Popular Science Monthly 1921-12: Vol 99 Iss 6

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AERO SLED THAT CAN BE MADE AT HOME—SEE PAGE 88 eels OFS > #8 “cw, bt a i etaey * § ape Stup endous Battle Pictures of the Next War” $240 in Prizes for Your Practical Ideas DECEMBER 300 Pictures of New Inventions 25 CENTS ae ae : te, SFr ee fee ae ees 5S a Ne

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{ " 4 bes ae, ‘ Bs : ; i nil Sg - ey eS z é at rat 4 pe yr: ar: = + ‘ Ps eS S gee x bp ° e : i on a er ‘HAVE+0. make ; special trips to supply all the _ ‘people who want - ‘Murads for Christmas gifts. . SE Fer ae pe y es Seon i as ae e Fee gh Ne re Ys a ee Ho les: cin \ cities watch showil game! Do tastic Wo only schem trait Atlan Presic wirele Paris UL

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December, 1921; Vol. 99, No. 6 25 Cents a Copy; $3 a Year How the World’s First Wireless News-Picture Was Published in New York City at 225 West Thirty-ninth Street Flashed Across the Atlantic Ocean Paris gets President Harding’s portrait in twenty minutes By Wilfred S. Ogden owe January Popular Science Monthly described the apparatus by which Edouard Bélin had sent photographs by telegraphy. By midsummer M. Bélin had realized improvements predicted in our first article, and was able to undertake transoceanic wire- lessing of pictures and handwriting! You are sure to find fas- cinating information in the following account of his new apparatus. HILE the crowds are still filing out from the football field, theater audiences in cities a thousand miles away are watching actual motion-pictures showing the last plays of the game! Do you call that merely a fan- tastic dream? Wouldn’t you also have said only a few months ago, that the scheme of flashing a man’s por- trait by wireless across the Atlantic Ocean was merely a fan- tastic dream? Yet this amazing feat is actu- ally one of the miracles wrought by science in 1921! A picture of President Harding in action was wirelessed from Annapolis to Paris in the space of twenty min- — ‘ i CYLINDER The beam of light at the receiv- ing station is controlled by the radio impulses sent out from the transmitting station. Bélin’s greatest problem was to make sure that the two cylinders located thousands of miles apart revolve at the same rate. A system of electric chronometers connected with the radio outfits solved the problem utes! How many people are familiar with the imagination- ‘stirring details of this pictorial conquest of space? How many even know that it occurred? Somewhat crude, but wholly recognizable, was the Harding portrait as received at the Paris end; and surely from the germ of this first wireless picture, progress to future radio broadcasting of moving news-photographs while the events pictured are actually taking place seems no more impos- sible than many another modern miracle that has been accom- plished by science. The Miracle Picture of the Year! Here is the first important news-picture ever to be sent by wireless. It is an action por- trait of President Harding, exactly as it was received in Paris, twenty minutes after M. Edouard Bélin’s radio apparatus had started sending it from Annapolis At the left is the cylinder with the chrome- gelatine print wrapped around it. The micro- phone point travels over the cylinder in the same way as the reproducer on the old type phonograph In general, the wireless outfit with which M. Edouard Bélin sent the Harding picture is the same as that with which he sent pictures over telephone and telegraph wires, as de- seribed a year ago in Popular Science Monthly. A new method, however, is utilized to keep the two cylinders, thousands of miles apart, revolving at exactly the same rate of speed. On one of the cylinders is pasted the. picture to be transmitted, and sensitized paper on the cylinder at the other end is acted on by a beam of light, reflected under the control of radio waves, which are, in turn, governed by a needle moving over the sending cylinder. In wireless transmission, these 21 Saree ae Ee ST Sa - dee oftm

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22 cylinders are operated by small dynamos instead of by clockwork, and their uniform movement is assured by a regulating chronometer with electric contacts, which stops and starts the cylinders at each revo- lution. The simultaneous starting of the two cylinders would be assured by the two regulators if the latter could only be made to keep perfect time, but this condition cannot be realized. In order to overcome this difficulty, M. Bélin has devised the following method: At each liberation of the transmitting cylinder, the wireless sta- tion sends out a dot similar to the noontime signal. The receiving station does the same and the operator of the latter adjusts his apparatus until he hears the two dots simultaneously. being taken down at the receiving end in its characteristic written form. Even if “‘static’’ interferes with the transmis- sion, enough of each letter will be re- produced to render the message legible. It is not necessary to make a photograph of the written message before sending it. The writer uses special ink that gives sufficient relief for the sending-needle to feel when the paper on which this raised message is written is rolled on the sending cylinder. Another disadvantage of ordinary wire- less which the Bélin apparatus does-away with is the fact that any message sent by radio is practically howled out for all the world to hear. Engineers are hopefully at work on plans which will ultimately assure Popular Science Monthly It would seem, in the case of M. Bélin’s apparatus, that any given station likewise might capture the picture that was being sent, simply by tuning to the right wave length. The sending cylinder probably wouldn’t correspond in speed of revolutions to the receiving cylinder that was “‘listening in,’”’ the photographic points would there- fore be more spaced out or more closed up on the receiving cylinder than on the send- ing cylinder; but even so, there is still a chance that they would remain legible, However, if the transmitting cylinder re- volved in an irregular way, stopping and starting at unexpected intervals, the result produced on a receiving cylinder turning uniformly would be an illegible scrawl. In sending pictures long dis- tances by wireless, it has been necessary to reduce the cylinders’ speed from two revolutions a second—the time for wire trans- mission—to one turn in four seconds, making the time required to transmit a picture twenty minutes instead of two and a half. Compensating for this delay, however, is the belief that Bélin’s system may make wireless sta- tions independent of electrical disturbances which frequently “ball up” ordinary wireless mes- sages. At certain hours and seasons, electrical storms drown the dots and dashes of the Morse signals, and produce so much interfer- ence that it is often necessary to repeat a message two or three times before it is comprehensible. These repetitions reduce the num- ber of messages that can be handled by a wireless station, and Fingerprint reproductions, as received over the wire in Paris, three minutes after they had been taken from a captured suspect in the provinces. prediction made by Popular Science Monthly last January, that the apparatus of M. Bélin would prove invaluable in running down criminals. Thus is realized the The points would be out of place both vertically and horizontally, It is this little trick that M. Bélin expects to use for sending written messagesinsecret. He is perfecting a compact secret-mes- sage apparatus that can be kept upon any desk. With an equip- ment of this kind, the foreign representative of an American business house could write personal messages to his home office, to be transmitted from the cylinder on his desk by telephone, cable, or wireless. Using a rhythm of revo- lutions agreed upon by code, he could be certain that nobody ex- cept the operator of the receiving cylinder that was adjusted to the secret rhythm could understand a word. World-important diplomatic interchanges, when this system is finally perfected, will be carried on by an actual exchange of au- thentic handwritten documents, most of the day’s communications are crowded through in certain hours when atmospheric conditions are favorable. A message sent by Bélin’s system, on the other hand, goes in facsimile, each letter secrecy in wireless messages, but the fact remains that to-day practically any mes- sage can be heard by almost any wireless station that has the capacity to receive the sender’s wave lengths. carried broadcast through the air, , yet secret from all but sender and receiver; while men in New York will be able to close important deals in San Francisco, instantly transmitting endorsed checks and signed contracts across the continent. Machine Ties Parcels as Reaper Binds Grain LEVEN years ago J. J. Bachmayer was in the vegetable business. His fingers got so sore tying bunches of onions and radishes, that he determined to invent a parcel-tying machine. A year later he built the first machine out of old junk and bicycle sprocket wheels. For seven years he struggled to get people to use it, but it was not until 1917, when a machine was developed for tying candy-boxes that the company had any great success. The machine is electrically operated. A box or parcel which is to be tied—the length or width does not matter, but the height must not exceed five and a half inches—is passed over the recoil trip, which pulls the twine around one way, and ties a neat, strong knot without waste of cord. To tie the package both lengthwise and crosswise it must be passed through the machine again. The tying action is based upon that of a self-binding reaper, but this machine ties the twine tightly in the first place, instead of tying a knot in a loose cord while the straw is compressed, and relying upon the expansion of the bundle to tighten the knot. Watch for These Features Next Month Travel by Pullman Auto Bus How Music-Rolls are Made Trawler Seeks Sunken Treasure Your Family’s Heredity Chart New Japanese Plane-Carrier Subway 400 Feet Below Surface Cylinder on Automobile Wind- Shield Contains Sunshade Tae who find their pleasure behind a steering-wheel will appreciate this sunshade, which is neat and compact and. unobtrusive when not in use. The driver is shown pulling it across the wind-shield where it is hooked to a special attachment. The shade is of green silk. When unhooked, the shade flies back into its ec No screws are needed tc attach thi ory, as it is provided with clips which snp instantly over the ends of the wing-shiel/.

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V4 Da © & TD TR RS © OR Sorter December, 1921 This Month’s News of the Universe Earth to Plow through Broken Comet’s Wreckage How science explains November meteor shower ARTH’S biggest adventure this month will be its collision with a sort of celestial sandbar—a vast, sweeping path through the heavens composed of a lost comet’s debris, whose myriad fragments, rush- ing into our atmosphere at twenty miles a second, will furnish one of the regular November showers of shoot- ing stars. Just why displays of meteors should thus enliven the night skies—especially in August and November—often puz- zles the average observer. Astronomers now explain that nearly every annual spray of falling stars originates in the earth’s rush through the swarming track of broken-up com- ets’ wreckage, and that in our orbit around the sun we naturally strike these tracks at the same time each year. The meteors due on Novem- ber 27, for instance, are the remains of Biela’s comet, which, straying into the solar system from outer space, appar- ently couldn’t stand the strain and began to break up under the pull of the sun and of the various planets among which it rushed in its elliptical course. Our earth nearly collided with the head of this comet in 1832, passing only two and a half times the earth’s diameter away from it. When Biela’s comet returned in 1845, it was observed to split into two comets. The smaller one lagged behind until the distance separating them was 160,000 miles. In 1852, the distance between the two had widened to 1,300,- 000 miles, and was still increasing. © Modern Publishing Company How Scriven Bolton, famous astronomer, pictures the earth’s annual November rush through the vast shoal of meteor fragments left by Biela’s lost comet Comet parti- cles, myriads no larger than a pinhead, others some- times bigger than a man, flash into flame as they strike our at- mosphere and are quite burned up be- fore reaching the ground After this return the comet was never seen again, except in a changed state. On November 27, 1872, the date of the earth’s passage across the comet’s orbit, a tremen- dous shower of shooting stars occurred from 6 P.M. until midnight, and it is thought that our globe actually crashed through the disintegrated head of the comet itself. The fate of Biela’s comet is not an iso- Tated instance. Several cases on record show that the subdivision and final disin- tegration of many comets is not an un- common occurrence. A comet’s head is believed to be a bunch of meteorites, rang- ing in size from stone and iron blocks weighing many tons, down to the finest powder or dust. Burned up by friction when they hit our atmosphere, few of these fragments ever strike the earth, although it is estimated that over 146,000,000,000 of them bombard us annually.

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Where the Popular Science Monthly “Last Discoverers” Are Now Seeking New World Riches for Mankind Earth’s few remaining unknown spaces are being “mopped up” by an unprecedented number of explorers E are living to-day in the greatest W period of exploration that the world has ever known. During 1921 hundreds of men have gone forth into the waste spaces of the earth seeking at the risk of their lives new wealth and knowledge for mankind’s benefit. Coal, oil, minerals, new medicines, and precious stones represent in part the ob- jects of their search; but more than that, this vast after-the-war revival of explora- tion is apparently going to clean up earth’s last remaining mystery spots. With one or two exceptions the hundreds of explorers in the field to-day are not striving for spectacular goals of discovery. Rather, they are consolidating the gains in our knowledge of outlying portions of the globe made by the Pearys and the Scotts who went before them. They are “mopping up”’ the earth. The last objectives to which the ex- plorer has yet to push are shown on the accompanying map, the black portions of which represent large areas of the earth of which we know absolutely nothing. This year sees Lieutenant-Colonel Bury on his way to climb Mount Everest, the By Ralph R. Perry world’s highest mountain and the one really spectacular goal left since the winning of the poles. Parties will soon push into the virgin wilderness in the interior of New Guinea. Before long some exceptionally daring adventurer will cross the untrodden Arabian desert of Roba-el-Khali. “‘Mopping Up" Arabia and India Roba-el-Khali is shown on the map in the interior of southern Arabia. On its outskirts there are petroleum springs. What lies beyond, no one can say. There may be more oil there, but not even the native Arabs have crossed this waste of shifting sand and naked rock, blazing under a tropical sun that makes it the hottest por- tion of the earth’s surface. If a man were to take young she-camels in full milk and push out in the spring, some explorers think that this waste might be crossed, but as it is 850 miles long and 650 miles wide, no one has made the attempt, as yet. It is the largest blank space on the map. To the north our chart shows two smaller, divided dark spaces. These formed one area a few years ago, but this year travelers pushed through from north to south, and we now have some informa- tion on the country lying thirty miles on either side of the route. At the foot of Mount Everest is the kingdom of Nepal, of which we know nothing except from the reports of natives, It is an independent Mussulman kingdom, and the maharajah refuses to permit a white man toset foot in hiskingdom. A few men have penetrated the southern border, but only for a short distance. Even the party which is about to climb Mount Everest was refused the right to cross Nepal, and was forced to make a detour into Tibet and will climb the mountain from the northern side. Nepal will prob- ably be the last unknown area on the map. The same condition exists in the interior of New Guinea, where savages attack every exploring party that has left the coast. This island is owned by Great Britain, Holland, and France, and a com- bined expedition equipped for resisting the natives was about to set out when the out- break of the war postponed the attempt. quest of South regions. the Little is known of the shaded areas, which include about a seventh of the earth’s surface ~ Dd A i »o) / ———) ) 7 Hd iN i NT oe Sa A \ —> ai by iO ~ ae The large maps in- dicate the objectives of fifteen recent ex- peditions, all of great popular interest, particularly the con- Mount Everest and Shackle- ton’s exploration of Polar from Nothing known of the regions ee colored black. ei sable deserts, mountains, and savage native tribes have barred the explor- a i * COG aey: 7 Ne The new explorer seeks everything diamonds and oil medicines and a parasite for the boll-weevil whatever is Impas- ers—as yet “Wd Q\ r 3 \w/ WH to new

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SES SE eS a a = oe BS | a i Ed ey =e © December, 1921 © Illustrated London News nn reereeerenneneroeeseeeeeneseseoeneensenscestssenetnsessesnseesntenenstansoustnestannsnnsscaenscesianionsnasieeielsepipneSsSEnaaRIEEaTaEIEareEEEeEEaEaemeenE ean STORES AND) SPECIMENS RANGE-FINDER, BINNACLE, ETC. GYRO SIR ERNEST, \y SOMPASS SHACKLETONS.. >." QUARTERS SS a | ; pt | > §. \wikeress M SOUNDING GYRO MACHINE COMPASS SURF-BOAT oe DARK-ROOM IS-TON WATER- AIRPLANE TANK FUSELAGE ENGINE-ROOM The diminutive **Quest,’’ only 111 feet long and 200 tons displacement, in which Sir Ernest Shackieton will survey the Antarctic. Balloons, a baby airplane, and special ocean sounding apparatus comprise part of the equipment carried It is to be resumed in the near future, since the forests of the interior are believed to be rich in natural resources. The largest unknown areas, of course, are those surrounding the poles, but the ex- peditions of Shackleton and Stefansson are constantly adding to our knowledge of these sections. Among the parties now seeking new knowledge in the Arctic is that of Donald B.. Macmillan, which will make special studies of polar magnetism and the aurora. ; How Little We Really Know Outside of the Arctic, it is true, we know something about nearly all the rest of the earth—but in spots it is very, very little. Throughout the vast shaded areas on our map we know little more than the courses of the navigable streams. The whole of northern Canada is practically un- known, and what undreamed-of possibili- ties may lie there are hinted at by the recent discovery of oil on the Mackensie. The same is true of Siberia, the Sudan, almost the whole of interior Africa, central Asia, and the deserts of Australia. When the French pushed into the Sudan, which was thought to be well mapped, they found streams and oases from fifty to a hundred miles distant from the points the maps declared them to be located—which would indicate that our geographical knowledge is nothing to boast of. In the valley of the Amazon there are three areas, each larger than the New England States, of which our knowledge is the slightest. Although Africa has been crossed and recrossed from end to end, the traveler is not surprised to find that water is often from one- to two- days’ march from the points indicated on the map—which is apt to be fatal, in a dry country. Ifthe day of the explorer is over, there was never such an opportunity for scientific expeditions. These are made up of parties of five or six men sent out by the great museums and societies of the various nations. They live in the wilderness for months, even for years at a time. One man will make a careful map. A geologist will study the under- lying rock strata, a zoologist gathers data on the plant and animal life, the anthropol- ogist learns the habits of the primitive natives, the entomologist collects new species of insects,and when all have com- pleted their work, scientists possess full and exact data on the conditions existing in the country, and the possibilities, if any, for commercial exploitation. At the present time literally hundreds of these expeditions are in the field. We have shown some fifteen of the more important on our map. In\the Antarctic, Shackleton is sailing in search of anisland. The charts show two large islands in the Southern Pacific—Dougherty Isiands and the Nim- rods. Is there really any such land? Nearly a hundred years ago whalers claimed to have sighted an island there. No one has ever seen it since. If the islands do exist, if it was not a mirage or a floating iceberg that was seen, the land would make a useful radio station in the chain which is rapidly encircling the globe. Shackleton intends to search until he either finds these islands or proves definitely that they do not exist. Then he will sail farther south to the Antarctic ice, to chart 3000 miles of un- known coast, to discover new sites for coal- ing, whaling, and wireless stations, and to make deep-sea soundings. Scientific Research Inspires Explorers The new spirit that has arisen in explora- tion since the discovery of the poles is mani- fest in the records of the two expeditions by Captain Scott. In the first, which was before the discovery of the South Pole, he simply made a dash to the farthest point south ever reached. This was pure ex- ploration. In the second expedition, in which he lost his life, he was actuated by the newer scientific motives. His party had found thirty-five pounds of fossil bones that gave evidence of the life that existed in the Antarctic before the formation of the polar ice—specimens of incalculable scientific interest. On his return, food failed, oil for heat gave out, his party was so overcome by privation and weakness that one of their number deliberately wandered out into the darkness to die in order to conserve the food supply of the rest. The men tottered toward their base camp and safety by piti- fully short marches, discarding everything that impeded their progress—but to the very end they dragged those thirty-five pounds of fossils. They had set out for scientific evidence and knowledge, and although they died, the fossils were found in their last camp by the rescue party. It is this spirit that actuates the later-day ex- (Concluded on page 111)

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ey ie. ts —CREW CLAD GAS ARMOR ARMORED BOMBING LS LLES EMITTING Popular Science Monthly “Civilization Must Abolish War Prophetic pictures, based on statements by famous men, ALL-METAL AIRPLANES These pictures reveal the alternatives to the prevention of ano her world war. is awakening to the fact that unless the Washington Disarmament Conference paves the way toward peace, no mode of destruction will b> banned in the next conflict ed INVASION—“‘Fleets of fast-mov- ing tanks equipped with tzns of liquid gas, against which the enemy will probably have no protection, will cross the frontier and obliterate every living thing in the fields and farms, the villages and cities of the enemy’s country. While life is being swept away around the frontier, fleets of airplanes will attack the enemy’s great industrial and government centers. All these attacks will be made against the civil population in order to compel it to accept the will of the attackers.”— Lieutenant-Colonel Fuller, Chief General Staff Officer of the British Tank Corps. HE NEW TANKS —([They will be] “organized in large units, with General Staff tanks, telegraph tanks, tanks carrying reserve supplies. . . . They will be armed with machine guns, and guns of all calibers.”— General Eugene Debeney, Commander of the French First Army during the war. ETHAL RAYS—“T imagine from the progress that has been made in the past—that in the future we will not have recourse to gas alone, but will employ every force of nature that we can; and there is a tendency at present for progress in the development of the different forms of rays which can be turned to lethal pur- poses . . . which will shrivel up or para- lyze or poison hu- man beings if they are unpro- tected.’”? — Major- General Swinton (British), one of the tank inventors. ous materials smeare chemicals. Public opinion The soldier of the next war will be clad constantly in gas armor made of impervi- with e suit pic- tured was developed by the American army

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December, 1921 or War Will Destroy Civilization” show why disarmament is the great international problem DIRIGIBLES DIRECTING ATTA AND DROPPING G AND EXPLOSIVE:

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Hostilities will be inaugurated by myriads of airplanes and fleets of tanks. A few hours later will come gas bombardment of — commercial and e At least one great power is known to beatwork on PP a machine by which lethal rays can be directed at the enemy’s military and civil centers industrial centers, killing hosts of civilians or driving them b HE BOMBARDMENT—“In ‘the next war’ this gas bombardment of capitals and great towns is not only a possibility but a strong probability—almost a cer- tainty.” ‘‘. . . cellars will never form a defence against sinking lethal, cell-killing gases like lewisite and its probable succes- sors. ~ “The shelters must be large enough to accommodate the people of a whole city; they must be deep enough in the ground to resist the enormous explosive force of the great new bombs; they must be gas- proofed, either by rendering them airtight and furnishing oxygen to keep the inmates alive, or by providing ventilators which make the outer air pass through an anti- dote. : “They must be as easily accessible as a subway—even more accessible. This owground virtually involves rebuilding modern cities, if the inhabitants expect to survive a war.” . . . “Had the war continued, Paris would have been attacked from the air on a new plan. “A first wave of airplanes would have dropped on the city roofs tons of small bombs which released burning phos- phorus. ...It would have started a conflagration against which the fire depart- ment would have been almost helpless, in a hundred quarters of the city. “Into the light furnished by this gen- eral fire the Germans proposed to send second and third waves of airplanes loaded with heaviest bombs. ... From that the gas bombardment would have been but a short step.” — Will Irwin, famous war correspondent, in ‘“‘The Next War.” SSS. ee

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Popular Science Monthly Railroads Use Motor-Buses to Improve Service Motorized equipment now used on short lines is designed to compete with highway buses soon be riding in a new type of gasoline-driven ear which will operate over many short branch lines and interurban routes more cheap- ly than steam or electric trains. After various makeshift ex- periments with auto-trucks converted into passenger coaches, the railroads have be- gun to feel the need of a stand- ardized rail-car that will regain for them their lost short-haul traffic. Several truck manu-. facturers are now experiment- ing with vehicles of this type, and one particularly interest- ing model has just been put upon the market. It is a sig- nificant advance in the never- ceasing struggle for cheaper and more convenient trans- portation. This Car Is a Hybrid FR s00n be passengers may A New Vision of Railroad Service OTOR-BUSES equipped wheels to enable them to run on rails have been tried successfully on many short roads. Over a sixty-eight-mile stretch through the Hetch-Hetchy Valley of California, buses are transporting passengers and freight. several parts of New England large railroads have found motor-buses to be the solution of the problem of giving satisfactory commuting service at reduced cost. reason to believe that the motor-bus may eventually supplant the coal-driven locomotive on the numerous branch lines. tion would mean faster and more frequent service, cleaner travel, and lower transportation costs.—The Editor. The new car is neither a motor-truck with fianged wheels nor a railway-car with a gasoline engine, but rather it is a happy and sensible com- bination of the best elements in both. Its power plant, con- sisting of engine, clutch, trans- mission and their accessories, is founded on motor-truck prac- tice, but the wheels, brakes, the body, and its appoint- ments are “railroad style.” Gasoline-driven railway-cars MGGAGE-ROO One of the motor-cars developed especially for the N.Y., N.H. & H.R. R. for use on their branch lines with flanged It is not without The substitu- four times as frequent is four times as good. The rail-car not only gives the railways an opportunity to make money on branch-line passenger service that they now offer, but it will enable them to win back a sizable per- centage of the traffic that has gone to the motor-bus and the motor-car. On a conservative In basis, it is estimated that the railways annually lose $200,- 000,000 in revenue because of competition by road vehicles. Much of this revenue has been lost because the railroads have been unable to compete with frequent service. A train once or twice a day could not be considered by a traveling pub- lic that could obtain motor- buses every few minutes or every hour, or an automobile at command. But the fre- quency of service which the low-cost rail-car offers will do much to bring back a large share of this business. It is expected that many in- terurban electric lines that because of recent conditions in the traction field have been forced to allow their rolling stock, power houses, overhead trolley system, etc., to run down, can recuperate quickly by the purchase of rail-cars of this type. On steam lines the car’s use is not confined to ‘‘feeders” and short branch routes, but are not new; neither are motor-buses with railway wheels. But a hybrid vehicle combining the best features of both is as novel as it is interesting. It represents a deliberate attempt by one of the leading truck manufacturers to get railway business, and to get it by giving the railroads something that they want acutely but heretofore have not been able to buy; to wit: a thirty-one-passenger vehicle that can be run for fifteen cents a mile, or a thirty-six-passenger-and-baggage car that can be run at twenty-five cents a mile, including interest on investment and depreciation charges. It costs one dollar and fifty cents to two dollars a mile to total cost is eighteen dollars, and if an average of only twenty passengers is main- tained, at three cents a mile the revenue is seventy-two dollars a day, or a profit of fifty-four dollars. Furthermore, there is no question but that much additional business might be obtained by making several trips a day instead of one. On the average branch line, the public is served by one two-car train each way each day. The same seating capacity may be obtained by four rail-cars. Service four times as fre- quent is thus offered at less than half the In the eyes of the public, service cost. operate a railroad-train of two or three cars, each car having a seating capacity of seventy passengers. Railroads that are losing money on short-haul passen- ger traffic have already found that a gasoline rail-car will turn losses into profits. As an example, there is a sixty- mile railroad in the western part of New York State, serving a rural population of about ten thousand. The volume of passenger traffic is not sufficient for profitable operation of one train a day in each direction. Therefore, no passen- ger service is offered, although there is a freight-train every other day. The rail-car makes passenger transportation economically feasible on this road. Assuming one car makes a round trip each way, a total of one hundred and twenty miles, at fifteen cents a mile, the A motor-bus has been operating this ast summer on the Narragansett Pier branch of the New Haven lines with complete satis- faction to the patrons will be extended to commuting service in the off-peak hours and to regular off-season service on longer lines that cannot afford to operate with steam, except in the tourist months. Thirty-Six Persons and Baggage The rail-car in its latest form has a. roomy body for thirty-six passengers, with a baggage compartment in the rear. Pas- sengers enter and leave through doors at the front. The vehicle is propelled by a four-cylinder engine with six-inch stroke, to which is connected a clutch and four-speed transmission. The engine is provided, with electric starter and generator. Up to this point the machine follows stand- ard truck practice. But the four-speed transmission has combined with it a reverse gear that connects with all four speeds. It has a maximum speed of thirty-five miles an hour, and because of its high gearing a bevel-gear rear axle is employed. , A four-wheel pony-truck supports the car at the front, and a single pair of driv- ing-wheels is used in the rear. Regula- tion brake-shoes act on all wheels. The driver’s compartment looks much like that of a motor-truck. Turning the wheel however, does not steer the car, but applies the brakes. When air-brakes are fitted the brake lever is placed on the _ steering column, and the wheel then operates the emergency brake.

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ae oe . eae eae a ee eee our e is the riv- ula- The like heel but , are the December, 1921 What Are Your Chances for Success in Radio? 29 Read these typical romances of four poor boys who found the route to wealth and fame via wireless The brief annais of wireless are packed with the names of celebrities and men of wealth who were ‘“‘just ordinary kids” when the radio bug bit them. Their success is explained by the fact that they grew with the industry—and helped it to grow. And the point for you, reader, is that the industry is still growing, and growing at phenomenal speed. Take, for instance, the dawning oppor- tunities for radio operators on land. Hitherto few operators were needed, ex- cept at sea, but now throughout the world nations are being linked up by direct radio communication. In the United States, police and fire departments are beginning to use radio, as are the forestry service, news- T™ sky is the limit in the radio game. By Armstrong Perry distributing agencies, hotels and business houses. The Federal Bureau of Markets is broadcasting daily reports, the Post- Office Department has a chain of stations for directing its mail-planes, commercial companies are establishing services between cities, and railroads are beginning to use radio for general message service. With every year the field will broaden and so will the need for experts in its various phases. Undoubtedly, however, when the pres- ent shipping slump has passed, the sea will again offer the greatest opportunities and the biggest adventures to the new operator. When he has secured his com- mercial operator’s license from ROM East _ Side schoolboy to million- aire radio engineer in eighteen years—this is the romance of William Dubilier. It all started when, at the age of fifteen, he happened to pick up a book on wireless, by Marconi. He read three hundred pages at one all-night sitting, went to school next day, and that same night attended a lecture on wireless. The door- keeper tried to keep him out, but young Dubilier was already the get-there kind. He sat in the front row. After the lecture was over, he hung around asking questions and making a general nuisance of him- self, until, to get rid of him, the lecturer offered to allow him to carry the apparatus back to the hotel. That simple act decided once and for all his future. From then on, as long as the lectures were con- ducted, Dubilier could be found nightly, first in the audience and later as an assistant to the lecturer, switching lights and arranging the equipment. So rapidly did he ab- sorb the technique, that a few months later Du- bilier was himself deliv- ering lectures for Mar- coni, filling engagements of lesser importance. He was still in school, but he workedwafter hours and pany. It paid alter salary, a ing the latter’s lecture the local office of the chief radio inspector, United States Chamber of Commerce, he will doubtless seek through the me- dium of one of the half dozen great radio and telegraph corporations a job on a cargo boat. However, luck and ability may place a good operator as assistant on a passenger steamship. Now let’s assume that you are the new operator and suppose that you get a berth as the only one on a slow-going freighter. You will discover that the captain bezins to rely upon you for the information that will bring his ship safely to port. In the old days his ship had to plow along until a drop in the barometer showed the ap- proach of a storm. But now your prompt (Concluded on page 80) expenses, but he considered the ex- perience ample compensation. After holding the position five years, he won a gold medal at a World’s Fair for an exhibition of radiophones. At twenty-one years of age Dubilier had such a complete mastery of radio equipment that he was summoned by the Russian government to erect its new high-power station. His fame had preceded him. On his arrival in Russia, this boy, who was no older than many youths in high school, was installed in the royal palace, where for a month he was féted and entertained. The station which he erected at that time was the one that gave the world a jolt a few years later when the Rus- sians, supposedly cut off from com- munication with Germany by a de- claration of war, were found to be attended leetures when he was not giving them himself. — . His next step was to Dubilier pooured bie abcead ears eter phe Joa get a night job ‘with a soe hidsself accistane to fide, news tenting redhe wireless-tel ia com- the great Marconi dur- expert, was entertained by the Czar tour . ‘William Dubilier Eighteen years ago a poor schoolboy, interested in radio; to-day one of the wireless in- dustry’s greatest engineers, the inventor of a condenser that has made his name known throughout the globe, and has earned him over $1,500,000 FE KS a i 4 keeping in touch with the Berlin government by radio. It was not Dubilier’s fault that his station was used in double-crossing the Allies. Having unin- tentionally contributed to the wrong side of the world argument, he promptly struck a blow for the other side. A vital part of every radio trans- mitter is the condenser. The type in general use at the beginning of the war was the Leyden jar, a glass . jar lined with copper. It was fragile, noisy in operation, and gave off quantities of ozone that seriously affected the atmosphere of operat- ing-rooms. The Germans con- trolled the world’s mica supply, so that the Allies could not change to a condenser using that dielectric, instead of glass. One day the Ger- mans awoke to the fact that the Allies were using higher power and longer wave lengths than they had supposed were possible. After the war, it was discovered that among those who had been fighting from behind closed laboratory doors was William Dubilier, whose condenser, con- structed on new princi- ples, had helped materi- ally in condensing the German Empire. Dubilier confesses to thirty - three summers. He can spend the rest of them at Bar Harbor and the winters at Palm Beach, if he wishes—he has the wherewithal. But his favorite resort sum- mer and winter is the little old laboratory on Center Street, New York. | +1 : 1 Te iW $i ,} Bo Bh t age 4 Be

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30 report concerning conditions ahead will enable him to dodge the storm area by a change of course. In the same way, it is predicted, radio will eventually supplant magnetic compass, chronometer, and light- house. Already it is recognized as indis- pensable. At harbor entrances automatic radio transmitters are being installed that repeat their exact positions at short inter- vals. Similarly from the mouths of well- developed harbors radio cables lead in- coming vessels to their anchoring grounds. now being given to civilians by the War Department. From corps headquarters powerful transmitters are sending instruc- tions by radio, while other instruction is given by mail. Your questions will be answered. You will have a chance to be inducted into the signal reserve corps, being called to active service usually for the duration of the short summer encamp- ment. It takes little time to acquire proficiency. In my own case a government license was Popular Science Monthly and keeps cash accounts and other records in proper shape. Mere technical ability counts for perhaps one third in your suc- cess as a radio operator. But the big prizes in radio go to the operators who stick to the game and get into the executive or engineering branches of the business. Scores of important in- ventions are still to be perfected and many a practical operator and experimenter now beginning will reap the cash rewards for these achievements. Not one of the celeb- Again, as a _ radio operator you may be able to get from ships in your vicinity their posi- tion reckonings and so supply your captain with a welcome check against his own compu- tations. Then there are hydrographic reports of submerged wrecks, drift- ing derelicts, and buoys broken from their moor- ings. And usually t vice a day time signals can be intercepted from the government observato- ries in several countries. A Radio Operator's Perquisites All this is routine; but meanwhile, remember, you are visiting interest- ing ports in every quarter of the globe without expense and with accommodations as good as those enjoyed by the officers and first- class passengers. When your ship docks, you are at liberty until sailing- time—and your uniform often admits you to circles closed to the man - in plain clothes. And all the time, too, you are making money. Pay for the beginner ranges from sixty-five to seventy-five dollars a month, while experts often draw more than two hundred dollars. This is in addition, of course, to your “room and board”? and numer-

secured after only four months, and I want to make clear that I was

REFERRING citizenship in the land of Washington. and Lincoln to a life in Serbia as a general in the army, Michal Pupin sold his school- books and an old watch and started for America. He landed at Castle Garden at the age of sixteen, with five cents left in his pocket, and spent it for a piece of pie. He licked a newsboy who jeered at his red fez which a fellow immigrant gave him when his own hat blew overboard. He spent. his first three months in America working on a farm and studying English. Then he got work in New York and saved enough money for an education. He entered Columbia University with two hundred dollars in savings. There he won a name for his muscular, as well as his mental, prowess. As a wrestler he won the college championship. A scholarship took him from Columbia to Cambridge, En- gland. From there he went to Michal Idvorsky Pupin whose epochal in- vention, the Pupin coil, brought him wealth and made him back to the pro- fessorship of mathemati- long - distance cal physics. communication : . possible His most widely used invention is the Pupin coil. Inserted at inter- vals in the line, this makes transcontinental telephony as satisfactory as local calls. With the coming of radio telephony, it was found that the Pupinized tele- phone lines easily took up the human voice, transmitted by radio from Catalina Island in the Pacific and automatically transferred to the land wires, carried it across the continent, and delivered it into another radio transmitter on the At- lantic coast loudly enough to make it audible on board ves- sels a hundred miles or more at sea.

Pupin, wearing a red fez, got his first glimpse of America from an immi- rities pictured on these pages had a better start than you who read this article. The one brilliant quality I have been able to dis- cover in them is the ability to stick to a thing after the keen edge of enthusiasm had been dulled by the inevitable knocks of drudgery. They just kept at it and added a bit of knowledge and experi- ence each day, with per- haps a double dose on Sundays. And _ every little while they have given the universe a jolt by announcing some dis- covery that was right under our noses all the time. It is interesting that, of approximately 20,200 licensed radio operators in the United States to- day, 12,400 are licensed amateurs, leaving a total of 7800 who earn their living by operating. Of these 7800 only thirty- two hold commercial first-grade licenses, and only sixty-six of the seventy-eight hundred hold cargo licenses. Cost of Learning Radio Tuition for a course which will prepare you to pass the Government examination and receive a commercial operator’s license will cost you about fifty dollars. © Books covering the same ground and used

ous incidentals, while many an operator finds opportunities to do other

Berlin, but Columbia called grant ship by many men for self instruction at home in

remunerative work on board. Thus, some write radio articles for technical journals, others compile trade reports for exporting firms back home, and many study the science of navigation. But the “‘wise’’ delve deep into the still unsolved mysteries of their own profession. They know that the big men in radio have all been operators, amateur or professional, who have studied as they worked. For the big men in radio once knew as little about the subject as you may know now. They realized that the time to begin is now, and the way to begin is to purchase a text-book and get busy. If possible, they would advise you to take a course at a good school, locally or by cor- respondence, or else to get a radio man to give you instruction. If his terms are high, help organize a class and split expense. Free instruction, you may not know, is well past the age when men “learn easily.” “But surely,” you object, ‘‘the pro- fession must be overcrowded by now.” It is true that the current industrial slump has temporarily hit radio opera- tors as it has all other classes, but nevertheless the fact is that in good times or bad there is always employ- ment for the exceptionally good radio operator—and by that I do not mean a radio “‘wizard’’; I mean an operator who can send and receive at commercial speed, keep his apparatus in condition and pre- pared for accidents before they happen, respect the laws governing radio communi- cation, handle customers in a courteous and businesslike fashion, and who in case of service at sea—copies as much “‘press’’ as possible for the benefit of passengers and crew, is amiable with officers and associates, place of a school course cost from $2.50 up. Asimple receiving-set, composed of a mineral detector, a single phone and wire for aerial and ground can be purchased as low as one dollar. Better sets, transmitting and receiving, can be built or purchased for from $10 up. A very liberal allowance for putting a beginner in a position to earn some- thing from radio within a year is $100. This is more than the average operator has spent for his education. My own expenses, covering the four months from the time I applied for ad- mission to the East Side Y. M.C. A. radio school to the time I received my com- mercial license were. as follows: A re eee $40.00 Pers fs eee 2.50 ES A er sce 2.25 IRONS» 0's c:0lgl <0 0.66 we aths os W.08 916259 .30 SONS Sees Seer aisisis's 10.00 Notary’s fee for executing oath on license 2

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| : December, 1921 31 He Used His Auto Horn to Get Wireless Message : HEN Roy A. Roy A. Weagant Weagant was still in short pants Soviet onginent of the wns argest radio corporation. is and bare feet, he experimentation has led to mately to feats that have made him famous. Weagant’s outstand- ing accomplishment is eee ae ae ee Ss ae ee eS ee oe built a telegraph set and cut in on a local circuit in his home town in Canada. A discarded hand generator that fell into his clutches peeved him because he had to turn a crank with one hand in order to produce juice to oper- ate his fearful and wonderful methods by which static inter- ference is eliminated and weak signals from far-away stations are amplified wires, and had found absorbing interest in those ether oscillations - that made it possible to telegraph the elimination of static interference. In addi- tion to making it pos- sible to receive signals in spite of atmospheric disturbances, he has also perfected a system of amplification that takes weak signals from distant stations and by means of electrical devices. It was worse without any wires at all. relays makes them loud enough than trying to work a chain pump After graduation, he went to to be plainly audible t and keep your mouth under the work. He’s been working ever The other day,’’ said Weagant, f spout. So he built his own stor- since—working hard; to that “T brought in POZ [the trans- , age battery to serve as a re- alone, or to that and the fact that mitting station at Nauen, just i ceptacle. he always got what he went after, outside of Berlin, about five , Thereafter, he turned his ener- he attributes the suc- thousand miles away] d gies to the construction of a cess that has made strong enough to t motor. He has not finished it yet, him head of the en- operate arelay. Sum- a for before he could get all the gineering forces of the mer-time—worst sea- t parts together he went to McGill largest radio company son for atmospheric e University to study electrical in the world. disturbances. Some- engineering. When he landed a times hard to hear sig- 9 He was mainly dependent job with the Marconi nals. Hooked relay to 0 — upon his own resources. When Company—“‘by going Claxon horn on my car. ‘ grub was scarce, he filled up with after it,’’ as he says— Tisntetn qenietinewiatile The horn started off fl an extra portion of Hertzian he soon became ab- one hand as he operated at thirty words a min- rl waves, now known as radio sorbed in_ research ew Py tanto | Paty 220 ute. I’ll say you could r waves. He had telegraphed over work, which led ulti- lessons in electricity hear the signals!”’ if il : Sarnoff Tried Every Job from Office Boy to Manager . *“ IDEOPLE - think gineer of the Marconi’ ecutive offices told me that that if a man Company andaskedhim _ if I took the job I should be gets a big job he if he needed any men. a sixty-dollar-a-month man must be a wonder. He said: ‘We don’t need all my life. I took the job, and It is not so,’”’ says any men, but we need an in two years became a com- e David Sarnoff, once office-boy at $5.50 a petent commercial operator. u office-boy and now week.’ I grabbed the There was an engine, a genera- it general manager of job. I learned how to’ tor, and a storage battery ° the Radio Corpora- work the telegraph key emergency outfit there. I did tion of America., and learned the code by the dirty work because I “ “T came to Amer- ’ studying at home, nights. | wanted the experience. No- e ica from Europe at eee rere “When one of the tele- body quarreled with me about d ten years of age. I young Sarnoff was graph operators was that. I was only eighteen at lf did not know a word ee ed transferred to wireless, I _— the time. in of English. I started ~ got his job. This was the “By 1912 our company had se in school and worked turning point in my life. four hundred ships and fifty when school was over. I knew that the executives then coastal stations. Men were t, “In 1905 I got a job with the Com-_ in the office knew little about needed as operators, and I was le mercial Cable Company. Having the practical end of radio. The soon appointed an inspector, ” caught the glamour of radio, six real radio men were all down in to supervise their work and Z months later I went to the chief en- the research department, oratthe our equipment. After that I .. shore stations or on the was made successively chief ig ships. IbelievedthatifI inspector, assistant to the 2 could get out of the office chief engineer, assistant traffic 0. atmosphere and into the manager, contract manager, or David Sarnoff practical end of the busi- manager of the commercial de- ; pies’ ‘tis: seen toca ness I could come back partment, and finally general . ine tae. & ee and have something the manager. — a manager : ~ * a other men did not pos- Pap: *7 no pace gee : , : sess. offers such opp ' py 2 epi n Ae A jmr “In 1907 the company America. I have traveled ex- sistence can win out opened the Siasconset. tensively and I know. And station and I applied for there is no profession that a job as radio operator. offers better opportunities My friends in the ex- than radio.”

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$2 Popular Science Monthly Every-Day Wonders Easy Questions About Familiar Things—Can You Answer Them? 1. Why does alcohol cool the body when used externally, and seem to warm the body when taken internally? 2. Account for the appearance of frost on window-panes in winter. 3. What causes clouds to form? How high up are rain clouds? 4. Why should water reservoirs be with- out roofs? 5. How does a fire-extinguisher put out a fire? JN each issue Popular Science Monthly asks ten questions that every reader should be able to answer. Follow them care- fully and you will acquire fas- cinating knowledge about the secrets of science affecting our daily lives. See answers below. 6. Why is a burn from steam at 212° F. more severe than a burn from boiling water at the same temperature? 7. Why does water freeze first in pipes on the top floors of houses? 8. Would the householder who kept a wet cloth over his gas-meter be able to get more gas for his money? 9. What causes the black smudge to form on the ceiling above an oil or gas flame that is not burning properly? 10. Why does blue cloth look nearly black in gaslight? Five Minutes a Day Will Make You Master of These Fundamental Facts of Science Alcoholic Effects 1 When used externally, alcohol makes ® the body feel cool for the same reason that water does. In each case the liquid evaporates; and since heat is necessary to change a liquid into a gas, the water or the alcohol takes the heat from the body, to which it is closest. When used internally, alcohol affects the nerves that control the small blood- vessels in the skin in such a way that they are dilated. This results in a rush of the blood to the surface of the body, which causes a warm feeling. On a warm day it is the heat of the atmosphere expanding the blood-vessels near the surface that gives us the warm feeling. But with al- cohol as the dilating agent, what is actually happening is that the body is being unduly cooled, because so much blood is being brought to the surface of the body. Because of this fact a drunken man may freeze to death despite his first deceptive feeling of warmth. Frost on the Pane > The air you exhale on a cold day cools * to the lower temperature of the outer air. Warm air has a greater capacity for holding water vapor than cold air. Hav- ing been very warm in the body—the body temperature is 98.6° F.—your breath was able to hold large amounts of water vapor, but as it cools it must re- lease the excess water, which therefore condenses into a cloud of vapor. Now think of the window-pane of a warm room in winter. On one side there is air that holds a great capacity for moisture, because it is warm. On the other is the cold air that cools the glass through the inside surface. Inside, the people are living and the moisture that they exhale and the perspiration from their bodies are being absorbed by the warm air. As this moisture-laden air comes in contact with the cold window-pane, it loses its capacity for holding moisture and condenses, forming frost. Height of Clouds 3 As currents of air are heated by the ® earth’s surface, they rise and in ris- ing expand, due to the gradually lessening pressure in higher altitudes. In expand- ing, the air is cooled and condensed into minute drops of moisture, a large number of which form a cloud. Rain clouds are seldom higher than a mile. Why are Reservoirs Roofless ? 4 To allow the oxygen of the air and ¢ the ultra-violet rays of the sun to mingle with the water and purify it. The rougher the water as it is agitated by the wind, the more oxygen will be absorbed. This is the reason why the water in many purification systems is sprayed into the air as a fine mist. How are Fires Put Out ?- In either one of two ways. The more ®* common is by wetting the burning surface to reduce its temperature below that of the temperature of combustion. The second method makes use of heavy gases that form a blanket over the fire, preventing the entrance of oxygen, with- out which a fire cannot burn. Burns from Steam 6 It requires over five times as much ® heat to turn icewater to boiling water and then to steam as to heat the entire mass of liquid from freezing to 212°—the temperature at which water boils. This excess heat that goes into the steam must come out again when the steam strikes a surface and is cooled. It is the presence of this extra amount of heat—known in physics as the “heat of vaporization’’— that makes a burn from steam more severe than one from boiling water. Freezing of Pipes Most substances shrink in volume as ® they are cooled. Water is no ex- ception to the rule until it reaches 4° C. Then it ceases to shrink and begins to ex- pand as it cools to 3°, 2°, 1°, 0° C., when it begins to freeze. As ice it occupies more space than it does as water. Now if water behaved normally, lakes and all bodies of water would freeze from the bottom up, killing the fish. But water near the freezing-point floats to the top because it is lighter and freezes there. The Gas-Meter be As the wet cloth dried, the gas-meter e and its contents would grow colder. Now, most things, including gases, ex- pand when heated and contract when cooled. And when the gas in the meter contracts, more gas flows in to fill the space. This space is inside of a bellows arrangement which turns the dial indi- cator through a series of gears as it dis- charges the gas through the pipes into the room where the gas is being used. There- fore, if the bellows holds more gas, it will discharge its contents and register the same amount of gas on the dial as when the gas was warmer. When Lamps Smoke 9 When a gaslight is burning properly, ® it is being supplied with enough air to burn the fuel completely, which mez be gas or oil or kerosene. The light is usually produced by small particles of carbon coming from the fuel, which have been heated till they glow. But if the air supply is insufficient, a great deal of this carbon will leave the lamp-chimney or gas-tip unburned. This exodus of minute particles of carbon forms the smoke and the smudge that accompany the im- properly burning lamp. Color of Cloth 1 0 When a beam of white light, such as © we get from the sun, shines on blue cloth, the latter will absorb all the colors that go to make up ‘“‘white,’”’ except the blue, which it will reflect to our eye. The cloth then appears blue to us. In the same way, red cloth looks red when the light striking it contains rays that it reflects. Green cloth will reflect green rays, and absorb all others. Now, gas- light is usually deficient in certain colors; especially in the blues and purples. That is why gaslight is yellow. Andso, because there is very little blue from the gaslight: that the blue cloth can reflect, it sends practically no rays to our eyes. The blue cloth absorbs most of the other colors, Sinee practically no light comes to our eyes, the blue cloth appears black, which is merely due to the absence of light.

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December, 1921 ‘S tevgeget im ® ee = ie ie * * ° an SBE Bite seein ss as Sh a SS A ie a a Oe es The famous suspended railroad of Elber- feld. By making use of the space above a canal, the elevated road is made possible ° without obstruction of street traffic Two airplane engines and propellers, one on each end of this car, drives it at a speed of two hundred miles an hour. The car runs on a regular scheduled time between Berlin and Hamburg, Germany Railways of Odd Design from All Parts of the World Autos now furnish the mo- ‘ tive power for the trolleys in Apeldoorn, Holland. Each locomotive .is capable of pulling three cars. Before the advent of these gas loco- motives the cars were drawn by horses Sep Pte ra 4, : | : if hi y if | ak Jil 24H HALL MIN ¢ be j ge IES AN re ee = © This unique torpedo-shaped hanging trolley that does service in Burbank, California, has a seating capacity for sixteen persons. It is driven by a propeller at one end. Such construction is practical only in California’s climate The Malberg railway at Ems is built to conform to the steep slope of the mountainside. The passenger com- partment is built in a series of steps so that the seats e are always upright ia..t) 8 Only intrepid Alpine mountain-climbers ascend the Wetterhorn in any other manner than by this cable railway. The peak of this mountain is over twelve thousand feet high

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cee meen me 34 Popular Science Monthly Getting Thrills out of Made-to-Order Collisions VEN if you don’t own a = 7% electricity and which can be ne" eA" 8 flivver, you can have the pleasure of running into peo- eres. — ple. You can experience the sensation of having your auto- mobile struck by another one, or by two or three at a time. The sport is staged in an enclosure paved with sheet steel and with an overhead covering of heavy steel net- ting. There are parked within this well-fenced lot about twenty-five small cars that look like big tubs set on four wheels. The visitor takes his seat in this round flivver, and grips the steering-wheel firmly. Next he puts his foot on a big button. The effect of this a WSR ME turned on or off at will by the ~ OS: Rta ET RNS O, y electrician at the switch. > AAD J SSS ena The effects might be serious, hi a | i Sen aa were it not that around the bases of the cars are projecting circles of high-tempered steel springs. When the cars col- lide, the shocks are easily broken by the_metal absorbers, The amateur chauffeur has all the excitement without the broken bones that often accom- pany adventures on the road. In the course of a few trips, one may become proficient as a pilot and even steer a strictly straight course. The worst performers in the arena are the ; : ‘ Cars driven from overhead trolleys supply thrills by skilled chauffeurs, who apply pressure is to start things going their eccentric actions. Tempered steel springs on the the principle of steering as in every direction. Each car base of the cars act as buffers they understand it and miss has its own trolley, the wheel the idea. The wheel turns in of which connects with the netting which _ gets the current, causes the machine to go _ the reverse fashion of the automobile steer- forms the roof of the pen. As the metal plunging around the place like a bucking _ ing device, therefore the better driver on the strands are very uneven, and the car has_ broncho. The motive power comes from road one happens to be, the more awkwar¢ no guide for its wheels, the motor, which the overhead screen, which is charged with he is under these abnormal conditions. NTERNAL heat, one of the chief causes of tire destruction, is said to be eliminated by the in- vention of a tire-manufacturing process that embodies seventy- three improvements. Each cord or rope in these tires passed through a machine called the beamer, which takes the place of the more familiar calender in tire manufacture and which coats each strand with an even layer of live rubber. During manufacture the strands sometimes adhere so that before the tread is applied it is necessary to go over the surface of the cords with a steel comb and separate the strands. With this composition, it is impossible for the friction of one strand on an- other to cause heat. tire. As each rope is surrounded by rubber, it is free from the rest during the process of manufac- ture, and can twist and turn and adjust itself individually when the tire is shaped by the air proc- ess. At the same time, a patented device keeps each rope in the finished tire at exactly the same tension, so that every one carries its share of the load. Because of the elimination of internal friction, it is said to be possible to build this tire with only two plies of cords, instead of the customary seven or eight lay- ers of fabric. Long life is expected from the tire as a result of its great flexibility. The inside lining is of rubber— ; The beamer, showing the braided rope a new feature, which the manu- The cords are continuous cord, each strand passing through a rubber facturers say could not be suc- around the bead wire. After the bath and being coated with rubber cessful if internal heat were gener- cord belts have been rubberized, ated, since the inner tube would they are taken to the cutting-room and cut then stick to this rubber lining. .No soap- into strips, each one of which will form one stone or mica dust is required between tire without waste or trimming. lining and tube for lubrication, as the tube There are only two splices in the whole has no tendency to creep. Aft h i Hy . . . mag ng eg ek penny a oh cg — The cords come to this machine in wen 4 A section of the completed tire-carcass 2 belts with a hi f rub i each cord is omy. separated from its side. The ce ten ez at de ig poppet, iby of rubiber-covered neighbor around the bead wire guides co

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December, 1921 ~ Hand Loom Produces Big Cravat Output Ws a simple hand loom, crude in its design, but capable of work that compares with the finest, William Bennett, a disabled sailor, who was formerly a prac- tical scientist and an optician of ability, has been turning out large quantities of silk ties in his improvised shop in the Dugout, a well-known New York institution for ex-service men. Bennett has become so proficient with this loom of his own invention that he is able to weave ten to twelve silk neckties or belts a day. The handiwork is so fine that his product brings the highest prices. Conveyor Handles One Hundred Tons of Flour an Hour ORTABLE - ship-loading units for freight in bags consisting of an electric- ally driven conveyor which can be moved. anywhere about the dock and a tower by which the conveyor can be raised to any height required by the different classes of ships will greatly expedite the stowage of cargo. This new loader discharges the bags into the hold through automatic chutes. Thus the whole operation is made as nearly automatic as possible, and few stevedores are necessary. By means of this conveyor ordinary bag flour is easily handled at the rate of one hundred tons an hour, and by speeding up, an exceptionally efficient crew has Conveyors carry the bags from wharf to ship’s hold at the rate of one hundred tons an hour loaded as much as two hundred tons an hour. In this way great savings were effected, not only in wages, but by cutting down the length of time a vessel must re- main in dock to take on cargo. Breakage and spoilage are practically eliminated, while the cost of loading flour is reduced from $1.25 to*85 cents-a.ton. : Space in New York’s Canyons in the Panic that Never Happens we would happen on one block of New York’s crowded streets if all the workers in the buildings were suddenly transferred to the street? Where Pine Street runs east from Broadway in New York City there is a thirty-six-story build- ing extending along one side of the entire block. The average height of the buildings opposite is twenty-five stories. The total number who go and come to work via Pine Street is sixteen thousand. The average man requires about two and a quarter square feet of standing space. If everybody in these buildings tried to stand in the street at once, the crowd would be packed nine tiers deep and 124 men would be left over. The street would be packed solidly with people up to the level of the windows on the fifth floor. Boxes Fall Thirty Feet Unhurt ¥2 expedite the handling of heavy cases of canned meat between the packing floor and the shipping platforms an American concern has installed a shaft down which the cases can be dropped over thirty feet without injury. No cushions or spring shock-absorbers are used. The air in the shaft is employed as a cushion. The shaft is made slightly jarger than the dimensions of the boxes, and is arranged so that when the cases are dropped it is hermetically sealed at the top and the bottom. The falling box com- presses the air in front.of it and creates a vacuum behind it strong enough to drop it at the bottom without injury. This method has proved three times as fast as » an-elevator. For Drawing Wedged Keys in Transmission Shafts He” to remove tightly wedged keys in transmission shafts without tedious hammering and without danger of scoring or otherwise damaging the shaft surface has long been a problem. The torsion of the shaft, heat, and rust all help to wedge the key tighter and tighter until in some cases it practically fuses with the shaft. Instead of hammering patiently at the thin edge of the key in its slot, a German now uses his recently invented key-re- mover, which, because of its sureness and simplicity and safety, is likely to become a famous tool. The device may be placed over the shaft at any place; it does not have to be slipped over the end—an advantage in the case of a long shaft with several pulleys. When it is fastened to the shaft and attached to the key, the turning of its screw brings a powerful leverage to bear on the key. The upper of the two rollers shown in the illus- tration comes down to the shaft surface like the other as the key is extracted. Rollers are used to protect the shaft. The continued turning of the screw until the upper roller reaches the surface of the shaft removes nearly every wedge. However, if the ‘key should resist this powerful leverage, it does not mean that the remover has not functioned. Either the key is pulled or the pulley is pushed —one or the other. And, of course, when the pulley is shoved past the key, it is no longer difficult to extract the wedge. Raising Figs instead of Thistles RRIGATION and thé tractor turned a California desert that had grown noth- ing but cactus and thistles for centuries into the greatest fig-growing region in the world. The hot sun and the dry air are ideal for this fruit, and the desert soil proved sur- prisingly fertile when irrigation was applied. ation ditches Turning —_— into the irri in a plot of young fig-trees’

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ROTARY BLADES (FORM PORTION OF SCREEN) L4AG0 3 SOM eae? > ae es ie a Sf "ir el # = ~,*8 i Adding Perspective to the Motion-Picture AN interesting experiment has been car- ried out on motion-pictures by a French scientist in which he has obtained some remarkable effects of depth without the employment of accessories beyond a unique screen. In his researches he dis- covered accidentally that if two positive views taken from the same negative and identical in every way are placed one on the other and viewed by transmitted light, the human eye distinguishes between the two views and produces an effect of per- spective. Further experimentation with this phe- nomenon brought out several ways in which the idea could be applied to motion- pictures. One method makes use of a rotating screen as in the illustration. This rotatingscreen, with the segments removed, is placed directly in front of the regular screen. By reason of the persistence of human vision, the spectator is made to see certain parts of the picture in more than one plane and the result is as if the picture itself had stereoscopic qualities. The principal objection to this scheme, and one that would prevent its general use, is the fact that the audience must sit directly in front of the screen and at a cer- tain distance from it, otherwise the dis- tortion becomes so great that the effect of depth is lost. It is expected that further work along these lines will produce a screen or series of screens that will give the de- sired result without limiting the seating arrangement of the auditorium. ALTHOUGH a falling barometer will in- variably give warning of bad weather, the fall does not take place far enough in ad- vance of the rain to be of much value. However, you can tell if the glass will rise or fall hours before the movement occurs. If it is a mercury barometer, look at the top of the column. If level, the glass will be steady for hours. Ifthe top of the mer- cury is concave, a fall is coming; if convex, a rise may be expected. The information can be secured from an aneroid by watching the movements of the point of the indicator when the case is tapped lightly with the finger-nail. A jerk backward indicates a fall; forward, a rise. A secondary screen, made in sections and rotated in front of the main screen, makes motion-pictures appear stereoscopic, that is, they stand out in relief from the backgroun E Popular Science M onthly Auto Crane for Barge Canals f Henny French automobile crane may give a hint of one way in which the United States may make its barge canals profitable. It has been cheap, if slow, to haul by water, but unloading has been so expensive that few business men use the canals, particularly at way stations, where modern handling equipment was alto- gether absent. This crane goes where it is needed, and will handle cargo as rapidly as any hoisting device of its type. The crane revolves in a complete circle on its base, so that material may be taken from the barges and loaded directly into trucks. One engine supplies power to both the wheels and the crane. In unloading, the wheels are locked with the emergency brake and the transmission gears thrown into neutral. The gear-box is unusually large, and contains an additional set of gears attached to shafts operating the hoisting windlass and the turning mechan- ism of the crane. The driver sits facing the rear. His right hand handles the lever controlling the turn of the crane, his left oper- ates the hoisting engine. The pony brake-pedal is under his right foot, and his left is on the regular accelerator. In cranes of this type the cargo is raised and lowered by the tackles. The boom is not moved except to adjust it to the proper height or reach. This is accomplished by a special gear-shift that throws a gear on the hoisting en- gine into mesh. The boom is then raised or lowered to the proper position by A traveling crane mounted on a truck makes for me- the regular controls. chanical efficiency in unloading barges along French ; A a A fifteen-horsepower engine supplies power An engine supplies for crane and truc the power. Elevators that Run on a Curve LEVATORS usually travel perpendic- ularly, but those that connect the East | Boston tunnel with the State Street station run on a curve. Owing to the narrowness of the street at that point it was impossible to build the station directly over the plat- form in the tunnel, a variance of six and a half feet being necessary. . The cars run on hard-wood guide-raiis heavily backed by steel I-beams that are attached to the iron structure. -There are guide-shoes at all corners that accommo- date themselves to the curvature of the rails. The car floors are level at all times and the passengers are not aware of the peculiar path followed by the cars. Each car—there are four of them—will hold fifty people and it will travel at a speed of two hundred and fifty feet a minute. The tunnel station is fifty-seven feet below the street level; thus the six and a half foot curve is a very gradual one. Two somewhat similar elevators have been installed in the famous Eiffel Tower, Paris. The legs of the tower are curved and the elevators travel on curved rails a distance of four hundred and twenty feet, the height of the second platform. THE German alloy ‘‘elektron” contains 90 per cent magnesium by weight, but may be melted without danger of igniting in air as magnesium will. The metal has a tensile strength of from seven to nine tons a square inch, which is increased from eleven to fourteen tons by rolling or stamping. Elektron is proof against gasoline, acid free oils, grease and alkalis. One of Boston’s curiosities is an ele- vator that rises on a curved line. ard-wood guide-shoes keep it level

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December, 1921 Polarized Lig ITH a tube that looks more like a_ telescope than anything else, M. Lam- bert, a Paris scientist, accom- plishes what seem like mir- acles with the dingy works of old painters. He has taken paintings that have become darkened with the dust of cen- turies and with his apparatus has made them appear to the eye as though recently finished. Even the details that seem to have been lost are restored to all their original brilliancy. The painting to be examined is illuminated by a powerful incandescent lamp or an are enclosed in a lantern. The light passes through a con- densing lens and then through a correcting lens, which makes , the rays parallel before they ht Reveals Original Work of © Kadel & Herbert 37 Artists pigments and the-coat of var- nish that covers and protects A highly illuminated painting viewed through a Nicol’s prism is disclosed in all its original coloring pass through a tube containing a Nico]’s prism, which polarizes them. After the light has passed through the polarizer, it is refracted by a diverging lens so as entirely to cover the painting to be examined. A painting may be said to consist of two parts, the layer of it. The varnish turns dark with age and the light re- flected from its surface inter- feres greatly with the light reflected by the pigments of the painting underneath the varnish. When a painting, illumina- ted by polarized light from the apparatus described, is viewed through a single tube containing a Nicol’s prism or through a binocular containing such prisms, it becomes pos- sible, by turning the prism or prisms to the proper angle, to deflect the rays reflected from the varnish, permitting only the unpolarized rays reflected by the pigments of the paint- ing to reach the eye or eyes. In an exhibition given before the French Academy of Science, an old picture of a bouquet of flowers was marvelously revivi- fied. The painting was old and obliterated, but under polarized light the flowers were seen to be roses and hone~suckle, resting in a dark-green glass bowl of water. Print 1500 Photographs an Hour HE professional photographer whc prints negatives by the thousand needs a machine that will do the work quickly. The machine illustrated below has a capacity of fifteen hundred photographs in one hour. It prints from single films, uncut rolls, or glass plates. Shelves above the operating-table contain stacks of nega- tives, while pigeon-holes at the right are intended for the various size sheets of photographic paper. James Flynn, of New York, the inventor, has also devised a one-piece adjustabe mask, which merely requires the turning of a thumbscrew to fit it to any width of border or any size print. There is also an automatic stamping device that changes the number with each print and stamps it upon the back as the print is being exposed to the light. type is of steel and is inked by aribbon. ble-break”’ The The light for printing is provided by four gas-filled in- candescent bulbs of one - hundred - watt capacity. These bulbs are arranged to assure even il- lumination. The machine has a ‘‘dou- contact switch that oper- ates the amber or red pilot light and the printing light. When the paper has been slipped into the mask, the oper- ator presses his foot on a_ foot-tread. This brings a felt pad down on the paper and turns on the printing light. At the same time the steel figures come down on the back of the print and stamp its num- ber. Pressing down the foot treadle will operate any one of the switches and at the same time it will number ‘— the prints — Pere: necessary to adjust... this ‘mask to any size negatives © Floors, walls, and stairway are all of plate-glass. This is ow a movie director obtained the illusion of fairy-land A Plate-Glass Fairy-Land VISION of fairy-land was reproduced in the movies by a scene taken in a setting built entirely of plate-glass. Glass of five-eighths-inch thickness was selected. Working from drawings, a huge force of carpenters proceeded to completely cover a big tank and much of the surrounding studio space, building a floor. At one end of this platform glassworkers simultaneously installed a solid plate-glass stairway. As soon as the platform was in readiness, other glaziers pro- ceeded to cover the entire wooden floor with large slabs of more plate-glass. Plate-glass walls twenty feet in height were set in place along two sides of this ‘“room,’’ the stairway forming a third side, and the remaining side serving as a gateway for the cameras. Beneath the transparent stairway a complicated system of lighting was installed in such a way as to provide a striking picture of flickering lights playing on the waters beneath the glass steps. Where the steps debouched on to the glass floor two wide shallow pools were constructed. Rising from the surface of these pools were eight octagonal glass pillars, each bearing upon its apex a large basket of blown-glass fruit over which the water from the enclosed fountains played. It required two days and nights to film this episode and the whole vision will flash on the screen in approximately three minutes.

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Popular Science Monthly Giant Outdoor Reflectors for Photographing Movies p'? you ever wonder how the movies were able to take such sharp, clear photographs in the shade? Here is one ot the secrets. A gigantic, flat reflector is being used to give the proper high-lights on the face of Corinne Griffith, who does not appear at all embarrassed by the juvenile audience at her love-scene. With these screens the camera man can control the lighting effects out of doors as perfectly as in the studio. They are part of the regular equipment of some film- producing companies for pictures taken under the shade of trees, which are usually the despair of every amateur photog- rapher. The reflectors are made of galvanized tin to keep the light from becoming too bright. The reflection from a plate-glass mirror, like sunlight itself, might produce halation effects and would certainly destroy the illusion of shade when the picture was exhibited. No More Telephone Headbands for Train-Despatchers lag telephonic train-despatching has been in use, many of the men have suffered from ear trouble, some of it due to the pressure of the receivers and some due to static and other noises constantly occur- ring on the line. The invention of a loudspeaker for train- despatchers will do away with all the drawbacks of the head receiver. This loudspeaker is composed of an audion amplifier, an electrodynamic loudspeaking receiver, and a voice-strength regulator. The amplifier allows the most distant sta- tion to be heard with clearness, while the voice-strength regulator tones down the voice from the nearer stations to any re- quired volume. Ukuleles of Steel Will Withstand Hard Usage MONG the latest innovations are steel mandolins and banjos. The instruments are comparatively inex- pensive, since they are pressed out of steel, are as indestructible as anything can be, and the manufacturer claims their tone is excellent. The instruments are light in weight, and should make a useful gift to young children learning to play, who would be almost cer- tain to damage a mandolin of the usual fragile construction. Bumps Help Drive This Bicycle M JEANNET, when he is bicycling in ¢ the environs of Paris, looks for the roughest roads. The bumpier they are, the easier it is for him to pedal, for each bump that rocks his saddle also causes a rod to drive a ratchet gear attached to the rear wheel. _A tilting quadrant on springs is the rear support of the saddle, which rests in front on a lever bar whose fulcrum is beneath the handle-bars. With this arrangement the rider feels only a slight shock on the most uneven roads. a “ sti A tilting quadrant on springs supports this bicycle saddle at the back, resting on a lever bar in front Bungalows Made from Discarded ' Street-Cars | ‘T= housing shortage in Washington, D. C., during the past few years has produced some queer livihg accommoda- tions. Here we have a family who con- sidered themselves fortunate to get a couple of old horse-cars to serve as the nucleus of their bungalow. The abundance of windows practically turns the entire dwelling into a sun-parlor. It is said that many houses of this type have been constructed along the banks of the Potomac. Besides saving lumber, the use of street- cars for side walls reduces the cost of build- ing the remainder of the house. Numerous windows and complicated framing become unnecessary. It is reported that the cars were sold for their value as junk. Holds Lamp-Globes Safely and Insures Quick Removal FyAvine two arms ending in broad, curved shoes which hold the lamp- globe by pressing against it outwardly from the inside, this new lamp-holder is said to be absolutely safe. Turning one knurled screw spreads both these arms apart until the globe is clamped between them and the rim of the fixture. Contact is established all the way around the globe, whereas in the usual three- or four-point holder the few points of contact make the hanging of the globe uncertain, and unequal stresses set up by tightening one screw more than another often crack the globe when it becomes expanded by heat. This trouble is avoided with the new holder, which also permits quick removal. by one man.

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bh huge hangar built at Lakewood, New Jersey, to house the ill-fated ZR-2 may never have a tenant. Whether or not the catastrophe of America’s Brit- ish-built dirigible will have a dampening effect on the further development of lighter-than-air craft depends .on the governmental investigation of the accident. In the meantime the second ship of the same class, which was to be constructed in this country, remains unfinished. This photograph was taken as the finish- The Hangar that Ma ing touches were being placed on the hangar. The shed has a height of 200 feet, a width of 350 feet, and a length of 807 feet. Each of the four doors of the hangar weighs 1351 tons and is opened and closed by two 20-horsepower electric motors. All of the windows in the walls and roof are supplied with special amber-colored glass to prevent the entrance of ultra-violet light rays that would deteriorate the fabric of the envelope. y Never Have a Tenant

Several hundred feet away from the hangar is the hydrogen gas plant where the gas for inflating the big dirigible was to have been generated. Whatever the findings of the board of inquiry as to the structural weaknesses that caused the disaster, it seems to be the belief of military and aero experts that since the dirigible has a definite place in wartime, its development must be contin- ued, but perhaps along slightly different lines than heretofore.

This machine runs special cutting tests on brass rods to determine uniformity of material Taking the Guesswork Out of Brass-Rod Cutting O insure that his brass rod shall be ab- solutely homogeneous and possess uni- form cutting qualities, one founder runs a cutting test on every lot before it is poured. Since cutting qualities of brass depend upon the accuracy with which the mixture of copper and zinc is maintained in the making, a small rod from every “mix” is cut in the special machine shown, and the mixture is changed until the indicator shows the desired cutting qualities. Such careful testing proves its value in screw-machine work, where uniform tough- ness in the rod allows continuous high- speed output and reduces tool breakage to the minimum. The resistance of the test pieces is recorded on the dial of the dyna mometer on a special lathe. California Weed Causes Seventy Punctures a Day EVENTY punctures in one tire in a single day is the unenviable record of a California motorist who recently traveled through that section of the Golden State where the puncture plant is prolific and productive. Introduced as a stowaway in burs in the fleeces of imported sheep, the plant has become well established in cer- tain sections of Arizona and California. It is responsible for 50 per cent of the bicycle and approximately 30 per cent of the automobile punctures that occur in these states. Uncle Sam has been conducting a countrywide weed survey and has ascer- tained definitely that the puncture weed is spreading rapidly. The bur splits at

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maturity into five sections, each equipped with a pair of bayonet-like spines about one quarter of an inch in length. These sections are scattered about on the ground in such a manner that one of the spines always points upward ready to puncture any inflated tire that passes over it.

This Portable Lamp-Guard Is Strong but Light

ARIOUS new features are embodied in this type of portable lamp. For one thing, its strength of construction will ap- peal. A casing completely surrounds the lamp nearly to the base of the filament, and from this casing radiate flat guard strips around the lamp. A special aluminum alloy is used for this metal, so that strength does not mean weight. A bayonet type soéket is used. The wooden handle is easily unscrewed, and when taken off, it facilitates the wiring of the socket. There are no restricted passages through which to thread the wire.

