Popular Science Monthly 1919-10: Vol 95 Iss 4

Page 1

4 tory 5.00 lax- Popular Science Monthly Waldemar Kaempffert, Editor ' October, 1919; Vol. 95, No. 4 Twenty Cents; Two Dollars a Year Published in New York City at 225 West Thirty-ninth Street os be — | ——— ——- —~ Fighting Fire from the Sky The forest ranger becomes an aviator ISITORS to our national parks \ this summer have been consider- ably puzzled by the frequency with which airplanes and dirigibles have skimmed overhead. No reason for this activity was apparent, now that the war is over. However, an excellent reason has existed: the flyers were acting as aerial patrols, watching for and reporting any forest fires they discovered. Thus Uncle Sam has found an important use The dirigible has just dropped a bomb—not to blow up the forest below, but to put out the fire there; the bomb is filled with fire-extinguishing chemicals By Robert H. Moulton for his aces of the air right here at home. Heretofore the work of patrolling United States forests to locate and fight fires has been entrust- ed to men on horses, motorcycles, or railroad speeders, and partly to watchers stationed at lookout points. The former travel about from place to place, while the watchers, who are located at advantageous

Page 2

eae a unre SS a spots, usually on the top of some high mountain-peak, never leave their post, but remain constantly on the lookout for fires. The observers at lookout stations are provided with all the latest scien- tific instruments for-locating. distant objects, and*-with carefully prepared maps showing the names of all canyons, streams, roads, ranger stations, and the like. How the-Watchers Do Their Work ‘These men have powerful field-glasses, and a telephone leads to the nearest ranger station and to the forest super- visor’s office. If a fire is discovered, the watcher immediately telephones to headquarters, giving the location of the fire as it is projected on the map of the station; a crew of men is des- patched to fight it. The efficiency of this system has been increased from year to year, until now it is as up-to-date and as successful, in its own field, as that of a municipal fire department. In fact, the same essential factors for success are employed in the forest work that are universally recognized as neces- sary for fighting fires in cities: namely, first, detection of the blaze before it has gained headway; and, second, prompt attention. According to reports compiled by the Forest Service, there were in the United States an average of 28,735 fires a year between 1915 and 1917. The ground covered by these fires amounted to 8,052,945 acres. The esti- mated damage was $9,875,000. A report covering the period be- tween 1913 and 1917 showed a yearly ‘average of 6,184 forest fires, with 666,663 acres burned and damage to the extent of $599,000. Last fall it occurred to officials of the Forestry Bureau to supplement the work of the regular forest rangers by the addition of air scouts, and a few experimental flights were made to de- termine the value of the airplane and dirigible in this connection. These experiments proved so satisfactory that Secretary Baker issued an order directing the Air Service to cooperate with the Forest Service in the work of forest fire patrol, and, beginning with the first of June, the plan was regularly put into operation. Air scouts and bombers who saw service in the Great War were set to work in the forests; and dirigibles — filled with the new non - inflammable helium. gas in- stead of dangerous hydrogen—will also be used in patrolling the forests for fire. Reports receiv- ed by the Forestry Bureau show that the airmen experience no difficulty in detecting fires in heavy timber at an elevation of ten thousand feet and even more. From this ,it will at once be evident what an advantage the air scout enjoys over the watcher in a lookout station. Even when these stations are located on mountain-tops, the range of the observer is more or less limited by reason of the character of the country cut by deep canyons and broken by mountain-ridges. Fur- thermore, the area of country that he can see at any time is always the same, whereas the airplane scout, flying swiftly at a much higher altitude, is enabled to cover a wide and ever- changing stretch of country within the space of a few minutes. The aerial observer has still another advantage, of the greatest importance, over the watcher in the lookout station. The latter, when he has discovered a fire, can do nothing more than tele- near by there for use should Airplanes and dirigibles will co- operate with the watchers at look- out stations; this watcher has be- fore him a map of the forest, and is a telephone, he detect smoke Popular Science M onthly phone: its location to the nearest fire guard; he depends upon others to go to the scene and combat it. On the other hand, the air scout, when he has located a blaze, can send in the alarm, and then, swoop- ing down, over the spot, drop on it bombs charged with suitable chemicals for ex- tinguishing fires. By this means he is frequently en- abled to put out the fire unaided, or to check its growth until the regular fire-fight- ers have time to reach the place before it has gain- ed any consider- able headway. In this connection, a plan that is soon to be tried out proposes trans- porting fire-fight- ers in dirigibles from which ladders can be lowered to the ground. Warnings Flashed by Wireless The observer in a lookout station locates fires by means of triangulation, reports being telephoned from separate observation points. The air scout locates them by coordinates in the same way that gun-fire is directed to a particular spot or object—that is, by means of squares drawn on dupli- cate maps, one being in the possession of each airplane observer and another in the office of the forest supervisor. The tentative plan is to equip the patrolling airplanes with wireless sets, with which the pilots may flash the first signals of fire. Roads and path- ways where a carelessly thrown cigar- ette may be the cause of thousands of dollars’ worth of damage will, of course, be. watched particularly. Regular war-time bombing planes are used; it is planned also to use dirigibles filled with the non-infammable helium gas For years fires have been fought by crews of men alone; they chop down trees at the edge of the fire in order to check it

Page 3

it- on ut 1S- ht- ers on, ate out the | to is, pli- ion her the ets, the ath- rar- is of rse, October, 1919 Putting Hinges in the Football Shoe T the quarter-back’s signal for a A run around right end, the half- back sets his shoe-calks into the earth and waits for the ball to be snapped back. But a husky guard on the opposing team _ breaks through, the quarter fumbles, and there is a wild scramble. The half- pack swings in his tracks and dives into the middle of the struggling players. A moment later the ref- eree’s whistle sounds, the human omelet is unscrambled, and the half- back emerges with the ball. : hgh —a A moving picture of a conductor in action leads the orchestra; lightning-like change : at the same time the audience gets a view of the conductor’s back of direction might have put the Immortalizing the Band Leader half-back out of the game. N the theater the [feecseeessssq MOVING PICTURE It is to mini- orchestra tunes up, CAMERAS mize such the lights go down— aie 3 mischance the play is about to ree et that a Chi- start. Suddenly a Twocameras, op- wee: eago firm has turned out a football shoe with a double-hinged ankle support. The shoe com- bines flexibility with perfect moving picture of a ¢tated by one ’ crank, simultaneously take seni s back sid pears om both front and back views a screen just in front of the orchestra-pit. It is a famous musical conductor; and while you look at his back, the orchestra sees him leading it. In taking a picture like this, the subject stands between two cameras facing each other and operated by one crank. From the two negatives thus made, one positive, such as is used in the pro- _jecting lantern, is made. The film is run off on a screen divided in two: the top view is translucent, so that the audience may see it. ORCHESTRA LEADER Hinges give it a freedom of move- ankle support. ment impossible in a rigid shoe Bringing the Pedals Up to the Feet Its One Fault HE ‘‘do-re-mi-fa-sol-fa-mi-re-do’’ days of piano practice are the dreariest OME time ago a traveler brought of allto the young pianist. In the first place, he (or she) would far rather be home to England a ‘‘Kaffir pick.” outdoors, playing; then, the scale itself is expressionless, andisrendered moresoby It was a versatile tool, the natives the fact that his legs are not long using it as an ax, a pick, or a enough for his feet to reach the spade. It was shaped like a pedals, reminding him of the fact heart. A British manufacturer that he is quite uncomfortable and undignified because his feet dangle aimlessly. Yet all this trouble would be eliminated if the piano were equipped with one of Arthur P. Smith’s “extension pedals.” The pedals jut out of the top of a hox that bridges the distance between feet and floor. By means of a screw-bolt and an arm that ex- tends under the piano, the box is held in place. It is provided with cushions, so that it will not scratch either the floor or the piano. The extension pedals are di- rectly above the real pedals, and are so arranged that when they are pushed down the real pedals go with them and register ‘‘soft’’ and “loud.” The extension ped- als are provided with springs, so that they will rise back into place when the pressure is re- moved. Her feet rest on a box that is equipped with extension pedals; thus she may play in comfort and with expression 23 saw it, and decided he could make it and market it more cheaply than could the Kaffirs. He produced a pick so like the original that the Kaffirs couldn’t tell the difference—so he thought. Salesmen went forth to South Africa with their British-Kaffir picks, expecting a harvest. But, strangely, the harvest was not forthcoming; the picks remained on their shelves in the shops. Sadly the salesmen returned home—all except one. This tenacious one took a trip up country, talked to the Kaffirs, and learned what was wrong. In addition to its other uses, it seems that the Kaffirs take the pick from its haft and use it as a cattle cail, and’ they had dis- covered that the British-made article did not have quite the right note. The manufacturer quickly remedied this, and sales picked up.

Page 4

SSeS eS a ; eee oe When the Wind Blows, the Wagon Will Move ZIP-CAR race. Why are they called “gip”-cars? We haven’t any idea; but a zip-car is a small four-wheeled wagon on which is mounted a cardboard windmill. When the wind blows the windmill goes round, and the power thus gained makes the wagon move. The windmill is mounted either in the direc- tion of motion or else at right angles to it. In this race it looks very much as if her wagon, which has eight sheets to the wind, will beat his wagon, which has only about four. Since the zip-car is propelled by the wind, it might easily be called a sail-boat on wheels. The children seem to enjoy playing with these land boats as much as if they sailed on water—and in the case of the zip-car there is no chance of the children falling into the water and getting their nice clean clothes muddy. Fording Streams O wonder the lady below leans anxiously over the edge of her ear. All she sees is water, water everywhere—even on the road over which she rides. Will she have to jump out and swim? she wonders. Such is automobiling in Jamaica; the roads are often under . water. But the explanation is simple. Jamaica is an island about one hundred and forty-four miles long and only fifty miles in breadth; yet on the island there are as many as one hundred rivers © Publishers’ Photo Service time” Lock-Makers of Leipzig EHOLD! A parade that has nothing to do with Bolshevism or higher wages. This unusual occurrence took place in Leipzig, Germany, soon after end of the war. The men are sandwiched into large locks, and they carry in their hands signs on which more locks appear. An indication of their desire to lock up the Kaiser? No; the lock- makers’ section of the manufac- turers’ advertising parade. Before the war Leipzig had one of these parades every year; it was part of the annual fair. During the war these fairs were suspended; but now the people of Leipzig are having their fairs again. Popular Science Monthly | A Bicycle Built for Two Elements ERHAPS one hot day Mr. Jack Belbin, of London, England, wished he could ride his wheel in the Thames instead of along a dusty road, and of the wish was born the queer land and water craft with which he makes his fellow Britons stare. His plan is simplicity itself. Fasten a float securely to each side of the bicycle, leaving room for the legs to make the pedals go around, put on rubber boots if you mind wet feet, then ride right into the water, and keep up your pedaling. Of course you can’t make much speed afloat, and unless you wear a bathing- suit it’s best to choose a calm day for your spin in the water. We also suggest skid chains, for when you come out of the water dripping wet your wheel will have a tendency to slide sideways; and it is very likely to stay wet for some time, in an Automobile and streams, which empty into the sea and have their sources in the mountainous interior. At flood-time these many rivers over- flow their banks and often cover the roads completely, causing much inconvenience. The mountains of Jamaica run as a sort of backbone down through the.center of the island. This backbone, together with the general outline of the island, makes it look like a huge turtle rising out of the sea.

Page 5

yO Jack wished ‘hames | of the | water fellow Fasten icycle, ke the 00ts if nt into ling. 1 speed athing- lay for suggest out of el will and it 2 time, rees in 3 over- ausing . down r with turtle October, 1919 TTT, Pees I | 7 —, Ne _O—-Y Om The Funnel’s the Thing It looks very much as if the limousine above were going to try to ride up the side of the tunnel-like structure in which it stands. But that is no stunt for a new limousine to try. The car is being used merely to bring out the size and strength of a section of a battleship funnel. The funnel had just been com- pleted, and was planned for use on the battleship Almirant La- torre, built for the Chilean government. What we are wondering about is how the car got in, and how it will get out again. There seems to be little room for it to maneuver in, and no road for it to follow when it does turn around. Funnels on small ships are usually made of sheet-iron—often called Russian iron. But in the case of battleships and other large vessels the funnels are made of great, heavy plates ribbed together and riveted. The plates are specially made, and are carefully curved so that they will give a smooth finish when fastened together. In small ships the funnels are usually cylindrical in shape. But in larger vessels they are often oval—like the one above. What a Hair Will Do “EE people on the ground are not eagerly waiting for the pagoda in the picture at the right to topple over and crush the boy in front of it. No; they are quite. sure that the pagoda will not fall, since the stone on which it was built rests on a hair taken from the head of Buddha. These people are Buddhists, and they have great faith in that hair. Of course, it may have decayed during these centu- ries since Buddha departed, but its spirit is evidently still there. We must believe that the Buddhists are very devout people; for almost every picture we have ever seen of them shows them wor- shipping at some strange altar like the one ‘shown here. ‘‘More and Better Milk’’—the New Drama |F memory serves, it was in “Evangeline” that the domestic cow first made her appearance on any stage—and the cow was only a calf at that. But nowadays the cow and her husband are getting into all sorts of places. Not long ago we showed a gentleman and lady cow of blue-ribbon pedigree gracing a bank to help out a Liberty Loan drive. We just missed preserving for history the photograph of a prize bull that had a suite at the Waldorf-Astoria (he regis- tered and left between editions); and now we hasten to present two cows doing a sister act on the stage of a theater at Ashe- ville, N. C., where they appeared in a piece entitled ‘“ More and Better Milk.” The cows are Holsteins imported from Wisconsin, and the Ashe- ville board of trade reports that as’ a result of staging the cows four hundred and fifty-eight head of Holstein cattle have been brought into the mountain country, where their milk is needed for three thousand sick and wounded soldiers in the government hospitals. Off for a Swim with Two Oil-Cans IL will calm the troubled waters, and oil-cans will soothe the would-be swimmer. For two oil-cans will make an excellent life-preserver. You empty the oil out, pump air into the cans and plug up the holes, then tie the two cans together. They act as water-wings, and are of sufficient buoyancy to hold up a grown-up person for an indefinite length of time. Of course, when the cans hit each other they make the usual tin-can racket; but then, it’s a good idea to make yourself conspicuous when you are swimming in deep water. The girl that smiles in our illustration up- holds the oil-cans that are obviously uphold- ing her. Though oil-cans tied together resemble the customary water-wings made of cloth, they are really much safer. The air in water- wings is bound to ooze out gradually because of the porous condition of cloth. Thus a person can use them for but a ‘limited amount -of'time. Such is not the case with tin,

Page 6

Popular Science Monthly Try It on the Root “FT CAN outdo Locklear or Law,” said Mr. Jug Rey- nolds, a New York city dare- devil; and he immediately be-. took himself to the roof of a twenty-two-story building, and did a shoulder stand on a kitchen chair placed precari- ously near the edge of a small table which rested on top of a chimney. A dangerous stunt, to be sure; but was it as risky as Locklear’s drop from one airplane in flight to the top of another? Mr. Reynolds feared that the spectators might not think so. Forthwith he climbed down, brought up three more chairs, and tried another stunt. On the table he placed two chairs so that they touched each other face to face. He climbed up, and then placed the other two chairs so that their front legs rested on the edges of the lower chairs. And on top of this tower of table and chairs he stood and looked down at the street far below. _ No vain boaster he! Jug Reynolds said recently: “I can outdo Locklear or Law.”’ his best to prove his rash statement my ft And here he is trying Only a daredevil would do a shoulder stand on a chair that stood on a table that rested on the chimney of a twenty-two-story building An Airplane that Rose from a Sea-Sled UR Navy, always doing something unusual, recently made the ex- periment of allowing an airplane to “take off’’ from a fast power boat going fifty miles an hour, and, as usual, got away with it, besides settling some ‘questions concerning certain experi- ments. The airplane, which had the usual wheeled launching and alighting gear, was lifted by a derrick and lowered into place upon the sea-sled, being simply chocked to hold it in position. The sea-sled got under way, and taxied out into the bay, where her multiple-cylindered engine was opened wide and she began to tiptoe over the light sea at her best speed. In obedience to a signal the airplane pilot started his engine, gradually run- ning it up to the same speed as the boat was making. Then suddenly he opened wide the throttle, and with a roar the air- plane took the air, going straight upward as if it had been thrown from a catapult. This was done again and again to satisfy the officers that it was not merely a case of luck at the first attempt. Now, we wonder, could this experi- ment be reversed and the airplane be made to alight upon the sled while it was under way? We see no reason why it could not be done if some means were provided so that the airplane’s pilot could gage his airplane to alight in exactly the place where . it took off. But don’t worry; this experiment is probably under way by now.—FRED G. JOPP. The airplane being mounted upon the sea-sled, with the pilot in his seat, ready to “take off” Photographs courtesy of the Path¢d N2ws Service The airplane rises straight up as would an elevator. Air- plane and boat are traveling at the same rate of speed

Page 7

ase eri- be e it son ans hat uld ght ere . on’t ent 4 by ff ‘jumping-off ‘place of civili- intrinsic strength, because it gets its ‘support by leaning on other plants. HREE sturdy automobiles, each bearing several men armed with heavy army rifles, speed through the Australian landscape. They come from Adelaide, South Australia, and head northward toward the heart of the plain which extends in unbroken _dreariness for hundreds of miles in that direction. The lookout in the leading car scans the horizon with a field- glass. “There they are!’ he calls out, pointing to a slight rise. The heads of a few kangaroos are plainly visible above the salt brush, which grows beyond Burra Burra, the zation. The whirr of the engines must reach the animals’ sensi- tive ears; for they take to flight with tre- mendous bounds. Ata distance of three hundred yards they stop. The automo- biles continue in their wild rush over the Why Is Rattan B NE of the longest of all plants, perhaps the very longest when diameter is taken into considera- tion, is the rattan, a member of the palm family. The rattan palm does not need The porous or tubular character is found in most plants of its habit, and seems to serve the purpose of secur- ing alarge quantity of water through a comparatively small stem. These large ducts give thestem, in cross-section, a eable-like appear- ance, though in the plant each one of the cable-like wires is a tube. In other plants a tube might be employed for utilizing the material in the best possible manner for strength, as, for example, in the grasses, where the stems are hollow, ‘) ky © The poor little kangaroo hasn’t much chance with this new terror pursuing it rough ground, and now the hunters let their rifles speak. One of the animals is wounded. The remainder of the herd, keeping well together, leap away in one direc- tion, while the wounded animal hops with terrific speed in the opposite direction. The nearest car takes up the pursuit, and for three miles con- tinues in its course, parallel to. that taken by the wounded kangaroo. The brush becomes thinner and the hunters head their car in astraight line for the animal, which shifts its course to an angle that brings it directly across the Kangaroos in great numbers annually invade Australian ranches and destroy crops. Hunting them was formerly an almost hopeless undertaking, but now a day’s hunt by automobile will frequently bag fifty or more a 5" 2 : ' ‘ “2 q Y d @ =e 4 F ” tye Its tubular character seems to.serve the purpose of securing a large amount of water 27 Hunting the Kangaroo 4. The modern way is to track and shoot the animals, seated in a comfortable motor-car uilt Up of Tubes ? a By Earle W. Gage path of the oncoming car. A _ well aimed shot ends the flight. Now, back to the pursuit of the rest of the herd. After a drive of a few miles the animals are sighted. At a distance of fifty or sixty yards the hunters open fire, killing four of the animals. The fifth, a young kangaroo, takes to the open country. The hun- ters have decided to catch it alive. As they approach their prey, one of the hunters creeps forward on the running- board, seizes the kangaroo by the tail, and manages to hold on to both car and animal until the car is stopped. Each year, during the pro- longed drought in the Austral- ian bush sec- tions, the kan- garoo becomes a pest in the farming sec- tions, great numbers in- vading the ranches and de- stroying the crops. Before automobiles were pressed into service, kangaroo-bunt- ing was almost a hopeless job. because the amount of material thus placed within the culm will give the greatest amount of stiff- ness. In the rattan the smaller tubes have the reverse function. Per- haps, from the mechanical point of view, nature does not desire to gain either end. The result of the’ peculiar ar. rangement of the material is a remarkably flexible stem, so that rattan is well adapted for weaving and for various purposes in which extreme flexibility, to- gether with strength, is desirable. It is also used extensively in the form of walking-canes, wicker chairs and other furniture, and- thin strips of it are woven into mats for floor covering and sun curtains.

Page 8

Popular Science M onthly From Beer to Maltose -How one brewery managed to stay in business _ 5 ace PAN DRAIN OFF TANK BARRELS CATTLE FEED This is what the chemical engineers call a “‘flow sheet.” It shows the way in which corn is con- verted into malt- 7 : ITN SENET TITRIRTTTTTE 3 ose, oil-cake meal, - x a Wii teua and cattle feed j . we To the right and above is the filter press that the brewery needs if it wants to make maltose. The press is used aye - 7 ~~ to clarify the juices that most ° = ; a ’ , . of us now drink to slake our . | : thirst, Maltose is bought not only by the soft-drink manu- facturer but by the candy- maker and the bread-baker Oscar, the hero of this prohi- bition drama in pictures, is drawing off maltose sirup worth about one dollar a gallon. Even before prohibi- tion was forced on us, there were ten thousand establish- ments engaged: in making soft drinks, and most of them used quantities of maltose Now the vats and kettles store ginger- ale, and sirups that you drink in your cherry, lemon, strawberry, rasp- berry, orange, pine- apple, grape, and Phosphate soda. Since we’ve got to drink something, maybe the brew- eries will stay in "aa ae § be business, after all BR oo -. * % wp ers ee, \ Bone filters must be installed in the re- formed brewery if it is to make maltose from barley malt The cooker used in converting the starch in corn and in barley into maltose, is the Here are the vacuum pans for the concentration of the light sugar solutions. Vacuum evaporators are same that made beer. > E i additional equipment in All bottled soft drinks ?, = A agente oS) Se a ‘ Pat! the brewery. The appa- contain water, flavor, ; ‘| ~ foo ee AL ratus required in brewing is sweetening, and some- complicated and expen- times _carbon-dioxide sive. Much of it is made gas. The breweries of copper, and is adapted have most of the ma- to delicate operations chinery required for making soft drinks

Page 9

yrohi- es, is sirup lar a dhibi- there blish- aking them altose pans m of ions. are t in ppa- ngis pen- nade pted ‘ions October, 1919 After a Coconut Leaves the Tree Its varied career, ending at last in a soap factory You can’t blame the monkeys for dropping coconuts on people’s heads, the nuts are so plentiful. Each tree turns out sixty nuts a year— starting when it’s five years old A sharp steel knife cuts the coconut The husks are turned into fiber, called coir, which is used in making cordage, brushes, and mat- the nut is turned into oil In the oil factory the coconuts are pressed or boiled. A thou- sand nuts yield twenty-five gal- lons of oil, which is used chief- ly for making candles and soap The nuts are broken into small pieces and dried in the sun; the copra—as it is then called—is sent to the coconut-oil factory For lack of train service, the coconuts travel down the river to the factory on-rafts, after the fashion of logs

Page 10

ae Popular Science Monthly Live Fowl by Parcels Post & Hheew- cake-box that the postman is so carefully carrying A. in his hand contains, not cake, but two baby chicks, There is also in the box some straw and enough food to last the chicks till they reach their new owner, who igs seventy miles away. They are traveling by parcels post, It has been found that it is easier and cheaper to ship chickens after they have come out of their shells than it is toship the eggs. In the first place, the eggs are all hatched in one incubator, The resulting chickens stand shipment much better than eggs. They do not need to be packed in excelsior, so they really’ weigh less than the eggs would do, and the cost of sending them is less. But what makes the plan really feasible He is injecting germs from a diseased chicken into a well one, in order to test the germs’ capacity for producing disease He Doctors Sick Chickens NY hen, or Dr. B. F. Kaupp, a poultry pathologist, will tell you that chicken diseases, including the Moreover, Dr. Kaupp will tell you that they are most interesting. For instance, the correct dose of sulphate of strychnine for a hen is one It would kill a human being. Dr. Kaupp is about the first scientist who has He is connected with the North Carolina Experiment Station, where he has saved many a chicken’s life—temporarily, at least. pip, are no joke. fifth of a grain. specialized in fowl troubles. HE nectar that honeybees gather from flowers is changed within . the bee’s body into a secretion that is exuded on the surface of the wax- plates on the lower side of the worker’s abdomen. These secreting surfaces, or wax-plates, may be seen by examin- ing the under surface of a bee’s abdo- men with a low-power microscope. The glands that secrete the wax are on the abdomen, immediately above and in contact with the wax-plates; and the exu- dation of the wax takes place through minute pores. As soon as this fluid wax comes in contact with the air it hardens and forms a coating on the outer surface of the plate. This is gradually thickened by the addition of wax from the pores. Now, bees possess an ingenious, though not al- ways effective, mechanical device for removing these scales, and the operation generally takes place is that newly hatched chicks do not need water for twenty- four hours. After that time they take up regu- lar drinking habits, and might die of thirst if sent on a long journey. The postman will see that the baby chicks arrive safely at their destination How Bees Get Rid of Their Wax Scales By Edward F. Bigelow called pollen-combs. shows that many of the scales on the bottom of the hive have been scratched by these spines or by the mandibles. ‘ The device seems to work fairly well, but not ideally so. Sometimes the bee will take a scale from one side, and then These spines are stabbed into the scale, sometimes catching the scale and sometimes not. At wax-building time the bottom of the hive is sprinkled with scales, although it is asserted that these are sometimes gathered up and utilized. The scales are then passed forward to the mandibles. The microscope from the other; sometimes two or three in succession from one side; frequently it will try to push off the scale, but unsuccessfully. It will persist until the scale is impaled on the spines, or until it becomes discouraged and discon- tinues. Whenthespinesdo seize a scale, it is quickly transferred to the mouth. Sometimes, when the scale reaches the mandi- bles, it is worked over by them alone; but at other times the fore legs are used to assist the man- dibles. If the scale is thin the mandibles can handle it alone; but when it is thicker the bee calls on the legs for help. At while the bee stands on the comb. The hind legs are fitted with rows of sharp hairs, or spines, spines, called pollen-combs. in removing the wax that forms on the under side of its body; this wax hardens on. contact with the air The bee’s hind legs are fitted with sharp hairs, or 30 The bee uses these spines first the masticated wax ~ is rough and flaky, but later it is reworked gain- ing in smoothness.

Page 11

ying cks. 1 to 0 is 0st. ship it is , the ator, nent not less ould t «(of hem But akes lan sible ewly ied » not ater nty- ours. shat hey regu- iking and ie of sent long Ss on been y the well, e bee then Oo or side; I the il the 1 the omes scon- 1es do lickly outh. 1 the andi- er by other 3 are man- ile is / ean when > calls | wax ~ r, but gain- October, 1919 Spoiling the Hog’s Sport IGS spend most of their lives trying to wear out their noses. They succeed in doing a good deal of damage to the pasture without injuring the protuberance. Nat- urally, the farmer objects to the destruction of carefully grown turf, and with a specially designed tool he puts little metal rings in the gristly upper rim of the pig’s nose. A “rung” pig is comfortable as long as he confines his food hunt to the surface of the ground. ; Ringing a pig of ordinary size is easy, but special arrangements must be made for handling the big ones. Sometimes they are caught and hog- tied; but if there are many to be held, a stanchion or stocks, such as the one shown in the illustration, is helpful. The frame is made of two by fours and two by sixes. The sides of the stan- chion are hollowed out so as to fit the animal, whose neck is practically as wide as his head. A single cotton seed cut in half, with the delicate fibers radiating from its centre The pig must be restrained while his nose is being “ringed’’; in this type of stan- chion he is held in by his ears and his rolls of fat Put the Water-Tank and the Silo Under One Roof HE silo and the water-tank are Siamese twins now on many farms. By making the foundation a little heavier and by putting the tank up on top, one roof is made to do the work of two. The tank is put on a high tower with only a little added expense, and the pressure obtained makes it possible to throw a stream of water over any of the build- ings on the farm. In the country, far from city fire de- partments to be called on for help at a moment’s notice, this sort of protection is very important. The pipe from the tank passes down through the silo, which is warm, except right at the wall, in the severest winter weather. This eliminates much of the danger of freezing. The ladder is for conve- nience in placing the blower- Cousin to the Hollyhock In drying, the round cotton fibers shrivel into spirally flattened forms; on this peculiarity depends the value of cotton for spinning SIDE from the botanists, -probably not many people associate cotton with the succulent pods of okra from the kitchen-garden or with the tall hollyhock. In common with these, however, cotton belongs to the great mallow family, and is cousin to both okra and hollyhock. In the early part of the sixteenth century it even had its place in the Colonial flower-beds of Maryland; but it has been a long time since cotton appeared in the flower-bed. Cotton, as it is now made, is composed of the fibers produced by this plant. These are single-celled hairs that grow upon the seeds of various cotton plants (Gossippium). In Sea Island or long-staple cotton these fibers reach a length of about two inches; but in upland or short-staple cotton, which is the main crop of this country, they are very much shorter. Each capsule, or boll, is about an inch in diameter, resembles a squatty acorn, and contains many hairy seeds. These are packed tightly into a hard mass in the unripe boll, which on ma- turing splits lengthwise into from three to five sections. These pieces then open out, allowing the hard, compact mass to dry and expand into a loose, fluffy tuft. It is these tufts that are gathered and taken to cotton-gins, where the fibers are removed and pressed into bales. Cotton is cellulose in its purest form, and ig an im- portant factor in the manu- facture of smokeless powder. It is estimated that a bale of cotton was dissipated into gas at each discharge of some of the big guns used in the world war. Strangely enough, the pic- tures you see of these very guns in action depend upon cotton; for, dissolved in alco- hol and ether, cotton forms the basis of the collodion used by the photo-engraver in making In placing the water-tank on top of the silo, one'roof the plate from which these pipe at silo-filling time. does for both; also better water-pressure is obtained pictures are printed.

Page 12

Popular Science Monthly ‘To Keep the Car from Rolling When It’s Jacked Up O remove the tire or demount- able rim from the rear wheel of an automobile it is necessary to jack up and revolveit; thereforethe brake must be released. It injures a tire to run on it while deflated, and if it has gone flat on a hill, the other wheel must be blocked before it is safe to release the brake. On paved roads and streets, or in stoneless localities, a satisfactory block is not always easily found. One motorist made a block, which he carries with him. This is how he made it. He took a piece of wood about ten inches long and four by four inches thick, and sawed it into two blocks of equal size, making a diago- nal cut. This gave him a block wedge-shaped at one end—just the The wedge-shaped block under the left-hand wheel is a very useful arti- cle in emergencies. It is easily made by anybody with a little ingenuity, and may be easily carried in the car VW HEN the engines of this Cana- dian dredger have served their purpose of propelling the craft to a channel that is to be deepened, they are coupled up to drive the dredging buckets. You will note that a shaft runs centrally through the hull of the vessel, and that at its forward end it 32 thing for blocking purposes and large enough to hold a heavy car on a steep hill. It is light, easily carried or stowed, and cannot injure the tire. A set of these blocks often comes in handy in the garage; for some- times, when working around a car, both rear wheels must be jacked from the floor, and then it is neceg- sary to block the front wheels to remove any danger of the car mov- ing forward or back. In cases like this, these blocks are just what are required. Safety demands that when a car is left standing alone on an incline for any length of time, its wheels should be blocked, to avoid acci- dental releasing of the brakes. The Ship that LADDER-HHEAD GEARS OVER-SIDE CHUTE / STEAM - WINCHES. So ease da ss has a bevel gear by which the drive is transmit- ted to the ladder-head gears. Near the engines are change gears, the purpose of which is to provide two ladder speeds. Two sets of buckets are supplied. One set, of fifty-four cubic feet capacity, dredges soft material; the other, of thirty cubic feet capacity, is used on stiffer ground.

Page 13

and car sily jure mesg yme- car, *ked ceg- s to nOV=— like © are car ‘line eels .cci- kes. at October, 1919 Why You Can HEN a disk record of a band is’ made for the phonograph, the vibrations pro- duced by the sound waves emanating from the various in- struments are engraved on the recording disk simultaneously by one and the same needle. Since each instrument has its own peculiar tonal quality and pro- duces tones of a highly compli- cated character, accompanied by over--and under-tones that cover and blur one another, the record ° loses the finer shadings of tone and color and some of the char- acteristic individualities of the various instruments. Samuel D. Mott, an inventor of Passaic, N. J., seeks to overcome this defect by a modification of the a grabh fepeodiictica,” ecards ofa” ing and reproducing. apparatus. - individual record is made of each Play a Whole Opera on This Phonograph DISK RECORDS \ LINES EXTENDING NEEDLE DROPS TO : NEXT RECORD HERE + cate FROM CENTER OUTWARD) An invention designed to overcome the blurring of tones that usually occurs in recording a brass band for ‘phono- instrument or group of instruments are made first and afterward synchronized instrument or a group of instru- ments. These records are carefully synchronized, and are then re- produced simultaneously on one or several phonographs. To this end the disk record of each instrument or group of instru- ments is provided with its own individual sound-box and stylus transmitting the sounds to a common horn. By a series of gears or an end- less belt or chain, the power of a small motor is transmitted to the turntables bearing the disk records by means of a friction drive. These disks are placed so that one overlaps the other. The same inventor has also pro- vided a means.of reproducing: without interruption musical or other records requiring two or more disks. Digs Its Way Deep Down Under the Sea a Me ene SS pose The craft is called a ‘“‘hopper’”’ dredge, because the material excavated or dug up—the “spoil” — — | LADDER WELL is lifted to the ladder-head and dropped down forward. through a hopper into the hold, or else, by means of chutes, into barges on either side. From what depths can material be excavated? When the ladder is inclined at forty-five degrees, depths of fifty-seven feet can be dredged. When the craft is ready to move on, the ladder is raised by a steel-wire rope attached to an independent engine At the bow and stern are maneuvering winches driven by independent engines. By their means the mooring-chains can be worked either inde- pendently or simultaneously. The hopper doors are also independently driven by steam winches

Page 14

hihi How the Army Saved Space in Storing Automobiles NY one who has been compelled to find storage space for his automobile in the congested district of a big city will sympathize with the officers-in charge of the storage pro- gram of the army: when‘they .were called upon to store thousands -of cars and trucks. It is a costly proposition.to build | warehouses covering acres of land to store vehicles that take up a great deal of floor space but leave many thousands of cubic feet be- tween the vehicle and the ceiling. A system of storing automobiles was devised, whereby the car rests onend. ‘This is accomplished either by standing the machine on its front wheels, springs, and axle, the rear wheels being braced only enough to keep the car plumb, or by literally hanging the car to the ceiling. In this way thousands of feet of floor space was saved. In order to store the cars properly The magneto is the heart of an engine. Here’s how magnetos are tested at the factory cn a production basis it was necessary to drain all oil from the engine, remove the gaso- line, and treat the inside of the engine with a heavy oil. The car should be stored absolutely vertical in order to eliminate strain. The air-pressure in the tires was reduced to about thirty pounds. If the ceiling of the warehouse is very high, it is possible to store cased or crated goods on the floor and to stand the chassis on top of these. All parts should be well oiled before storing. Cae A i ate SS et sderadtualdicadl miata’ 7 ca a ar hat a get key : Be ene yer ares a g - F 5°78 “4 ; « Popular Science Monthly What’s Wrong with the Magneto? -. Test It Scientifically T has been said that the magneto is the heart of the automobile, since without - the proper spark, generated at, - exactly the right instant, the engine . is of no avail. It is important, therefore, that the magneto must . be correctly. adjusted before it is installed. in a car.. In. the testing apparatus here shown, the magneto is: first of all. mounted on a small test stand, with . the rotor shaft connected rigidly at the rear end to a large metal disk; . Around the circumference of the disk are marks indicating the proper - breaking points for different types of magnetos. The fact that the marks on the disk are several inches away from the center of the magneto rotor” -shaft serves to magnify the slightest’ error in the time and position of the spark- ing period. At the same time, the duration of the spark is tested by a buzzer bell. This eight-cylindered engine has hung up one world’s record, and will shortly go after others Eight Cylinders n'a Row \ HE engine shown above is attracting a . geod deal of attention throughout the United States, for it made the world’s record for ten miles in five minutes twenty and one tenth seconds. The cylinders are set vertically and in a row. In spite of this fact, however, the total length of the engine is one and one fourth inches shorter than that of the small Buick “Six.” With 296 cubic inches capacity the engine develops 150 horsepower at 3400 tions per minute. revolu- Its weight is about 475 pounds, or a trifle more than three pounds per horsepower. As you will note, this engine, therefore, closely follows the aviation engine standards. The valve action is of the overhead type and This is how the army stored trucks and auto- mobiles. Valuable space was utilized, which saved the building of gigantic werehouses is operated by a single cam-shaft on top of the engine. Heretofore all eight-cylindered engines have been made in the V-block type.

Page 15

as of A tent that folds into a small bundle Off goes the runabout, with its load arks - on the running-board and expands of logs. Better be sure your car is a way into a seven-room house when set up heavy one before you try it, though otor” , test : : Camping by Automobile ADE out of balloon silk is this complete “TUT you promised to deliver that load the fold-up house with four bedrooms, a of logs-today,” came the voice over dining-room, a living-room, and a garage the wire, “and I must have them or lay _ large enough for two Fords or one larger car, off my entire gang of carpenters.” y all under. one roof. FLOOR PLAN “It simply can’t be done,” replied the As shown in the plan view, the garage is owner. ‘‘All my horses are away, and— in the center, flanked on one side by two con . — But wait; I have-anidea. I'll get those \ bedrooms and the dining-room and ‘on the “ee i ROOM. ; "rom logs there as per schedule. Good-by.” sre by the Aacenge nt bedrooms ~— ie s4xeo|" “incnes SAX 86 Going out into the ir a om se iving-room. One or both cars may be taken ! expensive new runabout, all spick an out-for errand duty without disturbing any = 95] capacz cans pone Sees On spain. Heaving a heavy sigh, he coupled . other part: of the tent except to open up the SOIXGrtOm. ~ Stace ee it in front of the big wagon filled with logs, 4 tent flap. : — - a and: let in the clutch. The runabout took The tent is twenty feet square, and the ROOM ( phe ROOM up the load and ambled easily toward her bedrooms are large enough to accommodate oreo 132x80 y 54 X80 destination. While we don’t advise making a regulation folding cot. The entire tent pon wane a practice of this, may be folded up into a small bundle and age sgh ie it might be re- conveniently carried on the running-board pon fi Po membered in an of the car. a garage for the car emergency. Another Traction Rim for the Motor-Truck N many of the rural sections of the United States, mostof them havebeen complicated. 3 motor-trucks often have to be kept in their garages, even But a new traction rim has just ; when there is plenty of work to be done, on account of been invented that can be attached the poor condition of the roads. While many devices to any standard-size motor-truck ti have been inventec. to overcome this great economic waste, wheel without making any changes 4 in the wheels or the chas- the , : ; sis. The new rim may a be attached to either the inside or the outside oy of the wheel, or both. fe get + - oe rth Furthermore, the rims the other for chain- oa may be applied and re- qriven trucks x.” main permanently in — place, since they are of smaller diameter than the “ed rubber tires regularly fitted on the wheels and (75 do not come into contact with the road surface ner until the truck strikes a soft spot. _Then the a rims, which are provided with crosswise lugs or a re cleats forming an integral part of the rim bands, come into action and pull the truck through oi the soft earth. The outside diameter of the rim le is generally about four inches smaHler than the in outside diameter of the rubber tire when worn all down to the point where it is ready to. be taken 1es A new type of traction rim which attaches on both sides of the . ff, so that there is always a clearance of over two he truck wheel rim. It is designed primarily for bad roads and inches between the rim surface and the hard- places where the ordinary truck wheel cannot obtain traction surfaced road. 35

Page 16

' ate ii all t Popular Science Monthly These Canaries their gilded cages The Cat Cannot So well guarded From the over-curved branches of the artificial tree-stand below hang an Italian —_ and a mnt ene sein WM: ty i “Swing me high, swing me low,” sings the bird, after the popular song; its cage may be adjusted up and down Egg-shaped, the reed cage above cracks open like a cooked egg when the cage is to be cleaned PM Q{VAWw@.° 7}! yh Wy Mlildddimua . MUOTITOER A Uy Vy Yh Vay ' tte, Wn, jl Mitty dp i “Ulttyysy t img a, WS lineal SSN MOM Le AOA AQWWN. WOWOWWWWWQWBW SOA “Room and bath, please,” was this : : : bird’ : A slit perch filled with medica- ird’s order He got it, as you we ted cotton destroys the mites A bungalow within a bun- Hsioush water to k Siem galow—for the bird; the > Ry oe : vou bird copied ee . little fence around it keeps Something = ‘4 ata si should you go away / arn the seeds from flying out ~ tin peo ll “4 a 6 Hen for several days 4 aw 2: when so _ inclined / hs ; ae a F| e Neng He loves his dinner-bell; it tinkles when he pecks at it SONAL NG OLS EASELS ARAL fore SSS N WRAY BAKVWQ{QU ELLE. A heavy metal cage on a’ metal The perch-puller for cleanin ur- stand—all for one small bird “$i “ om poses; it looks like a tooth-puller 36

Page 17

Here Comes the Cake Bride, .bridegroom, horseshoe, and flowers, all assembled in readiness for the fatal moment Sixteen brides, eighteen bride- grooms! Two will be left wait- ing at the cake! Each little figure is molded..in halves —front and back; then the two halves are stuck together

REA AAA % Z Y

Pairing them off. Note the re- jected bridegrooms, overcome with grief, swooning on the ground They are wed under a good-luck horseshoe. “They need it,”’ say the cynical. The horse- shoes are made of sugar, starch, and gum

“ey / Ye "emma Tying the leaves so they won’t fall down —that would spoil the sugary wedding SSSA a" in pull

Lae SONTAG LAIT Ss xy g 3 Res? . “od q

Ze

sa ii,

Not bandaging— bridal veils. To each bride is assigned three inches of net, and this is glued to her paste head To each pair is given a dove; it hovers over their heads for a good omen as they stand on top of the cake Just before the wed- ding supper: they are almost ready to stand on the slippery icing " so AQQnsy <4 SOMATA % 4 & nL eeeec cc occccceccecea

Page 18

The gatelike structure in the center of this partly completed tank casting is used in shaping the walls of the mold The flames are caused by the burning of gases driven out of the clay by the terrific heat of the molten iron Popular Science M onthly Making Gigantic Hollow Castings Manufacturers demand big equipment j : SS ITH the unprecedented growth of industria] chemistry in the United States has come a steadily increasing demand for larger and larger equipment. Chemical manufacture on a large scale requires, among other things, cast-iron tanks, kettles, and bowls of enormous size, the casting of which is a task of considerable difficulty even for modernly equipped iron foundries. One of the accompanying pictures shows the partly completed outer mold for the casting of a tank nine feet deep and fourteen feet four inchesin . diameter. The gatelike wooden structure at- tached to the center pin is the sweep, which is used for shaping the cylindrical walls of the mold. The ground around the mold is filled in with cinders and is well ventilated with pipes. The walls of the finished mold are torch-baked, and are finished off as carefully and smoothly as the sur- faces of the core, orinner mold. After the core has been properly centered and weighted, the mold is ready for the metal. The channel for the inflow is connected with the base of the mold, and in this way a minimum amount of abrasion of the earth walls is assured. The other picture shows the pouring of the molten iron from a thirty-five-ton ladle into the unusually high riser of the big mold, only the top of which is above the ground. The small flames shooting from the joints of the riser are caused by the burning of the gases driven out of the clay by the terrific heat of the molten iron. The ladle with the iron had to be lifted by a crane and the man at the wheel in the illustration is regulating the flow of the metal. Testing Steel by the Spark It Gives Off OR many years most of the left-over pieces of high-speed steel tools, cutters, and other implements have been thrown away, yet this metal is very expensive because it contains tungsten. Within the last three years a method has been devised by which most of this valuable scrap is recovered. In this process each piece of scrap is applied to a grinding wheel of special composi- tion, whereby certain kinds of sparks, depending on the composition of the metal, are given off. Testing scrap steel. The sparks given off against a wheel te]l which are high tungsten and which low

Page 19

ial er Ze cS, of or October, 1919 Tracing Earthquake Records by Rays of Light A new recorder of earth tremors, which eliminates friction, has been invented at Kilauea Observatory By L. W. de Vis-Norton, of the Kilauea Volcano Observatory ment that has succeeded in eliminating the element of fric- tion, a very distinct advance in the recording of earth tremors must be credited to Dr. T. A. Jaggar, vol- canologist in charge of the Kilauea Voleano Observatory in Hawaii, aud to his assistant, Dr. Arnold Romberg. By doing away with the usual method of employing a stylus to trace a line upon a revolving drum covered with smoked paper, and by employing a system of photographic registration, some very remarkable results have already been attained, though the instrument is still susceptible of con- siderable improvement. | Record Made by Light Ray ‘ The principle of the new idea in recording is that of an_ accurate record, made with a ray of light from a tiny straight-filament electric bulb. It was necessary to work with material at hand in the observatory, and one of the four regular seismographs in use was therefore dismantled and re- constructed on the spot. The lamp was set up at a distance of 150 centime- ters from: the ' end of, and in - tae line with, though slightly above, the arm of an Omori 100 - kilogram horizontal pen- dulum, the tip of the arm be- ing fitted with a magnetized horizontal needle. An or- dinary light B: the construction of an instru- SENSITIZED it A record by the old method, made by a writing-pen on’a drum covered with smoked paper. The perpen- dicular marks show intervals of oné minute. The magnification is small, the phases of tremors indistinct mirror, with a diameter of twelve milli- meters, was then firmly fastened to a vertical taut silk fiber, held on a post standing on a concrete table; while a second magnet was attached to the back of the mirror in such a manner that it lay at right angles, with its north pole adjacent to the south pole of the arm magnet. Projected in Ordinary Camera Lens In this position it will be seen that horizontal earth displacement would move the pendulum and the mirror supports, while the frictionless mag- nets rotated the mirror around a vertical axis in response to inertia of the mass. The light ray was projected with an ordinary camera lens, of about thirty meters infinity focus, upon a long strip of sensitized film clamped to the drum, which was speeded up to revolve "ea at the rate of thirty-three millimeters per minute. Attached to the long arm of the pendulum SILK THREAD In this instrument de- vised by Dr. A. T. Jaggar and Dr. Ar- nold Romberg, of the , Kilauea . Observatory in Hawaii, earth tremors are recorded by a system of photo- graphic’ registration ; remarkably accurate records - have been made, although the machine is still suscep- tible of improvement ¥ "4 was an openwork metal box sus- pended in a vessel filled with oil, whose effect is to strongly damp out mechanical vibrations, but which leaves the mirror extremely sensitive to earth movement, while a clockwork timing arrangement shuts off the light once each minute, with a longer period at the end of each hour, thus making a perfect timing record upon the photo- graphic paper. While, owing to imperfections in the available mirrors, the. optical work is as yet in its earlier and crude stages, the magnification and openness of the records obtained are truly remarkable, and a-vast improvement over the old stylus: method of registration. . While the records are, in: -sOme respects, similar to those of the Galitzin in- struments, the finest microtremors are shown in a continuous wavy line, while the slower microseisms group themselves rhythmically, the whole series showing, for the first time, longer wave-movements, which will. be made the subject of later investigation, these move- ments, under the old method, being indeterminate, irregular, and prac- tically illegible. Many beautiful photographs of even the most rapid movements of small local earthquakes have been obtained, together with a very beautiful seismogram of a strong, distant.shock. The « difficulties _ of damping, friction, magnification, opening therec- ord, and time- marking have already been overcome, and the resulting seismograms are ‘clear, transparent negatives. 4 are oe a Ba ess. a ee | In the new method by photography the time marks are indicated by small breaks in a con- tinuous line. A study of this record of a normal period of usual earth tremor is of great interest

Page 20

A Tire as Tall as You cs [- a thirty-one by four inch tire costs thirty dollars; what will one: of the monsters above.cost?- And what manner of car will-they- be used on? Such are the questions. that rise’ in your mind when you look at them. They are -nearly:as. tall as. the men who handle them. Later on they will be attached to a Handley-Page airplane, and then they will seem almost too small to support the giant airplane. The strides that airplane manufac- ture has taken in the last ten years are readily realized when you stop to compare the Handley-Page ma- chine of today with the little ‘“De- moiselle”” plane that hovered over the first aviation fields in the days of Moisant and Hoxey. Popular Science Monthly ; Look Before You Speed p EtVING desperately in an attempt to overtake the leaders, Roscoe Searles, in an automobile race, although not familiar with the course, thundered up “Death Curve” at Santa Monica, Cal., at a high rate of speed. Cramping his wheels and locking his brakes, Searles tried to skid the right- angled turn ; but so great was its momen- tum that the big car swerved only slightly, leaped the sand-bag barricade, narrowly missing a eucalyptus tree, and crashed to the ground, crushing one of the rear wheels. The crushed wheel acted as a drag, and finally stopped the car with its hood a few feet from the steps of a bun- galow. Neither Searles nor his mechanic was injured. Ane the photograph caught him in the act! A Swan for a Hood NDER the calm exterior of this graceful swan lie cylinders, spark plugs, oil, grease, a: motor, and all the other things that the hood of an auto- mobile usually covers. The swan is playing hood for a wealthy man living in India, whose ideas of motor beauty- are most peculiar. On the front axle are a pair of gargoyles, placed there to emphasize the swan’s grace. Out of the mouth of the swan comes a warning hiss instead of a blast from a horn. The Smallest Post-Office’ LTHOUGH only five by five by seven feet in dimensions, out- side measurement, you will find a postmistress stationed on the inside of the post-office shown in the picture to the left, for the transaction of any kind of post-official business negoti- ated at any of the larger branch offices at the na- tional capital. The diminutive office is situated at the corner of | F and -9th streets, North- y west, Washington, D. C. = / The business of selling “= stamps and mailing letters is here carried on in a most efficient fashion.

Page 21

this ark the uto- n is ring uty: axle e to mes rom by ut- la side ure’ any oti-' ger na- of th- ing ers ost October, 1919 The Top that Winds Itself Up ERE is a top that winds H itself and spins on both ends. It works on the same principle as the see- saw. The peg top is surrounded with a metal knob. One end of the string is attached to the stem. By holding the metal knob between the fingers, and pulling the string out two thirds of its length and then letting it hang loose, the string rewinds. After doing this a few times the speed will be so great that the top will spin on either end. He Must Anchor | gpecngi ed topographical surveying in Alaska has been done with the help of the panoramic camera; but under the condi- tions usually found among high mountains it is probable that the topographer will long have to do his sketching in the old-fashioned way, by hand, and in doing so must often face such difficulties as the topographer in the picture below is up against. This surveyor is working on a peak in the Yellowstone country, 10,500 feet above sea-level. wind at this height is so strong that he has had to tie and weight down his working table. been forced to lash one leg to a projecting spur of rock, to keep himself from being blown away from his job. The day is not far off when map-makers will sail comfortably to their work in a dirigible and photograph the wilds at their ease. Photographic map-making was done successfully during the war. By piecing together hundreds of pictures taken from balloon or airplane, maps were produced so rich in detail that _ it would have taken a skilled ‘- chart-maker years to produce their equivalent. But at present a small dirigible costs twenty-five thousand dollars, and legs are © Brown & Dawson It’s the Silk-Cotton Tree HAT is your mattress made of? If it is not made of expensive hair. or cheap straw, it may easily be in the in- between class known as the silk-cotton fiber mattress. Silk-cotton fiber grows on the curious tree shown in the picture above. It is contained in the fruits that hang from the branches. Though silk-cotton is usually used as stuffing for mattresses and cushions, it is sometimes woven into a loose, coarse cloth. The fiber is short and silky in ap- pearance. The trees grow in the tropics. Himself to the Mountain Some Bird! T was a case of “look like a birdie’ and not “‘look at the birdie’ when this picture was taken. Perhaps you wouldn’t be fooled by the straw skirt and the artificial bird’s head, but the Munshi who is wearing these strange garments isn’t interested in you; he is trying to fool a bird that he wishes to catch; and, according to his previous ex- periences, he will do so. Rex! What Time Is It? ‘THE dog will have his watch, says the lady below; but we don’t see what use it will be to him unless he learns the whys and wherefores of time. The watch is not intended for use, but for beauty, scornfully says the same lady. In fact, the watch is not a real one. We give children toy watches, so why not give them to dogs? As to the dog’s delight over his new possession we know nothing; but, since he is a full-blooded Boston bull terrier, we fear he may not be overjoyed. ©Press I!lustrat- » ing Service It’s a Native of Africa He is also above the clouds. The The Munshis are a negro race living in Bassa, which is a province in the British protectorate of northern Nigeria. They are an As an extra precaution he has even industrious race, and are great agriculturists; but they are very quarrelsome and are said to be always looking for trouble. What is more, they smuggle in spirits and drink them!

Page 22

Popular Science M onthly _ Mummifying Fruits, Flowers, and Vegetables = — —— ° — N a basement room in Los Angeles @ magician is at work. He is putting fruits and vegetables into tall, glass-stoppered jars, to keep‘for years to come, and canning lilies and roses and bridal bouquets. His tables are loaded with the finest of everything that California can raise, and his shelves, lined with huge containers, will soon hold a complete assortment of the state’s products. For eleven years W. H. Fowler has been in this delicate business, all the while experimenting as well as pre- serving. It is said that in the whole EAT, from time imme- morial, has been cut up primarily to please the eye. When the United States entered the Great War, at a time when every cubic inch of shipping space was precious, it occurred to the Quartermaster- General of the Army that perhaps the methods of butchers ‘could be improved upon. There was too much waste, and bone. The result of the investigation was the development of what is now called the “natural guide’ method of separating or tearing meat along the lines of natural cleavage. The bone is removed, and most of the fat. The Army abroad received this natu- tally separated meat in burlap bags. Steaks, chops, and tenderloins were put Each kind of flower demands a special chemical solution of its own. The right one will preserve it for many years It is done by “processors,” of whom there are only fifteen in the world world there are only fifteen “‘proces- sors,’’ and that this man has discovered chemical secrets that the other four- teen would give much to know. To outsiders the “processing” is a mystery. We are told that no heat and not a drop of alcohol is used in the wonderful. displays we have seen at various fairs and state-boosting. ex- : hibits; that the jars are not air-tight; that the preservatives are rank poison; and that the treatment of different products varies according to their kind and nature. Each color in the flower world requires a different chemical, The Army discovered the “natural guide” methods of cutting up meat. It is up to the packers whether the old wasteful methods can come back in one bag, stew meat in another, kid- neys and livers ina third. Thus about thirty per cent of the shipping space was saved, not to mention the wastage that had come to be accepted in the packing business. Are we going to keep on separating meat by the “‘natural guide’ method? 42 The peaches in these jars are, alas! not good to eat, for they are preserved in poison. But they will last for many years blue being the hardest to preserve; and, stranger still, flowers of one kind and color—-red roses, for instance—do not respond to the same treatment. It is as if each variety had absorbed different elements from sun and soil. Fruits, vegetables, and flowers that are porous are “easy,” Mr. Fowler says; but the solid ones require long, patient labor. Apples take from six months to a year, and during that time must be dosed frequently. An exact record of each jar must be kept; the ac- cidental destroying of a bluebell record meant the loss of a valuable secret. Or are we going to adhere to the old wasteful methods? It remains for the packers to decide. A butcher ought to be able to take a two-pound tender- loin steak from the ice-box with no more exertion than a grocer now takes down a can of to- matoes from his shelf. The Army taught hundreds of men the “‘natural guide’’ method of sepa- rating meat. They were taught in special schools. The skeleton of a cow was exhibited to them and instruction was given by an experienced man in the proper way of quartering the. animal and then tearing the meat along its natural lines of cleavage. Hotels and restaurants, and butchers, why not offer these men jobs?

