Popular Mechanics 1926-11: Vol 46 Iss 5

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€ ¥ POPUEAR MECHANICS MAGAZINE WRITTEN SO YOU CAN UNDERSTAND IT

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Man Says— “ATKINS ‘Silver Steel’ to Cut Metal’ cAnnounting a wonderful new ATKINS “Silver Steel” Hack Saw Blade for hand use. Tests show it will cut six times as long or as much metal and twice as fast as any hack saw blade you ever used. ATKINS “Silver Steel” Blades tor metal cutting are a develop- ment you should know about and be using NOW. If your hardware dealer cannot supply them, write us and tell us what metal you are cutting, and we will see that you are supplied. E. C. ATKINS & CO., Est. 1857 Dept. P, INDIANAPOLIS, IND., U. S. A. Leading Manufacturers of Highest Grade Saws for Every Use; Saw Tools, Saw Specialties, Plastering Trowels, and Ma- chine Knives.

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POPULAR MECHANICS ADVERTISING SECTION ge “ean LECIRICITY in Spare Time H' RE’S BIG NEWS for me! interested In Elec- If you are now earn- ing less than $40 a week, here’s the QUICKEST way to wn Electrical Expert’s job at $60 to $125 a week. The first t of our new, rapid, sim- to train you at home in with Lessons, Job- Outfits. Lessons which ry out of Electrical Job-Tickets which apply rn in lessons, and give tep directions for doing tricity The Laws of Elec- tricity understand- ple language man who has had only common schooling starts with thesimplest principles of Electricity and progresses by easy stages until it gives you Elec- trical Engineering subjects, trical Drafting, Automotive Elec- tricity and Radio. for the New Way to Start! Find out if you like Electrical work—find out if our lessons and job-tickets are EASY to master. Don’t take our word for it—SEE for yourself before you decide START with the COUPON, below We'll send you 5 Job-tickets absolutely FREE- the same material sent to new students when they pay their money and enroll—to prove that you can learn at home in your spare time— to prove this training is hon- est, complete, made easy to : simple. in sim- written This training Elec- i work. Outfits of t s and materials with DO THE JOB. Read this : : t. I ement t opens oe ~, et ne ee: | A wonder- : ful new / 8 system originated es atthe American School. After you have the theory from the lessons, we virtually send you “out on the job” with job-tickets and outfits. The job-tickets are illustrated and give one-step-at-a- time directions for doing practical work. They show which materials and tools to use and tell you short- | Ge Job Service We can often aid students to find a beginner's job soon after enrolling. merican School cuts and new ideas used by EX- anaes PERTS Success for You in Electricity—or Your Money Refunded! When we accept your enrollment for this wonderful home-instruction in Electricity we give you an agreement in writing that we will help you find a well-paid Electrical position within 60 days after you finish, or every penny you have paid will be refunded. American School Now beginning its 30th year of service. Chartered as an Ed- ucational institution Not one dollar in profits has ever been paid out every cent received for tuition has been returned to our students in instruction and service. Over 200 educators, executives and engineers have prepared the instruction we offer. Dept.E-874-A,Drexel Fa * Ave. and 68th St. Chicago Seven outfits of standard tools and materials now supplied without extra charge to ever; student. With lessons to explain WHY and Job-Tickets to tell you HOW, this valuable equip- ment enables you to get a PRACTICAL sfant on Elec- tricity—OUICK! Every stu- dent is furnished these outfits. 1. Soldering Furnace 2. Electric-light Wiring Equipment . Bell Wiring Equipment . Voltmeter and Compass 5. Transformer . Radio Receiving Set . Standard Power Motor Chief Engineer DUNLAP Electrical Division, American School, Dept. E-874-A, Drexel Ave. & 58th St., Chicago Send me, please, 5 Job-Tickets, absolutely Free, and facts about the great Electrical business. Name Street No.. City

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POPULAR MECHANICS ADVERTISING SECTION Heav batte estab] ard of Ex Du Dd) Dui any EARLE E. LIEDERMAN, The Muscle Builder Author of “‘Science of Wrestling,’’ “‘Muscle Building,” “‘Secrets of Strength,” “‘Here’s Health,’ “Endurance

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POPULAR MECHANICS ADVERTISING SECTION Here’s the most economical “B” battery ever built IN THE production of Heavy-Duty radio “B” batteries Eveready has established a new stand- ard of economy. Eveready Heavy- Duty 45-volt “B” Batteries will outlast any Light-Duty 45- volt “B” two to one regardless of the number and kind of tubes used! More- over, though lasting vice aslong,they cost only one-third more! To cap the climax - “B” battery economy, i Eveready Layerbilt No. 486, Eveready has per- fected a Heavy-Duty “B” for radio battery of unequaled en- durance and dependability —positively the best “B” battery its price can buy. You can make no mis- take in buying Eveready Layerbilt No. 486 for any set using normal voltages (45 to 135 volts). You will be buying the utmost in “B”’ power de- pendability —the great- est “B” power operating economy — D. C. (direct current) inits purest form, Radio Batteries -they last longer f* which insures pure tone quality. With at hand, is vastly improving. Equip your set now with Ever- colder evenings radio reception eady Layerbilt No. 486, the greatest “B”’ battery ever built for radio. Manufactured and guaranteed by NATIONAL CARBON Co., Inc. New York San Francisco Canadian National Carbon Co., Limited Toronto, Ontario Tuesday night means Eveready Hom 9 P. M., Eastern Standard Time, through the following stations: wEAF—New York wsak—Providence WEEI-Boston wTac-—W orcester wFi—Philadelphia woRr-Buffalo woapn—Pittsburgh wro-—Washington wsal—Cincinnati WwTaM—Cleveland wwJ—Detroit wan-Chicago woo—Davenport i olis wooo | Rr Poul KSD—St. lowie

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An Endless Trackway Conveys Trains of Little Electric Cars from the Depths of the Diamond Pipe at Premic Mine to the Washing Plant in the Distance—See Page 818

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opular Mechanics Magazine REGISTERED IN U. S. PATENT OFFICE WRITTEN SO YOU CAN UNDERSTAND IT L NOVEMBER, 1926 “DANCAKING” down from a height of 2,500 feet, an airplane equipped with a fifty-foot parachute was landed safely at a California field recently in the first test of the biggest chute yet built. Blown three miles from the field during the drop, which took sixty-six seconds, the craft landed in rough ground on a hill, damaging the un- dercarriage and propeller slightly. With level landing ground, observers said, e ship could have rolled after landing nd escaped damage. The big parachute, designed by Harry . Doucett, a chief petty officer of the navy, did not differ greatly from the maller chutes used by flyers. It was fas- tened to the plane by forty feet of steel ible, and a four-point suspension at the enter of balance of the ship, just forward of the pilot’s cockpit. The parachute it- self, folded in a container four feet long and fourteen inches square, was carried in a compartment beneath the fuselage, back of the pilot’s seat. From the sus- pension point in front of the pilot the cable was carried along the top of the fuselage, passing over the flyer’s head, around the edge of the rudder, and for- ward beneath the airplane to the para- chute, being held in place by light twine which would break at the slightest tug. R. Carl Oelze, a naval-reserve pilot who was picked to make the first test descent, planned to climb to a height of 5,000 feet before releasing the parachute, but be- cause of motor trouble was forced to shut off his engine at half that distance. “At the height of 2,500 feet,” he ex-

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TOG plained after landing, “I cast a handful of newspapers into the air—a signal to my convoy of seven sister planes that I was ready to release the lever. I counted thirty, then I ducked and jerked the re- Because of air valves in the chute, it filled slowly but steadily and I was sur- prised and tickled to see the cable gradu- ally rise into position without the slight- est semblance of a jerk. “One thing I had misjudged. That was the velocity of the wind, and in giving the 25,000 spectators that lined the field every possible chance I had gone too far over into the wind. This put me past one ex- tremity of the field, and I soon saw I was going to miss. I did my best to steer for something, and made a pancake landing on a slight hill which demolished only my landing gear. ‘Wings, the parachute, settled down to ground beside me. Five lease. POPULAR MECHANICS minutes later the observers and spectator began swarming over the hill and tl emergency ambulance dashed up to fir me at a near-by house begging a gtass « water from a surprised housewife.” While the parachute was being teste on the west coast, an equally important aviation development was revealed in the east when Henry Ford took occasion, on his birthday, to exhibit a new “flivver” plane developed by the Stout metal-ai: plane division of the Ford company. The new ship, a tiny monoplane driven by a small three-cylinder air-cooled motor. i still in the experimental stage and it price and the details of its construction remain to be announced. Model of “‘Wings,”’ the Para- chute That Landed a Plane Safely, and, at Left and Be- low, Henry Ford and His New Flivver Plane, a Tiny Monoplane Powered with an Air-Cooled Engine Te J

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POPULAR MECHANICS Artist’s Sketch Showing How the Giant Parachute Brought an Airplane Safe to Earth After the Motor Had Been Stalled; the Chute Is Made of Finest Silk, with Strong Rope for Shroud Lines, and Steel Cable to At- tach It to the Ship; in Flight the Chute Folds Up in a Small Container

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POPULAR MECHANICS success recently by the Polish army maneuvers near Warsaw. The tank r sembles the ordinary military machine the type, but instead of a gun tu: ret carries two streamlined cor tainers on the roof, filled wit smoke - making chemicals under high pressure. In action th. tank advances first and lays dow: a thick screen, under cover which troops are able to advance and prepare new trenches or exe cute other evolutions. FIGHTING SNOWS IN ALPS TO CLEAR AUTO ROADS During a period of warm weather in Europe last season, there was on locality that not only escaped the heat New Form of Metal Traffic Marker Is Easily Driven In wave but experienced some or the rigor with an Air Hammer of winter. Heavy snows fell in parts o! the Swiss Alps and over the Fluela pas a aa drifts several feet deep being formed. I was necessary to clear the auto roads a! A new type of traffic marker for safety most daily and, in places, a narrow on: islands, or which can be used to spetl out way cut through the piled snow was t! speed warnings, school-zone signs and only means of getting in or out. similar information is built to last as long as the pavement itself. The marker consists of a square of heavy sheet steel, with corners bent down and buttonlike projections raised in its surface. It is driven into the pavement with a compressed-air ham- mer, and can be used on any type of asphalt or wood - block pavement. The markers are spaced a foot or so apart to form lines for safety zones and closer when used to form letters. TANK LAYS SCREEN TO HIDE TROOPS IN WARFARE An armored battle tank that shoots a smoke screen instead of » og : x. Summer Autoists in Alpine Passes Keep Cool Driving between Giant Snow- bullets was tried with banks That Line the Road; This Is a July Scene

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POPULAR MECHANICS 709 I ! ( the phonograph were being treated. Later, it covered that the an unusual hardness and more records could be stamped from them. At a dis- disks had was ¢ adside Inn on the Pacific Coast with Small Individual Bungalows Instezd of the Usual Hotel Reoms for the Guests; Spanish Architecture Emulates the Old Missions ROADSIDE INN FOR MOTORISTS HAS BUNGALOWS FOR ROOMS Small, individual bungalows, each with ate bath and garage, are the features mission-style hotels for motorists being ected between San Francisco and Port- nd. The little dwellings take the place ordinary rooms and the main building a large dining room, office and other ommodations of the usual hotel. The ngalows face a central patio. CHANCE FLIP OF BIT OF CHEESE IMPROVES PHONOGRAPH How an Italian laborer’s faulty aim with piece of cheese made a lasting contribu- nto the success of his employer, a man- cturer of phonograph records, is the told by a chemist of the bureau of ndards. During lunchéon time one the worker playfully flipped a lump cheese at a companion. The missile short and landed in a tank where me- disks used in preparing records for loss to account for the change, plant offi- cials conducted a careful inquiry to learn if the solution used with the disks had been altered in any way. The episode of the cheese came to light, and it was found that the casein the lump contained had produced the hardening of the metal. ELECTRIC LAMP FOR MINERS DETECTS POISON GAS Protection against fire-damp explosions is said to be afforded miners in an electric safety lamp a German engineer has de- vised. It through a small, semicircular loops of a special metal preparation placed in a little glass bulb which is sealed at its upper end by a por- ous Under conditions, with the current on, the ends of the fila- ment turn a dark-red color, indicating that l But if in the air, the center of the filament becomes incandescent to a operates series of stone. ordinary the lamp is working as it shoul > there is poison was varying degree, depending on the quan tity of the dangerous vapor present

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710 CAMP TENT AND BED COMBINED ERECTED IN TEN MINUTES Combined Tent and Bed for the Auto Tourist; It Is Assembled or Taken Down in One Operation For the auto tourist, tent and bed have been assembled into a single unit which is easily and quickly set up or taken down and weighs only seventy pounds. The bed frame is attached directly to the tent sup- ports and its canvas mattress is tightened with a ratchet and may be laced so securely that it will not sag even with two persons, each weighing 200 pounds or more, it is said. The tent provides space for dressing room and has side curtains with windows. ARCTIC GRASS FOUND IN U. S. LEFT BY GLACIERS Grasses found flourishing recently on the peaks of Mt. Massive and Mt. Elbert, 14,400 feet above sea level in Colorado. have been identified as belonging to species found along the Alaskan coast. The only explanation for their presence in Colorado, according to Prof. A. S. Hitch- cock, of the department of agriculture, who made the discovery, is that in the POPULAR MECHANICS glacial age the ice from the north carried seeds southward and left th stranded in the Rockies. Prof. Hitchcoc] is collecting and classifying the 1,500 species of grass in the United States part of the work of the government to- ward replanting the range lands in the west and controlling grazing. grass NEW HARD STEEL TO LOWER COST OF MACHINERY A new hard steel, which can be pro- duced at less cost than present alloys, r: cently was developed by a steel mill in the Pittsburgh district and given the name 0: “jalcose.” Its surface is extremely ha: while the interior is tough but ductile making it suitable for automobile and m: chinery parts where there is severe wea: repeated shocks or great stresses. Be cause of the comparative softness of the interior it can be machined more easil than pure hard steel. MOTORBOAT ON VENICE CANALS REPLACING GONDOLA Travel on Venice canals has been ma more rapid lately. by the use of small m torboats to supplement the tradition Some of the leading hotels ha their own craft to take guests to and fro: gondola. Taxicab Meters and Flags Are Used on Motorboa That Ply the Canals in Venice stations and for rides about the city, a! there are stands where the boats may hired like taxicabs.

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POPULAR MECHANICS IN AND SNOW FERTILIZE SOIL rain and snow do than water the soil een confirmed by dian chemists, who have measuring the from iir and brought to by them. They | that in the region nd Ottawa the fer- washed into the out of the air was ilent to forty-four ds of expensive ean saltpeter per each year. Dr. T. Shutt, Domin- hemist in charge of everal years tes absorbed experiments over a | of seventeen years, poke a good word he much maligned coal. Ammonium te, the form in which ertilizer comes from air, is given off by coal fires in large quantities. In- e in the use of the coal is marked by responding increase in fertilizer. For- and brush and lightning dis- rges also help. increase the ammonia ntent of the air. fi res VIOLIN IS PLAYED WITH KEYBOARD nelosed in a + dec- ive cabinet, a olin is played with kevboard similar to tofa piano. It is | that tremolo ef- can be ed by pro- merely ssing and releas- the right key, and eral instruments be combined and ed together, er with the keys The Side Wheels of This Motorcycle Are Drawn Out of the Way When Traveling, While Providing Safety on Sharp Turns SIDE WHEELS ON MOTORCYCLE AID IN TURNS AND STOPS \ two-seat motorcycle with small side wheels that can be raised or lowered by 7 the right hand, has appeared in means of a lever at driver's Paris. The extra pair rest- . ingonthe pavement helps hine ady the mac hen it is stopped, and reduces the dan- accidents on turns ver of comfort of the pas- senger in the rear is also increased the cvcle ‘an excessively. @ During year, 524 passed cannot the pa more through ) 7 Panama canal y means of rolls. With a Piano Keyboard, This Violin Can Be Played without Learning to Use a Bow in 1925,

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POPULAR MECHANICS / / Difficult Engineering Feat in London Nearing the Close; after Building a Large Subway Tunnel around a Smaller One, the Workmen Begin Dismantling the Latter While It Is in Use TUNNEL DUG AROUND TUNNEL WITHOUT HALTING TRAFFIC That engineers can accomplish the seemingly impossible has again been dem- onstrated in a subway alteration in Lon- don. The problem was to construct a siding between two tunnels on different levels without interfering with the trains that whizzed by every two or three min- utes. There was a difference of ten feet in the levels, the space between was nar- row and the ground contained pockets of water-bearing sand. Furthermore, junc- tion tunnels had to be made to connect the siding with the running tunnels. Most of the siding, except about 320 feet of lead-in section to the down-running tunnel, was bored by hand at practically the same level as the higher of the two passages along which the siding ran 720 feet. Air locks and compressed air were used to hold back the water in the sand pockets. While the junction tunnel was being con- structed, the running passage was literally a tube, supported at the base and sides with timber struts to prevent collapse as the earth was removed from around it. The workers thus literally dug a tunnel around a tunnel without stopping traffic inthe inner one. To keep the compress: air from entering the inside tube, the hol in the segments through which cement had been injected when the tunnel w constructed, were plugged up. When t outer passage was completed, the sides « the inner one were dismantled and t! props that had supported them were | imbedded in the concrete in which t! tracks for the new bore were laid. AUTO MAP ON STEERING POST READ AT A GLANCE Intended pr marily as a ct tificate - holder, metal frame f- an auto road m is fastened to t! steering just under t wheel so that t! guide may be seen at a glance while dri ing. A celluloid cover protects the m from the weather. co.un @Chimpanzees are about four times strong as a man, weight for weight.

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JN SNAPS A PHOTO OF THUG AS IT SHOOTS camera pistol that automatically takes ‘ture of the person or object at which fired has been invented by a mechan- engineer, who claims that, by the addi- of magnesium flash powder to the inary charge, the revolver can even » its photographic record at night. th it, he says, the picture record would ntify a criminal even if the bullet missed . while it would also be a positive rec- in self-defense cases, as the photo shuld show what the other person was do- ‘ when he was shot at. His idea is that camera case should remain locked, th the key in possession of the police lepartment, which would develop the films | hold the record. STORY OF HORSE’S EVOLUTION TOLD IN MODELS earch for the original hab- t of the horse is being con- ted by investigators of the ithsonian Institution. The % mal of today is believed & lave descended froma five- «| midget variety that iy have lived some- here in the Arctic gions. Dr. James Gidley has com- eted a series of dlels showing e supposed ‘lution of e horse. Dr. Gidley with Models That Tell the Story of the Horse’s Development from Early Ancestors; Scientists Are Seeking Animal's Origin POPULAR MECHANICS 713 Moth Balls Falling from the Press into Basket for Packing; They Are a By-Product in Gas Making CONDENSED GAS FROM COAL MADE INTO MOTH BALLS Naphthalene vapor, a by-product in the manufacture of gas from coal, is condensed and the flakes pressed into moth balls at an English works near The substance is collected in a condensation chamber which becomes covered on walls, floor and roof with the solidified vapor. The flakes are shoveled up and pressed in a machine which quickly rolls them into the familiar round pel- lets for home use. London. GERMAN AIRLINES INSURE PASSENGERS IN PLANES Every passenger who buys a ticket on one of the seventy-five Ger- man air lines is automatically insured for $6,000 under a new ticket system put in effect recently. The in- surance company which handles the policy decid- ed that flying in Germany was as safe as riding ona train, and charged merely the normal accident rate, instead of the extra-haz- ardous-occupation rate. No passenger w jured on German lines in the first half of 1926. as in-

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“Flying Cloud,” One of the Most Famous of Donald McKay’s Clipper Ships and the Fastest Sailing Ship under the American Flag, and,-on Opposite Page, the Latest Diesel-Motored Liner — ENTY-ONE years ago the first mate of the Boston-built clipper ship “Lightning” closed his log entry for March 1, 1885, with these words: “Distance run in twenty-four hours, four hundred and thirty-six miles.” That was a record that still stands. No sailing ship had ever sailed so fast and far in a single day, and it is improbable that one ever will. But the tramp steamers had already begun to chug their way across the seas and the clipper ship, the most beautiful thing seafaring men ever invent- ed, was already doomed, though but a half dozen years old. Today the steamers that drove the sails from the ocean are fighting another, and a losing battle, against man’s latest devel- opment, the motor ship. Like the steamer that displaced the clipper, it costs more to build than the losing boat, but it is cheaper to operate and can carry the world’s freight at lower rates. The clipper was born in the mad rush to get to the gold fields of California. Passengers paid enormous fares and the freight rates were gigantic. Under such conditions the long, narrow hulls, with 714 their somewhat limited cargo space, could pay dividends—and big ones—but when the world settled down to five and six-per cent profits, the clipper was doomed. The motor ship, with its Diesel engines burning heavy oil, has placed millions otf tons of shipping on the seas in the last six years for the same reason—surer profits. To Donald McKay, who came to the United States as a boy of sixteen from Nova Scotia, America owes the honor of sweeping the seas in the most glorious days of sailing ships. He built the fastest clippers that ever sailed; not one, but man) of them. The “Lightning,” which made her world’s record on her maiden voyage from Boston to Liverpool, was one of four clippers built by McKay at the same time for a British line which had ordered them for the Australian service. One of the quartet, the “Donald McKay,” only ship named after their designer, logged 421 miles on her maiden voyage that same spring. Another, the “James Baines,” sailed around the world, Liverpool to Liverpool in 132 days, a record no othe sailing ship ever equaled. The four were built after James Baines, the president o! ay

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? line, had leased McKay’s “Sovereign if the Seas”’—one of the finest ships that flew the American flag—and offered ein her hold at seven pounds per ton, shipper to recover two pounds if she n't beat every steamer on the run to \ustralia. Baines kept the money. What the speed of these fast clippers eant is better understood when it is real- | that no steamer afloat at the time uld have come within a hundred miles “Lightning’s” 436-mile log for twenty- ur hours—in fact, there are hardly fifty at passenger liners afloat today that n better that mark. In her log for that e t of March the first mate wrote, “Strong les, bore away for the North channel hey were then 500 miles off the Irish ast], carried away the foretopsail and t jib; hove the log several times and ind the ship going through the water at rate of eighteen to eighteen and one- lf knots; lee rail under water and rig- ng slack.” Her sister ship, the “James Baines,” was fast, though she never logged quite so iny miles in a day, but on one occasion ‘ attained a speed of twenty-one miles hour—a marvelous performance for a iit borne by the wind. McKay did not create the clipper ship, but he did bring it to perfection, and built the greatest clippers that ever sailed. Be- fore his day, sailing ships were small and broad and short, with bluff bows hammer- ing their way through the water, and squat, square sterns—a cod’s head and a mackerel tail was the shipbuilder’s model. McKay’s clippers were just the reverse, long and narrow, lean as a racing grey- hound, with both bow and stern concave at the water line-—the same flaring lines used for the racing cruisers and battle- ships of today. Above the deck towered lofty masts and giant spars, carrying a vast spread of can- vas. The “Great Republic,” of 4,555 tons, biggest of them all, had a main yard 180 feet long and her suit of sails consumed 15,000 square yards. She inspired Long- fellow’s poem “The Building of the Ship.” She was doomed, though, never to set them, for while she was loading at a New York pier for her maiden trip, after hav- ing been towed down from Boston, a waterfront fire spread to her sails and the ship was so badly damaged it was neces- sary to scuttle her to put out the flames. Raised again, she was cut down to 3,357 tons, with corresponding decrease in her 715

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POPULAR Donald McKay. the Nova Scotian Boy Who Made the Stars and Stripes Supreme on the Seas sail she area. In spite of the cutting down, made a voyage to San Francisco, around the Horn, in ninety-two days— only three days slower than the record. What she might have made as originally designed can only be conjectured. It was a McKay the “Flying Cloud,” that set the world’s record for the passage from New York to San Francisco. On her maiden voyage in the summer of 1851, carrying a cargo of gold bound to the she made the vovage in eighty- nine days, a record that was only equaled twice, by herself in 1854 and by the “Andrew Jackson” in 1860. On that memorable maiden trip she raced the noto- rious “Bully” Waterman’s “Comet” and beat it nineteen days. The “Flying Cloud” was not a ship, as later clippers went. She meas- ured 229 feet long on deck, with a breadth feet eight inches, and had registered tonnage of 1,783. Beneath her bowsprit a beautifully carved figurehead showed a winged angel blowing a trumpet. “ce ship, seekers coast, by big of forty a MECHANICS In a day when ship owners had alread begun naming their vessels after them- selves and members of thei- families, Mc- Kay's clippers not only were famous for their beauty and speed, but for the apt with which he named them, when wise owners permitted him to do thi From his yards came “Westward Ho” and “Star of Empire,” both for the Cal fornia service; the “Staghound,” “Ocean Monarch,” “Sovereign of the Seas,” “Bald Eagle,” “Chariot of Fame,” the Seas,” “Great Republic,” “Romance of the “Defender,” “Mastiff,” “Glory of the Seas,” and many others. Yet the first of his great clippers, the “Staghound,” was not launched until De- cember, 1850, and the last real clipper, “Donald McKay,” slipped down the ways in 1855. Into those five years a whole revolution in naval architecture was crowded. The four Australian packet ships, including “Lightning” and her three sisters, closed the era of extreme clippers. McKay continued to build medium clip pers, broader of beam and with smalle masts and sails, until the Civil war turned him into a gunboat constructor of tl navy. After the war he turned out three more medium clippers in 1868 and 1869, but already the market for the wooden hull to be sailed by iron men was passing. The change from sail to steam was fair] gradual. The clippers went within a fe years in favor of slow- er*ships with qual. | { ; | ' ness “Empress of Seas,” Model of “Lightning,” a McKay Clipper That Holds the Record as the Fastest Ship That Ever Sailed

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POPULAR MECHANICS ng Way from the Stately Masts and Billowing Canvas of Clipper Days; This Is the “‘Leviathan,”’ Queen of the American Merchant Fleet, Leaving New York at Night t capacity, or else had their masts of good and cheap coal, while the change iil area cut down to makethem more has been much slower in England. The smical in operation—as happened to British, however, have built several no- famous “Cutty Sark”—but it took table motor vessels, one a big passenger years or more for steamers to really ship that runs between western Canada lant the wind. The new shift, from and Australia, and two others for the Eng- to motor ships, has started at a land-South American trade. rapid pace. Italy, iny and the Scandi- in countries have led, x tly because of the lack a The Wind May Again Move the World's Commerce, but White Sails and Lofty Masts May Be Replaced by Squat Rotor Towers as on This German Ship ms tf | ' ’

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POPULAR MECHANICS Ordinary Rear-View Mirror, and Below, Glare- proof Glass That Keeps Dazzle Out of Eyes GLAREPROOF MIRROR FOR AUTO MAKES NIGHT DRIVING SAFE To eliminate some of the dangers oi night driving a glareproof, rear-view mir- The backing, which is prepared by a secret process, does ror has been developed. away with sun, snow and headlight glare, and increases the mirror’s effectiveness for use. daytime Images and are sharp, clear, well defined, as in a camera finder. The objects seen are in their proper col- ors, and appear at their actual distances. This last feature is particularly valuable, as it permits a driver to gauge accurately how far behind cars are. SCHOOL FOR DOCTORS ON TRAIN GIVES HOSPITAL POINTERS What would a surgeon do if the lights were suddenly extinguished while he was working on a _ patient When is an in the operating room? “ashes of roses” color best suited to the walls of a sick room and when is orange most effective? How can a physician tactfully induce a mother to quiet her children who may be laughi and shouting in a sick ward, disturbi the patients, and yet not lose the woman’ good will? These and other problems re lating to hospital management and proc: dure were studied on a train carrying de gates to the American hospital conventi at Atlantic City. posed of doctors from various parts oi the country, and experts in that particu- lar field of medical work were obtained t give the instruction. The classes were co) The plan not o1 proved a satisfactory employment of spa time, but the questions and studies we related to matters discussed at the con- vention and subsequent hospital visits. ONE-MAN “SODA FOUNTAIN” WALKS BELGIAN STREETS In cities, the version American soda fountain is the cocoa vei der, Belgian of who tours the streets and serves customers in the open. The cocoa ped dlers carry a pair of tanks slung to the one filled with cocoa and the other the latter for glasses, of which each vender has two, t! limit customers he can time. The faucets of the two tanks carried around under venient position. backs, with water, rinsing t of serve at o1 his arm to a co Belgian One - Man Soda Fountain That Carries the Drink Direct to the Cus- tomer on the Street

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POPULAR MECHANICS 719 TINY FIREBOAT PROTECTS SUMMER-RESORT HOMES problem of securing fire ion around lake resorts to have been efficiently and iically solved by a small it recently developed by a rner. The boat has enabled lider and owner to establish lf in a business in which he a substantial sum during a n of four months. Lake re- where people have summer One of the World’s Smallest Fireboats Is an Outboard-Engined Skiff Maintained for Summer Residents at a Western Lake; the Motor Pump Can Be Carried Ashore to Fight Forest Fires mes and cabins are usually situated in teen feet in length, and driven by a rested country. Such locations seldom two-horsepower outboard motor. In this e adequate fire-fighting equipment. hull was installed a high-pressure fire onsequentiy, during seasons of scanty pump, with a fifteen-foot length of suction niall, the fire risk is great and full fire hose, and 1,000 feet of two and one-half- surance prohibitively priced. This con- inch fire hose. The pumping unit weighs stay n is particularly true in southern Cali- a little over 100 pounds and the fire hose rnia where the summer months are vir- only a few ounces per foot, so that the lly rainless. The danger from fire at total load carried in the boat is by no h resorts, as observed by Frank Lewis, means excessive. The boat can speed Los Angeles, set him thinking of ways around the lake at from six to eight miles which the large property investments an hour, and can throw water on any fire und the lakes might be protected. The originating within 1,000 feet of the shore. boat shown in the accompanying illus- Each owner pays for fire protection on tions is the result. And; in conjunc-_ the basis of $1 on each $1,000 valuation with it, he has developed a novel of the property. While this rate is cheap iness plan whereby the owners whose for the owners, it nets the fireboat man an perty he protects pay on a monthly _ easily earned addition to his income from scription basis. The boat is only six- fishing, which is his regular occupation

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POPULAR MECHANICS a An Unusual Feat in Animal Training, Breaking a Team of Zebras to Pull a Cart HARNESS-BROKEN ZEBRA TEAM SHOWS TRAINER’S SKILL Few animal trainers have been able to teach zebras tricks because of the vicious disposition of the animals and their un- reliability, but a policeman in Golden Gate park, San Francisco, has tamed a pair un- til he can drive them as a team harnessed to a light rig. The beasts are owned by the park and attract considerable atten- tion as they canter along the roadways. RELICS OF MAKE-BELIEVE LAND REFLECT STAGE HISTORY In a large building on one of New York’s busiest streets is housed one of the most romantic museums to be found any- where. It is the storage place for the properties of some 800 theater produc- tions. Rusted poniards and masks, dusty furniture, modeled carefully in historic styles, costumes, gilded odds and ends and even an assortment of imitation bathtubs are collected here, evidences of past glories before the footlights and proof of the amazing ingenuity and skill required to entertain the public. <A portion of a lo- comotive set, one of the high lights in a famous production, models of yachts, col- lections of guns, Roman chariots, busts of noted persons, and replicas of art objects are included in this historic array ~ ) As a reference source, the col ec ae tion is considered valuable, as many of the chairs and tables, for instance, were exactingly copied from originals and strange customs and fas] ions of departed days are reflected in various articles. Dampness - proof things are kept in the cellar fF \Y¥; TANK ON REGISTER KEEPS PROPER HUMIDITY To insure the proper humidity of room interiors, a water shield for hot-air wall registers has been found practical. Besides keeping the air moist, it deflects the heated current toward the floor, thereby aiding in main taining an even temperature. A collects dirt to protect the walls and drapes. Less heat is required when th: air is sufficiently humid so that a savii in fuel can be effected with these shields screen

St a ah

Water Chamber Built to Fit over Hot-Air Register ' Maintain the Correct Humidity Health is promoted as dry air tends to « crease the moisture in the breathing p sages, exposing them to infection. 1! attachments are made of oxidized copp¢ held by adjustable wire hooks and can put on or removed without the use of too

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POPULAR MECHANICS — When the Guns of the “‘Nevada” Were Fired over the Bow, the Force of the Fire Caused the Vessel to Plunge like a Great Whale; to the Amazement of Officers, Little Damage Was Done BATTLESHIP FIRES DEAD AHEAD BREAKING NAVAL CUSTOM shattering a naval precedent held in all great fleets of the world, the U. S. battleship “Nevada,” in practice not long fired her main batteries dead ahead. Vhen the shock had subsided and the ship brought to, it was discovered that, beyond roken porthole glass and slightly strained ninor bulkheads, the vessel, one of the ldest dreadnaughts in the navy, had sus- ‘ined the terrific test without any damage hich would have prevented continuing battle. The big guns are not fired dead ver the bow or stern because there is pat h of recoil \\ when they move their line at right angles across the antagonist’s fleet. Shortly be- fore the “Nevada” began the test, all hands among the turret crews were informed of what was to happen. A few points were fired from the starboard bow, the reaction shaking the ship violently. ‘lhe next shot went directly over the bow. The “Nevada” lurched and buried her bow in the water rising like a great whale, then recovered. TWO-TONE AIRPLANE SIREN AIDS IN LANDING As a warning when landing at night and to attract attention when the craft is used for advertising pur- the explosions. he ship must ab- orb the recoil vithin itself. Ves- Is may fire to port starboard be- iuse the ship veers over to the side posite the firing. his roll of the ves- absorbs the re- il energy. In this the primary ison why modern siren that produces two tones poses, a and is driven by air, proved tive. It heard at a has effec- can be consid- erable distance even above the [ roar ot the propellers, ac cording to reports, and is easy to at- tach or remove. @ The eves of a fly ets attempt to ’ the enemy line Siren and How It Is Attached to the Plane; It Shrieks a Two-Toned Warning as Craft Descends are as rigid as jew- els in a watch.

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Eskimo Hunter Keeping Watch at a Seal’s Blow Hole HAT civilization may have furs of amazing fineness, the crews of the polar fleet yearly face the nazards of the vast ice and snow wilderness of the Arctic regions for months on end. Desolation and mo- notony are everywhere and possible death stalks beside them as they travel through uncharted channels or cross treacherous ice packs in quest of those animals which wear pelts so prized by Dame Fashion. While polar expeditions, using the lat- est scientific and mechanical means of transportation and communication, have penetrated the vast icy hinterland to the heart in search for new lands gripped by the big ice pack, the fur fleets have been putting forth greater efforts than ever to gather the rich harvest of furs known only to the Arctic, and by their persistent penetration have lifted much of the veil of mystery from these desolate and re- mote regions. This is especially true of the Canadian Arctic, where fur-fleet vessels now cruise far along the northwest passage, in search of which the famous Franklin expedition of 1845 perished. Though Amundsen’s expedition of 1903-06 was the only one to 722 travel all the way throug! this treacherous passage from Atlantic to Pacific, yet other vessels have penetrated deeply and re turned with a cargo of furs worth a king’s ran som. The polar fur fleet has recently pushed way from Alaska to Kin: William’s land and Bath- urst inlet, making cor quests of passages whic! a generation ago wou! have -been- considere: credit -to any polar ex- plorer, but-which the masters of these schoon- ers look upon as but a part of the day’s toil They make a profitable round trip along these subpolar coasts the short summer season when the ice | moving, permitting small vessels, rigid built, to make the passage successful! Here are found some of the world’s ric! est peltries, since this is the home of t! rare seal, the rarer white fox, and t! rarest of all “water-babies,” the sea otte1 Herschel island, a noted whaling ) in days gone by, is the principal port the western Arctic, and here new activiti have been taking place in the race for f away peltries in recent times, under lash of the popular demand for these r furs. Recently six new auxiliary scho: ers and steamers were making their sl: way through Bering strait, ready to « at Herschel just as soon as the ice lo ened. Those rich peltries of the east: Arctic region, Hudson bay and Baffin lai are reached by Atlantic schooners leav! Montreal and Halifax early in the su: mer, returning before the ice seals t waters for the long winter. In the first few days of March, follo ing a practice that has prevailed for so: 200 years, the Newfoundland sealing { leaves the port of St. Johns for the Ban

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its annual expedition into the Arctic. ne ten or a dozen vessels set forth on s romantic and, at times, hazardous ex- ‘dition; and what a thrill must face these vatchers for swills,” as they call them- selves, as they gaze across vast ice floes lotted with “white coats” as far as the e can see, which testify to the assertion it the famous seal herds off the New- uundland and Labrador coasts are on the ncrease even in face of the growing de- inds of civilization. (he sealing industry, exploiting the rich resource lying off the coasts of the island, one of the most ancient of the economic tivities of Newfoundland. It was start- ed in 1763, when the first expedition ven- red forth. \lthough arctic fur schooners, because the hazards of polar ice floes, are of necessity small, the vessels engaged in the ealing industry have been considerably lernized. The sailing vessels became rger year by year until they were almost tirely superseded by fast steamers, hich facilitate the methods of the seal int. Now, though there are a few sail- vessels in the expedition, the steamer is the most important factor and accounts for four-fifths ef the catch. In recent times, the annual seal expe- dition has been further brought up to date by the use of the aeroplane and radio. In olden times the herds were located by men in the rigging of the sailing schooners with a limited range of vision. The plane now does this “spotting” for the entire fleet and short-wavetransmitters broadcast the exact location and probable number of animals in the various herds. One of the common sights in the polar regions is a ship in the grip of the great ice pack. seal Deserted schooners are found often by the fur fleet crews “hove-out,” or thrown on their beam ends, clear out of the water, because under them. solid ice has formed Or, the polar schooner may be caught in a moving channel of ice and crushed to pieces, forcing her crew to take to large ice cakes, leaving them stranded many miles from starvation. When the ‘stranded” or ‘ assistance and tacing becomes ‘jammed” in large ice floes and is frozen in, polar schooner ‘ if the crew toil persist- ently day and night, they may save their

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724 POPULAR MECHANICS

< © Keystone View Co. With Rigging Shrouded in Ice the Vessels Must Battle Constantly to Overcome the Effects of the Cold ship and their lives. Then it is that they cut a channel to the open water from the “standing edge,” or from the edge of the permanent ice that lies all winter in pro- tected spots. They chip and bore with chisels and pike poles, and saw ice into large blocks, which are forced under t} ice field until a channel is made to ops water. Arctic travel is still a hard problem eve: with the present rapid advance in metho: of polar exploration, including the use « airplanes, dirigibles, snow motors and oth: devices up to date or even dated a litt ahead, with which arctic expeditions a: now equipped. Capt. Roald Amundsen late schooner “Maud” still compels admi: ation for her stanch resistance to the bui feting seas and grinding ice packs. No known as the “Baymaud,” the old “Maud is a part of the famous fur fleet of the Hudson’s Bay company, and is used in the western arctic trade. The “Friendly Arctic,’ as Stefansso: terms it, has proved none too kind to th: Hudson’s Bay fleet, for their schoone: “Lady Kindersly” was nipped in the ic pack near Point Barrow, and had to be abandoned with all her valuable cargo o supplies and trade goods for posts fro: Herschel island eastward. A year late: the “Bayeskimo,” operated in the eastern arctic, was caught in the ice of Hudso: strait and lost with her cargo while on he:

© Keystone View ‘¢

Icebound in a Far Northern Bay, the Ship Waits for the Floating Bergs and Fields to Move Out of the Harbor

Entrance; There Is Constant Danger of Being Crushed by the Ice

*

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POPULAR MECHANICS 725 , , to Hudson bay, and the crew rescued ” F m an ice floe on which they at last taken refuge. (he large fur companies are not alone considering the polar regions their ppy hunting grounds, although the idson’s Bay company have now pushed eir way from Atlantic to Pacific, and eir trading schooners make thousand- le trips through these formerly un- arted waters. Many of the Eskimos ive become rich from the sale of furs to a Ozark mountains and other parts of the coun- try. Some men have taken as many as fifteen and twenty trees in one season in Arkansas. As each tree yields forty-five or more pounds of honey, which has a ready market, the work of the bee hunter is often well Catching the Swimming Polar Bear, Overtaken in Open Water, and Hauling It Aboard; Right, a ther Bear Angrily De- } fending Her Cub as ‘the Boat Approaches rewarded. Keen evesight is a_ dis- tinct advantage, ex- he traders and now ve their own sthoon- perienced bee men de- clare, since it enables the hunter to detect the line with auxiliary gasoline engines. © Keystone ViewCo. of flight from the baited hive to the ut despite short summers and long se- tree so he can follow the insects. Journeys vere winters, when the thermometer drops of several miles are often made by the ers, some of them equipped fiftv below zero and terrible blizzards bees from their own nest to the lure which ww, there is in “ke veins of the members _ has been placed for them. Some hunters i the polar fur tieets an irresistible at- beat tin pans or ring cowbells to attract traction for these desolate regions. the bees as they are swarming from their : tree so that they can capture them and add ABSENCE OF FEAR IS VITAL the colony to their own apiary. Experts TO BEE HUNTER those endowed with a natural “feel,” are able to hive a wild swarm without | Good vision and an absence of fear con- using mask or gloves. A feeling of cot tribute largely to the success of bee hunt fidence and a total absence of fear are said ts who follow this unique activity with to be the best assurance against being nsiderable profit and enjoyment in the — stung by the bees.

