,000 a week! How necessary is such wholesale destruction becomes apparent when you realize that one mosquito breeds 159,875,000,000 offspring a year! However, “only’’ half of that number, or 79,937,500,000, are females which do the

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inutes dings, entire W rail e and as all going ough. , and ysical e my hat [ ambi- with made em we p for r like 1 five when [ will vhich ther you ning > cal- llons total ns— laine each ests, pons rays, and [rain read kill 1 in now salt salt sea- with such rise age- een vith ; re- here out. roc- ursh wn rig- ter, the per rk- 67,- and ion one y a er, the orate ls 5 li Aveust, 1929 People in the Public Eye (Continued from page 30) delphia Centennial Exposition at $2.50 a day. He is Gustav Lindenthal, who was 79 years old jn May and says he expects to cross his beloved Hudson Bridge. In robust health, his nearly six-foot figure erect and an athlete one of whose pet hobbies still is boxing, there seems to be no reason why this expectation should not be fulfilled. The chief engineer of the North River Bridge Company, who has planned more bridges and tunnels than any other man in the United States and is doubtless the greatest bridge builder in this country, arrived in America in July, 1874, when he was twenty- four years old. He stayed in New York just long enough to catch the next ferry for Jersey City, where he boarded a train for Philadelphia. Carefully tucked away in an inside pocket was a purse containing $200—all he owned in this world. Friends in Europe had been so em- phatic in their warnings against the thieves and pickpockets of New York City that he didn’t dare to remain there for the length of time it would have taken to eat a sandwich! The previous year, he had visited the In- ternational Exhibition in Vienna, Austria. This had given him the idea that Philadelphia, which was them preparing the Centennial Ex- position, was the right place for a young, ambi- tious draftsman. So he resigned a good po- sition as division engineer on the construc- tion of one of the Swiss railroad approaches to the St. Gotthard Tunnel through the Alps, which he had held since finishing his technical studies in Briinn, his birthplace, and Vienna. In his vacations he had worked as a carpenter, an apprentice in a machine shop, and as a mason. EACHING Philadelphia, he realized he picked a poor time to migrate to the New World. As a result of the panic of 1873, there was wide-spread unemployment in the United States. He had no letters of introduction. He trudged from office to office, but no engineer or architect would employ him. Weeks passed. His $200 dwindled alarmingly. Then he took a drastic step. He invested $9 in a set of secondhand mason’s tools and took them out to the Centennial grounds in Fairmount Park. Here he found a foreman who spoke “Pennsylvania Dutch.’’ The man was super- vising a gang of laborers digging a hole. “You stand over there,” he told young Lindenthal, pointing to a group of waiting, jobless masons. “When I raise my hand, you come. He raised his hand on the fourth day! By that time, the digging was finished. Despite the rush, Lindenthal was among the first in the ditch, the site of Memorial Hall, one of the Centennial’s permanent buildings which still stands in Fairmount Park. The Austrian stone mason gave such striking evidence of possessing ideas that his background and education were soon dis- covered and it was but a few weeks before he was given a draftsman’s job. After that, he was quickly promoted to the post of chief of the office where all of the wrought-iron work for the Exposition was designed. __The year 1877 saw Lindenthal established in Pittsburgh as a consulting engineer, spe- cializing in building railroad bridges and tun- nels. From 1879 until 1881, he was bridge engineer for the Atlantic and Great Western Railroad, now part of the Erie system. During that time he replaced a large number of wooden Howe truss bridges with iron structures for heavy locomotives. As chief engineer for sev- eral railroads between 1882 and 1890, he built many railroad and other bridges in Penn- sylvania, Ohio, West Virginia, Illinois, and Indiana. He received the Rowland medal from the American Society of Civil Engineers in 1883 for his Monon- (Continued on page 136) — MY PATENT LAW OFFICES OPPOSITE U.S- PATENT MONEY MAKING OPPORTUNITIES SECTION 135 ~~ “Wyrite for these FREE BOOKS/ At the left is a view of my drafting and_ speci- fication offices where a large staff of experienced experts is in my constant employ. All drawings and specifications are pre- pared under my personal supervision. Protect Your Ideas Take the First Step Today If you have a useful, practical, novel idea for any new article or for an improvement on an old one, you should communicate with a competent Registered Patent Attorney AT ONCE. Every year thousands of applications for patents are filed in the U. S. Patent Office. Frequently two or more applications are made for the same or sub- stantially the same idea (even though the inventors may live in different sections of the country and be entirely unknown to one another). n such a case, the burden of proof rests upon the last application filed. Delays of even a few days in filing the application sometimes mean the loss of a patent. So lose no time. Get in touch with me at once by mailing the coupon below. Prompt— Careful Efficient Service This large, experienced organization devotes its entire time and attention to patent and trademark cases. Our offices are directly across the street from the U. 8. Patent Office. We understand the technicalities of patent law. We know the rules and requirements We can proceed in the quickest, safest and best ways in preparing an application for a patent covering your idea. Our success has been built on the strength of careful, efficient, satis- factory service to inventors and trademark owners located in every of the Patent Office. state in the Union. Strict Secrecy Preserved— 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. It is probable that I can help you. Highest references. But FIRST — clip the coupon and get my free book. Do THAT right now. No Charges for Information on How to Proceed The booklet shown here contains valuable information relating to patent procedure that every inventor should foes. And with it I will also send you my ‘Record of Invention” form, on which you can sketch your idea and establish its date before a witness. Such evi- dence may later prove valuable to you. | mail the coupon and I will send you the booklet and the “Record of Invention” form, to- gether with detailed information on how to roceed and the costs involved. Do this OW. No need to lose a minute’s time. The coupon will bring you —- information entirely without charge or obligation. Clarence A. O’Brien Registered Patent Attorney and Attorney-at-Law Member of Bar of Supreme Court of the United States; Court of Appeals, District of Columbia; Supreme Court, District of Col- umbia; United States Court of Claims. Practice confined exclusively to Patents, rademarks, and Cop ts = j ail this Coupon Now Clarence A. O’Brien Registered Patent Attorney 88-K Security Savings and Comm’l Bank Bldg., Wash., D. C. Suite 1106, Woolworth Bldg., New York City Please send me your free book, ‘‘How to Obtain & Patent,’’ and your ‘‘Record of Invention’’ form without any cost or obligation on my part. (Important: Print or Write name clearly) a

