Popular Science Monthly 1919-03: Vol 94 Iss 3

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at o WAR 2 y 1918 ir | oe’ Univ. oF See Page 58 20 Cents

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It's Open your &~ i \ package {;_ WA ee : ~~ p , ‘ “ pe ae , this way ij hd nigh ig cE: On the way down town After a baked apple for breakfast! Wasn’t it good? ‘Tastes better than a raw apple—more flavor. Now —as you light it — notice the delicious “cooked” flavor of your LUCKY STRIKE & Cc i a ret t It’s toasted. Likethe apple, it tastes much ]@ better “cooked” than “raw” because - ® “ ——S Its toasted oy eae ~) ¢%

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_ choose a more prom- March, 1919; Vol. 94, No. 3 Twenty Cents; Two Dollars a Year Popular Science Month Waldemar Kaempfferi, Editor Published in New York City at 225 West Thirty-ninth Street what we do not know about volcanoes will, a hundred years hence, fill a good-sized library. Volcanology is in the making. For that very reason it is all the more fasci- nating. A young man who wishes to make a name for himself (and little or no money) could hardly [E us be honest and confess that ising career — than yee Vip jhe oS . se ¥ UE Lf MMMM MB id ll bli hag Yell sm “titre Also afew things we do know— notably about the tides in the solid earth and in lakes of lava By Calvin Frazer that of volecanologist, provided he has ‘an aptitude for scientific research, the physique to endure rough mountaineer- ing, and the courage to face the risk of being engulfed in fiery lava or buried under a shower of red-hot rocks. There are plenty of brilliant discov- PT pa a tt 17 What We Don’t Know About Volcanoes eries to be made, and the field is not a bit crowded. Our grandfathers knew a great deal more about volcanoes than we do, but what they knew was nearly all wrong. They declared, that the interior of the globe was a “molten mass.” It is, almost certainly, a dense solid, more rigid than _ steel. How do we know? s By several facts— MULLIN Long before war made them famous, gas-masks were faithful friends to students of volcanoes. These masked experts, working on the temporary crust of a hot lava lake, are collecting samples of gases Photograph by Dr. A. L. Day

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iddahlabalhddaddc. Wadiddddaddddcabiacsicdasblbdiasbaheg aiiiabasicsdiabbubputssissiiglasslcstedddddsatidcddcdéddcaidcdddatcdd oe Popular Science M. onthly | dd edacdeeccsciccedchchodddeddeaddddddddaddddddaaddaegEHEE, Photograph by de Vis-Norton The weird beauty of the lava as seen at night. when waves of living fire break against the mountain crags its weight (as determined by astrono- mers), the way it transmits eafthquake waves, the resistance it offers to the distorting effect of the sun’s and the moon’s attraction, etc. But the in- terior of the earth, as far as we can determine, is so intensely hot that if at any place far below the surface the stupendous crushing force of the rocks above is, by any means, somewhat re- duced, the solid must change to a liquid or even a gas. Earth Tides Cause Eruptions Various. circumstances do, in fact, bring about an easing up of this pres- sure, here and there and from time to time. The whole globe is shrinking as it cools, and its surface is warped into folds and creases. Moreover, there are regular tides in the earth’s crust—a rise and fall of about a foot, on’ an average, twice a_ day. These ie ais = — dl things cause variations in pressure underneath, and the melting of deep- seated rocks probably takes place on a vast scale. It is only occasionally, however, that a little of the liquid rock, known as magma, rises to the surface and gives us a volcanic eruption. How does the magma get to the surface? That is one of the things we do not know about volcanoes, but we have a strong suspicion that what happens is this: Imagine a large mass of melted rock miles underground. It is subject to tidal and other stresses, pressing it this way and that. Inthe brittle crust of the earth there are many fissures, through which the magma will be squeezed out as far as possible. Suppose one of these fissures, direct- ed upward, to be nearly filled with the magma. Through the magma stream gases, generated from the more. volatile elements of the rocks, and these gases accumulate at the top of the column, where they are under such great pressure that they become exces- Photograph by Professor Jaggar Professor T. A. Jaggar and L. W. de Vis-Norton, of the Ha- waiian Volcano Research Association, taking lava temperatures rock, a. small amount of } Siienaat by Professor Jaggat Just before the overflow of the lava lake of Kilauea emerging from the lake, which is flowing rapidly from right to sively hot, according to a well known law of physics. It ig probably this hot gas which, by melting the adjacent rock, eats its way through the strata, forming a vent for the magma. The liquid rock may come forth in a quiet flow at the earth’s surface, asin the case of the volcanoes of Kilauea and Mauna Loa, in Hawaii, or it may burst forth in a great explosion. The _ explosive effect is probably much in- tensified by the presence of steam. Specimens of volcanic gas col- lected in the crater of Kilauea and pumped from the lava into collecting-tubes, without com- ing in contact with the air, were found to be heavily charged with steam. Lakes of Lava with Tides It is easy to see that if a narrow vertical channel is connected with a large sub- terranean reservoir com- pletely filled with liquid

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Tides tifa el ig sub- come - iquid it of _Jaggar; and one of the LO LUO Mldd ts HAD OAMMMU ALOUD Me Th lth a SAW MMH NNN HNN HA Nyy yy NE TT ed ee ceeded decodes ud dcsdcdcccecdededsdddddsseuut ies dadiecibcscccccddaccdeeddschaccdddeccsscdasldddssssiassiiil isda di dassblasssbsdsatalila volcano. The crags are the head of the main lava column left in the picture, while a small fountain is playing at the right pressure ‘on the latter will cause a rapid rise of the liquid in the channel. Apparently we have a case of this kind in the Hawaiian volcano of Kilauea, with its remarkable lava pit of Halemaumau. This pit is a small crater within the big one, and it con- tains a lake of lava, which pronounced tides, depending upon the relative positions of the earth, the sun, and the moon. The lava is high- est in summer and winter and lowest in spring and autumn; and there are minor oscillations twice a day and twice a-month. Dr. Jaggar believes rises and falls from day to day. Sometimes its surface is hundreds of feet below the summit of the pit, while at other times it rises quite to the top and overflows. For some years past daily measurements of the level of this lava have been made with surveying in- struments by the staff of the Hawaiian Volcano Ob- servatory, under Dr. T. A. most interesting of volca- nological discoveries is that the lava lake exhibits very Photograph by Professor Jaggar Surveying the lava lake, 200 feet below the observer. The usual method of reaching it is by rope ladders 19 SHLAA WAH MAINA TA I DANN SAE AAW NH NH De VEEL MALU D LNAI PIAA Photograph by Professor Jaggar Looking out over the lava lake. The foreground is composed of lava less than an hour old, already breaking up that the intermittent lava flows, on a much larger scale, from the neighbor- ing crater of Mauna Loa, are also due to tidal forces, and he justified this belief by predicting, some years in advance, the eruption of that volcano in 1916. Can Eruptions Be Predicted? Can the eruptions of other volcanoes be predicted? If so, then voleanology is one of the most important of the sciences in terms of human welfare. This practical problem is not yet fully solved, but it is in process of solution. A sudden succession of earthquakes at a voleano portends an eruption, and the few volcano observatories ‘of the world are all equipped with seismo- graphs — instruments that record the slightest earth tremor. When an erup- tion is in progress the chemical com- position of the volcanic ash gives some indication as to how long the eruption will last. e That our lamentable ignorance on the subject of volcanoes is gradually giving place to valuable knowledge is due to a small number of investigators, seme of the most brilliant of whom are Americans. The foremost volcanolo- gists of the world today are the Ameri- cans Jaggar and Perret, and their field work has been . admira- bly supplemented by the re- searches of the Carnegie Geophysical Laboratory, in Washington, under Dr. A. L. Day. Shortly before the European war began, an international institution of voleanology was established at. Naples by Im- manuel Friedlaender. It is now temporarily located at Schaffhausen, Switzerland. The leading volcanological observatories are the one on Kilauea, maintained by the Ha- waiian Volcano Research Asso- ciation, and one on Vesuvius. recent gine nema ; —— pin i em magne oy ee ee eee ie aie

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ee Pine inne a = A Gigantic Rock of Ages ERHAPS the hand of man has never carved out another single stone as large as this. It is 68 feet long and 14 feet square, and weighs 1,200 tons. Huge monoliths from the same quarry where the giant reposes are found in the stupendous ruins at Baalbek, Turkey, where 4,000 years or more ago a wonderful race of builders erected the temple which men today call the “Trilithon,”’ after the great stone in the wall. The stones that were transported from the quarry are only a little smaller than their titanic brother, being 63 feet long-and 13 feet square. Labor was cheap and plenty in those early days; but, even so, engineers of today marvel at the ingenuity and resource of the builders, who by hand-power and inclined planes drew the monsters from the ‘quarry bed, transported them to the site of the temple, and swung them into their appointed places. His Barometer on His Knee HEN an aviator wants to know whether ‘he is getting up in the world, he consults an instrument of the barometerspecies. Barometers, as you know, measure the weight of pressure of the atmosphere. An ‘air. pilot hasn’t- much space in . which.to store the tools of his craft, and . so. Lieutenant Giuliano Parvis wears his barometer—a big brother of the wrist-watch—where it will be con- stantly under his eye when he is seated in his airplane. © International Film Service © International Film Service _ French Idea of a Hun Hat-Rack HERE are more important things = to be done in France today than The Ferry Is the Ferryman’s Back F. you wished to cross the Sutley river in India, you would have: the choice of swimming across or of riding on an Indian ferry, If -you chose the latter, you would be offered ferry space either sitting on or lying across the back of a native, who in turn would be lying across an inflated bullock-skin with his legs trailing be- hind in the water. The ferryman inflates the bullock-skin by blowing it up through a hole in one of the legs. After you had climbed on the Indian’s back he would push out from the shore and paddle his way across, kicking strongly. If you shifted your position while en route you. would most likely topple off. In fact you might topple off without shifting. Without a doubt, this original ferry is as clumsy, far-fetched, and dangerous as possible. The only sensible reason for its exist- ence is that the natives had entirely too many bullock-skins. Not as Black as He’s Painted “[ ae fellow deserves infinite praise for standing stoically while an artist tickles his ribs with a paint-brush. Moreover, he is being painted with . shoe-blacking, which may or may' not wash off. But an Ethiopian was badly needed in the movie studio, and the only way to get one quickly was to manufacture him. For the sake of the silent drama— and a good day’s pay—this six-footer volunteered. Half finished, he gives © promise of making an excellent ‘‘black.” Perhaps, after all, movie stars earn their fabulous salaries. i? 4 b> .4 ei ia ia Fath wes cs A 99> piaasd? e * ppgade 100,7? Ww! fF aciee , i ad 94 9997" 2 ae + es $j 427098 , disrobing statues of their war-time sand-bag protection. Since the statues must. remain ugly for a while, the French trimmed some of them up with an over-supply of _German helmets which they had on ‘hand. 20

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; 7 “Marsh, 1919 e <n A German Family-Portrait 4 ' Propeller Watch. N enterprising aviator has AX combined the German pas- sion for family portraits with an airplane propeller in the clock shown below. The propeller is the frame in which the works re- side, and the hours are marked by relatives. This clock is not only ornamentally excellent, but is also very useful to the busy housewife pickling pickles in the kitchen. Too busy to stop her work in order to find out the time, she calls-to her young son in the liv- ing-room: “Wie viel Uhr ist es?” (What time is. it?), and he promptly replies: “Onkel Fritz " - nach Bruder Hans” (Uncle ve" Fritz after Brother Hans).

y. Mother interprets this as er twenty-five minutes past eight, ld and continues her pickling. a= by ad re uf et Almost Human Intelligence 2d, NINE ear-loads of coal, or about st- handled in one day by this elevator, which also screens and cleans the ed fuel at the same time. _ is dumped into a hopper, carried to rs the top of the structure by an end- ith less chain, and distributed according : to size into three bins. not ol ° from the elevator, which is built 6 of steel and is considered a model of its kind. ._— ter ‘ ves” Peace or War—Ham or Turnips ? 1, 9 Se AM and turnips together make a palatable dish, but if choice of one alone were given’ us we would elect ham. No choice was given the German people; and so, after they had turniped for three long war years, they ventured to become displeased with the powers that made things so. The bravest of them, residents of Niederlahnstein, voiced a silent protest in the bill below. In the center stands the town hall, on its left a ham, and on its - tight three turnips. All the little circles around the central group bear the name of the town and the date 1917, except those two directly above the meat and vegetables... The one above the ham, translated, reads: ‘Tender longings, sweet hopes’; and that above the turnips: ‘‘How we live, 1917.”

three thousand tons, can be In operating this elevator, the coal Five trucks can load at one time

Ten Empty Cartridges Make One Swagger-Stick VERY soon, now, people will appear : on the streets dressed up in war Implements which the boys have brought back. Anticipating: this, a thrifty artificer from Michigan gathered unto him many empty cartridges. He soldered together nine or ten of these ‘‘empties,”’. polished them up, smoothed over the rough places, and called the result a swagger-stick. a Dainty ladies who like to swing such sticks will find that these dead ones are still quite powerful if swung with sufficient force. This making new things out of old things would seem to indicate that the thrift born of the Great War will continue to live for many years.

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ons compen on ares: ‘ Neary ee And Trees All in a Row EE the pretty trees growing alongside of the building in the picture below?” Well, look again, and you will see that they are not trees at all. This striking bit of scenery is on the side of a large munitions ; plant in a Cincinnati suburb, and is attracting the attention of F thousands of people. Early last spring the owners of the munitions plant, wishing to hide the brick walls of the building, planted Boston ivy at intervals a3 along the base of the walls. The ivy grew rapidly and soon crowded H the spaces between the windows. When the plants reached the top of the windows they found room to spread in both directions, and ; they soon shaped themselves into trees growing on the brick walls. i

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(aS a z St ha ae abe ene See as pineres some How promptly will the blindfolded sol- dier d to a touch? it depends upon his brain speed respond to impressions by mus- cular reaction? If you don’t know, and the chances are you don’t, | ge promptly does. your brain ‘go to Dr. Amar, in Paris, and let him find out for you. He will submit you to a few psychographic tests, and at their conclusion will tell you your speed to the hundredth part of a second. Incidentally, he will tell you whether you are fitted for the profession or occupation in which you are engaged or intend to become engaged. His Own Invention The apparatus that Dr. Amar uses is a psychograph of his own invention, a device for register- . ing the promptness, intensity, duration, etc., of muscular re- sponses to impressions received by eye, ear, or sense of touch of the person tested.. The appara- tus has a cylinder covered with paper coated with lampblack. This cylinder is revolved by clockwork at the rate of one revolution a second. A vibrating needle, which makes one hundred double vibrations a second, marks a. wavy line that serves as time measure for.minute fractions of a second upon the blackened paper. The muscular reactions of the sub- ject. tested are. transmitted by air-pressure to two needles, which mark a record of ‘these reactions on the cylinder. Dr. Amar will seat you in front of a table equipped with the testing apparatus. Direct- ly before you are two little What’s Your Speed? pneumatic drums. When you have re- ceived your instruc- tions, you place a finger upon the mem- brane of one of the little drums, your eyes focused on some- thing that resembles a small camera. A few minutes la- ter a ‘touch of- the Doctér’s finger upon the -shutter releases allows a flash of the electric light in the box behind the lens to reach your eye. At the same moment—so it seems to you—you press your finger upon the drum-head. The air-pressure in the drum simultaneously causes a needle to markaline, more or less curv- ed, on the lampblack-covered paper. You Read Your Record Then the paper is taken off the cylinder. Here is the’mark of the Doc- tor’s signal and there is the record of Above, a record of the simple reaction to a visual sig- nal and of reactions requiring deliberation by a normal person; and, below, a record of similar tests on a young coppersmith whose brain has been injured 22 Not that of your car, but of your brain? | By Ernest Welleck your reaction. The Doctor counts the number of waves of the vibrating needle on the paper, and informs you that 20/100 of a second elapsed be- tween the signal and your response, And you imagined your pressure to have been simultaneous with the signal! You are assured that your brain functions normally—that the time for simple visual reactions in normal subjects averages between 0.195 and _0.21 seconds. Tests that Involve Deliberation In the tests for reactions involving deliberation, the same device is used. You place one finger of the left hand on one of the little drums, one finger of the right hand on the other drum. You are informed that the left drum means blue, the right drum red. The Doctor flashes a red or a blue light through the lens of the camera-like device, and you signal back the im- pression by pressing the right or the left drum-head. On examining the record on the cylinder, you find that it took you more than twice as long to react in this visual test as in the simple visual test in which you weré not called upon to decide whetherthe light wasred or blue. From hundreds of observa- tions like these Professor Amar has drawn interesting and valua- ble conclusions which enabled him to determine the aptitude of the individual tested for - certain vocations, a problem of importance in finding em- ployment for the thousands of soldiers returning from the war. The statistical material so far collected shows that the age _limits of eighteen and forty-five _years, does not materially affect Subjects whose occupation de- mands alertness—for instance, designers, typists, and mechan- ics—react more .promptly than farmers,’ who are invariably slower by 0.02 ‘seconds or more.- The records of persons who have sustained injuries: of the brain, or who have been _- operated on. because of such _injuriés, “show much higher figures: 0.32 seconds for visual signals, 0.24 for sound signals, and 0.21 seconds for touch sig- ‘nals represent the average for that class of invalids. Popular Science Monthly Pres of the subject, between -the the time of simple reactions. . - eo

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poet i March, 1919: N building docks, trestles, piers, and similar structures, it is often neces- sary to cut piles, stringers, and other timber after they have been put in place. Frequently the sawing has to be done in places difficult to reach, and under conditions that make the handling of the saw extremely awkward. It required at least two men to do the work with the old-fashioned cross-cut saw, and it was slow work at the best. The recent invention of a cross-cut saw which can be operated by one man is of con- siderable importance and value, especially at the present time, when laborers are scarce. This device consists of a light steel frame which is clamped in posi- tion against the tree, pile, or post to be sawed. The saw- blade, which is pressed in con- tact with the wood by a spring, is attached to a slidable rod “C\HE’S running fine,’’ remarks the farmer to his foreman, pointing with satisfaction to his automobile, in ‘which he has just returned from a trip. “That’s good,’’ answers the foreman, “because there’s a lot to do today.” “What’s the program for today?” , inquires the’ farmer. | . “Well, first we have to saw ae _. about fifty fence-posts for that new. pasture; then there , are about a hundred bushels of . ~_ gorn to shell‘and some feed to 5 grind, and if there is time we ought to pump a little more aa water in the tank. And we mustn’t forget to make the butter that is to go to market in the morning.” The circular saw is stationed near the wood-shed, and the j l 4 ¥ 3 f i 1 r 1 —EE— : Turning the heavy churn is mere play r 3 for your automobile, if its power is transmitted by this pulley frame ——————— ow an ae — AS See how neatly this saw cuts the piles flush with the cross-timbers of the pier 7 With This — One Man Does the Work of Two which ‘is moved back and forth by an _upright lever worked by hand. The mechanism is extremely simple and cannot easily get out of order. The method of operating this saw makes it possible to use it in places and under conditions that would preclude the use of the old-style saw. Trees may be sawed close to the ground, which means an appreciable saving of lumber. Piles may be cut flush with the cross-timbers of a dock or pier, and in the case of neces- sity it is even possible to saw piles under water with — this saw. The saw can be adjusted™as to pressure and length of stroke, and one man can do twice the work that two men: can ac- complish in the same time with one of the old-fashioned cross- cut saws. - Making the Farmer’s Car Earn Its Cost and Keep lumber is piled up by its side. The theautomobile. Then he pushes down farmer backs his automobile up a short the cross-bar of the tilted frame. This distance from the saw. The foreman lifts the rear wheels off the ground, and pushes an iron framework with a _ when the cross-bar reaches the ground cross-shaft of steel, having a fixed pul- the rear axle of the car slides down the ley at each end and a movable pulley _ inclined brace of the frame, until the in the middle, under the rear axle of tires of the rear wheels come to rest With the help of this transmitting device (upper picture) and a buzz-saw, your automobile will cut twenty cords of wood on three gallons of gasoline 23 against the two eight-inch drive pulleys at the ends of . the shaft. The drive belt of. the circular saw is slung around the pulley in the mid- dle of the shaft, the proper ad- justment is made, and a few minutes later the buzz-saw, driven by the car wheels, is cutting through the logs. And so the corn was shelled, the water pumped, and the butter churned, all with the help of the automobile. In an idle hour your automobile will grind out a big pile of feed without requiring special attention

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Popular Science Monthy ios How We Transported Whole Railroads rca One of the huge tenders being hoisted on shipboard. Fifty of them and a like number of engines make a full cargo f } Be NY \ 1EL a bee -_ = ee eit: May: an ms ik omg , ° 2 ‘a i ~ * aoe a, Se re Huge A-frame derricks handled the heavy engines As they looked stowed in the hold. Great quanti- and tenders as easily as if they were mere toys engines would nest softly. Not a wisp was wasted, !

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ht 1919 Across the Seas to Distant France .Looking down into the hold of a ship loading with engines and tenders bound for France. Below you see how the job looks when finished Pee es ae ORE EOE BE, PR ties of hay were used in the packing, so that the Lower away! It was necessary to turn the engines as our cavalry and artillery horses can testify diagonally across the hatch-opening to get through

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The biggér and higher the pile of coal nd high ’ COAL PILE WIRE TO the greater will be the danger of sponta- Beer ona oe +— Plea } MAIN CABLE neous ignition in the interior of the mass a3 | POINTED IRON EN coal is stored in large quantities there is always dan- ously. The larger the quantity of coal stored, the greater the possibility of its catching fire. ger of its becoming ignited spdntane- i i F. The higher the pile, the greater the pressure by the over- lying mass on the coal near the bottom of the pile, and the more thorough the exclusion of air from its interior. The organic matter of which all coal consists is constantly undergoing a process of slow oxidation. - EF a gas-range does not burn the way it should, its owner should give it attention at once. Popping of burners when lighted should be a wastes gas. signal to see that the burners are cleaned. Even if the burners are clean, however, there may be a waste of gas. The most fre- quent cause is toe much or too little air. ‘Either defect is very easily remedied with a screw-driver. The air intake is directly behind the handle, or valve, used to turn the gas off and on. This air in- take has a sliding shut- ter fastened in place by a small screw. Loosen this screw and turn the shutter until the intake is complete- ly closed. Then turn on the gas and light the burner. You will find that it burns with a yellow flame, con- suming a great deal of gas and producing On the How. to (At right) When the shutter has been adjusted to make the gas just right for the blue flame, the screw is tighten- ed to keep the shut- ter in that position i H /ROWS OF IRON PIPES ~ j TO BOTTOM OF COAL PILEY WIRES FROM ONE ROW oF | surface, in the absence of pressure, and with unrestricted circulation of air, the heat set free by this chemical reac- A neglected burner P cae a of 05 06 07 | PIPE REACHING i > Bo Do: ects oo ay Seay of coal. Ce oo “E10. so ‘| De r:) “ji o- r a i Eo 8 2 aio eo. 0 } tion begins. at intervals. ———~_ ELECTRICAL THERMOMETERS —$rcnnE TO ENGINEERS OFFICE Make the Gas Bill Shrink Learn to regulate the flow of gas in your range and save money little heat. (Above) With the flame high, most of ‘the gas is wasted in evaporating the water.The other pic- ture shows the flame as it should be with the water simmering Popular Science Month Don't Let the Coal Set Itself on Fire Under pressure it Loney ignite spontaneously Electrical thermometers placed in vertical tubes driven into the coal- -pile at regular intervals will give warning of danger tion does not rise to the ignition point But under pressure the tem- perature steadily rises until it reaches the ignition point of coal and combus- In some of the big yards, wrought- iron pipes are driven into the coal-pile Electrical thermometers are placed in these pipes from time to time, and when the temperature re- ported from any point in the pile reaches the danger point, the coal at that point is thoroughly aired. Open the shutter slowly, watching the flame. When it is all blue, the maximum amount of heat per gas unit consumed is being produced. When the shutter is open to this place, tighten the screw so as to fasten the shutter firmly in place. The commonest cause of wasted gas is the rapid boiling of foods. In boiling potatoes, for instance, the gas is usually turned on full force; yet the potatoes are cooked only a little ._ more rapidly than if | the gas were turned low so that the water barely simmered. In either case, the wateris at the boiling temper- ature, and no higher. By turning the gas low. after’ the boiling stage is reached, the potatoes can be cooked almost. as quickly as with the gas high, little water evaporated, and almost half the gas saved. f Stat The iron pist engi stea well esti in t not aut yea in n sar mez this be | whe . Ting for nov nev in 18, of iro: she

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ie. as 2, as: er st ng ng ce, lly ce; ire tle ed : ter ris er= er. yas ing the ced ttle and gas a perc, 1919 Making Piston-Rings by Whirling Them into Shape And the speed is forty times greater By E. F. Cone One man pours the metal into the trough and another operates levers that control the casting tured products of which mil- Orr of the many small manufac- lions are used in the United States alone each year are piston-rings. They are thin round objects of cast- iron, made to fit in the cylindrical piston of all automobile and airplane engines. There are many used in steam, marine, and other engines, as well as in pumps. A conservative estimate has placed the number used in this country alone in one year at not less than 200,000,000. The Ford automobile plant uses about 16,000,000 yearly. It has been customary, and still is in most plants, to make these rings the game as any other small iron casting is made—molding them in sand by means of a molding-machine. By this process about 420 rings a day can be made by each machine. But a new process has been invented whereby the old way of making these . tings is virtually revolutionized. It %. ‘hard, and afterward ground on a - special machine, thus rendering the finished product nearly ready for use, only a little machining being necessary. - An important consideration is that the rings are uniform in size and thickness is called the de Lavaud process, named for the inventor, a Brazilian who is now a resident of New York. By this new process, rings are being made daily in one machine to the number of | > 18,000 or 20,000. The unusual feature of the process is that the hot molten iron is cast directly into its final ring shape by centrifugal motion. A Very Simple: Process The process is very simple. It consists in introducing into a rap- idly revolving iron mold a definite amount of hot metal of proper composition. This is immediately thrown to the outer surface of © the revolving mold, where it quickly cools and assumes its definite shape in the grooves of the mold. It must then be an- nealed, or softened, for it is very of section. The machine in which the rings are cast consists of three arms protruding from a central revolving standard. On each arm is placed a permanent mold in which the rings are cast. This is a series of alternating rings of cast- iron and of thin boiler-plate separating the rings, these forming a series of grooves, the size and thickness of the piston-ring to be made. By varying these, any diameter ring from 11% to 8 inches can be made in this machine. By enlarging the machine, rings from 30 to 40 inches in diameter can be made. These alternating pieces of metal are held together by an ingeniously Pre Trt i Ki te aOR DIO I 8 I EE FO PR IF He puts the rings into, the an- nealing apparatus and they come out at the bottom softened 27 arranged set of bolts and: pins. A re- volving wheel, operating by electricity at the bottom of one side of the central standard, is the motive power that causes the axle carrying the mold to assume its rapid motion. This has a momentum of 1,200 revolutions a minute when the ring is being cast. How the Rings Are Formed A movement of the larger hand lever, shown in the picture above, quickly brings the revolving mold over the small trough in which the hot metal is poured. These troughs are replacea- ble at any moment, and are lined with a refractory. A rapid inversion of this trough while inside the revolving mold empties the metal into the grooves, thus forming the rings. A further slight movement of the lever brings the revolving mold against a brake, which stops the. revolution. A re- versal of the lever brings the mold back against the central standard. -A turn of the machine carries. the mold with its rings to the right, and brings a new mold ready for a new charge of metal. : The‘ molds are transferred to the four arms of the pedestal situated at’ one side of the casting-machine. Here a crew of boys remove the bolts, allowing the rings to fall into baskets. “The disassembled molds - are-kept intact loosely, and placed on the arms of a revolving wheel, by ‘ means of which they pass through a tank of cooling liquid. A new machine has nearly been completed for perform- ing the disassembling by electricity. This new process is unique. The product is not only practically ready for use, but is superior in every way. The metal has been proved to possess striking properties. in the way of strength, elasticity, and uniformity, particularly as to its hardness.

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r es is the story of a restless English -schoolboy who lis- tened wearily as his teacher talked Boyle’s- Law and Archimedes’ Principle. What was Boyle or the laws that gases and liquids under pressure obey to him? The time came, ten years later, when they meant life or death to him. It happened during the war, when he was. one of the crew of a British . submarine. .- . His boat was lying idly on the surface of the-water. . All the officers and crew except himself were enjoying a holiday ashore. He went below to work in the engine-room, and left the conning- tower hatch open. Then something happened—the young man never. knew just what—and the boat lurched down by the bow. By Joseph Brinker sure, hestopped. Water, gas, pressure —what about them? He Remembered That Lesson Then he remembered, that, in the case of a body submerged in water, the combined force of the gas within and the strength of the body material must equal the force of the .water without, or the water would crush the body in. Just so the combined force of the air in the submarine and the steel of the hatch equaled the force of the water pressing down on it. If he could make the force of the air in librium and consequently .— easily moved. His next problem was how to decrease the volume of the air. There was only one way. to do this——by letting the water in. If he did that he would be taking a last desperate chance; for. he did not know how much compressing the air needed before it would exert q © force equal to that of the water outside. If this failed him, he would drown without a doubt. Taking a Desperate Chance He decided to take the chance. So, groping in the dark, he opened the bilge- valve and let the water in. As it crept up about his waist he philo- sophically decided that. he would much rather drown than suffo- He thought of the conning- tower hatch, and rushed forward to close it. But the water was already pouring in with such force that he was unable to accomplish his purpose. He re- turned aft to the engine-room, and locked himself in by means of a water-tight door which separated the boat into two compartments. In Complete Darkness . He was safe temporarily, but the other half of the boat was filling with water, and the sub- marine was sinking lower and lower. . The engine-room was in com- plete darkness, due to the short- circuiting of the electric system. Everything he touched shocked him. The salt water on the storage batteries generated suffocating chlorine gas. He rushed blindly - .. at the engine-room hatch and tried to force it opem. But his strength was no mateh*for the * The air shot upward with great force, draw- izig the sailor through the sunken submarine’s hatch and carrying him to the surface cate, anyway. But when it reached his waist he grew some- what nervous and thought he’d better ‘try the hatch. He pushed against it, and it opened slightly; but it slammed shut again, crushing his fingers, for the pressure of the air was not yet great enough to resist the water without the aid of the hatch. Nursing his injured - fingers, he waited stoically until the . water in the engine-room reached . the hatch coaming. Then, with just his head above water, his ear-drums strained from the compressed air, he made a final attempt to raise the unwilling hatch. His patience, bravery, and cool- headedness were rewarded. At last the air was compressed enough to equal the force of the water, and the hatch moved easily. Physics Sees Him Through After helping him thus far, pressure of the water outside; - and, even if he had been able to open it, he would have been no better off, for the water would have rushed in and drowned him before he * ould possibly get out. He Reviews His Past Realizing that his last chance was gone, he grew quite calm, and, as is the custom of dying folk, reviewed the things he had done and those he ought .not to have done while here on earth. As he came.to that day in school when he unwillingly learned of pres- the boat equal to the pressure of the water on the boat, then the hatch would be relieved of the strain of holding off the water, and. would be easily lifted. How could he increase the force of the air? Then he thought of Boyle’s Law, which he had been forced to memorize on that long-ago school-day —the volume of a gas varies inversely with its pressure. If he decreased the volume of the gas in the submarine, he might increase the pressure enough to make it equal that.of the water. This done, the hatch would be in equi- 28 physics decided to see him through: The compressed air in. the submarine repelled the water which was trying hard to pour in and drown him. The air shot up- ward with great force, taking the sailor along with it to the surface of the water leaving him _ there, breathless. After he had righted himself and shaken the water from his eyes, he looked about and saw, a little dis- tance away, a friendly destroyer, which soon picked him up. Such an experience must surely force on any man a great respect for school, teachers — and fate. Popular Science’ Monthly. ee Trapped ina Sunken Submarine Tons of water pressed down on the hatch. How could he escape? Recollection of an old physics lesson saved him from death

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He Prayed that Air-Pressure Would Help Him to Open the Hatch Trapped alone in the engine-room of a submarine when it sank, an English sailor was saved by his quick wit and the remembrance of a long-forgotten physics lesson. It came to him that by letting the water into the sub- marine the air would be compressed until the pressure inside would equal that of the water outside and he could raise the hatch. He gambled on the chance that the air-pressure would enable him to lift the hatch before the rising water drowned him. It was' a close shave, but he won,'and as he raised ‘the hatch-cover the rush of air behind him carried him through and to the surface—alive. ~~

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Popular Science Monthly. Here is a four-ton truck haul- ing a fifteen-ton locomotive Why This Steam Locomotive is Riding on a Motor-Truck HE illustration above is a relic of the famous Priority Order No. 2 of the War Industries Board, which prohibited the use of freight-cars for hauling road-building materials such as stone, and cement, and machinery. When the Road Commissioners of Wayne County, Michigan, found that they could not get materials to several How to Make a Radiator Cool Itself N a temperature controlling device for automobile radi- ators, by Harris S. Coy, of Indiana, the front of the radi- ator housing is provided with a series of shutters hav- |g ~ “ing at one end forked radial © arms and springs engaging in a vertically movable bar. A casing in the upper tank contains a fluid that is quick- ly expanded by heat. When this happens, the pressure acts upon a piston which causes the rod to open the shutters and admit air to the radiator. When the water becomes codied, the contrac- tion of the fiuid draws the piston upward, closing the shutters. 4 Storage battery When the radiator gets too hot, the shutters in front of the housing open automatically and cool it off important roads that were under con- struction, they turned to the motor- truck for assistance. With the help of aspecial trailer, a four-ton truck car- ried the fifteen-ton steam locomotive from job to job, even beating the time by which it had previously been shipped by rail. The engine was delivered direct to the job with but two handlings, load- ing and unloading. By rail it required four. First it had to be loaded on a wagon, hauled to the railroad station, and then unloaded. At the end of the run it had to be unloaded on to another wagon from the car and handled the fourth time from the wagon to the ground at the site of the job. Tractor motors are tested at different angles to prepare them for a strenuous future existence Testing Motors for Tractors WING to the varying positions in which a motor for tractor use is operated, the motors shown here are tested on a tilting stand, and must start, contrel, and operate just as satisfactorily on a longitudinal inclina- tion of 45° as they do on a level plane. During the test on such a stand, this motor showed a fuel: economy of .54 pounds per horsepower hour. It is a four-cylinder engine, bore 61% inches by stroke 734 inches, and is practically an eight-cylinder patrol model motor cut in half, with the oiling system and various other de- tails adapted to tractor work. develops from 120 horsepower at 900 revolu- tions a minute to 160 horsepower at 1200 revolutions a minute. 1,580 pounds. 30 The motor The total weight is To Moisten Air for the Engine OR some reason, moist air gives slightly greater power to automobile engines. A device for moistening the air consists of a small tank mounted under the hood. The water is kept at a level just below the top forming a vapor space through which the moist air passes into the engine. The air enters through two holes in the top, and follows the course shown in the dia- gram below. : TOP LOCK HANDLE SPRING DISTRIBUTOR, aa PLATE Zig TO INTAKE MANIFOLD Does your automobile run better in damp weather? Feed the en- gine moist air with this device evs... Bari Del by} see | over] a los one 1 Pow cept teria emp) shop pulle the 1 cient so t

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er 8. he vk he ist or ist VO ws TOP ACUUM PACE, \ RIN vice Delivering automobiles three-in-one by putting them on top ofoneanother An Arrangement for Carrying Two Trucks on One URING the recent railroad em- bargoes, it was quite common to gee a fleet of motor-trucks delivered a load a smaller truck chassis. But one truck carrying two smaller chassis The Motor-Truck in a Machine-Shop HEN the flood waters of the Grand River short- circuited the electric power-plant of the Michigan Power Company in Lansing, Michigan, it shut down all ex- cept one of the factories in that city working on war ma- terial. One of the companies got around the difficulty by employing a truck chassis to furnish power to run its tool- shop. The chassis was simply run into one of the aisles, and a pulley was placed on the rear end of the gear-set to drive the main ceiling power-shafting by an ordinary belt. The 40-horsepower engine of the truck supplied suffi- cient. power to run the shop until the waters subsided, so that no time was lost. was quite another thing. In thecase and similarly a timber extension was illustrated, the big truck was a 3144- used on the 114-tonner to support tonner, the next a 114-tonner, and overland, with each truck carrying as that on top weighed one ton. A special framework was mounted on the body of the carrying truck, the 1-tonner. The method has been used to distribute trucks from a Chi- cago factory to near-by points and from Pittsburgh as far as Washington, D. C. An Frain Office on Wheels N the shortage of_skilled labor an automobile manu- facturer of Detroit recently adopted the novel scheme of sending the employment office to the men instead of making the men come to the office. \ A special office was fitted up in one of the company’s motor-trucks, and the vehicle was sent out on a trip whenever applications at the plant office were unusually small in number. : The man in charge of the truck rounds up the men, dis- covers their qualifications for the work to be done, hires them if they pass the simple examinations given,and motors them to the factory. The traveling office has a desk, files, and application cards in the front part of the truck. A motor-truck that took the place of a short- circuited power-plant and ran a machine-shop One end of the motor-truck that was, turned into an employment office and went out looking for help

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“The freight-car containing boxed canned milk was broken open in the train wreck like so much cardboard. But the boxes of milk were uninjured. That shows what good packing means Bn ES See dem nee Some genius thought that boxes of dried fruit would not be scattered in a sway- ing car if they were braced with a few planks and props. Here is the result Now cast your eye on these braces and supporting blocks. Crossing the continent, not a box will move from its proper . place Insecure bracing did it. As the car swayed the boxes at the bot- tom of the tiers collapsed. Some- body must stand the loss. It’s you, as the innccent, ultimate consumer The barrels are loaded as closely as possible; and the slack in the center of the car and along the doors is taken up with bracings to prevent shifting “Damaged in Transit” Ma: Popular Science M onthly What. kind of a brain was it that conceived the idea of wrapping a mir- ror in cardboard? The inevitable, of course, happened The shipper can help Mr. Hoover -’ by preaching the gospel of proper | packing, loading, and clear marking. - One railroad alone last year paid $600,000 to settle damage claims. Here are some of the items of that « tremendous, needless bill. be Improper loading, frail packages, and rough handling, $284,599; loss of package, $86,255; loss from pack- age, $70,302; wet, $31,527; defective equipment, $5,950. It’s a wise packer who pulls the protruding nail—the cause of thousands of dollars’ loss annually. When a sack is ripped open by a nail, not only are its contents spilled, but the whole pile sags epibtks ees: FOLGERS, fields a beat Wire-bound boxes should be loaded as here indicated, with the cardboard containers ontop. Obvious? You wouldn’t think so if you could see how some cars are loaded

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March, 1919 Machines that Take a Log and Turn Out Billions of Matches Photographs © Press Illustrating Service Ever stop to think how much time and labor go into the making of that match you throw so carelessly into the gutter after lighting your cigar? There are at least thirteen distinct processes involved and much ingenious ‘ma- chinery. Below, the splints, or sticks, are coming from the drying-machine Matches begin life as a three- foot log. First the bark is chopped off; then the log : goes through a_ veneering- machine which cuts it into strips, and these disappear into the chopping-machine, to come out as match-sticks In closely packed ranks the matech-sticks march to the dipping-machine, an arrange- ment of endless-chain. car- riers .which pass the tips through the fire-making solu- tion. The machine shown below handles 1,000,000 matches at one operation As the match-sticks: fall out of the chopping-machine, into the chute, they are sucked up through the large pipe to drying-machines on the floor above i Rea) Oe aAP Shain mba a5 va. eh Silla! Basic. ew Chaperoned by these two girls, the machine sorts and arranges the match-sticks. The separate cards of splints are then stacked in shallow boxes, ready to go to the dipping-machine, which provides their business ends Ready to go out to light the: world. At the left is shown the packing-room in a modern factory, where the finished matches are placed in their paper boxes

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Popular Science M ontily OU sit around a table with ten other believers in y spiritualism, the hands of all eleven of you spread out flat and your little fingers touching. Next to you is the medium—a big, likable fellow with a kind, frank face. “Tf the spirit moves,” says he, fixing his eyes on you, “‘I shall produce some startling phenomena with the very hand that your little finger now touches.” It sounds incredible. ‘Not if I know it,” you say to yourself, pressing your little finger harder against his. You are determined that he shall not remove that hand —not for the fraction of a second. Then the lights are lowered. Under cover of the darkness, the medium is seized with a series of convulsive twitches and spasms. His hands shake, and ‘the table trembles. However, you are not to be caught napping. You exert still more pressure on your little finger, and_his hand is still there—or was. For lo! a dinner-bell is suddenly rung in your ears, a whistle is blown, a gong is. struck, and a flashlight shines in your face. You are not only amazed and bewildered—you are . really seared. And when the lights are turned on, there, just as you anticipated, is his hand with your little finger resting on it. You > could swear away your repu- tation that he had not moved it. How, then, did it all happen? A Very Simple Trick Do you recall the instant when he was seized with con- vulsive twitches? At that time he was drawing his hands nearer and nearer together until, in one violgnt spasm, he had withdrawn one hand altogether—the very hand under your little finger! Oh, yes, you regained control of it again instant- ly, and you forgot all about. the loss of it a mo- ment later. _The medium’s hands are in the center, his little fingers being held down by the little fingers of the persons on either side By substituting one hand for two under cover of darkness and excitement, he gets a hand free to carry on his “‘manifestations” Taking the Spirits How mediums produce some By Hereward Carrington, Ph. D., The fact is that the medium substituted the outstretched first finger of his other hand for the little finger of the hand you held—so that then you and the man on the other The medium’s hands placed on his knees appear to be securely held, but he gets one hand free without your knowledge. (Above) You think you have his right hand firmly in your grasp, but in reality itis his /Jeft wrist you are holding side of him were both controlling the same hand, leaving the remaining hand free to perform the manifestations. Can you imagine anything which would be more simple than this? A More Elaborate One But there are more elabo- rate demonstrations of the same character. The whole hand of the medium may be apparently controlled; yet he manages to release it all the same! He sits in a chair and places his two hands on his knees, while an investigator sits on either side of him. The man on his right side grasps his right wrist, while the me- dium himself grasps the wrist of the man on his left side. Thus a circle is formed in which the medium is holding the wrist of one man, and is, in turn, hav- ing his other wrist held by the other man. Obviously, ° the wrist in the grasp of the other man cannot pos- sibly be used to produce the manifestations. But _ they do take place, never- theless. After the lights are turned cut, the medium requests the man on his right to remove his hand for a mo- ment. “I want to use my hand- kerchief,”’ he says. In a mo- ment he returns his hand. eo esd oS

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we LS 0- he dle be ret .a wo ile 1er on ne- the eft ed ne aV= ly, }** the uce. But : yer= | ned ests no- nd- mo- When he grasps your arm, the medium presses around it a piece of lead concealed in the palm of his hand ~ Out of Spiritualism of their many “manifestations” Author of ‘‘True Ghost Stories,” etc. Returns it? What he does, in reality, is this. He slips both feet forward and crosses his knees, the left knee being on top.. Then, when he requests the man on his right to hold his hand again, he allows him to hold his left wrist—the one that is holding the wrist of the man on his left. The right hand is now free. The man on the left cannot tell that the hand has been removed, as, _ in- deed, it has not; and the man on the right cannot tell that any change has taken place in the position of the hands, since he grasps a wrist which the medium tells him is his right hand. Since there is only one knee, the trick cannot be discovered if an investigator feels the | other knee. But some people will tell you that they have received ‘“‘spirit touches” The medium has removed his hand, but the lead clinging to your arm gives the impression that the grasp continues up_on the arm. In this way the man in the middle was able to tell instantly if any hand was removed. A curtain was then pinned over the bodies of the medium and of his investigators. Presently manifestations took place. How? Under cover ofthe cloth, the medium abstracted from: his pocket a small piece of lead about the size of his -hand. He bent this tightly around the arm of the man next to him, giving him the impression of being held by that hand. Thus the hand could be removed and the impression re- main—the left hand still grasping the arm lower down. Both hands were thus felt, while, as we have seen, only one was actually employed in holding the man—the other being free to play musical instruments and produce other “‘phenomena.” ' Ofcourse, various levices have been resorted to ‘in an endeavor to prevent mediums from~ producing ‘phenomena’ fraudulently, particularly in dark circles. Some of the Devices - Among these may be mentioned rope-ties of all kinds, ~. chains, padlocks, handcuffs, etc., and espe- cially various ways of hold- ing the medium so that he cannot escape. These are known as holding tests. The aim of the medium is while they knew they held both hands of the medium securely all the time the manifestations were going on. In this case, the medium blindfolded the sitter, if the sSance was held in the light, and with his teeth ex- tracted a long feather from under his vest, and with it produced soft “spirit touches’? upon the head, face, and hands of the gullible person. A Famous Feat of the Eddy Brothers An ingenious ‘“‘holding”’ test, made famous by the Eddy Brothers in their so-called “light séances,’’ was carried out as follows: Three chairs were placed in a row in one corner of the room. The medium sat in one—the right-hand one, as viewed by the spectators. The other two were occupied by Investigators. The medium and the third man (in the opposite end chair) then grasped the arms of the man in the middle, one hand on the wrist and one hand high When the medium’s hands are held securely he some- times produces “‘spirit touches” by means of a long _ feather drawn from beneath his waistcoat with his teeth to evade these and, by re- leasing one hand or foot, to produce ‘‘phenomena’”’ with the free member. | Sometimes ‘‘phenomena’”’ are produced a long way from the medium—so far, indeed, that the sitter feels sure he could not have reached that spot, even had his hands been free. In such cases, the medium has produced from his pocket a.long jointed rod, known as a “reaching rod,” and after opening it is enabled to reach objects four or five feet away—to ring bells, shake the tambourine, etc. The above are some of the simple methods by which fraudulent ‘“‘physical mediums” bamboozle their sitters. I do not wish it to be understood, however, that I do not believe in any genuine phenomena of this kind. On the contrary, I am quite convinced that they sometimes occur. And it is for this reason that we “‘psychical re- searchers” are so anxious to eliminate the fraud. Spurious money doés not prove that no genuine money exists: jt is the same with spiritistic phenomena. I merely wish to, warn would-be investigators of possible disappointments.