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POPULAR MECHANICS New Tests of Skill for Archers and Surf-Board Riders Are Afforded in the Latest Beach Game, Shooting Arrows at Floating Target from Aquaplane; Riders Must Also Display Teamwork ARCHERY FROM SURF BOARDS LATEST BEACH SPORT Aquaplane archery is one of the latest diversions on a California beach. Two persons ride on a surf board behind a mo- torboat, one to steer and hold the plane steady, while the other shoots arrows at a floating target supported on pontoons. Skill is demanded of both archer and com- panion to score a hit. DETACHABLE SIDECAR ON CYCLE SERVES AS BOAT For outing trips, a motorcycle sidecar that holds two passen- Double-Purpose Motorcycle; the Sidecar Is Quickly Transformed into a Boat When Detached gers, may be detached for service as a boat It is shaped to cut through the water wit! a minimum of resistance and may be used with an outboard motor or oars. Only few minutes are required to remove it put it back. MAPPING ALASKA FROM THE AIR UNCOVERS NEW RICHES Unsuspected wealth in water power and timber supplies has been discovered i Alaska by cameramen engaged in makin an aerial survey of the 25,000 square mile of territory in the southeastern sectio1 Near Ketchikan, for instance, a networ! of hitherto unknown lakes has been re vealed and a single valley there, enginee! estimate, will be able to deliver 85,00 horsepower in one large hydroelectric sys tem, promising development of pulp an paper mills. Several rolls of film sufficient for thousands of feet of airplane mosaic have been taken. The entire task is ex pected to require four years. The burde: of the expedition this year was borne b) the navy, with twelve different govern ment bureaus watching and assisting wherever practical. The actual mapping was done from two airplanes. A third

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POPULAR MECHANICS ed with radio and stant communica- ith the others, re- at the base, pre- to take off at a mo- Carrier s were taken on nger flights, but of used only a young n its first flight re- The two planes, notice. Pe e n line at of 10.000 an alti- feet, “la strip nearly 100 ong and fourteen ide in an hour, as camera photo- l about miles wide at one re with its three The craft are hians, equipped for on land, ice or used by an area 1 . nd were Comm. Richard E. luring his prelimi- lar flights in 1925. heels fit into a et arrangement when is in the air or ater and the motor atford | piane ranged to ter power and better ication. The map- expedition is con- ered by some persons fully as spectac- is the dash over the pole. The region unds in mountains from 10,000 to WOO feet high. The rougher parts of ountry have defied land surveyors and bermen. Many of the small islands practically inaccessible as they are rounded by ice floes from the glaciers. » region is noted for its heavy rains. DOUBLE SAW TO CUT NOTCHES SAVES CARPENTER TIME Intended especially for cutting notches in joists, a double - bladed saw is said to do rapid and accu- rate work. It in- uniform width and even saving extra sawing and measuring. a slot oft Floodlighting at Night Brings Out the Decorative Detail Until the Building Resembles a Gorgeous Temple Set in the Sky LATEST IDEAS IN ARCHITECTURE EMBODIED IN SKYSCRAPER What is regarded as a step forward in architecture is seen in the new telephone building in San Francisco and in several other large skyscrapers of recent con struction. Many precedents have been set aside. For instance, all “sides are front and all tance,” boundaries are of equal impor so that the building dominates the from proached. \ tion has scene whichever point it is ap- ninute scheme of decora been followed, calling for the application of creative art. he cost about $4,000,000, has twenty structure six stor ies and is 436 feet high trom the pavement to the base of the flagpole. An elaborat« system of floodlighting at the top makes I the building look at temple set in the sky. night like a fairy

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POPULAR MECHANICS in hundreds of relics have been picked u various parts of the from graves, sites of villages and mounds is estimated that m than 20,000 copper jects have been collec: The most primitive t were employed to the ore. These includ stone hammers an mauls for breaking up the rock, wooden we paddles and shovels removing the loose and crude wooden | and levers for lifting t] ore out of the pits. F: the mines, the copper carried by canoe, o1 foot over the Indi trails, to the villa; where it was manui tured. Apparently objects were fashion¢ by hammering, cutt Some Radio Fans May Tire of the Programs, but Hospital Inmates, Especially the Children, Are Always Pleased with Wireless Hour RADIO PROGRAMS IN HOSPITALS HELP PATIENTS RECOVER Physicians declare that radio is of great benefit in hospitals as it takes the patients’ minds from their illness and develops cheerfulness. Children, particularly, en- joy the concerts, and the story hours are as popular in the sick wards as in the homes. In England, here and in other countries, many hospitals have been equipped with complete receiving outfits, including loud speakers and headphone ets that may be plugged in at the bedside without disturbing others. Several insti- tutions for soldiers have been fitted with radio through the generosity of the public. COPPER MINED BY INDIANS FOR TRINKETS AND TOOLS Many years before the great smelters of today were in operation, Indian tribes of Wisconsin had learned how to extract copper ore and were pounding it into tools and ornaments. Evidence of this is found and grinding the The attractive color the metal was its c virtue to the Indian, aside from its eas: preparation, and investigators declare t! the Wisconsin tribes did a brisk busin: in copper with other Indians not onl) the east but that they traded as far south as the Gulf of Mexico. SHARPENER FOR RAZOR BLADES WHETS ANY STYLE All kinds safety - faz blades ca! sharpened i leather-lined cer-shaped rangement th held between thumb and fing: the blade being serted in a narrow slot. Pressing the s! of the clamp together and tilting the ra: edge slightly upward, smooths the blac minute teeth back into alinement. A t! coating of dressing applied to the ja preserves them and improves the blad:

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POPULAR MECHANICS ETAL DIRIGIBLE FOR NAVY TO MAKE LONG FLIGHTS ng hydrogen instead of helium, the etal dirigible for which contracts been let by the navy department, is cted to have a cruising radius of 2,200 and will carry twelve persons includ- a crew of four. The craft will be it one-fourth the length of the “Los eles” and have but one-twelfth the gas city. Its diameter will be fifty-three at the widest point. A corrosion- isting coating will be applied to the side. Two gasoline motors, of 200 epower each, will give the dirigible estimated speed of seventy miles an The operating car will be built as ntegral part of the keel instead of be- wung underneath. MOCK GRAVES BY BOULEVARD HELP TEACH SAFETY ombstones with sarcastic epitaphs, de- bing the fate of imaginary victims ried below, are intended to spread the Saving Searches in Dark Interiors, This Revolving pel of safety first among motorists who Closet Rack Holds Many Articles a service station on a California ROTARY STEEL CLOSET RACKS tlevard. The legends emphasize some the commoner sistas Davies make SERVE AS DUMB WAITER | indicate the disastrous results that Troublesome searching for articles is seldom will follow them. eliminated in a revolving set of racks to lighten household duties. There are two separate fixtures, each rotating independently and fitted with an assortment of hangers, baskets and shelves for a wide variety of goods. Instead of hunting through a dark room, the user has but to turn the racks about un- til the article desired is found. Placed between rooms, the arrangement ail may serve as a dumb- waiter, saving steps from kitchen to dining room, for instance. The instal- lation is suited to dust protected closets and is placed high enough above the floor to per- mit easy cleaning. Mock Graves with Sarcastic Epitaphs outside a California Service Station Teach Driving Lessons

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POPULAR MECHANICS Learning to Putt with Aid of the Guide; Club Moves Correctly through the En- tire Stroke GOLF-STROKE GUIDE FOR PUTTS HELPS IMPROVE GAME Skill at putting is considered one of the most important assets of a good golf player, and to develop proficiency in this phase. of the game, an adjustable appa- ratus for the beginner or the experienced player is said to demonstrate the essential principles of the correct stroke in a few moments. Exercising with it is intended to familiarize the user with the proper position for the club at the moment of striking the ball and as the sphere rolls away. In the machine, the putter is moved through the entire stroke in the correct manner, as it is adjusted for such action irrespective of the user’s swing. Special shots are also demonstrated with the rigging, which can be set to suit the person’s strength. It follows the idea the baseball player has in swinging three bats to come through faster with one. FISHING FOR SILK Many precious articles such as gold, coral, amber and pearls are obtained from the ocean, but few persons know that some of the finest silk in the world is given up by the sea. In certain parts of the Mediterranean, is a species of mussel, with shells about three inches broad and seven inches long, and each of them con- tains a small hank of delicate fiber. At first glance it attracts little attention, be- ing soiled with mud and the remains of marine plants, but when it is washed and combed, the fibers are seen to be extreme- ly lustrous, glistening in the sunshine in shades varying from a golden yellow to olive brown. Only workers specially skill- ful are engaged in the spinning process, yet once this is done successfully, the yarn may be woven into shawls and wraps, stockings, gloves and neckties as well as dresses, hats and laces. In its natural state, the mussel silk is so much sought after that it commands a high price. ENGINE FOR WASHING MACHINE IS STARTED BY FOOT Motive power for the washer or for various light machines in the shop is fu nished by an air-cooled gasoline engine which combines several special features. One is the starting mechanism, a ratchet- controlled foot lever which turns the e1 gine over several times with a stroke. Another is the governor, built into the flywheel. It actuates two elec- single Close View of the Engine, Showing the Starting Pedal, and as Adjusted to Washer

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POPULAR MECHANICS il contacts to open ose the circuit to the rk plug. When the d exceeds the proper _ the governor draws points apart, break- the circuit and caus- the engine to miss. e motor takes up but e room and consumes mall amount of fuel. FRESH-EGG TESTS FOR HOME llow to tell a fresh egg m one which has been red or which for any er reason may not be to standard is re- ealed in a recent bulle- of the Pennsylvania te college poultry ialists. A fresh egg, they say, should have a ind clean shell and - a dull “bloom,” or dull luster. The that has been held some time, particu- where it may have en heated, will show a ided gloss. This is very noticeable on rtially incubated eggs. A mottled shell metimes denotes age. If decomposition ; started within the egg, the shell some- es shows a grayish tinge. Shells that re stained usually indicate the eggs have n in contact with moisture and are, erefore, of inferior quality. Eggs that have been preserved in water glass or lime \l show a roughened shell, because some f the chemicals adhere to it. An egg that has been washed with acid will show a very porous shell, and processed eggs are usually detected by their oily or waxy ap- earance. A fresh egg, when opened, hould have the following characteristics : he yolk should stand up well and have a ‘finite shape, the white should hold to- gether well and show a thick viscous con- tency near the yolk; there should be no lisagreeable odor, and thé white should have a “runny” appearance. In ad- lition, a fresh egg will cook in any man- without falling to pieces. “Skiing” across the Water; Balanced Boats for Each Foot Simplify the Stunt and Poles Help in Propelling and Steadying SKI WALKING ON CALM WATER LATEST OUTDOOR SPORT Water skis devised by a German inven- tor are like small boats strapped to the feet and are so balanced that they may be used with ease and safety when the weather is calm, according to reports. Poles help the wearer propel and balance himself. VISE FOR BENDING SMALL PIPE SAVES TIME AND LABOR One-half or three- quarter-inch pipe may be cut, thread- ed and bent with- out removing it from a special vise now on the market. It is adjustable for bending downward or sidewise, is said not to flatten or kink the pipe, and requires no special skill to operate.

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POPULAR MECHANICS found, through the scales } that keep a constant rec- ord of the hive weight. 1 that during the ear], morning there is litt nectar brought in, after the sun is well the hive weight beg to increase and keeps on growing until sunset when it stops abrupt! The chart of the record ing scales shows plain! the flight of the bees they leave and their turn with a cargo of n¢ tar. The weight creases fastest duri: bright sunshine, growth stopping sudde: ly for any sudden cl or rain. The use of t camera to keep the br. record has ended the | borious process of count ing each cell and avi chilling the bees. bees store surplus hon for their owners during only six weeks of t year, so the department © Harris & Ewing is experimenting to fi Bee Keeper at Government Experimental Farm Photogravhing a Hive as the way by which t Latest Method of Getting a Quick Brood Count : brood of workers can be CAMERA COUNTS BEES WHILE brought to maximum strength just befor SCALE WEIGHS THEM the six-week period starts, insuring a lat surplus crop. Using a camera to record the number of brood celis in a honey beehive and a fine registerin cale to keep constant MOTOR COAL SCALE INSURES > registering scale keep const: check of their eight hour by hour as they HONEST WEIGHT bring in the nectar, govern- Customers of a German coal compat ment scientists are fast svs- are assured of obtaining the exact amount tematizing the work of the > Nerdy they order by means of a special set bees. Through their record- scales attached to a motor truck. ing apparatus they obtain balances are driven to the house where t data which, when : coal is being unload checked with the iam : and as each basket weather-bureau_ rec- i : af m weighed, the pounds ords, show the influ- = Ps Da automatically record: ence of sunshine, 6, # by a stamp ona st! clouds, dry air, high of paper. The humidity, heat, cold am as = : » * 67 weight is calculat and other factors on — —e ~~ by deducting that the gathering of the baskets or b -. ee aye scale Car for Weighing Coal in Germany; Balances ..4.;.:.,, Wipe hon y- ney have Are Installed in Rear and Weigh Automatically containing the ¢

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BEI CTRICITY FORCES FISH TO USE SAFETY LADDERS the Charged Rods; Shocks Drive the Fish from the Danger Area int the Ladders That Lead Downstream

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734 ‘POPULAR MECHANICS Fane Tam Oe ee ee ae Ae ~S > ae Carma - UA tal YY can be dropped on a stone floor without break. ing and can be destroyed only by crushing. The material is said to be a good heat conductor and has a variable electrical resistance so that it can be used as a heat ele- ment. It also resists chemical reactions of various kinds. Hollow tile, and tubing with a thickness of only inch, have been made from it, yet it has great mechanical strength and a high degree of elas- ticity. A ribbon of the substance can be wound into a spiral, bent to sharp angles, yet will not break. So far, it has been used for fashioning tiles, muffles, tubes and similar hollow articles that have to be exposed to high temperatures a: well as insulators for Putting a New Twist to the Staid Old Ferris Wheel; the Cars Slide Twelve Feet at Two Points in Each Revolution SLIDING CARS ON FERRIS WHEEL PRODUCE ADDED THRILLS Some of the thrills of a toboggan slide are enjoyed in a type of Ferris wheel with cars that slip down a twelve-foot runway at two points in each revolution. They remain swinging until the next slide. The wheel is fifty feet high, weighs twenty-one tons, and each of the six carriages holds fourteen persons. | NEW CLAY AND METAL MIXTURE ) AIDS ELECTRICAL WORK Useful particularly in the chemical and electrical industries, a new substance pre- pared from fine clay or refractory oxides with a metal reinforcement by German experts, has peculiar properties. After firing, it becomes hard so that it gives out a ringing sound if struck. It resists sud- den changes of temperature. Bricks made of it can be heated red-hot and thrown into cold water without cracking, They llc crucibles and the Apparently, the combi- nation of metal and clay by this process is not merely a mechanical one. INLAID WOODEN BOX CONTAINS ELEVEN THOUSAND PIECES Spare time for a period of twelve years was devoted by an Italian cabinetmaker to the fashioning of an inlaid wooden treas- ure chest, a foot square and eight inches high. It is made of five kinds of wood and contains 11,968 separate pieces. _ ee eaarrerrreet J Inlaid Treasure Chest with Its Th wY sands of Pieces in Intricate Desig» = | wae: “Ee. t,” Sa ee SI

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POPULAR MECHANICS i) PAN 2... ES ve : J. bhi i | 4 Perpetuating American Marine History in Models; Replicas of Famous Ships Fashioned in Realistic Detail for Collections; Models of the “‘Santa Maria,” the “Constitution” and the ““Mayflower” Have Been Made SHIPS THAT MADE HISTORY ARE REPRODUCED IN MODELS Several vessels that have helped to make erican naval history have been realis- lly reproduced in accurate models by » New York craftsmen. The collection ludes replicas of the “Constitution,” the \lavflower” and the “Santa Maria.” The lders were metal workers and cabinet- kers before turning their talents in the ection of ship models. SPIDERS ARE GOOD MECHANICS IN BUILDING WEBS Spiders use plumb lines, struts and guy ires with skill that rivals that of an ex- rienced engineer, according to the ob- rvations of a French naturalist. He de- led that their cunning could not be plained on the ground of mere instinct it revealed an ingenuity akin to intelli- nce. This was shown by the fact that ch insect had a different way of making | For instance, after the web had been started by dropping a plumb line to e the spider the sense of the vertical ine, an obstruction was placed in such pairs. a way that the web sagged. The spinner sought to repair the damage by means of struts and braces arranged to pull the fibers back to position. But not all the spiders, not even those of the same va- riety, proceeded with this adjustment in the same manner. FOLDING CANVAS CAMPING PAIL SERVES AS MINNOW BUCKET With a capacity of eight quarts, a col- lapsible canvas pail with a metal bottom Pail Extended and Collapsed for Packing; Side Braces Keep the Canvas Rigid can be folded down to an inch in thick- ness. It may be used as a minnow bucket and for many other purposes on outings.

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736 POPULAR MECHANICS OCEAN TEMPERATURE ON COAST RISES FIFTEEN DEGREES Always a source of perplexing mysteries, the sea has presented a new puzzle on the Pacific coast by a rise of fifteen de- grees in temperature. \ ship captain made the di covery while sailing Oregon and Washington and also found evidence b> of an inshore current which had to be reckoned with in steering. question has now arise: will this warm flow permanent or is it just temporary result of some great earth movement o: the sea bottom? An season in Alaska w noticed as one of the sults of the warm current and fishermen report: variations in their cat p because of the change the temperature of t! ad Christening the “Cyclops” the Army’s Giant Bombing Plane; Engineers Pre- water. The effect of c1 dict That It Will Be Able to Make Trans-Oceanic Flights F 2 : rents on climate is no SINGLE-ENGINE BOMBING PLANE | ticeable elsewhere. Oslo, the capital TO FLY TWENTY-FOUR HOURS Norway, is in approximately the same la‘ tude as the southern part of Greenland Christened with a bottle ofgingerale,the but instead of being covered with an U. S. bombing plane “Cyclops” has been cap, that country is fruitful and populou added to the army air service. This single- This is due to the warm Gulf stream whi motor ship w eighs 17,000 pounds, has 825. washes the shores of northern Europe horsepower and is designed to carry 4,000 pounds of bombs over a cruising time of ELECTRIC FREIGHT-CAR PULLER DOES WORK OF SIX MEN eight continuous hours, or can fly twenty- four hours without ammunition. It planned to install a 1200-horsepower is In the operation of se’ ting freight cars in loadi: or unloading positions « the tracks, an elect: puller is said to do wor! that ordinarily requir a gang of six men a! to consume but litt current. It consis of a revolving win fastened to a hea base and winds up motor with twenty- four cylinders. This will permit a speed of 135 miles an hour, and with its enor- mous fuel - carrying capacity, the craft should be able to make _ transatlantic flights with little dif- ficulty, in the opinion cable attached to t! of expert aeronauti- | car. It can also ” _ | iidainn View of Puller on Small Truck and in Use in Railroad as ae cal engineers. Yard Setting a Freight Car used for hoisting.

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POPULAR MECHANICS )YAL PRIVATE TRAIN PIPED FOR TOBACCO SMOKERS pipe that comes in the public-utility with mains to deliver the smoke di- to the consumer, has been installed in ique private train built for the Nizam ivderabad, richest and most powerful the Indian potentates. The pipe, which hookah, or what is known in this coun- as a Turkish water pipe, is an enor- us affair installed in the engine and erated by the crew. Each car in the n is connected to the tobacco-smoke with a mouthpiece beside each ir, so that wherever the Nizam may nee to sit he will find his smoke ready. e ruler’s traveling habits are unsettled, he train is kept in readiness twenty- hours a day at his own private sta- Every eight hours a fresh engine is ched, and the crews report for duty he same time. PORTABLE COURT FOR SPEEDER SAVES TRIAL DELAYS ustice travels on wheels in a California A portable court, housed in a spe- motor car, tours streets and boule- rds so that the judge can rule on a traf- case a few moments after an arrest has een made. This relieves congestion of egular city dockets and helps offenders well as saves the ne required for ap- rearing and waiting later hearings. Prompt Hearing of Traffic Cases Is Afforded in This Traveling Court, Con- vened at Roadside; Plan Works Successfully in California Weighing In Sloop at Belmont Harbor, Chicago, before a Race; Scale Itself Weighs Nearly a Ton SCALES FOR WEIGHING BOATS HELP DECIDE RACES Determining the winner in a boat race is often a complicated problem, for many factors, including length of the ship's water line, its sail area, draft and . san consid displacement must be ered. Sloops are weighed in on a big scale suspended from The weighs about a ton, is seven ’ a crane. balance itselt feet high and registers between 8,500 and 11,000 pounds on a graduated dial. The racing rules require that the boats should be fully equipped for running when attached to scale In the panying photogray > Class R sailing vach being checked pr torv to entering to be run under th pices of the Chi Yacht club.

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Sata is more effective than strength if one only knows how to use it in dealing with bullies, ruffans or holdup men. A frail five-foot man can, figuratively, make a whipped dog out of a seven-foot rogue if he knows how to use his brain to make up for his inferior- ity in physical power. There is even a way to prevent being held up at the point of a gun which is about ninety per cent effective, if one only knows the trick. That is the simple ex- pedient of keeping one or both hands in one’s pockets while passing through loca- tions where a holdup might be attempted. No bandit, except one bereft of his sense, or with a reckless disregard for retaining a whole hide, would ever try to hold up a man whose right hand reposes languidly in his coat pocket. The bandit has no knowledge that the hand in the pocket may not repose upon the butt of a pistol. The wise stick-up man therefore chooses for his victim one who can be told to “reach for the sky” without the possibility of bringing a trigger finger unexpectedly into action. 738 NA rte oe ow to No blanket rules c be set down to offer com- plete defense against the attacks of strong-arm bandits and bullies, but a generalization of met! ods of defense can be made which will serve almost every purpose First: of all, it should be remembered that all rules of fair play have no part in dealing with an adve: sary who is obviousl) outside the pale of lay and order, and publi decency. The proble: of the person on the de fensive is that of getting the best of the attacker by brain work and doing it in the quickest and most effective way. The element of surprise movement i just as important to an individual seekin; to defend himself as it has always bee with armies. Catching the enemy un awares, and upon a quarter where he never anticipated an attack, is always on: of the surest ways of getting the best oi him. Thus, the big bully who launches a assault upon a person of lesser physique 1; usually taken completely off his guard when the little fellow hauls off with quick fist—and plants a blow squarely i1 the pit of his opponent’s abdomen. Whe: this happens, the fellow who received the blow usually folds up like a jackknife, an: spends the next two or three minute: gasping for breath, or howling with pain We say that such a blow “knocks the wind out of one.” It does that figura tively but not literally. The jolt from even a fairly weak abdominal puach is absorbed by the intestines, the spleen and the lower part of the stomach. There are no bones to protect these vital organs from serious or even fatal, injury. A blow of equal force could be landed upon the chest with out the slightest injury to the recipient.

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Next among body blows for putting an tacker out of combat, the groin is about vulnerable part of the body. loreover, a bully or rogue seldom expects harmless-looking victim to make use his feet in defending himself. He is erefore taken completely off his guard, nd is knocked out cold when the intended ictim lets fly with the point of a shoe hich catches him in the groin. If the ‘rson on the defensive wears heavy shoes, he kick is so much the more effective. Umbrellas, canes, walking sticks, hat- ins and many other articles which people ommonly carry, may be used as thor- e most ughly efficient weapons for repelling the ost vicious attacker, if one knows just iw to wield them. A person who is at- cked while carrving an umbrella usually akes the mistake of attempting to use tasaclub. A clubbed umbrella is scarce- more dangerous than a big feather, but he same umbrella, if thrust face, automatically ingerous javelin. It will gouge out an e, rip the nose, or tear into the mouth 1 cheeks like a sword. An umbrella with he point dressed down by a few strokes ta file also is a terrible weapon when ised javelin-fashion. into an at- tacker’s becomes a The intended victim of an attacker, who cane or walking stick, usually clubs down upon his opponent in an ef- fort to defend himself. It would require a very heavy cane to inflict any serious injury by a downward swing of that in- strument. An arm suddenly raised will ward off the blow completely. But, let the walking stick wielder swing his im- provised weapon horizontally, Chinaman lets drive with a and even a light walking stick becomes a carries a like a broadsword, dangerous, or even deadly, weapon. With man de- fending himself is more apt to catch his a cane swung horizontally, the assailant unexpectedly. The blow is aimed upon the side of the head, and a good stiff jolt there will make a huge bully see stars. It may break an eardrum, or cave in the side of the skull at a point where it is very thin. If the blow can be landed slightly and a little behind the ear, even a light walking stick will crush the skull. Fist blows aimed below at the face are effec- tive, but as a means of self-defense are not so good, especially since the average ruffan is usually something of a pugilist, and probably of physique superior to his intended victim. The little fellow. there- fore, should endeavor to defend himself,

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} | / | 740 POPULAR MECHANICS selves from attacks making use of the teet A physically weak per- - son can easily trim a fin- ger off the hand of husky rogue, or make such a dent in his har or arm that he'll think oj « nothing but the pain. Among classes of pe: sons who frequently ha\ occasion to act in sel! defense, newspaper ri porters and photogr phers probably head the list. They are constant! called upon to intervie or photograph perso: who don’t desire to b interviewed or photo graphed. Arguments an attacks are the logic outcome. There are i: Pose Illustrating How a Quick-Thinking Citizen Used a Jagged, Broken Milk Bottle as Dagger to Rout Burglar bearing in mind that fingernails gouging at his enemy’s eyes are more apt to inflict serious injury than a small weak fist bringing up against a hard lantern jaw. Hatpins, for women who wear them in these days of small hats and bobbed hair, are, and always have been, potential weapons of self-defense. They are to the owner, when wielded in the direction of an opponent’s eyes, precisely what the cat’s claws are in turning an angry dog. Women and girls who are annoyed by “mashers” have the most effective means of curtailing such annoyance by the use of a little cool-headed wit. Instead of displaying antagonism, they have but to feign approval—and then pass the an- noyer over to the nearest policeman. In cases of personal combat, where the person on the defensive has been seized, or has clinched with the antagonist, the most effective defense available is to make quick and decisive use of one’s teeth. A study of police records of hundreds of attack cases reveals the fact that only one person in fifty ever seems to remember to bite the assailant when there is no other available method of worsting him. Yet many instances also are recorded of per- sons who have completely defended them- numerable opportunitic for such squabbles, but they are always avoid by using a few of the repelling method known to every newspaper man. Some o these methods are worth reciting her because they can be adopted or modifi to meet the requirements of most person in moments of urgent self-defense. The newspaper photographer’s eve handy weapon of defense is the very can era that so often gets him into trouble Few would expect a press photographe to use his camera either as a shield o1 as a weapon. Thus such use of it has th: tremendous advantage of surprise. A fil teen-pound caniera when suddenly lifte to shield one’s face from a fist blow offe: splendid protection, as well as shock-ab sorbing qualities that will probably cause more damage to the fist than to the cam era. Likewise, the same camera, whet swung by the handle, becomes a weapo! that will crack a head—or better still, send the opposing party scurrying beyon harm’s way. The reporter’s favorite weap on is a leadpencil held like a dagg« against the ball of the thumb and thrust in the direction of the antagonist’s fac« No sane person will risk an eye against such an implement. Hence the threat i: most cases ends the encounter before ac tive warfare begins.

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POPULAR MECHANICS Umbrella Rammed against Attacker’s Ab- domen Is Effective and Light Walking Stick Inflicts Painful Injuries Even Your Belt Buckle May Serve in an Emergency; Buckle Swung Hard and Hor- izontally against an Assailant’s Head Easily May Fell Him Another Form of Umbrella At- tack; Using It like a Javelin Few Attackers Can Withstand the Daggerlike Thrust of an Umbrella Point in the Face; Right, Swinging Light Cane against Assailant’s Knee Cap to Cripple Him

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742 POPULAR MECHANICS In the development of improvised weap- ons of self-defense there are absolutely endless possibilities, depending, of course, largely upon the resourcefulness and initi- ative of the individual. Pins, belts with metal buckles, a shoe jerked off the foot and clubbed by the toe end, sticks, stones, tin cans, table glassware and crockery that can be conveniently broken to make a jagged edge, and many other things, are recorded among articles that have been pressed into service by persons desperately in neéd of means of defense. Wit and self- reliance are, indeed, the most powerful mediums for self-protection when it must be individually furnished. Many suggestions are contained in police records of persons who have avoid- ed indignities by means of quick thought. A few of these are listed for the valuable knowledge they may offer to others. A physician, who makes numerous calls at all hours of day and night, carries an ounce of red pepper done up in oiled paper, sewed into cheesecloth, and tied on the end of a buckskin thong. An odd, almost humorous incident of self. defense was that of a little fellow who was set upon by a big bully as a result of Punches to Abdomen Are Barred in the Prize Ring but Entirely Permissible and Ef- fective against Thugs; at Right, Using a Small Piece of Hand Luggage as Shield to Ward Off Blow; a Camera or Suitcase Will Answer This Purpose their respective automobiles having lock: fenders. The bully attempted to admi: ister a chastisement upon the driver the other car, but got a reception entir: unexpected. The little fellow grabbed small hand fire extinguisher off the da of his machine, and squirted his attacke: in the face with the highly volatile flui A policeman who arrived on the scene t investigate the traffic jam found the bul! ing motorist rubbing his eyes, gasping for breath, and rid of all thought of pe: sonal combat. We would hardly think of a strand o| wire as an instrument for overpowering bandit and delivering him into the hand of the police, but at least one incident o the sort has been recorded. coming home one night when he. wa tackled by a footpad. A sharp scuffle fo! lowed during which the intended victim o' the attack became involved with a wir Quick to think and act, he got the wir off his own feet and succeeded in takin a turn around the bandit’s neck with t! tin strand of metal. After that, stran; ling the attacker into submission and lead ing him to the nearest police call box wa the work of a few minutes. A man wa

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POPULAR MECHANICS MPING LAKE DRY TO FIND GOLD rged by reports that e quantities of gold it the bottom of a lake Devil’s canyon, near esnel, B. C., an Amer- n syndicate is prepar- to drain the basin. page water is to be di- rted by dams and imes and most of the iin body will be carried iy by a huge siphon. hen all that can be re- ved in this way has en sucked out, holes | be bored through e bottom of the lake in hope of striking one more tunnels which re driven through the les by previous miners. o attempts have been ide before to empty the ke, which is 100 feet p at the center, by eans of tunnels. A ve-in halted the first effort and, in the second, ne man was suffocated Utilizing an Old Stump for a Tourist-Registry Office; There Is Ample Space for Book and Other Records BIG STUMP SERVES AS BOOTH TO REGISTER TOURISTS foul air. More than 2,000,000 in gold is reported to have been ken from the bedrock above the lake hore, and Chinamen are said to have One of the features of the Denny Creek cooped out precious metal from the bot- tom by the simple process of using hovels attached to long handles. CARVED MODEL LOCOMOTIVE HAS MOVING PARTS Whittled out of wood with an rdinary pocketknife, a small odel locomotive has air rakes of metal that operate fter the manner of the real equipment as well as a umber of other moving parts. It took the lan who carved it % tourist camp in Washington, is the registration booth for tourists. It is in a huge cedar stump which has been equipped as an outdoor office with a shelf for the register book and space for other records. The camp centralizes the tourists, helping to decrease the fire hazard, while the booth aids in keeping track of the number of visitors and the places from which they come. Only about one early a year to omplete the intri- ite work. Whittled from Wocd with Pocketknife, This Model Engine Has Metal Air Brakes That Work oyster shell in a thousand contains a pearl, it is said.

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POPULAR MECHANICS Filling Mask and Wear- ing It; Principle Is Same as Hot-Water Bottle, but This Holder Fits. Snugly and Will Not Slip Off Even if Person Stands DOUBLE-WALLED RUBBER MASK HELPS RELIEVE PAIN Fitting snugly about the face, a rubber mask that can be filled with water, is in- tended to overcome neuralgic pains and to be of aid in skin treatments. The ar- ticle holds a pint and weighs but twelve ounces when empty. The water does not bulge at any point as it is evenly distrib- uted, and either hot or cold may be used. ROUTE USED BY PRIMITIVE MAN SOUGHT IN ARCTIC Seeking historical information rather than riches, an expedition headed by Dr. Ales Hrdlicka, of the Smith- sonian institution, has been exploring the rug- ged, gold- bearing re- gions of Alaska for trace of the routes used by primitive men in their supposed immigra- tion from Asia. Did the small islands in the 3ering strait serve as stepping stones to this continent? Where did they first establish a settlement after their crossing? What course did they take in working their way south ward? Answers to these and many othe questions were sought in the journe which included a trip down the Yuko: from Tanana, the route of the gold seel ers of 98. One of the most interestin finds was the remains of an old stone i: dustry. Dr. Hrdlicka found no traces o any really ancient settlements along the Yukon, it is reported. FUEL FROM WOOD FOR AUTOS CHEAPER THAN GASOLINE Motoring in Germany, where gasoline is expensive, is expected to become more popular as the result of a Berlin profes- sor’s discovery of a process for making fuel from wood. He is said to have pre pared twenty gallons of it at a cost of but $3.50, whereas an equal amount of gaso line would have cost $11. By means of a chemical treatment, the wood is changed into an acid and then distilled into a mo tor fuel. Tests of the substance are re ported to have been successful, and car dealers and manufacturers see an increase in their trade from this discovery. BICYCLE PROPELLED BY “OARS” GIVES HELPFUL EXERCISE Handles at the sides connected toa chain gear and actuated with a rowing move ment propel a bicycle a German has in vented to afford the ride beneficial exercise. It is steered by the feet which are supported on pedal near the posi tion of han dlebars in the usual wheel. Steered with the Feet and Propelled by Arm Movements, This Bicycle, t Reverse of Usual Kind, Develops Muscle

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POPULAR MECHANICS HOW TODAY’S WEATHER GETS MAPPED FOR YOU Lithographer Transferring the Weather Lines to Be Published in the Daily Map; Top, Left, a Ground Glass Map Whose Lines Are Changed Daily with Colored Chalk, and Be- low It, a Printed Map Showing a Severe Storm Centering over Chicago and Sweeping toward the Atlantic Coast Long before noon each day the entire ntry has been told by telegraph what lay’s weather outlook was at 8:00 a.m. ire than 200 selected spots, and print- maps showing the weather for the en- country are being distributed in ishington and.other observatory cities. hind that speedy gathering and distrib- ng lies a remarkable organization and unusual degree of efficiency. At 8:00 lock in the morning in the weather reau at Washington a dozen men gather 'get out the forecast and map. They in- le eight map makers, three printers | the forecaster. At the same moment, oughout the country, the local weather ervers take their morning readings, put m into code, and file them with the egraph companies. In preparation for t event, a nation-wide circuit of tele- iph lines has been set aside a few mo- nts after 8:00 o’clock, all linked to- er in an enormous chain. Each city nsmits its report in order, and copies others, so that when the chain is com- te, not only Washington but each town the line has the complete weather re- turns for the day. The time taken is very short, because of the ingenious code used. It embraces thousands of words, yet is so simple that the forecasters in Washington can memorize its principles quickly and decode all weather reports without look- ing at the book. As the decoding pro- ceeds, each of the eight map makers enters the data that belong to his sheet. Clouds, temperature, barometer readings and other information go on separate charts, and in addition all the principal information is entered on a master map which, when completed, corresponds closely to the pub- lished weather map. With all the returns entered, the forecaster takes the master chart and draws in the isobars and iso therms, the former lines connecting points of equal barometric pressure and the lat- ter connecting points which have reported equal temperature. The isobars are im portant because they mark the limits of the various high and low-pressure areas which in their movement over the country determine changes in the weather. Then, the forecaster dictates his weather predic- tions for the next twenty-four hours.

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POPULAR With Electric Heater for the Gold Leaf, This New Stamping Machine Will Take Large Objects GOLD-LETTER OUTFIT STAMPS BIG AND LITTLE OBJECTS Printing names, emblems, and other identification marks in gold on leather goods, large or small, is quickly and eas- ily done by a patented stamping outfit which combines a number of serviceable features. These include a “three-speed” electric heating unit for the gold, which is supplied in one- MECHANICS FLYERS MUST HAVE A LICENSE OR FACE ARREST Complete regulation of flying above | Angeles is undertaken by a new city o nance which governs all craft and traffic. kinds of Dirigibles are required to give the right of way to free balloon since the latter are unable to navigat: course. Pilots of all aircraft are required to take out licenses, and license numbers three feet high, must be painted on the underside of airplane wings. low 2,000 feet and 1,500 prohibited; Flying be the business district over residence district stunting and reckless fly are banned; passenger ships are requirt to be housed when not in use; night flying is forbidden without special permit, inspection twice yearly, and after all acci dents, is required. over feet SPARK PLUG WITH AIR INTAKE SUPPLIES ENGINE OXYGEN An automobile spark plug with an intake tube running down the center a valve arrangement that admits fre air to the cylinder at each suction strol has been placed on the claim that the air to the mixture market. makers addition of fre from the carburet assists vaporization of the gasoline charg retards oil pumping, equalizes: compre sion, and helps keep the plug clean. ONE-WHEEL-DRIVE MOTOR PLOW WORKS CLOSE TO TREES Front wheels on a telescoping axle a: a single corrugated driver of special desis at the rear, are features of a fifteen-hor power motor p lo hundred-foot rolls, two inches wide; two working plat- forms and a curved column, which per- mits handling a piece as large as a twenty- inch hatbox. The stamper is said to devised by a westet inventor. It worked can within si inches of trees, vege table rows or fenc according to report and the drive wh« runs on the hat even bottom of t! operate on rough as well as smooth leathers. A wide variety of type styles and designs can be furnished by the man- "facturers of the machine. The Single Rear Wheel Enables This Motor Plow to Work within Six Inches of Trees furrow, a surfa‘ favorable to efficie! traction, making the comparatively sn motor practical. The front narrowed to a width of only thirty inch axle can

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POPULAR MECHANICS BER-TIRED DOORSTOP SAVES MARRING OF FLOORS orstop designed to hold the door in sition, without marking or marring ors, works somewhat on the prin- a window catch, with an ec- ally mounted wheel faced with ber tire. When. not in use, heel, equipped with a lever in be operated with the kept clear of the is a result of its ec- ric pivot, whereas in it is pushed down to é lish a firm contact. MOTOR-CAR TRUNK FOLDS AND FITS UNDER SEAT ge enough to hold ‘ing equipment or lug- a trunk that fits on iutomobile running board can be ed away under the rear seat when not ise, as it collapses into a flat package. hen opened, it is solidly braced, keeps lust and dirt and is shaped to fit se- y upon the board, where it is held two clamp braces without the need of traps, ropes or other means for keep- from falling off. The trunk, which is always at hand, may be obtained large or small size and is claimed to nitable for any automobile. Open, This Auto Trunk Has Considerable Capacity, But Collapsed, It Fits under the Rear Seat MYSTERY SEAPLANE PASSES SEVERE TESTS IN JAPAN As in motor cars, there are changing styles in aircraft. A conspicuous ex- ample of this is a recent seaplane devel- Elevating the Tail of This New Japanese Seaplane Insures the Rudder , against Damage When Landing in the Water oped by Japanese builders. Details of its construction are being kept secret but new theories are said to have been applied in the design and operation, and the ship is reported to have successfully passed rigid official government tests under the eyes of experts. A noticeable feature is the curved rear part of the fuselage which rises to a much greater height above the water than in earlier similar types. EPSOM-SALT VALLEY MINED TO AID TIRE INDUSTRY A deposit of pure epsom salts, found a few years ago in the southern end of Death Valley, near Wingate pass, is being worked to supply the magnesium sulphate needed in manufacturing automobile tires. The epsom salts used in the tire plants make rubber casings wear longer. For a time after discovery, the deposit of pure salts remained valueless, since at that period the only customers for magnesium sul- phate were the drug store and doctor, and there wasn’t enough demand to make it worth while to pay the heavy transport cost necessary to bring it to market. @Whenever you find that you wish to know more about any article in the maga- zine, write our Bureau of Information.