Page 23

October, 1919 When the Burglar Goes a-Burgling o ANDS up!” says the hold-up man. “Now give me _ the money I see in that drawer,” he continues. The bank cashier grabs it glee-. fully; for as he takes it out two con- tacts above and below it come to- gether and close an electric circuit that opens a trap-door on which the burglar is innocently standing. Forthwith the burglar lands in the trap below, and is later fished up by a policeman. “Fished up” is no idle jest; for the cashier has at his right hand a wheel which, when turned, will open a valve in the compartment below and flood it with water. Of course, in using a device like this there is always the danger that the cashier might accidentally pull . out those bills when the bank’s best customer stands before him. As the cashier pulls out the money two contacts touch each other and close a circuit, opening a trap-door Electric Lights for Goldfish OW would you like to be a goldfish? AIR PIPETO BLOWER | ON TRUCK t AIR SUCTION PIPE You rake the ashes into a pit, and that is the last you see of them; a truck with a blower on board will come and draw them away by means of a pipe line The Pipe-Line Ashes Express HINK of the cost in labor, bles are no longer necessary, for a ash-cans, and conveyors in pneumatic conveying system has been getting ashes to the ash-dump; devised by means of which you need and think of the inconvenience only rake your ashes from the furnace that ashes cause. But these trou- into a pit in frontof it. That is the last you see of them; in a few days they will disappear. On the level of the floor of the pit there is a pipe line having several holes in the top through which the ashes will drop. This pipe line continues on and upward to the street level. At regular intervals a large ash-removing truck will stop at this pipe. Pipe and truck are connected. A blower on board is attached to the Shaped like an GLASS LIGHT inverted elec- CHAMBER tric light globe is this aquari- um, to be hung in the window REFLECTOR Fine, you say; nothing to do but eat, BOwL truck motor, and soon the ashes sleep, and swim in comfort. But don’t be too sure. Rudolf Eicke- meyer, of Yonkers, has just in- vented a new ornamental aqua- rium, which has an electric light in the center surrounded by a trans- parent cylinder of many colors. The light is turned on, the cylin- der revolves, and the goldfish goes through all the colors of the spec- trum. He may be sleeping peace- fully when his owner suddenly decided to show him off. Another design calls for an aquarium shaped like an inverted electric light globe, to be hung in the window. The sunshine, the gold of the fish, and the green of the plants form beautiful color effects. fly upward and land in a bin in the truck. As the ashes in the pipe are sucked up, those in the pit fall through into the pipe, and gradu- ally the pit is emptied. Off goes the truck with your ashes. Simple? Both simple and cheap; for the cost of this service is about one third that of ordinary ash- removing. When the truck leaves your building, it draws up alongside of another and much larger truck stationed near by. The ashes are ; dumped from one truck to the other. Thus the smaller truck containing the blower is able to -_ proceed to another job. Whenthe The gold of the fish and the green of the growing large truck is full, it sets out for plants are beautifully brought out by an electriclight the main ash-dump. 43

Page 24

As for the leopard, your mother will make him out of some yellow cloth. You can daub on the spots of black paint with a brush A blanket that stretches down to the floor, a five-foot pole, Jim to play the part of the front legs and Harry the back legs—that’s the giraffe. But there must be some rehearsing if the front legs are to know what the rear legs are doing The untamed, man-defying beasts from Africa that already have killed two trainers and have decided to kill a third next week. What circus could possibly succeed without their presence? 44 Popular Science Monthly ‘ Jerry has a hard time of it playing the donkey. He’s got to keep the sticks in the front legs moving and raise all the laughs he can. And if the clown kicks him in the ribs—well, he must bear it And. here’s the supercilious camel. Don’t try to ride him. You can see what is likely to happen, since his hump is a mere matter of two heads If you want to make a horse, use some barrel hoops and laths. The head is concocted out of pasteboard; the tail is an old rope with frayed ends

Page 25

Ly October, 1919 Greatest Show on Earth let’s get up a regular circus Here’s your ringmas- ter’s hat, Bill—made from an old derby, some cardboard, and enough black paint to make it shine. As for boots, Bill, just fasten some red cardboard around the top of a pair of old rubber boots Of course there must be a girl dressed up as Columbia. Her mother can make the costume shown here The overpowering giantess (engaged for this performance at t-r-r-emen- dous expense) owes her stature to a pair of stilts that any boy handy with tools can make for himself. The stick prevents her from falling There’s simply got to be a roaring lion. No king of the jungle can look fiercer than you, Jim, draped in the fur rugs from the parlor. You'll have to make your own head Dress up your sisters as Teddy bears and they’ll make a hit. The suits are made of white bear cloth Here comes the ostrich tearing along. It’s well for Mattie inside that sister Sally doesn’t recognize the tail feathers that came from her hat. Mattie has a very exciting time of it chasing a dog around the ring Nail the tight-rope to a board laid on two bar- rels. The level of the rope should be that of the spectators’ eyes. Every one will. think that you are a Blondin, and you will be safe

Page 26

Popular Science M onthly be SINE OPN Se Cane een SSeS “i eh RR i BORE ay Now the bedroom is coming into its own This one-room apartment may be turned into four rooms by a revolving platform which contains a kitchenette, a bed, a dresser, and a library desk. The platform is revolved by hand The room was a library but is almost a kitchen Presto! The Kitchen Is a Bedroom NE room, a revolving platform, and you have the makings of a four-room apartment. This contribu- tion toward lowering the high cost of rent comes from Pasquali Cimini, of . Buffalo, N. Y. Mr. Cimini divides the revolving platform into four quarters: in one he puts a folding bed; in another a desk; in a third the sink, stove, ironing-board, and cupboards of a kitchenette; and in the fourth a dresser and a clothes closet. The platform is mounted on rollers, and may easily be turned by hand. All the plumbing and electric wiring terminate in a central column that revolves with the platform. When the bed is down the kitchen is accessible from the hall and the F inding the Force of Felt T the right is a resiliometer, 2 machine that measures the re- siliency of felt. You place your felt on the plat- form, and then let down the presser foot until i€ touches the felt. The presser foot.is attached to a dial. One revolution of the pointer means that the presser foot has moved one tenth of aninch. Asmaller pointer registers complete revolutions. You read the dial when the felt is at its normal thickness. Then you release a spring catch which holds in place a weight at- ‘tached to a quadrant. As the weight goes down the quadrant moves forward, and a bar comes down and presses on top of thepres- serfoot. The foot sinks into the felt tothe limit of the felt’s compression. You now pull back the quadrant, releasing the pressure. The ex- panding felt will force the presser foot up, and you immediately read the dial in order to get the amount of resiliency. dressing-room from the bath-room. In the central column is a ventilating duct -:hat: swallows up the kitchen smells and hat airs the bed while it is folded up. A separate duct takes care of the garbage-pail compartment. The plat- form is six feet ten inches in diameter, and is seven feet six inches high; it weighs something less than seven hun- dred pounds. The platform, frame and partitions are all strongly con- - structed of steel. Thus, instead of having one large room and bath—generously thrown in by most landlords—you will have four large rooms, though, of course, not all at the same time. You get up in the morning, fold up When the pressure is released the felt expands, and your gage will tell you how much 46 your bed, and swing the platform round until the kitchenette comes in view; fix breakfast, eat it, clean up; swing your platform once again, and read the morning paper comfortably in the library. The bath-room is so arranged that it opens out on the platform, too. Thus on wash-day the kitchenette may be swung into the bathroom and the soapsuds will splash harmlessly on a tiled floor. Above you see the platform in its different stages of revolution. The center picture shows plainly the possi- bilities of one large room when used as a bedroom. One might say that this invention will literally cause revolu- tions in apartment construction. Your Hard-Working Heart HE human heart beats seventy- two times a minute, one hun- dred and four thousand times a day, thirty-eight million times a year. If a person lives up to his seventieth year his heart-beats— estimated according to the various averages during life—will approxi- mate three billion beats. At every heart-beat of an adult about five cubic inches of blood is forced out from each of the ventri- cles into the lungs and into the rest of the body. In other words, with every stroke of this bodily pump about ten cubic inches of blood is expelled from the heart, which amounts to forty-three cubic inches in an hour and to a million cubic inches in a day. As anillustration of the work done by the heart, the powerful pump of the left ventricle performs during twenty-four hours an amount equal to raising a weight of. one ton to the height of eighty-two feet.

Page 27

its he as lis October, 1919 What of Tomorrow’s Flying? Is the airplane safe? Can you fly where and when you like? What’s_ the cost? By Waldemar Kaempffert and Carl Dienstbach HEN the manufacturers of Wieirvianes turn to the public for support, they are met with conservative skeptical questions: “‘Is flying safe? What about these acci- dents?” The manufacturers reply with statistics to prove that flying is no more dangerous than automobiling, that the blacksmiths and ‘carpenters who built the first flimsy machines have been supplanted by engineers who test the wood, steel, and wing fabric used in construction, and that all the resources of modern science are tapped to build an airplane that is safe. When bombs were dropped on Paris, London, Mannheim, Freiburg, and Constantinople, and whole flocks of raiding airplanes performed their grue- some death-dealing mission with clock- like precision, who can doubt any longer? As for safety, diplomats and generals, whose lives no nation could afford to risk, were transported with ease and despatch through the air. The world has literally been bombed into conviction. ‘‘The war has en- larged our mental horizon,” as one British technical periodical put it. Peace-Time and War-Time Flying The men who guided the bombing and fighting planes over -the battle- front were in a far more precarious position than any peace-time flyer will be. They were literally flung into the air and ordered to perform what was expected of them. There were no prepared landing grounds. And yet, despite this handicap, war-time flying was safer than most of us suppose. Major-General George O. Squier, in a paper read before the American Institute of Electrical Engineers, stated that of all the flying casualties only two per cent were due to anti- aircraft fire from the ground or from enemy machines in the air and eight per cent to faulty construction. And the other ninety? Traceable directly, he assures us, to negligence, in- competence, or ignorance on the part of the flyers. If pilots are properly trained how much safer will peace- time flying become! Moreover, the campaign in the air over the Italian front must have con- vinced any skeptic of the airplane’s You will be as comfort- able in the nacelle of a fast long-distance com- mercial airplane as you are in.a Pullman car. Luncheon will be served as it is on a railway train. You will travel in luxury. Fat men must pay more than thin men safety. Among the mountain ranges where Italian and Austrian aviators fought there was nothing that remotely resembled a smooth, safe landing green. And yet, neither Italians nor Austrians hesitated to fight or to fly over each other’s territory on bombing . expeditions. The last piece of convincing evidence was presented when the fighting pilots literally flew to the other extreme; in other words, when they supported the charging infantry by skimming over the ground and pouring a hail of machine-gun bullets on,the enemy in his trenches. What if engines had failed then? There would have been only a shell-torn No-Man’s-Land on ‘which to alight. Yet we have still to learn of any wholesale calamities that befell these low-flying machines. And then, the night flyers—what shall be said of them? They knew only the direction in which they were to fly in order to bomb an ammunition dump or a munitions factory—nothing of the ground in the terrible darkness below. If perilous missions such as these can be carried out in safety, who shall say that when all the earth is at peace, when cities are ready to de- spatch and receive the winged messen- gers of the air, flying can never take its place in-our mercantile life? The truth is that the airplane today is in much the position of the steam- ship and the locomotive a century ago. Prejudice alone must be overcome. 47 Elaborate and complicated wharves had to be created before the steamship could become of mercantile impor- tance. Rails had to be laid, stations built, round-houses and repair-shops erected, before the steam locomotive could play its part in the transporta- tion of passengers and freight. Simi- larly, a great organization must be developed before the flying-machine shall be able to realize the dream of those who would span the Atlantic in a day or wing their way in a few hours from New York to Chicago. Needs of the Airplane The flying-machine traverses the pellucid air unhampered by hills or poor roads. But that is not enough. Before commercial passenger-carrying airplanes appear in large numbers, before airplane touring shall become as common as motoring, the face of the earth must be “prepared. Although the flying-machine is a thing of the air, it must start from.the ground and it must alight on the ground. Here and there are a few army aviation fields. More, much more, must be done. Every civilized coun- try must survey itself with a critical eye and note what localities are best suited to serve for landing and alight- ing. Between New York and Chicago,

Page 28

for example, prepared aviation: fields should be found at intervals of not less than one hundred miles. Now, to dot a whole country with hundreds, even thousands, of aviation fields is a task of such magnitude that only a government can accomplish it. Mindful of this, the United States Army has already addressed itself to the task. Chambers of Commerce all over the country have been asked to study the country around their com- munities and to indicate those local- ities that seem best fitted for land- ing fields. The Government knows exactly what it wants. It has sent Chambers of Commerce plans of aviation fields and of the sheds and repair-shops to be built. The preparation of the ground will make the flying-machine abso- lutély safe. Automobile engines now stall in the middle of the road. Flying-machine engines also stall in the air.. The passéngers of a touring car have only to step out on solid ground and walk if ‘the engine should fail them; but, in a similar predicament, the man in the air must glide down to the ground. ‘ The Higher You Are, the Safer Paradoxically enough, the higher you are in a flying-machine the safer you are. When an engine balks at a height of a mile or so, you cast your eye about for a smooth piece of turf. You may glide from three to five miles by skilful handling of your craft. Is it not obvious that with Govern- ment airdromes everywhere you ‘ will be sure to find an alighting place? The flatter the angle at which a flyer alights, the safer for him. Hence the field must be open from all sidés. If it is fringed by trées and buildings the flyer must plunge down too steeply for safety; it will be difficult for him to flatten out at the right moment. The difficulty of landing at high speed has probably been greatly exaggerated. We have only to consider that fighting flyers in. their high-powered machines landed safely at sixty miles an hour. If the ground can be ap- proached at a very flat angle the pilot has less to fear from impact with the solid earth at high speed than from the momentum that must be expected in taxiing over the ground. ; The flying-machine needs brakes of some kind. . Why not apply the usual band-brakes to the wheels? Because a machine that is held back below its center of gravity will somersault at high speed. Perhaps the solution is to be found in some method of forcing the tail down with tremendous leverage while . the brake is applied. A horizontally mounted propeller at the end of the tail might. answer the purpose—a pro- peller which, during flight, may be held parallel to the fuselage, so that the head resistance is not increased. It is even conceivable that the self- starter of the engine may be used to drive the horizontal propeller during the short period when its services will be required. It may be urged that this problem of holding the tail down while the brakes are applied is not easily solved. It entails, for instance, the use of a device to prevent an increase in the angle of incidence of the wings, so that the machine. may not rise from the ground in the effort to check it. PHA WW WNW —*EnddsSs RID. SSSA ANS Popular Science M onthly When landing and launching grounds are to be fourid everywhere, it will be possible to design the small inexpensive airplane—the machine that can be kept in a kind of garage and trundled out as readily as if it were the cheapest of Detroit automobiles.. Capacious - fuel-tanks will be unnecessary. It will be possible to refill the tank every hundred. miles, if need-be. Because no extraordinary feats will be de- manded of it, the engine’ need not be of the enormous power demanded by the fighting flyer. Government Aviation Maps ‘ Maps, too, must be issued by the Government—maps to indicate the best route between two given points. WOMAN WW NMA AAA AOD w_ PE AD SOO WW wD DWH At night the aviator will be guided to his landing place by the beams of powerful searchlights directed upward, as well as by captive balloons to whose cables electric lights are attached. Nothing must be left undone to insure the flyer’s safety 48 (ALM LLL UU ALUUULU TOOL ALOXUUU TULL LLL LOU tt on MUON TLL Ld ccc heiddddhicddsdlsdddddddecdldsdshddddddddsddcaatccdd N w i

Page 29

era of air transportation is here, ’ the creation of an artist’s fancy, but is designed by an This means the careful exploration of the entire country from the air pilot’s point of view. Enormous as the task may seem, it is far more easily ac- complished than may be suspected. The army dirigibles have only to be pressed into service—craft that may fly as low as they please and photo- graph at leisure the territory below. Miracles in photographic map-mak- ing were performed during the war. Similar miracles must be performed to chart the country for the pilot of the future. His map must indicate the meteorological characteristics of the region over which he flies—must tell him the direction in which the pre- vailing winds: blow, what invisible atmospheric perils are to be avoided, how high to fly over a given region, and the hundred and one facts that he must’ know in order to reach his destination quickly and safely. We talk a good deal about the weather nowadays; we will talk far more about it when a whole people takes to the air. The Weather Bureau must prepare to extend its activities. Its local reports and maps must be even more practical than they are now; they must tell a man exactly how he must fly to any given point within a radius of one hundred miles. At present the Weather Bureau con- cerns itself but little with the influence of the ground; but it is precisely the The airplane builders, at least, are convinced that the This machine is not ate construction influence of the ground that makes flying favorable or unfavorable in a> given region. An invisible surf of air is dashed up against every mountain. A lake, a grove, a collection of build- ings, in a word, every protuberance, has its effect in forcing air-currents in this direction or that. And all these in- visible disturbances the Weather Bu- reau must visualize for the airman. Fog will be the only peril to be feared. But even fog will lose much of its terror when the Government has carried out its plan of establishing radio beacons all over the country, to extend its airplane mail service. Radio Beacons Will Help What is a radio beacon? Simply a station from which wireless waves are sent in all directions, to be picked up by the flyer lost in a fog or groping his way through the night. Part of its radio equipment is the direction-finder —a mere loop of wire that can be swung in any direction on a vertical axis. - ‘When the loop is turned in the direction of the oncoming waves. the beacons’ signals are received most clearly; when it is turned at right angles nothing is received. “I am Louisville,’ ‘I am Toledo,’ “I am Easton,” beacon .after -beacon will literally shout at regular intervals with the aid of automatic sending devices. 49 English firm (the Bristol Company) for actual immedi- To guide the navigator in a fog, captive balloons will be used—buoys of the atmosphere ‘ally illuminated streets at home. And hundreds of pilots in the air will hear and guide their machines un- erringly toward the particular beacon that is their destination. The commercial companies will surely equip their large passenger- carrying planes with such radio con- veniences. But what of the business man or the tourist who flies alone in a machine unprovided with such aids? Balloons will guide him—great captive balloons floating high above the fog and illuminated at night. Every land- ing field will thus literally rear its head above the clouds. The flyer sees the light and heads forit. He has but to spiral down around the cable that holds the balloon captive to reach the ground below in safety. Ground lights will make his landing safe. In his “Night Mail’ Rudyard Kipling suggested a plan that may also be realized in order to make flying safe at night. He drew a picture of searchlights throwing their gleams vertically into the sky—impalpable, luminous sign-posts that point the way when the night is clear. Whata wonderful spectacle will be presented to the man in the air as he flies from New York to St. Louis through the night! His lane will be as plainly marked-out for him as are his electric- For miles and miles he sees the long, stiff pencils of light thrust upward from the

Page 30

ground or great captive balloons each bearing a powerful electric light. A country road at night would bedanger- _ ous in comparison with an air-lane so painstakingly marked. The flying-machine is singularly plastic. As we know it today, it was molded to meet the exigencies of war; as we shall know it in the future, it will be molded to meet the demands of. commerce. It is adaptable. * The man who fought at a height of twenty thou- sand feet placed his reliance on an engine of enormous power, and on wings especially designed for... fast climbing.” The commercial pilot ‘will be less-exacting. What need is there for him to climb ten thousand feet in six minutes? What need has he of an extraordinarily high ceiling? He wants engine trustworthiness, and the builder of engines is prepared to give it to him by making the power-plant heavier and more durable than the army flyer demands. The war, curiously enough, has served to show us how the airplane may be used in a very practical way for scientific purposes. To fly over the enemy’s lines and make thousands of photographs of positions is the exact equivalent of mapping a jungle or a wilderness which may be penetrated only at the risk of life and the suffering of untold hardship. In a single day the Coast and Geodetic Survey could thus perform more useful work than it now accomplishes in months when it surveys remote islands in the Pacific or the wilds of Alaska. Fire-Extinguishing Bombs Already the Forest Service is plan- ning to use the airplane to detect forest fires and to extinguish them by dropping upon them bombs contain- ing fire-extinguishing chemicals. The Coast Guard will. find its task of locating and blowing up derelicts at sea reduced to a matter of hours when it enlists the seaplane into its service. - During the war the British dropped food into towns beleaguered by the Turks. Why may not bomb-carriers supply colonies devoid of roads or rail- ways with the material that they need? The Sahara Desert, now painfully and AIRPLANE 100 MILES ee eee —— aie! What an hour’s travel meant yesterday and the day before, tediously traveled by camels, becomes a kind of aerial navigable sea. The German raider Wolf, aptly named, used a seaplane to locate its prey on the ocean. Who knows but the seaplane may form part of the equipment of every first-class steamer? Exploring by Airplane _ With what ease will the airplane transport the explorer over mountain ranges, swamps, jungles, and deserts! The camera will enable the explorer to bring back a far clearer, far more ac- curate record of the country that he has traversed than if he had explored it on foot. In the uncharted districts around the upper waters of the Amazon river may be untouched re- sources of rubber. Who knows but the airplane may locate them? Not only locate them, but indicate how they may be approached by undis- covered navigable streams? British airmen have already thus begun to explore the inaccessible regions of Africa. Regular passenger trips are now made between London and Paris and between Paris and Brussels. Rome can be reached from London in twelve and a half hours instead of in forty- two as at present; and Marseilles in eight instead of twenty-three. From London to Constantinople the distance is but twenty hours by airplane, com- pared with seventy-two by rail. The machines planned for this service are vessels of moderate size equipped with three hundred horsepower engines. They ought to carry forty-four hun- dred pounds of revenue-paying load in addition to the pilot, mechanic, and fuel. The cost per passenger mile would be a little less than $2.75. There is no reason why the peace plane should not be far cheaper than the fighting war plane. Remember that the fighting machine had to be extraordinarily light. It was not in- tended to stay in the air more than two or three hours. But a limited amount of fuel was carried in order that its climbing ability might not be‘ im- paired. Even the amount of am- munition for its machine-gun’ was limited. The peace plane may be larger. This 7 £ AIRSHIP Popular Science Monthly ‘ means that strength may be attained more easily and cheaply than in the small gnat-like fighter. The acrobatic performances of the fighting pilot— his ‘‘vrilles,’”’ his loops, his Immelmann - turns, his barrel rolls, his falling-leaf drops—will play no part in the less thrilling career of the commercial] | pilot. Therefore outrageous demands » need not be made on the peace ma- | chine. All this tends to simplicity and cheapness of construction without re- ducing the factor of safety. Perhaps, instead of the multi-engine machine, we may have an airplane that has an engine used for flying and an auxiliary source of power to be utilized when the main plant fails. Who knows but this auxiliary engine may be driven by steam stored under pressure—a practice now followed in | many factories where fireless super- heated steam locomotives are used? — Certainly the multi-engine machine | would be far less economical ‘than a_ machine equipped with a single flying - motor supplemented by an auxiliary | engine. Will Commercial Flying Pay ? Will commercial flying pay? People asked themselves a hundred years ago: Will railways pay? Flying will pay simply because it is fast. Only the other day the owner of a great London department-store flew to Brussels in order to hold a conference with his branch manager there. He saved days in actual time and thousands in - money—so he later reported. Whenever the object to be gained - is dependent on the saving of time, it will pay to travel by air. It will be expensive, to be sure, to convey one, three or five passengers a distance of five hundred, a thousand, or fifteen hundred miles. What if the fare is two hundred. dollars, five hundred dollars, or even a thousand dollars, in comparison with the profits to be made in furthering an enterprise that means a return of perhaps millions? Who would not be willing to pay one dollar to have an important letter conveyed by air from New York to: Chicago in order to receive a reply the following night at the cost of another dollar? MOTOR-CAR HORSE STARTING 20 MILES BMILES POINT PEDESTRIAN 4MiLES eR A AR er 50 and what it will mean tomorrow

Page 31

ial ler le Ay he - on is od in - od . be e, of on od in be at 3? ne er to: of ec iF Tier Stamping “together the photo- October, 1919 The Stay that Stays the Ladder from Falling F the ladder slips from under you while you are paint- ing the house, you unfortunately come down after it, and are apt to get severely bumped, bruised, and painted. Perhaps’ Mr. James Maxwell, of New York city, has so slipped, for he has invented a “ladder stay’’ which helps a ladder to stay put. The stay is a metal rod resting on a rubber pad, which It is fastened in place by means of a screw, which is attached to the holder through which the rests on the ground. The ladder will not slip ‘from under him on account of the stay attached to the lowest rung; he is the inventor thereof rod passes. The holder itself is part of a_two- pieced tu- bular clamp that fits around the ladder rung and is held together by screws. It is screwed on tightly enough to keep its cen- tral position on the rung, and yet not too tightly to keep. it from revolv- ing around the rung for the purpose of adjust- ment. below it. motor. from the bins. Coal arrives by way of an elevator and a moving belt across the top and is stored in the four large bins An Elevator for the Coal-Bin zi LEAN Coal,” says the fence of the coal-yard shown above; and the bins just behind help to prove it, for in them some of the coal is stored—free from dirt and refuse. The bins are twenty-five feet in diameter and thirty feet high. They are made of two-by-four planks, held together by iron bands spaced twelve inches apart. of the four bins runs a moving belt. In unloading coal-cars, the coal is dumped into a hopper which is raised by a bucket belt to the top of the bins. The coal then moves along the belt on top and drops into the bins The power is suprued by a fifteen-horsepower Across the top Each bin has a chute in its side about eight feet from the ground. These chutes are used for loading trucks directly The trucks draw up underneath the chutes and the chute doors are opened. Who Are You, Anyway? AR conditions made it impera- tive to use the utmost caution in protecting the military and naval depots of the United States Govern- ' ment from spies and other undesirable During the war every employee at the United €tates army and navy depots was required to have a photograph button. At the right is the camera that made the photograph; it also ‘registered each person’s height and gave him a number graph, its cover, and metal back hostile intruders. In view of the fact that thousands of persons were regu- larly employed at these depots, and that hundreds of persons visited the depots daily on legitimate business, some method had to be devised to make strict supervision possible. Casual visitors were admitted on pre- sentation of a temporary pass issued by the identification bureau of the Quartermaster’s office. The card contained all ie foto Bre Fue wn Lota benny ENDCATION MARYS Sear ow forets ee weld F Bleck mow. Hm Doe necessary data for the positive identification of the bearer; and a similar card, containing in addi- tion a portrait of the bearer of the pass and his thumb-print, was filed in the office for reference and comparison. Menty De Y FU Name OF LAY mo Z at mene 39° Whaleleatl JY To all regular em- ployees button badges were issued, showing a picture of the bearer, his height, his number, and the index letters and wonarune number under which his record was filed. A specially designed ma- chine was used for stamp- 51 Casual visitors were required to have a pass containing data for identification—shown in the top picture. The lower card, carrying the thumb-print was placed on file ing the pin-badges, which had a metal back and frame enclosing the bearer’s photograph un- der a transparent cover.

Page 32

Popular Science Monthly Asatte tah liad hbase aastummaiaummeccccc” Uae tanateatapaa, ) How That Carpet of Carpets are woven very much. piano. Instead of a roll of the yard) perforated cards (they M. Jacquard, a French invent. forations automatically govern Photographs © Underwood & Underwood Left. Perforated cards (‘‘jac- quards”) control the weaving of the carpet’s pattern, just as a perforated paper roll determines what notes of music are to be played on a player-piano WWW MN NQ-sdQ_dMd/dM|TTH FHT THAT A es MAH LE Lec ccceeleeeceelceccellleitccxccaaccqccccnccZ0”5ncn00Oeun. Here is a big rug loom in action. Overhead A carpet loom is as automatic as a player- are the jacquards, or perforated cards, that piano. You adjust perforated paper cards, and the automatically control the weaving of the pattern machine weaves a carpet with the desired pattern e s} a+ waned. a} ; aa* Left: The carpet , ; — ea), is passed through a yererrenee™ a shearing - machine. iy bes cae € ; 190004 The revolving : tt. "eee knives cut off the : excess material Right: Spooling the colored yarns that go to make up the pile of a carpet O0CZEZ_VZ_ZZZTZZZ7ZEZZZZZZZZZZZZZZZZZ_

Page 33

October, 1919 Te le WE” LE cccccccccccccc5cuc33ccceccc4uccccccea id jadi billie LL LLe LL a dbgausmcisdiddididdéddddsda OLMEDO OLIN! : as you play an automatic paper (jazz or Beethoven by are called jacquards, after J. or) are slipped in.. The per- the weaving of the pattern SOT SSO DR Photographs © Underwoed & Underwood SOQ WW Right: The jacquards are per- forated in a machine that ‘is operated like a typewriter. The operator follows a painted design. The number of cards equals the number of weft threads in a pattern WWW WB p}P}p "—ww VAL UMMUUL ALAM LY ALLL EE OMMOOMALALOEALALUL LAL LOLAALLMLLAALUALS ALLL POL ALUL LAA AMR LOL YAL CLUE LLLOOULUL LOO LUMAR LULL ALLOLUMLLLLLALLOLUEOOUUMCLULLH MLL (IAL ME ALMA UU OUU ORDA AU DAL OUUMMUMLA LAMM Mate OPI tet SOQVKAAAAMNANWW Z g i Z y g g | y ) g Z g g g This is a rear view of a carpet loom; it shows the colored yarns on their way to the pattern-controlling jacquards; women are largely employed in this work This strange contrivance is simply a huge sewing-machine overcasting breadths of woolen carpet in order to make one large rug | aba gcse eeddddddcdacaaaédda LE eee ecddccccceddddaa ET cc ccd eeddddedssdecddddddddda SWAG wwwowqw_qwyeaggygnywgg AH SWAWOWWELLwwqowwom—ogM wg gaa TT Right: Cotton warp entering a carpet loom. Cotton is the real foundation of every good carpet AIEAAAOWW MQ Left: Imperfections in the machine- made carpet are “doctored”’ by ex- pert hand weavers Saag | i

Page 34

A Diversion for Theater-Goers eee OMORROW will tell!’ said the hero grandly; and the mirror fell on the second act.” Strange reading; yet words like these may appear in dramatic columns before long, for the idea of mirror drop- curtains has been revived. Sir James Barrie brought it to life again, and Mr. Albert de Courville is planning to build one for his ‘‘Little Theater’? in London. ; It will be raised and lowered by electric power, and will ty have air cushions to prevent jarring when the curtain = touches the stage, thus saving the curtain-raiser from a possible seven years of bad luck. Cutting HE airplane of today does not differ in principle from the first successful ma- chine of the Wright Brothers. But it is fully four times as fast. This increased speed is ob- tained not merely by the use of more powerful engines, but by so shaping the sur- faces that air resistance is re- duced to a minimum. When you increase the speed of any moving object from twenty to forty miles an hour, you do not simply double the air resistance—you quadruple it. Air resistance increases as the square of the speed. Every- thing depends on correct designing—on reducing resist- ance. So important has the con- sideration of air resistance become in building machines for fast flying that the resist- ing effect of every projection is studied. Turnbuckles, wires, even the helmets that the avi- ators wear, all are given the least resisting shape. Now, in order to discover what is the most efficient sur- face, the wind-tunnel is used. A litle model of the surface (a whole machine, or a wing, Down the ©keystone Photo News It looks like a gigantic talking-machine horn, but it is the intake of Glenn H. Curtiss’ seven- foot wind-tunnel, used for testing airplane models 54 The Glad-Handed Door HE storekeeper who has large red ‘“‘weleome” signs pasted all over his windows will be interested in g new invention by Robinson H. Harsh, of Chicago, for reassuring the timid public. It is an outstretched tin’ hand to be used instead of the stupid round door-knob, . It is attached to the door-latch, so that when a customer shakes it the latch will be raised and the door will open, The hand is conventionally clad in a cuff and coat sleeve — it even has finger-nails. When you grab it you have the pleasant sensation of shaking hands. The inventor wisely suggests that the hand be used only on the outside of the door. You may not feel like’ shaking hands on your way out. Popular Science Monthly” When a door gives you the “‘glad haud’’ you may be sure that you are welcome in the store behind it . Resistance of Airplanes or a fuselage) is held in a stream of air. The little model’s resistance is meas- ured by the pull that it exerts. Thus is discovered the shape that offers the least resistance. Obviously, it does not matter whether the model is moved in still air at the right speed, or whether the model is fixed and the air moves: the result is the same. ; When the air is_ being sucked through at a speed of one hundred miles an hour, the pressure on the walls of the experimental house in which the tunnel is contained is about thirty-six pounds per square foot. It is impossible to open the door leading into the house, even though you press against it as hard as you can with your shoulder. The largest wind-tunnel of its kind is that which Mr. _ Glenn H. Curtiss has built at Garden . City, Long Island. It is seven feet in diameter. The air is sucked through the tunnel by a powerful three- bladed propeller, driven by a four hundred horsepower mo- tor. The accompanying pic- ture shows the collector end of the tunnel.

Page 35

in a little — meas- certs. shape ance. atter loved peed, fixed esult being ed of hour, lls of e in ained S per ssible ‘into you 3 you el of Mr. ilt at land. eter. n the hree- by a -mo- pic- end October, 1919 Who Called? The Ticker Tells “fF POHEY don’t answer,” singsongs Central. You hang up your receiver disgustedly as that same nickel rattles back for the fifth time. If only you could leave word that you have called! . Ah, but Arthur Engelberg, of Oakland, California, has recently patented a device for doing just that. . It is a telegraphic arrangement, much like a news ticker, and is attached to the base of the telephone. When “your party does not answer,” you leave word with Central to have him call you. Central tells the telegraph operator in the office to notify Broad 900 that South 450 called. The telegraph operator is then con- nected with the absent Broad 900, and she sends a dot- and-dash “‘call South 450’’ over the wire. dashes register on the ticker tape at Broad 900, and when the absent one re- a turns he need only trans- late them into words. “Call South 450,” said the ticker tape when this man returned; he is the inventor of the combined tele- phone and telegraph crrangement for registering number. that have peceiyiné MAGNET called you while you were not there One Way to Make the “Sanitary” Fountain Sanitary NE . large railroad, which in- stalled more than a_ hundred “sanitary” water fountains in as many of its stations, found upon testing them that they were by no means safe. Germs of pneumonia, diphtheria, and scarlet fever were plentiful on various parts of the fountain, and even typhoid and other dangerous germs were not always absent. Where did the germs come from? The mouth of the drinker as it comes . in contact with the metal or enameled parts of the fountain. When the United States entered the war, and it became necessary to pro- vide sanitary drinking fountains for the army cantonments and camps in this country and in Europe, a type of fountain developed by a manufactur- ing concern in Ohio was selected. _In this fountain the water issues in two streams from the side of the fix- ture. Thetwo streams are placed at a slight angle to each other, and the user’s mouth is placed at the point where the streams-meet. An enamel- _ ed guard prevents the mouth of the drinker from touching the fixture. The dots and a When he pulls the cord, the weight will fall and hit the explo- siveonthe anvil. The pendulum always hits the explosive at the placed the explosive blow. DOT AND DASH sameangle. This is how the Bureau of Mines tests its explosives Will It Explode? . E pulled the rope, down came the weight, and bang! the powder exploded. It looked as if he were cele- brating the Fourth of July with a new kind of powder cap and stick, but in reality he was very seriously testing the sensitiveness of a commercial explosive to friction. He had on a steel anvil, and by releasing the pendulum weight had subjected the explosive to a glancing The forty-four-pound steel weight is faced with hardwood fiber. It swings down from a height of fifty-four inches. This equipment is used by the Bureau of Mines for testing a great variety of permissible, high, and military explosives. It is located at an experiment station near Pittsburgh. This pendulum friction device is a vast improvement over the broomstick method of testing explosives which was formerly used. no uniformity in sp It can be used either for drinking from directly or for drawing a glass of water 55 The explosive was subjected to the glancing blow of a hand-operated broomstick. There was eed or in the angle at which the ex- plosive was struck. A pendulum, when released from a fixed height, will always hit the explosive at the same angle and at the same gravity-con- trolled speed. Keep Out These Aliens EW YORK is very particular about whom she lets into her port; each incoming ship must stop at quarantine and pass a rigid health test before the people on board are allowed toland. This is to prevent the bring- ing of foreign disease and possible plagues into the country. Yet, strange to relate, we allow these same ships to dump earth ballast wherever they choose in the East River, the Hudson, and in all parts of New York bay. Thus: we run the great risk of having undesirable plant growth and accompanying plant pests. The United States Department of Agriculture warns us that, unless this habit stops, soil-infecting diseases, in- jurious nematodes, and hibernating insects may spread over the whole , country. The Department of Agri- culture is investigating the matter.

Page 36

Simple life on a farm did not appeal to the tractor shown at the right, soit moved to a big city ~ Qut of the ‘water cn to the sand: ~Tractcrs haul the ¢reat seaplanes « to theif hengars when * the day’s work is done; ~*~ one tracter is capable/of handling each plane (= Tractors and Tanks Today Get Peace-Time Jobs Popular Science Monthly : Now it hauls huge pon- toons for bridge-build- ing; this picture was taken in Washington They.are using tanks for tug-boats on the Marne canal in France; one small Renault tank is able to haul four heavy barges at the rate of two miles an hour Testing Airplane Engines Behind Chain Curtains HE airplane engine is a wonderful piece of mechanism. It must be compact, because space in the fuselage is extremely limited. It must be light in proportion to the horsepower de- veloped. Try to imagine an engine capable of developing one hundred and thirty-two horsepower which weighs. only one hundred and ninety-four pounds. Not all engines are equally light in com- parison to their horsepower, but only in a few of the largest and heaviest types does the relative weight exceed two or three pounds per horsepower. That means that the material must be able to withstand enormous strain while the engine is -working under extremely high pressure— as high as one hundred and twenty-nine pounds to the square inch and making from twelve hundred to twenty-one hundred revo- lutions a minute. Think of the terrific strain upon the engine and its propeller cleaving the thin air in high altitudes at maximum speed, and you will under- stand that an engine upon which such extreme demands are made must be thoroughly tested before it is placed ‘in commission. Every airplane engine must be tested under running conditions; therefore, in all factories where large numbers of such engines are built, special provisions must be made for protecting the life and limb of me- chanics engaged in making the tests. There may be the slightest defect in the material, a defect so © Wolseley Motor Company When the engine is to be tested, the heavy chain curtains are closed over the front to protect the workman from injury in case of accident 56 minute that it escapes the scrutiny of the eagle-eyed inspectors, a weak spot ora lack of proper adjustment which manifests itself. with startling vehemence during the test. A pipe or a cylinder may burst; the crank-shaft may break; the propeller may fly to pieces. In the airplane factory of an English company every engine to be tested is temporarily mounted on a framework in one of the stalls, the ‘sides and fronts - of which are made of heavy chain curtains, . Protected by -these curtains, the workmen and_ engineers can observe the working of the engine without risk of injury should the propeller fly to pieces.

Page 37

re one ur ate our > -Oetober, 1919 Carry a Saw in Your Pocket T will curl up and nestle harmlessly in your pocket; ] but when you take it out and open it, you will find it a dangerous thing to play with, for its teeth are so sharp that they will cut through wire, or even trees, very easily. Such is the folding saw shown below. The segments are studded with small pieces of very high-grade steel that are well sharpened. When the saw is stretched out its full length it measures a yard. There is a ring at either end for handling it. The saw bears the old but still remembered ‘‘Made in Germany” stamp. It was brought here by an American soldier who had already collected an Iron Cross and a “Gott mit Uns’ belt-buckle. He found the saw in No Man’s Land, and says that the German who owned it had used it for cutting down barbed-wire entangle- ments. We present the idea here, thinking that the saw may have some peace-time use. When curled up, this saw is quite — harmless and will fit into your pocket; but when it is stretched out to its full yard length, the sharp teeth are exposed Helping the Hard-Working Piano-Mover | _ This tractor binder has dealt poor old Dobbin another knock- out blow. A few more and Dobbin will have to take the count Farming Under the Sign of the Iron Horse ARM tractors have long been employed for haul- ing plows, cultivators, planters, mowers, and reapers; and now a Western manufacturing concern has placed in the market a horseless binder, propelled by a gasoline-engine tractor which also supplies the power for operating the binder machinery. The binder is hitched to the tail end of the tractor, and receives its power from it through the medium cf a tumbling-rod. It is comparatively light of weight, and it can be operated successfully by one person. Tractor binders of the type shown above are oi particular value on farms of large acreage; but even on smaller farms they may be used at a saving of expense if a number of farms club together UDGING by the crowds that gather at piano-hoistings, the general public enjoys them—but not so the hoisters. Their job is a difficult and clumsy one; for a piano is about the unwieldiest thing made. The so-called “‘self-lifting piano-sill’’ is intended to make the piano-mover con- tent with his lot. It is a platform with two handles and with rollers at both ends, and is attached to the lower end of the side of the piano by means of a hook- By pressing.down on the handles he raises the piano from the floor; in this position it is much easier to handle shaped lever that fits underneath the piano. By pressing down on the handles you can raise the piano off the floor. These platforms are strapped to the ends of the piano. Aiter the piano has been raised from the floor, it is easily rolled about on the | casters at the sides, even when it is standing on end. The handles that do the lifting may be folded in, out of the way, without disturbing the position of the piano. Cleaning London’s Air NSUSPECTING Londoners would probably be very uncomfortable if they knew what the Atmosphere Pollution Research Department recently discovered about their city: that each cubic inch of air in the vicinity of London con- tains six million partieles of dust. Pure mountain air contains only thirty thous- and such particles to the inch. Germs, too, are so plentiful that it is Almost in: make it possible for the men to roll the piano on its side after it lands estimated a man putting in a ten-hour ’ day in the City inhales some thirty-seven million microbes of all kinds. It has been put up to the Atmosphere Pollution Research Department to find a remedy. the casters

Page 38

j _— eatin ci ri vis “ ——a Popular Science Monthly How Will You Have Your: Eggs? Boil ’em, not in oil, but in a hot spring. The lady below is dipping an egg in one of Yellowstone’s springs ot P Sy Roast.’em:in’hot ashes! Though this méthod smacks of the Spanish Inquisi- _tion, roasted eggs. make good eating Jig A cup of water, one fresh egg, and one lighted electric bulb, mixed together, is the latest recipe for soft-boiling Take out your grudge on the land- lord and save gas by using up his hot water for boiling your eggs This boarding-house trick is a great muscle - developer; when she lowers her arm she will have before her a panful of fried eggs Only Insulated Thieves Can Steal This Grip MAN, who has entered the parlor-car from the other end, walks down the aisle in a businesslike manner, looking from one side to the other, as if he were trying to remember the location of his chair. He must be the owner of the prosperous- looking satchel in the vacant seat near the door, for he stops -and takes hold of its handle. As he lifts the satchel, a smothered “Ouch!”’ escapes his lips.- He drops the grip, and hurriedly leaves the car. * He was a thief. Why did he not carry out his intention? He had received a-painful electric shock. An electric battery and “shock coil,”’ stowed away in a little pocket inside the satchel, is connected with two metal strips on the inner side of the handle. body else’s satchel, It was his intention casually to walk off with some- but he received a shock 58 The two strips are separated by a non-conducting strip. Whenthe hand is placed under the handle, the fingers, resting against the metal strips, act as conductors and form a bridge for the primary circuit of the electric current. A secondary circuit, causing the shock, is inter- mittently closed or broken by the up-and-down swinging motion of a balanced vibration lever when the bag is carried away.

Page 39

vA October, 1919 Why Does N This two-headed turtle lives in the Chicago Academy of Sciences additional leg of a three-legged chicken, the extra head of a two-headed snake, the lack of color of a white crow—these are called ‘unit characteristics.”’ A pair of double- headed snakes _ will have all double- headed offspring. It so happens, how- ever, that these freaks of nature are rather short-lived. When they do mate, it hardly ever happens that they mate with one of their own kind. But here, again, Mendel’s law applies. Fifty per cent of the offspring will be hybrids of a very unstable kind, “throwing back” to one or the other of the parents in their offspring; twenty-five per cent will be pure-blooded like one parent, and twenty-five per cent pure-blooded like the other parent. This explains why, in a family, some of the children may be tall and some short. is unstable. ature Do It? OUBLE-HEADED alves, Siamese twins, three-legged chickens—why is it that nature plays such pranks? knows exactly. species, whether animal or plant, The four-leaved clo- ver and the white crow—just as remarkable, in their way, as the monstrosities of the circus side- show—prove it. Darwin preached that new species are created partly by natural selection and partly by the age-long accumulation of acquired characteristics. But latter-day scientists have decided that new species are also created not only in this long, slow way, after millions of years, but suddenly. . The chief exponent of this view is de Vries, who promulgated what is now called the ‘mutation theory,’’ and which is accepted by many naturalists of our day. A monk named Mendel, after experimenting with some sweet peas, developed a law of heredity which teaches us that these suddenly developed species or varieties are really per- manent if they can be made to reproduce. No one Every living Such monstrosities as this three-legged chicken can be artificially produced. Biologists have whirled eggs in centrifugal ma- chines before hatching with very curious results This two-headed snake is also in the Chicago Academy of Sciences. The whole science of “‘teratology”’ has been built up in an effort to explain those couplings in the animal world that give rise to double- headed and double-bodied forms The beautiful antennae of insects are now thought to possess a sense uncomprehended by human ‘beings Have Insects’ Antennae Some Unknown Sense? T is the general consensus of opinion among entomologists that the an- tennae of insects smell as well as hear. Those of us who have studied these wonderful organisms are inclined to think that they contain some sense, or at any rate a sense modification, that human beings cannot comprehend, because they possess no faculty that exactly corresponds to it. There is a modification of the sense of smell that does not seem to be only that sense as we know it, because insects are at- tracted before it would seem possible for the odoriferous particles °to be carried to the distant insect. Recently a naturalist made an ob- servation. He was in the woods one day, when his nose began to bleed. Within a minute after the blood had fallen on the leaves, the flesh-flies appeared. Yet it was a perfectly still day. In such cases it does not seem possible that the flies could have been influenced by smell as we ordinarily understand it. An astonishing fact is that the antennae of various in- sects show so many different forms. These, however, have long been the delight of the microscopist. How a Snake Wriggles into the World HE National Zoo in London announces the arrival of three new- born ring-necked snakes— all doing well. Of course, there isn’t anything very unusual about the birth of a snake, but these three little ories were caught by the camera man in the act of coming into the world. The pho- tograph is shown herewith. As will be seen, the old- est of the triplets has en- tirely cast off its shell and is raising its head in order eee ——— to take a good look at its surroundings. The other two have just started to emerge from their shell; but no odds have been offered as_ to which one will get out, first. These snakes are called ring-necked because of a pale yellow marking in the form of a ring that appears around their necks. ‘They belong to the harmless Colubrine family, which is Caught in the very act of being born, these ring-necked _— snakes are racing to see which one will get out first Britain. 59 found mostly in Great

Page 40

— wpe nome wooed y

Popular Science Monthly Give a Thought to These new ideas and accessories will se MON SPRING EXPANDER

PISTON RING GROOVE i When the piston rings be- come loose the compres- The contractor moving from job to job hauls his twenty-two-ton sion in the cylinders is lost. steam shovel over the road by a truck at a speed of eight miles This spring expander is in- an hour; this was formerly the work of five teams of horses serted in the groove in back of the ring to keep it tight

" aN . “COUPLER - ~ INTAKE MANIFOLD cS SUPERHEATED AT TWO POINTS fa ORAWBAR | . : g oS.

" cix uf n|> i. 4 pairs w/e i: The phantom view x Two sets of coil springs take up ee — “8 the starting and stopping strains of heavier grades of fuel so that they vaporize readily

In this new type of wheel all shocks are taken up by the hub. The wheel is puncture - proof and protected by steel plates

ntl UES. or, * On the rear deck of a new roadster is a removable cover that permits the owner to carry a steam- er-trunk, a sample-case, or any . other bulky article

VUMUMULUEOMTMOMOoc00 000 t0tME AO obs ( Ee adadddddédddda TE emda MAMMA

Here is a good idea for the trac- tor dealer who wishes to: adver- tise the tractor-he is selling. This particular tractor moved a circus when its horses were mired

It is said that this thirty-ton section of a Pacific Coast giant is the largest single log . ever hauled by a motor-truck and trailer

Page 41

bt

October, 1919 Motor Maintenance help you keep down overhead

The center-thread grease-cup makes filling more easy, and assures a certain and quick job of screwing down its cover without the annoying’ fault . of crossed threads

“SET=SCREW TO ADJUST __ OILRESERVOIRY ‘TO WIDTH OF * pee es SPRING CATCH LUG FOR ADJUSTING c mgm, TO DEPTH OF a, SPRING >< SPRING = ns s co am casei . PSS ~ ae 7 < Senate E Soa Peas SON - i? : "FELT PACKING \ ~ FEEDS OIL t TO SPRING’ Here is a spring oiler that is very simple in construction, and which may be fitted upon all sizes of motor-vehicle springs. The oil is poured into a reservoir in its top

SAN i ¥ AANA TT

This truck spreads gravel thinly upon the road, so that it in no way interferes with traffic and does not require men for further es a ; ; Spreading. It travels at ten miles an hour can be inexpensively made

i The tractor is gradually replacing the truck for various heavy hauls. Here it is shown doing the ; i work of sixteen horses ef, — os | hFSe e y

In a factory at Melbourne, Australia, an explosion sent an automobile tire hurtling through a*hardwood floor. The tire was found to be uninjured SPEED a ‘ ty. : Pistol grip and trig- PER HOUR Will your car do this 2 ger switch allow the oe a valve-grinder to be operated after the manner of an auto- matic gun. Bits are provided to make it adaptable to various valves 0 miles SG om

A chart showing in what distances cars ought to be able to stop if their brakes are in good condition

A wood block stand for hold- ing pistons that need drilling

Page 42

~ Save Money by Baling Your Clothes Apply this lesson learned in the war Sees By Michael Connors ‘an exporter of clothing, it will mean dollars and cents to you to learn-how the Quartermaster- General’s Department shipped uniforms and shoes to France in a. way that saved the Govern- ment eighty-five million dollars in a little more than a year. Few of us realize how desper- ate was our need for ships at a _time when German submarines were sinking six hundred thou- sand tons a month. ‘Give us ships, ships, and more ships,” was the demand of those who had to equip and feed our Army in France. In the autumn and winter of 1917-1918 it became apparent that if the war was to last very much longer there would not be shipping space enough to carry the equipment and supplies re- quired by the forces that we in- “tended to send overseas. New methods of shipping equipment had to be invented, and the man who invented them was Major David T. Abercrombie, of New York. |: you are a manufacturer or Compressing Twenty Cubic Feet into Four Clothing is usually shipped in wooden packing-cases. But during the war wood became scarce. Major Abercrombie estimated that 72,762,- 300 feet of board lumber, 2,425 tons of nails, and 404 tons of strapping would be needed. The lumber re- quired would have denuded 7,552 acres of timber-land—lumber that could not be grown again for years. thirty *“‘We won’t use packing-cases,”’ de- cided Major Abercrombie. “But what will you do?’ they asked him. “Bale everything,” was the answer. And that is how it came about that the Government saved eighty-five million dollars. Major Abercrombie experimented, and found that clothing could be squeezed so that, roughly, twenty cubic feet of material could be made to occupy four cubic feet of space. Con- sider that ship tonnage is charged for on a cubic foot basis, and that during the war the rate was eight dollars per cubic foot, and you can see at once that by compressing twenty cubic feet to four cubic feet a saving of ninety-six dollars was at once effected. Then We sent uniforms to France, not in packing- cases, but in bales. The outer burlap was used for the making of two million sand-bags consider that during the war 1,371,000 bales were shipped, that the net saving on each bale ranged from fifty to sixty dollars, and you can see that the Government saved eighty-five million dollars. Major Abercrombie’s project also released 8,180,000 cubic feet of shipping space. Major Abercrombie dis- covered that proper baling depends on the proper folding ofa uniform. Baling should crease a uniform along the right lines. Folding the Garments Scientifically To carry out Major Aber- crombie’s process, the gar- ment is first carefully folded to aform. A given number of folded garments are then packed in a brick container, corded together so that the bricks cannot fall apart. . The folded uniforms in their brick | container are then placed in a ma- chine. 62 Popular Science M. onthly Introducing Major David T. Aber- crombie, Q. M. C:, the man whose : baling process saved the Govern- ment eighty-five million dollars in a little over a year’stime. Instead of shipping uniforms in packing-cases, Major Abercrombie baled them by a process that he invented himself First of all, hand pressure igs © applied to form a fairly compact bale. But that bale is not com- pact enough for Major Aber- crombie. It is subjected: to the additional squeezing effect of a power baler until it assumes the highly compressed form that he ‘has in. mind. Waterproof paper is used asa lining for each bale. Major Aber- crombie had to invent a paper of his own—a creped waterproof paper that would stretch thirty per cent in one direction and ten per cent in the other. Thanks to that paper the bale becomes absolutely waterproof. In order to save shipping space when the submarine was doing its worst, the Quartermaster-General shipped army shoes abroad in bales, the space they occupied being reduced by about thirty-four per cent. Why not use this system in time of peace?

Page 43

of October, 1919 Electromagnetic Scissors ~ for Cutting Cloth AILORS, dressmakers, and _. others whose business com- pels them to use shears or scissors frequently, may save themselves a great deal of unnecessary waste in strength and energy by employ- ing mechanical scissors operated by electricity, air-pressure, or some other force. The current, acting upon a sole- noid, causes the plunger within the coil to move toward the closed end of the tube, away from the cutting end and against the pres- sure of a coiled spring, which asserts itself whenever the electro- magnetic power of the solenoid ceases to act. The. alternating forward and backward motion of the plunger causes the scissors to open and close. The solenoid tube, with the cutter attached, has a handle by which it is guided by the operator. A flexible tongue, extending be- yond the points of the scissors, lifts the material to insure a smooth cut. If only direct cur- rent is available, the apparatus must have an automatic inter- rupter. EE) is PLUNGER “AN This recent French GUIDE SPRING” invention can be used wherever an alternating electric current of low frequency is available The Cargo HIP, cargo; cargo, ship: remove the ship and let the cargo serve as both. So said the owners of five million feet of timber which they wished to send from British Columbia to England. The timber was sawn so that it measured twelve inches square in cross- ts features of New York’s upper harbor. lost most of its artistic charm, it is infinitely more useful What the War Did to Governor’s Island EARLY everybody who lives in the vicinity of New York knows Governor’s Island; yet it will probably not be recog- nizable in the view shown above, which was photographed from an airplane flying over the harbor at a height of eight thousand feet. Governor’s Island did not always look like this. Not morethan Now, though it has twenty-five years ago the island was only one third of its present Is the Ship section. The floor of the ship consists of six alternate layers. The sides are flat and the bow and stern wedge- shaped. The ship is held together by steel screw-bolts. When she reaches England the bolts will be taken out and the lumber used. Besides sails, the ship is equipped with heavy-oil engines. Near the engine-room are the chart-room, the captain’s quarters, and crew space; under the forecastle deck are the stores and chain locker 63 size. It included only the irregularly . shaped part at the north end of the present island, easily distinguished in the picture from the new filled-in part with its. painfully regular outline. During the war Governor’s Island became an important base for the dis- tribution of military stores. On the filled-in part, which comprises fully two thirds of the island, fifty-four ware- houses were erected in two parallel rows. In the aisle between the two rows a railroad line was built, with a Y to the loading and unloading pier near the southern end of the island. Comparatively few. changes were made in the original, old part of the island. On this part are the ancient citadel used as a military prison, the star-shaped fort, the barracks. for the soldiers of the garrison, the comfortable officers’ quarters, the various office buildings of the De- partment of the East, and the parade grounds. The landing-places for the ferry lines that connect Governor’s Island with Manhattan and Brooklyn are located in the northern part of the island, facing the mouth of the East River. Cables containing telegraph and telephone wires put the im- portant military offices on the island in direct touch with the outside world.