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BERECUUALEIT , ~© Publishers, Photo Service Twas with a Goad She Did It HEN this woman war worker had to~ lug'three heavy barrels for some dis- tance, she remembered seeing farmers’ carry boulders: on a. “stone-boat,” and:rigged up ‘one -of her own. She rolled the barrels upon it, attached it to a Ford, and started off, just as you see her here. ae “ea © Press Illustrating Service Belgium Moves to Staten Island YVREN the Belgians fied from: their invaded country, some .of them did not stop till they reached New York. And then they settled down in Staten Island, starting another foreign colony in already half-foreign New York. Some of these strangers in a strange land have become Amer- icanized, but others keep their Belgian habits and customs. The man shown here brought his milk-cart, cans, and three dogs with him. He earns his living here, as he did over there, delivering milk. A trip to this Little Belgium would be just as interesting to strangers sight-seeing New York as a trip to dark and dingy Chinatown. The quiet Belgians on Staten Island lived through the first terrible days of war and could tell many an interesting tale. Popular Science Monthly Bicycles Come Back to Their Own HEN motorcycles arrived, the faithful bicycle was for a time neglected. But when the newness of motors had worn off, people began to look up their old bicycles. The one shown here is generously helping out a motor. This motor is used to generate electricity for the wireless outfit to which it is attached. The wireless man had no way of starting the motor, so he got out an old two-seated bicycle, took off the wheels, and mounted it on stands. Then, by a series of gears and chains, he connected the bicycle with the motor. When he climbed on board and started to pedal, he started the gears which, assisted by the chains, turned the motor, and so generated electricity. A Cargo of Wood that Shipped Itself WEDEN wanted to send four huge car- goes of wood to Den- . mark. Had this de- sire seized her before August, 1914, ‘ships would have fought for the job. But the war was: on, and all the ships that hadn’t been ‘sunk by submarines were too busy to bother with wood. As a result, Sweden’s wood lay for months in warehouses, _ waiting patiently for - idle ships. But the ships were never idle. One fine day’ when wooden ships - grew popular, the owners. of the woodpile decided © ‘to make. a huge raft out of it and then tow it off. -As the wood was cut in long, thin strips, the job of piling it to- gether was a difficult one and lasted nearly six months. The wood was held together by steel cables and wires not one beam slipped out during the trip. The raft was about fifty feet wide and four ‘ hundred feet long. It stood ten feet out -of water and fifteen feet below... When it was finished a crew of seven men were assigned to it. They watched -for possible breaks inthe Copenhagen. This- picture was taken just after the re- , markable'raft® reached “Denmark: 2% so well arranged that wires while two small ° boats towed her to. not put pro orb infl to | cou ties fou cur thr

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me off, ich bOr,. and he the ~ult arly ires hat © The Sense of pwr of an Orange N orange has admirable ideas of right and wrong. He does not believe in cheating the poor public. One young orange hang- : aie ing on a tree watched disap-. © Wester Newspaper Union GZ Gye Wy Ke oe A Beet that Tried to Be a Parrot F the curator of a museum had found this fellow first he could easily. have convinced. us that it was some prehistoric bird be- longing preferably to the Psitiacus erithacus, or parrot, family. But it fell into the hands of beet-grow- ers—which, of course, is natural, since it is a beet. Its great resemblance to a par- provingly as dealers charged ex- ' Upon My Sole! rot attracted the attention of the orbitant prices for his brothers in farm-hand who dug it up, and influenza days. An idea occurred GHOES of all kinds and sizes are smilingly accepted by he handed it over to them. The to him. the girl in the picture, who sorts them and then sends growers dressed it up with a glass He absorbed all the sunlight he them to Belgium. She is sitting in the midst of enough eye, put a ribbon around jts neck, could, drew from his tree quanti- shoes to fill two large freight-cars, and yet she smiles for and trimmed the beet-tops into -ties of nourishment, and grew and more: for there “are still many shoeless feet over there tail-shape. grew and grew, until picking-time in Belgium. They then exhibited him as an found him eighteen inches in cir- The war is over, but the damage done by Germany will example of what unusual, am- cumference and weighing fully be felt for a long time, so we must continue shoeing the bitious beets grew on their truck three pounds. Belgians, as we did in war-time days. farm. Putting Him on His Feet Again ACCORDING to Robert W. Chambers, author of many best sellers, ‘‘Valeries” stir things up considerably when they appear. He seems to have figured them correctly, for one Valerie —not one of his fair ladies, but a large freighter—recently caused much commotion in New York harbor, As she steamed down the bay, she bumped into a 726-ton schooner whose name is Dustin G. Cressy. Dustin toppled over without a struggle, but Valerie proceeded calmly on her way, unharmed. Fortunately, the crew was saved, but the ship needed much sal- vaging. The picture shows several men working on Dustin’s side, helping to stand him up again. This little drama was enacted in full view of the Statue of Liberty, who frowned on it with troubled eyes. Fa H ee © International Film Service ~ sn 7

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Popular Science M only : Ferrying War Material to the Tommies In boats the Germans didn’t know existed Right under the nose of German fliers and U-boats, the British © established a ferry at Richborough, a town on the river Stour ERMAN fliers and U-boats kept a sharp watch on the British Channel coast, and made numerous attacks at different points from which, they suspected, shipments of war material to France were made. Realizing the seriousness of the situation, the British government resorted to a ruse which succeeded remarkably well. About three years ago, a Channel train ferry was estab- lished at Richborough, a small town amid the salt marches fringing the mouth of the river Stour, which Photographs © Injernational Film empties into Pegwell Bay, between Ramsgate and Dover. Knowing that there was no harbor at that point, the Germans never took the trouble to raid this part of the Channel coast. The British government built extensive magazines at Richborough, and established a ferry-house with an _ adjustable platform provided with a double track. Three ferries, each with a capacity of fifty-four fully loaded British standard railway cars on their wheels, or the He Needn’t Go In When It With his coat like a tent, covering both rider and steed MOTORIST will not make for the nearest garage when rain begins to fall; for his seat within the car pro- tects him from actual contact with the _ Yain. But riders of bicycles and motor- cycles have no protecting covers and are unmercifully wetted by sudden showers. The result is that they must seek shelter, and continue their journey only when the weather gods see fit. This unpleasantness in cycling has . been overcome by a recent -invention. Cycling enthusiasts have every rea- son to welcome the combined cyele raincoat and cover devised and-patent- ed by Roy. V- “Creery of Wisconsin. The waterproof coat is large enough to cover not only. the rider, but also_ the handle-bars, pedals, driving mech- anism," high’ ‘Silas? which may be turned up and fastened in that position, pro- tects the head and neck of the rider. The coat opens on the side, and is - ment covers the saddle, of the wheel: ‘A " about this-rain- held together securely by snap buttons. The closing seam of the garment is made water-tight by providing for two flaps on one edge, between which the other edge is placed..when the coat.is _buttoned. The coat has no sleeves. ‘To-enable the wearer to : unbutton the fastenings, a side opening, protec- ~ ted by a flap, is pro- vided. The front part of the ‘roomy and tentlike gar- handle-bars and ..- is attached to them and to the front fork. . There is noth- ing complicated coat. Itis easily put over the shoulders of the ef Over Seesers Three boats, each ‘carrying fifty-four cars, carried loaded trains © . across the Channel, where they were transshipped to French railways. equivalent in locomotives, tanks, auto- mobiles, etc., were placed in the ser- vice. Alternately they took aboard — their quota of cars: loaded with war material, and carried them to France, where the trains were transshipped to the French railway lines and speedily taken to the front. The ferries returned from France with empty trains. The average time required to re- move the empty cars from the ferry and to run loaded trains on the boat was about thirty minutes. Rains rider and the driving and steering mechanism of the wheel and quickly fastened to the front fork and the handle-bars. The ridercan get out of the garment without detaching it from the machine. Frotected by this ample garment, the cyclist can brave the elements without fear of a drenching Mer I: r li it is City and junk W was was He h one, man hand and Herr likel; how tives how and long then for i acqu uses of tk roun and and tran they Sonk are spec mou reac it. rails to 1 gras) side, loos fron

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ge" rd ar id he th 2, 5 See ) ve ew” ~ farch, 1912 then makes an offer

Buying Railroads for Junk This man purchases bankrupt railroads, scraps them, and then sells the material in every part roads just to scrap them. It seems - like an impossible proceeding, but it is not. Herman Sonken, of. Kansas City, buys railroads, tears them up, and sells them as a sort of glorified junk. [tents ios if-you can, buying rail- train travels slowly, there is practical- ly no danger of the rails spreading and causing a wreck. By this method it is necessary to have a crew of only twenty men to pick up the rails, where ordinarily it would take thirty or forty. of the world make excellent fuel. The farmers find them even more satisfactory to burn than coal. : ae A large amount of the railroad equipment that has been scrapped by Mr. Sonken is now over in France. He marks the rails and

‘When Mr. Sonken was a boy, his desire was to own a railroad. He has not only owned — ” one, he has owned many. When a rail- road gets into the hands -of a receiver aid has to be sold, Herman Sonken is likely to buy it. + First he finds out how many locomo- tives, how many Cars, how many ties, bridges, and roundhouses be- long to the road.. He

Hoisting rails weighing 700 pounds. loosened, and the train travels over them, pick- ing them up from behind cars with his name so that they can be iden- tified. Only recently a young man from his office, who was fight- ing in France, recog- nized some of the Son- ken rails. Parts of Sonken railroads may be found in practically every country in the world. 2% One that he bought was sent almost bodily to England. With the thirty-six miles of rails went six freight-cars, two combination The rails are

for it. When he has acquired it he scraps it. The cars he uses to transport the other equipments of the railroad to its destination. The roundhouses are torn down, scrapped, and placed on flat-cars and in box-cars, and when he has used these cars for transporting the best of the material, they in turn are scrapped. How the Rails Are Handled The wrecking is all done with Mr. Sonken’s own machinery. The rails are taken up by a machine built specially for the purpose. <A crane mounted on the end of a 30-foot car reaches over a 33-foot car in front of it. The bolts are taken out of the rails, and they are then hoisted on to the car by machinery which grasps them through the bolt-holes. The rails are loosened on the in- side, and the train travels over the loosened rails and picks them up from behind.’ Since the wrecking

The bridges are taken down, and, if in good condition, are sold to other railroads. The cars that are in such condition that they may be repaired are sent to the “hospital,” refitted, and sold to other railroads. If they are in a very bad condition they are simply sold as scrap metal. Locomotives are overhauled and resold wherever it is possible. When a road has been completely dismantled, and nothing remains but the ties, they are sold to the farmers along the way at a rate of $90 a mile. These are treated with creosote and

Bridges from a railroad scrapped by Herman Sonken, The upper picture shows a bridge before it was dismantled

39 passenger-cars, three locomotives, and six steel bridges. Unlike most business men, “live ones’’ are not what Mr. Sonken wants. He always waits until the courts have written the obituary of a railroad. So, although he has owned many roads,—seven or more,—he has never operated one, and all but, one of. the seven were long since junk. The Exception to His Rule The exception was a short line in Iowa. Mr. Sonken was called in to- look at the property. “As a railroad it’s worth nothing to'me,”’ said he, “but. as junk I'll give $21,250.” He got it. Then, before salvage operations could start, he was offer- ed $250 more than he had paid by a man who wanted to keep the breath of life into the line. It was charac- teristic of Sonken that he took his $250 profit and let the road live.

Box- and flat-cars and other equipment ready for shipment: There are twenty acres of space filled with valuable junk

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Popular Science Month} ; No chains, slippery road, too much speed —that’s the formula for the perfect smash. The results, when followed faithfully, may be seen here—wind-shield and top broken off and two wheels missing. ‘The car turned completely over in the smash ‘‘Always room for one more’”’ is the motto! of the moving-van crew, and they usually! finish off by lashing -your-pet- bit of fur-! niture on: behind, making a topheavy load How Automobile The Case of Safety First = — a as wv » f ‘ —_ os } ‘ ae, Oe | See Mem Photographs ©) Publishers’ Photo Servies Poetic justice! The big car tried to crowd the little fellow into the ditch, and’ got the worst of it Another case of ‘Forgot my chains.”. Adda Both cars had their headlights on full when they met, and both little too much speed and a sharp turn, and - drivers, blinded by the other fellow’s glare, misjudged the distance. you don’t need imagination to guess the rest The crashing head-on collision followed as a matter of course 40

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No, the taxi didn’t get tired and try tolean against the tree to rest. This ismerely another example of the motorists’ great sin of omission—no chains ‘Usually the center of gravity is kept be- low the danger line; in this case they got “too much stuff atop, and the driver spilled the beans by making too short a turn Accidents Happen -ys. the Careless Driver Photographs © Publishers’ Photo Service Tried to beat the train. If he’d won he’d have saved thirty seconds. For this he gambled his car and his life ’ ey a ee ee ee a ——— ————— The driver of this car, which was rammed amidships by the Poor headlights were the cause of which this truck in the picture, turned out of a lane into a busy main is the unpleasant effect. The driver simply road without looking to see whether the way was clear tried_to turn a corner before he got to it

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— If the Bell Rings You’ re a Bad Shot Instead of announcing a bull’s-eye, the ting-a-ling says you're a trigger-jerker . By Captain Edward C. Crossman, U. S. A. pour ninety-five per cent of ‘ successful rifle or pistol shooting . lies in the smooth release of the st#iking mechanism of the arm that fires the cartridge. Trigger “squeeze” instead of jerk is the hardest thing to teach a beginner, and it is the first thing ‘he forgets when he shoots hur- riédly. or under excitement. He is » not alone in this; for the veteran shot géts spells of fudging or flinching, and they usually go hand in hand with convulsive pulls of the trigger. The Novice’s Dread of Noise The novice jerks the trigger, displacing his aim and sending - his shot wild, usually because he’s afraid of the noise and the kick of the gun, and also because he tries to make the shot go when the sights are just right, and, in the parlance of the rifle shot, he “quits holding and pulls the trigger.””. The experi- enced shot can make his shot go when the sights touch the spot, but the recruit has to arrive at this stage by way of the gradual trigger squeeze. Trigger-jerking is one of the most difficult tricks the instructor has to overcome. At the Small Arms Firing School of the Army, at Camp Perry, Ohio, the pistol instructors feel that, when they’ve got the student officer past this jerking period, he lacks only practice to make a good pistol shot. Except by the wild shooting of the learner, the trick is hard to detect.’ If the gun is. empty, he doesn’t, as a rule, jerk the trigger. If it is loaded, the recoil usually covers up the move- ment produced by his yanking habit. Veteran instructors ‘‘get the goods on him” by the old trick of making him think he’s pulling the trigger of a load- ed gun when it is really empty, and noting whether the arm moved as the striker fell. This exposes without curing the trouble. To Cure the Trigger-Jerker The best way to cure it is to “catch "em young,” and to train them so carefully in the preliminary practice with empty rifle and with small- caliber gallery rifle that the careful trigger squeeze is accomplished with- out thought. The most valuable accessory yet invented for detecting and demon- strating to the shooter himself bad trigger squeeze, is the Coleman aiming device, which infallibly and violently rings an electric bell when the shooter jerks the trigger instead of squeezing it. It is in use by the United States Army, having been adopted by the General Staff. It consists, primarily, of a slidable _frame carrying a steel peg a trifle smaller than:the interior of the bore of the rifle. The steel peg is connected with one pole of a dry battery; the SLIDING BAR AND MAGNET If he jerks the trigger or moves the rifle the merest trifle, a bell rings. The device that accomplishes this, the invention of an army colonel, is very easily made other pole is connected by a temporary wire with the barrel of the rifle. The shooter takes aim at a minia- ture target mounted on the apparatus —a target reduced-to the proportion of the outdoor target at some given and common range; then, when he has steadied his aim, the instructor moves the frame carrying the steel pin or peg until it slips into the muzzle of the rifle. It is a trifle smaller all round, and as long as the rifle is held steadily it does not touch the bore. With the steel pin protruding into the bore, and the rifle held steadily as the rifleman aims, the instructor closes the electric circuit, save for the gap between the steel pin—one side of the circuit— . andthe barrel, the other side. The least jerk of the rifle muzzle will move the bore against the steel pin, close 42 the circuit, and ring an electric bel] that is part of the apparatus. Then, with all this cooked up for the benefit of the learner, he is told to aim care- fully and squeeze the trigger ag if firing an actual shot at the target. Ringing the Bell with New Meaning If he has mastered the trigger squeeze, and lets off as he must to do accurate shooting on a real range, the muzzle does not move, the circuit is not closed, and the bell does not ring, If, however, he jerks the trigger or moves the rifle the least bit in let- ting off, the bell buzzes merrily, and bystanders hand him the merry ha-ha. Thereis no alibi —no bad cartridge to blame, no puff of wind, no cant, no mirage. He didn’t get off with a smooth trigger squeeze, and the bell told the tale—told the same tale the target- marker would havetold, without allowing the various excuses usually dug up for bad, shots when .in actual range practice. - After a séance of preliminary train- ing with this deyice,.with its “bawl- ing-out”’ bell to tell to all men the tale of the trigger-jerker, the recruit either learns proper trigger squeeze beyond all chance of forgetting it, or else he’s without the pale of possi as a rifle shot. The relation between the steel pin and the bore depends on the skill of the firer. The inexperienced marks- man couldn’t even hold steadily enough to avoid closing the contact with a pin as near the size of the bore as that which the crack shot could use without trouble; but, once he’s learned how to hold steadily, the pin can be so large as nearly to touch the bore, and still never close the circuit when the trigger is let off. The device, the invention of a colonel in the army who understands the difficulties of rifle training, is cheap to make up and simple to operate, the total accessories necessary for the. production of rough but serviceable copies being merely a dry battery, a bell, a little wire, a nail of the right size, a piece of 1x12-inch pine board. Add a simple switch for closing the circuit when the aim has steadied down, and you are all ready to begin the test. Popular Science Monthly Be Fee oe ma of | mo tail eve pla ant bos nec tric alt

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bi yer ell che et- ld, the ly ots nge in- wl- sale her ond else ties pin ll of rks- tact the shot nce the y to over r is fa ands heap rate, r the. able y, a right yard. the died yegin

“March, 1919

No Catching Crabs with These Oars O you know what “catching a crab’’ means in the lan- guage of sailors and fisher-folk? Watch a person unskilled in the handling of oars attempting to row a boat in comparatively still or slightly choppy water. He may make the first-pull bravely; but on the back stroke the blade of one of the oars catches the crest of a little wave, and al- most invariably the oar is lifted out of the oar-lock. That is called “catching a crab.” Charles J. Olson, a Brooklyn inventor, has recently ob- tained a patent on a device which makes it impossible tor even the most awkward amateur oarsman to do this. On each side of the boat a slotted plate is attached to the nwale, and the shaft of the oar is fastened to a retaining plate which allows the oar to move forward or backward and to turn, but keeps it from becoming detached from the boat. Each of the oars has above the gunwale a sleeve at- tached to the shaft of the oar, and the two sleeves are con- nected by a bar which is pivotally connected with an eccen- tric plate attached to the sleeve. _ In rowing, the oarsman grasps the bar and pushes it alternately forward and back. At one motion the oars It is probably more ~ efficient, but how does aie one feather the oars? ~

take the pressure of the water and propel the boat, while at the back stroke the eccentric of the sleeve gives to each oar a quarter turn, bringing its edge against the water. At the next stroke the flat of the oars is again turned to take the pressure of the water. The turning motion is produced by the eccentric plate engaging pins in a stationary plate also attached to the sleeve and upon which the rotatable eccentric plate rests. By properly stopping the position of 'the eccentric plate in relation to the stationary plate the boat may be rowed forward or backward.

The variation of depth of water over which the boat is passing is recorded on the dial before the helmsman’s eyes The Dial Registers Soundings DEPTH registering mechanism patented by A. O. Mason is in- closed in a water-tight casing, towed along the bottom. The mechanism comprises a pivoted, cir- cuit - closing lever, the long end of which is adapted to move over the alternated contact and insulated sections of a rheostat. The short end is connected with a flexible diaphragm set into the wall of the casing. Any variation in depth re- sults in a corresponding inward bulging of the diaphragm, which is transmitted through the levers to the circuit-clos- ing lever-arm moving it across the plates of the rheostat, thereby transforming the water-pressure on the diaphragm to electrical resistance, which is transmitted to an ammeter in view of the helmsman.

Propelling and Steering a Boat with a Feathering Paddle-Wheel O the list of devices for propelling through this sleeve, which by means plane and fixed in any desired position. and steering boats, a New Jersey of a cone-gear is connected with the At the lower end of the shaft, which inventor, David Lindsay, has added a_ driving mechanism. paddle-wheel.with feathering paddles, extends into the paddle housing, is a Through this sleeve runs a vertical ring with a cam groove which consists to be operated in a horizontal position, shaft having at its upper end a lever of an upper and a lower section, con- submerged under the boat. _ The paddles are pivoted in the hub of the paddle-wheel, with their outer ends in a = . ring. The journal studs at the inner ends of the pad- dles are pivotally mounted in-a hub-like casing which forms the lower end of a tubular sleeve that re- volves in a packed journal set.in the bottom of the boat. The paddle-wheel re- ceives its rotary motion By means of this paddle-wheel you may steer the boat in any direction —

which may be turned in a horizontal nected by slanting grooves. Crank arms extending from the journal studs of SHDEX the paddles engage in this <a groove by means of anti- z friction rollers, and, as the paddle- wheel revolves around the stationary shaft; the crank arms, moving’ in the cam groove, impart a quarter-turn to the pad- dles during one half of their rotation. CANS CONTROB SFEATUHE RING ee eee = RARDLES =

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Gerrit Van Daam is one of a number of inventors who be- lieve that a parachute can be worn on the head. He has shown a keener realization of the difficulties of escaping from a crippled machine than -most inventors. His inven- tion will work, while their con- trivances are usually suicidal. & OR the same reason that sailors FF are not responsible for the adop- tion of life-preservers and are notoriously poor swimmers, aircraft pilots set their faces against safety de- vices. ~The parachute is almost as old as the balloon; yet no aeronaut would use it except to make farmers at county fairs gasp in astonishment at the sight of a man releasing himself from a fire- balloon, stepping into space, and float- ing down safely, slowly, and grace- fully with a giant umbrella. In the great war of the nations we saw the first wholesale use of the para- chute by officers who had been sent aloft in captive “sausage” balloons to watch the effect of artillery fire on the enemy, and who had to jump for their lives when the hydrogen-filled en- | velope by which they were supported ‘became a target for incendiary ma- chine-gun bullets fired from hostile airplanes. Time and time again, they had seen a comrade drop from the clouds with sickening swiftness. They had seen brave Lufberry un- Parachuting to Safety Why it is hard to provide the right kind of parachute to save brave men whose flying- machines have been crippled By Waldemar Kaempffert = The parachute is usually attached to a harness worn by the pilot. This pic- ture shows how the harness is tested. Van Daam knows that the parachute must be fastened to a body-harness; he would use the head merely as g place to carry the parachute. He makes sure that the wind will open the umbrella, for he provides openings in the helmet.that cannot be obstructed, gas-supported craft a man has a cer- tain freedom of movement, for which reason the act of “stepping over’ - is‘ no more difficult than leaping from a high roof. In an airplane it is otherwise. Although he can. unbelt hiriself, rise from his ~seat, and leap overboard, the problem of providing him with a trustworthy strapping himself and leaping overboard from his ignited craft after an encounter with a German armored plane. They had seen men vainly struggling to right machines the controls of which had-been shot away. And yet, they -persisted in rejecting the only. form of life-preserver that f could possibly be used. Reason Behind the Prejudice _Behind this unwillingness to equip the airplane with an ob- viously necessary safety device lie both prejudice and_ solid sense. It is one thing to drop from a balloon or airship with a parachute—quite another to drop from a_ flying-machine. In a the front. offered five hundred dollars to the Aero Club of America, which sum is to be awarded as a-prize to the inventor who produces the best means of enabling a man to escape from a disabled flying- machine by means of a parachute. A committee has already been appointed by the Aero Club of America to formulate the rules of the contest and to pass upon the devices submitted. $500 for a Dasinishoa Prize IEUTENANT LOUIS BENNETT, of the Brit- ish Royal Air Force, was killed in a flight at His mother, Mrs. Louis Bennett, has The POPULAR SCIENCE MONTHLY’S article on parachutes gives to inventors a clear idea of the problem that confronts them, and also indicates the means that have been suggested in the past to provide an efficient safety device. care to enter the contest should communicate with the Aero Club of America, 297 Madison Avenue, New York City. Those who It’s Supposed to Work in Air and Water David Williams Ogilvie invented this life-preserver to save a man not only from being dashed to pieces, but also from drowning. The aviator is to wear a “foundation” garment that re- sembles a one-piece bathing-suit, and over this a double-walled rubber suit, which can be blown up with air. Ogilvie thinks that the air will miracu- lously help to break the fall if the para- chute should fail to work. The para- chute (too small to be of any service) is fitted to a collar and to ribs like those of an umbrella. Just raise your arms and the parachute opens. But there are so many things the matter with Ogilvie’s invention that we really can’t begin to enumerate them all here. 44 Popular Science M onthly auto! for tl has 1

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Cer- lich er” > ing ane pat, of thy \ a BRET ER Sea? ia), yh 3 if : But It’s iE Only 4 a Dummy This photograph of Baron Odkolok’s dummy (see _pic- ture below) coming down in safety after the cannon has been automatically fired seems to make out a case for the Baron; but it is our opinion that he has not even begun to nibble at the problem. life-preserver is accompanied with grave mechanical difficulties. The parachute must be extraordinarily compact when-folded; it must be stow- ed away so that it will not hamper the pilot; it must not retard the machine in flight; it must not foul. the rigging at the crucial moment. | Mechanical Difficulties But this is not all. The flight of an airplane is mechanically so different from the drifting of a free balloon that Would It Work with a Man? Baron Odkolok of Paris is here shown ad- justing his invention to a dummy seated in a dummy machine. In the bundle behind the y the parachute is contained. Like most inventors who have busied themselves with making flying safe, the Baron thinks that ‘everything depends on the parachute-releasing mechanism. He connects the parachute rope with a small string, and the string in turn With a little cannon. The aviator unbelts himself, rises, fires the cannon, and thus re- leases the parachute. See the picture above. it may be necessary to jerk the pilot out of the machine by means of the parachute itself. When, for example, the controls of a machine have been shot away and the ma- chine drops in a flat spin, the aviator who has leaped overboard may find himself overtaken by the plane, and his parachute torn to shreds by the propeller. What of the Peace Machine? Similar objections might be raised against the use of life-preservers at sea. No one demands that a life- belt shall-save an ocean liner’s passenger in every perilous situ- ation; neither should a parachute be expected to. save an aviator in the most freakish. of . accidents. In warfare, it is true, machines are shot down from the ground, in which case there is no chance to use a life-saver. But what*of the peace machine? What of the thousands of machines in which: zealous young men learn how to fly? What of the mail- carrying machines? How They Land Sometimes When a balloonist “steps over,” his heart is in. his throat, even though the parachute has opened with- a roar. Over the battlefield a hostile machine- gunner in the air may try to pick him off during the slow descent. And even though he escaped the machine-gun bullets, he might find himself dangling helplessly from a tree in the branches of which his drifting life-preserver has become entangled. Artillery officers who went up in balloons to observe the effect of gun-fire were taught how to use the parachute in real schools. Mr. Calithrop, an English engineer, advo- cates similar training for airplane pilots. 45 “ The Parachute ‘Is His Hat McLaughlin, an American inventor, proposes to have the aviator carry the parachute on his head. We have taken his idea and improved it so that it may conceivably ; work.. We’re not sure but the aviator’s neck would be broken when he is yanked out by a parachute that suddenly opens in the 120-mile gale created by a swiftly dropping machine, and so we have attached the. parachute sling to the aviator’s shoulder-harness. We would pack McLaughlin’s parachute in a_ headpiece, streamlined like an airplane fuselage. ‘The shell forming part of the streamlined para- chute bundle falls off when a button is pressed. The parachute, open as its mouth, catches the gale created by the falling machine. A far more valid objection is the weight of even the lightest parachute. Let it not be forgotten that an airplane, and above all the 120-mile-an-hour single-seater, is a structure in which ounces must be saved; otherwise it cannot fly high or fast. Clearly, a* parachute weighing thirty- or eyen forty pounds may not be added without lowering the machine’s flying efficiency. It is obviously difficult to mount the parachute on a flying-machine of the pusher type—that is, a machine on The Way the Germans Did It The Germans seem to have been the first to use the parachute in actual battle. Time and time again it was reported that their airmen were equipped with such aerial life preservers. A few of them certainly were. Here we have one of their crude devices —an umbrella folded. into pillow form and attached to the usual aviator’s harness. How well this worked, we don’t know as yet,. because no official reports on the sub- ject have been published by the Germans.

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which the propeller is mounted in the rear, as in a steamship; for the para- chute may foul the under-carriage in the process of opening. With a trac- tor type of machine, however, the para- chute can be housed in the rear portion of the fuselage. All things considered, the best type of parachute for air- planes would be one in which the parachute is launched upward. Zeppelins Had No Parachute So far as we have been able to determine, the Zeppelins were not provided with any form of parachute, despite the fact that it would be far easier to leap overboard from a giant dirigible than from an airplane. The BODY HARNESS eb QUICK-RELEASE I BUCKLE PARACHUTE RELEASE ROD- “Ax! AND LEVER . Most. inventors have failed utterly to realize what a veritable storm is ereated by a high-powered machine, whether it -speeds on normally or whether it falls like a bullet. They . seem to argue that the whole problem consists in providing some push-button releasing device that will free the aviator and the parachute in a perilous moment. \ SAFETY opy 7 HARNESS horror of twenty-two men burned to death two miles in the air, as the result of a single flaming bullet which has found its mark in the huge volume of hydrogen with which the envelopes are inflated, can be imagined. No won- der they often leaped overboard in the hope of finding a mercifully swift ex- tinction below. Even the man in an airplane that has been crippled has a better chance of escape than the stricken members of a.Zeppelin that has been hit; for time and time again air- planes, by reason of their inherent stability, have actually reached the ground in safety, even with their con- trols shot away. Will the Parachute Open? The man who drops from a balloon with a parachute abandons himself to a precipitous fall, placing his con- fidence in the opening of the umbrella in time to break his fall. Parachuting of that kind is out of the question from an airplane, as. a general rule. A mod- ern airplane, even in straightaway flight, travels at a speed of from 90 to 120 miles an hour. When it plunges to the ground its velocity is certainly no less. . Simply Pull the Lever and Drop to the Earth in Safety Every airplane parachute is attached to the aviator. Means must be provided to release the aviator so that the parachute may open. Here is Mr. Calthrop’s device. The ends of the Pa How Calthrop’s par- achute works in an actual emergency. Popular Science Monthly The inventor who has unquestion. ably given the airplane parachute the most thought, and who has demop. strated the correctness of his view, | most conclusively by the severest im. aginable tests, is an English engineer Mr. E. R. Calthrop. Those who remember the earlier tragedies of flying will recall that one of the firgt Englishmen to fly was the Honorable Charles Rolls, whose name jg identified with the Rolls-Royce ears Rolls bought a Wright biplane of an early model—g machine built at a time when very little was known of the enormous strains to which sup. porting surfaces are subjected in flight. He lost his life jn 1910 because of some structural weakness. Result of His Friend ’s Death Calthrop was a friend of his, It was the tragic death of Rolls that impelled Calthrop to concen- trate his. engineering attention on FOLDS OF PARACHUTE METAL CASE OR CO FLEXIBLE ROPE CONNECTING), DOTIOM COVER SAFETY, HARNESS straps that encircle the aviator’s body are so fastened to- gether that by pulling the lever the ends of the straps are freed. Thus the aviator may detach himself from the harness. the invention of a parachute that would -meet the requirements of the aviator. Calthrop has patented several types of parachutes. The accompanying illus- trations picture the details of his most important designs so clearly that it is unnecessary to elaborate on them here. For the immediate purpose, it is suffi- cient to explain that in its more To Save Man and Machine Stick a closed umbrella through the top of your machine and the handle into PARACHUTE the mouth ofasmall SUPPORTING cannon; and you are applying the ideas of George Giem. George has that if the engine should stop, the gun goes bang! and the parachute is discharged. But’ suppose shuts off the motor when gliding down? A locking device prevents’ the gun from going off. It i G TRIGGER is clear that George t RELEASE really does no know very much about the problem. the gun so arranged { George March. a rov i folde each 2 connec shock-: feet lo ~ tered i sling, 2 Accc "whole two an no sh¢ In: unf achute effect inclose may 0 openin ing the It w the C: tested. top. of the T 175 fe expres possib altituc cess. feet, ing ve chine his life a safe In 1 of the chute at a fa Sarret a pil Pégou the ai

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Oven 3 s I ch, 1919 approved form the Calthrop parachute ' _gfolded compactly between two disks, cae -Bebara gee 258.48". BES uBE a pilot. each about two feet in diameter, and eonnected with the machine by a shock-absorbing sling about fourteen feet long. The only free fall encoun- ¥ tered is limited to the length of this sling, and it lasts less than a second. No Shock to the Nerves According to Mr. Calthrop, “‘the whole operation of opening takes only two and one half seconds, and there is no shock whatever to the nerves.” In unfolding, the sling and the par- achute itself fall outside of the disks, the effect being that a cylinder of air is inclosed so that outside air-pressure may not prevent the parachute from opening. Such is the system of pack- ing that the whole action is progressive. It was in the autumn of 1917 that the Calthrop parachute was publicly tested.. An officer leaped from the top of the London Tower Bridge into the Thames below—a sheer drop of 175 feet. The test was made for the express purpose of demonstrating the possibilities of the invention at low. It proved a complete suc- altitudes. cess. The actual drop was about 140 feet, which shows that even when fly- ing very low in an uncontrollable ma-: chine an aviator still has a chance for his life if he leaps overboard with such a safety device. | ' In the present year Captain Sarret of the French army tested the para- chute successfully from an airplane at a far greater height from the ground. Sarret’s machine was under control of Before the war, however, Pégoud, who first looped-the-loop in the air, demonstrated the possibilities RELEASE. LEVER. “than Calthrop’s—by RESERVOIR of an ordinary para- chute—a very much cruder contrivance Sliding head Tension spring. boldly jumping over- board with it from a single-seater. Such is the rush of air produced by a modern fast airplane that even if it were flying very low—as low, for example, as twenty-five or thirty feet from the ground—the para- chute would still be effective if it is so constructed as to pull the pilot out of his seat. Indeed, a man might thus even leave a sixty- « mile-an-hour railway train in safety. Schools to Teach Parachuting Mr. Calthrop has urged the need of schools in which aviators will be taught how.to use the parachute. It- is al- most self-evident. that, no matter how desperate his predicament, an aviator will try to master his uncontrollable machine. The parachute is not likely to be resorted to until it flashes upon him that it is his one means of salva- tion. That is not likely to happen until the machine is within a thousand feet or so of the ground. Although Mr. Calthrop has conclusively demon- strated that his parachute will operate when it is only a few hundred feet above the ground, it would be foolish to maintain that the parachute would be effective in every desperate situa- tion, or that it is not more likely to be effective at greater than at lesser altitudes. The untrained aviator will probably be so crazed by the fear of PARACHUTE CONTAINER: FOLDED MEMBERS abled craft. rear. » co PARACHUTE a forwardly inclined container, and connected by a cord and shock- absorber with the aviator’s harness. aviator is pulled, his seat and its back fall into the positions shown by dotted lines. t reservoir at the bottom of the fuselage to the parachute-container, and the hinged bottom of the container falls, so as to scoop air into the container and assist in ejecting the parachute. ‘aviator is actually pulled out of his seat. The parachute is bound to open instantly, like a sail, and to jerk the pilot out of his dis- Hence the necessity of transforming his seat into an inclined launching-way. The invention is evidently designed to meet the requirements of those situations in which the machine is traveling faster than a man can fall, so that he cannot step overboard, as from a ballo6n. It is cledrly adapted to the mod- ern plane, which is quite free from entangling appendages at the But will the invention work when the machine is stalled? - He Wears It on His Back Kaja T. Togstad thinks this solves the para- chute problem. The can that Kaja would have you carry on your back contains a spring which raises the umbrella when it is time to jump. The little insert shows Togstad’s de- vice in its inoperative position,.when the pilot is flying along, recking not of shrapnel or machine-gun bullet. The other picture shows what happens when the machine is struck the fate that is impending that he will never think of using the one possibility of escape. After all,aviators are taught at present only to fly, and not to save themselves in: an ex- tremity. For that reason, Mr. Calthrop’s suggestion that parachuting as well as flying be taught seems to us. emi- nently sane. Jerked to Safety E, R. Calthrop is the inventor of this ingenious parachute. The rush of air past a plane, which has made parachuting seem difficult to most inventors, is utilized so that the umbrella must inevitably. open in the precious fractions of a second that may separate safety from death. . The parachute is packed in When a lever in front of the Compressed air is admitted from a The

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N © International Film Service Now You Know What a “P. V.” Is _ 6 E ran into a nest of mines, but the P.V. saved us.” Thus the young “gob”. home from a foreign cruise and spinning a yarn of the perils of floating mines— ‘perils that will exist long after the armistice turns into a permanent peace. ; Asked what is a “P.V.,” he said, “Oh, that’s what the English call ’em. They catch mines’—and let it go at that. ; But now that the censorship has lifted, we can show you what a “P.V.’’—a paravane—looks like, and tell you a little about it, although the extraordinary performances of one type of this machine, made for offensive work, must remain a secret for the time being. Ca¥ One of these torpedo-shaped devices is swung out from each side of the bow of ships steaming through mine- infested waters. serve to keep the paravane out from the ship’s side, while the rudder-like contrivance at the stern, operated by an automatic depth-regulating valve, controls the depth at which’ the P.V. travels. This valve is the same sort that controls the depth at which a torpedo travels. The ‘wire rope by which the paravane is attached to the ship catches the mooring of the mine, and causes it to travel out to the nose of the paravane, where a sharp cut- ting instrument cuts the mine free, so that it. floats to the surface, is seen by the lookout, and destroyed. This is the defensive type of the mysterious “P.V.,” which saved many a ship from being blown up by mines; the offensive type is-still a secret of the British government The airplane-like wings near the head . Developing Movie Film a development of moving- picture films, a complex and expensive process under present conditions, is simplified and cheap- ened to an amazing degree by a portable apparatus invented and patented by R. P. Stineman, of Los Angeles, Cal. It is so small that the camera man can take it with him anywhere and use it wherever a dark cubby-hole can be found. The old-method laboratory in any studio costs from one to many thousand dollars, takes up a large space, requires several persons to operate it, and its. tank calls for 250 gallons of developer. The new apparatus costs only $50 for the - medium size, and the claim is made. that it costs only $1-to develop 100. feet of film. $c ae The device embraces a developing reel and three telescoping tanks into which the reel fits. To operate, the reel is placed on a station- ary winding pin convenient to the film-box, the end of the film is fastened to the center, the reel revolved with the left hand and the film guided in by the right hand on the outer edge, winding securely on the metal strip. with a metal clip and the whole developer, moved up and down rap- idly several times _ to prevent air- bells, and in about that process is completed, and the other tanks come into play. The- fim is stmt upon the reel, and . ae *How the Kwakiutl Indians Feasted OW would you like to have your dinner served in a dish eight feet three inches long? Before the white man obtained dominion in America, dishes of this size were =» -aetually used by the Kweakiutls in their ceremonial ob- : gervances. Two of these dishes were recently acquired by the Museum of the. American Indian, Heye Foundation — of New York city. One of. the dishes is carved in Feast dishes. used by the Kwakiutl Indians. The one on the left, carved to represent a wolf, is seven feet nine inches in length. These dishes were used at the great potlatches, or ceremonial feasts, of Indian chiefs 48 the form of a wolf, and is seven feét nine inches in length. , The larger one, eight feet three inches long, is in the usual... dish form. ‘The ends are decorated with carved heads of -— bears, with their legs and paws around the vessel’s rim. * Sao Although the Indian artist who ~ made these dishes from the trunk of spruce treeshad their symmetry and proportions. ° Popular Science Monthly i bs A Cheap Method of a Then the outer end ofthe » film is fastened to the reel immersed in the © twelve seconds. fixed, and ” washed « ‘ : finally dropped on a - screen in the water. but the crudest of tools, the vessels ~ areremarkable for |

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Sf ae. Sr eS Cate eS re Nite Eig _Soozn 1g i, e, n-. to im el nd ° ng ip. he » cel lip dle | the © red ap: nes sir- out ids. -is and nks hed « # ond . mn a: ater 2 tof sels a efor — try ns. ° Z March, 1919 transmitter with a mercury- Photographing Music on a Film A new kind of phonograph inspired by the reel of the motion-picture HE motion-picture has this ad- vantage over the talking-machine: You can keep it running for a whole day, and present ever new scenes, if you have film enough; but you can’t make a talking- machine disk big enough to reproduce an opera. Harry Benwell Stocks, of Northenden, England, presents us with a method of recording sound on a film, and then using the developed film to reproduce the sound. Stocks electrically con- nects an ordinary telephone vapor lamp. In the circuit of the lamp and the tele- phone transmitter is an electromagnet, just beneath the lamp. ‘ Talk or sing into the tele- phone transmitter, and you vary the amount of current that passes through ’ the electromagnet. is peculiarly sensitive to magnetism. _~» Hence, as the electromagnetism fluctu- " - ates with the sound, the lamp flickers. WIRES TO ELECTRODES a OF VAPOR, LAMP ; RESISTANCE=BOX IN —7Pop VAPOR LAMP CIRCUIT fe * MAGNET IN ; TRANSMITTER CIRCUIT The mercury are Stocks sets up a camera in front of the lamp. The camera has a shutter which is electro-magnetically controlled by the lamp.. As the lamp flickers the MOVING PICTURE ww RECEIVER. , CAMERA, i | ie Toten! a 4 MERCURY \) ania . VAPOR yt : LAMP a : TRANSMITTER. le = &3 Sy) ma - 4 ~ in 4 || SHUTTER AND | SELENIUM |} -}- LIGHT CONTROLLED. PLATE . mf t Miles and miles of music all photographed on a film like that of the motion-picture shutter opens and closes in sympathy. It is easy to see what happens. The film travels constantly through the camera, as in a motion-picture ma-. chine. Talk or sing into the telephone mouthpiece and you make the lamp I STATIONARYAND | SLOTTED PLATE flicker and, therefore expose the film. more or less. A record is obtained which looks like a series of zigzag lines. There is a -metal, called selenium, which has the property ot varying, in electrical con- yc. ductivity with: the amount PR ACHINE, of light that falls upon it. t - “Stocks utilizes this property of selenium. He makes his film pass before an ordinary incandescent lamp so that the rays pass through it. In front of ‘the film is a slotted . plate. The rays from the lamp pass through the film and then through the slot—the amount de- pending, of course, on the blackness of the lines of the sound records. The light, which fluctuates with the record, falls on a selenium cell which constitutes part of a circuit in which a telephone re- ceiver is included. The electrical current that flows through the circuit fluctuates, causing the telephone re- ceiver diaphragm to vibrate. The re- cord on the film is telephoned to you. sets oe They Take Their Flight from the Muzzles of Guns HEN fighting-ships took to sending airmen aloft instead of able seamen, it be- came necessary for an occa- sional cruising man-o’-war to have an airplane all its own. It was comparatively easy to get the plane. The big problem was how to fly it; because, with all modern improvements, airplanes are still unable to rise vertice lly. They have to get a good start, just as some of the larger birds run along the ground with spread wings before launching themselves into the air. ‘‘Mother’”’ ships (such as were shown on page 80 of POoPuULAR SCIENCE MONTHLY for February) solved the problem for fleets or squadrons large enough to “rate,” as sailors say,.such a ship; but the lone cruiser had to shift for herself. Oneingenious way of providing the necessary starting platform or run- way is shown here. The great guns and their turrets were used She’s off! The sea- plane taking flight from the platform laid on the barrels of the turret guns What looks like a fence built along the barrels of the~ guns is a founda- tion for an airplane- ‘starting platform as foundations upon which remov- able platforms could be quickly laid down or taken up. A glance at the pictures tells the story: The plane is lifted by tackles to its perch on the turret-top, the bo’sun’s whistle shrills the order to lay the track, the ship swings so that the platform points into the eye of the wind, and the big plane sails out and off. Of course, the plane on returning can’t land on the small platform; but, being a seaplane provided with pontoons, it settles down easily in the lee of the vessel, makes fast to a tackle, and is hoisted .on board very much as a life-boat would be. RETRIAL CN TEI RL MLNS ETOP SOS SSS ST par r

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Popular Science M. onthl; Chessmen Grow in Size and Ambition A Milwaukeean has great plans for their future HESS is going to rival baseball as the great American game. You don’t believe it? Well, there is a man in Milwaukee who does, and who has gone to work to make it possible. He figured that the great trouble with chess as a spectacle is that only a very limited audience can see_and be thrilled by the moves. If a game could, be watched from the bleachers at the Polo Grounds, he thought, it Making Maps of the Ocean Deeps Uncle Sam does it bY a new method AKING maps of the bottom of the ocean is no easy job. It is somewhat as if a man were to try to get an idea of the earth’s surface by drifting above it in a.balloon on a moonless night and letting down sound- ing lines or drags. Like the dry land, the ocean bottom has its mounta ns, valleys, p'ateaus, and plains. Ordi- nary soundings give a very poor idea of sea-bottom geogra- phy, since sound- ings taken even a few hundred feet apart may fail to reveal an- ocean peak rising sharply in the middle of a plain. To prevent this inaccuracy in mapping the ocean deeps, wire drags have been adopted. Thesurvey vessel steams slowly over a given section of ocean, and the drags record every Fresently they'll be as big as men and may march into the rolo Grounds as a rival to baseball would be easy to stage chess matches that would put baseball on the skids. Perhaps he’s right; but, honestly, can you vision an excited chess fan rising in his place to shout: “Atta boy! Play your knight!’ Or: ‘‘Wow, what a bone! White to mate in five moves! White in five, you poor fish!’ The Milwaukee man’s plan is to build chess pieces as large as men. variacion of depth, and indicate where more detailed surveys should be made. When this work is done out of sight of land—and therefore of “landmarks” —some sort of floating signals must be provided. J. H. Hawley, of the United States Coast and Geodetic Survey, tells how this problem was solved Florida reefs last summer. nals, although made rough materi- als, answered every need. structed of a They will be made of papier-mAché, so that the chess-players won’t get all tired out wrestling with them every time they make a move. ; Each of the chessmen is to be made in two pieces—head and base. When the heads are removed from the bases, the latter can be nested one within the other so as to fit into a trunk, the detached heads fitting around the bases. while the bot- tom was being mapped off the The floating sig- from age i ae The signal as it ap- pears when used by the map-makers of They were con- y the great ocean bed heavy center polewith a target at the top, weighted at the bot- tom so as to stand upright, and floated by three barrels lashed to the pole about two thirds of thelength down. The mooring chain was attached to a bridle at the water-line. With the aid of these signals, drag work covering 232 square miles was done in four months. Gne of the sea-going signals hauled up on the pier 50 It was the first survey of its kind made out of sight of land. .- —- —w Se 2 Be botse ot 26 2m £5 Se OCU 6p

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STORM LEVEL iy —— oom eer DRIVEWAY = RAIL. ROAD ee “This salle, t to + calinet North Holland with Friesland, will provide 4,800 farms of 100 acres sails the Dutch-government, covering a period of thirty-three years, in which American machinery and cement will undoubtedly figure It is a tremendous project of Holland’s Ninety-Million-Dollar Farm To be reclaimed from the depths of the Zuider % OLLAND is going to H reclaim 820 square miles from the depths of the Zuider Zee. dwellers. To achieve this, the thrifty Dutch govern- ment will expend a sum of nearly $90,000,000. Investigation has dis- closed that quite 90 per cent of the bed of the Zui- der Zee, when bared to the sunlight, will make fertile fields; and the plan -is to - leave the sandy areas that lie in the deeper waters un- disturbed, so that there will still remain within the heart of Holland a great internal lake, which in the course of a short while will turn from salt to fresh water dnd prove a veritable ‘boon to the contiguous agricultural regions. Presto! The Zuider Zee Is a Lake The reclaimed areas will be known as polders, and the Zuider Zee will be re- placed by Yssel Lake. The main feature, from an en- gineering viewpoint, will be ’_a massive sea-dike, which is to span the gap between the Island of Wier- ingen and the coast of Friesland, eighteen miles away to the north and east. And then a shorter but equally effective bulwark will block Amstel Diep between the southern end of the Island of Wieringen and the neighboring shore of the prov- ince of North Holland. The purpose of the dam or sea-dike is to shut out the North Sea, and to halt for all time its devastating work through the agency of its offspring, the Zuider Zee. This dike will have a width at the water’s surface of more than 230 feet, and will rise a This recovered laid will create a new-born province large enough to provide 4,800 farms of 100 acres each, and districts that will accommodate 250,000 industrious By Robert G. Skerrett great distance above the sea-level. To protect its outward face from the erosive attack of storm waves, a coat- ing -of stone slabs, basalt from Scandi- navia, will be employed. The body of & A Acre A change in the map of Europe that has nothing to do with the war on a base of brush and stone, or con- crete, with a thick surfacing of clay. It is estimated that 52,971,000 cubic Hurling a Man from the Earth to the Moon 8 the April number of the PopuLaR SCIENCE MONTHLY we are going to take up the question * of traveling from the Earth to the Moon. We create noimaginary forces, no astounding materials: we use known forms of energy. Jules Verne sug- gested the use of a cannon. That will not do, as we will show. Neither an airplane nor a dirigible can be employed, because there is no air between the earth and the moon. There is one possible engine which can fling you into space. It will be a fascinating article. Don’t miss it. 5) Zee and rented at thirteen dollars an acre feet of clay will be used in the surfacing. This clay will come from the bot- tom of the Zuider Zee, and also from the excavation of the canal that is to be built right through the Island of Wieringen in order to permit the ac- cumulating excess water in Yssel Lake to flow out into the North Sea at low tide. This canal will have a width of 3,000 feet, and will be quite 35 feet deep to accommodate deep- drafted traffic. American Machinery Will Be Used The building of the sea-dike will take nine years, and with its virtual completion will be started the first of the polders. The entire undertaking will require thirty-three years. The first polder will have an area of 53,600 acres, and wilil be available for setticment in the fifteenth year from the beginning of the sea-dike. ’ The-second polder, having an area of 266,240 acres, will be finished ten years later; the third polder, with an area of 77,900 acres, will be ready in the twenty-eighth year; and the fourth polder, of 125,700 acres, will be available to far- mers in the thirty-third year. The Dutch Government pur- the great bulwark will consist of sand poses leasing the farm-lands for an an- nual rental of thirteen dollars an acre. The great dike will have a wide driveway for vehicular traffic, and there will run parallel with this a double track railroad which will provide a short route from the province of Friesland to the province of North Holland, thus greatly reducing the distance to be covered..in delivering goods at Amsterdam or distributing imports arriving at that port. American machinery and American cement will, un- doubtedly, figure conspicu- ously in carrying out this tremendous project. ne a ei Ge RC CP OPT EOIN OT OT ee ee ey ery ees ee a a aoe ee en - £05 a on ere aN CR AE ART eM CORR Rr nat A Ai tet a aA prersor

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ae a You can avoid wastage of oil by using a tipping device like this to hold. your can when pouring out oil into.a measure This lever for controlling | the accelerator is close to the floor of the car, and is operated by a side movement of the foot, which need not be raised from the floor Doors, both on the sides and in the rear of the delivery truck, expedite the delivery of small parcels and shorten the unavoidable stops For the Mechanical of the Automobile | Raising this foot-rest provides a support for a platform for carrying merchandise CONNEC TiONS TO CARBURETOR, SNAP~ RING SNAP- HOOK AND BOW IRON~|[ AND SPRINGS RWIRE CABLE - 4 Fastening the . : bow~ends to- cae a wh ] gether with a Sa, wire cable on one side enables AND SNAP-HOOK one man un- aided, to raise the top of the automobile ROD TO wah) CIRCUIT CLOSER CARBURETOR This primer acts as an auxiliary carburetor This device utilizes the hot air in the exhaust _A fastener for carrying your watch U to heat the gas mixture on its way to the engine on the outside of your overcoat

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le ment to an automobile. it possible to take difficult obstacles Aid and Comfort Owner ual Driver Skids like these are a useful attach- They make SPRING To make the grease-cup on the rear axle of a Ford easier of access, place it at the end of a two-inch pipe i: SLOFTED “ij ~ PLATE, AND LOCKBAR This lock-bar will hold your clutch ¢ pedal firmlyin any “ desired position Here the skids prevent- - .+. _. ed.anasty. spill after a ' rear wheel had come off, while going twenty- five miles an hour A little switch on the steering wheel starts a small mo- tor which controls the operation of the brakes. A spring returns the device to its nor- mal position when the brakes are off PUSH BUTTON TO START MOTOR. A new kind of spark- plug hasalittle prim- ing cup attached This revolving brush attached to your wheel which materially will keep your tire clean and make it last longer = aids prompt ignition An awning on a spring roller is 2 convenient attach- ment to have when you are traveling toward the sun a er TLE IO = ES ca Pa 7 Safely «lata aap A A OREN — ns pee pathigeiie stn icihtis Bb hgtacdctnnipieiians TT ECs oe erin TT TS risaseapaiitieincmet aT a aoa

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The Van Hise was cut in two. Much too beamy for the locks of the Welland Canal, each half had to be floated through on its side The first step was to close the bow section with a bulk- head, and to seal the hatches and decks water-tight. In this picture you see the bulkhead that kept the: water out Popular Science M, onthly The Story of a Big Ship and a Little Lock Getting a fifty-foot boat sels were taken over by the United States Shipping Board when America entered the war. Forty- eight of these were brought out to the Atlantic seaboard. by way of the Wel- land Canal around Niagara Falls and down the St. Lawrence river before the closing in of the ice in the winter of 1917, and thirty-five more subsequent to the opening of navigation in the spring of 1918. ss Many of these vessels were longer than the locks in the canal. It was not a difficult task to cut these in half, bulkhead the open ends, and take them through in two parts. But the Charles E. Van Hise (460 feet long, (>: E hundred and ninety lake ves- This is how the bow section of the Charles Van Hise was floated on its side through the Welland Canal locks Ra Li By Joseph Brinker 50 feet beam, and 43 feet 8 inches from keel to gunwale) presented a more difficult problem. She was not only too long, but also too wide. Her beam of fifty feet was six feet more than the width of the locks. We Need the Ships Ships are needed now almost as badly as they were when the submarine peril was at its height. Hence the prob- lem of getting the Van Hise through was put squarely before the engineers of the Shipping Board for solution. They accomplished their task with the cutting of the ship in but one place. This was amidships, just asin the boats _ : tate rs through a forty-four-foot canal that had a beam less than the width of the locks. ‘But with that operation the similarity ended. The narrower boats were taken through the locks on an even keel, but the Van Hise had to be tipped over on her side and floated on her beam ends, with her deck vertical to the water. No other ship approaching the Van Hise in size had ever to be manipulated in a like manner. The engineers had no precedent to follow. - Bow and Stern Separated The bow was cut in two, turned on its side, and passed through ‘one lock of the canal on December 5 last. The Never before was an attempt made to pass a boat fifty feet wide through a canal only © forty-four feet wide

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th of tion ower S$ On and her Van lated 1d on lock The tempt March, 1919 ~d ADDED [OP- SIDES 4FT ABOVE OLD DECK NEW DECK. poysie BOTTO) 6° How the Van Hise was turned onher side. From left to -obt+ (1) As the ship would have looked onan even keel; Te on floating outside the canal; (3) the ‘ ' Gas h a t step, the No. 1 inner bottom with 250 tons of water; stern section, containing the engines ‘and boilers, was handled separately. After proving that the daring plan of handling the Van Hise was successful, -the engineers decided that the season was too far advanced to make it: safe to send the ship on her strange voyage. She is wintering in Lake Erie and will make the trip through the canal in the spring. The first step in the work on the bow section was to bulkhead the cut end, and then to make the deck water- tight by sealing all the hatches and covering all the portholes and other openings above the water-line on the side of the ship that would be under the water when the wessel was turned on her side. Over on Her Side - The next step was to mount six adjacent wood and steel pontoons about nine and one half feet long and between five and six feet deep, on the upper deck of the boat between’ the forecastle and the rise of the bridge-deck amidships. These pon- toons were mounted entirely on the deck and extended clear to the side a Pe a A wreck, you say? It. is the bow section of the Charles Van Hise, a9,000-ton steamer which was too wide to be floated through the Welland locks, and had to be cut in two and the sections floated through on their sides 4 NO. 1! AND 2 WING, TANKS.» PONTOONS PONTOONS ' sp ) ? (4) second step, Nos. 1 and 2 tanks filled with 130 tons of water (notice 26° angle of inclination): (5) third step, pontoons 1, 2, and 3 filled with water; (6) fourth step, pontoons 4, 5, and 6 filled with water; (7) all the way. of the hull, which would be under water when the vessel was turned over. The boat was now ready for the turning operation. Gradually the pontoons.and-other tanks inside of the vessel were filled with water, so that she became unbalanced and turned over on her side without any ill effects, much as you turn over in the water while swimming. The inner bottom on the side toward the turn was first filled with 172 tons of water. This tilted her slightly. Then 130 tons of additional water ballast was added in the side tanks, and finally 466 tons more was pumped into the pontoons, thus tipping the boat until she lay over on her side. In addition to this total of 768 tons of water, 135 tons of equipment was used as ballast. = Since the pontoons : weighed 105 tons, the grand total of 1,008 tons was required to turn the forward section, weighing 1,700 tons. The water and other ballast made the boat float with a draft of four- teen feet. The turning operation was done, not in the locks, but in Lake Erie near Buffalo. The bow section was first CANAL -LOCK PONTOONS over to 90 degrees, all water pumped out of No. 2inner bottom. and No. 1 inner bottom pumped down from 250 to 175 tons, boat balanced. and drawing 14 feet of water floating on side; (8) as she looked passing through lock towed upright to a suitable place. _Fhen the pumps were started, steam being furnished by accompanying tugs, and after five hours the tanks and pontoons were filled, whereupon the section rolled over perfectly on its side. It was then towed back to Buffalo, where leaks and other minor repairs were made. This done, it was towed to Port Colborne, the entrance to the canal. In the spring it will go on through the locks. Getting the Stern Through The stern section will be floated through in a similar manner. It was first planned .that the two sections should be righted before being joined together again. But now the en- gineers, F. A. Eustis, H. N. Herriman, and W. F. Powers, hope to join the two halves as they lie floating on their sides, and without putting them into dry-dock. First of all, they will calk and paint that portion of the vessel that is out of water; then they will roll her over, remove the pontoons, shift the ballast, and complete the other side in the same manner. RP GPR BOI ae ete peas ES pb PRES pig hg (EEE scorer nerionasinpeeatiennt ha RENAL A CLARA ARAL ESE A TEEN > ‘

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RIZZLY-BEARS, lions, wolves, bobcats, and coyotes “are very popular in the zoo, and in the zoo only. For in their natu- ral lives, roaming around the mountains, they are merciless mur- derers, killing cattle and sheep. ' “At the cattlé-raisers’ cry for ‘help, our: government declared war-on these’ marauders, and- in the last three years govern- ment hunters have:killed 70,713 animals. This has resulted in a direct saving of more than five ‘million dollars a year to stockmen in the Rockies. Figuring from the number of cattle saved and ‘the number of cattle-killers killed, ‘ aa > discarded. Trying It on the Rabbit HESE three men in a boat are not banishing forever from the land the two innocent rabbits with ribbons round their necks. The rabbits are simply going to act as passen- gers in the small white life-boat alongside. This life-boat has a pass- enger-car suspended within, which is so attached..that it retains .its- horizontal position regardless of the roll of the boat. The Bottom Drops Out of This Pipe whose bottom drops out that tobacco may enter. If this pipe ¢ goes dead when only partly smoked, you take off the bottom, poke the tobacco upward till all the dead tobacco drops out of the top, fill it up from below with fresh tobacco, put -back the pipe bottom, and light up. This flow of tobacco eliminates the waste that usually accompanies filling up. Then, too, the old tobacco which is now on top in the pipe has been dried out by the heat of the former smoke, and lights up easily. The illustration f= ae shows plainly how jee -* snugly the bottom fits on the pipe. This close fit . makes the connec- tion air-tight, so that the efficiency of the pipe is in no smallest degree hindered by its piecemeal con- struction. On.the Trail of the Wolf and the Grizzly-Bear The Sensible Socks of Japan APANESE women made socks for their soldiers in-a way that was far less ' expensive than ours, and much simpler. . a 7 They made them out of paper. Paper, | if you stop to think of it, has a reputa- tion for keeping in the warmth of the body. These Japanese socks were of thick, heavy rice paper, made in a single piece, shaped like a baby’s sock. They were worn for only a few days and then CONOMY, ease, and enjoyment all congregate inthis new pipe 56 Popular: Science Monthly — it has been estimated that each wolf kills about a thousand dol. lars’ worth of cattle a year, eath bear and each lion five hundred dollars’ worth, and each bobeat and each coyote fifty dollars’ worth .... Not only is money saved by _ these killings, but it is also Made; , for the,fur from these anifnals ig very valuable. Last year the in- come from skins was approxi- mately one hundred thousand dol- . lars. Some of these skins are shown here hanging outside of the log cabin of one of the govern-: ment men. The hunter himself is standing in the doorway. HIS great -sea-turtle was taken by fishermen off the southern California coast and towed into San Pedro, the port of Los Angeles. The creature weighed 428 pounds, and fur- nished steaks and soups for hundreds of patrons of a café, It was the largést turtle ever caught north of Mexican waters in the Pacific. Boatmen found it basking on the surface of the - water, and ‘harpooned it. When Bullets Meet in the Air S° many bullets flew through the air in both directions, in large battles of the Great War, that some of them were bound to bump into each other. When a German bullet and an English bullet met, what happened? They fought it out to a finish right there, and fell to the ground interlocked. A pair of fighting bul- lets were ‘picked up by an English soldier one day after he and his comrades had pushed the Germans back several hundred yards. The bullets are shown to the left in the illustration. The English bullet, of course; is the upright one, the German bullet badly bent. The bullets pic- tured on the right show even greater signs of having ‘been through the war. In their perilous journey over No Man’s Land they struck barbed-wire en- tanglements, with the results shown.