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“I wish [ had his job” “He hasn’t been here nearly as long as I have, but he’s earning three times as much. Seems to me he’s the first man the firm thinks of whenever there is a good ition open. Always makes good too. wish I d started studying with the I. C.S. when he did.” Are you just wishing for a better job too? Are other men getting the promotions you’d like to have? Are yo. letting the precious, priceless hours slip by unimproved? You know as well as we do that you’ve got to learn more in order to earn more. And you know, too, that the best way to learn more is to take up a course with the Interna- tional Correspondence Schools and study in the spare time that most men waste. Isn’t it better to start today than to wait a year or five years and then wish you had? Mail the Coupon for Free Booklet INTERNATIONAL CORRESPONDENCE SCHOOLS “The Universal University” Box 7634-F, Scranton, Penna. Without cost or obligation on my part, a send me a copy of your 48-page booklet, “Whe Wins and Why,” and tell me how I can qualify for the position, or in the subject, before which I have marked an TECHNICAL AND INDUSTRIAL COURSES A Architect Automobile Work Architectural Draftsman (J Aviation Engines CL) Building Foreman Plumber and Steam Fitter Concrete Builder Plumbing Inspector Contractor and Builder Foreman Plumber Structural Draftsman Heating and Ventilation Structural Engineer Sheet-Metal Worker Electrical Engineer Steam Engineer Electrical Contractor Marine Engineer Electric Wiring Refrigeration Engineer Electric Lighting R. R. Positions Electric Car Running Highway Engineer Telegraph Engineer emistry Telephone Work Pharmacy Mechanical Engineer Coal Mining Engineer Mechanical Draftsman Navigation (©) Assayer Machine Shop Practice Iron and Steel Worker ‘Toolmaker Textile Overseer or Supt. Patternmaker Cotton Manufacturing Civil Engineer Woolen Manufacturing Surveying and Mapping LjAgriculture [) Fruit Growing Bridge Engineer Poultry Farming Gas Engine Operating Mathematics [() Radio TRAINING COURSES Business Correspondence Show Card and Sign BUSINESS Business Management Industrial Management Personnel Management Lettering Traffic Management Stenography and Typing Accounting and C. P. A, LJ English Coaching Civil Service Cost Accounting Railway Mail Clerk Bookkeeping Mail Carrier Secretarial Work Grade School Subjects Spanish [ French High School Subjects Salesmanship Illustrating (© Cartooning Advertising Lumber Dealer Neme.. sietaehelisaiidineidedibasiitiaatnendgiineaitgbensanebinededioninnksestines Street Address.......... Occupation wind If you reside in ‘Canada, send this coupon to the International Correspondence Schools Canadian, Limited. Montreal, Canade $165,000 REWARD for an IDEA That sum was paid to the inventor of ‘Kiddie Kars." Here is a remarkable book which tells you what inventions are NEEDED in every field. Don't waste your ideas. Send today for 1000 NEEDED INVENTIONS Prepared by Raymond F. Yates, famous inventor, former managing editor of Popular Science Monthly, who knows what manufacturers want. New, re- vised 1929 edition. This book may start you toward a fortune. Send no money. ay — a postcard. Pay mail msn only $1. ~~] poten e when book arrives. Money back after ten ys if desired. Limited offer, Write now. Get started in right direction. (Outside U. S. $1.45 cash with order.) Bureau of Inventive Science 28 Wisner Bidg., Rochester, N. MONEY MAKING OPPORTUNITIES SECTION gahela River bridge at McKeesport, Pa. Lindenthal came to New York in 1892. There, he prepared plans for the reconstruction of the Brooklyn Bridge. He was one of the board of six consulting engineers who planned the tunnels and terminals of the Pennsylvania Railroad under the North and East rivers. He also was the designer of the beautiful Hell Gate Bridge over the East River, the largest steel-arch bridge in the world, crossing from Long Island to Ward’s Island in a single braced steel span of 1,000 feet. While Com- missioner of Bridges from 1902 until 1903, he completed the Williamsburg Bridge and made the plans for the Manhattan and Blackwells Island (now Queensboro) bridges. Lindenthal, .who is the author of numerous works on en- gineering and bridge building, holds honorary doctorates from the Polytechnical Schools of Briinn and Vienna and of Dresden, Germany, and is a member of virtually every great en- gineering society in the United States and Europe. America’s Fastest Flyer FEW weeks ago the Distinguished Flying Cross was awarded to Lieutenant Alford J. Williams, crack speed pilot of the Navy. In a citation accompanying the award, it was set forth that the high distinction was con- ferred upon Williams for his death-defying experiments, such as outside loops, upside- | down spins, and inverted flights that enabled | him to evolve certain principles the practical | application of which has resulted in greater safety in aerial maneuvers and increased ac- curacy in testing aircraft. At about the same time another award was made to him by the Guggenheim Fund for his services in advancing the science of flight. These rewards, of course, are richly deserved, but to the general public and to aviation en- thusiasts particularly ‘“ Al’’ Williams is better known as “‘America’s fastest flyer.” And that title is not only honestly won, but it scarcely does justice to the prowess and skill of this picturesque American airman. Although, through a series of unfortunate delays, Williams was forced out of the Schneider Cup races at Venice in September, 1927, when British Flight Lieutenant S. N. Webster captured the trophy with a speed of 281.488 miles an hour, the American two months later unofficially attained a speed of 322.6 miles per hour at Mitchel Field, N. Y., in the converted racing plane of his own design he had prepared for the Schneider contest. This bettered Webster's mark by more than forty miles and surpassed by just about six miles the speed of 318.57 