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18 POPULAR a . MEASURING HEAT OF THE SUN TO AID WEATHER FORECASTS By means of a special measuring appa- ratus which he has completed after years — Dr. Abbott with Instrument for Measuring Sun’s Heat, to Aid in Forecasting Weather Conditions of experimenting, Dr. Charles G. Abbott, of the Smithsonian institutiofi, is reported to have found proof that the sun's heat varies from day to day and from year to vear although atmospheric conditions may be identical. Scientific weather forecasts for longer periods may be possible as a result of these findings, it is believed, as they open a way to apply the factor of the sun's heat to future weather changes PLAN CONGESTION RELIEF WITH ARCADES IN BUILDINGS Cities can dey elop without curtailing the skyscraper by constructing arcades, un- derground garages and sidewalks cut under buildings, a New York traffic ex- pert suggests. He points out that ade- quate provision for “horizontal transpor- tation” is as necessary as the installation of elevators to care for “vertical trans- portation,’ and that the plan of raised sidewalks, reached by ramps or stairs, will not be popular as people prefer to walk around an elevation rather than climb. Arcades, he declares, already have proved practical in several cities here and abroad. They provide space for many stores, re- lieve sidewalk congestion and are shel- MECHANICS tered from unpleasant weather. By stalling them inside the building line, part of the present sidewalk could be removed for additional lanes of street traffic. A uniform plan followed throughout the city center would be necessary to achieve the desired results. Parking spaces for aut in the skyscraper basements and the e1 tion of ten or twelve-story ramp garages would remove hundreds of cars from the streets, it is suggested, and limitation of parking to one side of one-way streets would expedite traffic fifty per cent. Rec- ommendations are made that parking prohibited between the hours of 8:00 a. and 9:00 p.m., and that freight termi: be established for trucking, so that long distance hauls during the day could be avoided. chandise would be transported from pier and railroad platforms at night, then tributed to the individual firms the ne day. The suggestion is also made t! apartments at reasonable rentals be ere ed near the business districts so that workers could live within walking distan of their shops and offices. This would ease the burden on all traffic lines. PENCIL HOLDER HAS BLADE ON END OF CLIP Pencil-holder clips that have a shat steel extension blade, which can be use for almost any purpose where a sm projection lies so that it cann tear the clothi and is ready f use as a knife simply slipping t! clip off or slidi it to the botto: ELECTRICITY KILLS PESTS Successful tests at fighting cestructi codling moths with electricity are report: from orchards and rose gardens in t! northwest. Wires are strung through t! trees and bushes, and a strong curre! passed along for as brief a time as t minutes a day, is said to be effective keeping the pests off. Under this arrangement, mer- knife is needed, have been placed o1 DS the market. The

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POPULAR MECHANICS lern Plane Carriers with Broad Landing Decks Are Supplemented by France in Her African Campaigns by Plane Transports like the One at the Right, Which Carry Large Numbers of Airships

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POPULAR MECHANICS followed immediately after the overthro the king, when wi cut their locks in me ory of Marie Antoin and others, who y shorn before being I the guillotine. The revived in 1836, when t! princess of Orleans hibited her painting Joan of Arc, showing t! famous saint, as she always pictured, wit bob. It was known ast Joan of Arc style. SI hair, resurrected ag in 1871, was then calle the Ninon style, in honor: ; ; ; of the famous sever or a ae ° teenth century beaut ot. : . oy P , Le ee -_ ees TE ye * TWIN-BELT SANDER ; 4 / SAVES LABOR i]s ” ll, Vertical and horizont : PONS j sanding belts are c i. aa f bined in one in a mot eS t . driven apparatus now the market. Because the duplex feature — has a wide range of us¢ Surveyors Building a Tower-around a Tree in a Philippine Jungle, in Order being suitable for to Get a View across Country above the Forest on furniture. cutle1 TOWERS HIGHER THAN TREES hardware, toys, etc. It saves time AID U.S. SURVEYORS labor and produces uniform straig grained finishes on flat or curved surface So that readings may be taken in spite of high trees, United States surveyors in [ the Philippines are often forced to con- struct towers higher than the jungle ob- stacles. Two independent structures of slender poles, one for the instruments and the other for the observer, so that his movements will not disturb the equip- ment, are built around the tree to afford views at great distances. PRESENT BOBBED-HAIR FAD MANY CENTURIES OLD Bobbed hair has joined the list of things that are not new, as a result of research by a French doctor who has listed three previous epidemics of feminine bobbing , . : san ‘ ¥ i “hi i ted Either since the French revolution. The first 5™4ine ery 5 AM ,

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POPULAR MECHANI( NCE STILL AIDS INVENTORS IN THEIR WORK nee still plays its role in science. ‘ig discoveries of recent years both e to pure chance. In one, chemists powder company, after working ths seeking a new quick-drying fin- various uses, had just poured some c soda into a preparation, when a down of the machinery suspended riments for several days. When the came to resume and they looked at ld solution to see if a fresh one was d, they were amazed to find the lac- they wanted waiting for them. The ent solved the problem by leaving the ture until the chemical did the rest. n automobile laboratory, a chemist ived the idea, during experiments ¢ to solve the causes of motor king, that the color of the explosion t have something to do with it. He for some colored substance soluble -oline. As it happened, the only one ible was iodine, and, while his color me was wrong, the use of the iodine ted in the working out of the theory nti-detonants, which may bring revo- nary changes in engine design. CHART OF BIRTHS AND DEATHS SHOWS POPULATION GAIN ital statistics about America are pre- dina novel flashing chart at the ses- entennial exposition An Electric Blower That Dries the Bather Is the Latest Innovation for Swimmers ELECTRIC BLOWER FOR BATHERS DRIES HAIR AND SUIT Intended especially for use at indoor pools, an electric blower directs a strong current of heated air upon the bather at the turn of a switch, thoroughly drying hair, body and even the suit. The equip- ment is driven with power from the light- ing circuit and can be moved about to any convenient place around the basin Philadelphia. Lights n and off to indicate hs, deaths and the tuations in immigra- nand emigration. The result of these fac- , according to a sum- on the map, is to the country a net n of one person for ry period of about enty seconds. and addresses manufacturers of ar- es described in this izine will be fur- -ames POPULATION CHANGE @ OnE BIRTH EVERY 12 SECONDS “Ss € @ OnE OF AT» EVERY 24 SECONDS , @ One eRANT EVERY tf UTES @ OnE EMIGRANT EVERY Si eeUTES NET GAW-l EVERY 20 SECONDS 4 _ —_ —— Wee C60 eedsseocccoecs ed free by our Bu- Information. Flashing Map That Shows Population Changes in United States; the Flick ering Lights Record a Net Gain of One Person Each Twenty Seconds

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POPULAR 6 Instructor Explaining to Young Recruit the Workings of the Parachute Attached to Dummy for Test SECRETS OF PARACHUTE JUMPS TAUGHT AT SCHOOL Before students parachute jumps, an Lakehurst, N. J. are allowed to make instructor at tl , training school familiar- izes them with important details of the 1e construction, how it is re- rigging, its leased and opened, and other vital points. hey are required to know how the para- chute is folded, how to adjust the harness and are taught the correct way to step from the plane and just when to pull the ring that the support. In first dummies are often used to be sure that the apparatus will work as intended. loosens tests, Largely due to the demand for fur, the raising of rabbits has become an impor- tant industry in Canada as well as in sther countries. and dressed The skins are sheared, dyed out of all recognition, and the meat affords an additional source of revenue. The animals are not difficult to raise and breeders are giving their atten- MECHANICS tion to the production of larger and finer varieties by judicious crossing. It has been said that about half of the fur now worn is rabbit. Successful imitations of mole, beaver, seal and chinchilla are made from the pelts after they have been treated. About forty are required to make a coat, t will produce a neckpiece one is enough for a pair of One of the most popular varieties of ra bits is the chinchilla whicl gloves. has a strong resemblance to the genuine chinchilla of South America. Be- cause of the small amount of ca Pp ital necessary to start a rabbit farm, the dustry is proving attractive to many persons. UMBRELLA FOR AUTO ALSO FITS IN DESK Collapsing into a small bundle t! may be placed in a case on the bac! of the automobile seat, slipped into office desk or tucked into a fair-s hand grip, an umbrella with a jointed handle is quickly raised or lowered and said to afford as much protection as t standard-sized article. It is suitable travelers, reducing the baggage by « unit, and school children can put it un the book strap. A tie keeps the ribs when the umbrella is closed. Umbrella in Compact Carrying Case Attached to E of Auto Seat; Tie Keeps Ribs Flat When Folded

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POPULAR MECHANICS — Madden in Diver’s Suit, Struggling with the Octopus; Many of These Creatures Have Strength Enough to Trap a Man and Keep Him Submerged Although Their Prowess Has Been Exaggerated MAN WRESTLES WITH OCTOPUS TO TEST ITS STRENGTH hen James Madden caught an octo- in the ocean near Venice, Calif., he led to test the strength and fighting ty of the creature. He obtained a suit and engaged in a wrestling ch with his prize long enough to con- ce him that he was glad he had worn tecting armor, for the octopus dis- ed considerable power in its eight icles. Specimens with arms several long have been captured. FLOATING TOP ON OIL TANKS TO PREVENT FIRES tanks with floating tops, that rise tall with the liquid level and always lude air from the surface, are being in- ed in many tank farms to end the dis- rous fires, usmally set by lightning, ch annually -€ause losses averaging re than $15,000,000. The floating deck vise practically stops evaporation, a that has been estimated as high as 000,000 yearly. The device was made ible by the invention of a floating bas- irrangement that seals the space be- en the top itself and the walls of the acting like piston rings in an auto- ile cylinder. The tanks are not per- cylinders throughout their height, so that a rigid top would either become wedged in narrow spots or allow air to en ter at others. To reach the floating deck a novel automatic ladder, folding like lazy tongs and sliding up or down on two pipes, which pass through guide sleeves in the tank deck, was devised. ee Folding Ladder, Sliding on Rods, Gives Access to Floating Deck of Fireproof Oil Tank

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POPULAR MECHANICS making the tests, which were aimed at disco ing the relation betw: weather conditions radio. The connectio: barometric pressure temperature with y less results is not defi or if it is definite, it i complex that it is yet understood, the searchers declare. 7 signals are little affected by temperature althoug! there is an increase static in the sumn Tests so far show tl the barometer makes tle difference when tra: mitter and receiver Interior of Light-Bath Treatment Room, Showing the Arrangement of Lamps and the Sand-Sprinkled Floor to Resemble Beach LIGHT-BATH TREATMENT ROOM RESEMBLES SEASHORE Practically all the benefits of a sun bath on an ocean beach may be enjoyed in a special treatment room in Berlin, Ger- A battery of powerful lamps fur- nishes the health-giving rays which phy- many. sicians declare are almost as helpful as those of nature, and the beach idea is further carried out by a hberal sprinkling of sand onthe floor. An advantage of the establishment is that the amount of light regulated to suit the each patron, can be needs of RADIO SIGNAL FADING WORST AT THREE HUNDRED MILES Radio programs are received with great- er clarity and volume 600 miles from the broadcasting station than at 300 miles and there is less fading at the longer distance. These are the conclusions of investigators for a naval research laboratory and an electrical company, who found that a: zone 200 to 500 miles from the sending station is the poorest for radio reception. A sat- isfactory explanation of the phenomenon has not been advanced. It is classified in the category of vagaries of radio waves. Widely scattered volunteers assisted in Copyright, Henry Miller at the same pressure, | when _ transmission from a high to a | pressure area, it is hb: at short and long distances, but at med distances of about 600 miles, it is hb: from an area of low pressure to one high. The phenomenon apparently lates to the distribution of storm ar over the country. Some investigat have said that, if definite connection tween radio and weather conditions cou be established, forecasts could be iss as to the probable results of reception LAMP MAKES OWN ELECTRICITY AND BURNS UNDER WATER Batteries are not needed for an elec- tric lantern intend- ed especially for vachts and motor- boats. Current is supplied from a generator of the magneto type, a spring mechanism being actuated by winding a crank at the side. The lamp has a handle and a shoulder strap, is not affected by ness or water, and is said to burn inde nitely by the simple operation of gi the crank an occasional turn.

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By EARLE W. GAGE 7: 1 demand for Thanksgiving and colony, and incidental to the religious fea- Christmas turkeys is so enormous that tures of the occasion, the governor sent necessary to ship trainloads to our forth four men with their flintlock fowl- ve cities. Vast ranches in the west are’ ing pieces to procure meat to grace the oted to rearing hundreds of thousands festive board that the settlers “might, after vis, while giant incubating machines, a more special manner, rejoice together.” most perfect brooders, and modern Ever since the turkey has been the emblem entific breeding methods are necessary of the day. When. America was discov- mother the deli- ered and explored by little turks white men, wild tur- ough the perilous r keys were found in ite of babyhood. large numbers from he first time that New England to inksgiving day Mexico. History the turkey were shows also that tut brought into inti- keys had been raised mate relation was in ‘ in a domestic 1 state . j a: - when Gov. L by the Aztecs of Bradford, of Ply- | % . Mexico at a still ear- uth colony, set lier period, and that le the first holi- a they were introduced to celebrate the into Europe by white thering of that , ms a ie explorers and were t harvest — made , Staia s F in ae eek highly prized as a the sturdy Pil- a table delicacy upon ms who had come ' — y important occasions. er in the “May- . ' The onward march ver” the year be- of civilization, the . h e harvest Courtesy Dept. of Agriculture aa a , Unruly Turks Are Kept from Flying over Fences by get Ta = saved the little Tying a Paddle above Wings tor car, and other wider use of the mo- 455

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756 POPULAR MECHANICS evidences of progress, all have tended to being the common thing on many ran work to the disadvantage of the turkey In the turkey-raising districts large d: which is now found only in a few sections ing plants have been built, where t! of the country. sands of birds are dressed, unifo: Because of the decreasing production of graded and packed in refrigerator cars turkeys on farms, the business of raising the trip to the consumer’s table. them on a large scale has developed into Just before the annual holiday an important and profitable industry. In Thanksgiving and Christmas a turkey the unsettled sections of the west, where is set aside. All who have turkeys to the range is unlimited, and the natural drive them to the central market, so: food is abundant, flocks of turkeys are times for twenty or thirty miles, the fi ranged much like sheep. consisting of as many as 8,000 or 10) On a tract of land in the vicinity of the fowl. Thirty men drove 8,000 tur} Mojave desert, a few miles from Los An- thirteen miles in two days. In a driv geles, a farmer turned loose several thou- this kind, a wagon is driven just in f: sand young turks raised from wild-turkey of the turkeys and a little corn is scatter: eggs brought from Virginia. .The coy- tothe leaders to keep them moving. T| otes, hawks and eagles spread the glad that become lame or tired are placed news and congregated to take a hand in’ the wagon and hauled totown. At night the enterprise. However, the turkeys fall, provision is made to stop und evinced their usual disposition to stray off grove of trees where the turkeys and dogs were sent to find them and drive __ roost. them back within bounds. In spite of the Cuero, Tex., “home of the famous tu handicaps of nature, this ranch had 1,500 key trot,” and probably the largest turkeys for market, andthe birds had dem- _ ping point for turkeys in the world, is t] onstrated their ability to thrive and mul- _ birthplace of a unique ceremony upon the tiply, when given plenty of room and lib- last day of the turkey season. Just befor erty and surroundings natural to them. the harvest festival rolls around, this « Texas is the turkey state of the Union, munity pays homage to its most famo producing one-tenth of our annual crop and profitable crop and celebrates the « of festive fowls. The Lone Star state of the season with appropriate ceremoni provides an abundance of range suitable The turkey-reigns as uncrowned king of! for the fowls, flocks of several hundred _ the festival, and a parade is held. Where Hundreds of Turkeys Are Prepared for Market, a Big Dressing Station in Texas; the Birds Are Un formly Graded and Packed in Refrigerator Cars for Long Trips

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POPULAR MECHANICS 757 es INDIAN BOYS PLAYED MARBLES $5. rWO THOUSAND YEARS AGO scovery of the skeleton of an Indian about twelve years old, with a num- of marbles, in a mound near Bain- ve, Ohio, indicates that the game was vorite among the youths of the tribe ing as 2,000 years ago. The body had n interred in a log-cabin like structure ered with a canopy, of which molded ments were found, and was clothed in irment of woven fabric. Besides the rbles, other unusual relics were found, luding stones carved to represent a irkey vulture and a lizard, beads, cere- nial specimens and other ornaments. articles evidently had been placed ;' th the body at the time of burial. BATTERY TESTER DOESN’T DRIP AND REACHES HARD PLACES Acid is prevent- ed from dripping on carpets, cloth- ing and floors by the sealed-bottom atrangement of a After Fireman Has Passed Through, the Trapdoors * battery tester now Automatically Close, Shutting Out Drafts on the market. It ED AN NG FP TRAPDOORS IN FIRE STATION SHIELD SLEEPING ROOMS flexible rubber tubing for reach- Unpleasant drafts, dirt and flies are ing difficult places, kept out of the sleeping quarters in a fire- such as batteries patrol station in Chicago by means of a in autos, without double trapdoor at the opening around the i removing them. pole down which the men slide when an- elias swering calls. Each leaf is closed, after IDEA FOR BASEBALL CURVES the ihe ae passed chremgn, by an at- GAINED FROM CLAMSHELLS tachment like those on ordinary doors. (he irregular course of a half clamshell, carelessly tossed aside, gave William IMPROVED CLAMP FOR HOSE \rthur Cummings, the originator of the REDUCES LEAKS b , curve ball, the idea of applying the prin- For automobile and airplane hose, a iple to the baseball sphere. Watching clamp has been designed that is said to be shell, he became convinced that a ball practically proof against night be made to perform similar move- leaks.. An_ essential ments if thrown in the right way. His feature is a length ‘riends laughed at his theories, but he of flexible cable demonstrated his skill while pitching for which is wrapped Harvard in 1867. Batters of the opposing one and one-half a | team were astounded at the ball’s sudden’ times around the breaks, and Cummings was heralded as hose, and exerts the “boy wonder” of baseball. even pressure. Cu

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758 POPULAR MECHANICS Walnuts Branded, the Stamper in Operation, and a Close of Cups That Hold the Nuts BRANDING PRESS FOR WALNUTS STAMPS THIRTY A SECOND In June, 1919, Popular Mechanics Mag- azine printed an announcement that the California walnut growers’ association of- fered a prize of $10,000 for a machine which would put its brand on walnuts. The award has just been made to two Los Angeles inventors and, in addition, they will receive a royalty of $10,000, payable at the rate of $1,000 a year. More than 9,000 replies to the offer were received and 100 working models submitted. The winning device, resembling im some respects a printing press, stamps the ntits to the number of 2,016 a minute, which mezns the equivalent of a whole 30,000- pound carload in one day, at a cost of but one-twentieth of a cent per pound. The nuts are fed into a lower cylin- der which has a row of little cups to hold them in place and they come in contact with an upper cyl- inder bearing small the brand on the Printers’ ink is aut matically supplied the markers from fountain above. Ne ly three years were model. An additio: sum of $5,000 was p to another inventor { an improvement in ‘ feeding mechanism. TWIN TONEARMS ON PHONOGRAPH BETTER MUSIC By introducing a ce: tain interval betwee: the tones as they are reproduced, a Germa: musician has disc ered that a more beat tiful resonance and timbre are attained Applying this theory to the phonograp! he has equipped the instrument with tv tonearms, each with its membrane a: needle, which run in the same groove a short distance apart. This distance is t: be regulated to the speed of the disk an the tempo of the music, but, in genera! a time interval of one-fifteenth to one twentieth of a second has been found sat isfactory and with radio reception, wit headphones, much less. The aim of th device is not so much to increase the ton volume as to bring out overtones and at tain greater sonority, or in the inventor words, to produce something in mus similar to the “stereoscopic effect” in ph tography. If o1 keeps the ear cli to the machine, can perceive th: lack of synchr nism in the repr: duced tones, but a distance of abot three feet, the tv tone waves ha‘ completely melt« together withou loss of the proved quality sulting from View of the Rows quired to finish the rubber stamps with Double-Armed Phonograph Which Is Said to Produce Improved Tones and More Beautiful Resonance arrangement.

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MAN-MADE CAVE ON BEACH RIVALS NATURE’S WORK — ~om - es oe wm i AIT Exterior of Cave, Showing S Skylights in Floor to Aid Illumination of Inside, and Views of Interior; Realistic | Stalactites, Mossy Growths | and Stones Collected from ‘ Distant Regions Increase the Natural Aspect of This Artificial Cavern for Picnic Parties; Electric Lights and Cooking Facilities Are Features ene Lighted Cave Room Is Large Enough for Dancing Parties

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760 POPULAR MECHANICS . AUTO ALARM HONKS WARNING are said to have fully met the claims WHEN MOTOR OVERHEATS their producers. In yard and switchi work, for instance, one unit of this ty can do the work of two steam engin: engineers declare. It is available eig! per cent of the time, as compared the forty-per-cent availability of the « kind, costs about half as much to ma tain and is operated at a fuel expense from one-third to one-sixth that of t steam type. Experts estimate that one year it will effect a saving of fr $10,000 to $12,000 on switching and yari operations over an equivalent steam e: gine. Interesting features are includ: in these efficient power houses on whee! They are independent of an outside tra: mission station for power and are re: to start on any railroad system without any change in either personnel or equi Auto-Radiator Cap with Thermostat Which Causes ment. An oil-burning engine and a di Te Horn to Blow When Motor Overheats 2 aa ; current generator, which supplies ele When the temperature of the motor trical energy to traction motors mount: reaches the danger point, a thermostat in on the trucks, are the two principal wi the auto radiator cap closes an electric of its equipment. The engine is of tl circuit and sounds the car’s horn. The six-cylinder variable-speed type, havi alarm may be stopped by turning a switch direct fuel injection. Cylinders, cylind on the dash. The signal operates inde- heads and combustion chambers are c pendently of water or steam in the radi- pletely water-jacketed. Ignition is p1 ator and is thus considered reliable in all duced by the heat of compression on! cases. It may be adjusted to heat condi- Absence of smoke, cinders and a redu tions of different cars and set to give the tion of noise are other satisfactory fe warning at any degree between 110 and tures. The oil-electric engines ha 212 degrees Fahrenheit, or higher. proved efficient in congested areas, a1 on long runs are especially serviceal OIL-ELECTRIC ENGINE POWER since they require but little water. |! HOUSE ON WHEELS teen-hundred-horsepower locomotives this type are to appear in the near futur Introduced not many years ago, oil- it is reported, and engineers are intent electric locomotives already have been in- watching the effect of this form of lo stalled on eight great railroad systems and motion on American railroading. RADIATOR RADIATOR Oil-Electric Locomotive in Cross Section; There Is a Control Station at Either End; Less Noise, Absence of Smoke and Cinders and Economy Are Features Credited to These Engines

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POPULAR MECHANICS NEW AERIAL CAMERA PIERCES SMOKE ir greater service from aerial tography is anticipated as the ilt of a faster exposure proc- leveloped by army experts at ook field to be used with ial plates manufactured for ng pictures from moving air- nes. It is expected that pho- of entire cities can be taken stances of 200 miles and from titude of 30,000 feet. Already views of mountains have n obtained at a distance of 150 spite of smoke. The cess is being kept secret for tical reasons, but includes itment of the plates with a emical which hastens the effect in exposure and makes them sitive to infrared*rays. When plates are used in connection a deep-red ray filter, the in- red rays and certain blues not cting the ordinary plate are These are the rays, it explained, that penetrate a ke haze. Light fogs have been es in rded. rced, but heavy mists, as yet, ve a barrier partly because the are affected by the amount ipor in the fog. It is expect- that further experiments will ove this trouble. To test the plates, photos’ were made of Nevada mountains a plane 150 miles away. On sierra old kind, only the immediate tory in the foreground was ealed, the rest being hidden i smoke screen. But on the new plates, ‘ distant ranges were plainly visible, al- ugh they could not be seen at the time the photographer. CLOTH WOVEN FROM BAMBOO Bamboo is being utilized for textiles rough a patented process developed in gland. The stalks are first shredded in ha way that the long fibers can be spun woven as readily as cotton or flax, and ess expense according to reports. Bam- © abounds in many tropical countries, that raw material is plentiful. One Nerve Center of New York City: Telenhone Headquarters Building from Which 120,000 Phones Are Operated BIG PHONE EXCHANGE REQUIRES SIX THOUSAND WORKERS Constructed in the “stepped-in” style of modern architecture, that has become in- ger cities arg creasingly emploved in o for the sake h telephone the nerve huge New York city, Manhattan, some 6,000 workers who are kept busy op- erating 120,000 telephones. of light and air, the building in center of houses The size of the structure is emphasized by the com paratively small buildings near the site, which is on the lower west side.

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By F. A. ZEUSLER Lieutenant Commander, U. S. Coast Guard ERELICTS—the ghostly objects that navigation and custom laws,’ devote the were once ships and are now_neither greatest part of their time to assisting ves afloat nor sunk—objects that drift withthe — sels in distress and to clearing the seas o! ewinds and currents over the seven seas, dangers to navigation. are one of the greatest dangers to the nav- Information as to the location of dere igator, even as great as the iceberg. The _ licts is received from various sources, prin berg is usually much larger and is more’ cipally from the captains and officers of apt to tear the bottom out of the ship that the great ocean liners and freight carrie: may run onto it, but it can usually be seen of the world. Upon sighting a derelict by an alert lookout except on dark nights these officers immediately transmit b and during foggy weather and is rarely radio the information to the coast guat found outside of rather clearly defined One of the cutters of the service, the ocean areas. “Modoc,” “Snohomish” or the “Senec The derelict, however, may be dismast- immediately starts out on a hunt for it t ed, it may be so low in the water that even tow it into port or to send it to the bot the best of lookouts would fail to see it tom by means of high explosives. until dangerously close. It gives no warn- The success of the search depends up ing of its presence, and may be floating in’ a number of factors, chiefly the accura any of the oceans from the South seas to of the original report, the time elaps: the Arctic and from the China sea to the _ since last seen and the weather condition Mediterranean. It is here today and gone Experience has evolved certain rules tomorrow. As if animated by some rest- follow, so that the hunt is by no mears less spirit, it wanders over the ocean im- haphazard operation. The commandu pelled by wind, wave and current. officer of the cutter, with the informatio: The United States government has des- given by the captain of the merchant ve ignated one of its agencies, the coast sel and his knowledge of ocean current guard, to hunt down and send to rest the estimates how far and in what directio: uneasy remains of what once were ships the derelict will drift during the time in order that other ships may live. The takes the cutter to reach its positior seagoing cutters of that service, in addi- Often, upon reaching the calculated posi tion to the duty of enforcing the maritime, tion, the derelict is not found, as a sudde 762

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| )erelicts, * = Waterlogged and Dismasted, This Lumber-Loaded Schooner, Found Wandering the Seas, Was Towed to Port by Coast Guardsmen to Remove Its Menace; at Le‘t, Preparing to Destroy a Derelict Barge torm or shift of wind may have caused to take another direction and then an tended search must be made. When this is necessary, the hunt is com- enced from the calculated position and a series of zigzag or rectangular urses, the cutter covers a large area, ntinuing, until the wreck has been und, for as much as ten days or two eeks, maintaining position at night, dur- ‘ foggy weather and on days of low visi- ity but steaming full speed during all ear weather. Often the cutter travels courses similar to the lines of a huge piderweb, increasing and decreasing the tance between lines of travel, according the clearness of the atmosphere. Men re stationed aloft in the crow’s-nest with werful telescopes. All floating objects e reported by them. Passing vessels are mmunicated with. The “thousand eves” i these merchant vessels are a great help this game of hide and seek. he derelict may be an abandoned eamer, a lumber or a fishing schooner or me other craft. Its condition varies m one waterlogged and awash to one tact in all respects, such as the mystery ips occasionally found off the Atlantic ast. One such ship was a coal schooner nit in the Gulf stream, all sails set but pping and the decks all in order. The schooner’s boat was astern. The cabin and men’s quarters were neat and in order, a clock was ticking on the mantel, the break- fast dishes were on the table, but nary a sign of the crew. Derelicts have been reported by vessels which, when found by the cutters, have had people on board. An instance of this occurred some years ago in the track of the transatlantic liners, when a derelict was reported by a passing vessel. A cut- ter was dispatched to the locality and after a search of a week found, not a dere- lict, but an American fishing schooner with eighteen men on board. The vessel had encountered a series of storms, losing her masts and most of her sails. She was six weeks overdue at her home port, strug- gling to travel 300 miles to the nearest land with only one sail and a stump of a mast as motive power, fighting storm after storm in the dead of winter. The and their schooner were taken home and great was the rejoicing of the fishermen’s families who had given them up for lost. The speed of the derelict is governed largely by the ocean currents, the wind also having some effect. Some have been known to travel at the rate of about two and one-half knots, while derelict, picked up by the cutter “Seneca,” had drifted 285 miles in four days. Derelicts men one 4005

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POPULAR 7 a ern ‘ =~ 7 2 - Preparing to Mine a Derelict; the Detonator, Top, Is Being In- serted in a 1,500-Pound Mine in the Center; Below Is the Cable and a Small Mine which have been aban- doned off our Atlantic coast generally drift along with the Gulf stream and, if not re- moved in time, gradu- ally find their way into the track of the transat- lantic liners, to- ward Europe. A recent case is that of the “Gov- ernor G. W. Parr,” which was abandoned off our northeastern and, when last had crossed the and the coast of Africa, having passed through the steamer lanes, sighted a number of times, picked up twice by cutters to be towed to port but lost again in the severe winter the Grand Banks, only to continue merrily on its or- iginal journey. ' going coast seen, ocean was off gales off According to one theory when a derelict reaches the eastern por- tion of the transatlantic lanes, it jumps off the edge of the lanes and drifts to the southward and eventually reaches the that large tract of com- paratively still water in the North Atlantic ocean, so named from the floating seaweed found there. Sargasso sea, It is supposed to lie between MECHANICS the parallels twenty and thirty-five north and meridians thirty and seventy west, an area seldom traversed by shipping. It is believed by some that once reaching t! lonely area, the derelict gradually breal to pieces from the buffeting it receiv: from the storms. Whenever the derelict hunter comes up with his quarry, he must decide whethe: it is to be towed to shore and beached o; destroyed where it is found. The value of the vessel and the cargo, the distance to shore, the state of the weather and the conditions of the hull all enter into consid eration in deciding this. The policy the coast guard is to save all propert if possible, and it rarely destroy a derelict if there is the least chance of saving it. The cor manding officer of the cut: ter makes a thorough ex amination of the situ ation, and if he finds that the tion to stand towing, he will take it to the near- est port. Vessels laden with lu ber or other valuable buoyant cargo will be towed to port, not onl because their owner should have a chance t recover the property, but another good and derelict is in condi- sull reason is that it almost impossible to de cient

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POPULAR MECHANICS 765 Masts and Spars, Torn Loose from Wrecks, Float to Sea and Become a Menace to Shipping Until Found and Destroyed = f° =a eet =e + . Derelict Steamer, Abandoned by Crew in j Storm, and Found Days Later by a Coast- Guard Cutter Which Succeeded in Towing Her to Port, Though Her Decks Were Practically Awash; Right, Coast-Guard Crew Preparing to Plant a Mine to Blow Up a Sunken Barge and Remove Another Danger to Shipping

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166 stroy a vessel loaded with lumber. When, in 1918, German submarines visited our Atlantic coast to prey upon our shipping, the submarine commanders learned what the coast guard had known years before— that any number of explosive bombs placed about the hull of a lumber vessel will seldom if ever destroy that vessel Such craft bombed by the Germans float- ed on the seas as derelicts, and were sub- equently towed to port by cutters. Near- ly ten years before the war, a cutter off the coast of New York had exploded twenty-four mines simultaneously around such a hull without any appreciable effect, yet those same mines, blown up in like manner around the Woolworth building in New York city, would have caused untold damage to that and adjoining buildings. Derelicts are encountered at all dis- tances off shére. Often the tow is a long drag presenting great difficulties. Such was the experience of a cutter off the New England coast which, after a struggle of a week, towed imto Boston harbor the largest derelict on record—the remains of the British steamer “Templemore,” afire at sea in the track of the transatlantic liners. During the entire time of the tow the “Templemore” was on fire and many times the towline snapped and had to be fastened again to the blazing wreck. That vessel had in her hold many tons of pig POPULAR MECHANICS copper which melted as a result of the in- tense heat, but which was subsequently salvaged. Not always does the rescuing vessel reach port safely with her prize. The strain of the tow and the seas will often weaken the derelict sufficiently to burst the hul! and cause it to sink. Sometimes strong gales are encountered, such as in the case of the “Governor Parr” which broke adrift and disappeared. A few years ago a cut ter on the Maine coast had the experience of having the hull of the derelict barge it was towing burst and sink. The barge was loaded with cotton wood, which, be- ing extremely porous, swelled and burst the hull, spilling the entire cargo of logs The hull went to the bottom in several hundred feet of water and it was only the quick work on the part of the cutter’s crew in severing the ten-inch hawser that saved the vessel from serious damage. Derelicts often turn bottom up, making them increasingly difficult to tow. Gen- erally a hull in such a position will show one end above the surface of the water while the other end is submerged. In this position is may be expected that it will drift along in the direction of the wind and current, high end foremost. The overtaking waves break over it, giving it an impetus that seems almost incredible. Probably it is this force that so frequently A Column of Water and Debris Leaps High in the Air as the Coast Guards Touch Off a Mine Planted in a Sunken Ship; the Work Is Attended by Constant Danger and Plenty of Thrills

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ves derelicts apparently counter to « her the wind or current. In finding a elict bottom up, the guardsmen climb on the bottom and fasten a huge iron ip with an eye in one end to the keel. this is fastened the towline. Upon iring shore, the deepest water must be ight or the downward-pointing masts strike against the sea bottom and ick traffic until the prize can be turned ht side up or the masts cut. If it is impracticable to tow the derelict to port, the cutter will destroy it with nes. The type of explosive generally ed is TNT and comes in two sizes, one a ty-two-pound mine and the other of ap- oximately 150 pounds. Several of these nes are placed in the cutter’s boat for nsportation to the derelict and planting. ley are placed about the hull of the ves- |, and when connected, the last mine is pliced to the mining cable, which the at pays out from a reel as it pulls away im the wreck. When it is a safe dis- nce away, the crew connects the ends of e cable to the firing battery in the boat, nd explodes all the mines simultaneously. it often, however, is destruction accom- shed by one explosion, but it frequently ippens that the operation must be re- peated many times. When the destruc- n is completed, the cutter takes sound- gs of the sea bottom very carefully in e vicinity to be assured that the depth { water is ample for all ships to pass over e sunken remains. The disposition of floating wreckage, uch as rafts, trees, spars, logs. of timber nd parts of ships’ hulls depends upon their iture and distance from the nearest avail- ble place to beach them. Ordinarily their estruction is accomplished by the use of wrecking mines, but, when issible, the spars or balks re dismantled and hoisted ‘oard or towed to the each. Wreckage attached the bottom is either iuled clear by a hawser set loose by a mine. [In many instances cut- rs have disposed of dere- ts by gun fire, among 1em the “Louisiana” hich broke in two off the pes of the Delaware. t POPULAR MECHANICS 767 Elaborate Table Top of Wood and Metal Odds and Ends; It Contains 3,000 Pieces THREE-THOUSAND-PIECE TABLE MADE OF WOOD AND METAL Using such odds and ends as soup bones and bits of silver and gold, an eastern craftsman has fashioned an inlaid table containing 3,000 pieces. The work re- quired about a year to complete. MODEL PLANE RUN BY MOTOR FLIES FIFTEEN MINUTES Model airplanes are being constructed more and more like the real ones. This is shown in a tiny craft of English con- struction, fitted with a one-half-horse- power motor and capable of making flights of fifteen minutes’ duration. The en gine was also made by the builders of the pygmy flying machine. Examining Model Plane Which Has One- Haif Horsepower Motor

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768 POPULAR MECHANICS were eagerly await the result, but tot o of them recorded 1 fact that, before the d patch was complet: Marconi’s sending out broke down. Mr. Had don tells the story as fol- “When the brea! came, Jack Mitchell me saged me, ‘Cut off Was ington for a minute ai "1 weil lows: finish the messag: It looked as though t first radiogram had abx forty words still to minutes, he sent me the conclusion, signe Guglielmo Marco: Within an hour, we wer: In a few relaying the president Where a Restaurant Is Built over a Woodland Stream; through Center of Room; Tables on Natural Rock Floor RUNNING BROOK IN RESTAURANT HELPS COOL INTERIOR Diners in-a California resort can enjoy a mountain atmosphere even while inside, for a brook runs through the room, cre- ating a pleasing effect a low as it tumbles over The tables are set on the flat rocks which form the natural floor. ledge. FIRST TEST OF WIRELESS AIDED BY RELAY OPERATOR Volunteer radio operators, the amateurs with small sets installed chiefly for amuse- ment, have rendered valuable aid to the many and now it is learned that, but for the timely assistance of larger stations on occasions, a relay operator, the first attempt at sending a wireless message very from a ship to shore, a quarter of a cen- tury ago, would likely have been a failure. The man who came to Marconi’s aid was Jack Mitchell, now dead, operator at Sias- consett, Mass. The story is told by Henry G. Haddon, manager of the wireless office at Wood’s Hole. The facts are recorded in the office diary. The test was made on the night of Aug. 16, 1901. Marconi was sending a message to President Mc- ‘ Kinley at Washington from the steamer “Lucani.” Papers all over the country reply to Marconi. Mea: the Rivulet Runs while, the apparatus been repaired and tl rest of Marconi’s message was comi! through. Except for differences in a f words, the two conclusions were identi: The bona-fide ending stopped with n RUBBER OVERSOLES FOR SHOES CARRIED IN POCKET For both men’s and women’s shoes, elastic rubber sole fits snugly at front a1 back small and is so that a pair may easily be car- ried in the pocket or vanity case. A feature is the grip for the heel which keeps the rubber f1 slipping off. SEARCHLIGHT ON HOTEL ROO! REDUCES AUTO THEFT Auto thefts in an eastern city have creased fifty per cent largely due to installation of a 43,000,000-candlepow: searchlight on the roof of a hotel, offici report. Its flashing announces a the and police, seeing the light, go at once | the nearest patrol box where they lea: the details of the crime from headquarte: The light is then directed on the secti where the car was stolen.

