Popular Science Monthly 1918-05: Vol 92 Iss 5

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Popular Science Founded MONTH LY IS72 Diving through Enemy Balloon. NCTICE TO READER—When you finish reading this majfe this notiee, hand same to any postal employee and it will be pi gical Sate tee petra ae Tid ee

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Over a hundred years ago, the American Colonists knew the Seneca Indians to be the leading tribe of the Six Nations. Today, thousands of outdoor Americans who use Seneca Cameras, recognize in them the same qualities of leadership and superiority. As the old Indian philosopher Red Jacket would say “Surely there is something in the name.” We want you to convince yourself that Seneca stands for picture making satisfaction. Go to any Seneca Dealer, get a Catalog, select any Seneca Model that suits you, make pictures with it for 10 days—then if you would rather have your money than your Seneca, just ask for it. Results must sell the Seneca If you donot know the Seneca Dealer, write us for a catalog and his name. Seneca Camera Mfg. Company 159 State Street Rochester, N. Y. Seneca Chief A thin light weight coat pocket Seneca with new easy load- ing chamber, focus- ing lever—Spirit level on finder and many features that mean- picture taking satisfac- tion. Look it over. No. 1A takes 24x 44 picture

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Do You Want to Split Up the United States? The New Zone System of Postage for magazines will fence off the United States into sections as shown below a? O, of course you don’t. But you | \ are helping to do it right now by : not writing a letter of protest to your Congressman and your Senators about the Zone System for magazine postage recently passed by Congress. How quickly would the States be broken up into separate countries if we had to pay import taxes on all goods shipped between states? Well, it wouldn’t take very long. But Congress has passed a law by which it will cost more to get your maga- zines delivered the farther you live from where they are published. The farther west you live the more you will pay for magazines published in New York, Phila- delphia or Boston: Canada, at war for three and a half years, still sends two pounds of reading matter for one cent to the farthest points of the Dominion. Our Government pro- poses to charge ten cents a pound for carry- ing to the Western States the advertising portion of POPULAR SCIENCE MONTHLY and other publications—just twenty times Canada’s rate! We should be able to de- liver as cheaply as Canada can. When the new Zone System is finally in full force, the cost of magazines in the Middle and Far West will be so great that thousands of people will be obliged to give up their magazines and other period- icals. They no longer will keép up with the intellectual life of. the country. The West will no longer be united in the old compact way with the East. The new Zone Law has not yet been put into effect. You can help to get it repealed. Write your Congressman and your Senators and protest. If you do not know their names, ask POPULAR SCIENCE MONTHLY or your Postmaster, but what- ever you do protest.

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Popular Science Monthly Soaring High with Borrowed Wings This is not a nightmare but the presentation of a daring flight—imaginary, it is true, but completely within the limits of possibility. An earth-born Ford, is carried aloft by the wings of a powerful modern warplane, conveying men, arms and ammunition to the point where they are needed. The plane then returns for another Fordful of men

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Vol. 92 No. 5 Popular Science Monthly 225 West Thirty-ninth Street, New York City May, 1918 $1.50 Annually Using a Ford as an Airplane-Tender It could be done if the tender were designed to offer the least possible resistance to the air By Carl Dienstbach of the field guns, heavy blasts mark- ing the rhythm of the heavy artil- lery. The sharp staccato of the machine guns and the spiteful cracking of the rifles cannot be heard so far behind the battle line. Undisturbed by the distant din and turmoil the birds are singing, feed- ing and making love as if there were no such things as bloody war and de- struction. Suddeniy their singing, twittering and chirping cease. Their sharp ear has heard a strange sound to which it has not yet become accustomed as it has to the distant din of battle. It is a whirring sound, at first faint, yet sharp and per- sistent. As it approaches it becomes louder and more terrifying. The birds flutter around and seek shclter. A few moments later an airplane of a strange type appears above the treetops, makes a sharp curve and, with a graceful glide, comes to. rest upon the clearing which crowns the top of the hill. Itisa huge monster. Wings of great expanse and Pe afar comes the rolling thunder Covered driver's a tail in proportion “* rest upon a strange big _Windshveld lowered body, streamlined and ‘°"'"9 flight provided with wheels. Aluminum The pilot and his ma- chinist descend and from somewhere four other men, wearing sol- diers’ uniforms swarm out of the body of the big monster. There is some hurried activity and after a few minutes the big body is de- covered bonnet Diagram showing method of stream; lining a Ford for easy transportation 643 tached from the airplane, which then, greatly lightened, is ready for its return journey. The pilot and the machinist clamber to their respective places, a hearty ‘Good luck!” a wave of the hand, and, with a short run the machine rises from the ground and quickly disappears behind the treetops flying in the direction from which it had come a short time before. The body of the monster, relieved by the busy hands of the soldiers of its streamlining shell of canvas and alu- minum, proves to be a Ford, carrying two machine guns and a load of ammuni- tion and provisions, in addition to the gasoline required for a long trip. The shell is folded up and loaded on the car by three of the men, while the fourth is busy around the engine, putting it in shape for an immediate start. Five minutes later the Ford is mounted by the four soldiers and chug-chugs away in the direction of the battlefront. The scene pictured in the preceding lines is merely imag- inary, but it may become actual, if the Body with load covered with canvas /Shamtat of «= Suggestion of L. R. YXclothon light Carroll, of Roundup, tamng Montana, is adopted Motor and carried through by iiichiiedeti the government. The giant flyers of to- day have ample lifting power to carry a Ford together with its cargo. Aerial transportation does not balk at the weight to becarried, but at theindifferently

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644 shaped bulk of the load. A narrow motor- cycle may be lashed to an airplane, as it is,.but any ordinary automobile would kill the plane’s supporting power by the in- ordinate head-resistance it offers to the air. Racing automobiles have recently been designed with great care, so as to reduce the resistance they offer to the air, a policy. which, in racing, is as vital as in flying. A racing car may be lashed to an airplane as readily as a motorcycle. But a Ford car is not built on racer lines. The Ford would first have to be thoroughly streamlined and its wheels would have to be changed to disks by spoke-coverings. The problem still re- mains of providing an extra set of wheels for the airplane on which to restart and to reland after it has dropped its load. But that does not seem impossible of solu- tion, judging from the example of the large German seaplanes, which are transform- able into land-planes. These carry a set __of wheels that may be lowered at will. The plan may be carried out with a Ford even more easily than with the sea- plane, because the twin-engined planes have their landing wheels under each motor, and the Ford could be suspended between them. The wheels of the Ford could form a landing gear of its own, taking its weight in landing and Popular Science Monthly starting off the structure of the plane. The Ford would require no redesigning, Light framings with canvas or aluminum covering could transform its outline itito a perfect streamline, which would be ma- terially aided by a long empty tail. Doing the Washing for Forty Thousand Soldiers NE of the thousand and one problems which confront the military author- ities of a belligerent country is the neces- sity of providing ways and means for maintaining the cleanliness of the troops in camps or cantonments. The soldiers wear shirts, socks and underwear and use handkerchiefs and towels. All these articles become soiled by use and must be cleansed by washing from time to time to keep the men in good sanitary condi- tion. At Camp Upton, Yaphank, L. I, there are, at various times, from 25,000 to 40,000 men and to take care of their laundry ‘work is a tremendous task. The accompanying picture shows an interior view of the army laundry at Camp Upton and gives a good idea of the enormous size of the establishment. The machinery shown in the foreground is used for the ironing and pressing of the laundried garments. f. ot r ure SUM REE © Int. Film Serv. These pressing and ironing machines and many others are required to do work for the soldiers at Camp Upton, Yaphank, L. I. ‘The laundry work for 40,000 men is a colossal undertaking EWS

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Make Soldiers’ Waistcoats Out of Your Old Kid Gloves ATRIOTIC women in America may P profit by the experience of their Brit- ish cousins and follow their example, by devoting their attention to the making of “glove waistcoats” instead of the sweaters which their nimble fingers have been knit- _ ting heretofore for Popular Science Monthly 645 - Emmanuel, Giuseppe Garibaldi and Count Cavour and are the work of Jacopo Fran- chini, a skillful glassworker in Murano, near Venice, Italy, who lived in the early part of the nineteenth century and worked so hard at his strange craft that he died in a madhouse. The National Museum in Washington has recently acquired a fine collection of marvelous glass- the soldiers and sailors of our coun- try. These vests are made of waste material,discarded kid gloves, which cost practically nothing. The lin- ing costs only thirty-five cents. One of these vests can easily be made in a day or two, while the knitting of a sweater takes considerably more time. Another advantage of the glove vests is that they weigh but a few ounces, are work made by Franchini and placed it on ex- hibition. The portraits are of glass and really represent 4 cross section of a mosaic rod of glass. Franchini’s method of making these miniature portraits was highly ingenious. He began by mak- ing a mosaic of the three portraits, each in its indi- vidual frame and the whole set in a common circular less bulky than woolen sweaters, yet fully as warm and more windproof. In addition to that they do not shelter vermin as do the knitted garments. It is to be hoped that American women will see the advantages in this new patriotic work. The Smallest Portraits in the World HAT is believed to be the smallest group of portraits in the world, is exhibited in the National Mu- seum in Washing- ton. The portraits are arranged in the form of a cloverleaf and are enclosed in a circular frame about one-eighth of an inch in diameter. They represent King Victor Small object between finger and thumb and how it appears enlarged pages ee ee frame. The mo- 1s lgnt, warm, windproor waistcoat 1S saic was formed of ld kid gl at small cost S ‘ Se See SES: ae eee * sticks of solid glass of the desired color. After the mosaic was completed, the cylindrical composite rod was welded by heat and then drawn out. As the rod was drawn out it dimin- ished in diameter and the diameter of the individual sticks of colored glass of which it was composed dimin- ished in proportion. As the drawing out was done carefully, the particles of the sticks forming the mosaic remained in their relative positions, slight distortion could not be avoided, as may be noticed in our reproduction of the portraits greatly mag- nified. | Nevertheless, the results obtained were extraordinary. or nearly so. A .

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If you cant be a soldier - bea- , saver Buy U.5.War Savings Stamps : ‘On Sale Here @© Int. Film see How could anyone resist the mute appeal of these canine helpers in a good cause? Dogs as Patriotic Helpers in a Good: Cause URING “Thrift Week” in Los Ange- les these two dogs, Spike and Pride, took an active part in the campaign for. selling thrift stamps. To say that they were successful only mildly expresses the result of their joint efforts. Spike and Pride made a mute but effective ap- Popular Science Monthly No More Rubber Tires in Germany —Except for the Kaiser ‘ERMANY had a little rubber in the early days of the war, but she soon became reduced to smuggling in what she could through the mails. Great Britain soon closed this channel, also the traffic in automobile tires which were being im- ported through Sweden. Now, only the Kaiser rides in an automobile boasting real rubber tires. Everyone else has to bump along on tires filled with cork, paper or even rags. Locating Splinters Made Easy By This Device O one of the New York hospitals, lo- cated in a district where the manu- facture of clothing is cgnducted on a large scale, so many workers came every day -with splinters, parts of needles, and for- eign bodies in their fingers, that it became necessary to provide some simple method of locating foreign bodies without resort- ing to X-Rays. . The contrivance shown in the picture was the outcome of some experimenting by the house physicians, It has proved to be of great assistance in numerous instances since its adoption. A piece of black woolen cloth, eight inches square, was fastened to a square of adhesive plaster of the same size. In the center an oval opening was made, measur- ing five-eighths by one-half inch. By placing this over an electric light sup- peal to the patriot- (4% ism of the crowds. : Pride carried a bas- ket filled-with thrift stamps, while Spike, carrying a tin box with the inscription “I’m the Cashier,’’ was soon loaded down with the weight of the coins dropped into his cashbox. The two dogs to- gether disposed of hundreds of stamps ke every day and thus Z plied with a re w flector and placing the finger of the patient over the hole, excellent transillumination could be obtained, and any foreign body in the finger easily located. This little appara- tus has resulted in a saving, both in time and money, for an X- Ray machine is both awkward and bravely helped the good cause. If the finger of the patient is placed over the hole a splinter can quickly be located rather costly to operate. =

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wae s Se ll -_ ~~ of @©@ OS ££ ft = “NS § SF ST sa eS Paw ee Oo Rew-s- - dred and fifty feet deep Popular Science Monthly oops SER aR a RLS SR This forest of pegs connected by a web of strings gives us a map of geological formation of area represented. The pegs and string indicate plainly sea level and depth and oil sand slope Making a Geological Map of Wooden Pegs and Strings HIS map, which is made of. wooden pegs and strings connecting them, is six feet and five inches wide and twenty feet and six inches long and represents the geological structure of several square miles of oil land in California. It is claimed that, by glancing at the map one can tell the depth of any well, its exact location, the thickness of the various strata found in drilling, the location of the spots where oil and water were found, etc. The pegsare painted white and have colored rings indicating the geological formations, sea level and depth. The strings connect- ing the pegs indicate the slope of the oil land, which is about two hun- on the west side of the fields and three thousand two hundred and fifty feet on the east side, .three miles distant. Chain Armor to Protect the Eyes from Flying Splinters ii ingenious improvement has re- cently been made to the already familiar steel shrapnel helmet in use “over there.” It is designed to protect the eyes and the upper part of the face from splinters of wood, stone, sand and metal, thrown up by exploding shells. : The new device is merely an “\. adaptation of the chain doors : which have been introduced into metal, chemical and glass works in recent years to protect the workers from the heat of the furnaces and the splashes of molten material. It consists of a fringe of sepa- rate short lengths of fairly heavy chain, which effectively ar- test the flying particles. On account of its loose- ness, it does not seriously interfere with the vision. Many cases of blindness This chain visor is designed to pro- ®mong soldiers abroad are tect the eyes from flying splinters due to flying splinters. ie, PERETTI US IES

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As Luck Would Have It

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Pat © Underwood and Underwood Se A Ae On September 14th of last year a British seaplane, emerging from a heavy mist, struck the steel- lattice mast of a wireless station on the English coast with such force that the front end of its body, with the engines became wedged in the lattice work. The pilot was stunned but did not fall and was rescued by sailors belonging to the station Stee eae ee -, aa Goa ad PP oP av ae,

LS ee ee “ y Pa ra When the accident oc- curred, several sailors were painting the lattice work of the mast. One of the men climbed out on the wedged-in seaplane and rescued the unconscious pilot, lying on top of one of the wings, 300 feet above the ground. With the help of two other sailors the airman was lowered to the ground and escaped unharmed

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How Our Naval Falcons Are Unleashed A_ hydroair- This shows plane at the the track, fif- ' moment of be- teen feet a- | ing launched: bove the from a cruis- deck of the er. It rests ship, which ufon a wood- serves for the en car driven launching by compres- of the hydro- sed air power airplanes At the end of the track the wooden car, which weighs about 400 pounds, drops into the water with a mighty splash, while the airplane lightly speeds on its way Photos by Prizma, Inc. The car is recovered by a waiting launch Having completed its flight, the hydro- and towed back to the ship, to be hoisted airplane comes to rest in the lee of the aboard to be used again at the next start ship and is once more hoisted aboard her 649 ne nee

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Boston Converts an Armory Into - Some of the sterilizers which form part of the modern equipment of the new armory hospital a tag dl ddasdlsad shige “iddtbld Each of the twenty-two wards of the hos- pital contains twenty beds and has its staff of doctors and nurses in attendance Ambulances of improved type are im- portant auxiliaries to a hospital and many are required to deal with emergency calls % Z 4 % Vy); y 4 SS

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Wonderful Military Emergency Hospital Gis The upper picture shows how the hospital has been ingeniously built into the big cavalry armory. The lower picture shows members of the medical staff and nurses in a group 651

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Sacred as the Apple of the Oriental’s Eye These are not just ordinary elephants. They’re the sacred elephants of Candy, Ceylon, and are considered very holy. Here we see them taking their daily bath Pigeons and cows are also considered sacred in India. Here we see both standing unmolested Here is the sacred ox resting in a Benares street. Traffic goes around him as he must not be disturbed Photos © Brown and Dawson Monkeys are also held in reverence. They are believed to be inhabited by souls of dead men

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Crowds surround the bulletin boards to read the announce- ments which are posted. up concerning the sugar shortage Firewood was so scarce, that enterprising street vendors sold it by weight to the poor at much enhanced prices With coal at eighty dollars a ton, the poor people in Paris searched every refuse pile for bits of the precious fuel And We Thought We Were Cold and Starving!

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Major H. R. Allen, M.R.C., who has much improved the army litter By straps and slings the patient is held immovably, even though the litter be turned over completely New Ways of Using 4 the Military Hand Litter Tying the foot of the injured side with the left front litter sling. The first step toward immobilization This shows how complete immobilization is achieved, by means of slings, when all extremities of patient are broken 654 Hj LRAN ae St ae ™ a “Sy It ual

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Pitta 9 ey MS sae tis It Can Be Made a Val- uable Help to Surgery Litter with the patient on it is turned to horizon- tal position. Second step toward immobilization » Immobilization is maintained ‘ even though the the litter be car- - by the handles of one side only The litter may even be turned on end with the patient’s head down with- ' out disturbing fractures x» Pps In a case of emergency one man can carry the litter with the immobilized patient on his back without risk or danger 655

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“She Starts, She Reels, She Seems to Fee} An Obsolete Industry Takes a New Lease of Life at Hog Island The upper picture shows how Hog Island, near Philadelphia, is being conv erted into the greatest shipyard in the world. It isa miniature city initself. It will have post-office, Y. M. C. A., theatre, etc., for the use of the employees. The second illustration shows the ribs and framework of an old-style ‘ ‘wooden wall” in making 656

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the Thrill of Life Along Her Keel” ok ease F piaete i fi gad (iis > ct aint Cargo-Carriers in Embryo Here we see the framework of some of the wooden ships that are being built for the French and Italian Governments in American ship- yards up and down the coast ‘ Hull Nearing Completion The art of building wooden ships was bidding fair to become com- pletely forgotten. Then the war came, and wooden ships once more came into their own as transports Photos © C. P. 1. These are the barracks in which the men employed in the new Hog Island shipyard will be housed. The community is complete in every way. It has a Y.M.C.A.,a postoffice, etc. 657

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Were Children and Dogs Barred There Too?

KS we TPR on + , fee Tae. Fy td ae ORR hte ad “Pr. ye; tat OPS PPT me - rt ; vey eeF re * — Onis iis ; This shows a view of the court and the architecture of the oldest apartment building in the world. It was built in a village in the province of Fu-ken, Southern China, about five hundred years ago and has been in use ever since. The ring-shaped building is five stories high and contains four hundred one-family houses All apartments open on the center court, in the middle of which is the cistern, supplying the ten- ants with water. There are no “modern conve- niences” to speak of, but the building is well protected with a strong wall with but a single entrance. There are no windows toward the out- side of the circle. A tile roof covers the structure

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The Savage Headhunters Outclassed they deposited their dead by nailing their bones upon the walls so as to form a decorative design the convent of Floriana, Malta, had a decidedly gruesome sense of beauty. Underneath their church, which was built by the Grandmaster Verdala in 1584, in an arched crypt, © Brown and Dawson The Capuchine monks in (SCSCVVVUVVOUT EE GRee wed ead 4) da jy a ‘ OCG wa @ & B & o a\ = mn : \ : Q

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Were Children and Dogs Barred There Too? eh TRATES rtirrrederitiger iy ae Sates oj | eaiadaaiaremet tia | .. meenaaned wey; 200. Le = , a RE zi 8 ? ® ~ pa 5 Bees lida: 3 eT ET ak eral “Se Saeea * ‘ : ihe “>, Stes pons SY TUS na : Se - fi ay Ls 7 peed TE es te PH trrrrrrr Oh “A This shows a view of the court and the architecture of the oldest apartment building in the world. It was built in a village in the province of Fu-ken, Southern China, about five hundred years ago and has been in use ever since. The ring-shaped building is five stories high and contains four hundred one-family houses All apartments open on the center court, in the middle of which is the cistern, supplying the ten- ants-with water. There are no ‘“‘modern conve- niences’” to speak of, but the building is well protected with a strong wall with but a single entrance. There are no windows toward the out- side of the circle. A tile roof covers the structure

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The Savage Headhunters Outclassed 9 $3; a ee : iy er) anim mY 2 BChiLaRSTTATLART TLE TRL ae Ge Av AS | ae Ge, a a el © Brown and Dawson The Capuchine monks in the convent of Floriana, Malta, urch, which was built by form a decorative design y gruesome sense of beauty. Underneath their ch had a decidedl the Grandmaster Verdala in 1584, in an arched crypt, they deposited their dead by nailing their bones upon the walls so as to

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of Peace Is Resting, but Photos © Int, Film Serv. Carrier pigeons offered to the government for use at the war front are first tried out. They must be wise as a judge, swift of wing and of great endurance to be useful At the training station near Washington, D. C., not only the pigeons but also the men who handle them are trained. The soldier in the picture fast- ens message to pigeon’s leg

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The Doves of War Are Active Enough . : ‘ 4 nee ~ pode enact | Si site 4 te i 4 er ihe Under the control of the Intelligence Bureau of the Signal Corps thousands of carrier pigeons are trained for service at the front. The picture shows a row of cotes and above them pigeons in exercise flight These birds are used to carry messages from the front to the headquarters behind the lines. This picture shows how the capsule containing the message is fastened on to the pigeon’s leg for safe conveyance

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With Drill, Tele. phone, and Electric Implements the Using one of the new electric bul- let detectors. A bell tinkles when the embedded bullet or splinter is encountered Some simple in- struments which are used in prob- ing for bullets or shell splinters in This shows the method of tak- ing radiographs of the human head in the mili- tary hospitals

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Modern Surgeon Salves War’s Human Wrecks Drilling through the skull is made easier and safer by the use of the precision drill. This is far ahead of the old style trephine CASTE Pate EOE ~~ ae AA lt Si PRI SR IS SS This electric cutter is used ‘to great advantage in cutting plaster of paris casts when the doctor desires to remove them The new electric bullet detector is shown here all folded up in its compact carrying case 663

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‘ . inson, a lad of about 664 Popular Science Monthly A Boy Pathfinder Discovers a Bicycle Short Cut in an Irrigation Ditch CHOOLBOYS who live near El Mo- lino, California, and attend school at San Marino, travel back and:forth on bicycles through a half-mile of concrete- lined irrigation ditch. The ditch “high- way” cuts off about a mile of their dis- tance to and from school and enabies them to avoid several tered between Maine and Texas, the Pacific coast of the United States, which has a length of: about 1,100 nautical miles, has only a few harbors which are available as a refuge for ships in stormy » weather. There are no real harbors between Los Angeles and San Francisco, a distance of 367 miles and only five bar harbors, safe in bad weather, between San Francisco and the Strait of Juan de Fuca, mean hills over Las PS ae which no cyclists {j >\\j B43 can pedal. bee Fe Robert Hutch- thirteen years of age, is credited with having discovered the path. His boy- ish spirit of explora- tion led him to take his bicycle in at the upper end, and ride through the ditch. When he found that the other ; aN Trees Stunted by a the Wind OURISTS visiting the Rocky Moun- tain National Park and not afraid of strenuous exercise in mountaineering, often have the op- portunity of seeing tree forms like that shown in the ac- companying pic- ture. The trees 4 end emerged at the San Marino Road he realized he had made a lucky discovery. He told his schoolmates about: it and since the ditch is dry about nine months out of the year, it has proved a great convenience to the pupils of the school at San Marino. This same spirit of discovery has made the world what it is to-day. Lack of Safe Harbors on This dry ditch forms a short cut for the schoolboys of El Molino and avoids hills too near the timber line seldom grow up straight. They crawl along the ground, seeking the shelter and protection of the rocks against the violent North winds. The tree in the picture found shelter behind a big rock and grew strong and com- paratively big, but the height of the rock limited the height of the tree, for it could not withstand the powerful north winds. Our Pacific Coast N a recent publication on “The Neglected Waters of the Pacific Coast,” issued by the Department of Commerce of the United States Coast and Geodetic Survey, the Superintendent, E. Lester Jones, calls public attention to the radical differences be- tween the conditions and char- acter of the shore line of the Atlantic and those of the Pacific coast of the United States. While the Atlantic coast and the Gulf coast have many excellent harbors scat- Only in the shelter of the big rock could the tree grow in the face of strong winds above the timber line

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Constant Friction Made a Freak of Telegraph Key HE peculiarly formed knob in the picture was taken from a telegra- pher’s key used continuously for fifteen years by Mr. W. C. Staib, operator in the general offices of the Popular Science Monthly 665 Banana Fiber Bags for Raw Sugar Containers UGAR planters in the Hawaiian Islands are facing a shortage of bags used as containers for raw sugar.. These bags have been imported from Calcutta. Recently machinery Lehigh Valley Rail- /( road at South Bethle- hem, Pa. It is true, the knob is not of stone, but of hard rub- ber, and was not worn by dripping water, but by the fingers of the operator, but, after all, the cause of the wear in the case of the stone as well as in that of the rubber knob is the same—friction. es 7 was sent to Honolulu from the State of Wash- of manufacturing the bags from the fiber of banana tree tru:ks. Making a Coaster From Roller Skates O boys like coast- ing? Just ask them, or what is even Mr. Staib is suffer- ing from operator's cramp and can now use but one finger in sending. In the course of time his finger, by constant friction, wore a deep indentation in the hard rubber, nearly penetrating it. The other fingers of the operator’s hand, rubbing against the edge of the knob, wore away part of it, giving the knob an eccentric shape. This is just another instance of how a constant small friction will wear out the hardest sub- stances. Everybody knows the time-honored anecdote of the way the rims of the Eas- tern wells are worn out by the soft rope. There have been many instances of the remarkable effects caused by constant friction, but that of the telegraph key is unusual. A Steeri ost Steering p Bolt through Steering post . ait r This key was worn out by a telegraph operator’s finger P Le sport. Homemade coaster made from board and pair of roller skates better, watch them when they have a chance to give them- selves up to that sport. Coasting on roller skates is fun, but coasting on one of the regular coasters with foot-board, steering post and brake is, next to flying, pure bliss. Emory S. Egge, of Montgomery, Ala., who invented the coaster illustrated by the accompanying diagram, has a claim upon the gratitude of the boys, for his invention will make it possible for many who could not afford high priced coasters, to indulge in the coasting The device is extremely simple and can be used with any pair of roller skates. The skates are attached to two blocks un- derneath the foot- board by strap and clamps. The rear block is fastened to the footboard, and the one in front to the steering post. The brake, a plain lever arrangement, is worked through a slot near the steer- ing post. ington for the purpose. -

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Portholes in an Airplane Hull The engines are carried separately and the pilot occupies the fuselage alone A Real Aero-Cruiser with an Enclosed Cabin to Shelter the Crew This new Morane-Saulnier biplane carries two machine- guns and three passengers. Note that the engines are carried not in fuselage or body, as usual, but are in- weight-carrying airplanes appeared which were driven by two engines. But the engines were not housed in the fuselage or body in which the pilot sits, but were actually separated from it. The system has since been improved, as the accompanying photograph shows. As soon as the engines are taken out of the central fuselage or body, new pos- sibilities begin to appear. The designer has full liberty to shape his fuselage as he pleases. Since it no longer need house machinery, it becomes a regular ship’s cabin with portholes. In the accompanying photograph of the three-seated French two-engine biplane which has been designed by Morane- Saulnier works, the last stage in this de- velopment is presented. The plane itself is of rather average size, and yet it is driven by two light but high-powered rotary engines. It must be a speedy ma- chine because of its sheer power and lightness. When the engines are taken out of the central fuselage and mounted between the planes at either side of that Fi weiet in the war high-powered, 666 dependent of it. The fuselage itself is provided with portholes to admit light and to permit observation. The two funnels are used for taking photographs ‘fuselage, there is always a saving in structural weight. In the interest of high speed, the fuselage is made deep enough to enclose the three passengers completely so that they are well sheltered from the icy blast that accompanies fast flying at high altitudes. But how are the men to see? OQb- viously by portholes. And so we find that the walls of the fuselage are pierced with some fourteen portholes covered with artificial mica (cellon). Two of these portholes are set in curious . short funnels projecting from either side. Obviously they are intended to give a lateral view. But the funnels, useless to an observer, serve to house a long-focus camera and to protect it from the wind. Thus it becomes possible to take photo- graphs in any direction. Most of the portholes are used to throw light into the fuselage; only the upper ones are needed for observation. Of course such machines as these could not be used for fighting purposes as they are too unwieldy and too slow of handling. Steen aoaaetr ns Sa ota & SO whl ~*~»

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To Lock the Ends of a Belt, Slip a Pin Through Two Registering Holes IMPLE in construction, easily attached and quickly disconnected is a new belt connector which consists of a hinge with a removable pin. One half of the hinge is riveted to Popular Science Monthly 667 but next to it comes the question as to how best to protect ships from. sinking after they have been attacked by a sub- marine and torpedoed. The naval author- ities of the allied countries are wrestling with the problem of waging war upon the German U-boats, while the ship builders are called upon to one end of the belt, and the other half to the other end. After the belt has been placed over the pulleys, the two ends are brought together, and a rawhide pin is pushed through the alined holes of the hinge. The belt find a solution of the second problem. The accompany- ing two illustrations, showing the extent of the damage caused to French ships by shell fire and a tor- ’ pedo form a power- ful argument in fa- vor of the use of can easily be re- moved by removing the rawhide pin which holds the two parts of the hinge together. The connector provides a flat and flexible, yet sufficiently strong joint for narrow belts. Watertight Compartments to Pro- tect Ships From U-Boats HE submarine war which Germany is- conducting against the Allied Powers has.caused tremendous losses to shipping already and it is generally ad- mitted that the problem confronting the allied nations is of serious importance. The question, how to check the activity d ) d f ? t This shows the effect of shell fire on the plate covering of a merchant ship we ee ge ee ee LAD Saal a aia Push in the pin and the belt connection . is made, forming a strong, flexible joint ments in the con- of the submarines is, of course, paramount f watertight compart- struction of-freight- carrying merchant ships. Ships equipped with such compartments will remain afloat a long time and may be able to reach the nearest port in safety, instead of sinking in a few minutes after the attack as in the case of so many. well- known boats. Photos @ Underwood and Underwood Enormous hole torn in the side of a merchant ship by the explosion of a torpedo or tatpabagpatnsnteeitit

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668 Popular Science Monthly Growing Thirty-Five Bushels of Po- tatoes in a Six-Storied Box ALK about growing potatoes in your back yard! Here is a method by which you can Sun for Ripening Bananas? Cer. tainly Not—Just Cool Them UNSHINE is not in the least neces. sary for ripening bananas. All that is necessary jg grow thirty- five bushels of tubers in a six- by - eight - foot packing-box. It looks like a big pen, but it is a very old thing in the way of potato farms. The western miners have known about it for many years. Now they are pas- sing it on to the eastern folk Lag eer PS ~'g SPC ae to subject them to a heat of about seven- ty-eight de- grees for about eight or ten hours, and then gradually cool them to a stea- dy temperature of about sixty degrees. This quickly pro- duces a pleas- ing golden color, and rendersthe fruit firm andof very desirable The pens are built of heavy timbers and open spaces are left on all sides to permit the plants to force their way through. The “soil’’ consists of rich earth and manure with a mixture of hay or excelsior, and each bed is about six inches deep. Potato plants are placed in the first layer of soil and in each layer until the top is reached. The farm is built on the principle of the apartment house, potatoes growing on each floor. When growing, the plants reach out in all directions, in- cluding straight up. When they are fully grown the pen is taken apart and the potatoes are rolled out of their thin covering of soil with a rake, so that they are not bruised and cut. One bushel of. potatoes is sufficient for plan- ting. A yield of thirty-five bushels to each pen is the rule rather than the exception. This idea might very well be adopted by city-dwellers here in the East, for the large supply would make potato famines non-existent. A potato farm built on the apartment ‘house principle. Each floor is six inches high and contains one layer The swinging “Stop” signal will catch your eye readily and stop you appearance for sending to market. Swinging ‘‘Stop”’ Signal Ate tracts Your Eye LL the fundamental princi- ples of safety first are em- bodied in a signal system for use at grade crossings which has been perfected by a Pennsylvania company. It has three different aspects shown in the accompany- ing illustration. Under normal conditions the “Stop” signal is concealed behind the ‘Look! Listen!’ sign. When a train ap- proaches, however, the “Stop” signal is released and swings back and forth so as to attract the attention. It is a well-known psychological fact that a moving signal is invariably more effective in attracting the attention than a signal which remains stationary. If, for any reason, the signal © mechanism is out of order and fails to work properly, the “Stop” signal drops down vertically and remains in that position, as @ constant warning to all persons approaching the crossing.

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et so. ee FT a ee ee .motor-truck is con- Popular Science Monthly The Vegetable Peddler Adopts the Fast Motor-Truck HE motor-truck is being used in Southern California as a vegetable store on wheels. For some time prior to the use of the truck for this purpose the lowly horse had been used to draw the vegetable wagon up one street and LL automobile 669 New Automobile Muffler Works on Vacuum Principle engineers have ad- mitted that the present type of muffler in which the gases are allowed to expand from a small pipe into the muffler and are then carried back and forth through passageways, is inefficient be- down the cause it in- next, but so creases the much more engine back- efficient pressure is the truck - and prevents for this pur- a rapid exit pose that it of the burned is being exhaust rapidly gases. The taken up by new muffler California is a noise- produce _deadener peddlers. because it Upon the prevents the — regular sudden = truck plat- a pansion o form special- Seow wees ed the com- ly-designed California produce peddlers are nothing if not enterpris- pressed vegetable- ing, and the automobile has, with them, replaced the horse’ gases to the carrying bodies are being constructed, the lower deck being the salesroom, while the upper floor is intended to hold the reserve supply. mospheric pressure enter the muffler lower at- - The exhaust gases perpendicularly and strike against’a small conical ‘surface More than thirty per cent more ground which divides them up into numerous can be covered by one of these vege- table-trucks in a day than by the old horse-drawn ve- hicle. The result is increased profits, a neater appearance and much time saved. The bodies are of the ‘‘quick detach- able” variety, so that it is a common sight to see a vege- table vendor and his family touring on Sundays and holidays. In fact, the money invested in such a When Gases in, Small stream between adjacent yadial fins Out MIE i. 5. Details and general appearance of the new principle, disk-shaped automobile silencer sidered well-spent by the peddler. small streams by means of two sets of radial fins. These little discharges are delivered to the muf- fler exit one by one, since the paths to the opening are of dif- ferent lengths, thus avoiding the noise caused by the ex- plosion of a larger volume of gas. Each small discharge stream is also in con- tact with the muffler walls, so that it is cooled and its volume decreased on the way out. With this muf- fler, the gas engine is able to produce more power and efficiency.

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670 Popular Science Monthly Don’t Let Your Baby Suck the Telephone Cord! s ELLO! Hello! Is this the com- plaint department?” A woman’s voice, clearly in a state of great irritation, judging from the rising pitch and the increasing explosiveness of her utterance, almost screamed these words to the com- plaint clerk of the telephone company. He gave an affirmative answer and, interrupted by queer A New Safety Lock Suitable for Sewing-Machine Treadles ROBABLY the greatest element. of fatigue occasioned by running g sewing machine is that of exerting a con- stant foot pressure on the treadle while the machine is jp operation. To stop the machine, the op- erator is forced to ele- vate the sole and eo, €, crackling sounds, (E and a steady buzz, the voice at the other end of the line poured . a string of complaints into his ear. Bitterly she com- plained of the opera- tor, of poor connec- tions, noises in the telephone and many other things which, to the experienced clerk, clearly spelled a short-circuit some- where on the sub- scriber’s line. Politely he suggested to the woman to examine the green cord of her telephone and to inform him whether it showed a dark and wet spot. “Yes, it does,” came the answer. “Baby was playing with the cord this morning and took it in her mouth, sucking at it for a while. Surely there can be no harm in that!’ The complaint clerk, who had heard the same story many times, was callous. Irate ladies who complained of the service and possessed babies were as nothing tohim. If people did foolish things and then upbraided the company, why should he care? Placidly he informed the complain- ing one that the baby, by sucking at the cord, had caused a short-circuit some- where inthe line. The insulating fabric around the wires, when thoroughly mois- tened, had become a conductor of elec- tricity. He advised the woman to dry the spot by holding it for a while near a hot iron and not to let Baby suck the green cord again, unless she was willing to go to the trouble of drying out the wire every time Baby committed the offense. This shows how baby caused a short- circuit in the line by sucking the cord lower the heel of her foot. In case of run- ning a needle into the finger, the instine- tive motion is to draw away, but she would be forced to make the reverse motion. Mr. Frank B. Gil- breth, of Providence, R. I., an_ efficiency engineer, has _ intro- duced a device which can be advantageous- ly applied to any sew- ing machine where the operator does not have to stop the machine oftener than every four minutes. To start the machine, the operator simply pushes her foot down on the treadle. The hooklike device grasps and locks the treadle. To release the lock, the operator has only to drop her foot from the foot rest shown on to the lever. This knocks the catch off the trea- dle and stops the machine. This device starts and stops a sewing ma- chine without causing unnecessary fatigue é

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trunk and is dril- Popular Science Monthly Even a Parasite May Prove to Be Useful to Man “T)Z-Z-Z-.” ‘‘Bz-z-2z-z-z’’—the buzzing sound comes nearer. It is produced ‘ by the vibrations: of the wings of a most peculiar looking insect. Its body is about two and a half inches in length, with transparent wings marked with dark spots. Hanging straight down from the rear end of the slender body is a thin, hair- like something, about five or six inches long, which seems to interfere with flight. _Clumsily the insect circles around the trunk of the big elm tree. The buzzing ceases. The insect crawls around the trunk for some time before it stops. Without further preliminaries the queer insect raises its threadlike appendage straight up, then curves it in form of a loop over its back, so that the sharp tip at the end of it comes down on the bark. The appen- dage, which seems to have the rigidity of a steel wire, is planted perpen- dicularly upon the ling a small hole into it with sur- prising rapidity. At last the drilling ends. With uner- ring instinct the in- sect, known as the Ichneumon Fly, has located the burrow of another The first picture shows the Pigeon-Tremex, which destroys trees by boring into them. The second shows the Ichneumon Fly which destroys the destroyer, thereby saving the trees belonging to the insect family known as Horn-Tails. The female has drilled through bark and wood with its slender ovipositor until it reached the burrow. It deposits one egg in it. The Ichneumon Fly is a parasite. It deposits its eggs in the burrows of the Tremex and its larvae, which develop from the eggs in a short time, feed upon and kill the larvae of the Tremex which they find in the burrow. It is the female of the Tremex which drills the tell-tale holes into the bark of our shade trees and deposits eggs in them. The larvae which come from these eggs burrow into the heartwood of the tree unless their career is cut short by an Ichneumon larva. Reducing the High Cost of Build- - ing with Camouflage Lions OS ES HAMBUR- GER, of Los An- geles, built himself a new house, and his soul lusted after lions to guard the portals thereof. Accordingly he had built nice inexpen- sive bodies of laths, fitting them with faces of concrete. Then he planted Virginia creeper with the result that he now has ~ % insect, the large Pigeon-Tremex, This ferocious lion is made of laths and two Virginia creeper—cheaper than bronze magnificent camouflaged lions.

