Popular Science Monthly 1921-02: Vol 98 Iss 2

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February, 1921; Vol. 98, No. 2 25 Cents a Copy; $3 a Year Popular Science Monthly Waldemar Kaempffert, Editor

— Published in New York City at 225 West Thirty-ninth Street

= Measuring the Emotions A way to test a man’s fitness for his task By P. J. Risdon English correspondent of the Popular Science Monthly system offers to the passage of an electric current varies according to the emotional condition of a subject. As mental disturbance increases, this resistance is reduced and permits of the passage of an increased current. Dr. A. D. Waller, the director of the physiological laboratory of the Uni- versity of London, applied the prin- ciple in an invention that actually measures the emotions and _ that should be of considerable value to ike resistance that the human

7G07 Lohviari. medical men in diagnosing mental and nervous diseases. The apparatus comprises a system of electric wiring connected with a galvanometer (an instrument that measures the effect of variations in an electric current by which it is influ- enced). The variations are recorded by means of a delicately balanced needle or pointer; a tiny reflector moves in sympathy with the needle. A light is concentrated on the reflector. As the reflector moves, a beam or bead of light reflected from it travels along a graduated scale. For convenience the scale may be placed in front of a mirror, so that the ope- rator and subject may both see the movement. In the electric circuit Lechanche cells and battery. <A pair of aluminum disks (called electrodes), wired up to the circuit, is attached to the hand of the subject, one being placed against the palm and the other on the back of the hand and held in position by rubber bands. Blotting-paper soaked in salt water is inserted between the disks and the hand to insure an unbroken circuit. A number of switches enable the operator to vary the resistances in is a pair of another small Aluminum electrodes are attached to the hand of the subject—one against the palm, the other on the back of the hand These are electrically con- nected with a reflecting galvanometer. Variations in the elec- tric current are recorded by means of a delicately balanced needle’ with which a tiny mirror moves in sympathy. The light is concentrated on the mirror. As it moves, the beam reflected travels along a graduated scale. Lunge at the subject with a pin with the evi- dent intention of pricking him, and the light moves rapidly to the very end of the scale.

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the circuit and the amount of current flowing. Now, the emotional response of dif- ferent persons varies greatly, and indeed the response of any one person varies considerably according to the time of day or, night and to his or her health. Consequently the apparatus has to be calibrated or set so that at the com- mencement of operations the bead -of light is at zero on the scale while the subject is perfectly quiet and free from excitement and dis- turbing influences. I cannot do better than relate here the tests to which Dr. Waller subjected me. Upon entering the laboratory, I noticed that the electrician’s hands were badly scarred, and ques- tioned him as to whether it was Dr. Waller’s doing. He made a motion of his head inthe affirmative. I was seated in a comfortable arm- chair. “‘Compose yourself and smoke,” said the doctor. Meanwhile the electrodes were fas- tened on my left hand and the instru- ment was calibrated until the spot of light was stationary at zero. Anticipation Is Worse than Reality Without the slightest warning, Dr. Waller then picked up a pin about four inches long and made a lunge at my right hand without touching it. The bead of. light moved right to the end of the scale and’ very slowly returned. Have you ever heard a Klaxon horn sounded in a laboratory? That was what next happened, with the same result. Then Dr. Waller really did prick my hand withthe pin; but the effect was less pronounced than "of which I had noconception. pose myself... As the bead returned, a pungent.odor, not infrequently encoun- tered in laboratories, had the effect of sending it up the scale again. ‘Dr.. Waller next warned me that he was going behind to do something to me Knowing what had already been done and what hadn’t, and thinking of red-hot pokers and of the electrician’s scarred hands, the spot of light traveled up that scale How the emotions write their own autograph, according to Dr. Waller’s method. These records were made in order to show the similarity of movement when hand and foot electrodes are used! in a way that made me blush for shame when I felt my ear tickled after half a minute’s suspense. The last of the experiments practised upon me consisted in first composing myself until the bead was steady xt zero. I was told to think of something (other than red-hot pokers) which had been a cause of worry and anxiety. That was easy enough—the only diffi- culty was to keep back a crowd of thoughts. I began to wonder what the editor would think of my adventure, and the bead of light traveled out of sight and remained there until Dr. Waller broke the spell. So, an unpleasant taste, a feeling of nausea —indeed, almost anything that temporarily disturbs equanimity—is recorded. As a result of a great number of ex- periments, Dr Waller concludes that, as a general rule, subject to some ex- Popular Science Monthly ceptions, anticipation produces a mora powerful effect upon naval and mili- tary officers and members of the liter- ary, artistic, and scientific professions, and that it is principaliy manual work- ers who respond to actual experiences more than to anticipation, which accords with inost preconceived ideag upon the subject. An important point about the in. strument is its calibration. When it is set to suit a certain person’s temperament, the diagram of resultg obtained cannot be directly compared with those obtained from another person for whom the instru- ment is_ differently calibrated. In other words, although zero on the scale (where the bead of light is at rest) is always in the same _ position, that position does not represent the same degree of equa- nimity for each person who is tested, A Curious Fact A curious fact in connection with the experiments is that they can be satisfactorily made only with elec- trodes or metal disks on the palms of the hands or the soles of the feet. Thus the electrodes may be -on either side of one palm, or one may be on the palm of one hand and the other on the palm of the other hand. The current from the Lechanche cells serves to equilibrate or balance the galvanometer reflector. The small electric cell sends a current of about one tenth of a volt through the circuit and the disturbance of the galvanometer by this additional cur- rent (which varies according to the re- sistance of the subject) causes the gal- vanometer reflector to move and the bead of reflected light to travel up and down the scale. when he pretended to do so. Such is the sense of duty to one’s editor, and so ready to suffer must a correspondent be, that I positively asked to be burned soasto record the effect. Twice Dr. Waller fumbled about with matches and sent up the bead of light. When he finally struck a match and actually applied it, the effect was much less pronounced than that produced by antici- pation of a burn. In fact, the bead moved so little that some one suggested a red-hot poker, whereupon the bead com- pletely disappeared as I thought of the electrician’s OOO _—., is that the extent of the sub- ject’s emotions is recorded whether he be conscious of any emotion and whether he show any external sign of it or not. Indeed, pent-up emo- tion effectively concealed and controlled is indicated in a more pronounced manner than if relieved by weeping; and this applies equally to other controlled emotions. Presum- ably swearing will now be con- sidered justifiable. One may hope that Dr. Waller will succeed in develop- ing his invention so that differ- : One of the strangest features ent emotions, such as anger, hands. I was then told to recom- Here Professor Waller is measuring the energy which is expended in riding a bicycle 22 sorrow, and fright, may be distinctly recorded. February Can Res’ EFC B Fre cau jmportar that an : the Gerr js being | To pum] over, to where th Accor under-w: lining. engineer Photo: lights. water of little pe conditio} Artif White but thos cannot § the ultre rays thi rays wil penetrat means ¢ Lens ra Instead vapor al to many it was il Its colol This | is used of the L The | castings and low thambe vapor ]: are in» carries | thirty-s camera: actuate are pre the car Reps made after have A ft er have | up, it matter the we Here j that is floode: France tog: ip ent coy

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wT aware wa wewao ! * Oo = CF eo a ou Pp _— . PS D= February, 1 921 Cameras and Dyivers to Restore French Coal-Mines France, the Germans flooded the coal-mines. Be- cause France was thus deprived of one of her most important coal-beds, it was provided in the Peace Treaty that an adequate amount of coal must be turned over by ihe Germans to France. In the meantime, every effort js being bent to restore the mines to their former condition. To pump out the water will be a labor of months. More- over, to facilitate it, the engineers must know exactly where the shafts and galleries were punctured. Accordingly, the French government decided to use an under-water camera for taking photographs of the shaft lining. The apparatus was supplied by the submarine engineers, Siebe, Gorman and Company. Photographing under water involves the use of powerful lights. But even the most powerful lights in the turbid water of a deep shaft reveals little; its beams have but little penetrating power even under the most favorable conditions. B, France they retreated from the Lens district in Artificial Sunlight for Under-Water Photography White sunlight is a composition of many colored rays; but those that are of greatest value in photography we cannot see at all. They are located at what is known as the ultra-violet end of the spectrum; they are the chemical rays that cause sunburn. These powerful ultra-violet rays will not pass through ordinary glass, but they will penetrate a glass made of pure quartz. Hence, the light by means of which photographs are made in the shafts of Lens radiate a light that is rich in ultra-violet rays. Instead of glass, quartz is used, which encloses a mercury- vapor are. The light of the mercury-vapor arc is familiar to many who work in factories and photographic galleries; it was invented and introduced by Peter Cooper Hewitt. lts color is a ghastly green, due to its lack of red. This lamp, then, supplied with quartz instead of glass, is used in the camera to photograph the inundated walls of the Lens mines. The camera itself consists of three main gun-metal castings bolted together one above another. The upper and lower castings are each formed with four water-tight chambers, and each of these chambers contains a mercury- vapor lamp of three thousand candlepower. The cameras are in four chambers in the middle casting, which also carries four additional lamps, making a light-totality of thirty-six thousand candlepower. The shutters of the cameras are electrically controlled. Special levers, actuated by rods, are provided to tilt the cameras. Repairs can be made by a_ diver after photographs have been made. After the holes have been stopped up, it is an easy matter to pump out the water. Here is the apparatus that is lowered into the flooded mines of Lens, France, to make pho- tographs of their pres- ent condition 23 Diver prepared fo go a Level of Flood water Cables a vapour Jamps fom : supply light. © Modern Publishing Company; drawing by G. H. Davis How the under-water camera and its lamps are lowered into position to photograph the shaft lin- ings of the Lens coal-mines so as to locate breaches made by the Germans in order to flood the mines