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POPULAR MECHANICS By Careful Training, Horses Can Be Taught to Overcome Their Natural Fear of Fire to a Remarkable Degree; These Police Mounts Plunged Willingly through Blazing Hoops at Exhibition Drill HORSES JUMP THROUGH FIRE AT RIDING MEET ips through flaming hoops featured performances of horses and riders at exhibition police meet at the sesqui- tennial exposition. The animals dis- ed no fear of the fire shooting from aked wrapping around the frames h were supported on low hurdles. A ngular piece between them, also ig- 1, made the effect more spectacular. PLANE PUSHED BY PROPELLERS LESS DANGEROUS IN FALL ith two motors between the wings at sides and back of the pilot and his panion, an airplane that is expected ve less hazardous in case of falling been designed. In the usual craft, power plant and the propeller in front n are forced back upon the pilot in a h, injuring or killing him. In the new e, the motors are placed to make nose- s less likely, as the propellers push the e. There is less noise to the passen- as well as less dirt and an unob- cted view ahead. The design also per- construction of a plane with a blunt metal nose intended to help prevent seri- ous damage in case of a fall. The ship is to have both land and water alighting gears, of which the former will have a brake so that the plane is expected to land or take off in twice its own length. FLUID IN WINDSHIELD WIPER HELPS CLEAN GLASS Fitted with a small bulb which contains a fluid that is said to keep rain and mist from. obscuring the view through the automobile windshield, a wip- er now onthe market eliminates the necessity of continued movement of the squeegee arm by hand, thus helping the driver and adding to safet y. Pressure on the bulb forces some of the liquid to trickle down on the glass, where it prevents rain and fog from clouding the view for sey eral hours. So little of the fluid is needed for each application that a single filling of the con- tainer will last for weeks.

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L ‘Greatest Feat of _ Mexicos By JOHN MONG the great railway-buildins terprises this world has seen fe any are more audacious of conceptio: fraught with more romance and adventu during the périod of construction than t line which will open the west coa Mexico to the commerce of the world will establish the first direct rail se: between Mexico City and the Ame Pacific coast, and will put Los Ang commercially nearer to Mexico City 4 it now is to Chicago. The west coast of Mexico comp! strip of territory approximately 1,200 : long, where the average width acros coastal plain is about 130 miles fro: beaches to the mountains. Fifteen rivers flow down from the mount through valleys which, for agricult productivity, are as rich as the famou leys of the Nile, the Tigris and the phrates. This vast region, includi: states of Sonora, Sinaloa and Nayar an area equivalent to four American « monwealths the size of Indiana, richest part of the entire Mexican r lic. Geographically, however, this storehouse of untouched Mexican sources has been so isolated iron rest of the republic as to be a part almost in name only. Bounded by United States on the north, by prac impassable mountain ranges on the and south, and by an ocean with no « mercially advantageous harbors on west, that coast of Mexico has long b« sort of “no man’s land” as a figure in commerce. In spite of its enormou sources of agricultural production erals, fisheries, forests and power sit« View of Construction Line

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Raalro ading [aps casuves E. HOAG electric development to stimulate ifacturing, the region has long lain int largely because it had no route mmerce to or from domestic or for- markets. re than two decades ago E. H. Harri- the great American railroad builder, the vision that characterized his mon- ental undertakings in the United States, erned the commercial future of the coast of Mexico. He visualized a tern line of rails, connecting with the ads of the United States on the Pa- coast, extending down into Mexico. suugh he never lived to see his dream ed, the work was well under way, and + ‘{ the line in operation before he died. ‘tale is told that upon his death bed his st in the enterprise was still so great he had a map of the route painted the ceiling in order that he might it, and direct the work. ter Mr. Harriman’s death the work ympleting the Southern Pacific of ) passed to another great American d builder, Mr. Epes Randolph. The he spent attempting to carry it to tion were fraught with obstacles ould have caused a weaker spirit to ip in despair. The engineering diffi- of building the road taxed the best that money could hire. And, as if vere not enough to defeat the plan, came the long vears of revolution exico. While Randolph was trying uild his road, one group .of revolu- aiter another were dynamiting es, burning stations, and tearing out ot rails faster than any army of men put them down. The work sta 7 One of the Thirty-One Tunnels

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POPULAR MECHANICS scene of spectacular, difficult and costly road building through which trains will soon be in op- eration. These 103 miles throug! the very backbone of the Mexi can continental divide will forn the connecting link between the rich west coast of the republic and the central-plateau regio: where most of the great cities an approximately seventy per cent of the total population of Mexic are concentrated. The region in the states of N: arit and Jalisco where constr: tion work is now being pushed to completion is what the Mexi- cans call “barranca” count: There is no exact English equ alent for this Spanish word, if we translate it to mean pit nacles, or land so rugged that the word mountainous falls short a descriptive adjective, we | at least some idea of what t country is like. We may marve at such engineering feats as the Panama canal, but down here Mexico we find a piece of w that literally staggers the in nation. It is the task of enginee: ing a railroad through more t Tunnel Entrance on Miravelles River Section of Southern Pacific : ‘ : of Mexico; Masonry Is of Permanent Construction a hundred miles of country whet it would seem almost ridicu nated. The discouragements were‘such to attempt the engineering of a trail that the entire project would undoubtedly which a herd of goats might be drive: have been abandoned but for Randolph’s Engineers tell how, day after day, | refusal to give up. ties of men went out fighting their Like Harriman, Randolph never lived through the barrancas on foot. So to see the work completed. He is saidto times they were able to move only t! have died imploring his associates to carry or four miles. Their clothing was to: on—and out of respect to him, and to — shreds in the heavy brush, and often Harriman, the road has been pushed ever = surveying many a painful mile, they w: since; halted only during the waning rev- find themselves in blind canyons w! olutionary periods of more recent years. the carrying through of a railroad see: With order and stable government estab- impossible. Even after the route lished in Mexico since 1923, construction finally located, not a spadeful of e of the line has been steadily pushed ahead. could be moved until hundreds of n Trains have been in regular service from of trails for the pack animals had } Nogales, Ariz., over 931 miles of completed completed. line through the states of Sonora, Sinaloa Obviously, railroad building thro: and Nayarit, to the city of Tepic, the capi- such country is an endless series of t tal of the latter Mexican state. Mean- nels, bridges, cuts and fills. while a gap of 103 miles through the The volcanic origin of the cou mountains between Tepic and La Que-_ further complicated the problem. ‘S: mada in the state of Jalisco has been the of the lava formations through which

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POPULAR MECHANICS 773 TROPICOpcCANC Le ZONA TEWPLAGA Donkey Trains Long Have Carried Freight between Central Plateau of Mexico and West Coast; Where the Railroad Crosses the Tropic of Cancer and Map of Ter ritory Served by the Rail- road; Link Complete but for Short Distance near Bottom here grade had to be run are so hard and flint- mile to be exact. More than $12,000,000 e that dynamite by the hundreds oftons have gone into the work thus far, and blasted before any digging could be more millions will be spent betore the ted. In other places the lava hills first Pullman car makes the trip down the n | floes are so decomposed that digging west coast of the Mexican republic. By b » them was like digging in an ash heap. January, 1927, the dream of Harriman and en such lava was encountered in deep Randolph will have been realized under . It caused endless trouble and expense the direction of the present president of t tuse the wall slid in and filled the ex- the company, H. B. Titcomb. tions. The expense of building the road, while 1 he cost of building the 103-mile con- great, is as nothing compared with the yori necting link between Tepic and La Que- wealth it will produce. The population b thi mada has been terrific; about $120,000 a of the three west coast states—about

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POPULAR MECHANICS Beginning of Dam on Yaqui River, Which Is Expected to,Add 850,000 Acres of Land to the Section of 150,000 Acres Now under Cultivation in the Valley 750,000—is only a fraction of those who — shocks administered during experimen! will eventually find profitable investment Many react remarkably to certain lig or employment there. The agricultural waves far above the scale to which growing season is twelve months of every. human retina is sensitive, he report vear, and the soil vields abundantly of Plants sleep much the same as living pe virtually every crop that can be produced — sons, the scientist asserts, but the fami in the temperate zones or the tropics. closing of leaflets does not always m¢ In addition to its agricultural wealth, slumber or insensibility but may be a re the west coast has mines of gold, silver ful attitude assumed when the bloss and graphite, now in operation, and an has had sufficient sunshine and rain. almost unlimitet) area of mineralized mimosa, for instance, awakens gradu country that has never been thoroughly between eight or nine o'clock and no prospected. The Gulf of California, and remains alert until evening and does not the coastal waters farther south, teem with fall fully asleep until toward the ear more than 160 varieties of commercially hours of morning. marketable food fish. Oyster beds ca- pable of supplying the demands of the lt ee Pe A ERASER IN SPRING REEL SAVES entire wes ern half of the nited Sta es TIME AND LOSS also give rise to a pearl-fishing industry of importance. Forests of mahogany and Attached to tropical hardwoods require only the rail stout cord, sixt: service to open them to world markets. 5 — ed inches ‘long; wh is wound o1 «“ - , spring reel, t PLANTS POSSESS “SIXTH SENSE , foci typewriter erase: SCIENTIST DECLARES Pane kept’ readily acc Certain species of plants have a mys- "Fa me B §6sible at all tim terious sense that enables them to detect and: the = sten minute changes in the intensity of light rapher is spared t unnoticed by the human eye, according time of putt! to Sir Jagadis Bose, the well-known East : it back into India investigator. By means of delicate place. The cor apparatus, he declares he has been able to automaticaly rewound in the reel w determine plants’ response to various the eraser is released.

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POPULAR MECHANICS 775 7 WAR GASES TESTED IN SOAP BUBBLES p bubbles are blown erious purposes at sureau of standards investigators are ing the action of us poison gases used irfare. The bubble iiner has been found satisfactory than jackets, for its trans- ney permits taking tographs which show the flame spreads ng explosions, pres- and some of the re- ms of the gas. In her department of — bureau, where fire- , | tests are conduct- he interior of a one ry building is de- = roved almost daily in riments with vari- protective materials. . of the articles ex- : ned recently was an tos theater curtain h an air space be- rhe en two lavers of the = terial. It was said to A Novelty in Outdoor Advertising; Plaster Models of Cars at Running Speed, shown no unusual to Suggest the Benefit of a Special Gasoline ; ; ree of heat on the far side even after PLASTER RACING-CAR MODELS ss ther side had long been exposed to fire. HELP ADVERTISE GAS JACK HELPS LAY WOOD FLOORS ee age pegs are vo by realistic models Of a racing car se on ES WITHOUT BRUISING BOARDS pedestals at vantage points along the “GE ma Sa EE While building highways. The plaster replicas represent ns ' | a mountain cabin, an auto in rapid passage down the track, ? a western woman the idea of speed suggested thereby being ¥ | encountered diffi- linked to the name of a special kind of ‘ | culty in laying the automobile fuel. ‘ flooring without eens here JEWELRY MADE OF RUBBER bs of the boards. She 7 — ™| experimented with Jewelry of a rubber composition, de 5 i. Sea several methods signed especially for wear at the beaches, i then adapted the principle of an old- has become popular on the boulevards ot carpet stretcher to a jack to force Paris. Bracelets of many colors, imita flooring together. It crowds the tion pearls and anklets as well as button A rds into place by the operation of a hole bouquets of the material are in high and is easy to handle and set up. favor. Large ear rings were also conspic- device is now on the market. uous features there last summer.

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POPULAR MECHANICS

formation committee Following the escape of a prisoner from a count) jail in New Jersey, loca officials authorized the installation of twelve 5\) watt floodlighting jectors about the bi ing. They were so liant and the illumi: tion so well distributed that a spool of thr could be seen at a « siderable distances dropped from any | of the building. sheriff considered 1 lights equivalent to efficient increase in ranks of the watchn as the glow made it most impossible for a: one to escape from jail without immedi detection. Floodlig't banks have been used | some time with equ good results, it is ported. One advant i ‘ 4 sare u Striking Window Display Made by Attaching Front of Auto to Glass with is th r the] "a 3 “gh Sealing Wax and Painting Streaks to Represent Cracks ally isolated from ' ' } 1 1

bank so that persons CLEVER IMITATION AUTO CRASH Ue tent on robbing have difficulty in cutt PROVES EFFECTIVE DISPLAY them off. Furthermore, the radiance s! ing in from the outside lights up the int Paint, sealing wax and an automobile _ rior so that it is clearly visible to wat cut in two and fixed to the pane of a large men or the police outside. show window, were skillfully used to ad- vertise a new car model. The result gave the impression that the auto had plunged CAPPER FOR GLASS BOTTLES ; — PROTECTS THE HAND through the glass and stopped halfway, leaving the front exposed. Cracks in the Caps are qu pane were represented by paint, the wax _-~) ly and fir sealed the bisected car to the window and < placed on bott the illusion was heightened by bits of by hand with glass and a barrier on the sidewalk. aid of ham: ———— and special sta FLOODLIGHT BANKS AND JAILS : | rg & i Seal FOR BETTER PROTECTION | tainer and pi Electricity is being further adapted to ee the cap in pla the uses of man as a protector of valuables - Should the glass b: and as a means of greater security from x» during the operat criminals. Floodlights on jails and banks the hand is protected b are affording this aid, according to reports shield of metal at the botto from the Pennsylvania public-service in- the capper.

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POPULAR MECHANICS 77 RADIO EYE ENABLES YOU TO SEE STARS IN STUDIO L. Baird, Television Inventor, at the Transmitting et, with Two Doll Heads, and, Lower Right, the Re- ving Screen; at the Right Is a Diagram Showing »w the Revolving Lenses Each Sweep across a Nar- w Path of the Picture or Scene to Be Transmitted; Note the Arrangement of the Two Sets of Lenses FF IR TOES ak Mle So EM Fas 2 ‘ m > unable to detect the intervals be- tween the spots of light, and sees the whole thing as a living picture. Pelevision—the ability to ck up on your radio re- eiver not only the sounds roadcast from the studio, aes ~ ut likewise to see the per- . - The effect is the same ormers as they sing and play as in the movies, where is now possible with a set being mar- a succession of pictures pass so keted in England. The inventor, J. L. rapidly as to give the illusion of Baird, has established the world’s first life and motion. By combining an ordi- television studio in London, with a range’ nary broadcasting outfit of microphone f fifty miles, and within that area is sell- and transmitter, with the television appa- ng radio sets that both see and hear. His ratus, and employing the regular radio stem is very much like that employed _ receiver in the home, along with the tele- n this country by C. Francis Jenkins, visor, which has a small screen on which Washington, D. C., inventor who demon- _ the pictures are seen, Baird furnishes both trated radio movies and television in his music or speech and actual sight of the boratory eighteen months ago. Baird, performers. For the present, the pictures who was experimenting with telephoned appear in black and white, like ordinary vision before radio broadcasting was movies, but as soon as funds are available thought of, reached his goal at about the for further experiments, the inventor ame time Jenkins was producing similar hopes to solve the problem of colors. esults in this country. He uses a revolv- While Baird was installing his first re- ng disk containing sixteen lenses, stag- ceiving sets in England Jenkins was car- ered in groups of eight. Atthetransmit- rying his work in this country a step for- ting station, the subject takes his place ward by successfully broadcasting com- efore the disk and, as it revolves, each plete daily weather maps. He believes the uccessive lens transmits an image of a_ time is near when ships at sea will be mall portion of his person to a photo- equipped to receive weather maps giving electric cell. Because of the staggered far more information than can be trans- irrangement of the lenses, each one takes mitted in the code messages. By the map small sweep, but they revolve so fast method the ship officers could see the lo- that, at the receiving end, where a similar cation of every storm area and follow its ens arrangement is employed, the eye is course day by day around the world.

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POPULAR Bringing Up a Load of Rats, and Expert Catching One with Bare Hands in Paris Sewer CATCHING LIVE RATS BY HAND AIDS FIGHT ON DISEASE With a box over his shoulder aid save his bare hands, a rat catcher in and no Paris clambers into sewers and other un- pleasant places in search of the rodents. He seizes the animals alive, pushes them through the funnel-shaped opening in his box, where they are held prisoners, kills them later. campaigns against rats are being prosecuted in nearly every large center in order to prevent the spread of contagious diseases and to re- duce losses of food and other produce. In spite of all attempts to exterminate them, their numbers do not and Rigorous decrease greatly, and some estimators declare that, seem to in most localities, there are more rats than human beings. MECHANICS FAST INTERURBAN LINE TOPS FIFTY-MILE SCHEDULE The honors for the fastest regular elec- tric-railway schedule in America, whic! have been held by the Galveston-Housto: electric company for the 50.41-mile trip between the two cities, changed hands re- cently when the North Shore line at.Chi- cago established a new high-speed service to Milwaukee. Traveling the 88.24 miles in two hours flat, trains on the new sched- ule maintain an average speed, including time lost in nine stops, of 44.12 miles an hour, while their actual running speed, exclusive of stops, is 51.9 miles an hour. Both records are about four miles an hour better than the marks of the Texas com- pany. No allowance is made by the do nors of the speed trophy for cars which are forced to run part of their route on city streets, through traffic. Few electric com- panies have their own city right of way, and are consequently slowed up by other traffic. The North Shore line, using the elevated structure within Chicago and a new cut-off north of the city to miss the densely settled north-shore towns be- tween Chicago and Waukegan, has un- usual opportunities for great speed. One car line runs at a rate of 38.5 miles an hou: between Kansas City and St. Joseph, Mo., but the city tracks bring the average dow! > *7 to 31 miles. BLACK-AND-WHITE TOWING CAR FOR DAY-NIGHT SERVICE To emphasize the fact that twenty-four hour service is available, the towing and “Clown” Auto Advertising Day-and-Night Service

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POPULAR MECHANICS uble cars of an Illi- garage are painted ck on one and ite on the other. The 1 is further developed sun, moon and star orations and a num- of signs, stating what ks the shop performs | what articles may be chased. side CAR WHEELS OF PAPER ‘aper used in the man- cture of eels is known as calen- ed rye-straw board. It sent to the shops in railway-car ular sheets and over ee ead a coating of flour te. A sheets placed one on the er and the lot ted to pressure of 500 ns or more. these sheets is dozen sub- After two urs’ pressure ‘ets, which have these now 4 come a solid block, are ept for a week in a dry- ¢ room after which a number of blocks e pasted together, pressed, and dried for econd week. A third combination of ers is then made, after which there is entire month of drying. To complete e wheel, there are required a steel tire, cast-iron hub and a wrought-iron plate. per which has received the treatment escribed may be used for almost any pur- e for which metal or wood is used if too much exposed to dampness. YOUNG SEALS GIVEN HAIRCUTS TO KEEP COUNT OF HERDS Haircuts for seals is the latest fashion te from the Pribilof islands. Capt. A. A. Anderson, of the bureau of According heries, 10,000 one-year-old male seals e to be sheared this year so that the cen- is takers can more readily estimate the rease next year. The plan is adopted ecause only a certain percentage may be ed each season. When Fireworks in Airplane Exvloded Prematurely; Lone White Streak Made by Falling Star Shell; Parachute Seen at Right AIRPLANE FALLING IN FLAMES REGISTERS WEIRD PICTURE An airplane set ablaze by a premature fireworks, its fall 5.000 feet explosion of height of irom a and the parachute one of the two occupants, leap of were registered by camera film during a lucky time 1 photographer had “shoot” the and had exposure. The planned to display just opened the shutter when the accident The plane streak of light, punctuated by successive occurred. burning made a bursts of fireworks. A brilliant blue-white l white star shell was recorded as a long trail and one of the aviators was seen as a small speck just below the flaming ma chine. He appeared again lower down on the picture after his parachute had opened. Although both flyers landed sate ly, one died two days later from burns. @ Whales have been known to fight for two days after being harpooned.

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POPULAR Symbol Adopted by Los Angeles Rotary Club in Cam- paign for International Friendliness FLAGS OF THIRTY-FIVE NATIONS IN WORLD-PEACE SYMBOL emblematic of the world-wide spread of Rotary clubs, a symbol adopted by the Los Angeles organization in its campaign for international good will, bears thirty-five There is a banner for each of the flags. lands to which the club’s movement has been carried. DANGER IN STINGS OF INSECTS AND HOW TO TREAT BITES Noxious their toll of human life every year, and while those that inflict more pain, those that bite may be a greater menace, insects indirectly take sting may since they are likely to carry harmful bac- The sting is a weapon and although its poison may be “clean,” that is, free from germs, in certain species of teria. wasps and bees there are two distinct poi- contain- ing entirely differ- ent substances which mix only as they are injected and react to pro- son sacs, Auto Top with Skylights for Upward View MECHANICS duce an eftect closely akin to that of tl] toxins of bacteria. and Changes in the bloo surrounding result, temporarily throwing out of actio the defensive disturbance of tissue injure part and leaving it at the mercy of a ger: invasion. mechanism of the Scratching is a common sources of infection. The temptation to do so may be lessened by applying ammonia or bi carbonate of soda. of various The biting equipment insects is often covered wit! germs from stagnant pools, garbage an filth. Because mosquito bites are more common than wasp stings, the danger oi infection is proportionately increased Common _ toilet moistened and smeared on the bite will usually relieve the itching. soap, Glycerin is even more effective The house fly does not sting or bite, but carries germs that may lodge in scratche MOTOR SAW FITS ANY BENCH AND TAKES SMALL SPACE Weighing but fifty pounds and pying less than one and one-half occu- cubic feet of space below the table, a workbench or motor- driven circular saw, operated from a lighting socket, saves time and is exception- ally useful to the amateur. It is quickly bolted into po- sition for running, the only steps necessary being to bore three and cut a narrow slot for the saw. SKYLIGHTS IN AUTOMOBILE TOP PERMIT BETTER VIEW Windows of unbreakable been installed in the top of a closed cat English manu‘a ture, to give tou class h t ists a less obstruc ed view of the sce ery. Shades ar provided on the 1 side so that lig! and heat from t! sun may be exclud ed if desired.

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AAINTS AND STAINS BEAUTIFY ROUGH CONCRETE Notable Example of the Decorative and Structural Possibilities of Concrete; Big Dining Room of Cali- fornia Hotel Showing Or- nate Cement Rafters: View of Exterior and the Lounge with Its Elabo- rately Ornamented Con- crete Trimmings; P at- terns from Molds Are Handsomely Colored

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POPULAR MECHANICS LEVERS ON AUTO PEDALS HELP _ will be finished during 1928. It is to cost CRIPPLE DRIVE CAR approximately $7,000,000, will be 8,500 fe: long, sixty feet wide and will carry si By means of hand levers attached tothe lanes of traffic, two for pedestrians and pedals of his automobile, a cripple de- four for vehicles. Some 35,000 autos an other vehicles can be handled hourly, Ps is estimated. Another large bridge is un a der way from Tottenville, Staten island, to Perth Amboy, New Jersey. EELS ANSWER DINNER BELL While fish generally are regarded among the least intelligent of living thing studies conducted by Prof. H. M. Kyle an English naturalist, show that they dis play evidences of emotion and mentalit usually associated with higher forms life. Many species in captivity are pun tual at feeding times and appear to re member where the food will be placed Levers with Which Cripple Operates Automobile; He The Chinese have a gong to summon the Proved His Skill before a Jury of Traffic Officials golden carp to meals, but it is believed prived of the use of his legs, is able to that the sight of the keeper causes the fis! drive with little difficulty. In applying to gather rather than the bell, for the for an operator's license, he demonstrated have no aural apparatus to differentiate to traffic officials the efficiency of his between tones. [Eels likewise assemble equipment. the proper feeding time, but whether the = — respond to the sound of the signal, tl SEVEN-MILLION-DOLLAR BRIDGE sight of the attendant or the odor of tl TO SPEED CITY TRAFFIC food is not known. These creatures di play great ingenuity at crawling out Guests at a Rotary club dinner in New’ tanks. One in the London zoological gar York recently caught a vision of the huge dens, unable to climb up head first, ha bridge that is to be erected between How- turned around, thrown its tail over landhook, Staten island, and Elizabeth, N. ledge and managed to escape. Anot! J., when a model of the structure was un- showed a decided preference for a particu veiled. The gigantic link, it is expected, lar tank other than that in which it |! aa Model of the Bridge to Be Built between Staten Island and Elizabeth, N. J.; Four Traffic Lanes Will B« Devoted to Vehicles and Two to Pedestrians; Over All, the Bridge Will Be 8.500 Feet Long

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POPULAR 1 first placed and on two occasions eled to that particular place, ignoring ther tank on the way. Fishes often ibit envy especially over choice mor- of food, Prof. Kyle declares. COLOR OF DIAMONDS ALTERED BY EXPOSURE TO RADIUM Yellow diamonds, comparatively cheap | plentiful, can be changed into valu- e blue-white stones through exposure radium, a New York investigator has covered, according to reports. His have been conducted for four years | in that time, none of the altered gems reverted to its original hue, but there no way of telling definitely whether the inge will be permanent. About $8,000 rth of the substance was required to inge one diamond in four days. The entist admits that the process is yet too tly to be commercially practical and is mewhat dangerous to the workers. GUNS AND RADIO IN PEACE TIME PROTECT SHIPS IN FOGS Wireless and artillery, the “war twins,” e been adapted to a useful peace-time ity for the protection of those who go wn to the sea in ships. A steady bom- rdment off the coast of Scotland, tells successfully this has been brought out by remote radio control and igni- n of an explosive mixture of acetylene dair. The firing is part of a fog-warning tem installed on a sand bank at the entrance of the river Clyde. When the mists roll in, menacing ship- ping, impulses are sent irom a radio transmit- ting station, a mile nd a quarter from the guns. The ending set is syn- ronized with the receivers to pre- ent interference. he radio waves trike a valve on the receiver, open and release and explode a mixture | gas and air. MECHANICS Calculator Propped Up on Vacuum-Tipped Legs Window-Sill Platform for Safe and Easy Washing Out- side of Panes; Can Be Used with a Belt SCAFFOLD FOR WINDOW SILLS PREVENTS ACCIDENTS Washing the outside of windows is sim- plified and made safer with an adjustable scaffold that rests on the sill. It may be adapted to various thicknesses and con- structions of walls, is strong and rigid, and is said to be capable of carrying 1,000 pounds with safety. VACUUM FEET FOR CALCULATOR Adjustable to different heights, a two-legged stand slipped under the adding machine raises it to an angle where the operator may more easily strike the keys. There are vacuum cups on the ends of the supports so that they will not be likely to,slip and scratch pol- ished surfaces.

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POPULAR Ornament Holder in Place on Auto Cowl with Light Illuminating the Motor Meter LIGHT FOR AUTO MOTOR METER ALSO HOLDS ORNAMENT Mounted on the cowl of the car immedi- ately in front of the windshield, a lighting attachment projects a brilliant beam upon the motor meter so that it can be clearly read at night, and also supports an orna- ment if desired. Besides the bright front glow, there are red and green jewels at the side which will provide the usual courtesy lights. STRAP CLASP ON WRIST WATCH PREVENTS DROPPING Loose strap ends are eliminated and the danger of dropping the watch reduced in a wrist clasp which is easily adjusted by means ofa spring pin bar fit- ting in holes at the metal This is that it flat on the wrist and is practi- I] side of a hinge. curved so lies y concealed strap is ca when the in place. POCKET-SIZE BALLOON WEIGHS NINETY-NINE POUNDS So compact that it can be fitted into a soldier's haversack small balloon when folded up, a weighing but ninety-nine pounds fully equipped, has been intro- duced for short, thrilling rides and jumps. A hotizontal propeller is mounted above MECHANICS the carrier for the pilot and may be turned and maneuvered by pulling on ropes. | flated with gas, the bag is twenty-one feet in diameter and sent over tre and buildings while making a landing. height of 840 feet has been attained, and the balloon has remained in the air t and one-half hours, according to, repo: can be of tests made by the inventor. ELECTRIC HEATER FOR ROOMS ALSO WARMS WATER Added to the familiar type of reflecting electric heater, an devised by a Ger- man inventor for warming water. It is provided connections may attachment has been with that be joined to the house mains if desired, or the wa- ter heater may quickly be removed and the reflecter used alone. The arrangement is said to be especially suitable to heating small quantities of water for shaving and other uses. MINES SUNK FOR OIL TO SERVE AS STORAGE TANKS Digging mines into oil-bearing rock stead of drilling holes has been propos: as a more efficient method for recoveri! the liquid mineral. The plan, as describ: by an eastern engineer, is to cut tunne not into the oil itself, but into tl the latter if p shafts, rock strata above or below it, small hol would be bored into the layers containi: sible. From these the oil, pipes inserted in them and product pumped to the surface. It been suggested that shafts would serve as storage basins the oil, from which it could be collected any time desired. Under the present | ing system, it is said that only about o1 fifth of the oil flows or is pumped to 1 these undergrouw! surface, the rest being trapped in caviti of the porous rock.

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POPULAR MECHANICS ELECTRICITY KILLS GERMS IN WATER fication of water ectrocuting the in- bacteria, instead ling them with cals that leave an isant taste, has recommended by hes of the water bu- of an eastern city. method consists in ng a direct current high-frequency al- ating charges igh the settling ba- by means of special Tests have water from after being ted in this way, was from odes. n that Erie, bacteria and The common of purifying drink- vater for towns and is to treat it with rine or other chem- to kill harmful bac- The substances supplied in amounts portioned to the con- ption of water, but here contamination is ely from heavy rains icking up of sewage, extra-large quan- ties are often put into the water as a recaution. An unpleasant taste is usu- the result. This would be avoided th the electrical treatment, it is said. lized. FOLDING COAT HANGER SERVES AS CLOTHES BRUSH Bristles ona ry ipsible coat nger convert e article into a iceable brush since the ac- ory folds up t, it is especially nvenient for elers. Part of hanger affords mfortable grip. Packing the Folding Boat and Demonstrating Its Light Weight; a Canvas Covering Is Stretched over the Ribs COLLAPSIBLE CANVAS BOAT FITS IN TRUNK The framework of a patented German boat is dismantled into short lengths, which, with the canvas covering, can be stowed away in a trunk for easy carrying. Strength and light weight are also fea- tures of the craft. It seats two persons and is made of duralumin, weighing only twenty-two pounds. RED LIGHTS IN WINTER GIVE EFFECT OF WARMTH Colored lights help keep theater patrons warm in winter and cool in summer, ac- cording to reports from managers. It has been found that the use of reds and yellows in cold weather produces a feeling of warmth, while greens and blues suggest the outdoors and other cooling ideas.

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786 POPULAR MECHANICS “HEAT CABINETS” BEAUTIFY HOME AND SAVE FUEL \ Introducing a Variation of the Usual Type of Radiator; Heating Pipes Pass through Series of Copper Fi: Which Give Off Warmth; Cut-Out View of Cabinet and Typical Installations Claimed to be more efficient than cast- usual radiator, there is a chimneylike iron radiators, a “heat cabinet,” recently chamber, through which the heated invented, occupies virtually the same space _ passes, escaping into the room throug as the familiar radiator, but can, if desired, grill at the top. A damper is provide be built into the wall to save floor space. shut off the air current, and when th: It introduces a radically new idea in heat- done it is claimed that the device imm: ing. In the base-a comparatively small ately ceases to radiate heat, since the « amount of pipe passes through a series of per unit remains at a constant temp: closely spaced copper radiating fins, which ture without giving off heat, except i1 draw the heat from the pipe rapidly and air current. The device is being mark: give it up to the air. The air current en- for use with hot water, steam, vapor ters at the bottom and passes up between vacuum-heating systems, and comes in the fins. Above them, in the space which _ rious sizes, based on the equivalent lh: would be filled up with the pipes of the ing values of cast-iron radiators.

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TREE ROOTS THAT others that touch it. POPULAR MECHANICS of the room- heaters come un- nted, in order that may be decorated to -+h the room. The ces, according to the , are less than for iron radiator with eld. Because of the ingement of the grill the front, it is claimed it all the heated air is rown out inio the m, preventing soiling 1 he walls. nets [era POISON PLANTS Valnut and butternut- ree roots are poisonous plants, and even weeds se roots come in con- with them, accord- to Prof. A. B. Mas- of the Virginia experiment station. declares that there is a substance in he bark of the tree roots which injures This material is not listributed widely through the soil, he leclares, but old settlers in various parts the country have reported that good rops will not grow for several seasons in i newly cleared walnut or butternut area. Gardeners have observed that nd potatoes will tomatoes not thrive under the trees and, in Vermont, the failure of a el lence rows or in the lields are frequently rile weed to grow near butternut trees noticeable. In Indiana, the state of the leading mato Map of Railroad Traced in Flowers for Garden Ornament; Required Nearly 40,000 Plants REPLICA OF RAILWAY SYSTEM DESIGNED IN FLOWERS the Design Shopmen employed by a western rail- road devote part of their noon hour to care for a flower garden they have set out in unique fashion. It represents the en- tire route of the system, nearly 40,000 plants being used to trace the design. Tunnels, mountains and other features are depicted in the 118-foot plot. HOBBYHORSE RUN BY ROCKING GIVES CHILDREN EXERCISE lion, the harmful ects of the two ees growing in economic impor- ce to growers of vegetable, and in rious parts of the untry the death of ertain weeds and en young apple ees in the vicinity walnut and but- nut trees has often Rocking backward and forward on a hobbyhorse a_ west- ern inventor has de- vised for outdoor or indoor play, propels it at a moderate rate The rider is seated over a main bearing at the center, and as the weight is shifted, cranks actu- ate the front and rear wheels. The of speed. en observed. Riding the Hobbyhorses That Move on Child Shifts His Weight motion gives children Wheels as an added thrill.

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#<of DISASTER

A Red Cross Tent Springs Up in the Midst of Tornado Ruins, Ready to Serve Emergency Rations to Relie/ Workers and Victims of the Disaster Who Are Drawn to Its Flag HE first mighty concussion that ripped open the great naval munitions depot at Lake Denmark a few weeks ago was heard for fifty miles or more around, and left a trail of shattered windows and tipsy houses more than a score of miles across. The column of smoke and dust that was flung a thousand feet in the air above the bursting shell stores had hardly reached its height before Red were flapping in the breeze of a score of towns and villages, doctors had established emer- gency dressing stations, victims were be- ing treated, field kitchens were being stoked in preparation for dinner and relief work was under way. Cross flags All that was done without any one or- dering it, in fact, before the National Red Cross headquarters, hundreds of miles away in Washington, knew that there had been an explosion. For that is the way the disaster relief of the Red Cross works. Like the marines that “landed and have the situation well in hand,” the local Red Cross units frequently have the emer- gency in hand before the telegraph can get word to the capital that help is needed. Some 3,600 local chapters, each one, as a rule, embracing a county; something more 788 than 40,000 trained nurses enlisted for cial duty, and a mobile force of practical all the doctors and surgeons in the la: explain the Red Cross’ ability to cope wit flood, fire, tornado, explosion, earthquak: or other disaster, greater or lesser, w! it is still taking place. There may be a peaceful, wefl-behav: little river flowing through your tow: that never has gone on a rampage, | the chances are that the local Red Cr chapter has considered the possibilit: a flood some day, decided just wl homes and stores are likely ta be affect who will have to be fed and lodged ; clothed, how many will need medical tre ment, and, more important still, wl house will have to be rebuilt so that owner can get back on his feet again. For the Red Cross’ interpretation disaster relief does not end with tying the physical wounds, feeding the vict for a few days in an open-air kitchen then going home about the time the st is moving off the front page, to go b next to advertising on some inside s! of the daily paper. About that time, w! the photographers and reporters have left, the Red Cross is just settling down

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Rolling Kitchens, Manned by Army Cooks, Helping the Red Cross in a Texas Flood, and a Trained Nurse work, and when the last unit leaves, conditions will be restored, insofar as possible, to just what they were before the disaster. Take the case of the hundreds of farmers who were left in ruins when a tornado swept across southern Illinois some eighteen months ago, lev- eling several towns and a broad swath of pros- perous farm land. The Red Cross was on the scene, by train, automobile and airplane, within a few hours. From near-by warehouses, tents. cots, bedding, medical supplies and food poured into the zone. Within a few hours the homeless were under cover and fed, the injured were being treated in emergency hospitals by scores of vol unteer Red Cross doctors and nurses, and the dead were being cared for, too. But days later, when the last emergency-relief measure was over, when the towns had begun to rebuild, the real Red Cross job started. Out into the country swept motor caravans, each with from fifty to 100 men, carrying tools, supplies, and their own tents and traveling kitchen. They swept the devastated territory from one side to the other, and at each farm they stopped, cleared the fields of debris, made temporary repairs to wrecked barns and houses, and, in some cases, even helped with the plowing and furnished the ‘seeds, in order that the farmer might be sure of

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790 POPULAR MECHANICS ; cee HES npn .- - Fon San s ty <<. oe 2 aX

Above Is the Red Cross Disaster Map, Whose Col- ored Dots Show the Distribution of Storms, Fires Tornadoes, Earthquakes and Other Emergencies in Which the National Organization Has Rendered Relief; at the Left Is a Truckload of Blankets and Mattresses Being Rushed from the Red Cross Warehouse to the Relief of Sufferers from a Devas tating Tornado; Enormous Supplies of Tents, Bed- ding and Medical Stores Are Maintained at Many Strategic Points —— sa,

Red Cross Workers Were Among the First to Reach the Airship ‘“‘Shenandoah”’

3

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POPULAR = a king a crop. much work as the farmer alone could accomplish in eason.,. lhe work of the emergency-repair caravan is followed sely by other assistance, looking toward permanent rehabilitation. While the emergency workers are still in he field, a careful survey is being made to determine what ll be needed to get everyone back on his feet. The irmer who is in difficulty is given financial atvards from e relief fund to buy live tock, farm implements, eed and seed, as well as irniture, clothing and ma- terial and labor for the re- building of his house, barns nd fences. In towns and villages the ime effort is made. In- tead of the farmer's live tock, seed and implements, the sufferer may even have store or other business re- placed, if that is necessary to restore him to the self- upporting position he for- merly occupied. Widows and orphans of the disaster get special at- tention, the first receiving upport and vocational edu- cation, and the children get- ting trust funds to maintain ind educate them until they In one day, one of the caravans could do MECHANICS 791 An Emergency Field Kitchen, Top; the Poster to Be Year’s Roll Call, and a First-Aid Station Used in This

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POPULAR MECHANICS are old enough to earn their own living. Many of these trust funds cover a period of several years. It is by its first emergency work, how- ever, that the Red Cross is best known. The speed with which its supplies and workers get into action is often amazing. Frequently the disaster itself has been anticipated by days through watch of weather reports. It constant is seldom that a flood, unless due to a bursting dam, can catch the Red Cross unprepared, and even then it is only a question of a few hours until relief is on the ground. Earth- quake zones are well known, and relief plans for all of them are prepared against The same is true with the tornado and cyclone belts, which can be plotted and studied. The particular re- quirements of each type of emergency— based on the study of some 850 disasters coped with since the organization was formed in 1905—are known. For ex- ample, medical aid is the predominant need after a tornado, whereas food, tents and clothing are most needed by flood and fire victims. With the emergency. country divided into three districts, each under an assistant nation director, and with more than 300 trains volunteer disaster workers who can | mobilized anywhere on short notice, t! problem of organizing relief is simplified The local chapter is first on the jo! quickly followed by newcomers with first aid stations, canteens, food depots, tent cities and anything else needed. Less than an hour after the first qual shock in Santa Barbara, a tent flying th: Red Cross flag was in action. The injur: naturally gravitated to this refuge, and doctor who happened to be in town on holiday was hard at work. Not far away women and girls are pr paring emergency rations, ranging fro: canned beans to cocoa, for the army of vol unteer workers, hastily organized by a r serve officer, and who are now tearing at the debris to rescue the injured and r move the dead. A bricklayer, arrivin from nowhere, has already constructed field oven, and stoked it with parts sal vaged from the ruined front of a near-] store. On the oven, coffee is cooking tub lots, side by side with a tub of hot dogs. The cooks are a boy who belong Murphysboro, Illinois, as It Looked after the Tornado Last Year, When a Large Part of the Town Was Wiped Out, and, at Top of Page, as It Was Rebuilt with Red Cross Aid

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POPULAR MECHANICS the naval reserve and another boy ose worldly goods are safely buried ler the ruins of a wrecked house. A vver covered with collegiate mottoes is isv delivering the food to the relief irkers throughout the town. \ll of that happened in the first hour. parently it is a haphazard growth, but se inspection shows that someone is irecting things. The food supplies, for <ample, increase faster than consump- n. Telegrams are being sent and re- ived, covering every phase of the dis- ter. A fully manned relief train rolls in 1m Los Angeles, with a hospital unit uipped to care for more sufferers than ve yet been discovered. Tent streets egin to appear, and no matter what emer- ‘ncy arises, it is being met. hat is just one disaster, and there are pproximately 100 a year, of one kind or nother, which require Red Cross aid. hat figures out a disaster for every three nd a fraction days, or about two disasters week, in round numbers. Some of them re small, affecting only a few people, and involve thousands and cost mil- ms to meet. The cost, regardless of its thers size, comes out of the fund provided each year in the annual membership roll call, extending from Armistice day, Nov. 11, to Thanksgiving. Although its assistance has been given in more than 800 disasters since its incor- poration in January, 1905, the work of the Red Cross did not really enlist nation- wide support until the war. A couple of million boys under arms learned first-hand what the Red Cross meant, and millions at home came into intimate contact with it. Out of that wartime work present vast organization of local chap ters, some 3,600 in all, and the millions of volunteer workers who rolled bandages, prepared medical supplies, handled sages from the front and looked after the needs of the families of soldiers willingly continued their efforts restored. grew the mes- when peace was There is no other institution quite like it—prepared to give emergency relief at a moment’s notice at any point, in the United States as well as abroad. Great disasters overseas, such as the Japanese earthquake, have been met with Red Cross aid as readily as a similar tragedy at home. The Rehabilitation of Murphysboro Is Typical of the Work Done by the Red Cross to Restore Each Disaster Survivor as Nearly as Possible to the Same State He Occupied before the Emergency

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POPULAR MECHANICS ys FLOWERS CUT IN EVENING LIVE LONGER Flowers, cut the even- ing before they are to b used and kept overnight with their stems sul merged in water, will last longer than those cut in the morning, according’ to James H. Burdett, di rector of the nation garden bureau. Care should be taken that the blossoms themselves are not in the water. ting the flowers ben fits most plants and im- Cut- proves the second crop 0 Annual Annu Ss, Tort such as zinnia blossoms. instance, cosmos, flarkspur, snay dragons and marigold will produce a bountiful crop of blos more Stone Monument Erected on Site of Battle of Spokane Plains, One of the Last Big Fights between Indians and Whites SCENE OF BIG INDIAN BATTLE MARKED BY MONUMENT To commemorate the battle of Spokane plains, the last big fight between the In- dians and the west, a whites in the Pacific north- monument during the second national Indian con- gress. of the descendants of the warriors who participated in the battle attended the ceremonies. The monument was unveiled by Princess America I, great- ereat-granddaughter of an Indian chief. stone was dedicated Some TINY VERTICAL-ENGINE MODEL SHOWS INVENTOR’S SKILL What is believed to be the smallest working model of a vertical engine has been constructed by a California inven- tor. Its size is ap- parent contrasted with the man’s hand it stands on. soms by cutting. If the flowers are not removed they fade and form seeds, and this halts the blooming. The peren- nials will not stand such frequent cutting, as most produce only one or two crops, but if the first is cut back, the second is usually a better one. LAMP THAT LIGHTS IF TILTED SAVES TURNING SWITCH Inclosed in a ball-shaped shade, an elec tric lamp especially for the sick room nursery or read- ing table, is light- ed or extinguished simply by tilting it forward or backward. This movement actu- ates a small ad- justable switch within the holder and saves the trouble of pressing a wall button. It is noiseles directs the rays where they are most need ed and protects the eyes from glare. @In their natural state, diamonds ar usually of a dull-lead color.