Page 44

‘Can You Make a Crate that Won't Break? | Some results of the Forest Products Laboratory’s experiments in the testing of boxes, barrels, and crates Se ilord:E. Darling years, rather been forced to the ~~ conclusion that there is a science and art in the building of shipping con- tainers. Before: the war this conclu- sion was thrust upon them by the mishaps that befell them in attempt- ing to reach South American and other foreign trade. But during the war the idea crystall- ized. It culminated in special activity on the part of the Forest Products Laboratory at Madison,’ Wisconsin— a branch establishment of the United States Department of Agriculture. Here a school was brought into being for the training of men having to do with the packing and crating of quantities of material sent overseas. « The tests made here, primarily instituted to promote war efficiency, have provided a fund of information that will be invaluable to manufac- turers and shippers in peace time. The shipping departments of the larger manufacturers have already made tests and experiments of their own. In fact, every package sent out is an experiment. But the sub- ject is still dark and uncertain in a great many of its aspects. So we pass along the results of the Forest Products Laboratory’s experience because of their special value in contributing to the general fund of ee sen, have, .within recent -knowledge on the subject. What methods are followed in this packing-box testing laboratory? We may preface an explanation by quoting D. L. Quinn, in charge of the Madison Laboratory’s work: “A properly designed packing-box is one which has enough strength in each part for the purpose for which it is in- tended. More than this, it should have no more strength in any part than is necessary to balance the average strength in every other part. The data necessary for designing such a box cannot be obtained from observation of boxes in actual commercial service, be- cause the observer sees the box only after it has completely failed. He does not see the beginning of the failures; and he does not see, and consequently cannot measure, the hazard which completes them. ; ‘A failure frequently bears evidence in itself of the cause of the damage. There is, however, no way of determin- ing from a study of the failure the amount of force exerted by the damag- ing cause. In cases where several causes have been active, it is im- possible to identify each of them.” He concludes, therefore, that the immediate task of a testing laboratory is to go at one thing at atime. That is, the tests applied to containers block-and-tackle machine finds out whether a box will stand falls will be shown up singly, and under such conditions that the stress applied, and also the re- sults, may be carefully checked up and kept track of. By thus measuring defects individually and “‘pooling”’ the results, so to speak, the tester will be able to gain a comprehensive knowl- edge of the all-around strength of the box or crate, and its probable capabilities when in actual service. Initiating Tests The ‘‘compression along an edge’’ is one of the tests applied. This consists in standing a box upon one edge and applying a steady and constantly increasing pressure to the diagonally opposite edge. The longer the box holds out against such a squeeze, the better box it is. Another box of in. 64 should be of such a nature that defects | Popular Science Monthly What happens to a box after the freight-handlers have given it their attention. The Forest -Products Laboratory hopes to prevent this the same kind will be stood up on one corner, and then pressure applied to the opposite uppermost corner. The longer the box holds out against thig test, the better box it is. The il- lustration at the bottom of this page shows details of the process. Another test applied to boxes‘in a laboratory isto dropthem. Simple, isn’t it? Even a youngster applies that principle. If Amy Brown hasa doll with a china head, ‘and she de- liberately drops the doll on a cement sidewalk, and the head doesn’t break—why, naturally, the doll isa better one than Dorothy Smith’s, which does break under such condi- tions. Simple as A BC. So in the laboratory they: drop boxes. They haul them up off a solid floor with a block and tackle, and then let them come violently down again. They let them come down on an edge, then on a corner, on an end, on a side— every way. If the box Squeezing a bo« coraerwise to find out how much persecution it will endure before giving Good boxes stand a great deal of this

Page 45

| One d to The this a il- this ina ple, lies asa lent sn’t isa ¥, stands up under all that, it is a good pox and can be depended upon to stand up under actual service; because such man-handling as this is what the pox actually gets from the freight rustlers and dock employees. The testers reason that it is better to find out in a laboratory whether a given kind of box is no good for its purpose than to find out on the road, and per- haps lose valuable goods in the process. That this is sound reasoning, is evident. The Revolving Drum A- particularly choice number in the repertoire of the testing men is to run a box through the revolving drum apparatus. This looks a good deal like a concrete- mixer, only its drum is larger. A box is put inside the drum, then the drum proceeds to go round and round in regular concrete- mixer fashion. Meanwhile the box is bumping around among all kinds of pillars and posts inside. When it comes through this test—if it does come through—it is initiated indeed. The drum revolves so slowly that, as the box drops from one projection to the next, the beginning of breaks and cracks can be noted. The weak points in the construc- tion of the box will, of course, readily make them- selves apparent, and in the next box made along this line, the construction can be altered in such a way as to avoid defects of the kind that the test brought out. By continually building and testing in this way, boxes are ultimately developed that are equally Effect of Wet Lumber and Storage The following chart, based on the Forest Products Laboratory’s inves- tigations, shows how the strength of a box.is altered by moisture and by neglect in general. Keep your boxes dry, but not bone-dry. Strength Relation Per cent Nailed and tested at once at 15 per cent moisture..... 100 Nailed and tested at once at 30 per cent moisture..... 90 Nailed at 15 per cent, tested at 5 per cent moisture, 4 months’ storage......... 75 Nailed and tested at once at 5 per cent moisture...... 50 Nailed at 30 per cent mois- ture, tested at 5 per cent moisture, one year in Oo Sees ery aera 15 Nailed at 5 per cent moisture, tested at 35 per cent mois- ture, stored 2 weeks in ex- haust steam............ 10 strong in all features. Like the ‘‘one- hoss shay,’’ they will go to pieces all at once, if they go to pieces at all. Their failure will not be because of single defects, such as nails pulled through soft wood, or because ends of boards split or broke off, or because the wrong lumber was used for that particular box Round and round goes the box in the ‘‘concrete-mixer ma- chine,” receiving bump after bump. hidden defect it is sure to be revealed during the process in the first place. The box constructor will know what he is doing. The laboratory has found that the length of a nail, rather than its gage, seems to be the principal factor in its holding power. Since nails split wood, it has been found that it is desirable that as small gage nail be used as can be driven by a nailing-machine. Mr. Quinn finds that standard cement- coated box nails seem to be most desir- able from the standpoint of both efficiency and economy. ‘“‘Nails,’’ says Mr. Quinn, “should be driven flush with the wood. They These blocks of wood have been through a stretching- machine to see how much tensile strength they have. The cracks show where the wood broke 65 If the box has any should never be over-driven. Over- driving causes the heads to break the fiber of the wood under them, often to such an extent that no. holding power is left in the wood. The first strain on the box then causes the wood to pull away from the nails. The evil effect of over-driving nails naturally increases as the material in the boards is mide thinner. But in any box over-driving is bad practice, and should be guarded against. “‘The size of the nail to be used depends upon the species and the thickness of the lumber in which the points of the nails are held. With the woods white elm, red gum, sycamore, pump- kin ash, black ash, black gum, tupelo, and soft or silver maple, as well as hard maple, beech, oak, hack- berry, birch, rock elm, and white ash, the penny of the nail should be the same as the thickness of the lumber expressed in eighths of an inch. The following woods take the next penny larger: white pine, Norway pine, aspen, spruce, South- ern and Western yellow pine, cottonwood, yellow poplar, balsam fir, chest- nut, sugar pine, basswood, cypress, willow, noble fir, magnolia, buckeye, white fir, cedar, redwood, butter- nut, cucumber, alpine fir, lodgepole. pine, hemlock, Virginia and Carolina pine, Douglas fir, and larch. ‘“‘Sixpenny nails and smaller should be spaced not more than two inches apart when driven in the side grain of the end, and not more than one and three fourths inches apart when driven intheend grain. The spacing of nails in end construction should be in- creased from the above, one fourth inch for each penny over six.” More Facts About Nails One hardly realizes the force it takes to pull a nail out of a wooden board. In experimenting with the holding power of cement-coated, plain, and barbed. sevenpenny nails, driven one inch into dry wood, Mr. Quinn obtained the following facts: Using a cement-coated nail, it takes about a 225-pound pull to get a nail out of one inch of longleaf yellow pine, 133 pounds out of bass- wood, and 430 pounds out of beech. Plain nails took 140 pounds with longleaf pine, 82 pounds with basswood, and 400 pounds with beech. Barbed nails required only 110 pounds with longleaf pine, 70 pounds with basswood, and 335 pounds with beech.

Page 46

el, gh aaniid + ‘Hairpins can be woun The hairpin is pushed through the cork, and the projecting ends bent into the cork again, forming an emergen- cy handle to remove the cork from the bottle with perfect ease.—C. F. Gimm d on a piece of drill-rod to substitute for stripped threads. Needless to say, they work to perfection.— James McIntyre Popular Science Monthly Who Won Our — WV HEN you glance at the illustrations below we are sure you will proved, beyond a doubt, that the humble hairpin, in an emer- letters from all parts of the world, and many and various were the of the ideas, but for their practicability. The hairpin now assumes a new dignity; for it not only has afield. Fish-hook, gun-cleaner, finger-splint, scrubbing-brush, only a few of the best. All hail to the humble tress-binder of We wish to thank the contributors, and offer the non-winners Prize Contest announced on page 124 of this issue: ‘What Can Be If you run out of test-tube HOLE TAPPED ON holders, curve one end of a HEAD OF > hairpin and secure the other MACHINE toacork.—William Wylam SCREW HEAVY NUT FILLISTER. HEAD MACHINE SCREW END VIEW OF HAIR-PINS PLACED IN SLOT The first prize winner is Francis R. Pray. He says; “The common wire hairpin makes an admirable resistance unit. As the hairpins are all machined to the same length, each one has a resistance which varies with its particular size. When mounted in between the con- tact points of a rotary switch, a rheostat, variable in uniform steps, Holes are drilled into a wooden block, the hairpins thrust through, and another block with a handle placed over them. This forms an unusually strong and handy scrubbing-brush.—F. Spangler results. Such a contrivance is reliable, and easy to assemble’”’ Here the hairpins are bent into clips and fastened to ends of wires that runtoalamp. They form an emergency connection.—Otto Kirby

Page 47

Oetober, 1919 Hairpin Contest Jur forth a few of the avalanche of the Popular Science Monthly This made nose-piece.—W. C. Scully &, es Twist up, some match-sticks in a hairpin, remove them, and substitute brush bristles taken from an old brush, then twist the whole together tightly, and you have an efficient cleaner for your gun.—Lawrence Halsey —= ou will never despise the hairpin again. PopruLar SciENCE Monraty has | emer~ gency, is without a peer. The Contest Editor was swamped with ere the uses suggested. The judges awarded the prizes, not for the novelty ly has saved human lives, but it has rendered first aid both at home and -brush, bottle-opener, rheostat, belt-splicer, stub-nose straightener—these are der of woman. ‘inners another chance in PopuLar Science Montuty’s Ninety-Dollar an Be Done With the Exhaust of a Gasoline Engine?””—Contest Epitor. —= Having the misfortune to break the nose-piece of my = glasses, I soldered a hairpin to their frame. i an excellent though unusual UT | > -W oF Clifford A. Butterworth won the second prize-with a hairpin repair for a broken automobile fan belt. Heavy wire hairpins were put in place of the old lacing, and bent es shown, so that they could be hooked together PARTS MOUNTED ON BASE John A. Weaver won the third prize with a hairpin detector. It is known as the cat-whisker type, and, strange as it may seem, it will be found just as efficient as the most elaborate and : . expensive instrument made. Many Baby Katherine soon became quite B wireless operators have tried this content with this unusual treat- a= ment, and after eleven months of Recently a patient came to me with a broken index finger. Unfortunately I had no splints. Some large hairpins around the office suggested a novel splint which I put into effect with excellent results.—Dr. John N. Lawrence wearing the hairpin was cured of her I took the hairpin, wrapped a little ad- hesive plaster around the wide end, brought it to- gether, and made a sanitary splint. The finger fitted the hairpin snugly and it was in no way uncomfortable 67 ugly stub-nose.—Alfred C. Fox Here is a spark-plug tester made from hairpins and a small wood block. The ends are grounded on the block and engine block, and a spark jumps the gap made for the purpose. Thus your spark-plug is tested.—Anthony F. Schoch

Page 48

Popular Science M. onthly The Latest Fashions in Radiators na ratyea ie The ring type circular radia- - tor is peculiar to one or two makes of trucks. It is set in back of the engine instead of BLOWER in front, and the blower fan is inside the nest of tubes Different makes have different RADIATOR CASING BOTIOM WATER-TANK A novel feature of this radiator in- cludes a tube that is filled with kerosene and lighted to keep the water from freezing in winter Here is the truck with the circular radiator mounted upon it, a sketch of it being shown in the upper left- hand corner of this page. Removable shields shut out excess air in winter ‘ . é ao | WALL Ease of repairing is one ad- vantage of the continuous fin tubular type; another is its unusual rigidity and the core _ construction, which makes possible a quick and unimpeded ex- haustion of heated air DOUBLED TAP The two essential units in the continuous fin tubular type of core are vertical water-tubes and _hori- zontal cooling fins or plates. This allows a large volume of air to circulate throughout the system The honeycomb type is noth- ing more than a combination of hexagonal or other shaped openings, with the metal so thin that the heat is radiated quickly. The core is made up of a series of tubes which are expanded at each end, leaving narrow spaces between the tubes Then there is the plain tube type, with the tubes cylin- drical in shape. One of these is shown above. The tubes are placed vertically, and tied together in every direction by the horizontal plates, which are re-inforced with steel wire at the front and rear edges A seldom used type is this one composed of spiral tubes. A wire screen placed in front of the radiator protects it from accidental injury &g2

Page 49

October, 1919 for Trucks and Automobiles ‘types of cooling systems The flattened or deformed oval type of tube, in which the tubes are ar- ranged one be- hind the other The air-cooled engine works efficiently without the aid of water and other cooling apparatus, such as radiator, hose connec- tions, piping, pump, and water connec- tions. The air is drawn down and around through the engine by the flywheel fan In the type shown at the left, the finned tubes are arranged horizontally in- stead of vertically, as is usual in the average truck The seamless helical tube radia- tor is a result of long expert study in radiator design. It is fitted with spiral fins on each tube, as shown at the right Cc ag o/ In this type the zigzag tubes are set together to form a part of the radiator, the tubes being of the pressed metal shape. The ar- rows show the | course of the water | in its downward i flow. Note the large cooling areas | | | \ SOLDERED = = ‘ ° Set a: iI XX LA 4 aaa, 660 i. ad ah ath: nh at Here is a cut-away view of the honeycomb type... The water, poured into it, flows from the upper tank down through the thin compart- ments to the lower tank AAA A KK FS Va On On, 0.8, 8-8-0 n .*% an Va Vn ©. O. 8.0 - @-0-e K* SX XXX) oon FRONT NO SEAM WATER The modified honeycomb type is made up by taking one piece of metal and bending it back in the center. The two ends are then brought to a straight edge, lapped, and set to- gether under pressure, elim- inating one joint in the tube In the true round type of tube, set vertically, some of the designs are furnished with fins which are attached individually to each tube by means of shoulders that fit solidly against the tube

Page 50

aneemmumeo! 3 See NR NNO AN SOREN a ot ‘In which we attempt to set forth in What Can We Do About the High Cost of Living? = y f4 : “4 ¥ " > oe pictures why we are chasing dollars more madly than ever, why the dol- lar is fleeter than we are and why we have got to increase our speed N addressing Congress on the cost of living, President Wilson said: ““With-the increase in the prices of the necessaries of life come demands for increase in wages—demands which are justified if there be no other means of enabling men to live. Upon the increase in wages there follows close an increase in the price of the products whose producers have been accorded the increase. ... The laborers who do not get an increase in pay when they demand it are likely to strike, and the strike only makes matters worse. It checks production, it affects the railways, it prevents distribution and stops the markets, so that there is presently nothing to buy, and there is another excessive addition to the crisis resulting from the scarcity.” According to a statement recently issued by the National Industrial Conference Board of Boston, the cost of living for American wage-earners was 71 per cent higher in July, 1919, than at the beginning of the World War in July, 1914. This is an increase of 6 per cent since March, 1919, and of 12 per cent since July, 1918. Since the beginning of the war, food has increased in cost 89 per cent; shelter, 28 per cent; clothing, 100 per cent; fuel, heat, and light, 57 per cent. What is the remedy? Economists are agreed that there must be an increase in production and more-efficient distribution. We are all in a treadmill. There’s no use in agitating for higher wages. Just as soon as we step up one rung in the scale of wages, we increase the cost of living. It is not more dollars that we need, but greater efficiency, so that we may produce more with the same or less effort. It is not what the dollar will buy that counts, but what the day’s wage will purchase. No money on earth can buy goods that do not exist. High wages will not help if production falls short. Therefore, produce. Whatever you can do to increase efficiency tends to increase the amount that your wages can buy Popular Science Monthly ~ % a ‘sj Siga>, = oad aah } Here is the Modern Donkey. All he sees are those dollars ahead of him. He wants more dollars; but the harder he runs to catch up with them, the faster they recede from his grasp. If you put by a dollar in 1896, by the year 1909 it was worth in goods about two thirds of its original value. Today all that remains of it is rather less than one third. Those who have suffered most by the in- creased cost of living are office employees and members of the professions. They are ground between the nether millstone of capital and the upper millstone of labor. This situation has become so acute that pro- fessional men, physicians, chemists, etc., are throwing to the winds all tradition and prece- dent and are forming unions in order that they may bargain collectively for a large income PRICE OF QV ex ence #

Page 51

are nore 1 up The modern industrial world is a kind of machine. Raw material drops into the hopper of the ma- chine, and out of it come finished goods. You are the steam engine, and the operative mechanism of that machine. You must produce more. The friction must be eliminated in the machine, which means that more lubricating oil and axle- grease (efficiency) must be used to make the machine run faster and produce more in a given time. The man with the wheel- barrow on the inclined plane also pushes home the point. We need mechanical aids. Walking up an inclined plane, a man can raise a load that he could not possibly lift alone on the level As the picture below shows, we strike a balance between the purchasing power of money and the goods it buys. Somehow, the goods are constantly getting heavier, so that we must throw more and more money into the opposite side of the scale. To make our money purchase more than it is purchasing now we must produce still more goods It’s the same old dollar, so far as it appears to the eye; but it’s not purchasing a dollar’s worth according to the standards of ten years ago. Increasing wages will not help us. What goes in at one pocket goes out of the other. The man who receives a 50 per cent increase in wages, and who has to hand over to his wife 50 per cent more to keep the household going, is no better off than he was before. What is the solution? Once more we re- peat: increased production and more efficient distribution will bring down soaring prices YN sf ~ me

Page 52

ARK TWAIN’S immortal re- mark that, though much has been said on the subject of the weather, very little has ever been done about it is one of those epigrammatic asser- tions that will hardly bear ‘comparison with the facts. It is true that most people accept the weather philo- sophically as something that cannot be cured and most therefore be endured; but the aggregate of those who, from the earliest historic times down to the present, have declined to assume this acquiescent attitude would certainly populate a New York or a London. Attempts to reverse the law according to which man is subject to the caprices of the weather have taken an immense variety of forms, and have not always been un- successful. When a farmer plants a grove of trees around his house to serve as a wind- break he is in a fair way to modify the weather over a small area of the earth’s surface. When a _horticul- turist lights smudge fires in his orchard on a frosty night he certainly produces a kind of weather in the neighborhood of his trees that-would not have pre- vailed there if Nature had been left to _ herown devices. Every human dwell- ing provided with a fireplace, stove or furnace alters the weather within a few hundred cubic feet of the atmos- phere, producing an artificial summer in the midst of wintry blasts. We did not, however, set out to describe these small-scale experiments in weather-making. It is literally true that hundreds of thousands if not millions of human beings have under- taken to control such major phe- nomena of the elements as rainstorms and thunderstorms, hail, tempest and sunshine. Weather-Conjuring Is Not New In that wonderful record of human delusions, ““The Golden Bough,” Dr. Frazer devotes about ninety pages to a rapid enumeration of the superstitious methods of controlling the weather that have found credence among the various races of mankind. The art of rain-making was practiced by the Chaldean astrologers, who passed on some of their ideas and practices to the Greeks and Romans. To this day there is hardly a savage tribe to be Jostling the Clouds to Change the Weather Rain-makers, hail-preventers, and their “Electric Niagaras” are popular in France. A “Niagara” is a large copper lightning-rod, in- stalled in a church steeple or any tall build- ing. found anywhere in which rain-making, as well as other forms of weather- conjuring, is not one of the regular duties of the shamans or medicine men. Even the War Has Not Checked the ‘‘Hail-Rod”’ Man in Europe That faith in weather- making lingers even in highly civilized communities is easy to understand, if one con- siders the enormous value of good weather, in terms of dollars and cents, and the tendency of the wish to be- come father to the thought when [evidence is being weighed. Not a year passes without the announcement of some experiment in the pro- duction of rain in the semi- arid regions of our country and others. In Europe even the great war has not checked the erection of “‘hail-rods’’ and the discharge of precious ammunition against that per- ennial enemy of the farmer and vine-grower, the hail- storm. The campaign against hail constitutes the most striking chapter in the history of weather-making. The prac- tice of “‘hail-shooting” ante- 72 It draws down “torrents” of electricity is sent aloft by the discharge. to produce the desired hail-preventing effect strange devices dates the invention of gunpowder, Even in remote antiquity it was the custom to shoot arrows or hurl javeling at the gathering hail-clouds, and the firing of cannon to avert hailstorms was in vogue centuries ago in Styria and northern Italy, and was well established in France before the Revolution. Early in the nineteenth century a more popular ex- pedient was the erection of . hail-rods, or paragreles, con- sisting of tall metal-tipped poles connected with the ground by a cord or wire, These devices were imitated from lightning-rods, and were intended to draw off the electric charge from the over- hanging clouds, the idea being that without electricity no hail would form. At least a million of these rods were set up in various parts of Europe, Gassing the Hail Storm In recent times history has repeated itself, and both hail-cannon and hail-rods have been revived. The new vogue of the hail-cannon began in 1896, when a special form of mortar was introduced for the protection of The gun is mounted on a tripod. fitted with a long sheet-iron funnel. tile is fired, but a whirling ring of gas and smoke Its mouth is No projec- This is supposed

Page 53

ire, ted vere the ver= ing no st a set pe, has non The nin rtar n of is ec- ke ect October, 1919 Gunning for the Weather A Europe the new fashion of megaphone-like cannon began “Pail-shooting” is older than gunpowder; for even in in 1896. By 1900 at least 10,000 cannon had been in- remote antiquity it was the custom to shoot arrows or hurl javelins at the gathering hail clouds. Nowadays the _ stalled in Italy and 2,000 in Austria-Hungary, not to mention the hundreds erected in France. This picture shows an exhibition of hail cannon in Italy clouds are bombarded with special artillery. The old idea that cannon-fire precipitates rain dies hard. In

Page 54

Niagaras” was that installed in the famous Eiffel Tower some years ago che vine-growing district of Windisch- Feistritz, in Styria. The gun was mounted on a tripod, and its mouth was fitted with a long. sheet-iron funnel. No projectile was fired, but a ' whirling ring of gas and smoke was sent aloft by the discharge and this Was supposed to produce such distur- ance in the atmosphere as to inter- fere with the normal mechanism of the storm. The use of these gunsspread rapidly, until by the year 1900 at least 10,000 of them had been installed in Italy and 2,000 in Austria-Hungary, while they had also been extensively adopted in France. More recent explosive’ de- vices consist of bombs and rockets, which are claimed to be more effi- eacious than cannon because they concentrate their effects at the level of the clouds. Scientific commissions, appointed by the Austrian and Italian governments to investigate the various methods of hail-shooting, pronounced them worth- less. Apart from the results of actual experiments, there were two good reasons for arriving at this conclusion; one was that in no case did the explo- sions produce any appreciable agita- tion of the air at the great altitude where (as proved by its icy character) hail is formed; and the other was that even if the explosions should occur at such altitudes there was no reason to suppose the formation of hail could be prevented thereby. They Have ‘Electric Niagaras” in France About the year 1899 a new form of hail-rod was introduced in France, and this has since become the favorite means of. protection against hail in that country. It is essentially a large copper lightning-rod, in- stalled in some cases on church steeples or other buildings, but more often on tall steel towers erected for the purpose. This device is fantastically called an “electric Niagara,’ because, ac- cording to its promoters, it draws off “torrents’’ of electricity from the clouds. About one hundred Niagaras have been installed in France, some of them being set up in rows across the habitual paths of hailstorms, when they constitute so-called “barrages.”’ Their construction and the observations of their effects have been carried on under the direction of a special com- mittee appointed by the French Government. Similar devices have been erected in Argentina, and plans for intro- ducing them in South Africa were near consummation at the time the war broke out. The consensus of scientific opinion, however, strongly discredits their utility, and a propaganda against their use has also been waged, for obvious rea- sons, by the numerous hail insurance companies. Climate of the U. S. Worries Weather Wizards Other weather-making schemes have been numerous and _ varied. In the year 1845 a pioneer American meteorologist, James P. Espy, pro- posed the use of great fires in the western part of the United States in order to regulate the rainfall and winds to theeastward. The fires were to extend in a line of six or seven hundred miles from north to south and were to be set off once a week throughout the summer. Another genius proposed to de- stroy blizzards by a line of coal- stoves along the northern boun- dary of the country. Several plans have been put forth for producing wholesale alterations of climate. An early scheme of this character con- templated the damming of the Straight of Belle Isle, in order to improve jthe weather of New England and the Canadian provinces; wi while a few years since a proposal to build an enor- mous jetty eastward from N ewfound- land for the purpose of “protecting the warm north- flowing Popular Science Monthly Gulf Stream from the onslaughts of the ice-cold south-flowing Labrador Cur- rent”’ actually received serious atten- tion from Congress. Jostling the Clouds to Make Rain The rain-maker we have with us always. The ancient and apparently immortal delusion that rain can be produced by jostling the clouds with the aid of explosives received much encouragement in 1890-92, when ex- periments of this character were carried out near Washington and in Texas by R. G. Dyrenforth, with the aid of a Congressional appropriation. The experiments themselves were in- conclusive, but they helped keep alive an unfortunate fallacy. In 1911 and 1912 the late C. W. Post, of breakfast food fame, revived the gentle art of bombarding the clouds to produce rain and became involved in a lively con- - troversy with the Weather Bureau on the subject. In 1891 L. Gatham, of Chicago, patented a method of producing rain, which consisted of liberating in the upper air, by means of bombs con- trolled by a time fuse, quantities of liquefied carbonic acid gas. His idea was that the instantaneous evapora- tion of this substance would chill the air over an extensive area to such a degree as to condense its moisture and precipitate it upon the earth. This is but one of several proposed chemical methods of rain-making. From 1891 onward much was heard of one Frank Melbourne, known as the “rain wizard,’ whose procedure con- sisted of locking himself in a barn, freight car, or the like, and burn- ing or evaporating certain chemicals. Sometimes rain fol- lowed these experiments and sometimes it did not; but in any case the mysterious doings of Melbourne and his imitators furnished a lucrative attraction for county fairs and an adver- tisement to the railway com- panies, who have frequently subsidized the exploits of the rainmakers. The very latest rain-making scheme is reported from Australia, where the gov- ernment of New South Wales has financed the experiments of a man named Balsillie. His plan istosend up captive balloons to an altitude of a mile or more equipped to produce elec- trical dis- charges which are supposed to ionize the air sufficiently to promote con- densation. The hail-rod is the favorite protection of the French farm- ers against the hail

Page 55

7 =_—s . 1 © Rh 7 ie Bae eH Ill . a es OlCltCi<CSSCOCOS bal Ba a i oo A ee |

October, 1919 Decrease Your Waist-Line—Increase Your Life-Line What’s more you can do it without exercise N examination of 186,579 policy-holders in forty-three minutes a day what could ordinarily be accomplished only American life insurance companies has shown that the in an hour of unpleasant gymnasium exercise. Inside of a heaviest mortality is found among men and women who are cabinet is a fixed, wheelless bicycle. You enter the cabinet, between forty and forty-four years old seat yourself in the saddle, close the and who are from fifty to eighty doors after you, lower the top so that pounds overweight. In other words, pote howd only your head protrudes through an the overweight man or woman of adjustable neckpiece that fits snugly middle age is likely to die prematurely. around your throat, and start to If you want to live long, get rid of pedal.

the fat around your waist line. ’ 3-POINT SWITCH Within the cabinet is an electric In the face of these facts, physicians ma 4 gy panel heater. The heat can be controlled by have long preached the gospel of exer- : 1 tHermometeR thrusting your hand through the top cise. The body must be rid of the wastes that clog it and poison it. A man is a moving animal. But most of us don’t move—don’t exercise. We haven’t the time. There are many duties that keep us at our desks. Our waist-lines increase, and our life-lines decrease. We “put on fat,” as the saying goes; we do nothing to elimi- nate the poisons that mean kidney trouble, high blood-pressure, harden- ing of the arteries. We grow old before our time. All this we have been, told over and over again. “I have no time for exercise,” we say. cover and pressing. switch . buttons within easy reach. In a few minutes you are perspiring freely. You enjoy all the benefits of bicycling and all the benefits of a Turkish, Roman and Electro-therapeutic bath. In a word, you rid yourself of your clogging poisons and your superfluous tissue; you keep “fit”; you do not age be- fore your time. The bicycle is provided with a brake which can be adjusted in accordance with the amount of physical effort that you are able to put forth. In Mr. Cooper’s opinion, the daily use of the hill- What is wanted is a time-reducing The machine invented by Jack Cooper, climbing muscles for fifteen min- method of exercising. Jack Cooper, trainer of thousands of prominent men utes a day, accompanied by gen- of Stamford, Conn., who has trained and women, for reducing fat. Inside erous perspiration, will keep a busy thousands of prominent men and of a cabinet is a fixed, wheelless bicycle man or woman in condition. That is z : and an electric heater. Exercise on . a women, has met this need by invent- the bicycle causes profuse perspiration why his machine assumes the form of a ing an apparatus that does in fifteen which throws off clogging poisons stationary bicycle. Burglars Have Crossed One Bank Off Their List “@* TEER clear of the Pullman Trust and Savings Bank,’”’ what goes on inside the bank as well as in the street. one Chicago bank robber says to another these days. They are equipped with shot-guns and high-powered They have heard about the steel sentry-box that was rifles that fit through loopholes and point coldly down at recently built on the front of the bank the street and bank floor below. The because of the many hold-ups in the

loop-holes are large enough to allow neighborhood. The box is half inside the guns a wide range. Guards are and half outside the building, so that a » stationed in the box, day and night the guards who stand in it can see . fae ’ so the burglar’s chance is zero.

ae Me BE we { 4 ye ct : — om -, {P. ag -<e 2.65 4 dt i ~ anes = | & \

Better look honest or the sentry Day and night the bank is guarded The inside of the bank is just as might think you are a bank thief by sentries in this steel sentry-box formidable to thieves as the outside _ 15

Page 56

ALKING the plank—a source of innocent merriment and an easy way of killing captives, greatly indulged in by the pirates of yore— has been revived. But, fortunately, the victims now are mice and the plank is part of a mouse-trap in- vented by Humbert Pierini, of Greenville, Miss. The trap is divided into three sec- tions: the first is simply a block of wood, which is fastened to the edge of the table after the manner of a meat-chopper. Next comes the plank, and lastly the stand on which the bait is placed. The mouse on the table smells the bait, and rushes across the plank to reach it. But when he has just passed the half-way mark, the plank tips over and drops him into a waiting pail of water. The plank then swings back to its natural position and is ready for another Still Another Mouse-Trap to Add to Your Collection Popular Science Monthly victim to walk the deceptive plank. The plank tips under the weight of the mouse because the balance of the plank is disturbed. It swings back into place because the end near the table is slightly heavier than the far end. One enthusiastic user writes: “Man! That trap simply mops up the mice. We caught twelve one night, nine another, and six another night.” I hope that everybody who has small children will kill their cats and buy these traps.” Rather hard on the cats, but an excellent recommendation for the mouse-killer which, by the way, will not catch rats, we are told. The unsuspecting mouse trips across the plank toward the bait—but he will Why? Perhaps because the rat is never get there; for after he passes so long that its front paws have nosed half-way mark the plank tips reached the bait before its hind and drops him into a pall of water. paws pass the turning point; but original position, ready for another most likely, because rats swim and victim to venture confidently on it are remarkably good climbers. The Wonderful 535-Foot Deck 4 4 ——— i“ COLLAPSIBLE MASTS 5 SS FOR WIRELESS | 7 PILOT HOUSE ELEVATOR. Yi ~ HE seaplane-carrier Argus is the latest thing in airplane Vo — eee East EN mother ships. For her entire length of 535 feet, the flying- ‘ *\) S| deck upon which the seaplanes.start and land is entirely free from ; Sor a all obstructions of any kind whatever... In this respect the vessel is more advanced than the battle-cruiser Furious, which has been described and illustrated in the POPULAR SCIENCE MONTHLY, because the Furious had such obstructions on the flying-deck as her tripod mast, navigating bridge and stack. The most important of the new ideas worked out to make the free flying-deck possible are horizontal smokestacks, which are placed directly beneath the flying-deck and discharge their smoke from the extreme rear of the vessel, where it does not interfere with the beginning or ending of the seaplane flights. Another

Page 57

ill ESE EES | i SS a ee iis, SOMME 1e 4000 0 October 1919

How F you want to build a I house for yourself, and cannot afford to pay for having it done because of the present scarcity and high cost of labor, you can do one of two things: give up your plan for the present and wait until you have enough money or until the cost of labor drops to a more reasonable level, or follow the example of the man in Newark, N. J., who built himself a house by his own labor, assisted only by a few friends and a small tractor. The accompanying pic- ture illustrates his method. The basement part of the house is of concrete, the rest of framework. The enterprising builder cut and

ELEVATOR! 30X36 FT. By — ere

One Man Beat the High Cost of Labor

fitted the framework, and, assisted only by a few friendly neighbors, hoisted it into position by means of a small tractor. The illus- tration shows how he raised the complete framework of one side of the house to its proper position. The tractor, shown in the foreground of the picture, supplied the power, and the neighbors guided the posts to their proper places in the concrete base. In all probability it would have required the services of fifteen or more carpenters and building workmen to complete the work done by the owner, assisted by his

EVATOR WITH —< UNDER-DECK TRAP DOORS ‘18x60 FT. EL friends and the little tractor, Nothing like a little tractor and a few helpful friends in approximately the same to beat the scarcity and high cost of building labor time. of the Seaplane-Carrier “Argus”

LANDING 7 LIGHTS

new feature is an elevating pilot-house, the top of which is flush with the floor of the flying-deck when flights are in progress. When the vessel is under way, the entire pilot-house is raised high above the deck on four stilt-like legs, so that the officers may see to navigate more easily than from the permanent navigating bridge, located below the flying-deck. The Argus was not designed as a seaplane-carrier. She was built in Great Britain for an Italian shipping company, and was taken over soon after the war broke out. The construction of the flat flying-deck is the most conspicuous change made in the design. This deck runs her entire length, and extends for her clear width of sixty-eight feet. The flying-deck is built above the highest or top-most deck of the boat as originally designed, and is mounted on a series of vertical column-like plates with 77 suitable braces, so that the space between the main-deck and the flying-deck is left as open as possible. This was done because wind-tunnel tests conducted by the Admiralty had shown that the best results could be obtained when driving the vessel at speed by leaving the flying-deck as open as possible. The Argus has a maximum speed of twenty and three-fourths knots and a service speed of twenty knots. The next most noticeable change is the horizontal stacks as shown by the broken-away sections of the ship. In the space between decks ordinarily used for cargoa great hangar has been built, capable of holding twenty service planes of the largest type. A thermo tank heating unit is provided, also racks on the walls for torpedoes and radiators to keep the hangar warm, so that men can work in it comfortably even in the coldest North Sea weather

Page 58

Popular Science Monthly « A Visit to Davy Jones’s Locker Going down in a submarine—Walking on the bed of the ocean—How the war’s lost ships are to be recovered ETTING down into = thesubmarine Argo- naut is no very diffi- cult process. You clamber _. up into an open hatchway at the front of the Argosy, ) and find yourself at the mouth of a huge steel pipe, four and a half feet in diameter. Descending the pipe is a good deal like go- By Lloyd E. Darling HIS article takes you down in Mr. Simon Lake’s new salvaging submarine, the “Argosy”? and “Argonaut.” The character of this vessel, or combination of vessels, is made apparent from the drawing. With vessels of this type the bottom of the ocean is to be explored, cargoes and ships sunk during the war recovered where possible, and salvaging work in general carried on. The buccaneers of old could get no more wealth than now lies on the bed of the ocean awaiting our hand. Mr. Simon Lake gave us the opportunity of inspecting his craft and of actually walking on the bottom of the sea. The machine is exceedingly practical.--EDITOR. the approximately fifteen pounds per square inch al. ways on the earth’s surface. If the door has an area of 875 square inches, as we figured, and there is a push of 10.85 pounds on each square inch, it appears that there is a total of 8,750 pounds pushing on the whole door, roughly—about ing down an ordinary stair- way. Really, it is a kind of half-ladder, half-stairway. Angle-irons riveted to the wall are the steps. After descending about ten feet you find yourself at an elbow in the pipe. It stops going straight down and heads off toward the Argonaut, the particular angle downward depending on the amount she happens to be submerged at the moment. Electric lights illumi- nate the passageway. At the far end is a steel wall barring progress. At the right, however, and within the huge joint which holds the access tube to the Argonaut, there is a round opening, about two feet in di- ameter, which leads to the ‘‘air-lock,”’ a chamber about seven feet long, three feet wide, and four and a half feet high. At the far end of the air-lock is the door leading to the actual working chamber itself. This door is closed. There is a heavy air-pressure on the other side— ‘needed to prevent the water from entering through the hole in the floor of the workingehamber. This is ~ bang —” aac BYe BD “J fe OPEN BoTTOM COAL PUMPING TUBE about four feet by two and a quarter feet in size. Through it the actual operations on the bottom of the ocean or on a submerged ship are carried on. As is evident, the air-pressure in the little room you have just crawled into must equal that within the actual working chamber itself, or you would never get the door between the two open. This is precisely what this little room, the “‘air-lock,”’ is for. Like the lock in a canal through which a ship passes to gain a higher level, so this air-lock exists to raise the air-pressure that surrounds you up to the higher level of that within the working cham- ber. The door between you and the latter is thirty-eight inches long by twenty-three inches wide—say 875 square inches in total area. For every foot that one goes down into the water, the pressure increases by .434 pounds. If one were down 25 feet then, the pressure would be 10.85 pounds per square inch more than trolled. Ze" Boove is Argosy; at left Argonaut Divers go out from the compressed air cham- ber—here also the sub- merged derrick is con- The bottom of the chamber is per- fectly open to water, air-pressure holding the waves back. Coal from the hold is pumped through the tube shown—often costing only fifty cents a ton delivered on the barge at the surface four and a half tons! Obvi- ously you couldn’t get the door open and yourself into the operat- ing chamber without the use of this in- tervening air-lock. Using the air-lock, one can get up a balancing pressure and overcome the four and a half tons. Once inside the air-lock, the door is closed behind you. It is locked from the inside. Simon Lake seizes a piece of heavy iron bar lying on the floor, and pounds the door and the locks even tighter. This is to make sure no air escapes. He then turns a valve. It gives you a creepy sensation— turning that valve. You know how a chicken must feel when he sees the axe descending. But it is only momentary. /. & COAL PUMPING TUBE Ke = Derrick shown holding coal tube also elevates cargo to surface. In comes the air. P- tsh-h-h—sh-h-h-h-h-h-h-h-h. It is the same kind of a sound, though not quite so great in volume, that a locomotive makes when it draws up to a station and the safety valve starts to blow off because the engi- neer is no longer using the steam in his cylinders. In that little room the noise is deafening. Suddenly the air is shut off. Inthe meantime you pee

Page 59

teen h al. face. a of 3 we push each that 750 the bout /bvi- ; the prat- s in- lock, sure ons. or is from yiece loor, ocks sure alve. yn—- wa 1 axe ary. tube face. h-h. yf a e so ta n it and 3 to ngi- the ers. the hut you October, 1919 have been swallowing, pinching your nose, and endeavoring to get the Eus- tachian tubes that lead from your throat to your ears under the same air- pressure as that coming into the room. Otherwise your ear-drums would pro- test unmistakably against the pressure. Mr. Lake has shut off the air, so you may have a few moments in which to accustom yourself to the increased pressure. Then he reaches for the valve again. P-t-sh-h-h-h-h! On it comes again. In a few moments it begins to-lose its sharp whistle, eases off into a long- _ drawn-out sigh, and then ceases alto- gether. The reason for this is that the air has been coming from the working chamber, and now ceases because the pressures in the two rooms have become equal. Obviously it should now be possible to open the door connecting the two. You find that Mr. Lake is already pounding on the door’s latches. A few more pounds, and presto! the door swings open. The air-lock has served its purpose —let you conquer the barrier. You and the others scramble through the opening. You find yourself in a little steel-riveted, steel-plated room, shaped as to floor and ceiling a good deal like the bottom of a flat-iron, and about seven feet high. In reality it is the prow of the under-water boat. This accounts for its triangular or flat-iron shape. The Hole in the Floor But the thing that attracts your attention above all else in the room is a hole in the floor about two and a fourth by four feet. There is water in that hole. There are all kinds of for anything that may come along. Look! Here comes something crawling over the bed of the sea. It looks like an army tank headed for somewhere. It has a big horseshoe- shaped shell, and you can’t see any legs, or wheels, or anything under it. You wonder how it gets along. Down shoots Mr. Lake’s spear and Mr. or Mrs. Sea Tank is impaled as easily as if Mr. Lake had been aiming for the middle of a fried egg with a table fork. Up comes spear, sea tank and all. It proves to be a huge horseshoe crab, more than afoot across. What appear to be about two dozen legs wave wildly _ from each side of the shell as you pull tion of heaviness, it is not noticeable. Standing in that chamber and look- ing through the opening in the floor, one can realize very readily how it would be if one happened to pass over asubmerged wreck. Nearly the whole vessel would stand out as plainly as a board at the bottom of a brook. It is really remarkable how much light gets to the bottom of the sea at ordinary depths. Most sea water, Mr. Lake says, is quite clear, in’ spite of the fact that one has a hard time realizing it when trying to look down into it from a boat at the surface. In Southern waters, particularly, one can fre- quently see two or three hundred feet with ease. To Salvage Wrecks Had there been wrecks close ‘at hand in Bridgeport Harbor, it would have been possible to get over one, and perhaps walk on its deck. As it is, you may take off your shoes and stock- ings and stand in the opening, walking on the bed of the ocean as the submarine moves along. You can get a very good idea of how easy it would be to size up the condition of a sunken ship, get things from its interior, send out divers, and otherwise work with it, almost as easily as if it were but two or three feet under the surface. You have to concede that Simon Lake has turned out an exceedingly practical contrivance; and one of strik- ing originality. What Mr. Lake is going to do with his Argosy and Argo- naut is perhaps best made evident by the following quota- tions from his book, “The Submarine in War and Peace’”’: Somewhere off Bridgeport, shells lying down there, stones, and many weird objects. It’s the bottom of the ocean you’re looking at. some kind of sea-denizen that probably calls himself a crab of asort heaves into view. He has a shell on his back, and four or five legs sticking out on each side, and all told, legs and all, he is about as big as the palm of your hand. Evidently local society down here dis- dains to go forward and backward as is the custom in regions above, for he or she locomotes sideways, and really can dart through the water at a re- markable pace even though side- stepping it all the while. Interesting customs the natives have down here. A fish comes plowing into view. He apparently doesn’t like the scenery just above him, and veers off and out of sight. It’s lucky for him he did, for Mr. Lake is already standing over the opening, waiting, a spear in his hand, ing fish and other sea denizens. back water at his feet—otherwise it would fill the From such an under-water room sunken vessels may be salvaged, oysters and clams gathered and a variety of other under-water work carried out Suddenly eoame, Simon Lake standing on the bed of the ocean, spear- it off the spear. You put the crab bottom upward on the floor of the boat where it can kick up its heels to its heart’s content, and no harm done, for it is in the same predicament a turtle is when turned over on its back. ’ It dawns on you that you have for- gotten you are under considerable air- pressure. It has all been so interest- ing, looking down through that open- ing on to the bed of the ocean, you have forgotten all about anything else. The truth is, the air-pressure within the far corners of your lungs, and at the back of your ear-drums has be- come the same as that within the room, and, except for a general sensa- 79 Air-pressure holds Conn., lies the wreck of the old Sound steamer Lexington. Tradi- tion has it that she has a fortune in her safe. Many a ship has been sunk in the waters about Hell Gate; search was carried on there for years for the old British frigate Hussar, which struck on Pot Rock and sank during the Revolution- ary War. They tell that she had four million dollars (£820,000) in gold on board to pay off the British troops, and that she carried this treasure to the bottom with her. There is a cargo of block tin in a barge somewhere off the Battery, New York, and many a ship with valuable cargo lies along the coast from Newfoundland to Key West. The yearly loss in ships and cargoes throughout the world has always run into many millions of dollars, and since the war this has been multiplied a hundred- fold, amounting to billions. The time will come when many of these ships will be found, and such of their cargo as is still valuable will be salvaged. “Ships like the Argosy and Argonaut will get this booty,” says Mr. Lake.

Page 60

2 Popular Science M. onthly Do It with Tools and Machines Much of the time lost in run- Electrically heated glue-pots ' ning back and forth in a have some advantages not ——— . we -\ wood-working shop may be possessed by the ordinary ni : avoided by the use of this types. They are free from light motor-driven bench saw smoke and soot and flame An inexpensive hand culti- vator in the form of an at- tachment toa gardening hoe © Internatioaal Film Service This machine is able to load or unload freight on a ship in less than helf the time that it formerly took. The freight is just dropped on the conveyor Exit the hand forge, enter the electrical rivet-heater, which turns out four hot rivets, ready , for use, at a time An unbalanced motorcycle engine as it is used for tamiping newly-poured con- crete. This is one of the latest devices in modern -pAavement-construction A safety brake for the man-power truck is something that has been long wanted. It is operated by foot and holds the truck securely when pulling on the load A hand lantern so constructed that a movement of the handle lights or extinguishes it.. Long- lived four-cell batteries are used Acontinuous stroke band-saw for cut- ting metals. Bya spring at the back form of chips and of the machine shavings. A forced the feeding weight air draft does it is kept constant This machine sep- arates finished parts from the waste metal in the

Page 61

‘uck ted. the load October, 1919 Making Things Easier for the The key-fastener is secured to the door-knob. It is so constructed that it snaps to the key in the lock and prevents the door from being opened on the outside Made from a steering column and wheel of an automobile, this lamp is a distinct novelty in that it is the only one of its kind Busy Housekeeper After the hair is washed, this frame is placed under it, allowing whatever air is moving to circulate through the hair and dry it in half the usual. time A decided novelty in collar buttons is this new one, which, when in position, folds neatly against the collar-band, doing away with that unsightly bunch at the back of the collar ‘“‘When shall I give the next dosé?”? doesn’t bother the nurse who has this medicine bottle; it has a dial and pointer which designates the time for the medicine to be given again When the..owner of this tooth- brush finishes cleaning his teeth, he dips it into the sterilizing liquid and sets it into its holder Just big enough for two is this Picnic basket, which accommo- dates a small piece of ice for keeping the food and liquids cold Water is kept moving in the washing-machine on a horizontal plane. It has no internal mechan- ism to get out of order and impair its efficiency If there is a chair in the house that is wabbly, then why not attach a tin bottle cap underneath the bot- tom of the short leg to steady it ? The water is forced through the fabric of the clothing and cleans with- out injuring it. The motor and driving mechanism are entirely enclosed

Page 62

' Pegasus. Finding Your Way Among the October Stars Popular Science Monthly » ™ How the characters of an ancient legend may be found in the skies books say, there ruled a great king in Ethiopia whose name was Cepheus. His queen, as beautiful as she was vain and as vain as she was beautiful, was called Cassiopeia. Their daughter Andromeda was as beautiful as her mother. One day Cassiopeia was combing her hair as she sat by the seashore. In the hearing of certain sea nymphs she boasted that their beauty could not compare with her own. The sea nymphs, in revenge, succeeded in having a terrible sea- monster, Cetus, sent to ravage the sea-coast of the kingdom. To avert this great danger, Androm- eda was chained to a rock at the waters’ edge as an offering to the monster. Now, it chanced that a noted war- rior, Perseus, was just then returning from a great con- quest. He had succeeded in cutting off the head of Me- dusa, whose hair was composed of writh- ing snakes. One glance at her face turned the observer to stone. Calling to An- dromeda not to look around, Perseus came up, cut her chains, and carried her off on his winged steed ne () re upon a time,’ as-the story In the course of time, Cepheus, Cassiopeia, Andromeda, and Per-) seus, together with Cetus and Pegasus, passed the way of all things here below, and on death were transported to the Bkies and given places among the stars. Looking directly overhead in the early evening of October, a great square can be seen. This marks the position of Pegasus. The other constellations may be picked out by using the circular star map. Trac- ing north through the two most westerly stars of the square, three times their Looking directly overhead in the early evening of October, a great square can be seen, marking the position of Pegasus By Ernest A. Hodgson distance brings one to the constellation Cepheus. A similar tracing through the easterly pair picks out Cassiopeia—a great W. Tracing southeast diagonally across the square brings us in about the same distance to Cetus, while tracing northeast SOUTH HORIZON The Star Map for October The map represents the sky as seen at the times listed below. It is specifically arranged for the latitude of New York, but is practicable for ten degrees on either side of this latitude. September 6, midnight. September 14, 11:30 p. m. September 22, 11:00 p. m. September 29, 10:30 p. m. October § 7,1000p.m October 15, m 9:30 p. October 22, 9:00 p. m. October 30, 8:30 p. m® November 6, 8:00 p. m. November 14, 7:30 p. m. November 21, 7:00 p. m. November 29, 6:30 p. m. December 7, 6:00 p. m. The magnitudes are indicated on the nap by stars of various kinds as follows: 0 magni- tude, open center; 1 magnitude, 8 points; 2 magnitude, 6 points ; 3 magnitude, 5 points; 4 magnitude, 4 points; 5 magnitude, single dot. All times expressed in Eastern Standard (not summer) time. 82 across the diagonal indicates first Androm- eda and Perseus. Pegasus is the best placed of all these constellations for observing in October.’ The uppermost easterly star belongs to the constellation Andromeda. It is Alpha of that group. Alpha Pegasi is the star in the southwest corner. It is also called Markab. The northwest star, Beta Pegasi, is named Scheat, and the remaining star Gamma Pegasi, has the proper name Algenib. Epsilon Pegasi, the star at the western apex of the triangle, is a wide double. It appears asa single star unless viewed in a telescope. Yet its separa- tion is really great, as such measures run in as- tronomy. When the planet Uranus was discovered by Herschel, its path was computed from many observations. We usually think of the paths of the planets as_ being smooth ellipses. It was found, however, that Uranus wan- dered from his com- puted place. This wandering was by an amount equal to that which separates the two components of Ep- silon Pegasi. Yet as- tronomers considered it serious. Two men, Le Verrier of France and Adams of England, sat down independently to solve the following problem. Given that Uranus wanders from its computed path by this small amount, and assum- ing that this wandering is due to the at- tractions of a near-by and hitherto un- known planet, determine the position of this planet. Adams solved the problem and pre- sented his solution to the astronomer Royal of England. The latter, thinking little of the ambitious attempt of the young astronomer, laid the manuscript away and forgot it. In the meantime Le Verrier solved the problem too, and sent his solu- tion to his friend, the German astronomer Galle, telling him just where to look for the new planet. Galle found it the first evening he looked for it. Look now at the little star Epsilon Pegasi. If you are fortunate enough to possess a good field-glass, examine the star with it, and you will see it twinkle into two. Think then of the precision of astro- nomical instruments which permit astron- omers to detect such trifling, and yet such significant, discrepancies in the paths of the heavenly bodies. There are today discrepancies noted in the path of Neptune. Will a future Adams or Le Verrier compute for us the position of a ninth planet? Time will tell. HORIZON WEsT

Page 63

ib. the isa Sa na Ta- ich lve nat ted m- at- in- re- 1er ing ng nd ier lu- 1er for rst car The Planets for October

HOSE who wish to view the planets in October must Was rise early enough to see them before sunrise. All i. glk will be invisible till then. Of the brighter planets Jupiter will rise first, about three hours before the sun. Then Mars, Saturn, and Venus follow in the order named. The last rises about an hour and a half before the sun, and appears low in the east—a morning star. Examining the planet map, we note that the moon crosses the ecliptic very close to the point where the earth’s shadow has come by October 31. By the time the earth’s shadow reaches this crossing point, November 7, the moon will again reach this same spot. Then, instead of crossing above the shadow as it does this month, it will cross the ecliptic behind the shadow, and there will be an eclipse of the moon on November 7. It will be seen, too, that the sun is coming close to the position on the ecliptic, where the moon again crosses. This month the moon passes below the sun. Next month by November 22 it will again come around to the crossing . < BES , point of the ecliptic just in time to pass in s Sen S/o Ee) front of the sun. There will be a partial x / Al eclipse then of the sun on November 22. The manner in which the moon just avoids the conflict with the earth’s shadow and with the sun this month, and the way in which they are NY about toreach the crossing point together next month NSS can readily be seen on reference to the above map. ig Sew 4 There will be a conjunction of the moon with Jupiter ~* on October 17, with Mars on October 19, with Saturn on October 19, and with Venus on October 19. There will be a conjunction of Mars and Saturn on the 24th. Venus, the morning star, attains its greatest brilliancy on October 19. Locating Venus on the morning of October 19 by To use this planet map, cut out the disk below and means of its brightness, you will recognize the other planets use it as explained in ‘‘How to Use the Planet Map”’ from their relative positions as given in the planet map. The time of the various phases of the moon may be com- puted by the method outlined in the June issue. The year number of the computation is 11 times 1919 minus 1911, or 88. The month number as picked out from the list JF MA M J JA so ND 02 0 2 24 5 6 78 9 10 is 8, and the sum of 88 and 8 is 96, which is 6 more than an even multiple of 30. Hence the moon is 6 added to 1, or 7 days old, on the 1st of the month. This, then, is first quarter. It is fifteen days old on the 8th, i.e., it is then full. It is thirty days old, or new, on October 24, since 24 added to 6 makes 30. These dates are all correct, as can be veri- fied on reference to an almanac, with the e) | exception of the last one, which is nearly | a day out. The rule can only be trusted | | 6

Oz Zuo <j Xe + ¥ XIx xvi HEE He rN

fe a 4 ’ g c 4 2s y

*y + ee aT; < J 1)}29 a, - ieee 2

{ ou pe TCT ta angen te ty DP within a day, however, and that is quite sufficiently close for all general purposes. How to Use the Planet Map HE planet map indicates a belt thirty degrees wide on each side of the celestial equator. To use it, cut out the circular disk to the right and mount it on a thin cardboard disk of the same size. Run a glass-headed push-pin through the center of the disk, pinning it to the center of the map. ; To see the section of sky visible at any time on any given date, turn the disk until the required hour on the disk is opposite the required date on the chart line of the “mean sun.’’ To see when any celestial body rises or sets or reaches the meridian on any date, turn the disk so that the position of the body for that date on the map is in the required position with respect to the hori- zons. Read off the hour opposite the posi- tion of the mean sun for that date.