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Perfect Airplanes: Are the Result of Wind-Tunnel Tests HE airplane model is placed in a chamber in a long tube through which air is drawn in parallel currents. Instead of moving, the models in the air, the air itself is in motion, which amounts to the same thing, as it is the relative motion that sus- tains a body heavier than air in flight. Attached to the model is a deli- cate scale called an ‘aerodynamic balance’’; it measures the wind forces to which the model is sub- jected. Then one model is com- pared with another until one is obtained that offers the least re- sistance to the wind. Lessen the wind-resistance of any moving body, and yljou cut down the amount of fuel required to drive itata given speed. Only by such experimenting was the airplane developed to its present form from the early crude machines, Popular Science M onthly Teh Here is one of the smaller wind- tunnels at St. Cyr, France. It shows the chamber in which both the model and the aerodynamic balance are placed. It was with such smaller tunnels that the~ early improvements in aircraft After having been drawn into the uponthemodel’ssurfaces. Onecan tunnel, the air is expelled through an open cylindrical extension that diffuses it through these slats. The air in the tunnel is kept in uniform circulation to flow evenly obtain an idea of the huge dimen- sions of the St. Cyr tunnel by comparing the diameter of the tube with the man in the picture shown below 24 design started. Nieuport was the first to attain greater speed merely by giving an airplane a form that offered the least resistance to the air and he was guided chiefly by the results of wind-tunnel experiments Februar

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h i ‘y February, 1921 Outside the experimental chamber in which the aerodynamic balance and the model are placed sits a man at atable. His duty is to read the velocity of the air that is being drawn through the tunnel. When a hundred-mile-an-hour gale is sucked through the tunnel, it is practically impossible to open the door of the instrument-house in the center—so terrific is the suction The air is composed of countless eddies and swirls. A straight stream is wanted. Hence a grid like that shown is used to break up the eddies—a kind of sieve, in other words. The speed of the wind can be varied from a zephyr to a hurricane. The model is suspended in the chamber above the aero- dynamic balance and the air is drawn through the tube. Weights are added to the balance until the model becomes stable and steady. These weights measure the compensation of the forces of the air 25

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Popular Science Monthly Mid-Ocean to Become a Great White Way ? OME of our transcontinental express trains carry power- adopt the idea. It would indeed be an amazing spectacle to ful searchlights to entertain the passengers on the obser- vation-car platform. The powerful beam plays over the interesting parts of the passing scenery. Great fan-shaped waters. beams of light flickering over the Panama-Pacific Exposition grounds amused the crowds. Now it is proposed that the floating palaces of the sea see a great ship blazon herself on a still night of the sea, reckets breaking and shedding their scarlet rain on the dark Searchlights have reached a high point of efficiency, and the current to supply twelve large lights would be taken from An Electric Sawmill on Wheels HEREVER electric power available, be it in a shop or on a farm, the transportable electrically driven circular saw shown here will prove very valuable. A small electric motor, which may be attached to any plug, fur- nishes power for the circular saw, which is large enough to cut four-inch planks. The miniature sawmill rests on two large wheels and two supporting braces, and may be rolled to any spot where it is needed, even over rough pave- ment or sandy soil. It has been used successfully and economically in Germany, in spite of the fact that the cost of electric power in that coun- try is considerably higher than in the United States. In view of the fact that electric power is rapidly sup- planting steam power or the power obtained from gasoline engines in this country, and that in most localities farms can be supplied at comparatively small cost with electricity, this sawmill should be of interest to the American the power plant of the ship without overtaxing it. Stronger Propellers for the Airplane PILOT landing a DN4 airplane at high speed encountered muddy farmer. ground. The wheels sank into the mud This miniature sawmill on wheels can be rolled to any spot where needed; it is run by electricity 26 and the machine nosed over, the propeller making a number of turns in the mud. If this vital part of the airplane had been made of wood, it would have splin- tered into match-sticks. But it was made of “micarta,” Jaminations of cloth or paper coated in “‘bakelite”’ and sub- jected to heat and pressure. What is bakelite? Bakelite is a composition de- rived from the combustion of carbolic acid, creosol or phenol, and formaldehyde. Com- bined, these form a resin that, when subjected to combined heat and pressure for a suit- able time, carries the material into a hard state not affected by ordinary solvents or tem- peratures that would disinte- grate a gum or resin. Februar; ‘ Mr.B masks heads masks hangs IC. Pei the of man Wladys Poland women cheekbs the del people : puts pl them. Whe! geous s section remind The w: peries : baric ¢ see a he were i man, y followe him ab he mod them h Wha ping-pé paste, starts ' ping-p: them | enforce with with 1 casts t ally bu it is fi several it is as has the paints and lip trils, e the for of fact ally cu but ra in, T made

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February, 1921 oy _| Mr. Benda wearing one of his hideous masks and carrying the lifelike heads of two girls. He makes these masks in his leisure moments and hangs them on his studio walls azine today and you will see the name ‘‘Benda”’ in the corner of many of the illustrations. Mr. Wladyslaw T. Benda comes from Poland and he gives to the men and women of his pictures the high cheekbones, the slanting eyes, and the delicate chins peculiar to the people of Slavic origin. Yet he also puts plenty of American features in them. When you enter Mr. Benda’s gor- geous studio in the Gramercy Park section of New York, you are reminded of the “Arabian Nights.” The walls are decorated with dra- peries and pictures of glorious bar- baric color. And here and there you see a head so lifelike that, if Mr. Benda were not such a quiet, unassuming man, you would feel sure that he was a follower of Bluebeard. When you ask him about these almost human masks, he modestly tells you that he has made them himself! What materials does he use? ping-paper, cardboard, paste, and paint. He starts with strips of wrap- ping-paper and _ molds them bit by bit; he re- enforces the weak spots with cardboard. Thus with neither forms nor casts to aid him, he gradu- ally builds up a face. When it is finished, he gives it several coats of paint until it is as smooth as skin and has the true skin color. He paints in the eyebrows and lips, and cuts out nos- trils, eyes, and airholes in the forehead. Asa matter of fact, he does not actu- ally cut holes for the eyes, but rather punches them in. The rough edges thus made are painted black Paso up almost any fiction mag- Wrap- © Keystone View Company - x Making Masks Is the Hobby Bi. of Wladyslaw Benda By P.. Schwarzbach Working with wrapping-paper and cardboard, Mr. Benda gradually builds up wonderfully lifelike masks. He gives them several coats of paint until they are as smooth as skin and serve remarkably well as eyelashes. The inside of the mask is just a mass of short ends and glue; but when the mask is finished, this gets a coat of paint as well. We are all familiar with masks. On Thanksgiving Day nearly every small boy in the country dresses up in his mother’s or sister’s clothing and buys “What a sweet girl!’ you exclaim, looking at the then suddenly you notice the trousers and big feet that show below the edge He is shown working on a mask in the picture to the right picture to the left; of the kimono. They belong to Mr. Benda. 27 © Kevstone View Company This fearful creature has really a sweet and gentle heart within. For beneath its silken robe is the body of Mr. Benda. In spite of the large size of the mask, it is very light a mask that completely transforms him into another person. In drama and in dancing, masks such as those that Mr. Benda makes are a great help to the actors when they wish to portray various characters. Even in the days of ancient Greece and Rome, actors wore masks. In England, just after Shakespeare’s time, a form of drama known as the ‘‘masque” became very popular. And now we find it coming into existence in this coun- try. Several of Mr. Benda’s masks have been worn by Margaret Sev- ern, a well-known New York dancer. Some of his masks represent shy, demure maidens. He is shown below wearing one of this type, and, as you see, it completely transforms him. He put on the mask of a terrible deep-sea god, and looked so fierce that the spectators instinctively glanced toward the door. Mr. Benda has made several other strange masks, vividly painted in_ striking colors. Some of his women’s faces are haughty as well as shy. Some wear simple caps and others huge golden headdresses. One in par- ticular has two long (wrap- ping-paper) feathers of gold that curl gracefully and sway slightly when the mask is moved. There is also a perfect head of a Japanese girl and _ the head of an angry man. Mr. Benda spends much of his leisure at this strange form of sculpture; and he has two able assistants. One is a large black cat with the largest tail in the world; and the other is the smallest black kitten that ever climbed up the back of an upholstered chair.

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ENGINE ROOM 2-450 HP 1ER ENGINES THE ALULA” WING ON A “PELICAN” 4-TON MACHINE THE HANDLEY PAGE WING ON A LARGE COMMERGIAL AIR PLANE a & ee i Age es. “y ay Se Sie © Modern Publishing Company Two New Types of Airplane Wing In the new Handley-Page wing (shown in the lower part of the picture) is a series of hollow curved vanes that convert a single large wing into a number of small ones. By thus exposing a larger area to the air, the lifting power is enormously increased. In the Alula wing (shown at the top of the page) an important consideration is the eliminating of the “end losses’? due to the curvature of the ordinary wing-tip. This is overcome by apparatus contained in the Alula wing and operated by the navigator Popular Science Mont)! February, NE CE in| areasona of forced in a shor in the ca heavy log for the si the mach speed ret air. By new wing off and twenty-fi This r must be remarkak ments in made in form it | de Havil 230-horse remarkak Gree What enormou: wing. E develope lift tha: same ty attachme same ti conditior by a sil in front edge of | structed is estima be incre a given | weight wv not muc area. area will the expr power, reductio: The de of a seri narrow \ touch e would ay to flow power w not so. Virtually into a n there is ; to the a increasit In fut movable and clos

