Popular Science Monthly 1921-06: Vol 98 Iss 6

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29 30) 60 60 64 71 71 ——_— npany nthly. $3.00. cents. yse the ate of y Dec. ler the Ss mate ‘ighte od jission. sident; has ina ceaies June, 1921; Volume 98, No. 6 25 Cents a Copy; $3 a Year Popular Science Monthly Waldemar Kaempffert, Editor Published in New York City at 225 West Thirty-ninth Street Stunting with a Three-Wheeled Tractor And all three wheels are power wheels HIS is a tractor unlike any of those with which we are familiar. It is a three-legged machine. It is shewn, with its designer, doing tricks. It is going over rifle-range butts, a dangerous thing for a tractor to do. This machine is a fast worker. It is able to plow seven and one half acres in six hours’ time. It would take a number of horses to do the same amount of work in the same amount of time. In plowing this acreage, the tractor uses only one and_ three quarter gallons of gasoline, which costs less than the feed a horse would eat in doing the same work. The efficiency of a tractor is meas- ured largely by the ‘‘pull’” it has. The “pull” is measured in pounds. - If a tractor has a “tractive effort”? that is more than the weight of the machine itself, then the efficiency of the machine is high. his little tractor is able to make a_ continuous drawbar pull equivalent to 3250 pounds. It can Doing stunts with a tractor on the rifle-butts. By Raymond F. Yates pull up to 5600 pounds, which is more than the gross weight of the machine. , Of course, this high pulling power can- not be maintained for any great length’ © of time. It is only during momentary jerks that the machine is able to exert ; its maximum strength. This tractor succeeds where other tractors fail because all of its wheels are provided with power. ° It-is a three- wheeied machine and‘ it is a three- wheel drive. The engine is connected with each of the wheels. The tractor has been provided. with three wheels for a good engineering reason. It excels in wheel grip because the three wheels have an equal distri- bution of weight upon them when the machine is in motion. Pulling with two front wheels and one rear wheel causes the wheels to press into the ground equally and evenly as the strain increases, thus insuring them against the common fault of slipping, skidding, and the danger of over- turning. The Jow center of gravity also helps to keep the machine on its feet. The little tractor is not only good for field work on the soil, but it may als be used as a general power unit on th farm. A pulley directly connected with the engine is provided for this purpose. The driver’s seat is placed at the side of the one rear wheel of the tractor, and the driver has a clear view of the work in front of him and command over the plow or other following implement. The machine drives like an automobile; most of the controls are operated by the feet. This tractor can travel up a steep incline, pulling three plows after it. This is a hard test indeed, since many a tractor fails on a grade when it has but one plow to pull after it. This three-wheeled farm tractor is seen here going over the top, with the man who designed it sitting at the wheel 17

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Popular Science Monthly How Science Tracks the Criminal Europe is far in advance of the United States in crime detection P MAHE Sherlock Holmes type of detective, the man who smells a letter and tells at once that the murder was committed by a bald- headed man wearing eye-glasses, may seem a far-fetched creation of the novelist. His exploits have been over- drawn for the purposes of fiction, but his methods are sound. Above all things, he is a scientist. In the whole United States there is no Sherlock Holmes—no detective who studies crimes objectively and dispas- sionately, just as an entomologist studies a bug for identification. The Europeans are far in advance of us in this respect. There are no fewer than four chairs in as many European universities occupied by men who are professors of crime detection, the new science called ‘‘criminalistics.”” These men have laboratories in which the minds and methods of criminals are studied. In Graz, Austria, for example, you will see collections of all the known poisons of Europe, the sword-canes and rifile-canes with which assassins lie in wait to kill, plaster models and accu- rately drawn plans of crimes, the skulls of men who have been killed by blows on the head. Students who take the course in criminalistics are expected to look at a skull and say: ‘‘This man was killed by a hammer blow.” One graduate caught a murderer who had left behind him nothing but a derby hat in which there was a single hair. ‘‘Look for a man_ between forty-five and fifty, partially bald, with gray-streaked hair.’’ The police found him. Why did the scientific detective say that? Because by chemical and microscopic means it had been deter- mined that there was perspiration in the hat; one of the hairs was gray, and it was the kind of hair that drops out of a head that is growing bald. All modern science has been drawn upon in this tracking of the criminal. Professor. Gross, who founded the chair of criminalistics in the University of Graz, could look at the footprints of a man and determine whether he had been walking or running, whether he had been carrying a package or not, and even whether he was suffering from a disease. Bertillon, who did far more than give us the measurement system of classifying convicted criminals, went so far as to gather information on the methods used by Parisian shoemakers in nailing heels in place; for each shoemaker used a definite number of nails and hammered them in according to a plan of his own. Bertillon had only to look at a footprint in order to An oxyacetylene flame was first used in Antwerp more than twelve years ag Two burglars rented a room ove. a banking-office. They drilled a hole through the floor of their room Here is the apparatus that the burg- lars left in the hotel room that they had hired 18 and lowered themselves and the oxyacetylene apparatus by a rope ladder to the room below. The com- bination of the safe was simply burned away deduce the probable. maker of the shoe that left the imprint. The first step taken by a Euro- pean criminalist is to make scientific study of the scene of the crime. He uses either the scientifi: method of photographing devised by Bertillon—a method that makes it possible to measure with the utmost refinement on the photo- graph the distance of one object from another—or else he makes an accurate drawing, noting the exact position in which every object is found. Sometimes he even makes a three-dimensional plaster cast. He looks always for what is technically June, Ca led ovtner thing Gre al ol pi ice clusio his d near 1 hung docto had d real s the ol two Ss One after fallen they to gc dance they r they Lau H* ] one d: in the desire he anc He near | stake bay. with ¢ he adj means ends. paddle the ca direct]. The raised line en; is attac crossbe Whe it is ut own w: shore t -—

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& June, 1921 called ‘‘the error in the*situation’’—in other words, the little unforgotten thing or act that betrays. Gross once found the dead body of ay old man swinging from a chande- lier. Suicide was the verdict of the police, and suicide was the first con- clusion Gross drew. Then he studied his drawing. There was no chair near the man! Somebody must have hung him to the chandelier. The doctors assured Gross that the man had died a natural death! Then the real search began. Gross found that the old man had been left in charge of two servants. One night, after he had fallen asleep, they decided to go to a dance. When they returned they . found 1. The hand of a crim- inal. 2 and 3. Plaster casts of footprints made with a booted and a naked foot. 4. Imprint ofacriminal’sknee. The scientific detective deter- mined that the imprint was left by striped trous- ers made in Manchester. Launching a Canoe with a Rope Railway IGH on a cliff a man built his house. As he sat on the veranda one day, watching the rippling water in the bay below, he was seized with a desire to go canoeing. But how could he and his canoe leap the cliff? He planted a stake in the ground near his house, and drove another stake firmly into the bottom of the bay. He connected the two with a cable. On the cable he adjusted a metal bar by means of pulleys at both ends. Whenever he wishes to paddle on the bay, he chains the canoe to hooks located directly beneath the pulleys. The canoe is lowered and raised by a winch operated by a gaso- line engine. The cable from the winch is attached to the near end of the metal crossbar. And close toit isa brake-lever. When the canoe reaches the water, it is unchained and allowed to go its own way. Some one must remain on shore to start and stop the winch. their charge dead. Frightened, the valet suggested that it would be well for them to make it appear as if the old man had committed suicide. To- gether they hung him, but they forgot to kick over a chair. These men deal not only with the physical facts of crime, but also with the psychology of criminals. It is im- 1 2 3 4 5 Plaster casts made in European de- tective laboratories in order to study crime scientifically To Make It A method of stitching the hem that has lengthened the life of flags lee, the wind. Further The canoe is lowered from the cliff to the bay by means of a winch operated by a gasoline engine experiments sometimes blew out the outer line of stitching, and that the corners wore more rapidly than the center. come this, V-shaped stitching was inserted in each stripe, with a half fan in the corners still stronger, but required a great deal of experiment to overcome puckering. thread was invented for this purpose. The wind-proof flag will not last forever, of course. official tests at Washington have shown that it will last ten or twelve times as long as the ordinary hemmed flag a big cut in expense for the government. portant to learn everything that can be learned of the loves and hates of thieves and pickpockets, their super- stitions, and their slang. The criminal mind is not anormal type. It is firmly believed by thieves, in Europe at least, that something must be left on the scene of the crime to avoid detection. One man left behind two or three matches torn from a block of the kind given away in cigar stores. Professor Reiss, of the University of Lausanne, picked them up. He ordered all the suspects searched. A block of matches was found in the pocket of one. The two incrimin- ating matches dovetailed 5. Acertain burglar bit a section out of a piece of cheese and threw the rest away. This is a into the stubs. cast of the _ bitten We need section. It showed that laboratories one tooth was missing . ' ean eh) and it enabled the bi America police to find the like those de- burglar scribed above. Wave Long HE average life of a flag is thirty days of constant use. In the navy yard at Norfolk, a man who had never seen a flag made, J. H. Herbener, was given the job of increasing the flag factory’s equipment and turning out flags for the Fifth District of the United States Navy. He soon noticed that all the flags returned for repairs were broken just behind the hem. This led him to make and test a flag without a hem. The hem was cut off a standard ensign, and rows of stitching run across the end several inches deep. Flown for four months on the navy yard flagpole, one hundred and twenty-five feet high, during the stormy spring months of the year, it was found that the flag broke down only on the end, and there but slightly. It had lost two rows of stitching at the corners and one in the middle. A patent was taken out on the “‘wind-proof flag,’’ and further ex- periments made. Lines of stitch- ing in one color across the flag altered its appearance, so a method of stitching was de- vised to match the colors in the stitching and pattern. This was done by stitching across the cloth before the flag was made, the ends of the stitching at the edge of the stripe being wrapped up in the seams, thus sealing them against showed that rong winds To over- —a device that made the flag Also a special kind of sewing- But

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Popular Science Monthly Starting on a Journey by © Modern Publishing Compan peep geo in the picture above are hurrying, on foot and in railroad trains, toward a terminal the like of which.is strange to our eyes, but which may be an accom- plished fact in only a few years. A glance at these persons hastening toward the termi- nal shows them taking the same kind of baggage that present-day travelers carry—and, indeed, travelers through the air will probably start with as slight prepara- 20 tion as they now do for a railroad journey and with far les preparation than for an ocean voyage. In the huge circular station, built over a seaport, on airplane is shown about to land, a second is just startin on its flight, and a third is waiting for its new quota of passengers. The airplanes start from and alight upon platforms swinging on a circular railed bed high in the air. The itior ittle ¢ chi sta Ar ind a! ianes The

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ee ms ‘he Wtacee ve ORE aLS aaag ‘ike ep nepal ie Hae REE: June, 1921 Air in the Year 1930 a Se it be : i € t& itiorms are swung by two rotating arms, inclining a little downward, and moving with the wind, so that the achines always descend and ascend facing it —essential in starting and alighting. A monorailway penetrates to the heart of the terminal, and an elevator carries passengers to and from the air- planes. There is also a huge elevator for lowering the airplanes Drawing by Roderi to the ground-floor whenever they are in need of repairs. Such repairs are carried on in the interior of the struc ture, in workshops where scores of skilled mechanics work to make the machines safe for transporting the human freight —employing the most modern labor-saving ma- chinery, working at top speed, so that no unnecessary time may be wasted in an industry where every minute of idleness means financial loss 21 Hill

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The owner of this convex nose considered that it spoiled his looks You Can Now Have Your Nose Corrected I OES the shape of your nose satisfy you? Is it convex, con- cave, crooked, or flat and unshapely? [f you are not pleased with it, and if the fact makes you unhappy and mo- rose,, you can have the defect cor- rected without a scar. Dr. Julien Bourguet, of Paris, France, has developed the art of zwsthetic sur- gery and is able to give any one a nose approaching perfection. The opera- tions are performed without cutting the skin, and usually within two weeks afterward the patient can step outdoors with an improved appear- ance. The esthetic surgeon studies his patient’s nose with the eye of a sculptor. Experience at once shows what is wrong. With skill more deli- cate than a sculptor’s, the defect is eliminated. First,:local anesthesia produces in- sensibility to pain. The skin is then separated from the underlying frame- work, the operation being conducted through the nostrils. A miniature electric burr-saw, or surgeon’s hand- saw, cuts away the superfluous part of a convex nose. The skin is then allowed to readjust itself upon its im- proved support, and after about four- teen days the swelling disappears and the patient who formerly had, say, a convex nose now has a straight one. In correcting concave noses the cause of the depression is considered, and in some cases an injection of hard paraffin is made. This builds up the “‘depression’’ and restores the line of the nose to normal straightness. De- flected noses are operated upon accord- ing to the kind of deviation. If the whole nose is crooked, the bones them- selves are altered; but if there is only a slight deflection, the operation is more simple. But in any case the work is done from beneath the skin; no scar remains. The hump has been cut away from inside the nose A telescopic, two-sectional cane and a bundle are here converted into a tent Popular Science Monthly News by Parachute AVE you mailed your subscription to the Aerial Mail? If you want to keep in touch with what is going on in the air, you’d better get it in at once. Yes, the latest publication is a daily, edited and printed on board an airplane in flight. received by wireless, written, put into type, and printed on airplanes flying between London and Paris, so the edition must be printed in both English and French. Stock exchange reports receive special attention. How is the Aerial Mail distributed? parachutes, which drop appropriate editions over different towns. The news is By means of She Carries Her Tent in Her Hand HEN a girl walks down the street with a cane in one hand and asmall bundle in the other, she may be on a shopping-tour or she may be looking for a place to pitch her tent for the night. For that cane may be a collapsi- ble tent-pole and the bundle a tent. In the pictures to the left you see such a girl and such a tent. The ma- terial used in making the tent is very thin; thus when it is rolled up it makes a small bundle. It is, however, suffi- ciently strong to withstand hard wear. The cane consists of two telescoping sections that can be adjusted to any desired height. Hitch a Bungalow to Your Car “C\TOP at the Glenmore!”” At regular intervals you see this sign as you tour through the country; you decide to stop there. But when you arrive, weary and worn, you.find that the Glenmore is in the heart of the city on a noisy main street, or else that it is full. Glenn Curtiss and his brother-in- law, G. Carl Adams, have solved this tourist’s problem by inventing a bungalow-on wheels that is attached to the automobile, trailer fashion. It is well equipped, and yet is not heavy Take a bungalow with you when you tour. This one accommodates six people and contains all the comforts of home 22 The bungalow is mounted’ on two wheels located near the center. The front end is coupled to the automobile enough to cause an excessive strain. When you wish to sleep, eat, or rest, you stop the car in some convenient place and move into the bungalow. There you will find a kitchen, a pantry, a bathroom, clothes and _ bedding lockers, a table, chairs, and berths that will accommodate six people. The bungalow even has electric lights and running water. The windows are all properly screened and they are also provided with water-proof curtains. The bungalow is coupled to the auto- mobile by a bar. J1 ne, . NV. KE i eonsis nothin; than preg mounts zontall vertica You W rubber then 1 The te by the. propell straigh air. This copter, nautice a mach suppor upon s¢ a Fren¢ tov ma Langle: steam models the onl flew. Ther sons should vantag As ever plane 1 ground before alights. At car a

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June, 1921 NVERY one iB has seen a little toy consisting of nothing more than a screw propeller mounted _hori- zontally on a vertical stick. You wind up a rubber band and Straight Up from the Ground Oehmichen invents a new flyer By Henry Mathis Engineer of Arts and Manufactures, Paris correspondent of the Popular Science Monthly

HE fact that Oehmichen has used a balloon in ris- ing from the ground makes us question the validity of his results as Mr. Mathis presents them. No one will be convinced that a practical helicopter has been invented until it has flown without buoyant gas. In its present driven vertically by horizon- tal propellers. A successful helicopter must not only ascend straight up, but be able to descend slowly; it must be able to fly horizon- tally like an airplane; it must be stable. In _ our opinion, Oehmichen has not yet succeeded in solving the railway. This is a serious limita- tion in the com- mercial use of the airplane. <A helicopter, onthe other hand, rises straight from the ground, a roof or deck. Hardly a year passes but some then release it. The toy, driven by the horizontal

form Oehmichen’s helicopter is nothing but an airship highly important problem of stability.—Editor. inventor comes forth with a new helicopter. Not

propeller, rises straight into the alr. one has been suc- cessful, except

This toy is a true heli- copter, by which term aero- nautical engineers designate a machine that depends for support and_ propulsion upon screws alone. Pénaud, a Frenchman, invented this toy many years ago. Until Langley launched his small steam - driven airplane models in 1896, this toy was the only machine that ever flew. There are obvious rea- sons Why a_ helicopter should have enormous ad- vantages over an airplane. As every one knows, an air- plane must run along the ground for perhaps a hundred before it can fly, alights.

yards and also after it A very large flying-field is,

The screws of Oehmichen’s helicopter are really two wings of high efficiency, rotating in opposite directions therefore, required. Hence we find that passenger-carrying commercial airplanes cannot start from the heart of a city, but must fly from some outlying field reached by car or A balloon on a helicopter? But the inventor claims that it acts as a stabilizer, being capable of lifting only one fifth of the load, the balance being raised by the propellers

23 Oehmichen, a classmate of mine at the Ecole Centrale. Mr. Oehmichen is the first man who has ever risen from theground witha helicopter. The screws on which Oehmichen depends are two wings of high efficiency, ro- tating in opposite direc- tions. Their sustaining power is about 20 per cent greater than that of ordi- nary screws. Oehmichen’s first heli- copter models were either too heavy or mechanically imperfect. Then he in- vented the recuperating screws with which his pres- ent machine is equipped. Oehmichen’s helicopter weighs 572 pounds. The weight of the pilot is 167.2 pounds. The total weight is, therefore, 739.2 pounds. The appara- tus is surmounted by a stabilizing balloon with a gas capacity of 5083.2 cubic feet. The lifting power of this balloon is only 156.2 pounds, about one fifth of the total apparatus. The skeptic will at once argue: ‘“‘No wonder Oehmichen can rise from the ground with a balloon.’”’ But Oeh- michen retorts: “The balloon is merely a stabilizer, a device to restore the equilibrium of the helicopter if it tilts too far. It is able to lift only one fifth of the total load. The rest is lifted by the propellers.’’ In fact, Oehmichen intends to dispense with the balloon and use a smaller sta- bilizer. A two-cylinder twenty-five horse- power 1910 motor drives the screws. Yet the power of the engine is more than sufficient because the screws ab- sorbed only seventeen horsepower. The helicopter in test flights has risen to a height of nine feet.

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és In this electrically driven device for loading, it is merely necessary‘to push the pieces of cargo into empty slings as they move into position Endless Chains Load Ship DEVICE that rapidly elevates boxes, crates, loose barrels, and packed stuff to the necessary height to pass into a.cargo-carrier at the wharves, and then conveys the goods to the ship and deposits them in the hold of the vessel, has been invented by P. G. Popular Science: Monthly “Squirting” Concrete Piles ITH anew process of making concrete piles, a core is first built with tar paper and wire netting. The tar paper is wrapped around a paper core. Over this is placed a layer of wire netting. The wooden core is removed, leav- ing a cylinder made up of the paper and the netting. This is set in place, ready to be covered with concrete. The cement-gun is used to cover the form with concrete. The concrete mixture is forced through a hose under a pressure of thirty pounds to the square inch. The impact of the shot concrete gives a flintlike structure that is much more durable than poured con- crete. After a heavy layer of con- crete is squirted in place, the reinforc- ing rods are _ in- serted and the Squirting is con- tinued until the cor- rect diameter is at- tained. This method of building up _ pro- duces a stronger pile, since a hollow post is muchstrong- er than a solid one Donald, of London, England. The machine proper consists of a light structural steel frame, arranged to rest with one edge on the hatch coaming and with the other on the bulwark of the ship. ‘The steel fram- ing carries a series of rollers and gear- ing, by means of whieh two endless chains are supported and operated. These endless chains carry canvas slings between them in which the cargo is handled. These two chains are con- nected by cross traverses consisting of two tubes each, the inner one of which keeps the two chains in relative posi- These molds are made .of tar. paper and wire; after the mixture is squirted on, they will be concrete piles The mold partly covered, showing the reinforcing that is used between the first coat of concrete and the second tion while the outer tube is free on the inner one. The conveyor is driven by an electric motor that may be operated Automatic Drainage Gates surplus water to flow down into the by. any suitable engine. - Two. chain drives, one on each side of the con- veyor, are provided. The reason for having two chain drives instead of one is that the end driving spindle must not connect the upper sprocket wheels, in order to permit a free passage for the swings with their loads. The loading of boxes or cases on this conveyor is an exceedingly simple matter, it being merely néces- HE water-gate below is provided with a floating bucket, which fills as the water in the canal rises. This causes it to drop, and as it does so the “sheaves,” or large iron pulleys over which cables pass, rotate a steel bar to which other pulleys are attached. Cables passing over these sheaves are tied to the metal drainage gate, and it rises automatically. This permits the main irrigating canal, where it is car- ried away. The device can be fixed to any canal, and flooding from cloudbursts, or from the collapse of the banks of a lateral ditch, is amply provided for. Each gate in the canal which is not equipped with this device must be opened by hand by the ditch tender. sary to push successive pieces of cargo into the empty slings as they move into posi- tion to receive the pieces of freight. This system of loading takes the place of a num- ber of men, and performs the task with very little noise and very slight wear and tear or breakage to the goods as compared with the ordinary method of unloading by COUNTERWEIGHT AND caumdll | ADJUSTING PIPE I (SUDING SECTIO Inflammable Tubes for Fire Protection IRE protection can be easily secured by an im- proved tube device of in- flammable material. Put tubes in all dangerou places, and connect them b) piping to a main tank that holds a fire-extinguishing liquid. When fire breaks out means of cranes, although the crane is still far from be- coming obsolete. vice set to the desired level of the canal. which falls with the weight of water and lifts the gate 24 It enters a bucket, the tube will burn, and dow: will come the liquid, putting the fire out. Jun T been fictic pose that is he and loca’ Al met: from a Ge lieve pow: has he ec bow. aleol pou! is fic and met lid ¢ meti ing ¢ M =~ 2. Fy Fre ee

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be m- in- by ral ing wl ing June, 1921 The Scientific Divining-Rod HE bent old man with a divin- ing-rod in his hand has long been a fascinating figure both in fiction and in real Jife. He is sup- posed to have mysterious powers that cause the rod to bend when it is held over water or metal deposits, and thus indicates where they are located. Among those who believe that metal and water can be ‘‘divined”’ from aboveground is Mr. B. Jirotka, a German engineer; he does not be- lieve, however, that mysterious powers are necessary. In fact, he has invented an instrument which, he claims, will detect the radiation automatically. This instrument consists of a glass bowl into which some _ liquid— alcohol, acetone, or acetic ether—is poured. A glass or wooden needle is floated on the surface of the liquid, and one end of it is attached to a - metal rod that is fastened to the glass lid of the bowl. This lid, which her- metically seals the bowl, has a project- ing edge that is graduated. Mr. Jirotka claims that when metal He Opens His Suitcase and Takes Out—an Inflatable Boat This instrument, according to Mr. Jirotka, the inventor of it, can detect water and metal in the ground; in other words, it is a mechanical ‘‘divin- ing-rod”’ is placed on the edge of this lid the needJe within will be repelled; ores, coal, Joose quartz sand, chalky spar, and kerosene also repel the needle. The action is not instantaneous, but occurs after a few minutes. Different materials will affect the needle differ- ently. Sometimes the radiation is Leaving the suitcase on shore, he goes out. in his boat; he stops paddling ' occasionally to pump up the side bags The “rod” consists of a giass bowl filled with alcohol in which floats a sensitive wooden needle strong enough to turn the needle around through 180 degrees, thus bringing it opposite the material. Water and moist earth, says Mr. Jirotka, have the opposite effect on the needle; they attract it. So do certain salts. And the colder these attractive things are, the greater the attraction; whereas the colder the repelling things are, the less the at- traction. But all these claims of what is de- clared to be a new radiation, must be verified by a scientific investigation before being accepted by scientists and the public at large. After a trip the bags are deflated; then the boat is taken apart and put back in the suitcase The boat is being put together for another trip. After the bags are pumped up, they are attached to a wooden frame 25 . No larger than an ordinary suitcase is the one that holds the collapsib'e boat. Its contents are not heavy

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A LMA” is the stage name of the French cruiser that is the victim of German treachery in the dramatic play ‘In the Night Watch.” As the curtain goes up for the first time, you see the deck of the Alma gaily decorated with Japanese lanterns; you hear music; there’s a dance on board. Among those present are the captain, his wife, and two designing officers. Thus the eternal triangle is turned into a rectangle. The captain receives a_ wireless message: ‘‘War with Germany has been declared.’’ For the sake of his wife he tells the guests that peace is assured. He soon sends them to shore, however, and immediately tells his men the truth. The decks are stripped for action and the vessel moves. As the curtain falls you have an uneasy feeling that the captain’s wife, who is in love with one of the officers, is still on board. You discover later that you were right. And now for the battle. In the second act you see the Alma riding the waves. A strange ship is sighted. Our hero, the captain, orders secret signals to be flashed. The strange ship gives SETTING OFF FLASH POWDER, PRODUCING EFFECT OF HIT WATER LINE a | Staging a Realistic Naval Battle In which the audience sees a huge cruiser explode and sink By Philip Schwarzbach the correct reply; this is repeated several times as the mysterious ship approaches. You see the ship turn about. Then the lights go out. In- stantly the firing begins. The Alma returns shot for shot. Suddenly she is fatally hit by atorpedo. Thecaptainis wounded, but he carries on, ordering the life-boats to be launched. The semi-villain with whom the captain’s wife is in love turns hero and straps his own life-belt around the wounded captain. Next you see the actual sinking. As the huge ship takes her final plunge the boilers burst and steam roars up- ward. Gradually the steam disap- pears, and you see a small life-boat in the distance. And its passengers? A man and a woman. And now comes the last act—the court martial. The only known sur- vivors of the Alma are the captain, the real villain, and the sailor who attended the villain-hero. The cap- tain is unable to prove that the enemy ship answered his signals correctly. The villain denies having seen them, and then at the crucial moment the penitent wife appears and it all ends happily. Popular Science Monthly The Alma is nothing but a well painted piece of canvas mounted on a wooden frame. It slides down through a slot in the floor. A shot- gun and escaping steam imitate the explosion of the ship’s boilers June, . _—_—_—_ = Here you see the back of the enemy Si moen As the enemy vessel appears to ap- proach, a larger ship is substituted for PORT LIGHT N RED ship as it first appears on the horizon. ™_ It is mounted on a pedestal and is operated by one man. He the small one. This larger ship is made in three sections— sha: pushes it slowly across the floor to give the effect of an bow, stern and midship. Each section is mounted in a and approaching ship. groove and is controlled by a rope that winds around a wind- —a When the stage-manager first flashes the cue light, the man lass. The midship section has a red and a green light’at each cha behind the ship presses a button that controls the answering end. The red shows first. When the ship appears to be iber signal to the French ship. All the other operations—signals turning around, the bow and stern section are telescoped bar and flashes as the shots are fired—are handled in the same _ behind the midship section and the lights are changed from mal way. The stage-manager has his cue booth at the side of red to green and red. Then as the telescoping sections are res} the stage in front extended again the green light shows the

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June, 1921 yOoO1OD ; eittch a2 CHIEF ELECTRICIAN GREEN GAUZE DROP The explosions that shake the vessels — and also the theater —are made by dis- charging large-cal- iber shotguns into barrels. The stage- manager, again, is responsible for giving the cues BACK CURTAIN { CHAIN + DROPS TO | IMITATE. TORPEDO » CRASH ri “i ’ 4S MORSE iv SIGNALS SEMAPHORE CLOUD CYCLORAMA ENEMY SHIP © sTHREE SMALL 7 fam RIPPLE DROPS es Ls oa se GROUND CLOTH Torpedoing a Stage Cruiser Above you see what is going on behind the scenes when the cruiser Alma meets the enemy ship. The AJma—or rather the small part of her that the audi ence sees—is mounted on rock- ers. Several men work to- gether, pulling the end of the rockers up and down, thus giv- ing the effect of a ship riding rough waves. The waves, by 27 the way, are made by playing “ripple light’? on three small drops located between the Alma and the enemy ship. These drops vary in height, and are topped by wire that makes then blend. Clouds that move across the sky throughout the first act are made by a light-machine in a similar manner

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Popular Science Monthly Spraying the Chicken-Coops to Kill Mites HICKENS infested with mites or other parasites are not good layers. Eternal vigilance is the price of a good egg crop. The diminutive sprayer, penetrating the corners and crevices of an infested poultry- house, is effective where only a small flock of chickens is maintained. The spraying is done at varying angles in all the corners of the poultry-house, and then the weapon is directed to the floor. The roosts must be taken down and boards and boxes removed. Crude petroleum is effective in the eradication of chicken pests, the insecticide consisting of one part of kerosene to four parts of crude oil. Rock and Keep Cool QO’ a very hot summer day, the mere ex- ertion of rocking will make you un- comfortably warm. One inventor decided that he was going to enjoy rocking and yet remain cool; so he made a fan operated by the motion of the rocker. The movement of the chair causes a large gear wheel to revolve. Meshing with this large gear isa pinion. A fan is mounted on the shaft with the pinion, and this is set into motion when the chair is rocked. A delightfully cool breeze results and the comfort of rocking can be enjoyed however hard old Sol tries to heat up your part of this planet. Holding Up the Box-Cover ROVING that simple patents pay well, we illustrate one that has made money for its inventor. This is a holder for the cigar-box. It is so made that it fits over the back and side of the box. Extending from the lower sec- tion is a small wire. When the box is opened this wire springs into place against the cover and holds it open. The cigar clerk will tell you that it helps him in the day’s work. The Man of Bulak HE wooden image in the picture below is not unlike some of the men you see to-day; and yet, that image was made cen- turies ago. Men have not changed much with the times. The statue is known as “‘The Man of Bulak,’”’ and is now in a museum in Cairo. It is supposed to represent a village chief and it dates back to prehistoric times. The even temperature and the dry climate in northern Egypt have helped to preserve it. Many archeologists believe this to be the oldest statue in existence. Comb the Cranberry Bushes for Efficiency ERE is a quick way of taking cran- berries from the bushes. Comb them off. The device used is both a comb and a scoop. The comb takes the berries from the vines and the scoop holds them. It is not long since berries were picked entirely by hand—a slow, costly job. Then came the comb and more speed. If the scoop is used carefully, the berry bushes will not be injured in the least. Instructors Travel to Students F plans of Hawaiian educators are car- ried out, pupils will have their education brought to their very door. Application for a Pan-American university charter has been made, with ‘“‘classrooms’”’ in the pine- apple and sugar fields throughout the ter- ritory of Hawaii. The first work of the kind is to be carried on in the labor camps of the islands. Steel for the Concrete Road OARDS used to be used as forms for road concrete. They were unsatis- factory in every way. They would warp, leak, and break, causing imperfections in the road. Then came the steel forms real helps and time-savers. The steel forms may be put in place in a short time. They are automatically attached to pedestal supports, which are held to the ground by steel stakes. The steel forms hold their shape and they may be used over and over again. on 22 June, This MM : h and th pearan all to heels | will gi longer Thes motion conseq: and un Such the cer the she a way with th It is will no weathe Two \ HE hors differen: ponies : between The p the smal into the partner, the ma stands | Once horse—t He was there is x pony pic This to type, probably parents.

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June, 1921 This Heel Rotates When You Walk OST of us wear down the 4 heels of our shoes unevenly and this gives us an untidy ap- pearance. Hence it behooves us all to wear revolving rubber heels like the one below, which will give your shoes a much longer life. These heels are constantly in motion when you walk, and in consequence they wear slowly and uniformly. Such a heel is screwed through the center to the leather heel of the shoe, being attached in such a way that it coincides exactly with the sides of the heel. It is claimed that the heel will not skid in the rainiest of weather. An Emerald that Weighs Four Ounces BLOCK of wood—that’s what you think the hand below is holding; it’s too regular to be a stone and too large to be a jewel. But it is a jewel; an uncut emerald weighing six hundred and thirty carats, or about four ounces. It measures two and five eighths inches from end to end. This is said to be the largest emerald mined since the days when Cortes invaded Mexico; however, it is not nearly so heavy as some emeralds in exist- ence. In Bogota there is a thousand-carat emerald. The new emerald is to be cut up into small stones. Two Very Different Members of the Horse Family HE difference between a pony and a horse is the size—and sometimes this difference- is .very -great.* In fact,- some? ponies are so small that they can walk between a horse’s legs without bumping. The pony shown in the picture below is the smallest of them all; hence, he has gone into the theatrical business. He and his partner, the big white horse, are under the management of the woman who stands by. Once upon a time there was a five-toed horse—the ancestor of the modern horse. : He was not much bigger than a dog, so that there is nothing scientifically new about the pony pictured. : This pony is clearly not a reversion to type, but merely a freak of nature, probably caused by some defect in the parents. Putting the Porch on Top N California an architect has over- topped convention and built a house with an attractive porch on the roof. After all, what is a porch for? It is a place where family and friends can gather at leisure hours, or in the quiet of the evening. It should be a cool place, if the house is built in a warm locality. From the higher levels of the structure a better view can be obtained, and if a breeze is stirring, one will surely get it better from the roof than from the ground. This particular roof-porch adds greatly to the charm of the design of the house. Artificial Wool a Failure ALTHOUGH the director of the chem- 4 ico-physical section of the Research Institute for the Textile Industry at Dresden personally supervised experiments toward artificial wool, he has pronounced his efforts a failure. The process consisted of compressing wool scraps otherwise worthless—short fibers, ends, shreds, etc.—after treating them with certain chemical solutions. It was found that on putting this wool in solution it decomposed. t Put a Sieve on the End of the Watering-Hose EXT time you spray the garden, notice the shape the water takes as it leaves the nozzle. You will see that it is hollow and cone-shaped. Centrifu- gal force may be blamed for the hollow- ness. A full spray would be better for the flowers and plants, and now there is a de- vice that, when attached to the nozzle, will produce this. It is a small flat wire sieve mounted on a holder that keeps it at a dis- tance of about two inches from the nozzle. When the whirling spray shoots out of the nozzle, it hits the sieve, is broken up, and continues on its journey as if it were com- ing out of a watering-can, and in addition waters more plants as it sprays, albeit the water falls more gently. Joseph W. Burbank, of Albany, New York, is the inventor.

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Ice Bought by Slot-Machine N the illustration above is shown a ma- chine for ordering ice. The housewife decides the amount of ice that will be needed for the day. Going to the little slot-machine that hangs on the porch wall, she slips a coin or a ticket in the slot, then unlocks an indicator that tells how much ice is wanted. Along comes the iceman, fills the order, unlocks the box containjng the coin or ticket, which. action automatically with- draws the indicator, and by pushing down a knob at the top of the machine he Jocks it, leaving it ready for the next order. Where Fish Is Cleaned on the Pier ISHERMEN who catch fish from the pier at Santa Monica, California, need not worry about the cleaning of the catch when they arrive home. No more will there be that domestic lecture that removes all of the joy from a perfect fishing day. This Pacific coast city has equipped its pier with running water and sinks for fishermen who wish to clean their fish where it is made most convenient. What fisherman would not gladly clean his catch in such comfort—not mentioning the view? Such considerations cause residents to feel justly proud of their community and take an interest in its welfare and public events. His Right Hind Leg Is of Wood NCE there was a dog, and it had a wooden leg. This is not a fable, but an actual fact. The dog was run over by an automobile, and one of its hind legs had to be ampu- tated. A three-legged dog doesn’t stand much chance in this world; hence the dog’s kind mistress had a fourth leg made for it. In a very short time the dog learned to use it deftly. The wooden leg is covered with white cloth, and is, alas, very conspicuous, since the dog’s hair is grayish brown. Killing the Flea-Beetle HIEF enemy of tobacco-growers is the flea-beetle. In one season it did six hundred dollars’ worth of damage an acre in the tobaceo fields of Florida. Now there is a machine that scatters poisonous dust on tobacco plants—from eight to twenty pounds to the acre. The machine is drawn between the rows of plants while a fan on it blows quantities of dust through a pipe. The force is so great that the dust scatters over four or five rows. A gasoline engine operates the ma- chine. The dust is half calcium arsenate and half tobacco dust. Popular Science Monthly Megaphone, Fan, and Hat ARD it is to imagine anything that will recommend itself more readily to the heart of the con- firmed football, baseball, or basket- ball rooter than this three-in-one megaphone. Should your team be winning, the megaphone will carry your joy to the field. Should they be losing, it will convey encouragement. But that is not all. During the inter- mission the same megaphone, folded, be- comes a fan to cool the fevered brow of the enthusiast. The game won, the mega- phone becomes a hat. How a Road Was Saved by Jacking It Up Aree heavy rains had washed out the sandy subgrade of a section of high- way in New Mexico, leaving the concret« slabs with but frail support, an engineer of the Bureau of Public Roads quickly adopted the novel procedure of jacking up the roadbed, and rammed wet sand into the dugouts to support the concrete slabs. The collapse of the pavement was averted, and the concrete slabs were re- stored to their former bed without crack or flaw. Until the sandy subgrade could be rebuilt the washed shoulders of the road were protected with brush as a precaution against another gully-washing rain. The gaps in the subgrade were rapidly refilled Da June, — « t i H Fatte AT thar who st market leave chance To ] by exe! it has } expedit are fol holds down 3 food e tube in The the qu pendin other f; T UR The possible ease, var Cage window above, Spoo startlec are pla ones b how m: nothing are so } balance How prisone mealtir service, Taare

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Fattening Chickens by Machine AT chickens command higher prices than lean chickens. Chicken breeders who supply broilers and roasters for the market know this, and are not willing to leave the fattening of their chickens to chance. To prevent the bird from using up fat by exercise, it is kept in a coop so small that it has practically no room for exercise. To expedite the fattening process the birds are forcibly fed by machine. One man holds the chicken while another presses down a lever and forces a quantity of the food contained in a tank through a rubber tube into the mouth of the chicken. The birds are thus fed three times a day, the quantity of food forced into them de- pending upon their condition, age, and other factors. Towers Made of Turtles and Spools

URTLES are not acrobats by nature. Their clumsy hard shells make it im- | possible for them to twist and turn with ease. A London shopkeeper took ad- of this fact and placed in his the three turtle towers shown vantage window aboy e, Spools of various sizes support the startled turtles in air. The larger animals are placed at the bottom and the smaller ones become upper stories. No matter how madly they wave their feet in the air, nothing happens to the towers; the shells are so hard and firm that they are not un- balanced by the motion of the feet. llow does the shopkeeper feed his prisoners? Unless he releases them at mealtime, he must give them individual service, feeding them one by one.

19097 T.wmea

Protection from the Live Wires by Special Apparatus EATH lurks in these wires. are repairing live wires. them ‘‘hot.’” When they are “hot,”’ they are dangerous, and the lineman must watch his step andhis hand. The platform is insulated so that it helps the lineman to keep safe. A wooden shield is also placed over the wire so that acci- dental contact through slipping or falling is remote. The flat form and the wooden supports are made of a moisture-proof wood that is a fairly good insulator of electricity, The men They call Metal Lighter than Aluminum pyfACniesrum is an extremely light metal and it has little mechanical strength. It is about one third lighter than aluminum. The metallurgist has succeeded in alloy- ing this cousin of aluminum with other metals that impart to it the proper degree oi tensile strength. The resulting alloy is, however, ninety per cent magnesium. This makes it a very light alloy with ideal physical properties. It machines nicely, has a low coefficient of expansion, is tough, hard, and well able to resist wear.

Cook with Gas in Camp HOSE who have gone camping with a smoky oil-stove or an alcohol lamp will appreciate the convenience of this little acetylene burner. The coffee-pot in the picture above sug- gests breakfast, with flapjacks on the side The little cooking outfit, however, is equally useful for preparing other meals, and one can imagine very good soups and sauces. The acetylene burner is just as practical as the gas-stove at home. . The gas is carried under high pressure in a small tank, and the supply is sufficient to cook many meals. The tank is light and portable and the entire outfit does not weigh as much'as a supply of oil or aleohol that would last the same length of time. Could You Assemble These Parts into a Box?

ONSTRUCTING a square box is usually a simple mat- ter. Here is a box that, although all the parts ar® finished, it is almost impossible to assemble. The box has been in ex istence in an English family for more thar a hundred years, and is said to be the only box of its kind in existence, and yet very few people have ever been able to put it together; and some of them have worked on it for months. Of course the box is elaborate in con- struction. There are twenty-four edge pieces that must be properly joined to- gether, and it is there that the difficulty lies, since the sides, top, and bottom logi- cally fall into place.

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© Modern Publishing Company The Wonderful New Process Whereas sterilization by pasteurizing milk is often non- effective, recent experiments by three British scientists seem to prove that electricity solves the problem. Sam- ples of milk treated electrically, taken on fifteen successive days, failed to disclose any trace of typhoid germs; and milk that had been infected with tubercular germs was also cleared by electricity. The picture shows how the apparatus for electrically treating milk works. Atank receives the raw milk, and this is connected by a pipe with a constant-level tank, which maintains a uniform pressure. From this the milk is led to the ‘‘lethal tube,’’ a section of which is glass, with inter- mediate electrode chambers. As the milk passes out of Popular Science Monthly Drawing by G. A. Davis that Kills the Germs in Milk this tube, its temperature is registered by a thermometer, after which it flows into the auxiliary tanks. These are alternately filled and discharged into a covered channel, which in turn discharges into the tank for treated milk. These tanks might be called ‘‘safety’”’ tanks, since, in case of a mishap to the apparatus, such as failure of the electric supply, the untreated milk may be returned to the over- head tank for re-treatment. Electric sterilization destroys not only typhoid and tubercular germs, but also those that are harmless. There is naturally some question as to whether it is wise to de- prive milk of a property that is not yet thoroughly understood BN terla tuber all ki rate 0 eonsu No sterili effect termi phoid prove tion secur treat! A esting has b by P Beatt Lewis Unive fesso ming possi jze th ods o expe stage can s A samp days, milk typhe cows infee also k the «¢ was ( pigs treat Thos milk inoe milk the mair Ar trica of th As snow

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June, 1921 Electricity to Keep Milk Fresh for Weeks Three English scientists discover a new sterilization process ILK is pasteurized by M heating it. The object 4 is to destroy injurious bac- teria that cause typhoid fever and tuberculosis. Unless these bacteria are all killed, the survivors multiply at a rate beyond belief, and the risk to the consumer is proportionately enhanced. Now, whereas present methods of sterilization fail to effect complete ex- By P. J. Risdon English correspondent of the Popular Science Monthly for receiving untreated milk, connected by a pipe and tap to a constant level tank. The latter is fitted with a ball valve, which maintains a uniform head or pressure. A pipe with a control tap view of the copper electrodes and electrode chambers. All contact surfaces are encased in vul- canite. Many experiments were necessary to ascertain the exact class and strength of current, the diameter and length of tube required, and the quantity and rate of flow of the milk, as all these things must be correctly proportioned. The termination of ty- phoid germs, it has proved beyond ques- tion that it can be secured by electric treatment. A series of inter- esting experiments has been carried out by Professors J. M. Beattie and F. C. Lewis, of Liverpool University, and Pro- fessor Leith at Bir- mingham,which may Must Pasteurizing Go? CIENTISTS long ago convinced legislators and the public of the necessity of sterilizing milk to de- stroy the germs that flourish in it. the germs, sterilization by the usual method—pasteur- ization—has the terrible effect of speeding up their multiplication. Recently three British scientists made experiments in sterilizing milk electrically, and the results may completely revolutionize the present method. Unless it kills all plant at Liverpool, which for three months treated the milk for the Liver- pool Corporation in- fant-welfare centers, had a capacity of 30 gallons of milk an hour. An alternating current of about 4000 volts and 2 am- peres was employed, which raised the temperature of the milk to 63-64° C., possibly revolution- ize the present meth- ods of sterilizing milk. Although their experiments have not reached a final stage, the importance of the results can scarcely be exaggerated. Among other instances and proofs, samples, taken on fifteen successive days, of electrically treated ‘‘control”’ milk failed to disclose any trace of typhoid germs. Milk from tubercular cows and milk deliberately and heavily infected with tubercular germs have also been entirely cleared, proving that the destruction of injurious bacteria was complete. In other tests guinea- pigs were inoculated with electrically treated and untreated infected milk. Those inoculated with unsterilized milk developed tuberculosis; those inoculated with electrically treated milk remained perfectly healthy. Milk Kept Sweet for Two Weeks In addition to destroying the germs of typhoid and tuberculosis, electric treatment destroys 99.9 per cent of harmless bacteria. Milk so treated, especially if rapidly cooled, can be kept in an ordinary room at ordinary temperatures for several days without deterioration. In one or two instances it has remained sweet for a fortnight. All the other essential ingredients of the milk, such as fat, sugar, etc., re- main unaltered in quantity and quality. An important feature of the elec- trical process is the practical character of the apparatus employed. As the picture on the opposite page shows, the apparatus comprises a tank leads downward to the ‘‘lethal tube.” Short sections of aluminum tube are introduced for ‘earthing’? purposes. A section of the lethal tube is of glass, with intermediate electrode chambers. As the milk passes out of the lethal tube, its temperature is registered by thermometer, after which it flows into auxiliary tanks. These tanks are alternately filled and discharged into a covered channel, which in turn discharges into the main receiving tank for treated milk. The object of the two auxiliary receiving tanks is that, in the event of mishap, such as failure of the electric supply or the accidental switching off of the current, untreated milk may be prevented from entering the main receiving tank and may be returned to the overhead tank for subsequent treatment, while the auxiliary tank is sterilized. The diagram of the electrical appa- ratus is almost self-explanatory. The transformer is for raising the voltage of an ordinary low-pressure supply current, and the aluminum tubes are for “‘earthing’’ purposes. As the milk flows through the lethal tube the high- pressure electric current passes into it from the electrodes, out through the aluminum tubes to the earthing plate, the earthing arrangements being neces- sary for the protection of the opera- tors. Thus every portion of the milk as it flows through the lethal chamber is equally exposed to the influence of the current for a matter of some fif- teen or sixteen seconds. At the top of page 32 is an enlarged 33 (148°F.). This vol- tage and tempera- ture proved the most satisfactory; it is sufficient to destroy all harmful bacteria and 99.9 per cent of other bacteria. A temperature of 70° C. was tried, but was found to effect undesirable chemi- cal changes. Moreover, too much cur- rent was consumed. Should All Bacteria Be Destroyed ? Direct current was experimented with, but gave no satisfactory re- sults. When starting up the plant, the milk is allowed to escape for a few minutes until everything is working correctly. Then the outflow is di- verted into the auxiliary receiving tanks and the escaped portion is re- turned to an overhead tank. A refrigerating plant is an almost essential adjunct. It has been found that, by rapidly cooling the milk after electric treatment, it remains sweet for a longer period. Skilful supervision and scrupulous cleanliness are of course essential, both during sterilization and in the subse- quent handling of milk. The question arises: Is it advisable to destroy admittedly harmless bac- teria that presumably give milk “‘live’’ qualities that Nature has decreed it shall possess? It seems indeed to open up a prospect for synthetic milk. One cannot help wishing that means could be devised for destroy- ing harmful germs without depriving milk of a property that is not fully understood.