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Popular Science Monthly

Look at it, guess what it is and then read the accompanying article. It isn’t a centipede or snake Have You Ever Found a Thing Like That? ISITORS to seaside resorts on the Atlantic coast occasionally find in Mexico.

which indicates the place where in due time the young individuals developing from the eggs wil] make their exit. When laying these long strings, the gnaij goes beneath the surface, and, as the ribbon begins to be formed, it appears above the sand, slowly increasing in length until the whole of its two or three feet of length are formed. Each capsule contains a number of eggs. The family of this creature is repre- sented by about eight species, from Cape Cod to the Gulf of The snail’s shell is often more than one foot long. Lofty French Observation Point Near Dixmude NE of the essential duties of a soldier is to keep constant watch upon the their strolls along the beach, especially movements of the enemy. High trees after a storm, strange- ly formed objects like that shown in the accompanying pic- ture. What is it? Many a stroller has asked himself that question, without being able to answer it. The first guess usually is that the queer-looking thing is of vegetable origin, probably some sea- weed. Few suspect it to be of animal origin. This object, which almost has the ap- pearance of a frilled “boa,” is the egg-case of Fulgur Carica, a sea snail. The egg-case con- sists of a series of flattened capsules, at- tached by one edge to a cord. Each one of the capsules shows, opposite the place of attachment, a more . transparent spot,

eueeee- ‘

(BOSE se tee. ay & Fam eer eaw a 2 A French soldier is on observa- tion duty way up in the tree-top

and tall buildings are, naturally, the most suitable places for the establishment of observation posts and are given preference wherever they are available. The tree in the picture, which may still be standing somewhere near Liux- mude, was used by the French soldiers, perch- ing securely among its top branches, as observation post to good advantage. The tree, < magnifi- cent specimen, tall and of generous girth, made it possible for the French observer to get a fine view of the German lines. A ladder gave access to the observation post. Even a small crib was arranged ‘near the top, where one of the observers could sleep, while his comrade kept watch.

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am SY 2. ee et OS or Smoke Your Own Hams with This Portable Smoke-House HE German hausfrau has her own smoke-house which she uses in con- nection with the domestic stove. It is practically a large sheet-iron can, with a neck at the bottom of suitable width to fit the stove. Inside it is divided into two com- partments. A partition is placed on one side which connects at the top _with a perforated plate (wire gauze would prob- = >more ably do), and at the bot- tom with a solid plate | forming the bottom of cornparmes: ff the chamber. ‘The smoke passes up through the connecting tetonsmoe MS pipe, up the back passage, down ‘through the per- forated plate into the smoke-chamber, and thence through the out- let into the chimney. Any dirt or soot or cin- ders are intercepted by the perforated plate. The apparatus is used on the kitchen stove, with a small, slow-burning fire and any suitable smoke-producing material that is at hand. Perforated top plate \ Partition Just the Thing for a Kitchenette —An Electric Cooker I OUSEKEEPING in a modern apart- ment, although its space economy is carried to extremes, can be simpli- fied by the use of the portable . cooking box invented by Mr. Leoline Edwards, of Twick- Removable top Pas | YA i Taw a Cover wy Sheet iron Expanded cork Popular Science Monthly This smoke-house is used on the kitchen above with a small fire 673 enham, England. It is essentially an improved ‘“‘fireless cooker” of simple construction, in which the heat necessary for cooking, baking, boiling or broiling is supplied by an ordinary incandescent electric lamp. The cooker is eighteen inches high and twenty inches square and weighs thirty pounds. It consists of two iron cases, one inside of the other, but sepa- rated by a thick filling of expanded cork. Through a hole in- the lower part of the box the socket of ee an electric lamp is passed, pememmo“''c’ which may be connected , & with any convenient plug or lighting fixture. To the socket an ordinary ‘electric light bulb is at- tached inside the box. Above the heating bulb several shelves are ar- ranged, so that several dishes may be cooked at the same time. The cooking box may be opened by the housewife at any time for the in- spection of the contents, which cannot be done with the ordinary ‘“‘fireless cooker,” for the lamp will soon replace any lost heat. Pity the Salt Industry: It Makes Little Profit RECENT investigation by the Bureau of Mines proved that a salt famine in the United States is unlikely. At the same time it was established that owing to the low price of salt and the abundance of its supply there is but little profit in the salt industry, al- though the American salt works have sup- plied in recent years practically all the salt consumed in the United States. What a pity— for the profiteers—salt Diagram and method of use of a homemade electric cooker. It is a kind of improved “fireless cooker,” simply constructed is not usedin munitions! ply a

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Popular Science Monthly

a picture, bearing upon the answer in the frame. Still lower is a question in ° French, with the phonetic equivalent and English translation, together with the French answer and its phonetic equivalent, but without translation, That answer is repeated within the frame near the top of the card with the next higher number. At the bot- tom of the card there is some ~ grammar comment and vocab- <~y —_sulary and so forth. SSN Number One reads the question on his card; Number Two reads the answer ag given on his card, with its English translation, and in turn, follows with the question to be answered by the next player, and so'on until the cards are exhausted. The holder of the joker can ask any player one of the ques- tions upon his card.

Members of this party are studying French by means of a special American- invented card game. The cards are shown held in the hand at right

Parlez-vous Francais?—If Not, Learn They Hung Little Jessie on the

How with Playing-Cards Clothesline to Dry N ingenious Amer- HE little girl on ican inventor has the clothesline ig recently put on the mar- not a victim of Boche ket a card game inven- ted by him, which is designed to teach French, or at least the rudiments of the language, by means of a game played with a special pack of sixty- one cards. The cards are num- bered from 1 to 60 and in addition there is a “‘joker.”’ Each card has printed upon its face a top line giving some French word or phrase, with its phonetic equiv- alent and an English translation. Under that, in a frame is, in French, the answer to a ques- she fastened the little tion printed on the card — toddler to the clothes- with the next lower A future story: “When Mama line by means of her dress number. Under that is hung me out on the line to dry” and some clothespins. atrocity, as some might imagine. She’is a little American girl, and the condition of suspense in which she finds herself is merely the result of a happy inspiration. It was wash-day and the mother was extremely busy. The little girl also had been busy around the tubs and being a trifle unsteady upon her tiny feet, she fell into one of the tubs which, luckily, was filled with cold water. The mother was too busy to change the child’s clothing and so

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Trapping Salmon in the Far North > The people of the North spear thousands of salmon in dammed streams By Christian Leden The salmon are caught in stone traps after which they can be speared with the Eskimo Kakimaks or three pronged forks. The Eskimos catch thousands of fish in this way MONG many Eskimo tribes, sal- mon fishing is one of the most important means of existence. The natives along the West Coast of Hudson Bay fish for salmon the year fround, only varying their methods to suit the chang- ing seasons. In the Summer, the salmon in the ocean, just beyond the rivers, are caught in primitive nets. During the Autumn when the salmon leaves the salt water the Eskimo builds several stone walls across a river, leaving one stone out in each di- vision, except in the wall highest up. This leaves a free passageway for the salmon as it goes up the river with the incoming tide. When the tide turns, the Eskimos close the openings in the lower walls, and at the ebb, they wade out into these small compartments and spear the trapped salmon with their Kakimaks or salmon- spears. This slaughter of salmon takes many days. They get many hundreds— sometimes thousands—of salmon in one river. Later in the Winter, when the ice has formed on the lakes, holes are cut in the ice through which to angle for the salmon. This is done by attracting the salmon with a little piece of walrus ivory carved to look like a fish. The decoy is kept mov- ing by the help of a line of deerskin sinew. When the salmon approaches to examine the little imitation fish, he is speared with the Kakimak that the Eskimo holds in his right hand. In Spring, when the poor salmon gets rather hungry, it is easily caught with a bait and fishhook. Then, even the women go out and angle for the harassed fish, through the holes in the ice. It is fortunate for the inhabitants of that in- hospitable region that salmon are plenti- - ful there at all times, at least sufficiently so for the simple wants of the Eskimos, otherwise times would be very hard. Those of us interested in science, engineering, invention form a kind of guild. We should help one another. The editor of the POPULAR SCIENCE MONTHLY is willing to answer questions. 675

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Three Automobile Bodies in One Here is a car body that can be changed on the road to any of three styles The Body in Process of Transition and in Use as a Runabout The changes are made by the use of a folding and sliding superstructure. When the car is used as a runabout this is slid back and swung down on a hinge into the rear seat portion of the tonneau. To change toa landaulet the superstructureis raised to a vertical ¥ HICH automobile do you like W best?” Ask a woman and she will name the one with the body that most appeals to her. Ask a man and he too will express his taste in terms of the body. For the body is the most exposed part of the car; it expresses a car’s individuality. As a result, there is a greater and greater demand for bodies of distinction or for those which have some particular feature that the greater number lack. With the demand for better looks in automobile bodies has come an equal demand for greater comforts as expressed by convertible bodies which can be thrown open to the gentle breezes in the balmy spring days or closed and heated in the bleak winter months. One of the most ingenious automobile. bodies designed to fulfill these conditions of individuality and comfort is that shown in the accom- This is the convertible body as it appears when it is used as a coupé position and side panels are opened out from the front portion of the body to enclose the sides. The coupé is made-by sliding the entire top forward in slots that are provided, in the sides and swinging up a rear deck from under the rear seat to fill up the space left panying illustrations. It is really three bodies in one, for it enables the car to be changed in a few minutes into a run- about, a landaulet with the driver out- side and the passengers in their own com- partment, or a coupé with the driver and the passenger on one enclosed cross- wise seat. These transformations may be made on the road at any time and with- out the addition or removal of any parts, whereas in. the early days of body design, such transformations would have neces- sitated the employment of three separate chasses, each with its own particular body. The met@morphosis is accomplished by using a sliding and folding superstructure. This can be folded down and concealed, or raised and used in either of two positions, thus forming three distinct types of car. The advantages of such a body as this are.obvious. One has a universal car, suitable for all occasions, and all weathers. Showing how body is changed from coupé to landaulet by sliding top back All the specialized knowledge and information of the editorial staff of the Popular Science Monthly is at your disposal. Write to the editor if you think he can help you. 676

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Popular Science Monthly The Very High Cost of Writing Letters AVE you ever figured out the cost per letter of your business correspon- dence? Taking into considera- tion the cost of stationery and stamps, the salary of the stenographer, cost of all ac-. cessories to the typewriter, all overhead charges, and last, but not least, cost of time of the man who dictates the let- ters, it works out at forty cents per letter, and that is an absolute minimum! That Elusive Keyhole Simply -Must Be Found HERE are times in the life of most jolly good fellows when they find it quite difficult to find the exact geo- graphical location of that narrowly cir- cumscribed opening into which their latch key is supposed to fit. But even persons not included in the class of good sports often have difficulty to find the keyhole, particularly at night or in cases where the door is located in a dark hall or corridor. The key hole guide invented and patented by Ernest E. Brown of Waukegan, IIl., is designed to give relief in all cases where the finding of the key- hole is, for any rea- son, connected with difficulties. | These guides, which form a kind of trough with sides slanting toward the keyhole, are ham- mered into place over the regular doorplate, and conduct the key unerringly to the key- hole with absolutely no effort at all. Prongs bent back over door lock — . 1: aac 4 ae Sag] “——~a | / = Sides slant in? 3% toward keyhole Showing construction and application of the handy keyhole trough herein described Why this formidable-looking array of pipes? Just in order to separate. natural gas from oil Oil and Gas Mix, and So They Are Separated Out West ANY oil wells yield both oil and gas so, with such a plant as is shown, the flow is forced directly from the well into a large main pipe. The gas separates from the oil and rises to the top of the pipe, passing over through the small inverted U-shaped pipes and into the smaller main. For many years natural gas in oil wells was considered a nuisance and was allowed to waste, but now, on account of its fine heating, fuel and power qualities, large investments are made to conserve and utilize it. The:day of the picturesque burning gas well, lighting the country at night for miles around as an ad- vertisement of a na- tural gas region, is practically a thing of the past. Such a spec- tacle israrely seen now and when it does oc- cur it is looked upon as an example of poor engineering. Natural gas is, nowa- days, a valuable com- mercial commodity, and a number of cities useit exclusivelyin lieu of coal gas for heating, lighting, and power purposes. It is, of course, much cheaper than coal gas.

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Making Animals Transparent We used, as children, to read about invisi- ble cloaks. G. WELLS once wrote a striking H story about an invisible man, who owed his invisibility to the fact that a method had been discovered of rendering the refractive index of his body to light exactly the same as that of the atmosphere. In other words, his body became absolutely transparent and ~hence invisible. _ Perhaps the principle may be better understood if we consider the case of a glass tube. Ordinarily the tube reflects lights and objects. Placed in water, the tube becomes much more transparent; but placed in a liquid having the same index of refraction as the material of the glass, the tube is hardly visible at. all. On the other hand, “ground glass” is opaque because the rays of light are bent; the surface of the glass is so _broken up that the separate rays of light do not pass through in a direct line at all. That Wells was not merely romancing is strikingly demonstrated by. the accom- panying photographs Read how a rat got his “‘ cloak”’ which were made for the POPULAR SCIENCE MONTHLY with the consent of Doctor Harmer of the British Muse::m. The trustees of the Museum applied tc the proper British authorities for permission to use the discovery disclosed in a German patent granted to Hermann Streller of Leipsic. Streller actually patented what appears to be a valuable process ‘“‘for rendering organic and inorganic bodies transparent and translucent” by juggling the refraction of light in the way pro- posed by H. G. Wells in his story. The rat that Doctor Harmer treated passed through more than one solution before he was reduced to comparative .transparency. .First of all the rat was stripped of his fur overcoat. Reduced to stark nakedness, he passed through solution after solution. Like all other animals, a rat consists largely of water. This was removed and he was immersed in weak alcohol. Gradually the alcohol was strengthened until the water was all expelled, and the rat was practically pure alcohol. Then a fluid was intro- This rat has been rendered partially invisi- ble by the chemical treatment of his body Here are three objects—opaque, semi-trans- parent, and transparent. Note the rat’s bones 678

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duced which mixed equally with alcohol and with oils. Eventually the rat was converted into pure benzol in order to get rid of the alcohol. At any given stage he was filled with some liquid to prevent him from collapsing. Finally an air pump was used. He passed through a vacuum into the liquid with the same index of refraction as his own. The vessel containing the liquid was then sealed. It is of course impossible to obtain absolute transparency. The different parts of an animal’s body have different indices of refraction. But it is possible to make certain groups of muscles dis- appear if their index of refraction is known. A mixture of three parts of salicylic methyl ester and one part of benzyl-ben- zoate is a liquid which has an index of refraction corresponding with that of most animal tissues. According to Pro- fessor Spalteholz, human bone can be re- vealed by using five parts of oil of winter- green and three of benzyl-benzoate. The Weight of This Dumbbell Can Be Changed EELING particularly strong and vigorous this morning?—Add an- other pound or two to each of your dumb- bells. You can easily and quickly do that if you own a set of the variable weight dumbbells recently invented. As may be seen in the diagram, each end weight is rounded and attached to the handle section by a long machine bolt with coun- ter-sunk head. By unscrewing the head sufficiently it is made possible to insert one, two or more 9 extra weight-disks be- tween each end piece and the handle section. The extra weights are slotted: so that they may be slipped into place without entirely removing the _ end- piece and screw bolt. After the bolt screw has been tightened the curved flange holds them so that they cannot slip. Now all you athletes, go ahead and rival San- dow. Popular Science Monthly This dumbbell can be adjusted to suit the “pep” of the user A new hoeing machine which imitates well the strokes of the human arm It Does the Work of Four Men— This Hoeing Machine HOEING machine, invented by Otto F. Ullman of Severy, Kansas; operates several hoe-blades simultane- ously. It does the work of three or four men armed with hand-hoes. Only one man operates the machine. The hoe-blades are fixed to the lower ends of arms suspended from a crank- shaft. Bars extending from the hoe arms to rocker arms at the rear of the machine regulate the movement of the hoes, imitating the strokes and motions of an ordi- nary hoe worked by hand. The crank-shaft that drives the hoe-blades is connected by a chain, sprocket- wheels, a_ gear-shaft and gears with the main or driving axle. The device may also be arranged to be driven by power from a small gaso- ing engine, but it is not very hard to run by hand.

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Housekeeping Made Easy A mahogany chiffonier having one drawer made into a handy writing desk A portable electric nitrogen bulb radiator made in the form of a ‘steam or hot water radiator. Cleverly de- ~ Five ash trays signed cig- in holder for arette box the smoker’s shown above private den An immersion electric heater which cannot burn out is shown at the left in use in a tumbler The book rest shown below makes reading Requiring practically : in bed more pleasant no effort in operation, this sweeper collects all crumbs when pushed over the table-cloth The utensil shown at the right is made of porous material and serves as a refrigerator by the evaporation of water through the sides

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Housekeeping Made Easy This suction cleaner is mounted on large casters with ball bear- ings and rubber tires for moving it about easily from room to room The delivery of china .is made much more efficiently’ and ‘with © less damage by the use of a special padded trunk shown at right Acurtain stretch- erframeisshown below which has an attached ea- sel to hold it instead of stand- ing the. frame against the wall ers woes eng Attractive molds for making the mud pies which are so much enjoyed by most youngsters Butter making ona smallscale is tiresome but this machine greatly lessens the unpleasantness Different types There is nothing quite so enhanc- ing to the kjtch-; en as a handy cabinet nicely enamelled white of stands for smokers, which are three feet high and finished in natural. colors

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682 Popular Science Monthly This trick bottle is made especially to “soak”? movie actors over the head The Bottle Breaks, But Not the Head of the Villain REATHLESSLY the spectators are watching the be- ; recently invented ‘“‘break-away”’ bottles, For a long time artisans in the motion. picture industry have tried to devise g transparent “‘break-away”’ bottle, that ig a bottle which would have all the prop. erties of glass except that it would not cut or scratch. Until recently the bottles used were made of an opaque substance which would shatter readily, but which was not transparent. The problem hag at last been solved in the modeling de partment of the Balboa studio in Calj- fornia. William Dummer, chief of that department, has invented such a bottle, The material from which it is made, a combination of ether, gelatine, resin and oil, will crack and break like glass, but it will not cut and may be shattered over the head of the hero without in the least marring his manly beauty. And, what is equally important, it is transparent. This Pocket Drinking-Cup Folds Up Like a Purse S a matter of sanitary precaution | every man, woman and child should carry an individual drinking cup. The health authorities have long recognized the importance of permanently banishing the unhygienic and wilderingly rapid de- velopment of the dra- ma on the screen. The hero, singlehanded, de- fies the villain and his henchmen, while the heroine, whom he pro- tects, is hiding her face. Neither she nor the hero notices the sneaky ‘‘Greaser,’’ who, armed with a big whisky bottle stealthily approaches the hero from behind. The descending bottle breaks into bits over the head of the hero, who drops in his tracks. But, do not fear; the bottle was actually broken, but the hero remained unscathed. het \ disgusting publie drinking cups and have strongly urged everyone to carry his own cup. One of the difficul- carrying out this re form was the lack of drinking cups that would fill the require- ments of hygiene and be so fashioned that they could easily be carried in the pocket. The cup shown in the picture consists of two aluminum plates, con- nected by a_-strip of oiled silk folded in bellows fashion. The edges of the aluminum plates are _j) folded over the edge The Mexican’s deadly weapon was one of the This cup is made of aluminum and oiled silk and can be folded up flat of the silk and crimp- ed tightly. ties in the way of | Ome 7 HH SA Soe oO OS eh pew ieee kes OFS OFS bebe, beek eee’ FTP

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Popular Science Monthly The site of this building was excavated from a hill-side, and the -building comprises- garden, garage, tennis court for both night and day and skating rink A Garage, Tennis Court, Skating Rink and Garden in One LFRED AUDET, a Salem, Mass., man, has constructed for his use a combi- nation garden, garage, tennis court and ice skating rink. This roof garden is built into the side of a hill in the rear of the dwelling. The hill was apparently a barrier to further development of the property, but it was eventually an ad- vantage. The garage space is hollowed out of the hill. The garage measures thirty-eight by- seventy-seven feet.and . comprises six separate houses to accom- modate three cars each. Every compart- ment is thirteen by thirty-eight feet, with electric lights and hot water heating. The dirt taken from the hill was placed on the roof of the garage for the tennis court and garden. Electric lights permit play at night. A wire netting thirteen feet high set in the large cement posts prevents balls from landing in the street below. _ Besides the tennis court there is a spacious garden which makes a veritable bower of beauty. A pergola thirteen feet square and lighted by electricity is a feature of the garden. The roof of the garage and the base of the tennis court and garden are of cement, ten inches thick. The whole ‘makes a novelty in construction that is a delight to the many suburbanites who have seen it. Utilizing the Waste Heat from a; Gas-Engine OR a long time the waste steam from steam-engines has been turned to good account, but there have been diffi- culties in the way of using the exhaust gases from a gas-engine as they readily attack the metal of the conduits. How- ever, the difficulty is being overcome, for a New Jersey candy factory has an installa- tion in connection with a sixty horse- power engine which is used to heat the factory. The gases pass through an economizer made of cast-iron, with the passages to the different sections staggered so that all parts are heated for the whole length. Water circulates in jackets sur- rounding the gas passages.

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684 Popular Science Monthly Enjoy Your Snapshots Better by Enlarging Them F you are an amateur photographer with a hand camera for making only small pictures it will add a great deal to your enjoyment Grocery Store Has Combination Front and Awning HEN William Judd built his gro. cery store at Avalon, Santa Cata- lina Island, he had to have a front to the place, and he algo of them if you can enlarge them or, still simpler, look at them with an enlarging con- trivance like that shown in the pic- ture. The device is merely a five- inch concave- ground mirror set upright in such a manner that it re- flects the picture facing it. needed an awning, So, instead of go- ing to the expense of providing both, he combined the two. Mr. Judd con- sidered that he awning when his store was closed, and when it was open he didn’t need a front. So he set to work and built The frame of the mirror is hinged to a board, which forms the base of the device when it is in use. Three slots, for obtaining three degrees of enlargement, are provided in the base and hold the picture to be en- larged. No focusing or adjusting is necessary. Looking at snapshots with a lens is always interesting for it gives them “depth” and perspective. The camera being a one-eyed instrument, the photo- graphs lack this in the ordinary way. The lens-mirror remedies this. Frame and case are covered with black leather- ette, and the whole device folds up to a package one inch in thickness and six inches square. Amateur photographers who have used this contrivance have found it a valued part of their equipment. This concave mirror enlarger gives ‘“‘depth” to your snapshots without trouble or expense a rather substantial awning on a frame that works on hin- ges attached to the building. The awning is provided with hinged legs swung to the lower edge, which fold upward when it is lowered. At the end of the day it is only neces- sary to fold up the legs, lower the awning, and lock it. When time to open the store in the morning, the front is unlocked, and raised into place to serve as an awning. This arrangement is very neat and very convenient, but it appears to be only suitable for mild climates, and among strictly and universally honest communi- ties, as its rather flimsy construction would not keep either weather or persons out for long. So Mr. Judd’s novel groc- ery store front attests the confidence.he has in Avalon folk. didn’t need an Here is the latest thing in grocery store fronts, well adapted to warm climates. When the store is open it is a very effective sun-awning, and when the store is closed it forms the front wall

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Cleaning Billiard Tables by an Electric Brush SHE cloth of billiard and pool tables takes up a great deal of the chalk dust that drops from the cues. How can it be removed without ruining the cloth and without merely raising it into a cloud that settles again upon the cloth? When vacuum cleaners came into use, many owners of billiard halls tried them upon their tables, but unsuccessfully. The powerful suction loosened the cement between the slate plates Popular Science Monthly forming the bed of the table and in a short time wore off the nap of the cloth. An electric brush, hy which was invented by ress Mr. Dolph L. Lowery of Sandusky, O., avoids the undesirable features ‘of the vacuum cleaner. The contrivance has the appearance of a large flatiron and moves on swiveled wheels over the cloth. A small electric motor furnishes the power for a rotary brush in the front part and a suction fan in the housing in the rear of the motor. Loosened by the \" itl S, — C ee | 0 ae . ay H + ae This rotary brush and vacuum cleaner cleans billiard tables ‘without damage which, nevertheless, may upset the ac- curacy of the table to a noticeable degree. A Pair of Socks Every Thirty-Five Min- utes—Red Cross Knitters Please Notice HE enormous a 4 oS bristles of the brush, the chalk dust is drawn through a tube to the center of the fan and blown into a bag connected with the fan housing. The excess air is al- lowed to pass out of the bag through strainers which hold back the dust. As all billiard players know, it is , ae absolutely essential eam that the surface of ‘ the table shall be perfectly true, and great difficulty has been hitherto experi- enced in cleaning the cloths, as even a soft brush is likely to raise the nap and cause an infinitely aS ‘ ‘ : } © Western Newspaper Union hirt Patriotic women are operating knitting socks every thirty- demand for sweaters, scarfs, - ete., for the Amer- ican soldiers and sail- ors made it clear that this war work needed speeding up. So the Comforts Com- mittee of the Navy League of the United States installed in its headquarters several knitting machines and turned them over to the women. Even the most ex- pert knitter cannot knit much more than one pair of socks a day, while a machine like that shown in the picture, if skill- fully operated, can turn out one puir of small unevenness, machines to speed up the war work five minutes.

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The Richest Food in the World Solving the food problem with the Soya Bean ; sp By Hudson Maxim vs € Hudson Maxim is the inventor of smokeless powders used by the United States army and ' ye navy. He is America’s foremost authority on high explosives. As a member of the a Naval Consulting Board, he has given up much of his time to the consideration of war + inventions. The food problem seems to him the most important of all, and here he it suggests a method of using the Chinese soya bean in solving that problem.—Editor b: N my book, “‘De- employed, which . fenseless Amer- can be devoted to f ica,” published raising some of the Ww three years ago, I most nourishing bi called attention to and* valuable of the defenselessness foods, provided ct of this country, but that the market tt in that book I price and means of fc dealt mainly with transportation were n our lack of prepara- such as to make the a tion in respect of work profitable to t! fighting men, fight- the farmer, t ing ships, and all Throughout the 1: the munitions and South, especially, | d military equipment Hudson Maxim is now turning his atten- are large areas E of war. All my con- tion from explosives to the study of foods which have been , clusions in that abandoned because y book have been most emphatically veri- of the cotton boll-weevil. These areas Z fied by results since our entrance into the could be very profitably employed in rais- i present war. ing a great variety of foods not at present i But there was one very important phase cultivated to the extent which they ought | ] of our unpreparedness for war which I did to be raised. Among these the principal | ‘ not mention and that was the food prob-_ is the Chinese soya bean, a food which is ’ lem. The provision and distribution of so rich in fat and protein as to outclass food has proved to be one of the main problems of the war, and the solution seems farther off than ever. Present tendencies indicate that the time is near when the production and proper disposition of food to our own people, to our Allies and armies over-seas will be the most baffling task which we shall have to accom- plish. The food problem is a three-in-one problem — first its growing, second its transportation, third its con- sumption. There is enormous acre- age in the United States, not at present profitably a ee ee ae = a Here we see the soya bean being handled in quantity in its native country. Note the peculiar topped baskets 686

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the popular beefsteak in nutritive value. But the soya bean is unlike the com- mon American product in that it requires special treatment in its preparation to make it suitable for human food. I have been studying the soya bean for several years and have succeeded in producing a soya bean product which I call So-Soya. This product is a food-conserver, because it is not only highly nutritious in itself, but because Popular Science Monthly 687 By merely adding hot water, So-Soya makes: a delightful soup. Hot milk thickened with it makes one of the most delicious soups. that could be desired.. A plate of it makes a meal for most persons, such is its nutritive value. Mixed with cold potatoes in the pro- portion of one part So-Soya to three parts potatoes and heated either with or with- out the addition of a little milk, a dish is made that is a it adds nutri- tive value to food with which it may be mixed. Thus it be- comes possible to use many foods of low nutritive value and to give them: the nu- trition they lack by the ad- dition of my products. When mixed with almost decided im- provement on the usual form of re-heated potatoes. Used as. a thickener for all kinds of gravies and meat sauces, it improvesthem. . In all kinds of dressings for meat and fowl it serves as‘a most decided improver. Ordinary any other food in the’ world, it improves The beans must be ground in producing the new * food. Mr. Maxim is putting beans in the machine round steak, chopped fine, mixed with both its taste and nutritive value. The food is prepared in the form of a very dense, stiff paste, somewhat re- sembling pea- nut butter in So-Soya in the proportion of three parts of ~ meat to one of So-Soya, thoroughly incorporated, and broiled like an ordi- nary steak, is at once both most general ap- pearance, but So-Soya being a complete food it is far more palatable in the pure state than peanut butter. The following are some of the most im- portant uses of this new food concentrate. It may be eaten on bread, crackers or toast, or with potatoes, without any previous treatment. It makes excellent sandwiches. By mixing together equal parts cow’s butter and So-Soya, the butter is doubled in quantity and for the purpose improved in taste. Mr. Maxim believes that the soya bean products will eventually appear on every breakfast table delicious and tender. An ordinary beef shank stew, made by cooking the meat until it falls to pieces, then thicken- ing it with So-Soya, makes a dish that thas a flavor somewhat resembling ter- rapin. Ordinary tripe, boiled until thoroughly done, with onions and butter added and cooked until the onions are done, and finally thickened with So-Soya, makes one of the best and most palatable dishes of all.

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688 So-Soya is especially adapted as an all- round Army ration. There is no one thing on which the soldier can march longer and be sustained than on So-Soya, and there is no one thing that may be eaten more continuously with relish and without cloying the appetite than So- Soya. The reason for this is that it isa well-balanced food and one that partakes of the combined properties of vegetable, fruit and meat and is therefore satisfying. Lest it be thought that I am trying to advertise So-Soya through the editorial pages of the POPULAR SCIENCE MONTHLY, I may state here that the product has not been put upon the market, and as yet I have taken no steps to that end. I have been negotiating with the Government in an attempt to get the Government to manu- facture the food and supply it to the Army. For this purpose I have offered the Gov- ernment the free use of my inventions in foods during the war, if they . will utilize them for any purpose they see fit. The burglar commences warily to climb the stairs but he reckons not on the stair alarm The Burglar Makes a False Step HE night is dark . and cold. Some- one is stealthily mov- ing in the shadow of a residence. When the policeman, patrol- ling the beat disap- pears around the corner, a man, with his face muffled, slinks up to a house. ‘‘What a snap!’ he murmurs. Drawing a few skeleton keys from his pocket, he begins operations upon the inner door. The lock, a plain one, yields in a few moments. He enters the pleas- antly heated hall. He knows his ground, Just as he touches the fatal step the little burglar-alarm, which is shown herein detail, operates Popular Science Monthly knows where the stairway is that leads to the second floor, knows how to get to the room on the second floor where the family jewels may be found. Softly he feels his way to the stairs, There is the first step. He raises his foot and plants it upon the first step. Ina moment the scene is changed as by magie. Stairs and hall are illuminated by a flood of electric light and—‘‘Curse it!” snaps the startled burglar, as he hears the resounding din of a big electric alarm bell, loud enough to awaken everyone in the house, “that means git in a hurry or they’ll nab me!’”’ He turns and quickly makes his exit without standing upon the ceremony or order of doing it. It was his first step ° on the stairs which had caused all . this | trouble. He knew where the stairs were but he did not know that the first step was hinged on a spring hinge so as to break an electric circuit while the step was not in use, and closing the circuit by the weight Spring strap hinges Hinged panel Contact point Open circuit for electric bell )) ss (bel has! fo Lf sini | ae Contact plates Caattery BS of a person pressing the three contact points of the movable part of the step against the corresponding contact points of the base underneath. The electric current thus put into action automatically switched on the lights and sounded the alarm gong, informing the whole house- hold of his undesired presence.

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- Dummy Ships That Fooled the Germans Their ‘“‘suicide fleet”? of imita- tion dreadnoughts a huge joke Because of their utter helplessness in the event of attack, the British naval officers who knew of this wooden hoax referred to the fleet as ‘‘The British Suicide Squadron”’ noughts’ by Great Britain, some days ago, to form a breakwater, brings up more evidence of what disposi- tion is being made of the dummy fleet of fourteen battleships with which Great Britain fooled Germany for some fifteen months during the earlier part of the war. This titanic war jest, which was re- cently exposed by Lieutenant Henry Clay Foster, with the consent of the British Admiralty, completely deceived not only the Germans, but the English people themselves. No one in England was able to explain how the Germans could claim to have sunk the Agamem- non at the Dardanelles, when the Admiralty had admitted, officially, the sinking of only the Goliath and ‘‘some supply ships.” Germany rejoiced over this supposed sinking of the Agamemnon. But they must have wondered why the turrets and “guns” of the sunken dreadnought floated, for days, in the Dardanelles. Lieutenant Foster states that the “| a0 sinking of two wooden ‘dread- 689 dummy battleships were converted from old third-class passenger ships of the Canadian Pacific Steamship Company, which were enrolled in the English Navy. In an Irish port, says Lieutenant Foster, the dummy battleships were painted in exactly the same hue as the vessels of which they were counterfeits. Canvas was stretched over the decks and painted gray, and the upper decks and equip- ments finished in every detail to resemble the Grand Fleet ships so that any foreign aviator—or any British one, for that matter—flying overhead, would never suspect he was looking down upon any other than a member of the Grand Fleet. Turrets and guns were all made of wood, with a careful exactitude in their outer color and finish. There was nothing real about the ships, so far as war pur- poses were concerned, except the brass trimmings, which were kept shining, as on a battleship, and some lifeboats, in which the crew were required to drill. The ships had neither speed nor defenses. Not one carried a real gun. :

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Jumping Through an Aerial Bonfire One of the most sensational episodes of the great war By Carl Dienstbach HE great war has led to many radical changes in the me- thods of warfare. Some were discontinued alto- gether, others modified, still others greatly de- veloped. The trench-war- fare, which reached a higher development than ever before, naturally in- fluenced the artillery tac- tics and led to an extensive use of observation bal- loons. . These balloons, which were and still are used on all fronts, are essential for directing the fire of the artillery and have amply demonstrated their usefulness. The de- struction of the enemy’s balloons is one of the most important tasks devolving upon the aviation branch of every army. It might be said that it is part of their daily routine to seek and, if possible destroy, by gunfire or aerial bombs, the observation balloons which direct or correct the fire of the enemy’s artillery. It was one of those attempts to destroy an.enemy observation balloon on the Italian front which led to one of the most sensational episodes recorded during the great war. One of the allied flyers, having ignited the gas of the hostile balloon, dashed with terrific force through the fiercely blazing bag and, although dis- abled by the shock, succeeded in landing safely behind his own lines. There is nothing “very sensational or romantic in the circling of an airplane around an airdrome, while on the other hand the most daring fiction has never invented and pictured anything half as wonderful and sensational as was that daring dash of that allied airman clean through a burning hostile observation Collision was inevitable. The airplane dashed clear through the burning balloon 690 balloon, three thousand feet above the ground. It was another incident de- monstrating the dramatic possibilities and the ele- ment of romance in fly- ing. Four ally flyers at- tacked the hostile ob- servation balloon, which was guarded by three air- planes. While each of the allied flyers engaged one of the hostile flyers in combat, the fourth flew straight for the balloon, opening fire with incen- diary bullets at short range. So intent was he upon the destruction of the balloon that he mis- calculated the distance. When he found that it was too late to avoid a col- lision with the burning balloon, the daring air- man put on full speed and, withour hesitation, dashed _ straight through the fiery monster. The wings of his airplane were broken by the shock but the stays and braces held them long enough to enable him to glide down to safety behind the lines of the Allies. Tattered pieces of the bag of the balloon were still clinging to the wings of the airplane when it reached the ground, grim evidence of its sensational dive, unparalleled in the history of aviation. Had the fabric not yielded, or had not the gas been ignited before the collision, this airplane would undoubtedly have shared the fate of the Austrian airplane which, a short time before the beginning of the war, accidentally rammed an Austrian dirigible, was upset and crashed down in flames, entangled in the folds of the burning balloon. complete disaster. The result was- Cl er ee ca oo a «=O » ola ca iin | ete

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Popular Science Monthly © Underwood and Underwood Before the war this part of the Belgian border contained the most beautiful country roads, shaded by magnificent old trees which the retreating Germans cut down by the thousands A Beautiful Section Laid Waste by War’s Iron Heel Bend part of Flanders which is lo- cated between the Belgian border and the Somme river, was known before the war as one of the most fertile and beautiful agricultural districts of northern Europe. When the British undertook their drive toward Cambrai, the retreating Germans tut down thousands of the trees lining the country roads and placed them across the roads to hinder the progress of the British. The Lawn Roller Be- comes a Weapon of War LTHOUGH conceived primarily as a war machine of unlimited pos- sibilities, the invention upon which J. L. Hy- land, of Min- nesota, recent- ly obtained a patent, canalso lay claim to a wide range of Not a lawn roller; but a machine which protects the soldier from gun fire as well as from liquid fire usefulness in times.of peace... A hollow cyl- inder, approximately seven feet long; has'a shaft or axle around which it can berotated. To the ends of this shaft a steering frame is fitted, similar to that of a lawn roller. By means of the steering frame the roller with its contents -may be rolled toward the enemy by two or more men, who are protected from: gunfire’ by . the roller, which is to be kept: between them and the enemy. One or more machine guns may be mounted on the outside of the rol-' ler or placed inside of it, so that they can: fire through openings in the steel cylinder. When the roller is to be used as a convey- ance for men, either fighting’men on their waz to the front or wounded men to be taken back of the lines, .a stretcher is suspend- ed from the shaft by means of hooks, or a semi-cylindri- cal structure with berths for three men is suspended from the shaft, so that it will swing freely while the cylinder is re- volving.

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If the truck becomes mired, it is equippe1 with a power-winch to pull itself out NLY a few years ago the plan of establishing a regular freight-carry- ing service with ‘big motor-trucks over a distance exceeding fifty or, perhaps, seventy-five miles, would have been con- _ at all. sidered extremely visionary if not im- Foday a large manufacturing concern in Akron, O., maintains a regular possible. freight service by five-ton motor -trucks between Akron and Boston, a dis- tance of 740 miles one way or 1480 miles for the round trip. Theconcern manufactures automobile tires and rub- ber goods and has a_ great number of branches in cities along the Eastern seaboard. To these it must deliver goods regu- larly and promptly. The inability to get cars when needed often meant that some branch wouldrun out of tires and would be compelled to refuse busi- ness because it could not Truck Service Overland Congestion of railroads and scarcity of cars causes long-haul motor truck service to be instigated By Joseph Brinker deliver the goods when a call came, There seemed to be little prospect of an improvement in the situation and, fearing that the railroad congestion would eventually make it impossible for the company to carry on its business, the heads of the corporation decided to employ a number of large motor-trucks to deliver its goods to all of its branches east of the Mississippi River. They fully realized that it would cost more to ship tires cross-country by trucks than by rail, but they would rather pay the additional cost and continue their busi- ness than shut down and do no business Nothing is more expensive than doing no business. The expenses of main- taining the factory and the branches eentinue, as do the interest on the in- vestment, de- preciation, etc., whether one tire or a thousand tires are made a day. The trucks now in oper- ationmakethe: 740-mile run between Akron and Boston in four days, whereas it On the way. This is one of the trucks which make the seven-hundred-and-forty-mile journey across country to Ventilator Oliding door Details of bunking facilities. The crew sleep right in their machines 692 took from ten fourteen ~ days to make the shipment by railroad. When this saving from six to ten days..is con- sidered, it may readily be seen that it pays the company to stand the ex- tra cost of truck trans- portation which is prob- ably somewhere between seventy - five cents and

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one dollar a hundred pounds for each hundred miles. While the war brought about the con- ditions which made necessary the use of motor-trucks over such long hauls, it also has been directly responsible for the success of the _ Popular Science Monthly 693 reason that from Pittsburgh east through Gettysburg and Philadelphia they follow the Lincoln Highway, the same route over which the government trucks run. One of the 314-ton trucks of the Akron concern made the 533-mile run between Akron’ and New undertaking dur- ing the winter of 1917-18. Between forty and fifty thousand motor- trucks will be delivered to the government. dur- ing 1918. These will be run over- land on their own wheels from the points of manu- facture to the points of shipment on the eastern sea- coast. Close to one thousand of these trucks have York in sixty hours total time and forty-nine hours actual run- ning time, or at the rate of almost eleven miles an hour for the entire journey. It crossed the Alle- gheny Mountains after a heavy snowfall and with the temperature at thirteen degrees below zero. A truck-driver that’ can accomplish already been driv- en overland since the: beginning of the year. The government has demanded that the roads over which trucks have to tun must be kept cleared of snow. The states of Michigan, Ohio, Pennsylvania and New Jersey have risen to the emergency and despite the unusual snowfall they have kept a clear cross-country highway from Detroit to New York’ all winter. This has made it possible to operate the Akron-to-Boston trucks with but few interruptions on account of snow for the The roads are good, but the grades are sometimes rather steep. Look at this hill this is no novice, and has to be equal to any emergency. See that Your Garage Is Ventilated. It Is Dangerous Otherwise URING theexceptionally cold months of the past winter, many deaths by poisoning from the exhaust of gasoline engines were reported from all parts of the country. In most cases the victims had been, for some time, in a poorly ventilated or unventilated garage or other room where one or more gasoline engines were running. A careful investigation has estab- lished beyond doubt that death in these cases was not caused by the exhaustion of the supply of oxygen in the air, but by the carbon monoxide, an extremely poisonous gas, which is generated by the incomplete com- bustion of organic’ sub- stances. It is one mole- cule each of carbon and oxygen combined. Only ; Map showing route followed by the fleet of motor-trucks which is plying regularly between Akron, Ohio; and Boston, Mass. thorough ventilation will remove the danger.