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] February, 1 921 Wings that Lift Heavier Loads English designers are making renewed and effective efforts to rival the birds in the air countered by aviators is to land ina reasonably short distance at greasonable speed, especially in the case of forced landings. Another is to rise ina short distance. It is obvious that in the case of large machines carrying heavy loads this difficulty is enhanced, for the simple reason that the heavier the machine the greater the power and speed requisite to maintain it in the air. By means of the Handley-Page new wing, the distance run in getting of and in landing is reduced by twenty-five per cent. This new wing of Handley-Page must be regarded as one of the most remarkable and important improve- ments in airplane design that has been made in years. In an elementary form it has already been tried on a de Haviland plane (D.H. 9) with a 230-horsepower Siddeley engine with remarkable results. Greater Wing-Lift Attained What is most noteworthy is the enormously increased lift of the new wing. Even the experimental airplane developed fifty-five per cent greater lift than. another of exactly the same type without the special wing attachment, which was tested at the same time under precisely similar conditions. This result was secured by a single additional vane fitted in front of the ordinary leading edge of each wing. With wings con- structed entirely to the new design, it is estimated that the lifting power will be increased to such an extent that for a given horsepower of engine the same weight will be lifted by a wing area of not much more than half the usual area. Alternatively the same wing area will lift nearly twice the load for the expenditure of the same horse- power, or the same load with a great reduction of horsepower. The design of the wing itself consists of a series of hollow curved vanes or harrow wings which overlap but do not touch each other. At first sight it would appear that by thus allowing air to flow through the vanes the lifting power would be reduced, but that is not so. The spaces between the vanes virtually convert a single large wing into a number of small ones, so that there is a far greater total area exposed to the air than in a single wing, thus increasing the lifting power. In future machines there will be five movable vanes arranged so as to open and close on each other somewhat in er E of the many difficulties en- By P. J. Risdon English correspondent of the Popular Science Monthly the. manner ‘of Venetian blinds or hinged louvers... The movement will, of course, bender the control of the navigator, who will control the extent of lift according to whether he is “getting off,’ flying, or landing. For instance, when he desires to attain full speed, he will close the vanes and practically convert them into a single wing. When he deSires to reduce speed and to land, he will open them. Owing to their small size as com- pared, load for load lifted, with ordin- ary wings, the new wings can be built much more stoutly, thus bringing the day of really efficient all-metal wings within sight. In the experimental machine, the additional small wings were fitted in front of the ordinary wings. The vanes extended from tip to tip of the wings, and were attached a few inches in front of the leading edge of each main plane by short bars. Even with this com- paratively crude attachment, the navi- gator was able to fly at a speed of fifteen miles an hour less than the minimum speed without it; and although the tail was well down and the nose up and “‘stalling’’ appeared imminent, actually no such thing occurred. Apart from this practical demonstra- tion, extensive laboratory experiments and tests have proved beyond question that the principle involved is a sound one on which to proceed. The Alula Wing The Blackburn Company of Eng- land have evolved an entirely different type of wing, which dispenses with movable flaps, known as “ailerons,” by means of which “banking” is effected. Here again greater lift for a given power was the main object, although there are other special fea- tures about both the wing and the air- plane to which it is being applied. In ordinary planes there is a con- siderable loss of power and lift, due to the curvature of the wing-tips. In the Alula wing these “‘end losses,’’ as they are termed, are eliminated. As the picture on the opposite page indicates, in plan the wing has a curved leading edge and a straight trailing edge. Viewed edgewise, the trailing edge is horizontally straight, while the leading edge is straight in the center portion, then it curves downward, and finally 29 curves slightly upward. Between the leading and trailing edges the plane winds or curves in a manner deter- mined by experiment. In the curved portions of the leading edge are a pair of hinged flaps under the control of the navigator. The effect of opening one of these flaps, or valves, is to “‘spill’’ the air, in much the same way that a jet of water directed into a jar is flung out again. What the Flaps Accomplish The opening of one flap increases the resistance of the wing to which it is fitted, and the disturbed air whirling past the plane reduces its lift, allowing it to sink, and causing a corresponding lift of the other wing, so that the air- plane automatically banks. Thus turning and banking can both be accomplished without the use of aile- rons or rudder, although it is not pro- posed to dispense with rudders. It was found necessary to raise the wings to a higher level, so that the planes are directly above the body of the machine. It is considered that the wing gives the best results on a mono- plane, and it will be applied more particularly to air “tramps.’’ Owing to the increased lift obtained, slower speeds are possible with heavy loads, and the design of the wing makes moderate speeds more economical. The Blackburn Company is accord- ingly proceeding with the construction of what they have named their four- ton Pelican aerial lorry, a machine capable of carrying a load of nine thousand pounds. The weight of the tramp itself, with fuel, will be fifteen thousand pounds. The span of wings will be 146 feet and the body will be 84 feet long and 14 feet diameter over fuselage. The two engines will be of 900 total horsepower, the cruising speed 72 miles an hour, the landing speed 55 miles an hour, and the rate of climb 410 feet a minute. Radical departures are made from orthodox design. The pilot’s cabin is situated in the nose of the fuselage. Behind it is the cargo space (seventeen hundred cubic feet) and behind that the engine-room. The pilot’s cabin will be hinged so as to swing right open, and the cargo—which will be scientifically packed in containers and carried upon trolleys on rails—will be run out bodily. It is estimated that the cost of freight between London and Paris will be only five cents a pound. If that figure is correct, there should be a wide expansion of such traffic.

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Photograph by Charles Curtis for the Popular Science Monthly “The inventor can’t do it all,” says Edison; “you’ve got to change people” Said M. . Edison, in an interview with Jaines H. Collins for the Popular Science Monthly: “Greater and greater production is the real road to general prosperity. The country that can lead in this matter will supply the world. “This should be the job of the United States. “The English, while fertile in invention, are extremely conservative. The Germans are more open-minded, but not Popular Science Monthly particularly inventive—they are most successful in applying the inventions of other people. The French are inventive, but their industrial genius does not run to quantity production. “We have gone farthest along these lines, but our con- servatism is also great. However, spurred on by the necessity for replacing expensive labor with automatic machinery, manufacturers will be increasing output, employment, skill, wages, and standards of life. February, the cheap One is V Interest Wages. requires t Hand pro man, wit $45,000 a in a speci the same ten dollar, labor cost depreciati forth. A presses in Dollars Corporati wages int company, would o Following workers the comn twelve or WI Wages heights. dollar-a- authoriti approxi If ev at war still be be incre comfort. without purchasi producer playing higher v purchasi ness ina at abno of worke idleness ferent fre High y ments in machine costs, br eventual ployees, Must h:

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February, 1921 enon on Super-Labor-Saving Machines ~ Employers and employees are equally concerned in this question about which Mr. Edison has some decided ideas are two competitors in keen rivalry to see who can work the cheaper. One is Wages, and the other Interest. Interest has certain advantages over Wages. An automobile factory, say, requires three hundred fenders a day. Hand production of one per hour per man, With a ten-hour day, would require thirty sheet-metal workers. At five dollars a day per man, the labor cost would be $150 daily, or $45,000 a year. By investing $50,000 ina special forging press, turning out the same number of fenders, two or three operators could be employed at ten dollars a day each, and the yearly labor cost cut to $20,000, allowing for depreciation, wages, power, and so forth. Already there are such great presses in automobile plants. Dollars can usually work cheaper than men, yet Wages has a curious advantage over Interest. For if the employees of the United States Steel Corporation put one tenth of their wages into the common stock of that company, within eight years they would own a controlling interest. Following the same plan, the railway workers could acquire a majority of the common stock in the railroads in twelve or fifteen years. What High Wages Cost Wages have been at record-breaking heights. There was talk of the ten- dollar-a-day workman. Not a few authorities believe that wages will stay approximately at these high levels. If everybody can be employed at War wages, and production costs still be kept moderate, the result will be increased purchasing power and comfort. But if higher wages continue without increased production, then purchasing power must be limited, for producer and consumer will simply be playing the game with counters having higher values marked upon them, but purchasing no more commodities. Idle- hess in a war-cost world is tragic to the ten-dollar-a-day workman, with food, rent, clothing, and all other necessities at abnormal levels. Many thousands of workers this winter can testify that idleness at ten dollars a day is dif- lerent from idleness at three dollars. High wages stimulate heavier invest- ments in labor-saving machinery. Such machinery increases production, lowers costs, broadens purchasing power, and eventually increases the wages of em- Ployees, who, while fewer in number, Must have greater skill. Wages and EPs every factory payroll there By James H. Collins living standards are highest in coun- tries with the largest investment in machinery, like the United States, and lowest in countries where machinery has not yet replaced human muscle. Do present conditions point to a new era of invention? Will it pay to invent and install very complicated and expensive machines—devices cost- ing a quarter million, a half million, and even a million dollars, and doing the work of hundreds, perhaps thou- sands, of men and women? Meeting the “Wizard” With these thoughts in mind, the writer went over into New Jersey to see an inventor whose work in the past forty years has probably done more to increase jobs, wages, the output of commodities, wealth, and comfort gen- erally, than that of any other individ- ual. Out of Edison’s brain have come not only complete industries like elec- tric lighting and power, but enormous expansion in human production, and enormously increased consumption of things as diversified as copper, coal, platinum, trolley transportation, build- ing materials, real-estate values, wire communication, music, the art of the actor, and business correspondence. At Edison’s library, they were dubi- ous about an interview. The ‘Old Man” had been working at a terrific pace lately, and was “‘jumpy.”’ Some- body had seen him disappear in the direction of the laboratory around noon. It might be necessary to wait an hour, maybe longer. And a highly condensed interview was urged. Within five minutes the “Old Man” turned up on his way to the library for data. His face looked drawn and his eyes tired. His clothes needed brush- ing and pressing; his old derby hat was dusty. While explanations were being made he had an absorbed far-away look; but at the bare suggestion of the idea his face lighted. “T’ve been working at that for fifty years,” he said. ‘‘But the trouble is, you can’t get people to doit! We have in this country an enormous capacity to invent super-machinery. But our desire to install the device is very, very weak, Human inertia is the problem, not invention. Something in man makes him resist change. He clings to his old equipment, and proc- esses, and habits, rather than scrap them for something ten times more productive. “Now, that probably sounds as $1 if I meant -the. wage-earners. who feel that new inventions will take their jobs away. But .I mean the manufacturer too. It is just as hard to change him.” As an illustration, he went back to his automatie ‘telegraph, which in the seventies scared British post-office officials with its prospect of one thou- sand words a minute. “In London I met an operator who asked me if I knew his brother in New York. We had worked together. ‘I'd like to have a word with you, but not here,’ he said. We went out to a beer saloon. ““*They’ve put up a job on you,’ he told me. ‘They don’t want your system to succeed, and are going to give you the old Bridgewater Canal line to Liverpool, which is never used now. If it has one leak it has fifty — I don’t think you can get a message over it at all.’ ‘Well, the only answer to that was to use a very strong current. Remem- ber, there were no dynamos then electricity was stil] in the battery stage. At Apps’ in the Strand- famous instrument-maker, you know —I found a big battery that Tyndall had used in his Royal Institution work. It cost a sovereign a cell and we needed one hundred cells. Five hun- dred dollars was a lot of money then, but my backer was game. We put that battery on the Bridgewater line. The Unpaid ‘Bill “We sent one thousand words a minute without a _ hitch—perforated paper—came out beautifully, without an error, clean and black—no, blue. The trial was repeated—perfect trans- mission. That battery jumped all the leaks and stood up for half a dozen tests, and had plenty of power left at the finish.” Edison chuckled over this defeat of red tape nearly half a century ago. “They adopted it eventually,’’ he added, “‘but from that day to this we have never received a penny from the British government—not a cent!”’ Edison maintains that we haven't begun to utilize our opportunities. “‘We had few automatic machines in the seventies and no very big ones,” he continued. “But there was one invention that embodied the whole principle of Jarge-scale automatic pro- duction—the Jacquard loom. It has been turning out beautiful fabric pat- terns for more than a century. In purely automatic mechanism a su- preme achievement, tremendously