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Popular Science Monthly Bowling the Jack on the Green The game introduced on New York’s Bowling Green in 1732 has lately been revived in several American cities a EXT stop, Bowling Green!” Few ofthe passen- gers who hear the New York subway guard shout out this station, know or even wonder why the com- paratively small patch of grass at which the train will stop is called ‘“‘Bowling Green.” That patch received its name in the year 1732, when three men — John Chamber, Peter Bayard, and Peter Jay—leased it for the large sum of one peppercorn a year. They fenced it in, laid it out, and bowled on it regularly. In those days bowling was done outdoors in fair warm weather, and indoor alleys were Now, however, there are very few bowling- greens in this country; but the old out- door game of bowls is still played in used in the wintertime only. New York city by enthusiasts. Outdoor bowling is very dif- ferent from the indoor sport. A full-sized bowling-green is one hundred and twenty-six feet square, and it is divided into six or eight rinks. A shal- low ditch fourteen inches wide surrounds the green, and be- yond the ditch there is an em- bankment two and one half feet high. Instead of ten pins, a single “jack” is used. This jack is a white earthenware ball, two inches in diameter. The oppos- ing players, or teams, toss up, and the winner stands on the mat at one end of the first rink. He hurls the jack down the When it has stopped green. The team whose players roll their bowls mearest to the small white jack wins By Philip Schwarzbach To-day the Bowling Green section of New York city is crowded with skyscrapers; but in 1760 it was a real bowling-green, as this old print shows rolling, it is placed in the center of the green at that point—provided it is at least seventy-five feet from the mat. Should the jack roll into the ditch, it is placed six feet from the edge. Then the bowling begins. The players try to hurl their balls— or bowls, as they are called—as near to the jack as possible. If there are The last shot has just been fired. In order to save his team from defeat, he was forced to trail the jack back to where his partners’ bowls were several players on each side, the first players must be careful not to block up the passage and thereby hinder their partners. Four men usually play on each team, the captain of the team being the last one to hurl. Each man hurls two bowls on each rink. When the playing is finished on one rink and the score computed, the players move on to the next. Twenty-one ends are a game. Each man on a team must be trained to use different tactics. The first man up must be 34 ‘a good judge of distance, and must hurl his bowl so that it lands very near the jack. The last man up may be called upon to trail the jack back to where his partners’ bowis are. This requires a keen eye and a steady hand. Very often the entire game depends on _ the placing of the jack. Re- cently a Canadian team played in England, where the greens are longer than those in Canada. When- ever an Englishman hurled the jack he sent it so far down the green that the Canadians were unable to score. It was because of this skilful jack- placing that the Canadians lost most of their games. As for the bowls themselves, they are not perfectly round, as in the case of the indoor bowl. Instead, they are more rounded on one side than on the other; hence they follow a curved path up the rink. The first bowls made were of stone, but they proved to be too heavy and not swift enough. They were replaced by wooden bowls that were weighted down to give the proper bias. Now, however, this is accomplished by the peculiar way in which the wood is turned. There is a number indicating the degree of curvature painted on the side of each bowl. If the bowl is held so that the number is near After the jack is placed, the players go to the mat in turn, and bowl E MOA MAP RIT CM BANKMENT 5 ms DD p—— MARKER the curv whe the | ever depe play page it step toa sure, used. prope tensi It j fill a withc face 1 insect out w Wk A sor No “pum thin n cells, This Way 0O paper direct: The bi by me bent r leathe rangec being | to be ] is driv As t Surface cells a are lift the wa vents 1 out. | ing bel cells Sl the to

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mH Ss ve st ire ise ey ide ey she of Role) gh. len wn OW, hed ‘ich is a rTee side 1 is lear ——ae ’ LT ee June, 1921 DIAGRAM OF A BOWLING-GREEN MARKER A full-sized bowling-green is 126 feet square, divided into six or eight rinks. A shallow ditch surrounds the green, and beyond that an embankment the little finger of the hand, it will curve toward the right side of the rink; when the number is near the thumb, the bowl will curve to the left. How- ever, the path that the bowl follows depends largely on the skill of the player. The pictures shown on these two pages were taken recently at the bowling-green in Prospect. Park, Brooklyn, New York. The game has also been revived in Boston, Detroit, Buffalo, Hartford, Pawtucket, and in a large number of villages along the Canadian border. When did the game first appear in history? Herodotus mentions the fact that the Lydians bowled strenuously The wooden bowl that is used. One half of it is rounder than the other, so that when the bowl is released, it fol- lows a curved path Water “Pumped” with an Endless Belt HE ingenious French engineer, Canuelle, has madearevolutionary step forward in the art of lifting water to a higher level. No pump, air pres- sure, vacuum, buckets, or pipes are used. Advantage is taken of the property of liquids known as surface tension. It is surface tension that allows us to fill a glass with water above the rim without overflowing, and sur- face tension that enables an insect to skate on water with- out wetting itself. What is surface tension? — A sort of intangible ‘‘skin.”’ Now, let us see how this new “pump” works. A strip of thin metal is bent to form little cells, as shown in the picture. This is made similar to the way one would take a strip of paper and bend it first in one direction and then in the other. The bending is, of course, done by machine. Rivets hold the bent metal strip to an endless leather belt. The belt is ar- ranged over two pulleys, one being submerged in the water to be lifted. The other pulley is driven by hand or motor. As the belt passes under the surface of the water, the little cells are filled. When these are lifted above the surface of the water, surface tension pre- vents the water from flowing out. When the rapidly mov- force ruptures the surface film and the water is thrown off into whatever receptacle is used. The size of the cells must not be too large, since surface tension will be effective only with small areas. If a larger quantity of water is required, another row of cells is added to the first row; even several rows can be added. ing belt with its water-filled cells suddenly swings around top pulley, the centrifugal An endless belt with small metal cells attached to its surface forms the lifting element of this unique “pump”; the principle upon which it works is known as “‘surface tension’’ 35 ‘that it when food was searce. It made them forget their hunger. Again, at the time of the Spanish Armada, bowling was the fad. Sir Francis Drake, it ap- pears, was bowling at the time the Spanish Armada was sighted off Corn- wall. When the news was brought to him, he said: ‘There is plenty of time both to win the game and beat the Spaniards.”’ Even John Calvin, the celebrated theologian, is reported to have played a’ quiet game of bowls on a Sunday afternoon! John Knox—tradition has it—discovered him in the act one time at Geneva. Sir Isaac Newton was another bowl- ing enthusiast. His niece wrote of *him: “In the warmest pursuit of his discoveries he, going out, left a candle upon his table amongst his papers; he went down into the bowling-green of Trinity College, Cambridge, and meet- ing somebody who diverted him from returning as he intended, the candle set fire to his papers and he could never recover them.”’ Repairing a Hydraulic Elevator Pump NE of the elevators in a New York skyscraper was recently put out of commission by the breaking of a hy- draulic pump casting. On examina- tion it was found that the metal casing was badly cracked in four places, the breaks penetrating clear through the shell, and extending five or six inches. The damage was so serious that it was thought an entirely new casting would be required. When it was found, however, that replacement would cost eighteen hundred dollars, and that it could not be done without serious delay, an oxyacetylene-welding firm was consulted. On reporting favorably, the welders were put to work. The chief problem was ventilation. The repair had to be made in the pump room and was one requiring thorough preheating. The pump oc- cupied a space in the basement under the elevator shaft, where, if special ventilation were not provided, the gases from the charcoal would seri- ously affect the welder. This diffi- culty was overcome by connecting the building’s ventilating apparatus so drew off the fumes. The cramped space in which the work had to be carried out also made it difficult. The actual time of the job, including preheating and welding, was sixteen hours—two welders working in relay. Approximately thirty pounds of weld- ing-rods were used in filling in and building up the welds. The casting, after repair, was subjected to one hundred and sixty pounds per square inch working pressure, and is to-day as good as new.

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Taking the Shock Out of Docking Popular Science Monthly O matter how careful or experienced a ship pilot may be, it is impossible to dock a large vessel—or a small one, for that matter— without striking and rubbing the dock. This causes dam- age to both the dock and the vessel. In the case of a big, heavy vessel, the dock is apt to be displaced several inches, and if every vessel that docks causes a like amount of displacement, it will not be long before great damage has been wrought. In striking and rubbing the dock, the ship also suffers strains that will in time necessitate a trip to the dry- dock. This is the way in which Lee Larsen, an inventor, would eliminate the trouble of docking. He would place huge ball-bearings along the edge of the dock. These large ball-bearings would rest against smaller ones in such a manner that the larger bearing would revolve with very little friction. When the ship’s side came in contact with the ball-bearings, friction would be prac- tically nil. The shock of the impact would be absorbed by heavy springs mounted at the back of each ball- bearing. Rising tides may come and BUFFER- @ The spring bumper ALL- ee SPRING | ce road cars saves both the ship R . hae and the dock from glide off instead of swinging over to damage throughrub- the other side of the slip as it bing and bumping. Here it is in use plied to docks. The big spring is similar x ; ne Po eae rail. that would be saved in repairs to the go, winds may blow, and the pilot may get just a bit care- less; but neither the ship no: the dock will suffer in th: least when these dock “‘bumpers”’ are in use. This spring bumper woul be a great help to the ferry boat pilots. If the slip was provided with such attach- ments, they would save th: boat and the piling from damage. In rivers where : swift current is flowing, it is « very difficult matter to pull a big heavy ferry-boat into the slip without striking the piling. With the ball-spring bumpers a boat could strike the piling without any great danger, since it would merely does now. There is no reason why a vessel could not be equipped with these spring bumpers instead of having them placed on the docks. A vessel so equipped could stop at any pier or dock without This shows the con- danger of accident. HOUSING struction of the The cost of making such an attach- bumper as it is ap- ment would not be prohibitive and it would soon pay for itself in the money ship and damage to the docks. This Instrument Plants Hair ARDENERS lacerate the soil of a barren plot, insert some seeds, take a sprinkling-pot, and with a little eare bring forth an abundance of soft green grass to delight the eye. Ac- cording to a record from the patent office, attempts are ever being made to make the desert of a bald head blossom with a crop of new hair. Have any of these patents special merit? Is the task of growing hair as easy as that of raising grass on the lawn? The nearest analogy is that of an in- strument constructed for the purpose of planting hair in the human scalp. The hair, after being sterilized, is placed in a tube and mechanically guided into the part of the instrument that feeds it into the skin. A part of the operation less appeal- ing to the timorous is the method by which the hair is inserted in the scalp. The apparatus has an implement provided with means for puncturing the skin, spreading the punctured opening sufficiently to admit insertion of the hair, retracting the puncturing needle, and severing the inserted sec- tion trom the main hair section. In general, a less brave person might submit to a genuine old-fashioned scalping by Indians, were it not for the fact that in one case he is promised a better- looking appearance by the addition of a head of hair, while in the other he is de- prived entirely of this acquisi- tion to his vanity, not to mention the loss of «his life, liberty, and the pursuit of happiness. GLASS TUBE FLEXIBLE SHAFT a R (FROM MOTOR) A promising _hair- planting instrument. As it moves along the bald head it makes minute openings in the skin, while hair is thus automatic- if ) lly ‘‘planted”’ / weft | HAIR- 1 ee ‘) WW INSERTING HAIR FEEDERS DLE This instrument is just as effective—-perhaps a little more so—on scalps absolutely bald as it is on those partially so 36 June T pour shoo! trick crack men and { tong! lack Th tor § whal actre selve cano “seet Th man¢ Univ town and volea To “moy in tl long equa. of th oe =n cal This is attache the ro earthqn work a Stage t!

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Pip str 7” June, 1921 An Earthquake to Order HERE was a flare on the crest of the voleano. A red destruction poured through the forests, the earth chook violently, and the seething lava trickled down the hillsides. Great cracks opened in the earth, swallowing men and women. Buildings staggered and fell in clouds of dust, and crimson tongues of flame burst through the ‘lackness of the night. Then all was quiet—until the direc- tor shouted: ‘Great! That was a whale of a job!’ Excited actors and actresses then started to dig them- selves out, the ‘‘red flare on the vol- cano” was extinguished, and the “seething lava’’ was turned off. The story, “The Fire Cat,” a ro- mance of South America, filmed by the Universal Company, required that a town be demolished by an earthquake and then flooded with lava from a voleano. To produce the earthquake the “movie” engineers cut a jagged slice in the earth a quarter of a mile long and ten feet deep. Under ten equally divided sections of one side of the slice were placed sliding plat- forms. At this stage of the excava- tion, the result might be visualized as folding doors, placed flat on the ground with ten feet of earth piled on each door. The ten sliding plat- forms were then attached to ten powerful motor-trucks by concealed cables. The ten trucks were lined up evenly, each attached to one sliding platform by just enoughcable to be out of camera range. With motors running, the trucks waited for the word from the director. As the camera clicked, the trucks leaped forward, pulling the crack in the earth apart with an effect ex- actly like an earthquake fissure. At that moment a mountain-top in the background roared, and the wr “ oat Rt ence 3 - 2 ‘ SS _ ee eee ‘e sky was bombarded with rock, which fell on the scene in a genu- inely dangerous barrage. The voleanic eruption was pro- duced by dynamite. The peak of a high. hill on Universal City préperty was drilled in twenty places and packed with dynamite. To give the effect of lava, fifteen concealed sets of fire hose pumped scalding muddy water from the far side of the peak to roll in torrents down the side toward the camera. The dynamite was de- tonated by electricity. As the ex- plosion hurled tons of rock and sand high into the air, the fire hose belched the dirty steaming water from their concealment. To topple down the buildings nearest the earthquake crack a dozen yoke of oxen were hitched to the adobe structures, ten on each side. At a signal from the director, they were lashed into action, liter- ally tearing the building apart. This is one of the few instances where a movie director has been permitted to use artificial means to produce an effect. The earth came near swallowing up the heroine, but, of course, the brave, fearless hero saved her from a horrible death. The trick of the earthquake is exposed below * * fs ont ae ee * iQ.MOTOR-TRUCKS This is how the motor-trucks were attached to the pieces of earth on the roller to produce the movie earthquake. It took a lot of hard work and a great deal of money to Stage this scene - * #SHORED- UP~ sTUNNEL The ‘‘mystery phonograph’”’ that will play any record requested by the host. the device is shown by the dotted lines a to The secret of Ordering the Phonograph to Play What You Want MAGINE yourself standing in front l of your phonograph giving it in- structions to play certain selections and having it faithfully carry them out. Mr. Earl Hanson, a radio en- gineer of Washington, D. C., has made this possible. The phonograph that does the play- ing is located in the garage or another part of the house. It is provided with heavy current telephone transmitters that are attached to the tone arm. These transmitters are connected to a coil of wire placed under the carpet be- neath the “dummy” phonograph located in the room occupied by the guests. Another coil is arranged in the dummy phonograph. This second coil is connected to the necessary am- plifiers and receivers. When a record is played in the garage, the voice- carrying currents surge through the coil under the carpet beneath the phonograph. The coil in the phono- graph receives these voice currents inductively, and they project into the room. When the host instructs the phono- graph to play a certain record, his voice is carried out to the garage in the same way that the music is carried to the guest-room. The person in charge of the actual playing hears the request and puts the proper record in place. To prove there is no ‘“‘trick,’”’ the host tells his guests that they, too, may make a selection. By adjusting the current strength in the circuits employed, the voice can be amplified practically any strength.

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With this new machine one person can do it Popular Science Monthly Wrapping Six Hundred Loaves of Bread an Hour The first step is to place a loaf of bread upside down on a sheet of specially pre- pared waxed paper. As you will see later on, there is a reason for the six stripes that run lengthwise of it When the folding has reached this stage, the loaf of bread is taken to the finishing machine. It pass- es between two electrically heated plates, which complete the folding and melt the waxed ends The cooling-trough is located behind the heating- plates. The loaves fit snugly against the sides of the trough; thus, as the wax congeals, it holds all the surfaces together The ends of the paper are then folded over. And the stripes? They are porous and will supply the bread with sufficient air to pre- vent it from becoming moldy, and yet not enough to dry it out After the folding, the bread is turned right side up. More about the stripes: Their number is varied accord- ing to the weather. In cold, dry weather two ventilat- ing stripes; in summer sometimes twelve ig te cooling-trough to harden the v7 GUT E ARM» HAND CRANK~ The loaf is now ready to be passed into the PLAT wax. Whether it be a six-inch loaf or even a twelve-inch loaf, this machine can be adjusted to handle it , COOLING-TROUGH ( MOVING ORM Here you see the entire machine—one loaf going in and one loaf dropping out. The turn of the crank on the floor of the cooling-trough is movable; one wheel near the heating-plates sends the end loaf on its journey to the ultimate consumer a aa ae Redo

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June, 1921 conte se enema When not in action on the lake in Prospect Park, Brooklyn, the yachts are placed in dry-dock inside the boathouse; each dry- dock consists of a cradle on wheels. There are about seventy-five yachts in the club at present He’s getting his yacht into the best possible position for crossing the line when the race starts. When the signal is given, the yachts are released and an official time- keeper on shore records the actual crossing time of each yacht Men Who Race Model Yachts Just as exciting to these grown-up boys as an “America” cup race are their city park lake contests Before a yacht is entered in a race it is carefully measured by the official measurer of the club. It is placed in a tank filled with water in order to determine the water-line. Length over all, sail area, and other racing details are also carefully recorded How is the actual sailing accomplished? The rudder is connected with the mainsail by a cord that is left loose when sailing against the wind. The tiller swings be- tween two adjustable nuts. But when sailing before the wind the cord is kept taut with the rudder on the same side as the mainsail As the yachts sail through the water, the owners follow thein in rowboats, guiding them when necessary. Care must be taken to prevent collisions and possible damage. The yachts are care- fully made and are expensive

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Popular Science Monthli; Was This the First Man? Reconstructed from bones forty thousand years old, found in the Neander valley, this picture is scientifically correct ET me take you back forty thou- sand years to a place in Germany called the Neander valley (Ne- anderthal). And there let me show you the fierce, half-brutish savage that roamed the wilderness—the creature that, as far as science now knows, was one of Nature’s very earliest attempts at creating the species Homo. As he slinks out of his cave or rock shelter to kill for his woman and his newborn babe, mark how-short and squat he is. He is not the towering giant that the popular imagination conjures up when it thinks of primi- tive man. By ac- tual measurement he By Charles R. Knight covered with long, coarse hair. And his legs—how short they are below the knee! His feet, massive as they are, rest not flat and solid on the ground, but somewhat on the outer edges. What thoughts teem behind that slanted brow? Science cannot answer. It can only measure his bones and re- construct his physical appearance. Who knows but behind those piercing eyes there is a yearning toward higher things? As he stands before us in all his primeval shagginess, grasping his whole continents; she shrugs her shoulders, and we call it a volcanic up- heaval. Forthwith everything that swims, crawls, and flies must adapt itself to the new conditions. Sh throws dinosaurs on the scrapheap be- cause they flounder helplessly under new conditions. She wants change, change, and change again. She experiments with this animal form and that, only to discard it for something that suits her new purpose. And so she molded the primeval living matter, the protoplasm of which all organic things are made, to produce the wonderful mechan- ism that we call man. stands but five feet two inches in height. Many a modern girl ." is taller. Yet he looks aa as strong as he is. His legs are stocky; his shoulders broad. His head is large larger than one would expect of a man so short. It dwarfs him, . in a sense;. it makes him seem smaller than he really is: And his lowering face accentu- ates his squat ferocity. The Neanderthal Man No Weakling How low his fore- head! What great bony ridges beetle his deep-set eyes! Never was there such a long, flat skull on any man tion. Science Monthly. science. Nature’s Great Experiment It took Nature millions of years to evolve life on the earth, and millions more to create man. What was her first experiment in man-making ? We asked Mr. Charles R. Knight, of the American Museum of Natural History, New York city, to answer this question in an article for the Popular Mr. Knight is a distinguished artist, whose restorations of prehistoric animals and men have won for him international reputa- The drawing that he has made to accom- pany his article is based on actual measurements of the bones of one of the oldest men known to It is not a fantastic conception, but an actual interpretation, the first of its kind, to the artist’s knowledge, that has ever been prepared,— and embodies a study of the latest scientific data available on the subject.— Editor. The Neanderthal sav- age was but one of perhaps many man- making experiments. Some of her attempts at creating a man are still to be found on the earth. There are the Veddas of Ceylon and the Bushmen of Aus- tralia. The Neander- thal man was, to a casual observer, no more primitive than are they. Other Experiments in Man-Making Nature was not too well pleased with the Neanderthal man. Al- most simultaneously she developed the Cro-Magnons, whose remains are found that followed him. And his chin—where is it? A weakling, you argue, if the chin is any index to strength of char- acter. But.this man was no weakling. Look at his profile. That deep and heavy jaw and the gorillalike char- acter that accompanies it — there determination is stamped, the deter- mination to fight for life and all that life means. : How strangely the whole face is pro- jected in front of the eyes, and with it the heavy nose and the coarse, pro- truding lips. This man is no Apollo. But what he lacks in beauty he more than sup- plies in aggressiveness and resource- fulness. He may suggest an ape, but he is a man for all that, and a man who towers mentally far above the beasts that he hunts. There is a curious stoop to his hairy shoulders. The powerful arms are heavy wooden spear in the moonlight —and so I have shown him in my drawing on the opposite page—he thrills us. This is our ancestor; this is the creature from which we evolved; this thing is bone of our bone, flesh of our flesh. We are stirred by his passions, urged on by his nameless in- stincts. Forty thousand years sepa- rate usfrom him. But millions of years separate him from still Jower animals. He stands close to us—this cunning, fighting, hunting, ferocious Neander- thal man. What Is Time to Nature? Time—what is time to Nature the great experimenter! A century to her is but as a single tick of the clock to us. She raises and lowers the tem- perature of the earth; she inundates 40 sometimes associated with those of the Ne- anderthal man. These Cro-Magnons were beautiful to look upon. A Cro-Magnon stood six feet and two inches. He was an artist in every sense of the word. His spirited colored drawings, sketched on _ the walls of French and Spanish caves, prove it. Probably he clothed himself in skin garments sewed together with bone awls; for such implements have been found in his burial-grounds. He had brain as well as brawn, and may have driven the Neanderthal man be- fore him and annihilated him. But why did Nature develop two such entirely different types of man in practically the same environment? Science digs into the earth, finds charred embers of fires long since dead, studies the scratchings on caves, and measures bones. But the answer? That Nature keeps to herself. ee Sore ee sip cee Sinan: 9 BRM IBNN>

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June, 1921 And Was This the Being Practically the oldest bones of any human type are those found in the Neander valley in Germany. From these bones Mr. Charles R. Knight has reconstructed the Nean- derthal man in this first scientifically accurate picture. This early man lived in caves. He used flint spear-heads , from Whom We Sprang? and knives—probably his spears were more often made of tough wood. He is here sallying forth on a nocturnal hunting expe- dition, Every detail is scientifically correct, from the large head to the short legs and enormous feet

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Adjustable Locomotive Seats HORT men or tall can use this locomotive seat. It was made especially for engineers. It can be raised or lowered six inches to accommodate a man from five to six feet in height. The seat is supported on rack members that rest on brackets attached to a box carried on locomotives. Tools and other equipment are kept in the box. The engineer has merely to adjust the seat. The vibration of the locomotive will not dislodge it. Concrete Jails for Criminals HE country jail has long been a stand- ing joke. If the tales told about it are true, no desperado ever took it seriously. There must be some truth in these yarns, for the town of Mansfield, Missouri, has built itself a calaboose of reenforced concrete, strong enough to hold the boldest jail-breaker. It has accommodations for a number of law-breakers. “Breaking” this jail would not be easy. If a man had a full set of tools, including a hacksaw and several dozen blades for it, he might be able to get out in three days if he worked steadily. © Ewing Galloway Sheep Haul the Produce of the Farm N New South Wales a schoolboy grows enough vegetables to feed a family of six. He does it with the aid of his father’s sheep. He had taught them to pull a light hand- plow and to haul his homemade ‘‘push” car. Two wethers could easily draw the plow over the boy’s garden. Three sheep haul a load of two bags, or six bushels, of wheat. In addition to carrying produce from the garden in this way, the sheep also haul all the wood required for fuel. It is surprising how well the sheep have been broken in. They allow themselves to be yoked without any sign of fear or dislike, in fact behaved just like any draft animal.

Foreign Crops in the United States ANY of the grasses that now form im- portant crops in the United States were introduced by accident. This is true of ‘‘Kentucky” blue grass, white clover, and others. But the Department of Agriculture is always scouring foreign countries for new crops. Alfalfa was imported in 1854 from Central Asia; Japanese rices in 1899. Durum wheat, introduced from Russia in 1899, now produces a crop worth $50,000,000 annually. Egyptian cotton grew to be worth $20,000,000 in 1919. It must not be imagined that it is necessary merely to bring in new seeds. Scientists carefully consider the adapta- bility and acclimatization of foreign plants. Popular Science Month;

Plotting Accidents on a Map TRAFFIC <«*nert of Washington, D. C., has gone about the task of eliminating automobile accidents in a thoroughly scientific manner. First find where most of the accidents happen, and then apply the remedy. That is the way William Eno reasoned it out. To do this, he employs a map of the city, and records on it daily the accidents, employing small colored pins. The pins, of course, are thickest at the danger points. The death rate due to automobile acci- dents in Washington is twice as large as that of New York city. Over the Hill or Around It OS ANGELES must be a very con- venient city—especially for automo- bilists. Where a road leads over a steep hill, a second road is provided that goes around the hill. The road that leads over the hump is the shortest way. The road that leads around the hill is the easiest way. If a man comes along in a big powerful car, he generally chooses the steep road. When a driver ap- proaches the hill with a limping “‘flivver,” he decides—if he is wise—on the long route. Very often “the longest way round is the shortest way home.”

will s way & flated vuleal and di Cur give a If ani of it 1 other by the A ¢ have | Sin much the pl which Dru 7B" ie miring was § breth1 ard’s woode an op head » The drunk shown If h must wear 1 better pledge he was

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xt mn, k of Nn a find and ed it f the ents, as, of nts. acci- ze as t con- Omo0- steep goes is the ound somes arally oy ap- ver,” -oute. is the ia June, 1921 When Rubber Is Uncured RUBBER is a peculiar substance. It must be treated just right before it will stand up under service. This is the way an inner tube would look, when in- flated, it if did not receive the curing or vulcanizing process that makes it tough and durable. Curing must be carried on carefully to give a perfectly uniform rubber structure. If an uncured tube is inflated, certain parts of it will swell to an enormous size, while other parts will remain virtually unaffected by the air pressure. A cured inner tube, when inflated, will have a uniform diameter. Since the advent of the automobile, much research work has been going on in the production of this important product, which has added much comfort to riding. Drunkards in the Middle Ages I EVER was there a time when a drunken man received envious or ad- miring glances. In fact, many years ago he was severely punished by his _ horrified brethren. He was forced to wear a “‘drunk- ard’s cloak,’”’ which was in reality a large wooden pail with a hole in the bottom and an opening down the side. The man’s head went through the hole. The pail was turned upside down and the drunkard was locked in, in the manner shown below. If he walked with difficulty before, what must he have done after? As he had to wear this cloak until he promised to be a better man, in other words, to sign the pledge, it is not difficult to imagine that he was soon in a penitent frame of mind. is ' am ft! Imitating the Spider’s Web to Catch Flies SPIDER’S web has great attraction for the average fly; he needs no entic- ing personal invitation from the spider such as we learned in the second school reader. This being the case, an English- man decided to copy the spider; he built a fly-trap that looks like a large-sized web. He used his son’s discarded hoople as a base, and strung threads across it in the manner shown above. Then he smeared a sticky substance flavored with poison on the threads, and fastened a piece of meat at the center as bait. Before long the threads were covered with dead flies. Weeds and the Law EEDS are flagrant lawbreakers. In spite of the fact that twenty-five years ago most of the Northwestern states of the United States made it illegal to allow Russian thistle to grow, this weed has spread from the Atlantic to the Pacific. Weeds in general are far more serious enemies to food plants than is usually recognized. Even students of this branch of agriculture know very little about the actual effect of weeds on plant diseases or of weed roots on crop growth. An interesting phase of this subject relates to the scarcity of water in some sections of the country. All plants re- quire much water in the process of growth. It is said that a sunflower consumes as much water daily as does a hill of corn. There is no doubt, therefore, that weeds can do growing crops considerable damage in using up moisture. 43 Dress-Forms Made at Home HE United States Department of Agri- culture is teaching women to make their own dress-forms. The only materials needed are a gauze shirt, some gummed paper, cardboard, scissors, tape-measure, pins, a sponge, water, and a pencil. The foundation of the form is a gauze shirt two sizes smaller than the model usu- ally wears, in order to have the tightest possible fit. The model puts this on over her corsets and a well fitting petticoat. The edges of the shirt are reenforced with strips of gummed paper. These strips are then applied with care all over the shirt, always running vertically, until the foun- dation is completely covered. When dry, the form is cut down the center of the back and pasted together. Blow the Plaster on the Wall SE the stucco machine shown below and you cut down the cost of the inside finishing of a building. Plaster and stucco are contained in a cast-iron tank, which, together with the gasoline engine that drives the air-com- pressor, is mounted on wheels. The semi- liquid mass is fed through rubber tubes. At the end of each tube the liquid stucco enters a nozzle connected with the air- compressor by another tube. Compressed air at a pressure of 22 pounds sprays the stucco mass to a maxi- mum distance of 250 feet and a height of 150 feet. or ceiling. The stucco adheres firmly to wall

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Popular Science Monthi To Study the Weather OX-KITES used by weather men for measuring atmospheric conditions occasionally develop a tendency to fly sideways or to per- form other antics in the air that interfere with the accuracy of ob- servation. If there is one weak stick in the framework of the kite, the strain of the wind on the sails is sufficient to produce distortions, and this leads to bad flying. Such defects are not, however, generally Cleaning Tall Street Lamps N the larger cities, a truck with an adjustable platform is used to take care of the street lamps. The man in our picture does the work without a truck. He carries a single-pole ladder that has a hook at one end. He simply places the hook over the top of the lamp-post and climbs up. The pole has heavy steel rungs to support him. When he gets to the ton, he twists his legs around the ladder to hold apparent until the kite is in the air. It has been found that a kite fastened by a short line to the top of a flag- pole will fly steadily in ordinary winds, and can be studied at leisure. One Man Operates This Conveyor NCE thirty men used to do the work this conveyor is now doing. The en- gineer who designed this conveyor used to stand and watch a score of men toiling in the sun to lift boxes and barrels up the embankment. This was down on the old Mississippi, where the sun is really hot. The engineer convinced the officers of his company that he could get the material up the embank- ment at a fraction of the price they were paying. They gave him seven thousand dollars, and he set about building this electric con- veyor. It has a moving belt that pulls the boxes and barrels up the slope in a hurry. Good Positions, Good Pictures HEN the Omaha was launched at Tacoma, Washington, the moving- picture camera-men scratched their heads trying to think of a suitable place to “shoot” the picture from. They wanted to be high and in the center. Why not use the crane and a material- handling box? Within fifteen minutes’ time they were swung out over the crowd. When the Omaha started down the launch- ing-ways, two cameras were very busy. About Machine Dish-Washing EW human dish-washers would refuse to give up their jobs to machines. The electric dish-washer is an expensive piece of mechanism in home kitchens; but in restaurants and school kitchens it pays to employ machinery for cleaning dishes. Hand -washed = dishes contain forty * times as many bac- teria as machine- washed ones. himself, and renews or cleans the lamp. When he has finished his work, he climbs down, and carries his ladder to his next job. A Ton of Steel at Every Shot HIS is the way the United States gov- ernment would build ‘“‘Big Berthas.” Let us compare this big fellow with the guns carried on the old Constitution, which did its fighting in the days of our great- grandfathers. A broadside from the Con- stitution’s twenty-two 32-pounders had a total weight of 704 pounds. The shell from this big gun weighs 2700 pounds and measures 16 inches in diameter. The new gun is of the disappearing type, and is to be used in coast-defense work. The slanting cape of steel is to ward off bombs that might be dropped by enemy airplanes. oc NaS al id ce Bevate ss Hee te anes With N°’ overloc Now listen shuts ¢ same ti times. nified t fects ir they ca Hear fects i better. Liste ten tir better. Har RA soul In mar passab] to walk the pec travel poor? coolies. In tl coolies employ They c which Above that w glare o} The three twenty little er

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ps rith sed Ips. the ries ook the 0st ings rists 101d the he r to rt gov- las.” the hich reat- Con- ad a from and type, vork. d off nemy M Bg» car hin I tk) paceman June, 1921 With This Instrument You Can Hear Yourself Talk ONE of us knows how he talks. We are so used to our own voices that we overlook our vocal defects. Now, here is a device that enables you to listen critically to your own voice. It shuts out all outside sounds, and, at the same time, it magnifies the voice about ten times. If every spoken word were mag- nified thus, it would be easy to detect de- fects in speech, and once they are found they can, by practice, be corrected. Hear your own voice, discover the de- fects in enunciation, and you will talk better. Listen to your softest tones magnified ten times in your ear, and you will sing better. Hammocks Instead of Taxis RAVELING through the Orient—that sounds much simpler than it really is. In many places the roads are almost im- passable, and none but the coolies attempt to walk them. How, then, do tourists and the people of the upper class manage to travel on routes where the roads are so poor?) They are carried in various ways by coolies. In the picture below you see a crew of coolies prepared to take their wealthy employers on a trip across a mountain pass. They carry on their shoulders poles from which hang hammocks of woven grass. Above these hammocks are grass awnings that will protect the occupants from the glare of the sun. The coolies travel at the rate of about three miles an hour, and receive from twenty to thirty cents a day, which seems little enough for such hard work. Cutting Armor-Plate with a Flame OUR thousand tons of armor- plate shell-torn as the result of shooting tests, was to be sold as scrap iron. Therefore it had to be cut up. This was a difficult job even for the oxyacetylene flame. The plate was badly warped by the impact of the shells, and the holes made were ragged and mushroomed. Specialists in work of this kind made special machines to cut up the plate. Each machine carries the torch automatically across the plate along the line to be cut. An ordinary spring phonograph motor drives the carriage. The machines paid for themselves on this one contract. $1,000,000 to Save $25,000,000 T sounds like good finance, doesn’t it, one million dollars to save twenty-five millions? That was the estimated amount needed to prevent forest fires in 1921. Everybody who reads knows what the shortage of paper has meant in the past three years—business failures, higher prices for books and magazines, a shortage in the market even of standard authors in cases where publishers are holding off new edi- tions in the hope of a drop in prices. Yet the combined effort of pulp manufac- turers, lumber associations, chambers of commerce, and the American Forestry Association failed to make Congress ap- propriate more than the usual $125,000. Eye Magnet Becomes a First-Aid Tool AGNETS to remove particles of steel from the eye are not new. Still, the eye magnet invented by Dr. Charles W. Burrows, formerly Chief of the Magnetic Division of the United States Bureau of Standards, is worth describing and illus- trating, because it meets the need for an efficient instrument for first-aid needs. It consists of a powerful electromagnet, light enough to be held in one hand and small enough so that the knurled grip per- mits the operator to extract a steel particle with ease. The weight of the magnet falls upon the operator’s arm. At the end of the casing, and close to the magnet, is a small lamp-bulb that throws a soft light directly on the injured eye. Piankets Protect Alfalfa F. ' guysaietssh every farmer ranks well as an inventor, for he must always be in- venting substitutes and applying his in- ventive faculties to all kinds of problems met on the farm. Dew and rain used to destroy alfalfa before it had a chance to cure in the sun- light. Now the alfalfa is put to bed every night. A heavy blanket of canvas is placed over the piles on the field. This pro- tects them from rain, and in the morning the farmer removes the blankets, again exposing the alfalfa to the beneficial sunlight. This is a simple way of saving money by preserving the crops. It is no great job to protect the alfalfa from rain and damp. A few men can cover a number of acres in a few minutes’ time. The blankets can be removed very quickly in the morning.

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Popular Science Monthy One Banjo Makes an Orchestra HEN you look atthe instrument in the pic- ture above, you think at first that it is a banjo; but when you notice that the top of the instrument almost touches the ceiling, you realize how large it is. It is five feet tall. Nature’s Own Field- Artillery VEN Nature is on the war- path. A mushroom has been found that actually ex- plodes. Naturalists call this mush- room the lycoperdon; coun- try boys call it a “‘puffball.” The interior of this mush- What is it? An orchestra. Behind the drum and inside of the neck are several musical instruments. When these are wound up and set off, they play musical records with all the gusto of a man- made orchestra. Thé instrument even in- cludes chimes. The four strings on the outside of the in- strument are made of steel covered with copper thread. These may be tuned and played, if desired. Vegetables Turned Into Flowers ARVING vegetables into shapes re- sembling flowers is not a novelty, but the chef in the picture is an artist in vege- table-carving. Glance at the spray of rosebuds in the vase. From the tightly closed bud to the one that is unfolding its petals, they are perfect. But should you attempt to catch their odor, disappointment would be your portion, because those beautiful rosebuds are nothing more than Irish potatoes in masquerade. The creator of so much beauty is a re- turned Italian soldier. He is to be envied when one reflects that the commonest vegetable, seen through his eyes, becomes a beautiful flower. Black-and-White Screens Assure Invisibility HOULD you want to prevent outsiders from looking in, and yet wish to see what goes on outside, paint window-screens white outside and black inside. Black absorbs light, whereas white re- flects it. Thus, if you paint the outside of your screens white, the light will be re- flected and will appear to blur. Whereas black paint on the inside will absorb all the light and not interfere with that passing through the mesh. The picture above was taken through a screen that was painted half white and half black. ‘‘Heatless’’ Light for the Movies HE are light that furnishes illumina- tion for the artificial sunlight of the moving-picture also furnishes an enormous amount of heat. A metal shutter protects the inflammable film when the pictures are not in motion. Now, however, the shutter can be dis- pensed with, for a “cold” light has been in- vented by M. Dussaud that consists of a wheel or disk upon the edge of which are sixteen incandescent lamps. As the wheel revolves, each lamp is subjected to the closed circuit and ‘is lighted brilliantly. The light is continuous, since one lamp is always aglow. The illumination of a single lamp is but momentary, and the high amperage cannot burn out the filament. 46 room contains a_ spongy, white mass. When the lycoperdon is young, it is very good to eat, like all other well-behaved mushrooms. But when it grows old, a white powder forms from the spongy mass that expands and breaks the outer cover- ing with a slight noise. The heat of the sun causes this expansion to take place. Our picture shows a mushroom in the act of ex- ploding. Going to Sea in a Kettle NDIA, which covers about one third the area of the United States, and which has more than three times as many inhab- itants, has retained some of the most primi- tive customs. In the rainy season the tributaries of the Ganges and other streams change greatly in level. Some rivers are easily crossed without bridges, by fording. But for travelers who do not wish to get their feet wet, the natives bring forth any handy utensil that will f serve as a boat. The large brass kettle shown in the picture serves very well as long as the guides keep it pointed in the right direction, and do not keep the traveler too long in such a cramped position. June, Seed Lik EED care fundam ing. Reali develop that co perience This hand-o1 and a rapidly Mean trols a seeds t disk wh falling 1 thrown and are manner One . E> Sl him. EH from an This train s: operate The doors o handle | is show: tion. mouthp he is r tions w! Air HE Eur airplane by the tives of compan Brussel. for tray The f Brussel: francs | betwee} don at dollars)

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i d- Jar- has eX- ish- un- TE hg ish- gy, the hich hab- -imi- the ther hout who tives will the the tion, ig in June, 1921 Seed-Sower Operated Like a Hand Organ EEDS must be planted with care. That is one of the fundamentals of successful farm- ing. Realizing this, a farmer developed a seeding-machine that could be used by an inex- perienced person. This sower operates like a hand-organ. Turn the crank, and a small disk revolves rapidly. Meanwhile the other hand con- trols a shutter that allows the seeds to fall upon the moving disk when it is open. The seeds, falling upon the moving disk, are thrown off by centrifugal force and are scattered in the proper manner. How This Little Pig Went to Market HIS little pig went to market, but he had the distinction of going in an entirely new way. First his feet were tied together; then a stick was placed across his back and another beneath his body. Strong banana leaves were wound around him and them. Next, a long handle was made by braiding more leaves; this handle was attached to the ends of the upper stick. The young boy whose job it was to take the pig to market swung the handle over his shoulder and let the pig hang. It may not be as com- fortable for the pig, but it is easier for the master than driv- ing him. : One Guard Operates a Train “AX TEXT stop, Times Square,” bawls the subway guard; but you don’t see him. His voice comes to you by telephone from another car. This is a feature of the one-guard-to-a- train system that is being operated in New York city. © Kadel & Herbert Painting Pictures from an Automobile HEN an artist tries to paint a street scene, a crowd of people invariably gathers around. How can he avoid this annoyance? Harry Lachman, an American artist, remains in his automobile when he wishes to paint. He opens a trapdoor in the top of his sedan. By placing his canvas and paints on top of the car, and by standing on the rear seat, he avoids the crowd. He places a screen around the top of the car and pulls down the shades inside so that he is invisible. A Line-Up of Telephone Nickels F all the nickels that are dropped into the telephone pay-station slots during a year were placed edge to edge, they would form a line from New York to San Fran- cisco and then extend far out into the Pacifie ocean. There are four hundred million of them! © Kadel & Herbert Rubber Bathing-Suits Now AT first glance this bathing-girl looks like any other bathing-girl; but when you look closely at her bathing-suit and cape, you notice that they are made of rubber (price, seventy-five dollars!). What are the merits of a - The guard controls all doors of a six-car train by a handle in one of the cars. He is shown preparing for a sta- tion. With a_ telephone mouthpiece and the handle, he is ready to start opera- tions when the train stops. Air-Travel Rates THE rapidity with which Europeans are taking to airplane travel may be gaged by the fact that representa- tives of the principal airplane companies recently met at Brussels to determine rates for travel through the air. The fare between Paris and Brussels was fixed at 150 frances (ten dollars) and that between Brussels and Lon- don at 175 francs (twelve dollars). rubber bathing-suit? In the first place, it is different, and that is always an attraction. Then, it will not fade if worn in the sun. And should the wearer actually go in the water, she will find afterward that her rubber suit dries quickly. Fish in Dry-Dock SCHOOL of fish were swimming near a dry- dock at Balboa; it so hap- pened that a ship was ex- pected at about that time and the gates were opened. What then? The school swam in. Later, when the water was pumped out, they were stranded on the bottom. The workmen carried home as many as they could eat, and government men dis- posed of 650 pounds.

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New York’s Wonderful Fire Doctor How Dr. Harry M. Archer risks his life in treating wounded fire-fighters By Raymonde G. Doyle raphy of Dr. Harry M. Archer, of New York, one of the first facts he would record would be that the doctor is chief surgeon of the Fire Department there. He might go further and say that Dr. Archer is regarded as a hero in the department, and that he holds a medal inscribed, ‘‘For Valor.’’ He has earned it, together with high public regard, for the reason that he has worked for more than a quarter of a century to build up the emergency medical service that he directs. The automobile in which Dr. Archer races to big fires probably stands alone in its class. It isn’t really an ambu- lance. It looks more like a pleasure car as it goes by. As a matter of fact, it is virtually a complete hospital on wheels, provided, among other things, with a power plant that can send it sixty miles an hour. He drives it him- self, and the car is always ready for in- stant service at a firehouse near his home. The automobile is divided into com- partments that are dust- and moisture- proof. They are fully stocked at all times with splints, surgical needles, and the sutures needed in the treatment of bad cuts. Cotton gauze, antiseptics, forceps, lancets—they are all there. fe any one were to set down the biog- There Is Even an Oxygen Machine And fastened securely so that a jolt cannot loosen it, is an oxygen machine. When oxygen was gaining prom- inence as a restorative agent in the treatment of partial suffocation, Dr. Archer found it successful. But he saw himself in a situation where the purest, freshest oxygen would be needed, and he realized that it might not be possible to get a tc ikful instantly. Forthwith the doctor provided himself with an oxygen generator and the chemical necessary to the manufacture of the gas. He hada special compartment fitted into the automobile, and in it stored his generator and the chemical— sulphite of soda. Water poured on the sulphite of soda generates the oxygen. The war produced a compara- tively new treatment for burns— the paraffin treatment. The men of the New York Fire Department _were among the first in this coun- try to benefit by it. The Archer automobile is equipped with the apparatus used Dr. Harry M. Archer, whose work for the department is merely a side job. He carries the rank of battalion chief in spraying the melted paraffin. There is a specially constructed at- omizer in which the hot liquid is vaporized, a ladle in which it is heated to 180°, and a supply of ‘‘canned heat”’ to complete the apparatus. Occasion- ally the canned heat has given out, and then fire-boxes of the depart- ment engines served instead. Some day, Dr. Archer hopes, the engine of the automobile will be provided with an arrangement for melting the par- affin. But the list of articles in this trick automobile is not yet exhausted. The «, The paraffin treatment for burns, one of the things discovered by war sur- geons, was early adopted by New York’s fire doctor 48 Popular Science Monthly One of the most necessary pieces of ap- paratus is an oxygen-tank. A com- partment in the car carries it sight of a badly injured fireman or an unconscious smoke or gas victim is all that is necessary to send the depart- ment’s chief surgeon on the run to the car. In an instant he could produce army cots and blankets. And should the necessity for artificial respira- tion arise, out would come a pul- motor. Behind Dr. Archer’s thirty-five years of service to the men of the de- partment and their families, there stands a list of some thirty thousand emergency cases that he has attended. In that time he has not missed a single big fire. The Fire Doctor a Hero But it is on the records that Dr. Archer has risked his life often and cheerfully to make fire-fighting easier for his men. And it is a matter of record, too, that one of these occasions arose when he calmly climbed down from his racing ambulance during the big fire in the Equitable Building, took a hypodermic syringe and a phial of drug from a compartment, and started for the entrance of the structure. And he went inside, dodging burning embers and falling bits of stone— went to a point where an official of the Equitable Company had been trapped behind a heavy iron grating while trying to save valu- able papers. Firemen were sawing the bars of the grating to release the man behind them. He was suffering, and he couldn’t be taken to the automobile for treatment. Dr. Archer pushed his _ hand through the bars and administered morphine to him, and then went back to the automobile and pre- pared a cot for the time when he should be released and carried to safety. The medal was presented for that deed. Dr. Archer’s work for the fire- men js a side job, so to speak. As a regular thing he directs the work of the physicians and nurses 0! a life insurance company. In the Fire Department he is a volunteer with the rank of battalion chief and he pays his own expenses. and v ture, | W.H to ing ing ni camer of in new n bone pose ¢ ing pi mals ; that wholl recen notice trasti daube moto! dence these mals ceal t Pre wate! this | tions reefs the t: laune wate! spenc no dé Th “NY T: to his ous other signs. on | Mou lights insta Hous oper: mech rine appli purp that lights gove] is ar sion biliti whiel mane Pu solve press light. foun brilli

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Dr. and sier r of ions own the ling, da ent, the ning ne— ficial had iron ralu- wing lease was aken 1ent. hand ered went pre- n he 2d to 1 for fire- \s work of a » the nteer chief June, 1921 Take Your Camera and Go Fishing You will discover a new world of fantastic creatures s UNTING with a camera” is a fascinating sport, well known and widely practised by lovers of na- ture, but it has remained for Professor W. H. Longley, of Goucher College, to inaugurate a new method of catch- ing nature unawares—‘‘fishing with a camera.” The aim of this new form of investigation was to bring to light new material on the familiar biological bone of contention—what is the pur- pose of the brilliant colors and strik- ing patterns displayed by certain ani- mals and fishes? It has been believed that this type of coloration is due wholly to sexual selection. Not until recently, when the war brought to our notice the obliterative effect of con- trasting and sometimes brilliant colors daubed on guns, ships, and motor-trucks, was much cre- dence given to the theory that these striking patterns on ani- mals and fishes may really con- } ceal them. Professor Longley’s under- water studies tend to support this hypothesis. His investiga- tions were carried on on the rich reefs in the warm waters of the tropics. Equipped with a launch, a diving-hood, and a water-tight camera, it was possible to spend hours in these warm waters with no danger and little discomfort. The camera was protected by a water- tight holder provided with a round window in the end opposite the lens, the necessary operations attending a snapshot or a time exposure being ac- complished by means of various con- trivances attached to the container. Adjusting the hood and stepping over the edge of the boat into the water, the ‘“‘camera-fisher’”’ finds him- self in a new world—a still, shadowy world of mystery, where swift forms shoot by and others loll idly about, none paying the least attention to the strange new thing in their midst. The dense foliage of the water world rolls gently with the swell overhead, yet nosound is heard from above or below. An interesting phase of the colora- With launch, diving-hood, and water- tight camera, the professor spent hours in tropical waters, studying marine life The Lighthouse Comes Inland to TS unattended type of flashing marine light is now being applied to highway purposes, marking danger- ous curves, railroad crossings, and other places heretofore marked by signs. An installation has been made on the road from Washington to Mount Vernon, and the lights are also to be or any gas. The flash occurs every second. It is really an explosion, lasting one twelfth of a second, so that an hour’s flashing is equivalent to steady burning of only five minutes. The flash is obtained from a tiny pilot light that burns constantly, but the It would appear that coloration i: fishes is for concealment from enemies or prey tion of fishes is the fact that in many species it is changeable, the scheme adapting itself, as far as possible, to its surroundings. By means of a sea- urchin or other bait, fishes were drawn from one group of surroundings to an- other, and the color changes to accord with the background were thus produced at the will of the observer. All the evi- dence we now have points to the fact that coloration in fishes, somber or brilliant, has for its aim the concealing of the wearer from enemies or possible prey. The patterns, too, are often changeable, in many species from longitudinal stripes to bands around the body. Where this is the case, the lengthwise stripes appear when the fish is in motion, and the transverse bands when it is at rest. Direct Traffic consumption of gas in twenty-four hours is only 0.6 of a cubic foot. The acetylene gas is stored in a steel cylinder containing a year’s supply, at a cost of Jess than five dollars, includ- ing putting in a fresh cylinder once a year. Acetone has capacity to absorb many times its own vol- installed in the White House grounds. They operate with the same mechanism as the ma- rine light, and their application to highway purposes by a company that supplies marine lights to nearly every government in the world is an interesting exten- sion of the sales possi- bilities of equipment for which government de- mand alone is limited. Purified acetylene dis- ume of acetylene, so that a large volume of gas can be stored in a small cyl- inder. In an ordinary cylinder, however, _ it would be explosive, so a receptacle has been worked out by Dr. Dalen, who _ perfected automatic marine lights. One marked advan- tage of the highway lighthouse is standard- ization in color, wording, location, and symbols to indicate the direction of curves, distance of rail- solved in acetone under pressure furnishes the light. This has been found best because more brilliant than electricity If a standardized system of colors and signs is adopted, It a California motorist in Ohio will instantly recognize po- tential trouble The flash occurs every second. is a flare, lasting one- twelfth of a second, an hour’s flashing being equivalent to five minutes’ steady burning road crossings, and so forth. Railroad usage is adopted, using red for danger, yellow for cau- tion, and green for clear.