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POT RT Bee 1e up vas the ind ort ure ur- for fé. ers ind the rge“ to ish ght ul- nd red on. 1an British official photograph; © Underwood & Underwood If the King Had Stood upon the Bridge This Salt-Refinery Is Its Own Advertisement N those far-off days when Zeppelins flew over England and Ha? Hans and Gretel been salt-lovers, they would have joy- submarines infested the English Channel, King George decided to look things over in France. ous lest harm befall him on his trip, and so they put on the ship that was to take him over several safety devices. The picture above shows one of these devices — padding tied around the bridge to protect it from shell splinters. This was’ certainly the height of precaution, for the German navy that was did not have a reputation for being venturesome, and there was little chance of its attacking anything larger than a __ refineries. motor-boat. ; But if King George had happened to be on the bridge —as he isin the illustration when an attack was made, flying bits éf steel would have embedded themselves in the padding instead of in the King. Use This Table instead of Your Lap HOSE of us who are versed . in the latest developments of Hawaiian habits know that in order to be truly up-to-date you must get a steel guitar; and a steel guitar must be held in a horizontal position when played. This is quite inconvenient, since one’s™lap, the only ho- rizontal resting-place one has, is too far down to serve efficiently. Therefore a thoughtful man has invented a guitar table. The table, which glides on casters, is hinged to the chair in which the player sits. When he wishes to play, the musician swings the table with the guitar on it in front of him. When he gets through playing, he pushes the table back. fully pounced on the house shown here, for it is salted inside His faithful subjects were nerv- and out. It is a refinery near the Great Salt Lake in Utah, and its salty coat is caused by some of the damp salt, on its way in, sticking to the outside and hardening there when dry, -instead of going inside to get refined. When the salt on the shores of the lake is about six inches thick, it is harvested with regular farming machines. Plows dig it up, and the salt farmers load it on wagons, and then send it to When the refineries get through with it, the product emerges as either table, dairy, meat, ice, rock, or pickling salt. Sieves and strainers decide which is which. We must thank Great Salt Lake for keeping down the price of salt. Too bad sugar doesn’t come that way. A Boys’ Dirigible Balloon with Parachute A WESTERN novelty manufacturer offers a toy balloon consisting of a six-and-a-half-foot bag of strong tissue paper, two inflating cartridges, one tissue parachute with a cardboard dummy, two sets of time-fuse, and directions for the use of the toy. To send up the balloon, the bag is first loosened, then the lighted inflater is inserted in the bag. Before burning itself out, the inflater will carry the balloon to a considerable height. The parachute is attached to the balloon by a time-fuse, which will burn when the: inflater -is burned out, thereby releasing the parachute with the dammy. The balloon may be recaptured and sent up again with the extra inflater. Looks Like the Smallest Statue of Liberty HEN the Statue of Liberty came from France to settle down in New York Bay, she was so large that she had to be broken up into 300 pieces, and shipped in several loads. Then, when the last of the 300 pieces had arrived, she was slowly reassem- bled. But in the small copy of her shown above all these complications are eliminated. This one-pieced statue lives, not on an island, but on a white- enameled box in which is con- cealed a-battery. The battery is connected with the lady’s torch, and may be lighted by pressing a button. Since stand, statue, and battery are all in one, moving-day for this small lady is a very simple matter. aa EE spondetinans j-apoir. eter? WIE Cit Re aI PRETEEN OE ~

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The balloon was behaving badly when this picttire was taken at Fort Sill, Oklahoma, and so the bag was deflated. Then, as the other pic- ture shows, something happened N a recent test of marksmanship [ one of the army aircraft schools, two small balloons were provided as targets for two respec- tive groups of marksmen. At the first shot from the first group the target burst into a mass of flame and smoke—the effect of an explo- sive bullet. The second group fired once, twice, a dozen times. Obser- vers were sure that some of the shots had scored hits—but nothing happened. The firing continued, with the- same?’ negative result. Something was wrong. The explo- sive ammunition was pronounced defective. Report to this effect was made formally to the proper authorities. Why It Didn’t Catch Fire Only a few officers present knew the secret. The test was camou- ’ flaged, in the sense that the second balloon could not have been set afire by any known agency. It contained the new non-inflammable gas de- veloped by the government. and guarded as an all-important war secret. This gas—helium—is now being pro- duced in large volume. Its value for peace and war usage is regarded as tremendous. The story of its develop- ment from the inception of the idea to its practical usage has all the elements of romance of the middle ages. It might truthfully have been said to the disappointed army marksmen: The reason you don’t explode that balloon is because a Professor Cady, of the University of Kansas, some ten years ago made a survey of the gas and: oil resources of that region, and published a scientific paper, which happened to be in the files of an old British scientist in London at the time one of the Zeppelins was brought down. “Suppose the gas would not burn?” the professor thought. He recalled having seen the report of an American professor, illustrated with so-called iso-helium lines to outline the region where he thought helium existed. The =“ pai We discover how to substitute helium for hydrogen and thus we revolutionize the dirigible airship Pa By Albert Whiting Fox A company of terror-stricken men fled for their lives when a great hydrogen-filled observation-balloon caught fire at Fort Sill, Oklahoma, during inflation. How did the fire start? An electric spark passed when the folds of the bag were rubbed together. It was the same kind of spark that you obtain when you rub your feet on the carpet and light the gas by touching your knuckle to the burner. When non-infamma- ble Helium is used, instead of hydrogen, there need be no fear of such accidents British scientist knew, of course, that helium was non-inflammable, and light enough to lift a balloon or Zeppelin. He put two and two together in the quiet of his study, and wrote a note to the. British Admiralty. That was the beginning. Fascination of Helium for Scientists The Admiralty turned the note over to the proper scientific branch as a matter of routine. Ideas from out- siders came by the thousands, but this one attracted attention, chiefly be- cause helium had a fascination for the British .scientists. Its characteristic line had long been a feature of the sun’s spectrum. But the gas itself had never been isolated on the earth. It seemed for a time as if helium would never beobtained. Then Ramsay and Rayleigh got hold of the residue of several tons of liquid air that had gone through the Claude plant in Paris, and fractionated it, discovering un- 58 known constituents of the air (argon, xenon, krypton) and—helium. There on the spectroscope was flashed the long-lost helium line! More light was ‘shed on helium when it was found to be a constituent of radium emanation. Radium and helium are elements, Radium. was being transformed into helium! Were the old alchemists right, after all? Professor Satterlee, of the Universi- ty of Toronto, made some investiga- tions that led him to suggest the pos- sibility of helium’s being the product of radioactive transformations under the ground. English and Americans Collaborate The Admiralty took the position that, if there was one chance in a thousand of getting helium in quantities, it was worth taking. Professor Satterlee was requested to consult the American authorities and to investigate Profes- sor Cady’s report. Popular Science Monthly a _-~-“Balloons that Can’t Catch Fire on t da dks Cer de. don |) ree ae

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gon, here the d to tion. onts, into nists ersi- tiga- duct nder rate that, - sand was . was rican ofes- ai March, 1919 - About this time the United States came into the war, and the British sent over experts to collaborate with Colonel Burrill, technical head of our Chemical Warfaredivision. He,inturn, took the matter up with General Squier, then head of Army Aeronautics, Di- rector Manning of the Bureau of Mines, and Admiral Griffin, Chief of the Bureau of Steam Engineering in the Navy. Soon after the matter reached Ad- w’.al Griffin, there appeared in his oiice a Mr. Carter, who had given up civilian work to enter the Navy. It The hydrogen with which balloons are inflated is con. tained in steel bottles un- der high pressure. .tisthus that helium will be bottled companies to liquefy the natural gases in the areas indicated by Professor Cady. Congress was-asked.to appro- priate money for.the ‘production of Here we have the third stage of the terrible balloon conflagration at Fort Sill, Oklahoma, of which the first two stages are illustrated on the preceding page. The picture tells its own story of men driven to flight and overcome. by fatigue. Helium instead of hydrogen, as the inflating gas, would obviate such accidents developed that he probably knew more about the liquefaction of air and gases than almost anyone else in the . country. Itseemed asif fate had pushed the right man at the right moment into Admiral Griffin’s office. The Army and the Navy engaged argon. It would never do to let the, truth leak out in the midst of a war. Professor H. N.._Davis took hold of the Army end, Commander Dyer rep- resented the Navy. Now there are two big plants pro- ducing helium in large quantities and another company about to begin, all located in Texas. Naturabkgas is col- lected and compressed and cooled down in \the same kind of appar- atus that is used to liquefy air. As the cooling process continues everything is liquefied out long before the helium. The regular hydrocarbon series, making up ap- proximately 70 per cent of the natural gas, liquefies first, and then the nitrogen, constituting about 30 per cent, is condensed at a temper- ature of 195° C. below zero. It requires 268 degrees below ordinary ‘zero (Centigrade) to liquefy helium, which is then collected for use in balloons. The amount of helium in natural gas is .95 per cent. Had the Germans Known Helium In a military sense, helium for balloons is the answer to the high- explosive bullet, just-as armor in the old Navy was the answer to the guns that riddled wood. Had the Germans filled their Zeppelins with helium instead of explosive hy- drogen, they might not have proved such failures as city bombers. The entire art of designing and equipping dirigibles will be revolu- tionized. Electrical apparatus, heretofore barred because of the ever-present dread of sparks, may be installed, new types of motors may be used. A new field is opened up for development. Why is there so much helium in Kansas, Oklahoma, and Texas? Prob- ably because of the quantities of radio- \ active minerals. Helium, as we have seen, is a degradation product of radium. fll that is ‘eft of the balloon is the basket. helium, which is almost as light as hydrogen, but which is not infammable. 59 /s ong as hydrogen—highly inflam-rab’e and, when mixed with air, violently explosive—is used to inflate bags, such acc dents are inevitable. ‘¢nd now the government announces that it had made preparations before the armistice was signed to fill the bags of balloons and dirigibles with It sounds like an alchemist’s dream

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Popular Science Monthly And the Transportation Engineer Said: ake ® ‘ite RS. cc PARE t E 5 | | f FaleRs 5: at | 5 EE ES A Ra 8-9 f . r NEW YORK. has street cars, subways, and elevated trains, and still its millions of people find it hard to travel from one part of the city to another without fighting.for a place. to stand up in, much less to sit down. Sooner or later Néw York must come to. moving, sidewalks. It is an old idea, revived, with improvements of his own, by Hjalmar E. Skouger; a construction engineer. Similar apparatus is now used in carrying half finished prod- ucts from one department to another in factories, or in load- ing or unloading steamships and railroad cars. The moving platform for transferring human cargoes consists of short units of steel or wood, formed in an endless chain, and actuated by gearing beneath it. It may~consist of ‘three or four par- MOVING PLATFORM allel sections, the first going at the rate of three miles an hour, the second at six, and a third at a speed of nine miles, or even a fourth proceeding at a still higher rate. Passengérs step from a stationary platform to the first section, and go by scarcely perceptible stages td the fastest strip. When they wish to alight they return to the three-mile gait, which is about that of an ordinary walk. The platforms may or may not have seats for the public, as traffic conditions require. Exits to the street above can be arranged at short intervals; for an underground line could be skirted by an arcade that would be a continuous station. The distance to be covered in Forty-second street, New York city, 3,000 feet, would require approximately 6,000 feet of

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March, 1919 “Let the Sidewalks Move’—-And They Moved

GRAND CENTRAL STATION

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moving platform. The main difficulty in installation would be in making turns at the terminals. Mr. Everhart Smith, inven- tor of the best known type of platform, says that this can be done in a circle with a radius of sixty-five feet, without en- croaching on building lines any more than at present. His estimate is that the device can be kept in motion, even with Many passengers standing on it, with about 200 horse- power. The ten-car subway express trains are driven by motors cap- able of developing 2,000 horsepower, but no such energy is needed because of the heavy losses of electric current due to stopping the trains and'starting again. © This‘ moving: platform would be a continuous, non-stop train. If the platform stalled, the passengers could stepoff or walk along it to their destinations. No conductors are needed, and one engineer does all the work. Inspectors stationed beneath the belts take the place of track-walkers. A few ticket-takers and -choppers would be re- quired. All the engineering and operating points have been worked out for exhibition purposes with success. At the World’s Fair, held in Chicago in 1893, a local com- pany organized by Mr. Smith operated the first moving side- walk, 4,400 feet long, which was ridden on often by 6,000 per- sons at one time. A second was installed*in Berlin in 1896; while at the Paris Exposition in 1900 a third one, four and one half miles in’ length, was patronized daily for months by throngs of sightseers.

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Popular Science Monthly Four Automobiles to the Car A new system of crating solves a problem in freight-car loading HE problem of shipping auto- mobiles has. re- ceived a great deal of thought by those engaged in the in- dustry, and yet there has always been the objection of waste space when the auto- mobile has been finally loaded on a’ freight-car. In loading auto- mobiles on freight- cars, the number is limited both by the dimensions of the car and by the - size of the opening through which the machines are in- serted. With cer- tain sizes of freight- cars, while there may be sufficient spacefor more than two automobiles, the size and posi- tion of the door limits the number to two. To increase the loading possibilities, a new system of crating has been de- vised. The automobile is first jacked ; D 1a , Sas. By a new crating method three large automobiles can be shipped in a thirty-six-foot freight-car and four in the forty-foot type up so as to remove the front and rear wheels on one side, after which the crate is placed alongside and wired securely. Recessed blocks receive the ends of the axles and assist in secur- ing the framing. The next itep to the loading opera- tion is to turn the automobile on its side, with the side frame underneath, Suitable trucks are first placed near. by, so as to move the machine .read- ily-through the door of the car, the other wheels of.the machine having been removed be- forehand. Two machines are placed lengthwise of the car at each end, if thecaristhe forty-foot type, and even in the type three large machines can be ed. To insure safe transportation, the load is securely braced. Shipping automobiles is easy when you know how. It took a long time to learn, however, and much waste space was paid for during the experimental period. Hauling Six Steers in a Truck with Capacity for Only Four Thereby increasing the earning capacity of the vehicle Y placing steers transversely in the truck-body instead of longitudin- ally, the farmer who owns the truck shown below is able to carry six animals in the same body that will hold only four if loaded in the ordinary manner. He thus increases the earning capacity of his vehicle fifty per cent. It will be noticed that the ani- mals are placed alternately, with the heads of the first, third, and fifth on one side, and those of the sec- ond, fourth, and sixth ‘on the other. Thus the entire-body space is util- ized, the steers being wider at the rear than at the head. The animals are kept in their place by locking their heads in rectangular rings pivoted at the top to the body sides and locked in place at the bot- tom. The body sides are removable, and, after the animals’ heads have been removed from the rings, may be _ hooked on the side of the truck-body to provide a convenient unloading runway. By fitting the steers in sideways, the truck will hold two more 62 “ thirty-six-foot . conveniently load-' ne Yr ‘ mail pate fittii dian radi wat -end sma that scre insi insi ligh V per: val’ errr, \

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ve e 1g “March, 1919 How to Keep Your Truck Radiator from Freezing NTI-FREEZING compounds of various combinations success, but it re- mained for W. Bonson, of Altrincham, England, to patent the simple device shown below. It is made by ‘have been tried with partial fitting a tube of about 1l-inch or diameter crosswise inside of the bottom ‘tank of the radiator. The tube is open to the air at both ends, and is made water-tight by brazing into the ends -end of the pipe is threaded and covered with a cap having small holes to admit air to the inside of the tube from that end. At the center of the tube lighting or to the fuel tank. Whenever the truck has to be parked when the tem- perature is below the freezing-point, the fuel or acetylene yalve is simply opened and the inside tube filled with gasoline A tube in the radiator is filled with gasoline and lighted to keep the water from freezing REMOVABLE WINDOWS 14-inch internal of the tank. One at the cap end is a serewed a second smaller pipe which extends along the inside of the first tube for almost its entire length. The inside tube is attached to the acetylene tank used for or acetylene gas, which is_ lighted BOW FRAME with amateh. The 2, OF TOP air required for y fae —SWIVE! i combustion comes from the ends of FELT the open tube, and HA PACKING the heat given off | keeps the water hot. While the | ous device was origin- HH ally planned for 3 war trucks, it can y SASH PIVOT “A be applied with equal success on commercial motors, where a frozen radi- ator is apt to mean cracked cylinders. — = 7 we ESS TUBE-SUPPORT SWIVEL TUBE -SUPPORTS oc eee) y — FRAMES —>| -/ i ws . 4 Detachable side windows have turned this old touring car into a comfortable limousine Detachable Windows for Old Cars— A. Cold-Weather Comfort WING to the curtailment of automobile manufacture, your car may be worth as much as you paid for it and it may pay you to provide it with mod- ern conveniences. E. A. Arm- strong, of Highland Park, IIl., has patented detachable side windows, obviously preferable to the ordinary side curtains. Each window is inclosed in a metal sash. The sashes in ‘the way of the doors are fastened to sracxet the doors, while the others are yaQONCAR fixed in place, although free to weave or move as the top moves because of the car’s vi- bration. First Loaded Truck Trailer Over the Alleghenies HE first loaded motor-truck trailer ever hauled over the Allegheny Mountains early in Decem- ber completed a round trip between Akron, Ohio, and Boston, Mass., a distance one way of 740 miles. Motor-truck haulage over the roads - ’ OPERATORS PEDAL We REAR WHEEL BRAKES FOUR CYLINDER AIR COMPRESSOR between Akron and Boston began early in 1917, and has continued ever since. Several attempts had been made to employ trailers in the work, so that the tonnage carried per trip could be increased to five or eight tons to reduce the cost per ton hauled. AUTOMATIC CONTROL VALVE TRAILER RESERVOIR TANK SOO CUBIC IN. Griceahiewes a * GBS ; 4«@ & tig # ~” TRAILER BRAKES AIR. CYLINDER FOR ONE TRAILER BRAKE FLEXIBLE CONNECTION BRAKE AIR \° CYLINDER. Pneumatic air-brakes on both tractor and trailer insure safety on ; steep grades, making it possible to haui freight over mountain roads 63 However, these had to be given up, because the trailer could not be held in place when descending the long steep grades. The trip was finally made possible by equipping both the tractor and the trailer with a new type of pneu- matic air-brake which permitted the outfit at times to coast down some of the steep grades at a speed of over thirty-five miles an hour, with the trailer in complete control. The brake equipment is the inven- tion of A. L. Parker, of Clevelarfd, Ohio. It consists of a small four- cylinder air-pump driven from the engine; a reservoir tank on the tractor; another reservoir tank on the trailer; a distributor valve; an unloader valve corresponding to a safety valve on a boiler; and. the necessary piping and flexible con- nections between the tractor and the trailer. This flexible connection is carried along the draw-bar, so that it does not interfere with the operation of the outfit when rounding corners. SEINE BIEN INE CE SIE IN LENCE ICT

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Oe a Le ec a err eer IRIS -thoroughly as if a scratch-brush had A mass of highly polished minute steel balls and pins, rolling and tumbling over the silverware, cleans and burnishes ‘it Keep the Silver Shining OUSEKEEPERS with even a moderate collection of silverware find it difficult enough to keep their family silver in presentable condition. In clubs, res- taurants, and hotels the task of keeping the silver clean and well polished presents a serious problem. - Chemical baths for the removal of tarnish, and the frequent use of the scratching-brush and buffing-wheel, together with chalk or some other detergent. for restoring, the polish_. which adds so much to the attractiveness of the service, are effective, but require much time, labor, and expense, and soon wear off. Occasional reburnishing will keep the silver bright, but it requires a great deal of time and is entirely too costly a remedy. In burnishing, the metal surface is rubbed with special tools of highly polished steel. The silver is given what may be called a massage, which hardens the surface and at the same time imparts to it a high polish. The work is mostly done by hand, and requires highly skilled workmen. A machine for burnishing silver, the invention of a - Swiss citizen, is now extensively used in many large hotels, restaurants, and club-rooms. a Popular Science Monthly It Bends Cold Pipes Like Wax 4° BEND a six-inch wrought-iron pipe without the use of heat would have been considered impossible a few years ago. Now, however, with the assistance of one of. the powerful devices shown in the picture below, pipes of a'diameter as large as eight inches can be bent. It took nine and one half minutes to give to the six-inch pipe in the foreground-a right-angle bend. The pipe was bent in the cold state. It would have requireg several hours’ work to perform. the same task by the use of heat. The device consists of a large iron wheel, provided on its periphery with a groove snugly fitting the diame. ter of the pipe. By~means of a powerful toggle-joint lever, operated by four or more men, the pipe is pressed against the grooved curve of the large wheel. The pressure produces a barely noticeable bend at the point of attack; but, as the position of the pipe is shifted and the pressure of the lever applied at: a point a short distance from the initial point of attack, the curvature of the pipe increases rapidly. The work is completed when the ends reach the desired angle. If the curved pressure plates of the bending device are applied judiciously and at short intervals, an almost perfect curve can be produced. In some bending-machineg, hydraulic pressure is used instead of a toggle-joint lever; but experience has shown that the work can be done more quickly and satisfactorily with a lever device operated by man-power.. Bending a wrought-iron pipe without heat—a feat that would have been considered impossible a few years ago. It is accomplished by pressure applied by a large iron wheel It is so simple that even an in- experienced person can operate it successfully. The silverware is placed in a cylinder immersed in a soap solution and containing a quantity of small steel balls'and pins. The cylinder is slowly rotated by a motor or any other suitable source of power. As the cylinder turns, the minute balls and pins, each constituting a small burnishing tool, slide, tumble, ar roll over the silver, removing all tarnish and dirt, and imparting to its. surface that high gloss and finish which only well burnished silver will show. The small balls and ‘pins are of several sizes, and as they roll over the silver they reach every corner and every crevice of the most delicate ornamentation. The surface of the. silverware is cleansed as been used, but there is practically - no abrasion. Ten per cent of the silver is lost every year in using the scratch-brush and buffer. Another exploring Drake. He built his © boat himself, and sails it single-handed 64 The Cook, the Crew, and the Captain Too NGLAND has produced another exploring ‘‘Drake.’’ This one, named Thomas, was living in Seat- tle, Washington, and was fifty-five years old, when the roaming desire seized him. He immediately built a five-ton auxiliary schooner, 32 deep. It carries 750 yards of can- vas and a 5-horsepower engine. When the boat was finished he named it Sir Francis after the Drake of Elizabethan days. He Nancy Bell, for he sailed away all alone, his own captain, crew, and cook. cruised down the coast of California landing when the spirit moved. Then he came up the Atlantic he hopes to travel the. world ‘over. feet long, 10 feet beam, and 8 feet .. might well have named her the — Alone in this small boat, he 4 and through the Panama canal, . coast asfaras Maine. Andinthis way:.:

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int the ted ort » of hen vice Lost nes, ver; Lore ited - tact against the protrud- M arch, 1919 HE pneumatic riveter was a great invention. It expedited steel assembly work. But why do we still heat the rivets on a forge fire? And the heater, why must he toss the heated rivet toa man twenty or thirty feet away from or above him, who must deftly catch it in a bucket? Why must the rivet be handled again, placed in the rivet hole, held in position while the riveter is set to work upon it, the rivet chilling every moment? I want to see the riveter place the rivet in position cold. On his pneumatic machine would be a spring device that would hold two or more carbons in electrical cor- ing rivet. The plunging or hammering function of the riveter machine would not in any way dis- turb the contact, because the spring part is attached to the hand part of the machine or the portion that is not in action. The wire would be attached to the riveter, and the other pole wire to the dolly-bar or some solid “backer” against which the riveting is done. | Riveting? Do It Electrically By F. W. Fitzpatrick Naturally, there are details to study and difficulties to overcome. The cur- rent requisite to heat the rivet to the right point, the resistance, and such matters must be determined. Provision must’ be made for the protection of the opeérators,. for relax- ing the spring so as to remove contact for the last few finishing strokes, and eee Sins ‘ie, Sea “I want to see the riveter place the rivet in position cold. On his pneumatic machine would be a spring device that would hold two : or’more carbons in electrical contact against the protruding rivet” chine. for the best form. of contact, which will have to be car- bon, as far as material is concerned. Electrical driving would keep’ the rivet hot to the very last. The metal would be more malleable and would . fill every unevenness -of the hole. The percentage of poor riveting would be negligible. . The points of contact are so close to each other, and the rivet is of so different a quality from the plates, that the cur- rent would naturally flow directly to the spot where it is wanted. Electrical heating hot, ‘so plastic, that I doubt if a riveter. or hammer will be neces- sary. | Simply heat the rivet to the right temperature and force it into position and shape. A sort of compressive action will be all that it will need. Electric riveting would mean comparatively little cost for current, infinitely greater speed, much better work, and the cutting off of two men to every ma- A Spiked Snow-Plow for Icy Days HE snow-plow of former days was ineffective in severe winters when the extreme cold turned the snow to ice, and an ordinary broom snow-plow would not clear railroad tracks. An ice-cutting snow-plow has been in- vented which plows its way through ice, and may be easily attached in place of the old one. Three malleable-iron brackets are The teeth on the cutter-spindle plow through the ice on the - tracks; this is a feat impossible to.the ordinary broom plow fastened to one end of the under- frame where the plow used to hang. An eighteen-inch cutter-spindle with teeth attached replaces the rotary broom of old. Coiled springs over the bearings resist the upward thrust of this spindle. The cutters on the spindle are of steel, eight inches long and an inch thick. They are hardened at the lower end for about one half their height. These teeth are placed on three split collars on each drum. There are seventy-two teeth in all. The spindle is raised and lowered by means of chains. A jack-shaft mounted in the axle bearings, which is geared to the driving motor on the floor of the cab, drives a counter-shaft, which in turn drives the cutter-spindle. On this new type of snow-plow, a chain raises the spindle from the ground when there is no ice to cut will make “a rivet -so . s ' Hy t CREB ARM a RPT oe ah ae SENS IF

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+ © SENDING |< <—@ - — <PLUAGER. ‘ dl

7 ape jpites ee LEVEL PROTRAC TOR, Popular: Science Monthly Bis RR otter ceases

A saw set having oper- ating handles that are so arranged as to enable . the operator to assume a comfortable position

A device, easily carried in the pocket, which fits inside jaws of an ordinary vise for clamping pipe Things Machinists Ought to Know About Their Tools

This planer combines a level protractor witha * planer, thus producing au- tomatic checking of cor- rect angles while planing

front control, and ease of operation were the fea- tures kept in mind by the designers of this driller The removal of giant locomotive tires is simplified by the use of this ma- chine, which burns vaporized kero- sene and is adaptable to all sizes This parcel-tying machine ties from . twenty-five to thirty packages a minute

Making twenty-eight fineness tests of cement in a little more than an hour, this machine is a great time-saver

A high-speed drilling- machine manufactured upon safety-first principles in order to make possible its operation by women A: new and compact motor drive ,for double-spindle shapers, using standard vertical motors that are independently adjustable to suit the length of belting The appliance is about a foot. square and attaches to any electric light socket

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vw March, 1919 Several Useful pe New Ideas for Housekeepers Theattractive wick- er basket skown Eelcw is so skaped as to envelcp com- pletcly a crowing plant in its pot, producing the ap- pearance of cut flowers in a basket Hot, dry air will taixe water wher- ever it may be found—from furniture, house trimmings, and floors. To keep these from separat- ing and showing large cracks, mois- ture siculd be added to the hot air. This radiator humidifier does the trick A knife-sharp- ener in the form of a reel strap whick pulls down when in use This duster-mop has fingers that reach un- der radiators or other places difficult to get at | { i | { ' : 4 lL A metal chair with a box placed on the lower rungs holding working tools; it may be used in stores, fac- tories, or even the kitchen At the left and cbove is shown a combination device for use in various ways in the kitchen Heat for the gas oven or grate may be regulated for any length of time by the de- vice shown at the end of the stove in the picture above BAND- TIGHTENING) | WIRES OO LE PERG P age ctcomaasie A faucet receptacle for soap. It swings aside when not in use When the condensed milk can is inserted in this retainer, the spout pulled up punctures the can, making it ready for instant use ~ 67 A handle for lifting preserve jars. out of boiling water

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You Can Read Her Service Record on Her Stack VER since steam first went to sea and smokestacks began to rear their heads in the proud company of masts, sailormen have used thefunnels of their ships as bulletin-boards to record rank and class. The skipper of a rusty tramp, sighting one of the aristocrats of the sea, could say, once his glasses had picked up the mark on her funnels, ‘‘There goes a Cunarder,”’ or ““Yonder’s one of the new White Star boats’; while, like as not, even the stack of the tramp freighter bore some emblem to tell the world afloat whence she hailed. Tramp or liner, noship ever floated that was not loved by someone, and this affection for peace-time craft is intensified in the case of fighting-ships. The mere landsman may look upon a ship as just so much inanimate iron, wood, or steel; but to the sailor she is as much alive as. any other lady. He may stand for a slight on his own ap- pearance or performance, but, as you love peace, don’t try to belittle his beloved craft. The latest thing is service stripes for ships. The Cas- sin, having spent a year in foreign waters, sports two gold service chevrons on her stack, just as her crew —from chief officer down to the least deck-scrubber— wear the same sign. © International Film

“Wesrere Kee exe

© Kadel & Herbert (Above) Sifting the sand at Coney Island for jewels (Below) Showing results of one day's beach mining

Treasure in Coney’s Sands OREIGNERS coming to America expect to find the streets paved with gold. So we pacify them by offering the golden sands of Coney Island. For each year, when the cold winds send the bathers home, the sands are full of things they have lost. An enterprising native who owned an ash-sifter de- cided to try his

re - [tae ee So

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The “old girl” has done her bit, so it’s fitting she should display the service emblem on her stack luck. He started *| one morning and “| panned all day, ‘| filling his sifter with sand and then washing it in the waves. When the day ‘was over he had collected in his sifter fourteen dollars worth of money and jewels.

Frought to a state of collapse by earthquakes and bell vibrations, the top of this tower had to be cut off Bell Vibrations Helped Wreck a Tower STRIKING illustration of the destructive power of vibrations is given by the events which led to the removal of the tower of the Log Angeles City Hall recently. The City Hall was built in 1888, and had atower 183 feet high and 26 feet square. For many years a large fire bell hung in the top part of the tower, and the vibrations caused by the frequent ringing of the bell wrought havoc with the masonry and would un- doubtedly have led to its collapse, After a heavy rain-storm the tower listed heavily and pieces of the coping - and the stonework crashed to the pavement. An investigation dis- closed its condition as unsafe. The vibrations of a big bell are far- reaching. When the clapper strikes the bell the vibrations cause the sur- rounding objects to vibrate in sym- pathy. Wood is very elastic and is not materially affected, but masonry possesses practically no resiliency, If there is any weak spot in the ma- sonry, the work of destruc- tion will be hastened by it. That is what happened to the bell tower of the Los Angeles City Hall. The earthquakes in the past thirty years had caused cracks in the masonry, and the bell vibrations has- tened disintezration.

i haa a ie a Popular Science Monthly 7

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- “ @ ¢t = 1 Retact OD AO se a eer March, 1919 LESS the mystery of the United States collier Cyclops is solved at the peace table by a forced accounting of shipping losses on the part of the Germans, or unless some survivor unexpectedly turns up at this late date, the loss of the vessel, which has puzzled mari- time experts the world over, is likely to go down - as one of the most unusual in the annals of ocean shipping. It will be re- membered that the vessel, one of the most modern of coal-carriers in the United States Navy, left Rio de Janeiro, Brazil, early in January, 1918, with a cargo of valuable manganese ore for Europe, and has not been heard from to this day. The Navy Department has placed the Cyclops on the missing list as one of those that have passed to the Port of Missing Ships, never to return. The strangest part of the mystery is that, while the vesseh was equipped with a most powerful wireless outfit, not a word was ever picked up from her. There have been rumors that she’ was captured by a German submarine, and others that she was delivered over to some German vessel through the treachery of a German agent on board Vy Vyw yy | BRBBBBBBBBBBBS BD SENDING. MOMEy>. “yOXNNCY CURVE : _ a, rss OF VESSEL M By Joseph Brinker or blown up by a bomb placed in her cargo while it was being loaded. If her loss can be laid. to none of these causes, she must have gone down The U. S. collier Cyclops, a giant of her kind, sailed for the Port of Missing Ships over a year ago. From the day she left Brazil, bound for Europe with a cargo of manganese ore, nothing has been heard of her, although she carried a powerful wireless equipment. No report has come of her sinking or capture. How is it possible for a ship to disappear, leaving no trace behind her ? or water. and foundered. How Ships Break in Two The two upper sketches show, first, how the weight (W) of the vessel in still water acting downward is balanced by her buoyancy (B) act- ing upward; and, second, an exaggerated view of the ship supported on the crests of six waves with the weight acting downward at those points to pro- vide equilibrium. The next two sketches. show, first, what may happen when the steel of a ship’s hull is not sufficiently strong to stand the strain when the vessel is supported on the crest by a wave, and unsupported at either end; and, second, what happens some- times when the ship is supported by the water at either end, but not in the middle, a wave having “run out from under her.” It is quite possible that this was the fate of the Cyclops, owing to her heavy loading amidships. The bottom sketch is of typical. assumed curves of the Cyclops, suggest- ing a way in which the heavy loading amidships might have caused her to break in two 69 with all hands on board by some accident due to the elements of wind There is a possibility that the Cyclops ran into a severe storm Provided her hull did not spring a leak and admit water faster than the and broken middle. simply was How Ships Capsize The upper picture shows trans- verse buoyancy with the weight of the vessel acting down through the center of gravity (G) and the buoyancy (B) acting upward through the same center. In the second picture the vessel is shown rolling. The center of buoyancy moves to B!, and a vertical drawn through: B! intersects the center line of the vessel prolonged at the point M. The distance GM is called metacentric height. _ The aweight- acting down through G and the buoyancy up through B? forms what engineers calla turn- ing moment, WxGZ, tending to right the vessel. But when, as illustrated in the lowest figure, the vessel has turned on its side, so that the point M is below the point G, the weight W acts downward on the side most im- mersed, while the buoyancy acts upward through B, forming a force that will turn the vessel completely over. This is what may have happened to the collier Cyclops if her cargo shifted What Happened to the “Cyclops”? If not sunk by the Germans, what might have happened to her if she was caught in a storm pumps could get rid of it, she might have sunk in either one of two ways— by breaking apart amidships, or by capsizing due to a sudden shifting of her cargo. If she broke apart amid- ships, the manner of her going is best. illustrated by the accompanying sketches. These can best be under- stood by remembering that aship floating instill wateris held in equilibrium by two sets of forces, the weight of the vessel acting down- ward and the buoyancy: of the water acting upward against the hull. If she broke apart, it was either when she was balanced midway on the crest of a huge wave or supported only at her ends on a wave of her own length. In the first in- stance, she would be in the same position as a stick held across the back of a chair and broken, by a person pressing downward at each end. If she broke apart when supported be- tween the crests of a wave of her own length, it would correspond to a stick placed between two tables by a weight placed at the If she sank by capsizing, she forced over on her side so far that she became topheavy and turned upside down. APRS P FO RLEIGUID LTE ERE = \ \ SCE PPE ERY Te BRIEF LEE IO a

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mt SE ee | Popular Science M onthly nuity Has Played a J fa ox e : * eR aera peo eae) You put the ash-sifter upon your can; then you move the handle back and fort and vibrate the screen. No dust is scattered, because everything is inclosed \VITY SIFTING SCREENS enna 7 Mere a a Dump the ashes into the hopper. They fall upon the first inclined screen. ‘The heavy unsifted particles pass to the next screen. What coal is left is taken out by way of the door which is shown open You don’t have to shake anything in. the apparatus shown at the left. The ashes trickle down on the cone - shaped screen, and this in tum spreads them To shake the screen a crank-shaft and two rock-shafts are depended upon.. Turn the crank-shaft and the screen -moves ~back and forth. - The ashes fall into a receptacle .and pass out. through a gate into a can You shake the screen” _much as if it were a corn-popper, and then so that the ashes | dropintothe’can. The chief merit of the ar- rangement is that the dust is not scattered Here we have the rocking-chair -prin- ciple. Johnnie de, simply. rocks ‘the - apparatus back and forth, the ashes drop down into a receptacle at the bottom, and the unburned coal can be withdrawn by opening a_ gate

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March, 1919 > Fairy Godmother to Modern Cinderellas TIRRER ESTATIONARY. REEN-CONE .@ 89g Another dustless ash-sifter. Here we have a stirrer used inside of a stationary screen. Turn the crank-handle at the top and the stirrer forces the ashes through the screen. The whole appara- tus is placed on an ordinary ash-can * w ‘PERMANENT SIFTER: ' oni + \ UNDER THE GRATE To clean the ash-pit, slide in two metal standards and two cross-bars to form a platform for the wire mesh. Then slide the two halves of the sifter into place. As you shake the furnace, everything is caught by the sifter. The ashes fall through to the floor; the fuel is left on the sifter to be used over again This is a wire screen shovel. The ashes are scraped up by means of a combined gate and. scraper. During the shaking process the scraper becomes a gate, which opens and discharges the coal Connected with the rotary screen is a fan whick blows the ashes into the furnace so that they pass out by way of the natural (draft This ash-sifter, built into the stove, shakes. the grate. The ashes drop down into a rotary This saves the trouble of carrying the ashes out of the cellar. A screw con- screen, which is rotated in such veyor leads up from the ash-sifter. Turn the crank, and you not only sift a way as to shake out the ashes the ashes, but you convey them out of the cellar at the same time : “71

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Popular Science M. onthly Paper — Made, Used, and Scrapped in a Day NEG IE ORG EE BNE ES ees : As soon as:a letter arrives, the envelope becomes waste paper. All the mail deliv- ered in a day will fill count- less waste-paper baskets like these with envelopes 4 P, Sti Leviathan Great ‘ Grand Falls, Labrador Pyramid Niagara #: , bat & “4 sh, OCA I LOOP, A large piece of paper, four miles square (the area of the daily newspapers of New York City), might come in handy for wrapping up a parcel. What could we put 72 Here is a ship laying -a cable con- sisting of a long band of paper one foot eleven inches wide, of which mewpapers pages are made. The ship is traveling 11,000 mites a day to keep pace with the printing- presces as they turn out newspapers for one day in l“ew York city alone. When the twenty-four hours are done, the ship will have made two trips from New York to Liverpool, and will be well on the way home for the second time! Such is the ephemeral nature of a newspaper that twenty-four hours after it has been issued the greater part of it has become a “scrap of paper” Eiffel Tower ros GREE EOE GA sis ie CIEE cs: in it? This picture shows some of the things we could wrap up in the bundle, whose side is about 3,400 feet long. But the parcel is not nearly full, as you see o’el wal mol wel its ent of the guit con of 1 ber fro1 the belt posi

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| March, 1919 Finding Your Way in the March Skies Some constellations are visible at all times of the year, but others come and go with the changing seasons By Ernest A. Hodgson, of the Dominion Astronomical Observatory HE coming of the spring flowers seems hours upon a photographic plate, we find in number in the Milky Way is because of T to be a signal for the gradual with- the number of stars recorded very much the arrangement of the universe. Since drawal of the brighter star fields from the _ greater. we see the Milky Way almost equally evening skies. March is the last month Each of these stars is a sun, shining with dense. throughout its entire circuit, we in which Orion may be seen, Gemini is its own light, just as our sun does. The must conclude that we are not far from the fast disappearing, and in their stead we reason the stars appear so much greater center of the universe in the direction of its have to be content with the fainter con- greatest spread. stellations of summer-time. THE STAR MAP FOR MARCH How pleased the early astronomers would There are some constellations, however, ‘ have been if they had thought of this, for which we have always in view—those of ‘ they were eager to accept any. indication the northern heavens. If the Big Dip- of the importance of the position oecu- per is not concealed by clouds, it will pied by the earth and its inhabitants enable the observer to locate not in the great universe of the heaven- ‘only the pole-star, but also ly bodies. To them, the thought Castor and Pollux in Gemini; that we and our Sun occupied Regulus in Leo; Capella a central position would in Auriga; Arcturus in have brought immense Bodtes; and the con- satisfaction. They held, stellation of Cassiopeia. indeed, that it was If now we trace a line heretical to deny the from Capella through central position to our thepole-star, and con- earth, since the word- tinue the arc a little ing of the story of farther than from creation seemed to Capella to Polaris, indicate that the we come to the Sun and Moon and clear white star Ve- stars were created: ga, in the constella- to move about the tion Leo. This star earth in their daily is not shown on the course through the circular map, but sky. can be seen ris- To the beginner it ing in the north- is a matter of some eastern sky about ten importance to learn o'clock at night to- the correct pronun- ‘ward the end of the ciation’ of the con- month. It would be stellation and star well to become used to names. It would be well its appearance in differ- to note that Rigel is pro- ent positions, for it is one nounced Ree-gel, and that of the interesting stars of Procyon in Canis Minor is the summer sky and helps to pronounced Pro-see-on. Of the guide one among the fainter constellations. ‘the following are constellations. worthy of being noted: Argo Navis Having located Gemini by means is Argo Nay-vis; Coma Berenices is of Ursa Major, it is well to remem- Comb-a Beren-ice-ces; and Lepus is ber that the twins, as they face away Leap-us. Since many of the star from) the Great Bear, look‘ toward Thi names are - Latin, it is a safe rule to their guardian, Orion. Having lo-. — et ye me of the = = = follow the Latin methods of pro- cated the latter, the line through his jyuca,ieted below. It is, specifically arranged for the unciation when in doubt a to star belt, carried northward, indicates the. degrees on either side of this latitude. names. . NOZINOH JSVy position of, first, Aldebaran, and then eB Coma Berenices is just coming into the Pleiades. Carried southward, it February m4 oe us _— as a P.M. view. It is one of the most beautiful brings us to the brightest star visi- - “ 17, 11. an eae 15 7:30 “ of all the constellations, being com- ble in northern latitudes—Sirius, the “ 95’ 10:30 “« 93° 7 “ posed of strands and groups of great Dog-Star. The bright star next in March $. 10 “ May 1, *6:30 “ numbers of faint stars. . The beauty line, if we trace from Polaris through si u ae - 9, 6 ” is greatly increased if an opera glass Gemini, is Procyon of Canis Minor, . 21, 9 * is available. Bernice was a.queen the Little Dog. The magnitudes are indicated on the map by stars of to one of the Ptolemies, King of With the coming of summer the various kinds as follows: 0, open center; 1, eight points; Egypt. Her husband was very suc- Milky Way also disappearsfrom view 2, six points; 3, five points; 4, four points; 5 is indicated cessful in one of his wars, and as a intheevening. It wouldalmost seem y @ single point. Eastern Standard Time. thank-offering Bernice sacrifi¢ed her that the beauties of the earth in sum- beautiful hair to the gods. It was mer, and of the sky in winter, were laid away in the shrine, but shortly mutually compensating us each for ee eee —s The PoPULAR SCIENCE MONTHLY is publish- ve ing Cacorenes we telescope the Milky Way i oeekaan ing every month an article like this by Mr. disdes that Jan, had taken her gift: ‘into countless numbers of faint Hodgson. If you feel that these articles and given it a special place of honor stars; can be made more helpful, write to the editor. , ; i ‘ As proof of this they pointed out her If we call photography to our And if there are. questions that you would beautiful hair.shining, in honor, in aid, and allow the star images to be like to ask about stars, send them along. the skies above. And there it re- focused. by the telescope for long mains, as beautiful as it was then.