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Popular Science Monthly February, Interest Wages. 4 requires t Hand pro man, wit require t At five labor cos $45,000 a in a speci the same three ope ten dollar labor cos depreciati forth. A presses in Dollars than advantage employee Corporati wages int company, would o Followin workers the comn heights. dollar-a- authoritie approxim If eve at war v still be k be incre: comfort. without purchasi producer playing t higher vz purchasi ness ina ten-dolla rent, clot at abnor of w orke idleness ferent fre particularly inventive—they are most successful in applying High V the inventions of other people. The French are inventive, ments 1n but their industrial genius does not run to quantity production. machine prosperity. The country that can lead in this matter will “We have gone farthest along these lines, but our con- costs. | supply the world. servatism is also great. However, spurred on by the necessity ny “This should be the job of the United States. for replacing expensive labor with automatic machinery, eventual “The English, while fertile in invention, are extremely manufacturers will be increasing output, employment, skill, ployees, conservative. The Germans are more open-minded, but not wages, and standards of life. must ha 30 Photograph by Charles Curtis for the Popular Science Monthly “The inventor can’t do it all,” says Edison; “you’ve got to change people” Said M.. Edison, in an interview with Jaines H. Collins for the Popular Science Monthly: “Greater and greater production is the real road to general

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February, 1921 Edison on Super-Labor-Saving Machines oe Employers and employees are equally concerned in this question about which Mr. Edison has some decided ideas are two competitors in keen rivalry to see who can work the cheaper. One is Wages, and the other Interest. Interest has certain advantages over Wages. An automobile factory, say, requires three hundred fenders a day. Hand production of one per hour per man, with a ten-hour day, would require thirty sheet-metal workers. At five dollars a day per man, the labor cost would be $150 daily, or $45,000 a year. By investing $50,000 ina special forging press, turning out the same number of fenders, two or three operators could be employed at ten dollars a day each, and the yearly labor cost cut to $20,000, allowing for depreciation, wages, power, and so forth. Already there are such great presses in automobile plants. Dollars can usually work cheaper than men, yet Wages has a curious advantage over Interest. For if the employees of the United States Steel Corporation put one tenth of their wages into the common stock of that company, within eight years they would own a controlling interest. Following the same plan, the railway workers could acquire a majority of the common stock in the railroads in twelve or fifteen years. What High Wages Cost Wages have been at record-breaking heights. There was talk of the ten- dollar-a-day workman. Not a few authorities believe that wages will stay approximately at these high levels. If everybody can be employed at war wages, and production costs still be kept moderate, the result will be increased purchasing power and comfort. But if higher wages continue without increased production, then purchasing power must be limited, for producer and consumer will simply be playing the game with counters having higher values marked upon them, but purchasing no more commodities. Idle- ness in a war-cost world is tragic to the ten-dollar-a-day workman, with food, rent, clothing, and all other necessities at abnormal levels. Many thousands of workers this winter can testify that idleness at ten dollars a day is dif- lerent from idleness at three dollars. High wages stimulate heavier invest- ments in labor-saving machinery. Such machinery increases production, lowers costs, broadens purchasing power, and eventually increases the wages of em- ployees, who, while fewer in number, Must have greater skill. Wages and [Jw every factory payroll there By James H. Collins living standards: are highest in coun- tries with the largest investment in machinery, like the:United States, and lowest in countries where machinery has not yet replaced human muscle. Do present conditions point to a new era of invention? Will it pay to invent and install very complicated and expensive machines—devices cost- ing a quarter million, a half million, and even a million dollars, and doing the work of hundreds, perhaps thou- sands, of men and women? Meeting the “Wizard” With these thoughts in mind, the writer went over into New Jersey to see an inventor whose work in the past forty years has probably done more to increase jobs, wages, the output of commodities, wealth, and comfort gen- erally, than that of any other individ- ual. Out of Edison’s brain have come not only complete industries like elec- tric lighting and power, but enormous expansion in human production, and enormously increased consumption of things as diversified as copper, coal, platinum, trolley transportation, build- ing materials, real-estate values, wire communication, music, the art of the actor, and business correspondence. At Edison’s library, they were dubi- ous about an interview. The “Old Man” had been working at a terrific pace lately, and was “‘jumpy.”’ Some- body had seen him disappear in the direction of the laboratory around noon. It might be necessary to wait an hour, maybe longer. And a highly condensed interview was urged. Within five minutes the “Old Man” turned up on his way to the library for data. His face looked drawn and his eyes tired. His clothes needed brush- ing and pressing; his old derby hat was dusty. While explanations were being made he had an absorbed far-away look; but at the bare suggestion of the idea his face lighted. “T’ve been working at that for fifty years,” he said. ‘‘But the trouble is, you can’t get people to doit! We have in this country an enormous capacity to invent super-machinery. But our desire to install the device is very, very weak. Human inertia is the problem, not invention. Something in man makes him resist change. He clings to his old equipment, and proc- esses, and habits, rather than scrap them for something ten times more productive. “Now, that probably sounds as 31 who inventions will take if I meant -the wage-earners feel that new their jobs away. manufacturer too. to change him.” As an illustration, he went back to his automatie ‘telegraph, which in the seventies scared British post-office officials with its prospect of one thou- sand words a minute. “In London I met an operator who asked me if I knew his brother in New York. We had worked together. ‘I’d like to have a word with you, but not here,’ he said. We went out to a beer saloon. ““*They’ve put up a job on you,’ he told me. ‘They don’t want your system to succeed, and are going to give you the old Bridgewater Canal line to Liverpool, which is never used now. If it has one leak it has fifty I don’t think you can get a message over it at all.’ “Well, the only answer to that was to use a very strong current. Remem- ber, there were no dynamos then electricity was stil] in the battery stage. At Apps’ in the Strand— famous instrument-maker, you know —I found a big battery that Tyndall had used in his Royal Institution work. It cost a sovereign a cell and we needed one hundred cells. Five hun- dred dollars was a lot of money then, but my backer was game. We put that battery on the Bridgewater line. The Unpaid ‘Bill “We sent one thousand words a minute without a _ hitch—perforated paper—came out beautifully, without an error, clean and black—no, blue. The trial was repeated—perfect trans- mission. That battery jumped all the leaks and stood up for half a dozen tests, and had plenty of power left at the finish.”’ Edison chuckled over this defeat of red tape nearly half a century ago. “They adopted it eventually,’ he added, “‘but from that day to this we have never received a penny from the British government—not a cent!”’ Edison maintains that we haven’t begun to utilize our opportunities. ‘‘We had few automatic machines in the seventies and no very big ones,” he continued. “But there was one invention that embodied the whole principle of Jarge-scale automatic pro- duction—the Jacquard loom. It has been turning out beautiful fabric pat- terns for more than a century. In purely automatic mechanism a _ su- preme achievement, tremendously But .[ mean the It is just as hard