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California has the largest electric chicken hatchery in the world; it hatches 100,000 eggs at a time, and has a monthly output of 120,000 chicks Chicken Farming by Electricity HE largest electric chicken hatch- ery in the world is located near Artesia, California. It has a hatching capacity of about 100,000 eggs and a monthly output of approximately 120,000 chicks. Chicken hatchery ex- perts claim that this electric chicken farm has gone old mother hen one better in that the hatching is done automatically and positively, whereas the old hen is sometimes negative in that she will desert her nest on occa- sion. While many other methods, among them the kerosene lamp, gas heater, solar heater, and steam, have been em- ployed to hatch eggs, the electric method has one important advantage over them all—it is automatic in operation and provides a uniform heat of constant temperature—a most nec- essary requisite for successful hatching. The electro-incubation method has several other advantages, including the elimination of the fire danger. Then, there are no lamps to clean, fill, and adjust, and no gas-burner to go out and asphyxiate the chicks with the escaping gas. Again, because of the automatic control of the tempera- ture, there is less chance of loss of chicks due to chilling or overheating the atmosphere. The automatic heat regulation is made possible by the use of a ther- mostat of the tandem wafertype. The wafer is made up of two brass disks. These are soldered together, and the air space between is filled with ether. The disks are placed horizontally, with a vertical control rod attached to the top wafer. This rod operates a horizontal control lever, the other end of which is weighted to give a steady and positive action. This lever actu- ates a rocker arm connected to the midpoint of the lever by a coil-spring. The rocker arm makes the contact to open or close the circuit. The entire control operates through the expansion or contraction of the ether between the disks. This ether is so volatile that a slight variation in tempera- ture will cause the wafer to expand or contract, thus clos- ing or opening the circuit. The same control has been adapted to the electric brooder, to which in addition has been added an alarm-bell system to give immediate warning of any sudden temperature fluctuation. In each case the electric heating unit consists of a cylindrical porcelain core with grooves into which are wound the resistance wire, so that the coil is self-insulating with no danger of the coils coming into contact with any metal parts that might cause a short circuit and result in a fire. Thus the hen is left entirely free for her task of egg production. Even in this work she is further urged by electricity used in the form of lights inside the coops to get the hens on the job earlier in the day. \ NEW YORK « UPPER AND LOWER RODS “7 CIRCUIT OPEN A clever mechanism controls the tem- perature of the hatchery automatic- ally; the electric plan eliminates danger of overheating or chilling 50 Popular Science Monthly Sending Freight in Steel Boxes F the freight-car here pictured comes into wide use, valuable freight may be sent with every assurance that it will reach its destination in perfect condition. Incidentally this ‘“‘con- tainer car,’’ as it is called, will save the railroads money. It will eliminate re- handling, billings, and _ rechecking. Theft will be prevented and valuable shipments will receive every protec- tion from fire and wrecks. The car carries nine steel containers, each containing an individual shipment. The containers may be lifted off at various stations. Each container will accommodate a load of five thou- sand pounds. A crane is used to lift the big steel boxes off the plat- form of the car. The New York Central Railroad recently attached one of the new container cars to a New York-Chicago train. Photographs © Kadel & Herbert In this idea for railroad freight- handling, each car carries nine steel containers of uniform size, which avoid all damage to freight How the Unscrupulous Beat Slot-Machines ELEPHONE § coin-boxes take three different-sized coins —a nickel, a dime, and a quarter. Whena coin is dropped into the opening at the top of the box, it is automatically weighed and measured before a con- nection with Central is established; a Chinese yen, if it were the proper weight and thickness, would bring a ‘‘Number, please?”’ from Central. Since the war New York has been flooded with foreign coins, many of which are the same size and weight as our “‘jit.”” Hence, the telephone com- pany receives a daily collection of souvenirs. But the greatest source of annoyance are the “nickel testers.’ These are smooth brass checks, with the weight and size of a nickel. June Dr N drive blow of th dang dang Tl drivi poin pile. shoe does hard type thou mer thre men pile The thou juri Ir into twel Tha this mov out the: driv wat deci gree z twe The for mer tons by @ A whe exh: are the heal the the fact of t has mea am pan mus gen vou neec carr wid ocel sup} nee reac

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yn- he re- 1g. Dle PC- ch vad 1ed ew Da igo we ake ana the ally -On- yper ga een r of t as om- . of e of rs.” vith June, 1921 Driving Piles on a New Principle OTHING is perfect—not even pile-drivers. iL ing this, an inventor produced a better pile- driver—one that pulls the piles into the ground. The blows do not strike the pile itself. of the new device. danger of splitting. The new pile-driver delivers tremendous blows on driving bars that bear on the projecting edges of a pointed cast-iron shoe fastened on the lower end of the pile. The pile itself is subject only to tension, since the shoe pulls it into the ground and does not drive it. When very hard ground is met, the old type of pile-driver must deliver thousands of blows with a ham- mer that weighs from two to three tons. Under this treat- ment, even a heavy wooden pile often suffers severe injury. The new pile-driver can strike thousands of blows without in- juring the pile in the least. Imagine a large pile sinking into the earth at the rate of twenty-six feet in four minutes. That is the speed maintained by this pile-driver. This rate of movement was made with- out a water jet playing on theend of the pile. It was driven down ‘‘dry.”’ When water is used, resistance is decreased somewhat and greater speed is possible. The pile is placed be- tween large steel girders. These also carry a slideway for the big cast-steel ham- mer that weighs several tons. The hammer is lifted by a powerful steam-engine. Concrete piles may be sunk without danger of breaking or cracking, and wooden piles without Realiz- Therein lies the value ) The United Set between steel girders, the pile is practically pulled into the ground \ Seining to collect young fishes from a bayou as its waters recede into the great Mississippi river \ Dry-Land Fishermen \ \ HEN the Mississippi river rises with the season’s freshets, it covers wide areas of flatland \ and the fish swarm over this region with the flood water. Following their natural trend, they seek the deeper \ pools in the quiet backwaters, many of which seem to \ possess the proper qualification for breeding-grounds. Here the eggs are laid, but before the young fish come to maturity the waters may have begun to recede. The older fish are wise enough to get away into the river channel before they are ‘“‘marooned”’ in these shallow land-pools, which were the deeper spots dotting the flooded flatlands. States Bureau of Fisheries has undertaken the task of rescuing the stranded young and thus saving many hundreds of thou- sands of fish for food. After the flood waters had receded, leaving the stagnant pools full of young fishes, seining parties were sent out to collect them. young trout, bass, and other fish are corralled in the nets and transported to the rivers. Thousands of Do You Know How Hard You Can Work? S a man reaches his limit of physical performance, when he virtually becomes exhausted, his blood-vessels are no longer widened, but on the contrary contracted. His heart finds it hard to widen the vessels sufficiently to allow the blood to pass. With this fact in view, Dr. E. Weber, of the University of Berlin, has devised a method of measuring the amount of work a man can do. All physical work is accom- panied by combustion in the muscles. You burn up oxy- gen like a fire. The harder vou work the more oxygen you need. Hence your blood must carry more oxygen. The widening of your blood-vessels oceurs spontaneously, so as to supply more oxygen as you need it. When the limit is reached, the vessels begin to You burn oxygen like a fire. The harder you work the more you consume. Your blood-vessels dilate so that the blood can take up more of it. When the limit is reached, the blood-vessels con- tract, sothat the heart must work harder to keep them dilated. This is the danger-point. It is the purpose of this apparatus to determine when the danger-point is reached 51 contract so that the heart must work harder to widen the veins. Exhaustion follows. This is the danger-point. It is determined by introduc- ing the arm into an apparatus consisting mainly of a tightly fitting cylinder, which is filled with water and which records on a rotating drum the vari- able volume of the arm (de- pending on the variable amount of blood contained therein). Breathing is re- corded at the same time, also one foot performs a motion that can readily be checked. The process ascertains the admissible and the most con- venient number of working hours for any given operation. After short intervals, during which some other group of muscles is operated, the out- put can even be increased be- yond the danger-point.

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How the Airplane ‘T= pilots who flew the first air- planes, more than a decade ago, scarcely realized how brave they were. A modern flier, as he inspects machines of theirs that have been preserved, marvels at the flimsiness of construction and the utter lack of the instruments on which he de- pends for safety. The Wright Brothers and Glenn H. Curtiss, whose picture appears on the left in one of his first ma- chines, sat on the lower wing and watched the earth swim past be- tween their legs. There was no streamlined body, no _ protection against the fierce blast of air set up by the moving machine—nothing. Look now at the picture that ap- pears at the right of Glenn H. Cur- tiss, a picture of a modern airplane’s cockpit. No less than forty instru- ments and control devices stud the Popular Science Monthly Has Developed in Ten Years $ APPARATUS WHLCH. MUST BE HANDLED bv 8) OP WATCHED! BY THE UOT. © 3 & _ s | 32 TURN INDLATOR 33 OXYGEN CONTROLS 7 SHOWN ™ 36 ERA KEY | SD. BONE REC E A. 40 LADO LEE TION FINGE® Ne MR ADSUSTIENT £08 ALTIVG CLOCK ee Ee TACHOMETER AIR. PRESSUR, G N&N ~ > | es ‘ VOMEIER 40 nos ‘ VELEN ETER IAL? CA } Pr AMR CONTR 7f td Ay 4 inner walls. At first glance it would seem as if a man must be many- legged and many-armed to manipu- late all these devices. Some of them, to be sure, could be spared, such as the radio communication apparatus, the bomb releases, the machine-gun control, and the cam- era-operating mechanism; for all these are but military adjuncts, with most of which the civilian flier has nothing to do. But the rest—for the most part instruments that were not in existence when the pioneers flew—the rest are nowadays deemed indispensable. If we needed any evidence of the wonderful progress that has been made in flying, surely we will find it in the half hundred gages, meters, and controllers of various types that the exigencies of aerial navigation have called into being Shooting Ducks from an Airplane UCKS have been shot from air- planes. They have also been slaughtered by the simple process of running the plane through a flock, a proceeding that is effective but some- what rough on the propeller if the blade gets a fair whack at a fat duck with the tip of a blade. Pictures show- ing masses of ducks shot by aviators always arouse questioning. birds occasionally in the neighbor- hood of some of the Texas fields, where they could follow the poor fowl down and. retrieve him, but none of them ever made claim to any record-breaking bags. The modus operandi was to pick out a flock on the wing and then to overtake them from the rear and shoot them as © Keystone View Company the plane slowly passed. This would require no great skill, as the bird would appear to be moving not more than from ten to thirty miles an hour to the rear, or else standing still if the pilot throttled the engine down. Hunting ducks by airplane, how- ever, is not looked on favorably by the government. About two years ago the War Department With a plane gliding along at from seventy to one hun- dred miles an hour and a gunner pulling the trigger of a shotgun, the birds would be strung out over the ground below for five miles. If the machine landed every time a bird or two went down, that would entail finding a soft spot to land upon and finding a new flock on the reascent. It is no trick for most planes to outfly the poor duck, in spite of the wild yarns as to duck speed by those who estimate their issued an order forbidding army aviators to hunt from airplanes or to maneuver unnecessarily over the feed- ing- or resting-grounds of waterfowl. And now that aviators have attempted plowing through flocks of ducks, thereby killing hun- dreds with the propellers, it is likely that the War Department order will be extended by law to include all aviators. Surely this method of hunting is not sportsmanlike. One _ air- hunter, who proudly had his picture taken showing bag by the number of birds they missed. Aviators tell of shooting Shooting ducks from an airplane, or killing them by run- ning the plane through a flock, is likely to be stopped by the government 52 the day’s kill, was charged with violation of the migra- tory-bird act. Fah ea I UGE oo Sy aige sr olcn a eal [’ p for b the ¢ surro It Essel ulate augym tratic there econ¢ whiel busti thee most those asmu tain nents of col befor Te were comk plied mear perfo whol the | Fran cana stral Cabl the 7 of tv TI runs it is that over hows grou cabl Syste Ky that whee and chin ing were

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at od Pee Fa ARES TS SLA GREE LIES LS poms oe Peolias June, 1921 Fertilizing T has long been known that green plants derive the carbon required for building up their structures from the carbonic-acid gas mixed with the surrounding air. It occurred to Dr. ft. Riedel,- of Essen, that vegetation might be stim- ulated in a high degree by artificially augmenting the carbonic-acid concen- tration of the surrounding air. He therefore set to work seeking some economical carbonic-acid supply, which he eventually found in the com- bustion gases plentifully escaping from the chimney-stacks of all factories, but most abundantly from those of blast-furnaces. In- asmuch as these gases con- tain some noxious compo- nents, such as sulphur, they, of course, had to be cleansed beforehand. Tests on a large scale were recently made. The combustion gases were sup- plied to one hothouse by means of a double line of perforated pipe that ran the whole length of the house. the Air with Carbonic-Acid Gas By Alfred Gradenwitz Two other hothouses, of exactly the same construction, but lacking the supply of carbonic-acid gas, were used in the experiment for the sake of com- parison. That there could be no question of any noxious effect was noted a few days after starting the experiment. On the contrary, there was in the gas- treated hothouse a notably more thriv- ing vegetation than in the remaining hothouses, where similar plants were grown without any carbonic-acid sup- ply. The leaves of castor-oil plants in the carbonic-acid hothouse grew to To test the efficacy of carbonic-acid gas on plants growing in the open, crops were surrounded by perforated pipes containing the gas In the hothouse experiments plants grew more than twice as well in the carbonic-acid houses as without the gas LL alone, without even a driver, a small tractor travels up and down the banks of the St. Maurice canal in France, dragging behind it a heavy canal-boat. What makes it keep tothe straight and narrow path? Cables, a balancing arm, and would happen? The heavy boat that the tractor pulls would tend to swing the rear end toward the river, thus putting extra strain on the machine and plowing up the ground over which = af twice the width of those growing in the ordinary hothouses. Tomatoes planted in the carbonic-acid hothouses weighed two and three quarter times as much as those grown in the other houses. With cucumbers there was noted, apart from a far more plentiful crop, a deeper green color; in all cases, an improvement of the flavor. Other tests were made in the open air with an arrangement comprising rectangular sections bordered with perforated cement pipes, which sup- plied carbonic acid, the wind driv- ing the gas in a varying direction toward the plants. On the opposite side of the hot- house, for the sake of com- parison, there was provided a field of equa! dimensions and with the same quality of earth, though left with- out any carbonic-acid sup- ply. The spinach crop ob- tained with carbonic-acid fertilization was two and one half times, the potato crop two and three fourths times, the barley crop twice as much as corresponding crops grown without gas. The farmer applying the process in actual practice has nothing else to do but to turn the tap of the carbonic-acid supply whenever required. Experi- ments so far made show that carbonic- acid fertilization of the air is far more effective than the usual fertilization of The process, moreover, aug- ments the power of absorption with re- gard to the usual fertilizers. the soil. The Electric Mule Now Pulls French Barges the broad wheels travel. To eliminate this tendency, a second cable and a balancing arm are used. The arm is rigid, and is connected at the front of the machine while the end of it travels along the second cable. 230 the principle of the resultant of two forces. The tractor, as you see, runs on large flanged wheels; it is propelled by a motor that gets its power from an overhead trolley. There are, however, no tracks in the ground to guide it; hence the cable system. How does this . system work? First, there is a fixed cable YET PPT x se PTE = Tia edi oO Balas eb \ : 4 Eyed Ss f ' ae 4 it es ~ H WHEELS & 3 om it) eee = RR * BALANCING ARM GUIDE ing cable. But suppose it Guided by cables, this tractor hauls heavy barges through were the only one —what Maurice canal, France. It gets power from an overhead 53 ie “e =! aa Es ES 3 ES » that passes over vertical |% a 4 wheels located at the front ies > 7 wd Be DAA CiNG Ant a. ' and at the back of the ma- ee AR ey: a chine. This is the main guid- a aS ee ae The towline is also at- tached at the front of the machine, but passes between two small rollers at the end of the balancing arm. Thus the pull exerted by the boat is absorbed by the arm and the second cable. It has been found that this small electric tractor is both faster and cheaper to operate than most towboats and tractors. Another advantage of the tractor is that it will travel anywhere around sharp curves, under bridges—and without stopping. sal the St. trolley

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What Makes a Champion? Not the form of an Apollo but the invisible relation of brain to muscle has a theory to account for any unusual ability in athletics. But very few of these theories are them. correct. Weare told, for example, that Babe Ruth’s success as a home-run athlete is so much faster than the hitter is due to his fine eyesight, or to rest of us is because it takes less But time for a sensation like tne sight N “ees # t every follower of sports to send a message to the muscles, his unusually powerful wrists. it isn’t true. By Eugene White Nixon and for the muscles to get into action after the message gets to And the reason the champion of a good ball, or the sound of the The difficulty is that the average starter’s pistol, to reach his brain, follower of athletics thinks that ath- and for his brain to send a letic skill depends upon some physical message to the arms and legs to peculiarity of the athlete that can be set them in appropriate motion. seen, or upon his peculiar way of going at his event. The truth of the matter is that athletic skill depends almost entirely upon invis- ible physiological and psy- chological peculiarities of the athlete that, of course, are not visible. Most of us feel that the athlete should look the part. And sometimes he does. Often he does not. Ath- letic ability depends more on what a man has inside of him than it does upon what he looks like from the out- side. That is the reason it is hard for you to understand why the Apollo you picked to win the half-mile race fell on the back stretch and rolled in agony, holding his suffering stomach with both hands, while a scrubby kid with bristling hair and a million freckles dashed out from the ruck and smashed the tape thirty yards ahead of the bunch. Brains Make an Athlete But all this is easy to understand if once we com- prehend that athletic abil- ity depends, not upon the size, shape, or proportions of the body, but upon quick reaction time, fine muscular coordination, an_ efficient circulatory system, and an athletic temperament. And we should remember that none of these requirements can be seen. The athlete has a quick reaction. shorter than ours. Reaction time is the time required for a sensation to travel to the central Johnson were burning them over the nervous system, together withthe time plate, unless you are a baseball player, required for the central nervous system you would probably be hitting at the forming The Secret Is—Brains How does Babe Ruth manage to pick out the good ones and bust them over the fence, while you and I can hardly see them going by? Why does Harry Vardon always get a perfect drive, while you slice every third one? How is it that Kolehmainen can run twenty-five miles with less distress than you run twenty-five yards? What is the secret of athletic ability? Is it a matter of size, build, or muscles? Is it a question of heredity or of practice? This article answers these questions for you.—Editor. Recording the heart action, the blood-pressure, and the nervous condition as denoted by the trembling of the hand 54 Popular Science Monthly Time on the board, the force exerted in jump- ing, and the divers’ nervous condition, are recorded by this device ball after it was safely in the catcher’s mit. Or if you were down on the starting- mark with Charlie Paddock in the hundred-yard race, he would probably leave you ten feet in the rear at the sound of the starter’s pistol. And your trouble in both cases would be due to your reaction time. You must have a short reaction time if you are to be a champion athlete. Why Reaction Times Vary Reaction time varies in length from a tenth of a second in the athlete to a full second in an extremely slow person. Small people are quicker than larger peo- ple, because sensations and impulses have shorter nerve trunks to pass over so that the reaction time is less. Reaction time may be shortened by practice. You may be a slow runner and yet gain some speed by practice. But if your re- action time is naturally long, you will never win the hundred-meter race at the Olympic Games or become a world’s champion fighter. Muscular coordination is the second important requi- site in athletics. Possibly coordination should be placed even before quick reaction, because there are a few athletic sports that do In other words, his reaction time is not require speed; but there is prob- ably none that does not require good If you were at the bat, and Walter form for the highest success. Good form in an athletic event means the most efficient way of per- in this event. We have June, learne results golf-b. that 1 volvec their « at ex¢ after must i each C Perfec Thi musele is coc Vardo birdies hole g reason ball on we lae Coo for al “form makes but ¢ him g tion, forearl good ¢€ great tion m player and ev And fact te nectiol tion j upon t Musel they al form come t nervou since a one tl there i muscle if the are ser Thu trainin skill j event trainin system of trail lar sys accust« That you @; man’s | looking cannot machir Whe tempt cated ¢ the pia the har a basek on aha Wrist conscio

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June, 1921 learned that, in order to get the best results in sprinting or in driving a colf-ball, we must have “‘form.’”’ And that means that all the muscles in- volved in the exercise must perform their duties in exactly the right way, at exactly the right time, and that, after performing their duties, they must instantly relax so as not to get in each other’s way. Perfect Coordination Means Success This perfect team-work among the muscles is called coordination. And it is coordination that enables Harry Vardon to make thirteen pars, four birdies, and an eagle in an eighteen- move we make with the dozens of muscles involved. But, as we prac- tise, the movements become more and more automatic until at last we simply will to do an act, and the thing is done without further thought. We have trained our nervous machinery to the point where it causes the proper muscles to contract at the proper time and with the proper force. And it will help us to understand the performances of our great athletes if we remember that their nervous mechanisms are of so fine a quality, and so highly trained, that their muscles are enabled to work in perfect harmony, so that they get perfect results. And it will help us in our own hole golf-match. And the reason you and I slice the ball out of bounds is that we lack coordination. Coordination accounts for all athletic skill or “form.”’ Quick reaction makes the athlete quick, but coordination makes him graceful. Coordina- tion, and not powerful forearms or exceptionally good eyesight, makes the great batter. Coordina- tion makes the great ball- player, boxer, wrestler, and even the fine dancer. And the most important fact to note in this con- nection is that coordina- tion is also dependent upon the nervous system. Muscles only perform as they are instructed to per- form by impulses that come to them through the nervous system. And since a muscle can do only one thing — contract — there is no danger of the muscles going wrong if the right messages are sent to them. Thus we see that training for form or skill in an_ athletic event is a matter of training the nervous system rather than of training the muscu- lar system, as we are accustomed to think. That is the reason you cannot judge a man’s athletic skill by looking at him—you cannot see his nervous machinery. When we first at- tempt any compli- cated act like playing the piano or throwing the hammer or hitting a baseball or clamping on a half Nelson and a wrist lock, we are conscious of every The athlete with electric lamps attached to his ankles, wrists, shoulders, and head. He is photo- graphed with a motion- picture camera in move- ment with the lights glow- ing. Paths described by the lights indicate the motions made and the time in which they are carried out. The current can be broken automatic- ally for one hundredth of a second, and the time in- volved in a movement can be determined by count- ing the dots, each repre- senting one hundredth of a second. This is the cyclegraph, invented by Frank B. Gilbreth, an Am- erican efficiency engineer As the runner steps on the first plate an electric contact is made, and as he steps on the second it is broken. The dial records the time required for one stride athletic endeavor if we remember that we must practise until we train our nervous sys- tems to do our will. Some forms of ath- letics require endur- ance, and this is the third quality of the athlete. And, like the other two, endurance does not depend upon any visible physical feature. You cannot tell by looking at a man how long he will last in a half-mile race or in a wrestling- match, because endur- ance depends mainly upon the heart. The heart is to the athlete what the en- gine is to the automo- bile. The reason Hannes Kolehmainen, the Olympic mara- thon champion, can run twenty-five miles without distress is be- cause he has a million- dollar heart. Whenever we make a movement of any 65 sort, it involves burning or combustion of fuel in the working muscles, just as we have combustion in the working engine of the automobile. Now, the heart furnishes the fuel for the muscles in the form of oxygen and bacon and eggs, and it also carries away the waste products of combustion. It performs both of these functions through the medium of the blood. And when we are out of breath or exhausted, the probabilities are that we are not ex- hausted at all, but that the heart has simply not been powerful enough, nor enduring enough, to keep up a sufli- cient flow of blood to meet our needs in an emergency. Thus we see that we cannot deter- mine by sight which ath- lete has the greatest en- durance. Your Apollo who should have won the half-mile race probably had a leaky vaive in his heart, or his heart was flabby from lack of proper training. And the reason he had to lie down on the back stretch was that he got choked up with carbon dioxide until it literally smothered him. And the scrubby-looking kid who broke the tape yards ahead of his nearest rival did so because he has a heart that drives the blood through his lungs and legs at terrific speed and under enormous pressure. We ought, by clean liv- ing and moderate exercise, to keep the heart ‘in such condition that it will serve us efficiently in all ordinary emergencies. Quick reaction, coordination, and endurance are the chief requisites in athletics; but, in addition to these factors, temperament also enters into the question to a large extent. The Athlete's Worst Enemy Is Nerves If Edward Ray were of the nervous type that is inclined to chew the bed- clothes or to drink carbolic acid under the stress of circumstances, he would never have carried the American Open Golf Championship to England. Orif Babe Ruth and Jim Thorpe were con- stantly in fear of finding a man under the bed, they would never have set any records for busting baseballs over the fence, nor at busting holes in the op- posing line. And if Benny Leonard were of the phlegmatic type, he might be drawing a pension of six or eight dollars a day at common labor instead of getting a thousand dollars a minute in the prize-ring. In the main, we see that athletic ability depends upon the nervous sys- tem, the heart, and the type of temper- ament, and not upon the size of the chest nor upon the shape of the calves.

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Adjust This Shaving Cabinet to Suit Yourself CABINET is mounted on a steel arm that may be clamped to table or wall. A swivel joint is provided so that the cabinet can be moved to the most convenient position. The mirror, which is also the door of the cabinet, may be placed at the best angle and held in this position. After the shave, the “implements” are placed in the cabinet and the mirror is swung back into position over the opening. Strange Tastes in Food Burton in og bi Brigadier-General the Daily Mail: “T have eaten lizard patties in the West Indies, porcupine in India, and curried liver of tiger. -Our soldiers in India used to like flying-foxes (bats). “Food accepted in one country may be rejected in another; and the tiger will reject portions of a carcass that are eaten with avidity (in the form of hag- gis) by a Scot.” Solid Copper from the Mine ATIVE copper crystallizes in irregular cubical forms, sometimes flattened, elongated, or round. It often is deposited around mine timbers or on iron objects, and is found in crevices between rocky masses. Perhaps that was the origin of the huge mass here shown. Solid masses weighing four hundred tons have been discovered. The mass hanging from the ceiling of this mine was so thick that, in order to dis- lodge it, the miners had to cut through it with an acetylene torch. He Built His Garage in His House N Cincinnati there lives a man who owns a flivver and is proud of it. Unable to find a place in which to tuck it away at night, he built a garage in front of and underneath his house. The house is a three-story wooden one, situated on a terrace, and set several feet back from the sidewalk. There is plenty of room for a two-car garage in front of the house when the steps leading up to the front door are built at the side. Does the garage spoil the appearance of the house? Look at the picture above and judge for yourself. However, when the door of the garage is finished and put into place, the garage itself will not be as conspicuous as it is now. The extra space will be rented to some car- owner in the vicinity and before long the garage will have paid for itself. Popular Science Monthly Locating the Buried Water- Pipes Electrically HERE is that buried pipe? Right here, ten feet down and twelve feet from the curb, says this instrument. A weak alternating current is sent through the pipe. The connections are made in the house or building that the pipe enters. This alternating current sets up a magnetic field. A small ex- ploring coil connected with a telephone receiver is then brought into use. A current will be induced in this coil when it is placed in the magnetic field, pro- duced by the current in the pipe. This current will produce a tone in the tele- phone receivers. The strength of the tone will depend upon the strength of the current, and this, in turn, upon the position of the ex- ploring coil in relation to the pipe. By listening to the tones in the telephone receiver, the exact location of the buried pipe may be found. Footless Football LAYING football on a_ table—the latest sport in England. There is one man on each team, and he sits at one end of the table while his opponent sits at the other. The players do not even put their feet on the table as you would expect. How, then, is table football played? With the hands. At each end of the table there is a keyboard that controls circular openings in the top of the table. By the rapid manipulation of the keys the ball is hurled backward and forward. AS ee ges $s & RS Re i> Mc is H If t over th Los An measur identit; checkin is of gi crime ¥ Why that co. a detec his rem crimina Eggs BA she the air acan o How bad? By Clairer machin lowered chain i sterilize The egy for a fe again.

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id id ‘X- sy ne ed he ne nd she eir »d? ble lar the | is e saa rsa he June, 1921 Morning Inspection in Jail IS face seems familiar,’’ says one of the masked detectives, as he looks over the morning line-up of prisoners in the Los Angeles jail. The prisoner’s Bertillon measurements are promptly taken, and his identity soon established. This method of checking up the whereabouts of criminals is of great value in curbing the so-called crime wave. Why do the detectives wear black masks that completely cover their faces? Because a detective’s usefulness depends chiefly on his remaining an unknown quantity to the criminals around town. Eggs Dipped in Boiling Oil to Keep Them Fresh A BAD egg—why isit? The pores of the shell allow air to enter, and in time the air ruins the egg—just as it will ruin a can of peaches. How can you prevent an egg from going bad? By hermetically sealing it. Victor Clairemont, of Chicago, has invented a machine for doing this. A tray of eggs is lowered by means of a motor-operated chain into a pot of boiling oil. The oil sterilizes the shells and seals up the pores. The eggs are allowed to remain in the oil for a few seconds and are then lifted out again. There’s a Right and Wrong in Strawberry Picking HERE is a right and a wrong way of doing everything. Below you see illus- trated the right and wrong way of picking strawberries. Study both pictures care- fully and the next time you spend your vacation in the country you will be able to pick strawberries as they should be picked. Strawberries should not be pulled off the stem. The grip necessary to pull them off the stem will partly crush them. The stem should be pinched just above the point where it is connected to the strawberry. In this way the strawberry is gathered un- injured. The ITH charts in use by the police in all large cities, it is possible to describe a person who has never been photographed. ‘*Spoken Picture’’ These charts, devised by Bertillon, are called the ‘portrait parlé,” or “spoken picture.” Bertillon classified all possible eye colors, hair colors, profijes, and full faces. His charts describe a human specimen as scien- tifically as an entomologist describes and classifies a bug. It is not enough to say that a man who is ‘“‘wanted”’ has blue eyes, blond hair, and a lean face. The exact shade of blue, the exact degree of blondness, the exact " shape of face, must be known. © Kadel & Herbert Seaweed Sweaters and Stockings EAWEED is the latest victim of econ- omists; new uses for it are being found constantly. The picture above shows it in its latest form—clothing. Both the sweater and the pair of stock- ings that the girl is holding were made from seaweed that grows in China. Yet they look not unlike woolen garments. Pine-needles are also being pressed into service; and so are many grasses and leaves. Ata recent exhibition of the Com- merce Bureau in the Customs House in New York city many grass-made garments were shown. New Crucible Eliminates Danger in Handling Hot Metal OURING hot metal from an ordinary crucible is a hazardous job. An ingenious and safer pouring device has at last been placed in the hands of the foundrymen. With this one man may handle a five-hundred-pound crucible with perfect safety. This is more than two men could handle by the old method. The crucible is counterweighted, and the great leverage makes it possible to turn it over with very little energy Seventy-five per cent more metal may be poured with the new crucible.

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Forest Guide-Posts Made Here \ HEN spring comes, the foresters connected with the United States Forest Service go forth into the woods and plant guide-posts along the highways and forest trails. Throughout the winter, when there is little work to be done in the forests, the men spend their time stenciling the names of towns and the number of miles between on seasoned boards. The boards are then given a preservative treatment to prevent them from deteriorating under severe weather conditions. In the picture above you see a Western forester at work on one of the boards that later on he will plant on some trail. Two Stories to This Cot LEEPING accommodation is one of the big problems of camping. Cots are heavy and they add greatly to the bulk of the ‘‘outfit.’”” A number of cots also require considerable space, and this makes a large tent necessary. An inventor has come to the aid of the camper with a cot that will accommodate four persons. It is really a double cot, one arranged on top the other. It requires only the space occupied by a single cot, that is, in ground space; the inventor has adopted the skyscraper idea of using air space instead. Just a few minutes of time and very little labor are necessary to take the four- man cot down and fold it up. Do Your Own Heel-Repairing ERE is a detachable heel. A base heel with studs is fixed on the shoe. Its counterpart—the actual tread—is slotted to receive the studs. Draw out a small metal slide and you unlock the studs. To put on the heel, you place it so that the studs will slide into the slots. Tap the bottom with the hand; then slide the metal strip, and the heel is locked into position. When the heel begins to wear down on one edge, take it off and exchange it with that of the other foot. If the day is wet, put on your rubber heels. If there is ice, put on spiked heels. This invention of Maurice Mayorowitz is a great convenience. Rescuing a Flat Tire with a Roller-Skate F you run on a flat tire, you will soon ruin it. This holds good for bicycles as well as for automobiles. If you are forced to use your bicycle when the front tire is flat, tie a roller-skate to it. The skate will follow the dictates of the rear wheel as effectively as the front wheel did. The tire will be protected from all contact with the ground. The small boy in the picture thought of this solution to his bicycle troubles after watching several disabled automobiles suffering from broken axles and other ills being towed along with trucks under the wheels. Popular Scvence Montlily Beans Four Feet Long EANS by the yard. That is the way they would sell them if they grew like this. Here is a bean-pod that contains enough beans to fill a hungry man. It is just four feet long. The average pod is four inches long. A simple calculation shows that this big pod is equivalent to just twelve ordinary pods. That figures out about six large pods to the meal for the average family. The overgrown pod is, of course, a freak and it “just happened” with no apparent reason. The soil it was raised on was very rich, but this does not furnish an excuse for such abnormal growth. Fence Wire for a Dress Guard STRIP cut from the “‘chicken wire’”’ of 4 a garden fence makes an excellent guard for a woman’s dress, when attached to a motorcycle. This was discovered by Mrs. H. Atherly-Jones, of Roehampton, England. The wire was first straightened out, then bent over the gasoline-tank, where it was padded with material that prevented it from scratching the enamel. It does not interfere with the cooling of the rear cylinder. It is held in place by straps ad- justed through the wires at the corners and twisted around the footrest supports. This dress guard can be detached in a few minutes and has the added attraction of being inexpensive. June, 1S —— Trans LEPE Afric phants a camp sit send runt quickest Some > motorcy¢ to “blaze domestic motorcyc hunters s breaks it As a mot more tha nothing « 1750-pou Turn ONVI iron The s upper lev electricit; an appa After the are adde carbon, si out as pig A Sh HOW) heard three qu: and the v It is so sn ing besids The sh maker in replica of hobnails |

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ily vay like Lins t is 1 is ion to ires the eak ‘ent ich, for ’ of ent hed by on, hen was | it not ‘ear ad- ind na ion June, 1921 Transporting a Motorcycle by Elephant in Africa LEPHANT-HUNTING in British East Africa is conducted with tame ele- phants as a means of conveyance between camp sites. But when it is necessary to send runners from one place to another, the quickest way is by motorcycle. Some trails are adapted to the use of motorcycles, but of course it is impossible to “blaze”’ a new trail with one. Then the domestic elephant is serviceable. The motorcycle is strapped on its side, and the hunters sit upon its head or back while it breaks its way through the underbrush. As a motorcycle does not weigh very much more than two hundred pounds, this is as nothing compared with the weight of the 1750-pound animal. Turning Steel into Pig Iron (CONVERTING scrap steel back to pig iron is a valuable idea from France. The scrap steel is charged from an upper level into an electric furnace. Then electricity is conducted to the furnace by an apparatus suspended from the wall. After the steel is melted, certain elements are added to increase the percentage of carbon, silicon, etc., and the mass is tapped out as pig iron. A Shoe the Size of a Penny HOWN below is the smallest shoe we ever heard of. Its length is one inch and three quarters, the height one and a half, and the width only five eighths of an inch. It is so small that the English penny stand- ing beside it assumes large proportions. The shoe was made by a sergeant shoe- maker in the English army. It is an exact replica of the military boot, even to the hobnails in the tiny sole. en at bl OR: f . enantio Pre aeo Ermine from Rabbits URPLE velvet and = ermine—that’s what kings and queens wear. And fora good reason—*“_ mine is too expensive for the rest of us. There is, however, a rabbit that has fur that looks like ermine. Nose, paws, ears, and tail are black, while the body fur is white. These rabbits are now being bred for their fur, and are valued at about eighty dollarseach. It is becoming fashion- able to leave the black tails off ermine wraps; thus the job of imitating ermine fur grows easier. Oxygen from a Tin Can ANY a miner’s life has been lost in a mine cave-in. When part of a shaft caves in, it frequently entraps a number of men, cutting off their air supply. To prevent the loss of life by this cause, the United States Bureau of Mines has developed an emergency breathing device that will supply entrapped miners with the vital life-giving oxygen for several hours, often long enough for the rescuing party to reach the prisoners. This little breathing device takes the carbon dioxide out of the breath exhaled, and returns the oxygen content fit for breathing again. Carbon dioxide is a deadly suffocating gas. 59 To Pull Out a Lion’s Tooth No Easy Job HEN a lion roars, he may have some thing to roar about. Take the case of Queenie, star lioness of the Brooklyn zoo. Even if she is more than seven years old and weighs somewhere in the neighbor- hood of nine hundred pounds, she couldn’t help roaring when she had a toothache. One of her molars was very badly decayed. The doctor looked it over, and decided that it must be pulled. But how? The details of how the thing was done are not lacking; Queenie was placed on her back and all four paws were securely tied by ropes to the sides of her cage. While her keeper held her jaws open with a thick stick, the doctor tugged at the tooth. Something New in Electric Stoves HE electric cooker illustrated here, which was invented by a German en- gineer, may be connected with any electric- light socket. The current passes through two, four, or more carbon plates that are immersed in the water contained in the tanklike base of the cooker. The plates are placed parallel at intervals of about one eighth inch, and the electric current passing through the water, which acts as resistance, soon raises the tempera- ture to the boiling-point. The heat may be regulated by raising or lowering the carbon plates in the water. Two circular openings are provided in the top of the tank in which the cooking-pots or cans are placed. The hot water cooks or heats the food contained in these recep- tacles. At four amperes this apparatus will heat food in one quarter of an hour with a current consumption of 0.2 5 kilowatt hours.

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Popular Science Monthly Shower-Bathing in the Street \ JHEN the thermometer _ registers ' nearly a hundred, the heat is almost insufferable in the narrow streets of the lower East Side of New York city. But in Jacob street there is one cool spot—-as the horse in the picture above found. It is at the place where two temporary water-pipes join above the street. The joint is not as tight as it should be, and as a result all who pass be- neath it receive a shower-bath. The cold water is very refreshing, and the barefooted boys in the neigh- borhood delight in playing under it. The New York firemen frequently take pity on the children and give themshower-baths with the fire-hose Give the Lawn a Clean Edge OW many hours does it usu- ally take to go along the edge of the lawn beside the concrete walk and nip off the straggling tufts of sod? The very thought almost makes one’s back ache. Run the remarkable trimmer shown in the picture along the edge of an eighty-foot lawn, and it will take just twenty minutes to make a clean job. The cutter looks like a queer kind of shovel. The trimmer digs a U-shaped trench be- tween the sod and the concrete, delivering the cutting on the walk, where it can be removed expeditiously. The result is a neat and attractive lawn, clear up to the very edge of the walk, that will be the envy of the street. Nothing but Wind to This Door NE of Boston’s residents, Mr. Henry Cummings, has invented a wind door that will keep out flies, snow, rain, cold, and hot air, and yet will admit people without blowing their clothes or otherwise inconveniencing them. The wind is created by an electric fan that is located directiy beneath a grille in front of the entrance. It sucks in the air, sends it through a tube to a place in the ceiling above the grille, and from thence hurls it out. Quicklime for Dynamite HOULD you wish to get rid of an old masonry wall without using dynamite, first drill in the wall a bottle-shaped hole having a small opening; tll this with lime, add enough water to slake it, and close the hole with a snugly fitting wooden plug. The resultant pressure will easily take down the wall. 60 Exit the Man-Propelled ’Riksha T is true that the old man-drawn ’rikshas still jog along the roads of Japan, but it will not be long be- fore the motor age invades that country. In fact, it has started. The first motor-propelled ’riksha has made its appearance on the streets of Tokio. Here it is. Sort of a freakish-looking thing, but it manages to get over the road all right. A one-cylinder gas motor is attached to the rear wheel. This gives sufficient traction to push the light ’riksha with its three occu- pants over the road. It will cover many miles for a few cents. His Cheese-Grater Mask OYS are not daunted by the high cost of baseball togs. They make their own gloves, masks, and chest- protectors. Take, for example, the enthusiastic catcher below. He took his mother’s cheese-grater, cut holes in it, and used it for a mask. From the neck up he looks like a jack-o’-lantern, but he doesn’t care. A piece of cardboard (stuffed, of course) serves him as a chest-protector, and strips of oileloth make his leg-guards. His glove is an old cap with a piece of leather sewed inside and some cotton bat- ting between the two. © Kadeli & Herbert June, 19 Tuber ‘Revea N eye beret approval Bureau United §S Agricultui It hap) an anime tests, but test. Th furnishes guard wh with the « Two ti placed be the left e3 then tak the third | frequent i four hou test is ir and swelli It Le ASTE} ordinar ness. It1 it. » With tl hands anc work. The lit workman’ any angle tion until > Theligt Pp anail. T greatly to

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© the left eye. © a nail. June, 1921 Tuberculosis in Cattle ‘Revealed by Eye Test AX eye test for detecting tu- berculosis in cattle has the approval of the scientists of the Bureau of Animal Industry, United States Department of Agriculture. It happens occasionally that an animal will pass the older tests, but will react to the eye test. The eye test, therefore, furnishes an additional safe- guard when used in connection with the older method. Two tuberculin tablets are placed beneath the lower lid of Cbservations are then taken at approximately the third hour following, and at frequent intervals up to twenty- four hours. Reaction to the test is indicated by discharge and swelling. Taking the Curl Out of Curly Hair HILE some women are going through the tortures of the permanent waver, cthers are clamoring for a permanent straightener. It’s simply a question of want- ing what you haven’t got. In England, now, hairdressers are using the steel rollers shown below on many women who have naturally curly hair that they want straightened. The rollers are held together by spring pressure; thus, when the hair is passed between them, it is ironed out considerably. There are small holes in the entire surface of each roller through which olive oil per- colates. The combination of the iron- ing, the oiling, and the previous washing of the hair in a softening mixture, will remove the objec- tionable wave. It Leaves Both Hands Free | anicononingi- nd a swivel clamp on the ‘ ordinary flash-lamp adds to its useful- ness. | it. It really makes a workman’s tool of ' With this lamp, a man may use both hands and yet play a beam of light on his work. , The little clip holds the light to the workman’s belt. It may be adjusted to any angle and it will remain in this posi- tion until it is changed. The light may also be placed on a wire or This is another feature that adds _ greatly to the convenience of the flash-lamp. Once a Battleship—Now a Crane ‘THE venerable United States battleship Kearsarge, will live on in active naval service as a mighty self-propelled floating crane. The crane mounted on this vessel can handle weights up to 250 tons, and even more. The Kearsarge will proceed under her own power from shipyard to shipyard to do the heavy work of juggling guns, turrets, armor-plates, and boilers. The crane has a revolving, hinged jib, electrically operated. It can rotate 360 degrees, and hoist a load from 40 feet below the crane base to 103 feet above it, while by luffing the jib, without rotating the crane, the load may be moved through a horizontal athwartship range extending from 72 feet to 101 feet from the crane’s rotation center. Gravity Aids the Foundry RON pipes used to be cast with the molds lying on their sides. It has been found more efficient to cast the pipe with the molds mounted vertically. © This brings about 2 better distribution of metal within the mold, and consequently sounder castings are produced that do not have any blow-holes in them. Casting the pipe-lengths in a vertical position also facilitates pouring the metal. The big heavy crucible containing the molten metal is handled with an electric- ally driven crane. Pipe-lengths as long as twelve feet are cast by this method.

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MAGNETIC LINES OF FORCE ~ — FREQUENT CURRENT . . Popular Science Monthy Airplanes Guided through IGHTHOUSES and automatic buoys are now used to guard the treacherous parts of our coastline and harbors. In place of a warning flash of light or the shriek of a siren, a single cable with an oscillatory electric current surging through it will soon be used. The cable will be placed at the bottom of the sea, and the current passing through it will set up a chang- ing magnetic field. Seaplanes and vessels passing over the cable will carry two small coils. These coils will ‘cut’? the magnetic lines of force generated by the current in the cable, and an audible note will be heard in the telephone receivers connected with the coils on board ship. The maximum strength of the note will be heard only when the vessel is directly over the cable. In this way a ship may be guided safely through fog. A small 500-cycle generator on the shore supplies the cable with current. Earl C. Hanson, who invented this system, is shown at the right with his apparatus Fog by Undersea Cable © Underwood & Underwood Damaulae Saanae A anm:n),. June, 1§ Nits tural E. Paul, wl intereste to disea deficient other in trail of the farn grave CO as well. These evidence clearly t limberne that no ous inroé the one I which p herds of hand. . souri sci from wh that of infantile seen whe have dis clear up infantile R. A Dean W periment the prob as a res investige IT ho could cli become | sling. The p ' suspendi » aring. . i remains | will slide but if the a vertics grip the two poin The el sists of a open, an lever ext the open of the le’ foot of | tached. through through the slot « and ring | Tope as | ; Tests on the climk the peda Its horizc © June.