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Youngsters are safe on the beaches with this round float Swimming Harness Will Keep the Kiddies Afloat O the numerous devices for the protection of children and grown persons against the danger of drowning a new one has . recently been added, which offers seme notable advantages. It consists of an inflated circular tube or tire which is fastened to the’body of the person using it by a harness arranged in such a manner that it prevents the buoyant tube from slipping down or over the head. The device has considerable buoyancy and will prevent the sinking of any person wear- ing it. The harness is strong and simple and cannot get out of order. It is a boon to youngsters who are just learning to swim. Cook Soup, Coffee, and Beans in One Vessel N unusually compact and practical mess kit, suitable for soldiers, camp- ers, automobilists and hunt- ers has recently been placed on the market. The kit con- sists of ten pieces, cleverly nested. It weighs less than two pounds. Alcohol in solid cubes is used as fuel. A glance at the accompany- ing illustration shows that the lowest two sections of the kit, set up ready for use, form the stove. Set into the upper part of the stove, so that the heat of the burning Popular Science Monthly — When closed this cooker is seven by four inches fuel can reach it at bottom and sides, ig a boiler for making coffee. On top of that boiler is another boiler which receives itg heat from the steam of the boiling liquig below and which is intended for heating soup, vegetables or any other kind of food, A shallow pan forms the top and may either be used for warming some food = which does not require much cook- ing, or may be turned over and used as a cover. When nested, the kit makes a compact parcel, nearly seven inches ig diameter and less than four inches high, held together by a strap which serves ag qa handle. The Large Amount of Food That Goes Up in Smoke AVE you ever thought how much of the country’s food is consumed by fire rather than by human beings? One fire which occurred recently in a grain elevator destroyed 700,000 bushels of corn and 300,000 bushels of oats. Frequent explosions in grain sepa- rators also ‘cause an enormous loss of foodstuffs. ment of Agriculture investigated such ex- plosions and found that as many as tena day occur in the Big Bend country of the Northwest. Barns which have faulty ventilation are another source of food loss by fire because spontaneous combus- tion of hay and grain is a common oceur- rence in such places. Sparks from loco- -._ motives cause innumerable fires in grain fields resulting in an incalculable amount of damage every season. Much damage is also caused by dropping glowing ashes from cigarettes or pipes, the real cause of more fires, in both city and country, than most people think. Gro- cery stores which carry in- flammable merchandise, such as kerosene, are another fire hazard. Many of these burn each year, de- stroying a large amount of food. Stable fires which de- stroy cattle affect the meat supply of the country,—an important item at present. The United States Depart-. E ; | mie cts © ome kf Oo

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ct & oo —_ «ese = ee ee GS ehh Ulf VRS AE Planting Tobacco with a One-Man Planting Machine THE old way of setting-out tobacco, tomato, cabbage, and similar plants, was to wait for a showery day, when the ground was damp, take up the plants, and feverishly and laboriously go over the ground with a ‘peg’ and replant them before the ground got dry again. Now, however, there is a machine on the market that does away with all the waiting, all the feverish haste, and all the attendant backache. In addition the plants are better planted, and very few are lost through withering, while the output is several times that of the old method. In operation the ground is laid out, and barrels of water placed at convenient places in the field, together with boxes of plants. The large cylinder of the ma- chine is filled with water, and the operator takes the machine and a basket of plants (which can be slung around his neck for convenience) into the field. He stabs the point into the ground, drops a plant down the smaller tube and releases the trap. This. inserts the plant into the soil and at the same time waters it and presses it down firmly. As the machine irrigates the plants as it goes along, it is unnecessary to watch the weather as formerly, and plants that are set out in dry weather do as well as those Popular Science Monthly es & Int. Fila Serv. Roller-carrying frame which enables a boat to be launched from a listed ship - Rolling Down a Ship’s Side to Safety in a Lifeboat SHIP which is torpedoed rarely sinks on an even keel. Whether it lists to. starboard or port depends on the location of the injury. rush to the high side, clamber into the lifeboats, and drop to safety if they can. The crew and passengers We say “If they can’’ because frequently that are set out in the damper weather. The machine does away with all the body-racking, backaching stoop- ing over that used to make setting- out the béte noire of all market-garden- ers. Consequently more pains are taken by the men, as it is no longer a hated job to be gotrid of as quickly as possible. In other words, it is a device of this kind that makes the boats strike not the water, but the iron plating oftheship’s side. To prevent just such accidents, a new method of launching life- boats has been in- vented. A cradle frame is attached to the outside of the lifeboat near- est the ship. If the ship lists, the life- boat rides down the ship safely on little rollers with which the cradle frame is provided. ‘the frame and its rollers also serve to keep the boat at a market gardening a pleasure. The machine, slung around the neck, sets and waters the plants simultaneously safe distance from the sinking ship.

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696 Euclid Never Thought of This Way of Studying Geometry a study of geometry, especially of the more advanced branches of spher- ical and de- scriptive geom- etry makes demands upon the imagina- tive power of the students. Perspective drawings upon the blackboard are grasped on- ly by the more gifted students. Mr.J.O’ Hara Carson, who is connected ‘ with a manual tzaining school in:New Orleans, found that the students had no great difficulty in learning -the theorems, etc., so as to pass their examinations, but he noted that many were unable to practical application of ‘principles accurately and con- structively. A careful study of the subject convinced Mr. Carson that many of the students could not perfectly visualize geometrical Popular Seience Monthly work. various make a Our illustrations contrast the two methods of teaching . geometry has New Uses Hav¥é Been Discovered for Blue Glass Electric Lights N a, uses are constantly being found for the blue glass electric light ip. can descents which already have a wide “range of uses, A big laundry in the South installed blue bulb lights for the reason that this light makes the yel- low stains ‘in cloth show up plainly, and therefore enables the workers to do better laundry In: the West a large mining company uses blue glass lamps overconcentration table as this light assists in’ bringing out the: liné between the zinc and ‘iron ore. A Picture Frame and Easel for the | “Girl I Left Behind Me’”’ ‘7 geometric figures drawn on a plane surface . and that it was this fact which made it impossible for them to apply geometry practically. So he invented several models. - The illustrations accompanying this article clearly demonstrate the construction of these models. The planes may be made of wood, paste- board or any other suit- able material, the lines of wire or strings. To differentiate between HIS photograph frame is for the soldier boys. The triangular flaps are folded back, and the loop ribbon pro- vided is slipped around the corner of one of the flaps. The oval opening is large enough to accommodate a pic- ture 134 x23 in. The photo- graph is slipped between the frame and its back through a slit at the top. lines to be proved, con- struction lines and im- aginary lines, different color- ing or different material may be employed. These models will also be useful in teaching geometry to the blind. The first illustration shéWs.the simple “principle of the a frame, the second its appearance with -a photograph- ~

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Popular Science Monthly

An ingenious adding device that can be operated on the same principle as a dial on an automatic telephone. Simple Adding Machine Conve- nient to Handle ITH no keys to press and no levers to manipulate, the simple adding machine shown in the accompanying . illustration is particularly adaptable to the work of accountants and bookkeepers. The device consists of a base with seven notched dials representing cents, dollars, and tens, hundreds, and so on up to $99,999.99. The device operates on the same princi- ple as the dial on an automatic telephone. For instance, if you wish to add $3.64 and $42.80, you place the pencil-like stylus » a. which comes with the machine, opposite -s-figure 3 in the dollars column and turn the dial to.the right as far as it will go. Similar movements are made for the 6 and the 4 in their respective cents columns. In- sidé“each dial is a large notch or win- dow and the figure 3.64 will be found reg- istered in red figures in. these notches in the first three dials from the right. If $42.80 is registered in like manner, the total will appear in red fig- ures on the four dialsfrom the right. = For sub- traction the same princi- ple is used, ~ except that eel the totals are \ shown on the white figures. The machine can also mul- tiply. HOT GASES UNDER. TAR KETTLE, AND UP OUT OF STACK

» 8 t ee ’ ws e , » lin ai Combination tar and gravel heater device in operation. ‘The furnace is fired from the gravel end It is adapted to the work of accountants and bookkeepers | Heating Tar and Gravel Separately But in One Operation MULATING the famous hunter of the olden days who killed two birds with one stone, a New Jersey mant- facturer has recently brought out a com- bination tar and gravel heater that heats these two dissimilar materials quite inde- pendently but with one operation. The device, which is shown in the accompany- ing illustration, is particularly fitted for street paving where block pavements with tar joints are laid. ~The apparatus consists of two main parts, a rectangular tar kettle and a Y-shaped gravel-bin, with a furnace extending beneath. both parts, from one end to the other. The furnace is fired from the gravel end of the device. The smoke and gases escape through’ an ordinary stove pipe in the kettle end. The inside of the gravel heater is triangular-shaped while the outside is made up in steps consisting of perforated metal plates. The Y- shaped. top acts as a reservoir bin and the gravel feeds down the steps and out at the bottom. The perfora- tions in the step plates al- low the moist- ure in the gra- gpd vel to escape STERN ESCAPE readily as it ss is turned ‘into 5 LD ) steam by ‘the < ae heat of’ ‘the fire, thereby making it pos- sible to heat both tar and gravel. mF AS GRAVEL BIN FURNACE

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Popular Science Monthly Training Sea-Gulls to Become ‘*Spotters’’ of Submarines \ | AVAL officers have frequently had the opportunity to observe that swarms of sea-gulls follow in the wake of sub- marines. The birds are attracted by the unusual spectacle of a whalelike monster moving through the water, and are eager to, pick up garbage. This observation which, in a few in- stances during the present war, is said to have led to the timely discovery of the dreaded proximity of a U-boat, suggested to Dr. A. D. Pentz, Jr., of New Brighton, N. Y., the plan of training the gulls to follow in flocks in the wake of subma- rines. He suggests the use of a hopper, fifty-four inches long, made of sheet steel. It is securely bolted to the top of a submarine and filled with chopped fish. This bait is released from time to time by the turning of a crank operated from the inside of the sub- marine used for training the gulls. The bait, which would naturally rise to the surface of the water, would attract the gulls and cause them to follow the submarine. Gulls, which have been fed from a submarine, get the habit of watching for the underwater craft, and thus reveal their presence to the watchful eye of the enemy Insulating a Hot Rifle for Bayonet Use PPRECIATING the fact that arifle barrel, heated with much rapid fire, is not a particularly inviting article to handle, and that neverthe- less it must be handled when it is required to use the bayonet, Mr. Henry Brewer, of Connecticut, has invented an insulating device. The insulator consists of a perforated metal shield, a little more than semi-circular in cross-section, and suffi- ciently larger in diameter than the barrel to form an insulating space. It is not at all in the way of the user of the rifle, and as it is merely attached with two or three screws, it does not in- terfere with the proper clean- The inventor asserts that in view of the perforations. in the plate it will give a much better. grip. than it was possible to obtain before, as, manifestly the hand wil! not slip on the rough plate the way it would on the smooth, hot, rifle barrel. This insulating shield will enable a man to grasp a hot rifle barrel without discomfort or slip- ping when he makes use of his bayonet Ventilating openings a ing and care of the rifle., FOP NES TT

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The Mechanical David Centrifugal force propels the bullets towards the enemy with terrific force, at the rate of 20,000 a minute out so many striking reversions to The Lombard gun is based upon the i ee present world war has brought hundred feet, a noteworthy achievement. primitive principles and methods principle of centrifugal force. A disk, of attack and defense that the invention twelve inches in diameter; which is rotated of a gun based upon the same principle that enabled David to lay _ low the mighty Goli- ath, should, by rights, cause no particular surprise. The gun, which is shown in the accompanying illustra- tion, is the invention of Levi W. Lombard of Boston, Mass. Its general appear- . ance is more 5 that of a feed \| cutter or coffee- mill, but it is 20,000 projec- ; Diskqun Looking down into the hop- said to be cap- "per from which the bullets SS able of firing are fed to the rapid-fire gun Builet and ~ at the rate of 20,000 revolutions a minute, has a curved ridge from its center to op- posite points of its periphery. The ridge has a groove on one . side, which forms the channel for the bul- lets. These are fed from the center of the disk, one at every V~ groove tiles a minute with sufficient force to revolution and are expelled by the centrif- penetrate steel plates three quarters of ugal force of the revolving disk. ‘The an inch thick at a distance of several bullets leave the gun all in the same Photos ©) Int. Film Serv. The disk of the gun may be revolved by an elec- tric motor, a gasoline engine or by hand power - 699 plane, but not all in the same direction. They come through a slit in the casing of the re- volving disk, which represents about five degrees of the per- iphery. Actual tests have shown that the linear velocity. of the _ bullets (2000 feet per second) is greater than the velocity of the disk. It is stated that, no matter ‘what may be the speed of the disk, the bullets always come out at the same place. This result, which involves compli- cated mathematical and me- chanical problems, is obtained by the feeding mechanism and the peculiar form of the curve of the grooved ridge. One sof the illustrations shows a top view of the feeding hopper. The gun may be revolved by an electric motor, a gasoline _ engine or by. hand power.

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*700 Beware! The Tanks are Goming— Under the Table UR picture shows a toy tank with its young commander. This is a most realistic toy, although it is very inex- pensive. .The sides and body are made of wood, and the gun turrets are merely other scraps of wood nailed to the sides. The gun ports are drilled obliquely sO ‘that the guns point forward. Ordinary pa- per cigarette holders serve as guns—fired in a most realistic manner by inserting fireworks into them. These toys have no motive power, as they are primarily intended for the very little folks, but they make fine stage properties in sanguinary play-room battles. They are not dangerous even for youngsters. Novel Idea of Converting Shell-Cases into Shoe Protectors RENCH life is extremely hard on shoes. That has been definitely proved. Rough usage and exposure to mud and water quickly wear them out. Fora long time the men in the trenches have tried to devise some method of prolonging the life of soles and heels. It was a bright and happy idea of Uh Here is the toy tank in full ac- tion. Note the gun being fired Popular Science: Monthly of the shoes and tacked ‘or screwed down. " The illustration shows a pair of shoes thus metal-soled and heeled and the tools used in doing the work: It is scarcely necessary to state that ‘both the British and the French authorities encourage : this economy in shoe materials. ' Sun Than Away From It? ‘THY isthe air gen- erally much colder a mile above the ground? The heat of: the atmosphere comes from the sun, but by a somewhat indirect process. * The incom- the‘dry air at: high levels, on its: temperature. In amount of water vapor (water in the form of gas), and this sub- stance has a relatively large capacity for absorbing heat from.sunshine. Lastly, the earth absorbs all the heat that falls upon it, and then gives it back, by radia- tion or conduction,: to the air above it. Thus the atmosphere is mainly heated from below and not from above. Air heated near the ground tends to rise, but it cools rapidly in rising. As it ] reaches higher levels some French soldier to use discarded shell- cases to strengthen the heels and soles of his shoes. The plan proved thoroughly practical, and soon many other French and British soldiers imitated the example of the inventive poilu. The shell cases are cut open lengthwise and rolled flat. Then the pressure upon it is less; it expands, pushing away the sur- rounding air, and it uses up in this work some of the energy sessed in the form of ferred to by scientists This explains why the heat of summer often seems to come the soles and heels are cut out with strong shears to fit the shape © Int. Film Serv. A pair of shell-soled trench shoes and the tools used in doing the job properly up from the ground, rather than from the boiling‘ sun above. WhylIsn’t ItHotterNearer the ‘ earth'than near the ° ing sunbeams are only *: slightly -absorbed by’ : and: so have little effect - the: lower regions of the - atmosphere there is al- ” ways a considerable: ' that it originally pos-: heat. This processis re- as “adiabatic cooling.” . BERET RT

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Folding Steering-Wheel Locks Auto- mobile and Makes It Easy to Get Out HE latest comfort-giving automobile accessory consists of a folding steer- ing-wheel which performs the dual purpose of making it easy for the driver to get into his seat and of locking the car in place so that it cannot be steered if thieves should attempt to make off with it. Folding steering-wheels are not new; neither are steering wheels that can be locked. However, the combination of the two is a new idea of greater simplicity than two sep- arate devices. Instead of the entire . wheel sliding about the top of the post as in Popular Science Monthly J This picture shows the side window. being fitted to the automobile body Showing how the windows are stowed to prevent rattling when not in use most folding wheels, the one shown is hinged at opposite points. The. rear half may be swung down and under to permit the driver to stand erect between his seat and the wheel instead of having to slide into his seat. Here is a new combination folding steer- ing-wheel and steering-lock for your car Carrying Automobile Sedan Parts Without Rattling ANY of the convertible sedan auto- mobile bodies carry the side window - and door sashes in pockets in the body sides and doors. The result is consider- able car rattle, especially when the car is traveling over rough roads. To offset these difficul- ties, several manufacturers are making the glass panels integral with the frames ‘so that they \ may be entirely removed and : ‘ placed in a wider and roomier , compartment back of the rear 7 seat, as shown in one of the ac- / companying illustrations. Liberty Motor-Cycle to te Worthy Follower of Liberty Airplanes ELL, we have the Liberty engines, the Liberty airplanes, and the Liberty motor-trucks. Now we are going to have Liberty motor-cycles. The motor- cycle is one of the most important factors to the intelligence departments on ac- count of its speed, handiness, and ability to go where an automobile cannot. Ac- cordingly arrangements are being com- pleted to standardiz® them and turn them out in vast numbers, like other necessaries. :

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702 Popular Science Monthly An Enterprising Photographer ‘* Shoots”? Draft Army T was an event to be remembered when the 10,000 men, forming the New York contingent. for the High-Water Street Cars Recently Used in Cincinnati HEN the Ohio River is on a ram: page, the streets in the lower sec-: seleetive draft army marched in parade on Fifth Avenue, New York City, on Wash- ington’s Birthday, during a_ blinding snowstorm. In spite of the unfavorable weather, photog- raphers managed. to get many excellent - pictures of the parade. Particularly interest- ing were the motion- pictures.taken by an enterprising motion- picture concern which obtaified the views in a novel manner. often flooded and many times traffic on the car lines has had to be stopped. Toremedy this con- dition the engineer- ing department of the traction company de- vised the high-water cars shown in the ae- companying illustra- tions. The car bodies are placed upon tres- tles resting upon the wheel trucks, so that the floors of the cars are about five feet above the level of the By special permission a giant tripod, tower- ing high over the heads of the marchers and the multi- tude of spectators, was set up at the inter- section of Fortieth Street and Fifth Avenue. From this strategic spot the camera-man, who mounted the tripod with his camera made an excellent and complete record of the parade as it passed that point. Draft army parade photographed in New York on Washington’s Birthday street. The front car furnishes the power with its motors up high and dry and communicates it to the car wheels by means of sprocket chains. The trailers are similarly raised and three steps give access to them. These cars are capable of making their way through water of a depth of five and a half feet and are giving great satisfaction. tion of Cincinnati, ix: the leve? district, are! SS ee Ea Cincinnati’s high-water cars, specially designed so that car ahd running gear are all out of the water. The cars can run in five-and-a-half feet of water and operate in flood-time 0 c fi 8 fi U c i ] ( 1

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PO MM ERIM Popular Science Monthly a great pile of coal in flames at Superior, Wis. Extinguishing Fires in Coal Piles with Bicarbonate of Soda T has long been known that as the re- sult of spontaneous combustion fires often originate in the interior of large coal piles, especially when the coal is fine and contains a large percentage of sulphur. Some of the recent coal-pile fires: have demonstrated, however, that under favorable conditions spontaneous combustion is liable to take place even in piles composed of coal in large lumps. It depends principally upon the nature of the coal and upen the amount of rain to which the pile is exposed. ‘John A. Thomas, of Columbus, O., who made a special study of spontaneous combvstion, is the originator of a simple and effective method of extinguishing such coal fires. The application of his method has prevented enormous damage _in_ several instances, where fire had originated in large accumulations of coal. Mr. Thomas uses a strong solution of bicarbonate of soda, which he throws upon the burning coal-pile by means of a force pump. The carbon dioxide, released from the soda puts out the fire. The gas is assist- ed by the water which, by the heat of the burning coal, is transformed into steam. The illustration shows the burning coal- pile at Superior, Wis. A considerable This remarkable picture, which looks so much like a glorious sunset or cloud effect, is in reality It was finally put out with bicarbonate of soda part of the 100,000 tons comprising this pile was saved by Mr. Thomas, after the fire had been raging more than three weeks in the interior of the pile. Why It Is That Bricks Are Made with Straw VERYONE is familiar with the story of how Pharoah commanded his taskmakers to increase the burdens laid on the Israelites by withholding from them the straw wherewith to make bricks; and doubtless many have won- dered wherein the hardship lay. By most people, probably, the view has been held that the straw was added as a binding material, much as hair is used in mortar; but such an explanation is scarcely satis- fying when it is remembered that the straw fiber isa very weak one. Alexander Findlay says in his ‘‘Chemistry in the Ser- vice of Man” (Longmans, Green and Co.): “About fourteen years ago it was found by Dr. E. G. Acheson, to whom we owe the discovery of carborundum and the process of making artificial graphite, that when clay is mixed with a dilute solution of tannin, it becomes much more plastic, and the strength of the dried brick is, moreover, greatly increased. Although straw does not con- tain tannin, it was found that -when straw is treated with water, the extract obtained has the same action on clay as tannin has, the plasticity of the clay and the hardness of the brick being greatly increased.”

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Popular Science Monthly Shooting a hawk from a motorcycle while riding at forty-five miles an hour. A highly successful method of killing birds, employed by an enterprising Los Angeles taxidermist Shooting Hawks from a Fast Motor- cycle While Traveling at Speed VERETT COLBURN, a Los An- geles taxidermist, has evolved a new method of hunting hawks and other birds of prey which is spectacular and hazard- ous, but nevertheless efficient. Mr. Colburn, who is also a motor- cyclist, noticed that often when he was touring over the country highways, hawks would frequently sit on telegraph or fence posts at the side of the road and allow him to pass on his machine. They had The Windows Fold Back Out of the Way and Let in the Air NEW type of casement window, shown on the house in the accom- panying lilustration, overcomes several of the ills that casements are heir to. While the windows are held rigidly at both the top and the bottom, they may be easily moved from side to side. When shut they make a tight, weather-proof joint. Thus there is an unobstructed opening when the windows are opened and a real window when they are closed. come to regard the machine as a harm- less thing. So, by way of experiment, he constructed a bracket on the top of the gasoline tank of his machine for carrying a shotgun. Then he set out over the highways to see what results could be obtained. The first bird sighted was a fine red-tailed hawk that sat on a fence post. As the bird flew from the post, Colburn, speeding at forty- five miles per hour, Almost any style of finish that is pos- sible with other win- dows may be used, including the divi- sion of the sash into small panes or fitting with art glass. ~ Slid- ing screens placed on the inside next to the screens are used; the shades and dra- peries are placed in- side the screens. This allows the ad- justment of the shades without open- ing the screens, and . also prevents the shades and draperies from being blown grabbed his gun and killed the hawk. This casement window is weather-tight and is easy to open and close. It does not rattle outside when the window is open. TTS

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A Floating Invitation to Suicide It’s a mine with an _ imitation periscope projecting from the water the lookouts on the starboard side, excitedly pointing to a small object a few hundred yards away, which his keen ~ and well-trained "P ite tookou in sight!’ calls one of is the invention of a foreign officer now working for the United States Govern- ment and proved to be highly effective in the early part of the war, until the com- manders of vessels eye has just dis- cerned. A dozen glasses are trained upon that object a moment later and as many ob- servers, firmly con- vinced by what they see, that they have the periscope of a hostile sub- marine before them, begin to fid- get in anticipation of the coming events. The first impulse of the offi- cers of the ship is to head straight for the periscope and to ram the submarine to which it belongs. The captain, had learned to curb their impetu- ous impulse to ram everything that looked like a peri- scope. A large metal cylinder holds a firing charge of five hundred pounds of tri-nitro- toluol, wet gun- cotton or dyna- mite. Bolted to the lower end of the cylinder is a weight to keep the mine upright and so far submerged that only the tubu- lar firing device, simulating a peri- scope, shows above the surface. knowing that in The trigger ends the early months Ships will do well to steer clear of this imita- are in the top of of the war eighty tion of a periscope; to ram it means exit British ships were sunk because their impetu- __ 'mitation periscope ous commanders thought *ploder arms that periscopes are always Sulphuric acid associated with submarines, Priming charge does not yield to the rash impulse of his officers, but — Explosive decides to try a shot at the periscope first. The second , shot hits it squarely and rotation there is a terrific explosion. It was a mine—not a sub- marine—a mine, equipped with a seductive imitation of a periscope designed to lure on overbold vessels. An at- — Submersion weight tempt to ram the supposed submarine would have been Charged with Cable eye "TNT. wet measure to the value of the - the periscope-like device. The trig- ger is so arranged that any pressure upon it causes it to break a bottle filled with sulphuric acid. The acid sets off the priming charge in the lower part of the tube, and this causes the explosion of the main charge of the mine. Of great import&nce is the vertical fin attached to the outside of the mine. It acts like the rudder of a ship and prevents the mine from spinning around under the influence of wind and wave action, which adds in a large fatal to the ship. The mine gun-cotton or dynamite invention. 70 5 peat nna NT SONNE AIA

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Popular Science Monthly The seat gives the baby just the right height for comfort at the dinner table This shows the con- struction of the seat, which may be compactly folded up How to Change an Ordinary Chair Into a High Chair for Baby L. FARRER, of Welland, Ont., had . three little children of high-chair age in his family, but only one high chair. This set Mr. Farrer thinking and eventu- ally the idea of constructing a contrivance for temporarily changing a low into a high chair took definite form in his mind. After a number of disappointing attempts he evolved the invention pictured. The contrivance consists of a wooden seat which can be attached to the back of an ordinary chair by hooking the heavy wire connected with each folding armrest over the back. By turning the spiral of the hooking arrangement the height of the seat can be adjusted to the require- ments of the child using it. When the seat is not in use it can be folded up so as to take but little space. e Feeding and Watering the Chickens Automatically ON’T scatter chicken feed by hand. It is a waste of time nowadays. Nikilas Lappas, of Salem, Massachu- setts, has patented a machine which does the work and never forgets. At regular intervals his apparatus delivers measured quantities of water and feed for poultry without the aid of a human hand. The barrel shown in the accompanying picture contains water which drips from the spout very slowly into the tilting bucket below. A suitable valve regulates the rate at which the water drips into the bucket. It takes eight hours for the bucket to fill. When full it tilts and dumps the water into a trough. From the trough the water’ flows to a basin, from which the chickens drink. Attached to the weight suspended from the tilting bucket are bells which jingle as the bucket is overturned and remind the chickens that meal time has come, quite in the best boarding-house style. The feed is likewise supplied at regular intervals automatically, from the large can which sur- mounts the apparatus. It flows through a spout into the hopper, and thence on to a curved delivery plate which scatters it in all directions just as if it were thrown out by hand. The tilting of the water bucket when it is emptied supplies the motive power for operating the device and once started it requires no attention. Here is chicken-feeding reduced to a system. Water and feed are automatically dealt out

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“ Fruit Skins Are Utilized Now. This Machine Does It N apparatus which will dexterously AN peel everything from limes to large grapefruits (the first stage in the extrac- tion of useful oils from the peels) has been developed by the experts of the Depart- ment of Agriculture. With a battery of these machines Popular Science Monthly 707 Them There Pesky Tobacco- Chewin’ Bugs Ag’in HILE tobacco is recognized as a valuable insecticide which will kill most insects, there is at least one that lives in it and on it and thrives exceed- ingly—far too exceedingly, to be pleasant. This tobacco beetle, as he is called, is very epicurean placed in a fac- tory, many thousands of dollars worth of by-products can be utilized. ~Unlike other peeling ma- chines, the fruit does not have to be sorted to fit into the grat- ings. Fruit of all sizes and shapes tumbles down through © in his tastes and prefers the bet- ter brands of tobacco. He is anative of Cuba and the Philip- pines, but has spread all over the world. He only lives in manufactured and stored to- bacco, never in the growing plant. There’ are ae an opening in . the storage box on the top of the apparatus and falls in between the flights at the end of a long horizontal screw. This screw is revolved by a motor with the re- sult that the teeth, Toothed surface spiral feed screw Feed spout Fruit of all ‘sizes and shapes tumbles down through an opening in contact with a motor-revolved screw ' several other insects that prey on the to- bacco beetle, and his destructive lar- vae, but it is none the less necessary Rapidly revolving | torthes drum - Extremes of heat, and cold will eradi- projecting from Peel receptacle both sides of the . screw flights, take hold of the material and turn it around against a drum which is rotating in the opposite direction. The drum is also provided with short teeth. The teeth of the screw and those of the drum, working in opposite directions on the fruit, grate the skins off. As the screw tends to turn the fruit around, it also pushes the fruit forward over the length of the drum. The peels are thus made to come off in spirals. The peel- ings fall into a trough at the bottom of the machine’ and the fruit pulps are dropped di " out on a chute at the side. ane Teeth on the revolving The peelings come off in spirals cate him, and fumi- gation with hydro- eyanic acid orcarbon bisulphide isalso very effective in compassing his destruction. © The process of manufacture. usually does away with both beetles and eggs, so that if protective measures are adopted their ravages can be more or less obviated. The smoker, therefore, has no well grounded reason to feel concerned regarding the possibility of finding the beetle in his cigar or cigarette. And the fact that the insect prefers expensive tobacco to the poorer grades may prove consoling to him who can afford only cheap *“‘smokes.”’ to control ‘him by’ artificial means.’ erro aa eee et Se A OCR EEA «ye 8 e nee See

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The canvas tire is less de- structive to concrete factory floors, linoleum runways, etc., and is practically noiseless This improved tire is made up of layers of canvas bound together, and may be fitted with a roller bearing as shown Canvas Wheels Reduce Noise and Save Floors E have steel tires, pneumatic tires and solid rubber tires, each with its place on some sort of vehicle, but the latest is a canvas tire designed for fac- tory trucks, hand trucks, electric indus- trial vehicles and other portable objects such as hospital beds, operating tables, oil and gasoline tanks and a score of other devices. Less resili- ent and less costly than rubber, the can- vas tire is far more resilient than iron or steel and of equal wearing qualities. The canvas tire finds its greatest field on vehicles which are either slow or which do not travel far. It is far less destruc- tive to concrete fac- tory floors, linoleum runways, etc., than metal tires and does not wear away con- crete and produce the fine dust which is so Popular Science Monthly TREADLE CONTROLLING HOOKS The work of Automobile tire repair- “ ing is made easy with this machine line. destructive in some forms of manufacture, The canvas tire is practically noiseless, which means greater comfort in cases of hospitals and the like and greater pro- duction in factories by the decrease of distracting noises. It is not affected by water, oil or grease and as a result is used on kitchen, laundry and packing-house equipment. Tire Repairing Made Easy with a New Spreader N accessory designed to makeeasier and lighter the work of repairing automobile tires has re- cently been put on the market. It consists essen- tially of two parts—a buffer plate and a working stand on which the tire cover is held. The buffer plate, which is convex, is applied to the outside of the cover at the place where it is desired to make the repair, and is held in place by a clamp. Thus the cover is pulled back and the operator is able to reach the canvas. The cover is then placed on the stand, as shown in our illustration, with the buffer plate next the stand. It is held in place by two claws that en- gage the beads of the cover and hold it firmly. The stand has four small rollers on its saddle which can be raised to ‘bear the weight of the cover, enabling it to be easily rotated for examination, or which can be retracted level with the saddle while the cover is being worked on. The ma- chine weighs about sixty pounds. The fabric can be cleaned with a buffer wheel in a very short time, instead of by the old laborious method of scrubbing with gaso- ra Se.” =wS]HW © OO Jas

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countries a scarcity of male workers in occupations which heretofore have been considered unsuitable for women. Thousands of the young men employed in the shops and factories, the offices, yards and round houses of the various railroad lines of the country have been drafted into the army or navy and many thousands more are sure to be drafted if the war should continue for a her: war has created in all belligerent School Trains Women for Railroad Service Some Wonderful Changes Wrought by the Draft long time. The railroads, being con- ducted upon a strict business basis, never employed more men than were absolutely necessary for maintaining the efficiency of the service. To prevent the service from being crippled, the vacancies must be filled with other efficient workers. Realizing that the supply of available men is greatly limited, some of the large railroads took steps to train women to take the places of the men drafted into military service. Since many branches of the railroad service, like the telegraphic and telephonic service, the block-signal operating, etc., demand a certain amount of previous training and experience, some of the large railroad companies estab- lished schools for the systematic training of young women for these branches of service. The students are taught teleg- raphy and in six to eight months most of them develop into skilful-and rapid send- ers and receivers of telegraphic messages. They are also instructed in the manner of controlling the block signal system by telegraph and telephone. The instruc- tion is along practical lines and is aided by models of railroad tracks with block signals, switches, trains, etc. ty Studying the movement of trains by means of realistic models. Below: Part of the room in which girls are preparing themselves to become railroad telegraphers and train operators 709

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{SEDI DOA | FRANCE] |ieGERM ; AUSTRO- 4 HUNGARY ob AUSTRALIA The diagram on the sugar-bowl represents the comparative total consumption of sugar of the eight countries mentioned WEETS are the true food for fighting men, as sugar is almost instantly converted into heat and energy. It is pure fuel for the human furnace and it burns without ashes. Mosso, the distinguished Italian physiological cheinist, through experiments in Naples many years ago, proved this with the ergograph, a contrivance which measures the fatigue that ensues when the hand is opened and shut, for example. He demon- strated that from three to five ounces of sugar eaten in the afternoon between the hours of five and seven- o’clock restored the vitality which lags always at that period of the day and practically started the human machine going with the same force which it had in the early morning. The German Army Fights with Sugar as Well as with Bullets Germans, always on the alert to utilize the discoveries of science, have, in effect, claimed the work of Mosso as their own and put it into practical application at their army maneuvers. Soldiers under special rations of sugar withstood the hardship of forced marches much better than did those who had none cr even a normal amount. With the declaration of war, the Our War Sugar Bowl Sugar is a quick-action food, and that is why armies must have it to restore energy 710 By John Walker Harrington amount of sugar consumed by each per- son in Germany rapidly increased, and the army got most of it. In the meantime, the vast beet fields of France and Belgium had been devastated, and the whole cane sugar trade which had been supplying Great Britain with such enormous quanti- ties was much disturbed. Of the 18,000,000 tons of sugar which the world produces a little more than half is cane and the balance beet. In making esti- » mates the sugar derived from the maple tree and other insignificant sources ig not considered. Australians Have the Sweetest Tooth of All Although the United States is out- stripped in both beet and cane growing by six nations, she leads in the world’s sugar marts. We consume nearly 4,000,000 tons a year and each person eats an annual allowance of 86 pounds, according to the returns for 1917. Although the American sugar barrel demands the most, the American sugar bowl, that is, the amount eaten by each person, is not so large as in some countries. The less sugar a nation produces, the more, rela- tively, it is likely to eat. The Australians have the most eager sweet tooth, for each one of them in twelve months con- sumes 106 pounds. Denmark, which is small in population, suddenly rose to a per capita consump- tion of 93.48 pounds a year in 1914-15, an excess which perhaps her Teuton neighbors can explain. The United Kingdom, that is England, Ireland and Wales, is credited in that period with an annual per capita consumption of 89.49 pounds, while for the same season every American was eating sugar at the rate of 84.40 pounds a year. The Germans had been having before 1914 forty pounds a year each. Owing largely to needs of the army and also to the fact that the Teuton countries which had been ex- ao hh, ee a eae ae ee ee lll

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| 36 pounds a year for each person. These figures do not, however, include the amount of Popular Science Monthly porting large quantities of sugar began to eat the surplus to make up for the deficiency of other foods, they soon reached a per capita consumption cf 74.95 pounds. All these orders for quick-action food brought in sight the bottoms of sugar bowls and barrels all over the world. Germany is getting a very scant ration of sugar at present. The government of France has decreed that twelve pounds a year is quite enough for each of her inhabitants, and similarly the United Kingdom family supply has been cut to sugar which confectioners and bakers and manufacturers work into their products. The which was slightly less than normal. in 1917 as compared with the 77 pounds of refined sugar assimilated the pre- vious year. America Is Not Saving Much Sugar Despite the cautions of the Food Administration, the consumption of sugar in the United States ‘i has not decreased very much, considering the fact that candies, desserts and various other edibles are being used more than su- gar in the concentrated forms. The exportation of condensed milk and canned fruits has also somewhat augmented the American use of sugar. Another fac- GERMANY UNITED STATES actual amount of sweetening which the French individual assimilated in 1917, judging from certain export figures, was probably 24 pounds, The best obtainable statistics indicate also that in the United Kingdom enough raw sugar was received to give every man, woman and child 62 pounds UNITED : : KINGDOM The recent investiga- AUSTRALIA tor in the six pounds per capita increase in consump- tion in 1917 f@ as com- == «=o pared with DENMARK 1916 has been the curtailing of the liquor traffic. Even before the war, sugar was having an increasing vogue as a substitute for alcohol. In some phases, the present sugar shortage ’ is‘a blessing in disguise. tions of Professors Sher- man and Swartz in the laboratories of Teachers College, Columbia Uni- versity, show that we are inclined to eat more free or uncombined sugar than we should. Four to five ounces a day, which is about our present consumption in all forms, is considered a_ healthful ration. It is best, to eat sugar in made dishes or conserves, so that it may be somewhat diluted and therefore more digestible. Much sugar can be provided for our fighters, if we eat more sweet fruits and vegetables, as well as of that alluring though often cloying honey, which satisfied a saccharine craving long before the Crusaders brought from the Orient the magic crystal of the succulent cane. In addition to honey we have as sweeteners maple syrup and corn syrup, which will both answer many purposes for which we now use sugar, and often quite as satisfactorily. - |

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712 The ‘‘Fulton Market’’ Hair Cut in Your Own Home AVE you ever heard of the “Fulton Market” hair cut? After the barber has trimmed your back hair as closely as he can with the shears, he strops his razor and proceeds to shave your neck, as if he suspected you of a desire to grow whisk- ers where they ought The re- sult is so pleasing to the eye of the New York ’longshoreman and the Western cow- puncher that the shaved neck has its vogue among those . who hold Fifth Avenue and its foppish ways in Even if you survive the loss of blood ‘caused by incidental gashes you may be tem- porarily or permanently disfigured. The artistic success also is questionable. . To supply the wants of neck-shavers, - Mr. William C. Bridges of Muscatine, not to be. contempt. ‘Ta., has invented a device to make shaving one’s own neck a_ harmless .. Operation. An ad- -justable band ’. which encircles the head is connected . by a curved and rigid finger exten- ' gion withthe guard ~ ‘proper. This pro- ‘tective part of the device consists of an adjustable ar- rangement of curved strips of metalorsomeother material, held to- gether by pins moving in slots. To give the guard a firmer support it is supplied at its ends with ear rests covered with rub- ber sheaths. Popular Science Monthly A Maker of Relief Maps Who Has Few Competitors HERE are only a few men in this country who devote their time to the making of relief maps. One of the most Burgie, a French Swiss, who learned the art from his father, Pro- fessor Joseph Burgie, for- merly a famous European maker of relief maps. More than forty years ago, Prof, Burgie, accompanied by his son, Fred, went to Palestine survey of the Holy Land. He _ gathered valuable data concern- ing many points of im- portance in history and tradition and used them after his return, when he made a relief map of " Palestine. Fred Burgie followed in his father’s footsteps and became the most renowned maker of relief maps in the United States, In his little shop in Rochester, N. Y.,, he has made a large map of Palestine, now at Crystal Pal- ace, London, and a smaller replica of that map for the National Museum in Washington. No danger in shaving your neck with this well-contrived device Photograph of a section of the Pal- estine relief map modeled by Mr. Burgie, for Crystal Palace, London Fred Burgie, at work on a map at his shop in Rochester, N. Y., He is an expert in this work noted makers of such maps is Fred: and made a careful © ee ee

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eee Science M sieinal Bacteria Cannot Live in the Light F we cover with black paper one-half of a petri dish (a small circular glass tray with cover) in which bacteria are growing and then place the dish in a light warm place for a few days, the growth of bac- teria in the light part of the dish will be found to be checked, while growth con- tinues in the covered part. It is a matter of common knowl- edge that disease germs thrive where dirt and darkness exist and are killed by any long exposure to sunlighs. Accord- ing to George W. Hunter’s “Civic Biology” (American Book Company) this shows us the need of light in our homes, especially in our bedrooms. Underfeed Pipe That Loads from . the Bottom HE accumulation of moisture laden tobacco in the bottom of the bowl of the pipe is unknown in a style that is fed from the bottom. When more tobacco is to be put into the pipe, the bottom is © Western Newpaper Union This living emblem of the Marine Corps is formed of its bearers in their parade ground at Paris Island, S. C. Two Thousand United States Marines Form Their Emblem WO thousand marines, quartered at the training station of the U. S. Marine Corps, at Paris Island, S. C., are shown in the accompanying picture grouped in such a way as to form the removed, the new tobacco inserted from ® design of the service emblem of the Ma- below, and the bottom replaced; conse- quently no part remains for days to soak up moisture and juices. The removal of the bottom also facilitates the cleaning of the pipe. Whether or not one would appreciate the aroma of tobacco that would permeate his clothes as a result of carrying around the dottle in his pipe between smokes, is another matter. Those who usually accumulate a lot of moisture in their pipes when smoking will find this new fan- gléd pipe a great boon. ' uot A DAMPNESS CAUSES TOBACCO 1 (OP OF PIPE Gos} 4 30 BURN AWAY FROM VENT 4 { NFR TORACED 1 THE BOTTOM TO PROTECT IT FROM THE FIRE AND KEEP @ CLEAN BOTTOM REMOVABLE FOR LOADING Section and method of luad- ing the bottom-filling pipe rine Corps, a globe showing the western hemisphere, an American eagle perched on top and.an anchor crossing it. It is. well to remember the fact, that in.the emblem North and South America are visible on. the surface of the globe. Otherwise it would be rather difficult correctly to interpret the meaning of the dark spot within the circle representing the globe. The novel grouping of masses for pictorial effect is not an easy matter and it must have required a great deal of patience to obtain the strikingly good effect shown by the photograph, which was taken on the pa- rade grounds of the training station.

