Popular Mechanics 1926-05: Vol 45 Iss 5

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E PAGE 712

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ever tion i have not learned to m:ke repairs to will hi: I Pay Your Railroad Fare Myself **No more farmin hed forme. I’m leaving TRAINING FITS YOU FORA BiG Ray Jo tead .A D—at the left—what a pr any toe ee executive says. No w der automobile manufacturers 20,000,000 car owners are tearing ¢ hair and pleading—“Give us more tra iuto experts—quick.” Deliver us f; the urtaught, half-baked “ mec} who are working n illions of dollar age to our cars DAILY beecau don’t know their business In only 8 weeks I will train vo one of the 70,000 Big Money will be open this year | Your Money Back ST ot”’s: GUARANTE E D iade. I take all the risk. If at the end of your eight weeks’ instruc- 1 my school you are not perfectly satisfied with your training—if you autos, tractors, trucks and busses, | ind back every dollar you have paid me. You can’t lose. yo ~chat 400, goo me Y ¢ cars 34 che! While my Special Reduced Price Trainin€ Offer lasts, I will pay railroad fare to Cincin- nati. My course teaches you more in 8 weeks I wouldn't take $10,000.00 for what than vou wor Id learn in rl years as-a “handy t that ad ted oe ; man” around a garage. Don’t WorkA&es Bovis W AGES —$150.00 WEEKLY for British Honduras where Iam to get Lhave taight thousands. my boar d and lothes Ba and a salary ? ; . = 3 a bern nth . : two years con I can teach Vou. No schooling require d. Get a ur aining did i . “ “ - HERBERT PIERSON, Taswell, Tent into Business for Yourself! Own a garage and make profits of $5,000.00 a year upward. J) 7] ~ My graduates are doing it in all parts of the (| Co 4 | | Ou | country. ‘He Z ave just, sent one of my friend | | een : - your sch m doing fine mys | = aking $300.00 eve ronth rr . | Learn With Real Tools =" gies J. L. Jon on Real Equipment Benhan os ii No text books to stud You learn by doing actual work—easy, interesting, fascinating Why waste four years at small wages as 2 prentice to learn some other trade, when you can earn a ‘‘journeyman’s’’ pay in the busipess in only weeks? No union to join—No “card” required to get a stead ““As a good carpenter I used to work for $1.25 per hour. La . . Saat, allen Sitti oeab-cae Get My Big 64-Page Book and Special weeks course, l earne: ~ 90006. 00 sehen Reduced Price Training Offer wow. Mc be — W. Davison All I ask is the chance to prove to you every stat Sweeny Me ndicott, N. ¥, made in this advertisement Cet your feet unde Auto, \ jump out of the ditch up onto the smooth, easy-to-t1 Tractor and \ Success highway. Send the coupon TODA‘ sure Electrical ~ For every nickel or dime of profit that a man has made by d school, s laying and waiting others have made thousands of dollars t Dept. 140-A, ‘“ their ability to make up their miads and to act quickly—be Cincinnati, Ohio ™ the opportunitv was GONE! Do I need to say more? Without any obligation he send me your big free book on \ Autos, and your Special Short- rime Re Vame Street duced Price Training Offer thi ill AUTO, TRACTOR ano ELECTRICAL Sth & Walnut Sts., Dept. 140-4, CINCINNATI, OHIO

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POPULAR MECHANICS ADVERTISING SECTION 87 “I usep to think that because the Eveready B’ Battery No. 772 cost less than either of the larger Heavy Duty Evereadys that I was saving money. As a matter of fact, on four or five tube sets, that was false economy. “The right size Eveready ‘B’ Batteries to ise depends on the number of tubes in your set. The life of the batteries depends on how much you listen in and on whether a ‘C’ vattery is employed.” To get the maximum of “B* battery life ind satisfaction, follow “The little wrinkle that makes my ‘B’ batteries last longer is. using the right size Evereadys with a ‘C’ battery’’ On all but single tube sets—Use a“C” battery*. Follow these rules, and No. 772, on 1 to 3 tube sets, will last a year or more; Heavy Duties, on sets of + or more tubes, eight months or longer. The average year-round use of a set is two hours a day. If you listen longer, your “‘B” batteries will have a somewhat shorter life. If you listen less, they will last longer. Our new booklet, “Choosing and Using the Right Radio Batteries,” is these simple rules: On1 to3 tubes—Use Eveready No. 772. On 4+ or more tubes — Use the Heavy Duty “B” Batteries, either No. 770, or the even longer-lived Eveready Layerbilt No. 486. “Nore: A “C” battery greatly reases the life of your *‘B” bat- teries and gives a quality of recep- tion unobtainable without it. Radio ts may easily be changed to per- t the use of a “C”’ battery by any competent radio service man. Lert—No. 486, for 4, 5 or more tubes. RIGHT eady Dry Cell Radio **A’’ Bat- tery, 1% volts free for the asking. It also tells about the proper battery equipment for the yon new power tubes. vv. Manufactured and guaranteed by NATIONAL CARBON CO., Inc. New York San Francisco Canadian National Carbon Co., Limited, Toronto, Ontario Ever- Tuesday night means Eveready Hour—9 P. M., Eastern Standard Time, through the following stations: wear—New York wsat—Cincinnati wisat—Providence weran—Cleveland WEEI-—Boston wws-—Detroit wtaG-Worcester WaNn-Chicago wri-Philadelphia Woo—Davenport wor—Buffalo 5 Minneapolis wcear—Pittsburgh wooo { 8 Paul Ksp-St. Louis

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© 8. W. Clatworthy Artist's eer of Some of the Far-Traveling Butterflies and Dragon Flies Which Nightly Visit Ships Miles off the Shores of Tropical Islands, Attracted by the Glowing Lights—See Page 741

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REGISTERED IN U. S. PATENT OFFICE Popular Mechanics Magazine WRITTEN SO YOU CAN UNDERSTAND IT ‘ol. 45 MAY, 1926 No. 5 Radio Pen Draws Pictures from the Air Attachment, Plugged In in Place of Loud Speaker, Converts Radio Set into Receiver for Broadcast Pictures A.N attachment which turns the voice 4 of the receiving set into the skilled hand of an artist is the latest development from the laboratory of C. Francis Jenk- ins, inventor of the radio movies and a process for transmitting photographs through the air. The new device—the radio pen—does not require any special receiving equip- ment, but plugs into the loud-speaker jack of any receiver and its range is limited only by the power of the transmitting ap- paratus in the broadcasting station. The pen outfit is not much larger than a loud speaker, being contained in a box eighteen inches square and eight inches deep. Cartoons, maps, pen sketches, writing, anything, in fact, that can be reproduced satisfactorily in pen and ink, may be trans- mitted. At the sending end, the radio-pen transmitter is another small box, which can be plugged in on any existing broad- casting set, without changing the appara- tus, so that the broadcaster can alternate between voice or music and pictures. The sketch or cartoon to be transmitted is placed on top of the box containing the transmitting apparatus, and beneath the metallic transmitting arm, which sweeps back and forth across it, making and breaking the current. The original sketch itself can be used, or an electrotype or zinc etching, such as is used in reproducing the illustrations in a newspaper or magazine. The receiving pen is much like that at the transmit- ting end, except that it may be equipped with a self-inking pen at the end The Radio-Pen Transmitter, at Left, Sending from an Ordinary Engraving, and the Receiver, at the Right, Reproducing on Paper of the six-inch arm, so as to reproduce the drawing in ink. The system of motors and electrical connections is such that the two pens work in unison, like the arms of a pantograph, except that they may be separated by miles of space. When the arm at the sending end is depressed and swept across a line of the drawing, the radio signals, broadcast and picked up at the receiving end, cause a corresponding movement of the receiver pen. The pen opens a new field not covered by the previous devices for transmitting pictures. It sends from a flat surface, and receives and draws on another flat surface, whereas the photograph transmitters, em- ployving delicate and highly sensitive pho- toelectric cells, must necessarily employ either rolled films or a complicated system of expensive prisms to get the same result. “We believe that this pen-and-ink ma- chine has vast possibilities in the military field,” declared Capt. R. W. McNeely, chief of the radio division of the bureau of engineering, U. S. navy, who watched the first demonstration, when a series of pictures were broadcast from the naval station at Anacostia, D. C., and picked up in the Jenkins laboratory. “We are co- operating,” he continued, “with Mr. Jenk- ins to the full- est extent in developing these machines for war pur- poses. Just now we are blocked from taking over the inven- tion outright because of lack of appropria- tions, which is regrettable, but we nevertheless intend to keep in close touch with the future 705

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~> —) fr) POPULAR development work. The transmission of code messages, the sending of maps showing the location of enemy fortifications, machine-gun nests and transmission of written orders, with signatures in facsimile to prevent forgery, are only some of the uses that may be possible in war time.” MECHANICS C. Francis Jenkins, Inventor of the Radio Pen, Seated at His Receiving Set While the Apparatus Reproduces a Drawing Broadcast from a Distant Station, and, Inset, the Drawing, Showing the Pen- Made Lines ‘ * For public use the radio pen may hold infinite possibilities. With it the bedtime story could be illustrated with appropriate drawings, and daily cartoons transmitted direct to the listeners. ROADS SPRINKLED WITH SAND FOR INCREASED SAFETY After rains on one of the motor roads near London, a sand sprinkler is pressed into service to give the pavement a safety coating to reduce accidents. The mate- Sand-Sprayer in Operation on Pavement rial is distributed from a revolving drum at the rear of the truck and is thrown on both sides to a total distance right and left equal to the width of the driveway. BIG DREADNAUGHTS OF THE AIR TO CARRY TWENTY-FIVE GUNS Construction of two 6,000,000-cubic-foot rigid airships, each to be equipped with twenty-five machine guns for combating attacks from airplanes, is planned by the United States navy. Seven of the guns will be of the new 50-caliber type and eighteen of 30-caliber. The weapons are to be so placed that concentration oi fire will be possible in any direction or angle, according to Rear Admiral William A. Moffett, and the big ships will rely upon the non-inflammability of helium gas rather than on armor for protection from hostile planes. Already, it is said, the introduction of helium has necessitated revision of aviation tactics, for a ship so inflated cannot be exploded or easily set on fire. Even if the bags should be riddled by bullet holes, it is estimated that hours

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ould be required to bring the craft to the round through gas leakage. “The pres- t contemplated, but untried tactics of rplanes against helium-inflated rigids | for the former to get above the air- ip and bomb her with light demolition ombs,” Admiral Moffett explains. “A rht plane, moving at the rate of 150 iles an hour is: not con- ucive to accurate bomb- It takes twenty-eight econds for a bomb to drop ym. 12,000 feet. An error — half of > degree ath one-halt of one degree ho ~ om vertical of a bomb : Re ght causes an error of ver 100 feet in aim. Dur- the period of the bomb’s fall, if from 12.090 feet, a rigid moves one-half le on her course. The air- hip can bring her one-pounder, ur 50-caliber and five double-mount 30-caliber guns to bear on the attacking plane or planes. It is not conceivable that uccess is possible against such a volume of fire.” An airship of 6,500,000-cubic- feet-capacity, plans for which already have been drawn, used as an aerial transport could carry 750 men with individual fight- ing equipment 500 miles at a speed of eighty-five miles an hour and retain fifty per cent of its fuel reserve, it is estimated. WOMAN’S FOLDING FIRE ESCAPE LOWERS BY ELECTRICITY Devised by a woman seventy years old, an automatic fire escape is intended to be fastened to the roof of a building and low- ered past the windows simply by pressing a button. When not in use, it lies folded up under a protective covering. Pressing the button, raises an arm which lifts part of the ladder, allowing the rungs to fall over the cor- nice. The rest unhinge and follow, dropping close to the sidewalk. Being shielded from the weather when not in use, the escape is less liable to wear out, and since it is out of sight, it re- moves one of the ob- jections to the pres- ent types of equip- ment—that of disfig- uring the exterior of an otherwise attract- ive building. POPULAR MECHANICS Women Inventor with Model of Fire Escape 707 ROPE-WALK AND AQUAPLANING MEASURE MENTALITY A keen intellect is useful even in walk- ing a tight rope, according to tests with QU. &l Playing Ball While Surf Riding, a Difficult and Thrill- ing Sport Requiring Skill at Balancing students at Denver university. Fifty-six volunteered to walk across a tight thirty-three feet long, while checked their performance. It was found that those of superior mentality had less difficulty, their muscles were better co-ordinated, enabling them to replace useless, false movements with skilled ones more quickly. Learning to balance is easier when fear is eliminated, the experi ments showed. Students required fifty trials before they could walk across a rope stretched six feet above a mat on the gym nasium floor, but another group needed only thirty-eight trials when the rope was placed at three feet. It was also discov- ered that, when once the art of walking the rope was learned, it was not easily forgotten. Men came back after an ab sence of one or two years and walked the rope successfully at their first trial. In volving much of the skill required in keep ing the balance on a wire, a ball game played on aquaplanes has proved a keen test for steady nerves. The planes are towed at the rate of thirty hour behind a motorboat. Without using the customary hand ropes ror support, the play ers toss a heavy cage ball back and forth while speeding over the waves, keeping their balance whol lv by movements of their wire, observers miles an bodies.

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708 FIGHTING FIRES REQUIRES NEW IN SKY TOOLS Following a fire to the upper floors of a lofty building, or the tall steeple of a great cathedral has introduced new meth- ods and new equipment for fire depart- ments. Skyscraper fires, such as a recent blaze in the great Equitable building in New York, are a distinctly American dan- ger, but Europe has its own problems in her famous cathedrals. The Berlin fire department recently acquired a motor- driven extension ladder, seventy-eight feet high, able to support the weight of a fire- man at its tip while he directs a stream of water. These motor-driven ladders have simplified the task of fire fighting above the ground. With ordinary ladders placed POPULAR MECHANICS against the building, the fireman frequent- ly is driven back by the intense heat when he comes in close contact with a window opening. As the motor ladders are sup- ported by the truck base, they can be raised across the street, if necessary, and a powerful stream shot into the blaze while the fireman works in comparative comfort. The Equi- table building fire was unusual in that- it started in a shaft at one of the lower floors and sped upward, feeding mainly on electric-wire insulation, to break out into the building at widely separated floors. The worst damage occurred well above the thirtieth floor, more than 200 feet above the street. Firemen rode to the fire on the building elevators, and used the standpipes and fire equipment built into the building. SEED AND PLANT TRAVEL AIDED BY AUTOMOBILE Study of the travel habits of seeds and plants by Dr. H. A. Gleason, cura- - tor of the New York botanical gar- den, has revealed that nearly 700 alien species are growing near that city and similarly large num- bers are to be found in the vi- cinity of almost every thickly populated center. Commerce has greatly aided the world flight of plants, hundreds of species traveling about in ships, freight cars and auto- mobiles. A vessel takes on a load of earth as ballast and dumps it in a foreign port. If the climate is favorable, the seeds grow and plants dis- tribute themselves by natural means. Shipments of hay, straw used for packing, or consignments of clover and other seeds contain foreign seed ready to take root in almost any en vironment to which they are delivered. The natural methods of distribution are varied and often effective. The witch hazel, for instance, develops two hard black seeds at the ends of the pods and, when these dry, they squeeze the seeds until they are shot forth like small bullets, sometimes as far as forty feet. Others are blown through the air with the aid of tiny hairs or “sails” and some are so small that they travel! like dust. Among these are orchid seeds of which it takes 7,000,000 to weigh an ounce. Birds and other ani- © Henry Miller Huge Extension Ladder, Recently Added to the Equipment of the Berlin Fire Department, Being Tested Out before the Cathedral

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ils help distribute ant life, while ocean irrents bear seeds and uits to great distances. One of the commonest avelers is the dande- ion. It originated in Europe, but has now pread throughout the United States; the Amer- can prickly pear abounds n Australia; the Canada ind Russian thistles are ommon in many parts of this country, and the vild cherry is widely dis- tributed. Unwittingly, automobile tourists are doing much to help spread various kinds of plants from wilderness ireas to towns and cities. WEIGHT OF AUTO OPENS GATE Equipped with springs and specially constructed platforms, a double road POPULAR MECHANICS 709 gate devised by a Texas inventor, opens and closes without the aid of an operator. The weight of the automo- bile, which is driven upon the platforms, depresses them, actuating the mechanism which raises the leaves of the gate, and when the car has passed through, coil springs automatically return them to posi- tion, leaving the platforms in place for opening the gate from either side. Japanese Boys Snaring Dragon Flies on Lime-Tipped Poles the Insects Are Tied and Flown from the Sticks Auto Approaching Gate and, Below, Leaves of Gate Tipping Back under Weight of Car : When Captured, SNARING DRAGON FLIES ON POLE FAVORITE JAPANESE SPORT One of the most popular amusements among Japanese boys is the sport of catch- ing dragon flies on long poles smeared with lime. When the insects are captured, they are tied with fine string and flown from the sticks. The dragon fly is known to almost every part of the world except the polar regions, more than 2,200 specie: being classified. A peculiarity of some kinds is that they choose a favorite twig on which to roost and always return to it even after long excursions after food. SEA WAVES ACT AS “WIRELESS” TO GUIDE WHALES Washing of the sea waves is the “radio beacon” that warns whales, porpoises and many kinds of ocean fish to keep away from the shores and under the surface in stormy weather, according to Dr. Austin H. Clark of the national museum. As the waves break, their high-pitched, hissing sounds are easily located, Dr. Clark de- clares, and because the noise continues, it causes the sensitive sea keep away from it creatures to

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710 POPULAR MECHANICS Serving as a Strong Bridge over Deep Ravine, These Logs Are Doomed to Be Cut Up for Lumber When the Standing Timber Is Depleted RAILWAY BRIDGE BUILT OF LOGS IS HUNDRED FEET HIGH Spanning a deep ravine in an Oregon lumbering district, a bridge built of logs supports heavy trains passing to and from the sawmill, but is to be torn down and the pieces converted into lumber when available timber is cut from the area. The bridge is composed of 375 logs, from thirty to 110 feet long, and is 400 feet from bank to bank. Timbermen estimate that it represents about 500,000 / feet of fir and 250,000 \ he feet of hemlock. J, WOOL DERIVED FROM WOOD Prepared from cel- lulose, or wood fiber, artificial wool now being manufactured largely as a by-prod- uct from the syn- thetic - silk industry, is said to have the soft, warm feel of the natural article besides a lustrous quality, which improves the appearance of ment of commerce are of the opinion that the price of this substance will be be- tween fiftv cents and $1 per pound as com- pared to $2 a pound for natural wool, and one authority predicts that, in five years, the “wood wool” will be as common in our textiles as synthetic silk, which is now be- ing produced at the rate of about 4,000,000 pounds a month in this country alone. COCONUT SHELL AS “UKE” BACK REPLACES WOOD Hollowed and polished co- conuts are being used in Hawaii as sounding boards for ukuleles. The shell is tough and vibrant and by cutting a wide open- ing on one side, a sufficiently large sound chamber is formed to amplify the tones from the strings. The modi- filed instrument is calied a “cocolele.” The handle is made from koa wood. @According to scientists, cloth with which it is used as a Hollowed and Polished there is no insect that has a mixture. Officials of the depart- Coconut Shell Is Back for Ukulele fatal bite. —

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POPULAR MECHANICS 711 STEEL CYLINDERS FOR DAMS AID IRRIGATION Large steel cylinders that can be raised and lowered by electric power are being nstalled in an irrigation district in Mexico where the streams are subject to sudden The first of these was erected on . large plantation near Torreon. It con- ists of two cylinders, each sixty feet long and eight feet in diameter. They are oper- ated independently on heavy racks by power equipment placed on a masonry pier in the center of the stream. When in place, they form a water-tight reservoir, but can be quickly raised to reduce the store in times of flood. Another dam near by has cylinders ninety feet long and twelve feet in diameter and was built at a cost of $250,000. rises. OUTDOOR ICE BATH IN JANUARY IN NATION’S HOTTEST TOWN Guests of a bachelor hotel in a Cali- fornia town below the sea level, where the temperature rises to extreme heights even in January, are refreshed with ice baths outdoors at a small charge. Tubs are con- veniently located near the dormitory quarters, and the ice man delivers sup- plies directly to consumers. Government weather bureau records show that this town is the hottest spot in the United States during part of the winter season. Showing How Furnace-Pipe Units Resist Strong Pull, and Close View of Joints LOCK-JOINTED FURNACE PIPE ELIMINATES SOLDERING Held together by special lock joints, a type of furnace pipe now on the market, requires no soldering and can be installed with greater speed, it is said. A smooth, rigid line results, and as the pipe is made with an inner and outer wall, greater heat- ing efficiency is reported from it because of the dead-air space between the walls. FLOWERS AS CLOCK Knowledge of the ac- tions of various kinds of flowers and plants en- ables the observer to tell the time of day, as blos- unfold at nearly the same time dur- ing the proper seasons. Their hours of “awaken- ing” will vary in different parts of the country. In New Zealand, for in- stance, naturalists have discovered that most wild flowers open about six o'clock in the morn- ing. Various kinds fol low at more or less defi nite intervals. Chick weed, for instance, opens at noon, while the garden marigold goes to sleep at three o’clock in the after Soms Bathing Hour in the Nation’s “Hottest Town” ; the Ice Man Delivers Cool- ing Chunks to Patrons Enjoying Outdoor Tubs noon. Water lilies retire at four o'clock.

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~— Close View of Painting Rig and Long Cable Strand PAINTERS RISK LIVES ON CABLE TO PRESERVE POWER LINE Cranking their way back and forth over the lengths of high-tension cables stretched across an arm of Puget sound, near Tacoma, Wash., painters on an im- provised carriage had narrow escapes from death in coating the wire with a preserv- ative to protect it against the elements. Always far above the water, sometimes 600 feet and never less than 245, they were exposed to the brisk winds from the ocean which caused their frail platform and the cable to sway. There were six lengths in all, and each was over 6,000 feet long. It took about four hours to make one crossing when every- thing worked smoothly. The paint was applied from a box compartment fitted with brushes which came in con- tact with the cable as it passed through. Hitch Installed on Tractor and Detached Felt lining prevented the liquid from es- caping at the ends. The carriage was moved by a system of cranks and gears. At one point it “bucked.” In attempting to descend from a height of about 500 feet on a guy rope, one of the men fell and was severely injured. He was saved from death by becoming entangled in the ropes 300 feet down. UNDERSLUNG TRACTOR HITCH TO PREVENT CAPSIZING Like bronchos, tractors sometimes rear up when too great a haul is attempted with them. To prevent this, a Texas inventor has devised an underslung hitch attach- ment which is said to center the pull mid- way between the four wheels and, by exert- ing at the same time a downward pull on the front of the trac- tor, helps to keep all four wheels on the ground and aids in steering. It is also said to increase the traction, and as the hitch is equipped with a spring, it acts also as a shock ab- sorber.

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-— POPULAR MECHANICS 713 NLY ONE-FOURTH OF CANADA SEEN BY WHITE MAN seventy-five per cent of Canada has not been seen by white men, according to H. Knight of Ottawa, president of the ciation of dominion land surveyors. pointed out that travel is confined to known routes and few persons ever t the uninhabited regions that lie be- nd. Only a small portion of the coun- has been mapped, Mr. Knight declared. ym surveys made last year, it was dis- ered that the province of Ontario has suit 1,500 square miles more territory 1n was previously estimated. During exploratory trip in the northwest sec- mn of Canada, never before visited by hite men, a series of lakes, 200 miles long, ere discovered. It was also found that irts of the province of Quebec had sunk. WOOD PAVING SET WITH RUBBER TO PREVENT SKIDDING Surfaced like an automobile tire with rojecting insets of firm rubber, a section wood-block paving in England has een constructed to prevent vehicles from kidding. The special roadway lies paral- Knobs on the Pavement Instead of on Tires as an Ex- periment against Skidding el to one smoothly paved so that com- arative tests can be made. CA locomotive recently built in the east contains 203 tons of steel. Playing a Musical Selection with Mixing Bowls for Radio Audience; Tones Resembled Chimes MUSIC FROM MIXING BOWLS PROVIDES RADIO NOVELTY Crockery mixing bowls of different sizes were used in playing musical selections from a radio station recently. Clear bell- like notes were produced but without the overtones that generally attend ordinary bells or chimes, it is said. Enough bowls were selected to give the notes of two complete scales and small hammers were used to strike them. TREAT FOOD WITH ELECTRICITY TO IMPROVE HEALTH By exposing certain kinds of foodstuffs to ultraviolet rays, the Scottish board of health is reported to have discovered a way for restoring vitamines destroyed in cooking. It was found that some kinds of food that tended to cause rickets were made entirely safe by this treatment. Milk, exposed to the rays, became richer, it was said, while a substance known as choles terol, inherent in many foods, was made beneficially active by this application of electricity. For some time, ordinary elec tric light has been used for ripening or- anges and other fruits. It is said to pro- duce a better color than sunlight. Ultra violet-ray treatments with quartz lamps are reported to be efficient in many cases as substitutes for sunlight.

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714 Where Trains Soon Will Be Thundering under the Rockies; Entrance to the Great Moffat Tunnel Which Pierces the Continental Divide LONG TUNNEL UNDER ROCKIES TO AVOID SNOW BLOCKADES Opening of the six-mile Moffat tunnel under the continental divide in Colorado, scheduled for 1927, will permit more regu- lar train service during the winter months especially, it is predicted, as delays due to snow blockades through that district will be avoided. Construction started from the east and west sides, the eastern portal having an elevation of about 9,000 feet and the western 113 feet lower. To secure ventilation, suction fans are to be installed in the tunnel, and to eliminate as much smoke as possible, locomotives will bank their fires before they are to pass through. @The earth is likely to 8uTT be struck by a comet only —-— : once in 20,000,000 years, Sagrrrscte scientists declare. was POPULAR MECHANICS PLANES FEED BIRDS DURING WINTER Airmen went to tl aid of the birds last wit ter in the snowy Alk ghanies, dropping ea corn and other food fror their planes. One aviato made half a dozen flight in one day, throwing out more than 150 pounds oi feed, which was supplie by the Pennsylvania stat¢ game commission. An advantage of the schem: was that it reached th: birds near their native haunts. While many species are to be found near the cities and in parks where they enjo food supplied to them, others do not frequent settled districts and sut fer severely when there is a scarcity of feed. AMPLIFIER PHONE ON TROLLEY CAR CALLS STREETS For the convenience ot passengers and to permit wider use of the so-called “one-man” street cars an electric amplifying apparatus for the motor intended to enable oc cupants of the car to hear street names with little difficulty. The system used 1 aid to be one that causes no distortion ot the voice. The motorman wears a breast plate transmitter which is plugged into a jack at the end of the car. By pushing a man’s voice is foot switch, the amplifier is put in use and the sounds issue from a loud speaker that is mounted.in the roof in the middle of the car and has two horns directed to ward the back and front. me & a a .—I BATTERY / | 4 @ ~ TRANSFORMER. @ a Te gee es = = Sketch of Street-Announcer Apparatus as Installed for Use in Car; Motorman Speaks into Mouthpiece Strapped to His Chest

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eDS R Vil Wit ron ito rht out +r lied fate An -Ine the tive any ind in »m, ent ut ere )N an POPULAR MECHANICS 715 Driven Ashore in the December Gale, the Crew of the ‘“‘Comtesse de Flandres” Was Rescued by English Coast Guards Who Fired a Rocket Line for the Breeches Buoy irom the Cliffs on Land NVENTIONS of the twentieth century, not in use until this decade, have saved rom death this winter scores of men in the most bitter gales in the memory of the present generation of seamen on the \tlantic. Early the morning of January 24, a radio perator brought to Capt. George Fried of the United States liner “President Roose- elt” an SOS from the British freighter \ntinoe.” The “Antinoe” was helpless n mid-Atlantic and being smashed and pounded by mountainous seas. Fried’s hip was nearest. The position given in the message indi- cated the “Antinoe” was 100 miles away. \fter the captain had changed his course he sent word to the “Roosevelt’s” radio operator to check the position of the “An- tinoe” with the radio compass, a device not installed on American ships until three years ago. The operator carefully manipulated his compass and then rushed word to the “Roosevelt’s” bridge that the “Antinoe” had given its position many points of the compass from the actual position. It proved later that their skipper’s figures had been wrong by 100 miles. He had little chance to be accurate with snow and hail making astronomical observations im- possible. Only a few years ago the “Roosevelt” would have received the SOS but probably never would have found the “Antinoe.” The men of the latter would have died as their ship plunged down while the “Roose- velt” was searching through hundreds of square miles of terrible seas. The base of the radio compass is a large dial, marked with the points of the com pass, and having an indicator placed over it which is attached to a loop aerial over head. The aerial is on a pivot and can be turned in any direction by the operator. When the radio operator of the “Roose velt” was seeking the position of the “An tinoe” he turned the aerial until the dot- dash buzzing the aerial was receiving from the “Antinoe” was loudest. He noted the compass direction of the loop aerial and that was the bearing of the “Antinoe” from the “Roosevelt.” His record was accurate. His success had depended en- tirely on his sense of hearing, which seems untrustworthy to the layman. But the use

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716 POPULAR MECHANICS Lifeboat a of Roosevelt”’ in the First, and Fatal, At- pt to Rescue the “An- tinoe’s”’ tem Sea We Bat men in the ‘‘President Being Lowered Crew; Two of the This Picture re Drowned, and the tered Away Bc in at Whirled the Storm Crew of United States Coast Guards, Above, Prac- ticing Life-Saving Drill by Capsizing Their Boat in the Sea; the Picked Men of the Rescue Crews Must Be Familiar with the Behavior of a Boat in a Storm and Know How to Right It if It Upsets and Top- ples Them into the Sea; These Non-Sinkable Boats, Buoyed by Air Compartments in the Ends, Are Specially Designed with Hand Ropes Underneath So That They Offer a Hold for the Crew Even When Bottom Up and Can Be Righted Again A Successful Rescue, Showing the Twenty-Seven Sailors of the ‘‘Alkaid’”’ Being Hoisted aboard the “Westphalia,” Which Saved Them from the Sinking Dutch Freighter; the Gale Was So Bad That the Battered and Fast- Sinking Lifeboat Was Cut Away and Abandoned a Few Moments Afterward

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POPULAR MECHANICS 717 the compass this winter has proved its =a uracy is almost mathematical. It is so ; tain in results that it may do away with hthouses, radio beacons taking their ce. in Captain Fried’s report to the United tes lines he told of locating the “An- e” with the radio compass and con- ued: ~ ‘We arrived alongside her at noon with - wind west at sixty miles, accompanied : violent snow squalls and high rough a ;, in which we were rolling thirty-five grees. | took position a quarter mile to wind- ird and poured oil overboard with excel- t effect. Her captain claims this saved e ‘Antinoe’ from sinking. “IT lost sight of her at 9:00 p.m. Her lio and dynamo were out of commission nd there were severe snow squalls. earched and picked up the ‘Antinoe’ iin 3:40 p.m. on the twenty-fifth with ngine and fireroom flooded, No. 3 hatch t roken and boat listing heavily to star- ard.” The officers of the “Roosevelt” did not elieve the “Antinoe” could live through he night. Its starboard lifeboats had been wept away, the port lifeboats were stove n and useless, the steering gear was dis- bled, the navigating bridge wrecked by the fury of the seas, and the crew had only i flickering oil lamp for signaling. Capt. Fried ordered away a lifeboat with chief officer Miller in charge. It was lung overside and lowered away. It was 1 Lundin boat, one of the strange-looking hallow tubs that have been adopted re- ently by several of the largest passenger liners. As it struck the water, its tackle vas loosed and the men put their backs to veeping the oars. They had taken a few lesperate strokes, when a violent squall broke and the boat was whirled back to the “Roosevelt.” As life lines were cast when it came alongside, a giant wave caught the boat and jerked it up perpen- dicularly to the water. Miller and his crew were pitched into the sea. High ibove them a dozen life lines were thrown, sea ladders were dropped and cargo nets were let go. All but two managed to reach the ship’s side and were pulled to \ the deck. “We made every effort,” Capt. Fried re- i ported, “to pick these men up, but were handicapped by darkness and continued snow and hail. Used powerful search- lights. Weather increasing. “The twenty-sixth, continued on station J distributing oil on weather side. ‘Antinoe’ showing one lamp. Her distress signals as arts xe

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718 POPULAR MECHANICS indicated perilous situation. We attempt \ ed to float boat to her by aid of Lyle gut The boat reached the ‘Antinoe’ but s!] \ lost it. Tried floating a cask and faile: “Fired Lyle gun sixteen times. Lin: carried away near projectile frequent! \t the suggestion of Colonel Hearn, arti! lery expert, who was a passenger, uss spiral springs between projectile and line which was successful.” } The lines which reached the “Antinos were lost and this method of rescue finall was given up. The Lyle gun is a sma smooth-bore gun which throws a proje tile weighing eighteen pounds. The pro jectile has an eyebolt which extends be yond the muzzle and is attached to the line. After a day of working with the Lyle gun Providence brought help when the gale and sea moderated somewhat nightfall, enabling the “Antinoe’s” crew t be taken off after six lifeboats had beer lost. Without the Lundin boats it is extreme ly doubtful if the crew could have beet saved. Chief officer Miller talked of ther with enthusiasm when the “Roosevelt reached Queenstown with the “Antinoe’s’ crew. These boats are built of heavy steel but are unsinkable and self-bailing. Those carried by the “Roosevelt” are twenty feet long by eight and two-thirds feet wide a . a The “Westphalia’s” Lifeboat Being Low- ered to Rescue the ‘‘Alkaid’s’’ Crew, and the Last View of the Latter Ship, Which Was Set on , Fire to Prevent Its ~ Becoming a Men- we ace to Navigation Sl may Ct LOE HLT eens ets

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POPULAR MECHANICS 719 Coast Guardsmen on Long Island Launch- ing Their Boat in a Heavy Surf as Part of the Regular Life-Sav- ing Drills Which They Undergo to Keep Fit = Firing the Life Gun, Which Carries the Light Line from the Reel Out to and over a Sinking Ship, Fol- lowed by the Breeches uoy Hauling the First Man Ashore in the Breeches Buoy, One of the Most Effi- cient Rescue Methods in Use —— — ———_— —— |

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720 POPULAR MECHANICS and carry fifty persons. They are shallow boats with nine water-tight compartments under § the deck. Each com . partment has a manhole so that it can be paint ed on the inside. Through them, from the steel deck to the under- side of the hull, run pipes, open at each end, which carry out any : * water on the deck. The | The Life Car, Top, Successor to the Breeches Buoy, Will Carry Ten People through the Waves in Comfort; Below, Lifeboat Drill on the ‘‘President Roosevelt,”” Showing the Safety-Type Boats buoyancy of the boats is entirely due to the air-tight compartments, and the boats cannot be sunk unless these compartments are smashed. They cost $1,800 each. Another valuable aid to the seaman in rescue work is the rocket, which has been in use for years. In principle it is like the small boy’s rocket for the Fourth of July, but the simple device has aided rescuers to find ships in scores of instances. All of the liners carry powerful search- lights, required to be always ready for use. The ships have bottle-shaped flares at- tached by lines to lifebelts on the rail, to be thrown overboard at night whenever a man is swept overboard. Before a flare is thrown, a pin running through it is pulled out. As sea water gushes through the open ing, it touches calcium chloride, forming acetylene gas and calcium phosphate, which ignites when coming in contact with water. The fire from the calcium phosphate sets the acetylene gas burning and makes a light of 250 candlepower The flares in ordinary use will burn fot three quarters of an hour. One of the crews saved by the radio compass was that of the Dutch freighter “Alkaid,” sunk in the Atlantic. The men were brought into New York by the “Westphalia,” February 7. es

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C.F ee ae Pee POPULAR MECHANICS H GE DAM TO WATER DESERT Examining Pendulum in FOR RAISING COTTON ening of the great Sennar dam, he Blue Nile in the Sudan, is ex- ted to make some 300,000 acres of iously barren land suitable for the uction of cotton. A crop of 400,- 000 pounds a year is anticipated n irrigation and cultivation are y developed over the area. The dam onsidered one of the great engineer- feats of the world. Erected at a t of more than $50,000,000, it is two es long, required the excavation of (00,000 cubic yards of earth and the erection of 15,000,000 cubic yards masonry. It holds back waters it ordinarily rushed to the sea d were largely wasted during the eason of heavy rains. Four years ere spent in building the dam and e work gave employment to ousands of natives who labored le by side with modern excavat- ng implements. In mid-channel it ninety feet thick and 130 feet eep. It has 206 sluices and spill- ivs and the irrigation canal that part of the project is sixty-six les long. MEMORIAL TO WAR FLYERS ERECTED NEAR PARIS In memory of the famous Lafayette es- idrille, a stone arch with facades to be nscribed with the dead and living mem- ers of the unit, is under construction in park at St. Cloud, near Paris. The ‘rench government has set aside sixty cres for the monument, which is being uilt as a result of an endowment, pro- ided by a New York and Paris lawyer, it a cost of about $125,000. The main irch will be over seventy feet high and vill stand in an open glade in the midst of a forest. Model of Memorial Built to Honor Members of the Lafayette Escadrille, One of the Famous Flying Units during the World War ~? 2 —_— 100-Foot Shaft HUNDRED-FOOT PENDULUM SHOWS EARTH ROTATES Students at the university of Iowa have a graphic illustration of the rotation of the earth in a pendulum suspended from the top of a 100-foot shaft with its weight, a round ball weighing 100 pounds, adjust- ed over a graduated chart. Started swing- ing back and forth in a certain plane, the pendulum continues to oscillate in this plane, but due to the rotation of the earth, the plane apparently is turning in a clock- wise direction, making one complete revo- lution each twenty-four hours like the earth, whereas it actually is the chart that turns with the earth. This instrument is an adaptation of the pen- dulum devised by Jean Foucalt, and demonstrat- ed in Paris in 1851. To assure accuracy in start- ing, it was drawn aside and tied by a silk thread which was then severed by burning it off.

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~> ee © FLEXIBLE “GLASS” FOR AUTOS TO INCREASE SAFETY Service in many fields is anticipated from a synthetic glass, the result of sev- At One Stage in the Manufacturing Process, the ‘“‘Glass”’ Can Be Poured like Thick Sirup eral vears of experimenting by two Aus- trian scientists. The product is made of organic materials, is said to be hard, per- fectly transparent and colorless and yet is so flexible that sheets and rods of it can be bent to a sharp curve or can be dropped upon the floor without damage. Even if it is broken, there is practically no likeli- hood of injuring the hands, for it does not splinter or leave jagged edges. This fea- ture, especially, commends it for use in automobiles for windshields and windows, but it is expected to make serviceable insulating mate- rial, can be used in the textile trades, for trans- parent fuel tanks, dishes and glasses, and, pos- sibly, for telescope lenses. Like quartz, it permits the ultraviolet rays to pass and thus opens up possibilities of great- er adaptation of this treatment. It can be turned, drilled, cut, filed and polished, or etched with acids, and its specific gravity is only about one-half that of glass. The product is said to have been formed from formal- Right, Wheels Tipped Up to Show Independent POPULAR MECHANICS dehyde and urea: At one stage preparation, it assumes a liquid torm can be poured like thick sirup. A made of the glass bounded to a height more than twenty feet when hurled t stone floor, and was not damaged. DAMAGE TO TREES BY INSECTS HUNDRED MILLION YEARLY Damage done by the some 200( known kinds of insect pests that atta trees is estimated at approximately $1(¥ 000,000 a year, according to a bulletin the American Tree association. Some a thorities say that the loss from this cau is greater than that from forest fires. a single section in Oregon, enough tres to build 8,000 homes costing about $10.0 each were killed by boring insects. Ce tain pests prey upon one another, thu protecting the trees, but the greatest nat ural allies of the forests are the birds, an in many parts of the countfy measur have been taken for their preservation SIX-WHEELED AUTO. TRAILER CARRIES HEAVY LOADS For transporting steam shovels, roa rollers and other heavy constructio: equipment, a six-wheeled auto trailer ha a capacity of twenty-five tons, yet is designed that the legal limit of weight upon any one tire is not exceeded. Thi is made possible by the installation of tw: short axles in the rear. They move inde pendently of each other and can be co: pletely revolved in a vertical plane. Thi distributes the load between the tour reat wheels and provides the necessary bearin on road surface at all times, to comp! with traffic regulations. The same con Pai f R . pan ; _ ae — front axle. The entire loa Axle is thus carried at three points, two in the rear and one in front, further relieving the trailer of undue strain. struction is followed in the

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POPULAR MECHANICS 723 Zoo an e “Ship of the Desert” Going, Aboard a Ship of the Sea at a North African Port on Its Way to a Foreign ephants Also Are Handled in These Derrick Slings Giraffes, Rhinos, Elephants and the Blood-Sweating Behemoth, a Ton or So of Hippopotamus, Come High These Days By JOHN T. BENSON fb. ERE are two questions that interest he who visit our animal farm at Nas- N. H., where all the wild beasts im- oul from Hagenbeck’s for the Ameri- in circuses and zoos are acclimated and andled after arriving from Germany, here they have been trained. The first is why we don’t import more iraffes and rhinos, which, next to the lephant, are the favorites of the big \trican animal class. lhe second question is whether the high st of living has affected the price of wild nimals in the same proportion as it has ther commodities. \nswering the second question first, it s; but after I tell vou the story of how nimals are caught, transported . and rained, I think you will agree that they re worth all they cost. As for the falling off in giraffe and rhino mports, the reason lies in the growing carcity of the first and the savage dispo- —~—>— sition of the second. Not that the rhi noceroses seen in the circus or zoo over here are dangerous, for they were caught as babies, weighing only a half ton or so, and grew up in captivity, accustomed to being fed and cared for by men. 3ut when the animal collector in Africa goes out after a baby rhino and disturbs the peace and happiness of a two-adult- and-one-infant rhinoceros family, it is something else again. The adult in the wild has about the shortest temper of any animal known. It will charge anything or anybody on the slightest provocation. Take a ton and a half or two tons of rhino, armed in front with a single long bayonet horn, let it lower its head and start after you with the speed of a flivver on a good road, and it is time for the ani- mal collector to keep cool and his nerves steady. It isn’t pleasant to fancy that bavonet horn sticking through one, or that 3,000 or 4.000 pounds of mad rhino stand

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724 POPULAR MECHANICS ing Over you tramping you into the earth. It is almost impossible to capture a baby rhino without a few men being hurt. and not infrequently some lose their lives. Sesides the difficulty of capturing a calf, the rhinos are all privately controlled by the rulers of each district, and it is neces sary to get a special permit and pay a stiff fee for the privilege of trying to catch one and if you don’t catch it, you don’t get vour fee back. The armorplate rhino of India, for which the Roosevelt brothers recently have been hunting, is even harder to get—if the native maharajah can be persuaded to issue a permit. Like the rhinos, the giraffes are pro- tected by law and can only be hunted un- der permit. When the hunt starts, we Left, Gorilla, One of the Only Tw in Captivity, Arriving in New York; Aboye, the‘ Chimpanze« Most Humanifke of the Monkey in Its Winter Undérwear; Below Is a Rare Ring-Tailed Lemur ayy *

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POPULAR MECHANICS 725 © John T. Benson The Big-Game Hunter of Hagenbeck’s in Africa, with a Party of Native Bearers Carrying in a Young Live Rhino, Trapped and Partially Tamed after Weeks of Hard Work can't follow the movie-expedition method ind round up a herd and chase them ilong before an auto until they are run out of wind. Any animal which has been run down and captured never lives long n captivity. Ask any race-horse man and he will tell you that when a horse has been ridden or driven bevond its limit it breaks either its wind or its heart. And so it is with all hoofed animals. \fter our collector is on location and he and his horses and men have rested, t is easy to locate a band of giraffes, but to separate a yearling from its mother and he rest of the herd, and then capture it ithout exhausting or injuring it, is quite inother matter. Then we have to get it back to the nearest of our African farms, which may be 200 miles or more away; get it contented and used to its surround- ngs; coax it to eat and drink, and finally pack it in a shipping box which must be upholstered like a parlor-car chair. The nearest port to the farm is eighty miles away, and the big box must be hauled over the roughest kind of road, and upon arrival at the dock, it stands for a day or two with curious crowds con stantly peeping in and annoying the youngster, with switch engines puffing and whistling all around, and a very bed lam of noises from the other animals which have been gathered to make up the cargo of the modern ark. The young gi raffe hears the roaring of lions and leop ards, the howling of jackals, the snarling hyenas, and through all this noise, our giraffe has to stand in its box half fright ened to death, while we endeavor to secure a good location on the ship where it will be quiet and comfortable and have plenty of fresh air until it is unloaded at Ham burg, to get its land legs and rest at the European farm. Then it must be repacked and make another long sea trip to Amer ica, a fourteen-day journey, be unloaded and acclimated again, and finally delivered safely to its new owners. Elephants, the most wonderful of all animals, have gone up in price along with ee

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726 POPULAR MECHANICS les the others. I say the m wonderful, because | lieve a good elephant is t most tractable of all w animals. But the questi arises, how you know good elephant. Well, th requires years of expe ence, and it is partly for th experience that one pa when he buys an elephan An expert can easily pick : good animal from a ba one, and let me tell you that a bad one is mighty poo property. There are two reasons fo the rise in prices of goo elephants. One is that the are in very great deman and the other is that the supply is not so good as formerly was. Our collec tors have to go farther int: the jungles and spend muc! more time rounding up herd, and selecting and separating the best of them Labor is higher everywher« and all these things go t make the price greater. When the Zoo Ostrich Gets a Sore Throat It Uses Up Sev- eral Rolls of Bandages, for, Like the Giraffe, the Ostrich Sore Throat Is No Mere Local Infection; Below, the African Game Hunter and His Wife Are Training a Couple of Lively Youngsters to Eat from a Pan © John T. Benson

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Piaget om POPULAR MECHANICS 727 ' ( “me i 2 “Alice,” the Baby Zebra of a Western Circus, in an Annual Consultation with the Doctor before the Show Goes into Winter Quarters Even a Baby Giraffe, Caught on the Veldt, Is Difficult for Sev- eral Men to Handle Baby Elephants Roaming the Decks, Monkeys Perched Everywhere, and Gi- raffes Sticking Out of Crates Lend Color and Interest to an Animal Ship Three Specimens of Rare African Gazelle, Caught by the Big-Game Hunters, Being Trained to Drink from a Bottle in Preparation for Shipment to Civilization Top Left, Center and Bottom Photos © John T. Benson

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728 POPULAR MECHANICS There was a time, not so many vears ago, when the elephant drive vielded a good harvest, say a hundred or so young ones, from which a number of perfect specimens could be selected. But now we are fortunate if we get eight or nine good ones from a hunt. After they have been rounded up in the Indian jungles, the procedure is much the same as with giraffes. Some are selected for training and are divided into groups of various numbers, depending upon the circus act for which they are to be used. Others are taught to carry a howdah and allow children to ride on their backs. Elephants are always caught in the dry season, when their nat- ural food is the poorest, and they have to tramp for miles to get a good meal. Asa result, they are always in poor condition and have to be fed up for weeks before they can stand the first sea voyage to Hamburg. There is no young animal, ex- cept the giraffe, which is more subject to ills than an elephant. They require a lot of nursing, but once they become accli- oa aliwavs When a Young Giraffe, with Its Long Legs and Queer mated they will, with proper care, live t a great age. Only a few years ago a thirtv voung elephants left Hamburg, and only twenty of them ar rived, because of storms at sea. The all have been paid for in the jungles, August, and it is March or April of th: next year before the first one is ready for sale, while those being trained may not ¢g on the market for a vear or two; so you can see that dealing in animals is an ex pensive and precarious business. There is another big animal which always draws a crowd to its tank in circus or zoo, and that is the hippopotamus Since the davs of Barnum, when the first hippo seen in this country was billed a the “blood-sweating behemoth of Hol Writ,” they have been TI shipment Calcutta { favorites. he hippo got its nickname from the fact that the pores of the skin open when they have been out of the water any length of time and the pink underskin shows through while drops of water falling from it ap pear to come out of the hide and lool blood-red against the pink background. The capturing of one of these big brutes is one of the most interesting stories of jungle lore. The hippo spends its days immersed in a pond, sticking its snout up occasionally for air. When one of our ex a © John T. Bens» Gait, Takes It into Its Head to Run, the Man on the Other End of the Rope Has His Hands Full and His Feet Busy

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POPULAR MECHANICS 729 litions locates a pond, collectors wait until e monster has gone in - a bath, and then dig ten-foot-deep pit in the inway it uses, since the ppo always follows the ime trail. The bottom i the pit is covered with ranches to break its fall, nd the top roofed over ith light sticks, leaves nd dirt, to restore its natural appearance. \Vhen all is ready, the atives are sent around he pond to beat on tin sans and frighten the nimal out of the water. t dashes madly up the unwavy and falls into the pit. Thena cage without i bottom—just four sides nd a top—built of hard- oods and tough vines, brought up and placed iver the opening, and rmly lashed down to the ear-by trees. As soon is the cage is secure, the Tree Cottagers Have the Luxury of Abundant Cold Running Water Always men start shoveling the dirt back into the hole ind the angry hippo tramps it down until t lifts itself right up into the cage. The capture has only just begun when the animal is in the cage, for it must be eft there to become more or less recon- ciled to conditions. This may take days or even weeks, and all the time the cap- tive must be fed and watered and kept sprinkled with water. Finally, a bottom ior the cage is made of saplings and slid under it, securely fastened, and the ani- mal is ready to start its journey to the farm. The cage floor is covered with leaves and oss to keep the hippo from becoming footsore or bruised, and also to hold the moisture, for it must be kept constantly wet. Long-poles are placed through the cage, and gangs of natives carry the bur- den out of the jungle on their shoulders. No zoological collection is complete without at least one of another species ot \frican wild animal—the zebra. These pretty creatures roam in herds of consid- erable size on the African uplands, and in order to select the young ones suitable for export, it is necessary to build an enor- mous corral, round up the whole herd and water it for days, and sometimes for weeks, until they are quieted down and the selection can proceed. ——i—— at Hand and Radio for Entertainment CABIN BUILT IN SLOPING TREE CONTAINS THREE ROOMS Reached by steps upon a sloping tree trunk, a cabin built among the branches gives a group of young men in a Pennsyl- vania town a novel retreat for camping parties. The house contains three rooms and has the additional advantage of being protected from damp ground and insects that often mar the pleasure of living in such woodland cottages. A brook at the foot provides water for cooking purposes. LOCK FOR SPARE AUTO TIRES SCREWS ON VALVE STEM Spare tires are protected against theft bv a lock that screws on the valve stem and fits. tightly against the rim A key is needed only in removing it, and there is a spring - steel dust vuard to keep dirt from getting into the mechanism. If desired, the lock can be used on running tires.