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' deficiencies of one kind or an- » other in the diet, have struck a ' trail of possible importance to June, 1921 Do Greenbotile Flies Cause Infantile Paralysis? YUTRITION chemists at LN the Minnesota Agricul- tural Experiment Station, St. Paul, who these days are much interested in problems relating to diseases that grow out of the farmer, and, it may be, of grave concern to medical science as well. These chemists have found evidence that seems to point clearly to a connection between limberneck of poultry, a disease that now and then makes seri- ous inroads on poultry flocks, on the one hand, and hog paralysis, which persistently levies toll on the ' herds of swine-raisers, on the other hand. And E. W. Saunders, a Mis- ' gouri scientist, asserts that the source from which these diseases spring is also that of the dreaded poliomyelitis, or infantile paralysis. It remains to be seen whether what the Minnesota men » have discovered will in the end help to clear up the mysteries of the tragic ' infantile paralysis. R. Adams Dutcher and Stanley Dean Wilkins, at the Minnesota ex- periment station, became interested in _ the problem of limberneck in poultry investigation. > sata A SATE Sten Peet I Bas cand | lever extension pivoted in | theopenspace. To the end | of the lever a pedal for the » foot of the climber is at- | tached. through through the ring pivoted in ' the slot of the tube. » and ring will slide along the rope as long as no weight > Tests on the lever. | the climber rests his foot on fy ' its horizontal position, giv- as a result of specimens sent in for They went after the Climbing ITH the aid of an apparatus invented by a French house-painter, any person of average strength could climb a rope without great difficulty. Should he become tired on the way, he could rest by sitting in a sling. The principle of the invention can be illustrated by suspending a rope from the ceiling and passing it through aring. As long as the ring remains horizontal, the rope a hog that had died of paralysis. larve of these flies were fed to a cockerel. neck developed, and the cockerel died Rhode Island Red chick. The chick died the same day, after showing definite limberneck symptoms. The body of this bird was used for the develop- ment of still another crop of greenbottle larve, and these, when fed to a White Leghorn cockerel, brought about limber- neck symptoms, though the chick recovered. Larve from another chick that had died of limberneck were fed to guinea- pigs, and the pigs, after being Specimens of the greenbottle fly were infected from theory that the disease was caused by the eating of the larve of greenbottle flies. The carcass of a hog that had died of paralysis of the hind quarters was ob- tained. The head of this animal was placed in a screened cage containing specimens of the greenbottle fly, known to science as Lucilia caesar. Eight days later, 100 larve from the eggs of these flies, taken from the head of the hog, were fed to a White Leghorn cockerel. Limberneck symptoms developed, and the cockerel died. The body of this bird was in turn placed in a cage con- taining Lucilia caesar flies, and the larve from the carcass were fed to a a Rope as if It Were will slide freely through it, but if the ring is changed to a vertical position, it will grip the rope firmly at two points. The climbing device con- sists of a metallic tube split open, and has a ring with a The rope passes the tube and Tube When Eight days later Limber- stricken with paralysis of the hind quarters, died. Dr. Saunders, of Missouri, already mentioned, says that the greenbottle fly feeds on the carcass of a victim, and becomes po- tentially infected. After three days the eggs deposited are virulently poisonous. The creature that receives the larve from such eggs within a few hours, or certainly within a few days, becomes the subject of motor paralysis and death. Dr. Saunders even sug- gests the possibility already referred to—that the poisons which the green- bottle fly helps to create and distribute are the cause of infantile paralysis. But as to this the Minnesota men have made no investigations. The Minnesota men, however, have gone far enough to place the green- bottle fly under grave suspicion. a Ladder ing a sharp turn to the rope. The powerful grip of the ring on the cable enables the climber to rest his entire weight on the pedal on one foot and to move his other foot, equipped with a simi- lar device, to a higher posi- tion. For the hands, a sim- ilar tube with pivoted ring is provided that is merely used to steady the body of the climber. In descending, an up- ward pull on a wire at- tached to the pedal levers allows the rings to slip down the cable, but the descent may be stopped instantly by releasing the pull on the wire or by pressure on a pedal. i. the pedal, the ring changes tly « June, 1921 The pedals on this climbing device are so arranged that as long as the climber’s feet move, the pedals move; when the climber rests, the pedals grip the rope, supporting the climber 63

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Popular Science Moninly Tropical pond-lilies may be grown ina temperate climate if the water in which the lilies are planted is heated Warming the Water for Tropical Lilies N the Belvoir Park at Ziirich, Switzerland, there is a tropical-lily pond—shown above—heated by coils of hot pipes lying on the bottom of the pond. The pipes are connected with two boilers located in the gar- dener’s lodge. Throughout the sum- mer months when the lilies bloom, the water in the pond is kept at a temper- ature of from 80° to 85° F. And in the wintertime one of the boilers is used for heating the gardener’s lodge. In the rose-garden of Prospect Park, Brooklyn, New York, there is a some- what similar pond that has been heated in this manner for the past twenty-five years, Fight the Rat Menace with Poison A over the world the rat has made itself hated for its persistent spoliation of food and its carrying of disease. In recent years well organized campaigns have been carried on in various countries against this serious menace to the human race. Poisons most often used in this fight are arsenic, strychnine, phosphorus, and barium. Out of doors, strychnine is to be preferred where it can be safely used. In buildings barium carbonate is recommended, because, while rats are killed by as little as one and a half grains, it is comparatively harmless to domestic animals. Large numbers of rodents have been killed by phosphorus in Australia, while in Japan and the Philippines white arsenic has been used, and else- where lead arsenic. Although many rat poisons are made up of more than one poison, it is now recognized that a single poison is generally more effec- tive. Baseball at Home for Exercise UTDOOR exercise, of course, is the best in the world. Tennis, golf, football, baseball—what healthy young man (and nowadays young woman) would not wish to spend part of every fair day in. the pursuit of one or more of these games? But, alas, whe™ one lives in a city flat, and spends most of one’s time in» an office, there is secant oppor-- tunity for such exercise. If \ this is your con- dition, and if >. BOILER Y you would like ~. om ef. to obtain with- . “Ay in out leaving your Agi own room the aon > Avorn . — ste “5 (as a muscular devel- Setleest bas ie opment usually > 0." obtained by swinging a gor” «+ stder > “Bevan invention that will deliver+tte ¢ 27> ~~ 7 Charles H. Reynolds, of He mosa Beach, Californ has patented an apparatus onsisting of a suita) handle to which is fitted a s" ging steel frame. rubber band of sufficient strencth across ue en d the ‘‘bat’’ permits the frame to as the stick is operated backwar.u and torwara. A suitable weight at the end of the frame serves a the ‘‘ball,’’ which can be batted in one’s room without danger of its flying through the window-pane or inti the mirror. The apparatus also acts as a punching-bag. Five Thousand Pounds Hurled into the Ai RILLING for oil is a gamble. may turn out successful or it mage not. Dame Nature has more to si about this than the drillers. When tly drill gets down into the earth fi enough, something exciting usuall— happens. If a sudden rush of of mounts skyward, there is great joy # the camp. If there is merely a whit of gas, everybody is dejected. The picture shows one of these dit appointments. When the drill reached a depth & fourteen hundred feet, there was terrific rush of gas. The drill hag punctured a_ subterranean pock#y where gas was stcred under tremelf dous pressure. It w2s just like pricif ing a toy balloon with a pin. The ga rushed to the surface and carried mal of the well-drilling tools with it. Ti black streaks in the photograph repr sent drills, wrenches, sledge-hammeyy and crowbars. These shot skywarf} together with a mass of tangled ropt Just five thousand pounds of tools toy this trip on the top of the gas cushiof} If a man had been over the hole, ! would have followed the tools. The natural gas that spouts throu the ‘‘oil-well’’ is very volatile a therefore highly inflammable. (: PARC eae eee has to be taken that it is not ignite It may be months before gas _presst drops to allow drilling to continue. Instead of oil, this well spouted a stream of gas. It took the drillers’ tool-kit on a skyward trip 64 » Ju OK C gatic bigg vent saw duri chine gasp hibit he be cross the ¢ a hun acco! Th mean an or mach half alight miles terrifi ing h to sol plane Whict Atlan and \ feet, rectly A mer; alight Cay perier

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end \rves a vit hou or intd ble. I : r it ma to sa hen tht rth f usualif . of ie t joy: a whe hese di depth 1 a was trill ha pocke treme ke prici The g ied mal! it. Ti ph rep hamme sky wall rled rope tools tot 3 cushi0 > hole, } Is. s throug atile a le. yt ignite s pressl ntinue. » June, 1921 ey >, a ain eee Se. no end. s © Kadel & Herbert 1¢ ma To Cross the Atlantic Ocean Caproni, }@rld-famous as a designer and builder of huge flying- machines, has surpassed himself with this new BY; ine planes support a sixty-six-foot hull in which on Wings one hundred passengers take their seats. developing 3200 horsepower, will drive the craft across the ocean at a speed of at least sixty miles an hour Eight engines, a Builds a Transatlantic Flying-Ship Nine planes are to carry one hundred passengers in a cabin with wide windows signer and builder of airplanes, a man who dreams of aerial navi- gation on a grand scale, has built the biggest airplane that any one has yet ventured to construct. Those who saw the huge bombers that he built during the war, multiplaned ma- chines with spans of about 100 feet, gasped at his daring. But now he ex- hibits to us a flying-ship with which, he believes, the Atlantic ocean may be crossed in not more than a day, and in the completely enclosed hull of which a hundred passengers find comfortable accommodation. The building of so huge a craft means more than the magnification of an ordinary biplane or triplane. This machine weighs twenty-four and one half tons, we are told. If it were to alight on land At so low a speed as forty miles an hour, the impact would be terrific. Indeed, this problem of land- ing has been one of the most difficult to solve by the designer of big land air- planes. Curtiss, who built the America which was to have flown across the Atlantie just before the war broke out, and which had a span of about 130 feet, appreciated the difficulties cor- rectly. Accordingly, he made the America a seaplane. It is easier to alight on water than on land. Caproni, looking back at his own ex- periences with heavy land machines, eo the famous Italian de- has evidently decided that Curtiss’ policy is right; for his huge craft starts from the water and alights upon it. For all that, he encountered trouble. In one of the first short trial flights on Lake Maggiore in Italy, the hull was damaged as it struck the water, showing that even impact with a fluid that can easily be displaced is not without its dangers. To lift a weight of twenty-four and a half tons, a huge wing surface must be provided, in this case 7150 square feet. A single pair of superposed wings, such as we find in the ordinary biplane, could hardly carry so huge a load. The span would be enormous, so much so that it would be far more difficult to make the wings strong and stiff enough than to build a bridge. Hence, Caproni built three super- posed wings, thereby cutting down the span. But evidently two sets of tri- planes were not enough, according to his figures. He has supplied three sets, with a veritable forest of struts to tie them together and a maze of wires between. All this means wind re- sistance, and therefore low speed, despite eight engines developing a total of 32000 horsepower. No definite figures of performance have reached us from Italy, but it is doubtful whether more than sixty miles an hour can be made. Below the wings is the passenger 65 cabin, or hull. Its interior is more like a railway-car than a ship. It has wide windows and comfortable seats. Those who have studied the com- mercial possibilities of aerial naviga- tion will naturally compare Caproni’s nine-planed flying-ship with a rigid dirigible of the Zeppelin type. Ca- proni can probably build a transatlan- tic flying-ship at a smaller cost than the Zeppelin Company can turn out one of its 600-foot dirigibles. But it is a question whether, in the end, the dirigible will not prove commercially more practicable. The speed of a Zeppelin would certainly be as great as, if not greater than, that of the giant Caproni. It could earry fully as many passengers. It is not utterly de- pendent upon engine power for sup- port; for it can float in the air for hours while repairs are being made. On the other hand, the Zeppelin needs an expensive harbor or shed in which it can be housed, or, better still, a tall mooring-tower from the top of which it can swing in the wind. The experiences of the Germans with the Bodensee, the huge Zeppelin that was plying regularly last year be- tween Berlin and Switzerland, and which rarely flew with an empty passenger-seat, lead one to the con- clusion that, all things considered, the advantage lies all with the dirigible for long-distance commercial flying.

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Housekeeping Made Easy A tiny coal-stove that will fit over one of the holes of the regular stove has been invented. The lid is re- moved from the large stove to supply the draft Popular Science Monthl;, Saas Inside of one end of this shoe-brush there is a tube of shoe polish. When the cap is taken off and a key turned, the paste oozes out cn to the bristles Here is a machine that will wash, peel, and wash again, three hundred pounds of potatoes in an hour. Knives that revolve rapidly scrape off the skins The back of this brush has slits in it to let the water through; thus it can be washed easily every time it is used © Keystone View Company A coal fire is built in the small Pressing trousers by electricity is the latest compartment beneath the tank labor-saver. You clamp the trousers between of the clothes-washer. It sup- boards and turn on the ‘‘juice”’ plies the heat to the water within while the woman turns the crank Can you cut a pie evenly? If not, use a knife of many blades like the _ one shown above. It is fastened to the edge of the plate and will quarter Hot air in winter and cold air in summer are a pie at one stroke supplied by this electric fan and heater 66 Here is a dish-washing stand that is connected by tubes with the hot- and cold-water pipes. When it is opened, the cover is used as a tray for holding the dishes Bottles that contain poison should be different from other bottles. Here are some shown at a chemists’ exhibition; the one lying down can’t stand up June, 1 More ULIA] / famol ing some de i of i} a flatwor ing whi through} ly by alte late thes terms—V Huxley life of rat all this a Chen CIEN rapid publie, i search w Ifa trained ¢ constitue and cole would e3 within ty As a1 dozen ck the prob equipped up tons ¢ Di ATS poss eases. | has tend is a dang A wor virulent that hac contract carried i The ¢ and othe Test TLTR che) rays in t and tha etc., tof By ex source © months’ may be } Yeast CCO it a be used blocks. tones h

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June, Keeping Up with the March of Science Facts for the man who wants to know More About Living Forever bared HUXLEY, a descendant of the / famous Thomas Huxley, has been mak- ing some experiments that throw a great deal of light on age and growth. He kept a flatworm at the same age for a time dur- ing which the rest of the brood passed through nineteen generations, and this mere- ly by alternate starving and feeding. Trans- late these nineteen generations into human terms—we are back in Chaucer’s time. Huxley has succeeded in prolonging the life of rats by about 40 per cent. But, alas! all this applies only to flatworms and rats. Chemical Analysis Is Slow CIENTIFIC methods have made such rapid strides in recent years that the public, ignorant of the difficulties of re- search work, has come to expect too much. If a can of ox-tail soup were sent to a trained chemist for analysis of its chemical constituents, including spices, preservatives, and coloring matter, most business men would expect him to produce a full report within twenty-four hours. As a matter of fact, it would require a dozen chemists, working continuously upon the problem for a dozen years, in the best equipped laboratory,”~and they would use up tons of soup. Diphtheria from Cats Kee have been studied frequently as possible carriers of contagious dis- eases. Recent investigation along this line has tended to prove that the household cat is a dangerous carrier of disease germs. A worker in this field recently isolated virulent diphtheria bacilli from two cats that had been pets of a person who had contracted the disease. The germs are carried in the fur of the animals. The cat is not the only offender. Dogs and other household pets are also carriers. Testing Paint with Light JLTRA-VIOLET light has a marked chemical effect. It is the ultra-violet rays in the sunlight that produce sunburn, and that cause paint on houses, fences, etc, to fade and drop off. By exposing painted surfaces to a rich source of ultra-violet light, the effects of months’ exposure to the light of the sun may be had within comparatively few hours. Yeast for Half-Tone Blocks ACCORDING to the Paris daily press, it appears that compressed yeast is to be used for making up half-tone printing- blocks. In the usual practice, the half- tones have certain disadvantages in the matter of cost and difficulty of preparation, and are easily worn out. A process now comes from Germany in which it is proposed to use compressed yeast as a plastic material for making the half-tone blocks. But the fine point of the process consists of a newly discovered method of treating the compressed yeast with various chemical products among which formol is found to be the best. It is then wholly or partially dried and com- pressed at a moderate heat, thus produc- ing a compact mass that possesses a re- markable degree of hardness. The mass, which is at first in the plastic state, is com- pressed upon the negative plate and is employed instead of more expensive plastic material. About Vitamines T has been discovered that the vitamines contained in our food are essential to life. Without them scurvy and other dis- eases are brought about. Auguste Lumi¢re has been trying to find whether this also holds true in the case of plants. His ex- periments lead him to believe that this is not the case. It appears that microbes may be readily cultivated in mediums of strictly mineral composition. Lumiére boiled beer yeast, which is rich in vitamines, and found that the beer yeast had lost all of its vitamine power. However, fungi were found to grow rapidly in a broth made of the boiled beer yeast. Starvation a Long Process HE death of the Mayor of Cork after voluntary starvation of seventy-five days revived interest in the problem: how long can a human being live without taking food? Resistance of a human organism de- prived of food depends upon the reserve supply of fat which that particular organ- ism has stored up. In the last thirty years several men made the experiment of fasting for long periods. Succi abstained from food for thirty days, and in that time lost 19 per cent of his weight. Dr. Tanner, under strict surveillance, fasted forty days. A remarkable record was that of the artist Merlatti, who abstained from food for fifty days. After the first five days of fasting came a long period of severe depression and weakness, accompanied by loss of temperature that compelled him to remain in bed for ‘the rest of his fast. Persons in a state of lethargy produced by sickness or artificially brought about by hypnotism have been able to survive com- plete abstention from food for much longer periods. The most remarkable instance is that of Anna Garbero, who lived thirty-two months and_ eleven days without taking food or drink of any kind. 67 How an Egg Conquered Moss URING his sojourn in the south of Europe, a French naturalist had the rare opportunity of observing an intensely interesting struggle for existence between an egg and a moss plant. The egg was that of a lizard which had been deposited on a cushion of moss. It was enclosed by a white protective cover- ing of leatherlike toughness. The moss on which the tip of the egg rested, secreted at the point of contact a substance that gradually dissolved the leathery shell of the egg. When there was no longer any re- sistance, the stem of the moss plant pene- trated the shell and sent its branches through the substance of the egg, emerging at the opposite end. But the egg was equal to the emergency. It enveloped the stem of the moss inside the egg with a membranous coating that formed an insulating tube around the in- truder. Then the sent out side branches through the egg, traversing it, but these also were made inocuous by an albuminous coating. In spite of this struggle against the intruding moss, the lizard embryo developed to all appearances normally and finally emerged from its prison unharmed. moss Power from the Sun UR sun sheds five thousand horse- power on every acre of land in the tropical regions of the earth. Efforts were made to harness this great force as far back as 1615,; when de Caux attempted to make this power available for the use of man. : Large reflecting surfaces have always been used, and a solar plant was once built on this principle in Egypt. However, the efficiency of the plant was very low only sixty-three horsepower an acre. It is possible that in the future the power of the sun will be made available through the use of the photo-electric cell, which generates an electric current when light falls upon it. Writing Music a New Way EVEN white notes and five black notes on the piano make up the chromatic scale. Professor E. V. Huntington sug- gests that this be changed to six of each. Why? To assist in the simplification of music reading and writing. In connection with this, Mr. T. P. Hall suggests that the staff be changed; instead of five lines there should be six—allowing a line or space for each note of the chromatic scale. Thus sharp and flat signs will be entirely eliminated. The lines of the staff will correspond with the black notes on the piano, and the spaces will correspond with the white notes. A further suggestion is that the notes in the key of C be corrugated so that

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they will be recognized easily both by sight and by touch. This system will undoubtedly simplify the study of music in some respects, but it will cause complications for those who learned the old way. Where Did Life Originate? “TET the waters bring forth abundantly ~ the moving creature that hath life.’ So runs Genesis. Many scientists believe that life originated in the sea, since the sea and the air contain all of the substances present in the human body. oven today it is the ambition of nearly every creature of the sea to tackle the dry land. Professor Thomas, an English natural- ist, claims that the desire of the animal kingdom has been to get out of the water. To accomplish this, many of the creatures have overcome difficulties that would appal the heart of the bravest man. Did this strong desire, persisting throughout the ages, bring about the development of a creature that had legs in place of fins? If so, man had his beginning in the form of a little creature that braved the dangers of the dry land to satisfy a desire to leave the haunts of the deep. Wireless Photographs HOTOGRAPHS have been sent over telegraph wires and some cxperiments have also been made with the wireless transmission: of photographs. However, the wireless transmission of photographs has not been satisfactory and much work remains to be done. It is true that some remarkable results have been made with radio transmission, but nothing has been done that would stand the test of commercial application. The problem of interference has been a difficult one to overcome. The reception of stray waves during the sending of a photograph would cause an inaccuracy in the photograph. Diet of Starlings HE starling has spread over all the Eastern States and is becoming more numerous every year. To determine whether the bird is useful as a destroyer of noxious insects, the biologists of the Department of Agriculture examined the stomachs of more than 2000 adult starlings and about 300 nestlings. The adult birds feed virtually all day and eat incredible quantities of in- sect food. The young starlings, which remain in the nest from sixteen to twenty days after being hatched, are fed by their parents at inter- vals of three to six minutes throughout the day of twelve hours and obtain more than two thousand meals before they leave the nest. During the first four or five days their diet consists principally of caterpillars, the soft larvae of beetles, flies, ete., and of spiders. Later they feed on millipeds, grubs, grasshoppers, crickets, and beetles. In the stomach of one young starling the remains of twenty-six clover-leaf weevils were found. $1000 for a Horseshoe 1 you want to earn a thousand dollars? Invent a horseshoe that will prevent horses from slipping on icy or wet pave- ments. The American Humane Association of Albany will give this amount to the lucky person offering the best design before 6 P.M., July 1, 1921. Not only will the inventor of such a device do a great humane act, but he will also enrich himself to some extent. De- tails of the contest may be obtained from the headquarters of the American Humane Association at Albany, New York. Cold Makes Plants Grow HERE is a general belief that cold weather is responsible for the dormancy of plants and trees. This is not so. Mr. Coville, an experimental botanist, has studied the growth of blueberry plants under controlled temperature conditions, and has found that cold weather is not responsible for complete dormancy. Even after it is established, the mere exposure of the plants to warm weather is not sufficient to restore normal growth. He has also found that plants will not be ‘restored to a condition of normal growth unless they have been exposed to a period of chilling. Mr. Coville points out that the stimu- lating effect produced on dormant plants by cold is intimately associated with the transformation thereby of stored starch into sugar. Gassing the Burglar +5 Shea eecrars must soon add a gas-mask to their tool-kit. A device recently patented by R. C. Roeschel, of Harrisburg, Pennsylvania, will make the cracking of safes a hazardous job unless the burglars are thoroughly protected by gas-masks. A number of glass containers are so arranged that they will break when the safe is tampered with or when an explosive mixture is set off to force the door open. The escaping gas works rapidly, and a few inhalations of a very small quantity of it will produce unconsciousness. After being exposed to the fumes of the deadly gases there will be little chance left for the burglar to escape. What Weather Does to Cloth \ EATHER conditions have a marked effect upon cloth. Silk resists weather much better than linen. It has been found that heat, light, and moisture weaken cloth of any kind, so that it be- comes less resistant to tearing and changes its color. Leo Vigon, a Frenchman, has found that the wearing of cloths dépends largely upon the resistance of the material to weather conditions. Vigon tested different mate- rials under controlled conditions of tem- perature, and light. He also conducted a number of tests exposing the material to sunlight for various periods. In many of the tests the complete breaking down of the 68 Popular Science Monthly fiber was brought about by exposure to perfectly natural conditions. The next time you have to buy a new suit, blame the weather for helping to destroy your old one. War Tanks as Life-Savers A BRITISH physician has suggested that tanks be used as ambulances during war. In fact, in cases of emergency, the tanks were used to bring in the wounded during the great war. Tanks fitted up as ambulances could bring in wounded men with little danger from stray shells. They would have no trouble in navigating roads that would offer the greatest obstacles to motor-trucks. It is proposed that hammocks and stretchers be arranged in tiers, with an operating-table in the center. Hailstones and Their Power HE destructive power of hailstones has been carefully studied by Paul Martin, a French scientist, in an attempt to ascer- tain the relation between the size and weight of the hailstones and their ability to kill birds, various larger animals, and human beings. M. Martin found that hailstones greatly vary in size, from that of a pepper-seed to that of a baseball. The smallest spheres of ice weigh but a few grains, while some of the largest on record reached a weight of seven or more ounces. Martin deter- mined by observation and calculation that hailstones weighing eight grains or more kill small birds, those weighing twenty- three or twenty-four grains are fatal to quail, those of about forty grains to animals as large as a rabbit, and those attaining a weight of about two ounces will kill human beings. Soil-Freezing Temperature AREFULLY conducted experiments have shown that soil will not freeze at zero temperature unless it is thoroughly agitated. If it is not agitated, it will not freeze at this temperature, no matter how long it is left exposed to it. Sand loam, if left undisturbed, may be exposed to a temperature of several degrees below zero without any sign of freezing. The ther- mometer has shown the temperature of certain soils to be far below the freezing- point without the soil’s actually freezing. News by Radio XPERIMENTS conducted by a news agency in England demonstrated that the distribution of news messages by means of wireless telephony is still an unsolved problem. The voice was perfectly audible, but the transmission of messages took so much time and could be intercepted so easily that the system was abandoned. More promising were the experiments made to test the practicability of using high-speed wireless telegraphy for distribut- ing news and commercial messages-

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June, 1921

Do It with Tools and Machines

In electroplating, the amount of deposit de- pends on the density of the current around the article being plated. This can be determined by the foot-ampere meter above. It shows current density

———<<—<—<— — — — ns Here is a lathe dog that is fitted with a recess into which the set screwhead fits. Thus danger of breaking projecting screws is eliminated. It also prevents accidents since # cannot catch the

clothes of the worker

Formerly metal parts were washed by hand; but the machine above will wash anything from small screw- machine parts to large castings. The parts are placed in wire-mesh racks and streams of water are poured on them A machine that will This grinder is pro- emboss gold or silver vided with a number ~ marks on cloth. The of grinding elements material is placed that enable it to under the stamps, grind material to dif- gold or silver paper ferent degrees of fine- laid on, and pressure ness. It is driven by applied electric motor

Not a microscope, but What is known as a a measuring instru- double-duty microme- ment. Asteel ball is be- ter. It will transform ing measured here; it is an ordinary inside mi- held by three points. crometer into a depth- If it is not uniformly measuring micrometer. rounded, a pointer will It is used, for example, indicate the amount of to measure the depth its deviation of holes in metal

Heretofore emery’ wheels have been used for pointing the ends of bars before in- serting them in screw ma- chines; but the process is slow and costly, hence this bar-pointing machine An electric drill equipped with a switch that operates like a pistol trigger. The handle is also shaped like the handle of an automatic pistol. It will operate on direct or alternating current The machine above will mill the top and bottom of passenger-car cylinder blocks at the rate of two hundred and forty in an eight-hour day. It has a round drum that will accommodate fixtures for six castings 69

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Popular Science Monthly Patch Them while They Are Hot MALL electrical furnaces, gas furnaces, and crucibles are lined with a heat- resisting substance. When this breaks down, the molten metal touches the cold metal of the furnace or crucible, and there is trouble. It used to be difficult to make a repair in the lining of a device while hot. This is no longer true, thanks to a new substance that has been placed on the market. This hot- patching material can be used as soon as the furnace has cooled down enough to allow a workman to come in proximity to it. ; Industrial: wheels move fast, and when machinery falls behind in the race through a breakdown, it is necessary to make a quick repair. A Slide-Rule for the Pocket ROUND slide-rule—that is an innova- tion. The ordinary slide-rule is long and slender. This one is thin and circular. It is equivalent to a slide-rule six inches long, and it can be carried in the pocket, since it is light and requires little space. There is nothing that the long slide-rule ean do that this round slide-rule cannot do. In fact, it has an advantage over the usual type of slide-rule: it is designed and con- structed in a way that it is not affected by changes in temperature. It slips into the vest pocket nicely. Shoehorn, Buttonhook, and Lace-Tipper Combined OW shoes, buttoned shoes, laced shoes —/ —all of them need accessories. There’s the shoehorn, the buttonhook, and the de- vice for putting tips on laces that have lost theirs. All of these things are combined in the new instrument shown above. The button- hook and shoehorn members are hinged so that they may be folded together when not in use. Each of them is grooved near the hinge so that when folded together a hollow space is formed. In this hollow space the tipping is done. The metal tip is curved around the shoe- string by hand and is clamped in place in the manner shown in the picture. Bulbs Frosted while You Wait HEN you go into an electrical supply store now to purchase frosted bulbs, you will not be told to return in an hour or more. A half dozen or a dozen bulbs may be frosted in the twinkling of an eye with the little lead-lined tank shown at the right and a special frosting fluid that acts quickly and leaves no disagreeable odor. It is necessary merely to place the lamps in a rack, as shown, and then to dip them in the solution that has been prepared in the tank, immerse the bulbs for only a few moments, lift them out, and rinse them with clean water. They are then ready for the customer. Experts have assured us that an un- frosted electric-lit globe is most harmful to the eyes. 70 Weighing in a Vacuum N scientific work it is sometimes neces- sary to weigh one part in 100,000,000. Such weighings are usually carried out in a vacuum. The need for making weighings in a vacuum arises primarily from the fact that, owing to its weight, air has a buoyant action on all objects immersed in it. On an equal arm balance, therefore, two objects of the same mass, but of different densities, would not balance each other in. air. Moreover, the density of the air varies with the temperature, the pressure of the barometer, the amount of moisture present in the air, and even the quantity of carbon dioxide present. In establishing our work- ing standards of weight, the buoyancy cor- rection is most uncertain. For all these reasons precision weighings are made in a vacuum. ‘ The balance used by the United States Bureau of Standards is illustrated above A case is placed over the balance, and the air is exhausted. The readings of the beam are then taken through a glass window, the position and movement of the beam in making the weighing being determined from the image of a ruled scale reflected into an observing telescope, by a mirror mounted on the beam. The fundamental standard of mass is a kilogram of platinum irridium, which is one of the densest materials known. This ma- terial was chosen for its hardness. June, ———— A Be AY Iowa been | the fr for se The sheet are ju are né nails. Wh corn, handl placec going germi cover the k are g¢ The W witho into lawn ¢ The these six to on the may t A handl lta and il is nes Throu enclos The mount fence reins their ¢

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June, 1921

A Simple Seed-Corn Tester A BOVE you see a combination seed-corn 44 dryer and germinator devised by an Iowa farmer. The ears of corn that have been selected for seed are stuck on nails on the frame, and left there until time to test for seed. Each nail is numbered. The base of the drying-frame is made of sheet iron filled with small pockets. There are just as many of these pockets as there are nails, and they are numbered like the nails. When the time comes to test the seed corn, the matter is easily and simply handled. Two kernels from each ear are’ placed in the cups, the corn from ear No. 1 going into pocket No. 1, and so on. When germination has been brought about by covering the sheet iron with a wet cloth, the kernels immediately show which ears are good for seed. The Corral Travels Along with the Animals \ HO has not seen droves of stock going quietly along a highway, and, without apparent reason, suddenly dart into wood-lot, grainfield, or cherished lawn or garden? The corral on wheels below obviates all these happenings and peacefully gets from six to twelve or fifteen cattle—depending on their size—to market or fair, as the case may be. A larger number of sheep may be handled at one time with ease. It is about ten by twenty feet in size, and in the rear is arranged a gate that is nearly the full width of the structure. Through this wide gate the stock enter the enclosure. The stock once within, the owner mounts his blanket seat high on the rear fence above the gate, gathers up his long reins and they are all ready to start for their destination. Covered with Pearl Buttons N the East End of London there lives a group of people known as costermongers. For years they have worn distinctive clothes with large pearl buttons. In spite of the fact that pearl buttons worn so con- spicuously as in our picture are not fash- ionable, the costers refuse to give them up. Below you see the coster of costers, Mr. Harry Crop. His best suit is ornamented with sixteen thousand pearl buttons. The buttons are sewed on so that they form various designs. On each trouser leg, for instance, there is a pearl button star with a heart beneath it. The costermongers’ womenfolk have a fondness for velveteen dresses and large hats trimmed with huge ostrich feathers.

hadi Phe dides ty ¢ <taew ew, # ~ . Ak

Experiments in Rain-Making ECENTLY some experiments were made by British aviators in the Trans- vaal in connection with the artificial pro- duction of rain. A biplane, into which were built two sand-boxes containing one hundred pounds of sand, flew above the clouds. The sand was rapidly released, the idea being to cause condensation of the clouds and resultant rain. A Canadian experiment to the same end sprayed liquid air in the clouds. Neither of these schemes proved successful, but they were interesting to watch.

Perfume for a Nickel WELLERS in big cities are familiar with restaurants where it is possibile to obtain a dinner by the coin-in-the-slot plan. There are machines that vend choc- olates, chewing-gum, and stamps. Most of these slot-machines, however, have sold commodities that were sure to have a steady sale. Now we are confronted with a perfume- vending machine, and the inexhaustible field of luxuries is opened up. This invention consists of an inverted bottle and a spring above it. When a nickel is inserted in the slot at the top of the machine, a radial arm presses the coil- spring, which presses the bottle, releasing its stopper, and allowing a few drops of the perfume to fall on the handkerchief held at the outlet at the bottom of the machine. Riding the Boardwalk at Popular Prices ~CONOMY has at last reached the boardwalk. Many people who for- merly rode in beach chairs at fifty cents an hour are now traveling on the electric car shown below at a fare of five trip. This car is merely a modification of the electric baggage-hauler that is seen in many railroad stations. It travels at the rate of eight miles an hour, and will hold about twenty people. Customers wheeling baby carriages may ride in the rear and trail the carriages behind them—no extra charge. The driver will stop the car at any point to let people on or off. On days when the boardwalk is crowded with people, the driver of this strange car must find it very difficult to wend his way through them. cents a

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ae eS bee lye hm Pas ba * = * OR: ip a 4 2 A <*e ee a ey * ~ ae: oF the lock-ring. that the lock cannot be forced into place with the ordinary tools at hand. The rims of wire |

the hood rod. The can has a special spout that enables the driver to pour the oil into the engine without dirtying his hands or With such a can the motorist need never run out of oil, nor be forced to buy an inferior grade or one not suited to his engine because he cannot purchase the proper grade along the road. The can may be thrown away when empty. clothes. Here is an oil-can with a special spout, enabling the user tc avoid soiling his hands or clothes; it holds two quarts of oil are Two-Quart Oil-Can for Motorists NE of the newest conveniences for the automobilist is a two-quart oil-can that can be carried con- veniently under the engine-hood on two clips hung from wheels, which extremely difficult to han- dle on account of their spokes, can be straight- ened most easily by the use of the the new anvil. The garage- man will appreciate this device, as he knows, better than anyone, how often this job must be doneand how muchtime and labor it takes. Popular Science Monthly Taking Out the Kinks in Rims EW jobs are so difficult to handle with the average garage equipment as the straightening of rim kinks, The new rim anvil shown below is the only device on the market that will take care of rims of every type and size. The anvil consists of a solid block of gray iron with a variety of grooves and faces to accommodate rims of every kind in a vertical or horizontal position. Two hand tools are used in connection with the anvil to straighten the rims against the different grooves. Every type of rim presents a problem of its own. Driv- ing to the nearest garage on clincher rims as a result of a blowout often results in bending the edges of the rim to such a degree that the beads of the tire cannot be inserted. In putting a new tire on a rim of the lock-ring type, the rim is often so pounded that it is impossible to insert Split rims are apt to become so sprung

FACES AND ALL SIZES OF RIMS Ad FOR

This anvil for straightening tire rims consists of a solid block of gray iron having grooves and faces of various shapes for accommodating every kind of rim; two tools are used in connection with the anvil This New Automobile Revives the Friction Drive HE friction drive, which was used almost exclusively in the early automobiles, and in which the power of the engine is transmitted to the rear axle by the friction between two circular disks, one at right angles to the other, has been revived in a new make of automobile that, in general appearance, looks like any other. The friction drive takes the place of the regular gearset or gear transmission and the clutch of the conventional car. Its chief advantage is that it per- mits of a large number of varying reductions with a very simple mechanism. The number of reductions avail- able to suit the conditions of road, grade, and carload is almost infinite, although in actual practice these reduc- tions are limited because the lever by which the driving disk slides across the face of the driven disk is held in position by a latch in a sector with a certain number of notches. However, the num- ber of these is greater than three or four as obtainable in

the conventional sliding gearset now in most common use. The friction drive has two other advantages: the gear changing is noiseless at all speeds, and the shocks due to the grabbing or too sudden en- gagement of the clutch are eliminated because no clutch is necessary. In previous forms of friction-driven cars the driving gears were generally placed directly in back of the engine with final double side-chain drive to the rear wheels as on some of the INTERNAL §f GEARS

In this new car, which revives the principle of the friction drive, gear-changing is noiseless at all speeds 72 heavy sizes of motor-trucks. jection of the noisy side chains has been eliminated in the new car shown herewith by placing the driving gears entirely within the rear axle, where they are out of the way and dirt-free. The manipulation of the driving means is effected through a_ pedal located to correspond with the clutch pedal in the ordinary car. holds this pedal in whatever position it is set, although by rocking it the ratchet is released and the pedal returns The ob- A ratchet to normal position. The driving disk is of metal] and is mounted on the rear end of the propeller-shaft. The driven disk, although also made of metal, is faced with a renewable fiber or mill- board rim around its outer edge. It is slidably mounted on the axle jack-shaft. To obtain the different car speeds, the driven disk is slid across the face of the driving disk, the relation of its point of contact to the center point of the driving disk de- termining the car’s speed.

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UT thi stolen i year 1¢ sible, y New confirm It is mobile license- motor tifying automo an ap change’ new lic the fee. Tom a licens Frank automc New Y vice to ing-whe ated 01 on the any tre device theft, | or lice! end is fact th: motor license- registré car cal use of t over tk centive A W, not gi here is driving ming. two re lamp-e Bot lamp-e to any single The re above bu th hidden This p bulb, horizo1 cannot The secures flector ical be

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hly 1S Ze KS, he Ze, of nd c a yb- 1ag wn ars ore ee, ng jal 1et on he “ns ‘he nd nd ‘he lso ith ill- ter ed To car lid ing int ter de- June, 1921 Know Your Own Car Its identification can now be made absolutely sure UTOMOBILES valued at more than ten million dollars were stolen in New York state alone in the year 1919! This hardly seems pos- sible, yet facts from the office of the New York Secretary of State confirm it. It is now possible for an auto- mobile thief, having removed the license-plates and changed the motor number and other iden- tifying marks, to appear at the - automobile bureau and, by filing an application carrying the changed motor number, to obtain new license-plates on payment of the fee. To make it impossible to secure a license on a stolen automobile, Frank Wenzel, in charge of the automobile bureau at Albany, New York, has perfected a de- vice to be attached to the steer- ing-wheel of each motor vehicle oper- ated on the highways and so placed on the vehicle as to be easily seen by any traffic officer or patrolman. This device is not intended to prevent theft, but to prevent the registration or licensing of the stolen car. This end is accomplished by reason of the fact that it is not possible to operate a motor vehicle in any state without license-plates as evidence of proper registration. Therefore, if the stolen car cannot be registered through the use of the device, it cannot be operated over the highways and there is no in- centive for any one to steal it, since its unauthorized possession will afford no financial reward. The device consists of two metal clamps, so made that they can be fastened around the rim of the steering- SECRET KEY-NUMBER | (ON UNDER SIDE) \ END CLAMPS (AROUND RIM) > In the new device engine number and state seal are embedded in the upper surface, while a secret key number corresponds to a complete description at the registration office wheel, and held in place by screws -through the rim. An immutable sub- stance, plastic in nature, is applied in the form of a tape between the two ends of the clamps. In this material are stamped the engine number and the state seal on the upper surface and a secret key number on the under side. This key number corresponds to files kept in the registration office, where a complete description of the vehicle is on file. When a thief attempts to steal a car carrying this device, he must not only embed a new engine or car num- ber and state seal in a substitute ele- ment, but he must be wise enough to An Automobile Light with Four Ranges HEREAS the average automo- bile light, when dimmed, does not give sufficient light for driving, here is a new lamp that meets all the driving requirements without dim- ming. This is accomplished by using two reflectors instead of one in each lamp-case. Both reflectors are fastened to the lamp-cover plate, which may be fitted to any make of lamp after the original single reflector has been removed. The reflectors are placed one above the other. The bulb in -per reflector is visible, bu that in the lower one is hidden by the cover plate. This plate not only hides the bulb, but cuts off the light horizontally, so that glare cannot possibly reach the eye. The first range of light is secured from the upper re- the road ahead for five hundred feet. This is for country driving. The second range is that of the lower reflector. It is used for city driving or when passing other cars on country roads. It meets all traffic regulations in cities and throws a beam one hundred and seventy-five feet ahead without rising above a height of forty-two inches, as required by law. The third range is used when an substitute a code number corresponding with the secret key number on the bot- tom of the unchangeable strip of metal. This is, of course, very unlikely to happen. The thief’s troubles are fur- ther aggravated by reason of the fact that any attempt to change the original number of the top of the strip results in the destruc- tion of the chemical element used. The device may be applied to any type of steering-wheel and in no way interferes with the operation of the car. Mr. Wenzel has also developed a machine for embedding the identifying data without removing the steering- wheel from the car. This con- sists of a framework with three arms, and calibrating and num- ber-cutting appliances to hold any size of wheel and apply the numbers at the same time. The use of such a machine would become necessary if Mr. Wenzel’s plan were adopted, for every vehicle on the road would have to have the identifying date or make its owner subject to arrest. If the same kind of identification were not adopted by other states, a vehicle without it when coming into New York would have to stop and have the data applied before proceeding. This would be entirely possible, for the machine could apply the data in less than twenty minutes. The inventor estimates the cost of application of the device at not more than one dollar and a half. Li HT C aid aa LOWER RE Front View “Side View Bo) EE | inst Third Range —ESE ee Fourth Range, Lange Second Rande 6b The first range lights the road flector, and consists of a con- leal beam of light that lights This new glareless headlight throws a beam so arranged that it will not blind other drivers 73 for 500 feet, the second 175 feet; the third gives a very bright beam, the fourth a dim light especially powerful ray is re- quired, and then both upper and lower lamps are lit. The fourth range is that of the lower reflector, with the lamp dimmed by resistance. This range is for use in park- ing, and consumes less than two amperes of current.

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Popular Science Month, @ June, 18 How Inventors Foil Prevent the theft of your car ‘ by ad © Underwood & Underwood The clever automobile thief gener- One man actually carries ally carries a ring full of master a dummy around with skeleton keys for picking all types him and props it up to of the common ignition-switch lock. scare off the thieves. Although almost every make of car Some day he will find both is supplied with a patent lock, it is the car and the lady gone the thief’s first and best bet Petty thieves who make a practice of stealing moto- meters from radiator caps will have to turn their attention P eee to some other more easily —— — Still another method, which is A simple device for thwarting removable accessory if the the thief. When locked in motometer is protected by crude yet effective. It is accom- place, this sharp-pointed in- the new device shown above plished by chaining and locking strument makes it almost im- the steering knuckle and drag possible to drive or tow the link of a motor-truck to prevent car without attracting attention a thief from driving it away Grounding the magneto by dis- connecting one of the spark dis- tributor wires, makes the engine inoperative, but does not prevent The ignition-switch lock is per- haps the most common of all automobile-theft preventives since it is usually furnished with the car as purchased. However, The driver carries this removable gear- the car from being towed and almost any key that will open shift lever with him when he leaves the steered. Ordinarily the thief the lock makes it ineffective car. When the real lever is removed, easily finds a disconnected wire a fake one is inserted in its place 74

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1, HR June, 1921 | Automobile Thieves = ar ' by adopting one of the many d) described on these two pages © Underwood & Underwood The car once stolen and While most people who lock the doors taken to a garage or an of their closed cars think they are then unfrequented road, it is entirely safe, this shows how the in- easy for the thief to genious thief may cut a hole in the remove the identifying glass panel. Then unlocking the door engine number and starting the car are easy © Underwood & Underwood Once you have taken out the inside distributor arm and put it in your pocket, it is impossible for any one else to start the en- gine until the arm is put back or a duplicate in- serted © Underwood & Underwood Que A rod, hinged to the front seat riser and locked around the gearshift lever, prevents gears from being shifted. The rod is swung out of the way when not in use Spectacular but hardly practicable is this electrically operated ankle vise to grab the thief when he presses the starter pedal in at- tempting to get the engine started © Underwood & Underwood Clumsy, but this method of An unusual method is to place Built into the car at the factory, chaining the tilting steering- a special valve in the gasoline this out-of-the-way lock pre- wheel to the post so that the line near the tank to shut off vents the gears from being car cannot be guided from the fuel, although enough remains in shifted out of neutral, so that driver’s seat, even if towed, the carburetor or vacuum tank the engine, even if made to run, makes the thief think twice to run the car a short distance cannot propel the car 75

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This contrivance for keeping the driver cool literally scoops up fresh air and throws it at his feet Cool Breezes for the Driver ~VEN with the wind-shield open, on a hot day that 4 portion of the automobile driver’s compartment between the floorboards and the cow! gets little, if any, ventilation. On long drives this pocketed air is heated by close proximity to the engine and causes great discomfort to the driver. This inconvenience may be eliminated by the fitting of a cowl ventilator. The device consists of an adjustable baffle-plate that is inserted in the top of the cowl in front of the wind-shield.- It literally scoops up fresh air and throws it at the driver’s feet. When the baffle-plate is closed, the ventilator is waterproof and dustproof. In fitting to the hole cut in the cowl, two base plates are used, one on top and one underneath the cowl metal and thus forming a clamp around the edges of the opening. The oper- ation of the baffle-plate is con- trolled by a small rod with a nickel-plated knob extended through the dashboard. Illuminating the Driver’s Hand at Night as AUTION” in large black letters / on ared background glows sud- denly from the driver’s side of the automobile in front. You observe due caution, and presently he swings to the left in the direction of a side street. All’s well. That caution signal was attached to the back of his hand by means of a strap that fastened across the palm; the glow was caused by a small electric flash-lamp attached to it. When the driver approached the corner that he intended to turn, he pressed a push- button on the battery-box, thus turn- ing on the light. It is almost impos- sible to see a driver’s extended hand at night, and as a result many accidents have occurred. This new caution signal, which was invented by Wesley Kuhlmann, of Guttenberg, New Jersey, does not hamper the driver in any way. He is well able to handle the wheel. For night driving there is now an illuminated cau- tion signal that the driver of an automobile wears on the back of his hand In this six-wheeled gasoline-electric motor-truck, each of the four rear wheels is driven by an electric motor 76 Popular Science Monthly Clean Gasoline in the Carburetor} ASOLINE fuel accumulates water, dirt, and othe : The dirt and water are aot sep- 3 insoluble products. arated until they reach the needle-valve of the carburetor, It was to overcome such trouble that a Buffalo concern perfected a combination gasoline purifier placed in the gasoline line at the en- gine. It removes all impurities just before the fuel enters the carbu- SUPPORT ROD FROM ENGINE retor. The purifier can ox ° DIRT 7 be applied to any type of GASOLINE f FROM TANK gasoline engine. It con- sists of a bowl-like cham- SSG ber in which the fuel , ae) PURE GA NE TO CARB T passes successively through three screens of sixty-mesh wire screening, silk, and chamois in the order given. Thus the gasoline is freed of all impurities, including water. The removal of the water also prevents freezing of the gasoline line in the winter. The use of the purifier also re- duces repairs, in that when the engine operates spasmodically or unevenly because of dirt getting under the needle-valve, additional strains are set up. CLEAN-OUT PLUG Acombination gasoline purifier that removes impurities in the fuel just before it enters the carburetor A Gasoline-Electric Motor-Truck ANY unusual and almost revolutionary ideas have been incorporated in this six-wheeled gasoline- electric motor-truck perfected by E. W. Weaver and T.S.E Kemble, two Cleveland automotive engineers. & Its designers claim it has successfully passed the in fuel mileage over the conventional five-ton gasoline-consuming truck. Four electric motors drive the four rear wheel, each independent of the other. pivoted on a dead axle and is linked to the frame after the manner of the street-car. an hour. This variance is said to be obtained through a con- troller that reg- ulates the gener- ator and the motors. most rigid tests and showed a 33-per-cent increase & Each motor if Tests are said to show that this truck, carrying > five tons, travels at thirty miles an hour on leve™ roads, or climbs a 45-per-cent grade at five miley June. . IG BS te a fleet ¢ trucks a haul: in one cities. Bill wa the ge ger’s of account steward fleet of $300,00 pened t “Wel biggest have dc has bee duction repair s: system saved u the cost repairs nance.” “But “at's “Last yi truck, i repairs, | days, di for over for sligh time. B the num reduced days a: lost time ing defe running | a genera truck. “The } is a simy pair wor as the en;

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ati, is June. 1921 Repair Your Trucks on the Unit Plan Thus you can easily save thousands of dollars a year IG Bill Butler B was the main- tenance boss of a fleet of fifty motor- trucks operated by a haulage company in one of our big cities. The day Big Bill was called into the general mana- ger’s office to give an account of his year’s stewardship of the fleet of trucks worth $300,000, I hap- pened to be present. “Well, boss, the biggest thing we have done this year has been the intro- duction of the unit repair system. This system alone _ has saved us $31,625 in the cost of our truck repairs and mainte- nance.” “But how?” I broke in. explained Bill. “Last year the average time lost on a truck, in overhauling and running repairs, Was approximately thirty-nine days, divided into twenty-four days “It’s this way,” By Joseph Brinker What the Unit Plan Is Suppose you own fifty trucks. If you are making repairs on the old plan of overhauling once a year and of handling emergencies as they arise, the number of idle days for each truck is something like forty an- nually, a yearly maintenance cost of nearly $900 for each truck. This has been reduced by one fleet-owner to $225. How? By the unit plan. The idea is to have on hand a number of truck units—engine, clutch, gearset, and rear axle. In the case of the fleet mentioned, the forty days formerly lost annually has been reduced to ten. Of course, this system of unit repairing presup- poses the use of one make of truck, or at least of trucks using standardized units. rear axle, instead of on the vehicle as a whole. Complete units are always kept on hand, ready to be installed in any truck the moment it is brought into the shop with any of these units needing extensive repairs. The old or for overhauling and fifteen days for slight repairs from time to time. By the unit repair system, the number of idle days has been reduced from thirty-nine to ten The ten days of lost time are consumed in replac- ing defective truck parts, minor - running repairs, tire changes, and a general tightening up of the days a year. truck. “The unit truck-repair system is a simple one in which the re- pair work is done on units, such as the engine, clutch, gearset, and or regulate the carburetor. to the engine, it concerns the replace- ment of the main engine bearings, wrist-pin bearings, and the repair of the lubrication system.”’ The general damaged unit can be removed from the chassis and the new one installed in a fraction of the time it would take to make the repairs on the damaged unit while it remained in place on the truck itself. This means a great saving in the time the truck is out of service for repairs; for practically any, or even all, of the units can be removed and others installed in from four hours to two days. “Of course, this does not mean tak- ing out parts merely to grind in the valves, clean the spark-plugs, adjust the timing system, Referring Manager opened one AAADBAARK SABHBABS *200 COST OF REPAIR WORK, LABOR,AND PARTS COST OF IDLE TRUCK TIME WHILE IN SHOP AT $35 A DAY [S-TON TRUCK ] ENGINE FIXED IN TRUCK cN oS $|2 ' OF CHANGING ENGINES COST OF IDLE TRUCK TIME SAVED BY UNIT REPAIR METHOD ABA BADBADARDOASSALAD 19250 The Diference between the Old and the New Systems Above you see a truck that is being repaired in the old hit-or-miss way handling each piece of repair work as it comes along. The six days of idleness while the truck is in the shop amounts in money to $210, and the repairs cost TRUCK OUT, 4 HOURS LATER $200. ,|¢ AMAGED ENGINE Ere ae ABAD ABCABAKAABAABRASSA £210 Contrast this with the truck in the By having the unit all ready to take the place of the broken one, the saving in money amounts to $192.50, and the truck is out of the shop in four hours instead of six days lower picture. TRUCK OUT, SIX DAYS LATER