which Major Mario de Bernardi, Italian army ace, had achieved over the Lido course forty-eight hours pre- viously, and was faster than anyone has flown before or since—a speed of, roughly, five miles and a third per minute! For the last two years, Williams has been working quietly on plans for a racing plane that, in the Schneider eup races, will bring the world’s seaplane speed record back to the United States. It is believed the project is sponsored and financed by a group of pa- triotic American sportsmen and patrons of aviation. Williams first achieved international fame as an air racer in October, 1923, when, as a member of the team of Navy pilots participat- ing in the International Air Races at St. Louis, Mo., he won the Pulitzer Trophy with a speed of 246.67 miles an hour for 200 kilometers in a Navy R2C1 plane. This remains the world’s record for that distance. He bettered his own mark the following month, when he established the then world’s record for airplane speed of 266.6 miles an People in the Public Kye (Continued from page 135) Aucust, 1999 ———_ hour at Mitchel Field. But in the Pulitzer Trophy race of 1925 he dropped to 241.71 miles per hour, the event being won by “Cy” Bettis of the Army with a speed of 248.99 miles per hour. “Al’s”’ present ambition is said to be to win the 1929 Schneider Cup with a record of some- thing approaching 325 miles! Williams, aside from being America’s and perhaps the world’s fastest flyer, is probably the only aviator who is also a lawyer and a baseball player! Born in Bronx C ounty, N. Y,, thirty-five years ago, he was educated at Fordham University, N. Y. Upon graduation from college, he signed up as a pitcher with the N. Y. Giants, and played professional baseball for two seasons. Meanwhile, he took up the study of law at Fordham. When the United States entered the World War, “Al” enrolled in the Naval Reserve Force. At the end of a ground course for aviation at Boston Tech., he went to the Naval Air stations at Bay Shore, L. I., and Pensacola, Fla., for flight training. This com- pleted, he stayed at Pensacola to teach. While engaging in his air races and un- equaled aerial experiments, Williams found time to complete his law studies at George- town University, Washington, D. C., from which he received an LL.B. in 1925. The fol- lowing year, he was admitted to the New York Bar. Williams, who is married, at present is connected with the Bureau of Aeronautics of the Navy Department, at Washington. Discoverer of Stars OT long ago, Dr. Harlow Shapley thrilled the scientific world with the announce- ment that the hub of our universe, sought by astronomers for centuries, had been located by the Harvard College Observatory, of which he is the director. This stellar nucleus, around which our whole galaxy of heavenly bodies spins in space like a gigantic wheel, the Har- vard astronomers placed at a distance of 47,000 light-years from the earth in the direc- tion of the constellation Sagittarius. Just recently, it came to light that it was a young girl, Miss Henrietta H. Swope, who was chiefly responsible for this momentous gain in astronomical knowledge. Dr. Shapley insists it was her discovery of nearly 400 new variable or “winking’’ stars in the Milky Way that permitted him to make the intricate calculations which finally enabled him to put his finger on the center of our universe. Miss Swope, the daughter of Gerard Swope, president of the General Electric Company, is one of the assistants on the Harvard Ob- servatory Staff. She was graduated from Barnard College, N. Y., only three years ago. Astronomy had been her hobby in under- graduate days, so when, after a year of social science study at Chicago University, she learned of an opening in the department of variable star research at Harvard, she returned east and obtained the position. But it shouldn’t be imagined that Miss Swope was assigned to observation duty on some desolate mountain peak. Of late years, there have been many changes in astronomical research. Photographic plates now replace personal observation to a large extent and often the microscope takes the place of the telescope, not only changing astronomy, at least partly, into a “daylight science,” but also making it one which women may pursue without hardship. About the time Miss Swope started on her job, Dr. Shapley had begun a comprehensive investigation of the Milky Way to determine the distances of its individual stars, nebulae and stellar groups. He had devised a new method involving the (Continued on page 137) TLR =ya ars ae ear —-

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, 1929 and om- ach. un- und rge- rom fol- ‘ork it is s of lled nce- ited rich und dies Lar- rec- as a who ous ley new ky rate put pe, ny, Ob- “om 1g0. ler- cial she ned [iss ars, ical ace und the at but sue her jive ine lae ew 137) OR erm eee re =o a irk Rees ~~ Aucust, 1929 ——— People in the Public Eye (Continued from page 136) measurement of the variability of the changes in the luminosity of a star. The new method made possible the determination of distances 100 times greater than those that could be measured under systems previously used, but its application demanded mathematical ability of a high order. At Barnard, Miss Swope had majored in mathematics, and so this part of the research work fitted her like a glove. Dr. Shapley divided the Milky Way into 240 fields for the photographic survey, in which some 60,000 plates in the Harvard files were used. Miss Swope was assigned to one of these fields to discover as many new variable stars as possible. In her first year, she found very few. But last year she uncovered no fewer than 385 tiny stars that had never before been known to fiuctuate in light. Each one of these stars she measured photo- metrically, charting its period of variation from minimum to maximum luminosity by comparing the various photographic plates on which it appeared. Then she applied slide rule and logarithms to translate the result of her studies into statistical data. Upon the completion of her assigninent, Dr. Shapley made an analysis of her work. A few weeks later he told the scientific world that one of the great quests of the centuries was at an end—the hub of the universe had been located at last! Thus, at the age of only 26, Miss Swope has become an outstanding figure in scientific research, upon whose work the attention of astronomers throughout the world is focused. She is the author of. two articles on variable stars, one of which she prepared with the assis- tance of her distinguished director. Naturally, Miss Swope can’t help but be thrilled by the success of her efforts, but she refuses to accept credit for the discovery of the center of