Page 64

The mail-pouch was container, and the in a chute on the ing bost. Two hundred feet of from the container behind the placed in an outer whole deposited side of the fly- ceble trailed flying-boat The branched and.weighted lower end of the cable caught in the stay running between the fore mast and the fore mainmast. Since the flying-boat was travelling at the-rate of about seventy miles an hour, the lower weighted end of the cable was whipped around the stay, _thus jerking the mail-b2g out of the chute in which it rested on the flying-boat. The Adriatic was making eighteen knots—her full speed ahead In accordance with the prog- ram the bag dropped into the water and was hauled on board the ‘Adriatic by the very cable which hed served to jerk it from the fiying“boat. The mail, of course, was packed in a stronz waterproof floating Dreadnaught pouch Ya, \ 3 f « eR | | H Popular Science M onthly\ How the Popular Science Monthly By Waldemar In order to save the time now lost to England, the Poputar Science be overhauled by airplane and press. her. Read here how the experi- UPPOSE you have a contract involving hundreds of thousands of dollars, and suppose that that contract must be signed in London by acertainday. The steamer has just left New York. She is seventy- five miles out at sea. Jf you can catch her and drop that letter of yours aboard, it will mean a fortune to you. If you must wait for the next steamer, a delay of perhaps a week is incurred, and all the work that you may have done may go for naught. And then, consider the delays incurred by waiting for ships’ manifests to be made out. It costs hundreds of dollars a day to hold a ship at the wharf; and yet, she must be held thus for papers until the last bale is taken aboard. Often the delay involved in: getting the papers from the Customs house amounts to half a day. If the ship could sail and receive her papers at sea, it would mean dollars and cents to her owners. The airplane at once suggests itself, Why not send a flying-boat out to the ship at sea and drop a mail-sack of late mail on board? The Post-Office Carries Out the Popular Science Monthly's Idea This Idea of the POPULAR SCIENCE MONTHLY was brought to the attention of the Post-Office Depart- ment. Mr. Otto Praeger, Second Assistant Postmas- ter-General gave _ instruc- tions that the PopuLaRr SCIENCE MONTHLY’s idea should be carried out experi- mentally, and Mr. Thomas Patten, the Postmaster of New York, was instructed to cooperate with us. Through the courtesy of Mr. David Lindsay, of the International Mercantile Company, the White Star Liner Adriatic was placed at the disposal of the PoPULAR SCIENCE MONTHLY. Mr. Inglis M. Uppercu, President of the Aero Marine and Engineering Company, generously supplied one of his areo marine flying-boats. After the preliminary ar- rangements were made, the Post-Office authorities, the Aero Marine Company’s engi- neers, and the POPULAR SCI- ENCE MONTHLY’s editor held a conference in order to devise a safe and sure way of dropping the mail-pouch on board the Adriatic. It was finally de- cided that the Adriatic herself must in some way cooperate with the flying-boat in the air. The delivery of the mail-pouch to her must be as certain, almost, as if it were hoisted on 84 + ¢, The lower end of the cable had seven branches, and each branch carried a two- pound bag of shot a) STAY SEVEN 2-POUND BAGS OF SHOT NG

Page 65

NCE eril- is of n by nty- Ours next you ts to , the thus aken d in: “oms the pers ents self. » the k of ries nce JLAR was ition part- eger, mas- truc- JLAR idea peri- ymas r of icted ional 1d at 3 M. any, i of even each shot October, 1919 . wn Dropped Mail on a Liner’s Deck Kaempffert by waiting for the next mail steamer MoNTHLY proposed that a ship at sea ing-mail matter dropped aboard ment was successfully carried out poard or carried on board from a wharf in the usual way. So it was finally decided that the mail-pouch was to be attached to one end of a steel aeroplane cable two hundred feet long. The other end of the Cyrus Zimmermann, the pilet, and Richard cable was to be provided with seven short branches, each weighted with a Sy an tine cow Geax oa ae ae two-pound bag of shot. Sailing over the Adriatic, the pilot of the flying- mail from sn sizplane: 6 steamers ak tea, boat was to trail this two-hundred-foot cable, swooping down within a So thoroughly had Zimmermann drilled him- hundred feet of the Adriatic’s foremast. self in the part he was to play that he de- The lower end of the cable, traveling at seventy-five miles an hour, was posited the mail sack on the Adriatic with- to strike the stay running either from the bow of the ship to the top of the out a hitch. His was the plan of attaching to the bag a two hundred foot cable which foremast, or the spring stay running between the foremast and the fore wrapped itself around one of the stays of the mainmast. At seventy-five miles an hour the cable would wrap itself Adriatic’ s rigging, a plan that proved feasible around the stay and jerk the bag out of a chute in which it reposed at the side of the flying-boat. Test to Make Sure the Plan Would Succeed To make sure that this plan would succeed, experiments were con- ducted at the works of the Aero Marine and Engineering Company. The pilot assigned to the task, Cyrus Zimmer- mann, a man who had given a brilliant account of himself as a civilian instructor of flying in the Army, rigged up on land a wire corresponding with one of the Adriatic stays, and then deter- mined whether or not it was feasible to jerk a hundred-pound bag of wet sand from a traveling flying-boat. The tests proved to be so highly successful that the system was adopted for the experiment. It was considered desirable to provide a shock-absorber of some kind in the two-hundred-foot cable. Traveling at seventy-five miles an hour, it was estimated that the wire would strike one of the stays of the Adriatic with an impact energy of twelve thousand foot-pounds. Accordingly, stout rubber-band shock-absorbers, of the kind that are used on airplane landing gears, were inserted in the cable. The draw- ing at the top of page 84 reveals so clearly how the shock-absorbers were placed that further explanation is unnecessary. Since it was foreseen that the pouch would drop into the water provision had to be made for keeping the mail dry. Hence, the mail was sealed at the New York Post Office in a floatable water-proof Dreadnaught pouch. The construction of this pouch resembles that of the Dread- naught life-saving suits worn by the British Trans-Atlantic Aviators. When the bag fell into the water it floated and was hauled aboard the Adriatic by the very cable that pulled it from the flying boat Captain Ranson, of the Adri- atic, who received the first package of mail ever delivered to a ship at sea by an air- plane. . What was in this epoch-making package? The answer is in his hands The aero marine flying-boat that delivered the first bag of mail to a steamer at sea

Page 66

toy, mero Se ee The bag of mail was sent by motor-truck to the waiting flying-boat two hours after the Adriatic had left her pier August 14, 1919, was the eventful day set for carrying out the POPULAR SCIENCE MONTHLY’s idea. A thirty- mile gale blew. It was one of the worst storms that New York had ex- perienced in weeks. The weather conditions were about as unfavorable for so bold an experiment as could be imagined. But if late mails with valuable documents are ever to be de- livered regularly at sea, wind and weather must be ignored. And so it was decided to proceed. Wrapped in Floating Package A water-proof mail-bag was es- pecially made for the experiment by the Safety-at-Sea Corporation. It was a water-proof rubber bag, made floatable by applying the same principle followed in making the Dreadnaught life-saving suits which have been described in the POPULAR SCIENCE MONTHLY. To drop a mail-pouch weighing one hundred pounds on the deck of a crowded transatlantic liner would be risky. Provision had to be made for dropping the mail-bag into. the water as close as possible to the ship. Hence the Dreadnaught water-proof floating mail-bag was selected. Two hours after the Adriatic had sailed, a pouchful of United States mail, and a package containing copies of the PorpuLAR SCIENCE MONTHLY, addressed to Captain J. B. Ranson of the Adriatic, were delivered to the flying-boat at the foot of Eighty-fifth Street and the North River. The mail-pouch was placed within a second bag, to which one end of the cable was attached. Heading into. the very teeth of the gale, Zimmer- mann sailed along fifty, one hundred, two hundred yards, and then vaulted into the air. Catching Up with the Adriatic Straight after the rapidly disappearing Adriatic the flying-boat speeded with its mail. Just off Scotland Lightship, near the end of the Ambrose Channel, Zim- mermann, in the flying- boat, caught up with the Adriatic. The craft, circling over the steamer like a great aquatic bird, provided a dramatic spectacle. De- ciding, finally, that the moment had come for the crucial test, Zimmermann swooped down with his cable trailing within one hundred feet of the Adri- atic’s mast. The lower shotted end of the cable caught the stay running from the foremast to the fore mainmast of the Adriatic. At once the mail-pouch was jerked out of the chute on the side of the flying-boat. The sack dropped into the water on the port side of the Adriatic, exactly as those in charge of the experiment had foreseen. In less than a minute it was hauled up to the bridge of the steamer by its own cable. There Captain Ranson opened the con- tainer, took out the package addressed to him, which contained ‘Popular Science Monthly. piloted. Compare this with the eighteen knots of Adriatic or the twenty-two or twenty-five knots of g fast turbine liner, and you see at oneg how wonderful are the possibilities, It is apparent, too, that the reverse proceeding is also feasible. The time is coming when every transatlantic liner will carry her own flying-boat. The banker or the lawyer who must reach shore hours in advance of the ship, the package that should be in the hands of some business house in New York or Chicago without a moment’s unnecessary delay, will be transferred by airplane. Running along on its own track on deck, after the plan adopted by the United States Navy on its battleships, the flying-boat vaults — into the air and speeds on, landing its passenger and its little bundle of freight five, ten, even twelve hours in advance of the ship itself. Day of Transatlantic Airplane Near? A far-seeing newspaper woman, who watched from a yacht at sea, the experiment of dropping mail upon the Adriatic made the comment that it was all very like overtaking an oxcart with an automobile. Isn’t the over- hauling of a steamship by a swift airplane soon ‘to become obsolete? The steamship will continue to plow the waters of the seven seas, if only because it is the cheapest carrier of bulk freight ever invented. It was the object of the POPULAR SCIENCE MONTHLY’s experiment to prove that the airplane can be made a useful adjunct of the steamer, and that object was attained when the first bag of mail was delivered to the Adriatic at sea long after she had left her pier. copies of the POPULAR ScIENCE MONTHLY, and distributed them to the officers and officials of the White Star Line on the bridge. Thus simply was the feasibility of applying the flying- boat for saving precious hours demon- strated. Drop Mail on Steamer Two Days Out There seems to be no reason why a steamer may not be overhauled when she is as much as a day or two at sea. Late mail and manifest papers could be sent to Boston or Port- land and there transferred to a flying-boat. Seventy miles an hour was the speed that Zimmermann made in the craft that he 86 The bag was hauled up to the bridge of the Adriatic, and Captain Ranson distributed copies of the PopUuLAR SCIENCE MONTHLY that had been delivered to him by fiying-boat

Page 67

Near? oman, a, the yn the nat it >xcart over- swift ) plow f only - ier of t was IENCE > that useful that first o the e had October, 1919 When You Live in a Duifle- Bag An autumn vacation in the woods By Charles Coleman Stoddard HE other day, when I was sewing up Joe’s pants behind the tent, I was reminded that I had carried a sewing-kit in the old camping outfit for more than two years without using it. Oftentimes it seemed a nuisance, and I was tempted to throw it out; and yet it is just these little things, useful only in such an emergency, that save a situation—perhaps a life—or unexpectedly add to our comfort in the woods. Of course, the prime purpose of camping out is to rid ourselves of many of the so- called ‘‘luxuries” of our convention- alized modern life. But this does not mean that one must live in camp like a cave man, or deny himself certain creature comforts that even the savage pro- vides for himself within his knowledge. What Is Indispensable ? It is presupposed that we will pro- vide ourselves with tents, or other shelter; that we carry with us blankets and a waterproof ground-cloth or poncho, or other sleeping equipment; that we have a cooking outfit and proper food. Clothing will vary with the locality and the season of the year; if we are to hunt or fish, arsenal and tackle must be put in order, and pack- straps, packs and duffle-bags made ready. The question now arises, what is in- dispensable?) Not how much do we want to take, but how much can we afford to leave behind? When we sit down to the contempla- tion of the almost endless array of articles offered in the catalogs of dealers the task seems impossible. Be sure that before you have finished, you will buy most of these things. Many of them you will discard forever; but from them, and from your own im- provisations, you will gradually sift out a selection of things that you will always pack or carry—the little things that make up the individuality of the _ Camper, and make camps to differ one from another. For instance, a few yards of mos- Mosquito netting attached to the tent will enable you to sleep comfortably quito netting, if your tent is not already screened. It costs little, weighs next to nothing, and occupies very little room in the pack. It is worth your whole outfit on a night when the unspeakable little nuisances are abroad. It also insures one of com- forting and restful sleep in the early morning when flies are likely to be troublesome. If we use cheesecloth or tarlatan, rather than ordinary cloth mosquito netting, it will keep out even the smallest insects, and we can have a light in the tent —never a safe ex- periment : without ‘such protection. But, even then, be certainthatall the openingsaretight- ly closed unless you crave com- pany. The illus- tration shows three lengths of dou- ble width material rigged to the fly of our baker tent with ordinary safety pins. The edges are rolled once to- gether and pinned making a tight seam. The bottom is tucked back under the ground-cloth, or held down with small flat stones, and a single seam is left open for entrance. If you choose to sleep without a tent, as you will often wish to doin the mosquito season—and one really has not tasted the outdoor life at its finest until he has rolled up alone under the stars—it is not necessary to swel- ter and to breathe foul air by cover- ing up head and arms with the blanket, and then securing only doubtful protec- tion. Set up two crotched sticks about eighteen inches high, one each side of the bag or blanket, about eighteen inches from the head of the bed; and across these, supported by the crotches, lay a straight stick. None of these need be thicker than the finger; but the two side sticks should be set firmly in the ground and all the ends carefully 87 Sleeping without a tent in mosquito time isn’t so bad if you do it this way smoothed with a knife, so that they will not catch in the meshes of the net and tear it. Place one end of the net smoothly on the ground, extend- ing for about a foot under the head of the bed or mattress; and, after you have crept in, draw the net up over the frame, letting , the foot fall across the blankets+then tuck in the sides. You may hear the marauders: making merry outside, but you may rest in peace’ with the assurance ‘that none will be able to reach you. ’Ware Damp Matches Probably, along with a compass and _ a good axe, the most necessary thing to carry into the woods is a practical, waterproof match-box. A single mis- step on a slippery log may tumble you into the water; or, if you have tramped all day in the rain, soaked to the skin, a dry match means a good fire, comfort and perhaps your life. A _ tightly- corked small bottle serves the purpose admirably; or, better, a brass shot- gun shell that can be corked tightly, for there is no danger of that breaking in your pocket. Either of these will do in an emergency. Several practical containers are on the market that will stand immersion for hours, even days. All have their good points; you may suit your fancy. My choice is one of black gutta-percha with a screw top and a soft rubber gasket. It is light and serviceable and has an added advantage in that it will float if dropped overboard, where a metal box would sink. Always, too, carry a liberal supply of matches in the pack, in a push- top tin or other watertight con- tainer, for a damp day or two in a camp is almost as fatal to matches as actual contact with water. A folding candle lantern — which weighs little and slips conveniently into the pack or pocket, and is always ready — with plenty of candles, will furnish safe, sane and adequate light. If you ever have attempted to pack kero- sene into camp, and have been forced to eat food flavored with it for

Page 68

§ Semen eee mepagE ne ene terete erence ee ane nacemearemnetan a 5. age? negra: a days afterward, you will join cheer- fully in the praises from thousands of outers who swear by this simple and nost useful of*cdamping contrivances. In it you can use any and all sizes of candles, and candles can be bought anywhere. .It. will not blow out, even ei > ale in a gale. It*can be dropped, over- turned and knocked “about without danger, and when folded will not grease or smudge off, or damage the clothing or the contents of the pack. Concerning Water Buckets My special thanks go out to the man who conceived the collapsible canvas What is vacationing without a canoe ? Every camp should have one or more water bucket. ' carried some distance into camp, and it is always convenient to have a quantity near the cook. fire. The cooking pots are too small, and usually in use; and if one is packing his camp on his back he cannot be burdened with the size and weight of a large utensil. These buckets are simply heavy, waterproofed canvas bags, similar to the feed-bags used for horses, with a round bottom, a wire hoop at the top, and a rope handle. The capacity is approximately three gallons. Collapsed, they are not much larger than a pie-plate, and two of them (dried out) weigh scarcely more than a pound. They also come witha canvas throat that ties at the top to prevent slopping, for canoeists and for carrying water for some distance, and, forautoists, withaspout. Forordinary purposes, however, the open buckets are more convenient. These buckets have another excellent point, in that they automatically keep the water cool by slow evaporation. If the out- ‘side is kept wet (and usually the weight of the water inside will slowly force a small amount through the canvas) and the bucket is hung in a moving current of air, a cool drink is assured. The Culinary Department Two dish-towels and a dish-mop will be appreciated by the cook. It is all very well to romance about scrub- bing greasy tinware with sand and cold water, but a pot of hot water on the back of the fire, soap and a mop, anda good dry cloth are better. Get a big, soft mop. If the handle is too long, cut it off to about four inches. A hole ' through the end of the handle, with a Often water must be loop of string tied through it, is handy for hanging the mop on a bush or tree to dry out. A combination can- opener and corkscrew, with an arrange- ment for opening capped bottles, is convenient. Or you may carry an Army or Boy Scout knife, which com- bines all these with a stout jack-knife and can be carried in the pocket. A flapjack turner is indispensable for fry- ing potatoes, serving eggs, and many other uses that its name does not imply. Get one of the convenient ones, consisting only of a broad blade, slotted at one end, which can be slipped on the blade of a cooking knife for a handle; or if you have one of the ordinary kind, with a long wire handle, | cut off the handle within about two inches of the blade and improvise a handle by using a split stick when you are in the woods. In the kitchen the problem of keep- ing one’s hands clean while cooking is not a serious one, but there one is not handling firewood, sometimes charred, and weil smoked pots, and waiter is always handy for washing. Over the camp fire, the best protection is a pair of ordinary cotton work gloves. Slip them on, after you have washed your hands, while working around the fire, and lay them aside when handling the food. They also serve as pot-lifters and protect the knuckles from the direct heat of the fire and wil! be found convenient when doing other rough work around camp. Always put an yi Yi ranwvt\\\s = My, yy _ Nt “4 Vf, : | il, \ ® 7 Apis 7 A\ vil ANN \( entity wt A bag similar to that one which carries old shoes will come in mighty handy j WY YH old newspaper or two into the pack— not to read:—God forbid! There are too many thingsin the woods to inter- est one to find time for that—but newspapers can be put toso many prac- tical uses around camp. And always hoard all the paper bags and other wrappings for packing when coming out. Burn all that you do not use before putting out your fire on breaking camp. An excellent way of keeping to- gether the little things is a glorified form of the old “‘shoe-bag”’ that used to hang on the closet door. This consists of an assortment of con- veniently arranged pockets, made of khaki, ticking, or some other strong, light-weight material, with tapes at 88 ‘Popular Science Monthly the top, by means of which it may be suspended from a tree limb, from crotched sticks, or to the wall of the tent. In these pockets are car. ried all the small articles of personal outfit and other little things likely to be easily lost. When we need them, they are conveniently near at hand, and when we have used them, back they go. In_packing, the whole bag is rolled together inside the blankets, or tied up and thrust into a corner of the pack-bag, and we zan be morally cer. tain that nothing is left behind. This bag can be made at home at the ex- pense of a few cents. This lean-to tent shields you from the sun and acts as a wind-break All soiled clothes should be washed out immediately, dried and folded neatly—not jammed “any old way” into the pack. Perhaps there is no petter way to illustrate the usefulness of this bag than to give an inventory, exclusive of some of the articles already mentioned, on a recent trip. In the small pockets: tooth brush and powder, comb, towels, soap, shaving outfit and mirror; asmall note book and pencil, and a few stamped postcards (the latter are always worth while, for stamps and envelopes are useless in camp, as the dampness soon sticks them together) ; sewing and medicine kits, extra pipe and tobacco, extra spectacles, films for camera, blanket pins, safety pins, matches, paper bags, sharpening stone, rope and string, wire, a few nails, repair kit and sewing awl. In the large pockets: extra shirt, extra pants, sweater, handkerchiefs, under- wear, socks, moccasins, and extra shoestrings. Don’t Forget Your Camera By all means carry a camera, and plenty .of films. Any of the small folding cameras are easily packed and will take all the pictures that you will care for. But don’t make the mistake of choosing too small a camera (you will-not want to make enlargements of all your. negatives). Remember, too, that a camera in camp, even a cheap one, requires some attention. Take all your pictures care- fully; if they are failures, they cannot be duplicated. Know your camera thoroughly before you take it into the woods—its exposures for ordinary light and shade, and its adjustments.

Page 69

lded yay y to bag re of ned, and ving and ards , for s in ‘icks cine xtra nket ags, vire, awl. xtra der- xtra and nall and you the ake es). 1 in are- not era the ary ss Cth E. a pee vl fe Wit in i RL SE, THE PULL OF GRAVIT: ~~ ARROWS. REPRESEN Ts es b Saeed ZEST Tracing the flight of a bullet Points in rifle shooting that you learn in the W. J. R. C. HE instant a bullet leaves the muzzle of a gun, gravity starts pulling it down, or making it drop. Atshort, point-blank range, this drop is Shar pshooter Medal slight. In longer dis-' tances, the drop depends upon the speed of the bullets. High velocity bullets drop but little since it takes them only a tiny fraction of a second to reach their mark. To take care of this drop, sights are fixed so that the rifle points somewhat above the. bull’s-eye, though the aim is dead straight. As a result the bullet travels in a curved path, or trajectory, as shown in the diagram above. Knowing just what sight allow- ance to make on long shots is one of the fundamentals of shooting that boys of the Winchester Junior Rifle Corps soon learn to master. Boys of the W.J.R.C. have a great advantage over the fellows who don’t belong to any recog- nized rifle club. They get all the shooting instruction they need to become real experts in the use of rifles. They have competent men to teach them all the fine points of shooting. Start a W.J.R.C. ‘‘Unit’’ with your friends _ Why not get together with half a dozen of your chums, join the Winchester Junior Rifle Corps and organize a regular Unit which will be officially recognized by National Headquarters? When you have enough Marksmen in your Unit, you will be matched against other Units. Any boy who gets a Unit started receives a Special Service Pin. The W.J.R.C. will help you from start to finish in rigging up an indoor or outdoor ‘range. It provides for officers, supervisors, and adult instructors to make your shooting safe. It costs you nothing to join the W.J.R.C. There are no dues and’ no military ob- ligations. The W.J.R.C. was organized solely to encourage better marksmanship and better sportsmanship among boys and girls of America. It is intended to develop the qualities of fair play and manliness which are essential to success in after life. Any boy or girl not over 18 and who is in good standing in his or her community is eligible. Membership ‘in the W.J.R.C.* covers ‘the entire United ‘States. There is hatdly. a town now that~has not at’ Isast a small Unit of the big National Organization where boys are learning to become expert riflemen and are competing for the famous Winchester Marksman, Sharpshooter and Expert Rifleman Medals.. You, -too, can earn these trophies of marksmanship if you join the W.J.R.C. and start shooting now. Get the official plan and rule book Write today for. the Winchester Junior Rifle Corps ‘‘Plan for organizing a W.J.R.C. Unit” and for the official rule book — ‘‘How to handle a rifle safely.” This booklet tells you all about the W.J. R.C. and describes in detail the fine points of shooting — alignment of sights, the three correct positions, rules for gun safety, the care of rifles, and the proper rifle for you to use. If you are a boy scout,. give your name in full, the troop you belong to and the name of the scout master. If you are not a boy scout, state what boy organization, if any, you belong to, giving the name of the official in charge. National Headquarters Winchester Junior Rifle Corps 275 Winchester Ave. New Haven, Conn., U. S. A. Division 1020 The following table gives the trajectory heights for the Winchester .22 Long Rifle Lesmok Cartridge at various ranges. When Height of Trajectory at Rangeis % Range Mid Range % Range 25 yds. ; 0.202in.; 0.275 in.) 0.203 in. 50 “* | 0.845 “* Loe 0.865 “* 100 “ 3.57 ** 4.86 ‘ 3.73“ 150 * 8.49 “ 11.68. “* 9.044 ** 200 “ 15.93 “ 22.12 “ ye Sin 250 ‘ | 26.24 * 36.76 * 28.96 * 300 * 1 39.77 “ 56.20 ‘ 44.62 * Standard types of .22 caliber Winchester Rifles, popular with members of the Winchester Junior Rifle Corps. WINCHESTER Take-down .22 caliber single shot rifle. A low priced, light weight gun made in two sizes. WINCHESTER JUNIOR RIFLE CORPS National Headquarters, 275 Winchester Avenue, New Haven, Conn., U. S. A. 24-inch octagon barrel. WINCHESTER MODEL 90. Take-down Repeating .22 caliber rifle, The standard target rifle for over 25 years.

Page 70

There Once Was a Lazy Sailor His pet aversion was washing clothes. So one day he fastened his clothes in an old net, and tied it to the stern of the moving boat. When he pulled up the net his clothes were clean. Thus we learn that it is not the rubbing of the clothes which cleanses them. It is the action of the water as it is forced through them time after time. 1900 CATARACT WASHER HE 1900 Cataract Electric Washer is built on this principle, but it forces the hot sudsy water through the clothes in a figure 8 movement. By this magic movement the water is forced through the clothes four times as often as in the ordinary washer! It is the figure 8 movement that makes the 1900 Washer the perfect washing machine. There are no parts to rub against the clothes, and no heavy cylinders to lift out and clean. The swing- ing, reversible wringer saves steps for it can be moved to any position without shifting the washer. Costs less than 2c an hour to operate and washes a tubful of clothes in 8 to 10 minutes. 1900 Washer Co., Binghamton, N. Y. Canadian Factory and Office Canadian 1900 Washer Co., 357 Yonge St., Toronto, Can. Even the wringer works electrically. Just connect it with the electric light socket. The water swirls i through the tub in a jigure8movement,and ave four times as often. No partsin the tub, and no heavy cyl- inders to lift out. Your clothes are not washed with other people's. Our Trial Offer ‘ You may prove to yourself before you buy it that the 1900 saves time, money and clothes. The 1900 dealer in your town will deliver one right to your home. After you have tried it out, you start paying for it on terms to suit your convenience. Come in 8 and 12 sheet sizes. 1900 WASHER COMPANY BINGHAMTON, N. Y. Please send me detailed information, and the name of the nearest 1900 dealer. Name Address. City and State. Popular Science Monthly Making a Door Hook Easy~ to Grasp ie f in common screw eye and hook, by means of which screen and_ storm doors are ordinarily fastened on the inside, is frequently the cause of much annoyance. The hook turns ~ around on one ee side and lays flat against the cas- {4 ing. When it is located high in the doorway, it is often impos- sible to get hold of it with the gloved hand. The illustration shows how a piece of wire or sheet metal can be soldered to the hook to turn or lie flat against : thedoorway and [The elusive door hook : ss is kept in position by It will always 4 wire soldered to it stick up so that it may be readily grasped with a gloved hand or in the dark.—F. W. B. TRIANGULAR WIRE? Give the Old Post Air to Make It Come Out Easily OST people who have had occa- sion to pull up old fence posts have undoubtedly been exasperated by the way they refuse, at times, to come out even when very loose. Very often this is caused by air pressure; the pole acts like a piston and the hole as the cylinder. As the pole NAIL BLOCK, TO POST LET AIR UNDER POST WITH PIPE By letting air into the vacuum beneath the post its extraction is made possible is lifted it exhausts the air and creates avacuum. Ona post 6in. in diameter the air pressure downward may reach 400 pounds, which readily shows why the post refuses to come out. If such a case is encountered, drive a small iron pipe under the post, as shown in the illustration, making sure that the hole in the pipe is free so that the air may enter readily. In almost every case the post will come out with- out further trouble.—VicTor H. Topp.

Page 71

nd le on aed -h LY re aS re \ ; Branch Houses in Principal Cities of WN United States, Mexico and Canada SS The Brunswick Method of Repro- duction gained instant and wide-spread public favor because it enriches the tone qualities of all records. For this alone it is adored by artists and approved by the hypercritical. It em- bodies the true principles of-tone re- production and complies with the established laws of acoustics in pro- jecting tone. Two revo- lutionary factors, among others essentially different from other phonographs, make this possible. They are the Ultona and the Tone Amplifier. The Ultona Plays All Records The Ultona—a product of creative genius—enables one to play all make records on the Brunswick. Nota combination contrivance nor complex mechanism, yet involving a fundamen- tal principle of sound. By a slight turn of the hand it Achieving the Ultimate in Phonograph Music By Means of Two Exclusive and Scientific Features supplies the proper needle, correct weight and precise diaphragm. TheAmplifier Enriches Tones As the name implies it amplifies tone, making it truer and sweeter. It is a vibrant tone chamber like the sounding board of a fine piano or violin. Con- structed entirely of mould- ed hollywood and free from metal it gives the requisite resiliency for unfolding and projecting true tone. Ask to Hear The Brunswick Any Brunswick dealer will: be glad to demonstrate the many claims made for it. Choose your favorite record to be tested—the one that will help you judge best. Your verdict like that of unnumbered thousands will be ‘‘the one super phonograph.” THE BRUNSWICK-BALKE-COLLENDER COMPANY General Offices : CHICAGO and NEW YORK Canadian Distributors : Musical Merchandise Y Sales Co., 819 Yonge Street, Toronto y / ¢ TTT } it | TERE =

Page 72

you I have eee $65 di sets, #nc Luding a |from this note size to the lowing extended type for HEADLINES serent type anguages, ol- I put the same Power of Empha- sts into the written word that oratory puts into the spoken wor "Just Turn the Knob" and emp asize. Two type sets always on each MACHINE. Iam the MARIOS Standard ‘‘Writing Machine”’ I work for Kings and Queens. I work for the President of the United States. I work for the Authors who play upon your heart strings at will. I work for the Clergymen who thrill you with their eloquence. I work for Big Business Executives—I help to extend trade to every quarter of the Globe. I am a machine, they say, yet I have an individuality that is strictly personal. I “speak’”’ every language from Eskimo igh to, Kata Kana Japanese. “speak” adgiepdly., aeaene I Bisralty make your writing talk— I have shown you a few proofs of my versatility in the various types above. You’ will agree that no other.typewriter can do what I do. Therefore, write to-, day for the story of all the wonders I perform. Just ask for this free pamphlet, “How President Wilson Frightened the Lords at Midnight’’ Address The Hammond Typewriter Co. 639 East 69th Street New York City - | USE HB BALL BEARING | | ELECTRIC MoTrors | ‘Better Power at Less Cost HB Bal'- Bear'ng Motors su bstanti jally save on operating costs, giving more economical, dependable, and better power than a gas engine. Trouble proof, absolutely re- liable. B:ilt for heavy service. Ideal for factory. gar- age, and machirie shop, and lower power bills. $20 Brings You Any HIB Bitar. Balance on Easy Term 1 to 15 hp. A Size to SUIT Your Needs Write our Service Department_your requirements. Get their Padvice-FREE ite what qumchinery you wish to run and the type of current available. We ~ 4, ie power system for. best Kenai E rd Swot cost. Attach Sy for fll nt head and mail to- ger fox for — informa. Ask also about Charges, Generators, etc, HOBART BROTHERS CO. Box S104 Troy, Ohio ful ufe ere Since 1893 The Submarine in War and Peace By SIMON LAKE, Submarine Inventor A thrilling story of the type of boat that changed the history of the world Price, $3.00 Postpaid Book Department Popular Science Monthly, 225 W. 39th St., New York Farm Sewage and Its Disposal By L. B. Robbins ROBABLY no sub- ject is so important in farm life and life in rural commun- ities generally, or so lightly regarded, as proper sanitation and disposal of sewage. Thousands of farmers allow the sewage from sink and closets to flow either directly upon the land adjoining the dwelling, or into a nearby stream, before removing the poisonous con- tents or making any attempt to reduce it to a negligible quantity. Then, perhaps, they wonder why a sudden typhoid epidemic runs a riot- Here’s a good way to keep down doctor bills and prevent sickness ous course through their family, pos- sibly carrying off some of their loved ones. The writer has visited scores of farms and watched sewage trickle from the house through soggy wooden troughs to a slimy, dirty pool somewhere in the garden patch and not too far from the well or pump. Such cases are not isolated; they areoccurring every day all about us with apparently no thought as to what the results may be. The usual precautions in disposing of such wastes are all right as far as they go but even with cisterns, deep sump holes and catch basins there always remains a certain amount of putrid matter at the bottom which it is dangerous to neglect. The drawing illustrates both the principle of construction, and a design, for a small septic tank for the ordinary farm. It presents a side sectional view from which the method of opera- tion will probably be readily under- stood. Sections A and B compose two parts of a concrete box about 8 ft. long by 3 ft. deep by 3 ft. wide. The partition D may be of concrete or wood. Wood can be easier removed if the tank needs cleaning, but of course is subject to rotting. . The sewer pipe C, from the house, should be turned down by an elbow and discharge about midway between the top and bottom of the tank to prevent disturbing the scum which floats on the top. Provide partition D with a series of holes, placed as shown, about on a level with the pipe C. This allows the passage of the contents from A to B with the minimum amount of disturb- 92 ' Popular Scvence Mo ‘hl ance. The horizontal baf. fle plate J further pro tects the scum from the action , currents. Tip up the discharge pipe E at an angle so the elbow stands at the same level as the contents of the tanks, Thus the action of the discharge water is kept below the surface level. Section F is an open concrete filled with stones. The floor sho be slanted slightly towards the oi end so the water will be carried out by the outlet pipe H. te In the center of the box erect a sheet iron baffle-plate G on a spindla: , This catches the water on its exit from the tank and spreads it to the air to aerate it. Run the discharge pipe H as tae from the tank as is necessary to distribute the water evenly over the land. Tiling, laid with open joints, will aid in the effective distribution of se fluid. Both sections of the tank should be provided with openings and tight- fitting covers for cleaning when neces- sary. Leave a small vent in each cover to carry off surplus gases in case of pressure during warm weather. YEG GALES 4 2) Zay) Showing in detail the construction of the tank and what takes place inside it The tank top can be constructed of either reinforced concrete, or of wood, as the builder chooses. If built of the latter see that it fits tight with no cracks through which dirt may fall and disturb the scum. Old Automobile Tires Aid in Moving Barrels PAIR of old automobile casings that were too worn to be of further use on the car were filled with rags, laced shut, and used im a ship- ping department to aid in moving heavy barrels of oil and other liquids. Two strap-irons were attached by cutting through the heel of the casings, one being fastened permanently to both tires and the other at only one end. The barrel was then set on end, one tire placed over it, and then turned over. The other tire was put on and the free end of the strap-iron hooked into the slit cut in the other tire. The barrel was then turned over on its side and easily moved. This not only made it easy to move the heaviest barrels, but they rolled in a straight line and made no noise. When the barrel was stored, it was set on end, the iron unhooked, the tires removed.—DALE VAN HORN.

Page 73

Farming Utah takes a lesson from agricultural Iowa ted of AID seasoned Iowa, as _ from veterans like you. Al- a Utah listened eagerly: ready we have irrigated near- th né “I’m a farmer through and ly 2,000,000 of our fruitful y fall through and mighty glad to acres. We raise fine crops meet another. You see I you must admit. Surely you Aid feel I’ve got a right to real have used beet sugar from Iowan pride. For Uncle Sam our great refineries.’’ ical has declared to me, ‘Iowa, 2 o @ irther among my 48 states you take Far-flung States always find with the blue ribbon for farms friendly get-together in Owls and ship- and farming wealth.’ Light White Owls. For these depend- oving up this friendly Owl.”’ able Cigars are high favorites all oe ? y over this good old U.S. A. De- a pendable fragrance is the reason. gee Utah puffed away and made Guaranteed dependable by the y thew reply: ‘‘lowa, we young farm- General Cigar Co., Inc., and their 7 parry ers are always glad to learn nearly $3,000,000 Owl leaf reserve. — DEALERS: ooked If your distributor does not sell these dependable cigars, write us. The gar Corr 119 West 40th Street, New York City s sid i TWO DEPENDABLE CIGARS move led in noise. OWL as set 3 for 20c white OWL 8c straight tires

Page 74

Look for the Daylo “Safety First’ medal de- sign tn the deal- er's window; he will have the right Daylo for you. Long Island City | “Daylo Would Have Prevented This!”’ | | —“if only you’d used a Daylo to hunt down that trouble | | under the hood, this wouldn’t have happened.” Of all the foolish uses of matches—and they are legion—none is quite so dangerous as around your automobile. AMERICAN EVER READY WORKS OF NATIONAL CARBON COMPANY In Canada:—Canadian National Carbon Co., Limited, Toronto On the road or in the garage, whenever light is required around the engine or inside the tonneau—when tires must be hanged, side curtains fixed, or a signpost read in the dark, Daylo is the absolutely safe “tf N even a gasoline leak with a Daylo “ou can safely hunt Stop taking risks with your car; get a Daylo now—you will want it with you wherever you go. Accept no sub- stitute; ask for the genuine Ever- Ready Daylo or the long-lived, brighter - burning Tungsten Bat- tery. New York 3661 Indoor Toilets (= Comfort Closet for Homes, a an Summer Cottages and Camps. WMA i Entirely odorless. Scientifieally ven- (lll ! —_ tilated. Strong chemicals dissolve 1 | contents; kills all germs. Easily in- stalled. Convenient to move. Con- tents disposed of easily as garbage. Prevents fly breeding and water con- tamination. Provides sanitary, odor- less teilet in home protected from cold and stormy weather. Only closet with porcelain container. Easily cleaned. Approved by U S. Health Bureau. 30 Days’ FreeTrial. Agents make$60to $100 weekly. Exclusiveterritory. Ask for booklet-—FREE. Comfort Chemical Closet Co., 1330 Factories Bldg., Toledo, 0. HERE’S YOUR CHANCE This 5 Passenger, 4 cylinder, 37 H, P. BUSH Car—Timken Beari: {Willard Batteries—2 Unit Starting & Leg.—116-inch whl. base. Write at once for the best Automobile Offer in existence—Don’t wait—Cars teed or money back. guaran! y BUSH sitswestatscy cessor. .Dsrtins HIGH SCHOOL PUPILS Earn $5.00 to $15.00 a week during after-schoolhours. Are you interested ? Then write to . Popular Science Monthly 225 West 39th Street, New York. Rest assured- | maT aT F Fault “The NIGH Twear of a Nation” for |uuxurious Lounging Night Shirts ess SINCE (881 a Exceeds Ex pectations ( nded by 'Pkekels) Re Tut Dealers BALTIMORE, NeW YORK ‘Popular Science Monthly S A Trousers-Hanger Used to Display Magazines LIVE newsdealer discovered g novel way to display interesting illustrations in a magazine, by which to attract customers by, suspending it from a post or other convenient point with the aid of askirt or trousers hanger, He simply clipped the two spring Skirt- and trousers-hangers can be used to good advantage in this manner jaws of the hanger to opposite sides of the periodical and hung it by a cord at a height at which those passing by could read.—L. B. ROBBINS. How Short Circuits Occur on an Automobile UTOMOBILE owners will do well to note the following and to do a little examining on their own account, if they are not getting the power from the engine that they should. Our machine which had been run- ning excellently, gradually began to lose power when the load was thrown on. It would run all right when standing in the garage, but when taken out on the road it lost power. A new carburetor was attached, which did no good. The spark plugs were tested and seemed to be in good order, and the spark was always in evidence. The machine was taken to a local garage and the mechanics did their best but all to no good. New cylinder rings were put on without success. Finally it was suggested that new wiring be run all through. This was done—albeit rather sceptically—and sure enough the engine promptly put forth its original power. The trouble was caused by the wires getting heated and becoming im- pregnated with oil until the insula- tion had become porous, thus the trouble did not appear until the car was on the road, when the jolting caused the imperfections to disclose themselves. The wiring had been tested several times, but did not show any signs of being faulty. The best plan is to carefully examine the insulation, and if it is the least bit soft put in new wiring. It is cheaper than new carburetors or piston rings.— ALBERT E. JONES.

Page 75

October, 1919 Why does every Barber use this type of Razor? id ; ‘ ; me ¢ Because while you might shave your own self-with a ing by razor that pulls and scrapes, you won’t stand fora barber } shaving you with a dull razor. A barber has to have a razor so sharp that it will shave ae: you without pulling. He must use a blade whose keen edge can be restored again and again with a few easy ll do strokes on the strop. vd = Anybody Can Strop a GENCO Razor ng the Every GENCO blade is ground concave; its back is broad; and ; they _ its edge is supported by the required bevel. These features compel oe a GENCO blade to meet the strop at the right angle to restore nm run- q the best of shaving edges with a few easy strokes. cot \ And that edge on a professional blade—how quickly and smoothly wha a it doesitswork! It’s the edge that every barber finds he must have. 1 taken The Safege is a regular razor witha guard. Flip back the guard, A new | and its blade can be stropped sharp as easily as the other. ch did You undoubtedly have seen many Genco Razor advertisements. 7 bene Why not go to your dealer and see the razor? If you cannot | order, conveniently secure Genco Razors in your locality, we will see that “er you are supplied. d their Remember our guarantee, ‘“‘Genco Razors must make good or ylinder we will. “ye Geneva Cutlery Corporation his was 47 Gates Avenue Geneva, N. Y. ip Largest Exclusive Manufacturers of High-Grade Razors in the World y pu 1e wires ng im- insula- us the the car jolting disclose 1 been ot show ; ag ever stropped a Stade ale eee Mt It ial backbone to the edge? This Blade can Ra SS ee just the correct angle to assure a perfect . ving edge. S°

Page 76

wr me our Pencil ? "jae “Neither lender nor borrower be’’, —hold fast to your ELDORADO. But have you found your DIXON'S ELDoraDO the master drawing pencil! —the pencil. that makes your fingers feel fit and puts a pleasant pep in your pencil work? Our. pencilogue “Finding your Pencil” tells you how. to find it: a free copy to every- one who wants to ease and quicken his pencil work. Write for it to- day. And if you wish sampies worth double the money, enclose I5c, stating the work you do. ~ feseph Dison brucible 5 Pencil Dept: 120J Jersey City. NJ AR. Mec Dougall & Co.,Ltd. Toronto Pred There’s a Dixon-quality Pencil, rayon and Eraser for every purpose. [HB BATTERY CHARGING GET BIG PROFITS THIS FALL $100 to $200 CLEAR EVERY MONTH Fall b big demand for reliable HB Battery service. Get our HB500 watt Charger NOW, Recharges 1 to 8 6-volt atteries. Cost 10c to 1bc each, customer pays 75c to $1.50. No repairs, no burn outs or expensive ene nte_ Gener. reli- able service. Easy to install and operate. no mechanical | e requir Small Cash Payment Puts This Money-Maker in Your Shop Balance on easy monthly terms. Profits easily carry payments. Absolute Money- Back G Start you. IDAY for in- HOBART BROTHERS COMPANY Box $101 Troy, Ohio ul Manuf since 1893 Send for a Complete Catalogue of MASONIC BOOKS Jewelry and Goods REDDING & CO. Publishers and Manufacturers 200 Fifth Avenue Dept.S New York Uses for Empty Carbide Cans hosted carbide cans By David Baxter may be employed for quite a number of different things that are convenient to have about the garage or shop. The garage or repair shop possessing an oxyacety- lene welding plant will find the empty cans especially useful. They are well made and air-tight, and of strong material. They may be made into a conve- nient moisture-proof, dust-proof cup- board for storing material and sup- plies which require to be kept dry and clean, such as chemicals, gasket ma- Popular Science Moy h Another use for emp carbide cans is to convert them into tool-boxes or containers for the storing of nails, sere washers, wrenches, small tools, ete Two styles are shown in the accom. panying drawings, and others May be made to suit the individual ideas, One is made by cutting the can jp half along each side, keeping the endg intact. To these handles are fastened, Wooden legs are nailed to the bottoms or metal legs are easily made if preferred. This is a handy devic9g for such tools as wrenches, hammers, terial, bolts, welder’s metal, flux chisels, and other tools in constant uge, powders, The other and so on. style ig The air- for tongs, tight lid scrapers, of the can clamps, pok- effectually ers, etc. It prevents is made by any mois- cutting sey- ture or dirt eral differ- from enter- ent sized ing its inte- holes in the rior. end of a can The can to receive lids may be the handles fastened to of the differ- a part of the LABELED CANS ent tools, rack with a IN RACK ve This ar- chain or rangement wire. Thisis keeps the not neces- tools always sary, how- U in sight, so ever, if the These are only some of the uses for old that they mechanic carbide cans. What can you do with them? may be se- makes it a lected in- rule to keep the can closed at all times. The lids should have labels pasted on them stating the kind, quantity, or other information concerning the con- tents of each can. This saves a deal of time, as the desired information can be had at a glance, and it prevents trouble due to selecting wrong ma- terials. The accompanying sketch will assist in the construction of a carbide can cupboard. No measurements or spec- ifications are given here as‘ this is a matter of individual choice. The style and size of the cupboard may be varied to suit conditions. The cans may be placed in one, two, or more tiers of any desired number. The drawing shows one tier, six cans high, which is very convenient. It occupies small floor space, and will fit behind a door or in an odd corner. Any rough lumber may be employed to construct the frame-work, with braces and cross pieces, upon which the cans rest. There should be cross pieces in front and behind the cans tu keep them rigid. A rough but sub- stantial rack can be made in an hour or so of spare time. Of course if the maker is more particular ke may use better lumber and give the whole thing a coat of paint, or he may make it fire-proof by using metal angle bars welded together. 96 stantly. An iron bail is fastened to the container so that it may be carried about from place to place as needed. One each of these tool-boxes gets rid of two empty carbide cans. Still another way to make use of empty carbide cans is to employ them for shipping delicate repairs. A car- bide can weighs little, if any, more than a strong wooden box or crate, so that the freight cost isthe same. The many advantages of a can over a common crate should recommend its use in preference. It is moisture- proof and may stand on a country depot platform in the rain without harm to the contents. Its construc- tion prevents it from being smashed in the usual handling of freight or express. The size and shape make it a con- venient package to handle and store. The nature of the lid dispenses with all nails, wire, etc., making packing an easier and shorter process. Small articles, such as small web gearing, carburetors, manifolds and other fragile parts of automobiles can be — shipped in safety. The carbide can is — filled with excelsior or straw, the article — being bedded in the packing material. Jugs or bottles of oil and other liquids ~ can be shipped in these containers when the haul is short. The foregoing are only a few of the many uses for empty carbide cans.

Page 77

; empty Convert Ntainers scre October, 1919 ols, ete. / accom. Blue Buckle OverAlls ie “Strong-for-work” the ends battens LL the joyous satisfaction of ‘‘doing-a-job” in comfort is yours when — S. you’re togged up in big, generously oversize Blue Buckle OverAlls. a . ; .mmen, They’re made to meet every wish any man can make for a perfect vote work-rig! They’re right in quality of denim, fit and workmanship! le They give long, true service under the most exacting conditions tongs, aa rae | When you get into Blue Buckle OverAlls ete. It or a Blue Buckle Coat, you know you've ae al struck the best workgarment made in V- differ- America! And, they fit so comfortably! sixee Inspect the reinforced backband, the un- of ; = breakable seams, the non-ripping fly, the real eceive fF brass buttons and clasps, the careful making, handles e differ- the raglan sleeves! Your money never tools, bought you greater value! S ar- ement TRADE MARK 9s the always ght, so , they be se- i He ee - Jobbers OverAll Co., Inc. carried Lynchburg, Va. needed. rets rid Reg.U.5.Pet.Ore Largest manufacturers of Union Made Overalls in the world use of \v them A car- y, more rate, so 2. The over a end its oisture- country without nstruc- shed in 2x press. a con- 1 store. es with king an ll web is and 3 can be > canis — article © aterial. — liquids — tainers |

Page 78

Motorcycles, Side Cars and Cyclecars— Their Construction, Management and Repair By Victor W. Page. Describes fully all leading types of ma- chines, their design, construction, maintenance, operation and repair. 550 pages 350 specially made illustrations, 5 folding plates. New edition. PRICE, $2.00 POPULAR SCIENCE MONTHLY 225 West 39th Street New York City WDC PIPES are ex- pertly fashioned and fitted by the master handsofcon- tented and self- governed workmen. All are eager to uphold the standard of quality for which the WDC Triangle stands. Each pipe is genuine French briar, guaranteed against cracking or burning through. Sold at all good dealers at popular prices. Wa, DEMUTH & CO.. New vorK WORLD'S LARGEST MAKERS OF FImMEe OIPES Location of Motorcycle Troubles Made Easy This chart simplifies location of all power plant troubles and will prove of value to all who have to do with the operation, repair or sale of motorcycles. No details omitted. Size 30x 20 inches. - PRICE, 25 CENTS POPULAR SCIENCE MONTHLY : 225 West 39th Street New York City Vanderpool Vulcanizer (5 Cavity) has capacity of $100 worth of work a day. We are the pioneers in the man- ufacture of the Dry Cure Vulcanizer—the only vul- canizer that guarantees absolutely PERFECT work. Open a Tire Repairing Shop. Business pours in. No experience necessary. We give you free instruction. Write for FREE TIRE REPAIRING MANUAL and full particulars. Write today. you be. If others can be successful, so can In answering address Dept, U-15 WM. VANDERPOOL CO., Springfield, O. Popular Science Mon Never Breathe the Exhaust Gases of an Automobile HEN Nat Wills, the noted actor, was found lying beneath his car, dead, and it was found that hig death had resulted from inhaling theex. haust gases of an automobile, the motor. ing public be- gan to take precautions against this menace. If oneshould remain for five minutes in a small unventilated garage, with the door shut and fumes pouring from the car’s exhaust he would be beyond the doctor’s aid. If you must work on the car with the engine running attach a hose to the exhaust and run the hose into a pipe that communicates with the outer air, In this way you get rid of those deadly fumes and eliminate the danger of being suffocated by them. It is very simple to arrange so that this can be done. A hole is made in the wall of the garage, in a con- venient position to the rear of the car, and piece of gas-pipe inserted. This should be of sufficient length to protrude about 6 or 8 in. on each side of the wall and, if the wall is wood, duly insulated, Connection is made with a hose.—E. T. OFELDT. EXHAUST PIPE The hose carries the deadly fumes to the outside air and keeps the garage air pure Improving the Handsaw with Additional Teeth DEVICE much used by our local carpenters, instead of carrying 4 special nail saw to negotiate nails en- countered in repair work, consists of forming what may be termed an emergency hacksaw, by cutting, on the back of their regular saw, for a space of six inches or more, commencing at the point, a series of fine teeth, about sixteen to the inch, as shown in the sketch. These are better cut with straight faces, and square across, like a minia- ture ripsaw tooth, as they bite into the metal better, and wear longer before needing refiling. When you encounter a nail, or even a piece of gas-pipe, instead of quitting work and hunting for a nail-saw, just turn your wood-saw over and cut it through with the fine teeth on the M uf “0, ty 4 Va r yt ee Teeth on the top end of the handsaw do away with an additional nail saw back. As soon as the nail is van- quished, just reverse the saw again to its normal position and continue the work.—CHARLES A. PEASE.

Page 79

[x arcTic CIRCLE NY The bridge of a U.S. Army Transport after heavy weather in the Sea of Japan. PE he d de air and air Pure beyond with the ' to the » & pipe ter air, of being of bein ; ; Around the World with Kenneth L. Roberts The occupants of Ceéch and Amertcan troop tratns 50 that a ta : é . : exchange amenities. 3 made AGAZINE readers are familiar with Captain Roberts a can splendid work and will be interested to know he is a of the staunch Coronatypist. Here are some of the things he says iserted about Corona: ngth to *... | bought a Corona and dropped it into my kit bag and ch side went where I was going. That... wasa year and a half ago - wood, ... 1 hammered it and hammered it and hammered it, but 3 made not once did it weaken under the strain. I dropped it into my kit bag and went back home... When I was ordered to Siberia with the Military Intelligence Section of our Expe- san ditionary Force, I packed my Corona in my bag and took it along. I hammered it day after day on the train. I hammer- th ed it day after day on the transport crossing the Pacific. It stood up nobly under the rigors of the Siberian winter... Czech soldters watting to entrain at the Vladivostok Station, Tr local It went to Japan with me, to the Philippines, to Guam, to Ay a Hawaii and back home again—busy every day. In the year rie and a half I have had it I have written well over SIX HUN- “y of DRED THOUSAND WORDS on it—Intelligence reports, . Pre correspondence, diary, verse, fiction and magazinearticles...” n the = Ls . ° ace of No one else gives the writing machine the hard usage it gets at the hands of , 0 writers and correspondents. Captain Roberts’ experience is typical. Corona at the does stand the racket. about Corona is something besides a mere writing machine, because of its compact- in the ness, lightness and portability. Pick it up with one hand, tuck it under your arm and go off by yourself with it—in chamber, den or study, where you raight won’t be disturbed. Or, fold it up and put it in its handy case; take it to = China or Cuba or Buenos Ayres or the North Pole. It typewrites anywhere. minia- marching down ihe mats to the Price Fifty Dollars, with Handy Carrying Case creat of Vladteostok. before Ask our local Agent to show you Corona, or send to us for booklet CORONA TYPEWRITER COMPANY, INC. - even GROTON, NEW YORK oe Branches or Agencies in Principal Cities all over the World itting ’, Just cut it 1 the Corona weighs but a ‘ trifle more than 6 pounds; folds up snugly when not busy; travels where you travel, serves you on the 7 instant. Ruggedly built, simple to operate, always handy, néver obtrusive. The Personal Writing Mach ine -fold it up-take it with you-typewrite anywhere $50, with carrying case. aw aw van- in to

Page 80

[<= w&

Herman * Style 44 * Munson Last Tan Russia Calfskin w& ® & te | Send for Catalogue w Sd T wasn’t so much the wear of their Army shoes that # made the conspicuous success | of the American soldiers’ foot-

wear in Europe. It was their natural fit and their incom-

parable comfort. * w | The Herman Shoe Company made hundreds of thousands % of pairs of those Army shoes. x | We make millions of pairs of w

civilian styles on the same Munson U. S. Army lasts.

These shapely civilianized : | military shoes—built of the | best leathers obtainable and % with the best of New England * everywhere as automatically perfect. | workmanship—are recognized | % w% correctly and quickly through our MAIL ORDER D&P*T at Boston JOS. M. HERMAN SHOE CO. 802 Albany Building BOSTON, MASS. eg 25 Cords a Day Easily Sawed By One Man. Easy tomove from cut tocut. Make big profits cutting wood. Cheap and easy to operate. OTTAWA [OG SAW Does 10 men’s work at one-tenth the cost. ee work easy. = regen oat used afer running pumps an er '. iw biade easily removed. Write for our low price. 10-Year Guarantee. Sold in 8,000 retail stores. If you | are not near one, we will fit you | % bg

Put Disc Wheels on Your Ford Build them yourself, it’s very easy with the Kuempel Disc wheel pat- _ terns-and instructions. Life sized paper patterns, with instructions sent postpaid for 50 cents. Dept..J K Ford KUEMPEL CO. equipped with Kuempel Discs ‘ GUTTENBERG, IOWA ELECTRICITY MADE SIMPLE A book devoid of technicalities.’ Simple, plain and understandable. $1.00 Postpaid. Popular Science Monthly, 225 W. 39th St., New York

. rods, giving four projecting ends.

How to Make a Cheap, Heavy Flywheel NE of the most troublesome items in the building of an amateur lathe, or any other foot-power ma- chine, is the flywheel. A good heavy wheel is needed; a light wheel often spoils an otherwise good job, while a heavy one gives a steady, powerful motion that is conducive to good work. A cast-iron flywheel is very expensive, but practically as good a wheel can be made of concrete. When finished it looks for all the world like a grind- stone. All that is necessary is to pour con- crete into a mold of the proper size and

CONCRETE fReeqSTEEL PIPE Gaee BLARING Making this cheap, cement flywheel saves buying the manufactured article shape and let it set hard. The mold can be made in a variety of ways, de- pending upon the size of the wheel. A round cheese-box answers for one size very well. Care must be taken, how- ever, to be sure that it is round, for it is likely to be somewhat out of true. Mount it on a board base, or on the floor, and nail down blocks to press against the bulges and push them in; the low places will them come out of themselves. It is worth while to do this very carefully. It is best to cast the wheel directly on its shaft, if this is practicable. Take the greatest pains to get the shaft exactly in the center, and exactly perpendicular to the bottom of the molds, otherwise the wheel will wobble and be a regular nuisance. Steel pipe, sold by pipe-fitters, is as good as any- thing for a shaft that does not run in machined bearings. Drill a number of holes in the pipe, where it will be covered by the concrete, and drive pieces of iron or steel rod into the holes, letting them project four or five inches, or even more, on each side. Have them sticking out in all direc- tions, porcupine-fashion. This makes the wheel and shaft absolutely solid and secure. For a wheel of moderate size, say up to 18 or 20 inches in diameter, it is sufficient to use two For a wheel of this size use wire about 3/16-in. in diameter; don’t make the holes so large or so numerous as to weaken the shaft. In mixing your concrete use about one part of Portland cement to four or five parts of clean sand, and make it about as thick as the mortar the brick- layers use—or perhaps just a little thinner so that it will run and settle well into place. 100

Popular Science M. onthly Exceedingly satisfactory beari,, can be made for a steel pipe .naft of hard wood. Make the bearings in halves, split at the center line of the shaft, and fit them carefully so that when they are screwed or bolted to their beds they will hold the shaft closely without’ binding. Use no oj] Use dry graphite for lubricant. , A good way to get a fit and a good surface is to make the bearings so that they will grip the shaft tightly. Pyt in lots of dry graphite, screw the bearings down tight and turn the shaft. The wood will be somewhat compressed, and the high spots will be smoothed down. The longer the wear. ing process is continued the better, Then loosen up the bolts or screws, and put thin cardboard washers between the bearing halves until the fit is just right. This way of making flywheel, shaft and bearings was tried in the con- struction of a good-sized amateur foot lathe. The wood bearings are so easy- running that the wheel will rock in them just as a bicycle wheel rocks on its ball bearings, and after nearly two years’ use there is not enough wear in evidence to permit the thin card liners to be taken out. The bearing sur- faces are black, hard and as smooth as glass.—HOWARD GREENE.

A Small Punch Fitted with Renewable Ends N small assembly work, such as typewriters, computing machines, small arms, etc., there is much work that calls for punches of a rather delicate nature. The one shown in the illustration is a fair sample. It is re- quired to reach through a 7/64- in. hole, 11/16 in. in length. To forge such punch- es is a slow and expensive job. To turn them out of stock is quicker but the punches are not so good. Either way the upkeep cost is high. One factory has entirely dis- carded the solid punch for the kind shown, which speaks for itself, The bodies . are made from a low carbon steel, about forty per cent, drilled and set- screwed for the renewable ends, which are cut off by the hundred from standard drill rod. The ends can easily be given the exact temper best suited for the work and they are less apt to break than solid punches and if they do they are replaced in an instant. Their produc- tion cost is a trifle—D. A. HAMPSON.