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of the large ledgers on his desk and read: One rear axle in perfect condi- ‘It is not so much the cost of re- = take care of fifteen rucks pairs that eat into our profits as it is the possible profits that we could earn while the truck is out of service undergoing re- pairs. An idle truck is a very expensive piece of machinery. The possible earnings that might be made by the truck were it fit for service on the road are often greater than the actual bo cost of the repair work, and amount to Engine trouble is more com- alarming proportions as soon as the mon—one engine for every size of the fleet grows to twenty-five or fifty trucks. Are the Bearings Burned Out? ‘For example, let us take a five-ton truck that is brought into the shop with burned-out bearings due to a lack of lubricating oil or to a failure of the lubrication system to function prop- erly. If no scored cylinders or pistons resulted from the lack of lubrication and only new bearings had to be fitted, it would take two men approximately six days to remove the engine from the frame, take it apart, replace the burned bearings with new ones, put back the engine in the frame, and run the engine in before sending the truck out for road work. A complete renewal of.the bearings would cost in the neighborhood of $50 and the labor about §150, making the entire job cost about $200. “If the truck with its body were kept in the shop while the engine was being repaired, it would be out of service for six days. Since a five-ton truck is worth $35 a day, this would mean a loss of $210 for the cost of the idle truck time. This is in excess of the actual cost of labor and materials on the repair work. “By the unit system of repair method, the complete engine may be removed at a cost of $12 within four hours, and the truck sent out ready to work, with a delay of but four hours. At the truck value of $35 a day, the four-hour lay-up for the transference of the two engines would be worth only $17.50, re- sulting in a net saving of idle truck time of $192.50, as compared with the usual method of repair by which the truck is kept in the shop until the engine originally dam- aged is repaired and replaced.” Here Big Bill broke in to say: “But the saving in idle truck time is not the only advantage of the unit repair system. It has helped me to reduce the actual cost of the repair work and to keep my shop force fairly constant. As long as the trucks are out on the road, working, the repair work on the units in the shop may be done on a regular routine and without alternate rush and slack periods. “The number of units to be kept on hand depends to a large extent on the degree of standardization of the truck fleet itself or the number of different makes or models. “If two or three different makes of five-ton trucks are employed, as well as two or three different makes of smaller trucks, ten trucks is about right It has been esti- mated that one spare clutch takes care of some fifteen motor-trucks The gearset gives least trouble —one gearset will carry repairs on twenty trucks How Many Spare Parts Do You Need? Here is how the unit plan of truck repairs works out. By arriving at a system of averages for a given number of trucks, and keeping on hand units ready to place in the truck needing repairs, it is possible to reduce idle truck time to a minimum. Not the least important item is the fact that the work of special mechanics is systematized and made highly efficient 78 Popular Science Monthly June, 19. it is obV spare un: supply t our case, trucks of gears et, ] are all al of the fle three cor three gee our fifty units wo twenty-f “The » does not quantity must be necessar’ when it 1 damagec insertion S “Due truck m: to adhe garding the vari time to | order to system ;¢ ber of n ' the stea done uj mechani and a te Q.- from bent : of the L. A. unde aspa wire must 0.- Ford engin is inc A. emp] brigh beca fly-w speer Ho: Q.- heavy no ¢r cars, seven Tex A: Cars Ditties

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JS tes eS iN a J mw ai) WL Ab | done upon a schedule basis. June, 1921 it is obvious that a large number of spare units must be kept on hand to supply the different makes. But in our case, since we use only five-ton trucks of one make, the engine, clutch, gearset, rear axle, etc., for each truck are all alike. By this standardization of the fleet unit, we have to carry only three complete engines, three clutches, three gearsets, and three rear axles for our fifty trucks; and this number of units would probably be enough for twenty-five more trucks. “The use of the unit repair system does not make it possible to reduce the quantity of individual small parts that must be kept on hand. These are necessary for emergency repairs, or when it is necessary to quickly put the damaged units in first-class shape for insertion in some other chassis. Some of the Advantages “Due to the unit repair system of truck maintenance, it is possible for us ' to adhere to a definite schedule re- garding the time of replacing units in the various trucks and at the same time to have complete units on hand in order to anticipate emergencies. This | system also serves to reduce the num- ber of mechanics required, because of the steadiness of the repair work when Six mechanics, not including the foreman and a tester, are all that are needed to maintain our fleet of fifty trucks. Two of the men are used for inspection and rear axle work, two for engine work only, one for gearset work, and one for general work in the blacksmith shop. ‘‘Under the former system of annual overhaul, we had to have at least four- teen men properly to maintain the trucks, in comparison with the six mechanics now required, working un- der the unit repair system. Under the old system men working on trucks in their annual overhaul were continu- ally interrupted in their work by hav- ing to carry out emergency repairs.”’ “The principles of the unit repair system are the same the country over,” interrupted the general manager, ‘‘al- though it is difficult to set any fixed rule to determine the number of spare units required for any fleet until a study is made of the particular work which that fleet has to perform. ‘“‘However, in some cases where assembled trucks are used, it is often possible to reduce the number of units necessary by selecting trucks of differ- ent makes that are equipped with the same make and size of component parts, such as the engine, clutch, gear- set, and rear axle. For example, one make of truck of two tons capacity, designed to run at high speed, may be fitted with the same make and size of engine as used in a four-tonner de- signed to run at a lower speed. Thus one spare engine would serve as a service unit for these two trucks of different capacities. “In our particular case, with three spare units of engine, clutch, gearset, and rear axle for a fleet of fifty trucks, we carry one of each of these units to approximately seventeen trucks. How Many Parts to Carry “For example, a fleet of 700 one-ton trucks employs one spare engine and one rear axle for every ten trucks. By the unit repair system 50 per cent of the time formerly spent for main- tenance has been saved. The com- plete disassembling and reassembling of units that have already been repaired require from seven to eight days, in- cluding a painting of the body, as compared with from sixteen to eighteen days of individual repairing. “With the 700 trucks, all of the same make and size, my friend has been able to carry the unit repair system one step further, namely, in carrying out the repair work on each particular unit. The saving of time by this sys- tem has been nearly 40 hours on each power plant overhaul. By specializing repairs on each unit the overhauling and assembling of an engine takes but 814 hours. This time compares with 3 days under the ordinary system of placing the responsibility of these operations in the hands of more than one special group of men. Broken Spark-Plug Wires Q.—How can I prevent spark-plug wires from breaking at the point where they are bent around to hold under the terminal nut of the center electrode of the spark-plug?— L. A. H., Brooklyn, N. Y A.—When placing a wire terminal under a terminal nut such as is used on a spark-plug, be sure to twist or turn the wire in the same direction as the nut must be turned to tighten it up. Dim Lights on Fords Q.—Please explain why the lights ona Ford car appear to burn brighter when the engine is speeded up or the speed of the car is increased. —X. D., Newark, N. J. A.—Unless some form of regulator is employed, the Ford lights do burn brighter when the engine is speeded up because the current is secured from the fly-wheel generator and varies with the speed of the engine. Horsepower of Truck-Engines Q.—Please explain how it is possible for heavy motor-trucks fitted with engines of no greater horsepower than some passenger- cars, to move heavy loads of from five to _ and a half tons.—H. F., Fort Worth, ex, A.—The engines of both passenger- : cars and trucks perform work when —— they cause the vehicles to move. Work may be defined as force multiplied by space, and power as the rate of work. Power exerted for a certain time pro- duces work. The unit of work is the foot pound, or the amount of work done in overcoming a pressure or weight equal to one pound through one foot of space. The most common unit of power is the horsepower, which is equivalent to 33,000 foot pounds a minute. In the passenger-car, the power of any given engine moves a small weight very quickly, while in the motor-truck, through a system of gear- ing, the power of thesame engine is utilized to move a larger weight more slowly, the amount of work done be- ing the same in both cases. Causes of Engine Heating Q.—What are the most common causes of automobile-engine overheating ?—A. X., Pat- erson, N. J A.—The most common causes of engine overheating in the usual order of their importance are a loose fan belt; inadequate water supply in the cooling system, or a leaky radiator; clogged water jackets or hose connections; in- sufficient oil or old oil; incorrect spark advance and carbon in the cylinders. Write to Us About Your Motor Troubles The Popular Science Monthly invites you to send your auto- mobile problems to the Automobile Editor. He can tell you anything you want to know about a car, and he is here to help you Detecting Binding Brakes Q.—If the engine seems to lack power or the car does not pick up speed and the trouble is diagnosed as slightly binding brakes, what is the simplest method to dis- cover if this is the real trouble?—Q. B., Atlanta, Ga. A.—Aside from the inspection of the brakes while another person operates the pedal and lever, one of the easiest methods is to throw out the clutch and let the car coast down a hill. If the brakes are free, it will coast easily and pick up speed. If the brakes are bind- ing slightly, they will tend to hold the car back and reduce its speed. Horsepower-Weight Ratios Q.—Is there a fixed ratio between engine horsepower and weight of the passenger automobile and motor-truck, and if so, what are the most usual ratios for the two types of vehicles?—J. S., Los Angeles, Cal. A.—There are no definite fixed ratios between horsepower and weight, these varying according to the design of the car and the purposes for which it is in- tended. Some speedy passenger-cars have 1 hp. each 50 or 100 lbs. of weight. Others have 1 hp. each 150 lbs. weight, and the ratio increases up to 1 hp. each 300 or 400 lbs. of weight in slower- speed trucks of large capacity. 79

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Have You a Propeller-Driven Below is given a detailed description of Streamlined like the fuselage of an airplane, the graceful body of this car ends in the rear with a sharp, vertically placed wedge-shaped tail HE pictures shown are of an aerial-propeller-driven cycle-car that can be built by the amateur. The framework of the body is of white pine covered with 28-gage galvanized sheet iron. The curved side pieces must be soaked in water before they can be bent into the right shape. The floorboards are of 1-in. soft pine, nailed to the bottom of Place two or three extra-strong cross cleats underneath the floorboards. When the floor- boards have been securely nailed in place, strips of heavy sheet metal (about 20 gage) are bent in the middle to form a right angle. One part of each strip is nailed directly under a cross cleat, and the other part projects upward so that the uprights of the framework may be nailed to them. These metal strips should be about the same width as the cleats above them and 6 or 7 in. long. the cross cleats. Uprights and Struts When the bottom is complete, the uprights are nailed to the projecting strips of sheet metal. The length of these uprights is most easily deter- mined after they are put in place, so it is better to leave them slightly longer than necessary and they may be cut the required length when the curved strut is nailed across the top. This strut must be steamed or soaked in water. It is first fastened into place at the rear and is nailed to the uprights in succession from the rear to the front. Board No. 3, Fig. 2, is about 6 in. wide, so that a vertical slot may be cut in it for the front axle. A slot must also be made for the tie-rod. Board No. 4, Fig. 2, is 7 in. wide and has a similar slot for the rear axle, but is a trifle wider, since the rear axle has a larger diameter. The uprights num- bered 2 must be of extra strong wood, By Edward M. Folkerts as the channel-iron wishbones that hold the axles in place are fastened to these. Piece No. 5 is cut from 2 3 in. stock. After all the uprights and the two curved struts across the top have been put in place, two narrow triangular strips of white pine are nailed on top of the struts along their full length. Cross pieces are now put through the upper side of the framework. These in. by in a wedge, but it is slightly convex and is placed horizontally. The air pressure increases the stability need not be wider than 1!4% in. and to these the boards in the shape of a seg- ment of a circle, forming the curved shape of the top side of the body, are nailed. A rounding piece is fastened to the rear of the bottom, and the corners of the opening in the top are filled in. The running gear consists of four motorcycle wheels. Gas-pipes are used for axles and steering apparatus connections. A 114-in. pipe is used for the rear axle and it is held in place by the two wishbone-shaped channel irons. The front axle is of 1-in. pipe cut in halves and joined by a loose-fit- 2) a one SS C tre SPIPCS yr SLOT FOR FRONT AXLE FIG. 2 There is nothing complicated in the construction of this car. The two diagrams give all the dimensions neces- sary to guide the amateur builder 80 Popular Science Monthly Cycle-Car? how to build one Built on racer lines, this propeller- driven car presents an extremely grace- ful appearance as it skims over the ground with surprising speed ting coupling. The coupling allows either front wheel to go above or below the level of its mate without any ten- dency of the axle and wishbones to bind. A 1-in. tee is screwed on each end of the axle and through these tees 34-in. nipples are put. (The tees are filled with Babbitt-metal to form a smooth bearing.) To the lower end ot the nipple through the tee is attached an elbow into which is screwed another nipple, which serves as a spindle for the front wheel. To the upper end of the nipple through the tee is attached another elbow facing to the rear. In this elbow is attached a -in. pipe by the use of a bushing. The 1!4-in. pipe serves as the arm or lever to which the tie-rod is attached. A set of gears from a discarded lawn-mower will serve for the steering apparatus. Power and Propeller The power is furnished by a twin-f cylinder motorcycle engine supported at the rear end of the body on four 34-in. pipes. The gasoline tank is placed in the front end of the body and the fuel is forced to the carburetor by air pressure. The propeller is attached F to the sprocket wheel of the motor by bolts. First a heavy metal washer about 5 in. in diameter is placed against the outer side of the sprocket wheel and holes are drilled through the washer for the propeller bolts between the sprocket teeth. The heads of the bolts are then hooked over the edges 0! the sprocket teeth and the propeller is afterward clamped tightly agains the washer. A propeller can be procured from al airplane factory or can be carved from left to the discretion of the builder. A cycle-car of this type will carry tw passengers at a maximum speed of 3! gallon of fuel unless road condition are exceptionally bad. a (YO I ot tive ar light w tive Pp locom clock-s old eig (See dri tion of The volve 1 turntak spring. wheel ¢ tive gt turnté catch C the tak a half t caught opposit purpose bumper locomot Sil EL¢ ala made re tact pos wood to row stri two tips is show) BR: \ A =A J ~, ie ! Wy 2 Trespa String against asmall ¢] . _ of € two pthe circy 4 by 6in. stock. Brakes and lights are sides of t cord was the pate] small pos miles an hour at about 35 miles onif Engage trespasser from b ty

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thly

llows elow ten- PS to each > tees $ are rm a nd of iched other e for nd of iched In pe by _ pipe h the ‘from ve for twin- yorted 1 four nk 3s |v and tor by ached & tor by vasher & placed rocket gh the F ot weell of the iges of opeller ig ainst d from hts ate® sides of the washer B strong fine black der. Try two d of 36 small posts, also concealed. Engaged by the feet and legs of the ditions trespas-er, the fiber clip was jerked p from between the brass tongues of the es Onde

4 Re ae | made ready in an evening. - 2 BLACK CORD es 4 fe SO OO tna rclitin ns hie e-— fon wm +h ieee t BUZZER is a a = om Pim | fe Mee ote ty _[ sae a MELON PATCH = tise aa Pen = 41 i | = a... | Se ee, | Tee ee RR Coo | | CARDBOARD SLIP /BLACK CORD ——__ CONTACT POST Trespassers cannot see the black : _ of fiber was slipped between rom an & June, 1921 Making a Turntable for a Toy Locomotive CONSTRUCTED | both the locomo- tive and turntable of light wood. The mo- tive power for the locomotive was a clock-spring from an old eight-day clock. (See drawings for posi- tion of spring.) By F. E. Brimmer GUARD BUMPER |

DRIVE - WHEEL TRUCKS WITHOUT BODY / The power to re- volve the automatic turntable was a similar spring. When the rear wheel of the locomo- tive goes upon the turntable, it trips catch C, which permits the table to revolve a half turn, when it is &, wrt caught in place. by the -~vt swarr opposite catch. The purpose of the guard bumper is to stop the locomotive when it PINS TRIP CATCHES after a half Silently Guarding the Melon Patch ELOW is shown the details of an alarm that was rigged up and The con- tact post, consisting of a small stick of wood to which were attached two nar- row strips of brass, sprung so that the two tips pressed quite firmly together, isshown at A. This was concealed in BRASS STRIPS A fic: , ta \ CONTACT POST

o

string in the dark, and by running against it they release the alarm asmall clump of uncut weeds. A small € two tongues of the post to keep the circuit broken. From the two cord was stretched across two sides of , the Patch and secured to two other ‘CLOCK SPRING (8G WHEEL

Lcuock ‘SPRING \ COG WHEEL Starting on a straight track, the loco- motive will run on the turntable, which will automatically revolve, stopping gets on to the table and to hold it station- ary until the table has revolved. The front of the locomotive rubs against the guard bumper always. When the turntable catches on the half

CATCHES WHICH REAR WKEEL ff turn, the engine is

TRIPS TO REVOLVE LOCOMOTIVE

CLOCK. SPRING - A . kz \ Le | The stand here shown in two eleva- tions has a round top, but it may also be made with a square top best be glued together, with three dowels in the glue joint for strength. Cut the legs to the sizes shown in the drawing and square the ends carefully. The upper cross pieces and the base pieces are fitted with a cross lap joint. Fasten the base together with two 34-in. flat-head screws. Sandpaper all the pieces thoroughly and assemble. The top is fastened in place with four 34 by 2 in. pieces of brass about 18 gage. One end of each brass piece is fastened to the upper cross piece and the other end is screwed tothe top. If the amateur carpenter desires, he may make the top square. The finish should be a good oil stain. Conclude the finishing process with two coats of wax.--M. TOCABEN.

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Provide a Junction Box for Electric Utensils ODAY it is quite the usual thing to find the housewife using an elec- tric toaster, an electric coffee percola- tor, and even an electric motor-driven Necessarily this makes a egg-beater.

may use the electric current for one, two, or three purposes need for some sort of a junction box in the kitchen to distribute the current. Herewith is an illustration of one that the writer fitted up out of some every-day equipment. A white pine board, 6 in. by 7¢ in. by 16 in., was cut out to take three standard base receptacles with closing covers. These were mounted in place without the pressed-steel wall-box and the three wired in parallel. The whole was mounted on two brackets arranged to swing from the wall as shown. Counting labor and time, it repre- sents a cost of $7.65 and is well worth every penny. The leading wires not shown were connected by a heavy flexible cord with a circuit in the cellar.—W. B. BENNETT. Making a Bird-Bath from a Roasting-Pan SING such materials as he found in cellar and attic, a young stu- dent of landscape gardening made the bird-bath pictured below. The upper and lower platforms and the square post that supports the upper one were made from boards taken from a discard- ed wooden bed. The four small posts at the foot are knobs from the old four-poster. The bath itself

is the lower half of an oval iron roasting- The little birds wit Pan, of the type greatly appreciate having the this bath center of the bottom raised and surrounded by a trough for the drippings. The use of a pan of this

type provides water of two depths, shallow in the center and deep around the rim. When finished, the entire outfit, bath and support, was given several coats of white paint. A Hardwood Scraper from an Old Plane Bit HEN you are in need of a good scraper for particular jobs, make one like the one shown in the illustra- tion. The bit, ground to a thick bevel, is fastened by means of a_ screw L_.. through a small piece of sheet iron to a handle fashioned from 2-in. material. This scraper, instead of merely scraping the surface, takes off a thin shaving, and there is no danger of running too deep. This tool, which

Popular Science Monthly Made of Cardboard Is This Brush and Pencil Rack N excellent brush and pencil rack is made with corrugated exrd- board mounted or glued on to a block of wood or cardboard box. The card- board is cut the desired length snq width and a second one the same <ize and shape is glued on to the first, but

a # ; a 5 “i - Yaa ‘ - pre * A es Mt vi / é Be eth

Woodworkers will find a scraper like that here described a valuable addi- tion to their stock of tools any mechanic can easily make in a short time, will prove to be a valu- able addition to the tools of any woodworker.—-DALE R. VAN Horn. How to Keep a Clothesline on Its Pole N windy weather it frequently hap- pens that the violent swaying of the heavy load on the clothesline causes it to slip from the notch in the support- ing pole. The result is usually disastrous and part of the washing has to be done over. Such acci- f_ ROPE

pac WIRE

dents may be 4 2 prevented by STAPLE providing the poles with sup- porting hooks. Bore a hole re » ize Ui, -7T\ I) woopEn = 78 _ he ALAN WZ “POLE rill diagonally | | through the Wo Non ia pole, about 2 This line-clamp on in. from the the end of the ‘ clothes-pole will top, insert a prevent some of the wire in the accidents incidental hole and bend to wash-days the two ends as shown in the illustration. fasten the wires with double-pointed carpet tacks to lock them in position. There should be enough spring in the wire to firmly hold the clothesline, which is slipped between the two curved ends of the clamp.—LEO KOENIG.

82 Draftsmen who believe in neatness — will heartily approve of this rack for brushes and pencils with the grooves running crosswise, thereby preventing the sides from warping. The pencils, brushes, eic., being put along the grooves, cannot roll off, and brushes still wet with color will not smear the table, since they are raised above it. -A. SCHAAL. Learning the Morse Code with a Spark-Coil ROVIDED you have a Ford spark- coil and a battery, you can impro- vise an apparatus that will enable your boy to study the Morse code to his heart’s content. The illustration clearly ex- plains the arrangement and wiring. One of the wires is at- tached to the end contact of the coil and the battery. The other wire is attached to one of the little screws that hold the vibrating plati- num blade. Both wires are attached to the key as shown.—-PAUL J. SCHMIDT.

Your boy will be delighted to learn the Morse code To Transform a Shaper into a Hacksaw AKE a piece of flat stock about 34 in. thick by 1 in. wide and bend it to shape as in the’ Arranged thus, D f drawing. So the hacksaw will there will be do exact work no side play in the _ tool- post, rivet a strip of steel to part A. Bend end B to make a double stock for drilling and tapping for screw C. Use a shaper vise to hold the work to be cut and feed with the vertical handle D.

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ily une, 1921 —~and Tomorrow We'll Il Fish the Flambeau” *T’ve a hunch there’s good fishin’ up in that country, Fat. Up beyond the Reservation, where it ain’t all fished out.” “T’m with you, Sam. We couldn’t get up there last year wasn’t enough road for the car—but with the little old Harley- ’ Davidson we can make it easy.’ “You said something, Fat. It’s not the motorcycle’s fault you never catch any fish. But with your Harley-Davidson and my fishin’ skill we’ve got a combination that’s a darb. | admit it!” Fifty miles for a dollar—gas, oil and tires—is mighty cheap transportation. Ask any TIlarley-Davidson dealer for demonstration. Or write to us for literature. HARLEY-DAVIDSON MOTOR CO., MILWAUKEE, WIS. HiarPley=Davids@n “COorlds Champion”

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Amuse the Children with the Balancing Acrobat

LLUSTRATED here is a toy that performs tricks a real acro- bat is unable to do. It can hang toes, or even by one toe, with the body hanging in space, without support. If the arms are properly adjusted, it will stand on one or both arms angle desired. The figure is carved from one solid piece of wood 3 in. long and 1 in. wide and 34 in. thick. By whittling, this block of wood is fashioned to resemble the form of a human body. At one end a long V-shaped cut is made to form the legs of the acrobat. A pair of arms, also rudely fashioned, are then supplied. They are made of wood }4 in. thick, l¢ in. wide, and 2 in. long. They are drilled at the shoulder end, to fit tightly on a

by its

Showing the differ- ent parts of this amusing toy with the body at any pin connecting them with the body. At the

ends of the arms Here the little man notches are cut is standing erect to support the balancing-pole. The arms are then attached to the body of the toy man. The balancing-pole is provided with two wooden balls about 1 in. in diameter. The pole should be 14 in. thick and 14 in. long. It should have a permanent bend in it, the center of which should be 3 in. from the line passing through its ends. This pole is fastened to the hands of the acrobat by small nails. A pedestal is made from a stick 10 in. long and 1 in. in diameter, with

a 2-in. disk on top and a 5-in. Here he seems to disk at the bot- defy the law of gravity tom. The acro- bat can be placed on top of this pedestal in almost any imaginable position. An Electric Game for the Home Circle HE little spinning pointers used in different types of games can be elec- trically driven as illustrated here. A toy motor drives the pointer. The motor is placed in the way shown in the picture. Directly under it is the dry cell. Mounted at the side is the push-button. To the upright piece that holds the motor and the push-button, the dial is tacked. The shaft of the motor protrudes through the center of the dial and the little pointer may then be soldered to it. If the button is given a push, when the pressure is re- leased, the hand will stop. Its position will always be different, thereby introducing an element of chance. The writer has invented a game shown in the illustration. This is called the Ladder of Success. It merely consists of a card- board strip with slots cut in it. These slots accommodate a penny. The slots are numbered 1 to 25. The players spin the motor and if the pointer stops at 3, one of the pennies is moved up three rungs of the ladder. If the pointer happens to stop on one of the shaded portions of the dial, the corresponding number of rungs or steps is sacrificed. The player who gets to the top of the ladder first, wins..-CARL ROYER.

TOP 25 24 — 23 —— 22 21 —— 20 19

Lo i. > \ 8 10

\Y_- MOTOR

PuSrI- BUTTON

—-nw bono w

V7) ////)/ / 1/7 WA VIMMILLP. /

Popular Science Monti|y How to Make Use of an Old Fountain-Pen OU can use old fountain-pens as pencil- holders. If it is a self-filling pen, take the rubber tubing from the barrel and also remove the part that holds the pen-point. After this is accomplished, take a pivce of pencil about 3 in. long and place it in the Cesena barrel of the pen, leaving about 34 in. projecting from the barrel. This makes a neat-looking pencil and the lead is protected from being bro- ken.—CLEM §S. GREER.

PENCI al » Old fountain-pen tubes may serve as pencil-holders Make a Holder for Hanging Up Your Trousers T is very easy to make this trousers- holder. Take two sticks, preferably 3g in. by 1% in., and about 10 in. long. Three quarters of an inch from each end drill holes of about -in. diameter in each stick, then bore a second set about 3, in. from the first holes. This must be done on both sticks. Then take a stout string, part

This is not intended as a gambling device, but as an amusement for the family circle This Octagonal Barn Has Many Advantages HOWN here is an octagonal barn with a homemade silo in the center. It is planned to accommodate 12 cows and 6 horses. The mow capacity is 50 tons loose hay. The upper story consists of a large haymow and the feeding alley around the silo is wide enough to admit enclosed hay-chutes, straw-chutes, and also for silage, and a place for mixing feeds that may be spouted down from the bins overhead and located around the silo. LITTER ALLEY Y) a | < eo 2) ' te) U N

Octagonal barns are unconventional, but they offer certain advantages as here set forth There is also a granary on the main floor of the barn that will be handy for feeding. This barn can be arranged so as to hold 24 stalls for milch-cows. Hay is placed in the barn by driving the hay-wagon in- side and hoisting hay to the mow with a hay-carrier. 84

a |

\If you use this holder with regularity, your trousers will retain their form much longer of a fishline will do, and pull through the outer holes of the two sticks. Then pull the ends through the second pair of holes and tie a knot large enough so that it will not pull through the hole. This completes the hanger. Take the trousers by the legs, pull the two sticks apart as far as they will go, insert the ends of the legs, and pull the string on the upper stick. This will draw the two pieces together. Hang in the closet on nail or hook.—E. BADE. Brass Shells for the Shade- Roller Ends ITTING the ends of a homemade roller with empty shotgun shells makes them uniform, as well as giving the roller a finished appear- ance. A rough stick first fitted with the cartridge ends can be smoothed down ENO OF SrlOT- GUN SHELL

SCREW- ROLLER uniformly, the TYE ends acting as The brass shells a gage.—JAMES add to the neatness M. KANE. of the roller

June, I Carpe H (ME vitk yond a fe quite as | Procur hard wc the spo sude on i Drive a brad in of the st slip the s the other screw C made of serew screwed i spool. Adjust made by | it reaches ening the It of th the s will e scr tick.- To from S O prey hardw slight ine Pl€ces out an ay Th | fl | | | | itom ese I Wu ——™ \ A ne es wer nm The sucti cup preve How BE pe LOW on Ww copper tul to the len Th thi the for insert havin of mu A lower pen | rubbe to pre

e p S per mos intai ed i £ fir: cilag mal end oun bar ‘vent

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the the ind not the the g0, the raw the le- ade ies i1KeS ler a

June, 1921 Carpenters’ Gages Can Be Made Cheaply H' ‘ME workshops can be_ supplied with a gage that will cost nothing be- yond 2 few minutes’ work, and that will be quit’ as effective as one costing more. Procure a large spool and trim a stick of hard wood till the spool will < Na sude on it easily. Drive a small brad in one end of the stick and slip the spool on the other. A set screw can be made of a small screw =e 976 screwed into the This gage could be im- spool. provised very quickly Adjustment is made by sliding the spool on the stick till it reaches the position desired, then tight- ening the set screw. It will be best to file off the sharp point of the screw-eye to keep it from scarring the stick.—H. F. GRINSTEAD. SCREW- EYE

To Prevent a Stand from Slipping on Hard Wood O prevent the slipping of a stand on a . hardwood floor, and also to adjust slight inequalities in its feet, I cut four Pl€ces out of a section of an inner tube of an automobile. These I tacked tightly to the legs of the stand. The Bae tight tacking bs ae produced a cup- \ ' |-—tack shape forma- Pa tion of the gt loor rubber, the suction of which

Nn i eee esse answered the | } CUP SHAPE purpose better | = AF TER TACKING than anything . a elseI couldhave The suction ofthe rubber used. ——- JAMES cup prevents slipping M. KANE. How to Make Your Own Fountain-Pen ELOW is described the way a fountain- pen was made. A piece of brass or copper tubing 3¢ in. in diameter was cut to the length of 6 in. The upper end of the tube was then closed with acork. Thiscork should be solid and free from holes, to insure against leaking. CORK — A, . SHALLOW

y 3" = A shallow @ BRASS TUBE “6 ' groove was then JSP RUBBER BANDS cut into one side m “ORK of a cork, begin- The principle of ning at the small this pen is that of end and extend- the most expensive ing two thirds of fountain-pen the way down. This’ cork was Inserted in the open end of the tube, having first been coated with a thin layer of mucilage. _ A small hole was bored through the lower end of the tube and a common large Pen bound over it, being held by small tubber bands, firmly, but not close enough | to prevent the flow of ink.

Away From City Cares Get a Togan Cottage; for you and your family to live in this summer. Good looking, well arranged ; built to give you all the rest and comfort of life in the open. Low priced; built complete in our factories. You can do the erecting yourself if you like. Write for catalog ‘Away from City Cares.” It tells you how to get your cottage quickly and economically. ‘TOGRN COTTAGES

=a ==

TOGAN-STILES Grand Rapids Michigan

Also Togan Garages and Bungalows

2 == = = = =» EEE EEEEE EEE ERE EEFESEREESTEEFEEEEEELEEEEEEEEESCES

SS 85 L lh ———- ee ee EEE EREEEEEEE EE SEE EE EE EEE EEE EERE EE EER REE EE REE EEE ee Eee ee ee Pe ee ee ee ee ee avz2a2a7sSsa72 ‘oo 2s32 7272 222 2272 .

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Learn Autos me from failure to success Free $125 Airplane Engine Course To students enrolling in the next thirty Earn More Money, Make 150 to 400 Monthly You can qualify for one of the many well paid growing Auto Truck and Tractor industry this Practica We teach you the practical way—no books or i every part of autos, tors, the kind you will do every day in your own business when you leave us. You do it under the direction of Practical Instructors who know them inside out. Enroll Now . an You Save Money Start as I started—my two | I believe our price is sons and I own this school—I lower than any other got my start at an automobile {S. \ school and we only guaran- school (one of the first in the ) tee it for thirty days. Now country) nearly twenty years j is the time to write us. ago. I was past thirty witha ; You will be astonished wife and family. It turned GJR when you learn of our MOTORS SCHOOL of Auto’s, Tractors and Airplanes 101 Practical School Bld’¢ 117 W. Pearl St., Cincinnati, Ohio days we will give absolutely OHIO §S ST ATE r without extra cost our > ~ $125 Airplane Engire I RACT IC AL Course. All the latest type airplane motors including the famous “Liberty” for you to work on. and lractors positions open in this fast in from six to ten weeks at Motors School. actual work on trucks and trac- great special offer. Send for Catalog You want to see our new catalog. It shows you our. wonderful equipment we have for you to work on. Read in it of the success of other men who have learned by our practi- cal method and who are today earning the big money paid experts or else own businesses of their own. Send for it today. Puta teffeyMotor onYourBicycle | BEST ATTACHMENT MADE LOWEST PRICES. § Converts any bicycle into a motor cycle. In use over 21 years Send stamp for circulars. co., 5025 Brown St., Phila. Pa. Speed Lathe $4 50 STEFFEY MFG. ° Ss, Longer bed 24 in. Metal $1. per Bed additional foot. 3 ‘4in Face Plate $ . pus Center or Head has 8.speed cone, No. 1 Morse Taper Turning Shank Centers, 3-8 in. hole thru spindle. ¢ . Tail Stock has screw feed spindle and No Immediate Morse Taper Shank Center. Also Larger Sizes Delivery CENTRAL MANUFACTURING CO. FAIRFIELD, IOWA You Can Save *50.00 By recovering your old auto top frame yourself. We make these recovers to fit $6 55 all makes and models of cars. o Any person that can drivea car can putiton. We furnish and up instructions, Parcels Post Paid ters sewed together with rear curtain, fasteners, welts and tacks All complete. Give us the name, year and model number of your car and we will send you our catalogue with samples and quote you exact price LIBERTY TOP & TIREJCO. Dept. E8, Cincinnati, O. Mechanical Drawing Instruments Be prosperous and successful—Create your own and inventions. Get one of these splendid outfits of drawing instruments at less than cost. 100 complete sets will be offered only—our chal- lenge offer is ready for you now, Don’t Miss It— write to-day for attractively illustrated particulars—FREE NATIONAL INSTRUMENT COMPANY 4518 North Lawndale Avenue, Chicago, Ill. Roof and quar- ideas MACHINE SHOP WORK A guide to the most improved methods of modern shop practice, including the construction and use of im- proved tools and machines, the use of various hand tools, the lathe and lathe tools, and the methods of screw cutting, taper and eccentric turning, ete. 360 pp. 401 illus. Price, postpaid, $2.60 Popular Science Monthly, 225 W. 39th Street, New York Dollars in Hares We pay $7.00to$1 8.50 and upa pair and express charges. Big Profits. We furnish guaranteed high grade stock and buy all you raise. Use backyard, barn, cellar, attic. Con- tractand Illustrated Catalog Free. STANDARD FOOD AND FUR ASS’N 407C Broadway New York This Interesting Free Book shows how you can become a skilled player of plano or organ in your own home, at one : peweer ele sont. Dr. Quinn’ 8 ‘famous rr n ethod is endorse oy leading nusic jans and heads of State Conservatorie s. Successtul 26 years. Play chords at once and complete piece in every key, within 4 lese —- Setentie vet easy to une Als eng 3 ilistrated. For = or teachers, old or youn music free di loma ranted. Write today for 64-page free book. ‘‘How to Study Music’ r M.L. QUINN CONSERVATORY, Studio PS 26, 598 Columbia Pood. Posten, 25 Mars. Save Or-e-Half Most for the least money inthe latest models of ALL MAKES. Rebuilt by “Young Process.”"" Fully guaranteed. Easy terms. No interest. FREE (RIAL. Satisfaction assured. Write for catalog. YOUNG TYPEWRITER CO., Dept. 103, CHICAGO 950 INSURED GENUINE TOYO PANAMA HA AGENTS FOR MEN AND WOMEN WANTED Unbreakable, Dep. 18, 1431 Broadway, New York 4s Can be folded, put in pocket, silk ribbon and sweat. Sells as high as $5.00. $15.00 per dozen to agents. Send $1.50 for sample; state . PANAMA IMPORT CO. Popular Science Monihly An Adjustable Horse Made of Metal HE all-metal adjustable horse show, j; the illustration was introduced in one of the shipyards on the Atlantic coast to take the place of the wooden horse that had formerly been in use. Although the meta! horse costs a trifle more than a wocden IEAVY IRON BAR RIVCTED FLAT a For heavy work an iron horse like that shown here will be found more lasting than a wooden trestle horse, it lasts a great deal longer, hence meaning considerable saving. It stands 3 ft. high but can be raised to 5 ft. Parts of the trestle braces and cross pieces are made of flat bars of iron. The supporting bar of the horse consists of a heavy iron bar with its ends riveted in t sliding means of pins.—JOHN J. the supports that are adjustable by BORMIDE. Protecting Office Furniture from Injury NOOD office furniture and desks in the home are usually marred by _push- ing the chair underneath the desk, bump- ing the legs, scraping off the finish and chipping pieces of the wood off the —— edges. This can be / avoided by placing a rubber band } in. thick on the chair, as shown in the illustration, with tacks having rubber - covered heads. This pro- tects the desk as well as the chair and will not in any way mar the chair, make it unsightly, or interfere with its usefulness. A thin piece cf sheet rubber doubled over, or a small rubber tube, may be used.- The rubber tects the furniture HH. 2. band pro MENDE. Soften Noise by Using Rubber Stair-Treads LD inner tubes may be utilized to ad vantage for making wooden stairs practically noiseless. The tubes are split open their entire length and. cut int strips 18 in. long and as wide as the cit cumference of the ates tubes. ——— These strips Fron —— are tacked on the steps in the mar- ner shown in the illustration. One side is bent over the edge of the steps and is nailed down with wire These stair-treads are made from old Money refunded if not satis- EZ ¥ 86 inner tubes nails. June, 19 Any | Th ERVI( ( rafts the airec self-« ple that it 1 solid ier up 3 | 6-i The h ¥g-in. str a good s user 10 | To uSi desired s + TTT ce i} es i CLAMP Any one | crease it of the ti by driv’ Mak DI 42 hay He may inch, bi will in THREE= This asca end of shown j It car always 1 this circ of the t kept in To Ri ( HE no t one out A pie cut off the sey same le the old Was no Sary tc new th the sere Tana ta tomake work fr

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nee nds rOss The the by re the ush- imp- and —s

1 pro- re ENUDE. to ad- stairs D split int he cit- F of the strips on the > mar- in the One t over of the : nailed 1 wire

June, 1921

Any Draftsman Can Make This Sandpaper Block ERVICEABLE sandpaper blocks for S draftsmen may be made by following the directions here given. The drawing is self-explanatory, but it should be noted that it is best to make the clamp ring a solid piece. The writer tried first to bend up 3 16-in. wire and met with failure. The handle is to be made of %-in. by 1;-in. strip carbon tool steel and drawn to a good springy temper. This enables the user to employ sandpaper cut 1 in. wide. To use this device, cut a piece of the desired sandpaper 1 in. wide by 8 in. long, SIDE VIEW 4 4} eae cue: sete CLAMP RING TO ga BLADE | os / 3s. SANDPAPER - 2 —_— ‘ S\_

= = P Vi «al iy - , OME. Me 8 CLAMP wn RING\ we \ ee a Any draftsman can make for himself one of these convenient accessories crease it by doubling, slip it over the blade of the tool, and clamp the handle in place by driving the clamp ring over it. Making Work Easier with a Scale-Holder A DRAFTSMAN’S rule is triangular, 4% having six scales, two on each side. He may be using the scale of 50 ft. to the inch, but when he lays down the rule, it will invariably tumble over on another side. When the —CELLULOID 5 draftsman again picks up the scale, he must turn it over, looking at the scales till the 50- ft. one is found. THREE-CORNERED SCALE This annoy- This disk will keep ance may be a scale from turning overcome by placing at each end of the scale a piece of celluloid as shown in the illustration. It can be readily seen that the scale will always roll over on the flat side. By placing this cireular piece of celluloid on any one of the three sides, the desired scale can be kept in sight.—E. G. GETTINS.

To Repair the Broken Screw of a Meat-Grinder T# Kk family meat-grinder giving out and no thumbscrew being handy, I made one out of an old wringer clamp. A piece of the threaded end had to be cut off to make the screw the coast Same length as ie the old one. It Was not neces- WRINGER sary to eut a CLAMP new thread on 2 the screw, but IT S***=*=>" Tanatapinsoas = ~~~~~~ tomake thescrew work freely.

An emergency meat- grinder repair

ws

, AX WM Oy

SAFETY RAZOR —as simple as that! Safe and sanitary. Pleases instantly, and so thoroughly that its satisfied users everywhere are its best salesmen. Proof :—2,000,000 in regular use before it was ever advertised! “Just like wiping your face with a towel”’ Wa Gndeors ENDERS SALES COMPANY 17 Battery Place, New York ENDERS SELLS FOR $1.00 with six blades of the best quality Swedish-base steel, hand-stropped and hand- tested. Packed in black Keratol box, velvet lined. Extra blades, package of 5—35 cents. In CANADA— Razor, $1.50: Blades, 50c.

FOR SALE BY BEST DEALERS EVERYWHERE

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popular. on the ballroom floor. scientific home instruction. with correctness and grace. \ny number of people, a whole family, can learn from one set of Arthur Murray's cleat and simple instructions with the Moviescope. Get all the folks in and make it fun and pleasure while you learn. All the latest steps right from Mr. Murray’s New York Studio. Every step worked out in pictures every count shown—every position illus- trated in graphic illustrations and motion pictures in the Moviescope. No gaping Courtesy of Sctence and Invention for April) —

© A. Murray -ms pleased with the i of moving pictures achine, { the latest steps Some istration sec ce by the al and looks « nstration oO The boy in out illt idea of learning to — As he turns the crank, al demo ca he sees an actus d by Arthur Murray. The idea was ig ee carried an article — Forbes wee vray has the largest cone ~ a vnd_ earned $15,000 a year w world at s

ine time ago stated that class in the going to college forty-two small leaves As the crank 1s tare the rapid apron ne $ barre ino step is producec BevoIve —, action of a Gane ear the jearnet can g leaves ts . rane > < falling lea ted by -ment at any ing opera : The machine being OT nd stop the move Dont Be A Wallflower! Be a good dancer and always be welcome and Delightful, lasting friendships are made Dancing is a great social asset—fine recreation, an excellent health builder. Thousands of men, women and children are learn- ing the art of fine dancing in their own homes with the wonderful Arthur Murray Movie System of easy, Prepared by the coun- try s greatest and most successful dance instructor. This Arthur Murray Movie Method is so simple and complete that any child .can learn. to dance Learn To Dance at Home

he machine for five min- » pleases a rn as fast as he p ‘min th than one hundred times t time By looking down into

utes, the step 1s repeated mor

crowds to embarass you. You SEE what you should do and you repeat the picture over and over to your heart's content. Best of all you learn to be a fine dancer at a frac- tion of the cost a dancing class or private teacher would charge. Send No Money Don't take our word. Send no money. Simply send the coupon and we will send the Complete Course. including a Moviescope FREE, at once. You pay the postman only $4.45 plus postage. The Course includes complete instruction in all the steps—Fox Trot, One Step, Waltz, Toddle, Two Step, College Rock. If not delighted, return the lessons within 5 days and your money will be refunded at once. Moviescope Free Here's a special offer, good for only a limited time With each set of instructions at only $4.45 we include a Moviescope free. The Moviescope is the new invention that is revolutionizing the teaching of dancing. With the Moviescope you see each step 70 times each three minutes through this hand-operated picture machine It makes each step amazingly clear and simple. Each step repeats itself until it becomes firmly fixed in your mind. You keep on looking until you learn the step Remember, we send the Moviescope absolutely free with every set of instructions at only $4.45. Send no money now. Send the coupon. ARTHUR MURRAY SYSTEM OF DANCING Dept. 46, 290 Broadway, New York

Arthur Murray System of Dancing Dept. 46, 290 Broadway, New York Please send me the complete Arthur Murray Dancing Course, including the Moviescope, which is to be sent free. I will pay the postman $2.95 plus postage for the complete Course, with no charge for the Moviescope. If | am not completely satisfied I will return the Course within five days and you are to refund my money. PIGMC... 2. Address ee ae

Vol. 89, July-December 1916; January-June 1919.

Vol. 92, January-June 1918; Vol. BOUND VOLUMES of Popular Science Monthly The most interesting and valuable book vou can obtain is a bound volume of Popular Science Monthly. history of the World’s progress in picture and text. volume contains over 2,000 pictures, over 1500 new arti- cles, handsomely printed in a big book of 960 pages. It isa Each Volumes are now ready as follows:—Vol. 88, January-June 1916; Vol. 91, July-December 1917; 93, July-December 1918; Vol. 94, Price per bound volume, postpaid, $2.50 Popular Science Monthly, 225 W. 39th St., New York

Popular Science Moniti|y Here Is One Way to Lock Hexagonal Nuts UICK and easy is the method ‘o, providing locking means for hexagon! nuts shown in the accompanying illustra- tion. The job was done on the gear-box of an automobile. The plugs for the shift ng

oe | Kev Ys 7 i arise PT i | This illustrates one method of locking two hexagonal nuts, provided they are separated by a short distance only

forks were neld by means of lock- washers: and these washers, pressing against the soft aluminum case, caused the latter to be severely torn and damaged. I finally con- cluded that the plugs must be held by some means other than the lock washers. A piece of !4in. by ) in. strip steel was made red hot, and was hammered to the shape indicated, one of the plugs being used as a die while the forging was done. Two head- less set screws served to hold the lock in position..—ADOLPH KLEIN. The Phonograph Stops at the End of a Record fou bringing a phonograph record to a standstill when a piece has been played, a new device is here described. The device consists of a trigger against which the tone

When the record is finished the brake automatically stops the phonograph arm presses when it has run its course. This releases a spring, which pushes a small brake-shoe against the rotating record table. Old Tire Rubber Gives Grip to the Brake HE grip of the wagon brake on the wheel may be greatly strengthened by covering the brake surface of the shoe witha piece of old rubber tire fast- ened to the wood with wooden I screws. The width of the strip de- pends on the %© width of the | wheel tire. An | allowanceshould | - be madeforalap VP ae a of 1 in. through ok" THICK which the screws 2 pass. — W. H. Nail a piece of old ti: GILES. on the brake-shoe OLD TIRE 1" OVERLAP BOTH SiDC5

oO

be

bli dey are th ani wil sla are

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oft be on- by ade ape iS a -ad- K in

h 1rse. mall ( ord rip the ened shoe a) in

June, 1921 Trunks May. Safely Be Dropped on This Mat LD tires, too worn to be used on an automobile, will supply excellent material for making a baggage mat such as is used at the railway stations to prcetect baggage from injury when it is dropped on the platform from cars or trucks. The mat 1s of circular form. One tire, left complete, forms the outer circle. The inner circle is made from part of another tire. smashers mat like this

Defy baggage- with a What is left of the rubber fabric is cut in pieces to form the connecting spokes. The two rubber circles and cross pieces are bolted together as shown in the illus- tration. The bolts are so placed that the nuts point toward the center. The heads of the bolts are provided with bent washers so that they be flush on the outer rim. How a Mouse-Frap Became an Office Accessory ROM the spring of an old mouse-trap and a bit of wire the cashier of a Western bank improvised a clip for holding flat the checks and bills in the cash drawer. The wire was bent as shown in the picture with a mouse-trap spring around one of the TIFF WIRE £ iL.

The spring presses down the wire loop short sides of the rectangle. Two small staples fastened the con- trivance on one side of the cash- drawer compart- ment as shown at the left. The holder or clip could be raised easily when it became necessary to add more checks to the pile.—L. M PRIGHAM. A Drying-Rack for Your Photographic Plates MAN Y a good negative has been broken when left to dry leaning against the wall, because it was knocked down. A perfectly serviceable drying-rack can be made from a block of wood or a piece of heavy board in the manner shown in the illustration. Parallel grooves ' of approximately | the thickness of the glass plates are sawed into the wide part of the board or block: to the depth of about in. The plates are placed in these grooves and left standing with a slight slant until they are dry.

In a pinch this - plate-rack will ren- der good service W. L. DOUGLAS ‘8.00 SHOES Special Shoes $10.00 ! Retail Price Reduced Hand Workmanship FOR MEN AND WOMEN THE STAMPED PRICE IS W. L. DOUGLAS PERSONAL GUARANTEE

Quality of Material and Workmanship Maintained Special Shoes $6 (}()

YOU CAN ALWAYS SAVE MONEY BY WEARING | W. LDOUGLAS SHOES | SOLD DIRECT FROM FACTORY } Ld You AT ONE PROFIT THAT THE SHOES ARE ALWAYS WORTH THE PRICE PAID FOR THEM | They are the best known shoes in the world. Sold in 107 W.L.Douglas stores, direct from the factory to you at only one profit, which guarantees to you the best shoes that can be produced, at the lowest possible cost. W.L.Douglas name |

THE FINEST SHOES IN THE WORLD ARE MADE IN AMERICA. ....- W.L.DOUGLAS SHOES ARE LEADERS IN STYLE FIT- WEAR-AND COMFORT

and the retail price are stamped on the bottom of all shoes before they leave the factory, which is your protection against unreasonable profits. W. L. Douglas shoes are absolutely the /.38°°. } WN best shoe values for the money in this — country.They aremadeofthe bestand _ ; a finest leathers that money can buy. (... They combine quality, style, work- fo. rome we wearing qualities equal “i to other makes selling at higher prices. id They are the leaders inthe fashion #450 £4500 centers of America. The prices are the same everywhere; they cost no more in San Francisco than they do in NewYork. W. L. Douglas shoes are made by the highest paid, skilled shoemakers, under the direction and supervision of experienced men, all working with an honest deter- mination to make the best shoes for the price that

money can buy. © A U T : oO Insist upon having W. L. Douglas shoes. The name and price is plainly stamped on the sole. Be careful to see that it has not been = js or mutilated. MiloO nt y, W. L. Douglas Shoe Co., 724 Spark St., Brockton, Mass. W. L. Douglas shoes are for sale by over 9000 shoe dealers besides our own stores, If your local dealer cannot supply you, take no other make. Order direct from the factory. Send for booklet telling how to order shoes by mail, postage free.

OU can earn from $1 to $2 an hour in your spare time writing show cards. Quickly method. you how, each week. and easily learned by our new simple No canvassing or soliciting, we teach sell your work c Full particulars and booklet free. AMERICAN SHOW CARD SCHOOL 206 Ryrie Building, Yonge & Shuter Streets, Toronto, Canada and pay

ORDER YOUR GUN NOW FOR NEXT MADE TO ORDER FOR YOU SEASON IT COSTS NO MORE.