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Milk Aerator and Cooler for Small Farmer HE milk aerator and cooler invented by Cyrus W. MacKenzie, of Waverley, Indiana, combines extreme simplicity in design, operation, and effectiveness in re- sults. The inventor was a dairyman on a small scale, and found that cooling milk by dipping it up and pouring it back into the can aerated the milk and drove out the animal heat well enough, but took too much time. The idea occurred to him that it would be quicker to force air in at the bottom with a pump and let it cool the milk as it bubbled to the surface. His chief difficulty was to devise a pump that would be perfectly sani- tary and easy to wash. His invention is essentially a simple pump that sucks in air on the upstroke, compressing it, and forcing it through the milk on the downstroke. It gives the small farmer the use of one of the improvements usually reserved for the large dairy, and as for ease in operation—the picture shows the simplicity of the machine, such that even a child could handle it. Electric Iron Turned Upside Down Forms Stove H{OTELKEEPE RS will consider the Ger- man who invented this electric iron for travelers an evil genius. In the first place, the iron cheats the house valet out of pressing business and uses up current. The novelty is in the fact that it also may be turned upside down, the handle split apart as a rest, and a meal cooked on it. It comes packed in a handsome case. The whole weight is only about four pounds. Endless Elevator Loads Truck in One Minute ace. up your truck to the coal, sand, or gravel, pull a lever, and this truck- loading machine starts doing the work of four men. The elevator buckets, arranged on an endless chain, fill themselves at the feeding end and automatically discharge into a hopper at the top of the machine as shown in the picture below. The self-feeding devices (operating like two large human hands) dig into the stock pile alternately, and pull in the material against the line of rotating buckets in such a way that each bucket receives a full load. The machine can be operated with either a four-cylinder gasoline engine or an elec- tric motor. When it is properly operated, this loader will handle more than a cubic yard of material a minute. It is unneces- sary to go into fuller detail about this effi- cient machine. The illustration gives a clear idea of its construction and method of loading and discharge. Popular Science Monthly Two self-feeding fingers on this loader dig into the pile at-the rate of a yard a minute Testing the Breath of Bananas in Transit seems that the popular banana con- tinues to breathe after it is harvested, its respiration being greatest at night. The carbon dioxide expended by banana car- goes in ships, trains, and fruit-storage houses must be constantly carried away by ventilating devices, for the sake of the banana’s flavor and its preservation. The device shown in the illustration on a refrigerating car, tests the inside air. Samples of the air are collected through rubber tubing, and the reactions on lime- water noted. Graphite Sorted by Primitive Method in Ceylon © Ewing Galloway -— "THESE Singhalese girls work so cheaply that no machine can compete with them, and about the only way to start a strike would be to insist that they do their work seated in chairs, for they prefer to work in the squatting position which would be impossible to a European. The group is engaged in sorting graphite. Graphite occurs in isolated scales and veins embedded in the older crystalline rocks, chiefly gneiss, schist, and crystalline limestone, although the Ceylon deposits are found in granulite. The rock must be broken into small pieces, examined for in- dications of graphite, and the culls thrown aside, much as slate is picked off of coal in a breaker. The cheapness of native labor is shown by the fact that hammers are used to fracture the lumps instead of breakers, and that the sorting is done by scattering the lumps over the ground instead of placing them on a moving belt. Graphite is found all over the world, but the greatest quantity comes from the island of Ceylon. - oa

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i- n m id he ng ut nd December, 1921 Importing City Lighting for the Country Road | Faprliage ir declare that a large percent- age of night automobile accidents can still be traced to the blinding glare of head- lights, in spite of the improved headlight re- flectors of many types that are being adopted. To eliminate mishaps from this cause, an experimental installation of high- way lighting has been put up on Paradise Road, near Swampscott, Massachusetts. On entering this stretch, the motorist turns off his main headlights, since the road is lighted as brightly as Fifth Avenue. If the experiment is a success, it is ex- pected that the cost of such lighting im- provements will be apportioned as part of the expense of highway work. The light unit consists of a nest of re- flectors, one within the other. Two of A reflector that gives light on the road only where these direct the light toward the roadway at an angle of ten degrees below the hori- zontal. An opening just below the tip of the lamp also allows some light to be directly on the road immediately beneath the installation. The bracket holding the reflector is adjustable, so that the fixture can be mounted on poles close to the road, or on locations some distance away. Machine Measures Leather Area LLUSTRATED below is a machine used to measure the area of hides, It will make allowance for the uneven edges of the skin, and will even subtract the area of a hole in the center of the hide. As the skin is drawn through the machine, the friction turns a series of wheels that will not move except when they are in contact with the leather. The rims of the wheels are of known © Kadel & Herbert The hide is fed into this machine and numerous fingers follow the contour, measuring the surface width and circumference, and it is com- paratively easy to translate automatically Into terms of surface area. Hides are sold by the square foot, and a machine like this is used to determine the amount tobe paid. 41 at EL gM, eX Fade ikon Fire-Truck Helps Out in Water Famine THUNDERSTORM that burned out the motors of the pumping station at Clintonville, Wisconsin, totally cut off the city’s water supply. In the emergency, a fire-truck supplied water service until the repairs could be made. The truck, which was equipped with a five-hundred-gallon pump, was located near the city well. A double line of hose was run to the pipe lines inside the pump- ing station, and although the water tower which can be seen in the background of the illustration is 164 feet above the pumping station, the fire-truck was able to fill it. Gas-Bombs Reduce Rioters to Choking and Tears A handful of ‘the tsar. bombs that effectively dispersed the mobs ‘T° EAR-GAS” bombs with which various police departments are being equipped for use against rioters and unruly mobs, are the invention of Major Stephen De La Noy, of the United States Army. This is an ap- plication of a war device to peace-time uses. During the war, shells filled with lachry- matory gas were “‘sent over” by the hun- dred to make the enemy blind with weep- ing and distressed with coughing, choking, and sneezing. Tear-gas bombs will not only check the advance of a wild mob and stop rioting, but will be invaluable in “smoking out” danger- ous criminals barricaded in houses. Witha puff of tear-gas near him, the worst of desperadoes is no longer dangerous. One little bomb may reduce the most hardened criminal to a weeping, cowering wreck. Two hundred members of the Philadel- phia police force were the first to experi- ment with lachrymatory gas. These stal- warts were organized into a rioting gang and were dared to rush past a given point, within throwing distance of five A. E. F. veterans. None of the cops got past the point, excepting those who rolled on in paroxysms of sobbing. There are no. after effects from a dose of lachrymatory gas, but during its half hour of efficacy, it chokes and nauseates as well as produces floods of weeping. The Smallest Ornamental Tree in the World APANESE gardeners prune, starve, and potbind trees to dwarf them. Conifers are best liked for this develop- ment, as the hard woods are not so tract- able. The method of stunting is said to be secret, the heritage of certain families for centuries, but two explanations are offered. One, from Japan, is that the tree seed is placed in a half orange, its roots being clipped off when they bore through, the skin finally being varnished and the bound roots placed in a pot. An American arboriculturist suggests that the trees are propagated in high alti- tudes whose rarefied air produces stunted growth; strong pruning, lean soil, and pot cultivation also being resorted to. Japan offers many varieties of dwarfs, but the popular kinds of these tiny trees are: bonsai, perfect miniatures; kengai, with long branches; nazaschi, with ‘“‘weeping’”’ branches; zikki, with geometrically ar- ranged twigs; and neagari, with exposed roots. A stunted tree produced by the secret methods of a é

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BUFFER SPRING / % ~~ , \ AIRPIPE * Completely Automatic Car-Coupler — years ago John \F Genin, of St. Albans, Ver- mont, set to work to make an automatic railroad coupler that would make it unnecessary for the brakemen to crawl under a car to connect the air and steam lines. Recently his invention was perfected and tested by the Canadian National Railroad, which endorsed it very highly. The coupler is an adjustable plate so constructed that a car equipped with an automatic coupler can couple up to one that still has the old-fashionei mechanism. It makes the con- nection of air-brakes, steam, and whistle lines all automatic and does not require the attention of any one during the process. Horizontal Forge Press Economizes Space NE of the features of this horizontal forge press is that it economizes in overhead space, which is sometimes a necessity and always an ad- vantage in small works. The soft metal in molds or matrices gets the full force of 10,000 tons upon it and the forge quickly turns out axles and similar products. Only the ma- trix need be changed for a varia- tion in the forging. This machine is proving a great success in Germany, where, it is said, novices are operating it. Many German mechanics were killed in the war and sim- ple machinery is in demand. The operation of this horizontal forge press is so simple that a mere novice is able to run it Inspecting High-Tension Pole Lines AN inspector of high-tension wires must be able to walk + + over railroad-ties and other uneven places without low- ering his eyes from the wires overhead. An error in judg- ment on his part—the neglect to notice a rotting cross-arm or a broken insulator—might involve the failure of this high tension transmission line, with a temporary ebullition of fireworks and subsequent darkness throughout the city. There are some peculiar requirements for his work. He must be able to determine the condition of telegraph-poles at a glance, and have them replaced before they blow down in a heavy storm. He must be able to gage the rate of growth of various kinds of trees so that he can have them trimmed be- fore they interfere with the wires. Most difficult of all, perhaps, a wire inspector must remem- ber every minor defect along miles of line, to avoid reporting the same breakage twice. His route is arranged so that the whole line ‘is inspected at least once a week. Cracked in- sulators and warped cross-arms give the most trouble, as any electrician with telegraph wire experience will tell you. Popular Science Monthly © Keystone View Com- pany A New Way to Bob . the Hair It isn’t the easiest thing in the world to cut hair so that it will hang evenly all the way round, but with the little guide shown above the hair is trimmed to the proper length. The de- vice is an improvement over the traditional soup-bowl used by our grandmothers for this oper- ation. The guide is made of heavy cardboard, and can be cut out at home. It is a boon to the mother whose little daughter dislikes a trip to the barber’s chair. Older girls who want to bob their own hair can do it in the same way, but to para- phrase Punch’s famous advice, the wisest counsel for those about to bob the hair is—Don’t. The Tower Bridge in Valve Fittings HIS window-display model of the Tower Bridge in Lon- don was made of valves and fittings, with only a postcard view of the original for a guide. In it there are 15,358 pieces taken from regular stock, com- prising 230 different kinds of elbows, tees, crosses, nipples, and valves, and 16,251 joints were used to make up the fit- tings. It is worthy of note that not one left-handed thread was used in the entire structure. The model is approximately 19 feet long by 11 wide by 4 feet high. The draw can be raised and lowered, and the colored lights on the pipe model signal traffic exactly as do the warning lights operated on Tower Bridge. Not one left-handed thread was used in this model of London’s Tower Bridge

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December, 1921 Primitive Methods Are Still Used by the Japanese in the Manufacture of Silk 43 The boards in this il- lustration are covered by silkworm moths ready for mating. Each female moth lays from two hundred to five hundred eggs in the spring A corner in the silk-weaving room. These girls weave beautiful designs with the primitive foot-power looms, yet the high degree of dex- terity demanded of the work- ers calls for a wage equal to about one fifth of what the similar -task would bring in America The completed cocoons are placed in a basin of water and then unwound on to reels. Close watch must be kept for uneven strands and strands par- tially eaten through This picture shows the primitive machinery that Japan is content to use in its manufacture of silk. As a rule, the weaving is carried on entirely by foot-treadles At frequent intervals during the life of the silkworm the beds on which they are placed must be changed. The man at the right is placing a bed of worms back on the storage shelf Feeding mulberry leaves to the silkworms. The worms take about a year to hatch and after they emerge their appetites are unbounded. During their life they eat their own weight in mulberry leaves Fe pate aae eT ee Sane eee ee ore cease | i ) i] V4 io ] F y ih t y ¢

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Popular Science Montaly The Tire Is Inside the Rim ere on an entirely new principle, this patented automobile wheel carries its pneumatic tire inside the rim, where it can- not be punctured or cut. As the illustration shows, the new wheel consists of an outer tire of solid rubber on a flexible metal rim supported by a small, fully inflated pneumatic tire attached to a PPR SRE

A steel disk covers the wheel, keeping dirt and oil from the inner tube The inflated inner tube serves as a cushion for the outer rim

When a car of grain is to be sampled, this testing-rod is thrust down through the load. When withdrawn, the compart- ments are filled with specimens from different levels Grading Wheat in Carload Lots second rim bolted to the hub. In service the whole wheel is pro- tected by a metal cover that guards the tire inside even against dust and sunlight. The inflated tire “rides” in fork-shaped grooves that connect it with the outer rim. The inventors claim that this arrangement combines the wear-

Fy UNDREDS of tests by the Federal Bureau of Markets prove that there is a vital relation between the grade of wheat and the yield of quality flour that can be milled from the grain, but it has been difficult to the point of impossibility to locate a small pocket: of low-grade wheat hidden somewhere in the contents of a loaded freight-car. This trouble has been overcome by the in- vention of a sampling-rod that enables wheat to be taken from every portion of a carload in a short time, and by running a test on samples taken from fifty different points, the investigator can get a reliable idea of the average grade of wheat in the car. The grain probe has ten compartments, independent of each other, which are opened and closed by turning the handle after the probe has been plunged into the grain. Five probes are made and the samples placed on the cloth. Dirty or faulty wheat loaded in any portion of the car can be easily discovered. If none is found, the cloth is folded from the four corners, which thoroughly mixes the samples, and the grade of wheat is then determined. Thus the Bureau of Markets can determine the quality of the entire carload by one test. Farmers get a better price for clean wheat, and where these tests are in use, they find it profitable to store the grain carefully. Keeps Airplane Engine from Freezing ing qualities of the solid rubber tire with the speed and comfort of the pneumatic. It was developed for use by trucks over rough roads that cut pneumatics to pieces. Creeping has been elimi- nated, and as the inner tire never comes into contact with the road, it will hold its air for a long time and wear almost indefinitely. The outer rim is made of steel and is sufficiently flexible to keep from being permanently deformed or dented by the shocks of driving over rough roads. The weight of the car is borne by the forks, and is supported by the inflated tire. Roller Coaster Built by Children The track is uneven and the car inse- cure, but the boys who built this roller coaster get more fun |), from it than if it |<) were perfect

This simple heater keeps the airplane en- gine from freezing by circulating warm water through it OLD weather no longer has any terrors for the airplane owner whose hangar cannot be heated in winter. An airplane engine-heater, tested by the Army Air Service, that maintains a constant circula- tion of hot water for twenty-four hours will keep the radiator from freezing. The stove consists of a twenty-four-inch vertical coil of three-quarter-inch copper pipe, surrounded by a sheet-iron jacket; a burner in the base, two fire-screens, a fuel tank, gasoline feed-pipe and connections; and inlet and outlet water-pipes from the oil to the top and bottom of the radiator. The circulation is thermosiphonic. The burners require a pint of gasoline an hour. Care should be taken in lighting the stove, and the fire-screens above the burner must be kept clean, for soot deposited at this point is liable to cause trouble. In starting the stove, the feed-pipe is filled with gasoline, the tank put on, and the main burner valve slowly opened. The “gas” then fills a cup. When nearly full, the burner is closed, the fuel in the cup lighted and allowed to burn out. Then the main valve is again opened, at the same time lighting the burner with a match. The door uf the heater is tightly closed and the valve at the bottom of the supply pipe is then put at a quarter turn. The stove will burn with- out attention until the fuel is exhausted. ~

"THREE of the cleverest boys living on the East Side of New York City con- ceived the idea of making their own ‘roller coaster from odds and ends found in back lots. The enterprise fitted into the imaginations of other youngsters and soon boxes and boards were collected in sufficient quantity to construct the coaster. As completed, the coaster is two hun- dred feet long and runs down the natural slope of a hill. A packing-case mounted on roller-skate wheels serves as the car. The track is not smooth, but that only adds to the exhilaration of the slide.

It is not uncommon for glassblowers to drink from twenty-five to thirty quarts of water in the course of a day’s work, but his- tory mentions a baby of three who used to drink two pailfuls of water a day. She grew up, apparently quite healthy, gradu- ally increasing her quota to four pails. Dannlne Saenne Bi anthln

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ound CC ~~ sv 8 ral. ily of 1iS- to she du- December, 1921 Mutilating Plants to Make Them Grow RUIT and flowers are worth more than wood—so English botanists cut rings in the bark of trees in order that more of . the nourishment rising from the roots may be diverted to the fruit. A shallow ring is cut with a sharp knife just through the outer layer of the bark, Great care is taken not to cut into the Deliberate mutilation of plants in- creases their growth and productivity wood, for this would kill the branch. The cut is then bandaged. The result is that_ the sap cannot be absorbed by the bark, but passes on to the buds. At the Ashton Experimental Station in Bristol, England, it has been proved that in skilful hands this treatment makes the bark thinner, and greatly increases the size of the leaves and the productivity of the tree. | MOTOR-DRIVEN CENTRIFUGAL PUMP A 3 per cent solution of hydrochloric acid forced through the tubes of surface condensers effectively loosens the boiler scale and makes a com- paratively inexpensive job of cleaning the boilers Hydrochloric Acid Removes Boiler Scale POWER-DRIVEN mechanical cutter is usually employed to remove scale from the tubes of surface condensers. It is admittedly not the best method, for in ad- dition to the expense of the operation, tubes are liable to be broken; but engineers hesitate to use a dilute solution of hydro- chlorie acid, in spite of the theoretical ad- vantages of this process, because they fear the possible action of the acid on the metal parts of the condenser and tube packing. In the opinion of Norman G. Hardy, chief mechanical engineer of the Arizona Copper Company, this danger may be over- come. He has used acid for cleaning con- This Oil-Tank Was WO hours and fifteen minutes sufficed to move this water-tank from Engle to Cutter, New Mexico, over the tracks of the Santa Fé. The tank is 45 feet high and 24 feet in diameter, and weighs 65,000 pounds. The difficulty of the job was increased con- siderably by the fact that there are two one-degree curves in the tracks over which the tank passed, in both of which the outer rail is slightly banked, the elevation being two inches in one curve and two and three quarter inches in the other. Great care was necessary at these points to prevent the tank from swaying and overturning. The tank was cut from its concrete base, raised upon jacks, and a spur track built beneath it. It was then lowered upon a flat-car, which was strengthened by bridge-stringers placed lengthwise on the floor. To prevent swaying, this car was then securely fastened to another car loaded to capacity with broken stone. This twenty-four-foot pe pee miles over a railroad track of or Moved Nine Miles forty-five feet in height, was hauled nine inary width at the rate of four miles an hour denser tubes for two years with excellent results by the method illustrated in the illustration. He calculates the saving effected in cleaning a 7600 square foot con- denser amounts to $893.41 over mechanical methods. A 3 per cent solution is pumped through the condenser from four to five hours, after which the loosened scale is washed off with a wire brush and a hose. To protect the metal parts, the water-boxes, heads, and tube sheet are first cleaned mechanically and then painted with two coats of roofing cement. Cover plates and gaskets are next fastened over the water inlet and outlet, with capscrews tapped into the water-box. The heads are then replaced and the ap- paratus connected up as indicated above. A two-inch brass centrifugal pump with a directly connected motor drive is used to circulate the solution. Caruso Candle Will Burn in 6921 A CANDLE weighing a thousand pounds, that will burn twenty-four hours every second day of November for five thousand years, is a memorial to Caruso that will be presented by Italian orphans in New York City to the Church of the Madonna di Pompeii, Naples. Caruso was born in Naples on November the second. This candle will burn 120,000 hours consecutively, or for almost fourteen years. The figure of Christ will be modeled in wax on the candle’s base, and the name of every orphan contributor will be imprinted on the stem. The wax was contributed by the candle- makers, Antonio Aiello and Brothers, of New York. This memorial is a grateful acknowledgment of the singer’s contribution of ten thousand dollars a year toward the sup- port of the orphan asylum in New York City.

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46 The First Large Suspension Bridge to Be Built since 1909 In may re suspension bridge, a temporary pathway is first strung across fort PANNING Rondout Creek, a tributary of the Hudson River at Kingston, New York, is the first large suspension bridge to be erected in twelve years. The last one of any consequence was the Manhattan Bridge over the East River, New York City, which was built in 1909. The Kingston bridge is made up of two towers, 168 and 185 feet high respectively, from which cables 1185 feet long are hung. The length of the roadway is 1145 feet, with a clearance of eighty-five feet above the stream. Dropping from the cables are the ‘“‘suspenders,”’ which support a con- crete roadway twenty-two feet wide and a footpath seven feet wide. The supporting cables were built up in place, two strands at a time. Large reels of hard-drawn steel wire, three sixteenths of an inch in diameter, were placed at each corner of the bridge and the free ends fastened to the anchorage shoes. A re- volving wheel on an endless moving cable, shown in one of the illustrations, was then slipped in the bight of these wires and drew them across the bridge gap over the im- provised suspension path. On the opposite e movement of workmen and the wire-stringing machine shore the loop of the wire was attached to the anchorage, and the traveling wheel sent back carrying a bight of wire from the other reels. This operation was repeated until four- teen ropes, each con- Popular Science Monthly With one end of the wire anchored, this traveling wheel carries one loop across to the other shore and returns with another the cable was compressed in a powerful screw clamp with a circular opening which forced the wires into the form of a round rope. They were then wrapped con- centrically with steel wire, as a whipping is put on a fishing-rod. An electrical winding machine was used to put on this whipping with the requisite tightness. The last step in the construction was to clamp the sus- penders over the finished cables, and erect the steelwork and the roadway in the cus- tomary manner. It would be quicker and easier to form the cables of suspen- taining 282 wires, had been built up. More than 913 miles of wire was consumed. After the cables were com- pleted they were lifted into place in their saddles on the tops of the towers, and carefully § ad- justed until their sag, or versed sine, was the same as that of a guide wire. At this stage the cables con- sicn bridges out of twisted wire ropes, but for an _ equal weight and diameter acable of parallel strands is at least 10 per cent stronger. It is also easier to detect and cut out any imperfections in the wire when it is built up strand by strand. In spite of this apparently slow process, the Kingston sisted of a loose bun- dle of parallel wires. After the engineers had satisfied them- selves that the sag was correct, and that the strain on every strand was the same, A near view of the pathway, with the wire reels showing at the extreme right year. .... stone was laid in De- cember, 1920, and it is expected that the bridge will be ready for traffic any day. bridge will be fin- ished in less than a The corner- Plastometer — es Ability _ Contour of Head $ ew young woman in the illustration, with what appears to be a combination sextant and double telephone receiver clamped to her head, is having her inner and outer self measured. A Berlin artist, Dr. Burger, having become intensely interested in phrenology, along with his passion for modeling, invented the “soul and body caliper,” which is called a plastometer. It is said to regis- ter scientifically the meaning of every cranial depression and protuberance in calibrated de- grees of physical and mental weaknesses and powers, and inherent intellectual and manual proclivities, with a sureness that would require months of obser- vation by any other method heretofore known. It is said that the face and head comprise a human dial, which the plastometer can inter- pret with unerring accuracy. One bump tells whether you are musical, another if you are com- bative, another if you have great vealed and translated b linguistic faculties. panos Mis. .5 These bumps have long been known to phre- nologists, but they have never been able to make readings with the precision of the plastometer. And Dr. Burger goes further than the manual phrenologist by reporting that signals in the surface of the cranium warn of approaching disease and in- capacity. NATIVE American weeds might produce three hundred million pounds of rubber a year if it were commercially profitable to exploit them. Dr. H. M. Hall, who has been investigating possible sources of native rub- ber, believes that the common milkweed and the aster family of plants both produce a rubber sap. The Chrysothamnus nau- seosus, or rabbit plant, is a prom- ising species that might be used for a source of rubber of excel- The bumps and hollows of the patient’s — are re- this strange-looking instru- ment called the plastometer lent quality in case emergencies should close the usual channels of import. — FR mm *#@4r ot Cot FS

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tT ort wwe NS we FS Ss Recto e ~~ S ~- t¢ t ~ i, Ei i 0 a to eh ct ew cc = & December, 1921 ‘ 47 Pumping a Million Tons of Coal from River-Beds Susquehanna River takes coal rejected from mines and makes it better than colliery’s best T= Susquehanna is the world’s champion ‘“‘coal- bearing” river. It bears this coal not in strata, but in the lumps and dust that are ejected from Pennsylvania’s great. anthracite mines. This is “reject” coal, and it is esti- mated that the rejects from the 350 principal collieries in the state amount to nearly 500,000,000 tons a year, much of which is dumped into streams of various sizes that pass the mines. Now here’s where nature jeers at the miner. It ac- cepts all this anthracitic waste in its rivers and promptly proceeds to carry Huge pumps operated from flat-bottomed it downstream. In_ the stream-conveyance it bumps this coal about. The opera- tion has come to be tech- nically known as “‘jigging’’ or “riffle-washing.”” When the waste coal has been jiggled for from fifty to a hundred miles, it is found to be a much better fuel than coal fresh from the breakers. Besides rebuking man for his wasteful methods, nature also transports this enor- mous bulk of millions of tons of coal, free of all cost, to great mill centers, where its easy extraction cheats the collieries out of | the salé of their rail-transported product. The method of mining this dump coal from Pennsylvania river-beds is by the use of ordinary sand-pumps and clamshell dredges. The pumps and dredges dis- charge on a screen which permits mud and sand and water to filter back into the river, but retains coal. Thirty-three years ago “river coal” was first extracted by a sand-pump with the idea of its being used.. But it was re- jected because of its high ash content. In many intervening years “river coal” was sold by a few sand-pump firms for from fifty to sixty-five cents a ton, some- times even lower, the buyer doing his own hauling. Then a state geologist became interested in the slowly growing coal- pumping industry and made tests. Coal pumped from the Susquehanna at Harrisburg averaged from 15 to 18 per cent in ash content. The same anthracite from the colliery breakers had from 18 to 30 per cent ash content. The dump coal had turned out to be better fuel than the qual- ity grades fresh from the mines! Volume for volume, it was higher in thermal units than accepted coal—just because it had been dumped into a river and allowed to jazz downstream! An average analysis of river coal showed this splendid com- position: Moisture... ieee cabs bese adie 3.42 percent Volatile matie®. .53).054.%s.- a Fixed carbou......s.ceeshes as, = Bh... ..s.s0.03-0's eh ene eee we 8S British thermal units....... 12,250 There was a quick right-about, of course, and a big market was at once opened for river coal. During the years of 1919 and 1920, the yield of coal pumped and dredged from Pennsylvania river bottoms was more than two million tons for each scows lift up the wet coal from the river bot- tom and deposit it on a screen, which allows the mud and sand and water to sift through the mass, leaving only the pure coal, which is much higher in thermal units than coal taken straight from the mines year. The Susquehan- na and its tributaries had the greatest yield —1,586,000 tons for 1919, and approximate- ly the same amount for 1920. At Harrisburg alone 400,000 tons are being extracted yearly. A little creek called the Shamokin is yielding 750,000 tons a year; 235,000 tons comes from the Schuylkill, 120,000 from the Lehigh. A state geologist poking around in the little Shamokin creek, found one bed of 2,000,000 tons, a thousand feet long and ten feet deep. He mentioned this casu- ally in a: recent lecture before Philadel- phia coal experts to convince them that the yield of river coal is by no means being exhausted. Pessimists have said that the supply would last only from four to ten years longer—this term depending on the degree of pessimism. ‘But other experts reply that there are not only twenty-five to thirty million tons still resting in the river- bed, but that the dumping is continuing at the mines. Before the pumping and dredg- ing of the coal had become a great industry, the waste coal cost the mines a great sum in These coal-pumping dredges are reclaiming mil- lions of tons of low-priced reject coal annually yearly indemnities to farmers. The river- beds were filling up with coal, and during the rainy seasons overflows were frequent. However, farming land is no longer spoken of as being ruined by the anthracitic sediment. Instead, railway-tracks have been laid out on these flats and the silt is shoveled into coal-cars as soon as a provi- dential flood comes along. With wings folded back this five-hun- dred-pound oongn takes up' no more room than an automobile |. yore with wings that fold back against the fuselage so that the plane may be stored in a Ford garage or any barn that will house a two-horse wagon, this new ma- chine, designed by A. K. Longren, of Topeka, Kansas, may prove the Ford. of the air. It is one of the smallest practical air- planes ever constructed. The total wing spread is about nineteen feet, and when folded it measures only nine feet wide, seven feet tall, and nineteen feet long. To prove that the ability to fold the plane was not gained by any sacrifice in strength, on its initial flight this plane was put into two tail spins, twelve loops, and a barrel roll, which shows that its wings are as strong as those rigidly connected to the fuselage. Although the plane weighs only five hundred pounds, it will carry a useful load of the same amount and is equipped with a sixty-horsepower motor. Its outstanding feature is its ability to take off and land in confined spaces. It will leave the ground after a run of 125 feet, and land in seventy-five feet, so that it may be brought down on a field of ordinary size, and is independent of elaborate landing- fields and hangars. This makes it an ideal machine for farmers and professional men who are awake to the advantages of the air- plane for inspection trips, patrolling forests against fire, and for long flights to examine property far from ordinary lines of com- munication.

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Basset Process Makes Steel Direct from Ore RODUCTION of steel direct from the ore in five hours is the revolutionary accomplish- ment of the French scientist, M. Basset, whose process is now said to be developed on a com- mercial scale. For years metallurgists have dreamed of a direct steel process, eliminating the spectacular Bes- semer converter. Numerous methods have actually been tried out, but the Basset process is the first one for which really sweeping claims of success are made. In the most efficient blast- The hot blast is charged with a meas- ured quantity of powdered coal dropped through the small pipe furnaces far more coke is supplied to the charge than is theoretically needed to re- duce the iron ore. The result is that the molten iron, which dissolves carbon almost as water will dissolve sugar, takes up an excessive amount of this element, which must be burned out of the pig iron by the open hearth or Bessemer process before steel can be made. In other words, the iron is first carefully supplied with too much carbon, and then the excess of carbon is laboriously burned out. This takes time and it costs money. Basset has apparently solved the prob- lem by mixing the iron ore with limestone in arotary furnace. There is no coke in this charge, as is the case in the usual blast furnace. Instead, the carbon is supplied as finely pulverized coal, which is carried into the furnace by a blast of air heated to - 1800° F. The quantities of air and coal blown through the ore are carefully regu- lated, so that the combustion in;the fur- nace is incomplete. Even after all the oxygen is taken from the ore, the coal is only half burned. The gases given off from. the ordinary blast furnace are largely: carbon dioxide, CO,. The Basset furnace produces only carbon - monoxide, CO, which will not re-oxidize the metallic iron. The high temperature of the Basset blast is obtained by passing the air through brick retorts that are heated by the gases given off by the furnace itself, which proves that the combustion is only half completed in the presence of the iron. Nevertheless, the heat produced in the furnace is amply sufficient to melt the iron, which is poured into molds in the usual way. When a pound of carbon is burned, about a thou- sand heat units are emitted in forming carbon monoxide, and nearly two thousand Brick retorts for superheating the air blast to 1800 degrees. hey are fired by the carbon monoxide given off by the ore furnace more when the monoxide burns to form the dioxide. By making these two steps take place in different furnaces, M. Basset re- duces and melts the ore without danger of re-oxidizing it, and still gets enough heat energy from the pulverized coal to heat his air blast. The new process will produce steel from ore in five hours. With the blast furnace it takes thirty hours. Reports from Paris assert that in addi- tion to the saving in time effected, iron can be produced 70 per cent cheaper than in a blast furnace, and 80 per cent is saved in the cost of installing the plant. The cost of subsequent operations in the manu- facture of steel is also reduced, as the exact control of the amount of carbon supplied to the metal and the heat of the blast allow steel to be withdrawn directly from the furnace. Popular Science Monthly There are still many skeptics among metallurgists as to the commercial possibilities of the process, but M. Basset expects from it far-reaching benefits in France, since a poorer and cheaper grade of coal can be em- ployed in smelting, and France will be enabled to make steel with the coal found within her borders, instead of importing coking coal from Germany and England. Here in the United States, we have an abundance of good coking coal, and the steel oper- ators are naturally loath to Lined with refractory clay, the re- duction furnace tilts to pour off the molten iron and slag abandon their expensive blast furnaces until it becomes necessary or profitable for them to do so. In the West, however, where good coking coal is scarce, a success- ful process of this kind might help to build up a locally profitable steel industry. Printing Our Own Postage Stamps HAvE you received a piece of ‘‘metered mail’ yet? You are certain to before long, for the newly invented postage meter is being adopted by many large concerns to speed up their outgoing mail. It will post- The desk model postage printer takes up but little space and is hand- operated mark, stamp, seal, count, and stack mail at one operation, and at the rate of forty pieces a second. Instead of using postage stamps, the machine prints the date, the time, and “Postage Paid” on the envelope, using ink of the color of the stamp—green for one cent, red for two cent, and soon. Yes, but how is the Government sure it is being paid This is the style of postmark printed by the postage meters if no stamps are used on letters and parcels? The meter attached to the machine is taken to the post-office, a payment is made, and the clerk unlocks the meter with a key in his possession. He sets it to print as many “Postage Paid” lines as you have purchased stamps and no more. After the last impression, the meter locks and must be taken to the post-office again. For large business houses the motor- driven machine will postmark 250 letters a minute »

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er- ces for er, SS- ild errregde ls? is is ou re. J ks in. December, 1921 49 The Perfume Industry of France Where the rose, jasmine and cassia are robbed of their odors yee ee Photographs Ewing Galloway ae © The receiving-room of a perfume factory, where the freshly picked leaves of the rose and other flowers are dumped before being thrown into the huge cookers shown at the left of the picture F A corner of the distillation room, where the flowers The mixing-room, where the attars are mixed in the are distilled with water or superheated steam. The ~ proper proportion to obtain the exact scent. Most method of treatment varies with each flower or herb of the natural perfumes are mixed in solution with that is used alcohol Some perfumes cannot be obtained by distillation, but are gained by maceration or inflowering, both constantly in the laboratory to be certain that the processes requiring a mixture with fat, and the per- final perfume does not vary, the most careful meas- fume is then squeezed from the flower or fruit by uring of ingredients never producing the same these hydraulic presses strength twice

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i i} ‘i f i} i 4 ; | } 1 pedro ge 50 Music Now Comes on the Movie Film USIC is always served with moving-pictures, but if it isn’t appropriate, it may easily spoil the effect of a picture. We can now have music and pictures combined on a film in the manner shown below. As the film is made up, music is selected and is repro- duced along the lower edge of each section of film. Then, when the picture is projected on the screen, the music will appear at the bottom, where it is in full view of the man at the piano. Enlarged Phonograph as a Vocal Sign-Post it is the custom in England to drive out to the Derby to see the races, and in the past, parties sometimes lost their way over unfamiliar roads. An English newspaper decided that the ordinary guide-posts were not enough, and installed a loud-speaking phonograph at every important corner. The machine depicted shouted “To the Left! To the Left!” all day long. The loud-speaking attachment on the phonograph made it sound as loud as a man can shout. The invention was developed during the war to permit aviators to shout instructions to troops, even when flying a thousand feet above the earth. In the September issue, Popular Science Monthly printed an article on the inven- Popular Science Monthly Here Are Two Drums in One Tos orchestra and band members this two-in-one drum will be found conve- nient. Not only may a smaller drum be placed into the larger one, but parts making up the drummer’s trap supplies may also be placed inside. The accompanying illustra- tion depicts this novel instru- ment and the manner in which the small drum is inserted. All that is necessary before placing the smaller drum and accessories into the larger is to unlatch a hidden door that is built in the shell of the drum. Suitable music for each pic- ture is printed on the film tion of this amplifier. Showing how the small drum is placed inside the large one Grandstand from Ammunition Boxes ALVAGE of the war is now improving the standards of sport in England. This grandstand for the tennis matches at Wim- bledon is constructed of ammunition boxes. Unlimited amounts of these boxes can be had almost for the asking, and since they are about ten inches square and are exactly the right height for seats, no additional lumber is needed to make the stand. Virtually no carpenter work was needed for this job, as the boxes could be piled by common labor. They were received from the army with the covers already screwed on. As they were made of smooth planed boards and were already pointed, the stands were quickly built and gave perfect satisfaction. A Homemade Silencer for the Motorcycle HE innocent little section of stovepipe that this man has attached to the muffler of his motorcycle is the terror of every dog in the surrounding countryside. People complained that this man’s motorcycle mate too much noise. He is an enthusiast, and they declared he rode about so much they were unable to sleep. They became so bitter about the matter that he put on the pipe, which performs perfectly as a muffler. His machine is now absolutely noiseless. He travels ‘down the road like a ghost. Except for the sound of the tires on the road and the clicking of the engine-valves, there is nothing to cause annoyance. Ammunition boxes brought back from France to England were used to Build this grand stand 9 The piece of stovepipe on the motorcycle is a muffler and not a patent traveling stove a an 2 , ee a

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“SS © PS "St OD he ~ ‘ew we December, 1921 Scissors Create Scenery for Silhouette Movies yore less expensive for motion- picture production will be discovered than the new German silhouette film dramas. Double-exposure of the negative and the clipping out of small scenic frames of black cardboard is what produces the settings. First, the negative is exposed to the mo- tion of the silhouetted human figures, light being thrown on them through a screen, their camera side being wholly dark. The number of feet of each ‘‘shot”’ is carefully booked, and the negative next run through for a second exposure to take the setting, which need be no larger than a few inches. Earth-Borer Plants Dynamite T is tedious work to bore holes in hard soil by hand, yet this must be done be- fore dynamite can be used to shatter hard soils and form holes in which to plant trees and set poles. A portable earth-boring machine, in- vented by an Illinois man, greatly simplifies the work. The device consists of a set of light tubular hinged trusses, the ends of which are fitted with gear-driven boring- gears to operate the augers. The machine will drive four drills more quickly than one drill can be operated by hand. Since the holes are spaced fifteen feet apart in the form of a square, hard-pan can be drilled rapidly for subsoil blasting. The framework is designed to fold up and can be carried on the chassis of the automobile, the engine of which furnishes the power for the drilling. Rain-Making Machine to Produce Natural Storm — - SS The miniature tornado produced by these high-speed blowers is guaranteed to bring rain OUR blowers of one twentieth horse- power each, which force air through a spiral pipe at 1100 cubic feet a minute with a velocity of sixty miles an hour, are the features of a rain-making machine with which it is proposed to produce natural storms by artificial means. After considerable research, it is the inventor’s belief that by forcing warm air from the earth’s. surface up into high altitudes, an ascending chimney, or minia- ture tornado center will be created which will eventually produce an area of low barometric pressure with its accompanying fall of rain. By changing the position of air gates in the base of the machine it is expected that a high-barometric storm may be produced whenever desired. The illustration is a model. The full- sized machine will consist of high towers and motors of five hundred horsepower. While it is probably true that if an area of high or low pressure could be produced artificially, rain would follow, it is very doubtful if any human machine could move the hundreds of millions of tons of air involved in a space of time sufficiently short. Portable Typewriter for the Blind HE German government is marching abreast of the Allied governments, in teaching many of the men blinded in the war to earn their living as typists. The illustration shows a special machine invented for use by the blind. The letters on the scale are in relief, so that the ma- chine may be operated by feeling with the finger-tips. No typewriter ribbon is used. A thin printing-ink from a reservoir on the right is distributed over the type by a roller. Raised letters on keyboard allow the blind to operate this portable typewriter Is your mind as keen as you think it is? Test it with the Sam Loyd Prize Brain-Twisters on page 74 Coal-Pusher Saves Labor of - Locomotive Firemen EW athletes have been known to train by taking a job as a fireman on a loco- motive. Even if union rules did not forbid, they would probably find the work too hard and prefer some comparatively lighter toil like blacksmithing or lumbering. Indeed, the task of firing a modern freight locomo- tive is so arduous that the best “‘knights of the shovel” are being overworked, and the gigantic shovel shown in the sketch is being installed to lighten their labors. It is operated by compressed air, and pushes for- ward the coal in the locomotive tender on to the firing deck as it is needed. New Process Extracts Oil from Apricot Kernels PRICOT kernels, formerly considered as waste, are now being pressed to remove the oil, which has been found useful in making salad-dressing and for frying. Hydraulic presses, with a pressure of five tons to the square inch, extract the oil without the use of heat. Futhermore, it is not necessary to refine the oil before it reaches the customer. About twenty-five thousand kernels are needed to make one gallon of oil.

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a ¥ Ay ti fi a i ip ; 14 +e papers rsa 52 This electrically operated davit can lower twelve boats in nineteen minutes, and is not made inoperative by the listing of the ship Davit Lowers Lifeboats Quickly he! order to save the minutes which are so precious in time of disaster, lifeboat davits of a new type have been installed on the SS. Arundel Castle. Davits have always had a bad habit of jamming or of lowering the lifeboat unevenly.in an emergency. Another fault has been their inability to do the work when the roll of the ship was too great or the list too heavy. This new davit is said to overcome both of these handicaps. As the illustration shows, it consists of two counterbalanced davit arms connected by a rigid crosspiece. When standing in- active, the davit is swung inboard, out of the way; but when the electric motor is started, the davit swings out and so lifts the boat just enough to clear the ship’s railing before it is finally lowered away. As each of the lifeboats holds sixty persons and twelve boats can be lowered from each davit in nineteen minutes, it is easy to figure how quickly the passengers of the large ocean liner could be handled. Popular Science Monthly The Diver Can Now Light His Gas Torch under Water THE method whereby an oxyacetylene cutting flame is made to burn under water, is simple. The tip of the torch is covered with a bell, to which compressed air is admitted at a pressure sufficient to keep out the water, this pressure being regulated according to the depth at which the work is being done. The difficulty with this process is that the diver is forced to light the torch at the surface, and descend with it burning. If the flame is accident- ally extinguished, which happens’ often, the diver is forced to the surface again to rekin- dle it. This entails a great waste of time and effort. However, the difficulty has now been obviated by an in- vention of a Frenchman, Corne, who has applied to this peacetime problem a method developed for war use. Corne starts the torch by a flame generated from the de- composing water itself by the use of a secret alkaline metal, which, from the description, ap- pears to be sodium, for when metallic sodium is placed in AIR RELL | =a NLET > r COVER ae ae ce a | LIGHTING CARTRIDGE a “4 4 \ tia : The tube or cart- ridge with which the diver ignites the tool under water can be seen at the extremity of this oxyacety- lene torch M. M. water, hydrogen is liberated and much heat produced; in fact, the reaction is so rapid that an explosion sometimes occurs. But as no free oxygen is produced, M. Corne, to get his reaction, adds an oxidizing compound. With the alkaline metal this oxidizing agent is enclosed in a brass tube pierced with vent- holes and provided with a hinged core to prevent accidental ignition of the materials. The lighting device is placed near the tip of the torch on a jointed rod. When the diver has been lowered to the ship’s side, to the lighter, he turns on the compressed air in the torch, admits the water, and in a second the oxyacetylene torch is lighted and he can begin to cut the steel plates. Odd Trolley-Car to Give Local Service from Express Trains ares off an express train going on passengers; and a half mile toslow down. at sixty miles an hour sounds more Accelerating electric motors make the like suicide than practical railroading, yet trolley able to get up headway sufficient to this apparently wild scheme has been pro- keep even with the train in a very few posed in order to shorten the time spent seconds. Although the train might be by the commuter in traveling between his going a mile a minute, it would be no more difficult or dangerous to step on to the plat- office and home. When the commuter steps off the train, he steps on to the platform of a trolley running on tracks parallel to those of the railroad at the same speed as the train. As soon as all the passengers are aboard, the trolley puts on the brakes and draws up at the local station, while the express train goes on without slackening speed. The passengers would have to be standing in the aisles waiting for the trolley to pull up alongside, for a few moments lost in disembarking would require too long a stretch of trolley track. Even under the most favor- able conditions, this track would have to be nearly three miles long— about a mile to get up speed, a mile and a half, or ninety seconds, to take These illustrations show how the transfer between express trains — stations would effected form of the trolley than it is to walk from one car of a train to another, since neither platform would have any motion relative to the passenger. Not only would a scheme of this nature provide better service for the commuter, but because the stops made by the express would be reduced, the cost of opera- tion would be lowered. Good Lumber Cut from Dead Trees HEN sound dead trees are sawn into lumber, there is no method known to the United States Forest Products Laboratory by which the wood can be distinguished from that obtained from live trees. If the tree stands on the stump too long after it is killed, the sapwood is liable to be- come badly damaged by wood-boring © insects, and in time the heartwood will be similarly affected. The heart- wood of all trees is entirely dead, and only a thin layer of cells just under the bark is actually living, so most of the lumber cut is sawn from dead wood, whether the tree itself is dead or not. QO — ee

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December, 1921 53

What Do You Want to Know ? : Let Popular Science Monthly Answer Your. Problems in General Science

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Other Readers’ Questions that Will Interest You Too Is pure radium really used in making the luminous figures on watch-faces? If so, how is it that they can be sold so that allows it to rise from and alight on principally of cellulose. Being of animal the water. origin, woolens and silk are more active cheese? ~2. 1 2222777297 chemically than cellulose products, and : ; What are the advantages to a ship of will combine directly with many dyes. No, the material on luminous dials con- having a gyroscopic compass?—P. S. But cotton cloth demands a substance sists of a minute quantity of a radium : known as a mordant before dyes will salt mixed with some phosphorescent Once set to point north and south, the affect it. Aluminum hydroxide is one substance as sulphide of zine or barium. needle of a gyro-compass is not affected of the mordants that make possible cot- Such a combination will glow more in any way by the motion of the boat ton dyeing with special basic dyestuffs. in the dark than would radium, which, — the near-by presence of metallic oossensses in its pure state, is not luminous. The i RD reason that watches with luminous fig- 2222222222 What is the average velocity of a “‘shoot- ures can still be sold cheaply is due to What is the composition of brass; ing star?’”’—W. A. B. the fact that only an infinitesimal quan- of bronze?—J. G. - Shooting stars have a speed estimated to tity of radium salts is needed to impart Brass consists of about 30 per cent of vary from twenty to forty miles a second. unusual luminosity to the inert salts of zine and the remainder of cop : : oe: 2929299999 barium and zine. Bronze consists of copper and tin in si 2999999999 various proportions, according to the Some time ago I read of an Eastern pro- —— ‘ ” . use to be made of it. For coins ortokens fessor who was =e plans to send a — ed | age ‘ Sewes — = ony the proportions are 95 per cent copper rocket = Mars. as become of the Se a a ee a and 5 per cent tin. A slight addition of Project?—C. I. P. Pongee is a soft, unbleached, washable other substances, such as phosphorus, The moon, not Mars, was to be the silk, made in China from the cocoons of zine, or aluminum, produces other alloys rocket’s objective. Professor Goddard, wild silkworms. In its natural state known as_ phosphor-bronze, bearing of Clark University, who was responsi- pongee ranges from light pearl to tan in metal and aluminum bronze. ble for the original idea, is still carrying ; 0 2799999999 out preliminary experiments on smaller the worms, but it is frequently dyed for rockets. As soon as the most efficient commercial purposes. In dyeing cloth at home it is necessary color, depending on the foods eaten by

to buy and use one kind of dye for type has been devised and tested, it is 1 277222222? woolens and silks and another for cot- expected that y' large rocket will be sent ss : ; tons. Why cannot the same dye be off on its long journey of 290,000 miles ‘ At what altitude would a human being = .....4 for both fabrics?—I. S. E. to the moon. I die for want of oxygen?—A. L. O. 3 : a ities Lt. This depends on the individual. Some bs we and = —_ sen — bi oe | See. mn exiles persons would faint at eighteen thou- a ee ne a ee What is the commercial cost of liquid sand feet, while others could achieve — ae purpose is it mostly , twenty-five thousand feet before feeling ff utilized?—E. S. a: any ill effects. At something over Learn here the answers to many in- Liquid air costs about two dollars a 4 twenty-five thousand feet, however, teresting questions asked by read- | gallon. It is used in the manufacture the average person would die for want ers of Popular Science Monthly. | of nitrogenous fertilizer in experiments a) of oxygen. with low temperatures and in the separa- ; 2299922929 And ask questions of your own. tion of gases. - Can you tell me the area of the Pacific Every reasonable specific query in the | 2222222292 y Ocean?—M. G. G. field of general science addressed to If a man held a light and a heavy article a It is impossible to define exactly the this department will receive = | and let them fall from the same height in limits of the Pacific, but if all the seas prompt reply. —— ee a E-weg > would depend on the use to which the

V hull or a modification of either. A New York. motor will be placed. Your question is hydro-airplane is an airplane with a body . vague.

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An Open Fire without Smoke and Dirt HIS looks like a coal-fire. The heat is the same; the same flickering light plays on the hearth and dances from the polished andirons—but there is no smoke and no dirt. A grate filled with colored chunks of Belgian glass, two electric lights, a pair of fans with aluminum blades, a switch, and an electric heater have solved the problem of how to combine the convenience and clean- liness of electric heat with the romance and beauty of the open hv arth fire. The lamps shining through the lumps of glass give them the appearance of blazing coals, and the heat arising from the electric heaters makes the two aluminum fans revolve just fast enough to cast the flicker- ing light characteristic of the open fire over the room.

Wooden Tone-Arm for Use on Phonographs

RADICAL changes in design mark the wooden tone-arm for phonographs that has been invented by B. C. Repp, of Plainfield, New Jersey. The arm is made of solid wood and is attached by a linen thread to a sounding-box fixed immovably in the center of the instrument. The ordinary metal needle is used, but the inventor claims the position of the tone- arm permits the needle to rest on the record at an unusually small angle. As a result, the needle slides more easily over the surface of the record, and scratching and harsh, metallic sounds in repoduction are reduced to a minimum. The tone arm is built of wood similar to that used in the construction of violins, and the complete device is said to add to the beauty of tone of the music, and to prolong the life of the records considerably.

TRACING migratory birds by attaching metal bands to their legs has been prac- tised since 1710. Hunters finding such birds should communicate with the Bureau of Biological Survey, Department of Agri- culture, Washington, D. C. Popular Science Monthly Rapid Interest Indicator for Savings-Banks A NEW system and device for quickly finding, displaying, and indicating interest on savings accounts of various amounts at various rates of interest, has been invented by Harry S. Moir. The function of the invention is to locate quickly the amount of interest on an even sum of money for an even period of time without calculation or eye strain. This makes it possible to find the correct interest expeditiously, notwithstanding items of deposit and withdrawal. For example, if a savings account at the beginning of a year is $10,000, the correct interest in anticipa- tion of said amount being left in the bank at 4 per cent amounts to $200. Suppose the next deposit is $245. The interest is found by moving the gate-holder so that the pointer will point to 245, then sliding the gate so as to open the holder slot on the January columns, which shows the inter- est on that deposit to be $4.90. Thus, in posting, it is necessary only to slide the gates from one of the columns to another, according to the date of deposits, and ad- just the indicator according to the amount.

The complicated interest computa- tions of banker and broker are handled easily by this attachment The interest items are totaled on an adding-machine and the interest on with- drawals subtracted, giving the balance to be credited the depositor.

A Country Estate Built on a Factory Roof N Cleveland, the manager of a manu- facturing concern has arranged a coun- try estate on the roof of his factory, a hun- dred feet above the street, which is unique in that it possesses an astronomical observ-

What appears like a back-yard garden is in reality a miniature estate on a factory roof atory with a powerful telescope, and an extensive greenhouse used in raising vege- tables for the firm’s cafeteria and cut flowers for the offices and clubrooms. Cypress and fir-trees planted on the roof give it the air of a genuine garden. All em- ployees of the firm have free access to the garden. The beauty of the spot, with the view over Lake Erie, less than two hundred feet away, makes it a favorite gathering- place the year round. The garden has been laid out after a plan inspired by examples of the Spanish Renaissance.

Rotary Photo-Print Trimmer

WF or Pi photographic prints may be trimmed with this rotary cutter, which cuts more cleanly than the guillotine type, and which will handle a dozen prints at once. The tracks rods support a cutting disk mounted on a wooden drum. The disk is rotated by a rawhide belt as the handle is pushed back and forth, and auto- matically sharpens itself by contact with the steel bed plate.

Contractor’s Truck Carries Double Hoppers O as to meet the demand for a truck that will handle building material ex- peditiously, and at the same time work in confined spaces and on soft ground, this new vehicle has been designed embodying the features that the experience of the building contractor has shown to be neces- sary. The short wheel-base makes it easy to turn on an eighteen-foot subgrade. Pneu- matic tires permit operation on soft ground and prevent the subgrades from being broken down. Smaller wheels on the front

A divided truck body helps the con- tractor who handles several kinds of materia! reduce the turning radius, and as all the load is carried on the rear wheels, the truck is just as safe as if larger and more expen- sive tires were used on all four wheels. To unload, the driver raises a safety catch with a trip-bar and gravity does the rest. The shock is absorbed by the coil- springs in front of the hopper, and the tilt is controlled by a chain. These features allow merely a part-of the load to be dumped. All working parts are protected from dirt. A three-point suspension motor ‘prevents the transmission from being in- jured by road distortion.

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i= CMmMuUuUrnriit A al ‘ un CTV hey © December, 1921 A Hand-Power Drill for Prospectors te TILTING SEGMENT yee over eight years John M. Calder- wood sought to invent a mining-drill that would give the prospectors of the West the benefits of power drilling by a machine light enough to carry over desert country on the back of a burro and easier and more efficient in operation than the laborious hand-drilling incident to the use of single and double jack-hammers. The illustration shows the successful out- come of his experiments. The Calderwood drill consists of an upright column with a standard screw-jack on the top and bottom for putting the machine in position in either tunnel or shaft. Sliding on the column is a collar holding a carrier mounted on a tilting segment, which can be fastened in any position by set-screws. It will be seen that this construction. permits two complete circular movements of the drill- ing-tool, one vertically and one horizon- tally; adjustments can be made to the fraction of an inch in from one to three minutes. A hole can be drilled by one man in about half the time required by two men with the old double jack-hammers. The me- chanical sledge weighs eighteen pounds, and because of the attached springs is not harder to swing than the three and a half pound single jack. Every Pebble a Hemisphere of Ice and Life ON the beach in winter alternate thawing and freezing may create surprising sculptures in ice. The level snow-floor, perhaps several feet above the pebbles, be- gins to melt and the water collects between the pebbles. This makes the snow above melt faster, and where the beach is undis- Frozen snow clinging to the pebbles gives a weird effect to this rock-strewn beach turbed by waves, the water from the melt- ing snow cuts away the depressions, leaving the packed snow on the pebbles in the form of hemispheres. Curiously enough, these ice worlds are swarming with all kinds of germ life. Snow collects millions of germs in its folds, and these are present in the deposits on the pebbles. After the snows of winter have each left their quota of bacteria in these shallow de- pressions along the shore, the spring sun- shine brings the germs to life. Spores of plants as well as germs are deposited from the air by falling snow and rain, thus making of any beach a swarming hive of life. Primitive Canoe Built of Inflated Skins qc of this type are in general use on the rivers of Peru and the interior of South America. They are built of inflated skins protected by a covering of reed mats lashed into rolls like the new balsa rafts carried by our most modern liners. 55 Cell A Million Dollars Lost if This Lamp Goes Out Geons rely absolutely on the fact that the ships and buoys tended by the U.S. lighthouse service will be in position with their lights burning under all conditions of weather and sea. It is rare indeed that their confidence is misplaced, and yet a buoy of the type illustrated is only sup- plied with fuel once a year. The crew is filling the tanks with compressed acetylene while they inspect the light mechanism which will give a ten second flash every minute’ for the next twelve months, and if their work is not well done it may mean the wreck of a ship worth a million dollars. Acetylene is but one of the many fuels used for illuminating the beacons along the coast of the United States. The principal source of light is the kerosene-oil-wick type of lamp. Then comes the oil vapor lamp using vaporized kerosene oil with a mantle, and in special instances even electric arc lamps and incandescent bulbs have been adapted for use in lighthouses and light- ships. Bulges on Cruiser’s Sides Protect against Torpedoes be the British navy, where they were invented as a protection for cruisers against torpedo attacks, these bulges are known by the picturesque term of “blis- ters.”’ This particular illustration shows H.M.S. Efingham with one of the blister swell- ings under her waterline. The white fin along the side of the “‘blister’”” reduces the skin resistance of the bulge and enables the ship to make better speed. In construction these bulges are formed of a series of crosswise girders, which pro- vide a cushioning effect in the event of a direct hit from a torpedo or the sudden shock of an aircraft bomb exploding along- side. It is evident from -published plans that the powerful Japanese battleships, Kaga and Tosa, described at length in the November Popular Science Monthly, are to be equip- ped with these unique protective blisters. ne = Sete sage et ane heated Serge se : | | sw ennoeti rem oe — ee ET, ee, - oe : wearer mtg n n es ts Seen ae a ge NE Tn Ea EE naeentasii = yas dn eer toma 2 ee ene ee ne eee ete

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Power House Starts when Light Is Turned On BOVE is shown a complete generating 4 4% plant, which may be put in operation by turning on any light on the line it sup-- plies. It is rather difficult to see how a lighting plant which is not running will sup- ply current for a light, but it is simple enough to comprehend when it is learned that turning on the light causes the storage battery to discharge through the small motor, mounted on the side of the unit. This motor starts the gasoline engine, like any automobile self-starter. As soon as the gasoline motor has reached a certain speed, the small motor which served to start it is automatically cut out and the circuit to the light you turned on is also broken temporarily. The generator, entirely encased by the drum, shown in the right of the picture, then begins functioning and delivers the power necessary for lighting your light up to the limit of the power of the unit, which is 1500 watts. As soon as the current begins flowing into the line, it also flows into the starting battery, so that it will always have suffi- cient power to start the unit when you turn the switch. Great changes in the load are followed so rapidly by the governor, that it is almost impossible to notice even a momentary flickering of the lights. Fast Grinding Compound now Used for Bearings UICK action in fitting bearings is se- cured with a new bearing-grinding compound in which a 90 per cent bearing surface can be attained in brass and anti- friction metal after from ten to twenty minutes of grinding. Cast-iron bearings averaging 15 percent surface can be ground up to a 60 percent bearing area in twenty- five minutes. After prolonged testing the shaft used throughout the trials showed no appreciable wear. Although the compound is very fast- cutting, since the time saved runs from 75 to 100 per cent, it is not a grit or carborundum compound. The active prin- ciple seems to be a mixture of pulverized natural feldspar, sodium carbonate, cal- House-Moving in the Philippines HEN a Filipino moves to the next town, he calls a half dozen of his friends to help him. They pick up his house on their shoulders and carry it bodily to its new location. Popular Science Monthly Ventilated Apartments Are the Style for Song-Birds nae songbirds of migratory habits will not go South in the winter if they are provided with a warm, comfortable nest and plenty of food. The Department of Agriculture has repeatedly demonstrated the advantage of using birds to protect the garden, but bird-houses suspended in the hot sun in summer and with no provision against the cold of winter are nothing more than slaughter-houses. The construction of the bird-house built by Edwin H. Rieber, of Webster, New York, is almost ideal. It is a “ventilated apartment.”’ An air space around the nest chamber and under the roof prevents the accumulation of heat in summer and retains enough animal warmth to keep the nest comfortable in winter. The inner chamber is formed of thin, spongy wood so that the moisture it absorbs will help keep the house cool in summer. Scientific cal- culation shows just how deep to make the nest cavity and how large to make the en- trance to attract the species desired. Dirigible Directs Land Traffic by Radiophone © Kadel & Herbert BN an Tre ee a , A continuous bearing in twenty-five minutes of — ding is the accomplish- ment of this rapid acting abrasive pet sey Ie cium oxide, lampblack, and oil. Whatever the formula, it produces a better bearing than is possible by scraping methods, for these leave numerous high spots which make it necessary to take up the bearing as they wear down, whereas a ground bearing has a continuous surface to start with. OnE of the very simplest and safest methods of fireproofing dress materials of linen or cotton consists in sizing them with a starch compound composed of 30 parts UCH a - multitude of motor-cars of sodium tungstate and 20 parts of borax dissolved in water and mixed with 50 or 60 parts of starch. The compound will not injure the fabric. thronged the roads to Croydon, En- gland, on the occasion of the aerial Derby that traffic was directed from a dirigible 2000 feet in the air. ‘The traffic officers far above the road were able to see the prob- lem as a whole, and by relaying their orders via wireless telephone to the truck station on the ground, here illustrated, everything was kept running smoothly.

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December, 1921 Baby’s Bath with All the Latest Improvements A COMBINED bath and dressing-table for the baby, which gives mother the opportunity to bathe him in the bathroom without carrying water or stooping, is recommended by physicians and nurses ex- pert in the care of babies. It is made to fit over the regular tub, and when not in use folds out of the way against the wall. This improvement is one of many inven- tions that are beginning to take the back- ache out of women’s work. The bath and the table are waist high, so that there is no need to bend over while washing or dressing the child. The bath itself can be filled by a hose from the usual faucet. The apparatus takes the drudgery out of baby’s daily bath and makes cleanliness a happy achievement. Animal Life in the Sky X4MINATION of many specimens of meteorites has revealed the presence in them of living organisms. On being placed in the laboratory under suitable breeding conditions, the samples came to life and multiplied. Further study of these micro-organisms will goa long way in verifying the claims of certain scientists as to the animal life existing in other worlds. Wind Creates Natural Draft for Sawdust Incinerator re this improved sawdust incinerator, wind blowing from any direction is used to create a forced draft by its passage between the baffled openings and outlet holes in the conical section of the stack. The air also cools the exterior shell so that hardly any warmth can be felt on the out- side, even when the sawdust is burning full blast. There is an inner stack of firebrick, with upper and lower inlets on four sides that register with those in the outer concrete FIREBRICK LINING ee” Openings pointing every way insure sufficient draft whatever the direc- tion of wind shell. All these inlets have baffled open- ings so that the air admitted to the stack is under control by the fireman. Sawdust is supplied to the incinerator automatically through the blower shown at the left. re Se Movies Now Carry Their Own Power Plant 29" RRA A powerful water-cooled gas-engine on this truck drives a generator that > produces power for the searchlights used in making motion-pictures ‘THE majority of motion-picture films are produced “on location.” This may mean a beautiful spot just out- side the studio door or it may signify a thousand-mile trip to a mountain top or a desert waste. Some of the location views must be taken at night, necessitating some source of current for the numerous flood- and spot-lamps used. Self-contained power plants on trucks are used for this purpose. The illustration shows a portable power plant from the Ince studio. All control switches with indicating meters are placed directly back of the driver’s seat. Behind the switchboard is the powerful gasoline engine that drives the generator. The radiator used to cool the circulating water is on the rear with a fan back of it to create a cooling breeze over the engine cylinders. 57 Street Stations for First Aid MALL first-aid stations completely equipped with medicines and materials likely to be needed after a street accident, have made their appearance in some of the cities of Europe. The cabinet is operated like an American fire alarm. When an accident occurs, the policeman breaks the glass over the little door in the center of the panel and the cabinet opens automatically. Inside are a stretcher for serious cases, drinking water, tourniquets, antiseptics, and bandages needed for taking care of an injured person while awaiting the arrival of the ambulance. Separates Liquids from Soil B* the use of a centrifugal separator of unusual power, M.S. Anderson, of the Bureau of Soils, has already demonstrated that the salts appearing in soils are more complex than has been hitherto believed. The separator was designed to expedite the analysis of the soil of farms and the The Bureau of Soils is using a cream- separator to separate liquids from soil during tests earth that is to be used for building roads. With a maximum speed of 17,500 revolu- tions a minute, the machine separates the liquids from the solid particles of the soil with unprecedented rapidity, permitting analysis in wholesale quantities.

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se a ones rte +: i. ee at eae Beata one Ba aS Centrifugal Force—the Energy that Snaps the Whip and Dries the Clothes How terrific destructive power is usefully applied in industry as O Slow— Dangerous Curve Ahead’”’ * warns the sign by the roadside, but if it were made to say what it really means, it would read, “‘Look out for centrifugal force,” for that is the mechan- ical principle which causes most of the accidents along the highways. Centrifugal means ‘‘the tendency to fly away from the center.”” You will remem- ber that Newton’s second law of motion is to the effect that matter always seeks to move in straight lines. When anything moves in a curved or a circular path, it does so under protest. It is always trying to break away and follow its inclination to travel in a straight line. The simplest illustration of this is the boy’s toy sling. You remember how you used to whirl a stone around your head on the end of a string and how far it would travel when the string was released. The cord compelled the stone to move in a circle, but it was always trying to fly at a tangent to the circum- attached to a revolving spindle are directly geared to the flywheel. When the engine is at rest, the force of gravity makes the arms hang down, but as soon as it begins to turn, centrifugal force impels the arms to fly away from the axis of the spindle. They rise up against the force of gravity, and the faster the spindle turns the nearer the arms will approach the horizontal. The arms are connected with a lever controlling the throttle-valve, which is slowly shut as the flying arms of the governor lift. The faster the engine turns, the less steam is admitted to the cylinders, and if the speed approaches the danger point, the governor will shut the steam off altogether. When the engine slows down, the arms fall, and more steam is admitted. In this way the speed can be kept constant. Governors are so designed that the steam will be shut off if they break, since without some device to prevent the speed from increasing, a steam-engine would revolve Popular Science Monthly Centrifugal force really killed Goliath. When David swung the primi- tive sling around his head, it was centrifugal force that gave mo- mentum to the stone so rapidly that the centrifugal force de- veloped by the flywheel would break the engine to pieces. In this way the engineer prevents such an accident by a clever use of the very force that causes the possibility. Another general type of centrifugal ma- chine takes advantage of the fact that at constant speeds the amount of centrifugal force depends on the weight of the sub- stances revolving. You remember that you can swing a pail of milk round and round over your head without spilling a drop, because centrifugal force holds the milk against the bottom of the pail. Now, if you could swing that pail fast enough, the skim milk would collect in the bot- But centrifugal force, like fire, is as helpful as it is dangerous. Once it is allowed to become un- manageable, it will wreak dis- aster, but if properly applied, it is found to be one of the most useful forces in nature. With the aid of friction it moves the automobile along the road. As used in the steam-engine, it even keeps a check on itself, for the engine governor operated by centrifugal force is the only thing that keeps the engine flywheel from speeding up and whirling itself to pieces by centrifugal force. It Made White Sugar Possible Before the application of cen- trifugal force pure white sugar was unknown. Batteries of centrif- ugal separators now form a vi- tally important part of the me- chanical equipment of every dairy and chemical plant. Without its use it would take days instead of hours to finish our laundry. The phonograph and the passenger elevator would be impossible, and it would be as dangerous to run a steam-engine as to manufacture dynamite. By recalling again the toy sling, it is easy to see that the amount of centrifugal force will vary directly with the weight of the wheel or other body being revolved and with the speed at which the body is being rotated. These unchanging proper- ties of centrifugal force are what makes it so valuable. Suppose, for instance, you want an engine to turn over at a constant rate of speed, not necessarily a huge engine, but a small one like the spring engine that drives your phonograph. Or suppose you merely want to make sure that the engine will not speed up above a certain point, such as the motors operating elevator hoists. How can a governor be designed to do this? A governor that will be simple and absolutely positive in its action? Only by taking advantage of centrifugal force. In an engine governor, two hinged arms ference and did so when released. Ja There is an inter- esting paradox in steam-engine de- sign. Centrifugal force is used in the governor to prevent the engine from running away and destroy- ing itself through centrifugal force exerted on the revolving flywheel. The illustration above pictures the chaos in an en- gine-room when the governor fails to act and allows the engine to tear itself apart tom because it is heavier than the cream. Hundreds of ma- chines employ this principle of centrifugal separation. For Separating Liquids Milk, or oil, or paint, it makes no difference what the substances may be; whenever two liquids differ slightly in weight we can separate them by revolving the mixture rapidly in a bowl and drawing off the heavier mixture from a spout near the circum- ference and the lighter one from an opening closer to the center. By changing the position of the spouts, we can get just the per- centage of mixture we please. By slight variations in speed and ad- justment, for example, a cream- ~ Hlustrated above is an actual scene of what happened toa plant when an engine got out of contro

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Deeember, 1991 In every modern laundry centrifugal force dries the clothes. This metal basket is whirled at a high velocity, throwing the globules of water to the outside through perforated holes separator will turn out a cream so thick that it can scarcely be poured, or the thin- nest of skim milk. In the same way water and dirt can be cleaned from oil more efficiently than it can be removed by the most elaborate straining. Many modern dryers are also centrif- ugal machines. In sugar-drying machines the bowl has an inner lining perforated like a sieve. The moisture is forced through the material and driven out through the holes, while the solid substances are held against the side of the walls. As the ma- chine starts to slow down, the moisture trickles off, and a few moments later the dry sugar is allowed to fall through the bottom of the bowl into a conveyor wait- ing to receive it. ° Before the introduction cf centrifugal machines, in 1850, sugar was light brown instead of white in color, as it was impos- sible to strain off all the molasses. The separation is essentially an accelerated screening process, which is the same in principle as filtering by gravity, but centrifugal force in the usual machine is from four hundred to six hundred times as powerful and the drying process is almost unbelievably thorough and rapid. In one sugar refinery four centrifugals operated by two men purged, washed, and dried thirty-five thousand pounds of sugar in one hour and three quarters. One dryer will handle three hundred pounds at a load and since it requires only thirty-five seconds to stop or'start the best machines, from twelve to fifteen charges can be treated in an hour. Virtually all drying of chemicals is done by centrifugals, since the machines can handle any granular and fibrous matter that will permit the liquid to seep through. For this reason city laundries use centrif- ugals for drying clothes. It is a scientific application of the method used by a dog when he shakes the water out of his coat, and you can imagine that after being “shaken” at over three hundred revolu- tions a minute the clothes are as dry as if they had been hanging in the sun for hours. The clothes are held firmly against the sides of the basket, and there is no tendency to break or weaken the fabric. Freeing Compressed Air from Moisture In some industries centrifugal separation is accomplished without the use of whirling machinery. In freeing compressed air from moisture, for example, it has been found that sending the air through a specially designed pipe elbow, which forces it to whirl in a helical path around a central core, will strain out the water perfectly. The moisture is so much heavier than the air that it will not take the turn as readily. Centrifugal force throws it out of the path of the air against the wall of the pipe, from 59 Cream-separators would be impossible without centrifugal force. It is this force that draws the cream from the milk and carries it to the top of the bowl, where it drops by gravity into the cream-can which it trickles down slowly into a re- ceiver. An elaboration of this principle is used in Norway to separate the nitrogen and oxygen of the air. These gases are almost the same weight, but although the relation between their densities is as 14 : 16, when they are forced to turn an elbow at high speed, the heavier oxygen will be thrown against the outer wall. This demonstrates the great delicacy of centrifugal methods of separation. There is again the danger from centrifugal force that lies in wait at the curves along the highways, for a speeding automobile tends to keep moving in a straight line, and if it be turned too sharply, centrifugal force will lift the inner wheels from the road, or even turn the car into the ditch. The “Go Slow”’ sign at the turn is really a warn- ing against centrifugal force. How To Be Measured for a Set of False Teeth A GAGE for measuring artificial teeth has been devised by Dr. William C. Darbey, of Shanghai, China. It consists of a horizontal bar that is rested on the head of the patient, and two depending bars, each of which carry measurement markings on their lower portions. These bars are pivoted to the horizontal bar, and one of them may be slipped along this member to adapt the instrument to persons having faces of different degrees of fullness. When these bars are brought into alinement with the jawbones of the person desiring artificial teeth, a pointer indicates the proper size on a scale. The scale is marked with the proper size and form of teeth required for every conformation of skull and jaw, so the -dentist is relieved from all uncertainties in the prescription. Tropical Lineman Has Hard Job gc cipal parts of South America are the habitat of a large spider that weaves its web around the telephone wires strung on the cross arms of poles. The spider is enormous and its web is heavy and of a thick texture. The telephone companies were much perplexed when in the late evenings and nights frequent short circuits tied up their lines. After a time they discovered that the trouble arose from the heavy spider webs. When the sun was out, the webs were dry and there was no trouble; but at night, when the webs were covered with dew, short circuits occurred. The only remedy is constant brushing away of the webs from the telephone wires. Submarine Mine-Sweeper Enters the Movies Ree to cut wire entanglements and sweep mines during the war, which is the explanation of the saw-teeth on the Used by the ~g ey = —— the war, this mine-sweeper has become a film company e property of runners, this German submarine sled is now the property of a moving-picture concern. It is as large as an airplane, and moves along the bottom of the sea under its own power. The driver is encased in a diver’s suit, and the invention affords an unequalled opportunity for taking pictures of the aquatic life beneath the surface of the sea. — a IE Ca ne Ser pared aaa at ea = einai ates Las —.. E noe

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Stetina ain Si inten St OS Eft a Identifying Criminals by Their Pores A pore-print taken at the scene of crime A pore-print taken from the suspect Popular Science Monthly This Machine Measures Wire of Any Size [NX measuring wires and cables correctly it is essential that they pass through the machine in a straight line, and that the measuring wheel be of ample size and offer no resistance when it is set in motion. These features have been embodied in the invention depicted, which will measure any wire up to cables two inches in diameter. Guide rollers front and rear of the press wheel keep the wire from sagging, and the measuring wheel is four feet in circum- ference. Both the wheels run on roller bearings, and may be spun with one finger while a fe) ae Pore-prints are as infallible as finger-prints. The arrows point to a char- acteristic in each print that positively identifies the suspect. The ridges at the arrow-heads are similar in alinement and each contains the same number of pores OWADAYS, the ease with which these correspond exactly, the man is guilty, criminals may be identified by finger- prints is well known. But sometimes the finger-prints are blurred, half wiped out by the thief, or only a very small part of the finger-tip is shown. In these cases, which are becoming more frequent as the under- world recognizes the danger of leaving finger-prints on the scene of crime, this method of identification is impractical. In order to identify the criminal from the smallest and most fragmentary imprint, a French scientist has perfected a positive method of identification through the indi- viduality of the innumerable sweat-glands on the fingers. In an enlarged photograph of a finger- print the orifices of the sweat-glands ap- pear as small black dots upon the convo- luted ridges that make up the imprint. Scientists have discovered that the number of these glands, their arrangement, and position, is different for every individual, and like the pattern of the finger-print it- self, never changes during life. It is clear then, that here is a scheme of identification that may be employed when the usual finger-printing methods fail. Even the shape of the mouths of these glands varies. Usually it is a perfect circle, but often the prints will show an oval, a triangle, or an ellipse. The usual method cf taking finger- prints, which employs printer’s ink, is not suitable for showing these pores, as the ink is somewhat greasy and fills them completely. Graphite and lampblack have the same effect. Pore-prints should be taken with a light powder such as copper oxide or white lead. A little of this powder is blown on the finger-prints discovered at the scene of the crime, and then they are photographed by a camera, which enlarges the print several hundred diameters, so that the sweat-pores appear from six to eight millimeters in diameter in the print. The same method is taken to get a finger-print from the man suspected of the crime, and from this point on the identification is simple. It‘is only necessary to compare the number, the posi- tion, and the form of the visible pores. If without a doubt. The method is not confined to the pores of the fingers, since the arrangement of the glands on any other portion of the body is equally characteristic. In a recent police case in Lyons, a thief took the precaution of wearing gloves, and left no finger-prints at all. The police discovered, however, that he had rested his forearm on the marble top of a table. A print was taken, and a positive identification effected by an examination of the pores. The criminal of today has indeed to “‘watch his step” to elude the fast-closing circle of identification tests that the modern criminologist has at his command. Cables up to two inches in diameter can be measured with this machine. A dial automatically indicates the cable’s length pressure of one hundred and ten pounds is exerted on the wire. The pressure is adjusted by means of a sliding weight and rod placed on either side of the swinging cradle. The resetting of the dial is accomplished by means of .a disengaging mechanism, and the height of the wire from the floor may be varied from thirty-four inches to four feet. Fossil Shark Could Swallow Small Whale Courtesy American Museum of Natural History The jawbones and teeth of an extinct shark which swam along the coast of Florida several mil- lion years ago. Be- low, at the right, a specimen of the small sharks that now frequent our - coasts THs jawbone of a fossil shark set up at the Museum of Natural History in New York City, gives an idea of the monstrous size of some of the fish that inhabited the seas in past ages.. From the size of the bones that have been dredged from the ocean bottom it is believed that sharks ninety feet or more in length have existed. The most formidable of all present-day sharks, those found in the tropical seas, seldom | attain a length of more than forty feet. Science has found a way to use the skin of the shark for making durable leather and the bones and flesh are good for fertilizer, also the fins of some species of shark make a very tough gelatine. Shark- fishing, like whaling and seal- ing, has now become an indus- try in itself.

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December, 1921 61 England Designs Battleplane to Carry 12-Inch Gun Weapon with no recoil is to be built into fuselage By P. J e Risdon, English correspondent of Popular Science Monthly © Modern Publishing Company Drawings by G. A. Davis Huge battleship of the air equipped with one twelve-inch gun extending from front to rear and built into the plane as part of the fuselage, are being developed in England guns as large as those of a modern battle cruiser comprise a late aerial development that follows close on the heels of the recent battleship-bombing tests in England and America. The gun used is the “‘no recoil’? Davis gun on which experi- ments were being conducted during the later days of the war. It is the unusual principle of the gun and not the con- struction of the plane that makes the com- [esse as larze as of the air carrying mounted in front of the gun layer in the cockpit‘and firing tracer bullets. - Although under normal conditions the pilot has complete command over the plane, it will be necessary to transfer this command to the gun layer during action. The duties of each member of the crew will be correlated by a complete system of telephonic communication. Just how many twelve-inch shells can be carried on a plane has not yet been settled. It may be that the weight of the gun will be such that the supply of heavy shells will be limited, in the same way that bombing- planes are restricted in the number of bombs that can be carried. But further development along these lines may lead to an aerial fighting unit that will demand a complete reversal of tactics when “‘the next war” is upon us. Such a development as the above is but one more stride in the airplane’s progress. ’ bination possible. When an ordinary gun is fired, the enor- mous explosion that expels the projectile reacts on the gun itself with a resultant force © Modern Publishing Company known as the “recoil’’ or ‘‘kick.’”” The heavier —— the shell and the more rigid the mounting, the greater the recoil. a Pag : ‘ ? : ee G Pilot Knowing this, it is obviously impossible to Sipbhing eee : “ i fire a rigidly mounted twelve-inch gun from an airplane in flight without totally destroy- ing the plane. But by constructing the gun with the breach in the center and open at both ends, and filling the rear end of the barrel with finely divided material such as birdshot, the gun may be fired with no apparent recoil. The recoil is present, but it is ex- pended in driving the fine shot from the rear end. This is the idea of the Davis gun. The range of the projectile is considerably re- duced with a rifle of this design, but that matters less with a plane than with battle- ships and land forts. Elimination of the recoil allowed the invent- ors to cut down the thickness of the gun walls and especially the rugged construction of the breech mechanism. The weight of the twelve-inch gun thus reduced makes possible ) its use on airplanes. As at present designed, the airplane to carry the Davis gun will be of the monoplane type with cantilever wings stayed only from below to avoid all outside wiring. The gun itself will an be mounted inside the fuselage and will extend : from end to end of the streamline body. Any backwash of flame and gases after the gun has been fired will be overcome by fitting a metal nose to the machine and protect- gun H W ie : iW 1a { 4 we ee Oe aa al eel a 7 ing the gun layer in the cockpit by a flash- i shield similar to those used on British ) destroyers. | The aim of the gun will be aetermined by the direction of the airplane, | Strange to say, the big twelve-inch gun P . but th will be ‘@anedche wound. f-0 machine sun ut the ome Se be checked up by a machine gun Sries tracer bullets. e insert shows the gunner placing a ont‘ iawn posormagoaatiatat = aa

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62 Portable drill and grinder stops auto- matically when not in use, due to switch in handle, which opens when operator’s grip is relaxed Tools and Machines that Are Money-Savers in the Shop Popular Science Monthly Folded, this device is an ordinary S wrench, but its jaws will fit nuts of any shape and size without wasting time in setting up an adjusting screw Vertical boring and turning mills having a twenty-two-foot swing are used in foun- dries and shipyards to handle large work economically. The table may be elevated to machine castings up to nine feet three inches in height By gradually tapering the thickness of the outside cut- ting edge, the clearance of this cutting-off tool is main- tained throughout the entire circumference Blades clamped to the jaws of any slip-point pliers con- vert them into self-opening metal-cutting shears. No screws are necessary Keeping drills and gages in order is easy with this holder. Tools are re- placed by sliding them into the V gage. They stop opposite the proper hole Fitting either flat or round termi- nals, this new plug will connect the electrically heated glue-pot with any current outlet in the shop Machine and hand expansion ream- ers can be ground accurately to size by this attachment, which fits the angle of any standard table UNIVERSAL-JOINT SPINDLES DRILI-GUIDES Garage men who have many cotter-pins to loosen will appreciate this puller, which This portable lathe can be readily hauled to works like a pair of any work when there is much fitting to be pliers done on machines too bulky to move to the permanent lathe Twelve hundred holes an hour are drilled by this multiple spindle machine. Each head carries, sixteen drills. Variable spindle rota- tion gives the correct cutting speed for each

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rN eee ColllCUwWD December, 1921 63 Remote Control of Clay-Pigeon Traps li automatic clay-bird trap that is entirely different from anything made in this country is revealed in photographs of the first trap-shoot held at the Halen See shooting grounds, near Berlin. In American parlance, an automatic trap means one that is set and pulled from the firing-line, the person in the pit merely loading it for each bird thrown, and also changing the direc- By Capt. Edward C. Crossman to partly overcome the resistance of the lower arm spring, and a much lessened resistance to setting would be encountered. The reverse would be true when the lower arm was sprung. The wires running to the firing-point are tion of the trap from bird to bird. A study of the battery of traps used at this big shoot develops the fact that the traps are made double with throwing arms both above and below. When one arm is for- ward or unset, the other arm is set ready to be released. In the tournament at Halen See, the traps were operated from the firing-point by a set of ten wires terminating at a control board similar in many respects to the signal-control system on a railroad. It would seem that the spring tension on the arm throwing the “bird,” helps to overcome the resistance of the spring of the unset arm and a slight additional pull would then drag the unset arm around to its set position, with the spring extended and ready to throw. The two throwing arms, upper and lower, each with its spring, are thus apparently in a state of approximate balance of spring tension. Both operating on the same ver- tical pivot, when the upper arm, for in- stance, is released and is thrown violently around by the tension of its extended spring, the tension of the spring is sufficient The shooter does not know which of the five traps will be released from this control board both trigger and setting wires, the trapper having only to load the trap as is done with the American automatic device. The game as played by the American sportsman calls for only one trap at a known point, but with the pigeon rising at unknown angles. The foreign trap- shooter, with his more practical idea of how to shoot clay birds, wants his targets to rise from unknown spots as well as to fly at unknown angles. He also keeps his gun below his elbow until the moment the bird appears. At the Halen See shoot the German sportsmen used a battery of five or more traps, set a yard or more apart, thus covering a space of at least twenty feet, from any point of which the bird may appear. The trap to be sprung is optional with the puller, but the shooter does not know which of the five it is to be. The man controlling the traps is placed close enough to the shooter to hear and act instantly upon the command of “re.” In the United States the traps commonly used fall into two classes, one of which is similar to those shown in the illustration, with the excep- tion that the double-deck feature is absent. Up to the present time, the idea of con- trolling the traps from remote points has not been adopted here. Loading the qutemetic traps at the firing-pit before the match begins Paper Pulp, Dyes, and Alcohol from Waste Corncobs OWA chemists believe they have found valuable products locked up in the lowly corncob. Bran, once a waste product of the milling industry, choking the streams that ran by the mills, is now one of America’s most valuable breakfast foods. Corncobs may equal it and prove to be one of the Middle West’s worth-while products. Millions of dollars’ worth of cobs that have decayed in feed lots during the last few centuries may some day be trans- formed into paper pulp suitable for a straw- board substitute. Some of the products that may be secured from cobs are acid tar, wood alcohol, pitch, charcoal, acetic acid, formic acid, and, lastly, furfural. The Bureau of Chemistry of the scientific purposes. The price is about ten dollars a pound, but specialists of the United States Federal Bureau advise that it can be manufactured from corncobs at a cost of from fifteen to twenty cents a pound. Furfural’s most important present-known use is, in chemical nomenclature, as an in- termediate for dyes. A whole series of dyes may be prepared by interaction with vari- ous coal-tar products. Shades covering a wide range already have been made and tested. The United States produces from two and a half to three billion bushels of corn annually. That means about twenty mil- lion tons of cobs. It is evident, therefore, that if all this waste product can be utilized, it will produce an enormous quantity of fur- fural, to say nothing of various other products. Another Scale Pest Makes Its Appearance HIS time it is New Orleans and the sur- rounding territory that is the camping- ground for a new pest. It is called the “camphor scale,” but it has no compunc- tions against other trees such as the citrus, oak, and fig trees. Just how or when the pest got into the United States is not Department of Ag- riculture has already succeeded in recov- ering furfural from corneobs, and ex- periments havedem- onstrated that it can be obtained in large quantities by certain chemical treatments. Fur- fural has been a comparatively rare chemical, and has been sold chiefly in small quantities for Piles of corncobs on an Iowa farm, once wasted, but now awaiting conversion into furfural and other valuable chemical by-products known, but observa- tions of its speed in spreading has led entomologists to be- lieve that it arrived during the past year. Camphor scale is well known in India, China, Japan, Porto Rico, and the Philippines. All the Govern- ment agricultural forces are active in an attempt to erad- icate the pest before it spreads.