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What a $50 Liberty Bond Will Buy The War Department spends $4,875,000 a month to turn out rifles of the type which this soldier is holding ready for the attack CORD } $.08 Here’s another use for Liberty Bond money.’ Gas masks, like that shown in this photograph, cost $339,000 for the men of one di- vision of infantry. But that’s only one item of one nation. Almost a dozen cities larger than New York could be bought with the money spent on the war by the vari- ous governments Look at these arti- cles of wearing ap- parel and then read this: The expense of clothing a mil- lion and a_ half American troops totalled $62,265,000. If this information startles you, bear in mind that at one , ic: period Germany ' THREE BLANKA $18.75 was paying out “ $700,000,000 monthly, in various ways, for the war

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What a $50 Liberty Bond Will Buy vit Cees setts a * a a a] ‘eTTy Steel helmets can be supplied to one division for $84,000. Helmets of the type pictured here will save the American troops from death or wounds. The rifle recalls the words of General Percin of France, who said, basing his statement on the cost of the war to his country up to January 31, 1917, that it cost $32,000 to kill a man To equip three brigades with the kind of shoes worn by this defender of the nation means an outlay of $285,600. The cost of each pair is $5.10 and it takes nine pairs a year per American soldier abroad, allowing for consumption and proper reserve supplies. So less than a $50 Lib- erty bond will keep a man shod for twelve months

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Giant Cars to Help in Solving the Coal Problem NE of the reasons given for the coal shortage dur- ing the past winter wasthelack of transportation facilities. The coal-carrying railroads of the country have tried for some time to solve this serious problem by substi- tuting larger cars for the old style coal cars of limited capacity. One of the south- ern railroads is now trying out several gigantic coal cars, which hold the record as the largest of their kind in the world. The average coal car in use on the differ- ent railroad lines has a capacity of sixty tons, while the new cars, one of which is shown in the illustration, has a capacity of 120 tons. The new cars, which differ materially in their construc- . tion from the old style cars, are only fifty feet long, that is fifteen feet longer than the average coal car of steel construction. The greater capacity has been attained by increasing the length of the car and also its depth. The center sill running lengthwise through the car acts only as the medium for transmitting the pulling and buffing stresses, while the side framework resting upon the trucks carries the load. To obtain a better distribu- tion of the weight, six-wheel trucks are used in- stead of the usual re 25h ee four-wheel trucks. 120 TONS 50 FT. LONG Popular Science Monthly If You Own a Walnut Tree These Days You’re in Luck ALNUT, walnut, walnut. That is what your Uncle Sam is looking for just at present. What does he want it for? Why gunstocks. Walnut is and always has been the wood par excellence for the manufacture of stocks. It is easy to work, will not easily crack, and will not splinter. In spite of the enormous demand which has always existed, and exists now more than ever, there is any amount of the wood to be got, so long as you are willing to pay the price. The reason for! this is that in the timber countries, ag they have become more and more settled, the inhabitants have sought to beautify their land and homes, and consequently, lacking the urging of necessity, have abso- lutely refused to sell their trees at any price. Now, under the spirit of patriot- ism, people are sacrificing these grand old landmarks to the service of their country, and consequently the Government is getting all the walnut it needs. : The boys are getting first- class stuff too. Uncle Sam lays down standards and when he’s laid them down he sticks to them like glue. The conse- quence is that in this case the stocks are all cut from good wood, properly selected and seasoned, and with the grain running the proper way to guaranteetherequisitestrength. The next best wood for gun stocks is oak. Oak, however, does not yield so readily to the turning of the lathe. Furthermore, walnut will not crack so readily as oak. Other* woods are not desirable. SFT. SQUARE [= ad PEC 60 TONS 35 FT LONG This new car is only fifteen feet longer than the average coal-car but has a capacity of one hundred and twenty tons. It should help solve the serious transportation problem eo Fe wet Oh et ht Le Q hast CO aoht ot > be - -_. mtr tro ttt an atk afk hee CU;

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Carelessness and What It Means in Forest Fires URING the year 1917 our National forests were devastated by 7,814 forest fires. According to the report of the Forest Service of the Department of Agriculture all these destructive fires, with the exception of 2,132, which were caused by lightning, could have been pre- vented; 952 were undoubtedly incendiary fires, while the rest were due to pure carelessness of campers, hunters, rail- roads, settlers or travelers. Applying the Fireless Cooker Principle to the Delivery Wagon VERYONE, nowadays, knows the principle of the fireless cooker. Interpose a sufficient layer of insulating material between the atmosphere and the food which is to be kept hot and you reduce the amount of heat radiated. The principle is also applied in keeping chilled food cold. The insulating ma- terial used is mixed wool, asbestos, or even hay. The same principle has now been suc- cessfully applied to delivery trucks and packing boxes. One of the large express companies has been making experiments this winter in St. Paul, where the tempera- ture was way below zero. Cut flowers, and other very delicate goods, were loaded directly from trains into these cold-proof boxes, and preserved until they could be delivered, in spite of the severe cold. Motor-trucks and wagons were also successfully equipped in this manner, in- sulated with paper, canvas and felt. These delivery wagons are made on the fireless cooker principle, with non-conducting walls, bottoms and roofs Popular Science M onthly This‘ model “ patient” is for the training of dental students at Iowa Dental Practice on Teeth That Never Ache EFORE dental students are per- mitted to practice upon patients in the clinic they must undergo a thorough training in the science and technique of dentistry at their college. In order to give a dental student the experience of working upon a model closely resembling human jaws and undér conditions such as would confront him in his work at the clinic, Dr. F. H. Volland of Iowa City, Ia., has invented the device shown in the at-° companying illustration. The model jaws, with bone teeth im- bedded in the gums, are fastened to an adjustable arm supported by a_ pedestal. These jaws may be placed in any position which the jaws of a patient in the dental chair might possibly assume. Not until the student has learned the technique of fill- ing teeth, capping or crown- ing them and doing bridge work on this model will he be permitted to try his skill upon the patients in the clinic. The University of Iowa uses the model with success.

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Conveniences and Novel- ties in Office Equipment

A new and dis- tinctive article for the desk of the office man is the plate glass tray, the parts of which are held together with nickeled clamps An inkwell that tilts forward and AIWWv eo Acombined add- ing and record- ing machine with movable carriage and rack attached to indicate the position of the carriage

An attached clip enables the

has an automat- ic closing device that prevents the fluid from evaporating Ldddddldddddldea

POV MM UMA Anelectrically heat- ed device that drops wax and seals pack- ages at a much more rapid rate than by methods formerly employed

=| pencil to be easily carried 4 \.. andthe cap &m; bodies a service? rf ce

able sharpener

cn. Ds. DOW WW DW SE s A railroad office has this re- PA ™ volving table installed in one of —& its offices to speed up the sorting The hand-operated envelope sealer shown below will seal fifty envelopes per minute

Aknock-down chair that is fastened to- gether by means of metal bolts and _ clips at the joints

718

ES —< . =— -

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Do It with Tools and Machines and Save Time and Muscle , At the left, a two-part heat-treated steel shell shaped like a truncated cone for dressing valves A small electrically-driv- en bench planer is at the right. It is adapted to home or workshop use A boltless flange union Increasing or diminishing the di- A grease cup using grease put for pipe .lines, which ameter of the pulley over which a up in paper capsules. A clean draws the parts to- flat belt runs by moving the vanes way to fill the cup gether by rotation in or out to change speed of the shaft i : Lock q Below is shown.a novel machine de- Pilibie signed by a farmer to pile stumps for burning in land-clearing operations A portable chain grip vise which can be fastened quickly to any kind of horizon- tal or vertical support. It can be used in various ways A ball bearing lathe center de- signed especially for lathe used by metal spinners or wood turners

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© Int. Film Serv. This mass of debris is the result of a huge chimney crashing through factory roof Chimney Crashes Through Three Floors of a Factory towering above the of a box factory at Lynn, Mass., suddenly fell and crashed through three floors of the building, killing three of the employees and injur- ing others. Several persons were carried down with the fall- ing brick and timber to the floors below. Others sitting quietly at work suddenly saw a great hole open be- fore their eyes, into which their compan- ions and machines van- ished. There were many narrow escapes from injury and death, and amid the excite- ment women had to roof Popular Science Monthly EAKENED by a terrific gale, a three by four-foot brick chimney Jersey Air expelled through this shoe ven- tilator blows out lighted match be restrained from jumping from windows, Firemen, police and physicians came promptly to the scene and did heroic work. It was fortunate that no fire oe- cured, since the stiff gale from the harbor would have spread the flames rapidly, One of the suggestions resulting from the catastrophe is that there should be physicians’ call sounded through the fire-alarm system in an emergency of this character. A pre-arranged signal, it is thought, would bring a corps of doctors quickly to the scene and hasten the rescue and relief work. This is really a most serious question Everybody has read of the dreadful holo. causts that happen every now and then in different parts of the country. How often it goes like this: ‘‘Several physicians were soon on the spot and worked hero- ically at their work of mercy until far into the night. It was pitiful to hear the groans of the injured who could not be aided immediately owing to the few doctors who were available to carry on the work.” Are You Stifling Your Feet? Let Them Breathe UPPLY air to the feet and foot ills would vanish is the belief of a New manufacturing company. To prove its point it has introduced a little device to ventilate your shoes. The device was invented by Mr. E. J. Devlin of New- ark, and consists of a little perforated button which is made so that it will clip into a hole in the instep of the shoe like an eyelet. Into this screws a plug with a_ hole through the middle. By adjusting the plug a greater or less quan- tity of air can be admitted, but at the same time water and dust are excluded. Air is drawn in and expelled at every step. The ex- terior portions of the device are colored to match the shoe.

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Highways and Automo- biles in Warfare N discussing the impor- tance of good highways and of automobiles in mod- ern warfare, Major Amos A. Fries, Corps of Engineers, U. S. Army, brought out some interesting facts. Bas- ing his statements upon the experiences of the French military authorities, he ex- presses the belief that in case of an emergency it would be possible within a few days to get together 200,000 auto- mobiles, which would be able to carry 600,000 to 800,000 men with their equipment and rations to any desired place. Locking Gear Lever in Neutral Position to Prevent Theft NE of the latest of the locking de- vices which is to be attached to an automobile, which will prevent the car from being run under its own power but which will not prevent its being stolen by the towing method, con- sists of a small lever- type lock inserted in the ball-ended handle of the gear-shifting lev- er. A key inserted in the lock operates a small rod extending down through the hol- low lever to the base. The turning of the key in the lock trips a small lug on the upper end of the rod so as to rotate the rod slightly and cause a similar lug on the bottom to slip into a notch and lock the gear-changing mechan- ism in a neutral posi- tion. As we said above, this does not prevent a car from being towed away by a thief. Popular Science Monthly ‘ot © By C. Trampus Not particularly comfortable for the patient, but it will at least take him to the hospital with very desirable speed teen Gear-shift lever locked in neu- tral, preventing car being stolen A Queer Improvised Ambulance In Use in France N addition to the large number of regular ambulances, constructed for that purpose, which are in use behind the West Front in Flanders, there are many that were im- provised with more or less success from vehi- cles of every kind. The accompanying picture shows one of these am- bulances, improvised from an automobile of the coupé style. The bed intended to receive the patient is placed immediately be- hind the cab of the coupé and rests upon ‘ the box containing the gasoline tank. A trip in this ambulance is probably rather hard on the patient, but in emergency cases the conveyance may do ex- cellent service, especial- ly if the roads ere not in too bad a condition. At any rate, men suffer- ing from wounded limbs could be transported.

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Wind, Weather and the Airman The Invisible Perils of the Whirlpools, Gusts, and Eddies of the Ocean in which Men Fly IR navigation, in its relation to A weather, is repeating the history of marine navigation. The slow sailing-ships of early days were the sport of wind and waves; the great ocean liner of today pursues the even tenor of its way regardless of the elements. Under the urge of necessity the military aviator now flies in all kinds of weather, and his high- . powered machine negotiates atmospheric difficulties that would have been insupera- practical experience of aeronauts on the one hand, and the scientific investigations of meteorologists on the other. The mariner dreads a strong wind; the aero- naut an unsteady one. Mere strength of wind is harmless to the aviator, except in starting and -landing, and, indirectly, owing to its ability to drive the airnlane far out of its intended course. Ii the strongest hurricane that ever blew were perfectly steady, the airman might well ble a few years ago. Nevertheless, even the biggest ocean lin- ers sometimes come to grief, and the day is still distant when the aviator will not need to keep his weather-eye wide open. Airships and air- planes are the sub- marines of the at- mosphere, but the element in which they ply is far more fickle than the ocean. f The cur- rents of the latter are comparatively feeble and regular; those of the former are often immense- ly powerful and capricious. There Are Winds and Winds An aviator study- ing the atmosphere learns much of inter- est. The structure of the atmosphere with respect to wind is a subject concerning which a great fund of knowledge has re- cently been acquir- ed through the Flow of Air Over a Ridge Notice that the crest of the air wave lies a little beyond the crest of the ridge. This does not apply to isolated hills, which the air easily passes around Flow of Air Over Two Ridges Notice the eddy in the valley to the leeward of the first rfdge. In this case the crest of the air wave still lies beyond the crest of the ridge, as seen above seal WIND > er era eee EN ag NP lt ye prey conan A “Sheltered’”’ Landing-Place May Be Dangerous A landing-place surrounded by trees is dangerous in windy weather on account of the air waves between the moving air above and the calm air below Waves and Gusts in the Air The illustration shows how these are made visible by smoke. The reader will be able to observe this phenomenon for himself almost any windy day 722 be as indifferent to its speed as the average mortal is to . the speed with which our terrestri- al globe rotates on its axis. But un- fortunately the wind is hardly ever steady, either in force or direction. It is full of gusts and eddies, up-cur- rents and down- currents, and it is these eccentricities which gradually de- velop in the aviator a sort of sixth sense, a “‘feel’’ for atmos- pheric fluctuations, that enables him to adjust his machine instinctively to the forces tending to disturb its equi- librium. He also learns by experi- ence the conditions under which irregu- larities of a pro- nounced character may be expected. He becomes well acquainted with the great mound of air that drives the air- plane upward in passing over a hill or mountain; with

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the eddy that lurks in the lee of such an obstacle; with the downward tendency of the air over lakes, rivers, swamps and forests. ‘‘The air is so sensitive,” said Mr. Gustav Hamel, the famous flyer, “that it is affected even by the color of large patches of vegetation. Whether this be entirely due to the different heat- radiating power of differ- ent colors, it is impossible, antern 2 uw Se %\ to say, but invariably an aeroplane on passing from grass land to a field cov- ered with yellow flowers experiences a certain amount of air dis- turbance only less noticeable than the inevitable bump ex- perienced in passing from green fields to ploughed land or from ploughed land to meadow.” When the wind is blowing, the air for at least a few hun- dred feet above the ground is nearly al- ways in a state of turmoil. This is partly due to friction of the moving fluid against the irregular surface of the earth, and partly to the ascending and descending currents caused by differences in temperature. The latter effect is illustrated in the rapid rise of air over a bare plain, by day, and its fall over an adjacent forest or body of water. Popular Science Monthly LANTERN—® O<

A Solution of the Fog Problem Along the main flying routes landing-grounds will be established at intervals of ten miles. tion will be marked by illuminated kite-balloons

723 erate wind blowing, forming smoke-waves. The Autograph of a Gust These disturbances give rise to the very marked fluctuations in the force of the wind known as gusts. There are cer- tain forms of anemometer especially designed to record the gustiness of the wind. A record of its force is traced by a pen on a moving strip of paper, and the “anemogram”’ thus obtained shows a continuous series of irregularities, the extent of which increases with the strength of the wind. The puffs and lulls often alternate at intervals of a few seconds or less, and ‘ the actual strength of the wind at a given instant may be many times greater than its average force for, say, five minutes. The turbulence of the lower air extends to various heights, depending upon the strength of the winds A rough rule, evolyed by Zeppelin pilots before the war, was to expect turbulent conditions up to an altitude equal to from 10 to 20 times the force of the wind in meters per second. Thus, for a wind of 10 meters per second, the turbulent layer would be from 100 to 200 meters deep, and so on accordingly. With increased altitude the wind gen- Their loca-

A good pic-— erally in- ture of the |' creases in atmospheric both strength ups-and- and steadi- downs and ness, but other dis- sometimes turbances en- countered by the airman when flying low is fur- nished by the behavior of the smoke

very un- steady air is encountered even at great heights. This brings us to the impor-

from a fac- tory chimney with a mod- Clouds Seen from Above Aeronauts, looking down on the wind-swept surface of the clouds or have observed their surfaces to be thrown into a series of rolls of vapor, which are vast waves of air with crests half a mile apart tant subject of air-layers, broad streams of air

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Popular Science Monthly Air Waves Far Above the Earth With the right conditions of temperature and humidity these waves are made visible by the formation of little = clouds whose crests are marked as furrows. These are called cirrus, and are the light, fleecy summer clouds of different temperatures and humidities, which glide over each other without much intermingling. At the boundary surface between them, friction sets up waves like those produced in water by wind flowing ever it. When -the two streams are moving in the same direction the waves are long and regular; when they are more or less crossed, the waves are short and choppy. The moisture at the crests or furrows of these waves may be cooled to such an extent. as to condense into visible clouds, arranged in long continuous rolls or successive rows of detached patches; but more often the waves are entirely invisible. Ascending and descending currents in the air are also sometimes made visible by the larger detached clouds of the type known as cumulus. Each of these clouds marks the summit of an ascending column of moist air, while in the spaces between them the air is generally sinking. The up- flowing air under a cumulus cloud may at- tain a vertical speed of 25 or 30 feet a second, while the descending current be- tween clouds is sometimes so strong that an airplane cannot force its way up through it. The most violent vertical movements are encountered in thunder- storms. The term “hole in the air” de- scribes a sudden downward tendency of the airplane, whether due to running into a descending current or to encountering a sudden change in wind velocity and conse- quent lifting force. There has been much talk about “charting” the winds for the aviator—a project implying the assumption that the currents in the atmosphere are as regular and as constant in their location as those. of the ocean, which is far from being the case. Even the most constant winds in the world—the trade winds—are subject to great fluctuations in force. What the aviator really needs to know is the typical behavior of the winds with respect to the distribution of barometric pressure at a given time (as shown on a daily weather map), and how they are likely to be af- fected by the topography of the country over which he is flying. ~- Fog—the Airman’s Dread One of the most serious weather prob- lems of the aviator is presented by fog. When flying above a fog (and the same is true of low-lying clouds) the airman has no landmarks to guide him. His compass is almost useless, because, while it tells him which way the head of his machine is pointed, he has no means of knowing how much he is being drifted out of his course by the wind. Ina long flight his “‘leeway” may carry him scores or hundreds of miles wide of his objective point. Fog also pre- sents a grave danger when he is landing, as he knows neither his distance from the

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Popular Science Monthly

725

N2 45 Pressure-Tyubse Anemogram From......- a day

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Observatory lade dee

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e338 3 y in Miles per hou: i Velocit $

MION 6 rs 24.3 20.2 14.7 =~ S's” 6 »n ~~ @ Ww 6 Pressure tn Pounds per Square foot ° u The Wind’s Autograph on a Gusty Day Recorded with a pressure-tube anemometer. ground nor the character of the latter. Many a forced landing in foggy weather has ended disastrously in the ocean. ’ The fog problem will undoubtedly be solved. Probably the radio-compass or some other system of wireless signalling will help the airman keep his bearings, and he will obtain further guidance from aerial buoys, in the shape of captive balloons, floating above the level of all ordinary fogs. Mr. Holt Thomas, in England, has recently proposed the plan of establishing landing grounds at inter- vals of a few miles along the main air routes, their location to be marked with kite-balloons by day and powerful search- lights by night. A better plan would be to fly at each landing place, and wherever else aerial signposts were desired, a string of kite-balloons flying tandem, with a lantern suspended from each balloon. It would thus be possible to attain much greater altitudes than with a single balloon and a searchlight, and hence to provide for fogs of all depths. Little need be said. about the other weather factors in aviation, because they are hardly more serious in their effects than the corresponding conditions of travel on terra firma. At great altitudes the air is very cold, in summer as well as winter. The carbureter must be shielded against freezing, and the aviator needs the warmest clothing. The airman also needs protection against rain and. hail—the The vertical lines are hour-lines and the horizontal lines show the force of the wind in miles an hour and also in pounds a square foot Direction is also indicated pelting of which, when one is flying at one hundred miles an hour or more, is un- comfortable, to say the least. Lightning, which is a serious hazard in ballooning, seems to be relatively harmless to the air- man. Deposits of ice and snow, besides loading the planes, may hamper the work- ing gear of the machine, though aviators have reported few cases of this kind. Last, but not least, in the coming age of commercial aviation the weather bureau now maintained by the governments of all civilized countries will enlarge the scope of their activities so. as to safeguard air traffic against atmospheric dangers; while the science of weather will, in turn, derive great benefit from the collective wisdom of practical airmen. A Thousand Dentists Will Be in the United States Army ENTISTS are just beginning to come into their own in the Army. Even yet their importance is insufficiently recognized. According to the latest re- ports we are to have only one dentist to every thousand men. Yet there are to be eight horseshoers to every hundred horses. For the two hundred and fifty thousand horses which the government will need, there will twenty thousand horseshoers, while for one million men there will be provided only a thousand dentists.

Maybe you have special needs. scope of the magazine.

Write to the editor about anything within the He will be glad to help you.

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Popular Science Monthly -— When Is a Feather Not a | Feather? When It’s a Hair UR picture shows several midground types of feath- ers in course of evolution. They are midway between scales and feathers. Crossing in the center are two hairlike forms called ‘“‘filo- plumes.” Sloping up to the right is one found in abundance on poultry. It is practically a true hair with its tip divided into several slender prongs, some of which have a suggestion of © Underwood and Underwood Ringing the bells of St. Paul’s Cathedral, in London, in honor of the great Allied victory at Cambrai Ringing Out the Victory of Cambrai fromthe Great Bells of St. Paul’s N& every one can ring the great bells in church towers. It takes skill and it takes strength. In the accom- panying illustration we see the bell ringers of St. Paul’s, London, preparing to ring joy bells in honor of the successful Cambrai offensive. The upward swing of the bells is so strong that the ringers are very often pulled off their feet. On the rebound, each man lands on a small, flat cushion in front of him, by which his fall is broken. The small loops to be seen on the boxes are foot braces. According to an old English custom, no bell ringer may wear a hat while at his work. Judging by the expressions on the faces of the men here pho- tographed, they would uncover without any aid from precedent, for they are bring- ing to the occasion a deep solemnity, conscious of the cost of victory. Campanology is one of the most interesting and most intricate arts practised. Change-ring- Wen. ing’ is exceedingly diffi- cult and very exhausting. Various peculiar types of feathers in the process of becoming scales feather-down near their bases, The one crossing it, noticeably more plumose, is from an owl. The form to the right with the many pointed black tip is from one of the very rare toucans. It is from midway on the neck and shows an intermediate stage - between the true feathers on the back and the scalelike forms topping the head where the feathers have changed wholly into thin, horny plates or scales, seen at top of picture. Barely enough feather- down remains to suggest its origin. To the left side of the picture is a unique intermediate stage between feather and scale—strongly suggesting a fish scale. This would be the normal trend of evolution owing to the aquatic life of the penguin from whose wing this was taken. So nearly midway between scale and feather, it claims both names and is called squamipennis —scale-feather. The throat of the humming bird supplies the form at bottom. These are true feathers and take their name not from any mimetic form of structure, but from their col- lective app--arance which is strikingly scalelike. They are called squama. It is such transitory stages as this, observed repeatedly, that lend color to the evolution theory.—C. B. DAvIs.

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Cooking Your Meals While You Using the exhaust heat of your engine to prepare luncheon while running at twenty-five miles an hour By Albert Marple HE manifold stove is new. It fits beneath the hood over the ex- haust manifold of the automobile engine and may be used for baking pota- toes, heating canned goods, and water. The device costs only about a dollar to manufacture, uses heat that would other- wise be wasted and is a valuable time saver. It was invented by J. I. Wernette, of Glendale, California. This stove is about imeem ten inches square at the top and is fourteen inches deep. A hole cut in its side permits it to ASBESTOS COVER etc., from touching the pipe. For bak- ing potatoes, a baking pan, sufficiently large to fit tightly within the stove, has been provided. When warming up canned goods the cans are placed directly upon the wire netting. An especially prepared can permits the motorist to make coffee or boil water for tea. Another type.of stove, heated by the exhaust, is located on the runningboard. This new stove is a large steel box, around the inside of which is a heating space, about one RUNNING fit snugly over the mani- fold, and a wire netting is so arranged as to keep the pans, canned goods, Showing stove under hood with all the ne- cessary connections to main exhaust pipe. This stove is ingenious and gives excellent results This is the footboard stove. The _ illustra- tion shows the food being placed in the cooker and the valve that controls the heat (SMP AAPA AAD Diagram showing construction of above and disposition of the food inch wide at the two sides, ends and the bot- tom. To provide the space a sheet-iron box is soldered in place within the steel box, the iron box being one inch smaller all around than the steel stove. The pipe which carries the exhaust gases to and through the stove is attached to the main exhaust pipe. A hole is made in the pipe and the end of the cooker pipe clamped over it. There is a valve between the exhaust pipe and the cooker so that the latter can be disconnected or used at full capacity. The gases escape eventually through an. auxiliary exhaust pipe. Re- movable wire shelves are placed within the stove whenever it is desired to cook potatoes or apples. So efficient is this cooker that a large fish, a rabbit or quail may be cooked to a turn while the car is traveling a distance of fifty miles. Potatoes or apples may be baked in a distance of from fifteen to twenty miles. This box or stove is two feet long, ten inches wide and twelve inches deep. An asbestos pad arranged within the lid retains the heat.

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Letting Gasoline Do It Attachments to a tractor for handling a road shovel; operated by a single person Cleaning the carbon from several material for removing the carbon is Latticed shoe cleaner set into the automobile run- ning board helps to keep the interior of the car in condition Accelerator foot-rest that positions, making it comfort- how tall or short he may be Shock absorber within a drum, attached to the frame of a car The throttle valve has an electric coil embedded in it for heating the gas to make starting easy Engine piston of aluminum alloy, in skeleton form to make it light 728 M in G ¢ I c

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Letting Gasoline Do It ny | 4 A tractor need not be purchased only for summer work; it may be used in winter to harvest the ice as well In keeping with the times this. minia- ture airplane at the left, bearing the United States insignia, makes a neat automobile radiator ornament automobile engines at one time. The contained in the large tank on the right ; How the air currents toaradiator may be controlled by the use of acurtain operated from the driver’s seat, is shown below has adjustments for many able for any driver no matter or how large his foot is Sharp spurs attached to an automo- bile chain to give greater Metal ruler graduated inches s grip on road ; Rubber pivot held to n glass by suction ‘le an vil it Glass , the euttingedge ke Rubber base standard with revolving arm and sy cutter for making automobile headlight glasses

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Popular Science Monthly = & % a 5 “Acting” the old Colonial days. children learning history in a new and interesting way ‘‘Making Believe’ You’re Miles Stand- ish to Learn American History N the State Normal School, situated in Salem, Massachusetts, a new method has been adopted to teach kindergarten children through pictures. Whitney, the art teacher in the school, conceived the idea of using drawings in colored chalk upon the blackboard to il- lustrate and make clearer the stories read to the children. When he talked about the Colonial times Mr. Whitney greatly aided the in- terest and under- standing of the chil- dren by improvising for them Colonial cos- tumes made of cam- bric, pasteboard and paper. To illustrate the life of the Indians a forest scene was drawn upon the black- board, while the chil- dren, dressed in In- dian costume, were seated around the imaginary campfire. Massachusetts school Frederick W. How Many Cubic Feet in a Ton of Coal? ERE is a little informa. tion which will help you to solve the vexing problem that is apt to bea hardy annual, i. e., how much coal to order in order to fil} the bunkers, but without having to put some in an old barrel in the outhouse. A ton of egg coal contains from thirty-two to thirty-eight cubic feet, averaging about thirty-five. By measuring the cubical contents of your bin you will be able to esti- mate how much to order to fill them. This may be done by multiplying together the length, breadth and depth of - your bin. In Trying On That New Hat You May © Get Something Besides the Hat HE doctor, who sees bacteria every- where—even though they are in- visible—warns you now against trying on hats in a hat-store. Most men try on three or four hats be- fore they get what they want, and it was discovered, by actual observation, that two per cent of them have noticeable eruptions on their faces and foreheads. As a measure of protection thin paper skull caps are recom- mended by Dr. Wal- lace A. Mannheimer. The caps are to be worn while trying on new hats. Unfortunately, so far, it is only the bet- ter hatters that have introduced this pro- tective measure, but ; it is to be hoped that the public will soon y, demand a skull cap as This paper skull cap may mean all the a matter of course, like difference between sickness and health an individual. cup.

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on Grading Machine Does Work of 125 Men It digs to grade and loads six hundred wagon loads in a day This machine reduces road grading and the construction of good roads to an economical and scientific basis. It does the work of a large road-gang OT so long ago a huge machine made its appearance on a Milwau- kee street which had to be graded. The machine had creeper feet in front that reminded one of the tread of a tank on the Western Front, and in the rear a roller. There was a huge wheel on its front which tore up the dirt precisely to the depth wanted—no more and no less—with the relentlessness that never could be equalled by hand shovels. If you want to know more about the Turbine Street and Highway Grader, look at the accompanying picture. The dig- ging is done by a rotating cylinder on which. are mounted twelve buckets. Rooters on the cutting edge of the buckets lift up the dirt and tumble it back into the buckets. As the cylinder turns, the dirt is dumped on a belt-conveyor, which extends at right angles from the side of the grader and drops the material into a waiting wagon, truck or car. Almost everything about the machine is adjustable to suit the conditions en- countered. Thus the conveyor can be ad- justed to load on either side of the grader. The cutting cylinder or wheel can be ad- justed vertically to make it cut from one inch to two feet deep. Cuts are five feet, seven inches wide. While the digging wheel is in action, the entire machine moves forward at any of three speeds ac- cording to depth of cut and character of material which is being excavated. The creeper tread on which the front part of the grader is supported does away with planking and prevents settling. But if settling should occur, it is easily enough detected by sighting along the grade sticks and corrected by elevating the cut- ting cylinder or turbine. The two sets of creeper treads have separate controls which makes it possible to make short turns when necessary. When it is realized that the utmost capacity of hand-shovel labor is five wagons a day and that the Turbine Grader can easily load six hundred wagons and even more a day, the possibilities of the machine become apparent. It does the work of 125 men at a great saving of cost. 731 =

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732 Popular Science Monthly A New Can for Handling Gasoline to Prevent Waste UCH gasoline is wasted every year Yi. by evaporation and spilling. Nowa Chicago firm has introduced a new can designed to prevent this waste. It is fitted with a hinged spout cover, closed by a spring. This . seals the spout the Tipping handle moment the pres- Air tube to sure of the thumb make steady on the lever is re-_ flow leased, thus pre- venting evaporation and also loss by splashing out or spilling. A steady stream is assured when pouring by a long pipe that extends to the bottom of the can, thus admitting air in a steady, constant stream, instead of forcing it to bubble through the stream of gasoline as it leaves the can. This does away with all the objection- able splashing when pouring out the contents of the can. If all the automobile owners in the United States saved one gallon a year each they would create an additional supply of 4,500,000 gallons. This is enough to keep 1,250 airplanes in fuel for a whole year. It is the team-work that will count in this as in all else. It is the “long pull, the strong pull, and all pull together.” Carrying handle It Walks Through the Field, ang Drags a Plow HE tractor here shown is a small, inexpensive one that can be used very profitably on farms of less than one. hundred acres. The little mechanical worker is only four feet high and three and a half feet wide, but it wil] plow four acres a day witha fuel consumption of less than two gallons an acre, The tractor is the invep- tion of Rush Hamilton, a California orchardist, who sought in vain for a machine to do his work. It may be called a walking tractor in comparison with the creep- er or round-wheel types, Note the radial tread legs on the wheels. They pene- trate to the sub-soil for traction. In plowing, one wheel of the tractor follows in the furrow, thus eliminating the side-draft on both tractor and plow or other imple- Safety gasoline can de- ment. The machine is so signed to prevent waste small that it can pass under the branches of trees where even a horse could not go, much less one of the cumbersome juggernauts which most tractors resemble. It also takes up very little room to store when not in use, and is simple enough to be easily repaired by an amateur mechanic. This little tractor is only four feet high and three and a half wide, but it will do the work of four horses. It was invented by a Californian fruit rancher for his own use

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‘almost exclusively by the off. At the point where How Would You Like To Be in the Place of the Man in This Picture? HE spiderlike silhouette near the apex of the angle formed by the falling top and the majestic trunk of the magnificent Douglas fir in the center of the picture is that of a man, the logging foreman of a lumber company on Puget Sound. These giant firs are greatly needed for the keels, frames and other parts of the big wooden ships now building for the Gov- ernment and are supplied forests of Washington and Oregon states. The big tree in the picture was one hundred and eighty feet high before its top was cut the cut was made the trunk had a diameter of twenty-two inches. The fore- man climbed the tree with telephone-linemen’s spikes and fastened him- self to the trunk with a lineman’s belt. It took him twenty minutes to cut the top. Here Are Some War Breads You Have Never Known WING to the shortage of wheat the powers that be have been experi- menting to see whether satisfactory bread cannot be made from other cereals. They have come to the conclusion that they can— very much so. The chief grains which the researches have added to our food-stuffs are cottonseed meal, kafir corn, feterita, grain sorghums, and milo. So far all these have been used to feed to stock, but it is found that they can all be milled and made into bread. Not only that, but the bread is more palatable and much more nutritious than wheat bread ever thought of being. For instance, cot- tonseed meal contains about forty-five per cent. of proteins, whereas wheat only con- tains about nine per cent. Of these new grains, Kansas, Texas, and Oklahoma can supply enough to make up this year’s wheat shortage, while next year, with more planted, the supply will be abundant. Texas is capable of supplying the whole country alone if necessary, so that there is no danger of a bread shortage. Popular Science Monthly —- Sound. ORR ar re tg ~~ Cutting the top off a big fir at Puget It took twenty minutes to cut te esd 4 t ¥ a 3

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7134 i The College-Trained Elephant as a Circus Attraction ADIES and gentlemen,” begins the official barker at a side show, “‘it is your privilege to see before you the only living college-trained elephant in captivity, engaged at an enormous expense by the manager of this incomparable ag- gregation of world-fa- mous artists and animal shows!” With this he_ presents to the ele- phant, who looks inde- scribably bored, a piece of white chalk in an iron holder. a Be 8! some of the ladies or Popular Science Monthly is a Compass Necessary? Not if You Have a Watch ERE you ever out in the “wild,” carrying your map but without a compass? Your watch answers the pur. pose just as well. Disregard the minute hand altogether, Then note the arc that the hour hand makes with the noon of the day—not the midnight—and draw an imaginary line bisecting this are. Point this line _towards the sun and the XII wil] point toward the south, Referring to the dia- grams, the first one repre- sents 5.10 a, M. Theimag- inary line falls between the hour hand and the ap- proaching noon, ag shown. The gentlemen The “intelligent” elephant ‘and the way his brain second fig- kindly name works, said brain being in the head of the attendant ure shows some _ small the time to numbers?” suavely urges the barker and from amongst the spectators come calls of “Six—Two—Five!”’ “‘Six—two—five,”’ repeats the barker slowly and impressively and leads the graduate of the elephant college to the blackboard. To the astonishment of the spectators the chalk traces a perfectly legible ‘6’ upon the black surface. Underneath he writes a “2,” underneath that a “5.” Then comes the addition line and the result, 13. An attendant on the other side of the blackboard did the trick. For be 3.45 P. M., so that the imaginary line falling between the noon and the hour hand, practically coincides with the II. In the third it is 7.20 Pp. M. and the bisecting line still comes between the noon and the hour hand, so that it falls be- tween the III and the IV. The line must always bisect the arc, whether it is more or less than a semicircle. One’s watch makes two circuits while thé? sun makesone. Therefore half the arc be- tween the hour hand and the nearest noon, pointed toward the sun, causes the noon—the XII—to point due south. his benefit the barker repeated the numbers so as to give him time to pick out the same num- bers, cut out of sheet iron, and slip them into grooves provided for them. Then he grasped a powerful magnet and held it against the top of the six. To the same spot, on the other side, the barker directed the trunk of the elephant. The chalk holder be- ing of iron, followed the magnet. Dotted line in each case represents imaginary line bisecting arc between the hour hand and the noon 2 . / - bm te

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/ ss Re Be t+ OPO RES et te OU ee 7 Sa Oe. SS ae. a oe “we _ simply a sheet Here, Now, Is the ‘“Tappoon’’— a Portable Flood-Gate NTIL very recently it has been the practice among ranchmen when ir- rigating a field to dam up the ditch with mud in order to make the water flow into the lateral Popular Science Monthly 735 Fish at Night with an Electric Light on Your Line HEN the fishing fever has fastened upon him and is at its height, the enthusiastic angler would lengthen his day, if he could, to fully forty-eight hours. ditches. How- ard R. Wallace, a ranchman who lives near Long Beach, California, changed all this by devis- ing a portable irrigation flood-gate. The gate is of heavy-gage wrought-iron —the lower corners are rounded off One _ ingeni- ous American, probably spending anall- too-short vaca- tion in the woods, devised a plan for il- luminating the end of his line and thus tempting the fish to rise even on the darkest night. In the hollow interior of his bamboo rod he placed a small electric and a handle is bolted to its upper edge. When the gate is pressed down into the mud of a main ditch it holds the water back and diverts it into the lateral ditch immediately behind the dam. When that ditch has sufficient water the gate is ‘pulled up and moved to the next lateral. All the work of making scores of small dams with mud is avoided. The tappoon, as Mr. Wallace terms his device, is an inexpensive thing to make, and in the course of a California summer it saves many hours of hard labor. It is very light and can be easily carried about, and obviously has nothing to get out of order. To shift it one merely lays hold of the handles on each end and pulls it up, carrying it to the next location and pressing it in with the foot. This is one of the little things that count. It saves both time and trouble, and lightens the tedium of a thankless job. This is the tappoon. It is the invention of a Cali- fornian rancher and is designed to simplify irrigation The illuminated fishing line by means of which one can catch fish at night battery of suf- ficient power to operate two small lamps, one attached to the rod and one to a buoy just above the baited hook. The purpose of the buoy is to prevent the lamp from being submerged. The electric wires between the end of the rod and the buoy take the place of the fishing line. The light on the buoy not only serves to attract the fish but also by its bobbing informs the angler when a fish takes the hook and is due to be hauled in. This is an application of the old method of fishing at night with a light. The usual method, of course, is to go out on the lake in a boat, car- rying with you one or two hurricane lamps. One of these you keep in the boat to see by, and the other you fasten to the gunwale so that the light will attract thefish. Inthis case one uses an ordi- nary line, of course, and trusts to pure blind luck for results.