LOOK INTO THIS! Any gauge, length, weig ont; Peo me CE or particulars Our Specialty SPAaers» 117 East Fourth Street, Cinci ti, Ohio = The Rudolph Wurlitzer Co. 3298S. Wabash Av., Chicago; 120 W. 42nd St., NewYork : Send me your new catalog illustrated in color with details of Wurlitzer Complete Outfits, free trial and easy payment offer. DN pasa wervasedtucvesddeccdvceasencoectctos evvccccces Address.

a eee meee ewes nese eee § Tete eee eee eeeeeeeeeeeeese

Page 74

‘Canadian TRUNK) National "System Y CANADA Calls You! Vacation -Land of Ideal Summer Clirate Hay fever is unknown in this clear, pine-and-balsam scented air. Unlimited territory to choose from—cloud tipped mountains and rugged foot hills inviting exploration; wide valleys of woods and streams and wild flowers; turquoise lakes with sandy beaches; the restful relaxation of camp life or the luxury of the finest hotels. In Canada, your Ideal Vacation is senlined: Al- gonquin Park — 5 pee a Lakes— Great Lakes Cruise—Geor gian Bay—lI ake of Bays—Kawar- tha Lakes— Timagami— Nipigon — Cuetico— Minaki— Lower St. Lawrence and Maritime Provinces. Fishing, boating, bathing, golf. A summer play-ground in the gre at out-of-doors. jasper Park, Alberta, and Mount Robson Park, Rritish Columbia, embrace the scenic mountain wonders of the Dominion. For full information write Canadian National or Grand Trunk Railways at any of the following addresses—Ask for Booklet E, mentioning districts that interest you. Boston, 294 Washington St. Buffalo, 1019 Chamber of Commerce Bldg. Chicago, 64 West Adams St. Cincinnati, 406 Traction Bldg. Detroit, 527 Majestic Bidg. Kansas City, 710 Railway Exchange Bldg Minneapolis, 518 Second t. Ave., South Seattle, 902 Second Ave. Fishing, Hunting and Camping Real fishing and hunting in virgin streams and unspoiled big game country in NOVA SCOTIA, NEW BRUNSWICK, QUEBEC, ONTARIO, ALBERTA and BRITISH COLUMBIA. For full information write G. T. Bell, Passenger Traf- fic Manager, Grand Trunk Railway System, Montreal, or H. H. Melanson. Passenger Traffic Manager, Canadian National Railways, Toronto. New York, 1270 Broadway Pittsburg, 505 Park Bidg. St. Louis, 305 Merchants Laclede Bldg. ae Cor. 4th and Jackson ot. ~~ Francisco, 689 Market aS “Reo” Cluster Metal Shingles, V-Crimp, Corru- gated, Standing Seam, Painted or Galvanized Roof- ings, Sidings, Wall lboard, Paints, etc., direct to you at Rock-Bottom Factory Prices. Positively greatest offer ever made. Edwards ‘“‘Reo” Metal Shingles cost less; outlast three ordinary roofs. No paintin orrepairs. Guaranteed rot, fire, rust, lightning proof. Free Roofing Book Get our wonderfully low prices and free samples. We sell direct to you and save you ail in-between dealer’s ag Ask for Book a. 198. : ——— LOW PRICED GARAGES Lowest prices on Ready-Made Fire-Proof Steel Garages. Set upany place. Send postal for arage Book, showing styles. THE ENWARDS MFG. Co., 648-698 Pike St., Cincinnati, 0. A Safety Razor and a Clip Make a Hair-Cutter ITH a pocket comb, a safety-razor blade, and an ordinary paper-snap, which can be purchased in any 5-and-10- cent store, a practical safety razor and hair-cutter can be easily contrived. To be used as a razor, lay the blade on the comb, so that the edge of the blade pro- jectsslightly over PAPE the edge of the FASTENER = comb, then make it stationary by clamping on the paper-snap. For cutting hair, place the blade _ slightly behind the edge of the comb, and clamp in place with the paper- snap. The blade may be adjusted to cut the hair long or short,aceording tothe taste of the individual. To cut the hair, operate this device as you would an ordinary comb, using two mirrors to insure accuracy and uniformity. To get the best results, wet the hair before using the cutter.—LEo D. THREW. A comB/ For a haircut the razor blade should be placed as shown here RAZOR BLADE J Keep Golf-Sticks Dry in a Rubber Bag ROM a few feet of inner tubing in fairly good condition a golf-bag may be made which, better than a canvas or leather bag, will keep the clubs dry in any kind of weather. The bottom of the bag may be made by ce- menting around piece of rubber to the inner tube, which should be folded over the insert- ed bottom, and cemented to it. Instead of ce- ment, rivets {may be used. Tostiffen the bag and hold it inshape,leather straps should be cemented or riveted on the outside, as shown in the illustration. A separate container for golf- balls may be cemented to the bag and straps for carrying the bag attached by rivets.—C. A. BLACK, JR. LEATHER } STRAPS CEMENTED This golf-bag will keep your clubs from warping Ether Is Useful for Cleaning Clothing THER is very useful fcr removing grease spots from clothing and other textiles. For a long time it has been used in cotton and woolen mills for removing spots from new cloth. Ether can be purchased in drug-stores in half-pound cans. It is not expensive, but is very volatile. After taking the re- quired amount from the can, the container must be tightly closed as soon as possible. Ether is inflammable and should not be used anywhere near an open flame or open fire, nor in a closed room where the ventila- tion is not good. The same care should be exercised in its use as in the use of gasoline, benzine, and like products. 90 Popular Science Monthly (None genuine without this trademark) & True-Tone Saxophone A Buescher True-Tone Saxo; ame opens the way for you to great crease your income, opportunities, popularity and pleasure. Easiest of ail wind instruments to play . Ae —you can learn toplay thescale (aay in an hour and in a few days {4 be be playing popular airs. Prac- tice is @ pleasure. Tells you when to use Saxophone Book Free 32!5c0,hen.tonse in mee ony or in regular band; how to transpose cello parts in orchestra and many other things you would like to know. 3 Tri You can order any Buescher instrument ree and try it six days without obligation. If perfectly satisfied, pay for it on easy payments to suit your convenience. Mention the instrument interested in and . complete catalog will be mailed free. BUESCHER BAND INSTRUMENT co. Makers of Everything in Band and Orchestra Instruments 3126 Buescher Block, Elkhart, Indiana BE YOuR OWN BOSS. MAKE MORE MONEY With little capital, you can establish a business in your own home town ee make $10 to $30 per day with Anderson's Steam Vulcanizers. tter work, less cost and bigger profits. There are Anderson schools in 34 states, one is near you, Better schooling plus finest equipment makes Anderson tireologists successful. We teach on the famous An- derson met of vulcanizing and the operation of the An- derson Super-Heated Steam Vulcanizer and Retreader. Takes 5 to 10 days in school and costs . If at any time ou buy an Anderson Vulcan- zer, we refund your $45 and pay you $5 per day for each of the 10 school days, wecauas we sell the work you We will tell you now to make money. Write today. ANDERSON STEAM VULCANIZER CO. 101 Williams Bldg. Indianapolis, Ind. “DON'T SHOUT” “T hear you. Ican hear now as wellasanybody. ‘How?’ With THE MORLEY PHONE. I'vea pair in my ears now, but they are invisible. I would not know I had them in, myself, only that I hear all right."’ The Morley Phone for the DEAF is to the ears what glasses are to the eyes Invisible, comfortable, weightless and harmless Apyone can adjust it. Over one hundred thousand sold. Write for booklet and testimonials. THE MORLEY CO., Dept. 797, 26 South 15th Street, Philadelphia. New Big No. 15-225 pp. Wireless Catalog Wirele ss catalog mailed for 12c in stamps or coin. Any wireless amateur will tell you it isthe one catalogue to have. Asan ency- clopedia of information it is in- valuable. Thelargest and most elaborate radio catalog pub- lished. Values that cannot be duplicated elsewhere. THE WILLIAM B. DUCK COMPANY 224-228 Superior St. TOLEDO, OHIO CATALOG NON The Wiliam B. Duck Co Electrical and Mechanical Engineers receive fabu- lous salaries. Thousands wanted. 3 months to 2 years. Practical-Technical training under experts. Not a trade school but a Practical-Technical College teaching electricity, steam, gas, auto-electric, armature winding, drafting. Extensive laboratory and shop equipment. weston awarded. Day and night sessions. Enroll any time. Don’t judve us by size of ad. Write for free catalog. FINLAY ENGI EERING COLLEGE, 1002 Indiana Ave., Kansas City, Mo ae FOR BUSINESS and PLEASURE Independent Economical Transportation Write for Catalog ‘*B” Clevela nd LIGHTWEIGHT acevete Leal THE CLEVELAND MOTORCYCLECO. CLEVELAND. USA June, GED DIA Gua Engage Wedd Gifts June Gradua Send For There satisfiec urchas alance ly paym LC THE | Dept. on a sma pairing b day.’” capital n sible cust oir Improv Set Does as Priced w can use ji that has / ean’t und Requires Don’t del: ‘ 2105 Four ARPE and ers, Pip and ho you ho will ir Catalo means B E Drafts 7 Colun Make $ Soft D wanted drinks games, onade, others, 80 glass any tin Pure FE W oods two da: soft dr sellers.

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June, 1921 How to Give Your Pulley a Better Grip HOULD your belt slip on the pulley, you can remedy the trouble easily if DIAMONDS WAICHES Creprt you have an old automobile tire avail- We Mtl 7 Ul 7 Wily able. Z The side walls of old tires are usually in good condition. If you cut them out of the casing and fit them around the pulley, it will save you a great deal of trouble and loss of power. Cut the strips of side walls

BELT

Good Pay for You in Auto Business NE DIAMONDS LY

Lady Louise ding Ri i ; : lis “Gite for the geval X so that they will Hundreds ot June Bride, The fine britliant .

good jobs paying

y i Graduation Gifts # Diamond is set in Solid \\ fit exactly around 7 ve Send Catalog White Gold. No.424 isa \}) ; Y around $50 a week For a rare bargain, at oY: the pulley. Apply There are 128 illustrated pages of Dia- mond Rings, La Vallieres, Pearl Beads, Cuff Links, Watches, Wrist Watches, etc. Every article $50 $10 Down ‘a\\3 PULLLY RUBBER some glue to the $5 a Month |i The rubber will give fabric under the Also bargains at $75 to $500 the pulley a firmer rubber, also to the 2 ee oe grip on the belt circumference of 14-k Green Gold, hand- the wheel, and are open for Swee- ney trained men. Garages, repail shops, welding o1 vulcanizing shops, carved. Sent on ap- automobile agen-

area! value, proval, charges pre- ;. sac te ; sicecnadaniedl \ " paid. Cased ina hand. fasten the ends together by clips or by a cies, ete., have : lect will be sent pre- i some Ring box, y : eee ‘ i sete written to the pald. You see and ex. \\ regular belt lacing._- DANIEL COPENHAVER. . amine the article right \ ay Creait at Cash E.J.SWEENEY Sweeney School snlated pay onechifth of \ WR Prices = king for compe por hase price and keep 1 tn San i etores PRESIDENT “ . 1g ° compe alance In eight equal month- Ny i n Lea ° © ent mechanics, ly payments. Liberty Bonds Accepted ing Cities A Grindstone Crank with The Sweeney Schoo! at Kansas City LOFTIS BROS. & CO. Pullev Drive is the world’s largest and most famous — OLD RELIABLE CRED.7 JEWELERS y auto and tractor school. It trains men ; CRANK handle fitted to the pulley in eight weeks by the Sweeney System : : - : -ractic: “xperience. This system 4% furnished with a belt-driven grind- of Practical Experience. This syste ’ under Mr. Sweeney's direction turned stone has proved very successful. The ea : out over 5,000 army mechanics during MAKE MONE Don’t be stone had been sent to a place having no the war. Many thousands of Sweeney content to trained men hold responsible and profit lod alon sin ides ee eee on a small salary, Be independent. Go in the tire re E [a p 2) pairing business. One man says ‘‘I made $60.00 the first day.’ Others average $200 to $600 a month. Very little capital needed, Jobs plentiful, a motorist a pos- sible customer, No experienee need We teach you. SHALER Tire mopair Guttit Improved Wrapped Tread Method Used by Tire Manufacturers Does as good wor's as the big high priced vulcanizing outfits. A boy can use it. It’s the only AR wd that has Automatic Heat Control, and can't undereure or overcure a tire.

able positions in the automobile business. | || TOP VIEW }| | An interesting feature of this training wa BOLTS ~!l_ | is that no previous experience is required. a onan No books are used and evervthing is taught by working with your own hands It is so simple-that.a deaf and dumb man learned to be a good mechanic in eight weeks. The Sweeney School publishes a great number of applications from garages,

air s tc., asking for men. “‘] Requires no watching or regulating. repair shops, etc., asking a) FREE 33 k 4 want a head mechanic and will pay $50 00 Ti you cannot belt your grindstone to a week’’ writes one concern. ‘‘Want “How to Open a Tire Repair Shop.”” a drivesha*’: nulle m i . i, ae, eee — SS It tells how to make big money. icoerseig seoasgi de turn it by hand two mec hanic S. Pay 60 cents an hour. Don't delay. Write quick. powe: with this crank Please wire.”’ writes another. C. A. SHALER CO. 2105 Fourth St. Waupun, Wisconsin available power. Instead of making an LEARN IN 8 WEEKS entirely new crank, a round wooden handle aa SWEENEY SYSTEM was sawed and bolted to the pulley

j Mr. Sweeney publishes a beautifully illus — trated 72?-page catalog that tells all about The two bolts hold the handle firmly in eo egg i pordeig tm ie ' auto _— Meg tor its ace ¢ : , OE business e will send this free without any its place and thus prevent any accidental obligation, together with the Sweeney News, an splitting. R. C. HItcHcock. interesting paper and full information about the demand for trained men This literature plainly shows how any young man mechanically U Pi Wh S Id - inclined who is willing to work hard for a few ARPENTERS, Shipfitters, Bricklayers, Structural, Conerete se Ins en Oo erin weeks can fit himself not only for a job, but for C and Sheet Metal Workers, Electricians, Mechanics, Plumb- x real success in life as owner of his ow . busine - ers, Pipefitters, Boilermakers —can you read Blue Prints . There are many opportunities in both city anc and hold a big job? If not, learn how. It will help Holes in Sheet Metal rural districts. Simply send name today for a your job—it will get youa age ogres free catalog to E. J. SWEENEY, President, will increase your earning capacit rite for . : . Sweeney Schoo < ‘ ran é ) Catalog B, “oling trade. DON'T DELAY—it N soldering a sheet-iron boiler, I found Sweeney School, Auto, Tractor and Aviation, Dept. 877, Kansas City, Mo. means more money! BE A DRAFTSMAN that the pit holes (or rust holes) would not let the solder run over them. As I did Earn $35-$150 Week . ‘niall edie ohee Drfiemaeane deena Meaeanil tools FREE, not want to insert a patch, I inserted pins Write for Catalog G. DO IT TOD Columbia Correspondence School “Fst. 1904 BRASS PINS. SHCET METAL Carroll Dept. Drexe! Bldg., Phila, Pa. — 4

‘ — Fo Brass pins - oa ae wae inserted in | | e s Oy, eer Se -—— FIG ae ; Pe: % wash-boiler -—SOLDER Pr he, ie made the & Uf 1 f Vad Ais Son soldering | n 4 y Uy sosienscsaeAidhedill eo ELT Make $8 to $12 a day this summer. Sell Concentrated FIG.2 Soft Drinks—Non-Alcobolic. Enormous demand— is For Big Free Catalog Mail This Coupon wanted everywhere. Delicious, refreshing summer S 2 RE RANE ct “ ae ong Ee, ao: weap lease egy in the holes—first cleaning the surface of grog: SW poh a Ss, e very popular drin rangeade, Lem- one S S : ace ept. 877, Sweeney Building onade, W ee sien “kc memenr appear say | the metal Rn i ps 7 as aE A eS ° - . ease senc ee y ho ny o I + assee—lose than 1 cent a glass. Always ready— Then I applied solder flux and put a bit my part your 72-page catalog and your Sweeney Pure Food Laws. AGENTS SOINING MONEY of solder over each pinhead, lifting the iron School News. Tell me of the opportunities in oods made $16 first day; Quinn took 115 orders in ‘ the Auto and Tractor Business. two days. Over 100% profit. Sell to soda fountains, so that a little mount of solder was formed soft drink stands, stores, etc. 250 other hot weather h vi head N soing tect. Gonstints Cutt or "Eancl” Prods toc over each pinhead. Name oing fas mplete Outfit of “Zano!l” Products fur- * " . . ni aos aamene case free. Just a postal today—now. The points were clipped off and filed a eee TY: Ce American Products Co. 5313 Amer. B Bldg. Cincinnati, Oh'o flush.—JAMES M. KANE.

91

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A Fascinating Big-Pay Field That You Can Put Your Heart Into No matter whether you wish to visit every nook and corner of the world or whether you have no desire to travel—here is a fascinating field that Both on land and on sea these splendid opportunities are calling And now, through a wonderful new inven- tion, you can quickly and easily learn Wireless at home in your spare time and become a licensed A fascinating big-pay field that you can put your heart into is eargly awaiting your Read how you can step into the won- offers you big pay in either case. you. operator, services, derful future it holds for you. Wonderful New Invention Makes W r From every bran: iess comes the call for opera- tors! From the om call of the U S. Merchant Marine, operatin s vessels that ply over every ocean Private s nes whose ships reach India, Norway, Africa and sn every part of the world also sound the call Big opportunities are offered, with the chance to see the whole world, as an officer with luxurious quarters and good pay. From the land too, comes the call of the new forces that have formed to make wireless the greatest means of com- munication in existence. The Radio Corporation of Amer- ica, with $20,000,000 capital, 1s establishing land stations in every section. The Indepe ndent Wireless Tele graph Co. is carrying out tremendous expansion Business House Ss, Railroads, Police Depts., Newspaper Publishers, Com mercial Clubs, Banks, Agricultural Stations, Civil Service in every field Wireless is being adopted as an essential de- partment of the business. And now as never before is your big life-time opportunity to get in on the wonderful future this fascinating field holds for you. Cash in on the World’s Expansion If you have kept pace with the world you know why Wireless offers you a future which nothing else can. You know that this amazing field has only taken one step com- pared to the enormous strides that are yet to come To-day Wireless is building itself into one of the most gigantic forces ver known. You can cash in on this expansion. You can now easily and quickly qualify for the splendid inducements The National Radio Institute is today the oldest and largest wireless school in America teaching wireless by mail. This Institute is officially recognized by the U. S. Depart- ment of Commerce, its diploma is given official credit, its name heads the list of schools recommended by the Shipping Board And through a wonderful new invention patented by its President, the National Radio Institute will qualify you for a fine Wireless position in a short period during your spare time. “Yess Amazingly Easy to Learn ° ° Special Opportunity Now Open Through this remarkable patented invention, the Na- trometer (given, without extra cost, to each student), and our interesting home-study course the National Radio Institute makes it easy for anyone to learn Wireless at home; no matter whether you know a thing about it or about electricity at the present time. The u- gent need for operators and the calls which come to us for our students prompt us to make a special offer open to new students for a limited time. Through this special offer your enrollment will be accepted at a special rate and you will receive without extra cost our new course in Wire- less Telephony Let us tell you how you can travel all over.the world with easy work and good pay. Or, if you wish, you can accept one of the big wireless positions on land which are now urgently in need of your services. Mail Coupon for FREE BOOK It costs you nothing to get our interesting illustrated booklet, ‘Wireless, the »portunity of Today.’ Mail coupon today for this ws 0 and for full facts about our special Short: Time Offer. Fill out coupon now-—-then mail it today! National Radio Institute, Dept. 86, Washington, D. C f°~ 7" RUSH THIS SPECIAL COUPON *"""" National Radio Institute, Dept. 86, Washington, D. C. Send me your FREE book, ‘‘Wireless, the Opportunity of Today.’ Tell me about your Home Study Course in Wireless Telegraphy and your special Short-Time offer. Address City 1 I i , Name | t i] . State.. U Only $45.00 For This Job Saainenee Save exorbitant freight rates and one-ha original cost by buying Ford @ Speedster Bodies knock ed down. Sim- ple, complete instructions fur- nished, all parts cut to exact fit. Any one can assemble this job. © omplete with hood, radiator chat. instrument board, eee sa es tal parts, wood parts, bolt screws, ete. Flat radiator shell Bee a made up Designed low with lack of wind tesistance. Price set up $90, further particulars on request. The Central Auto Supply Co. Eng. Dept. 122 Louisville, Ky. ie Not Paper Patterns All Parts Complet “Success in Music How To Win It” LET Sousa, ie tr and eight other world-famous musi- cians tell you secrets of their success; how to discover and cultivate your musical “*bump”’; double your income and pleasure playing in band or orchestra. FREE TRIAL Any Instrument Conn instruments are used by world-famous artists. Known every- where as easiest of all to play. Try any instrument No. obligation; y easy payments when you buy. Send coupon for free book and details of free trial plan. 632 Conn Bldg Elkhart, Ind. Agencies in all large cities os ot Oe oe i oe c G. Conn, Led. 632 Conn Bldg , Elkhart, Indiana. Gentlemen:—Please send me ‘‘Suc details of your free trial plan. Name— Street or Rural Re ute City, State "and (Mention instrument. cess in Music County— Instrument —~ KEROSENE ENGINES OTTAWA LATEST DESIG Durable, Powerful, Reliable, Mas- sive. Built to last; to do hard, heavy work. Uses Cheapest Fuel. Pull \ to 4 horse-power more than rated. Lowest Prices. 3 Months Trial. Eas Sizes 14% to 22 H-P. Easy to start. No cranking. No batteries. 10 Year Guarantee. Most practical engine ever built. Engine k free. A postal brings it. THE a ne MANUFACTURING co. 1951 King St TTAWA, KANSAS ngmen RICH! Chas. Evans, carpenter, on 60, now MAKING $1 week in shop wn here. Gibbard of Mich. age 62, learned IRE SURGERY, has shop in small town, a ee receipts for May, June and July, 1920, $3 $30,000 “ “? is easy to learn. I will teach you in two weeks, Within thirty da on road to oes Car d this NEW capes meth- ° t res. million tires wear- {ng down Ls a 9 E wer: AND MORE Tire Sur- sho; bad AN can succeed UICKL ie * a SHORE KAS ¥ atep Into automo- ile industry — id that b le men rich. It doin 4S A, Ay W. Blair, Ohio, . 12 : ~ 4 -00 for — ng, of New Zea- . within { year; and h: done same for vondred ds of. others, There’s money In thie business for YOU, Investigate! Get de- tails, Send coupon at once for the FREE book, 1276 Eavnal — whee nd. ar Ze full details of Tire ,asl to get into big paying business quickly. seal Name Address. Popular Science Mont) y Expanding Lead Plug for a Casting Hole SMALL hole in a casting, as a sand hole, can be readily closed with a piece of lead the size of a shot, calked in with a blunt-nosed tool. A larger hole, Vg in. or more, requires a plug of such size that a_ successful ealking job is not practical. In the event that the cast- ing will stand threading, a tapped plug is correct and makes a serviceable repair. ra 8) i : The lead _ bushing A _thin casting, plugs the hole in especially of cast the casting iron, cannot be tapped for a dependable thread. A repair under these circumstances is made wit! a round lead plug and a small screw-bolt. Drill a hole through the plug smaller than the screw-bolt and drive this in. Then drive the plug in the hole after truing it up somewhat; with a drill set a washer over the screw and put on the nut. The nut can be screwed as tight as required; expand the lead and pack it solidly about the hole.—G. A. LUERS. Bottle-Caps as a Back-Door Foot-Scraper ERE is a scraper that will take off the worst mud from shoes. It can be made at home from bottle-caps. These metal bottle-caps, with which so many of our bottles are closed, are saved until a number of them have been col- lected. Then a 14-in. board of any convenient length and width is taken and two strips of narrow wood are screwed on each end to prevent warping. The bottle-caps are nailed to this base, using two nails for each cap. A neat appearance is given to the scraper if the caps are nailed in parallel rows. This scraper is cleaned by simply jarring the dirt loose. Discarded bottle-caps made this foot-scraper Prevent Your Saw from Slipping Away tere palaaagng when a carpenter’s saw is laid upon a roof of considerable pitch, it has a tendency to slide off. This can be prevented by a simple means shown in the illustration. Bore a hole in the saw handle and drive a long wire nail through it of slightly larger diameter. It should project at least an inch on each side. Then the head should be cut off and both ends of the nail filed down to a sharp point. No matter which side of the saw is laid down on the roof, one end or the other of the nail will stick to the shingles and pre- vent the saw from slipping.— L. B. RoBBINs. we - vi a a - Z \ a was ie A nail will prevent the saw from slipping ae ee June, . A ¢ S OR who their h making Pers han¢ be n combin the libr The shown the de necessa diagran The « amateu select si ing wit room. may be Ath mea you the ap) drawer table n found « randun table Do | VI fro old wic three ¢ Use inst tongs Popular Science Month, June,

Page 77

= June, 1921 1 A Combination Table of Simple Construction ———\ \ " is C= : ux | eX Inf il a a i. pA | A: oe I i em Sh me: ee sit (*( | a "sf i 1% 5 : ] oi cE. tm is a. Lh | i / & ae | re | —k ‘ “paar: 7 oth Med wens tA: The Scientific Way to W ARNER’S EAE eth Bd K * 'T (Oia ‘ pry eno PS 9] : o9 Hang Heavy Pictures AUTOMATIC Ken i | " of ; | ° ° CLEAT Jf Instead of the ugly nail or common S| } tack which is never safe, use sf at | °° | 7 Moore Push-less H ach i *% oore ruSn-ieSs Mangers ent 1 The Hanger with the Twist 32 “THE ~ ——— - The Hanger is flat against the wall; the CAL PISTOL ‘aps ? crea 7 24 : mi inserted onan angle, and the weight be That = o > e of the picture up to 100 pounds—is prop- aoe this By following the design and the erly distributed. For light pictures, 15 veneer ~~ — two measurements given here with care, photos, etc., Moore Push-Pins — Glass — . : . ee ie eat eS : Sean, QUICK Before buying ask your rap you will avoid disappointing errors Heads, Steel Points, are used by millions. Gaalao’ aiuat the sis iil Suggest a use and we'll send samples free SHOTS, bata geen me aper Sold by Hardware, Stationery, Drug per NO mide Pe the appearance of the table. The small and Photo supply Aree sync tos pkt. JAMS @ Ga Qo * Sam ring drawer directly underneath the top of the Moore Push-Pin Co., 11-6 Berkley St., Philadelphia a & ont $5 table may also be omitted, but it will be Get a Warner “infallible” Automatic and teach the ° s women how to plug the bull’s eye. Target shooting is found convenient for stowing away memo- oe ——— intense, ¢ xeiting sport — at Gunny See Oaeves one . € eac Lt € ce conhaence anc amiliar ' randum books, paper, pens, etc., if the Standard Underwoods with weapons, What a Shooter Says :" Your ‘Infallible’ table is used for writing purposes. 5-Year Guarantee seven shots in bull's eye one inch in diameter at distanes Yes, this genuine Standard Visible Wrk- of twenty-five feet with the pistol. The accuracy of this arm is a od by any regardiess of price. ; Cc. S. Hoffman, Oakwood Avenue, Orange, N. J. w is ° ; FREE LESSON OFFER } Do Not Use Your Tongue; than factor An authority has prepared for teh, ‘ price, satens 4 3 NG. us, @ set of six lessons on the n be Use a Moistener a for8s.idown lng Benny nye yroornans mom ’ the ; : f monthly payments. value in the use and care A a VERY efficient moistener can be made mi? Days ie oe iy Wee taki fer Wasted ae ’ P ” < P 4 3 r eee Se lar and terms of Free Lesson vie gsm an ty cintment jer and on | Peta ieae, es htly i de-mouthed bottle as follows: Take n ER PORIUM A-214 Shipman Buildin KIRTLAND BROTHERS co., Ine. oat three or four pieces of cheesecloth and tie cp semen ene * eae a 96 Caambers St. ( Dept P-S.) New York them over the —EEEE a ia ne mouth of the b bi th Tih iy) BOTTLE hottie. then oak | ~ KEEP TO "THE RIGHT! sat hall, then put | | -ADAMS cme | it 4 a small quantity | USE WHITING S ml craigs ( | ue SEE BRUSHES | cheese cup, set the bot- | to put Varnish and inane! ’ CLOTH = tle: with cheese- I | onto surfaces permanently. They spread color and varnish ai loth in the wi I | oe hey insure against crawiin , Scaling, or spotting, and create a cen eee | highly polished mirror surface. NA and the moisten- it 7 Send for Illustrated Literature er is ready to use. I | Ric JOHN L. WHITING - J.J. ADAMS CO., Boston.U.S.A. _ This will be 1 | Manufacturers for Over 110 Years and the Largest im.the World. ~. - found very effec- iling, eal 7 ; ; : é the Use a moistener tive in applying ee hls | instead of your labels, stamps, | tongue ete. Teena eomenmeN wasnt - thly

June, 1921

93

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Fascinating Big-Pay Field That You Can Put Your Heart Into No matter whether you wish to visit every nook and corner of the world or whether you have no desire to travel—here is a fascinating field that Both on land and on sea these splendid opportunities are calling you. And now, through a wonderful new inven- tion, you can quickly and easily learn Wireless at home in your spare time and become a licensed A fascinating big-pay field that you can put your heart into is eargly awaiting your Read how you can step into the won- offers you big pay in either case. operator. services. derful future it holds for you.

Wonderful New Invention Makes Wireless Amazingly Easy to Learn From every branch of Wireless comes the call for opera- tors! From the sea comes the call of the U S. Merchant Marine, operating over 30,000 vessels that ply over every ocean Private ste amship lines whose ships reach India, Norway, Africa and ports in every part of the world also sound the call. Big opportunities are offered, with the chance to see the whole world, as an officer with luxurious quarters and good pay. From the land too, comes the call of the new forces that have formed to make wire less the greatest means of com- munication in existence. The Radio Corporation of Amer- ica, with $20,000,000 capital, 1s establishing land st ations in every section. The Independent Wireless Telegraph Co. is carrying out tremendous expansion Business Houses, Railroads, Police Depts., Newspaper Publishers, Com- mercial Clubs, Banks, Agricultural Stations, Civil Se Tvice in every field Wireless is being adopted as an essential de- partment of the business. And now as never before is your big life-time opportunity to get in on the wonderful future this fascinating field holds for you. Cash in on the World’s Expanvion If you have kept pace with the world you know why Wireless offers you a future which nothing else can. You know that this amazing field has only taken one step com- pared to the enormous strides that are yet tocome To-day Wireless is building itself into one of the most gigantic forces ever known. You can cash in on this expansion. You can now easily and quickly qualify for the splendid inducements it offers The National Radio Institute is today the oldest and largest wireless school in America teaching wireless by mail. This Institute is officially recognized by the U.S. Depart- ment of Commerce, its diploma is given official credit, its name heads the list of schools recommended by the Shipping Board. And through a wonderful new invention patented by its President, the National Radio Institute will qualify you for a fine Wireless position in a short period during your spare time. Special Opportunity Now Open Through this remarkable patented invention, the Na- trometer (given, without extra cost, to each student), and our interesting home-study course the National Radio Institute makes it easy for anyone to learn Wireless at home; no matter whether you know a thing about it or about ele ctricity at the present time. The urgent need for operators and the calls which come to us for our students prompt us to make a special offer open to new students for a limited time. Through this special offer your enrollment will be accepted at a special rate and you will receive without extra cost our new course in Wire- fess Telephony Let us tell you how you can travel all over.the world with easy work and good pay. Or, if you wish, you can accept one of the big wireless positions on land which are now urgently in need of your services. Mail Coupon for FREE BOOK It costs you nothing y get our interesting illustrated booklet, ‘Wireless, the »portunity of Today.’ Mail coupon today for this Skint and for full facts about our special Short-Time Offer. Fill out coupon now-—then mail it today! National Radio Institute, Dept. 86, Washington, D. C. [°7~ 7° RUSH THIS SPECIAL COUPON °"""" National Radio Institute, Dept. 86, Washington, D. C. ' Send me your FREE book, “Wireless, the Opportunity 4 1 I 1 of Today. Tell me about your Home Study Course in 1 , Wireless Telegraphy and your special Short-Time offer. i | Name. I I OREO EN OT OE ER PY eee l t I t City Vere Narre I ‘ — cece moO amare Eee mom aosowa

Only $45.00 For This Job rat Save exorbitant freight rates and one-hi original cost by buying Ford

ple, complete instructions fur- nished, all parts cut to exact fit. Any onecan assemble this job. Comple te with hood, radiator Shell. instrument board, ppnoletating. metal parts, wood parts, bolt screws, etc. Flat radiator shell furnished made up Designed low with lack of wind tesistance. Price set up $90, further particulars on request. The Central Auto Supply Co. Eng. Dept. 122 Louisville, Ky. e Net Paper Patterns All Parts Complete

“Success in Music How To Win It” LET Sousa, ph a and eight other world-famous musi- cians tell you secrets of their success; how to discover and cultivate your musical * ‘bump”’; double your income and pleasure playing in band or orchestra. FREE TRIAL Any Instrument Conn instruments are used by * world-famous artists. Known every- where as easiest of all to play. Try any instrument FREE. No _ obligation; easy payments when you buy. Sen coupon for free book and details of free trial com.

632 Conn Bldg Elkhart, Ind. Agencies in all large cities ao a a oe a C. G. Conn, Led. 632 Conn Bldg., Elkhart, Indiana. Gentlemen:—Please send me ‘‘Success in Music” and details of your free trial plan. (Mention instrument.) ee Street or Rural Route 6 ee State —

Instrument

(fo ) KEROSENE ENGINES LATEST DOESIG

Durable, Powerful, Reliable, Mas- sive. Built to last; to do ‘hard, heavy work. Uses Cheapest Fuel. Pull \ to 4 horse-power more than rated. Lowest Prices. 3 Months Trial. Easy Terms. Sizes 14 to 22 H-P. Easy to start. No cranking. No batteries. 10 Year Guerames. a e orm ea engine ever built. Engine book free. A postal brings it. THE OTTAWA MANUFACTURING Co. 1951 King Street, OTTAWA, KANSAS

ngmen gam od Evans, carpente my 60, now MAKING $1 a@ week in shop ibbard of b Mich. age 62, learned URGERY, has shop in small town, ash receipts for May, June and July, “7 is easy to learn. J will teach you in two weeks, Within thi 1a’re started on road to fortune. Car ir meth- ‘es Wear- vs AN MORE Tire Sur- cere’ pest bedi. Y M can succeed It’s q Sno BASY step into automo- ile industry —the field that has made men rich. It “bo in oes for John W. Blair. Ohio, 30 a8 00 for Fleming, of New 3 Get de- Send coupon at once for the FREE bool

Mr. Maveere Pres., Co. Capicl A Dear si full details’ of Ti inalenapeltas ng Send jurgery as I want to get into big paying business quickly. ‘ Name.

Addrees_____

Popular Science Monti'y Expanding Lead Plug for a Casting Hole

SMALL hole in a casting, as a sand hole, can be readily closed with a piece of lead the size of a shot, calked in with a blunt-nosed tool. A larger hole, 14 in. or more, requires a plug of such <ize that a _ successful LEAD -—\ calking job is not PLUG practical. In the event that the cast- ing will stand threading, a tapped ok ws plug is correct and makes a serviceable —~ CASTING repair. A thin casting, especially of cast iron, cannot be tapped for a dependable thread. A repair under these circumstances is made wit! a round lead plug and a small screw-bolt. Drill a hole through the plug smaller than the screw-bolt and drive this in. Then drive the plug in the hole after truing it up somewhat; with a drill set a washer over the screw and put on the nut. The nut can be screwed as tight as required; expand the lead and pack it solidly about the hole.—G. A. LUERS. The plugs the hole in the casting lead bushing Bottle-Caps as a Back-Door Foot-Scraper ERE is a scraper that will take off the worst mud from shoes. It can be made at home from bottle-caps. These metal bottle-caps, with which so many of our bottles are closed, are saved until! a

number of them have been col- lected. Then a 16-in. board of any convenient length and width is taken and two strips of narrow wood are

screwed on each end to prevent warping.

The bottle-caps are nailed to this base, using two nails for each cap. A neat appearance is given to the scraper if the caps are nailed in parallel rows. This scraper is cleaned by simply jarring the dirt loose. Discarded bottle-caps made this foot-scraper Prevent Your Saw from Slipping Away See pahdaaageg when a carpenter’s saw is laid upon a roof of considerable pitch, it has a tendency to slide off. This can be prevented by a simple means shown in the illustration. Bore a hole in the saw handle and drive a long wire nail through it of slightly larger diameter. It should project at least an inch on each side. Then the head should be cut off and both ends of the nail filed down to a sharp point. No matter which side of the saw is laid down on the roof, one end or the other of the nail will stick to the shingles and pre- vent the saw from slipping.— L. B. ROBBINS.

A nail will prevent the saw from slipping

June, 19% A Co Sin OR th who wi their hom making a =) 2

Perspe: handso be mad combinati the library The ger shown in the detai necessary diagrams. The che amateur c select stro ing with 1 room. T' may be o is

» +———20"— By fo measur you wil the appes drawer di table may found con randum | table is 1 Do Ne \ VER from old wide- three or f

Use a instead tongue

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he be ips his wo ip. eT ch, be the ive tly ast June, 1921 A Combination Table of Simple Construction OR the benefit of amateur carpenters who wish to add to the furnishings of their home, directions are given here for making a useful as well as an ornamental Bx ——24" Perspective view and side view of a handsome combination table that can be made with a few tools combination table, the library. The general appearance of this table is shown in the perspective illustration and the details of its construction and _ all necessary measurements are given in the diagrams accompanying this article. The choice of wood is left entirely to the amateur carpenter. It is best, however, to select strong hardwood of a color harmoniz- ing with the color of the furniture in the room. The rail on three sides of the top may be omitted without detracting from a | exo 4x i" ; ) lA x. particularly suited for j}——_——— 24" —__ ge laxie ip | a 4 219 SCREWS Q Q DRAWERS yy ° CLEAT ; 98 99 “," BACK +#———20" 7” 24" By following the design and the measurements given here with care, you will avoid disappointing errors the appearance of the table. The small drawer directly underneath the top of the table may also be omitted, but it will be found convenient for stowing away memo- trandum books, paper, pens, etc., if the table is used for writing purposes. Do Not Use Your Tongue; Use a Moistener VERY efficient moistener can be made from an empty ointment jar and an old wide-mouthed bottle as follows: Take three or four pieces of cheesecloth and tie them over the mouth of the bottle, then put a small quantity of water in the cup, set the bot- tle with cheese- cloth in the water and the moisten- ; er is ready to use. This will be found very effec- Use a moistener tive in applying instead of your labels, stamps, tongue etc. BOTTLE CHEESE CLOTH that give long service. —=—OF request. Manufacturers le HE fine details of Florsheim a | | style are an expression of \,, careful making and sound quality Ten and Twelve Dollars The name in every pair Spring Booklet —‘“‘Styles of the Times” 1i THE FLORSHEIM SHOE CO. Chicago The “Kenwood” — Style M-65 The Scientific Way to Hang Heavy Pictures Instead of the ugly nail or common tack which is never safe, use Moore Push-less Hangers The Hanger with the Twist The Hanger is flat against the wall; the pin isinserted onan angle, and the weight of the picture up to 100 pounds—is prop- erly distributed. For light pictures, photos, etc., Moore Push-Pins — Glass Heads, Steel Points, are used by millions. Suggert a use and we'll send samples free Sold by Hardware, Stationery, Drug 15 per and Photo supply stores everywhere pkt. Moore Push-Pin Co., 11-6 Berkley St., Philadelphia Standard Underwoods 5-Year Guarantee Yes, {pie enuine Standard Visible Wri- than factory price, yours for$3.00down and then easy monthly payments. 10 Days FREE Trial Try it for fy days at our risk. woney back guarantee. Send now for free book — bargain offer No.2145 ~ TYPEWRITER EMPORIUM A-214 Shipman Buildin; Montrose and Ravenswood Avenucs Chicago, Illino WARNERS "Witiitté 32 “THE CAL PISTOL - . ~ That 15 shoces ee pi ey ear SHOTS, Warner |“ infallible “9 NO w& et the best — “on Get a Warner “‘Infallible’”’ Aut tic and teach the women how to plug the bull’s eye. Target shooting is intense, exciting sport Excellent training for nerves and eyes Sous ches self-reliance, confidence and familiarity with we apons. What a Shooter Says :*' Your ‘infallible’ Automatic Pistol is all that you claim and more. I put seven shots in bull’s eye one inch in diameter at distance of twenty-five feet with the pistol. The accuracy of this arm is ag ge by any regardless of price.”’ Orange N. J Cc. S. Hoffman, 157 Oakwood Avenue, FREE LESSON OFFER An ow has prepared for us, a set of six lessons on the Art of Pistol Markmanship. These lessons are of marvelous value in the use and care Of a Warner“ lible’’ Aut ti Write today for Sincerated cir- cular and terms of Free Lesson er. KIRTLAND BROTHERS co., INC, 96 Chambers St. ( Dept P-S.) New York ~ KEEP Te TO “THE RIGHT! I | cule, sees permanently. highly polished mirror Cll satin USE WHITING-ADAM a BRUSH ES a. put Varnish and Enamel ey spread color and varnish evenly. 1 | They insure against crdeding. scaling or spotting, and create a S Cmte cay, end for Illustrated Literature JOHN L. WHITING - J.J. ADAMS CO., Boston,U.S.A. Manufacturers for Over 110 Years and the Largest in.the World. surface. in oe

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Electricity Learn at Home There is a wonderful opportunity right now for young men who like electricity. If you are ambitious and will train yourself in spare time you can step into a good position and get experience that will give you a real start toward success in life. Good salaries are offered with rapid promotion. For 29 years the International Correspondence Schools have been training young men for success in electricity and over 200 other sub- jects. They will help you prepare right at home for a position in the line of electrical work you like best —or in any other work that appeals to you. Thousands of men, through I. C. S. training, have stepped into fine jobs, but never were oppor- tunities so great as now. Let the I. C.S. help you. Choose the work you like best in the coupon below, then mark and mail it today. This doesn’t obligate you in the least, and it will bring you information that may start you on a successful career. ‘This is your chance. Don’t let it slip by. Mark and mail this coupon now. ee eee oe eee = TEAR OUT HERE cee eee eee eee ee INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7626-B SCRANTON, PA. Explain, without obligating me, how I can ouety for the Position, or in the subject, ent which I mark X.

How, Soldiers in Texas Built an Ice-Chist HE ice-chest shown and described here was built by the writer and his com- rades while they were stationed with the army in Texas. The front and rear sections were made, as shown in the drawing, of 2 in. by 4 in. seantling. One side was covered with

am f' 6”

ELEOCTRIOAL ENGINEER Ae Aome Electric Lighting and Kys. ADV TISING Electric Wiring Window Trimmer Telegraph ~ = Show Card and Sign Ptg. Telephone Work Railroad Positions MEOHANIOAL ENGINEER | © ILLUSTRATING |Mechanical Draftsman 4 lO) Cartooning Machine Shop Practice » |CJBUSINESS MANAGEMENT ——— ” |) Private Secretary ne Operating a CIVIL ENGINEER 3 _ Business Correspondent Surveying and Mapping “| MINE FOREMAN or ENG'R|"E [Gere pee A ee et STATIONARY ENGINEER | 3 |= TRAFFIC MANAGER Marine Engineer : Railwa Ship Draftsman é ne Law ARCHITECT &|}GooD ENGLISH Contractor and Ballder © |) Common School Subjects Architectural Drafteman = . CIVIL. SERVICE Concrete Builder 3 ) Railway Mail Clerk Structural Engineer AUTOMOBILES neers te oe & Mathematics eet Metal Worker —- Textile Overseer or Supt. po [Bessie neal 2 a Raising Banking Name Present Business witcites Occupation Address ____ Street ae oe City State

Canadians may send this coupon to International Corre- spondence Schools Canadian, Limited, Montreal, Canada

Soldiers of an American regiment stationed on the Mexican border built this refrigerator matched beards, the space between the 2 in. by 4 in. was packed with hay and the boards were nailed on the other side. Cleats were run along the inside of each section abcut 2 in. above the bottom of the boards so that a 2-in. air space would be allowed between the earth and the floor. The front and rear sections were then set up, squared and levelled, and a 2 in. by 4 in. was nailed at each end, as shown in assembling plan. Ancther 2 in. by 4 in. was laid between the front and rear sections to form a bottom for the sides or ends. The boards were then run up on the sides. The pockets thus made were stuffed with hay and an- other 2 in. by 4 in. was cut in to close it tight. The top icing door and the front door were made as shown in the door detail, the MATCH BOARD

fe} HINGE TOP COVER TO 2X4" TOP COVER FITS HERE AIR SPACES PACKED WITH : ip HAY OR BRAN / qr etetee A 2x4" 7 BOARDS *BOTTO CROSS SECTION OF DOOR DRAIN PIPE TOP SHELF TTOM SHELF BRACKET CLEAT "8 8" "6" —> These diagrams show the construction of the double-walled ice-chest and its dimensions outside board being allowed to project about 2 in. beyond the door itself on all sides except the one on which the hinges were placed. The ice-chest described was doing duty for a troop of eighty men and was very 94

Popular Science Monthy Send No Money 21 JEWEL ILLINOIS eg The greatest watch value ever offered. Un- equalled for beauty, ac- curacy and reliability. 21 ruby and sapphire jewels justed to positions, temperature and isochronism, 20 year gold-filled case. 10 Days Free Trial Wear it for 10 Days at our ¢ » risk. Note its absolute ex actness. If at the end of tu days‘ you are not satisfied, just send it back at our expense. Knife and Chain Free We are offering for a limited time this handsome gold- filled knife and chain ABSOLUTE- LY FREE. lic a Day Just send your name and address. wateh, chain and knife come to you j Give the expressman $8.50 as . ieedit. we! after 10 days, you do not wish to keep them return at our expense; your deposit will be ite nied instantly, Trial is absolutely free. SF, ‘ou keep the watch p: .40 a month until fi price of $42.50 is paid, is splendid watch § will cost you less than lle a day, Act atonce. Address Dept. 471-L Capital $1,000,000 *“*THE HOUSE OF QUALITY”’ W. SWEET, INC 1650-1660 BROADWAY, NEW YORK *

THE OLIVER OIL-GAS ae Rakes cooking in summer a pleasure instead of a task. n yeu want it—not a tsinute longer than you need it Does away with coal and wood—cheaper. Makes your stove or range a gas stove. No fires to make. No ashes, dirt, smoke, odor, chopping. shoveling -- carrying coal or w Saves hour Makes your stove Dake better, cleaner, quicker. years. Doesn’t change your stove, just sits ped in, fd out, at, vabsolutely safe. ts own gas from coal-oil (kerosene) at small cost. Gives even heat instantly, by Y "Sed und turning valve. Saves money, time, literature AGENTS WANTED. BIG MONEY. . Oliver Oil-Gas Saree, & Machine Co., Oldest Largest Mf: Oil-Gas B Burners, 2007-F PINE STREET, ST, LOUIS, MO.