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A fi i it 4 dl 64 Motion-Pictures Can Be Shown without Darkening Theater A DAYLIGHT projectorscope has just been demonstrated before the French Academy of Sciences by the French inventor, M. Dussaud. The apparatus projects moving-picture films, stere- opticon views, or even illustrations from a book into a well-lighted room. An im- proved condensing-lens and the use of H ‘ © A. N. Mirzaoft Pictures on the wall, ceiling, or floor in daylight are possible with this pro- jectorscope concentrating mirrors which enlarge the image without the loss of | ght, permit pro- jection without the necessity of darkening the auditorium. THE Chief of Air Service is informed that M. Berger, a Swiss, has invented a muffler for airplane engines which does not heat up nor reduce the power of the motor, while it ‘will allow conversation in an ordi- nary tone of voice between pilot and passen- ger. The invention is similar to an auto- mobile muffler with the addition of a small revolving fan at the rear which aids in cooling the exhaust gases. | Popular Science Monthly LMOST daily there crops up some new evidence of the versatility of motor- trucks. During the round-up season the Pitch- fork Ranch of Wyoming uses a truck to take the place of the old-time mess-wagon, and, like that sturdy vehicle, it often ess-Wagon travels for miles straight across country where there is not a suspicion of a road, following the cow-punchers. The truck carries a complete camping outfit, and delivers ‘‘all the comforts of home” wherever the boys of the outfit happen to be. Safety-Pin for Milk-Cans ERE is Guy S. Brewster, of Seattle, Washington, demonstrating the “‘safety-pin” he has recently invented. Thousands of cans of milk are spilled daily, so Bradley devised a simple but positive lid-clamp of three pieces of spring steel, riveted together. The clamp slips over the top of the can, with the longer strip passing across the top. The shorter side strips grip te neck of the can. Railway-Cars that Unload Automatically Bus illustration shows a new type of ore car used by a German mine. The swinging bottom of the car is released by a lever, which unlocks easily as the load pressure of the car acts horizontally, and the several gates of the swinging bottom have hook locks that open vertically. The lever also returns the gates to the closed position and locks them. P Another type of the car is made in which the gates close themselves after dumping, and in still another type for crate or bag- gage carrying, the gates have extensions to permit the boxes to slide to the track level. New Flashlight Has Three- Hundred-Foot Range CIENTIFIC design of the reflecting mirrors and the invention of a new form of electric-light filament have enabled a flashlight to be put : onthe market which ery ee will throw a clear & " beam of light for SPECIAL three hundred feet— — about six times as SHOC K- far as a good flash- ABSORBERS light generally BATTERY carries. The re- flecting mirror is made in the shape : of a perfect parab- gution ola, so that all the rays leave the lamp SL'DE parallel,and the bulb throws no shadow, ee so that every bit of the illumination is utilized. By turning a screw at the base of the flashlight, the bulb can be moved back END CaP and forth inside the @= mirror. This movee > EXTRA ment, which takes ‘tug igi the filament of the An adjustable reflec- light away from the focal point of the parabolic mirror, makes it possible to throw a broad. shaft of light for a short distance, lighting up a large area, or to produce a narrow beam which will render smali objects clearly visible at three hundred feet. The lamp is already being adopted by many of the police departments throughout the country. The case is made watertight, and the light has been used in a pouring rain without short-circuiting. tor makes possible a 300-foot range As a special service to readers, the Editor will be glad to supply the names and addresses of manufacturers of devices mentioned in Popular Science Monthly. |

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we ewww December, 1921 Ki\>\ 2 "le Can You Get These Eye-Testers Right in Less than a Minute? te Sf XH Find each one of these designs in the set below, and write down its location, as specified in caption No. 4. This test and the one at the left are reproduced 2. Which of the two through the courtesy of Prof. Edward L. Thorndike inner squares in the above drawing is 1. Copy this diagram quickly in freehand; then make a figure 1 H in the space that is in the circle, but not square. Also make a figure 2 in the space that is in the triangle and circle, 4. but not in the the square well OW quick are youreyes? How alert are your Find out by trying these famous intelligence in the triangle or tests. Thev will make instructive recreation for a winter evening’s gathering. Pass around slips of paper with spaces numbered 1, 2, 3, and numbered captions. Keep a stop watch on each contestant. Correctness of answer, as larger, the white or the black? brain cells? Do illusions fool you ? Explanation: _Al- though of the same size, the whitesquare appears larger than the black one, due to irradiation, that Let each person jot down in these spaces i See e 2 2 f 1 rf. i al answers to the questions contained in the ake ae po enray tn seem to extend be- yond their limits on to any darker sur- face that may sur- round them as speed, counts in picking the winner. from margin to margin in the above how many curve upward? | 3. Of the transverse lines that are shown running v &S : 5B 15 | \ \ 20 25 yéM 4. Glance at each of the five figures lettered a, b, c, d, and e at the top of the page. Then find its counterpart in these columns. When found, drawing, indicate its location by setting down the letter it bears at the top of the page and the number it bears in these columns, in this style—f-26 The Engineer Gets His Orders ‘THs ingenious mechanical contrivance is used to deliver orders between the locomotive engineers and the switchmen as the trains of the Midland & Great Northern Railway in England enter a section of single track running between Spalding and Lynn. Orders are issued at every siding telling the engineer to pro- ‘ceed or to draw out and allow another train already on the section to pass. Formerly this was done by hand, which forced the trains to slow down and occa- sionally resulted in messages being missed. The mechanical despatcher is con- structed along the lines of the automatic device by which American trains pick up bags of mail at way stations without reduc- ing speed. The messages are placed in the small bag, and an iron arm projecting from the engine cab trips the catch and picks up the bag by hooking into the iron ring. The picture shows a switchman recovering a message dropped by a passing locomotive. Seed Potatoes Cut by Machine Making Heat Instantly with Chemicals METAL hot-water bag that contains no hot water but that is heated by admitting air to a chemical compound contained inside the case is now on the market. Its action is extremely simple. When the stopper is unscrewed for a fraction of a second, the bottle becomes warm, ‘and will remain so for from eight to twelve hours. Many chemical compounds liberate much heat. Every one has seen the water boil when plasterers mix it with quicklime, but no water at all is used in this device. The chemicals are harmless, may be handled safely, and the bottle will not explode. The instant heat produced without the trouble involved in lighting a fire will be appreciated on camping-trips and in house- hole emergemcies. I is no small job cutting up seed potatoes for planting on a big truck-farm, but a great deal of labor is eliminated by a ma- chine recently devised by John O. Jacob- son, of Nielsville, Minnesota. A plunger pushes one potato at a time against a cross-shaped stationary cutter. A movable cutter cuts the same potato across the cuts of the stationary slicer. When an extra large potato rolls into the slicer, it acts on a knife-spreader that causes the blades to make two cuts instead of one. The device is operated by a motor.

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Measuring and Recording Rain- and Snow-Fall Hew many inches of snow fell by ten o’clock last night, is a question that need no longer be answered by a guess. A recording rain-gage, designed by S. P. Ferguson, meteorologist of the United States Weather Bureau, weighs the total fall of rain, snow, hail, and other solid forms of precipitation at any instant dur- ing the progress of the storm, no matter what its nature. The operating mechanism is essentially aspring balance. Rain or snow falling into the self-contained compartment at the top of the device depresses the spring, and the pen attached to the recording lever makes an upward trace on a cylinder around which is wound a sheet of paper ruled horizontally to inches and tenths of inches and vertically in hours and fractions thereof. This scale of measurement permits the precipitation during any hour of the day to be determined without any necessity for an observer to read the scale. The cylinder just referred to is rotated once in twenty- four hours by a clock with which it is con- nected by means of a carefully adjusted shaft and gearing. Blasting-Fuses Cut to Safe Measure by Machine —* mine accidents are caused by carelessly cut fuses. It is the common practice to cut them by hand one length at a time, and as a result a fuse, intended to allow the miners a certain length of time to seek cover, would explode earlier. These premature explosions never failed to take their toll in lives. A practical miner, has now designed and built the fuse-cutting machine shown in the illustration, which consists of a removable spool secured to one length of a bench about five feet in length and one foot in width. The spool has a capacity of five hundred feet of fuse. At the other end of the bench is mounted a knife, one end stationary, the other operated up and down by a foot lever, which is counterweighted to return it to cutting position. Measur-

The knife operated by a foot-treadle cuts the fuse wires to equal length ing marks are placed two and three feet from the knife. The machine is used at all the mines of the New Jersey Zinc Company. In one mine using six thousand feet of fuse a day, this machine saves the work of four men.

Huge Battery of Flood Lights Illuminates Skyscraper HE illustration shows the Wrigley Building in Chicago, as it is displayed by the light of 214 projectors, producing nearly five million candlepower. The lights themselves are located on the roofs of neighboring buildings and are invisible from the street. The cost of installation of this flood lighting was about $30,000, and the total expenditure for maintenance is about eighty dollars a night.

The Saidy Date Must Go to Quarantine ARLY in 1920, Professor S. C. Mason, of the Bureau of Plant Industry, went to Egypt to get offshoots of the Saidy date, for the purpose of experimenting with its growth in the United States. The Professor brought back about eight- een hundred offshoots—from the Libyan Desert, the neighborhood of Cairo, and the Nile valley. Although many of the date shoots have struck root and are ready to be set out in orchards, the Bureau will not distribute them to growers because the trees have developed infection with two dangerous seale insects—the Parlatoria and the Phoenicoccus. In consequence, the trees must be kept in quarantine for many years to insure the utter destruction of the pests. Popular Science Moniuuwy

Sword-Swallowing Made Possible — all sleight-of-hand tricks there is usually a scientific manipulation that makes the trick possible. The sword- swallower of China, represented in the illustration as about to devour the sword, is no exception. The sword he is swallow- ing is keen and highly tempered, but a mechanical device in the handle allows the blade to slide back as the hilt passesintothe conjurer’s mouth. The point is hela against the teeth as the lips draw the handle inward. The snake-charmers of India likewise have their tricks of science, unnoticed to the spellbound audience, but absolutelv necessary as part of their stunt.

Combined Handle-Bar and Package-Carrier EVENTY-EIGHT pounds of stone is 2 heavy and awkward load to carry on a bicycle, and it is possible only through the logical design of the handle-bar and carrier basket illustrated. This enables the load to be perfectly balanced over the axle of the The load can be handled easier when the carrier becomes the handle-bar

front wheel. Handle-grips are fitted in the side of the twenty-two-inch basket. Ample knee room is provided, and the whole carrier is made so that it can be in- stalled in any standard seven-eighth-inch handle-bar socket. The advantages claimed are that the load cannot joggle nor sag. The basket is of heavy gage woven wire of one-and-one-half-inch mesh over a three-eighth-inch frame, and cannot be pulled out of shape by any load which a boy can lift on to a bicycle. The handle-grips are of coiled wire, and are boxed to give plenty of room for the fingers.

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ae Va ees aes ich ad vy ich nd ad “he TS. December, 1921 Electricity Heats Water as It Passes through Faucet Y means of an electric resistance coil nearly a foot long placed in the center of the water-pipe, this faucet will supply hot water at the rate of thirty gallons an hour. Its action is instantaneous, and there are no switches to turn, since moving the faucet handle to the left starts the electric cur- rent. A separate circuit of No. 14 wire must be used, as, like all electric water heaters, the amperage consumed would burn out the switches of a lamp socket, but the inven- tion should be a boon to mercantile estab- lishments handling unwrapped food. Al- though these use little hot water, the law requires that it shall be available at all times, and this electric precludes all danger of explosions and does not waste money by heating water which will never be used. Machine Makes Five Operations on One Piece of Work T= is another time-saving machine that will do as many as five operations on one piece of work. Five revolving tables are provided with vises. Each of the five vises holds a tool for a certain operation; such as reaming, drilling, countersinking, or tapping. The SPINDLES CARRYING TOOLS REVOLVING, 4) TABLE -— WITH j VISES After performing five different opera- tions, this machine automatically ejects the piece of work small vises on the revolving table hold the work and bring it under the tools pro- gressively. When an operation is completed on one piece, the table revolves and the work is advanced to the next tool, and so on, until the complete circuit is made. 67 Bamboo Clock Tells the Day, Week, Month, and Year pees the springs and the wheels of this eight-day pendulum clock were carved from bamboo with a penknife. With the exception of a ten-pound leaden weight which operates it and two small glasses which serve as gongs, the entire mechan- ism is constructed of cane such as is found in the ordinary bamboo fishing-pole. Its inventor and maker, Constance Renzi, a sixty-year-old clockmaker of Rome, spent the last two years whittling out the com- plicated works to show what Italian work- manship could accomplish with the crudest materials. He declares he could make a second clock in two months. The clock tells the hour, minute, and second, the day of the week, the month, and the year. It shows the phases of the _ moon, and strikes the hours and quarter hours, while an alarm actuated by a bam- boo spring will get its owner up in the morning. At noon, if desired, the works can be set so that a small flag is run up to the masthead, the raising being preceded by a whistle from a bamboo tube, and one minute after the noon hour the cannon at the top of the clock is discharged. An exceedingly clever method is used to prevent the escapement from wearing out. The escapement jaws engage spokes on a large wheel, and these spokes revolve loosely on bamboo pins, constantly pre- senting a new surface to the wear.. As bamboo is covered by an extremely hard siliceous coating, the clock will run for years, and comparison with ordinary clocks shows that it keeps excellent time. Mr. Renzi has already refused an offer of eight thousand dollars for his clock, which he hopes to sell to a museum. Mr. Renzi used nothing but bamboo in making his eight-day clock Pockets for Woman—in Her Hat! cpuilcahag ar tgheiteven lawyers used to carry their writs and pleadings in the crown of a battered hat, also a plug of tobacco, perhaps, and a bandana hand- kerchief. Note how the woman of 1921 revives this ancient method of “‘stashing’’ pocket things. Two customers of Peggy Hoyt, well known New York milliner, were found on the exclusive Shinnecock golf-course at Southampton, Long Island, with amethyst- colored sports hats that had folds specially designed to carry a cigarette-case, vanity mirror, and powder-puff—and the photo- graph shows them about to be demon- strated. In one hat the necessaries are merely slipped in and out of the folds, while in the other there is a flap with a snap-fastener. As a special service to readers, the Editor will be glad to supply the names and addresses of manufacturers of devices mentioned in Popular Science Monthly Combination Chair and Umbrella Makes Artists More Comfortable (COMPAISING everything an artist re- quires for an afternoon’s sketching, with the exception of the proper light and inspiration, the entire outfit weighs only six pounds. Folded, this camp-chair can A combination chair, sunshade, and portfolio of sketching tools for the rambling artist be carried easily in the hand or swung on to the back; open, and the artist has a jointed umbrella to keep off the sun, a mirror by which he may watch the country behind him and guard against the irate farmer who has sworn vengeance on the trespasser, a graduated rule for laying off his drawings, an eraser, which also serves as a plumb-bob, a bottle holding water for water-colors, and a waterproof bag to con- tain all these accessories while on the march. — t f Li eee a Speen a ses ena: x egy sere em cpmemre i are ee 4 ee eget : PE a ERE: bt tes aie 8

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t be . i i $3 fi 68 Popular Science Monthly Simple, Homemade Sterilizer for the Dairyman ROASTING-PAN, 2 galvanized iron cover with a spout soldered in the center, a metal box, and an oilstove—all arti- cles which can be bought at any hardware store or easily constructed at home —comprise a complete outfit for sterilizing dairy utensils by steam. . This simple method of sterilization has been worked out by the United States Department of Agriculture, which de- scribes the manner of operation as follows: The cans should be thoroughly cleaned and ized the same way, using the galvanized box. This outfit can be pro- vided at a cost of from ten to fifteen dollars, includ- ing the kerosene stove. The equipment of the usual small dairy can be thoroughly sterilized in forty minutes, and in ad- dition to a more sanitary product, the use of steril- ized utensils will keep milk fresh for a longer time. Dishes or implements that are clean are not necessarily free from bac- teria. Even milk that has been produced under the rinsed with washing pow- der, hot water, and a scrubbing - brush before they are ready for steril- izing. When they no longer feel oily or greasy, arrange the apparatus as the illus- tration indicates, and test the heat of the steam escaping through the spout with a thermometer. When this registers at least 205° F., put the can over the spout, and leave it there for five minutes. Use gloves A milkcan placed over this spout of live steam is made absolutely sterile in five minutes to remove the can, as it will be too hot to touch, let it drain five seconds, and then set it on the floor, mouth up. Within two or three minutes it will be perfectly dry, owing to the intense heat to which it has been subjected, and all bacteria will have been killed. The smaller implements are steril- A galvanized box supplies the sterilizing chamber for cream- separator parts closest scrutiny and with perfect cleanliness contains a few bacteria. Every time that milk or milk- containers are handled, a certain number of bacteria are added and it is only by ster- ilization at 212 degrees that these bacteria and germs can be killed. Realizing that the usual equipment was too bulky and complicated, the Department of Agriculture perfected this simple sterilizer. Miles away the words written by this man will reproduced automatic- ally on sensitized paper Write a Personal Message by Telephone aa res with a lead-pencil at one station and reproducing the hand- writing at another place is in itself nothing new, but when the reproduction is accom- plished by a minute beam of light acting on photographic paper, it is worth men- tioning. The illustration shows the send- ing station of an apparatus of this nature. The sender simply writes down what- ever he wishes to send on the roll of paper passing through his machine. Ten seconds later the message has been imprinted on a strip of sensitive paper and developed auto- matically in the receiving device. The ap- paratus may be used over any telephone or telegraph line already existing. Most “French” briar pipes actually come from Corsica. The Sicilian briar-root is considered the best. Spectroscope Detects _ the newest spectroscopic methods of analysis, one five hundred thousandth part of a drop of blood on a criminal’s cloth- ing is enough to convict him of murder. With the new system perfected by Professor Florence, of Lyons, France, the smaller the amount of blood, the more cer- tain and easy is its recognition. This is of immense advantage to criminologists, since when sharp weapons are withdrawn from a wound they are usually wiped clean of all but an infinitesimal amount of blood by the victim’s clothing, and the detection of the presence of human blood on the suspect’s knife is often impossible by chemical methods. Professor Florence makes photographs of the spectrum of blood, or of the blood corpuscles themselves while they remain on the object examined, so that if need be, the jury Minute Bloodstains The camera is so constructed that the degree of enlargement of the blood cor- puscles may be varied at will without changing the focus of the microscope. Sometimes, however, the form of the cor- puscles has been destroyed, and in these cases a spectroscope is used to afford posi- tive identification. With this method bloodstains scarcely to be seen on colored fabrics can be recog- nized. In one test, a single bloody thread, only 0.04 of an inch long, was placed under the microscope and treated with Virchow’s fluid mixed with a little honey to remove the dye and brighten the color of the blood- stain. Instantly the spectrum of hematin, characteristic of blood, appeared under the microscope—a complete proof of a crime, although only one five hundred thousandth part of a drop of blood was present. need not credit the testimony of the ex- pert, but can repeat the tests for them- selves. His appa- ratus consists of a microspectroscope in which a_ powerful beam of light is di- rected through the horizontal tube at the left on to the knife-blade beneath. When the scientist discovers a_ blood- stain, it is readily photographed by swinging the camera at the left into posi- tion over the micro- scope. Examination of the size-and shape of the blood cor- puscles determines whether or not the stain is that of a hu- man or of an animal. The apparatus of Professor Florence will detect the au. thenticity of blood- stains when only a minute sample is available. e in- sert shows a drop of blood greatly magnified

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il- er k- er or. ria ‘as mnt er. aly = ad, ler W'S ve yd - in, che ne, Ith of nce au. ya » is in- rop tly December, 1921 Indian Folk-Songs Are Preserved by the Government oo for burial, for marriage, and for birth, in fact, for every important occasion that arises in his life, are the kind of songs sung by the American Indian. Some of these songs had their beginnings when the Indian was master of the Ameri- can continent. Eventually the red man will be of the past, and so the United States Govern- ment is now having phonograph records made of the old Indian songs. That is what the splendid-looking Indian in the picture is doing—canning his tribal songs. Dark Stranger Appears in Space N astounding discovery by a Dutch scientist of a heavenly body twenty million times larger than the sun has introduced a new factor into astronomical circles. It is thought that the body is a huge cloud of dust that will eventually become a star. Measurements made of the dark mass show it to be 140,000,000,000,000 miles long and twice that far away from the earth. Odd Items of Interest from Around the World * e { mt | i | 1 I Man-Propelled Trolley in East Africa gresoageea in British East Africa, can show the foreign visitor a unique system of man-propelled trolleys that are deficient in speed, but with compensations such as cinderless travel and an unob- structed view. A covering, such as seen on a baby’s perambulator, shades the rider. No Contest to Occupy This White House peyvERy year the biggest turkey is shipped to the White House for the President’s Christmas dinner by the town or county that has raised the heaviest and finest bird, and this is the crate, in the form of a White House, in which the bird is shipped. There is no higher honor to which a turkey can aspire than to become the tenant of this crate. It marks him as the finest specimen in the land; but in spite of the distinction conferred, no turkey has as yet appeared eager for the nomination. Moving Roadway for Japan prosans Hill in Yokohama, Japan, separates the exclusive foreign colony from the shopping district and presents a serious obstacle to motor-cars and ricksha men, The city authorities have been asked for permission to construct a moving road- way leading over the hill. A Japanese engineer thought of the-idea, and purposes to operate the road by electricity, charging toll of all vehicles that use it. Delivering Beer with a Hose UL NPORSUNATELY, this chap is not delivering gasoline through the hose, but beer; still more unfortunately, he is delivering it in the British Isles. A scarcity of wooden kegs com- pelled the brewers to distribute Budweiser in tank-cars and motor-lorries. There was considerable complaint from those who feared the flavor of the beer would be spoiled by contact with galvanized iron and rubber, but these fears proved unfounded. The second hose on the rear of the wagon is used to deliver light beer. The tank is divided into two sections, and the other hose will be used as soon as this ‘‘public house” has been supplied with all the dark beer its patrons are likely to require. Shallow Draft Towboat for the Mississippi HE Natchez is the most powerful river towboat ever con- structed in this country or abroad. She will tow six steel barges, each 230 feet long by 45 feet beam with a maximum carrying capacity of 2000 tons. She is built of steel and equipped with oil-fuel boilers and two triple expansion engines. As the river is shallow at some points, the twin screws are set in tunnels built in the bottom of the ship, so that they cannot foul if the ship grounds on a sandbank. The flow of water to the propellers is unhindered, and four rudders, one placed both for- ward and aft of each propeller, make the maneuvering qualities of the Natchez excellent, and she can run full steam ahead in water as low as seven feet. Special compartmented metal tanks mounted on trucks are used to deliver beer in Great Britain The largest river towboat in the world has twin propellers revolving in tunnels to prevent fouling in shallow waters § } ' i i Hi Ta ee to Pom ~ para 2 St REE Ea SE OT RE Be SP eee Le IE OSE ali STON ia

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aia eascaga NR Tae Ret tg Se at ee, 70 Popular Science Monthly : From Ore to Capsule— Striking picture of the little known process of Photographs © U. S. Radium Corporatioa Carnotite ore, from which radium is obtained, is mined principally in Paradox Valley, New Mexico. The ore is placed in sacks and carried in teams over the rough country to the railroad. It requires about six hundred tons of carnotite ore to produce one gram of radium ‘”” Atthe refinery the first operation is the cleansing of the crude ore in huge brick vats. It is six months after this first step before the re- finement is complete and the radium ready for use During the refining process other valuable products» such as uranium and vanadium, are extracted from the ore by chemical treatment. Vanadium is an important element in steel manufacture The solution containing barium and radium salts in the ratio of ten parts of radium to a billion is treated with sulphates to precipitate an insoluble “raw sulphate of barium” Film-Projector and Screen in the Same Cabinet ICTURED here is a motion-picture pro- screen for showing the picture. A unique tent in the regular school activities of their classmates. The desk, or chair, has a special support jector that includes within one cabinet the necessary film-storage space and the on P The film is projected on to a screen set into the cover of the cabinet arrangement of prisms makes it possible for the picture to be projected outside the cabinet and on to a larger screen set at a distance for home use. Perhaps the most interesting feature about this cabinet is the method by which the film is stored so that by connecting the two ends correctly the film may be run con- tinuously as long as desired. A special safety device stops the motor driving the machine when the film breaks. The projector consists of the usual in- candescent lamp, intermittent movement revolving shutter and projecting lens. A steel fireproof cabinet is furnished for the safe storage of the film. Rolling Desk for the Use of Crippled Children "THERE are so many crippled children in our classrooms—in New York city alone seventeen hundred must be taken to school daily by automobile—that a special movable desk, shown in the picture at the right, has been designed to permit children unable to walk to participate to some ex- for the legs, and can be adjusted in every direction so that the child can rest in the most comfortable position. With this rolling desk crippled chil- dren can attend schools without discomfort

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December. 1921 The History of Radium refining six hundred tons of ore to a gram of radium From the filter presses the liquid containing radium is placed in crucibles over burners and carefully evapo- rated. In the room shown above the chem- ists have more than $500,000 worth of radium The four tiny crucibles contain the radium extracted from the original six hundred tons of ore. It has re- quired the labor of five hundred men for six months The fluid from the chemical vats is run into filter presses - and compressed between sheets of chamois-skin. liquid runs out it is tested for its percentage of radium As the The finished gram of radium, worth $120,000. In its pure state this sample of radium will remain active, giving off its emanations for approx- imately 1780 years Purdue Has World’s Largest Bass Drum [* is seven feet high and four feet from drumhead to drumhead. It is wheeled along on a little carrier during parade. When mounted on this the top is nine feet from the ground. The tone is deep and rather subdued, but it has a wonderful volume and resonant power that make this drum able to balance the most strenu- ous efforts of a 125-piece brass band. The world’s largest drum was not con- structed without difficulty. It took several months to find two bull hides large enough for the heads, which are one hundred inches in diameter. Such heads put a great strain on the shell, which required special re- enforcing and a novel type of screw-rod manipulators for varying the tension of the heads. After the instrument was com- pleted, it was found that the doors of the ordinary baggage-car are not large enough to admit it, and a special car will be neces- sary when the band goes on tour. Pontoons to Replace Ferries ONTOON bridges across Lake Wash- ington have been proposed to relieve congestion on the ferries of Seattle. Fifteen wooden vessels constructed for the United States Shipping Board would be used as floats, and upon them an eighteen-foot roadway and two four-foot sidewalks would be constructed. Drawbridges would be provided to permit navigation. As a special service to readers, the Editor will be glad to supply the names and the addresses of manu- facturers of devices mentioned in Popular Science Monthly Renews Blotting Surface after Each Operation BLOTTING-STAMP has been in- vented in Germany that constantly renews itself. Thin blotting-paper on a spool covers the bottom of the stamp and rewinds around an idler. Each time the stamp is pressed down, it pushes a little pawl that trips a ratchet gear, winding up the idler. Ame N RATCHET WINDING-ROLE, ROLL OF rx | 7 PLATE BLOTTING _- PAPER \ © wl 7m Nii Pinan rr | Ps ag te font foxy [ i SS A ratchet mechanism renews the blotting surface each time the blot- ter is u an iS iain on Sn ie PIR OCA IES eT Ry Ae seep areteneswens inte | , dl Hi 4 ‘ wi

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Popular Scvence Monthiy Shoes for Equine Bog-Trotters A ROUNDED wooden “ plank about one inch thick, fitted with staples and springs that fasten it firmly to a horse’s hoof, has proved useful when teams must be driven over soft bogs or loose sand. The horse puts his foot in the center of the plank, and when the clamps are fastened as indicated in the illustration, he may walk wherever he chooses without sinking into the soft soil. DOES a coral island grow from the top down or Disk Improves Phonograph Tone LEARER tone, a purer musical quality, and the total elimination of all seratching and scrap- ing noises are claimed for this phonograph attach- ment. It consists of a round ball into which the needle fits, with only about a thirty-second of an inch of the tip protrud- ing. The ball rests on the surface of the _ reeord. The disk is arranged par- allel with the record. In this way the inciden- tal vibrations imparted to the needle by dust in the groove or a worn path, from the bottom up? An American professor | is leading an expedition | are dissipated before they reach the reproducer, while the vibrations are passed to the South Seas to undampened. The music settle the question. Dar- win stated that the coral grew naturally from the bot- tom, but recent scientists con- tend differently, hence the expedition. Coral is a sub- stance secreted by the marine polyps. Curtain of Water Safeguards Books XTERNAL sprinkler systems have been installed along the eaves of the Chicago Public Library to protect the priceless volumes in the building from the danger of fire. In case a blaze starts in any of the structures near by, a wall of water falls from the roof of the library, extinguishing flying sparks and protecting the building against heat and smoke. produced is not loud, but sweet and clear. FEWER people are dying this year, according to the Metro- politan Life Insurance Com- pany, the death rate being 23 per cent below that for 1920. Hand Fire-Extinguisher Uses No Liquid OWDERED carbonate of soda and carbon dioxide gas are blown over a fire by this extinguisher, patented in Germany. The chemicals are dry and no water or sulphuric acid is used. The result is a great reduction in weight without loss of efficiency. The gas is compressed in a strong container. When the valve is opened, the gas is blown through the powdered soda, and the mixture blankets a fire without the danger of short circuiting electric wiring, which is the drawback of the liquid soda apparatus. In the test illustrated, a wooden structure, smeared with benzine and tar and burning furiously, was extinguished in ten seconds. - Building-Blocks Made on Continuous Molder aren by George C. Debay, of Springdale, Pennsylvania, this machine forms blocks accurately and rapidly at greatly reduced cost. The molding parts are carried on an endless conveyor. Each member forms the bottom and one side of the mold. The upper portion of the side of the mold member is made in movable sections. A side of the core-bar adapted to engage an opening formed in the side is provided, whereby the sections may be swung into position over the core-bar to enclose same. Plastic material is fed to the molds through a spiral conveyor. Dry chemicals instead of liquids. compose this fire-extin- guisher. he gas carries the powder to all parts. of the blaze and smothers it By placing the parts of the mold on a traveling conveyor, the manufacture of building is carried on con- tinuously

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» a wo ie. Bee ee. 6, mh Deceniber, 1921 73 When the cutting edge becomes dulled, it can be restored by drawing a file across both cutters. Do not attempt to file the outside edge of the bit head SPUR TH = > CUTTERS The cutter head must be kept in good condition to make the bit cut cleanly and evenly How to Get the Most from Your Bit No. 2 in a series showing How to Use and Care for Tools Sometimes, but not often, the spur—which is the sharp point that scores the wood and out- lines the hole—needs sharpen- ing. To do this, hold the bit as illustrated above and draw the file backward, filing lightly and on the inside only The illustration above shows very clearly how the screw, the spur, and the cutter work together in cutting away the wood and lifting it out of the hole MEDIUM Screw pitch varies with the size of bit and work. A quick thread is for rough work; a slow thread for fine work Pen sae Bicycle Steers from the Rear A® English inventor, Mr. Fenner, claims that his reversed bicycle is yery easy to ride uphill and unusually light on tires, since the weight is borne equally by both wheels. The mechanism of the usual bicycle is exactly reversed. The drive is from the front wheel and the steer- ing from the rear. The rear wheel is con- nected with the handle-bars by a rod attached to the crown’ at the head of the machine. This bicycle steers from the rear wheel and is driven from the front Why Do We Do It? Why do we run the engine with the garage door tightly closed? | Rageoene- sage gases from an auto- age of poisonous carbon monoxide —the fatal “fire damp” so dreaded by miners. When a cold engine is warmed up inside the garage, with the doors and windows tightly closed, enough of this gas is pro- duced to constitute a serious fire risk and danger of explosion. Breathing it for only a few minutes may cause a prolonged headache. Carbon monoxide combines in- stantly with the hemoglobin of the rec. corpuscles of the blood to form a stable chemical compound that persists for hours, even in the open air. During that time the cor- uscles are unable to absorb oxygen rom the air. The effects of breath- ing carbon monoxide for a few minutes are the same as those that would follow the temporary loss of a pint of blood. Open the garage door when the engine is cael WHAT DO YoU DO —that you know you shouldn’t? | What are some of the familiar prac- tices of every-day life that we all | | warely try to conquer? Send your suggestions to the Editor mobile contain a large percent- | | know are stupid and yet that we Plowing with a Street-Car ECENTLY, when the Sioux Fails traction system had found it neces- sary to plow up the roadway in order to install a switch, they decided to use their own power for this work. To one of their work-cars they fastened as a side outrigger a ten by ten inch timber, fastened to which was an extra heavy breaking plow. The heavy chain which pulled the plow could be slid back and forth on the out- rigger timbers, in order to adjust the posi- tion of the furrow. The improvised work- car plow accomplished more in three hours than could have been done in a day’s time with teams. Outrigger and plow used Ne a Sioux F company to tear up the roadbed spe pe ae eer Stee AS TPE eT a PASE Se ‘ We pane Ng ncinnst Se Mh no srk ot vege oka

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74 Try These Speed Indicators on Your Mental Gears A Course in Quick Thinking, conducted by Sam Loyd Lighting the Boulevard FTER the trustees of a small township had voted an appropriation to pro- vide for a fixed number of electric-light poles to. skirt the main highway through their bailiwick, the Ways and Means Com- mittee made a report to the effect that if the poles were set 440 yards apart, as had been suggested, they would need three more poles, whereas if they were erected three quarters of a mile apart, there would be three poles left over. There were the usual divergences of opinion that are so familiar to all small- town meetings, and after listening to the individual view of each trustee, the chair- man decided to settle the matter himself. “Go ahead and use the poles provided for,” he ordered; ‘have them equi- distant apart and see that you use all of them.” If the chairman’s orders were carried out, and the extreme poles stood on the town’s boundary lines, what was the distance between poles? $25 in Prizes | agreeing ey say that puzzle-solving is the best kind of mind-training — best, because it comes as sport instead of drudgery. As proof of this, consider the fact that Sam Loyd’s most faithful puzzle fans have been inventors, engineers, and business men. A first prize of $10 will be awarded the reader who sends in the best set of correct answers and analyses covering the four problems on this page; a second prize of $5 for the next best set; and ten other prizes of $1 for the ten next best sets. Answers must be received not later than January 9, addressed to the Puzzle Editor, Popular Science Monthly, 225 West 39th St., New York, N. Y. By “best” is meant absolute correctness of solution—then, if other points must be * considered, clearness of analysis. Mr. Loyd’s decision must be considered as final. In case of a tie, each competitor will be awarded the full amount of the prize tied for. Answe-s and names of the prize-winners will be published in the April issue. A Practical Referee Settles the Question Popular Science Monthly How Much Was Offered? REAL-ESTATE dealer was endeavoring to sell an old condemned building to a house-wrecker, of course, for the best price that he could get. The wrecker didn’t think much of the condemned struc- ture, but was willing to do business on a basis of $1500 less than the owner’s asking price. After going over. his-figures- -several times more, the owner finally came down 25 per cent in his demand, but tkere still remained a difference of $1250 between the owner’s and the wrecker’s figures, and the deal was declared off. What was the wrecker’s offer? § 9 $00-0 eo? eer wrangling heirs, who were equally interested in a certain piece of land, took a map of the property to an attorney and begged him to make an ad- justment so that there should be no more wrangling. After giving the matter due considera- tion, in Solomon-like manner the attorney picked up his shears, and cutting the blue- print into eight sections, g&vé one to each. “There, you each have a piece cf the same shape and size. Divide your property likewise.” The miter-shaped diagram in the illus- tration is of the property in question. Who can duplicate the attorney’s feat and mark off the figure into eight sections cf similar shape and size? may be presented as follows: When Were the Cars Nearest Together? Two friends who had been automobiling through the same section of the country, without being aware of each other’s whereabouts, subsequently found it interest- ing to figure out how close they had come to meeting. It appears that A came from the north on a highway that crossed at right angles another road, running due east and west, on which B at the same time was moving eastward. Thus their data resolved into a problem that A and B started from north and west simultaneously, A going from north to south at the rate of 32 miles an hour; B going west to east at the rate of 24 miles an hour. From A’s northern starting-point to the crossroads is 60 miles; from B’s western starting-point it is 70 miles. If they started their journeys at 12 o’clock, noon, and traveled steadily for three hours at their respective speeds, at what time were the two cars closest together? i Nagy: , ay eee Nop: ae f “Rp ‘

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I ee tae sas December, 1921 For the Comfort An adjustable light com- bined with a smoking- stand will give the final touch of comfort to a wintry evening at home by your own fireside 9 The electric wires woven into the fibers of this blanket are connected with an ordinary lamp- socket and the current keeps the patient comfortably warm A portable fumigating outfit for the sickroom, consisting of a pump in whick the disinfectant is placed and a flexible tube lead- ing to a keyhole in the door of the room to be fumigated When not used for dish-washing this mix- ing link can be turned back so that the water will run down the sink- side without splashing everything in sight This attachment is for sewing heavy material. After the needle is pushed into the fabric, a vise arrangement pulls it through USED FIRST DAY and Convenience of the Family Be sure of the quality of rubber rings before food is placed in jars. A good rubber ring should sup- port: the equivalent of a gallon and a half of water 75 ” The light from gas-mantles can be increased by steeping them in vine- gar. It is also claimed that this makes the mantles stronger By cutting the cake as sho «:, it may be consumed down to the !-ct crumb withou%becoming dried due to exposure A dasher blade in the base of this dish-washer throws a cleans- ing stream of water over every dish and cleans a trayful in less than a minute. It is operated by a motor A deodorizer and night-lamp can be made by placing a small cake of gum camphor in a shallow dish of water and light- ing the camphor Teeth lengths, those found in the of different similar to woodsman’s_ crosscut saw, make it possible to cut new cake into very thin slices ¥ ‘| i t i Yh » a ; t % ie Ay ' iu i ou ? Ht ¢ 4 Cae er ee as mae a TE

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peels Pee ead a tg eee oe ene ae SR ri ma pee oe 76 He Gave the World an Improved Battery Newly invented process reduces weeks to seconds in forming battery plates FUNDAMENTAL improvement in battery manufacture that reduces the time required to form a lead plate from «weeks to seconds has been made by Pedro G. Salom, of Philadelphia, for thirty-five years a prominent figure in the manufac- ture of storage batteries. The new battery is not only cheaper in cost, but it will increase the voltage 5 per cent over that possible with “pasted” battery plates, and will enlarge the capacity more than 25 per cent. It is said to be the first basic improvement to be made for more than forty years— since 1881. Salom forms negative plates by applying the spongy lead directly to the grid by hydrau- lie pressure. It is one opera- tion, finished in a few seconds. Other processes laboriously build up a spongy lead plate by pasting litharge on the grid by hand, later converting this oxide to spongy lead by slow, laborious electrolytic processes that take weeks. The oxides must be pasted, dried, formed, cured, and developed. Under the Salom method, the material is simply applied at a pressure of fifteen hundred pounds to the square inch, and the battery is ready for use. Manufacture becomes a direct process instead of an indirect one. The improvement in operation is due to the fact that the enormous pressure exerted in squeezing the active material into the grid establishes a mass conductivity not possible to obtain by hand work. The improved storage battery is the out- A row of electrolytic cells in which the come of an earlier discovery of Mr. Salom’s, by which he improved the process of reducing lead from the ore by electrolytic methods. Under this method the lead is recovered in the spongy form, precisely as it is found on a fully charged negative storage-battery plate, and, familiar as Mr. Salom was with storage batteries, it seemed Ss Popular Science Monthly Pedro G. Salom, inventor of a method to reduce the process of lead-plate formation from weeks to seconds is washed in water and then dried to the exact degree, which arrests a superficial oxidation of the lead at just the proper stage, it might be compressed on to the grid without destroy- ing its spongy nature. If the mass is too dry, or too moist, it is pressed into a solid sheet, useless for storage-battery work. The lead peroxide is the Salom grids is produce to him wasteful to convert this spongy lead into litharge, send it to the battery manu- facturer, only to have him paste it on the grid and reconvert it into spongy lead again. His training as an electro-chemical engineer made him able to produce the active constituents of storage batteries, namely spongy lead and lead peroxide, in bulk. The difficulty was to hit on a process of applying them to the grid. He found that if a mass of spongy lead poney lead for moistened and pressed on the positive plate in a similar way, a special binder being used. As a result the plates hold more active material, and the voltage and life of the battery are increased. To dem- onstrate the superiority of his invention, Mr. Salom constructed a miniature plant, which he set up in the factories of the leading manufacturers of automobiles throughout the country. He made his battery plates before their eyes, put them in a standard container, and allowed the automobile engineers to run comparative tests with the best “paste plate’”’ batteries. Vacuum Cleaner for Automobile $ ose compact vacuum cleaner has been made unusually light and portable with a long electric cord so that it can be carried into every nook and corner of the car. A limousine is rather hard to clean, and the amount of dust that sifts through the win- dows in a day’s travel is surprising. In spite of its small size the vacuum cleaner will do the indoor housecleaning as well as the larger machine. It operates on either alternating or direct current. A Jeweler’s Idea of Car-Building A dated a Fifth Avenue jeweler adopts automobile-body building as an avo- cation, the result is likely to show the effect of his professional love of fine finish and beauty of line. As the illustration shows, the jeweler has left the beaten paths of motcr-car design. He took a special spert chassis, built in 1915, with a wheelbase of 143 inches and an engine of seventy-five horsepower. He stripped off the old-fashioned body and built on the rugged frame a car that is ultra modern in every respect. For instance, the mudguards are double, in order to hide the supporting bolts, and are heavily outlined in brass to prevent rattles and squeaks. A brass strip, so attached that no screws or nails show, runs along the entire upper edge of the body behind the cowl. A dashboard of alumi- num was installed containing speedometer, altimeter, cigar-lighter, pressure-gage, am- meter, voltmeter, motometer, clock, oil indicator, lighting buttons and _ switch. The cutout was ingeniously placed on the steering column, while the _ air-pump, choker, and other instruments were placed on the side of the car within easy reach of the driver’s right hand. A special spotlight, with a long handle was another novelty. oe When a jew.» set his hand to automobile design, this was the result. Virtually eve: » part is a radical ¢ »parture from conventional plans

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A el ee cl —— = oe eae aS lo a A ne i i el 2 ee a a we we December, 1921 New Steam-Car Has Engines on Rear Wheels HE thousand-dollar steam-car is now in process of production. It is an attrac- tive, five-passenger machine of conserva- tive design. The boiler is placed under the hood, with the engine located in the rear axle, where it takes the place of the usual differential mechanism. Three cyl- inders drive each rear wheel direct without intermediate gears. Each three cylinders are disposed at 120 degrees and their pis- tons are connected with a common crank- throw, which is merely an extension of the axle-shaft that runs to the wheel. Inas- much as each wheel has its own engine, no differential mechanism is required. In fact, there are no gears at all in the rear axle. Exhaust steam is delivered to the radi- ator, which acts as a condenser. Trans- mission of steam to and from the rear axle is through two pipes, the top one connecting boiler and engine and the bottom one the engine and radiator. The lower pipe also acts as a torque tube, relieving the car- springs of driving and torque strains. The forward end of this pipe ter- minates in a ball joint. The exhaust steam from the engine is condensed in the radiator and flows to a small water-tank, from whence a pump forces it into the boiler. The boiler is a water-tube operating at six hundred pounds pressure and the fuel used is kerosene. This new steam-car, in common with all recent designs, employs the principle of intermittent boiler opera- A broken-away view of the steam-car and its boiler and driving mechanism. The steam _ gener- ated under the hood is carried by long Pipes to the engines on the rear axles tion. In years gone by, steam-cars, like locomotives and stationary power plants, operated on a constant boiler pressure, and the feeding of fuel, air, and water was varied to keep constant pressure. In order to make this work automatic, the machine was loaded with complicated devices that had much to do with the decadence of the steam principle in past years. ‘EXHAUST PIPE TO RADIATOR ee Be nee ee eee S-CYL. ENGINE The modern idea is to operate the boiler intermittently. For example, when the pressure reaches six hundred pounds, fuel, air, and water pumps stop working, and the fire under the boiler goes out. When the pressure drops to, say, five hundred and fifty pounds, perhaps a minute later all three pumps start again, a spark-plug lights the fire and the boiler runs full blast LRADIATOR- CONDENSER, until the pressure rises again to six a = rast 7 ; Is easy tosee that the operation o a { Seen _ ——_ this system is simplicity itself. Fuel, . water, and air pumps are driven by a single electric motor. When the pres- sure drops to five hundred and fifty pounds, the circuit is closed; and when it reaches six hundred pounds it is automatically opened. Current for the electric motor that keeps everything going is supplied from the regular lighting circuit. The generator that supplies the storage battery is located under the floor boards and is driven by a long shaft from the rear axle. "TWO: 3-CYL ENGINES EXHAUST PIPE aa AND TORQUE TUBE “““"“SSgeee The chassis of the low-priced steam-car. Its steaming action is automatic and is regulated by an electric motor fed from the lighting system. There are no gears in the car, the position of the engines eliminating all need for differentials Fan-Belt Drives Tire-Pump OMETHING new in automobile accessories is a rotary power-driven tire-pump that occupies less room in the toolbox than the ordinary hand pump. The pump consists of a wheel that is rotated against the fan-belt and which is the cylinder of the pump. The rotation of the cylinder actuates an eccentric that oper- ates through a hole in the cylinder and delivers the power to the piston of large diameter and short stroke. This takes in the air through a shaft containing a port, which opens and closes for the admission of air. The air is compressed and forced through a mohair-covered tube attached to the tire-valve. The handle provides means for attachment to the car through a bracket that is bolted behind the fan-belt. The spring from the bracket to the handle of the pump maintains the necessary friction to insure rotation of the cylinder by the power from the fan-belt. The entire device weighs less than four pounds. Keep Axle Grease off the Brakes T= grease in the axles of Ford and Chevrolet cars will often work out through the axle housing on to the brakes. If this should happen through wear of the axle parts, the trouble may be eliminated by a new device made especially [tm for the two makes of cars men- tioned. The device consists of a single steel spiral spring that fits closely to the axle-shaft. The pulley of this rota ump driven from the fan-belt ie also Odd Safety Signal on Fender Am automobile safety signal that operates on the principle of visible indications by means of illuminated cross-arms has been tested and ap- proved by boards of safety of at least one large city. The signal takes the shape of a Maltese cross with a light-bulb in each arm and in the center. In the daytime the transparencies show black when not illuminated, but when a signal is to be displayed the black is changed to the color of old-gold, which can beread one hundred feet away, even in bright ; sunlight. At night, when the a oe Some eke contrast is greater, the same ed, this signal warns ‘Signals can be read for five other drivers that the or six hundred feet. Stat atart re A small hemispherical nine combinations to 8Witch with two levers forms indicate the inten- the operating mechanism. tions of the driver Any signal desired may be shown by a single movement. Placed on the left fender, the signal is visible to the cars ahead and to those behind. A special code that in its various combinations informs other drivers of the next movement of the car, has been devised. . WHEN the Underwriters’ Laboratories receive an automobile bumper for testing, it is mounted on a stripped chassis frame bolted to a concrete floor. A short length of 24-inch pipe filled with concrete and weighing about six hundred and fifty pounds is sus- pended by a 62-foot cable immediately in front of the bumper, pulled back twenty-four feet, and released. The impact of the weight equals that of an automobile the pump cylinder It revolves with the live axle-shaft and works the escaping weighing two tons traveling four miles an hour, and the shape of grease back toward the differential housing. the pipe simulates collision with a telegraph-pole. The effec- To install them it is necessary only to slip the springs over the tiveness of a bumper depends on the security of its fastening. axle-shaft and replace the bearings and wheels. The tests seldom break the bumper itself.

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EC ay See A GS RN ST a een Tenens 78 S a Special Service to Readers the Editor will be glad to furnish the names of firms manufacturing the interesting devices and accessories for motor-cars illustrated on ; these pages. Popular Science Monthly DiAL INDICATOR Whether the tempera- ture be above or be- low zero, this gage gives the correct grav- ity of the gasoline being sold to you by the pumping station. It is a combination of thermometer and hy- drometer Three feelers extending from the vertical rod detect the slightest un- evenness in cylinder walls and transmit the degree of eccentricity to the dial. Any measurements between two and one half and six and one half inches may be made A long leverage on the tire-lifter eliminates heavy lifting and makes tire-changing easier for the woman diiver, besides doing away with the possibility of soiling the clothes This tire-spreader is different from many others in the fact that ten metal fingers open the tire at points entirely around its circumference A connection between bus door and gear-shift makes it certain that the bus cannot be started until the door has been securely closed. The same lever also slides the steps into and out of position 6 i entity It is possible to exert a pressure of several hundred pounds with this pressure type oil and grease cup. A slight turn of the cap is sufficient to thrust the grease to all parts of the bearing When the oil in the engine needs renewing, it is shown by the jet of oil that rises in its arc and passes the mercury in the thermometer Sometimes the spacing of the points in a spark-plug is wrong. This tester makes it possible to watch the plug in actual operation. Plate- glass covers the aperture The tire moves around the in- spection machine on rollers, while a pressure on the foot lever spreads the beads of the tire wide open and expedites inspection

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December, 1921 But write. When You Want Expert Advice About Your Car N these six pages of ideas about automo- biles and motor-trucks Popular Science Monthly endeavors to help its readers solve problems of maintenance and repair. there must be special cases that are not cov- ered, and we invite you to write to the Auto- mobile Editor and let him advise you. If you wish to know more about the devices pictured here, or if you want to ask questions, See a few typical answers on page 81. The petty thief is frustrated if the moto- meter and radiator cap are secured by means of the anchor-like pro- tective device pictured above 50 CR ‘ELECTRIC PARTITION LAMP SCREEN. . — aie The new English anti-glare attachment pictured above in cut-away view can be fixed to any headlight of conventional type. The split-lens construc- tion eliminates all rays more than shoulder high TO INTAKE MANIFOLD By virtue of its hinged, split-frame construction, the front and rear wheels of this new tractor can be tipped at™ opposite angles, as pictured. The ma- chine has the same speed and power whether going backward or forward = a cae TWO HALF The most interesting development in the automobile world today is the in- crease of intercity travel in specially constructed ‘‘luxury” motor-buses. Read the remarkable article on this subject in Popular Science Monthly next month. © Kadel & Herbert This equipment, built on the vacuum-feed principle, keeps the automobile radiator filled by con- densing and returning escaping steam. When leaks develop, a warning whistle blows A new running-board tool-chest for motorists consists of three trays, each with depressions into which the appropriate tools fit snugly. Piled one on top of the other, the trays are locked together by means of the steel band shown The radiator will never freeze up overnight if the garage is equipped with this heater. The motorist simply places it on the engine and turns the switch This new utility wrench, with its four hexagonal openings be- sides the large one in the center, can be used with every size of rim lug Steering column headlights blinding rays tg, nih eine With this compressed-air apparatus the garageman can dispense meas- ured quantities of heavy lubricant direct from the original container. The hose connects to crankcase, differential, etc. of the above type can be tilted forward by a small lever when it is desired to protect the driver of an oncoming car from their Ete ee ea ee Ct OS SPLOT 2 { , &- ht

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Fie aS f } A Ppcawentlen stench ye” ig to toa gates a aecaloee a tcpen en Ss Popular Science Monthly Why I Believe You Should Buy a New Car It looks better, gives greater riding comfort, and has more labor-saving accessories than the used car now, I should buy a new one, just as I bought a new one the last time, and the time before. I get far more satisfac- tion out of a new car than I could possibly get out of the amount of money I might save by buying an older one. But my real reason for pur- chasing a new car would be a utilitarian one. I use my car in my business quite as much as I drive it for pleasure. Hence, I cannot be annoyed with the petty troubles that invariably complicate life for the average used-car driver. From a busi- ness point of view these annoy- |: I were to buy another car - By S. P. McMinn NEVER before to our knowledge have the respective merits of the New and Used Car been exhaustively argued in print. Last month Popular Science Monthly published a motor expert’s plea for the Used Car. On this page the other side of the argument is now presented. Winter is the time to buy used cars. The spring automobile shows will soon be here with their galaxies of new cars. These articles will help you form an intelli- gent opinion as to which type of car to buy. you back about $120. Now add that to the original cost of your used car. But with my new car I have no tire trouble for thousands of miles. Punctures don’t annoy me because the tires are so new that ordinary tacks and nails don’t penetrate them. Blow- outs are unknown. I roll along for 8000, 10,000 miles—I got better than 11,000 out of the tires on my present car—and literally don’t know there is rubber under me. Another important reason why I shall buy a new ear is because it is modern. Improvements are constantly being made in auto- ances represent time lost; and when I drive for recreation, mobiles. They are not made for the mere pleasure of mak- delays to fix one thing and adjust another are a nuisance, and often an expense as well. But my new car runs like the proverbial top from the time I step on the starter until I shut her off in the garage. I’m not worried with ignition wiring dropping off, with a gripping or slipping clutch, with faulty brakes or a grind in the rear end— all the results of some one else’s careless or ignorant driving. I don’t have to be eter- nally tightening nuts and bolts, or, as more generally is the case, chipping them off with a cold chisel and a hammer because the former owner never touched them and they have rusted solid. Of course some few minor adjustments are likely to be necessary after the first few hundred miles of driving. That’s to be expected. But they are adjustments that are easily made by any one. And if the owner cannot make them or does not care to, he has always the manufacturer’s service station to fall back on. For remember, the new car is guaranteed by the maker for ninety days under a guar- antee that the dealer causes to include any- thing that may prevent that car from giving perfect service. This takes in all those minor but necessary adjustments. The dealer is not only willing to give the service, but is anxious to do so, for his best adver- Easy riding depends on spring design and suspension. he comparative resiliency of springs in new and used cars can be easily demonstrated as shown above Tests show that in a used car imper- fect combustion permits condensed gas to leak into the crankcase, diluting the oil tising is word-of-mouth advertising—satis- fied-customer advertising. Thus, I place Freedom from Trouble high on the list of reasons why I will buy a new car next time. Freedom from trouble also means safety. I do not know, and have no means of knowing, in buying a used car, what parts may have been strained to the point where they are likely to let go and put my life and the lives of my passengers in danger. piston-rings— Tires are among a danger spot in And tires. the most deceptive things about a car, particularly to the average person, who knows little or noth- ing about them. Often enough they fool the expert. They look all right, good for thousands of miles— generally, because the person who is selling the car has “dolled” them up to look that way. But it is the inside of the tire that tells the story, and you can’t see the inside. Even if you could, you would have to take the car or leave it—with the tires it had on it. So you’d buy new tires—not right away, perhaps, but before you had driven it very far. Even if it is a very small car, four tires, not counting the spare, will cost in the neighborhood of $80. If you buy good cord tires, which, by the way, are a real investment, then they will set old cars ing them. They are necessary improvements. They are improvements that have to do with economy, flexibility, smooth-running and safety. On the score of economy alone a modern car is miles ahead of a car that is even so little as a year old. Our gasoline is getting worse every day. It’s about all an old car can do torun on it atall. But my new car is designed from the ground up to use just exactly the grade of fuel I get everywhere all over the countryside. It is designed to use some of the heat of the burning fuel in order to make the rest of it burn economically —that is with the ut- most efficiency. Then, too, unless the fuel is completely burned, it condenses and gets down past the piston-rings into the crankcase, where it dilutes the oil. The result is that this oil is used up far more rapidly than it should be, which means a big oil-bill. An even worse result is that the bearings and pistons are improperly lubricated. This in turn means sloppy pistons, worn rings, and per- haps scored cylinders. It may also mean burned-out connecting-rod or main bear- ings. That’s one reason why all the oil com- panies advocate heavy oil for old cars. They simply allow for the dilution they know is occurring. Also, an important point to bear New cars have no scored pistons and worn piston-rings. Because of this, they run more silently, with lower fuel cost and greater reserve power

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w= € OT OO oS ‘ie) - tiore Gaerws —-§ Yan Ww CO OO OS a le December, 1921 in mind is that the heavy oil quiets an otherwise worn and noisy motor. Then there is the ease of control. As I said before, I drive my car in my business and also for pleasure. As a business car it must not be unduly fatiguing to drive. And pleasure driving must be pleasure, not work. Old cars steer hard, due to faulty construction, to wear in the steering parts, or to lack of lubrication. Better design in my new car has brought about a proper proportioning of the linkage and leverage and therefore it steers easily and requires little lubrication. What lubrication it needs is taken care of by a little jigger of a grease-cup to which I fit a big grease-gun, and force the lubricant where it ought to go—force out the old, tired grease, and force in the new. Inci- dentally, every other part of my new car is lubricated in the same way. A two-hour, mussy, dirty equipment I get with my new car. There are side cur- tains that open with the doors and really fit properly—not jammed under the rear seat, wrinkled and torn and with half the celluloid gone. They are put on in a second and taken off as quickly. They are not a Chinese puz- zle even to my wife. -. Clutch- : springs — My new top more flex- 1s a one-man ible top, put up easily in a Better-proportioned linkage, : clutch-springs make it possibleto operate a cient. My demountable minute or modern clutch with less effort 81 Cluteh- 'Woand pedal—has folding com- long lever pactly out of the way when I don’t want it. My speedom- eter is geared to the gearset and so I don’t have any trouble with fiber gears chewing up through their inability to chew up the road gravel they feed on. Nor does my speedom- eter cable freeze in winter and break, or run foul of a tire. My lever- and lights are modern and effi- rims fit properly. On the score of materials job on an old-style car be- comes a nice, clean, fifteen- minute job on my new one. And everything is lubri- cated properly: Clutch-springs are heavy in old cars, and so are the springs that hold the brakes off. This means leg strain. It means a tendency to “ride” the clutch, and this a wears out the clutch collar Easy to bearings in short order. On oo my new car, on the other hand, I can release the clutch with one finger and bring the car to a stop with the lightest imaginable touch of the service brake. The answer is summed up in better, more modern design coupled with better le lubricating methods. They. A in Steering - ea r= Better link- age and lu- brication roads Spring suspen- sion — Easier rid- ing over rough that go to make up my new car I know that the maker has used vanadium and mo- ; lybdenum steel so the parts pony: pot may be made smaller and freedom lighter, easier on tires and a ee miser for gasoline and oil. For roadability and rid- ability my new car is far better than a used car. And my new car is a better in- vestment than a used car, as witness my own experi- ence. I bought a new car that cost me $1040, deliv- ered. It came to me brand new, shiny, beautiful. It ran perfectly. I drove it for a little over a year, cov- ering approximately 11,000 miles, and sold it for'$850 cash. In that year I never had it near a service sta- hotograph of the fore part of a modern chassis, tion, never stopped on the mean easy control. They icating the author’s points of saguatauity of the new road for trouble of any kind, make it fun to drive. car over the ol And now look at the and never spent a penny for repairs. Advice to New Driver Q.—I have just taken delivery on my first car. What advice can you give me regarding driving or care of it?—G. A. M., Tallahassee, Florida. A.—As to driving, be twice as careful under all circumstances as you think that you ought to be. Keep your eyes open and use your imagination. Thus you should be able to foresee almost any road crisis. Treat your car with as much sympa- thy as you would a thoroughbred horse. Never abuse it or neglect it. Above you give it plenty of oil and grease, it will last indefinitely. Inspect it once a month for loose nuts, worn insulation, ete. Never take anything for granted—a little scrap of advice as important as it is difficult to keep in mind. Horsepower Formula Q.—Can you give me an accurate horse- power form ula?—D. D. B., Fargo, S. D. A.—There are so many variable fac- tors in an automobile engine that no simple formula can be more than all, do not neglect its lubrication. If © Write to Us About Your Motor Troubles If you have a motor-truck or automobile problem, let the Automobile Editor solve it approximate. On the average the fol- lowing will give fairly good results: D’NSR 15,000 where D is the bore in inches, N the number of cylinders, S the stroke in inches, and R the revolutions a minute. Horsepower = When Building a Garage Q.—What dimensions would you advise for building a vate garage to house a single car ?—M, -, Peoria, Ill A.—In building a private garage it frequently happens that the structure is cramped and poorly lighted. Good light and sufficient space aroynd the car to we of easy movement are essential. A margin of at least 3 feet should be allowed both at the sides and the rear. The size of the average car is approximately 6 by 15 feet, so that the dimensions of the building should be 12 by 21 feet. If the car is a Ford, the building may be reduced to 12 by 17 feet. Alargecar, . such as a 66-horsepower car, should have a building 12 by 24 feet. -There should. be several windows. ‘ that no steering-gear is fully “‘irrevers- Blowouts at High Speed Q.—Why is a blowout dangerous at high speed ?—M. D. McL., Oakland, Calif. A.—A blowout in a front wheel is dan- gerous unless the steering-wheel is firmly grasped with both hands; this state- ment applies to ali speeds in excess of about thirty miles an hour. A blowout in either front or rear wheel is dangerous on a turn which is being taken at a fast rate, because it greatly increases the car’s tendency to skid, and in many cases this increase is enough to cause an accident. If a car is running fifty miles an hour, and a blowout occurs in the right front wheel, the steering-wheel will be wrenched to the right and the car will swerve sharply in that direction unless the driver is prepared for just such an emergency. The explanation is ible,” and the extra resistance caused by the flat tire rolling along the road, swings the front wheels in that direc- tion. Most of the accidents blamed on defective steering-gears are caused by unexpected front-wheel blowouts. i i seescestaneresos = i i |

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od 4 eng wee eats: a I ty i ati alg RE SG Se aoe ee ee peed oe Build a Homemade Water-Pump By W. A. Logan Feom an old motorcycle engine a suc- tion water-pump may be built that will prove of great usefulness for many pur- poses. The timing gears of the engine should be made equal instead of leaving them at 2 to 1. This change allows the discharge valve, which was formerly the ex- haust valve of the motorcycle engine, to open at every up stroke of the piston. The inlet or suc- tion valve is made of standard pipe-fittings and is screwed into the spark-plug hole. This valve may easily be made at any plumbing-shop from standard -in. T, with an old valve- stem ground down to fit. The stem should run through a hole drilled in the plug that is screwed in the pm old motorcycle engine may be restored to usefulness as a water- pump as here illustrated top of the T. The end of the stem is fitted with a spiral spring and cotter-pin. The spring should be of light tension, so that it allows the valve to open automatically as the piston descends, but closing it when the reverse stroke begins. At the same time the discharge valve opens and through it the water drawn in the cylinder is forced out. It will be found that about 55 revolutions a minute is the best speed, giving approx- imately one impulse a second. The speed is calculated from the number of revolutions of the power pulley, its diameter, and the diameter of the pump pulley. The end of the suction hose should be provided with ascreen to keep out the dirt that would interfere with valve action. Adjust Radius or Torque Rods to Prevent Skidding HEN an automobile skids with the least cause and sometimes apparently without cause, the radius rods or torque tubes which hold the rear axle perpendicu- lar to the center of the car are the reason. A bend or incorrect adjustment of one of these rods throws the center of the axle around and the wheels do not track, but tend to roll in an independent course. The rear end is naturally inclined to follow the wheels and skidding is the result. This is one of the seldom suspected causes of skidding and the remedy is to take accurate measurements from the yoke- bolts at each side of the front axle to the rear axle and adjust or straighten the rods as required until the measurements are exactly alike.—G. A. LUERS. YORSuts RADIUS RODS. Incorrect adjustment of the torque rods will cause skidding and should * Be remedied Device for Spreading the Springs of Automobiles T= main portion of the device shown in the illustration is formed by a 14-in. monkey-wrench, the handle of which had been cut off with a hacksaw 6% in. from the jaw. Near the end from which the handle was cut, and at a right angle to its longitudinal axis, a rectangular groove is cut, 1 in. wide and half the thickness of the steel. A piece of steel, 34 in. thick, 1 in. wide, and 1% in. long, is similarly cut at one end so as to fit in the groove near the end of the wrench-bar. The two parts are then drilled and threaded for two machine-screws that hold them together. The free end of the set-in Were You a Gipsy- Motorist This Summer ? D!P you answer the call of the open road this year? Did the running-boards of the “old bus” groan beneath their loads of tenting, bed- ding, eatables, and utensils? Tell us how much your trip cost, where and by what route you went, what big les- sons you learned that will help others make plans for a similar vacation next year, and, finally, what automobile, camping equipment you pur- chased or improvised. For the most interesting and informative letter, $35 will be paid; for the second best, $15. Letters must not be more than 500 words long, and must be received on or | before January 10, 1922. piece of steel is drilled and threaded for a 54-in. set-screw. The set-screw has a square end fitting a — SW DETAIL OF WEDGE DETAIL OF SCREW With this device the leaves of auto- mobile springs are easily oiled Popular Science Monthly key or wrench at one end, while the other end is turned down in the lathe and pro- vided with a groove into which a round- headed machine-screw fits. The sliding jaw of the wrench is cut off square and cut out to receive a small block of steel, drilled to receive the blind end of the set-screw. Two rivets hold the block and the jaw - together and the round-headed machine- screw already mentioned fits into the groove of the set-screw. The two pieces that wedge the springs apart are made of Y-in. round drill-rod. The points are ground or filed to the shape indicated in the picture and then tempered. Let Your Ford Help in the Farm Work N the small farm the possession of a Ford is a valuable asset. Its sturdy engine may be employed to furnish the power required for driving or operating a variety of farm machinery, from a simple hoist to a sawmill or feed-cutter. It is an RADIUS ROD . \\ \ f HUB-FLANGE \ AND BOLTS—X WOODEN _ RULLEY REAR-AXLE, HOUSING ARAKE* DRUM Attach a pulley to the rear axle of your Ford and it will run your farm machinery extremely easy matter to harness the Ford engine to almost any mechanical task by providing for it a pulley as shown in the illustration. Remove one of the jacked-up drive- wheels of the car and put in its place a pulley made of an old rear hub, a brake- drum and a circular wooden disk, 2 in. thick and of the same diameter as the brake-drum, all securely bolted together as shown in the picture.—E. A. MESSLER. Special Tool for Wing-Nuts and Petcocks HIS tool for use in the garage while adjusting and oiling the car can be made of a 2-ft. length of gaspipe bent at one end and slotted with a saw at both ends, as is shown in the attached sketch. This tool obviates the practice of reach- ing or crawling under the car to turn up This tool will be found helpful for turning wing-nuts and petc winged nuts provided for adjusting brake- bands or turning off stopcocks for the gas- oline line or crankcase of the motor or the drain under the radiator or pump. The turning tool is also of advantage in turning up grease-cups of the type with a winged cup for the grease. This tool is readily made up in a few minutes and its use avoids soiled cuffs, coat sleeves, and clothing. a pa Qa oenrp Moanthi,, |

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December, 1921 Shop Tire-Rack for Tubes and Casings A RACK to hold tubes in the tire repair shop is made as shown in the illustra- tion from sections of light gaspipe and connectors. This rack, compared with racks constructed of wood, is the same - price, but is far more convenient for placing FLANGES SECURED TO CEILING ELBOW CROSS-COUPLINGS This hanging rack offers many ad- vantages in the repair-shop in which space is limited a tire or tube and in locating the desired tire or tube when called for. The rack is suspended by means of flanges from the ceiling and elbows and cross couplings are used to screw the several sections of gaspipe together. This rack is hung about 6 ft. above the floor and consequently does not interfere overhead. It will hold a large number of tires and is practically indestructible. Auxiliary Wind-Shield for the Automobile (y= form of auxiliary wind-shield which will protect the occupants of an auto- mobile from rain and wind is made as shown in the illustration. This shield consists of a sheet of celluloid in a brass frame screwed jointly to the edge of the body adjacent to the wind-shield and to the wind-shield frame. One of these shields is used at the side of the car and the side curtains are altered by extending the edges so as to fasten to the brass frames. With these a clearer vision 83 is afforded the driver when the side cur- tains are in place. The transparent cellu- loid will not break and shatter as would glass, and when dulled it is renewable by separating the screwed brass strips. These shields are about 12 in. wide and made to correspond in height with the. wind-shield. The polished brass enhances the appear- ance of the car, apart from serving as a frame for the celluloid. The freedom from the usual dust and dirt obviates the use of glass or goggles. OUTSIDE INSIDE FASTEN INDSHIELD FRAME Vie“ FRAME r CELLULOID SECTIONAL FASTEN 10 A DETAIL. BODY ===. Riding in an automobile is made much more pleasant by an auxiliary shield against rain or snow Keep Your Home Shipshape © “Interesting things to do around the house i | $3 to save time, temper, and money - — Fire-Extinguishers for Use in the Home Ne means of putting out fire should be kept in every room. The following — formula will provide, for a trifling cost, material for twelve or more hand-grenades that will instantly put out fire. Get 5 lbs. common salt and 2) Ibs. salammoniac. Dissolve in 14 gal. water. Bottle this up in the thinnest bottles you can find, cork very tightly, and place them where every one will be able to find them quickly, but not in too hot a place. Should fire break out, knock the neck of the bottle off and sprinkle the contents over the fire, or throw the whole bottle into the fire against something hard with sufficient force to break it, and the fire will be extinguished.—E. A. MCCANN. Softening Sponges without Injuring Them yo grades of sponges, sold under the name of “baby-sponges” or “surgical sponges,” are invariably freed from grit and bleached with permanganate of potassium and sulphurous acid before they are placed in the market. It has been found that this ° bleaching process greatly diminishes the resiliency of the sponge fibers, making them soggy and difficult to clean. It is, therefore, obvious that the unbleach- ed sponges are preferable and more endur- ing, but they must be freed from the gritty particles which they contain before they can be used on the soft skin of the baby. These particles, which consist principally of carbonate of lime, may be removed without injuring the elasticity of the sponge by immersing it for two or three hours in water containing about five per cent of hydrochloric acid. After the sponge has been removed from this solu- tion it should be thoroughly washed in several changes of running water to elimi- nate every trace of the acid. Simple First Aid for the Alarm-Clock HEN the old alarm-clock lies down on the job and insists upon taking a rest in spite of your shaking and twirling, the trouble is generally that the cold has gummed the oil and put the brakes on some of the more delicately adjusted mov- ing parts. The cure is easy. Put the clock on the stove or on the steam radiator. Let it heat through thoroughly—of course not enough to melt the solder in the case or scorch the face—and the gummed oil will soften and run out of the bearings, leaving just enough to keep everything in the old stand-by working smoothly.—F. M. WESTON, JR. How to Make a Cracked _ Bottle Watertight pe ontngglong asked we have a cracked cut- glass or other bottle of good quality which we should like to continue using. To mend it and make it watertight, heat the bottle, cork it tightly, then paint the out- side of the crack with sodium silicate or waterglass. . As the bottle gets cold the solution will be drawn into the crack and will make a fine, tight joint. Putty Substitutes for Use in the House LAZIER’S putty is made from whiten- ing and linseed oil. A good substitute may be made of flour and oil mixed to the proper consistency. If you have no linseed oil, some varnish or paint will do. In fact, paint is better, if of the right color. A substitute that is better than putty when large holes or cracks have to be filled is paper well macerated in water and mixed with some flour and boiled. This, when dry, will be found to set almost as hard as iron. Plugging Up the Nicks in Old Furniture O fill up the nick in that mahogany table, prepare a mixture of 8 parts beeswax, 2 parts yellow ochre, 2 parts whiting and 2 parts Indian red. For more serious cracks, a mixture of shellac, beeswax, and resin in various colors may be bought, or the handy man may compound the mixture by melting in a tin or iron pot a cupful of common shellac, a spoonful of powdered resin and a piece of beeswax the size of half a walnut. For golden oak, add a teaspoonful of yellow ochre; for mahogany, the same amount of venetian red; for walnut, the same amount of brown umber. After the substances have been thor- oughly melted and mixed, the liquid should be poured on a clean surface to cool until it may be handled. While it is still quite warm, roll it into a stick between the hands. Apply to the cracks with a hot (but only black hot, not red hot) chisel. hime +3) hi ew ide | oy t Wa tect tat BOA seit 2a ns soe > tn Cn ae = St hi SOS Aa at FSi ae TITER NBN IE a atom tbimcicbn ~~ > PIE SIS:

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eater ee tat a Se eseEsIr Ls oo tages saci. wit a Pe ee eae ee os rie ae meen Soe hy ate y a bag i ik + ; Popular Science Monthly Simple Radio Receiver for Everybody N these times, when the Bureau of | Markets is broadcasting daily reports of market conditions from a chain of stations all over our country, the naval stations are sending out weather and navi- gation reports, some commercial companies are ‘operating radiophone stations, and thousands of amateurs are using both the radiophone and the radiograph, it be- hooves a good many of us to build receiv- ing-sets, get into the game, and receive some of this valuable and interesting free information. A few dollars carefully spent will build a radio set that will bring the news of the world to our homes. It is pos- sible that the market reports can be used in our business and the radiophone con- certs that can -be picked up nearly any night may take the place of our phonograph and have the added attraction that the music, though canned, is being transmitted through space from afar. It is interesting to listen to the small amateur station in your own home town talk to another pos- sibly a thousand miles distant. This instructive hobby has proved an excellent diversion to many a great engineer and. business man all over the country. A simple receiver, having a wave-length range of from 175 to 750 meters and em- TELEPHONE RECEIVERS 20,000 OHMS IMPEDANCE AT 1000 CYCLES A SEC. OR 2000 OHMS a FLAT ji CRYSTAL DETECTOR SHARP |-2 _ STOPPING CONDENSER 200 MICRQ MICROFARADS FIG.1 (.002 MED) “F GROUND How the apparatus is connected for the reception of wireless messages ploying a crystal detector, will be described in this article. A novel means of connect- ing the crystal detector with the circuit so that extremely sharp tuning is possible, will also be described. Before we can build a receiving set of any kind for a given wave-length range, it is necessary for us to know what sort of antenna we are to use, the kind and sizes of condensers that are available, etc. For the ordinary amateur the receiving antenna should be capable of being used for transmitting as well. For this reason we have chosen a T-type antenna 35 ft. high and about 80 ft. long as the ideal. Of course, the receiver will operate equally satisfactorily on a larger or smaller an- tenna, but if the antenna is too large, it will be impossible to receive the shorter wave lengths, and if it is too small, the reverse will be true. Such an antenna as the one described will have a natural wave length of about 150 meters and a static capacity of about 400 micromicrofarads. By Arnold Holmes O you know the joy of receiving radio messages and radio concerts? Long wintry nights are ahead of us. Have you thought of sitting in your warm, comfortable recom and bringing the news of the world to your ears? Nothing is more fascinating. You can do it. Only a few dollars and a few simple tools found in every tool chest are needed. Start now. WIRE TO BE WOUND ON TUBE sy “> 4 ONE TURN TAPE CUT FIG.3 ENDOF WIRE A few turns of tape about the tube will prevent windings from slipping The end of the wire should be an- chored in the tube as in Fig. 3 before the winding is started Since the receiver is only to cover the limited range of wave lengths between 175 and 700 meters, it is not desirable to use a condenser larger than 750 micromicro- farads capacity. A minimum capacity of not higher than 35 micromicrofarads (.000035 mfds.) should be obtainable in condensers of this size. With these values of minimum and maximum capacity and the coils suggested, the desired wave-length range can be obtained. It is then obvious that greater wave-length ranges can be obtained by using condensers with higher maximum or lower minimum capacities. The first table on page 85 lists a number of BRASS CuP CRYSTAL SET IN WOODS META MANDOLIN STRING WIRE(SILVER- PLATED STEEL) SWIVEL ' — RETAINING *>- SPRING a The details of the crystal detector used in connection with this outfit commercial condensers and their minimum and maximum capacities. Figure 1 is a schematic diagram of the receiver circuit. The wave length of the secondary circuit is determined by the inductance coil L, and the adjustment of the condenser C,. The wave length of the antenna circuit is determined by the an- tenna, the inductance of the coil L,, and the adjustment of the condenser C,. The two circuits are coupled electromagnetic- ally through coils L, and Lz. The coupling is variable by rotating the coil L, within L,. The tuning of the circuit is made sharp or flat in part, by adjusting the coupling handle so that the coils are mutually per- pendicular or parallel to one another. The crystal detector is generally con- nected across the receiving condenser so that all of the voltage of the received signal acts on the detector. Physicists who have studied the crystal detector, tell us that it has a very high resistance for weak signals and a low resistance for loud signals. Thus the condenser C, is shunted by a very high resistance when weak signals or no signals at all are impressed on it and a relatively low resistance when strong signals are yourske Sop} — $3 +t oA\ |PRIMARY COND. SECONDARY COND ; > \ (@\ \t oy © / PRILIND. * © jhol TELEPHONE ee ec |.” ACT” BINDING= } peene-->, COUPLING e “3.200 POSTS 7 i i - a —— — — be |. arcs OF Tf CONDENSER : . 2 ze 68 ugg” ; nas Swe " “ht £ ro a3 (| FIG.S How the apparatus is finally mounted on the panel impressed on it. Shunting the condenser C, by a resistance has the sante effect as adding resistance in series with the induc- tance and the condenser C,. The lower the resistance, the greater the resistance thus added. Engineers have found that the sharpest tuning results when the resistance of the circuit made up of L, and C, is low- est. From this we see that the crystal detector connected across the condenser gives flattest or broadest tuning for the strong signal. If, instead of connecting the detector across the condenser C, or ‘the coil L,, it is connected across only a portion of the coil L,, it will have less effect on introducing resistance in the circuit, and the tuning will be sharpened materially. In fact, with this arrangement, it is pos- sible to obtain as good selectivity as can be had with the vacuum tube receiver. This method of connecting the detector to the receiving circuit is, in effect, loose coup- ling the detector to the secondary circuit. The coils can be wound on cardboard, or rubber tubing. If the set is to be very well made, it is desirable to turn a thread on the

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December, 1921 tubing having the same pitch as that of the’ wire when wound close together. In wind- ing coils on tubing of smooth surface material, the following kink will be found very useful: wind a single turn of friction tape around the tube longitudinally in three places (Fig. 2). This will hold the wire firmly and prevent it from slipping during and after winding. After the winding has been completed, the tape can be cut close to the winding with the aid of a penknife. The wire_can be fastened at each end of the winding by drilling three holes in the tube in line with the wire and winding it i in and out as shown in Fig. 3. The dimensions of the coils and the winding data, the capacities of the various condensers, etc., are given below: For the crystal detector, any of the standard makes of stands may be used, and galena, radiocite, zincite, chalcopyrite, etc., used as the crystal. A satisfactory crystal-detector stand is shown in Fig. 4. The crystal is held in a small metal cup by Wood’s metal (a low melting alloy). The cup may be turned in any position by means of the knob and held in position by the set screw, The cat-whisker is adjust- able by turning the handle or sliding the rod through the support. The brass spring is fastened to the support and presses on the cat-whisker rod so that it will stay put in any position. The rod is also cap- able of swinging on the swivel, which is made so that it will stay in any set position by means of the spring washer. In oper- ating a crystal detector it is beneficial to occasionally wash the crystal with a little carbon bisulphide. Usually panel mounting is the most satis- factory, because the panel can then be mounted in any convenient place. A conveniently arranged panel is shown in Fig. 5. This arrangement allows the equipment (allowing for a 5-in. diameter condenser) to be mounted on a panel 10 in. by 12 in. One of the possible arrangements of the coil mountings and details of the adjustable coupling feature are given in Fig. 5 for the convenience of the experimenter. With a set of this sort it will be possible to over- hear spark stations, buzzer-modulated con- tinuous-wave stations, and radiophone stations within the range of wave lengths specified. 85 COIL DIMENSIONS, ETC. Condenser Min. capac. Max. capac. Carfacity Ci 35 M.mfds. 750 M.mfds. ; ; C3 (stopping condenser) 200 M.mfds. Tars taken nie off at ] Tube Winding Total turns, Coil -dia. length turns Nos. Ll, 3 in. 2% in. 105 20,40,60 Lz 2% in. 1% in. 60 15,30,45 CONDENSER TABLE List of standard commer cial condensers and their approximate capacily range How to Make a Pair of Delicate T? construct with ordinary tools and from ordinary material a pair of chem- ical balances that will weigh the ink on this sheet of paper is not at all hard or impos- sible. So delicate a pair can be constructed easily from 4 ft. of No. 10 iron wire, 4 ft. of No. 16 iron wire, 4 phonograph needles, some small strips of 1/16-in. brass, and 3 small blocks of wood. The tools necessary are pliers, hammer, small center-punch, vise, and soldering outfit. Having pro- cured these implements and supplies, pro- ceed as follows: From the No. 10 wire carefully bend the form of the frame. The following dimen- sions are suggested: height 6 in., width of top 2 in., width of bottom 2in. This frame should be bent by the aid of a vise and hammer. The two ends of the wire should be butted together and soldered under one of the curved ends of the bracing strips across the bottom. When the bending is completed, the little stiffeners made from 1/16-in. brass 5-16 in. wide, should be bent and soldered into’ place. Two.small holes should be bored in each of the bottom straps in order that the frame may be fastened to the baseboard. On the front side of the lowest cross strip a graduated scale should be marked. The most satisfactory way of marking is by means of engraving the scale in the brass strip itself. However, the scale may be made on paper and pasted to the strip. Next in order are the balancing points, which take the place of the knives of the ordinary chemical balances. This is one of the most exacting details of the entire construction. These points, which are phonograph needles, are fitted in the top of the frame as shown in the detail illustra- tion, and are held exactly vertical by a bit of solder. Now, screw the frame to a base- board planed flat and sandpapered and supported by two stationary feet and one adjusting screw as shown. The balancing arm is made from another piece of the No. 10 iron wire. It balances on the two needle-points and carries the weighing-trays. It is 10 in. long. The tray-balancing points are spaced 2)% in. on each side of its center. On the under side of the arm, exactly in By Bert Rodson BALANCE ARM FRAME ross This shows the appearance of the balances when completed in accord- ance with the directions given the center, is soldered a steel plate, 1/16 by Ys by 2 in. The center-punch marks on the under side of this plate fit over the main balancing-points. The making of these two center-punch marks is the most delicate operation of the entire construc- tion. The center of the punch marks must coincide within 1/1000 in. of the needle- points. A good method of procedure for the making of these indentations follows: Procure a center-punch that has been ground to a very fine point and the point polished with emery-dust. Soften the piece of steel. (Brass may be used, but if THREAD —— PHONOGRAPH NEEDLE ~ =e BALANCE PLATE NEEDLE DETAIL OF FRAME eSS=s3 TOP OF FRAME POINTER DETAIL The balancing arm is shown here in top view, also details of the most delicate parts of the structure Approximate Approximate Manufacturer Minimum aximum Cap. M.mfds. Cap. M.mfds. De Forrest C. V. 1503 30 1600 Gen. Radio 182 A. 20 670 182 E 25 940 50 1500 60 3000 Murdock 68 20 500 366 25 870 Seibt 5500 20 640 51000 . 25 1100 5200 45 2300 West. Elec. Co 46 A. 30 750 47 A. 25 225 Chelsea 1 20 530 2 35 1050 so, the balances will not be as delicate.) Cover the side to be punched with chalk. Draw this chalked side across the needle- points carefully, in order not to blunt them or turn the points; then very carefully punch exactly on the fine lines left in the chalk and in the center of the strip. The center-punch marks in the strip and the balancing-points should then - coincide exactly. Now reharden the strip and solder it to the center, of the top cross piece. Next, insert the phon ograph needles that are to carry the trays. Thread 1% in. cf each end of the beam and screw a small weight on each. These weights will make it possible to bring the scales into perfect balance. Attach a point (made from two parallel No. 16 wires) as shown in the picture. At the end of this pointer insert a piece of very thin flat steel or brass. The edge of this strip next to the scale should be ground to a knife edge so that exdéct reading on the scale may be taken. The weighing-trays may be made from metal, but they may be turned from the lid of a cigar-box more easily. They are hung on No. 16 wire brackets carefully bent as shown. On the inside of the topmost _curve of each bracket is soldered a small piece of steel with a center-punch mark. The tray brackets then hang-from the balancing points. If the brackets have been carefully made, the trays will hang exactly level. These balances will be found so sensitive that they should be operated in a room where no air is stirring. If the needles are perfectly sharp and accurately fit in the center-punch marks, and if the steel in- serts in the top of the tray brackets are tempered until they are very hard, you will find no dfficulty in weighing the amount of lead that rubs off of an ordinary lead- pencil in writing a half-page letter, or the amount of carbon dioxide taken out of the air overnight by a plant. A good way to obtain small weights for your balances follows: Procure a thin sheet of aluminum and have it weighed ex- actly by a scientist or a druggist. If it weighs 100 grains, cut it into one hundred equal pieces and you will have 1-grain weights. Cut a few of these in half and a few in quarters. Cut, do not saw or file. Sia LN a I Aad a aE TT PES ee a ee j j | i Fie aaah ERS aria eagle ae at eng: SP aa ee el _— o

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ii it iid he sae ee if? i 4% His ace 8 ia is } a Ba | a] ey nas if : 2m en 4 — - shag er ark nani enc ae nT ea Serre ores fener Se . z pi Sag ASS : ~ oc epenomncegh tue sinewave Popular Science Monthly Useful and Attractive Ornaments from Carved Clay EAUTIFUL as well as useful articles can be made of carved clay. The clay must be soft, like talcum, and under no conditions should it be gritty. A gritty clay is difficult to carve. The purer the clay the easier it is to work. It should have the least amount of foreign material in it. Only those pieces that are free from sand and pebbles are to be used; all other pieces must be rejected. But most important is its color. This may range from pure white to yellow, brown, lavender, and red, together with all intermediate shades. The variously tinted clays are more beautiful than the white, and the mixture of two or more colored clays is still better. If the clay is so dry that it is difficult to mold, water should be added until it be- comes very soft. When soft, two or more colors of clay may be worked together, which, when dry, will give the effect of marble. When this has been accomplished so that no air spaces remain, it is molded by pressing it into shape. The shape de- sired will, of course, depend largely upon the quantity of clay on hand and the de- sired object to be made. But it is always best to make blocks that are somewhat larger than the intended product. If a smoking-set is made, then the largest block, which is to hold the tobacco, can be hollowed out at once. This is best accom- plished with a tin can. The other, and smaller blocks, are left as they are after they have been formed. After the blocks have been formed, they Here is shown the method of cutting out the well of the clay jar with a tin can of proper size By E. Bade In carving the designs in the clay, you may give free play to your im- agination and artistic gifts are dried. This is best done in some warm room or attic. Care must be taken that they are left undisturbed for at least 6 or 8 weeks. Never place them in a stove, or otherwise bake them. This only causes them to crack. The slower the drying process, the better will the clay dry. When the blocks have become thor- oughly dry, they are shaved down with a knife. When they have the desired dimen- sions and shape, the interior must be carved out, if this has not been done with a tin can. Here great care must be taken that the knife does not slip or that the corners are not chipped off. If octagonal jars or other containers are to be made, then the blocks are first squared, and after measuring the exact size of the corners to be cut off and drawing them with a pencil on the clay, they are slowly shaved down to the re- quired shape. The cavities in the blocks of clay can easily be made with a brace and bit or simply by turning the point of a knife on the block; but care must be taken that no pressure is exerted. After a small hole has been made, it can be enlarged with a pocket- knife until it reaches the desired size. Never make the walls too thin; it is best to have them at least 14 in. thick on small objects, and 1% to 34 in. on larger ones. Now the most difficult and at the same time the most interesting work remains to be accomplished. That is carving. Since the clay, when dry, is very soft, it is a com- paratively simple matter to carve. Formal designs are the most difficult to make. Here the straight lines must lie in certain positions, and if slightly on one or the other side, or if one end is slightly thicker than the other, the whole appearance of the object will suffer. Although at the first glance they seem to be more difficult, the simplest designs of all are leaves, branches, and tendrils; if one line does not lie in the position it is supposed to occupy, no harm is done. The selected designs are first drawn upon the surface of the clay, and then the clay is removed on all its sides in small pieces, pre- ferably as dust. The design itself should stand out in relief to obtain the very best effects. When the object has been completed to the satisfaction of the worker, it must be covered with some kind of a varnish; other- wise the clay would: come off at every touch. For this purpcse celluloid dis- solved in acetone is ideal, especially if the solution is made very thin. The acetone forces the celluloid into the clay before it dries, and when dry the surface will be hard. It is best to give each object two coats, the second after the first is absolutely dry and no more fumes can be detected. Great care must be taken that the acetone is not brought near a flame, since it is very inflammable. A smoking-set like the one above will be appreciated as a Christmas present by any smoker Moving Shadow-Pictures on the Screen Are Amusing PAWAIAN dancers, dancing animals, etc., shown in motion as shadow- graphs on a screen will form an attractive entertainment for children’s Christmas parties. The figures of the dancers or romping animals are drawn on heavy manila wrapping-paper and carefully cut out. The illustrations below give a number of suggestions for such figures and show how they may be cut out singly, in pairs, or in triplicate. a z Draw one figure, fold the paper as indicated, and after cutting along the outlines you will have three figures The spectators at the entertainment are all seated in the parlor. Over the door to the next room a large sheet is stretched. The lights in the parlor are turned down during the show. The figures are sus- pended by thin -threads pinned to the sheet singly or in groups, and the enter- Moving the two candles in different directions with the music makes the figures seem to dance tainer, holding in each hand a lighted candle, stands behind the curtain and moves the lights in rhythm with the music of the piano, thus producing the illusion of the figures dancing to the music. The illusion may be aided by giving a jerky motion to the sheet. By arranging a program, it would be a simple matter to elaborate upon these dancers and to tell an interesting story with boldly defined cut-outs—in short, to produce a shadowgraph marionette show that would amuse the grown-ups of the party as much as the youngsters. Dancing lions, elephants, and other animals add to the comical effect of this shadowgraph entertainment

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December, 1921 i \| ull Mi | Ml PIKES): MEN WANTED! kx ' Young men mechanically in- clined, get into the automo- bile business now and make real money. And remember you are never too old. Henry Ford was 40 when he started the Ford Go. 9 j } i WEENEY trained men are in demand Pi Pay Your Ra Iway off algo at good yess $50 ha and i ,from garages, tire shops, welding con- F. ar e to Kansas City! ae auto ti ar el etc. Inthe last six ee UES farm products have all gone down, but the autos still | i kept running and no trained mechanic had to hunt a job. My Big Announcement this season— 5p wages are paid, but SWEENEY TRAINED You can come to the world’s largest and best trade MEN ARE WANTED. Here's the proof: aon at no —_ ger —_ if it — located in —_ al d ; ome town, for I am rebating fares from any point in the U. S. to the Sweeney School. No advance in tuition, H un r e Ss Oo = ee: * — —- — ba = i F M V4 where you live, this brings the Sweeney Million Dollar School to your door. Op en ngs 4 Or en Thousands upon thousands of young — about “MECHANICAL TRAINING. abou . A and they answered my advertisements, Business 1 got my Big Free Catalog, came here, Is Better! learned the business, and today, in all parts of the country ARE MAKING South Dakota wires: “Will pay most any price for a good man. Send him right away.” Neck City, Mo., says: “Put us in touch with a first class Young man, be independent. repair man. Excellent opening.” Indi- GOOD. I ° f Strike out for yourself. Hold ana says: ‘““Want one more Sweeney - can give you hundreds o up your head. On the sky- man for my new garage. Steady work etters from these men that relate line of Opportunity see the at good prices.’”’ Kansas appeals: “Send es and hopes so like your Sweeney School. We are me a man who understands Ford Car aS at you will be amazed. TRAINERS OF MEN, ARCHI- § from AtoZ. Will pay top wages.” Mis- These men TOOK THE FIRST § TEcTs OF SUCCESS. Ihave § sissippi telegraphs: “Want a post grad- STEP. They wrote for my catalog, i : : - and date their present success from that nl 2 _— "on uate mechanic. Will pay all he is worth. A ‘ y Wire at my expense.” Florida calls: moment. They will tell you: OTHERS SUCCESSFUL. Take “Want head mechanic, Will pay $50 ss . " your first step toward success a week. t me hear by return mail.” ee bo ae. tera Psy oneaeen by writing me today. Over Thousands of Sweeney graduates now owning their Learn it right. LEARN IT AT 46,000 successful graduates. own business in various parts of the coun- SWEENEY’S.”’ try naturally favor the Sweeney trained men. Sweeney loyalty is wonderful. Our daily mail is conclusive proof that the trained man with a Sweeney di- ploma can se- cure jobs like these at $50.00 a week and more. » Get This Free Book MON NOdNOD SIHL IIWW But These Men Never Had the Opportunity You Have Right Now The railroad fare to Kansas City is a big item. Lots had to pinch and scrape to make it. But | will now pay your fare. But you must COME NOW. I don’t know how long I will keep this offer good. Because [WONT ACCEPT MORE MEN than I can properly handle and give the attention to them that the Sweeney System demands. _ I’ve got over a quarter million dollars worth of equipment in the largest trade school in the world, covering 12 acres of floor space—but there’s a limit to all things. And when that limit is reached— I’ll withdraw this Free Fare Offer. F; I will gladly send my 72-page illustrated catal ree FREE. Also a free copy of the Sweeney Schoo News, a most interesting monthly school paper —emes §=published here. You will enjoy them. Read the worth-while stories of men like yourself who came to Sweeney’s and found success. Read how Frank Powell and Harry Wilson built up & $20,000 business in about two years after graduating. Read how Elbert A. Pence built up a $25,000 yearly garage business at Clear- mont, Mo. These stories and others are told by the Sweeney stu- dents. Also I want you to learn how my students enjoy themselves after work in the swimming pool, the club and reading rooms, etc. EMORY J. SWEENEY, President. Send Coupon Right Now! f"SLEARN A TRADE YU For me Mail This Coupon Toda EMORY J. SWEENEY, President Dept. 947 Sweeney Bidg., Kansas City, Mo. Send me free without any obligation your 72-page catal in the Auto and Tractor Business. ‘ ‘ @fre a ‘ ar = ore s celta | owve EMEY BLDG. KANSAS CIT Y,Fv0y RE A SLE 5 Me Ieee MR TS iil | Free Catalog jogue and your Sweeney Schoo! News. Tell me-of the opportunities 87 En eee ae ee —— ee 7 ; + 5 i ; | ELLE OTS

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Se 5 Fe Bs ata ee oo ere erenny Ke i oF = SS “WALLY” REID Star of the Movies, Plays a True-T one Saxophone While not classed as a musical star, Wallace Reid's Saxophone affords him much pleasure in home en- tertainment. His decision to purchase a Buescher was made after knowing it to be the Choice of Professionals such as Tom. Brown of the Six Brown Brothers; Clyde Doerr of the noted Art Hickman’s Orches- tra and Columbia Record Maker; Donald Clark, ex- pert Saxophonist with the celebrated Paul White- man’s Orchestra; J. Gurewich, Saxophone Soloist with Sousa’s Band, and many others. More Buescher Saxophones are used than the combined product of all other manufacturers, because they are Easiest to Play You can learn the scale in an hour’s practice and play popular music in a few weeks. Practice is a pleasure because you learn so quickly. You can take your place in a band within 90 days, if you so desire. Unrivalled for home entertainment, church, lodge or school. In big demand for orchestra dance music. A Saxophone will enable you to take an important part in the musical development of your community. It increases your popularity and your opportunities, as well as your pleasure. Saxophone Book Free “The Origin of the Saxophone”’ is an interesting booklet. It illustrates the beginner's first lesson. It tells what each Saxophone is best adapted for; when to use singly, in quartettes, sextettes, octettes, or in regular band or full Saxophone Band. Tells how to transpose for ‘cello parts in orchestra. It illustrates and fully describes the virtues of each model of the Saxophone Family. Ask for your copy. Thousands of the most successful professionals use Buescher Cornets, Trumpets, Trombones and other Band and Orchestral Instruments. Free Trial-Easy Payments You can order any Buescher instrument without paying one cent in advance, and try it six days in your own home, without obligation.’ If perfectly satisfied, pay for it on easy payments to suit your convenience. ention the instrument interested in and a-complete catalog will be mailed free.: (30) BUESCHER BAND INSTRUMENT CO. Makers of Everything in Band and Orchestra Instruments 3130 Buescher Block Elkhart, Indiana tl a RN naam a aammgmnna 2s Popular Science Monthly THE HOME WORKSHOP Build Your Own Sather All aboard for a delightful trip through the crisp winter air with Air-Driven Sled By P. P. Avery — 5 “es ot metre Bane { odin this propeller-driven sled G OOD looking as is this homemade ice- flyer, it is not expensive, as it can be made from used parts that a mechanic always has lying around his workshop. Its novelty and speed will make a strong appeal to all lovers of outdoor sport. And now for the construction. First, look around for some spruce wood and from it build three 2-in. runners. Be sure that the spruce is well seasoned and that it has no knots in it. As soon as you have com- pleted the runners, apply two or three coats of the best spar’ varnish. For the motive power a good second- hand Ford power plant could be used. At the end of the elongated crankshaft is placed the 6-ft. propeller. The old Ford transmission is dismembered, all useless parts are removed, and sheet-iron plate is placed over the universal-joint housing. The engine is set on an angle-iron foun- dation as shown. All unnecessary parts are discarded, such as the fan, for instance, as the radiator receives plenty of air. The exhaust pipe is elongated and carried to the back of the sled, as shown. The frame of the air-sled is of 6 by 10 in. spruce reenforced by 34-in. bolts and corner clips all around. The rear sled is for steering and braking. It is pivoted on a vertical axis that has a 1\%-in. pipe handle. A strong spiral spring is placed around this steering-post, be- tween the rear end of the platform and the steering-sled. This allows for unevenness 21-0 GASOLINE 5 GAL. GAS AND) 4X8" SPARK yz BOLTS TILLER 3'x6" vi PLAN VIEW SHEET | Ve X8 TONGUE AND GROOVE FLOORING : oO" > | © 7° Front elevation of the air-driven ice-sled, showing the framework supporting the engine in the ice surface. The side bands are of 1\4-in. pine and the flooring is nailed or screwed to its base. One-inch quarter- round strips are nailed along the edges. Battery plus magneto ignition is preferable to any other. When finally you have completed the sled’s construction, the body should be given two coats of the best spar varnish and two coats of American white lead on all other parts. A gray and black striping for the floor and the runners will give your new conveyance a professional finish, FAN ELIMINATED Side elevation and top view of the sled are here shown. The dimensions given are merely tentative and may be changed to suit conditions ~ Dec

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December, 1921 _MONDAY (TUESDAY 89 “WEDNESDAY with Electric Lifting Magnets Boys! You Can Have a New Toy Every Day HERE is simply no end to the fun you can have with Meccano—fun building the models, fun working them, fun taking them to pieces again and building something else. Think of it—you can make hundreds of models of things that work, each one a fascinating, real, worth-while toy—all made vt MMECCANO Any boy can build Cranes, Bridges, Airplanes, and all kinds of machines, and then make them work like real machinery with the Meccano electric motor. The big Book of Instructions in each outfit makes everything clear even to the youngest boy. Send for This New Meccano Book It describes Meccano and tells inter- esting things about model building. Every page a pleasure. Sent free if you send us names and addresses of yourself and three chums. Put No. 36 after your own name for reference. TO BOYS MECCANO COMPANY INCORPORATED Div. K, 71 W. 23rd St., New York City a Cal - SS —— Seer a awe rT. ea Pa Sener Ra ee xt “K : er f: nee aie VX: Tt Tian, *8Xd ayy, “8305,,, 00 88 ay SF erry it 4 : f a 3 j i He } 7 i i] ® i] eae 4 4 } { 4 2 3 j i fi i i PRIZE CONTEST Ask your dealer for Free Entry Blanks or Write Us Gantry Crane

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Popular Science M onthly About the Care of Dry Cells in the Country Py cells, whether for one purpose or another, are used in almost every country place. They make the spark that lights your gas and runs your engine, they ring your doorbell, operate the burglar alarm, and perform other duties too numerous to mention. Dry cells should be kept dry and clean ‘and slightly warm in order to give satis- factory service. When they are pur- chased, it is well to give the zine cases a coat of shellac or varnish so as to make them as damp-proof as possible and to prevent corrosion from the outside. The paper containers should be replaced, to further protect the batteries. Cells that come in units of three or more are sealed in a pitchy compound to elimi- nate moisture, loose connections, and short circuits. If it is desirable to make your own “units,” make light boxes large enough to hold the cells and line them with heavy paper. Place % in. of dry sawdust on the bottom and put in the batteries. With a wooden stick pack in all the saw- dust you can to the top of the cells and connect them with No. 14 insulated wire, making sure that the wire is scraped clean and that the nuts are tight. Use the pliers for this. ~ Then finish filling the box, fold over the paper, and attach the wire leads from the batteries to two binding- posts placed near the top on one side of the box. The cover may’ now be fastened. A piece of “strawboard’’ placed beneath and above the cells would act By A. J. Christopher as a shock-absorber and would provide an air space, but it is not necessary. The box may be painted. The batteries 12 AMPS 13 12 10 1s FIG. 3. Several methods of connecting dry cells that will prolong their life are shown here will last much longer if protected in this manner. For the gas-lighting coil, four to six cells in series are usually used, and for engine ignition from three to ten. In this work they function properly only until one or more drops below five or six amperes. These run-down cells then cause resistance in the circuit and the coil, not receiving the proper amount of current, cannot produce a fat spark. When the dry cells that operate a coil seem to be weak and, upon testing one or two, are found to be below normal, connect the two weakest cells as shown. Unless they are entirely exhausted they will give a little more service. A number of partly run-down cells may be connected in multiple series and will last a while longer. On farms where gas is employed for lighting, each building or group of buildings has its batteries and coil. About once a year these batteries are replaced. Those removed should be tested. All showing four amperes or better should be kept and connected in multiple series. Always arrange them so that each cell or multiple of cells placed in series test around ten amperes. When connected in this manner, batteries that would other- wise be discarded will give service for from two to six months on a gas-lighting circuit. An ammeter test, if taken from the leads of the series-connected batteries, is un- reliable, as it does not show a weak cell if one should be run down. Each cell, there- fore must be tested individually. Oil-Filter for the fe PetCiENT and handy is this filter for oil. It can be made in the farm work- shop from an ordinary wooden barrel, as shown in the accompanying illustration. The head is removed from a barrel and a cover is made to take its place. A circular hole 6 in. in diameter is made in the center of this cover. A 5-gal. round, conical top oilcan, in an inverted position, which serves to feed the oil to the filter, is placed in this hole. The bottom of this can is cut out smoothly and is perforated with small holes made by the point of a small nail. This old can bottom is then dropped into the can and rests on the flare of the conical top. Into the mouth of the can is soldered a ————— COVER FOR OILCAN le” CDIRTY OIL TO BE FILTERED — 2—NEW CLEAN WASTE , SLAYERS OF BURLAP ON q PERFORATED PLATE OVER FOR BARREL -——~FILTERED OIL ON SURFACE OF WATER re freee BARREL OIL RISING THROUGH PURE CLEAN WATER = ——= PIPE CONNECTING Pee “te CAN WITH TEE AND 5 een teelee LM SHORT LENGTHS OF PIPE ri fier A HAVING HOLES DRILLED oes uo ON UPPER SURFACE Every farmer who uses machinery may save money by constructing and using an “Dil-filter like this Farm or Shop short piece of small-sized iron piping to other tubing that extends near to the bottom of the barrel. To the threaded end of the pipe a T is screwed and a short piece of the same size piping is threaded into each side of the T to extend hori- zontally almost to the walls of the barrel. In the upper sides of these short pieces of piping are cut several small holes for the escape of the oil. The ends of these short pieces are plugged up with cork stoppers. On the perforated plate in the oilcan several layers of felt or burlapping are placed. On top of the burlapping is laid a bunch of new, clean waste, as shown in the illustration. This fills the can about half full and the remaining space receives the oil. The oil is then poured in on the waste in the top of the inverted can. The barrel is filled two thirds full of pure, clean water and is provided with a bibcock that is 1 in. above the level of the water in the wall of the barrel. A cover is made for the top of the oilcan. It is obvious that the oil seeps down through the waste, through the burlapping and the perforated plate by force of gravity. Thence it descends through the perpen- dicular pipe out through the short, hori- zontal pieces of piping attached to the T union and emerges, a drop at the time, from the small holes made in their upper sides, rising to the surface of the water in the barrel, which helps to refine and clean the oil. As soon as enough oil has been filtered — to rise to a level with the bibcock in the side of the barrel, it may be drawn off as needed. The supply of waste and bur- lapping can be replenished with little diffi- culty when it has become polluted with foreign matter.—L. M. JORDAN. Shopmade Speed Wrench of Simple Construction A SIMPLE form of jointed speed wrench for a small shop is worth duplicating, being of especial advantage in getting around almost any form of interference due to pumps, wires, and pipes. This wrench is not used to start or finish the bolt turn- ing, but is for the express purpose of spin- ning them off. A heavy open-end wrench is used to start the bolt and this speed wrench is slipped on, when a quick job of removal is made. To make the wrench, use a l1- or 1%-in. length of pipe. Drive this over the bolt head and flatten up the sides to a fair fit. Use a piece of round stock and after drilling through one end, countersink from each side and round the end over as shown. Rivet this into the socket. Make the handle as shown, with a crank end and an eye to engage the eye made in the socket plug. To use, hold the handle in the left hand and turn the crank with the right. This wrench is particularly useful for removing cylinder-head bolts, especially those of a V-type eight- or twelve-cylinder motor. ra BAR STOCK FILED L AND DRILLED RANI PIECE OF DRILL-ROD Here is shown a simple form of a homemade s wrench which will be found very useful upr ani pla anc ena for for the cor sta the ZOY the str bot wo wo eit] bo ’ sta the ope per

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~~ - oN December, 1921 THE HOME WORKSHOP Christmas-Tree Candle-Holders that Always Hang Vertically OR the Christmas-tree, here is shown an easily made candle-holder that will hang upright anywhere on the tree. It can be made of wire or tin plate, with lead or babbitt weights to hold the candles Candle-holders of this type are easily made and will always hold the candles in vertical position upright. The weights can be cast in many designs, such as fish, or other animals, fruits, ete. They can be cast in plaster of Paris molds direct to the holders and may be painted with gold or aluminum enamel.—LouISsA A. CAPPEL. Build Your Woodbox Under the Stairs i bao the living-room stove is a wood- box that is large enough to hold wood for the entire day, and it is never in the way, since it occupies a space that was formerly unused under the lower part of the stairway. ; A small door in the living room wall gives convenient access to the wood. The box is filled from the foot of the stairs. This is made possible by removing A woodbox under the stairs will make the housework easier for the housewife the entire fifth step and the top or hori- zontal section of the fourth, and fastening them together securely with screws and iron strips, bracing and reenforcing the corners both inside and out. This is the lid of the woodbox. It is hinged in place. Strong wooden supports were nailed to the wall on either side for the steps to rest on when the box is closed. To prevent falls and accidents on the stairs, the lid must be kept closed except when the box is actually being filled. So the lever shown in the line drawing is to open the box when stepped upon and to permit the box lid to close automatically when the foot pressure is removed. 91 This New Way Now beautifies teeth half the world over Millions of people, half the world over, now clean teeth in a new way. Modern authorities approve it. Lead- ing dentists everywhere advise it. This is to offer a ten-day test. The results will surprise and delight you. And they may lead, for you and yours, to life-long benefits. Write for this free test. That dingy film That viscous film you feel on teeth causes most tooth troubles. It clings to teeth, gets between the teeth and stays. It dims the teeth and often leads to ruinous attacks. Film absorbs stains, making the teeth look dingy. It is the basis of tartar. It holds food substance which ferments Watch these Pepsodent does more than fight film. It brings other results now believed es- sential, in view of the average diet. It multiplies the salivary flow—Na- ture’s great teeth-protecting agent. It multiplies the starch digestant in the saliva—put there to digest starch de- pesits that cling. It multiplies the alkalinity of the saliva—Nature’s neu- tralizer of the acids which cause decay. Pepsin is also included. Pepsadent. REG.U.S. The New-Day Dentifrice A scientific film combatant, whose every application brings five desired effects. Approved by highest authorities, and now advised by leading dentists everywhere. All druggists supply the large tubes. ALN ie TRE IDE EAB LBER REI INE and forms acid. It holds the acid in eontact with the teeth to cause decay. Millions of germs breed in it. They, with tartar, are the chief cause of pyor- rhea. Also of many diseases. Old brushing methods do not end that film. So very few people have escaped some form of film attack. Now ways to combat it Dental science, after diligent research, has found two film combatants. Able authorities have proved their efficiency. Now peoples of many nations use them daily, largely by dental advice. The methods are embodied in a den- tifrice called Pepsodent. And a 10-Day Tube is being sent to every home that asks. five effects This ten-day test will 20 times repeat all the effects. And you will gain a new idea of what clean teeth must mean. Send the coupon for the 10-Day Tube. Note how clean the teeth feel after using. Mark the absence of the viscous film. See how teeth whiten as the film- coats disappear. You will always want your teeth, we think, kept that white, safe and clean. This is too important to forget. Cut out the coupon now. Ten-Day Tube Free “”° THE PEPSODENT COMPANY, Dept. 329, 1104S. Wabash Ave., Chicago, Ill. Mail 10- Day Tube of Pepsodent to i ee Only one tube to a family.

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| vt ithe if i uJ i ig H Fe 4 { i j 92 | COL OTOM Wott ets You Ought to Know VERY day in your work you get up- against new problems—sometimes it is only some old ‘‘sticker’’ coming in a new way. Just the same though it takes a lot of time to figure them out. Don’t do it. Here’s everything worked out for you. Every problem big or little that you will meet in aday’s work. Hundreds of new ideas and better ways of doing things. Hundreds of ways the other fellows are making money. Hundreds of ways you can make more out of the same work you are doing now. Cyclopedia of Carpentry and Contracting Five great big volumes bound in genuine American Morocco with 2138 pages and more than 1000 blue- prints, plans, pictures and diagrams. It is the new- est, most complete, most practical work of its kind ever published. Twenty-five well known experts prepared these great books, gathering the material from hundreds of different sources. very man in the shop and on the job should have them. The old days of hit-or-miss experience are passed. You have got to know if you want to keep in the running now. A little of your spare time and the Cyclopedia of Carpentry and Contracting will put you ‘way ahead of the rest. See our FREE trial offer and easy payment plan below. FREE EXAMINATION What You Should Know About Archi- tectural Drawing. What You Should Know About Car- pentryand Building, tracting books TODAY. You can’t afford to be with- out them and you don't take any risk atall. The coupon brings the whole set by ex- press collect for a week's free examination. Use the books a week and notify us to get them back if they don’t please you. it you like them send us only $2.80 in 7 days and $3.00 each month until $24.80 is paid. Send the coupon NOW and get the consulting membership free. This part of the offer will be withdrawn when the mem- bership is filled. Remember —sending for the books does not obligate you to buy. Cost of a Building. How to Build a Frame or a Brick Structure. How to Be a Suc- cessful Building Su- rintendent. hat You Should Know About Con- tracts and Legal Relations. How to Know Ma- terial and Select the Best. How to Write and Read Building Specifications. 1000 Better Ways of Doing Things. ow to Care for Tools. American Technical Society Dept. G-209 ” CHICAGO Popular Science M onthly THE HOME WORKSHOP New Prize Contest “How I Made Money with My Tools” AVE you ever made extra money with your tools? we want to know just how you did the trick. something, describe it. If you have, If you constructed If there is a particular job that you do, let us know what it is. , For instance, we have heard of a chap who mends furniture in his neighborhood during his spare time. Others have established small spare-time businesses with tools as their only invest- ment. Sit down now and describe your own experience for the readers of Popular Science Monthly. If you have photographs or drawings of the things you have made or the job you do, send them along. Tell your story as humanly and interestingly as possible. - $90 in Prizes Popular Science Monthly intends to make this worth your time. If you do not win one of the three big prizes it is possible that your article will be bought at space rates. Prize, $25; and Third Prize $15. First Prize will be $50; Second Conditions of the Contest (1) Contestants are not limited in the number of ideas. The contest is open to everybody. (2) If a drawing is sent in, it need not be made by a skilled draftsman. The contestant’s name and address should appear on each > sheet of drawings. must be accompanied by a descrip- tion, preferably typewritten, in which the subject is clearly explained. The MSS. must be written on one side of the paper only, and should not be more than 500 words in length. (4) Drawings and descriptions en- tered by contestants must be received by Popular Science Monthly not later than 5 p. m., on January 20, 1922. (5) The judges of the contest will be the editors of Popular Science Monthly. (6) The first prize of $50 will be awarded to the contestant who, in the opinion of the judges, has sug- gested the best idea. The second prize of $25 will be paid to the contestant who sub- mits an idea next in merit. The third prize of $15 will be paid to the contestant who submits an idea third in merit. - pentryandBuilding. | ¢ mONTHS TO PAY (7) The winners of the contest will Steet pauare Suc- | send the coupon for these (3) Drawings and photographs be announced in the earliest possible HowtoEstimatethe great Carpentry and Con- issue of Popular Science Monthly, and their articles will appear later. (8) The editors of Popular Science Monthly shall have the right to publish meritorious manuscripts that do not win a prize. The regular space rates will be paid to the con- testants who submit the manuscripts thus selected. (9) Manuscripts or drawings will be returned to contestants if stamps are enclosed. (10) Send drawings and specifi- cations to. the Editor of the Making Money with Tools Contest, Popular Science Monthly, 225 West 39th Street, New York City. —. Bench-Hook and End-Wood Planing Device a has attempted to plane pushing from you. The plane slides in the the ends of small thin strips of wood groove C. Free Ex- will appreciate this handy little device. It A screw-eye can be placed in the top of amination Se Se res is constructed of hard wood. ; A is a block of wood cut like a miter box, which is screwed and glued to the body B. This block also serves as a sup- port when planing. the body B, so that the device may be hanged on the wall when not used. The illustration gives the dimensions. a2 t-- 5%" 8 jks B is the body upon which the board to be planed rests. - - C is a flangelike groove cut from B, in which the plane slides back and forth. D is a support that is screwed and glued to B to keep the bench-hook from sliding OE 5 3 SE Re 5 a cae a all over the bench when used. CHICAGO Please send me the 5 volume Cyclopedia of Car- pentry and Contracting, shipping charges collect. I will send you $2.80 in seven days and $3.00 each month until $24.80 is paid or notify you to send for the books at your expense. If I buy the books I get a membership in your society free. corny eee gene arse dere SEE SET: Soe waeranrsydeewehoecareeers-~ the plane against the wood to be cut, the ends of small strips ERR AEE ATO LE HERON To plane the ends of a piece of wood, fe Be ca t,...), Veen 9 the wood on the body B and against i MP HStV ist chans sb ccbbcdccaccess ARERR ys ock A: then lay the plane on its side 0 ie : y a NNR 6608565150 coven dstenenoas the cutting edge is vertical. Then push Li nate ype on pour workings i Please fill out all these lines |

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p, Uleyes B eiNe December, 1921 93 EUSTON | = “a Buy Your Boy yaw a STRUCTO Toy! Build Structo Autos that Look and Run Like RealCars! ‘Wo. BUILDING a STRUCTO Automobile, Truck or Tractor is fine sport for any boy. ae. Green eter. Sa trite These toys are realistic reproductions of real automotive machines. They have parts like real cars. You assemble the parts and build your own Auto, Truck or Trac- tor. Youcan build a fast, sporty, Racing Car; a classy Roadster, a big Dump Truck ora sturdy Tractor. STRUCTO models run fine, too! They have strong, powerful motors that drive them straight ahead or around in a circle; up hill or on the level. Some have sliding gear transmission and regular ‘“‘big car’’ differential, with gear and brake levers; others have direct shaft drive, while the Tractors have directly connected gears that give them pulling power for slow speed work. They all have many features of real cars, and are handsome, strong, sturdy machines you can have a lot of fun with. 4 | ; Outfit No. 10. A sturdy powerful road- They are so well made they last a long time. ster, 16 in. long. Single-unit motor: direct shaft drive. Start and stop lever. $7.50 Red color, blacktrimming. - - There are six fine models to choose from: Nos. 8, 10, 11, 12, 14, and 16; all pictured here. Any boy can - build them; all the work is done. Just put them together and you'll have an Automobile, Truck, or Tractor that looks and runs just like a real one! Look over these There are also four dandy Ready- Built STRUCTO models; Nos. 40, 42, 44, and 48. These are ready built for you and ready to run when you. get them. They’re wonderful machines and have strong motors that keep them going a long time. c Just like a Reat The Caterpiller action of the No. 44 = ‘ models; read the specifications for Carl The No. 12 Tractor and the No. 48 Tank is very Structo High Wheel Tractor; Trac- each one and decide which you’re | Model has trans- realistic and these toys have remark- tor-Builder Outfit No. 11. Triple-unit goingtohave. Any fellow’s Dad will mission and differ- able power fcr their size. Finished motor. Start and stop lever. Most begladtoseehimbuildaSTRUCTO Qntlalshownabove. — in colors and very attractive in ap- Be Gabi Auto because it helps him under- ne ~ pearance and action. Each one i vicinity - ae parts like real ma hoe Extra Trailers $1.00 each stand how real autos are made. chines. comes in its own box. SVCEUVLEAGUEUTATAVINGSUOUUOOOOUOUUOVUAROUOUOOOGRGONOOOOOUONUTNTOOTONOOOOOOOOEOEGEROOSUEOOOOUONENUOOOOODAGOENUOONUYOCONOQOQENOOOUDIOOOQQOQRUTONEOQUOBNSOOOOUNNOOQGQG0UOUUONGSGQ0OGQOQODUUOOLOSNOEUOUNOOOUQUUGOOUOGQOUUOOOOOOUQUGOOQOOUOUOOOOUGOOOOOOOOOOEEAHIOUOATY Ask for STRUCTO TOYS in the Toy Department, Hardware Store, Toy Store and any store where good toys are sold. Be sure you see the aT = name “STRUCTO TOYS” on the:box because then you’ll “ @\S j§§_ SES = have the best ones. If you cannot find the one you want = we will fill your orders direct, upon receipt of price listed. = oa : — STRUCTO MFG. CO., Freeport, Illinois at = Structo Dump Truck; 12 TR, Bullder = — : 0.; 14. °-Trip t — Sandetes Aman: Riete- West of Denver, Colorado, and in Canada, prices are _ motor; sliding - gear oes SN. Built: Model No. 40. (A 10% higher. ion ; forward and reverse = speeds. -18in. long. Has ping attachmenent. Re strong, speedy car, dum color. - - - - - - $12. 10% in. long. Red with black trimming. - - $3.50 ° eee Structo De Lure Auto; Auto-Builder Outfit No. 12. Just like a real car! 16 in. long. Triple-unit motor, “big car’ transmission, and Caterpiller Tractor; Ready- Built Model No. TUTTI Contractor’s Dump 44. 11% in. long: differential; clutch and Truck; P Pesdy-Bullt very realistic in Detergiliee Praag} peas =. Two speeds lel No. 42. Has y action. ¢ har- ‘ank; ye orward and one reverse. Yuba Tractor; Tractor- lifting and lowering lever. row included. Model No. 48. 12 in. Disc wheels, low body and _ A perfect ees ree Pipa tay Foe Tg 12 in. long. Orange with Green and red with long. Gray with red other regular car features. Powerful double-unit motor: control handle black and nickel trim- black ceeae trimmings: Gun mount Orange and black colors. and stop and start lever. One trailer included. ming. - - - = $4.25 00 inturret - - - -- $5.00 $10.50 20 in. long over all. Blue and red color. $8.50 r STUTUTVVNNOUUEUNTUUNVEOUGUTUANIARTASOVOTVAEUUOEEURUVOGOOUOOGEUGOEARUGRANOOUARGOUOOVROAUIUTUUUOOREUTROOOOEOGSEOOGSATOOEGOUOGENRUTOOOUUUSGUOUOOESEOUSTOETATOTOVDRTTTOTHATSNTN i STAT

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94 $ Saree ttn Joes om Neccheneesber ee Ti ‘, ad ~ fo A tan SE ROY tr MB er OT pemretics pes oo REWARD TWO HOURS WORK In answer to a request from Chief of Police, Warren Biglow, the Finger Print Expert ar- rived at the scene of the daring robbery of the oO Company offices. $6500.00 in currency was gone. Not a single clue had been found. Almost immediately Biglow turned his at- tention to a table which had been tipped up. The glossy mahogany showed an excellent set of finger prints. The thief might just as well have left his calling card. To make a long story short, his prints were photographed, and matched with those of “Big Joe’’ Moran, a safe blower. Moran was caught and convicted on Biglow’s finger print proof. The money was recovered and a $500.00 reward given to Biglow, in addition to his fees—as pay for his two hour's work. Be aFinger-Print Expert Learn at Home in Spare Time " No more fascinating work than this—and big rewards go to the EXPERT. Thousands of trained men are now needed. The Finger Print work of governments, corporations, police departments, detective agencies, banks, individuals, has created a new profession. Many experts earn $3,000.00 to $10,000.00 a year. And now you can easily learn the secrets of this new science in your spare time—at home. Any man with a common school edu- cation can become a Finger Print Expert ina short time. Finger-Print Free Outfit and Large Illustrated Book We are making a special, limited offer of a complete Professional Finger Print Outfit and a Course in Secret Service Intelligence, both ab- solutely FREE. Mastery of these two profes- sions offers you a brilliant career. Write quickly for illustrated free book on Finger Prints which explains this wonderful training in detail. Don’t wait—mail the coupon NOW. You may never see this announcement again. University of Applied Science Desk 1369, 1920 Sunnyside Ave., Chicago Pt ge epee eames University of Applied Science Desk 1369, 1920 Sunnyside Ave., Chicago, Ill. Gentlemen: Without any obligation what- ever send me your new, fully illustrated. FREE book on Finger Prints, and your offer of a FREE Course in Secret Service Intelli- gence. MN SOF. a tcictn bets sks aes be oe | are NE As osc onkas seek s ioe ee PG kt escbaswu pene coawes SEE sole vss 0 Earn $2500 to 9 95000,3. faite Fe S24 320= ana Se OE Re peovren—nesremnsirwetgn pemniienternee eg oe cate ae aoa = Sig snal Engineer b ition cet ig positica of fascinating | agement where gant success, swift promotion and a high salary await you. " Rail- pe hs fmm | need ves Bl electrical safety devices. Book FREE Send guick for bie flo Sirnef Eneioeerng and sro hat shed eae to-day ’t delay’ ee; a al ey mele or a os un, De —_ ot gat Popular Science Monthly THE HOME WORKSHOP A Boring Table for the Small Lathe A BORING or milling table is a useful accessory to the small lathe and the illustrations show how one may be made and fitted to the lathe cross-slide, using the original cross-feed screw. No planer or shaper work is required as all work is per- formed either in the lathe itself or on the bench. The device consists of a cast-iron table, either with a plain top or with slots cast in place, as the builder desires. The lower side of the table has a ledge around it to add strength and two lower bosses to which the V slides are bolted. Corner bosses, with holes through them, are shown; these, in the original apparatus, were intended to take a 4-horsepower motor with a grind- (Fr er ms oO | Psi /\o oh i © / CROSS SLIDE \ ' ! SCREW NUT \ ' l Ka | 1 © DETAIL OF C3 Ua eee ay V- SLIDE Ke : tI Z CR STEEL ORCI: 2 REQD. ADJUSTING NUT ENLARGED HOLE STUD IN SLIDE Owners of small lathes will find this boring and milling table very useful in their work ing-wheel, bolted to the table for special grinding work; but the holes would also accommodate clamp bolts for large work. A pattern for this table is easily made, as there are no cores or loose pieces. If the builder does not wish to use a casting, the table could be made of a piece of heavy iron plate. As the position of the feed- screw nut, if cast in place, would in all probability interfere with the machining of the bosses, this is made separately, tapped or threaded and screwed to the bottom of the table. Two V slides are made, e‘her of cast iron or from cold-rolled steel stock; if the latter, the V slides must be filed or sawed to shape. Cast-iron V slides will have to be file-finished on the surfaces that bear on the cross-slide V’s. They could be bolted to the face-plate and faced off in the lathe or ground on a high-speed’ abrasive grinding-disk. The table casting itself is drilled and tapped for four holes, in the corners or otherwise, and bolted to the lathe face- plate and faced as nearly as possible to a plane surface; it-is then reversed and the two under bosses are faced off. Next, the V slides are bolted in place, one of them being made adjustable after the somewhat novel method shown. Steel studs are set into the table and the V slide is set up by nuts on the ends of the studs. The holes in the slide are larger in diameter than the studs or are filed lengthwise to allow of a small amount of take-up. Smaller holes are drilled in the outer edge of the slide and corresponding ones drilled and tapped through the studs to take fillister-head machine-screws. To adjust the slide, the lower nuts are slightly loosened and the machine screws turned in, which will draw the slide against the cross-slide V’s. The nuts are then set up and the adjustment is complete. If no slots are provided in the table-top for holding the work, holes may be drilled and tapped at convenient points for clamp- ing the work. The boring-table is quickly applied by drawing off the regular tool- slide and pushing the other on, using the same feed screw. Besides holding work for boring or milling and drilling, the table can be used, as stated above, for holding a small grinding-wheel motor for cylindrical or face grinding of work held between centers, on the face-plate, or on special brackets attached to the lathe-bed.—H. H. PARKER. Piping the Flow of a Spring yz often when a spring is located in a low place and used for stock drinking- places, the trampling of the stock will break in the sides of the spring and cause it to fill up and get swampy. It is possible to pipe a spring of this sort so that the water may be carried to a distant point and allowed to run into a watering-trough. First it is necessary to clean out the spring location to a good size and without making the depth any greater than neces- sary, but trying to arrange the spring so that it will have good solid sides or walls. Take a short length of pipe, about 1 in. in diameter, and set it upright in the center of the spring and at a short distance from the bottom, being careful to keep the water baled out as it enters. Fill around the bottom of the pipe with good sized clean stone and then over that with fine sand and gravel to within a few inches of the top of the basin. The work must be done quickly. Then pack over the top with thick clay that has been previously prepared, and ram and tamp down firmly all over the top of the spring location. This makes a top coating that will not allow the rising water to seep through and later it can be covered with a layer of concrete to prevent rains from washing away the surface. The rising water can find an exit only through the pipe. Some experimenting may be neces- sary to find the correct height of pipe. An elbow screwed to the upper end of the pipe and a length of drainpipe screwed into If you have a spring on your land you may improve it by collecting and piping the water as shown the elbow is —_ to carry the water to the trough placed at a slightly lower level than the spring.—B. F. DASHIELL.

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ae Ee oA a ae. EN A, al e December, 1921 Larger Picture Puzzles Free Observe These Rules 1. Any person who is not an employes, or relative of any employee of the Minnesota Pen Co., may submit an answer. It costs nothing to try. seit All answers must be mailed by December 24, 3. All answers should be written on one side of the paper only, and words numbered 1, 2, 3, etc. Write your full name and address on each page. 4. Only words found in the English dictionary will be counted. Do not use obsolete, hyphenated or compound words. Use either the singular or plural, but where the plural is used the singular cannot be counted, and vice versa. .6 Words of the same spelling can be used only once, even though used to designate different objects. An object can be named only once. However, any part of the object may also be named. 6. The answer having the largest and nearest correct list of names of visible objects shown in the icture that begin with the letter “C” will be awarded rst prize, ete. Neatness, style or handwriting have No bearing upon deciding the winners. 7. Candidates may co-operate in answering the puzzle, but only one prize will be awarded to any one household; nor will prises be awarded to more than one of any group outside of the family where two or more have wor! together. 8. In the event of ties, the full amount of the prize will be paid each tying contestant. 9. Three well-known business men, haying no con- nection with the Minnesota Pen Co., will judge the answers sub and award the prizes. Participants agree to accept the decision of the judges conclusive. The following men have agreed to act as judges of this unique compétition: ~ . B, Ben’ Cashier Produce Exchange Bank: st Paul: oR Reinke. Principal, Franklin, Public Sebool, 5. Paul; K. W. Husted, Civil Service Bureau, 10. All answers will receive the same consideration ao oe of whether or not an order for a Minnesota fountain Pen has been sent in. 11, The announcement of the prize winners and the correct list of words will be printed at the close of the contest and a copy mailed to each person pur- chasing a Minnesota Fountain Pen, Thsasstihan. 20020 How to Win $1,500.00 The purchase of one of our $5 Minnesota Foun- tain Pens makes your answer to the picture eligible for the $500.00 Prize, as shown in the second column of prize list. However, as we want more people to know our pens, and as a special adver- tising feature, we are making this Special Christmas Offer As a special Christmas Offer, we are offering the grand prize of $1,500.00 to the one who sends in the best answer to the above i pro- vided_he has purchased two of our $5.00 Minne- sota Fountain Pens at our special Holiday Price of only $9.00. Two Five Dollar Pens for $9.00, is all. Or if you would prefer, three $3.00 Minnesota Pens at $9.00 will also make you eligible for the $1,500.00 Prize. Answer the puzzle and send your order now. State Style of Pen Wanted The Minnesota Fountain Pen comes in two styles, ladies’ and gentiemen’s, in both the $3.00 and $5.00 sizes. The pens pictured here are our five dollar ladies’ and gentlemen’s pens. The pic- tures shown are about two-thirds the actual size. In ordering state whether you wish fine, medium or stub point. Money-Back Guarantee We guarantee Minnesota Fountain Pens to be perfectly satisfactory. If you are not satisfied with it on arrival, return it and we will exchange it or refund your money. MINNESOTA PEN CO. Dept. 715 Saint Paul Minnesota 95 FLERE is an opportunity for you to get a handsome Christmas Present for yourself. It is not a fanciful dream but a straight out and out opportunity for you to win $1500.00. In the picture here, you will find a number of objects and parts of objects whose names begin with the letter “C.” Pick out ob- a like cat, cane, chest, etc. Nothing is idden. You do not even need to turn the picture upside down. Everybody Join In It Costs Nothing to Try Sit down right now and see how man “C” words you can find. The object of this picture puzzle game is to get more people acquain with Minnesota Fountain Pens. Thousands of them are now giving satisfac- tory service every day. We want you to buy one of our sane tet yourself and another one to use as a gift. A Minnesota Fountain Pen makes a hand- some Christmas present, and it will solve the problem of deciding “what shall I give for Xmas?”’ Fun for All the Family Start in now and see how many “C” words you can find. All can join in, from the old folks down to the little youngsters. You'll fave loads of fun, and if your answer to the pic- ture puzzle is awarded lst prize by the Judges you will win $20.00. However, by _pure chasing a Minne- sota Fountain Pen you will be eligible for the big cash — — b csenstaall =" = How Many Objects Beginning with “C’’? Can You Find in Picture? _ prizes. perenne RE seer ee MINNESOTA **The Easy-Writing Fountain Pen”’ You will find the Minnesota one of the finest pens you ever used. The ink flows smoothly, and ou can’t resist the easy way in which it writes. nless our pens were the very best that money can buy, we could not afford to advertise them the way we do. Thousands of them are now in use. Their popularity is increasing by leaps and bounds. If you need a good pen, or if you would like to make a useful and handsome gift to someone, the Minnesota is just what you have been looking for. The pen speaks for itself. We cannot tell you in words, what five minutes’ use of the Minnesota will tell you. a tee en natin 0M Satisfied Users Everywhere In New York, in Chicago, in Boston, in St. Louis, in San Francisco, and in fact in almost every town and on many a farm you will find the Minnesota Fountain Pen. The ink flow in the Minnesota is perfect. It does not blot or stain the fingers. riting becomes a real pleasure when you use the Minnesota. p= THE PRIZES "= If ng If one If $9.00 pens are $5 pen is Worth purchased purc Pens are purchased ist Prize $20.00 $500.00 $1,500.00 2nd Prize 10.00 250.00 750.00 3rd Prize 5.00 125.00 375.00 4th Prize 5.00 75.00 187.50 5th Prize 5.00 50 00 100.00 6th Prize 3.00 25.00 75.00 7th Prize 3.00 20.00 50.00 8th Prize 3.00 15 00 40.00 9th Prize 2.00 15.00 30.00 10th to 15th 2.00 10.00 20.00 am

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& SSE ct eee idee pment a ae Fa ne Ne 9A ee oF ante re morte se tunecag es many ae ye ~ eee Stes “>> SF PR 96 Choice On Trial WURLITZER will send you amy in- in your own home. No obligation to buy. Return the in- strument at our ex- pense at the end of the week, if you decide not to keep mgit. Trial won’t cost you a penny. Monthly Payments wy) A few cents a day will / pay for instrument and complete outfit. Complete Outfit You get with the instru- ment everything that you need — velvet and + oat lined car rying case with lock and key, accessories, extra parts, self instructor, music, etc. — all at 4 direct cost, practi- cally for the cost of instrument alone. Wurlitzer has made the finest musical mstruments more than 200 years. All instruments in- cluding Pianos and Victrolas, are_em- braced in the Wur- .. litzer plan. Send for New is tS. free. oer} the coupon now. The RendelhieateaseOo. Cincinnati, Ohi o, lll. New York, N.Y. Popular Science Monthly THE RUDOLPH oe co. Dept. 1789 517 East 4th Street, Cincinnati, Ohio 700 Jeckoon Bia, Chicage I 120¥ ‘2ndSi, NewYork. NY Send me your new ca‘ with illustrations in color and full of the Wurlitzer Complete Outfits and details of the free trial and easy payment offer. DUGING. .ccccccvccvesescococvecccnsencovccccoccccccccccce ° Address Seeereceeeeseesesoseees Seeeeeseceeeseesrecee. ee grees tetas coencocses weeecnssacseceeseseeeses ce n-ars THE HOME WORKSHOP ead How to Make and Fumish a Doll’s House By E. Bade Make the framework of the doll’s house from parts of an old box, an saw doors and windows to suit can make for her a doll’s house from an old box and some odds and ends of wallpaper. Any strong box about 20 in. long, 1 ft. deep, and 1 ft. high, can be used. One side is carefully taken out and all pro- jecting nails removed. Three squares, which form windows, are cut out from the back of the box, and a partition, with a large rectangle sawed out to represent the door, is nailed to the box, which now consists of two rooms—the dining-room and the bedroom. A door is ean boy who has a younger sister An open fireplace lined with brick- paper may made and provided with a mantelshelf made that must fit into the rectangular opening. This is later nailed to the par- tition with two small brass hinges so that it can be opened. Cornices are nailed around the top of the box. This gives the finished house a realistic appearance. Brick or wood paper is glued to the out- side of both sides and the back of the box, while the inside is finished with odd pieces of wallpaper. The windows are fitted with glass and small strips of wood represent the sills. The furniture for this doll’s house may be made of cigar-box wood. The tools re- quired consist of a knife, a hammer, and some small nails. Paint or stain can also be used, although this is not absolutely necessary. Chairs, beds, and benches are made from strips of cigar-box wood. These should be Brick-paper is ted on the outside of the house pe the windows are provided with frames about 3% in. wide, and as thick as the wood. It is best to cut the wood with the grain. This will make the strips as long as the box. They are cut into suitable lengths for the legs, sides, and seats of the different pieces of furniture. To make a chair, cut two 314-in. pieces for the back legs, and six 1)4-in. strips for the seat and the braces, and two other 1\%-in. pieces for the back rest. Arm- With a little patience a complete set of furniture for the doll’s house may be made of cigar-box wood chairs, Morris chairs, and rocking-chairs are similarly made The same method is employed when making the bedroom furniture. A dining-room table is made from an empty spool, preferably a large one, upon which a 3-in. square of cigar-box wood is nailed. If the table should not be high enough, two or three thicknesses of wood can be nailed under the spool. These will represent the feet of the table. An. open fireplace can also be made of a small box about 3 in. square with one side removed. Slanting sides are nailed to the The arrangement of the interior and the addition of ornaments may be left to the taste of the owner box to represent the chimney. About Yin. above the box, one of the strips made for the furniture is nailed around it. This will give the appearance of a mantel. To heighten the effect brick-paper is glued to the wood. “Every-Day Wonders” Beginning with this issue, POPULAR SCIENCE MONTHLY will publish | each month ten questions on general. science that affect your daily life. To know and understand the an- swers means that you have laid the foundation for a sound education. The questions will be found in this number on page 32. The answers are printed on the same page.

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—— oe ue — ew Re ee epotir> December, 1921 THE HOME WORKSHOP Wood Puzzles that Will Interest Your Friends tee 1 shows a piece of wood with a round, a square, and a triangular hole in it. The puzzle is to cut one piece of wood that qill exactly fit the three holes. To do this, get a cylindrical piece of wood that will exactly fit the round hole in Fig. 2. From this cylindrical stick cut off a length equal to its diameter. If put in sideways, it will fit the square hole. Now draw a line through the center of the circle across one end and from the circumference © L FIG. 2. FIG, 4. The peg to the left will fit a round, a square, and a tri- angular hole of the other end cut a bevel to this line. The plug will then fit each hole. Figure 3 is the mysterious dovetail. It seems impossible to make, as the mortises apparently run through each other from each side. Figure 4 shows how it is made. Join two square-cornered pieces of wood neatly and carefully by two mortises. Then chisel the corners off to the dotted line, leaving another square block as shown in Fig. 3. Figure 5 is one piece of wood passed through another, which just fits the stem, FG. 3. FIG. 4: FIG. 5 FIG. G. The construction of two puzzles that can be cut from a block of wood or narrow part, and has no joint. It may be made either by choosing soft wood and soaking it in boiling water until compress- ible, or, better, by making two pieces like Fig. 6, and gluing them together. The joints, being at the corners, should be quite invisible.—E. A. MCCANN. Do You Know How to Make a Glue-Joint Invisible Y= making a glue joint, always, if possible, lightly sandpaper the joint before the glue dries. This will fill up any slight crack with fine sawdust and greatly aid in hiding the joint.—E. A. McCann. 97. Democracy “__of the people, by the people, for the people” People of every walk of life, in every state in the Union, are repre- sented in the ownership of the Bell Telephone System. People from every class of telephone users, mem- bers of every trade, profession and business, as well as thousands of trust funds, are partners in this great- est investment democracy which is made up of the more than 175,000 — stockholders of the American Telephone and Telegraph Company. If this great body of people clasped hands they would form a line more than 150 miles long. Marching by your door, it would take more than 48 hours of cease- less tramping for the line to pass. This democracy of Bell telephone owners is greater in number than the entire population of one of our states; and more than half of its owners are women. There is one Bell telephone share- holder for every 34 telephone sub- scribers. No other great industry has so democratic a distribution of its shares; no other industry is so completely owned by the people it serves. In the truest sense, the Bell System is- an organization “‘of the people, by the people, for the people.” It is, therefore, not surprising that the Bell System gives the best and cheapest telephone service to be found anywhere in the world. “BELL SYSTEM” toward Better Service AMERICAN TELEPHONE AND TELEGRAPH COMPANY AND ASSOCIATED COMPANIES One Policy, One System, Universal Service, and all directed $1.00 The most compl model sen! ated. on Speen 24 inches by 36 inches, either set sent postpai Send 2c stamp and address of three interested friends for our new price list of guaranteed model and W. H. PHIPPS CO., Aero. Dept., Baldwin, Long Island, N.Y. START BUILDING your own MODEL AIRPLANES Aeronautics offers the biggest and best Geld in the world for ambitious young men. Val uable sport. Our new & sise Ay ym show ire aside, top and front vie' jel aero- plane. anerous sketches > y details show actly to cut and fit each and make Sones for you to build and fly se accurate minatures of famous aeroplanes. LOENIN RACING MONOPLANE NOW READY OP NGdT BpLANE lete and easiest understood plans ever Pie: « (State which you want.) Aviation principles quickly learned by building models Standard Underwoods Keyboard 2149 Shipman Building EMPORIUM. . co. Chicago, Iilinois PROFESSIONAL TONE MUSICAL INSTRUMENTS (Guaranteed as represe nied or money refunded. 5 FR Ret sent on free trial. Violin, Tenor o, Hawaiian Guitar, Ukulele, Mandolin, Cor- net, Banjo Mandolin, Banjo Ukulele, Guitar, BanjoGuitar, or Banjo. Wonderful new copyrighted system of teaching note music by mail. Four eg will teach you several pieces. Over 100,000 successful players, not miss this free trial offer. Write for booklet. No obligations. SLINGERLAND SCHOOL OF MUSIC, Inc., 1815 Orchard Street, _Dept.135, Chicago, Illinois

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Cee ~ - x agteyys eee ee sraned vennnntanpwerannereetddens extn SS: i HH ie i iM we i ai ' i i i i “ie | to a It told how surprising thing. hand. “T want to con I.c.S. I am training yourself job but for the j “We're cuttin one of the men comforts that go mail it to Scran BOX 7647-B Sheet Metal Navigator Worker Architectural Draftsman | PLUMBING AND HEATING TheLetter That Saved Bob Johnson’s Job —and paved the way better one! T was written to his employer by the International Correspondence Schools. ‘Robert Johnson had en- rolled for a course of home-study and had received a mark of 94 for his first lesson.” Bob answered the summons to the Chief’s office with just a little fear and trembling, for a lot of men were being dropped —a lot more were having their pay reduced. But as Bob came in, his employer did a He got up quickly from his desk and grasped Bob warmly by the gratulate you, young man, on the marks you are making with the glad to see that you are not only for your present ob ahead. g the pay-roll. Until I received this letter, I had you in mind as to be dropped. But not now. Keep on studying—keep your eyes open—and pretty soon there’ll be a better job for you around here. looking for trained men.”’ Won’t you let the I. C. S. help you, too? Won’t you trade a few hours of your spare time for a good job, a good salary and the We're always with it? Then mark the work you like best on the coupon below and ton today. That doesn’t obligate you in the least, but it will be your first t big s step towards success. o—e === =8"TEAR OUT HERE Se oor cee oe == “INTERNATIONAL CORRESPONDENCE SCHOOLS Do it now! SCRANTON, PA. Explain, without obligating me, how I can ay for the position, or in the subjects before which I mark X. ELEOTRIOAL ENGINEER | OHEMIOCAL ENGINEER Electric Wiri SALESMANSHIP Electric Lighting ADVERTISING MAN Electric Car Running tena: hl Trimmer oor senate Traction RAILROADPOSITIONS Electrical Draftsman ILLUSTRATOR Electrie Machine Designer DESIGNER pategears, Expert BUSINESS MANAGEMENT BEONANIOAL EAGINZER Private 7 Mechanical Draftsman Dainese Corseep oudent p Draftsman Stenographer and Typist eam Shop Practice Cert. Pub. Accountant oolmaker Traffic Management Gas Engineer Commercial Law CIVIL ENGINEER GOOD ENGLISH Surveying and Mapping STATIONARY ENGINEER MINE FOREM’N OR ENGR CIVIL SERVICE ARCHITECT Railway Mail Clerk Textile Overseer or Supt. AGRICULTURE PoultryRaising i ie Spanish Present re tion Business —— Addres Street and No City. State. Canadians may send this coupon to International Corre- Co @pondence Schools Canadian, Limited, Montreal, Canada See it first. We send ie very 8 only $5.00 mozith no Avth Street and Maree The Burlington 71 J . jewel waich s goer Under no obligation ¢ yy Aa el watch so ou at a price a great deal lower Sins taet of ether tah rate ee $52°a month The 4 -Jewel ay {s Free Book svar produced 100 eae fully fl strated Le Wars for it her is free. A letter or post card til don ewels it for you a a free woe AN (gon) ror interest. Send for full information. 1369 pany, Dept. Aye Riva, ¢ , inols : 62 Albert St.. Winniner THE HOME WORKSHOP Popular Science Monthly #60 DRILL CHECK NUT TIGHTENCD HAND-WHEEL REMOVED Your fingertips will tell you how to feed the drill without breaking it O drill a hole with a small drill in a piece that is chucked in an engine lathe, without breaking the drill requires great To Prevent Breaking a Small Drill By Albert Strandin First Prize, ‘‘Best Idea’’ Contest, December skill and patience. The least bit of excessive pressure applied to the hand wheel will result in a broken drill and many times in a spoiled job. To eliminate this trouble, the writer evolved a simple scheme that works very satisfactorily. By removing the hand wheel on the tailstock shaft and tightening the nuts in place, as shown in the picture, the worker, by the use of his thumb and forefinger, can obtain a very sensitive touch for feeding the drill, which otherwise would not be possible. N excellent oven for the oil- or gas- stove can be made from an old wash- boiler and a length of stove-pipe, heavy tin, or galvanized iron. Centered on one side of the boiler, mark out a 9 in. by 12 in. space; the 9-in. width beginning about 2 in. from the top and bottom if the utensil is standard. In the center of this space cut out opposite flaps, each 4 in. wide, and bend them up 2 in. and over at right angles to form supports for the oven bottom. Cut each side flap far enough so that when it is bent back and up 2 in., the supports will be about where the curve commences, as shown. This cut- back will probably be 4 in. Cut the bottom 10 in. wide and with the ends bent over 1 in. to fit over the sup- ports. Cut each side to fit in the boiler with one end bent 1 in. at right angles. Slit each corner of the tops far enough to | bend down and out 1 in. midway of the | | oven on which a second bottom or shelf can | rest. | Make this out of heavy wire doubled This Boiler-Baker Is a Boon to Housewives By Roland B. Cutler Second Prize, ‘‘Best Idea”’ Contest, December back and forth to the right width, and fasten at the ends with lengths of tin 2 in. wide, doubled over and riveted between the wires as shown. Punch a \-in. hole in each end of the boiler, 2 in. above the oven- bottom level for ventilation. BEND DOWN The handy man may construct this baking-oven from an old wash-boiler in this department. as a possible prize-winner. be purchased at space rates. same month home, office, or shop. B. Cutler, Springfield, Vt. monthly feature. $75 in Prizes Each Month for the Best New Ideas FIRST prize of $50 and a second prize of $25 will be awarded every month to the authors of the two best articles appearing Every article submitted will be considered . Those which do not win prizes may The prizes will be awarded upon publication and checks will be mailed to the winners during the Prize-winning articles may be long—but not over 1000 words— or they may be very short. The idea, device, or machine described must be practical and ingenious; it must fill an actual need in the This contest must not be confused with other contests which Popular Science Monthly is conducting at this time. Prize-Winners for December The two prizes of $50 and $25 for the “Best Ideas” appearing in the December issue of Popular Science Monthly have been awarded respectively to Albert Strandin, Chicago, Ill., and Roland These two ideas were considered by the judges to possess the highest all-round merit. It should be remembered that this ‘Best Idea’’ contest is a You may have an idea that will win the prize next month. Read the rules above. Popular Science Monthly ee

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December, 1921 | THE HOME WORKSHOP Improved Spur for Stump- Boring Auger ECAUSE of thefact that when oneis bor- ing a hole in a stump prepara- tory to blasting, one cannot tell when the screw at the point of the auger will leave the solid wood and get into soil, so los- ing its feeding This method of - — changing the spur ; - of the auger makes having the side it efficient cutting spurs at right angles to the cutting lips. Such an edge will allow of cutting down into the roots. When a rounded spur auger is used, the rounded form of the spur will tend to force the auger out of the wood, while it is almost impossible to cut small, fibrous roots. If you take a file and cut the spur to the shape shown, the edge, being at right angles to the line of cut, will sever all wood and roots with ease. Can-Opener Easily Made from Strap Iron (CC A-OPENERS « can be made in any de- sired size by using a straight piece of light-weight strap iron or steel as shown in SAW-CUT AND BEND im 4m in This can-opener, made from a piece of strap steel, will be found effective or cans of one size SHARPEN ) CUTTING-EDGE the drawing. One end is pointed and a cut is made in the piece at an angle. The end and the cut are bent as shown. The cut- ting edge must be sharpened. Here Is a Use for a Discarded Gasoline Barrel Vee a little work, a gasoline barrel may be turned into a refuse- or waste- burner.. The top of the tank should be removed with a hatchet or tin shears. A small door should also be cut in the side of the tank next to the bottom, to be used as a draft- door. Then astand made of strong strap iron, which is easily procured . should be placed \\\ eae. in the bottom of \|\ the tank. A wire screen resting on this stand will serve as a grate. When waste is ig- nited in the tank, ORAFT STRAP~IRON it will burn rapid- OR = SCREEN SUPPORT ly and with safety 4 waste-burner for from sparks. the back yard TOP REMOVED Appreciated Present Watermans(dea)Fountain Pen HE world-wide bcs rn of Waterman’s Ideal Fountain Pen suggests it as the perfect present for every member of the family. In addition to pride of possession, it brings with it years of faithful service that endear it more and more each year. ~ THREE TYPES: Regular Safety Self-filling with a choice of natural iridium pointed gold nibs to fit any individual pen preference. $2.50 to $250 Ee Selection and Service ; " at Best Dealers the World Over The quality standard in all Water- man’s Ideal Fountain Pens is the same. The difference in prices is determined by size or orna- mentation. \,* E. Waterman Company 191 Broadway, New York => State St., 24 School St. Chicago Boston 17 Stockton St., San Francisco AUTO OWNERS Save half of your tire cost by using Double-Mile. CoudioTrese VB AND NUMBER IN CLASS. Either pin illustrated made with any 3 letters and 2 Scares, one or two colors pions Silver Ry plate, 25¢ ea., $2.50 doz. Sterling silver, 50¢ ea., $5.00 doz, Write for new catalog. BASTIAN BROS, CO. 390 Bastian Bidg., Rochester, N.Y, *eN ‘t FREE CATALOG IVE NAME OF SCHOOL OR ee? Ly @1@'@\e\e:@' @ i fr ft 1@1@: se. Cuts Faster—Fays for Itself Saw your own wood for winter. Make big pone cotting Yood for market. New OT- One-Man Saw Rig saves time and labor. moved. Magneto buy. 1.75 1.85 2.00 2 25 2.40 2.50 2.60 3.00 3.15 3.40 3.75 5 —our special cash toracdas detent soyer 305 Gm Gave % MILEAGE TIRE & RUBBER CO. December. 1991 2035 W. Harrison, Dept. 102, CHICAGO, ILL.