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730 POPULAR MECHANICS PUPILS TAUGHT BY RADIO IN WEEKLY LECTURES ae 4 — =o ) On | ® BrringoSivien WA Wa The Gerbocorsen Pupils in English School Listening to Talk on the Caribbean Sea, Broadcast from Station in Birmingham; Weekly Lectures of This Sort by Radio Supplement Regular Classroom Work Radio has become a practical addition to the teaching facilities of an English school system as the pupils are given a lecture once a week from a distant broad- casting station on some topic associated with the work they have been studying A loud speaker placed on the teacher's desk enables them all to hear distinctly, and they take notes while the lecture is in progress. AUTO BRAKE-BAND ADJUSTER SAVES TIME AND WEAR Brake and transmission bands on small automobiles can be accurately ad- justed from the seat with an at- tachment oper- ated while the car is moving, thus giving better re- sults. It can be installed in half an hour with screwdriver and W rench, and con- sists of a cover plate to replace that already on the automobile’s transmis- sion and three adjuster stems which are substituted for the ordinary adjustment nuts. These project upward to the level of the floorboard, which is perforated ,to receive them. The other ends of the stems pass through slots in the transmission plate. With a special key, the stems are turned from the seat. to take up slack in the bands or loosenthem,as needed. Much finer adjustments are possible with this device than with the nuts, it is claimed. SUGAR AND RUBBER PRODUCED FROM SUNFLOWER AND BEAN Oil of the soybean is the source of a rubber substitute scientists have prepared recently, and from a common kind of sun flower, known as the Jerusalezx. artichoke, chemists have extracted a sugar which is said to be fifty per cent cheaper than the cane or beet product, and sweeter, too. Two pounds of it will take the place ot three pounds of ordinary sugars, it is re ported. The plant from which it is de- rived grows wild in many waste places from Mexico to Labrador, and can be cultivated to give a yield of sixteen tons or more to the acre. Whether the rubber substitutes will be useful in the manufac ture of automobile tires and parts has not yet been determined. @The Popular Mechanics’ Bureau of In- formation offers its free service to all readers of our magazine. Names and ad dresses of manufacturers and dealers in articles described and any other details in our possession will be promptly furnished.

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)OUBLE PRINTING FOR MOVIES TO SIMPLIFY PRODUCTION Elaborate motion-picture sets will be necessary, and studios will need to be vy a fraction of their present size, in opinion of a Danish director, as the ult of an improved double-printing ocess. The details of the method are ing kept secret, but it is said the process nsists mainly in having the actors per- rm their parts in front of black-velvet ops and supplying the scenery later from all, accurately constructed sets or re- roductions of other pictures. It is now d to be possible to show characters, ho really are in the studio, as though ey were traveling in a boat up a river an Amazon jungle. The expense of king companies on location for the sake special backgrounds will be spared, it predicted. Use of this system already is been made to some extent, but much reater possibilities are anticipated from ecent improvements. RING THAT CARRIES PERFUME SHOOTS SCENTED SPRAY Concealed under a cameo setting in a vel ring now on the market is a tiny mtainer filled with perfume. Pressure the finger actuates a spring arrange- ent and a spray of the scent is sent forth. he design is said to have been inspired the ancient poison ring, in which dead- ng Open to Show Tiny Space for Carrying Perfume Concealed beneath the Setting potions were secreted for use against enemies or for suicide. @In one year, a single oyster can pro- luce as many as 1,000,000 new ones. POPULAR MECHANICS 731 SEPARATOR FOR OIL AND WATER TO SAVE FISH AND BIRDS For removing the film of oil often spread upon the water by ships in harbors Studying Tank of Goldfish After Oil in Water Has een Removed by Special Process and rivers, an apparatus devised by an eastern inventor is expected to accomplish much toward protecting birds and fish from polluted waters. Sometimes a smothering coat of oil is driven inward from a considerable distance at sea, mak ing it impossible for fish to obtain the necessary supply of oxygen and clotting the feathers of birds so that they are un able to fly. TEN THOUSAND MILES OF ROADS PLANNED THIS YEAR FOR U. S. During 1926, the federal bureau of pub lic roads plans to spend approximately $95,000,000 in adding some 10,000 miles of government-aid highways to the present system. Much of this money will be spent in and near the country’s national parks and through the mountains of the we where public playgrounds are being devel oped and opened. The task of cutting highways through forests and ranges 1s not always simple. Care must be taken in blasting not to cause destruction of scenic mountainsides; timber stands must be protected, if possible, by building trails around them, or if that is not feasible, through them, with the least practical loss and great vigilance must be exerted to pre vent fires while the roads are being con structed.

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32 POPULAR MECHANICS Under the Glare of an il Flare, the Desert Pipe-Line Layers Slept While a Sentry, Armed with a Spear, Stood Watch to Warn of the Approach of Marauders Steel Pipes Conquer Desert Wastes Oil and Water Lines, Carried across the Sands on Camel Back, Introduce Modern Transportation to Persia and the Sudan YTRETCHING 150 miles across the burning waste of the Persian desert, a double line of steel pipes has just been completed after ten years’ work to carry oil from Maidan-i-Naftun—the “Valley of Oil”—to the port of Abadan, on the Persian gulf. When the oil was turned into the pipes, one of the most traveled camel-caravan routes in the world was abandoned for this purpose. For years all the oil from the interior valley has been brought ta the coast on camel back, and ferried across the Tigris in native “gufas,” small circular coracles built of wicker and plastered with pitch. At almost the same time the Persian oil line was completed, another desert project was finished at Port Sudan, on the Red sea, which has finally acquired a water- works by tapping the springs of the Khor Arbaat valley, in the Red sea hills. Until the present, the port’s only fresh water came from distilled sea water, a limited and expensive supply. The operation cost so much that the occasional steamer that stopped there for water was forced to pay $2.50 a ton, an almost prohibitive price. Finally an engineer conceived the idea of piping a supply from the springs in the hills twenty miles behind the town, at an altitude of 350 feet above sea level. Six- inch pipe was carried in on camel back, the line laid and the springs deepened. The water flows by gravity down to the

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— ~—~ tI — <t - ~~ POPULAR MECHANICS

In Boats of Wicker Work, Daubed wi th Pitch, Supplies, Men and Animals Were Ferried ovér the Ti- gris during the Build- ing ; Beléw Is the Pipe- Laying Gang, Guafd- ed by Arab Soldiets Mounted on Match- less _Desert. H of ses; Ten Years Were Re- quired ‘to Lay the Line to the “Valley of Oil”

ourtesy of British Petroleum

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734 POPULAR MECHANICS seaside town and is pumped into storage tanks, reducing the cost to slightly over fiftv cents a ton. Here and there along the pipe-line route, open tanks were erected where caravans might water their camels. The spilled water around the tanks irrigated the surrounding desert land, and within a short time small bushes and grass sprang up, creating a series of oases. The Persian oil-pipe line was a much more difficult feat. The age-old caravan route leaves civilization as it crosses the first sandhill outside the port of Abadan and enters a waste of sand, wild gorges and rocky defiles that have not changed since Bagdad and Damascus were in their prime. Fierce nomads infest the occa- sional water holes, and it was necessary to keep an armed guard on hand to pro- tect each camp of pipe layers. Because of the intense heat of the desert only na- tives accustomed to the climate could do the manual labor under the broiling su: Leaving the valley, the pipe line clim| mountain ranges and dips into dee; gorges, necessitating several pumping sta tions along its 150 miles of length, an every piece of machinery, as well as the building materials, had to be tran ported on camel and mule back. In th: Valley of Oil a forest of derricks has bee: reared over the rich deposit, and a larg: boom town has sprung into existence, but the only connection with the coast con tinues to be the camel caravans and wicker boats on the Tigris, by which supplies are brought in, and the home ward-bound workers taken out. With plans under way for the develop ment of the oil fields of Mosul, in the same region, the oil center of the old world is shifting to the regions around thie Red sea and Persian gulf. Side by side with the ruins of towns that were at their best when the Old Testament was being Fo | Fad oe a ee a TS i a ea an Mules and Camels Served to Transport the Steel Pipe and Pumping-Station Machinery across Mountain Passes and the Burning Desert Sands in This Land of No Railroads

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tiene = = SS OE lived, the steel of pipe lines, gaunt wooden der- ricks, and puffing engines of pumping stations are springing up. The presence of oil be- neath the desert sands is only another evidence that some of the most forlorn wastes on earth were once, long ago, gar- den spots where life flourished. Within the period of recorded his- tory men have found little use for the bleak sand wastes, and they have lain almost unvis- ited by outsiders, save for in occasional archeolo- gist, bent on exploration of the Biblical ruins, but now that oil is being pro- duced in quantities, money and men to de- velop the country will be forthcoming in abun- dance. So far no refin- eries have been built near the wells. The output of the Persian field is pumped through the new pipe lines to Abadan, and on board of 10,000-ton oil tankers, for delivery to the refineries in South Wales. The fleets of huge tankers lie side by side in the harbor with Arab boats with their lateen sails and the gufas of the Ti- gris, an incongruous intrusion in an ancient setting. SELF-CLOSING WATER FAUCET REDUCES WASTE AND WORK POPULAR MECHANICS 735 . ) . £ ERAGE! —, Bee eee Motor-Driven Bouy Towing Life Guard to Rescue, Saving Him the Effort of Swimming through Heavy Waves LIFE BUOY DRIVEN BY MOTOR AIDS IN RESCUES For towing a live-saver to the scene of the rescue and aiding his return, an elec trically driven buoy controlled by a push button at the rear, has been tested at high tide and in heavy surf with satisfactory results, according to reports. The equip Easier to hold than the ordinary fixture of its kind, a self-closing fau- cet need be opened only part way to assure a steady stream of water and automatically shuts off the flow when released. It is easily installed and its simple AE ment is in reality a small submersible mo- torboat, capable oi considerable speed, and as it conserves the rescuer’s energy, he is fresh to meet emergencies that may arise when reaching the person in distress. FIBER FROM TROPICAL LEAF WOVEN INTO BLANKETS Said to resemble silk, a leaf fiber grown in Colombia, South America, is woven in- to blankets and clothing by the natives and also is used for fish lines. The leaves construction is in- tended to make it last a long time with- out the need of repairing. are from eight to fifteen feet long, and the fiber can be extracted by a simple process, according to reports.

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136 POPULAR MECHANICS readily handled, “sketch” reliet maps can be quick ly formed to test the student's memory. Ef- forts are made to fashion the replicas in true pro- portions. WHEN THE WAVES RUN WILD Measurement of the pressure of the waves during heavy storms, as they crashed against lighthouses, have shown that the breakers some- time drive with a force of two tons and more to the square foot. At the Bell Rock and Skerry- vore lighthouses, Eng- land, wave pressures of three tons a square foot have been recordedg-aud at Dunbar, a storm a few years ago piled water against the lighthous®@ in blows that registered Modeling Relief Map of California in Sand; Lakes, Mountains, Valleys, Rail- road Lines and Other Features Are Plainly Jndicated MAKING RELIEF MAPS IN SAND AIDS STUDY OF GEOGRAPHY Students in a San Jose, Calif., school make use of a sandpile in the study of geography by molding material into model maps of their native state and other areas. [Important topographical features are eas- ily represented, and since the sand is so three and three-fourths tons to the square foot. On one occasion G@uring a gale on the Bay of Biscay, a block of stone, weighing thirty-six tons, was lifted by the waves and hurled over a break- water. At Wick Bay, where a breakwater could not be constructed, a concrete block, weighing 1,000 tons, was laid down and secured with iron bars. The waves dis- lodged the huge block, easily snapping the bars as though they had been strings. IS SUN BEGINNING TO DIE, In 1922, when the sun failed to deliver its annual contribution of heat to the world, astronomers prepared for a series of sunspot years. In that year the sun fell four per cent short of its average dis- tribution of energy, but, more important still, it has not returned to normal in the three vears that have elapsed since. The last few months have been marked by un- usual weather disturbances due to sun- spot activity, and the star gazers explain that the cause lies in the rare combination of a maximum of sunspots with abnormal tidal pulls, the two together affecting weather on the earth so seriously as to in- terfere with crop growing. Such a marked diminution in the heat cast out by the flaming gases of the sun is temporarily ASTRONOMERS WONDER serious, but does not necessarily mean that the sun has begun to die. The life of a star is estimated at some 30,000 bil- lion years, so the sun undoubtedly has a very long life before it. Observation of the sun’s corona of flaming gases during recent eclipses has convinced astronomers that the other side of the sun, the hemi- sphere turned away from the earth, is al- ways hotter, with bigger streamers of fire, than the face we see. As the sun revolves, the pennants of flame move across its face, the bigger ones always keeping opposite the earth. As cyclonic storms sweep across the sun’s surface, these flaming columns of burning hydrogen and other gases tower 150,000 miles or more out in- to space.

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~ —~ = s ' POPULAR MECHANICS 7 FOUR DIAGRAMS OF THE SUN AT INTERVAI OF AXIAL ROTATION, THE PREPONDERANCE HEMISPHERE TURNED AWAY THE EARTH COMPARED IN SIZE VIT THE Hydrogen Flames at Different Stages, Showing How the Greatest Flames Are It dl Ne Always "7. ALWAYS EARTH on the Sun’s Surface, Sweeping Along in an Anti-Cyclone, and, Ab Away ve ¥ RRESPECTIV i= Drawings of ‘ e IN THE carth

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138 POPULAR MECHANICS X-RAYS TEST GLASs AND FIND BUTTONS Aside from their use | the medical professi X-rays have been ada; ed to service in vari industrial activities. O of the most recent these is in searching { buttons and other so! materials in piles of ra which are to be grou up for making pape The rags are passe along endless bands mo ing over an X-ray tub: If buttons, hooks, ey « or other pieces that m Persons Crossing Footpath between Lakes Appear to Be Wading Due to tlevation of Upper Pond over Lower One DAM BETWEEN LAKES CAUSES ILLUSION OF WADING Two lakes, one set about three feet lower than the other and with stepping stones between them, cause a curious illu- sion in an English park. To ,persons standing at the upper end of the higher lake, those walking below the dam that separates the two, seem to be wading in the water above their knees. In reality, they are on the dry stones, the width of the path being so slight that the two lakes give the impression of being a continu- ous body of water. SAFETY ON AMERICAN RAILWAYS DOUBLED IN TEN YEARS Travel on American railroads is twice as safe as it was ten years ago, according to figures gathered by the American mu- seum of safety. In 1914, one passenger was killed for every 6,620,000 locomotive- miles traveled and one was injured for every 116,000 miles, but in 1924, the lines operated 11,250,000 locomotive-miles to each passenger killed and 287,000 miles before one was hurt. Similar records have been made in regard to railroad employes, the reports show. In 1917, a worker em- ployed by the railways was killed in an industrial accident for every 9,120,000 man-hours of labor, while in 1924, one was killed for every 15,550,000 man-hours. For every 28,000 man-hours of work, in 1917, one employe was injured, but in 1924, only one was hurt for every 48,000 man-hours. These improving records are attributed, in part, to the influence of the Harriman safety awards. damage the pulp n chines are present, the can be seen distinctly o a screen just above the band. The ra are also employed in a large English lab oratory for testing glass of which the: mometers are made. Unsuitable glass ca be detected in an instant by the X-ra according to reports. SPARE TIRE ON LUGGAGE RACK SERVES AS BUMPER Baggage rack and spare-tire carrier a1 combined in an arrangement that has a; peared in England, and is said to be pat ticularly adapted to small cars. The whee is securely locked in place and easily r Placing Spare in Baggage Rack, and How It Acts as Bumper When Carrier Is Down moved, and when the rack is in the “dow: position, the spare projects sufficiently t form an efficient bumper. When it mounted in a vertical position, the whee is inconspicuous. @ The Bible has been published in twent three dialects of English.

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POPULAR MECHANICS 739 Airplane View of Great Pyramids at Gizeh, Showing Modern Hotel with Shaded Yards and Gardens in Fore- ground; a Smoothly Paved Road Links the Past and Present ANCIENT AND MODERN EGYPT SHOWN SIDE BY SIDE Vhile ancient Egypt gave much thought he care of the dead, the nation today 1s no means neglecting the living, as is nin the modern hotel built specially for urists at the foot of the great pyramids ir Gizeh. Within a short distance of ese venerable monuments, travelers can iovy most of the conveniences that an to-date city hotel provides, while shad- erounds and gardens are furnished for eir pleasure. A view from an airplane resents this contrast at a glance, the old vpt typified by the solemn stone tombs its kings and the new represented by hotel near by. TRAFFIC CODE FOR AIRPLANES TO SAFEGUARD SKY TRAVEL Similar in some respects to automobile- the regulations, a standard aeronautic lety code, announced recently, gives bal- ns the right of way over both dirigibles l airplanes, while dirigibles have preced- ce over planes. When aircraft meet, ey shall pass to the right as in street rathe, and when one overtakes another, it shall turn to the right in going by. Ap- proaching craft are said to be in dangerous proximity when 1,500 feet apart. In the rules for medical examinations of avia- tors, a test for “night blindness” is in cluded, and a “good family history” with reference to nervous stability is another requirement. SCREEN DOOR UP IN SECONDS WITH SPEEDY HINGE Screen doors may be hung or removed inten sec onds with a spring hinge now- being marketed. The pin connecting the part attached to house and door is inserted by the tap of a hammer or removed by a slight upward thrust. A: other feature is that the springs are co\ ered and are not d placed when the holding pin is removed. The hinge can be used on either side of the door.

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740 FIGUREHEADS FROM OLD SHIPS VALUED AS DECORATIONS Among the most highly prized of the 1 . ] . 7 ‘ T ’ relics saved trom old ships of Nelson’s day Measuring Figurehead of First Duke of We'lington, a Typical Decoration Such as Adorned Old Ships and from other vessels, are the carefully carved oak figureheads which adorned the prows. A London shipbreaker has col- lected a number of these specimens, and after they are repaired and redecorated, they are in great demand as antiques. A giant figurehead of the first Duke of Wel- lington, shown in the accompanying illus- tration, is typical of the carvings which were lavished on the ships of olden days. POPULAR MECHANICS SEEK FOR RUBBER SUBSTITUT! IN KIDNEY BEANS Chemists are reported to have foun way to make synthetic rubber from t soybean and now an English expert clai that the ordinary garden variety of kid: bean may be used for a similar purpo The beans are partly dried after gath: ing, broken up and then treated with var ous chemical solutions until they are 1 duced to a substance that has the appea ance of rubber and can be vulcanized the same way as the true product, it said. To further cheapen the substitut experiments are being made to cross-fe: tilize the beans in order to make the plant more prolific as well as to produce larg seeds with a minimum of leaf and development. STé REAR SEARCHLIGHT ON TRAIN ILLUMINATES SCENERY Beauties of the scenery along the rig! of way of a western railroad are not | when darkness falls, for a huge searc light, installed on the rear of passenge: trains, permits a clear view of streams and even mountains at a consid erable distance from the observation plat form. The light is supplied with curre: direct from the railway system, which electrified, and is focused to illuminate wide area. It can be swung about wit little difficulty. In emergencies, the lig can be used with a red disk as a warnins to trains behind. woot b i) ae we ee , mt i$ J i Ps we . ee ——— eaiites — | — ‘ LYMPIAN) Enjoying Scenery from Observation Platform after Darkness; Powerful Electric Searchlight, Supplied with Current from the Train System, Gives Passengers a Chance to See Wayside Beauties at Night

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t+ nt

he Owl ings Resemble the Eyes of an red that, instead of a utterfly life representing a short ral amazing conclusions. POPULAR MECHANICS 741 Seagoing Butterflies Amaze Scientists

Butterfly, So-Called cause, When Turned Upside wn, the Spots beneath Its It Comes from Madagascar time - honore¢ is well on the to extinction before research of modern 1ence, which has discov- \nother nonym 1 | idle existence, it really is de- oted to remarkably long-distance travel- ng. G. Fe Felt, state entomologist of ew York, and other scientists who have ‘cently made a study of the movements ] nd distribution of various butterfly types roughout the world, have reached sev- They found it throughout the East Indies, from ingapore to Thursday island, the large ypical moths which spend their days thering nectar from the flowers are ad- ted to long night journeys. Ships an- hored as much as twenty miles off shore re visited by swarms of the brilliantly red insects, attracted from shore by e gleaming electric lights. Che flights frequently occur during dead ms, disposing of the belief that the itterflies might have been blown out to i, as often happens with birds and vari- is kinds of insects. Large butterflies | dragon flies are both listed among the ip visitors. The latter have been en- untered 900 miles west of Australia, and 0 miles from the Cocos or Keeling isles, barren waste on which they could not ive existed. From their types it was msidered probable that they had flown | the way trom Sumatra.

The Largest Butterfly in the World, Together with Specimens of the Smallest for Comparison, and, in the Center, Collector Photograph ing Some of the Valuable Specimens Native American types of dragon flies have not infre- quently been collected in the Hawaiian islands, 2,000 miles from the shore of California, and the big Monarch butterfly also has been found in the same place. This creature is perhaps the greatest of the insect trav- elers, for it annually migrates, in a series of varying stages, from Florida to the Arctic circle and back again. The Arctic offers a paradise for flower-feeding in- sects during its brief summer, for when the snow goes, myriads of brilliant flowers spring up in its place. The Red Admiral, another famous trav- eling butterfly, is a world-wide cosmopoli- tan. Entomologists have encountered it in virtually every section of the globe. Even such fragile flyers as the lace- winged flies and plume moths, about as substantially built as thistledown, regu- larly visit lighthouses twenty miles or more at sea. Many of them may drift along before favorable winds, but a sur- prising proportion of the journey s checked that either calms or unfavorable winds would eliminate this factor. show Ss TROUT EGGS SHIPPED TO JAPAN Japanese streams are to be stocked with brook trout from Canada if experiments now under way prove successful. <A ship- ment of 50,000 eggs was sent from hatch eries at Vancouver at the request of the, British ambassador at Tokyo.

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Newspaper Rolled to Form Horn for Novel Stringed Instrument Played like a Cello NEWSPAPER SERVES AS HORN ON STRINGED INSTRUMENT Tones produced by a novel stringed in- strument devised by an eastern musician are said to be amplified and improved simply by rolling a newspaper into the shape of a horn and inserting it in an opening near the base of the piece. The paper acts as a vibrating diaphragm, as in radio loud speakers of that material, and there are no metallic sounds as is some- times the case when horns of metal are used. The instrument is essentially like a violin. POPULAR MECHANICS FIRE HOSE WRITHES LIKE SNAK?: DURING STRENGTH TESTS Fire alarms sound, engines, trucks a ladders speed to the scene of the flam long lines of hose are laid with almost i: credible swiftness and streams of wat are soon shooting at tremendous pressu upon the blaze. This happens many tim: every day, and failures in equipment, pa ticularly hose, are rare in up-to-date cd: partments. This is partly due to the rig system of strength tests to which the go ernment subjects fire hose to meet the r: quirements of the bureau of standard One of the instruments used for the tria is a hydraulic pump. A length of hose attached, and by progressive steps, t! pressure is raised from ten to 400 poun: to the square inch. The high point maintained for ten minutes, after whi careful measurements are taken to dete: mine what effect the treatment has had o: the hose. The pressure may then be in creased to more than 500 pounds, causin the length to squirm and coil like a snak« Minute inspections are made for leal and sweating. There is on record at th: bureau, where thousands of feet of hos: are tested every year, only one instance of a length of hose bursting under a pre sure of 550 pounds to the square inc! Such failures are exceptions to the rule for most manufacturers have learned thx secrets of making a strong, durable prod uct. One of the regulations of the bureau is that the hose shall be flexible and easi! coiled. For instance, a fifty-foot lengt! J two and one-half inches in diameter, must coil withi a circle of a diameter not greater than twenty-eight y/ inches. Proportionate limits Testing Fire Hose at Bureau of Standards; Pressure Is Accurately Measured and Lengths Closely Examined for Signs of Strain are fixed for hose of different sizes and kinds. By chemi

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nce POPULAR MECHANICS 743 tests, the scientists determine whether not sufficient rubber has been used he lining, at least seventy-five per cent olume being a requirement. The to- ulphur content must not be more than t per cent of the to- WORLD OF MOSS AND PLANTS SHOWS FLORIST’S SKILL One of the features of the grounds at the national military home’ at Leaven- weight of the rub- as compounded, and material must be free m oil substitutes and iimed rubber. Tests also made to deter- ne the degree of ad- ion between the back- and jacket; couplings re carefully examined to their quality, reads and gaskets, and e bureau requires that ich length averaging itv feet must be pro- ded with couplings ide of an alloy of cop- er, tin, zine and lead, ch in properly pre- ribed proportions. In ‘sting single-jacketed ose, one requirement is hat it must not rise from e surface on which it rests to a greater dis- tance than four inches under a water pres- ure of 400 pounds to the square inch. RUBBER HEELS ON HORSESHOES PREVENT SLIPPING lo lighten the horse’s task on slippery treets, shoes that have thick rubber heels, ith suction cups affording a firm grip mn the pavement, are said to. have proved practical and humane. They are so ad- usted that most of the animal’s weight is carried on the heel, reducing the wear on the toe calks, and there is less dan- & rer of causing ic) vounds to the : orse’s foot, it is declared. There re only two calks to change on each hoe, instead of our or more on ther types, and vhen the shoe ears down too ow to give a sharp support on ice, it is till suitable for several weeks’ service as a ummer shoe, the manufacturers assert. } @ According to a British naturalist, the thrush can sing for sixteen hours atatime. World in Moss and Shrubs Must Be Kept Carefully Trimmed and Trained to Maintain Areas in Proportion worth, Kans., is a model of the world in moss and live plants arranged over a framework of wooden slats and wire. One species of plant forms the hemispheres and another, of lighter shade, represents the oceans. The interior of the globe is filled with moss to afford a bed for the roots of the outside growths. Consider- able skill was required to fashion the sphere accurately and substantially, and correct selection of plants Was necessary to assure proper growth for keeping the right proportions of land and water: areas. ONLY FEW FARMS HAVE RADIO CENSUS SURVEY SHOWS According to a recent survey of twenty states by the census bureau, out of the 1,853,869 farms in those districts, onl) 109,992, or less than six per cent, are equipped with radio sets. Of the twenty listed, Illinois made the highest showing reporting a total of 27,434 sets, while Kan- sas was second with 13,189 sets. In ey tember, 1925, the department of agricul- ture reported that little more than eight per cent of all the nation’s 6,372,263 farms were equipped with radio receivers, and the more recent tabulation indicates that there is still a wide market for wireless ap paratus among farmers.

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744 GAS DRILLS FOR POLICEMEN AID IN BANDIT WAR Members of the San Francisco police department are given weekly drills in the use of and masks of gas protect ive Policeman Wearing Mask of the Type San Francisco Department Has Adopted ior War on Bandits to help them in this mode of attack against criminals. Army officers from the Pre- sidio near by give the instruction, the po- licemen being taught how to adjust their masks quickly and securely and how to use tear-gas and other kinds of bombs. TASK OF MENDING OCEAN CABLE REQUIRES SKILL AND NERVE When the transatlantic cable from Cape Cod to Brest, France, breaks, the repair POPULAR MECHANICS ship “Edouard Jeramec,” a marine oddit among vessels with huge tanks that h 250 miles of cable below decks, is d patched to the scene and the work ; mending the break which has been locat« by delicate instruments, is begun. Som times the strands have parted in mid ocean. Down go grappling hooks weight ed so that they can be sunk to a depth « three miles if necessary. Buoys are poste to mark the ends of the cable when it found, and powerful winches fore and ai are ready to raise or reel out the heay wire. Severe winds and raging seas must be disregarded and even night does no stop the work, for the scene is illuminate: by powerful lamps. Often, before th cable has been pulled to the deck, it break again and slides back to the mud and slime of the ocean floor. Last June, just as th: crew of the “Jeramec” was finishing th: lastesplice on the broken cable, off Cap: Hatteras, a terrific storm broke, throwing the ship on her beam ends. The wireless aerial was sent spinning to leeward wher: it became tangled. in the propellers and the vessel’s topmasts were torn off. But the damage was mended by the eight) five sailors aboard, and the ship returned to complete the task of fixing the cable BOOK CARNIVAL HELD IN RUSSIA TO STIMULATE EDUCATION In the interest of better school facilities for the citizens, a book carnival held i: Moscow, Russia, featured a parade in which lines of marchers, carrying placard and banners, endeavored to spread their message for more education. The affair, staged at a time when the streets were crowded, attracted wide attention. a! hs ES eC | A HH , anerert veces ‘ BC 2 4 « 2 ” a a > , A saa ” bs 4s ’ > = eZ * ey. - "6 hae How the Rissians Support Better Education, a Book Parade at Moscow during Literary Carnival

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POPULAR MECHANICS -~? P= or | ~ ; a» a oa ae ee ae ah Completely Insulated House of Seven Rooms in Which Gypsum Product Was Used in Walls and Roof, While Many Novel Ideas Were Worked Out in Construction of Interior New Methods Quickly Pay, While Fuel Bill for Uninsulated Home in Twenty-Five Years Equals Cost of House N insulated house will more than pay 4 the cost of the insulation through uel saved in the first three years, accord- ng to a recent report of the United States ureau of industrial research. Heat, the eport explains, leaks through lumber, rick and stone just as it does through lass, though not so fast, but with proper nsulation, fully thirty, and probably fifty er cent, of the nation’s fuel bill can be ved. \ seven-room house, heated by a tiny as boiler designed for warming garages r heating hot water for apartments, has ttracted thousands to a new subdivision t the edge of one of Chicago’s forest pre- erves, just outside the city limits, during e past winter. Here, where tempera- ires are commonly several degrees lower han in the crowded city districts, unusual eating records have been made. The in- ulation used, a new gypsum compound, s the outstanding feature, but the interior of the house presents a number of inter- esting departures from the usual build- ing mode. The insulation, fire, sound and heat-proof, is poured into the walls and roof like cement, and completely fills the space between the studding and rafter making a solid wall from the shingles on the outside to the wall paint inside. The two-by-fours used for the frame construc tion actually measure three and_ five eighths inches, so the gypsum has a cor- responding thickness. Maintaining, by means of automatic thermostatic controls, a constant tempera ture of seventy degrees from 4:00 a.m. to 10:00 p.m. and sixty degrees during the night, and heating with gas at seventy-five cents a thousand cubic feet, the fuel cost from October 1 to February 1 totaled $110, with an estimated cost for the entire win ter of $160. The insulation proved so uccessful that snow remained on the root for days, until melted by the sun, while heat leaking through the roofs had re moved it from all the neighboring homes The insulating material, called insulex comes in bags, like cement, and is mixed

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746 POPULAR Arched Openings with No Casing, Top; Right, Pour- ing the Insulating Material, and, Below, the Specially Built Doors and Hand- Wrought Hinges with water. Owing to the presence of other chemicals with the gypsum, it expands in a few minutes after mixing to several times its original bulk. In this condition it is poured down inside the walls and allowed to set, hardening into a spongelike and por- ous mass, filled with millions of tiny air cells. The frame of the house was covered on the outside with plain matched sheath- ing, over which the shingles, dipped in pale-gray stain, were nailed. The inside walls, instead of being plastered, were cov- ered with a gypsum wallboard, and after both sheathing and wallboarding were in place, the insulation was poured. The space between the roof rafters was treated in the same way, and in addition two inches of insulation was placed beneath the lower floor, in order that the floor might be warm while the basement, which extends under the entire house, would remain cool. Gas engineers estimated that to heat an uninsulated house of the same size, twen- ty-nine by forty feet, with five rooms downstairs and two upstairs, would re- quire a boiler with a rating of 1,150 feet, and a direct radiation capacity of 575 Figuring on the insulation, how ever, they guaranteed that a small garage or hot-water heater, with a rating of only 425 feet and a direct radiation capacity of 213 feet, would keep the house at a constant temperature of seventy degrees when the weather outside reached twenty below zero, about the lowest sub-zero temperature ever experienced in Chi- cago suburbs. were placed upstairs and down, with bulbs outside the house, in the living one of the second-floor bed- feet. room, MECHANICS in Recording thermometers rooms and in the attic space under the A recording chart was hooked to the heater, to show when the gas was turned off and on by the thermostat reg- ulator, a thermometer was added to give the temperature of the water in the heat- ing pipes, and other thermometers in- stalled in the dining room at the floor and ceiling levels and midway be- roof. tween. The record charts made many interesting disclosures. In com puting the heating required, the engi- neers based their cal- culations on a water temperature of 180 degrees in the pipes, since most hot-water heating plants work at from 180 to 200 degrees to maintain seventy -degree tem- peratures in the

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\_. =e POPULAR MECHANICS 747 View of the Living Room with Arch to the Tile-Floored Dining Room Beyond; Note the Rough-Painted Walls, Absence of Wooden Trim, and Sense of Space Because of the Broad Arch ooms. Actually, the charts disclosed, it as only necessary to heat the water to 140 degrees on a day when the tempera- ture outside was sixteen below zero, while ith temperatures down to freezing, 110 legrees in the water pipes kept the house it seventy. luring which it was sixteen below zero uutside, the recording chart on gas con- In the twenty-four hours umption showed that the gas was turned ff for a total of seven and a half hours. ’n another winter day, when the outside hermometer chart showed temperatures uctuating between thirty-five above zero nd one degree above, the gas-consump- tion record showed no gas consumed for ve hours during the day and six hours at ight, or a total of eleven out of twenty- our hours when no fuel was needed to ‘eep the temperature constant. The thermometers at floor and ceiling n the dining room never recorded a creater variation than eight degrees, and he average was four degrees, as compared vith differences of sixteen to eighteen de- grees in uninsulated homes. Humidity records, taken at intervals, showed a very igh percentage, never less than forty and irequently as high as forty-nine per cent, indicating that the even distribution of heat and the fairly low temperature need- ed in the radiators did not dry the air out as in the ordinary steam or hot-water heated house. The cost of the insulation was $435, and approximately the same amount was saved at the start on the cost of the heating plant, since less than half the usual boiler and radiator capacity was required. Some of the unusual methods of finish- ing the interior are as interesting as the results of insulation. Wallboard was used instead of plastering, a gypsum paint re- placed wallpaper, interior trim was prac- tically eliminated, and by using archways, most of the downstairs doors were di pensed with. Even the closet doors, with the exception of those in front of the linen and storage closets, were eliminated, and arched openings, with attractive cur- tains, took their place, giving a sense of greater space and connecting rooms. The saving on doors and interior wood- work, including the expense of painting and varnishing, was estimated at some $1,700. Instead of the usual baseboard, a very narrow molding was placed at the bottom of the walls. Window casing was

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748 POPULAR MECHANICS replaced by a half-inch half-round mold- ing, such as is used on window screens to cover the edge of the wire, and the mold was then painted over with a special wall finish, kraftex, as was done with the pic- ture mold just below the ceiling, giving both the appearance of being part of the wall, instead of being nailed on as an added accessory. The arched openings were formed quite simply by cutting the wallboard to the shape of the arch, placing chicken netting across the top for reinforcing, a form be- low it, and pouring the insulating cement in from above. The usual cracks around the windows were avoided by cutting the wallboard to project over the window frame, and nailing it in place, while the insulating filling poured into the wall formed a solid bond with the frame. The house cost $13,000, at the relatively high prices for labor and material in Chi- cago. The cost also included a number of expensive time and labor savers not found in the average small home. A fire- place and outside chimney costing more than $600 could have been built much more cheaply, or eliminated entirely. The built-in electric refrigerator cost $385. Rubber tiles, a half inch thick, on the kitchen floor cost $9 a yard. The dining room was floored with tiles, but here th: cost was no more than a good grade oj oak flooring and a good carpet would have been. Fifteen hundred dollars was spent for bathroom fittings, including white tile almost to the ceiling line. An expensive type of hot-water heater was installed, and likewise a garbage incinerator. The gray shingles on the walls and the green shingles on the roof were selected wide stock, all hand-dipped. The lighting fix- tures downstairs were specially designed and made by hand by a worker in wrought iron. The doors, such as were used, were designed from a model seen in a new movie theater, and built to order. Instead of having panels, they are built of solid oak planks, two inches thick and six inches wide, running lengthwise of the door, and at the joint there are beveled grooves ap proximately three-eighths of an inch wide and nearly as deep. The hinges were de- signed and made to order of ornamental hand-wrought iron, extending nearly half way across the doors. The price of $13,000 also included complete built-in kitchen- cabinet equipment. It is because of its heating record, how- ever, that the house attracted engineers Photos Courtesy H. S. Ashenhurst Part of the Built-In Kitchen Equipment, Which Includes Extensive Cabinets, Drawers and Other Receptacles; the Floor Is Made of Rubber Tiles, Half an Inch in Thickness

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POPULAR MECHANICS 749 - The Tile-Floored Dining Room Is Likewise a Livable Sun Parlor, Made So by the Small Space Taken by the Gate-Legged Dining Table, Which Seats Eight When Raised nd architects from many cities, as well as housands of home owners—more than 10,000 of the latter passed through it in hree weeks. The gas engineers estimated that it would have cost $350 to heat the ouse uninsulated, more than twice the expense this winter. The fuel saving made t possible to use gas, requiring no,trouble, aking no dirt, and leaving no ashes, at TREES ARE WATERED BY TUBE TO MEASURE THIRST Some 700 young trees are being used a series of experiments at the Rocky ountain forest station on Mount Mani- u, Colo., to study their rate of rowth; how much water they require, nd other features. They are being grown n iron cans with the soil surface covered ith paraffin to prevent evaporation of the ater which is poured in through a small lass tube. By weighing, the amount of oss through the leaves of the tree is de- ermined. The observers have found that robably less than one per cent of the ater is taken up into the permanent tructure of the trees, the rest being breathed out” in the form of vapor. Five ecimens, shown in the illustration, each onsumed about a gill of water during a eason’s growth at the end of two years. he tests will cover a period of four years. a price less than coal would have cost in the same house without insulation Be- cause of the absence of fuel bins and dirt, the big basement, with its cement floor waxed, has been used for community dances and other functions, the small boiler, and the water heater and garbage incinerator occupying only a limited space in one corner. About forty plants of the different speci- mens will be saved for the final observa tions. The others are pulled up and pho tographed from time to time \ back- _ a 5 * 4 ~_ete. ee Es A a 2 Young Trees Growing in Iron Cans at Experiment Sta- tion; Water Tubes Are Seen above Rims 1 calculations as to the amount the h ground of plotting paper permits quick trees ave grown. q From t o dav coaches combined, t first palace sleeping car was built in 18

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750 = Kite, Seed Containers in Forester’s Left Hand, and Reel Attached to Fender SOWING TREE SEEDS FROM KITE SHOWS HOW NATURE PLANTS Nature’s own method of sowing was adopted by foresters in Washington re- cently when they scattered the winged seeds of the Douglas fir from a kite flown to a height of about 175 feet. Squares of white canvas were spread on the ground at intervals to leeward, up to about 1,600 feet distance from the kite. By counting the seeds that fell upon the canvas, it was estimated that approximately 80,000 seeds were distributed to the acre. The velocity of the wind was measured for the experi- ments by an instrument carried on the automobile, which was also provided with a reel for controlling the kite. A day when a moderate breeze was blowing was chosen for the test. The seeds were car- ried in small receptacles so arranged as to allow the contents to fall at a POPULAR MECHANICS HUMAN VOICE LIKE ORGAN PIPE WITH VIBRATING REED One reason why great voices are rare is that few persons have the combination of physical characteristics necessary for the production of exceptional tones, according to a British doctor. The human instru- ment somewhat resembles an organ pipe Instead of a vibrating reed, there are vo- cal cords, while the larynx and the bron- chial system below it correspond to the pipes. The throat, mouth and nasal cav- ities form the resonators, and by altera- tions in their shape and size, certain parts of the fundamental tones produced in the larynx are emphasized. Slight differences in the structure of the various parts have a profound effect on the voice. Varia- tions in the length of the vocal cords determine the pitch; the shorter they are, the higher are the tones. For this rea son women’s voices are higher than men’s as their vocal cords have an average length of only about eleven and a half mil- limeters, while the average length in men is fifteen and a half. The range of the voice depends to a large extent upon the tension which can be exerted upon the cords. Except in celebrated singers, the range only in rare cases has exceeded two and one-half octaves, which, of course, lie in different parts of the musical scale for different voices. STOKER FOR SMALL FURNACES SAVES COAL AND SMOKE Adapted to heating plants no larger than those used in residences as well as larger units, an automatic coal stoker now on the market eliminates practically all smoke, reduces soot and saves fuel. It is operated by a small electric motor which fairly even rate. turns a feeder shaft, sup- plying coal from a hopper into a retort within the firebox. A fan supplies air, aiding in the combus- tion of gases and the thor- ough burning of the coal The stoker is regulated so that it automatically stops, | ae | Cross Section Showing Worm-Screw Feed, Hopper and Interior of Firebox, and Inset of Typical Installation with Small Furnace and starts again when more fuel is needed. It may be installed at the front or at the side of the fur nace and requires practically no attention save refilling the hopper. Parts exposed to the heat are cooled by the tan, and the coal feed can be ad- justed to different rates.