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- How to Find the March Planets "PRE planet map this month has been put into.a different form. It will be found much simpler to use, The positions of the planets; the Sun, and the Moon are plotted directly on the map itself, and their positions~are indicated on the open scale of the chart lines outside the map. A few minutes spent in cutting out the little disk of cardboard will enable the reader to answer for himself all questions with regard to the appearance of the sky at any time during the As the equinoxes move, so also does the celestial pole, the latter tracing out a circle in the sky with a radius of 23° 27’. The pole of the heavens will make the circuit also in the 25,800 years. So future gene- rations will not have the same pole-star. About 12,000 years hence the pole-star will be Vega, the- bright star in Leo. (See the description of the stars for loca- ting this star.) watch. It is always preceded by the stationary point, as of course the Planet must, for a moment at least, appear to stand still if it is moving eastward ang then starts to move westward. Fig. 1 illustrates the case of Jupiter The explanation for Mercury is similar except that its orbit lies within that of the earth. The diagram is much dis- torted, since it is, of course, impossible on the same scale to represent month, as-well as the time of rising and setting of any celestial body... Specially Interesting This Month The’ movements of the planets and the Sun are this month especially in- teresting. The Sun is in the constellation of Pisces, the “fishes,” with the ex- ception of the few days at the first of the month, when it is in the constella- tioh Aquarius, the ‘‘water- carrier.” On March 21 the Sun crosses the celestial equa- tor. -Since that line in the sky passes through the exact east-and-west points the orbits of the earth and Jupiter and the pog tions of the distant stars, The positions of the earth and Jupiter for the same date are joined by a line showing the direction along which an observer on the earth would look to gee Jupiter. How Jupiter Progresses As the earth moves about in its orbit nearest tO Jupi- ter it moves so fast that the latter is left behind and appears to move back- ward among the stars. As the earth nears the point where it passes to the side of its orbit opposite to Jupiter, it, for a time travels along the line of sight as it were, and Jupiter for persons anywhere in the world, the Sun on that date will rise exactly in the east and will set exactly in the west. It will bein the sky precisely twelve hours, giving equal day and night over the whole earth. This point in the sky where the ecliptic crosses the equator as the Sun comes above the latter is called the Vernal Equinox, i.e., the position in the spring which gives equal day and night. It is often referred to as the “First of Aries.” or the beginning, from which the Right Ascension hours (see the Roman numerals at edge of the planet map) are counted. In measuring longitude on the earth, a starting-point had to be chosen: Green- wich was the choice. In measuring Rirht Ascen- sion ia:the sky, a start- ing-point had to be chosen: the Vernal Equinox was the choice. When first chosen this point layin the constellation Aries. Hence the term “First of Aries.” .Tweloe Thousand Years from Now After the lapse of cen- turies this point was found to have been moving. Ob- servations have determined that it is moving westward in the sky at a rate that Sie will cause it to complete . "= , It is the first, | ‘The planet map is presented on page 75, with directions about -usingit.as.illustrated here A very interesting theory in regard to the pyramids of Egypt is that certain tunnels built into them were made to point exactly to that part of the heavens which was the pole of the sky at that time. Assuming that the tubes were so built, and knowing the rate of precession of the equinoxes, a measure is obtained for the antiquity of the great stone piles of Egypt. Will they still be standing when, at the end of 25,800 years, the pole has again come round to the place it occupied when they were built? Mercury is to the east of the Sun *throughout the month. It is farthest east about March 28. It is then “stationary.” That is, for a day or two it appar- ently stands still among the stars. Thereafter it appears to move west in the sky instead of east. Retrogression of the Planets It will be remembered that in January and Feb- ruary Jupiter, Saturn, and Neptune were apparently moving westward. It will be noted this month that Jupiter is moving eastward . : again. It was “stationary” the circuit of the heavens APPARENT PATH about the first of the month in 25,800 years. This ee as of’ March—March 2, to movement is known as the “Precession of the Equi- noxes.”’ As the earth moves nearest to Jupiter the latter ap- pears to move backward be exact. This ‘‘retrograd- ing’ of the planets is an interesting phenomenon to 74 is ‘‘stationary.’’ Then, reaching the far side of its orbit, it tends to make the apparent motion of Jupiter faster and faster in the true eastward ‘direction-again. “ is We see a somewhat similar phenomenon | - when we watch an automobile running be- side a street-car on which we are riding. The automobile seems sometimes to move forward and sometimes backward, depend- ing on therelative motion of the two moving bodies. Ideas of the Early Astronomers Early astronomers were hard put to it to explain the retrograde movements of the planets. They insisted that the earth was stationary and the center of the celestial bodies. To explain the retrograd- ing, they supposed that the planets moved in circles about points’ on a great crystal sphere, which also itself rotated about among the stars, the earth being at the center of all. As soon as it was admitted that the earth moved, and that the Sun was at the center, the cumberseme “‘cycles” and “epicycles” of the astro mers were dis- carded. Mercury, Venus, and Mars are all to the east of the Sun throughout the month, and so set after it; they are evening stars. It must be remembered that: they are not stars, as they do not shine with their own light. (Note the extremely variable rate of Mercury during the month.) All are near the Sun. + The two former are always near the Sun, as pointed out in a diagram last month. Saturn continues to retrograde a little to the west of Regulus. Uranus and Nep- tune —the telescopic planets—are but bei Popular Science Monthly sigh last in a1 eartl fails beco may lines in Pp aa. nak im. is et eh ee eG OD

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’ the lanet ar to | and ~ Piter, milar that le on ‘esent earth Stars, earth same 1 line along n the D see SSCS about Jupi- that ehind back- point 2 side fe to time, ne of ipiter ‘hen, of its e the ipiter ‘ward : eae enon | g be- move oend- oving to it ts of arth the zrad- oved bout ; the that as at » the and = not te of near mth. little but oe and Moon. Clearly, this is between the 2d _Moon or any star) rises or sets or reaches ~ the meridian on any given date, turn required date on the chart line of the Sun. ‘to the Sun. Uranus and Neptune are ‘too faint to be seen with the naked eye, March, 1919 ightly displaced from their positions of last month. The latter is still retrograding. During the month the Moon succeeds jn avoiding the Sun at new Moon and the earth’s: “shadow” at full Moon. It thus fails to eclipse the Sun in the first case or pecome eclipsed in thesecond. New Moon may be readily picked out on the chart lines. It is on the date that corresponds in position on the chart lines cf the Sun and the 3d. The exact time is 6h, 11m. A.M., E.S.T. on March 2. Full Moon _the time of coincidence cf the Moon and the earth’s “shadow’’—occurs at 10h. 4m. A.M., E.S.T. on March 16, first quarter and last quarter respec- tively at 10h. 14m. P.M., E.S.T. on the 8th, and 3h. 34m. P.M., E.S.T. on March 24. There is another new Moon on March 31 at 4h. 5m. P.M., E.S.T. Conjunctions of P!anets and Moon The relative motions of the planets and the Moon cause the following “éonjunctions” or near positions of the planets and the Moon: Venus on March 3; Jupiter on the 9th; and Saturn on the 13th. Venus will appear along with a thin crescent Moon in the evening sky on the date given. At conjunction with Jupiter it will be about first quarter, ~ and, if the night is clear, will make a strik- ingly beautiful showing above Orion. It will be coming nearer full at the conjunction with Saturn, and will make a fine group, with the bright star Regulus a little to the east. How to Use the Planet Map The planet map shows a belt com- pletely about the sky, 30° wide on each side of the celestial equator. To use the map, cut out the circular disk on this page and mount on a thin eardboard disk of the same size. Then run a glass-headed push-pin through the center of both the disk and the map. It-is:-now ready for use. Once made, it will serve from month to month. To see the section of sky visible at any time on any date, turn the disk until. the required hour (on the disk) is opposite the required date (on the chart line of the Sun). To see when a planet (or the Sun or sz To use the map, cut out the circular disk below and mount it on a thin cardboard disk of the same size. Then run a glass-headed push-pin through the center of both the disk and the map above. Once made, it will serve from month to month AY) | __—— PE (2) 4 N a | “Tse ta) > an the disk until the position of the body, | A on the map itself for the required date, is on the eastern or western horizons, or NN in the center of the ‘cut-out section as the case may be. The hour is to be read off on the edge of the disk, opposite the -: Mercury lies so close to the Sun as ‘to be scarcely ever seen. Venus, Mars, Jupiter, and Saturn can be seen as bright stars when properly placed with respect } “ | VY \ i i on \ : Salil aii - | a Wa Ml Wit but are visible in a small telescope. i wi | | The Moon positions are indicated by Ma | | circles, the inked-in portion showing the illuminated part. The planets are in- i | il dicated by the following signs: | | Mat MERCURY © SATURN b “ wo VENUS OQ URANUS O | Riss ae | MARS “NEPTUNE ty = = = ce . . JUPITER % ~~ SUN OAND MOON € 5 5 ; i ; R g ; BP ICO:

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aes po one nm a By manipulating a lever, the man in the lft of the picture operates the ladle, which contains fifty tons of steel Handling Hot Liquid Steel NE of the most difficult problems in large steel-mills is the handling of the intensely hot liquid steel, after it is made in the steel-furnaces. Contact with it means instant death, and there is also danger of fire from the metal. After it is ready to be tapped from the furnace in which it is melted and purified, the metal is allowed to flow into a large pot or ladle. The illustration shows one of these sus- pended from a traveling electric crane. The ladle holds about fifty tons of liquid steel. After it has reached the ladle, it must be transferred to molds. To do this the hot metal is allowed to flow from a hole in the bottom of the ladle, and this hole is opened and closed by a lever. This lever is a special mechanism attached to the outside of the ladle, which raises and lowers a long stopper, or plug, inside the ladle and attached to the arms of the lever reaching over the top of the ladle’s side. HE modern incandescent electric lamp is the most wasteful as well as the most economical light-producing invention that man has invented. It is wasteful because, of all the energy in the coal burnt under a boiler to produce steam, which in turn drives an engine and a dyna- mo, 98 per cent is wasted; only 2 per cent reaches us in the form of light. And yet, this wasteful electric lamp is far more economi- eal than a candle or any other device that burns fuel directly to . produce light. The ideal light-producer, so far as efficiency is concerned, is nature’s firefly. Fully 98 per itself in visible radiation. 76 cent of the energy that the creature puts forth to produce light manifests more, the firefly’s light is cold. The illuminating engineer’s ideal—he turns 98 per cent of his light-producing energy into light Populgr Science Monthly His Magic Door to Success Eero psychological and Physiologica} tests have been worked out for the purpose of determining the special: fitness of applicants for em- ployment, but many employers have evolved simple tests of their own. A strange method is used by an employer who is said to have interviewed more men and womey ‘seeking positions of reponsibility than any other man in the world. Applicants are directed to leave this © man’s office by a certain door. It is really two doors since, on opening the one that swings inward, the man is confronted by a second door opening outward. Everybody who passes through that door does one of two things—he looks surprised and starts back, or else he simply opens the outer door and goes on his way. Which applicant does this employer choose, the man who is surprised or the one who shows enough self-possession to counteract the surprise? Prob. ably you’ve guessed wrong; for the man of the door test picks as employees those who show the most surprise. He believes that the man who passes the second door without being surprised into special notice of it may also pass, without notice, matters out of the ordinary routin~ in business and go be unfitted to cope with the unusual. Those who start back in surprise when confronted by the second door are sure of getting the position they seek How Nature Solves the Cold Light Problem The best of nature’s light-producers is to be found along the coast of Cuba. It is a gient beetle with two brilliant phosphorescent spots that make it look as if it had head- lights. So bright is the light which these spots give out that the natives actually use, the beetles instead of lamps. A _ hundred beetles in a glass jar give a soft, cold glow by which it is possible even to read. a newspaper. Why didn’t nature go a little further? - If there were a thousand- candlepower beetle, we would cap- ture him and hang him over our front door. What is Gen bein of t suge dier: not moc gral hide a bi sh ch aceare en

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ers | of [wo hat ad- ich the tles red oft, ible nd- ap- our March, 1919 Don’t Hide Your Adam’s Apple» a bushel. is little work to be done by Although not generally known, it is a ‘sign of brains and courage By John Walker Harrington Adam’s apple, was much talked about not long ago becatse General Pershing referred to it as peing a prominent feature of the neck of the American fighting man. He suggested that the collars of the sol- diers’ uniforms be kept high, and not loose or flowing like the English model, evidently taking it for granted that men would rather hide their Adam’s apples under T ace fruit of the family tree, the Go to Haeckel Some of us have been un- usally marked by the re'‘ic of | Eden; but let us look our scoffers and critics squarely in the eye and tell them to go to Haeckel. That noted biologist and others of his class have traced the descent of man in a way which shows that we came from small beginnings, and kept get- tiag wiser with the ages. Scientists are inclined to accept the theory that man came by long descent from ill-formed, spineless things that came to life by chemical action, prob- ably in some tepid mineral spring, and foind their way to the ocean. Then came.the fish, which, as soon as they got backbones, began to develop some- thiig-like Adam’s apples. A man withoxt an Adam’s app'e would be a poor fish.’ From the primitive forms of thé ancient seas are believed to have comé the mammals, from which sprang Lincoln helped -to prove that an Adam's apple indicates brains the human race. It is a long story. . If you should happen to be in the American Museum of Natural History. some Sunday, take a look at the restorations of the prehistoric forebears of our race by McGregor, and note how the Adam’s apple is almost ab- sent in the earlier forms and becomes larger as the scale of intelligence as- This ancient European, whose intelligence was not great, has a very small apple cends. The ancient Greeks de- picted their strong heroes and their highest types of manly beauty with the wedge-like mark in the neck. Great Men Who Had Them Modern artists, sculptors, and pho- tographers are inclined to flatter their sitters by leaving out the Adam’s apple; and as for many centuries the high stock was in vogue, its presence was much obscured. It is marked, however, in such men es Franklin and Voltaire. The Adam’s apple of Lincoln was so big that even as faithf.l photog- raphers as Hesler and Brady toned it down somewhat on the negatives. The life-mask of Volk and the con- scientious studies of George Grey Barnard all show the long, lean neck and the wide-angled wedge of the thyroid cartilage. : ‘Take, then, the Adam’s apple as a a badge of brains and courage. Primitive China Still Hauls Junks by Man Power HINA, land of glowing lanterns and dainty silk-clad maids, has, alas, its dark corners, too. primitive mode of living is responsible for conditions that shold make “prevention of cruelty” societies drop our children and fly to China. On large rivers like the Her simple, _ brute strength. shore and attached to the junk, which they haul by sheer These trackers, as they are called, lean forward, touching the ground with one hand, and holding on to the harness with the other. They dig their toes in tke soft dirt and Yang-tze-Kiang, sailboats, called junks, are still vsed as cargo-carriers. When the wind is favorable there the dirty, half naked crew, who continually cry to the gods: “Plenty wind, no work; no wind, plenty work!” When the boat reaches the Tsin-Tan rapids, the gods fail them. No pro- Pitious wind alone will carry the frail boats over. Men, women, and children are put in harness on the Cnly the first few of a long line of coolies who are hauling a junk up a river against the rapids 77 pull with all their might, working: their way along inch by inch, and emitting long drawn-out wails. Meanwhile a _ tracking master runs up and down, shouting and beating the trackers into further effort. So strong are the rapids that sometimes three hun- dred trackers are used. The illustration shows the leaders of a crew fighting their way along the shcre. The junk they are hauling is a long distance behind them. why ls: ee Rew, ET oS

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_ yards and three quarters. The hour -hand marks the yards and the minute- hand the inches NOTCHED LOCKING ARM \ In up-to-date shops the sales-girl measures the goods not by guess-work but by a little machine No More “Long. Yards” OWADAYS, when everything costs so much, no mer- chant can afford to have his profits eaten into by long If the gas-jet is locked, the gas can’t be accidentally turned on Lock Your Gas-Jet ERIOUS accidents, involving the loss of human life, are often caused by the unintentional opening yards. Neither does the customer care to receive thirty-five valves on gas-stoves. Of course, the safest way to prevent inches of clothfora yard. But just aslong as people measure such accidents is to shut off the main valve of the supply- over tacks, the chances are that yards will not be yards. pipe, but that precaution is seldom taken. A little device has made its appearance which measures cloth or-ribbon accu- rately, and computes the price to be paid for the article, whether it is an eighth of a yard or ten We Send a ‘Man to Europe EBUILDING war-wrecked Europe is a big job. Man- power alone can’t do it. The best engineering skill, inventive genius, and machines—machines and still more machines—must be the answer. ; There will be thrilling stories to tell of engineering and =e. <p ad augedllapews inventive triumphs, and the camera will be the best reporter. at aed wade The POPULAR SCIENCE MONTHLY is already in the field. George F. y : Paul, who has set up his camera in every corner of Europe and ° , Mexico, ison the sea as this is being written, bound for France, — ee es to begin making pictures for us. His camera will catch the most a. dial Ss Recital dramatic moments in the work of reconstructing Europe. yards are shown in eighths. Inch divisions are indicated by small red figures. This little machine has a dial similar to a watch yards are shown in large An invention by John E. Cadigan, of New York, dimin- ishes the danger incurred by leaving the main supply-pipeopen..A strip. of metal, properly curved and provided with flang- es, is attached to the feed- “pipe of the gas-stove by means of ring - shaped clamps which are bolted around the feed-pipe. Short, curved metal plates fit between the flanges of the strip, so that they canbe slid along forward or back in the direction of the strip. The number of these plates corre-

pee mu: WTOC TON 2 Pompei eo e790 we aick In order to operate it, the piece of goods to be measured is slipped through a groove, and as it is drawn through the machine the dial indicates the amount of material which is passing through the device. The calculation is made in a very simple manner. Prices per yard are in red and the computations in black. When the measurement has been made the amount of the sale is found on a cylinder directly opposite the price. Three little buttons govern the apparatus: one for starting the meas- urement; one for notching the edge of the fabric; and one for resetting the hands and chart to zero. The com- putation chart moves automatically as the goods passes through the machine.

sponds with the number of service valves in the feed-pipe. Each plate bears two lugs, between which is pivoted a notched arm, which may be turned up in a vertical position or swung down to a horizontal position, so as to engage the handle of the cor- responding feed-valve in one of the notches of the pivoted arm. Retain- ing springs hold the arms securely in position when they are swung down horizontally to lock‘the valve- keys. ‘ : Each arm has three notches which fit over the valve handles. By sliding the plates to which these notched arms are pivoted between the flanges holding them, the arms may be ad- justed to lock the valves in any desired position.

ren anc hea the big fra tw lov

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Allied armies the ‘‘caterpillar”’ has been put back in condition tofu ~~ pillar” tractor, which “i supplied the power j for the other imple- n ments. ; wer The land-leveler is j remarkable for its size fe and ruggedness. A iS heavy scraper blade, y capable of carrying 1 the contents of two 1 big dump-wagons, is mounted on a strong 1 frame supported by 5 two wide-tired wheels. D Theblade is raised and Z lowered by a rack and e © - L ‘VEN if the ends of shafting e 4 nected by any one of a dozen devices. One of the s here illustrated. A part of the coupling is keyed to the end of one shaft, and another part is similarly joined to the other € shaft. Between these two parts I~ the flexible portions of the y couplings extend. g Small bundles of springs, = with slotted holes in each end, join the ends of the two shafts it and are held in place by pins. g The slots provide for endwise d slipping, which must oecur 8 if the two shafts are slightly out of angular alignment as y they revolve. The small figure shows how HE devastated farms of Europe may be smoothed out = a ee ‘and put under cultivation again by the same power that helped destroy them. American ingenuity, which gave the guns, has given Western farmers a big-scale land-leveler that may be the solution of the vast problem of agricultural re- construction wherever heavy artillery has fought. Thousands of American tractors that were used on the western front will probably never return to the United States and England, at least not until the battle-scarred soil California, in the person of Benjamin Holt, gave the world the combined harvester, which cuts, threshes, and sacks grain at one operation; the sage-brush plow and rake, which has cleared enormous areas of desert land, subject to irriga- tion; and a huge land-leveler, which has flattened out the surface inequalities of these areas and so fitted them for the easy distribution of water. It was a baffling California soil condition that inspired Holt also to produce the ‘‘cater- ’- A Cure for “Shell-Pox.”” | How the crater fields of France’ may be reclaimed by American machinery pinion. The pinion shaft may be operated either by How the cater- a large hand wheel or a belt drive from the main axle. pillar tractor cn ah es The great guns which stood hub to hub at Chateau-_ fighting clothes Thierry and smashed the last German drive will, let: on. This type us hope, have nothing more to do for generations. = a But the tractors diverted from American farms, like - i" Re cosa the Yanks themselves, are ready to lay aside war equipment and help to rebuild Europe. tractor to haul their great to support life. Hitched to a land-leveler, this tractor does the work of thirty-six horses and six men. It can go any- where a tank can—and a tank can go anywhere Here Is a Good Way to Join Wabbling Shafts do wabble, they can be con- _ the little bundles of flexible couplings or springs are made up. When the raised pin is lifted a little higher, the two parts may methods used with the shafting of dynamos and motors is _ be forced together and the pin can then be driven into the slotted hole. ‘The other end is pinned in a similar way. The larger figure shows how . number of these smal] bun- ES aera es of springs are arranged ae about the ends of the shafting. They are held in place. by suit- able springs. The flexibility of the spring bundles, in con- nection with the slot movement referred to above, allows for any misalignment of the shafts: Flexible Pin Units The correct aligning of shaft- Spring Retaining Ring. ing has occupied the minds of a ——~Flexible Pint Units) engineers for a great many The two parts of the small coupling are pinned together years, and any improvement and arranged in the larger one to make the joint fiexible in methods is always welcomed: 79

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Taking thought and some dynamite cartridges, a motor-boat enthusi- ast found an easy way to cut a channel through a bothersome shoal It Was Dynamite that Did It HERE wasn’t water enough ove: a shoal in the Mascoma river in New Hampshire to float small motor-boats, but there was too much to allow men to work there with shovels or with teams and scrapers. W. A. Saunders, who had used dynamite for stump-blasting, solved the problem. He buried dynamite cartridges of 75 per cent strength a foot and a half in the gravel on the shoal, spacing the charges two feet apart, _ put a blasting cap on the middle charge, knowing that the other charges would be set off by concussion, and let her go. There followed the wonderful water curtain display shown in the picture, and up with it went enough of the shoal to leave a channel two and a half feet deep and five feet wide—which was all the motor-boat owners needed to make them happy. : _ These Stock Supports Are Adjustable HEN one end of a long pipe is of newer design. The screw is com- being worked on in a machine, pletely hidden in a'very substantial the remainder should be held up. base, whereas in the older one the screw Several of the many kinds of stands’ is exposed and the base is small. for supporting stocks have fixed heights which may not be convenient for the work at hand. The supports shown here are adjustable, and may be screwed up or down to suit the operator. That, part.of the support on which the:stock ac- tually rests is cylindrical in shape, and is grooved ; so that the pipe may rest. securely. . ine Asupport like this may . be used in connection with hacksaws, screw ¢ machines, band and'‘cir- 7] cular saw machines, bolt- cutters, etc. The two supports~- shown here are different in style-but alike in prin- ciple. . The nearer ‘one is

He’s working at only one end of the long pipe, and so he uses a new adjustable sup- port to hold up the other 80

A Gun that Shoots Stuceo at a House Speen by hand is slow and the results poor. For exam. ple, when a metal lath is plastered’ by hand three coats are necessary and even then the mortar seldom reaches through to the back of the lath. | The result is that the metal deteriorates, causing loosening of the plaster so that repairs are constantly necessary. But the centrifugal guy Fy this method he covers 450 sq. ft. an hour hurls mortar at a lath with such force that it is sent through the lath to the very back. This so-called gun is really a small machine consisting of a 1<-horse- power motor with four spider blades attached to it. When the motor is started, the blades revolve and hurl out the mortar. The bearings are protected from grit and cement by heavy felt gaskets. The gun is at- tached to springs fastened to a strap which fits around the operator's neck, leaving his hands free. - The entire outfit weighs only thirty- two pounds. One man operates the gun, while a helper stands by. to feed the mortar into the machine. The illustration shows the opera- tor applying stucco’ to ,a concrete wall. The machine may also be used on brick surfaces with’ equal success. ; : og Other things besides cement can be hurled from this gun. It has been used for water-proofing the inside of a large pit, and may also be used for hurling pebble dash of any desired finish. It works very: rapidly, coating about 450 feet of concrete in an hour. Popular Science M onthly a

It a r 8 f a a I 8 é

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‘March, 1919 A Streamline Coaster ed % that Any Boy Can Make he tal It can be done with ordinary tools and materials he tly un By Edward R. Smith All boys like to coast, and they will be espe- cially delighted with a coaster of this type. ‘ - Easily constructed, it 2 may be fitted out with / automobile accessories F that are inexpensive or level pavements of any length, the pushmobile and coaster appeal to the boy. The illus- ‘ tration shows a streamline coaster, that any boy can make. Designed for speed, it is strongly built, easily steered and controlled, yet very light. The materials can be purchased for a small W HEREVER there are long hills

file or wire-cutter, and a jackknife are the necessary tools. In addition, a chisel, plane, pliers, monkey-wrench,

ich nail set, automatic or breast drill, ath spokeshave or draw-knife, tin-snips, and square will be found useful, a Materials Needed for the Coaster - - The following list of materials will url be required for the construction of the are coaster: : : by Three 10-ft. 4-by-14 or 5%-in. pine at- boards. ; rap Three 214-ft. 1-by-4-in. boards for wai the axle and tongue. The Several short lengths. ty 45 ft. of No. 15- or 18-gage gal- sti vanized wire. by 11 ft. of canvas of 4 ft. width. ing. One wire spring for the brake. ori [ Four wheels. rete Nails, bolts, screws, and paint. ial Build the Frame First Pores The frame of the coaster is built has first. Three pieces of pine or some the strong, clear wood, 4 in. wide, 4% or alas 54g in. thick and 10 ft. in length, are lash selected for the sides. Two of these very ° must be sprung to shape as shown in t of Fig. 1 and 2. If they are stiff, they should be placed on a box or sawhorse and weighted at the ends, as shown in

sum. A hammer, saw, brace and bits, © Fig. 3, then boiling water should be poured on the upper side of each piece. This will soften the wood so that bend- ing will be easy. To prevent splitting, make the nail and screw holes with a drill. Strips of tin will reinforce the frame-joints.

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15- to 18-gage galvanized truss-wires are hung beneath the frame and se- curely fastened on top of each end block. They are tightened by forcing them on the truss-blocks. The wheels fixed to their axles, Fig. 11, are pivoted to the end blocks with

Wt / i } =A |

BRAKE-SHOE.° BOTTOM VIEW FIG.2 The chassis as it will appear before the body is attached The third 10-ft. length is cut in half. These half lengths are nailed to cross- pieces, 1 by 4 in. and the other 2 by 4 in., cut to take a steering brace, Fig. 7. Truss-blocks should be fixed to these cross-pieces before they are nailed in place. The 10-ft.. lengths are screwed or firmly: nailed to the end. blocks, and when dry, are bent around this inner brace, Fig. 8. The end blocks are sawed from 4-in. stuff, or built up as shown in Fig. 9 and 10. Number 81 a bolt, screw, or spike. Opposite ends of -the axle are connected by equal lengths of wire, Fig. 8. To the front axle a steering tongue, Fig. 13, is fastened by means of metal or leather hinges. The steering wheel, Fig. 12, with its shaft and connecting arm, is fixed ii. place and pinned to the tongue. The tongue should swing clear of the axle wires, yet be low enough to follow a foot-rest nailed to the frame. Depending upon the

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_ gtrength of the wheels, two or more ‘seats may be nailed to the frame. _A friction pavement. brake is next put in place: “The brake-piece, swing-_ ing between parts of the frame and normally ‘held up by a spring, is forced agairst the pavement: by means:of.a lever connected to the drag with a wire. A shoe is bolted to the drag for ease - in renewal.

Try It Out Before Proceeding At this point a trial may be made to test the coaster. If satisfactory, it is ready for its casing or superstructure. This is made of canvas stretched over a wood frame. It is much lighter and more quickly and neatly put on than sheet-metal or wood. The dimensions of the frame are given in Fig. 4 and 5, while the canvas cut-out is shown in Fig. 6. It is better to make a pattern of newspapers pinned or pasted to- gether to insure a good fit for the canvas. The canvas is stretched to the frame and fastened with carpet-tacks. With a coating of paint and, if cesired, the addition of a horn, bell, or other form of road-clearer, the coaster is ready for service. \ Within certain limits, dimensions and materials may be changed to meet the means and desires of the builder, It is a coaster, not a model motor-car. The hood conceals no motor, but - rather protects the steering gear and une driver as it cuts the air. The after-decking allows the air gradually to close in. In short, it combines ideas in streamline design with ex- ‘| treme simplicity in construction. Sk SSE Ry EEE EE a SR EAD ET wg Jal ¢ 5 a

iN | ‘4 i) H \ Vi

Steaming the boards, and the

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For winter coasting, runners (Fig. 14) may be fitted to the axles in place of the wheels. A special shoe (Fig. 15) makes the brake effective on ice

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speed can be made on a level paye. ment. In winter it becomes a speedy motor-sled. Swen TRUSS BLOCKS <<

Bette,

An. air propeller provides a second

TOP VIEW BOTTOM VIEW BRACE * The coaster as it will look in process of construction and snow. Because of the fact that both axles turn, the center of the car runs parallel with the line of motion. With a motor wheel fixed to the frame at this point, a fair

| it =

TOGETHER.

" Sd ee an . a 4 shape of the canvas when cut : 82 method of propulsion. These motored propellers can be purchased, and if used must be mounted on a frame toward the rear of the car, with con- trols wired within reach of the driver. This, too, equipped with runners, will skim over ice or packed snow. Thus, with a few changes and some additional expense, the boy living in a city may somewhat compensate for the lack of a convenient coasting hill.

How to Get a Small Amount of Gasoline from a Locked Cask N employee carelessly carried the gasoline-barrel key to town with him instead of turning it in at the office. The faucet was similar to that shown in the illustration and the cask was full of gasoline and too heavy to be lifted and turned from its stand so that the top hole or outlet could be {f used. Arubber tube could have been used as a siphon, but

In drivi ta d there was none yaive care chould be at hand. taken not to strip The gasoline threads of the valve needed was ob- tained in the following manner: The nut on the tapered piece was loosened, and the tapered valve driven up, and there was enough play to give two small streams of gasoline, which were caught in a quart measure.—H. W. HAHN.

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fe NSE The boy shooting in this picture is just a beginner: his formis a little awkward and cramped. By using his left i knee to support his left elbow, his aim would be steadier. wa Fn aS a a A safe bullet catcher for indoor use In standard use among the W. J. R. C. boys NE of the safest bullet catchers to use in shooting i$ likewise the easiest to make, as proved by the number in use among Winchester Junior Rifle Corps boys. It’s just this, a packing box banked up on the inside with Sharpshooter sand. oe This sand is what will stop your bullets. It should be very fine—no large stones. Fill the box as shown in the illustration. Bank it up to the top at the back and let it take its natural angle of rest, that is, the slope at which it stops sliding. Now this makes the best possible backstop ‘for indoor or outdoor use. Sand stops a bullet as nothing else will. Bags of sand are used on the parapets of trenches to stop the high velocity bullets of the regular army rifle. To take care of the oc- casional wide shots of a beginner, there should be a larger backstop behind and around the main bullet catch- er. This can be made of a large sheet of boiler plate— Y inch thick and about 4 feet by 4 feet. This must be covered over with boarding at least 7% inch thick to keep the bullets from rebounding. With such an outfit as this, you can shoot with perfect safety in your back yard, or if you live in the city, in your cellar or attic. You can enjoy in good If the box were filled right up in front, the sand would trickle out of f every hole made by the bullets. The manship and better sports- sand must be rebanked frequenily as manship among boys and the bullets make it slide. WINCHESTER Take-down .22 caliber single shot rifle. A low priced, light weight gun made in two sizes. QINCHESTER MODEL .06. Take-down Repeating .$2 caliber rifle, 20-inch round barrel. Shoots three sizes of ammunition. The most popular .22 caliber repeater ever placed on the market. WINCHESTER JUNIOR RIFLE CORPS or bad weather the fine sport of rifle shooting which every boy longs for and ‘never outgrows. Start a W. J. R.C. “Unit’’ The job of finding a place to shoot, rigging up a range and getting your rifles is always easier and cheaper when you have a bunch of your chums in on it. There’s more fun, too, in the actual shooting when there are other fellows to compete with. So why not get together with half a dozen of your chums, join the Winchester Junior Rifle Corps and organize a regular Unit or Club which will be officially recognized at National Headquarters. Any boy who gets a Unit started gets a Special Service Pin.” The W.J.R.C. will help you from start to finish in rigging up your range and in putting it on a paying basis. The W.J.R.C. gives you all the instruction necessary to become a real expert in the use of a rifle. It provides for officers, supervisors, instruc- tors to make your shooting safe. : It costs you nothing to join the W.J.R.C. There are no dues and no military obli- gations whatsoever. The W.J.R.C. was organized sole- ly to encourage better marks- girls: of America. It is in- tended to develop the quali- ties of fair play and manliness which are essential to success in after life. Any boy or girl not over 18 and who is in good standing in his or her community is eligible. Membership in the W. J. R. C. covers the entire United States. There is hardly a town now that has not at least a small “Unit” of the big Na- tional Organization, where boys are learning to become expert riflemen and are competing among themselves for the famous Winches- ter Marksman and Sharpshooter Medals. You, too, can earn these trophies of marks- manship if you join the W.J.R.C. and start shooting now. Get the official plan and handbook Write today for Winchester Junior Rifle Corps “Plan for Organizing a W.J.R.C. Unit,” and for the official hand-book —‘‘Rules of the Winchester Junior Rifle Corps” and ee to Handle a Rifle _ Safely.” This booklet tells See ene. you all about the WIR. Cal., winner of and describes in detail the Winchester MarksmanMedal fine points of shooting — alignment of sights, the 3 correct positions, rules for gun safety, the care of rifles, and the proper rifle for you to use. If you are a boy scout, give your name in full, the troop you belong to and the name of the scout master. If you are not a boy scout, state what boy organization, if any, you be- long to, giving the name of the official in charge. - National Headquarters Winchester Junior Rifle Corps 276 Winchester Ave., New Haven, Conn., U.S.A. Division 320 Winchester Junior. Rifle Corps National Headquarters, 276 Winchester Ave. New Haven, Conn., U. S. A. Division 320. Gentlemen: _ Please register my name as a member of the Winchester Junior Rifle Corps, and send me a membership button and certificate of member- ship. Also tell me how to organize a Local Unit of the W. J. R. C. Very truly yours, OMNES on icc baw owac go anaoaiphan anata Stueet MGdge3¢:. ... ... 55s Se eee een A ea 7 ea aE SER x 83

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Ce ee ee ee tier gh aiehuthaonge ll ere A Good Scrap-Basket for a Sewing-Machine NEW fish-basket makes a handy scrap-basket for the busy sew- ing-woman. The small hole in the top ic at exactly the right place to catch bits of cloth and any threads IK tA P i 4 GA N\\\ \ \ Od, L957 -? a A fish-basket hung at-the end of the sewing- machine to hold.scraps of cloth and threads that are clipped, and the holes in the back of the basket make it easy to fasten it to the side of the machine with a strap. The fact that it is off the floor saves labor and makes it inconspicuous.—C. P. FONDA. Locating a Reversed Coil in an Armature JN armatures where both leads of a i coil tap to and lead out from a cer- tain point there is danger of getting the leads crossed while making con- nections, thus reversing the direction of flow of the current in that coil. Such reversals in all cases “‘light out” Testing out armature coils with. the use of a millivoltmeter and magnetized bar as if perfect when tested with a lamp, but will cause bucking when the ma- chine is run. A reversed coil of this sort is un- usually difficult to locate, and very often a whole machine has to be stripped because ordinary methods of test- ing fail to locate the trouble. The most efficient test the writer has yet been able to discover, and one that has never failed to work, is illustrated in the sketch. It will be seen that a millivoltmeter is used rather than a volt- meter. This is because of the great sensitiveness of the former instrument. | Connect both terminals of the meter to adjacent com- mutator bars. Next, take a piece of metal that has been magnetized, and move it in a direction correspond- ing to the revolving of the armature and directly above the coil to which the meter is connected. It is well to keep in mind the fact that, if a clockwise motion is used on the first coil, the same direction must be retained on all the other coils, or the meter reading will be back- wards. On the downward strok of the magnetized bar, and _ as it approaches the coil to - be tested, magnetic lines of force will travel from the bar to the coil, thence to the meter, causing the needle to fluctu- ate slightly. If the needle jumps ahead on the downward stroke, it will jump on the upward stroke backward, and vice versa. The reversed coil will read opposite from the others. To change the direction of the fluctuations of the needle, either reverse the meter terminals or reverse the motion of the magnet.— MAURICE CLEMENT. A Substitute for Storage- Battery Separators N rebuilding a storage bat- tery, it was found neces- sary to replace the wood separators with new ones; but, as these could not be procured, substitutes were used which proved satisfac- tory and which were obtained at practically no expense. A small packing-case in which a motor had been shipped, furnished the mate- rial. The sides of the case were three-ply veneer. These pieces were soaked in water for a time, and then the plys were carefully sepa- rated with a_ thin-bladed carving-knife. They were then dried between two boards to prevent curling up; and when dry the glue was removed with sandpaper. The final step wastosoak them foracoupleof days in diluted sulphuric acid before cutting. The veneer was 1/16 in. thick and was cut with snips.—JOHN A. WEAVER. 84 Popular Science M. onthly- Here’s a Flyer Sled Made to Drive by Hand-Power HE owner of a flyer sled can make it into a hand-driven machine by means of the few attachments shown in the illustration. A shaft is A hand-driven attachment for the flyer sled, made of bicycle sprockets and a chain supported in front which has a crank on each end and a small sprocket- . wheel attached to the center between the supports. Farther back is another bracket support for holding the crank- shaft and its bearings. This may be taken from an old bicycle. Two long wood arms are used for the pushers. They are attached to the cranks on the first-mentioned shaft. The end of the pushers have claws made from cutters taken from an old mowing-machine. Any other thin piece of steel will do, as long ag it is bent to take hold of the hard snow and ice.—DALE R. VAN Horn, An Efficient Tool for Cutting Circular Gaskets HERE any quantity of circular gaskets are used or much cir- cle-cutting is done, there is need of a cutter that will do the work both quickly and accurately. Such a de- A home-made tool fastened to the bench-top; it cuts a gasket with one turn of the crank vice can be made from materials usual- ly at hand. One of these devices is shown in the illustration. It is ad- justable to the various sizes needed in the work.—CHARLES H. WILLEY.

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March, 1919 ry it wn Rm ® eS OLE A “ * aes RK Oe oY . | VERY boy should have a voice in buying his own bicycle. It: is a good lesson in business judgment. If he is a wide awake boy he has looked into the matter and done some in- r . vestigating on his own. He has asked older boys particularly a : about tires because good tires are necessary to a good wheel. h : An investigation like that will show that the big majority of experienced riders will say “‘Be sure it has United States Tires.’ They have found that these tires are always reliable, they resist punctures and cuts, they give longer mileage and do not need to be renewed so soon. The boy with business instinct will learn that United States Tires are made and backed by the world’s largest rubber man- ufacturer, and he will point out the U. S. Sealoa each tire, which stands for quality in rubber goods wherever you see it. = Then when it comes to picking out the bicycle in the store, he will know, and he will insist on United States Tires. re Ue There are styles to meet every need—both . clincher and single tube. United States Cycle Tires are Good Tires ‘

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| ; | How to Make a Height Measure for Trees N instrument for measuring the. heights. of trees can* easily .be made at practically no cost. Take a piece of 14-in. boafd7 by 9in., and plane it smooth on all sides. Draw the line AB % in. from the lower edge and parallel to it. Draw the line CD 2 in. from the left end of the board _and at right angles to AB. Make a mark at E, 614 in. from D, and another at F, 3% from D. Now draw a line JK through F parallel to AB. Start at D, lay off ~ inches and quarter inches on AB in both directions, mark- ing D as zero and putting down the number of inches from D to-each inch mark. Do the same for the line J K. Take a brad or small nail and drive it’ in carefully on the line JK about 1 in. from the edge of the board. Drive it in until the point comes out on the back of. the board; then pull it out-and drive it in from the back until the point sticks out about 14 in. from the face of the board. File off or cut off with pliers any part of the brad that projects from the back of the board. In the same way, insert another brad near the other end of the line J K. These brads are the sights, and it is important that they be straight and true. - Take a piece of straight heavy wire 10 in. long, and bend one end of it into a loop about 1 in. in diameter. The center of the loop should be in line with the straight part of the wire. Fasten this piece of wire loosely to the board at E with a 14-in. screw, so that + = t=) " Should: the screw be too tight the pointer will not swing freely it will swing freely when the board is on edge. The loop should be large enough to fit loosely over the shank of the screw, but small enough so that it will not slip off over the head. Serew a piece of wood about 6 in. long 1 in. wide and % in. thick to the back of the board to serve as a handle, and the height measure is com- plete. at ‘To measure the height of a tree, stand at a distance of 100 ft. from it, and hold the ‘instrument in the right hand in such a way that the pendulum ‘swings freely but very near the board. Sight along the brads at the top of the tree and let the pendulum come to -rest.. Then with the left hand press the pendulum against the board without > : Nemec HAA Ry uN Sy bh A it a ie ‘ ut \ \ PP retrene ak en Sigg > a a fe > ha ae ' If the board is not slightly tilted the reading will not be accurate giving it a chance to change its posi- tion. Read off the number of feet in height on the lower scale. If the wire crosses the line 5 in. from the point D it indicates that the tree is five 16-ft. lengths or 80 feet high above the level of the eye. Now sight at the foot of the tree and take another reading. If the pendulum hangs to the left of D, that is, between A and D, add the amount indicated to the first reading, and the result will be the total height of the tree. Thus, if it hangs )% in. to the left of D, add half a log or 8 ft. to the first reading, making a total of 5% logs or 88 ft. But if the eye is below the foot of the tree, the wire will hang to the right of D,—between D and B —and then the amount of the second reading should be subtracted from’the amount of the first. Thus if the first reading is 96 ft. and the second is 12 ft., —to the right of D—the total height of the tree will be 96 less 12, or 84 ft. If the tree is less than 75 ft. high, or if it is difficult to see the-top at a dis- tance of 100 ft., the observer should stand 50 ft. from the tree; but in this case thé readings are on the line J K. When the instrument is sighted, the pendulum can be kept in position by tilting the hand slightly to the right. This brings the wire against the board and holds it in place so that a reading can be obtained. Care should be taken however, so that the wire will not slip after the board is tilted. In the example given the total height of the tree has been measured. It is often of more practical importance to measure the height to a point on the tree beyond which there is no ‘merchantable saw timber. This mea- surement is made in the same way as es Popular Science Monthly that.described, except that the in- strument is pointed at what will be the top of the last log when the tree ig cut, and then at the point where the top of the stump will be. You Should Have a Gasoline- Tank Gage-Stick ANY an automobile-owner whose car has a gasoline tank without a gage for recording the fuel gallons in it has wished to have a simple stick which would enable him to estimate the contents of the tank quickly. The accompanying chart, prepared by the Society of Automotive Engineers and published in that Society’s data hand-book, will enable them to figure out the volume of any cylindrical tank placed horizontally, and to calculate the distances on a stick to correspond with any number of gallons. Suppose you had a car with a tank 12 in. in diameter and 40 in. long, and wanted to know how many gallons of gasoline it contained when full. Read along on the bottom scale until the figure 12 is reached, then trace a line vertically to the point 1 and note that it cuts the curve marked “curve of gallons per inch of length” at .49, reading on the left scale of gallons per inch of length. Multiply this factor of .49 by 40, the number of inches in the length of the tank, and the total volume of 19.6 gallons is obtained. Next,"suppose that for the same tank you want to make a stick showing the number of gallons in the tank cor- 100 1000 950 F 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 150 100 QS0 t) GALONS PER INCH LENGTH FACTOR FOR DEPTH OF LIQUID a: Oe. 8 3: Sh : 2 4 5 6 7 8 9W PARTS OF VOLUME 10 105 I. NS 12 125 13 135 14 145 15 TANK. DIAMETER A chart with which one can estimate the contents of a gasoline tank quickly responding to any level of the fuel in the tank. For instance, let us find where to mark the stick if there are three gallons in the tank. First find the decimal proportion of the number of gallons taken to the total volume. This gives 3 divided by .19.6, which equals .153. ‘ Then on the horizontal chart labeled “‘parts of volume”’ find the point .153, and move your pencil up vertically to the point marked 2 where it intersects the line marked “curve of depth factor of liquid.” Multiplying this unit of .213 by 12, the depth or diameter, . gives 2.556 or 2 9/16. in. The mark to indicate that three gallons of fuel are in the tank should then be put 2 9/16 in, above the bottom end of the stick.—J. B. BRINKER. _ ,. —-

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ee eee ee ee, oe ee, SS SaaS eS eh Um Soe Vw ~ The Mighty —e Cloud and the Rery little Cohumibia a are first cousins HE mighty thunder cloud often generates and wastes 150 thousand horsepower, when it hurls its terrific bolt flashing and crashing through the sky. The fiery little Columbia generates a fraction of this volume, but sends its power on a specific errand, through wires, under - control, without waste. It is electricity in both cases. But the mighty thunder cloud works at the com- mand of Nature for an unknown purpose. The fiery little Columbia works at your command for a definite use. THE DRY BATTERY "THE Columbia Dry Battery is the handy- man of the world. It ignites stationary engines, autos, trucks, tractors, and motor- boats; rings bells and buzzes buzzers; lights lanterns and makes telephones talk; runs toys for the youngsters. Motorists the world over know the wis- dom of sonbeie h the extra set of vigorous Columbias—to be connected in a jiffy Columbia _ Storage and Dr Batteries — when the regular ignition begins to loaf. THE STORAGE BATTERY "THE Columbia Storage Battery is so hale and hearty it is guaranteed to do defi- nite work for a definite time. Its health certificate even stipulates that another bat- tery will be put to work for you without additional cost if the original should fail within the guarantee period. A unique plan is back of this Columbia Storage Battery Service. Any Columbia Service Dealer will test, charge, or water your battery. But if surgery is necessary, he will pass it along—with its seal un- broken—to a nearby Columbia Service Station, where only competent experts will open it and remedy it. This plan heads off tinkering—which,as youmotorists know, is responsible for half your battery troubles. Columbia Service Dealers or Service Stations anywhere will be glad to demon- strate why and how you—like legions of other automobile owners—will prosper with Columbia Quality and Service.

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You may have your alee of more than 2,000 instruments } may send it back at Fourth St., ‘abash Ave., be Redolph Warlitzer Co. Criss) EG for a week’s trial in x seus sare hope. Play it -as if it were our expense. Just our name scan address on Send 1 the Coupon! the coupon now. Please state whet // are interested in. There is no obligation. j you poe fren big 160-page book free and prepaid. Send coupon now! ' cinnati, O. icago,! i. fl your own. Then, if you wish. on I Trial does not cost you a penny. Don’t miss this big Convenient Monthly Payments /....... The Rudolph Wurlitzer Co. If you decide to buy you may ay the low manufacturer’s piso ot the vate of a few 1 cents a day. The na name "‘ W: "has stood for the est qualit: wality for for nearly F Pith Se = 5, Chlendo, li centuries. y known musical ument — fa at Y Gentlemen: —P’ manufacturer's tard We’ve supplied U.S. Gov’t wi for 55 prom-ehe apd ge yor Uf Also tellabout your epecial offer direct We will Make This Your Business at $3,000 per Year Automobile Tire Surgery. There isn’t - a business you could get into that offers such sure possibilities of success and fortune. One man and a Haywood Equipment can make $250 a month and more. Scores already have done it and this year there is a greater demand ever for tire repair work. “30 Million Tires to Repair” That's not a myth nor some man’s dream. It’ = an actual _ The factories ev for the blgwe enlarging th plants LA. est st period of t ine the aut 30 muon tires wil will be mane- nen a every one will need —s No Experience Necessary No previous ge bey E, no Pape We have a cc wry ws illustrated, t! ag tod 3 mae with each ei equipment, I “you ~~ B a ‘ou can quic become an e atte Handi “4 ‘all kinds of pricesat big cash profits. Nothing is easier to master completely. pon below, a i full information— interesting catalog. Tells all about to hows how to INVESTIGATE. Send the cou yee and tiow them: S dent. Do this Today" NOW— before you forget | it. _ Haywood Tire & Equipment Company 1167 Capitol Ave., Indianapolis, Ind. SS 2S a ek Oe a FREE i ere S ‘COUPON Tire & Senpmont Ge. 1167 capitol Av Ave. Indian send me apolis, Ind. t ‘ | ew A rape em catalog, i asines. Name Tire Repair business seeeeesesesd DIRECT FROM gt To you OUR NEW CATALOG WITH 600 OF THE ee "xX TO-DATE ‘DESIGNS FREE. GROUSE CO. he oe pl, North Attleboro, Mass. , SS JASSPINS-RINGS If you are earning less than $50.00 PER WEEK and like to draw—you should study COMMERCIAL ART Leading Art Managers—the men who know— recommend us and employ our students. We will guarantee to make you successiul—Learn at home in your spare time—or in our resident school—Day or evening. Write for FREE illustrated catalogue. COMMERCIAL ART SCHOOL, 721, 116 So. Michigan Ave., Chicago, Ill, Bah vexea show Hale [= Il I teac’ N sonally, by = ina ne short time. Oldest and largest School. | Big field, work interesting. Toa ce can |} 45 A WEEK \ mane sie see A WEEK Ww 00 while apres FS, kage DETROIT Son CHOOL, OF LETTERING Fritzner, Minn fas ‘$10, Spare Time Work with Popular Science Monthly Hundreds of active men are working for PopuLar ScIENCE MontTsiy in their spare time. PopuLaR ScieNcE MonrHuLy is growing so fast that it has opportunities for additional men in communities all over the country. Can you arrange to give an hour a day, or one day a week, or one evening a week? The plan can be adapted to your time. Now is the time to apply. Popular Sciente- Monthly 225 West-39th Street; New York 88 02 Popular Science Monthly Locating Grounds on Alternating. - Current Circuits N case a ground develops in an al. ternating-current armature or field,a resistance measurement will generally give the location at which it occurs, The resistance measurement is taken as follows: Measure the resistance of the ground circuit, or phase; next, measure the resistance to the ground by connecting one line to it; then measure the other end of the resistance to the ground, connecting one measgur- ing line at the other terminal of the phase and one to the ground. Assum- r ing accurate measurements, the sum of the latter two will equal the first, and the ground will be as far from one terminal as the resistance from that terminal to the ground is of the total resistance of the phase. Ground Ty A B Illustrating an alternating circuit in which an unknown ground is to be located The accompanying figure illustrates this explanation. If the total resist- ance between A and B, the two ends of the circuit, or phase, is one ohm between A and the ground is .45 ohm, and between B and the ground is 55 ohms, the ground is located 45-100 of. the distance from A to B. If, for example, there are ten coils per phase, the calculations and measurements show that the fifth coil is grounded, counting from A.—PETER CLUTE. A Very Serviceable Pipe Vise Made from Scrap HE illustration shows how to make a very satisfactory pipe vise from old scrap junk. The lower jaw is made in two pieces from )4-in. flat iron, the material being bent as indicated, and the notches for the pipe grip cut and filed. Holes are drilled The scrap-iron vise set up and these jaws secured to the bench. The upper jaw is made of a single piece with two straps riveted across it. This, with two long bolts, completes the vise.—CHARLES H. WILLEY.

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1 Front and rear mudguards, splash pro- 5 Seventeen process enamel finish ofDay- _. Double anchored fork sides with solid Re tector and stand on all models. - Carmine. Pano ee } wien, steel spool between plates. h Special design rear fork giving extra eavy coat of Copper under all nicke Front hub and cups of special de- d 2 clearance between wheel aie sides, plating. 9 sign turned from solid steel bar. Two- Flush rear fork ends. Ths f head adiusti E point frictionless bearings. s 6 nee ee eee ee. See Vitalic DeLuxe or Kokomo Everlaster tes 3 Drop-forged seat-post cluster, giving ee ee 10 sei seeced maple rims. st- extra strong grip On seat-post. Se 1 One:piece drop-forged cranks. ds ' 4 High-grade padded leather saddle with Outside joint head construction. Eleven Hobbed sprocket. Th double action springs. Leather tool bag inner reinforcements in frame, all dip- 1 Seamless crank hanger bracket, extra ae and complete tool equipment. brazed. reinforced. 55 | of. for . - Se, ERE are good reasons for the acknowledged superiority of Dayton nts : Bicycles. A few of them are stated above. Study them! It is points ed, such as these that mark the difference between a bicycle that merely : looks good and a bicycle that actually is good. Dayton Bicycles are designed land built with painstaking care. They : embody every known and tested feature of design and construction that can make for beauty, simplicity, efficiency, durability and comfort. A Dayton Bicycle may be purchased with absolute confidence in the to real satisfaction it will give and in the actual economy it will effect. al There are eight models in the fine new 1919 Dayton line—a bicycle to So meet any need. Each Dayton Bicycle bears the “Davis-Made” trades _ ae mark—which is a reminder and a pledge of quality. Dayton dealers will ins gladly show you the Dayton line. See your Dayton dealer—and write to ye We Back This Trade-Mark us for our new Dayton Catalog. It is free. Ask for Catalog B.-7. ia ig sas Cycle Dept, THE DAVIS SEWING MACHINE CO., Dayton, Ohio

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Fibre fi; Reconstruction! HE war is over, but the battle of keen competition is just beginning. Recon- struction abroad means reconstruction at home. Success is based upon efficiency and efficiency begins with the raw material. Diamond- Fibre represents progress—a step forward in the industrial field. Here is a modern material (in sheets, rods, tubes or special forms) that will stamp, drill, punch, thread, tap, turn or mill. It contains no grit or edge-nicking elements and can be machined with but little wear on tools: It can be had rigid or flexible, is almost indestructible and will withstand severe vibration without crystallizing. It is strong, tough, homogeneous, non-conductive to electricity and remarkably high in tensile, compression and shearing strength. It will take a high natural polish or can be finished with paint or varnish. Its easy workability saves overhead. Its light weight saves freight. Have You a Problem? ‘Do high costs and material scarcity bother you? Investigate Diamond Fibre. Get in touch with our Trade Research Department and learn the many merits of this remarkable material. Tell us your problem and let us try to help you. Diatie Diamond State Fibre Company Bridgeport we. We manufacture CELERON and CONDENSITE -CELERON —two remarkable new water-resisting materials. We also make the well known line of Diamond-F Protective Papers for food products, etc. (near Philadelphia) Penna. Popular Science Monthly Soldering Large Vertical Cables by the Pouring Method ” ay solder any metals and make a i good joint, it is quite necessary to bring the metal to the temperature . of the melted solder. Large cables cannot be heated well with a torch or soldering iron, and for these the pour- ing method is generally used. To do this properly it is necessary to have a form through which to pour the metal. While it is passing it heats the cable, For this purpose a piece of leather may be cut to the shape of a funnel, with a strap attached to hold it around the cable. The illustration shows the pouring of the solder, with the kettle set to catch it as the molten solder | Ah FAY ee A labor-saving means Of pouring solder that assures an even temperature flows through. Asmall leather spout may be attached near the bottom of the funnel for running out the solder.—ELLIOT C. HARRISON. A Good Way to Keep Paint-Brush Handles Clean JOB of overhead painting has some objectionable features, and one of them is caused by the paint continually running down over the brush handle. The picture here- with shows how a few pieces of tin can be formed into a simple catch or trap for the paint and _ soldered to the brush An indispensable device ferrule. It is for the amateur painter worth the small amount of time required for making it if the painting is to cover any area at all. It insures a clean handle.—F. W. BENTLEY, JR.