the universe. “That,” she says, “belongs to Dr. Shapley. He is the scientist. I am only the handmaiden of science.” Here Are Correct Answers to Questions on Page 51 1. It does no harm to any modern watch or plain clock to turn the hands backward to set it to the correct time. But if a clock con- tains striking or alarm mechanism it should be set only by moving the hands forward. Really high grade clocks that strike the hours are so constructed that no harm will come to the mechanism no matter which way they are set, but it is better to play safe. 2. The normal position for a pocket watch is winding stem up, but the watch may assume two other positions in the pocket if the stem tips over one way or the other. Then when the watch is placed on the bureau at night it may be placed face up or face down, a total of five positions. Theoretically, if the balance wheel, the hairspring, and the pallet are in absolutely perfect balance the watch will run at the same rate in any position. Any unbalance results in a pendulum action that is varied with position. Adjusting for position therefore means careful balancing. 3. The principal difference between a pocket watch and a chronometer is in the construction of the parts that drive the balance wheel. The chronometer balance wheel is larger and heavier and the escapement is so made that it oscillates completely free of the escape mechan- ism except for a brief period in one direction. Chronometers are hung in gimbals so that the balance wheel always oscillates in a horizontal plane. 4. No timekeeping (Continued on page 138) MONEY MAKING OPPORTUNITIES SECTION 137 PATENTS TRADE-MARKS + DESIGNS FOREIGN PATENTS MUNN @ CO. PATENT ATTORNEYS Associated since 1846 with the Scientific American 1551 SciENTIFIC AMERICAN BUILDING 24 W. goth St., New ScIENTIFIC AMERICAN BUILDING 625 F. Street, Washington, D.C. ork City 1303 Tower BuILDING 511 Van Nuys Burtp1nc ~Hosart BuiLpING a Spring « Seventh Sts. 582 Market St. Los Angeles, Cal. San Francisco, Cal. Chicago, Ill. Crk QORTD Books and Information on Patents and Trade-Marks by Request Associates in all Foreign Countries A NEW minutes GET the BEAUTY and LUSTRE ofa NEW PAINT JOB at a small fraction of ' Gf samen | the it Yourself NUKAR. NOT a Wax, ‘ou! Paint or ‘Pollen. This New Chemical Discovers in- stantly restores original color ko dull faded shabby OVES IT ids a Beautiful, Brilliant, Lustre, that lasts for months. No rubbing --- No hard work - on | open froma b sponse --- No waiting. Drive a NEW CAR the Same “Day. MEN! Amazing Cash PROFITS se aie fembe tors and Service Station operators. Earn oe to > $50 a oo. _aee a sensational sales sonpeliie Demonstration. Fy and give you FREE Business Start that none could not ae a us send prepaid a ‘and without charg sh FREE BOOK | TELLS HOW You can quickly qualif. vd postions paying to a& week in Motion Picture, Commercial or News Photography and Projection, or start your own business. No ex- perience needed. CAMERA OR PROJECTOR GIVEN Learn at home or in our great New York Studios. Write for Big Free Lak fl of smasing opportunities, Job Chart and Camera or projec’ r off: NEW YORK INSTITUTE OF PHOTOGRAPHY Dept. 5 10 West 33rd Street New York PATENTS Trade-marks, Copyrights, Patent Litigation, Handbook with illustrations, 100 mechanical movements. Sent free on re aR] ALBERT E. DIETERICH ber E. Corp. U. 8. Patent Office Registered Patent Lawyer and Solicitor 30 years’ experience 681-A Ouray Bldg. Washington, D. C. PATENTS BOOKLET FREE = a PROMPTNESS ASSURED Send drawing or —- for «tune an WATSON E. COLEMAN, Patent Lawyer 724 Ninth Street Washington, D. C. PLE and our B Book in colors. Act NOW. Write = ATLAS SOLVENT CO., 5647 Harper Ave., Dept. 150 CHICAGO, ILL. As Y~ of fhe oldest pat- ent 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. Lacey& Lacey 648 F St., Wash., | D.C, Estab. 1 INVENTORS We have been in business 30 years. If your invention or patent has merit, send details or model, or write for information. Complete facilities. References. ADAM FISHER MFG. CO. 183-D Enright, St. Louis, Mo. TRAVEL FOR “UNCLE SAM” Railway Postal te $158 to $225 a Month MAIL COUPON BEFORE YOU LOSE IT See eee ee SSB SS Bee SB eee ee SS f FRANKLIN INSTITUTE, Dept. T-271 r) Rochester, N. 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Graduates of the S. of E. are *reg- istered’ without examination. : Most Thorough Practical Radio Course in America Here in this big splendidly equipped electrical school (from which Sta- tion WISN is oper- ated) you can se- cure in three months the most thorough, the most compact and practical radio training offered anywhere. Covers entire field of radio! Complete course in- cludes Radio Lab- oratory Practice, Radio Telephon Transmission, le Instruction, Theo lectrica matics, Service and Installation, Radio Sales and Merchandising. Daily broadcasting from WISN All training is 100% practical. You learn everything in three short months! , Radio Mathe- TELEVISION INCLUDED Complete Radio Course also includes study of funda- mentals of Television and latest developments in that gigantic new field. Enables anyone to keep up with progress of this new industry. EARN WHILE YOU LEARN Not only do we help place our men after graduation, but we can arrange for part-time employment for ambitious men who can finance their tuition. This will cover part if not all of your living expenses while you are taking the Radio Course at the School of Engineering. SEND FOR FREE BOOK Send today without obligation, for FREE catalog describing the wonderful opportunities in radio, the three month Radio rse, and details of our Earn While You learn Plan. SCHODL °f ENGINEERING Is KHEOLe ——aa School of Engineering Milwaukee, Wis. Without obligation, Please send me FREE Book describing your months “Radio-Technician” | course and full details of your “Earn While You Learn Pian.” | Dept. P.S.M. 829 ! Z , : hth tkketennnenecdedés ee ili tthcicatentnion any wien tne ane wn cine oo MONEY MAKING OPPORTUNITIES SECTION Aucust, 1929 Here Are Correct Answers to Questions on Page 51 (Continued from page 137) mechanism keeps perfect time. Friction can- not be entirely eliminated nor even made uniform. Temperature correction is never perfect. Changes in the density of the air have some effect. A very fine pocket watch, wound regularly and handled carefully, should show an error of not more than half a min- ute a month and may do even better for sev- eral months in succession. 