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Wwe er Ww all POPULAR MECHANICS 751 The Start of a Balloon Tire; These African Women Are the Backbone of the Rubber Industry in That Con- tinent, for They Do the Actual Work of Tapping Trees and Gathering the Sap Rubber Farm to Cut Cost of Tires World’s Need for Lower Prices Brings Life to Liberia, Founded by American Ex-Slaves More Than Hundred Years Ago TS world-wide search for more and cheaper rubber for automobile tires has ended the century-long nap of Liberia, the hermit republic on the west coast of° \frica, where English is spoken as the ficial language and where towns are named for American cities. Liberia was sunded in 1822 by an American who took few freed slaves back to the African oast, and has been recognized as a repub- ic since 1848, but it remained for the de- mand for cheap rubber to give it a place n the business world. An American tire maker, seeking some scape from the high prices fixed by the British rubber monopoly, found ideal rub- er land in the hermit tepublic and has leased and started development on a mil- on acres, capable of growing 100,000,000 rees and, within the next decade, sup- ving nearly one-third of the world’s rubber. Fifty thousand acres will be planted during the first half of 1926, and t similar number during the last half. The rest of the million acres .will be planted is fast as the land can be cleared, roads built and workers gathered. he task is aggravated because of the hackward condition of the country. Since he republic first was founded and its capi- tal, Monrovia, named for President Mon- roe, the country has been content to sleep. Part of the coast region, to a depth of fifty or sixty miles, has been partly cleared, particularly along navigable streams. There are, however, no roads, except for one of fifty miles out of Monrovia and an- other five miles long. There are no rail ways, telegraph, steamers on the rivers, nor any modern improvements. Before the rubber land can be planted, it will be necessary to build roads and railways, telegraph lines and telephone systems, and import tools and machinery. The rubber development is expected eventually to produce much wealth, and therefore taxes, which in turn will provide money for the development of the rest of the country. One reason for Liberia's backward condition is the inability of the vovernment to collect taxes from the na- tives, and this, in turn, is due to the lack of progress which has left the natives poor Liberia has always been closely related to American wavs because most of the officials either were born in or are de scended from negroes born in the United States. From time to time movements have been launched for the migration of large numbers of American negroes to the black republic, but each time they failed, largely because the prospect of living in

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752 POPULAR MECHANICS tion which now has been acquired by the new American company as a nursery and experimental station. The development of the million-acre lease is expected to take a number of years, but the first trees, planted this spring, will be ready to vield rubber within five or six years. Rubber trees are plant- ed in open rows, like fruit trees, and, if desired, a plantation can be made to yield during its early years by growing other crops between the rows. Not much relief can be expected from the new rubber plantations for several years, but the fact that American inter- ests are getting into the field will prob- ably help stabilize prices. During the past year the unusually high price has led to smuggling of raw rubber on a large scale in the Dutch East Indies, where op- erations of —————— Boiling a Lot of Sap } the Tree; the Seed- lings, enter, and } Below, Gathering the Sap Top, Small beside Plantin such an unde- veloped coun- try did not ap- peal. The new rubber indus- try, which will the smugglers have been as extensive and picturesque as those of the rum runners off the Amer- ican coast. Native boats plying be- tweenthe islands were used to run the rubber cargoes past the customs. employ all na- — tive labor at the start, is expected, in residence in Liberia The better class in Monrovia live in houses modeled after southern homes in America, read American books and papers, speak English, adopt American and currency, but only a few make attractive. time, to more customs miles back from the coast such innovations are vir- tually unknown, except along the navi- gable rivers, and these, owing to a high plateau in the interior, are not navigable very far. The few backwoods settlements rejoice in such incongruous names as New York, Philadelphia, Bunker Hill and Hart- ford, but outside of them the influence of Monrovia is little felt, and, in fact, the vast part of the country has never plored or mapped. The explorers who have penetrated parts of the jungles have found more than twenty varieties of wild rubber trees and vines growing there, and, since 1904, rub- ber has formed a portion of the exports, a British company having started a pianta- been ex-

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1e id re of m Le a in Sy st 1S. POPULAR MECHANICS 753 Where Light from the Stars Is Bright Enough for Races; Ski Slides over Snowbanks at Swiss Resort Give Devotees of the Sport New Thrills at Night MOUNTAIN SKI RACES AT NIGHT NOVEL WINTER SPORT Night-time ski races furnish enthusiasts Adelboden, Switzerland, amusement hen the skies are clear. Light from the stars alone is said to be sufficient to guide e racers and they are spared the glare of the sun. LENGTH OF GIRAFFE’S NECK FIXES ANIMAL’S VALUE Giraffes are sold by the neck and hippo- potami by the pound, annual stock taking ranging from $700 to $900. The rhinocer- oses are valued next to the prize elephant, being worth about $4,500. All the animals at the zoo were estimated to be worth about $125,000. DOG TEAM CARVED FROM ICE AS WINTER STATUE Occupying a prominent position in a Quebec park last winter, was a dog-team- and-driver statue carved from ice. The group was shown as though traveling and attracted wide attention because of its lifelike execution. of the animals at the london zoo has revealed. sa Giraffes generally are orth about $2,500. The eneth of the neck is a determining factor be- cause of the difficulties in shipping. The largest iippopotamus at the London zoo is valued at 4,000, while the most valuable animal in the entire collection is an ele- phant which carries chil- — dren on its back. Its _— vorth is placed at $5,000. Lions average about $250 each, depending upon their size, age and dis- o osition. Since tigers are . a lore difficult to capture, they bring higher prices, Dog Team, Driver and Sled Carved in Ice for Winter Display

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Blowing Three Million Bubbles a Second Courtesy Artist’s Drawing of Bubble Waterfail, Exposing Framework, Motors and Blowers, Canvas Backing and Cross Section of Bubble Cascades; Rocks Were Formed from Wire, Paper and Glue 754

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for Mimic Waterfall on Theater Stage —_—— BUBBLES ., SOAP AND WATER } | Balaban & Katz ross At the Foot of the Soapy Cataract, Dancers Interpreted a Story Climaxed by the Man Plunging into the Bubvles and Disappearing; Inset Shows Details of Construction

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756 POPULAR MECHANICS . oy \ ¥o4 \4 Ot oe ’ fr? a VEZ ¥ Z zs A German “Hercules” Demonstrates His Strength, Supporting Track and Two Motorcycle Riders While Lying on His Back; Cycles Are Connected to Center as Pivot to Aid in Balancing MAN HOLDS TRACK AND RIDERS IN STRENGTH TEST Supporting a wooden track upon which two motorcycle riders are racing; is one of the feats performed by a German strong man. Besides holding the weight, he must help balance the load under the shifting position of the cyclists and the test is one of considerable duration, as the track must be held while the riders are getting up the speed of their machines. DESK CLAMP FOR TYPEWRITER REDUCES NOISE AND WEAR Features of a shock-absorber and si- lencer are combined in a clamp to hold the It is easily in- typewriter to the desk. stalled and adjusted, and is so constructed that the machine is held at any angle re- quired by typewriter desks with disap- pearing tops. It al- so permits the op- erator to move the machine forward when using it if desired. By decreasing the jar on working parts, it is intended to prolong the life of the typewriter, reduce repair bills and spare the stenographer unnecessary fatigue. It is manufactured for different kinds of standard machines, and special clamps may be had for those with extra-wide car- riages, billing devices and other machines. ARMORPLATED INDIAN RHINOS BAGGED BY ROOSEVELTS Specimens of the rare armorplated In- dian rhinoceros, as well as royal Bengal tigers and other big game, have been ob- tained by Theodore and Kermit Roosevelt on their hunting expedition into central Asia for the Field Museum of natural his- tory. They were granted permission from Indian and British authorities to enter some of the vast game preserves main- tained by the rajahs after they had been successful in bagging specimens of tne ovis poli and other rare game in the Pa- mir districts. It was in India that they found the armorplated rhinos. Some ten months were spent in the wildest and least explored regions of central Asia. At times, the hunters reached altitudes of 15,000 and 18,000 feet. @ Instead of shaking hands, the Chinese wag their clenched fists.

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i‘. It of DS S. ese POPULAR MECHANICS 757 STAGGERED CITY-TRAFFIC PLAN TO REDUCE DISEASE ) reduce the spread of colds and other municable ailments in New York city, an of “staggering” the subway sched- was proposed to relieve congestion. scheme involved different closing opening hours for schools, places business and other institutions so t the peak passenger load might be tributed over a greater period of e and keep individuals from such e contact in the cars. The plan ; considered advisable especially iuse of the menace from smoke, isually heavy at the time, on count of the hard-coal shortage. imilar arrangement was worked during an influenza epidemic. LETTERS WRITTEN ON SKY WITH SEARCHLIGHT Using a combination reflecting and projecting apparatus, a California in- ventor has developed a new form of sky riting. Instead of employing smoke from airplane, he utilizes clouds as a sort of reen upon which he throws letters from pow erful arc light. The characters are Model of Los Angeles Tennis Club, Showing Arrange- ment of Courts and Inclosure for Tournaments produced by the shape of the carbon. The trument can be focused to points at TENNIS COURTS AND CLUBHOUSE considerable BUILT FROM MODEL distance and concentrates the light to in- sure visibility. As an aid to builders of a tennis club costing more than $200,000 in Los Ange- les, a “working model’ of the proposed grounds, including the courts, clubhouse and swimming pool, was constructed. It was carefully planned to proper scale. One of the features of the project is a spe- cial court for tournament matches. It has bleachers for spectators, the seats be- ing arranged to afford unobstructed view of the games from all points. TAKE SNAPSHOTS UNDER WATER TO STUDY SHIPS By taking under-water pictures of model ships in experimental tanks, designers are able to study the hulls as they would per- form under actual conditions of use, as to rolling and other motions. This is made possible by a special method of making snapshots, developed by a Japanese. Light is furnished by exploding a “thread” of mercury under water. The material is in- closed in a narrow glass tube and sealed. Application of an electric current causes the glass to burst with light sufficiently in tense to register on the negative of the ouds from Combination Reflector and Searchlight submerged camera. inset Shows Letter “L” as It Appears Projected on (

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758 POPULAR MECHANICS — rn— ting channels for vehi going at high speed a others for slower spee Side entrances would he furnished a mile apart for entering or leaving. The engineer suggests that crossing streets be placed at different levels. DOG TEAMS TAKE ENGINES’ PLACE IN ALASKA In the palmy days of Nome, Alaska, when mi! lions in gold were being mined near by, a railroad ninety miles long, w built to serve the dis- ' P trict. Subsequently, with Big Log Split after ——s hed ee Showing Instrument the decline in gold pro- duction, the rolling stock GUN FOR SPLITTING CORDWOOD was sold and the rails were about to be SAVES TIME AND LABOR torn up and disposed of when a group « public-spirited men intervened. Savin Logs as large as ten feet in diameter are ___ the line led to the use of dog teams inste: quickly split into cordwood size with a of engines for hauling freight. Six or special gun consisting of a steel cylinder, eight huskies can pull a quarter of a ton eighteen inches long and five-eighths of forty or fifty miles a day, it is an inch across. It is tapered to a said. After dragging t! point so that it can be driven into load up steep grad the log and a small charge of the dogs climb aboard powder, which is ignited with and ride down. Th a fuse, is inserted in the territory of Alaska chamber of the gun. Driv- has acquired the ing the cylinder into the road, and it i log compresses the explo- now kept in rx sive. One gun is said to pair by the last long enough for split- territoria ting as much as 150 cords highway com of wood, and only about mission. two minutes are required t6 load and fire it. Prac- tically no danger attends the operation, it is said, and wood can be split for eight cents a cord. “ ath SIDEWALK FENCES TO SAFEGUARD PEDESTRIANS Sidewalks and road- ways would be separated by “pedestrian-proof” fences, under a traffic plan offered by an eastern engineer. Walkers could cross only by bridges or tunnels, and provision is made under the project for traffic lanes, permit- Dog Teams Bark Where Engines Puffed; Scenes on Railway near Non Alaska; the Dogs Ride down Grades with Passengers

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ice pe) t = POPULAR MECHANICS 75 [ousekeeping, yea & © .% \ 1 . — . a : J Steward Must Be Able to Tell What Passengers Will Eat Each Meal during Days or Weeks at Sea 1)° you know what John Smith is go- ing to have for breakfast two weeks m day after tomorrow? Would you villing and anxious to hazard a guess to William Brown’s choice of meat for ner a week from Tuesday? Or have uu any idea what you yourself will hoose for next Monday noon’s lunch? ‘hose are only a few of the problems confront the men and women who keep house on the seas—the stewards of he big liners that ply between world ports. \nd not only must they be willing to guess e answer to such problems as this; they ust also back up their decision by actu- ly ordering their supplies accordingly, remembering always that there are no rocery stores at sea; that all passengers ust be kept happy and satisfied; and, last nd perhaps most important of all, that he profits of the voyage depend very ma- rially upon their guesses being accurate, that waste may be reduced to a min- um. Che figures in which those who keep suse at sea deal are stupendous. The chief steward of a big liner orders twenty- four tons of potatoes for the voyage from New York to San Francisco via the Pan- ama canal. with fully as much unconcern as the housewife telephones to the neigh- borhood grocer for a quarter’s worth of the same commodity. And when the ship arrives at its destination, it will be found that twenty-four tons was precisely the right amount. Scores of other com- modities are purchased in the same way, and the ship sails serenely on its journey, not at all worried by the fact that there will be no further possibility of purchas- ing stores until the destination is reached, nearly three weeks hence. How is all this accomplished to the sat- isfaction of all concerned? With a view of finding out the answer to that question, the writer sailed out of New York harbor a few weeks ago aboard the big inter coastal liner “Mongolia,” bound for San Francisco, eighteen days away. Alto gether there were some 300 passengers aboard the ship. In addition, a crew of approximately 200 men manned the ship,

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760 making a total of 500 hungry individuals to be fed, boarded, and otherwise cared for curing a period of nearly three weeks. Yet so unworried by the prospect of this seemingly herculean task was the chief steward, Lewis Daughtrey, that he strolled about the deck at sailing time, greeting passengers, casually chatting with friends, and otherwise enjoying to the utmost the excitement that always attends the depar- ture of a big passenger ship. Out on the Atlantic, a couple of days later, with the routine of sea life settling into quiet channels, Mr. Daughtrey con- ducted a party of curiosity-impelled pas- sengers down into the maze below decks to see just how sea housekeeping is ef- fected. The first stop was made at daily- muster time, to get an idea as to just what POPULAR MECHANICS the steward’s department consists of the way of personnel. One hundred an seventy-two men and women were foun to compose the so-called “victualing de partment.” Here is the way they are di- vided: sixteen bedroom stewards; si bathroom stewards; five stewardesses seventy waiters; three bellboys; on lounge steward; three deck stewards three smoking-room stewards; one che! and twenty cooks; five pantrymen; seven utility men; five plate washers; one chief baker and four assistants; one confec tioner; five butchers; five storekeepers two barbers and nine miscellaneous. Personnel being thus made somewhat clearer, equipment was the next logical in vestigation. Down into an amazing vast ness of spotlessly clean rooms went the party. Huge refrigerated rooms of tem peratures varying from eight degrees above zero to forty-one degrees, big enough to play tennis in, were found at every hand. To the amateur, classifica tion seemed a hopeless task, but with the aid of the chief steward, they were arranged in orderly fashion as fol lows: a vegetable room; a fruit room: a beef room; a fish and ice room; an ice-cream room; a salt-meat room and a butcher shop. Other rooms, not refrigerated, turned out to be a bulk storeroom; a cuddy store (to be explained later); a bake shop; three galleys (a seagoing name for kitchens), and two dining y rooms, or saloons, although it 5 should be explained that o ~*~ . As the Steamer “Mongolia” Glides Out to Sea, Chief Steward Lewis Daughtrey, Head Housekeeper for 500 Persons on the Voyage, Prepares Menus from Cookbooks and Food Statistics

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POPULAR MECHANICS q ae Corner of the Men’s Ward in the Hospital; It Accommodates Fifty Patients, and Is Quite Bas Comfortable Even Better Equipped than Many Such Places on Land, a Modern Liner’s Hospital Is Fitted for Handling Emergency and Other Operations of Wide Variety, and for Treating All Sorts of Diseases; at the Upper Left, Is the Operating Room, Showing a Corner of the Table in the Foreground and Sterilizer at Rear; at Right, the Dispensary Headquarters with Part of Stock of Medicines and the Steamer’s Chief Surgeon; Frequently, Smaller Boats Use the Radio to Ask the Doctors of the Big Ships and Those at Base Hospitals for Medical Advice ba ky v ¢ > 761

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762 the sea name for dining room has by no means the same significance as on land. Now just how does the sea housekeeper go about determining what to purchase for his three weeks’ absence from supply sources? In the first place, he has before him a chart, based on years of experience of seagoing folk, which shows the average ounces of food consumed per person per day under certain conditions. With this, and with knowledge as to the number of passengers who are making the trip, the chief steward works out a table of “meal days”—a single figure which tells him the approximate ounces of food that will be consumed on the trip. On this particular voyage, he figured that he had 24,428 “meal days,’ and by multiplying this figure by the number of ounces of food averaged under the conditions through which the ship was traveling, he knew what would be required in the way of food. With this figure determined, stores are purchased accordingly. Here is where the element of chance would seem to en- ter. How can the chief steward tell that Ebenezer Higgins will choose bacon and not ham with his eggs a week from Saturday? The answer |} Corner of the Butcher Shop, as Important to the Ship Dweller as Is Its Counterpart on | Shore; Below Is the | Steamer’s “Cuddy Store,” Operated like a Grocery on Land; Various Cooks Call on the | Storekeeper to Get | Their Day’s Supply of Groceries | POPULAR MECHANICS is simple; he can’t. But he does kn that, when you combine Ebenezer Hi; gins and 299 others passengers into on lot, a certain percentage will order ha: and a certain percentage will order baco and that’s all he cares. Of course, ther is the possibility that Ebenezer will sud denly stand up in the dining room and de claim “the bacon’s fine this morning,” o: words to that effect, and that every pas senger in the saloon will order bacon. That brings in the next element to be con sidered—‘overscale.” Overscale is what has to be provided to offset unexpected upsets in the law of averages. Upon the careful calculation of overscale rests largely the financial success or ruin of thi steward’s department for the voyage. And so the various commodities re quired for the three weeks’ trip are pu: chased and stored away in the various rooms heretofore enumerated. The next thing to be considered is the daily menu This is much more difficult than on land Ashore, people are busy and engrossed i: many activities. If the meal is, on the average, satisfactory, there is no com plaint. But at sea, especially on a long voyage, the passenger is not as arule bus: He plays his deck game; reads his books and relaxes. He has ample time for con templation of many things, including food He is likely to be in a supercritical mood regarding his meals. Hence every pre- caution must be taken to insure complete variety and to cater carefully, for meals perhaps more than any one other thing

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10 om long us" ioks con ood. iood pre- ylete eals, ing POPULAR ke the success or failure of the trip |, eventually, the success of the amship line. The menus are ide up far in advance—perhaps much as a week. The chief — o steward, upon compiling them, distributes copies to the butcher, the baker and others concerned. Here is where the cuddy store mentioned above comes into the general scheme. This is in reality a complete grocery store, with storekeepers in charge. They issue the various commodities just as does the neighborhood grocer. Each night the storekeeper, the butcher and the others render an account to the chief steward. Not only does this show the quantities issued, but also the quantities left on hand. If there is an unusually heavy drain on one commodity, menus can be arranged accordingly; similarly, an oversupply of an article can be cor- rected. Thus goes the problem of meals—the main consideration of the steward’s de- partment. That by no means ends his vorries, however. Under his supervision come such questions as the scores of bed- rooms, bathrooms and living quarters aboard the ship. Laundry, in terms of thousands of pieces, must be considered. On this particular route, provision has been made to take as many as 100,000 pieces of laundry from the ship at Cris- tobal, the eastern end of the Panama canal, rush them ashore by small boat; launder them; rush them across the isthmus of MECHANICS 763 Panama by train, and deliver them back aboard the ship before it leaves Balboa, the other end of the canal, six hours later. Likewise the supply of linen must be maintained, and other house- keeping problems of this na- ture attended to. Steamer Pastry Chefs Are Adepts at Fancy Creations; Replica of Eiffel Tower in Sugar Housekeeping at sea does not end with the steward’s department, however. The medical end of the ship’s welfare must not be overlooked. So the ship’s doctor ar- ranged a tour in another part of the below- decks maze. Here was found a complete operating room with the most modern surgical equipment; wards for both men and women, each capable of accommodat- ing fifty patients; two dispensaries, fully as complete as any drug store ashore, and an isolation ward for any contagious dis- eases that may develop during a voyage. Nurses are part of the ship’s complement. Many other minor items are involved in successfully keeping house on the ocean. There is the ship’s printer anda his plant, equipped to do elaborate jobs of printing, including the daily table menus, programs for the ship’s masquerade and deck-sports tournaments; passenger lists and count- less scores of other odd bits of printed matter. There is the daily news, broadcast from shore stations each night, received by the radio operator, and posted fre- quently, so that passengers far from land are kept as fully informed as the man in the center of the metropolis with its many newspapers. There are dozens of other details involved in successful housekeep- ing at sea, and the net result is that, when

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764 POPULAR MECHANICS a sleek liner glides gracefully out of a harbor, whether bound for Southampton or Singapore, San Francisco or the Straits Settlements, it is so organized and so equipped, both in facilities and personnel, that housekeeping can be carried on just " » ( Q as successfully and just as efficiently thousand miles at sea as it can in the neighborhood home, next door to the gro cery store, the butcher shop and the fam ily doctor. SILK FROM SHELLS OF INSECTS RESISTS ACTION OF ACIDS German chemists are reported to have prepared a substance from which arti ficial silk can be made out of the shells of crabs and lobsters, and from claws, feel ers, heads and similar hard parts of vari ous insects such as wasps, beetles and grasshoppers. The substance is said to furnish a base that yields fibrous, plastic masses of sufficient strength to obtain a product more nearly resembling silk than that now made from cellulose. One of its qualities is that it shows remark able resistance to chemical action of all kinds. The hairs or filaments can be produced to every degree of fineness, it is said, and the same basic material, when poured upon glass and permitted to evap- orate the ingredients used to dissolve it, produces a film which can be bent and folded. While tests with the product have been largely confined to the labora- tory so far, much wider development is predicted. Upper View Shows Corner of One of the Ship’s ‘‘Galleys’’ or Kitchens; Below, the Captain’s Table in Mair Dining Salon, Decorated with Fresh Flowers, a Luxury of Modern Sea Travel

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POPULAR MECHANICS 765 “a X-RAY OUTFIT CARRIED IN AUTO or fails to burn. Different sizes of lamps ro- ERVES PATIENTS AT HOMES are used according to the kind of test in- volved. The outfit can be used with a - of the X-ray in determining the ex- rectifier in charging wet radio B-batteries of injuries, and in various other diag- by connecting one test point to the lead TS r ive ti- of el- ri- nd to tic la ilk ne -k- all be irtesy London Illustrated News it Portable X-Ray Outfit in Use; Truck Is Driven to Patient’s Door and Apparatus Taken to Bedside for Making en Photograph While Operators Keep in Contact by Phone 4 es, is considerably extended by means electrode of the rectifier and running a all . portable outfit which has appeared in jumper from the aluminum electrode, to = ndon, It permits. taking photographs the positive post of the B-battery. The of patients in their homes, saving costly other test point is connected with the at id sometimes disastrous removal to hos- negative post of the battery. The current tals or laboratories. The entire equip- is then turned on, the size of the lamp ent is carried in an automobile. Parts used as resistor depending upon the num- ‘cessary for use at the bedside are taken ber of cells in the battery. To charge a to the house and connected to the main’ twelve-cell battery, for instance, requires pparatus with a cable. The doctor tele- the use of a forty-watt lamp, while a sixty nes necessary instructions to an oper- to seventy-five-watt bulb is needed for a tor in the automobile while the photo- twenty-four-cell battery. craph is being made. The exposure ts then eveloped in a special darkroom compart- ent in the rear of the automobile. TROUBLE FINDER SERVES ALSO AS CHARGER For locating open or short cir- uits, and other obstacles to the peration of a wide variety of elec- trical equipment and wiring, a test- g set now on the market is easy use and is quickly put into serv- e. It consists of a pair of testing ndles with removable caps so at different sizes and lengths of id wires may be inserted, two ints of a special alloy intended tt to break or corrode, and a pecial socket with separable plug at fits any standard lamp socket sing either alternating or direct urrent. Positive evidence as to 4 Ss he location and nature of the —_———,, trouble is afforded as the light used Electric Testing Outfit in Use and Drawing of Its Parts, the ith the testing set is illuminated Lamp, Cable and Two Points with Insulated Handles

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66 POPULAR Double Camera for Long and Close Shots; Upper Instrument Is Turned by Motor DOUBLE MOVIE CAMERA TAKES LONG AND CLOSE SHOTS Saving the need of two tripods and two photographers, a double motion-picture camera is expected to simplify the making of films, especially in panoramic work. One of the cameras is cranked by hand while the other is turned electrically. Per- fectly matched negatives are thus obtained at the same time, one instrument being set MECHANICS for close-ups and the other for longer shots. This arrangement greatly he when panoramas of more than 180 deg are taken, as two cameras under such « ditions come within photographic ra: of each other, thus spoiling one of negatives. ROOF OVER FOUR BUILDINGS PLANNED FOR AIRPLANES What effect will aviation have on cit architecture? That it gives promise modifying skylines and causing the deve! opment of special types of buildings seen in a series of sketches submitted ip an eastern competition to meet the re quirements of landing fields for airplane in city districts. The plans are based o: the assumption that planes will be abi: to rise and descend vertically, the muc! desired feature now being sought in he copters of various designs. The priz winning sketch involves the use of hig terraced buildings acting as huge support for the landing roof proper. These build ings would stand on a plot about 1,400 feet square and would rise like towers to height of 950 feet. There would be one tower on each side of the plot. All wou be covered by a superstructure, intende to rise 300 feet above the tops of the su ports and provided with a level, thirt ieet below the landing roof proper, for r pair shops, waiting rooms and other commodations for passengers and ma stir. 1. ae — v « Ne } ak. ie ee Prize-Winning Sketch of Landing Fields for Airplanes in City Districts

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POPULAR MECHANICS 767 Granite kota, Peak, near Harney, in the Black Hills of South Da- from Which Gutzon Borglum Plans to Carve a Statue of Washington, Tall as a Twenty-Story Build- ing, and Sketch Show- ing How the Carving Will Be Done ee onal Photos © Publishers’ Photo Service Nation’s Parks Lure Auto Tourists Westward Millions Tour Each Summer Famous Scenic Spots of the Rockies Where Auto Roads Have Succeeded Pack-Train Routes S' JME millions of automobiles between ‘7 the Atlantic and Pacific are being ined up this spring for the annual migra- m to the scenic wonders of the west. here are three or four million cars in California and the western states, a large umber of which are near enough to the itional parks for week-end trips. Added these are several hundred thousand hich make the overland trip cach year trom the east and middle west. The main roads to the Yellowstone, osemite, Glacier and Grand Canyon rks take the bulk of the travel, but con- tantly increasing numbers are turning side to the less widely known, smaller, ut often more beautiful small parks, both itional and state, and to the historical pots throughout the west. The project started by Gutzon Borglum, rst sculptor of the Stone Mountain me- orial near Atlanta, for 200-foot-high stat- es of the builders of the nation—Wash- ngton, Lincoln and Roosevelt—in the lack Hills of South Dakota has awak ‘ned interest in one of the most pictur- esque spots in the west. The Black Hills region is famous for its grotesque buttes, queerly eroded cliffs and nightmarish stone mountains, all on a gigantic scale. Off the usual traveled routes, and forming, as the) do, an orphan range, their nearest moun tain neighbors being the Big Horns of the Rockies, far to the west, they have es caped the worst effects of too much devel- opment and too much tourist traffic. Within the region which is to be made famous by Borglum’s statues lies the little town of Custer, where the noted general made his headquarters just prior to his last fight, and the town of Deadwood, famous as the wildest and woolliest mining camp of its day. Around about them are the Wind cave and Jewel cave parks, Cus- ter state park, many small caves, sylvan lakes, tree-clad mountains, and, dominat- ing all, the vast time-scarred granite buttes, rising in strange peaks and pillars. At Harney peak, near the Needles, where the Borglum statues are to be carved, the fire rangers’ station, on Lookout summit, is 7,340 feet above sea level, the most siz-

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~—> P POPULAR MECHANICS able mountain height east of the Rockies The top of the gigantic Washington stat ue, more that 200 feet high, will be almost as high up as the tallest peak in the Rock ies, while from a level with the eyes of the first president, the visitor, on a clear day, can look out over the three states of South Dakota, Wyoming and Montana for a distance of 200 miles, and even see the famous “Devil’s Fower, over near Sun dance, Wyo., one of the strangest roc] formations outside the Garden of the Gods. Some 600 feet high and nearly a mile around at the base, its eroded sides rise straight up for most of their height flaring in at the top and out at the base Round the sides it is grooved by time and storm in a series of gigantic pillars, five sided, as a rule, and over six feet thick. Like most of the natural wonders oi the region, it is explained by an old Indian legend, which claims that three India: maidens, out picking flowers, were at tacked by a gigantic grizzly. They sought refuge on a low hill and, when the bear pursued them, the gods caused the roc! to grow up out of the ground. The bear climbed and climbed, but the rock kept on growing until finally the exhausted animal slipped back and was dashed to death be low. The Indian maidens then made ropes of their flowers and lowered themselves to the ground. The deeply eroded marks in the sides of the rock were left by the bear’ claws, the legend explains. The Indian still believe that, during storms, the thun der god takes his drum to the top of th peak and beats it. The fastnesses of the Black Hills coun try were the home and hunting ground ot the Sioux tribe long after white men had opened the main traveled trails to Oregon tothe south. West of them, in the Devil's Tower country, were the Crows, and through the hills the two tribes fought their wars. Custer, Sitting Bull, Wild Bill Hickok and Calamity Jane, have left their stamp on the district. At Deadwood, where Wild Biil was killed, he is buried on Boot Hill, and near by is the grave of Calamity Jane. The Custer state park is not so large as some of the national parks to the west, but embraces many of the features ot Yellowstone, both in natural scenery and big game. Herds of buffalo, elk, deer and bands of big-horn sheep roam its mead- ows and peaks. In the region between the Chevenne and Belle Fourche rivers there is as variegated scenery as any place in the country may boast. The caves rival those in other famous cave sections. Wind cave, a national

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in in in ol ad on il’s nd rhit ok mp ild ill, ne. as >st, of nd nd id- the ere in pus nal the Hopi village attracts POPULAR MECHANICS 769 mument, was discovered by a cowboy iming the hills when he was at- icted by the whistling of the nd through the en- nee, which has since , ‘en much enlarged to tford easy ingress to urists. More than a undred miles of its pas- iges, studded with glit- ring crystal formations, ive been explored. ewel cave, not far away. oasts 1,500 chambers of ystic beauty. Minia- ure lakes and weird rystals built up through he centuries give each a listinctive charm. lo the southwest, the ational Old Trails road, ‘mbracing the famous Santa Fe trail, opens up the land of the Hopi In- lians and the cliff dwell- ‘rs to tourists, along vith the Grand Canyon, petrified forest, the art- ists’ colony at Taos, New Mex., and side trips to the parks around Den- er. The snake dance at in increasingly large at- \ ™ tendance each year, de- \ spite the long drive icross the desert on a most primitive road. Motor roads in many if the mountain states are excellent. (hose through the Black Hills have not nly been carefully built, but were designed to give the maximum of scenic enjoyment. HEAD AND REAR LIGHTS IN ONE SAVE EXTRA LAMP With a telescopic tube at the side, a eadlight, for bicycles or for use on auto- nobiles, eliminates Boots and Broad Skis as One Protect the Sportsman’s Legs and Feet and Simplify Mastery of the Healthful Amusement BROAD SKIS FITTED WITH BOOTS KEEP FEET WARM Roomy boots of a leatherlike material are attached to toboggan-shaped skis now on the market to keep the feet warm and to give a more secure footing. They snap and fasten about the legs, to keep snow from sifting in, and there is a foot harness within each boot. Being wider than the ordinary type, the the need of a sepa- rate lamp for the rear. A red lens at the end of the tube ‘lows from the re- ection of the head- ight. The exten- ion may be closed luring the day or hen it is not need- “l. It collapses, fit- skis are said to afford over deep fluffy snow. They are made in varying widths and lengths, the pair shown in the illustration being eight inches wide and four feet long. ing close to the side t the larger lamp. Combination Head and Rear luminated by Reflection from Large Lamp @The name Siberia Light; Extension Is II- Pr .° a oo tae means “thirsty. more riding power, ¥

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770 ATHLETES ROLL INSIDE WHEEL TO EXERCISE MUSCLES Exercises at a physical-training school in Germany include periods with a unique wheel in which the athlete stands and makes complete revolutions by pushing POPULAR MECHANICS candle and the one to be tested. Bot lights are then’ moved backward and for ward. until the greased spot is no longe: visible on either side of the paper. Whe: this occurs, it is known that the lights dif fused on each side of the paper are of equa strength. The standard candle and the on being tested are probab! at different distances fron the paper. The forme may be only a foot awa) while the other may bh: four feet. If it is, it light is four times a strong as that of th standard candle an: since it illuminates side ways as well as lengt! wise, the distance must be squared to give th: full measurement, or six teen candlepower, of the tested light source. How Sport and Beneficial Exercise in Novel Combination, and bracing against the rim. His feet are secured in sandal-like supports and he holds to the opposite side of the wheel with his hands. Grips are so arranged that his fingers will not be scratched or bruised as the wheel turns for they are on the inside of the frame. The task of roll- ing the apparatus in this way, is said to exercise many muscles that do not receive development with other kinds of equip- ment. It may be used indoors or out. GAUGE LIGHT’S CANDLEPOWER WITH GREASED PAPER Rating of candlepower of light is based upon a standard “candle” which is specified by a British law that deals with gas and electric - lighting under- takings. It provides that the candle shall be a uni- form one made from spermaceti or whale oil, weigh six to the pound and burn at the even rate of 120 grains an hour. In measuring with this standard, a thin sheet of special paper in the cen- ter of which is a waxed or greased spot is used. The paper is held upright in a frame and on either side, at the exact level of the greased spot, is placed the standard Rolling inside Hoop Brings Many Muscles into Play and Develops Balance ever, since the standard candle, no matter how carefully made, is not al ways entirely reliable, the measurement now are usually made with a lamp whic! has a light emission equivalent to that oi ten standard candles. AMBULANCE FOR SICKLY DOGS TENDS PETS OF POOR Medical care for the pet dogs of poor persons in London is now given at one of the public dispensaries. The animals are collected in a special ambulance fitted with compartments that hold them se curely without injury and to prevent shock and jars in case they are wounded. Placing a Dog Patient in the Ambulance; the Carrier Has a Special Folding Top to Hold Occupant Securely

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oot one lals ted se ock ding ‘ POPULAR MECHANICS rbhor Pirates ~2 ~ — By FLOYD TAYLOR YIRATES in New York harbor cost the shipping industry $1,000,000 a year. e on the Spanish Main was dull com- red to that of a modern river pirate in ‘ew York, and Captain Kidd was no more reless with other people’s property in those who ‘follow him in 1926. [hese assertions were made at a meet- ¢ in New York of the Maritime Ex- inge committee on marine and water- ront property. At the meeting shipping en, and men representing the city, state d tederal governments, decided on riing a committee to determine means | hghting the pirates. Some skeptical persons were inclined to subt that pirates could operate in the idst of millions of people, in a harbor irefully protected by police boats and the oast guard, but the records show that these thieves are active, ready to use their guns and successful in robbing craft un- ler way and ships and barges tied to ocks. Here is a case of. harbor piracy: lwelve men in a fast motor launch tied up one night to the stern of the steam- hip “Bridgeton,” lying at a Brooklyn pier. They climbed aboard without the nowledge of the crew. At about 11:00 clock, a sailor walked aft and was seized and bound. The pirates, wearing rubber- soled shoes, crept forward. Not a mem ber of the crew knew anything was wrong on board until he was grabbed, had a gag thrust into his mouth and was bound with hard thin ropes cut from the lifeboat davits. The prisoners were locked up in the mate’s cabin. The last man taken by the pirates was the watchman on duty in front of the ship’s strong box. He was manhandled so that he had to spend the next few day in a hospital. The custom officer on duty on the dock was seized as well as the as- sistant engineer, who had been on shore leave and returned to the ship while the pirates were working. The twelve bandits cut through the heavy steel hinges of the ship’s safe with an acetylene torch, which they operated under cover of a tarpaulin. Their loot consisted of precious metals valued at $12,000. There was one box of platinum and two boxes of unrefined gold and sil ver dust, the remnant of a metal cargo valued at $150,000. When the pirates had emptied the strong box, they escaped in the motor launch. Piracy flourished in New York harbor especially during the early part of the

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~2 ~ ~ POPULAR View of East River above Brooklyn Bridge at Right, the Type of Waterfront in Which the Harbor Pirate Works; Piers for Railroad Barges Back of Warship World War, but the police got it under control for a time. Some years ago it flared up again, and now ship owners say it is as flourishing as in the days when pirates strung their victims to the yardarm or bade them walk the plank. The river pirate will steal anything from a piece of rope to ten tons of coal. He usually works from a motorboat of from fifty to a hundred horsepower. A few of the boats are equipped with Liberty en- gines and some of the harbor piratesfalso engage in rum running. Some of them have deserted piracy for rum running or to “high-jack” the rum runners, but their places have been filled by other criminals. A long string of coal barges started at night, in tow of a tug, from a coal pocket on the New Jersey shore of the Hudson, bound for a Manhattan dock. On the tug there was the usual crew of twelve men and on each of the barges a captain to MECHANICS tend to the lines and act as watchman Five river pirates in a dull-gray boat, with racks carrying rifles and revolvers and with bullet-proof glass in its port holes, followed the string of barges as they plowed along at three or fotir miles an hour. In mid-stream, the pirates ran their craft above the last barge, cut out the motor and allowed the boat to drift down onthe barge. A moment later three shadowy figures plunged through the darkness against the barge captain. He was gagged before he could cry:for help While he was stretched hound tm*hi cabin, the pirates shoveled tén tons of coal to the deck of their boat. In the morn ing they sold it to peddlers on New York: east side, or to coal dealers in some smal town on the waterfront near New York. Cargoes are stolen from barges at thei piers. The pirates will take anything that is salable, lumber, wool, hides, coffee, tea

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ee ate nan oat, vers ort they 3; an ran out drift hree the He help hi coal orn ork’: mall rk. their that , tea POPULAR MECHANICS 773 Custom Agents In- specting an Ar- mored Motorboat Shelled by Ma- chine Guns Before Being Captured and Relieved of Its Contraband Car- go; Bullet - Proof Glass Withstood Heavy Fire One of the New Speed Boats for the Dry Fleet, Making Thirty Knots an Hour during a Trial Run

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POPULAR Towing Coal Barges Past the Statue of Liberty; Like Sea Robbers of Olden Times, Harbor Pirates Sometimes Plunder These Craft While in Motion silk, sardines, canned fruit or even the ropes that tie the barges to the docks. Barges have drifted into the harbor to be wrecked by passing ships or go aground as a result of harbor thieves taking their ropes. The rope on one barge is worth several hundred dollars. _The barge companies cannot afford to arm their vessels and employ special po- lice, the shipping rates are too low. The marine division of the New York police department does its best and occasion- ally breaks up bands of the pirates, but its task in guarding more than 500 miles of waterfront is a tremendous one. In addition to the passenger ships and freighters in the harbor, the police have to guard thousands of barges, hundreds of tugboats and an endless list of small craft. One of their jobs is to catch rum runners. The coast-guard force protect- ing the harbor is well equipped with high- speed boats. Its main work is to capture the rum runner, who may be a pirate on the side, but the guard is ready to go into MECHANICS tine “ae action against the pirate who is not a rum runner if necessary. Some time ag a watchman on a Jersey pier saw two me! climbing aboard a railroad barge, weight ed down with cars containing valuab| shipments. He shouted at the men as h« drew his revolver. The reply was a bu! let that passed through his coat. He emp tied his revolver at the pirates as the dropped to the deck of the motor launc! and sped away from the dock. Th: crews of a police boat and a coast-guar vessel heard the shots and gave chase. Th pirates opened up their engine to the limi and roared down the river. The police boat was outdistanced, bu the coast-guard chaser gained gradual! and opened fire with a machine gun. One of the pirates knelt in the stern of his boat and tried to pick off the machine-gu'

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, f ;

POPULAR MECHANICS

crew with a rifle. The pirate craft shot into the Buttermilk channel between the Brooklyn shore and circled Governor's land twice, with the gun battle contin- uing. The chase was ended when the motor of the coast-guard boat suddenly broke down. One of the most highly organized gangs of river pirates that ever fought for loot n the harbor was broken up a few years igo by the police. In the trial of several § the men in the federal court, it was charged that they had stolen goods worth $6,000,000 from ships, barges and railroad cars in riverfront yards, in the years 1919 nd 1920 alone. — Forty-eight men charged with being members of the gang were indicted in June, 1920, and during’ the next year, twelve of them pleaded guilty. Two ring leaders and two minor members of the gang were convicted in 1921, the specific charge being the theft of 375 bolts of worsted from a freight car in May, 1920. (he United States attorney told the jury

~2 ~2 or A Rum-Running Craft Comes to Grief Captured after a Battle at Dawn off South Brooklyn, a Fifty-Foot Cabin Cruiser Being Unloaded of Its 150 Cases of Whisky in the case that the pirates had maintained regularly a fleet of three barges and four launches in the river and had train crews in their employ on every railroad enter- ing the city. On the river, the prosecutor asserted, the members of the gang either bought the collusion of barge captains and watchmen, or forced them by threats to permit thefts. The gang disposed of its stolen merchandise in the south, and the amount was so great it affected the market price in some localities. During the winter of 1921-1922, a fleet of 164 shipping-board steamships, an chored in the Hudson river at Peekskill was looted of furnishings and supplies valued at $400,000. Secret-service men believed that most of the loot was carried from the ships across the ice to shore after the river had frozen. Most of the ship were fully equipped before they were looted and some were almost stripped of furnishings by the pirates. Among the articles taken were brass deck fittings, en gine-room brass and copper, table linen,

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silverware and bed linen. The river pi- rates sometimes work from shore when they believe this method offers them a better chance of escaping, but most of their robberies are from the water. Five watchmen were inadequate to pro- tect $100,000 worth of opium which ar- rived from Turkey in a shipment to a New York druggist. Three of the watchmen were on a pier at which the ship was tied up, at the foot of Congress street, Brook- lyn. The three were captured by eleven young river pirates and bound with wire. The other two watchmen were overpow- ered near the storeroom where the opium was kept. The pirates went directly to the place where the opium had been put, picked up the cases and walked away. They were out of sight before any of the watchmen could wriggle from his bonds. On one side of the pier the steam- ship was moored and on the other side there were two lighters, but neither the members of the steamship crew nor the lighter captains heard the pirates at work. The pirates who are captured usually are tried for robbery or grand larceny, although it is possible that an in- dictment for pi- racy might be obtained. lass. ‘ ». 4 — rae POPULAR MECHANICS There is confusion in the law, and prose- cutors hesitate to attempt to get convic- tions for piracy because the penalty is death and juries in New York are known for hesitancy in bringing verdicts which mean the death penalty. Under the re vised statutes of the United States, it seems harbor pirates might be convicted The most vicious of the criminals in the harbor are the rum runners and high jack- ers who prey on the former. When these engage in piracy, the police-patrol and coast-guard boats must be prepared to fight heavily armed men in launches whose speed equals the best of those of the pro- tectors of the harbor. Some of the rum boats are armored with steel and have portholes of bullet-proof glass. Several of them are converted submarine chasers Take it all in all, the marine police be lieve the saying that “the policeman’s life is not a happy one,” is right. BIG DIRIGIBLE IN THREE UNITS FOR ADDED SAFETY Consisting of three separate units hitched together with steel cables, a diri gible designed by a German builder is in tended to be proof against storms, to have greater lifting capacity without sac rifice of speed, and to be more easily handled than a single ship. In an accident to one or two units, passengers and crew could board the undamaged section and cut the others loose. Police Launches at Their Dock, Ready for Instant Response to Call for Service to Guard Property or Pursue Harbor Pirates; Tripods on Top of the Pilot Houses Are for Machine Guns; the Boats Are Further Identified by Police Flags

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n to ly nt id aw a POPULAR MECHANICS 777 \ zon Borg- with Mod- nd Cast of ysed Cowboy tue for Texas BRONZE MEMORIAL TO COWBOY TO STAND NEAR THE ALAMO Resting On a granite base, twenty feet a bronze memorial to the cowboy of yneer days, designed by Gutzon Borg- will depict a scene from the range, » cattlemen on horseback with part of erd of longhorns at the side and rear. Other views from the days of the cowboy | be represented on panels at the foot the monument. The bronze figures ll be fourteen feet high. The statue, hich will stand near the famous old Ala- ), at San Antonio, Tex.,-is expected to in the neighborhood of $100,000. FIVE HUNDRED KINDS OF WORK OPEN TO AMERICAN WOMEN From a study of the employment con- tions of more than 340,000 women in the st seven years, the women’s bureau of department of labor has found that iale workers are now admitted to 537 flerent occupations in this country, or but thirty-five of the total number list- by the census reports. The survey ws that there has been a steady de- ise in the number of women engaged domestic and personal-service activities, hile the greatest increases have occurred the clerical and professional occupa- ms. It was found that seven out of ery ten single women who live at home e their money to their parents, getting ‘k for themselves only what can be red after the family needs have been met. The reports showed that about tour out of every five women in industry are single. According to Miss Mary Ander son, director of the bureau, industries are being found which offer women not only a living wage and opportunities for ad vancement, but which base the pay on the job itself and not on the worker's sex. BLOWER FOR BURNING GASES REDUCES FUEL BILLS Easily installed in front of the ash-pit door, a blower unit for furnaces that burn small sizes of anthracite coal, is said to in crease greatly the efficiency of the fuel as it ignites gases that ordinarily do not burn but pass up the chimney and are wasted. It is so ar ranged that the extra supply of air it af fords is heated and provides the neces sary oxygen for the combustion of the gases arising from the fuel bed. No cl sary in the grates or dampers of the or dinary furnace for installing the blower, and its use permits burning small sizes of coal that could not be practically consumed without it langes are neces @q Our Bureau of Information will answer all questions regarding articles appearing in this magazine.