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Oren i ed ee eae ee re Me Aa peg ate sk Laat The Amplifier = Two New “Fs Which Won Millions of Friends \ X HEN the now famous Brunswick was announced, most people believed that the utmost had already been attained in the phonographic art. Hence they expected, and rightly so, that The Brunswick would have to bring out over- whelming betterments in order to win a place among the leaders. And this great expectation was realized. The Brunswick created a memorable sensation. It commanded instant respect and admiration. The Pioneer Of the major instruments, The Brunswick was the first to play all records with faithful regard for different requirements. This feature alone created thousands of admirers. For it meant that a Brunswick owner could buy and play any record, whatever make. Since different makes offer different artists, and no one make offers them all, music lovers saw in TheBrunswick the opportunity to select their own library of records, without restriction. The, other outstanding Brunswick better- ment was in tone production. By a more Branch Houses in Principal Cities of United States, Mexico and Canada The Brunswick-Balke-Collender Co. General Offices: CHICAGO and NEW YORK scientific amplification of tone waves, The Brunswick overcame many old time crudities and brought out lovely tones hitherto lost. Today The Brunswick Method of Repro- duction is a recognized triumph. It means perfected reproduction to all who know it. And the news is spreading fast. Two Famous Ideas The Brunswick Method of Reproduction includes the Ultona, an all-record player. This master invention can be obtained on no other phonograph. The Ultona presentsto each make of record, the proper needle and diaphragm. All at a turn of the hand. It is a unique re- producer, not an attachment nor makeshift. The Brunswick Method also includes The Brunswick Amplifier,. an all-wood sound chamber built with scientific regard for acous- tic laws. No metal is used because it muffles sound vibrations. Before you decide which es for your home, hear The Brunswick. Compare its tone. Note the Ultona. A Brunswick Dealer will gladly assist you in making a tone test. Canadian Distributors: Musical Merchandise Sales Co., Excelsior Life Bldg., Toronto

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Electrical Devices and How They Work Popular Science Monthly XV.—Dynamo and Motor Troubles enumerated the usual and common troubles occuring in the operation of dynamos and motors, with their causes, symptems, and remedies. They are given in the order in which they are most likely to occur, and it will save time to test for causes in the order listed. It is well in all cases, not to jump at conclusions, but to make a careful examination first. Since the G _——Brush holder |: the following paragraphs are Fig:4 Method of Sandpapering Brushes to Prevent Sparking ‘ construction of direct-current genera- tors is essentially the same as that of direct-current motors, most of the troubles inherent to one are also en- countered in the other; in other words, the remedies for generator and motor troubles are quite similar. - Stop or Failure to Start 1. Fuse melted or blown. Open switch, take out blown fuse caused by short-circuit and put in new fuse. 2. Dead line. Test for the current at the switch. 8. Broken wire for connections. Open line switch, locate and repair the break. 4. Poor contact of brushes or in- sufficient tension on the _ brushes. Clean commutator and see that the brushes touch, adjusting tension to secure a light, firm, and even contact. 5. Heavy overload. Reduce load on motor to its rated capacity or less. 6. Excessive friction. Armature rubs, bearings run hot, or the belt is too tight. 7. Short-circuited field or armature. Locate and repair, if possible. Care- fully examine all insulation on con- nections and brush-holders. Defec- tive insulation, dirt, oil, and copper or carbon dust often cause short-circuits. Failure to Generate 1. Residual magnetism weak or destroyed. Use magnetizing current from another machine or a battery through field coils in proper direction to correct fault. Test polarity with a compass. . If this fails, shift the brushes backward to make the armature mag- netism assist that of the fields. By Peter J. M. Clute, B. E. 2. Reversed field connections, so that one half of field opposes the other half. This can be detected with a compass. 3. Defective brush contact. This may be due to dirt or oil on the com- mutator, brushes not properly trimmed, insufficient brush tension, brushes in wrong position, or a rough, worn commutator surface. Remedies can be found hereafter under “Sparking at the Brushes.” 4. Short -circuit in the external . circuit. External short-circuits or grounds prevent building up of shunt or compound generators. 5. Short-circuit in machines. . Test for location of trouble, examining the insulation carefully. Sparking at the Brushes 1. Brushes not set on neutral. Shift the brushes back and forth until sparking is reduced or eliminated. 2. Brushes not set diametrically opposite. 3. Brushes not in line. Adjust each brush until its bearing is on a line with the commutator bars. 4. Insufficient brush contact. Due to dirty commutator or poor tension, - allowing the brushes to leave the commutator. 5. Commutator has high, low, or flat bars, projecting mica, or may be rough and worn. Grind with fine sand- paper and polish. If defect is serious it may be necesssary to turn the com- mutator true. 6. Open circuit in the armature. Sparking will occur only at one place on the commutator, thus indicating the location of the break. Defective coil may be temporarily repaired by connecting to -the next coil across mica. Permanent repair should be made as soon as possible. 7. Short-circuited or reversed ar- mature coils will cause the motor to draw excessive current, even without carrying a load. Reversing field coils can be located by a compass. Shorted coils will usually burn out under load, and should be removed, while reversed coils may be connected properly. Heating of the Armature 1. Excessive heating of armature coils is due to over-loading or too much power being taken from the machine. 2. Armature coils short-circuited. Locate the defective coil and removethe cause, which is either poor insulation or moisture. If it is the latter, dry out the armature before starting. This may be done by sending a low current through the winding, or by causing 92 £2 the machine to generate a small cur- rent itself by running slowly. 3. Cross-connection is often caused by a loose coil-abraiding on another coil or the armature core. 4. Reversed coil or coils. Locate with the aid of a compass and recon- nect correctly. 5. Faulty armature construction. Wires too small, eddy or Foucault cur- rents, hysteresis may be among the causes. 6. Insufficient ventilation, allowing armature to heat up unnecessarily, The Heating of Field Coils 1. Voltage at which machine jg operated may be much higher than it was designed to turn out or receive. 2. Fieid connections may be wrong. They may be in parallel when they were intended to be in series. A part of the field may be cut out by either a ground or improper connection of the wires in the coil. 3. Excessive field current. In the - case of a shunt or separately excited machine, the terminal voltage should be lowered to reduce the speed, or the resistance of the field can be increased by putting resistance in series. In a series machine, decrease the field cur- rent by means of a shunt or rewinding with coarser wire. 4. Moisture in the coils. Resistance of field circuit will be lower than nor- mal. Dry it out as in the case of the armature. , Heating of the Commutator and Brushes 1. Heat may be conveyed to the commutator from the other parts of the machine, namely, the armature or the bearings. 2. Sparking at the brushes. If the commutator Explorin fermingla eter Fig.2 : Testing for open Circuit in Armature with Ammeter heating is due to the sparking, in- vestigate for the cause. 3. Poor brush-holder contact. The holder should not be so tight that it will prevent full tension on the brushes for a good contact. 4. Brushes heated by excessive cur- rent. Brushes must fit. commutator and. be properly spaced. Use either

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MADE SIMPLE ‘fecunicalities: Simple, larger brushes or lower resistance brushes to remedy this trouble. Heating of Bearings 1. Excessive belt tension, which makes the pulley bearing the hottest. Reduce load so that the belt may be loosened and yet not slip on the pulley. 2. Insufficient or a poor grade of oil in the bearings. Only plenty of good, clean mineral oil should be used. 3. Mechanical faults, such as a failure of the oil rings to revolve with the shaft; dirt, grit, chips, or filings in the bearings; rough journal and bearing seats; a bent shaft; journals too tight in the bearings; bearings out of line; too much end play, due to im- proper leveling or no lateral shaft mo- tion; unequal air gap, caused by the armature being out of center of the poles. : Motor Runs .Too Fast . 1. A series motor races away when the current is too great. Series motors require constant regulation, if con- nected to a variable load; alight load causes a motor to speed up. 2. A shunt motor will run too fast if the field rheostat is not properly set, or if the proper current is not supplied to the.motor. In either the field rheo- stat adjustments should be made. 3. Light fields, grounds, and short circuits will allow the motor to speed up unless heavily loaded. 4. Improper connections, such as the field coils, may be in series instead of in parallel; part of the field winding may be connected so as to oppose the other part; the compound coils may be in opposition to the shunt coils. 5. Speed too high, and with all resistance in the circuit the voltage is still above normal. To remedy this, additional resistance must be inserted in the circuit, unless the speed can be cut down by some other means as, before mentioned. Motor Runs Too Slow 1. Excessive load on the motor. Reduce the load to the rated capacity or less. Locate and remedy any un- necessary friction or mechanical re- sistance. 2. Short-circuited windings in the armature. Test for cross-connections or short circuits, and, if such is found, rewind the armature to correct trouble. 3. Armature strikes or rubs on the pole pieces. Locate projecting coils, and after pressing them down into place secure them with tie-bands. Striking may be caused by the bearing placed out of line or the armature out of center of the pole pieces. 4. High brush resistance and fric- tion. Clean, reset, and fit the brushes to the. commutator. 5. Weak magnetic field, due to a broken circuit, short circuit, or the machine not properly wound.

ELECTRICITY and understandable. $1.00 P. 5 Souke Science Monthly, 225 W. 39th St., New York

6. Fields may be too strong. Fields 940 Popular Science Monthly designed for series connection may be connected in parallel, causing them to run hot. Motor Running in Wrong Direction 1. Runs backward, wrong direction. Reconnect correctly according to the diagram. If no diagram is available, reverse connections to the brushes or make other reversals until the direec- tion of rotation is correct. Try re- versing connections of fields or arma- tures. If both are reversed, it wil] have no effect. As long as the polarity of the fields and the armature remain .in the same relation to each other, the polarity of the supply circuit is im- material. 2. Multopolar motors can be re- versed by shifting the brushes so that the negative brushes take the place of the positive. 3. Two-phase motors are reversed by reversing the wires of one of the phases. 4, Three-phase motors are reversed by changing any two of the line wires. Noises 1. Armature out of balance. Should have been balanced before assembly. 2. Armature rubs or strikes the field poles. Locate the fault and remedy the trouble. Striking may be caused by projecting coils; bearings out of line or armature out of center of pole pieces. File out pole pieces where the armature rubs or strikes. 3. Noisy bearing. Grit or dirt in the bearings. Oil rings may not run properly. 4. Too much end play, allowing collar on the shaft to knock against the bearing housing. 5. Brushes hum or sing. Clean commutator thoroughly, and sand the brushes to fit the commutator with a firm, smooth, gentle pressure. 6. Flapping or slipping of the belt. Tighten the belt or reduce the load on the machine. ; Miscellaneous Troubles 1. Fuses blow at starting. This may be due to a fuse of too small rating, or to loose or dirty fuse clips; motor overloaded; motor armature stuck; starting resistance cut out too fast; short circuit in the armature or the field; grounded line; improper con- nections; or the field circuit may be open. 2. Heating of induction motors is generally due to one of the phases being open. It must be remembered that a three-phase motor will continue to run on one phase, but will not start single phase. If such a motor is over- loaded it will come to rest and burn out. 3. A short circuit may be caused by two grounds in a two-wire system, or by one ground in a three-wire system with grounded neutral. 4, Shocks obtained from touching the machine frames are always due either to static electricity or the

rtotase°o @ 3 © cf wo & OC.

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March, 1919 ding of some live part of the sys- tem on the frame of the machine. Static electricity is caused by the ~ pelting, and can be remedied by pro- viding an arrester. Grounding may be either to the shaft or to the machine frame. ~ General Care of Machines In general, the motor or dynamo, t and all control devices connected with its operation, should be kept properly cleaned. No dust, dirt, or copper or earbon dust should be permitted to ‘ accumulate, inasmuch as they will eventually cause insulation break- downs. Bearings should be kept clean and free from dust and dirt or grit and the oil should be renewed fre- quently. The brushes should be kept smooth and set, sanded to fit perfectly, the curve of the commutator, to elimin- ate sparking and consequent pitting and scratching of the commutator. Battery (Source of !ow-voltage) ‘alk Voltmeter OT) i Exploring onald : Fig.3 Testing an open-circuited armature with a voltmeter The foregoing gives briefly some of the more important points that will undoubtedly prove of value in the care and operation of direct-current motors and dynamos. Alternating- current machines do not require as close attention as direct-current ma- chines, because the commutator of the latter is the chief source of trouble. Only the more important and common faults and troubles arising in connec- tion with direct-current machinery are eae given, the less common and less fre- | _ quent troubles being found and en- countered on complicated systems of wiring and special designs of ma- é' _ chines. The present article is the concluding one of the series dealing with electrical devices and the principles involved in ; their operation. Means and methods , x of locating and repairing faults and ‘ troubles inherent in direct-current ) electrical machinery will be readily . apparent upon reference to any stand- 4 _ ard electrical hand-book. By follow- ing explicitly the procedures given, , troubles can be eliminated at once, . and at the same time preventative 1 measures will suggest themselves as one becomes familiar with the operat- "4 ing characteristics of the machine e : i question. e ‘ [THE ENp] *Automatic Gp Feed Stakes care of : GEmall Drills, Too An automatic feed that takes the place of human skill and sense of touch! The mechanic is hand-feeding a deli- cate drill in tough material. A ticklish job! The slightest over-feed—sometimes only the twitch of a muscle, and— Snap! The drill is gone. The Automatic Friction and Ratchet Feed of the “YANKEE” Bench Drill would feed the same drill through the same cut without variation of pressure or sudden strain; without even requiring special attention from the operator. Just place your work and turn the crank. The Friction Feed runs the drill rapidly down to contact. Saves time! Then the Ratchet Feed takes hold and gives you an absolutely uniform feed pressure throughout the cut. Saves drills. “UIAAAAYYY Kc Feed-shifter at top of spindle; Speed Shifter between small bevel gears. Both shown in illustration, “YANKEE” Bench Duill 1005. Tw ds, 3-jaw chuck, holds drills Note tin. Height 28 in, Price (Philadelphia) $19.25 $11.50 No. 1003. 3-jaw chuck, holds drills up to 4% in. Height 1834 in. Price (Philadelphia) “YANKEE” Vise No. 990 Accurately machined sides, ends and bottom, for holding work on Bench Drills and other machine tools. Swivel-jaw for taper work; groove for rounds. Base % in. long, 236 in ‘wide... Pri€e.. 02. kveaa 3% $2.50 Your Dealer Can Supply You Write for Free “YANKEE” Tool Book illustrat- cana et ing “YANKEE” Tools in action, and easier ways of drilling, boring, ‘tapping, and driving screws. NORTH BROS. MFG..CO. PHILADELPHIA. wal 7 QNake. Beiion) Mec an wew, 93!

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Be independent of train service. Blazenew trails. Let fancy guide you over the lanes and side roads, far from the beaten track. There is the real springtime that is yours and your pal’s as you skim along on your Harley-Davidson Just as it was the mount of the Yanks and the Allies, so it is the mount of every red-blooded outdoor man who’ appreciates readiness to go anywhere, any time. Let your dealer show you the motor- cycle that is being talked about. HARLEY-DAVIDSON MOTOR CO. MILWAUKEE, WISCONSIN SAVE 25% to 60% on slightly used " e no chances deali ithus. We h been in the to- gregbe be pees over ie years. Write nowe CENTRAL CAMERA CO. Dept. 53, 124 S$. Wabash Ave., CHICAGO FREE -“LNTSXS ar but eeponse. « Btate size wanted on postal REVERSIBLE COLLAR CO., Dept. A Boston, Mass. | Popular Science Monthly : A’ Quick Way of Bushing Tight Pulleys HE illustration shows a ve T method of bushing a ulleg = any desired size. Suppose we have a pulley with a 2-in. hole that is needed in a hurry for a 15/16-in shaft. ° Place the pulley, edge down, on the table of a planer or any other flat machine surface; then, with a short piece of 15/16-in. shaft having one end square with its length or a trifle con- cave, proceed to place it centrally in the hole of the pulley. This may be done by carefully measuring with a steel rule. When set, place a weight on top. It SHORT LENGTH OF SHAFTING BABBITT: SS sn VIM), mein: | Z H SSH “N Uj Yb y A practical method of bushing quickly LA is then ready for filling the space with whatever material is at hand—lead, old babbitt, or type metal. If the shaft has been coated with black or red lead it should pull out of the new bushing by hand, and the latter be ready for use on the regular shaft without scraping or reaming. In the illustration the set screw will be seen extending through the space to be filled with babbitt up to the shaft. By coating this screw with lead and- setting it as shown, threads will be formed in the new bushing. With ordinary care a 24-in. pulley that is so bushed should run true within 1/32 in.—DONALD A. HAMPSON. 7 A Home-Made Sight Oiler for a Bearing HE arrangement illustrated was attached to all bearings in hangers of a large plant, and it assured the oiler that there was a supply of oil in the lower chamber. Each oiler consists * of a 3%-in. gas- pipe fitted as shown with a 2-in. length of ordinary gage glass cemented with _ plaster- H of-Paris in the ell. The oil in Re er the glass tube An inside view of 2 the oil-gage as it will will always show the level of the oil in the reservoir. The bearing can be oiled from the opening at the top of*the glass gage.—THEODORE J. BECKER. appear when finished ] “ a

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‘Msgr . L, hy /, LLT/ he on YALL EF, YY ith fy LEAD > Eee Ae Wi “Witte cerzzes a ia ul ad, KM s RG: ith ; of the * ; le d-Spring-Mattress vill Keep the complete outfit and use it.forthirty days. Setit up and sleep in it, Treat it just the same as if you owned it. After a month, if you wish to return it, no exe ace / vianations or apologies are necessary, on he Send Only One Dollar Into the top and lower Paleo sine rods are set / Enclose this small deposit in a plain letter. Stands 684 in. at head end and 37% in, at foot, Fs eide that the outtt is not Wanted, this ting Colors [fr°,, "bite or popular all gold Vernis are — 4 returned to ycu immediate Y; also Pa Splendial de, oh |: | cre at atti pape nS Guaranteed Spring 2 twu ta ites t e Way With Everythin bands, Fastened to angle steel f, ith 27 coil at This bargain is simply one Seanatenn 000 dis- springs. Fits bed, '@° te! frame wi - jaye - i 2 i Y po bieger value than all these tan Boe: His Restwell Mattress ¥o13,comfortable and ex- simply as an example of our raving Prices, our splendid hest combed excelsior, overlaid with clean, fine cote “ y Selections, and the easiness of ordering and Paying. ton on top and sides closely tufted and firmly stitched, | OW. Sturdy Steel Bed Ser Sinieldsic mpsp- Bo rade tating. “Gracesy 1 ° ; ‘ Standard’ full size, measuring 4 ft. 6 in. wide.’ The No. RB6179. spring eae ent ted $19.95 Book of 8000 F it Bargains F Credit With Aski 4 & a -reait Without Asking=Take a Year to Pay a: Send for our newest and biggest book, and judge its display {he aug “hyve,tave told you about the outit on le simply for value, quality and beauty. Think about the credit part only as an ha ha Mrelghbes, "ever write your il extra advantage. About 8000 articles are pictured and described, Everything is {tignds, employers or neig gis yy Shown big—no eye straining over little ‘ h pictures, Many things like carpets, Pay Little by Little As Free Loan Answers All rugs, li : i i » and | their eal colors” "Pre ® =| You Get Your Money When you have our nk, and ay dott o real Colors, Credit won the War. Itcan just as well bring Sider eur free Joan. That t takes care of everything, = Nothi for the h is left out you now the comforts and blessinigsof Peace, Never It takes away from you any chance of being disap- ing for the home is left out or again will any intelligent person talk against buy; pointed—any risk of the slightest loss, 8 forgotten. You can get a wringer or stew pan sain, will on crevit. Liberty bonds as well.asRed We couldn't afford tn mislead you in the ~ the same as a utiful davenport—or Cross pledg es were paid for just that way.’ In the slightest degree, and send things on tree loan for a a andsome silverware. It is so different from _ future real people will brag about thein credit, and month. When you send things back, the trial has f the ordinary run of catalogs, that you will just the fact that they are trusted, hot cost you @yen a penny. So you see, it is our 7 love to look it through. It is twice the usual © When we send you our big bargain book,a object to satisfp you even more completely than we D size, covering 11 x 15 inches, It costs us with credit certificate Will come with itopening your ac- Bromise, f the mailing, about $1.00 a copy. To you it is You won't aye aan seek rerrectly at bome bere. Some of Our Big Departments free. All you have to do is ask for it. arranged all that in adecnea oe. ve Furniture Rugs Ranges - Stoves Carpet Even if you do not need anything right When vou ness anything just tellustosend it Carpets Draperies Sewing Machines Sweepers , away, get it and have it handy. Use Giarwate Conta J — it to compare prices — if nothing © — — Wat =, jag - ever where Petore ps holes Wringers uy. If you finally decide on : o on consider the extra ad- e ° ern O. i ge Toca ina ntages we offer you, ; —— : yx y Mail Request Today Sure <e

1203 West 35th Street, Chicago

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How to find the right pencil You have run across a pencil now . and then that suits you to a T—makes your work easier, quicker, more satis-. factory. Why not be sure of getting sucha pencil every time? yxy DIXON'S. | ELDorAD( the master drawing pencil” has strong, firm leads that save a lot of resharpening ~ —smooth, responsive leads that write with much less effort. Made in 17 degrees —6B (softest) to 9H (hard- est). HB (medium) is most popular for general work ; but be sure to get the degree exactly suited to your work. How to find your grade. With the aid of the chart below, select the grade you think you should have. If the first is not exactly right, mext time select a degree or two softer or harder as the case may be. When you have found your degree, specify it every time and you will beassured of satisfaction from thenon. rite us which degree you want,or what ‘ kindcf pencil work you do, enclosing 16 cents in stamps and we will send you fuil- length worth double the money. JOSEPH DIXON CRUCIBLE CO. DEPT. 120-J JERSEY CITY, N. J. : 3 . . - Representatives 1827 A.R. MacDougall & Co., Ltd., Toronto, Ont. 6B) Varying degrees of H Hard. sb lex softness —6B 2H Harder. 4B ) softest. 3H Very hard. 3B Extra soft and bla-k. 4H Extra hard. 2B Very soft and black. SH inj B Soft and black. 7H Pei F HB Medium soft. 8H (,, — BE Ficm gH ) bardness. effects at dances and recep- ———$———— Buy parts and make your own sets. Large stock of Radio ma- terials left on our hands because of canceled Government contracts! An Opportunity for Buying High Grade Materials at Bargain Prices | Guaranteed Galena Crystals, every- thing for Coils, Switches, Knobs, Resistances — Insulating Materials, |. Condenser Plates and Parts, Litzen- draht and Magnet Wires, Contact Points, Head Pands. De Forest Radio Tel. & Tel. Co. 1391 Sedgwick Avenue, New York City RADIO AMATEURS! A Spot-Light for Amateur Theatricals Make One for Your Dramatic Club By Raymond Francis Yates Front of the lanterns with the revolving disk attached for the colored lights HE spot-light de- scribed as follows is of simple construction, and makes an ideal machine for the local dramatic club, or to produce moonlight tions. In fact, an alert builder could easily make the lamp pay for itself by The base which encloses the rheostat and the switch to control the current Two small wood circles are then cut to form the top and bottom of the compartment at the base of the machine, which in- closes the resistance coils ‘ and the electric light. As shown, the compartment is built around the stand- ard, and it will be neces- renting the machine. The lamp-house is made first. Itis cut from No. 22 gage galvanized iron in a single piece, as shown. The dotted lines indicate where the iron is to be bent. After bending into the prop- er shape, the house should be riveted ‘together with -in. copper rivets. It is, of course, understood that both the hold for the lens and the large opening on the side for the door are cut before the lamp-house is bent into shape. A %-in. pipe flange is bolted to the side of the lamp-house to accommodate the iron pipe that holds it. A piece of 1-in. iron pipe is used to form the stand- The lantern complete mounted on its base ard of the ma- chine. To the lower’end of this is fixed a heavy wood base made of two thick- nesses of 1)4-in. i. 5 EDGE FOR RIVETING plank, glued to- |\ | gether with the ht grain crossing. Es Unless the build- y er is provided sf with the proper tools for making this circular wood base, it should be ordered from a mill where the work can be done. The base should be made large enough and with sufficient weight so that the machine will not be topheavy. 98 pa th ae oe el 14 Patterns for cutting the metal to make the lamp-house. “When bent to the proper shape one piece makes the entire box sary to drill a hole in the center of each of the circles so that they will fit snugly on the 1-in. iron pipe stand- ard. After the resistance coils and the lamp are in place, two pieces of galvan- ized iron and two pieces of wire screen are tacked to the wood blocks. The wire screen is used to insure good ventila- tion, since the resistance coils generate considerable heat. Two lengths of 3¢-in. iron pipe, two els, and a tee-joint are then assembled to form the angle that supports the lamp-house on the standard. This’ is shown in the sketch. The el on the upper end of the angle is fitted with a short length of pipe connecting with the flange previously bolted to the side of the lamp-house. A swivel - joint is then made be- tween the iron standard and the iron pipe angle, so that the lamp- house may be turned. A 4-in. single- convex lens is mounted between two pieces of galvan- ized iron, asshown. Two groovesare then bent from sheet iron and riveted to the front of the lamp, so that the frame in which the lens is mounted will slide in Door OPENING | ‘ 2 T 6 Popular Science Monthy," aAamretrrawawaonnwutwtsa ee SE ——— LT lll!

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nt rcles | the the n in- coils nent and- CeS- the rcles ugly and- the van- reen tila- rate two pled the This * the vith h of ting nge lted the iron the gle, mp- be gle- an- hen the 2 in "March, 1919 - . them. If the builder is unable to obtain a tacked in place as previously explained. gingle-convex lens of this size, a smaller one can be used, or a piece of ordinary glass can be fitted to the front, al- though this would decrease the range of the machine. When the vent-holes in the top of the lamp house are fitted with iron strips, so placed on the inside asto prevent the escape of light and yet to permit free circulation of air, the machine is ready for the electric fix- 4 ‘ [TWO PIECES RIVETED TOGETHER PAN | id 3 ~ ow vw RESISTANCE. COILS - {he lens or condenser mounting and the wiring diagram for the current The are light and its mechanism will be considered first. This is sim- plicity itself, being formed of two brass arms, joined at one end with a screw and with the carbon holder at the other, and provided with ea spring, which pulls them together. The regulation of the arc is effected by means of a metal wedge, which forces the brass arms apart or permits the spring to pull them together, depending on which way it is moved. ’ ; The are mechanism is shown in the sketch. It will be noticed that no dimensions are given, since a general description will enable the builder to make it with the materials and facili- ties at hand. The whole are mech- anism is mounted on a fiber base equip- ‘ped with four feet, which are provided with a hole so that the base can be METHOD OF FASTENING ADUSTING ROD TO WEDGE. MICA INSULATED THREADED : ADJUSTING ROD \ LENS Mechanical arrangement for control- ling the carbons to bring the space to an arc as the carbons are burning made to slide on two steel rods run- ning the length of the lamp house. This arrangement is made to focus the light. Two small resistance coils are wound on asbestos strips and mounted on the compartment at the base of the lamp. A socket and carbon filament lamp is also placed in the compartment, and, after the proper connections are made, the sheet iron and the wire screens are On the Jo - * —when you want to think hard and straight—the famil- iar feel of your favorite pipe and haze of good to- bacco smoke seem to cut you off from the rest of the world and let your mind work the way it should. The pipe that never in- terrupts, nor takes your - mind off your work, is the . The W. D. C. triangle trade- mark has been the sign of su- preme pipe value for more than every Wellington,: but also: on- - other pipes that’ we make of all moisture and loose tobacco crumbs. The smoke comes, quiet and cool and sweet as a night breeze, and it comes up, away from your tongue, through the top opening in the bit. every style, size and grade. Price for price, grade for grade, there is no better pipe made than aW. D.C. You will like your Wellington from the very first. Y UNI PIPE VERSAL As you smoke your Wellington there's never a bubble nor a gurgle. O years. It is not only on:.: The well attends to that by catching It is always made of genuine French briar, seasoned by our own special process, so as to break in sweet and mellow. And it’s a good old reliable friend— guaranteed against cracking or burning through. Get a Wellington Pipe. It will fit into your life in a mighty agreeable way. It has fitted into more men’s lives than any other pipe. Good dealers have it in all sizes, shapes and grades from 75 cents up. Just be sure the one you get is marked W. D.C. Wellington. WnmM.DEMUTH & CO., NEW YORK WORLD'S LARGEST MAKERS OF FINE PIPES 10 Cents a Day Pays for This Symphonola Plays all records, Victor, Columbia, Edison, Pathe, Little Wonder. Emerson. Take a year to pay, after 30 days’ trial. Compare its tone for clearness, volume with more costly instruments. Return at our expense if it fails to make yoo’. Ask today for the Beautifully Ilustrated Symphonola Book FREE. Shows this and other Symphonola styles sold on easy payments. s MPHONOLA RECORDS—Get our list of the latest song, dance, popular, clear sounding, full toned disc records. Playable on any Phonograph. Leatthitt - Co Desk SPSM-319 Buffalo, N. Y. 99 MAKE YOUR BIKE A MOTORCYCLES at asmall cost, by using our attachable outfit. Fits any Bicycle. Easily at- tached. No special tools required. : **Used His Four Years’’ Harry A. Hyatt, of Boreas River, New York, writes: ‘“‘About four years ago I recetved my motor attachment, and wish to say that I am. satisfied with in every way, for it has certainly given me good service. Anyone wanting a motorcycle or attachment, I would rec- ommend t to the Shaw Manufacel- uring Co.” FREE B00 Write Sede for bargain list and free booklet. fully describing the SHAW Bicycle Motor At- tachment. Motorcycles all makes, new and second-hand, $35.00 up. -SHAW MANUFACTURING CO. Dept. 169 GALESBURG, KANSAS

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——— — Se = ce — 6 RIT aS Fen ths Rie be me a ESR. Sn = oo Se GR ‘e) to School at Ho Ih : : Se, tn iG / ares 2) see * Se eee HIGH SCHOOL [I COURSE IN ‘TWO YEARS YOU ARE BADLY if you lack HANDICAPPED [12"School You cannot attain business or social prominence. You are barred from a successful business career, from the. leading professions, from well- paid civil service jobs, from teaching and college entrance. In fact, em- ployers of practically all worth-while positions demand High School train- ing. You can’t hope to succeed in the face of this handicap. But you can remove it. Let the American School help you. FIT YOURSELF FOR A BIG FUTURE 75's Course, by some of America’s leading essors, will broad-n your mind, and make you keen, alert and capable. It is complete, simplified and up-to-date. It covers all sub- jects given in a resident school and meets all vequirements of a High School training, From the first lesson to the last you are y examined and coached. USE SPARE TIME ONLY Most people idle away fifty hours a week, Probably you do. Use only one-fifth of your wasted hours for study and you can remove your present handicap within two . You we oniey the lessons and the knowledge _ 1 gain will well repay the time spent TAKE 10 LESSONS So that you may see for P REE yourself how thorough ; lete our traine and is. invit to take tox lessons ia the High School Course Fe ey Course of epectalized trsining in the Electrical E ..Slee. Light & Power Supt, ....Certified Pub. Accountant «Business Manager «Hydroelectric Engineer ....Accountant and Auditor ....Lelephone Engineer «Bookkeeper +k Clegraph Engineer o-Stenographer +». Wireless Operator «Mire Insurance Expert +++ Arehitect «Sanitary Engineer .»..Building Contractor «Master Plumber Civil Engineer Heating and Vent. Engineer Structural Engineer ...Automobile Engineer ---wMlechanical Engineer «Automobile Repairman Steam Engineer «General Education Course - aS mounted on its base The wires from the coils and lamp are brought through porcelain insula- tors and formed into a single cable ‘by winding friction tape around them. This cable terminates in a small junc- tion box which contains a fuse connect- ed .in series with -the arc, and.a small LENS ELBOW single-pole switch is mounted on the cover. The fuse is also. shunted across the lamp in the compart- ' SWIVEL ment at the base. When the fuse -blows, the lamp can capLe be used to pro- vide a light to . _make repairs by bringing the carbons. to- caBLe | |RONPIPE gether and connecting the lamp in the circuit. In case the resis- tance burns out in operation, an external re- _ sistance can be E {y= used by discon- 4 | nectingthe coils Elevation of the lamp Apogee ~ switch mounted on top of the housing for the resistance coils. When the arc is started, both coils should be in the circuit, and to bring the lamp to full brilliancy one coil should be short-circuited after the arc is struck. The method of connecting the elec- trical apparatusisshowninthediagram. The arc is connected to the junction box by a cord that runs through a fiber bushing in the lamp house. An ordinary lamp-cord and plug com- plete the elec- trical equip- ment of the machine. The ma- chine is made complete by the addition JUNCTION Box II vu r . g D> 4 18) my an is] RESISTANCE J COILS & may a ws of a color wheel made of galvanized iron and pro- Diagram of the circular yjged with disk forthecoloredlights ¢ 01» holes ‘each 4 in. in diameter. Squares of colored glass are placed over the holes and fastened tothe back of the wheel by means of single strips into which they slide. A shaft is fixed to the center of the wheel, which fits into small bearings on the lamp house so that the color wheel can be made to revolve in front of the lens at the desired rate. If it is desired to spread the light, the arc-lamp carriage should be moved to the front of the lamp house, and if 100 should be moved to the back of the lamp house. In spreading the beam _by moving the are forward, it should be remembered that it is quite possible to break the lens by excessive heat: therefore the arc should not be brought too close to the lens. A limit should be provided for the movement by ar- ranging an object on one of the rodg on which the carriage slides. Locating an Invisible Error in an Alternating-Current Motor HILE working in a power plant in a small town, the writer wag. called to reconnect a three-phase four- ,pole series star-connected motor so that ‘it would operate at different voltages. Changes were made according to blue-' prints, but when the motor was tested: it operated at one-third normal speed. To locate the trouble, the star con- nection was opened and opposite ends of each phase joined to the terminals of a storage battery. By testing the poles of the armature with a small pocket compass while the current was flowing as stated, it was found that the poles of each phase were symmetrically placed around the armature, and that they were alternately marked S, N, ete. Next, the star connection was joined again and the current allowed to flow in two leads and out the third. Under this condition, and with a properly connected three-phase four-pole motor, the polarity of three consecutive poles should be in one direction, while that of the next three should be opposite, etc., thereby forming four flights of alternately different polarities. In this motor, however, it was found that the adjacent pole faces of different ? N- R One group yy “TF of coil ends » O° Fig.t Fig2 The trouble was that adjacent pole faces of different phases had opposite polarities phases had opposite polarities, in- dicating that one phase was removed. To determine which was reversed, all of the leads were connected with the positive terminal of the storage bat- tery, while the star connection was joined with the negative terminal. As shown in Fig. 2, the polarities fell in three flights ‘of opposite values. Ina. properly connected armature polarities. of adjacent poles should be opposite. Since the only polarities that could be reversed to bring about this arrangement were those corres- ponding to phase B, it indicated that this phase had been reversed; that is, the terminal that should have been. a lead was connected to the star points,; and vice versa —MAURICE M. CLEMENT... Popular Science Monthly . a concentrated beam is desired jt tric: and havi

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~~ ae GS ee RE — Pv pee wf cru Ww ra 2 * NN Or ww OE or cr = FP 3 ee Sr we wee | \ "March, 1919 - A Fiber Conduit Used as a Drain-Pipe HE ordinary fiber conduit used a py electricians for insulating elec- tric wires may be converted into drain- and leader-pipes by using conduits having walls 14 in. thick and the 34- A joint made in an ordinary conduit pipe so that it may be used for a drain-pipe in. tenon joint, as shown. ‘This joint permits one section to slip over the next, making a very tight joint. These connections may be made doubly se- cure by the use of waterproof cement. A leader hook is used to secure the fiber leader-pipe to the wall, as well as to keep it away from the wall. A fiber leader-pipe may be made of wood fiber, saturated with a special waterproof material, and, as there is no metal in it, the leader cannot rust. In the present scarcity of metal, this substance is a good substitute, and, as it cannot rust and will not rot, it ought to last for an indefinite period. Then, too, the pipe may be laid in the ground the same as a tile and it will still have its lasting qualities. In laying the pipe the joints should be protected to keep them from breaking.—LovuIs CUMMINGS. A Scldering Acid Receptacle with a Brush Spout OLDERING acid may be con- veniently applied by means of the combined can and brush shown in the illustra- tion. An ordi- hary copper can about 214 in. long by 11% in. in diameter is used, and it is provided with a neck made from a piece of 3/16- in. coppertubing. Into this tube some paint-brush bristles are in- serted, being made fast by flattening the neck. . The de- gree of this flattening deter- mines the flow of the acid and a very delicate adjustment can be made by this means. There is a filler plug in the top of the can, so that more acid can. be added.— ERNEST SCHWARTZ. A copper can with a brush nozzle DON'T BE A WALL FLOWER! Learn To Play By Note Plano, Organ. Violin, Cornet, Mandolin njo "Cello, iecolo, ‘Trombone,. Clarinet, Flute, Harp, Sight Singing, Harmony and Com- eS ’ L teel Guitar, Tenor Banjo, Viola, Ukulele, Saxophone. LEARN MUSIC AT HOME No longer need the ability to play music be shut our of your life! Now at last you can learn music—how to play any instrument— at home—yet without having a teacher at your elbow. By our wonderful home study method we have made it easy for you to play by note the Piano, Organ, Violin, Banjo, Mandolin, Guitar, Cor- net, Piccolo, Trombone, Clarinet, Flute, Harp, Harmony and Com- position, Hawaiian Steel Guitar, Tenor Banjo, Viola, Saxophone, Ukulele, ’Cello, or learn Sight Singing. No Tiresome, “‘dry”’ exercises, no inconvenience, no trick music, no “numbers,” yet simple, wonderful, easy for even a child. Now you can bring into your own life and the lives of others endless pleasure and happiness through your music. Instead of being a torsaken “‘wall flower’? you will be the most popular person in your set. By our new plan more than 200,000 gentlemen, ladies and children in all parts of the world have learned to play successfully and skillfully. WONDERFUL LESSONS FREE We want to have one pupil in each locality AT ONCE to help advertise our wonderful, easy system of teaching music. For a limited time we are therefore making a special advertising offer to give you music les- sons in your own home, absolutely free. The ONLY cost is for postage and sheet music, which averages a small amount weekly. We can do this because our course makes friends—pupils recommend it to others and then we make our profit. We make this offer on condition that you give them our name when they ask you. Send No Money ™*",couro" Learning music successfully by our Home Study method is a positive, proven fact. The lessons are so interesting it is more like a game than astudy. Thousands who never knew one note from another before taking the lessons have developed into expert musicians. . The average yearly enrollment for the past few years has been over 25,000 pupils. We grade you before you start and fit the instruction to your special needg A beginner gets entirely different lessons than one ig a = gym Let us send you our new 24-page book, whic e- @ scribes the secret principles of our wonderful New » FREE Cou PON System of Music Teaching from beginning to FOR LESSONS end, and contains scores of letters from pupils who U. S. School of Music, 83 Brunswick Bidg., New York have become expert players as a result of the @ Please send me your (ree book, ““Music Lessons Course. Write to-day. Mail coupon or postal. @ 2% Mall exlaining how t can learnt oly any Instruments supplied when needed, cash or credit. 2 Py inateument ss... cccssiecveete wovcctwessate ene’ U. S. School of Music a N@ERG . . c cccccccccces 5006 sees oe 6slhce uae 83 Brunswick Bldg. New York of a sacccs 101 TOPO OH HOH OEE HEE OEE EEE EEE HEE HEHE EEE

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featan Home from the Canadian Pacific HE Canadian Pacific Rail- way offers you the most wonderful opportunity. in the world to own a farm in West- ern Canada. It will sell you land for $11 to $30 an acre or $50 an acre under irrigation. 20 Years to Pay You pay down 10% of the purchase price and have twenty years to pay in full at 6% interest. $2,000 Loan to Farmers The Canadian Pacific Railway will loan to approved settlers on - its irrigated lands up to $2,000 in improvements with twenty years to pay back the loan at 6% interest. Land Under Irrigation In .Southern Alberta, we have developed the largest irrigation undertaking on the Continent. This district consists of some of the best land in Western Canada. An unfailing water supply is ad- ° ministered under direction of the Canadian Government—no. con- flict of law or authority over its use. This land is offered on same easy- mt terms as other lands. ces ranging up to $50 an acre. This Is Your Opportunity To make investigation easy, spec- = ial railway rates have been ar- & ranged. Write for particulars and =} free illustrated booklets. M. E. THORNTON Supt. of Colonization : Canadian Pacific Railway i@ 925 First St., E., he Coleen Alberta && THapaisusUseiGaneNOOCEPROGHEOELUSUERENUOUAVUCLACINOORTDUEEEREDiDIUGEEOUUOUOEUSDOONUSTUUIDEOUINUEEDINUVUDETEVONEEUTURTELTE MUM TM WM = POUNARUOECEUOUDEOEOOOUREECDOEDNOEEEDOEEOEGEIELEDSE eee LAMP OR OR = Remedy aoo-canous seers pg siempe Al ee open territory. AKRON GAS LAMP CO. 483 GAS BLDG. AKRON, OHIO Popular Science Monthly What Did You Do with Your Old Car?’ $300 in Prizes for Ideas ae GEAR anan thousands of old-automobiles wha had been cast into the discard as too old and too in- complete for satisfactory service were seen on the streets during the last six months of 1918, and many are still merrily chugging their way over our thoroughfares, each giving some service to mankind which is better than no service at all. Automobile authorities estimate that it will be at least nine months before all of the factories are turning out cars at their before-the-war rate. Many remarkable transformations were made in old cars called out of retirement. Here was an old-timer with a chariot-type body fitted with an ingenious kind of closed body for winter use; there, a new carbureter which brought the miles per gallon up from five or six. to nine or ten. Many of the improvements and adaptations are important and practicable enough to warrant their being continued. It is in this belief that the POPULAR SCIENCE MONTHLY has decided to offer the substantial total of $300 in prizes for the three best methods of enabling the old passenger automobile to continue in service until, like the one-horse shay, it falls to pieces in its every part. ; Rules of the Contest OnE—The utilization of the old ‘passenger car may roughly be divided into two main classifications: a—The continued use. of the vehicle as a mode of transportation; and, b— The use of the vehicle to perform some function in a better manner, in less time and more cheaply than the same function can be performed by hand. Two—lIn determining upon the prize- winners, the judges will pass on each clas- sification. as of equal importance and will make the awards in the order in which the utilization or adaptation is of the most value or the greatest good to the largest number of people, no matter whether such utilization or adaptation be a mode of transportation or mode of power application. THREE—The utilization or adaptation submitted for consideration need not have been in actual use, although if it has been put into actual use it will receive the preference as a deciding factor, when, in the opinion of the judges, two or more utiliza- tions or adaptations are of equal value or good to the greatest number of people in all other respects. Four—Contestants are not limited in the number of utilizations oradaptations they may submit. However, only one can win the first prize, one the second prize, and one the third prize. The contest is open to everyone. FivE—The utilization or adaptation sub- mitted must be clearly shown in one or more drawings, or photographs with explanatory drawings, if necessary to bring out the method of arrangement or construction. The drawings must be intelligible, although it is not necessary that they be made by a skilled draftsman. Contestants are re- quested to make any drawings submitted in ink on stiff board rather than in pencil on writing paper. In each instance, the draw- ings should be as large as may be necessary to convey the idea clearly. Srx—The contestant’s name and address should appear on each drawing submitted. Each drawing or set of drawings on any one idea must be accompanied by a description in which the utilization or adaptation is clearly indicated. This description (preferably typewritten) must be written:on one side of the paper. The name and address of the contestant must appear in the upper left corner of the first sheet of the written de- scription. 102 SEVEN—The description and drawings submitted by any contestant must be re- ceived in the office of the PopULAR SCIENCE MONTHLY not later than 12 o'clock noon, Saturday, March 1, 1919. All contributions received after 12 o’clock noon on March 1, 1919, will not be considered in awarding the ...."..* will be returned to the contestant if return postage is sent. E1cHT—A first prize of $150 will be award- ed to the contestant who, in the opinion of the judges, has submitted the utilization or adaptation of an old passenger automobile which is of the greatest value or good to the largest number of people. A second prize of $100 will be awarded to the contestant who submits the utilization or adaptation next in the order of merit. A third prize of $50 will be awarded to the contestant who submits the utilization or adaptation which ranks third in merit. NINE—The winners of the prizes will be announced -in the May, 1919, issue of the POPULAR SCIENCE MONTHLY. TEN—The description and illustration of the utilization or adaptation which wins the first prize will be published in the May issue of the POPULAR SCIENCE MONTHLY, together with the name and address of the winner. Similarly, the second and third prize uses will be published in the June and July issues respectively together. with the names and addresses of those winners. ELEVEN—The judges of the contest will be the editors of PopULAR SCIENCE MONTHLY, TWELVE—The editors of the POPULAR ScrENCE MONTHLY shall have the right to publish at regular space rates descriptions of utilizations or adaptations which do not win any of the prizes but which they consider of sufficient interest for publication. THIRTEEN—The full property rights in any utilization or adaptation submitted are re- tained by the contestant, the only restric- tion imposed being that defined in Rule 12. FourTEEN—TIf a contestant submits more than one utilization or adaptation, each must be sent as a separate unit. FifTEEN—Address the descriptions and drawings submitted to the Motor Contest Editor, PopuLar ScrENCE MONTHLY, 225 West Thirty-ninth Street, New Vork City.

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March, 1919

Emanuel SWEDENBORG’S BOOKS at a nominal price—Sc

r all of the following four vol- Boor) be sent, prepaid, to any address on receipt of 5 cents per book: “Heaven and Hell” 624 Pages “Divine Providence” 605 “ “Four Leading Doctrines” 593 “ “Divine Loveand Wisdom” 598 “ ch book is printed in large type on fos paper, and is substantially bound in stiff paper cover. Endowed for that purpose, this Society offers to send you these books without cost or obligation other than 5 cents each for mailing. Address all orders to Room 755 The American Swedenborg Printing and Publ'shing Society 3 West 29th Street New York

——_> oa _ They don't call him. “SKINNY any more

Why is it that you stay thin? Do you know? How often have you wished that you could cover the bones that show so plainly all over your body—to feel the thrill of that vitalizing energy that comes from a fully de- veloped body tingling with health! You can have it! It will make a new man of you—full of energy. ambition, and the joy of living. And the beauty of it all is that this precious gift will cost you nothing! You have it in the palm of your hands right now! Start NOW and in less than a month you will be well on the way to physical perfe tion.

How to Make-a’ New’ Man of Yourself **How to Gain Weight’? is the title of a book written hy Bernarr Macfad- den, founder of ‘*Physical Cul- ture’? magazine. It goes to very core of the subject and tells you how to gain weight easily and natvrally, without the aid of medicine. To thos N send us a three month subscription for ‘‘Physical Culture,*’ mos' unique, helpful and ins irational f fein oh - He kind pu! aiahed ay ' America, at the regular price of §} will send this valuable @ book FRE: 119W.40th St.. Suite 801,NewYork “DON’T SHOUT” “I ran | hear now as well nnn cashody. ‘How? With THE MORLEY PHONE. I’ve a pair in my ears now, but they are invisible. I would not know I had them in, myeelf, ‘only that I hear all right. “The Morley Phone for the

is to the ears what glasses are to the eyes. Invisible, comfortable, weight- less and harmless. Any- can adjust it.” Over one one hundred thousand sold. Write for booklet and testimonials, THE MORLEY CO.., Dept. 797, Perry Bldg., Phila. =. AGENTS: $10.00 a Day 2 in 1 Reversible Raincoat Somethingnew. Notsoldinstores. Heavy, warm, positively guaranteed water-proof. One wm side a handsome black raincoat, reverse side a ine dress coat. Takes the place of an expensive Overcoat. Elegant style. For business men, Clerks, farmers, teamsters, truck drivers. Every Man a Prospect Everybody pleased. Binford sold 26 coats in Sdays, Don’t fail to get this big money maker quick. Right now is the season for this new, big seller Be first in your-territory to introduce this reversible coat and our new line of fancy Quaranteed raincoats. Send at once for our offer and sample. THOMAS RAINCOAT CO. 847 Jane St. Dayton, Ohio LEARN TELEGRAPHY

at home in shortest possible time, Morse | or Wireless. OMNIGRAPH AUTO- MATIC TRANSMITTER, connected with Sounder or Buzzer, sends you messages at any speed, just as ex- R's operator would. Adopted by . 8. Govt. 6 styles. Catalog free. OMNIGRAPH MFG. CO. 9-H Cortlandt St., New vork

i$ How to Make a Small Variable Condenser HE condenser shown in the sketch herewith combines the capacity of a fixed condenser with the grad- ual capacity variation of a variable one. It is suitable for a wireless receiving circuit, or to shunt around a vibrator of an induction coil, by making the units considerably larger. ~ It is made up of several fixed con- densers connected in parallel, a lever being the means whereby the capacity is varied. Five or more units may be used, each being a small condenser built up of ten sheets of waxed paper and nine sheets of tinfoil. A conve- nient size for the tinfoil is 6 by 4 in., and for the paper 544 by 44% in. The latter should be a good grade of thin linen paper, and should be very care- fully dipped in paraffin. The sheets of the tinfoil and the paper in each unit are piled up alternately, allowing about 14 in. on each tinfoil strip to pro-

SS “SSS Waxed paper sfxak ~ Tinfoil. strip ¢ s - “SAT

Method of assembling unit condenser Several fixed condensers connected in parallel and arranged to be variable ject beyond the paper for connections, as shown. The pile is covered with heavy paper, and a heated flat-iron is passed over the top of each unit’ until the paraffin begins to melt. Upon cooling, the units become compact. The connections necessary are shown in the sketch. The condenser units C, D, E, F, and G, each have one side connected to a common terminal, A. The other side of the condensers are connected to the copper strips H, J, K, L, and M. They are \ in. wide by 1/16 in. thick, varying in length, as shown. EN A copper lever, 44 by \% by 8 in. long, is pivoted at one end, so that it will connect two or more con- densers in parallel. The pivoted end of the lever is connected to the terminals B. The dotted lines show different positions of the levers corresponding to variations in capacity. The apparatus is mounted in “a

wooden box.—PETER J. M. CLUTE. 103

~ Learn Drafting Employers everywhere are looking for skilled draftsmen. They are offering good salaries to start with splendid chance for advancement. Drafting offers exceptional opportu- nities to a young man because drafting itself not only commands goo” pay, but it is the first step toward success in Mechanical or Structural Engineering or Architecture. And drafting is just the kind of: work a boy likes to do. There is an easy delightful way in which you can learn right at home in spare time. For 27 years the Inter- - national - Correspondence -Scheols have been giving boys just the training they need for success in Drafting and more than 200 other subjects. ‘Thousands of boys have stepped into good positions through I, C. S. help, but never were Opportunities so great as now. Let the I. C. S. help you. Choose the work you like best in the coupon, then mark and mail it. This doesn’t obligate you in the least and will bring you information that may start you on a successful career. This is your chance, Don’t let it slip by. Mark and mail this coupon now, eee eee eee ee ee TEAR OUT HERG cece see ee oe INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7625, SCRANTON, PA. «Explain, without nny be how I can qualify for the bject,

position, or in the su fore which I mark X. ELECTRICAL ENGINEER SALESMANSHIP Bleectrie Lighting and Rys. ADVERTISING Electric Wiring Window T: Telegraph Engineer Show Card Writer Telephone Work Painter MEONANIOAL ENGINEER Railroad Tra Mechanica! Draftsman ILLUSTRATING Machine Shop Practice | §f() Cartoonin: Tockmaker : J BOO! Engine Operating and CIVIL ENGINEER PCert. Pub. Accountant Surveying and Mapping _J TRAFFIC MANAGER MINE FOREMAN or ENGR Railway STATIONARY ENGINEER Lj Ci ercial Law Marine _JGOOD ENGLISH ARCHITECT Sdeenant | School Sabject< Ocatractor and Rallder | Mathematics architectural Draftsman LICIVIL SERVICE Concrete Builder 2 ree Mail Cleric /Structural Engineer A MOBILE OPERATING PLUMBING AND HEATING {Canto Sheet Metal Worker Navigation Spanish Textile Overseer or Supt. . AGRICULTURE Frenci ONEMIST Poultry Raising italian Name Present Occupati Street and No City, State.