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> RA A t ¥ pte eee : pers ae enon a a TE ES ONES RE BOE ae Lae an aoe i eeriosindacinge tevaivangemamnineman sine ir orae aceaiampwnerres paaberrees Fe re ee — eh ensea lesion tacape-aenmeat anaemia caer ieredh retempemniendietengengenaieiuaa anti ntene tC Ss a Scena as ted steateeee | uy t Hi | = SE Sen ene Ee ee ee ee 100 Popular Science Monthly The Strength and Charm of Physical Perfection ! Learn the Secret =“ FREE! Learn of the tre- mendous curative power —the manifold uses of VI-REX Violet Rays in treating almost every known human ail- ment—Nikola Teésla’s great discovery! This book also contains charts and dia- grams of the nervous system and organic locations, and fully describes just how the Vi-Rex Violet Ray works its many mira- cles. Written in a simple style—devoid of all technical language. Vi-Rex Rays Assure for You Amazing Health and Vitality Enjoy Wonderful - Sparkling Health! Increase your store of energy, revitalize your worn-out cells, make every fibre of your body tingle with a new vim and vigor! All this you can have through the magic of Vi-Rex Violet Rays—right in your own home! Violet Rays penetrate to every cell in the body, im- parting that stimulating vigor which brings the glow of health, tones up the entire system, putting life into over- taxed and sluggish tissues. As a quick relief from pain, Vi- Rex has no equal. Headaches, nervousness, skin blemishes, and many other complaints vanish as if by magic through this marvelous ’ treatment. a Try the Wonders of Vi-Rex Violet Rays 10 Days FREE Find out how Violet Rays will help you! Demonstrate for yourself. Read what hundreds of users say about the VI-REX and the astonishing results which have been obtained. Learn why it is the most economical and practical machine of its kind available. There is no limit to its beneficial _- Just mail the coupon or send a postal. Doit NOW. — oe oe oe oe oe ee ee ee ee ee ee ee ee ee VI-REX ELECTRIC CO., Dept. 1512 326 West Madison Street, Chicago Please send me, without any cost or obligation, your free book describing your Violet Ray Machine, and details of your free trial offer. TOPO EHO REE HEHEHE EHEEOT OHHH OEEHEE SEES THE HOME WORKSHOP To Lift Locomotive Driving Boxes Vertically HE width of the device shown here can be made as desired, to suit the size of the box or of a size that will average reason- ably close for boxes close to the range of the lifter. The tong part is made of % in. by 2 in. iron, while the lifting hooks are of 4% in. by 1% in. by 21% in. angle-iron. The tongs extend down only to about the middle of the lifting pieces. These are fastened to the tongs by %-in. bolts on which the lifter can swing. Below the tong part a 5-in. filler is provided, which is riveted to the angles. A %-in. bolt is provided as a pinion for the tongs. Fastened or linked on to the lifting-ring, 5/16-in. chains are used. You will note the action, that in lifting, the pull on the chains transmitted to the tongs tends to close them on the box. Another very good feature is the safety chain, which is fastened by an eyebolt at one end and goes over a hook at the other. Hence, when the device is placed on a WROUGHT IRON Lifting-tongs of this type are very useful in shops where heavy loads of square forms must be lifted driving-box, an accident through the open- ing of the device is almost impossible. This device is well-nigh indispensable for placing driving-boxes on axles of locomo- tives and can also be used in lifting off boxes to be repaired.—L. J. BITNER. Wheelbarrow Wheels Can Be Built at Home I MADE a fairly good wheel in the follow- ing manner: Two circular disks were sawn from a 1 in. by 14 in. plank, the full width of the board. A %-in. hole was then bored in each and the two pieces were nailed together, crossing the grain of the wood, and using sixpenny finishing nails. Nails were driven into the disks about 14% in. apart from each side and the nails were clinched. Two 1 in. by 6 in. blocks, with the corners sawed off and each block chamfered on one side and %-in. holes bored through their centers, were then nailed to the wheel—one on each side— with the grain of the blocks crossing the grain of the piece to which it was nailed. These pieces also were shower nailed. A &% by 34 in. common pipe-nipple and 7/16 by 10 in. bolt and nut and four \%-in. cut washers completed the axle assembly. The %-in. nipple was driven into the hole in the center of the wheel, about 1% in. protruding on each side. The frame of the barrow was made so as to allow for a washer at each end of the nipple, or hub, of the wheel, and a washer under the head of the bolt and under the nut. In giving the length of the pipe-nipple for the hub, or thimble, and the length of the bolt which is to be used for the axle, it must be remem- bered that these lengths are for dressed lumber, which is only 13/16 in. thick; thus the four pieces when assembled will measure 3/4 in. However, if neces- sary to use un- dressed lumber, be sure that both the WHEELBARROW WOOD DISKS ° This wheel can nipple and _ the easily be made by bolt are long the amateur car- enough. Remem- penter ber, also, that pipe-nipples are measured inside, and, further, they are all oversize; hence you cannot use a %-in. bolt for the axle—the wheel would wobble too much. There is little likelihood of the nipple ever coming loose if it is driven tightly into the wheel. A wheel made in this manner will not only have very little wobble, but it will last for years; and it is inexpensive. A Weight to Aid in Lifting Heavy Doors A RESTAURANT I visit has a large icebox with heavy lift door. It is necessary for the waiters to raise this door many times. ee The ingenious proprietor placed a strong window-weight cord with weight attached over a pulley in the ceiling above the box, then attached the other end of the cord to the front of the icebox door. The weight is not quite so heavy as the door, but it helps materially, and the appliance is so A CEILING OR BEAM_” my Puuey WEIGHT Provide your cellar trapdoor with a unterweight and you will be able to raise it much easier arranged that the door stays open in a vertical position after being raised, allow- ing the waiter to use both hands in removing things from the chest.—A. W. Rokr. 102 Ponular Science Month), 7 egress

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December, 1921 THE HOME WORKSHOP , t Shoe-Polishing Rendered Easy with a Support © gies polish your shoes on a chair or other furniture. Make a _ shoe-pol- ishing stand. It takes up no room, does not disfigure the wall, is very useful, and is easy to make. All that is nec- essary for such a device are a few pieces of wood, a bolt, and a num- ber of screws of different sizes, a saw, a plane, and a screwdriver. First, two pieces of wood are cut alike, and planed down. These are the supports of the footrest. These When not in use, two pieces should the foot-rest folds be made of stout against the wall material so that they will not break by the strain to which they are subjected. The crosspiece holding the foot-rest should also be made from a stout piece of wood, and must be tapered. The end projecting outward from between the two supports can be made as thin as de- sired, although it should be at least 114 in. in thickness. The other end, espe- cially that part which lies be- tween the sup- _ ports, should be quite wide. When this piece has been cut, the footrest, which may con- sist of a thinner piece of wood, should be at- tached to the crosspiece. The bolt is The rest is turned passed through down when required the two supports for polishing shoes and through the cross piece. Then the supports can be attached to the wall at any convenient place about 1 ft. above the floor. When the stand is to be used, it is simply let down so that it stands horizon- tally. When out of use, it is lifted and rests flush with the wall. If Your Pipe Fails to Draw, Try This BRerORe loading the pipe with tobacco, place a small piece of steel wool in the bottom of the bowl, and press it down with the finger. Then the tobacco may be filled in. By doing this, you not only get an easier draft in your pipe, but it pre- vents the pipe from becoming clogged with small bits of to- bacco. The steel wool also stops the nicotine from going through eeing ‘ STEEL WOOL e pipe and may ‘ Steel wool in the bowl bechanged when- keeps the tobacco out ever necessary. of t_.e stem 101 ELASTIC KNIT UNDERWEAR Hanes 5 Big Features (Shirts and Drawers) 1 Hanes Stacncn Exastic SHOULDERS made with service-doubling lap seam. They fit right, with lots of give for every motion. 2 Hanes Exvastio Knir CoLLARETTE lays flat and snug. Keeps cold winds out and holds its shape. Hanes Exastio Corrs are made far stronger and better than the usual cuff. They fit the wrists firmly; they won’t flare and won’t rip from the sleeve. 4 Hanes 3-BuTton SATEEN WAISTBAND means real comfort-fit in drawers. Made of sturdy sateen, double-sewed, long wear is sure. 5 Extra Gusset IN Lecs assuring better fit and longer service. You’ll appreciate the extra comfort. GUARANTEED VALUE— that’s the word behind HANES Underwear Hanes Winter Underwear comes to you at the If your dealer can’t lowest prices in years—with the assurance that ‘SUPP!y you with , ro gp y Hanes, write us im- it will give long wear—or you get your money mediately. back! That promise is the Hanes guarantee! We know Hanes Underwear! We know what wear and comfort you'll get from those Hanes features shown in the illustration. Every operation in the manufacture of Hanes Hanes Guarantee Underwear—spinning the yarn, knitting, cutting ,, plainly. tiliain and tailoring, are done according to Hanes stand- Underwear, absolutely— ards—standards that have made Hanes the most {on” We guarantee to re- popular men’s underwear in America! jue oe ce cae _— See the Hanes line at your dealer’s! And re- breaks. member—there have been tremendous reductions in Hanes prices. There’s the longest measure in value in those heavyweight union suits, and shirts and drawers. You can see that with half an eye! And the mediumweight silk-trimmed union suit has won the admiration of thousands of extra warm-blooded men and indoor workers. acjiaiieneiiiine Union Suits for Boys — Made in two weights, pyypppinc c KNITTING COMPANY medium and extra heavy—in sizes from 2 to 16 years. Winston-Sel N.C Two to 4 year sizes have drop seat. aie tar cee tial Always look for the Hanes label when you buy. Nout Sumumurs\ou'll swant to oear anes Nainseot Vion Suis! AUTOMOBILE REPAIRING MADE EASY BUILDING AND FLYING AN AEROPLANE By Victor W. Page. A thoroughly practical book containing By CHARLES B. HAYWARD. A practical handbook complete directions for making repairs to all parts of the covering the design, construction and operation of aero- motor car mechanism. planes and gliders. 150 pages. Price, $1.60. 1,056 pp. Price, $4.00 Popular ‘Science Monthly, 225 West 39th Street, New York POPULAR SCIENCE MONTHLY, 225 West 39th St., New York M U R D EF R WILL Learn to Dance Police factories, banks and industries Wate. ang newest, u-t ‘up- -to-the- shinuts’” spclety dancet home--in private ‘a See pee are a. ting the finger print method of ew identification to locate erfminals. Peak System of Mail Instruction Be a Finger Print Expert eUeTs GUARANTECD Ne mrt —'no nares repores te res telling of the he uses fg a Pants and ‘how Yor A learn comet Tpossends OURSE OW TRIAL. Writs mo today. U. S. SCHOOL OF FINGER PRINTS for PEE Information and Law cee el Roomi049 7003 No. ClarkSt. Chicago, Ill. Studio 48 4737 Broadway Chicago, ll. — |HERE’ S AREM REAR FENDER BRACE FOR FORDS Si the squeak and rattle in —- rear x nders with Dunn races. Prevent breakage. They look well. Only $1.00 per pair, at your dealers, or, mai:ed pre- id for that amount. Easily nstalled yourself. End your fendertrouble. Send name and and start net t ‘e : 1.00 NOW. Shipped day order WW teach vou mal it tnatey Siatie aE omer Ynwtract yoy. 6 \ $1.00 Nc > ¢ _. |BUSINESS![ }O0 ONE DAY AT HOME | —— LEARN 2 HOURS manage ish outfi Suakeeene TANGLEY CO., 136 Main, Muscatine, lowa DUNN MFG. CO., 707 Main St., Clarinda, Ia.

Page 84

rey “SC on ee een A ee ee eters cn aramnanaen aetgbacarrean aoe emanate al SSS mow a i | i. i He

102 We whe, HAT others have done, YOU CAN DO! $6,000.00 year is low estimate. Many make more. This mew machine and Hay- Many Men Making Money Are you one of the crowd drifting back to 1914 wage scales? Protect yourself! Join the ranks of those who have for- among these money makers! H: ll, did $20,000.00 last year. Bros., Pa., made clear net profit of 3,500.00 durin first year. Spring City re Co., Wis., did about $26,000.00 to date, and expect year’s total to reach $50,000.00. Ramsay, S. D., working ne, Cleared $441.56 in one month. Wendt, Ind., opp month. Tucker, Iil., runs high as $127.00 weekly single handed. Mitchell, IIL, says “Record day was $360.00—last month did $2,600.00.”* And so on! Great Opportunity Now Above successes were made within past eighteen months, ‘These men took ad- vantage of splendid conditions. Right now car owners are economizing. Not buying new tires. Making old ones do, This work flooding Tire Surgery stations with cash business. Get My Big Proposition Start like others have done. Get the facts, There’s nothing to stop you. I'll help you to thelimit. My proposition is high y pe ys My machine is marvelous, Its compact design and size make small, handy shop possible. Its big i earns ‘money fast. Send this coupon or postal to me, personally, Write me tonight. ; M. Haywood, President HAYWOOD TIRE & EQUIPMENT CO, 1161 Capitol Ave. Indianapolis, Ind. Mr. M. H Pres. Havwood ipme i Fh leat Dear Sir: - Iam interested in Tire Surgery. Please tell me all about this profitable Guslenes. _*

~

Address

Popular Science Monthly

Dollars in Hares We pay $7.00to$1 8.50 and upa pair and express charges. Big Profits. We furnish guaranteed high grade stock and buy all you raise. Use backyard, barn, cellar, attic. Cone tractand Illustrated Catalog Free. STANDARD FOOD AND FUR ASS'N 407C Broadway New York

OU can earn from $1 to $2 an hour ip your spare time writing show cards. Quickly and easily learned by our new simple method. No canvassing or soliciting, we teach you how, sell your work and pay you cash each week. Full particulars and bonklet free. AMERICAN SHOW CARD SCHOOL

206 Ryrie Building, Yonge & Shuter Streets, Toronto, Canada

THE HOME WORKSHOP

You Can Make this Disk-Grinder Yourself By L. M. Jordan UTLINED in the illustration is a disk- grinder that is simple in construction and operation and grinds the disks auto- matically. Procure a piece of 1-in. shafting, 6 ft. long. This shaft is mounted in a box bearing near one end on a mounting attached to a bench as shown, and the other end passes through a 1-in. hole in the center of a piece of malleable iron 1 in. thick, 3 in. wide, and 3 4 ft. long, bent into the shape of the letter U. This iron lies on a block mounting on the bench, which is lower than that supporting the box bearing at the opposite end. The lower side of this U-shaped stud is fastened to the block support and the bench with two heavy bolts drawn tightly. Through another hole in this stud extends a short piece of the same size shafting 10 in.

SHAFT=COLLARS LLA TIGHT PULLEY HOLDING DISK’ SHAFT IDLING PULLEY With a little skill and few tools you can make an automatic disk-grinder long, 2 in. of the upper end of which are threaded for a retention nut. This short shaft is held at the proper height by two shaft collars. On the lower end of .this shaft is mounted an 8-in. gear in an in- verted position, beveled for right-angle driving. This gear is engaged by a similar 6-in. gear mounted on the drive-shaft as shown. A small wooden roller is mounted on the U-shaped stud in brackets made of strap- iron and riveted to the stud. This roller holds up one side of the disk level and the opposite side rests on the top face of a 3-in. emery-wheel mounted on the drive-shaft under the disk as shown. An inch of the short vertical shaft immediately under the threads is hammered square to fit the square hole in the disks. The disks are put on this shaft in an inverted position and a nut is screwed on to prevent them from coming off the shaft during the grinding. The drive-shaft is prevented from playing back and forth in its bearings by two shaft collars, one on either side of the disk support piece or U-shaped stud. The hole in which the shaft rests in this piece is its bearing at this end, and should be kept well oiled. Near the box-bearing mounting two small pulleys are mounted on the drive- shaft. One idles on the shaft and the other is fastened and drives it, with a small belt from the engine or countershaft. This allows shifting of the belt from driving pulley to idler when necessary to change disks. A flywheel is mounted on the end of the shaft to balance the motion and power of the grinder. The disk rotates at lesser speed than the emery-wheel and in an opposite direction. A small wooden roller supports one side of the disk, while its other side rests on the face of the emery- wheel. On account of the ratio of the driving-gears the disk does not rotate as fast as the grinder, yet fast enough to keep it cool and grind it evenly and uniformly. Many disks can be sharpened in a day with this apparatus.

A Capacious Fountain for the Poultry POULTRY fountain that will hold enough water for a large flock may be made from a square 5-gal. oilcan such as is used for automobile oil and of which the spout and the screw-cap were melted off. A strip 1 in. wide and the full width of one side of the can is cut and the can cleaned inside by scalding it with lye or washing it with gasoline. This strip is cut 14 in. from the edge or bottom of the can to leave a surface to which to solder. This surface is cleaned and scraped or sand- papered, so solder will adhere. A strip of tin 2 in. wide is now cut 6 in. longer than the exterior width of the can and the@nds are bent so it will just straddle the can. Clean this strip along one edge on both sides of the piece and both ends likewise so the solder will stick. Now lay the strip over the hole in the can with its clean edge along the bottom of the can and solder along the edge. Then pull the top edge away from the can about 114 in. and clean the sides of the can where the ends of the strip will be soldered and solder the ends watertight. Cut out pieces of tin large enough to cover the holes where the spout and cap were attached to the top of the can, clean the pieces and the can and solder airtight. Lay the can on its side opposite this open- ing and pour in water until it is full, then set it up. If raised from the ground by setting it on the inverted half of another can of like size, with small ventilating holes in it near the bottom, a brooder-lamp may be placed under it in cold weather. This will give the chickens warm water all winter. PIECES OF TIN SOLDERED OVER HOLES WHERE CAP & SPOUT WERE

& CAP MELTED OFF

yas - 3"\< yg a * WIDTH OF CAN, EXTERIOR How a large square oilcan may be transform into an automatic fountain for chickens =

SURNCRS: Dece fill the the t (a ur tu so

iv) = me

rr let eet ot ee CO 88 1G

ee

Page 85

December, 1921

THE HOME WORKSHOP —

—_ Try a Rubber Hose on the Grease-Gun T’S a messy and tiresome job at best to keep the differentials and transmission filled to the proper level with grease, and the job is often neglected for this reason. If a piece of rubber tubing is attached to the grease-gun, it is unnecessary to crawl

f REASE-cUN-7 Make your grease-gun more effective by adding a rubber tube under the car to lubricate a transmission. Procure about 5 ft. of 14-in. rubber tubing, obtainable at an automobile acces- sory shop, and wire it to the end of the grease-gun spout.—J. C. OTTOFY.

Transforming a Tea-Kettle into a Glue-Pot UT of an old kettle and a tincan, I have made the glue-pot illustrated and ithas given satisfactory service. An old water-kettle that I found in the attic was used for the water con- tainer, and an old tomato-can for the glue receptacle. A ring about 4% in. wide was cut 4 from a piece of galvanized iron, and soldered to the outside of the can to keep it ; : from resting on rnin the bottom of the CAN |" FROM BOTTOM kettle, and also to keep the kettle steamtight. The water in the kettle prevents the glue from burning

How to Prevent a Wood-Screw from Loosening OOD-SCREWS will quite often loosen in any construction where there is continued vibration. These may be effectually locked by the method shown. The screw is tightened down in the usual | way. A straddle tack is placed over the head of the screw and driven down, the middle section of the tack fitting into the slot of the screw. If the tack is not wide enough to fit over the head of the screw, a small brad may be driven down be- side the screwhead and bent over } until it fits in the ‘= “slot. Either way provides a simple a7" 1 method of keeping the screw from turning. — L. R. BUTCHER. STRADOLE TACK

Slot-head screws may be locked as shown

| What a Glad Surprise On Xmas Morn! A LIONEL TRAIN is a wonderful gift; it so perfectly resembles a real train. You’ve watched the long, graceful lightning express go speeding by like a rocket —engineer with tense grip on the throttle, eyes steadily ahead! Didn’t it make you eager to be master of a genuine railway system? Well, a Lionel Railway will gratify that ambition, because it looks and operates like a real electric railway.

Standard of the World for 21 Years Tell Dad you want a “Lionel” for Xmas. He'll be interested when you tell him it is so sturdily built it will last for years. Be sure it’s a LIONEL. Send for the New Xmas Catalog —showing the complete Lionel line of Locomo- tives with single motors or with twin-motors, Coaches, Freight Cars, Stations, Bridges, Sema- ores, etc., in full color—over 150 items. Then boy from your dealer or write us. Prices from $6.25 up. This train is drawn by our famous high-power TWIN-MUTUR locomotive. \|

The Lionel Multivolt Corporation, Toy Trandormer New Lionel Type ‘“‘A”” _ | | |

Soueevel by National Board ire Underwriters. Cheap- est,and best transformer made. Many improved electrical fea- tures. Electric Warning Signal 50-B, East 21st St.,. || Electrical bell rings when train New York City \ approaches crossing. at Relea ll | ut itl te tt" = tt r. p at |

fa Enjoy the worlds best MVSIC. by wireless |

. eel: ~ nearer Meer ae for receiving messages and mu-

sic by wireless.

Page 86

104 GET A HOBBY MAKE MODELS Start a Home Workshop “Model Making," by R. F. Yates, de- scribes the construction of gas-model engines, steam-engines, locomotives, boats, dynamos, turbines, railroads, guns, etc. Thirty chap- ters are devoted to models of various nature. It will help you to become a better me- chanic. It will help you to do hard soldering, soft soldering, lathe work, tempering, drilling, pattern-making, etc. This is a book every amateur or professional mechanic and model maker should have. ““Model Making" describes real engi- neering models, not toys. 400 Pages, 300 Illustrations. Practical, complete, easily understood. Price, Post- paid, $3.00. Popular Science Monthly 225 West 39th Street, New York aS ESI os x es = Sennen — 2 ee — Ay? Se eed ae Book aC apts FORMULA proce £ SSES S ‘ TWENTIETH CENTURY Book of Recipes, Formulas and Processes This book of 800 pages is the most complete Book of Recipes ever published, giving thousands of recipes for the manu- facture of valuable articles for every-day use. Hints, Helps, Practical Ideas and Secret Processes covering every branch of the useful arts are given. 10,000 Practical Formulas—The Best Way to Make Everything 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. Price $4.00 Popular Science Monthly 225 West 39th Street, New York THE HOME WORKSHOP This Weather Strip Will Adjust Itself A WEATHER strip on the bottom of the front door must close the open space entirely to exclude the cold, but when the door is swung inwardly the weather strip will strike the carpet and prevent the opening of the door. The strip shown in this illustration corrects this common defect by having narrow slots instead of screw-holes. When the strip strikes a high place it slides upward, and when the door is-closed again the strip falls by its own weight and & COILED SPRING OOR WITH grees ° iV mi “i an (get STRIP HELD BY NFOVER METAL Save coal by providing your outside door with one of these self-adjusting weather strips makes a perfect closure. Round-headed screws are used and they are turned in just far enough to permit the up-and-down movement of the metal ‘piece. An oxidized strip bent double at the top and witha piece of felt or rubber between the layers at the bottom is used. It makes a very neat and serviceable door-strip and may be used for many years. In the summer the strip is pushed up to its extreme height and held there by tightening on two of the outside screws. In the cold weather these screws are loosened and the strip again becomes a barrier to wintry blasts. Indirect Light from an Old Wash-Basin HE worker who finds need for indirect lighting in his workshop will find this a satisfactory way to secure it. First the ceiling is painted white and the inside of an Good light is necessary for doing good work and indirect lighting is superior to direct lighting old metal wash-basin is also painted white. The basin is then suspended from the ceil- ing in the manner shown. The rays of light are first reflected to the ceiling and then distributed over the room. Popular Science Monthly Learn Chemistry Dr. T. O’Conor Sloane Will Teach You No pretension of offers such alluring op r- ties. Many industrial firms pay nee chemists from $10, 15, . Sloane will teach you chemistry by a ractical, intensely interestin: Sur course is remarkably simple. B No — cial education required—if you can read and write on, Dr sloat can understand every lesso’ “deh a teaches you in your own same successful system by whieh y 42 has b already am = ti ousands in the class-ro: Pay As You Go Along The price of our course is very low and x eld the thition sncuides everything, even the Treasurer American chemistry outfit—there are no extras to Chemical Society and buy with our course. — can Day | - omell a_ Practical Commer- monthly amounts as ial chemist aswell as plan places a chemical rs: cation: within a@ noted instrucior, the reach of everyone. Big Chemistry Outfit Given FREE to Every Student We give to every student a valuable chemistry outfit which could not be duplicated for less than $25.00. This cutfit includes every- thing you need for the entire course and is given absolutely free. SPECIAL 30 DAY OFFER In addition we are making a special offer for a short time quly. You owe it to yourself to find out about it. Write for free portunities for Chemists’’ and full details of our a oath and special offer. Act today before this offer is withdraw: CHEMICAL INSTITUTE OF NEW YORK, Inc. Home Extension Division 140—S-Liberty Street New York City er oe ly easy! No musi me surprisingly o music or pate needed. * “60,000 have learned dancin Proof! method, Fort a ee. etc., send 10c toda If you can dance, learn to teach. Write reg eit ARTHUR MURRAY, Studio 43, 290 B’way,N.Y- sea WALLFLOWER? YOU Can Now Learn to Dance at home, quickly, through Arthur Murray’s invention; fascinating new ly guaranteed ? One Jessen absolutely free to eat you our eee simple 2 YEAR GUARANTEED BATTERIES SAVE 502 “Royal” Bat- u li ity ou a writ- any or gas engine. Send No Money $30, °; this ad. Battery aaa Sy express D. ou run no same for 8 years. FREE BOOKLET rr If for free WookletG Gives ret. nepal t is su or ° Get this booklet before you ery. Writet i] Give yearand modelofyourcar. ” K-E BATTERY CO., Dept. 45 14. Jackson Bvd.,Chicago Largest Exclusive Mail Order Battery House in America Semi CORD TIRES 5000 , 00 Mi I le suaraail Most modern and lastin Constructed tira. These : lng of oy bs 2 $6.90 | 2x45 $12.90 12.90 ass | sta isa0 9.10 | 35x4%4 13.90 10.20 | %x4% 14-40 10.70 | 3x5 15.10 10.95 35x5 15.10 11.70 | 37x58 18.60 END NO MONEY Bay only after examination t express offi Unwrapped soutien for inspection. if with deduct cent. Cost you nothing to ase for tire. Writetoday. Returnif notlike new. » HUDSON TIRE CORP. 391-A Harrison and Peoria Sts., CHICAGO, ILL. 106 D messlan. Sachs ‘hind?

Page 87

December, 1921

THE HOME WORKSHOP

Old Sink Forms Foundation for Gas-Stove ROM an old drain-basin with a 10-in. piece of 1-in. pipe, a 14-in. nipple of 4- in. pipe, 4%-in. elbow, 6 in. of 1%-in. pipe, and 2 plugs, I made a very serviceable stove. The legs were made of two pieces of old strap iron 2 in. wide and 24 in. long, bolted with two 14-in. stove-bolts to the back of the basin. They were bent in an L-shape, one leg 10 in, and the other 14 in. long. In each leg two \4-in. holes were drilled. The bottom of the basin had a 5-in. hole in it. This was covered with another piece of tin, an old pot-cover hammered into a

"PIPE _ 24" $ NIPPLE K-10" >} / a ELBOW ewe K a=} 12" er i 2 | ia A Basin { 2" STRAP IRON AS TUBE |_j9" This simple type of gas-stove may be made from an old drain-basin cup shape, in which a -in. hole was drilled for the 14-in. nipple that was con- nected with the 1-in. pipe. This 1-in. pipe

was tapped in the center for the 1-in. nipple. The ends were capped. On the opposite side from the )4-in. tapped hole 1/32-in. holes were drilled 1% in. apart; these were the burner holes. To assemble: the caps were screwed on to the 1-in. pipe, then the nipple was tightened into the 1-in. pipe; this was put inside of the basin. The nipple was just long enough to reach through the cup shape of tin. When the elbow was tightened it held the bi rner in place. The 6-in. pipe connected the stove by a tube with the gas-plug. I used this stove all winter with success.— L. K. LANIER. Homemade Cook-Book Holder for the Housewife

ERE is a convenience for the kitchen that is easily made. It can be made any size desired. A piece of tin is bent at one edge over a small piece of wood, just wide enough to

Your wife w'll appreciate this device for holding the cook-book support the edge of the cookbook at the bottom. Two nails driven through the tin at opposite ends hold it securely. A wire bent as shown and secured in the ends of the wood will hold the book open at any

page desired.—K. H. HuNTING.

found Guilty institution has been found guilty on two indictments: first of giving too much individual instruction and personal con- A oun mechanical training FRANK D. HENNESSY Pres. and Gen’l Mgr.

sideration ; second, convicted by its own graduates of giving two much for the money. The President of this institution has been sentenced for life at hard labor, holding down his present job as head of this wonderful school because of his proved ability to help men help themselves in these times when so many need help. He knows that there is no reason for any man with a real back-bone being out of a job. These are days of the trained man. who is properly trained should never The man be out of work. Here is Your Opportunity

—To be a Trained Man. Learn Motor Mechanics—Let ‘‘The Quality School’’ prepare you for jobs paying $200-$400 a month. Plan at once to start the new year right—in a permanent business with big, wide-open opportunities. Thou- sands of skilled motor mechanics are constantly needed in the cities, on the ferms and in the aviation fields. Here youlearn by doing everything about the care, repair and operation of auto trucks, tractors, stationary gas engines and airplane mechanics. You work with the most modern equipment and motors, including the Liberty Motor. Learn by Big Shop Standards—Thoroughly—in 7 Weeks We teach you the practical big shop methods. Our test and trouble work alone is worth the price of the entire course. No education or experience required. You work with tools—not books. Our graduates are recognized everywhere as exceptionally com- petent workmen. Thousands are holding good steady jobs or are “The Quality School” Pronounced by official inspectors, ‘tone of the best in the

making big money in their own shops. Like scholarship privileges. Special Business Course —Your choice of a thorough business training or complete instruction in Bookkeeping and Modern Shop Records and Management as part of regular course. Y.M.C.A. MEMBERSHIP. Swimming Pool, Boxing, Wrestling, Library, etc. No extracharge. BIG FREE Book tells all about the opportunities in Motor Mechanics and our big shop standards of instruction. \ Write today.

= : oe aT Ao on IT IN ae ce ee MOOD

tH NN ANN OW WN Lith) iin Qn & WWM WS q r ‘

<2 ® as oo" act apne gee qo" pas® ao” oo®

Handicraft for Handy Girls With suggestions for the girl who likes to make things. Also for the camp fire girl and the one who likes to play and work out of doors. Price, postpaid, $2.15. Popular Science Monthly, 225 West 39th Street, New York City Don’t Wear a Truss Brooks’ Appliance, the modernscientific invention, the wonderful new discovery thz 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 — together as you would a broken limb. No salves. No lies. Durable,

cheap, Sent on trial to prove it. Protected by U. S. patents, Catalog and measure blanks mailed free. d name and address today. Brooks Appliance Co., 255D State St., Marshall, Mich.

THE NEW METAL WORKER PATTERN BOOK. B G. W. Krrrrepge anv Associates. The most complete boo on metal pattern work publishes It contains 259 problems, including 65 on triangulation. 544 pp., ong. Price $7.50 Pop ilar Science Monthly, 258 W. 39th St., New York POOL AND BILLIARDS Learn to become an expert player through scien- tific methods used by champions and ex-cham- pions. Thorough course to study at home. Write for information. PROGRESSIVE EXTENSION INSTITUTE 1174 Phelan Bldg., San Francisco, Calif.

You Can Save *50.00 By recovering your old suto top frame yourself.

We make these recovers to fit $5 75 all makes and models of cars. e Any person that can drivea and u car can putiton. We furnish .y instructions. Roof and quar- Parcels Post Paid ters sewed together with rear curtain, fasteners, welts and s. All complete. Give us the name, year and model number of your car we will send you our ith les and quote you ex: pri wi ice. LIBERTY TOP & TIRE CO. Dept. E8, Cincinnati, O.

Tipnssanthae 1007 -2rm

Page 88

once rmerctir or 8 sant nm arene ages Ds aS ¥ SS a SY RR

LEARN MUSIC

Play by Note Piano, Organ, Violin, Cor- net, Guitar, Banjo, Man- @ dolin, Harp, ’Cello, Trom- Music no longer diffi- ne, Flute, cult! New plan makes it Clarinet, Pic- easy to learn by home colo, axo- study. Positively easier phone, Uku- than with private teach- jele, Sig AN - er. Faster progress. You ae St a will be able to play your “se a + rene favorite instrument in one peas a few short months! mack, New Ticsinieubthaen More than 250,000 *P in a here’ Tener Banjo, men, women and chil- yo “4 your Drum&Traps, dren have learned by wonderful = etc. our method. You, too, jem. one net can learn in your spare from another

time. Amazing Offer We want to have one pupil in each locality at once to help ad- vertise our home study method. ‘or a short time, therefore, we offer our marvelous lessons at practically no cost, charging a sum amounting merely to about the cost of sheet music, Beginners or advanced po apils. Write for amazing free book giving all 1 SE particulars. Send 8 ecmente supplied when needed, cash or credit. U.S. School of Music 812 Brunswick Bldg. New York City a EAT YOURSELF <4 composing music.

Learn how Violet Ray ve geen enriches impoverished blood, lieves nervousness and builds vital strength. Drives out aches and pains and removes the cause. Speeds up digestive process, promotes assim- ilation of food and elimination of waste products. 4 Absolutely shockless and safe. You spray thou-“ sands of volts of high frequency electricity yey weak, inactiv entire body “a, land flooding i it aoe Dem h, f ih, str enti iid ic resi 8 \- lood. ny by physicians--35,000 in tr - _fer the =i nal Tells Sent t. Get “HEALTH ” Book Ss s the whole story of the Au tA cesses, man these wonderful, conestins forces of mature, Write ok once. .. on RENULIFE aes COMPANY 1812Marquette B' Detroit, Mich. —— Netting Bids, Windsor, Ontarie Sor attractive plan

Renufite hire WIOLET RAY GENERATOR

“Seger Only $45.00 For This Job Complete Seve exorbitant freight rates and one-half

board, uphois' ring. me wood parts, bolt sc: etc. Fiat radiator shell prowmed made, a Designed low with | lack of ind resistance. Price "Partner ther particulars wi a! on request. The Central Aute Supply te. “Ee. Dept. 122 Louisville, Ky. Play the Hawaiian Guitar -Just Like the Aawaiians!- Our method of teaching is so simple, plain and easy that you begin on a piece with your first les- son. In half an hour you can play it! We have re- duced the necessary motions you learn to only four —and you acquire these inafew minutes. Thenit is only a matter of practice to acquire the weird, fascinating tremolos, stacca- tos, slurs and other effects that make this instrument so delightful. The Ha- waiian Guitar plays any kind of music, both the melody and the accompani- ment. Our complete, course of 52 lessons includes FREE a beautiful Hawaiian Guitar, all the neces- f sary picks and steel bar and 52 ‘ pieces of music. Special é arrangement for lessons if you have your own guitar. ‘*This Makes a Splen- 2 did Christmas Gift’’ Send Coupon NOW = 3% IA Get Full Particulars FREE ! First Hawaiian Conservatory of Music, Inc. I I 233 Broadway (Woolworth Bldg.), New York City l | L

| I am interested inthe HAWAIIAN GUITAR. Pleas send complete information, special price offer, etc. etc gp NAME....0... 0.0. sees eeeec eee ee eee eeeeneeees i Biri 00 ip semmcnhens nse nne en teblnaeaane l I tTown........ COUNTY....... STATE..........- ; ? Print name and address clearly. 12 P.S.M. THE HOME WORKSHOP

Some Uses for Picture-Hooks for Hanging Pictures ee brass picture-hooks can be put to a variety of uses for which, ordinarily, special strips must be cut. If they are hammered out flat and then punched for round-headed screws, they make fine ornamental strips for putting on homemade furniture. They can be flattened and bent at right

— BRACKET FOR TOOLS KITCHEN. UTENSILS, CLOTHES CLOSET, ETC.

ANGLE- BINDING PICTURE-HOOK FOR BOXES

Picture hooks may be bent in va- rious ways to adapt them to other uses angles and used as angle bindings for boxes or cabinets. They may also be partially straightened out and used as brackets for supporting such tools as braces, hand drills, drawing- knives, etc. In the kitchen, when screwed to the wall, they make excellent supports on which to hang kettles, dishpans, or other utensils. If tacked around the walls of closets, articles of clothing may be hung upon them. Other uses will naturally suggest themselves.—L. H. KIRBY.

Shutter-Frames Can Be Used for Window-Screens EEDING some screens for the windows I brought from the cellar some old shutters. Selecting those that fitted the windows I wished to screen, I removed the slats by sawing them on one end. They then

Practical window-screens may be made from old shutter-frames dropped out, leaving a good strong frame. Over these frames I tacked screen wire. After painting them, I put them on the windows. The hinges and catches were still in place. The screens were very satis- | factory, as they could be thrown open, al- lowing one to shake dusters, etc.—MRs.

H. E. Houp.

I le ta cmaenel

108

Popular Science Monthly

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Reduced Prices and THREE YEARS TO PAY for this beautiful MEISTER PIANO Set exquisite styles to choose from and the one you select will besent you on 30DAYS FREE TRIAL—ALL FREIGHT PREPAID A guaranteed of $100 to $150. If you like the piano we will sell it to you on small monthly payments to — our convenience as low as $8.00 per month. No cash deposit asked. No interest sey pod any! kind. | free with

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High Frequency Apparatus By T. S. CURTIS This book covers the design, construc- tions and practical application of all kinds of high frequency apparatus for use in experimental, medical and plant cultivation work, and also includes directions for the construction of a complete stage outfit for both low and high potential work, 266 pp., illus. Price, $3.00 POPULAR SCIENCE MONTHLY 235 West 39th Street, New York City COMICS, CARTOONS, COMMERCIAL,

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December 1921 THE HOME WORKSHOP Ornaments of Hammered Brass Are Welcome Gifts RNAMENTS of hammered brass are very effective for decorating book- ends, desk sets, pipe-racks, etc., and the only tools required for making them are an old pair of scissors, a round-headed hammer, a gouge and some blocks of hard wood. Draw some circles and ovals on the end grain of the wooden blocks and with the gouge work them out into smooth de- pressions of any desired depth. Make a PATTERN CENTER HAMMERED EDGE TURNED AND ORNAMENT CUT OUT TO SHAPE Beats ¢ ow WOOD BLOCK CORNER FOR SHAPING CENTER Handsome ornaments of hammered brass may be made with simple tools pattern of the proposed ornament on paper, cut this out, lay it flat on some sheet brass 1/32 in. thick, and mark around it with a lead-pencil. The brass is then cut .out with the scissors. Suppose you use the quatrefoil design illustrated. First place it carefully cen- tered over a circular depression in the block and beat it gently with the head of the hammer until the brass bulges and fits the hollow. Next hold the brass with the bulge upward so that the edge projects over a rounded corner of the wood and tap itso as to bend therim. Keep turning until the entire edge is rounded over. Then punch the brad- or screw-holes and the ornament -is complete. Polish with fine sandpaper or emery.—L. H. KIRBY. How to Improvise a Slide- Easy Collar BD paphlsieeacrantg starched collars are quickly converted into slide-easy collars by putting a pipe-cleaner well up into the crotch of them, as shown in the illustration. The tiny bristles prevent the cleaner from working down while the collar is worn, and the tie will slide through it easily, without requiring any effort.—A. SCHAAL. PIPE-CLEANER—) COLLAR A hint for those who wear turn- down collars is wonderful new method makes it possible 107 for anyone to learn Illustrating, Cartooning, or Commercial Art. making splendid incomes. Hundreds of our students are now And most of them never touched a drawing pencil before they studied with us. The simplicity of this method will astound you. You will be amazed at your own rapid progress. You learn by mail—yet you receive personal instruc- tion from one of America’s foremost Commercial Artists—Will H. Chandlee. Get into this fascinating game NOW. You can easily qualify. A few minutes’ study each day is all that is needed. Crying Demand for Trained Artists Newspapers, advertising agencies, magazines, business concerns —all are looking for men and women to handle their art work. There are hundreds of vacancies right this minute! A trained commercial artist can command almost any salary he wants. Cartoonists and designers are at a premium. Dozens of our students started work at a high salary. Many earn more than the cost of the course while they are learning! YOU—with a little spare-time study in your own home—can easily and quickly get one of these big-paying artists’ jobs. No Talent Needed This amazing method has exploded the old idea that talent is an absolute necessity in art. Just as you have learned to write, this new method teaches you to draw. Westart you with straight lines, then curves. Then you Modern American Telephony in All Its Branches By A. B. SMITH A thoroughly practical, comprehensive treatise, including descriptions of apparatus, line construction, exchange opera- tion, construction of underground conduits, cables, aerial lines, sub-stations, switch-boards and the central office. 800 pp., 600 illustrations. Price, $2.00 Popular Science Monthly, 225 W. 39th St., New York $4 or $5 witBury A Standard, Guaranteed TYPEWRITER ss With Every Modern Writing Convenience Write Today For Mlustrated Circular Explaining Try-Before-You-Buy Plan SMITH TYPEWRITER SALES CO. (Harry A. Smith) 306-218 No, Wells St..Chicago, 1" m pebliclt $5,000 to $10,000 azeur 8 you can earn. improved system guides you step by step until you have the bar examination in ig money re- errining incleding’ souplese c. ~ comp! learn how to put them together. Now you begin making pictures. Shading, action, perspective, and all the rest fol- low in their right order, until you are making pictures that bring you from $50 to $500 or more! Many artists get as high as $1,000 for a single drawing! Write for Interesting Free Book Mail coupon now for this interesting free book ‘‘How to Become an Artist.”’ Explains about this amazing method in detail. Tells of our students—and their wonderful progress—and how we can qualify you for a high-salaried artist's position. Also tells of our free artist’s outfit and special low offer to a limited number of new students. MAIL COUPON NOW! Washington School of Art Room 1708, Marden Building, Washington, D. C. --—--FREE COUPON —--— I WASHINGTON SCHOOL OF ART T Room 1708, Marden Bldg., Washington, D.C. Please send me, without cost or obligation on my l part, your free book, ‘‘How to Become an Artist.” (oT) Se ee Coe ee tr ee ree * Please state whether Mr., Mrs. or Miss. OO Ee Re ee ae pT Pe Ee cee ite iaciaieadanabieniiaeieiaeaniiiiel eal aadieeeeniaaaadl 1 $0175 ad bo For your home or business; for wash- ing and ironing machines, garage or ma- chine shops, house pumps, printing machin- ery,etc. A general utility motor for many purposes. Thoroughly tested, high quality, moderate price. Quality Motor Bargain Columbia Motor—for A. C., 4h. p., Ip., 25, 40, 50 or 60 c., 110 v., 1750 R. P. 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108 Popular Science Monthly How the Man in Maine Buys Oregon Apples RY Comers lives through the inter- change of products. California fruits are sold in Maine. Shoes made in New England are worn on the Pacific slope. Automobiles from Detroit traverse the Florida sands; the North Smokes Southern tobacco. And so it goes. Advertising has played an all important part in fostering business growth. With- out it we would retrograde half a century, or more. Business would stagnate; large institutions which build cheaply by large production would fade into oblivion; we would live in total ignorance of many things which might add to our wealth, health and happiness. The bread and butter of business depend on advertising, and your interest in it. Read the advertisements. They will be as productive of results to you as to the companies that pay for them. In half an hour, or less, you can learn much of many things that go to make life what it is. Read the advertising. It enables you to get more for your money by telling you what to buy. It is your guide to -what’s good to get. Read it — reflect on it — it pays —__, ‘THE HOME WORKSHOP Wide-Swinging Gate for the Farmyard A GATE that may be swung through nearly 360 degrees may be made by using an offset ring-hinge such as is shown in the illustration. The line of the gate is on the opposite side of the post from the line of the fence, and this construction allows of swinging the gate back against the fence on either side, which is often very SUPPORTING RING When swung open as far as it will go, this gate — be flat against the ence desirable. The mounting below the lower hinge should be a solid ring, to allow of free rotation of the hinge upon it. The post used for a hinge-post should, of course, be round. The post on the other side of the gate should be so placed as to allow the gate to pass it if the maximum swing of the gate is desired.— LOUIS SCHNEIDER. Novel Spool- and Twine-Holders and How to Make Them HE spool-rack in the picture is made from a straight stick of macaroni and a pair of long hatpins. When necessary to put on a new spool, simply pull out one of Po] 10 togentou Uy I YE f / / | : WN th 5 gata ree ALA WA CAEN ti WAN My \ i eu the pins. It’s so convenient to have all of | - | | your spools right at hand when sewing. | The other picture shows a single-spool | holder made from one of the handles the | grocer gives away for carrying parcels home. Keep some of them, for they make the handiest twine-holders. Always have one in a convenient place in the kitchen and laundry.—JENNIE E. McCoy. tien D

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aie December, 1921 DIAMOND and other Jewelry ON CREDIT These 14K. solid gold sled with wiste’ gold prongs are set with superior quality blue-white, perfect cut diamonds unexcelled in quality. Beautiful hand-engraved white gold mounting set with superior = quality blue- : , white .diamond. att $50. on ue- White wold Shank ae "aiamie is Friendship ring N set in Platinum, Set, with 5 dlue- forming solitaire white diamonis. cluster ...$48.50 135.00 "= ring. one supe- N7 — vnla ue rior diamond. $45.00 Ng— Platinum top, 1¢ a gold inverted green gold ring hearts are set with one supe- rior - blue-white diamond. . .$50.00 with one superior quality —— diamond. . .$75.00 10—‘‘Sweetheart”’ Plati- BUY 10 TODAY * he ag MONTHS and carved and pierced synonymous wae he T0 PAY Beautiful Xen Xmas Gifts On Credit—at Cash Prices Blue white, perfectly cut diamonds, handsome watches, dainty toilet articles. Your choice ON APPROVAL. _ If satisfied after examina- tion, pay only 1-5 the price—balance in ten monthly payments. ABSOLUTELY NO RISK, Send for FREE De Luxe Christmas Catalog Thousands of exquisite designs to choose from— every article a Rare Bargain. ‘‘Satisfaction guar- anteed or your money back."’ Ten Months to pa oneverything. Write today. Address Dept. 471- Capital $1,000,000 “THE HOUSE OF QUALITY” LW-SWEET INC. 1650 -1660 BROADWAY, NEW YORK Books for Mechanics Sheet Metal Work—A manual of practical self-instruction in the art of pattern drafting and construction work in light and heavy- gauge metal, including skylights and roofing, cornice work, etc. Cloth, 288 pages, 370 illustrations. Price, $2.60, Postpaid. Machine Shop Work—A comprehensive guide to the most approved methodsin modern shop practice, the construction and use of im- proved tools and machines, hand tools, the lathe and lathe tools, the methods of screw cutting, taper and eccentric turning, etc. Leather, 360 pages, 401 illustrations. Price, $2.60, Postpaid. POPULAR SCIENCE MONTHLY 225 West 39th Street, New York THE HOME WORKSHOP Spinet is Transformed into Bookcase and Desk NE day, while rummaging in the attic, I conceived the idea of transforming an old spinet stored there into a useful piece of combination furniture. The spinet was of mahogany, standing 40 in. high. It was 414 ft. in length, and 3 ft. 9 in. at its widest point. The first thing I did was to remove the keyboard and the mechanism in the interior of the instru- What was done with an old spinet may suggest similar transformation of other old furniture ment. Next I built into the fore part of the old spinet two sets of small drawers on each side and partitioned off a number of pigeon- holes of various sizes. Then the affixing of a hinged writing surface supported by two metal quadrants gave to the front of the former instrument the ordinary appearance of a comfortable writing-desk. Further- more, by means of a pair of movable sup- ports, I made the music-stand adjustable so that it could be lowered to serve as a con- venient bookrest or raised to act as a lid for the desk by folding over flush with the top. The music-stand and writing surface met at right angles when closed, forming a firm protective covering and changing the article into a quaint library table. I divided the rear portion of the body of the former spinet into three parts for the storing of books. The volumes were put in with titles uppermost. In addition, I fashioned a large drawer to be used for keeping papers, booklets, and the like in each side of the desk in such a way that they were wholly unseen. These drawers were opened by clutching them with the hand on the under side. To open the combination bookcase, library table, bookrest, and desk, finally, one had but to touch a pedal of the former spinet, which released the catches holding the music-stand and writing surface in posi- tion.—L. C. GOBETz. A Convenient Ruler that Does Not Slip ‘Tas ruler consists merely of a length of angle-brass with 14-in. flanges. Select a smooth piece and finish the ends neatly and the job is done. If you wish, you may mark an inch-scale on it. Use the ruler with the corner up. It gives a hold for the hand better than any except the triangular ruler, and it has the advantage be- cause it will not slip. For this last reason it is very useful for cutting ANGLE BRASS where considerable pressure must be used. — HOWARD A suggestion for GREENE. the drafting-room need to answer your many questions—to solve your knotty problems, to teach you new kinks to be your memory for tables, rules, formule, an other Electrical and Mechanical facts. With this “Little Giant” I.C.S. Electrical Engineer’s Handbook within easy reach, an hour or a day need not be lost “digging up” some unfamiliar fact; you'll just turn to the index and get it “in a jiffy.” A few of the subjects treated are: Electricity and Magnetism; Batteries; Cir- cuits; Magnets; Direct and Alternating Currents; Dynamos and Motors; Belts; Shafting; Electroplating; Electrical Mea- surements; Meters; Arc and Incandescent Lamps; Mercury-Arc Rectifiers; Trans- formers; Insulation; Electric Cars; Single and Multiple Unit Control; Transmission; Rail Welding; Tables of Wires—Sizes, Capacities, etc.; Mathematical Rules, For- mule, Symbols; Tables of Constants, Equivalents, Roots, Powers, Reciprocals, Areas, Weights and Measures; Chemistry; Properties of Metals; Principles of Me- chanics. This Electrical Engineer’s Handbook is just one of 22 I. C. S. Handbooks covering 22 Technical, Scien- tific and Commercial subjects, all equally crowded with value. They have the contents of full-size books condensed into pocket size, ready to go with you anywhere and be at your instant command. You run no risk! Money back if desired! ae eee ee ee ae TEAR OUT HERE — — — — — — INTERNATIONAL CORRESPONDENCE SCHOOLS Box 7659-B, Scranton, Penna. I enclose $____ for which send me, postpaid, the Handbooks marked X, at $1.00 each. It is understood that if I am not entirely satisfied I may return any or all of them within five days and get my money back. Hie just the book on Electricity tha: you ELECTRICITY r’s Westinghouse Air-Brake Steno.’s and Correspoendent's Civil Engineer’s usiness Man's Mechanic’s Advertiser’s Steam Engineer’s Salesman’s Concrete Engineer’s Window Trimmer’s Teleph. and Teleg. Engineer's Cotton Textile Worker's Building Trades Mariner’s Plumber's and Fitter’s Farmer’s Coal Miner’s Poultryman’s Chemist’s Automobiles Name Street Address. State. ; “Mee” C Closter Metal Shingle. 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anced eens vara a “hog epee Seite at ee =p Seto orn peer nent ah rs: my on rege eye se mean 9 egos tana on Be Se a eorpereoveeriaities wee ee jo ese a > heer ea Satake aes wo are mamenelynnte wan THOME “ine ne. AC 25Cal. regula-\h tion blue steel |ik AUTOMATIC tia REVOLVER LS e Regular Pric?2250 OUR PRICE While they last evertaeviine g Keep one of these safety revolvers in your home and be fully protected against bur- glars, thieves and hold-up men. It’s a terrible fright to wake up in the night—hear noises down stairs or in the next room—and realize your neglect has left you wholly UNPROTECTED. Buy one of these revolvers and,be always fully protected. Handsome blue steel, gunmetal finish, HAS DOUBLE SAFETY and is prac- tically ‘‘foel-proof”’ against accidents. Perfect grip, accurate aim. Rifled barrel, checkered grips, safety lever. Holds 7 cartridges. Small, compact, lies flat and will not bulge out pocket. Shoots the famous Colt Auto Cartridges. SEND NO MONEY Order to-day. Just send your name and address and say which revolver you want. No. 345 is 25 calibre, 7 shot. Reg- $975 ular price $22.50. Our price........ No. 745 is larger size, 32 calibre, mili- tary model. 10 shot, extra magazine $ (worth $1.50) FREE. Regwier price $25.00. Our special price, only. .... Don't wait. Order this bargain today. Write clearly your name, address and the Number of the Revolver you want to order. Send no cash. We ship by return mail. Pay Postman on arrival, our price, plus postage. Send for free catalogue. Paramount Trading Co. 34 West 28th St., New York City e and we will you a SAMPLE COLLAR cf our New State size wanted. REVERSIBLE COLLAR CO., ous Learn in Spare Time to be a CIVIL ENGINEER Earn $1500 to $5000 Yearly Here's your big chance to be- come a full —. Civil Engineer! With this set of books you can fit yourself to make big money, in the greatest outdoor profession on earth! Offer fully explained in coupon. Good only within bound. aries oa the U. S. and Canada. 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I will send $2.80 within seven days and $3.00 a month until I have -80 or return books at your expense. eee eee eee eee eee eee ee eee eee ee THE HOME WORKSHOP Receiving Rain Warning by Telephone OMETIMES it is important to know when rain begins to fall in the night. One method of obtaining this informa- tion is to use a discarded telephone trans- mitter. Fastenthe mouth-piece, mouth up to the roof or any con- venient place open to the sky, and over it fix by the corners a sheet of tinned iron in con- tact with it. Then lead the wires to your bedside, where you will have the dry cells and the receiver part. The rain striking the tin will make a lot of noise which you will hear in bed.—E. A. McCANN. F\TIN COVER TELEPHONE TRANSMITTER ON ROOF RECEIVE OVER BE! BATTERY The telephone will enable you to hear the rain falling Here’s an Ingenious Screw- Holder for Starting Screws T is sometimes necessary to start screws in a place that cannot be reached with the fingers. When such a condition is met with, the tool shown in the illustration will prove very handy. A piece of 14-in. rod is used for the handle and slotted-for a distance of about 1 in. at . one end by sawing. An old alarm-clock HANDLE CAN BE ANY LENGTH How to start screws in otherwise inaccessible places CLOCK SPRING SLIT spring furnishes the material for the fingers of the holder. A piece of this is doubled in the middle and forced into the slot in the handle. The fingers are shaped as shown and the ends squared by filing. To use the holder the fingers are pressed together and slipped into the slot in the screw. After the screw is started, the holder is pulled away from the screw. One Method of Removing an Obstinate Staple [oe staples that are driven in deep or rusted in place are often hard to extract. This can be done easily, however, with the aid of a claw-hammer. Run a big nail through the staple and hook the claws of the hammer under the nail, the claws straddling the sta- ple. Puta piece of wood under the hammer so that the surface will not be damaged, and then pull in the usual way. A very small ‘ staple, or double- pointed.tack, can be re pulled in the same aie cies in seat way with the claw 112 ing end of a hammer. Popular Science M — Don’t guess about so vital a matter as your health. Keep a Tycos Fever Thermometer in the home. One of many Thermometers—bath, candy, wall, oven, etc. — made for home use by world’s largest makers of temperature instruments. At repre- sentative dealers, Health Booklet Free | Lalor [Instrument Companies ROCHESTER, N. Y. There’s @ Gees or Wér Temperature Instrument for ated * m0 “BOWLEGS andKNOCK-KNEES” UNSIGHTLY 4 SEND FOR BOOKLET SHOWING PHOTOS OF MEN WITH AND WITHOUT The Perfect Leg Forms PERFECT SALES CO.,140 N.Mayfield Ave., Dept. 45, Chicago, Ill. FREE RAL Cr out out this ad and Mail it to us, with your name and no money) ; and we will send you our FAMOUS KARNA RAZOR by return mail, postpaid. 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December, 1921 The Last Discoverers (Concluded from page 25) plorer. The man who travels to the ends of the earth to-day is led by the hope of a discovery that will prove of lasting value to mankind. For example, coal has been discovered in the region of equatorial Africa to which Carl Akeley sailed last August. This is the first good coal found in Africa. There are small lignite deposits farther south, but the lack of a suitable smelting coal has forced African miners in this region to float copper and zine ore down the rivers to the coast and to ship this unnecessary bulk of ore across the sea for reduction. Now, in an area of which very little was known, we have found a ¢oal-mine which will do much to make this section of Africa a great pro- ducer of metal. A parallel case exists in British Guiana. The streams here have some gold in their sands, and occasionally placer-miners find a diamond. But where are the diamond ‘pipes’? An expedition has left the Smith- sonian to look for mines, and its leader, W. J. Lavarre, expects to remain in the jungles until he succeeds in this quest. Geographical explorations such as Shac- kleton’s and Colonel Bury’s expeditions to Mount Everest, is drawing to’a close. They have become a matter of clearing up de- tails rather than preliminary surveys of totally unknown regions. The era of com- mercial exploration, such as the expedi- tion of Lavarre and the oil prospecting on the Mackenzie have only begun, and in the future we can expect more and more work of this character. For instance, a few of the expeditions in the field to-day for scientific objects are the following: Dr. C. D. Walcott in the Canadian Rockies, Mr. L. H. Abbott in Chile, Dr. H. L. Shantz in Africa, and Mr. C. M. Hoy in Australia. The majority of modern ex- ploration is purely scientific, but it must not be supposed that this “‘pure science”’ has no interest for the average man. It might. seem as if the discovery of ten new varieties of beetle in South America, is a matter of little practicalimportance. But results which are at first ‘‘purely scientific”’ soon turn out to be of immense practical importance. Dr. Henry Rusby is now in the Amazon valley in search of rare plants —and to study noxious insects. Among the plants he expects to find medicinal remedies unknown to our present phar- macop‘eia, perhaps a medicine of such tre- mendous importance as quinine, which was brought back from these same forests by the early Spanish explorers. The study of insects may lead to the discovery of new serums for the treatment of dysentery and lockjaw, or the blotting out of tropical dis- eases, as his colleagues discovered the causes and the cure of sleeping sickness. Few of us realize that modern research is like a pyramid—we hear of the peak, the culminating fact, that is recorded in the daily papers, but this is based on a long series of observations and data gathered by men scattered to the ends of the earth, working laboriously and unknown to fame in tropical jungles and frozen wastes. A scientific discovery is a synthesis of appar- ently unrelated facts gathered by many men, and these modern explorers at work at the points indicated on our map are really the advanced outposts of the army of science, and if the age of exploration for its own sake is drawing to a close, that of exploration for the sake of humanity has only begun. lil GIVE Popular Science Monthly for Christmas A SPECIAL HOLIDAY PRICE TO OUR READERS An ideal Christmas Present will be a subscription to Popular Science Monthly. You will give fresh, fascinating, vital reading for a whole year. Popular Science Monthly is packed full of useful facts, new ideas and practical information. Give some friend the pleasure of having this good magazine, which is growing better every month. We make you a special Christmas rate of $2.50 for a year’s subscrip- tion. This special rate is open to every reader. $2.50 the Christmas Rate on Popular Science Monthly You may give one or more subscriptions at this special rate. You also may include your own subscription. Use the order blank below. If more convenient, you may remit after January 1st, but send your order now. This offer expires December 25th. Every Month Next Year All These Things in Popular Science Monthly What Do.You Want to Know? Popular Science Monthly will answer your questions free of cost. Your Automobile Latest facts on economy of upkeep —repairs—tires — motor — gas— oil — Useful Things to Do at Home batteries— garage —new accessories, First aid hints for keeping things shipshape about the house. New Inventions New tools, new labor-saving devices, Every-Day Wonders wonderful new machines—hundreds in Ten fascinating facts of science ex- | every issue. plained in every issue. Things to Make with Tools Flying Over 50 new designs every month| Watch this marvelous science grow which every reader can make at home. | month by month. Send Christmas Order Blank Now POPULAR SCIENCE MONTHLY, 225 West 39th Street, New York Enter subscription for Popular Science Monthly for 1922 for the name below. Please send Gift Card Announcement. Send to ~ Ordered by Coe eee errr eereseeeseeseseeseeesese ij j= §§ = «see #8 ee eeeesseseseseseseesessee ee war rece cece ce scceeeeroroeseseosoes Ce © | ‘a Check here if you wish to include your own subscription - You may write order on blank paper if you prefer Remittance Pl d Amount $ herewith C] i .

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Guaranteed Genuine Leather Secret Pocket solutely FREE 30c, Fraternal Embiems 40c Extra) gives the pocketbook an ex- peril seton s for over 16 years. You take no risk! (SECCSS SSCS ERERESES SESE ESESeeeEEEs U. S. Leather Send me your e Genuine pocketbook. When it price of onl: checked below. tbook and Popular Science Monthly Stars of Popular Music ie PAUL WHITEMAN PAUL BIESE ISHAM JONES Play the Conn What greater proof of superiority than the fact that these artists and their orchestras all use Conn in- struments? Yet these are only a few of those who, pomente and through phonograph records, are thrilling millions with the brilliant beauty of their music. You, too, can win popularity, double your income, plaving whole or part time in band or orchestra. Take a tip from the world’s great- est artists; playa Conn, Exclusive processes make them easiest of ali to master. Free Trial; Easy Payments All exclusive Conn features at no greater cost. High- est honors at world ex- positions: Used in great concert and sym- phony organizations. FREE BOOK “Suc- cess in Music and How to Win It” by Sousa and nine others. pond coupon or your copy ‘and details of #2 Wy (freetrial offer. @ eq Gom lee 1232 Conn Bldg. Elkhart Ind. Agencies in all large W.4T® Se. - BURUERR RRR SRRRRERSRR ERS RERERR RET REE AES C.G. Conn Ltd., 1232 Conn Bidg., Elkhart, Ind. Gentlemen: Pléase send my copy of “Success in Music” and details of your tree trial plan. (Mention Instrument.) Name St. or Rural Route City, State THE HOME WORKSHOP Hinged Tailboard with an Eccentric Lock 7 you are handy with tools, you can con- struct a hinged folding tailboard with an eccentric lock such as the one shown in the illustration. The lock is cut CLEAT HINGED JOINT TAI a = | Hn > \ Mh ES —Y i] A BZ ee —_ eS — I THI ND SCREWED TAIL OF ECCENTRIC Hoan Se AG HALF OF TAILBOARD Interesting suggestion for a hinged tailboard with an eccentric lock from a piece of flat iron stock, the lower end (or tail) being bent slightly outward to provide a handle. The locked position of the eccentric is shown, the weight of the tail portion normally holding it so. When the tail is turned straight up, the catch of the lock is released, and the tailboard can then be removed.—LOUIS SCHNEIDER. Hallstand Is Built from an Old Oak Easel A*™ antique oak easel that had stood in the attic for a long time, was trans- formed into a hallstand as illustrated. The stick at the back that-supported-the easel was cut into lengths for the umbrella- rack, together with the strip on which the \ EASEL } ~~ ~UMBRELLA-STAND This illustrates the transformation of an antique easel into a modern and useful halistand picture rested, the scalloped portion of which made edges for the bottom of the rack, which was the only new piece of wood required, and was stained with a dark oak finish to match the rest. Six ornamental brass hooks were added, and the result was a good-looking and useful article of furni- ture.—KATHERINE L. DANIHER. Try a Coal ‘‘Carburetor’”’ on Your Range ‘TS object of the device is to save coal, which it does by mixing the gases created in combustion with air and burning them, instead of permitting them to go to waste up the chimney. Manufacturers of several patented “‘car- buretors’”’ claim a saving of at least 20 per cent in the amount of coal used, besides ‘ the fire.—E. B. DEIsT. complete combustion, giving a uniform heat, and burning the coal to a fine white ash without clinkers. The one shown in the illustration has been thoroughly tested by several months’ use on a kitchen range, and has given ex- ceptionally good results. To make one, all that is needed is an old grease-cup (iron or pressed steel) from an automobile, such as is used on the Ford universal joint, two small drills, and a 14-in. pipe-tap. Drill a hole in the center of the stove-lid and tap a 14-in. pipe-thread in it. Take STOVE- CARBURETOR AIR-HOLES IN CAP Try this coal-‘‘carburetor’’ on your range and you will find that it saves coal the top of the grease-cup and with a very small drill (1/60) drill, evenly distributed, about a dozen holes in it. Screw the cup together, and then screw it into the tapped hole in the stove-lid. Your “carburetor” is now complete, and ready to work; hanging inverted over the fire. Even better results can be achieved by attaching a carburetor to each lid that is directly over Correct Drawing May Cause Error in Machining WING to the manner in which a cir- cular drilled hole was shown on a detail drawing, as being cut through a circular bar, a machinist was misled to the extent of turning out a piece with a cir- cular groove around the bar instead of the required hole. While the method of depicting a hole in the bar is corréct as shown in the illustration, in accordance with mechanical drawing practice, also the dimension for the diameter of the hole, these details will invariably mislead the mechanic if he does not underst and the projection. A method for the draftsman that in- volves less work and is clearer to the ma- —— 2470 — I’o 3 i PART AS SHOWN ( ' ON DRAWING ee, baa Oe Ee ak PART AS TURNED OUT BY MACHINIST ] rth f HOLE DRAWN AS re. title SHOWN, INVOLVES ” Trt + LESS TIME AND 15 | +14 CLEARER FOR MACHINIST -1- a a 6 ke Draftsmen can learn from this illus- tration how to make their drawings so that they cannot be misread chinist is to leave off the circular lines at the ends of the holes. As a time-saver and for clearness, this is worth adopt- ing.—G. A. LUERs. m-_ a) i ie ee i aT ok 6

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December, 1921 THE HOME WORKSHOP How to Obtain Reflected Light for Indoor Pictures T= amateur: photographer finds that taking interior pictures by daylight is not usually a success. The ordinary living-room. does not furnish sufficient light for photographic purposes, even when a time exposure is used. The only method is to place the subject close to a window so as to get the full benefit of the light. How- ever, this always results in having one side PATH OF LIGHT RAYS 7 { an °F CAMERA [f3: SUBJECT. £E cone MIRROR Amateur photographers will be able to take an indoor portrait by the use of this simple arrangement | of the object illuminated, while the other | side will be in the shade. This difficulty of | proper lighting has caused many a camera lover to avoid indoor pictures. By the use of a mirror properly placed, some of the light coming from the window may be reflected to illuminate the shaded | side and thus help to procure more even | lighting and avoid the defect of heavy shades and shadows. An ordinary sized _ hanging mirror so used will give surpris- | ingly good results. A large piece of white paper with a glazed surface will make a good substitute for the mirror. The picture and inset diagram show the | arrangement. The best location and angle of the mirror can easily be determined by trial.—B. Fox. Another Winter Use for an Electric Fan N electric fan need not be stored away in the wintertime, as it can be put in service in the way shown in the picture. It is connected with the cellar light-socket a | Li ; i | Yi ee \X | ‘all “—-, 2 mM nl We A 1) MU The electric fan forces cold air into the furnace, thereby aiding fuel combustion and placed so that it will blow air into the cold-air pipe. This assists the circulation of cold air through the furnace, aids the combustion, and increases its heating efficiency.— JOSEPH B. MORAN. MMMM MMO OO TOT OOOO COCO MMMM UC New | | |= has a message for you. F you want to get something that will keep you busy and fascinated all the time; that will show you the wonders of chemical science; that will start you off on one of the most interesting things you ever did; that will give you reliable and practical information on the most absorbing science there is to-day—if you want REAL fun with a live bunch of fellows—then I say to you, get a CHEMCRAFT outfit and start experimenting on your own hook!” “With a CHEMCRAFT outfit you can work all kinds of amusing and instructive chemical experiments. You can test the things you eat, wear, and use every day; make soap, dyes, inks, and do many other practical and useful experiments that will be more fun than anything you ever did, and give you an understanding of chemical science. Yes, you can do fine tricks, too, the kind that make everybody wonder how you dothem. Chemical experimenting is the finest sport I ever had. Everybody says my “lab” is a dandy, and it started with a CHEMCRAFT outfit. When I got my outfit I joined the Chemcraft Chemist Club and started my own Local Chapter under the “Pine Tree’? name. Now I’ve got a live Club and I’ll soon have a real business, too. I'll tell everybody that the best thing I ever did was to get my CHEMCRAFT outfit—and I advise every boy to get one right away.’ EM iC Fl MC! O Makes Any Boy an Ammatenn Chemist! You can do what Harry has done. A CHEMCRAFT outfit is your introduction to the ‘‘wonders of chemical science’’, as Harry says. Plan now to get your outfit this Christmas. Then you can join the Club; be the Chief Chemist of your own Local Chapter, and get other boys in with you. You'll get the Club magazine, too, and can exchange letters and experiments with other Club — Special Note to ra, members. Put CHEM- __ Uneles; Big Brothers and ‘Tho Qparacter Anahysss Game oe me the es of your all Good Friends! . Makes Character Reading ristmas list and te every- ~~~ Easy and Interesting for °4Y that’s what you want! your favorite = Children and Adults Select from These ¢CHEMCESET omit Based on the celebrated character analysis science of Dr. Katherine M. H. Black- ford and is correct in prin- ciple. Outfit contains eye, nose, mouth, chin, forehead and head sections: both pro- file and front views; with which thirty-nine thousand six Fn map eK a and Ss can ormed. Book of instruction includ- tion that is an elementary text book ed. Practical character read- on Chemistry. CHEMCRAFT isthe ings can be made by anyone, original and pest chemistry outfit. and in accordance with Dr. Used in schools and colleges and en- Blackford’s scientific ob- dorsed by teachers and professors. servations. Very interest- When BA = prt your outfit be sure the ing and instructive for chil- name RAFT is on the box! dren and grown-ups, and the CHEMCRAFT, _ CharacterCraft, youngsters can play an ab- and other Porter Products are sold sorbing game withit. Com- plete outfit, in strong box wherever good toys arefound. Ask Five Fine Outfits! © bs be doing» him a No. 0, 75c; No. 1, $1.50; No. 2, $2.50; No.3, $5.00; No. 4, $10.00 aes and * practical (West of Denver, Colo., and CHEMCRAFT is scien- in Canada, 10% more) tifically correct and is Each outfit is complete in itself and more than a toy. It is contains an assortment of harmless a most useful and sen- sible thing to give him. The will agree mm you—ask him and see! Free to Boys "Who Write at Once ! fen interesting book by about. all Porter and a copy of the Ciub ul apparatus, and Manual of ary oe 3. for them by, mame at your store. Magazine ll of interest- $ oy aa If you cannot’ get what you want ing gy” Lew mig amateur (wees of Denver we will fill your voule direct, post- chemists, chemical Canada, “aoe zee paid, upon receipt ‘of. price. experiments ae Club news. THE PORTER CHEMICAL COMPANY Porter Products Put Science at Your Service Industrial-Arcade Building Hagerstown, Maryland | | | | | | | | 113 UTTOOOOOTTEE DTT TT TT AHA TET POUT 7m uverinivvaevtenvaity sc OUUTATDATIT NTU EA TURN EVONTTONE ITIP ALL LL) LOA OLE ELEY I ee nee

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2) eer, . “ wisconsin ns a panesn aaemene Penne areca Pe 1 ARIE MCE NETL ORG poe spo eB edna estas nim ots pane eth ata Sea, - SG A I RET IT Bd clea got sass + Se ee ee ae : “= Sen eee et eae a Sia! bins ze : . ? aiatboans x snl enc Pe ag oe 114 ‘HIGH 1 SCHOOL COURSE iN TWO YEARS You Want to Earn Big Money! Ard you will not be satisfied unless you earn steady promotion. But are you prepared for ti the job ahead of you? Do you measure up to the standard that insures success? For a more responsible position a fairly good education is necessary. To write a sensible business letter, to prepare estimates, to figure cost and to com- pute interest, you must have a certain amount of preparation. All this you must be able to do before you will earn promotion, Many business houses hire no men whose general te tS is not equal to a high ool course Because big ess refuses to undo cod with men who are pestea § from . promotion by the lack of elementary education. ‘ Can You Qualify for a Better Position? We have aplan whereby you can. We can give you a compiete but simplified high school course in two years, ae vom all the Se oe that form the ion of practical business. It will prepare you to hold your own_where competition is keen and exacting. Donot doubt _ ability, but make up your mind to it and you will 4 have the uirements that will brin success and big money. YOU CAN DO it. Let us show you how to get on the to success. It will not cost you a single working hour. We are so sure of being able to help you that we will cheerfully return to you, at the end of ten lessons, every cent wt sent us if you are not absolutely satisfied. at fairer offer can we make you? Write - It costs you nothing but a stamp. AMERICAN SCHOOL Dept. H-975; te connec scans, > Chicago, fil. 8 Explatnhowl can qualify eae ssooe Lawyer $5,000 to $15,000 Address THE HOME WORKSHOP How to Clean the Under Part of the Boat Hull A PRACTICAL method of cleaning the hull of a boat without hauling it out of the water is shown in the illustration. This device consists of two or three wire WIRE BRUSHES NAILED TO BOARD SIDE VIEW Use this scrubbing-brush when you clean the bottom of a boat. It can be done without taking the boat from the water brushes fastened to a plank with a rope at each end of the plank. This is let down over the bow or stern of the boat and the owner or cleaner pulls this back and forth from above by means of the attached ropes. All of the marine growths, barnacles, etc., can readily be removed. The purpose of cleaning is, of course, to prevent decay and obtain better speed with the boat, as these accumulations hinder the boat’s prog- ress through the water.—G. A. LUERS. Straightening Cotters to Bring Points Together N order to insert a cotter-pin into a cotter-pin hole after the ends are once spread, loss of time ensues unless the points are brought together. The wiry ends will stand open unless Gm" COTTER-PIN WITH POINTS APART y “Gili sa This litte kink is a good trouble- saver, especially for the mechanic they are bent in the opposite direction. To do this, place a nail between the points and press them together with the pliers. Stamp-Pads May Be Made of Type Ribbons Ov typewriter ribbons form very satis- factory rubber-stamp pads. Take a suitable length of discarded rib- bon and wind it around.a piece of card- board cut to fit the pad-box easily. Arrange the loose end underneath, and secure with a drawing-pin or small tack, and place in box. The top layer can be cut away instantly when clogged with dust and dirt, exposing Save up your old the clean inky typewriter ribbons and make this prac- surface beneath.— tical inking-pad Gro. H. HOLDEN. TYPEWRITER BOARD RIBBON Popular Science Montily A Remarkable Typewriter - ati, Why pay rent when z u can own outright a brand new improved Harris Visible Typewriter by making small monthly payments? The Harris is an up to date, efficient and durable full standard size business typewriter. Has universal keyboard. Full visible writing. Silent and speedy action. Built of best materials and fully guaranteed by us. Over 1,500 Harris Typewriters are in daily use in our offices under the most severe service conditions. Send for Free Harris Catalog. Write today for Harris iy ape ae Catalog No. 91P88A It tells all about this wonderful machine. Sears, Roebuckane(o..Chicago ‘pcan es I'm glad , | I said mnie Se | LEARN AUTOS AND TRACTORS Wonderful opportunities constant- . ly offered trained men; we train " you Comme | to start your own usiness Or make good money as — expert, driver, shop fore- an, etc. "7000 graduates making good, Catalog Free. 3 Cleveland Automobile School, 1821E, 24th St., Cleveland, Ohio. Perfect hearing is now being stored in every condition of Seat. ) ness or defective hearing from * causes such as Catarrhal Deaf- ness, Relaxed or Sunken Dru: Wilson Att vm Ear Drums “*Little Wireless Phones for the Ears’? require no medicine but effectively replace what is lacking or defective in thena eardrums, They are simple devices, which the wearer easily fits into the ears wheret areinvisible. Soft, safe and comfortable. rite today for our 168 pagel FREE book on DEAF: NESS. giving you full particulars and testimonials. WILSON EAR DRUM CO., In ted 178 inter-Southern Bidg. ‘LOUISVILLE. K¥, _. that has Automatic Heat Control, and —_ AN EASY WAY TO MAKE MONEY 2: plod along on a small salary, Be independent. Go Go in the tire re- ony One man says “‘I made $60.00 the first we Others si © $200 to to. 8500 @ mon "Soe little capital needed. gy plentiful, Every motorist a pos- sible customer. No experience need We SHAER Tire Repair — | Stilt bth ma Tread Method sed by Tire Manufacturers work =o the o big Nek otal ~ —— = can use it. It’ e only pt eA can’t undercure or overcure a tire. FREE Book “How Shop.” It tells opens po money. _C. A. SHALER CO. 2212 Fourth St. | Waupun, Wisconsin

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December, 1921 - THE HOME WORKSHOP , P ulling Posts Is Rendered Easy by This Method U-SHAPED staple of heavy iron or steel is driven into a post near its base. If a rock or a log is now placed near the post, and a long pole or an iron pipe is placed on the rock and under the staple, sufficient leverage will be exerted to pull up the post. The staple has greater resisting power to bending when driven far into the post, than one or two spikes of the same thickness. Where a simple spike will bend under the strain, this U-shaped staple will not. Such a staple can easily be made from odds and ends found in the junk-box. If it One man can pull a post by this method. Try it and see how easily it will work is undesirable to bend one, one can un- doubtedly be made from some broken pieces of machinery or tools with the aid of a file-—E. BADE. To Prevent a Saw from Sliding to the Ground HEN a man has considerable sawing to do, whether it is regular carpentry work or trees and branches to cut down in the woods, the ordinary sized saw must frequently be laid aside. On resuming the work the saw is picked up from the ground, which necessitates ENLARGED VIEW OF END OF SAW When a saw falls, the teeth are apt to be injured. File these prongs on the end of your saw and lengthen its life bending down, as often no place is available to put it on a higher elevation. This constant stooping on a job that may last for hours is very trying and causes much fatigue. Invariably, when one attempts to stand the saw on end near the job, it will slide and fall. By cutting a V-shaped projection at each end, as seen in the illustration, the saw will stand up without sliding.—ANTHONY E. ZIPPRICH. 115 The Fesler— Style M-73 ‘ | ‘O the man who enjoys the finer, better things in life, The Florsheim Shoe affords quality of unusual excellence and style that is pleasingly correct, at a cost that is low for the satisfaction received. The Florsheim Shoe — $10 and $12 Photographic Booklet “Styles of the Times” on request THE FLORSHEIM SHOE CO. Manufacturers Chicago vor the man \ Bata “who cares > 6 es c SHOE |s SS SeKO / ? Sa ws corn ee ae rn a Make *15 to $25 a Day and be happy doing it ¢ (7 a job you can’t lose! You can make $90 to $150 a week as District Sales Manager for the Wizard Kerosene and ‘“‘Quicklit”? Lamps and Lanterns— if you can qualify! Wewant men who are capable of doing big things —and of earning big money right now. The Wizard Kerosene and “Quicklit” Lamps and Lanterns are the only sure lamps and lanterns that always giveall the light that is needed—never get out of order—cannot leak, explode, catch fire. ‘‘Quicklit”” burns gasoline; lights with ordinary matches. Give more and longer light for less fuel. Only lamps and lanterns made with automatic cleaning needle. Demonstrate these superiori- ties and you will sell one to a dozen lamps and lanterns a day easily. WIZARD LAMPS & LANTERNS You can sell direct or through dealers. Build your own business —have a dealer in every town working for you. We need real men who are able to earn big money. If your time is worth $15 to $25 aday, wire or write your application today withfull particularsofyour ability. The Nagel-Chase Mfg. Co. 271-275 East Erie St., Chicago, Ill. The Automatic Cleaning Needle — a new invention — makes them quick sellers

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116 Popular Science Monthly patentable nature. 130 F St, N. W., PATENTS SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent Free on request. Tells our Terms, Methods, etc. Send model or sketch and description of your invention and we will give our opinion as to its RANDOLPH & CO. Washington, D. C. IF YOU HAVE AN INVENTION and DESIRE TO LEARN HOW TO CORO P eee HOHE HEHEHE HEHE EEE EEEeseseses: THE BOY ELECTRICIAN Practical Plans of Electrical Apparatus for Work and Play with an Explanation of the Principles of Every-day Electricity. $2.60 Postpaid. POPULAR SCIENCE MONTHLY, 225 W. 39th Street, New York © ey oak To the Man With an Idea } I offer a most comprehensive, ex- perienced, efficient service for his prompt, legal protection and the development of his proposition. Send sketch, or model and description, |i for advice as to cost, search through [Rum peice United States patents, etc. Pre- Ha iminary advice gladly furnished with- out charge. My experience and familiarity with various arts, frequently enable me to accurately advise clients as to probable patentab‘lity before they go to any expense. Booklet of valuable information and form for property, disclosing your idea, free on request. rite today. RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington,D.C. 2276-D Woolworth Building, New York City PATENTS | Booklet Free Highest References Promptness Assured Best Results Send drawing or model for preliminary examination of Patent Office records and report as to patentability All Business Given Prompt and Proper Attention WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D.C. PATENTS A Hand-Book of Essen- tial Information and Advice relative to Patents, Trade- ks; Assignment, Sale or Licensing of Rights; Abstracts from Leading Decisions; State Laws on Patent and Trade-Mark Property. FREE! Write LACEY @ LACEY Established 1869 |/Dept. B, Washington, D.C, ‘PATENTS Send us sketch or model for poteptah tity vpinion and exact cost of patent. Our boo! ‘How in a Patent” Sent Free on re- to apply for Patents, Trade Marks, hts, etc.; gives information it every inventor lo f Inventors, who are our clients, are our references. CHANDLEE & CHANDLEE, 25 Years’ Experience 427 7th St. Washington, D. C. yeu pig MCEND FO ) END THIS FQRM DON'T LOSE YOUR RIGHTS | TO PATENT PROTECTION Before disclosing your invention to anyone send for blank form ‘‘EVIDENCE OF CON- CEPTION”’ to be signed and witnessed. A sample form together with printed instructions will show youjust how. to work up your evi- dence and-establish thesame before filing ap- plication for patent. As registered patent at- torneys we represent hundreds of inventors all over the United States and Canadain thead- vancement of inventions. . Our schedule of fees willbe found reasonable. ‘The form “Evidence of Conception,” sample, instructions relating to obtaining of patents and schedule of fees — — request. Ask for them,—a post card will do. PATENTS AND \ TRADE MARKS 274 Ouray Bldg. WASHINGTON, D. C. Originators of forms ‘Evidence of Conception.” think of a simple, practical idea that will fill one of the many re- quests we have on file for new inven- tions? It may mean a fortune for you. Thousands of things are needed RiGut Now. Your brainscan help. Send to- day for our great new book—“‘Invene tions and Trade Marks, Their Protection and Exploitation’’ and learn more about making money from ideas than you ever knew before. It tells many things that are wanted, too. A postal will do— it is free. PATENTS ADVERTISED For SALE FREE In INVENTION And MANUFACTURING _ SUPPLEMENT. Published for the Man with an idea. Gend for free sample copy. One year’ssub- Ow ecription 50c. We help our clients, Without charge, to get the dollars out of their ideas—having facilities none others possess. Advice free. Don't delay—get the ; book at once. AMERICAN — INDUSTRIES, INC. 201 Patent Dept., WASHINGTON, D. C. THE HOME WORKSHOP Attach a Hand-Guard to the Wheelbarrow bY, Fico using a wheelbar- row near a brick wall or fence, the operator’s knuck- les are often skinned. Also many loads are dumped by the operator in order to save hishands. This means great SHEET-METAL GUARD loss of time. oe sineuboes The guard knuckles shown in the il- lustration will protect the workman’s hands. It should be made of iron about 1/16 in. thick, and the part that protects the hand should be comparatively wide. The dimensions can best be calculated to suit the particular conditions.—S. E. GIBBS. Handy Nozzle on the Hose for Fi ling Radiator Saw is an improved way for filling the automobile radiator with water at service stations. Attach a spring lever faucet to the end of the hose coupling as shown. The hose can be kept connected with the main all 2 6.0? Sg on > 7 = = | “> i) N Rani c Sa ~~ i ; voy amin” \ \ ras y \ ae : The spring-lever faucet attached to a water-hose will save time and trouble the time. All the automobilist has to do is to place the nozzle of the faucet into the filler pipe and then press the lever. The flow of water stops as soon as the finger pressure is released.—L. B. ROBBINS. Use Old Books for Filing Bills, Recipes, or Pictures D° not throw away your old dictionaries, atlases, directories, etc. They may be made into holders for filing clippings, recipes, bills, or pictures. With a sharp-pointed knife cut out pages about 4 in. from the binding. Leave about every fifth page, to sep- arate the various sub- jects. These pages can - be numbered, and an - index put inside the _ front cover of the book. If desired, a thumb in- dex can be cut down _ the side of the pages so ; that the Pima tsa may be found quicker.— | A quat wee for ARTHUR GOLDENBAUM. | ST | fu , b as g a yo) old . books

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cx December, 1921 135 S. Broad Street 152341 4 Oey Philadelphia, Pa., Office 4 * = Washington, D. C., Office Victor Bidg. New York Office 1007 Woolworth Bidg. OUR Our Branch Offices In order to assist our clients in patent matters and give them the advantage of every convenience and facility, we have established branch offices in New York, Philadelphia, Pittsburgh, Chicago and San Francisco. These branch offices being located in the principal commercial cities of the United States, together with our main office located near the U. S. Patent Office in Washington, D. C., enables us to more promptly handle business of our clients, particularly as the branch offices are in constant touch with the main office, and fully equipped to handle patent and trade- mark business in all its branches. Our branch offices also enable us to assist our clients in any negotiations regarding the sale or leasing of their patent rights. SPECIALIZATION —OUR STAFF The field of invention is so vast that it is impossible for any one man to become an expert in all classes of invention. Only those skilled in the class to which the invention relates are capable of rendering efficient service. For this reason we employ a number of patent lawyers and mechanical experts who have beer selected for their special knowledge and ability in certain lines of invention. Each case is placed in charge of an expert in the class to which the invention relates. THE VALUE OF YOUR PATENT Will depend upon the skill and care with which your case is prepared and prosecuted in the United States Patent Office. This work will receive the benefit of skill and experience required by long and successful practise. We spare neither time nor pains to secure the broadest possible patents that the invention will war- rant. That every case intrusted to us receives our best efforts and that our work is done conscientiously, skillfully and thoroughly is evidenced by the many unsolicited letters that we receive from our clients. We will furnish upon request lists of clients in any state in the union for whom we have secured patents, OUR THREE BOOKS MAILED FREE TO INVENTORS We have published three very valuable books for inventors which we will gladly send to you free. They contain very valuable in- formation based upon our experience of over twenty years in pat- ent work. Anyone who has an invention and is interested in proper patent protection, or any one at all interested in inventions should write at once for these three books. FORE Ey Our Illustrated Guide Book PATE, HOW TO OBTAIN A PATENT—Sent Free on Request Contains full instructions regarding Patents, Trade-Marks, Foreign Patents, Our Methods, Terms, and 100 Meck nical Move- ments illustrated and described, Articles on Patent Practice and Procedure, and Law Points for inventors. OUR TRADE MARK BOOK Shows the value and necessity of Trade-Mark Protection and gives information regarding unfair competition. OUR FOREIGN BOOK We have Direct Agencies in all Foreign Countries. Write for our illustrated Guide Book on Foreign Patents. SPECIAL OFFER Free Opinion as to Patentable Nature We will gladly give you our opinion as to the patertable nature of any invention which you are interested in and urge that you immediately send to us for our “Evidence of Conception”’ to be signed, witnessed and returned to us, together with model or sketch and description of the invention. Send for this blank form “Evidence of Conception” at once and take advantage of our special offer. EVIDENCE OF INVENTION Our blank form “Evidence of Invention” should be filled out by the Inventor before disclosing the invention. The signing of the form “Evidence of Inven- tion,” which should be witnessed, legally records the date upon which you conceived the invention which you want to protect with a patent. WRITE TODAY Just fill in your name and address and send to the nearest, office and we will send you free of charge our patent book as described above. Highest References Prompt Attention Reasonable Terms VICTOR J. EVANS & CO. PATENT ATTORNEYS MAIN OFFICES, 901 Sth St., WASHINGTON, D. C. Gentlemen: Please send me FREE OF CHARGE your books as described above. PORE Fe aoioce ison Sb Ses SASRTG SOR piel e yc AM See 9 woo oe So he cre mY g Clete PATENTS! Chicago, Iil., Office 1114 Tacoma Bidg. ~ Pittsburgh, Pa., Office 514 Empire Bidg. San Francisco, Cal., Office 1010 Hobart Bidg.