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Copyright, Harris & Ewing For Faster Mail Deliveries; Operating Combination Letter and Stamp Canceler in Washington Post Office LETTER STACKER AND CANCELER SPEEDS HANDLING MAIL Letters are stacked, faced and canceled in a continuous operation by an improved device installed in the post office at Wash- ington. It was designed by an expert in the department and is expected to save much time and many dollars annually in handling Uncle Sam’s vast mail. Its chief development over other devices of the kind is the canceling feature. Formerly, after the letters had been faced, that is, ar- ranged uniformly as to back and front, and stacked, the stamps had to be canceled in a separate machine. All three steps are now accomplished in this one unit. Tests have shown that it has a capacity of nearly 130,000 letters a day. It is practically automatic in operation, men being re quired only to feed the letters to the mechanism. GRINDSTONES FORM WALL, CHURCH AND ROADS Hundreds of old grind stones discarded by a large eastern tool works were broken up and used to build a wall around the plant, and more than 2,500 of them were shaped to fit into a church structure. Those that could not be employed in building were used as foundation material for roads within the area oc- cupied by the factory. (78 POPULAR MECHANICS STATIC FORECASTs FOR RADIO FANS NOT POSSIBLE In reply to numerous requests for the service the weather bureau ha announced that predi tions concerning stati: conditions cannot be given to radio fans wit] any degree of certainty According to Prof. C. } Marvin, chief of the bureau, only insufficient studies of static have been made so far, and to go into the subject deep ly enough to justify fore casts, would require ir creased facilities and the expenditure of large sums. If the researc! were undertaken, the scientists would at tempt to establish the relation between thx reception of radio signals and meteorolog ical conditions over a considerable perio of time and, on the basis of data, issu daily radio-forecast bulletins. A ‘ Facer, Stacker ] MODEL OF GIANT MOTORBUS SERVES AS SHOWROOM As a display room during an automobile exhibition, a South American dealer con- structed a huge replica of a motorbus. It was 100 feet long, the wheels were ove: nine feet in diameter and, over all, the bu was thirty-seven feet high. Space wa provided for showing more than 100 tout ing cars. The designer did not reproduce engine and other working parts. OEE IE Huge Model of Motorbus Con structed fe Automobile Showroom; Its Size Is Appar ent from the Men _§ Standing in Front

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iSTS NS E Tous “VviK e. has edic atic t be with inty. bas FF. the cient have id to leep fore 2 in l the large arch d at- 1 the vlog »riod issue JS obile con- It ovet » bus was our- duce POPULAR MECHANICS 779 Psa ME AES z * = 4 For the Seagoing Flyer, the Air Service Provides a Fur-Lined Non-Sinkable Suit Which Affords Both Warmth and Safety in Event of an Accident While Flying over Water By TRUMAN B. MILLS .' ‘CORDING to Chinese tradition dress ‘ was originally for ornament. The otective factor was probably given scant nsideration. Thousands of years of ex- erience in clothing ourselves have estab- hed for us the proper apparel for every- lay use in the different seasons, but no uch experiences can be drawn upon by he flyer in working out clothing for him- elf, since the airplane is less than twenty- e years old. If adornment came first and protection ist in determining the kind of clothing orn by our ancestors, the procedure has een reversed in the development of the lothing for the aviator, for at present omfort is the principal factor. A visit to the equipment section of the Air Service t McCook field, Dayton, Ohio, gives an nsight into the latest developments in lothing for air navigation. R. C. LaVan, ho is in charge of the experimental work n clothing, declares that néw discoveries | value to the flyer are being made con- tantly. For instance, he declares, practically ery kind of hide of domestic and for- gn fur-bearing animals has been experi- ented with in determining the best lin- ng for the winter suit of the aviator. And s a result of these experiments it has een found that the skin of the fawn rein- eer makes the best lining. Mr. LaVan has a large chest in the lab oratory, in which are stored a variety of pelts of beauty and varying degrees of utility from the backs of the Australian and Tasmanian opossum, the gray wolf of the north, the common muskrat, the wolverene of Michigan, the Chinese sheep and goat, the hair seal, and other fur bearers. All have been put through tests to find out their serviceability, and wher- ever they have been found useful, they have been incorporated into some part of the flyer’s attire or equipment. In developing a suit, the engineering division meets the same difficulties as do other branches of the government as re- gards cost. A _ nutria-lined winter suit costs around $250, so efforts are being made to develop a suit without the cus tomary fur lining, in the hope of reducing the cost. Nutria is the skin of a South American animal. One of the new experimental suits has an outer shell of cape leather (domestic sheep), an inner lining of chamots, and a lining next to the body made of single blanketing. This is said to be warm, dur- able, of light weight, and, last but not least, comparatively low in cost. Many of the winter suits have an outer shell of half Bedford cord and half leather. The leather is from the waist up. Bear hide has been used for lining suits, but it is not

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780 satisfactory, because the hairs stand out when the hide gets cold. Wolverene hide is the best for standing the cold. The skin will not freeze and the hair will not be- come frosted from the breath. This fur is used extensively on the sieeves ot parkas, worn in the Northland. Fur-lined gloves, moccasins, helmets and sleeping bags are other items in the cold-weather equipment of the aviator. Gloves lined with northern-wolt iur are standard equipment with the winter cloth- ing. The right-hand glove is often slit across the palm, permitting the aviator to thrust out his hand for writing, without removing the glove. The moccasin worn by the aviator would bring a sigh from the American Indian, who was a great artist at design- ing this form of foot covering. It is sev- enteen inches high and made of moose and elk hide. The lining is of fur. One of the best-looking helmets used is made of coon skin. Another interesting helmet is for the accommodation of radio receivers. Although elaborate clothing must be worn in cold weather, the summer suit is very simple. The best one developed so far is of worsted gabardine. This mate- rial is treated so that it is absolutely water proof. One of these was given-a twelve- hour water test at McCook field, the arms and legs being tied shut and water placed inside of the body of the garment. At the end of the twelve hours, the water was poured out and the suit was found to be perfectly dry. There is still another article of clothing that is proving a boon to all who do any flying over water. POPULAR MECHANICS That is the unsinkable suit. Previous to the designing of this equipment, a fly wore a vest, or vest and coat, lined wit a cottony substance called kapok. These garments proved to be too bulky, soa su stitute was sought. The suits now used are iined with so-called “Chicago foam a spongy rubber, very light and non-a! sorbent. The ordinary sponge rubber ab sorb: water, but the foam may be kept under water for days without taking up anv moisture. A special suit was developed recently for altitude work. It has an outer shell of cape leather, a lining of chamois, another lining of blanketing, and an inner lining of fawn reindeer. This suit weighs six teen pounds. It is made to keep the flyer warm in a temperature of seventy degrees below zero. Electrically heated clothing may be worn by flyers, with electrical pads in the shoes, gloves, over the shoulders, and at various places around the body. It is the tendency, however, to get away from elec trical heating and develop clothing that will keep in the heat of the body and keep out drafts. The two-piece winter suit shown in one of the pictures tells a tale of the clothing designer's effort to get a garment that conforms somewhat to civilian styles in dress. It is made with a heavy nutria lined coat and trousers of goat fur. When the flyer makes a landing near a city and wants to appear dressy and conventional, he just pulls off the goat-skin trousers, and is then attired in the regulation army trousers, making him look less like an eskimo. Fur-Lined Moccasins and Mittens, the Latter with an Ingenious Slit in the Right Palm to Free the Fingers for Writing, and a Fur-Lined Helmet with Built-In Radio Head Receivers

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POPULAR MECHANICS 781 ab kept yup ntl, ll ot ther ling SIX lyer rees

and : - Top, Left, Lieut. John Photos by Courtesy of U. S. Air Service y oo? atl TS

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782 POPULAR MECHANICS Views of the Vacuum Ballast Cleaner Showing Suction Pipes for Both Sides and Middle of Track BALLAST CLEANED BY VACUUM TO SAVE HAND LABOR Operated by steam from a locomotive, a huge vacuum cleaner sucks up ballast, cleans it and returns it to the track at the rate of a thirty-three-foot rail length every three minutes. Dirt and ballast are thrown against a screen within a huge tank in the apparatus by means of a par- tial vacuum created with a steam-driven fan. This screen is set at an angle of about fifty-five degrees, permitting the refuse to fall to the bottom of the tank. The sifted ballast falls to the forward part of the tank where it is caught in small hoppers and finally reaches the track with- in a few feet of the place from which it was taken. The suction pipes, of which there are three, two for the outside of the track and one for the space between the rails, have telescoping joints so that thev can be raised or lowered. Steam for the operation of the equipment is furnished by an ordinary locomotive, which pushes the vacuum cleaner. Steam is also used in a small engine on the front end to operate the valve mechanism through which the ballast is returned to the track after it ha been cleaned EXTRA GAS TANK FOR AUTOS AIDS IN CLIMBING HILLS Motorists are provided with an extra supply of fuel in an emergency tank which may be installed under the hood of the car It is filled automatically when gasoline i put into the main tank and is controlled by a pointer on the dash. It is designe especially for automobiles having the fuel tank under the front seat and i intended to elim inate the necessity) of backin g the car up steep hill when the normal fuel supply runs low. The con- tainer hold enough fuel t: run the auto five to seven miles, ts securely bolted t: the car frame with stout angle iron supports and admits the gasoline directly into the feed line when the pointer control is turned to the proper position. | @ Twenty-six days were required for the trip of the first steamer to cross the At- lantic ocean.

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_ team gine Prate 1 the t ha »S *xtra hich ‘car ne | olled rnecl fuel the id i *lim- ssit\ ’ the hills rmal runs oO n- Ids to five 3. 1S d to Lme igle and feed rned the At- POPULAR MECHANICS 783 EFUGE FOR BIRDS ON MISSISSIPPI For the protection of kinds of wild fowl, ls and animals, a pre- ve is being established both sides of the Mis- sippi river, beginning Rock Island, Ill., and tending north for a tance of approximate- 300 miles. This tract is chosen largely be- use the river valley is e main airway for mi- itory birds. The ref- e will be limited to the ttom land that lies be- een the river and the luffs, which, at places, e to a height of 400 et. Hunting and fish- r will be permitted here nder restrictions. The nd is now being ac- uired from part of an Runner Breaking the Tape at End of Sprint a Few Yards Ahead of Speedy ppropriation of $1,500,- 00) for the project made by congress. he new reservation—when fully devel- ped one of the largest in the world—will e known as the Upper Mississippi River vild life and fish refuge and be under con- rol of the U. S. biological survey. SNOW MELTED BY HOT ROLLER TO SAVE SHOVELING lo reduce the cost of snow removal in arge cities, and to do the work more rap- idly, an eastern inventor has demonstrated his solution of the problem, a huge roller propeiled by a motor truck and which may he heated to 2,000 degrees Fahrenheit if necessary. According to reports of a test of the roller in New York city, iter a heavy storm, the outfit quickly dis- solved the now, Melting Snow with Huge Roller Pushed by Tractor; Drum Can Be Heated to Temperature of 2,000 Degrees Fahrenheit Whippet Which Was Gaining Steadily RUNNER IN RACE WITH WHIPPET WINS BY ELEVEN YARDS In a feature race between a sprinter and a whippet in California, the man won by eleven vards, but he had the advantage of a seventy-five yard handicap and the dog was gaining on him at the finish. The dis- tance run was 200 yards with the lanes marked as in a regular contest. FRESH-WATER SPRING IN OCEAN DISCOVERED OFF FLORIDA Five miles off the east coast of Florida, a fresh-water spring with a flow estimated at several million gallons an hour, has been discovered by officers of the hydro graphic survey. The water was found rising at considerable velocity above the surface of the sea. Small boats were pushed away by the force of the current and when a bucket was lowered, the crew had no difficulty in ob taining a day’s supply of pure, fresh drinking water. The spring issues from layers of rock under the bottom of the ocean and is more than 150 feet deep, by about twelve feet in di ameter, although the floor of the sea at this point is but fifty feet be- low the surtace.

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784 POPULAR TRAFFIC-LIGHT CONTROL BOARD SIGNALS REGULATES ae > ‘& - —;} 42 a> lal ™ f 7 4 ts Tr: ‘¢. ; ait St ! = s cP Zz : . * , oe met Maes Seek gro: hs fe or — 3 «4 ‘ ’ » P aaL ar oS ' 4 : cy -* ; 5 2) ¥ , ‘ > . Se * ; b b) | 4 t f , . ‘ .. e* : ; >) Where Lights Governing Traffic of Chicago’s “Loop” Are Controlled; the Main Switchboard in City Hall One of the features of the newly in- stalled automatic traffic-light svstem in Chicago’s “loop” district is the central control board located in the city hall. From this unit, intervals between the sig- nals may be changed with little difficulty, if circumstances demand the alteration. Forty-nine street intersections are erned by the system, which is not syn- chronized as in most installations of this kind, but so arranged that the length of the “stop” and “go” intervals greater or less at some crossings than at others, depending upon the condition of traffic. gxov- 1s PLATINUM DEPOSITS IN AFRICA START NEW FORTUNE RUSH 1 South Africa has attracted a rush of miners, who like the dauntless adventurers of Klondike days, have penetrated remote parts of an unsettled country, far from railroads and navigable streams, in *h the rich deposits that are believed to be contained in an area of 2,000 square miles in the Transvaal. The hazard of malaria fever adds to the dangers of the rush and ma- chinery must carried through the Discovery of platinum it of searc be MECHANICS jungles by pack. To find the metal, de shafts must be sunk. Platinum was di covered in the district about three ye: ago, and richer deposits unearthed in 192 but the finds were kept secret until tl news finally leaked out. With the met selling for about $125 an ounce, the lur of the new fields is naturally strong ROCKS SEALED WITH CEMENT AID TUNNEL BUILDERS Compressed air drills are thumpi: under the Mersey river in Eng land workmen drive. shaft through the rock to connect Li erpool and Birkenhead by a hicle tunnel which will shorte: the journey between the citie and speed up traffic. Preliminar as Ve small passages are being con structed first, and as the worl proceeds, holes are bored into the rock and these are filled wit! cement to seal the strata so that work on the main tunnel can be done without the hindrance of seep age. The finished tunnel will be a mile and seven-eighths long; the roadway thirty-six feet wide, will accommodate four lines of vehicles, and there will b: three entrances, two in Liverpool and one in Birkenhead. Spiral approache reduce a steep ascent and, like the auto tunnel under the Hudson river in Ne\ York, the Mersey shaft will be thorough] ventilated to carry away exhaust fume from the motors. BOWLS OF RUBBER FOR BULBS CAN’T BREAK OR SCRATCH Pliant in design and vari colors now on the mat ket for growin flowering bulb The advantage of their use that they retai their shape, can not break an will not mar the furniture Furthermore since they at soft rubbe bowls classic ous are are é and un affected by moisture, they are not likely to cause stains on any surface upon which they may be placed.

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POPULAR MECHANICS 785 LIVERPOOL PORT OF LIVER. orricesy EM STING Ra L wer | ’ TUNNEL = rhe Gr section Drawing Above Shows Preliminary Tunnels in Relation to Main Passage; General View of nt Entire Subway in Center, and at Right, Diagrams Illustrating Method of Construction and Plan

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786 FIDDLE WITH BEER-KEG BACK PRODUCES CLEAR TONES Strings stretched over an.old beer keg as a sounding board and carefully tuned, afforded a western musician a novel fiddle for playing old- Beer-Keg Fid- ~~. time dance music. for dle Old- The i i eo ts The instrument is Has Mellow Tones and Is Easily Held said to have pro- duced _ agreeable tones and was made ready for use with a few odd pieces of wood. OIL FROM FOSSIL FISH DEPOSITS FOUND IN TEXAS Near Burnet, Tex., teamsters used to stop their wagons occasionally and grease their axles with an oily substance that seeped from the ground. Recent- ly, it has been discovered that this substance comes from a large deposit of prehistoric fish or marine animals, which produces, upon distillation, an oi] known as ichthyol, valued as a curative agent in the treatment of various skin diseases. The deposit is from two to seven feet deep and extends over nearly 2,000 acres. It ri- vals the natural source dis- covered some years ago in Germany. That country had a monopoly on the oil, POPULAR MECHANICS Expert Cage “‘Toters’’ Employed at German Canary Farm and during the war, prices rose from $5 tp $80 a pound. From the shale in which the substance is found may be dérived , base for paint, shellac and varnish. Sogj. um, zinc, ammonia, silver, gold and plati. num are also found, and fertilizer can be manufactured from the residue, it is said Perfumes and a synthetic gunpowder ca; also be made, according to reports. Ex perts wha have examined the valley esti- mate that there is enough of the deposit to last the United States 600 years. MOVING DUMMIES FOR TAILORS REPLACE LIVE MODELS Automatic models that move their lips, eyes and heads, by means of electric mo- tors hidden in their chests, have appeared in Paris tailors’ windows. They are being used instead of the conventional wax and live figures and in a wide variety of shapes and sizes, corpulent, small, plain-featured and otherwise more closely - resembling some of the actual persons for Whom the costumes are intended. The faces are composed of fiber and plaster. “NURSES” ATTEND CANARIES ON OCEAN VOYAGES Canaries shipped into the United States from Germany and other countries art usually carefully tended by special kee; ers, to feed and water them on the voyag About 2,500 canaries are allotted to man. In one German city, from thousands of canaries are exported annu ally, the workers become proficient carrying large numbers of light woode: cages in which the birds are shipped. } re seer me

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POPULAR MECHANICS ~2? 72) ~ I $5 to hich eda Sodi- plati- can be S Said er car Ex- y esti- leposit LORS ir lips, ic mo- peared » being ax and shapes atured mbling ym the es are spectacular, thrilling and highly fitable profession of whaling, al- lost art during recent vears, has ick into existence and permanency e discovery that the waters of the otf Mexico, Lower California, and e west coast of the United States almost boundless field to whaling tions. thickly inhabited is this region that the season just ended, a Norwe- eet of three vessels, operating off the \lexican coast on an experimental determine the value of these wa- m a whaling viewpoint, obtained iles. When it is considered that average in the neighborhood of tons each, it is easy to realize the ht that can be derived from a pro- ld of this sort. ing, as carried on by the Nor- expedition, is unrivaled for sheer nd excitement. From the time the ive port for the whaling grounds Are Often Towed to Port, Instead of Being Cut Up at Sea, Since the Addition of Air Compressors on the Steamers Enables the Crew to Inflate the Carcass and Prevent Sinking By FRANK B. HOWE until they return, perhaps months later, there is never a dull moment. The rou- tine of sea life as experienced on merchant ships and passenger liners is unknown to the whaler. He never knows at one mo- ment where he will be the next: whether the day will vield fruitless search and end- less cruising, or be a-succession of dashes battles and prizes. In short, if one is looking for all the romantic side of sea life, plus rapid-fire action and excitement, whaling is the ideal profession. It entails tremendous and plenty of hard work, but it offers returns, both physical and financial, in proportion. The whaling fleet consists of three “killer” ships and a mother ship. The mother ship is a lubberly craft that plod along and acts as tender to the small, fast killers. When these have succeeded in capturing a whale, it is towed alongside the mother ship and the latter attends to the routine work of dissecting it, extract ing the oil, and other energy disagreeable but

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nf 788 POPULAR MECHANICS food, fuel and other necessities, and, in general, attends to the work of mothering the smaller ships and thei; crews. All the thrills of whaling come on the kille; ships. They are small, sleek little boats, with an almos: unbelievable supply of power. They are designe; and built for speed and easy maneuvering, and jp case of necessity, in pursuing a whale, they ca: almost literally be stood on end and turned in their own length. The most distinctive feature of these boats is the harpoon gu: in the bow. This resembles, to quite degree, the old-time Civil War cann to be found in every park and pub! square. It is mounted ona revolving and before the killer ship starts out on it errand, it is swung inward and loaded Loading consists in inserting the harpoor in the muzzle of the gun. The harpoo: is about four feet long and the rear end is attached to a long coil of rope. When th: harpoon has been inserted, the explosiv: head is attached. This is a hollow iron de vice with a sharp point. A quantit black powder is tamped into it and head screwed onto the harpoon. The gu: is then swung around again and al ready for the appearance of the pre) compressed-air hose is arranged nea: for reasons which will be apparent late: With the gun thus loaded, the starts out to look for a whale. Hig atop the mast is a barrellike device whi serves as a lookout tower. A sailor is st tioned in this lookout with a poweri glass. To him falls the first duty o trip—locating a whale. As the ship crui around in waters where the whale necessary work while the killer goes back likely to be found, the lookout ceasel: to prowl over the seas in search for more sweeps the horizon with his glasses. Sud whales. Likewise the mother ship acts as denly the historic call “there she b! supply ship to the smaller boats; furnishes comes from his station and instantly t! From His Barrellike Lookout Station, Known as the Crow's Nest, the Whaler Keeps Watch over the Sea for Tell- 7 tale Waterspouts Taking in the Slack after Harpooning a Whale; the Photograph Shows a Thirty-Knot Speed Boat Us« New Zealand Whalers to Run Down the Fast-Swimming Prey at Sea

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irpoo! end is en the VIOSIVE ew and the Old, a Whaling Speed Boat in the South Atlantic, and Ancient American Whaling Bark, Now a Museum POPULAR MECHANICS 789 yet ship becomes a beehive of activity. Che course of the ship is directed toward the spot where the whale has been sighted. The captain or the first mate mans the gun, ready to fire when the quarry is close enough. Perhaps the chase goes on for miles, the killer maneuvering for an ad vantageous position as the whale dodges about. Finally, if all has gone well, the whale suddenly appears to blow di rectly ahead of the craft \s it rises to the surface the hat poon gun is discharged and the weapon is hurled into the gigantic animal, dragging the rope with it. There is a de lay of a few moments while the whale dashes about in frenzy and suddenly tl plosive head of the harpoon foes off. Inevitably this ends

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790 the battle. By no means is the fight to capture the prey over, however, even though the quarry has been killed. Here is where the compressed-air hose comes into play. A hole is quickly made in the body of the whale and the hose inserted. Air is pumped into the leathery hide un- til the whale resembles a small balloon. When sufficient air has been pumped in, the whale floats on the surface and can be handled. Otherwise it would sink and all the work be in vain. Incidentally, this procedure of pumping up the whale has been the subject of much amusement to those who have seen it done. One imaginative newspaper car- toonist pictured hydrogen gas _ being pumped into the mammal instead of air and had the whale floating about in the sky, much to the amazement of passing dirigibles. With the whale captured and made buoyant, it is taken in tow and brought alongside the mother ship, where the work of extracting the hundreds of gallons of oil and the valuable whalebone is carried on. The killer ship then returns to sea in search for another whale. There is ample excitement to satisfy any- one in hunting and capturing the whale in this manner. But when all does not go smoothly, there is much more of it. For example, a miscalculation may be made and the harpoon glance off the tough hide instead of penetrating it. Then there is an angry whale to be reckoned with. Or, perhaps, the ship may be maneuvered a little too close and the whale rises below. it instead of to the side. Or the explosive head may not function and the whale start for Japan or Alaska with the ship in tow. Or any one of a score of other mishaps may oc- cur to enliven POPULAR MECHANICS the chase. When it is realized th Norwegian expedition captured pra: ly 300 whales in a period of three m: an average of more than one a day { each killer, it can readily be seen that Pacific waters off the Mexican and fornia coasts offer a splendid base erations for the whalers. WASHINGTON’S ENGLISH HOME RECONSTRUCTED HERE Some of the stones and oak bear Warwick priory, an old English count: house, have been shipped to Rich: Va., where it is planned to use them in re constructing Sulgrave manor, the ance tral home of George Washington. kk sides the beams and other parts, c: of leaded glass windows and as muc! the carved interior of the old prior could be removed, have also been import ed. The builder plans to use the re structed manor as a residence, and the: place it in the hands of the Virginia | torical society as a museum. The Latest Thing i: Steam Whaling Ships with Poweriul Gun the Bow and Lookout Station High on the Mast; This Speedy Shi Pursues and Kills the Whales, But Does Not Do the Cutting; Above Is the Gunner Waiting for the Whale to Appea

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7)’ 3 oe Being Thrown by Hand POPULAR MECHANICS 791 4 Modern Whaling Harpoon Is Shot from Gun Mounted on a g¢ Boat, Instead of rom a Small Rowboat; Above, the Harpoon Is Be- ng Loaded in the Gun, and t the Right, the Explosive Head, Which Kills Quickly, Is Being Screwed in Place by the Gunner With Rope Attached and Coiled Down, and Harpoon Capped with Explosives, the Gun Is Now Ready to Be Fired

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792 POPULAR MECHANICS GAS TO REPLACE SAILS FOR LIFEBOATS ON LINERS Where Wind Is Making Its Last Stand as an Ally to Navigation; Pacific Liner “Harvard” and Its Fleet of Sailing Lifeboats; Rigging Is Simple to Facilitate Handling in Emergencies Sailing lifeboats on seagoing liners, the last bulwark of wind power in the pas- senger-carrying trade, is now being threat- ened by the gasoline motorboat. The Brit- ish government requires all big English liners to carry a certain number of power: boats, equipped with wireless, to tow thie other lifeboats in case of shipwreck, so 1t may not be long before sails disappear forever from passenger ships. VACUUM CLEANER FOR FURNACE SAVES TIME AND WORK Operated on the same principle as the apparatus for cleaning rugs and floors, a vacuum outfit to rid the furnace of soot is carried from house to house on a small automobile truck and has extension suc- tion pipes to make connections from the street. A huge bag collects the dirt. Vacuum Furnace-Cleaner Outfit; Big Dust Bag at Rear with Section of Pipe Counecuon to House in Center LENGTH OF NATIONAL AIR HELD TO SHOW SIZE OF COUNTRY That there is a curious relation betwee: the length of the national tunes and the size of the countries they honor, is the ob- servation of an English musical expert Only fourteen bars of music make up “God Save the King,” yet the British e: pire is enormously vast. The old Russian national hymn containe‘! but sixteen bars, where the national anthems smaller countries are much longer, the 5S: mese song, for insian having sixty-six bars ar that of Uruguay, sevent bars. “Hail Columbi« contains twenty-eig! bars and one of the lon est hymns in the world that of the tiny repul! of San Marino. Chi apparently is an exce tion, as no less than h a day is required to si! its national anthem.

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ELD wee! POPULAR MECHANICS 793 FRESH TIMBER CURED IN DAY BY VACUUM PROCESS Fresh-cut lumber can be seasoned suf- iciently for the carpenter’s bench within day or less by a high-vacuum process a Swedish engineer has discovered, accord- ng to reports from Stockholm. Green birch boards are made ready for construct- ng furniture in twenty hours, spruce and sine in thirty and oak in forty. The lum- rer thus cured is said to be free from ‘racks, warps and “blue” spots. Planks ire placed on rollers and slid into air-tight chambers where they are first heated by steam from coils and then pumped dry by acuum. The procedure is repeated ac- cording to the nature of the wood. CAN OPENER WITH TURNING KEY CUTS TOPS OF ANY SHAPE Adapted to angular as well as round tops, a can opener now on the market is intended to reduce the work and danger of cutting the tins. It has a sharp-edged and a ratchet wheel between which the rim of the can is clamped by means of a lever. By turning a broad key at the top, the ratchet easily turns the can while the opener is held stationary. This simplifies turning the corners on rectangular or square containers and makes it practically impossible for the hands to slip off. Safe- Adjusting Opener to Can, and Lid Removed; Container Is Turned against Cutter with Key ty is further assured by the smooth, flat edge left by the cutter. Replica of Washington Monument in White-Silk Roses MODEL OF MONUMENT IN ROSES AS HONOR «O WASHINGTON Containing 25,000 white-silk roses, a model of the Washington monument has been constructed by a New York man who proposes to have it autographed by persons attending patriotic gatherings and then presenting it to Mrs. Coolidge. On the inside and base of the model are seven large electric lights to illuminate the fig- ure. Nearly three weeks were required to complete the work. OPALS HARDENED BY FANNING TO SIMPLIFY CUTTING Using an ordinary electric fan, an Eng lish gem expert has found a way to harden opals in a current of air so that they can be cut more easily,-it is reported. The hardening is said to so toughen the stones that damage is less likely to occur when cutting and shaping them, and they retain their polish longer. This process also shortens the seasoning period that for- merly was necessary to allow the stones to harden naturally.

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neath oe ee "1 ’ | Views of the Tower Erected at Potsdam for Photographing Light irom the Stars Espe- cially for the Purpose of Further Investigating Einstein’s Theory of Relativity; the Tower tself, with Curious Porches and Windows, Is Like a Huge Tele- scope, But Only the Cupola Part and the Huge Mirrors Move; the Dome Opens and Turns as Usual POPULAR MECHANICS Above Are the Mirrors upon Which the Licht from the Stars Falls; They Are So Adjusted That They Reflect the Beams Down to the Basement of the Tower through the Vertical Light Shaft up Which You Are Looking in the View Below; the Framework Is of Steel, the White Square Is a Reflector, and the Dark Area Part of the Inside of the Dome Courtesy The Spher At Left Is the Tunnel Where Light, Re- flected from Stars down the Vertical Shaft, Is Finally Photographed for Anal- ysis; the Passage Is Fifty Feet Long and Is Insulated, to Prevent Tempera- ture Variations, with Double Walls be- tween Which a Man Can Walk

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POPULAR MECHANICS GOLD MINE OVER MILE DEEP COOLED BY ICE WATER When workers in a gold mine 7,200 feet below the surface in South Africa became seriously affected by the high temperatures, efforts were made to cool the air by placing blocks of ice at various parts of the workings. It was found that this expedient lowered the temperature only one degree. The ice was then melted, the cold water being sprayed into the mine through the ventilating system. This met with far better results and an appreci- able lowering of the tem- perature, which had va- ried from eighty-four to ninety degrees, followed. The problem was not wholly solved by this plan, however, as the moist air with the heat, was more likely to cause apoplexy, while the dry heat alone was produc- tive of other diseases. [he experiments therefore are being con- tinued in order to correct these drawbacks. OLD RAILS AS CROSSING PLANKS REDUCE REPAIRS AND BUMPS Instead of discarding its steel rails after they have served their time on the road- beds, a middle western railroad is utilizing Recalling Past Glories of the Seas; Model of Five-Masted Full-Rigged Ship Exhibited at Motorboat Show in New York some of them for road crossings. They are cut to appropriate lengths and the ends bent down to an angle of about forty-five degrees. They are then placed on the crossing with the curved ends to the ground and are spiked to timbers. Spaces between the rails are filled with a mixture of tar and finely crushed rock. A smooth surface is the result, loose boards that may fly up and damage autos and cause accidents are avoided and re- pairs reduced. Old Rails Installed at Crossing MODEL OF FIVE-MASTED SHIP TOOK THREE YEARS TO BUILD Visitors at a motorboat show in New York city caught a glimpse of the days of spars and canvas in a ten-foot model of a five-masted full-rigged ship. feet high, had a beam of thirteen inches and was ten inches deep in the hold. The It was seven hull was not fash- ioned from a solid block, but was planked and _ ribbed like a real boat. Sails were formed from vertical strips of tape sewed in the same way that actu- al sails are made. Sheaves of the blocks turned when the vards were braced and nearly every other detail was true to life and carefully constructed to scale. The amateur who built the model spent about three years in making it.

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796 POPULAR MECHANICS Railroading Wilds " a: vammbake Thrills and Adventures with Big Game on the Night Mail Trains in the Tropics By HAROLD T. WILKINS | l is a cold night in the wild bush coun trv of India where the great transcon tinental railroad runs through heavy jungle. In the cab of the locomotive, the engineer is trving to make up time to catch the mail boat due to leave for Europe on the following day from a port 800 miles down the line. 1 The I lative fireman reaches for a shovel, when he sees, on the roof of the car coupled to the engine tender, two eves and the form of a Bengal tiger. The fire man 1 ralvzed with fear, but the engi neer senses the danger and looks around. Quick action is imperative, and as he slows the train down to a stop, he jerks open the firebox door. and a sudden blaze of light illuminates the dim interior of the cab. The whistle screams. and the astonished tiger leaps from the car and } the black Probablv, as the track into jungle. icross the night of the night mail stopped to take in water at a wavside tank near the bush countrv, the inimal had bounded on the car in search Tigers, 1 though formidable opponents to encounter at night on the footplate of a racing express, are not the most dreaded enemy of the engineer on a tropical road. On some lines wood fuel IS us¢ One night, the fireman of a mail iowever, _ Pt - i train, running from Bombay to Madras was heaving logs into the furnace, when a cobra uncoiled itself from a billet of wood and reared up into a hooded crest. The reptile had been aroused from its tor- por, due to the cold night air of the trop- ics, by the warmth of the fire radiated from the open door of the firebox. High up on the “roof of the world’- the Himalayas—a picturesque railroad, often doubling back on itself, climbs to the cool hill stations from the burning plains of northern India. As soon as his engine is in the dense jungle, the enginee! stops and lights a flare on the his cab. He does this to scare away bi game from the railroad track. One [Indian train was wrecked by a col lision with insects. It ran into a crowd of millions of locusts. The engineer ap plied his brakes, but the insects had so greased the rails that the train crashed into a dead end. On the French military railroads in Algeria and Morocco, these locusts, at certain times of the vear, darken the sky and cover the ground to a depth of three inches. Only very slowl\ can the locomotive grind its way through the mass. On a railroad in Rajputana, northern India, the train to Delhi was crossing a sandy desert, when the brakes ground the root ot

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The oil-stained, turbaned Hindu engineer bent down and gently pulled the cow’s horns and tail to persuade her to rise. Not for untold wealth will the Hindu en- gineer run down a holy cow. Near where the Victoria falls— a wall of waters 400 feet high— foam over the mile-wide gorge of the Zambesi river, in South \frica, is a splendid big-game reservation. Along this section of the Rhodesian railway gi- raffes are frequently seen from the trains, and elephants and zebras are not uncommon. The line runs through a wild country of jungle and bush, in which the wild pig, the eland, the wildebeest, the dangerous sable an- telope, deer, and, last but not least, man- eating lions abound. One day, not long ago, a passenger train, at a turn of the track, ran into and was derailed by a herd of thirty-six wild elephants. Lions swarm in Rhodesia. On dark wheels. Everybody got out and went up the line to the head of the train, where a sacred cow or white zebu, lost in the desert, had strayed onto the line. POPULAR MECHANICS 797 7 Bridge Building in India, Where a Derrick Flat Car Handles Com- plete Girders; Center, Building a Temporary I Wooden Pile Bridge, and, Bottom, Unloading a Lo- comotive from a Railway Car in India moonless nights they swoop down on some native cattle stockade. All of them stand out- side the six - foot palings and roar in unison. The wom- en shriek in fear, the men blow trum pets and yell, and the cattle stam- pede. This ex- plains the alarm ofa South African station- master who recently sent two frantic telegrams down the line in quick succession from an upcountry depot on the lonely veldt. “Please send further police protection. Men very brave, but less so when lions begin roaring.” Then, “Please let 10:00 a.m. run up the plat- form, disregarding signals. Signalman up post. Lion at bottom.” A loud whistle announced the arrival of the passenger train from Bulawayo. Looking cautiously out of an aperture on the side of the cab, the engineer saw a full-grown lion stalking an unfortunate man, clinging to the top of a signal post. The terrified station officials had barri- caded themselves in the railroad buildings. The engineer gave a little turn to a switch in the cab, and sucha roaring, hissing cloud of steam burst from the engine’s valves and cylinders, accompanied by a series of blasts on the whistle, that the lion fled. A much worse fate met an ostrich which

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(Rite POPULAR one day charged an express train in South \frica Che kick of this big bird is worse than that of a mule, and it can even fatally injure a man. The ostrich got on the track and ran down the line between the rails, head on toward a South African mail train making up for lost time on the wav to Cape Town. It disregarded the warning whistle, charged the locomotive, hit the cowcatcher and was killed. The Field museum of Chicago retently obtained from Lieut. Col. J. H. Patter- son, an English civil engineer, the skins of two of the most famous lions in the world, who, between them, tied up con- struction on the Uganda railroad for three weeks and interfered with it seriously for before both were finally several months, killed by Patterson. During that time the two lions killed twenty-eight Indian la- borers on the road, in addition to several score African natives in villages of the neighborhood. The depredations of this pair are with- out a parallel in the stories of railroad building in the wilds. Appearing at Tsavo, 132 miles from the coast, the pair for nine months spread terror among the railroad builders, most of them coolies imported [ They invaded the tents at pite strong fences of almost im- passable thorn bushes, and seized and car- ried off the sleeping men almost at will. Two or three times a week, for months, ttered camps were visited, first here from I[ndia. night, de 1 the sca Big Bul MECHANICS 1 Elephant, Leader of a Herd of Thirty-Five, Which Tried to Cross an African Railway Just as the Train Arrived; the Locomotive Was Derailed and Badly Wrecked, Too and then there, until finally the entire working force was driven to sleeping in trees, on platforms atop water tanks, or on special scaffolding erected for the pur- pose. The reign of terror got so bad in December, 1898, that practically all the workmen seized a train and left for the coast, not returning until both lions had been stalked and killed. Starting with two Hindus, seized in their tent one night, the pair began a reg- ular round of the camps. Armed Euro pean officials camped in trees and on spe- cially built platforms night after night, but with uncanny precision the lions for months picked out one of the few un guarded spots and made their raids. In the early days of the raids, the work- men were scattered in tent camps along eight miles of the right of way, some grad- ing the roadbed, others laying ties, and the rear guard placing the rails, so the lion pair had an extended field in which to work. They were not always successful in their raids. On one occasion, a lion broke into a tent occupied by a Greek contractor and by mistake seized and car- ried off the mattress on which the man was lying, but left the occupant of the tent quite unharmed. At another time, one of the animals jumped on top of a big tent in which fourteen coolies were sleep ing, broke through the canvas, and landed on one of the sleepers, clawing his shoul- der badly, but instead of seizing one of the

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POPULAR MECHANICS 799 € att Construction Work on a New Tunnel of the Southern Pacific in the Sierra Nevada Mountains, Where Snow and Intense Cold Furnished Natural Obstacles to the Work fourteen humans, grabbed a bag of rice in its mouth and trotted off with it. As the attacks continued, the lions grew bolder and bolder, until finally nothing flurried or excited them and they took time to pick their victims with care. Shouts, shots and waving firebrands failed to stop them then. During the early months of the reign of terror, while the railhead camp-with more than 3,000 men remained at Tsavo, the workmen accepted the attacks two or three times a night philosophically, apparently feeling that with so many victims to choose from, they had a sporting chance of being overlooked. When the railhead finally moved on, leav- ing only a few hundred men to build a bridge over the Tsavo river and do the final ballasting of the road, the situation became more serious, eventually resulting in the stampede of the workers on a con- fiscated train and total cessation of road building. The men were concentrated in a few small camps strongly guarded by thick and high thorn fences, with bright fires and armed guards on watch. inside the inclo- sures, but despite all these precautions the pair of man-eaters succeeded two or three times a week in breaking through or jump- ing over the obstructions, selecting a vic- tim and making off with him under the eves of the frightened natives. As the lions grew bolder they took to stalking men along the right of way in broad daylight. One coolie trackwalker saw one of the beasts coming, and suc- ceeded in climbing a tree, where he re- mained under guard of the beast until an official caught sight of him from a pass- ing train and stopped to effect a rescue The same afternoon one or the other of the lions was seen in three different places, one, just at dusk, stalking the doctor of the camp hospital. Col. Patterson and the doctor decided to try stalking the lion by spending the night in a freight car parked near a recently de- serted camp. The car had a door built in two parts, and they closed the lower half, leaving the top section open so they could watch and shoot if the lion appeared. The plan was nearly fatal, for instead of their stalking the lion, it stalked them and was in midspring for the open door when both saw it and fired, failing to wound, but causing it to swerve and make off. A trap built in two parts was tried, the inner cage, separated from the outer by railroad rails, being baited with a number of workmen who slept there nightly. One of the lions actually invaded the trap and was caught, but the terrified workmen, fir ing through the bars, only succeeded in shooting off part of the door, allowing the animal to escape. Col. Patterson finally succeeded in shooting one, from a perch in a tree, and

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POPULAR ig after bag other in t! ame way { Oo! sid erable damage is caused to rail roads near the equator in central Africa and South America, when troops of mon- kevs swoop down from trees over trains passing through forests to the coast and under cars loaded with fruit and nuts. In another out-of-the-way part of the world, the vast forests of the Malay penin- sula shelter roaming herds of wild ele- and other fierce and powerful animals, providing plenty of excitement and thrills in the life of the railroad men. \ passenger train collided with a wild ele- phant in the Malay jungle and the loco- motive was thrown from the rails. A few months ago, a herd of rogue elephants at- tacked a lonely railroad depot in the Fed- erated Malay states, tearing up the rails with their tusks. A month later, at night, the wild elephants broke into a passenger depot, smashed the walls and damaged office fittings and furniture. Then a big tiger, bound for Singapore and the New York zoo, escaped from its cage on the railroad, and calmly walked into the com- pound of a hotel. People who were play- ing billiards made a quick exit, and the tiger sought refuge under a table where it was killed by a sportsman. The volcanic island of Java holds some thrills and shocks for railroadmen work- ing its 600 miles of lines. Here no trains run at night, because the Dutch, who con- phants MECHANICS trol the island, cannot or will not trust the native engineers and operators. One re cent summer morning, a train, in crossing a high bridge, crashed into a herd of wild water buffaloes—fierce and powerful beasts. The locomotive toppled over into the river, carrying away portions of the steel girders in its fall, and killing twenty five people. An epidemic of accidents at this place followed. Three weeks later, near the same bridge, a wild buffalo charged into a passenger train, derailed the locomotive killed the engineer and injured the fire- man. Another passenger train, a few days later, was pulled up only just in time to avoid smashing into four of the animals. Monkeys, which have often figured in incidents on tropical railroads, are trapped and caught in the Philippines in a curious way. The animal will swing down by its tail from a tree onto a moving freight car loaded with coconuts. The brakeman takes advantage of its greed and indolence by cutting a small opening in the shell of a coconut just large enough to admit the monkey’s long, thin hand. He puts thi shell in the car, and when the plundering monkey comes on the scene, in goes it paw to clutch the delicate meat. But it hand is now wider than when it entered the nut, and finding it will not come out, the animal chatters and scolds, but never thinks of loosening its clutch on the coco- nut meat, and so is easily captured. British New Guinea; the First Railroad in the South Pacific, a Mine Line Running to Laloki Copper Mines, Papua Owing to the Climate, Native Labor Had to Be Trained

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POPULAR MECHANICS 801 NEW PARACHUTE WITH VALVES OPENS IN SHORT FALLS Vith a series of valves placed along its tire wall to facilitate opening, an im- ved type of parachute tested by the promises to decrease the peril of ents, as it is said to permit successful in falls of 100 feet and less. No skill needed in folding and packing it, re- ts state, and no danger to the airman ults if the cords:should become twisted t the time of the drop. TEA “TICKLED” IN CHINA TO IMPROVE ITS FLAVOR ‘Tickling’ tea as icticed b y % he inese, not only ngs out the fla- but prevents ting the leaf, ac- rding to an Eng- expert. It ap- rs that tea con- ns an active poi- in the form of esséntial oil, and the Chinese do use the tea un- they are sure it it least a vear Inspecting New Parachute at Naval Station; Although Cords Are Twisted, It Opens Readily and Little Skill Is Required in Folding It; at Right, Demonstration Descent from Low Altitude quantity of the leaves is spread upon paper and run through the hands for ten min utes, or so; then put aside in the sun. This treatment causes the leaves to uncurl and admit air and thus create an outlet for the poisonous gases, while later the heat of the sun recurls them in fifteen minutes. LOUD SPEAKER FOR TELEPHONE ADDS TO INSTRUMENT’S USE By attaching a special loud speaker to the telephone receiver, conversations can be heard across a fair-sized room, it is said, and the person listening has both hands free for writing or other work. No altera- tions in the telephone are necessary. The speaker is fixed to the phone with a setscrew and the re- ceiver hook is con trolled by a lever which can be locked so as to hold it raised while the conversation is go ing on. Should the conversation be ot a confidential na ture, the receiver can be used in the regular way after When ready consumption, a Using Loud Speaker Attached to Telephone Receiver Leaves Both Hands Free for Work the speaker has been removed.

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802 POPULAR Upper Picture Shows Plugs in Place and Cress Section ; Below, Driving and Tops Sawed Off EXPANSION PLUG FOR BUILDING AIDS IN FASTENING TRIM Wooden plugs that expand and hold fast when they are driven into tile, brick, concrete, metal lath and similar materials, have been devised by a western inventor, to afford a suitable base for fastening chair rails, molding and other trimmings to walls. It is only necessary to bore holes where the plugs are wanted and drive them in, saving the labor of remov- ing plaster or other surfacing and attach- ing wooden strips. The fasteners are of poplar, bind firmly to the sides of the hole and when the end is sawed off, a conven- ient space for nailing is left. PLAN AUTO-AND-TRAIN TUNNEL THIRTY-TWO MILES LONG Preliminary surveys for the construc- tion of a tunnel thirty-two miles long un- der the Cascade mountains have been un- dertaken by the state of Washington. The bore is to be built for both trains and automobiles and will carry water from the western to the eastern slope of MECHANICS the Rocky mountains for the purposes irrigation. The project was conceived the late H. M. Chittenden, who was a the originator of the idea of linking La Union and Lake Washington with Pu; sound by canals. When completed, t tunnel will be more than twice as long the Simplon tunnel through the Alps TAILLESS SPECIES OF SHEEP SOUGHT BY BREEDER By crossing domestic with a variety Siberian sheep, Prof. J. W. Wilson, « rector of the South Dakota agricultur experiment station, hopes to produce tailless species. After several years careful selection and breeding, a ram w born without a tail, and of twenty-one its offspring, eighteen are practically t less. Prof. Wilson says that the tails n come back in the next generation and unwilling to call his experiment complet but believes that the production of a per manent tailless species is possible. RADIO SET ON BICYCLE PERMITS RIDING TO MUSIC While riding his bicycle, an eastern « thusiast enjoys musical programs from radio set which he has attached to t handlebars and front part of the fran The loop, batteries and other parts are curely connected, to prevent damage fro vibration, and do not interfere with t! rider who can tune the set while in motio Bicycle Rax Can Be Tune While Ridin;

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POPULAR MECHANICS 803 3 mmManitior By CAPT. EDWARD C. CROSSMAN If t P ay " W . fa n d et ve ITS THE flintlock with which two of our irs were fought was as likely to miss » hit a man at a hundred yards. Since ‘ n the improvement in arms and ammu- m tion has been so great that in the last t ernment test at the Aberdeen proving n round, ten consecutive shots were put se to a space hardly larger than a tea cup rol t a range of 328 yards. Taper-tail bul- thi ets, which add practically a mile to the i0 treme range of the missile, were used. ‘y proved not only to add enormously ” he efficiency of the small arms, but to vee e higher accuracy as well. lir No rifleman, even if equipped with the est of rifles and a telescope sight, could and fire the rifle with so little error as for hundreds of shots. Machinery to be called in, and it must be appa- tus accurate to one-thousandth of an h or less to afford such results. he old method of testing ammunition to clamp the rifle in what is known a “machine rest,” which was a heavy teel bed resting on a concrete base, with ps to hold the rifle at the butt, the ie and the muzzle to the heavy slid- base. It was not a satisfactory meth- because clamping down the service rifle rdinary weight would sometimes dis- the barrel, and many a test was lost me company because the rifle used improperly clamped in the rest. n these days a special, heavy barrel is |, twenty-four inches long and one one-quarter inches in diameter. Two " heavy steel rings are placed on the barrel so that, regardless of how it is revolved, it will not change the line of the bore. A V-shaped groove is milled in a heavy block of steel, its sides cut accurately and parallel, and permitting the two rings around the heavy barrel to fit down into this cut. Fine screws move the heavy V- block up and down or sideways. The importance of absolute uniformity is shown by the fact that an error of one- thousandth inch at the muzzle would move the next shot two inches at 1,000 yards, and the comparatively small error of one-hundredth inch would move the bullet twenty inches. Until improvements were made this year, the barrel with a short bit of stock attached, was merely laid in this V-cut in the steel block, a cartridge loaded into the breech and then the trigger was care- fully squeezed to avoid moving the barrel. It slid back under the recoil, and the firer caught it with the palm of his left hand to prevent its sliding clear out of the V- cut. Now a clamp holds the barrel in the V-cut. The heavy barrel, with its freedom from “whip.” or bending in firing, and the accu rate V-cut in the steel base make possible the delivery of 100 shots with no inaceu racy that can be measured. If the ammu nition could be made accurately enough, and the wind would refrain from blowing, this improved Mann rest could almost put one buliet on top of another at a

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804 POPULAR MECHANICS Testing Small-Arms Amm: tion at Government Stati near Daytona, Fla.; Bulk Are Shot at Screen Tar; Placed Fixed Distance fr half mile. by an instrument called the chronograph, The speed of the bullet is tested which merely balances the distance a weight falls against the time taken by the bullet to travel about 150 feet. The bullet cuts a wire as it leaves the muzzle, break- ing an electric circuit passing through an electromagnet and permitting a heavy weight to fall. When the bullet reaches the other end of the testing distance, it strikes and drives back a loose steel plate, breaking another electric circuit passing through a second magnet. This second magnet controls a spring-actuated trig- ger and knife. The knife blade, thus re- leased, flies out and makes a mark in the weight released by the first electric cir- cuit. This nick or mark, cut into the lampblacked weight of soft lead or brass, shows how far the weight fell before the knife struck it, and thus how far it fell while the bullet was passing over the measured distance. The rate of fall of a heavy object is easily ascertained from tables on hand, and it is thus converted into fractions of a second. The internal pressure developed by the cartridge in the barrel of the gun is meas- ured by drilling a hole in the barrel at a point about opposite the “neck,” or mouth, of the cartridge. A little shallow copper cup is pressed down into this hole until it reaches the cartridge, then a steel piston just fitting the hole is pushed down until it reaches the copper cup or gas check. Above this is placed a short piece of cop- per rod, measured exactly as to its length. An “anvil” or block to hold the copper is screwed down against the copper rod, while a housing attached to the barrel holds the steel anvil. When the gun is fired, the gas cuts a little round section out Gun for Measuring Angles Departure of the cartridge case and then drives t! steel piston violently outward. This, turn, compresses the section of copper rod against the steel block above it, shorter ing the copper perceptibly. As the amount of force to shorten the copper rod known by test of the lot in a static ma chine, a simple measurement of the short ening produced by the shot, gives the in ternal or chamber pressure. With very low-pressure arms, such shotguns and .22 rifles, the compress¢ material is lead instead of copper. Recoil is measured by firing the car tridge in a heavy gun swung by wires, a1 measuring the distance the thrust move the gun backward. Shotguns and shotgun ammunition ré quire a different method of testing. Th performance of a shotgun is judged b the “pattern” or distribution of the p« lets on a large piece of paper or whit: washed steel plate, and on the penet: tion given by the pellets. The standa: distance for pattern testing is forty yard and the standard circle is thirty inches | diameter. A full-choke gun should thro seventy per cent or more of its charge int this thirty-inch circle. A third test of shotgun performance of more modern type and is more difficul' this is to determine in how long a colun the shot travels from muzzle to the mar Some guns and some loads tend to “strin; their shot in a long coiumn. The fin “pattern” does not show this stringing b: cause all of the pellets eventually arrive the paper, but with a fast-flying du crossing the column, only a few of t! shot would strike it because of the nu: ber lagging behind. Tests showed tl with some loads and powders, the sh:

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POPULAR MECHANICS 805 imn was as long as fifty feet when the ing pellets had reached a point sixty from the gun. lodern developments in progressive- ning shotgun powder tend to reduce stringing, and thus create a much deadly load, although the pattern rd and the penetration rack showed sorts of powder acting about the e. Neither board nor rack could show shot stringing, which is told by scien- ipparatus. ine method of detecting stringing is to the gun at a rapidly revolving disk of re size. Obviously the pellets lagging ind strike the disk at a different spot m the leading pellets. The speed of the being known, it is easy to calculate far behind the later pellets were trav- ng. Incidentally, the whirling-disk eme was used for testing ammunition ended for airplane machine-gun .in which the gun had to e in the intervals be- een the whirling peller blades. Obviously, if the charge was late, e bullet might ike the blade of propeller. Am- unition for this rpose was fired at rev olving disk if the shots in e “burst” occu- d morethana rtain sector of disk, the lot of munition was wn out as be- r dangerous. Inspecting Screen after Shot, to Determine Bul- let's Angle of Departure on Long Flight, and Preparing the Mann Rest with Special Tele- scope for Trial Shot This Is an Improve Support, to Hold th: Special Rifle Barrel When Firing, and Is So Accurately Adjusted That if the Ammunition Were Perfect and ths: Wind Didn't Blow, Bul- lets Could Be Put on Top of One Another at Half a Mile; Below, Measuring the Grou»s to Compute Final Re sults in Ammunition Tests

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806 Windmill with Upright Can- vas Sails Is Geared to Throw More Machinery in Motion When Wind Increases _ ae

WINDMILL WITH CANVAS SAILS DEVELOPS GREATER POWER Said to be capable of developing from five to twenty horsepower, a windmill rigged by a western inventor has four upright canvas sails, each seven by fifteen feet, instead of the customary rosette- tvpe of wheel. The sails are supported from spreader arms fastened to a center pole, and are about fifty feet from the ground. Theoretically, the canvas pro- pellers are supposed to convert seven- eighths of the velocity of the wind into power, but actually they pull only during three-fourths of each revolution. The center shaft is mounted on a universal joint to avoid absolute rigidity and to give a certain amount of flexibility to the bear- ings. An advantage claimed for this ar- rangement is that a comparatively simple superstructure is required, all the power- converting machinery being on _ the ground.