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complex, Once a pattern is set on its cards, the Jacquard loom will turn out that pat- tern over and over. again, as long as you supply material, power, and up- yet absolutely practical. keep, to the end of time. But appli- cations of the Jacquard perforated card principle to production in other industries are so limited that you could probably count them on your fingers. Other basic ‘principles -are cams - on shafts, the pantograph as.applied to the eccentric lathe, the. drop press, rotary press,- special: drill “jig, and soon. All the inventor-need: know. ! ‘is what you want.to do, and how much, of it you have to be done, and he can, furnish automatic processes and big- scale mechanism. Sometimes the prob- lem will be worked out on mechanical lines, again electrical, again (-- the . grinding method -of- réemoying - metal, ; treble production, it might be econ- omy te replace even one hundred mechanics with a million-dollar ma- chine.” “Will present high wages hasten in- vestment and invention along thisline?” “IT hope so, but I am also skeptical. Wages are certainly high enough to- day, and skilled workers far from plentiful. .. That may play its part in appealing to the imagination of the manufacturer. But it also increases the opposition of; the ‘worker, who naturally fights harder to keep a hun- dred-dollar-a-week - job than. one at * twenty-five. dollars. a week. Auto- -matic machinery is just as profitable. and desirable when normal wages pre- vail. . Why, automatic -machinery in most industries would do away with ninety workers in every hundred. That Popular Science Monthly goods are cheapened, more of them sold, and more workers employed. Show me a work-force -of 10,000 men, and I’ll show -you 4000° or 5000 who ought to be retired. In 10,000 familie; there are probably 5000 persons why should not be working, but enjoying life instead. They can’t do it now. Ay. tomatic machinery will let them do it.” “What can workers do to prepare for such changes in industry?” “Many things. They might acquire technical knowledge and be ready to qualify for the better jobs made pos. sible by the automatic machinery, Even more to the point would be ac. quiring an open mind and broad view- point. Instead of a job and a trade, something learned once and made to last a lifetime, the worker should be prepared to see his work change ayain and again in a lifetime, chemical. New principles will be found, of course, but those already available would keep the inventor | and designer busy making new applications if inven- tion were the whole problem. But it isn’t. Human inertia is the problem—you can’t get people to see the point! A Government School “More machinery, bigger, more complex, more auto- matic—why, that is so im- porrant that I think the United States government ought to found an institu- tion— The ‘Government School of Automatic Ma- chine Designing.’’ The best brains available should be put to work. And there ought to be a_ fool-proof system of questionnaires for **You Can’t Get Men to See the Point,’’ says Edison T’S easy to invent, but hard to change ‘*Human inertia is the problem to-day—you can’t get men to see the point.’’ ‘“‘Will present high wages hasten invest- ment and invention?’’ asked Mr. Collins. ‘“T hope so, but I am skeptical. matic machinery in most industries would | do away with ninety workers in every hun- dred. To prepare themselves for such chang - es in industry, workers should acquire an open mind and broad viewpoint toward the modernization of industry. Instead of 99 men,’’ says Edison. weeding out the unimagina- hesearinm tive. “What line will invention take?’ was asked. ‘‘Will the new machinery be big, complex, costly? If we have factories installing million-dollar ma- chines, won’t that make the billion- dollar corporation obsolete?” “It depends on the industry. When automobiles are turned out by the thousand, special machinery is pos- sible. Cost of equipment is not im- portant if you have volume of output, because interest is cheaper than wages. Suppose an automatic machine costing $1,000,000 displaces 1000 mechanics. At $50-a-week wages per man, that saves $2,500,000 on the payroll. At 6 per cent, your million-dollar machine costs only $60,000 a year for interest, - and $200,000 depreciation on a life of five years. Lump interest, deprecia- tion, upkeep, and operation together at $500,000 a year, and you have saved the cost of the machine the first six months. When you remember that such a machine may also double or Auto- es But it is hardly fair to ex. pect that of employees when so many employers fail. | “It is a job for the sales- man as much as the inven- tor. Markets must be ex- panded so that they will take commodities in un- heard-of quantities, and justify big-scale production. Every increase in produc- tion, every new invention, like the automobile, increas- jobs and _ purchasing power. Greater and greater production, with abundant commodities for everybody, is the real road to general prosperity and a_ higher standard of life. acquiring a trade, theworker should America’s Job be . eady to wt his work change “The country that can again and again in a_ lifetime. lead in this matter will have the job of supplying the world. It should be Thisis James H. Collins, who interviewed Mr. Edison for Popular Science Monthly sounds cruel, doesn’t it? Labor fights the suggestion everywhere. But au- tomatic machinery will benefit labor, both in earning power and commodi- ties. If machinery supplants nine men out of every ten in a given industry, what happens first? Each man kept on the payroll] can earn higher wages, because more skill is required to ope- rate the more complex and costly machinery. Then production increases, 32 our job. The English are extremely conservative, and _ while they learned to talk of quantity production during the war, there has not really been any great change, although they are fertile in in- vention and research. The Germans are more open-minded, but not par- ticularly inventive—they are most successful in applying the inventions of other people. The French are in- ventive, but their industrial genius does not run to quantity production. We have gone farthest along these lines, but our conservatism is also great. If high wages continue, and force us to think harder, and improve our methods and increase output by new, large-scale devices and processes, that will be a good thing. Spurred on by the necessity for replacing ex- pensive labor with automatic machin- ery, manufacturers will be increasing the output of commodities, increasing employment, skill, wages, purchasing power and general standards of life.’’ February EO] Pp ing Ar Gre at The sty German man’s s suit, m cents t cents, a a hat fo Germ she was of cottc availab and ce nothing As a clothes hundret use. A nished » in forei ings, uy} linens, overall: dered walls, and eV for oil : Allo so-calle lose, W or stru In n is tran: is use rolls o hundre narrow six in tightly Twi thread metho in a fle is twis disk. on spc is mo twistil give t pliabil The trollin is too there ular. contir right Aft als ar and threa to w matic of mi Then

Page 15

1en, Vho lies who "ing Au- itz dare uire ’ to I0S- ery, ew- ide, > to be rain "an vill ing be are ile ity ere ge, in- uns ar- ost yns in- ius On. ese lso nd ve by eS, eX- in- ing ing ing February, 1921

A Paper Suit for One Dollar Making a virtue of one of the war’s necessities EOPLE are wearing paper cloth- P ing and even paper boots, in Argentina, Austria, Germany, Great Britain, Italy, and Turkey. The style originated in Austria and Germany, where one can buy a work- man’s suit for 58 cents or a regular suit, machine-tailored, at from 29 cents to $2.50, an overcoat for 51 cents, a pair of boots for a quarter, and a hat for a dime. Germany had to avoid nudity when she was cut off from overseas supplies of cotton, wool, and hemp. The only available raw materials were paper and cellulose fiker. So there was nothing for it but to wear paper. As a matter of fact, not only are clothes made from paper, but several hundred other commodities of daily use. Apartments can almost be fur- nished with the paper goods appearing in foreign markets now: towels, quilt- ings, upholstery goods, bed- and table- linens, curtains, sewing-threads, sacks, overalls, raincoats, collars, embroi- dered blouses, hairpins, hangings for walls, imitations of Persian carpets, and even horses’ harness and piping for oil and gas. All of these materials are made from so-called paper yarn—in reality cellu- lose, which makes up the framework or structure of all vegetation. In making paper yarn, the cellulose is transformed into paper, or old paper is used. The manufactured paper rolls often weigh as much as eight hundred pounds. They are cut into narrow strips from one eighth inch to six inches wide. These strips are tightly wound into disks. Twisting of the strips into round threads is next in order. The German method is this: The disk is contained in a flat holder and the stripped paper is twisted by two small rolls above the disk. Then the twisted yarn is wound on spools. Sometimes the paper yarn is moistened to make it pliable for twisting, and chemicals are added to give the finished product flexibility, pliability, and durability. The greatest care is exercised in con- trolling this twisting process. If there is too much tension, the yarn tears; if there is too little, the product is irreg- ular. Therefore the twist gearing is continually readjusted to give the right amount of twist. After twisting, other fibrous materi- als are woven in. Wastes from cotton and flax are introduced in paper thread. To increase its resistance and to waterproof it, the yarn is auto- matically passed through a warm bath of mixed glue, tannin, and water glass. Then it goes through a cold bath of

By Dr. I. Newton Kugelmass aluminum formate and is dried imme- diately. This treatment does for paper yarn what tanning does for the skins of animals. Paper clothes can be washed with hot but not with boiling water. They cannot stand machine laundering but must be hand cleaned or brushed. Acids ruin them; alkalis agree with them. They cannot go through a wringing process but must be allowed to dry out. They cannot be mangled. They will stand pressing, but it is safer

What Austrians Pay for Paper Clothes Cents Cufle <« -« «= =. 1 Collar - - - «+2 Workman’s suit - 59 Laundry-bag - 19 Child’s apron - 22 Shopping-bag - 14 Table-cover - - 42 Rain-hood « = 2 Hallrug - - - 33 Man’s suit - $1.40 Woman’s apron - 23 Window-curtains 46 - Shopcoat - - - 47 Overcoat - - - 50 Linoleum (sq. yd.) 33 warm.

33

not to iron the borders and folds. On the average, a piece of paper goods or a suit can be washed twenty times. One hundred million pounds of paper fabric is being manufactured annually in Germany. England is making paper yarn with American machinery. France makes a paper for clothing as well, but it is backed with cloth. Japan is using paper for straw hats, for filling silk, and for making thread. Most Japanese paper yarn is made from bamboo paper. Finally, Sweden and Denmark are just starting in the paper goods business. a © Kadel & Herbert — He looks fairly well dressed and comfortable in his paper suit, and his paper overcoat looks No doubt there is a large percentage of the same material in his brief-case and shoes

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Popular Science Monthly eee i OR Se: An Old Iron Raven that Comes from Japan ac is not the famous raven that perched itself on Edvar Allan Poe’s door and quoth “Ney er- more.” It is a less famous raven that is perched on the floor o/ a glass case in the Metropolian Museum of Art, New York city, and says nothing. There is a very good reason: the raven is of iron It is more than two hundred years old, and has traveled all the way to New York from its native country, Japan. A Japanese artist in iron, Myochin Shikibu Kino Munesuke, designed and made the raven, and then signed his name in Chinese characters under the To regulate the flow of the water, this tubular weir is raised or lowered by a movable member operated on shore This Big Pipe Regulates the Flow EIRS are placed in rivers, canals, and other natural or artificial water-courses to regulate the water- level in accordance with requirements. Emergencies like floods, freshets, and ice blockades call for an immediate change of water-level. In such cases most of the known types of weirs fail because they are too complicated to operate. A striking exception is presented by the tubular weir, a recent invention that has proved its merit under severe tests. That shown in the illus- tration is not the largest. The movable member of the weir is a tube of riveted steel or iron plates. Its length depends on the width of the river or canal, and its diameter on the height to which the water- level is to be raised. This watertight tube may be raised or lowered by a chain which engages sprockets in a band that: encircles the tube at one end. The tube is rolled up or down an in- clined bed in the masonry of the land support of the weir, either by hand or by motor. Both ends of the tube have gears that engage racks on both sides of the weir This iron raven is two hundred years old, and comes from Japan How Paris Is Making War on URING the world war, which disorganized all branches of pub- lie service in the belligerent countries, it became impossible, among numerous other things, to continue the warfare against the rats theretofore mercilessly conducted in all civilized countries of Europe. As is well known, the rat is extremely destruc- . some of the large seaport cities. The authorities recognized the absolute necessity of energetic measures, par- ticularly in the large centers of popu- lation, for the complete extermination : of the rat. The municipal council of Paris, urged and vigorously supported by the raven’s tail. Munesuke was a descendant of a well known ar- tist armorer who lived in the twelfth century, and he himself made many pieces of armor. Japanese = ar- tists who work in iron use no pol- ishing processes at all to improve the finish of their work; yet they will often cut their lines to a uniform depth and fill them with gold and silver. Courtesy of the Metropolitan Museum of Art the Rat health authorities, met, and after a thorough discussion of the problem declared war against the noxious rodents. An appeal to the public was issued which asked all citizens to assist in the war of extermination by provid- ing covers for all garbage receptacles and by catching and destroying as many ratsas possible. tive and is known to be the carrier of dan- gerous parasites and of even more danger- ous disease germs. In consequence, its enormous '_ increase became a_ public menace, requiring immediate attention. In France the sit- As an incentive to more vigorous effort in the destruction of rats, the city author- ities offered a_pre- mium of twenty-five centimes for each rat killed and delivered to the proper district officials. The dead animals collected at uation became crit- the different district ical when sporadic stations are sent to eases of a disease, a central station, strongly suspected ~ where they are cre- as being the bubonic Emptying a bagful of rats, pre- A twenty-five-centime bounty has mated. Rat-killing plague, were dis- paratory to carrying them to the sent Paris huskies into the sewers is now a _ popular covered in Paris and street to hunt for rats sport in Paris. Februa Th / N fi mecha trying on)) si benefit while monia, other correct minim The de Bel York | he ree gen int the la increas breath streng increa menta germ of ger Pro impro the de devote perfec point breatk The simple pocke fasten I c \ I s t