TEMPERED DRILL ROD

Renewable ends in this punch, when broken, are very easily replaced

Page 81

f onth; bari, g naft of ngs in Of the 30 that lted to > shaft no oil, 4@ good SO that . Pat w the rn the newhat will be e Wear- better, V8, and etween is just ' shaft e con- ur foot 0 easy- ock in cks on rly two vear in 1 liners ng sur- smooth with ch as chines, n work rather 1 in the t is re- MACH. STEEL -MPERED ILL ROD 3 in this broken, -eplaced _ steel, id set- which . from en the e work k than 1ey are yroduc- MPSON. cAnnouncement For over a decade Ford owners have wanted closed-car luxury without the large first cost that goes with it. They have wanted a Ford Top that could instantly be con- verted into a closed or open car without the disagreeable work of fastening and unfastening curtains. For the first time a practical, convenient method of assuring closed-car luxury with either a Ford Touring Car or Roadster has been developed. The UsTus Limousette is tailored to fit the Ford Car perfectly and due to its unique design there are absolutely no alterations to be made in the body or top of your car. 2 A roller window at each door, of sturdy and permanent con- struction, rolls up out of sight in the top at a light touch. This enables the car to be instantly converted from a cozy closed car in winter to an open car for the breezes of summer. Also it enables you to keep out the dust and rain. Clear vision, both front and sides, is another convenience. The Ustus Limousette weighs only 40 pounds and can be installed in an hour. The price is $46.00 for Touring Car and $30.00 for Roadster. Ask the Ustus Dealer in your town to demonstrate its advantages. If there is not a Ustus Dealer in your locality write us directly. DAFOE-EUSTICE CO., Manufacturers 1194 W. Jefferson Ave. Detroit, Mich. Distributors Frank Jennings Waller Implement Co. Springfield Commercial Springfield, Illinois San Antonio, Texas é y Co. Dayton Keith Tri-State Accessories Corp. Springfield, Mass. Bloomington, Illinois El Paso, Texas McAfee Specialty Co. Geo. W. Copp Co. Morriss Brothers we... ae Place 236 W. 54th Street Dallas, Texas inneapolis, Minn. New York City, N. Y. Northern Electric Co. Walsh Motor Car Co. _Crow-Burlingame Montreal, Quebec Pg Poorsag a Little Rock, Arkansas Ohio Auto Equipment Co. Os 2 h Hammond-Elliott Co. Marion Bldg. 1418 wre oo ~~ 23 Peachtree Arcade Cleveland, Ohio N pow me ~~. t. . Atlanta, Georgia Rue Motor Co. een ee Harrison Distributing Co. 2443 S. Michigan Ave. Psa a> & a, Fargo, N. Dakota Chicago, Illinois ‘Wseinan Wedinn Geass. Beith Yen Tom Milejghn 1162 Penobscot . ilson g- 4 Detroit, Michigan Dallas, Texas Fond-du-lac, Wis. Herring Motor Co. Indiana Tractor Co. Des Moines, Iowa Indianapolis, Indiana Hubb Diggs Company Backus Motor Co. Fort Worth, Texas Baltimore, Md. Ustus Protective Covers The Dafoe-Eustice Company also makes guaranteed protect- ive covers for protecting farm implements, hay stacks and hay cocks. Write today for free catalog and prices. Me 7\

Page 82

LEYS —_— eer of pROC E Sse

20th Century Book of Recipes, Formulas and Processes Tuts book of 800 pages is the most complete Book of Recipes ever pub- lished, giving thousands of recipes for the manufacture of valuable arti- cles for every-day use. Hints, Helps, Practical Ideas and Secret Processes are revealed.within its pages.- It covers every branch of the useful arts and tells thousands of ways of making money and is just the book to have at your command. 10,000 Practical Formulas—The Best Way to Make Everything The pages are filled with matters of intense interest and immeasurable practical value to the Photographer, the Perfumer, the Painter, the Manu- facturer of Glues,-.Pastes, Cements and Mucilages, the Physician, the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, the Potter, the Tanner, the Confectioner, the Chiropodist, the Manufacturer of Chemical Novel- ties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, the Engraver. the Provisioner, the Glass Worker, the Goldbeater, the Watch- maker and Jeweler, the Ink Manu- facturer, the Optician, the Farmer, the Dairyman, the Paper Maker, the Metal Worker, the Soap Maker, the Veterinary Surgeon and the Tech- nologist in general. A Mine of Information A book to which you may turn with confi- dence that you will find what you are looking for. A mine of information, up-to-date in every respect. Contains an immense number of formulas that every one ought to have that are not found in any other work. One useful recipe will be worth more than ten times the price of the book. Price $3.00 POPULAR SCIENCE MONTHLY 225 West 39th St., New York

Pipe Brackets to Support Bottom Boards of Wagon RDINARILY, in dumping the load from a wagon, the bottom boards must be lifted over the high sides and placed on the axles. This is inconvenient and can be obviated if two brackets, as illustra- ted, are made for support- ing the boards. For each bracket use three pieces of pipe, about 1 in. in di- ameter, screwed into two, 90-deg. elbows. In this way a convenient : ledge is formed (suum on which to place ¢ the boards. —E. | W. BUERSTATTE. Wagon sides fitted in the fashion shown will permit doubling the load

Zin V2 30DaysFree Trial bieete ynesiost. actual riding test, PAYMENTS if desired,at \ asmalladvance overour Special *% Factory-to-Rider cash prices, ® Do not buy until you get our ma great new trial K er and low ines gad tet term: HORNS =S pedals paineeheds : 7 uae Leesa rasta ri oO tare SEND NO, MONEY bat write

gore mane NY ME (eed AGENTS 229°: Gold and Silver Sign Letters For store fronts, office windowa and glass signs of allkinds. No experience necessary. Any. one can put them on and make money right from the start. $30.00 to $100.00 a Week! You can eell to nearby trade or travel all over the country. There is a big demand for win- dow lettering inevery town. Send for Free Samples and full particulars. Liberal Offer to General Agents, METALLIC LETTER CO., 433A N. Clark St.. Chicago

Jewel Elgin, Waltham, Howard, or any watch you want, send for Jj 112 Pages Wonderful Values bf Diamonds, watches rings, jewelry, up-to-date designs. Buy the Ware Way, = pe miss the mone erty nds accepted. - ALFRED WARE CO., Dept. 955 j Let us prove it. St. Louis, Mo. HANDBOOK FOR FREE AIRPLANE MECHANICS Here is a book prepared specifically for the man who wants to knowthe Airplane, from rigging and adjusting the planes to the erection, care, and repair of the motor. If you would know the mechanics of the Airplane, get a copy of Colvin—Aircraft Mechanics Handbook $3.00 Postpaid FREE TO YOU. If you will send us five yearly sub- scriptions at $2.00 each, we will send you this book free. POPULAR SCIENCE MONTHLY, 225 W. 39th St., New York City

Golden Cen ue PORTABLE It Adding Machine | Machine’ a7 fgonoeed (\ a Over 100,000 in Use Mostly sold through recommendation For Personal Desk or General Office _ It checks mentalcalculations, | Buy through your stationer. [i Writefor 10-day TrialOffer | P. E. Gancher, A. A. M. Co. 148 Duane St., New York Canadian Agency

Boys, Build This Car. This nifty little car driven by gasoline motor, can be bi ilt by y boy. Parts are furnished “by us and are very c Send 26c for 35 Miles

per hour é Geode (eerste a baie Is Record ig of this . SYPHER MFG. CO. 4 Car 174 Warren St. os TOLEDO, OHIO

Page 83

Sbee 8,8 se¥Fuasa sebela 22 2if 1} Week! ravel all over nand for win- end for Free Agents, st. Chicago 19-21 , Howard, t, send for e man who 1 adjusting the motor. > Airplane, indbook rearly sub- 3 book free. lew York City ve list of parts this lad’s car, . TRACTOR TYPE ie = “AC Tractor” Porce- oS -ee Assem- bly. The porcelain is welded right in the bushing, insuring a gas-tight union at all times. Note the sharp edges of the porcelain. These knife edges at- tain great heat which burns off carbon as fast as it forms. This is the famous AC Car- bon Proof construc- tion Copper-asbestos Gasket This is seated in the shell at the base ot the bushing, is an added precaution against gas leakage. = ‘AC Tractor” Shell This shell and the por- celain are ground con- centric. Therefore the m‘ddle electrode al- ways comes directly in the center when the plug is assembled.The porcelain-bushing as- sembly is screwedinto this shell. No matter how tightly the fit is made, the strain al- ways comes on the metal, never on the - porcelain. The Standard Spark Plug of the World It Solves the Three Big Tractor Problems The new, two-piece AC Tractor Plug is ready. | It incorporates two exclusive AC features which rec- ommend it for general tractor use and particularly for engines that burn kerosene. Tractor users everywhere will appreciate the advan- tages of these features which overcome the three common disadvantages. 1—Because tractorsare frequent- ly left exposed to the weather or because kerosene is used in the engines, spark plugs tend to foul quickly. The AC Tractor Plug will not foul readily because it has the famous AC Carbon Proof Porce- lain with the knife edges that attain terrific heat which burns off carben as it is formed. 2—After the average plugistaken apart for cleaning there is danger lest a gas-tight joint may not be secured in reassembling. A leaky joint means a quickly ruined porcelain. The AC Tractor Plug with its welded porcelain assembly is always gas-tight. Furthermore the bushing is ground concentric with the lower shell so that the middle clectrode always comes exactly in the center of the shell. 3—In the two-piece type of trac- tor plug where tightening strain is directed to the porcelain itself, cracking or breakage may result. The “AC Tractor’’ design puts all tightening stress on metal parts where it belongs. No strain whatever is transmitted to the porcelain. This AC Tractor Plug is no ex- periment. It has been thoroughly tested and proved in every type of gasoline and kerosene burn- ing engine. Your dealer can supply you with these plugs now. Equip your tractor with them and see how they put an end to your spark plug troubles. Champion Ignition Company, FLINT, -ichigan 13 U.S. Pat. No. 1,135,727, April 13, 1915, U. S. Pat. No. 1,216,139, Feb. 13, 1917, Other Patents Pendine

Page 84

MPARE the cost | of Florsheims with | the superior value they | give and you will find | they are more econom- ical than ordinary shoes. | Consider the wear, not the price per pair. |) Look forthe quality ha = «mark “Florsheim.” The Florsheim Shoe Company CHICAGO, U. S. A. WH Write for booklet “Styles of the Times” The Rainbew— bring highest zs Start right, get Rog- prices ever known ets Improved Trap- nit pers Guide—Free— | baad the best ever out. prices. grades fair- fsappers supplies, Send fo; est —no dickering. } pays eash and ship- ping charges on furs bignest money for ¥ "Address Dept. 1002 FUR CO. ST.LOUIS ALL OR SPARE 200 con make $35.00 TimE $100.00 a week. ¢ want hustlers. money-makers, to work with me, to advertise, sell and appoint agents. Big- i i i ’ gest thing in years. City oo a oe convenloness without ie ~» plumbing s m any room. ad | . x... ished sight. Demonstrating AO basin $ small, self-empty- “"AGENTS MAKE SALES EASILY +i Two sales daily means $60.00a week. . Leggett. Ohio, ‘Worked two hours, took two orders, profit $i0 00."" Hayhurst, Nebr., **Took 11 orders in 4% days—profit $55.00, ordered 12 more tubs.’” Manning, Iowa, ‘‘Sold 10 tubs in one day—profit .00.°* Nebr., ‘‘Sold 12 tubs in three ———— 00," And hun 2 of “others making big money. 70 percentof have Experience and new aon unnecessary. Credit given to the right man. ‘Get fon “special plan;’’ ell Fars, A. $. B. $. Robinson, Pres.. Pres., une ROBINSON CABMET rs. fo. $10.00 FOR YOU. How would you like to suld you like to make $10. 00a week duri week during your spare time? Others are doing it by representing PoPULAR ScrgNcE MONTHLY. Why not you? POPULAR SCIENCE MONTHLY, 225 West 39th Street, N. Y.C. A High-Grade Varnish from an Old Automobile Tire HE old tire is first cut up into very small pieces with a pair of shears. This is accomplished very easily if both the tire and the shears are kept wet. The rubber scraps, which weigh about ten pounds, are A pm \g | | vs TL | soa i Another use for old tires. a fine varnish for hardwood floors They make | then put in an iron pot (an old wash boiler will do) and covered ‘with water, _ to which two pounds of caustic soda _ is added. The pot is put over a fire and thor- | oughly boiled for two or three hours, | after which the rubber scraps, now de- vulcanized, are washed and spread out to dry. Ten one-gallon preserve jars are next obtained and into each is put about one pound of the dry rubber scrap. The jars are then filled with benzole (not benzine) and left for about ten days, or until the pure rubber is dissolved in the benzole, leaving a sediment of zinc oxide and other fillers, which are used in the manufacture of automobile tires. If the jars are shaken occasionally the rubber goes into solution much quicker. The rubber solution, Which is about six per cent rubber, is de- canted into clean jars and is ready to use in making the finest flexible and waterproof varnish at a cost of less than thirty cents per gallon. The following formula gives the pro- portion for one gallon: Dissolve two pounds rosin in a quart of benzole; then add four ounces ben- zine and one-half gallon rubber solu- tion. A varnish with a much harder sur- face can be made by using manganese resinate, or, in fact, any metal resinate in place of the rosin. It is well known that rosin varnishes have a luster far superior to any other gum varnishes, with the exception of sandarac, but the rosin always cracks. The mixture of rubber and rosin will always be flexible and still retain its luster. The small quantity o* benzine is 104 Popular Science Mg added to make the varnish flow freely; without it the varnish gets strings under the brush. Following are some of the succesgfy] uses found for the varnish made as described above: Varnishing hardwood floors; ag g metal-protecting coating for brassb and bright metal work on automo. biles; as a bronzing liquid—it dogg not attack either aluminum or bronze powders, so makes an excellent ye. hicle for them; used in place of shellac on armatures and insulation work; as an automobile body and shed paint—dissolve one-fourth pound of oil black aniline in a gallon of the varnish; as a waterproof roof paint— mix four pounds dry red lead with a gallon of varnish, give the roof one coat of this paint and a second coat of the plain rubber solution; as a house paint—mix four pounds of any color pigment with a gallon of the var. nish.— JOHN E. CLEGG. To Remove Nails Without Damaging Fine Wood ANDALS are, unfortunately, like the poor—they are always with Antique furniture is by no means us. The top of the nail is drilled off, then wax | is inserted in the hole to camouflage it exempt from their depredations. Con- sequently, at times one finds fine old Sheraton, or Chippendale, or other pieces, with nails or tacks ruthlessly hammered into their legs, panels, etc. Truly a sight to make angels weep. Here is a way to get rid of such nails: First, consider well the nail. Note its size, as judged from the head. Ifa bit of the shank shows, it will be easy. The length of the nail does not matter; what you want is the size and diameter of theshank. Having ascertained that, select a metal drill that will be a size over the diameter of the nail’s shank. With a center punch, make a seat for the drill exactly in the center of the nail’s head. Drill carefully into the head of the nail, until you cut through the head into the shank, and the head will come off in the form of a small button. A drop of hot wax will close up the tiny hole and will pass for a small wood knot when the article is refinished.

Page 85

automo- -it does * bronze ent ve. lace of sulation nd shed ound of of the paint— | with a oof one Coat of a house Ly color he var. ‘hhout od aly, like ys with ) Means lage it . Con- ine old - other thlessly Is, ete. 2ep. h nails: Note l Ifa e easy. matter; ameter .d that, 2 a size shank. eat for of the ito the hrough ie head a small ll close s fora ticle is mm Sa a 5 A Does Present Day Gasoline Give Your Car Indigestion? HE superior gasoline of a few years back and the gasoline we must use today, are two very dif- ferent products. The “gas” of to- day is too heavy. It will only partially vaporize. But theenginesarestill built to consume the fuel of a few years ago. The low-grade fuel-blend of today must be reckoned with. Undigested food clogs your system. Can you swallow your food in lumps? Neither can your car. Why does the gasoline in your car to- day give your engine indigestion? Be- cause the fluid is partly pure gasoline and the rest a kerosene-like liquid that forms into drops, instead of vapor-fog. These drops soon make their way into the cyl- inders and the crankcase, cutting the lubricant and causing friction. The poorer the gasoline has become, the steeper have been the repair bills. As the gasoline becomes more and more like kerosene with each year, your repair bills increase. It is impossible to change the fuel—to go back to the gasoline that automobile en- gines were designed toburn. There is not enough of that kind of gaso- line to go around. Hence, the engine must be changed. The Chalmers engineers have worked over this problem for two years, making exhaustive tests and experiments. ‘The power was in the gasoline, but the old style engine could not get the power out. The Chalmers HOT-SPOT manifold with the Ram’s-Horn shape has wonder- fully solved the problem. There’s no waiting for the engine to warm-up in the new HOT-SPOT Chalmers. She starts easily and promptly even on the coldest mornings. Why?—As soon as a drop of fuel strikes the Hot-Spot, it is vaporized at once. It can’t work down into the crankcase and do irreparable damage; it is used to drive the car. Then the Chalmers engineers designed the famous Ram’s-Hornshape of manifold, The Ram’s-Horn, because, it is free from carbon, makes it’ easy for the vapor to enter all cylinders uniformly. Ordinarily the sixth cylinder gets either very little gasoline or just the raw, unvaporized drops. The Ram’s-Horn manifold sup- plies an equal amount of mixture to all six cylinders, gives you all the power from all the cylinders. The vapor is fed uniformly. Reduced vibration, ” lower upkeep cost, more power and more mileage are realized. The most wonderful automobile engine in the world today is under ~ hood of the Chalmers automo- ile. This is the sixth of a series of bul- letins in which the’ wonderful features of the new Chalmers have been ex- plained. Illustrations No. 1 and No. 2 show in an enlarged way the difference in globules before (2) and after (1) being ‘‘cracked up” by the Chalmers

Page 86

I eee For Cuts and Skin-Hurts New-Skin covers’ the wound with an antiseptic, germ-excluding film that dries quickly and resists wear and washing. “Never Neglect a Break in the Skin” Be sure you get New-Skin, not an inferior substi- tute. Smile, but insist, All Druggists — I5 and 30 cents NEWSKIN Co. NEW YORK Have Cozy Rooms For 17c a Day Now made possible by this latest Larkin Factory-to- Family plan. One of three rooms furnished com- pletely for only 17c a day. Take two years to: pay. 800 Beautiful Furnishings Await Your Choosing by een surprises await you in the large amount of furnishing you can do at small expense. High . quality furnishings of tasty and beautiful : design, on easy terms, at rock- bottom prices surely merit your investigation. Big Helpful Book Now FREE Every one of its 104 pages contains intensely interesting offers for the home lover. Write for your book now, ” Larkir Co, vesk®?S™ puttale, WY. You can now learn Taxidermy, the | » the — art of mounting birds, , an- ¥ gg es skins, pase by ih thie ¢ trophies. Dec- lount . orate home > teats trappers. nat need taxidermy. teresting nating big profits. Join our school 000 stadents. — Merve FREE AIR INTAKE —— wee we wow ee, FINE MESH WiRE GAUZE If you own a motor- cycle here is a way to prevent the carbu- reter from clogging the screeninz. fifty cents, as shown in the il- Preventing Road Dust from Entering Carbureters N one of the older models of a well known make of motorcycle some trouble was experienced from road dust and grit being sucked into the air intake of the carburetor. come this annoyance the air intake was fitted with a piece of extremely To over- fine mesh copper gauze. The opening was rect- angularin shape, and the edges of the casting, which was of aluminum, were slightly concave to allow it to fit closely to the heat radiating flanges of the cylinder. The gauze or screen- ing was cut to fit the opening neat- ly, and the top and lower edges were turned over and slipped into place. Then three holes for nails were drilled through both of the flat sides of the casting and the turned over edges of Three finishing nails were used as rivets to hold the gauze in place, by slipping them through the holes from the top and riveting over their ends on the bottom side. The reason this method was used to fasten the gauze was because of the fact that it could not be soldered to the castings as they were made of aluminum.—JOHN A. WEAVER. Save and Filter the Old Oil from Your Car HE writer, in common with other automobilists, has found that the oil bill for his car is a considerable item. Deciding to cut down this ex- pense he constructed a filter, for about SCREEN lustration, and before long saved much on the cost of new First, he placed a small screen at the top of a four- gallon can, let- ting the dirty containing clean oil. COTTON WASTE oil run through FE it into a funnel ,- -—— >, -— waste. From the first funnel it ran into a second, and Save the old oil and filter it by this method from there into the bottom of’the can, whence it was drawn off with a cock. This proved a very satisfactory filter, and one that the readers of the PoPu- LAR SCIENCE MONTHLY would do well to copy.—J. W. Moore. 106 Popular Science Monthly 4 Hundreds of IDEAS For the Owner, Manu- facturer, Dealer, Mechanic in 1920 Motor Annual of the Popular Science Monthly The biggest book of its kind ever published—invaluable to every- one interested in Motor Vehicles and Accessories. It will accu- rately picture and describe more than 400 new devices and acces- sories and give scores of prac- tical ideas to the Owner, Manu- facturer, Dealer and Mechanic. The 1920 Motor Annual will be edited by nationally known auto- mobile authorities. It will cover all important new inventions and improvements to Cars, Trucks and Accessories. Matching the wonderful develop- ment of the automobile industry —(there are six and a half mil- lion Motor Cars and Trucks reg- istered in the United States) is the growth of the Motor Annual. The 1920 edition is limited to 100,000 copies. Order now if you wish to make sure of getting a copy. Cut the Coupon and Cut your Motor Costs Popular Science Monthly, 225 West 39th Street, New York. Please send me a copy of the 1920 MOTOR ANNUAL of Popular Science Monthly. I enclose 35cents. Send post- paid when issued, about Jan. Ist. BE EERE tae 2 hae rer ee St ee ee

Page 87

in. yer ry- les wi ore 11C. ito- ver ind cks Op- try nil- ) 1s ual. | to y if Hing nd sts October, 1919 “Not the name ofa thing, but the What is it P Motorcycle or car? If it is a car, which lamp is out—left or right ? Lamp- unreliability is both dangerous and unnecessary. The known high stand- ards of MAZDA Service are sufficient to make cautious and considerate motorists insist on having MAZDA Lamps—lJamps marked MAZDA. M A ZD is the trademark of a world-wide service to f certain lamp manofacturers. Its purpose is to collect and select scientific and practical information concerning prog- ress and developments in the art of incandescent lamp manofactur- ing and to distribute this information to the cémpanies entitled to receive this service. MAZDA Service is centered in the Research Laboratories of the General Electric Company at Schenectady, N. Y. The mark MAZDA>=~ can appear only on lamps which meet the standards of MAZDA Seér-» vice, It is thus an assurance of quality. This trademark is’ the, property of the General Electric Company, erg © DA. mark of a service”

Page 88

Finger Print Detectives Wanted EN are wanted by the govern- ment, police departments, corpo- rations, banks, institutions and individuals—these men must be trained Finger Print Men—men who have made this work a profession. Big Salaries and big rewards go to these experts be- cause they solve mysteries that baffle the most experienced ordinary detectives. The finger print clew is one that cannot fail because no two people in the whole world make the same mark. You Can Succeed in mastering this fascinating, big money- making profession by studying in your spare time at home. Common school education is all you need. A brilliant career is before you. Finger Print experts travel everywhere, see the country, live in the best hotels and have all expenses paid. There is a crying need for such men right now. This profession is not crowded. Get started at once—right now—and be one of the big men in Mail the Coupon Right NOW! Fill in this coupon and mail it right now. This may be the big opportunity of your life, so don’t waste another minute. en you send the coupon we will send you our Free Finger Print Book Tells you all about finger prints—the big oppor- tunities in this profession, and everything you want to knew aboutit. Send the coupon now. University of Applied Science | f a Desk 1207. 772 Wilson Ave., Chicago B = t i 1 i Please send me Free Book on Finger Prints and f full information about your course of study. , bi \ CIEL coe seas shcwaniep ies psese whose otee ine 4 Hit Address , } | : eee ewe m meee ee ee meee ee eeseeseeeeeeeseseesses 1! 8 i i Say INN st haes hs dies chao heute yy sess 990 to? 250 aMonth lous) bYele) (@laicysleny Trained men are in big demand at good salaries by the Signal De- partment of every large railroad in the United States. Today the opportunities are bigger and better than ever. ; oe RAILROAD SIGNAL MEN tly needed at salaries ranging from $90 up to $250 a ; month, ‘The training necessary to get started in this fascinating work can be easily acquired at home by any ambitious man. a, Write today for Free Book. Get al] the facts before you, Learn about the big positions open throughout the United States. Learn all about our big special free outfit. Write a letter or postcard or send coupon now. DEPARTMENT OF SIGNALING 1810 Wilson Ave., Room 1207, Chicago DEPARTMENT OF SIGNALING ; 1810 Wilson Ave., Room 1207, Chicago Please send me absolutely free and prepaid. without obligating i i , your new book on Signal Engineering. Also all ‘4 the foots on tals profitable work and your Special Free Outfit. { SPECIAL NOTE —If you join the Army or Navy before complet- i ty ing your course, all pay ts will be postponed until you return. An Improvised Saddle with Stirrups ERE is a convenient and inex- pensive saddle for those who have work horses that can be ridden in spare time. It can be made with materials that are always to hand, and constructed at absolutely no addi- tional expense. A folded blanket is placed over the horse to form a cushioned seat, and a circular strap holds it in place. Two side straps are riveted to the main , ent . LS pat Ba i rs ‘ | yi in) r ul Clb | - ‘ | \ ; fi; ty ie el For the amateur learning to ride, a saddle of this sort is a great help strap to hold the stirrups. The sad- dle is now ready for use. The straps are supplied with buckles so that they can be adjusted to individual needs. This saddle is very serviceable and may be used as a means of bettering one’s horsemanship.—G. H. GLITZKE. Method of Removing Broken Pins from a Shaft REQUENTLY, when a pin be- comes rusted or broken off in machinery shafting, the operator, with- STEEL DRIVING PIN HOLE IN SHAFT Broken pins in shafts cause a lot of trouble. Here’s a way to remove them with ease out thought, injures the threads of the hole when removing it. Great pres- sure upon the broken pin may some- times remove it, but if a small hole is drilled through the broken pin and oil poured into the hole, filling it to half its length, and then pressure is applied, the pin will usually come out without further trouble-—WILLIAM FARRAY. 108 Popular Science Monéh _ my , Ce te | + $100.9 $50.9 $25.0 ae 10 CONSOLATION PRIZES oo ; RLING SILVER CIGAR LIGHTER can’ INVENTORS ¥% EXPERIMENTERS $ Use your ingenuity and win one of these cash prizes . by showing some new uses for { LIBERTY BRAND FERRO-CERIUM ; S Or SPARKING METAL Ferro-Cerium is the metal used in cigar lighters to produce the spark showers. It has been developed to such an extent that the results obtained are marvelous, We are anxious to discover new uses, such as sparke ing toys, safe and sane fire works, technical uses, etc. ; Any ideas used will be paid for. ] Write at once for details, sample of Ferro-Cerium, and rules of contest NEW PROCESS METALS CO. 50 E. 41st St., New York = your boy have balanced reading. Besides his pre- scribed school reading he needs the regular relaxation of the right kind of boyreading. Fi dred thousand American boys “4 this important combination in - Help your XU T ACY) Develop Himself “*The Biggest, Brightest, Best Mag- azine for Boys in All the World ad Its absorbing fiction, construc- tive, helpful departments, and timely articles of current inter- est are ‘‘all-boy’’ clear through. Put The American Boy on your family table, 200 a copy on news-stands— $2.00 a year by mail. The Sprague Publishing Co. 23 American Bldg. Detroit, Mich, Full size white en- f ameled tub, nick- eled 12-gallon tank. Closes up in 3 sa. ft. space. On cast roll it anywhere. | Heater attachment or gas, gasoline or 4 kerosene. Water heats very quickly. Drains ched to permanent @ outlet. Simple. Guar- ie anteed. Also indoor SQ Be NG for circular and price. = Rowe Sanitary Mfg. Co. 10173 6th St., Detroit, Mich. Deafness “e Perfect hearing is now being re- saeee stored in every condition of deaf- ) ness or defective hearing from causes such as Catarrhal Deaf- ness, Relaxed or Sunken Drums, « Thickened Drums, Roaring and iy “x Hissing Sounds, Perforated \\ Ee Wholly or Partially Destroyed Cea “©\ Drums, Discharge from Ears, etc. Wilson Common-Sense Ear Drums “Little Wireless Phones for the Ears’’ require no medicine but effectively replace what is lacking or defectivein thenatural eardrums, They are simple devices, which the wearer easily fits into the ears where they areinvisible. Soft, safe and comfortable. Write today for our 168 page FREE book on DEAF- . giving you full particulars and testimonials. ——_ EAR DRUM CO., Incorporated ter: 1143 Inter-Southern Bldg, LOU!SVILLE, KY. All the Parts and Plans ao Model aa $1.00) Model “B”’ 1.50 Buy Either Model Completed, “A” YS 1.50, “B” 2.00. PREPAID : —DON'T SEND STAMPS— Made like a SKEETER, no others will fly, No other can BEAT’ ER, all others soon die; Made in a JIFFY, fly it in the park, Maiden so NIFTY, firm as Noah’s Ark. NIFTY NOVELTY & TOY CO. NEWARK, N. J.

Page 89

All Sizes and Styles Prizes Money-Back Cartridges U. S. Cartridges are sold with the broadest guarantee ever made on ammunition. It is simply this: If you don’t | We make exactly the like them, get your money back. same guarantee with We have authorized every dealer who carries U.S. BLACK SHELLS . . Lf Cartridges to refund, on demand, the price of the whole Gs): a prices box to anyone who doesn’t like them, and returns the You ‘can gaeeuoes - Co. Mich. unused part of the box. pet load in smokeless es 2 or black powder in % The Black Shells and S your money back if in re- you want it. eal- eo g from For all makes of firearms Thoucendeal sheet: ot There is no 22 Long Rifle cartridge possible with 22 rim-fire ammunition. Crs claim they take nse as accurate at distances from 50 to 250 Solid bullet for target work. Hollow- less lead, shoot 1, ate, yards as U. S. 22 N.R. A. Long Rifle point bullet for small game. Cost no closer, with The Black ims Lesmok Cartridges. This is 50 more more. Send for a copy of The U.S. Shells because they nire no yards of accuracy than has hitherto been Game Law Book— Free. rage light ; cing or are as quick - sf aga a UNITED STATES CARTRIDGE COMPANY, 111 Broadway, New York ning They are posi- = h __General Selling Agents: National Lead Company, Boston, Buffalo, Cleveland, Chicago, St. Louis, Cin- . om 2 f DEAF- cinnati; United Lead Company, New York, Philadelphia; National Lead and Oil Company, Pittsburgh; James tively waterproo too. onials. Robertson Lead Co., Baltimore; American Smelters Securities Co., San Francisco; Hingston-Smith Arms Co., ‘e ed Winnipeg; John Hallam, Ltd., Toronto. ~ E, KY. Plans | “B”’ 1.50 ted, “A” MPS— co.

Page 90

‘ FREE- a Marden Lecture-Get It Today v Genuine Efficiency VY More Money V Better Health VY GreaterHappiness V Fearlessness Y Hope Y Stimulation VY Inspiration VY Initiative V Leadership VY Power “% Success Sent Without Cost or Obligation to Forward Looking Men Beside You Desire Put a Check What The Way to Each and All of These is Taught in This One Lec- ture Alone One of Dr. Marden’s 32 Success-Compelling Lectures on How to Get the Most Out of Life (By ORISON SWETT MARDEN, M.D., A. B. Harvard) President of the League for the Larger Life Dr. Marden’s optimistic lectures have helped more than a million men to Greater Happiness, More Money, Better Health and Success. Business Men, Professional Men, Farmers, Teachers and Scholars, Employers and Employees—succe-sful men and women in all walks of life—have received practical, valuable, useable guidance to do greater things in a better way. More than 50,000 men and women have written Dr. Marden in appreciation of the great benefits received by following his teachings. Among the better known are Theodore Roosevelt, Charles M. Schwab, John Wanamaker, Luther Burbank, Judge Ben B. Lindsay, J. C. Penney, Lord Northcliffe and Geo. Whitehouse. Real Success is the result of correct Knowledge put into practice. The Marden Lectures are an accredited source of success-building knowledge. a show you how + rayne a ne. your appiness, your wealth, your efficiency and become USE THIS FREE LECTURE COUPON more successful. Pa ag 3 hand of every young Oe ea: Sagpenppiemeetons a sti i man there would be fewer failures”, says Jacob A. Be OL Liss Drcsdean N. Y. 1 Riis, and this is absolutely true. i 1 I have so much confidence in the good restlts You Pease SONA tO CNAME. .... 22... ccccccccccccccccccccs will obtain by reading and following the suggestions Ce ay ae ) absolutely free, !and advice Dr. Marden has put into this series of all charges prepaid, “Training for Masterfulness, or | Man-building lectures that I will gladly send the first Backi ng Up the Brain”, the first of the series of Dr. jor the series “Training for Masterfulness, or Backing Marden’s powerful and inspiring lectures. , up the Brain”, free of all charges or obligations. Sargent’s Handbook of BY ONE MAN. It’s KING OF THE WOODS. Saves money and backache. Send for FREE catalog No, B 138showing low price and latest improvements. First order gets agency AMERICAN PRIVATE SCHOOLS A Guide Book for Parents A Standard Annual of Reference. Describes critically and discriminately the Private Schools of all classifications, Introductory Chapters review interesting developments of the year, Our Educational Service Bureau will be glad to advise and write you intimately about any school or class of schools, Fifth edition, 1919, revised and enlarged, 768 pages, $3.00. Circulars and sample pages on request, Sawing Machine Co., 161 West Harrison St., Chicago, 1, | PORTER E. SARGENT, 14 Beacon St., Boston, Mass. Prestige Accuracy roof and Dustproof Strap Watch LD AND MARINE Registered U.S. Pat. Off. The Depollier Waterproof Case now adopted by the Signal Corps of the United States Army for the saving of watch movements purchased during the war and for future use. Ordinary strap watches were not constructed to withstand the wear and tear of field duty. A heat-insulated disk protects the delicate move- ment from the injurious body heat} of the arm, which has a tendency to dry or gum up the watch oil. Waterproof Oxidized Case with 14-k Solid Gold Disk on Back and 15-J Waltham Move- ment ° ° ° > : ° $42.00 Write for Booklet _ JACQUES DEPOLLIER SON Menten of High Class Specialties for Waltham Wetches Praasiden Lane - New York, N. Y bois Watch Case Co . Established 1877 stn eal ea taaeseaa Tad Stamped U.S. A. only for the U.S. Army The Depollier Waterp 110 Popular Science Me A Frame to Hold the Fruit. Straining Cloth O prevent the possibility of the straining cloth from slipping over the mouth of a kettle, jar, or pan, the little device here illustrated will prove a boon in canning time. The two vertical pieces may be fashioned from %g-in. thick boards and the crogg slats from 3-16-in. thick pieces. The experienced woodworker wil] No more spilling of fruit juices if you have this strainer frame in your kitchen probably prefer to mortise the ends of the cross slats into the vertical arms, but they can be nailed or screwed in place just as well. The four nails or brads will hold the cheesecloth or other strainer material securely in place.—CHARLES TAYLOR. Make a Hole in the Storm Curtain RIVING through rain, snow or fog is dangerous business at night if the storm curtains entirely enclose the car. The searchlight at the left A’means of operating the searchlight is necessary when the windshield is filmed of the driver cannot be used unless the curtain is unbuttoned. A circular hole, large enough for the arm to be thrust through, can easily be cut in the curtain and patched in the manner shown in the illustration. This will prevent the rain from enter- ing the car but allow the driver to get at the searchlight.—C. C. SPREEN.

Page 91

Cts the Same Old _ Juice ; =the Electricity that whizzes the Big Trolley Car along or pours from the Fiery Little Columbia to drive the Youngsters’ Train LECTRICITY for hustling the big trolley car along the street comes from mammoth generators whose energy is reckoned in thou- sands of horsepower. . The youngsters’ train gets its snap and go from the Fiery Little Columbia. . In both cases it is the same kind of electricity running the same type of motor. The difference is in degree and size. Toys themselves appear to enjoy the frolic when spun around by Columbias. No connection with the house-lighting fixtures is needed—the whole outfit may be toted up to the garret, out on the lawn, anywhere, everywhere, wherever the good time is—and with absolute safety. What a marvelous thing this Columbia Dry Battery is—and what a lot of uses! Motionless, yet moving toys at a merry clip; cold, yet firing Columbia oragepatteries the fuel in autos, motorboats, trucks, tractors, and farm engines; silent, yet giving a vigorous tone to telephones, bells, and buzzers; lightless, yet illuminating lanterns, pocket lamps, and other portables. Fahnestock Spring Clip Bind- ing Posts, no extra charge. THE STORAGE. BATTERY HEN you place a Columbia Storage Bat- tery in your car you equip with definite power guaranteed for a definite time. The famous Columbia Pyramid Seal stamped on the connectors is the symbol of that guarantee. Columbia Storage Battery Service is all around. Stop in and see how easily and gladly they make certain that each and every user gets the actual performance to which his original pur- chase entitles him.

Page 92

Double Your Strength, Improve Your Health and Lengthen Your Life My system of CON- DENSED EXERCISE with my patented Automatic will more than double your constitutional and muscular strength in a short time IT WILL GIVE YOU A Clear Brain—More Nerve Tone — Strong Lungs—A Strong Heart—More Strength in Your Back, Chest, Legs and Arms—. More Resisting Power and Vim than you ever had. or Vital | Strength The AUTOMATIC EXERCISER will forti- fy the entire area of the abdominal walls throughout all its layers. ; Its influential effecton the digestion eliminates the special diet question. It will strengthen the entire organism and insure immunity from the many ills the “busy” man knows so well. It will instantly relieve that brain and body fag. ° It will make nervousness and complications therefrom a thing of the past. WHAT OTHERS SAY Overhead ced a cess Automatic Exerciser “I am well pleased with the AUTO- MATIC EXERCISER. Before taking exer- cise on your machine my blood and liver were'slowand sluzgish—but now! ‘what a difierence—I am full of energy. - “It is worth a hundred times the price I paid for-it.”* -- Wichita, Kansas EARL PINNEY. “The Automatic Health Exerciser is a wonder: It hasdone more for my health and strength in two months than all the exercises and apparatus put together which I have tried in years.” ° MAvRICcE DALY, JR. Daly Billiard Academy, N. Y. City. IF YOU WANT TO DOUBLE YOUR STRENGTH, IF YOU ee SGA Rae He se sad éx- -TIONAL erciee ste small FORM, SEND FOR . - e R o! k “ LIFE’S BACKBONE hich gives a full description of the Automatic Exerciser, how it works, what it Wil do, ete. Don't fudge my machine until you have read this booklet. I will send it on receipt of 4 cents postage. eis »* Prof. ADRIAN P. SCHMIDT 1941 Broadway New York City FREE PRACTICAL BOOKS FOR PRACTICAL MEN (1) Automobile Troubles and How to Remedy Them (2) Automobile Ignition, Timing and Valve Setting, Self Starting and Lighting, including FordSystem (3) Motor Trucks, with Special Chapters on Ford (4) A B C of the Motorcycle (5) Gas Engine Troubles and Installation, with Trouble Chart (6) Motor Boats: Construction and Operation (7) Questions and Answers for Automobile Students and Mechanics (8) Gas, Gasoline, and Oil Engines, including Glos- sary (9) Cement, Its Uses in City and Country The price of each of..these books is $1.40, Postpaid. We-will'send anyone of them to you FREE if you will send-tis two subscriptions to POPULAR SCIENCE MONTHLY at $2.00 a year. : Book Department POPULAR SCIENCE MONTHLY 225 West 39th Street, New York City Exerciser | Making a Drill-Press from Old Pipe and Fittings ITH a few pieces of gas-pipe and fittings a very useful drill- press can be made. Take a piece of gas-pipe, 10 in. long, with one end of it threaded and a 90-degree L fitted to it. To this couple another piece of pipe 5 in. long. About half an inch from the ADJUSTABLE TABLE SET SCREW Easily constructed and substan- tial enough to last a lifetime. Ac- curate holes are made with the drill end of this, drill a hole the size of the screw on your hand drill, from which the handle has been removed, and find a nut to fasten it on the top. Now take a piece of strap-iron ¥ in. thick and bend this around the longer piece . of pipe. - Make it tight with a bolt or rivet, so that you can bend the other - end of it around the drill, as seen in the drawing. Be sure that the drill is now in a vertical position. Now take a piece of gas-pipe about eight inches long and of such diameter that it will slide into the 10-in. pipe. Grind out and polish the two pipes and you will get a very good fit. » Connect this smaller diameter pipe with the outlet of a T-joint.. Now attach a second T-joint to the first with a piece of pipe of sufficient length so that the opposite openings cor- respond with the center of the drill. Through this second T-joint run a piece of round iron or pipe, onto which fasten an iron plate (a cover from a kitchen stove will do), for the table to rest your work on. Put a thumbscrew in the middle of the T for fastening the table at the desired position. For the feeding mechanism procure an iron bolt about 8 in.-long and 14 in. thick, with half of its length threaded. Now drill a hole the size of the bolt perpendicularly in the short piece of piping, between the two couplings, and about an inch from the first one, and insert the bolt into the hole. Above, close to the piping, fasten a collar, as seen in the drawing. 112 ‘Popular Science Monthly! Place a knurled adjusting scre middle of the anthreaded pall of ie bolt. Now run the nut on the bolt up to the connecting arm and fasten it to or between the strap-iron bracket By turning the adjusting screw the upper part of your drill-press can be raised or lowered. For fastening the drill-press to a table ora bench, attach a common clamp to the remaining open coupling.—STEVEN Nacy. The Pocket Flashlight May Become a Spot-Light HERE are times when the auto- mobile breaks down out on the road and failing a “handy repair light,”’ it is useful to know how to connect a pocket flashlight with the storage battery in order to provide illumination to repair the break-down. This may be done by removing the flashlight’s dry battery and plugging up the lamp end of the cell container with a wooden plug or cork. Drive an upholstery nail or ordinary tack into the center of the cork to make the contact with the lamp and connect one wire to it. The other wire is grounded upon the metal container and both are threaded through a hole in the cap on the bottom end. Care should be taken to see that the lamp in the flashlight is of the proper voltage. The 6.2 volt lamp with the miniature base should be used where the car lamps are labeled 6-8 volts, and where the voltage is the higher the lamp should be bought to correspond. The flashlight with the large re- flector or the so-called ‘“‘miner’s trouble PUSH BUTTON WIRE af =| =sa7 i KR | 4 mee TO INSTRUMENT OARLOCK TO HANG BoarRD UP FLASHLIGHT Transforming the pocket light into an automobile spot-light is not so difficult lamp,” two- or three-cell type, costs from $1.50 to $2.00, and it can be made into a practical trouble lamp and spot- light for the automobile. It is better than the ordinary automobile spot- light, for when the top curtains are attached, this type of lamp is worsethan useless. Make a dummy battery of a piece of broom handle of the proper size and drill a small hole through it, capping it with a piece of brass. The lower hali of a nickeled shaving stick box is just the size for the other end of the dummy battery and the other wire is soldered to it, both of course, being threaded through the hole previously bored in the cap of the flashlight. The light may be turned on and off with the push button in the handle, and; providing sufficient flexible cord is provided, it can be used in any part of the car.—C. B. EDWARDS.

Page 93

per nere and the ond. re- ible HANG HT osts ade pot- tter pot- are chan e of and ping hali just nmy ered idea d in and ndle,

AADAVAM

you never had a chance! “Four years ago you and | worked at the same bench. We were doth: discon- tented. Remember the noon we saw the International Correspondence Schools’ advertisement? That woke me up. | realized that to get ahead I needed special training, and I decided to let the J.C. S. help me. When I marked the coupon I asked you to sign with me. You said, ‘Aw, forget it!’ “IT made the most of my opportunity and have been climbing ever since. You had the same chance I had, but you turned it down. No, Jim, you can’t expect more money until you've trained your- self to handle bigger work.”

| INTERNATII IONAL _GORRESPONDENCE SCHOOLS 4. SCRANTON, PA. lain, wie tins me, how I can qualify for the posi- uae or in the subject, before whichI mark X. ELEOTR10AL ENGINEER SALESMANSHIP F'ectric Lighting and Railways ADVERTISING Electric Wiring Window Trimmer Telegraph Engineer Show Card Writer

Sis se There are lots of “Jims” in the world—in stores, fac- Telephone Work Sign Painter Mechanical Draftsman {LLU STRATING tories, offices, everywhere. Are you one of them? Wake up! Every time you see an I. C. §. coupon your chance is staring you in the face. Don’t turn it down. Machine Shop Practice caroonter Toolmaker BOO PER mag ny! and Typist Cert. Public Accountant TRAFFIC MANAGER Railway ———— Commercial GOOD ENGLISH Teacher Commer School Subjects Mathematics CIVIL SERVICE Railway Mail Clerk AUTOMOBILE OPERATING Anto Repairing Navigation | Spanish | Gas Engine Opersting OIVIL ENGINE Surveying 4 Ma lapping | MINE FOREMAN OR ENGINEER STATIONARY ENGINEER [ Marine Engineer Ship Draftsman ARCHITECT Contractor and Builder Right now over one hundred thousand men are pre- paring themselves for bigger jobs and better pay through I. C. S. courses. Architectural Draftsman Concrete Builder Structural Engineer PLUMBING AND HEATING Sheet Metal Worker Textile Overseer or Supt. AGRICULTURE French CHEMIST Poultry Raising Itallan

Name Present Occupation You can join them and get in line for promotion. Mark and mail this coupon, and find out how. INTERNATIONAL CORRESPONDENCE SCHOOLS

Street and No

City State

Canadians may send this coupon to International Corresp , Montreal, Canada Box 7654, Scranton, Pa.

eka eee ee pe RS St AAAI ee 3 <A te, URI RETA ee ea eal A A BB - ~ Sse NS ee eee — YS ee ee oS) hemo setae poem eee

Page 94

' STEGER The most valuable piano in the world § The purchase of a piano should be the decision of a lifetime. The enjoyment of its possession should ripen with succeeding years. It is to meet this standard the Steger Piano is made. Today, Steger Pianos of wondrous tonal and artistic beauty are find- ing their full-measured destiny in thousands of American homes. Steger Pianos and Player Pianos are shipped on ap- proval to persons of re- sponsibility. § Write for the Steger Style Bro- chure and convenient terms. Steger dealers everywhere. STEGER & SONS Piano Manufacturing Co. Founded by John V. Steger, 1879 Steger Building, Chicago Factories at Steger, Illinois | Sensible Neckwear Why spend $18 to $25 a year for collars and laundry bills when $2.10 will cover the entire expense. Six Challenge Cleanable Collars Bi’ will give you collar comfort and economy for twelve :months: They never wilt and 5) when soiled may be instantly cleaned with a little’soap and water. Always ready to wear. Made in all popular styles and sizes. Ask your dealer or send 35 cents for sample. State size and style. THE ARLINGTON WORKS = Owned and Operated by S|. E. I. du:PONT de NEMOURS & CQ : + Wilmington, Delaware Set-Screws—Their Uses and Abuses By Charles R. Fisher HE problem of set - screws, as used in modern machinery and de- vices, is one of considerable impor- tance. Referring to the illustration, the set- screw shown at A is flat on the end. This form is frequently found in gen- eral service, but it has certain objec- tions. It has not the gripping power of one with a cup point. When it is brought to bear on the surface of the part forming the shaft, wheel, or coupling combination, it may or may not hold. Of course the flat endedscrew will hold in many cases, but it is us- ually where it does not require much pressure .to hold the parts firmly, and the screw is an oversize for that purpose. In most cases where the flat ended screw is used grooves will be formed in the shaft where the screw cuts in as the shaft turns. To make it hold the set-screw is again tightened in the groove and a part of a turn is given from time to time. It is obvious that the shaft will soon be ruined by this method. Next let us observe the extremely pointed set-screw B. The point is hardened, and usually ground quite sharp, so that a hole is made in the shaft where it is set. The point is intended to give a good grip. This type of set-screw must be reset every time the part it holds is adjusted. If the collar is to be turned on the shaft for any reason the point will tend to enter the old hole if not turned entirely out of its original position. Owing to the shortcomings of the other two types, the set-screw with the rounded end is usually employed. The oval ended type C can be tightened on to the shaft with considerable force without actually denting the latter. Some builders of machinery make an excellent design of screw which is about midway between the round and the pointed end. Don’t Crack the Collars and adjust In making even a casual examination of machinery and shafting in mills, shops, and other plants, one finds set- screws. in service under varying con- ditions. The condition found prevail- ‘ing in ‘a number of collars used in an electrical power plant is shown at D. These collars were used. on either side of the shaft journals -for-the~purpose. 114 Set-screws are of different shapes, and you should know how to insert each kind properly Popular Science Monthly Ei of retaining the pogi- tion and alignment of the driving pulleys. The eol. lars were not provided with shoulders for strengthening, therefore a number were fractured as shown. In some cases the defect had been overcome by shrinking a band of wrought iron around the collars. In other cases the collars were permitted to remain cracked. In one instance a collar wag provided with a strengthening shoul- der, asshown at E. It was found in some cases that the fracture in the collars was due to tightening up the set-screw too hard on the shaft. In other instances the cS use of set-screws which were in a tapered condition brought about the split. If the screw tapers, the deeper it is inserted the more liable is the expansion to crack the collar. There is always considerable = an- noyance when set screws are used which are too long. An _ unnecessarily long set screw is liable to catch the clothing of the workers and do damage. A _ long set-screw is likely, also, to become bent as shown at F in the illustration. In a certain flour mill there were found long set-screws in collars as shown at G. This system is a poor one. In some cases, instead of washers, some unusual parts were employed to fill in the space. Sometimes the threaded part of the screw was worn out and a hole was drilled in a bushing substitute. The bushing was drilled and tapped for the set-screw and then brazed into the hole in the collar or wheel. Use the Right Sized Screws Fractured portions of set-screws, with the defective part at the edge of the hole, as shown at H, are not un- common. Quite a number of in- stances were found where the set- screws had come in violent contact with some object and were bent over and partly broken off. When a set- screw gets in this condition the only remedy is to substitute a new one of a shorter length. At I, J, and K, three set-screws are illustrated showing comparison of sizes. If one were to look through some of the shops he would soon locate set-screws in use that were a great deal larger than was necessary. The oversize set- screw I is.liable to bulge the-part into...

Page 95

Posi- ment col- Iderg mber some 1e. by iron S the main ’ Wag houl- id in | the le to the hard In s the Tews in a ition ; the crew eper the the Track ways an- 1 set used long. arily . the the do long kely, ‘ome tion. were 3 as poor hers, d to the worn hing rilled then ir or "ews, re of ; un- in- set- itact over _ set- only of a 3 are izes. f the Trews irger : set- into... r a re .... There. are other ways of ena- which it has been inserted and f racture the metal. Often a set-screw will be found in use which is too small, one of which is shown at J. In this case the set-screws have not body enough to grip firmly. The screw with a proken or worn head is shown at K. Such set-screws may be found in our best shops. The monkey-wrench in the hands of a new man often causes defects of this nature. Many times the hubs of gears and wheels are cracked because of un- necessary pressure on the set-screws. This is shown in the illustration L. The set-screw is fitted in the shouldered portion of the hub. Perhaps the set- screw point is placed in a depression in the shaft. The result is that the set- screw is forced outward, often to the point of cracking the hub. It is not unusual to find samples of crude work with set-screws as seen at M. Theshaft is too small for the hole in the collar or hub, and the workman tries to overcome the difficulty by adjusting the set-screws to take up the difference. The chances are that the shaft will be thrown out of line to some extent, unless there are an equal num- ber of set-serews. In the case shown the set-screws are two in number and so set that the points force the shaft off center. Sometimes the shaft is held in the center by using strips of metal as keys on the side opposite the set- screws. This is a slipshod way. of doing work. A better way is to insert a sleeve, but the only proper way is to remodel the parts and adjust them so that the collar fits snugly to the shaft. The illustration N shows a set-screw that can be driven with either a screw- driver or a monkey-wrench. A Three-Horse Equalizer on a Two-Horse Tongue HENEVER it is desired to use three horses on the usual two- horse tongue, the arrangement shown Attaching three horses to a two-horse team isn’t hard if you know how to do it in the illustration will be found to be practical. Measure off ‘the distance from the end of the equalizer to the — and: vice versa on the other side. bling three horses to work on a two horse - tongue, - but this. arrange- ment has less side draft than the majority.—CHARLES TAYLOR “VANKEE TOOLS Multipl pon ie - Here’s one of those famous “YANKEE” tools that follows trouble into its hole; that goes right in after it and repairs it, where the ordinary tool could not be used. The “YANKEE” Ratchet Breast Drill will do anything that any drill of its size will do out in the open, and works perfectly in awkward corners where other drills will not work at all. It has two speeds and five adjustments: (1) Plain Drill, (2) Left-hand Ratchet, (3) Right-hand Ratchet, (4) DOUBLE Ratchet, (5) Gears Locked... Suppose you have work where you cannot make a full revolution with the crank; - Tear down the job? Not at all! Use the Double Ratchet. The slightest movement.of the crank in either direction gives the drill a continu- ous forward movement. No lost motion— Speed and no lost-time! Ratchet Adjust- ments changed at a finger touch and without re- moving drill from work. Speed Shifter at hub of crank; Ratchet Adjustment shown between bevel gears. “YANKEE” Ratchet Breast Drill No. 1555—Length 17 in. Three-jaw chuck for round shank drills up to 4% in. diameter. Price $10.00 Your dealer can supply you. No. 555—Length 1714 in. Two-jaw chuck for holding both rounds and squares. Write for free “YANKEE” Tool Book illustrating tools that do work that common tools cannot do; Ratchet Breast and Hand Drills, Automatic-feed Bench and Chain Drills, Ratchet Tap Wrenches, Removable Square-finished Vises, Plain, Ratchet — and Spiral-Ratchet Screw-drivers, etc. NORTH BROS. MFG. CO. PHILADELPHIA EST IE ae ee OO aie eS

Page 96

Season S finest’ We back this Trade-Mark with our Reputation, cycling days are here Get astride your Dayton Bicycle and enjoy the finest cycling days of all the year! Use your Dayton for work—or for play—to save your time— earn you’ money— give you the new vigor and “zip” that comes from good, sound, pleasurable exercise! Remember: Every Dayton Bicycle bears the famous “Davis-Made" trade- mark—your absolute guarantee of top .. quality and complete satisfaction. Remember: The Dayton is made in the world’s largest factory devoted to the manufacture of bicycles. Remember: Handsome, splendidly designed, easy-running, long-wearing, and built and backed by a great face tory with twenty-five years of bicycle experience — that’s the Dayton! Re- member these facts when you buy a bicycle—and buy a Dayton! See the Dayton line at your dealers, Write us today for Catalog 44. Cycle Dept., THE DAVIS SEWING MACHINE CO., Dayton, Ohio Big Band Catalog sent free Pe ot you need—irom a d the cornets in the world. Used by the Army and Nav; catalon liberally illustrated, fully Sencry’ tive. . Mention what instru Free trial. Easy ment Tatorests Sia by payments. leading music stores everywhere. LYON & HEALY 67-71 Jackson Boulevard, Chicago SMOOTH-0N HOUSEHOLD CEMENT SU FG - Basyt to apply as putty— ting as iron. Repairs leaks;. cracks, and breaks at little cost. Get a Can of SSMOOTH-ON IRON CEMENT NO.1for every Household and ‘Auto repair. Stops Auto Radiator. leaks. 25c. and 50c.°at* Wiltelor! stores. 1 lb. 50c. rite for interest- -ing’Booklet show- 602. 25 ing dozens of uses. SMOOTH-ON MFG. CO. Jersey City, N. J.,.U, 8. A. REPAIRS ~|. Cot ont ont this ad and mail it to us, with your name and dress (no money); and we will send at om aaraes Hannan RAZOR by return mail, pos the razor for 30 days FREE; then Owe oT, ciel ke it, pay 98 us $1.85. If you don’t like it return it. _MORE COMPANY, Dept. 397 St. Louis, Mo, AN EASY WAY TO MAKE MONEY -2:: plod along on a small salary, Be independent. = in the Fn re- iring business. One man Fay “I made $60.00 the first lay.”’ ones fe avgrene e $200 to $500 a month. For" little ital need: Jobs plentiful. Ever: Every Se motorist a pos- e pinay No experience need We teach you. GHALER Tire pepew Gatiit Improved Wrapped Tread Method Used by Tire Manufacturers olen. as work as the bi g high waits the on outfits. 4: boy feecae watching or : _ FREE Book ie tale nee to Take ig moter. Ul os delay. Write quick. - C. A. SHALER co. if 2109 Fourth St. | Waupun, Wisconsin 116 ‘Popular Science Monthly Use Old Safety Razors to. Sharpen Pencils A CONVENIENT tool to have on the desk for cutting paper. op sharpening pencils is a safety razor blade. A neat and serviceable handle for it may be made from a metal refillable pencil. Cut off part of the LEAD GRIP GENT OVER ED OVER EDGE OF Another use for the old safety-razor blade _ is to transform it into a neat paper-cutter - shell at the tip and slot one side to take the safety razor blade. The small clips used to hold the lead are bent over at the end to grip the end of the blade. After slipping the blade into the slot, the bent ends are caught on the edge of the blade. A few turns of the head of the pencil clamps it rigidly in place.—THOMAS W. BENSON. An Emergency . Motorcycle Hub Repair HILE twenty miles from home recently I had the experience of having the ball-races and bearings of the front wheel of my machine go to pieces. The wheel locked, the ma- ehine spun around in the road and stopped, and for a few minutes it looked as if I was there to stay. I took off the wheel and removed the cones, but they were far beyond hope of repair. I had to find some way to move the machine. The axle was a long one, the type that is used to prevent the fork rockers from turning over. After re- moving all the particles of bearings and ball-races, I set the cones down just as tight as I could turn them with a wrench—the axle was of the knock-out type. I then put the wheel back, but instead of its turning on the bearings and cones it turned upon the axle, and the axle turned inside the fork rockers. f FORK STEMS & ROCKER ARMS it~ srones—| i HUB SHELL “ 1 CONE SET DOWN TIGHT" WHEEL TURNING ON AXLE INSTEAD OF BEARING Ball bearings are liable to become faulty at any time. Here is an emergency repair I then ran a generous quantity of oil along the axle and away I went just as nicely as if nothing had happened. The parts got a little warm, but I oiled them every five miles and so made the twenty miles home without any diffi- culty. Upon taking the arrangement apart nothing seemed to have worn out and I “S-’- "easily fitted new parts.—JOHN E. Hoac. “®

Page 97

onthly } to ‘Ve on er. or razor landle metal of the OF lade. Itter - de to The id are nd of e into ht on rns of igidly Ity air f oil st as ned. piled » the diffi- part , 1919 I love my pipe and good old Velvet— ndl eR OCC CE ETE RIE TERE LEE ORE My comforters in adversity, my wise counselors when problems vex. Companions of my loneliness and sharers of my happy hours. Their friendliness has made me feel more kindly toward my fellow men. They have made this old world a better place to live in. ! ‘Tlove my pipe and good old Velvet; ‘no one shall take them from me. aback for % Copyright 1919, Liggett & Myers Tobacco Gon, = ee Oe > es ea “f

Page 98

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 goo” pay, but it is the first step toward success in Mechanical or Shocrural 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 28 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. Thousands 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 miail 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. ee eee ee = TEAR OUT HERE See eee oe INTERNATIONAL ., CORRESPONDENCE. SCHOOLS » SCRANTO Explain, e, how I can cea for the Se : lity

DRAFTING = se one DRAFTING ADVERTISING SHIP at ak Show Card Writer RIOAL DRAFTIN Sign Painter I D ine ILLUSTRATING SHEET METAL DRAFTING Cartooning aa etn BOOKKEEPER BRIDG and ist MACHINE DESIGN Cert. lic. eee Gedets Eektiee eee oe MANAGER Electric Railways wa: (a tant Bice Wing a eer Telephone Work . Common School Subjects : oh a ENGINEER Mathematics og oan debe meng OIVIL. SERVICE civil ENGIKEE Railway Mail Clerk OIviL INEER AUTOMOBILE OPERAT'G and Mapping Auto Repairing atin ENGINEER PLUMBING AND HEATING Marine Textile Overseer or Supt. AROH OHEMI Contractor and Builder Navigation ~- Spanish Concrete Builder AGRIOULTURE](_| French | Structural Engineer Poultry Raising! Italian Name. Present Occupati Street and No. City, ~ State send this to ‘Schools, Montreal, Canada. .