MAKES YOU

. DEGREES OF SOUND The Latest Triumph q oa This Car VLBRATION, VOLUME fue Megriftene- . of Science This ~g 4 little car driven AND CONTROL. Ask for circular ““Makes You Hear.” This tells motor = fe put —SOUNDS THE KEY- all about it and how it becomes yours. ~ by any boy. NOTE OF YOUR EAR— The Magniphone Co., 29 E. Madison St., Chicago Dept. 26 New 1921 plans, big ger, better than r now ready Send % for ing plans and price jistot parts howing how to build thie lad’s car. SYPHER MFG. CO., 174 Sypher Bidg., Toledo, Ohie etiverea + for 30 daystrial onapproval. Your choice of 44 Styles, colors and sizes of famous Ranger Bicycles, Factory- oe lets you buy at wholesale rices, express 3 to Ps direct from maker. lets 4 po =e \ \2Months your Range t * once, ty boys — d girls he \

© small — Me a better t bicycle => cap buy anywaere 4 at any ey pes eels, parts Tess eauipment a “< bait usual he a pues a"

June, | satisfac nothing pan, wh This pa two 2 il vith the was car seted | Bulid ee tion years by It m handy | the writ this ma Thes on this “usted t his pa ig may or pails The ¢ Conl to v seasc long, wi Along t! 1y-in. h inches ¢ into the used. The } post is ; slip ove split in spl'ttiny made di three e: are dril Each li shape s the mo ordinar the gric the woc being b hang pr the gric Var fro1 A VE “. we is wate ties, co of rosin One | turpent linseed and tl) manner

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~*~ “Sw * Car tle cat asoline e built y boy. w 1921 s, big better | ever, ready id 3 build plans price »f parts ng how "scar, o, Ohie June, 1921 satisfactory in spite of the fact that it cost nothing to build except for a galvanized pan, which they had made to hold the ice. This pan rested on a board platform laid on two 2 in. by 4 in. which were nailed flush with the top of the front door. The water was carried off by means of a pipe con- octed with the pan. Buiid Your Own Camp-Stove for Yc r Vacation fibres camp-stove saown in the illustra- tion was used successfully for ten years by G. W. Conklin, the maker. It may be easily constructed by the handy man and Mr. Conklin freely gave the writer permission to tell the readers of this magazine how the stove is made. The supporting part is a post. Working on this is a movable part that’ can be ad- ‘usted to a height suitable to the heat used. his part carries three lids, on which cook- ig may be done as on an ordinary stove, or pails may be hung to them. The central post is an iron pipe 3 or 4 ft. Conklin camp-stoves are well known to woodsmen and are used at all seasons long, with its lower end welded to a point. Along the upper length of the post a row of 1j-in. holes should be drilled six or seven inches apart. This post is simply driven into the ground where the stove is to be used. The part that works up and down on the post is a piece of pipe just large enough to slip over the post and has its upper end split into three parts. Its length before splitting should be 3 in. and the splits are made downward for 1!4 in. In each of the three ears made by the splits, small holes are drilled to take the lids of the stove. Each lid is made from heavy wire to the shape shown and is attached to the ears of the movable part by being bent like an ordinary stove handle. The diameter of the griddles may be suited to the parts of the woodsman’s outfit, from 6 to 10 inches being best. Wire hooks should be used to hang pots and kettles to the under side of the griddles and to the main post. Varnish for Floors Made from Simple Ingredients VARNISH that is suitable for hard- wood floors in the house or shop, that is waterproof and has good wearing quali- ties, consists of the following proportions of rosin, turpentine, and linseed oil: One pound of rosin, dissolved in 1 pt. of turpentine to which add 2 qt. of boiled linseed oil. These are mixed thoroughly and then applied evenly in the usual manner.—G. A. LUERS. 4 Jobs Open to You $1.75 anhr. Auto Expert $40-$50 a Wk. Chautfeur $200 a Mo. Domonstrator $225 a Mo. - Tire Expert $4,000 a Yr. - Salesman $5,000 a Yr, Garage Mgr. $10,000 a Yr. Gar. Owner Business Don’t stay a Low-pay man wishing for a good, b€#€ _ ee steady income to come through ’ lucky breaks. Make your own luck. Take a short ’ ) cut to top pay right now. Come to the world-famous Rahe Auto & Tractor School. In 6 to 8 weeks Henry Rahe will fit you to pick F your job in the Automotive Business—the one business that needs more men than ever and pays the biggest money. Remember, it’s the | Rahe ‘3. School 2 Million Dollars Invested—Nearly 49,000 Graduates Learn Here Easily and Quickly and learn Right. You work daily doing real jobs under Master Instructors on all types and models of real Automobiles, Trucks, Tractors and Aviation Equip- ment. You learn by the Rahe Practical Job Method of Training—-the same metnod of training that has brought success and independence to nearly 40,000 Rahe Trained Men in every section of the country. You need no previous experience; no special schooling. Best of Living Conditions. Board and room always reason- able. Plenty of opportunity to earn part living expenses while here. , Get my fine 84-page Catalog and Special Catalog Free Tuition Offer Saws you go anger school or shop, Both are free. Address school neares* « ou. Calls for Rahe HENRY J. RAHE, Dept. 2881 Trained NY Kansas City, Mo. Cincinnati, Ohio Men Than ? =” Tires Cheap! “‘treav" Biggest Tire Bargains Ever Offered 6000 Mile Guarantee @ Can Supply! “4 v sae ’ Size rires rubes : CANOES: 30x3 $13.50 $2.25 i ‘Sarest to Use} = es i .) . . ® Because the “Tumble Home™ ¢ 3x4 18.12 2:75 e k h Th d d li ° 32x4 19.96 2.85 + makesthem so. e dotted line e 33x4 20.70 2.95 \ here is the “Tumble Home” : +99 a = ‘\. of ordinary canoes,the heavy 35x4'% 27.26 4.75 ‘. line of the Kennebec. ,” 36:44 27.60 5.00 x - a 35x5 31.30 5.25 %\ “Tumble Home” is the 2 37x5 32.70 5.50 ~ bilge of a canoe. ORDER NOW. Discount of 5% when ful? amount accompanies order. You should get our1921 illustrated book telling all about this wonderful feature of the Kennebec. Sent postpaid. KENNEBEC BOAT AND CANOE CO., 29 R. R. SQUARE, WATERVILLE, MAINE. CROW TIRE SUPPLY 203 W. 58th St. New York City, N.Y. Print Your Own cards, circulars, labels, tags, menus book, paper. Press $12. Larger $35. Job Press Siup. CUTS EXPENSEIN HALF "3 BSMALL OUTLAY. Pays for itself in short time. Will last for years. Easy to use, printed rules sent. Print for others, $4 or $5 witBty j A Standard, Guaranteed TYPEWRITER With Every Modern Writing Convenience BIG PROFIT, Write factory _ Write Today For Illustrated ecpe* for press coy make Circular Explaining Try-Before-You-Buy Plan TYPE, cards, paper,envelopes. EXCELSIOR [ania anna SMITH TYPEWRITER SALES Co. +, U-o8, Meriden, Gonn. (Harry A. Smith) 306 —218 No, Wells St.,Chicago, tl. SIMPLE WIRELESS TELEPHONES AND HOW TO MAKE CONSTRUCTION OF INDUCTION COILS THEM. An elemental book on the principles, constric- and Transformers. By rT. &. CURTIS. Open vom and use of an are system of wireless telephony. and closed core transformers are both taken up. ustrated Price, postpaid, 25 cents Pri 25 POPULAR SCIENCE MONTHLY aes cents 225 West 38th Street New York Popular Science Monthly - 225 West 39th Street, New York 2+Feet\my ONLY | LONS |= OO CENTS ACHROMATIC TELESCOPE MADE UPON NEW SCIENTIFIC PRINCIPLES, Positively such a good Telescope was never sold for this price before. Eastern Telescopes are made by one of the largest manufacturers of telescopes in America; we control entire production: measure closed 8 inches and open over 2% feet in 4 sections. They are nicely brass bound, with scientifically ground lenses. Guaranteed by the maker. Every sojourner in the country or at the seaside resorts should certainly secure one of these instruments, and no farmer should be without one. The scenery just now is beautiful. A Telescope will aid you in taking views. Objects are brought to view with astonishing’ clearness. Sent by mail or express, safely packed, prepaid, for only 99 cents. Our new Catalogue of Watches, ete., sent with each order. This is a grand offer and you should not miss it. We warrant each telescope just as represented or money refunded, Send 99 cents today. To dealers 6 for Four Dollars. EASTERN NOVELTY CO., DEPT. 24 172 E. 93d STREET, NEW YORK, 95 YOU WANT JUST WHAT

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= ; é LIGHT WEIGHT. CAST IRON BisTON PATENTED U.S.A. | FOREIGN PATENTS PENDING You CANT GO VERY LIGHT ano VERY STRONG Do You Own a Car? DELUXE light weight, cast iron pistons will increase the power, speed and flexibility of any motor and at the same time use less gasoline and oil. They also reduce repair bills by eliminating vibration. Thousands of motorists in every part of the world are proving this very day DELUXE PISTONS ARE 40 TO 50% LIGHTER THAN STOCK FACTORY CAST IRON PISTONS The weight is saved and strength gained by their )atented scientific reinforced construction. Note the rein- forcing ribs under the head and down the skirt. These veinfarcements give the piston much greater strength. The reinforcing ribs also serve to carry off heat, insuring a cooler running motor. The DELUXE piston has vuch less expansion than either aluminum or heavy ast iron pistons They can be fitted close Write for booklet giving full information. Supplied standard or over-size for more than 800 makes of automobiles, trucks, tractors, airplanes, motorcycles and marine engines Patented and Manufactured by CLARK-TURNER PISTON CO. Station C » Los Angeles, Calif. For Sale by All Good Dealers and Repair Men. All at the Same Time . P The Hottest Fire Noiseless Known for Cooking Send for Free Illustrated Catalog of the Little Wonder Oil Stove Designed from suggestions of women oil stove users the country over. Enclosed top (which allows of no wasted heat up around sides of cook- ing utensils), and forced air feed (stove burns 90% air to 10% oil), makes one central burner and one gal. of kerosene do the work of any other oil stove with 6 burneis and 10 gals. Pays foritself quick in saving of fuel. No wick or asbestos rings; no dirt; no danger; odorless. Cooks fast or slow as desired. Top accommodates four 8-in. utensils at once. Oven roasts, bakes, broils perfectly. Quickly generated ; simply operated; strongly constructed ; occupies but little space. The greatest oil stove ever invented, and price only $17.50 f. o. b. fac- tory. Send for Catalog NOW. Little:-\Wonder Stove Co. 17267 GABLE AVE. DETROIT. MICH. NM 3 Build and Fly Model : _jseroplanes Build a Model Aare © that will fly like a real one AL Scale Drawings and ed a Flying Instructions you can easily build exact, 3ft. duntcates of Big Aero- planes Send now for Drawings and nstructions for the one you will build: Curtiss JN4D-2Training ‘Plane, De crea c Battle ‘Plane, NC-4 Naval Seaplane,Curtiss Military Tractor, Bleriot Monoplane, Nieu- port Monoplane, Taube Monoplane each Catalogue of IDEAL Model » rune roplanes and Supplies, 5c Postp Ideal I & Supply Co., Cor.W. Houston & te Sis. N.Y.C. Home-Made Toys for Girls and Boys Here is a veritable gold mine of suggestions for home-made toys, each one of which has been carried out successfully many times. Price $2.25 Metal-Sawing Method that Aids Efficiency ETAL sawing can be done more efficiently by supporting the saw at one end. The workman can make a longer cut than without such support, employing a long blade, with a consequent saving of time. As the blade is now guided throughout the stroke, it is no longer subject to the Rigged up in this manner the hacksaw does better work and can be operated with one hand frequent breakage occurring in this class of work, and no gripping is to be feared, hence it will be seen that this very simple method presents decided advantages. Tests made at the railroad shops were very successful with a 35 per cent saving of time.—FRANCIS P. MANN For Cutting Circular Gaskets or Washers EREWITH is illustrated a machine for the cutting of circular gaskets or washers. This little device will often be found useful in a garage repair-shop, and at times will be instrumental in saving time. It consists of a hardwood rectangular base A cut to such size as to accommodate , HANDLE LEATHER. The large screw supports the cutter and regulates its tension and depth of cut bracket B, to which is riveted the square nut C, acts as the bearing for the screw D. This is provided with a hole at its swiveled lower end, through which passes the cut- ter F. The cutter is adjustable, and may be set for any size of washer; while set-screw G holds it firmly in position. The handle E, was provided to facilitate the operation of the pressure screw. The leather or felt is held with one hand, while the cutting is done with the other.—ADOLPH KLEIN. Popular Science Monthl; Automobile | Books | The Model T Ford Car Its Construction, Operation and Repair, Including the Fordson Farm Tractor, F. A. Lighting and Starting System, Ford Motor Truck. By Victor W. PAGE. 410 pp., 153 illustrations. Price, $2.00 The Modern Motor Truck Its Design, Construction, Operation and Repair. By Victor W. PAGE. Treats on all types of motor trucks and industria tractors and trailers and considers all type of trucks, gasoline and electric, and all varieties of truck bodies. 800 pages, 750 illustrations. Price, $5.00 Motorcycles, Side Cars and cycle cars. Their Construction, Man- agement, and Repair. By Victor W. PAGE. Describes fully all leading types of ma- chines. 500 pp., 350 ills., 5 folding plates. Price, $3.00 Automobile Ignition, Starting and Lighting, with Questions and Answers By CHARLES B. HAYWARD, M.S.A.E. comprehensive analysis of the complet« electrical equipment of the modern automo- bile. 1,024 pp., 740 wiring diagrams and ills, (including 128 blueprint diagrams). Price, $3.75 Storage Batteries Simplified Tells how to charge, care for and rebuild storage batteries. Also outlines their i: dustrial uses, including how they are used in central station standby service, for starting automobile motors, and in ignitio: systems. 208 pp., illustrated. Price, $2.00 Automobile Repairshop Shortcuts Contains over 1,500 time and labor saving methods and devices that have proven ex- ceptionally helpful in repairing or adjusting engine clutches, gear-sets, running gears and bodies, etc., and in managing and equipping shops. Here is the opportunity to study th« methods of over five thousand experts wh were all striving to find a better way to d some job and to shorten the time required to do it. 1,500 illustrations. Price, postpaid, $3.50 Automobile Repairing Made Easy. By Victor W. PAGE. thoroughly practical book containin: complete directions for making repairs t all parts of the motor car mechanisn 1,056 pp. Price, $4.00 How to Run an Automobile By Victor W, PaGe. Gives concise i! structions for starting and running all mak« of gasoline automobiles and how to care fo! them. Describes every step for shiftin gears, controlling engine, etc. 178 pp., 7 illustrations. Price, $1.50 Popular Science Monthly 225 West 39th Street New York City Popular Science Monthly "225 West 39th Street, New York 96. J une Let it you it, y! troug W: as sk illust less badl: punc or i may Place the you yard them wat heav and rubb or bi Try H I hand exam both air. Th is at flowe paint the fi hand while ing going appez two chiefs toget Th zles and e dinar elasti detec think for su It she preset separ: but with ¢ tricks its p MERR If ¥ N° 4 S| electri availa be dor -— Piec insu wire

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June, 1921 Let Chickens Drink from a Rubber Trough T° you have an old automobile tire that has outlived its usefulness as a tire, and you have no other more important use for it, you may transform it into a watering- trough for your chickens. With a sharp knife cut the tire in halves as shown in the illustration. Un- less the tire is badly worn and punctured, either or both halves may be used. Place them on the ground in your chicken- yard and keep them filled with water. Even CUT TIRE IN HALF

€====—5

SECTION OF TROUGH Half an old tire forms a_ water- trough for chickens heavy chickens cannot upset this trough and their feet cannot be injured by the rubber as they sometimes are by tin pans or basins.— WILLIAM F. PAYNE. Try this Handkerchief Trick at Home ERE is a pretty silk-handkerchief trick that any one can do. Two silk handkerchiefs are shown and passed for examination, if so desired. Then they are both taken in one hand and tossed in the air. They fall down knotted together. The ‘‘key”’ to this simple bit of conjuring is a thin rubber band, such as is used in flower shops or a small band of any kind painted white. The band is slipped over the first finger and thumb, the ends of both handkerchiefs are allowed to be banded while the throw- ing motion is going on. The appearance is of two handker- chiefs knotted together. The trick puz- zles onlookers and even an or- dinary rubber elastic cannot be detected. No one thinks of looking for such a thing. It should not be presented as a separate item, but mixed in with other parlor tricks it answers its purpose. — MERRITT HALE.

Surprise your friends with this simple trick If You Have No Insulating Staples, Make Them NOt every household is equipped with a supply of wiring staples for insulating electric wires. When such staples are un- available at a time when some wiring is to be done hurriedly, they can be improvised

< wires STAPLE RUBBER Pieces of inner tube insulating electric by using double- pointed carpet- tacks with pieces of old inner tube, about 34 in. square, as insu- lators. The illus- tration clearly explains how it is done.

1/, HP Motors $13.50 | We offer 5000 quarter Horse Power ALTER- NATING CURRENT MOTORS of the very latest type, 110 volt, 1740 RPM, 60 Cycle single phase at $13.50 each FOB Chicago. May be attached to any light circuit in the home or power circuit in the factory. Remarkably simple in design and ‘sturdy in construction. Fan-cooling ventilation system prevents overheating. These motors carry the Manufacturers ONE YEAR GUARANTEE against mechanical defects and are shipped to purchaser, ready for use in original container just as received from factory. Satisfactory performance guaran- teed, or money refunded. AT THIS EXCEEDINGLY LOW PRICE CASH MUST ACCOMPANY ORDER. SPECIAL PRICE ON THREE OR MORE MOTORS OF $13.00 EACH. These Motors are Ideal for use in the home on washing or ironing machines, or on the bench; in the garage or machine shop or any place where one can be used. They are quiet cool running, efficient and practical —with a very small chance of getting out of order. OUR SUPPLY AT THIS PRICE IS al : LIMITED TO THE ABOVE NUMBER ouble terminal—can be reversed from out- GET YOURS BY SENDING IN ORDER NOW. = ee 6 plug

Single terminal—with cord and plug—Non- Reversible.

Northwestern Electric Company 410-420 So. Hoyne Ave., Chicago, Illinois

; i vat 2.1 toD Motoreycle Bargains « «| ¢ 2» Learn to Dance SAVE /o to 65 eds Youcan learn Fo:-Trot,One-Step, Two- on Slightly used pee Rebuilt Posey 2 P Step, Waltz and latest ‘‘up-to-the-minute’’ so- x cycles, Side Cars, Johnson Motor # all ciety dances in your own home by the wonderful Wheels, Evans Power Cycles, Bicycles = Peak System of Mail Instruction.

Send for Free Bargain Bulletin and cal New Diagram Method. Easily learned; no Money Saving Message, listing hun- += music needed; thousands taught successfully; dreds of Bargains in used, rebuilt and <=) j 3 success absolutely guaranteed. new machines,su pplies, accessories, etc. Or \w o Write for Special Terms. Send today for FREE information and surprisingly low offer. ILLIAM CHANDLER PEAK, M. B. Room 39 4737 Groadway, Chicago, ‘11, AMERICAN MOTOR CYCLE CO, . Dept. 602, 2017 W. , Chicago Ave. CHICAGO ¥ CLIMB-'-° dX ABOARD igi ansipni= WV ae EN | —=WANTED | iio TRAFFIC INSPECTORS Earn Up To $250 and $300 Monthly Travel, see the country, meet influen- tial people. Easy, pleasant profession, inspecting traffic. 1500 Men Needed Now. You Can Easily Qualify || Simple, spare-time study for 3 months,

MakeYourBike aMotorcycle FASY to do and at low cost. Your old “foot power” bicycle can be quickly transformed to a speedy, easy-run- ning high power Motorcycle with the

that’s all. Then we GUARANTEE posi- meen: Pome cae hence enon LS ; 2 ae 259 whee its any men’s bicycle of any make tion: start at $110.00 monthly, all ex Satie. Chain tilde anni eam be attended penses paid; you can quic kly increase in less than an hour. A boy can putit on. your income after experience. Steady Position assured. No books to buy. Very moderate fee, which is refunded if position is not se- cured. YOU TAKE NO RISK, Decide to Investigate Get full details of this new, fascinating profession, Opportunities are greatest Now, Send for our Free Booklet D-227 Standard Business Training Institute BUFFALO, N. Y. No special tools or knowledge necessary. SHAW: Thousands in use. A light weight 24 H-P motor of wonderful efficiency. Simple to attach. Everything furnished complete. Every owner enthusiastic. All materials are guaranteed. Get one NOW. FREE Write at once for Free Book and Low Direct Factory Price on the Shaw Attachment, also the Shaw Motor-bicycle--a complete power machine at a low price. SHAW MANUFACTURING CO. Dept. 1466 Galesburg, Kansas

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Do you know that Clear-Tone —the wonder-working lotion —used like toilet water— Clears Your Skin of Pimples, Blackheads, Acne Eruptions, Enlarged Pores, Oily or Shiny Skin? Hlegant after Shaving. Indispen- sible for sensitive and refined women. GUARANTEED to banish unsightly blemishes easily and quickly, and leave the skin clear and smooth. e ‘A Clear-Tone Skin’’ Se RR MME: This Free Booklet tells how you can easily and quickly at home obtain a clear skin, free from all blemishes, like Nature intended you to have. Thousands of copies of this interesting books are distributed every month. Clear -Tone iso a cure-all ora mail-order treatment, but a scientific, reliable SKIN LOTION, perfected after 15 years personal experience by Mr. E. S. Givens, who knows every embarrassment one has to suffer with a bad complexion. Endorsed and prescribed by physicians, druggists, and thousands of enthusiastic users, and sold on a direct and posi- tive guarantee of satisfaction or money back! The marvel of Clear-Tone is that it clears the com- plexion so quickly, no matter what the cause. Clear - Tone 28 had an unpre- cedented success as evi- denced by thousands of voluntary letters written by men and women who had very bad blemishes and tried various soaps, ointments, and doctors without relief. Read These Letters! From U. S. Hospital-- ‘Find myself improving wonderfully. Any one I see that has skin trouble your wonderful Clear-Tone will be recommended.”’ Chas. A. Rein,U.S. Hospital 41, Staten Island, N.Y. From a Barber--‘‘Have been abarber for 30 years and never saw anything as good as Clear-Tone. All barbers should know aboutit.’’ Otto Van Burin, Kansas City, Mo. From a Musician--‘‘I am obliged to be in public a great deal and my complexion was a great embar- rassment. Clear-Tone improved me so greatly that I strongly recommend it.’’ C. H. Lindeman, Steu- benville, Ohio. From a Lady--‘‘I cannot thank you enough for all the good it has done me. One bottle has cleared my face wonderfully.’””’ Miss Wary Yonks, Haver- straw, N Y. From a Soldier--‘‘It is certainlywonderful.’’ Louis Langer, Troop F, 3rd Cavalary, Ft. Ethan Allen, Vt. From a Flyer--‘‘Cleared my face of Acne.’”’ H. J. Howald, N. H. Station, Pensacola, Fla. People Amazed--‘‘Has cleared my skin completely of pimples and blackheads. Everybody who sees meis amazed.’”’ R R. Wilson, Pearson, Ga. : Thousands of Others--men and women--praise Clear-Tone. We’ll gladly send copies of most in- teresting testimonials. FRE, Simply send name today for FREE booklet, ‘‘A Clear-Tone Skin’’ ummm telling how I cured myself after being afflicted for 15 years, and my $1,000 Guar- antee to clear your skin of the above blemishes. E. S. GIVENS, 158 Chemical Bidg., Kansas City, Mo. draw your own designs. Linoleum Blocks Used in Cloth Printing BLockKs for printing conventional pat- terns on table-covers, napkins, and other textile fabrics for the purpose of ornamentation may be made from heavy linoleum which is extensively used as floor- covering. All that is required is a smooth piece of linoleum, a sharp knife, indelible inks, and a certain skill in drawing. If you have artistic talent, invent and If you are not so Ornamental designs may be printed on cloth by patterns cut from linoleum and tacked to wood blocks gifted, borrow or copy a design from books, magazines, or illustrated art works. Draw or copy the design on paper and transfer it reversed on the linoleum by tracing it through carbon paper. The _ outlines should be drawn sharply and inink. Then, with a sharp knife cut through the linoleum along the black lines and remove the pieces that represent the white parts not showing in the print. The linoleum is then mounted on a block of wood with small nails, inked with a wad of cotton, and pressed on the cloth in the proper place and position. With a little artistic skill very attrac- tive combination patterns for borders, centers, or corners may be produced. An Awning for the Canary’s Cage ANARIES do not like to be in the sun and invariably seek the shadiest part of their cage To provide an awning for the bird, take a few strips of stout wire or banded brass, bend them to the desired shape with a pair of pliers, and provide a few cross pieces Do you wish to give comfort to your pet canary? Make one of these awn- ings for him for support. Cover the frame so made with a suitable covering and the shade is complete. For convenience, the upper part of the frame is provided with a small hook made by bending the extreme ends of the wires in the proper shape so that they will fit easily over the upper horizontal wires of the cage. Then the shade can be removed when it is not needed.—E. BADE. Popular Science Month! Statement of the Ownership, Management, Circulation etc.. required by the Act of Congress of August 24, 19). of Popular Science Monthly, published monthly at New York, N. Y., for October I, 1921. State of New York, County of New York, ss. Before me, a notary public, in and for the State and county aforesaid, personally appeared O. B. Capen, who, having been duly sworn according to law, deposes and says that he is the Business Manager of the Popular Science Monthly and that the following is, to the best of his knowledge and belief, a true statement of the ownership, management, etc., of the aforesaid publica- tion for the date shown in the above caption, required |); the Act of August 24, 1912, embodied in section 445, Postal Laws and Regulations, printed on the reverse of this form, to wit: 1. That the names and addresses of the publisher, editor, managing editor, and business managers are: Pi}. lisher, The Modern Publishing Company, Inc., 225 West Thirty-ninth Street, New York, N. Y. Editor, Waldemar Kaempffert, 225 West Thirty-ninth Street, New York N. Y. Managing Editor, Waldemar Kaempffert, 225 W est Thirty-ninth Street, New York, N. Y. Business Manaver O. B. Capen, 225 West Thirty-ninth Street, New York N. Y. 2.—That the owners are: The. Popular Sci Publishing Company, Inc., 225 West Thirty-ninth St: New York, N. Y. Stockholders of Popular Science Pi). lishing Company, Inc., Henry J. Fisher, 22 William Street New York, N. Y.; Oliver B. Capen, 225 West ‘Thirty-ninth Street,New York, N. Y.; Robert Cade Wilson, 683 Spring field Avenue, Summit, N. J.; Waldemar Kaempffert, 225 West Thirty-ninth Street, New York, N. Y.; George B. Agnew, 22 William Street, New York, N. Y.; Susan D. Biiss 22 William Street, New York, N. Y. 3.—That the known bondholders, mortgagees, and other security holders owning or holding 1 per cent. or more of total amount of bonds mortgages, or other securities are: Importers and Traders National Bank, 247 Broadway, New York, N. Y.: H. J. Fisher, 22 William Street, New York, N. Y 4.—That the two paragraphs next above, giving the names of the owners stockholders, and security holders, if any, contain not only the list of stockholders and security holders as they appear upon the books of the company, but also, in cases where the stockholder or security holder appears upon the books of the company as trustee or in any other fiduciary relation the name of the person or corporation for whom s trustee is acting, is given; also that the said two paragraphs contain statements embracing affiant’s full knowledge and belief as to the circumstances and conditions under which stockholders and security holders who do not appear upon the books of the company as trustees, hold stock and securities in a capacity other than that of a bona fide owner; and this affiant has no reason to believe that any other person, association, or corporation has any interest direct or indirect in the said stock, bonds, or other securities than as so stated by him. (Signed) O. B. CAPEN, Business Manager. Sworn to and subscribed before me this 21st day of March, 1921. Arthur A. Blauvelt, Queens County—2767, New York County—639, New York Reg. 1612. (Seal.) My commission expires March 30, 1921. Blank Cartridge Pistol REVOLVER STYLE PRICES 50c & $1.00 Post. Paic t Well made and ef- fective Pistol model!- led on the pattern of the latest type of Re- volver; appearance alone is enough to scare a burglar. When loaded it may prove just as effective as a real revolver without danger to life. Takes 9% standard .22 Calibre Blank Cartridges obtain- able everywhere. Even the most timid per- * son can use it with perfect safety. A Great May Protection inst Burgiars, Tramps and Dogs. You can have it lying about without the nee yoy to other revolvers. PRICE ONLY SOc ier make and superior quality for $1.00, Postpaid. Blank Cartridges .22 Calibre, (by express) SOc per 100. JOHNSON SMITH & COMPANY 3224 N. Halsted Street, Dept. 346 CHICAGO We Pay $10 a Day taking orders for Music Chest Something new. A marvelous invention. Does more than ma- chines costing 20 times its pri Easily carried with you any- where, Light and well built Gratz Made $394 a Week JOST earned over $7285 in six months. We paid TED GNA! $4455 for five months’ work | Easy to take orders on wap count of low price. $8 a da for spare time. Big opport nity forthe right men. Send for terms—Free sample THOMAS MFG. CO., Chest 247, DAYTON, OHIO Wational College “eaves.” of Chiropractic A> (RESIDENTIAL 16 N. Ashland Blvd. Chicago Unsurpassed facilities for a com- plete Scientifie Chiropractic edu- cation. Distinguished Faculty. Modern and extensive laboratory uipment. Large clinic. ymnasium dormitory and students’ aid dept. Chicago's op- portunity for self help unlimited. Enter F quarterly. 3-year term. 14th Year rade V % 60% SAVE 25% to 0 on slightly used 4 ™ > > 4 Yr rc eo GRAFLEX-KODAKS °9 Cameras and Lenses of every description. Equal to new. Save money. Write now for Free Bargain Book and Catalog listing hundreds of money-saving bargains ins|ight: ly used and new cameras and supplies All oods sold on 10 days’ Free Trial. Money ack if not satisfied. ou_ take no chances dealing with us. We have been in the photo graphic business over 19 years. Write now- 98 CENTRAL CAMERA CO., Dept. 66, 124 S. Wabash Ave., Chicage Jun r Ts cl inste learn The « and pulle abou peate must hand Th shows body back throv being the e A body miss 1 curve show: use a At wi thi allow Smoo piece For 1/16 i yond wire is The a semi more revolv Here of the tion o! is sh¢ back forme motio: wire s knee j, center joint p right o locatio in the. end of It is

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eee Oo Oo Ss ription. now for atalog in slight: es. Al . Money chances e photo now: Chicage June, 1921 The Rope-Climber—an Interesting Toy T= cord-climber is similar to the climbing monkey, only he goes by lifts instead of a constant run, and he hasn’t learned how to climb down by himself. The cord is suspended from a nail or hook, and when the cord below the model is pulled, he stretches himself, measuring about 2 in. at a pull. This operation is re- peated until he reaches the top, when he must be forcibly pulled down the string by hand. The figure at the bottom of the page shows the detail and dimensions of the body portion. There is a_ spring-stee! backbone to this figure that is used to throw the legs forward and upward after being released from the downward pull on the cord. A sawcut is made in the back of the body portion in such manner as to just miss the head, and extends well around the curve at the lower part of the body, as shown by dotted line in Fig. 1. It is wéll to use a saw that makes a wide cut so as to At the left the rope-climber is shown with the string taut; at the right, with the string loose allow room for the movement of the spring. Smooth the inside of the cut with a folded piece of medium coarse sandpaper. For the spring a good grade of steel wire, 1/16 in. in diameter and not tempered be- yond cold bending, should be used. The wire is bent as shown in the diagram. The two leg pieces from hip to knee have a semicircle at each end, the knee being the more important, as the lower leg is to revolve about this. The radius at the Here the detail of the construc- tion of the figure = is shown. The backbone is ‘i formed by the nl motion - giving rr] wire spring me + Pct Same knee is 14 in. and the joint-pin is in the center of the semicircle, but at the hip the joint pin is about 3/16 in. above and to the right of the center of the semicircle. The location of the leg pin in the body piece is in the center of the semicircle at the lower end of the body. It is well to fasten a little block some- yr Draftsman’s Y Complete Outfit Sent You Free Outfit as illustrated includes ‘‘profes- sional’’ set of fine drawing instruments in velvet lined case and all other Comes with course FREE needs. Famous School Guarantees Training The Coyne Home Study course guarantees to train you. The Coyne Trade and Engineering Schools is the largest institution of its kind in the world. Stu- dents come from all over the world to get Coyne training because of the Coyne schools’ long estab- lished, tremendous reputation. Coyne originated the “Learn by Doing’’ method now endorsed by educators everywhere. Write for the Coyne free book. . Some Coyne students took good positi 3 be- fore their course was finished. Send for FREE Book Mail this coupon for book that tells all about draftsman- ship and draftsman’s work and pay. Shows you how to become a draftsman in the quickest and easiest way. 3 Months Home yen at Study School If Dept. Preferred TRADE AND ENGINEERING SCHOOLS Largest Institution of Its Kind in the World 39-51 East Illinois Street, Dept. A178, Chicago, Ill. Learn Drafting atHome Draftsmen Make $200 a Month and Up Draftsmen get good pay from very the start and can work up to $500 a month and more. Coyne training makes everything easy. Coyne student L. T. Dubendorf writes: ‘‘Immediately after completin: Coyne course | went to work for Armour & Co. Work was easy for me, Five months later I accepted a , Position in New York at a large increase in salary.’ Coyne Trade and Engineering Schools Dept. A178, 39-51 E. Mlinois St., Chicago, Ill. Dear Sirs—Please send me free and without obliga- tion, your book on Drafting. I am interested in (chee k which one) 0) Home Study Course (© School Course NAME ....csccccscccccccccccccccccce.covsesseesessssesese Address..... PPTTTTTTTTTTITTT TTT TTT TTiT Titi eee ccvccceccccccccccccccsceecocces ccc tSeBocce Other types down to $3.50. Famous, sure fit, Kut ¢ 40 life size patterns and simple instructions show ed Act You can easily convert your Ford into this fast, saucy speedster as hundreds have done with a few dollars worth of material from the The “*Pal’”’ hardware store. No need to lay up ear. Built low, rides’ wonderfully easy. The eee Class: *Pal’’ with disc wheel Up to the minute Hit rns only $6.40 When ordered from this ad. we will send Free Pressed Metal Stream- line Rear vee makes fine finish coin brings illustrated pros pectus. MAKE FORD !NT0 SPORT CAR Patterns| SS = SS WAV S& SSS UNSIGHTLY iH) KUEMPEL COMPANY. 206 Kuempel Bidg., Guttenberg, lowa The Perfect Leg Forms i "BOWLEGSandKNOCK- KNEES” / SEND FOR BOOKLET SHOWING PHOTOS y PERFECT SALES CO. 140 W.Mayfield Ave., Dept. 45, Chicago, Ill. AUTO OWNERS Save half of your tire cost by using Double-Mileage, Double-Tread Tires, Guaranteed 6000 Miles. We lead, others try to follow. They are reconstructed of highest grade material — hardly ever blow out. They are only guaranteed for rt ons Tt) 9 Ll C Feat 6000 miles, but have run from 8000 a2 to 10,000 miles. Order today at ig these low prices: i Tubes ore RELINER FREE WITH EVERY TIRE Send $2.00 deposit with each tire ordered, balance Cc. 0. D. Tires shipped subject to your examination. State whethe r S. S. or Cl., plain or non-skid is desired. All same price. By sending full amount with order you cap save per cent—our special cash-with-order discount. DOUBLE MILEAGE TIRE & RUBBER CO. 2035 W.Harrison St., Dept.102, CHICAGO, ILL. Jobs may come, and Jobs may go, but TIRE RE- PAIRING goes on FOREVER. Another Tire Famine is Already Imminent 1921 will be biggest year of all. 10 Mil- lion car owners “will keep 20,000 repair men humping to keep up. Thousands more experienced men are needed. $250 per week in clear profits is a small income in this business. The Largest Tire Repair Organization in the World, with schools in many cities. May have one nearer to you. WESTERN RUBBER MOLD CO., 313-323 N. Crawford Ave., LEARN TIRE REPAIRING | In Our FREE Schools 243 N. Crawford Avenue 3763 Woodward Avenue, , Chicago, Illinois Detroit, Mich. 13 N. Summit Street, Akron, Ohio 1930 Grand Avenue, Kansas City, Mo 50 others in different parts of the country. Write at once to address below for cata- logs of the most up-to-date repair plants manufactured and vital information on Tire Repairing, and address of school nearest you, CHICAGO, ILL. 99

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Earn $2500 to Signal Enginee Qualify at home in spare time for a big position as Signal Engineer. Get into this great new field of fascinating work where quick success, swift promotion and a high salary await you. Rail- roads everywhere need men who - = understand Signal Engineering and electrical safety devices. Book FREE Send quick for big illustrated Book on Signal Engineering and details of our great Free Outfit Offer and our wonder- ful system of training which includes a Complete Course in Practical Electricity and Mechanical Drafting. _ Send postal to day. Don’t delay! Get it now! DEPARTMENT OF SIGNALING, Dept. A-120 1924 Sunnyside Ave., Chicago, Ill.

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where between the legs, Fig. D, to give more rigidity, and to make them move as one. The lower part of the leg is attached to the upper by means of a thin sheet-metal insert. Each arm is in one piece, has no move- ment at all, and no joint at shoulder or elbow. A small block, Fig. 1H, with a hole, through which the cord passes, is fastened between the feet. Another block F, is secured between the hands. A screw passes through one hand and block, but it is threaded to the opposite hand, which makes a clamp of the device. The block is sawn apart and little grooves are:cut in both sides to receive the cord. The crease must not be large enough to prevent the clamping of the cord or it will be useless. The clamping causes friction on the cord that prevents the climber from slipping backward. A twenty-four-ply seine twine is excellent for the cord. If the crease wears, a turn of the screw will tighten the clamp. A pin, Fig. 1G, is necessary to catch the end of the spring when the leg is drawn down while climbing. When the toy is operated, the extension draws the string down through the clamp, F. Then the legs are released and spring back. The spring holds them until the slack is taken up in the string and the figure is straightened again. Hanging the Typewriter in a Swing TYPEWRITER that is used in the . home or boarding-house should be as silent as possible in order not to disturb others. Recognizing this, the writer, who lives under the handicaps imposed by a

When suspended in this manner be- tween little blocks of wood your type- writer will not disturb your neighbors boarding-house, tried out the various rubber and felt pads on the market but found they only lessened the noise to a slight degree. So, under the spur of neces- sity, he devised a simple contrivance that answered the same purpose much better. The construction is simple in the ex- treme. The table is small with a top about 15 in. square. Four wooden blocks about 1 in. high are nailed to the table as illus- trated. Over these blocks strips of heavy flannel are spread and drawn taut and then tacked to the blocks. Care should be taken to have the feet of the typewriter resting in the center of the strips of flannel. You will find that the carriage of the typewriter can be moved back and forth without in any way disturbing the ma- chine.—H. FOWLER GOODWIN. 100 DAYTON AIRLESS This tire can’t puncture, can’t blow out. No tube—no pumping—no delays. 100,000 satisfied users. Made for passenger and delivery cars. 30x3, 30x34 and 31x4 inch size. Greater Mileage—Easier Riding New improvements hay doubled itseasy-riding qualiti:

expense. Prevent troubl Write for booklet and pricelist. Dealers wanted in every city ar county. Big Profits, No competiti Write at once for dealer proposition. The Dayton Airless Tire Co. Dept. 267 Dayton, Ohio JEW

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d to the second, chronism. Encased at factory into your choice of the exquisite new watch cases. The great Burling- ton watch sent on request. Pay at F rate of $5.00 a month. You pay only o Bottom prive! —the lowest price at oi a which the Bur ie sold. a . See color illustra- Write Today Gres ctaliperei 3 in ches tha’ ave ehoose from. Nam dress on ufacture—adjus

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3022 from 44 Styles, colors @nd_ sizes, famous Ranger See een eaten ak Resterd Prices. Save $10 to $25 on your bicycle. Immediate JQMonthsto session on our poral Easy Payment plan, Parents ften advance first deposit. Energetic boys : the small monthly payments thereafter. 3 Horns. wheels, lamps, parts and ares equipment at half usual D ° SEND NO MONEY—Ask for big free Ranger Cat . elous prices and terms. Mead Cycle Company Fz" Dept.M109 Chicago ajcnte Wh 7 yy continue to Send for (free) illustrated 200-page book. It tellg how Stammering and Stuttering can be quickly cured by the most Advanced Scientific Method in the wor!d. & a. THE LEWIS SCHOOL, 56 Adelaide, Detroit, Mict

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June, 1921 IO BrAtica Is Yours for the Asking Ese £ \ %& aS No. 5 Keep It 10 Days Free Wear a LIZNITE GEM RING and be the envy of your friends. See if you can tell it from a high priced diamond Rend sour Beme. d and Num ber of ou select, and one ‘of ese Wi trfol LIZNITE, GEM RINGS, with all the fire an ENITE & of the finest will be sent you by return mail. set weight LIZNITE GEM. Select the one you like best: No. 1—$21.50 2—$17.50 8—$15.50 No. 4— 15.50 6— 12.50 Size must be included when ordering. When your ag 7 GEM RING comes, mor paid.“ Mone back any time eee isis until Pai von Ao Geta sions me a Ring 7 Today THE LIZNITE GEM COMPANY **The House of Quality and Price’’ 611 — 128 N, Wells St.,Chicago, Ill. -. Pip hiaycle yak te Ne soya or . good sol: nod This. aoe ful wand with 18 exclusive features — From Factory to You— FREE We'll ship on approval — id, || Look the wheel over Ste ar aeneaan. 7 You're sure to be enthusiastic when you see ihe + in 1921 Model Electrically Equipped BIACK BEAUTY Our direct-from-f: : seal depot tnd A DOLLAR A WEEK tee heel & yours with the first payment. Don't delay—write now. HAVERFORD CYCLE COMPANY Dept. 386 , (Est. 25 years) Philadelphia, Pa. ~ Be a Black Beauty Owner Agent SEXUAL KNOWLEDGE ILLUSTRATED By WINFIELD SCOTT Sal. wou SEX FACTS M PLAIN What every young ry and Every young woman shou!d know $1.0( 00 Whatevery young husband and —— Every young wife should know pai What every parent should know ) frosts aid Cloth binding — 320 pages—many illustrations wrapper of tions, on request. AMERICAN PUB. CO.., 617 Winston Bldg., Philadelphia “Lighting Fixtures” ighting Fixtures fh f Ready to hang. Direct from manufacturers. Completely wired including glass- ware. Send for Catalogue No. 20 + i ERIE FIXTURE SUPPLY CO. , fis, « Desk A, Erie, Pa. iy Are want one exclusive repre- sentative in cach locality to use 7 end sell the new Mellinger Extra-Ply, hand made tires. Guarantee Bond for 8000 Miles. (No jo peconds). Shi ed pre- Va — on approval. ja sections furnished - Dor rot ay until you ret our “yg whet Direct Prices. Write pe MELLINGER TIRE & RUBBER CO, a 1004 Oak St., Kansas City, I hese five different keys are the only set of its kind to sure your safety and serve for emergencies. They pen and test thousands of different door and padlocks. When you are away or asleep how safe is your lock? ry should you lose your keys cun others open? It’s better to know than worry or be sorry. Don’t delay; only, $1,00 fur complete set VIS. with novel key chain. MASTER KEY CO. #8 ¥arhstise SHE =, * MILWAUKEE, WIS. sell F R IN. POP-~CORN | & BIG MONEY CRISPETTES FIED ‘ rams etc. | few Meisner, $250 in one day. ye in- | 3, Shook, $311 one day Sept. 1920. Piling k Erwins boy (going to school) makes $35 every Sat afternoon. - Erwin says $6 yields $25. ) No theory! Noguesswork! ° Actual proven record of successes. Send for booklet. oe Long Eakins Co., g47 High St., Springfield, Ohie A Support for a Hanging Fern-Basket LEARLY shown in the accompanying drawing are the construction and use of this hanging-basket support. It is suit- able for a sunny corner of the house in the wintertime and may be used on the porch or lawn in the summertime. Because of its natural beauty and com- parative inexpensiveness, yellow pine is the With little trouble you may make one of these supports for a hanging basket best material to use. First shape out the sides A and the rail C, and fasten them together with glue and concealed nails. The base bridges with their blocks are next made and screwed together. The diagram shows how the upright pieces and base are joined. The three-cornered blocks D are screwed to the lowest part of the edges of the uprights, as in Fig. 3. For finish, fill with shellac or varnish and stain light mottled green or weathered oak. This is followed by two coats of wax or varnish rubbed dull.—H. ADLON. Describing a Movable and Revolving Pipe-Rest OME days ago, while in a machine- shop, I noticed a pipe-rest, evidently made in the shop, for supperting pipe while the pipe was being cut in a machine using a saw-blade (working horizontally) as a La --- fy = / WROUGHT IRON PIPE PEDESTAL OLD PUMP —~ BASE In shops where pipes or long rods of metal are frequently handled, the pipe-rest here shown will be very useful cutter. As the rest was not attached to the floor, it could be placed at a distance to accommodate various lengths of pipe. The spool had previously been turned in a lathe.—JAMES M. KANE. 101 oe Learn Drafting Employers everywhere are looking for skilled draftsmen. ‘They are offering good salaries to start with splendid chance for advancement. Drafting offers exceptional opportu- nities to a young man because drafting itself not only commands good pay, but it is the first step toward success in Mechanical or Structural Engineering or Architecture. And drafting is just the kind of work a boy likes to do. ‘There is an easy delightful way in which you can learn right at home in spare time. For 29 years the Inter- national Correspondence Schools have been giving boys just the training they need for success in Drafting and more ‘than 200 other subjects. “Uhousands of boys have stepped into good positions through I. C. S. help, but never were opportunities so great as now. Let the I. C. S. help you. Choose the work you like best in the coupon, then mark and mail it. ‘This doesn’t obligate you in the least and will bring you information that may start you on a successful career. ‘This is your chance. Don’t let it slip by. Mark and mail this coupon now. TEAR OUT HERE — ——— ow INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7627-B SCRANTON, PA. Explain, a obligating me, how I can qualify for the position, or in the subject, before which I mark X. ELEOCTRIOAL ENGINEER SALESMANSHIP Electric Lighting and Kys. ADVERTISING Electric Wiring Window Trimmer Telegraph Engineer Show Card and Sign Ptg. Telephone Work — Railroad Positions MEOHANIOAL ENGINEER ILLUSTRATING Cartooning BUSINESS MANAGEMENT —— 8 Corresy usiness Peat Oondent BOOKKEEPER e | atm and Typist Cert. Pub. Accountant TRAFFIC MANAGER Railway Accountant Commercial Law — ENGLISH on aeons eee CiviL SERVICE Railway Mall Clerk AUTOMOBILES Mathematics Navigation [asete AGRICULTURE Teacher Poultry Raising Banking Mechanical Draftsman Machine Shop Practice Toolmaker Gas Engine Operating CIVIL ENGINEER Surveying and Mapping MINE FOREMAN or ENGR STATIONARY ENGINEER Marine Engineer Ship Draftsman ARCHITECT Contractor and Builder (LJarchitectural Drafteman Concrete Builder Structural Engineer () PLUMBING AND HEATING Sheet Metal Worker Textile Overseer or Supt. OHEMIST Pharmacy Write name and address here Name Present Business 2-1-20 Occupation Address = — Street and No. = City State Canadians may send this coupon to International Corre- spondence Schools Canadian, Limited, Montreal, Canada

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P will give our opinion as to its patentable nature. RANDOLPH & CO. 130 F St, N. W., Washington, D. C. IF YOU HAVE AN AT Ss Re! T & INVENTION and DESIRE SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent Free on request. Tells our Terms, Methods, etc. Send model or sketch and description of your invention and we pote eee --- -- TO LEARN HOW TO PATENTS Booklet Free Highest References Promptness Assured Best Results Send drawing or model for preliminary examination of Patent Office records and report as to patentability All Business Given Prompt and Proper Attention WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D. C. = Book onPATENTS Contains valuable information and advice to inventors on securing Patents. Send model or sketch of your invention for Free Opinion of its patentable nature. Prompt service. 20 years experience. Write today. TALBERT & TALBERT 4911 TALBERT BLDG.,Washington,D.C ‘PATENTS Send us sketch or model for patentability : opinion and exact cost of patent. Our book mam ‘How to Obtain a Patent” Sent Free on re- maquest. It tells how to apply for Patents, Trade Marks, Foreign Patents, Copyrights, etc.; gives information on Patent Procedure; tells what every inventor should know. Thousands of Inventors, who are our clients, are our references. CHANDLEE & CHANDLEE, 25 Years‘ Experience 425 7th St. Washington, D. C. ARMATURE AND MAGNET WINDING By Horstman & Tousley A necessary book for electricians. Full facts and dia grams, $1.75 post paid ee ie POR DON’T LOSE YOUR RIGHTS TO PATENT PROTECTION M §€©6 Before disclosing your invention to anyone send for blank form *tEVIDENCE OF CON- CEPTION” to be signed and witnessed. | sample form together with printed instructions i will show youjust how to work up your evi- dence and establish thesame before filing ap- plication for patent. As registered patent at- MW torneys we represent hundreds of inventors all B over the United States and_Canada in the ad- vancement of inventions. Ourschedule of fees willbe found reasonable. The form “Evidence } of Conception,” sample, instructions relating to obtaining of patents and schedule of fees sent upon request. Ask for them,—a post card will do. PATENTS ANDO TA TRADE MARKS ating Nl 274 Ouray Bidg. WASHINGTON, D. C. Originators of forms ‘Evidence of Con ception.” T— a] | She Bok DATENTSENSE : for | Inventors and Manufacturers Sixth Eornion By return mail FREE. Write LACEY @ LACEY Ghe Book for INVENTORS-~= Dept. Washing tan. DC PATENTS Secured Prompt Service. Avoid dangerous delays Send for our “Record of Invention” form and Free Book telling How to Obtain a Patent. Send sketch or model for examina- tion. Preliminary advice without charge. Highest references. Write TODAY. J. L Jackson & Co., 169 Ouray Bldg., Washington. D. C. PATENTS TRADE-MARKS COPYRIGHTS Send for our free book of patent information 804 F St., Washingt D..c Beale & Park 25. Sj¥tinnen,2. ¢ Popular Science Monthly, 225 W. 39th St., New York | Cat ont this ad and mail it to us, with your name and address (no money); and we will send you our FAMOUS KARNAK RAZOR by return mail, postpaid. You may use the razor for 30 days FREE; then if you like it, pay us $1.85. If you don’tlikeit return it. SEND NO MONEY. MORE COMPANY, Dept. 397 St. Louis, Mo. (i To the Man With an Idea ‘ } I offer a most comprehensive, ex- | perienced, efiicient service for his | } ; “4 prompt, legal protection and the | 4 development of his proposition. || ek * : Send sketch, or model and description, i for advice as to cost, search through j 24 prior United States patents, etc. Pre- |} iy liminary advice gladly furnished with- | = out charge. t 3 My. experience and familiarity with Ps various arts, frequently enable me to accurately advise clientsasto probable | patentability before they go to any expense } Booklet of valuable information and form for properly disclosing your idea, free on request. Write today. 4 RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington,D.C. 2276-D Woolworth Building, \ New York City a ©. end * - Ce Sat hace Popular Science Monthly How to Keep Chickens in Their Yard HICKENS can be kept in their pen hb) nailing two-foot slats at an angle t, the posts and stringing a number oj strands of thin wire through them as show: in the drawing. The chickens do not sec WN a * as Wires stretched as shown here will effectively prevent chickens from wan- dering into the neighbors’ yards these wires and when they attempt to fly over the fence, they strike the wires and fall back into their yard. After a number of futile attempts, they will not try to fly over again.—E, BADE. A Form for Molding a Concrete Trough FOOD trough for pigs is readily made from concrete, using for a form a semicircular section of log and rectangular box made with nailed planks as shown in the appended illustration. A log of the desired capacity of the trough is selected and this is split length- wise, placed face down on any flat barn or other floor, the outer casing is placed over CONCRETE OUTER FORM BEVELED ENDS SSS SS SIDE VIEW One half of a beveled log and a wooden frame is all that is required for casting a concrete trough this and secured with two nails to prevent it from shifting while the cement is poured. A coat of axle grease is smeared over the surfaces of the wood to prevent the con- crete from sticking. After pouring, the cement it is allowed to set for several days. This makes a trough that is practically in- destructible and is not readily upset. Simi- larly, troughs for cattle, chickens, etc., may be made of any desired size.—G. A. LUERS. IS he me for tio dis ac a |; mc Fig rol mc the roc wil she of 1 Ox cf ALTA type an a A in F will mak lengt com) be t be d be fr Exac filed front Care a pel shou! mate size ¢ lathe This upon PoOssi throu inser from slight the ¢ Way | taper