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7360 Popular Science Monthly Put the Tree in the Barn, Put the The Battle of the Bath-Tub Fought Cat Out, and Go to Bed with Toy Submarines HERE’S no accounting for taste. TOY submarine that really runs Here is an instance where sooner under water has been recently put than cut down a fine aaa on the market. It is old tree a new barn was built around it, the trunk passing through the roof. Whether this is due to conservation fifteen inches long and is constructed of wood and metal. As equip. ment it carries steering and diving planes, a or to sentiment we are deck gun, and a torpedo, not aware. It undoubt- The motive power is de- edly is a pity to cut rived from elastic bands, down beautiful old trees, but just the same one would imagine that a tree in the barn would be, to say the least of it, - inconvenient. Whether it is profaned inside the barn. with nails and hooks and harness, who shallsay? Whatever the reason, there it is, and it at least has the merit of being exceedingly pic- turesque in appearance and probably is unique. and the boat will travel from twenty to forty feet under water, at any desired depth, either straight ahead or in a circle. The torpedo is fired from the deck gun, and is controlled automatic. ally so that it is dis. charged to a distance of four or five feet as the boat rises to the sur- | face. Two boys, with two or three of these realis- tic toys and the neces- Ef Ye Cain’t Shoot the Critters, sary facilities for sailing them, can stage Dynamite ’Em all kinds of sham battles and naval ma- neuvers. Blockades can be carried out VERY simple and cheap method of and paper boats sunk in the most relent- destroying wood-chuck burrows less manner, while, with the help of has been discovered by a farmer. a few tin soldiers and ‘“‘land bat- He takes a stick about three- teries’’ enemy cities can be quarters of aninch thick and readily reduced to ruins and about ten feet long, and the garrisons routed. ties a stick of dynamite to the end, ready capped and with two feet of fuse. He lights the fuse and pushes the charge into the hole. As the fuse takes about a minute to burn down, he has plenty of time to tamp the earth around it and get out of the way. The explosion of the dynamite de- stroys the den and, the fumes being very poisonous, any animals which may escape the explosion are asphyxiated. This is a far simpler and quicker method than digging them out, and the The toy submarine which dives and explosion fills up the burrow too. circles. Note the heavy artillery it carries They built the barn around this a tree to avoid cutting it down

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The Farm Tractor As an Aid in Road Building N Atkinson, New Hamp- shire, the farm tractor has been successfully used in making and repairing roads, doing away with horses. A twenty-horsepower trac- tor, as shown in the picture, was used in conjunction with the regulation road-machine for rounding off the surface of the road and cleaning out It was found that the tractor not only easily does the work of six or eight gutters. Popular Science Monthly horses, but better and in less time. Two men only are required as com- pared with the four required with the former system. Besides, double the ground is covered. When the tractor is used with the road- drag, one man, driving the tractor, can round up and smooth as much State road in half a day as one man with a pair of horses in one day and a half. The tractor hauls four to six cartloads of gravel in the same time that a two-horse team re- quires for one load. Figured in dollars and cents, the trac- tor could easily do $24 worth of work at a cost of only $8, with an additional saving of from twenty-five to fifty per cent in time. Trapping the Wise Old Crow INCE time and ex- periment have proved that the aver- ‘age crow is perfectly able to decide whether or.not an object in a field can handle a gun, traps to lure the bird are now being One of the most successful of these traps assumes the form of a nest fastened se- tried out. This twenty-horsepower farm tractor proved itself a val- uable and efficient aid in road repairing in Atkinson, N. H. curely to the branches of trees, or to any convenient support in the locality to be protected. The nest is made of strong wire mesh, padded in much the same way and Above are shown various kinds of traps for catching the wily crow. The effectiveness of some depends on his appetite, others on his curiosity. Scarecrows are ineffective—he knows too much with about the same materials as if made by a mother-bird. But the nest rests on a delicately balanced spring which is op- erated by a lever just’ under the eggs. When the crow gives his first investigating peck, the two sides of the supporting framework: of the trap-nest come together like the leavesofabook,with . bonecrushing force. Another trap which has proved successful looks like a workman’s dinner pail. The cover is turned down, with just enough of an opening left to emit the tantalizing smell of cooked food. With hungry «lack of caution, the crow at- tempts to sweep the cover off with his foot, the two steel sides of the trap, which he had mistaken for han- dles at the side of the pail, come together and grab him by the leg, holding him with painful effectiveness to await thefurther venge- ance of the farmer.

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738 Popular Science Monthly A Fork and Spoon in One—Part of the Soldier’s Kit IKE other mortals, soldiers and sailors, in training or on active duty at the front, must eat. It is not often that they object to the punctual fulfillment of this duty, provided the “grub”’ is fit. Uncle Sam sees to it that it is “fit”? and that there is plenty of it. Every soldier and every sailor is required to carry his own kit, ‘ comprising knife, fork and spoon, and to keep it clean. There are many kinds of these kits in use, most of them combination uten- sils, planned with the idea of preventing the three parts of the kit from be- waters in search of food. Thousands be. come benumbed by the cold and remain stranded upon the shore when the tide recedes, an easy prey for the fisher, A Baby-in-the-Tree-Top Hammock HE jingle about the baby in the tree top, which represents ‘the height of juvenile com- fort, might serve very well as an advertisement for the hammock illus- trated. Made of open mesh which enables the air to circulate about the body, and equipped with a mosquito net and sun blind, it will accommodate a child up to four years Si of age. The baby in the ham- coming separated. One of Xnife-and-fork kit in detail mock is safe, for a lace these kits has the advan- andinuse. Itisverycompact which can be tightly drawn tage of being light, com- pact and simple. It con- holds the body, even sists of two parts only, - though the hammock ) should be tipped upside each stamped out of a single piece of steel. The knife forms one of the parts while the other part has a spoon at one end, a fork at the other. The two parts, which are heavily down. The device is made in different sizes to ac- commodate grown-ups as well as children, but the manufacturers claim that the child’s size hammock nickeled, are so arranged that each fits into a groove in the other part, so that the sharp edge of the knife and the tines of the fork are protected. Catching Fish Without the Use of Hook or Net HE scarcity of meat and the consequently increased de- mand for sea food has made the whiting, which is also known in dif- ferent parts of the Atlantic coast as “frost fish” and “‘silver hake,” extremely popular. This fish usual- ly begins running along the New Jersey coast in November and re- mains until the following May. On cold, frosty nights the fish leave their comparatively warm haunts illustrated is strong enough to hold a man, so that ample latitude is allowed to guard against all possible mishaps. This makes it eminent- ly suitable for general use in the garden. £ in deep water and seek the shallow An open-mesh hammock with laces to draw it together and a sun blind to protect the eyes mn te ee te oe ote 4 et ua tt

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Have You Weeds on Your Lawn? Kill Them With Gasoline HE complete elimination of dandelions, rag- weed, quack grass, and troublesome weeds that grow on the lawn is made easy by a device that elim- inates all back-break- ing stooping. The instrument consists of a slender tube filled with a liquid and pro- vided with a sharp point that is pushed into the heart of the Spring to keep valve closed pushed into roots of weeds to open valve « lution of iron sul- phite is used for pig weed, rag weed, and quack grass. The device is all metal, and very simple in construction; none of the metal parts is affected by the liquids. Pressing the ‘tool into the ground raises the valves and releases a little of the liquid. The tube may be filled by twisting the handle and remoy- ing the top. Popular Science Monthly 739 Efficiency Has Come to the Garden Rake * *e & i Ter Ra Sa 2 Zi £5 te SS es BN ck, Os, aN at At side detailed draw ing of weed killer. Above, the same in use on a lawn weed; the liquid then automatically runs out, and the weed is killed beyond the power to grow again. For killing dande- lions and most or- dinary weeds a gaso- line solution is most effective, while a so- NE day, Charles F. Reiter of Minneapolis, Minn., lost his patience when raking his lawn—and who wouldn’t, when the leaves seemed to take extraordinary pleasure in sticking between the teeth of the rake. After Mr. Reiter had bent down and pulled the leaves out so many times that his back ached, he threw down the rake, went into his house and invented a temper-saving, back- resting device which cleans the rake auto- matically. The automatic self- cleaning attachment is simply a curved piece of wire which, manufactured in any desired length to fit any rake, sets be- tween the teeth of the rake. Wire arms, operated by springs are attached to the handle and to the curved cleaning wire. When the rake touches the ground, the cleaning attachment is pushed up out of the way. The leaves or scraps are raked in the usual manner. But when the rake is lifted for the-back stroke, the wire arms are pressed down by two single coil This simple, self-cleaning rake is the out- come of a Minneapolis man’s impatience springs, and the curved wire in- stantly pushes out the leaves accum- ulated on the prongs. It will be seen that in addition to saving the trouble of cleaning the rake, all the leaves, etc., that are collected would be worked into the soil, thus helping to make the “leaf-mold” that is so highly valued by horticulturists.

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Homes for War Workers A new type of standardized dwelling which oo can be built by unskilled labor in two weeks \ By John Walker Harrington

Workmen’s houses of concrete, all different from each other, can be built exceedingly rapidly and cheaply AR workers’ dwellings may be y \/ built at about half the usual cost and in half the customary time by a novel method originated by Mr. Alfred C. Bossom, a New York architect, according to estimates submitted by him to the Council of National Defence. His scheme is the result of personal studies of actual conditions at leading American shipyards and munitions plants. It also embodies his experience as an ex- pert retained by large industrial corpora- tions in this country as well as by the housing committee of the London Com- mon Council. The construction is best adapted for fireproof materials. Wood may also be employed. SRK hk \ Two: TAnep~? coTTR Ge There next appear strange devices re- sembling the cradles on which ships are sometimes carried overland and from which they are again launched into the water. These house cradles are huge frameworks of heavy timber which are readily moved on roll- ers. Suspended from them at regular intervals are three up- rights of reinforced concrete or steel, or even wood, which are to be part of the skeleton of the one-story dwellings. The cradles are steadied against the pull of these verticals by counterweights piled on low platforms on their opposite sides and are adjusted by. wedges, until every- thing is made plumb. The pillars are then lowered into the trough, and their feet are soon embedded in concrete dumped into the foundation form from wheelbarrows. As soon as the cement hardens, the cradle is withdrawn and the next three posts are launched. As several cradles may be used at once in building a house, both the outer wall uprights and 4

Under the Bossom

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be no cellars, the work

of excavation is soon completed. particular one Here is a typical plan for one of the proposed cottages. This would be a two-family house, semi-detached 740

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those for the partitions may be quickly trued up and alined with each other. Meanwhile, the supports are being braced together by cross- pieces, as holes have been left in them all, where the horizontal beams may be secured. Short members are placed between the up- rights so as to permit the introduction of doors and windows, the frames of which can be wired in place. : At the same time workmen standing on stepladders put the raft- ers in position, making them fast with pegs and wire, just as the other beams have been fastened. No scaffolds are required. High rib lath is then attached to the sides and spread on the roof and firmly bound down. Fcr the walls two areas of wire web or lath may be used, so as to give further stability. The metal meshes are then plastered from within and as soon as the plaster has set sufficiently, stucco is applied to the outside wall with aeement gun. Because of the air spaces, walls of this character have a considerable advantage over those of the poured con- crete variety which often sweat and give the tenants of the house a sense of chill. The roof is also of stucco, handled in the same manner as that composing the walls. The portion of the concrete foundations rising above the earth serves as a base for floor joists and also incloses an air-cham- ber underfoot. Here then we have a fire- proof, vermin-proof, rodent-proof and damp-proof structure. Although these new models may be built from standardized parts, pleasing and attractive variations may be made by adding a gable here and there or altering the pitch of a roof. These one-story cottages can be erected for one family, for two or for three families, so that a village of them would not be cursed by sameness. The architect has had forty variations of the idea worked out in his drafting room. Further antidotes to monotony may be provided by painting the exterior stucco walls in different ry Popular Science 41 Trenches are dug by machine, and then the main sup- porting pillars are all dropped in together with a cradle tints, and also by devising striking color schemes for the shutters, the doors and the roofs, so that there may be no two houses together which appear to be ex- actly alike. Here the paint gun serves both beauty and economy. The cost of these dwellings can be kept very low, in the opinion of the in- ventor, because they can be built by unskilled labor under the direction of skilled foremen. Laborers whose wages would be only $2.25 to $2.50 a day could do work for which in ordinary construc- tion the services of carpenters and masons at from $5 to $7 a day would be required. Houses of this type, exclusive of equipment, could be erected, according to this plan, within two weeks of the time the trench digging machine went into action and under favorable conditions only one week would be required. The installation of a general steam or electrical heating system would be pro- vided for long in advance, or if stoves are used, the needed. warmth would be readily obtained. Lighting and plumbing, al- though requiring the services of skilled men, could be reduced to the simplest terms. One-family houses built under these specifications can be erected at from $700 to $1,000 each, including the cost of land in the average new industrial community. These standardized dwellings, the unit of construction, consist of a living room, a kitchen, dining-room, two bedrooms and

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742 Popular Science Monthly But the most admirable feature of the plan is this: the houses need not be all alike a bathroom. The two and three family houses would cost proportionately less. It is estimated that a four-room and bath. cottage built under the new method, could hardly be duplicated for less than $1,800 under conventional schemes of construction, using the same materials. The two family dwelling costing less than $1,200, with four rooms and bath and a porch for each user, is especially desirable. The price of lumber is now so high that the erection of wooden houses similar in design to those here described would cost from seventy-five to eighty-five per cent of the sum expended for houses of brick or reinforced concrete. Such costs, how- ever, vary greatly according to localities and the accessibility of supplies. Lead- ing architects agree that after-the-war developments will justify the expense. Real Lights for the Automobiles in Motion Pictures . R. LANGDON McCORMICK of New York thinks that the present motion picture representations of night scenes are not sufficiently realistic, especi- ally in their lighting effects. It is his belief that representations of light on the screen, such as lamppost, automobile, and locomotive lamps, should be lights in reality, instead of pictorial representations. ; As most night scenes projected on the screen are photographed in daylight and tinted blue to give the night effect, it is true thai there is an absence of glow. But from our knowledge of motion pic- ture projection we fail to see a practical need in Mr. McCormick’s invention. He proposes to arrange a number of tracks behind a translucent screen, upon which actual electric bulbs are to be dragged along by motors. These lights will be caused to move about on the screen to correspond with the ever changing positions of the lights in the picture. How this corresponding movement will be accomplished we do not know, but we are certain that if it is at all possible it can be accomplished only more or less successfully in a direct side to side or up and down movement which involves no perspective changes. As regards objects which come forward or recede in the perspective of the picture it is well understood that they change their size during their movement. No provision is made for this change in size of the traveling lights and if this method were actually applied to a pic- ture of an automobile going away from us into the distance the car would be seen to diminish in size while the tail-light would rem:in unchanged, and this effect would continue until the machine became much smaller than its tail-light. Literally speaking the automobile would disappear in a blaze of tail-light glory.

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Killing Bugs with Dust This new way of exterminating insects in orchards is fast superseding the old spraying method Dusting machines in use in peach orchard. The powder is contained in the hopper and a blower forces it through the feed pipe under pressure by air blast, thoroughly dusting the trees poisons intended to kill orchard in- sects with water. A new method is now employed. The trees are dusted with the powdered mixture. The tremendous advantages of the dusting method, and its success in con- trolling the insect pests and diseases have led to its adoption by many growers of fruits, especially in New York. A man living at Middleport, New York, has recently perfected a high-power machine which pumps the dust on the trees. Dusting is twenty-five per cent cheaper than spraying. Orchards which it former- ly took three men and a team two days to spray may be given the same protection against most insects and diseases with two men and a team in three hours time. The total weight of the dusting machine complete with gasoline is less than one thousand pounds. Wet seasons, soggy or roughlandin no way interfere with dusting. Z was formerly the custom to mix the 743 The dusting mixture is placed in a hopper. A blower, which rotates at ap- proximately 2,500 revolutions per minute, forces a current of air through the air chamber at the bottom of the hopper. The dust is sifted through a slide feed and carried with great velocity through the outlet pipe. At the mouth of the pipe the flow is broken and the dust particles burst into a dense smokelike cloud, which will cover thoroughly a large apple tree almost instantly. Beneath the plate at the bottom of the hopper is a slide feed regulator consisting of two diagonally slotted slides which work over each other. The position of the slides is controlled by a small hand lever conveniently located at the end of the hopper near the discharge pipe. The operator is thus permitted to regulate the amount of material to be discharged, which may be of oneamount for appletrees, another for cherry, and so on. SOE es reas

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Popular Science Monthly This ladder will not slip, buckle or collapse A Safe Ladder Appears. You Can’t Break Its Rungs HARLES J. BROWN, of River Falls, Wis., is the inventor of a new ladder which combines many advantages and novel features. His ladder is light yet strong, and its rungs, which are of metal, are so fast- ened to the wood- en rails of the lad- der, that the struc- ture becomes per- fectly rigid. The rungs have a flat tread which prevents the foot from slipping. Safety devices are provided, which prevent the slip- ping of the lower end of the ladder on smooth or un- even ground, and the slipping side- 10 I VPOZ2aErAA KH BAINMIAQs,D, ways of the upper age ee it a locking device, invention 13 14 15 LITTLE ROCK HOT *SPRINGS CAMDEN which makes it possible to use the in- vention as a roof-ladder, or in place of a trestle without extra braces to prevent the spreading of the ladder at the bottom. The ladder may be used either as an ordi- nary extension ladder or as a step-ladder and its rigidity enables it to stand the most severe tests. Chemicals and Machines Supplant Men In This War HIS is the most scientific war ever fought. There is less dependence on man-power and more on machinery than at any time in the history of the world. We pin our faith to high explo- sives, poison gases, tear shells, gas masks, liquid fire, etc., all of which are applied chemistry, and to machine guns, heavy artillery, automobiles, submarines, air- planes, and so forth, which are very much refined mechanics. The greatest minds in the scientific and mechanical world have pooled their brains and obtained wonderful results. Place-Finding on Maps Is Made Easy by New Device HE system of using index letters and . numbers to enable one to find any spot on 4 map by referring to an in- dex has been am- plified by a device primarily designed for wall-maps, but could doubtless be adapted to smaller ones too. A rod a slides along the top edge of the mapand carries a movable indicator. The in- dicator is first ad- justed to the prop- er place on the side index, and then the rod is moved along until it coincides with the correct letter or figure on the top index. The indicator then automatically points to the de- sired place.

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Warming Both Engine and Car Body An apparatus that will keep you warm and avoid cracked cylinders too HE problems of keeping the engine ‘i of an automobile warm during freezing weather so as to prevent cylinders from cracking, to make starting easy and to heat the body interior for comfort are solved by the combination engine and body heater shown in the accompanying illustrations. The apparatus works on an entirely new principle and lg of a coil-heater red by a _ gasoline- ot The coldest nila jd out water is taken from ginger the bottom of the that the amount of fuel required to run the heater is negligible and that its use in reality saves considerable fuel because it is unnecessary to flood the carburetor when starting the engine. By keeping the en- gine warm, the fuel vaporizes more com- pletely so that its full power is immedi- ately utilized and not wasted in passing out through the muffler. The heater can be applied to any make of automobile, motor truck or ambulance. It can keep the temperature inside of any of these vehicles at from seventy to eighty degrees Fahrenheit.

radiator, heated, and i “ees The apparatus is not very injected into the top ———) difficult to install, for of the cylinder water- i it is compact and self- jacket or circulated Drain at Oe oe, Asbestos contained. When a through a small radia- ) and the proper connec- desired by manipulat- echt tions run to the vari- ing a small by-pass = Fyerin ous necessary points. valve. In any event, SUP il It has the great advan- the water finds its way ae | = tage of being indepen- back to the bottom of sar dent of the engine. the radiator, thus com- Air in radistor— > ~ Bi he cycle of Details of a gasoline fired water heater German Tires are The complete ‘ heater, weighing but ten pounds, is bracketed to one side of the engine. It consists of a lagged cylindrical barrel containing two coils of copper pipe and a gasoline-burner at the bottom. The fuel is carried in a tank on the running-board and is fed under pressure through a special re- ducing-valve to the burner so that the heater may be in operation during a short wait at the curb in theday or at night when the car is garaged. It is claimed for warming up the car and engine Showing situation of the heating unit under the hood of the car 745 Filled with P.ags UBBER tires for automobiles are reported to be practically unobtain- able in Germany and Austria and to give to the wheels some kind of protective elastic cush- ion, tire casings are stuffed with any material that affords some degree of resiliency, like cork, paper, rags, etc. In some cases the rims are without tires at all.

eens Sane aaa SSO RETO

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746 A Simple and Effective Heat- Economizing Stove T a recent exhibition of heating ap- pliances in Paris, a simple heating stove of sheet iron was shown, which, it is claimed, greatly econo- mizes heat and fuel. The stove is intended for burn- ing vegetables, fuels of low heat value, such as wood, peat, sawdust, bark, etc. In outward appearance the stove resembles the so- called ‘‘cannon stoves” Popular Science Monthly sprayed on DIAPHRAGM ~ CONNECT= 1 which were so popular in es ; this country about thirty The hot gases of combus- years ago. The characteristic feat- tion and the smoke can- not reach the flue with- out passing around the ure of the stove is a sheet- diaphragm of this stove: iron diaphragm, running diagonally from below the drafthole lead- ing to the flue, upward and toward pounds. the front of the stove. duced by the combus- tion, the smoke and the heat, instead of passing immediately to the drafthole and to the flue, are compelled to make their way up in front, then around the edge of the diaphragm, then down in the rear of the stove, to the draft- hole. On their way out they heat a greater sur- face of the metal of the stove, giving it greater heating power without increasing the amount of fuel used. Paint That Barn by Machine R. F. L. BENE- DICT, of Bal- timore, has perfected a device for spraying paint and distributing it over a surface by means of rotating brushes. The device consists, in its main features, of The gases pro- two rotating brushes with a space be. tween them, sufficient for the paint to be to the surface to be painted, A nozzle provides the Meang for spraying the paint. The brushes are rotated by small turbine engine oper. ated by compressed air, which is also used to foree the paint to the nozzle and to spray it. The engine jg connected with the brushes by a chain of gears. The flow of paint and of the air for the sprayer is regulated by a valve operated by a trigger combined with the handle. The brushes are covered with an aluminum ease and rotate towards each other, by which ar. rangement a spattering of the paint is avoided. The total weight of the device is about gix Trials with this device have given satisfactory results— y considerable econom ey in the cest of Jabor and in the amount of paint used and more satis- factory workmanship, The rotary painting machine spreads the paint evenly and well Details of the machine, controlling devices lat-latel ts showing the gearsand . |

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Popular Science Monthly 747 Tilting End-Pieces for Your Remarkable Photograph of an Eye Glasses Actual Battle Scene RE you one of those unfor- NE of the most remarkable A tunates who arecompelled war photographs taken by to go through life with spec- the official photographer of tacles before their eyes? the British army in France If so, a clever little device is reproduced in the ac- recently patented, will be companying picture from of interest to you. The the excellent enlargement, device consists of a fric- eight by fifteen feet in tion hinge connecting size, which was recently the end-pieces with placed upon exhibition. the lenses in such a This picture, probably manner that by a the largest war photo- slight turning of the graph ever made, shows a frame of the glasses wide portion of the battle- | the lenses may be field during the actual ad- brought vance of the Canadian into any troops at Vimy Ridge, .on angle rela- ee the morning of April 9, tive to the 1917. The smoke in the eyes and ERS “7 An adjustable background is produced by held in wy ont — = the counter-barrage of. the that po- pein ea angle Germans, which was par- sition as ticularly aimed at a line of long as it is desired. Thenew end-pieces tanks. The Canadian curtain of fire has are simple and have no parts that will get already swept over the battlefield and is out of order. no longer visible. hei Underwood and Underwood - This is probably the biggest enlargement ever made of a photograph. It shows the Canadian advance at Vimy Ridge and measures eight feet in height and about fifteen feet in width

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748 NE of the Popular Science Monthly The Traveling Brush-Burner. Orchardists Please Notice Static Electricity Drawn From Paper by Alternating Charge simplest and yet the most conve- nient devices built for or- chardists is the sheet-iron brush-burner built by Wm. Miller, of Gypsum, O. Mr. Miller NE of the most an- noying sources of trouble to printers ig static electric. ity in the pa- per. It causes the sheets, during the process of printing, to adhere more had this con- structed for use in his own orchards and therefore did not have it patented. In consequence fruit growers are helping themselves to the result of Mr. Miller’s thinking. The burner is made of one-sixteenth inch sheet iron, riveted together as shown in the accompanying photograph. It is practically a large cyl- inder with top open _and both ends closed. The top is opened the entire length, but just wide enough to admit the brush. The heat is forced upwards, rath- er than outwards, thus preserving the nearby trees. This burner is mounted on sled run- ners. After an orchard has been pruned, the men drive through the orchard with a big blazing fire in the burn- er. The brush is burned as they drive along. In this manner much time is saved. When the burner gets full of ashes, the own- ers have at their com- mand a product that ranks high in potash, a scarce yet necessary fertilizing element, so that this apparatus effects great economies. This portable brush-burner saves much time in haul- ing and provides valuable potash for the proprietor or less firmly to the cylinder or the delivery mechanism of the press and to other sheets. The speed of the work is reduced, exact registering is made practically im. | possible and even stacking, whether by Static electricity is solely responsi- ble for the difference in appearance hand or by machine, a matter of the — greatest difficulty. An electric neutralizer has been in- vented which complete- ly does away with all troubie from statie electricity. It supplies an alternating charge of electricity by means of a small motor gen- erator which gives an alternating current at about a _ seventy-volt pressure. This in turn is passed through a transformer where it becomes a current of high pressure and small quantity, ready for de- livery to the paper through distributing bars on the press. These bars are com- posed of a number of fine metal points set in porcelain insulation. A bar is located near the cylinder and drop guides and, if neces- sary, one is attached to the delivery. As the sheets pass under a bar > the charge of static electricity is drawn out. Her Tha ence lady stru wra thin leat stra the abo

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Popular Science Monthly Here’s the Way to Acquire Pickford Curls EMININE hair is usually curled by “‘kid’’ curlers. That designation has no refer- ence to the age of the young lady but to a type of con- struction involving kid leather wrapped about and sewn upon thin flexible metal rods. The leather rods are wrapped about strands of hair at night. In the morning the rods are re- moved. Curls have grown about them overnight. But at what sacrifice to the youth- ful wearer! Kid curlers form hard lumps about the head, and hard lumps are painful. Sleeping with one’s hair done up in such barbaric fashion is comparable to reposing upon a pillow covered with small hard rocks, which is not conducive to sleep. But along comes Miss Ella M. Pickard, of Oklahoma, who has found a way to ob- tain the Mary Pickford curl without the discomfort. Miss Pickard has applied for patent rights upon a hair curler which, to our first horrified masculine glance, ap- peared to be a fat Havana cigar dangling from a young lady’s scalp. Closer in- spection brings to light a roll of soft cloth, having at either end narrow cloth straps. The young lady who is about to enhance her crowning glory simply gathers the strands of her hair together, wrap- ping them snugly about the soft cloth rolls. The narrow straps are then brought togeth- er at either end of the rod, serving to hold the curl in place. When sufficient curls have thus been set in process of manufac- ture, she retires. The softness of the rolls prevents sleeplessness. And in the morning Mary Pickford has an- other rival. Painless dentistry has nothing on painless hair-curlers. This fountain is a by-product of saving the trees from destruction by building an “island” around them Mary Pickford curls are produced by this curler Los Angeles Values Her Trees and Conserves Them HEN the city of Los Angeles recent- ly cut North Broadway through Holgate Square there was a clump of fine old pepper trees directly in the path of the grading. So the city, rather than cut the trees down, built an “‘island” around them. An unusual feature of the island is an ornamental drinking: fountain. which was built: for the purpose of supply-’ - ing thirsty motorists and: ‘pedestrians with a. re-: freshing draught. of Adam’s ale. The water is piped to the fountain from a street. main. The Life of an Air- plane Is Short HE number of German air- planes destroyed by the French aviators and the members of the Lafayette es- cadrille for the ten months ending October, 1917, was one hundred and twenty over the French lines, and three hundred and ninety- seven over the German lines—all totat wrecks.

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750 Popular Science Monthly x Pa to the drying shelves ex. tending over the yards, The mechanism igs go simple that it cannot easily get out of order. It re quires but little attention and practically eliminates the necessity of employing wheelers and truckers, who are generally considered the most uncertain and annoy- ing labor in the yard. In these present topsy- turvey times, when men have to be done without and women have to step more and more into the men’s shoes, labor-saving machinery of this kind as. sumes an importance that This brick-conveyor is worked on a similar principle to the familiar cash-conveyor of the department stores . Brick Manufacturers Find This a Great Labor Saver HE conveyor system illustrated in the pictures has been installed in many brick-yards in various parts of the country, and, as the owners of the yards willingly testify, has proved a valuable labor-saver. It is estimated that for a yard with a capacity of about 50,000 bricks the installation of this conveyor would mean a saving of four or five men. The system is simple and, in a general way follows the idea of the cash and parcel conveyors used in many department stores. Two endless wire cables, running parallel and supported by grooved wheels form the basis of the conveyor. The cables are stretched taut so as to support the conveyor planks and the bricks placed upon them. The tension of the ca- bles can be regulated by a screw. By an in- genious switch arrange- ment provision is made for the turning of cor- ners by the conveyor planks loaded with it never did in the piping times of peace. Protecting the Aviator’s Camera Bellows from the Wind AKING photographs from an air- plane with an ordinary folding pocket camera is utterly impossible if the leather bellows is not protected from the wind, as the aviators are exposed to the terrific draft created by the revolving blades. Add to this the breeze created by the machine flying along at ninety or one hundred miles an hour and you can see why, if an ordinary folding camera is un- folded in an airplane, the wind immediately flattens the leather bellows. To overcor.ie this diffi- culty and to be able to procure a series of aero- nautical photographs John Edwin Hogg, of Los Angeles, California, constructed the alu- minum bellows shield illustrated. It worked perfectly, and with it he procured the photo- graphs desired. The shield weighs four ounces, and when folded can be carried in the bricks and for the dis- tribution of the bricks Aluminum case prevents wind in airplane flattening bellows coat pocket. It may be very quickly adjusted. So! a! Sep a, hy roy

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Some Do’s and Don’ts for Automobilists Economy is in the air these days. To automobilists this means saving fires, gasoline, oil, and everything else Don’t keep your engine racing and banging away when you are waiting for traffic to move Don’t adjust non-skid chains so loose that they fall off, nor so tight that they won’t take hold Don’t use chains on dry days to tear up the road- way; the Roads Committee will attend toall that Inspect oil level in engine, amount of water in radiator, and tire pressure every time out Don’t wait un- til small cuts in your tires be- come gaping rents, have ’em See that brakes and brake linings are all in or- der. You may need them in a hurry on fixed before that Don’t engage your clutch sharply, apply your brake harshly, orround corners too fast See that your tires are giving you service. Keep records of them and com- pare with others Drive with spark advanced as far as possible with- out causing your engine to labor, knock, or miss Study your car. Learn all its ins and outs and how to make mi- nor repairs. You will save: money Don’t wash your car ‘with gaso- line. The meth- _ odis wasteful, very dangerous, and very foolish Don’t pull your engine to pieces for the mere joy of the thing. It’snot a clock and you’re grown up now aN \ Don’t over-lubricate your en- gine and drive with the cut-out open. It’s noisy and smelly It’s cheaper to cover the radiator or to use non-freezing mixture than it is to leave engine running

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152 Popular Science Monthly Transporting Oil Tanks Intact One Hundred Miles O convey over a distance of one hundred miles three big oil-tanks weighing in the aggregate two hundred and ten tons, without taking them to pieces, was the novel engineering feat accomplished on Vancouver Island, by Mr. S. Doe, a Victoria contractor. They were located twenty-two feet above tide- water at low stage. In order that they might be transferred to scows, trestles were built about one hundred and fifty feet from the shore line, and the whole structure to be lowered in sections. Thirteen foot poles were fixed on the scows and then run under the tanks as they rested on the trestle at low water. When the tide was at its highest the upper part of the trestle was removed. When the tide receded the tank rested on a lower elevation. This performance was repeated three times before The first tank in posi- tion and’ the second being hauled ashore The tank being towed to Powell River on a scow; tugboat at side Have You Got Any Use for an Abandoned Locomotive? BOUT twenty-seven miles from Yu- ma, Arizona, a sorry looking loeo- motive has been abandoned in the Colorado Desert. The engine was left at a gravel pit, and a flood swept away most of the track between it and the main line. Inasmuch as the locomotive js worth but ten thousand dollars and the cost of rebuilding the track would be something like fifteen thousand dollars, it is obvious that it will not be reclaimed. All parts of value that could be moved — readily were stripped off, and the engine left to itsfate. Standing out prominently in the sandy expanse, it is an object of considerable interest to the curious. the tank was on the scow. The tank-laden scows were towed to Powell River, where in the meantime another trestle had been built out from the shore to receive the tank at high water. The. final operation was aot without its difficulties. The foundations for the tanks were more than 600 feet up a ten per cent grade. A track was built and the tanks pulled up the hill by an engine. Cost of engine, $10,000. Cost of track to rescue it, $15,000. Result, engine abandoned to its fate

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Handling Hot Firebricks with Asbestos Mittens HEN it becomes necessary to repair the firebrick arch in the fire-box of a locomotive the fire is knocked out and steam blown down to about half- gage pressure. Then the blower is turned on and a man enters the fire-box to make the necessary re- pairs. The heat is intense and is bear- able for a_ short time only owing to the stream of cold air blown into the fire-box by the blower. The man must handle the hot firebricks quickly, yet gently enough to prevent their breakage. To ena- ble him to do this he wears mittens of canvas with a protective layer of asbestos onthe palmsideto avoid burning his hands. These mittens can be made for about thirty-five cents a pair, and some of the. large railroads have introduced their use as a matter of economy. Fifteen loco- motives can be repaired before these gloves wear out, so that the cost for each locomotive is about two and one-third This is a profitable investment. The injury to the hot firebricks, when carelessly handled, as they would be without gloves, would represent a loss many times greater than the cost of the mittens. In fact it would be very cents. difficult to handle them at all, since the bricks hold the heat for a long time. Asbestos is be- coming more and more a necessity in modern indus- try, both for small conveniences and large apparatus, and this is only one more use. Popular Science Monthly Asbestos-lined mittens enable the man to remove and handle the hot firebricks saddle. of the seat. Who needs legs anyway? "This novel vehicle is a poilu’s idea for circumventing leglessness 753 Telephone and Telegraph Service in Argentina Held Up by Spiders | Beene the dry season in Argentina a certain species of spiders’ webs col- lects on the telephone and telegraph wires in enormous quan- tities. As soon as the sun sets they become soaked with dew and cause short circuits between the wires. Eleven pounds weight have been swept from four wires over a distance of six miles. Leglessness Is No Drawback HE Frenchman is nothing if not ingenious. Here is a poilu’s answer to the embarrassing question of how to do without legs. It consists of a kind of tricycle with very exaggerated handlebars, and a wicker seat, comfortably mounted on springs be- tween the two back wheels, in place of a The driving mechanism is repre- sented by a regular bicycle driving-wheel, having handles instead of pedals, mounted between the long handlebars in easy reach This drives a countershaft, having a sprocket at each end, by means of a long chain, which, in turn, is con- nected with the front wheel by a shorter vertical chain and sprocket. Steer- ing is accomplish- ed in the same manner as steer- ing a bicycle. It is said that this machine will make fifteen miles an hour on a good road with a husky, legless “engine.” It is thus shown that even legs are not really indispens- able.

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754 Popular Science Monthly

The illustrations show the detail and operation of a new braking mechanism that it is proposed to fit to airplanes so that they may be handled more easily Band brake Wire pull Braking an Airplane While Flying BRAKING mechanism for airplanes has recently been introduced. This consists of two rect- Even the Laundrymen Are Affected by War Conditions OW it is the laundrymen’s turn to feel the pinch of war conditions, They formerly used caustic potash in combination with soap for bleaching pur- poses. But now that potash is almost unobtainable, a good substitute has be- come necessary. The recent increase in the price of soap has made the need acute, And now comes a satisfactory domestic bleach. Three pounds of _ tri-sodium phosphate to twenty-five pounds of soap. is the formula.

War Sees Return to Ancient Weapons NE of the remark- able features of the present world war is the revival of weapons, methods of attack and of defence which origi- nated a long time ago. Trench warfare is nothing new, but merely a modern elabo- ration of one of the oldest methods of de- fence known. The steel helmets, shields and breast plates adopted by practically all of the armies

angular planes of small area, mounted on a shaft that runs along the rear edge of the main plane, and passes through the fuselage. The control is by means of a handwheel and connections, which act in conjunction with a hand-brake. When an airplane is flying at a rate of a hundred miles an hour, the air pres- sure is not less than thirty pounds to the square foot. It will thus be .seen that the added resistance of a few extra square feet of can- vas has a very great retarding action on the speed of the

© Kadel and Herbert

Hand grenade, shield, steel helmet— engaged in this war are adaptations of types that had been in use long ™ before the birth of ' #a| Christ. The illus- tration shows an- other revival. The French soldier pic- tured is in the act of throwing a hand grenade into the German trenches, perhaps only fifty or sixty yards dis- tant. These hand grenades, which are extensively used in trench warfare, are terrible weapons. They are filled with the most powerful explosives and great care must be taken to prevent their premature ex-

plane. medievalism personified. Nothing is new plosion.