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POPULAR MECHANICS ee mg) » Three Scenes from Railway History Emphasizing the Changes of Less Than Fifty Years; Pioneer Wood-Burn- ing Locomotive at Left, FROM CORDWOOD TO KILOWATT TALE OF RAILWAY PROGRESS lransportation’s rapid changes are il- istrated on the suburban lines of the nois Central railroad at Chicago. in fifty years ago, the engines burned rdwood and a speed of twenty miles an ur was considered remarkable. Coal ought faster schedules, but steam is largely supplanted by electricity in a ‘ley system with motor cars in place of omotives. The three great “periods” in e railroad’s history were represented in exhibit showing a pioneer engine with later coal burrier and one of the elec- ‘ trains lately put into service. Less MUSIC-ROLL EDITING SAVES NATURAL EXPRESSION One of the less familiar professions is that of edit- x music rolls for player after the original s been prepared for du- ication. The master roll generally made directly an electrical apparatus nnected to the piano hich the artist plays. he editor reads the per- rations on the roll just the musician reads the tinos oal-Fired Unit in Center and, at Right, Electric Train notes and from them decides where to put the expression lines, words and other printed matter that will appear on the du- plicate rolls. These marks are glued to the master roll in raised rubber type and duplication made by a modified printing process. Under skilled editing, copies as good as the original will result. PLAYHOUSE WITH TEN ROOMS IS FAMILY HEIRLOOM Built along true architectural lines, a playhouse has served three generations of an eastern family. It contains ten rooms and an attic and still is in good condition. Built like a Real House, This Plaything Is Still in Good Condition after Many Years of Use

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POPULAR REFLECTED SOUND WAVE RECEIVER PATH OF WAVES TO AND FROM EARTH REFLECTION OF SOUND WAVE FROM EARTH Dirigible Equipped with Altitude ‘Sounding’ Appa- ratus and Diagram of Action AIRSHIP’S ALTITUDE IN FOGS MEASURED BY ECHO Almost every aircraft is provided with a barometer or similar instrument for de- termining height, but many of these have proved unreliable beyond a certain alti- tude and many accidents in fogs and in darkness have resulted. A German inven- tor has adapted the echo method of sound- ing on steamers to the airship and the airplane with good results, it is reported. The method is essentially the same as that used on water. Sound waves travel from an emitter on one side of the ship, strike the ground and are reflected back where they are registered on a receiver at the other side of the craft. From the time interval between emission and recep- MECHANICS tion of the sound, the altitude of the ship is found by a simple calculation. Te have proved the “echophone” reliable. SOUND-SLEEP PERIOD LESS THAN FIVE MINUTES A NIGHT From 14,448 measurements of the sou ness of sleep of twelve young men subject at the Mellon Institute for Industrial Re search, it was found that they slept wit! out stirring for an average of only a litt] more than eleven minutes at a time, at in half of the observations, the avera rest period was less than five minutes i: length. These facts were determined | having the subjects sleep in special bed equipped with apparatus that recorded a: movement such as a change in the po tion of the lim s or the head. The slee; ers retired at eleven o'clock and arose seven in the morning. Factors design: to produce sound sleep, such as quiet and good ventilation, were carefully watched In only one of the observations was tl period of quiet more than three how long. The observers concluded that th: average healthy person sleeps much le soundly, that is, with much shorter inte vals without noticeable movement than i commonly supposed. Fatigue after a da of hard work interfered with sleep in at least one observation. Some subjects rest ed more during the first half of the night while others enjoyed greater benefits fro: the last half and other periods. The te: dency of the subjects was to exhibit le activity during the first hour of slumb after settling down to rest, but this stead rest began any time from ten minutes t two hours after retiring. ICELESS REFRIGERATING DISH KEEPS BUTTER FRESH Sutter at other foods ai kept from spvili: in hot weather a dish having dome-shaped to containing a W ter chamber. T! cover is of earthenware, sufficiently po ous to produce evaporation, thus reduci! the temperature inside the dish.

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INSECT MODELS ARE AS BIG AS DOGS How the Fierce West African Horse Fly Looks When Enlarged Twenty-Eight Times Itch Mite, the Tiny Insect That Causes an Un- pleasant Skin Affection on Persons School Children Examining Models in Na- tural History Museum at South Kensington, England Two-Foot Model of Sand Fly Has Nearly 2,000 Hairs Set in Natural Fashion Replica of Louse, a Typhus Carrier, 1,000 Times Larger than the Original Mosquito, the Yellow-Fever Germ Carrier, as It Looks Enlarged Twenty-Eight Times y The Sphere

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POPULAR Cigarets on One Side, Matches on the Other in a Single Handy Package for Smokers BOX OF CIGARETS AND MATCHES IN ONE PACKAGE Cigarets and fourteen matches With an ignition surface are sold in one package under an arrangement devised by an Eng- lish inventor. This saves pocket room . > . rie and insures the smoker a light. The match compartment can be refilled in case the original supply gives out. SIGNALS SENT BY WINDMILLS AS SUBSTITUTE FOR PHONE Countryfolk in Holland still use their windmills for purposes of communication as they did during the times of William of Orange and the Spanish invasion. By moving the wheels slightly and turning them to different spelled out in miles, angles, a message is code and relayed many sometimes to another mill below the horizon. Private codes are used, but there are common signals for calling a doctor or policeman, for instance, or for the miller to signal that he is waiting for grist from the farmers. MECHANICS GERMS TO AID PLANT GROWTH RAISED IN LABORATORY Investigators at the university of \\ consin have been making experiment find the best strains of germs which aid the development of peas, soybeans, falfa and other crops. has been that inoculation of seeds of these plants cause little nodul to form on the roots and that these p: tuberances For some time known from the growth-produci take nitrogen transforming it into material. Some bacteria seem to be m effective than others in nodules. producing The aim of the scientists isolate a strain that can be depended uy to achieve the desired effect abundant manner in the HINGED GUARD FOR LIGHT BULB HAS HANDLE AND HOOK Electric-lamp bulbs on extension co: are easily inserted and well protected against breakage in a safety unit that cor bines a handle and hook at the top for holding the light. One side of the guar is on hinges so that it may be opened quickly for the insertion or removal of bulb without taking off the entire shield The other side is shaded, if desired. The two lock securely together and eannot | disengaged accidentally. Lamp Bracket Open and Closed, the Insulated Han and the Hook That Is Attached to Objects

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POPULAR MECHANICS Finished Picture Is at Upper Right; the Others Are Studio Poses of the Groups, to Express the Desired Action TRICKS IN PHOTOGRAPHY SERVE ARTIST AND ILLUSTRATOR Without leaving his studio except to btain pictures of appropriate back- sunds, the camera artist is able to pro- ice a wide variety of views by the use of mposite photography. It is a form of ck work such as is employed in mak- ng the thriller scenes for the movies, but esides yielding realistic results, it saves ne and cost and enables the photog- pher to turn out a high-grade picture, nce he has the advantages of good light- ‘, accurate focusing and other favorable nditions. The process consists chiefly photographing several pictures at once obtain a single view. For instance, it desired to produce a camping scene. Groups are posed under the lights of the studio to show a boat in the water, a cook- stove in operation and other typical ac- tion These are then reduced to proper size to fit the background, pasted on and the whole photographed atter re- views. touching to conceal any marks or discrep- ancies. Some studios have large equip- ments of special settings and keep lists of men and women whom they may call up- on to pose for varicus purposes. @ The Popular Mechanics’ Bureau of In- formation offers its readers of our magazine. free service to all Names and ad- manufacturers and dealers in articles described, and any other details in dresses of our possession will be furnished promptly by addressing the bureau.

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800 Crib Lowered for Use and Folded Up against Auto-Seat Back Where It Is Out of the Way FOLDING AUTO CRIB FOR CHILD HAS POCKETS FOR TOYS Folding flat against the rear of the front seat when not in use, a fabric crib affords a comfortable place for a child up to seven years old to ride in the automobile. The cover is detachable for laundering, and there are pockets for holding milk bottles, toys and other articles for the comfort and amusement of the youngster. FOOD PRICES ON CAFE DISHES SIMPLIFY FIGURING BILL Patrons of sidewalk cafes in Paris do not have to wait for checks and are pro- tected from errors in charges, as the price of the foods is stamped on the dishes in which they are served. If, for instance, a second cup of chocolate is desired, the emptied container will be set to one side, and the new one is printed with the price of the two cups. When the customer is ready to pay, he need not depend on the POPULAR MECHANICS memory of the waiter or scan a bill of fare. since he can determine the amount of his bill by simply adding up the figures on the dishes. BUMP TESTS FOR MOTOR-CAR TIRES INSURE QUALITY Auto tires for government use are given a severe test for endurance at the bureau of standards. They are mounted in sta- tionary bearings with the tread against a revolving flat rim on which are three cleat arranged to give the tire 9,000 bumps every mile the rim turns. Each tire subjected to forty-eight continuous hour of this testing, receiving 27,000 bumps hour or 1,296,000 in all. regulated, and some of the tires are said to have proved their ability to stand up satisfactorily under the equivalent of load of one and one-half tons. Pressure can be RAIL-DEFECT DETECTOR TELLS OF HIDDEN FLAWS By means of an electric tester, devis: by a Japanese inventor, defects in ra road rails are said to be quickly and a curately located and, at the same tim: their presence recorded on a moving rol! of paper. The apparatus is connected to an ordinary inspection car and is said to be simple to adjust and operate. a, " 2 Le Rail Tester in Operation behind an Inspection Car Japanese Line; Note Attachment to Rails

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AR ‘iven Treau Sta- ist a leats POPULAR MECHANICS 801 SHAFT RECORDS DEEDS licated to the early explorers helped win the northwest for United States, a memorial _125 feet high, has been erect- ir Astoria, Oreg., one of the white settlements on the In a colorful frieze that from the top of the column e bottom, sketches depicting of pioneer days have been ed. The pictorial pattern is eet long and was formed by 1g a layer of white cement a colored one, applied to the fluted suriace of the shaft. designs were cut through the layer, exposing the colored ‘rial below. The column was OF WESTERN PIONEERS erected in memory of Capt. Robert Gray, the discoverer of the Colum- bia river, Lewis and Clark, the daring adventurers who crossed the Indian-infested plains, and John Jacob Astor, trader, who founded Astoria. A spiral stairway leads to an observation platform on top of the shaft. Astor established the settlement after a perilous trip across the country and intended that it should be a central depot between the Great Lakes and the Orient for his huge fur business. The post prospered for a time, but later was seized by the English. It was restored to U.S. in 1918. Shaft Partly Finished, Show- ing Arrangement of Pictures, and, in Center, Dedi- cation Cere- monies; Right, Another Monu- ment Dedicated at Site of an Old Indian Village nat Flee parade + seoal 4, a SOFT MUSIC CALMS ANIMALS ZOO TESTS SHOW I:xperiments with caged animals have dicated that lions are apparently fond of iano music when the upper and middle tes are struck, but they roar when the keys are played loudly. Tigers ex- a similar aversion to the shrill notes the fife. This is believed to be due to fact that the tiger’s ears are extremely itive and certain vibrations cause the al to suffer pain. These reactions tantiate reports of persons traveling he jungles being saved from wild beasts music. In some countries where oxen till used for labor, the beasts seem to work better when the driver sings, and it is also customary for the Arabs to sing to their camels on long journeys. RICHES IN RUBBISH Waste from factories using wool was generally burned, but now much of it is sold for fertilizer. Worn-out sponges are carbonized and employed in the manutfac- ture of iodine. Old bones are utilized as ivory substitute, sawdust is converted in- to fuel, and thousands of dollars are sal- vaged from the sweepings of dental and jewelry workshops. Even the chimneys and the clothing of the workers vield precious fragments of metal.

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POPULAR MECHANICS Copyright, Underwood & U: Portion of Auditorium Interior, National Academy of Sciences; Walls Are of Acoustic Tile and Mural Paintin; in Soft Colors Describe Man’s Search for Truth through the Ages

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POPULAR MECHANICS ‘ C ~~ é y Mi ler Contrast in Electric Bulbs; the Large One Gives About 2,000 Times the Light of an Ordinary Forty-Watt Lamp; the Small One Is Used for Surgical Purposes Where You Can See Your Voice and Bend a Six-Inch Bar of Iron Science Building at Nation’s Capital Is Equipped to Reveal the Hidden Wonders of the Universe By OTTO WILSON | | could only see it for myself!” lo throw one more frail How often that exclamation has come’ the gap which separates the ur lips when we have been reading of | this modern wonder worl e new, startling, perhaps epoch-mak- Academy of sciences h liscovery. Not until we can see the tically one whole floor of nstration with our own eyes or building, which was opened lle it with our hands does it really ton two years ago. ‘home to us. It our desire is not half so keen as is of the scientist himself to make us tand some of the strange truths he ealing. He moves in a land of ever- romance, watching the inner work- f the universe. It is one of his t regrets th t he cannot make the nd appreciate the won- » his vision.

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POPULAR MECHANICS fy bes Kea i i - i ; ’ oe Mh “~~ : 7 2 Reis ers ee. pv a Re aE i Special Plates and Tubes Which Illustrate Clearly Effect of X-Rays on Body As Young W Speaks into 7 mitter, Her ‘ Is Reproduce Visible Re Curves 5S! Sound Wa Another View of Big and Littie Electric- Light Bulbs, and Balloon Outfit for De- termining Weather Conditions at High Altitudes. The Sphere Is Sent Up Until Expansion of Hydrogen in It Causes It to Explode, the Recording Apparatus Falls Safely to Earth on a Parachute Support and Is Returned to the Weather Bureau, Where Experts Open It and Examine Chart. Explorations by This Means Have Been Made to a Height of Over Nineteen Miles

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POPULAR ks would feel if they were ined to him. I have given lf the pleasure of acting as uide, and opening to his gaze ision of a creation unimagi- great and unimaginably as set off against the ped little world in which he ed and thought. ’o you see this little bulb?” ve fancied myself saying to “By its help one man can in an ordinary voice and an- ten thousand miles hear him. away flere is an artificial eye, far ‘potent than our natural eye. it we can look through solid and see the bones of a liv- ] ody. this machine I can meas- nd watch in action a pressure that a breath | seem like a raging tornado he side of it. Across the hall set of which shows how much I bend an iron bar entle man’s mirrors nches thick by pressing my b down on it. this lamp were connected, uld instantly produce a blaze light, simply by pressing a button, ch would blind you just as the sun ld do. It is the largest electric-light ever made, two thousand times as erful as those we use in our homes for iry light. We use it in making pic- es that move like people in real life. Here isa piece of perfect glass. It is lve or fourteen inches through, and you would have to look sharply, if 1 did not know it was there, to see that *was anything between your eyes and pencil I hold on the other side of it. e is a grating ruled with thousands of lines to the inch—so fine that they a sunbeam into its natural is a mechanism that tells us, simply urely, what a star hundreds of tril- col TS. ; of miles away is made of.” ut our visitor from the past would not know what a star was. -To explain one of these numerous devices fully ] uld almost be necessary to begin at ‘ginning and review the whole long discoveries of our modern era. MECHANICS Where the Sun and Its Spots Are Reflected, Formed into a Spec- trum and Studied without Injuring Eyes It will be simpler to describe the more striking of these exhibits as if to a con- temporary, to one of the tens of thousands of visitors that throng to the capital cit) every summer. Even from the that this beautiful marble palace is like no other of the capi- tal’s many fine public structures. outside you will see white- Across the whole front of the building runs an inscription in strange characters They are Greek, and the inscription means, hard evident “The search for truth is in one way and in another easy. For it is that none can master it fully nor miss it adds a little to out Nature and from all fact alll But each knowledge of \\ holly. assembled there arises acertain grandeut As we go up the steps and through entrance halls we have quick evidence t this is no ordinary structure we are ing. Through a wide doorway the central hall of the building, somethi which no other place in the country, haps in the world, can sho Suspended by a long wire f1 ‘>

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806 POPULAR MECHANICS

over which the pe: lum passes is a rou white disk. Upon no clouds intervene, sun presents us with photographic likeness In the center of dome above is set mechanism worked | small motor so that sun’s image is constant reflected downward one spot, although sun itself is movi: across the sky. On

Big and Little X-Ray Tubes; the the Ordinary Kind in Medical Use ter of the dome above, a polished brass ball swings silently to and fro. It regu- lates no clockwork or other machinery, and there seems to be no reason for its motion aside from the mere swinging it- self—which is indeed the case. It is a Foucault pendulum. In 1851, < renowned French scientist, J. B. L. Fou- cault, set out to demonstrate a law of the pendulum. He suspended a finely ad- justed ball, similar to the one in front of us, and set it going. No human hand touched the ball or its wire, no air cur- rents swayed it, yet gradually, inch by inch, it changed the direction of its swing. Or, rather, it did its best to keep swing- ing always in the same drection. It was the rotation of the earth on its axis that really made the pendulum change its mo- tion. Now an attendant stops the swing- ing ball and invites us to become really acquainted with the sun. On the standard which holds the dial plate Measuring the Pressure Exerted by Light Beams; an Indicator in the Deli- cate Balance the Young Woman Is Watching Swings Away from Its Normal Position as Light Is Focused upon the Scale Copyright, Henry Miller Larger Has Fifteen Times the Output of surface of the white d are some little gray fle of dust. You want brush them off with your handkerchi But if you tried that out you would | your difficulties. For each of those fle is a direct reflection of a mighty whir! storm of solar gases which could swall a planet many times as large as the ear' You have heard often of the solar sj trum. By pressing a button and lool in an eyepiece, when the attendant moved into place a finely ruled metal g: ing, you see it before you. Brilliant, vi glowing, the rainbow bands of col stretch out before you like mighty umns of light. Nothing this wond: building has to show, I think, is quite beautiful as this spectrum when the is shining brightly. Surrounding this central hall on sides are six or eight smaller rooms, with var- ied exhibits... In one is a yright, Underwood & U:

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POPULAR MECHANICS

7 ? od cae ’ . bd <n ALORA LS LMEBGS Bh eG a te eat 1 ee

Copyright, Underwood & Underwood Exterior of National Academy of Sciences Building, Where Marvelous Exhibition of Instruments Is Housed. The Structure Is Located near Lincoln Memorial hine that shows us the pressure of ht, actually at work. At one end of a le you press a button. A motor starts obbing, and a small electric light on ne ( corner sends out a beam of light ugh a slit in the metal cylinder inclos- it. The beam strikes a tiny mirror in center of the table and is reflected onto ‘ale at the end of table. In a moment a powerful light at the +1 er end flashes up. By means of a lens is focused on the edge of a thin silver te in the center of the table, suspended a thread of quartz. Its pressure turns e plate, which twists the quartz thread, to which the mirror is attached. This also rns, and the first-mentioned beam, re- ted from the mirror, moves along the le several inches. The light pressure us made visible before our eyes is about e nty microdynes, a card tells you, or ‘ ten-billionths of an ounce. In one corner of the room stands a tall s tube, three or four inches in diam- “This,” said an attendant, “is really r greatest ‘circus’ stunt.” He switched the ordinary light and pressed a button ch lighted up the tube with a beautiful, violet glow. “Look at my teeth,” he said and grinned broadly. The two rows of teeth shone out as if covered with phosphorus—except one false tooth, which was black. He took a handful of silver coins from his pocket. They were darkly tarnished, like a silver teapot that has stood long unpolished. He pointed to a screen of colored flowers. They too glowed with phosphorescent light, and continued to do so even when the light from the tube was switched off. A ghastly blue haze hung through all the air around, but disappeared when I held a card between my eyes and the lighted tube. This, in short, was the ultraviolet light which stage magicians have learned to use to produce weird effects, and which our darkened ships employed to send each other signals quite invisible to the lurk- ing submarines of the nights of 1918. We must hurry on. But we must not pass by this long, black, boxlike tube on our right. It illustrates what may well turn out to be one of the most significant discoveries in our efforts to form a con ception of the grouping of the innumer- able star suns around us. It was the great Herschel who suggest ed, more than a century ago, that the spiral

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S05 nebule might really be vast assemblages of stars, so far off that they seemed like light clouds in our telescopes. He coined for them the term “island universes.” Sut it was a suggestion only, and the evidence, until recently, seemed to be tending against the idea. It was only a year or so ago that Dr. Edwin Hubble an- nounced from the Mt. Wilson observatory in California that he had fairly conclusive proof that these nebule really were great universes of suns. In the edge of the largest and brightest of the spirals, that in Andromeda, Dr. Hubble, with the aid of the giant 100-inch reflector at Mt. Wilson, had been able to resolve the misty light into separate indi- vidual Among them were some which varied regularly in brightness, in precisely the same manner and over the same periods as certain variable stars in our own galaxy, or universe. The faintness of the variables in the edge of the Andromeda spiral indicated that they were somewhere near a million stars. POPULAR MECHANICS light years away, far too great a dista: for them to be included in our own s tem. They must therefore belong to a other universe, that of the spiral forn tion itself. It is awe-inspiring to reme: ber that there are estimated to be so: 700,000 or 800,000 spiral nebule in ¢ skies. Each one presumably is a separate universe containing billions of suns. From the sublime to the ridiculous oniy a step. As we pass again into t] central hall we find ourselves suddenly i: the company of a group of high-scho boys and girls tatking all sorts of fooler into a mouthpiece. They are really watc! ing the sound waves of their own voic« Many things in this temple of scienc: we have not touched upon. But certain! there is enough to make us appreciat: more fully than before the profound mean ing in the inscription around the dome “To Science, Pilot of Industry, Cor queror of Disease, Multiplier of the Ha: vest, Explorer of the Universe, Reveal of Nature’s Laws Eternal Guideto Trut! SINGLE CRYSTAL OF COPPER SEVENTEEN INCHES LONG Weighing slightly more than twelve pounds, seventeen inches long and two and one-eighth inches in diameter, a single crystal of copper has been prepared at an eastern research laboratory. It was with- drawn from the furnace at the rate of but a quarter of an inch an hour to permit the atoms to arrange themselves in regu- lar manner through- out the entire piece. One of the outstand- ing properties of the single-crystal copper is that it will conduct electricity thirteen per cent more effi- ciently than the or- dinary metal, which is composed of tiny crystals in chaotic arrangement. An- other property of the single crystal is that a rod of it is easily One of the Magic Products of the Scientist’s Labora- tory, a Single Crystal of Copper bent, but when this is done, it is immed ately broken up into small crystals and be comes as hard to bend as ordinary copps FIRST ENGINE USED BY EDISON STILL IN SERVICE The original steam engine used by Fd son in 1881 to make electrical current lighting purposes still in daily serv: at a laundry Mount Carmel, | It is said to be good condition is the sole means operating the plant heavy machiner Edison drew up t! specifications foi and made the inst lation. Mount ¢ mel was the town in the world ' be electrically lig! ed. It was equipp: shortly after a s) tem had been stalled at Sunbury seco!

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POPULAR MECHANICS 809 ETTERS TO EGYPTIAN KING ARE BROUGHT TO LIGHT Dating back more than 3,000 years, a eries of letters have been found written n tablets of clay, which are as well pre- erved as if composed yesterday. They re known as the Amarna letters and two the series of letters addressed to the yptian ruler of-the time have been ac- quired by the Metropolitan Museum of rt. The letters written to Akhnaton, ho was known as the heretic king, are special interest as they are almost the nly source of our knowledge of ancient ear-east diplomacy, especially as regards e relations of Egypt with her neighbors \sia. They were written on clay tab- ets which measure onty a few inches the largest dimension. The script is he so-called cuneiform or wedge-shaped riting, each tiny wedge being made by he scribe in the soft clay with the end of i reed stylus. After the letters were writ- ten in enduring form, they ‘were baked hard and the writing was thus preserved for centuries. One of the letters has been translated and reads as follows: “To the King of Egypt thus speaks \shur-uballit, King of Assyria: May it At Upper Left, Queen Tiy, Mother of Akhnaton, King of the Egyptians, Appearing at Right; and Below, the Lettérs, Written in Cuneiform Script on Clay Tablets Courtesy American Museum of Art be well with thee, thy house, thy wives, thy charfots, and thy warriors! I have sent my messenger to thee in order to see thee and to see thy land. That which my father hath not sent have I now sent to thee. One splendid chariot, two horses and one of beautiful lapis lazuli have I sent to thee as thy gift. The mes- senger whom I have sent to thee to see let him see and then go! Thy desire and the desire of thy land let him learn and then go!” SUN SHINING THROUGH BOTTLE STARTS FOREST FIRE Empty pop bottles have been instru- mental in starting forest fires in the Cali- fornia preserves, it is reported. The glass acts as a magnifier, concentrating the sun's rays and, if the heat is sufficiently intense and dry grass is near, a small blaze is started that may rapidly develop into a serious fire. Airplane-patrol service forces have been made aware of this added haz- ard and take extra care in surveying sec- tions visited by tourists.

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POPULAR L John Merton Wearing Suit, Shoes and Hat Woven of Cornhusks, Dyed to Produce Design SUIT AND SHOES OF CORNHUSKS COST TWENTY CENTS At an expense of only twenty cents for thread, a Missouri man has made himself a suit, hat and pair of shoes from corn- husks. The material was cut in strips and woven into a sort of fabric. A design was worked in pieces dyed red and blue. The question of buttons the solved by using corncobs. for coat was LOCK HANDLE FOR MILK CANS ELIMINATES USE OF WIRE As a substitute for cumbersome wiring, or other methods of fastening, a milk-can cover, lately introduced, has a handle that securely to ‘ the edges of the locks container and will not come off un- released regular less in the This done pulling the handle. To lock the top, one of the lugs on way. is by MECHANICS the cover is placed in a slot on the c¢ and the other side is pressed down firm This arrangement protects the contents case of accident. MONKEYS CAPTURED WITH RUM BY AFRICAN NATIVES An easy way to capture monkeys h: been discovered African bushmei They place a bottle of native liquor unde: a tree where the monkeys play. The an mals, attracted by the odor, drink and be- come intoxicated, then fall asleep. The awake in Twenty-nine taken this way were recently brought to tl country by M. Bistany of the Bronx zoo. He declared that they dane: play and sometimes fight when under t! influence of the drink. by cages. George CODE CHECK FOR RESTAURANTS HELPS KEEP ACCOUNTS Most restaurant pay checks simply state the amount due from the patron, but special form, recently devised, is intended to show which dishes are the most popular and how much is be- spent for that particular ar- ticle. In addition to punching the total due to the cashier, the waiter perforates the slip the names of the various kinds of These arranged an ing food are conveniently cover practically every item likely to included in the restaurant menu. F table service, a hand punch is employe At counters, a special perforator ,with holder for a pad of checks is placed whet it 1 is accessible to several attendants. * ELECTRICITY DRIES DATES Moisture absorbed by dates after p1 ing, packit plant by placing the fruit on trays in sma rooms into which electrically heated The s3 tem is said to have been helpful last se is removed at a western is blown under slight pressure. son because late rains threatened to sp much of the crop.

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THE JAZZ-MUSIC MAKERS OF OTHER DAYS Upper Leit, Jazz Band in One Instrument; It Has Seven Sounding Horns and Two Key- boards; Right, Harmonica, Revolving Units Played with Ros- ined Fingers A Piece Popular in the Nine- teenth Century, the Triple Cith- ara, Suggesting the Double Gui- tars and Banjos of the Presen:- Day String Bands At the Left Is the Turning Lyre of the Seven- teenth Century, the Possible Forerunner of the Hurdy-Gurdy and Its Sprightly Tunes; Above, an Oddity Even among Antiques, the Nail Vio- lin Played by a Russian Musical Director

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812 POPULAR PUSH-BUTTON METAL LADLE CONTROLLED BY ONE MAN i Pouring a Ladle of Molten Metal from Suspended Car- rier Equipped with Handlebars to Simplify Operation Running on a rail attached to the ceil- ing of the foundry, a metal pouring ladle now on the market can be raised by means of a push-button control attached to the handlebars beneath the operator’s thumb so that it can be manipulated by one man.’ The carrier can be pushed by hand or moved electrically. CROSS-COUNTRY RACING AUTO HAS PROTECTED TIRES Designed for traversing rough country as well as for speed, a Belgian racing car combined several interesting features. Heavy mudguard protectors for the wheels were conspicuous and the auto’s lines were calculated to decrease wind resistance. The tires were me 4 oP MECHANICS shielded as much as possible to prevent punctures, as the course of the race la far from repair stations. SAFE SUBSTITUTE FOR IODINE IS NON-POISONOUS Potassium permanganate is being re ommended as a satisfactory substitute f iodine in treating cuts and bruises. It said not to burn or smart on applicatior keeps indefinitely in the dry state and eliminates the danger of overdoses, as is not poisonous. hali a teaspoonful in a cup of water For ordinary usage of the crystals dissolved is sufficient, but a tea spoonful is recommended for ivy poison ing. the dry crystals are In severe cases, such as snake bite pressed directly into the wound or into small incisions about it / GAME OF LETTERS AIDS YOUNG IN LEARNING TO WRITE Formation of let- ters and words is made an_interest- ing and instructive game with a set of cut-out pieces of thirteen different shapes. There are “ Pop co) c. A. Old l ninety-eight units to the outfit, from which nearly 250,000 words can be spelled. The pieces are of durable material and form letters in script, not in the usual capital styles of the ordina: blocks, so that the child becomes famili with the characters he will use in writing Designed for Heavy Going as Well as Speed; Belgian Racing Automobile with Its Guarded Tires and Stream line Body to Decrease Wind Resistance; Note the Protected Headlights and “Spot” near Driver

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POPULAR MECHANICS KLIEG LIGHT MADE HARMLESS BY SCREEN jurious effects to the caused by the short et rays from the ts used in motion- ture studios, can be ided, the bureau of ndards has suggested, placing a screen of ss in front of the arcs. is shield is to contain small percentage of a emical, cerium oxide, d is intended to ab- rb the short light rays t injure the vision. A eet of common win- class, about one- irth of an inch thick, uld prevent some of harmful rays from iching the eyes, the in- tigators declared, but specially treated een* was found more ective. Adoption of e suggestion would ne- sitate the use of white vellow -flame carbon ectrodes in the are hts and the film would ve to be prepared in h a manner as.to become sensitive to e red and yellow region of the spectrum the bureau scientists believe. SCREWDRIVER OF SEVEN EDGES FITS ON KEY RING Seven working edges, inging from one- ghth to three-fourths tan inch in width, give key-ring screwdriver ow on the mar- et more than or- inary usefulness. t is all metal and the part corresponding to the handle affords wrenchlike turning everage so that it is almost as effective a larger tool and will function in dif- cult places where the common ould not easily be used. type Fashioning Molds of Famous Lincoln Statue Directly from the Bronze in Chicago Park; Plaster Was Removed in Sections CAST OF LINCOLN MONUMENT MADE IN OUTDOOR STUDIO Because the original molds could not be found, craftsmen prepared a duplicate of the famous St. Gaudens statue of Lincoln for the sesquicentennial exposition, di- rectly from the bronze monument in Lin- coln park, Chicago. An outdoor studio was constructed of canvas and scaffolding and the plaster casts molded in sections, preparatory to making the copy of the figure. This great president standing, was unveiled in 1887 and is the better known of the two Lin- coln monuments by St. Gaudens in Chi- cago. In the other the figure is seated. It was recently erected in Grant park. statue, showing the @ Natives of Africa use 800 languages and dialects.

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Rubber Safety Handle on Elec- tric-Cord Plug, Prevents Shocks and Burns and Re- duces Breakage of ires For Lifting Ice-Cream Cans, This Handle Clamp Grips the Raised Collar and Holds Tightly as Container Is Removed - Sip, Marred Floors and Bothersome Noise Are yy Eliminated by Using , This Rubber - Insulated Chair Tip Automatic Toaster Shuts Off Cur- rent When Bread Is Browned Suffi- ciently, Saving Electricity and Scorching; Levers at Side Regulate the O>-eration Combination Clean- ir Crayon and P . : - yo poli Gas Suppl. for Cooking, in Chemical Brush Cylinders Ordde of Hi Pad for Removing ylinders sid: o ouse All Kinds of Spots

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Strainer and Im- merser .for Cook- ing Greens Fits on Saucepan Rim Electric Water Purifier of Con- venient Home Size, Operates from Lamp Socket and Is Said to Re- move Chlorine Taste and Odor While Consuming but Little Current L r Traveling Dining Room for the Birds; This Sheltered Feed House, Suspended on Cable, Is Drawn In for Filling, Then Pulled Back, Away from House Where Birds May Gather without Fear Sore Knees Are Pre- vented While Scrub- bing Floors by This Soft-Rubbber Pad Which Also Protects Clothing Electric Heating Unit for Liquids Slips ‘into Basin iin it by addressing Bureaw of Information, Popular Mechanics Magazine,

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POPULAR MECHANICS GWT RANSMITTER ~4 a RECEIVER Drawing, Showing Housewife Using Microphone Instal- lation to Call Maid, and Diagram of Circuit MICROPHONE FOR HOME USE SUBSTITUTE FOR BUZZER Essentially like the microphone used in radio transmission, a small unit for home or office and the confusion that often results from a buzzer. The op- erator speaks his orders into it just as he would into a telephone mouthpiece. Serv- ants or clerks thus learn what is wanted without having to make a trip in response to the signal. The outfit is simple to in- stall and may be connected to the buzzer wires already in use. A battery of not more than six volts should be used, in or- der to prevent burning out the carbon in the transmitter. Saves steps COSTLY CHINESE DRUG MADE BY SYNTHETIC PROCESS Solution of a medical riddle that has per- plexed investigators for more‘than forty years is reported from the university of [llinois in the discovery of a process for making ephedrin, a valued Chinese drug, synthetically. In the natural state, the product is obtained from a plant and is considered beneficial in treating nasal troubles and as a substitute for adrenalin. High costs prevented marketing it exten- sively and, during the last twenty years, many efforts had been made to the drug by chemical processes prepare GLACIER RAZES HIGH MOUNTAIN IN ALASKAN RANGE Clouds of what appeared to be smoke rising from a peak not far from Cordova Alaska, led to reports that a volcano in action. Investigation showed that there was no eruption, however, for th: supposed smoke was dust caused by slides of soft shale from a mountain 3,000 feet high being pushed over by a glacier. The ice mass had changed direction. Its ter rific pressure against the base of the spur had dislodged the upper strata. It is lieved that the lofty peak, in time, will reduced to a mere hill. 1 CORROSION PLATES FOR SHIPS PROTECT STEEL HULL To prolong the life of the steel hulls of vessels, zinc plates, bolted to the keel op- posite the propeller are said to be effective They take up the chemical action pr duced by the blades revolving in conta with the salt water, an effect -similar that which occurs in a wet-cell batte: The zinc units function as positive plat: so that the corrosion on the steel is mini mized. The strips last several years. Protecting Plates Are White Squares to Left of Figu on Hull; They Prevent Corrosion

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POPULAR MECHANICS 817 SHADOW BOX FOR PRISONERS TO END THIRD DEGREE Questioning Men behind the Shadow Screen; There Is a Numbered Space for Each, and Cross Lines Give Height Measurements; Suspects Cannot See Their Questioners \s a substitute for violent third-degree ictics, Los Angeles police have been ng a shadow box in questioning sus- ‘ts. Prisoners stand on a low stage, ith a curtain in front, and lights are so arranged that the persons on the platform cannot see anyone on the other side of the drop, but the police have a clear view it the suspects’ faeces and can study their annerisms and movements unwittingly evealed. It is thought that this arrange- ent may help in obtaining confessions om prisoners, as the men are not so kely to assume the mask of defiance or lifference which has often been found hard to break in an open interview. PRESENT TYPE OF STEEL HAT BEST HEAD PROTECTOR “Tin hats” of the type used during the war to protect the heads of American sol- diers from rifle bullets and shrapnel are not to be discarded by the army, according to a recent announcement, as they have been found more efficient than other styles. ’xperiments were made with helmets sim- ilar to those used by spearmen in medie- val days, with others like the Germans wore and still others resembling the hel- mets worn by the Crusaders. Under stren- uous tests with machine-gun and rifle fire, the present type proved superior, accord- ing to the findings of the infantry board, and recommendations were made that this kind be retained. SPECIAL AUTO-CHASSIS OILERS SIMPLIFY LUBRICATION Oiling the auto chassis with one hand and in a few minutes is said to be simple with the aid of special valve oil cups and an improved can. Motor oil is used instead of grease, the cups being fit- ted with a valve which supplies the lubri- cant as needed. The spout of the can is shaped so that the cup lid can be opened with it, flushing and filling the holder with one easy motion.