Page 17

me the Vas of Vno the ry, self 10Fr. ar- K in ol- ses ove Leir hey cut pth em and em OUS Vas ist rid- eles as le. » to ort . of or- yre- five ral red rict Pad ing ilar February, 1921 Would You Sing? Then you must first learn to breathe properly N inventive singing teacher has A finally given to the world a mechanism that will perform the most trying labor of singing lessons. Not only singers but public speakers will be penefitted by this new invention, while the number of cases of pneu- monia, influenza, consumption, and other diseases brought about by in- correct breathing will be reduced to a minimum. The inventor is Professor Bertrand de Bernyz, a voice specialist of New York city, and the mechanism, which he recently patented, he calls the oxy- gen indicator. The apparatus indicates the lack of oxygen in one’s system, increases by proper diaphragmatic breathing the amount of that oxygen, strengthens and develops the lungs, increases the stock of vitality and mental energy, dislodges many of the germ pockets, and lessens the danger of germ development. Professor de Bernyz realized that improper breathing interfered with the development of singers. He has devoted.the best part of his life to the perfection of a machine that would point out and then remedy faults in breathing. The machine in itself is simple and will fit into the pocket. It consists of a band fastened taut around the waistline and connecting with a dial. As one inhales deeply, the pressure of the abdomen against the band causes the dial hand to move across a series of figures. The figures indicated show just what amount of available space for oxygen one has in one’s system. When -there is a lack of oxygen space indicated on the dial, the pupil knows that he must undergo certain calisthenics to develop the diaphragm. By consulting the oxygen indicator he may see what progress is being made toward the improvement of his breathing system. “Every one should be capable of drawing in and maintaining two cubic inches of air for every pound he or she weighs,’ Dr. de Bernyz claims. ‘People do not breathe deep down. They try to reach high notes or to hold notes when there is no air in the stomach. The human body is made up of organs for breathing purposes that are never utilized. Most people sing from the throat and not from the diaphragm. If they would breathe properly, they would at least learn to use the physical apparatus that na- ture gave them.” in this picture Professor Bertrand de Bernyz is demonstrating his voice-culture apparatus. The center picture shows the instruments mea- suring how deep a breath the man is taking Other parts of the apparatus. Pro- fessor de Bernyz declares that few people breathe deeply enough; that we should inhale two cubic inches of air to every pound of our weight, fill- ing our stomachs as well as our lungs 35 i] —— == a Can you draw, rapidly, a continuous line between these parallel lines with- out touching them? If so, you are efficient A Psychological Test for Speed and Accuracy “TAKE a sharp pencil, place the | point between the two parallel lines.in the lower left-hand corner of the ‘‘maze’’ above, and draw, as rapidly as you can, a third line. This line must not touch either of the original lines, nor must you shift the position of the magazine or lift your pencil while you work. Keep a record of the time it takes you to complete a trip around this very complicated design. Such is the Thorndike ‘maze test’”’ used in many schools for determin- ing the drawing speed and accuracy of the pupils. Speed and accuracy are the chief factors in efficiency, which is all-important in this twen- tieth century. The children are given seventy- five seconds in which to work. At the end of that time the number of linear inches they have covered are computed and errors recorded. Some children are quick and careless, and others work slowly but accurately. Both types are given the proper in- structions. The test is given again an hour later. After five consecutive tests have been made, the records are tabulated by considering the aver- age results of the first test as one hundred per cent efficient. This is used as a basis for the other tests that follow. Results show that speed of move- ment increases steadily during the day. Accuracy, however, varies. It improves gradually till lunch- time. After lunch it declines. Is this not another indication of the fact that work done in the morning is apt to be more correct than after- noon work? .

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—_—_—— The lights that make possible a photograph of this desert hold- up scene at night get their power from the portable plant shown at the right At the right you see part of the portable power plant; two elec- tric cables carry the ‘‘juice’’ to a switch panel, whence it is dis- tributed as needed ‘ HE Hold-Up at Night in the Desert”’ flashes on the screen, and then you see your favorites lose all in a real, true desert. If you are not too much affected by the touching scene, you may wonder how the proper electrical effects are accomplished in that spot in obvious darkness. One large moving-picture company takes light to the desert by means of the portable power plant shown A Wild Airplane Ride through Omaha \ JHEN a wild-eyed broncho- buster dashed through the streets of a Western city in the early days, the inhabitants scurried to safety. Now comes a man dashing through Omaha in an airplane. For more than an hour he rushed down between buildings, and as a diversion did nose dives and tail spins at points only a few feet above the trolley-wires. His thrilling ride ended in the police court. Nebraska has no ordinance regu- lating aerial traffic, so the aviator had to be tried under a law known as the ‘‘ Runaway Team”’ law. Taking Electric Light into the Desert above. Two electric cables lead from the power plant to a switch several feet away. Here many wires branch out, carrying lights of varying power at the ends. Thus the “movie set” ean be located at considerable dis- tance from the power plant. A few spotlights are usually focused on the scene being taken, and several broadside lights are lined up on either side. Making Use of the Smoke of Walnut-Shells HICAGO packers boast that they use every part of the pig but the squeal. California walnut-growers burn the nut-shells for the charcoal produced and they also make use of the smoke. Thousands of tons of nut-shells are produced every day and their disposition became a knotty prob- lem. During the war, the shells were ground up and used as a hardener for explosives. With the advent of peace, this demand ceased and large quantities of the nut-shells accumulated. It cost too much to cart them away to the dump. ‘‘ Why not burn them to charcoal and sell the product to poultry-food dealers?’ some one suggested. This was a thought. The walnut-shells are _ first placed into a large bin from which they are fed into a rotating gas- heated kiln, where they are burned to charcoal. The. small black kernels produced sell for seventy dollars a ton. ' The smoke and gases from the burning shells pass into a long iron flue where they come into contact with water spray. A heavy mist or steam is formed. A suction fan is placed at the end of the flue, which sends the steam and light gases up the stack, where they discharge into the at- mosphere. The heavier particles, laden with creosote, denatured al- cohol, acetic acid,.and other com- pounds, precipitate into a recep- tacle at the base of the stack. The process is continuous and it requires very little attention. Two or three men are able to handle many tons of walnut-shells aday. They not only earn their salary, but add.a handsome yearly profit to the walnut-growers’ in- com”. In California, walnut-growers are getting charcoal from burned walnut- shells; the small black kernels sell for seventy dollars a ton 36 Popular Science Monthi,} Feb

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February, 1921 =z ‘2 METEOROLOGICAL STATION ~ PIGEON-LOFT AIR-CURR INDICATO PORTABLE LANDING“LIGHTS Landmarks for the Aviator no persion sscang arrangement of landing-fields would be an advantage to the itinerant airman who flies at night and who comes down in a strange region. For instance, if the pilot knows where the radio tower is placed with relation to the airdrome, he would know at once how to avoid a possible crash in approaching the field in thick weather. Vertical and portable searchlights illuminating the field are indispensable. Directing an airplane by wireless, the so-called ‘“‘radio localizers’’ on the modern landing-field should bear a 37 definite relation to the position of the airdrome. A plan suggested by the United States Air Service furnishes an ideal arrangement of these details. On one side of the airdrome is placed the meteorological and radio equip ment structures, which project upward and obstruct a clear approach to the field. On the other side of the air- drome are the localizers and the fog-dissipation mechanism built underground, and the markers. Here nothing pro- jects into the air to hinder low flying when looking for the landing-place.