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sercteccet an nn aE Be Se a ean mck, Sen a yes ar i PR eT tee Vi a cer ar mn tn RE ee _— ee i! i a i Mi Py a | ne — as oS sieneree dared ar el ae 118 Mechanical Engineering Learn at Home! Employers are looking for men with mechanical ability. There is an easy, delightful way in which you can learn right at home in spare time. For 30 years the Interna- tional Correspondence Schools have been giving men and women just the training they need for success in me- chanical engineering and more than 390 other subjects. Hundreds of thousands have stepped into good positions through I. C. S. help. Let the I. C. S. help you. Choose the work you like best in the coupon below, then mark and mail it today. This doesn’t obligate you in the least but it will bring you information that will start you on a successful career. This is your chance. Mark and mail the eoupon now. INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7648-B SCRANTON, PA. Explain, without o! g me, how I can quali ad the position, or in the subject, before which I mark ek ELEOTRIOAL ENGINEER | OHEMIOAL noord Electric Wiring SALESMANSHIP Electric Lightin ADVERTISING MAN Electric Car Running tage 4d a lectri: ractio iow Oard en a eeeee RAILROADPOSITION. Eleetrie Machine Designer ae “ oe BUSINESS MANAGEMENT mBOmANEOs LEnOIna BR! Private Secretary AL ENGINEE Mechanical Draftsman na eee Hoshine Guay Practice Stenographer and Typist Toc i sk Cert. Pub. Accountant 00: ow er Traffic Management Givi iL ENGINEER GOOD ENGLISH urveying and Mapping sere Fuca onceed | (errionny ancincen ARCHITECT Railway Mail Clerk Architectural Draftsman Textile Srereese N Supt. PLUMBING AND HEATING AGRICULTU Sheet Metal Worker + pealtryRalsne Spanish Nevigator Automobiles Banking ‘Name. Present Business = o Pp ti Ada Street and No, City. State Canadians }may send this coupon to International Corre- Limited, Montreal, Canada Motorcycle Bargains SAVE 25% to 65% on F age A -_- and oy Motor- m Motor Wiese, Evans all pelos Bicycles. Send for Free Bargain Bulletin and M dreds of Bargains in used, rebu t and new machines,supplies, accessories, AMERICAN MOTOR CYCLE co. Dept. 1202, 2047 W. Chicago Ave., CHICAGO Mi _iie=ns We furnish everything — blue plans—case material, tone arms, motors, full instructions. You can easily make $100 - $200 a month in spare tim Even boys of 14 make thems. lay any record. see tone— to any po parser A frie neighbors. ‘Write now ' for free blue print offer. Get going for holidays. © Choraleon Phon ph Co. 1221 2dSt., Elhart, Ind. THE HOME WORKSHOP Heat Room with Pie-Plate and Gaslight Wo heating the bathroom or other room when there is no fire in the house, as in the early fall or spring, a device can be made with little expense. The materials needed are a few pipe lengths, joints, an old pie-plate, and a small sheet of asbestos. The pie-plate is lined with asbestos and is fastened, by means of small pipe lengths Take the chill from rooms in the morning by using this simple heater and joints, to the gas-jet. It is fastened in the position shown in the illustration. When the heat from the gas flame hits the asbestos-lined pie-plate, it is reflected downward. The plate should be fastened so that it can be adjusted to any position. Reference-Book Pages Held with Tire-Tape ptt a of magazines pertaining to shop- work or papers on some particular sub- ject to be retained for reference purposes are quickly and cheaply bound together with strips of tire tape, as is shown in the attached sketch. A strip of tape is placed on the back edge of each sheet, overlapping the page to ue F acca PAPER OR MUSLIN COVER IIOP WOTES This shop-notes book will stand a great deal of abuse if put together in the way shown attach.to the strip of tape on the adjacent sheet. When as many pages as are desired ‘ are placed together, a sheet of heavy paper or muslin is folded over the book to act as a back. Whenever it is desired to add pages, the taped pages are separated by pulling away from the tape, and extra sheets with taped edges are inserted.—G. A. LUERs. Popular Sctence Monthly Diamonds at Pre-War Prices °="*= the new 1922 Basch De Luxe Diamond Book. Btomends back to Fa gsc Ae 00 3-4k 5110-00, was 147, 74 LAKE: now $3$-S9; wasg0erts Lhe S147-80> wes $197 Weare diamond importers. We sell direct to you canter noe at See prices eliminating middlemen’s profits— 35% to on saved on local store prices. And now with prices slashed to pre-war levels (while retailers are still cfagin to big profit prices) you can make additional ig savings. Free Examination— Money Back Guarantee Resty diamond sent on free examination. We take the. all charges. We also guarantee to refund fall} rice less 10%, if you Tin to return your e allow full price in exchange for another = ‘at any time. Every diamond fully guaranteed. FREE pistons Boot =waite See the sweeping reductions in this new Basch Book. Rare by Ne Semetryellverware, ste, Tels how to L. Basch & Co. Dept t-sco Sts & Quincy Su. , in cash PATENTS TRADE-MARKS COPYRIGHTS Send for our free book a of patent ht ig Beale & Park %: 16S Bread St. Phisdabhe, Ps PATENTS Secured Prompt Service. Avoid dangerous delays. Send for our “Record of Invention” form and Free Book telling How to Obtain a Patent. Send sketch or model for examination. Preliminary advice without charge. Highest References.. Write TODAY. J. L. Jackson & Co., 169 Ouray Bldg., Washington, D. C MakeYour Bike FWy (oyrey yen se ts FASsY to do and at low cost. Your old “foot power” bicycle can be quickly transformed to a speedy, easy-run- ning high power Motorcycle with the Shaw Motor Attachment. Fits any men’s bicycle of any make or size. Chain drive model can be attached in less than an hour. A boy can put it on. No special tools or knowledge ~oeagy Thousands in use. A t Attach mont H-P motor of wonderful efficiency. Simple to attach. Everything furnished complete. ery Owner enthusiastic, All materials are guaranteed. Get one NOW. FREE Sitaspror tf bot sndice Dilechment,. 2 oy Shaw Motor-bicycle--a complete power machine at a low price. SHAW MANUFACTURING CO. Dept. 24612 Galesburg, Kansas ee ee wh w

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December, 1921 p= You Never Need a Gun . until= You NEED IT BADLY Get One NOW— BePrepared BAYARD AUTOMATIC SHOOTS

design and mechan’ e iY perfection of the pistol. Bi maker’s | ar pact. wi Safety device makes ac- \ cidental disc e utterly impossible. Made in three sizes, < Eye Steel. Fully n g one NOW; No. 304. (Sup- te lm ply limited.) a ft) / B y Mail Orders romptyFiled: “Reg 380 Cal*15, We also curry a complete line of Field Glasses, Pistols and Shotguns at extremely low prices. : Satisfaction Guaranteed or Money Back IMPORT TRADING CO., - 258 Broadway, N. Y. City

“DON’T SHOUT” “T hear you. Ican hear now as wellasanybody. ‘How? With THE MORLEY PHONE. I'vea pairin 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 to the ears what to the eyes. comfortable, rmless. Abyone can adjust it. hundred thousand sold. Write for booklet and testimonials. THE MORLEY CO., Dept. 797, 26 South 15th Street, Philadelphia

This nifty little car driven by i SYPHER MFG. CO., 174 Sypher Bidg.. Toledo, Ohio 10¢e CHARGES BATTERY 47,H0ME F-F BATTERY BOOSTER, which is a Magnetic Chips ofCharger on battery terisignis TuraSwite 0! on ‘ and Your Battery will be Charged in the morning. No nnd re —. Aemacter a are Current. e' " a ; Do not think your battery is dead and Worn ¢ Booster sed Ful it wits Lite foe bo oyne w e or a Booster You Save Money, PRE-WAK PICs: BantamType volt batt v6 12 charges 12 volt batieryé amps be 24

166 6 volt batt, t 12 arges 6 volt battery a ~\ Type 1612 charges 12volt bat “se Type 1626 Combination ¢ 6 and 12 volt batteries at 12 and7 am The lara, for heavy batteries, or where time is limited. Shipping eights lete with Ammeter & Battery Clips, 12 to 15 Ibs. Send check for Prompt Express Shipment: or for Parcel Post Shipment add Postage and Ins: ..or tell us to fo: c. 0. D. For GROUP Charpheg cui Y FIER Bulletin 17-8, or or ee w BD. THE FRANCE MFG. GO., CLEVELAND, OHIO, U.S.A. Ci Battery Service & Sales Co., Hamilton,On' ‘anadian Representative: The Technical or Scientific Book You Need. Turn to our 96-page catalog and find just the bock you need on any scientific or prac- tical subject—the latest book by the best author. This is the most complete catalog of its kind issued. You'll refer to it constantly in your work. Only 380 copies remain. With the catalog will be sent the supplements for 1919 and 1920 and new 32-page book list for 1921. Prices are not yet entirely stabilized, but those in the supplements will be 80% cor- rect. If there is any change in price you will be notified before your order is filled. Send for catalog to-day. It's free. There will be no obligation for you to buy, and we want you to know our extensive book department. SCIENTIFIC AMERICAN PUBLISHING CO. MUNN & CO. 235 Broadway, New York City

THE HOME WORKSHOP

Providing a Soft Nose for the Peen-Hammer A SIMPLE modification of a ball peen- hammer for purposes of driving in ball-races or for any other use where a brass or copper hammer is required, as on gears, is shown in the illustration. For this purpose any hammer is suitable, even if the peening end is well worn and

COPPER OR BRASS PLUG ALF OF PEENING BALL CUT OFF AND »8" HOLE: DRILLED FOR PLUG

Use this soft-nose hammer when working with cheap metal that must not be marred battered, as the ball must he sawed or ground off. A -in. hole is drilled in the end to a depth of 4%in. A copper or brass plug is driven into this hole and held with a dowel-pin drilled through at right angles. The soft brass or copper can be replaced as often as is required.—G. A. LUERS.

A Suggestion for a Cork Handle for Your Fishing-Pole I* the cork handle on your fishing-pole is worn, below is described how you can make one at practically no expense. Obtain three ferrules, or steel washers, and a number of large corks. Place one of the ferrules in position, put a few corks over the rod, fasten the second ferrule in place, then a few more corks, last of all finishing up with the third ferrule. Shape the corks roughly by means of a knife and then sandpaper them to the shape shown. Such a handle is as good as any manufac- tured style, and is easily applied to any fishing-rod.— J. H. MOORE.

Add to the comfort of fishing by plac- ing this cork handle on your pole

Try This Emergency Clothes- Line Pulley HEN a new ribbon is put on a type- writer, there is one roller left over. Don’t throw these extra rollers away; they may be useful some day. One use for the old ribbon-holder is to take the place of a broken or worn-out clothes-line pulley. A piece of twine is put through the hole in the center -of the roller and then tied to the hook on the pole. If the knots in the line are too large to pass over the rol-

ler, they will either have to be TYPEWRITER- RIBBON SPOOL | made smaller, or the ends of the rope spliced. —A. GOLDENBAUM. Aa” geabnen C+) ter ribbon spool 119

@ GIFTS Buy NOW (Take ¢ a FULL . YEAR To Pay

BABE RUTH SAYS: “1 have exam- ined Diamonds in a lot of cities , and will say gj tem that, for high » or gee quality and low ring first qual- YAL ity blue white —— vi Pg Diamond pierced can’t be beat.” go4 oe Pate tok 14K “white gold mounting $48.50. Ky mond *

Pay Next Year for your, Christmas Gifts! ORDER NOW DON’T SEND A PENNY —goods come to you for examination. E Pay (1-5) 20% only if you are satisfied— § Take a full year to pay the balance. **ROYAL”’ diamonds are genuine first quality blue white perfect cut. Every article an exceptional value. All goods sent on approval for 30 days’ Trial. Satisfaction guaranteed. No references demanded—no red tape—no money in advance. 10% Discount for Cash. a, yearly Dividends in exchange a lowance guaranteed on every diamond purchased from us. “ROYAL”? CHRISTMAS CATALOG FREE The most complete catalog ever published of Diamond atches, Jewelry, Silverware, Cameras, Ivory Toilet Sets, etc., sent free. Prices the lowest—quality the highest. 30 Days’ Trial and a full year to pay on © everything you orderfrom our $2,000, .00 stock. Send for your free copy today. Address Dept. 417.

‘a Established 1895 , . Sp ade Se ROYAL 2 Waren 3$-37-39 Maiden Lane-Ne work es rama sc

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i y 4 * q } enery saree ier eeetegen seri ret PM SIGE ra ene ea i a ae eT es Ten aed TN Ah It IRE 6 eer ars eae REET MONEE EA - pont rete ere py nace sere ec ie 9 f i } ape ES - By t f i t E +H i MONARCH JUNIOR LATHES The Biggest Little Lathe Built” STURDY small engine Lathe built with the same quality construc- tion that has made INARCH ENGINE LATHES standard the world over. An accurate, dependable machine tool es- pecially designed for and guaranteed to do any small work that any other lathe will do with speed and accuracy. MONARCH JUNIOR will fit in any shop or in a work-room right in your own home. They are especially designed for beginners—are easy to learn to oper- ate and are equipped the same as any larger lathe. The Greatest Achievement in Lathe Building History Monarch Junior § 2 S O 9 inch Engine Lathe Full particulars and a Monarch Junior Cata- log will be sent you on request. The Monarch Machine Tool Co. 201 Oak Street, - - Sidney, Ohio CQ Strength and Service Use the dependable, sturdy strength of Williams’ Drop- Forged Clamps and Lathe Dogs —they’ll never fail you and will last a life time. Clamps—11 patterns, in a wide range of sizes for every pur- pose. Safety Lathe Dogs, Bent or Straight Tail, 1 or 2 screws, 16 sizes. Ask your dealer—Literature on request. J. H. WILLIAMS & CO. “The Drop-Forging People”’ BROOKLYN BUFFALO CHICAGO 7 Richards St. 7 Valean St. 1007 W. 120th St, THE HOME WORKSHOP ‘How Leather Straps Can Be Made at Home FTEN it is necessary to have-a few lengths of narrow leather straps as belts for model machinery. These can be made easily from any piece of available leather. Before it can be cut into straps, it must be cut into circular form. The only requisites are a sharp knife and a small piece of wood. The knife should be as sharp as a razor if perfect results are to be obtained. The piece of wood used can be of any convenient size. One side must be perfectly flat, and this side is further prepared by cutting a mortise on one end. This mortise is cut to a depth slightly more than the thickness of the leather and of a width to which the desired strap is to be cut. Then the knife is firmly driven into a board or into the workbench, and the cir- Small leather belts can be made easi- ly when the leather is cut in this way cular piece of leather placed before the knife. The small piece of wood is placed against the knife, and the leather, which has first been cut a little so that a strip of it can be drawn under the mortise and held in the hand, is then gently but firmly pulled against the knife. When the leether is pulled, it will be found to press against the mortise cut into the wood, and the knife will cut the leather as it reaches it. The leather will tear when the knife is dull.—E. BADE. Do You Make Your Own Wire Terminals? I HAVE seen so many persons use the plain wire ends twisted under the bind- ing-screws of apparatus for connection that I thought I would describe a way of mak- ing your own wire terminals. By employ- ing these connectors, there will be a better SOLDERLESS TYPE The amateur electrician will be interested in this suggestion electrical contact, the wires will not be- come broken, and the possibility of a short circuit is avoided. These connectors may be cut out of sheet copper or brass. . The illustration shows three types of terminals and does not require an explana- tion.—A. J. CHRISTOPHER. Popular Science Monthly AGENTS $450 THIS IS Throw ONLY 20 BOXES A DAY MEANS $18 DAILY PROFIT Ria Cf eaamas meee me ee ee es “LUCKY 11°? Assortment in Display Case Full size of box 6x13% in. Each articlefull drog store size. value $3.35; you sell for $1.50 and more than double your monev. nk of it. e array of fine toilet goods (that always appeals to only @1-80 for theie'il vatiolons the money” it ieee 2 or icles, mone: ours, even if she wpe borrow or it. uss lis like hot cakes—men and women Act Now coining 10 to 20 do! a could sell ‘Lucky 11.”’ 30 other big sellers. Don’t delay a minute. Each day’s delay means big money loss to you. Sample outfit including Display Case will be sent povtoad for 81.50. Write for full details. Hurry! urry! before it’s too late. Act NOW. E. M. Davis Products Co., Dept. 1369 Chicago “Lighting Fixtures” Ready to hang. Direct from man- ufacturers. Completely wired including glass- ware. Send for Catalogue No. 20 ERIE FIXTURE SUPPLY CO. Desk A, Erie, Pa. OEE CS Bes ry PULLS 2% fii For H-P.—Price— © ceo Quality—the best buy ofall. Costslesst Smestee en. — re z 2 to 30 H-P. Wes tenet or Terms, Lifetime Guarantee. New Furniture For Old— This FREE BOOK Tells How Explains how to refinish old furniture to conform with the vogue for enameled and stained effects—how to make your homeartistic, cheery and inviting. Tells how to finish inexpensive soft wood soit is as beautiful and artisticas hard wood. Tells just what ma- terials to use—how to apply them—includes color card—gives covering capacity, etc. We will gladly send this book free and post- paid for the name of your best dealer in paints. And for 10c we will also send you a can of Johnson’s Prepared Wax. S.C. JOHNSON & SON, Dept. PS. 2, Racine, Wis. “The Wood Finishing Authorities’

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el _ dorsed b

December, 1921

ASBESTOS We are miners and shippers of Crude Asbestos in any quantity. We produce all grades at our world famous BELL ASBESTOS MINES, in Canada. We also card fibres, spin yarns, weave cloths, and make all sorts of Asbestos products, For anything you want in Asbestos turn to

Keasbey & Mattison Company Dept. S-4, AMBLER, PENNA., U.S. A. Owners of the World’s Largest Asbestos Mines

Cold Pipe Bending Machines a wen ° the World Eondsol om ic fase. nd or mo- tor operated.

Models E&F Send for Catalog Standard Pipe Bends 1” to 6’ pipe, in stock for immediate yt hh AMERICAN PIPE BENDING MACHINE CO. 51 Pearl Street BOSTON, MASS.

{Music Lessons Peepers

UNDER MASTER TEACHERS. urse by Mail Tat Home: meine y Paderewski. Masterteachers guide and coach you. Lessons a marvel of o wn a completeness. iaeeenen ni are Any Instrument Jr iene ee cours 700 sre interested Music, Violin,Cornet, Mandolin, Guitar Music Violin Cornet Man CATALOG. SEND tecte UniversityExtensionConservatory: 408 Siegel-Myers Bidg., Chicago

10 Gallons Gasoline Free The PaKoT Sales Co., 117 PaKoT Bldg., Kansas City, Mo., will send parcel post paid, to one person in each locality who will use it in his auto, tractor, or gas engine and recommend it, a $1.00 can of No-Carbon Oil, enough to make 40 Gal. of gasoline take you as far as 50, thereby giving you 10 gallons free. It cleans out carbon and lubricates top piston rings while you drive. Don’t send any money. Write for introductory can and it will be sent postpaid. Get on the Staff of —\a Big Newspaper Fascinating work and fine oppor- tunities. Over 22,00C newspapers in U.S.—many with 100 or more writerseach. Wide variety of work—reporting—editorial and feature writing—sports—business and financial—theatre and book | a etc. Newspaper men vileged—admitted where

g uded—always where y~' things are happening — often sent on special trips with all expenses paid —constantly meeting interesting people and seeing the unusual. Good reporters get $5,000 and upa year. Many news- paper writers make $10,000‘to $25, a year. ow easy to for thi newspaper men will teach aay a ii Se ew simple and esting ns you e “Know-How? of their life-long experience. Free book F Book tells everything—salaries paid—opportunities—how you can ree quickly yet Gerenshly qualify for any branch of the work 7 lls H —how it opens the ‘door to m: ‘ine and motion picture e ow and to other opportun how le it costs— position. Book points way to big writing, how we will aid in securing a . 44, 1123 Broadway, New York pacino Cléevelari 7® Year= i A Safe and Sane \\ Motorcycle | Weighs only 175 lbs. As easy A to ride as a bicycle. Simpie, SAN dependable, two-stroke mo- <Ge\ tor. Very economical. Write for Catalogue ‘‘S’

quran \.

THE HOME WORKSHOP

This Photo-Print Washing-Box Rocks Automatically I HAVE used with success the washing- box shown in the illustration for washing photographic prints. It is about 20 in. long, 12 in. wide, and 2 in. deep. The rocker in the middle of box is 2 in. high and

The photographer will not have to watch this washing-tray; it works automatically bumpers on each end are about 14%in. The center upright is about 10 in. high and is made so that it is watertight. Half-inch holes centered 1 in. below the top of the box, give outlet for the water. Place prints to be washed in each end and fill with water, place the box under a spigot giving a slow stream of water. As the box fills, first on one side and then on the other, the weight of the water will cause the box to rock as part of the water ruus out of the lower end of the box:

Equip Your Tenon-Saw with This Guard HE guard shown in the illustration consists of a piece of aluminum or other metal bent at right angles, the length and width depending on the saw’s length, and the distance from top stay to saw-teeth. Two slots are made about 2 in. from the ends. A couple of 4-in. holes are likewise WINGNUT ALUMINUM

MLS 4 Tl, Leh pean Yp 7 re = -: ‘< mn _ —<AB Se VEEL LMA Put a limit gage COW ZZ on your saw when sawing uni- form grooves drilled in the sawblade to admit small bolts. They are secured with wing-nuts. After determining the depth of cut re- quired, adjust the guard in position, and tighten the screws. I find this device especially useful in cutting dovetails; the depth of cut always being equal, measuring is not necessary. The accessory is attached or detached in a second; it may be applied on either side of saw, and does not interfere with its use for all-round work.—GEoRGE H. HoLpEN.

Furniture Polish Renews Old Auto Window Lights Yasmpow lights that are hard to see through because of blurs and scratches can be quickly cleared up by rubbing them with a soft rag saturated with furniture polish. Simply rub them well and wipe off the dirt with a dry cloth and they will shine.-—J. C. Orrory.

When work ae is play Those odd jobs around the house become good fun when you have a Sargent Auto-Set Bench Plane, and your work will ail have a professional finish. Sar- gent Planes are a favorite among good carpenters; they are ideal for home use. The Auto-Set feature enables the blade to be removed, sharp- ened and replaced without re- adjustment—a feature found only on this plane. It saves your time and temper. ; Ask your hardware dealer to show you a Sargent Plane. If you will send us your name and address, we will send you the Sargent Book of Planes without cost. SARGENT & COMPANY Hardware Manufacturers 50 Water St., New Haven, Conn.

The Sargent Auto-Set Bench Plane

Made in six sizes MsSsAR GE Nias

cn'

NEW KIND OF HEAT! Try HtinYour Stove 30 Days Free SERIEIEL The OLIVER O-Gos Burner sample case

| | otal oneal nna

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sein Seems a a ae a Pa ate ag mr ee nn nn anneal —————— . bad “ ee ee ne Shines == - Ga a rae, Ra ae ST eS. rome SS o> y—-) 5 Cad ae ae Q © C2 © = f © C4 C4 - Q Cc Cd Oo a aA ib et a a > = wd a wetter a a = mascatapenayitiniaoats Sroneatarneoaten thslnapecl = ir acre aeee em eee ee i %, s ex 8 $3 X rat 5 , ’ i Oo ‘ g roe [on @; a remy Da 9 2) ‘GF v si BESTKs g 0 So Ss Se Wa se We Bs = > ye uh — eS ween stem enna ENGINES y No Need to Wait Any Longer! Prices are now cut to bed- rock on OTTAWA Engines. Cash or easy terms of payment enables any mantoownan OTTAWA. You get better built engine; more surplus power. Easy to op- erate under all conditions. Get my LOWER PRICES'‘and MONEY-SAV- ING OFFER at Once. Cash or Easy Terms Pay only a little down if you like"and let the OTTAWA pay for itself as i you useit. Gasoline or Kerosene. MJ All sizes for all uses. 1 1-2, 2, 21-2, 3, 4, 5, 7, 10, 12, 16and 22 H-P;all types. stationary, portable, saw rig. Give ——— wed - = — = sur- plus over rated H-P. Built in and guar- = “ anteed by largest Engine and Log Saw _ proportionately Low Prices. 90 me Factoryinthe World. QuickShipment. Days Trial—ti0-Year Guarantee FREE Before you select any engine send for my Special . Offer, Lower Prices and my Engine Book—Free. Send to-day. Use the Coupon below. H.C. OVERMAN, | er OTTAWA MFG. CO. ' 1955B King St. Ottawa, Kans. 4 ee ee MAILTHIS NOW | H. C. Overman, Gen. Mgr. 1955B Ek Ottawa Mfg. Co., Ottawa, Kansas. é Se Special Prices OFTAWA Rurinde, "hice Free Book © How to Save t on Engines."’ 2 H-P Only $38.50 All others sizes up to 22 H-P at Prompt Ship- ment Direct From Facto FID oe be abo ocb'o eeivive B40 wise eege4 i Saves You All 7 Middle Profit @ Address Popular Science Monthly THE HOME WORKSHOP Cats Can Be Kept Off the Back Fence [* you are annoyed by cat serenaders on the back fence at night, an old Ford induction coil, connected as shown, will give the feline visitor something to remem- This small electric-shock outfit in- sures restful nights ber. Two bare wires from the secondary of the coil are run along the fence top and when the cat is on the fence it will naturally come in contact with these wires. Closing the switch will cause any cat to leave the vicinity abruptly.—J. B. MORAN. Pipe-Pulling Tool Is Useful on the Farm 7 pull a pipe from the depths of the earth is strenuous work, but here isa tool that will be a sure help. Get a wagon-tongue and cut it about 8 ft. long. At the large end or butt, screw two steel plates to opposite sides and drill three holes through the plates and timber 6,9, and 12in. from theend. Holes should be % in. in diameter. Then have a black- smith forge a large hook with a flat shank PUSH DOWN HOOK THIS END . SEZ WROUGHT-IRON a - Wa. vitae i ‘ Pulling pipes from the ground is difficult without the aid of a device similar to the one shown and bolt this to the top of the tongue so that the hook lays over the end and down. The standard is composed of three pieces of heavy strap iron bolted together in the shape indicated, with a %-in. hole drilled in the top of each bearing to correspond with the holes in the tongue. Then the tongue is pivoted to any one of the three holes by a %-in. bolt as a pivot bearing. Set this lever so that the hook comes 2 or 8 in. from the pipe and wind a strong chain about the pipe a foot or so below the hook. Pull the turns of the chain tight, so that they bite the iron and hook a link at each end over the hook. This raises the far end of the tongue. Then, by exerting the weight of the body on the end of the lever, with the chain biting good, the pipe will come.—L. B. ROBBINS. an =! 4 ew 48 OO he tlCUmDPlC

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we December, 1921 — THE HOME WORKSHOP Skylight Serves City Dweller as a Hotbed HE foreman of an assembly room had a fondness for gardening. One spring he converted a skylight on top of one of the shop roofs into a temporary hotbed. Sup- ports were placed across the space beneath the glass and in these were set boxes of suit- able size in which the seeds were planted. Needless to say, the plants thrived. and were ready for eating two weeks sooner than if they had been planted in the open air. The skylight proved to be particularly appropriate since it faced the south, and was protected on all sides from cutting SKYLIGHT wl BOXES OF PLANTS An idea for the city dweller who would like to have a garden winds by a 6-ft. wall at the edge of the roof. The plants inside were spared any drop in temperature. Moreover, the heat rising from the rooms below helped the germina- tion process.—-D. R. VAN Horn. A Collapsible Stepladder for Home or Shop Grers are attached to the uprights by means of hinges. Those on one side are on the upper side of each step; those on the opposite side are screwed to the under side, as shown in the picture. The appli- ance, when not in use, folds up flat. The two cross stays are of 34 in. by % in. DETACHABLE BRACES Dy r This stepladder occupies very little space when it is folded un steel, secured at the top by a screw, the other end being held in position by a wing- nut and bolt. The stays will then be found to hold the ladder rigid during use. Out of action, the ladder folds up to occupy a space about 7 ft. long "y 34 in. deep.—GEORGE H. HOLDEN. inet etaiticivn L.S. STARRETT CO., ATHOL, MASS. No. 22 e “Ww” SSAA RENEE iON I TE AAAI IE Sa ASN ‘THE WORLD'S GREATEST TOOLMAKERS Menufecturers of Heck Sews Unexcelied 42-240 fandie BUY A UNION TOOL CHEST New 50 Lam ON THE MONTHLY Power PAYMENT PLAN Make $60 to $100 a Week this wonderful lamp. Gives soft, brilliant ligh ht restful to eyes; ideal illumi: Burns Kerosene or G Clean, | odorless, economical. Burns 6% sir, 4% fuel. Absolutely safe. Lights with match. brighter than wick lamps. Patented. provement of age. Table ging lamps, lanterns. ‘Work all or spare time. You simply take orders. We deliver by Parcel Introducing Greatest j jomene he! Post and missions orders. AG FREE our do collecting. id same day © experience necessary. Get started at once. Bi, now on. Write todey for catalog NIS or THE AKRON LAMP co. 1612 Lamp Bidg., Akron, 0. om-= you teke Here’s a chance to-buy a chest to protect your tools—onterms. 50 dif- ferent styles for every need. to choose from Pay the =asy Way Ask for catalog, Sage te ol this easy payment plan, and send the name of your hard- are dealer. Start now to needed to k RB, our tools safe. Write Ns UNION TOOL CHEST CO. UNION TOOL CHESTS for Machinists, Tool Makers, Carpenters, Steam Fitters, Ga- lity ACY =F a pe 24 MiNSt, Rochester, N. Y- 500% AGENT PROFIT Goldand Silver Sign Letters For store fronts, office windows and glass signs of ali kinds. No ience necessery. Anyone can put em on and make money right from the start. $75 to $200 a Week! You can sell to nearby trade or travel all over the country, There is a big demand for window lettering in every Send for free samples and particulars. Liberal Offer to General Agents METALLIC LETTER CO. 433-A No. Clark St. CHICAGO, ILL.

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Soyge a eee, nso eerontoninenege Raeinte -ah ahltonkes =, - s SRE LOT TS FOI INOS RRS NEL PL ET IOS I OL ET ATT ERLE ERI NS EIT TCT A acco met cmeesocon Se Sa ee x Pon ees Shame SS = baat seat ere 124 Wheels versus Figure-wheels You re developing a ma- chine; you may watch the wheels go round and witness the working of parts. But you can’t tell as much as by watching the figure-wheels of a Veeder Counter! You see the machinery at work. Your counter reports the results. How much production per hour or day; how much pos- sible capacity; how much efficiency secured ?— read that from a COUNTER The above Revolution Set-Back Counter records the output of any machine where a shaft-revolution indi- cates 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 figure-wheels, as illustrated, $10.00 —subject to discount. Cut less than one-half size. Set-Back Rotary Ratchet Counter, to record reciprocating move- ments as on punch presses, $11.50 (list). Smaller counters at prices down to $2.00. The Hand Tally illustrated below is used for counting anything from number of people attending a ball game, to number of packages in aninventory. In the public place it counts persons; in the factory or store it counts stock; in the “‘open”’ it may count anything from cattle on a ranch, to poles on a telephone line! Registers one for each pressure of the thumb lever; counts up to 10,000, then repeats. Can be set back to zero from any figure by turning knob once round. Size, exclusive of finger ring, 2 inches greatest diameter. Price, $5.00. Write us about that count- ing problem of yours — there’s a Veeder just made for it, and fully described in the free Veeder booklet. The Veeder Mfg. co 44 Sarveant St.. Hartford, Conn. vel Science Monthly THE HOME WORKSHOP The Tip-Up for Fishing through the Ice HEN a fish bites, the tip-up shoots up in the air, announcing that you | have made a catch. At once you go to the | hole, pull in the fish, and re-bait the hook. The tip-up is made from a pine board and is about %-in. thick throughout, a trifle thinner at both the small and the large end. It is 114 in. wide at the small end and 8 in. wide at the large end. A hole is bored through this piece near the small end and through this a stick is fitted to lie across the hole. To keep the cross stick firmly in place it is well to sink it into a slit in the ice. Water can then be ~- poured around the end. This will keep the stick firm and im- movable; no mat- ter how great a struggle the fish puts up.— ROBERT PAGE LINCOLN. When through this ‘‘bite signal’’ fishing ice, use A Finger-Nai! File Used as a Match-Scratcher A DISCARDED nail-file can be made into a very convenient match- scratcher. Cut*a piece of cardboard an | inch or two wider and longer than the nail- | file, place the file /on it and fasten | the file, together | : oles | with the cardboard on the wall with |—DOUBLE. two double-point- POINTED ed carpet tacks. _— If you wish, you may make this match-scratcher NAIL FILE more ornamental by placing it on a wooden or metal base and fastening DOUBLE. the file in such a POINTED manner that it Pp TACKS may be taken out to be cleaned and then put back into its place again.— Wo. A. JACKSON. Don’t scratch the wall when it can be prevented in this simple way Carrying the Storage Battery with a Chain NE of the cross-links from a discarded tire-chain may be utilized to advan- | tage as a handle for carrying the storage | battery. Handles made from rope or leather are not satisfactory for any length of time, because they soon deteriorate and then give way under the weight of the battery. The illustration at the left is self explanatory and clearly shows the manner of attach- ing the ends of the chain to the han- dles of the battery box. — WERNER STAAF. & TIRE CHAIN CROSS LINK An eas carry way to atteries *‘We Can’t Keep House Without Sloan’s WE always keep : Sloan’s Liniment right where we can lay our hands on 4 We use it for every sort of external ache or pain, rheumatism, neuralgia, , backaches, stiff joints, sprains and strains. Sold by dealers you know and can trust, 35c, 70c, $1.40 Keep it handy Slioary. Liniment BIGGS. a ‘Wants Furs Ship your furs to > Brags at Kansas ) City and get Highest Prices—quick! No waiting. A fair, square deal toall trap- shonest grading and to prices, always. No “Commissions” deducted. BIGGS hel ou make more money at trapping. FREE! Send name pe and address Uocay & a Subscrip- | the "hs om a SS a i Write Now! oe E. W. BIGGS &CO. 780 Biggs Bldg. Electrical and Mechanical Engineers receive fabu- lous salaries. Thousands wanted. 3 months to 2 a. Practical-Technical training under experts. ot a trade school but a Practical-Technical College teaching electricity, steam, gas, auto-electric, armature winding, drafting. Extensive laboratory ‘and shop oe gg Degrees awarded. Day and night nt Mog En time. Don’t judge us by size of ad. Write for free catalog. Fl LAY gg EERING COLLEGE, 1002 Indiana Ave. Kansas City, New Big No. 15-225 pp. Wireless Catalog Wireless catalog mailed for 12c in stamps or coin. Any wireless amateur will tell you it isthe one catalogue to have. As an ency- clopedia of information it is in- valuable. Thelargest and most elaborate radio catalog pub- lished. Values that cannot be duplicated elsewhere. at, WILLIAM B. DUCK COMPANY 228 Superior St. TOLEDO, OHIO Gibson Instruments the “Music Pals of the Nation" easily and quickly enable you te play the music of the day. Delight your ‘friends, increase your pop- ularity, income and pleasure by playing for social affairs, concerts, entertainments, etc. Organize a Gibson Orchestra; we help; you re- ceive commission on sales, Small payment, then $5 00 a month pays for a Gibson ; brings you wholesome year-round entertainment and profit. Gibsons are the recognized world standard. Guaranteed for life. Liberal al- lowance on old instrument in exchange for a Gibson Mandolin,

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December, 1921 — 125 4 Moen THE HOME -WORKSHOP Drainpipes May Be Used as Porch Supports T tile pipes for drains and sewer; make strong and attractive porch sup- ports. They are more economical than either stone or brick and are much easier to set up. i The pipe that is 12 in. in diameter is C Factory overstock As e Sale,as low as They’re melting away; and after this 10,000 factory overstock lot is sold we'll have to go back to regular prices. P he) al SPECIAL FACTORY OVER- Y if STOCK SALE PRICES Ma Se 100 lots, each...... $11.75 A tile pipe makes a splendid porch 25 lots, each...... 12.00 support when used in this fashion 12 lots, each...... 12.25 a good size to use. It can be made very 6 lots, each...... 12.50 much stronger by filling it with concrete. In case the tile should become broken, its i. lots, each...... 13.00 concrete core will still support the super- Single Motors..... 13.50 structure. The tile is set up with the flange end down on a stone or concrete base. By painting the pipes gray they can be made to resemble concrete very closely. A WONDERFUL MOTOR This motor has just about half as-many parts as ordinary motors. Its sturdy simplicity means longer life and less repair and upkeep expense. Has special fan-cooling system and unique starting and cut-out mech- anism. Motor is 14 hp (tested at factory for 50% overload). . Single phase, 110 volt, 1740 rpm, 60 cycle split phase induction type; suitable for operating washing machines, churns, cream separators, ventilating fans, lathes, drills, saws, grinders, etc. One Year Guarantee. We guarantee every motor sold for one year (not six months, the usual custom). Each motor bears a GUAR- A Quick Repair of a Broken Muffler on a Motorboat |S geen invited some guests for a ride, of course, the muffler on my motor- boat blew out that morning. Not being able to obtain a new muffler that day, and not wishing to disappoint my guests, I pro- ceeded to make a temporary repair. The hole where it blew out was about 2 in. square and about in the center. A piece of galvanized sheet iron fitted around the ANTEE TAG, entitling the owner. to a new motor, express prepaid, should anything go wrong with this motor within the first year of service. Simply return the old motor by express collect in the box in which you receive the new one. CASH MUST ACCOMPANY ORDER or, if you prefer, motors will be shipped by express C.0.D. Prices quoted show an actual loss. The sacrifice is made for the sole purpose of con- verting a factory overstock into cash, for working capital. Interest your friends, and make us a quantity order, to get the quantity price. NORTHWESTERN ELECTRIC COMPANY 410-420 SO. HOYNE AVENUE, CHICAGO muffler served as an outside cover. To hold the sheet iron in place I tied three loops of wire around it and tightened them TAPE Your FORD ting SPORT A Tak inexpensive way of repairing a broken motorboat engine muffler by twisting the ends of the wires with a pair of pliers. This gave it sufficient strength, but to prevent leaking, I wound the entire outside covering with friction- somplete job at quar tape. On testing with the engine running, shoring Roles. se Bn 5 PB ppl eneemaes the leakage was only a few drops of water a | “==S=>__=S “Ueno wee minute. With this repair I ran the boat all day, and it proved very successful. This temporary repair having proved so successful, I decided not to go through the trouble of putting in a new muffler. To insure against leaking, I. painted the out- side of the tape covering with a thick coat Write at once fer full . AMERICAN PRODUCTS CO. 5542 American Bidg., Cincinnati, 0. REDUCED PRICES Back to Normalcy—20% Further Reduction SOUTH BEND LATHES—EST. 1906 Standard i ick a we ate. al of white lead and when dry I wound an- 1023 Lethe $176.00 $210.00 lex 8 Lathe $482.00 $512.00 : "~4’Lat 228. 00; r other layer of tape over it. Another coat of 13’x5’Lathe 304.00 35400|21"x12’ Lathe 848.00 923.00 paint completed the job. I used this outfit 15’x6’Lathe 376.00 431.00 | 24”x14’ Lathe 1140.00 1230.00 the entire season without the slightest Free Catalog No. 67 trouble or a drop of leakage.—B. Fox. SOUTH BEND LATHE WORKS, 433 E. Madison St., SOUTH BEND, IND.

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MRE 4] A 4 an a} 4 : i Bd i : 3 1 i i ‘a 4 RS A RET ‘LAMP 126 SS The SS ad with the CLAMP Everywhere py SE STANDS PAT. U.SA CANADA Anywhere AND FOREIGN CounTRES & Adjusto-lite Reg. U. S. Pat. 8 tine lamp of a thousand practical uses. Clamps —stands—hangs— anywhere andeverywhere. All the light you need where and when you need it. Prevents eye strain—reduces light bills. No other lighting device like it. Solid brass; handsome, durable and compact. Clamp is felt-lined— can’tscratch. Guaranteed $ five years. Complete with 8-ft. cord and plug Get an Adjusto-Lite today. If your dealer doesn’t carry it order direct. S. W. FARBER 141-151 SO. FIFTH ST., BROOKLYN, N.Y. Prices in U. S.A., complete with 8-foot cord, plug and socket. Brush Brass finished, Statuary Bronze or $5.00; Nickel finish $5.50. West of Mississippi, prices 25e per lamp higher. TRADE MB ON a We claim~ and can prove! that DELUXE light weight cast iron pistons will vastly improve the performance of any motor in which they are installed; that they will actually save oil and gas, eliminate vibration, give quicker “‘pick-up’’ and greater power, and lessen wear on bearings, wrist pins and rods, adding to the life of the motor. OP PR Be" Se OEE — T WEIGHT CAST IRON PISTON _— a coe he Successful Light Weight Pistor! © Are From 40 to 50% Lighter Than Stock Factory Cast Iron Pistons Both technical man and layman will appre- ciate the patented scientific ribbed reinforcing design which has a threefold purpose—reduces weight, strengthens head and skirt, and also dissipates heat because of the enlarged radiat- ing surface, thereby insuring a cool-running motor. They can be fitted close, eliminating leakage and piston slap. DELUXE Pistons are made in all standard sizes and all over- sizes for over 1200 makes of internal com- bustion engines. Write for copy of Dyna- nometer test made at Ohio State University. Patented and manufactured by CLARK-TURNER PISTON CO,,. Inc. Station C Los Angeles, Calix, For sale by all good dealers and garage men ats anwie SacWaveie aD ee y ARO ARNG FACT ANU TARO RANG TANGA eee THE HOME WORKSHOP The Old Lawn-Mower Bacontes a Good Countershaft AKE one old lawn-mower with a 16-in. blade, which would mean 211 in. over all. Remove the cutting-blades on the shaft and the wooden roller on the side extension castings. Put on the pulleys (iron if desired) and reassemble. Then FAST & LOOSE PULLEYS 00D BLOCK YExKS° IRON BRACKETS BELT TO MACHINE Use the old lawn-mower as a counter- shaft in your shop clamp the side braces on. These are bent as shown and braced and blocked. The power belt runs over one of the 10- in. mower wheels. This drives the shaft at high speed and the speed desired for operating the machine, etc., is obtained by putting on the right size wooden pulleys. Two grease-cups are tapped in and the countershaft is made at an outlay of a very few cents.—P. P. AVERY. Pail and Tub as an Improvised Air-Compressor jet operating a small blowpipe a steady stream of air may be maintained by means of the improvised arrangement shown in the illustration. The device con- sists of an inverted pail, preferably a large lard-pail, in a tub of water. A connection for the air-pipe is made by screwing an old — WEIGHTS zz This device will produce a slight air pressure that can used in con- nection with the gas flame tire valve or similar part on to the bottom of the pail. A slot at the rim of the pail permits the water to enter when the pail is inverted in the tub of water and forces the air through the hose. A suitable weight is placed on the pail to hold it in the water. When the air supply is exhausted, it is simply a matter of raising the pail, which releases the water, and pressing it down into the tub again. This simple air-com- pressor is used by a local tinsmith in prefer- ence to a foot bellows or other pump, probably because of its inexpensive con- struction and unfailing operation. Popular Science Monthly Be A Floor Surfacing Contractor Make $5,000 to $15,000 or More Yearly New, uncrowded field, Architects and gen- eral contractors know the American Univer- sal and prefer its work. They prefer to sub- let the floor surfacing contracts, as itis abig business initself. We furnish office forms, ad- vertising, etc.—in fact, we practically seta man up in business. Business,comes easily. RESURFACING OLD FLOORS _ eey 7, building, large or small, is a prospect. ndreds of floors right in your own vicinity ~~ resurfacing. The owners will be glad =e aere you do it when you show them how n= 4s 4 Gpickt texty the the wore on be done Universal Electric ¥ —* y “oid floors made like new— Dew floors made per: n't ever set caught out of work again—get into a big paying businessof our wa. sp ou acl pong =~ for machines first month and make big pro’ les. Wr 0- Gay for full information. Say Whether you are a building contractor. THE AMERICAN FLOOR SURFACING MACHINE CO. Originators of Floor Surfacing Machines 524 South St. Clair St. Toledo, Ohio, U. S. A. THE AJAX EYELET FASTENER BINDS PAPERS QUICKLY AND PERMANENTLY It Saves Time by Punch- ing the Hole, Feeding the Eyelet and Clinch- ing it in One - Operation. Drop the eye--- lets into the , magazine and gorightahead. Order from your stationer or direct. Write for our catalogue of office tools MACHINE APPLIANCE CORPORATION 351-353 Jay St. Spec. Dept. Brooklyn, N.Y. 3 e parate ‘articles , Every ». delighted with it. Odd, curious and interesting. Lots 1.25 of pleasure as wellas very use- ul, Itisa . Microscope for examining the wonders of nature. It is also an Opera Glass, a Stereoscope, a Burning Lens, a Reading Glass, a Telescope, a Compass, a Pocket Mirror, and a Laryngascope—for examin- ing eye, ear, nose and throat. It is worth all the cost to locate even one painful cinder in the eye. Folds flat and fits the pock- et. Sa great—you need one. Don't miss it, Sent by Catalog 3 SOMKSON SMITH SCO. Dent. 709 $224 2h tele St. eMIciee Battery Charging Pays $150 to9300 Monthly $20 Brings You an HB Charger Pay balance on long easy terms out of your big monthly profits. No experience or train- ing needed. HB outfits for charging 6, 10.16. 32 or 70 batteries. Economical, trouble- proof. Write us vont needs. Let us recom- \ mend size to make you bi a profits. ) —— NOW, when wlner & ngs best de- HOBART BROTHERS CO., Box $127, Trey, Ohie BE YOUR OWN BOSS. MAKE MORE MONEY With little ital, establish a business Tn your ulcan’ = 7 less cost and bigger There a are Anderson age he in is near Better Mechooling plus "finest tixeclogists AR jeu fey an Anderson V Vulcan. izer, dag refund your $35 gay you per day for each of 0 school days ‘anon we sell the work you We _ tell you how to make money. Write t NDERSON STEAM VULCANIZER co. 1002 Willinese Bldg. Indianapolis, Ind. ¥ EW M OTORS FOR ALL PURPOSES STANDARD MANUFAGTURERS PROMPT DELIVERY ALL SIZES UP TO 5H.P. We Specialize In Small Motors & Generators ALL PHASES AND FREQ le N STOCK AT ALL TIMES Mail Order Small Motor dealers inthe world CHAS. H - JOHNSTOR. oe 140 eae Pittsburgh Pa. WIRELESS, TELEPHONE GENERATORS 500 VOLT- 100 WATT - 3400 R.P.M. FOR @ ae MOTOR GENERATOR. SETS.

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December, 1921 THE HOME WORKSHOP This Sharpening-Tool will Concave the Ice-Skate CFE of the best ways to sharpen a skate is to slightly hollow or concave it in the center. The depression runs the long way of the runner and it is difficult to make it accurately unless you have a tool to hold the round file. The picture shows one de- signed for this purpose and that will do the work well. It is pushed up and down the skate blade lengthwise, the motion being similar to that used by a carpenter planing the edge of a board. You can make this device in a short time out of scrap material and it will serve you well for years. The wood used should be hard and sound. The top piece is 1 in. thick. The blocks between which the skate-blade fits are 1% in. thick. They are screwed firmly to the top, or, rather, the top is screwed SET-SCREW: or bolted to them, WOOD The slot is largere where the piece of round file fits. The file is held securely from slip- ping either way by a short bolt ( — which comes down sate — through the cen- p ter of the top This method of a concaving a skate- piece. The skate blade is simple may be held in one hand while the tool is used, or it may be placed in a vise. The tool sharp- ens the skate in just the desired way and the file may be turned around at will or replaced when badly worn. ROUND FILE Furniture-Repair Kink for Holding Rungs and Legs Te hold rungs or legs in furniture a simple suggestion is offered in the illus- tration. This prevents the rung from be- coming loose, as it invariably does when glued in place without any fastening other than the glue. The fastener is simply a wire nail driven through the leg or rung. After being CLIP OFF | A good method of mending a chair runner or a broken chair leg clipped off at each end with a pair of wire cutters, it is bent back enough to slant slightly upward at the ends. The glue is then applied and the rung or leg driven in flush. The ends of the nail are springy enough to open up slightly and catch in the wood. This method does not disfigure the wood as do nails or screws driven in from the outside. Cut the nail ends short enough to come inside the hole with the rung driven entirely in.—G. A. LUERs. «Calif, 30 Days’ Trial; 10-Year Guarantee, 127 NOW ONLY °(27= Cash, or Easy Terms— Hundreds are paying for their OTTAWAS with part of the splendid profits this fastest-cutting 4 H-P. Log Saw makes for them. Prices cut to bed rock. ° Easy Terms to help you. Wood is in great demand wini as fuel. You can cut wood without any backaches or hard work and increase your income sawing for neigh- bors and selling wood in towns and cities. Send for my Money- Making Proposition today. OTTAWA 4 n-P. Motor |OG 5 AW Fastest - Cutting Saws logs into any lengths—faster, easier, cheaper; cuts down trees; buzzes up limbs, poles and branches. When not sawing, use as portable engine for grinding, pumping, shop work, etc. Friction Clutch, lever contro led starts and stops the saw while engine runs. Power Force Feed makes the OTTAWA saw the human way—safest, ecsiest, best way. Magneto Equipped, at no extra charge. No “extras” to buy. Fastest cutting—310 cuts a minute! Immediate Shipments from factory at tawa, Kansas, or nearest-to-you of these Factory Branches: Pittsburgh, Pa., Indianapolis, Ind.; Atlanta, Ga.; Albany, N. Y.3; St. Paul, Minn,; Dallas, Texas; Pueblo, Colo.; Portland, Ore.; San _ Francisco, The OT- TAWA Tree . Faller attached to Log Saw in a few minutes, - Quick a — Log Saw. en s Log Saw, only $35.25 The OTTAWA runs your washing ma- chine and does other belt work. From Far-Off New Zealand! “Just received my OTTAWA Log Saw. Mighty glad to have it. I put some fuel in the tank, gave her a turn—and she went off like a grasshopper. I am well pleased with the outfit. It is very compact, runs well and cuts fast.’’—SAMUEL T. MILLER, Upper Plain, Masterton, New Zealand. F. R E. E. WV Get my Money-Saving Offer, Lower # Prices and my fine Free Book on ass the OTTAWA. I open your eyes to real money- making opportunities. Send today. Use Coupon Now, 4 heehee | 4 H. C. Overman, Gen’! Mgr., OTTAWA MFG. CO., H. C. OVERMAN, Gen’! Mgr. @ 1807-D Wood St., Ottawa, Kansas. OTTAWA MFG. CO. 1807-D Wood St., OTTAWA, KANSAS ANSE NRE DTT ARS

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—— meets pl SR a LORELEI OGL LE IT BELT A EE OLE ete Saks tiie dlls: Agi . ac tiga naw yes ea Sane ee na eaaetetcceeiet ye Perea AETe a cemeonenias 128 Big Money . Popular Science Monthly for the Man Who Knows What to Do!! Big Opportunities in [7 Auto Game | Right now men like you are want- ed for big pay jobs in the Automo- bile Engineering field. Over 8 mil- lion cars are in operation and there are more jobs open than there are good men to fill them. Thousands of men are needed to keep these 8 million cars in going condition. The percentage of new cars this year is smaller than for several years past. This means more work on the old cars—rebuilding and re- placing parts. Learn at Home— Easy, Inexpensive You don’t have to serve an appren- F ticeship. You don’t have to go to ‘ school and spend hundreds of dollars or. for tuitiori and board. The new Li- ’ brary of Automobile Engineering ' will tell you everything you need to i \ know. It explains everything about = every standard make of car. All the ( brand new models are included as well as afm the cars made for several years back. ne Thousands of pictures show you how everything is done. it. ithe Te aie: 15 Auto Experts Will Help You This library is the work of 15 leading automotive experts who each put a lifetime of experience into it. They know exactly what you need and give it to you in plain everyday Eng- lish. It cost over $50,000 to produce these books yet they are sent to you without a 7 deposit of any kind for 7 days’ free ex- . amination. re | FRE Membership FREE Wpp e@ With each set of Automobile Engineering Books we give a one-year membership in . this Society worth $12.00. This member- bul ail ship entitles you to the following benefits: Consulting Privileges: The Society maintains a staff of Engineers and Experts to work out problems and answer questions by mail for its members. Standard Tests: The means by which you are able to determine your exact fitness for the work you are doing or would like to do. This means finding out how much you really know about your job. Free Employment Service: All members can use the So- ciety’s free employment service to get a better job. This includes listing in the bulletin called “Men.” erican Technical Society, Dept. A-209, Chicago mployment Service. Everything About Every Auto The 6 big volumes flexibly and dur- ably bound contain 2700 pages and more than 2400 pictures, blueprints and wiring diagrams showing the inner workings of every car. Acom- plete index enables you to find the very thing you want in a second or two. No need to go through the whole set or even a whole book to find it. In this way you can devote more time to the most important things but you are saved needless study on the things you won’t have much use for. The information is right on the job though, to help you whenever you need help. A Few of the Subjects Covered Gasoline Motors (Construction and Repair) —Automobiles (General description of all makes)—Engines—Pistons—Accessories— Crankshafts—Crank Cases—Carburetors— Manifolds—Fuel Supply-Valves—Exhaust Systems — Lubrication — Bearings — Fly- wheels—Clutches—Transmissions— Gears —Steering Mechanisms—Axles—Chassis— Springs—Final Drive—Brakes—Wheels— ires—Radiators and Cooling Systems— Rims—Electrical Equipment—Generators —Motors—Ignition — Starters — Lighting Systems—Storage Batteries—Magnetos— elding — Bench Work — Machines— Garage Equipment — Trouble Shooting — Motorcycles—Steam Automobiles—Gaso- line Tractors — Trucks — Electric Auto- mobiles—Fords. Don’t Send Money Now We will lend you the whole set of these great pay-raising books for a week to use as you please in your shop or home. Ex- amine them carefully and decide with the books before you if you want to take ad- vantage of this golden opportunity. Over 75,000 sets have been sold on this no- money-down plan—keep the books a week and send them back at our expense or pay .00 a month until the special price of 4.80 has been paid. (Regular price is 00.) There are no strings to this offer. It is open to every man over 21 years in the United States and Canada. You sign nothing but this coupon. No agent will call upon you. Mail the coupon and get the books, then decide whether or not you want to keep them. Mail the coupon now. American Technical Society Dept. A-209 CHICAGO arcana Send me the 6 volume set of Automobile Engineering books for a week’s free trial by express collect. I will either return the books in one week at your expense or send you $2.80 as first payment and $3.00 every month until a total — Society, including Consulting Privileges, Standard Tests and F A vt oi \ eee i a eS ~ is of $24.80 is paid. With these books I am to receive a free menbenae a i & I tl.» caipciunnenthonniuale 1 RO Ree aE Se i i ERR OceCs UC htt. 2 I Lenin cg nab wes tna baneeeebe puebadaune Lon ane . ML Scuucb ssh ecssbenessesubesnanwcoesseavensse PMEB i. species odensscchecbabos . : & | -Peteence WossecePeocdcocenccsooseosoecocccooscccosce Sencecesoscccccecceoessces

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hly Popular Science Monthly Universal typing is here. People are abandoning. the slow, tiring task of long-hand writing. How long are you going to Have You L d cling to it, in this world of advancement? Everybody dislikes to earne to receive long-hand letters. And everyone shirks at correspond- ° ence when it has to be done the old-fashioned, tiring way. So Typewrite Yet? join the progressive throng—get a typewriter NOW. Free Trial ria We ship the Oliver for five days’ free trial. Let it sell it- self. Or send it back. 14 Months . To Pay Pay for this Oliver while you use it. Only $4 per month and you soon own it. $49.50 or $100? Which would you rather pay for a standard typewriter? ‘For 25 years all standard typewrit- ers have been priced at $100 or over and still are—except the Oliver. It is the only standard typewriter selling at half. It is the only standard, $100 typewriter being marketed direct from the factory. Were it not for this simplified sell- ing plan, the price of the Oliver would also be $100 or over. For it is the same fine machine, the finest model we have ever built. Over 900,000 have been sold. We simply sell the identical $100 Oliver direct from the factory, and subtract all the extravagances of com- plicated selling. We have found that it is needless to maintain a high army of salesmen and agents. We have found it unnecessary to sustain a costly chain of branch offices in over 50 cities. The $50.50 you save is the sum that it would cost us to sell the Oliver the roundabout way. Plus a saving made because of the volume of business cre- ated by our plan. Send No Money We let the Oliver sell itself. We ship it to you for free trial. Then you can compare it with other standard typewriters at $100 or over. You become your own salesman. You are the sole judge. No anxious solicitor will urge you. In the privacy of your own office or home you can decide for or against the Oliver. If you want to own it, send us $49.50 cash. Or if you wish to pay for it in installments, send us $3 after the trial period, then $4 per month until $55 is paid. You can readily appreciate that it takes a super-typewriter to sell itself. No test could be ‘severer. Remem- ber, there need be no fluent salesman. to urge you. If you decide against the Oliver, ship it back at our expense. We even refund the outgoing transportation charges, so that you do not risk one cent in the test. Now we ask you, would you rather pay* $50.50 additional and not get a finer typewriter? Would you care to support a $100 price for the Oliver, and get nothing tangible in return? Or don’t you agree that our new way of selling a is logical? Doesn’t it ap- peal to your common sense? Some of the Famous Users: New York Central Lines, Hart, Schaffner & Marx, U. S. 0 Steel Corporation, N. Y. Edison Co., National Cloak & pe Suit Co., Morris & Co.—and hundreds of others. How to Save The coupon below brings you EITHER a Free Trial Oliver or Fur- ther Information. Check which you desire. This is all you have to do to save the $50.50. Without such a plan, you’d have to pay $100 or over. But this way you not only save— you get the finest typewriter that can be built by a leading maker. It comes fresh from the factory, our latest and best model, a 25-year development. Check the coupon mow and mail it in. The OLIVER Tipewritér Gmpany 1109 Oliver Typewriter Bidg., Chicago, Ill. Pessesaeseseeeeeeueeeeneesee9q § THE OLIVER TYPEWRITER COMPANY, & § 1109 Oliver Typewriter Bldg., Chicago, Il. 8 ‘ Oo Ship me a new Oliver No. 9 Type- & a writer for five days’ free inspection. @ if I keep it I will pay $55 as follows: $3 8 at the end of trial period and then at the 8 Brate of $4 per month. The title to re- & @ main in you until fully paid for. If I @ @ make cash settlement at end of trial & @ period I am to deduct ten per cent and § @ remit to you $49.50. @if I decide not to keep it, I will ship it 4 ne at your expense at the end of five ays. * My shipping point is 4 Do not send a machine until I order 2 it. Mail me your book—‘The High Cost of Typewriters—The Reason and the 4 Remedy,” your de luxe catalog and fur- : ther information. 8 wame 4a H nD OI essa nsscsacs eninge gE 8 Occupation or Business

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Now, why not obviate the Watch- ful Waiting for decay to manifest itself in out-of-doors woodwork by making everything of Cypress, “the Wood Eternal,” in the first place? Well, sure enough—why not go ahead and obviate? This kind of foresight is Some Obviator when it comes to Lumber Re- pair Bills. It is possible that we might have a booklet you could use to ad- vantage—we have 43 of them in the Cypress Pocket Library.. Some have plan-sheets—big and practical and artistic—and ex- clusive—and they cost us some- thing—you nothing. Volume One contains the list. Also what the government of the U. S. A. says about Cypress, “the Wood Eternal.” Our ad- dress is below. What is yours? Is it all right to ask? All-round Helps Department Southern Cypress Mfrs? Ass’n. 1249 Poydras Building, New Orleans, Louisiana 1249 Graham Building, Jacksonville, Florida Popular Science Monthly Contents of the Home Workshop A department for the man who works at home with tools A Radio Receiver for Everybody ............. 84 o Make a Pair of Balances.................. 85 Attractive Ornaments from Clay.............. 86 Moving Shadow Pictures .................... 86 Dry Cells in the Country.................... 88 Oil Filter for Farm or Shop.................. 88 Speed Wrench of Simple Construction......... 88 Build Your Own Air-Driven Sled............. Christmas-Tree Candle-Holders...... ........ 91 A Woodbox Under the Stairs................. 91 Sok OS eee 92 Bench-Hook and End-Wood Planer........... 92 A Boring-Table for the Small Lathe........... 94 PARERG A UGREGON SONG... os 85 ces ce cess 94 To Make a Doll’s House... ....... 2 eee 96 Wood Puzzles that Will Interest.............. 97 Making a Glue-Joint Invisible................ 97 Oe ROR eee 98 To Prevent Breaking a Small Drill............ £8 Housewives Will Find This Baker Useful... .... 98 Improved Spur for Stump-Boring Auger....... 99 Can-Opener Made from Strap-Iron............ 99 Using the Discarded Gasoline Barrel .......... 99 Useful Things to Do at Home ................ 100 Shoe-Polishing Support...................... 101 If Your Pipe Fails ce Sere ee enna 101 Make This Disk-Grinder .................... 102 A Fountain for the Poultry .................. 102 Try a Rubber Hose on the Grease-Gun........ 103 Transforming 2 Kettle into a Glue-Pot ........ 103 To Prevent Wad Mesems from Loosening...... 103 Weather Strip Will Adjust Itself.............. 104 Indirect Light from Old Wash-Basin .......... 104 Old Sink Forms Gas-Stove Foundation........ 105 Homemade Cook-Book Holder............... 105 Pistons Become Serviceable Bench Centers..... | Vulcanizing Molds Can Be Made at Home..... 106 Prva en Clamp for Home Use.............. 106 Ornaments of Hammered Brass............... 107 Wide-Swinging Gate for Farmyard............ 108 Novel Spool and Twine Holders.......... eos OD Spinet Transformed into Bookcase and Desk... 109 Ruler that Will Not Slip..................... 109 Telephone Warns of Rain.................... 110 One Method ot Removing Obstinate Staple... .. 110 Screw-Holder for Starting Screws............. 110 Hinged Tailboard with Eccentric Lock......... 112 Hallstand Built from Old Easel............... 1 Carburetor for the Coal-Range................ 1 Drawing May Cause Error in Machining....... 1 Reflected Light for Indoor Pictures... . . Ay: 1 Winter Use for Electric Fan.................. 1 Cleaning Under Surface of Boat Hull.......... 1 Straightening Cotters to Bring Points Together. | Stamp-Pads Made of ee BEDPONS....5.- 65.5 os 1 Pulling Posts Rendered Easy by This Method. . Peni ey | Standing Saw from Sliding to Ground Attach a Hand Guard to the Wheelbarrow...... 1 Handy Nozzle on Hose for Filling Radiator.... | Use Old Books for Filing..................... 1 Heat Room by Means of Gaslight............. 1 Reference-Book Pages Held with Tire-Tape.... ! Providing Soft Nose for Peen Hammer......... 1 Making Cork-Handle for Fishing-Pole......... 119 Emergency Clothes-Line Pulley............... 119 How gee Oo Straps Can Be Made............ 120 How to Make Your Own Wire Terminals...... 120 Automatic Photo-Print Washer............... 121 Equip Tenon-Saw with Guard................ 121 Furniture Polish Renews Auto Lights......... 121 Cats Can Be Kept Off the Back Fence......... 122 Pipe-Pulling Tool Is Useful on the Farm....... 122 Old Skylight Serves as a Hotbed.............. 123 Collapsible Stepladder for Home or Shop....... 123 Tip-Up for Fishing Through the Ice........... 124 Finger-Nail File Used as a Match-Scratcher.... 124 | - Carrying Storage Battery with a Chain........ 124 Drainpipes May Be Used as Porch Supports.... 125 Quick Repair of Broken Motorboat Muffler..... 125 awn-Mower Becomes a Countershaft......... 126 Pail and Tub as Improvised Air-Compressor.... 126 For Repairing Furniture Rungs and Legs...... 127 Sharpening Tool Will Concave Ice-Skate....... 127 What Is that Question You Couldn’t Answer? Let Popular Science Monthly answer itfor you. Our Service Department will gladly supply information on problems of general science or on home-workshop perplexities. It is conducted for your benefit. Read page 53.

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_ ing Association. This is a December, 1921 “The First Month —And he might have remained a $50 a month job as a farmhand one day—out of a job entirely the next —and then a position that paid him $1,000 the very first month! Such was the sky-rocket career of Charles Berry of Winterset, Iowa. And more remarkable still, it all came about as the result of a sunstroke! How long he might otherwise have re- mained a farmhand, no one can say. Cer- tainly, however, his work held little promise of better things for the future. Then one day as Berry followed his plow across the fields, under the scorching rays of a burning sun, he suddenly collapsed in his tracks. Sunstruck! He was forced to quit. Subsequently he found employment in a variety store. His reward for long and te- dious hours of clerking was $18 a week. Out of the Low Pay Rut Not a very remarkable job—but it meant the turning point in Berry’s life, for it brought the discovery of the way to big earnings, Berry had been noticing the Sales- men who came to call on the proprietor of the store. He noticed their prosperous ap- pearance; they stopped at the best hotels, travelled on the fastest trains; and there was an independence and variety about their work that made their careers look like one long vacation compared to Berry’s job. One day Berry fell into conversation with one of the Salesmen. “Yes,” the latter said in answer to his question: ‘“‘Salesmen do make big money. And here’s the reason: the success of any business depends upon the amount of goods sold. The man who sells is producing profit for his firm. His services are in demand everywhere. He commands big pay wher- ever he goes. And there is — CHARLES L. BERRY Why, it has made Master Salesmen out of men who had previously been clerks, book- keepers, mechanics and so on. If I were you I’d write to the N.S. T. A. Just ask them to tell you about their system of Salesmanship Training and Free Employ- ment Service.” Into the Big Money Class Berry did as the Salesman suggested. The answer he received from the N. S. T. A. absolutely astounded him. It was nothing short of a revelation—it was no limit to what he can earn.” “But a man must have natural ability to become a Salesman.” “That’s an old, out-of- date notion,”’ the Salesman replied. ‘‘Salesmanship to- day is a science—it’s just a matter of knowing how. Take myself for instance. I owe my success to the National Salesmen’s Train- wonderful organization of top-notch Salesmen and Sales Managers formed just for the purpose of fitting men for success in Sales- manship. It enables any- one to become a master of all the Secrets of Selling in his: spare time at home. haven, N. Y. homa City. Other Amazing Jumps to Big Earnings “Last week my earnings amounted to $554.37; this week will go over $400.""—F. Wynn, 4103 Forty- Second St., Portland, Ore. ‘“‘My earnings during the past thirty days were more than $1,000."-—Warren Hartle, 4425 N. Roby St., Chicago, Il. “After six months of success in a position secured through you I am earning $92 a week.” —P. W. Broe- del, 726 Benedict Ave., Wood- “I had never earned more than $60 a month. Last week I cleared $306 and this week $218.”""—Geo. W. Kearns, 107 Park Pl. Okla- the most amazing PROOF of the short cut to big earn- ings that he had ever seen. Warren Hartle, of 4425+ N. Robey Street, Chicago, for example, had worked for ten years in the railway mail service at pay ranging from $900 to $1,600 a year. Then through the N.S.T.A. he became a Master of the Secrets of Selling that brought him $1,000 in thirty days. George W. Kearns of Oklahoma City made $524 in two weeks. Before this he had never earned more than $60 a month. And C. W. Campbell of Greens- burg, Pa. wrote, ‘My earnings for the past thirty days are $1,526 and I won farmhand Wy YG second prize in March although I worked only two weeks during that month,” These are only a few of the cases of amazing jumps to big earnings. Berry was absolutely convinced and decided to accent the liberal offer of the N. S. T. A. to fit him for a position as a Master Salesman. In his spare time at home he learned the funda- mental rules and principles of Salesmanship cover- ing every branch of this fascinating field. Almost before he realized it he was ready to accept a posi- tion as Salesman with a big company to which the N. S. T. A. recommended him. The very first month he earned $1,000. One month his earnings ran as high as $2,140. Startling Proof Sent Free The same opportunity that brought Berry his amazing, quick success is now open to every reader of this magazine. You have only to write to the N. S. T. A. You will receive, without any cost or obligation, the remarkable Book on Salesman- ship and startling Proof that you can quickly become a Master Salesman in your spare time at home. You will read the stories of hundreds of men who today are earning more money than they ever thought possible. What these men have done you too can do. Surely you owe it to yourself to at least examine the evidence. It was worth $1,000 a month to Charles Berry to write to the N.S. T. A. It may be worth that much or more to you. Just mail the coupon. There is no cost or obligation. Address National Salesmen’s Training Association Dept. 15-W Chicago, Ill. National Salesmen’s Training Association Dept. 15-W., Chicago, Ill. Please send me your Free Salesmanship Book and Free Proof you can make me a Master Sales- man. Also tell me how the Free Employment Service of the N. S. T. A. will help me to a Selling position and send list of business lines with open- ings for Salemsmen.