~<ht eet OS Se eC Ol

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As Flexible as India Rubber but Infinitely Stronger WONDERFUL pipe-metal is now in use which seems to be able to stand any amount of rough usage. Our illustra- tion depicts instances of torture to which it has been subjected without destruction. The ‘section that looks like a piece of crumpled rag was in an Oklahoma oil well when it was “shot’’ with one hundred and seventy quarts of nitro-glycerin. It shrank from eighteen feet to six feet in the process, but declined to break. The twisted piece is a section of eight-inch pipe, weighing about twen- ty-eight pounds to the foot, and. having walls five-six- teenths inch thick. As a pipe it is not of much further use, but as a proof of metallic strength it is a masterpiece. The figure- eight knot is tied in a pipe having a ten- sile strength of fifty-eight thousand pounds per square inch. These are only typical instances of what this uncanny metal will withstand. A twenty-six-length pipe, five hundred feet long, was blown bodily out of a Texas gas well. It lay across the landscape, twisted and turned like a gigantic frozen snake, but all its welds and joints, and the metal itself held on like grim death. The joints held, the welds held, and the metal itself was intact. There was not a break or. flaw anywhere throughout its great length. As will be seen from our illus- tration, it is twisted and contorted like a garden hose, and when one considers that it is welded metal it is indeed wonderful. This piece of pipe was originally eighteen feet long. Nitro-glycerin crumpled it up This pipe has a tensile strength of 58,000 pounds to the square inch 713,000 inch pounds twist- ed this without fracture Popular Science Monthly 755 Lengthen Your Cast with the Mercury Fishing Line NOVEL improvement in fishing lines is one which is made half of mercury. The process by which it is prepared is one which makes the fibers of the line absorb a mercury compound. This compound is many times heavier Jine itself, so that the finished fishing line will be consid- erably heavier, though of even less diameter, than the or- dinary. ' A plain fiber fishing line of relatively small diameter is immersed in a bath containing a mercury compound. The mercury is then made to precipitate out of the solution and in through the crevices between the fibers. The fishing line is next tak- en and dressed with a mercury ointment. When this dries, the thin fishing line will be coated with a smooth, glossy surface. Then when the line is cast the friction between it and the rings of the fishing rod, as the line plays out, is much less than with other lines. Moreover, the smaller diameter of the line makes the resistance of the air upon it less than in other cases. The drag of flowing water will also be reduced. There- fore not only will the cast of a line be greatly lengthened with this line, but, in addition to this, the line will “‘stay put.” Now, all you disciples of Ike Walton, here is a new departure. Try it out on your next expedition after the fickle trout or black bass. We stake an editorial blue pencil, though, that you’re scared to try it out on a ‘‘musky.” I ying like a gigantic frozen snake across the landscape, this piece of pipe has all its joints and welds unbroken after being blown bodily from a gas well in the southern oil fields

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Picking Cotton with a Vacuum Cleaner This machine does the work better, quicker, and without the waste of hand pickers CCORDING to Government fig- ures, hundreds of millions of dollars are yearly wasted by the careless picking of cotton. In some cases 50% of the crop is left on the plants. That ex- plains the two thou- : outclassed the hand pickers. What is more, the cotton it picks is even cleaner than that of the hand pickers’ baskets, The machine—called the Gabel-Holda- way—consists of a light steel chassis, sup- : ported on three. sand patents for mechanical cotton pickers -that have been taken out. Not one of the in- ventions disclosed ‘has proved com- mercially success- ‘ful. About a mil- lion persons are still engaged in the pick- ing, ginning, baling and transporting of the white fluffy stuff that goes to make up everything from gun cotton to our “pure silk shirts’? and other daily necessities. As an article of . Showing the Stiaeepichion omler § in oper- ation. Note the compactness of the cotton steel wheels for the sake of easy hand- ling. On the chas- sis supporting is a sixteen horsepower gas-engine, which drives a suction pump and a centri- fugal separator. A light steel pipe runs across the machine, and from this run five eighteen-foot light rubber pipes, terminating in the peculiar picking nozzles, which the inventor claims are the reason for the success of the ma- chine, together with commerce, cotton was almost negli- gible until Whitney invented the cotton gin in 1793. The American pro- duction of cotton, which was only two thousand bales in 1791, was instantly stimulated, with the result that in 1801 it had risen to nine- ty-two thousand bales. Since then, it has shown a constant increase, inter- rupted only by the Civil War, during which time, of course, but little cotton was grown in the states of the Con- federacy. During the present war, cotton has come to the front as a very important factor in the actual winning of the war. Not only is it of importance in the textile industries, but more particularly in the manufacture of explosives. Down in the new cotton country of the Imperial Valley, a reclaimed desert of Southern California, there is now working a cotton picking machine that has already Five men, one at each og are all that are necessary to carry out the picking the centrifugal sep- arator., Five men operate the nozzles, one to each. The pump sucks on the hose. The manipulator of the nozzle merely sweeps it across a row of bolls, and the white fluffy cot- ton is sucked into the nozzle and then through the pipe to the separator. Here the cotton is separated from the incidental leaves, and from the motes. Next the DELIVERY PIPE I), SUCTION PUMP AND Wi), CENTRIFUGAL SEPARATOR . WERA LIGHT WEIGHT AO} Wea RUBBER SUCTION PAN Ree P'Pes moccer (SN INS, Diagram showing details of the cotton-pick- ing machine, which is not very complicated 756

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cotton is blown through the pipe running to the rear of the machine, where it is caught in sacks or baskets, while the finely broken up leaves and dirt are blown through openings in the pipe by which the cotton passes in its course. Working ten hours a day, the machine is stated to pick one thousand pounds per nozzle, or five thousand pounds per day in all. Hand labor picks about one hun- dred and fifty pounds. Weighing but one thousand pounds, the mzchine is easily moved along by means of a horse. The perfected model will use a transmission arrangement to the rear wheels, and be driven under its own power. The superiority of the machine over hand labor was plainly shown in the Im- perial Valley, where the intense heat ‘makes hand labor hard to obtain, and in- efficient when obtained. It proved easier to obtain five men at good wages to manipulate the nozzles than to secure the picking equivalent in hand labor during the hot months. A successful cotton picker, as_ this promises to be, means an enormous saving in the cost of cotton production with no lowering of the profit to the planter, and the release of hundreds of thousands of badly needed laborers for other fields of endeavor. We have heard much lately concerning the migration of the negroes northward. As they are the pickers of the cotton, may not such a machine as this have some little bearing on the future Southern economics ? Popular Science Monthly Grownups who are not still young enough to climb trees are barred from entering This Tree-House Is in Massachu- setts, Not in Africa MAN in Salem, Massachusetts, has built a playhouse in a tree for his children. It was given its lofty position in order to add novelty to its other attrac- tions. An old tree with two branches extending straight out in two directions lent itself admirably to the purpose, but in order to make the location doubly secure, props were put under Here is the gang at work. The pickers are at the nozzles and the machine is standing end on the limbs and a rod was run through the main branch of the tree and through the little house itself to the support in the rear. Thus it was made wind-proof and rigid and firmly supported. Entrance to the house is gained by means of a ladder, if you are not agile enough to climb a tree. During the summer, when the leaves are on the tree, the children of the family have a delightfully cool and shaded place of their own. Here they reign supreme and can amuse themselves in any old way they wish, without “getting on the nerves” of the grownups. ne

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near both of them. kerosene, when undiluted or un- mixed with air, burn after ignition gradually and without explosion, but explode with great force when mixed with air-in certain proportions. In the case of gasoline there wor will be no explosion if less than 1.4 parts by volume of gaso- ~ jine are- contained in 100 parts of the mixture, or more than six parts. In the case of kero- . gene the range. of explosibility is very much narrower than with gasoline, and the danger of an explosion, there- fore, much smaller. In practical: experience it was found that kerosene is much safer to handle than gasoline, besides being more economical. ‘In many cases appliances formerly used with gasoline have been adapted to the use of kerosene. Among these appliances ce vapors of gasoline as well as of 2Gal safety can (qreen color) 4Tn f Showing the method are furnaces and blow-torches which have been so adapted and are giving They .are now extensively satisfaction. Cleaning pl Wire pi iyo 8 Construction of modern kerosene furnace and parts used in electrical work Less Risk in Kerosene Than in Gasoline But sand or sawdust should be kept ‘used by plumbers, painters and elec. S. unnel’. : with (oo mesh)strainer & kerosene furnace from a new safety can as an extinguisher tricians. _ Wherever gasoline or kerosene is used, the greatest precaution should be taken, to prevent leakage or the spilling of part | of the liquid, especially in a confined space. Gasoline or kerosene should never be kept in pails or open receptacles of any kind, but in prop- erly constructed safety cans, similar .to that herewith shown. All taps to tanks should: be fitted with drip pans. Children and unauthorized per- sons should not be allowed near places where gasoline or kerosene is stored, and the rules against smoking and the use of naked lights in such places should be strictly enforced. Sand or sawdust in large buckets should be kept in all places where gasoline or kerosene is stored or handled, to be used as an extinguisher in case of ignition. Sawdust is not easily ignited and, as it floats upon the burning liquid, it helps to smother the flame. Sand is also good, Automatic valve which el Gi ee el, ee ee eee Oe tee OO Hf Supply valve ’ closed > of filling a modern Packing Lock Generator Cleaning Jet block Generating nut needle/_Orifice / tubes \ oS — Cleaning plug7”_E ( Aor La Details of a kerosene torch. The high price of gasoline may bring this into favor 758

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Popular Science Monthly No Race Suicide Among the Bacteria “T)ACTERIA reproduce with almost incredible rapidity,” says George W. Hunter in “A Civic Biolo- gy” (American Book Com- pany). It is estimated that a single bacterium, by a process of division called fission (dividing itself into two parts) will give rise to over 16,700,000 others in twenty-four hours. Under unfavorable conditions they stop dividing and form round- ed bodies called spores. ' These are exceedingly diffi- cult to injure or destroy. © Underwood and Underwood They. will not vivisect him. Ee tried to argue War Provides an Expensive Clothes-Rack HE queer thing in the middle of the picture, which resembles a monster porcupine used as a clothes-rack, is the stump of a tree which grew ‘‘somewhere in France” until a German shell struck it and cut the trunk of the magnificent tree in two. The exploding shell splintered the wood in such a manner that the stump, with its radi- with the horseshoer, so they had to persuade him Army Horses Must Be Good- * Tempered T’S a weary, wicked world if you are an army horse. You may or may not approve of shoes, but you’ve got to have them just the same. The French author- ities have an ingenious contrivance which so pinions a horse that he has absolutely nothing to say in the matter. It holds his head, and holds his feet and ating big splinters “was used by the French soldiers en- camped there as a rack upon which they hung their clothesand military equipment. The rack may be con- venient for the soldiers, but this is really too expensive a method of making clothes-racks. Be- sides, stumps are not always handy, and then the shell may miss them or they may splinter in some inconveni- ent manner. After all, the regular pat- tern cannot be beat- en for “steady” use. © Underwood and Underwood How a German shell provided a very convenient clothes-rack for French soldiers holds his body, and forcibly prevents him from expressing an opinion, or choos- ing his shoes, or making a_ protest in any way. If they would only let a fellow get in just one real horse- size kick one could —but what’s the use. In the mean- time the farrier gets in his fine work, and then it is too late. Yes, it’s a hard, cold, cruel world, so it is! Still, shoes are not so bad and they give a dandy | heft to one’s hind hoofs in arguments later on in the camps. es

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Popular Science Monthly 3 One Man Handles Col- lapsible Form REMARKABLY clever device has been placed on the market and promises to revolutionize the construc- tion of concrete box culverts, It is a collapsible metal framework in sections, which wooden casing for the con- crete. The set of forms for’ the construction of a cul- Where the ways of the little raindrops part—westward vert, thirty feet long, consists toward the Pacific, and eastward toward the Atlantic of four sections or units, which are entirely independ- Marking a Point on the Continental ent of one another. The frame, which is Dividing. Range shown in the accompanying - illustrations, is of iron, and adjustable laterally and HE big sign shown in the illustration also vertically. Two sizes are adaptable was erected by the State of New to thirty-nine different culvert. openings. Mexico to mark an in- teresting point of the continental divide. It stands near Corona, N. M., on the trans- continental highway, and attracts much at- tention from tourists traveling over that road. It marks a point of the continental wa- ter shed, and its posi- tion is such that the rainwater which falls on the -west side of the sign flows toward the Pacific Ocean, while the rainwater falling east of the sign eventu- ally reaches the Atlantic. Of course, there are in- numerable such. points along the continental divide, but only in a few sporadic cases are they marked for the benefit of tourists. If more points of interest were markedin this way it would add much to the pleasure of travel. One man can set up: and remove the forms: _ The mechanism is exceedingly simple and easily operated. The units are set up, the casing of matched boards placed over the framework and the concrete is filled in around the casing. Af- ter the concrete has hardened, a pull at the cross-bar causes the top supports to fold up, while a pull at the center bar draws in the side sills. This de- prives the wooden cas- ‘ing of its support and the boards separate from the concrete and can be removed, clean, unin- jured and ready for an- other job. Trials of the device have shown that it effects a This new collapsible, sectional concrete form great saving can be handled by one man with perfect ease in every way. - forms the support of the’ Ww

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Birds Take Their Own Picture with an Electric Shutter O take animal pictures in the open, the camera is placed where from previous observation the animal was frequently seen. If the animal in ques- tion is a bird, the camera is focused upon a nest, or a specially made bird- house or bird bath, which the bird has regularly visi- ted for at least a few days. It some- times be- comes neces- sary to hide and cover up the photog- rapher and the camera. This may easily be effected by making a frame of slats and barrel hoops, covering it with muslin or sack- A wood thrush, Turdus Mustelinus, on a limb S—_—_—_—_——S FOR PRACTICAL WORKERS a different manner, otherwise the pic- tures, having the same background, might become monotonous. But the fact remains that the animal must al- ways be outwitted in some manner, that its inherent shyness must be overcome by some trick, in order that a satisfactory picture of it may be secured upon the film or plate. Photographs of animals taken in captiv- ity never give us-a complete idea as to their habits. The person desiring to take pictures of animals in their natural en- vironment must thoroughly understand the life and habits of the animal. The simplest way to secure good pic- tures of wild animals, is to use some kind of a device with which they may take their own photographs. Pictures taken in this way are almost invariably of the first order because they give clear, sharp and distinct negatives. Secured in other ways the pictures are often blurred and indistinct in detail as well as in outline. A simple device used to take pictures of birds is shown in the illustration. With this device the birds take their own pic- tures. Birds, when flying to the ground cloth and painting the structure to re- semble either a boulder oratree-stump. This hollow structure should be large enough to accommodate the photog- rapher with his camera. A few days prior to its being used it is placed where the animals to be photographed are accustomed to come for food so that they may become accustomed-to its presence. In general it may be stated that no rules can be given governing the tak- ing of animal pictures in their natural habitat. Much must be left to chance, while the imagination and ingenuity Picture of a catbird on a post where he tripped the release operating electric shutter either for food or for a bath, first hop of the photographer must be called upon a low branch or projection over- into play to secure each picture in looking the place for which they are 761

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762 Popular Science Monthly flying, undoubtedly to spy out the land and to see that no enemies are in the vicinity. This characteristic of all birds is taken advantage of in this device. A sprig, top of a fence post, brick or stone is fastened to a short movable arm which is in control of the electric con- tacts. These con- pressed down. Another piece of metal, N, attached at O extends to within a few inches of the bottom of the box. This jg the balancer or lever arm and may be aq. justed by the movable weight P so that the slightest pressure at M at once con nects the metai J with the two poles K and L, thus closing the electric circuit. The camera jg tacts are adjusted so that the feath- ery, light body of a bird readily presses the movable arm downward thus closing the cir- placed upon a board which car. magnets. One pole of the electro-mag.- net is. connected with pole Q of the box, while the cuit which releases the shutter of the camera and the picture of the shy creature is secured. The construction of this apparatus is very simple indeed, as can readily be seen from the diagram. An empty cigar box was used for the house. This was securely fastened to a comparatively thick base. Long strips of iron, 14 in. wide and 1/16 in. thick, were used. Out of this the support A was made as shown in the illustration. This projects about 1 in. above the cigar box, a hole B was therefore bored. Two holes, C and D, situated about 14 in. above the top of the box, were drilled into the iron A. The arm E was then made. This projects 2 or 3 in. beyond the box. This arm also has two holes cor- responding to C and D. A nail is loosely passed through these holes. This forms the axle or pivot for the arm E. The arm flaps are bent together and fastened with a "Magnet ! Bell U-shaped clip at F. The arm carries a block of wood G which is fastened just be- yond the edge of the box so that it does not come into contact with it. To this block a wire H is attached which holds a piece of ‘metal (copper preferable) cut as shown. The loop J lets the metal J touch both poles, K and L, which con- sists of two brass wires 5 in. long. The branch M upon which the bird hops, is Box enclosing all the mechanism which con- trols the electric switch for making contact ye Camera Contact DOX ; Diagram showing connections for the elec- tric circuit and metal connector in the switch other is connected with one pole of the battery. The other pole of the battery is connected with pole R of the box. When the twig M is pressed down, the metal strip J makes a contact with both poles. The electro - magnet becomes magnetized, draws the iron core and releases the shutter. Since the graflex has a push button to release the shutter, an angle iron is taken; a knob is placed at one ex- tremity and adjusted so as to come into contact with the button. The other ex- tremity carries a weight which almost counterbalances the resistance of the shutter. A mien downward pressure will now release the shutter. Thispres sure is supplied by the magnet. For operation of a shutter situated in back of the lens see POPULAR SCIENCE MONTE- LY, June 1917. The camera is focused uponatwig or other object placed upon the arm E. The instant a bird hops upon the twig, current flows, the magnet is charged, and draws the angle iron downward, releasing the shut- ter. Thus the picture is taken. It will be found of great advantage to introduce a bell into the circuit so that it will in stantly ring when a contact is made and a picture secured, thus enabling the camera to be immediately brought in. ries the electro. . Holc long will « with over ‘ boar pape will | of th the | boar is ju blow imm knoc too pape to b shou ordi on: an tab tim to clo: the up] un the hat tak sul mo fac sta

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Holding a Board with the Weight of a Newspaper VERY singular experiment can be carried out with a board about 3 ft. long and a piece of paper. A newspaper will. do. The board is placed on a table with one-third of its length projecting over the edge. Cover the part of the ‘ board that is on the table with the news- paper, then ask one of your friends what will happen if you give the projecting end of the board a sharp blow downward with the fist. Most people will say that the board will spring off the table. But this is just what it will not do. Providing the blow be very sudden, the board will be immovable, no matter how hard the knock may be. The board shculd not be too wide so that a goodly portion of the paper will lay on the table top. The explanation of this curious fact is to be found in the pressure of the air. It should be borne in mind that in the ordinary way the atmosphere is pressing The board and the paper as they are placed on the table top for the experiment on every side of objects on this earth with an even weight. If the board on the table is given a sharp blow, there is no time for the air to rush beneath the paper to the underside of the board which is close to the table. As a consequence, there is a tremendous pressure on the upper part of the board, but none on the under part. This weight of air is so great that the board will break, if the blow is hard enough, before it will jump off the table. On the other hand a slow pres- sure, even with the little finger, will easily move the board. This is owing to the fact that the air has time, in these circum- stances, to pass underneath the board and newspaper—S. LEONARD BASTIN. Popular Science Monthly 763 A Homemade Wrench for Turning - Small Inaccessible Nuts HE little wrench shown in the il- lustration was made of an old foot. pump handle. The parts being round it was only necessary to drill holes through Wrench made from a foot pump rod that will work like an ordinary monkey wrench the movable jaw and the adjusting cli; then cut threads of the latter as well as ou the handle for making the wrench com- plete. Two nuts hold the adjusting piece on.the outer jaw end... This wrench is an ~ excellent one to use when making repairs on an automobile because it turns small nuts placed in places that are otherwise inaccessible-—KENNETH WHITNEY. Homemade Hectograph for Making Copies of Letters COPYING pad is indispensable to those who wish to make a limited number of copies of writings or drawings. One which is practical as well as in- expensive may be constructed in the following man- ner: Procure 1 oz. of the best gelatine; cover it well with cold water, and allow it to stand over- night, care being taken to see that all of it hes swollen. Heat 6 oz. of chemically pure glycerine over a salt water bath to a temperature not ex- ceeding 200 deg. F. The water that has not been absorbed by the gelatine should be poured off, and the gelatine added to the hot glycerine. The mixture obtained is heated for about an hour, and gently stirred occasionally, avoiding as much as possible any tendency of the fluid to froth or bubble. At this point add about a teaspoonful of oil of cloves as a preserva- The gelatine mixture placed in ashallow pan |

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764 Popular Science Monthly tive. It is now ready to pour into the vessel which is to hold it, while in use. A wooden vessel may be constructed for this purpose, but a shallow cake tin of rectangular shape will serve equally well. The container should be placed on a level surface after it has received the composi- tion, and the contenis permitted to cool in a cool room which is free from dust for about 7 hours. To use the pad it is only necessary that a small wet sponge be passed lightly over the prepared surface. When nearly dry, the first copy may be made. The writing is made in hectograph ink, which may be purchased at any stationery store. It is advisable to use a new steel pen with every original. After the writing has be- come dry, it is placed face downward on the pad, and the back of the paper rubbed gently to secure perfect contact. In a few minutes it should be removed by placing one hand on the sheet and pulling from a corner with the other. In this manner many copies can be made. When the desired copies have been obtained, the pad should be washed lightly with a sponge moistened with cold water. Lastly, be sure to let it dry before it is used again.—HERMAN NEUHAUS. A Folding Bicycle Stand for the Home Shop HIS bicycle stand not only forms a secure means for holding the ‘“‘bike”’ in position when not in use, but also has proven itself of wonderful convenience during the arduous operations of cleaning, oiling, and tire inflating. The ease with which the rear wheel and crank shaft may be rotated to reach all parts of the sprock- ets and chain while the bicycle is main- tained in its supported position, as shown in the illustration, make the device par- ticularly useful, and as the stand folds, this removes the objection which its “set-up” bulk might occasion. The details of the construction are very simple and can be readily under- stood from a study of the illustrations. The easiest and quickest way to form the three wooden parts constituting the frame is to saw them out of a %-in. board with a scroll-saw, or easier yet, on a band-saw. The angle brace connecting the base and the standard may be formed from a piece of strap iron, or if more convenient, from 44-in. round iron. When the bicyele jg placed on the stand, its weight, as shown, is supported by the upright standard; the felt-covered notch at the top, supporting Felt cushion Folding standard Brace lock pin A substantial bicycle stand that may be folded into a small space when not in use one side member of the rear wheel fork. As the bicycle hangs by one side member, the lower portion of the rear wheel swings, by gravity, against the adjacent lower edge of the standard. To guard against the bicycle being inadvertently , displaced from this position, a guard pin is provided in the base. A small stove- bolt may be used to pivotally secure the standard to the base.—J. D. GARFIELD, A Homemade Lifter for Gasoline Engine Valves HE illustration shows a lifter made of metal modeled somewhat in the shape of a carpenter’s vise. The ends of the jaws are flattened into a wedge-shape and slotted to fit over the valve stem. A forged tool in the shape of a carpen- ter’s vise for a gasoline engine valve lifter With the spring between the jaws the screw clamp ¢an be turned to compress it for removing the holding pin. Such a tool can be easily made by the home blacksmith.—_N. A. Dow. ‘

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Do You Grow Roses? Here Is a Little Information HE real secret of success in rose culture is watchful- ness. The rose, more than any other plant, has enemies which, if given a chance, prey upon it and spoil its loveliness. There- fore, eternal vigilance is the . price that must be paid for the rose garden. A long stream from a garden hose to wash off the slugs, hand-picking to re- move the chafer, frequent drenching with kerosene emul- sion or sprinkling with arsenate of lead to rid the plants of the sucking insects, aphides and thrips—all are necessary at frequent intervals if one would have roses. Such care would be too tedious were it not a labor of love. For that reason it has been said that the first requisite in preparation of a rose garden is a special love for the flowers. The sec- ond requisite is plenty of space. The rose is aristo- cratic. I+ does not like to be crowded in with mixed com- pany. Whereioses are cultivated for the sake of the cut flowers they should be planted in rows far enough apart to per- mit of cultivation with a horse-drawn And they should be cultivated plow. Popular Science Monthly Res Trimming the roses properly. A bank of memorial roses and those hardy climbers, the sweet multiflora roses Jar covering cutting to prevent evaporation and a rose pruned to an advantageous height often—not merely two or three times a‘season. Cultivation should be continued up to within a few weeks of the dormant period. Roses are propagated from seed, from hardwood cuttings, softwood cuttings, layers, bud- ding and grafting. The most common method is to use hard- wood cuttings. Good, strong, well-ripened shoots of the past summer’s growth are selected. These should be cut between the time the leaves fall and freezing weather. They should be cut into lengths of 5 or 6 in., with the upper cut just above a bud, and should be tied in bundles with raffia or with string that will not rot easily if exposed to dampness. After they have been labelled plainly they should be buried in moist sand, tops down, and placed in the cellar. If buried outside, they should be pjaced deep in the ground, below danger from frost. Where only one or two cuttings are to be rooted, an in- verted glass fruit jar may be placed over them for pro- tection. When roots have begun to grow, the plants should be permanently set in good, watered soil and shaded for a few days from the noonday sun.

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766 Popular Science Monthly A Reflex Attachment for Use on a Hand Camera N extremely simple focusing device which actually transforms the or- dinary view camera into a reflecting camera, is made from card-board or or- dinary box-boari, and is readily secured to the the back of a regu- lar cam- era for re- flex at- tachment camera by a stout rubber band, no other fastening being required. The simplest way to make this device is to make a paper box (or to have it made in a paper box factory) with the sides and ends entirely closed in, and lined with black paper. The height of the box should be about 12 in., whether for a 4 by 5, or 5 by 7 camera. The width indicated in the sectional view of the illustrations by X, should be determined by measuring the distance from the upper edge of the focusing door, when it is swung back exactly 45 deg., to the rear of the camera (the entire width of the box in this direction should be the distance X, plus about 1 in. more). The lower front portion of the box is now cut away, back to the measured distance X, asshown. Next the sight opening at the rear top edge of the box is cut out, as seen in the perspective view, and the box is ready for use. The reflecting mirror, which should be about the size of the focusing door, may be attached to the box in any suitable manner.—JULIUS D. GARFIELD. . ing to another Fastening a Breather Cap Securely to Prevent Its Loss i he breather cap on an automobile engine is very easily lost, especially when the car has been in use for a con. siderable length of time. This is due, in many cases, to the thread , on the inside of the cap wearing out and losing its holding power. To eliminate losses of this nature, remove the threads from the inside of the cap, by turning them out ona lathe. Then in- sert two headless 14-in. machine screws in the upper end of the breather pipe. Provide two slots in the cap of sufficient size to clear the two set screws. Merely drop the cap over the pipe and then turn in a horizontal direction. The two set screws entirely eliminate the pos- sibility of the cap coming loose.—ADOLPH KLEIN. Notches in cap to hold it Spreading the Air Currents from a Desk Fan HE oscillating electric fan costs al- most twice as much as the regular fan and the air currents from it are not steady and uniform, thé breeze being driven first in one direction for a_ short time, immedi- ately chang- direction. The illustration shows a new device that spreads the air quite evenly all the time. This devi — Air spreading wings sists of anum- fastened to the fan ber of metal plates, clamped together at the angle desired, and attached to the wire pro- tector in front of the fan. The plates, which are evenly spaced in a _ vertical plane, divert the air currents steadily to the parts of the room where ventilation is most needed.—J. G. PRATT. type need jam, aft o For « rig, | plic com mort set, f ecru. greg ing incré wart itie: ba type A divi twos eral the ina as if carr light mun For will light or 1 will step The war men miz: rig | wit long end radi base

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6k, Open Canoe Cruising II.—Description of the lateen rig and why it is best suited for the open canoe for cruising, sail-making, masts, etc. By E. T. bles a leg-of-mutton sail. Its ad- vantages over the leg.of mutton- type are that it requires a shorter mast, needs no mast hoops, which are prone to jam, and that the peak sets far enough aft of the mast to give good driving power. For open canoes this is the best all-around rig, as its sim- To canoe lateen, when set, resem- Keyser of 11 ft. With chalk line, join the inter- section of these circles with the ends of base line and you will have the outline of a mainsail with an area of 45 square feet. The base is the boom, the right side the yard and the left the lea leach edge of the sail. With this outline as a pattern, lay out your sail of light unbleached muslin, Tunning the plicity and compactness more than off- set,for the open cruiser, the greater driv- ing power and increased wind- ward possibil- ities of the batswing type of sail. A given area divided into two sails is pref- erable than strips parallel with the leach and allowing for a turned_ over l4-in, hem (4% in. of material) along the three edgesofthesail, and for a 1-in. strapped seam to join the stripsof muslin. Get 40-in. mus- lin and _ split each strip in two so that ee eee =a the same area in a single sail, as it allows of carrying a pretty fair spread of canvas in light weather and reducing to the mini- mum—the mizzen alone—in heavy winds. For. a 17-foot canoe, an area of 68 sq. ft. will be about right. If the skipper is very light in weight, or the canoe be of 15 or 16 ft. length, a total area of 52 sq. ft. will suit conditions better. The forward or main mast should be stepped just aft of short forward deck. The after, dandy or mizzen mast, at for- ward side of after seat. This arrange- ment calls for 14 of total sail area in mizzen and 24 in main sail. For a rig of 68 square feet, lay off on a floor with a chalk line a base line 9 ft. 3. in. long, as shown in Fig. 6. From right end of base line describe a circle with a make the best all-around radius of 10 ft. 6 in. From left end of | base line describe a circle with a radius A canoe equipped with two lateen sails, which 767 your sail will be made up of 20- ; in. widths. Pin strips together as you go along and have sail stitched and hemmed on a machine. Along the three sides of sail stitch 1-in. wide non-elastic webbing. Through this webbing, on the boom and yard edges set sheet brass washer grommets 1 ft. apart, making sure that a grommet is set in each corner of the sail, and that each grommet has a 3/16-in. eye. The dandy or mizzen sail is to be of 23 sq. ft. area and measures 6 ft. 9 in. on boom, 7 ft. 8 in. on yard, and 7 ft. 10 in. on leach. If the 52 sq. ft. rig is desired, the following dimensions should be sub- stituted: rig for an open cruiser Mainsail Dandy Lesehis: 9 ft. Gai i656 6 ft. 10 in. Marans Obrte. Ollie. «cc. cece Gckts. (Go in. Boum, 6%. Sie. ........ 5 ft. 10% in. Booms and spars should be of straight- poreenndennapEnnIp TOE

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768 - Popular Science Monthly grained pine, 1 in. in diameter at center, tapering to %4 in. at ends, and 6. in. longer than the edge of sail to which they are to be laced. This will allow for stretching of sail and for minor errors in . kK 9'3" Diagram of mainsail and mizzen of a forty- five and twenty-three square-foot sail area cutting and sewing sails to correct di- mensions. If you are a good enough mechanic to shape your spars from squared stuff, working down to an octagonal surface and then to a tapered round, very well, other- wise let a wood-working establishment shape them out from a dimensional sketch. As the masts will be short enough to be turned, they may be pro- cured from a mill made to sketch at little more cost than the squared stock. Shape the spars first, and smooth and varnish them. Three thin coats of good spar Method of lacing the seizing line through screw-eyes and grommet loops alternately varnish, well dried and smoothed down between each coat, is better than one heavy coat. A wire nail driven into ends of spars will allow varnishing them clear up to the ends without finger marks and also serve to suspend them while drying. Each yard is joined to its boom by a pair of heavy brass screw-eyes of from 34 to 1 in. inside ring diameter, screweg into forward ends of booms and spars ang connected by a heavy 11-in. brass Ting, Screw-eyes are opened to admit the Tings and then closed upon them. Capping the ends of boom and spar with % jp, brass ferrules will obviate danger of splitting. Lay one of the sails out on the floor and lay its yard and boom along its proper edges. Tie with seizing line the forward corner grommet to the connecting ring, and stretch the sails out along boom and yard, iastening them temporarily to their ends. With a soft pencil mark along boom and spar 1 in. each side of where each grommet (except corner and end grommet) comes. Set a line of brasg screw-eyes, Fig. 7, (3/16 in. inside diame- ter) along booms and spar at these marks, being careful to keep them in line, and that eyes are at right angles to length of boom or spar. Tie a loop or ring of seiz- ing line through grommet, excepting the corner end ones. Then lace a piece of seizing line alternately through these loops and the small brass screw-eyes, | Pol tke Fiag Fig.to The boom jaws, round mast plate and the flag pole plate are shown in the above sketch Figs Stretch the sail moderately taut, fasten the outer ends by their grommets to screw-eyes set out as far as possible on boom and yard, and then, fastening the lacing at one end to the forward small screw-eye, draw it taut and lash it to the rear one, leaving a foot of extra line for slacking up, which may be wound around boom or spar after the last knot is tied. You may buy boom jaws or make them yourself. In the latter event, get a piece of 14-in. half-round brass, 22 in. long, and saw it in halves. Bend and hammer each piece into the shape and dimensions shown in Fig. 8, being careful to have flat surface inside the curve. At a point % in. from end of the 3 in. arm drill and countersink fce a 3/16 in. flat-headed machine screw. The same distance from .the curve of gooseneck, drill and counter- sink for another. With two brass ma-

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= © > ee OOF SS]. aa aS SS SP ee ge eS, A ee dl chine bolts, each 114 in. long, fasten each jaw to its boom with the end of gooseneck pointing forward and its extreme end flush with boom end. Brass nuts and washers will keep the fastenings tight and Figs Fig.i2 The brass floor plate fastened to ribs and floor grating construction to strengthen it bolts should be sawed off flush with nut and filed smooth. To properly step the masts you will require two 134 in. mast plates, Fig. 9, with four 3/16 in. machine screws 34 in. long with brass nuts and washers to each mast plate, two flag pole plates, Fig. 10, with a 134 in. diameter hole. One of these will require three flat headed ma- chine screws to fit screw holes in same, and of a length equal to combined thick- ness of forward deck, flag pole plate, and nut and washer. The other flag pole plate will require machine screws 34 in. long with nuts and washers. Two pieces of 4-in. brass will also be re- quired whose dimensions will depend upon the ’ construction of the canoe. The after plate should be wide enough to ‘ extend 34 in. \ beyond the flan- Popular Science Monthly 769 ward plate should be of the shape of this board; otherwise make it a duplicate of the after plate. After getting the plates shaped, file down edges and round corners, so that they will not cut your hands or mar luggage. Then bore the after plate as shown in diagram to take eight \% in. wood screws just long enough to go through ribs without penetrating the planking, and countersink on upper side. The location of screw holes for forward plate depends upon its size and shape. Fasten one of the flag pole plates to upper side of after end of forward deck with center of hole coinciding with center line of canoe and ‘set as far forward as possible without allowing mast to jam on after edge of deck. The nuts and washers of fastenings should be under the deck. Get a piece of 14 in. oak, cherry or ma- hogany from 7 to 10 in. wide and as long as the width (front to back) of after seat. Lay second flag pole plate on one end of this plank with centre of hole coinciding with center of plank and with hinge line flush with edge of board. Mark position of screw holes of plate on plank and drill for the machine screws that fit plate, counter sinking on opposite side from plate for nuts and washers. This plank is to be screwed to under side of after seat frame with the mast plate on under side and with hole of flag hole plate in center of boat. Round-headed machine screws, with nuts and washers coming underneath the plank, are to be used as fastenings. A To hold plank in place while / it and the seat frames are bored simultaneously, a pair of clamps or even monkey wrenches may be used. Stretch a line from cen- ter of stem post A tocenter of stern ges of the mast ) post. Mark cen- plate and long enough to ex- tend from the after side of one rib to the forward side of the next. This will be found clearly illustrated in Fig. 11. If the stem piece of the canoe termi- nates in a flat triangular board, the for- A sail plan for a sixty-eight-square-foot rig with attachments placed on a seventeen-foot canoe fig ter line fore and aft on the 4 in. brass plates. Lightly fasten these floor plates in their proper places with their center lines coinciding with that of canoe. Lay the mast plates on the floor plates, flange down, and through the flag

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770 Popular Science Monthly pole plates and into the mast plates, step a couple of curtain poies. Keeping the center of the mast plates on the center line of canoe, move them forward and backward until both masts have a pleas- ing and identical rake, when the position of the mast plates and their screw holes may be marked on the floor plates. \ Figi4 Figis The shape of the blanche cleat and the clutch cleat for mizzen sheet both in brass After drilling for these, countersink on the under side of floor plates. This permits the removal of mast plates without taking up floor plates as the nuts and washers will be on upper side. The floor grating should be cut away as in Fig. 12 if it interferes with the in- stallation of floor plates. Dotted lines under the floor plates indicate portions of two grating strips in way of floor plate. Broken lines along ends of plate show how these, when sawed away niay be utilized as cross braces to keep the ends of short- ened strips in place. When all steps are permanently fast- ened, re-step the curtain poles. Near lower end of foreward one, and just high enough to keep from marring the deck, tie a brass pulley block with a 3%-in. sheave. Tie another near the mast head so that you can hoist the mainsail as shown in Fig. 18. The governing conditions are that the forward end of boom must not foul forward deck and that the after end of boom must clear head of passenger seated beneath it. The mizzen should be at same height above floor at jaw as the mainsail, boom should have same lift and should clear after deck. Manipulate both sails until these conditions are met. Then mark on the yards the position of halliards and on the masts the positions of upper blocks, and mast plates. These dimensions give you data for your mast specifications. From butt of curtain poles to 6 in. above upper blocks will be length of mast. From floor to flag pole plates they should be cylindrical and 134 in. in diameter. From flag pole plates to mast head they must taper to 11% in, diameter. Instead of upper block on mizzen mast, a sheave set in a mortise will be an improvement. Let sheave be 1)gin. diameter and 3 in. thick. . Mortige to take this should be 2 in. long and 1 in, wide and its center one inch above place already marked for block. When masts are finished, set the halliard blocks with brass screw-eyeg which have been opened and closed over the eyes on blocks. Put around each mast, 1 in. above and below each jaw, a leather collar 14 in. thick and 1 in. wide, attached with copper tacks. Soak in water to make pliable before attaching and shellac after they have dried. These collars prevent sails from hoisting too high or booms falling on decks when low- ered. To keep mizzen out of the water when lowered, run an endless line through a screw-eye on masthead and through another one on boom as shown in Fig. 18. Use % in. clothes line for halliards and sheets and let main sheet run through a ring on boom and fasten with a snap to a ring lashed to center of thwart. When close hauled, this gives a double purchase and when cast off in running ahead of wind doubles the length of sheet. The mizzen sheet passes through a screw-eye on after deck, as shown in Fig. 13, to a clutch cleat, Fig. 14, placed within reach of the skipper’s left hand. To belay halliards, two blanche cleats, Fig. 15, are attached to right hand in-wale within reach of the right hand. That for the mainsail has the hook set aft, and that -for the mizzen has the hook forward. (To be continued) Freezing a Glass Tumbler to a Block of Wood ELECT a small, planed block of hard wood and place upon it a few drops of water and then a glass tumbler having a smooth bottom. Pour about 1 in. of water into the tumbler and add powdered ammonium nitrate, stirring the mixture constantly. As the ammonium nitrate goes into solution, it absorbs heat, pro- ducing a low temperature which quickly freezes the tumbler fast to the block, so that the latter will not fall when the tumbler is lifted from the table. Frost also gathers on the outside of the tumbler. —a— oa et = oH 1 se 2 OOO ee ee ee ee ee ee ee ee ee eS ee ee Tr be fee > zt tee 2

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ITES and airplanes are associated kK in the mind of the present-day boy. The former came down to us from great antiquity; but the flying machine, as we know it, is of such recent origin that the wonder due to its performances has not yet abated. It is singular that the one great weakness in airplanes is lack of control—the inability to stabilize the floating de- vice. That has always been the difficulty with kites. The box-kite is not an old invention. That and the Malay kite have no tails, but possess inherent stability. The development of the air- plane has brought out a stabilizer—the well-known gyroscope, which, when set in motion, objects to a change in the plane of its rotation. This device is now applied to a kite in such a manner as to give it a steady motion and to add wonder- fully to its attractiveness when in flight. The outline of the kite ap- proaches the ordinary air- plane structure. The gyro- scopic wheel is at the forward end of the main plane, mounted on a horizontal axis, so that it rotates on a vertical fore and aft plane, giving an air of vitality to the kite, and making it ap- 7 J.S.Zerbe pear as though the wheel actually propels or sustains the kite in its flight through the air. The frame is made of a pair of pine strips, each 4 ft. long, of straight clear: pine, 4% by 1% in. in thickness. These are secured to- gether at their rear ends and their forward ends. They are held in permanent alinement by a cross strip, also 4 ft. long, of the same material and dimensions, this strip being located 16 in. from the forward ends of the parallel strips. At the crossing points the pieces CROSS WIRE AT END OF FRAME GYROSCOPE WHEEL Rh. _._/SYROSCOPE WING AR bacdioge dT RIM sor Yi FLYING CORD STRIPS TWISTED SPOKE Vy, i i) MAIN FRAME STRIP CONNECT Bicol eee = oe CORD HOLDER 2 a. METHOD OF AD- JUSTING CORD A wheel is interposed between the front ends of the main frame; the wind gives it speed for gyroscopic action are provided with shallow gains, so they will fit together snugly, and are then se- cured by means of small wire nails and wrapped with a strong fine cord. 771 separated 5 in. from each other. at.