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Popular Science Month; ce Child Welfare in Japan N Japanese schools the physical develop- ment of a child is given as much atten- tion as his mental development. On warm days he strips to the waist and his teacher watches him closely as he works. If he breathes improperly, he is corrected; if he is round-shouldered or flat-chested, he is given special exercises; if he is too thin for his height, a special diet is reeommended. In Japan, as in the United States, every child must go to school when he is six years old. He receives a six years’ course in morals, reading, arithmetic, gymnastics, and poetry. A New Garment for Surgeons "THE ghostly garments that surgeons wear when they operate are usually buttoned from neck to waist. The but- tons are very apt to fall off at the wrong time and even at best they are annoying when a surgeon is in a hurry to get in or out. A new type of operating garment has been invented recently by Mrs. T. H. Hin- man, of Atlanta, Georgia. There are no buttons or hooks and eyes on it—two strips of tape that tie at the back hold the entire garment in place. The two front halves of the waist have extensions that reach around to the back as shown in the illustration. Why not make mechanics’ clothes this way? Lift the Records with a Suction Cap CCIDENTS will happen to phono- + 4 graph records, no matter how care- fully one handles them. Oftentimes a record is badly injured while being removed from the machine. This happens through the hand slipping and one of the finger- nails digging into the soft surface of the record. The next time the record is played, there will be a click-click-click as the needle passes over this point. A little rubber cap, attached to the phonograph by a spring, enables one to remove a record with but slight danger of an accident. It is simply pressed to the surface of the record. It grips tightly and lifts the record into the hand with an easy movement. Wanted: A Substitute for Goldbeater’s Skin ARGE rigid airships, such as the R-34, which crossed and recrossed the At- lantic ocean in 1919, contain nearly a score of gas-bags filled with hydrogen. Each gasbag is lined with goldbeater’s skin, taken from a certain part of the intes- tines of a cow or ox. No other mem- brane answers so well in preventing gas leakage. The intestines of five hundred thousand cattle must be handled, scrubbed, cleaned, and applied to line the bags of so big a dirigible as the R-34. The cost is about $200,000. Here isa chance for a chemist to provide a cheaper substitute that is impermeable to hydrogen gas. 38 Canoeing in the Swimming-Poo! E have indoor swimming and tenni in winter, so why not indoor canoeing’ In most winter pools there is nothing to do but swim. You can’t lay yourself out for a sunburn, and if you try to play bal! you will surely slip on the wet pavement around the pool. The women don’t even have the pleasure of displaying their anti- wet suits. But if there are a few canoes in the pool, there will be plenty of sport. Canoe hurd- ling, for instance, can be practised wit entire safety. Even short races can be staged. The Chef’s Daily Manicure NE of the daily events in the life of a chef in any of the large New York hotels is his morning manicure. Before he touches food, his hands are carefully washed and his nails are cleaned, cut, and polished. The job is not given to a sweet girl mani- curist, but to one of the hotel physicians. He is always on hand during the day; should the chef accidentally cut himself, the doctor will bandage the wound, as he is there for that purpose. Chefs are precious these days; many of the French ones—unable to get their daily bottles of wine—have gone back to France, where the thought of prohibition can still be treated as a joke, though even in France there are heard ominous rumbles between the jokes passed at our expense. © Keystone View Company Februa Kee } ER te Bern that gr grows I it. On upon t brush t effectiv Four s} aft. car axl 0} the brushes car is ti Whe speed, | of wire The | just as be, an force. a HE inle was pu the en proble1 the loc paralle accom) was Cl towed reasser trip on

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February, 1921 Keeping the Tracks Clear -of Tropical Grass } ERE is a rotating wire brush that can tear up the weeds and grass. Bermuda grass is a tough tropical grass that grows along the railroads in Texas. It grows rapidly and it costs much to remove it. One of the engineers on the road hit upon the happy idea of attaching a wire brush to a number of :ars. It proved very effective. Four brushes are mounted upon a heavy haft. This shaft is driven from one of the car axles by a belt. The pulley mounted on the ear axle is large, so that the wire brushes reach a high speed even when the car is traveling at ordinary speed. When the brushes are revolving at high speed, centrifugal force causes the strands of wire rope to stiffen. The steel wires are so rigid that they are just as effective as solid steel rods would be, and the weeds are hit with terrific force. ive Carry Your Own Punch EW and mysterious is the glass bottle that is shaped like an hourglass but that contains something much more ener- getic than sand. The contents are in liquid form, and when dumped into a bowl containing sweetened water will form the concoction known as orange punch! Each half of the glass bottle contains a separate liquid, and the two are kept apart by. a cork placed between them. They do not come into contact with each other until they are dropped into the water simultane- ously. You might get one of these bottles and, if you are not partial to orange punch, fill the orange end of the glass with some other flavor. Two Sizes of Photographs with One Camera T is a simple device that enables the photographer to adapt his camera so that it will take two sizes of pictures. A stifl paper mask is fitted inside the camera between the lens and the film, while a smal! mask of thesame proportions and covering the same field is fitted over the finder. A cogged wheel having numbers near its rim is arranged on the outside of the camera’s side, so that it engages thé attach- ment of the film-turning device. These numbers are so spaced ‘that they indicate exactly the section of film that occupies the position exposed to the lens. In this way a film 314 inches wide, taking six pictures normally 515 inches long, can now include thirteen pictures 2!4 by 3!; inches. This is a convenience to be appreciated by one who likes to use his camera for large as well as small photographs. When he can take thirteen pictures instead of six, there is considerable economy to his advantage. This Ship Traveled to Its Destination in Instalments HE Canadian Runner was constructed inland for use on the seas. After she was put together at Port Arthur, Canada, the engineers were confronted with the problem of floating her to the ocean, since the locks along the Lachine canal, which parallels the St. Lawrence river, could not accommodate such a large boat. The boat was cut in two, tightly boarded up, and towed to the Atlantic ocean, where she was reassembled and made ready for her first trip on the briny deep. The reader will probably look upon this work with the thought that it involved a great outlay of money and labor. It really did necessitate considerable labor and ex- pense, but not nearly so much as the aver- age man would believe. The steel plates of the ship were merely unriveted in a floating drydock, and the ends of the two halves were carefully boarded up with two-inch planks. All of the cracks were filled up and water was allowed to enter the drydock. The two halves of the boat were then pulled out by attending tugs. The tugs also pulled the divided vessel through the canal. At the opposite end of the canal another floating drydock was brought into use and the two parts of the vessel were placed in it. When the water was pumped out of the dock, the planking that covered the ends was removed and the rivets placed. Ina short time the vessel was ready for service During the war Canada cut several ships in two in order that they might pass through the Lachine canal locks.

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Popular Science Month/:, a oe Basketball en Route E’VE had so many parades in the past few years that a parade must now be very unusual to attract attention. Thus when the boys’ clubs of San Francisco had a parade recently, they provided plenty of entertainment for the watchers. Two picked teams played basketball throughout the entire line of march. Their goals were carried by two large motor- trucks, which moved slowly at the sides of the street. Only the truck chassis was used in each case, and the baskets were mounted on wooden frames. The people on the sidewalks were well able to see the spirited game. The idea was novel, but history says rrothing of the disappointed ones who just missed seeing a goal won. A Tilting Reel for Wire F you have wire to wind or unreel, this tilting reel will solve your problem. Every one who has had occasion to handle wire knows how easy it gets tangled up into a hopeless mess. This reel is double-jointed throughout, and it can be placed in any position. When a heavy coil of wire is to be placed upon the reel, the reel is tilted over and labor is saved. The heavy counterweight at the lower end of the shaft on which the reel revolves helps the workman to throw the reel back into position. The pegs on the reel are adjustable for different sized coils. Whatever position is desired, the reel is so perfectly balanced that it will never be out of the operator’s control. Altogether it is ees a rare combination of - safety, convenience, and - economy. eascse SPY rei TUITTELIRT eee rowwe : ‘ Heit bs55.5% ie 8,7, KJ 6 va lokecteianets Shake pavatat Makatnt stat 53 xen od PAPER RIT Ng Oe CP ad a 2 ioe Mie 4 sie Rag The Self-Loading Hand-Truck ERY often the assistance of an extra man besides the operator is required to load a hand-truck. To avoid this, a truck has been invented that permits the loading of any reasonable weight by one man. The truck is placed upright close beside the article to be loaded. A long adjustable lever, which can be raised or lowered, lengthened or shortened, by means of teeth on its lower edge, extends from the truck’s only handle, and grasps the article to be loaded by means of a hook on its further end. One foot is placed on the lower part of the truck, the handle is pulled forward, and the truck is loaded. The Smallest Automobile OMPARED with the tiny car in which Miss Ula Sharon, a New York actress, travels up and down Broadway, the “flivver”’ is a monster. When she arrives at the theater she doesn’t park her ‘‘road- ster’ outside. Not at all; she drives it right into her dressing-room. It is so small that if Miss Sharon should get careless and gain a few pounds in weight she wouldn’t fit it. The car gets its power from a storage battery and will go ten miles before it needs recharging. With such a tiny car she can work her way up to the front ranks when a police- man holds up traffic and thus beat out the large, powerful automobiles. Wait on Yourself and Prosper OU want a loaf of bread, and you want it in a hurry. But when you enter the bakery, there are several people before you and you must wait impatient!) till your turn arrives, or even longer, if the autocrat behind the counter happens not to like your looks. That loaf of bread you want is within your reach. If only you could pick it up and pay the cashier! That is exactly what you can do in the new self-serving stores that are being intro duced all over the country. The merchandise is displayed on a series of shelves between which there are con- necting aisles. You walk through the aisles, gather in the goods you want, and then proceed to the cashier’s desk. It’s Small but Husky HE implement shown below is a jitney in every sense of the word. It costs only five cents an hour to operate, and it will do many different jobs—plow snow, pull logs, and haul wagons around the yard of a factory. It will also saw wood, run an electric generator to light a farm- house, or pull a cultivator through truck-garden. It is a gasoline jack-of-all- trades. ; It is controlled through the handles in much the same way that a motorcycle is controlled. It rolls along at a comfortable pace even when it is working hard. February, 1 (- b 7, me, F Typewrit: A TYPIS ii insteac back the ty of a line Edward A. A telese¢ connects W and operate operates tk pressing dc ing the cal spacing lin downward proceeds t pressure is the foot tr gradually carriage m¢ A Shiy INCE tl constru ber of expr duced. H Denmark. The goo and staun as a glanc Her desig ordinary beautiful ; The ens gave her stable wh concrete, V practically their theo this fond had a tast 5) Kadel