POPULAR MECHANICS The mill is regulated to increa ing winds, not by taking it out « the line of the breeze, as possible with a wheel, but | adding to the load iftstead « diminishing the power. T} is done by means of a seri: of trips actuated by the win They automatically add ad ditional pumps or motors the velocity of the wind i: creases, and. release them the wind subsides. PLANTS’ HEARTBEATS SHOWN BY SCIENTIST With the aid of carefull adjusted instruments whi he has invented, Sir Jagad Chandra Bose, an Indi: scientist is reported to ha demonstrated the “heart beats” of plants and to ha solved one of the questior that has’ puzzled schola for many years, why s flows upward. The “heart was located by means an electric probe in ci: cuit with a sensitive ga vanometer. . The prol was introduced step b step across the stem < the plant until it came i contact with the pulsat ing layer. This produce an electric respon which was recorded. 1] scientist is said to ha discovered that each active.cell, while es panding, absorbs water from below at expels it upward during contraction. H likens the heart of a plant to that of t! elongated organ in some of the lower ar mals, such as the earthworm, and declar that the life mechanism of plants is sim lar in many respects to that of living cre tures. By means of an amplifier t! plant’s heartbeat was measured and fou to be less than a millionth of an inch. specimen’s reaction to chloroform w demonstrated to an audience by causi! the apparatus to throw a beam of light « a screen. The drug at first greatly stim lated the plant, but this result was fi lowed by a death spasm, shown by t'! rapid fluctuation of the light beam unt it finally came to rest. According to t investigator's experiments, inorganic su stances also exhibit fatigue similar that of muscles and this is removed a period of rest.

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Where Men Do the Work of Machines . Industry Still Lags in Haiti; ; Above Is a Native Cane Mill, LT Operated by Ox Power i atl LT Ci ya } {) h a Native Tinsmiths Work in the Open and Use Discarded Oilcans for } Material; These Men Are Making Cups, Graters and Funnels: at the r Right Is a Native Carpenter, Using His Modern Saw Backward a e al Ly t] Al . , ire . . : Ed fi « Skilled Labor in a Native m - , : Woodworking Shop; the Man at the Large Wheel in re the Background Furnishes t} Power through a Rope ul Ww $11 Ee ¢ m f\ t] int

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808 POFULAR MECHANICS SAFETY LIGHTS IN PAVEMENT PROTECT PEDESTRIANS Flat-Faced Pavement Lights, to Mark Safety Zone at State and Madison Streets, Chicago So that street safety zones can be plain- ly distinguished at night, electric lights with flat surfaces, flush with the top of the pavement, have been installed at a busy intersection in Chicago. The lamps also help to identify the area in the daytime, even when not lighted, as the glass lenses form a distinct contrast to the dark paving. CURIOUS “ONE-MAN” TRADES Nearly all professions are overcrowded but there are a few occupations with only one follower, so far as is known. An Eng- lishman, in the census re- turns, stated that he was a walrus-moustache col- lector. The hairs which are exceedingly thick, are hall used for making tooth- . ‘ picks. London has only oa F ili ctri one moss gatherer. Ho rom Oil Dishes to Brilliant Electric pushes a wheelbarrow twice a week tx place several miles from the city whe he collects fresh moss and sells it for de orative purposes. An American wom makes a business of giving suitable nam: to babies. Only one man at a time in tly subtreasury at Philadelphia is said know how to stack bags of coin so the will form a solid wall and not fall dow: with possible injury to persons near | When he retires, he-teaches the secret | someone else. Not long ago, Londo: list of tradesmen included a professior “champagne disgorger.” His task was | remove sediment without losing any the wine. The bottles were placed ups down in a rack to permit solid material collect on the corks which were then e tracted in such a manner that the sediment was thrown out but none of the cha: pagne spilled. There is but one wom veterinary surgeon in England and, wu tila few years ago, only one Englishm pursued the trade of making wicker ar: chairs for dolls. Another little-know: occupation is that of breeding toads to s¢ to gardeners for destroying insect pest For thirty-six years, a man was employ: by a British factory just to strike match¢ to test them, and London has a man w! sells asses’ milk which is highly prized | some for its nourishing qualities. MAN’S PROGRESS IN LIGHTING SEEN IN LAMP EXHIBIT Some twenty-five centuries of hun progress were visualized at a glance in exhibit of lamps displayed at the Gener Electric company’s plant in Newark, N Successive stages in artificial illumi: tion were shown, from a crude she!) shaped container in which oil and w were burned about 600 years bef: Christ, down to the electric lig of today, represented by a bu of 30,000 volt ly fees Bulbs, the Story of Man’s Developm« of Illumination at a Glance

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volt pre POPULAR MECHANICS R09 ll se A oy ae. Harris & Ewing Part of the Easter-Monday Egg-Rolling Crowd on the Rear Lawn of the White House, When Thousands of Gayly Painted Eggs Are Rolled down the Hill in the Background Every Day a Holiday at the White House There’s Always Company Arriving and, to Add to the Festive Atmosphere, Comes a Constant Stream of Gifts (PRERES a place in the United States where every day is a holiday and where the Christmas spirit, at least that part in- olved in receiving presents, flourishes 365 days in ordinary vears and one more in eap year. The place is the White House at Washington and the recipient of all this attention is the president of the United States. rhe holiday spirit is not his choice or desire, in fact it sometimes interferes seri- usly with his work, but when virtually every visitor to Washington insists on a all on the chief executive he perforce be- omes a party to the celebration. Anyone ho regrets that Christmas and birthdays r other gift-giving occasions come so sel- lom may envy the president’s annual crop ot presents, which runs around 2,000 or so vear, with rarely a day passing without nywhere from a few to a couple of dozen rriving. And the list of gifts covers bout everything from animals to framed oems. Kangaroos, clothes and walking sticks ; pocketbooks, pictures and prunes: toys, tools and tobacco—the list of things sent President Coolidge in the last year is al- most endless in its variety. It takes a special clerk to keep track of all the gifts and see that the donors receive the treas- ured note of acknowledgement on the White House stationery. Not all gifts are accepted. If the White House suspects an effort is being made to use the president for advertising purposes, the present is politely rejected. Last fall President Coolidge declined to accept an apple pie from his own home state Ver- mont because his name might be thereby linked with publicity for an eat-more- apples week. More than half the gifts received by the president in a year are books. Some are sent by publishers, some by the authors, and many come from individuals who have read and enjoyed a book and pass it on to the occupant of the White House in the hope that he may find the same en joyment. Framed mottoes and poems ar-

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810 POPULAR MECHANICS rive by the dozens each year, most of them from women. Photographs and drawings of the president and pictures of babies named for him constitute another large part of the gift shower. Fruits, groceries and household supplies arrive in wholesale lots from admirers every week. The Thanksgiving and Christmas holidays always bring from one to a half dozen or more enormous tur- keys. Housewives who pride themselves on their jellies, their cakes or their beaten biscuit send generous samples, and farm- ers pick their choicest produce. The idea behind many of the gifts lies in news stories about the president. One day he advised a delegation of schoolboys to wear suspenders and as a result himself received some six dozen pair. His elec- trical horse attracted quite a bit of atten- tion, and a manufacturer immediately brought out a children’s size exerciser and sent several dozen to the White House with the request that the president give them to Washington children at Christ- mas. On his vacation in Vermont Mr. Coolidge tried his hand in the hay field, and a gift of a pair of overalls and a rake shortly followed. He tinkered a bit about his father’s farm, and the postman shortly delivered a saw and a screwdriver With the perpetual tide of callers, wh make every day an event at the White House, it takes a well-oiled machine to keep the business of the government run ning smoothly. The president must at tend to his office, meet all delegation pose several times a day for his photo graph, surrounded by the delegates, de liver speeches from the steps to more important committees, shake hands once a day with all comers, meet distinguished visitors, confer with the cabinet, and in between find time to eat and take exercise. Despite all its ramifications, the busi ness of the executive mansion moves so smoothly and mechanically that the thou sands of visitors are rarely conscious of the behind-the-scenes side of White House life. Easter is the most crowded period ot the year in Washington, with thousand of school children and teachers spendin the vacation there sight-seeing. The cit is at its best then, with the famous Jay anese cherry trees in full bloom, and th: egg rolling to see. All in all, life in the big white mansion is a fairy-story existence in which week days never come, but it is known that ey ery president soon begins to long for a bit of quiet and peace. © Harris & Ewing President and Mrs. Coolidge Receiving a Delegation of Wounded War Veterans at a Garden Party for the Soldiers Receiving Treatment at the Hospitals near Washington

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POPULAR MECHANICS 811 — oy é ‘7 P’ i - ‘* id oo ‘as 5 x ce - € ee ae a - _> st = aod) ‘ ’ %'« a4 « Re ¥eu “SL ne 7 wy - Wee . 4 > “Ss, ana . | ee Ps os oa Ie ‘ ; > a a ia ~ 2 a ; 5 mae 7 nail ;_ a ee While Natives Gather the Eggs in Crates and Wheelbarrows, the Big Birds Walk Unprotestingly among Them, Apparently Unaware That Their Nests, Exposed on Rocks, Are Being Robbed rONS OF BIRDS’ EGGS GATHERED FROM PACIFIC ISLAND Natives periodically reap a rich harvest albatross’ eggs when they visit the little ind of Laysan, one of the Hawaiian roup in the middie of the Pacific ocean. iterally tons of the eggs are picked up at ne gathering. They are shipped to mar- ets on other islands near by. The birds re generally too slow to catch fish, but e on small shellfish and can swim and with equal facility. Their “singing” is id to bear a close resemblance to the raying of an ass APPLE-TREE DISEASE TREATED WITH MERCURY COMPOUND Development of a method for the con- rol of crown gall, a disastrous disease that ttacks root-grafted apple trees is report- | by the department of agriculture. The stem involves the use of a recently pre- pared organic mercury compound which said not to injure the roots of the trees. n experiments conducted during 1925, of 619 grafts treated, little more than six er cent were afflicted with galls at dig- ing time, while the same number of un- reated specimens showed the disease in uch larger proportions, almost thirty- ree per cent of the lot being infected. n handling the trees, the experimenters ed precautions similar to those prac- ced by surgeons. Implements were care- sterilized and cleaned with disinfec- int, for the disease is caused by a germ. is believed that the new remedy prom- es savings of millions of dollars annually. the gall commonly causes losses of twenty-five to fifty per cent in grafted apple trees, and sometimes as much as ninety-five per cent. VIOLIN PAD OF SPONGE RUBBER EASES PLAYER’S POSITION Readily adapting itself to the shape of the neck and shoulder, a cushion of sponge rubber to support the violin, enables the player to assume an easy position, pre- vents fatigue and, in the case of beginners, helps them acquire correct posture and bow handling. The cushion slides back and forth on a movable arm, which is piv oted to a small bracket attached to the Upper View Shows Cramped Position of Play- er without the Violin Support; Lower with It in Place, Per- mitting Greater case chin-rest mount so that almost automatic adjustment is made to any style of play.

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812 POPULAR MECHANICS — Basket of Smelt and Scenes While Taking Part of the Annual Run from the Cowlitz River, Washington; the Fish Ascend Fresh-Water Streams for Spawn- ing in Such Numbers That They Are Easily Scooped Up with Basket Nets; for Years, Little Use Has Been Made of Them, but Packing Plants Are Now Salting and Shivping Them to the Orient

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POPULAR MECHANICS 813 MELT PRESERVED BY SALT ARE RADIO CABINET AIDS THE DEAF SHIPPED TO THE ORIENT For many years, fishermen have been plexed to find use for the billions of ‘It that annually ap- BY SOUND VIBRATIONS Radio has been adapted to the treat- ment of certain forms of deafness in a ir in the rivers of the icific northwest for the iwning season. They me in such numbers it they can be easily ight with scoop nets persons standing on e banks, but while con- erable quantities have en shipped to the city irkets, the great bulk the run has never been lized. Recently, a new lustry has been created one district in salting packing the fish for pment to China, Japan other parts of the ent. The first pack cregated 500 tons, and’ ins have been made for tension of the indus- The smelt, in size | appearance, resemble — J er trout. The meat white. oily like that of Top of Radio Sound Amplifier, Showing Controls, Tubes and Meters Which salmon, and there are bones. About six of the fish make a entiful meal for one person. SHOE-SOLE PAD FOR BOWLERS PREVENTS SLIPPING Quickly attached to ordinary street oes, a durable pad, patented by an east- rn inventor, pre- ents bowlers from ipping, saves the oes and makes urchase of an ex- ra pair unneces- iry. It is securely eld by tabs and a ort strap, and in readily be ad- usted to widely irving sizes of oes. A pair of the pads occupies little ace and can be carried in the pocket. @ The Popular Mechanics’ Bureau of In- rmation offers its free service to all iders of our magazine. Names and ad- resses of manufacturers and dealers in rticles described will be promptly fur- hed by addressing the Bureau. Indicate Volume; Phonograph in Front, to Furnish Music for Test cabinet which amplifies sounds. The in- tensity of the tones can be widely varied to suit the needs of the patient, who wears headphones and endeavors to hear music or speech from a phonograph record or the human voice spoken through a tele- phone transmitter into the cabinet. The vibrations stimulate blood circulation in certain parts of the ear, help to loosen the small bones and muscles if they are too rigid, and thus aid nature toward the res- toration of normal hearing. Several per- sons may receive treatment at once with this apparatus, and an additional advan tage is that a deaf person may hear the sound of his own voice by speaking through the mouthpiece himself. LINERS TO CARRY AIRPLANES TO SHORTEN VOYAGES Two steamers for passenger service be tween the United States and ports on the Mediterranean are to be equipped with facilities for carrying and launching am phibian airplanes from their decks, ac- cording to news dispatches. The innova tion will permit passengers to reach their destination as much as two days before regular schedule time.

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Time and Money-Saving Tools Funnel Top Transforms Fruit Jars into Meas- ures; While Spout Per- mits Pouring without Spilling; Tube Is Handle and Air Vent Is the Egg Good? Mir- ror Cup, Below, Quick ly Answers the Ques- \ tion; a Clear Reflection ag = 7 from Glass Indicates , Unspoiled Egg; Spots or Streaks, Doubtful Glass - Tipped Caster Permits Sliding Fur- niture over Floors without Damaging Wood or Rugs Women Who Make Their Own Clothes Can Mark Their Skirts without Assistance, While Wear- ing Them, with Simple Arrange- ment at Right Anyone wishing further informati 814 Clamped to the End of Or- dinary Toothbrush, an Auxil- iary Set of Bristles Helps in Cleaning Artificial Sets

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Se — at for Woman’s Workshop in Home Unpleasant Odors in the Refrig- erator Are Absorbed by Sub- stance Held in Wire Cone; Heat- ing Renews the Material On This Improved Gas Range with Special ——3 Cooking on Cast- Iron Top, Baking an Heating ’ Water in Coil Can All Be Done at Once with Only One Burner; It Utilizes Much of the Heat Lost in Ordinary Range Lightweight Baby Car- } riage Has Package Car- rier in the Back; at Right, Spring-Wire Catch on Pole Keeps Clothesline in Place Even When There Is a Heavy Wind ——— —_ - btain it by addressing Bureau of Information, Popular Mechanics Magazine, Chicago

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816 POPULAR MECHANICS be duplicated on a sci- entific basis by interpre tation of the fossils dis covered in coal beds an in the layers of rock ove: the deposits. Form, tex ture and size of plant and trees that flourished ages before history wa written by man, are re vealed in the natural rec ord left in silts that hard ened into stone, “freez ing’ the imprint of ferns and leaves as an album presses specimens placed between its pages. Prof A. C. Noe, of the Uni versity of Chicago, vi sions a typical coal land scape of that early age a an enormous Swamp stretching over a terri tory now occupied b several states. Vegeta tion was prolific and tropical in character, but practically odorless and monotonous in its pre vailing greens, yellows and browns. Trees bear ing tufts of narrow leaves and covered with bark that had scales like those of an alligator’s skin rose to a height of 100 feet. Their only liv ing relative today is the Arrow Points to Automatic Holder in Place at Top of Door and Entire Brace Is Shown Below; Slight Push on Door Releases It AUTOMATIC HOLDER FOR DOORS PREVENTS SLAMMING Easily adjusted and sure in operation, automatic holders for the garage doors prevent damage to the car or to the doors themselves and make it unnecessary to use bricks or other makeshift props. A latch engages a catch to secure the doors, and in closing them the leaf is opened a trifle wider, permitting the catch to be released. This arrangement prevents the wind from closing the doors. STORIES OF PREHISTORIC LIFE TOLD IN COAL BEDS Scenes from Jules Verne’s “A Trip to the Center of the Earth” and what the English professor saw as he journeyed down one of the craters of Iceland and out through a volcano in Italy, can almost small club moss with which gardeners trim bouquets and flower beds. The trees propagated by spore which contained oils and other fats as food for the young plants. Cannel coal today is rich in oil because of the quantity ot these spores in it. This was also the age of the tree ferns, similar in appearance to those now found in New Zealand and the South Sea islands. The absence of regu lar flowering plants was a distinguishing characteristic of the period. They did not develop extensively until centuries lavet when pollen-bearing butterflies and bee appeared. No mammals existed, reptile were small, and millions of years elapsed before the first great dinosaur was born lhe swamp waters were filled with fish and odd crustaceans; oysters and clam could be found in abundance, while hug: dragon flies, some with a wingspread « thirty inches, flew through the air. Afte thousands of years, the sea rushed in and covered this huge swamp where the great

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POPULAR MECHANICS 817

ci- e elds of the east and IS iddle west are now nd developed. Shales e1 d by this inunda- X preserved some of it idence of the form- ec] amp vegetation. as er long period e ed and the sea re- Cc giving opportunity d second swamp and z vegetation, but it ns ned, burying the m crowth and forming ed er coal seam. | M REACTION TO FEAR f MEASURED BY 2 EYE PUPILS Ip it emotion can now “j lescribed quantita- Smashing through Pane of Plate Glass at Sixty Miles an Hour, Motorcyclist = ‘ A Received Only Two Small Cuts on Face D1 is the assertion of aa cientists at Columbia university who CYCLIST RIDES THROUGH GLASS 1 een conducting an interesting series AT SIXTY MILES AN HOUR ut with human subjects in an effort 1d asure their reaction to fear. While Crashing through a huge pane of glass e erson under observation is seated in erected within a frame support, a daring \ ened laboratory with his hands fit- English motorevclist suffered only two r nto cuffs, a pistol is suddenly dis slight cuts on his face His speed was “ d close to his head or a noisv auto sixty miles an hour, but cameras “stopped” th horn is sounded or he feels the the action almost perfectly, even to regis : hat correlation. amine Interior of Mummies by X-Ray Photographs be 9,000 years old.

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S18 CANADA TO HONOR WAR HEROES WITH NATIONAL MEMORIAL Model of Proposed War Memorial to Be Erected for Canadians near Ottawa In commemoration of the sacrifices and services of Canadians during the World War, a national memorial is to be erected at Ottawa. The prize-winning design, se- lected from plans submitted by artists and sculptors from all over the world, shows a procession of soldiers passing through an arch as though in triumphal celebration of victory. The work will cost approxi- mately $100,000, it is reported. The statue was designed by Vernon POPULAR MECHANICS taken as a measure of the brightne the paint. The chemists say that ability of a paint to obstruct the trans sion of visible light rays and its abilit obscure the surface upon which it is plied, are really the same thing. Du: the tests, it was discovered that whe small amount of dark pigment, suc! carbon black or Prussian blue, was a to white paint, there was a much gr: increase in the “hiding power” of the than decrease in its brightness EARTHQUAKES PROVE BLESSING INCREASING FLOW OF SPRINGS While the recent earthquake in S Barbara, Calif., did great property « age, it left an unexpected compensat by increasing the flow from subterran: springs. The waters are filled with 1 erals and are considered of medi value. Scientists declare that the ] nese earthquakes likewise have been bk ings in disguise, for they have been strumental in exposing deposits of valua ores or have made access to them poss STUDY ODORS INSECTS PREFER IN ORDER TO POISON THEM With the aid of apparatus which sh which odors insects like best, a scier in the departmént of agriculture de bait for traps, or for poison dishes destroy various pests. He has discove that insects of many kinds are guided the sense of smell in selecting food prepares lures likely to attract them. ps March of Kent, England. WHITE PAINTS ARE REALLY GRAY TESTS SHOW That all our so-called white paints are really grav, is the conclusion of chemists at Cornell uni- versity after a series of tests. They found that light was absorbed to a | slight degree, so that the paint reflected less than was shining upon it. The ratio between the | amount of illumination thrown back and the amount reaching the me = i ) it paint surface, the experi- menters declare, may be With This Complicated Apparatus, Scientist Discovers What Odors Vari Insects Prefer So That He Can Prepare Poisons

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ie 215 nown, and used, for ages. POPULAR MECHANICS 819 The Romance of the Molders of Stone Concrete Covers the Land and Sails the Seas in the Form of Ships, All in One Generation ROM a crude and little used product irdly thirty years ago, in the days hen the automobile was young, cement leaped to the fore as the world’s st amazing building material. Hard- day passes but some new use is und for poured and molded stone, one the latest being the construction of au- obile bodies in Europe. [hirty years ago cement had begun to ipplant stone slabs for sidewalks, and e government built a small barge- nal lock of it out in the Illinois prairies. e material was not new, but had been Foundations the Roman temples, made of poured nerete, are still standing long after time the elements have cracked and felled e marble columns and arches. The walls the House of Augustus, poured in 36 ., Show every grain of the crude oden forms in which they were molded. Concrete really came into its own about e time that the automobile made better ds necessary, and at the same time en- ( neers searching for a new, strong and lckly erected factory-building material irned to cement for the answer. The steel-frame skyscraper had begun to revo lutionize building practice with the possi bility of a self-supporting framework, to which thin walls could be attached to keep out heat and cold and provide pri vacy. A few crude experiments in con crete construction, followed by the de velopment of special apparatus and the invention of reinforcing steel, started concrete on its way. From that rough start, one of the larg est industries in the country has grown. The invention of the rotary kiln, huge horizontal cvlinders, hundreds of feet long, in which the powdered rock can be cooked into cement, speeded up produc tion. Enormous crushers mash the rocl brought from the quarries, the big kilns subject it to intense, fusing heat, and crushers again reduce the caked cement to its final powderv form From the powdery dust, mixed with water, sand and gravel and reinforced in many cases with bars of steel, come houses, offices, factories, roads, bridges. dams, canal locks, breakwaters, amphi theaters, grain elevators, coal pockets, barns, silos, chimneys, troughs. fence

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820 POPULAR MECHANICS — “a Right, Footing for Sky- scraper Pillar, with Heavy Reinforcing in Place; the Concrete Base Slab Rests on 168 Concrete Piles Driv- en Down to Solid Rock; Below, the Monolithic Floor of a Reinforced-Con- crete Hotel Being | Smoothed Out Before the J Cement Sets Sixteen-Story Reinforced Con- crete Building, at Left, Is One Solid Piece, Insuring Greater Strength Than Old-Fashioned Construction Methods: Above, Tamping the Cement Down 3 7,

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ee ge | — SS Sills POPULAR MECHANICS 821 ornamental light posts, telephone benches, sundials, bird baths, 's, urns, pedestals, lawn rollers, laun- tubs, statues, tombstones and even er cofttins. ured as a liquid, it becomes, in a ter of hours, a rock that grows hard- nd harder with age. It resists both ind water and, when properly made, ds up under the’ roughest treat- t. On the sea it is represented in ships, and it travels on land as crete freight cars. e amount of it used in the United tes last vear was sufficient to have thirtv-four replicas of the great mid of Egypt, which 100,000 slaves nsumed twenty vears in ding, or a total produc- for each slave of thir cubic yards of ma- ry in twenty vears. mpared to that, irking with uid stone and \dern meth- five cubic ls can be now for ch man the crew in ten-hour rking day. Huge Reinforced- Concrete Tile Sec- tion and, Left, Spray Gun Being | Used to Coat a Fence with Liquid Stone Roa d S alone. during 1925, ab sorbed some thing more than twelve and one tenth million cubic vards of concrete pay Zs ing, but the production ot automobiles more than kept pace with the extension of the hard highwavs, so that the immense sur face of roads laid was not much more than enough to stand the new cars on. The output of roads equaled three cubic yards for each car built during the vear. The total consumption of con crete last year, according to esti mates of the industry, was 103,000 0OO cubic yards, which fell only a few million yards short of enough to have duplicated the famous Great Wall of China, a job which took 300,000 soldiers and all the convicts and dishonest officials in the em pire fifteen vears to build With modern concrete equipment the 300,000 soldiers alone could have mixed enough liquid stone in eighty davs to have built the wall. Boys at Mooseheart, Ill, Home of the Moose Orphans, Learning to Model Attractive Ornamen- tal Pieces from Ce- ment, Finishine with = Sculptors’ Chisels

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822 POPULAR MECHANICS ment or using grat particles as an aggreg any tint desired obtained. The new material, sides being plastic, be handled in sucl wide variety of ways t its applications are most endless. From ing poured in forms molded into blocks, it now sprayed on wit! compressed-air gun less time and with bet results. Coated 0, wooden piles in this and held in place metal reinforcing, it p1 can Spraying Mine Walls with Cement to Prevent Dust Ex- plosions, Above; and, at the Right, Movable Forms Used to Shape Concrete Flume because of its plastic features that concrete has become the premier building material of the age. Irom the crude cement blocks of a decade ago to the poured stone of the present, which looks and wears like granite, is a long step in one di- rection, and working in It is a reverse way, the for- ward step from pains takingly carved granite statues of the past to the colossal cement-cast “Fountain of Time” of Lorado Taft is an equally great advance. Real stone which can be carved with ease and which improves with age is rare. The delicate tracery that embellishes the famous monastery at Lisbon, erected as a tomb for the discoverer of the sea pas- sage to India, was made possible by a supply of chalkline limestone which carved as easily as chalk itself, but which, wheh exposed long to the air, became hard as rock. With modern cement methods, the same effect can be ob tained in a fraction of the time, with day laborers instead of skilled artists, and in addition, by mixing color with the ce- tects the piles from the ravages of destructive teredo. In building construction it has b« beams or m used for poured columns, girders rising twenty stories above the ground, reinforced only 5 slender network of steel bars and w: and even the lofty steel-frame build: has its iron pillars incased in cement. Cement railroad ties are being t! out to replace wood, and the president one big railroad—the Pere Marquett« predicts that the railroad of the fut will have an entire roadbed of cemé giving a stronger and more even sur! than gravel fill, and permitting tra equipped with ball-bearing axles, to with almost the speed of airplanes.

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POPULAR MECHANICS 823 OUR THOUSAND LAMPS DAILY HOW PHONES HAVE IMPROVED GOVERNMENT’S DEMAND SHOWN BY OLD RECEIVER . \lore than 1,500,000 electric lamps are Included in the semicentennial exhibit rchased by the United States govern- of the telephone company in San Fran- each year, or over 4,000 daily, fo: manifold illuminating systems of pub buildings, battleships, laboratories, ‘es and warehouses. The demand in les almost every size of light from tiny s for the lamps used in surgical op- ons to the big ones for searchlights les of every type of light purchased tested by the bureau of standards, ilso does similar work for private NEW CORE FOR “LIVELY” BALL TO IMPROVE GAME make baseballs more uniform in and flight and to stabilize hitting, rk-cored sphere designed for use of National league this vear has two of rubber instead of one. It is ex- ted that this will keep the “live” center m getting out of shape so easily, there- Today ae yt oy Fy ye ee - preventing exposing more rubber on e side than on another and the uneven cisco was the first receiver made by ing that is likely to result. The so- \lexander Graham Beil. Its cumbersome ed “rabbit ball” has been widely dis- size, exposed wiring and unhandy shape sed in sporting circles for the last four are in sharp contrast to the trim units de .as it has had an important effect on veloped during the past fifty vears of number of home runs and the general telephone progress. luct of the game. Walter Johnson said on this subject. “No two balls DAYLIGHT GLASSES FOR DYERS be made exactly alike; it can’t be AID IN COLOR TESTS ped Sometimes the same ball will e two or more degrees of liveliness, de- To enable dyers and textile workers of ling on the side on which it is hit. various kinds to detect the true shades | e cork center is alwavs flattened unin- of delicate colors under artificial lights, —) ionally in manu turing it, causing rtain sides of the ubber coat. ch is pressed a sphere, to tain more rub- a Vienna engineer has devised spec tacles with lenses of a special kind o glass through which the effect of day oa light is obtained re Tr \ ey gardless of surrounding illumination. They are considered a simple ' than the other means of solving the “a es. If the im problem than lamp - of the bat with globes of this kind 1 inces to meet of glass, To! the prod di ball upon the hh uct is costly. It is made where the so that it filters out the ri rbe r is th e . excessive red and vel it kest, it sails low rays present #9 ter and farther in most forms ot me n would be the artificial lighting, , if the ball is restoring the bal .f in a place ance of blue and =i ere the rubber violet rays and r ppens to be a the desired day Baseball Core at Left Keeps Shape with Two Coats of nner.” Rubber; at Right, Result of Only One Coat light elect.

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824 MOVIE TICKER FOR BROKERAGE SAVES MARKING BOARD Sparing the time lost and the mistakes made in chalking the reports on a black- Reading Stock Quotations from Movie Ticker; Figures Are Projected from Transparent Tape Directly from Receiving Instrument movie ticker in use at the Chi cago board of trade shows the stock quo- tations directly from the receiving instru- ment on a transparent screen. Letters and figures are projected from a specially pre- pared tape instead of the usual paper rib- bon. The characters are easily legible, be- ing several inches high and, as the “film” moves from right to left, the latest as well as several of the preceding quota- tions are visible at the same time. board. a POISON WAR AGAINST COYOTES DOUBLES NUMBER OF SHEEP Phat the poison campaign waged against coyotes and wild cats in a California coun- ty is producing good results is seen in the fact that the num- ber of sheep has doubled during the past two years. This largely due, off- cials say, to compar- ativé freedom from the depredations of the wild animal kill- ers. Before the poi- son war was started by the and county departments, is Bolt Cut Away to Show Ball-and-Socket state, federal one stockman Valve to Regulate Flow POPULAR MECHANICS alone lost 400 sheep out of a herd of 9,5 during the summer period of four mont Last year, only fifteen out of a flock 7,500 were killed. Where some 200 lan were lost to coyotes and other maraud: among 4,000 ewes, o1 four were reported kil aiter the poisoning wor Ranchers say that tl are now able to rai turkeys, pigs and chi ens on the open rans with almost no lo whereas inclosures necessary before. HARNESS GEYSERS IN ICELAND TO GROW GARDENS Visions of Iceland Europe’s kitchen gard may become a reality, a degree at least, geysers there alrea have been used in su plying laundries with |! water, and it is now pr posed to pipe the fl under the ground a: utilize the heat to stim late the growth of plant and vegetables. This already has be: done in greenhouses as an experime Potatoes, planted earlier than possi! outside, developed much more rapidly, ai flowers have been grown with success AUTO BOLT WITH OILING VALVE IMPROVES LUBRICATION Oil distributed evenly and in proper amounts to parts of the automo! chassis from a special type of bolt 1 on the market. The lubricant is « trolled by a ball-and-socket valve in bolt, situated between the oil-cup re voir and the bearing. This valve vents escape of the oil when the cat standing _ still, when it in tion, there is s cient vibration cause the ball move, allow! enough oil to out to preserve necessary film proper lubricat The design is su especially to ki bolts and to those located in springs tie-rods. 7 is 1S the Oil Compartment and

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( e e n be bought for $2 lo make it easy for Radio- Battery Charger for Farm Lighting Plant By E. J. BACHMAN HARGING the 6-volt radio storage battery from the 32-volt farm-light- plant is a simple matter if a suitable tance is used in one of the connect- ‘ads, and the polarity of the connec- is correct. It is not a good plan ip off the A-battery supply from the itself as many try to do. A good It. radio storage battery costs very and will last a number of vears if erly maintained. Regular charging ecessary for best results, and as very farms are equipped with the current ly necessary to use the standard rging apparatus, many farmers have ted themselves to sets using the small cell tubes. The storage-battery tubes oid ee 7 board is 1 by 6 by 6 in.; a piece of sheet or stovepipe iron, 6 by 24 in., is laid out as shown in the blueprint diagram, and the holes are drilled or cut for the meter, bolts, nails and ventilation. The metal sheet is then bent on the dotted lines and fastened to the base with small nails Rubber-headed tacks are used under the base for feet; after the sides and have been assembled, mount the element with two 4% by 2-in. stove bolts and nuts, that it stands clear of the back and sides, to allow dissipation of heat. The element will warm up in use, but does not get hot as when used in the electric iron. The ammeter is of the common au tomobile-dash type, with a 20-0-20 scale, base sO so e better results, and farmer who is iso- from broadcast- stations requires the efficiency he get. ' iN 1 “in AUTOMOBILE \\ A TYPE home constructor, MAMMETER Plant; less, met the re- red specifications, when connected as wn inthe diagram. The element was osed in a neat sheet-iron box and an to-type ammeter gives the completed Tt nit a factory-built appearance. The base- Broken-Out Section Shows the Instru- ments in Position and the Wiring so that it will show the flow of current in either direction. If it is marked charge,” “charge-dis these indica g resistance that can tions may be disre readily obtained in garded. e electrical shops is The two lower ter esirable. It was gert-mon minal lugs on the und, that the ele- mee 10 32-V CASE. heating element are ent from a 110-volt Fy SOCKET BATTERY CLIPS connected with a wire ectric iron, which Radio-Battery Charger for Farm-Lighting OT strip of metal, as shown in the detailed illustration: from this point an insulated lead wire is brought out through a rubber bushing, in the front of the case. to a batterv clip. This terminal will be positive, as shown in Fig. 4 in the blueprint diagram, so mark this clip with

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2@ On.0D POPULAR __— $$ $$ TO HOLES SPACED AS THOSE IN ELEMENT HOLE | a AIR HOLES FiG.2 + 32-V. LINE STORAGE BATTERY Above, Construction Details of the Sheet-Iron Wiring Details of the Completed Installation across. The upper terminal of the resist ance unit is connected to a short lead of in sulated wire and goes to one side of the ammeter; the other terminal of the am meter is connected to an insulated lead that is taken to one side of the 32-volt socket. The other socket lead is carried through the rubber bushings in the case and out to the negative \-battery clip: the details are clearly shown in Figs. 3 and 4. one part of the detachable plug into the light socket: the instrument must now be tested for correct polarity with the supply SCTeEW tlie clips to the Connect proper posts on the storage battery to be charged: while watching the ammeter short the pri with a piece of metal and note in which direction the pointer swings If to the right, then it must swing to the left when the plug is connected in the and the 32-volt current turned on. Should it swing to the same side that it did on the shorting test. pull out the plug and insert the pins in opposite holes. Shorting the plug in this manner will not harm any thing, as the resistance is Con necting the plug in the wrong direction momentarily, will not matter for the same reason. lhe main point to remember is line. ( mgs of the plug 1 1 socket reversing it in series MECHANICS “SHOLES FOR SOCKET BUSHINGS Box; that. to charge the battery, tl indicator must swing in the « posite direction to that in whi it swings when shorting the pi of the detachable plug. Poor Insulation Is Cause of Leakage To really for appreciate the chance the picked by the aerial before it reaches t!] set, and in the set before it can | built up to the point required phone or loud-speaker volume is necessary to of the minute acter of losing energy know somethi1 and impulses. amount of energy picked up f1 distant stations by the aerial is small that i feeble cl these verv delicate instru ments are needed to detect presence It is the function the radio receiver to amplify tl minute energy and convert it int mechanical power sufficient actuate the diaphragm of tl] phones or horn. It must nursed and guarded so that it wi flow along the path by which it to be built up. t To lose anv part Below, 2 ° * 9 of it will lessen the volume of the receiver and cause loss of sele tivity. Good insulation through the set necessary to cut these losses to a mit mum. The instruments themselves mu be of the correct design to prevent los in fact, for best results, it is ] YO al necessafy most to extremes in preventing tl energy to escape. Radio currents have tendency to travel on the surface of t conductors and insulators, so that tl presence of a little dust or moisture offer a path for escape. W ood, therefor is a poor insulator, as is any material « pable of absorbing moisture. Many tit wood subpanels coated with a black pat or finish, which invariably contains « bon in some form, are used, giving the 1 nute currents a chance to escape, The are plenty of good, cheap insulating m: rials for panels and subpanels, and the; should be used. Sockets of the “mu type have almost disappeared from tl! market; this compound contained condu tive material causing serious losses. Goo sockets are now made of high-grade insu lating materials, and are | losses are reduced to so designed tl a minimum @ Audio-frequency transformers shoul be mounted at right angles to each othe: and 4 to 5 in. apart.

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Oe eS OO es ae ee eS RE Eel POPULAR MECHANICS nding Weak Tubes in Radio Sets ny fans seem to think that they must quipped with an accurate tester to e troublesome tubes in their radio ts or tubes that are in need of re- | for proper emission. A practical od that has been used for some time, following: Obtain a new tube as an 1 in case of trouble. Remove the nd amplifier tube from its socket and, the switch cut in, move each tube ne position and note the amplification ne value it gives. It will not take to locate the tube which should be tivated. A tube rejuvenator is the investment needed, and the cost of extra tube is of little consequence. Repairing Audio-Transformers defective audio transformer is gen- remedied by substituting a new although the trouble could be lo- in the old transformer. It is dis- ed because the fan has an idea that e wire in it is ruined, or he does not to tackle the “miles” of fine wire. ever, very few feet of the wire have e tampered with to locate the break. trouble in most cases lies in the pri- and nine times out of ten not in winding actually burning out; and far the most transformers now in are the layer-wound paraffin-paper e, it is not difficult to locate the break repair it. The first thing to do is emove the core, leaving the primary secondary windings intact. A simple to locate the break is to connect one of a wire to a small needle, and the end to a dry cell through a pair of Iphones, the other post of the dry cell ¢ connected to the winding to be ex- ned. The needle is then slowly forced the end of the winding; if a click is rd when the point of the needle hes the layer of wire, the wire is un- ken that far. By continuing to push needle farther in until no click is the exact layer that contains the k can be located. If it happens to be the outside of the secondary, or the le of the primary, it can be repaired out much trouble. If it is near the ter, it will be necessary to heat the lings so as to soften the paraffin and e these windings apart at the break. is done as illustrated in the upper hand diagram. <A small wood plat- in with a hole in it slightly larger than defective layer is prepared, and the ted coil is placed over this hole. A » 827 cylindrical object that will fit the hole is then placed on the other end of the coil, and force is evenly applied until the wind- ings are telescoped apart.