Making a Bevel Gage for Transferring Angles HE bevel gage is very handy for transferring angles and bevels. For instance, a slide with angular sides has to be filed and fitted to a machine \ (fm

The completed gage is used for obtain- ing angles and depth of machinery part that it is to work in. The gage may be set to the existing angle of the side already finished and the part to be worked upon may then be machined and filed to the exact angle, thereby making the two surfaces fit exactly together. It may also be used for obtaining the depth and angle of recesses that are within its range, and many other like measurements. ’ Both the blade and beam should be made of spring tempered steel, which is not hardened. If this is not ob- tainable ordinary soft steel may be used, but it is not as good on account of its liability to bend and dent easily. In making the blade, lay out the slot and finish it to size before starting on the outside surfaces. The separator should be riveted into place before the slot is quite finished so that no part will be out of alignment. The wing- nut may be worked out of a piece of Y-in. cold rolled steel. Both the nut and screw take a 10 by 32 thread. Be BAYT | ve

my = we

_ oe BYETS— aed k-$—1" lhe 1 RS The plans are first laid out in detail, so that later each part may be trued up very careful to leave the parallel sur- faces exactly straight or else the bevel

Popular Science Monthly. Don’t Worry | About Punctures Treat Both Bicycle Tires with NEVERLEAK TIRE FLUID and forget about costly repairs

Your Tires Will Last Twice As Long

25c a tube at all dealers Buffalo Specialty Co. Buffalo, N. Y.

will not-be’aeccurate.—-A. ‘DANE, .~: 118

DIAMONDS WA TCHES oNCREDIT | SEND FOR FREE CATALOG There are over 2,000 pho’ illus- trations of Diamond ngs, Diamond - La Vallieres, ee Denes ond Scarf Studs, Watches Wrist Watches; also our wonderfulsh mond Clusters maaeacse 8 Diamond

Loftis Perfection Diamond Rings Each Diamond is specially selected by our diamond experts and is skil- fully Fegunted in our famous Lof- tis ‘‘Perfection’’ 14-karat solid gold reong ring, possessing \S pros ben a “g delicate grace $10 <-ecl $5 a Month. buys a $50 Ring. 20 bores Sr tig ~ own, ir zoe Month, buys a Every Article a Gerke pone | Catalog is specia a and priced unusuall: : tow. Whatever you select will be sent prepaid by us. You see in your own hands. If er y one-fifth o: eek pe price and keep it; balance divide me cat | amounts, spayablemonthly. Stand- ard world-renowned watches on terms as low as $2.50 a month. Send for Catalog. LIBERT + BONDS ACCEPTED, ond § suet ine the articien

OF TI The o Hotere Credit Jewelers hen boned at N. State St. BROS & CO. fs erenen IN LEADING CITIES

SEXUAL KNOWLEDGE ILLUSTRATED By WINFIELD SCOTT HALL,M.D.,Ph.D. SEX FACTS MADE PLAIN What every young man and Every young woman should know Mie eae eat oe le now What every parent should know oe pages—many illustrations commendations, on request. rapper le of [__avenican PUB. CO.” 1017 Winston Bide. Philadelphia

UNSIGHTLY Via by) SEND FOR BOOKLET SHOWING PHOTOS ) OF MEN WITH AND WITHOUT M The Perfect Leg Forms # " P PERFECT SALES CO.,140.W. Maheld Ave., Dept..5,,Chicago JU...

Page 99

| S88 wm October, 1919 A Cleaning Stick for Taper Holes T is absolutely necessary, in accurate I work, to insert a tool or center in a clean taper hole. If there are any rticles of dirt or metal cuttings in the holethetool or center will be thrown out of true a few thousandths of an inch and the work ma- chined will be inaccurate to just that amount. The machin- ist usually takes a piece of waste to clean the taper, but the illustration shows a little device that will do the cleaning much better. The tool consists of a piece of wood, turned to snugly fit the taper, with a handle on the other end. The taper part is then fluted like a reamer or tap and a piece of felt glued to its contour. As this fits the taper hole closely the dirt is swept out and falls, into the flutes.—CHARLES R. FISHER. The cleaning stick assures you of an accurate hole Measuring Water without a Graduate NCE, while developing films, I was handicapped by not having on hand any graduated glass measures. I had to measure one four-ounce quantity and one eight-ounce quan- tity.. I happened to see in a corner of the kitchen an empty glass bottle that had contained beer (poor thing) , ald A f, he a ly il Nh af Lost your graduate? Get a certified bottle and make your measurements accordingly and on its label was marked “con- tents 12 ounces.” I immediately took from the cupboard three drinking glasses of equal size, filled the bottle up to the neck with water, and poured this carefully by degrees into each one of the glasses. As soon as the same amount of water was in each glass I had my task finished for the liquid-was now measured out in three four-ounce es 2 “Nothing wrong— except your nerves!” VER-ACTIVITY or worry have drained the nerve cells of their resérve fuel. The question of what to do in such a crisis no longer puzzles those who know from their own experience of the value of Sanatogen. They know that a few weeks’ regular use of this natu- ral food-tonic seldom fails to strenghthen the system and compose nerves that are “hungry” be- cause Sanatogen gives the cells purest albumen, easily and quickly assimilable, and organic phos- phorus —“ in such a form,” as Dr. C. W. Saleeby says, “that the nerves can actually take hold of it.” Thus it is but natural that so many Sanatogen users are able to endorse the remark of Arnold Bennett, the author: “The tonic effect of Sanato- gen on my nerves is simply wonderful.” Is this not assurance that Sanatogen is capa- ble of helping you as it has helped others? Sanatogen is sold by good druggists every- where, 1n three sizes, from $100 up. Write today for interesting booklet to THE BAUER CHEMICAL CO., Inc. 115 West 18th Street, New York City S seh _ Endorsed by Physicians the World Over censtsndreurprgpeameryess $ BLACK BEAUTY The world’s most ma pont. bo le—Black Beauty! ia ig factory, of the finest materials obtainable and with 18 Exclusive Fea- tures. Yet costsno more than an ordinary wheel—we ship direct at wholesale price. No middlemen’s profits! Absolute 5-yr. guarantee and free accident insurance. WRITE TODAY for Catalog (in col- ors) FREE, 20Styles. Tell us model you y want. Send no money—we ship at our . own risk. No waiting. Keep wheel or return at our ex- pense. If ens) pay small deposit, then $1 a week. r factory prices. Lowestin the Sundries &, becca TIRES, lamps, horns, etc. ¥ everything for cyclists. Free Sundries Catalog. Build Your Own PHONOGRAPH It’s Easy With Our Help materia!, blue prints — and ful in instructions, nh Be oe ou can make fine pro‘ ie Building phonographs for your Write Today for Our Free Blue Print Offer Agents wanted for our ready built phonographs Choraleon Phonograph Co. pt ates — pin SIE i toe oe 8 nc ay ere maeptinne e Ny ar | we HAVERFORD CYCLE CO., Dep.G72Philadelphia We'll: Send You a Lachnite Big pian in 1 Vulcanizing We manufacture the An- derson Vuleanizers and teach you the Famous An- derson Method of Vulcan- \\ izing in five to ten days in "| our State School nearest (J fund your money. Many 8 ~~ eee make! Visit the city of: our near- ere. you can all othe er pete and hear their Method of doing the work; then visit our poperson ee °T send it send ALachnite: mounted in'a solid ' = will send it neepene stent to your home. When **Send me |? gold ring ~~ 10 days’ fone y rely deposit. $4.75 with the postman and then wear the fing tor 10 D full dave. “a you, or if friends c. elt your an ) diamond, send it back. But if if you decide to buy it $2. en ‘paid. 5¢ a month until $18.75 has be Tell h of the | | Write Send your name now. ell us which of the {J b ladies’ or men’s). Be sure to send finger siz . MaroldLac amen Co. boo 12.N. Michigan Av. ‘Devt 1207 Culcaee a

Page 100

Reading, Pa. The Salesman’s Friend Luden’s quickly relieves dryness, huski- ness, soreness. Refreshes the mouth after smoking; purifies the breath. A handy friend to carry at all times. Look for the familiar Luden yellow Menthol Cough Drops ' Grve Quick Relief Violin, Hawaiian Guitar Ukulele, Guitar, Mandolin, Cornet or Banjo Wonderful new of teaching note music by mail. To first in each locality, we'll give a $20 superb Violin. Mandoli Bice Vulcan” Ink Pencils The ONLY perfect, non-leakable pencils at moderate v1 \e = an, $1.50 Two Sizes— 4% and 54% inches. Extra Size— 8 inches(black only) $1.75. Your name in gold inlay—$.35. FREE—Liberal supply of ink with retail orders, Agents wanted. Big profits J.F. ULLRICH & CO., 27 Thames St:, New York Biulele, Guitar, Hawaiian Guitar, Cornet or Banjo absolutely free. Very small charge for lessons onlyexpense. We guarantee success or no charge. Complete outfit free. Write at once—no obligation, SLINGEBLAND SCHOOL OF MUSIC, Dept. 402, CHICAGO, ILL, 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-Bookon 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 the SCIENTIFIC AMERICAN —- are probably aware of the act 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 in its columns. MUNN & CO. SOLICITORS OF .PATENTS 683 Woolworth Building, New York 624 F Street, Washington, D. C. “Tower Building, - Chicago, Ill. -— “DCh’T SHOUT” “I hear you. I can hear now as well as anybody. ‘How?’ With THE MORLEY PHONE. I’ve a 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. Anyone can adjust it.” Over one hundred thousand sold. Write for booklet and testimonials. THE MORLEY CO., Dept. 797, Perry Bidg., Phila. cy Monthly Payments = ¥ 17 Cents a Day Pays For the mellow-toned Symphonic Piano. Several beautiful models in genuine Mahogany, Oak and Walnut. Guaranteed 25 years. Sold the celebrated Larkin Factory-to-Family way. Many music Lovers have saved $100 to §200 in buying Symphonics. Our plan permits 30 days’ trial in your home. Four years’ time with- out interest. Convenient monthly payments. Ask today for FREE Catalog illustrating and describing Symphonics. Show ~° Symphonic Pianos Also Player Pianos and Grands instruments in actual colors. . Please state whether interested in the Symphonic Piano, the Symphonic Player Piano (which any- one .can play).or the Symphonic Baby GRAND. Write now for your Catalog. Latkhitr Coo Desk PPSM-1019, Buffalo; N. Y. 120 Popular Science Monthly: Fitting Piston Rings Isn't an Easy Job MYX and varied are the hints and tips which have appeared within the pages of PoPULAR SCIENCE: MONTHLY from time to time with: reference to piston rings, yet, judging! by what has not been written, I am afraid very little is known of the funda. mental principles underlying their action. But nowadays, when, owing to personal predilection or enforced econ- omy, sO many owners do their own decarbonising, it would surely be better if amateur mechanics more thoroughly understood the principle and action of piston rings. The Behavior of Gases in the Cylinder I will, therefore, try to throw a little light on this important subject, and would like to add, in passing, that GUODGEON Fig. 1—An exaggerated sectional view through a portion of a cylinder what follows is not mere theorising or, hearsay, but the result of years of personal experience in car doctoring. Fig. 1 is an exaggerated sectional; view through a portion of a cylinder, piston and ring—the clearance be- tween the piston and cylinder wall and between the ring and groove being purposely exaggerated for the sake of clearness. Suppose combustion to have taken place. Then the small arrows show how the products of combustion, or gases, as they are generally named, press in all directions. The piston, of course, moves down. The gases, in their efforts to find the line of least resistance, pass down between the top of the piston and the cylinder wall, and, meeting the ring (Fig. 1), force it hard down on to the bottom side of groove B. Leaks Past the Rings The outer face A of the ring makes good contact with the cylinder wall owing to the considerable and contin- ual friction between the two, so noth- ing passes between them. But the gases have easy access to the back of the ring (as shown by the long arrow), and are only prevented from blowing right through by their own action in forcing down the ring on to the bot- tom of the groove, as already stated. From this it follows that the bottom face C of the ring and the bottom face |B of the groove.form.a joint of which. = :

Page 101

October, 1919 the efficiency is very important. It PS Se FG ee | peeks. ee js usually thought that gases blowing . s ee past a piston, pass between the outer a face of the ring and the cylinder wall. nts Such, in 99 per cent of cases, is not so. red. As already stated, the continual fric- Ce tion between the two is sufficient to ith’ make and keep a gastight joint. But ag there is very little friction between C am and B—a small la particle of soot Y, - between them, a YA ‘ bruise or “rag” Y to _ raised in careless Y | - replacement be- Y wn ing sufficient to UY be cause a serious Fhe is! leak via the back WH ple - of the ring. PISTON The existence Y eatin of this “joint” é may be easily tle oS verified by hed i WALL moving a ring = from a piston of Fig. 2 ; The email ; an engine that arrows show how the e has done any FPGrcctics: | The Great Task of Construction , hundred miles upwards. The bottom With the coming of peace the Bell present excess burden of traffic and side of such a ring would be found to System faced an enormous con- provide for future requirements. - be very much more brightly polished struction program. Conditions Extension which cates for immedi? than the top side. Therefore, when Xe f a al d 2 Sake ae ‘cal Y replacing a ring, be sure that the arising rom war resulte in the ate demand, on Yr is uneconomical Z brighter side is placed downward. It wiping out of the reserve equipment and calls for continuous work of is also very important, when replac- | 20rmally maintained, and necessary such acharacter as to be frequently "ing rings, to keep each ring to its to give prompt connection to new detrimental to the service. ee own groove. subscribers. The release of industry ‘ The top sides of ring and groove and accumulated growth of popu- During the war the Bell System de- Be form a similar joint, but on the lation now makes telephone de- voted all its margin to the needs of of. induction stroke only. Now the pres- mands almost overwhelming. the Government. The great task of : sure that is exerted on the piston, getting back to normal-pre-war-ex- ral during the induction stroke is nega- Telephone construction, includ- cellence of operation requires the ge tive, and, at most, amounts only toa ing buildings, switchboards, con- reestablishment of an economic Be - pound or two. Hence, the top joint duits, cables and toll lines, must, operating margin capable of taking ad - at a = to do, and, from its inherent nature, be under- care of a larger growth than has ng erelore, the top side of the ring does taken in large units. A metropolitan ever before confronted the Bell of not become so brightly polished as the TRY ee oe Sieg Pe bottom side.—G. F. CoLuins. spar tag? te cue canna ik yas sama sands of parts, may require from ; en two to three years to construct and Construction is being pushed to the Ww Making «= Date ot Pay limit of men and materials; while or every effort is being made to pro- od, Tweezers Only great extension can meet the vide the best, present service. a N first aid calls, when baby has a ist . sliver in his finger, and in other AMERICAN TELEPHONE AND TELEGRAPH COMPANY a similar home surgical cases, as well as AND ASSOCIATED COMPANIES ll in delicate mechanical emergencies a bis pair of tweezers is usually not near One Policy One System Universal Service of ; by and consequently you do the best —— etme you can with makeshift tools. a a ee ae -— E sey practical instrument with Ser Sunde Baga Nonna Re. po heen tempered steel ends can be made from Sena Ge ak eee noma ee sete fs eae $Y seas congener anaes kind in America, illustrating 33 different styles of es Talking Machines and over 500 diferent Phono- all FINGER anaes: a TUOKY 23 PHONOGRAPH COMPANY in- Export Dent. 46G, E. 12th St., N.¥., U.S.A. h- | BECOME A he Soldering a pair of brass plates to a ruling- W Y [= of pen transforms it into a good tweezers R N)» aan n Ks udy At Home. y trained men win 8 an old ruling-pen. A pair of «mat | LO CentsaDay Pays | @@iyisester.. cpu pac Fie brass plates are soldered to the side | for This Symphonola A $3,000 to $10,000 Anaoally 7 members of the pen and the natural | Haima iar wienasratmaMecrit | Ql\6 3 QU we cose ey gar ofa ee se the steel Soe shen into a | "Beautifully Illustrated Symphonola Book FREE Ke. fetun Sandamens Rave ‘aid ot tweezers. Try out this idea | Qo eee eee a evet ca tint ot che. taleet cone, ine Low cost, 2 "a i) and you'll never be at a loss in an Symphonola Records ¢.°.:° Brel, Ogee seundi: Vet erates ieee ee ance + ir -emergency.—M. T P | & EXTENSION UNIVE ‘ ch... ee SETBeNCy.—M. TOCABEN. L8H EE Cs Duk SPSM 1019,, Buffalo,.N. Y. p LASALLE EXTENSION UNIVERSEFY - - 121 een a ae A aE

Page 102

710 ~ -—

HIGH SCHOOL COURSE IN TWO YEARS YOU ARE BADLY if you lack HANDICAPPED HighSchool training. You cannot attain business or social prominence. You are barred from a successful business career, from the leading professions, from well- paid civil service jobs, from teaching and college entrance. In fact, em- ployers of B aieenss 4 all worth-while itions demand High School train- Ba Yon You can’t hope to succeed in the face of this handicap. But you can remove it. Let the American School help you. FIT YOURSELF FOR A This Course, BIG FUTURE which has been fessee. wil by some of America’s leading pro- will broaden your mind, and make Zimphifed and alert and capable. It is compre, and up-to-date. It covers all sub- ro, | given in a resident school and meets all ow aed a High ae hn ay From the first lesson to the last you are carefully examined and coached. USE SPARE TIME ONLY Most people idle away fifty hours a week. Probably you do. Use only one-fifth of your wasted hours for study and you can remove your present handicap within two years. You will y the lessons and the knowledge ag tt wf gain will well repay the time spent YOU RUN NO fe rd Bane 4 you may see for urself how thorough and Complete our | our trainin we invite you to take ten lessons in the fit School Course—or any course of specialized training in the coupon below—before decid- ing whether you wish to continue. If you are not then satisfied, we will refund your money in nar Rot ee ape guarantee satisfaction. asis you Owe it to yourself to make the test. . Check and mail th i mall = coupon NOW for full AMERICAN SCHOOL CORRESPONDENCE Dept. H-757. — Chicago, Illinois

Explain how I can qualify for the position. checked.

. -High-School Graduate ... Lawyer . Electrical Engineer ...Business Manager ..-Elec. Light & PowerSupt. ...Certified Pub. Accountant . ._Hydroelectric Engineer ... Accountant and Auditor ... Telephone Engineer -.. Bookkeeper .. Telegraph Engineer ...Stenographer --. Wireless Operator ...Fire Insurance Expert .. Architect .. Sanitary Engineer ..- Building Contractor ..-Master Plumber ..-Civil Engizieer ... Heating & Vent. Engineer . Structural Engineer ... Automobile Engineer ...-Mechanical Engineer . «. Automobile Repairman ° .. Shop Superintendent ... Airplane Mechanic ...Steam Engineer ...General Education Course .--Draftsman and Designer ...Common School Branches es nn mavkaok Pre ere

A Rifle-Sight Camera View-Finder N the process of cutting down the size on the very small cameras, made especially for reporters and writers, who find it to their ad- vantage to carry a camera constantly, the view-finder is done away with. The manufacturer, however, makes a detachable finder for which he charges anywhere from two to three dollars, and the finder itself is frequently larger than the camera. The finder which I am about to describe has the double advantage of being cheap and is small

The sight-finder is attached to the top of the camera by suction enough to slip readily into the vest pocket. It can be used on all types of cameras. Referring to the drawing, the finder is similar to the peep-sight of a rifle. The subject is sighted throughthetube. The latter is of brass, and is 5% in. in diameter. To find the length, on a piece of paper, draw a line equal in length to a line drawn from one opposite corner to the other of the pic- ture that the camera in question makes. Mark a point above the line, so placed that if a perpendicular were dropped it would cut the line into two equal parts. The distance from the point-to the line should exactly cor- respond to the. focal length of the camera. Now draw two lines, one from each end of the base-line to the point above it. Draw two _ lines

Th... ee | ‘ How the emer 2S , ee finder > e finds the ae OF LENSES ra) The diagram shows the method of determining the length of the tube

parallel to the line corresponding to the focal length, 5/16 in. from it. At the apex draw a line perpendicular to the parallels. The distance between the last perpendicular and the point of intersection of the parallels with either A or B isthe length of the tube. ° At the end of the tube of which the upright comes, glue a piece of card in which has been cut an aperture that is proportional to the size of the. picture. At the opposite end glue a plug with 122

Popular Science Monthly YoSAVED SL i GET OUR Saas SS Me ie . <i DOswxPLUMBING & HEATING 223

Send for our big instructive 256 page well- bound Handy- Man Book Catalog. Every Home Owner, Contractor, Electrician, Farmer, Factory Manager, etc., needs it. Shows over 10,000 Fixtures and Supplies in plumb- ing and heating at wholesale. Shows how to save skilled labor, hard work and unneces- sary material by Our New Cut-to-Fit Method This wonderful book helps you select and install the proper Plumbing, Water Supply Sys- tem, Hot Air, Water or Steam plant. Besides being our Wholesale Catalog it has many practical plans, diagrams, sketches, elevations, etc., showing how to do the work this newer, cut-to- fit way. Any handy man with a few tools can easily do his own installing with the aid of this New Handy-Man Book We have spared no effort and have gone to a great expense to compile this valuable book. With economy still a neces- sity, it would be unpatriotic to send this expensive book broadcast to non-interested parties. Therefore, we request a temporary deposit for each copy of 25c which we refund on first order, or we send our Bargain Bulletin FREE, Address Today Hardin-Lavin Company Y 40 years at * 4526-36-G Cottage Grove Avenue ‘ease $500,000.00 plants behind our guarantee

(ORS Cyaeucwbeel Credir Is Good books you ever looked over ~. <i is our magnificent new Cat- alog, and. the most attractive 1002—$50. features in it are the wonderfully low prices of the marvelously beautiful Diamonds, Watches and Jewerly we now offer you on regular Charge Account, Every manis proud to own a hand- some Diamond—every woman hopes to have one given her. DONT WAIT UNTIL, YOU CAN PAY CASH We Want Your Custom Buy on Charge Account Confidence in the in- We don’t care how much herent honesty of the or little you are worth. American people is the If you pay your bills rock on which our great promptly we should like success is built. We to open a regular Charge don’t ask you to send a Account for you—treat cent. Weship our goods you exactly like our New for free examination. We York City charge custo- pay all transportation mers; accept monthly charges, if forany or jweekly payments, in reason you don’t wish cash or in Liberty Ronds to buy if more convenient. A Genuine Diamond Always Indicates Prosperity Don’t hide your light under abushel, if you are getting on. Let people know it. Opportunities seek out euccesaful me Wear a handsome Diamond ring—or make a gift of one—and you are marked = a man of means and taste. SEND FOR OUR FREE CATALOG You will be detighted with ie choice of beautiful high gate articles it offers you and amazed at our low prices. article guaranteed in writing z tobe 0 = oa fen Quality ona exactly agrepresented. ‘‘/f it NE of the most interesting MI TITITININITITIIITT TIC PITTI LLL wan

ESTABLISHED 1895

Send for catalog nie * FREE. Ask for Edition 58 &

ed

35 Maiden Lane ~ New York

Page 103

MA Sint, Monel oz Fre oc Mme ew chee Co te OO se —_ ‘’ ‘October, 1919 in. hole drilled through its center. Shave the inside edges of the apertures down to a thin edge. The upright rod is 14 by 34 in. It is brazed or soldered to the main tube of the instruments. To the bottom of the rod is fastened, by means of cement and a machine- screw, a shallow rubber cup. : To facilitate speed in making “shots,” have the camera in one vest pocket and the finder in another. To “shoot,” take the camera out with one hand, the finder with the other, lick the rubber cup, stick the finder on the camera, with the large aperture for- ward, and the 1%-in. hole toward your eye. Sight your picture as with a telescope.—ARTHUR KENNEDY. Keeping the Screwdriver from Slipping SCREWDRIVER that slips in the screw slot when pressure is ap- plied is not only a disagreeable tool to work with, SSS but is likely to mar the head of the FILE CROSSWISE a screw and de- tract from the appearance of If the end. of the screw- finished work. driver is roughened by a To prevent stone it will not slip this the first thing is to hold the driver properly, directly in line with the screw. The next is to grind the blade crosswise instead of lengthwise. The little rough- ness left by the stone, running across the blade, gives a sufficient bite in the screw slot to help very considerably. Filing the blade answers the same purpose.—HOWARD GREENE. Preparing a Surface for Painting T is common practice, when we do an odd job of painting around the house, simply to apply the paint with- out thought regarding the foundation surface. It is just as important that the sur- face be in good condition as it is that we select a good grade of paint, for no matter how good the paint, the result will be far from satisfactory if some attention is not given to this very im- portant detail. In the first place, the surface to be painted must be clean, dry, and free from dust, grease and dirt. On new work, a thin coat of shellac should be applied to all knots and sappy places. On work that has been previously painted, use a wire brush to remove all loose particles. Spots that are entirely bare, where the paint has been chipped off, should be given a priming coat of paint reduc- ed with turpentine. The extra labor in thus properly preparing the surface will be more than justified in the durability of the paint and.the’smooth, uniform appearance __of the finished surface, Earned $ 6000 Las 4 a, a ment = x anew rem meee reed mS ORES f — er EE OARS SPREE I ] ERD ER SESE See Stes it Year- Rebuilding Autos! “TI always had a craze for tinkering with motor cars—yet I never thought that I could turn this knack into a good income. Then I opened my eyes to what hundreds of other men were doing. They were buying up old cars and rebuilding them. They were opening up public garages and running repair shops. I made inquiries. I found out how my friends did these things. I followed their example. Last year I earned $6,000. This year I expect to make more. You Can Qualify You can earn as much money as this man. You can turn your love for motor cars into cash. If you are already an automobile mechanic, repair man or chauffeur, you can climb far higher. Right now is the time to act. The field of automobile and commercial car manufactur- ing is growing tremendously. Its future is unlimited. You can prepare yourself speedily to be- come a skilled automobile mechanic. You can equip yourself to open your garage. A simple spare time reading course in Automo- bile Engineering opens the way to success to you—now! Automobile Engineering This six-volume library of Automobile Engineering will prepare you for a worth- while position in the fascinating field of automobile production. Fifteen great automobile engineers and specialists, with the co-operation of scores of other experts in their field, have compiled this great reading course. There are 2,650 pages and 2,100 illustrations. The books are new and up to the minute inevery principle and method. They are carefully cross- indexed so that you can find a given subject as easily as you find a word in the dictionary. Shipped Free We do not ask you to take our word for the merit of these books. We simply ask you to find out for yourself. You can do this with- out risk or expense or obligation. All we ask is that you fill out and mail the coupon. We will ship the books to you express collect for 7 days’ free examination in your home or shop. Use the books as if they be- longed to you. Note how they explain all of the new automobile developments—ignition, starting, lighting, welding, etc. If the books do not come up to your expectations, send them back to us at our expense. If you are pleased with them; if you see that. they will help you to achieve your goal, send us just $2.00 within seven days and then $2.00 a month until the special in- troductory price of $19.80 has been paid. Some of the Fascinating Subj Special Offer | uq. s-- 109 Prints of Your purchase of these ha eg = oe mg ° otors books brings you a Con- | Welding sulting Membership in the | MQQr ..Cp"Rtreic American Technical So- Corburetors “and ciety, which, while valued | valves” Coolin at $12.00, may prove to be pew worth hundreds of dollars | Fly Wheels toyou. Itentitles youto | fur on special information on Final Drive subjects dealing with | pret automobile construction | Tires and repair, or garage or | Igni tion Starting & Light- shop management for the | Sartige & bis! period of a year. .You | Shep Kinks may. ask as many ques- Comepeaes Shep tions as you wish. Equipment - Storage Batteries Send No Money | | ctr e Revair Motorcycles Mail free inspection | Commercial coupon. Just your name and address on the coupon brings the 6 valuable volumes to you express charges collect for 7 days’ free trial. We cannot guarantee that this little price will hold. Your opportunity is now. Mail the coupon at once, while this offer is open to you. The American Technical Society Dept. A207, Chicago, Hl. fee ee ewe eS ee ee | THE AMERICAN TECHNICAL SOCIETY , Dept. A207, CHICAGO, ILL. Please send me the 6-volume set “‘Automo- bile Engineering’’ for 7 days’ free examination, express charges collect. If I decide to buy, I will send $2.00 within 7 days and the balance at $2.00 4 month until $19.80 has been paid. Then you send me & receipt showing that the | $30.00 set of books and the $12.00 consulting membership are mine and fully paid for. If I after the 7 days’ trial I will return them at your expense. oe ee ee ee ee Severe hee wre newer sereereseeee A eialineatianseiincpdleiicccteeiiien think that I can get along without the books a cae ign nme yes Ne aie g Rp I ate AEE ALE EEF:

Page 104

FIT YOURSELF FOR THE BIG JOB Don't hesitate any longer. There is a demand for trained men now than ever i greater 0) opportunities—-bigger pay—more rapid ad- lowe ~e Psouietes that counts now—accurate complete grasp of your trade. Drake’s nc! Books oe HOME STUDY pave the way to the fat pay en- velope. Written in non-technical language that any . Send the price of any book listed books postpaid—you keep a ‘ave days—if not entirely satisfied return the ayeee ees your money will be refunded in full. : AUTOMOBILE BOOKS Brookes itomobile Bere St edi- tion, $39 es, | AUTOMOBILE pocket size. $2.00 IGNITION | jEoRemeCEiEE BS erreres If Leatherette . $2.00 I Bhat bt ts tome | Automobile Start- i and Lighting. By Manly. 1919 “edition. Sa tery size. $1. 50 . aa © Ford Motor ( cae an ick and Trac’ By Mant: bs Leatherette . $1.50 crette "$1.25 ELECTRICAL BOOKS Electric Motors, Direct and Alternating Leatherette $1.50 Wiring Diagrams and Descriptions a ORS Armature and Magnet Winding Leatherette $1.50 Modern Electrical Construction F Leatherette $1.50 STEAM ENGINEERING Swingle’s Handbook for Steam Engineers and Electricians ............. Leather $3.00 Complete Examination Questions and wers for Marine and Stationary ES eae re Leatherette $2.00 RAILWAY BOOKS Locomotive Engineering.......... Leather $3.00 Locomotive Engine iniddators, with Questions and Answers . Leatherette $2.00 First, Second and Third Standard Exam- ination Questions and Answers for motive Firemen....... Leatherette $2.00 SHOP PRACTICE BOOKS Sheet Metal Workers’ Manual. . Leatherette $2.00 Sheet Metal Work and Pattern Draftin iil Oxy Acetylene Welding and Cuttin : Cloth $1.00, Leatherette $1.50 Modern Blacksmithing............ Cloth $1.00 PAINTING BOOKS Scene Painting and Bulletin Art ... cloth $3.00 A Show at Show Cards ............ Cloth $3.00 RIC osx chs O0's'0 0s bauine tee Cloth $3.00 CARPENTRY AND BUILDING Modern Carpentry ........... 2 vols., ‘Cloth $2.00 , The Steel Square............. 2 vols., Cloth $2.00 .. GENERAL RAL INSTRUCTION AND RENCE BOOKS cutetae ‘sey he Cloth $1.00 ' =e Cloth $1.50 Practical Hanibeok | for 1 Milhevighes Cloth $2.00 Just Out! i FRENCH WithoutaTeacher 777 4| SPANISH Withouta Teacher ceri, GERMAN WithoutaT eacher | _ By Professor Phillip m@| Schuyler Allen, Uni- 4m versity of Chicago. % An entirely new } home-study series of %@ modern foreign lan- | Guages.” Simplest, easiest-to- master 4 language method ever 4 devised. } French, Spanish or German, | wae size, oa, $1 5 Drake Books are for Sale at all arte Book Stores. Do not accept Substitates. * Mail the Coupon NOW ‘Order on our five day money back plan. FREDERICK J. DRAKE & CO., ; 1003 Michigan Ave., Chicago, IIl. A Pe hich pl d Enclosed find ($.:. Shon way =| A ). It is agreed that I may return same in 5 if not entirely. satisfed,. and money will be re- EOP P EEA CEMA EE EERE HS SHO REEEE TEES ES SHEE Ee Pereee eer ror) Se eee eee eee Popular Science. M onithly What Can You Do with the Exhaust of a Gasoline Engine? The Popular Science Monthly will pay fifty dollars for the best answer HAT can you do with your engine exhaust? Is it an automobile, boat, or stationary engine? We know of one man who heated his greenhouse with the exhaust from his stationary engine. There are, of course, many other uses for it, and we want to know in how many practical ways it can be applied to save time and money. The appliance - must not retard the engine’s speed or power and must not involve the operating of another engine. “Tell us! THE POPULAR SCIENCE MONTHLY offers three prizes,—a first prize of $50, a second prize of $25, and a third prize of $15, —to be awarded in accordance with the rules set forth below: Rules Governing the Contest (1) Contestants are not limited to the number of methods.of util- izing the exhaust which they may describe, but only one method can possibly win the first prize, only one the second, and only one the third. The contest is open to everybody. (2) The method must be clearly shown 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 pencil sketches will be con- sidered, contestants are request- ed to make their drawings in ink on bristol-board. The views should be sufficient in number to set forth the use of the engine’s exhaust 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 MonrTHLY not later than 5 Pp. M. on Friday, October 31, 1919: (5) The judges of the contest will be the editors of the POPULAR ScIENCE MONTHLY. 124 (6) The first prize of $50 will be awarded to the contestant who, in the opinion of the judges, has suggested the simplest and best method of utilizing the exhaust of a gasoline engine. The second prize of $25 will be paid to the contestant who sub- mits a method next in merit. The third prize of $15 will be paid to the contestant who sub- mits the method third in merit. (7) The winners of the contest will be announced in the earliest possible issue of the POPULAR SCIENCE MontHiy. A descrip- tion of the methods which win the three prizes offered will duly ap- pear 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 manuscripts which do not win a prize. The regular space rates will be paid to the contestants who submit the manuscripts thus selected. (9) When a contestant submits more than one method, the de- scription and drawing by which each is set forth must be sent as a separate unit. (10) Manuscripts or drawings will be returned to contestants if stamps are enclosed. (11) Send drawings and specifi- cations to the Engine Contest ‘Editor, PopULAR SCIENCE MONTHLY, 225 West 39th Street, ‘New York City.

Page 105

October, 1919 This Novel Pen Inker Helps “Keep the Sketch Clean HEN doing very fine lettering and mechanical drawing, it is often necessary to hold the work flat with the left hand. Every time the pen is to be inked, the stopper of the bottle must be removed and the quill touched to the ruling pen. This necessitates the use of the left hand, which interferes with the rapidity of the work and sometimes allows the work to slip, making an untidy job. The illustration shows how the con- trivance works; it is patented and can be bought cheaply. It has a cast-iron base, witha place to hold a standard bottle of me- Place your wrist on the handle and the stopper rises, making the inking easy and clean chanical-drawing ink and an upright on which is hinged a cross arm. One end of the cross arm is shaped similar to the regular ink stopper, and holds a small piece of metal tipped with a closed coil spring. The spring will hold a small quantity of ink, which will run on to the pen when contact is made. The other end of the cross arm is flattened to form a rest. With the pen in hand the wrist is placed upon the rest, which draws the stopper from the bottle. The pen is touched to the spring and inked, and when the wrist is raised, the stopper drops back into the bottle by its own weight.— EDWIN G. GETTINS. A Semaphore Signal to Summon Taxicabs HEN a telephone call, summon- ing a cab, is received in the offices of a taxi company in Illinois, the operator handling the order sets a semaphore on the outside of the building, by means of which a driver is summoned from the regular “stand,” some 300 or 400 feet away. At night the semaphore shows a red light when calls are waiting. This device permits drivers to re- main at their posts, where there is most chance of picking up a fare, and _ at the same time be within a moment’s ~.¢all when they are needed in other $322 $920 & 510-20 eae HOES TH $500 3622 57 You can save money by wearing W.L.Douglas = shoes, the best known shoes in the world. Sold by 106 W.L.Douglas own stores and over 9000 shoe dealers, W. L. Douglas name and the retail price stamped on the bottom guarantees the best shoes in style, com- fort and service that can be produced for the price. Since 1883 W. L. Douglas name and the retail price hasbeen stampedonthebottom of theshoes beforethey leave the factory. The stamped price is never changed; this protects the wearers against unreasonable profits and has saved them millions of dollars on their footwear. CAUTION Insist hav- The stamped price is W.L.Douglas personal guar- ine W. L. Douglas antee that the shoes are always worth the price | shoes withhisname paid for them. The prices are the same every- | and price stam where—they cost no more in San Francisco than they do in New York. W. L. Douglas $7.00 and $8.00 shoes are abso- 1fW.L.Douglasshoes lutely the best shoe values for the money in this cannot be obtained in country. They are the leaders everywhere. W.L. your vicinity, order Douglas $9.00 and $10.00 shoes are made direct from factory throughout of the finest leather the market by mail, Parcel Post affords, with a style endorsed by the leaders of . charges prepaid. America’s fashion centers; they combine qual- Write for Illustrated ity, style and comfort equal to other makes sell- Catalog showing how ing at higher prices. - to order by mail, W. L. Douglas shoes are made by the highest hilo paid, skilled shoemakers, under the direction and supervision of experienced men, all working with an honest determination to make the best shoes for the price that money can buy. BROCKTON, MABS. on the bottom. CVURERAVUNNNUUEOUULUUUUUUAOAUUA ATT Two Lights On One Socket , Make single sockets dou ble workers with re Pye BENJAMIN aa are co. We want every man who shaves to write us for particulars about the Vibrating Electric Razor. No matter where you live, in the city or on the farm, the Electric Safety ‘Razor will solve your shaving troubles. VIBRATING ELECTRIC RAZOR CO. Dept. 137, Omaha, Nebr. '. parts of the. city.—-ORIN CROOKER. «+ TUTE WHITING-ADAMS BRUSHES » Demanded by Master Workmen. Advertised by All Users as the Best. Methods of Construction Render Failure Impossible. Send for Mlustrated Literature JOHN L. WHITING-J. J. ADAMS CO., Boston, U.S.A. Brush Manufacturers for Over 109 Years and the } ste gore ag * World Wy | | | | / |

Page 106

I ever invested. "One pupil says “It's the best money The lessons Tessons would be cheap at doubdle the price. vc Who Wants to Learn Boxing? Would you like to know how to protect yourself against a bully? To be able to outbox someone big- ger than you? To know the 8 most effective blows to use, and the best guards against violent attack, not only against blows, but kicks and wrestling holds? Do you know that you can learn these things easily and ‘quickly by-the new ‘“‘shorthand”’ system of boxing instruction, the Marshall Stillman Method, making. your daily exercise interesting as well as beneficial ? Marshall Stillman teaches boxing by science. By this new method he has taught a novice in ]5 minutes the difficult scientific left hand lead. It often takes 20 lessons to learn it by the old method. In 40 minutes. Marshall Stillman taught 46 new members of the New York State Guard the principles of the hit, guard, and duck. Boxing professors in the Army say that it took them weeks to teach a group those fundamentals by the old method. his.system.is so simple that it is taught by mail. You learn the fundamentals right in front of your own mirror. When yoti face your first opponent. you know how to hit him, what to expect in return, and how to guard against it. Two weeks after re- ceiving it pupils have been able to outbox bigger and stronger opponents. Even boys of 15 have learned to hit and to protect themselves. Men of 50 and 60 have taken it, not only to learn boxing, but for the interesting and beneficial daily exercise. The new complete Home Study Edition is only $5 —less than you would pay for a few lessons by the old method. Besides the 5 “‘shorthand”’ lessons on the hit, guard, duck, feinting, and clinching and footwork with 25 illustrations, it includes one lesson on daily exercise, 8 illustrations; 3 rounds of shadow boxing, 8 bone-breaking holds and releases (Jiu- Jitsu). and. 8 holds in standing wrestling, with 69 illustrations; and a complimentary copy, specially bound for home study, of Mike Donovan's famous book “The Science of Boxing,’’ including. 70 illustrations. Send No Money Fran 7s don't believe bexing can be taught by mail. a vn All right, we'll take you on your own ground —we will mail the complete course to you on 5-day approval pos 5 = coupon co retrk < eileen MARSHALL STILLMAN ASSOCIATION, Suite F-10 No. — Fourth a ~ New York. You } Sal oy g d me on free pro: al your Complete Home Study in Roxing. including 6 SY perecnand”? or Sub- nw ay Say | Lessons, one lesso iy exercise, 3 rounds of s! none releases, 8 holds in standing sera Ae mand a a limentary copy of Mike Donovan’s Book, ‘“The Science of Boxing i er-return the course or remit $5 in full payment within 5 days after its po al.

<I Dae “in ed and farther new en is a cip ity t 4

: air-charnier foam J pone power power, one —-_ ye x Strokes being sufficient.

Works like air-drills and ‘peice mers—with this difference: You control shooting Sesies This block of hardwood shows penetrat- ing power yt each charge, Noother air rifle can duplicate this feat, The Benjamin is safe, because you control the power. Never leooet shooting force—has no springs to get out of order. ot ‘or interesting folder about this wonderful gun. At all dealers, $3.75. Ask _— dealer for demonstra- Beniami: in : orn i Ws

A Funnel Gage that Warns Against Overfilling BTAIN a piece of medium-stiff wire (bailing wire is good) about two inches longer than the top of the funnel. Make an eye in the middle by winding it ° tightly around asmall wire nail one turn. Lay this wire across the fun- nel top, and slightly off cen- ter as measured along the wire —about half the diameter of the funnel tube is right. Then cut the ends just long enough to bend down into hooks which grip the funnel. Take another piece of fairly stiff wire (broom wire, straightened out, will do nicely) two or three inches longer than the whole length of the funnel. -Make a ring on one end to keep it from sliding through the other wire, and drop it down through the eye in the first piece. Now take a cork, small enough to slide down easily through the tube of the funnel, and punch a hole lengthwise through the center of it with a darning needle or awl. Pass the plain end of the broom wire through the cork, from the small end, and trim the cork to a cone shape as shown in the illustration. Set the whole device in the funnel, and adjust the cork on the wire till its top is about one-fourth inch below the bottom of the funnel tube. Cut off the wire below and turn a slight hook in it to prevent the cork from slipping off. As the fluid rises in the receptacle it floats the cork, which raises the wire and warns you when the vessel is nearly full—CHARLES A. PEASE.

No more spilling of valuable fluid: the gage warns you when the receptacle is full Securing a Stud in a Hole with a Sieel Ball ° HE illustration shows an efficient means of securing a stud tightly in a hole A hole is drilled in the end of the stud, with a combination drill, and coun- tersunk. An or- dinary ballbear- ing of a suitable size is dropped pat. intothe hole and = the stud either fa

i, . - Méb

YY yt]

Ny screwed or ham- mered down upon it. As it will be seen, the bottom of the ‘stud will be expanded by. the ball, -holding the stud“ tightly in the hole.—S. B. ROYAL. 126 The stud can’t fail to seat firmly if this device is adapted

Popular Science. Monthly.

Sead Se “a for this Model Aeroplane Book This book tells how you can build and fly “IDEAL” Model Aeroplanes that are true copies— Be an Amateur Aviator! actual, reduced-scale duplicates — of famousAeroplanessuchasthe DeHAVIL- LAND Battle Plane, the famous NC-4 trans-Atlantic Seaplane: and many other well-known and historic machines. They look like the real Aeroplanes and will rise from the ground or water by their own power and fly in the air. You can build one and learn the principles of construc- tion, operation and control. We furnish Complete Construction Outfits contain- ing all parts and full instructions. You put the parts together and build your own Model Aeroplane. Book has 48 pages. Plans for Model Aeroplanes NC-4-50c; DeHavilland Battle Plane-35c; Curtiss Military Tractor, Bleriot Monoplane, Nieuport Monoplane, Taube Mono- plane, Cecil Peoli Racer-25c each. Send for Plans or Bookat once. IDEAL AEROPLANE & SUPPLY COMPANY Established 1911 Cor. West Houston and Wooster Sts. New York City

Makes Any Boy An Amateur Chemist! BOYS—zget 2 CHEMCRAFT outfit and ee perform dozens of amusing, inter- esting and instructive chemical experiments. Surprise your friends with wonderful, mysti- fying tricks of chemical magic. A CHE M- 6. outfit makes any boy an amateur chemist! Each outfit is complete with a large assortment of harmless chemicals, so you can perform every experiment many times; also laboratory apparatus and Manual of Instruc- tion. CHEMCRAFT is correct in principle; made by a professional chemist; used in schools and colleges, and endorsed by’ professors and teachers. A SIZE FOR EVERY BOY No. 1--$1.50 No. 2--$3.00 No. 3--$5.00 No. 4--$10.00 West of Denver, Colo., and in Canada, a Little More. Be sure you gett CHEMCRAFT— it’s the best outfit. Ask for it by namein your Toy Store or Department Store. THE PORTER CHEMICAL COMPANY Hagerstown, Maryland

‘SEX OLOGY by William H. Walling, A.M., M.D. impartsi in.one volume ; Knowledge a Young Man Should Have. Knowledge a Young Husband Should Have. Knowledge a Father Should Have. Knowledge a Father Should Impart to His Son. Medical Knowledge a Husband Should Have. Also includes other kindred subjects. Pee” Allin one votume. Ilustrated.- $2.00 postpaid. & “Write for ‘Other People’s Opinions’’ and Table of Contents. Puritan Pub. Co., .1766 Perry att Philadelphia, Pa. GET ON OUR PAYROLL need _ representatives in every locality. If you area hustier and want to earn more eee we will pay you for part time or whole time. POPULAR SCIENCE MONTHLY, 225 West 39th Street, New York

Page 107

October, 1919 Floor-Layers’ Clamp for Refractory Flooring HE accompanying _ illustration shows, complete and in detail, a yery useful tool for forcing crooked flooring into place, making tight joints and holding the flooring in place while nailing. The block A is made from stock 2 by 5/16 in., the two parts being riveted or, better, welded together. The hole a should allow a 5%-in. rod to turn freely when inserted. The open- ing 6 should allow the lever E, 3 in.

a 22 eS A Ae aT OU roLpep LLU fay . -] rK 20 > Vigan > “ies E 7 FA) hae p 7 > we iPiaetes) ‘sane A hee

Page 108

J outfit to last a year of ordinary use. Don’t Fresh Batteries—Easy to Make In about 2 minutes you can make a better, fresher flashlight battery than you can buy —and you get full life of chemicals. Stronger li light, 25 25% cheaper—400% more service in Make-UR-Own batteries. Fit 11% x61 in. tubular flashlight case. Enough in buy “dead” batteries— make your own. Satisfaction, or money-back guarantee. Renewal Outfit—Parts and chemicals 1. “et to make 6 cells complete............... Marvel Flashlight Outfit—Flash- light case of fibre, heavily nickel trimmed, Mazda lamp, complete with 6-cell Make-UR- : Own battery outfit.. $2. 35 f In ordering, give name and full address plainly written; , mention amount enclosed and which outfitis desired. ¢ | AGENTS WANTED | PROTECTO EXPLOSION BUT OMOBILE WHISTLE A. pleasant, effective warning signal—clear, loud tone. Gets right-of-way in dense traffic— prevents accidents. Replaces priming cup, or furnished with at- tachment for spark plug. Cannot get out of order—no wiring. At- we, tach it yourself in a few minutes. Specify make of car. | $ 50 Order today: $2.50 com- COMPLETE plete. [cents wanreo | The Marvel Co. MrT Make Your Phonograph Build ki “on ith Acmephone eel ee = re duced 5 wa cee S118 8 Full set of Spariiae aete with instruction complete at only Acme Mig. Co., Dept. P1S 140 South Wabash Avenue, CHICAGO, ILL. Raise Belgian Hares for us. Wonderful profits easily made athome. We furnish high grade stock and pay you $7 to $lo a pair and ex- press charges for all you raise. Illastrated catalog and contract Free ITED FOOD & FUR ASSOCIATION 329 West 48th St. Desk 4 New York REE CATALOG fits sto'wonocn s Culcs Either pin illustrated made with any equal Suarart your Sons-Poens On ANY SUBJECT FOR OUR ADVICE. WE REVISE POEMS,COMPOSE MUSIC OF ANY DESCRIP- A Use for the Dash Lamp on the Ford OSSIBLY not one half of the owners of Ford cars ever use the oil lamps that are located on each side of the wind shield. Keeping the lamps filled with oil, lighting them with a match every time you desire to use them, and extinguishing them after the journey is over is very annoying and consumes valuable time. Still, there is a good use for these lamps. It is exasperating to burn out a bulb on a dark night, and it is doubly annoy- ing to find that you have no extra bulb along. The problem has been the carry- ing of these deli- cate articles without breaking them and here is a suggestion that may help. Take a piece of waste or soft paper and wrap up the bulb init. Open the door of the oil lamp and place the bulb within. Here it will ride safely over all bumps, no matter how rough the road, and the bulb is always ready for use when the old one burns out. Two may be carried by using =n lamps.—R. D. GALT. SPARE BULB Wrap the electric bulbs in tissue paper and tuck them away in the dash lamp A Shingle-Marker to Replace the Old Chalk-Line ARPENTERS, when shingling, are obliged to make several trips across their staging to chalk up the line used as a guide for placing the shingles. The little device here shown obviates this. A triangular-shaped piece of wood is made, as shown at A. Two wooden wheels B are : made and bored, part way through, as shownatC, to allow the screw E to set flush. A washer D is put in place and the screw E set so that the wheels revolve freely. A carpenter’s pencil F is put in place at the proper distance and the device is complete. It is operated by placing the wheels against the -heel of the last row of shingles laid and moving the frame along, with the pencil marking as it goes. In this way two or three trips across A shingle-marker that is better than the chalk-line the roof are saved, as a single journey: from end to end of the roof completes “the marking’ process:—- ALBERT E. JONES. 128 ‘Popular Science Monthly Only $j00 and After Trial _ se sharpond ecrlaeand you of esi aera Feo aS a as y balance dy Ag me ‘ew cents acer. rite your own bome be Edison ®.K. BABSON, Edison Phonograph Dist 1367 ne “Saved $1000 On My Diamond” The $85 diamond you sent ably toa rinj recently Basact tat S186 oa ing of $100).—Name on request. This firm nearly 8/4 centu old, rated over $1,000,000.00, lends money on h grade jewelry. Amazing bargains in unpaid loan diamon de. Free examination y Why Pay Full Prices. Prove for yourself that, it’s igansconsery. Send your e fo r wonderful lists free. Every ¥ ewe accurately described in detail. Radically different from catalogs. See these prices before you buy Send for Latest List A Diamond Loans fu, nope an monde far under market be — exami- nation. Amazing _b ns proved by cus- tomers’ letters. Write today. Jos. DeRoy & Seas, 4755 DeRoy Bldg. Opposite P.O. Pittsburgh, Pa. ‘eferences: Dun’s or Bradstreet’e; Harve, N National Bank; U: Pittsburgh. 4 - New wre tox Trumpet Plays in C, Bb, and A This superb Blorite ‘‘Symphony Model Trumpet’’ cannot be equalled for indoor and outdoor work. Just what m:sicians have long wanted. Prove to yourself, in your own home, its superior tone and qua'ity. - Don’t buy acornet or trumpet until Sent on Trial you have tried the Triple-Tone Blorite. Send today for illustrated catalog, just Easy Terms out, of Blorite cornets, trumpets, trom- bones, fites, bugles, drums, etc. SPECIAL LOW INTRODUCTORY PRICES Blorite Instrument House, nace*Stie i. Don’t Wear a Truss Brooks’ Appliance, the modern scientific invention, the wonderful new discovery that relieves rupture, will be sent on trial. No obnoxious springs or pads. MR. C. E. BROOKS Brooks’ Rupture Appliance Has automatic Air Cushions. Binds and draws the broken parts together as_you would a broken limb. No salves. No lies. Durable, cheap. Sent on trial. to prove it. . Protected bv U. S. Cataiog and measure blanks mailed free. name and address today. BROOKS APPLIANCE CO., 255B State St., Marshall, Mich. AGENTS :$60 WEEKLY Robinson Folding Bath Tub. Big Seller. Costs little, no plumbing, 7 little water. Weight 15 pounds, folds into smail roll. Full length baths, far better than tin tubs.. Guaranteed 10 years. $10a day easily made. - Write for free tub offer. ROBINSON CABINET MFG. CO. ‘5052 Factories Building, Toledo, O. patents. Send

Page 109

ra 318] | GEE og , CRIMP curt & LONG BURNING PIPE AND CIGARETTE TOBACCO rer" red bags, tidy red tins, bitin pound and half-pound tin. humidors— and— that classy, practical pound crystal -glass humidor with sponge moistener top that keeps the tobacco in such perfect condition. ‘ R. J. Reynolds Tobacco Co. Winston-Salem, N. C. O use arguing about it, or mak- ing chin-music in a minor key! If you’ve got the jimmy-pipe-notion or cigarette rolling ’em idea cornered in your smokeappetite, slip in a few liberal loads of Prince Albert! And, you'll sign the longest lease you can hook up to on about the cheerfulest brand of in-and-out-door sport that ever did ramble up Broadway or down Lost Creek trail ! Boiled down to regular old be- tween-us-man-talk, Prince Albert kicks the “‘pip’”’ right out of a pipe! Puts pipe pleasure into the 24-hours-a-day joy’us class! Gives smokers more fun to the square Copyright 1919 by R. J. Reynolds ‘Tobacco Co Oe ke inch than they, or you, ever dug out of a pipe before | Prince Albert “makes a pipe or cigarette a peace party at both ends and the middle! Just -hums and hums the soothingest symphony of smoke content that ever sified its happy way into a man’s system ! P. A. is so fragrant, so fascinating in flavor, so refreshing ! And, you run plumb-fair. against the. astounding fact that Prince Albert can’t bite your tongue or parch your throat! Because, our exclusive patented process cuts out bite and parch! Why, you can’t get orders in fast enough to try to buy up the supply for a long, long spell !