5. A cheap stop watch of the type sold for a few dollars is simply an ordinary watch mechanism fitted with a solid balance wheel not compensated for temperature, positions, or anything else. Pressing the button lifts a brake out of contact with the balance wheel and the watch starts. Another pressure stops the balance wheel and a third pushes the hand back to zero by means of a cam. A high grade stop watch has a finely compensated mechan- ism that runs continuously and the hand is operated by throwing fine toothed gears in and out of mesh. Split second stop watches have two hands, the two traveling as one until a omegeg on an additional button clamps one of them. 6. The term “railroad accuracy” has no very definite meaning. Most railroads require that men who control the timing of trains carry a 21-jewel, 16-size, lever set watch and each watch must be cleaned and inspected by an approved watch repair firm once a year. The number of jewels beyond 17 has no bearing on the timekeeping qualities of a watch other than the fact that a watch has 21 or 23 jewels is good evidence that it is of high grade construc- tion throughout. Sixteen-size is specified be- cause the thin, small watches now so popular are not sufficiently reliable. Lever set is specified so as to eliminate the possibility of the user accidentally disturbing the setting of the watch while winding. 7. The earliest recorded timepiece is the sundial. It was of no use on a cloudy day. Following that came the clepsydra, a water clock, used by the Greeks and Romans. It consisted of a container from which water was allowed to run through a small orifice. The sand glass, still much used for timing the boiling of eggs, preceded clocks and watches. 8. The term “isochronism,”’ as applied to a timepiece, refers to its ability to run at a uniform rate at all times during the period be- tween one winding and the next. A low grade watch not adjusted for isochronism may gain time during the first hours after winding and then lose near the end of the run’ Such a watch might show a small daily variation and still be unfit for use in accurate timing because of alternate slow and fast running. 9. A properly constructed and accurately compensated pendulum clock is the most ac- curate timepiece available. In fact the in- troduction of the pendulum marked the first important step in the development of a time- piece that would really keep accurate time. 10. 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Avaust, 1929 MONEY MAKING OPPORTUNITIES SECTION 139 - Crushed in the Jaws of Arctic Ice (Continued from page 26) ask for grub. On this ship men who don’t work don’t eat.’ “The skipper’s bluff carried him through. In a couple of days the gang got hungry and put canvas on the vessel and she made port with only one more death. It turned out the disease was typhoid fever, which we must have got in our water. T he skipper was sport enough not to make an official report of the mutiny. As a result the same crew shipped over again, and many of them stuck by the Old Man for years.” ‘**What happened to the leader?”’ I asked. “Oh, the skipper got absent-minded and left him in the lazarette so long that he had to go to a hospital when we got in. I heard after- ward he got well, but wasn’t much good any more. Probably served him right.” At this point in Bartlett’s tale a near-by factory whistle shrieked the news that it was noon. HE dips,”’ muttered the captain, meaning that the sun had passed the meridian. He opened a fine oak box containing his chronom- eter. As he wound the expensive timepiece, which read Greenwich time, he turned to me and said half-apologetically: ‘I don’t own this fellow. Alarm clock is good enough for me.” “Alarm clock! And you can make a safe landfall?” He grinned. ‘‘Oh, once in a while we have a little trouble. I remember a few years ago a skipper named Ed Simmons, coasting home from Boston, got in thick weather. After a couple of blind days he saw the loom of the land ahead. Ran in close until he saw a farmer down near the beach. “*What part of Newfoundland is that?’ he sang out. “The farmer didn’t answer until he’d given another hail. Then the man said: ‘This ain’t Newfoundland. It’s Nova Scotia!’ You should have seen Ed beat it, lest he be recog- nized and laughed out of every pub down the coast.” Such navigating seemed pretty precarious to me, and I said so. *“’'Twould be for a deep sea voyage to a clear coast. But don’t forget I’m talking about those who have to feel their way for hundreds of miles without a sight of the sun, no sort of speed or drift for their dead reckoning. “A few years ago five ships were lost in one blow down the Labrador. My uncle Isaac Bartlett’s brig, The Brothers, was caught off Cready by a knockdown northeast gale and ran for the tight ice inshore. She was caught in pressure and crushed to pieces. The men escaped by clambering over the ice. “NEXT morning Uncle Isaac walked down the coast to see if he could find shelter for his men. He happened to glance out across a stretch of ice-free ocean where there was a reef about three miles offshore. Through his glasses he caught sight of something mov- ing on the small patch of rocks. At first he thought it was a seal. Then he saw it was a man. “He found help and reported the man on the reef. Remember it was early spring and bitterly cold; and of course the spray of the sea was washing over the poor devil. But when ae put out and took him off he was still alive. “*T’m from the Huntsman,’ he whispered, scarcely able to talk. ‘She went down inside.’ “Then we knew what had happened. In the a and fog the skipper of the Huntsman had ound the opening between the reefs and had driven his ship through as straight as a die; a fine piece of piloting that the best navigator in the world could be proud of. “The trouble was (Continued on page 140) our terms, methods, etc. Send of your invention for Inspec- tion and Instructions Free. 1 Terms Reasonable. erences. RANDOLPH & CO.: Dept. 130, Best Ref- Washington, D.C. 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140 . MONEY MAKING OPPORTUNITIES SECTION