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772 A thin, stiff, steel wire, not exceeding No. 20 gage, 6 ft. in length, is threaded through holes in the forward ends of the main parallel strips, and bent back at their outer ends so they meet the extremities of the cross strip. The detailed section of. the drawing shows how the wire and strip are secured together by the two right- angled bends, the end limb of the wire resting in a groove and the short bent part of the wire adapted to enter a hole, after which the two parts are wrapped with a thin cord. The fish-tail has at its margins a wire, properly bent and attached to the parallel strips and cross strip, thereby forming the entire frame ready to receive the covering. This may be of silk, glazed cotton, or paper, preferably waterproofed. This should be applied on both sides, or silk on the lower side and water-proof paper on the upper side, thereby making a neat and durable job. Every part of the frame- work is covered except that portion be- tween the parallel bars forward of the cross strip. Before the wire at the front part of the frame is placed into position, the gyro- scope wheel must be put on the wire. The wheel is made as follows: A ring of heavy wire (No. 12 gage will answer) is bent into form, and held at the abutting ends by a tin tube. This ring should be not less than 20 in. in diameter, the object being to make the wheel with considerable weight at the perimeter, to give a proper gyroscopic effect. A common spool is used for the hub. This should have a wooden tube through the axial bore, provided with a hole large enough to permit the spool to rotate freely on the wire. A pair of cross holes is bored through each end of the spool to receive wires. On each of the four sides these wires are brought together in pairs, and twisted to form spokes, the outer ends of these twisted spokes being wrapped around the ring and their ends permitted to project out a distance of 3 in. and so disposed that they form V-shaped arms. Triangularly-formed pieces of fabric or paper are then attached to these arms, and folded around the twisted portions of the spokes, to form open V-shaped grooves. When the wheel is in position, the open parts of the grooves or wings thus pro- vided, are so disposed that the wind will Popular Science Monthly drive the wheel in the direction that the kite moves, the upper part of the whee] moving forward. This action of the whee] not only steadies the kite but has a greater or less tendency to draw down the forward end of the kite, which permits of the flying cord being placed behind the wheel. The flying cord is attached to the cross strip behind the wheel, two points of attachment being necessary, about 10 in, apart. This cord is merely a loop, which hangs down 1 ft. or more. To this loop the main cord is fixed. As it is necessary to provide a means for adjusting the cord so that the proper angle may be given to the kite, a pair of wire arms, each 20 in, long, are secured at their rear ends to the tail of the kite, the forward ends terminat- ing at a point below the rear cross strip of the kite. Each wire arm has a hook, or return bend, so that the looped cord may be wrapped around and secured to the hook at such a point as to give a greater or less distance between the cross strip and the hook, to enable the flyer to give a greater or less angle to the kite, The nearer the hook is to the body of the kite the flatter will be its angle in flight, and by this provision the kite is adapted to be adjusted for a wind of any velocity, A Fine-Toothed Rake With Detach- able Tooth-Holder INDING the ordinary garden rake too coarse to use among the plants just appearing, I made a rake and used it Fastening ao ls Or screws a Wire nails The construction of a garden rake head in which nails are used for the teeth where I could not handle a larger rake. The illustration clearly shows the whole construction. Wire nails placed as far apart assuitable. The tooth-holding sec- tion should have the tooth-holes bored out to prevent splitting when the teeth are driven in. By having tooth-holders equipped with teeth of different sizes and set at various distances apart a combina- tion rake is obtained.— JAMES M. KANE. QO ne a=a~x~ —_—— s. j~, Ste pe

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Cabbage Root Maggots and How to Control Them ABBAGE and related crops frequent- ly suffer severe injury from the cab- bage maggot. Young plants are most seriously affected, the maggots eroding the outer surface and boring into the interior The cabbage maggot. A, female fly; B, head of male; C, maggot; D, anal end; E, puparium of the roots, devouring the tender rootlets and frequently penetrating the lower portion of the stalk. This insect, also known as the radish maggot, is an imported pest, and it does very serious injury throughout the North- ern States and Canada, attacking all forms of crucifers, whether wild or culti- vated. In the above-mentioned region it is the cause of more or less loss to the crops year after year, but, as with other destructive insects, it is much more abundant in some seasons than in others. Since this species also is a root feeder, the remedies prescribed by the U.S. States Department of Agriculture for the seed corn maggot are applicable. In addition there are certain preventive and other measures for its destruction that have been found successful, their use being justified by the value of the plants. To be thoroughly effective these meth- ods should be employed before the in- sect’s eggs are laid. A common method for deterring the parent flies from de- positing their eggs consists in placing sand soaked in kerosene—a cupful to a bucket of dry sand—at the base of the plants, along the rows. This mixture will also kill young maggots that might attempt to work through it. When the maggot attacks radish, or other plants than the cabbage and the cauliflower, prepare 2, solution as follows Popular Science Monthly 713 and apply around the stalk of the plants affected. Add to 1 lb. of soap boiled in 1 gal. of water, 14 gal. of crude carbolic acid and dilute the whole with 35 parts of water. It is best to use this mixture a day or two after the plants are up or transplanted, and repeat every week or ten days until about the third week in May, after which there is less danger. Although laborious, hand picking has the merit of being effective, and is prac- ticed with considerable success by ex- tensive cabbage growers, but it is not practicable with radish and similar crops. It consists in pulling up the young plants, examining the roots for eggs and maggots and crushing with the hand or by washing the roots in a strong solution of soap and then replanting. By looking closely, the minute white eggs may be seen about the stalks of the young cabbages, and if the earth is raked away so as to expose the eggs to the sun they will dry up, thus preventing the maggots from hatching. Afterwards the plants should be hilled. In most cases the plants will show no evil effects from this treatment after two or three weeks have elapsed. ; Cutting a Heater Pipe with a Can Opener HILE replacing some hot air heater pipe a householder found it neces- sary to cut off part of a section: Lacking Method of applying a can opener to the metal for cutting around a heater pipe a pair of tinner’s shears, he used an ordinary can-opener in the manner shown. The starting cut was made with a chisel. The can opener, while cutting, also produced a nice, uniform flare, very con- venient for the insertion of the end of another section.— JAMES M. KANE. ai te CA me NEE

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774 Popular Science Monthly The Color of Gasoline Does Not Denote Its Quality T one time the refineries turned out yellow kerosene and gasoline and the methods used made the liquid some- what dangerous. For this reason, the publi¢c demanded a pure white gasoline. But the new cracking process produces a perfectly safe gasoline which has a slight yellowish tinge. Converting a Porch Swing Intoa Baby’s Bed PORCH swing can be easily con- verted into a cool, as well as a safe bed for the baby by attaching a swinging apron to the edge of the seat. The apron Vg Le ; € a \ he} So) d CZ o\\ ant Y GUZEN ne . 4 pe oe “i A A frame covered with wire screen to raise over the seat opening for making a baby’s bed consists of a frame made the same size as the opening between the two arms of the swing and covered with wire screen. The frame is hinged to the front edge of the seat so that it can be swung up and fastened with hooks and eyes to the out- side of the arm. Another hook can be attached to the under side of the seat and an eye fastened into the frame so that it may be used to keep the-frame from striking the legs of the occupant when the bed is re-converted into a swing.—J, A, FITZPATRICK. Making a Lawn Leveling Tamper of Wood O make a handy tamper for leveling lawns, paths, etc., first procure a 12-ft. piece of 2 by 4-in. scantling, and a section of planking about 10 by 12 in. in size. From the seantling cut four pieces each about 10 in. long, four pieces about 12 in. long and one piece about 4 ft. long. This last piece should have one end whittled down into a rounded handle. The method of con- structing the tamper can be best under- stood by referring to the drawing, which shows the eight short pieces of scantling nailed together in the form of a “crib” with the 4-ft. piece in the center as a handle and the section of planking nailed to the bottom to make a smooth surface. Ob- viously scraps and odd pieces of scantling of the proper size can be used in place of the 12-ft. piece. Also the number of short pieces can be varied to obtain the weight that is desired.— FRANK L. MATTES. Tamper made of wood pieces Removing Yellow Stains from Piano Keys IANO keys, by use, will turn yellow. To restore the original whiteness, put 1 oz. of nitric acid in 12 oz. of soft water (pour the acid slowly into the water—do not reverse this or the acid will fly up into your eyes) and apply the liquid to the ivory with a brush, taking care that no acid gets on the woodwork. WaslPoff the acid with a piece of flannel dipped in clean water and wipe with a dry cloth. Besides restoring piano keys, this same mixture is equally efficacious for cleaning the handles of cutlery and other similar articles. : a se ei eet le eee. eee eee ee el

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Simple Designs for Sheet Metal Working XII.—Interesting pattern problems developed by means of radial lines By Arthur F. Payne Director of Vocational Education, Johnstown, Pa. developed was the pattern for the hole in the shield of a hopper. The illus- tration Fig. 1 shows the method of de- veloping the shield for a ‘‘jack pipe” or bath room ventilator pipe coming through a roof, (in the illustration the roof is drawn very small). The method used is exactly the same as for the hopper, but as the hopper was developed by radial lines and this jack pipe is developed by use of parallel lines, it will make it much easier and make a good review of the method if we briefly outline the steps of the development. First, draw the side view A, Fig. 1, obtaining the angle of the shield from the pitch of the roof as described in the last issue. Second, draw the bottom view B. Third, project the lines from the points on [’ the last issue, one of the problem: Pattern for handle Pattern hole, also that if we can get the correct widths on these lines we shall have the pattern of the hole. To get these correct widths we must draw the front view G, which is done as follows: Fifth, draw the pipe and the bottom view being careful to note that the numbers are turned a quarter turn to the left, number one being in front instead of on the right side. Sixth, project the lines up from the bot- tom view until they cross the same numbered lines coming over from the side view. Mark these points with a cross. Connect these crosses with a curve and Apex Pattern P for 5 handle boss. ‘ 6 4 Maney ' Sts 2* Ix 6 Tae ht i fs ve . H \ , | Ya Lip pattern asa s & "” . 2 on va Pate’ A 9 ; 6 Fig.! aes Ee Fig.2 8 c 2 Developing a pattern to make a shield for a jack 7 | 3 pipe and also a pattern for making a liquid measure 65 * the bottom view circle upward until they meet the shield line C-D. Fourth, pro- ject lines out exactly at right angles to the shield line C-D. Draw the center line E-F Now it will easily be seen that these lines give us the length of the 775 we will have a correct view of the front view of the joint of the pipe and the shield. The upper part of the joint is drawn in dotted lines because it is back of the pipe and cannot be seen. Seventh, with a pair of compasses measure the

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776 Popular Science Monthly different widths and place them on the same numbered lines on the pattern. Mark with a cross and then connect these crosses with a curve and you will have the pattern for the hole. The next problem, Fig. 2, that of the measure, gives us four patterns to de- velop, all of which are very interesting. The drawing appears somewhat compli- cated on account of overlapping lines, but if you will follow the directions care- fully you will have no difficulty. Government Proportions for Graduating Liquid Measures Before we develop the patterns it might be well to know the U.S. Government proportions for liquid measures. No matter what thesize of the measure, the diameter of the bottom must equal

90 8) 4» _ ¢3 4 L —_— ” 36 7 K 18 9 _ meneame o 9 Protractor 2 3 two-thirds of the vertical height, the di- ameter of the.top must equal two-thirds of the diameter of the bottom. LIQUID MEASURES Sizes in inches Size Height Diameter Diameter Base Top 1 gallon 9.80 6.53 4.35 ¥% “ 7.78 5.18 3.45 1 quart 6.17 4.11 2.74 1 pint 4.90 $3.27 2.18 % pint 3.89 2.59 1.73 1 gill 3.09 2.06 1.37 FLARING PAILS Size Height Diameter Diameter Base Top 2quarts 4 inches 44% inches 614 inches «“ Va 10 quarts 8 ae ‘i uy “* 14 quarts 9 >: - 13 1“ No matter what the size the method of developing the patterns is exactly the same The method used in Fig. 2 igs ag follows: To develop the pattern for the body of the measure. First, draw the front view A, the correct size and pro- pertion, continue the side lines up to the apex B and draw the one-half bottom view C. Second, with the dividers strike the pattern arc D-E getting the correct length by stepping the eight spaces of the bottom view. Third, strike the are F-¢ and the one-half pattern will be complete, This series has been running long enough now for those of you who have worked out all the problems to be ready to adopt “‘short cuts’’ and quick methods, The use of the one-half bottom view and the development of the one-half pattern '‘ are simple “short cuts,’”’ others will be ® demonstrated later, Patterns

A pattern development for a ninety-degree tapered elbow of any number of pieces To develop the pattern for the lip which is merely part of a cone, the apex of which is at H: First, draw the outline of the lip, then draw the complete cone of which it is a part by continuing the side lines. Second, draw the one-half bottom view J. Divide it into eight equal spaces. Project these points to the base line, then to the apex H, where these lines cross the outline of the lip. Draw lines straight over to the side line to get the true lengths as you have done before on previous problems. Third, draw the pattern are K-L, getting the correct length by laying off the eight spaces from the bottom view. Draw lines from these oints to the apex H. Now swing the lines over from the side line until they cross the same numbered line coming up from the are K-L. Make a cross where the lines cross, connect with a curve, draw the arc for the lip to join on to the body and the one-half pattern for the lip is complete.

—_ mt B® 4 2.6 — Oe DD SD” TP an a sat Gee feet ae a ae

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The ‘‘boss” on the inside of the handle is part of a cylinder so it must be devel- oped by parallel lines just as we developed the elbows and tees in previous issues. In this pattern we use the same prin- ciples as in Fig. 1. First, from the front view project lines upward and draw the section view M, obtaining the width from the other view of the handle marked N. Second, divide the section circle of the boss into four parts. Project -points 2 and 4 down to the front view of the boss. From where these lines cross the handle, draw lines at right angles. Draw the line O-P. Now we have the true length of the pattern. We can get the true widths from the sections view, measuring off four of the section spaces on line 1-5 on the pattern and two on line 2-4 of the pattern, do the same with the lower half, connect these points with a curved line and the pattern for the handle boss is complete. The pattern for the handle is a new ap- plication of some previously demonstrated principles in parallel lines. First draw the view N. Second, divide the outline of the handle into any number of spaces as shown by the crosses. Project these points across to view N. Number them asshown. Third, draw the center line of the pattern, get the correct length by measuring with compasses the spaces on the outline of the handle and transferring them to the center line of the pattern. Be sure to give each point the same num- ber on the pattern as it has on the other views. Fourth, project lines up to the pattern from the points on the N view of the handle. Make crosses where these lines cross the same numbered line on the pattern. Join the crosses with a free hand curve and the pattern for the handle will be complete. A simple problem that is often con- fusing to the ordinary sheet metal worker is illustrated by Fig. 3. The problem is that of developing the patterns for a ninety-degree tapered elbow of any num- ber of pieces. This elbow has six pieces and the small diameter is one-third that of the large diameter. These patterns may also be used for a ship’s ventilator, although this type of ventilator should not be confused with the regular oval ventilator which is developed by ‘“‘tri- angulation.” This method will be ex- plained later in the series. Popular Science Monthly 777 Each section of the tapered elbow is part of a cone as can be seen in drawing L. To develop the patterns: First, draw a cone, the base of which is equal to the diameter of the large end of the elbow. Second, on the upper part of the cone draw the line for the small diameter of the elbow. The altitude of the cone may be varied to suit the length of elbow re- quired. Third, we must now obtain the miter lines. This is done in exactly the same manner as explained in the October 1917 issue for ninety degree cylindrical elbows. The rule given there is: ‘In all elbows of more than two pieces, the two end sections should be one-half the size of the other sections.” In this case, 123456786 3 A pattern for another type of a ninety- degree reducer elbow used for a ventilator there are six sections to the elbow so the four middle sections will each have twice the number of angles in it as the end section. This is shown in drawing K which illustrates the use of a “protractor” which is a small brass ‘“‘angle measure” and can be bought for 25 cents. The crosses indicate the miter lines. Note that the two end sections have only 9 deg. each, while the middle sections have 18 deg. each. Take the diameter of the cone base and lay it off as N-O on the drawing K. This will give the exact shape of section A on the cone. Lay this off as section A on the cone. Take the distance on the center line of section A and set off the same distance on the center line for section F, then divide the remainder of the center line into four equal spaces. Draw the miter lines at an angle of 9 deg. to the line M which is

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778 Popular Science Monthly drawn at right angles to the center line, starting at the four equal division points. Develop the pattern for these sections in the usual manner, using “radial lines’’ as described before. Briefly the steps are: Draw the one-half bottom view, divide into four equal parts, project lines from these points to base lines then to apex, strike arc for pattern, get correct length by stepping off eight spaces from bottom view, from where the lines from the base to the apex cross the miter lines, draw lines at right angles over to side of cone to get the true lengths, swing these points over to the pattern until they cross the same numbered lines on the pattern, make a cross where these lines cross, connect crosses with free hand curves, and pattern will be complete. The drawing H shows ‘the proportions of the finished elbow. The, illustration Fig. 4 shows another 90-deg. reducer elbow, which is often used for a ventilator. The details of this de- velopment will not be given as they have already been explained many times in this series. The reason for giving this problem was to illustrate a new and in- teresting method. When drawing this reducer, great care must be taken to have the joint at 45 deg. to the center line of the pipe and of the cone. To do this, draw a circle equal to the diameter of the pipe and then draw the cone so that both its outside lines are tangent to the circle as shown in the drawing. This will bring the outside lines of both cone and pipe just touching the circle, as shown in the drawing. The pattern for the pipe is developed by means of parallel lines, the pattern for the cone by means of radial lines. Do Not Use Fuel Savers. Regulate Your Dampers Instead N old fireman says, ‘“Not one person in ten operates the draughts of his furnace properly or handles his coal to good advantage.” It will be found that the coal savers, of which there are many, are accompanied with a set of rules, which, if observed, without using the saver, would go a long way toward conserving fuel. Do not spend money on these chemical compounds. The most sensible practice is to sprinkle the coal with water before throwing it upon the fire. Bracing for Belt Guard to Cover. Floor Countershaft BELT guard frame to cover a floor countershaft was built of pipe and fittings, with wire cloth stretched over them. This caused the two parts to be Staple clip or yoke 3" mesh Se wire screen (se a __a@ Flat a brace A guard frame of pipe and fittings placed over a countershaft attached to the floor pulled together at the top. The braces to hold the upper parts at the right distance from one another were made of flat iron, 134 in. wide and 3¢ in. thick with U-bolts. to clamp around the pipes. This method of guarding belts is excellent as it affords a clear view of the machines, while the flanges permit the whole frame to be unbolted and un- screened quickly when necessary.—JAMES M. KANE. Carrots Used as a Substitute for Eggs in Puddings N these days of high prices, anything that can be used as a substitute, and give good results at the same time, will be a welcome addition in helping to keep down the high cost of living. Boiled carrots, when properly treated, form an excellent substitute for eggs in puddings, ete. Boil the carrots until they are tender and nearly ready to fall apart; drain care- fully, and mash and press through a coarse cloth or strainer. The pulp is then introduced among the other ingredients of the pudding and the eggs totally omitted. Puddings made in this manner are lighter than where eggs are used, and are more palatable. The carrots also impart a fine yellow color to the pudding so that nobody can tell whether eggs were used or not. oma wa et Oo ft — = a cf a

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Here Is a Combination Fence and Lawn Sprinkler RON pipe % in. in diameter is exten- I sively used for protecting the small grass spots between the sidewalk and the street curb, also between the sidewalk and the building, pro- viding the space is not large. These plots are very diffi- cult to keep water- ed in dry seasons. Oneresident owner made a combina- tion fence, using ‘the pipe for the sprinkling ap- paratus as well as Popular Science Monthly LIEAL, 779 against the glass, the globe appears to be full of ink. This is exhibited to the audience, and to prove the genuineness of the fluid, the performer takes a ladle and dipping it into the bowl, pours out some of the ink into a plate, which is sent around. The ladle is made with a hollow handle which has a small holeat the bottom, leading into the bowl of the ladle. Another small puncture is made within 1 in. of the top of the handle. Before commenc- ing the trick, ink PZEELZ TS A Se for the guard. Small holes were drilled in a row on the inside surface of the pipe and the whole line was connected with the water supply. In [s:$ building such a2 protection be sure [2 to have all joints watertight and the tees plugged that are used to con- nect the iron sup- ports for the posts. —THOMAS W. BENSON. Changing Ink Into Water. Black Magic HE performer introduces to the audi- ence a glass or bowl of ink which is covered over for an instant by a lady’s handkerchief, during which time it be- comes changed to clear water. This trick ean be performed with any sized glass from a miniature tumbler up to a large fish globe. The fish globe will be described here, as it differs but little from the small- er sized glasses. There is made to fit inside of the globe a lining of alpaca, or black silk without any bottom, and around the top of which runs a wire over which the alpaca is turned to prevent it from falling down. The lining is made to fit the glass as closely as possible. When the water is pa bed — = ——— — This Is poured in and presses the cloth out PRET = = ase i s Thy 7 " ASS , | ———- > — The pipe guarding the grass plot is used for sprinkling the ground in a dry season is poured into the ladle bowl, which, when the ladle is tilted, runs up in- to the handle, but is prevented from flowing back again by a finger or thumb placed over and covering the top hole. The ladle can, there- fore, be held in any position with- out fear of the hidden liquid coming out. When it is dipped -in the globe it is not allowed to enter the water, but is only lowered to the surface, the finger at the same time being removed from the hole in the handle, allow- ing the ink to flow down and into the bowl of the ladle, from which it is then poured into a plate and handed out for examina- tion. The former next borrows alarge hand- kerchief with which to cover the bowl and touching the glass with his wand com- mands the ink to vanish. When the cov- ering is lifted the bowl will be found full of clear water, with gold fish swimming in it. In snatching off the handkerchief the wire ring is grasped and whipped off under cover and dropped into an open drawer at the rear of the table. This trick is extremely effective when adroitly done, as the transition seems so obvious because of the sample handed around in the ladle. The magician should not forget to “patter” while doing the trick. NNN AAI cnn | (Cc — (( | Se eS = ———— =

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780 Arrangement of a Stenographer’s Desk for Accessibility FTER receiving a large number of suggestions from various customers a typewriter firm has worked out an efficient and handy arrangement for a iM Wil typewriter desk in which all of the various letter and bill heads as well as other supplies may be kept within reach of the stenographer. All of the drawers are intended to be open when the stenogra- MMM 8 7 6 S 4 3 2 1 -VvVW LUON OD MMMM UM dae The left drawer has compartments for finished work, letters to be answered and other papers pher is at work, the general movement being from right to left. The upper right drawer has compart- ments which are used as follows: sheets for carbon copies, 1; thin white paper for UML, Popular Science Monthly additional copies, 2; inter-office letter heads, 3; general correspondence letter heads, 4; heavy white paper for long memorandas and second sheets, 5; folder of carbon paper, 6; special letter heads, 7; and telegram blanks, 8. The lower right drawer consists of ULL The arrangement of the upper right and lower left drawer to the desk for keeping the various kinds of paper used in correspondence, envelopes, pins, clips and the pencils compartments 1 for No. 6 and 10 en velopes; 2 for inter-department messenger slips, inclosure slips and a pyramid of pins; 3 is for erasers, clips and rubber bands; 4 is for well-sharpened pencils and 5 for No. 6 and 9 envelopes and note books. The left drawer has compart- ments, 1, finish work; 2, letters to be answered and other papers being used in connection with work; 3, carbon copies, and 4, miscellaneous supplies and forms, personal belongings, cleaning outfit and dust cloth. Do You Want Your Tires to Last? Then F‘!l Up the Cuts HE service of tires will be abbreviated to a considerable extent, if cuts, punctures, and snags are neglected. Too much care cannot be exercised in avoiding injuries of this naturé as much as possible or, at least, in giving them the proper at- tention within a reasonable period. New macadam roads, especially when wet, are liable to damage rubber covers. It is recommended that the speed of the car be slightly accelorated and the clutch depressed before coming up to loose, crushed stone in the road. ye cu it~ ait, Sy he i a: i ee es ee “a as ee es i ee ‘a ee es Ge ess ce ee ee ee ee eee

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T vo necessary power to drive small machin- ery inthe repair shop may be obtained by the use of a wind- motor asshown. Such a motor may also be used to operate pumps and electric genera- tors for charging stor- age batteries. The device is easy to con- struct and is inex- pensive, the material being obtained from any hardware store. The driving connec- tions, such as_ the beveled gears and The manner of mounting the wings of hangers may be ob- the wind motor on the roof of the shop tained from old, dis- carded machinery. piece of 114-in. pipe will serve for the main shaft, the length depending on the position in which the motor is set in the roof; the buckets, how- ever, should be at least 4 ft. above the roof to obtain the best results. One method of transmitting the power from the motor is shown in Fig. 1. However, the builder may choose any meth- od that will bet- ter suit his pur- pose. The object of the drawings is to show the con- struction of the motor and in- ( : stallation of the buckets at the proper angles, as shown in Fig. 2. The construc- tion of the cross-arms may be readily un- derstood from the il- lustration. The meth- od of fastening the ‘buckets to the arms is shown in Fig. 3, using plates, Fig. 4, on the inside of the buckets. The pat- tern for the sheet- iron to form the buckets is shown in Fig. 5. Mark out the sheet as indicated by dotted lines and then cut it out, which will allow for a %-in. lap. An old mowing ma- Nextshape the sheet asshown in Fig. 6, and chine will furnish the bevel gears. A punch the hole to receive 14-in. bolts. The Fig 4 a of bucket $"Hole in cap 3" Pipe f Bearing Fig) Belt buckets are then bolted to the cross- arms, using the Gia plates, Fig. 4, on latetotit inside) the inside. The cross arms and buckets are now complete. The bearing to receive the main shaft is made of a piece of pipe 3 in. in diameter with both ends threaded to re- ceive ordinary pipe caps. Drill holes 134 in. in the cen- ter of the caps, to receive the shaft. The com- pleted bearing is fastened to one of the rafters as Details of the wings and the method of forming the buckets and the bevel gear 781 shown in Fig. 1. The shaft is run

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782 Popular Science Monthly through the bearing, collars being used to hold it in place. The cross-arm is bolted at the end of the shaft, care being taken to screw the nuts up tightly so that the arm will not slip on the shaft. The bevel gears and pulley may be fitted, using an ordinary shaft hanger next to the gear. The other bearing may be made by using a pipe nipple filled with babbitt metal and bored to fit the shaft. It is then fastened with screws to a rafter. The dimensions given are for a motor of small power, but they may be increased proportionately for a higher powered motor. The motor will always revolve in the same direction, no matter from which point the wind may be. Making an Adding and Subtracting Machine of Cardboard F our brains performed arithmetical labors. in the same way that calculating machines do their work we should cer- tainly have wheels in our heads, for cir- cular motion is the basis of every practical calculating device. Since our system of numbers has ten for a basis almost all the engaging wheels of computing ma- chines have teeth that are ten or a multiple of ten in number for convenience. The first step in the construction of the adding machine here- in described is to divide the circumference of a circle into ten equal parts. There are scientific ways of doing it, but trial measurements with a pair of dividersonthe circumference will soon pro- Numbered cardboard wheels duce a close for the adding machine @PProxima- tion. To con- struct the machine you will need a smooth board 5 in. long, 4 in. wide and 1% in. thick; some heavy cardboard—the stouter the better—for the two number wheels; two flat-headed wire brads for axles and a wire nail about 114 in. in length, " To make the lower wheel of the ma. chine draw a circle on the cardboard 2 ip, in diameter, then draw two tangents that meet at a point beyond the cirele, Divide the circumference into ten equal parts and number in black ink the divisign points as shown. Following the lines of the tangents with scissors cut out the pear-shaped figure, and with a sharp knife make a small triangular opening in the V-shaped projection. The other wheel of the machine is algo 2 in. in diameter and the circumference is divided into ten equal parts. Describe a concentric circle about 14 in. inside of the outer circumference, then carefully cut the teeth as shown. To do this with precision you should also divide the inner circle into ten equal points and make marks midway between the division marks of the outer circle. Using these marks for guides you will have no diffi. culty in cutting the teeth accurately. Number the second wheel in ink from 0 to9 inclusive—a number on each tooth, The machine is now ready to set up: Fasten the cogwheel first. Place it on the board in such a position that the teeth do not overlap the upper edge and fasten it by one of the brads driven through the center, drawing it well down against the pasteboard, but not too tight to prevent it from turning easily. With a pin for a temporary axle, de- termine the proper position for the lower wheel. It should be such that when the wheel is turned’ the projecting point shall engage the teeth of the upper wheel, but will permit them to pass without cramp- ing. When the position is correct, drive a brad through the center to make all parts secure. Mark the board with the numbers shown. Use a soft pencil and be guided by the numbers on the lower wheel. Draw a pencil guide line between the two wheels so that it will appear through the triangular opening. In addition the small arrows, one on the point of the lower wheel and the other on the cog number 9 of the upper wheel are drawn. Make deep indentations on the lower wheel on the inside of each of the num- bers with a rather dull knife. These serve as a holding place for the point — @® @8 od

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of the large wire nail that acts as a sort of a movable handle. The machine is set when the points of the arrows are exactly opposite. The lower wheel always turns from left to right. It is now ready for adding a column of figures. Take the figures 8, 9, 6, 9, 8, 7, 7, 9, 3 and 2 and add them. Insert the point of the wire nail in the indentation of the lower wheel opposite the number 8 of the board. Pay no attention to the numbers on the wheel until you finish adding. Turn the lower figure wheel with the nail until the point is opposite the guide line. Lift the nail and place the point in the indentation at number 9 of the poard and turn the wheel until the nail is opposite the guide line. Again lift the nail, insert the point opposite the number 6 of the board and turn the wheel until the nail is once more opposite the guide line. Add the other figure in the same way. The sum total of the column will appear at the opposite ends of the guide lines, namely, 68. The capacity of the machine is 100, but by keeping tally of how many times the cog number 9 passes the guide line, you can use the machine for any column of figures. This machine is also a sub- tracting machine. set the upper wheel so that the first digit of the minuend appears at the guide line, and then set the lower wheel so that the second digit of the minuend also appears at the guide line. Now place the nail opposite the subtrahend marked on the board and move the lower wheel clockwise—in the opposite direction to that indicated by the arrow —the number of spaces equal to the sub- trahend. As in addition, the result ap- pears at the guide lines. When there are two digits in the subtrahend place the nail in the hole opposite the digit on the board and, as in the first case, turn the wheel a number of spaces equal to the subtrahend. The subtracting numbers of one digit, the zero mark on the upper, or tens, wheel must be set on the guide line, since the tens place is not represented in the minuend. This machine is not difficult to make, and it will be found very convenient by anyone who does much figuring but not enough to warrant the purchase of a machine.—E. P. THORNTON. Popular Science Monthly To subtract with it, - 783 A Simple Sawdust Deflector for a Circular Saw Bench i do away with the confusing spray of dust which a circular saw throws up, particularly when cutting heavy lumber, a wheelwright made the ad- justable sawdust deflector, shown in the 7g ELECTRIC LIGHT & | CORD DEFLECTOR SAW TABLE The parts for making an overhanging sawdust deflector for a circular saw table illustration, to cover his circular saw. A length of narrow tire steel was bolted to an overhead beam and bent so as to bring it over to the saw as shown. This sup- ports the vertical arm, A, of the deflecting device. A short section of wood, B, was bolted to the end of the tire steel, and to this in turn, the vertical arm was secured by a bolt, C, which permits the deflector to be swung away from either side of the saw table. ; The deflector proper, D, consisted of a curved piece of wood 214 or 3 in. wide and about 1 in. thick, mortised to a 12-in. vertical section of the same width. In order to eliminate any chance of accident due to cutting through of the deflector, a wood pin instead of a bolt was used to se- cure the mortise and tenon E. Vertical slots in the ends of the arms F and G per- mitted the travel of the wing-nut used for raising and lowering the deflector. Hanging a light on the deflector arm made it possible to adjust both arm and light in one operation.—JAMES M. KANE.

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784 Popular Science Monthly A Balancing Ladder for Use in the Mounting Photographs So That They Home Gymnasium HE balancing ladder was designed for indoor use. In making it care should be taken to have all the parts properly finished so that it will look neat, as well as give good service. The base consists of a frame made of 2 in. plank and when finished it forms a rect- angle 30 by 48 Will Not Curl igen are very few amateur photog. raphers who have not encountered the unpleasantness of pasting photographs on mounts and have them curl up, mount and all. The dry mounting method over. comes this difficulty, but one must have a hot iron. fe) However, the

difficulty may

in. The joint used at the cor- ners is shown 4 at A. .Theup- right planks are 6 in. wide N and are fitted ) im into notches V cut on the in- ner edges of the platform pieces. The braces for the uprights are fitted to their

be overcome by the use of rubber cement such as is used for patching the inner tubes of bicycle and automobile tires. The cement is applied in a thin, even coat = on the back of the print and the face of the

own depth. mount. It is The ladder allowed to dry, proper is made or become of sound, “tacky” be straight- 4. 2," 4 fore placing the grained hard- print on the wood, with . clength i mount. When each rung the print is laid glued and nailed in place. The pivot is : made of a bolt as shown at B. When it is de- sired to main- tain the ladder in a horizontal position, the braces C and D are let into the notches in the blocks as shown at E. The lower ends of these braces are bolted to the upright post and may be quickly taken down. When the device is completed, smooth all parts with sandpaper and ap- ply two coats of spar varnish. For permanent locations, it may be bolted to the floor, but it is preferably left portable. The construction permits this and only ordinary care is necessary to prevent accidents. For healthy, growing boys this apparatus will provide endless fun and exereise.—A. ALDON.

6'3"*6« 2" cipal parts.

<p in place it is rolled down just as in ordi-

A portable balancing ladder and details of its prin- The ladder is tilting or made solid nary mount- ing. As the ce- ment will slightly discolor the mount, if it is white, it is best to cover the entire surface, then when the print is in place the uncovered border may be easily cleaned of the cement by rubbing with the finger end. Roll it into a ball and use the ball to clean the edge near the print. If any of the cement gets on the face of the print it can be rubbed off in the same manner. If the print does not stick properly it is because the cement was not left long enough before the print was applied to the mount. Dry the print well after mount- ing, so that the surface of the mount will not peel off in removing the cement.

ee ee a en

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Tricks of the Trade A simple means of driving taps by power and a small vise for the work bench Homemade Power Tapping Machine for Rapid Work S it was necessary to tap several thousand 4-in. holes in many east iron fittings some means of driving the tap had to be provided. There was no tapping machine in the small shop, but WOOD PULLEYS- LOOSE ON TUBE S TUBE

WOOD BASE Opposite revolving pulleys drive the tap in either direction according to the pressure the foreman was equal to the occasion and quickly made the tap driver shown in the illustration. The shaft was made from a piece of steel tube about 6 in. long and % in. outside diameter. Two wood pulleys were fitted to this shaft, one on each side of the bearing or support. One of the pulleys was turned to 3 in. in diameter and the other to a 2-in. diameter. A countersunk washer was fitted into the two outside faces of these two wheels and the edges of the pipe were beaded out to prevent them from slipping off. Before attaching the pulleys, a piece of cold rolled shafting 3% in. in diameter was centrally babbited into the tube. This shaft was then provided with a central hole at one end to accommodate a tap, which was secured with a grub screw set into a slight depression ground into the tap shank. The shaft is provided with a carrier or dog at each end as shown. These dogs engage with the pins fitted into the outside surfaces of the pulleys. The shaft is arranged to slide axially inside the tube, the amount of the sliding motion being so proportioned that when one set of pins engages one of the dogs, 785 the other set of pins is disengaged. The smaller pulley was used to drive forward and the larger one for backing up. It will be seen that on pressing the work on the tap, the shaft is pushed back and so engages the pins at the front of the machine on the small pulley. Pulling outward on the work draws the shaft out and thus disengages itself from the pins on the small wheel and immediately en- gages with those on the large wheel, which revolves in the opposite direction, backing the tap out of the piece. The tube was held stationary in a wooden block fastened to the bench. One of the belts was crossed. The sur- faces of the pins where they engage were filed flat to make them act promptly.— JOHN L. ALLEN.