~--FORCED OUT WITH ROD

LAYER THAT — CONTAINS BREAK oh ra

Locating Breaks in Defective Audio Transformers with Headphones in Series with a Dry Cell When repairing the break, use only rosin for a soldering flux, and in replac- ing the windings, take care to keep the wire from breaking. If half a layer or so of the coil is lost, it will make no differ- ence in the operation of the transformer. While rebuilding the core, if any trouble is experienced in getting all the lamina tions in place, try squeezing those that are assembled and then adding more to them.—Watson Brown, Iuka, Miss. Low-Rate Charger for Continuous A-Battery Supply

A low-rate charger designed for con- charging tinuous over long periods of time is es- pecially de- signed for dry-cell sets and storage- battery sets having rela- tively few tubes. The instrument charges both 4 and 6-volt \-batteries at about .55 ampere. and re quires very little attention. Operating di rections accompany each charger, giving time of operation necessary for the vari- ous types of sets. The charger can be so reculated that it can be left on continuous charge, if desired, thus keeping the A battery up to full charge all the time

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WOVE 2°ON 40 WWLIO oepf pas Sziuzsiive-s ; awauivé-v 7 oo LIOA-S% OML ; ee 9261 “AVN 110A-9 — BNIZVOWW SSINVHO3W YY INdOd YIAIZOIY INVYd-ONINMOY Ay ei0s-¥> JENL-IAld GIANNA S. AdaLLve-o" 4aASNIGNOD ‘a4aWw-t Wwisav aNnnous = | YwaSNIGNOD ONIONV VE 661 xn 1'a°@ “LINN YILIWLION

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— rri pyr Five-Tube Browning-Drake Receiver of Improved Design By GLENN H. BROWNING "ERY radio set listener desires a which is at the same time iently sensitive to receive distant sta- and selective enough to cut out in- rence and easily separate local sta- The signals received must also have tone quality If, combined with qualities, the receiver is easily built perated, it is most welcome to the ner. The receiver to be described is tive, sensitive and easily built and not perfect, is believed to be a step he right direction. he circuit is a combination of old and ideas, and depends for its efficiency on the design of the tuned rf. former used. This 1926 model of the known circuit also employs straight- frequency condensers, dials of new and a very efficient method of im- nce-coupled audio amplification. The broadcast blems involved were worked out by the ter and Frederick H. Drake, at Cruft ratory, Harvard university. The par- ir problem solved was the design of ned r.f. transformer, which would give greatest possible amplification when loved with the tubes now obtainable, result being, that approximately 90 ‘ent of the amplification calculated by thematics was obtained in practice. In circuit the tuned r.f transformer is | with a regenerative detector, so that stage of radio amplification suffices all purposes. he reader should understand that the pose of a r.f. amplifier is to build up le signals so that distant stations may ght. 1926, Popular Mechanics Magazine There is a limit, however, to the sensitivity of any receiver, for noise such as static and “man-made” interfer ence, may be louder than the incoming signals from a verv distant station. Then, no matter how sensitive the set may be, only a limited distance can be received be fore what is known as the static or noise level is reached. Thus, if we have a set which will receive signals up to this level. its sensitivity has reached the practical limit. In the quest for an efficient audio amplifier to combine with the r.f. part of the receiver, laboratory measurements were made on three possible choices, namely, two stages of transformer-coupled be received. audio, three stages resistance-coupled, and three stages of the impedance- coupled type. The latter was _ finally chosen, for, although it requires three tubes instead of two, onlv 90 volts of B battery are needed, and the quality of the received signals is practically perfect When tested in Popular Mechanics radio laboratory, this receiver had unusually good tone and range. The lavout of the receiver is verv sim ple. The UX-199 tube is placed between the two tuning units, and the audio ampli- fier at the right of the detector, making the leads short, especially those carrying the r.f. currents. The front panel is “6 by 7 by 24 in.; the subpanel, %6 by 8% by 23 in. T hey should be of bakelite o1 formica, although the subpanel may be of ‘46 in. wood if desired. Mount the in struments on the f panel first, as Iront shown in the front-view photo. Lay out Rear View of Completed Set, Showing the Method of Running the Wires above the Subpanel

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$30 POPULAR MECHANICS 1 the instruments on the subpanel as shown above and below. slack-spaghetti tub t tl by | | 1 bel Blacl hetti tul in the rear-view photo of the completed is slipped on the leads where necessary instrument and the _ full-page’ blue prevent shorts. The schematic diagra print diagram. It will be noted that the given for those who prefer it to the sir brackets on the first tuning-unit condenser plified wiring diagram. support one side of the subpanel, while the [It was found, with either a resistar or impedance amplif that the r.f. current « tered the a.f. circuit affected the operation AN VOLIMETER the recei\ er s | ight! mid seine a. mi {| a wD ame o- ~$— + wat soe giving a py A a eee ee 2 a tepals he tick =2k> Z"HOLE ZHOLE % HOLE speaker when the tict NOTE:-USE NO.20 DRILL FOR — Oo coil was advanced t ALL HOLES NOT MARKED FOR SIZE ge be J—ela— 5 owl for - This was elimin with a choke coil pla in series with the .1-mi condenser at the poi marked X on the scl matic diagram, and mu 24° PANEL LAYOUT URZOIA OR HIGH MUZO TUBES ae ahead OF mene in ters a me \ Mu sure " of amplifier than th ! . specified in the matet H list is employed. The 5 gMEG)) Gr = MES. Ta | * Mes impedaformers contait +-C+ —a™. -C+ -éF wowisel| Jocro1so || }woro1s0 choke coil and .1l-mi VPR | HENRYS HENRYS HENRYS condenser, and the ¢ tire unit is emploved Sscaalehceiasaall wssedorine tate | Lye —3 fm 6much the same mans OA-B- ° ° — Plies un, Te A ae as an ordinary a.f. trai ~ 2 ( va < RHEO 4106 OHMS rormer. onnection

SCHEMATIC DIAGRAM the C-battery are sho in the large blueprint d gram. This C-batter Above, Front-Panel Drilling Template; Below, Schematic Wiring Diagram for the last audio st and can be varied to other end is screwed to the frame of the’ the type of tube used. The new UX No. 2 jack. Brass machine screws, or in sockets, suitable for either the 199 or 201 verted binding posts, can be fitted to sup- tubes, are used throughout the set port the rear edge of the subpanel. The detector and amplifier tubes are the 201 pen diagram is given in simple detail type: HI-MU tubes can be used in on the blueprint page, all of the wiring be amplifier stages if desired. If a po

ing ots above the subpanel so that the tube is desired in the last stage, it is n various leads can be easily traced. When essary to provide an extra binding p:

wiring the set, however, it is best to run for the required 135 volts. The 1-n the leads under the subpane!l whenever condenser, marked “optional,” may convenient Che rear-view photo and the omitted in almost all cases where underpanel view show the leads bot! leads to the B-battery are short MATERIAL LIST 1 hakelite or formica subpanel, 3-16 by & by 23 in. 1 type 17 double Hayt voltmeter 1 bakelite or formica panel, 3-16 by 7 by 24 in 1 fixed mica con 0001-mitd 1 National tunin nit, Browning-Drake 1-Type-B 1 fixed mica cor 001-mid 1 Nationa! tuning unit, Browning-Drake 2-Type-B. 1 fixed mica condenser, .00005-mfd. 1 Yaxley (or similar type) 30-ohm rheostat 1 gridleak (try from 5 to 8 meg.). 1 Yaxley (or similar type) 6-ohm rheostat 1 gridleak mounting 1 Yaxley (or enti type) switch 3 National impedaformers (these combine an in 1 Rathbun, General Rad or X-L, balancing ance, .1-mfd. fixed condenser and gridleak condenser 10 binding posts General Radio UX sockets ] 3 1 con lenser, 1 mfd., (optional) 1 Yaxley (or similar type) double-circuit jack 1 "X-199 tube 1 Yaxley (or similar type) single-circuit jack 4 UX 201A tubes 1 fixed-resistance unit, 25 t oh The parts, as listed, will cost about $56.75

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se e@er*,. sav SMPMKE AICCNANICS JAR e@ZLiie POPULAR MECHANICS 831 ether or not it helps in balancing the eiver, can only be determined by ex- menting. The UX-199 tube is used . r.f. amplifier, as it is much easier to ince than the 201A-type, and gives ap- ximately the same results. The 33- resistor in series with the filament reduces the 5 volts erly built and skillfully operated, but the builder should not expect to get distant stations the first night. When the set has been constructed. the first thing to do is to balance it so that it will not reradiate. Connect the aerial, ground and batteries, and place the tubes ross the large tubes to 3 for the filament of small tube, so that the nm rheostat may be ned full on when maxi- 1m signal strength is de- ed. This rheostat can used as a volume con- so that local-station ength can be reduced lesired. \ verv short aerial, say, m 10 to 70 ft. including e lead-in, may be erected the receiver, and the shorter the aerial better the selectivity. The aerial uld be as high as possible, the writer ing used a vertical stretch of about 30 vith good effect. A short aerial should connected as shown in the large wir- diagram, and, if the longer aerial is ed, a tap should be made from the aerial to a separate binding post and the ng aerial connected to this post. This rangement, which is shown at point 2 the schematic diagram, keeps the dial idings more nearly together. lhe set may be adapted to a loop by sconnecting the first coil from the con- nser and connecting the loop to points and B, as shown in the schematic gram. However, a short aerial has re pick-up, although stations 1,000 es away have been received under fav- ible conditions on the loud speaker th a small loop. In fact, the writer has Front View of Instrument Panel eard, on a friend’s set, a station 400 miles ay with no antenna connection at all. his is very unusual, however. For ex- emely sharp tuning it is suggested that aerial lead be disconnected from the under crowded conditions in large ties, when local programs are desired. he set is capable of bringing in stations veral thousand miles away when prop- FIXED RESISTANCE. 251033 OHMS’ Under-Subpanel View, Showing the Fixed Condensers in Position in the sockets. Plug in the phones in the first jack, and tune in a local station with the two dials and the rotor, or “tickler” coil. Then turn the 30-ohm rheostat off. leaving the UX-199 tube in the socket: set the balancing condenser so that the local station is heard very faintly if at all. When this condition is reached, ro tating the first dial should have very little effect on the signal strength. This is all done with the 30-ohm rheostat turned off This finishes the operation of balancing the receiver, and the rheostat can be turned completely on again. In locating stations for the first time, it is easiest to turn the tickler knob to a point where putting a finger on the stator plates of the second condenser gives a click in the loud speaker, and ro tating the dial of this condenser should give a whistle when a station within range is transmitting. Turn back the tickler until the whistle disappears and adjust the aerial tuning condenser to the point where the station is loudest. Blueprints for this set, includ ing full-size drilling template and enlarged wiring diagram, may be obtained from the Radio depart ment, Popular Mechanics Maga zine, 200 E. Ontario st., Chicago. Include 15 cents to cover postage and packing. Specify blueprint No. 108 @ By filing the ground wire flat before sol dering it to a water pipe, and by soldering the antenna-wire tip into a copper lug, the contact surface of both will be enlarged and this has been found to increase the efficiency of some sets.

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832 POPULAR Cushioning Radio Tubes Microphonic rings are quite common in manv radio sets where the sockets are rigidly mounted on the subpanel. Every ota Sponge-Rubber Strip Prevents Microphonic Noises in Tubes jar in the room is readily transmitted to the tubes and distortion in tone. \ good remedvy for this trouble is a strip of sponge rubber, with the tube sockets mounted on it as shown in the photo. The fastened by means of screws projecting through both the base and the cushion. ~The screws are turned up quite tight so that the nuts and washers are pulled up below the underside of the cushion. Glue is then used to fasten the cushion to the baseboard. causes sockets are Adjustable Radio Socket Wrench lightening nuts on the various instru- ments of a radio set is sometimes rather difficult especially if attempted with a pair of pliers lo overcome this trouble sock et wrenches have been put on the mar ket One, which has been found espe ‘ally useful, is shown in the illustration designed to fit It has adjustable many different sizes of nuts. By pulling backward the jaws ( WawWs a thumb adjustment are tightened on the nut, whether this is of the hexagon or the knurled tvpe. The work is done entirely with the hand hold Wrench Closed Open and f END ViEW Showing Use ing the wrench. it can be \s it is nearly 10 in. long, used to reach nuts which are otherwise inaccessible. Magnetic Coupling of Parts Prevents Good Reception he intercoupling of the magnetic fields oft the various instruments in the radio receiver is one of the main causes of un stable operation, and distorting music or MECHANICS speech. and Faulty wiring, careless solderir defective instruments also for a fair share of the blame. Other forms of trouble are cated, but the invisible fields dificult to find. These fields are lil halos around the coils, condensers an other pieces. of apparatus, and must | diverted either by shielding the instri ments or by placing them at critical a1 gles, so that the fields will interact little as possible. This is often a har matter for the radio builder to do, so i1 strument designers have produced coils « the toroid, or “doughnut,” type and tl binocular form in which the field is cor fined‘to the coil. Shielded or “canned coils and condensers are availabl Grounded shields between the tubes ar other apparatus also tend to lessen tl troublesome intercoupling come easily are mot also Rheostat for Critical Filament Control \ rheostat of unusual design, for crit cal filament lately made it appearance on the market. The resistanc is varied by winding a wire from a short circuiting cylinder onto an insulating cvlinder, or vice versa. The cvlinders have a positive gear drive, and the wire is kept taut by means of ‘a torsion spring. It is claimed that the minimum resistance of the rheostat is less than .2-ohm. Twenty-four complete tur of the knob are necessary for varying t! resistance from minimum to maximu! giving a very fine micrometer adjustmet These rheostats are made in resistances 6, 15 and 30 ohms. control, has Hydrometer Only Reliable Tester of Storage Battery The best check on the condition storage battery is obtained with a hydr eter. A voltmeter does not give a t! reading of the condition of the battery a practically battery \ dead storage show a 6-volt pressure. A fully charg battery will give a hvdrometer (speci! gravity) reading of between 1.300 a1 1.285: the half-discharged battery rea ing 1.200, and a completely dead one 1.1! Never permit the battery reading to below 1.200.

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POPULAR MECHANICS imple Method of Rejuvenating Tubes - ubes that have lost their ability to give reception can be restored almost to former usefulness by the process of ivenation. This consists in applying : rnating current to the filament at : paratively high voltage for some “if nds, and finishing off with about 8 ‘a for about ten minutes. If the man . tured unit for this purpose is not lable, a homemade device can be . ed up that will accomplish the same - its. A bell-ringing transformer of the hy having taps for 6, 8 and 14 volts is s ured; this is connected to the 110-volt “ supply line, and the output taken to 1. filament posts of a tube socket. First . rmine if vour tubes are of the type r can be rejuvenated; if thev are oft UV-201A or C-301A types, it is safe roceed, but do not attempt to rejuve- other types. | Nace the tube in the socket and first . the full 14 volts for 30 seconds, it n keep the tube lighted with 8 volts it r ten minutes. These may seem to be Ice essive voltages, but the tubes will nd them if the transformer is not de- >» and alternating current is used as ected. It is possible that the tube will out under this treatment, but it v happens if proper care is taken. Rubber Bands Help Reduce Microphonic Tube Noises Owners of radio sets who are troubled h a tube which has become micro- nic and produces harsh ringing noises a n the set is jarred, can reduce the t| noises so me - - what by using — rubber bands as indicated in the sketch. Cut AVY RUBBER /® a long, wide BAND : and soft rub ber band apart, RIP OF and drape it RUBBER over the dome of the tube, al- lowing the ends to trail on the base of the A socket. Then ot retch a shorter band around the bulge { he tube so it will hold the first band a1 urely in position lhis arrangement 2 nds to reduce the vibrations imparted 10) the glass itself. and will be found a { Pp. especially with a tube that is doing od work otherwise. 833 Hidden Mat-Type Aerial Saves Space An efficient mat-type of aerial that takes up very little space is illustrated in the ac- Mat Type of Aerial, Showing How the Wires Are Laid; Inserts Show Various Ways of Using It companving drawing. [he upper-leit part shows the aerial partly rolled up, with a section cut away disclosing the wires. The metal strip along the lower edge forms a condenser, and the binding post for the connection to the set is shown in the center of this strip. An aerial of this tvpe can be used in many different wavs. [It may be suspended in the attic and connected to the aerial post of the set in the usual manner, or spread under the rug, either as an aerial or as a counter poise. It may also be used rolled up, in which position it is said to be verv selec tive, and as satisfactory as a loop aerial. It is available in 3 by 10-ft. and 3 by 6-ft. sizes. In localities where space is at a premium an aerial of this tvpe reradiation, and installations The fact that it can be hidden is of in terest to those who wish to keep as much apparatus minimizes Saves root sjoht as possible out Ot @A new upright B-battery, made specially for portable sets, is 3% in. long, 2% in. wide, and 55¢ in. high. It has 50 per cent more capacity than the common portable size and weighs only 2% pounds.

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834 Building “Binocular” Coils So-called binocular coils are easier t6 build than coils of the toroidal or dough- nut type, and are ideal for radio-frequency sets. These coils possess the same desir- Completed Binocular-Coil : Showing Mounting Screws in Position; tails of Wiring and Unit, and Right, Section Below, De- Construction able characteristics, electrically, as the toroidal The insert photo above shows the secondary of a homemade coil of this type. The construction is very simple; two bakelite tubes of 134-in. exter nal diameter are used for each coil, the walls being “oe in. thick and the length of each tube 3 in. They are wound with No. 22 d.s.c. wire as shown in the lower diagram. When used with .00025-mfd. condensers, 75 turns of wire are wound on each coil, making 150 turns for the pair. The wind- ing occupies 2% in. and there are 33 turns to the inch. Of the two coils one is wound clockwise and the other counterclockwise If .00035-mfd. condensers are used, the number of turns is reduced to 60 for each coil. The winding will occupy 1'%¢ in. on the tube. After the coils have been wound and the ends of the wire anchored by looping them through small holes, the tubes are as- sembled, as shown in the lower illustra- tion, by means of two small bakelite spacers, 4% in. thick, that can be sawed out with a small coping saw. When doing this the bakelite should be clamped to a thin board so that it will not chip. Two small flat-headed brass machine screws coils. POPULAR MECHANICS finish the assembly. The two coils then joined as shown in the plan. 7 completes the secondary of the unit The primary is then wound on a slig ly smaller tube having an outside diamet of 1% in. It is space-wound with 29 30 turns of No. 32 d.s.c. wire, and th slipped inside one of the pair of secor ary coils. Choose the one in which t brass connecting screw is countersu: so as to permit the smaller tube to inside freely. If desired this primary coil may moved in or out to obtain a tighter looser coupling, which is necessary to sure selectivity and prevent oscillatior Handle Phones with Care Headphones should be handled as c fully as a fine watch. When corre: built they are delicate instruments will not stand rough usage. One shou never let them drop on the table or flo: nor permit the cords to become twist: as the tinsel conductor in them is ea broken. See that the terminals are tig and do not leave phones where they exposed to dampness, or on a workbet where metal filings are scattered about Making the B-Battery Do Double Duty There are some tricks in the use of b teries with radio receivers which have decided bearing on operating costs. is now well known, a C-battery must used in all sets employing two stages a.{. amplification, that is, if the B-batte: current is to be conserved. When 4 volts are required for this C-battery, it not necessary to purchase a separate ut for this purpose. If the reader will ca: fully inspect the sketch attached, a si! ple method of securing the effect of a battery will be shown clearly. Most sets have a 22%-volt B-batter\ the circuit, as all do not use the heavy-duty batteries. At- tach the posi- tive C-lead from the set to the 22'%-volt post onthe battery and the negative C-lead from the set to the 18 volt post on the B-battery. It will read be seen that the 18%-volt post with t! arrangement really becomes a negat terminal.—L. H. Georger, Buffalo, N

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POPULAR MECHANICS 835

\ \ oy . . . Preventing Oscillation to Improve . . Radio Reception By F. L. BRITTIN | ‘OOD control is necessary in operating any type of radio receiver y A a.nd without this good results are impossible. Better control mean rer signals, and makes possible long-distance reception A set that touchy” and inclined to break into squeals is a set that is hard to uncontrollable oscillations ot this tvpe really mean that the set eased to be a receiver and has become a transmitter here is a very e rélationship between the receiver and transmitter. Some receivers ctually be used as transmitters of code signals by simply substitut telegraph key for the headphones or horn, and all that is neces . to cover surprising distances with such a transmitter is to increase < late voltage J at \ well-known type of simple receiver is shown in Fig. 1; note the y changes necessary to convert this receiver into an efficient tran ter, as shown in Fig. 2. This simply means that when your set is ed to squeal and howl you do not have equal chance tor good results with er man who operates his set with 4 ter skill. | he trouble may not lie alto- er with the operator, how- as the set may not be de- ned correctly. It mav need ter balancing, and this be done with neutral- ¢ condensers, potenti- ters, the addition oft ge or so OT fr.t. am ition, or by various * methods which add tly to the tone, se vitv and range ot the eilver. you do not care to e changes in your set prevent such a condi- tune the set careful as to reduce this inter ence to a minimum Chis be done by avoiding the posi-. your controls are in when your n

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836 POPULAR MECHANICS set is whistling or oscillating. It is easy suade your neighbor who has a simi to tell when the whistle is caused by your offender, to do the same, the quicker y own set, as then, leaving the regeneration will realize how good your set is on d control alone and rotating the tuning dial tance, if it has a chance to do its bs The unit can be bu up on a small panel ar AERIAL TRANSMITTING CHOKE- | iC or TUBE COIL yaseboard. 1e coils DETECTOR TUBE homemade and No. OOSMFD. ¥ d.c.c wire is used for The coil which is ¢ nected to the aerial ground is wound ar 2%-in. length of 3 tubing. Start ™% in. fr the end and wind turns, take off a tap continue the winding 50 more turns; this co + ] _— ~ri9l pletes the first coil A [efafafays 224,-V. B-BAT. a 4-in. length of 3 sien FF raswrier tubing, starting RECEIV . a Fenn 1e en vind Fic. | FiG.2 ft m- the end, wind double turns. To dot "1 The Close Relationship between Transmitters and Receivers, and the Few it is necessary to Changes Necessary to Turn One into the Other two lengths of wv winding them side will cause the whistle to rise and fall in side at the same time, making a doul pitch. If two stations are broadcasting on coil 60 turns in total length when co: similar wavelengths, they will often cause nected, 30 of which are in each of t the set to whistle; if the whistle does not two coils. Connect the end turn of o1 change pitch when the tuning dial is ro- ej] to the first turn of the other: at t! tated, but merely varies in volume, the point note that a lead is taken to the B trouble is not in your set. Keep the fila~ positive binding post. On this same tub ment supply to the tubes reduced to the from 1 to 134 in. out from the double c: lowest point consistent with clear signals wind the 10-turn coil to be connected and good volume. Turning up the tubes the receiver. Mount these coil units beyond this point will often cause the right angles and space them 2 or 3 set to break into oscillation, and also tends to shorten the life of the tubes. Most sets have a con- OO0010-MFD. _ SQ TURNS 15 ice trol marked either regeneration, 65 TURNS ‘MIDGET COND. ¢ EACH; = -l0 pre s > : er 4 “a AERIAL tickler, volume or _ sensitivity; No. 26 POST’ = when this control is turned too pr. ON SETY far over, the set breaks into oscil- lation and becomes a miniature transmitter sending out waves, occa and the length of these waves is he pes changed every time you change the position of the tuning dial. GROUND POST One of the best methods of ob- ON SET taining better results, and at the same time adding to the range Pe > : TAP and selectivity of the set is to IS th. TURN construct a non-radiating unit that can be attached to almost GROUNL any type of receiver. A good ex- ample of this type of apparatus is the unit shown in Fig. 3. It “pete © a Rin wl i A Simple Non-Radiating Unit That Can Be Added to Most R consists Of a Tew simple coils and ceivers, Improving Both Range and Selectivity condensers and an extra tube, and can be built for about $15. After you apart. Mount the 65-turn aerial coil in have learned that your set is a squealer, horizontal position with the 15-turn e1 the sooner you build the unit and per- toward the outside edge of the baseboat

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ndv to the aerial post. The other unit ounted in an upright position with the turn coil at the top. The tube socket be placed between the coils, and the stat and condensers are then mounted the front panel. Arrange the binding ts on either side of this panel in posi ns handiest to the points to be con- ted. - Fasten the coils to the baseboard small brass brackets. The small tralizing condenser can be mounted on the baseboard or the panel. en connecting this unit to the receiv et. bring additional A-negative and itive leads from the corresponding on the receiver. It is assumed that B-batterv of the receiver totals from » 90 volts. If the set uses a 22! B-battery only, add more units to total voltage up to from 45 to leaving the detector plate at 22 efore. If the receiver is of the tvpe ¢ two or more tubes, the 90-volt B tery is sufficient. Take the 90-volt B to the B-positive post on the unit. If re is a previous 90-volt connection on recelving set, leave it as it is, and take extra lead from this post to the B ve post on the unit. mnect the unit to the aerial and und and to the aerial and ground posts he receiver. Now the unit should be inced. Light the tubes in both the ind set, turning the tuning con- er of the unit to about 40. Increase feedback, or volume control of the eiving set, until it oscillates, and tune receiving set for a signal with its con ser. The signal will come in with the ual whistle; then turn the tuning con ser of the control unit for maximum ume. Vary the setting of the midget ndenser until, when turning the tun condenser of the control unit through e€ maximum volume of the signal, the histle is varied in volume but not in tch. Leave the midget condenser in position. Tuning is then done with the large condenser on the unit and e tuning controls on the receiver, add- g¢ selectivity and volume to the set. slueprints of the unit layout and wiring igram, may be obtained from the Radio partment, Popular Mechanics Maga ne, 200 E. Ontario st., Chicago. Inclose > cents to cover postage and packing. pecity blueprint 109 HOW TO PUT UP AN ATTIC \ERIAL is the title of an informative ticle in the July, 1923, number of the gazine. This will be sent to any ad- ress upon receipt of 25 cents. POPULAR MECHANICS 837 “Canned” Coils and Condensers Shielded or “canned” coils and con densers are now on the market, saving “Canned” Coil Reduces Pick-Up of Strong Local Sta- tions; Insert, Details of Shielded Condcnser } } ‘oS the experimenter the trouble of building his own By shielding the condenser, ef fects of hand capacity are practically eliminated, dust or other foreign particles cannot ac cumulate between the plates in terfering with the tuning of the set. and the condenser is protected against mag netic spraying from other instruments. “Canning” of the coils confines their fields and reduces the pick-up of strong local signals by the coils themselves, be sides allowing more compact construc tion, and eliminating the usual critical angle necessary with other r-f. coils. These advantages are especially important when r.f. amplification is emploved Compact Battery Eliminator \ compact A and B-elin available. ‘Taps are provided tor the va rious A and B-voltages and the unit is plugged into the 110-volt 60-cvele house-lighting circuit in the same manner linator 1s now as an electric iron, or any similar elec trical device The A-volt age taps are arranged so that tubes of the low or high filament voltage types can be used. When the instrument is connected to the set, the filament switch on the set is left turned on, and the entire installation is turned on and off with a push-pull switch on the front panel

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POPULAR | AS I Details of Underground Antenna Installation, Showing the Method of Coiling Wire and Spacing Coils Underground Antenna Improves Radio Reception A specially designed underground an- tenna is claimed to eliminate all interfer- ence by using ground waves instead of the air waves because the former are be- lieved to be practically free from atmos- pheric disturbances. The installation of the ground antenna is very simple. The method shown in the illustration was used by Popular Mechan- ics radio laboratory with good results and is specified by the manufacturer. The an- tenna consists of shielded and sheathed wire with especially constructed pick-up coils at the end and center, and is avail- able in either 75 or 100-ft. lengths. The pick-up transfer the energy or ‘ground waves by induction, and the sheathing transfers its pick-up of energy by capacity, the shielded lead-in acting as a return tor strays. Locate a suitable spot of ground under the window nearest the radio set, and dig a hole 3 ft. or more deep, 2% to 3 ft. in diameter. Start with the knob end of the antenna, winding in a clockwise direction to form a flat spiral coil. Working to- ward the center, keep the turns about 1 in. apart, until the space leit in the cen- ter is about 6 in. across, as shown in the upper diagram. Cover this coil with about 3 in. of dirt, carrying the wire in a long sweep through this dirt to the side of the bole again; then lay another coil and coils MECHANICS cover it in the same manner, continuir until four coils are made as shown. Th 75-ft. length will leave a balance to be use as a lead-in. Five or six coils can b wound with the 100-ft. antenna. If th: cellar floor is not cemented the install tion can be made in the basement. There are two other methods of instal ing this type of antenna, one, in a straight line trench from 18 in. to 2 ft. deep, ar another in a trench of the same depth, bu in the shape of the letter “S.” The metho illustrated is best, however, as the spir form is non-directional. New Dial Gives Readings in Wavelengths A new dial for locating stations | wavelength readings as well as the usu method is now available. The dial is ca brated both ways from zero, so that eith« right or left-hand condensers can be use This reading is shown through the wit dow at the upper edge of the dial; t! wavelength divisions are shown on tl chart at front, and an adjustable pointer which can be set to indicate the variou wavelengths, also turns withthe condenser shaft. An accurate wavelength readin; on the chart can be obtained if the con denser and coil used are of suitable types if not, the chart can be reversed, offering a blank surface for calibration for the condensers and coils used. If desired, th call letters of the stations can be inscrib¢ on the chart If the coil ar condenser spe ified by th maker are used a station tuned in wit the condense plates about halfway out the wavelengt! of the station | then looked uj; and the larg pointer is a justed with a setscrew to that waveleng' on the chart; the straight-line wavelengt condenser will then show the correspond ing wavelength on the chart. @A standard 50-ohm resistance coil, orig inally supplied with a bulb charger f charging L-batteries, when connected series with a neutrodyne receiver and 100-volt storage battery, has been foun by a reader to produce increased volume and purer tone.

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Cigar Humidor from Dime-Store Parts By J. EARLE MILLER \ | [GAR humidor, built, with the ex ‘ ception of the cedar lining and a small of brass, from parts purchased in a ent store, offers an attractive and made ornament for the amateur se tools and working space are limited. en the oak for the box was obtained. planed, from the dime store by pur- ing parts for the knockdown radio nets sold there, and resawing them to co ired dimensions. The actual size box was dictated more or less by size of the radio-cabinet parts, but in inside depth of 4% in., a length in. and a breadth inside of 4'é in., large enough to take 100 average- tting and assembling are simplified by ling the box as one solid unit, and sawing it apart to form the bottom d sections. The radio le parts were 34 in. thick. Both ends and the bottom of the front board are rab beted to a depth of % in., 34 in. wide, to take the ends and bottom, and the back at the ends and lower edge to form a joint for the bottom. The top can be rabbeted all around, and fitted in the sides, but, as the joint will show in any case, this is not necessary. The rabbeting was done by sawing the back line to the proper depth with a small coping saw, and the joint then was cut out with a chisel With the six sides completed, the parts were assembled with 5-in. round-head brass screws, and the corners, of brass, also from the ten-cent store, attached with similar screws, '4 in. long. After the as sembly is completed, mark a line around the box 1% in. below the top, and saw it apart on this line. If large-size brass con ners are used, with 1!

inet parts furnished two - FRONT ~ in. sides, it will be nece O14 MR

by 5%e6 in., for ront and b:ick, and two es, 94 by 6% in., for top bottom. All / CEDAR _ LINING DETAIL

sary to cut them down with snips and file to clear the cut mark, shaping the <<—+f[}+- SIDE OF JOINTS

Left, Painting the Design with Asphaltum Varnish; Const

Right, Etching the Plate; Center, Details of Humidor ruction R39

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840 sides to conform to the previous curves. The cedar lining may | I be obtained from old cigar T — boxes, or \%4-in. cedar boards can be bought from a lum- ber dealer. The latter make the best lining, << t

° o! | ° 4-2 ¥-4--- ----- =i / =

since few real cedar cigar boxes are avail able these days. Cut two pieces, 534 by 8% in., for the top and bottom of the lin- ing and drop them into place. It is not necessary to fasten either. The sides of the lower part of the box lining are cut 4 in. higher than the outer box, and fitted together with mitered corners, while the projecting ™% in. is beveled off, sloping from the inside edge down to the sides of the outer box. The sidepieces for the lid lining are cut 7@ in. wide, also fitted to- gether with mitered corners, and the lower edges are beveled with an inward slope, so that when the lid is closed, they will form a periect joint with the bevel of the lower part. This offset joint produces an efficient protection against rapid drying of the cigars. If the corner joints are properly fitted, it will not be necessary to nail the lining of the lower part of the box. The sides of the lid lining, however, should be fas- tened with small brads. The humidifier comes next. It is a copper box, % in.

POPULAR MECHANICS thick, fitting in one end the cabinet, and contai ing a sponge to hold sufficient supply water to keep t! p ro p er moistened for sor time. A row small holes drill across the face, j1 below the top ed permits gradu evaporation of 1 water, while cigars

Above, Fitting the Humidifier and the Design for Top; Right, the Completed Job; Left, Layout f the Humidifier sponge may be remoistened by dipping t copper box containing it in a basin water, and, after the sponge is filled, lowing the excess to run out of the hol The sponge container is cut from a sing sheet of copper, as shown in the det drawing, and is then bent and soldered t gether. The small %-in. flaps give it ditional rigidity and simplify soldering The next step is to finish the cabir For this, the corner pieces and most of t screws may be removed and laid hen stain the outside with black oil st. give it two coats of shellac, sanding ea one, and a coat of good varnish, follow1: which it is waxed. The screws left in du ing the finishing process, to hold the | together, may then be taken out cleaned, or discarded for new ones. The handles and latch, also from te cent store hardware counters, are add the corners and other screws restored, a! the humidor is complete, with the exc« tion of the cover ornament—a picador « his horse and a bull in action. It is c asi

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Construction POPULAR MECHANICS 841 m a sheet of 18-gauge sheet brass by hing away the surplus metal with a lution of one part nitric acid and two rts water. The design is so arranged it the picador’s lance and the tail of his rse, sweeping back between the bull’s rns, tie it together as one unit. he materials needed include a sheet of rauge brass, 5 by 6 in., a small can of haltum varnish, sold in most paint es, a fine-tipped brush, twenty cents’ rth of chemically pure nitric acid, and lass tray or dish, large enough to hold plate. One of the waterproof fiber s used by photographers will do, since paraffin coating will resist the acid. Clean one surface of the brass and, with heet of carbon paper, transfer the de- n to it. Next paint over that portion ich is to be preserved with the asphal- paint, as shown in the photograph, ng care to get the edges smooth, and h thin parts as the lance, tail and horns ut 46 in. wider than they will be in the shed piece. This extra width, which been added to the design, will offset sideward eating of the acid. This pre- ution is important. After the paint has lried, coat the entire back surface and edges of the brass, so that the acid can- t attack the metal from beneath, and the brass aside for twenty-four hours ntil the paint is perfectly dry. Mix the nitric acid with two parts of iter, being sure to pour the acid into the iter, and not the water into the acid, as the latter method is apt to result in plashing and painful burns, or damage to the clothes. Lay the brass sheet in the ray and cover it with the acid solution. Within a few seconds bubbles will begin to appear. Watch the solution carefully, nd if it starts to boil rapidly or give off hick greenish-brown fumes, add more iter carefully until the process has been wed down to slight bubbling. As the id eats into the brass, the metal dis- olved in it will gradually form greenish pper nitrate, turning later to blue as the mount of dissolved copper increases. he same acid can be used several times, wever, until it has reached a very deep ue. Eventually it will be “killed” by the ilution with metal salts, but a single mix- ire is sufficient to etch several such ites as the one needed. From time to time the work should be emoved from the bath and examined irefully to see that the paint is holding nd to gauge the progress of the etching. se a pair of pliers to pick up the brass. he acid will not harm them beyond de- ositing a coating of copper, which may be washed off with water. In case any of the acid is splashed on the skin or clothes, wash the affected part immediately in wa- ter, preferably with a little ammonia in it. If the acid is permitted to bubble too fast, the gas released, getting under the edges of the paint, will lift it free and per- mit the nitric solution to attack the de- sign. If that happens, wash off the work with water, dry it, and then repaint. Pro- ceeding slowlv, it may take four or five hours to eat away all the surplus metal, but slowness is better than too much haste, which either will spoil the work, or cause a 24-hour delay while a new coat of paint is drying. When the etching process is. completed, the paint is removed with turpentine and the edges of the work smoothed down with a small file. The surface is then polished with pumice stone and water, two holes drilled to take the screws, and the plate is ready to be mounted. The brass corners, handles and latch are like wise cleaned with pumice, and all the brass work lacquered to preserve the finish Leaky Roofs Although the roof had been reshingled lately, a small leak occurred. Being un- able to locate the leak myself and after two roof con- tractors had as- sured me that it was “fixed this Tar-Paper Trays Set under Drip Remedy Trouble of Leaky Roof time,’ the next rain proved the contrary. Climbing into the attic, I located the point where the water ran down a rafter and from there fell to the ceiling. I came to the conclusion that tar-paper drip pans placed directly beneath this rafter would remedy the trouble. I made them of diif- ferent lengths and widths and about 4 in. deep. By folding them over at the cor- ners and fastening these with a copper rivet, the trays are complete as the photo shows. It is not necessary to empty the trays even after a heavy rain, as only an inch or so of water will collect in a tray, and this soon evaporates, thus also keep- ing the attic less hot.—Frederick Boesser, Arlington, N. J.

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842 POPULAR MECHANICS Improvised Garden Tool Every farm has old pitchforks that have been discarded on account of broken handles. The ambitious farm lad can make them into useful garden tools. The sketch shows how a fork was con- verted into a garden culti- vator. Ahole, a trifle small- er than the shank on the tines, was drilled at an angle in the end of a 1'4- in. stick. The shank of the tines was forced into the hole in the handle. A drawknife vas used to take off the edges of the handle to hold. [It is very carrots and x the tool make useful for cultivating onions, other similar garden truck. easv to Patching a Slate Roof When a slate roof starts to leak be- cause some of the units have come out where nails have rusted away, the home owner usually makes a repair by using piece of galvanized or black sheet iron and shoving these up under the slates. This makes a bright spot on the roof, emphasizing the fact that a slate is miss- ing. The iron soon starts to rust and then disfigures the roof still more. Sheet lead on the other hand soon turns as . and being thicker than \\ ill be held more securely lates and will last for many black as the slate the iron pieces, by the upper vears. Ordinary thin wood shingles, cut to the proper size and colored the same tint as the slate make a much _ better repair than sheet iron. The inexperienced man who attempts to punch holes in at tached roof slate usually succeeds in cracking it and thus makes a bad matter worse. If a very sharp tempered steel tool is used to punch the nail holes by striking the head of the tool a sharp blow with a hammer, the slate will not crack anda clean-cut nail hole will be made. If a drill or soft-metal punch is used the slate will be cracked across or split into thin flakes. If care is taken to raise the edges of attached slates just enough t allow the entrance of a thin colored o: stained wood shingle, the patch will not be noticed at a casual glance, and the shingle will be held in place by the upper slates for years, although it is not nailed Substitute for Ferrotype Sheets Glossy prints may be made on the win dow panes in an emergency where th: regular ferrotvpe sheets and accessorie are not available. The glass is prepare by first daubing it with a solution ot paratin in benzine, and then briskly px ishing it with flannel. The wet prints ar stuck to the pane, the excess water rolled out with a pencil, and the print then left to dry. Prints made in this mar ner are remarkably free from the minut: cracks that are often present in those that have been ferrotyped on old or defective sheets.—W. Eidman, Cleveland, Ohio. Protecting Well Buckets Terra cotta or tile for tubing in drilled wells is becoming quite popular because x = ot its durability, but >> there is one dravy a ~ S back to its use that metallic bucl ets wear out ti rapidly due t Et ictio against t! waiis. A farmer elit inated tl wear by a plying a jack et of sma hardwo strips to t! bucket a shown in tl drawin Several stri are cut tl same leng al as the bucl et, and notched across the width about an inch from each end. They are place all around the bucket and bound tight! to it with two strands otf telephone wire The wire is below the surface of the woo and cannot come in contact with the tul ing, and the strips receive the wear i: stead of the bucket. They can readily b renewed whenever necessary.—L. Jordan, Vredenburgh, Ala.

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POPULAR MECHANICS ) Moving Target for Wing Shooting he drawing illustrates a novel moving vet with which the aspiring marksman practice shooting birds on the wing. 843 the illustration, and was made out of hard- wood. However, metal can be used, if desired, although it is harder to form for the amateur. Suspend it from the bottom of the strap iron, as shown, and paint it to imitate the bird. Take your stand in the clearing and have a companion place the rollers on the wire. Then, at a signal, iS SSS As JS Nga ¥ .3 ih a AN, re SS ‘eee el Method of Practice for Shooting } ra is on the Wing by Arranging Dummy Bird on an Inclined Trolley Line requires no springs or complicated chanism to effect the flight of the bird ~~ let him start "= (4 ee OG. /* Ire, va - > ‘ pa olley dow e ‘ t makes use of the force of gravity. The the aa ley her th it . ' , fe incline. The bird will rangement consists simply ot a taut ° : ° ° . ig . pres. 2 gain speed on its flight and will offer a re, a suitable running gear and a dum- : ; n “ie ad fine test for your skill in shooting on the bird cut out of wood or, better still, : . “ a wing. Arrange some bagging at the other metal. First choose the spot for your ‘ — . , te . tree to take up the shock when the bird rget practice, which should be an open age . ; eve hits it—L. B. Robbins, Harwich, Mass. ce of ground secluded from passers-by nd, if possible, with trees bordering it a — e ndre Fo an: Ss ~ , : ndred feet or more apart. Select two Magneto Holds Loose Bolts \ ees and stretch between them a length stout wire without kinks or splices. While making repairs and adjustments ne end should be as high as you can’ ona tractor, which requires the removal p ich and the other end about 3 ft. from of small bolts, there is danger of having K ground. The trolley is easily made by these mislaid and lost if they are merely ting a piece of wood to the shape indi- placed on some surface of the machine, ted, about 4 in. wide and 8 in. long on = and especially if the work has to be per- e top. Pivot a formed out in the ndow weight jf field, where a_ suit- i heel at each end, able box is not at £ r the top, with hand. The photo : rews so that the shows how the parts eels can turn free- may be placed on the Then, on the base of the magneto K ick side of the and held there by the u ard, screw a strip magnets. They can- | strap iron at right not easily be brushed gles to the edge off from here and e that it will pro- can be distributed so ct below the wood that their proper b out 1 ft. The bird places may be known n hould be large when replacing be nough to form a them.—George G. . ur-sized target. A ose is shown in Using Tractor —- ~* o Loose Bolts While aking Repairs McVicker, North Bend, Nebr.

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844 POPULAR Attaching Screen Tightly to Frames with Center Rails Fastening frames, screen to door and window so that it is without wrinkles and TACKING HERE PULLS WIRE TIGHT WIRE TACKED HERE SECOND WIRE TACKED HERE FIRST WIRE GOES OVER MIDDLE RAIL WITHOUT CUTTING Simple Method of Tacking Screen on Frames Tightly loose places, be done easily by the simple can method shown in the illustration. Cut a piece of screen about 6 in longer than the whole opening to be -covered. hen tack it at one end, stretch it as well possible by hand and tack at the other end. It will not be quite taut, but by tacking it down on both sides of the crosspiece, all sag will be taken out. The screen can now be tacked along the sides without difficulty, and the surplus at one end cut off with an old file sharpened to knife-edge. Hanger for Clothes Closet Saves Space Ir closets where space is novel clothes hanger shown tration will be found useful. limited, the in the illus- \ leneth of 1 by 3-in. stock 3 obtained and %- =) in. holes drilled, apart, halfway Ww 8 in. about MARBLE through the wood — ! at a /0" angle. The hole is con- tinued with a %- in. drill. keeping in line withthe left-hand slanting side of the ™%-in. hole. Then a slot is sawed in the board, slanting through the middle of the smaller hole and straight on the opposite side, as shown in the cross-sectional view. MECHANICS Marbles, which just fit in,the ™%-in. hole, are dropped in at the top. They cannot fall out through the 3¢-in. hole but stop near the bottom binding against and ho ing the clothing. Keeping Handles on Sharp-Edged Tools Handles often come off chisels, and other tools when using them. 17 following method will remedy the troub Mix 2 parts of wax, 2 parts of brick du and 8 parts of rosin, heat the mixture and apply it to the inner surfaces of tl tool handles, then immediately insert t! shank of the tool. If this is done quick! the shank will stick in the handle secure! fyouges Preserving Botanical Specimens Preservation of botanical specimet such as leaves and flowers, by pres them in books is rather unsatisfactory 1 they are apt to become damaged whe removed for examination or study. A be ter method is to remove the specin from the books after thev have be: pressed and dried, and place them tween photographers’ dry plates, f1 which tl {RUBBER BAND “7, emulsion been remo\y by washi: them in bath of stro lye soluti B yY snapptil a wide ru! 4 ber ban around plates, t! aot PHOTOGRAPHERS specimen PLATES | . be held in ] 1 SECTIONAL ne “aes ‘SPECIMENS VIEW sition tor ¢ amination tracing. A protecting frame is thus tained which allows rough handling, a: specimens can be piled upon one anot! without damage. Preheater for Ford Inlet Manifold A preheater for the inlet manifold Ford cars, which will prove satisfact: even on low-grade gas, can be made ply by wrapping some stranded cop; wire, of the kind used for radio aeri: around both inlet and exhaust manifol: to bind them into one unit. The copy conducts the heat from the exhaust to t inlet manifold and helps vaporize the f —G. E. McAllan, Millicent, Can.

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he Tool Chest Open, with Trays and ee Drawer Compartment Removed, Astonishing Number of Tools Fitted in Small Space Showing the An Apartment Tool Kit for Six Dollars \ HANDY fitted tool chest, providing a safe place not only for the tools led for radio building and home re- but the screws, brads, bolts and as well as other small parts, can be by the novice at home, and fitted at ll cost, largely from tools found in the cent stores. Fhe chest itself is made rom one of the small, light wood-and- el-covered boxes sold in trunk stores by many hardware dealers. It is t up of light wood, %e in. thick, cov- 1 on the outside with thin metal, enam- in sage-green, and bound with brass rners, with trunk-style latches and lock keep the contents secure. he. box used had inside dimensions of 16 in. and was 5% in. deep. It came ted with a full-length tray, with an in- e depth of 144 in. The tray was cut in sections, each 7 in. long, the cen- os “oe - 2 in. of its original 16-in. length being carded, and the open ends of the two tions were closed with strips of cigar- wood, 13% by 6 in. The cleats on ich the long tray had rested were re- ved, cut into 6%-in. lengths, and two them renailed along the sides of the x, at one end, low enough to allow the Oo new trays, when nested one above e other, to rest on the cleats and come el with the top of the chest. That left a space 2% in. deep, beneath the trays, for the longer tools in the bottom of the box. A 3-in. strip of 4%-in. wide brass was bent to form an angle bar, and screwed to the back of the chest at the end of the two trays, to keep them from sliding sidewavs. The two trays were divided into small compartments for radio parts, solder and flux, and spare electric-light plugs and fuses, with a long narrow space in the upper one for extra coping-saw blades, small files and pencils, and another space for small dividers and calipers. From the parts of several cigar boxes, a chest of three drawers, 6% by 7 in. by 414 in. deep, was built to fit in the opposite end of the chest. The inside depth of the drawer chest was 35% in., which was divid ed equally between the three drawers These are fitted without slides, working back and forth on each other. rhe drawer fronts project at each end ‘46 in., to fit flush with the outside of the box, and the top edge of the top drawer and bottom edge of the lower drawer have similar projections. Each drawer was di vided with partitions, cut from cigar boxes to form nine small compartments, 1% by 2 in. by 1 in. deep. The 27 com partments of the three drawers take care of a wide range of small nails and brads, screws, machine screws, taps, picture nails, 4

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$46 and tother articles. Cleats were nailed to the sides of the tool chest 134 in. above the bottom, to carrv the drawers. Between the drawers and trays, in the opposite end, there is a space 3 in. wide the full depth of the box. As pliers are among the most used tools, two pairs, one with long noses and the other of the side- cutting type, were fitted to the back and front. The long-nosed pair, purchased first, rests in a V-shaped wooden sheath, cut from cigar-box wood, while the other, attached more hastily, has a leather sheath made from part of a discarded glove. The lid fittings included others of the more often used Two strips of bakelite, } 2 in. long, 34 in. wide and &% in. thick, attached ™% in. apart, provide space for ten sizes of drills and a countersink. Two screwdrivers, a tools. reamer with detach- able handle, two sizes of flexible wrenches for radio nuts, a small steel hammer, a wood carvers’ knife, and a folding footrule com- plete the lid fittings. They are held in place by leather strips and clips made irom spare radio gridleak and resistor clips. The space be- POPULAR MECHANICS Drawer Compartment and One Tray Removed trom Chest, Showing How They Are Partitioned Chest Completely Fitted, with Block Plane and Cali- pers Lying on Drawer Top neath the drawers and trays was filled wit! an assortment of larger tools, includi: wood chisels from % to 1 in. in width small steel-framed coping saw and a larg: saw, taking either hacksa blades, a tack hamme two screwdrivers large: than those on the lid several files, small ti: snips, a small try-square and a machinists’ square several sizes of rout flat and triangular file packages of extra copi1 and hacksaw blades, assortment of ext drills, including all t] odd numbers from 1 59, inclusive, and a sma radio drill. A small blo plane and a vise made to cla on the edge of a table drop i to place between the trays a1 drawers, along with such odd and ends as spools of wire The cutting tools and block wood or ) i | -chis¢ plane and wo carvers’ knife—the special saw handles both wood and metal work, a1 the radio drill came from a hardware stor Everything else was picked up at the te: cent store hardware counters, which kept the total cost to a very low figure. T1 chest itself was bought at a sale for $1.75 and when completely fitted the entire cost was slightly over $6. whi Cleaning Suede Leather Ladies purses, shoes, bookbindings, a1 other articles made of or trimmed wit suede or leather, get “OOZE Casi and quickly soil and shabby -lookit The grime and cause the rou surface to beco1 black and_ shiny points. Ordin methods of cleani: are ineffective, b rubbing with a pie of fine will restore the o1 inal appearance the leather. This wu raise the nap. T! same method c be used for removi! shine from clothit —J. S. Hagans, C cago, Ill. sandpay }

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POPULAR MECHANICS Handy Quilt-Frame Props he present fad for old-fashioned patch- rk quilts is bringing the old quilting mes out of their dusty hiding places. ere seem to be a few sets in every town t go the rounds of church-society quilt- bees and do private service between es. In our society’ we have found t we must always count out four chairs th straight backs to hold up the frames, | this at such a height that those sew- on the quilt have to stand all the time. e of our number, whose husband is a penter, devised a set of props which de a hit with the whole society. They very substantial, hold the quilt at such height that those who work can be ited around the quilt with knees under and they not only allow four more irs to be used for seating purposes, : the props are much more convenient to get around the corners. Four strips of pine, 1% or 2 in. square and 25% in. long, are cut ex- actly alike, and the edges are dressed to avoid slivers. Four base supports for each standard are cut from a 4-in. board, according to the dimensions giv- en in the drawing. These supports add 2 in. to the height, making the total height 27% in. Four arms are cut 6 in. long from a 1- in. strip of pine and one arm is at- tached to each upright in a horizontal po- tion. The frames are easily held in place pon these arms by means of small C- ‘amps.—Mrs. Ruth Darling Shultis, Al- on, Mich. Chain Silences Rattling Keys lo avoid the rattling caused by a bunch keys striking against the metal edge the dashboard of an automobile, attach he ignition key to the ring with a 2%4-in. ngth of light chain, incased in rubber tubing. This will effectively remedy the ‘rouble. The chain should be long enough ') permit the keys to hang % to % in. ‘low the lower edge. This will also pre- nt the keys from wearing the paint off portion of the dash. 845 847 Improving Vacant Lots A home owner at Crete, Nebr., whothad a vacant lot adjoining his place in the edge of town, recently turned this into a beau- tiful nook simply by digging a winding lining it shallow pool, with ‘concrete Vacant Lot Improved by Artificial Pool with Rustic Bridge over It and gravel and building a pretty rustic bridge on it as shown in the photo. The concrete was laid an inch thick and was placed over the entire surface and the shore was lined with crushed rock. In some cases concrete might be dispensed with by lining the pool with pure clay, and surfacing this with gravel or sand. Clay is almost waterproof and can be spread over a large area. If running water is available, a small stream can be per- mitted to run into the pool continuously. The photo was taken in early spring be- fore vegetation had begun. The body of water is aboyt 8 or 10 in. deep. If the pool is lined with concrete, a drain should be provided so that the water can be changed frequently during hot weather.—Dale R. Van Horn, Walton, Nebr. Improvised Force Cup Most people know the usefulness of a plumbers’ force cup for cleaning out a clogged sink drain. When a regular force cup is not available, a good substitute can be made by cutting a hollow rubber ball in two, one part being cut slightly smaller than the other. Place the smaller part BROOM ____ into the larger HANDLE. one and fasten RUBBER BALL -----------" both to the end of an old broom handle with a screw, the rubber being protected with iron washers, as shown in the accompanying drawing.— James Noble, Toronto, Can.