Page 110

SURGEON ‘Make $2,500 to $4,000 Per Year Giving New Life to Old Tires A Haywood Tire Sur- geon can do more with old tires than was even dream- ed before the war. By the Haywood Method a Haywood Tire Surgeon can give 4,000 to 5,000 more miles of new life to a tire that two years ago would have been thrown on the junk pile. And it’s easy to learn. Stations are Needed Everywhere 20,000,000 tires wearing down every day. By Tire Surgery you can quickly repair, rebuild and give new life to tires seemingly all worn out. Cuts, gashes, tears, bruises, broken fabric, every kind of an accident that can happen to any tire, inside or out, you can repair and save for long service. The chance to make money is simply wonderful. $2,500 to $4,000 a Year is Possible If we told you all the truth you’wouldn’t believe it. You would say, “it is too good to be true.” But you can see what a great field there is for Haywood Tire Surgery Stations—for this better way. Send Today for My Free Book ry ready to 9 vo tne a et your request, a fascinati eet about tires—how torepair them by the Hay- ‘™, wood Method—how to M. HAYWOOD, President start in business—how e HAYWOOD TIRE & EQUIPMENT CO. % to build up trade— == Four Months This is Richard A. Oldham Mr. Oldham was telegraph operator for the Illinois Central Railroad for twenty — Heis pee years old. Oneday read one of my advertisements and the ibilities of making money in Auto Tire urgery business. In a few weeks he had purchased and installed a Haywood outfit. AAS was pA cama Two and One-Half years as Telegraph Operato’ 78 an send me er your Syed ee et en : Please send me by return m e whole proposition ri hon the new Haywood Tire Surgery ethod@ in front of you. Use and the details of your free school of tire repairing. ~~. | at en left, e eo tray , Pres. % Haywood Tire & | Name eh ¢@, Equipment Co. %% 794 Capitol Ave. Address ©, indianapolis % Indiana erences will send you my book “Promotion and Conservation of Health, Strength It is for your interest and welfare. 1067 Strongfort | QUIT! Big Profits Every Month in Pills, !axatives,saline waters and purgatives will not cure that constipated habit—you Ought to know it by this time. Besensible —you have been whipping your bowels shamelessly into action, and weakening Garages Use HB Chargers—Note Their Profits their natural functioning more and more. not digest well—you lack stamina—you are hervous, listless, lack ambition—have no ehergy—no vitality—you are failing in manhood—it’s all your Own fault. No matter = your rn or — " = under my method of~ physical an to$1.50. B } Health upbuilding knownas . a tn recente =~. Ty 0 ice. Easy to install an STRONGFEORTISM electrical knowledge required Bin # you can be restored in vigor ahd vitality ‘and this ad to your letterhead and mail | be entirely free from constipation or any other TODAY for information. ailment or disorder let it be what it-may— HOBART BROTHERS COMPANY i) whether you suffer from early excesses, induced Box $102 Troy, Ohio by pernicious habits. or whether losses weaken Succesaful Manufacturers Since 1898 i} you, or you feel your vitality waning—Strong- . j fortism will restore, rejuvenate. Send’ three YOU Can Do As Well with This HB 500 Watt Charger cash pay t, bala monthly terms. HB Absolute ‘Monsy-ace juarantee. Recharges 1 to 8 6-volt batterk ies for 10c to 15¢ each, customer pays 75c a Battery Charging These Keifer Auto Supply Co., Kelter, Okla. (pop. 1200)—**My aver- am- Now you are full of ailmen your system age smcoune per month is $165.00 The chargerisO, K.”’ H is upset—your blood is poisoned—you are month $200. to $40.00. Covt permmonth sie to $800 The meet sluggish and dull witted—your food will complete and best machine one can buy. Not amoment’s trouble. 2c stamps to cover mailing expenses, and I and Mental Energy.”” Read this book. prepares and-sends Free, ; teachers’ Le LIONEL STRONGFORT Physi: and Health Specialist fodtate “e ; Newark, N. J. write to FREE SERVICE TO TEACHERS 2 .2Stisnee arStensny Service Sheets each month to tus be your Liaison Office bet ween the classroom and real life: There is no cost to you for this service: If vou want to put a real ““Punch’’ into your classroom work opular Science Monthly, 225 W. 39th St., N. Y. What 15° src. You ‘te Nation's Capital je matter of 2S¢ in stamps or coin will bring you e Pathfinder canter of chilis oe tae ° ST ag 13 weeks on trial. The’Pathfinder is an illustrated weekly, published at nerve this id The Pathfinder’. the Nation’s center, for the Nation{ a paper that prints all the news ofthe ill ly ap ake pA ger meng wll world and tellsthe truth and only the truth ; now in its 26th year, This pa- lustrated weekly re — Of public aff fairs per fills the bill without emptying the purse; it costs but $1 a year. If you correct diagnosis : want to keep posted on what is going onin the world, at the leastexpense t epoch - making ys. of time or money, this is your means. Ifyou wanta paperin your home which is sincere, reliable, entertaining, whol the Pathfinderis yours. Ifyou would appreciate a paper which puts everything clearly, fairly, briefiv—here itis. Send 4Se to showthat you might like sucha paper, and we will send the Pathfinder on probation 13 weeks. The 15c does not repay us, but we are glad toinvestin new friends, The »Box 23 , Washington, D.C. 130 Popular Science M onthly Removing Sediment from Storage Battery Cells AVING been in rather severe gery. ice for four years, the cells in the storage battery of the Johns Hopkins University reached a condition where a thorough cleaning was necessary, Active material had fallen from the plates into the bottom of the jars An effective scheme for cleaning a stor- age battery without taking out of service until it was within a little of the plate bottom. There were 130 cells in the set, each of 400-amp. hr. rating. The jars were of glass and measured 12 ins. square and 16 ins. high. How to re- move the old active material from the bottom of the cells was an awkward problem. To dismantle the cells, take them down and wash out the sediment was out of the question, for; aside from the risk of breaking the jars, expense of new separators, etc., the battery could not be taken from its work. An attempt: was made to suck up the sediment using. a‘rubber pump and a long suction pipe. This worked but it was too slow and finally the pump broke. Other schemes were used but the one that finally worked is best: de- scribed with the aid of the illustration. The apparatus consisted of a filter pump, a 5-gal. (19-1) bottle, a Z- shaped glass tube and a length of rubber tubing. Any other type of exhaust pump can. be used satisfac- torily to produce the vacuum, if desired. The water was turned on at the filter pump, causing a partial vacuum in the bottle. By inserting the glass tube in the battery jar the sediment was drawn up. As the process went on the end of the glass tube was moved about over the bottom of the jar and all the sediment was thus removed.

Page 111

ins ore che ars ate | ich | ars ns. | re- the ard ike ent om nse Pry the um ass ent ent ved ind ed.

October, 1919 Of course, the acid level in the jar was lowered during the cleaning process, put as the cells were not in service while the battery was being worked upon this made little difference. They were refilled with electrolyte before heating could take place. The mixture taken from the cells was emptied into a spare battery jar and allowed to settle. The clear electrolyte was siphoned off and used for refilling the jars. The time required for each cell was exactly half an hour. Six or eight cells were cleaned per day, according to the time available-—M. W. PULLEN. A Sprinkler Attachment for Garden Irrigation N slow and continuous irrigation of garden plots, which is preferable and more effective in producing sure and «steady growth to spasmodic waterings, trouble has always arisen because the gasket in the pipe or hose line soon wears out and the pressure varies so that results are uncertain without constant watching. Here is a way. to prevent this trouble. ' The device, which is easily made by anyone, consists of a large but short copper rivet: with a 1/16-in. hole punched or drilled through it length- | wise, and two ordinary rubber washers, one to be fitted over the head of the rivet and the other under it in the coupling. : Washers hold the rivet in place and prevent leakage when the hose is attached to the hydrant and the joint screwed tight. The faucet may be turned on full and the pressure is relieved from the gasket and hose. The stream is distributed with a 3/8- in. pipe, 10 ft. or more in length, with a 1/16-in. hole in it every 2 ft. At one end this pipe is fitted with a

The washers hold the rivet in place and prevent any leakage at this point reducer and coupling to connect with the hose, and the other is capped. There will be no variation in the streams that come from the holes in the pipe, they are not strong enough to cause soil erosion, and the pipe may be placed wherever desired, with the water running. This size Stream cannot injure the plants even though the water may be turned on full—JoHN L. VON BLON.

GiveYourPau Envelope nce to Vrow "Thee! books will turn the trick for you. They

have helped thousands of pay envelopes to grow big and fat and will do the same for yours, making it possible for you to get some of the good things in life you can’t get on a small income. You get paid for what you do and that depends on what you know. If you know more you can earn more and these books will give you everything you need know to get the pay you would like to have. » They are written in plain, everyday language—so clear that the beginner can understand them—so thorough and complete that a veteran worker will wonder how he ever got along without them. Hundreds of pictures, diagrams, etc., in each volume make difficult things as simple asA B c The fine, hard-wearing bindings stamped, in gold will last a lifetime. To You a Week FREE Just so you can see for yourself what wonderful books these are and how they will help you in your work we will lend you any set for a whole week FREE. Pick out your set now from the list below and mail the coupon today. Carpentry and Contracting, 5 volumes, 2138 pages, 1000 pic- CHL, = Waa Sao on aos oan chavs ocewet auemn oe ow $17.80 Civil qe 9 volumes, 3900 pages, 3000 pictures. Was Ear e cine sg & daiaertve kk Wu's Sates its ....Now 21.80 Law and Practice (with readingc 13 vol 6000 . oo illustrated. Wenn res ate ‘i aoa to icycemge ¢ iki 7” 39.80 Telephony and Selearenhy 4 volumes, 1728 pa: 2000. oe tures, Was $20.00....... cag eeren eRe: <8. - ges, Reais pie 12.80 Sanitation, Heating and Ventilating, 4 volumes, 1454 pa pon Hecture|s: WAS SHO.00. 2... SF cic ccaWevtemechecdr 13.80 Practical Accounting, 4 vol , 1840 800 pictures, a. Was $20.00....... Fe eee a: srs tiene ores Now 12.80 Ones SF sbie svete cccccccncnsaagunpecses denau une Now 13.80 Send No Money! [Expert You don’t need one cent to get any of these books Ady ce to use for a week. Just send the coupon without FRE E y money and we will send the set you select by ex- iteentgremntiv ile press collect. Look through them carefully—read | coupon entitles you something in each volume—show them to your | %3$!2.00consulting friends and send them back at our expenseif you want to. If | American echnicai you want to keep the books to help boost your pay coveere Society — ling to a size where it wil buy you some of the luxuries of li eee at ony me send us only $2.00. You can send the balance of the special ssolens Le reduced price the same way—$2.00 each month (50c a week). (! = AMERICAN VECHINGAL SOCIETY, Dept. X-207, be -e tninels, & U.S. A. _ sungeseq gf {echnical | ; ¢ Winpept, «CHUMP ? HE eb 1 F of 'e ilinois, U. S$. Ac bi (rep) PF Send mea set Of vvssrcesennseseumesen M NGINEERIN( CRARERING 6) i eo ; for eee Ey @ seven days’ free use, together with a & consulting membership in your Society. I will conmns the books thoroughly 2] i

CAS ENGIKES t ¢ at the end of one week will —z aye my : SINE: them at your expense or send you $2. on ae AG first payment ond $2.00 each month neil g A ikcasesnsentiets Meaaieanionn® has been paid. Then you will a o send me a receipt showing the books are mine and & fully paid for.

¢ PLEASE FULL IN ALL THREE LINES | T_T.

i

Page 112

= iat a nn 2 : ‘ For the Radio Experimenter Popular Science Monthly q HE art of radio com- munica- tion owes a great deal of its recent remarkable de- What the Germans think is high class in a vacuum tube. This one was cap- tured aboard a velopment to the German submarine thermionic vacu- um tube. This device is capable of per- The Thermionic Detector By H. J. van der Bijl, M.A., Ph. D. E following is probably the most complete and thorough-going popular exposition of the theory of that interesting new piece of apparatus, the thermionic detector, or vacuum valve, which has yet appeared. It follows up the historical article which appeared in the August POPULAR SCIENCE MONTHLY. physicist and engineer of much experience, specializing in thermionic detectors and related apparatus for several years, especially during the war. a number of papers in the Proceedings of the Institute of Radio Engineers and in several other purely professional journals, all of high standing. Each of these papers, however, is full of calculus and other mathematics, hard for all but the initiated to follow. Knowing the interest on the part of amateurs‘at this time in vacuum tubes, we asked Dr. van der Bijl to set down in a more easily understood and popular way some of the things he knows. A second instalment, relating to the practical manipulation of thermionic detectors, will appear in an early numbet.—EDITOR. experimenter will realize the growing need of a working knowledge of the thermionic tube. This knowledge can be acquired without much trouble by those who know something of the behavior of electrons and are ac- quainted with some of the fundamental principles underlying electric wave phenomena. The man who under- Dr. van der Bijl is a research He is the author of He has produced an unusual article. An American vacuum tube. A dozen or more different kinds are produced in the United States. Most are distinguished for compactness, accur- ately worked-out characteristics, and dependable operation by a wire and passed through the coils of a telephone receiver. If the fre- quency of a current passing through a receiver lies within the audible range, the receiver gives a tone, because the diaphragm is attracted by the electro- magnet so many times a second. But the waves used in radio work are of such a high frequency that they cannot be heard at all. Now forming a large number of functions. Itcan amplify telephonic cur- rents with great precision, detect high - frequency electrical oscillations and | make them audible, and produce oscillations or “sing’”’ at almost any de- sired frequency. While it operates with facility over a wide range of fre- quencies (its present sing- ing register ranges from a fraction of a cycle per second to several million cycles per_second), the range of power that it can handle is no less remark- able, considering that it detects oscillations the suppose we chop off all the lower halves of the waves shown in Fig. 1, so that we have some- thing like that shown in Fig. 2. There will then be a succession of current rushes through the receiver always in the same direction. The intensity of these current rushes, occurring, say, every hundred _ thou- sandth of a second, in- creases rapidly and then dies out. If this process recurs every thousandth of a second, the effect on, the receiver is the same as if a current like that shown in Fig. 3 passes power of which is a small fraction of a watt, and can be made to produce oscillations representing a power of a thousand watts and more. In practically all radio receiving sets , in use at the present time, the crystal Train of oscillations received by antenna M,N, Af, NV) AVM FIG.2 Oscillations after passing through rectifier Seer S\N S\ S\ FIGS Audio frequency current in telephone receiver Curves demonstrating fundamental action of crystal detector. Complete story is shown detector has been superseded by the ‘thermionic detector, which is more “sensitive. As time goes on, the radio % Telephoning to a plane high in the air—one use for ther- mionic detectors, or vacuum valves. the airplane permits the aviator to hear and answer stands how and why the thermionic tube operates the way it does will be able to operate his tube under the best conditions and get the most out of it. Let us, therefore, briefly consider some of the fundamental principles involved in the study of this tube. Crystal Detector Acts as Rectifier The crystal detector can detect electrical oscillations because it acts as a rectifier; that is, it transmits current readily in one direction, but practically none in the other. Fig. 1 shows a train of electrical waves such as is obtained from a source of continuous oscillations and interrupted at definite intervals. Suppose these waves be picked up 132 A similar set on through the receiver a thousand times a second, and the receiver pro- duces an audible tone. This chopping off of the waves is what the crystal detector does. The early type of thermionic valve of J.-A. Fleming can also be made to detect in this way, and in the early days was so used. But it has other characteristics which enable it to be used in a different way. This valve much resembles an incandescent lamp. But, besides the filament,: it contains a plate which sometimes takes the form of a metallic cylinder surrounding the filament and sometimes is in the form of a plate or pair of plates. The discovery was made by Edison in 1883 that if the positive end of the filament of an incandescent lamp is connected through a galvanometer to a plate in the bulb a current is ob- served to flow through the galvanom-

Page 113

vill gh u- October, 1919 ut when the plate is connected “4 . negative end of the filament there is little or no current. The same effect can be observed with the circuit shown in Fig. 4. Here the pattery E; heats the filament, and the current between filament and plate is driven by battery Ep. This current is observed to flow when the plate is itive with respect to the filament pos : even in the highest attainable vacuum, Rear view of right-hand part of radiotelephone set shown on page 132. Notice how the valves are mounted and is carried by electrons emitted from the filament when it is hot. In order to operate a thermionic tube satisfactorily it is necessary to know how, why, and under what condition the electrons can be boiled out of the filament. Relation Between Electrons and Atoms The atoms of all substances consist of a number of electrons held together by positive nuclei. The difference in the various elements consists in the number and arrangement of the elec- trons and positive nuclei. Metals be- have as if they have a large number of electrons that are free to move between the atoms, and therefore they are good conductors of electricity, because if a potential difference be applied between the ends of a bar of the metal the electrons move in the direction of the electric field and so con- stitute a current. Although these electrons are free = to move between the atoms of the metal, they can- not escape from req GAvANOMETER it at ordinary Showing the prin. t@mperatures ciple of Edison’s vac- because they are uum valve discovery constantly pulled back as soon as they try to reach beyond the surface of the metal. The force tending to pull them back is sufficiently strong to do 80, except when the electrons do not shoot out from the surface with a very high velocity. If their velocity ex- ceeds a certain amount the force fails to hold them within the substance and they escape. fa ee +o ee 7 tion Fleming Pat. No. 803684 De Forest Pat. Nos. 841387-879532 Class I.—Designed for use as a detector; operates with plate potential of 20 to 60 volts. Class II.—Designed for use as an amplifier; plate potentials from 60 to 110 volts may be applied. Tubes in either class may be used for detection or amplifica- tion, but those of Class I are best as detectors, and Class II tubes are superior as amplifie-s. Room 1868, Woolworth Building Schofield Bldg., Cleveland, Ohio American Bldg., Baltimore, Md. Insurance Exch. Bldg., San Francisco, Cal. Standard Resistance, Complete $1.00 THE HEART or tae WIRELESS An Amateur Station Without a Vacuum Tube Is Years Behind the Times MARCONIV.T. $7.22 each Under agreements recently effected the Marconi V. T. is the only vacuum tube, or audion, which may be sold to ama- teurs, laboratories, schools of instruc- and experimenters. The approximate operat- ing life of the MARCONI V. T. is 1,500 hours. The Marconi Resist- ance, connected in the cir- cuit between the grid and the filament of the Marconi V. T., is made in the fol- lowing standard sizes: 4 megohm, 1 megohm, 2 megohms, 4 megohms, 6 megohms. Resistances of any special fractional values up to 6 meg- ohms can be supplied. Send all remittances with order to COMMERCIAL DEPARTMENT MARCONI WIRELESS TELEGRAPH CO. OF AMERICA Sole Distributors for De Forest Radio Telephone & Telegraph Co. - = 233 BROADWAY, NEW YORK BRANCH OFFICES: 136 Federal St., Boston, Mass. 301 Commercial Bank Annex, New Orleans, La.’ 109 South 2nd St., Philadelphia, Pa.

Page 114

— = cetioes ee Early Training i in Transportation ‘Running a real -railroad and man- aging a fleet of ships is a man’s job. But Ives Toys—trains. ‘and boats— enable a boy’ ‘to be everything from section hand: to president on his own railroad and: from engineer to. fleet commander over his own boats. Ives Toys broaden the boy as he plays: He uses his ingenuity and thinks for himself as he learns the fundamentals of transportation. The self-reliance he acquires while playing with Ives Toys helps him in later life, whatever his vocation. $I" & Ives Trains—electrical and mechan- ical—are sturdily constructed to with- stand boyish abuse. They whiz on the straight-away and whirl around curves, take switches and pass cross- ings without leaving the track. With bridges, stations, semaphores, sidings, culverts, tunnels and other acces- sories, any boy can plan, build and operate a’ complete miniature rail- way system. Ives Boats are Ives latest develop- ment. Made of steel, watertight, screw propeller driven by powerful clockwork motor speeds the perfectly balanced craft through the water for long distances at a single winding. Twelve models and sizes to choose from. Good toy stores and toy departments everywhere sell genuine Ives Toys. The name ison every one. Send 4c. in stamps for either our booklet on boats or folder on trains; both for 6c. The boat book contains rules of the roadway, signals, nautical glossary and other comprehen- Sive navigation information. The Ives Mfg. Corporation 191 Holland Avenue Bridgeport, Conn. . ‘fromthe substance?’ these two ex- ‘There is one ve- locity, which is ‘Now, -how can:we give the elec- trons sufficient velocity to get away These electrons, like atoms, are in-a state of constant motion; and they: move around with a wide range of velocities; which con- . stantly. change on account of. the collisions of the.electrons with one another and with the eomes of the substance. At any instant a few electrons’ will move with .very high velocities, a few others ~ will move with very low , velocities, and the rest will possess velocities ranging between treme values. ‘shared by more electrons than any other. This is the most prob- able velocity, and when we talk of the ‘“‘velocity of the electrons’’ we shall in general mean this value. Now, the ve- locity of the elec- trons depends upon the tem- perature of the substance. At ordinary temper- atures the veloc- ity is so small that practically no electrons can escape from the substance. But we can easily enable them to do so by heating the substance to a high temperature. Thus a tung- sten filament at the temperature it has in an incandescent lamp, or higher, is hot enough to boil out large numbers of electrons. Suppose we heat the filament in Fig. 4 to such ®, a temperatyre. Then, on ac- count of the 6; potential differ- A T3 T2 3 4 ence between 3 I i, the filament 9 ' and the plate, é : the emitted ° ha iv electrons are FILAMENT~PLATE. VOLTAGE pulled over to the plate and a current flows through the circuit. The electrons, of course, flow in a FIGS Peculiarities of current conduction through simple 2-electrode tube direction that is. opposite tothe gen- | erally. assumed direction of current. The peculiarity of the current ‘con- duction through such a tube is that the current does not increase linearly-with the applied voltage, as it- does in the case of conduction through a wire. While the voltage between filament and plate is small, the current at first 134 An English vacuum valve. increases slowly, and then gradually more rapidly as the voltage ‘is: in. . Popular Science Monthly - F Bb } creased, until finally it does not in. .; crease in any marked way, no matter how high the voltage is made. These phenomena are represented by~ the curve :OA,B, in Fig. 5. represented by the magnitude VB, is ; oe } The current » therefore very nearly the maximum z current that can. - the tube when the filament is at a’ temperature | T),” crease this cur- rent by raising the filament toa higher tempera- would increase the velocity of the electrons and more would es- ment. At a fila- ment temperature Ts. we then obtain a _ characteristic OA>2Bo. current that can be passed through the tube is called the saturation current, and is obtained when the electrons are pulled away to the plate just as fast as they are Haste and tush of the war necessitated rough construction. Later valves areimproved filament. all the electrons that are boiled out of the filament. Crowding thes Boe with Electrons What happens pulled over to the plate byithe applied potential ae between filament and plate? ], they go right back to the.. filament, when they are not needed.. Of course,; they! come out again,. and so there ig a continual movement back, ‘and forth;;while at the same time some of the-electrons are continually being carried-away by the applied electric field. It might seem strange ..thatsome..electrons should suddenly. change their minds and re- turn to the filament: ‘The reason for this is. that,electrons, being negative electric; charges, always..repel each other, and. they get so badly crowded in the space around the filament that some are driven back to it. This crowding .of the space with electrons accounts for the peculiar shape of the curve OA. If just a few | electrons came out of the filament they would easily move across to the plate; but when they come out in big crowds it is necessary to apply a voltage be- cape from the fila- | The maximum _ emitted from the. From. this it follows im-: mediately that when the voltage is” not high enough to give the saturation | current, then we do not make use. of: to. thosé that are not’ be obtained from , But we can in-- | ture, because this‘ —

Page 115

October, 1919 Seca: SORE ORRIN ANN AA RR TAR TS ad SS > 1 at a “| SO amin v4 Agee po AZ a } ‘ y Cite * if : aN g FI | N TRADE Man (| ~ é \ DELICIOUS and REFRESHING rr) 7 he am : Coca-Cola is a_ perfect ; answer to thirst that no 3 imitation can satisfy. Coca-Cola quality, recorded in “3 the public taste, is what holds it x above imitations. Demand the genuine by full name— nicknames encourage substitution. THE COCA-COLA CO. ATLANTA, GA. ct ct A ct bch | weal poet tRe NS SP ct rem OD "St ee OD OD DO SLO NO NS I a ee 135

Page 116

SAVE 40” cLoTHING A money saving opportunity that you should in- vestigate at‘once. We make and sell the finest made- to-measure clothes direct to wearer at a guaranteed saving of from 25% to 40%. We cut out all middlemen, save all unneces- sary and Y, profits, and give you the benefit.

i fie ti 1 We make every suit to your exact. measure and individual specifications, send it to you delivery charges prepaid, let you try it, and inspect it carefully. Unless you are perfectly satisfied you will not be under the slightest obligation to keep it and your order will not cost you one cent LOOK AT THESE LOW PRICES (A Few of Gur Bargains) sual R’t’l Our Wh’le Price Price Kind of Cloth ic Fine bine Worsted - - = = «= $35.00 $22.00 Gray Cussimere - - - = = = 32.00 20.00 Fine BlueSerge- - - = = = 50.00 35.00 Brown Check Worsted - - <= <- = 40.00 29.50 Steel Gray Worsted - - <= = 32.50 And - 45.00 STYLE BOOK AND £-p cLorn samenes FREE Write at once for copy of our new style book showing the latest New York and Chicago fashions with a beautiful variety of la cloth renee the enaass 2 eee peputer a, Sirocons, for measur: . ree an 1s and no ations to you. Bell ‘Tailoring is paces Bo in qual ty, fit and style. Nothing e oO

better made and remember we guarantee a saving of 257, to 40%. matter where you live, write at once for your copy of our new book. THE BELL TAILORS _.,f9253 22°22" Finois The Latest in Amplifier Design Sufficient to Give Amplification Up to 100 Times Panel quickly re- movable, making all parts acces- sible, and the re- placing of the new .. type en block “B” ~ batteries but a moment’s work Workmanship of the highest grade Price, without the bulbs $69.50 DE FOREST RADIO TEL. & TEL. CO. 1391 Sedgwick Avenue New York City

“ASK ANYONE WHO HAS USED IT” . Brandes Wireless Headset TRI AL Brandes Wireless Headset sent to OFFER you on trial for 10 days. If, for any reason, you are dissatis- fied, your money back without a question. Test it—compare with others—for sensitiveness, , clearness, distance. Prove for yourself the fine quality, the “matched tone.’’ Thetwodia- ¢ phrams, toned exactly alike , strengthen the signals and pre vent blurring. Used by many U.8. Gov't experts and experts abroad; by colleges and tech- nical schools; and by profes- d amateurs every- Pg a . **Superior’’ Set $6

Send 4c for Cetalogue R 2000 ohms BRANDES, 32 Uni Room 818, New Y. E S let eue he r Spectarists re ©

LEARN TELEGRAPHY.. at home in shortect ~«ssthle time, “arse or Wire! OMNIGRAPH AUTO- MATIC TRANSMITTER, connected with Sounder or Buzzer, sends you ry messages at any speed, just as ex- at ye would. Adopted by . 8. Govt. 6 styles. Catalog free. OMNIGRAPH MFG. CO. 39-H Cortlandt St., New York

tle

tween plate and filament to get them across. A few personsrunning down a quiet street can go at a pretty good speed; but when the street is full of people .trying to see a parade, the police can’t make them go fast enough. The same illustration applies to elec- trons. Increasing the number of peo- ple would not make them move any faster. This is true also of electrons in the thermionic tube. Suppose we apply a voltage equal to OV; between the plate and filament (Fig. 5), then the current is given by V,A;. This is a measure of the num- ‘ber of electrons that this voltage can pull over to the plate per sec- ond. And we see that this number is the same, no matter how many more electrons we boil out of the filament by rais- ing its tempera- ture. The only condition is that the temperature of the filament must not -be ap- preciably less than that corresponding to T,. If the temperature is equal to or greater than T,, the space between the fila- ment and plate is crowded as full of electrons as it can be. Of course, we can drive more electrons across the space by increasing the driving force; that is, we can increase the current by increasing the voltage. The fact that electrons behave somewhat like a crowd of people is in many respects a great disadvan-

Fig. 6—A modern vacuum velve of typical three elec- trode construction Popular Science Monthly shown in Fig. 6, in which two flat. plates are placed on either side of the filament and two grids intermediate - between the filaments and the plates The pairs of ‘ plates and WF grids are each connected me-

E6<O FILAMENT PLATE

tallically, to 5 act like one 4 f plate and one When grid potential is negative grid. The insertion " | XE of the grid or controlling %° aS electrodeinthe “ ”s valvewasastep -—2 ee When grid potential is zero of tremendous

practical im- + {yz portance. The a grid makes it 2+ 9 possibleforthe 3 8 tubetoperform _o fz a great variety "65 — fe: of functions. When grid potential is positive The character- istics of the tube can be obtained with a circuit like that shown in Fig. 7. It will be seen that there are really two circuits: the input circuit, connecting the grid to the filament; and the output circuit, connecting the plate to the filament. The battery E, keeps the plate posi- tive with respect to the filament, and drives the electrons emitted from the filament across the space to the plate. The number of electrons passing to the plate can be controlled by poten- tial variations applied to the grid. The grid acts like a partial screen to the electron flow. But the screening action depends GRID not so much upon What happens when grid potential is altered. Looking down on cross-section of the grid, plate, and filament

tage. One reason is that it requires an expenditure of energy to get them across the space; another is that the crowding causes the char- acteristic to be figz _ FILAMENT INPUT Eg CIRCUIT —alalale

the interposition of the wires in the path of the elec- trons as upon the attracting and re- pelling effect of curpur the grid due tothe CIRCUIT positive or nega- + , tive potential ap-

curved. When ‘ using the tube as an amplifier it is desirable to have a straight characteristic. On the other hand, when using it as a detector we should like to have it curve as much as possible, because in this case we actually make use of the curvature of the characteristic. valve. Controlling the Electron Before showing how this can be done, let us first explain a much better way of pulling the electrons across, and of controlling the number that can pass to the plate persecond. This can be done by inserting a third electrode in-the form of-.a sievelike electrode or grid between the filament and the plate, as was done by De Forest in his “audion.” <A three-electrode tube is 136 How to obtain the tics of the three-electrode vacuum The apparatus used is simple plied to it. The effect of the grid can be exempli- fied by the lines of force diagram shown in Fig. 8. characteris- Two Examples Let us suppose that the negative end of the filament is connected to ground and the plate maintained at a positive potential by means of the battery E,. Then a certain number of lines of force issue from the plate. Now, if the battery E, be zero for the present, that is, if the grid be directly connected to the filament, then there can be no lines of force directly between filament and grid. The distribution of the lines of force is then that shown by the central diagram. It is seen that the electric field, due to the potential on the plate, reaches

Page 117

d d e ei rrRee WY ct DO DO. we October, 1919 h the grid and manifests itself ee filament and grid, and that therefore some electrons will be pulled to the plate through the openings of the grid, but not so many as would be the case if the grid were removed. If now we make the grid somewhat positive with re- spect to the fila- aa / ment by means of the battery E,, the electric field between filament eer and grid will be iit, increased; there are more lines of force in that re- gion, as is shown by the lower dia- gram Fig 8. The result is that more electrons will be pulled over to the plate per second and the current increases. If, on the other hand, the grid be made negative with respect to the filament, it tends to repel some of the electrons and the current to the plate decreases. It can be still further de- creased by making the grid still more negative; and by making the grid sufficiently negative we can stop the flow of electrons to the plate al- together. It will be seen, then, that the current to the plate can be varied by simply varying the potential of the grid, even though the potential of the plate remains constant. It is important to note that when the grid is negative it tends to repel the electrons that are emitted from the filament, while the plate, being posi- tive, tends to pull the electrons away from the filament. As long as the repulsion of the electrons by the grid is not greater than or equal to the attraction due to the plate, electrons will pass to the plate and a current will flow through the tube. But, since the grid is negative, the electrons will all go to the plate and none to the grid. This is the same as saying that the resistance of the input circuit is in- finite—it is an open circuit. If, on the other hand, the grid has a positive potential with respect to the filament, some of the electrons emitted from the filament will actually be pulled over to the grid, and a current will flow in the input circuit as well as in the output circuit. When the grid is at the same poten- tial as the filament the number of electrons going to the grid will be very small—in fact, usually negligibly small compared to the number going to the plate. The fact that the plate current can be controlled by potential varia- tions on the grid without the grid taking any current is an important property of the thermionic tube. When there is no current in the input circuit there is no power expenditure in that circuit. It therefore means that we can vary the current in the plate circuit without doing any work, oO = — NPY IT VOLTAGE Curves obtained by keeping plate voltage constant and varying grid ont be a S to a Machine The machine shop spells opportunity and big pay. It is the starting place of great inventors and designers. Machinery, appliances and all sorts of things needed in our daily life. The big world of industry revolves around the machine shop.” You can win success through the machine shop. You can reach a high position at big pay—if you avoid one danger—if you take care not to becortie a slave to one machine all your life. 27 ENGINEERS TEACH YOU MODERN SHOP PRACTICE Here is the way by which you can know tions, photographs, drawings, ‘dia- all there is to know about machinery. Here is a way by which you can put your- self in line for quick promotion, or to be your own boss. 27 Mechanical Engineers, Designers and Specialists in shop methods and t have bined to pro- duce a spare time reading course that will make you familiar with all details of Modern Shop Practice. Whether you are apprentice, mechanic or shop fore- man, or whether you are a man on the outside with a desire to know machine shop methods and practice, this great reference library brings you the informa- tion you need. What the Books Teach Tt sets forth simply and clearly every- thing you want to know—all details of grams, tables—everything to make it easy for you to learn; all this comes to you in this magnificent six-volume set of MODERN-SHOP, PRACTICE, which has gone through six: editions and which has helped to” promote ~ tho: ds. of mechanics intd well-paying pdéitions as engineers, shop superihtendents, shop owners, etc. 7 Six Volumes Shipped Free wl ? . he You are not asked to’ buy them now. You ate’ simply~asked to writé for a 7 days’ ‘free trial of:thisxsix volume set of “‘Modern* Shop 'Practice.”;.. Just pay the small shipping charges, when, the’ books arrive. Send the coupon andthe 6 books will be shipped to vou at once for7 days, free examination. Ask. any. meclanical expert what he*thinks of them:"*If you _ shop management, produc- 1 tion, lurgy, fi and your frierids do not-consider them turing, welding, dye-stamp- worth several times their price, send-them ing, tool design, tool back to us, and you won’t owe usa cent. making, foundry work, If you keep them, simply.send us $2 molding, casting, forging, within 7 days and ‘then $2 a month until pattern making, mechan- you have paid us this special introductory ical drawing, machine price of $19.80. automobile shop work” Gongult Experts Without Cost automobile shop work. If you order “‘Modern Shop Practice” Only Te. a Day at once we will enter your name for a Si lendid 1 regular $12 Consulting Membership in =e = a teibh yee pepo the American Technical Society for the Riencan ek ri romcws period of a year. This entitles you to dey cae ar 500. illust ° the advice and counsel of our staff of 2 pages, 2 aaa engineers on any problem you may have within the scope of the PARTIALSLIST OF CONTENTS SEND NO MONEY Shop Work—Shop Kinks—Gear Cutting— Turret—Lathes—Screw Machines— Manufac- Right now tear off, fill in and turing — Shop Management — Metallurgy— mail .the coupon. No money in Welding—Die Making—Metal Stamping— |: advance. No obligation. You owe Tool Making—Punch and Die Work—Tool it to yourself to inspect]these Design—Foundry Work—Malleable Practice books in -your home and see if —Forging—Pattern Making—Molding Prac- they will not prove salary-boosting tice—Mechanical Drawing—Machine Draw- volumes for you. Send coupon at ing and Design—Automobile Shop Work. once. AMERICAN TECHNICAL SOCIETY OO Se i il AMERICAN Chicago, Ill. TECHNICAL SOCIETY Dept. M-207 4 Dept. M 207 Chicago, U.S. A. Please send me, shippings chargo collect, set of Modern Shop 7 Practice for seven days’ free ex- 4 amination. If I decide to buy, I will send $2.00 within seven days and the balance at $2.00 a month until $19.80 has been paid. Then you send me a receipt showing that the $30.00 set} of books and $12.00 Iti bership are mine, and fully paid for. If IT think that I can get along without the books after the seven days’ trial, I will return them at your expense, POOR ee ee eee eee eee EEE HHT HEHEHE EE ED

Page 118

ap IGR SES eS TS SN MS RTO ae ed ADF Ege tions. and ew too. CAN YOU think of a simple, practical idea that will fill one of the many re- uests we have on file for new inven- tions? It may mean a fortune for you. Thousands of things.are needed Ricut Now: Your brainscan heip. Send to- day for our great new book—“‘Invene Protection and Exploitation’® and learn more about making money from ideas than you ever before. It tells many things that are wanted, Trade Marks, Their A postal will do— it is free. mee — —, clients, PATENTS the dollars out of thelr ADVERTISED none others possess. MMMM For SALE. FREE Advice free : vivian, fro. In INVENTION And book at once. AMM MANUFACTURING AMERICAN SUPPLEMENT. INDUSTRIES, INC. Published for the 201 Patent Dept., WASHINGTON, D. C. man with an idea. Send for free sample copy. One year’ssub- il scription 50c. an na na a Before applying for a patent you should send us a sketch or model of your invention, with a description of it, and receive our ‘Evidence of Con- ception” form—our Opinion as to the Patentable Nature of your In- vention, and our advice regarding the best way of obtaining patent protection. Our practical experience covers a period of twenty years. Our Handbook on Patents HOW toOBTAINaPATENT SENT FREE js a storehouse of valuable information and advice to inventors. All communications strictly confidential. Write us TODAY. To the Man With an Idea I offer a comprehensive, experi- enced, efficient service for his prompt, legal protection and the development of his proposition. Send sketch, or model and descrip- tion, for advice as to cost, search through prior United States pat- ents, etc. Preliminary advice glad- ly furnished without charge. My experience and familiarity with vgrious arts, frequently enable me to accurately advise clients as to probable patentability before they go to any expense. Booklet of valuable information and form for properl Wri request. disclosing your idea, free on te today. RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington, D.C. 2276-D Woolworth Building, New York City In practice this is not quite true, be- cause there is always a small amount of power wasted in apparatus in- cluded in the input circuit, such as induction coils. Of course, this device is not a perpetual-motion machine. Al- though we can obtain comparatively large current variations in the plate cir- cuit by expending Popular Science Monthly plate is at a positive potential which drags the electrons through the grid to the plate. This current is represented by the magnitude oa. If the grid be given, by means of the battery (Fig. 7), a negative potential with respect to the filament, the repelli action of the grid counteracts the at-_ a very small amount of power in the grid circuit, still the force that drives the current through the plate circuit is the plate battery E,,so that this battery sup- plies the necessary energy. « Let us now see how the current- traction due to the plate, and the — plate current ig less than before, As the negative grid potential is increased the eur- rent decreaseg continuously, asig line abc. When . the point c is reached the re pulsion due to voltage character- istic curves of the three -electrode tubecompare with that of the two-electrode tube shown in Fig. 5. In the first place, we note that the main difference between the two tubes is that one contains a grid between the filament and plate, and the grid acts like a screen to the FILAMENT... ile FIG.1O GRID © Circuit for obtaining the ampli- fication constant of a vacuum tube—a very important figure electron flow through the tube. If we keep the grid at a constant potential with respect to the filament (zero poten- tial in this case) and measure the cur- rent to the plate for increasing poten- tial on the plate; then we obtain curves that look very much like those shown in Fig. 5, except that for the same voltage between filament and plate the current to the plate is smaller. If the grid, instead of being at the same potential as the filament, be maintained at a negative potential by the grid battery, the curves will be shifted to the right, because the repelling effect of the negative grid on the electrons makes it necessary to apply higher plate voltages in order to get the same number of electrons across to the plate. Further Tube Characteristics Now, there is another set of curves that can be obtained with this type of tube by keeping the plate battery voltage constant and varying the voltage of the grid battery. See Fig. 9. When the grid is at the same potential as the filament, there is a current flowing through the tube, because the 138 Rack for life tests on vacuum tubes. Thousands of tubes were manufactured during the war the grid equals the attraction due to the plate, so that the plate cur- rent is reduced to nothing. If the plate had a lower potential to start with, the curve de’ would be obtained. It looks very much like the curve abe, but lies to the right of it. For a still smaller plate potential we get the curve e. These curves re- semble the one given in Fig. 5. There is, however, this important difference: that a change in the grid potential produces a larger change in the plate current than an equal change in the plate potential. The ratio of the change in the plate potential to the change in the grid potential that give the same change in the plate current is called the amplification constant of the tube. This is a very important con- stant, and can be measured very easily in the following way: Suppose the plate battery has a voltage of fifty volts and the grid potential is the same as that of the fila- ment. Then there is a certain current flowing through the tube. Let the plate voltage now be increased to, say, sixty volts. This has the effect of pulling more electrons away from the filament to the plate, so that the cur- rent increases. But the current can be brought back to its original value by making the grid sufficiently negative with respect to the filament. If this negative potential is found to be one volt, then the amplification con- stant of the tube is ten. This can be conveniently done with the circuit arrangement shown in Fig. 10. The voltage of the plate battery can be measured with the voltmeter V,, and the current with the current meter A. By connecting the battery E toa slide wire resistance,.r, the voltage be- tween the filament and grid, which can be measured with the voltmeter V,, can be adjusted in very small steps by sliding the contact a until the change in current produced by a change in the plate potential, and indicated by A, is exactly neutralized. In commercially used tubes the amplification constant ranges from about five to about forty, ° indicated by the '

Page 119

he Car of 1900 . “3 ea [ee & teen, { ; “5 ponen. jis 1 be C7, by Highest References, Prompt he Liga be Service, Reasonable Terms ‘ive th 24 Fu tu re =| PROTECTION SERVICE

a PATENTS TRADE-MARKS COPYRIGHTS Vs» (em = m= P REE COUPONS = 3 Se et im ae oa ) Vi VICTOR J. EVANS & CO.,Patent Attorneys | ) 2) eee oy i) } Wy] MAIN OFFICES: 760 9™ STREET, N.W., WASHINGTON, D.C. the a g})| Gentlemen: Please send me FREE OF CHARGE your books as described above. 2 iS : lly MN | Name ai a a a Address Lai eena decd sabcropeithnhadititadl wiidigetiedc si italia lial 139

Page 120

Terms Reasonable PATENTS Write for free booklet Highest References Send model or drawing for preliminary examination and report as to patentability Best Results ALL BUSINESS GIVEN PROMPT AND PROPER ATTENTION WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D.C. AF 39-Y Loan and Trost Building, Washington, D. C. THAtetatervesise PIF GEC TETEEts is eteetis gO PATEN TS \Trade Marks Send sketch or model for actual search and report. Write for Book- let of instructions on patent practice and procedure. Prompt personal service. . Geo.P Kimmel Patent Lawyer SR RUR OT USSR SSERBESSER EER SESEC EO EU CEES OPER ECE OS EO CERE POSUERE PALES ESE ERS ae oI PURO SES SOUEOU BOUSt Ce SUES OCR EE CEC SPOS ERS 528 BREE | PATENTS AND "7 —MTRADE MARKS 274 OURAY BLDG. WASHINGTON, D.C.~ DO NOT LOSE YOUR RIGHTS TO PATENT PROTECTION Before disclosing your invention to any one send for blank form “Evidence Conception”’ to be signed and witnessed. Establish your rights before filing application for patent. As registered patent attorneys we represent hundreds of inventors all over the U. S. and Canada in the advancement of their inventions. Terms reasonable. The form “Evidence of Conception,’’ sample, instructions relating to obtaining of patentand fee schedule sent upon request. Ask for them,—a postcard will do. PATENTS LACEY & LACEY Attorneys-at-Law — Patent Practice Exclusively Solicitors of U.S. and Foreign Patents Trade-Marks, Copyrights. 645 F Street, N.W., Washington, D.C. Write Us for Our Free Inventors’ Book PATENT-SENSE ESTABLISHED 1869 Protect Your Rights to Invention Write today for ‘‘Record of Invertion” which contains forms to establish évidence of concep- tion. Prompt personal service. Preliminary advice without charge. J. REANEY KELLY 732-O Woodward Building, Washington, D.C. Making Your Invention a Financial Success How best to dispose of your invention What kind of agreements to make for your protection What kind of offers and mistakes to avoid Valuable tables and other data By M. G. Delaney, an experienced inventor, in The Inventor’s Manual of Valuable Information $1.50 per copy, postpaid Additional information and Table of Contents will be mailed on request. G. E. Perry ene Publishers, 1328 Broadway, New York DEAFNESS IS MISERY- I know because I-was Deaf and had Head Noises for over 30 years. My invisible Antiseptic Ear Drums restored my hearing and my d Head Noises, and will do.it for you. They are Tiny Megaphones. Cannot be seen when worn. Effective when is caused by Catarrh or = Perforated, Partially or Wholly Destroyed Natur: a. Easy to put in, easy to take out. Are “Unseen Comforts. In- expensive. Write for Booklet and my ‘eworn statement of how I recovered my hearing. - A. O, LEONARD Suite 301, 70 5th Avenue afness - © New York City TENTS PROCURED and -~ Fine BOOK FREE TRADE-MARKS REGISTERED Pia cieteds fon Telecishost Eighteen Years’ Experience. Terms on request. ROBB & ROBB, Attorneys at Law Specializing in Patent and Trade-mark Practice exclusively 840 Southern Bidg., Washington, D. C. Instructions and 1336 Schofield Bldg., Cleveland, Ohio. - si ung and tu lucrative profession an LEARN BY MAIL TO worthwestern School 7 Toxideriny 9207 ox Gulldina Qmahs Nebraska P etc. will give our opinion as to its patentable nature. RANDOLPH & CO. 130 F St, N-W., Washington, ‘D.C. ATENTS SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent Free on request. Send model or sketch and description of your invention and we IF YOU HAVE AN INVENTION AND DESIRE TO LEARN HOW TO Tells our Terms, Methods, dienes weigher teehee misennintioleeceheair: HHO m meme meee Hee eee eee eeeeeeesesesesese® TTR Re www wwe eee eeeseeesereseseeeeereseeese | , Popular Science. Mo and sometimes more, depending on the purpose for which the tube is used, The plate voltages used on com. mercial tubes cover a very wide ran and so do the currents that pass through them. In the case of tubes used as radio de. tectors it is not necessary that the current be large, because here we are deal. ing with very small quantities. Many detector tubes operate satisfactorily with somethi like twenty volts or less on the plate, and the plate current is usually a smal} fraction of a milliampere. On the other hand, tubes that are used ag amplifiers on telephone lines usually operate on a plate voltage of about one hundred and fifty volts, with a current of several milliamperes. Then again, tubes that are used as radio trang. mitters need plate voltages of several hundred and sometimes several thous sand volts, the plate current being sometimes as high as several amperes, This shows what a tube is capable of, Let us now see how it is possible to make use of the curvature of a tube’g characteristic to detect high-frequency electromagnetic oscillations. A simple type of detector circuit is shown in Fig.11. Theincoming oscillations are picked up by the antenna, and are induced in the circuit LC. The con- denser C is variable, so that it can be adjusted until the circuit LC is in resonance with the antenna circuit. (The inductance L can, of course, also be variable if necessary.) We then obtain the highest possible alternating potential difference between the grid and the filament. These potential differences can be superimposed upon the constant voltage of grid battery inserted in grid circuit. But when using the tube asa straight detector the grid battery can usually be omitted. Suppose, then, that the plate battery voltage is so adjusted that the current for zero grid potential is given by O, (Fig. 9). The incoming oscillations from the antenna then make the grid alternately positive and negative. The current in the plate circuit therefore alternately increases and decreases. Now suppose the potential variations impressed on the grid by the incoming oscillations be represented by the wavy line shown below O. This causes the plate current to vary in the manner shown ‘by the wavy line to the right of the curve. Now, it can be seen that the difference between those two wave curves is that the voltage wave is symmetrical; that is, the positive peaks are just as large as the negative peaks, but the current wave is lop- sided, and the effect produced by the tube is similar to that produced by the crystal detector, as shown in Figs. 1, 2,'and3. In other words, audible cur- rent flows through telephone receiver. GROUND FiGn How a three-elec- trode tube is applied to radio circuits

Page 121

October, 1919 Try a Little Wireless on the Trees in Your Yard A vy. Charles P. Steinmetz, Yes Chief Consulting Engineer of the General Electric Company, has said that, “The world needs men who. know something of elec- tricity, of the operations and control of electrical power. It needs men more every year, its.very exist- ence depends on the elec- trician.”—Electrical Exper- ™~ imenter, June, 1919. a What a Knowledge of Electricity Would Mean fo YOU . A real job with a man’s size salary—that’s what it would mean. It’s easy to get it if you know electricity. Electricity is the big- gest force in the world today. It’s one of the best paying. fields aman can get into. Just see what the great Steinmetz says about elec- tricity—“ the very existence of the world depends on the electrician.” That’s the kind of business to be in for real money making. Get into it as quick as you can—train yourself at home—in your spare time. N page 83 of the July issue, PoPU- LAR SCIENCE MONTHLY told in detail how Major-General Squier, Chief Signal Officer of the Army, had successfully experimented with “tree wireless.” Here we show James V. Candido and a youthful friend from The Cyclopedia of Applied Electricity The world’s greatest electrical your finger tips. Plain, everyday Mounting the vacuum tubes in the set. Circuit used is shown below in detail Brooklyn, N. Y., trying out the idea for themselves. They consider that it is a most interesting line of experi- ment and opens up many possibilities. Fully as good results can often be obtained with a tree as with an ex- pensive aerial. Besides, one is investi- gating the unknown. There are many Plug in at proper hole for degree of amplification wanted G The set has three vacuum tubes; two small transformers; wing, grid, and aerial circuit variometers; and_ bal- anced condensers at the points shown queer twists to the possibilities. Listen to the following abbreviated excerpts from a paper that General Squier recently read before the Franklin Institute: books will fit you to hold the big- gest kind of a job. They were written by the engineers and ex- pertsthat helped to makeelectricity what it is today. These men know what you need. They give you 50 year’s of electrical experience at language and thousands of pictures make everything as simple as A BC. Glance over the ‘partial list of what the books contain and see our offer that gives them to you a whole week free. Mail the coupon today. REDUCED PRICE —A Year To Pay The regular price of this great library a) is $5.00 a volume—$40.00 for the set of GreatBig Volumes 3800 Paces 2600 Pictures Clearly Covering Elements of Electric- ity; Electrical Mea- surements; _ Electric Wiring and Lighting; Underwriter’s Elec- trical uirements; Theory, alculation, Designs and Construc- tion of Direct Current Generators and Mo- tors; Types of Genera- tors and Motors; Man- agement of Electrical achinery; Electric Lighting; Alternating Current Machinery; Power Transmission; Electric Railways; Power Stations; Stor- age Batteries; Switch- boards and Switching; Applied Electro-Chem- istry; Electric Eleva- tors; Electric Welding and Heating; Wireless Telegraphy and Tel- ephony; Land and Sub- marine Telegraphy. 8 volumes. For a limited time though you can have the whole set for $24.80 and take a year to pay for them. This is less than one cent a day for each volume. Entire set sent for FREE examination —no money in advance—return the books at) our expense if you don’t like them. Mail the Coupon Now. Don’t be satisfied with an ordinary job when a big one is open to you. AMERICAN TECHNICAL SOCIETY Dept. E-207 CHICAGO, ILL., U. S$. Ae FREE Examination Coupon 4 | AMERICAN TECHNICAL SOCIETY \ Dept. E-207, Chicago, Ul., U. S$. A. Please send me the Cyclopedia of Applied Electricity i j for 7 days’ examination, shipping charges collect. f i i I decide to buy I will send $2.00 within 7 days and bal- ance at the rate of $2.00 a month until $24.80 has been § | paid. Then you will send me a receipt showing that the set of books and a consulting Membership in your j | Society are mine and fully paid for. If I want to get along without the books, | will return them, after 7 a I days, at your expense. } Name Address Refer EL SN ON ER SE i t i i 4

Page 122

Live Books | for Live Young People Handicraft for Handy Boys Price, $2.25 Postpaid A book of this sort should prove a treasure to an inventive; industrious boy.—The Chicago Tribune. Home-Made Toys for Girls and Boys Price, $1.40 Postpaid It. will mean a year full of presents for thé children.—Boston Globe. Boy Activity Projects Price, $1.25 Postpaid Tells how to build apparatus for your own gymnasium, wireless apparatus, and so on. The Boy Electrician : Price, $2.25 Postpaid A book that appeals to the creative in- stinct of every boy. Simple Wireless Telephones and HowtoMake Them Price, $.25 Postpaid A’valuable book for the radio amateur. How to Make Wireless ‘Instruments Price, $.25 Postpaid : A real book for a real boy. The Handy Boy Price, $1.82 Postpaid This ‘book will encourage the boy to think for himself and to use his ingen- uity, and will instill in him’ an ambi- tion to.grow up prepared to do some- thing and to be something. Handicraft for Handy Girls Price, $2.00 Postpaid All sorts of articles that deft-fingered girls like to make.—Chicego Herald. -The Boy Craftsman Price, $1.82 Postpaid If a boy has any sort of mechanical turn'of mind, his parents should see that he has this book.—Boston Journal. - Carpentry and Mechanics for. Boys Price, $2.25 Postpaid Here is a book that is a never-ending source of pleasure to a boy who likes to work out his own ideas. How to make .such. things as* ‘‘Box Furniture,” “Small Gifts in‘ Wood,” ‘‘Model. Air- - planes,” “‘A Bike Garage,’’ “‘A Tobog- gan Slide,” ‘“‘A Bob Sled,” “A Lawn Roller,” ‘The Homework Bench,” “Bird Houses,” and many other things, is fully told. NO COST TO DAD! The father whose son wants to buy any of the ‘‘Live Books” in this list need not give him the money. Lend him the price. We. will show him how to earn more than the amount of your loan. , Book Department -. Popular Science Monthly 228 ‘West 39th St. New York City We may regard the nail driven in a tree as a potential earth-terminal for the study of potential distribution on the surface of the earth itself. This earth terminal is always subject to changes of potential. Radiotelegraph or radiotelephone waves cause this, as well as electrical disturbances, which are always present on the surface of the earth or in the atmosphere above. Tuned electrical circuits, suitably con- nected to the nail electrode, enable us. to select from the composite waves received, one or more of the different frequencies for particular study, just as with color screens we can select a particular component of white light, and deal with it. We may even run a highly insulated conductor into the laboratory from the nail in the tree, and connect it to the modern vacuum tube, and amplify almost at will the particular effects we are studying. This tube is a val ‘Popular Science Mont and new instrument of research for th modern laboratory. Tube and tree to. gether form a powerful instrument for the study of fundamental problems of the earth, itself as a charged sphere. Bie The ground re- quired for tree te- legraphy is simple. Merely spread out wires or chicken netting in the grass. Bury them under surface if you like At right: Hooking up the apparatus preparatory to. re- ceiving messages from all directions. All kinds of hook- ups are possible Connecting the aerial “lead” ~ the nail in the tree, — Naturally, the wire may be run inside a laboratory, if kept carefully itisu- — lated, same as any other aerial connec: tion of the kind, But working. this way gets you out: doors—and besides ~ that you can test — the efficacy of differ- _ ent’ kinds of trees Oscillator Patent Rights Decision HAT J. A. Fleming of London, England, was the original dis- coverer of the radio-receiving functions and possibilities of vacuum valves was decided some time ago by the courts. But that the owner of his patents, the Marconi Company, is also to have the rights for the transmitting capabilities was only recently affirmed. The suit was finally terminated in July. The following excerpts from the decision by Judge Mayer of the United States District Court, Southern District of New York, make clear the dominant technical points adjudicated by the case. The decision is very fundamental to the whole radio in- dustry, and—besides the interest to radio men from this angle—the case also gives a good idea as to the kinks and quirks there are in law as far as in- ventors are concerned. Most radio men are inventing, or thinking about the possibilities of inventing, at the immediate moment. The effect of the original decision of this court, as affirmed by the Circuit Court of Appeals, was to accord to Fleming’s re- ceiver invention a high place in the art. Eight or nine years after the date of this Fleming patent—the exact dates are un- 142 important—Armstrong, _Hogan, Waters man, Weagant, and probably other. experts’ in the radio art, while using these devices a8 radio-wave detectors, independently ob-+ served that the detectors possessed the fun tion of oscillating, or, in other words, - of generating radio waves. This was an extraordinary additional’ property or function of the so-called in- candescent lamp detector—of which Flem- ing had no knowledge. While his original claim covers broadly ~ the device when used in the radio art, yet . when read with the context of the specifica- tion it is plain that Fleming’s disclosure was addressed to use of the instrumentality as a detector only. It is, however, a principle of the patent law—so well settled as not to call for citations of authority—that a patentee is entitled to all of the benefits of his inven- tion, whether or not known to or foreseen py Bim. ;_... On preliminary impression there is re luctanee to extend the patent to an un- expected characteristic only observed after a considerable lapse_of time by the highly skilled men who are students in the art. Yet, after all it was Fleming who made this remarkable contribution of a wholly new device, which of itself and in its develop- ment has done so much toward the practi- cal advance of this great art... .. It is concluded, therefore, that the so- called oscillion of defendant infringes and tuat the decree heretofore filed should ‘be extended thereto with costs. “Submit the decree accordingly.