‘ Canadians a this to International Correspondence Schools, ‘Hontreah Canade ————————

be A FO A 8 ts sh ery

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any just as you want it, in fifteen minutes, time, any place, it’s always ready for use, COWAN Master Barber HAIR CUTTER correct. Made so any one can use get a good hair cut on first trial. tapered, Won’t a a Adj le

t . Comes packed in an ttractive and convenient Jeatherette-covered metal case, Blades of finest Sweedish steel, especially tempered and ground. The Cowan Hair Cutter is made of the best materials and. will lastalifetime. Itsoonpaysforitself. 5000 iN USE. Over 6000 satisfied users, But and URSELF. WHY WAIT? You'll ) anyway; accepted ne. fe Kansas City, Mo. jade wanted

- Touches the Spot. Luden’s prevent that little irrite- tion from becoming a big one. | Give quick relief. \,. from soreness, dry- } ness, throat strain. No narcotics, no coloring. Sold everywhere in the Luden yellow, sanitary package. Wm. H. Luden, Reading, Pa LUDENS MENTHOL COUGH DROPS

noted for comfort. beauty and adaptability to any climate- 5 ” Cal 53 Plans, $2500 to $7000—60cts “West Coast Bungalows” 72 Plans, $1200 to $2500—60cts PECIAL $1.50 OFFER 40 Plans, $500 to §2000—40cts Send $1.50 for all 3 books and 75 special plans. also Garsge pans. ..... P REE on Money back if not satisfied E. W. STILLWELL & CO., Architects Henne Building, , Los Ai A Folding Hand-Cart to Pass through Doorways HE accompanying illustration shows a hand-cart, which when not in use can be folded up so as to pass through any ordinary doorway. The parts are framed together in such a way that there is no need for taking

This Tank-Cap Air-Vent Saves Gasoline Moz than 200,000 gallons of gasoline is wasted daily in the United States through evaporation from the tanks of automobiles. The tank must be open so that air may enter as the fuel is used out. After gasoline vapor has col- lected in the tank, as it does especially in hot weather, it escapes through this air-vent,

Simply fold the bottom of the cart upwards and then the sides fold together carrying the wheels closer but still leaving them so that they will roll along and carry the cart. The plan view is shown clearly. The framework consists of the sides with three cross rails, each in two parts, hinged together as shown. “The side pieces are shaped with hand grips. on each end and are finished with shaped blocks on the underside to raise the body of the cart to a convenient height. The framework is shown here folded to- gether. — ._ The axle for each wheel is forged as . shown in the elevation. These pieces are fastened on the underside of the shaped block attached to the frame. The vertical part should be long enough to extend over the frame piece. When locating the axle pieces they should be placed opposite the center of the mid- die cross piece in the frame. When the cart is extended out ready for use the sides are held apart because the bottom of the cart is a neat fit between the side pieces of the frame. For convenience the bottom is made in two pieces, each hinged to the sides of the cart as shown in Fig. 4. The cart opened out and extended for use with one half of the bottom partly . opened is shown here together with the cart closed.—JOHN Y. DUNLAP.

104

The device described herein will admit air and _ prevent this loss of vapor. Thread a piece of 34-in. pipe about 2 in. long at both ends, r.

The cross pieces of this cart are hinged in such a manner that it can be folded for storing or passing through a small doorway. The bed holds the parts in a rigid position and keeps the cart from collapsing when it is being used } down or loosening any of the joints. - as shown. . One end should be closed by soldering over it a sheet of copper or tin. Drill a hole at one side of this end plate, and solder into it a tube about 114 in. long, as_ illustrated. Solder or screw the pipe into the tank- filling cap. Drill a cap to fit the pipe at one side with a 1/16-inch drill, and over the hole on the under side Air inlet . ai bo —$<$<$<$$—$—————————_ ———— OMEWERE AERIAL UD KWH. Air outlet. A trap air inlet made as a part of the regular tank vent to prevent gas from escaping of the cap solder asmall tube about 114 in. long. Then fill the pipe toa depth of about 1 in. with gasoline and screw the cap on tight. | When a vacuum is created in the tank, the air will bubble through the gasoline; but the gasoline vapor wi not be permitted to escape. The pipe should be filled with gasoline when necessary.—S. E. GIBBs. Popular Science Monthly — bast 5d

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. “3 © Hh DO rh a ml ‘ oR ST rn 2 @® PSas & ik- ipe ide E RE out 0 a and the the pipe 2 Fe var, 1919 Open the Garage Doors without Getting Out HE illustration shows the means of opening the doors of a private garage from the driver's seat of an automobile as it approaches the en- rt SOLID LINES - OPEN DOTTED LINES -CLOSED “ren ) ) PULL enurecdd iia hh ® HANDLE % pai ee The latch holds the doors closed, and when released the springs pull them open trance. Simply pulling the cord re- leases the catch, and the two spiral springs open the door. Each spring is attached to a door, and the other ends to the two posts set in the ground on either side of the driveway. An eye-bolt is placed in the top of each post for holding the end of the spring. The details show the construction of the latch and how the springs are attached.—P. P. AVERY. An Ensilage-Cutter Used for an Elevator HILE threshing an oat crop it was desired to store the straw in the mow of the barn. To facilitate this, the pipe from the stack-blower was run into the mow and the straw was blown in. In order to do away with the work A gasoline engine provides the motive power for the ensilage-cutter in elevating grain of sacking and carrying grain to the bins, an ensilage-cutter, with its blow- "er, was used to drive the grain directly from the thresher to the bins. The cutter was operated by a stationary gasoline engine.—JOE HALLIGAN. TimeandaHalf | ForStraighi lime OU can get an extra-half dollar or more for every dollar you earn now. No overtime work’ is necessary. Just your regular time and.a set of Modern Machine Shop Practice Work will turn the trick. -Read how to get these famous books written by 27 shopexperts that will help you make three or four dollars with the same effort it takes you to get two dollars now. Machine Shop Practice 6 big volumes bound in genuine American Morocco. 2300 pages and more than 2500 photographs, plans, drawings, etc. These books explain and tell you everything connected with Shop Work; more than a thousand different subjects. Not a-thing is missed—not the smallest detail. They cover everything, from the simplest machine operation to the most difficult tool and die making propositions you will ever be up against. They. will make a shop expert out of you in your spare time and it will only cost you 7 cents a day to buy the books after a weeks’ free use. : Shop Work, ee same rare sear Cutting, wd xpiain Lathes and Screw Machines, Planers, Millers, Jigs, Shop Management, Metallurgy, Weld- ing, Die Making, Laying Out Lies, Tool Making, High Speed Steel, Thread Cut- ting, Milling Cutters, Punch Work, Tool Design, Foundry Work, Molding, Malleable Practice, Forging, Heat Treatment of Steel, Annealing, Hardening, Pattern Making, Mechanical Drawing, Design of Machines, Auto, Shop Work, Machine Drawing. et eae ete Ask Our absolutely free, one EXPERTS years’ consulting membership in the American Technical Society. It usually sells for $12.00. This entitles you to write in at any time within a year and ask our experts’ advice about anything connected with shop work that you don’t understand. Use One Week FREE! Don’t send any money...Just the coupon is all you need. We will ship the books express collect and you can use them a whole week in your own home or shop just as if they were your own. Try to find some tough proposi- tion they won't explain. Show them to the other men in your shop—give them every test you can think of and send them back at our expense if you_don’t want to keep them. , If you do want the , Cents books to help you earn more, like thousands a Day of other men have done, send us only $2.00. You can send the balance of our special $19.80° price the same way —$2.00 .each\month* Begin’ now-to get‘ ahedd—do it the speedy way,t0o. This coupon is your ticket on the spéedy route. MAIL IT-TODAY. AMERICAN TECHNICAL SOCIETY Dept. M-1203 f Chicago, Ill.. U. S.A. (ERD GF GEees awe) Meme ee FREE YE OO MER Sr nme GommUreS ame AMERICAN TECHNICAL SOCIETY, Dept. M-1203, Chicago, Ill., U.S. A. Please send me the six-volume set of ‘Modern Shop Practice’ for seven days’ examination, I decide to buy,.I.will send $2.00 within,seven days and balance at $2.00 a month until $19.80 has been paid. Then you will send mea ‘receipt showing that the set of books and the Consulting Membership are mine, and fully i shipping charges collect. the books, I will return them at your expense after seven days. 105 id for. If I want to get along without | AK Pe EPS

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Investment Opportunities is the title of a fortnightly publica- tion containing timely articles on meritorious securities offering at- tractive market-profit possibilities. Those interested in investing their savings so as to obtain the maxi- mum income yield, commensurate with safety of principal, should not fail to regularly receive this valu- able publication. It will be sent free of charge, be- ginning with the current issue, upon request for 1-PS, including booklet explaining Dhe Twenty Payment Plan LATTERYAG 40 Exchange Place, New York | BROWN’S . BRONCHIAL TROCHES Quickly Relieve Coughing, Hoarseness, Sore Throat For seventy years these tablets have been faithfully serving speakers, lecturers, vocalists and thousands of others, in quickly easing sore throat, hacking cough, loss of voice, bronchial and asthmatic troubles prevalent in winter. Not a confection, but a genuine remedy. Contain no opiates or other harmful ingre- dients, hence are especially safe for children. A small piece relieves a sore throat. Four sizes, 5c, 35¢, 75¢ & $1.25. Al all druggists John Boston, Mass. . Brown & Agents for Continent of America: . Harold F, Ritchie & Co., Inc... New York—Toronto Safe Handy De; endable AGENTS 3222 °/ Gold and Silver Sign Letters For store fronts, office windowe and giass signs of allkinds No experience necessary. f° one can put them on and make money right from the start. $30.00 to $100.00 a Week! You can sell to nearby trade or travel all over the rountry. There is » big demand for win- dow lettering inevery,town. Send for Free Samples and full particulars. Liberal Offer to General Agents. METALLIC LETTER CO., 400 N Clark St. Chicago ————————— ae A Home-Made Power-Driven Air-Pump for a Bicycle POWER-driven pump with which one can inflate bicycle tires, or blow a deep-toned chime whistle as a warning is a thing many a bicycle owner will want. An ola tire pump. a PUMP TUBE x Se cn STRAPS PULL CORD UPRIGHT OF WBICYCLE FRAME \ CONNECTING \ ROD SPRING YA) \ FULCRUM 4 Wp > ey Oi® 7 @B {Oy L-EN ENGAGEMENT \ \ LEVER Vis) 7 oY) ths. a SMALL SPROCKET ™~* Ml) CMMI UME) | CHD. Gl)’ ern BezA»>, C Ye Yb 4,” / The pump and its driving parts are attached to the seat post tube of the bicycle frame “rear’’ sprocket and a few odds and ends are all that is necessary to build such a contrivance. First, make the engagement lever the shape illustrated and bore one hole at the angle and another half way between the angle and the end of the long arm. Then drill two small holes at ach end. Mount this lever upon the upright post of the bicycle just forward of the rear wheel in such a position that when the small hole in the end of the short arm is in a hori- zontal position with the pivot bolt the sprocket wheel at the angle will clear the bicycle chain by about 4 in. The sprocket is arranged to turn freely and the lever is so fixed that it will swing easily upon its pivot. This pivot can be arranged to strap securely to the frame by means of metal bands attached to a block of hard wood. Now, at a proper distance to give a good stroke, strap a common bicycle pump above this lever with piston rod pointing down. Flatten out the end of the rod and drill in it a 3/16-in. hole. Connect this rod to the sprocket with a connecting rod of strong metal. The sprocket should be previously drilled near the edge to make this connection. The whole thing must oi course be ar- ranged so that it will line up correctly with the chain. A weak spiral spring should be at- tached to the hole in the short arm and carried to a point above, which will hold the sprocket at the proper distance above the chain and a pull cord tied to the other end of the lever with which to engage the sprocket. This can be carried to the handle bar or near the seat, as preferred. By pulling on the cord the sprocket 106 is forced down upon the chain where the teeth engage and cause it to turn as long as the pedals are being re. volved. Consequently, the piston of the pump is overated, forcing a blast of air. wherever cesired. This, of course, ig best done while the rear wheel is off the grovad and the bicycle resting upon tne stand. The Rolling Hoop or Wheel for Children HAT mere man has long been addicted to idle smoking and chewing is commonly known; but lesg — often is it observed that the idle carry. ing or swinging of something is almost as deeply rooted a characteristic. This may be traced from the crude club of primitive days to the gnarled and crooked stick and the fine and fancy canes and walking-sticks of to-day, which serve no purpose, but simply seem to afford their habitual carrierg a sort of comfort and satisfaction in handling. Even the soldiers of to- day carry “swagger-sticks’’— obviously too short for support, too light for a weapon, and with no pretense to use- fulness. Neither have women been excep- tions to this habit—from the slender beribboned staff of the Colonial dame to the handsome little stick carried by the stylish woman of the present day. Likewise, children exhibit this same characteristic in an even more marked degree. There is a strong attachment between the country lad and his reed or switch, which is almost always with him; while the city boy has his stick, with which he rattles fences, barrels, etc. There have also been a line of moving devices, such as hooples, of various kinds—all of which gratify an pa | fy Eoys love to roll hooples down hill. Here is one which can be simply made by any boy innate desire apart from the one that craves the passing plaything. In this connection, the hoop shown here has two novel features. It is made of solid wood—a barrel- top will do. The stick is fastened to the hoop. As the boy runs down hill with the stick in his hand, the barrel top revolves. Popular Science M onthly : —_— |

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cy ant ere nat nas rel- hill ~ March, 1919

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| cee NJ Noiseless Target Practice ” ‘Fit your 22 with a Maxim Silencer and get no end of fun ig winter practicing in backyard and basemen IM SpLENCER It eliminates recoil and all noise of FREE the report, and steadie: your sim. BOOK Fits a7 .22 or .22 hich power rie. Book of stories of actual users, free. MAXIM SILENCER CO. 93 Homestead Avenue., Hartford, Conn.

| To Repair a Leaky Fountain-Pen Quickly OMETIMES a fountain-pen unex- pectedly springs a leak at the base of the quill. A repair that will do the trick, and that will answer for a considerable length of time, is to run a little melted wax, sealing-wax, or soft chewing- gum aroundthe insert of the pen. Clean that portion of : : the pen thor- Sune the leak with oughly before sealing-wax or gum attempting to seal it.—L. B. ROBBINS.

FILL WITH MELTED WAX Replacing Section of Gas-Main While the Gas Is Turned On VERY interesting process by which a cracked section of a gas-main was repaired without having the gas shut off is shown in the illustration. By means of this arrangement the gas isconducted by or past the section being worked on. — It was also flexible so that it could be swung to one side or the other as the work required. Holes were drilled at A, B, C, and D, and tapped for plugs, ana rubber gas bags inserted in the holes A and B, and inflated to shut the gas off from the broken section. The flexible by-pass was fitted on and connected |: | with unions. The arrows show the passage of gas through the by-pass. Cc A Cracked B&B 6

Golden Sem PORTABLE re ‘Adding Machine” ls Aimy . E. Gancher, A. A. M. Oo, 48 Duane St., New York Canadian ‘Agency

St wren Fons NOW oe ian ad ven We revise poems, compose music of an: me er Tm day a and em- J q VRE PUBLICATION oroutright SALE of songs otek GU. A Postal neem brings copy of our Free Booklet which tells you who we ere, explains our methods and contains valu- i “ Tetsemation and instructions. your opportunity to learn the thevh etek the Song-writing profession from a re.jable and successful concern. KNICKERBOCKER STUDIOS, 88 Gaietv Bidg., N. ¥. City ARMATURE AND MAGNET WINDING By Horstmann & Tousl -A necessary book for, actriclans. sn ull facts and Gaerne, $1.50 . Popular Science Mocthly. 225 W. 39th St., New York

Two rubber bags, one in in each pipe-end, were used to shut off the gas in the mains After a new section was fitted in place with couplings and a piece of pipe, the couplings having right and left threads, the bags were removed, and the by-pass and plugs were turned

into the holes.—JAMES M. KANE. 107

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Red Seal Dry Batteries Are Eerasleed f= to give absolute satisfaction for Automobiles, Motor Boats, Gas or Gasoline Engine Ignition, Medical Batteries, Telephone, Door Bells, Annunciators, Wireless Apparatus or any other open circuit work. ASK YOUR DEALER Send for Our New Edition of Our Catalog A28 It will be pocket size, 8 x 4}4 and will contain 248 pages with ov 1.100 Mlustrations, describing in plain, clear language all about Bells. Push Buttons, Batteries. Telephone and Telegraph Material. Electric Toys, Burglar and Fire Alarm Contrivances, Electric Cail Bells, Electric Alarm Clocks, Medical Batteries, Motor Boat Horns, Electrically Heated Apparatus. Battery Con- Say Switches, Battery Gauges, Wireless Telegraph Instruments, Ignition upp ete. SS MANHATTAN ELECTRICAL SUPPLY COMPANY, Inc. NEW YORK, 17 Park Place CHICAGO, 114 So. Wells St. ST. LOUIS, 1106 Pine St. SAN FRANCISCO, 604 Mission St. Stronger, Clearer ‘Voice for you! BENJAMIN Weakness, Speaking of air huskiness rifles, why not buy og harehnens the best and safest? voice given awon- Only real pump gun ever invented. nlike all others, it never loses shooting force. Man and boy’s gun for target practice and small game hunting. This outercted inch block of wood shows the various degrees of shooting force. This is a feat no other air sifle can duplicate. Price $3.75 Postpaid in U.S. Descriptive folder on request. Ask your dealer for demonstration. BENJAMIN AIR RIFLE & MFG. CO. 607 N. Broadway, ST. LOUIS, MO. derful strength, a and giv ing quality go the an ive @ surpassing ~ i] 3 Send for the fi fa. Do You Stammer? ha’ diene ve ve any voice impediment ot a fearmneg oe ap He von Zpon for free bouk. WRITE! Send the coupon and t our free book and literate es We ° will Rae gt what thig method f homies A seom the cent. No obligation on you if you 300 k this inf We send it Ec; pectage propel. Juste ALY =n Perfect Voice institute 1772 Wilson ave. iil. - Send.me the.veok and facts: about the Feuchtinger Method. Have put X oppo- site subject that interests me most, D Singing D Speaking O Stammering OD Lisping Learn Electricity. EARN $25 TO $60 ta PER WEEK At America’s greatest practical § in- stitution. Finest caninme No THE BOY ELECTRICIAN Practical Plans of Electrical oa oy for Work and Play with an Explanation of the Principles of . Every-day Electricity. $2.00 Postpaid. co POPULAR SCIENCE MONTHLY, 225 W. 39th St, New York | Dept. 33. books. No classe: All individual a mt sate education evening school, course interests you. YNE TRADE AND ENGINEERING SCHOOLS 39-51 East Illinois Steg Chicago, Il. SAVE YOUR BODY Conserve Your Health and Efficiency First “JT Would Not Part with it for $10,000°° So writes an‘ enthusiastic, grateful customer. ‘Worth more than a farm,” says another. In like manner testify over 100,000 people who have worn it. THE NATURAL BODY BRACE Overcomes WEAKNESS and ORGANIC AILMENTS of WOMEN and MEN. Develops erect, graceful figure. Brings restful relief, comfort, ability to do things, health and strength. Wear It 30 Days Free at Our Expense Does away with the strain and pain of standing and walking; replaces and sup- ports misplaced internal organs; reduces enlarged abdomen; straightens and strengthens the back; corrects stoop- ing shoulders; develops lungs, chest ‘and’ bust; relieves backache, curva- tures, nervousness, ruptures, Constipation. Comfortable and easy to wear. Keep Yourself Fit Write today for illustrated booklet, measure- ™ ment blank, etc., and read our very li proposition. HOWARD C. RASHES Pres. Natural Bdy Brace Cos How to Make a Section Liner from a Carpenter’s Clamp ig pentane a section liner for 4 number of jobs, a@*aftsman, who did not feel able to purchase one, made the one here illustrated for his own use. The base and supports were made from an old packing-case. The screw A and block B, Fig. 1, were taken from a carpenter’s clamp. The collars D, Fig. 3, are heads made from an empty cotton spool, Rivet bopanites The wood screw of a carpenter’s clamp furnished the spacing device for this section liner one of which is notched and the other one glued to the screw A. An old clock key inserted in a slot cut in the end of the screw A provides a means of turning it. The screw A, when in position be- tween the supports, should fit snugly and allow no end play. When the key is turned to the right, the screw A, with the collars fastened to it, revolves in its supports and draws the block B toward the key end. The distance the block is drawn depends on how far the key is turned each time, which may be easily gaged os the notches in the collar. To do graduated shading, a gear wheel from an old alarm clock, with part of the teeth filed off, should be soldered to the gage screw of the ruling pen, as shown in Fig. 2. By turning this wheel in either direction one notch ‘at a time, the pen is opened or closed an equal distence, thus giving lines of different widths. The section liner complete, as shown in Fig. 4, is, of course, used, but the spacing is not changed as with the pen. With this section liner a draftsman can do as good work as with the most expensive tool on the market. It may be a little slow to work, yet it is accu- rate if the adjustments are set true to Popular Science Monthly the markings, and if the screw threads | fit the nut snugly.— ALBERT E. JONES.° os | me de de w N A. i I A 8 fe i fi J mo | een Imoesoecs PA. Whee le es T-—

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ES I Booklet gives full information—write for it. f: 4 The Calvert Mortgage Company f: "4 869 Calvert Building Baltimore, Md. |: Deafness ji Perfect hearing is now being ree Esme stored in every condition of deaf- ness or defective hearing from ’ causes such as Catarrhal Deaf- ness, Relaxed or Sunken Drum hickened Drums, Roaring an Hissing Sounds, Perforat ‘ 2 Wholly or Partially Destroy We ="'7% Drums,Discharge from Ears, etc, Wilson Common-Sense Ear Drums *Zittle Wireless Phones for the Ears’ require no medicine but effectively replace what is lacking or defective in thenatural eardrums, They are simple which the wearer easily fits into the ears where they are invisible. Soft, safe and comfortable. Write today for our 168 page FREE book on DEAF- NESS, giving you full particulars and testimonials, WILSON EAR DRUM CO,., In ted 24 Juter Southern Blac. LOUISVILLE. RY. Build Your Own PHONOGRAPH It's Easy With Our Help “Saas SAVE interesting work \ A tet Te ta pes sot \ OVER machine exactly to suit your ALF - f bh tors, t = f\ ee arms, case 1 and full instructions. Plays an . You can make fine prof- i pailding phonographs for your nds. Write Today for Our Free Blue Print Offer ted f Raliete sented tor om CHORALEON CO. 603 Monger Bidg., Elkhart, Ind. T Ney Sa, $10 and up. All makes. Save $25 to $50 mn rebuilt at the factory by the well- known “Young Process." Sold for low cash—installment or rented Rental sopeee on. purchase price. Write for full details and guarantee. Free trial. YOUNG TYPEWRITER CO., Dept. 804, Chicago, tM, taise Belgian Hares for us. Wonderful profits easily made athome. We furnish stock and pay you $6 a pair and express charges and buy all you raise. cavies and squabs. Beautiful illastrated catalog and contract 10c UNITED FOOD & FUR ASSOCIATION 329 West 48th St. Desk 4 New York TYPEWRITER %* SENS ATIO monthly buys a Beautifully Re- constructed Latest Model Visible Typewriter with back-spacer, decimal tabulator, two-colo ‘ribbon, etc. Eve-y late style feature and modern operating conve- nience. Perfect appearance, perfect action and abso- lute dependability. Sent anywhere on approval. Cat- alog and special price FREE. Harry A. Smith, 306, 218 N. Wells St., Chicago, Ill. 7 Print Your Own cards, circulars, labels, tags, menus g) book, paper. Press 36. Larger 3.0. Job F°Y Press $35 up. CUTS EXPENSES IN HALF. = Kite, SMALL OUTLA . Pays for aS itself in short time. Will last for years. Easy to use, printed rules sent. Print for others, BIG PROFIT, Write factory TODAY for press catalog, TYPE, cards, paper. Se A 4, 3S 1260) 3 Te] THE PRESS CO., 0-33, Meriden, Conn YOU CAN’T LOSE PEN or PENCIL Get this UP-TO DATE combina- tion c hone and yearly calendar. A Poultry Roost that Will Destroy Mites NE successful way to rid poultry houses of mites is to use a roosting- pole that will harbor them during the day, so that it can be soaked with Grooves End view ie aperature A hiding-place is provided for vermin in this poultry roost to catch them during the day hot water to destroy them. The roost shown provides a place on the under- side where they may hide.. It consists of a lath held under the roost with small nails to make the hiding-place inviting for them. You simply lift the roost from the holders, slightly loosen the pieces of lath, and pour boiling water between the lath and the roosts. This will kill all vermin and destroy any eggs that may be there. The roosts will quickly dry if the water is hot. _In this way a poultry house can be completely cleared of all blood-suckers on the place. The iron ends are colder than the wood, and the vermin will not crawl over them. Mites do not attack fowl in the day- time, and it isedifficult to discover their presence. Body-lice remain on the fowl all the time, and they may be exterminated in the following way: Hang the fowl head downward in a barrel, and rub a small amount of fluoride of soda well into the feathers for half the length of the fowl. This is a harmless powder and it can be used on chicks as well.— GEORGE W. SMITH. Easing the Action of a Drill | in Soft Metal HE amateur mechanic is often troubled when drilling in soft metals, such as copper, brass and lead, by having the drills twist or. break off in the LIES chuck. This can be overcome to i a great extent by grinding the cutting edges of the drill in the | manner: indica- 1 ted in the illu- it stration. + 3 Probably the best method of grinding is to A slight fat surface prevents sticking have the plane of the new face A about parallel with the axis of the drill. Make the face quite small—about 1/32 in. “ of pen or "Bost nine ot. "ACs Stats fr Bon git ARGUS MFG. CO.. Deot A. Send stamps 402-406 N. Paulina St.. CHICAGO, ILL. oncom is big enough.—L. B. ROBBINS. 109 \ Don't Be 2 Sickly Grouch! Nebcdy ioves a grouch—nobody likes to meet him -in the street, do business with him or have him around. And you can’t help being a grouch, if your internal ma- chinery is runnirg wrong; if dyspersia or biliousness make your life miserable; if headaches and backaches take the tuck out of -you; if constipation is poisoning your blood and beclouding your brain, or if early excesses have sapped your vitality. ' Get Rid _of Your Ailments _ You are‘only half a "» ran when you stagger along under such hand- Icaps; you -can’t win out, you can’t make a success of anything; you are bound to be a failure—you know it, your wife knows it and all your friends know it. Don’t lay it on your ston ach or liver or lungs—take hold of YOURSELF— build yourself up into a MAN again; turn over a leaf and live life as Nature meant.it should be lived. STRONGFORTISM Will Show You How! Strongfortism is Nature’s way, and there isn't the slightest doubt in the world that she can build you up and bring you back to health and strength and the enjoyment of living life again, if you give her half a chance. Strongfortism has salvaged thousands.of human wrecks; has put vigor, vitality, hope, happiness into men who felt they were hopelessly down and out, and brought joy to wives who had well nigh lost all confidence in their husbands. Strongfortism will help YOU, as it has helped them; will show you Nature’s safe, simple, sure way back to health and strength.and mental vigor. Think of your future; of your wife, of your chil- dren, of the children you and she may have. Don't delay a single day; learn about Strongfortism—the one way to happiness for you all. Send for My Free Book “Promotion and Conservation of Health, Strength and Mental Energy”’ tells you all about Strongfortism. It tells how I became the strongest man in the world by practicing it, and how my pu- pils in every part of the world have freed themselves from the handicaps that held them back, and are forging ahead in the world. Remember, Strongfortism is Nature's way, the one sure way; no. drug store dope or patent med- icines—just giving Nature a chance to dispel your ills and build you up. Send three 2c. stamps to cover postage and packing and I’ll mail you a copy atonce. SEND TODAY, using Coupon below. LIONEL STRONGFORT Physical and Health Specialist 766 Park Bidg. NEWARK, WN. J. sasawCUT OUT AND MAIL THIS COUPONe can STRONGFORT The Perfect Man Mr. Lionel Strongfort, Newark, N. J. Year Strongfort:—Please send“me your book ‘* MOTION AND CONSERVATION OF -HEALTH, STRENGTH AND MENTAL ENERC Y,"" for postage of which I enclose three. 2c stamps to cover*mailing expenses. I have marked: (X) before the’subject in which I am interested. » (766) . Colds a . Torometa .- Weaknesses .-Catarrh . Short Wind . Gastritis 28 ‘.. Asthma . . Fiat Feet teHeartweakness ~ . - Obesity . Stomach .- Poor Circulation ..- Headache Disorders +. Skin Disorders ..- Thinness . Constipation of ¥ . .Raptare . . Billonsness . Round Shoulders .-Lumbago .. Torpid Liver . Lung Troubles . .Nearities . . Indigestion .. Inorensed Height . Neuralgia . . Nervoncness ve .- Flat Chest ..Poor Memory Shoulders .. Deformity . Rheomatism ».Museular (deseribe) ..Bad Habits» * Development DAMM ac oc ccc ccna: 009 6bebbescuee Ven yeas ears MOGG ise OCCUPATION ....0:ccccssesctvescevevess BTRBRT. 2... ccc ccc ccc cc ccsececls Cheseeewete Ohne ee OU U ous cakes cntns covugesuaes STATE... Mss Pwdeinee . 1 { | 4 |

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DRAW ING Bic Pay—Easy Pieasant / Draftsman earti $150.00 to $300.00 a month. The work. is pleasant and the hours are You can | new. 19 a little Secthe Cyclopedia of RAW ING hand Brawing=Pen and ink Rend. ciate Says | things connected with the work. * | wec'e FREES WEEK SGaa si You can have these books for a whole sen ince of roductory price — only $14 80 the .00 each month. é don’t take any chances. The risk is al} its will all be yours—Send the ‘echnical Society 7 STOPS LEAKS fl Smooth-On Household | Iron Cement No. 1} Stops household leaks, cracks, ) or breaks in pipes, stoves, fur- § naces, sinks. Repair perma- 9} nently with SMOOTH-ON—a ff putty like Iron’C b. SOc SMOOTH-ON MFG. CO. oz. SSC. Jersey City. N,J..U.S.A- je. Siang eS an $$ MAKE A MOTOR CYCLE OUT OF YOUR BICYCLE wih 2 STEFFEY MOTOR. Easy to attach. FITS ANY WHEEL. ae More STEFFEY’S in use than all others. Send stamp for circulars and low factory prices. Agents wanted. STEFFEY MPG. CO. Dept. S, 5025 Brown St., Philadelphia, Pa. ELECTRICITY MADE SIMPLE A book devoid of technicalities. Simple, plain and understandable. $1.00 Postpaid. Popular Science Monthly, 225 W. 39th St., New York A Jointing Jig for a Circular Saw Table ITH the jig illustrated a cir- cular saw table and machine may be made into a combination saw and jointer. This device is especially valuable in jointing short pieces of board for gluing, as the edges of each piece can be made straight and square, ready for the glue at one cut. The jig may be made of 114- by 6-in. kiln-dried stock for the sides A. The separators B are made of hard wood gage R guides the jig as the board ig fed through the machine. The groove S in the bottom of the jig is to allow the cutters to clear and leave enough wood on the lower edges of the sides to rest firmly on the table.—CHARLEs A. King, The Use and Construction of Volta’s Electrophorus HE electrophorus is an instrument devised by Alexander Volta in 1775 to obtain a series of electric charges of electrostatic induction from a single charge. It con- sists essentially of a non- conducting plate which can be easily excited by friction, and a metal disk of smaller diameter than the plate, provided with an insulating handle. -The plate is most conveniently made of ebonite, although such plates were originally made by melting together resin and shellac and pour- ing the mixtures into a shallow tin. The ebonite plate A D should be circular in shape to fit tightly into a cheap ® shallow tin. It should be : cemented to the tin with 2 in. square, and the sides are fastened to them with screws. Tjhis will permit one or more boards, which aggregate less than 2 in. in thickness, to be joint- ed at once. The screws C are to hold the board firmly in the jig; therefore the sides in which they are fitted must be of hard wood to hold the threads. The screw D prevents end motion. If a narrow piece of sandpaper is glued upon the inside of the jig directly op- posite each of the screws C, it will re- duce vibration and prevent the board from slipping. The bottom of the jig must be jointed perfectly straight and square with the sides so that it will rest upon the table without tipping. The jointing head is a piece of hard wood F about 21% in. thick and large enough to clear the collars G and H and allow the cutters T to project above the table at J. The cutters are held in place with bolts at K. The wood, bolts, and cutters must be care- fully balanced. It is quite necessary to have a long mandrel or arbor to allow the jointing head to fit against the collar H and -nut M, although the collar H may be omitted if the -hole in the wood fits the arbor closely. The saw table should have a movable throat which fits in at N to permit the jointing head to be used. Place the guide D loosely against the side of the jig, as at Q, to prevent the jig from swinging against the side of the cutters. The regular splitting 110 4c g S Ry IAAT 0 7 } Wx oO be ‘\“E , w if M : - asia al The jig will hold a board in an upright’ position so that its edge may be planed squarely on a jointer | a little gutta-percha or an elastic glue, the applica- tion being of light pres- sure and projecting slight- ly over the top of the tin. For very good results the ebonite need not be over 14 inch thick. It is absolutely essential, in order to obtain the maximum efficiency of the machine, to have all edges perfectly -round without any sharp angles. If these requirements appear to be too rigid for the builder, the metal tin—or “‘sole,”’ as it is called—may be left entirely out of the construction. A sheet of zinc is next required. This should not be more than 1/20 inch nor less than 1/25 inch in thickness. If this cannot be purchased in circular form, it must be cut from sheet stock. The outer edge of the zine should be rounded or turned up by careful hammering. The diameter of the ebonite circle should be not less than 8 inches, and the zine disk about % inch less. A short piece of brass or zine tubing. is soldered in the center of the smaller disk for the insertion of the insulating handle. This tube should not be larger than 5/16 inch in diameter. Instruments bought in shops usually have glass handles, but these are not so good as the ebonite. The finished product shou!d appear as shown at B in the illustration. To use the electrophorus, warm plate A slightly until it is free from moisture. Then charge it negatively by friction. This is done by rubbing it or striking it with warm flannel or fur. The metal base then has a bound positive charge, which helps to hold ‘ the negative charges on the ebonite A. Popular Science Monthly q et — ~~ bet et SS SCO ot as xs Pe tte mm 8 ot CLS lle Sat at ae wil ek.” et’ ote CU, Ce CO Bees ee

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ter. ally » not hed t B arm rom vely bing 1 or yund hold ° » A, March, 1919 By means of the. insulating _ handle place the zinc disk on the plate. Owing to slight irregularities, on, the surface of the two plates, they. will touch at a few points. There is in- Zine disk | Bross tube Ll Shallow tin’ Ebonite-” ray An electrophorus for making a series of charges of electrostatic induction from a single charge duced in B a freé negative charge and a bound positive charge, as is illus- trated in A. The metal disk B is then touched with the finger, which is equivalent to connecting it to the earth, and the negative charge on the upper surface disappears. Remove the finger and raise the disk by the insulated handle. By this process the positive charge is made a free charge and can be trans- ferred to an insulated sphere. | This procedure can be repeated, the plate B being charged each time without decreasing the charge on the ebonite plate, the energy represented by the induced charges being obtained at the expense of the operator who draws out the lines of force connect- ing both the positive and negative charges.—HERMAN NEUHAUS. ” Discarded a Used : for a Plant-Box NEW use was found for a dis- carded water-heater by cutting out one side and filling it with earth for holding plants. Such a_ plant-box An old range boiler painted to resemble a birch log and used for a plant-box may be painted to suit the owner, and it may be made very effective if tinted to resemble a white birch log. By copying a birch log or tree from which the white bark has been peeled in places, allowing the brownish second layer to show through, the painting may be made very effective. Paint the boiler two coats of cream color, and then streak it with lines and patches of reddish brown, taking care not to make these patches too even or too regular.—W. H. SARGENT. TENT TRADE-MARKS AND COPYRIGHTS Before disclosing an invention, the inventor should write for our blank form “EVIDENCE OF CONCEPTION.” This should be signed and witnessed and returned to “us together with model or sketch and description of the invention, and we will give our opinion as to its patentable nature. Our Illustrated Guide Book, HOW TO OBTAIN A PATENT, sent Free on request. Contains full instructions regarding Patents, Trade-Marks, Foreign Patents, Our Methods, Terms, and 100 Mechanical Movements illustrated and described, Articles on Patent Practice and Procedure, and Law ‘Points for Inventors. Highest References Prompt Service Reasonable Terms VICTOR J. EVANS & CO., Patent Attorneys i i New York Offices Philadelphia O7ices Pittsburgh Offices 1001 Woolworth Bldg. 135 S. Broad Street 514 Empire Bldg. Main Offices: 760 9th Street, N. W., WASHINGTON, D. C.- [ GENTLEMEN: Please send me FREE OF CHARGE your Book as déscribed above. } an Seen es ren ee ee ‘PATE To the Man With an Idea | I offer a comprehensive, experi-: QQeueerarea pe PEc sce aaa eee ecakL Pate cca eceeaserecise PATENT % Trade Marks Send sketch or model for actual search and report. Write for Book- let of instructions on patent practice and procedure. Prompt personal service.... Geo. P Kimmel Patent Lawyer 39-R Oriental Bldg., Washington, D.C. DECTECUCHUACL ATIC LOCOLEETES Ti Pear dade raraeaeeiies ecerecasagrabaeasdeniard enced, efficient service’ for his prompt, legal protection and the development of his proposition. Send sketch, or model and. descrip- tion, for advice as to cost, search through prior United States. pat- ents, etc.. Preliminary advice glad- ly {urnished wichcut charge. My experience.and familiarity with vari- ous arts, frequently enable me to accurate- ly advise clients as to probcble patenta- bility before they go to any expense. cuhdaroesetaetdsabetarebereyis Booklet of valuable information and form for properly disclosing your idea, free on request. Write today. RICHARD B. OWEN Patent Lawyer 6 Owen Building, Washington, D.C. 2276-D Woolworth Building, New York City~ ~ POORER OT URBESIVEDROTECS CROC tEe Se UE UU USOR ERE SSEES EE RS, CUMEREU TART EP PAE PL EAT Rasa r vat eek ara ey aaey res DATENTS PROCURED and TRADE-MARKS REGISTERED Eighteen Years’ Experience. Instructions and Terms on request. ROBB & ROBB, Attorneys at Law Specializing in Patent and Trade-mark Practice exclusively 840 Southern Bidg., 1336 Schofield Bldg., Washington, D. & Cleveland, Ohio. Competent Patent Service By a Former Examining Official of the U.S. Patent Office NORMAN: T. WHITAKER Lawyer and Engineer 280 Whitaker Bldg., Wash., D.C. ‘ |NQUIRIES INVITED IF YOU HAVE = AN t AT = oh T S INVENTION AND DESIRE TO LEARN HOW TO 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 === aes os a = aoe oe patentable nature. - PAP Reem R eee eH eee eee RHEE EEE E SESE EEE HEED RANDOLPH & CO.' «a... 130 F St, N. W., Washington, D.C.) ry 111

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PATENTS Write for free booklet Terms Reasonable Highest References Best Results Send model or drawing for preliminary examination and report as to patentability ALL BUSINESS GIVEN PROMPT AND PROPER ATTENTION WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D.C. CAN YOU think of a simple, piticd 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 RIGHT Now. Your brains can help. Send to- day for our great new book—“Inven- tions and Trade Marks, Their gee area and_ Exploitation” . learn’ more about cae from ideas than you ever - ore. For SALE FREE Advice free. In INVENTION And oe bo P ‘ Foote neg Published for the ES, INC, man with an idea. Send for free sample 201 Patent Dept., copy. One year’s sub- WASHINGTON, D.C, : J scription 50c. je DIAMONDS Od Sealed NCREDIT Our Great Special! ‘Loftis Perfection Diamond Ring The Most Popular Solitaire Dia- mond Ring. Each Diamond is —, eT pee! _ nd experts, an skilful- og mounted in our famous Cased in Handsome Ring Box Loftis “Perfection” 14k solid gold 6-prong ring, possessing every line of delicate grace and beauty. A Genuine Diamond Is the best investment into which Bafuctand tgs forever” vey erick lated ia ou ver, Catalog is distinctive in plehnees and elegance, no matter what the price. LIBERTY BONDS ACCEPTED. Send for Free Catalog There are over 2,000 illustrations of Diamond Jewelry, etc,. Whatever you select will be cout, r ihe Behicke mei i Vit ome wanaen fied, pay one-fifth of purchase price and k ance divided into eight eq! - . wh payable LA. SPECIAL OFFER! ,-33., WATCHES 39, That Will Pass Rallroad Inspection ONLY $3.00 A MONTH Our Catalog illustrates and describes all the new watches —- 17, 19, 21, 23 Jewels, adjusted to temperature, isoch- nism ‘and positions. All sizes for men and women, Your choice xa the Sen aidaee fashionable designs, Guaranteed Fris™ guaranteed by us. The National Credit Jewelers _— L S7a 88. STATES?., curcaco erdnesinacapinc cies =| to be accurate timepieces, in perfect run- PATENTS LACEY & LACEY Attorneys-at-Law — Patent Practice Exclusively Solicitors of U. S. and Foreign Patents Trade-Marks, Copyrights. 646 F Street, N.W., Washington, D.C. Write Us for Our Inventors’ Booh _ PATENT-SENSE 3 -ABLISHED 1 274 OURAY BLDG, j DO NOT LOSE YOUR RIGHTS TO PATENT PROTECTION Before disclosing your invention to anyone send for blank form “‘Evidence of Conception’? to be signed and witnessed. Establish your rights before filing application for patent. As registered patent attorneys we represent hundreds of inventors all over the U.S. and Canada in the advancement of their inventions. Terms reasonable. The form “Evidence of Sqnesption,” sample, instructions relating to obtaining of patent and fee schedule sent upon request. Ask for them,—a postcard will do. my Build and F ly lng Covet! acts opines: wat” INVENTORS: Send us sketches of your invention and a description of the de- vice for advice in regard.to the best way of obtaining patent protection. Our practical experience covers a period of twenty Our hand-book on patents is sent free All communications strictly con- years. on request. fidential. Write us today. TALBERT & TALBERT Patent Lawyers 4621 Talbert Bldg., Washington, D. C. ARMATURE AND MAGNET WINDING By Horstman & Tousley A necessary poe! 4 electricians. Full facts and diagrams, $1.50 po Popular Science B Monthly, 225 W. 39th St., New York 112 A Home-Made Automobile Crank-Holder and wearing the bearing unnecessarily, Radiator, Drill of crank A coil spring holds the’starting crank of an automobile to keep it from rattling and prevents noise and wear. lubricated. A Lathe Dog Used to Pull Out a Tightly Fitting Key end of the key. in Arrangement of the lathe dog, set-screw, and nut for pulling a tightly fitting key in a shaft key with them.—E. S. GOODELL. a persia cranks fastened to an ‘ automobile cause much trouble’ and annoyance by swinging, rattling, ‘Extreme movement By the use of’an ordinary hook-end spiral spring of proper length to give a medium tension on the crank, these faults may be eliminated. To make this, drill a 3/16-in. hole in the frame, or fasten to a convenient bolt a 4- to 6-in. coiled spring, which may be purchased cheaply at any hardware - store, with ends bent out to fit the bolt and crank. This holds the crank rigid A few drops of oil placed at .A will keep it O remove a tightly fitting key, a lathe dog, 2 hexagon nut, and a~’ set-screw—all easy to obtain—will do the work. Clamp the hexagon nut with the lathe dog, and turn up the screw tightly against the. projecting In turning the set- screw through the nut the end will make a bearing on the face of the hub of the wheel. \4 Popular Science Monthly ae Continuing to turn the set-screw will raise the nut and lathe dog away from.the hub, drawing the >

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lo it 1e 1g t- ill ib 1€ he he “March, 1919 ey A Riveting Stake for Use in the Bench Vise \HERE is often need for a riveting |} stake in a small shop for various kinds of ‘riveting. The usual thing the workman.does is to put any old piece of bar stock in the bench vise, and proceed to squeeze it up as tight as possible to keep the iron from moving when striking the riveting blows. Often the vise screw is damaged or the vise broken by this overstrain: just as often the badly chosen piece of stock slips from the grip of the vise, ‘eausing delay and sometimes injury to the workman. The sort of stake shown in the illus- tration has been found the handiest tool for this work. It is easy to make, for it is simply a piece of suitable round ; ‘ Just how the pins should be driven into the stock to enable the vise to get a lasting grip stock with one end bent at right angles, and a couple of pins put in it in order to prevent its moving in the vise. This simple expedient costs little to make, but its use will speed up the riveting and make it a pleasanter job for the riveter.—CHARLES H. WILLEY. Turning Gloves Doubles and Trebles the Wear N work where cloth gloves are neces- sary to protect the hands from rough surfaces, etc., it will be found that one glove often wears out first — generally the left one. To give a larger percentage of wear, when the left glove is almost worn through, turn the gloves inside out. The former right glove will fit the left hand, and vice- versa. The gloves can now be worn till the left one is again almost through. Then, by slashing the palm in each glove, they can be reversed so that the back of the glove comes on the palm of the hand. ; In practice I have found this to give between two and three times the ordin- ary wear of gloves; and when a work- man uses three pairs a week—as many did in one place where I worked—it amounted to a saving of many dollars @ year.—NEAL BROWN. New Stomachs for Old in 48 Hours By R. S. Thompson HOUSANDS of people who suffered for years with all. sorts of stomach trouble are walking around today with entirely re-made stomachs—stomachs which have been re-made in from 48 to 72 hours. They enjoy their meals and never have a thought of indiges- tion, constipation or any of the’ serious illnesses with which they formerly suffered and which are directly traceable to the stomach. And these surprising results have been pro- duced not by drugs or medicines of any kind, not by foregoing substantial foods, not by eating specially prepared or patented foods of any kind, but by eating the plainest, simplest foods cor- rectly combined! These facts were forcibly brought to my mind by Eugene Christian, the eminent Food Scientist, who is said to have successfully treated over 23,000 people with foods alone! As Christian says, man is what he eats. What we take into our stomachs today, we are to- morrow. Food is the source of all power, yet not one person in a hundred knows the chemistry of foods as related to the chemistry of the body. The result is we are a nation of ‘‘stomach suf- ferers.”’ Christian has proved that to eat good, simple, nourishing food is not necessarily to eat cor- rectly. In the first place, many of the foods which we have come to regard as good are in reality about the worst things we can eat, while others that we regard as harmful have the most food value. But perhaps the greatest harm which comes from eating blindly is the fact that very often two perfectly good foods when eaten at the same meal form a chemical reaction in the stomach and literally explode, liberating dangerous toxic poisons which are absorbed by the blood and circulate throughout the system, forming the root of all or nearly all sickness, the first indica- tions of which are acidity, fermentation, gas, constipation and many other sympathetic ills leading to most serious consequences. And yet just as wrong food selections and combinations will destroy our health and effi- ciency, so will the right foods quickly create and maintain bodily vigor and mental energy. In my talk with Eugene Christian, he told me of some of his experiences in the treatment of dis- ease through food—just a few instances out of more than 23,000 cases he has on record. : One case which interested me greatly was that of a young business man whose efficiency had been practically wrecked through stomach acidi- ty, fermentation and constipation, resulting in physicial sluggishness which was naturally re- flected in his ability to use his mind. He was twenty pounds underweight when he first went to see Christian and was so nervous he couldn’t sleep. Stomach and “intestinal gases were so severe that they caused irregular heart action and often fits of great mental‘depression. As Christian describes it, he was not 50 per cent. efficient either mentally or physically. Yet in 24 hours, by following Christian’s suggestions as to food, his constipation was relieved, although he had formerly been in the habit of taking large daily doses of a strong cathartic. In five weeks every abnormal symptom had disappeared—his weight having increased 6 lbs. In addition to this, he acquired a store of physical and mental energy so great in comparison with his former self as to almost belie the fact that it was the same man. - Another instance of what proper food combina- tiens can do almost overnight was that of a man one hundred pounds overweight whose only other discomfort was rheumatism. This man’s greatest pleasure in life was eating. Though convinced of the necessity, he hesitated for months to go under treatment, believing he would be deprived of the pleasures of the table. He finally, however, decided to try it out. Not only did he begin losing weight within a few hours, regaining his normal figure in a matter of weeks, but all signs of rheumatism disappearing, and he found the new diet far more delicious to the taste and afforded a much keener quality of enjoyment than his old method of eating, and wrote Christian a letter to that effect. But perhaps the most interesting case that Christian told me of was that of a multi-mil- lionaire—a man 70 years old, who had been traveling with his doctor for several years in a search for health. He was extremely emaci- ated, had chronic constipation, lumbago, and rheumatism. For over twenty years he had 118 suffered with stomach and intestinal troubles which in reality was superaciduous secretions in the stomach. The first menus given him were designed to remove the causes of acidity, which was accomplished almost overnight. And after this was done he seemed to undergo a complete rejuvenation. His eyesight, hearing; taste, and all of his mental faculties became keener and more alert. He had had no organic trouble— but he was starving to death from malnutrition and decomposition—all caused by the wrong selection and combination of foods. Almost immediately after following Christian’s advice this man could see results, and after six months he was as well and strong as he had ever been in his life. These instances of the efficacy of right eating I have simply chosen at random from perhaps a dozen Eugene Christian told me of, every one of which was fully as interesting, and they ap- plied to as many different ailments. Surely this man Christian is doing a great work. I know of several instances where rich men and women have been so pleased with what he has done for them that they have sent him a check for $500 or $1,000 in addition to the amount of the*bill when paying Him. There have been so many inquiries from all parts of the United States from people seek- ing the benefit of Eugene Christian’s advice and whose cases he is unable to handle per- sonally that he has written a little course of les- sons which tells you exactly what to eat for health, strength and efficiency. This course is published by The Corrective Eating Society of New- York. These lessons, there are 24 of them, contain actual menus for breakfast, luncheon, and dinner, covering every condition of health and sickness from infancy to old age and for all occupations, climates, and seasons. Reasons are given for every recommendation based upon actual results secured in the author’s many years of practice although technical terms have been avoided. Every point is explained so clearly that there can be no possible misunder- standing. * With these lessons at hand it is just as though you were in personal contact with the great food specialist, because every possible point is so thoroughly covered that you can scarcely think of a question which isn’t answered. You can start eating the very things that will produce the increased physical and mental energy you are seeking the day you receive the lessons, and you will find that you secure results with the first meal. This, of course, does not mean that com- plicated illnesses can be removed at one meal, but it does mean that real results can nearly always be seen in 48 hours or less. If you would like to examine these 24 little Lessons in Corrective Eating, simply write The Corrective Eating Society, Department 63, 443 Fourth Avenue, New York City. It is Not necessary to enclose any money with your request. Merely ask them to send the les- sons on five days’ trial, with the understanding that you will either return them within that time or remit $3.00, the small fee asked. The reason that the Society is willing to send the lessons on free examination without money in advance is because they want to remove every obstacle to putting this knowledge in the hands of the many interested people as soon as possible, knowing full well that a test of some of the menus in the lessons themselves is more convincing than anything that can possibly be said about them. Please clip out and mail the following form in- stead of writing a letter, as this is a copy of the blank adopted by the Society, and will be honored at once. CORRECTIVE EATING SOCIETY, Dept. 63, 443 Fourth Ave., New York City You may send me prepaid a copy of Correc- tive Eating in 24 Lessons. I will either remail them to you within five days or send you $3.