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de lar in the en ag event yured. er the > con- gy, the days. lly in- Simi- ., may 4UERS. June, 1921 Drills for Boring Deep Holes in Metal HEN the amateur mechanic has an extra deep hole to drill in metal that is beyond the capacity of an ordinary drill, he is at a loss just how to proceed. Few mechanics know that they can make a drill for this work very easily. The drills men- tioned in this article will drill holes of small diameter to a depth of 10 in. with perfect accuracy, providing they are used only on a lathe. For holes of large diameter, 14 in. or more, the type of special drill shown in Fig. 1 will be found satisfactory. The cold- rolled rod upon which the cutting edge is mounted should be about 4 in. longer than the hole to be drilled. One quarter of the rod is then cut away as illustrated. This will have to be done in a machine-shop if a shaper is not at hand. Exactly one quarter of the rod should be cut away. A cutter of the shape shown is then cut from tool steel. This is ground true and the cutting lip sharpened. The piece is then hardened. Before the hardening, two holes should be drilled for the ho!ding-down screws, which should be countersunk. A recess is cut in the cold-rolled rod so that the cutter will come flush with the surface. The cutting edge is ground at a slight angle so that it will gradually incline outward from the center. When using this COLD ROLLED Cees, HOLE MARDENED CUTTER -FILED FLAT CUTTING EDGE HOLE FOR PIN ~ \ worr TOOL- STEEL ROD FIG.2. FIG.3 Several tyres of special drills for boring deep holes are here shown. Learn how to make them in your own shop type of drill, it is best to start the hole with an ordinary drill. A simpler type of deep drill is illustrated in Fig. 2. This is used for small holes and will be found very efficient and easy to make. The cutter is made from a short length of tool-steel rod. This material is commonly called drill rod. The rod should be the same size as the hole that is to be drilled. The length of the rod should be from 4 to 6 in., depending upon the size. Exactly half of it, for a distance of 2 in., is filed away and a slight angle is filed on the front of the cutting edge. Considerable care must be exercised in this filing so that a perfectly flat surface is produced. Care should also be taken that exactly half the material is filed away, as this influences the size of the hole. The piece is now put ina lathe and drilled out for a distance of 3 in. This hole is to receive a cold-rolled rod upon which the cutter is mounted. One, or possibly two holes, should be drilled through the center of the rod and pins inserted. This will prevent the cutter from turning while the device isin use. A slight flat should be filed along the top of the cutter to allow the chips to find their way out. The shank of the tool should be tapered off about .002 in. When all this «) TRADE-MARKS COPYRIGHTS PATENTS comic : SP ECIAL OFFE PATENT ABLE NATURE Before disclosing an invention, the inventor should write for our blank form ‘‘Evidence of Conception.’”’ This should be signed and witnessed and if returned to us to- gether with model or sketch and description of the inven- tion, we will give our opinion as to its patentable nature. Our Three Books Mailed Free to Inventors Our Illustrated Guide BOOK HOW TOOBTAIN A PATENT Sent FREE on Request Contains full instructions regarding Patents, Trade-Marks, Foreign Patents. Our Methods, Terms, and 100 Mechanical Move- ments ‘Hustrated and described, Articles on Patent Practice and Procedure, and Law Points for inventors. OUR TRADE MARK BOOK Shows the value and necessity of Trade-Mark Protection and gives information regarding unfair competition. OUR FOREIGN BOOK We have Direct Agencies in all Foreign Countries. Write for our illustrated Guide Book on Foreign Patents. SPECIALIZATION Our Staff The field of invention is so vast that it is impossible for any one man to become an expert in all the different classes of invention. Only those practically skilled in the class to which the invention relates are capable of rendering efficient service. For this reason Victor J. Evans & Co. employ a number of patent lawyers and mechanical experts who have been selected for their special knowledge and ability in certain lines of invention. Each case is placed in charge of experts in the classes in which the invention relates. THE VALUE OF YOUR PATENT Will depend much upon the skill and care with which deg den ase is prosecuted in the United States Patent Office. This work will receive the benefit of skill and experi- ence acquired by a long and successful practice. We spare neither time nor pains to secure the broadest possible patents that the inventions will warrant. That every case entrusted to us receives our best efforts, and that our work is done consistently, skillfully and thoroughly is evidenced by the many unsolicited letters of commenda- tion that we receive constantly from our clients. We will furnish upon request lists of clients from any State in the Union for whom we have secured patents. Our New York, Philadelphia, Pittsburgh, Chicago, and San Francisco Offices Owing to the growth of our business we have established for the benefit of our clients Branch Offices in New York City, Philadelphia, Pa., Pittsburgh, Pa., Chicago, Ill., and San Francisco, Cal. These branch offices being located i in these large comme rcial citie s, together with our Main Office located near the U. S. Patent office, in Washington, enables us to more promptly handle the business of our clients, particularly as the branch offices are in constant touch with the Main Office and fully equipped to handle patent business in all its branches. Highest References—Prompt Attention— Reasonable Terms ae eee Gai] VICTOR J. EVANS & CO. Patent Attorneys New York Offic Philadelphia Offices Pittsburgh Offices | 1007 Woolworth Bldg. 135 S. Broad Street 514 Empire Bldg. Chicago Offices, 1114 Tacoma Bldg. San Francisco Offices, Hobart Bldg. Lay Main Offices, 760 9th Street, Washington, D.C. | Ul Gentlemen: Please send me FREE OF CHARGE your books Tw as described above. | \ nl ac dys Address. . 103 EULA

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PATENTS F YOU HAVE AN INVENTION which you wish to patent you can write fully and freely to Munn & Co. for advice in regard to the best. way of obtaining protection. Please send sketches or a model of your invention and a description of the device, explain- ing its operation. All communications are strictly confi- dential. Our vast practice, extending over a period of seventy years, enables us in many cases to advise in regard to patentability without any expense to the client. Our Hand-Book on Patents is sent free on request. This explains our methods, terms, etc., in regard to Patents, Trade Marks, Foreign Patents, etc. If you are a reader of SCIENTIFIC AMERICAN you are probably aware of the fact that it has a special appeal to the inventor. Each issue contains a description of a large number of recently pat- ented inventions. Pending pat- ent legislation as well as the most recent rulings of the Patent Office and the courts are considered in its columns. MUNN & CO. SOLICITORS OF PATENTS 683 Woolworth Building, New York 624 F Street, Washington, D. C. Tower Building - Chicago, IIl. Hobart Bldg., 582 Market Street, San Francisco, Calif. Y think of a simple, practical idea that will fill one of the many re- quests we have on file for new inven- tions? It may mean a fortune for you. Thousands of things are needed RiGut Now. Your brainscan help. Send to- day for our great new book—*‘Invene tions and Trade Marks, Their Protection and _ Exploitation’’ and learn more about making money from ideas than you ever knew before. It tells many things that are wanted, t00. A postal will do— it is free. work is finished, the center should be hardened and tempered. It is then ready for work. Its action is shown in Fig. 3. When the D-bit is used in a lathe, a special handle must be made to accommo- date it. Such a handle is shown in Fig. 4. It should fit in the tool-post of the lathe. A piece of cold-rolled flat stock is used. About 6 in. of this will suffice and one end is slotted for 2 in. with a hacksaw. Before the slot is cut, a hole is drilled to accommo- date the drill. Care should be taken that this hole is perfectly accurate. When the sawing is done, another hole is drilled through to accommodate the clamping- nut. One half of this hole is drilled out to make a clearance for the bolt. When the bolt is tightened, it will pull the holder together and hold the rod tightly. When the tool is used, the back center of the lathe should be brought in contact with the free end of the drill. This type of tool is very slow in its cutting and should not be forced too much. Lubricating oil or cut- ting compound should be applied liberally and the tool should be withdrawn at regular intervals to bring out the chips. An Extra Chuck to Hold Small Drills N extra chuck for small drills to be used in an ordinary carpenter’s brace can be made as follows: Procure a piece of good tool-steel about 5/16 in. in diameter and 2 in. long. Drill ly-in. hole lengthwise through the center of the piece. Then, witha hacksaw, cut a slot down the center to within 14 in. of the end, as shown in the illustration. This chuck can be used in a car- penter’s brace or any other form of chuck and, owing to the spring of the slot- ted ends, it will grip various sizes of drills. DRILL FIOLE This chuck is useful for holding drills How to Enclose Stamps in a Letter EVER stick a stamp to a letter. There are at least three better ways. If you are enclosing one stamp in a letter, make two slits % in. long and 34 in. apart, then slip diagonally op- posite corners of Popular Science Monthly A Real Tin Lizzie Made from Cans \ ITH an assortment of tin cans to work with the writer made a tin can automobile that is very good looking. The hood is made of about three quarters of a large condensed-milk can, one end being left in for the front of the car. Th: seat is made of part of the remainder of th Whatever is lacking in the resem- blance of this toy to a real car will be supplied by imagination large milk-can. Behind the seat is the gasoline tank, represented by a coffee-can and lid. Each wheel is made of two sizes of lids, one fitting into the other to give solid- ity. One lid is a coffee-can lid and the other a baking-powder-can lid. Screwed to the wooden axle these lids are strong enough to serve their purpose. Even the steering-wheel is a lid with openings cut to form the spokes.—CHARLES A. GODDARD. Prolong the Life of the Window-Garden ns keep the flower-pot standing in water; it is injurious to the plant and especially to the root system. The mois- ture, when the plants are watered, should run through the root balls as quickly as possible. The roots not only require moisture, but also air, and if the saucer is full of water, and if the pot stands directly We help our clients, Without charge, to get PATENTS the stamp in the the dollars out of their ADVERTISED slits. If there are Mice otuer'soscaa”” MN For SALE FREE | | t®° stamps or above the saucer you can prolong os more to be en- the life of your flowers : In INVENTION And | | closed, make two a . / D RE MANUFACTURING slits 1 in. long and ty | in the saucer, little if any air can reach the FOR SUPPLEMENT. about 1 in. apart roots, since the soil is supersaturated with and run the string Published for the moisture. Pho gratia of stamps through. Therefore it is desirable to keep the Send for free sample When stamps flower-pot slightly above the saucer. This on tag! pada with the adhering is accomplished by taking two pieces of margin can be ob- band iron about 14 in. wide and 1/32 in. tained, leave the thick and iron 8 to 10 in. long. These are perforated margin bent with a flat-nosed pair of pliers in the LEARN AUTOS AND on and_ stick it desired shape so that it fits snugly around TRACTORS down on the paper so that the stamp can the pot and at the same time lifts the pot Wonderful opportunities constant- be torn off. et ro oh ge rea oane above the saucer, as shown in the illustra- Sees pene The very best way to enclose astampfor tion. These two pieces are bent exactly motor expert. driver, shop fore- reply is to put it on a self-addressed en- similar to each other, then they are crossed, velope. Another way to enclose stamps is and finally held in place by two U-shaped in the small drug envelopes commonly clips bent firmlyYaround the center of the 5000 graduates making good. Catalog Free. used to contain small articles. cross piece.—E. BADE. 104 By keeping the flower-pot raised Advice free. Don't delay—get the book at once. AMERICAN INDUSTRIES, INC. 201 Patent Dept., WASHINGTON, D. C. ; PIC NOTEWOR m : Ste Send to u Two methods of en- closing stamps Cleveland Automobile School, 1821 E. 24th St., Cleveland, Ohio.

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the with the This al 2? in. p are 1 the ound > pot istra- actly ssed, yaped yf the 5 46 [urn fuse Cc: June, 1921 | ASBESTOS We are miners and shippers of Crude Asbestos in any quantity. We produce all grades at our world famous BELL ASBESTOS MINES, in Canada. We also card fibres, spin yarns, weave cloths, and make all sorts of Asbestos products. For anything you want in Asbestos turn to Keasbey & Mattison Company Dept. S-4, AMBLER, PENNA., U.S. A. Owners of the World’s Largest Asbestos Mires | Cold Pipe Bending Machines Standard of the World Bends all sizes of pipe from 1 \& in. to 8 in. Hand or mo- Models tor operated. .E&F Send for Catalog Standard Pipe Bends 1” to 6” pipe, in stock for immediate delivery. AMERICAN PIPE BENDING MACHINE CO. 51 Pearl Street BOSTON, MASS. Bie & seth BS Charging Batteries SMALL CASH PAYMENT BRINGS YOU AN HB BATTERY CHARGER Almost a year to pay balance er terms. Made in sizes for 10, 16, 32 0r batteries. Choose size you need, then write for information. HOBART BROTHERS CO., 3 : Troy, Ohio F Canadian Representative | BATTERY SERVICE & SALES Co. iamilton, Ontario v Slashes Prices 2to 30 H. P. This 2 H. P. WITTE on Skids Ready to Use NOW ONLY ‘3 From Pittsburgh $5 More. 90 Day Test—Lifetime Guar- antee. SPECIAL PRICES on Larger Sizes. Write for Catalogue No. 49—FREE! 95 F.0. B. K. C. WITTE ENGINE WORKS Kansas City, Mo. ns ey Pa, 2221 Oakland, Ave. 2224 Empire Bldg. RELIABLE, STANDARD FOR YEARS ; PIONEERS IN THE NOTEWORTHY IMPROVEMENTS : Stocked by Dealers. Send to us for Catalog No. 12. Saginaw, Mich. MECHANICS The highest quality tool chests made for Machinists, Toolmakers, Carpen- ters, Electricians, Plumbers, and Auto mechanics. Ask for catalog, prices and ‘‘Satis- faction-or-Money-back’’ guarantee. UNION TOOL CHEST CO., Ine. 24 Mill St., Rochester, N. Y. Mix Concrete by Means of a Tumbling Barrel LABOR-SAVING concrete mixer that can be improvised from materials normally procurable without cost, is shown in the illustration. It consists of a tumbling barrel in which half-bag batches can be For mixing concrete in small quanti- ties this tumbling barrel will be found very useful rapidly and thoroughly mixed with the least effort and provides a means of emptying the concrete directly into the barrow without additional shoveling. The barrel is mounted on a center pivot with brace-blocks at the sides to secure this shaft member to the barrel. The barrel head is hinged at one side and a circular block made to stiffen the lid and to provide a closer-fitting cover. A quick- acting clamp is fitted at the opposite side from the hinge. The lower side of the barrel is mounted about 2 ft. above the platform, to permit of rolling the barrow SHAFT BEARING The various parts of the rocking mechanism, excepting the barrel and framework underneath for dumping. Oak blocks bolted to side braces form the mounting for the center bar. The platform under- neath is of close-fitting boards to permit. of shoveling where the sand, gravel, cement, or concrete is unavoidably spilled. The shaft extending through the center of the barrel assists in cutting and mixing the batch, as the barrel is oscillated. An Easy Way to Remove a Tight Can-Lid AN-LIDS are often difficult to remove. Here is a plan by means of which they can be loosened easily. Tie a piece of stout twine loosely just below the cover, then thrust under the twine a pencil and start to twist this. When the twine is tight, the cover of the can comes away readily. Twist string with pencil to remove the lid 105 BROWN & SHARPE MACHINISTS’ TOOLS Universal Bevel Protractor Combination Square Is it serviceable ? Will it give as good service five years from now? If a concern has supplied tools to satisfied machin- ists for three gener- ations, the answer is evident, and points out to you the tools to buy. Brown & Sharpe Machinists’ Tools We have a catalog that will interest you. Send for No. 28 BROWN & SHARPE MFG. CO. Providence, R. 1., U. S. A. Vernier — , Lf 4 : Bp “The Mark that Guarantees Quality.”

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Our New Trade .Mark! Make sure that your Home Tools are STANLEY +TOOLS OCD TOOLS make home tinkering a plea- sure; there’s a joy in “fixing things’ with them and doing creative work, not marred by unbalanced, easily dulled, imperfect tools. When your hammer is made of carefully forged special steel with perfectly balanced handle of selected white hickory—it’s a STANLEY. Ask for a “Hurwood” STANLEY Screw Driver; it’s a handy one in the home; blade, shank and head one piece of steel A STANLEY Zig Zag Rule is useful for many purposes besides carpentry. Of an especially fine finish, with joints, tips and strike plates brass plated. The head, shank and blade of STANLEY “Everlasting” Chisels are forged from one solid piece of tool steel; cut- ting edges ground sharp. A STANLEY Brace with a tew assorted Bits is a con- stant joy. No. 921 is nickel plated, with alligator jaws and ball bearing head. The BAILEY No. 5 Jack Plane is a delight to anyone who loves good tools: cut- ters adjustable both endwise and sidewise. Ask your hardware dealer to show you his line of STANLEY Tools, end write us for catalogue, 7-F THE STANLEY Rute & LEVEL PLANT. Tre Stancey Worxs New Britain, Conn. U.S.A. Finding New Uses for Old Things What use have you for some of the “junk” in the attic or cellar? Popular Science Monthly will pay ninety dollars for the best answers HERE is the old baby-carriage, the old stove. the old bureau, the trunk, and the leaky wash-boiler. The attic also contains old phonograph needles, safety-razor blades, carpets, curtains, chairs, tables, picture-frames, hat- boxes, etc. Have you been able to save money and add a convenience to your home by pressing some of these things into service again? If you have, you probably had to gct the household tool-kit out to help you. Sit right down no\ and tell Popular Science Monthly what changes you made and how you made them. It makes no difference what you changed, as long as it wasold. You may win one of the prizes. The Popular Science Monthly offers three prizes for the best answers—a first prize of $50, a second of $25, and a third of $15. the rules outlined below. These will be awarded in accordance with Rules Governing the Contest (1) Contestants are not limited to the number of ideas, but only one method can possibly win the first prize, only one the second, and only one the third. The con- test is open to everybody. (2) The use of the old piece of junk must be shown clearly, either in a photograph or in a drawing. If a drawing is sent in, it need not be made by a skilled draftsman. It is sufficient that it should be intelligible. While pen- cil sketches will be considered, contestants are requested to make their drawings in ink on heavy white paper. The views should be sufficient in number to set forth the writer’s idea very clearly. The con- testant’s name and address should appear on each sheet of drawings. (3) The drawings or _ photo- graphs must be accompanied by a description, preferably type- written, in which the method is clearly given. It must be written on one side of the paper only, and it should not be more than 500 words in length. The name and address of the contestant should appear in the upper left-hand corner of the first sheet of the written description. (4) The drawings and descrip- tion entered by contestants must be received by the Popular Science Monthly not later than 5 p. m., on June 15, 1921. (5) The judges of the contest will be the editors of the Popular Science Monthly. 106 (6) The first prize of $50 will be awarded to the contestant who, in the opinion of the judges, has suggested the best use for an old piece of junk. The second prize of $25 will be paid to the contestant who sub- mits an idea next in merit. The third prize of $15 will be paid to the contestant who sub- mits an idea third in merit. (7) The winners of the contest will be announced in the earliest possible issue of the Popular Science Monthly. A description of the ideas that win the three prizes offered will duly appear in the pages of the Popular Science Monthly, together with the names of the winners. (8) The editors of the Popular Science Monthly shall have the right to publish meritorious manu- scripts that do not win a prize. The regular space rates will be paid to the contestants who sub- mit the manuscripts thus selected. (9) When a contestant submits more than one idea, the descrip- tion and drawing by which each is set forth must be sent as a sep- arate unit. (10) Manuscripts or drawings will be returned to contestants if stamps are enclosed. (11) Send drawings and specifi- cations to the Editor of the New Uses for Old Things Contest, Pop- ular Science Monthly, 225 West 39th Street, New York City. Popular Science Monthly June, 15 No AINT have 1 poses. I frames a same frat many pi such case TOP VIEW WIRE - SCREW EYE — 7 MOLDING FRAME SIDE VIEW How a framed canvas it nails, sere easily be in the mi placing th stretching other on 1 cross that picture fir Any sl remedied screw-eye: Perfor: J VER full | edge of t opening w site edge lifting up Fluid n without Vided Points of t B ven, stear 4 milk shoul air is admi ecut. The mnilk befo shaking th

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a h in es ar he Le. be d. its ip- ch 2p- 1g8 ; if ‘ifi- ew Op- ‘est

‘Shaking the bottle.—FREDERICK C. DAVIS. June, 1921 No Nails or Screws in This Frame AINTINGS mounted on stretchers have to be framed for exhibition pur- poses. It is not always feasible to provide frames and mats for each painting. The same frame and mat may have to serve for many pictures of corresponding size. In such cases it is not desirable to fasten the

|

MOLDING L anid f FRAME (PICTURE —— 4 — SSE a a = = SIDEVIEW How a painting may be temporarily framed without the use of nails or glue

canvas in the frame permanently with nails, screws, or glue. The difficulty can easily be overcome by screwing screw-eyes in the middle of each side of the frame, placing the mat and picture in position and stretching wires from one screw-eye to the other on the opposite side, forming a wire cross that will hold the three parts of the picture firmly together. Any slackness of the wires may be remedied by giving a slight turn to the screw-eyes to which the wire is attached. Perforating the Bottle Cap Aids in Pouring A VERY easy way to pour milk from a full bottle is as follows: Near one edge of the paper cap cut a V-shaped opening with a knife, and near the oppo- site edge cut an X-shaped opening. By lifting up the point of the V, and the four

Fluid may be poured from a bottle without spilling, if the cover is pro- vided with the openings indicated }Points of the X, milk can be poured in an fven, steady stream from the bottle. The s milk should come through the V opening; : air is admitted to the bottle through the X cut. The cream may be mixed with the milk before punching the openings by

Red Dewil Pliers REG.U.S. PAT. OFF, You can depend on them! A pair of pliers is just about the handiest tool you can have in your kit. You'll use it for everything.

But you want a real plier, a comfortable one to grip, a husky one to take hold and hold fast, a powerful one to cut wire, nails, etc. A real, good, all-around plier will handle any job you need around the house, barn, garden, garage, tractor, ete. For quality’s sake, insist on a ‘‘Red Devil” Plier, the real kind. Slip -Joint Plier No. 1226 That’s just the all-around tool you need. Insured for 2 years’ service, by a signed and sealed bond. Beautifully nickel plated. Combines: Wire Cutter Flat-Nose Plier Pipe Grip Screw Driver At all good hardware dealers, or if not in stock, send $1.50 for a sample ‘Red Devil’ Plier No. 1226—7 inch size. Write today for free tool booklet SMITH & HEMENWAY CO., Inc. Manufacturers of ‘‘Red Devil’’ Tools 264 Broadway, New York, N. Y. ‘*Red Devil” Pliers are made in 100 styles—one for every need.

How to Become a Successful Electrician By Pror. T. O’CONOR SLOANE. The studies to be followed, me ‘thods of work, field of operation and the requirements of the successful electrician are pointed out and fully ex- plained. 202 pages. Illustrated. . Price, $1.50 Popular Science Monthly - 225 West 39th ‘Street, New York,

Are Found Wherever Lathes Are Used Schools and Colleges use them for instruction purposes; Automobile Man- ufacturers, Makers of Small Tools (who require work of minute accuracy), Machine Shops large and small, many other industries, even hotels and de- partment stores, are using Monarch Lathes with universal satisfaction. Monarch Lathes are built with all the late st improve ments ?

Ask your Supply House or Write for Catalog OSTER MANUFACTURING CO. East 61st Place Cleveland, Ohio

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“That door won’t stick now!” A Sargent Auto-Set Bench Plane is all that is needed to correct many such household annoyances. Every man who is handy with tools should haveone. Your hardware dealer sells Sargent Planes. He will be glad to show you the Auto-Set fea- ture which permits the blade to be put back into the same posi- tion after whetting, without re- adjustment. An exclusive Sar- gent feature. The Sargent Book of Planes will be sent free on request. SARGENT & COMPANY Hardware Manufacturers 50 Water St., New Haven, Conn.

HE wagon herein described is a ve- hicle that combines the features of a row- boat with those of a cart and, if properly made, will be a great muscle developer as well as a source of amusement. The working parts are such as to require careful construction. First, procure enough ash or other springy wood to con- struct the framework of 114 in. by 2 in. stock. Following are 2 pieces of gaspipe, each 10 in.; 2 pieces of stays, 14 in.; rest for feet—for steering, 12 in.; center piece (lengthwise), 50 in.; pieces each side of center—front to seat— 20 or 21 in.; seat to rear—12 in.; cross piece under seat, 7 in. The remainder of material needed is as follows: two pieces of oak or maple, 8 in. square; if turned separately, l-in. stock will do, but if the large wheel and the pulley are turned in one, 1% in. will be necessary. Piece of hard wood for seat 1 in. by 6 in. by 8 in., shaped to conform to drawing. Twocurved pieces on rear 114 in. by 2 in. by 3 in., shaped as shown. va 7D

B 84 \

Your boy will be delighted with one of Popular Science M onthly This Wagon Is Moved by Oars By Frank W. Vroom

j in. long. Keep this ae well oiled on inside. \ { Two l-in. Coil ee \j springs, 3 in. each nn : Bolts for pi: oting i foot-rest, oars, and q tiller. Small stove 4 bolts for joining arms ‘= on oars and pulleys “3 to iron in pipe. $ Screws—flat head—2 ~ e 7 in. long, No. 10 wire, ¥ Wood strips for join. 5 ing oars and pulleys, a. By referring to the can . drawings the con- Pa struction of the ve Og hicle will become clear. A is the front the dimensions: these rowboat wagons and will be axle of square iron, | Width across front, benefited by exercising with it in. by 50 in. Thread 4 ft.; width across the ends to receive rear, 6 in.; cross piece for oars, 20 in.; the nuts countersunk in the pulleys. B jis the pulley, turned on big wheel or separate ly. Cis the large wheel for traction. It should be rimmed with strap iron. D isa gaspipe, fastened to the frame with iron straps as shown. E is the footboard, with foot-rests cut as shown. F are the springs for holding the rear wheel to its course when going straight ahead. H is an arm of wood to fasten the oar to the main shaft. / is the oar; if greater lever- age is preferred than that specified, these may be made longer and _ pivoted nearer y theend of the frame J is the seat. K is an arm of wood con- necting the pulley with the shaft. 1 is the tiller for steer- ing the vehicle. M is the wire cable connecting the tille

One piece _ for with the foot-rest tiller or steering- N is the rear whee arm, 11% in. by 1 7 in. in diameter in. by 8 in.; two and should be set pieces for oars, 1 into the projec in. by 1 in. by 12 phmgeaenaneg ms tion of the center in.; 1 piece of )2- RINGS © $ maple 1o Piece of the frame in. round iron, 24 al PPE and in a fork di wood similar t

in. long.; 1 piece of 14-in.—inside_ di- ameter—gaspipe 6 With the aid of the top and side views here given you can easily build one of these rowboat wagons the front fork of 4 bicycle.

Mandolin, Mandola, Mando - Cello, Guitar, Tenor-Banjo, Mandolin - Banjo, P Cello-Banjo, Guitar-Banjo, Harp- y Guitar, Mando-Bass— : > i ns <5." Easy to Play Easy to Pay Select your Gibson now. “é a can soon be playing the music of the day. Your friends will be surprised and delight- fully entertained. Let us help you organize a Gibson Orchestra in your community. You can in- crease your popularity, income and pleasure by playing for Concerts, Enter- tainments, Church Affairs, etc. A small down payment and then $5 & month will soon pay for a Gibson and will fur- nish you with wholesome, year-’round entertainment. If you have an olé instrument, we will make liberal allow- ance on a Gibson. Write Today for Free Book, Catalog, Free Trial Offer, information about Wm, Place, Jr. Book and the instrument you prefer _ GIBSON MANDOLIN-eGUITAR OO.

Pencil-Tips for Splicing a Fishing-Rod of the thin sections of a fishing- No duplicate of the NE rod was broken. part being obtainable, I decided to mend BREAK the break. I cut off the rubber- holding brass tip of two lead-pen- cils, of which one

was. slightly smaller than the other, and_ re-

moved the wood and lead in them. Iforcedthelarger —-=<=

of the tips on the Las mani = thicker part of FIGS the broken sec- Brass tips of pencils tion and the 4 hold together the parts

486 Parsons &t., Kalamazoo, Mich., U. 8. A.

of the broken rod 108 smaller tip on the thinner section, as shown in the illustre tion. Then I shellacked the surface d the break and pressed the two _ parts together. The two metal tips clamped the cemented parts together, holding them it place and strengthening what would other wise have been a weak spot. The repaired section of the rod was coated with shellac prevent the tips’ slipping.—J. M. KANE. How to Bend Brass and Copper Tubing HEN small tubes of brass or coppé or steel are to be bent, they have? tendency to flatten out at the curve. Sma tubes can be bent without flattening if the! are first filled with molten resin. Large tubes may be filled with sand. If resin used, the tube is heated again after benditl and the resin is blown out with a bicycle or automobile-tire pump.—L. LAURIER.

June, 15 A Ru

OR th yellow woods an The Dp! typewrite Each leg to 27 in., the top b The len forming t the rear s of the leg pine lumk being 16 30in. T

If you u roundiny and these top, wher table grea The she 20 in. wid the right « in. deep. acecommod narrow sh for holdin of the sta The top 9-in. oak } in place b frame pol boards. A the size an

—_—__

Here th writer-s paper d typewriter with oak properly fi bottom of t base of the books and The dro] three brass use by mez lust the rij with the te

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his i] ch ing nd ve DVS, ome ront n, | read eive B is rate- It isa iron with rings when wood is the ever- than these onger learer rame. K is 1 con- pulley t. 2 steer: M cable > tiller t-rest wheel, meter be set rojec- center frame rk of ir (to k of 4

llustre ace af parts ped the hem it 1 other epaired ellac t0 CANE. ind * coppel have # >, Smas g if they Large resin 5 bending bicycle RIER.

June, 1921 A Rustic Typewriter Table for the Porch OR this table the frame is made from yellow birch poles that may be cut in the woods and are from 1 in. to 2 in. thick. The photographs show the completed typewriter table, both rear and front views. Each leg was 24 in. long, casters raising it to 27 in., allowing 1 in. for the thickness of the top boards. The length of the cross sticks of the table forming the ends was 16 in. The length of the rear sticks was 30 in. To hold the top of the legs firmly together three sticks of pine umber were used; the two at the ends being 16 in. long, while the rear stick was 30 in. The width of this lumber was 2 in.

If you use your typewriter in rustic sur- roundings, it should rest on arustic table and these sticks come just under the table- top, where they are not seen, giving the table greater strength than round sticks. The shelf for the typewriter paper was 20 in. wide and the book compartment at the right of the table was 8 in. wide by 20 in. deep. This compartment was made to accommodate letter files, books, ete. The narrow shelf directly under the machine is for holding two piles of typewriter paper of the standard size. The top of the table was made from two 9-in. oak boards cut 3 ft. long and secured in place by screws extending through.the frame poles into the under side of the boards. A drop-shelf 18 in. square adds to the size and convenience of the top of the

Here the front view of the rustic type- writer-stand is given, showing the paper drawer and the bookshelf typewriter table. The boards were finished with oak stain varnish, after having been properly filled. Boards were used for the bottom of the narrow shelf and poles for the base of the compartment at the right for books and files. The drop-leaf was attached by means of three brass hinges and held supported for use by means of a forked pole of birch cut just the right length to hold the leaf level with the table-top.—¥F. E. BRIMMER.

AO Years of Progress with Fine Tools “when typewriters were curiosities.” Forty years ago, when the typewriter was still a ‘new-fangled contraption”, machinists were begin- ning to learn what so many thousands know today —that Starrett Tools are made to insure complete satisfaction to the men who use them.

“Tools just a little better than were ever made before’ was the Starrett idea in 1880. It is the same in 1920. That ex- plains why Starrett Tools have had so big a share in the , industrial development of the country. “se

If you're interested in fine tools write for a copy of Catalog No. 22 “W”’. THE L. S. STARRETT COMPANY The World's Greatest Toolmakers Manufacturers of Hack Saws Unexcelled ATHOL, MASS.

GET iNTO THE TIRE BUSINESS! FOR ALL PURPOSES STANDARD MANUFACTURERS PROMPT DELIVERY $75 TO $200 A WEEK ALL SIZES UP TO SH.P. ith this machine, you can start a business of your own—do ure} | AA GASSER NUT Mal Cea ua] work that you can guarantee— and make bigger money than ALL PHASES AND FREQUENCIES IN STOCK AT ALL TIMES

ever before. Thor zh course of is 1 EF instructions free with eac h out- Largest exclusive Mail Order Small Motordealers in the world. fit. The Adams-Barre System of Vulcanizing makes re- . pairsthat are impossible by other methods. Can Ne CHAS. H. JOHNSTON, Box Ci). West End, Pittsburgh,Pa.

completely reconstruct tires at very small cost, All work guaranteed. Build your own business. s@P@ Write today tor details of @ Real Money- ff 1 Making Proposition. A y) e Sy The Adams-Barre Co., 1244 N. High St.,Cojumbus,0. Se Pilliod TOOL CASES EXCEL Machinists, Tool Makers and

110 volts-A.C. J 4p 1750 R.PM. 60cS.P, : Cord plug and pulley A Special Quantity Prices Write For Larsiog

Carpenters find them most Carpentry and Mechanics for Boys satisfactory in construction, appearance, service and price An excellent gift for the boy who likes to make things, Immediate shipment. Directions for making playground and camp equipment,

Booklet describing 20 styles models, mechanical and electrical toys and gifts, ete on request. Price, $2.65, postpaid The Pilliod Lumber Co. Popular Science Monthly Dept. A. Swanton. Ohio | 225 West 39th Street New York

SOUTH BEND LATHES For the Machine and Repair Shop REDUCED PRICES

fs Oe eee $215.00 | 13” Lathe............ $365.00 BE” DAMES 6 oc te cece ~aneeee 1 1G Lathe... .c<cces $450.00 rte BO RAN sk vctewcans $525.00 Run a Lathe South Bend Lathesare made in eight sizes, 9-in. to 24-in. swing inclusive. An 80- page Established 1906 Free Catalog

book for 10¢ Postpaid, Coin or Stamps. SOUTH BEND LATHE WORKS 433 MADISON STREET, SOUTH BEND, IND.

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Showing a Veeder Counter of the large set-back type on a Blake & Johnson arch press, counting the work as produced. Your best machines need this watching Whether the output can be increased by mechanical means, or by putting more up to the operator— COUNTERS get the gains! They show every picking-up or falling-off in pro- duction; register the result of changes in mechanism or operating method; record accurately what’s done over timed periods or daily runs. This small Rotary Ratchet Counter No. 6) counts reciprocating movements of the lever, as required for recording the output of the smaller stamping presses,etc. When the lever is moved through an angle ’ of 40 to 60 degrees, | the counter regis- ters one. The further the lever is moved, the higher the number registered. A complete revolution of the lever registers ten. This counter can be adapted to no end of counting purposes, by regu- lating the throw of the lever. Price, $2.00. (Cut nearly full size.) Counters for practically every type of machine are illustrated in the Veeder booklet. A copy should solve any counting prob- lem—and it’s free. The Veeder Mfg. Co. 44 Sargeant St., Hartford, Conn. Attract Customers by HE apparatus here described makes it possible to read a newspaper clipping whirling around on a disk making 3000 r.p.m. When assembled, the device may be put in a show-win- dow as an advertis- ing attraction. A good smooth- running battery mo- tor or a 110-volt fractional horse- power motor may be used. The bear- ings on the motor used should be in perfect condition so that they will not vibrate excessively when the machine is running at high speed. spoil the illusion. The brass disk upon which the clipping is to be mounted should be perfectly flat, as a wobbly disk will also tend to make reading difficult. The disk of sheet brass should be cut on a lathe. This can be done by attaching a block of wood to the lathe faceplate. Four screws are then used to hold the sheet brass to the wooden block. When the lathe tool is brought in contact with the sheet metal while the lathe is in operation, a nice clean-cut true disk can be obtained. A central hole is drilled in the Vibration will COMMUTATOR =" NEWSPAPER CLIPPING r /BX_BRASS DISK na / EFLECTOR (oY souvereo : rer SPARK COIL How this remarkable feat can be accomplished is illustrated by the plan of the apparatus brass disk so that it will fit snugly on the motor shaft. A small brass collar is turned on the lathe to fit on the motor shaft. The disk should be soldered to the collar and both to the shaft. A commutator is now made for the oppo- site end of the shaft. If the motor shaft is not long enough for this purpose, it may be necessary to replace it with a longer one. The brass portion of the commutator is made first. This is shown in the detail drawing. First a brass bushing about 4 in. long is cut. This should be about 3¢ in. in diameter. A slot is cut lengthwise in this with a hacksaw, and a brass strip is then inserted and soldered in this slot. then drilled through the center of the bushing so that it will fit on the motor shaft snugly. Just a slight driving fit should be produced. A piece of fiber is now placed in the lathe and turned down to a diameter that cor- responds with the distance between the top of the brass strip and the center of the brass bushing. The center of the fiber By L. A. Can you read a small sign or newspaper clipping while it is whirling around at 3000 revolutions a minute? A hole is Popular Science Monthly This Electrical Trick Laurier bushing is Ow drilled out with a 3¢-in. drill. A slot is now cut length. wise in the brags bushing as shown, This will perm’: the fiber bushing to slide over the brags piece. When this is done, the top of the little brass strip previously soldered in the brass bu hing should come flush with the outer sur. face of the fiber bushing. Two copper brushes are now made as_ shown. One of these brushes makes contact with the motor shaft and one rests on the surface of the commutator so that a connection will be made between the brushes every time the brass portion of the commutator comes in contact with the one brush. One end of each of the brushes is bent at right angles and each is placed under a binding-post. A small holder and reflector is now made for a Geissler tube. The Geissler tube should be of the plain kind with no fluor- escent liquids in it. The plain type gives more illumination than the fluorescent type. The Geissler-tube holder is supported between two little spring brass _ pieces attached to an upright board. Mounted behind the Geissler tube is a small semi- circular piece of bright tin or aluminum or any bright metal that will act as a reflector. With the addition of a small spark-coil (about 14 in. sparking capacity), the little apparatus is ready to be put together. The connections are shown. It will be seen that every time the brass piece comes in con- tact with the copper brush, the circuit will be closed and the primary of the spark- coil will become excited, causing the Geissler tube to become luminous. The light from the Geissler tube will be re- flected on the brass disk carrying the clipping. The brass contact piece on the com- mutator is so arranged that the circuit will § te fe-——— —— WOOD ) SPRING BRASS UPRIGHT STRIP AND PIECE CONNECTOR The Geissler tube in greater detail be completed only when the clipping on the brass disk is in an upright position. If the speed of the motor is 3000 r.p.m., the circuit will be made and broken that many times every min- , ute. It will be REFLECTOR pelle seen, however, scan: | that the disk will =" only be illumi- Sr ee nated when the SSS paper is in a ~ certain position. h Thus the news- —y paper clipping on the disk will ap- pear stationary and the clipping can be read with the greatest ease while the wheel i traveling at this high rate of speed. I the brass disk travels smoothly and does not wobble, and ifthe bearings of the motor are in good condition, a perfect illusion will result. 110 June, 192. Coolin Stz HIS ai connect line engine water circu out the bil As can | blocks of w of 2 in. an hole shoulc block to ta piece of th with pipe b with a shee so as tO Ma Takeas and clamp blocks, usi Bolts are | the whole of the pur exhaust lin in a horiz lower side the side ou Place two TE Alternat exhaust | to vibrat one On eac the drawir other the ¢ The pre line betwe cause the Drate in u engine, cat in the low changes i open and charging v to fill the y unless use impulse m Ke A SMAI cedar bottom o: kept, or keep out Clothes frc fill the elc Moth-ball:

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June, 1921 Cooling-Water Pump for Stationary Engines HIS automatic pump is operated in connection with the exhaust of a gaso- a & |ine engine and is used as pump for cooling lot & water circulation or, in a boat, for pumping th- # out the bilge-water. ASS As can be seen from the drawing, two mn. f blocks of wood are hollowed out to a depth he & of 2 in. and about 10 in. in diameter. A to & hole should be bored in the center of each ass BH block to take a 4-in. pipe tightly. Fitina his piece of this pipe in each block and fasten of with pipe bushings on each side of the wood rip & with a sheet of rubber packing under each, red BB oo as to make an air- and water-tight fit. ing Take a smooth thin sheet of new flat tin ish § and clamp it smoothly between the two ur- & blocks, using rubber or asbestos gaskets. ber Bolts are passed through holes to clamp the whole together. Connect the top side er & of the pump with a reducing tee in the OW & exhaust line and close up to the same and wn. & in a horizontal position as shown. The hes & jower side of the pump is connected with ‘ith FF the side outlet of a tee in a 34-in. pipe-line. and — Place two check-valves horizontally and itor een n of the shes iced ade ube uor- ives cent rted eces nted emi- num as a coil little The that con- t will park- the Alternating pressure and suction in the The — exhaust line will cause the tin diaphragm e Te to vibrate in unison with the explosions r the one On eac th side of the tee, as indicated in com- ff the drawing; one is the suction and the t will F other the discharge valve. 1g on The pressure and suction in the exhaust n. If § line between and during explosions will ., the § cause the diaphragm in the pump to vi- many &— brate in unison with the explosions in the engine, causing expansion and compression in the lower chamber of the pump. The changes in pressure cause the valves to open and close, thus drawing in and dis- charging water. It will be found necessary to fill the parts with water before operating, unless used in connection with a powerful impulse motor.—B. FRANCIS DASHIELL. Keep the Hungry be Moth Away = A SMALL bag of cedar shavings or a few eel isf—8 ~~ cedar-wood blocks placed in the ed. If bottom of a trunk in which clothes are 1d does kept, or placed in a clothes-closet, will of the keep out the moths and thus prevent the perfect clothes from being moth-eaten. It will not fll the clothes with a disagreeable odor as | | Four Reasons Why Ay || Williams Should Make Your aa fp ee e ° . a | Special Drop-Forging's 1 s 1. Because of broad EXPERIENCE, covering nearly | half a century, in making Drop-Forgings for leading : manufacturers. nal f 2. Because QUALITY has always been the first con- Ee sideration in Williams’ product. = | 3. Because DEPENDABILITY of Williams’ Superior Drop-Forgings will safeguard your own output. 4. Because FOUR COMPLETE PLANTS, in widely separated localities, offer unusual manufacturing and shipping facilities. Correspondence invited. We also manufacture and carry in stock a large variety of Machinists’ Tools, and will be pleased to send, gratis, books on any or all of the following list: ‘‘Bulldog” Wrenches, Drop-Forged Wrenches, Screw Wrenches, Wrench Sets, Pipe Wrenches and Vises, Machinists’ Tools, Lathe Dogs, Clamps, Caliper Gauges, Tool Holders, Eye Bolts, Hoist Hooks, Wire Rope Sockets. DROP — FORGINGS often cheaper than castings — always far superior = J. H. WILLIAMS & CO. ‘“‘The Drop-Forging People’ BROOKLYN BUFFALO CHICAGO oe i 7 Richards St. 7 Vulcan St. 1007 W. 120th Se, 2 St. Catharines, Ont., Canada. — * ee als aS ae ai a High Frequency Apparatus, Its Construction = ag Prectios for Flam: ease and Practical Application By Raymond Francis Vat The book omits nothing that By Thomas Stanieyv Curtis The most comprehensive and | will be of use to those ho use tools or to those who wish thorough work on this interesting subject ever produced to learn the use of tool 1920 edition—275 pp,—Price, $3.00 postpaid 314 pp 309 illu Price, $3.00 postpaid. Popular Science Monthly 225 West 39th Street, New York | Popular Science Monthly 225 West 39th Street, New York eB . el nf |Z v8 ex; One Man Saws 40 Cords a Day any size log at the rate of a foot a minute. At a Cost of 1c a Cord! Does the work of ten men. As easily Send today foi Rig Special Offer and Low | moved from log to log or cut tocut as any Direct Price on the OTTAWA, the One- | wheelbarrow. 4-Cycle Frost Proof En- Man Saw, the first made and sold direct | gine has balanced crank shaft—pulls over — factory touser. Greatest laborsaver | 4 H-P. Magneto equippe dj no batteries and money-maker ever invented. Saws sania Special Clutch ever controll- ed enables you —- = AW tosvartand stop saw with en- = running. Automatic Speed Cuts Down Trees Gove rnor. Easy to move, costs Lave) with Gro vund a] - PaViIT o Py -icon asso Down Trees— Saws Logs By ee | yam ogy hen not eave. Stump. Patent Applied For mills and other machinery. Pulley furnished, Cash or Easy Payments Shipped direct from factory. : 30 Days Trial No waiting—nodelay. Letthe —t os OTTAWAsawyourlogsandpay “for itself as you useit. 10-YEAR GUARANTEE. {ff See the OTTAWA at work on your farm once x 4 t and you will never give it up. Thousands in use, i ae’ 4 Zg every owner a booster. Out-saws any other on the ay FREE ‘ market, Send today for FREE BOOK a Special Offer. k and Low Price. moth-balls do.—G. H. GLITZKE. Write at once for 7 OTTAWA MFG: CO., 1805 Wood St., Ottawa, Kans. 111

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Popular Science M onlht Learn the Autoand Tractor Business InDetroit The Aluto Center . 7 Business : P of Your Own Thousands of openings await you. Fit yourself to conduct a successful business or to filla big money job. Think of the repair work necessary, think of the tires to be repaired, also batteries and electric systems to be ke pt in order on the nine and one-quarter million motor cars now in use. Splendid opportunities to start a garage, repair shop or service station of your own. Production is again increasing and trained men are moving forward. Men who understand the electrical end of the business are much needed. oPithe fonical piace, to learn the auto'and ~— Learn by Factory Endorsed Methods e 2 in ‘De t oit distr 71 or P . are made in the city. The greate Come to Detroit, the Auto Center, and learn the business as outlined motive experts are here, they helped by the leaders of the automotive industry. line our courses for you ’ Detro i t in Su mmer Leading Manufacturers Endorse Our School Packard Motor Car Co. says: ‘““‘We have no hesitancy in recommending M.S.A.S There are many ads antages in coming to Dots pie in every particular : an visi t . : Smobile factories during the Hudsonf§{Motor Car Co. says: ‘‘We recommend the M. S. A. S. and invite long summer evenings; inquiries ddress E. V. Rippingille, Service Manager es eee. The International Harvester Co ; We will gladly co-operate with the yr take a boat trip on M.S.A.S. through our 90 branches.” ‘Oat free catalog contains many factory letters the Detre Lake Erie ; feave It Is Necessary to Understand the Electrical End wharfs every few ee You can make more money for yourself or for an employer by qualifying In addition to an ‘ this, you will as an auto electrician. . ) find many ad here are thousands of good auto mechanics who know very little of elec- vantages in our ar eels fs li ss hi : ; . : : courses in sum- tricity as applied to automobiles and tractors. An M.S.A.S a saoahe “Sieasent : of all motor car troubles are the electrical end or arise from i; ‘ero field hs ha Hundreds of mechanics have come and taken our special electrical course. d other outdoo ae tivities in-ali lines Some went back to their old jobs but at more money. Others have gone Resolve to see out and douoled their salaries in electrical service stations. These stations \ A Detroit this sam are always looking for good men. Others have businesses of their own. mer and learn : the auto business \ | from A to Z.. BECOME AN AUTOMOTIVE ELECTRICIAN \ Our electrical course teaches auto electricity from the ground up. You get actual bench work in the laboratory, tearing down and rebuilding motors, generators, magnetoes, etc. We have practically every known make of ignition, lighting and starting systems for you to work on. Our course qualifies you for any position in the most up-to-date electrical service station or to conduct a successful electrical service station of your own. Ww id Autos, ; a te Actual actors ie Tire Repairing, Brazing and Welding, Battery Practice rey airing and machine shop work al Send coupon for full information the M.S.AS. } maar { —.~ MICHIGAN STATE AUTO SCHOOL ‘*The Detroit Auto School” **Endorsed By All Leading Manufacturers”’ 586 Auto Bldg., 3729 Woodward Avenue DETROIT, MICH., U. S. A. S cy Ro rt

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