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Exhaust Gases Cook Meais for Auto Tourists A fireless cooker novel kind was of a cleverly arranged by a western tourist who i an auto trip recently took his family for _— ad {3 ; \ Fes Heat from Ex- haust Pipe of Auto Cooks Meals for Tourists to the Pacific coast. The cooker—of the so-called pressure type—was attached to the running board, and connected by a tube to the engine exhaust. Thus, all he had to do was put the food in the cooker and the hot exhaust gases did the rest. Homemade Canteen The illustration shows the construction [ canteen and a carrier that anyone who can handle a soldering iron can make at home. It is cheap, vet will serve the purpose as well as an expensive one, and ot a the owner will have the satisfaction of knowing that he built it himself. Buy a couple of tin pie plates that have slightly rolled edges and are of the same size. Cut a small notch in the edge of each. Then place them together, notches meeting, and bind them in place with cord. Place in a vise and solder around sweat completely the circumference, making a water-tight Cut out the joint screwcap froma polish can and en- large the notches in the tins to corre- spond with its size and shape and solder this cap in the hole. Chis completes the canteen. Che holder can be made from a section of in- PIETINS SOLDERED TOGETHER wer tube. This should be shorter than the circumference of the canteen and should be split on the inside POPULAR MECHANICS as shown. piece for a carrying strap, then make third loop of rubber to hold the ends the slit tube fairly close together. Faste the strap and loop to the tube with tire cement or by vulcanizing. The cante: is simply pushed down into the holder ar the strap thrown over the shoulder in t! usual way.—L. B. Robbins, Massachusetts. Unpainted Tool Handles Preferable One frequently finds that handles tools and implements used around tl! house have been painted to improve the appearance. poor as a coat of paint blisters the hand when using the tool, | one, cause of the greater friction between skin and paint. The tool handles shoul therefore, be allowed t6 retain their na ural finish.—A. C. Cole, Chicago, Ill Novel Doorstop some friends I saw Instead of the usual « pet-covered brick of sand, the weight was an ordinary rubber filled with lead. This can be made in the fol- lowing way: Pro- cure several pounds of sheet When visiting novel doorstop. or a lead such as is used for wrapping tea; melt it to a ' = running heat, then | skim off the dross and pour the lead into the rubber. The hot lead will not injure the rubber, but as a prec the overshoe may be placed in a pan « taining cold water while pouring. Ajit the lead has cooled, the exposed port at the top is painted to match the rubb« When this stop is seen against a impression is that it is there by and one is inclined to push it pick it up. If he yields to this the visitor will have a surprise and t host a laugh.—J. E. Noble, Toronto, C door +] mista as de @li you want to enamel your car a! avoid streaks at the laps, add a little ket sene to the varnish; this will delay dryi long enough to enable you to make a go: joint with the first portion painted. Harwicl or varnis leather bag fu From a second tube cut a long This practice is, however, a + impulse

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POPULAR MECHANICS 849 Repairing Grounded Timer Screw lord timers sometimes give trouble by rounding one of the contact screws on e shell. This causes a continual spark in cvlinder and the motor will kick and kfire. The coil is also likely to over- If a new timer cannot be obtained, iove the wire and nut from the ground- screw and pull off the washer. This be cracked. If so, several thicknesses paper, with a small hole through the nter, can sometimes be used as a washer. tal cuttings often cause trouble by ring between the fiber ring and the | of the timer about the contact screw. is because of a shrunken fiber ring, can, in some cases, be cleaned out by rting gasoline about the screw. If fails to remove the cuttings, the fiber and the contact screw must be re- ved from the timer, and the cuttings ped out. Take care to replace the ring | screw with the same side in. A little llac run between the fiber ring and the er shell will keep out the cuttings for e time, and is worth trving if the timer therwise in good condition.—E. T. inderson, Humboldt, Towa. Tethering Cows ving and untying the tether rope is er troublesome and can be eliminated using the method shown in the illus- tion. The rope is tied to an old auto- bile casing, which is simply thrown er one of several posts driven into the und in the grazing field. Another ad- ntage of using this method is that the ising will roll around the post prevent- ¢ the rope from winding around the pole e of an Old Auto Cas- tor Tethering the Cow thus bringing the cow close to it and reasing her grazing area.—L. M. jor- n, Vredenburgh, Ala. Janitor’s Waste-Paper Barrel One of the daily duties of the janitor of an apartment building is the collection of waste paper and other refuse from the back porches. A om handy container » for this material 4 ra is a light barrel kf fitted with a strap-iron handle J? v as shown in the Waste-Paper Barrel for SS Janitor Saves Steps drawing. The handle is fastened on with bolts in the manner shown.» The hook is made large enough to go over the work- er’s shoulder. The barrel can be carried on the back or on the chest as conven- ience and necessity may require. Preventing Small Tractors from Overturning Small, light tractors are frequently used for pulling stalled trucks out of ditches, or similar heavy work. For this thev are quite éfficient, but on a heavy, dead pull, they are apt to turn backward, and injure or kill the driver, the tendency to turn over being due to the action of the worm gear in the differential. lo prevent such an accident, the tractor should be driven so as to face the truck to be pulled out, and should be hooked up in a reverse manner; that is, the chain should be fas tened to the front of the tractor. The tractor should then be thrown in reverse and the truck pulled out by backing the tractor away from it. @ According to a railroad paint chemist, one of the best formulas for making a paint for structural iron, such as bridges, is as follows: French yellow ocher in oil, 39 |lb.; lampblack in oil, 1 Ib.; raw lin- seed oil, 54 Ib., and japan drier, 6 Ib.

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850 POPULAR Removing Meat from Muskrat Skins ‘Trappers in the coast country near New Iberia, La., have found that a common clothes wringer is very handy for remov- Hunters Use Clothes Wringer to Remove Meat from Muskrat Pelts ing superfluous fat and meat from musk- rat hides, and hence this familiar laundry appliance is part of the standard equip- ment of every trapper in that region. When the marsh inhabitants have skinned the trapped muskrats they turn to the clothes wringer for the next operation in the preparation of the pelt for the market. Inserting the muskrat skin, which is wrong side out and covered with fat and meat, into the clothes wringer, the pelt is run between the rubber rollers to come out clean with all the meat off. Grease “burns” a pelt, and must be removed to get top prices for the furs. Secret Sliding-Door Latch A farmer who was troubled by peddlers opening the sliding doors of his barns and outbuildings, devised the latch shown in the drawing, with which he effectively foiled all inquisitive persons. A slot, about 3 in. long and 1 in. wide, was cut through the door about 3 ft. from the floor and 2 ft. from the jamb. Thus it resembled the fingerhole common on barn doors with which they are opened. A latch, about 2 ft. 6 in. long, was cut from a strip of oak, and the narrow end pivoted to the door on the inside by means of a MECHANICS large screw. A block was fastened to thy jamb for the latch to rest on, and a meta, guide was provided to keep the latch close to the door. Finally a wide cleat was screwed to the door, covering all but about 1 in. at the top of the fingerhole, but le: ing enough space under the latch to pe: mit the insertion of a finger to lift it. Renewing Window Shades When window shades become faded or worn out at the bottom, thev can be ma to wear again by cutting them off the r: tacking the bottom to the roll and he: ming the other end, which then becom: the bottom. This is an efficient meth of using curtains that would otherwi be discarded.—Charles Latour, Jr., Platt burg, N. Y. Drawer Pulls for Rustic Furniture One of the difficulties that meets the maker of rustic furniture is to provi drawer pulls that will harmonize with the style. The various pulls that can be pur- chased in a hardware store will not fill the bill. I have tried knots of rope and whittled wooden handles, but nothing suited me en- tirely until I hit upon the idea of using pine cones, preferably the small hard ones of the lodge- pole or jack pine. If kept dry, they will never open. They are attached to the drawer by means of a “4e6-in. screen-door hook from which th hook end has been cut off. The remai: ing shank is threaded and attached to t! drawer front by means of a small nut the inside, while the screweye is driven it to the pine cone. This forms a penda: pull of pleasing and harmonious effect Alfred Neuman, Troy, Mont. i 'ScrREeweve — ‘ \ PIN ‘EYEBOLT CONE Curved Printing Surface for Sharp Focus in Bromide Enlargements Practically all of my negatives are post-card size, and, in making bromi enlargements, I experienced difficulty getting a satisfactory focus on 6 by 10 or 8 by 12-in. prints. When the center the picture was in focus the outer p: tions were usually blurred, and vice vet

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h«¢ tai Sse as ut rial Furnishes Shelter and Food POPULAR MECHANICS 851 mpromising between the two gave un- tisfactory results. By providing a rved surface, on which the bromide pa- mounted, results were obtained are satisfactory except for architec- subtects. \ wooden box was made ong as the desired print and 1 in. wider. he height may be made as is convenient, a height of about 2 in. ts satisfactorv. partition was fitted into the box, divid- its length into two compartments. upper edges of the center partition 1 the ends of the box were cut in the pe of an arc, the curve being deter- ned by the distance from the lens to easel when the center of the picture is focus. The bromide paper is fitted to curves on the box. The device is fit- to the easel by means of two strips xed to the bottom of the box, and ex- nding beyond its ends. The curved sur- e may be covered with cardboard to e a better backing for the bromide pa- which is held in place by pins or small If only a small part of the negative to be enlarged, the flat surface is satis- ctory.—Victor Woodland, Denver. Edible Bird Houses Unusual in construction and design, rd houses of edible material have been iit by a Cincinnati woman in order to 1 urnish birds and squirrels with food dur- ng the winter months, and the animals terally eat themselves out of house and me. Che house proper consists of a 30- b. cake of round crackling, which is ierced with doors and windows of deco- itive design. Rooms are dug out afford- g¢ plenty of space. The roof and base- ard are heavily inlaid and coated with eed and broken grain, which is imbedded lard. Squares of pumpernickel and grains of corn add a decorative touch. rd House Made of Edible Mate- he dormers are filled with nuts.—L. R. ichenor, Cincinnati, Ohio. Safety Insurance for Shooting Gallery Following the accidental discharge of a rifle in the hands of a reckless patron, which resulted in the shattering of a large _— ———» } CHAIN CAN BE RELEASED ah } . BENEATH COUNTER ONLY | LJ a | a! I) NW Ww a) a i} {j | [" Chaining Guns to Counter in Shooting Gallery Insures Safety window and some damage to a building across the street, the proprietor ot a shooting gallery insured against a repeti tion by chaining the guns to the countet The chains used for this purpose were long enough to permit the guns to be used freely for target shooting but could not be turned toward other patrons without some difficulty. The chains are slipped through a hole in the counter and a short crosspiece is fastened to the end of the chain as shown. The chain can be re leased beneath the counter only, when it is necessary to remove the gun for cleaning or repairs.—G. E Hendrickson, Argyle, Wis. Cleaning Greasy Dishes Greasy dishes can be easily cleaned in the following way: A few pieces of gauze are sewed together to form a little sack, about 4 in. in length, which is filled with borax. The sack is closed on all sides and hot water is allowed to run on the bag for about a minute, while it is lying on a plate. By rubbing the plate with this bag, all traces of fat will disappear without soiling one’s hands. —Frank Kaye, Brooklyn, N. Y.

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CO or a) Wagon-Bed Derrick To avoid the strain of lifting a heavy wagon bed or hayrack by hand when he wishes to make a change from one to the POPULAR MECHANICS get out their correspondence en route. It is extremely difficult to execute neat type writing On a moving train with free-arm

movement, even in the central portio of the coach. As I am employed i: such capacity, I had to evolv a plan to expedite the work. am able to do typewriting quit: rapidly by resting the palm oi the hands, near the wrists, against the front edge of the typewriter frame surrounding the keyboard and using the swing of the finger: instead of that of the whole arm —Victor Labadie, Dallas, Tex. Retaining Wood Screws in Hardware It is often desired to keep the wood screws used for attaching small hardware and automobile dash instruments with them. A

Windlass on Side of Barn Is Used to Hoist Wagon Box other, an Indiana farmer has arranged a windlass on the side of his barn as shown in the photo. With this, it is easy to hoist the bed up under the barn roof where it hangs entirely out of the way and pro- tected from the weather until needed again.—J. M. Collins, Kansas City, Mo. Writing on a Moving Train Writing legibly on a fast-moving train is difficult to a person unaccustomed to it. The railroad conductor knows the trick of it and manages to get along quite satis- factorily. He prefers to write in a stand- ing position and holds his right elbow firmly against his side. The reason for this is that in a sitting posture there is too much lateral movement in the trunk of the body, while in a standing position this is more easily controlled. When the arm swings freely, as in ordinary writing, several joints of the body are affected in the process, each of which is capable of its own motion. Holding the elbow against one’s ribs “breaks” these motion tendencies, except that of the wrist, which movement is necessary in writing, and thus the pen is more easily controlled. The same principles modified apply in using a typewriter on a moving train. Many traveling men, news correspond- ents, and others, carry portable typewrit- ers and do much of their writing while traveling on trains, not to mention the various railroad and government men who travel in office cars and necessarily must ‘ good way to do this is to plac« the screws through tke holes in the hardware and wrap a fine wire about the threads. The ends of the wire are twisted together, which prevents the screws from falling out. Neat Ice-Box Inclosure Many small homes have no provision made for housing the ice box, with the re sult that the kitchen is cramped for room or the box has to be put into the dining room or on the back porch, which is in convenient an < unsatisfactory With this problen in mind, the own er of a small four room _ bungalow built the special inclosure shown in the photo. A corner formed b a jog.in the wal of the hous: formed two wall of the space The outside wa boarded in and an opening left i: front into whic! was fitted a lat The roof was given a good }

ticed door. pitch and covered with heavy tar paper About 2 ft. of space was left over the ic« box so that the lid could be lifted, and hole cut in the floor to permit the wast: water to run out, a length of rubber hos: being run through the hole and attache:

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POPULAR MECHANICS 853 the drain of the ice box. The lattice or was fitted with a spring latch and a llock, and had a window shade inside, ich could be drawn down in rainy ither to protect the finish on the box. Keeping Rabbits from Fruit Trees Coat the trunks of young apple and er fruit trees with the black, tarry int that is supplied by manufacturers roofing paper. It is applied with a rush. One liberal coating will last for irs and will protect trees from the wes of rabbits. At a Brushy Moun- orchard of 300 trees near Blacksbury, such treatment was given 211 trees years ago. Some of the other trees ‘re wrapped, or. coated with ordinary use paint. None of the properly painted ees have been molested, while the others ve been gnawed more or less yearly. rdled trees died and the growth of in- red trees was stunted.—Dr. H. D. Ribble. lacksbury, Va. Replacing Auto-Curtain Lights Sewing celluloid lights in auto curtains a rather difficult task, as anyone who tried it will admit. A good method, hich is comparatively easy, is shown in the drawing. A strip of felt is first dou- bled and sewed to the edge of the celluloid CELLULOID... 2} *~CELLULOID Juick and Easy Method of Sewing Celluloid Lights into the Auto Curtains na sewing machine and the felt can then ve hand-stitched to the edge of the cur- In as indicated in the lower detail.—G. \. Luers, Washington, D. C. A Simple Push Toy Novel toys are always of interest to children, and here is one that will appeal to them, especially as it is an easily made affair. Get two LID OF TIN CAN Interesting Homemade Whirling Toy, Which Will Appeal to the Youngsters old thread spools, a tin-can cover and a 3%-ft. length of No. 12 gauge galvanized iron wire. The method of making the toy is clearly shown in the illustration, and in use it is pushed along on the side walk, which will cause the tin-can cover to rotate at high speed, the cover being nailed to the top ot the upright spool. Making Tight Pipe Joints Lead filings sprinkled on the threads of pipe give a tighter joint than when ordi- nary white or red lead paste is used. The filings are made with a coarse rasp and are held in place by the cutting oil that re mains on the threads. This method was given a thorough test along with meth- ods commonly used, and it was found that, on '4-in. pipe, about half of the joints filled with lead paste leaked below a pres- sure of 8,500 lb. per square inch, one fail- ing at 1,050-Ib. pressure. A joint on which lead paste and lead filings were used leaked at 3,900-lb. pressure, while those on which only lead filings were used with- stood the full pressure of 8,500 pounds.

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\V JIRING a house is usu- ally considered the task of an expert electri- cian, but anyone who is able to grasp just a little theory and follow simple instruc- tions to the method of doing the work can easily wire his own home. The work of wiring a house is not advised, however, for home owners in the larger cities, where it is necessary that the work be done by a licensed electrician, but is especially recommended for the small-town home own- er, and for the _ farmer. These may make a worth- while saving by employing their spare time for this purpose. In this article the method of wiring houses under construction will be described, while sequent ar- as ticles will contain informa- tion on wiring old houses, flexible metal-conduit work, fixture hanging, etc. The first thing to do is to select the necessary tools. Those mostly employed by an electrician are a pair of wire cutters, a hammer and an au- ger. A pair of 6-in side-cutting pliers will be found most con- venient. A_ straight- claw hammer is high- ly preferable to an or- dinary carpenters’ hammer, as it is fre- quently necessary to remove porcelain knobs, boards, etc., for which the straight 854 Installation of Main ~~ to Meter Board NO.10.R.C.MAINS BRINGING POWER TO METER PORCELAIN KNOBS } ns a IE > WeTeR 7 ~ yc ae © ply Lines Running claw is particularly adapted The handle should be cut short to make it handy for nailing between studding joists and rafters, which ar usually spaced 16 in. center to center. A %-in. auger the most useful size on wiring job. Get two or thre: of these, as they soon get dull and no time should | wasted on the job with a du drill or in sharpening it. ratchet brace or a corne brace is absolutely necessar\ An ordinary brace cannot used owing to the cramped quarters in which one mu occasionally work. Next, get a couple of screwdrivers, on: having a 2 or 3-in. shank an the other a 5-in. shank. A soldering iron and a blow torch are also requisites { a wiring job, as every conne: tion must be soldered as precaution against fire ar other troubles. The need for a small can of non-acid so! dering flux, a pound or tw: of solid-wire solder, a roll « rubber tape and a roll friction tape is obviou A small keyhole saw necessary for sawin out holes for flus switch boxes, and wood chisel will great ly facilitate this For sawing boards small crosscut or pan¢ saw is used. Now the materia! for the work have to b: purchased. Perhap you can make arrange ments with the tow! worl

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Oe tk

x NO.10 R.C. COPPER WIRE | y .C. ( IA MAIN COPPER WIRE 7 2"°FLOOR BRANCH LINE aN \ PPLY. at ed 1ST FLOOR BRANCH LINE \ © x |= a [BASEMENT BRANCH LINE \* SINGLE BRANCH PLUG CUTOUTS

2-WIRE MAIN CUT-OUT SWITCH METER BOARD METER

} SCHEMATIC DIAGRAM OF MAINS, BRANCH @) LINES AND METER-BOARD WIRING {

j ‘\. BOARD TO SUPPORT aes TEE FIXTURE WIRING OVER CEILING JOISTS OF 28° FLOOR AND INSTALLATION OF CEILING OUTLET

STUDDING ---- PLASTER tATHN =

~ ~

SAWED OUT Nee A Sa %4 BOX : | > SWITCH _ XN BOX i

WIRING BETWEEN JOISTS, AND INSTALLATION OF SWITCH-BOX BOARD

DETAIL SHOWING SWITCH BOX INSTALLATION @) = ; wits y

Various Details of a Good Wiring Job Which Can Be Done by an Amateur, No Special Skill Being Required to Do This Work s

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856 POPULAR MECHANICS electric shop to return whatever wire, loom, knobs and tubes you may have left, as it is difficult to estimate the ex- act amount required. For an ordinary seven or eight-room ‘house you should have a 500-ft. roll of No. 14 rubber- covered copper wire; about 200 ft. of No. 12 rubber-covered wire; 100 ft. of No. 10 rubber-covered wire; 50 ft. of “circular loom”; 200 porcelain knobs; 13 DIRECT OUTLET = 20 2\%-in. porcelain tubes; as many flush-switch boxes as necessary; three double-pole, single-branch, plug _ cut- outs, and one two-wire main-panel cut- out with switch. The proper time to wire a new house is just before lathing. Then the parti- tions will all be up, or should be, the preliminary plumbing work will be fin- ished, the subfloors will be laid, and all the door and window jambs will be in place. The wiring has to be done at this time, and done as quickly as pos- sible, or the lathers will be waiting. Under ordinary circumstances and if nothing untoward happens to interrupt the work, it will take the amateur elec- trician about two or three days to wire a one-family house of average size. The “mains” are to be put in first. BRANCH LINES ~* LIGHT-F} 3WAY SWITCHES 3-WAY CIRCUIT FOR CONTROLLING ONE LIGHT FROM TWO SWITCHES Their position is determined by the lo- cation of the nearest power-line pole in the street or alley. The mains should be brought out of the side of the house, preferably a few feet below the roof and at a point which is nearest to the city power lines. Drill two holes, about 12 in. apart, near studs as shown in Fig. 1. Now tie a weight to the end of the No. 10 rubber-covered wire, taking the end on the inside of the coil. Always follow this practice in unwinding a coil, as it will prevent get- ting the wire tangled. Drop the wire down the inside of the wall until the weight hits the first-floor sill. Then drill a hole through the sill and pull the wire into the basement where the meter board is to be installed. Do the a same thing with the other main wire In some cases it is desired to have th: meter on the porch. A similar proce dure is then followed, taking care ne\ er to cross a joist, sill or studding, but to go through it, pushing a porcelai: tube or a length of loom through th: hole before threading the wir: through. A porcelain knob is nailed t the studding near the hole through the siding, and a length of loom, lon, enough to reach from the knob to about 4 in. outside of the wall, i slipped over the wire before it is pushed through the hole. Knobs should be located every 4 or 6 ft. apart, and the wire should be drawn taut before the LIGHT ma SWITCH —— 14@ LIGHT CIRCUIT ON SWITCH knobs are driven tight. A short lengt! of wire in the empty groove on th¢ knob, as shown in Fig. 2, will permit one to drive the nail down tight wit! out danger of breaking the knob. Grasp the wire with one hand and pull taut while driving the knob down as shown in Fig. 3. A good method oi straightening wire before knobbing i shown in the headpiece. After the two mains have bee: strung, two pairs of branch lines ar installed. No. 12 wire is used for thi purpose. These lines extend from th: meter board up through the partition and along the center of the ceilings 0! the first and second floors, from on: side of the house to the opposite side as shown diagrammatically in Fig. 4 & i" ELECTROLIER SWITCH at J LIGHT 16 ELECTROLIER CIRCUIT No switches are cut directly in the branch lines, but the wiring to the va rious rooms is tapped off at point most convenient. It will be found best practice to run the second-floor branc! line first. Usually the wires can be strung right over the joists of the ceil ing of the second floor, on knobs, in stead of passing through them, which saves considerable time and expense Wherever outlets are to be located a piece of 44-in. board should be naile: between the joists, as shown in Fig. /

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BRANCH LINE IN HOUSE. POPULAR MECHANICS 857 ipport the fixture. ooms. above the floor, as flush receptacles -ords, are located just e the baseboard. To sure that all switch -es are exactly the height, take a stick, t. long, set it up ver- and mark the joists, hown in Fig. 8. This ld be done before the d is nailed between Flush-switch boxes e kind shown in Fig. used. Where sever- vitches are necessary, sides of a number of e boxes are removed a larger box formed hown in Figs. 11 and The open end of the is put against the rd where the box is to cated and the outline traced on the board, lwav between the stud- s, taking care to have center of the box on 414-ft. mark that was viously made on the The ceiling out- re usually located in the center of Wall lights should be about switches about 4% rom the floor, and the wall outlets, INCORRECT METHOD CORRECT METHOD OF MAKING CONNECTIONS shown in Fig. 10. are used to fasten the box to the support- ing board, as shown in Fig. 9. tice will prevent lathers from dislodging the box, which is otherwise easily done. DRY CELLS " NO.12 WEATHERPROOF _ COPPER WIRE “\ Lathing nails and lath This prac- The coil of No. 14 wire is then untied and the circuits of the various rooms wired. Figs. 13, 14, 15 and 16 show the most common wiring diagrams. For hallwavs and large rooms, it is often de- sired to have two switches to control one light. The wiring is then done as shown in Fig. 15 and is called a “three-way” installation. Where it is desired to oper- ate two or three lights on a chandelier separately from a wall switch, the installation shown in Fig. 16, using a spe- 38 CIRCUIT The first CA cial electrolier switch, can be followed. time the button is pressed one group of lights is switched on, the second time the second group of lights is on, the third time all the lights are on, and the fourth time the circuit is broken and all the lights are out. These switches can be obtained to operate the : \ lights in different combinations. Wires 7 * should never be allowed to touch wood 3- WAY SWITCH ~~ 22 eS te - plaster or metal. At points where the Correct and Incorrect Method of Making Connections; wires must be loose or pass through sills, Method of Testing the Circuits, and the Wiring of a Farm-Yard Light ldings. ‘clamps on the boxes Drill holes at the corners and the keyhole saw to cut out the hole. are adjusted so t the boxes will project face of the board, as shown in Fig. 9, switch 4 in. 14 4 in. beyond studdings, boxes, a length of be used, fitting snugly between two knobs, s shown in Fig. 8, or from one knob to outside of an switch box, 7 and 9. ceiling - outlet supports, or loom should outlet support or as shown in the detail of Figs. Draw the ends of the wires to extend about 6 in. outside of an outlet and then twist the ends together to pre- vent them from being pushed back into partition. Wires between knobs should always be pulled tight. After the wiring of the second floor has been finished, proceed to string the branch wires for the first floor. In this ch makes the edge of the box flush the surface of the plaster. Before box is fastened, the necessary holes made for the wires by pushing out the perforated portions. Use the claw the hammer to knock the perforated tion inward and then bend it with a ewdriver until the piece breaks off as

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S08 POPULAR MECHANICS all the overhead wiring has to pass through them (ret a under- between 01st or masons chalkline and mark the ide ot the joists to tacilitate drilling oles through them in straight line for the brane] é hich should run par- illel to each other and about 6 in. apart. board and improvise a under the position where The scatfold is adjusted to suit the branch lines are to be strung. height of the the worker. The holes are drilled about in. from the lower edge of the joists and at an angle, as shown in Fig. 5, and porcelain tubes are pushed through from the holes. which will slipping out: the wire doing this, should alwavs be placed one end of the line. so that the wire can be pulled up vertically from ' _ the highest ends of prevent them from is then pulled through In the coll of wire on the floor it the coi The inside end of the coil is used t prevent tangling, as mentioned he f he ot} end of the wire is an- chored as shown in Fig. 6 Instead of baring the the connections and wire and making splices as vou go along, vou will find it much more conven- ient and quicker to allow the ends of the wires to hang loose at these points, and do the splicing and soldering after the wiring has been completed. Peel off all the rubber insulation from the ends and portions to be connected and then scrape the surtace of the copper clean with a knife to corrosion. Al- wavs support the wires with knobs near a splice, to take the strain off the wire, and neat twist, as shown in Fig. 17. This detail also shows the proper method of making connec- tions. Never twist the bare end to form a close coil around another wire, as shown in Fig. 18, as this will prevent the solder remove make a open coil or from flowing between the turns. The correct method of splicing the ends of two wires together, with a few open turns, is shown in Figs. 19 and 20. After the soldering iron is heated, taking care not to get it too hot, tin it properly and proceed to apply solder to every connec- tion. Apply flux to every connection first to make the solder \fiter solder- ing, apply the rubber tape and the fric- tion tape to insulate the soldered portions. The wiring of the basement can be done, on knobs, at anv time later, pro- vided the ceiling is not to be plastered. Otherwise the procedure already de scribed for the first floor is followed. To test the wiring to be sure that it is cor- rect, take two dry cells and connect them in series with a doorbell and to the branch stick wires, as shown in Fig. 21. Bring ends of both wires of every direct let together, which should cause the to ring if the wiring is correct. Ii bell does not ring, there is a break in 1 wiring at some connection, and this to be found at once. On outlets oper by a switch, the ends of the wire at switch have to be touching at the s time the wires of the lamp are toucl in order to close the circuit and ring bell. On circuits the end the wires in each switch box, and also three-way wires of the lamp outlet are connected the same way to make the bell ring. Aft the wiring has been found to be corré or made so, the preliminary work is cor pleted and the lathing and plastering be done. Wiring in barns is very easv to do it is. all open. On every farm equipp: with electricitv a vard light is neces The wiring to this light is done as sho in Fig. 22, so that it can be turned on off at both the house and the barn Making Small Propellers Propellers, used for a variety of m and experimental purposes, can be for from light sheet metal with the aid ot pair of tinsnips or ordinary shears strip of material of the desired width length is obtained and a circle is seri at each end as shown. The points wl these circles touch the long sides ot strip are connected by diagonal lines crossing point marking the center ot propeller. Two sn er circles are scril around this representing the cent ‘, PIECE and mounting h 0 \ ‘ Grin The diagonal line y are now curved sor Oo) ‘ there the (O) Secavesor What where they / \op/ | PROPELLER =the circles and ae edge of each b! . \ mav be cut out as { } dicated bv the de lines, which are ei 3 of a circle of a1 not too large in portion to the length of the blade. Fu ly the blades are given a slight twi opposite directions to make the prope revolve in the wind—J. S. Hagans, ‘ cago, Ill. @Small screws can be started easil difficult places by putting a piece of ¢ on the end of a match and sticking screw head to it.

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POPULAR Ridding Public Buildings of. Flies many schools, stores, churches, and r public buildings, flies become a great ince during the summer season. If uilding has a ventilating fan, it may ised to advantage to get rid ie flies. Drill a small hole e side of the fan casing, large igh to admit the nozzle of a rizing pump. Shut all win- and doors in the room. Qpen the top ventilators and ‘the bottom ones. Now start fan and fill pump with a good cticide. Operate the pump direct the vaporiz 1 liquid the hole. The fan will blow vapor all over the building fill the rooms. Don’t open doors or windows for about our. This plan has been tried essfully in the local high school.— lfred Sorenson, Humboldt, Iowa. \\ Using Rope as Tire n an emergency, when the autoist had pare tire with him and did not wish ruin the rim by running on it, improvised a tire from a rope, which he carried along. After the tire had been re @ moved, the pe was ound und the rim, as shown in the draw- so that it rojected bove the rim. Then a 1 ¢ ngth of ire was / — ° \ ROPE twisted around both rim and rope to prevent its coming off. The car was driven for a siderable distance in this way with- it any damage to the rim. Cleaning Zinc (here are many zinc articles used as kitchen fittings. To clean them, do not use the customary powders. A better iy, and one that takes much less effort, is use a cotton cloth dipped in kerosene. ib the zine well and then dry with a an cloth of the same material. This ‘thod has been found very effective. 7 MECHANICS 859 Seat Aids Gardener and Saves Space In order to have easy access to every row of plants a gardener made the seat shown in the photograph. It consists of a 12-in. plank with two heavy legs and eeeronyn - Handy Seat for the Gardener Permits Him to Get At the Plants Easily and to Set the Rows Closer Together slides, which are also made of 12-in. stock, to make it easier to shift the seat from row to row. Besides the ease of access gained, there is the additional advantage of being able to have the rows closer to- gether, as space for working is unneces- sary.—Frank Harazim, New York City. Improving Old-Style Gillette Razor If your old-style Gillette razor does not give satisfaction, do not discard it at once. A slight difference in the width of the blade causes it to lie very close to the safety guard, making it too rigid to cut the hair smoothly. Even new blades often seem to be dull. This condition is easily remedied by making the razor ad- justable. Place one or two thin paper or metal washers around the middle peg of the razor before putting in the blade, as indicated in the drawing. This gives the blade less curvature and consequently removes the cutting edges a little from the guard, and a greater portion of the blade is free to vibrate, thus insuring greater flexi- bility and therefore a keener cut. Of course, it reduces the safety somewhat, as the cut- ting edges are farther away from the guard, but, with care to ob- tain the proper ad- justment and if the razor is applied light- ly, this method will give good results and prove beneficial to the skin—Hatto Tap- penbeck, Hollywood, Calif. SHIN PAPER OR METAL WASHER

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S60 Quaint Old Well in Garden Is Both Attractive and Useful Imitation Well House Is Ornamental Storage Place for Leaf Mold Aside from being ornamental, an imita- tion well house will be found useful in a modern garden as a handy receptacle for the storage of leaf mold—so necessary to the successful growing of plants. The house is easily built by the amateur car- penter. Four rough 2 by 3-in. redwood posts are set into the ground in a square measuring 3 ft. across. This space is next inclosed with rough l-in. boards to the height of 2'2 ft., making a roomy bin for the storage of leaves and rich dirt. The four are connected at the top with rough 2 by 3- in. stock and a roof is added, which of six pieces of 2 bY 278. rough red- wood, cut long enough to make over- hanging eaves, each pair being joined in the center to form a ridge, 9 in. posts consists POPULAR MECHANICS Novel Method of Cooking with Use of an Acetylene-Gas Tank higher than the top of the framework shown. The roof is completed by naili; on 1 by ™%-in. slats, spaced 2 in. apart The bucket is a discarded paint buck: of oak and swings ona rope, which pas over a solid wooden wheel, nailed to “drop” from the ridge, and is tied to o of the posts. In summer, vines may trained to form a solid canopy over t roof and add to the attractiveness of 1 well house.—A. May California. Holaday, San Jo Eliminating Flat Spots in Painting It is often rather discouraging for amateur painter -o try to eliminate which wil cause trouble it alone, and it sometimes seems nearly possible. A good, simple method is apply a coat of linseed oil, brushing it well to allow as much absorption as po sible. Then allow a day or so to ela; before putting on another coat of paint over these spots.—L. H. Georger, Buffa New York. spots, Gas Stove for Campers and Tourists Campers and tourists who travel whe firewood or other fuel is not availa! can provide themselves with adequat: means for preparing meals by carrying tank of acetylene The tank mounted on the running board of the « and is provided with a 10-ft. length rubber hose, which can be extended reach the fire place of the improvi stove. When making camp, a shall trench is dug from the car a distance several feet and terminates in a hole so: what smaller than the dimensions of t plate which is used to cover it. The hi is laid in the trench and covered, leavit the open end projecting into the large: excavation wu! der the pla The gas turned o1 making a bla over which cooking n gas. be readi aone., As le as the plat covers the h completely, gas will not nite beneat and the rul hose will be damaged the heat.

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»' CAUSE the hacksaw is such a sim- ) ple tool, there is a feeling that “any- can use a hacksaw.” While this is rfectly true, there is a great difference een merely using a tool and getting utmost in service out of it, and even 1 such a simple tool as this, there is a ht and a wrong way of handling it. here are a few fundamental rules that imperative, if the proper service is be obtained from handsaw blades. having selected the proper blade, in it well in the frame. This is im- tant, to insure true cutting and to pre- breakage of blades. The saw is in- ed in the frame with the teeth point- away from the operator (this may foolish instruction, but I have seen m put in the other way), and the d edge” or flexible backsaw will be d to need greater tension in the e than a blade of the “all-hard” type. ir light and medium work, stand at vise and grasp the saw frame as shown

All Shop Notes published in 1925, in book form—Fifty Cents—from our Book Department Getting Service from the Hacksaw By JAMES TATE in Fig. 1, with the forefinger of the right hand pointing along the handle of the frame in the direction of the cut, and holding the end of the frame between the thumb and first two fingers of the left hand (Fig. 2). Start the cut easily, using the same stroke as in filing, and be sure to put on enough pressure to make the teeth bite and not slide over the metal, as allowing the saw to rub over the metal on the start of the cut glazes the teeth and starts the saw on the road to the junk box. After the first few strokes retighten the saw inthe frame. Lift the saw slight- ly on the return stroke so as to prevent the teeth from dragging or rubbing on the work, as any pressure on the return stroke also blunts the teeth. Keep the speed of the strokes to from 40 to 50 a minute, and the work will be cut more quickly and with less wear on the blade than if a faster stroke is used. Where a heavy pressure is required the end of the saw frame may be held as shown in Fig.

Fig .! 1 and 2, Proper Position amd Grasp of Saw for Light Work

rt 4 oomerer <a) bw— eaceet CORRECT Fic.3 _ 5 EFFECT OF CUTTING TUBING AND THIN SHEET METAL WITH COARSE BLADE INCORRECT

CORRECT

INCORRECT Fig.4 Figs. 3 and 4, Effect of Thin Metal and Tubing on Saw, and Holding Work in the Vise

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S62 > of the hand through the and pressure to the the hand all the weight transmitted hy part of thumb small each man owns own trame, and there is comparative- little handsawing done; what there 1s, being on different materials from time to time as in the course of assem blv or erection of machinery. In this case, i blade at being the fl ie base of the In his } most sShHops ] i\ necessary it naturally impossible for the men to change blades to suit the material to be cut, and a blade is selected that will work fairly well on all material to be handled; at least that is what should be done, although the men in the shop may be more or less at the mercy of the pur- chasing department. The blade is usually selected one with about 14 teeth to the inch, and this will work well on brass, cold-rolled steel, cast iron and tool steel. Even in the small shop, however, there is a decided advantage in supplving the men with a finer-tooth blade for work on thin sheet metal and tubing, one having 32 teeth to the inch being suitable for this purpose. It is an even greater advantage if the blades are kept in separate frames so that they can be picked up and used at once. Most hacksaw troubles come from try- ing to cut thin sheet metal or tubing with a blade that for the work. Fig. 3 shows what happens to the blade when a coarse-pitch saw is used for this work. For thin metal a blade should be selected having teeth so fine that two or too coarse is more ot them will engage the work at once. If the teeth “straddle” the metal, they will be stripped from the _ blade. Wherever possible sheet metal should be POPULAR MECHANICS held between two pieces of wood, a Fig. 6, when sawing it in the vise, the cut taken right through wood metal; this helps greatly in reduc breakage. If this is not possible, T Fig. 5, Grasp of for Heavy Pressure Fig. 6, Sawing 1 Metal between Bk Fig. 7, Cutting 17 Metal to Avoid Saw Tooth Breakage ee a. 8 CUTTING SHEET METAL Fic.7 care should be taken to saw through t metal at an angle, as shown at B, Fig If the metal is so thin that, with the bla at hand, even cutting at an angle allow only one tooth to bear on the at a time, then the sheet should be sav flat, as shown at A. The main thing observe is to have as many teeth as p sible cutting at once; never less tl two and preferably three. When cutting structural shapes the is a right and wrong way of holding th in the vise. Fig. + shows the correct incorrect methods for two coma shapes, and a little study will show | the correct method makes it easv for blade. The same principle applies other shapes. Recommendations of leading saw m ufacturers, who have made a study of art of cutting, are: For cast 1 solid babbitt, brass, copper, bronze, alut num, cold-rolled stock, soft steel, annea tool steel and heavy structural teeth to the inch; practice differs to si extent, one maker recommending 14 te: Saw Cc 1 steel

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solid cold-rolled machine steel, 18 th for tool steel, cast iron and brass; light structural steel, tool steel and rd metals, one recommends 18 teeth | another 24. Both unite in recom- nding 24 teeth for steel pipe, iron pipe, ss and copper pipe, and conduit, and thin sheet metals and tubing under --gauge, 32 teeth to the inch. Flexible- ck saws are not recommended for use tool steel, cast iron or brass by one iker, while another lists them for use these metals. However, their recom- endations are to be taken merely as a tide, or a basis on which to choose trial ides for any particular purpose, and hey are very useful in this respect. In ct, it will pay any hacksaw user to get he literature of the saw manufacturers n this subject, as it contains much prac- il information on the subject of hand d power sawing as well as charts for w selection. Serviceable Metal Paint Paddle A cheap case- knife, with the end ground off and a clip riveted to the blade near the handle as shown in the il- lustration, makes an ideal paint paddle for the home workman. Holes drilled through the blade make stirring quicker, and if a notch is cut in one side with a file, any small trace of white d or paint remaining under the rim of iriction-top can, can be easily scraped To facilitate cleaning, file down all rough edges before using. Cleaning Lantern Chimneys [n street work, where many oil lanterns re required for warning signals, the eaning of smoky chimneys. each day is time-consuming task. A very conven- ent and efficient method of cleaning a limney is to scoop in some dry sand until ie chimney is half full; then, stopping ith ends with the hands, shake it vigor- usly. The rock particles will scour off | the grime in a few moments. POPULAR MECHANICS 863 Forms for Concrete Culverts Forms for concrete end walls for small road culverts are easily made from a few sheets of corrugated-iron roofing. The —— -_e_—— a _—_——- —— —_—— —— ee —— —_ ~ —— — a pm, — Forms on Ends of Concrete Culverts Made of Corru- gated-Iron Roofing ends of the sheets are nailed to a 2-in. plank wide enough to give the desired thickness to the wall. A hole is cut for the tile and the form is ready to be poured. The corrugations help strengthen the form so that less bracing is required; at the same time the sheet iron permits bend- ing so as to make a semicircular wall if desired, a feature that would require con- siderable work if a wooden form were used. The form is light and easily handled, and the wavy surface adds to rather than detracts from the appearance of the fin- ished wall—M. W. Lowry, Athens, Ga. Safety Pawl on Truck Brakes While playing in a truck, which was parked on a hillside, two small children released the brake, allowing the truck to run down the hill with considerable speed and result- ing in a smash-up against a tree at the bottom. To prevent a similar accident, the driver put a safe- ty pawl on the brake as shown in the illustration. This makes it im- possible for a child to loosen the brake, as considerable force is necessary to pull it back to re- lease the pawl. The front lower portion of the brake lever is notched as indicated, and the pawl is pivoted in front of it on the ratchet quadrant—G. A. Luers, Washington, D. C. BRAKE \ . .