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Crushed in the Jaws of Arctic Ice (Continued from page 139) that surf and slush ice lay beyond. Together they smashed the ship and drowned the whole crew—all but one man, the fellow who was on the reef. Knowing what was ahead, he had had the quick wit to hop overboard as the Huntsman shot by. He swam a few strokes to the rocks and climbed up.” “But how was he able to live?” Bartlett shrugged. “A tough one, he was. Both legs were broken by the seas when he was picked off. Yet he lived.” “TRON men and Wooden Ships” is no idle phrase for such mariners. Indeed, only an iron man could survive the fare Bartlett de- scribed as the usual diet. There was usually on the Newfoundland vessels only one big meal a day. This was served out about noon. Seal meat, strong and blubbery, was the main staple. Three times a week a delicacy was added: boiled flour-pudding and pork. “This mass was about the color of gutta percha and almost the same consistency,” he explained. “‘Tea sweetened with molasses and hard bread were served in addition at each meal.” “But can any man stand swimming in cold sea water?”’ I persisted. For reply Bartlett thrust his wrist clear of its sleeve. “See that scar? Got that when I was mate on the Grand Lake. I was working on the forecastle, clearing up the ground tackle after we had run out of a northerly port in winter time, when I lost my balance and went over the rail. In reaching for a hold I sliced a piece of flesh clean out of my forearm. “The fool sailors were so surprised—maybe glad, too—that they just stood there like a lot of wooden Indians for a moment or two and didn’t utter a sound. Then one of them piped up and passed the word that the mate was overboard. “Instantly they broke for the rail over which I had just disappeared and looked down into the cold water to see if I was hanging on. Well, I was hanging on, all right; only it was the other side. I had caught hold of a wire line that ran from down to the lower part of the stem and hauled myself up. **T climbed on deck, dripping wet and pretty cold in the raw wind just in time to hear another man sing out: ‘The mate’s gone!’ ** “Yes, but he’s back again!’ I let go right in the fellow’s ear. ‘Now turn to, you cock- eyed loafers!’ HEN there was another time on one of my early sealing trips when I was little more than a lad. I'd killed and skinned a fine seal. While I turned my back the ice opened and the next moment a lane of open water separated me from the pelt. “‘T hated to lose it because I was trying to make a name for myself. I knew that the cap- tain kept a record of the skins each of his men brought in, and the size of each. In less time than it takés to tell I made up my mind to get that skin. “Although the temperature was down around zero I slipped out of my woolens and underwear and plunged in. Shock of the cold water on my bare skin was like getting a thousand volts of electricity right through my body. But I made the other side and crawled out on the ice. As the air was much colder than the water I didn’t hesitate. I grabbed the skin, swung it around my head, and tossed it back. “When I dived in again I was so numb that I didn’t even feel the water. I thought I'd perish before I got dressed. But I finally managed it, then ran and swung my arms until feeling came into my body again. i didn’t even catch cold. **On the Polar Sea with Peary falling in was more serious. On the North Pole trip of 1909 we had temperatures around sixty degrees below zero. “One day I was crossing a lead on young ice and broke through. The water felt warm. That was because the sea, you know, never gets colder than twenty-eight degrees above zero, no matter how cold the air is. The surface may freeze, but the water beneath remains at practically the same temperature all the time. “Luckily the Eskimos, Etukeshuk and Egingwah, were with me. They had me out inside of three minutes. Instantly the water began to freeze on my clothing. And I would have perished had not they stripped my soaking furs off and shoved me into my sleep- ing bag. Then when I got warmed a bit they passed in dry clothing and I was dressed and out and on the trail again in half an hour.” Speaking of his work with Peary, Bartlett reminded me of what I consider his greatest adventure, the loss of the steamer Karluk.. He commanded her in the summer of 1913, when Stefansson took the Canadian Arctic Expedi- tion north through Bering Straits and along the coast of Alaska, with a view of exploring the Polar Sea to the eastward. HE Karluk was caught in the ice and blown northward without Stefansson aboard. The leader had gone off hunting just before the storm, and when he returned his vessel had disappeared. “She drifted out into the polar pack,” Bartlett reminded me, “struggling against the increasing pressure. The sun left us in early November, not to return again until spring. The temperature fell into the fifties below zero. “On New Year’s Day, 1914, we were all sitting huddled around our little stove below when the pressure suddenly grew worse. Pro- visions were hurriedly taken on the ice. Ten days later the Karluk gave up the uneven battle and sank. “We had a tough time making our way south to Wrangell Island. Six men died. From Wrangell I continued on to Siberia and finally reached Alaska where I took out a rescue ship in the summer.”’ ““Wasn’t there some incident of that whole adventure that sticks with you?” I asked. Perhaps it was a morbid thought, but it seemed to me that the party’s fearful months of cold and starvation must have left at least one high point of dramatic value on the cap- tain’s memory. E NODDED as he refilled his pipe. ‘‘ Yes,” he said, “‘there was. I had escaped from the Karluk, I hadn’t frozen on the ice, I had somehow got across the hard miles to land, and then I almost failed!”’ What a situation! Success in sight after long harrowing months of frozen feet, short rations, heavy sledges. Surely Bartlett was about to divulge some hitherto unconfessed thrill, when he trembled on the brink of eternity. **When I reached the Siberian coast I could not go on without native help. I found a hunter who said he would guide me eastward. ‘How much you pay?’ he asked in the little English he had learned from traders and whalers. “T had brought forty dollars in gold with me from the Karluk. As it was vital that I hurry I thoughtlessly told him I’d pay him the full amount. I could have bitten my tongue off the next instant. Any trader would have had the sense to offer a small price and then bargain up towards what the native asked. (Continued on page 141)

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Avaust, 1929