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en = DETROIT RADIATOR ~ OR'S” «TRACT - __MACHINE 'S HOP mobile business offers a_ certain future and exceptional opportunities to the am- bitious man who wants to work intelligently to put himself ahead. Why not make your dream of suc- cess a reality? 9,500,000 automobiles, trucks and tractors in use in this country are but an indication of the immense opportunities in Service Work. Opportunities for properly trained men are unlimited. Competent men are in demand to take charge of garages. Some of the Opportunities A BETTER JOB: In repair shops everywhere incompetent men are working because no better can be had. A good man can get a job at a raise any- where. FARM MECHANIC: Modern farms must have engines, cars, trucks, tractors and trained men to run them and maintain them. Every farm needs a skilled mechanic. ELECTRIC SERVICE: 75% of repair troubles are electrical Not 10% of auto-mechanics are skilled in this branch. Mechanics who will take training in electrical work can double their earnings. BUSINESS OF YOUR OWN: ®: Start a garage, electric service station, tire repair shop, battery station, or welding shop. Or sell cars, trucks, trac- tors, farm lighting systems. Small capital needed, and men who know their business can get that. The opportunities are actually unlimited in every one of these lines. , M. S. A. S. Graduates Succeed Practical training is the reason. The same oppor- tunity is open to you when you are trained to take it, and you can be so trained in a few short weeks, by coming to the Michigan State Auto School, in Detroit the Auto Center. Learn by Correct Methods Endorsed by Leaders of the Auto Industry This school is recognized and endorsed by the automobile manufacturers and leading dealers,—the men who know how training should be given to make the most valuable men. They want mén who have trained their heads as well as their hands,—the S. A. S. kind. Not only were the M. S. A. S. courses outlined with the assistance of the leaders of the Auto in- dustry, but manufacturers everywhere supply us with equipment and keep it up-to-date. They co- operate with us to the fullest extent, and employ our graduates. What We Teach Autos, trucks, tractors, stationary engines, farm lighting systems, tire repairing, welding and brazing, battery repair- ing, machine shop work. Actual practice on the best equip- ment, thorough and systematic instruction. ' Study the pictures on this page and get our catalog show- ing over 100 views of M.S. A. S. training. Money Back Guarantee We guarantee to qualify you fora position as repair man, demonstrator, auto electrician, garage man, automobile deal- er, tractor mechanic and operator, chauffeur or farm lighting expert or refund your money. _Life membership with privilege of our service free at any time, is included with your enrollment here. Learn by Factory Endorsed Methods Packard Motor Car Co. says: ‘‘We have no hesitancy in recommending M. S. A. S. in every particular.” f '@ The International Harvester Co. says: ‘We will gladly cooperate with the M.S. A.S. through our 90 branches.” Our free catalog contains many factory letters. _ Thomas J. Doyle, Dodge Dealer, says: “‘I keenly appre- ciate the great work you are doing for the industry by turn- ing out trained men who can intelligently handle the diffi- cult phases of motor car trouble.” i. Cadillac Motor Car Co., Detroit, says: ‘‘We believe you have the best and most complete school in the country.” Send for 188 Page Catalog ‘ This book tells in detail of the openings awaiting you in this great business, about M. S. A. S. training, methods and equipment. It includes letters from graduates in all parts of the world, telling what this training has enabled them to do, and dozens of letters from leaders in the auto and tractor industry endorsing our methods. There is no obliga- tion in sending for this catalog. It will tell you more about the opportunities for trained men in the great automobile ent I sag sme M.S. A. hyo do for you. 7 _ We will g y reply to perso etters and answer.qu tions fully. Write today. ei Popular Science Monthly _ ELECTRIC SERVICE * i STRIC SERVICE _ 4 6p @ CS Oey, MICHIGAN STATE AUTOMOBILE SCHOOL A. G. ZELLER. PRES. & GEN. MGR. PMOORSED BY THE LEADING AUTOMOTIVE MANUFACTURERS S92 AuTO BLDG.. 3729 WOODWARD Ave.. DETROIT. MICHIGAN. U.S.A.

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December, 1921 See the New Ideas for Men Who Work at Home with Tools, Classified in the Home Workshop Index on Page 2 Popular Science Monthly December, 192] TABLE OF CONTENTS Vol. 99: No. Special Features How to Make an Aerosled at Home Harding’s Portrait Sent by Wireless. ..... lirieke Sree 21 Every-Day Wonders—Facts You Should Know..... ow Explorers Search for Waste Places................++- 24 First Suspension Bridge Since 1909.................. 46 The Next War—Its Effect on Nations................ 26 Making Steel Direct from Ore...............00ee0eee 48 How Four Boys Made Fame and Fortune in Wireless.. 29 Airplane to Carry Twelve-Inch Gun...............0. 61 AERONAUTICS A Plate-Glass Fairyland... tee e cee ceeceees 37 . cual N Picture.. 2] Giant Outdoor Reflector for the Movies.... 38 ny hal enti iieines: emerinene 39 No Telephone Headbands for Despatchers.. 38 EEE BIRARTEOE, 6.5.65 -6:6.0:0 35 0.4ccclnwcereece'e ra 33 Keeps Airplane Engine from Freezing...... ae Bungalows Made from teel Cars.......... e Farmer's Airplane Rises from Barnyard.... 47 Graphite Sorting beg oo. icles cise ee 9 P .Dirigible Directs Land Traffic.......... see boo mm inet sas SUEDE oie 019 's'e's — ied... ombs uce Rioters to Tears........... Seaeaptine: te Coney ne Inspecting High-Tension Telegraph Poles... 42 A New Way to Bob the Hair.............. 42 FOR THE FARMER The Tower Bridge in Valve Fittings ....... 42 Raising Figs Instead of Thistles....... «+++ 35 Caruso Candle Will Burn in 6921.......... 45 Milk Aerator and Cooler ..............06. 40 Plastometer Reads Contour of Head....... 46 Testing the Breath of Bananas............ 40 Printing Our Own Postage Stamps........ 48 Importing City Lighting for the Country... 41 Music Now Comes on the Movie Film...... 50 Grading Wheat in Carload Lots........... 44 Grandstand from Ammunition Boxes...... 50 Rain-Making Machine to Produce Storm... 5! Enlarged Phonograph as Vocal Sign-Post... 50 Ventilated Apartments for Birds .......... 36 Here Ate Two Drumsin One. ..:.......... 50 Wind Creates Natural Draft for Incinerator 57 Scissors Create Scenery ~ — “AR ae 3 Some By Products of Corncobs............ 63 Eortalle T Sent + Sage es -_ monroe ae Seed Potatoes Cut by Machine............ 65 Wooden Tone-Arm for Phonographs....... 54 Homemade Sterilizer for Dairyman........ 68 ‘ brectnang 4 aie on 2 Factory Roof....... + Shoes for the Equine Bog Trotter.......... 72 je nt Bad sige 9 Bo seca: 5 See oe Build a Homemade Water-Pump.......... a Power House Starts When Light Goes On.. 36 i Work: 5... 8 ouse-Moving in the Philippines.......... hats Ciaran rae Sie Movies Carry Their abrig —— a 3 t t Stati I” eee HOUSEKEEPING MADE EASY Be Measured for New Set f False Teeth. . . Holds Lamp Globes Safely............... 38 Fer wna hen + nner eed a eth i aaa +4 Electric Iron Forms Stove...... oe 40 ee eee 6s Their Pores 60 ee wpee, Wisnost suche tad BE. so -c00 7 Pe oa Pest 9 aa a a 63 aby’s Bath and the Latest Improvements. . : : | OOS Sree PORT lea Electricity Heats Water Passing Faucet.... 67 See eee ernet Dxchenis — = Safety-Pin for Milk-Cans ................ 64 INDUSTRIAL PROGRESS Flashlight with 300-Foot Range........... 64 ¥ . . 2 Making Heat Instantly .................. 65 Machine Ties Parcels like Grain-Binder.... 22 To Measure and Record Rainfall.......... 66 Last Explorers Seeking Wealth for Mankind 24 Figod Lights Illuminate Skyscraper........ 66 Railroads Use Buses to Improve Service.... 28 Saidy Date Goes to Quarantine............ 66 Your Chances for Success in Radio........ 29 Sword-Swallowing Made Possible.......... 66 Converor Handles 100 Tons an Hour...... 35 Clock Whittled from Bamboo............. 67 Boxes all 30 Feet Unhurt............... 35 Pockets in Her Hat...................... 67 Print 1500 Photographs an Hour.......... 37 Combination Chair and Umbrella for Artists 67 For Cutting Brass Rods.................. 39 —Spectroscope Detects Bloodstains.......... : Portable Lamp Guard .......... we ssseeees 39 Government Preserves Indian F olk-Songs.. 69 E Elevator Loads Truck Quickly. .... 40 Delivering Beer with a Hose.............. 69 Machine Measures Leather Area.......... 41° Man-Propelled Trolley .................. 69 Horizontal Forge Press Economizes Space.. 42 No Contest for This White PONS 50 6:6 0s 69 Oil Tank Was Moved Nine Miles.......... 45 Moving Roadway for Japan.............. 69 Hydrochloric Acid Removes Boiler Scale... 45 Film-Projector and Screen in Same Cabinet. 70 Suspension Bridge at Kingston...,........ 4% Ralling Desk for Cilgpied Clilden........ 70 Million Tons of Coal from River Beds...... 47 Renews Blotting Surface. ................ 71 Making Steel Direct from Ore ............ 48 Purdue Has World's Largest Bass Drum.... 71 Earth-Borer Plants Dynamite ............ 51 This Extinguisher Uses no Liquid.......... 72 Extracting Oil from Apricot Kernels....... 51 Diver Can Now Light Torch Under Water.. 52 Good Lumber from Dead Trees........ Seas, Tm Rapid Interest Indicator for Banks........ 54 ht Contractor’s Truck Carries Double Hoppers 54 Copyright, 1921 the Modern Publishing Hand-Power Drill for Prospectors......... 55 ‘ompany Fast-Grinding Compound for Bearings... .. 56 PopuLarR SCIENCE MONTHLY is issued Separates pees from Soil ee Nas 64 ae eb ew 57 monthly. Yearly subscription in the United Centrifugal Force ....... enn moceraee 58 States, $3.00. Canada, $3.50. Foreign, It Measures Wire of Any WR oes exes cc 60 $4.00. Single copy, 25 cents. Blasting Fuses Cut to Safe Measure Pr ehassrering.6 66 Advertising rates on application. Entered Handle-Bar and Package-Carrier.......... 66 as second-class matter 28, 1915, at the Machine Makes Five 5 wommmpaas BhaDey ees 67 Post Office at New York under the act_of Writing a Message by Phone.............. 68 March 3, 1879. Entered-assecond-class mat- Building-Block Made on Continuous Molder 72 ter at the Post Office Department, Canada. The contents of this magazine are copy- MISCELLANY righted and must not be reprinted without elite - rmission. H. J. Fisher, President; R.C Civilization Must Abolish War............ 26 Wilson. Vice-President; O. B. Capen, Secre- Ever -Day Wonders... SO ee eer wesc sedcees 32 tary and Treasurer. Hand-Loom Produces Big Cravat Output... 35 si The Canyons of Lower New York......... 35 Modern Publishing Company Adding Perspective to Motion-Picture..... 36 225 West Thirty-ninth St. New York City Elevators that Run ona Curve ........... 36 Polarized Light Reveals Original Picture.... 37 And 164 Other Interesting Items Curtain of Water Safeguards Books........ 72 Disk Improves Phonograph Tone........... 72 Plowing with a Street-Car................ 73 Try These Speed Indicators .............. 74 Keep Your Home Shipshape.............. 83 MOTOR VEHICLES AND ACCESSORIES How Heatless Tires Are Made .......... on Wedged Keys in Transmission Shafts...... 35 Auto Crane for Barge Canals.............. 36 The Tire Is Inside the Rim............... 44 A Homemade Silencer for the Motorcycle... 50 An Improved Storage Battery............ 76 A Jeweler’s Idea of Car-Building:......... 76 Vacuum Cleaner for Automobile .......... 76 Steam-Car Has Engines on Rear Wheels... 77 Fan-Belt Drives Tire-Pump .......... 2... 77 Safety Signal on Fender.................. 77 Keep Grease off the Axles ................ 77 Why You Should Buy a New Car.......... 80 SNE WENO PNGB oo oa Scosche bck widen sc 83 Auxiliary Wind-Shield................... 83 Adjusted Radius Rods Prevent Skidding... 82 For Spreading Automobile Springs........ 82 Special Tool for Wing-Nuts and Petcocks.. 82 NATURAL SCIENCE Earth to Plow Through Comet'’s Wreckage. 23 A Weed of a Thousand Punctures......... 39 World’s Smallest Ornamental Tree......... ai Mutilating Plants to Make Them Grow.... 45 Every Pebble a Hemisphere of Life........ 55 Animal Life in the Sky...........:....... 57 Fossil Shark Could Swallow Small Whale... 60 Dark Stranger Appears in Space .......... 69 PICTORIAL PAGES Railways of Odd Design eS aaa are alc a Oia oi 33 popens Silk-Making Methods he Natural Perfume Industry of France... 49 Tools and Machines that Are Money-Savers. 62 The Story of Radium.................... 70 How to Get the Most from Your Bit....... 73 For Comfort and Convenience ............ 75 Automobile Accessories............. nee ae RAILWAYS Completely Automatic Car-Coupler........ 42 Locomotive Coal Pusher Saves Labor. .... 51 Trolley-Car Gives Local Service from Trains 52 Railway Cars Unload Automatically er eeee Giving the Engineer His Orders .......... 65 SHIPS AND SHIPBUILDING Davits Lowers Lifeboats Quickly ......... 52 Million Dollars Lost if This Lamp Goes Out. 55 Bulges as Protection from Torpedoes...... 55 Mississippi's Shallow Draft Towboat...... 69 Pontoons to Replace Ferries. ............. 71 SPORTS AND PASTIMES Made to Order Collisions for Amusement .. 34 Steel Ukuleles withstand Hard Usage....... 38 ps Help Drive This Bicycle........... 38 Roller Coaster Built by Children.......... 44 Remote Control of Clay Pigeon Traps...... 63 Can You Get These Eye-Testers?.......... 65 Bicycle Steers from the Rear.............. 73 $240 in Prizes Offered in This Issue—See pages 74, 82, 92, and 98

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Sater 5 soci iainaaminca Rate 25 Cents a Word. Sew | Nit ac) A” ii 4 mh ION” i in : weer bate Se Pens Popular Science Monthly teEaERGTS e PISING © a | cl it ‘i ‘t ASE Ey : eR hs E] ER’ ee es nn i Advertisements intended for the February issue should be received by December Ist AUTOMOBILES AND ACCESSORIES MANUFACTURING MOTORS, ENGINES, MACHINERY AUTOMOBILE Parts for all cars—50% off manufac- turers’ list price. Pistons, connecting rods, cam shafts, crank shafts, cylinders, axles and gears. Our new Cata- logue and Used Parts Bulletin now ready. Write for it to-day. Service and satisfaction guaranteed. Auto Parts Company, 4108 Olive Street, St. Louis, Missouri. TOWLINES sixteen feet long with hooks. Small enough for tool box. Replaced if broken within year. $2.50 ee. mw price $15.00 dozen. Sample $1.50. mom to-day. Will buy back any you don't sell. The & Super or Manutacturing Co., Penn Bidg., Cleveland, PATENTS—Write for Free Illustrated Guide Book and Evidence of Conception Blank. Send model or sketch and —— of ~ tee gua od Bd opinion of its patent- able natur Reasonable terms Victor J. Evans « dle 139° Ninth, Washington, D.C. AUTOMOBILE Owners, Garagemen, Mechanics, Re- pet rmen, send for free copy of our current issue. It contains ipful, instructive information on overhauling, ignition troubles, wane. carburetors, storage batteries, etc. Over = 0 Bese illustrated. Send for free copy, —- Auto- e Digest, 323 Butler Bidg., Cincinnati SLICKER Oil, saves 25 to 50% carbon from engine. ys Fully refunded 4 failing $1.00 C. D. Bitcker City. Semeur. STORAGE ey Charging earns unusual profits using HB Charg $20 starts. Balance payments: Box 1, Hobartsons, Troy, Ohio. AUTOISTS: This preparation seals radiator leaks quickiy. No soldering; oesn’t clog radiator, 65 cents Eee paid. Radiator Repair Shop, Dept. M, 799 Drew t., Appleton, Wisconsin. AUTOMOBILIST Attention: Spark Plug Tester tells condition of your spark, most handy article. 25¢ post = Radio Service & Manufacturing Co., Lynbrook, Long Is gasoline. Cleans guaranteed, money treat i gallons gasoline, ir Ge. Gateway Station, Kansas PISTON Rin rfection reached, send for free evidence booklets, ‘It’s User Says that Counts,’’ that’s making the demand for Zelnicker Ever Tytes the ring that saves fuel and oil and increases efficiency, stops oil pumping, and saves reboring of cylinders. Made in all sizes up to 100 inches for boats, locomotives, engines, pumps, com- pressors, airplanes, etc. Will send on trial to anyone com- mercially rated. Ever Tytej Piston Ring Div. St. Louis. FORD ACCESSORIES * WIZARD battery charger for Ford cars, charges 6-volt battery from Ford magneto. Attaches to Ford in few minutes. Guaranteed to work perfect. Hundreds in use. No more oil lamps, electrify your Ford. Price $4.95, tage prepaid. Send money order. Agents wanted. rite for circular. Wizard Mfg. Company, 206 Jefferson St., Portland, Oregon. GASIFIER saves gasoline, hel on: r starting, applied ten minutes, no changes. $1. Detroit Gasifier Co., Detroit. SPEEDSTER Fans. See ‘‘Red-i-Kut” ad, page 125. revents Special price 743 Book Building, ELECTRICAL oe ALARMS: circular. “W: eutt worm ready to install. Write for circu Kuhn, 1806 Lafayette, ‘ot Louis, Missouri WANTED MANUFACTURER of wire specialties and stampings wishes to add additional articles to their line. Have you a uct or a patent? Address Atlas Manufacturing Co., w Haven Connecticut. SPOT Cash for gold and valuables; returned if dissatis- fied. Assaying for prespacters by graduate metallurgists. Central Refiners, 50: Prospect, Champaign, Illinois. WANTED—Representatives in every Factory in the United States. Popular Science Monthly, 225 West 39th Street. New York. UNUSUAL opportunity to earn large commissions in your town. Zelnicker, 1600 Kingsland Ave., St. Louis. DUPLICATING DEVICES “MODERN” Duplicators. up. 50 copies = _ neil, oo. No glue or — »- 0,000 in use. Free trial. Need one? Booklet ee. J. V. Durkin-Reeves Co., Pittsburgh, Pennsylvania. Business Getters. $2.25 FORMULAS FREE—Formula Catalog. Building, Chicago. FIVE formulas, $1.00: Silver Polish Starch Enamel. Formula for Gray Hair, Superior Baking Powder, Sewing Machine Oil, Toothache Drops. Albert Wilkinson, 81 Erie Avenue, Brantford, Ontario. Canada. BEST SHINE Auto, Furniture, Polish. Formula $1.00 Bill. Collins, 4018 Ross, Dallas, Txeas. 3000 FORMULAS—400 pages, $1.00. -Catalogue free. Englewood Book Shop, 7021 D. So. Winchester, Chicago. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells “‘How You Can Use Po! Science ee! Profitably.”. b ige # - like to know, wouldn 5 ot Manager assified averting: Po Science Monthly, 225 West Son Street, ANew Yor Laboratories, Boylston HMM RR LET us be your factory! Write to-day. Logan Company, 222 South Clinton Street, Chicago, ative. ome age ty anything, develop and build special achinery. Get our bookiet, it's oe as you. - G. Clyne Engineering Co., St. Louis, M Missour achine LABORATORY AND CHEMICAL SERVICE CHEMICALS, glassware—complete supplies for the chemical laboratory. Catalogue 5 cents. National a T Supply Co., 241 Pennsy!vania Avenue, Washing- on, CHEMIST will test raw and finished products; formulas; solve industrial problems, and give testimony. J. Gaub, Lexington, Kentucky. YOUR chemical or electrical problem solved for Five Dollars. ‘Write me. W. Stedman Richards, Consulting Chemist, 220 Washington St., Boston, Massachusetts. Read This One! Popular Science Monthly, New York City. Gentlemen: As you know, I have been running an advertisement in Popular Science Monthly for nearly nine years, only missing when I was ‘“‘doing my bit,” and I must say that the amount invested ts small considering the wonderful ORDERS—not merely replies—I have been getting. I also notice that my key shows MORE REPLIES on ‘“‘stationery’’ from your publication than any others, proving that the better type of business man reads the Classified Section. You can count on my ad “‘t. f.” Very truly yours, IRVIN DANIEL WOLF, Printing... This letter is but one of many which come in—VOLUNTARILY—from sat- isfied and successful advertisers. If YOU are interested in direct, profit- able and continuous results at low cost, why not come along with us in the next issue? For further information as to rates, closing date, circulation, etc., address: Classified Advertising Manager, Popular Science Monthly, 225 West 39th Street, New York City. MAILING LISTS MARRIAGES $5.00 per thousand. Other lists. Miller, Box 41, Berwick, Pennsylvania. AMERICAN MADE TOYS MANUFACTURERS wanted for large production and homeworkers on smaller scale for Metal Toys and Novelties, Toy Soldiers, Cannons, Cowboys, pation. Buffalo Bills, Wild Animals, bit ay Bird-Whistles, Race Horses, Fighters, Wagtail Pups, Put and Take Tops and hundreds of other articles. Hundreds and thousands made complete per hour. No experience or other tools needed. Bronze Sea, complete outfit from $5.00 up. We buy these goods all year, paying fixed prices. Contract orders eee with manufacturers. Exceptional high prices paid or painted goods. An enormous business for this year offers industrious men an excellent See to — this field. Write us only if tod ‘— r and information free. Metal 1696 Boston Road, New Yor Quick-Action Advertisements continued on page 8 talog Toy Siamaieevastan Co., ELECTRIC Motors, 50 heavy duty 4% H. General Electric and other standard makes. cycle, single aan. B anteed perfect. $18.00 and J ixonanee, Lancaster, Pennsylvania. 110 volt. 6 60 Pennsylvania Motor SMALL Motors and Generators, 4 H.P., $18.50:% H.P., $38.50; 1 H. P., $68.50. 6 V. charging generators, $10. $6 each. All a both motors and —— up to 5 H. P. i stock at all times. Bargain prices. Motor Sales Dept. 4, West End, Pittsburgh, Pennsyivanis. GUARANTEED Motors, Pograe. 2HP $75. Easy ayments. Other sizes also. us. Box 2, Hob- artz, Troy, Ohio. AVIATION HEATH propellers represent the most efficient method of aerial drive. Each propeller individually designed for the particular work to be done, as laid out by America’s oldest Aeronautical Engineer. Propeller catalog 4c. Heath Airplane Co., Chicago. PROPELLERS for air propulsion. 5 ft. diameter $12. Other sizes in proportion. Hub mountings, bearings sprockets and countershafts complete. 1 scale blue prints for motorcycle-driven snow and ice sleds, 75c. Ford type, $1. Crawford Motor and Aeroplane Mfr., 142 South Rampart Street, New Orleans, Louisiana. FOR November we offer the greatest bargains in the history of aviation. Dope $1.70, turnbuckles all sizes 25c, aero cloth 39c yard, tachometers $10, shock absorber 10c ft., - Curtiss motors $275, Gnome motors =. new propellers $18, clevis pins 2c, "wheel covers $1. 25, steel tubing 5c. Many wonderful bargains in November sale sheet. Heath —_— Co., Chicago. ENTORS desiring information write for our Free Totrenea Guide Book and Evidence of Conception Blank. Send model or sketch of invention for our opinion of its patentable nature. Highest references. Prompt service. Reasonable terms. Victor J. Evans & Company, 151 Ninth, Washington, D. C. BOYS build a three foot model aeroplane. circular. Full size drawing. Ave., Detroit, Michigan. LEARN to fly with America’s oldest aircraft company. Six hours flying worked in with three moths’ shop train- ing at $190.00, makes our course the most complete ever offered, and an opportunity long waited for. Enroll at once. Heath Airplane Co., Chicago. Write for Aero Shop, 3050 Hurlbut MODEL AND MODEL SUPPLIES WE make working models for inventors and do experi- mental se — carry a complete stock of brass gears and model suppl es.. Send for catalogue. Tne Pierce Model Works, Tinley Park, Illinois. GET our booklet before Ponies order for models or any+ thing you need. ag? work the best, our prices right, our Se sae. © . G. Clyne Engineering Co., St. Louis, uri. MODELS and Experimental Work of every description. Lamson Model and Experimental Works, 625 West omer Boulevard, Chicago. MODEL aeroplanes that fly. Buy your complete outfit scale drawings, sittings, compr air motors and ali best model ag nl supplies from the "Wading River Manufacturing Company. Established 1909. Our new = -two page catalon oy d ha ye latest models designs. Send 10c for y Wading River Manufacturing Company, 672 Broadway, Brooklyn, New FOR THE HOME ge, instructions fr clock beg $5.00. Build your own ons : e friends. Write for ten particulars. Clock Co., Nicetown, Penn- sylvania. FIREARMS ~— MAUSER .25 cal. automatic pistols, $11.75; $12.75; f. 0. b. New York; factory all no Ben ooh 88-C Chambers Street, New York ADVERTISER: Ask to-day for a copy of the SS Ae Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells ‘‘How You Can Use Popular Science Monthly Profitably.”” You'd like to know, wouldn’t you? Manager Classified Advertising, Popular ot edly Monthly, 235 West 39th Street, New York. 32 cal. c. O. D. EFFICIENCY CHARTS EFFICIENCY CHART. One side instantaneous aoe ot mtg chart; other | spark method of testing s Price, One Doilar, cash. . E. Wrigley, 225 90th x Brooklyn, New York. LETTER SPECIALISTS FRANCIS writes the Best Sales Letters in the World. Floyd Delos Francis, Box 604, Atlantic City, New Jersey. LETTERS applying for a position of any nature expertly written. $1.00. oyd V. Studer, Canadian, Texas SALES Letters. Multigraphing. Circular Mailing. Miller, Box 4i, Berwick, Lsharmeendutesamuae

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December, 1921 My New Way in Selling How I Learned the One Great Secret of Salesmanship in Twelve Hours ” ’ OUNG man, my advice is, to get into the selling end of the game!” “But——’”’ “No buts about it, if you want to go ahead—sell. It is salesmen we want today—Salesmen. If you can sell things you will never have to worry about securing a position, or demanding a good salary.” “But, Mr. Cranshaw, I have had no experience — know nothing about it, why—” “Then learn, sir—you’ve asked my advice and help, and there it is.” Deeply puzzled, I left his office. Like so many other young fellows looking for their first job, I had no very definite aim. I didn’t mind hard work or small pay, as long as I felt that the future held some opportunity. I had called upon my father’s old friend, Mr. Cranshaw, to help me decide what calling he thought promised the most. The above conversation was the result. Mr. Cranshaw is an experienced business man and I respected his opinions. With his aid I found a job—and a fairly good one as jobs go—with a large farm-machine man- ufacturing company. As soon as I learned something about my product I went out on the road. The optimism of youth was with me. I had a tremendous amount of self-confidence. My product was a good one. But I ran into a snag when I came in contact with the hard-headed men who till the soil. They were of all types, keen, and shrewd progressive men, who wanted to see an actual "as be yg for every penny spent; old- ashioned men who didn’t take to new- fangled methods; big business men who ran immense farms as a side issue. Every one presented a knotty problem. It seemed to me in my early days, that each man had to be “sold” in a different way. I kept a separate “method of attack” for each individual. But, I was not a success. I made few sales. Every now and then, I put over a fairly big order, but I was not a consistent seller. The firm was not satisfied and they said so. I was costing them more than my werk was bringing in. In a very frank talk on2 morning, they told me that if something didn’t happen at once, I weuld be called in from the road. Well, needless to say, | was discouraged. I thought things over. The success of my brother salesmen and competitors puzzled me. I observed them closely and: tried to learn what it was that brought them their big sales. I noticed, to my surprise, that the men whose totals were the largest were the ones who seemed to work the least. But I could find no one trick that any of them possessed which I had not tried. One day I met a hardware salesman in the smoking room of a train. about the usual things for a while then we branched course of his conversation he told me how, We talked into selling methods. In the “In the last nine weeks my sales have topped the list.’ after many years of mediocre success, he finally learned the one great secret of selling and what that secret This thing which so quickly placed me in my present highly-paid position of master- salesman was a knowledge of the One Great Secret in Selling, and its 100 Devices as told in Arthur Newcomb’s astonishing 7-lessons course in Super-Salesmanship. This course, I firmly believe is the nearest existing thing to a Royal Road to Success in Selling. It is not, like so many other salesmanship courses, a theoretical treatise. It is old- fashioned common-sense brass-tacks. Like all other sciences, selling has for its founda- tion a certain bed-rock law. Ignorance of this is the reason so many salesmen fail. Mr. Newcomb takes this law, shows it to you, explains it, and then shows you how to use it. Itis your weapon. And it is worth more than all the tricks and stunts, and theories of selling put together. Mr. Newcomb does not teach or preach. From his years of experience as salesman, sales-manager and student of selling-science he had condensed into this remarkable book, the one great selling secret—and its one hundred simple devices which all suc- cessful salesmen must have. He gives you this secret—that is all there is to it. No matter what you are selling the rule applies. Mr. Newcomb says, ‘‘This is the way to do it. Now goahead.” And it works. It always has worked. It has been tested and approved by every man tom ever is. It was simple as A BG, It almost bowled me sold anything. Conscious- ly or unconsciously every sale that has ever been made, over. The simplicity and practicality of this great basic rule of success dazzled me. My guardi- an-angel must have been watching over when I met that salesman. With impatient eager- ness I started to put into practice my new-found knowledge. The startl- ing suddenness of the results was almost un- canny. After my next turn on the road the senior member of the firm personally congratulated me. My sales on that one trip were larger than the total of my three previous efforts. In four short months I became the best salesman on the 400,000 people have paid $5 or $7 for one of our Self-Improvement Courses—and remem- ber no one was asked to pay until he had five days to examine the course in his own ome. : Until the Independent Corporation published the ‘“‘Roth Memory Course, “Paragon Shorthand,” ‘Mastery of ” “Drawing, Art and Cartooning. S ; J ‘Reading Character at meee “How to ¥ lesm: Write Stories,” “‘Super- anship,”’ and other personal development courses, where could anyone buy similar courses for less than $15 to $75? Because we want to add two hundred thousand more names to our list of satisfied customers at an early date, we are makinga SPECIAL PRICE, $3 (Regular Price $5) Others sell from $15 to $75 Act quickly as this special Opportunity may be open for only a short time. Many urchasers have written letters similar to obert P. Downs, of Detroit, Mich., who recently wrote: : “T can’t see how you ask so little, while others with far inferior courses get from was made by the application of this one tremendous truth, But do not take any- body’s word for it. You can be the judge your- self. It will not cost you one penny. Don’t send any money. Merely mail the coupon or write a letter, and the complete course will be sent, all charges prepaid, at once, so that you may take ad- vantage of the special price and save $2. If you are not entirely satished, send it back any time within five days after you receive it and you will owe nothing. On the other hand, if you are as pleased as are the thousands of other $20 to $80 for theirs.’ men and women who have firm’s roster. I was lead- ing even the oldtimers, And from that time to this I have never once relinquished the lead. Mr. Cranshaw’s promise had come true— “Get into the selling game, if you want to go ahead,”’ he had said—and I had. But before I had found the all-comprising fundamental secret of salesmanship, I had been as near a failure as a man can be. The rapidity of my sensational rise seems almost unbelievable—even to myself. Don’t misunderstand me, I am not trying to pat myself on the back. I am not an unusual man in any way and do not claim to be. What I am driving at is this: If I, a young fellow who almost missed my chance, could, in the short space of four months, become a top-notch salesman, merely by the mastery of this one principle,—others can dothe same. AndI must add my opinion to Mr. Cranshaw’s, the selling game does hold | the greatest promise of all for the - future success, used the course, send only $3 in full payment. You take no risk and you have everything to gain, so mail the coupon now before this remarkable offer is withdrawn. Independent Corporation, Dept. S-7712, 319 Sixth Avenue, New York City. (FREE EXAMINATION COUPON) Fndependent Corporation Dept. S-7712, 319 Sixth Avenue, New York Gentlemen:—Please mail me the Course “Supers Salemanship” ‘for 5 days’ free trial. If I decide to keep it I will remit $$. the Special Price. Otherwise I will return it to you. It is understood that this coupon puts me under no obligation whatsoever.

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Machinist Now He Is a Mechanical Engineer He Used to Make $26 a Week He Now Gets $7,500 a Year John Guest worked in a machine shop with a score or so of others. He could read and write and do simple arithmetic—that was all. Several of the others had received considerably more schooling than he. His advancement began when he took up a course in Mechanical Drafting in his spare time. Once he had learned drafting, he forged straight ahead. He was made foreman for the company, thén superintendent, then, because by this time spare time study had qualified him for the place, he became mechanical engineer for a great manufacturing concern. Most of “‘the others” are still in the shop, or in other similar shops, or looking for jobs in shops. Those who have work earn a little more now, it is true, but their dollars buy far less. Every one had the same chance as John, but— You have the same chance, too. The I. C. U. Mechanical Drafting Course is YOUR oppor- tunity to qualify for a position like John’s. In your own home, in your spare time, without losing an hour from your work, you can make yourself a practical Mechanical Draftsman. Back of the I. C. U. courses stands T. J. Foster, founder of correspondence instruction. the first man in the world to demonstrate that Mechanical Drawing could be taught success- fully by mail. Associated with Mr. Foster as Dean of the Faculty of the I. C. U., is Harry S. Bitting, President of the Williamson Trade School, the acknowledged leader among Ameri- can vocational schools. I. C. U. courses are sold on the Pay as You Study plan. The student is greatly advantaged because, whether he enrolls for cash or on the installment plan, he pays for only a part of his course at a time as he proceeds with his studies. Take the first step toward a position and salary like John Guest’s. Use the coupon. No obligation.

Industrial Correspondence University, Inc., Dept. C, 1504 Locust St., Philadelphia, Pa. Pjease send me full information about the course befadre which I have marked X and about your “Pay as You Study” plan. In asking for informa- tion, I assume no obligation. Mechanical Drafting Architectural <—y 8 Complete Blue-Print Reading Blue-Print Reading for Machinists and Metal Artisans Blue-Print Reading for Carpenters and Building Tradesmen Blue-Print Reading for Structura! Ironworkers Blue-Print Reading Pattern Makers and Cabinet akers Blue-Print Reading for Blacksmiths Foremen’s Course Course in Employment Management and Per- sonnel Activities

Quick-Action Advertisements continued from page 6 FOR BOYS

PLAY Mouth-organ. Complete, easy instructor, 25c. Elsea, Publisher, Bowling Green, Ohio.

STAMPING NAMES

MAKE $19.00 Hundred Stamping Names on Key checks. Send 25c for sample and instruction. PS Keytag Company, Cohoes, New York.

CIGARS, CIGARETTES, TOBACCOS

BUY your cigars direct. | Fifty La Columnas Prepaid toda Agents wanted. Havana Smokehouse, Homelund, seorgia

MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder It contains some really important facts which will prove interesting and valuable to you. It tells ‘How You Can Use Popular Science Monthly ne You'd like to know, wouldn't you? Manager Classified Advertising, Popular Science Monthly, 225 West 39th Street, New York.

MISCELLANEOUS

HOW to Build Beautiful Homes at Small Cost. Read my book on the Twentieth Century Building Materials. oo Dollar. Circulars free. Peter de Linde, Zion, nois.

FOR your lawn use hardwood ashes. Sixteen dollars ton. George Stevens, Peterborough, Ontario.

FRS. lead soldiers; save time. Painting made e: Make device yourself. Instructions postpaid, $1.00. Tock Box 146, Aurora, Illinois. LUMINOUS Paint, Bottle 20c, Laboratories J, Box 316, Portland, Oregon.

TELEGRAPHY

TELEGRAPHY (both Morse and Wireless) and Railway snes taught quickly. Big salaries. Great oppor- tunities and hong anes “044 established 46 years. All expenses tor —Cc. earn lar, part. Catalog free. Dodge's M Institute, K Street, Valparaiso, Indiana.

STAMMERING

STAMMERERS—You can be permanently cured by my course of private individual lessons. Interesting book- _ — Samuel E. Robbins, 246 Huntington Avenue, oston.

ST-TUT-T-T-TERING and Stammering cured at home. Instructive booklet free. Walter McDonnell, 59 Potomac Bank Building, Washington, D. C

ADVERTISING

ONE Inch Advertisement in 100 country town news- pene, © $12.00. Ad-Guide free. Concordia Magazine, DW York, Pennsylvania.

00 day makes classified advertising pay big. Get proposition. Climax Advertising Agency, Desk G, Clinton,

FLYER! 28 words in 250 weeklies, $10. Central Agency, Champaign, Illinois.

ADVERTISE in 24 Metropolitan Dailies, 25 words $15. Heipful Guide listing 1000 publications, 4c stamps. Wade, Baltimore Bidg., Chicago. HAVE your letters, folders, booklets, written by original forceful writer who digs for business—That’s me. Johnson, 2043 Howe St., Chicago. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.’’ It contains some really important facts which will prove interesting and valuable to you. It also tells ‘‘How You Can Use Popular oaroe a Profitably.”” You'd like to know, wouldn't you Manager Classified Advertising, Popular Science *woathly. 225 West 39th Street, New York.

TYPEWRITERS AND SUPPLIES

ALL makes, $15.00 Aad fifteen days’ free trial. Cata- logue mailed on request. Henry Typewriter Company, 217 West 125th Street, New York City. TYPEWRITERS—All makes. Factory rebuilt by ‘*Famous Young Process.” As good, look like, wear like, guaranteed like, new. Our big business permits lowest cash prices. Machines rented or sold on time. Whatever your needs we can best serve you. Write now. Young Typewriter Co., Dept. 204, Chicago.

FOR SALE

U.S. and Foreign military medals, insignias and decora- = of all kinds. Ben Sloan, 88-C Chambers St., New ork.

PICTURES AND POSTCARDS

TEN exquisite Thanksgiving, Christmas, New Years, Birthday, Comic, or Asbury Park postcards, 10c., 75c per 100. Richard Lavery, Asbury Park, New Jersey.

PATENTS FOR SALE

WE have a few practical money making inventions for sale or pete. Adam Fisher Mfg. Co., 183B, St. Louis, issour'

SCENERY FOR HIRE

SETTINGS for Opera, Plays, Minstrels. Plush Drops. Catalog. Amelia Grain, Philadelphia. ‘ MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells “‘How You Can Use Popular Science Monthly a "You'd like to know, wouldn’t you? assified Advertising,

Man Cl Popular Science Monthly, 225 ‘West 39th Street, New York. Quick-Action Advertisements continued on ‘page 10

Popular Science Monthly Electrician’s Wiring Manual Tools and Symbols—Preliminary Suggestions on Building Wiring— Moulding—Flexible Conduit—Rigid Conduit—Fixtures and Their Instal- lation—Switches—General Sugges- tions on House Wiring—Installing Household Electrical Utensils—Wires and Cords — Motors —Transformers —Switchboards and Panels—Motion Picture Theater—Bell Circuits, An- nunciator Circuits, Gas Lighters, Burglar Alarms, Bell Transformers, Door Lock—Elevators—Wiring in Damp Places—Outside Wiring— Grounding and Ground Detectors— Inspector’s Report on a_ Defective Electrical Equipment — Estimating and Specifications—Tables and For- mulas—Electrical Circuits, Calcula- tion of Wiring, Line Losses and Na- tional Electrical Code Discussed for the Beginner—Alternating Currents Simply Explained—Some Things the Electrician Should Know About Storage Batteries— Underwriters’ Re quirements in the Installation of Wireless Telegraph Equipment— Practical Kinks. There are many formulas and tables which are of great value to the electrician. This is a book every wide-awake electrician or any one who wishes to do-any wiring should own, Don’t take chances, but be sure your work will pe the fire in- spector. This nual may save you 100 times the price of the book. 448 Pages, 414 Illustrations, Hand. some Flexible binding. Pocket size. Price, postpaid, $2.50. Experiments With 110- Volt Alternating Current By J. D. ADAMS Here at last is a book that devel- ops a practical working familiarity with the alternating current—the form in which electricity is used in every home. The author shows how this can be done in an inter- esting and inexpensive way. The only way to gaina thorough understanding of electricity as it is used commercially is by direct personal experiment. The knowl- edge thus gained is of vastly more value and importance than that acquired from the performance of the stereotyped series of battery experiments so uniformly de- scribed in the text-books. 256 pages, 135 illustrations. Price, postpaid, $1.75

Construction of Small Al- ternating Current Motors By PROF. A. E. WATSON Brown University This book contains complete in- structions for building small alter- nating current motors in several sizes. The designs will be found in harmony with those of the very best manufacturers and they can be worked out by the amateur for making useful instruments. Some of the subjects taken up are ‘Characteristic Features of Alternating Current Motors,” “Construction of a One-Half Horsepower, Single Phase Induc- tion Motor,” ‘Procedure in Test- ing and Using an Alternating Current Generator or Synchron- ous Motor.” Clear, concise directions and careful drawings are features of this book. Fully Illustrated. Price, $1.50

Popular Science Monthly

New York 225 West 39th Street,

Page 119

December, 1921 “We've got to hold Holloway!” E came in to see me this morning and said the Na- had offered him We've got to meet We've got to hold tional people $5,000 a year. that offer! Holloway. “He’s got just the training and the knowledge we need. We can’t afford to lose him. He’s the most valuable man in his department. “It’s wonderful what that fel- low has done. Out of a $20 a week man, he’s made himself a $60 man and it’s taken only a year. “Since the time I had word from the International Correspondence Schools that Holloway was study- ing in his spare time he’s gone for- ward by strides. the other men would do the same thing. We need more men like Holloway.” MPLOYERS everywhere are looking for men like Hollo- way—men who want to get ahead —who are willing to devote a part of their spare time to train- ing for advancement. Are you in this class? How much longer are you going to wait before taking the step that is bound to bring you a better job and more money? For 30 years the I. C. S. has been helping men and women along the up-road to success in business and in life. I wish some of ' Would you like to be a first- class Mechanical, Electrical or Civil Engineer? A Chemist? An Architect? A Building Contrac- tor? Hundreds of thousands of men have climbed into big jobs in the technical professions through I. C. S. help. Do you want to advance in Business? In Advertising? In Salesmanship? Many of the country’s foremost Advertising and Sales Managers have won success through I. C. S. training. Accounting? Commercial Law? All over America, bookkeepers, accountants, office managers, pri- vate secretaries, are reaping the rewards of time invested in I. C. S. training in these subjects. It takes but a moment to mark the career of your choice, sign your name, clip out and mail the coupon printed on the right. Yet that simple act has started more than two million men and women toward success. You have seen it in almost every magazine you have looked at for years. And while you have been passing it by, more than ten thousand men and women each month have been making it the first stepping stone to real suc- cess in life. Will you still turn away frem Opportunity? Can you still go on, putting in your days at the same grind, getting the same pay envelope with the same insufficient ‘ sum, when such a little thing can be the means of changing your whole life? You can have the position you want in the work you like best, a salary that will give you and your family the home, the comforts, the little luxuries you would like them to have. No matter what your age, your occupation, your education, or your means—you can do it. All we ask is the chance to prove it. That’s fair, isn’t it? Then mark and mail this coupon. There’s no obligation and not a penny of cost., It’s a little thing that takes but a moment of your time, but it’s the most important thing you can do to-day. Do it now! = — TEAR OUT HERE = ee oe INTERNATIONAL CORRESPONDENCE —— BOX 7646-B SCRANTON, Without cost or obligation, please explain sa > i quality for the position, or in the subject before which have ye an X in the list below:— ELEC. ENGINEER BUSINESS MANAG’M’? Electric Lighting & Rys. SALESMANSHIP Electric Wiring ADVERTISING Telegraph Engineer Railroad Positions Telephone Work ILLUSTRATIN: ae | = & Sign Ptg. Machine Shop Practice Privete: Secretary Toolmaker Desioos Corvenpendent Gas Engine Operating IK KEEP’ CIVIL ENGINEER rapher & Typist Surveying pping on ub. Accountant MINE FOR’N or ENGR. TRAFFIC MANAGER STATIONARY ENG Railway Accountant Marine Engineer Commercial Law ARCHITE OOD ENGLISH Contractor and Builder ‘om. School — Architectural Draftsman CIVIL SERVIC Concrete Builder AUTOMOB Structural Eng Railway Mail Clerk ineer ING & HEAT’G Mathematics : Agvet eri culture Spanish Bonking | H Teacher 7-1-2 State

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Se a ia ee la eS ina od sn ee SN ied 10 Quick-Action Advertisements continued from page 8 No need for any man to remain where advancement is slow and the pay small. Drafting opens the way to important positions and high salaries. Many drafts- men earn $60 to $150 a week and are in line for promotion to even higher places. THT TA Big Jobs (aga Ready— : L y ( \ Not enough really expert Draftsmen - w are available for the higher posi- tions that are : open—which means that op- portunities are > always waiting for the man who can qualify. Factories, architects, electrical plants, contractors, sheet metal works, engineering coneerns are constantly on the search for pro- ficient Draftsmen. Train Under the Chicago ‘‘Tech’’ Experts The Practical engineers at Chicago Technical College will give you training which will make you also an expert. They will teach you the methods they use in their own work—prepare you to step into a pay- ing position. This at the Col- lege or by mail. Small fees. Easy terms. FREE Lesson Trial lesson is sent to show you how we instruct by mail. No cost to you. Just send coupon. Get the lesson, catalog, etc., also free outfit offer. SEN, Act—to-day. Put X in the coupon to show which course pegs ee ee on as oe a ee ee ow oe interests you—then mail it. CHICAGO TECHNICAL COLLEGE 1231 Chicago ‘‘Tech’’ Bidg., Chicago, Ill. Learn by Mail” Send Free information on subject marked X: C Machine Drafting CD Aute. Engineering I CO Electrical Drafting CO Aere. Engineering | C Architectural Drafting CD Plan Reading —Buildings © Strectural Drafting Ci Estimating—Buildings I OC Sheet Metal Drafting 0 Plan Reading—Machinery i CF Topographic Drafting C Plumbing, Heating, ete. CD Steam Engineering | Name. ee een Se ee eee err I Address ...... pap ssehenee ab eebhss ssee0 ee | PONE TREN ors a bod0ss coacner ere | College or Home Study, State which.......... I Free Trial Lesson Inclided ) ane J Inquiry Is for j Drafting or Plan Reading. q Hy | | i | l C Surveying l : i I | I Sond ss teas elie ne nw glo estima aliens PRINTING, ENGRAVING, MULTIGRAPHING x 2” Labels, $33.00. 3,000, $2. 100,000 1 Save 30% Wolf Labels, § Station E, Philadelphia. 250 BOND Letterheads and 250 Envelopes for $2.75. Write for Pricelist and Samples. Balkow Printing Com- pany, Meriden, Connecticut. LETTERHEADS, Envelopes, 500 $2.65. Samples Free. Quality Printery, Marietta, Ohio. BETTER printing for less money! Send for our large package of samples of hundreds of items every user of printing is interested in. These samples worth dollars will sent for 10 cents to pay postage. Ernest Fantus Com- pany, 525 South Dearborn Street, Chicago. PRINTING—The Better Kind. Gummed Labels, ete. May we quote you on your needs? Olde Tye Press, 328 Richards Avenue, S., Dover, New Jersey. EMBOSSED Business, Personal Stationery. Samples, Stamp. Daniels P. Company, Pittston, Pennsylvania. QUALITY PRINTING—1,000 Letterheads, Envelopes, Cards or Statements, $3.00. Gum Labels 50c. per 1,000 up. Multigraph Letters, $5.00 1,000. Samples free. Howlett’s, Paris, Illinois. PRINTING of Pg, 4 Gpaettotion. Our prices talk. Samples’ Free. H. Kraus, 409 Chestnut Street, Milwaukee, W Societe. QUALITY Printing for less—i000 Letterheads or on $3.00. Economic Printery, Leonia, New ersey 250 Letterheads or envelopes, $1.50. Other printing’: Samples stamp. H. Roney, Paris, Missouri. SEND 2c for our me before ordering. ‘‘Mailor- press, 2818 Congress, Chicag MR. ADVERTISER: Ask so-tey for a copy of the Fe nage og Advertising Rate Folder.” It contains some really important facts which will prove meres and valuable to you. It also tells ‘‘How You n Use Popular —— a tog, ” You'd Ciike to know, wouldn’ Man Classified Advertising, Popular ot wey Monthly, 225 West 39th Street, New York. GUMMED LABELS CATALOGUE, samples free. American Gummed Label Co., Dover, New Jersey. INFORMATION RELIABLE information furnished on any subject or money refunded, Co-Operative Service, Times Plaza Box 864, Brooklyn, New York. INFORMATION furnished. . subjects. Charge 1.00 per subject. Money back arantee. Answerall Information Bureau, 463 East issth Ss Street, New York. DOGS—BIRDS—PETS RABBIT Hounds, Foxhounds, n, Opossum, Skunk, Squirrel Dogs, Setters. Circular oo. = Brown's Kennels, York, Pennsylvania. EDUCATIONAL AND INSTRUCTION LINCOLN-JEFFERSON University. Home study in Academy College, Theological, aaa. a. Pharmacy. Business and Graduate Schools, leading to degrees. Lock Box 239G, Chicago. FREE. Learn to write Advertisements. Accept position or work aap evenings country. AL. ociting your I made $160,000 le Lesson Department + rs Cortlandt Street, New York. BOOKKEEPING self-taught in a week. Send $2 for “Duke's’ Columnar Bookkeeping” containing complete charts and explanations. Newton Dukes, Fox Street Sta- tion, New York. EARN $35 to $150 a week. Learn Mechanical Drawing. Complete Course in short time. Easy payments. Diploma when qualified. No interference with present occupation. Uncrowded field with more positions than we can fill. 84, Albany, New York. INVESTMENTS UNUSUAL Investment ya Make money do triple duty. Save 1 Save property =. age, earn profits, becoming stockholder manufacturing Safety Device. Write for particulars. ~eepmreeene Haas- Frederick Corp., Allentown, Pennsylv: GAMES AND ENTERTAINMENT FOUR Moale C Coastnas and Samples—15c. Gilmagico, Morgan Park, Illin: 250 Parlor Tricks, 25c; Big Catalog, 2c. Harvey Teeple, Decatur, Indiana. MAGIC Entertainment Supplies. Jokes, Novelties Cardtricks, Illusions, ners Gazing Acts,’ Sensational apes, Books. Big Illustrated Professional catalog free. 55 Stage Illusions catalog 25 cents. Be a Handcuff King— 0 Sensational Escape Secrets $1.00—Special Bargain. eaney Magic Company, Desk 110, Berlin, Wisconsin. “MARGO” psychic ball— Will mystify, baffle and amaze your friends. Pezometh ing new, novel and entertaining. Descriptive circular free. James T. Herr, 2919 W. North Ave., Baltimore, Maryland. TRICKS, jokes and puzzles. Get our catalogue first. Agents Supply House, Binnewater, New York, Dept. P.S. 9. PLAYS, musical comedies and revues, minstrel choruses, blackface skits, vaudeville acts, monologs, dialogs, recitations, entertainments, musical readings’ stage andbooks, make-up goods. Big catalog free’ S. Denison & Co., 623 So. Wabash, Dept. 26, Chicago" MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising. Ra Folder.” It contains some really iapprsent fatts which will prove interesting and valuable you. It also tel w You n Use Popular Sar eral Monthly Prontably. 3 You'd ike to know, wouldn’ Classified Advertising, Albany Institute Mechanical Drawing, Dept. C, Lock Box you? Man Popuiar Gelenes ‘Monthly, 225 rest 39th Street, New York. Quick-Action Advertisements continued on page 11 Popular Science Monthly BE, A RAILWAY RAFFIC INSPECTOR Many Openings at Good Pay Earn up to $250.00 and $300.00 per month, expenses paid, in this fascinating new proiession. Interesting, pleasant work; travel or remain near home. Brings you in contact with prominent railway officials ; splendid oppor- tunities. We Guarantee You a Position Prepare in three months spare- time study at home. Any aver- age man can qualify. We then guarantee you a position at $110.00 a month, expenses paid, or refund pene money. ou take no ris Don’t Delay—Investigate Now while more are needed than are trained. Send today for free Booklet No. D-402. Standard Business Training Institute BUFFALO, WRITE THE WORDS FOR A SONG We revise poems, write music and guarantee to secure publication by a New York Music Publisher. Our Lyric Editor and Chief Com- poser is a song-writer of national reputation and has written many big song-hits. Submit poems on any subject. We examine them free. BROADWAY STUDIOS 249A Fitzgerald Bldg., Broadway at Times Sq., New_York. Wrestling Book FREE ed fur itag an expert wrestie! ‘have By mail ee rivelgp.s marv Farmer Bares School of Wrestiog, 1789 Ramge Bldg., Omaha, Neby Hotels Need Trained Executives Nation-wide demand for trained men and women in all departments of hotels, clubs, and apartment houses. Uncrowded field; fine living, "quick advancement in the big hotels of the Unit go tay America’s Fourth jonpest Industry. tatistics show that ONE_ IN ERY TEN HOTELS WILL HAVE AN OPENING FOR A MANAGER THIS YEAR. Thousands of other positions also open to those who qualify through training. The Lewis School guarantees to give you the valuable knowledge that it has taken some of the most successful hotel men years to obtain—men who are now making $5,000 to $50,000 a year. All of your training will be under the personal direction of - Clifford Lewis—a hotel expert of national reputa- tion. A few spare-time hours a week given to the simple, clear lessons of the course opens Free the way to a good position, a fine living. and a hand- gome salary. The ‘training will in no way inter- Coupor fere with your present vities. Send today for FREE BOOK ‘“‘Y Bi i Opportunity.” Don’t wait a minute you ’ T fonts ot lose the opportunity of a lifetime. raining the coupon Now. Your whole Room 2719 future may depend on i Weehington, D.C. Founded 1916 Send me without Lewis Hotel Training School ’ «obligation the FREE BOOK _CLIFFORD LEWIS, Pres. ‘Your Big Opportunity.’’ Room 2719 Washington Spot ke Caleb aw bene’ . Ee ie ME eee ae cl euk ap see ee ° ~~ lie mae mk =~! sitvearsnwe liaewm 2 Imm pos

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| | hl Sh Mechel Moda dilly > | 5 ie \ We ———

December, 1921 FOR MEN AND WOMEN

BE a detective. Excellent conerwaniy good pay, travel. write C. T. Ludwig, 424 Westover Bidg., Kansas City, Missouri.

GENUINE Indian Baskets—Wholesale, Catalogue. Franklin Gilham, Kelseyville, California.

“SEXUAL Philosophy,”’ 12c. Clear, enol, authori- tative, complete, best, satisfies. Fred B. Kaessmann, Lawrence, Massachusetts. DETECTIVES—Excellent opportunity. Fascinating work. Experience unnecessary. Particulars free. Write. American Detective System, 1968 Broadway, New York.

5 MASTER Keys and Novel Key Chain, $1. Open and test thousands of different locks. They have satisfied thousands of purchasers and are used and recommended by locksmiths, janitors, detectives, firemen, policemen, travelers, etc. Master sf Company, 40 Manhattan Build- ing, Milwaukee, Wisconsin.

ARE You Interested in your future? Trial reading 9 oe and 10c. F. Crane, 834 Advertising Bidg. Chicago

—- SUCCESS or failure—which is your destiny? Scientific information. ‘‘Success’’ pointers and personality sketch for 10c and birthdate. hompson-Heywood, Dept. 700, Chronicle Bldg., San Francisco, California. YOUR horoscope covering full year for 35c. Includes an extensive reading, valuable daily guide, large pictorial chart and special forecasts for each month. Scientific, complete. Try it! Money back if dissatisfied. Give birthdate. Ad- ne 4 L. Daniels, Flatbush Sta., Box 32, Brooklyn, New York. MAGIC Words—Amazing sure method of obtaining your desires. Postpaid for dime. Smedley, 145 Miller, Brooklyn, New York. START Oil Painting, Landscape, and Portrait Studio Quickly learned, no brushes used, no transfer or chemicals no apparatus necessary, no special talent or experience re- quir Outfit furnished, free booklet. Tangley Company, 127 Main, Muscatine, Iowa. SEX Books for Adults. Illustrated catalog, 4c. Smetana & Co, Owosso, Michigan. GENUINE Cow-hide Brief Cases: 3 Pocket, $5.00. Splendid Xmas Gift. Thomas Mfrs. Sales Co., Kennett Square, Pennsylvania. TATTOOING Supplies. Learn the game. Catalogue 10c. Prof. Waters, 1050, Randolph, Detroit. MR. ADVERTISER: Ask to-day og a copy of the “Quick-Action Advertising Rate Folder.’’ It contains some really important facts which he ‘anane interesting and valuable to you. It also tells “‘How You Can Use Popular Science Monthly tenia © " - You'd like to know, wouldn't you? Manager Classified Advertising, Popular Science Monthly, 235 West 39th Street, New York.

PHOTOGKAPHY AND SUPPLIES

FILMS developed 5c roll, gg 8c each. Photo Service, 929 McMillan, Cincinnati, ‘Ohio MAIL us 20c with any size film for development and six velvet prints. Or send six negatives any size and 20c for six prints. Or send 40c for one 8 x 10 mounted enlarge- ment. Prompt, perfect service. Roanoke Photo Finishing Company, 212 Bell Avenue, Roanoke, Virginia. HAVE You A Camera? Write for free sample of our big magazine, showing how to make better pictures and earn money. American Photography, 156 Camera House, Boston, 17, Massachusetts. HIGH GRADE Amateurs only, send us 25c. with first roll. Pay a little more and see the difference. Priddy Photo Co., Columbus, Nebraska. KODAK films—any size, developed, 10c. Prints 4c and up. Quality. work. Trial order solicited.. Machiel’s Studio, Benton, Ill, ATTENTION—Send your favorite Film os RY and 35e for sample 1922 Calendar handtinted. AZ-U-LYK-M Photo Service, Bristol, Vermont.

PHONOGRAPHS, RECORDS, ETC.

BUILD your own phonograph. ‘Perfection’ highest quality — and electric motors, tonearms, reproducers cabinets finished or knocked down. Pre-war prices. New illustrated catalog and building instructions shee. Federal Supply Company, Indianapolis, Indiana. BUILD a genuine Choraleon Rronosraph and save over half. Big profit building and sell We furnish motors tone-arms, full instructions and all necessary parts. Send for catalog and free blueprint offer. Choraleon Phono- graph Co., 1121 12th St., Elkhart, Indiana. PHONOGRAPH parts: Complete finished cabinets $23.00 and up. Electric Motors Complete $21.00. Spring motors complete $11.00 and up. Tone-arms $2. ma and up. Columbia and Emmerson records 39c each. Li

Quick-Action Advertisements continued from page 10 invigorating value of ELECTRICITY. Here is ELEC Brushes Pain Away—From Head quick for ur 30 day trial offer! and without an electric connection of any kind! Stop eaters with pains. being bothered by falling hair and pimply complexion in: jays trial offer, and introductory price. McKinlay, Stone & Mackenzie, Sole American Distributors, Dept. 1412 30 Irving Place, New York

1] Wonder Electric Generator Brushes Pain Away-From Head # foot 3o days TRIAL fortfeallh Every physician knows and recommends the wonderful a eurtiv, » healing, and in its most plessant form—no shock, no pain. Just the right amount for best home-use results. An entirely new invention—NO BATTERIES—NO CORDS—NO ELECTRIC CONNECTION OF ANY KIND. Positively makes its own elec- tricity by pressureofyourthumb. Unique! Economical! Wonderful in its results, Wonder Flectric Generator } :rsze::-e258 ure to use the a. and enjoy the relief and quisting sensation o: ft hardday’s work’’ to F oot a ‘W.. Mont. “Name on request) > **T have used It to relieve an old lady Amazing Health and Beauty Treatments of sciatica, and she is now w able to Try this new Wonder Electric Generator 30 days Free. Thousands have been sold in foreign countries, now made and sold here at a bargain price. Let it brush your pains away from head to foot! See how it relieves rheumatism neuritis, headaches, colds, constipation! See how it beautifies the hair and stimulates the scalp. Watch it mprove your skin. See how it invigorates your entire body, making you feel younger, stronger, more energetic. Write walk with freedom some pa R. J. (Name on request) FREE New Book and Just mail the coupon or postal card at once! Get our new book explaining Wonder Elec- ts of the body. Read about this remarkable in- tig Generator treatments for a eat MAICES ELECTRICITY. without batteries, <S* _ Send me your Free Book and Sole A mericun Distributors AM Dept. 1412, 30 Irving Place,N.Y. Stop © 3u Days’ Trial Offer on the d out what the , . . cs Wenner Electric enerater has done for others. rite TODAY for special Wonder Llectric Generator. 30

Company, Dept. 7, Port Huron, Michigan. BUILD your Phonograph. ‘Perfection’? high quality spring and electric Motors, Tone Arms, Reproducers, wonderful results. Big saving. New catalog and building instructions mailed for ten cents. Hoosier Manufacturing & Supply Co., Phonograph Supply Dept., 316 Baldwin Block. Tediensnalte. Ind.

BOOKS AND PERIODICALS

6 DIFFERENT, interesting, clever publications, pre- Ppsid to any address only 25c. Publishers’ price $1.50. All current issues. Satisfaction guaranteed. Walhamore Com- pany, Lafayette Bldg., Philadelphia, Pennsylvania. PERSONAL Power Books. They reveal your latent possibilities, impart health, happiness and success. Sample copy 35c. Mutual Supply’ Co., Bradford, Pennsylvania. BOOKS. _ All kinds. Lists. Higene’s, K2441 Post Street, San Francisco.

MUSICAL INSTRUMENTS

VIOLINS, deep, mellow, soulful—on credit. Easy terms for wonderful instruments. Get details today. Gustav L. Henning, 2424 Gaylord St., Denver, Colorado. MR. ADVERTISER: Ask to-day for a copy of the “‘Quick-Action Advertising Rate Folder.’’ It contains some really important facts which will prove snierenes and valuable to you. It also tells ‘How You Can Use Popular he ag —— ae: ” You'd like to \ yout ager Classified Advertising, Popular ba rea Gathly. 2 235 West 39th Street, New York.

CIVIL SERVICE| are good for life. Many men and women needed for Postoffice| Biers, x. ee, Railway M ail, Rural aoe Postmaster, Customs, Revenue and other Departments.’ With the aid of our HOME STUDY COURSES you can quickly prepare for one of Shas’ attractive gestions. Our aye~ tem of instruction, adopted by U. S. Gov. schools all over-the country, is easy, rapid, and sure of results. Write today for full information. CHICAGO CIVIL SERVICE COLLEGE, Lock Box 226-X, Chicago, Il. SSSA DAME TIRES PORWR

Small Motors, Transform-' ers and Electromagnets By H. M. STOLLER, B.E., M.S. Unique, giving typical complete detailed designs and actua if construc*ion methods. Practical, tells how to rewind used motors for changes in voltage, speed, frequency, etc. Aaa, yet simply written, and fe ppc pend valuable for the amateur, repair man and elec- trical engineer. 328 pages Price, postpaid, $3.10 POPULAR SCIENCE MONTHLY 225 West 39th Street, New York City Quick-Action Advertisements continued on page 12

You Gan KNOW all about AUTOS, TRACTORS, AEROPLANES, STARTING and LIGHTING SYSTEMS, STORAGE BAT- TERIES, VULCANIZING, etc. Valuable Book FREE “*How to Succeed in the Automobile, Tractor and Aeroplane Business,” gives much new and very useful inforthation also tells all about the many selendid 2dvantages and practical training vou can get at this college in a few weeks. Tear this out and write fora copy, F REM, today. C15 1-4 30 010) eS OF AUTOMOTIVE ENGINEERING Dept.50Y 202H §,. Wabash Ave. CHICAGO

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steerer mtn epee Ce ee tna tise ateri gst nehsnieveomblaene SOT T abet. ~~ a ee ee ee t. 12 Quick-Action Advertisements continued from page 11 RA KES mecianicac BOOK They Will Raise Your Pay— Order on 5-Day Trial

The books listed below will perfect you in your chosen trade—pave the way to the big positions. Written in non-technical language—easy to read and understand. Every book covers its subject completely. An entire course of practical instruction and information condensed into one volume. Drake books make it unnecessary to wade through a big set of books to get the information you want. Your choice sent postpaid—you benefit 5 days—money refunded in full if not entirely satisfactory. Order direct from this page. Automobile Books Automobile Ignition, by Manly.. ene $2.00

Seer 2.00 Painting Books Beeches’ Automobile Handbook...Leatherette 2.00 Scene Painting and Dalietin Sees Soh 24.00 es - Car, Truck and Tractor, WF as, — sw ato: Ca ie ee 5 Sara . Ang ieee’. ee ee sik enhanc kee Cloth 4 startin ng and Li mig RL yaamg ae ~~ Ci, eee 5 ‘ i ...-Leatherett 4. and Repairs, by Manly......... f Sicnie'e Richckets sigs ee eR eee : "Cloth 1-50 Automobile wh hag Care and Repair, | eet aaa Mod Painter's Cyclopedia. ..........- Cloth 2.00 Manly........--.seeesseseoees : Amesheblle Peintinn a itt . cia ba eheak —— 1.50 Automobiie enennees -_ pega ~~ a — “oa ee See Cloth 1.50 Tires and Vuicanizing. by Tufford....... Cloth 2.00 New Hardwood Finishing |. 150 Gas and Oil Engine Handbook.......... Cloth 1.50 The Amateur Artist 1.50 Automobile Upkeep and Care, by Manly. Cloth 1.50 MPMEMNNE or ee oe Ee sa aan 125 Motorcycle Handbook, by Manly....... oth 1.50 Electrical Books Slide Rule and near LeathereticS2. 00 ania BACK Practical Applied Electricity....... $2.00 syandbook for Te .Cloth 2.00 GUARANTEE Alternating Current... ........... 4 Machine Shop Practice....... Cloth 500 Wiring baprams end Decriptions.. 5p epengnicel Drawing ond Moctis . 4, , Mark on thiepegeths Electrical Tables and Data... ...... $0 ae... MEPPEE peeeeneee Cloth 1.50 send in, with » a ag rmature a agnet Winding..... J cote og Modern Electrical Construction... .. .50 Business, Languete and paid. If not vee? el Electricians’ Operating and Testing. 38 Reference Books tory return in five days Motion Picture Operation. ......... 59 Better Business Letters, Leatherette. $1.50 money will Drake's Electrical Dictionary...... 1.50 etter Business English, Leatherette 1.50 promptly refunded. Electric Motor, Direct, Alternating.. 1.50 etter Advertising. ..... Leatherette 1.50 hich books will help Drake's Telephone Handbook... .. . 1.50 French without a Teacher..... Cloth 1.25 you? Mark them now. odern American Telephony ....... 2.00 Spanish without a Teacher....Cloth 1.25 a ~~ eyes and clephooe £1.25 German without a Teacher... .Cloth 33 BIG CATALOG Telegraphy Seif-Taught |: :// ‘Cloth 1.28 Everyday French......---- eats Everyday Spa’ ] FREE Finger Prints Simpli! — ae -caeee 2 = Shop Practice Books fox Ulesor “ae omg ee “ ne Glo th 1.50 Man more Home Sheet Metal Workers’ Manual, Elementary Chemistry....... Cloth 1.50 pan "Helps fully de- SD. 5 45 bine obo yk ele aie $2.00 Comosete Courses in Civil Service, _ "= our new Oxy- ~Acetylene Welding and Cutting, (| SSeS a -50 boo sent free. SEND ee re eee 1.75 Standard Cyclopedia of Recipes,Cloth 1.50 TODAY. FREDERICK J. DRAKE & CO., Publishers, 1003 Michigan Ave., Chicago Drake Books are For Sale at all Book Stores

Can’t Buy It! NEW YORK CITY July 8th, 1921.

Dear Mr. Liederman: Six months ago I was a physical wreck, on the verge of tuberculosis. I had tried numerous doctors but none of them seemed to do me any good. One day I met a friend whom I had always envied because of his marvelous physique, and asked him why he had been gifted with such a strong body while I did not have the strength or ambition to enjoy any pleasures in life. “‘Gifted nothing," said he. “*I got this by work." He then told me how he had taken your course in physical training and made himself the man he was. This was my Start. I wrote you at once and ere long noticed the complete change in my physical make up. I am now 22 pounds heavier, never know a sick day and feel as though I could lick my weight in wild cats. My boss has also noticed my ability to accomplish bigger things and I have had my salary advanced three times, making a total increase of 60%. I would not change places with my former self for a million dollars. Yours for bigger things, OSCAR MOFFITT. Where Do You Fit? ae you satisfied with your present condition? Do you start each day full ~ 3 and ambition? Do you feel the thrill of vitality surging through your Are you proud of your physical make-up? If not, get busy, steam up mid acquire it. It is a possession that money cannot buy. But if you have the spark of manhood in you, you will jump in and get it. What I Promise if you are sincere in your endeavor and ready to follow my guidance, I guarantee to completely change you in one month’s time. My course will continue on for months, but inside of thirty days your own friends will not know you. Your arm will increase at least one full inch and your chest double in proportion. Your shoulders will broaden and your whole body fill out. You will have the spring to your step and the thrill of life that only an athlete knows. Come then and try me out and make me prove it—I like it.

EARLE E. LeDEnane Send for my new book “The ee nes 4 ohyeleat “MUSCULAR DEVELOPMENT’? IT IS FREE! It tells the secret, and is hontramely illustrated with 26 full-page photographs of myself ; best athletes whom I have trained, also full particulars of my ile GOOE ane nee ot the wet splendid offer to you. - The valuable book and splendid offer == ee ee ee ee ee ee ee ee ee oe will be sent you on receipt of only ten cents, to cover wrapping and mailing. Sit right down now and fill in the coupon. Perhe l EARLE E. ‘Sate Dept. 1312, 305 Broadway, N. Y. City sooner you re started on the road to health and strength the easier it will be to reach perfect manhood. Don’t drag along ] Dear Sir:—I enclose herewith 10 cents, for which you are to send me, without any obligation on my one day longer—mail the coupon to-day. ; — whatever, a copy of your latest book, ‘‘Muscular Socdnasen ” (Please write or print plainly. ) Dept. 1312, 305 iced .«<iNew mE Teun bn Cine ae TREAT

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Popular Science Monthly LANGUAGES

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AUTHORS—MANUSCRIPTS

WRITE for newspapers and magazines. Big pay. Experience unnecessary, details free. Press Reporting Syndicate, 400, St. Louis.

WRITERS: Have you a song-poem, story, photoplay, to roe a! — manuscript now to Music Sales Company. ouis

WRITERS: Stories, poems, plays, etc., are wanted for publication. Literary Bureau, 117, ‘Hannibal, Missouri.

FREE to writers—a wonderful little book of money- making hints, suggestions, ideas; the A B C of success- ful story and "play-writing. Absolutely free. Just address Author's Press, Dept. 15, Auburn, New York. $$$ FOR IDEAS. Photoplay plots accepted Pan A form; revised, criticised, ¢ opyt yrighted, marketed. Advice free. niversal Scenario orporation, m904 Western Mutual Life Bldg., Los Angeles. OPENINGS for Profitable and Interesting Work as Special Correspondent for Motor Magazines. Report races, contests, automobile shows, etc. Make good money in spare time. Need not interfere with your regular occu- pation. Send ——- stating e, education and present position, and enclose 2 5 cents for yooklet * ‘The Profession of Opportunity,” containing detailed information. Auto- aes ge Bureau, Post Office Drawer 397-S, Loudon- ville, 0.

SCENARIOS published free. With name as author and rights protected. Vern Steves, Del Monte, California AMBITIOUS writers send today for Free Copy, Amer- ica’s leading magazine for writers of Photoplays, Stories, Poems, Songs. Instructive, helpful. Writer’s Digest, 636 Butler Bidg., Cincinnati. AUTHORS—Learn to write articles and stories. Send ten cents for valuable bulletin. Capital Literary Bureau, Lock Box 513, Department P, Madison, Wisconsin.

MUSIC AND SHEET MUSIC

CORNETISTS, Saxophonists, Trombonists, Clari- netists: Send for Free Pointers on Weak lips—High Tones, Low Tones, Staccato, Jazzing. Mention instrument. Virtuoso School, Buffalo, New York.

WRITE the words for a song. We revise Le ee = music and guarantee to secure publication. Submit on any subject. Broadway Studios, 121C Fitzgerald Building, New York. WRITE a Song agg Mother, Home, Comic or any subject. I compose music and guarantee publications oa words to-day. Edward Trent, 631 Reaper Block, hicago. WRITE the words for a song. We will compose music, secure copyright, and print. Submit poems on any sub- ject. Seton Music Company, 920 S. Michigan Avenue, Room 112, Chicago, Illinois. SONGWRITERS! Learn of the public’s demand for songs suitable for dancing and the opportunities greatly changed conditions offer new writers, obtainable only in our “Songwriters Manual & Guide” sent free. Submit al ons 4 : oe at once for free criticism and advice. Wer compose music, secure copyright and tncilivate t ay tublication or outright sale of songs. Knick- erbocker Studios, 315 Gaiety Building, New York. SONG WRITERS—Send for my free pamphlet, ‘‘Song Writers’ Secrets." Ethwell Hanson, Room 607, 3810 Broadway, Chicago. SONG-WRITER’S Booklet Free—A wonderful in- structive booklet, ‘‘The Song-Writer’s Guide” sent abso- lutely free. Submit Boy aaa song- qeeme We write music, print, yright. he Metropolitan Studios, Room 21, 914 8 South? Michigan Avenue, Chicago. WRITE the bd Sy for a Song—We write music, copy- right and endeavor qt - romote popularity and outright sale. Bell Studios, 1940 Broadway, Dept. 711, New York. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.’’ It contains some really important facts which will prove a and valuable to you. It also tells “‘How You Can Use Popular Science Monthly Profitably.’’ "You'd like to know, wouldn't you? Manager Classified Advert Popular Science Monthly, 225 West 39th Street, New York.

MOTION PICTURE BUSINESS

or ore Wanted. Big prices paid. You can write We show 3° how. Free particulars. Rex Publishers: ‘Box 175, F 43, Chicago.

WRITE Photoplays; $50 each. Experience unnecessary; details free to beginners. Producers’ League, 194, St. Louis.