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So ores:

i it i A Rate 20 Canes a Word, Pai in advance. i ON A My Hu VE TIO} bad ADV. | mi LON mi (a ii rT “d : ' i (ADVERTISER iu iW iH} l hdl ER a |

El 1 i : um = ft a 10% Discount for Six Insertions. ‘i ‘ te i is Nc | | | RTI ; SIN alt ‘2 lil) st

hs April issue closes one 20th

AUTOMOBILES AND ACCESSORIES

AUTO Motors amd : Both water ae p—Franklin— Michigan—Everett—Bot raoaled Motors 500 eo cach and up. Bosch Miagnetoe- $10.00 each and up —Presto Tanks $5.06 ‘olls $3. rs $5.00— Electric Head Lam; eimeda” os a $3.40—M: Horns $2.85. _ ite *_ ain List second hand au > sccessories Johnston, Pittsburgh,

GOING to ty my geo o-. depend u your knowledge of the business started right. com potent ad advice ven by one wae knows. Douglas West 39th Street, New York. CONVERT your bicycle into a motor-cycle * aa cost Sapeaes Shaw

by. using Shaw Motor Attachment. Mfg. Co., Dept. 180, Galesburg, Ka gt thigh for automobiles are in a demand. We have special Automobile Department charge of — who are in touch with demands oftrade. Write for illustrated le Book, ‘“‘How to Obtain a Patent.” View tor J. I Evans & Co., 172 Ninth, Washington, District of BATTERY awvigags Sm pose bis big poate. City currents or gas engine operates. Hoberts, Troy, Ohio. INSYDE Tyres, inner armour for Automobile Finn] prevent punctures and double mileage of any tire. Li fits. free. American Accessories Co., Dept. 7-A, Cincinnati, Ohio. TIRES At Wholesale—Send F tires and tubes. Lowest prices on earth. Box P, Oelwein, Iowa.

Prices on guaranteed Overton Tire Co., * textbook. Headquarters AVIATION MOTORCYCLES, BICYCLES, SUPPLIES-

THE American Sciool of Aviation announces a new cor- respondence course in Mec! cs of Aviation: A thorough ning in practical aeronautics. American School of Avi- ation, Dept. 18 1863, 431 South Dearborn Street; Chicago. PATENTS wanted in Aeronautics. U. 8S. — oe

subjec Write for our book, “‘How to Obtain Patent” Victor J. Evans & Co., 179 Ninth, Washington, permet = Columbia

Learn aviation, motor mechanics and oe bull uliding: Earn $1.00 to $240 an hour when skilled. Wonder- ful future. Big government Write. Moler Aviation School, 105 South Wells. C cago, Illinois. “CHICAGO Aero Works—Chi icago—Great construction sirpliane blueprints BUILD that new lane now for the coming fiying se: son. Write for ks “L” and bargain motor. Send 12¢ in stamps to America's oldest aeronautical supply ia Heath Airplane Company, Chicago. WELDING WELDING Plants, $25,00 to $300.00. Designed for all porous. Small cash payment, vbalanse three to six months. ret A as or and should have one. Bermo Welding ma A True Story Well Told!

PR ge mo ge auto-tires is a growing ens. oe Easy to learn. instruction book, Plants $50 to $300. Details free. Equipment Co., 302° 8ih Street, Cincinnati, Ohio. >

Saeed Ge siden’ ‘Seapped-poeeld ee anemone. yuaran " D on a Vv Motorist Agents wanted. Write today. Give aize ot f tires. oe poe & Tire’Co., 842 Grand Avenue, Kansas City,

VULCANIZE on Anderson’s Famous Vulcaniser. See our advertisement, page 125. HYDRONIZER—Insures clean = yen. consumes car- bon, saves saves repairs, and is easy to sell. Money back guarantee. Fits all cars. Fords do 34 miles to gallon. ‘Thousands in use. ave attractive proposition for energetic and pense gy nee ene, oe Write for free literature. Frien- ae Company, 2933 West Lake Street, Chicago, lllinois. ENORMOUS demand; Sell Tankii; Modern auto-fuel; teed; 100 to 200% profit. power Tankin system — Adds tremendous power. T: Cleveland,

TIRES—Double ae Guaaaiae for ood service. Big Extra heavy 30x3 tire, %, $7.00; 33x4, Sax, $10.00; 34x4, “310. 75; 36x44, $13 .00; 37x5, $14.00. Big sa ant. d tubes . ‘Trade gs on sizes ani in’ your old tires. , +t, to dealers. O. D. orders. Send = now. Max West 48th Street, New York. ENGINES, carburetors, magnetos, all repair parts. py tires, tubes. Low eg 3 Haviland Supply, Seventh Avenue, New k City. a ge mm i fuel, no nag wy ts guaranteed. Write Piston Ring Company, Baltimore, 3 FORD ACCESSORIES |

No mystery, plain or booklet. No-Leak-O Maryland.

: ee Dees Hoey te CAS Wee wah om now lie abs aan Use chea) eS Vv raee high, Attach it gon ft yoursel | eB on agents. "Money back Tggh Friction Carpureter Oo, 0 Medion, Devon SUNLIGHT for Fords! Bright all —— with ie nem od: 508 Lorton 'B ‘building . Chicago, “FORD valve removing tool. a ye agg Automatically locks. Guaranteed. 7 or your dealer. Tu-Ford Valve Tool BE tell Place, Bay City, Michigan. SEND us $1.00 and we will send you postpaid an “Aeco™ coil box protector for your Ford car. gg AQ aa Equipment Company, 103 Lyric Building,

ELECTRICAL with blue pris print, iS cont cents. SS Bath, INVENTORS. Send sketch and description of your invention for advice regarding patent protection. Twenty years experience. on patents is sent free on request. All communications strictly confidential. Write Talbert —e > paca Lawyers, 4675 . Washington, D. C. inn yee Sf Sonny on prostate booklet gland disorders, see ad under ‘For Men and Women.” The Electrothermal Company, 102 Geit Building, Steuben-

Popular Science Monthly, 225 West 30th Street, New York, N.Y. Gentlemen: I regard Popular Science Monthly as one of the best mediums in which I have advertised in the . last four years, and wish to state that my business has doubled since two years ago. And this is the result of the same advertisement, used all the time, which shows the wonderful improvement and cir- culation of your magazine. Very truly yours, WIiLuiaM R. Barstow. This is the general tone of numerous letters received weekly from satisfied and successful advertisers in every part of America. It Pays! That’s the only important thing a prospective advertiser wants to know. And no one is bet- ter able to emphasize this fact than the man who has used, and is. using, space in these columns month after month—year after year. More than three hundred concerns are repre- sented in this issue and fully 90% will con- tinue to use space without omission. For further information address Classified Advertising Manager, POPULAR SCIENCE MONTHLY 225 West 39th Street, New York City.

TRADE SCHOOLS

HILES Wate and Engraving School, the largest uipped rc —— or 17 Market Street, and best San Franc

BIG money arta ae Learn scenic painting, sign painting, decorating, oe ee. peperhanging, graining, marbling. Sho Catalogue free. Chicago Painting “School. isi” North, "Wells Street, cago.

DUPLICATING DEVICES

“MODERN” Duplicator—a Business Getter. $1.50 up. 50 to 75 copies from pen, pencil, t iter; no glue’ e gelatine ae 30 days’ . You need one. Boo J. V. Durkin & Reeves Company, Pitts- burgh, Pommsytveate. MODELS AND MODEL SUPPLIES

TO avoid mistakes, inventors should have correct models made helore dling for patent. Write Adam Fisher Mfg. Co., 183E, St. Louis, M' Missouri.

sockets, “Te CSTRATED —, ee gg - 4 GL bouth

MAKE your er eT Tomer Sim: , but - emg instructions, 25¢" Freligh, 3010 North Kedris, Chicess <r eee ness. Get started failure depend wu

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““WE make working models for inventors and — for demonstration, and carry a complete stock of brass and model es. Bend for catalogue, The Pierce odel Works, 3405 Avenue, Chicago, 5

RUBBER STAMPS

“RUBBER stamps—stamp for catalog. Box 458, Middle- town, New York. 114

MOTORCYCLES all makes, $25.00 up. New bicycles at big reduction. Second hand, $8.00 up. Motors, mee attachments. Cycle motors. ‘Smith motor wheels, ete., $20.00 up. New parts to fit all makes carried in ‘stock’ pease hand parts good as new 50% discount. Expert epairing, On magnetos, generators, transmissions. ey overhauled $10.00 u Henderson motors our spec Write for big pene n bulletin. American Motor or Ons Company, Dept. 3, Chicago.

CONVERT your wieoee into a saoterereio at small cost by, wane using Shaw Motor Attachment. Janes free. Shaw tg. Co., Dept. os. “Galesburg, Kansas WANT to sell ahead motorcycle of yours? I pave a method that has sold many. Write today for details; a postcard bs - do. . W. Coutlee, 225 West 39th Street, New York y.

TRANSFER name plates. Send for price list. G Decaicomanie Mfgrs., Jersey City, New Jersey. ake

BIGGEST Bargains in New York—Motorcycles, bic: cles and supplies; write for list. Haviland Supply, 2306 Seventh Avenue, New York City. BARGAINS in used Harley, Excelsior, Heneenee and Indian motorcycles; condition guaranteed—$40.00 to $250.00. New and used bicycles $10.00 to $60.00. Write or bulletin. Charles A. Merkel, 1€2 North Clinton Avenue, Rochester, New York.

MANUFACTURING

HAVE you an oo to develop, a machine to Beir KD) e product to be manufactured? Do you need spec ery-to reduce the cost of your ; process ora Peat fp mode . built, tools, dies or any kind of machine work? If so, send us 8 card for our illustrated booklet for manufacturers and inventors. Central Machine Works, 1911 North 12th Street, 8t.. Louis, Missouri. SPECIALTIES of all kinds manufactured for market, Write Adam Fisher Mfg. Co., 183F, St. Louis, Missouri,

MISCELLANEOUS

STAGE career offered you. Experience unnecessary. Send stamp for instructive booklet ‘‘All About Vaudeville.” LaDelle, Station 153, Jackson, Michigan. INDELIBLE Ink makes checks unalterable; Fountain Pens 100%, efficient. Liquid enough for Pint, 25c coin. John Acker, 15 East 40th, New York. ELECTRICAL Tattooing Machine, $3, $5, and $7, Catalogue = See. J. H. Temke, 1019 Vine. Psm., Cincinnati, O:

GRANDFATHER'S CLOCKS

GRANDFATHER'S Clock Works $5.00. Build your own cases from our free instructions. Everybody. wants a hall clock. You can make good profit building artistic pte 4 for your friends. We replace worn-out works in old ocks with works having chimes at money saving Write for folder describing the most — hall clock ever sold at $25.00. Clock Co., Nicetown, Pennsylvania.

SHOP EQUIPMENT AND MATERIALS

YOU Make UmakeM Lathes. You make UmakeM Work Benches. You make UmakeM Novelties. For Material and outfits address UmakeM, Twenty UmakeM Building, Fifth Avenue, New York. TOOL Chests for Mechanics, Handsome, lined oak and leather; guaranteed. $6.75 up. Agents and dealers wanted. Write—Tucker “‘The Tool and Chest King,’’ York, Pennsylvania. .

MOTORS, ENGINES, MACHINERY

SMALL Motors and Generators: 1000 Ney Motors i. 5 Generators from bankruptcy stock—H. A.C. $18. —% H.P. $30.00. Battery C Set Myers New outfits all sizes, $30.00 each and up. C ting & Moving Picture “arc Generators $10.00 each up. ee for all phases of current. Immediate Delivery. Gan 4 prices. Write for late Bulletin. Johns- ton, West End, Pittaburgh, Pennsylvania. BLUE Prints, Gane. Small Engines, Steam, Gas, Circulars, Stamp. Universal Gas Motor Company, Monad- nock Block, Chicago. GUARANTEED electric motors. Illustrated supply list free. Hyre Electric Company, 629-RT South Dearborn Street, Chicago. don lag= = motors, engines, castings. I buy, sell, exchange. rite: Dunlap, 248 Meyran Avenue.’ 'Pitts- burgh, ah CHEMICAL SERVICE

CHEMICAL analyses; formulas; manufacturing prob- lems solved and developed; patents and trade-marks. National Laboratories, 407 Ouray Building, Washington, District of Columbia. TELEGRAPHY

es. est and largest sc Catalog oy Dodges Institute, Second Indiana. BOATS AND LAUNCHES

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« @@ermer oir @F wermi sewii@dg-@e--.«+ se - Serie * aS meet: e+ bE se eee ’ Te BRO PRt | Bt | ek Siatl ve lf Mare 1919 . Flash Pistol Ignited by a Motor Vehicle Spark FTER having experienced all the A exasperations with which flash- light photographers are familiar in the form of flashes that failed to explode, flashes that exploded prematurely, and others, I have made for my own use a flash pistol that never fails. The NN pistol consists {it | merely of a HEN long - handled IH powder-pan itis into which is threaded an ordinary gas- engine spark- plug, aswitch, and a length of lamp-cord by which it is connected with the igni- tion system of my motorcycle. I use the motorcycle for going about the country, so I always have it with me; andI can take pictures several hundred yards away from the machine by simply laying out a sufficient length of electric cord. FLASH POWDER, oe SPARK PLUG Pus = ‘| BUTTON Diagram of flash pistol This shows the apparatus set up ready for use The lamp-cord is double-stranded. One wire connects the body of the pistol with the ground or body of the machine, The other wire connects the spark-plug of the powder-pan with the terminal wire from the magneto of the vehicle. The trigger on the handle of the pistol operates the switch that closes the circuit for send- ing the ignition spark into the powder. The instant the trigger is pulled, bang! goes the.powder. A premature explo- sion is impossible, for the pistol cannot be fired until the circuit is closed.—JOHN EDWIN Hoaa. How to Make a Simple Soldering Fluid OLDERING pastes and liquids can be purchased ready for use, but when not available some other means must:be provided. The follow- ing formula for a soldering fluid is made of materials which may be found in any laboratory. Saturated solution of zinc chloride, 5 parts OM 5 5 we of otuten = ee OS a a eee PRINTING, ENGRAVING,:MULTIGRAPHING EDUCATIONAL AND INSTRUCTION CIRCULARS—1000, = 100 words or less, $1.00; additional thousand, 50 cen 1000, 6x9, 300 words or less, 00; additional thousand, “1. 25, 1000, 9x12, 600 words or ess, $6.00; additional thousand, $2.00. 1000, 12x18, 1200 ae or less, $10.00; additional thousand, $4.00. Printed on 50-pound white book paper, black ink. Get our estimate on your printing. A. H. Kraus, Kraus Building, Mil- waukee, Wisco! nsin. GOOD Printing at low pe ces; 1,000 good letterheads, envelopes, cards, billheads, labels, circulars, $2.50; samples free; catalogues, book lets . and circulars our specialty. Ernest L. Fantus Co. 523 S. Dearborn St., Chicago, Ill. 100 CARDS, Business, Fiera or Social, also imita- tion leather card case, for-60 c . F. Devaney, Print- ing, Heataving, Rubber Stampa, 31 Middle Street, Geneva, ew Yor 100 Bond Noteheads, 4 lines, and 100 envelo repaid 1.00. Southwestern, 1413-B Berendo, Los ‘Angeles. . ACTUAL at ae Letters, heading black, body purple 100, $1.15; 500, $2.00; 1000, $3.25; 5000, ‘$12 ae Letter Shop, 409’ Chestnut Street, Milwaukee, Wis- MULTIGRAPH Letters build business. Most econom- ical and effective advertising. Printing. Addressing. Low rates, careful work, service. Multigraph-Peerless Letter Company, 241 Fourth Avenue, New York. NEW large catalog of attractive Gummed Labels and advertising stickers free. Royal Label Company, 414 Cherry, Philadelphia. MR. ADVERTISER: If you knew as much “oy the pulling-power of Popular Science Monthly as ad- vertisers represented in its columns, your eames would be in this space. We will be glad to give you some in- eee information about this department. May we? . Coutlee, 225 West 39th Street, New York City. ADVERTISING SERVICE “BUSINESS-BUILDING letters, advertisements, circu- ars, booklets, written at attractive rates. Results guaran- So Criterion Service, Dept. 1, West New York, New ersey.” GOING to advertise? Success or failure depends upon your knowledge of the business. Get started right! Com- petent advice gladly given by one who knows. Douglas Wakefield Coutlee, 227 West 39th Street, New York. 100 copies successful circular letters, containing powerful pumnces arguments and selling ideas; no two copies alike. Wri . H. Hoffman, 506 Orange Street, Newark, New ja lig YOUR advertisement in the classified columns of the Electrical Experimenter, Science and Invention, will reach the very class of men you seek. Circulation 100, 000 net. Rate 7c word. The Electrical Experimenter brings positive results. For proof, pierens Classified Department, 233 Fulton Street, New Yor ADDING MACHINES WONDERFUL Adding Machine seven columns —_ ty, only one dollar. Adds and multiplies as fast as the fingers will move. Thousands being sold through demon- stration. L. J. Leishman Company, Dep’t L., Ogden, Utah. MINUTES pay dollars demonstrating new $10.00 ad- ding machine. Wonderful invention. Adds, subtracts, multiplies, divides automatically. Work equals $300 machine. Five-year guarantee. Tremendous demand everywhere. Liberal profits. Write quick for trial offer and protected territory. Dept. O, Calculator Corporation, Grand Rapids, Michigan. FORMULAS & TRADE SECRETS DON’T HESITATE! —When in necd of definite and reli- able data concerning any trade formula or industriai process consult us. We are ever on the alert and -close:y following the development of the industrial arts in all its branches. Each formula or process furn‘shed by this bureau is supple- mented by detailed instructions for its manipulation, there- by doing away with any gu sswork on the part of the inex- perienced operator. Wea.so advise you where the ingredi- ents which enter into any proccss can be obtained. The Standard price for each process or formula issued by us is thirty-five cents. Letters of inquiry welcomed. Write us now. Industrial Methods Bureau, 320 Fifth Avenue, New York, New York. 50 FORMULAS 10c. Catalog 2c. Bestovall Laborato- ries, 3311-PS., Belleplaine, Chicago. PROSTATOLOGY is our free booklet on prostate gland disorders, see our ad under ‘For Men and Women.” The Electrothermal Company, 102 Colt Building, Steubenville, Ohio. WILL furnish a typewritten, guaranteed Formula or Trade Secret for any purpose for only 25c. State exact requirements enclosing coin. Raymond, 13545 Central, Cleveland, Ohio. TOOLS AND SUPPLIES BROWN and Sharpe and Starrett—complet2 stock at manufacturers prices; terms to suit. Also fine tool chests. Responsible agents wanted. Chas. E. Tucker & Son, ‘The Tool and Chest King,’’ York, Pennsylvania. LABORATORY EQUIPMENT CHEMICALS, latest prices. Complete experimental, weighing, titration, and blow-pipe laboratories. Outfits, apparatus and supplies. Consult us before buying. Clar- ence Appel, Mathews Avenue, Knoxville, Pittsburgh, Pennsylvania. EXPERT chemical and pharmaceutical service. For- mulas furnished, processes developed, produets duplicated, analyses ‘made, technical ativice, etc. Address W. A. Konantz, 530 Hampshire, Quincy, Illinois. AUCTIONEERS AUCTIONEERS make from $10 to $50 a day. Free eatalog. Missouri Auction School, Kansas City. TYPEWRITERS AND SUPPLIES . LARGEST stock of Typewriters in America. Under- woods, way under manufacturer’s prices. Rented any- where, applying rent on purchase price; free trial. Instal- ment payment desired. Write for catalogue 11. Type- writer gs ny (Estab. 1892). 34-36 West Lake Street, Chicago, Illinois STUDY bacteriology, public’ “health, and - sanitation. Exceptional opportunities. Remunerative positions, In- otmpy studies. Day and oe courses. Part work May be done at home. Write f formation. Chicago Hospital College of Medicine, 3832-N, Rhodes Aveuuve, PROSTATOLOGY is our free booklet on pr disorders, see our ad under “For Men and a Women’ Th one Electrothermal Company, 102 Colt Building, Bteubens CAMERAS, PHOTOGRAPHY, SUPPLIES MAIL us 15c with any size Film for development and 6 velvet prints. Or send 6 negatives any size pt 15¢ for 6 prints. 8 x 10 mounted enlargements 3 Prompt, perfect service. —— Photo Finishing Co., ‘212 Beil ‘Avenue, Roanoke, Virgini: FILMS developed free! Prints 2 53c 3c. Postcards 3c. 8x10 enlargements from negative, 30c; 4,:$1.00. Prepaid. Regular prices, 24-hour-service. Guaranteed. No stamps. Get list. Emil Sprauer, Hamilton, Ohio. OUR Regular Prices, Prints 3c Each. Devious 5c Roll. Any Size. One trial that’s all we ask. You'll come back for more. Photo Service Shop, 929 McMillan, Cincinnati, Ohio. MOTION PICTURE BUSINESS FREE TO Writers—a wonderful era" oe of money- making hints, suggestions, ideas; the A B C of successful story and play- -writing. ‘Absolutely free. Just address: Writer’s Service, Dept. 6, Auburn, N. Y. WRITE ytnesiors: $50 each. Experlence unnecessary; details free to beginners. Producers’ League, 194, St. Louis. ELECTRIC Arc Generator halves expense. Your engine operates. Easy terms. Hoberts, Troy, Ohio. PHOTOPLAYS Wanted. Big prices paid. You can write them. We show you how. Free particulars. Rex Publishers, Box 175, F 11. Chicago. COMPLETE motion picture projecting outfit for schools, churches, kos etc. with three reels of film and curtain, $95.00. J. V. Mulry, 4557-59 Cottage Grove Ave., Chicago. GOOD income nightly on small investment. Buy com- oe guaranteed moving picture outfit direct: from ‘manu- ——— and save money. Easy payments. No experi- ce needed. Catalog free. National Moving Picture Co., Dept, PE, 537 South Dearborn Street, Chicago. AUTHORS—MANUSCRIPTS WRITERS: Stories, poems, plays, etc., are wanted for publication. Literary Bureau, 117, Hannibal, Missouri. WRITE for newspapers and nn Sa cer Big Pay. Ex- pettence unnecessary; details ee. Press Reporting Syndicate, 400, St. Louis. SEE Here! We want your ideas for photoplays and stories! Criticized Free. Sold on commission. Send for ease, emneatee Sales Company, Dept.100, Poughkeepsie, ew Yor . PHONOGRAPHS AND SUPPLIES BUILD your Zuoneereee “Perfection” high quality spring and electric Motors, Tone Arms, Reproducers. Wonderful results. “Big saving. New Catalog and buildin; instructions mailed for ten cents. Indiana Phonograp Supply Co., Indianapolis, Indiana. LITERARY SPEECHES, essays, distinctive advertising letters, pamphlets, and special "articles prepared for all occasions. 500 words $1.50. Gertrude Sanborn, 778 Farweli Avenue, Milwaukee, Wisconsin. MUSIC AND SHEET MUSIC SONG Writers: Submit your song-poems now for free examination and advice. Valuable booklet explaining our original methods of revising, composing, copyrighting and facilitating free publication or outri.ht sale of songs, Sent Free on oe request. Learn the truth from a reliable successful concern. Satisfaction guaranteed. Knicker- bocker Studios, 168 Gaiety Building, New York. WRITE the Words for a Song. We write music, guar- antee publisher's acceptance. Submit poems on patriotism love or any subject, Chester Music Co., 538 South Dearborn Street, Suite 111, ‘Chicago. WRITE the words for a song. We revise poems, write music and guarantee to secure publication. Submit poems on any subject. Broadway Studios, 121C Fitzgerald Build- ing, New York. MR. Song Writer: Before investigating any other propo- sition, investigate ours first. Submit poem today; examined free. The Kolker Harmony Studios, 4106 Lancaster Avenue, Philadelphia, Pennsylvania. WRITE a song—Love, mother. home, childhood, patri- otic or any subject. I compose music and guarantee publica- tion. Send words today. Thomas Merlin, 238 Reaper Block, Chicago. FOR SALE AND EXCHANGE PROSTATOLOGY is our free booklet on prostate gland disorders, see our ad under ‘‘For Men and Women.” The ae Company, 102 Colt Building, Steuben- ville, oO. DOGS, BIRDS, PETS BREED Canaries—profitable pastime. Particulars free. Bird Farm, Lynnhaven, Virginia. STAMMERING STAMMERING cured—quickly, . permanently, and privately. Write me personally for Free Soin of ay Ham — “How to Stop Stammering.” 8S. E. Robbins. Stammerers Institute, 246 Huntington Avene, " Bonton, Massachusetts. NEW, rebuilt and slightly used Typewriters $8 up. Portable Machines $10 up. Write for our Catalog 25R. Beran Typewriter Co., 58 W. Washington St. Chicago. 115 ST-TUT-T-T-TERING and Stammering cured at home, Instructive booklet free. Walter McDonnell, 59 Potomac Bank Building, Washington, D. C.

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ee ee ee TRESS, oe SSS TRICKS and heat’ “ger Big catalog 5c, ‘ Twenty greenbacks—10c ee 111 5 South Irving, Chicago. i Pa tricks oom nd illustrations. Cues 106., Hornmann Magic Co., Sta. 17, Dept. 42, 25 Mulberry Street, New York City. FOR MEN AND WOMEN BOOKS AND PERIODICALS WHAT do ‘ou want to know about chemistry or law? vital to to the student,.the experimenter, the Experts question ‘or The Kent System, Department A, Cambridge, INSTRUCTION Book (for shop use) on Veepiing aR er Shs $1. er at graeme Company, 368 8th Street, PROSTATOLOGY is our free booklet - jaumate gland rders,-see our ad under ‘“‘For Men and . - ae Electrothermal Company, 102 Colt Building, Steuben- le, oO. INDIAN Baskets—Wholesale and retail, Catalogue. Giiham, Highland Springs, California. USED Books. Bargains. Catalog. Higenes, K-2441 Post. San Francisco. (Books Bought.) “SEXUAL Philoso: ."" 12c. Clear, specific, authorita- = a es. Fred B. Kaessmann, Law- rence, M. BE a detective. Excellent opportunity, good pay, travel. Write ©. T. Ludwig, 424 Westover Bidg., ‘Kansas City, Mo. CORNS—Get them. out with the Root. Bailey’s Corn Solvent will do it. 30c stamps. Mikol Company, 701 Fillmore, Buffalo, New York. CATCH Fish Trip! information for stamp. George Julian, Albany Aibany Building , Boston. PROSTATE dwg: sufferers should have our free book- showing a new pene these N use by physi- . Easily used by mdence absolutely confidential. Company, 102 Colt Building, Steu- ey fe ’ BIG senor amon ee eed pt tine. Field of ” practice soo Ex tional OBE al opportunities for women. Write to “Howard System uth Dearborn Street, Chicago, Illinois. GOING to -yytag Success or failure eons business. Get started Com your knowledge of the advice ~ by one who roan Douglas akefield Goutine 2 est 39th Street, New York. FOR BOYS AVIATION Speedster from cle ory wees you need ee oes Nore ite. New high speed tv ention. Com- plete plans, 25c. Aerocar, Racine isconsin. REAL ESTATE—FARM LANDS OOKS for real live ple. Lists free. J. P. Sheridan, ai? East 151st Street, New York. “NATURE Book’’—facts every married and engaged person should know; 35c. Central Company, | 699 Ninth Avenue, New York. PATENTS FOR SALE akon war is a for the twentieth century window porch scree State rights or royalty. Patented. Nelson 484 Prospect Place, Brooklyn. WE have a few practical money-making pevensions for a 7 trade. Adam Fisher Mfg. Co., 183B, St. Louis, CLOTHES line cover. Prevents soiled clothes. Florence Washburn, Norwich, New York. FOR INVENTORS 600 Mechanical Movements, also illustrations and expla- nations of 50 perpetual motions. My book, Inventors’ Universal Educator, 4th edition, tells how to procure sell a patent for your new invention. ‘“—opo" and other costs. Covers the matter from A to bound. Con Mechanical Movements greatly assist inventors—sugg new ideas that — prove ~f great aid in ecting in- ventions. Tells how to select an attorney i as valuable information a hoes — agents and Bred G. Dieterich, 681 Ouray sDuliding. Washington, D THE Electrical Experimenter Classified Columns bring itive results. Circulation 100,000—rate 7c word. For ormation address Classified Department, 233 Fulton Street, New York. PATENTS. Write for free illustrated guide book. Send sketch or model and description for free opinion of its —— nature. Highest references. Prompt pktention. easonable terms. Victor J. Evans & Co., 156 Ninth Washington, D. C. INVENTORS—We specialize in manufacturing new, patented articles, make models—dies—and do experi- mental work. Modern Tool & Manufacturing Co., Dept. E., Opera Place, Cincinnati, Ohio. Pag ganged farms—i7 states—$10 to $100 tools, cro) a often included to settle quickly. Write for big illustra’ talogue. Dept. 12, E. A. Strout Farm Agency, New York. FREE book of Florida facts. If interested in Ficida, before visiting or > in this wonderful state of fragrant flowers sunshine, write Lake County Land Owners’ Association, No. 205 Lioyd Street, Fruitland Park, Florida, photographs and een conservative facts concerning this State. py yt best land in Florida. This boo eit ete SS best and why. The mem at the tion are not to give CALIFORNIA little forme, near Los Angeles, for sale. Easy payments. Write E. R. Waite, Shawnee, Oklahoma. THE Real Estate Educator—A Book for hustling real mo’ uid: 0} and other information. 256 Panes Cloth, Price, $1.50. Book Songemen. Popular Science Monthly, 225 West 39th Street, New York. HAVE you a practical invention to sell outright or place = royalty? Send details to Adam Fisher Mfg. Co., 183 A . Louis, Missouri. PATENTS promptly procured. Send drawings for actual search of U.S. = pe eee, Moderate fees. Write for free ae t boo George P. ae. patent lawyer, 82R O1 —s¥ Building, Washington, D. C. INVENTORS join National Institute of Inventors, World Building, New York City; membership society 1900 strong; will help you A owe ne develop, finance and market, your invention. lutely no charge. Write or et. INVENTORS. Send sketch and description of your in- vention for advice regarding patent pro on. Twenty years ee Our hand-book on patents is sent free on request. All communications strictly confidential. Write us today. Talbert & kas hee Patent Lawyers, 4691 Talbert Bldg. Washington, D. C MR. ADVERTISER: If you knew as much ‘-~y the pulling-power of Popular Science M he ad- vertisers represented would be in this space. e will be teresting information saan this department. _y we? D. W. Coutlee, 225 West 30th Street, New York City. INVENTORS! bm have a proposition that will prob- ably interest you. Inquiries invited. The Wakefield En- gineering Company, rs A F St., N. W., Washington, D. C. PATENTS. Fees payable monthly instalments. Free books and advice. Frank Fuller, Washington, D. C. GAMES AND SRE ARENT NEW Patriotic Playa, Recitations, Entertainments for -time Benefi audeville Sketches, oe fo Tapleatm, Make-Up Pp Goods. Large Catal . T. 5S. ison & 26, Chicago. PROSTATOLOGY is our free booklet on prostate gland ers, see our ad under “For Men and Women.” The a Company, 102 Colt Building, Steuben- ville, 0. - PATENT ATTORNEYS 470 70 Hignth Beg New York. TRICKS, Puzzles, Jokes, T Games, N —— = | Tilusiops. Large 1918 C he Coke hheninl Coe ‘om- pany, Dept. ge: itomaig rs” PORTEMANTEAU Theatres constructed. Scenery for bBire. Catalog.’ eS bi play a 2 soe ot tame. ILOQ) g stamp for ost any: oO. pag hg Bigelow Street, Peoria, PICTURES AND POSTCARDS JOIN Live Postcard Club. Membership Papers 1 Harvey Teeple, Decatur, Indiana. ° - DO you ? if Tecate plceares IS Cleesabess RAE hang fame please. o. W. BEAUTIFUL, ere pictures. for dens, club- etc. Send dime ae sample, — lists, prices, ete. If worth ha’ —— are sure to please. you rane pictures Saginaw, M FIVE prettiest women cards, hand colored, 25c. Durso, EVERYTHING in post cards. Up-to-date lists sent free Worth-while samples 25c. Ment choice erred. Mutual Supply Company, Bradford, Pennsy! eon, Dessiitel octored colored postcards of famous Colum- tends over seventy years. It pays to employ an attorney =s re pone p= pot is a bad > ia, 8 ners. e are t publishers of the Scientific am: and all % us are described without cost in the Scientific American. = invention is thus wae to the attention of thousands telligent readers es interested in such matters. \—-> like publicity in any 0 other manner would cost ou! — times the patent fees. Our Hand Book on Patents plication. Munn & Co., Patent Attorneys, a 624 Woolworth Building » New York, and 625 F St., Wash- ington, D. C. PATENTS, Trade Marks, Copyrights. Prompt, personal, reliable service. Over 30 years’ active practice: no for terms. Book free. Address E. G. Siggers, Box 1, N.U ashington, D. C. . Building, W: PATENTS. — for free illustrated guide book, ‘‘How to Obtain a Patent.”” Send sketch or model and nd description ~ aoe opinion = its a. nature. — — ‘erences. m: & Co., cg cee “Washington, pa” Cc. — . = PA i lose Ps oo. Send for blank form “Evidence f Conception’ be signed and witnessed. Establish your rights bef wg Ff - your eee to anyone. Form and information eo Patents 3 } & Allwine, 232 Ouray Building, Washington, D -YOUR idea wanted. Patent your jevention. T'll help = market it. Send for 4 free eons, Be vice free F buyers, jundreds of ideas wanted, etc. ae qovertané free. Richard B. me, ~ ay Owe Owen Bldg., » Washington, D. C., or 2276Z Wootwerts Siags PATENTS—Herbert Jenner, patent Attorney and me- expert, 622 F St., Washington, D C. I report rt free obtained through us. Adam Fisher ita! Greoa Multnomah Stamp Company, Port- PATENTS: Our practice before the Patent Office ex- of charge if a patent can be had and its tS § Send for- Popular Science Monthly Where Am [? The Aviator Asks and Radio Answers By Theodore E. Hedlund N the last moments of hostilities [a British and American air- men perfected a radio direction- finding apparatus which promises a new era in long-distance flights. By its use aerial navigators can determine ‘their exact position in the heavens, night or day, and regardless of weather. The pilot and crew might be hope- lessly lost and hundreds of miles off their course; yet this simple apparatus would solve their difficulties in a few minutes’ time. It was intended for long-range night bombing raids in Germany, but the ending of hostilities prevented its use in that direction. Now the instruments will be employed for commercial and scientific travel in the skies. The Proposed Transatlantic Flight New impetus should come to the proposed transatlantic flight from the United States to Europe as a result of this discovery. The benefits of the radio achievement will also be reaped by those who are planning exploration trips over the north polar regions. Perhaps our aerial mail service will also improve with regard to distant mail routes, which have never proved successful. Many night bombing ships had been sacrificed during the war as a result of bad weather and fog when pilots were unable to see landmarks and their maps became worthless. The helpless crews floundered along in the night air, and eventually had to make forced landings either on hostile ter- ritory or in. neutral countries, where they were interned. ' To overcome such predicaments, wireless experts and navigation officers began a study which is now completed and does away With the visual method of navigation. Instead of taking bear- ings by known landmarks, the bear- ings are determined from known wire- less stations by means of radio, and by this system the pilot can ignore both stars and ground and steer a true course at all times and in all sorts of weather. Two coils of wire at right angles to each other are placed in the fuse- lage of the ship to pick up wireless calls from any land station. The larger the coils the more energy they pick up, and they are only limited in size to the dimensions of the fuselage. Calls can be received from thousands of miles away without any traveling aerial or antenna wires. All that is needed, in addition to the coils, are the usual wireless instruments, an amplifier and tuning box. Mfg. tg. Cont 83C, St. Louls, Missourl 116 This scheme of direction-finding = ae tet lk eee eee, ee eee , a"

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~ March, 1919 is best described by work done in ‘experimentation. A plane left the und at night, and its pilot and navi- gation officer paid no heed to direc- tion, time, or compass. After an hour in the air, neither knew his whereabouts or general location. The navigation officer then tuned in his instruments and picked up wireless calls from the powerful station at Berlin. Usually Berlin was sending out press matter to smaller stations throughout Germany at night. Determining the Compass Direction By swinging the two coils described, the wireless wave from that station either decreased or intensified in en- ergy. This is known as “tuning When the coils were adjusted to the point of greatest efficiency for receiv- ing, the navigation officer read a com- pass attached to the apparatus, and determined the exact compass direction from which the call was heard. Making correction for the known curvature of that wireless wave, he drew a line on his map from Berlin at the angle given by the compass. This placed the position of the air- craft as somewhere on that line. Taking bearings in the same manner by tuning in with wireless calls from the Eiffel Tower, Paris, and with London, the navigator soon deter-. mined his position on that line by an old system of triangulation. Special charts were used in place of ground- maps, and at no time was it necessary for either the pilot or the navigation officer to see landmarks or study the stars. A Year's Work on the Idea The first idea that radio could be used in directing aircraft was conceived about a year ago. Since that time Americans have worked both with and independent of the British on this subject. The use of direction-finding by wireless in planes was on the point of being perfected when the armistice was signed, and missed its mission as far as night bombing raids were con- cerned. But transatlantic flying and north polar exploration trips will be much simplified by using this system of navigation. An American officer who should be given credit for much accomplished on this important ap- paratus is Lieutenant Herbert Bas- sett, of Paw Paw, Michigan, an aerial radio officer who worked on the dis- covery together with the Royal Flying Corps and the British Navy. He was stationed at the field headquarters of the American night bombardment section in Sussex, England. While these tests were in progress, other experiments were being con- ducted in wireless telephony, making possible communication between planes in the air. These discoveries have been perfected to a point where there “PATENTS and Patent Possibilities’ is a valuable book- let which tells all about patents, and is full of interesting information for inventors, Frequent causes of failure are explained. Sent free together with form ‘‘Proof of Concep- tion’’ to be signed and witnessed for your protection before filing application. H. 8S. Hill, 929 McLachlen Building, Washington, D.C. INVENTORS. Send sketch and description of your invention for advice regarding patent protection. Twenty years experience. Our hand-book on patents is sent free on request. All communications strictly confidential. Write us today. Talbert & Talbert, Patent Lawyers, 4624 Talbert Bldg., Washington, D. C. . M. E. MILLER, Ouray Building, Washington, D. C. Patent attorney, mechanical and electrical expert. Best quality of work and results. Moderate charges. Advice free. PROTECT your invention. Personal service. Send sketch for honest advice. J. Reaney Kelly—912 Woodward Building, Washington, D. C. TO Market Your Invention, you must get in touch with the proper persons. Let me show you how to doit. D. W. Coutlee, 225 West 39th Street, New York City. LACEY Patent-Sense. See page 112. “The Book the Inventor Keeps.” PROSTATOLOGY is our free booklet on prostate gland disorders, see our ad under “For Men and Women.” The oa Company, 102 Colt Building, Steuben- ville, 0. PATENTS promptly procured. Send drawings for actual search of U. S. patents. Personal service. Moderate fees. Write for free patent book. George P. Kimmel, patent law- yer, 82R Oriental Building, Washington, D. C FORTUNES from patents, are made only from a good invention strongly protected. Send sketch or model and $5 for thorough search and honest opinion of patentability. I give personal, conscientious and expert service. Lester = Sersent, Patent attorney, 524 Tenth Street, Washing- on, D. C, INVENTIONS patented; trade-marks registered; labels, prints and publications copyrighted; reasonable fees; cor- respondence solicited; detailed information free; booklets. Jaynes & Jaynes, 701 Kellogg, Washington, D. C yi PATENTS. Booklet free. Highest references. Best re- sults. Promptness assured. atson E. Coleman, Patent Lawyer, 624 F Street, Washington, D. C. JAMES C. Lyles. Patents, trade-marks and copyrights. 734 Eighth St., N. W., Washington, D. C. PATENTS procured; reliable service. ‘‘The Last Word a eel free. Sanders, 2 Webster Building, Chicago, ois. PATENTS! Foremost Metzger, Washington, D.C. word free. Write now. AGENTS AND SALESMEN WANTED $1,006 per Man per County; Strange invention startles world—agents amazed. Ten inexperienced men divide ,000." orstad, a farmer, did $2,200 in 14 days. Schleicher, a minister, $195 first 12 hours. $1,200 cold cash, made, paid, banked by Stoneman in 30 days; $15,000 to date. A hot or cold running water bath, equipped for any home at only $6.50. Self-heating. No-plumbing or water- works required. Investigate. Exclusive sale. Credit given. Send no money. Write letter or postal today. Allen Mfg. Co., 476 Allen Bidg., Toledo, Ohio. REMARKABLE Stretching Cuff Links—permit cuffs to be raised over elbows quickly, without unbuttoning. Durable, invisible, everlasting. Big profits for competent district agents selling direct to wearers. Flexo, P. 8. Sheboygan, Wisconsin. $40 to $100 a week. Free samples. Gold sign letters anyone can put on windows. Big demand. Liberal offer to general agents. Metallic Letter Company, 400 North Clark, Chicago. AGENTS: Quick seller—big profits. California Rose- beads selling like hot-cakes. Women wild about these beads. Write today. Mission Bead Company, X2819 W. Pico, Los Angeles, California. GOING to advertise? Success or failure depend upon your knowledge of the business. Get started right! Com- petent advice gladly given by one who knows. Douglas Wakefield Coutlee, 227 West 39th Street, New York. 1919 LINE of Globe Transfer Initials for monogramming automobiles just off press; exceptional profits to agents and salesmen. Samples and display board 10c. Particulars free. Globe Decalcomanie Mfgrs., Jersey City, New Jersey. PROSTATOLOGY is our free booklet on prostate gland disorders, see our ad under ‘‘For Men and Women.” The Electrothermal Company, 102 Colt Building, Steubenville, Ohio. LIBERTY Policy, the very latest in Insurance, covers all accidents and sickness. Every occupation insurable, men and women, 16 to 70 years. $5,000 death and $25.00 weekly costs $15.00 yearly. Thrift Policy, paying half benefits, cost $7.50 yearly. Special benefits covering farmers. Policies also at $10.00 and $5.00 premiums to meet low-rate competition. Leather wallet enclosing $100 Identification Certificate with each policy. Attractive agency openings with continuous renewal commission. As- sets $2,696,258.27. Founded 1907. Southern Surety Com- pany, 308 Walnut Street, Philadelphia, Pa. AGENTS: Big profits. Best and cheapest window letters made. Easily applied. Dime brings five samples. Particulars free. Staibrite Company, 1115 Second Avenue, New York. AMERICAN Military Styles are all the rage in men's tailored to measure suits this season. Easiest to gell: everybody wants them. Far ahead of all others in real class and beauty. Lowest prices—less than common Tready- made suits. ur agents are coining money. You can a or eee —— re full ee we and sample es and patterns. merican Woolen Dept. A-51, Chicago, Illinois. . — QUICK selling, newly patented, universally useful in- vention. Sells any. time, anywhere, anybody. . Week's supply can be carried in pockets. Costs 3c each, retails for . Fine sideline opportunity. Send 10c for sample 5 agen ssp H. G. Martin, 51 Cliff Street, New York. WINDOWEDGE—Stops fattling windows; keeps out cold; worth dollars, sells for dime. Big seller. Moore Com- pany, 413 Jerome Avenue, Cincinnati. MEN of Ability—To represent manufacturer direct, selling Sales and Order Books. Liberal commission. Wirth Sales Book Co., Dept. P. 8.; Chicago. NINETY Per Cent of Your Calls Turned into. Sales. Wonderful Enthusiasm “Follows Every Demonstration!’ Write at Once for Full Particulars of Our Line of Eradium. (Luminous) Articles. Startling! Mysterious! Everlasting! Novel! They Shine in the dark. Crucifixes, House Num- bers, Bulbs, Match Boxes, Pictures, Switch Plates. Sole 1 Manufacturers... The Pioneer Corporation, 1263 W. 63rd, Chicago. AGENTS—Steady Income.- Large manufacturer of Handkerchie‘s and Dress Goods, etc., wishes representative in each locality. Factory toconsumer. Big profits, honest goods. Whole or spare time. Credit given. Send for par- tee eee Mfg. Co., 24 Main Street, Brooklyn, OUR New Inventions earn you stexdy Mmcome. Can- Vassers, County Rights, Salesmen and Promoters write. Adam Fisher Mfg. Co., 183G, St. Louis, Missouri. AGENTS: Big money selling great household invention. Sample 25c. Particulars free. Webster & Company, 2935 North Clark Street, Chicago. " LEARN profitable legitimate rofession for home work or travel. No catch game. igh-grade honest deal. {reuters for stamp. DuLand Walton, Prairie City, DURING spare time sell your friends our hosiery and underwear for their own use. Many salesmen are. making $5.00 a week upwards without. interf with regular line. C.& D. Company, Dept. 10, Grand Rapids, Michigan. WERE You Ever Offered a Grocery Store? Our Pr 1- tion Is Better. Let us tell you how you can handle Flour, Canned Goods, Provisions, and entire line of groceries, as well as Paints, Roofing, Stock, *oods, Automobile and Machinery Oils and Greases. No rent to pay. No invest- ment in stock. Large orders taken from samples. Goods of guaranteed and proven quality. ing experience not necessary. Vi rofitable work for ‘‘workers.” Address Hitchcock Hill Company, Dept. 220, Chicago, Illinois. Reference: Any bank or express company. INSYDE Tyres, inner armour for Automobile Tires, prevent punctures and double mileage of any tire. Liberal rofits. Details free. American Accessories Co., Dept. 7, Cincinnati, Ohio., AGENTS—Make a dollar an hour. Sell Mendets, a potees patch for instantly mending leaks in all utensils. ample package free. Collette Mfg. Co., Dept. 467, Amsterdam, New York. MEN and Women—Become independent—own your business, experience unnecessary selling our $6,000 Acci- dental Death, $30.00 Accident, $25.00 Sick Weekly Benefits: $10.50 yearly, half amounts $5.50. Guaranteed steady in- come from renewals. $250,000 deposited Insurance De- partment. Registration Dept. S., Newark, N. J. ENORMOUS profits applying transfer monograms to automobiles, trunks, bags, etc. Easily and quickly applied to anything. No cxpersenes: No paints or laborious hand rt Samples free. Wagner Company, Corona, New VULCANIZING auto-tires growing profitable business. especially now. Easy to learn. Instruction book $1. Plants $50. up. Catalog free. Equipment Company, 372 8th Street, Cincinnati, Ohio. YOU can make good durable paints and varnish, 35¢ allon. Emmelmann Bros. Mfg. Company, Dep’t A, ndianapolis, Indiana. “‘“RADIO” Luminous Paint for resale. Big demand—big — Trial can, 50¢ delivered. American Luminos oducts Co., Huntington Park, California. MAKE and Sell Your Own Goods. Machinery unneces- sary. Expert Chemists advise. Special attention to be- ginners. Write for Formula Catalog. Elmer Mystic Com- pany, Washington, D. C. AGENTS: New Kerosafe Stove. Burns coal-oil. No smoke, no odor, no dirt. Safe. Cooks a meal quickiy. Ideal for ironing. Not sold in stores. Quick seller. Easy to demonstrate. * Sample furnished. Write for agency. Thomas Stove Company, 4661 North Street, Dayton, Ohio. AGENTS: 200% Profit. Wonderful little article. Some- thing new; sells like wildfire. Carry right in pocket. Write at once for free samyie. Albert Mills, Mger., 6147 American Building, Cincinnati, Ohio. ENORMOUS profits selling Duo Guaranteed Products. Easy sales at every house. All or spare time. Outfit Free. bf quick. Duo Company, Dept. H66, Attica, New , York. AGENTS: New invention puzzles world; wonderful chemicai cloth; one rub over rain, snow blurred auto wind- shield; street-car or engine window, presto! glass stays clear 24 hours; can’t blur; agents making $120 weekly. Security Mig. Co., Dept. 87, Toledo, Ohio. KEROSENE Burners Cook and Meating Monroe, : for Furnaces, —— Economy Mfg. Company, 616 West SALESMEN—City or Traveling. Experience u - sary. Send for list of openings and full particulars. Prepare in spare time to earn the big salaries—$2,500 to $10,000 a@ year. Employment service rendered Members. National foemen's Training Association, Dep’t 126 C, Chicago, nois. MINUTES Pay Dollars, demonstrating new $10.00 Adding Machine. Wonderful invention. Adds, subtracts, multiplies. Work equals $300 machine. Five-year Guaran- tee. Sells everywhere. Splendid profits.. Write Quick for trial offer and protected territory. Dept. O, Calculator Corporation, Grand. Rapids, Michigan. EASY, pleasant work for Mechanics, Shop Men, Clerks, during spare hours, will add many dollars to their salaries. Also want persons who can give full time. Big wages assured. Novelty Cutlery Co., 27 Bar St., Canton, Ohio. WONDERFUL Adding Machine—Seven column capaci- ty—retails for one dollar. Sells itself everywhere. ost offices purchase several. Sensational agency proposition. L. J. Leishman Co., Dept. F, Ogden, Utah. 117 WORLD'S record on war books. Also life of R 72 books in 1 day; 57 in 11 hours; 45 in 3 hours. Gus copyrighted Patriotic Insert for soldier's prowereee tary record sells war book on sight. troduction by se Ga given "acy wtih Campi bane wih Bat aid. Cr ven. quick. Sam’ Ptic insert free. H. L. Baldwin Company, 314 1; Rocketeller Building, Cleveland, Ohio. ERWOOD & Underwood, the world's leaders in Illustrative material are now making rong at — contracts for the sale of Visual Instruction Eq arn peop on libraries “Die eee aX. -C nee | & Underwood, Dept. P. 8., ai? 5th Avenue, New York. NEW invention—Big seller. Deviin Company, P.O. Box 433, Newark, New Jersey. , MAN in each town to refinish chandeliers, brass automobiles, by_new method. $10 daily without © or experience. Write Gunmetal Company, Avenue 2, tur,