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POPULAR MECHANICS 7 FAN 7} | deat ‘Y y Five Standard Ways of Cutting a Diamond; from Left to Right, Round Brilliant, Emerald-Cut (Square Marquis, Emerald-Cut (Oblong), and the Pendeloque, Popularly Known as Pear-Shaped Diamond Digging in the Wilds Strange Stories and Tragedies of the World-Old Search NE. of the C opening of a new diamond field. For miles along the sun- parched veldt, the hordes had gathered, com- ing by automo- bile, buggy, huge Boer vans drawn by oxen, lumbering plains wagons and on foot. They met in a desolate land where hardly a blade of grass or a stunted bush could be found. There were no wells or springs for miles,and huck- sters selling water in small casks at $1 each did a land- office business. strangest races ever run was staged one last spring when thousands of men women toed the mark under a blazing south African sun waiting for the starting gun in a dash which brought to a few great fortune and to the vast majority bit- ter disappointment. for the Queen of Gems foot . day and mile-long true “diamond pipe,” up from below. Each The occasion wasthe along the starting line A mile away lay the future diamor mines, a roughly circular bed of blue cl extending down to unknown depths once the vent some long-extinct volcano through whi the boiling blue-clay mud had simmer man and won , toeing the m laid down by the wardens, carried fou small stakes mark the ners of the hoped - for claim. The rea for the sta: pede, whi drew work from other di mond _ fields, farmers from the veldt and clerks and venturers fr distant citi« was the a dental | disc: ery of $70,000 worth of di monds, lyi: on the ops ground. T governme! Diamond Sorters with a Vast Fortune in the Rough Dumped on the Table before Them; a Scene from a Diamond Mine opened the p! for mining, a!

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20AD0S BETWEEN “LAIMS FOR REMOVAL OF ROCK, POPULAR MECHANICS SEPARATE PITS OF INDIVIDUAL CLAIMS i eae Le EME ee awe SEPARATE CLAIMS FORM MANY TERRACES WITH COMMON — WINDLASS SvST Ure, > TUNNEL THROUGH CRATER RIM». BLUE GROUND OF THE “DIAMOND PIPE -ONTAINING THE PRECIOUS STONES BORNE ee Te ROM GREAT DEPTH “Titi fe EF LAV, THE

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$20 laid down the rules for claims. Eventu- ally all the separate claims probably will be sold to one of the big operators and merged in one, for bucking the world’s diamond syndicate is a losing game. The supply of diamonds on the market is strictly limited to what the world can ab- sorb, in order to keep up the prices. Diamond mining is like no other form of wealth extraction. The south African mines, richest ever found, are invariably the “pipes” through which the crystallized carbon, manufactured in the intense heat of the center of the earth and compressed under the vast weight of the surface land, was forced upward along with boiling blue mud, to cool and remain for untold cen- turies until accidental discovery by man. The diamonds found in this country, in the Ozarks of Missouri and Arkansas, are of entirely different origin, appearing usu- ally in mountain-stream beds. Where they came from no one knows. Once a pipe is found and the first claims staked out, the POPULAR MECHANICS far enough, another pit is sunk, and a sec ond terrace started, followed later by if the pit third, and even more. Electric railways replace the crude ae: skips, and tunnels are driven through th rim rock to form an easy grade to th drying fields and the washing plant. Giant searchlights, spotted about the rim, light the mine, by night, so that work never ceases. Fences, electrically charged, armed guards, barbed-wire entanglements and other safety measures discourage thefts, and the workers, usually natives enlisted for periods of months or a ‘year, are herded into fenced villages, searched night and morning, and guarded as close- ly as though in prison. South Africa has strict laws against il- licit diamond buying, but in spite of laws and the precautions taken, “I.D.B’s.,” as the buyers are called, continue to flourish, for a stone worth thousands, even in the rough, is easily hidden and hard to find. One of the larg- is large enou work of getting out the soft clay begins. As dug from the mine it is of puttylike consis- tency, but when dried and rotted in the sun it can be crumbled and washed away. Por- tions of the dia- mond-bearing clay are left between the claims at the start, est of the diamor mines—the Pre- mier, of Wesselton —was not so very long ago a rubbis! heap for a near-] township. H: the diamonds at extracted is an terestingstory. 1! blue clay holdi: the gems is dumpe into bins and con- veyed in electricall) to serve as roads over which the mined earth can be hauled to the dry- ing grounds. Later the roads are blasted away, tall spars erected all around the deepening pit, and tramway buckets, run- ning down to each claim, haul the mate- rial to the surface. A big pipe is covered by a network of tramway lines, each indi- vidually owned. System arrives when the big operators step in, buy up and consolidate all the claims. In the center of the pipe they sink a fifty-foot pit, and begin blasting away its sides, working steadily outward toward the rim. When the work has progressed Stages in Cutting: Rough Diamond, Rough-Sawed, First Shaping, Lopped Four-Square, Eight-Square and the Finished Brilliant driven cars, ru ing on an endle track, to the floo: of the receiving grounds. In the famous de Beers min¢ these grounds stretch fdr four miles, a: each floor can take 50,000 truck loads. this clay, the rough diamonds may be big as walnuts, but they are invisible e\ to people walking over the ground. Now, the blue stuff is broken up a! hauled to washing machines. There volving arms on a vertical shaft, tip; with great steel teeth, force the diamo1 to one side, while the thin mud is s! from the center through an outlet. | diamonds are put into trucks with loc!

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POPULAR MECHANICS e =< % Ages cy “ Kafr Workers Washing Diamonds Out of the Blue Earth at a Crude Diamond Mine: in the Big Syndicate Plants This Is Done by Machines That Automatically Rescue Every Tiny Stone ers, and taken to the pulsator, to be sifted into five sizes. \ curious story is told of the origin of his diamond searcher or “greased pul- ” tar or,’ which is an agitated canvas unerr- ly picking out gems from the dirt ssed over it. Anh engine man was oil- machinery when he happened to thrust greasy hand into a heap of crushed ue clay. On going to wash his hands, he und the blue dirt had vanished, leaving ‘diamonds sticking to the grease on his nds. This was the origin of the pulsator ch does not miss a diamond even if no rer than a pin’s head. When the diamonds have been sepa- ted, an armed guard takes them from ‘ sorting table to the general offices of mine where they are handéd over to valuators. These experts clean the ms by boiling them in nitric and hydro- oric acids. Now comes the business of sorting the nes, in size, color and purity, before pping them to New York or London. e finest are “pure stones known as goods, brown goods and spotted goods.” Next in value come those known as “pure cleavage, broken acles,” stones, naats or man- and lastly the flat triangular crys- tals called “bort” or without which America would never have had the Panama canal, bort being used to point the diamond rock cutters and drills for the excavation of the Culebra cut. The purest scintillate brilliant prismatic hues, transparent “carbonado” with and are colorless, diamonds “white But they are very rarely found, often the finds with brown, and tints, showing that mineral impurities are imprisoned in the crystals. Nevertheless, an impure diamond may be many times more valuable than a pure one, if it shows crystals known as stones.” for more “smoked” them y ellow digger gray But these col- ored diamonds are not popular with the digger because they resemble the bits of and quartz he daily throws away, and when he does find a col- ored or “mongrel diamond” he torments himself with the thought that he may have a red, green or blue glow. colored valueless

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822 cast on to the scrap heap many like it. “A blue diamond,” said a digger recently, “pinches the pipe,” meaning that the promising pipe or bed of stones, will yield no more valuable gems after a blue dia- mond has been found. One can make the diamond radioactive so that it will shine in the dark and turn olive green in hue. The method of doing this is to imbed the stone in radium bro- mide, and the luminosity lasts for twenty years. Diamonds will also shine in a dark room after they have been exposed to sun- light. Sir William Crookes exposed a dia- mond to a high-tension electrical charge, passed through a vacuum tube, and found it phosphorescing in brilliant colors. Many of the most famous diamonds are associated with stories of stark tragedy, and shrouded by superstition that they bring bad luck. Take the famous Regent or Pitt diamond which now dazzles the eyes of women who see it under a glass case in the salons of the Louvre, Paris. It was found by a slave in the Parteal mines of India, 225 years ago. To hide it, he cut his leg and concealed the stone in the bandages. It was a 410-carat gem of priceless value, and the slave ran for the coast, where he crept on board a ship, giv- ing the English skipper the diamond in return for his liberty and a small sum. Once out at sea, the skipper threw the poor slave overboard, and later sold the diamond for $5,000 to a prominent dealer. The captain spent his ill-gotten loot in POPULAR MECHANICS drink and died in delirium. From the dealer, the diamond passed to Thomas Pitt, governor of the Anglo-Indian Fort St. George, who paid $81,600 for it. Pitt cut the stone and had it polished at a cost of $25,000, selling the dust alone for $75,000. Then it became a French crown jewel, and when the revolution broke out, it was hidden in a ditch, but a thief re- vealed its whereabouts to save himself f: being guillotined. Napoleon Bonaparte used the gem to raise a loan from the Dutch government. The Orloff diamond (194 carats) was stolen by a French sailor from the eye of an idol in a Brahmin temple. From hi: it was stolen by a ship’s captain who mur- dered him to get possession of the grea jewel. Finally, Prince Orloff bought for $4,500,000 and presented it to Cather- ine the Great of Russia. Then there is the ravishing Sancy diamond of 53 carats, last known to be in the palace of an Ind prince. It passed successively through thi hands of Charles the Bold, de Sancy, t! queens Elizabeth and Henrietta Maria England, Cardinal Mazarin, and Loui XIV: It was stolen in the French rev: tion, but came to light in the hands o king of Spain, from whom it went t Russian prince. The Nizam of Hyderabad paid $2,000,000 for the famous Victoria diamond, whic! weighed 180 carats. But the largest d mond ever found is the Cullinan gem 3,025 carats, from the Premier mines. A Train of Locked Cars of Diamond-Bearing Earth En Route to the Washing Plant, at Kimberley, the World's Most Famous Mine; Note the Stored Diamond Earth in the Background

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POPULAR MECHANICS RUMBLE FROM OCEAN’S FLOOR CLUE TO LOST SHIP? sunken ships be located by of the noise they pro- in scraping over the "'g floor? The possi- is suggested in an discovery by Lieut. Maher while mak- eovernment coast s at the mouth of Columbia river. ikelv Prince of Wales beside Bison Statue Presented to British Boy Scouts in i S¢ 5 t the sound likely Memory oi Unknown Lad Who Helped American Tourist AM , A me er produced by the ting ofa ship’s hull on the floor of the UNKNOWN BRITISH BOY SCOUT Search of the records furnished no HONORED BY AMERICANS lue to any ship sunk at that place, but it decided to use drag lines to establish Years ago, an. unknown boy scout he source of the sounds. helped an American tourist. His kindly action is reported to have led indirectly pepe Ihe ana «conor ee ee of this rs 7 HOLDS COMPLETE OUTFIT roca tapsintes r) ad, a bronze statuette of a bison was presented iny so-called — 7 last Fourth of July to the scouts of Great ket shaving Ary Britain from those of America. It was carry only wy . ; received from Ambassador Houghton by of a set, but = : | the Prince of Wales on behalf of the etal, marble- — British organization. The monument hed cabinet stands in Gilwell park, near London. on the mar ns See. | CEMENT IS TESTED WITH FOGS pic rac aaggener : PRODUCED IN LABORATORY , cream and too. The _ . » assembly takes up but little room » traveling bag. Fogs rivaling those occurring in nature are directed against cement samples in a laboratory for testing and curing the ma- terial. The room is equipped with atom- want all our readers to write us izers which blow a current of compressed ly and often whenever they wish ad- air through a stream of vater. The thin nal information on articles published mist created can be regulated to varying his magazine. Address Bureau of In- degrees of density. A steel door prevents ation, Popular Mechanics, Chicago. the fog from entering adjoining rooms.

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POPULAR MECHANICS drops about two poun between eight and ei¢ thirty o'clock. That the time when so: 10,000 bees go forth the first foraging expedi tion of the day. As t! return, the weight creases five or six pou: reaching the heaviest point at sunset. This is partly due to the pr ence of the bees ani! the large amount water in the nectar. workers get rid of mu of this by vigorous ning with their wi In the afternoons, wh the sun shines, there Where Eun and Instruction Are Combined; Clown Giving Children a Lesson another drop in weig! in Fire Prevention and Hazards of Matches as the young bees lea CLOWN AS CHILDREN’S TEACHER for half an hour or so of exercise. Ot WARNS OF FIRE DANGERS slight drops, which are not regained, cur when large numbers of old bees ( School children receive impressive les- Many are tempted out by the first war sons in the perils of fire,and the best ways days and have not strength enough to to prevent them, from lectures delivered turn. Sometimes 500 or 600 will die by an expert in clown costume. To illus- the path of duty daily. One of the 1 trate his points, he uses a miniature fire teries in the life of the bees is how t engine and two gigantic matches. are able to anticipate the approach : rain. About fifteen minutes befor: HIVE OF BEES KEPT IN OFFICE shower, they come flying home, someti: . as many as 7,000 pouring through the 1 TO STUDY INSECTS’ WAYS ____ , row opening to the hive in ten 1 Interesting records of bees’ ac- utes and looking like a cyc!l tivities are kept by a college pro- | }} funnel as they do so. The sha fessor who has a hive of them of the clouds or cooler air in his office. A hole in the give them warning, some im window sash provides ac- gators believe. cess to the box which rests ne on carefully adjusted a 2 CELLULOID GUARD scales connected toanauto- . 3 SHIELDS RIDER’S matic recorder. Tem- .. WHOLE BODY perature, barometric- pressure and percent- \ With celluloid windows a1 age-of-sunshine figures } strong sheet-iron fram: are also kept. From : shield for the mot this information _« eycle rider guards charts are prepared, __ ; entire body | showing the move- rain, snow and w ments of the bees ad \. ee - ' It is intended to from day to day and aw © ford wunobstru: month to month. On : vision and will sunny mornings, the , interfere with = = Motorcycle Shield Adjusted, Showing -How It . weight of the hive tects Legs as Well as Face and Shoulders operation.

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‘his Set Tunes from Fifteen to 550 By FRANK ,E of the most interesting receivers Popular Mechanics radio laboratory ever experimented with, is a simple --tube set employing five interchange- coils of the plug-in type. Bringing tant stations on the short rebroad- vaves in the daylight as well as after with great volume on the loud ker, this set proved a. real surprise. can be instantly changed over for tandard broadcast wavelengths 1y merely changing the coils. eral of the larger broadcasting sta- in this country as well as abroad are ending their programs on two sepa- vavelengths. For example KDKA, burgh, operates on a regular wave- th of 309 meters and at certain times adcasts the same program on 64 me- o that it may be picked up by its station KFKX, Hastings, Nebr., and roadcast on 288 meters. The short es do not seem to be greatly affected daylight or atmospheric disturbances | cover a very wide range, being picked up in th Africa with good ume On amateur rt-wave receiv- WGY, Sche- ctady, N. Y., broadcasts ex- perimental Oograms at irregular inter- ls on waves veen 15 and 105 meters; ', Poldhu, reland, on bout 94 meters th experi- ntal pro- ms, and G2- London, about 44 of- heard after as ters, is ht, 1926, Popular Mechanics Magazine Completed Receiver, in Which Various Types of Interchangeable Coils Are Used Meters L. BRITTIN 11:00 p.m. Several of the Australian, Eu- ropean and South American stations may also be heard on waves between 30 and 50 meters. The three-tube set to be described is easy to build, and, as the front panel is only 7 in. wide and 18 in. long, takes up very little space. The front-panel and subpanel layouts are clearly shown in the illustration on the color page; it is im- portant that the detector-tube socket be of the shock-absorber type for eliminating microphonic noises. The grid condenser and leak are mounted in spring clips so as to be readily removable, one end of this mounting being screwed to the detector- socket grid post. For the short waves, a .0001-mfd. grid condenser and a gridleak of from 6 to 9 meg. will give the best re- sults. On the ordinary wave bands, when using either of the two larger coils, better results will be obtained with a .00025-mfd. grid condenser and a gridleak of from 2 to 6 meg. resistance. In a set of this type every effort must made to obtain short leads. To this end, the a.f. trans- formers used are constructed with removable bands or brackets; the latter be- ing reversed and the trans- formers turned upside down so as to bring the terminals to the panel. The base for the plug-in coils is shown in its proper position, and the primary coil mounted be close su b- 825

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POPULAR MECHANICS -———_ | .00025-MFD. = VAR.CONDENSER ~> LS 43 -VOLT C-BATTERY |© 25-OHM .00014-MFD. _ RHEOSTAT VAR.CONDENSER 44 ~ MOUNTING BASE PLUG-IN GRIDLEAK FOR PLUG-IN COILS / AND CONDENSER \ ADJUSTABLE PRI. COIL Xo BRACKET - 3e SUGPANEL __—> Pre” FRONT PANEL AND SUBPANEL LAYOUT SUBPANEL “ BRACKET AERIAL | BATTERY CONNECTIONS ~T A-BATTERY B-BATTERIES Above, Simplified Wiring Diagram, with All Instruments in Their Relative Positions; Below, Front-Pane and Subpanei Layouts with Battery Connections Shown at Lower Right on this base may be adjusted for the best coupling with either a short or long aerial. This coil is permanent on the mounting; the plug-in coils are complete units, each consisting of a grid and plate inductance. The circuit used is of the “fixed tickler” capacity-controlled type, which is best suited for short-wave reception and also gives excellent results on the stand broadcast wavelengths when the pro coils are used. The wiring diagram given above the instrument layout, is extremely simple to follow. Solder lugs should be used under all termin A schematic diagram is supplied for th: who prefer it to the simplified form.

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POPULAR MECHANICS 827 connect the batteries and place the tubes in the sockets. Three 201-A, or similar tubes, are used; plug in one of the larger short-wave coils and test out the set. Fac- ing the receiver, the con- denser at the left is the tuning control and the one at the right the feed- back control. This feed- back is not critical and ng Down on Subpanel; Right, er- Subpanel View, Showing asts and Method of Wiring fore wiring the set, ully examine the pho- f the completed set; ipper one shows the hod of running the through the sub- . and the direction of vires can be easily ed by referring to inder-subpanel view The rheostat controls the detec- the set will be found easy to tune. If the be only, and ™%-amp. ballasts are set howls, the capacity of the grid con- to control the filaments of both am- denser must be raised and the value of ‘tubes. These ballasts are mounted the gridleak lowered. he underside of the subpanel by means When balancing the set, it is well to dis- hort brass machine screws. At the connect the aerial; then try various com- ‘edge of the subpanel a strip of brass, _binations of grid condensers and gridleaks, \2 by 2% in., bent to form a bracket, as tubes vary and short-wave sets are in- sunted as a support for the subpanel clined to go into oscillation with a bang he center. If the set is to be mounted or howl, instead of the usual hiss. If the cabinet, see that there is clearance for _ set is still “touchy” on the low waves, it e adjustable primary coil, so that, when may be necessary to change the detector, ed in a horizontal position, it will not grid return, or bias, to negative instead of ‘+h the side of the cabinet. Now, with positive, as it now is. However, this is receiver wired and ready for operation, not likely to be necessary. When the best MATERIAL LIST Aero coil No. 4, 12 nt panel, 3-16 by 7 by 18 in. l 5 to 250 meters subpanel, 3-16 by 7 by 18 in. 1 Aero coil No. 5, 235 to 550 meter Benjamin subpanel brackets. 1 4%-volt C-battery, large type pring-suspended socket, X-type. 1 Sangamo fixed condenser, .0001 mfd sockets, any good low-loss, X-type. 1 Sangamo fixed condenser, .00025 mfd Jefferson a.f. transformer, type 41, 1% to 1 ratio 4 gridleaks, cartridge type, 2, 6, 7 and 9 meg Jefferson a.f. transformer, type 41, 3.75 to 1 ratio. 1 combination grid condenser and leak mount Karas S.L.F. condenser, .00025 mfd. removable-clip type Karas S.L.F. condenser, .00014 mfd. 6 binding posts with engraved tops Samson r.f. choke coil. + 2-ft. lengths of round, tinned-copper busbar wire Daven ballasts, 4 amp., or Amperites of same 3 doz. soldering lugs, long, round-hole type value. 12 6-32 round-head brass machine screws, 1 in open-circuit jack, short type. long 5-ohm rheostat. 12 6-32 round-head brass machine screws, ™% in | push-pull filament switch. : long. et Aero short-wave coils, 15 to 133 meters, com- $4 6-32 round-head brass machine scr » 3 in plete with mounting base. long (nickelplated)

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828 grid condenser and gridleak have been found, check the short-wave coils and make sure that the set can be made to os- cillate smoothly from maximum to mini- ,~-A.F.TRANS.- =, | 6 ' ’ Bt “Bt90 DET.45 Schematic Circuit Diagram mum on the tuning condenser, without howling. Either a long or short aeriai may be used for short-wave reception; one wire 50 ft. long gave excellent results. If the aerial is long, the primary coil must be loosely coupled or the set will not work uniformly on all wave bands. The cou- pling is loosened by moving the primary coil farther away. A large wiring diagram may be had from Popular Mechanics Radio depart- ment, 200 E. Ontario street, Chicago, for 15 cents. Specify blueprint No. 115. Handy Multiple Connector for Use in Experimental Circuits Multiple connectors for making quick connections in experimental hookups save time and enable the experimenter to try out a variety of circuits. They may be made of brass wire, wound in the form of a spring. The coils are closely spaced and the ends tfirned into eyes with a pair of pliers. The connector is then mounted CONNECTOR Detail of Coil-Spring Connector, and Mounted on Set with Leads in Position POPULAR MECHANICS on the baseboard at any convenient point by means of two small screws. The wires terminals and connections are simpl\ forced down between the coils, where they hold firmly. The best size for average use is made of 16-gauge brass wire, wound i: a 3%-in. coil, about 1% in. long. Socket Voltmeter Made from Discarded Tube Base A useful socket voltmeter can be mad from a small pocket voltmeter and a d carded tube base. The glass is remove: from the base, leaving the wires from t!] filament prongs intact. Two small dis] of wood are then turned down, one fit snugly in the top of the socket, shown, and the other slightly larger t form a cap, and the disks are glued t gether. then drilled in tl disks, one just large enough to take tl terminal on the case of the voltmeter, ai the other, in the edge of the larger dis} to receive the cord terminal of the volt- meter. Small pieces of met- al tubing, to which the tube - prong terminals have been sol- dered, are then forced into these holes. The inside of the tube base is filled with wax, which can be taken fri the top of a discarded B-battery if desire 3efore the wax has cooled, the woode! disks are forced down on top of and the base. Forcing the voltmeter termin into the metal-lined holes completes t! instrument, and it may now be plugs into the sockets of the receiving set. 1! rheostat is then turned up until the v: meter needle gives the proper reading the tube that is to be used. Checking t tubes in this manner does away with guesswork and greatly prolongs the life the tube by removing the danger of exc« filament voltage —L. M. Curtis, Ven California. Holes are FILAMENT / PRONGS

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A Radio Cabinet of Striking Design By EDWIN M. LOVE 7 (E unusual is achieved in the radio ibinet described here—beauty of de- combined with strength and dura- yet so simple is the construction : the most inexperienced amateur can it. While arranged especially for by 18-in. radio panel, a shorter one ld be used by widening the battery -es at the ends, or a longer, by extend- ing the cabinet itself. The speaker shell is 12-in. cone speaker. (See Fig. 1.) (he front panels of the battery boxes, etailed in Fig. 2, are simple rectangles l-in. stock, carefully squared to 6 by On the face side of each, cut a rab- yet, Me in. and 4% in. from the ends, inside measure- ments. Apply glue to both parts, for this is the only way to be sure that all the ef- fective gluing surface is used. Across the tops of these cleats glue and nail spreaders of % by %-in. stock. Cut a piece of 1 by 1-in. net stock, 18 in. long, and plow a “4e-in. groove, % in. deep, % in. from the front face, to receive the lower edge of the bakelite panel. Cut this to fit between the front panels, and glue in place on the bottom. For the vertical panel strips or stiles, use stock 4 in. by 1% in. Flush with the panel edge of each front battery panel, glue ona

r ep (or = *: stile; and

itever +H x ckness he panel is) nd % in. ide; and emem - ring that

| : | END PANEL § _ PARTITION : 1 glue flush with the back edges of the end- pieces their stiles. These

e two need only be weighted in

ust be

place until CORNER CONSTRUCTION

asa chisel

the glue is \ dry. Nails

notch

‘ore are unnec-

» upper end 4%by % 44 in., to rry the of the -FRONT PANEL FIXED RAIL i LOOSE RAIL~” ‘|. -STILES & RAILS FALSE | GLUED TO #°FLAT STOCK! = BASE MOLD-,

4 | 4 * | essary. For the corners, miter one | edge of each to fit. Tack

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<The tes FRONT ELEVATION nd panels, own in Fig. 3, are 344 by 8% by 8 in. Make the back of pine, 3%4 by 8 by 28 in., and the bottom, 4% by 93% by 30 in. Nail the ends to the back and the front panels to the ends, inclining the nails in various directions to increase their hold- ing power, and the bottom to the lower edges, allowing it to project % in. at the ends and front; or, if preferred, tack the parts together and insert %-in. hardwood dowels in holes bored from the outside. Now cut four %4 by 3%-in. strips, 7% in. long. Glue these inside the front panels and back, perpendicular to the bottom place by toe- nailing from the top ends and through the lower ends where the base mold will cover them. Allow one member to dry before gluing on its mate. Now glue the upper and lower rails in place, using stock ™% in. wide for the upper and 1 in. for the lower. Cut these pieces long enough to require firm pressure to force them back, but not so tightly as to crush the edges of the stiles. When all is dry, smooth the joints, and miter around the ends and front of the bottom a base mold, 1 in. wide. This mold can be made by hand, by following the steps indicated in Fig. 7, making two suc- A SECTION THROUGH A-A Fia.4 829

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POPULAR MECHANICS "SQUARES ~ pe nana. Tare STILE IN PLACE 15 . 7] 6 as | (RABBETTOFIT, | ; | 4 \ \ ‘ff BACK $X8X 28 FRONT PANEL \ el a BOTTOMZX93x 30" x \ END PANEL ONE PAIR REQ. Fic.2 Fic.3 & UPPER RAIL SECTIONS DEVELOPMENT OF BASE MOLD Fic.7 Y FS

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POPULAR MECHANICS e rabbets and finally working out urved part, or a suitable mold may be iased at a picture-framing shop. ike a loose rail, as in Fig. 7, 19 in. %4 by 1 in. with a %e by %-in. ve % in. from the face edge, and a % .-in. tenon centered on each end. he lid is %4 by 9% in. by 2 ft.6in. It be made of solid stock, if well oned, but a five-ply piece ir better, as it will not ». Only the upper need be figured terial (see Fig. 8). ke a % by H%-in. ing mold, which mitered around ends and front, pping down from top face “46 in. show a margin. s may be tacked th 1-in. brads, driven rough the cove, since erwise it is quite diffi- t to keep it in place un- he glue is dry. As this es a thin edge of the mold projecting ww, the surface must be built up by iing to the underside a “6 by 1-in. strip, it all around. rries the hinges. Make the speaker grill of 3¢-in. three- stock. Lay out a piece of tracing pa- r,7 by 14 in., in 1l-in. squares, and, fol- ving the intersections shown in Fig. 1, lraw one-half the design. Notice that all nes of the stems are continuations of the nl circles and tangent to them. No two ms are the same width, and they vary width throughout their length. The ives spring from the stems on a tangent. Draw a 14-in. circle on the stock, and divide with a vertical diameter. Trace the half design, turn the pattern over, and race the other half. Bore holes through each part to be removed and use a bracket to cut them out. Smooth the edges with a fine file and sandpaper, being care- i! not to chip the corners. Obtain three strips of %-in. veneer, 45 long, one 5% in. wide, the others 33% If veneer is hard to get, gauge a piece l-in. stock, and ripping alternately from one edge and the other, cut a thickness. Smooth the stock, and repeat. Plane off The back strip running 831 high spots in the veneers thus produced. Make a back of three-ply stock, 14 in. in diameter, and cut out a disk 12% in. in diameter. Lay the finished grill, face downward, on 3%-in. strips on the shop floor, or on some other surface where nails can be driven. Drive several nails against the edges of the cut-outs, so as to brace the grill for edgewise pressure. Have ready a stout cord, and bend around the grill the wide piece of veneer. It may be necessary to soak the stock in water before it will bend to the sharp curve. Cut off the surplus length and bind the cord around the veneer until it is drawn tightly against the grill edge. Bend a second piece of veneer, 3% in. wide, around the in- side, and cut off the extra length. The joint need not be closer than %e in. Bend a third piece of the same length and width inside of that. Now take out the liners and coat the inside of the outer veneer with liquid glue. Coat one side of a liner, slip it into place, with the joint at the top, coat it inside, and coat the third piece, which in turn is put inside. They will not fit snugly to- gether at this stage and the upper edge will be lopsided. Press the liners down against the grill, and slip in the back disk. sind the veneer tightly against this, as well as the grill, which should bring it to a disk throughout. Then slip blocks, 3 in. wide, through the opening, press to the sides and wedge up with other blocks, un- til the veneers are well clamped together. Weight the assembly to eliminate possible twists, and allow to dry thoroughly. After the glue has set, remove back, grill and clamping blocks. If there are any appreciable openings between the layers of veneer, mix thin glue with plas- ter of paris and run down into the spaces. Cover the back of the grill with tightly stretched silk, or fine-mesh bronze screen, using %-in. tacks to hold it on, and glue the grill into the shell. The back is held

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POPULAR MECHANICS ; en LID, WITHOUT NOSING ( 5-PLY SPEAKER SHELL DEVELOPMENT OF NOSING on with small screws after the speaker is installed. Joint off the shell until the pro- jection is % in., and round the corners. Make the bracket pattern as shown in Fig. 9. If the brackets are to be sawed out by hand, use 1-in. stock, make six, and round off the corners of the curves to a radius of % in. Glue together in groups of threes. Smooth with a file and sand- paper. If they are cut with a bandsaw— any mill will cut them very cheaply—glue up the three thicknesses before cutting. The speaker support is made from stock 134 in. net by 21% in. Lay out the upper surface of the lid for the bracket mortises, 2% by 534 in., 1 in. from the ends, and centered on the width. Stand the brackets on these spaces and trace around with a fine-pointed pencil. Then, with a sharp chisel, cut % in. inside, and hollow out to a depth of % in.; trim to the line, trying the brackets occasion- Fic.9 ally to see if they fit. Size the ends, a: glue into the mortises. Center the speaker support between t brackets, gluing and nailing it, and bot for the wires. Put the shell in positior and nail it to the support. A tack 1 also be driven into each bracket. To furnish sockets for the candles to the tops of the brackets pieces of | in. round stock, bored with 34-in. holes Remove all traces of glue, and sand w¢ before staining. This design is suita for either plain or two-tone finishing for gesso and polychrome work. @Squeals and howls caused by bod) pacity may be eliminated by shielding | back of the front panel with tin or cop; foil. This foil must not short any inst ment; ground the shield and the cores the amplifying transformers to the nes tive terminal of the A-battery.

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POPULAR MECHANICS rrect C-Battery Voltage Important rect C-battery voltage in the audio- fier circuit of any receiver is im >or- Che battery should have the proper ve in order that the amplifier tubes receive the correct grid bias; an in- The ttery voltage should be increased if ect value will cause distortion. B-battery voltage is raised, as in the tice of adding a power tube in the last that the normal total ttery voltage was 99 before the power vas added, and a 4%-volt C-battery the power tube should have a oltage of 135 and at this voltage a It C-battery must be used. The proper iltage for the tube is specified bv the ufacturer and Assuming used, should be followed ‘ " etullv tor best results. Model House Wired for Radio wired for as recently designed by home, correctly one of rge radio manufacturers. The posi- i the various sets and loud speakers las the method of wiring are clearly in the illustration. Note the out and the battery floor. room, the baseboards, remote- compart- The loud may be into the porch circuit if desired. and second cer, in the ed switches on the 1 living Positions of Sets and Loud Speakers; Switches and Battery Compartment The aerial, from the point where it enters the building, is inclosed in conduit in the walls. Many new homes and apartment buildings are now being wired for radio, and this model home was designed for the purpose of properly guiding the builder. Piug-In Coils for Short Waves Plug-in coils are now available for short-wave receivers. The set shown in Interchangeable Plug-In Coils, Showing Coil Plugged into Mounting at Rea: the illustration consists of three inter changeable coils and a mounting on which is placed an adjustable primary coil. The coupling of the primary coil may be set for best results with either a long or short The 1 1 aerial. interchangeable coils each have a grid and plate inductance and cove 15 to 130 meters. Coil 550 meters may be obtained if desired from range

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Fixed-Condenser Kinks By WM. CALVERT HE fixed condenser is a necessary adjunct to most re ceiving circuits, but the part it plays is not always clear! understood by the average builder. They are often used random by the experimenter, many times with surprising results. When properly used, fixed condensers are a sp cific remedy for many inefficient sets and may also be used to eliminate troublesome interference. While pointing out the various purposes for which th: may be used, it may be of interest to take one apart and how it is made. Available in all sorts of shapes and ca pacities, the construction is practically the same in types; alternating sheets of tin or copper foil and mic make up the unit, the capacity de pending on t! size and num! of the metalli sheets, kind of insu lating material and.the method of ‘AERIAL construction. The capacity is carefully measured by the man- oe eae reat ufacturer and stamped on the | unit; if carefully made and pro- tected from moisture this capacity does not vary. The small types shown in the illustration are spe- cially designed for radio use; larger types capable of with- standing high voltages may be used for eliminating interference from electrically operated devices, such as electric fans, motors and battery chargers. The method is clearly shown in the illustration, Fig. 1; two 2- ‘ mfd. condensers are connected in | : Bees cc series across the power line near he sa the apparatus that is causing the ‘ : trouble. The center point, or GROUND common connection between the ¥. || “GROUND two condensers, is then grounded (|iieail FiG.2 : Fig.3 834

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water pipe, as shown in the diagram. en connecting fixed condensers of AERIAL small type in radio sets, never apply iron directly to the condenser; use ering lugs and fasten them to the lenser by means of short brass ma- ne screws. If the condenser is to be ened to some piece of apparatus, such transformer, it is advisable to use rt metal strips drilled to take the ling posts and machine screws, as RECEIVER vn in the photo. A .0005-mfd. con- AMP. DET nser placed across the secondary of | Be or eM A- last a.f. transformer will often elimi- te the high-pitched whistle in the loud iker caused by the a.f. amplifier. In _ ee |. MFD. FIXED me cases it is advisable to place the “CONDENSERS - condenser across the primary of the sre transtormer; try both positions , best results. Shunting the “FIXED CONDENSERS ud-speaker jack with a con- nser, as shown at right, often give better re- Its in tone, per- tting the speaker to reproduce a wider range of frequencies; this condenser may be .001 to .006 mfd. The experimenter often wishes to reduce or increase the capacity of variable condensers, or change the inductance value of coils; this is easily done with fixed con- densers. By shunting a fixed con- denser across the inductance, as shown in Fig. 2, the wavelength of the circuit will be raised; if >PRING~METAL CLIPS this condenser is variable the A.F. TRANS. wavelength may, of course, be varied at will. However, in most cases, with simple sets, it is only necessary to raise the wavelength to a certain point and a fixed con- denser of suitable capacity may be used as shown. For reducing the inductance value of a circuit for shorter waveiengths, a fixed condenser

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POPULAR coil and and even more flexibility may be obtained by em- may be used in series with the me antenna, as shown in Fig. 3, ploving several capacities, as shown in Fig. 4, a switch being used to change from In tuned cir- cuits of this type such a method is advised one capacity to the other. to easily adapt the set to aerials of various lengths. It is common practice now to place the various batteries at a distance from the set that they of sight. the basement or in a near-by in order may be out They are often placed in closet; long leads are necessary in either case and the as well noisy operation due to the pick-up of the leads. This may be remedied by the use fixed condensers various batteries ; as result is a loss of selectivity of for by-passing the these by-pass condens- ers should be placed across the leads at the set and not at the batteries, fect will be lost. either .5 1 mfd. Fixed or the ef- By-pass condensers of may be used for this condensers are not ex- pensive; they are one item used in the construction of radio set that has dropped lower in price than any other. In the early days cost as high as $25; or purpose. a precision condensers now even better units may be obtained for from 40 to 75 cents. Device Designed to Reduce Interference and Static A small instrument designed to assist in tuning the set so as to eliminate inter- ference and reduce static has appeared on the market. It is especially recommended for warm-weather reception when static interference is most prevalent. It is com- posed of a tuning coil which is balanced by a small variable condenser, providing an additional means of tuning for any tube or crystal set, excepting sets which are operated on a loop. The numbered ter- minals on the instru- ment are for the var- ious connections in the dia- One way of using the unit is by induction and the other by absorption; the method is given grams. * wnpucTiON METHOD latter Interference-Eliminatin in Which It May Be Used MECHANICS The capacities required for most cuits are always specified, althoug! experimenter often finds that a greate less capacity than that specified is nee The change of required, be due to the experimenter’s location, use of parts other than those called or the placing of parts on the basebo In cases of this kind, it is usually ne capacity sary to try a number of condensers bei To fa tate this testing operation, a pair of s1 clips, the correct capacity is found. made of light spring metal, may bent in the form shown in Fig. 6 and to the busbar thus di away with the necessity of soldering dered vires, unsoldering each condenser tried. All fixed condensers are not adapta to this method, but for those that ma clipped in and out of the circuit, these lit clips are very useful. constructed so that it cannot be used this manner, short lengths of busbar \ If the condense may be soldered to the circuit leads inst: of the clips; lugs are then soldered to 1 ends of the short wires so that the denser may be screwed in position short machine screws. It simple operation to remove the screws put in a condenser of different capa: brass for the reduction of stati it slightly reduces the The induction method will assist and prove the volume, it is claimed. advised though volur Testing Dry-Cell Batteries Dry cells vary in amperage accordin the make, but the usual cell should re« ter from 30 to 35 amp. when fresh. ammeter should be used for testing <d cell A-batteries, and is to be left in circuit just long enough to obtain reading. Care sho be taken that meter conr.e’ properly. lic nected backward, pointer will flected off the s in the wrong di! tion. If the read is below 10 amp is be ABSORPTIo METHOD '

Device, Showing Two Ways cell is worn out.