Page 123

‘Righ foe they Satisfy” BY JERY Clsee ciguretnds you’ve ever 4 smoked stopped somewhere short of — - giving you what Chesterfields can and do - givethe greater a re ee? of a oe that satisfies. : - Chesterfields do more chai please your. taste. They give to your smoking a new > zest and interest for they “touch the spot” —they let you know you’re smoking The - Chesterfield blend of fine Turkish and Domestic tobaccos really satisfies. _ “And. the blend is the manufacturer’ private formula. Unlike a patent, it can- — ~ not be copied or even closely imitated. It’s Chesterfields—and Chesterfields sor ee _— if you want this new eae in bat - Ri og Sa — Chestenim CIGARETTES. sit -and the blend cant be copied 4p

Page 124

; a Win an ; __ efiuto-Wheel __ In This Interesting Contest THE BOY who-can think of the most inter- uses for ER for earning mone; for play, we shall award mighty ee large mo ; 5 eo mighty generous prize for a few minutes’ work. And following eleven -valuable will given to sending in the Sar eet hy Semen, en god ge Kit, “ag ~ ee teering ompas ingers Watch, Axe, Banks Electric Flashlight, Poncho. INFORMATION ABOUT CONTEST 1. Any boy or girl not over 15 years may compete. 2. Contest will be judged by three men well- known in the y Scout organization. ee PE GES i e colored ca’ telling ail about Auto-Wheel. 4. OES eee waite suman of oe Coaster ‘agon Dealers in your carry the Auto-Wheel pa an 5° after meme. YOU CAN DO IT. Any live boy who know to get fun and earn eames out re good, atm ccaster wagon, has a fine chance to get the Auto- Wheel mp Here are a few pointers: The Saperwnee is : ae for york ‘= play. It’s speed. as er beari: le steel axles tires, body white ash, maple gent. ‘If there’s an Auto-Wheel dealer near you, he’ll gladly let ae see the Auto-Wheel Condor in his , and he’ll give you ideas f letter. CONTEST CLOSES NOVEMBER te toe HERE’S YOUR CHANCE. -GET BUSY Buffalo Sled Co., 357 Schenck Street, N. Tonawanda, N. Y. FO nace rma y FREE

Stronger, Clearer Voice for YOU! (fe Weakness, Weakness, huskiness and harshness banished. Your voice given a won- derful strength, a wider

Use it in your own home. silent exercises taken a few minutes pao By vigor 4... 5 ~~ - i *

Page 125

F Gatober, 1919 What to Do to Avoid Auto- mobile Engine Trouble you want to get enjoyment and cdort out of your car you must take care of it as you would a fine horse. Therefore you must: ; Not race the engine unnecessarily. Have your ear tuned for every un- usual noise. If it is a squeak locate and lubricate the part. If it is some other noise find the loose part that causes it and tighten it right away. Not keep tinkering about the engine when it isn’t necessary. Half the ability to make an adjustment or repair is the ability to discover its necessity. Have you ever noticed the motorist who seems “lucky’’ with his car, who Thousands of Electrical experts are needed now. Come to the great shops of Coyne and let us train you quickly by our sure practical way backed by 20 years of success. Earn $125 to $300 a Month LEARN DRAFTING A _ The country needs hundreds of skilled Draftsmen Come to Coyne where experts train in all lines at big salaries. you on the actual apparatus. You work Coyne is the only school in the country that gives Inspect your engine systematically ine everything from the simple hell to you the advantages of big shops full of construction c i s and machinery. This makes our drafting courses once a week. You will save money the mighty Generators, Electrical Loco- | practical, just like the job you'll have when you grad- motives and Power Plants. Everything | te. You can’t get this in any other school. ? ely WE TEACH ELECTRICITY, DRAF never seems to have a bit of trouble, pe _ se aga Look TR gs Mg everything is-neat and the engine ee: Pee Se ee eee shops We seach alt these ae - such a thorough, : e ° ° practical way that when you finish you can step right always starts immediately the self B E t in33 Month tate a position of responsibility and Ue pay. + 9 ’ ecome an Expert In -3; on s ill out the coupon mow and send it for our big starter 1s pressed Z Who doesn’t have ul P free book of informatlon. It tells what others are any breakdowns while on the road, nor No need of taking 1 to 4 years to be- | doing and have done, what you can do. curse the manufacturer for building come an expert. We have proved this Be sure and check the trade thet: interest you. Be ieee in thousands of cases. We are the only school teach- == nt oe oe such acar? Itisn’t luck at all. With ing by the original Coyne methods, which means no J COYNE SCHOOLS all adjustments properly taken care of, books, no classes—all practical training. i Dept. Rte ES | pee St. every bearing and working part lubri- Earn Your Way. Our employment department will J} Please send ‘me that big free book. cated, the whole car will run perfectly Leiaeeath a[nnmen man to earn i I’m interested in: and will continue to run with only a eenicnsinisieeicmmiiiekeman } eewssiysaee LaDrefting OPlumbing : ° n - Cooke, Director Motion Picture Operating . wee bit of attention. | , COYNE TRADE AND ENGINEERING SCHOOLS J In neglecting details you save time Dept. 30, 39-51 E. Illinois Street 5 and inconvenience to be sure but CHICAGO, ILL. eventually you will find a bad break and what time you have saved will be -— ~ wasted in expensive repairs. ASk cry Never push your car at high speed ~/ as over any road, much less a rough or a \) \ : CL EUR DAES A ASME ERI A BLT a RY slippery one. The slight gain in time a — = a4 c= will be offset by the risk of an acci- : i dent and the pounding and racking i / > which the car will receive. meee Farm S700 to $400 a Month z 3 . | 7 It has been proven that the owner soa fe V~/, Ricet in your own neighborhood. You who drives his car at average speeds of * S need only to let it be known that yon are a from twenty-five to thirty-five miles an ae g-basinaga 28 pcg: «onthe honed 3 — hour over all sorts of roads pays much Oil Engines, bas tude on unpoecstoned danent te tort 5 ae aries: more per mile for gasoline, oil and tires o than the driver who watches constantly Learn in 6 to 8 Weeks rough places and avoids them an Any man, 16 years and older, can learn here easily and quickl who drives at a rate of eighteen to Rahe Practical Method. dally ‘practice on up-to-date Autencbilien, Wreeke 2 twenty miles per hour. A car which ment im America.” Numerous Master Mechen hend intreneightieFentahs sae poneean. Is driven at a high rate of speed is oo method used to train. thousands of Soldier Mechanics in 60-day usually in the repair shop often, which graduates—many from. your pases Mind ino et a . adds much more to the cost per mile of a Only additional cost to be trained here is difference in carfare. wd Te-2 iS operation. ame iene Woe ie tides 2 expenses: TE tA \ (an) Ba It is not how many miles are covered FREE NOW bed orp oll ye. Pen one S QEfE anipu- o° * * State and occupation. : \ pa in a certain time, but the number of age pai — rplane miles of useful travel that can be § Rahe Auto and Tractor School (4 (yi i y vi-#},, i> Ss tings obtained at the least cost for fuel, oil, Dept. 2886 Kansas City, Missouri. eB ie 4 ef ’ ce the tires and repairs. pe TN ae

Page 126

By Old Established Chicago Concern We want to open an up to date branch store on the main street of every principal town and city throughout the country. High grade men are needed to manage these stores and to look after the demand for our Made-to-Measure Suits and Overcoats in their territory. No previous experience in clothing or tailoring business is necessary. Man must be clean cut and a hustler. We Stock and Equip Store At Our Expense. - You are not asked to invest a dollar. We furnish full stock of sample goods, fashion books and advertising matter for distribution and equip your store completely all ready for business at our own expense. Earn $5,000 or More a Year You will be the “boss” of your Branch Store, and it will be “up to you” to make it pay you big money in addition to your drawing account. We will pay you well from the very start as soon as you begin to work for us. When your store is opened we will allow you $175 a month from the net receipts, You will also be paid a liberal share (40%) of the profits your store earns. A hustler, in a good location, should easily make $5,000 or more a year. Start Work Now In Spare Time Send your application today on the attached coupon and we will arrange for you to start work at once in your spare time. All details will be made clear in our first letter and you will receive expensive book of samples and fashions showing high character of our line. S. LEVY, Manager, Dept. 828 325 S. Franklin St., Chicago, Ill. Send Your Application Today—Use This Coupon ‘ S. LEVY, Manager, Dept 828, i 325 S. Franklin St., Chicago, Ill. our offer also fashion book with sample, uc Sao eee mine | I am interested in the position you have open. Send me full details of y SRR eee EEE eee H EEE HEHEHE EHEEE SESE ES ESEEESESESESEES of today are fortu- nate to live in the age of the Autoand Tractor Businses. It is the greatest business in, the world. Never before has there beensuch a wonderful future for ambitious men. & () Big Demand For Trained Auto Men Think of it! —Six million automobiles in use and thousands more being sold daily. Factories are rushed to the limit. Trained automobile men are wanted everywhere. The demand exceeds the supply. That's the business you can learn here at our school,—and such is the op- portunity that awaits the trained automobile man. Earn $100 to $400 Monthly It is not at all difficult for a trained man to earn those salaries. Hundreds of our gradu- ates are doing even better than that. Auto Factories, Garages, Service Stations and Tractor Factories are continually calling on us for graduates to fill responsible postions. Many of our graduat ‘0 into busi for th lves.- There are thousands of places where good garages and the services of competent trained men are needed. These opportunities are unlimited. Complete Tractor Courses Included Complete instruction on the care, repair and mainte- nance of tractors is also included in our regular Auto Course. Tractor manufacturers give full co-operation. International, Moline and Emerson-Brantingham Co’s. have placed machines with us for the benefit of our students. Brazing - Welding and Tire Repairing Taught in Separate Courses. Big Money Earned by Trained Competent Men in These Lines. : ories rse Free Catalog—Gives com- } 8 Pp sae ag pesagee plete information with views assisted in the arrangement =i — snd cunipment, s)- of our present Course. The actual letters from satis know our equipments an fied graduates. Write for it our methods and _ heartily i recomme School. Money-Back Guarantee We guarantee to quali- fy you fora position as chauffeur, repair man, tester, demonstrator. auto electrician, garage man, automobile dealer or tractor mechanic and operator paying from $100 to $400 monthly or refund your money. Better a train and come as hundreds do. Our guarantees protect you. MICHIGAN STATE AUTO SCHOOL regressive Auto Schoolin America”—‘In the Heart of the Auto Industry” ‘eat een Weodwand ae. Detroit, Mich. U.S.A. 146 Popular Science Moy 7 : Don’t be a road hog. Of all Pests this kind of driver is the worst, Observe the rules of the road. Have respect. for those who are using -the same highway. Remember that cour. tesy and consideration to others will always win you the same. The very best method of using the brakes is that which applies pressure to them so that the car gradually comes to a stop. Coast whenever possible for this jg another way of saving gasoline and tires. Get rid of that idea of “showing off,” and avoid spectacular stops. The practice is disgusting to everyone and there may come a time when, through constant “showing off,” the brakes will fail, and then the doctor’s advieg won’t help you any. The careful driver shuts down the throttle before he reaches his stopping point, and allows the car to run on its momentum until he reaches the stop- ping point. Then he applies his brakes easily and comes to a perfect stop at the exact place where he in- tends to halt. Try these few sugges- tions and check up your car bill with the three months previous. You will never again stray from the economical pathway.—F. A. CUFFE. A Celluloid Window for a Yacht Curtain SIMPLE device, which will be ap- preciated by all yachtsmen, who, in steering a motor-boat into the wind, must face the sting of the salt spray, is a cel- luloid window, placed in the curtain immedi- ately in front of the helmsman’s seat. There should.’ be three of these windows, each about 5 in. by 8 in., equally spaced. on the front of the cur- tain. The cellu- loid window- panes are bound with strong canvas, and then, by means of snap fasteners, just like ordinary glove snaps, these panes are attached to the curtain. The margin of the curtain about the window is made of a double layer of canvas so as to cover up the snaps and binding. Occasionally, as the celluloid be comes-encrusted with salt by evapora- tion of the salt: water, the helmsman must reach around the side of the curtain and clean the window so that he is able to see ahead. Such a window is a vast improve- ment over the usual type, which compels the raising of the curtain altogether and. then fending off the driving spray with the uplifted arm.—FLoyp L. DARROW. CELLULOID SNAP FASTENERS SS SAa__©#_ssse LLIB CANVAS BINDING You can make your own automobile or yacht curtains by using this method,

Page 127

VW/UREL | i : : WY WourRUIZER | e Reg. U. S. Pat. Of. | Complete Musical Outfits on Free Trial A NEW plan. Wurlitzer, the largest general music house in the world, is offer- ing the finest musical instruments with complete outfits at factory price. Wurlitzer instruments are standard of the world. With each instrument comes a handsome carrying case; all attachments and extra parts; music tack; instruction book-and book of musical selections. This new plan gives you at a tremendous saving all the things that otherwise you would have to buy separately at regular prices. Any Wurlitzer Complete Musical Outfit will be sent for a full week’s free trial in your own home. Play the instrument:as if it were your own. Examine all the details of the complete musica! outfit You are under no obligation to buy. At the end of the week return th. instrument and outfit at our expense if you w: Convenient Monthly Payments If you decide to keep the instrument, you may pay the direct-from- geenGnats pes in small monthly sums. A few cents a day will make one of these beautiful instruments and outfits your own. These Complete Outfits are ready. Send for one on free trial. Violin Mellophone Flute Mandolin Banjo-Ukelele Hawaiian Cornet Trap Drum Bugle TenorBanjo Banjo Guitar Saxophone _ Clarionet Fife Banjo- Banjo-Guitet Viola Trombone Piccolo Guitar Mandolin Uhkelele Cello Send for FREE Illustrated Catalog The instrument of your choice and everything in the complete outfit fully illus | The Rudolph Wurlitzer Co., Dept. 1207 nk deed, wth Eo decals Gf Gan tne ial 117 E. 4th St., Cincinnati, 0.—329 S. Wabash Ave., Chicag and easy payment plan. We = facnsssA sevtosmamm of all musi- Send me your new catalog with illustrations in_color and cal instruments. This won- full description of the Wurlitzer Complete Outfits and derful catalog is ‘a veritable details or the free trial and easy payment offer, | musical encyclopedia. We will send it to you free and without obligation. Mention the musical instrument in Sh SSS SSS ‘ ro" * oe vi ail Pr oad DU RIEIO acc cex. ncocscceacenctnsersennigueniinsnnataeennninaamnane Mail the coupon now. 4 . es. Oe Dept. 7 117 East 4th Street, Cincinnati as ae rei a 529 South W mm i or (Musical instrument Iam specially interested in) j \ which you are interested. { [ |

Page 128

Se ak oo Be TI ce hp nn ne te ne OU’LL prefer Camel ciga- rettes expert blend of choice Turkish and choice Domestic tobaccos to either kind smoked straight. Your taste will prove that! Camels are so exceptional in flavor, in fragrance and in mel- lowness that you quickly real- ize their remarkable quality. It will be your constant delight to find Camels so full bodied though so mild and smooth. You may gratify your keenest desires to smoke liberally. Camels will not tire your taste. Your enjoyment increases as R. J. REYNOLDS TOBACCO COMPANY, Winston-Salem, 148 when you travel. JCIGARETTES you get to know Camels better. They return such generous cigarette satisfaction. Camels certainly fit your taste exactly as if they had been made for it. - Camels are unlike any ciga- rette you ever smoked. For in- stance, they leave no unpleasant cigaretty aftertaste or cigaretty odor. In fact Camels are ina class by themselves! That’s why we ask you to compare Camels with any cigarette in the world at any price! You will not look for or expect premiums, coupons or gifts. ‘You’ll prefer Camel quality! 18 cents a package Camels are sold everywhere in scientifically sealed packages of 20 cigarettes; or ten packages (200 cigarettes) in a glassine. paper-covered carton. strongly recommend this carton for the home or office supply or Popular Science Mo ME We

Page 129

nage here in ages of ackages assine. n. We carton pply or ~ October, 1919 $100 A WEEK. From This 5c Game e of the hour—American Box Ball. Roce ee proprietors of Box Ball Alleys making oo a week from just two alleys. C.T. Patter- of[liinois opened three alleys and cleaned up = pr vga ow pet eer" i Ene ates eight alleys an American tet} out of the proceeds fhe has built a 3-story BR 0 home. You, too, can make big money out of this fascinating game. Easy Payments Don’t worry about the money. We help you start. Pay for the equip- ment on time out of the alleys’ earnings. Little cash is needed. Write today for particulars of easy payment plan. No Operating Cost Practically 100% profit. No operating expenses— no helpers, no wages to pay. Pins reset and balls returned automatically. Automatic electric light- ed score board. Write today for full description and amazing letters from Box Ball operators. American Box Ball Co. 811 Van Buren St., Indianapolis, Ind. Battery Charging Your Biggest Money-lTaker | $500.00 a Month Income with This HB 32 Batte Eureka Storage Battery Co., Houston, Texas, wry Bhan e first little machine we bought of you has given us the very best of service. With the new large machine, my income per month from c! is $500.00.’’ You, too, Can Make Big Profits with an HB 32 Battery Charg $2 6-volt auto batteries, = or equivalent in 12- or 24-volt bat- teries, at one time, for 10c to l5c =: Neg igure electrical no valuat y lance on terms. Outfit easily Absolute Honey. uarantee. Write TODA for full in formation. Send this ad. poart BROTHERS COMPANY Box $10. T Ohio. Ri ceeeaul Mfrs, Sines’ 1898 JASSPINS-RINGS OMECT FROM FACTORY TO YOU OUR NEW CATALOG ‘LATEST UP-TO-DATE DESIGNS FREE. | ~C. K. GROUSE CO. 42 Bruce Ave.. North Attleboro, Learn to Dance! You can learn Fox-Trot, One-Step, Waltz and latest ‘“‘up-to-the-minute”’ society dances $800.70 the first two ! in your own home by the wonderful Peak Sys- tem of Mail Instruction. New Diagram Method. Easily learned; no music needed; th ds taught fully. Write for Special Terms. Send today for FREE information and surprisingly low offer. PROF. W. C. PEAK, Graduate of Castie House Room 102, 821 Crescent Place, CHICAGO, ILL. Dollars in Hares We pay $7.00 to $9.50 a pair and express charges. Big Profits. We furnish guaranteed high grade stock and buy all you raise. Use back » barn, cellar, attic. Con- tract and illustrated Catalog Free. STANDARD FOOD & FUR ASS’N 307 C Broadway New York | TEACH ) + @h) SDCONDUMH A, 1 won World’s First Prize for best course in ro omg Under my guidance you = penman. i students as instructors in commercial colleges at hig h = Dwi 2%, — PRegeme a patter nman, Mi ite ou one of m: e ns and a copy of the Ransomerian ‘Journal Write today. C. W. RANSOM, 488 Essex Bldg., Kansas City, Mo. ELECTRICITY MADE SIMPLE 4.20%... devoid of plain and understandable. $1.00 Postpaid. Popular Science Monthly, 225 W. 39th St., New York technicalities. Simple, An Inexpensively Made Jack for the Automobile HE illustration shows a simple and easily made lever jack for raising one of the rear driving wheels of an automobile and holding it steady by FF The diagram shows how to make a good, inexpensive automobile jack means of anchor pins, which sink into the ground, permitting the car to operate machinery driven by a belt from its rear wheel. The jack is made of wood or light iron. The lever A, with the hole in its end, may be connected by the bolt C to any of the holes B. Fastened to the top of the lever is a half circle bearing for the automobile axle to rest upon. The pin C may be placed at any desired jog for elevating the machine.—JOHN D. Lowry. To Use Gas Under Pressure for Experimental Work HIS gas pump may be used for filling miniature balloons, or in other operations where it is desired to use gas under pressure in a small quantity. The pressure is only limited by the head of water that can be obtained. The diagram explains the construction clearly. To start the apparatus, fill the flask with water through the funnel and also fill the bottle. Turn on the gas and open the valve in the short siphon. This will fill the bottle with gas. Close both these valves and open the other two. Start the long siphon by closing the air vent in the flask and filling the funnel so that the water level comes above the bend in the tube. When the bottle 3c TO BALLOON TO GAS SUPPLY F aeaain ita Ait _L Toy balloons and miniature dirigibles may be inflated with the contrivance VALVE is full shut off the valve to the bal- loon, and also the one to the long siphon. The operation is repeated until the required amount of gas has been forced into the balloon. Of course it will be only necessary to start the siphon once, as after that it will be full of water.—GEORGE CAREY. 149 Here’s Health and Power Vim and Vigor LL men—and all women, too,—wish these marks of good health. If you feel you haven’t them, you should write for book, “Health and Beauty.” Read it! Then make up your mind whether you think that the White Cross Electric Vibrator can bring to you these vital signals of health. You will read in this book and in other literature we will send, what several hundred people have found out about vibrationiand what it has done for them. A CUS: Uy ELECTRIC \ VIBRATOR | All the Exhilarating Joys of Life—Strength—Y outh Do you feei just right? If you do not—if you haven’t that vigorous ‘‘go ahead” feeling all the time—don’t fail to send the coupon for full particularsabout the White Cross Electric Vibra- tor. In vibration there crets of life. You now Mave an opportunity of “seeing what vibration will dofor you and how every nerve, every fiber —your whole b will fairly tingle. With our Combination Outfits, Treatments — right in your own home. The White Cross Electric Vibrator is the result of years of work and experiment. If you have vour house wired for electricity, you connect it up as easily as anelectric lamp; if not, we can supply you with models operated on their own batteries. Nature’s Aid to Beauty Beauty can not stay long where health does not rule supreme. It may be onlya slight illness that is the cause for a muddy complexion, dull eyes, or unsightly blemishes. Thousands have found that vibration & corrected these illnesses—and beauty .~ resulted. Read the stories in ourZ free booklet. iJ J J Vibrating Chair _ FREE Our patented at- tachment makes a Vibrating Chair out of 7 your rocker in your own ~ home. A few minutes in ; this vibrating chair and every nerve and fiber in your body tingles with the virile force of reju- venated youth. Sent FREE with every vibrator. This is the only vibrator having this patented feature. Send the COUPON © ™ ™=™ u Get our big FREE book LINDSTROM “Health and Beauty.” Tells all about the marvels of vi- SMITH Co. bration. Send coupon éod.zy. 1100 $. Wabash Avenue, Lindstrom, Smith Co., Mfgrs., Dept. 1207, Chicago, Ill, 1100 S. Wabash Ave. Pa ty Bays gs Dept. 1207, Chicago, ill. 3 free and ‘prevaid, your fre We -also manufacture book on Vibrat rh og Eo White Cross Electric Irons, ad Seema t the Waite Coats Toaster Stoves, Grilis, Immersion Heaters, Heat- ing Pads, Curling Irons, q Fans, Medical Batteries, Name Hair and Shoe Dryers. Handled by-Reliable Addr Dealers Everywhere axty My Dealer’s Name i8..0.000000000+

Page 130

appreniice says: ‘‘Almost the first tool I ever heard of was a Starrett ‘mike.’ Somebody pinched Dad’s out of his jumper pocket and the fuss he made showed he thought it was some tool, even if he had had it close on twentv years, _.“‘When I got into the shop myselt: I noticed the toolmakers and every- body who had ‘fussy’ jobs preferred Starrett Tools. ‘*There’s something about ’em that the fellows like: Yeh! They’re accu- rate and they’re convenient, but I guess the fact that the men who make “em:are pretty good mechanics them- selves; has something to do with it. “What? Sure I’m getting me a set of Star- rett Tools—I need ’em every day. Yes, I got me orie of those seventy-five cent Starrett Apprentice Books, too. It saves me asking the foreman a question every five minutes. Now, when I want to know how to do some- thing, I can look in the book and study it out myself.” The L. S. STARRETT COMPANY THE ‘WORLD'S GREATEST TOOLMAKERS Manufacturers of Hack Saws Unexcelled ATHOL, MASS. For thirty-nine years Starrett Tools have measured the accuracy of the world’s work. Catalogue No. 21 “Ww” free upon request. 42-972 ce - BA WKLEM EONS 1.) — | Pt 7 Direct from Factory to You | ALL SIZES AND STYLES 2, 3, 4, 6, 8, 12, 16, 22 and 30 H-P. LOW PRICES Don’t wait if you need an engine for any purpose. NOW isthe time to buy. } Life Guarantee Against Defects Big surplus horse-power. Above price in- cludes engine complete on skids, ready to operate when you get it. Safe delivery guaran- teed. Immed: jiate factory shipment. Write or wire for big, new catalog of these wonderful engines. Wrrre ENGINE Works . 2223 Oakiand Ave. KANSAS CITY, MO. 2223 Empire Bidg. PITTSBURGH, PA. Every User of Tools Will Appreciate This Handy Bag Made of Harness Leather— Strong and Durable Combines all the good features of the various common leather bags. Strongly built for rough usage. Bottom is three ply and steel studded. Has saw and bit holder, hand strap, and shoulder strap with pad. A mighty good, all-around tool bag. Six sizes ranging from 14x 8 inches to 24 x8 inches. Show this ad to your dealer and ask for the genuine KLEIN tool bag. If unable to get it write us. MATHIAS KLEIN & SONS, Mfrs. CANAL STA. 3, CHICAGO: Popular Science M onthly How to Make a F oot-Power Reversing Tap on there are a large number of small parts, such as small die castings or punchings, to be tapped and threaded, and they do not require more than 5 or 6 threads, the arrange- ment shown in the illustration may be successfully used if a reversing power tap is not available. A shaft is mounted upon two bear- ings and a hole cut through the bench to allow two small belts to run down to the two foot pedals. The tap is mounted on the end of the shaft in a chuck or other suitable holder. Inopera- tion, the piece is held to the tap, and one pedal is pressed. This causes the shaft to revolve, thereby tapping the hole. Then the other pedal is pressed and the shaft makes the required number of revolutions in the opposite direction to run the tap out again.—VicToR H. Topp. COLLARS TAP SHAFT, 2” FASTEN BELT in / 8 CENTER One pedal runs the tap into the hole, the other revolves it out again Why Distilled Water is Used for Batteries GOOD deal of ignorance is abroad as to why nothing but distilled water should be used in storage cells. All water but distilled water contains mineral matterinsolution, and although this may be small. in quantity, as the water evaporates the mineral matter is left behind and all that ever enters the cell remains there. It is obvious, therefore, that the amount of mineral matter in solution constantly in- creases. Very soon the concen- tration becomes so great that the mineral salts are deposited on the plates of the cells. Electro- lytic action then begins between the salts and the plates, with the result that the framework of the plates is eaten away and the life of the cell destroyed. The energy wasted in the process, too, is considerable. Some people have the idea that boiling the water helps, but boiled water is worse than unboiled, for in the boiling the concentration of mineral matter in solution is only increased. Therefore, avoid the use of any but pure distilled water in filling storage cells.—FLOoyD L. DARROW. Storage batteries must have distilled water; otherwise the plates will be eaten away

Page 131

er of - die ped juire nge- y be OWer ear- ench is road tilled cells, tains ough s the ter is s the rious, neral | in- Very. ncen- omes it the '$ are n the. the ctro- then ween d the 1 the - the k of 1s is r and ' the ed in that oiled n the ineral ased. | r but orage " October, 1919 The Time to Know Output When a run of work is fin- ished, you can check up on your machine’s speed by counting the product by hand—but too late to im- prove the rate-of-work on that run. A Veeder Counter on your ma- chine will record the output as the machine works, so the high- est possible production-rate can be maintained without a let-up. The difference between a hap- hazard production-rate and the attainable standard is always great enough to make COUNTERS necessary equipment in making machines make good on a larger scale. ZR The above Revolution Set-Back Counter records the output of any machine wherea shaft-revolution indicates an operation. Sets back to zero from any figure by turning knob once round. Supplied with from four to ten figure-wheels, as required. Price with four figures, as illustrated, $8.50 (List). Cut less than one half size. The Number 14 Ratchet Counter at left registers oneforeachthrow of the lever, re- cording number of machine-opera- tions. Supplied with outsidestops which regulate the throw of the lever, and having return spring action which auto- matically returns the lever into position for the next count. The lever is adjustable, allowing the counter to be used at any angle. Price, $2.00. Cut nearly full size. Most any machine you're interested in can be equipped with a Veeder Counter; the Veeder booklet shows the many styles and sizes.’ Copy on request. The Veeder Mfg. Co. 44 Sargeant St., Hartford, Conn. An Emergency Repair for Eyeglasses WING to a broken lens in a pair of prescription glasses a local com- muter contemplated a long railroad ride in the morning, minus the usual newspaper. The break (Fig. 1) was of such a nature that but little cement-holding surface was present. However, the trouble was overcome with a piece of sheet brass as follows: Cutting a piece of thin brass sheeting in the shape shown in Fig. 2, so as to allow it to project somewhat beyond OBLONG CUT OUT = EDGE OF BRASS TURNED OVER FIG.3 = LENS CROSS~SECTION OF FIGURE THREE BROKEN OUT FIG.2 FIG.I A thin piece of brass makes an emergency repair for eyeglasses the shoulder of the clamp, a hole was bored for the screw. Applying cement to the brass, the lens was put in place and the brass carefully slid into position, a portion of the edges being under the screw holding the clamp. Tightening the screw forced the ce- ment to take an even hold on the lens. Turning over the edges of the brass as in Fig. 3 made the repair complete.—JAMES M. KANE. How to Place Electric Lights in Candlesticks T is not an easy task to drill through silver or china candlesticks in. order to permit a wire to pass through; in- deed, one runs a chance of destroying so. I have been very successful in plac- ing electric lights in candlesticks by the use of the little fixture described in the ensuing paragraphs. A piece of Yin. brass pipe is threaded on one end to fit the socket, and a hole drilled in one side permits the wire to be passed through. The sheet brass, which is of thin gage, is soldered to the pipe. A hole is punched through an ordinary large rubber stopper and slipped over the pipe. This not only holds the fixture in the candlestick, but also acts as an insulator. The sockets I have been using are for lamps with candelabrum base, and the bulbs 15-watt. Regular sockets and bulbs may be used just as well. The wiring runs along the back of the dresser and down to a plug in the floor or baseboard. If the fixture and sockets are nickeled it adds very much to their beauty and attractiveness. —HARVEY MEAD. 161 the candlestick if he attempts to do SHORTHAND VERY SIMPLE LESSONS ‘MONEY BACK IF YOU FAIL A complete shorthand adequate for any and every purpose, that. can be learned in Seven Days! Incredible as this may seem, it is none the less a fact. Paragon shorthand is simplified shorthand—a triumph of Twentieth Century Effi- ciency. The older technical shorthand systems involved in- tricate positions and shading. There were thousands of word signs and an endless maze of rules to learn and to remember. That is why it was for experts only—people who wrote shorthand and did nothing else. Paragon Shorthand is different. IT IS FOR EVERYBODY A week’s study—and you know shorthand! The explanation is in its wonderful simplicity. You need only to learn the Paragon Alphabet, 26 simple word signs, .6._préfiz. contractions and one general rule for abbreviation. That is why it is quickly learned, easily used, always remembered. FOR PROFESSIONAL STENOGRAPHERS PARAGON is just the thing! It eliminates the need of time, travel and expense for special school- ing. It can be learned at home evenings without interfering with other work you may be eng: in. Being so quickly learned, you can begin s prac- tice earlier and qualify for a steongraphic position more quickly! Paragon is positively guara adequate for ail purposes. Thousands of stenograph- ers, secretaries, and court reporters use it. ITS USE IN BUSINESS Executives, clerks, bookkeepers, salesinen, journalists, writers, lawyers, preachers, etc., find that Paragon Shorthand helps tremendously in efficiency and volume of work done. Students find it indis- pensable. $5 FOR THE COMPLETE COURSE The entire course consists of 7 lessons, so arranged that you can master each one in a single evenings’ study. Fill out the coupon below, enclose $5 in currency or P.O. or express money order. Keep it for seven days and if you are not perfectly sat : return it and your money will be refunded at once. We refer you to the publishers of this or any other Magazine regarding our responsibility and integrity. Order NOW. Paragon Institute, Home Study Dept., 601 Broad Street, Suite 505, Newark, N. J. ——-USE THIS COUPON=== PARAGON INSTITUTE, Home Study Dept., 601 Broad Street, Suite 505 Newark, N. J. Enclosed find $5.00 for the complete Course of Paragon Shorthand, with the understanding that if I am not sat’ at the end of seven days, I may return it and the $5 00 willbe refunded. (Pop. Science 10-19)

Page 132

MOSSBERG ALL STEEL WRENCHES AND TOOLS Universal recognition in those princi- ples of manufacture which insure to the user of Mossberg products the utmost in value and in service. Such has been the standard of material, workmanship and guarantee, and such ‘has been the appreciation of a multi- tude of satisfied customers. ILLUSTRATED HERE ARE: Mossberg Socket Set, No. 17, for Ford Cars. No. 74, Adjustable Wrench; also solid handle wrenches, 6 and 12 inch, with speed brace. No. 645, Reverse and Brake Pedal Ten- sion Spring Wrench, and No. 660 Wheel uller. Mossberg All Steel Socket Wrench Set, No. 45, which contains an assortment of 15 sockets, universal joint and speed brace. Send for complete catalogue and particulars FRANK MOSSBERG CO, WRENCHSMITHS FOR 20 YEARS ATTLEBORO, MASS. U.S.A Making a Waterbox Noiseless with Rubber Hose ANY. waterboxes are very noisy after the chain has been pulled and they are refilling with water. This noise may be easily eliminated by placing a piece of rubber garden RUBBER The rubber pipe absorbs all the noise and makes the box noiseless hose between the nozzle of the faucet and the bottom of the box. This allows the water to enter into the waterbox below the surface of the water, and thus completely eliminates the noise.—VICTOR H. Topp. Adaptable Break-up Coops for Poultry HE combination indoor and out- door breaking-up system is an excellent one. Both coops, one inside and one outside the poultry house, are of the slat bottom type, about 2 ft. wide, 3 ft. long, and 3 ft. high, the top and sides being of hen wire. These coops are attached to the rear house wall about 4 ft. from the ground. They are connected with each other by an aperture in the wall a foot square, closed from the side with a board slide. The season of the year and weather conditions determine how this breaking-up equipment is handled. In stormy weather the year around, and through the winter, the inside coop alone is used. Through the warm months, in pleasant weather, the outside coop is the favorite. Some- times broody hens are kept in the out- side coop days and the inside coop nights. “T adopted the outside coop,” says the inventor, “chiefly to speed up the poor WALL The poultry appreciate being indoors when it rains exactly as much as youdo breaking-up process in warm weather, when the temperature of the poultry pen rose so high that the brooding fever persisted in hens even when placed on slats. Ordinarily, of course, the slat bottom, allowing cold air to strike the hen’s body from beneath, would check the’ fever. In warm weather, I consider the outside coop twice as efficient in breaking-up as the inside one.—J. T. BARTLETT. 152 ’ Popular Sctence Monthly BROWN & SHARPE MACHINISTS’ TOOLS a 8 al - é Ro 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. 27 BROWN & SHARPE MFG. CO. Providence, R. I., U.S.A. Vernier Caliper “The Mark that Guarantees Quailty.”

Page 133

October, 1919 A: Magnetic ‘‘Fishing’’ Tool for Locating Blind Wiring N wiring old buildings it is the cus- Pas to install the wires, covered with an insulating tubing called “loom,” in the partitions and ceilings without disturbing the exterior, when- r possible. Ov This practice is called “fishing’”’ by the electrical trade. It consists of STIFF WIRE yCORaET STEEL — MAGNETIZED ROUND STEEL ROD ST WINE LATHE PLASTER JOIST > FLOORING eee AR This tool makes “blind wire hunting” less tedious and more positive, requiring less time having a helper dangle a line, on the end of which is fastened a nail or cther weight, inside the partitions, from an opening cut or bored in the header of the partition, from the room above, or from the switch outlet hole in the same room as the partition, as the case . May be. The wireman goes into the cellar, if the partition is on the first floor, and bores as many holes close together as there are wires to enter the partition, upward through the flooring, the sill or bottom plate of the partition, and the layer of plaster always: found there. He then proceeds to take a short length of wire, with a hook on one end, and, after inserting it into one of the holes, he twists it around and around until he catches the line the helper is jiggling from above. This is usually a tedious operation, and it is pure luck to a great extent. The tool shown in the illustration is intended to make this ‘“‘fishing’’ pro- cess less tedious and more positive in operation. The construction is: made clear and all parts are labeled. It consists, essentially, of a length of round steel rod about 3 in. long and 3g in. in diameter, which is strongly magnetized to form a bar magnet. One end is slotted to take the corset steel forming the flexible handle and is held in place by a machine-screw passing through the rod and steel. At the other end a stiff wire hook is threaded into the rod from the side, and bent as shown. A hole is also ‘provided in the rod through which a strong piece of twine is threaded and The Largest Circular Saw in Use in the World is a Simonds. This one, an Inserted Tooth Cut-Off Saw, 96 inches in diameter, is now in use in Oregon. Naturally Simonds makes the Big Saws because they make the Better Ones. And it is our own steel quality that’s responsible. SIMONDS SAW STEEL PRODUCTS whether large or small, whether made to cut wood or metal, are all part of a thoroughly reli- able family, tested during 87 years of good ser- vice to world wide industry. Simonds Saws should be in every workshop, ma- chine shop and home. Buy one to complete your tool equipment. Simonds Manufacturing Company ‘“‘Made Right Since 1832’? FITCHBURG, MASSACHUSETTS New Orleans, La. San Francisco, Cal. Seattle, Wash. Portland, Ore. New York City Lockport, N. Y. Chicago, Ill. Memphis, Tenn. London, England Montreal, Que. Vancouver, B. C. St. Johns, N. B. 153

Page 134

Canceled Government Contracts We have secured a large quantity of Small Motors, Generators and Charging Outfits. This material is new, still in original cases and carries the full factory guarantee. This is Your Opportunity to buy new, guaranteed [YOUR OPPORTUNITY] Ba Charging M Sutfite For use on 110 volt, A. C., 60 cycle, single phase current only. * Tigers” $48-50 150 watts, $0 volts, S amperes . s $68-50 se coanperes - HOQ-50 wil end’ €. 0.0 son sett 80-2 O4.50 | Smination. . MONEY BACK Ail outfits complete with switch- board m4 cut shown. GUARANTEE 1H. P. ‘ . 2H.P. $72.60 6H. P. $102.50 7 '\ im _\. Electrical Apparatus of Standard Manufacture H INDUCTION eSeMOTOR 50 110 or 220 volts, A. C. ® 60 cycle, single phase, 1750 R. P. M. WRITE FOR CATALOGUE. BARGAINS IN MOTORS AND GENERATORS. SPECIAL QUANTITY PRICES Jay POLYPHASE MOTORS it 110-220 REPULSION MOTORS 33° Soperars omerae” MEW MOTORS si. ser% TH ee7 MANUFACTURERS’ DISTRIBUTER ALL MOTORS COMPLETE AS CUT 110 2 ee 4 cycle,single phase 1750 R. P. M. WASHING MACHINE MOTOR Suitable for oper- ating Small Com- pressors, Coffee e Grinders, Bottle Washers, Lathes Drill Presses, ete. Making Electric Lights Fao vam 40) Cl The HB Lighting and Battery Charging Set § makes your. electric lights for as low ‘ as 2c per KW, and at the same time brings profits of $100 to $150 per month charging batteries. _ Sturdy, depend- able, economical to operate from line- shaft or engine. No electrical experience required Small Payment Puts This Money- Maker in Your Garage or Shop Balance oneasy terms. Profits pay for outfit. Absolute Money- our Service Back Guarantee. Department about s. in i our ‘etterhead and write TODAY for information Hobart Brothers Box S105 Troy, Ohio Succesaful Manufacturers Since 1893 CHAS. H. JOHNSTON - WestEnd - PITTSBURGH, PA. — PROFITS (§ harsing Batteries euiepensenen: Armstrong Stocks and Dies ei HINGED PIPE VISES PIPE CUTTERS PIPE AND BOLT DIES MANUFACTURED BY THE ARMSTRONG MFG. CO. 337 Knowlton Street - Bridgeport, Conn. « Savemoney at present prices. You can’t beat our as ‘OTTAWA ENGinES ; Gasoline, Distillate, Gas. 6, 7, 8 16, 12, 16 and 22 H-P. , and Sawrig styles. Use TOOL CASES Machinists and Toolmakers Write for our booklet showing the best built and most practical selec- tien of Tool Cases on the market. e ship direct from factory and guarantee please you or refund all money. MGerstacriSons 50 Columbia St., Dayton, Ohio $15.00 A WEEK FOR SPARE TIME WORK OR . $60.00 to $90.00 A WEEK FOR WHOLE TIME. That’s what being a local representative for POPULAR SCIENCE MONTHLY can bring to you. If you are willing to hustla then we want you. POPULAR SCIENCE MONTHLY 225 West 39th Street, New York Using Bull-Dog Die-Stock No. 102, six pipe sizes 4” to 1-44” in one tool the pipe. His THE 2180 E. Gist St., cut threads that feel different. The user senses the ease and smoothness of Bull-Dog pipe-threading the minute the dies bite warded when he sees the finished job. Ask your dealer or send for Bull-Dog Catalog of 20 tools, plain or ratchet. BULL-DOG DIE-STOCKS good judgment and confidence are re- . OSTER MFG. CO. Cleveland, Ohio. fastened. The other end of the corset steel is fastened to a wooden handle made from a length of broom-stick. The manner of using the tool is clear- ly depicted. It is inserted through the hole from below, as previously men- tioned, and then the cord attached to the rod or magnet is pulled taut to bend the corset steel. is revolved in the partition. As soon as the magnet strikes the nail it wil] stick to it, the contact being felt by the helper, who immediately notifies the wireman in the cellar that con- nection is made. This tool will pay for the trouble of making it on its very first job. The tool must be small enough to insert through a 1-1/16 in. hole as this is the size bit used exclusively in knob and tube wiring.—J. A. WEAVER. The entire tool How to Make an Inexpensive Saw-Filing Tripod MONG the problems that worry the carpenter, is that of getting a good light for filing his saws, and a convenient position to filethemin. If he fastens his clamp to a window opening, he is dependent upon the sun and the weather. If he has it on his puatont With the contrivance shown the saw may be operated upon in the best possible light work-bench, the light is usually far from being what it should. And saws that are properly filed determine very largely both the quality of the work and the ease and enjoyment of working. The tripod shown in the illustration overcomes these various difficulties. It is inexpensive to make, and the carpenter who once uses it will never go back to the old way. The device consists of two pieces of 2 by 4 timber, opposed to each other, and grasping between them at their upper ends a piece of 1 by 6, slanting sharply to the rear. On the square, 12 and 24 give the plumb and level cuts for the 2 by 4’s, and 12 and 16 for the 1 by 6. The height depends upon the stature and filing habits of the workman,. but 4 ft. may be taken as the standard height for the edge of the saw from the floor. To put the tripod together, nail the 1 by 6toone2 by 4. Then toenail the other 2 by 4 into place and put one big spike through all three pieces. Cut about an inch and a half off the pointed top of the tripod. The device by which the clamp is attached depends, of course, upon the type of clamp used.—HENRyY SIMON. Popilar Science Monthly

Page 135

am ~~ a Se. ~~ eee |S ss October, 1919 Mee an 2 Speeding Up the Tedious Process of Section Lining HE simple device shown in the il- lustration can very easily be made and will increase the speed and accuracy of section lining. A thin strip of soft wood or a piece of cellu- loid, such as is used by draftsmen for FOR SMALL ~\. TRIANGLE (fle GROOVE FOR FINE. SPACING GROOVE COARSE SPACING This ingenious device increases the speed and accuracy of line drawing making templates, is notched 1/16 in. longer than the short edge of the triangle to be used. This groove may be made longer for broad spacing of the lines or shorter for fine work. In use the strip is brought against the edge of the triangle with the left hand, and the strip and triangle i \oved al- ternately after drawing each line. This gives a uniform spacing not ob- tainable by free-hand methods. The other long edge of the guide strip may be grooved for another spacing of the lines, or in order to use a smaller triangle.x—E. EARL GLASS. You Can Repair that Eye- glass with Celluloid NE day, when adjusting my eye- glasses, they fell to the floor and were broken, leaving a portion of the lens in the clamp. I did not wish to have the lens reground, so I decided to try and mend the broken lens my- self. Cementing the two sections to- gether, I laid the glasses away until the cement had thoroughly set. To insure against another break in the same place, I cut two pieces of celluloid out of a section of a broken CELLULC'D PIECES Glasses are usually broken unexpectedly. Here’s a way to fix them temporarily automobile window and cemented them against either side of the broken portion of the lens. This method of effecting a repair was very neat, owing to the transparency of the celluloid, and makes the repaired portion ex- ceedingly strong—JAMES P, KANE. ERY handy feature,” Sargent Auto-Set Bench Plane Cuts fast Cuts true said a master carpenter as he glanced at the new Auto-Set Adjustment. Picking up the plane, he tried it in practical use. “That’s a mighty good plane,” was his verdict. That exactly describes the Sargent Auto-Set:—a dependable tool, with a big improvement added to save time and trouble. The cap iron and clamp are fitted together as one piece, with a set- screw to regulate the position. An- other set screw adjusts the cutter. May be taken down for whetting in a few seconds and assembled as quickly. Cutter and cap iron go back into exactly the same position as before. Made in six sizes; smooth or corrugated bottom; fore, jack, smooth or jointer pate terns. Descriptive booklet on request. Sargent Cylinder Day and Night Latch Put it on doors—inside and outside, front and back—that you want securely barred. An ordinary mortise lock is “easy pickings,” but a cylinder latch keeps the intruder outside. ‘Press the button” to dead lock the bolt or hold it back, as de- sired. “Pull the button” to re- lease:.the bolt. Self-locking— closing thedoorspringsthe latch. SARGENT & COMPANY, Hisdwore Manufacturers 50 Water Street, New Haven, Conn. SARGENT LOCKS Agee HARDWARE electrical,rope, aire plane, piano, pipe- organ, flat, hoops, bale-ties, tacks, nails, barbed -wite, concrete re - inforcv- ment, springs, _net- ting, wire fences, steel posts, trolley- road wires and rail bonds, wire wh heels, auto-towing cables, horse-shoes, Illustrated Books Describing Uses, FREE American Steel & Wire Co.* ®***k¢2:7,2.2 6-5-4 THE — SLIDE RULE will solve any Fiplicad in addition, subtraction, aye lication, division and proportion scale gives any root or power rs ‘any number. Gives Logarithms, Sines, Tangents, Cosines, Cotangents and the decimal equivalents 1 ee ompared with the paper utility rules / which sell for $1.00 and are put to- // gether with eeee pane ag = a he accurate, simple and ¢ ison shows that tiie randoubtedly tbe ‘fastest and most complete rule made. Our refund guarantee protects you from loss or DO te gemsrecoenigg An in- pages. = illus- ions, is sent with each rule. Di- ameter 4 inches. Made in two , models, Metal “ite coated steel) $1.00. White Celluloid, $1. ar Leather Case, 650c. e Your money back i: you are not satisfied Send for Catulogue of "Side Rules. GILSON SLIDE RULE CO., _NILES, MICH. 155 WUE Pilliod TOOL CASES EXCEL Machinists and Tool Makers find them moat satisfactory in construction, appearance, service and price. Imme- diate shipment. Booklet describing 20 styles on request. The Pilliod Lumber Co. Dept. A, Swanton, Ohio 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 Mines.

Page 136

<s

Training

Treatment

_ Promotion

How to join

The U. S. Navy offers you in return for faithtul service: Every ocean on earth has a U.S. Navy ship sailing for a port worth seeing. Travel is the greatest single educational force. Our sailors travel and are given shore leave to see inland sights. Thorough training is given at one of the four great stations — Newport, Norfolk, Great Lakes and San Francisco. Trade schools develop skilled men for the navy’s needs. On board ship a man is always learning. Trade, industry and business ability are de- veloped. Food, health and moral welfare are super- vised by responsible experts. Work and play are rightly planned for contentment and efficiency. Advancement is unlimited for worthy men who apply themselves. Between the newest recruit and the commander-in-chief there lies only study, application and ability. Apply at any Navy recruiting station; select the branch of service you like; pass the nec- essary examination. Your pay begins the day you join.

Popular Science M ontily i

Page 137

sits eI DAl SA i rer ct tones + October, 1919 Transforming a Drill into a Drill-Press SMALL drill with a three-jaw chuck can be made into a serviceable drill-press with the aid of a stand and proper supports. As there are so many different makes of hand drills on the market no detailed description can be given, but the drawing shows clearly the general ‘igh Gin 1 if SLIDING MEMBER Nk! The hole can be bored in half the time demanded by the ordinary drilling method construction. The lever enables a steady pressure to be applied with little effort. Hinges connect the dif- ferent parts of the lever with the back of the stand and with the sliding member which holds the drill proper. The upper part of the drawing shows the way in which the sliding member is held in place. If a little candle wax is placed on all sliding surfaces it will work very much easier. A stand like this will prevent a lot of broken drills.—M. K. GorDON, JR. Don’t Let that Chimney Become Clogged Up HORTLY, now, the furnace will go into action again, and then comes the problem of removing soot from the chimney. Every week or two, as needed, spread out on the cellar floor six or eight sheets of news- paper and sprinkle them generously with kerosene oil. Then wrap them all up into a bundle and shove them into the fire-pit of the furnace with all drafts open, and shut the door. Light the papers and ali the soot will be burnt out of the pipes and chimney, leaving them perfectly clean. In using this method the furnace pipe will, if very dirty become cherry red, and large pieces of burning soot will emerge from the top of chimney. For this reason it is best to do this work on a rainy day to be safe irom any possible firee—G, H. Davis. Everywhere in the world Disston Hand Saws are accepted as the highest stand- ard; for in saws, as in everything else quality and durability are soon recog- nized. All steel used in making Disston Saws is Disston Crucible Steel—spec- ially made in the Disston Plant. Whatever kind of a saw you want— Hand Saw, Circular Saw, Cross-cut Saw, Band Saw, Buck Saw, Hack Saw—get a Disston. Disston Saws and Tools are sold by the better grade of hardware dealers everywhere. Many of them specialize in Disston ex- clusively. Write for the Disston Handbook on Saws—it tells how to select, use and care for Disston Saws and Tools. HENRY DISSTON & SONS, Inc. PHILADELPHIA, U. S. A. ‘tAmerica’s Largest and Longest - Established Makers of Hand Saws, Cross-cut Saws, Band Saws, Circular Saws, and Tools. Chicago Cincinnati Boston SanFrancisco Seattle New Orleans Memphis Bangor, Me. Portland, Ore, Vancouver, B. C. Sydney, Australia Canadian Works: Toronto, Canada ISSTON SAWS AND TOOLS Standard for Nearly Eighty Years -— and Growing Faster Every Year 157

Page 138

N° 60 “BAILEY” Iron Spoke Shaves Only a few of the ‘numbers manufactured are shown in the illus- tration. The cutters of all numbers are made -from a high-grade of steel, well tempered and ready for use. Made with two styles of Handles, raised and straight, and through each a hole is made, so that when not in use the tool may be hung up out of the way. Manufactured by TANLEY Rute & Leve Co. New Barram. Conn. U.S.A. | Popular Science Monthly : For the Home Draftsman HE usual folding table lid desk is very well adapted for drafting purposes, but its convenience and utility can be very greatly enhanced by converting the lid into a first-class drawing board and: adding a self-alining parallel ruler as a permanent fixture. The method of doing this involves comparatively little work and, as is shown in the accompanying drawings, the alteration is invisible when the — desk is closed. Four small rollers are required. These are made from metal disks with holes bored through the centers, and grooved to carry a cord, which rer END HAS WEDGE SLOT FOR HOLDING CORD. CONNECTION MOVES UP & DOWN WHEN CORD 1S SLACKED The diagram shows exactly why the ruler is always in perfect alinement maintains the parallel action of the ruler. The straight-edge is provided with lengthwise slots at each end, for angu- lar movement, when the na- ture of the drawing neces- sitates other than horizon- tal lines. Four metal spindles, wash- ers and nuts, on which the rollers revolve, are needed for fastening these to the draw- ing board or desk lid. Two adjustable It appears as an ordi- nary writing desk when the cover is shut thumb-screws for securing the straight- : edge to the alining-cord, provide means of detaching the ruler and shift- ing it from the horizontal position. The upper face of the board is drilled part of the way through at each corner, to accommo- date the roller slots across the board on the upper side. Connect these bored holes and pro- vide a recess for the cord to slide in. Cn -.the under. side of the board di- agonal grooves are cut, which open 158: Y ELS SSS SSS SS SSS SSS VIM The pulleys permit the cords to aline the straight-edge By G. A. Luers at the ends into the roller recesses. The cord slides through these channels. Diagonal cross-pieces are made to CORK INSERTS _- ROLLER SLOTS IN. | - BOTTOM | SLOTS IN TOP oy, a ADJUSTING THUMB SCREW STRAIGHT EDGE LORD — SECTION X-X SLOT COVER Here is the layout of the system of pulleys which alines the straight-edge be screwed over these openings when the cord is in place, concealing and protecting them. The cross-pieces should be made of some pleasantly contrasting wood. When the desk lid is of hard wood, four holesshould be drilled at the corners for inserting corks or soft pieces of wood, into which thumb-tacks are pushed when attaching the paper. The Proper Care of Electric Motor Brushes N all electrical machines, the brushes on a stud must aline prop- erly with each other, and with the com- mutator bar from front to back of the commutator. An accurate method of spacing the brushes is to place a strip of paper tape around the outer edge of the commutator and mark the paper where the ends overlap. After removing the tape, divide it with a pair of compasses, or a scale, into as many parts as there are poles upon the machine. Then replace the tape around the commutator, pasting the overlapping ends together. The brushes are then set and spaced by the marks on the paper, care being taken that the brush-holders are clamped to the stud in the proper position. After being spaced, ihe brushes are fitted to the commutator. In doing this, a strip of sandpaper is passed between the commutator and brush face, coarse paper being used first to obtain an approximate fit, followed by a very fine paper, which gives a close and accurate fit. When sandpapering brushes, the sandpaper should be held close to the commutator to prevent rounding the tip of the brush when drawing the paper away. It should be withdrawn in the direction of rota- tion. After sandpapering, the resulting carbon dust should be blown away from the armature, the air being di- rected away from the rotating part, so that the carbon dust. does not drift into the windings.—J. WILLIARD HERSHEY. 1)