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AE: ee Ss Eerie GE SETS BE Sa Tepe a i cee i AB ape de ee pro arene Ay eae: dams aiie 29pm 0 tpn Gs ple oe * THOUSANDS women-giris. AGENTS—som ething new. _ House-to-house article out. a warned : ndia fiber house broom. Outwears three ordinary broo Sells $1.25, costs agent 65c. Get in line With a live one. ordan, Pittsburg, ie $36 first day. ean Eg out of every five calls. Write Cambridge, ge Manufacturing Company. tor sam mle. Pe Pee West me Bae 549 West PATENTS. Write for Free Illustrated Guide Book. aE sketch or model for free a. of its patentable Highest References. mpt Attention. Reason- able Tr ‘Terms. Victor J. Evans & Go. mt 4 Ninth, Washington, District of Columbia. PROFIT selling Jubilee Spark Intensifier. Ban- ts Ba trouble. Sells lik ike wild-fre. Exclusive net Welt quick quick. Jubilee Mfg. Company, Omaha, District Organizers with Fofd Car to eal Simplex Ford ng Memerin The oy a starter with a tion of making good. y Ford Car Selis for $15.00. Write for agency. Box. $60" 8 Simplex Mtg. Company, Indiana. > WORLD'S tastent selling wanted; write today. ag a, 3 Oller AGENTS: = pookeng Sener ha Sy 7 each. ‘Carter, Tenn: 4 do same. Write sample offer ing, plan; exclusive Verritory. Sample — by May pened 1 Dost ies paid, Condon, Importer, 12 Peerl Street, Boston, ti chussetts. BIG profits selling oye na s a food flavors and Consurvo. for or beking wi thou Se. Fletcher Produc- tion Company, 317 South Clinton. cago. AGENTS:._ Big and free automobile introducing new gasoline sav cture yoni rand other eco iwey, 190, Station F- Louisville, Kentucky. apogee greatest history of world war; complete details of great battles; 600 pages; 100 striking “itustra~ tions; only $2.00; 50% co’ on. Life of Theodore Roosevelt no t Order free outfits today; send 10c — on ebet HJ. Smith, Publisher, 1104 Ludington LIFE 0 ore Roosevelt (Introduction. by -ex- President Taft). History of world J by March. $5.00 per hour selling these two books. mal nee terms. Bot! outfits , State choice. Historica) Company, req ; i fol hunting, ——_ 3 agency. ny areas Stephenson BUSINESS OPPORTUNITIES ENTER a new business. — > $3,000 to $6,000 yearly jin professional. fees making and fitting a foot specialty, everywhere with all = trade you can attend to; ed; no goods to buy; Laboratory, 15 Back B EXPERT Chemist mil furnish * Form and te Secrets in all lines. Lists free. W.L. Cummings, Ph. 217 Standart St., Syracuse, New York. CHORALEON Phonographs—sSpecial agency proposi- tion selling from your home. No soliciting or canvassing. Big Saeebar ase Write for home agent’s special offer and con- proof: We also supply complete material for build- he 3 Sianopraphs at home. Choraleon Phonograph Com- pany, 2203 Monger Building, Elkhart, Indiana. “WANTED—Every ambitious man or woman to learn show card writing. Enormous demand. _ Big profits. Wages while learning. Particulars free. J. D. Schoolfield, Greensboro, North Carolina. THE “Reliable Plan” will help you to earn money at home in spare time. Men or women. Complete plan 10c. Edward B. Maher. Dover, New Jersey. BRANCH Manager wanted for old established Chicago concern. We furnish full stock of goods, advertising matter, and equip store completely, in good location, all at our ex- pense and pay you .00 a week salary, in addition to lib- eral share of the =— your store earns. Work can be started in spare t' No investment or previous experi- essary to secure this position. If Fane | are a hustler and want an opportunity to make $5000 a year we want you and will pay you well from vine start. Send me your application today. 8. Levy, Manager, » i acamaaead 657, Como Building, Chicago, Illinois. MAKE Die-Castings. Sketch, Sample, Booklet and proposition 12c. R. Byrd, Box 227, Erie, Pennsylvania. I MADE $30 a week, easy money, evenings, home. Free — explains. Sen d stamp. Al Scott, Cohoes, New TaCR fdea wanted. Patent your invention. you market it. Send for 4 free books, list of patent buyers, hundreds of ideas a, ete. . Advice free. ae advertised free. Richard Owen, Patent Lawy: 44 Owen Bidg., Washington, ». C., or 2276Z Woolworth Bldg., New York. BE a_ detective. travel. Write C. T City, Mo. eng Yearly in your backyard. No ginseng, mushroom dope. Newideas. Investigate. Particulars free. C. Metz, 313 East 89th, New York. I'll help Excellent op rtunity, good . Ludwig, 424 pay, estover Bldg , Kansas HELP WANTED MEN wanted to make toy soldiers, army, navy and other toys. Home workers on small scale, manufacturers on large seale. Greatest chance for industrious pert for indepen- dent business. Enormous demand and future in ‘“‘American- made-toys. This new American Sork vatands out con- pn one Factories have been established, people trained, made with energy and success. ealers don’ t want to handle any others except “American-made.” We fixed prices. Experience and more made complete $3.00 up. Booklet and in- Manufacturing Company, ‘ormation 32 Union Square, New York. MEN—Age 17 to 45. Experience . Travel; make secret investigations, reports. Salaries, expenses. ng ey Detective Agency, 321, St. Louis. og Photo Experience unnecessary yen ed by League, 194, St. Louis. EARN $900 to space Fa Year. Government Railway Mail, Post Office and ot) “exams” coming. Prepare under Former Civil Service Say Book free. Patterson Civil Service School, Box 3019, Rochester, N. Y. =e detective. Excellent opportunity, = Pay, ag wie ¢ T. Ludwig, 424 Westover Bidg., Kansas City, Mo. rrors 4 enormously profitable business. Booklet free. RAISE Guinea Pigs for us. We buy all you raise. Pay better than poultry. Contract, particulars, booklet how to raise free. Cavies Distributing Co., 3141 Grand Ave., Kansas City, Missouri. DOLLAR addressed UmakeM, Eleven UmakeM Build- ing, Fifth Avenue, New York, brings designs, tools and materials for starting UmakeM business at home. FREE—3 Months to get acquainted; devoted to news and opportunity. The Western Miner, 2541 W. 37th Ave., Denver, Colorado. F a ae exploit practical inventions. Trade for prop- rm companies. Sell county rights. Adam her Nite. Co. 183D, St. Louis, bennonteea —Exc ic met opens P. Barstow, 514 23rd Street, Oakland, California. eg age ahd is our free booklet on prostate eg disorders ad under ‘For Men and Women The Electrothermal Company, 102 Colt Building, Steu- benville, Ohio. ASSIST in the reconstruction of Belgium. The Belgo- American Corporation, Ltd., 329, High Holborn, London, W. C. I. England, wishes’ to make arrangements with American firms for pushing their business in Belgium .and in = Belgian Colony of the Congo. Write and send cata- ogues. AGENTS wanted to sell chewing gum ball vending ma- chines. 59W Drexel Building, Philadelphia, Pennsylvania. BE a Mirror Expert, $3-$10 a day: spare time home at first; no capital; we train, i u making and silvering — French method. Free prospectus. W. F. Derr, .. 579 Decatur Street, Broo N. Y. Di fae el exe 5 to-vand out how you can ow you can learn at home to su y the big demand for finger print experts in banks, big factories, detective limited offer—send for free illustrated k. ‘Tells about finger prints. University of Ap) Science, Room 9203, 1810 Wilson Avenue, Chicago, Illinois. INVENTORS. Send sketch and description of your invention for advice ne cree patent protection. Twenty experience. Our ha’ on eae sent fee juest. communications strictly confidential. us today. Talbert & a Patent Lawyers, 4101" Tate bert Bidg., Washington, D ee oy tay ae Be one. ‘Write Amer- iean School of Criminology, Detroit, Michigan. PROSTATOLOGY is our free booklet on prostate gland disorders, see our ad under “For Men and:Women.” The ville. Obl Company, 102 Colt Building, Steuben- 0. WRITE for newspapers Reporting Syndicate, surright = ‘ane Press 44 eeatenens peace o men- to $1500 year. ee iy Paid Common education sufficient. List positions free. Write peer. Franklin I a, Dept. B50, Rochester, N. Y. GET a “4 position sg us. Position or 16 ‘to 60, needed in Washington and 7% ky — no years of “recon tion” ahead. for Civil 5 ed — gH easy h ns, hi; salaries. Our free Book RG give svt Servic list of positions Bae? a it. Wash- District of Columbia, | een Building, Wash- oo Men—Become automobile experts. $35.00 week. Learn earning. Franklin Inst BS803, Rochester, New York. ee letters land big positions. iculars. — ly placed 7 Parti ly placed. Write for Burns, 509D West 174th Street, New York. sacl “CIVIL ed yp Lan Career." New book, just out, gives for the Government. Op- I 16 to *. & in Baas big after-war femeeee ea at Civil Service reall y means. Written who ows. Sen money back if = : Model Printing Company, Dept. C13, Washington, D ved. RAILWAY mail clerks wanted. Men 16 to 40. $1100- Srerydes, “Uap cueties woe "Piatt Dept. 'C. - BO, Rochester, New York. ag > the y - We'll coach you quickly by Joell dng appointment. Perma- - BECOME independent in the home manufacturing busi- ness; unlimited possibilities. Stamp, details. McDoul, ms 480, Johnstown, Pennsylvania. RIDLEY, 68A Clifton Place, Jersey City, will design you a “Dandy” letterhead for $1.00. STAMPS AND COINS OLD Coins. Large Spring Coin Catalogue of coins for sale free. Catal uoting — paid for coins, ten cents. William catalan. 101 mont Street, Dept. P, Boston, | Massachusetts “FREE, 60 different stamps including Newfoundland, China, Japan. Mexico, etc., to applicants for our high grade a vals. nd 3c’ stamp for return postage. The gewood Stamp Company, Dept. M., Milford, Conn. STAMPS. 61 All Different, 3 cents. Mention paper. ae Stamp Co., aoa. Ohio. $2 to $600 id for hundreds of old coins dated before ee Gone 1 a Tat once for new illustrated coin value 4x7. It may mean your fortune. Clarke & Co., Conn ouies Box 76 LeRoy, N. Y. PACKET “A” 100 varieties foreign stamps, 20c. F. J. Pope, Charlotte, Vermont. i 17 Varieties , Stamps 20c. List of 7000 varieties, — riced stamps free. Chambers Stamp Co., 111C, Nassa' Br New York City. CALIFORNIA gold, quarter size, 27c; $4 size, 53c; dollar size. $1.10. U.S. ent piece and catalogue 10c. Norman Shultz, King City, Missou-i. STAMPS, 50 Varieties, Transvaal, Brazil, Peru, Cuba, 40c. 60 dif- Mexico, ete., and Album, 10c. 1 000 mixed ferent 8., 25e. 1, binges. 10c. List free. I buy stamps. C. Stegman, 5949 Cote Brilliante, St. Louis, Misso STAMPS! 50 different gm (large See China, Jamaica, Portugal, Venezuela, etc., 10c; 1,000 well mixed, 40c; 106 varieties U. 8., 50c; 1,000 hinges, 0s: Agents wanted; 50% I buy stamps. . Dover, Groves. hilnout. 105, China, etc., Stamp Dictio , list 2c. — 500 illustrations, 3c. ‘Bullard, Station AA, Bosto “SPECIAL” packet 10c. Rare stamps on approval. Sears-Nelson, Oak Park, Ilinois. STAMPS—12 different from warring nations, 10c; 10 different foreign coins, 15c; 10 Dyes y stamps for 10c. Lists free. Toledo Stamp Co., Toledo, Ohio. STAMPS. Set of 10 Different, scarce, including War Issucs, Mexico, y ARH offic'als complete, Chile, Argentine, bin ame ete. large LO every fs a sending ‘0. for age, ‘or e price and approval selec- oo at from 78%, dise’t. Hussman Stamp Co. ept. 55, St. Louis, M nee Valuable ‘Stamps to Applicants; 50% ——- Benj. Forbes, 160 Devilliers, Pittsburgh, Penn- 10 Mexico, ete. free. saaeae. Multnomah Stamp Com- Popular Science Monthly is little excuse for an aircraft to loge its way, rain or shine. - Aerial mail delivery has been handi-. capped in this country because pilots lost their way in fogs and storms, Future delivery of mail by aeroplane, especially long-distance flights, will probably employ radio if the service meets the demands of progress in flying, Aid to Future Explorers The success of radio direction-find.- ing is a boon to aerial navigation at night, when it is important that an aircraft crew should know hourly their exact location and whether or not their courseistrue. Shifting winds then become known and corrections can be made for the ship’s drift. A map becomes worthless for visual navigation when mist, fog, or rain hides known landmarks; and the terse re- ports of night bombing operations during the war, announcing the num- ber of ships that failed to return to the aerodromes after certain long- distance raids; testified to the need of a more accurate means of navigation. The progress made in wireless devel- opment has dispelled the remoteness of the North Pole and brought closer America and Europe, and students of aerial navigation are now convinced that the fear of becoming lost has been eliminated from the minds of those who propose to explore and venture by means of aircraft. Making a One-Man Job of Adjusting Foot-Brakes O adjust automobile foot-brakes single-handed, jack up the rear wheels, one side at a time, while set- ting the band on each wheel; then, with a block against the seat panel and a jack placed in as shown to force the pedal down, turn the wheel and the screws on the brake-band, adjusting it to the proper tension. Make both brake tensions equal. Take up easily = ~~ WOOD BLOCK~ The position that the jack should have for proper brake adjustment one brake-band at atime. By turning the wheel over with the hands the prop- er brake adjustments are easily made. Count the number of clicks in the jack as it is operated for each wheel, and compare them. The wheel re- quiring the most clicks on the jack until the wheel cannot be turned by hand must have its brake-bands tight- pany, Portland, Oregon. 118 ened to equalize them—P. P. AVERY.

Page 105

” Mareh, 1919

Write for the Wilson Sporting Goods Catalog featuring equipment for all basketball, football, soccer, tennis, golf, fishing, camp- j ing, etc. Address Thos. E. Wilson & Co., 701-711 North i Sangamon Street, Chicago.

, CHICAGO, ILL.

sports, including baseball, , Hold the gains of army training! HE high degree of physical fitness attained through military training will give you a great advantage when you re-enter civil life. But you must keep up that vigorous physical exercise to which you have grown accustomed. It will help you win in business, just as it did in battle. The splendid physical condition of the men who are returning from Overseas and army training camps is the greatest object lesson on the value of physical training this nation has ever had. If you—a civilian—have been lax in regard to physical excercise, reform your personal habits and go into training to make yourself as physically fit and efficient as a soldier. : The great problems of reconstruction call for the same energy, effort and enthusiasm that made America the deciding factor in the war. You owe it to the nation as well as to vourself, to be at your best —physically, mentally—so that you may do your part in meeting the new demands. Take up some form of athletic activity. It will strengthen your physical fibre, steady your nerves, add to your reserve of vitality and increase your personal eificiency. Wilson’s Sporting Goods and Athletic Equipment, which has been a big factor in the physical training of our soldiers and sailors, is now available to civilians through leading dealers throughout the United States, eer eee © THOS.E.WILSON & Co. NEW. YORK, N. Y. <<?

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Teor ater Gane tity gap ee Sep ates oo rere == Sag tasks ee ees 255 Se EF SERA SERS SE et Preserve Your Phonograph Records! 7 A—Ordinary Steel Needle, new, B—As the ordinary needle wears down, owing to its taper form, it can no longer fit the record groove perfectly and hasatendency toweartherecord. C—Sonora Needle having parallel sides, ALWAYS fits record groove exactly and lengthens the record life. onor CLSAR AS & OCLEL Semi-Permanent Silvered NEEDLES Replace steel needles! They play 50 to 100 times without wearing out. Use Sonora Needles for mellower tone, greater economy, conven- ience and for longer record life. Loud— Medium—Soft 30c. per package of § At all dealers or write Sonora Phonograph Sales Company, Inc. GEORGE E. BRIGHTSON, President Executive Offices: 279 Broadway, Dep:.z, New York Use Sonora Needles on a/I makes of steel needle records , ‘ THE BOY = for Work and Play with an Ex tion of the or! an on of t of Every-day Electricity. $2.00 Post Monthly, 225 W. 39th Street, New Yorks QUTDOOR life made the Yanks the physical marvels they were in the late war. Stamina, muscle and re- sourcefulness—these-are the result of life in the open. outdoor sports. What’s a camp without an “Old Town”—a dependable carry-all and gaat canteen ride ye are bui y to rough it in rapids, ye light _— to respond to the slightest -touch of the paddlie—easily portable. Shapely in line—a craft to be proud of —and entirely safe. “Paddle Your ‘Own Canoe—and be sure it’s an Old Town.” Write for catalog. : $51 up. Dealers everywhere. Old Town Canoe Co. 1893 Main St. Old Town, Maine Canoeing is king of — Practical Plans of Electrica ~ Transplanting-Boxes of Paper for Early Hothouse Sprouting APER seed-pots are handy, cheap, and easy to make. If seedlings are raised in fire-baked porous flower- pots, the roots are invariably dis- turbed when they are taken to the garden and placed in their respective beds. All this is avoided with paper pots, which are merely sunk into the ground. These pots are especially recom- mended for plants that are retarded by transplanting, such as cucumbers, melons, peppers, etc. This is of still greater advantage with cucumbers, beans, and other plants if-they are placed in the ground at the time other people are sowing their seeds for these A handy transplanting paper box to safeguard the roots of early sprouts plants. Then an earlier harvest will | be assured. Round paper pots can be purchased, 41 but these are not as desirable as the square pots, since the former are diffi- cult to handle, while the latter can be easily packed.—Dr. E. BADE. What to Do With Dirty Crank- Case Oil LD worn-out, grit-filled oil, drawn from automobile crank-cases, clutches, drip-pans, and other sources, need not be thrown away. It may be mixed with coal dust and screenings and used for fuel. A pint or more used with each hod of screenings, mix- ing well so as to make a dry, pasty ' mass, will barely cling together. In this way two otherwise useless prod- ucts may be used as fuel.— RONALD PRINDLE. 120 Popular Science Monthly - Making a Grease-Gun from Potato-Masher ib Raw accompanying picture . shows a home-made grease-gun -whieh. has proved exceptionally Satisfactory . and efficient in handling grease of any compound. This device provides an economical means of injecting grease, besides preventing grease from getting on clothing as often happens when the hand method is used In making this apparatus a potato. masher of the ordinary type was used, the perforated bottom being covered with a sheet of tin. The spout of a discarded oil-can was soldered into a hole previously cut in the wall of the masher near the bottom. You press down on the handle and the cir- cular piece of metal which is attached to it presses down on the grease and forces the grease to come out of the spout.--ERNEST SCHWARTZ. An Adjustable Safety Guard for the Circular Saw HEN a new circular saw was placed in a certain shop, the person taking charge of it immediately planned the safety guard shown in our illustration. It was made of a flat piece of steel a trifle thinner than BLADE IN LINE WITH SAW | | WING NUTS It Illustrating how the safety guard should be attached the blade of the saw, with an arc of a circle cut from hard wood for the guard. . It was attached with a clamp and bolts which were of the wing-nut tvne.—THEODORE J. BECKER

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=a eh V HY Rte Oe mee e~ & P Ss OM “March, 1919 : DontSend _a Penny qhat a bargain you are offered here Bet Sot a cent to send with your order. These strong durable, wonderful shoes, sent to you on just to show you that in spite of advancing of material and labor we ean give you the most remarkable s values. Just gone Ritts dress Statin size ae howt y dey The specially Com ned leather the greatest service under hardest lot only a wonderful weari we nye ag r shoe By too. Yan only. Lace Blucher style. This, bat sii = very shoe you want for real wear. The shoe last ever Co looks fine. Biggest value for the money. 0 13. Send today—just your name ® and address—no money. Pay for the shoes on arrival. Try them o m and see how comfortable they are. If you don . cay this is the biggest shoe bargain — find, or if for any reason shoes are not satisfacto and we will your i money. ure to give size when ordering. Order by No. 14012. -LEONARD-MORTON & CO., Dept. X 897, Chicago SPECIAL TERMS—TEN MONTHS’ & credit on any article selected from the i SWEET Catalog. No money in advance. Ship- ment made for your examination. First pay- ment to be made only after you have con- vinced yourself that SWEET values cannot be equalled. If not ALMA saree wy, a value of? more than you pa a No Red Tape--No Delay Every transaction CONFIDENTIAL. You don’t do justice to yourself and your dollars unless you in- spect our unusual values in Diamonds. Watches, Jewelry, Silverware, Phono- graphs, etc. Send TODAY for SWEET’S newest creation; 7 Fine Diamonds. Set in SWEET De Luxe supe Eagreved a e wd e st Catalog. Write ounting. OOKS e @ $350.00 Solitaire. NOW to Dept. Price $62.50 479-H. THE HOUSE OF Q DUALITY? LWSWEET& . 2 ‘+ si atti soci YORK = 35 MILES PER HOUR s Built by a boy from Juni ts furnished t by ue. A "hs y boy can build | is car. Parts very m4 Send 26 cents for blue pris Of and price list of parts showing how to This build this speedy little car. Car SYPHER Mi 74 ue ve. * OLEDO, OHI How to Carry a Spare Wheel on a Bicvcle SPARE wheel on a bicycle is often very useful when taking a cross-country ride. The wheel should be a rear one with the sprocket, since this can be used for either wheel. Make All ready for a punctured tire a bracket of strap-iron, and attach three leather straps to-hold the wheel in place. The best place to carry this third wheel is above the rear one. There it does not interfere with the rider.—H. W. HAHN. Repairing a Broken Cil-Pump Shaft HE oil-pump shaft on an auto- mobile engine broke at the point indicated in the illustration. The break was caused by the fact that the two projections of the shaft that en- gaged with the lower shaft were too small to stand the strain that was placed upon them. To replace the broken shaft with a new one would be expensive, since the shaft and drive gear were made of one piece of steel. The repair was L-DRIVE GEARS [ i”. l | —" ft) FRACTURE ' le— DRIVE SHAFT = L_ ) a | #— DRIVEN SHAFT | PUMP GEARS ! J —, qr dap tenet — bag | i 1 iL COUPLING LL oo To RIVETED TO SHAFT © cRANKCASE The repaired oil-pump shaft made by using an old magneto coupling that was in good condition. One-half of this coupling having a slot exactly the same width as that of the broken pump shaft, a duplicate part was easy to attach. As the hole in the coupling was too small, it was placed in a lathe chuck and bored out to the proper size. The flange was then pressed on the shaft, and both were riveted together with the aid of a 1-in. pin.—ADOLPH KLEIN. 121 Finger Print Detectives Wanted EN are wanted by the govern- ment, police departments, corpo- rations, banks, institutions and individuals—these men must be trained] Finger Print Men—men who have made this work a profession. Big Salaries and big rewards go to these experts be- cause they solve mysteries that baffle the most experienced ordinary detectives. The finger print clew is one that cannot _ fail because no two people in the whole world make the same mark. You Can Succeed in mastering this fascinating, big money- making profession by studying in your spare time at home. Common school education is all youneed. A brilliant career is before you. Finger print experts travel everywhere, see the country, live in the best hotels and have all expenses paid. There is a crying need for such men right now. This profession is not crowded. Get started at once—right now—and be one of the big men in the field. Get our free book today. Mailthe Coupon Right NOW! Fill in this coupon and mail it right now. i may be the big opportunity of your life, so das t waste another minute. en you send the coupon we will send you our Free Finger Print Book Tells you all about finger prints—the big oppor- tunities in this profession, and everything you want to know about it. Send the coupon now. ‘ ‘University of Applied Science st "Desk 1203 1772 Wilson Ave., Chicago NAL. - Bbuze blero) (@lal cys leony Trained men are in big demand at good salaries by the Signal De- partment of every caphaas railroad in the United States Today the opportunities are bigger and better than ever, RAILROAD SIGNAL MEN can be easily acqu' ath b (ares Write today for Fie Book? Py goa lao aes rales eran eae postcard or send coupon DEP ARTMENT OF SIGNALING : 1810 Wilson Ave., Room 1203, Chicago DEPARTMENT OF SIGNALING Feist 1810 Wilson Ave., Room 1203, Chicago NEMBig «0 000.20 sv0ceveéhcestpilebise Gaieen ane PGE. vio v's 0 sb 0 cebvline btkeeeeee ee eT Oceupation 2 ozs seavececrenceescccesens AOQrO® nutes PES SGNGTy a reas te lcci 4 Hl Please send me Free Book on Finger Prints and. § full information about your course of study. a a | BN GONG 6.0. hs i os ot cnce0cte ces eSeethene cease coed t | e ee ib a vowuvicoctedytdepaicees ebdiu i t @ ° aren Occupation vid @'v b die o'e ORL eee dl weed 4 $90 t0°25 0 aMonte 3 are tl: d th. Be - The training neceseaty te ast planed tech Gi ete ot " on ere send me phocletely free and econ yf in hook the facts. on om this. dar newt Casasd ees lieansion :

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v vit ti) \\4 { i" VOVAN SYA S "OT aaa De gh date “AMAVAV EY Ont OS, Here’s the sen- ‘sation of the bi- ~ cycle world. You never saw such i graceful lines, such ¥ fascinating color combinations,such mag- \ nificent steel construc- ¥ tion. Sold under an abso- lute Five-Year Guarantee. And just think! Black Beauty has 18 Exclusive Features —including Firestone Blue Non-Skid Tires; exclusive notched finger grips; distinctive “B-B”’ sprocket; steel nickeled chain; motorbike saddle, pedals and_ braced handlebar; etc.—well, just send TODAY for our Bicycle Catalog—FREE—and read all about the marvelous Black Beauty. 20 styles! Choose any one. Repair Kit, Tool Bag and Stand FREE Don’t buy an ordinary wheel, when you can get the Black Beauty. And for less money! Wholesale price; factory direct— no middlemen’s profit. See the wheel be- fore paying a cent. We_ship at our own risk: WE PAY ALL FREIGHT. Keep it, orreturn at our expense. Months to pdy—only a small [BE OUR deposit on acceptance, then AGENT $1 a week (or $5 a month). ’ Six months’ accident insur- | WRITE ance free. ; cea SEE SUNDRIES Don’t buy tires, lamps. horns, saddles, parts, supplies. etc., until you see our factory prices. ositively AY Y, the lowest inthe country. (Sample cross-sec- tion of tires free.) Write for Sundries Catalog. HAVERFORD CYCLE CO. (Established 23 years) Dépt. G-56 Philadelphia, Pa. A new detachable plug which pierces insulation of wiring By J. E.. Pettibone Pulling the wire out of the chain in the hanger and at- taching the socket to it TTACHMENT plugs of various kinds have been on the market for years, but these must be used in the regular socket wherever it is placed. The one illustrated differs from the ordinary kind, for it can he attached to any drop cord or rubber- insulated wire at any point, and when removed no trace of the attachment can be found. The advantage oi this device is that the light- ing arrangement is not de- stroyed, and it may be applied and removed almost in a second—much more quickly than a The mm, ’ 7 1 ! mpoeed) ! FIG? FIGS FsG. 3. FIG.6. Cross-section of the parts, showing the glass ball which works the switch when the socket is clamped to the wires 122 Showing in detail the socket attach- ment on the wires attachment complete for clamp- ing to the wires A fan cord run to the socket attachment, where it is clamped to a drop cord globe can be taken out and. a plug screwed in. A cross-section of the at- tachment is shown in Fig. 1, with the base of the lamp in place. - The connection pins are shown at A. These pins pierce the insulation of the wire and make the contact. In Fig. 2 the device is shown attached to the wires, and in Fig. 3 the switch. In Fig. 3, 4, and 5, B rep- resents a spring finger that forces the small glass ball down as the switch is moved from left to right, which in turn forces the spring C into contact with the lamp or plug, thus completing the circuit. When the switch is moved over to turn on the current, the narrow slot D is brought into close contact with the spring snap E, Fig. 6, thus making it impossible to remove the socket from the wires whilethecurrentis on. There- fore no arc is formed to burn the in- sulation on the needle-points. In Fig. 7 and 8 is shown the method of piercing the insulation of the wires. : A Reliable Solution for the Electro-Deposition of Aluminum LUMINUM is at best an uncertain metal with which to make an electro-deposit. The following formu- la, however, has been found to be , quite reliable: Dissolve 50 parts by weight of alum in 300 parts water, and add 10 parts of aluminum chloride. The resultant solution is heated to 200° F. and per- mitted to cool. When cold, 39 parts of cyanide of potassium are added. Popular Science Monthly The One-Second Electrical Plug \ Rae £ FEES wee] oS | ESSE 338s 'T we a2

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ct. m 1in an 1u- 1m int er- cap. for booklet telling ee now - Coaster ana ; TWIT ALIVE Dad Wi awn an Auto Wheel ELL them that [ hould own an caer tied Cras or an — Convertible oo built for theyre the ag mee have roller work, of rod "Whe and tires, and are oval like an auto. re for FREE Felt Pennant iter pon hgh fenirs, mentioning “which wee ge * a beautiful Felt Organize an Auto-Wheel Coaster Club Each member receives a beautiful captain receives a special | AS A ROADSTER This is the famous Auto - Whee! Coaster ---and here is the patented Auto - Wheel Convertible Roadster and = A ae branch. Address, Buffalo Sled Company 157 Schenck St., N. Tonawanda, N. Y. (in Canada: Preston, Ont.) 10,000 Miles \Guaranteed and No Punctures After ten years test by thou- sands of car users, Brictson P noumaticT ireshavesolved meumatio tire problem, Eas riding, absolutelyproof AS A COASTER against punctures, blow- outs, rute,rim cut, ski 1015 W, O. W. Bldg. 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, $2.00, Postpaid. Machine Shop Work—A comprehensive guide to the most approved methodsin modern shop practice, the construction and use of im- — tools and machines, hand tools, the the and lathe tools, the methods of screw cutting, taper and eccentric turning, etc. Leather, 275 pages, 325 illustrations. Price, $1.75, Postpaid. POPULAR SCIENCE MONTHLY 225 West 39th Street New York City MM Pilliod = TOOL CASES EXCEL achinists and Tool Makers tnd them most satisfactory struction, h . greaiamnc ser- vice and price. Booklet oe 19 styles The Pilliod Lumber Co Swanton, Ohio The New Midget Slide Rule has many exclusive features. It Ox \' ‘ subtract, Ko sire Seetedess 3s boar ope Se Blose, sf al angles: BaP roe tres citenioss. Price $1.00 with Your money back i you are not GILSON SLIDE RULE CO., Niles, Mich Regulating the Current from an Induction Coil HEN using the induction coil, instead of the sliding tube ar- rangement, it is often convenient to have a separate regulator to vary the strength of shocks, ete. The instru- ment illustrated will accomplish this result. Its construction is simple, and the materials required are readily pro- curable. Corks with wires are inserted in the ends of the tube after it is filled with water A glass tube about 12 in. long and having a bore of 1 in. is fitted with two sound rubber corks at either end. A short length of No. 16 gage copper wire is run through the center of one of the corks, a long length (about 11 in.) is run through the other, and a ring made at each extremity. After in- serting one of the corks, fill the tube with water, and insert the other _ cork. Wipe the glass and corks dry and make the joints impervious to water with sealing-wax. The greater the dis- tance between the wires in the circuit, the weaker will be the shock from the coil—HERMAN NEUHAUS. Making a Strainer for a Brine-Pipe Line liv refrigerating, plants where seals of the U-type for pans are used, floating debris often enters and pre- vents the flow. Usually strainers are placed in the intake to prevent this, but it sometimes does not stop the entry of dirt, and unless some means is provided there is no way of removing this sediment. The _ illustration below shows how a strainer, or strainers, may be affixed to the bend, made of pipe and fittings, so that the strainer part may be removed and the sediment taken out. A U-type seal used in a refrigerating plant, and the strainer to keep out the sediment The strainer part is made from per- forated metal of medium gage. The holes should not be larger than 1/16 in. Enough holes should be provided so that the flow of the liquid will not be retarded by the presence of the strainer. 123 AT could be more at- tractive to the average man or boy who has the slight- est interest in tools than one or more Stanley high grade Planes? Planes made ‘and guaranteed by a Company who have beén manufacturing Carpenters’ and Mechanics’ tools for over half a century, insure a quality that cannot help but please. Iron and Wood Bench Planes— Block, Rabbet, Router, Plow, Dado, Circular, _ Fillister, Dovetail—in fact Blanes for every wood-working job that calls for the use of such a tool. We can only show here a few of the many styles and designs we make. Catalogue No. 34S tells you something about them. At all Hardware Dealers. MANUFACTURED BY STANLEY Rute & Lever Co. New Britain, Conn. U.S.A.

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Take a Tip from. the Lineman High above the ground, in rain, snow or sleet, the lineman takes his chances for your comfort. His tools must be the ‘best— there can be no doubt, no ques- ] tion, where life is risked. | Red: Devil Pliers REG.V.S. PAT. OFF are his choice. He knows that ‘they are designed right, forged right, finished right; he knows they will not fail him in the emergency. Take a Wp from the lineman. | The tools he uses are right tools for you. He chose “Red Devils” as an expert, knowing } exactly what depended upon | them. Take advantage of his expert judgment. Ask your hardware dealer to show you the models best suited to your needs. Smith & Hemenway Co., Inc. ‘Sales and Export Office: 264 Broadway, New York, N. Y. Factories: Irvington, N. J. “Red Devil’ is the Expert Mechanic's ‘guide to known quality in Pliers, Electri- cians’ Tools, Hack Saw Frames and Blades, Auger Bits, Chain Drills, and Other Hand Tools, all of a class with **Red Devil ’’ Glass Cutters, the biggest sellers in the world. MoroR ; We have 1000 NEW WASHING MACHINE MOTORS. These p} are of standard manufacture'and carry the regular factory guarantee LEB? Shipped in orignal boxes. Complete as cut A Bought from Bankruptcy Stock Suitable for operating Cofier Grinders, Cream Seperators, Bottle Washers, = fe] $1 8-50 Small Lathes, Ete EACH WP, 110 volts, A.C. Va gessie SS” GHAS. H. JOHNSTON - West End - Pitshargh, Pa We are miners and shippers of Crude Asbestos in amy 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. How to Draw Smooth Curves Accurately Placed O draw smooth, accurately placed curves on cross-lined paper, fol- low the method herein described: First plot the curves on a sheet of cross- lined paper, or if it is thin paper prick the plotted points through very lightly on smooth, firm cardboard. Plot a number of points, especially where the curvature is greatest. If the curve is to be used for reading values, do the plotting with the aid of a small read- ing-glass. The points should be so close together that lines ruled with a straight edge nearly trace the curve when the points are joined. ; CROSS-LINED J a PAPER sf PAPER CLIPS \ CARDBOARD TOP AND BOTTOM PIECE CUT I/iG" SMALLER THAN CROSS-LINED PAPER Several curves of the same kind may be easily drawn by this method Having plotted the points, sketch in the curve in pencil, rubbing out and tracing until it is apparently smooth. Then make the best line slightly heavier with a three-H pencil, and carefully erase all the rest. If the curve is on heavy cross-lined paper, cut’ near the curve with a pair of shears; if it is on the card, use a knife. Be careful not to touch the line, but get as close to it as possible. Next, mount a piece of fine sand- paper on a piece of smooth squared stick, and gently go over the curve, wearing it down to the pencil line; or if, on examination, this line is slight- ly out, allow for the error. To be sure the edge is smooth, hold it up and sight along it. Since the finished curve is to be very accurate and smooth, time must be spent in sandpapering. Now, when finished, lay the paper or cardboard curve on the sheet of cross-lined paper you intend to put the finished curve on, getting it exactly in position, and testing by reference to its values at many points. When satisfied that it is correct and that it is correctly placed, draw the curve with one sweep of a three-H pencil 1% j HEHE | if Popular Science Month. along the edge of the cut-out, sure first that there is a sharp point _ on the pencil. ic Now, if the cut-out curve is of Paper. cut two pieces of thin cardboard al. most the shape of the curve, and place them one above and the other below the curve, sandwich fashion, allowin the paper edge to project about 1/16 in. Fasten all three pieces together with paper-fasteners. If the cut-oyt is on cardboard, fasten a piece of car. board below it, a trifle in from the edge. In either case, the mounted curve can be used to trace the curve jn ink, for it is raised from the surface of the lower card. Lay the cut-out in place over the pencil line, try jt over several times with the dry pen to see how it works, then fill the pen and draw it along the line lightly, just pressing it enough to keep it in contact with the cut-out edge, and do not remove it until the line is completed.—ERNEST A. HODGSON, End-Cell Control on Constant Potential Lines N rural districts storage batteries are generally used to supply power to the lighting circuits. Since the voltage of a battery of storage cells will fall of as the cells become discharged, some method must be employed whereby the voltage across the line may be kept constant. A very good and economical method is to cut in and out a certain number of cells at the end of the series, as more or less voltage is required by the lamp load. In the accompanying sketch, S, with all its digits, is called the end cells. As Storage Cells S152 $3 S4 SS So ST Switch arm + supply Asimple switch for cutting outa mains certain numberof storage-battery cells to keep voltage constant the cells become partly discharged and the voltage of each cell falls, the arm of the end-cell switch is moved out toward S-7, thus throwing more cells across the supply line and raising the voltage. In recharging a battery where the end-cell control method is employed, all the cells are at first thrown in cir- cuit. Since the end cells are less dis- charged than the others, they will re- quire only a little charging. As soon as one of the end cells becomes fully charged, it is cut out of the circuit by moving the switch-arm back toward S-1.—PETER J. M. CLUTE. Be Brceesgsacvna Some ev 500- aH Hite 3 5 24 oe (S528 C2 Semen | comms (ese sereevmewceeszece. @ aall'es*

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are r to tage | off ome eby cept hod iber nore amp vith b ST id cell witch 7. ee =. and arm out cells the the | yed, cir- | re- 300n 'ully t by vard ¢ NE KEROSENE ENGINE PRICES Immediate Shipment nes cos opera’ own, Worth mm ore--better built to ea Pine ‘and or to handle, zeta te I ship everywhere in the U.S. delivery, sWsite for my new & BATTERY CHARGING ves... PAYS BIG PROFITS Add to y your present profits by putting in battery chargin ng. Requires no yino oxtra help and no special electrical or mechani- cal experience. With same opportunity as you, many HB owners are clearing $100 to $200 Extra Profit Bt Month Some even more. You can do as well. This H fie ames 1 vd Puts Tye Money-Maker in Your rage np be month ts of at rere oe eo ani me “ily paren pot completely gat poe ; Ses . pomane BROTHERS COMPANY Box S3, Troy, Ohio Steam Vulcanizer | “4 Anderson's Flexible(Conforma- Device, upon which an or- ary monkey wrench exerts of pressure, forces thousands of ies gag rivets pei _ steam system. We guarantee to make practical vul- : out of men" 20 toi years ld, 5 Valeanising Schools in one o' many is will start 0 le to enter our ur cjosest school to he am re shox [sorc re ) ve se Anderson SteamVulcanizer. 8 0, Ande) son method of vulcanizing. TOOL CHESTS If it is chests, we can supply you. That’s our business. Write for Circulars J. M. WATERSTON 81 Woodward Ave. , Detroit, Mich. The Real Metal Solder Largely used by Allied steel sag 3 Wills Bigs Bigg. ments in the World War. Latest necessity for use in home, shop and automobile. Best for wiring. SOLDERAL IN’ TUBES IN TUBES that turns into solid metal by appl ying a little heat. Permanent results.- No acid or soldering iron required. 25¢ per tube. At most hardware or electrical stores. or direct from us, postpaid. CO., Dept. 2, 129 Sussex Ave., Newark, N. J. TOOL CASES ee and Toolmakers wet built and. most pay? tion of Tool Cases on the market We —, direct from factory and please you or refund A Pipe Made from a Joint of Bamboo N a week-end. trip to a camp in the woods, I found that I had left my pipe at home, and I missed it greatly. The camp was so located that it was impossible to purchase one, and I therefore decided to make one. After searching the camp I wan- dered downto the boat-house, and there caught sight of an old bamboo fishing- pole stuck in the rafters of the roof. On examining it, I found that:a piece cut from the butt would make the bowl and a piece from the opposite end would make the stem. By cutting the butt near one of the natural sec- tions that form when the bamboo is A rough and ready pipe may easily be made from the joint of a bamboo fishing-pole and its tip grown, I made the bottom of the bowl. All that remained for me to do was to make a hole and assemble the stem with the bowl. I then had a pipe.—W. E. BARNES. Temporary Repairs on a Leaking Boiler TEMPORARY repair on a leak-. ing boiler can be made by cut- ting out the leaking part. Often this is the only way to avoid a long delay and a shut-down. Though the fuel expense is increased a bit, the saving until repairs can be properly made or new equipment received fully justifies the expedient. In the case of a sec- tional boiler used for heating, it may be found that a section has sprung a leak through a sand hole right over the grates. No kind of plug will keep the water off the fire, but by cutting out the mud drum and steam connections and screwing in plugs, the other part of the boiler may be operated as be- fore. With a leaky tube in a boiler that furnishes steam for power, it is often impossible to shut down during the week long enough to put in a new tube, but a taper plug may be driven in each end of the tube any night; then, if these are made with a hole through the center and a rod long enough to. pass through both and allow a nut at each end, the plugs may be kept secure- ly in place until permanent repairs are made. Such repairs are not to be encouraged; but, in these days of un- usual delays and high production, they help greatly in a pinch, and if well done and the boiler is carefully watched, they can do no harm. 125 Make Machines Cut Their Costs The machine producing its output at lowest cost is the machine you can make most money on—and other things being equal, it’s the machine with a Veeder Counter. The counter-equipped machine delivers work at less cost be- cause you can operate it under a production-schedule repre- senting its best rate-of-work. You can watch the out-put under different operating con- ditions until you develop the maximum—then keep to this point of lowest unit costs by keeping tab with the For recording and checking-up the output of punch presses, metal- stamping and other machines, where a re- ciprocating movement counts an operation, manufacturers use the Set-Back Rotary Ratchet Counter below. Registers one for each throw of the lever, and sets back to zero by turning knob once round. Supplied with from four to ten fig- ure-wheels, as required. Price, with four figure-wheels (as illustrated) $10 (list). The small Revolution Counter be- low registers one for a revolution of a shaft, recording a machine opera- tion. The mechan- ism of this counter will stand a very. high rate of speed, making it especial- ly suitable for many types of machines, and most adapta- ble for experimen- tal work. Will subtract if run backward. Price, $1.75. The Veeder booklet shows just the right counter for every machine that should have one. May we supply you a copy? The Veeder Mfg. Co. 44 Sargeant St., Hartford, Conn.

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PRESS Ea SS STS =< SSE Ree ee =:

Is YoursA —. Quality Kit? The progress you make in the shop is dependent on the quality of work that you do. In order to produce high quality work you must be equipped with high quality tools. Quality Tools Mean Quality Work Therefore, it is to your benefit that the tools you purchase for your kit be accurate, durable and of the highest quality. Tools to suit your requirements It is with this end in view that Brown & Sharpe tools are made. Designed by men who have studied your re- quirements and made by men who recognize the necessity for accuracy and quality. * A Catalog you need We have a catalog for your tool kit which describes our extensive line of machinists’ tools besides containing considerable useful in- formation. Send for your copy of Catalog No. 27 to-day

Brown & Sharpe Mfg. Co. PROVIDENCE, R. 1, U. S. A.

An Exciting New Game . To be: played with a motor and some thread’ ITH a small battery motor.or a discarded phonograph spring motor, or, for that matter, any other form of motive power on a small scale, it is possible to play a most interesting game. Aside from the form of motive power on hand, the only other essentials are a long piece of thread of fair strength and a few pieces of paper. The thread is formed into a continuous belt by knotting the free ends together. Part of the belt is passed over some smooth support, such as a chair-arm or a door- knob, which becomes a sort of pulley. The other end of the belt is wound twice around the pulley of a small motor so as to give it a good hold and keep it from slipping. The belt should be supported between the motor pulley and the support at the opposite end in such a manner that the two strands of thread are parallel and placed about 1 in. apart; then the motor is operated to see that the thread belt moves

An exciting moment in the game, wheré one rider is striving to go “over the . top’’. of . the - other smoothly over its support and around the pulley. The next step is to prepare a number of folded strips of paper or “‘riders,”’ to be placed on the thread as shown in the illustration. If one desires to play a form of war game, these riders are each given the name of some country. They are placed on one thread or the other, according to the side that the rider is to represent. To start the game, the riders are placed at the ends of the belt, and at the desired moment the motor is started at a slow speed. The riders move toward each other only to engage in the center; and then contest each other’s progress.’ If both sides are of equal strength, the riders push back and forth in a most realistic manner; in fact, it resembles nothing so much as a hotly contested, football game, with one side or the other pushing. the op- 126 Popular Science M onthly. ponent back to the goal, only to be swept back again to the center of the field. A victory is scored by the side that succeeds in pushing on to the op- posite end of the belt. It sometimes requires half an hour for one side or the other to score a decision. Youngsters and adults wil] often follow the swaying riders with the same interest that characterizes a football game, especially when each onlooker has picked out one of the riders as his entry. If the players prefer, the riders can be named for various schools or colleges, or given the names of the people who are play- ing the game. . A similar continuous belt system can be used over considerable distances indoors or outdoors for transmitting dispatches, which can be folded and placed on the thread as riders. If necessary, paper clips can be used in order to hold the riders securely in place.— MIRIAM LESCARKOURA.

How to Detect Formaldehyde in Milk Sapna soir pecanas is often used as a food preservative, especially in milk. The following will furnish a simple test for its detection. Dilute the milk to be tested with about an equal volume of water and add a few drops of a ferric chloride solution. Concentrated sulphuric acid should be carefully poured down the inclined test-tube so that it goes to the bottom, as in the well known brown ring test for nitric acid. The presence of formaldehyde is shown by the appear- ance of a violet ring where the two layers of liquid are in contact, when the tube is placed in hot water. This test is a very delicate one, for the presence of formaldehyde is shown in two-hundred-thousandth parts of th solution. 5

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the ‘ide ised ally nish lute ; an few ion. 1 be ined om, test of ear- two yhen This the n in the ’ valve to the cock, turn the valve, and March, 1919 A Home-Made Air-Pump : for Automobile Tires NFLATING tires quickly while on the road may be accomplished by the well known method of using one of the engine cylinders as a compressor. To take the place of the spark-plug on one cylinder—preferably the one in the r—make a connection for the air- hose as follows: “SNAP ON” CONNECTION HIGH TENSION WIRE TYPICAL SPARK PLUG GALV. IRON COUPLING — TO FIT SPARK PLUG oni ~ SSH YY " RUBBER HOSE~ABOUT WY ISFT. LONG WITH COUPLING ON END FOR TIRE VALVE. . “CYLINDER HEAD NIPPLE SAME SIZE AS SPARK PLUG. The completed connection from a cross-section view Use a nipple having the same thread as the spark-plug, and on this turn an ordinary pipe coupling. The spark-" plug-is turned into the upper end of the coupling. This provides a means of tapping the coupling for a side outlet, into which are fitted a small brass cock, a ball check-valve, and finally the hose connection. When it becomes necessary to pump a tire, connect the hose with the check- let the engine run.—P. P. AVERY. A Portable Pedestal for the Wheelwright OR the sake of economizing space, a wheelwright uses a portable wheel pedestal in his shop. The pedestal is a hollow truncated cone made of boards. An opening in the top HOOK FLOOR eye DETAIL This contrivance may be easily stowed out of the way when not in use allows an iron rod to project as an axle for wheels. The iron rod hooks to an eye in the floor, thereby anchor- Ing the pedestal.—_ JAMES M. KANE. A FEW OF THE MANY SIZES OF ists, Inspectors and Mechanics in all trades recognize the Starrett Tools as standards for accuracy, an assur- ance that comes through the knowledge that tools bearing the “Starrett” name are guaranteed. There are tools to meet every prac- tical requirement. Ask for our catalog No. 21 W. It also shows Starrett Hack Saws—the real economy saws. The L. S. Starrett Co. The World’s Greatest Toolmakers Manufacturers of Hack Saws Unexcelled ATHOL, MASS:, U. S. A. New York London Chicago Build Your Own Grandfather’s Clock with our help (~) in We furnish blue prints, fin- ishing material and instruc- tions. Buy the works, dial, weights and pendulum from usat surprisingly low prices. You make a fine proit building artistic clocks for your friends. Complete Works $5.00 Others with chimes at all prices Ask for attractive Free Offer CLOCK COMPANY s&s u Genuine Armstrong Stocks and Dies Gave You a Set in Your Kit? Some of the advanta of Genuine ARM- STRONG Stocks and Dies: : They can be adjusted to the variations in the size of fittings. Resultsare accomplished with less work and time. The Dies are interchangeable in the stocks and they can be shar pened without drawing the temper. Our catalog tells the rest of this interesting story; send for it to-day. THE ARMSTRONG MFG. CO. 1663 Ruff St. RRS. Philadelphia, Pa. Tee oe ower Prices Now BEST time now for getting your new engine—prices fA me ipments. More myers Pes Seaclina’ Eney to otart in any. kind { weather ~ caathe gasoline, oO » Same also burns OTTAWA. Kerosene and Gasoline Engines. For all izes 2, 3, 4, 6; 6,7, 8, 9, 10, Gate nd 32 HP. Stationary, Portal tnd a les 10-Year Guarantee. Get our catalog con and see big saving you can make now. Book Free a ee Write tocay fod 337 Knowlton Street - Bridgeport, Conn.

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“atoaaemas eos oe SS - — = SS SS es anesaeraarae . Popular Science .Mo h ~ cs Ee, RRR TTR RR TR TT TH) VU VY IOUIWYiGaws CO JODELL-PRA | Ro} OF 0 Fax 7 0) 0) OF 00) 0) FF YWUVWGwy Go AUIS Draftsman’s Protractor No. 50 N instrument fit to be in any draftsman’s set — accurate, strong andsimple. Thespring-tempered steel blade is 9 inches long. .The arc is four inches in diameter and graduated by degrees from 0° to 90°. A Vernier attachment reads to 5 minutes. The blade may be set by aturn of a binding screw. The binding screw affords an easy grip to the draftsman when shifting or lifting the protractor: The blades are joined to the arc so that all surfaces which touch the paper are flush. Either blade may be placed on the T square and will give all angles and their comple- ments from 0° to 90°. This protractor forms a perfect adjustable triangle. Finished in dull nickel, this paletinctot has the same skilful workmanship as every other tool or instrument of the Goodell-Pratt line. Draftsmen are as proud of Goodell-Pratt instruments as mechanics are of tools which bear our name. GOODELL- PRATT COMPANY GREENFIELD Soolsmiths MASSACHUSETTS 5 G OODELL-PRATT COMPANY