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MAKING THE GERMAN RADIO PLAY REALISTIC Flowing-Water Ar- gement for Imitating Rain, ng Water and Dashing es; Right, Motor-Driven e lor Imitating the e of a Ship Propeller; Wind Machine Con- ng of Cloth Stretched a Wooden Drum; When tated, the Spokes on the Brush against the 1 Producing the Effect of Breezes or High Winds Left, Oxygen Cylinder Used for Pro- ducing the Illusion of Steam Dis- charged from a Locomotive; Center, Table with a Number of Devices for Various Noises Such as Table Bells, Telephone Alarms, Ventilators and Signal Horns; Right, Special Appa- ratus for Producing a Number of Animal Sounds, and Bells }

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POPULAR MECHANICS Simple Power-Control Switch the other input wire on trickle charg and the second to the wire on the B-eli eee inator. With a snap-switch the eliminat xan and charger will alternate on or off w VOLT LINE--% —— A each snap of the switch. If the flush pus : ] button type of switch is used, pressing « button will shut off the charger and co nect the eliminator, in which position t set can be operated. Pressing the ot! button will shut off the eliminator connect the charger. It will be seen t! the filaments of the tubes must be operat: independently by the filament switch the set, or by turning the rheostats to t! off position, if the set is not equipped wit a switch.—E, J. Bachmann, Fullerton, | TO TRICKLE ys TO “B” EUMINATOR Button and Match Make Variable Gridleak The radio fan can always find use fo: variable high resistance; and nothin; could be simpler to make than the ur shown in the drawing. It can be us either as a gridleak or for the resistanc: coupled amplifier. It is also handy stopping howls in a.f. amplifiers, and controlling volume. The construction shown in the illustration, and the cost B-ELIMINATOR practically nothing, as the unit is mad from a match, a button, a bit of brass she: ene 5 yt —— and and a little India ink. The head is « from the match, leaving the stem 134 A simple power control for trickle jong: starting from the end of the mat chargers and B-eliminators may be ob- about 1% in. is heavily coated with In tained by means of a switch mounted on ink and allowed to dry. The sheet b: the wall, or at some other convenient place. should not be too thick and should ha near the set. Power-control devices are a bit of spring to it; the manner of cutti now on the market, but forthose who pre-and shaping it is clearly shown. The but fer to make their own, this simple switch- ton is % in. in diameter and a hole is « ing device will give good service. The or drilled in it as shown. When the wu equipment consists of a three-point switch, is complet: of either the snap or push-button type, and A! —_" une sliding t the illustration shows the connections iN, - button up clearly. The switch lever and contact down chang points merely illustrate the action of this the amount snap switch and are not a part of the oa : brass in co hookup. If the house has a cellar, it is a - tact with t always desirable to place the batteries, : inked suria charger and eliminator there. When tap- = and thus \ ping the 110-volt line, one side is connect- ; ies the resi ed directly to the trickle charger, and to BRASS ance. T the B-eliminator; the other side of the line Pay unit is rema! goes to the post on the bridged contacts BUTTON ably quiet a of the control switch. The remaining two has proved satisfactory in use.—Wat posts on the switch are connected, one to. Brown, Iuka, Miss.

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AMATEUR, MECHANICS How to Take Care of Your Guns By BOB BECKER ill the items in a hunter’s outfit clean and shining and thereby lengthens othing requires so much attention’ their life. After using rifles, pistols and gun or guns. Rubber boots can be shotguns on a variety of game from off and tossed in a corner. Wet Alaska on the north to the swampy tropics hing can be hung up to dry without of the Amazon and Bolivia on the south r of rust or damage. Shells will keep (where improper or careless cleaning m vear’s end to another without atten- methods quickly and completely ruin n, but once a gun has been used afield gun), I recommend the following pro hunter’s day is not ended until the cedure if one wishes to keep his armor pon has been cleaned thoroughly and _ full of shining, straight-shooting, unfo perly. weapons: Never leave your gun Without question, more shotguns and overnight, especially if it is both we les are partly or completely ruined by dirty; use patent cleaners equipped of attention or unintelligent clean- brass-wire gauze if the barrels are ver) than by using the weapons too much. dirty; use a nitro solvent to remove resi l, in the long run, that precious in- due in the barrel; don’t spare the oil lient known as “elbow grease” is the when cleaning any gun or preparing hing that keeps one’s gun rack looking weapon for storage, and use plent A lazy man has dirty guns. The elbow grease. sportsman There are three things which the hunt- ~ I his guns o\ 2. er has to keep in mind when caring for hi weapons. First, the removal of ill powder resi- due and metal fouling eun is a rifle): second

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POrFULAR MECHANICS fi a ss } Fa \ ¥ A Bay | ‘ i fap: iy vention of rust, and third, proper oiling. The first is the most diffi- cult feat and the one in which most gun owners fail. To clean a shotgun proceed as follows: Take the gun apart and give attention to the barrel or barrels first of all. If you have been shooting in the rain, wipe off most of the water and then assemble a cleaning rod to attack the residue in the chambers. Here is where a bottle of nitro solvent is of great value. Run a small piece of woolen cloth through the slot in the cleaning rod, moisten it thoroughly with nitro solvent (which can be purchased in practically every sport- ing-goods store) and vigorously scrub the inside of the barrel. If the gun is particu- larly dirty, use a brass wire-gauze cleaner after an application of solvent, then dry flannel patches. After you have run three or four of these flannel patches through the barrel they appear to come out clean, but the wise man will moisten another piece of cloth with nitro solvent and attack the bore again. The result often suprises the gun owner who thinks the chambers are free from fouling, as this second applica- tion of solvent will often reveal black stain upon the flannel patc! which means that even though t barrels appear bright and shir there remains upon the steel an most invisible wash or plating | by the smokeless powder. this must All be removed beforé t gun is oiled and set aside as a f After this solvent tre ment, the gun owner should foll with dry pieces of flannel until t ished job. last one moisten comes one with out a clean. thin The gun

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POPULAR MECHANICS scrub the bore in order to a coating of protective oil e steel. If the gun is to be side for some time, it is best nish with a heavy grease. to play safe and to make sure | have removed every speck uling from the guns I have I always go back to them or two days after cleaning check up by running flannel hes through the barrels. the care of rifles, even more ntion must be given the clean- ing and oiling job than in treat- ing shotguns. This applies to small-bore guns, such as the .22- caliber, and to the high-power big-game guns, where metal foul- ing is a factor to be dealt with. In cleaning and caring for a .22 rifle, the most popular small’ gun in the United States, nitro solvent (No. 9) should be used freely. Use a small woolen rag in a slotted wiper soaked in solvent, or if the fouling has be- come caked in the bore, pour a small amount of the liquid through the barrel before introducing the cleaning patch. Start the rag from the breech of the gun and not from the muzzle. Another point to keep in mind is that the cleaning patch should be allowed to follow the rifling of the barrel. If you force a swab time after time across the rifling vou may ruin it. This means the shooting qualities of your gun are gone, as perfect rifling is essential to accuracy. Likewise, even a slight burr on the muzzle of the arm will impair its accuracy. Hence the l ‘lean the bore from the breech and n from the muzzle, where one is likel) inflict a careless knock with the cleaning rod. In cleaning a .22 rifle which. contrary to pop ular belief. is one of the most difficult bores to keep clean and in perfect cond! tion due to the action of smokeless po

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842 POPULAR MECHANICS der, the gun owner should swab the bore with as many _ small wool patches as are needed to fin- ish with an unstained piece. The rule is: Use elbow grease until they show white. Corrosion and not the menace of high-powered guns and hundreds of finely made guns go into the scrap heap every vear because the shooter-owner erosion is does not understand how to combat the corro- sion evil, which, in simple language, means that by failure to thoroughly remove the metal and powder fouling in a barrel it is attacked by these steel destroyers and completely ruined. Ammonia is one of the powerful allies of the rifle owner, if he will only use this common cleaning fluid. Ammonia natur- ally comes into this cleaning operation because the fouling in the bore of a high power rifle is usually acid due to the com bination of powder and primer explosion. i No mere scrubbing with woolen rags removes it, nor will the common thin gyn oils touch itasarule. To remove this residue from This fouling is very tenacious. the bore of a high-power rifle, where there are no lumpy bits of metal fouling, strong ammonia, containing not less than 28 per cent ammonia gas, is required. Thorough- ly scrub the with pieces of bore several wool cloth soaked in this fluid and th: run two or three through the barrel dry it. Follow this treatment with t oily patches, and the bore should be good shape However, the next day be ter repeat this treatment so as to be that the barrel is absolutely clean. The hunter afield to sho smokeless-powder shells with lead-all bullets encounters another difficulty w! it comes time to clean his weapon. must not only remove the fouling wl comes from the powder but the lead posits which have been laid down in bore by the bullets. This condition called “leading.” Sometimes you will it in the form of tiny lumps or scales, a sometimes you won't see it at all, as it tal who goes

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POPULAR orm of a well-nigh invisible plating. emedy this condition, first clean the with ammonia by scrubbing it thor- ly with pieces of flannel rag soaked Then dry it by running several more hes through the barrel. Next smear il cleaning patches with mercurial ent and scrub the bore with them, running a rag heavily coated with ment through the barrel so that the will be thickly greased when you put vay. After 24 hours this procedure uld be repeated. a rifle barrel has been neglected for e time and rust has taken hold, there chance that the bore may be restored he use of a metal anti-fouling solu- and a rust remover. Place the gun vertical position, pour through it 1 boiling-hot suds. scrub it vigorously with a flannel moistened with soapy water. Run or three dry rags through the bore, or more of soap ou are ready for the next step. rubber cork, which fits the chamber our rifle snugly, is necessary for this eration. Cork the chamber and then with a metal anti-fouling solution, ch your druggist can mix for you. It ist be freshly made and kept tightly rked until you feed it to the rusty rifle. e solution is made up as monia containing 28 per cent gas, 3 water, 2 oz.; ammonium persulphate, »., and ammonia carbonate, 100 er. follows: Keeping Garage Doors Snug prevent the sliding doors swinging in the wind, equip them the features shown in the photo. small iron rollers are set near the just far enough away to permit the to move easily back and forth. At center two ad iron ps are friv- ed to short rods set in cement. te that each of the garage % eS Si ME Tl raps is : out htly. This ed Fasteners on Sliding Garage Door in the Wind MECHANICS rather a ticklish solution as it will “eat” your stock if any of it is spilled on the wood. So, watch your step when you are pouring it into the bore. Also, it rusts steel if allowed to evaporate on it. The solution should be left in the bore not more than 30 minutes. Then attack the bore with cleaning patches until it is dry and finally use a new stiff brass-bristle brush to loosen up the fouling that re mains. This treatment is then repeated. Next comes the use of a rust which can be purchased at a sporting goods store. Several patches of flannel covered with this dope should be run through the barrel. Use plenty of elbow grease on this operation and then clean the bore with dry patches, oil it up and you are ready to see if the old shooting This is remover, iron is going to shoot straight or bend If its shooting quali ties are not evident after this operation bullets around trees. better chuck the barrel into the scrap heap and get a new one. Just one more part of the rifle or shot gun which needs a little attention if vou This is Don’t smear it with gun oil ii have pride in your gun cabinet. the stock. you wish to preserve the luster of its fin ish. a flannel rag and a minute or two of vigorous rubbing is the successful Raw linseed oil, combination for gunstocks But for every minute put in on the stock hours must be expended on the bore and other steel in a gun. not interfere with driving the car in and out and effectively the doors from squeeze fastener does prevents swinging A Register Screen lo prevent pencils, buttons, coins, and the like from falling into the ters. 1 cut piece hot-air regis ordinary. S| en - qdoor | fit into openings Prevent It from Swinging

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POPULAR MECHANICS CLEATS HINGED LID Insulated Box for the Milk Bottle For trouble vears we have had éonsiderable during the winter in preventing our milk from freezing on the porch, and it from souring during the sum ore the bottle was ~ keepin mer, taken into trouble, | n. lumber, 9 by 9 in ' 1 ° the house. To this made a box out of 1-1 in outside measurements, and 12 in. deep with the top open. For the inside I made without toy and 10 in. deep, with a rim around the top sufficient thickness to fill up the space +] Lile ft a box » or bottom, 6 by 6 in. e of between » boxes after the smaller one was set firmly into the large one. This left a boxes. For the m between the [I took a 1-in. board, , With a 1 in. board tacked it to slide This formed the dead-air space top, two 9 by 9 in. in size underneath it the larger | lid, inside of which l e the winter, when the shut easily. rin weather out above zero, although left all 11 il in the o d: Vv. the milk did not pen Ireeze, an I d this imer it has kept nicely at 50 and 60 -\W. P rcatello. Idaho with the temperature H. Snyder Compressed Air Forces Gas from Hose Gasoline stations owning their pumps can overcome the present method of drain- ing the hose into the auto tank by the use ot compressed from ur. The air is used directly the tire-fillling apparatus and will Wooden Box with Air Space Kee Milk from Freezing during Winter a from Souring in the Summer force out the last drop otf vas from hose. Disconnect the hose and fit a on: way gate check valve to the connection at the pump, that forced back into the short nipple gasoline cal no pump. Chen i ahead of this check, drill tap a 4-in. + hole in the pipe from the hose. The gasoline hose can be attach to the end of the large nipple in the re ar manner, either by threading coupling or by a hose clamp and bolts spring shut-off cock should be insert on in the air line at a convenient point at t pump. In is fed the automobile tank in the usual manne but instead of lifting the hose to allow use, the gasoline is to drain, the air cock is depressed. to into the hose force out the residue, but the check in t allows the air flow gas line prevents the air from forcing into t! 7 PUMP Sas y- CHECK VALVE pump a back into supply tal (GASOLINE HOSE Robbins, H vich, Ma AIR HOSE @ To boil: risk it, the should be well rinsed in cold water bet putting in the milk. without of scorching

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POPULAR MECHANICS A Lard-Can Steam Cooker low-pressure steam cooker can be le at home out of a 45-lb. tin lard can. e made out of black iron cannot be Select one in good shape, with a fitting lid. Take a clean tomato about No. 2 or 3 size to make the wa- filler and gauge. This is easily shaped soldered to the lard can as shown. you wish to use two packs, you need / ht ‘46 or %-in. stove bolts, 1 in. long, sixteen washers. The first row of is evenly spaced around the can, 2 from the bottom, measuring on the out- e ( e of the can. Put them in as shown in detail and solder the washers and heads to the can. Make one or two racks, as shown, using No. 9 wire for rim, and 46-in. copper tubing to make neat joint. Solder the ends together. e t 7 square-mesh galvanized cloth or net- twisting the wires onto the rim so there will be no sag. The wire hoops the rack should be about 1 in. smaller ) the inside of the lard can. If you wish use pints when canning, make two 1 Cr cs. The water line should be about % 4 wy mal he ZO* —_— 3g COPPER 4 4 WIRE RACK TUBING Pressure Steam Cooker Made from Forty-Five- Pound Lard Can in. below the bottom of the jars. Ii bottom of the lard can should leak, der it all around the inside of the seam. ‘tt it u \ a % by 1-in. hole about % in. from bottom before soldering on the water ge.—Geo. H. Cappel, Wilmer, Ala. lways mix starch with soap water; - will prevent the iron from sticking and give the linen a higher gloss. Lightweight Trom- bone Mute Found Effective Lightweight Mute for Trombone Trombone players will find the light weight mute shown in the drawing of considerable value. It is made of felt of any color, although green has been found especially well suited for this purpose. The bell on my trombone is 7 in. in diam eter, so 1 made the mute 8 in. across and of two thicknesses. Draw a circle, 12 in in diameter, on a piece of felt and out of this disk make the rim that holds the mute in place on the bell. This strip is 2 in. wide and runs two-thirds of the way around the bell. Sew the outside of the rim to the outside of the center piece. When finished, the rim will stand out cone-shaped. The practicing musician will find this an ideal mute.—Irvin L. Oakes, Pleasant Hill, Ohio. Spectacles Make Magnifying Glass An old pair of spectacles can be changed to form a small magnifying glass, which is generally useful. The two eye wires are bent so that they are parallel, and exact focus is obtained by bending the nose piece so that the glasses can be pulled apart or brought together for more or less magnification.

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POPULAR MECHANICS Sign Painters’ Tool Box sign painters and window letterers are mnvenienced when working on a _— step! adder, be- Peg a. «6cause the toy ala rung does not at- ford sufficient space for their col- ors and brushes, and the least dts- turbance of the ladders causes them to fall off. One sign painter overcame the difficulty by attaching a box top of ladder as wn in the drawing. When closed, it provides a top step as material on an ordinary ladder, but opened, reveals ll tl : and with Hendrick- , ‘ials sately kept g space —G. E. Improvised Spring-Perch Holder When dr: part of the rear-axle housing to which the ng perch of a Ford truck is at- causing the end of the spring to drop down and rest on the hous- Not new piece, rear-spri tached, broke, ing. to pay the price asked the owner repaired the truck quite cheaply in the following way: for a A bar of steel, having a diameter equal to that of the rear-axle housing, was ob- tained, and a piece cut off, making BREAK --.. suffi- allow- for the lap and bend near the end. One end of the cient ance bar was lapped back, making Then a hole for near the end at The doubled hick and rigid. drilled he bend was made. Was end was bent again to ferm a right ang] as shown in the drawing. It necessary to give it a slight bend whe it rested against the top of the housing. Two U-bolts and were then made to fit the hou The U-bolt next to the per vas made a little longer than the othe one, because the doubled end of the stray necessitated the use of a longer bolt. The Was a bral two sho: straps ing. whole outfit was assembled as shown, and all nuts were tightened. While this repai: did not allow the spring to return to it former position it saved the owner tims and money.—B. Kennedy, McCool, Mis Ornamental Cigaret Holder For the library or den a novel cigar and cigaret holder can be readily made from block of soft pine and the cover of a d carded book. Peet tes Tully The bound pages are c from the and tl pine block is cut to the exact size hape of the bound pages. Four neatly spaced and of a si large to accommodate removed covers cigars and ciga re cut through the block, which is glued firmly to the back the cover. If desired, half box may be fitted snug- ly into each of the holes to improve the ap- The Cigars,” “Cigaretsa, “Ashes” and “Matches, carved of painted be- tween the holes, will add to the orna- mentation, and SOap pearance. words “* BLOCK appropriate wording may be placed cn t! outside cover. A ends staining of front edge of the block c pletes the holder.—L. M. Venic California. and Curtis, @ lf you sprinkle a carpet with salt betor beginning to brush it, the dust will 1 rise; incidentally, the salt will impro the appearance of the carpet.

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4 f, — « Ce cs. ee i | 3 ? i= ba L. SORE OLAS “SS ? “a j : eS a a as Oe * . How to Make Spatter Silhouettes Anyone Can Make Attractive Pictures by This Method Using Only an Old Toothbrush and a Knife N° special equipment is required for Pins are used to hold them in place. Le . the making of “spatter-work” silhou- cate the pins as near the picture as pos The method described here is very sible so the stencil will be held close ple and anyone can easily make very” against the paper. Other d silhouettes inthis way. All you need _ ettes will be fuzzy around the edges n old toothbrush, a penknife and some The ink-spray or spatter treatment is cardboard. Draw the outline of the applied with the toothbrush and knife ired silhouette on the cardboard and The drawing board should be placed on tully cut around the picture with the end while the spattering is being done. te. The cardboard should be laid on Poura few drops of black drawing ink on old magazine and the cutting done with the bristles of the brush and hold point of the knife, which should be 3 in. from the stencil. Draw the blade ot sharp. Follow the outline exactly, the knife quickly across the bristles. Thi the value of a silhouette depends en- causes the ink to be thro ly upon the correctness of its outline. ina fine spray. Any degree of “darkness” he paper upon which the silhouette is can be had, from e made is placed on the drawing board — black the cardboard stencil directly over it. For plain vise the silhou about 1 . wn onto the papet a light grav to alm silhouettes

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S48 POPULAR MECHANICS tone is required, one stencil only is need- described. The point of the knife : ed. But for more elaborate ones of two be very sharp to insure a clear out or three tones as many stencils as tones Profile photos can be used to make:sil] are needed to make the picture. The ettes of vour friends. Do not put very much ink on bristles of the brush at one time, for heavily loaded, it will be apt to throw s big spatters which will spoil the w he blade of the knife should be dr rapidly across the bristles so as to thr a fine spray. Do not remove the ste: until the ink is perfectly dry. Swinging Furnace Door To eliminate the necessity of cl the furnace door each time a shovelful coal is thrown 1x, a swinging door of he sheet iron will be found useful One ed is bent around an iron rod, which set as the hinge. Both ends of this rod threaded and nuts screwed on. Hols I I nace and the rod is pushed into tl rifle larger in size than the diametet he rod are drilled in the sides of the holes. The nuts are then screwed aga OP age Seow y eo the sides to hold the rod securely in pl of Spattering by Drawing Knife When feeding the fire, the shovel is sit Blade over Inked Toothbrush pushed against the swinging door lady’s head and the policeman illustrated load deposited in the furnace, and are made with one stencil. The yacht shovel withdrawn, the door shutting picture is a two-tone silhouette and two matically —E. K. Wehry, Cedar Rap stencils were required. The landscape and — Jowa. P ‘ : the floral sketch were made with one sten- TIGHTENING NUTS cil, the black parts being laid in after the _ tf spattering was done. == In the two-tone silhouette of the marine scene, the sky only was cut out of the first stencil. This left the boat, moon and wa- ter covered. This stencil was only lightly spattered over. This rendered the sky in a light gray. The boat only was cut from the second stencil and this heavily Spat tered which made the boat and its shadow very dark. Notice the head and the house In the former the object was cut out, while in the latter every thing was cut out but the object. This reverses the combination and produces an entirely different style of picture. Many different combinations can be worked out to produce different effects and very artistic pictures can be made with four or five tones. Old postal cards are good to use in small work in making the stencils. Outline the : H Sheet-Iron S$ i D in Furnace F object on the card and cut out as already Pe ee, Convenient

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wpe Your Own Q [AVE the bow lines down to the edges ing is ‘46 in. thick, and the pieces for well, ‘ the lifts. but do not finish the bow quarter, and forecastle decks are cut his stage, since a wooden stem piece _ slightly wider than the hull so that the later be fitted here. may be trimmed down after being glued he deck lines may be cut downto size in place. Cut out the four pieces. after the hull carving, follow- them in place and, at each end, mark th ¢ outline, marked side view of rough points where the edges, after the) 1 ll. The main, or well deck, inthe space ished, will come. Measure in een the forward end of the stern sec- these points, and connect the i and the rear of the forecastle, is with curved lines corresponding a, being ‘46 in. deeper at a curvature of the hull. Then halve in. tance Curves these ilable. kes excel- t decks, but lig] clear white well - ne will do in pencil, rt absence. in the deck plank- View of Quarter, Showing Rake of Bulwark and Quarterdeck, Also "ts we Paes Deck-Plank Lining Cuts. | elected piece ' = | then. | }

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POPULAR MECHANICS look old and well worn. After the lac has dried, glue the decks in place then trim the edges down to meet the | lines. It is not necessary to clamy on and wait for the glue to set. They be nailed in place with small brads or | cut down to brad size, and later the h« can be countersunk and puttied o After the decks are place, the next - SAWED OFF~. is to make the | warks ar¢ the forec top and superstructu Cut a piece %e-in. thi white pi | MAIN DECK | CURVES X% \ Upper Left. Fo’c’sle Head and Deck on Finished Model; Cen- ter, Poop and Fo’c’sle Layout; Lower Right, Photo of Stern intervals of 2 in cut and cross marks in the planking, as shown in one of the drawings, > end joints. If you wish to show the deck spikes they can be pricked in with a needle point and brought out with a sharp pencil. After all the deck planks are marked, sand the sur- face clear of dirt and then shellack it. _The sanding process will dust over the pencil marks in the grooves and dim their newness, so that the shellacked surface will

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POPULAR MECHANICS

od, a little longer and wider than tern, and glue and nail it to the stern, the top edge projecting 1 in. above leck, and the lower edge just even the point where the superstructure and the stern curves inward before the straight downward rake to keel. With a half-round file smooth the lower edge to conform to the stern e, and trim down the edges to match - sides of the superstructure. The 1-in. jection above the stern of the poop- k furnishes the rear bulwark, and the piece itself gives a better surface on ch to paint the decorations of the rn, than would be the case if the end in of the hull wood left bare. Next cut and fit the side bulwarks. lding a sheet of plain paper against the rr ne Was ee | ee a “i . —> a 2 PIECE oy AND ; STERN s_ jo BRADDED To

TRIMMING ~~, ee TAKING OFF DECK wing Half-} nished FITTING THE DECK castle, lowing its outer € past the hull line

LINES FOR BULWARKS aie aa H ee ‘ Hull pin the bulwarl ; } <ige to project At intervals

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POPULAR MECHANICS PROFILE OF WELL-DECK BULWARKS 2 CURVE OF DECK OVER HANG __ FOR ~RIMMING I 1 ar ~~ Ht mmenmette STRIP PINNED ’| STRIP TRIMMED AND GLUED j TO CURVE 10 HULL OF HULL DRIVING PINS THROUGH THIN STRIPS WITHOUT SPLITTING FOCSLE RAIL BOTTOM # Post, % HIGH ---~ .| SPINS EQUALLY SPACED) anaes ——— ee | Tl 4 FOCSLE HEAD JOINT OF POOP BULWARKS AND STERN BOARD i PIN — STANCHION JOINT OF FO'C'SLE RAIL BULWARK 4 RAIL, Oe BULWARK NS ~ ~ SMALL BLOCK GLUED . TO BULWARK TOP AND - CARVED TO RAIL SHAPE Note the Detail Showing How to Drive Pins through Strips without Splitting; This Will Be Found Very Useful BANK PIN y OPEN a 2 i RAIL *s , et oe eee WELL-DECK BULWARK —_—_— ¥ °

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POPULAR MECHANICS 853 orking toward the stern, drive in ad- nal pins, bending the bulwark strip to e hull line, but always allowing it to ect slightly, so that it may later be ed, filed and sanded down to fit. n you reach the break of the quarter- where it rises above the main deck, e a long pin down to hold the bottom e bulwark strip in place, then bend top in to follow the hull curve, and, a pin driven diagonally back into the irterdeck structure, bind it in place. e second bulwark strip, above the quar- and poopdeck, requires less bending, is placed in the same way, and pins or brads are then driv- en through the stern bulwark, to CUT DOWN ./” TO MEET STEM BEAK / FLOOR STEM _ TEMPLATE ~~--- KEEL Size Template of the Stem and Detail of How It Is Fitted ive off the inside until 1 1 nN s been reduced at the ne least. will top at process verhang and deck space. | front, high st that go along the sides of the bulwarks must be bent to conform to the curva- are to ture of the forecastle. Cut them to size and length and drop them in a kettle of boiling water tor a half hour, by time they glued and pinned in place. The rails on top of the aft, and the open rails of and torecastle come next. 1 which will be pliable enough to be solid bulw arks the deck Those on well the solid bulwarks are “46 by \% in cut from white pine, and with top corners slightly rounded with sandpaper. The top rail of the stern bulwark is whittled out from a strip 4% in. thick, and the curving rails at the break, where the bulwarks drop from the poop to FO'C'SLE SHAPE OF BEAK FLOOR FITTING BEAK FLOOR

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S54 POPULAR MECHANICS long, heavy pins known as “bank pins.” Cut them 5g in. from the point, lay the tops for future use, and use the point sections for stanchions. Push them threugh the holes drilled in the rail, slip a ing are made from the -in. block between bulwark and rail, and drive the pins down into the bulwark. If the latter shows a tendency to split, take one of the small metal clamps and tighten it on the rail at the point where the pin is penetrating. After the pins are all driven down flush with the rail top, they may be countersunk slightly, and the holes filled ith putty or a prepared crack and crev- he fo’e’sle bulwark rails are made in the same way, except that the corner posts are of wood, % in. square and 4% in. high. Clamp the posts in a vise and carefully small pins down to help the glue hold them in place. Then glue the rails on top and add the pin stanchions. The next step is to build the beak, which, in these old ships, still retains distinct traces of its ancestor, the fighting beak of the Roman galleys. . Using the template on page 853, lay out the stem on a piece of white pine or bass- wood, 46 in. thick, turning the template in such a way that the grain of the wood will run as straight as possible with the thin fore-end. to which the deck of the beak must later be fastened. The st is designed to project slightly under hull, and later the keel will be joined it « ri \ ind continue aft. ilue ¢ in the sten he hull slue and pin the stem to the hull then, with a handsaw, cut the bow strai down from the front end of the foreca to the level of the stem top. Next saw « the beak floor from “e-in. white pine, mark the deck planking in the same 1 ner as for the main decks. Glue the fl in place and you are ready to start build ing up the bul Iwarks. Their lower edg where they join the floor, are beveled an angle of about 30°, so as to give thi an outward flare. Thev can be cut 4-in. white pine, and at the rear end in. is whittled down to a thickness of in., to bend around and join to the hu as shown in the detail sketch. It will necessary to steam them by boiling. half dozen of the small clamps will be too many to hold them as they are be: glued and pinned in place. The figurehead of the lion comes ne» It is carved from 34-in. soft wood. ¢ a strip to the proper length and height lay out the lines shown in the figurehe drawing (actual size) on this page. space under the belly and back of hindlegs is carved out, but the pair legs are not separated. Instead they throug € ] 1 the full width, for greater stre1 SIDE OF HULL JOINT OF BEAK BULWARK & HULL | Right, Full-Size Template for Figurehead of Lion Details of Beak Bulw: and Fo’c’sle Ornamer

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POPULAR MECHANICS ie the figurehead in place on top of rojecting end of the stem and be- the front end of the bulwarks. A stanchion, % in. square and % in. fastens on top the bulwarks and ex- along the lion’s back to form the rd support of the beak rails. e ornamental extensions of the bul- ks up the sides of the forecastle come They are from %-in. stock, carved to fit the curves ofthe hull, and brought finished thickness of % in. side view is shown in the detail, | further dimensions are valueless, since can best be fitted to the hull and beak cut-and-try methods. The rails from ese pieces to the strip above the lion’s k, and the pin stanchions, are added in me wav as those on the other decks. n toa (To Be Continued) False Eyes Make Comic Design This e 7 laise WiRe BOW pair e\ Ss ¢4 bv he t he m- selves are made from b e ma de anyone. T eves two oval pieces ot heavy white board. 114 in. card about long by lin. wide. Soal them in water until pliable and betw then lay een two spoon bowls, 1 a= =.= = — T PAPER PRESSED BETWEEN . SPOONS eight. the paper aint the convex sides like I , lue between them a wire bow Drill a small hole in each pupil pair of glasses on your nose t they cover your eves completely. ‘an see through the holes well enough ibout and the disguise will prove the » represent crossed eyes or 1 1 oF ical, especially if 1) eves are are ol colors. Small, oc Collapsible Footstool Sitting Found Convenient Pullman Berth Wher Small Footstool Convenient on Train ’ Is cur. An easy throw a piece of sl .. into the fur This will flakes

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POPULAR MECHANICS Draining Vapor Lamps a 4-in. length of generator tube that been straightened periectly. The flar ips burning kerosene or gaso- end may be used for the plunger and in I upon clean fuel for the best be fled down to make a snug fit. he Dirty liquid must be removed — eration of the siphon is as follows: ‘carbonizes or clogs the delicate the lamp at an angle on the table and range a pan at a lower level near by. : sert the first tube and let the suction pu —Teaeen @ \\ hang over the pan, always at a lower |e ff “RUBBER STOPPER h the plunger of the lamp alm: RUBBER TUBE --*} and, placing the finger over the open METAL TUBE ai pull the plunger out sharply nearly its ¢ t . tire length. Repeat this two or th: TI brass tubing. —L. B. | jet in the burner. Getting all the gasoline Sling for Transporting Culverts . 4 5S . Single-Handed hown in the drawing, the job is easy. A Moving culverts or tubes made o ut of the lamp by inverting it is almost impossible, but by using a siphon, as siphon can be made as follows: Straighten rugated steel is quite a heavy task for out two old generator tubes and force out man when they are or the asbestos filling with a steel wire. Saw However, an easy method of doing tl off one tube so that it will reach the bot- shown in the drawing. Drive tom edge of the fount by curving it suff- your wagon over the culvert ciently and will projyecta short wav above and straddle it. Lift up the fount. Slightly pinch the lower end the rear end and set a so that a lead shot, dropped in the tube stick or brace under it. from the top, will travel easily down the Next fasten a chain tube, but will ni ‘ome out of the small around the culvert lril 1 hole through the and the rear axle. bottom. and rivet When you let the i piece of pin through the tube, cated. This forms a check valve, as in the detail. Push the tube throug rubber stopper with a notch cut in the side to make an air intake to the fount. When properly adjusted the check valve should nearly touch the bottom of the fount with the cork in place. Then fit about 2 ft. ot rubber tubing to the top of this tube. Make a suction pump from Moving Long Culverts Is No One-Man Job, But This Meth . . ° i . an Easy One a 4-in. length of brass tubing with an-inside diameter just large enough to let culvert down it will be suspended bene the generator tubing slide up and down 1n the wagon as shown in the illustratio1 it. Solder a short piece of the smallertub- chain may then be fastened around ing in oue end and in the other end insert culvert and the coupling pole of the wag:

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How to Make a Sewineg- Basket Taboret By EDWIN M. LOVE combination of a sewing basket 1a taboret results in the easily built, tractive and useful piece of furn: lustrated here. It may be.of hard stained and varnished to match the furnishings, or may be of soft wood | in enamel. the top, glue up two widths of 1 by tock, putting in three hard | dowel pins, 3 in. long. After drying i. circle of 8'4-in. radius, and lay out igon illustrated by stepping around rcumference with dividers set to the Saw out carefully, and smooth ges to dimensions. %M-in. | Glue and nail, fine brads around the top edges, a 1. half-round mold, joined at the cor- cutting the ends to an angle of 60 a margin of \% in. above and below Id as indicated. Che mold in., afterward planing off the corners make a half-octagon, and finishing by moving these corners and sanding applying to the top, it may be foun one piece projects bevond its mate. working it down, slope gradually. While the top stock is drying, make the sides. These are of veneer, cut with the grain of the plies running vertically. s-in. three ply panel outer Make them 554 in. long and 7 in. wide, the joint edges be ing beveled to an angle of 60 [t will be found very 12] handy to cut an angle tem plate of l-in. stock to press agai saw in cutting. With a fine-too and careful guiding, no planing edges will be necessary: but t avoid is used, rounding or ingles out of true. LEG LAYOUT -- LEGS NOTCHED —--~ x PLAN AND ELEVATION Here Is an Attrac- tive and Useful Article That Will Appeal Both to the Housewife and the Amateur Wood rKer

Page 160

POPULAR MECHANICS Make six hardwood corner beads of tri- Prepare a template for the leg layout angular section, as shown, to reinforce the dividing a 4+ by 20-in. rectangle of ¢; corner joints of the box. The two 1-in. board into 1-in. squares, upon the sides make an angle with one another of of which the outline intersections ca located as they are in the d: ing. When a smooth outline rs obtained, cut out, and trace —— ing them together for economy, _ eae >> «six legs on 1 by 6-in. stock, nest —_—— 7 —_—_-»j ~ % we et : (im material, but keeping the eg oreo . , ey a | vertical. They may be cut with a compass saw and smoot! pe with spokeshave, woodrasp SIDES, 6 REQ. sandpaper. Notice that tl notch under the bottom. The legs are centered on -- box sides. Bore and countersin| TOP EDGE - : ’ Y on the inside for No. 10 wo {3 “4 1 r . 47 screws, two holes for each a ~~ lo ‘ . I : ] penny ae keeping them 1% in. below | LAY Sony uN top and above the bottom. Ou CORNER CLEAT TOP CLEAT side, square down guide lines 6 REQ. 6 REQ. 1 the leg faces, and notch the jecting edge of the bottom ] leg in lace and marl Constructional Details for crew posi Drill smal the Sewing-Basket Taboret tl ese down the cente the partition. MATERIAL LIST

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POPULAR MECHANICS life, due to the greater flexing sed on the walls of the casing, harder and increases ency to shimmy. It pays, there- watch the tire pressure closely, it twice a week or oftener. Many have found that the tire mileage increased by carrying pressures steering pounds above that recom- ree a. > the manufacturer of their car. imp one well-known six sures recommended are 30 Ib. for tires and 35 for the rear. It has experience, however, that 38 lb. both front and rear results in easier steering, but in ‘tion in tire wear of from 30 to 50 t, without any appreciable loss of Of course, the increase sure not be carried to ex- Two or three pounds above the ure recommended is enough, and the ner will do well to consult his deal- e, on omtort. must ervice manager about the matter. can give him the results of many owners’ experience, as well as that 1 vn demonstrators Straightening Wire be straight lengths Cut it off in 2-ft. ; e can in per- following drawn out the lengths, chuck one in he hand drill and the other end in vise, as shown in the illustration, ve the wire a of turns, ill straighten it out immediate must bring the wire un- ion while twisting it, and its size, how number se, one nd flexibilitv determine a Method of ghtening Wire with i Drill and a Vise many twists to give it. No. 14 copper bus wire, such as is ¢ sively used in wiring radio sets, cot straightened by giving it five or six t —E, R, Haan, Chicago. Toy Moving-Picture Machine The photo shows a toy moving-p machine with a motor drive. The It was found that *xten ild be vists icture motor Improvised Motor-Drive is taken from an electri and blades being vheel mounted on is ma follows: 4-130 Kodak film, saw as trim the end so tha flange from the discard a cork, 1% in. in diame in. thick and mount it between of ; ] the shaft of t 1 that tt} tile t the spool Phen he tor so the machine. moving-picture m with bench by means of a couple of prevent it from twisting. It essary to fasten the motor, as in any position placed.— Car Charleston, S. C

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POPULAR MECHANICS and pressing the points down into the shingles, the platiorm is prevented from rising, and the sharpened nails at the keep it from slipping down. This mal level platform on the roof and the painter can work freely with both hands.—L. B. Robbins, Harwich, Mass. Preparing Floor Wax Many amateurs who have had trouble in using floor wax seem to think that it possible to use it just as it comes from t] can. This is the cause of all gray sp which are due to uneven work by u lt we. wax that has not been properly treate {/ | 2 ze For best results. floor wax should be re a duced as follows: Remove a small quan rant NAILS) 2 OMe tity from the can, add a little linseed and add turpentine sufficient to reduce t athin paste. This should be done no 1 ter what the wax is used for. A 1 Quickly Made Support for the Paint Pail Allows even job can be done and the work of | Worker to Use Both Hands ishing will be much easier. Roof Platform for Paint Pail ; rchar If you have ever tried to paint the ridge Supercharger for Small Auto boards on the roof, or some point project- Racing cars as well as several of ing above it. you know how difficult it is more expensive European cars are fit to keep vour balance and hold the paint with superchargers, which are device pail at the same time. A platform forthe put the air supply of the car under pail, that can be placed anywhere on the | pressure instead of depending on the \ 1 will keep the pail level, can be um created in the cylinder, as is the ‘ut out two with the ordinary auto carburetor. that the pressure system gives a decided in in speed and | well as greate FUNNEL economy. : ‘ supercharg FLEXIBLE TUBING, : too col iplica expensive | a pressure points a1 | ndthen Eee ie ; consists of a | downward. Drive funnel, fitted c’l two or three nails in Increased Speed and Power, and More Mileage per hehind the fat Gallon Are the Results of This Installation : to the bottom edge catch the ait of the sides near the wide end and file the connected to the air inlet of the carbu heads to a point. These nails should slant by a piece of flexible tubing such as somewhat toward the rear. By pushing on exhaust heaters. This arrangement the pointed metal strips under the shingles so brings warm air into the carburet'