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S64 Convenient Rope Cutter One of the clerks in a San Francisco store has devised a very efficient cutter for rope. It consists ot a sharp blade ar- Metal Hook with Sharp Blade Cuts Rope Quickly ranged on one side of a metal hook. By this means the heavy rope can be easily and quickly cut off by pulling it forward against the sharp blade, as shown in the accompanying photograph. — Charles W. Geiger, San Francisco, Calif. Tool Setter for Lathe Work When cutting threads or turning ta- pers in the lathe, accurate work demands that the exact tip of the edge of the cut- ting tool be in the same horizontal plane as the lathe centers supporting the work. To get this setting quick- 3 ly and with Sy accuracy, the tool setter shown in the drawing was devised. It LOY consists of a rectangu- : lar strip of hard brass, to one end of which is at- tached a short angle strip. To the angle strip is sweated a length of brass tubing of sufficient size to admit a commercial level glass, with j clearance. about Me in. \n angle block is carefully plumbed and the tool setter is clamped to it, plumb in POPULAR MECHANICS both directions. with A level glass is smear: a little soft putty, put into the tu and adjusted until the bubble stands ce: tral. After the putty has set, the tube closed up with more putty and the de) is complete. In preliminary is skimmed off the work to insure its ing cylindrical and coaxial with the lat use, a centers. The tool setter is then pl between the work andthe tool. and latter adjusted. When the exact tip the tool is dead on the center of the wor the tool setter will stand plumb, with bubble in the center of the device can be used on evlindrical grir ers, thread millers, and like machines H. A. Freeman, Willimantic, Conn. level. Stopping the Shaft Quickly Shafting in long lines alwavs carrit many good-sized pulleys and the energ stored in these the shafts to for considerable periods after the power has been cut off; longer, of course, wh: the shaft turns on anti-friction bearing and is well lined up. When a belt brea or gets tan- gled up inan- 4 other and thrash- causes goes ing around, there is ur- gent need of stopping the shaft before great damage is done, and when the ac- cident in- volves a hu- man being, there is all the more need for quickly stop- ping. One factory has installed the type of sha brake shown in the photo. The couplin are of the type having smooth outer su faces and a band brake has been install on one near the motor driving the sl! It is an automobile brake with the bar altered to sit the coupling, mounted so that, normally, it is free tt the coupling. But when one pulls the handle of the rod, which is at a co! venient height for applving the weight of the body. the brake takes a ve! etfective hold. \fter shutting off t! power, one shaft usuallv ran 40 before it stopped, but with the brake, was stopped in 10 seconds. ha secure who secon

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POPULAR MECHANICS 865 Stamping High-Speed Drills Carpet Bumper Protects Door Jambs hanks of high-speed drills or end mills A western building-management firm often too hard to stamp after hard- recently offered a prize to any employe and if stamped before that proc- suggesting the lettering may be ground off, as the most eff- eh-speed mill or drill will bow toward cient means stamped side when hardened. We _ oi protecting the end mills, after they are hard- the highly | and ground on the shank, and give polished ma- shank a coat of etching varnish. hogany door en the varnish has dried right to be jambs while tched, we place a piece of thin white moving tur- on the shank and roll the stamp niture in or over the paper just the same out of the is is done when stamping soft work, rooms. The pt that the paper is touched lightly prize-winning the hardened shank. The letters device was figures on the stamp make the var- made of mn the shank stick to the paper, and heavy carpet, ng muriatic acid is then applied tothe 4 ft. long and e surfaces where it etches the mark. wide enough he paper sticks to the figures or let- to cover the on the shank, leave it alone, or apply jamb proper- ttle wet acid, which will loosen it. ly, as shown in the photo. Three strong ght stamping will act the same way, = spring-steel bands, heavily padded, served do not hit too hard. Place the pieces to attach the protector to the door jamb. ed in hot soda water to neutralize the and then wash off the varnish with zine. The shanks can then be oiled. Filling Holes in Brass —\V. L. Miles, Warren, R. I. Experimenters are often puzzled as to a how they are going to get rid ot holes in , brass castings, etc., which are drilled in An Eight-Row Garden Marker the wrong place or which become super- With-the aid of the marker shown inthe’ fluous as the result of some change or tograph the rows in large truck gar- improvement. The following method will can be marked accurately and quick- do the trick: Fill the holes with solder to lt consists of a long board with pointed within ‘%2 in. of the surface, then file a len pegs extending from the underside piece of brass of the same shade as the | a handle by which the device can be casting with a medium fine file, catching the filings on a piece of paper. Put the filings in a cup, pour killed muriatic acid over them and leave standing for a few minutes. Then sift them over the solder in the holes so that they can be seen to be a little higher than the surtace. Heat is then applied until the solder runs and adheres to the fil- ings. When cool, the surtace is sandpapered smooth and polished. This idea works well also on copper or iron castings but not on alumi- num. The acid is killed by drop- ping in some zinc stripped from old ¢ Homemade Garden Marker Which Marks Eight Rows dry cells. Both the acid and the ot Gs Gases Tome filings must be clean and free trom other kinds of filings and dust. The d. Bricks are tied on the marker to holes to be filled must be perfectly clean ght it down so that the pegs will make and tinned right to the top. eper impression. As eight rows can So larked at once, the task of marking a @Plaster of paris casts can be toughened xe garden is considerably shortened. by boiling in paratnn and polishing.

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866 F ? a SHEET-METAL PIECES ‘ } a | \AAy ; QO cs YA THREAD Ss } @ | | CLEANER >, yyy i —=—==_ | rT (| i | i} KF ’ l _— sail | S = | att i; / i IN D> t } N & Hil J Nic UY! SCREWED TO WALL PRESSED UPWARD ~ TO FIT NUT Scraping Out Threads of Secondhand Nuts Is a Quick and Easy Job with This Fixture Cleaning Out Old Nuts One of the hindrances to using second hand nuts is the thick scale or hard paint, lead, etc., which often accumulates in the threads. Using a hand scraper to remove this takes too much time to make it profit POPULAR MECHANICS A Tool Makers’ U-Iron For taking the place of the ordir angle plate, the U-iron illustrated will found a valuable addition to the t maker's equipment. A block of tool is used, which, after the machining op: tions are completed, is casehardened ground to the finished dimensions. block is milled out as shown, for the s of lightness, with a round-nosed end n Turn the work to mill the various surfa and do not upset the height of the t until you have gone all around the w Allow %e in. when taking the rough cuts for finishing. V-slots for hold either square or circular work are chined at right angles to each other the edge and top of the block, whi T-slot is milled into the opposite side bolting the device to the bed of a mach A third and smaller V-groove is cut right angles to the one on the front of the block, for holding work of section. Bolt holes for the clar are drilled and tapped in the stock at sides of the several grooves and slots strap clamps of the style illustrated be needed and are cut into ’ end and the middle, the better to « . form to the work being held and mini cross grooves able. However, anyone in charge of a_ the possibility of its slipping. small storeroom can — PaSe n make a handy fixture for —— ne ee cid this work that will do ' the job nicely in a mini- Tatetatearel mum of time. The ac- BHoLe, | } companying illustration = 4 shows the construction Pa ride Three pieces of sheet 2 — > metal are used to make OO0OO0OC | up the scraper lhe L piece nearest the wall is BOTTOM VIEW cut as indicated and bent WORK f , at right angles; the se pda an eau 1 | ° | , - ond is cut somewhat d @ F VO fee} - | ferently, with a V-projec “1 Flo] Cc tion on the top. The tl iis = " third piece is a plain one } : a = ( which holds the com- - ” r pleted device to the wall by means of four screws. . Cc The scraper here de- GLO scribed was dimensioned © E to clean out any size oft + , rs - si nut from 34 in. up. To | - eié ay 24 operate it, the projecting aoe. ve 3" —— wage parts are pressed togeth- - P . er + T+ 4 er until the “V” fits the $'ROUND-NOSE MOE) L. of | threads and the nut is END MILL ‘ o! 5 then turned to scrape DETAIL OF STRAPG, 2 REQUIRED out the dirt.—Harry ————.---- - - Moore, Montreal, Can. An All-Around Tool Which Takes the Place of the Usual Angle Plate

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POPULAR MECHANICS Crankcase Oil Keeps Mites Away ‘oultrymen find it necessary to use e means of destroying red mites espe- during the summer months. For- v coal tar mixed with kerosene was extensively, but the strong odor is objectionable in cities, although » is permissible on the farm. Worn crankease oil, applied liberally to all of the roosts and supports and also e nest boxes, has been found to be an tive substitute. Only three applica have kept the mites down an en season.—G. D. Willits, Adrian, Mich. Saving Gasoline nding that our gasoline bill was er high we started to investigate all ible causes of loss. \ number of were found to make a gallon of gaso- g g ist longer. Among other losses that » figured was the loss due to e\ apora- which was surprisingly large. We had two 50-gal. tanks, each of which had a small hole in the cover to ~VALVE STEM * KS let in air . A when the Zz gasoline Was A , drained out ARDBOARD BA a 7 : ASHERS FRA, ) On a warm x By 1 . GZ day one could . a ' easily smell the gas as it escaped ugh the holes. The condition could be bettered by making the holes ler as this hindered the flow of gaso- Che caps were removed and the air drilled large enough to receive the e stem of an old inner tube. Card- rd washers were placed on both sides e cap and the nut screwed down zhtly. No gas can now escape, as the e remains closed until gasoline is being ned out, when it is opened to let in Byberg, Silverton, Oreg. n Jonas f. Clipping Horses clipping the legs and undet es in the springtime, part of the animals will h more comtortable while working. which would incrusted in an unclipped easily be brushed trom the ved animal, while the top coat is suf- nt protection from chilly winds and rapid cooling after a working period. M. Baker, Wooster, Ohio. become long shedding hair ot ©, Can Small Platform Hung on Ladder Rungs Prevents Sore Feet or “Ladder Cramp” Platform on Ladder Prevents Cramp \ small platform or board, about 10 by 15 in. in dimensions, attached to a ladder as shown, by I means of two %-in. iron rods, hooked to go over a rung, will give quick relief to anv worker who is troubled with sore feet or “ladder cramp.” To pre vent splitting, strips should be nailed or screwed to the bottom, as shown. The rods should be about 26 in. long, threaded for at least 2 in., and each one should be provided with two nuts and two washer: Removing Paint Residue Paint often collects un- ¥* der the edge of |** friction -top cans having a residue RESIDUE. “ ss = rim. This can easily be removed with the scraper shown in the illustration. It is cut from a piece of sheet iron to the shape shown and a hole is punched through it to per- mit hanging it up. It should be made of fairly f 1 stock and then it can be used also to remove the covers.

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Street Intersections Marked with Old Auto Rims Filled with Concrete Old Auto Rims Serve as Crossing Markers In one small Texas town, every street intersection is marked with an old auto rim filled with concrete. Obviously their cost is small compared to that of specially made markers, and autoists will take care not to ride over them for fear of damag- ing their tires. Marking Location of Studding for Base Nailing The illustration shows methods of lo- cating the studding for base nailing, all ot which are good, though some are better than the others. Fig. 1 illustrates how the studs are located by sounding, that is, by tapping the a hammer in order to ascertain the exact location by sound. This is the method quite monly used. However, sounding for every stud is not necessary. When one stud has been located, the others can be found by —< 16 ~~ 16" »~< 16 — 1 | 1 wall lightly with com

Fic. | | _— aa x ae SA | FiG.2 4 PENCIL MARK, ‘SCRATCH-AWL MARK, ‘CHISEL MARK ON ROUGH FLOOR BEFORE PLASTERING OR NAIL Several Methods of Marking Location of Studs to Per- mit Easy Attachment of Baseboards measurement in the manner illustrated. Fig. 2 sl nother commonl ge. 2 shows another commonl used method. Here the location of each stud POPULAR MECHANICS is marked before the plastering is don The mark is placed directly in front « the center of the stud, on the rough floo: with a dark crayon or a heavy lead pen A scratch awl, too, will give good result or the marking can be done with a wo chisel. If the chisel is somewhat dull, t! marks will show up better. A lath nail, other small nail, can also be used for t! purpose, driving it about 2 in. from ea stud and leaving the head slightly project ing above the floor, so that it can be se and pulled easily—H. H. Siegele, E: poria, Kans. Homemade Pipe Vise Easily Made and Carried The pipe vise shown in the drawing ca: easily be carried from one job to anothe and can readily be made by anyone wit little labor and at small expense. 1 clamping bars are made from 1% by 34-in flat steel, 61% in. long. The jaw is filed to the ” shape shown, after lav- ar ing out to take the small- is est and largest pipe to be handled.

Cc a With the ea | stock size \ given above, the largest pipe that can be handled is the 1%-in. size. The two clamping

bars are held together bv 1 % yt by X%-in. bars \ \ | - and YW%-in. y we a : = x pins, the lat- YT | i ter being se- cured by \%-in. cotter pins. A piece l by %-in. flat steel is bent to fit over tl! clamping bars and is fastened to the b tom bar with a %-in. pin, which is held in position with cotters. The top the U-strap is tapped for a standard bolt of the proper length to take in range of pipe sizes. Two holes, 14 o1 in. in diameter, are drilled in the bott bar to enable one to fasten it to a post table, or it can be used in a common \ ~Frank N. Coakley, Buffalo, N. Y. ‘ (A good cutting compound for dri hardened steel is made by of copper, | og. : teaspoonful ; acid, 20 drops. mixing sulp! alum, % oz.; salt vinegar, 1 gill, and nit!

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POPULAR MECHANICS 869

Quieting Turbulent Water Cutting Seed Potatoes Wave disturbances, or other turbulent To cut seed potatoes rapidly, a box de- ter-surface conditions, which-accom- signed to allow the tubers to roll closely ny the high velocities existing in stream onto the operators hands is used as innels below overflow dams, llways, drops, ete. can be ken up and entirely elimi- ted, by the use of brush baf- Large branches of trees, or n whole trees in the case of larger streams, are cut and ed in the channels, where are held in place by steel les: run to suitable anchor- The smaller pulsations in . which cannot be damped by metrical baffles, because of regularity, are entirely inated by the irregular brush tructions. A Telephone That “Honks” telephone that honks can be d to advantage in shops ere noise prevents the ordi- ringing apparatus from be- heard. To make this change an ordinary telephone the following shown in the accompanying photograph. terials are required: A Ford cutout, a he potatoes are cut so that each piece it battery, a Ford horn of the battery contains one or more eyes. Thus each pe and pieces of wire. Disconnect the tuber must be handled and cut several res leading to the ringer magnets of the times. The sloping box allows the spuds ephone and connect them to the cut- to be examined and selected easily for as shown in the diagram. The spring rapid cutting ion of the cutout points should be —

Cutting Seed Potatoes Rapidly with the Aid of an Inclined Box Which Facilitates Handling Them

ened. When the circuit is closed at Tumble Weeds Burned in Wire Cages telephone exchange, the cutout is Ey Lon ed. which in turn closes the battery One irrigation district has found that rcuit to the horn and causes it to sound the tumble weeds and miscellaneous de- Mabel Ellis, Richland, Mo bris which collect in the canals at checks, -< - 6] , © ° turnouts, bridges, and other irrigation structures, and which must be removed

PHONE WITH BELLS almost daily in order to keep the canals — ae open, can best be disposed of by drying y7 CUT OUT and burning them in huge woven-wire cages. This prevents the weeds from causing further annoyance by being blown back into the ditches or on ad- jacent farm lands. The cages are placed along the canals at points where the de- bris collects, and the wet weeds deposited in the cages one day are allowed to dry until the next cleaning, then burned just before the new accumulations of wet ma- terial are removed from the canals.

: @ When using a reamer or tap that is too -6-V. BATTERY small, cut a narrow strip of tin and bend = *--GROUND it over one or more of the teeth to make stituting an Auto Horn for the Telephone Bell When them take a larger bite. J he same idea Loud Signals Are Desired will work on a pipe or bolt die.

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870 POPULAR Combined Micrometer and Work Holder Micrometer holders are handy for many kinds of measuring work, and the one shown in the illustration has an added => MicR SUME TER => } ASHERS } SCREW SLors } “2 WY Work Holder ‘ S for Microm- eter Doubles Its Usefulness feature that makes it doubly useful. It consists of a small table whereon the work can be laid. The body of the holder is made from a piece of “e¢-in. sheet metal, bent and cut to the shape indicated. large washers, a screw and wingnut, work- ing in a slot in the body, complete the device. The holder is made for use when batches of parts are to be tested. The micrometer is located in the holder in a that will bring the measuring faces in the center of the work, and the clamping fixture is moved up or down as required to fasten it. Thus, it is only necessary to lay the work on the table on which it is at once located centrally and squarely, making a true measurement cer- tain.—Harry Moore, Montreal, Can. Two position Homemade Elevator Wings Wings of a grain elevator loosen quite readily and many of them are lost entire- ly during a season’s run after the third vear unless they are overhauled every vear. We did not realize this fact until we removed the chain and wings and were surprised to find sixteen of the wings gone. We had but six new ones, so we took a piece of No. 16 gauge sheet metal— the heaviest on hand—and with a compass marked the circles, which were cut out with a in. cold chisel, using a piece of casting with a flat surface to cut on. On cutting through the sheet, the chisel MECHANICS turns down the edge so that, when t wing is completed, it is strengthened cor siderably by this upturned edge. A wa er was placed on the head of the riv and we found that these wings, althou; thinner than the old ones, were just good.—G. McVicker, North Bend, Neb: Marking Triangles for Identification Many draftsmen lose triangles sim; because they have no identification mar on them. A simple but effective method marking them is as follows: Obtain heavy writing pen with a new point, a: after dipping it in a solution of anhydro acetic acid, you will be able to write yor signature on the surface of the triang neatly. A little black ink can be add: to the solution if you wish the mark show very plainlv. The use of acid alo: gives the same effect as if the surface | been sand-blasted.—L. H. Georger, Bufi lo, New York. Cutting Circular Holes in Plate In boiler making and allied trades ci: cular holes of large diameters must oft: be cut in heavy plate. This is usually do by first scribing a circle of proper diameté and then chiseling by hand or cutting wit an acetylene torch. Where the latter method is not available the work of chis- eling can be made much easier by us- ing the tool shown in the illustration. It is a combina- SETSCREW tion ot a com- 7 ™ pass anda f a, Latdee # / . holder for the Lene io. that the latter can be guided in a circular path with pra cally no danger of striking the hand the hammer. The parts area center bl a length of %4-in. iron rod welded to side of this block and a movable tool hol slipped on the arm and held at any p by means of a small setscrew. In us small hole is drilled in the exact center the hole to be cut, and the screw in t center block is slipped through from underside and tightened, but not too mu since the center block should turn free chisel SO

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POPULAR MECHANICS Tapping Collets We had 50 large-sized collets with a in. threaded hole in the shank end. The le was hardened and ground and it was n discovered that the thread gauge uld not enter. They could not be nealed for fear of spoiling them, so eave them a coat of oil on the und surface and cleaned all the out of the threaded hole. The llets had a small part of a drift- hole break into the threaded e and I plugged this opening h wax. I then placed the col- on the bench, with the eaded hole up, and poured ng muriatic acid into each hole let it eat for about five min- I cleaned out each threaded 1 e with hot soda water, to neu- lize the acid, and then found the thread gauge fitted nice- Acid will not eat the wax. The p used for finish-sizing on these lets was just a couple of thou- dths, or small. We have ap- ied the same method on the railroad eat through a hard scale in order to ib'e to drill a hole that could not at started —W. L. Miles, Warren, ode Island. So, be Making Potato Hills Pay bushels of potatoes ‘re successfully harvested from a crate n, 8 ft. long, 6 ft. wide and 6 ft. high t of 4-in. boards, % in. thick, leaving in. space between the boards. To keep e dirt from sifting out, the bin was lined side with coarse straw and then filled th alternate lavers of manure and soil. e potatoes were planted 1 ft. apart each two eves to a hill, the top laver ping to the center to prevent water m running off. To make it possible to t the moisture in e soil, a piece of iber, about the e of a man’s arm, put into the center the bin, halfway wn, leaving 1 ft. otruding above dirt. The mois- re condition can determined by oving the timber | inserting the d This should done each week. Forty-two good Improvised Carpenters’ Plumb For an ordinary level as a plumb on walls, one carpenter got a 5-it. length of Plumb Made from a Length of Two- by-Four with Level Set in Slot 4-in. stock, smoothed it on four sides and cut a slot out of the center to accommodate the level. Small metal links, pivoted to the wood at both ends of the by slot, hold the level in place securely.— R. M. Singer, Chicago. Repairing an Air Compressor While repairing an air compressor, rated at about 75 lb., it was found that the pressure hose was unserviceable. As no other pressure hose was available, a piece of ordinary rubber tubing was tak en and rolled, for its entire length, in a piece of 2'%4-in. adhesive plaster, such as is sold at all drug stores; then it was bound again with a narrow strip of the same plaster, but laid on a | to prevent the lengthwise strip 1as from loosening As both ends of this improvised hose were clamped to connections, there was no possibility of its unraveling, and when completed, the hose withstood 100 Ib. of pressure EF, 41. I. Hunt, Pasa- Mipit- An 8-Ft. Bin from Which na, Calif. ere Harvested St. Boulanger, Alex- 42 Bu. of Good Potatoes andria, La. in One Season

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= » TT t4 a! — | \ oy | of the > h ec Fir | | | |c}B/a os 47! 4’ o | t i + $ fo } 4 “al | i = x t | i OV ° : | ‘ } . ea mr thik ir. Y =| ‘o | | i c t | ‘ rs 2 1 a |} © | on | oe > | x EF = =} \ = wu 7 oj: | | | ' | - ape SS | | | r— | +1) | : | wa ] ecgendt a4 | |}—t . i — oe Ses | T a" r| = aw | | Ort B 8) | w | 8. 5 os | | | | |i] aI = ~«~ St b 4 : At = : 4 | =e < Pe _ 25 ; + | + ~ A an ’ + 3 x t a a — — = scraps making four shelves for the left compart-

ment. Cut the longer shelves from 1 by 12-in. by ie Perspective of La y aterial . . ’ I : Ras 1 dry - Porch abine 14-{t. material. On the floor, 1 ft. 11% in. from iY aon nesiaanh: tos the plaster, draw a line 6 ft. 4 in. long, and square the Compartment e797

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POPULAR cloats in the left space, starting 1 ft. 24% in. 1 t € .pplied to Wall rotect 1 Kr nt edge and scribe to the the top of the floor shelf, and rang- he next four successively 1 ft. apart. fifth is 6 ft. 105@ in. above the floor. the middle space, the bottom shelf is from the floor and the next three are 1 8 in. bottom to bottom. The up- shelf lines with the other two. The st shelf in the broom closet is 4 ft. from the floor to the bottom; the is 125% in. above, leaving a 12-in. space to the bottom of the next shelf. Make cleats of 1 by 2-in. stock and nail up to the lines leveled on the wall. = a MECHANICS 873 below the tops of the shelves, making doorstops. The stiles and upper rails of the door are of 1% by 3-in. stock, sized to 2% in. in width, with exception of the lock stiles of the left doors of the two pairs, which are finished 3 in. wide, the 4% in. rabbet giving an outside width of 2% in. The lower rails are of 1% by 4-in. stock. Make the panels of %-in. three-ply fir on pine veneer, cutting them to the following sizes: Long door at left, upper panel, 8% in. by 2 ft. 4% in.; lower, 8% in. by 3 ft. 8% in.; short door above, 8% by 95@ in.; each of long pair, 11% in. Y«™. ea. > by 2 ft. 2% in.; Wainscoting ¢ Plaster ig i ~ 3 ) } 7 rn novo | END AROUND~s i XIZCLEATS;| | STILE ch a ‘CUT PANEL, | =i a DETAIL OF H SIDE PANEL IGE > q i an “ 4 #) m Water shed on It, Perspective ind Elevation yom Rack BROOM RACK | | r bats tand the ends and par- ns in place, plumb the keeping all front edges Mark the shelf posi- and square from the front edges, ing on cleats of 1 by 2-in. material, h have previously had the lower in- corner chamfered off. Do not glue, hrinkage of the boards will open their ts or check them. ul up the sides and partitions to their cleats, using six-penny finish nails en into the ends of the cleats, or eight- ny toenailed into studding where such conveniently spaced. The bottom | comes flush with the front of the net. ue and nail to the ends and partitions ne. es of 1% in. by 3-in. stock, sized to 2% width, and cut the upper rails and ng rails between. The lower edges of upper rail are 6 ft. 8% in. above the so that the upper edges are % in. n n SA TI \ bg 7) Foy ads End View of a Small Portable Laundry Cabinet for Porches Where There Is No Room for the Larger One, and = —+> : Detail of Leaf doors above, 11% by 9% in.: door of broom closet, upper panel, 1 ft. 354 in. by 2 ft. 4% in.; long panel, 1 ft. 35¢ in. by 3 ft. 8% in.; door above, 1 ft. 354 in. bv 954 inches. To make the broom and mop rack, cut a back cleat of 1 by 3-in. stock, chamfered on the edges, and to the center of the face nail the 2-in. strip with the grips for the brooms. The latter are made by boring l-in. holes with the centers spaced 8 in. apart, cutting a section 1 in. long from the stock in front and chiseling straight the stock behind, and chamfering the edges. : Because of the likelihood of water be- ing splashed about on the laundry porch, some form of wainscot to protect the plaster near the floor is rhis may consist simply of well enameled plas ter, or plaster covered with oilcloth, with a plain wooden band run around the walls 4 ft. from the or the plas desirable. OT Cap floor

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POPULAR M ter may be removed and 1-in. ceiling put in its place. he drawings illustrate a method of doing this. Take up the base- board and shoe, and pull the nails out from the back with pliers to avoid mar ring the front. Four feet from the level a line around the room and remove the plaster and lath Between the studs, with the edge of the pla a guide for their tops. nail 2 by 4-in. trim ming blocks. Cut 4-ft. leneths of V groove pine ceiling and nail up verticilly, floor. below it. ster as driving them closely together, and pind. nailing into the blocks and the bottom plates. Plumb often, for pieces cut from the end of a stock length are often wider at the freshly cut end than at the other due to shrinkage, and will tend to make the joints “run” at the top or bottom If desired, the edges mav be coated with white lead to hel Refit the baseboard and shoe, replacing lengths, or splicing on a stud by 4% bv 4-in. round-edge wainscot cap for the upper band, the corner joints, and every stud with eight-penny nails. If the ceiling is thicker or thinner than the plaster, rabbet the back of the cap to suit. To figure the amount | ing required, allow tive widths 22 inches. In laundry porches where a stationary cabinet is impossible, the little portable one illustrated has its uses. The top has p make them waterproof broken mitering Tse X& coping double-nailing at finish of 6 in. cel for every ECHANICS for the stiles and upper rails, and 1% | 4-in. stock for the lower rails. The pane are | ft. 8 in. in width and 2 ft. 2% in. los with the stiles projecting below the b tom rails 2'4 in., these being ripped to in. in width for this distance, to form I Using 3¢-in. three-plv panel veneer, panels 1 ft. 354 in. by 1 ft. 954 in. Rip 1 by 3-in. stock in the center to make dra er-slide cleats, and cut three for each to a length of 1 ft. 5'4 in. Glue and one at the top of each side, inside, the b ends i G1 in. from the edges of the pat and the front ends 2 in. from the f1 edges. The others are spaced 4% apart; and are notched around the st so as to bear against the panel venes hese must be square with the face ed of the panels. ongert The bottom cleats are | The three drawer rails ; of 11 3-in. by 1 ft. 10-in. stock, edges out, d eled to the stiles of the sides around the slide cleats The bottom shelf fitted at stiles and against the panel veneer. Ss are and notcl 1S ound front edge rising ™% in. above the lo front rail for a doorstop. Nail or secre it to its but do not glue, thou the front edge may be glued to its If a second shelf is desired, install it cleats in the same manner. For side guides, glue narrow strips of wv between the stiles against the panel venee to bring it flush with the stiles above t! cleats, dt i a drop leaf on each end, which, when’ drawer cleats. Cut narrow %-in. strij lifted, make a worktable, 1 ft. 834 in. wide of wood between cleats and shelves at t! by J ft. 7% in. long. back, for nailing for the edges of -> MATERIAL LIST Stationary Cabinet Portable Cabinet e, 1% 1 S45 pieces, 1% by 3 in. by 12 ft., pine S | nded sanded | 1 piece, 1% by I t S4s, ? pieces, 1% 1 14 » pir t 5 | sanded sanded | pieces, 1 by by 14 ft S4S, 1 piece, 14% by 4 ir y pine ¢ fir S | sanded sanded pieces, 1% by in. | 18 ft S45, 1 piece, 1 by 10 in. by 1 e or f S sanded sanded 1 piece, 1% by 4 in. 1 t S458, 1 piece, % in. by 2 by 8 » pine or f th: | n led panel veneer | eces, 1 by 12 in ‘ S4S, 1 piece, 1 by 5 in. by 4 ft., pine or fir, S | sanded. drawer front. | { es, 1 by 12 in. by 14 ft., 1 ‘ ft S4S, 1 piece, g by 5 in. by 12 ne fir » inded., drawer side | eces, 1 by 2 in. |! 14 I ‘ S48, 1 piece, %& by 6 in. by 14 ft ne f anded drawer bottor l ece, ¥% in. by 2 by ft., three-ply, pine or fir, 2 pair, 2% by 2 in. loose-pin butt | panel veneer 2 pair, 1 by 2%-in. hit 1 piece g in. by 2 by 4 ft., three-ply, pine or fir, 2 pair, 1 by 2-in. hinge * panel enet + 1%-in. glass knot | pair 2 by in. loose-pin butts. 1 elbow catch | 1%-in. glass drawer pulls (knobs) 1 I catch | forg catches bow catches. Cost of materials Cost of materials, about $8 Tis to 1 i, al about $28. Time to build, about 30 } ) hoa Glue up the top and shelves of 1 by 10 in. stock. Then build the two sides like panel doors, using 1% by 2'%-in. stock three ply back, which is cut 1 ft. 10 11 2 it. 134 in. It should be glued and na with four-penny finish nails. Attach

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POPULAR MECHANICS 875 with screws or nails from the under- of the cabinet glue “%e-in. strips te the of its cleats, giving a projection of 4% veneer, to support the brackets full length. Make the drawers with- sof ae * i SECTION A-A ; out lips, so that the fronts co 3

are flush with the cabinet when closed. Rabbet the 5<-in. sides into the 3%-in. front, and rabbet

b Re

i +

2

FRONT ELEVATION

over the ends front. he drop leaves 2 in. by 1 ft. in., cut from y 10-in. stock, nforced against rping by cleats 1 by 2-in. stock, mfered on the es and nailed crewed 2 in. m the ends. ke a tniangular cket, 8% by for each, and e to the un- ide as shown.

Perspective, Front Elevation and Section | through Small Port- | able Laundry- Porch Cabinet; Details of the Drop Leaf and Bracket, and End Ele- vation Are Shown on a Previous Page

the S-in. back into the sides

re the leaves to the top with 1% by = Slide the bottom into its grooves after the n. hinges, screwed on the underside. drawer is assembled. Build the doors of ere the brackets bear against the sides 1%-in. stock, making a rabbeted pair Guide Grooves for Hacksaw Blades keeping the line always on top, and the pieces will all be cut at the same angle Vhen using a power hacksaw for cut- An even better scheme is to first put the short pieces of stock from large round bar in a lathe and cut grooves in it about it often happens that the saw will 4 in. deep with a narrow cutting tool ut straight, with the result that the lhe groove should be about ‘4 in. wider es are cut too short, unless a large than that made by the saw blade. The unt has been left for finishing. This pieces are cut off with a hacksaw, the etimes is due to the fact that the saw = grooves acting as guides. Care should be le is not put on exactly square, which taken that the saw blade enters each es the set on one side of the teeth to groove freely. r off quicker than on the other side. rd spot in the material will have the @Abrasion marks can be removed from e effect. If a large number of short a print by rubbing it with a tuft of cotton, es are to be cut off, it isa good ideato dipped in alcohol and then rubbed over a rk the top of the bar with a chalkline, cake of bon ami.

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BOR YQ EMERY WHEEL RING-AND-PINION GEARS FROM AUTOMOBILE °) a 8 { & ° } i STEEL- PLATE ——_— HANDLE ——:' 18° t ~ MAIN SPINDLE ! CO i — Le. Side View and Plan of Mechanics’ Bench Grinder Made from Old Automobile Parts Grinder Made from Auto Parts Discarded automobile parts can often be used to advantage in making useful tools and devices for the workshop, as, ‘for in- stance, the hand-operated bench grinder shown in the drawings. It consists of wooden base upon which the frame is mounted, and mechanism comprising a POPULAR MECHANICS can be screwed on to hold the two parts place. The crank is made of \%-in. fl steel, cut and bent to the shape show and a handle, consisting of a carriage b: slipped through a wooden sleeve, is p1 vided on the end. A grinder made in this way is larger heavier than the usual type of be: grinders, and with it work can be acco: plished that is beyond the range of th: ordinary type. Making Soldering Fluxes The extensive use of solder for gene: work in the shop calls fora variety of fluxe suited to the metals that are to be unite As the mechanic works with such met as copper, steel, cast iron and aluminu: each one requires a different kind of flu in order that firm joints may be made The necessity for using fluxes in sold: ing lies in the fact that the oxide, always forms to a greater or less exte: upon all brightened metal surfaces, pr: vents the proper joining of the pieces. T| fluxes, by removing the oxide, allow solder to stick directly to the metal. lor soldering electric wires, commut tor risers and other copper-solderi: jobs, a flux should be used that. will n corrode the metal as a result of ele trolytic action. An excellent and eas used flux for this, as well as all othe copper soldering, is made by careful whi main spindle, the ring-and-pinion gears melting equal weights of vaseline taken from an old automobile, and an 8-_ rosin together The mixture is we in. emery wheel. stirred when melted, and poured int The frame is made from a piece of %4-in. convenient containers. This flux, whe steel plate, cut to the shape and dimen-- cold, has the consistency of butter, sions shown. It is _ Pek that a small part cut out flat accord- | Sap Oo a a — - of it will stick on t ing to the pattern, a tO TTS" joint. As rosin drilled at the points i © .| ‘ies in density, it m indicated and bent ; e ram be found advisab at right angles i... tie ~ 25 i to increase tl along t h e dotted “pate | yt BENT ON 27 amount use d. | lines. The legs are ies 5| DOTTED LINES creasing the ro securely bolted to ' will also result the base with ordi PATTERN FOR SHEET-METAL FRAME harder flux. nary machine bolts. : THREADED — A liquid flux he spindle is turned € & E=e AMUN UU i) copper electric wi' down and threaded ” fi ¢ quart ponnee is made by mixing for nuts at the points PLATE FOR ! GEAR AND CRANK parts of a satural shown and fitted FRING GEAR solution of with main bearing BRASS THRUST chloride with 4 pat and thrust rings nee alcohol and 2 p made of brass. The (— glycerin. The sat shaft for the ring | rated zinc-chlot gear and crank is an solution is obtai turned down and MAIN BEARING SECTIONAL view THROUGH by filling a bott threaded on both a. 2 aceeenee half full of hyd: ends, so that nuts Pattern of Frame and Details of Rings onli Dennings chloric acid and th

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POPULAR MECHANICS ng small strips and cuttings of sheet a few at a time, until the acid will ive no more. Mix the alcohol and erin together and add to the zinc so- n. The operation of dissolving the n the acid should be done in the open n account of the fumes that arise. 1 uniting wrought iron and steel, a | flux is made by dissolving zinc in itic acid to saturation as described e; then diluting the mixture with its amount of water and adding a lump of sal-ammoniac. The latter ts the solder to adhere, and in ad- n helps to prevent the soldering cop- from corroding. The chemical ac- of this flux depends upon the fact muriatic acid unites with iron and and in so doing deposits a film of on the materials to which the solder most readily adhere. In using any flux, all joints should be well washed dried to prevent corrosion. n excellent flux for steel parts, that not blacken or rust the work, is made 1 6.0z. of alcohol, 2 oz. of glycerin 1 oz. of zinc oxide. Cast iron is a dif- t metal to solder so as to make the ts hold, but this can be done easily by htening both surfaces and coating 1 with copper. The coppering solu- is made by dissolving a few crystals opper sulphate in a small bottle of er, and is applied with a brush. Cop sulphate, like practically all other llic salts, is poisonous when taken in- illy. Aluminum is a metal that offers ereatest difficulty in uniting it either luminum or to other metals. How- a solder prepared by melting to- er 84 parts tin, 16 parts aluminum and rts of copper in the following man- will be found quite satisfactory. the copper first, add the aluminum a e at a time, stirring constantly with ron rod; then add the tin and a small of tallow. Stand a grooved board up- stopping the ends with len plugs and pour hot metal into the ves to mold the er into sticks the *kness of lead the grooves neils. Use an inum soldering 1 The flux is posed of equal of tallow and after melting, half the quantity ine chloride. Protecting Qutdoor Electric Motors with Galvanized Sheet-Iron Covers 877 Fastening Plaster Board to Ceilings A Wisconsin contractor, who builds many homes wherein plaster board is used, found great difficulty in supporting DETAIL OF HINGE Handy Supports for Holding Sheets of Plaster Board against the Ceiling While Nailing Them without a helper the ceiling sheets for easy nailing until he devised the hinged l-supports shown in the illustration. Each support consists of a 4-ft. crosspiece and a 10-ft. standard. The latter is cut in two pieces joined with a stout spring, as shown. With these supports, one work man can raise a sheet of plaster board to the ceiling and wedge the board in place. Protecting the Outdoor Motor On a large country estate several elec- tric motors are used to run pumps for filling and emptying a swimming pool. New water is pumped into the pool di Che old water is pumped through underground tile rectly from a well. to irrigate a citrus orchard. The motors are mounted on con crete foundations the tops of which are rece sed to form a ledge, and galvanized sheet-iron covers are made to fit on this ledge as in licated in the photo. It is claimed that the motors are as W ell protected from the weather as if they were inside, although they are uncovered when used.

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POPULAR Brush for Garage Washroom A handy and efficient device for garages, machine shops and other shops where it is necessary to wash one’s hands frequently, « Holder Hands and rush in Garage Facilitates Cleaning Keeps Brush Clean a handbrush supported on a bracket \ pair of ordinary handbrushes are mounted on a strip of flat iron, which is bent to clamp loosely around the water pipe at the back of the sink, as shown. The bracket should be long enough to bring the brushes under the faucet, and a hand of heavy wire, drawn tight around the pipe below the iron, will support it at the desired height. In use, the brush is swung under the faucet so that the water flows directly it. In this position, the workman can scour his hands more quick- on lv and easilv than is possible when the iS } brush must be held in one hand, and the brush is alwavs clean.—G, E. Hendrick- Wis. son, Argvle, Using Stained Lumber At times during the small patches of stain may unavoidably seasoning process develop in lumber. This discoloration is usually caused by a mold and is not an indication of decay. Numerous tests have shown that stained lumber is entirely sat isfactory for painted or enameled wood vork. Lumber containing stains is al ways less expensive than bright stock, whether it is purchased in the grades ad mitting it, or in special “stained” grades. Money may be saved by using it in all painted work without lowering the qual itv of the finished product. ommended in many Its use is rec- houses. MECHANICS Drilling Rubber We use rubber in the shop for strippe on punch-press tools, but have always | trouble in drilling smooth or accu in it, until I hit on the follow method: If the rubber is to be a tight friction fit, use a “drill” the same dia: eter as the piece the rubber is to fit ove otherwise allow holes for clearance. The dr thin tubing, beveled sharp edge, all the bevel being inside. Ri the drill chuck at high speed with w as a lubricant. The hole will be smoot is a piece ot ti and slightly smaller at the bottom tl at the top. This method is only apy cable to through holes and cannot be u tor blind holes.—]John A. Blaker, We Auburn, Mass. Compressor for Split Sleeves In shops where considerable rey work is done, a tool for compressing sleeves, which are often used on rol bearings in axles, transmission and d: shaits, is almost a necessity. Such a can easily be made in a short time consists ofa piece of flat iron or steel, be to fit around the uncompres lhe ends are formed as indicated in illustration, one being drilled and tapp: sleeves Compressor for Split Sleeves Made from a Pie ; : : Flat Iron and a Screwhook for a screw, which is used to tighte device down on the sleeve to compre @ It is dangerous to wear jewelry on hands in a machine shop.

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Two Extra Bedroom Bungalow } KITCHEN. , 1 | BED ROOM SKA EEE OT RISIS } Room -| BATH irene fa) re BED ROOM I2-OxIF10 © Architects’ Smal! Hort se Service B Plan No. 5A59 ureau UESTIONS regarding home building addressed to this magazine will be answered by the Architects’ Small House Service Bureau of the United States, ts and indorsed by the department of commerce, tamped envelope for reply. United States government. i material lists for the bungalow shown above may be obtained at a nominal cost. Inc., controlled by the American Institute of Archi Blueprints, specifications Inclose self-addressed If further information is desired send five cents and stamped envelope for a 4-page booklet explaining how the small home bureau functions and showing twelve sample plans A EKATURE of the five-room colonial bungalow illustrated here, is the op- tunity to provide two extra bedrooms he second floor, if desired. Dormers be added to the front, thus furnishing ventilation for these bedrooms, for the storage space. e house is frame construction, exterior finish of siding and shingle concrete foundations and cement course. The triple-arch Palladian entrance to the porch is unusual in the first floor there is a living room, ng room, kitchen, dining alcove, two rooms, bath and porch. The number or of closets is surprising, yet there is no te of essential space. he house is designed to face south and can be reversed for the other ngs \ fireplace is a feature of the living m. An arched opening separates the ng room from the living quarters. Home Builders’ Questions We have a three-room house and are thinking of ng two more rooms and excavating underneath whole house. Will this be more expensive than ng down the whole building and making a new \. It will probably be expensive to make depends on The exact answer old hous« If it is in goo an addition tion of the rtainly be wise to save it Do not start the v t he ut an absolutely definite set plans and specif cations. Let the job to a good contractor. Q. How do you find out how thick masonry walls for houses should be? A. City ordinances generally fix the niting widths If you have 1 such ordinance, write he depart t cor erce, Washington, D. C., f thes amphlet er | Re nmended Minimutr }R ements for Sr Dwelling C« truction.” Send ] cents in coir this In any case l the rections of your architect Q. Please tell me why we have to rewax our floors so often. They are of oak. They were filled and a little yellow stain was used with the filler The wax seems to wear out very quickly though we use the best we can buy. A. This is unquestiona caused by the fact Q. We have a brick house. After every rain we have water stains underneath the window sills in our house. The paper comes off. I believe that there is any chance of this water coming in over the tops of the windows as these places have been examined and there do not does not seem to be any place for a How can we correct this dificulty? A. The water probably come in underneath the sills This is ised by their not heir re ly mhedded in 1 rtar 1 ¢ } ne other ices to form a water bat \ etent bri masot pr bably edy Q. The lower part of my house is finished in wide clap- boards, having mitered corners that have pulled apart in a few om. What can I do to remedy this fault? A. It should be possible to bring these boards up tight vith proper 1 A The joints st 1 then be filled

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POPULAR MECHANICS THE PROOF OF THE PUDDING This letter is to comment on your methods of pub lishing radio hookups They are described in a vet simple manner so that anyone can understand them A friend of mine and I built the 3-tube low-loss set de scribed in the Oct., 1925, issue It was a success with us; the first station we heard was KOA, at Denver It took us only three hours to build the set, and the following is a | of stations the f £ st we heard on re fit wor _ wae st te = KOA, WBAP, , K¥W, KMA WHT, WLIB, WDAF, WOJ, WJJD, WHO and WLS I think that is a fine start. We found out that the set tunes very sharp, and works well with either stor age-bhattery tubes or the 199 dry-cell type; however, we obtained more volume with the large tubes Her man itz and Will Schraman, Maplewood, Mo. I have finished the new 1926 model of the Super heterodyne described in the January, 1926, issue, and find a 1-meg. resistor in the first input clip of the amplifier unit is a decided improvement in my set. I now get Minneapolis at any time during the dav also got the London, England, station during the International trials, and another station which I was not able to place. The balance of the week receptior was poor for some reason and has been bad here fot some time now.—Andrew Robbie, Cavalier, N. Dak. * * * Some time ago you gave me a suggestion as to re versing the connections on my condensers as they dit fered slightly from the ones you specified in the Per fect-Tone set described in the Nov 1925, issue li you remember, I was troubled with body capacity. I wish to advise you that it completely eliminated the interference as soon as done. I wish to thank you very much for the suggestion and assure you that now the set works wonderfully It seems to use considerable B battery voltage, but I can remedy that with a B eliminator.—A. M. Augustine, Normal, II * * * The Popular Mechanics Superheterodyne Fight re ceiver has the best t } ian I heard in any radio and I have heard a Mine is the 1925 model, and the 1926 shou ye and reception tl have ever great many d be superior set, to mine except that I added 50 volts more B-battery and put in the new power tube which gave me about the same results as the changes which you made in the new model Although I have not sat up at night trying to see how many stations could get, I have, at the present time, recorded 88 and separated them just about as you state For instance, Atlanta, Ga., a station at Cincinnati and another one I do not recall, are a distance of only 7 meters apart, all three of them, yet I have sepa rated the three as well as getting a station at Boston, and one or two others which are on the same wave lengths I have no trouble cutting out Buffalo, which is a powerful station, and getting KDKA at Pittsburgh, which are only 10 meters apart I have received sta tions on wavelengths from 217 to 545 meters My opinion is that I have a receiver second to none re gardless of cost.—QO. A. Statler, Hotel Statler, Buf- falo, New York. A few months chanics &-tube oying pertect Chicago, III. our Poy ular Me- ers l am en é R. Grelland, No 25 you mailed me a blueprint No. 102 of the Perfect-Tone Six receiver | followed it to a “T,” so to speak, sent to Chicago for the ‘doughnut coils,” used «ll of the parts called for and also used the Acme low-loss variable condensers I did not stop for ce st, but used the best parts I could find shed the set the Sunday, put it aerial | it on and do not find neces sary to change anything as the set is entitled to the name ect spent last night getting onto the hang of « iting it: there was a slight whistle, but | find I r me this by turning down my detector Coste | id Know that it was lighted Local them and got 7:45 p.m also got Decatur, I] and New York City, all perfect. Pawtucket, R. I. ations we the World ‘re on and I plowed thro Battery Co., Chicago, ab Cleveland, O} Elmer | Hort I have built the two-tube set described in the M 1925, issue of Popular Mechanics Magazine, and much pleased with it The first station that rot w Denver, Colo., and I then logged 21 stations FI Hickok, Defiance, Ohio. [ am writing you again with reference to the ] Tube Loop set described in the August, 1925, issue have built the set and have had wonderful receptior local stations; in fact, everyone who has heard it that it is the best four-tube set they ever hea A. F. Hager, Buffalo, N. Y. * * * A short time ago I obtained a set of blueprints fr your radio department and built the 1926 model of y superheterodyne. I have had nothing but the best 1 sults from this new model, and I am very well satisfied with it. Perhaps the results I have been getting partly due to the superamplifier unit; at any rat cannot conceive of a clearer or easier to operate ceiver [I have built the complete machine in a gl case, % in. thick Being in the glass-cutting busi t was an easy matter to drill the holes The ca rather neat in appearance, and is somewhat of a n Eldon Simms, Detroit, Mich I built the three set described in the Septen number of Popular hanics Mag ne, and was cessful in getting Cuba on the k speaker very while local stations were on the : If anyone wa a good set at a low cost, I recommend that they | this set The Cuban station I had was PWX Vert Betle, Goose Lake, Iowa » 4* ur letter in regard to the trouble I had wit}! adio set received, and the instructions carried out soon as I put the 2-meg. resistor in the first input « f the amplifier unit the set worked perfectly I w to say that this not only cured the trouble in balar the set, but it also made the set more selective tl efor Besides, I received stations that I never heard oi fore, with much more volume on all stations, and tl was not due to good weather conditions, as the weat here has been terrible, with lots of static. I will again that by following your directions, I have the be radio set I have ever heard, regardless of price, when it comes to tone, there is none that can toucl Ind. * . K. H. Bolen, Anderson, From May, 1925, with an average temperatut ( rom 120 to 124° F., I heard very clearly on y 1925 Superheterodyne, almost better than I do now January) with the temperature at 105 have he Chicago, New York, San Antonio, Mexico City, B n City and 11 ot! , La Cieba, Sp. H Cincinnati, Z falo, Pittsburgh, 10 Pochlin Peter American stations duras »* # Here are the results of the B-T ription in the October Popular Mechanics: Beg ning at 7:45 p.m. Sunday evening, I tuned in 14 s tions on the loud speaker am using UV-199 tul and compared with my other set, this is excellent. | Sunday to Thursday inclusive, I tuned in 56 stat the farthest being San Antonio, Tex., 975 miles aw —Andrew Kostolnik, Jr., Louisville, Ky. * * * built from y set I have built y and the Super-Eight as described in March, 1925, issues of yout ga been working one week and I have had K already five nights, besides other Pacific-coast stat! ve had 116 stations to date Wesley Thomas, | Falls, N. J will be furnished free, [ Editor. ] by addressing Bureau of N accordance with the editorial policy of this magazine never to accept compensation in any fofm for what appears in our reading pages and also to avoid the appearance of doing so, we are obliged to omit the name of the maker or the seller of any article described. This information, however, is kept on file and Information, Popular Mechanics Magazine, Chicago