A Homemade Bench Vise for Small Work HE illustration shows a cheap and quickly-made small vise for the model maker. It is suitable for any medium and light work. The vise is made from two pieces of band iron 1% in. wide and 3 in. thick, with the jaw A bent as

5" reo IO BE USED AS LEVER ie awl \ . fou lf x18] | 2 ever — B — 16 ts 2

al a _ 1 i CN oT MMMM | D ® CAP SCREW 2 HOLE : ees e fe A 8 Fan BBRASS = w == WASHER 4 z Se — ; i 49 MOLeE \ZwooD SCREW Z je 5"—____»| WOOD WORK BENCH Two pieces of metal and a cap screw with guide pin makes a model maker’s vise

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shown and the jaw B cut straight, with two holes drilled in it. The top hole is 13/16 in. in diameter and the one matching it in the top of the jaw A is % in. in

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786 Popular Science Monthly diameter. The cap screw C is fastened with two rivets, one at the top and one at the bottom, to the jaw A. The rivets D are countersunk on the inside of the jaw. The brass washer on the outside of the jaw B is made of an old piece of 1%-in. brass, and allows the nut E to draw up tight and hold it in position. It is not necessarily round. Drill 144-in. holes in the faces of the nut E and cut off the end of a nail to fit the holes. This is used as a lever for tighten- ing the nut. The nut may be drawn up very tight, when necessary, with a wrench. The 3/16-in. cap screw F is held in the jaw A with a )%in. taper pin, as shown at G, and this bolt acts as a slide guide for the jaw B, which holds it in a vertical position. The lower hole in the jaw B is 7/16 in. in diameter—large enough to slide over the threads on the bolt F.— P. P. AVERY. An Easily Operated Clamp for Con- crete Forms ANY uses may be found for the clamp shown in the illustration. There are no screw threads to bother with IC By Ot ee a 8 peas | ER RR a iCONCRETE 2:0) pO. Job S53 “34.48: the forms in making concrete structures and there is but one moving element- A contractor can have a number of these made by the local blacksmith or machine shop and use them in construction work of any character. A cold rolled bar, 1 in. by 3% in. in diameter and about 3 ft. long should be heated and forged at one end into the shape shown on A. A short bar, 1 in. square and 10 in. long, should be fash- ioned similar to B. The hole in the latter should be just large enough to allow A to slip through with a close fit. It is the lever action which, pressing the diagonally opposite edges of the hole against the bar A, causes the bar B to wedge and hold. The greater the pressure tending to force the clamp jaws apart, the greater the holding resistance. In building a large concrete structure, a contracting company used hundreds of these clamps for holding temporarily in position the wooden forms for beams, window sills, and stairways. A great saving in time as well as money was made, as they did away with the old method of nailing wooden cross-pieces to the forms, They are easily portable and may be moved from one job to another as soon as the concrete sets.—K. M. COGGESHALL, - A Receptacle for Holding Graphite in a Clean Way VERYBODY knows how hard it is to pour graphite from any ordinary container without having it spill or come out too fast and make everything black. If the graphite is put in a discarded tooth- powder can (the kind with the regulating slot in the top) not only can its flow be regulated but it is kept clean and dry. A Simple Homemade Sun Drier for Fruits and Vegetables UN drying is undoubtedly the sim- plest and most inexpensive method of preparing fruits and vegetables for winter storing. A simple drier that can be made at small cost consists of a shallow box with a sash or piece of glass fitted over the top. Bore holes in the sides and near the top and bottom, for ventilation; but cover them carefully with netting to keep out flies and mosquitoes. Set the box at an angle so that the sun’s rays fall directly on the glass. Apples, peaches, apricots, cherries, raspberries, and almost all fruits can be dried in this way satisfactorily. First wash the fruit carefully, discarding any that show signs of being over-ripe or decaying. Slice thin, and lay out in the box without overlap- ping the slices. Turn the slices occasion- ally and take them out as they dry. The only thing to guard against in this type of drier is dust and insects. ee tic in ff! Gp, So Oo a ©o &@2&e& © as }

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A Clip for Removing Insulation from Wires Quickly N the accompanying sketch is shown a handy device for making the opera- tion of removing the cotton or other insulation from electrical conductors easy and efficient. The » clip is very simple to make as it mere- ly consists of a piece of steel 1/16 in. thick and 3% in. wide, bent into the required shape, as shown, then ground and tempered at the cutting edge. Triangular notches are ground or filed in the cutting edge before tempering, make the operation of pulling the insulating material from the wire easier. As a protection to the hand, it is advisable to cement or rivet a piece of leather to the strip—PETER J. M. CLUTE. moves insulation quickly and evenly A Depth Indicator for a House Water Tank HIS depth indicator was built to automatically gage the depth of water in a small house tank and was built entirely of odds and ends of the kind found about any work bench or household. A drum was made of a cylindrical piece of wood 2 in. in diameter furnished with two rims of cigar-box wood 2% in. in diameter. The top rim was then cut down to the diameter of 2 in. except at one point where a tooth was left project- ing out 14 in. and about the same width, as shown at A. A second disk 21% in. in diameter was then cut from cigar-box wood and its cir- cumference serrated with 13 teeth similar in size to that on A, and the space between Amateur - Electrician py nd Wireless Operator 787 them sufficiently wide to fit well over it. The drum was then drilled through the center and mounted as shown on a solid base so to revolve easily about the screw in the center. The toothed disk was then glued to a length of a large spool to bring it in line with the tooth on A and mounted on a pivot so the teeth would engage readily without binding. The tooth disk was pivoted in the center of the base. A card-board disk was then glued over the toothed disk, their centers being placed concentrically. This card-board disk was then pointed off with 13 equi- distant marks, each mark lying directly over a tooth of the gear underneath. They were then numbered from 0 to 12, line from floot Cordboard diol” i *. /Yrum P fo drum.” Drum and float with an indicating wheel to show the water level within a small tank the tank being 12 ft. in depth. A metal pointer was fastened to the top of the base so it pointed down and over the card- board dial as far as the numbers.

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788 Popular Science Monthly Next a flat board was placed in the tank as a float and a stout line led from it over little pulleys down to the drum on the indicator where it was wound around several turns. A heavy weight was fastened to the lower end of the line. The length of line on the drum was a little more than the total depth of the tank. With the float on the bottom of the tank the dial was set so the pointer rested over O. Then, by means of the pulley system, every foot rise in the level of water revolved the drum once, which moved the engaged gear one tooth, repre- senting one foot of water. When the level of the water lowered through use the action was reversed. A Combined Microphone and One- Way Telephone SIMPLE, but fairly powerful micro- phone may be constructed by the amateur very inexpensively. It may also be used as a one-way telephone for experimental purposes. A if (eae ° ') A. t “4 | J og hm lal’ the base to make the sensitive microphone The base is constructed from white pine, and is 3 by 414 by % in. The edges are beveled, and a groove is cut on _ the top to receive the sounding board. This board is made from the same ma- terial, and is 2144 by 4144 by Win. The illustration makes clear that it must be perpendicular to the base of the instru- ment. It should be carefully glued in place and permitted to dry thoroughly. Then the whole thing should be shellacked, or coated evenly with a thin coat of varnish. It is necessary to procure an old worn. out dry cell for the construction of this piece of apparatus. The carbons are taken out and shaped as indicated by 4 and B of the accompanying sketch, and small holes drilled in them, as shown, to accommodate the two screws and the binding-post. The two tetrahedral. shaped carbons are placed directly op- posite each other and their respective bases should be exactly parallel to each other. The carbon that is opposite to the one attached to the sounding board igs held in place by means of a copper or brass strip which is so constructed that it enables the builder of this instrument to make it of any width he chooses as long as it is able to stand rigidly without any support, and is flexible enough to bend to and fro slightly in order to make ad- justments when necessary. It is sug- gested that use be made of a buffing ma- chine or similar apparatus in conjunction with an emery wheel, when possible, in order to cut the carbons to shape. How- ever, if this is not possible, a sharp file can be utilized. The carbons should be ad- justed so that the two points touch lightly. The instrument is then connected up with two dry cells and a 75 ohm receiver. The cord may be made 70 feet long for ex- perimental purposes. If the _ specifica- tions are carried out as herein indicated, it is possible to hear a person whistle or sing even though the receiver is 50 feet from the sounding board. A _ person walking in the room where the board is placed, can be distinctly heard. Restoring Bichromate of Potash Used in Battery Solutions ICHROMATE of potash used in elec- tric batteries can be restored so that it can be used over again. The bichro- mate of potash battery in whatever form, is one of the most powerful and handy electric batteries to use where high-volt- age and large current are required for a short time, for general experimental work. By treating the used up residue of bi- chromate of potash or bichromate of soda solutions which are thrown away as use- less, they can be made to give electric currents over and over again. In order to give them a new lease of life the method is as follows: = ©,0 ds" 3 tee . ai le ci ae eee ee ee ee ae — ~~ TF = 4 85 oc} or 4 st CO an tt Get oe on tot 4 ae a ae

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In generating an electric current the pichromate of potash is converted into chrome alum, and all that is necessary to do is to convert it back again into bichro- mate of potash by fusing it with an ox- idizer. Heat in a crucible, to incipient redness, a mixture of chrome alum (or chromium sulphate, if bichromate of soda was originally used), and nitre, using about equal parts of each and stir until the elements arefused. Test a portion of the fused mass by dissolving a small amount of it in water. If a pure yellow or an orange colored solution is obtained; the crucible may be withdrawn. If the solution is still slightly green, add more nitre. When the color is right, pour the material on to a stone or iron plate. To make a battery solution, take a sufficient amount of the restored bichro- mate crystals and dissolve in water until the solution attains the strength that you usually make it. Then add the acid and your battery is ready for business again. Another mixture which is more quickly made, but less efficient, and one which I do not recommend, as it gives off a de- cidedly disagreeable odor, is to add chloride of lime to the used up solution. This must be done out of doors. The solution turns a greenish yellow, and a heavy deposit of sulphate of lime settles. Decant, and add fresh acid and you have a solution which will do for batteries which are kept in some barn or chemical laboratory, as the batteries will smell strongly of chlorine. A Delicate Sound Amplifier for Telephone Receivers WO Danish inventors have patented in this country an interesting sound amplifier for telephone receivers. Though sound amplifiers are not new, the sim- plicity of this particular instrument has much to recommend it. Youthful in- vestigators along electrical lines may want to make one like it with a view to learning something about the attractive field of sound and sound amplification. The framework of the apparatus looks much like a small table book-rack. To the left standard a small board 4 or 5 in. square is nailed, and through a hole in the center of this the telephone receiver hangs, small end downward. It may Popular Science Monthly 789 even project through the base board of the “‘book-rack,’’ but this does not matter, provided it clears the table beneath. A spring pushes up on the right-hand side of the receiver supporting-board, and through it a small set screw passes, so that the receiver’s height can be slightly altered when necessary. Near the top of the “‘book-rack’s”’ left Ul panetlll nine 7 4 Me Mer at LR The telephone receiver mounted in a frame with a horn to make the amplifier standard appears a hinged. support for a sound box—this latter much resembling an ordinary metal pill box or other similar container. The horn is attached to the top of the soundbox, and across its bottom a membrane is stretched. A kind of a trunnion is attached to this membrane, terminating in the head of a pin or other small ball, which is intended to press against the diaphragm of the telephone receiver below. The several adjusting screws shown serve the purpose of adjust- ing the pressure of horn and sound box on the receiver diaphragm to give the best results. Connected up with a telephone trans- mitter in the usual way or with a micro- phone, this type of apparatus will give unusual results. A microphone may be made by standing a cigar box upon end, and gluing a piece of carbon to the center of its bottom. Pressing on this, is an- other small piece of carbon, held up by a short length of coil spring made out of copper or other wire. The bottom of the cigar box acts as a sounding board, and if you talk against it, the carbons are vi-

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790 | Popular Science Monthly brated sufficiently to act as a transmitter when connected in on the circuit as shown. Microphones may be made very sensitive, and, when combined with the sound- amplifying contrivance here described, should make exceedingly faint sounds audible. The induction coil shown in the micro- phone circuit is not strictly necessary, but Two pieces of corbon in contact Receiver am Battery A microphone made of a cigar box and its wiring diagram to the induction coil it will improve the operation of circuits. The primary (big-wire) side goes in the battery circuit, and the secondary (fine wire) side in that of the receiver. An in- duction coil of suitable size may be pur- chased from any telephone company. Switchboard Constructed for Use in the Laboratory HE illustration shows a simple com- bination of switches that can be used to flow a current of electricity in different strengths for making tests in a laboratory. The switches can be con- nected with the ordinary commercial line carrying 110 volts. Referring to the A eaihtnstion of switches ona hase for directing electric current for a laboratory illustration, when 1, 4 and 5 switches are in contact, a straight current flows at the terminals. Switches 1 and 4 cuts in a series through the coil, and 3, 4 and 54 series through the light. The switch 2 cuts the light into the circuit and 5 cuts the coil into the circuit. A common arc light coil is connected to the terminals at the point marked cojl and a 110-volt lamp at the place marked light.—T. I. DEKLE. Alternating Current Charging With- out Rectifier T is not absolutely necessary to have a rectifier with an alternating current for charging storage cells. Imagine that we have a 6-volt storage battery in need of charging and that the house mains pro- vide current at 110 volts A.C. We hook in a bell transformer stepping down the voltage to nine volts as shown by the sketch, and then connect six ordinary dry- cells—new ones—in the secondary cir- cuit, the dry cells being in series with the storage battery to be charged. It is es- Transformer HOV. AL. mains HM Hookup for dry cells with transformer to rec- tify alternating current for battery charging sential to connect the carbon pole of the dry cell battery to the positive pole of the storage battery. Now to show that the battery is actually being charged: Let us consider conditions when the direction of flow of the A. C. is the same as the direction of flow of the dry cells—for convenience we will call this direction positive. Our transformer gives us 9 volts in a positive direction; the dry cells another 9 positive, while the storage battery gives us nega- tive 6. The algebraic sum or resultant voltage is plus 12. Consider now the other or negative alternation. Our dry cells give us plus 9; our transformer minus 9 and our stor- age battery minus 6. Resultant, minus 6. In other words, on the positive or charging alternation, we have 12 volts acting to force current through the bat- tery, while on the negative alternation we ewe etwensrac BeOBORE TH

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have only 6 causing a discharge. The net result is a pulsating charging voltage of 6. The more skeptical of us might think that all of the current effective in charging comes from the dry cells and that the al- ternating current is not effective. But if we connect the dry cells to the storage battery, we have 9 volts charging against 6 tending to discharge, giving us an effec- tive charging potential of 3 volts or only half the value obtained with the alter- nating current arrangement. With the connections shown, the charg- ing rate would be very low because of the high internal resistance of the batteries. Connecting several rows of dry cells in series parallel to provide the 9 volts would considerably hasten the charging. This method is recommended as a good one for use in connection with storage cells which have been sulphated, Bennett or Daniell cells taking the place of the dry batteries. The frequent alternations coupled with the low charging rate make for rapid cor- rection of the sulphation.—E. F. HAL- LOCK. Some Methods of Construction for Telephone Wires T the right side of the illustration Fig. 1isshowna way of running aruralline along the top of a fence, the line wires Wa “UH \ ‘a g- WIRE THROUGH a r GALY. PIPE ig ae Yi WLW, Z Yj Sy N y WHA BEND Popular Science Monthly 791 being carried on insulators secured to the top of the fence posts. In the main part of Fig. 1 is shown how the wires are carried past a gate, and in Fig. 3 is shown how the wires are run through water-supply tunnels and large sewers; while Fig. 2 shows how large trees are sometimes used to support the wires and eliminate the cost of pole line construction. When necessary to carry wires as shown in Figure 3, a regular lead-covered cable or an armored submarine cable is secured to the top of the tunnel or sewer by means of galvanized iron clips and brass screws which are driven into expansion shields. This method is generally used to supply service to a pump station or water intake which is situated out in the water some distance from the shore. When the water is quiet, as it is in a lake, the service is generally supplied by means of a regular submarine cable laid on the bottom of the lake; but when the cable must cross a swift-running river, it is advisable to put in the tunnel to prevent its being broken by the weight of water which would be constantly pressing against it. In Fig. 1 the ends of the pipe coming up from under the driveway are bent down- ward at the ends to prevent water from entering the pipe during rainstorms or from the dew and rotting the insulation from the wires.—GEORGE M. PETERSEN. DOUBLE GROOVE N INSULAT — [ree Three methods of line construction to reduce the first cost, using a fence, tree or tunnel casing for supports aAlt.

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792 Popular Science Monthly An Electrically Heated Inhaler for Respiratory Troubles EVERAL home remedies for respira- tory troubles are inhaled in the form of steam. The medicine is placed in boiling water, and the fumes are breathed through an inverted funnel. A much more satisfactory way of doing this, par- ticularly at night, ' is to heat the fluid by electricity in the manner illus- trated. The body of the apparatus consists of a cheap jam jar with a tin cover that fits on tight- ly. Two holes about the size of a lead-pencil are drilled, one in the center and one at the side, of the cover. A _ metal tube about 4 in. long is soldered over the central hole, and another piece of tubing about 2 in. long is slipped through the hole, near the side, and soldered in place with half its length extending upwards. Bush this tubing at the top and bottom with fiber or hard rubber, and have an }%-in. hole drilled through each bushing. A third piece of tubing 1 in. long is soldered on the under- side of the cover diametrically opposite the 2-in. tube. Remove the central carbons from two discarded flash-light batteries and thor- oughly clean them. Remove the brass cap from one carbon and fit it tightly into .the end of the shortest tube. Solder a rod or a large wire nail to the top of the brass cap on the other carbon. Slip this rod through the holes in the bushings, and cut it off after allowing 14 in. to project when the rod is raised as high as the car- bon will permit. Finally solder a binding post or some sort of connector to the upper end of the rod. The lower ends of the carbons will now have to be trimmed off, so that when the cover is in place the stationary carbon will come within )% in. Jam jar fitted with necessary electrodes of the bottom of the jar and the movable carbon will be at a similar distance when it is at its lowest position. After soldering a second binding post to the top of the tin cover, the inhaler is complete. To test it, put in about 3% in. of water, and connect it directly, without resist- ance, to the 110 volt current. Unless the water is unusually free from mineral salts, it should boil in one or two minutes, If it does not do this, add the slightest pinch of table salt. A steady stream of steam should now issue from the central tube, after which the adjustable carbon may be raised almost out of the liquid. Even though the temperature of the water rises gradually, there is no danger of breaking the glass. When everything is operating smoothly, drop the medicine down through the central tube with a medicine dropper. It can readily be seen that with this apparatus the volume of the steam and the strength of the solution are always conveniently within control. Ignition Hookup for Use on Auto- mobile Circuits LECTRICAL ignition systems are generally operated on low voltages from primary batteries, storage cells, or small low pressure generators. The series- A hookup to prevent a loose connection from rendering the entire series useless multiple connection shown in Fig. 1 is generally used. If additional cross-connections are made, as illustrated in Fig. 2, it will be found that a loose connection in one series of cells will not render the entire series useless.—PETER J. M. CLUTE.

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Electrical Devices and How They Work V.—Principles of the induction coil and transformer By Peter J. M. Clute, B. E. around an iron core, as shown in Fig. 1, and connected to a battery circuit, and if another coil is wrapped about the same core and its terminals connected to any current detector, as shown in the illustration, it will be found that when the key is closed, the deflection I’ a coil of insulated wire is wound ew —— itt a ‘Magnet Detector coil Fig. § * Jilustrating the working of an induction coil and alternating current transformer Hk Battery of the detector needle indicates a tempo- rary current induced in one direction through the left coil. However, when the key is released, an equal but opposite deflection will be an indication of an equal induced current in the opposite direction. This simple experiment illustrates the fundamental principle of the induction coil and the alternating-current trans- former. The right coil which is connected to the source of current, is called the primary coil, and the left coil,.in which current is induced, is the secondary coil. This coil causes lines of force to exist inside of the primary coil—in other words, magnetizes the space inside of left coil, which is the core about which both coils are wound—and thereby causes an induced current to flow in left coil. De- magnetizing the space inside of left coil also induces a current in the coil. This is in accordance with Lenz’s Law, namely, that any change in the number of mag- netic lines of foree which thread through a coil induces a current in the coil. If half of the turns of the secondary are unwrapped, the deflection when the cir- cuit is opened or closed will be found to be about half as great as before. Since the resistance of the circuit has not that circuit. 793 changed, it can be deduced. that the E. M. F. of the secondary is proportional to the number of turns of wire upon it. This results from the principle that the E. M. F. induced in any circuit is equal to the rate of cutting of lines of force by All the lines produced by the primary and which pass through the core, cut all the secondary turns. If, therefore, there are twice as many turns in one case as in another, theoretically twice as many lines of force cut the circuit, and hence the E. M. F. is twice as great. If, then, it is desired to obtain a very high secondary voltage, it is only necessary to build the secondary coil of a very large number of turns of fine insu- lated wire. The induction coil, shown diagram- - matically in Fig. 2, consists of an iron | core C, composed of a bundle of soft iron. wires; a primary coil wrapped around this core and consisting of a small number of turns of coarse insulated copper wire, connected to the battery circuit through the contact-point at the end of the screw. D; a secondary S_ surrounding the + TT a) Condenser — Hie Fig. 2 A diagrammatic illustration of an induction coil with one wire coil on top of the other primary is indicated, and consisting of a very large number of turns of fine copper wire, the terminals of which are ¢ and @’; and an electromagnetic hammer H, or other arrangement for making and break- ing. the primary circuit. When the primary is closed, the core becomes magnetized. Thereupon, the iron hammer H is drawn away by mag-

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794 Popular Science Monthly netic action from its contact with D and the current is thus suddenly stopped. This instantly demagnetizes the core and induces in the secondary an E. M. F., which is usually high enough to cause a spark to leap the gap between ¢ and t’. As soon as the core is demagnetized, the Common magnetic circuit * of laminated iron }

Fig.3 Form of a transformer core that keeps the lines of force in a continuous iron path spring R, supporting the hammer, re- stores contact with D and the operation is repeated. The condenser, shown in the diagram, is not an essential part of the coil; but when it is introduced, it is found that the length of the spark sent across the air gap is considerably increased. The commercial transformer is a modi- fied form of the induction coil. The essential difference is that the core in Fig. 3, instead of being straight, is bent into some other form such that the magnetic lines of force have a continuous iron path, instead of being obliged to push out into the air, as in the case of the induction coil. Furthermore, it is always an alternating instead of an intermittent direct current which is impressed on the primary P. Sending such a current through the primary is equivalent to Core Secondary Core.

‘ + CE ' 7 IGS}: - | (LLL P ~ =» A CZ SSH: |

(ZZ

‘primary Fig. 4 Diagrammatic illustration of two general classes of transformers, a core and a shell type magnetizing the core first in one direction, then demagnetizing it, then magnetizing it in the opposite direction, ete. The re- sult of these changes in the magnetism of the coil is, of course, an induced alter- nating current in the secondary coil § If there are few turns in the primary and a large number in the secondary, the transformer is called a step-up trans. former, because the voltage produced at the secondary terminals is greater than that impressed at the terminals of the primary, by the ratio of the number of turns of primary and secondary coils, Thus, an induction coil may be said to be of the step-up type. For some uses, how- ever, transformers may be of the step. down type. For example, 2000 volts are impressed at the terminals of the primary, and a lower voltage, say 100 volts, is obtained at the secondary termi- nals. In such a case the primary will have 20 times as many turns as the sec- ondary, and, we call it a 20 : 1 step-down transformer. Assuming that the losses in the trans- ( aT (et el

<2 Wot

/ Fig.5 rig.6 The usual arrangements of coils and core for a shell type polyphase transformer

former are so small as to be negligible, the same number of magnetic lines of force passes through both primary and secondary coils. Since the E. M. F.’s in the two coils are proportional to the number of lines of force multiplied by the number of turns in the coil, it follows that the E. M. F.’s are directly proportional to the number of turns of wire upon the two coils. Transformers are divided into two gen- eral classes, namely, core transformers and shell transformers. These two types are illustrated diagrammatically in Fig. 4. Transformers for two- or three-phase currents can be made by combining two or three single-phase transformers into one piece of apparatus. In certain cases, polyphase transformers are desirable, but general practice is to use two or three separate single-phase transformers for transforming polyphase currents. The usual arrangement of coils and core for

ean ta twte TH ft bet tet lUettl luk.

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-type polyphase transformers is sang Fig. 5 and 6. The three-phase type is equivalent to three single-phase transformers placed against one another. There are three distinct sets of coils, but the core forms a part com- mon to all three. By combining the core in Ip-ls Is Fig.7 A diagram for the winding of an autotrans- former arranged to step up the voltage this way, a saving of iron is effected and the core loss slightly reduced. A two-phase transformer gives but little saving over two single-phase ones, as is seen by reference to Fig. 6. Another type of transformer often employed is the autotransformer. They differ from the ordinary type, in that they only transform part of the total power supplied to them. In addition, the primary and secondary coils are con- nected in series, instead of being entirely separated. In the autotransformer, power is partly transferred by direct electrical conduction from primary to secondary, and partly by means of the alternating ’ Supply mains f | Ep = Ip Ip QO000000 5 Ip Is-Ip A diagram for a Is Is transformer that + 5 ————+ lessons or steps downthevoltage .. Fig.8 ry 4 field. In the ordinary transformer, the two coils are electrically separate, and neglecting losses, the total power supplied to primary is transferred to secondary — the medium of the alternating ux. In Fig. 7 is shown a diagram of the winding for an autotransformer, arranged to step up the voltage, and Fig. 8, a dia- Popular Science Monthly .secondary current. 795 cram of one for stepping down the voltage. In the former the high-voltage mains are attached to secondary, while in the latter they are connected to primary. Referring to Fig. 7 and 8, Ep denotes the primary E. M. F.; Ip, primary cur- rent; Es,.secondary voltage; and Is, Whatever the wind- ing arrangement may be, the rule of voltage transformation is the same as for transformers having two insulated wind- ings. Thus, if Tp denotes the number of primary turns, and 7's of the secondary, then, Ep: Es = Tp: Ts. Neglecting losses, primary input equals secondary output, or Ep Ip = Es Is. Whence, Js = Tp Ip + Ts. Thus, the secondary current in the autotransformer is equal to primary current multiplied by the ratio of primary to secondary turns. Here Is an Interesting and Artistic Electric Battery Tester HE battery tester shown is designed to show the condition of electric batteries and will indicate roughly the amount of energy left in any cell. It is very easily constructed, and if the work is carefully done, the instrument will make a handsome and useful addition to any amateur’s set of electrical appliances. Procure a 4-in. test tube. These tubes come in different lengths and the longer the tube the higher the wire coil will be and the more wire will have to be used. Having selected the tube, measure its outside diameter. Then get a piece of pine board 34 in. thick and about 5 in. wide. Mark with dividers, a small circle in the center of the board. The circle should be 3 in. larger than the outside diameter of the test tube. Also mark a 414-in. circle concentric to the small one. Bore a hole through the center circle, then cut the wood with a saw or knife as close to the line of the outside circle as possible and finish with sandpaper tacked on a block of wood. Get a small stove bolt or a machine screw and a cork. Punch a hole lengthwise through the center of the cork with a bradawl. Then put the stove bolt through the cork, using a screw driver for the purpose. Allow the bolt to extend more on the bottom than on the top of the cork. The bolt

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796 Popular Science Monthly should then be filed or cut so that the cork will just keep the bolt on the surface of a glass of water. Both the bolt and cork should then be dipped into hot melted paraffin wax so as to leave a thin coating on the surfaces. This keeps the Current tester, consisting of test tube of water, cork and bolt, all surrounded by coil cork from becoming saturated with water and also prevents the bolt from rusting. Now take the test tube and tie it in an upright position to any convenient object. The round end should face toward the bottom. Fill the tube two-thirds full of water and put the cork with its bolt in it. Get a cork of sufficient size to fit the open end of the tube. Dip the cork in shellac, varnish it, then drive it into the tube, so that the side of the tube projects about 1% in. above the top of the cork. Let the shellacked cork dry, then fill up the space between the top of the cork and the edges of the tube with plaster of paris or cement—the latter preferred—making it level with the edges of the tube. When it has hardened, take a piece of emery paper and roughen the glass on the sides of the tube for about 1% in. from the end. This is to enable the cement to grip the tube tighter when it is fastened to the base board. Place the base of the instrument on a level surface and put the tube, corked end facing downwards, in the center of the small hole, the end of tube to be flush with the bottom of the base. Then fill the cavity between the sides of the base and the tube with cement, keeping the tube in an upright position until the cement hardens. The flange holding coil is made from cigar-box wood or other thin material, Nothing is to be gained by making the - coil more than three times the diameter of the test tube; that is, if the outside diameter of the tube is 1 in., the total diameter of the coil including the tube will be 3in. In other words, there will be 1 in. on each side of the tube. Measure the outside diameter of the tube, then mark on the board a circle of the required size and also mark with the dividers, a circle for the outside diameter. If a 1-in, tube is used, the diameter of the flange should be 314 in. wide, the 14 in. oversize being left to extend over the wire coil, as will be seen in the sectional view of the battery tester. Put the wooden flange on the test tube and slide it down to the center (it should fit the tube as tightly as possible), then glue it in place and let it dry. Get 1% lb. of No. 20 double cotton covered magnet wire and wind a sufficient amount of it on the spool to nearly fill it up, but allow the top flange of the spool to project 1% in. on each side of the wire. In winding the wire, start and finish at the bottom, leaving 6 in. of wire on each side of the spool to connect the magnet with the binding posts, there being one of the latter on each side of the coil. Scrape the insulation off of the connecting wires and insert it under each binding post. The wood work should be enam- eled so as to make an attractive instru- ment. The enamel should also be put on the bottom and over the plaster of paris or cement seal and the joints where the tube is flush with the base. Four brass tacks spaced at equal distances should be placed on the bottom of the base. The test tube is then ready for use. Connect a wire from the zinc of the battery to one binding post and the car- bon wire to the other. The cork and bolt will then dip and rise as the circuit is closed and opened. The _ stronger the battery is, the quicker and deeper the bolt will sink. If the battery is nearly exhausted, the bolt will merely move about on the surface. A _ very artistic tester can be made by enameling the base of the tester red; coloring the spool flange black, the wire coil green, and the cork and bolt black. — _ -«. na ae - hee ot. ee he ao

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Wireless Work in Wartime X.—The Non-Synchronous Gap Radio Transmitter By John V. L. Hogan article, the general operation of the spark gap and primary oscillation circuit of a typical radio sending station, further and more specific types of spark gap may now be considered. In the il- lustration Fig. 38, printed last month, was shown a simple fixed air-cooled gap; and Hvis taken up, in the previous Fig. 39 An old type of a rotary spark gap which has been in general use for some time for wireless the accompanying Fig. 39 shows a type of rotary spark gap which has had wide use. This consists of a rotating conducting arm A, having spark electrodes on both ends and mounted upon a driving shaft so that it may spin between two semi-cir- cular frames B, B. Supported on the frames are a number (in this instance ten) of fixed, equally-spaced electrodes. The five on one frame are connected together and act as one terminal of the spark gap; the other five form the other terminal, being connected together in the same way. The length of the studs and the separation between them is so chosen that when the rotating arm is almost directly in line with any one pair there will be only two short spark gaps in the circuit. If at this time the transformer (and condenser) voltage is near its maximum, sparks will pass and the condenser will discharge with oscillations, as previously explained. If the rotating arm has passed out from a position almost directly between two stationary studs, however, not even the maximum secondary potential of the transformer can force a spark to jump. ~ é The Disk Rotary Gap Another type of rotary spark gap is shown in Fig. 40. Here there are two stationary terminals D and E, and be- tween these there rotates a spoked wheel F. Each spoke has a spark gap tip G at its outer end; the length of the spokes and their distance apart is selected so that sparks can pass only when they are almost directly in line with the stationary elec- trodes. It is evident that these two types of rotary spark gap have much in com- mon; in both of them the gap length is continually changing, and in both the gap is cooled and kept clear of conducting gases by the air circulation stirred up by the rotating member. - There are two general ways of using the rotary spark gaps. The gap of Fig. 39 is generally used according to one of these, the “non-synchronous” method, and has consequently come to be known as the non-synchronous rotary gap. Thesecond type, of Fig. 40, has had its widest use according to the second or ‘‘synchronous” method, and is therefore often called the synchronous rotary gap. Neither of these names is strictly correct, however, Z Y Yj Y Sms The second type or synchronous method is usually called the synchronous spark gap since there is no reason why either gap should not be used according ‘to either the synchronous or non-synchronous method. This will appear from an ex- amination of the two types of operation. 97

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798 Popular Science Monthly Non-Synchronous Operation Taking up the non-synchronous dis- charge first, let us imagine that the ro- tating part of either gap is revolved by a direct current motor and that its speed of AC Power transf. a A diagram of a radio transmitter with a rotary spark gap interposed in the apparatus rotation has no particular relation to the alternating current supplied to the power transformer in Fig. 41. As the secondary of the transformer charges the condenser, the spark-gap rotating electrodes R, R, are constantly moving toward or away from the fixed electrodes F, F. If the instant of maximum potential of the trans- former should occur while the spark gap contacts are widely separated, no spark would pass and the condenser would dis- charge back into the transformer second- ary on the next half cycle of applied power. If, on the other hand, the spark gap electrodes were quite near together when maximum potential was reached, a spark would pass and a group of radio frequency oscillating currents would be produced in the primary circuit. When the spark gap rotor is driven inde- pendently of the applied alternating current power, i.e., non-synchronously, it is evident that the time a spark will pass (and, in fact, whether or not a spark will pass at all) depends entirely upon chance. The only way to be sure that a spark will pass for each half cycle of alternating current applied to the power transformer is to increase the speed or number of electrodes of the rotary gap so that at least one opportunity for sparking will exist near the maximum voltage portion of each half-cycle. In commercial prac- tice this has usually been accomplished by running the spark gap at a speed which corresponds to approximately 600 sparks (or, more strictly, ‘opportunities to Fig. i spark’’) per second when the supply eyp. rent is of 60 cycles per second frequency, Thus in each half-cycle of secondary volt. age there are five instants at which the condenser might discharge across the spark gap, provided only that at each of these times the condenser voltage jg higher than the minimum required to break across the shortest spark gap. How the Condenser Discharge Time Is Varied How the adjustment of the gap affects the times of sparking may easily be seen by studying Fig. 42. Here the solid curve represents the numerical potential value of the secondary condenser charge, as it is produced by the power transformer and without allowing for effects of with- drawing energy by the spark discharge, The dashed curve above represents the breakdown potentials of the rotating spark gap, and both are drawn for the same successive instants of time. The divisions along the horizontal axis repre- sent time intervals of 1/600 second, and consequently ten of them are contained in two half-cycles or one complete cycle of audio-frequency voltage at 60 cycles per second. The voltage curves are all plotted above the axis, since in this case we are concerned only with the numerical value of the voltage and not at all with its direction—the spark gap will break Volts OOO ETT TT ET AT Te TT PiSiSTELELOLESELEAELETERESETEAE ETRE ETE ooo raiiiiieaiititrt tetera tet a0 o2 fertee Be 34 se 2 aH 5000 0 t—+—+—4 + 5 10 iS wo Fig. 42 es Curves showing the operation of the non- synchronous spark gap for a wireless set down whenever the potential rises above a certain approximate value, substan- tially without regard to the direction of potential stress. The voltage is assumed to vary from zero to ten thousand. Continuing with Fig. 42, the upper dashed curve may be understood by imagining the successive separations be- twe the $0 | a a t h 1 e a g I t t i i a i i a i i

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tween the rotating and fixed electrodes of the rotary gap. If the studs are set back so that when-the gap is the shortest (i.e., when the electrodes are exactly in line) a voltage of 7,500 is required to cause a spark to jump, and if the design is such that a potential of 15,000 volts would force a spark across even when the elec- trodes are farthest apart (the moving studs exactly half-way between the fixed), the conditions illustrated in Fig. 42 will be had. The spark gap is supposed to have the number of studs and the speed chosen so that the electrodes approach and recede 600 times per second. The illustration Fig. 42 shows roughly what will happen in four half-cycles under these conditions. The first time the gap be- comes closest there will not be enough po- tential to break it down, so the spark will be missed. The second time will produce a spark, since the secondary condenser will just have reached 7,500 volts. The third spark will pass, as will the fourth. These are indicated by shaded portions where the two voltage curves overlap. The fifth and sixth sparking opportuni- ties will be missed, because the condenser voltage will in neither case be high enough to break across the minimum gap length. At the seventh, eighth and ninth oppor- tunity sparks will occur, and the tenth and eleventh will miss. The twelfth, thirteenth and fourteenth will pass, but the fifteenth and sixteenth will be lost. Thus it is seen that there will be three sparks in each half-cycle, at the distance represented by 1/600 second of time, and that between each group of three sparks there will be an idle interval of 1/200 (3/600) second. If the sparking opportunities do not occur at exactly 1/600 second separa- tion, but slightly less often, there will be two sparks in some half-cycles and three in others. This will give a fairly complete idea of the rotary gap operating upon the non- synchronous principle. You should go over the details of this type of non- synchronous gap operations until you have firmly in mind the relations of voltage and gap length. The effect of changing various adjustments will be treated next month, when the quenched and rotary synchronous gaps will also be described. (To be continued.) Popular Scvence Monthly 799 How to Make an Efficient Weather- Proof Goose-Neck VERY efficient weather-proof goose- neck wall bracket can be easily con- structed as shown in the illustration. It consists of a piece of 14-in. conduit bent RUBBER GASKET: HING WOOD BLOCK LOCKNUT PIE PLATE: BUSH) OUTLET Box A conduit bent and fitted with pie-plate reflector to make a weather-proof goose-neck in the shape shown and fastened into the wall with a locknut. The outer end has a wood block or disk attached with a lock- nut and rubber gasket. On the under side of this disk is an inverted pie plate to which the lamp sockets are securely attached.—Curis. BAcH, JR. A Temporary Repair for a Slipping Magneto Shaft BOUT the most annoying mishap a driver has to contend with on the road is that of a magneto shaft slipping endways so that the gears will be out of mesh. One cause of this trouble is the pump wheel shearing its pin and allowing the shaft to slip endways and out of mesh with the gears. In order to take the pump off and make the repair it is necessary to remove the starter, and this is entirely too big a job to do on the road. TIMING GEARS Placing a cotter in a magneto shaft to keep it from shifting endways out of gear mesh The repair may be made in a temporary manner as shown in the illustration. A hole drilled through the shaft just in front of the stuffing box, as shown at A, provides a way for holding the shaft with acotter. It is then only necessary to time the distributor, and the engine runs the same as before.—P. P. AVERY.

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800 Cleaning Spark-Plugs with Phono- graph Needles HE usual way to clean spark-plugs is to take them apart and scrub them with a brush after scraping them with a knife. An easier and quicker method is here de- scribed. Secure a small cylinder open at one end, into which is fitted a bushing with threads corresponding to those on the ends of the plugs. After fill- ing the cylinder about half full of gasoline, throw in a dozen or more old phonograph needles, then screw the plug in the cylinder. After giving it a good shaking, remove the plug. The end will be thoroughly cleaned, more thoroughly than if it were scrubbed and scraped in the usual way.—PETER J. M. CLUTE. CYLINDER PHONOGRAPHESSZ d Phonograph needles remove carbon deposit A Good Permanent Base for Small Battery Switches O doubt many an experimenter and many a student in an electrical school has had the misfortune to break the frail wood base of a battery switch. A switch made like the accompanying il- lustration will last almost indefinitely. Take a piece of 1%-in. fiber, 214-in. square and place it in the chuck of a small A battery switch base turned from fiber makes a substantial mounting for the parts lathe, and recess the bottom 2 in. in diameter and 4 in. deep, as shown in the sketch. Before removing the fiber from the chuck, drill a 3/16-in. hole in the Popular Science Monthly center, remove it from the chuck and pyt a 3/16-in. bolt into the center hole ang lock it with a nut of the same size. The bolt is then put into the chuck, and the outside is turned round. The radius of the switch lever and: the size and the distance apart of the switeh point holes must be determined from. the style of switch from which the parts ape taken.— WALTER B. WEBER. This Lighthouse Sends Radio Fog Warning Far Out to Sea OINT JUDITH LIGHT, near Ney. port, R. I., is now equipped with a radiophone fog-warning machine. The words “‘Point Judith Light!’’ are repeated every five seconds and can be heard any. where within a radius of about eight : miles. After every third warning the words “‘You are getting closer; keep off!” | These can be heard about | are sent out. two miles away. Wave lengths keep changing continu. © ously between 550 and 650 meters, in © order that operators on passing shipg ~ may be more likely to hear. the messageg © even if at the moment they may not be tuned exactly to a standard wave length. The system is likely to be im _ proved at intervals. All lighthouses could” profitably employ such a contrivance ifit” works out well in practice. a Opera Hat with Enclosed Electri¢ J Light for a Sign a ROM a French inventor comes an advertising sign in which an opera: hat is its housing. The sides of the hag are cut so that letters are removed thas spell out the words of the sign. These letter holes are covered over with a: thi light fabric of the same color as the t When unlighted the letters remain in” visible, but with one or more battery” lamps placed inside and lighted, the hat” becomes a conspicuous advertisement The batteries may be carried in the pocket and wired under the coat to the neck? and up to the hat over the hair on the back of the head. The current can be™ flashed on and off with a switch in the coat pocket. This is a real novelty im advertising signs and one which would be sure to attract attention. )