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Crushed in the Jaws of Arctic Ice (Continued from page 140) “Show me money,’”’ said the native. “But I refused. Then he accused me of not having any. We argued for two hours. He knew only about twenty-five words o English and I knew about three words of his dialect. He bawled at me in Eskimo and I at him in English. “There we were out on the wind-swept desolate north shore of Asia, with the ther- mometer twenty below and nothing but snow and ice as far as the eye could see, and jawing at each other for all we were worth, and not understanding a thing the other said! “Well, the end of it was I convinced the fellow I had some money with me and he was avaricious enough to want to get at it. So he guided me east, I keeping my eye on him every inch of the way to see that he didn’t attack me and steal my pile. Every now and then we'd break out and argue about the forty dollars, seeing which could yell the loudest. ** AFTER we had gone far enough for me to find the trail the rest of the way he suddenly decided to desert me. I suppose he was afraid we'd meet traders and I might tell them he had tried to rob me. I gave him five dollars for what he had done and showed him the rest of the money, which made his eyes stick out half a fathom!” I asked Captain Bartlett one question that had been on my mind for a long time. ““Were the old skippers as severe with their men as they are described by fiction writers?” The captain doubled up one fist and gazed at it with a reminiscent look in his eyes. “Yes and no,” he replied. “Yes, the old- fashioned skipper never hesitated to use force if he felt the situation needed it. And no, he didn’t beat up a man just for the sake of being rough. Needless violence would only have damaged the respect which the good skipper always wanted from his men, no mat- ter how poor or disloyal a lot they were. ay MY day a good skipper was usually a fine physical specimen who could stand up and thrash any average seaman in a knockdown fight. That’s why he was picked as skipper. “IT sailed as mate with Captain William Cross of the Strathavon out of Sydney with a cargo of ore and coal. One day a big loud- mouth came aboard with a longshore bun on and got fresh with the old man. Captain Cross didn’t blink an eye, but took the fellow’s lip without a word—until he’d had his say. Then the captain took one crack at him and slammed him so hard to the deck that it took the cook half an hour to bring him to. “Another time Captain Cross lost his temper with the whole forecastle gang. Without hesi- tation he strode forward and hopped down the ladder, spry as a monkey. As first mate, it was my job to follow; also I was afraid the old man would meet more than his match. ‘But he was a veteran at such work. He knew the value of surprise. Before ‘the men knew he was around he pasted the nearest one on the jaw and dropped him cold. The next one stepped forward to meet the captain but rolled into a lower bunk holding a cracked chin. ‘“‘T had arrived when the others rushed. The captain sidestepped and sent the leader stag- gering against the bulkhead. By this time the heart had gone out of the crew. Captain Cross never said a word. He just turned and went up the ladder. I found him on deck brushing his sleeve where he had rubbed against some fresh paint. Strange to say, he was more popular than ever after that little scrap.” I thanked Captain Bartlett and left him feeling more than ever that the mariner is a distinct species of human being and like none other on the face of the earth.

MONEY MAKING OPPORTUNITIES SECTION 141 gole sch ot Home, = ~ Le, 4

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Avucust, 1929 At the Throttle of the “Big Hog” (Continued from page 53) the Keyser yards—the thing that impresses me most is the way railroading has become safer and easier. When, after I had worked in the yards and shops for a few years, I started firing freight hogs in 1896, there were plenty of accidents, some of them bad ones. And no wonder—freight cars had link-and-pin couplings in those days—one reason why there were sO many one-armed and one-legged rail- roaders around!—and most of the cars had hand brakes, with only an occasional air brake car. Locomotives were little things compared to what they are today—the old 500’s were only sixty tons—and a train of from.sixteen to twenty light cars needed a helper engine to get it over these grades. Then, after a while, air brake equipment became more common, automatic couplers came into universal use, locomotives got bigger and trains longer and heavier—and railroading became safer as well as easier. “Some of the real old-timers didn’t think it would. I remember when they sent the first 1600’s to this division—seventy-three-ton engines. Old Frank Snyder took a long look at one of them, rushed into the office, and slammed his hat down on the boss’s desk. ‘I’m through!’ he yelled. ‘I’m not going to risk my life on an engine that big!’ He meant what he said, too—he quit! “W ONDER what poor old Frank would say if he could see this 5501, or its year-older brother, the Lord Baltimore—both of them built in the company’s Mt. Clare Shops in Baltimore. An engine with a weight of 275,000 pounds on its eight seventy-four-inch driving wheels, with a tractive power of 68,200 pounds, and a total weight of 400,000 pounds. An engine fifty-five feet long from the point of its pilot to the end of its deck—and a few inches over 100 feet long with its 258,000-pound all- steel tank tender, which has a coal capacity of twenty-one and a half tons, a water capac- ity of 15,100 gallons, and a total weight of 493,000 pounds fully loaded. ONDER what old Frank would think of a fire box eleven feet by eight feet, and with a grate area of ninety square feet, stoked by an automatic stoker—the strongest-backed fireman on the division couldn’t handle that job properly with a coal scoop. Wonder what he would have to say about the rail washer, which washes the sand off the rails after it has done its work of giving the drivers a good grip—washes it off so that the passenger cars behind will have a smoother ride. An engine a lot bigger than he ever dreamed of—and one easier to handle than were his little ‘old 500’s. Yes, sir—a mighty fine engine! The biggest mountain-type locomotive in passenger serv- ice. Other roads may build bigger engines, but if there’s ever a better engine built, the Balti- more and Ohio will have to build it!” In that last remark of Jim Pugh’s you can catch a glimpse of the spirit of the highest type of engineer—outspoken pride in his loco- motive, and deep-rooted loyalty to his rail- road. The Philip E. Thomas and the Lord Balti- more are the highest development of the moun- tain-type locomotive—which is a locomotive with four engine-truck wheels, eight driving wheels, and two trailer wheels—technically a 4-8-2 type locomotive. While Jim Pugh was telling me about its mechanical marvels my thoughts went back a hundred years to the little Tom Thumb, forefather of all the Balti- more and Qhio’s big modern locomotives. There’s an amusing—and true—story about that little engine. In 1829, rails had been laid from Baltimore to Ellicott’s Mills, a distance of only a dozen miles or so, but with sharp curves and steep grades. Steam locomotives had been built and successfully operated, but it was thought that for this line horses would furnish the best motive power. Peter Cooper, a New York merchant with commercial interests in Balti- more, saw the shortsightedness of this policy, and built a small experimental locomotive