PHOTOPLAY writers earn thousands. Be e; become successful. Learn at home, easily, wa eaggy 7 As “iitle cost, tg Ke ~~ write Friedman Company, 5014M Vernon,

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$3000 to $5000 a Year—Cinematography (The Science of Motion Pictures) Pt: Fascinating; Remunerative. Prospectus Free. merican Institute of Cinematography. Inc., Suite 4-A, eanenne Hall Bidg., Chicago, Tilinole. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains ‘some really important facts which will. prove interesting

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=~ s Oonerlinrna ebal re7Tl om FPS | December, 1921 REAL ESTATE—FARM LANDS PECAN and Orange Orchards on the Gulf. Easy terms. Big quick returns. Dept. C, Suburban Acres Company, Ocean Springs, Mississippi. WANT to hear from party having farm for sale. Give particulars and lowest price. John J. Black, 174th Street, Chippewa Falls, Wisconsin. $350 Gets ‘‘Security’”” Farm, 20 Acres Edge Village, 12 acres productive tillage; pasture, wood, timber, fruit; 5- room house, barn, poultry house. $700, only $350 down. Page 48 Catalogue Free. Strout Farm Agency, 150 BH Nassau St., New York City. FOR INVENTORS 900 Mechanical Movements, also illustrations explain- ing 50 Perpetual Motions. book, Inventor’s Uni- versal Educator, Fifth Edition, tells how to procure and sell patents. Government and other costs. Covers the matter from A to Z. 160 pages, elegantly bound. Con- tains noted decisions of U. S. Supreme and State Courts on Patent Cases. Mechanical Movements greatly assist inventors—suggest new ideas that may prove of great aid in perfecting inventions. Tells how to select an Attorney. Has valuable information regarding Patent Sharks. Selling Agents and Brokers. Price $2. Postage Free everywhere. Fred G. Dieterich, 681 Ouray Building, Washington, D. C. PATENTS—Write for free Guide Book and Evidence of Conception Blank. Send model or sketch of invention for free opinion of its patentable nature. Highest refer- ences. Reasonable terms. Victor J. Evans & Company, 106 Ninth, Washington, D. C. HE G. & G. Manufacturing Company, 3116 Spring Grove Avenue, oer. A, Cincinnati, Ohio. yo Ma- chinery, Models, Dies, Patterns, Tools, Metal Stampings, Gears, Contract Manufacturing. PATENTS—Send for free book. Contains valuable in- formation for inventors. Send sketch of your invention for Free Opinion of its patentable nature. Prompt service. (Twenty years’ experience.) Talbert & Talbert, 436 Tal- bert Building, Washington, D. C. INVENTORS, before disclosing your ideas to others write for our ‘Evidence of Disclosure’ form. Send sketch or model of your invention for examnaition and advice. Ask for free book *‘How to Obtain a Patent.” Avoid danger- ous delays. Write to-day. Merton-Roberts & Co., 121 Mather Bldg., Washington. D. C. PATENTS Secured. Prompt service. Avoid danger- ous delays. Send for our ‘“‘Record of Invention’’ form and Free Book telling How to Obtain a Patent. Send sketch or model for examination. Preliminary advice without charge. Highest References. Write today. J. L. Jack- son & Co., 121 Ouray Bldg., Washington, D. C. HAVE you a practical invention to sell outright or piace on royalty? Send details to Adam Fisher Mfg. Co., 83A, St. Louis, Missouri. MODELS and Experimental Work of every description. Lamson Model and Experimental Works, 625 West Jackson Boulevard, Chicago. I SELL Patents. Established in 1900. Scott, 773PS, Garson Avenue, Rochester, N. Y. PATENTS—Trademarks. Before disclosing an inven- tion, the inventor should write for my blank form ‘‘Evidence of Conception.’"” This should be signed, witnessed and re- turned to me with sketch or model upon receipt of which I will promptly render opinion as to patentable nature and send booklet on Patents. Highest references. Prompt attention. Reasonable terms. Clarence A. O’Brien, as P imams Lawyer, Woodward Building, Wash- ngton, D. C. Charles A. INVENTORS—Will buy outright or arrange to manu- facture on liberal royalty basis, patented or patentable inventions which meet our requirements. Principal parts should be of brass or steel and adaptable to screw machine production up to’one inch in diameter. Complete factory fully equipped with going organization for both manufac- ture and sales. Submit models or drawings with complete description. F. H. Wellington, 1055 Riverside Drive, South Bend, Indiana. WE sell patents. Write for information P.‘O. Box 1081, San Francisco, California. PATENT ATTORNEYS PATENTS—Herbert Jenner, Patent Attorney and Mechanical Expert, 622 F Street, Washington, D. C. I pi ! &@ patent can be had and its exact cost. Send . Jor circular. PATENTS—lInventors should write for our book ‘‘How to Obtain a Patent,’’ which contains valuable information which every inventor should have. If you will send us a sketch, model or photograph of your invention we will promptly make search of the Patent Office records and advise you whether or not your invention is in our opinion Patentable; our charge for the service being $5.00. With an experience of over twenty years we feel that we are fitted to render you prompt, efficient service which will merit your confidence. Moderate charges. Write to-day. Talbert & Talbert, 435 Talbert Bldg., Washington, D. C. PATENTS. Booklet free. Highest references. Best results. Promptness assured. Watson E. Coleman, Patent Lawyer, 624 F Street, Washington, D. C PATENTS—Write for free illustrated Guide Book and Evidence of Concepticn Blank. Send model or sketch of. invention for free opinion of its patentable nature. Highest references. Prompt attention. Reasonable terms. Victor J. Evans & Company, 155 Ninth, Washington, D. C. ROBB, ROBB & HILI. offer a strictly professional service to manufacturers and inventors in patenting inven- tions and registering trade-marks, a service which is the result of twenty years’ experience. Write for free booklet and names of prominent manufacturers and inventors represented by us. Send sketch for om advice. 840 McLachlen Building, Washington, D. C. 1336 Hanna Building, Cleveland. LACEY Patent-Sense. ‘‘The book the inventor keeps.” Free. See page 116 PATENTS promptly procured. Send disclosure of in- vention, design or trademark for actual search of U. 8. atents and novelty report. Validity and infringement nvestigations. Patent and trademark suits prosecuted and defended anywhere in the United States. clients appreciate my efficient service. No literature will be sent you as this is a professional service. Individual and personal. Specific information and advice given regarding each individual case. Specialize in prosecution of pending cases that have been previously rejected by the Patent Office. Specialize also in unfair competition litigation be- fore the Federal Trade Commission. George P. Kimmel, aster of Patent Law, 38N, Loan and T ' Washington, D. C. d Trust Building PATENTS, Trade Marks, Copyrights. Prompt, per- sonal, reliable service. Over 30 years’ active practice. Write for terms. Book free. Address E. G. Siggers, Box 1, N. U. Building, Washington, D. C. “INVENTOR’S Guide” free on request; gives valuable ietermation and advice. Frank Ledermann, 15 Park Row, Quick-Action Advertisements continued from page 12 13 GUIDES SENT FREE FOR YOUR OK ‘OK: ‘‘Worth ten times their price.”’ ‘‘l wouldn’t send them back for a handful of diamonds.”’ ‘‘I con- gratulate you on their excellence.’’ ‘‘Helped me to two raises in four months.”’ ‘‘Better than a school of instruction.” ‘Studied them when I was laid up and got further ahead than if I’d been on the job.”’ These are the words of grati- tude that come to us by every mail from Electrical workers, There is no short cut to genius. But there are sign posts all along the road to success. Hawkins Electrical Guides find these sign posts for you. It is so easy to pay Ai} for the Guides that you will scarce- / ly miss the monthly payments. IW HAWKINS ELECTRICAL ny GUIDES Do you want to know the facts about the follows ing electrical subjects? They are all covered in Hawkins Electrical Guides. Electrical signs and symbols—static and current electricity— primary cells — con- ductors and insulators —resistance and conduc- tivity— magnetism — in- duction coils — dynamo principles—classes of dyna- mos — armatures — windings —comniutator brushes. Motor principles—armature reaction— motor starting — calculations — brake horsepower—selection and installation of dynamos and motors — galvanometers — standard cells— current measurement — resistance measurement — voltmeters — watt- meters—watt-hour meters—operation of dynamos — operation of motors. Distribution system—wires and wire calculations — inside, outside and underground wiring--sign flashers— lightning protection — rectifiers — storage battery systems. Alternating current principles — alternating cur- Zz Z NY cs | / nating current systems—switching devices—circuit breakers—relays —tightning protector apparatus— regulating devices—synchronous condensers — bene epi devices —meters—power factor indicators — wave form measurement — switch boards. Alternating cur- rent, wiring power stations—tur- bines; management, selection, location, erection, testing, run- ning, care and repair—telephones. Telegraph — simultaneous tcele- graphy and telephony—wireless —electric bells—electric lighting photometry. Electric railways— electric locomotives—car lighting —trolley car operation — mis- cellaneous applications — motion pictures — gas engine ignition — automobile self-starters and light- ing systems, electric vehicles. Elevators—cranes — pumps —air compressors — electric eating, electric welding — soldering and brazing—-industrial electrolysis— rent diagrams—the power factor— electro- alternator principles — alternating plating — construction—windings. A.C. Motors electro- , —synchronous and induction motor therapeu- 4700 j, _ principles—A. C. commutator motors tics — X- PICTURES ‘4 —induction, motors, transformers; rays * losses, construction, connections, 3 tests—converters —rectifiers. Alter- PAGES Also a complete 126-page ready reference index of the complete library. This index has been planned to render easily accessible all the vast information contained in the 10 Electrical guides. There are over 13,500 cross references. You find what you want to know instantly. FREE SEND NOvn. ox su ane SEND ONLY THIS COUPON Examina- | M Oo N E Y THEO. AUDEL & CO., Coupon | 72 Fifth Ave., New York City Please submit me for free examination, HAWKINS ELECTRICAL GUIDE (Price $1 each). Ship at once prepaid, the 10 numbers. If satisfactory, I agree to send you $1 within seven days and to further mail you $1 each month until paid. Flexible Covers Pocket Size Occupation........- CE A ee eee ’ Employed by......scecccecccrsccceceeeeeseres ° Home Address.......+s++e+0+ Decnnkiacenes coe Quick-Action Advertisements continued on page 14

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ef Sn Rt ae eae meg ete rene a parr rome ee — 14 ois ‘ : a ee es, pea: =. ——. SBA $100 a Week! He doubled his pay and now enjoys the comforts and pleasures of a real income Why not double your pay? Thousands of our students have done it and thou- sands more will do it. You can be one of them. Do not think for a moment that it is luck or pull which brings suc- cess and real money—far from it. It is preparing for the big opportunity and knowing what todo when the right time comes that does it. The men who have made successes for themselves were ready when their main chance came. Your main chance, too, will come, Are you ready for it? Remember the Empty Lot? The older fellows were playing ball and you were watching, wondering if you would ever get a chance to play. You knew if you only got a chance you day they hollered, “Come on, kid, grab a bat!” Your chance at the pill had come. That is the way with life. Your chance at the pill will come, but if you want to stay on the team, you will have to deliver the goods—and that you can do only if you are prepared. The big ees the permanent job go to the man ows.” You Can be the Man “Who Knows” We will show you how. Without loss to you of a single working hour, we can show you a sure way to success and. big pay. A a number of men in each of the posi- tions listed are enjoying their salaries because of our help. We want to help you. Makea check on coupon against the job you want and we will help you get it. Write or print your name on the coupon and send it in today. AMERICAN SCHOOL Dept. G-975, Drexel Ave. and 58th St., Chicago AMERICAN SCHOOL job checked. «Architect eee LQWy! ... Building Contractor wba Automobile Engineer ~...Photoplay Writer .... Automobile Repairman «-Mechanical Engineer ....Civil Engineer «..Shop Superintendent ... Structural Engineer --..mployment Manager ....Business Manager «-..5team Engineer ...Cert. Public Accountant .....Foremanship ...Aceountant and Auditor ....Sanitary Engineer ....Bookkeeper ....Surveyor (& Mapping) i ‘illness andDesigner ..... Telephone Engineer ..--Blectrical Engineer ....Telegraph Engineer =e Electric Light & Power ....High School Graduate ....General Education ....Fire Insurance Expert Name Address.. would show them. Sure enough, one Dept. 6-975, Drexel Ave. and 58th St., Chicago Send me full information on how the PROMO- TION PLAN will help me win promotion in the Bae ol Shop Practice Quick-Action Advertisements continued from page 13 PATENT. Trade-mark and Copyright specialist, Prompt, personal and efficient service. Advice on request. M. E. Jones, Lawyer, 509C 7th Street, Washington, D. C.. INVENTORS, send sketch or model of your inven- tions for opinion, concerning patentable nature and exact cost, of a plying for patent. Book, ‘How to Obtain a Pat- ent,’ Gives information on patent procedure and tells “ee every inventor should know. Established twenty-eight years. Chandlee & Chandlee, 427 Seventh Street, Washington, D. C. INVENTORS before disclosing your idea to others write for our “Evidence of Disclosure’ form. Send sketch or model of your invention for examination and advice. Ask a A ag ~~ **How to Obtain a Patent.”” Avoid dangerous Jrite to-day. Merton-Roberts & Co., 120 Toker Bide. Washington, D. C. PATENTS. My fees in installments. Advice book free. Frank Fuller, Washington, D. C. ee MILLER, Ouray Building, Washington, D. C., patent attorney, “mechanical and electrical expert. Best ‘quality of work and results. Moderate charges. INVENTORS—Send for form “Evidence of Concep- tion” to be signed and witnessed. Form, fee schedule, information free. Lancaster and Allwine, 232 Ouray Building, Washington, D. C. PATENTS procured—trade marks registered—A com- prehensive, experienced, = service for the protection and development of your Preliminary advice gladly furnished without charge. Booklet of information ad ag for disclosing idea free on a Richard B. Ow 44 Owen Building, Washington, D. C., or 2276-Z Weolworth Building, New York. PROTECT your rights. Write for “Record of Inven- tion’ which contains form to establish evidence of concep- tion of your invention. Prompt rsonal service. Pre- liminary advice without charge. J. Reaney Kelly, 612-P Columbian Building, Washington, D. C. “INVENTORS’ Record” and “Bulletin’’ sent without charge. My free blank form for disclosing your invention simplifies procedure. Send sketch or descr ption for pre- liminary advice. Wm. H. Mulligan, Registered Attorney, 396 Woodward Building, Washington, D. C. PATENTS, prompt, personal, efficient service by an Ph sis. -at-law skilled in all branches of Patent practice. Over 12 years’ actual experience. Full information on > P. Fishburne, 333 McGill Building, Washing- ton, D. PATENTS. Prompt, personal, efficient service. Over 15 years’ actual experience in various branches of Patent Practice. Send sketch, model or photos and description. Lynwood B. James, 392 McGill Blax.. Solan D.C. PATENTS procured. Trade-marks registered. Reason- able fees eodore Willis, oe ane Patent Attorney, Munsey Bldg., Washington, D. GET Your Own Patent. $35 Complete. Application blanks and full instructions $1. Cooper Cutting, Camp- bell, California. epg ed mm. you have an invention and don't want to spend unnecessary money in securing a patent, write to Inventors * Engineers Consulting Co., P. O. Box 344, Washineton, D. C. PATENTS—Trademarks. Before disclosing an inven- tion, the inventor should write for my blank form‘‘ Evidence of Conception.’’ This should be signed, witnessed and re- turned to me with sketch or model upon receipt of which I will promptly render opinion as to patentable nature and send booklet on Patents. Highest — Prompt attention. Reasonable terms. Clar A. O'Brien, seeamnared Patent Lawyer, Woodward Building, Washing- on, D. ATENTS—Edward C. Sasnett, Attorney at Law and former Principal Examiner in the United States Patent Office; Electrical and Mechanical Expert. Personal service guaranteed. McGill Building, Washington, D. C. PATENTS Secured. Prompt service. Avoid danger- ous delays. Send for our ‘Record of Invention” form and Free Book telling How to Obtain a Patent. Send sketch or model for ee. He 4 — i = e. ighest Refere' ri 3 Jack- Co., 222 Ouray Bi Bide. “Washington, D. AGENTS AND SALESMEN WANTED AGENTS make 500% profit handling Auto Monograms New Pictures, Window. tters, Transfer Flags, Novelty Signs. Catalog Free. Hinton Co., Dept. 125, Star City, Indiana. MAN in each town to refinish chandeliers, brass beds. automobiles, by new method. $10 daily without capital experience. Write Gunmetal Company, Avenue “fF,” Decatur. Tilinois. MAKE $314 Monthly selling patented vest-pocket wind- shield cleaner; Firins made this first month; one rub keeps entire windshield clear 24 me: chemical-felt; enameled mountings; guaranteed one year; sells $1. Security Mfg. Co., Dept. 361, Toledo, Ohio. GENTS—Make a dollar an hour. Sell Mendets, a R, patch for instantly mending leaks in all utensils. Sample package free. Collette Mfg. Company, Dept. 467, Amsterdam, New York. BEGINNERS—Complete Mail Order System Book. Box 1005, Atlantic City. AGENTS make 140% oe. Rw yy 0 Crucifix shines in the dark. Sells for $2.00. Costs 84c. Complete line religious en, | Crucifixes, bulbs, switch plates, house numbers, match boxes. ~——— Ornamen- tal! Useful! Every home a Pine Pioneer ig sales. Get Free Demonstration Outfit. he ee. «corporation, 1263 W. 63rd St., Chicago, Illinois IF you are now selling twisted wire brushes, toilet articles, mops or household specialties, you should carry our side line. Sanitax Hair Brushes, etc., do not conflict with any other line. Splendid profit makers. Sanitax Brush Co., 2352 Wabash Avenue, Chicago. SALESMEN for Patented Cigar Lighters and Cigar Case Moisteners. Sell to Cigar Stands everywhere. Thou- sands in use. —ome or side line. Start now. Drake Mfg. Co., Dept. P., Milwaukee, Wisconsin. BIG Money and Fast Sales. Every owner buys Gold — for his auto. You charge $1.50; make $1.35. Ten orders daily easy. Write for particulars and free samples, American Monogram Company, Dept. 47, East Orange, New Jersey. PATENTS. Write for Free Illustrated Guide Book. Send sketch or model for free opinion of its patentable nature. Highest references. Prompt attention. Reason- oh terms. Victor J. Evans & Co., 174 Ninth, Washington, GENTS: Big profits. Best and cheapest window laters made. Easily applied. Dime brings five samples. Earviomars free. Staibrite Company, 115 Second Avenue, w Yor a AGENTS, Mail Order Men, get this new Ripper. ’ ‘Shuts Caribert up like a knife, uses razor blades. Sample, 30c. Co., Berrien Springs, Mich. Quick-A ction Advertisements continucd on page 15 Popular Science Monthly WE'LL TRAIN YOU } | as Drafting Specialist F- REE EARN $35 TO $100 A WEEK After you have completed our Course in Drafting (mechanical drawing), we will give you free training in your choice of one of our courses in a specialized branch of drafting. WHAT YOU GET FREE We also furnish you free with complete drawing and drafting equipment when you enroll in our Course. Free consultation privileges at any time, during your course or after you've taken your posi- tion. We bh help you to get a position as draftsman and send ou free subscription to Draftsman’s Pu lication * ‘The Compass.” FREE BOOK: Write to-day for free book, “Your Future in Drafting,” fivins details of our home study course in drafting and telling how ree can qualify for & position paying $35 to $100 a wee. ROY C. CLAFLIN, President COLUMBIA SCHOOL OF DRAFTING Dept. 1573, 14th and T Streets, N. W., Washington, D. C. “STAMMERING) ~~ Ifs Guise and Gire > (use and dire You can be p auiehty cured. Send 10 cents for 288 Page cloth bound book on Stammering and a ing. It tells how I cured myself after Stammerin: and Stuttering for 20 years. BENJAMIN N. BOGUE 685 Bogue Building, 1147 N. fll. St., Indianapolis. S| cs Business Courses ctaaat Yagtcan papotane' let aacias Beet ea sonal business Our enabl train aged when btehe ence with spare your presen duties. Give Dam mark with Iciow’ the Tied of post ryt nd of position errs regarding our low cont month. payment ey ee ae ‘Tear ont, mark and i a mail the coupon today. you. Find gu tbent thane LaSalle Broblem Method.” wat us step has helped thousands of ambitious men to real Dept.1283-R Chicago, Ill. o— to mba ne ree wording course ia indicated CLaw—Degres of LL.B. CiBasincss Died, ee eae DlEtfective Efficiency OBusinessLetter-Writing Name. Present Position Adéress OExpert Bookkeeping )zweesce lode jQm logs 142

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'e ye 1g ir e, ‘i= in ir or 1f2 G2 December, 1921 “RADIO” Luminous Paint—Makes any article visible in the dark. Guaranteed. Bottle 50 cents coin. Illuminant Company, 5428LP Rice Street, Chicago. FORDS run 34 miles per gallon on cheapest gasoline or half kerosene, using our 1922 carburetor. Increased power; styles for all motors; attach yourself. Money back guarantee; 30 days trial. Big i to agents. Air Friction Carburetor Co., 3222 Madison St., Dayton, Ohio. 56 MILES per gallon made with new patented gasoline Vaporizer. Write for particulars. Vaporizer Company, Pukwana, South Dakota. $15.00 DAILY selling the New Amberoid Unbreakable Combs; kind you can hit with a hammer; write for whole- sale price. J. Bucknam, Box 2792, Boston, Massachusetts. MAKE $100 weekly selling Rolly’s Washday Wonder. New chemical dirt solvent. Harmless. Cleans without rubbing. Want Agents and crew Managers. Free samples dl Particulars. Rolly Chemical Co., K8, Hastings, ebraska. MAKE $25 to $50 week representing Clows’ Famous Philadelphia Hosiery, direct from mill—for men, women, children. Every pair guaranteed. Prices that win. Free book “‘How to Start” tells the story. George Clows Com- pany, Desk 24, Philadelphia, Pennsylvania. GET our plan for monogramming automobiles, trucks, hand luggage and all similar articles by transfer method; experience unnecessary; exceptional profits. Motorists Accessories Company, Mansfield, Ohio. AGENTS and portrait men. Crew Managers. We give you more for your money. Better and quicker service. Lowest prices on frames and glass. Rejects credited. Catalog free. The Pioneer Corporation, 1263A West 63rd Street, Chicago. GALLAHER made $336.00 one week selling guarantee ' Collection Systems used by all business men. Sayers Mfg., 2831 Sheffield, Chicago. SOAP agents: big profits. Sample FREE. Bestever Products Co., 1941-T12 Irving Park, Chicago. SELL Minitmend for tires and tubes—cost 2c. Repair: surpasses vulcanizing, saves 500%. Every auto and accesse ory dealer buys. Profits amazing. Shaw made $21 first day. Hart $155 first week. Particulars and free sample. The Continental Rubber Co., Dept. 88, Philadelphia, Pa. WORLD'S fastest selling auto accessory! County dis- tributors wanted; write to-day. G. L. W., Spring Oiler Co., San Diego, California. SALESMEN—Earn $3,500 to $10,000 a year. City or traveling. Experience unnecessary. Quickly qualify through our amazing system. Free a agg ae service to members. Send for salesmanship book, list of lines and full particulars. National Salesmen’s Training Association, Dept. 126W, Chicago, Illinois. AGENTS: Sell rich looking 36x68 imported rugs, $1.00 each. Carter, Tenn., sold 115 in 4 days; profit, $57. You can do same. Write for sample offer and selling plan; exclusive territory. Sample rug by parcel post — $1.39. E. Condon, Importer, 12 Pearl Street, Boston, Massachusetts. KEROSENE Burners for Furnaces, Cook and Heating —. Economy Mfg. Company, 616 West Monroe, cago. AGENTS, $60 to $200 a week. Freesamples. Gold Sign Letters for Store and Office Windows. Anyone can do it. Big demand. Liberal offer to general agents. Metallic Letter Co., 431A N. Clark Street, Chicago. AGENTS! 1921's Greatest Sensation. 11 piece toilet article set selling like blazes at $1.75 with $1.00 dress- maker's shears free to each customer. Get lined up for Christmas rush. E. M. Davis Co., Dept. 57, Chicago. BIG profits easy. Duplex Transformers needed on every auto. Save gas. Easily sold. - Exclusive distributors wanted. Jubilee Mfg. Co., 14 Sta. C, Omaha, Nebraska. $10 WORTH of finest toilet soaps, perfumes,: toilet waters, spices, etc., absolutely free to agents cn our refund plan. Lacagsian Co., Dept. 615, St. Louis, Missouri. EVERY man needs it. Every man you sell starts an endless chain of boosters. Send twelve cents for samples of new back collar button, retailing ten and twenty-five cents. Money back guarantee. Puritan Mfg. Co., 215 Fifty Associates Building, Toledo, Ohio. SENSATIONAL—Opportunity. One sale a day means 00 per month! Five sales, $1,000 per month! Mar- velous new adding machine. Retails $15. Work exes $350 machine. Adds, subtracts, multiplies, divides, automatically. Lightning speed. Errors impossible. Five-year guarantee. Used by U. S. Government and est corporations. ‘Tremendous demand everywhere. Amazing profits. Write quick for trial offer and protected territory. The Lightning Calculator Company, Dept. O, Grand Rapids, Michigan. EARN $2.00 an hour in your spare time taking sub- scriptions for this magazine. Write to-day for the agency in your town. Popular Science Monthly, 225 West 39th Street, New York. EASY, pleasant work for mechanics, shop men, clerks, during spare hours, will add many dollars to their salaries. Also want ms who can give full time. Big wages assured. ovelty Cutlery Company, 27 Bar Street, Canton, Ohio. AGENTS—Best seller; Jem Rubber Repair for tires and tubes; supersedes vulcanization at a saving of over per cent; put it on cold, it Vulcanizes itself in two minutes, and is guaranteed to last the life of the tire or tube; sells to every auto owner and accessory dealer. For particulars how to make big money and free sample, address Amazon Rubber Co., 504 Amazon Building, Philadelphia, Pennsylvania. AGENTS for to-day’s best selling accessory. Nifty leaf spring oilers, oils your.springs, stops squeaks and breaks; makes Fords ride easy. 100% profit. Sample Ford set of four for $1.50 and agents’ proposition. Springcup Co., Schmid Bldg., St. Joseph, Missouri. LARGE profit on small investment. Lettering by Transfer Method. Auto Monogram Supply Co., Green Street, Newark, New Jersey. STOP Making the Other Fellow Rich! Manufacture and sell these goods yourself from Miller's Guaranteed Manu- facturer’s Formulas. Enormous profits—Investment sm —Business quickly established. Stamp brings detailed descriptive literature regarding Magico Windshield Cloths; Amazon Rubber Repair, Launderite Stoveoil, es, Mexican Yucca Soap, Food, Automobile House- hol ialties in all lines, and other valuable literature. ier coming Chemist (Old Reliable Established 1897), z AGENTS—Steady Income. Large manufacturer of Handkerchiefs and Dress Goods, etc., wishes representative in each locality. Factory to consumer. Big profits, honest goods. Whole or time. Credit given. Send for par- ticulars. Freeport Mfg. Co., 24 Main St., Brooklyn, N. Y. ‘ AGENTS—200% _ profit. Wonderful little article; something new; sells like wildfire; carry in pocket; write at 1) for Free Sample. Albert Mills, General Manager, 5183 American Building, Cincinnati, Ohio. i -7 Quick-Action Advertisements continued from page 14 Be An “Electrical Expert” L. L. Cooke } ; Chief Engineer Chicago Engineering Works tee : nes LECTRIFICATION is sweeping the country. In homes, factories, shops, farms, railroads—everywhere—it is fast becoming the one great source of power. Ten years from now practically everything now driven by steam, horse or water power will be controlled by electricity. This means that the greatest opportunity of your life is staring you square in the face. Men are needed, badly needed, right now—many more will be needed almost imme- diately to boss the big Electrical jobs that are projected. The men who boss these jobs are going to draw real pay— “Big Pay.” But they will be trained men—‘“Electrical Ex- perts’”’ who know electricity from the ground up. Don’t let this great opportunity slip. Decide today to fit yourself as an Electrical Expert, ready to take your place in this Big-Pay field, ready to Earn $12 to $30 a Day That’s the kind of pay you want to see bulging your pay envelope. And you can! Why should you plod through life in a long-hour-small-pay, no future job, when you can jump to success and big-pay in Electricity? A few short months training under me, through my easily- learned, quickly grasped, sparetime, home study course in Practical Electricity and you too can step into a big-pay job in this fascinating field. I Back You— Guarantee Your Success As Chief Engineer of the Chicago Engineering Works, a million dollar institution, I know exactly the training you need to succeed as an “Electrical Expert." My course in Electricity is simple, thor ough and complete—no big words, no useless theory, no higher mathee matics—just plain everyday, straight-from-the-shoulder English. I know that you can learn Electricity under me, in fact,I guarantee it, for if you are not entirely satisfied, I will return every cent paid me. There’s no chance for failure with me. Free Electrical Save $45.50— Working Outfit Enroll Now To make your success still more yA yada ra ae ag = can ae é A .50 on the already low price o certain I give you tools to work = iny course. But you must act at with—a splendid big outfit of once. Write to-day for full par- tools, materials, instruments and —— and my big FREE book, supplies — real apparatus with ow To Become An_ Electrical : : Expert.” It’s the first step which you can do practical work. towards bigger pay. L.L. Cooke. CHier ENGINEER Cricaso Encincerins Works INCORPORATED Dept. 3y 1918 Sunnyside Ave., Chicago, Ill. a ee L. L. COOKE, Chief Engineer, Chicage Engineering Works, Dept. 3y, 1918 Sunnyside Ave., Chicage, I'l. Dear Sir: Send at once Sample Lessons, your Big Book, and full particulars of your Free Outfit and Home Study Course—all fully prepaid, without obligation on my part. The Cooke Trained Man is the ‘Big Pay Man Quick-Action Advertisements continued an nane 16

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at A A nasal PEI a, al Ni IIe He Sep Th I ACI EE ee —_ so ey Solnetererer -- ee ee ee ee Sh AS Sot 7 2 wha RS Sot Sn 16 Quick-Action Advertisements continued from page 15 Wanted! Men to Hill These $5000-aYear Positions A Great New Field as Yet patheant: of ad Most Men OUNDLESS oppor- tunities lie before the men who are willing to qualify for positions paying from $2,500 to $5,000 a year and more in this new profession. It seems in- credible to the aver- age man that thousands of splendid jobs are actually going begging for lack of men to fill them. Transportation is to-day the second largest and most important industry in the country. Freight charges amount to a million dollars an hour—over four billion dollars a year! Yet it is estimated that eight out of every ten shippers are losing money. Thousands of dollars are lost daily because few men actually know the most economical methods of shipping. The Traffic Profession—only about ten years old— was created when the Government passed an amend- ment to the Interstate Commerce Law. This made it necessary for about 1,000 railroads—60,000 large business concerns, nearly 450,000 smaller shippers— thousands of Chambers of Commerce and Commer- cial Clubs, State Railway Commissions, and the Interstate Commerce Commission to employ men with a technical knowledge of Traffic Management. A Need for Trained Right now 100,000 trained Men That Has Never traffic men are urgently Been Satisfied needed. Every large con- cern must maintain a traffic department—employing scores of men. A Boston concern employed a competent traffic man who saved $9,751 in two weeks. Another traffic expert compelled an Eastern Railroad to refund $122,000 to the Meeker Coal Company. A New York Traffic Man saved his company $24,000 in one year. Is it any wonder that firms are glad to pay large salaries for skilled traffic-men? A Detroit Traffic Manager receives $19,500 a year. A Cleveland man gets $24,000. Thousands of good traffic jobs pay from $2,500 to $5,000 and $10,000 a year. The trained expert in this new profession plays a most important part in his firm’s business in Aeentnnty Until a asy Way to ° Train fora short time Big Job ago, there was no simple way for the aver- age man to become a Traffic Manager. But now the American Com- merce Association, a national organization of Traffic Men, offers to pre- pare men to handle the problems of shipping. It has already helped hundreds to big positions as Traffic Managers. This training is given during spare time, at home. Once a member of this great association, you receive the help of its Advisory Traffic Council, made up of traffic men of national reputation. An Interesting To give the whole story the Asso- Book Free for ciation has prepared a remarkable the Asking book, “Opportunities and Require- ments for Traffic Work.” This book explains how anyone can quickly qualify for the important job of Traffic Manager. It. cites many stories of success by members of the Association. After reading it, you will understand why $5,000 sala- ries arecommon and why thousands of jobs pay $2,500 to $10,000 a year and more. Write to-day for this wonderful book—no cost or obligation —just mail coupon below. Address: American Commerce Asso- ciation, Dept. 1412, 4043 Drexel Blvd., Chicago, Ill. —s-— = oe oe ee a oe oe ee ee ee ee ee eee oe eee o— eae ew American Commerce Association, Dept. 1412 4043 Drexel Boulevard, Chicago, II. Pleass send your new free book on ‘‘Opportunities and Requirements for Traffic Work"’ without obligation to me. I have had previous traffic experience........ no traffic experience........ NE cs nnn Bape SERRA AEM A SAS SRS SSOP RAS NR EEN REE Sais sxock eto eh sh Re pASA hes ¥ en Geese eweses oy eee SOO MISO yok sve scice eeu Can You Manage Production? Production must be managed. Men, material, equipment must be understood and di- rected by trained men. As industry launches itself up- on a great drive against waste, the doors of the nation’s 200,000 producing plants are open to the Industrial Engi- neer today as never before. Industrial Engineering is being taught according to the university plan to thousands of men who are destined to fill the big, executive, managing jobs in industrial organizations. Many of them have already increased their salaries from 200% to 400%, all the way from $2,000 to $25,000 per year men. No man with industrial inclina- tions has a right to expect a great- er opportunity. Get the whole interesting story with the coupon below. OSG OE OP a a a Ge eee ees os oe oe ! Industrial Extension Institute 1 9 West 45th Street, New York City : SE a ek A ee aie, 3 . Address (Pop. Sci. Mo., Dec., 1921) Na ersiesienene sav ca exes 085 taken ene nko ste ims sama er ee Catalogue on Request National College of Chiropractic 16N. Ashland Blvd, Chicago Dlste Scent Chiropract ea- cation. Distinguished 5 amc esi bei nt "Esc ear term. 14th Year This Man Earns $83 a Day His name is J. F. James. He left school when he was a boy. He was down. but he refused to stay down. He worked! He studied! And today he is president of the Mascot Stove Com- any, of Chattanooga. Tenn.. at a ge of 25,000 a year! He says that the I. C. S. “‘made his success possible.” Won’t you let the I. C. S. help you, too? When everything has been made so easy—when so many other men are going forward to success—can you afford to let another priceless hour go to waste? The way is easy. Without obligation or a penny of cost, mark and mail the coupon today and let us tell you how you, too, can win advance- ment and more money through spare-time study at home with the I. C. S. -_————— TEAR OUT HERE — — — — — — a CORRESPONDENCE SCHOOLS Box Scranton, Pa. Explain cae el your Course in the subject marked X DRAFTING Electrical Eng’in Pduetiine Mechanical Stationary Salesmanship urveying OHEMISTRY Bookkeeping Civil Engineering AUTOMOBILES Civil Service ARC RE STENOGRAPHY Mail Service Name. Street Address City. State Quick-Action Advertisements continued on page 17 Popular Science Monthly DISTRICT Managers wanted for tremendously suc- cessful new office specialty. Two minute demonstration means sale. Wonderful repeater. mine for you. Gol Perfection Mfg,, 123 So. Fourth, Philadelphia, Penn- sylvania. SELL necessities. “Business Guide.”’ for sample. ville, Illinois. Everybody needs ane buys the Bryant cleared $800 in July. Send It's free. Nichols Company, Box 1B, Naper- WOLVERINE cloth polishes all metals. Sample and particulars free. Manufacturer, 404-E, Sun Building, Detroit, Michigan. OFFICE Necessity. Costs 25c, sells $1.00. Big repeater. Agents coining money. Acidproof Ink Co., Philadelphia, Pennsylvania. CAPITALIZE your spare time easily and pleasantly. Make $10.00 where you now make $1.00. No experience aor ~~. necessary. Stacey, 4020 Crutcher Street, e MR. ADVERTISER! Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells ‘‘How You Can Use Popular Science Monthly Profitably.” You'd like to know, wouldn't you? Manager Classified Advertising, Popular Science Monthly, 225 West 39th Street, New York. TOWLINES. Small. Guaranteed. See advertisement under AUTOMOBILES ACCESSORIES. Superior Manufacturing Company. AGENTS—A new invention. Harper's fibre broom and ten-use brush set. It sweeps, washes and dries upstairs windows, scrubs porch ceilings and does seven other things. Big profits; easy seller. Free trial offer. Harper Brush Works, Dept. G, Fairfield, Iowa. MAKE 600% profit. Free samples. Lowest priced gold window letters for stores, offices. Anybody can do it. ge demand. Exclusive territory. Big future. Side line. Acme Letter Company, 2800 N. Congress, Chicago. 17 CENTS Brett on every 25-cent sale means big daily profits. Box 500, Shreveport, La. FREE Sample. ‘Rain Shield Wiper.” buys quickly. Retails $1.00—Costs you 25 cents—(300%. Profit). No mechanical attachment—no cloth. One ru keeps windshield clear 24 hours against rain, snow storm. Wonderful side ay Rg od in ket. ‘Only 1 free sample given away in your town urry, write for yours’ NuLife Auto (M) Aid Corporation, Hartford, Connecticut- COIN money selling Neverwet Shoulder Strap Water proof Aprons. yA woman buys. Best on market. We manufacture and ship direct. Get details to-day. A. E. a sae) Manufacturing Company, 413 Locus’ Street, Philadelphia. AGENTS coining money selling Universal Gas Savers for every gas stove. Wonderful device. Cuts gas bills in Every Autoist half. Increases heat. Popular prices. = Profit. Exclusive territory. Write quick. B. D. Moore, Gas Saver Company, Topeka, K ansas. EVERYBODY eats every day—You can handle Sugar, Flour, Canned Goods, Dried Fruit, Coffee and entire line of groc eries, as well as Paints, Roofing, Aluminum Ware and Automobile Oils, with no a to By, no money invested; take large orders from samples. oods are guaranteed and proven quality. Selling experience not necessary. Steady. profitable work for ‘‘workers.’’ Address, Hitcheoek- Hil = , Dept. 220, Chicago, Ill. Reference: Any Bank o xpress Co. AGENTS Wanted—Something New—Fire Fighter sells y. Makes a spectacular demonstration; car owners, homes, pity fyi ractically buy on sight. Our ag make $10. a day; exclusive territory. If u wish to es tation @ business of your own with unlimited possibilities for making big money, write us today. Fyr- Fyter , 109 Fyr-Fyter Bidg., Dayton, Ohio. We want men and women who are desirous of making $25.00 to $200.00 per week clear: profit from the start in a —— business of their own. Mitchell's Magic farvel Washing Compound washes clothes spotlessly clean in ten to fifteen minutes. One hundred other uses in -—_ home. Ry else like it. Nature’s mightiest cleanser. tains no lye, lime, acid or wax. Fastest selling article. ever sold through agents. Free Samples make sales easy. Enormous repeat orders. 300% profit. Exclusive territory. We guarantee sale of every Dackage. No capital or experience required. Baker, pate, made $600 last month. You can do as well. Send for Free au and proof. L. Mitchell & Co., Desk 301, "1308-1314 61st, Chicago, Illinois. A Good Seller. Queens, New York. CALIFORNIA Buckskin Mend ing without thread. Recommended by housewives every- where. Splendid sideline. Attractive proposition and sample free. Norman Ovri, East San Diego, California. AGENTS simply coin money with newest, greatest household article ever put out. Every woman wants this article as soon as she sees it. Every home a prospect for one to a dozen. Saves food,—saves time,—saves money. Forty per cent commission on all sales. Be first in your territory. Make big money. Write now for full par- culars. The Aridor Company, 586 E. Illinois Street, hicago, Illinois. HIGH class specialty salesmen covering one or more States with spare time to interview other salesmen. Big money with us. Credentials or no answers. Confidential. Rickey Co., 6157 Wentworth, Chicago. MAKE Money at home making toys—we show you how. Send 50c (no names) for complete working drawings and instructions. Dekalb Designing Co., tur, Georgia. FREE Sample of quick selling patented specialty. Live Wire salesmen, get yours now. Also details of wonderful $5,000-year opportunity. Agents wanted everywhere. H. G. Martin. 51 Cliff St., New York. AGENTS: If you are making less than $300 a month, our proposition on Sentinel Burglar Alarms for windows and doors will interest you. Many agents earn $20 daily. Brand new inventions. No wires or batteries. Instant y attached to any door or window. No competition. vides cheap burglar insurance. ae or makers. Write to-day for extremely liberal terms to agents. Sentinel Alarm Co., 1452 Marquette Bidg., Chicago, Illinois. . SELL Food Products. Everybody has to eat. Strictly high pte. | 3 prices. Steady work—good profit. Sample Consumers Supply Company, 601 Con- sumers Bldg, * Portland, Michigan. MILLER made $225 one week selling Guaranteed Busi- ness Producer. Douvle Dispey meta en letter sign for stores, worth $5, sells $3, one Bit. 0.pos tpaid. Write Currier Mfg. Co., Minneapolis, M ADVERTISER: Ask to-day for a copy of the “Quini- Action Advertising Rate Folder. It contains scme md important facts which will prove interesting dv: a. It also tells .* ‘ou Can Use Science Monthly Profitably.” you'd like to know, wouldn't ‘you? Manager Classified Advertising, fFopular Sc.ence Monthly, 225 West 39th Street, New York. A decent income. Precition Co. Tissue repiairs cloth- eee ema tees | (Nea (Oe OS = Oe «(Ofte 61S) (6LID>E 1B

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————— December, 1921 AGENTS: Everybody uses extracts. Sell Duo Double Strength Extracts and complete line Household Necessities. Products used constantly. = repeaters. Write today. DUO Co., Dept. E66, Attica, New York. SALES District Managers wanted for Dominant Polish, the new wonder that is being — everywhere. if you have small capital, we can make you a remarkable offer, one that will put dollars in your pockets while you are making cents now. Exclusive Territory granted. Dominant Products Co., 163 South Street, New York City. AGENTS—Clever Invention! Inkspoon makes every nafountain pen. Fast office seller; big profit, demand ncreasing everywhere. Exclusive territory offered. =" free. H. Mauri Company, Tribune Building, New ork. ATTRACTIVE openings for men and women who have time to build up a permanent and lucrative business of their own. No experience necessary. Sell protection against death and loss of income from accident and sickness, $7,500 death benefit, $25.00 weekly, costs $10.00 yearly. Other amounts in proportion. Guaranteed income from renewal commissions. Easily sold, all occupations insurable at one rate, no confusing classifications. Over $1,000, .00 Resources, established 1886. North American Co., 308 Walnut St., Philadelphia. AGENTS: We pay $6 a day taking orders for New Kerogas Burner. its any stove. burns coal oil. No ex- perience or capital required. Work spare time or full time. Write for demonstrating sample. Thomas Mfg. Co., Class 2661, Dayon, Ohio. 100% PROFIT selling Three-in-One Holder. New pat- ented, small, universally useful article. Very fast seller. Ribbon Steel Products Corporation, 1211 Engineering Building, New York. BE independent. Work for yourself. Sell auto special- ties. Make real money. Particulars free. Fadenrecht’s Chemical Works, Corn, Oklahoma. MONEYMAKING Books, Plans, Formulas. Catalogs Free. Ideal Book Shop, 5501-P, North Robey, Chicago. SEND for free sample Fretnot Washday Wonder. Be convinced you can do a whirlwind business. Constant re- peater with large profits. You take no chance. We posi- tively guarantee sale. P.S. Motter & Sons, 20 E. Jackson Boulevard, Chicago. POIMET Polishing Cloth cleans all metals. Retails 25c. Sample free. F.C. Gale, 15 Edinboro Street, Boston. GENUINE Buckskin Gloves direct from factory, $3.95. Made from selected skins. Agents wanted. Quaile-Angus Co., Desk (36), Gloversville, New York. PREPARE and Market Your Own Products—Master formulas; manufacturing processes; trade secrets; com- mercial information. Particulars free. The Thaxly Co., Dept. 11, Washington, D. C. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.” It contains some really important facts which will prove interesting and valuable to you. It also tells “‘How You Can Use Popular Science Monthly Profitably.’’ You'd like to know, wouldn't you? Manager Classified Advertising, Popular Science Monthly, 225 West 39th Street, New York. HELP WANTED OUR genuine gold window sign letters are an excellent money-making proposition for handy men. Slann Sign System, 7505 St. Antoine, Detroit, Michigan. MEN—Age 17 to 45. Experience unnecessary. Travel, make secret investigations, reports. Salaries, expense. American Foreign Detective Agency, 321, St. Louis. SILVERING mirrors, French plate taught. Easy to learn, immense profits. Plans free. Wear Mirror Works, Excelsior Springs, Missouri. MEN wanted to make Secret Investigations and reports. Experience unnecessary. Write J. Ganor, Former Gov't Detective, 115, St. Louis. WRITE Photoplays; $50 each. Experience uunecessary ; details free to beginners. Producers’ League, 194, St. Louis. $135 Month. Railway Mail Clerks. Hundreds wanted. Steady. List positions free. Write immediately. Frank- lin Institute, Dept. S42, Rochester, New York. BIG Money Made Silvering Mirrors, metal plating, refinishing. Outfits furnished. F. Decie Laboratories, 286 Fifth Avenue, New York. DETECTIVES Earn Big Money. tunity. Travel. Fascinating work. Excellent oppor- Experience un- necessary. Particulars free. Write American Detective System, 1968 Broadway, New York. GOVERNMENT Clerks Needed Soon (men—women), $1600-$2300. No experience required. Write Mr. Ozment, former U. S. Government Examiner, 295 St. Louis, Mo. MEN to represent corporation by interviewing business men at home or travelling. Nothing ts sell. Equipment furnished you free. Earnings from $2000 to $9000. yearly. Popular 3509 White Plains Ave., New York. BE a detective. Excellent opportunity, good pay, travel. Write C. T. Ludwig, 424 Westover Bidg., Kansas City, Missouri. : BE a Mirror Expert, $3-$10 a day; spare time at home first; no capital; we train, start you making and silvering mirrors, French method. Free prospectus. W. F. Derr, Pres., 579 Decatur Street, New York. BE a Railway Traffic Inspector! $110 to $250 monthly. expenses _ after 3 months’ spare-time study. Splendi opportunities. Position guaranteed or money refunded. Write for Free Booklet Cm-13. Standard Business Train- ing Institute, Buffalo, New York. Quick-Action Advertisements continued from page 16 Become a Motor Expert Learn Autos in Washington —— BN zs, fi — " Trained me- chanics earn $150 to $400 a month and many are earn- ing $5,000 to $10,000 and a year in THEIR OWN BUSI- NESS. We fit you in our New school to MAKE REAL MONEY in 6 to 8 weeks. Careful anthorities es- timate that more than ONE BILLION DOL- LARS were spent in 1921 for the care and re- pair of the nine and one- quarter MILLION mo- tor vehicles registered in the United States. If you are one of the millions who has been out of a job this year, or if you are dis- satisfied with your earnings, get into the trade that knows no lay-offs—a trade that pays big money all year round. Marvelous $250,000 Schools Our new $250,000 Schools have every equipment and apparatus for successfully teaching you. E. H. Cooley, our Vice- President and CHIEF INSTRUCTOR is a designer of motors, an electrical engineer, as been in charge of machine shops, has taught electricity, and is one of the most thoroughly informed inspectors in the country. Learn Through ACTUAL WORK Our method of teaching puts you on the actual kind of work -that you will have to do when you are in a garage or repair shop working at wages of $150 to $400 a month. Our complete instruction INCLUDES transmissions, engine assembly, starting and lighting systems, carburetion, welding, Catalog and Book of Views of Washington cutting, forging; in fact, we teach you ALL that you MUST know if you are to be rated as a first-class auto mechanic. Earn BIG Money as an Auto, Truck, Tractor Airplane Mechanic FREE SPECIAL LIMITED $ TITIE Tuition Rate To quickly en- roll one thousand "400 students we have ra alelal ial made a very LIB- ERAL REDUCTION from our regular rate. We reserve the right to withdraw this offer at any time. HERE is YOUR OPPORTUNITY to learn to be an auto mechanic and visit and see Washington at the same time and at a very low cost. Decide to make the trip that you have always wanted to make and to learn the trade that you have always wanted to Jearn. Train for inde- pendence, prosperity and success NOW. Come to Washington. FRE Before you decide on ANY school ANYWHERE BE SURE TO READ OUR CATALOG. It contains just the information you MUST have before you can decide fairly for your own best future. EARN 150 1612-1622 U St. “Washington Views.” eoercccerseceseeseseseeesesseesee New Catalog and Book of Views of Washington DO YOU LIKETO DRAW? Cartoonists are well paid We will not give you any grand prize if you answer thisad. Nor will we claim to make you rich ina week. But if you are anxious to develop your talent with asuc- send a copy of this picture, with 6 cents in stamps for portfolio of cartoons and sample lesson plate, and let us explain. The W. L. EVANS SCHOOL OF CARTOONING 825 Leader Bids. Cleveland, Ohio FIREMEN, brakemen, baggagemen, $140-$200. Colored rters by railroads everywhere. Experience unnecessary. 38 Ry. Bureau, East St. Louis, Illinois. STOP daily grind. Start silvering mirrors, auto head- lights, tableware, etc. Plans free. Clarence Sprinkle, Dept. 95, Marion, Indiana. HAVING sold 150,000 of a household appliance in New England we are ready to make general offer whereby direct salesmen are now Le ae ge | $45 weekly. No capital required. Unique method of obtaining interviews. Op- portunity for District Management. The Reeves Com- pany, 53 Broad Street. Milford, Connecticut. WANTED: Representatives to handle household neces- sities. Grand opportunity to work way through Elms Commercial College. Students Aid Sales Department, Newark, New York. BUILD a Sign Business. Experience unnecessary. Send $1.00 for sample sign, your neme embossed, informa- tion. Impress Sign Company, 202-B, District National Bank, Washington, D. C. By Emanuel Swedenborg the following works of receipt of 15 cents per book ; Divine Providence - - 629 pages The Four Doctrines - 635 pages Divine Love and Wisdom, 618 pages Room 754 3 W. 29th STREET Quick-Action Advertisements continued on page 18 HEAVEN and HELL) ELECTRICITY: "(i IN3MONTHS / bee Intensive, in- ELECTRICAL EARN BIG PAY Grides a practical in- struction in 3 test and best uipped trade anos! aster Craftsmen oiwage at your side to guide you. This book of 632 pages, or any of Sweden- borg, printed in large type on good paper, well bound in stiff paper covers, will be sent, prepaid, on The American Swedenborg -Printing and Publishing Society New York demand for trained electricians now, Come to the COYNE SCHOOL! money learning. Free t Department Serv- Beer ee wctive Course and Complete fo ness. mt to students ep- now in our Complete Course. No extra cost; no extra time. Chicago offers & won- derful opportunity for recreation and study. for etl to Write he Big Today start et - once. Tradeend 39-51 E. litinols St., Chicago, ti. Dept. 3Y 17 MAIL THIS COUPON TODAY American Motor School, Inc., Dept. 212 N. W. Washington, b. Cc. Without cost or obligation, please send your catalog and eee

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CNEL sem satista's Paper eee sein ll Sita a tina 18 Quick-Action Advertisements continued from page 17 Trained Minds Win What Chance Has Yours ? 1 Chance for Success 9 Chances for Success 238 Chances for Success Thus does a great newspaper com- ment editorially on a recent report on industrial education made to theAmeri- can Society of Mechanical Engineers. Think what these figures mean! to achieve success. With only an elementary education, you have just one chance in 41,250 A high school education increases your chance nine ~ r. P the - Conditia Con “ducatign “tion 41° therg bo, wi times. With a college education, or its equivalent, you multiply your chance by 238. Only a few men out of every thousand can go to college or to a good technical school. The great majority must find some other way of getting a special education. The United Y. M. C. A. Schools furnish one reliable way of doing this through the use of spare hours without giving up present employment. Thousands of superintendents, foremen, department managers, engineers, accountants, salesmen, business executives, etc., owe their positions to spare-hour study under Y. M. C. A. direction. In the 240 United Y. M. C. A. Spare-Hour Courses there is one to fit your need. United Y. M. C. A. correspondence instruction gives you: (1) the most service for the least money; (2) careful guidance in selecting a course; (3) the personal, sympathetic attention of an earnest instructor, and (4) as much encouragement to complete your course as to begin it. During the last twelve months more than 140,000 ambitious young men have enrolled with the United Y. M. C. A. Schools. Advance with them! Don’t drudge along in poorly paid or distasteful work when the world is demanding trained heads, men able to take positions as leaders, who can create, execute and direct. Multiply Your Chances Of Getting Ahead Send this inquiry coupon. You will receive interesting details of the course of your choice, also a free copy of our new booklet ‘‘ Does Education Pay ?”’ po ---------------------------- UNITED Y. M. C. A. SCHOOLS, Dept. 8-D, 375 Lexington Ave., New York City — Building Construction —Business English —Business Law —Business Organization —Chemistry —Civil Engineer —Farm Management —Farm Motor Mechanic —Foreign Languages —Foremanship —Freehand Drawing —Highway Engineering Name and Occupation i Complete Address I am interested in the position or home-study course I have marked. Please give full information. | —Accountant —Civil Service —Illustrator —Advertising Man —Commercial Spanish —Locomotive Operation —Agricultural Courses —Concrete Engineer —Machine-Shop Practice —Applied Psychology —Dairy Farming — Mathematical Courses —Architect —Draftsman —Mechanical Engineer —Auto Mechanic —Electrician —Plumber ——.. —Electrical Engineer —Poultry Husbandry —Better Letters —English Courses —Radio Operator — Bookkeeper -—Factory Management -—Radio Engineer —Railroad Engineering —Salesman —Secretarial —Steam Engineer —Stenographer —Structural Drafting —Surveyor _ —Tool Designing —Traffic Management —Use of the Slide Rule 2. : Hicuer Epvucation; Co: in English, Spanish, Mathematics, Chemistry. Draw: ° tion, Business an ot me er are given by on pondence. any time. it | The Wniversity of C p3oth. Year Division35, Chicago, mi. | WANTED! RAILWAY MAIL CLERKS Examinations soon. $1600 to $2300 a year. Steady life-time job. Common education sesevep Sufficient. No ~ S - , ROCRB= Patterson Civil Service School, ‘@ sary. Mail cou- Dept. 1612, Rochester,N. ¥Y- % pon for Cata- 6 Sirs: Send me without charge your Catalog, describing this and other fine U. S. Government positions. DERM: vk hs > 6400b 0008 09:06000005 055408 Popular Handbook for Cement and Concrete Users A book of value to the concrete user, including kinds of cement employed in, construction, concrete architecture, in- spection and testing, waterproofing, coloring and painting, rules, tables, working and cost data. 430 pages, 126 illus. Price, $3.00 POPULAR SCIENCE MONTHLY, 225 W. 39th St., New York Our Scientific Method will stop that stuttering in anne og Panay A natura teed Tethod. & The Lewis School for Stammerers 56 Lewis Bidg., 71- ° Mich. you a better job. It for Catalog B, stating trade. We teach drafting. Be a Draftsman! Hore big train you quickly. Books and tools FREE. Write for Columbia Corr: School Est. 1904 Dept. 27, Drexel Bldg., Phila., Pa. Quick- Action Advertisements continued on page 19 Popular Science Monthly GOVERNMENT needs Railway Mail Clerks, $133 to $192 month. Write for free specimen questions. Colum- bus Institute, Columbus, Ohio. WANTED Men to prepare for positions as Mechanical- Draftsmen under personal supervision of Chief Engineer. Box 45, So. Gardner, Mass. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.’’ It contains some really important facts which will prove interesting and valuable to you. It also tells ‘“‘How You Can Use Popular Science Monthly Profitably.”’ You'd like to know, wouldn't you? Manager Classified Advertising Popular Science Monthly, 225 West 39th Street, New York BUSINESS OPPORTUNITIES SCHEMER Magazine, Alliance, Ohio, prints big profit schemes; one subscriber made $25,000 from three; an- other $10,000 from one. Try your luck. Year, $1.00; 3 months, 25c. USED correspondence courses sold, rented and ex- changed. List free. (Courses bought.) Lee Mountain, Pisgah, Alabama. SUBSTANTIAL manufacturing corporation wants capable men to establish branch and manage salesmen. $300 upward necessary. Will allow expenses to Baltimore as explained. Address, Secretary, 343 St. Paul Place, Baltimore, Maryland. EXPERT Chemst will furnish Formula and Trade, Secrets in all lines. Lists free. W.L. Cummings, Ph. D.. Gordon Avenue, Syracuse, New York. BE a detective. Excellent opportunity, good pay, travel. —— oy T. Ludwig, 424 Westover Bldg., Kansas City, ouri. CONVERT each spare moment into cash. My dignified methods, requiring no merchandise nor peddling, will enable you to increase your income, tremendously, without study, capital, experience, or delay. Robert Graham Stokey, Box 798, Dallas Texas. I MADE $25,000 with small Mail Order Business- Sample article 25c. Free booklet. Stamp. Alps Scott, Cohoes, New York. ENTER a new business. Earn $3,000 to $6,000 yearly in professional fees making and fitting a foot specialty; openings everywhere with all the trade you can attend to; easily learned by any one at home in a few weeks, at small expense; no further capital required; no goods to buy, Job hunting, soliciting or agency. Address Stephenson Laboratory, 15 Back Bay, Boston, Massachusetts. WE start you in business, furnishing everything. Men and women, $30.00 to $100.00 weekly operating our ‘‘New System Specialty Candy Factories’’ anywhere. Opportu- nity lifetime. Booklet free. H. Ragsdale Company, East Orange, New Jersey. DETECTIVES—Excellent cpportunity. Fascinating work. Experience unnecessary. Particulars free. Write American Detective System, 1968 Broadway, New York. WILL you sell us your spare time? We will train you to write show cards for us. No canvassing or soliciting; we supply you with steady work; distance no object; will pay you from $15 to $50 a week. Wilson Methods, Limited, Dept. C, 64 East Richomnd, Toronto, Canada. ° PATENTS—Book free. Send sketch for free Opinion of patentable nature. Talbert & Talbert, 437 Talbert Bidg., Washington, D. C. BUY and exploit practical inventions. Trade for prop- erty. Form companies. Sell county rights. Adam Fisher Mfg. Co., 183D, St. Louis, Missouri. PATENTS Procured—Trade Marks’ Registered—A comprehensive, experienced, - ompt service for the pro- tection and development of your ideas. Prelimnary advice gladly furnished without charge. Booklet of infor- mation and form for disclosing idea free on request. Richard B. Owen, 44 Owen Building, Washington, D. C., or 2276-Z Woolworth Building, New York. START a Magazine; capital $1; sample 10c. Cope, Box 233, Champaign, Illinois. OPEN hat and clothes cleaning parlor in home town. Wonderful opportunity. Big profits. Write Byron S., 27 Station I, New York. ADVERTISE—24 words in 80 weeklies, $3.00; each additional line of 7 words or less 75c. Lists free. Union Sales Co., 1325 Arch Street, Philadelphia, Pennsylvania. ARTIFICIAL Marble sanitary fiooring instructions. Ornamental casting. Concrete plaster. Garden furniture, Decorations. Statuary. Rubber,moulds. Electro-metal- lurgy. Particulars and illustrations free. Chris Mahler, Box 1122, Huntington, New York. START a pressing, cleaning and dyeing establishment, big profits, little capital. We tell you how. Write for Sostaet. Ben-Vonde System, Dept. E, Charlotte, North Carolina. MAKE and sell your own goods. 1,000,000 Industrial Receipts. Merchants, manufacturers, grocers, confec- tioners, medical, technical and practical trade secrets, rocesses in every business, 500 engravings, 1,016 pages. eavy cloth binding $3.00. P. Strobel Co., 943 Jefferson Ave., Cleveland, Ohio. A HIGH CLASS Man, able to finance himself, will be given a valuable exclusive sales contract for Renulife Violet RayGenerators for home use; nationally advertised, 35,000 in use. Splendid opportunity to build permanent, profitable business in this territory. Write Renulife Electric Co., 412 Marquette Building, Detroit, Michigan. NICKEL Plate automobile accessories, hardware, electrical parts. Big profits. Requires no capital. Simple battery process. Write to-day. Webster Engineering Co., Webster Groves, Missouri. DE $30a week home. French bread-making. 15 tr ae. Free booklet tells. Ashbrook, E. 67, Marengo, Ohio. ET’S swap! Buy! Sell! Whatd’ye got? Whatd'ye ant Dime brings results! Swap Bulletin, 1833 Bathgate Ave., Bronx. START a business in your kitchen. Mitchell, 1402 Winnemac, Chicago. N attractive proposition is offered persons desiring & better future. The Kotha Company, 2407 College Ave., Philadelphia, Pa. TO Amateurs in Towns of 100,000 or less: Listen—Are you interested in making money in your spare time? Write us, telling your age and standing with your local radio field. The information you furnish us will determine whether you are qualified to receive an interesting and reasonable propo- sition from us. Address Radio Dept. Federal Telephone & Telegraph Co., Buffalo, New York. Write Chas. — — . tw a owt an mae

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December, 1921 STAMPS AND COINS LIKE Triangular Stamps? To introduce our Sudden Service ae yy we'll send triangular Fiume, set China ships, large $1 United States revenue, also packet 50 foreign, millimeter scale, perforation gauge, ruler and bargain lists—for only 9c. Fennell Stamp Company, Department C, Fullerton Building, St. Louis, Missouri. CALIFORNIA gold $% size, 27c; $% size 53c. White cent and Catalogue, 10c. Normal’ Shultz, Colorado Springs, Colorado. 1000 different stamps, $3.00; 500, $1.25; 200, 20c; 100, 12c. Approvals. Michaels, 5602 Prairie, Chicago. CALIFORNIA Gold, quarter size and German 5pf 30c; Me and catalog 10c. Homer Shultz, Union Star, uri. 158 Genuine Foreign nee eee War Issues, Venezuela, Salvador and ia Service, Guatemala, China, etc., only 10c. Finest Approval Sheets 50% to 60%. Agents wanted. Big 72-p. Lists Free. We_buy stamps. Established 25 years. Hussman Stamp Com pany, Dept. 55, St. Louis, Missouri. STAMPS—500 different, $1.25; 300, 70 cents; 200, 25 cents; 100, 10 cents. List free. "Approvals, for reference. Elwood D. "Weber, 812 South Avenue, Plainfield, N. J. STAMPS, 20 unused. All Le ma 2 eents. Mention paper. Quaker Stamp Co., Toledo, O STAMPS—50 varieties, Africa, Brazil, Peru, Cuba, Mexico, etc., and Album =. 50 different U.S. 25c. 1,000 hinges, 10c. 1,000 mixed, 40c. List free. I buy stamps. C. Stegman, 5949 Cote Brilliante, St. Louis, Missouri. ENCH Colonials, 25 different, only 10c. Nickles, 122 Worde Avenue, Washington, D.C. 55 ALL DIFFERENT stamps, including China, Japan French Colonies, etc., given to applicants for our high gradé approval selections. Send references and 2c stamp to the gewood Stamp Company, Dept. M., Millford, Connecti- cut. OLD coins, large Fall selling catalogue of coins for sale, free. Catalogue quoting prices paid for coins, ten cents. William Hesslein, 101A Tremont Street, Boston, Massachusetts. 17 VARIETIES Bulgaria stamps, 20 cents. List of 7,000 low-priced stamps free. Chambers Stamp Company, 111C Nassau Street, New York City. TURKEY. 54 varieties, $1.00. Mouhib, 608 West 125th Street, New York. STAMPS—50 different Jamaica, Venezuela, etc., only 10c; 100 all different, 13c; 1000 all different, $4.52; 10 different, United States, 25c; 1000 hinges, 10c; 50% approvals with every order. List free. I buy stamps. L. B. Dover, Longmont, Colorado. 50 DIFFERENT Portuguese eee 40c. Browne, 11 Willow, Wollaston, Massachusetts. 25 Newfoundland, etc. Two cents. Harland Burgett Co., Lima, Ohio. . REPUBLIC of France—65 different for 25c. Jacob Fischer, 1539 North Lawler, Chicago. APPROVALS and packets, G. E. Labrie, 3254 Marshall Way, Sacramento, California. MR. ADVERTISER: Ask to-day for a copy of the “Quick-Action Advertising Rate Folder.’’ lt contains some really important facts which will prove interesting and valuable to you. It also tells ‘‘How_ You Can Use Popular Science Monthly Profitably."’ You'd like to know, wouldn't you? Manager Classified Agverting, Popular Science Monthly, 225 W West 39th Street, New York Statement of the Ownership, Management, Coeintien. etc., required by the Act of Congress of August 24, 1912, of Popular Science Te published monthly at New York, N. Y., for October 1, 1921. State of New York, County of New York, ss. Before me, a notary ——.. in and for the State and county aforesaid, personally ap . B. Capen, who, having been duly sworn accor —¥ to law, deposes and says that he is the Business Manager of the "Popular Science Monthly and that the following is, to the best of his knowledge and belief, a true statement of the ownership, management, etc., of the aforesaid publica- tion for the date shown in the above caption, required by the Act of —_ 24, 1912, embodied in scction 443, mag Laws and Regulati ons, printed on the reverse of this ‘orm to wit: 1. That the names and addresses of the vag editor, managing editor, and business managers are: lisher, The Modern Publishing x Company, Inc., 225 Woot Thirty-ninth pe Ry * W. Payne, 225 t Phlety-ainth Street, New York, N. Y. Managing Bator, Kenneth W. Payne, 225 West eg oo Street, New York, Y. Business Manager, oO. . 4 apen,. = West Thirty-ninth Street, New York, N. t the owners are: The P Popular Science Pubiishin Company, Inc., 225 West Thirty-ninth Street, New es Stockholders of Popular Science Pub- lishing Company, Inc., Henry J. Fisher, 22 wee atest New York, N. ¥.; Oliver B. Capen, 225 Wi — ninth Street, New York, N.Y.; Robert Cade Wilson 683 Spri: eld Avenue, Summit, N. J.; Waldemar Kaempf- fert, Fifth Avenue, .New York, N. x George Agnew, 22 William Street, ‘New York, N. Y.; Susan D. Bliss, 22 William Street, New York, N. Y. 3. That the known bondholders, mortgagees, and other security holders own- ing or holding 1 per cent or more of the total 9 of bonds. mortgages, or other securities are: O. Ridenour, New York, N. Y.; Samuel Insul, Chicago, ii 4. That the two paragraphs next above, giving the names of the owners, stockholders, and security holders, if any, contain not only the list of stockholders and security holders as they - upon the books of the company, but —_ in cases ere the stockholder or security Suse appears upon the books of the company as trustee or in any other fiduciary relation, the name of the person or corpora- tion for whom such trustee is act ing, is given; also that the said two paragraphs contain statements embracing afflant’s full knowledge ond belief as to the circumstances and condi- tions under which stockholders and security holders who do not appear upon the books of the company as trustees, hold stock and securities in a capacity other than that of a bona fide owner; and this affiant has no reason to believe that any other person, association, or corporation has any interest direct or indirect in the said stock, bonds, or other securities than as so stated by him. (Signed) O. B. CaAPEN, Business Manager. Sworn to and subscribed before me this 7th day of October, 1921. “Arthur A. Blauvelt, Queens Comey--1988, New York | County—101, New York Reg. 3 (Seal.) My commission expires March 30, 1923. Quick-Action Advertisements continued from page 18 19 His New Invention Finds and Corrects Your Mistakes in English! S the result of thousands of tests, Sherwin Cody found that the aver- age person is only 61% efficient in the vital points of English. Ina five min- utes’ conversation, or in an average one page letter, from five to fifty errors will appear. It is surprising to see how many experienced stenographers fall down in spelling such common words as “‘business,’’ ‘‘abbreviate,”’ etc. It is astonishing how many business men say ‘‘be- tween you and I” instead of ‘between you and me,’’ and use ‘‘who’”’ for ‘‘whom”’ and mispronounce the simplest words. Few people know whether to use one or two “cr ow “ar oo War whether to spell words with “ie” or ‘“‘ei’’ and when to use commas in order to make their meaning absolutely clear. A Remarkable Discovery Mr. Cody has specialized in English for the past twenty years. But instead of going along in the old way he has applied scientific prin- ciples to teaching. the correct use of our lan- guage. He made tens of thousands of tests of his various devices before inventing his present method: -In all his tests he found that the trouble with old methods is that points learned do not stick in the mind. In school you were asked to remember rules, and if you forgot the rules you never could tell what was right and what was wrong. For the past five years Mr. Cody has worked almost day and night to find a way to replace bad habits in writing and speech, with good ones. And as a result of his experience he evolved his wonderful new Self-Correcting Method Mr. Cody was granted a patent.on his unique device, and now he places it at your disposal. This invention is simple, fascinating, time saving, and incomparably efficient. You do the lesson given on any page, then you see exactly how Mr. Cody himself would correct it. You mark your errors and check them in the first blank column. Next week you try that page again, on the second unmarked sheet, correct your errors, and check them in the second column. You see at a glance what you have learned and what you have failed to remember, until you have reached the 100% point in spelling, punctuation, grammar, and expression. Only 15 Minutes a Day A remarkable advantage of Mr. Cody’s course is the speed with which these habit-forming practice drills can be carried out. You can write the an- swers to fifty questions in 15 minutes, and correct your work in five minutes more. You waste no time in going over the things you already know. Your efforts are automatically con- centrated on the mistakes you are in the habit of making, and through constantly being shown the right way, you soon acquire the correct habit in place of the incorrect habit. There are no rules to remem- ber. There is no tedious copy- ing. There is no heart-break- ing drudgery. New Book Free Every time you talk, every time you write, you show what you are. Your English re- veals you as nothing else can. When you use the wrong word, when you mispronounce a word, when you misspell a word, when you punctuate incorrectly, when you use fiat, ordinary words, you handicap yourself. If you feel your lack of Language Power, if you are ever embarrassed by mistakes, if you cannot command the exact words to express your ideas, our new booklet ‘‘How to Speak and Write Masterly English” will prove a revelation to you. Merely mail the coupén, and it will be sent by return mail. Learn how Sherwin Cody’s new invention makes com- mand of language easy to gain in 15 minutes a day. Mail this coupon or a postal AT ONCE. SHERWIN CODY SCHOOL OF ENGLISH 1812 Searle Building, Rochester, New York Sherwin Cody School of English, 1812 Searle Bldg., Rochester, New York. Please send me at once ad Free Book ‘“‘How to Speak and Write Masterly English The Boy Craftsman Tells how to design and make many useful things. Many suggestions for indoor and outdoor pastimes. Price, postpaid, $2.65. Popular Science Monthly, 225 West 39th Street, New York City Begin Today-Write for My FREE BOOK I can make a good Lpenmen of mt pon dur dur m8, GR 0 time Ee cont :ins © Eaton 7.4 tells h ers mas- tered penmanship by the Tamblyn System. Your vey 3 ~~ pay postage tite for it Today. : F.W. Tamblyn, 437 Ridge Bidg., Kansas City, U.S.A. Descriptive Astronomy By E. M. Moulton. A study of the earth, sun, oem, and stars, with a simple explanation of the ‘principles astronomy. Price, postpaid, $2.65. Popular Science Monthly, 225 West 39th Street, New York City Copy this Sketch and let me see what you cando with it. Many scactoomiete and illustrators earning $30.00 to $200.00 or more per week were trained by my person- al individual lessons by mail. Landon Picture Charts make origi- nal drawing easy to learn. ene sketch with 6c in stamps for sample Picture yp long list of successful studen ang o dence of what you can accomp! ‘THE LANDON SCHOOL 451 National Bidg., Cleveland, O. TAMMER If you stammer attend no hool until you get my large FREE oe ached d STAMMERING Its Origin and The Advanced Natural Method of Cure,” bound in cloth and stamped in pure gold. Ask for spe- cial —, rate and a bag copy of “The Natural it, best equipped and most ul ‘nea in the oad for the cure of stammer- ing. No sing-song or time-beat. School oun all year. Now is the best time to enroll. Lee Wells Millard, Pres. The North-Western School, 2335 Grand Ave., Milwaukee, Wis. can become ° skilled po --4 Dr. Quinn’ . y of piano or pao hn in poem gran **How to Study Musie’’. 7 MW. L. QUINN CONSERVATORY, Studio 7532 S08 Cobb eed Sere, 25 Bow

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co eedioeed Chicago, Illinois ~ MICHIGAN AVE~ ONTARIO ST.~ Thousands of men come or write to me— “How can I make more money? I want a better job— more pay—a bigger future.” I answer them—“Know how to do some one thing well. Be a trained man. Learn by’ actually doing, under com- petent instructors, the work you would like most to do. Become an expert in the best paying business today—the Auto Service Business.” Come to a RAHE School. Learn Auto Mechanics thor- oughly. Qualify for BIG MONEY Jobs. Don’t delay. Write for my 68-page cata- log. Write TODAY. DD intents Occupation . OF AUTO & TRACTOR TRAINING Write for | j~ This 68- Page Book * Aur~ oe i. i 2 Se ol) SY SL a A a A ee es ce OE Send this coupon today for my fine 68-page 4 Catalog showing graduates success and oppor- tunities now open. (Address nearest School.) ERATE a aa POSSE He. Seeerecereeeseeeee, oe Popular Science Monthly af th i * : scnOOL aunt AUTO. D8 Tas “ant City. ane gma onto Ohio. ~22™° & OAK ST~ ~9Ot & WALNUT ST~ have brought the ahe.Way OPPORTUNITY 1S now to Oo hundreds of miles closer OW you have the choice of THREE BIG RAHE SCHOOLS. I have established the famous RAHE- WAY of Automotive Training in Chicago and Cincinnati, as well as Kansas City. To thousands of young men, OPPORTUNITY now is hundreds of miles closer—as near as Chicago or Cincinnati. Hundreds Train at Cincinnati For 14 years I have been teaching Auto and Tractor training at Kansas City. The great success of my school meant I must expand—add more floor space or establish new schools. Why not, I thought, take Automotive Training to the thousands of men who could not come to Kansas City? My idea proved sound. The Cin- cinnati School has been a big success from the day its doors were opened. From the Eastern, Southern and Central States, hundreds of students have poured into Cincinnati. Chicago School is Popular Now the Chicago School is going full-blast. It is a full-fledged, independent institution, teaching the famous RAHE-WAY, equ pped just the same as the other RAHE Schools. Already hundreds of students are in training. Hundreds and thousands are coming. Why? This Is An Automotive Year More money is being spent this year than last for auto and tractor upkeep and repair. THREE BIL- LION DOLLARS this year to keep autos running. You can have a big part of this $3,000,000,000.00 if you train yourself the RAHE-WAY—the Practical Job Method of teaching Automotive Mechanics. You can Make $150 to $400 a Month RAHE Graduates everywhere are making Big Money. This is YOUR oppor- tunity io BREAK AWAY from LOW PAY. Clip out the Coupon and send it i to-day. It will be one of the most fortunate things you’ve ever done SEVEN DAYS’ TRAINING FREE Come seven days to a Rahe School. I guarantee that if you are not co gin satisfied with the training at the end of that period—IT WON’T COST YOU ONE CENT. SAVE $50 Write today for my special limited time tuition offer which will save you $50. This is a lot of money. | ew your room and board while here,—far more than pay your railroad fare to my nheares Don't delay a minute. My guarantee makes it easy for you to come now—for I am taking the . chance not you. If impossible to catch the first train, write today for my 68-page catalogue, which tells how other men have found the road to big money positions, independence, success HENRY J. RAHE, Dept. 2880 Chel; Chicago, Illinois, Kansas City, Mo. Cincinnati, Ohio Michigan Ave. & Ontario St. 22d and Oak Sts. Sth & Wainut Sts. he et oF @ ow me We oe — bh Q i &, 3 / «s; Ks ey WY ~ Ww x

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=k bora a K? “a wh Every bay loves boats and trains OCOMOTIVES and ships fascinate a_ Ives boats are made of steel, beauti- boy. Playing with toy trains fully painted, with long-running spring and boats is the best fun in the world. mechanisms, propellers and rudders. They never seem to lose their appeal. They are complete even in small de- Ives trains are wonderful reproduc-_ tails. Real ships were used for models tions of originals. There are both —ocean liners, diving submarines, steam and electric type locomotives, destroyers, tug boats, motor boats, propelled by springs or electricity, cars U.S. Merchant Marine steamships. of all kinds—passenger, freight, coal, Ives Trains and Ives Boats are oil, lumber, livestock; with switches, sturdy American-made toys that every fr bridges, tunnels, stations signals, sta- boy would like to own. They are per- af = tion lights and crossing gates. fect Christmas gifts. f Send 10c. for Booklet fo N of Trains and Boats. f THE IVES MANUFACTURING CORPORATION, 191 Holland Ave., Bridgeport, Conn.

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The Victrola is the gift of all music to your home Wherever the dawn of Christmas morning finds a Victrola, there are gathered the ¢great- est artists of this generation. All have con- tributed their art to the Victrola, positive that it is the one instrument which brings to you their authoritative interpretations in the tones of actual reality. Will there be a Victrola in your home this — mommggens: 9 Christmas? $25 to $1500.. te ee “*Victrola’’ identify all our products. Look under the tid! Look on the label!’ VICTOR TALKING MACHINE CO., Caméen, N. J. Victor Talking Machine Company, Camden,N.J.

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