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All Shop Notes published in 1925, in book form—Fifty Cents—irom our Book Department Use Your Outboard Motor for Power By LAWRENCE B. ROBBINS \ outboard boat motor is seldom used 4 or more than three or four months vear, but the man who likes to tink- build things during the winter days itilize it as a serviceable power plant s basement or barn shop. It will n perfectly in driving small ma- such as drills, bandsaws, bench etc., and if properly installed and ed can do the motor no harm. The ccessories needed will be an automo- iator and fan and some garden hose;. also a bit of blacksmith work and simple pipe fitting. This latter may be hired done, but the handy man should be well able to prepare every part himself. A solid wall should be selected upon which to build the motor support. It hould be at right angles to the counter- shaft or machine to be operated Cut out two wide planks, about 1 ft. taller than the height of the radiator and 1 ft. wide Slightly taper them and spike or bolt them to the wall and floor with the small ) ee f the Outboard-Motor Plant Assembled and Run- Feed Grinder; Many Uses for the Handy Unit Can Be Found

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POPULAR Place them at least 2 ft. apart. ma and vertical, and then spike solid Let dow n. parallel planks horizontally across the front. ROD BOLT TO FACE PLANK NIPPLE TAPPED FOR OUTLET HOSE ~ NIPPLE IN PLUG FOR INTAKE HOSE ~s. -WATER OUTLET '

4

INTAKE PULLEY IN - PLACE OF PROPELLER 4 Side Elevation, Showing the Various Construction Details; Is Very Little Work Necessary pli ends o uppermost ve the he motor can be clamped terference. If wide planks ble, smaller ones can be used vig? which case corner In and Cl position 1en plumb the verti- te as indicat ted and flattene: ao iron can the propeller at diameter solid-iron pulley I articular motor being h the conform wit enn te and cut a new kevyway, or it MEC \ pinion pulls out. ion must be fitted to the pulley an FAN AND PULLEY DETAIL __ MOTOR . { BRACING lay be necessary to rebore the HANICS mean that the entire propelle: In this case, a new complete installation made either case, the work will ni found difficult. Then drill pulley hub to match the hok the latter t arrange the fan and bolt as shown. Twist vanes to blow air away from motor when the pulley is rey ing in its proper direction. or t Plug the inlet and outlet | no leaks of the radiator so occur and then drill and tap t! pipes in suitable places for ¢ %4-in. nipples. Spike blocks ti floor in front of the fan mount the radiator on them lag bolts. Then make a long rod, to secure the top of the ator to the face planks in a manner. Thehoseconnectio1 There then made to the two nippl ae ows: Tay the radiator as fol water-intake opening at the botto hort pie +] + tne same shaft housing and insert a s pipe or a nipple, and do he cylinder wate at tl Then clamp a hose from the inlet t Oo ~ outlet openin bottom of the radiator and from the let to the top of the radiator. TI circulatory syste ‘m. The wr pletes the ing fan bl nrevents heated as it engine, pipes Belt up th » I Lilie - . ] Sia al aoors and windows open, 1 noticeable. of the not be will account weat by all , on should, means, be carr ther 1° his can be easily done by the placin tin funnel over the muffler openin

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POPULAR MECHANICS ng it to a line of common rain in diameter, and leading it out- rough a window or the chimney. ib for the Shop-Sweeping Brush the minor annoyances of ma- yp life is the way steel cuttings the brush when the floor is swept. a piece of wire is often used to e brush, but this takes so much it we decided to make upa regular the purpose, and this is shown iccompanying drawing. Two end- sharpened at one end, are attached brush loosely with screws. These es hold a rod, drilled with a row to take short pointed wires, which teeth of the comb. The pieces be securely soldered or welded to- Have the comb laid back on the vhen the brush is in use. When ttings have been swept into a pile - removal, the brush is cleaned by it over to allow the comb to fall o that the pointed ends can be dug loor and the brush rocked back and causes the comb to pass Attached to Brush Cleans It of Metal Cuttings gh the brush and clean it thoroughly sweepings that may have stuck in it. try Moore, Montreal, Can. Handy Drill-Press Accessory ———- “ Adjustable Stand near Drill Press for Holding Long Work Reduces Labor Che adjustable steel horse shown in photo has proved a iluable accessory to the drill press in a Denver steel shop, where it was origin ated to hold up the back end of long work being drilled ng aries Two sections of 4 by 1!4-in. steel bar, about 6 ft. long, are bent to form the ends ot the frame, and two piece s of tl terial, 16 in. long, are riy end of these, to serve sections of the bar are also ri wise to the legs. support the roller feeder with numerous holes be adjusted to any neig simply moving two cotter keys u —TJos. ea oule Denver. Co] How You Can Guide Your Tractor with a Door Spring When plowing wi one front wheel guiding is necessary. ing wheel front wheel bump on the surt return to the str remedy this, ring attached, was buckled of the wheel and a screen-d attached to a point on the frame directly opposite to this ring One end of the pring is snapped to the ring time the wheel is thrown anda either right or to the left, the spring return

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POPULAR MECHANICS Increasing Usefulness of a Saw The saw shown in the drawing should be used beiore its merit can be fully appre- ciated. Jt is a crosscut saw of the usual Scale Etched on Saw Blade and Block, Making a Square, Increase Utility of a Saw Safety Rules for Working around Ammonia Pipes hen opening pipe joint peen carriea, care to open the joint wide instantly. ger in such pipes in quantities to becom W here ali- should be sufficient e dangerous when lib- erated in a room suddenly: Flanged should be and opened by means of a thin wedge or jack and, if any fumes are detecte: joint should be closed immediately loosened very sli they are drawn off or it may be left s ly open so that the fumes may pa: gradually. It is bolts of a flange joint more than b enough to separate the joint in case t might be pressure within the pipe, w would cause disaster if liberated sudden! Screw joints should have the union s]! ly loosened and the joint broken loos fore the union nut is entirely unscrewe A towel saturated with vinegar hel the face should be used when looseni: best not to loose: working with ammonia-pipe joints « cially in confined rooms Can Saves Varnish A varnish can which preserves the tents, is used in a vehicle factory. It been found wasteful to pour the vari into small cans as it rapidly deteri if not used up within a short time as > cans must be carried arout fr the varnish was shown in the illust: Ot varnish and 1 metal. It is round it When the ishis required. enough 4] tow 1 ie COwWt!. cork Is replace the can POSITION OF CAN WHE?! URING LIQUID and placed uj r! o that cover ished, the « ‘-k is removed to all unused varnish to run back into the

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POPULAR M ng Lengths of e Wire Rolls on Attached to the ear Wheel of a Tractor, Is Jacked Up for This Purpose Tractor Used to Wind Up Fence Wire into built the small farm tractor descvibed he August, 1917, issue of Pepular Me and been of considerable Last year | an idea about a device on the or for winding up barbed wire. Wind- it by hand is a mean job, but with the this attachment the work can be a short time. To each spoke of of the rear wheels a short length of rod is clamped to extend outward as nin the drawing. In use, the trac- at one end of the fence and is The wire is loosened from the s and one end is attached to one of winding ved, has me for several years. neeived oT Lt in is set ked up. + peo P©s>- The wheel is then re- which winds the wire around the ¥ ou can length a halt long in this When the is completed, up with short ot nd 2 of bout eths wire, sen a few pegs to- the center of slip them which permit you to ve the roll of When using 1, 1 CCl, Method of Testing Air £ } ECHANICS the tl wire with a 5 or 6-ft. the length of iron pipe tractor for is purpose, guide as indicated and keep one hand on the clutch at all times so that if the wire gets caught the can stopped at once before the wire breaks or other damage 1 nider, Onaga, Kans or tangled winding be done. -Luther Stros- S Saving Time in Testing Air The time required to test the air on rail- way cars has been shortened by a method devised by an employe of a western road. He attached a short length of hose to the tester, valve mounted usual exhaust as on the triple- and connected the other end of the hose to the retainer pipe. By the use of a small port, petcock between the hose and air both retainer ma vauge cvlinder and be \ tested without necessity ylinder and Retainer ailway Car

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POPULAR Two-Man Jobs Are Speeded Up by Swiveling Work Holder Many shop operations could be finished more easily and quickly with the help of Swinging Work Holder Facilitates Handling Large Quantity of Parts in the It is used in connection with a job of brazing nuts R metal and retapping the hole are the next the e holder 1s holder similar to the one shown illustration. on the ends of flat- spring hooks emoving the surplus operations. These are done on Th same bench at the opposite side used to facilitate the passing of the work from one operator to the other. The cen- with a ter board is drilled depth of about 6 in., the drilled through near -in. hole to a to ti ; this piece being ike a piece Oo! steel same di imetetr he top to take a rail lich is driven tightly and then turned \ collar with a t j made of '%4-in. rod, w into the swivel post up slightly at each end set- SCTeEW\ is fitted to the post and. when as- sembled, it rests on MECHANICS when finished on the part of the rail at side of the bench; the first being pla at the extreme end, as shown in the phot so that by the time this side of the rai full, the end pieces are cool enough to handled by the operator on the oppo side. Both operations consume about same time; by the time one side of rail is filled, the other is empty and all t second operator need do to get anot! batch is to swing the holder around a ] turn when the rail pI sented to the first operator ready for t [It has been found that by worki: this way there is no possibility of mixi: empty is again ing. up the work as often happened befor When the holder is not required, the p: is lowered and the rail laid parallel w the center board out of the way. Acid Test for Oil The presence of acid in lubricating o detrimental test blue and the following sit is 1) 9% ¢ recommended. the ] Oll, color changes to red, there is acid preset to discover it is litmus paper in and , soaked in Che litmus paper should be water betore the test, for if the water to | acid absorbed by the paper and the oil neutral contains considera pens ve alkaline, it will neutralize condition when it re i. ce rit aCid, show a Winter Shelter for Pump and Engine Phe farmer who finds difficulty in kee; his and pump will ing pasture engine pt tected against severe cold, find idea illustrated in the The shed used to protect sists of a framework inclosed and ro: with stalks, photo serviceal the pump « corn bound togethet bundles and held a couple of washers placed on top of the tect it from wear as the holder is turned. The meth- of using the holder as fol- lows : T h e oper- engaged in board, to pro od 1S ator place with a both inside { outside. With tl wind thus kept o the inferior will quite warm Wi the engine is rut ning, thus for more operation.—Dale maki efficie: the nuts each piece brazing hangs Corn-Stalk Shed Shelters Pasture Pump and Engine during Coli Weather Van Horn, Walt: Nebraska.

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How to Build the Form Work for a Concrete Cistern By ROY M. SINGER RE are many localities where it is ecessary to store water. Generally rangement is used whereby rain falling on the roof of a house is let cistern and pumped from the cis- it is needed. The cistern may be wood, steel. or concrete. = meeting either of with a favor because of the fact rete cisterns are deal of materials are to be had in prac- every locality and because nearly me can build them. here deep cisterns are built, the form because such cisterns are ult with cisterns, ] wide mouths. For however, the situation is different. It is easy enough to erect the forms for a shallow cistern. but taking out the form work is quite a different matter The sketches shown here illustrate a type of form work designed especially for shal mouths, and it is especially adapted to withdrawal a narrow space. low cisterns with narrow from In building a cistern of this type, bottom and walls are put in place fi then the form work for the top is set, as shown in the sketches. The form work consists of a central post to which a bar- rel head is attached by hooks: cistern wall spanning the space between the and the barrel head are set 2 by 6-in. pieces cut

VERTICAL ~

A BARREL HEAD-- METHOD OF HOLDING BARREL HEAD TO VERTICAL SECTION ” HINGE fs S BARREL HEAD, VERTICAL a Ss pb ce _ —

i “STOP FORMS \CISTERN WALL , BARREL HEAD CISTERN TOP { JOINT HINGE td! TAPERED 2x6" (|! REINFORCING = | f..| RODS . f ) CISTERN VERTICAL ty) WALL SECTION THROUGH CISTERN TOP. > Ty A ~<REINFORCING ea RODS | (FILLED IN IF “DESIRED DETAIL AT JUNCTION

TOP VIEW ag “ie

OF TOP AND WALL

Method of Building Top Forms for Shal- low Cistern Where One-Piece Planks Cannot Be Used

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POPULAR MECHANICS tapered to fill the circle. These pieces are mouth of the cistern is wider than the b hinged in the center and it is the hinges rel) and removed from the cistern. permit the easy withdrawal of the post then withdrawn, and the job is do: fr rm om the cistern After the form Where a shallow cistern is built it wou work has been set up and the top of the be impossible to withdraw the forms f1 «WIRE HOOK | woe ro PULL TOWARDS CENTER |i |! ie i \ HOOKED WITH WIRE H i PULLED OUT ' t — j _— = cistern placed, + eg the cistern u as shown in the ‘ ’ or , less an excepti photographs, sufh- . Rahs _ ally wide mout cient time should be : were provided, bec: allowed to elapse in order : ate an a the ends of the top-f to permit the thorough dry- lg boards, when dropped, \ ing of the top of the cistern strike the bottom of the The form should be left in place for at tern before the upper ends could be pa least ten days. through the top opening. This met! When it becomes time to remove the of hinging overcomes the difficult) forms, a wire is attached to the barrel head and the hooks holding the barrel head to the post are loosened. The bar- rel head is then allowed to slide down on Time-Saving Device Administers Capsules to Poultry the post until it falls free of the tapered Every poultry raiser finds it pieces. It will be found that the 2 by 6-in. at times to treat his stock for hs wi *k to the top of the cistern, usual remedy is nicotine sul 1 the fact that they are held in place 11 the notch at the cistern wall and by the adhesion between the underside of the top of the cistern and the wood form. his adhesion may be overcome by plac- ing tar paper upon the form before the top is poured; thus there will be a laver of tar paper between the form and the top ot the cistern and the form will not stick. Now attach a wire to one of the tapered pieces so that it can fall into the cistern, then work it out of the notch in the cis- gling it back and forth. It tern wall by jig may then be pu 11 ! ed toward the opening. "he manner of removing it is best illus- trated by the detail drawing. It will be seen here, that as the piece is pulled to- ward the opening, it collapses at the joint, and the wire may then be pushed farther along until the joint is reached, where- upon the form may be removed. After all the top forms have been taken out, the arre P . . : ‘os ; ‘ Improvised Injector for Administering Capsules barrel ma} be pulled up (be sure that the Poultry Does the Work in a Short Time

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POPULAR MECHANICS ules and the usual method of admin- ig the capsule is to insert it into the beak and then work it down with ngers. Frequently the operation is ‘cessful and the bird ejects the cap- be picked up by another already and then the result is at least one | fo avoid such accidents and the operation quick and easy, a ia poultryman has improvised an with which a hundred or more treated in the same time as The instrument ehtly curved hard-rubber tube, or about 5 in. long. Cut into the of the tube so it will fit over a No. 2 ule. A wire injector fitting the top of hole for the capsule is placed in the The top of the wire is attached to tton, while a spring is provided around vire. Press the button to move the ector and release the capsule. Release e pressure on the button and the spring sind the wire will pull the injector back use the instrument the place, the tube is insert- ent, av be 1e old method. ) place. To ysule is put in through the open beak of the bird, the ‘ctor is pressed out and the tube is then The operation requires about seconds, while, without the device, it takes five minutes.—Geo. B. vers, San Diego, Calif. hdrawn. letimes Side Hitch for Motor Truck here are many other than just hauling bs that the truck pertorm when equipped with devices adapting it to these bs. The drawing and photo show how a de hitch can be attached to a truck. It used, without damage to the truck, that do not require heavy rain, such as stretching fence posts prevents a will in be jobs too wires here line of direct from ete rear end of the truck a bank, ditch or openings ; pulling pull- w along gulley, en filling these a road to trim off the erc.. rhe side of the graded required and their the drawing. The ng bar is made of a piece of 1% by 3- ichine steel, forged with the nner end around a U-bolt. The bolt the side of two pieces s are shown in eve at the nuts on the angle bend its given the inner pull truck \ right- Irame oft S69 ing bar to allow the front wheel to clear both the bar and the nects it to the front which the qq )) EYEBOLT chain, con- end of truck x3 STEEL DETAIL OF ATTACHMENT Pulls Handy Hook Attached to Side of Farm Tractor Light Implements dash allows to the the evebolt frame. The chain, attached and means of adjustment for height such as the tool ing pulled, or as the work may require. It the folded and hooked in a vertical position when not in McVicker. North Bend, Nebr. bar by allows bar to be also use.—G. G. Eliminating Air Leaks in Stone Foundations It is rather difficult to make a air-tight job at the top of stone really founda- tions. is considerable that prevent The heat loss caused by such leak- age and causes cold floors in spite of all ; 2°x10" SPIKED TO JOISTS SUBFLOOR /PLATE FOR STUDDING — > se is done to it. A good method this shown in of preventing trouble is the accompanying wer erks illustration. \ 2- board is nailed to the plate, as in- AIR SEAL dicated, the top of tion hav- cut back ) ‘ ° Wh Lvs permit this. er SET IN GROUT AND NAILED TO PLATE UNDER JOISTS ie founda been The iling board is set grout, and after is in place one S iould be

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S70 A Serviceable Homemade Grinder As can be seen, the grinder and buffer hown in the drawing is built up almost entirely from pipe fittings and POPULAR MECHANICS difficulty usually encountered when doi: such a job. Both ends were cut squ and one end was fastened to the old be The roll of new belting was placed on t ol | Ford floor flange and a tee, screwed to the flange with a form the reamed out to connecting rods. \ short nipple, base. The tee is take a short length of pipe and setscrews are used to hold the pipe C in place, on which four connecting rods are fitted to hold the grinder arbor and the driveshaft. The of the connecting lower surfaces ] rods are bearing screwed up tight on the pipe C, to make the arbor and driveshaft parallel. The are fitted with grease shaft is upper bearings cups. The provided with tight and pullevs and also a drive pulley. Another pulley is fitted on the arbor in line with the drive pulley, and also two collars hav- ing an overhang to inclose felt dust wash- ers, which are placed as shown in the de- tail. The arbor shaft I is turned down for the grinder and buffer, and the ends are threaded for nuts with which the wheels are held on the shaft securely —Geo. H. Cappel, Wilmer, Ala. drive- loose Installing New Belt in Factory In a factory where I was doing a small job; a long and heavy leather belt, about 18 in. wide, was installed. The method used to get the belt in position was novel to me as it most being removed of the DRIVE SHAFT --. DRIVE PULLEY ---, 7--- CONNECTING RODS», ,- COLLAR . ! T FLOOR FLANGE _ On HOLE I) Old Auto Connect Rods, a Few Pipe Fittin; and Two Shafts Make Good Grinder and Buff for the Small Works! of the old belt so that it unwind when the latter was turn The shafting and pulley were turned o slowly, allowing the new belt to run « W he the new belt was run out, the clamps w put on, the rods tightened and the old | cut off, leaving the new one in place the pulley on top of the old belt. g a perfectly tight joint, ready for the joi I fasteners.—] ». Noble, Toronto. Can Metal Float for Special Fuels Special fuels for automobile use are ft quently compounded with benzol. dissol the shellac fr the cork float the carburet: and the bi comes benzol cork saturate A clogged and a constant dripping carbure or are evicence this conditi . Loss of gasoli! WIRE > is expensive a possib To prevent this troubl should I also a source of fire. metal float be used in the car

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POPULAR MECHANICS The method of making this is shown in the drawing. used should thick: and ypper be ap- 64 1M. this is formed working from The and s held by overlapping and ‘ularly vent rod, around the circle. brought together ethem. The hinge is also | to the float. After com- of the float it is a simple to bend the wire until the ches the proper level. Jig for Center-Drilling Keyways mac! , line parts, like gears, sleeves, held to means of setscrews bearing on Lightening the Task of Handling a Heavy Air Hammer by Burlap Padding and Heavy Rubber Tube ccc... BIL by Absorbing the Shock of an Air Hammer itself. In such cases it is impera- hat the tapped hole is central with part of the locking We use a very simple jig Holding a heavy air hammer, driven by 10-lb. pressure, and cutting rivets with it all day is no light task for three men, yet there method of making the work it would be with the naked hammer, as turned out by the manufac- turer. yway, else is lost: lis Work. ] body, al or It consists of three parts; bushing and a The is made of 34-in. round stock, bent the bushing is % in. in diam and is sawed up the center and spread to form a V-shape. is a screw. easier than hown; To soften the jar and rub of the machine, it is wrapped thickly in burlap, while the jar the butt, against the operator's body, is lessened by ere? The jig is slid in- he keyway and the bushing is pushed to draw a 6-in. section of air hose, such as is used Booy [+ DRILL the body up in in coupling railroad cars, which is held Nj 1, BUSHING TS _ TIGHTENING wearisome of down the keyway_ by two small bolts through the hose and 4 mY firmly;thenthe the butt of the Jos. C tight- Denver, Colo. Only one-size hole be drilled, course, but this al- hammer.-— Coyle, screw is ened. Pulley Guard Saves Hands can of To prevent work- ers from as is getting ways central, it can be enlarged with another drill to the size required. We hold such work the vise and square it up with the side he jig. ake 8 e with galvanized tacks. he undersid } the OZ. upper canvas ] side W nt it while damp tel prooling. it on After paint- and stretch a e and allowing it to dry, water and then This insures good ith clothing and hands between a pulley and the belt, the novel guard shown in the illustration has been practical. found It good precaution es pecially if the belts be thrown is a have to off the frequently belt or is used as a safety device and throws itself oft the machine is jammed. ieu, Chicago, Il. Auguste

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POPULAR MECHANICS Broken Water Jacket Repaired using zinc chloride dissolved in distil]. without Welding water as a flux. Usea hot iron and mal! sure that the entire surface of the “V With the coming of an unexpected cold tinned before filling it up flush with t! ‘nap, many motorists discover a cracked surface of the jacket. Scrape away 1 10-24 BRASS SCREWS surplus solder, ¢ HEARED OFF AND FILED —~~ . ; ite: os FLUSH WITH SURFACE ales g smooth and enamel, a you will have a per: nent and invisible rep job. If welded, eit! electrically or with acet lene, the finished SCREWS . ie, the finished would be lumpy. A ¥ , \ to repair an aluminu WATER JACKET crankcase whe na rod . Ss gone through it, if method can also be u Fig. CLAMP MADE ; wt OF 1X13 STOCK ff -<%* i can recover the piec« In the case of aluminu: make the screws from piece of aluminum and finish the job wit] rood grade of aluminu solder. ; “CHANNEL __) } FILLED Proper Application of Baseboards Cracked Water Jacket. on Automobile Repaired by Simple Method Using Defects in plaster 11 Screws and Solder are frequent, and whe water jacket This usually means a new the plaster has been “dubbed off” a f block or an acetvlene weld, a costly job inches above the floor, the carpenter in either case. However, any external to adopt some means of holding the ba break can be permanently repaired by the board straight. A good method is sho following method. Fig. 1 shows a cylinder in the illustration \ 16-penny spike block with a section of the jacket broken driven into t! out entirely. Fig. 2 shows the piece re [a | 2-in. plate stored and held in place with a speciall, ry Wha which the stud made, strong clamp. Around the entire . dings are crack, drill and tap holes about % in. apart |” o that tl for 10-24 screws. Next tin a quantity of / i head is flu 10-24 brass screws and screw them in so op mt I Hy Wa ape with the su they will be flush with the inside of the face of tl water jacket. Tinning the threads of the yt i) plaster, screws will prevent the possibility of a y lee * shown at tl leak around the threads. Chisel off all the Wy) WM \ right in tl screws flush with the surface and remove LSP drawing. Ti the clamp. Now make a fairly deep V- Pond) yi ‘ baseboard c channel with a diamond chisel along the y, Wh! = NI then be _ naile entire line of the crack. If your motor Z Z on, care bei! has a removable cylinder block, place it in al taken not

an oven or over a slow fire until oure lead a za ~«6C drive the spi! just melts, or apply the flame of a blow- Zz’ in any farthe torch evenly around the casting until the LARGE NAIL! The incorre metal sizzles under a wet finger. Then fill method is shown at the left for compa up the V-groove with half-and-half solder, son—H. H. Siegele, Emporia, Kans.

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You Can Do Hammered-Copper Work By DICK HUTCHINSON RE are few amateur mechanics have not at one time or another it a pretty piece of hammered-cop- rk, and wished that they could te it. Not that the thing looked but that it was apparent that there e some “tricks of the trade” that were y to know before tackling the job. he purpose of this article, which is f several, to teach the amateur » wield the ball-peen hammer in the effective manner. Of course, the of sheet copper into any de- t ot ering hape requires skill, and this de- diligent practice and effort, but the fundamental operations are really enough. le it is the general impression that assortment of expensive tools is ed for this kind of work, such is not e. The following tools will pretty requirements for rdinary work, and might as well be \ small anvil or a block ughly cover the red at once: Many Attractive Articles of Hammered Cop- per Can Be Produced by the Amateur with a Little Practicé and Skill of steel with a smooth and true surface, an 8-oz. ball-peen hammer, a small bench vise, a pair of tin snips, a good cold chisel, an assortment of punches (nail sets are best and cheapest) which can be ground to suit the of small files, hand, an assortment 10 cents’ sulphur, a small bottle of transparent lac- work at worth of liver oi quer, a good camel’s-hair brush and a few sheets of jewelers’ emery or polishing pa- per from a supply house. Before beginning work, lay a sheet of the emery paper over several thicknesses of blotting paper, emery side up, and pri 1 ceed to polish both faces of the ball-peen 1ammer by rubbing back and forth ove the emery. The blotters afford a cushio for the emery paper, and make a bette A good sur face is necessary, since the smallest scratcl will the surface on the hammer face. on the faces show on finished piece of work. The first operation to be descr the shaping of termed cupping. ota copper bow. oT The general i I have found, is lj ] mmerne 1 he 11t le nammering over the outside. the case, as will be seen i1 Obtain a of 16 piece and from it cut Hold the dis copper, diameter = and place it on the with the edge farthest you slightly raised. hammering, with the end of the hammer, about third of the way in from the With the hammer drive edge. each blow the 1 etal

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S74 POPULAR 1 i toward the edge. Go completely around the disk in this manner, hammering over a strip about % in. wide. Starting inside the first strip ham- SS. a - mered, go around “nn the disk again in the same manner, and then, laying the disk flat on the anvil, circle around the inside until the center has all been hammered. Now tip the disk up on edge and hammer the part outside the first strip and up to the edge, this time driving the metal to- ward the center. Care must be taken not to strike the very outside edge, as this will expand the top of the bowl and make it lopsided. The bowl should now be placed over a fire and heated to a cherry-red, then im- mediately plunged into a pail of cold wa- ter. This anneals the metal, which be- comes hard and brittle under the hammer. The piece is now ready for the second hammering, which is done in exactly the same way as before. Repeat the hammer- ing several times, or until the bowl is about 1 in. deep. The piece must be an- nealed between each hammering. The bowl can be trued by placing it over-a ball of the correct size, and hammering it very lightly on the outside. When the edge has been trued by means of a file the bowl is ready for coloring. MECHANICS The Type of Hammer Used, and the Method of Starting the Cup- ping of the Copper Disk Dissolve about 4 oz. of the liver of phur in a quart of water, and, after ck ing the metal thoroughly with soap water, immerse the bowl in the solution and allow it to rer \ until the desired color is attai then remove, wash under run water and allow it to dry. solution will produce colors ning from a reddish-brown to deep blue, depending on the the article is left immersed. Bur nish the high lights (the ra portions) with a piece of jewelers’ emery paper, polish \ a piece of clean, soft rag: the _ with the camel’s-hair brush, spread a thin coat of lacquer ove: ‘a the entire surface, and the bow! f is completed. The ash trays shown in the accompanying photos are duced by this method, and a little experiment and practice will en able the amateur to turn out man) original designs along this li: The beginner must not be dis couraged if his first attempt does not look as good as the work the professional. In this wor! as in all where manual skill is necessar: patience and perseverance are essent More elaborate pieces’will be described subsequent articles. ~ yt. 4 Say) BD Bumpers for Bottles For several years I have been anno by the occasional breakage of stain, s! lac and acid bottles when handled by t boys in the shop. I have now solved the problem by cutting sections of old inner tubes to fit the bottles. Some of the larger bottles often had the bottoms cracked by being dropped into the cases or by being set down with force. They are now fitted with rubber pads, the same size too great shape as the bottom of the bottle cemented on Lihue, Kauai, T. H. these are shellacked or S. Peterson

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eht-Proof Door for Photographers or that really shuts out the light ne room to another is by photographers, laboratory s and others engaged in work daylight is not desired. Most excluding doors depend upon in- king systems that shut one door the other is opened, or simplicity, always ne shown in the drawing will be d highly satisfactory. Any man handy tools can build it. lt is of the revolving type and is made rranging light-excluding material on me built on two wheels. Its con- Get two light n wheels of the same diameter, and rd wheel slightly larger, so that one he smaller wheels will just turn clear le of it. Arrange the door opening it it is 1 in. wider than the diameter he smaller wheel plus twice the thick- of the rim of the larger wheel. It is est to run it from floor to ceiling. If a ceiling will have to built above the coor to shut out the light from the top. Remove the spokes and saw the large el in four equal parts. Nail one sec- to the door jamb at the top and the om on each side of the door and cover nside surface with light wallboard. tion is as follows: POPULAR MECHANICS 875 If the latter does not conform to the curve, it will be necessary to insert two or three upright strips vertically, mortising Yl? GOV =. lL casenipsitiegli ie BOLT _ A TOP WHEEL [LL _ PARTITION, tI 20 "| lJ {SECTION OF / UY U * WHEEL RIM >--=--= WALL BOARD WALL BOARD BOTTOM WHEEL Excluding Light Effectively from a Photoera~her's Dark Room by Using a Revolving Door, Which Is Pivoted on Wagon Wheels them into the concave surface of the rims. When covered, these walls will be at right angles to the wall of the room and some what concave. Start the door by pivoting one wheel to the ceiling with a heavy lag bolt and the other to the floor. They must be centered exactly between the side walls so that they will turn with equal clearance between the walls. Connect them with wooden uprights, 1 ft. apart and mor tised into the rims. One upright is left out.to provide the door opening. When the frame is completed and revolves even- ly, cover it with wallboard, letting the edges come as close to the ceiling and the floor as practicable. Saw out the section of the rim, between the door-opening up rights, from the bottom wheel and remove half of the spokes. Cover the edges of the revolving door with felt weather strip. A strip of this, run vertically on each side of the door opening in the revolving sec tion, will also help exclude the light as the door revolves. The door is operated bs turning the cylinder until the opening shows, then step in and push the doo around. Painting the interior or the side walls and the revolving section black will also help to eliminate the light.

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Pay Say 876 POPULAR Attaching Packer to Tractor When Plowing When plowing the stubble ground for fall wheat, time can be saved by attaching the packer behind the plow as shown 1 in the photo Usu- MECHANICS packers can be attached. The whole at tachment may be constructed at h with a few simple tools. Glue for Cardboard When giuing cardboard, attention be given to a condition of flexibility, \ me ee ~,* _ ee “Oy, > Ss, Saving Time When Plowing Stubble Ground for Fall Wheat by Attaching the Packer behind the Plow, Both Being Drawn by a Tractor ally a side draft is caused by hitching an- other implement to the side of the trac- tor, especially with a two-plow outfit. However, with a three-plow outfit, or a larger one, the side draft may be largely equalized by running the tractor closer to the furrow, or even in the furrow. The two right wheels may be operated in the furrow and the plow hitch set over so that the proper draft line is obtained. A tim- ber of 2 by 8-in. oak is attached rigidly to the frame or drawbar of the tractor, and is allowed to extend over to the plowed side some 5 or 6 ft. outside of the drive- wheel. The outer end is attached to a point near the front of the tractor frame with a chain, or cable, so that the draft will not come on the attaching bolts at the rear. The packer is equipped with an extension tongue, and it is better to have a front truck. This extension tongue allows the packer to follow behind the plow and to one side. Various holes in the draft tim- ber will allow the hitch of the packer to be made so that it will not interfere with the plow when turning corners. The greatest draft is needed for the plow, and thus, to equalize the side draft, the plow has to be hitched over to the left of the center much less than the packer is hitched to the right. The more plows the tractor operates, the farther over the timber draft bar should extend, and thus the more is desirable in this work. To any quan- tity of flake glue add sufficient water t soak up the glue well, pour off some oi the water and add a small quantity of tur pentine. Then add 2 parts of starch pow der to each part of flake glue by weight mix the whole to a thick mass and allow it to cool before using. Piling Round Bar Stock Many serious accidents have occurr: by piling round shafting carelessly. usual practice lay sticks betws each tier and \ the outside len to prevent rol The wedges « become loose | removing a le! of shaft and the whole pil start rolling. system of shown in the accompanying illustr will prevent the heaviest shafting rolling and is simple and cheap. © pieces of flat stock are bent as show! used between successive tiers, thre four for each tier, depending on the le! The piles are arranged according to and may be safely run up very high

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Embossing Wood Is Simple Operation By HAROLD JACKSON 4h accompanying illustrations show six-penny nail should be used. On coarser, | to make and use a simple little a sixteen or twenty-penny spike is best. th which you can emboss very Cut the point off the nail and file two ul and attractive designs on furni- grooves in the end of the nail at right u are making or on any woodwork angles to each other. Use a three-cor- u may happen to be doing. A de- nered saw file to make these grooves. This border of some kind worked out will make four points on the nail as shown his tool will make your work look _ in the insert. more finished and The desired design is lightly drawn on give it a profes- the work witha pencil. Be sure that your sional appear- pattern outline is perfectly straight and ance. Phon-_ correct before you start to emboss. The ograph doors, tool is used as shown. It is struck rather hard with a hammer which sends the four points down into the surface of the wood. Work up to the pencil lines, being careful not to get outside the pattern outline. The correctness of the outline is very im- portant. Work over the entire surface within the pattern outline DOOR- \\ CASING — \ DESIGN - : ENLARGED VIEW OF NAIL END SHOWING FILED NOTCHES Hi ii) | Tool Made Nail Helps to Im- Appearance of Homemade Furniture tance, if left plain, are look rather bare and ished, but if embossed ome appropriate de- ill be greatly improved. ’ cabinets, occasional tops, ete., look better if ted a little in some wav. tool is made from a wire The size of the nail to use ds upon the nature of the to be done; for rather fine as on radio cabinets, a TABLE TOP =) “I N

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POPULAR MECHANICS

Mirror Helps Do Dado Work In a wood ing plant at W Nebr.., one little practice will - is der muscles

teach a great deal device has bee:

more than a whole Shop Worker Reduces Fatigue and Saves Time by use for three Using Mirror behind Dado Machine and all wil i a Vvno lot of printed in- structions. The ‘tool is really an adapta- worked with it have found it satisfa tion of the “ground” too! used by wood -Dale R. Van Horn, Walton, Nebr carvers, \\ e wood carving demands ™ a lot of practice and skill, really good ‘ ia ! “gt : Extension Handle on Tap work can be done with this simple method After tapping a hole, it usually considerable time to screw the tay and the worker is likely to do this in and become more or less careless vithout any previous e::perience. Handy Milk-‘sot:ie Carrier \ milk-bottle carries for barn or emer- may result in a broken tap. To spe gency use can be made trom a old bar the removal and at the same time rel head and me ti ‘ans. Cleat the the danger of breaking > barrel head that it forms a solid disk. off the tap, thread a 3- he Then turn it over, with the cleats under in. length of %-in. neath, nail a barrel hoop around the rim rod. Knurl it LE ALLIL IO Midd yut three-fourths of a hoop from if possible al- Cut in half as though this is be conveniently not necessary, r the trav to a and screw it should be intothetap.as lk bottles to shown. \fter ‘ay will ac- the hole has been tapped, T I unscrew the extension

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POPULAR MECHANICS k Cleaner from Hacksaw Blades cleaning the face of brick or remov- int and plaster, an excellent tool made from a dozen or more old blades, mounted so that they will ed about 4 in. apart, and provided indles, as shown in the drawing. | the blades together, washers are between the ends and long threaded ith a nut at each end, are used to hem into a solid bundle. The are made up of equal lengths of d, with the ends flattened, drilled nt to the shape shown. Any brick idily be cleaned on the face surface with this tool so that it has the appearance of being new when set into a finished wall. To hold the brick, four blocks of wood are nailed to a bench and spaced to ac- ™ a ee CLAMP Clamping a French Curve to a Triangle Makes It Easy to Handle Clamp on Triangle Holds French Curve Many an exasperating job of irregular- curve drawing can be made just as easy as the use of a triangle. A small sheet- metal clamp grips and holds the curve se- curely in any position by means of a HACKSAWS commodate the brick. The cleaner is rasped firmly across the face, making a clean thumbscrew set in one of several threaded holes in a regular triangle, and permits it to be moved_along in any direction, while it is kept in perfect alinement. The same curve section can be repeated any number of times at any desired intervals and with “%q (RON RODS : 4 job ot resur- na very few strokes.—G, A. Luers, ngton, D.C the assurance of getting it correctly lo- cated every time. A medium-size triangle vill be found preferable to serve as a base for the clamp. in making the holes, as a sharp screw will cut its own thread in celluloid. cabinetwork, I discov- he method of saving a lot of No tap is necessary Rubbing Down Varnish peg sins aTe Ss taken, however, not to make the blank hard holes too large. oing some They should be slightly and time when rubbing down the larger than the bottom diameter of the h with pumice stone. I have al- The clamp is made of ‘2-in. had a great deal of trouble to get spring brass or bronze, and should be nely powdered stone removed from _ slightly bent up at the ends and sprung mall interstices of the wood before up in the center, as indicated. All the ing the second coat and again later corners should be rounded. The thumb- On the last job I did, that of making screw should not be too large and must rary table of black walnut, I mixed a have a small stem with a fine thread simi- amount of the powdered pumice lar to screws in drawing instruments. In ome walnut stain. The result was the illustration, the arrangement is shown satisfactory. The object of mix- in laying out the flutes of a twist drill, e pumice with the stain was to fix it which can be accurately done in a short it if any small amount were left in time, a guide line being drawn to one side of the triangle to preserve the vertical ork it would be inconspicuous.—H. Neal, Noblesville, Ind. alinement.—H. Simon, Santa Ana, Calif. thread.

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This May Be Your Home LIVING ROOM 17*6 x 13-0 Pe its Et | , —— Le) SECOND FLOOR PLAN Plan No. 6A48 UESTIONS regarding home building addressed to this magazine will be answered by The Architect Small House Service Bureau of the-United States, Inc., controlled by the American Institute o! Ar tects and endorsed by the United States department of commerce. Inclose 10c and self-addressed enveloy $ Blueprints, specifications and material list for the house shown here may be obtained at nominal cost Ir close self-addressed stamped envelope for reply. If further information is desired, send 5c and stan envelope for a 24-page booklet explaining how the Small House Service Bureau functions and showing sample plans. A new booklet, entitled “Fifty Ways to Lower Home Building Costs,’ illustrated by t bureau houses actually lived in, and showing how as much as $1,000 can be saved on a home, may be « tained for 20 cents. pe * ar six-room Dutch colonial home, French door at either side of the firey of frame construction, combines ex leads to the sunroom. cellence ot I . economy of construction The first-floor bedroom and lavato and beauty of design. It is suitab'e for aspecial-feature. This room has two almost every locality. It can be built cna clothes closets and there is a linen cl fiftv-foot lot, and by omitting the su in the hall. porch, a forty-foot lot will do. The position of the stairs gives The interior is a fine example of skWifv' = great privacy, which is most unu planning. Very important are living and a smal! home. dining rooms of any home. These rooms On the second floor there are tw concern the comfort of the entire family. rooms. One is fifteen feet six In this home these are two fine’ big rooms square and has wall space for twit an arched opening with book It also has a clothes closet and ‘ither side. This makes them storage space under the eave one big room. The open fire enough to contain several trunks its cheerful blaze and In the kitchen there is a chance ‘ly autumn or spring breakfast nook to be built into one « both rooms. A as shown on the first-floor plan IN accordance with the editorial policy of this magazine never to accept compensation in any form what appears in our reading pages and also to avoid the appearance of doing so, we are obliged t the name of the maker or the seller of any article described. This information, however, is kept on file will be furnished tree, by addressing Bureau of Information, Popular Mechanics Magazine, Ch