to prove that steam could take the place of the horse. His Tom Thumb—it wasn’t much larger than a modern hand car, and had an upright boiler with tubular fluesimprovised from old rifle barrels—was completed early in 1830, and on a fine August day demonstrated its powers by drawing a light car filled with railroad directors and their friends out to Ellicott’s Mills at a speed of fifteen miles an hour. Peter Cooper was delighted—his engine had proved that it could conquer curves and grades. Now entered the villain—a stagecoach pro- prietor, who had no use for railroads. The railroad was double-tracked as far as Relay. The stagecoach man pulled strings, with the result that when the Tom Thumb, headed for Baltimore, reached that place, a light car, drawn by a fast gray horse, was waiting. Crack! went the driver’s whip as the engine came abreast of him—and the race was on. Peter Cooper opened his throttle, and the Tom Thumb leaped into the lead as the direc- tors cheered. Cooper jammed more wood into the fire box, and the Tom Thumb increased its lead. But the steam pressure mounted too high, the safety valve lifted—and the little engine “‘popped off!’ The waste of steam caused it to slow down, and Cooper and the disgusted directors saw the gray horse gallop past them to win one of the queerest races ever run. * * * Now we were well out on the Seventeen- Mile Grade—that uniform 2.4 percent incline of steel rails that carries the Baltimore and Ohio’s line to the top of the Alleghenies. The locomotive swayed and pounded, and in the cab there was unceasing uproar—the rumble of wheels over rail joints, the hiss of escaping steam, and always the monotonous clank- clank-clank of the duplex stoker as its feed worm carried crushed coal from the tender to the elevators just aft of the fire box door, then up through the elevators into the fire box, there to be distributed with more than human skill. AVES your back, doesn’t it?’’ I said, nodding toward the stoker. ““Saves me shoveling six tons of coal between Keyser and Grafton,’ replied Fireman Fazen- baker, grinning broadly. Through cut and over fill, around curve and along tangent, the 5501 thundered on through the darkness—to me a thrilling and never-to- be-forgotten ride—to the other three men in the cab just another run over the West End. Now a lonely square of light came in view ahead—the window of a telegraph tower. As we approached we saw a white light burning ona board protruding from that window. No orders! “Clear board!’’ called Fireman Fazen- baker. “Clear board!’ echoed Engineer Pugh. If there had been a red light burning on that board it would have meant that train orders waited there, and Jim Pugh would have had to stop even the National Limited to get them. On through the night, along lonely mountain sides, through infrequent towns all dark and sleeping—and then a green light ahead. “Caution!”’ said Engineer Pugh. “Caution!” repeated Fireman Fazenbaker, peering out of the left-side window. We slowed down, after a while coming to a gentle stop—no use in waking the sleeping passengers in the Pullmans back there. Torch (Continued on page 143) as Oy AE ERE

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POPULAR SCIENCE MONTHLY 143

At the Throttle of the “Big Hog”’ : (Continued from page 142 and long-spouted oil can in hand, Pugh was on the ground and busy oiling the locomotive almost before its drivers ceased turning. Lan- terns gleamed ahead. Then a helper engine backed slowly down to us, and coupled on ahead to assist us over the ““hump.” * * aa The helper cut off, we were away over the eighteen miles of rolling plateau country on the crest of the mountains, and soon we were drifting down the Cheat River Grade. Fire- man Fazenbaker turned a wheel that shut off the driving steam from the stoker, and lighted a cigarette. ‘“‘Now we're on my side of the hill,’’ he said. Grafton, and good-nights. The 5501 rum- bled away toward the roundhouse, there to be carefully inspected and serviced for the return trip. The National Limited, hauled by another locomotive and manned by another crew, rolled away toward St. Louis. _ re they have reported anything that needs adjustment or repair,” said Char- ley Schuh as we walked across the station platform to the hotel door, “the enginemen can turn in and sleep until a half hour before leaving time in the morning. The 5501 will be taken care of by the mechanical force at the roundhouse. After a locomotive has given about 75,000 miles service—say every eight months—it is sent to the shops for a thorough overhauling.” He looked at his watch. ‘‘ Maybe you noticed,” he says, his casual tone not con- cealing his pride, “‘that we made up that twenty minutes of lost time.” Wheat cakes and black coffee at dawn in the all-night railroad restaurant at Grafton sta- tion. Then aboard the 5501 again—a 5501 all shining from the attentions of the roundhouse men. Jim Pugh nodded a good-morning; Fire- man Fazenbaker manipulated the bell cord and we were off again, this time hauling the National Limited toward New York—back across the mountains through the clean air of early morning. Back in Keyser, a Pacific—4—6-2—ty pe high- speed passenger engine took the place of the 5501 on the National Limited. ‘‘She’s a flyer,”’ said Charley Schuh. “It’s all downhill from here for a hundred miles to Weverton, the end of the East End of the Division—and then all downhill or level into New York. We're the fellows who do the two-fisted work on this railroad!”’ “ATO,” SAID Jim Pugh, sitting with his hands clasped in his lap in the road foreman’s office, “nothing exciting ever hap- pened to me. Nerve strain? No, I’ve never felt any. Wrecks? No—it’s been my aim to keep out of them. You see, I’m a careful sort of man. You see, I don’t get time to do any- thing exciting—I make two round trips to Grafton, and then lay off a night here at home. What do I do on my days off? Oh, just stay around home— fish a little in the spring, and hunt a little in the fall. I’m mighty sorry, and I'd like to help you—but I’m afraid that you can’t make a story out of me!”’ From the window I watched him cross the station platform—a stubby, solid sort of man, who watches carefully where he is going, and at each step places his foot solidly on the ground. No, not much of a story in Engineer Jim Pugh. He lacks the romance and color of the legendary Casey Jones. But when I turn in on a sleeper I like to think that a Jim Pugh is at the throttle up there at the head end, and another Jim Pugh at the throttle of the train behind us. And the best part of it is that Jim Pugh, as well as being a real man, is typical of the American passenger engineer!

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