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February, 1921 Typewriting Helped by the Feet A TYPIST who prefers to use his foot fi instead of his hand in drawing back the typewriter carriage at the end of a line can use the invention of Edward A. Pfefferle, of Burley, Idaho. A telescopic rod on top of the desk connects with the typewriter carriage and operates without springs. The foot operates the device in both directions, pressing down with the toe when draw- ing the carriage toward the right and spacing lines, and pressing gradually downward with the heel as the writing proceeds to the end of a line. When pressure is placed upon the heel-end of the foot treadle, the rod telescopes and gradually extends as the typewriter carriage moves toward the left. A Ship Designed for Stability INCE the great concrete ship Faith was constructed several years ago, a num- ber of experimental vessels have been pro- duced. Here is one of the latest, made in Denmark. The good ship Bartels may be seaworthy and staunch, but she has very ugly lines, as a glance at the photograph will show. Her design would please a cubist, but an ordinary human being can see nothing beautiful about her. The engineers who designed the Bartels gave her this peculiar shape to make her stable while at sea. She is of reenforced concrete, which, her makers say, makes her practically unsinkable. Whether or not their theory is correct is not known, since this fond child of their brain has not as yet had a taste of the briny deep. 5) Kadel & Herbert It Locates the Trouble with the Telephone Wires VERY city has its network of wires, and it keeps many linemen busy the year around to maintain the service. Toll lines often have an earning power ranging from thirty to one hundred dollars an hour, which means a big loss for every minute the line is unnecessarily out of order. Linemen with ordinary talking sets are unable to make_ specific locations of trouble, and must be guided entirely by a test man at the wire chief’s office. Fur- thermore, when a lineman calls in for tests, he ties up another circuit, making a loss appear on two circuits—the one he is hunting trouble on and the one he is getting instructions over. This trouble-finder is designed to lead the lineman directly to his trouble. He does not have to cut any wires but simply follows a small “finder coil’’ in the set until he comes to the point of trouble. In this way sometimes hours of time are saved, a big item to telephone companies. Chairs HE factory worker is coming into her own at last. Rest-rooms and lunch-rooms have made her life easier; Comfortable Working and now Mr. William J. Koch, of La Crosse, Wisconsin, has invented for her an adjustable back-rest that will make her chair as as any. It is made of spiral springs, covered with canvas, that are firmly held by brackets attached to the back of the chair. The brackets can be adjusted to any width or height to suit the par- ticular girl who uses them. As she leans back the springs support her yet give her plenty of leeway. She is not apt to suffer from an aching back and the fatigue that usually accompanies it. comfortable Barking the Logs—How It’s Done tgp logs are ground for wood-pulp, the bark must be removed. In large paper-mills, where thousands of logs are handled daily, a very efficient process is used in the removal of the bark. The giant machine here pictured is used for that purpose. The logs are brought to it on mechanical conveyors. When the drum is full, an electric motor turns it, and the great friction between the logs tears the wet bark from the surface and they come out of the barking-drum clean and ready to be ground up. A single drum can handle several thou- sand cords of wood in one day. After the bark is removed, it slips out between the section. The barking-drum is of the continuous- feed type. i) NANA > OE Tihs 3 33.

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Popular Science Mo thly A Comb for Your Watch-Chain “QILVER threads among the gold” has a new meaning. The silver remains the same, but the gold is represented by a comb with a gold back that fits in a gold case. And the case hangs at the end of a watch-chain. The fit is a close one, and there is no chance of the comb’s slipping out of its case, thus revealing its iden- tity. Since it is about as long as your finger, it is no more conspicuous than a This Little Hen Broke the Record HE spectacular Babe Ruth has many name sakes in all walks of life. One of them is a white Leghorn hen! But she didn’t receive that name for any “home run” proclivities; on the contrary, she remained close to the chicken ‘“‘run”’ and laid eggs. In one year she laid three hundred and twenty-six eggs, completely breaking all pre vious records. That’s why she was named Babe Ruth. pencil dangling at the end of the chain. In the illustration above you see one of these combs in operation. Note how the case serves as a handle. The Automobile with a Soul HORSE will often neigh with joy A when it sees one of its kind; but an automobile is not credited with any such emotions. Yet here we have a ¢ar that started to roll down hill when its brakes were accidentally released; it was travel- ing at a terrific speed and it suddenly swung round, leaped the curb, hurdled a two-foot show-window wall, and came to an abrupt stop directly alongside of an- other automobile. Was it mere chance that led this runa- way car to a garage? Or did it have plain automobile sense and realize that garage meant home? The make of this remarkable automobile is not apparent; it is hardly to be guar- anteed that the rest of its tribe would dis- play the same amount of intelligence in similar emergencies. The Town Pump Rebuilt on Scientific Lines \ HERE there is no running water and where the old-style rural pump was required to draw up the water from the well, this new type of pump has been in- stalled. In a clear glass tube from which the air has been extracted, the water is forced into the vacuum by the pressure of the atmos- phere. As one turns the faucet and runs out some of the water from oe, the water from the well is sucked back into the tube until a certain limit is reached, on the same principle as that which operates a siphon. How much easier is this method of get- ting water instead of the old way of tiring one’s back by working the pump up and down, or of having to draw the water from the well with a rope and bucket, not to mention the greater cleanliness. Modern thought appears to be devoted to labor saving, either to enrich the manufacturer or to help the housewife. According to statistics com- piled by her owner, her feed for the year cost four dollars and the eggs she produced were worth sixteen. Thus she brought her owner a profit of twelve dollars. Old Airplane Parts in a Caravan iw you are one of the lucky mortals who can “‘go South” in the winter-time, why not get a light, comfortable caravan like the one below and live in it? The caravan is built on an axle and two wheels that were meant for an airplane. Many of these extra wheels and axles were left over when peace was declared, and such a cara- van as this offers one way of using them up. The body of the caravan is made of wood and canvas. Windows and ventilat- ing holes in the roof will prevent the in- terior from becoming stuffy. There are four struts, one at each corner, which are lowered to support the caravan after an automobile has towed it to its final resting place. © Kadel & Herbert February, A Japan L kK ha “a re would sm lampshade would not would pr ably less. never los! price unle home. Take, f hat; it co: top of a very acce you buy a care to, } amber or it color. A Japa might be contents Pu: O pu: riding the nove below. T that are and conn boat. The w this lever nishes be arms of t With s having t having t] dles are them to used bot desired. Kade

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thly oke Sabe ime- One horn elve ‘ome the cloge and hree oLRs, pre- why uth. com- feed eggs s she lars. ivan who why e the an is were these over cara- them le of tilat- le in- e are h are pr an sting: February, 1921 A Japanese Hat Used for a Lamp-Shade Buying a Quarter’s Worth of Electricity Ek have been assured that “a rose by any other name would smell as sweet,’ and a lampshade by any other name would not only work as well, but would probably cost consider- ably less. For lampshades have never lost the charm of high price unless they were made at home. Take, for example, a Japanese bamboo hat; it costs about fifty cents. Put it on top of a table-lamp and it will make a very acceptable shade. Yet where could you buy a lampshade for fify cents? If you care to, you might line it with pink or amber or any suitable shade of silk to give it color. A Japanese hat has still another use: it might be put over an open dish to keep the contents warm or free from dust. Pushing the Boat Along + iar push a boat from the back while riding in it is a feat accomplished ‘by the novel device shown in the picture below. The oarsman works a set of paddles that are attached to the stern of the boat and connected with a hand lever inside the boat. The working backward and forward of this lever manipulates the paddles and fur- nishes beneficial exercise for the back and arms of the oarsman. With such a device there is no danger of having the oars mislaid or stolen, or of having them lost in the water. The pad- dles are hung on ‘“‘hinges’”’ which permit them to ply the water easily, and may be used both at a time or individually, as desired. © Kadel & Herbert © Underwood & Underwood Abraham Lincoln Wore These Big Boots ONGS have been written about Lin- coln’s gunboats, but not about his own boots. Surely they are worthy of com- ment; they are quite the most uncom- fortable-looking boots imaginable. Leather was cheap in Lincoln’s time, and the shoemakers were very generous with it. The boots they made reached to the wearer’s knees. He had to wear them even on the hottest days. As for shape—there wasn’t much. A single strip of leather stretched from the toe to the center of the boot and then continued on up to the top. Lincoln’s boots were size fourteen, yet his feet measured eleven and a half inches. Thus two and a half inches of space was wasted, while his big toe had no place to go. In this day of scientifically made shoes it is difficult to understand the endurance of our forefathers that permitted them to smile in such discomfort. OU will find that this little attachment to an_ electric meter will allow you to purchase a quarter’s worth of current at a time. Quarter gas-meters have been in use for a number of years, put this is the first attempt to develop an electric meter to operate on this principle. The quarter is inserted in the slot and the knob turned in a left-hand direction. The meter will then allow twenty-five cents’ worth of current to pass. When this amount of current is used up, the lights go out and another coin must be inserted. This meter has been designed for use especially in summer resorts, where there is a floating population. Electric-light com- panies have always had great trouble col- lecting bills from such localities. To Jail by Airplane AERIAL policemen in San Francisco are + thus far the first to make use of the airplane to conduct a prisoner to jail, via the automobile patrol. The sky route offers the most direct passage between two places, and in this instance the prisoner was transferred from the Alexandra county jail across the bay of San Francisco to the locality where an automobile patrol was waiting to continue the journey through the city. Where it is necessary to save time, the airplane can be of service, as in this case. When the air becomes crowded with machines, the arrest of violators of the air-traffic laws will undoubtedly become common and aerial patrols will no longer excite comment. Kadel & Herbert a —

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An would know better than to roll his jewels into an elaborate cane- inspectors have expert smuggler top: long been suspicious of canes. ally an amateur smug- gler will try to swag- ger in with one There Is More than One Way to Smuggle Jewels Yet occasion- But it takes a clever man to succeed Popular Science M nthly February. A good cigar is some. : The ci times a smoke and roadst sometimes a jewel-box. tale akes Here -you see a cigar vides’ | which, when broken, i | a warm revealed a large dia. has b mond. The owner tried his life to smuggle it into the country, but the inspector got it firs The smuggler really has a difficult time thinking up harmless-looking hiding-places for his rubies and pearls. One man put them in his fountain-pen, another—a man wearing a peaked hat and a badge in his buttonhole—took A them out Tot speci tires The are oO! ered thus = ell , ‘ | A co Jewels and toothpaste—who This rubber heel may have beloy would associate the two? saved the wearer’s nerves a recti! “No one,”’ said the confident thousand shocks in the past, wind smuggler to himself. But he but it’s making up for it now. forw: was wrong; the inspector Imagine his feelings as the Thes ripped open the tube and inspector pries it loose and open squeezed out half a dozen takes out the pearls resting wher snugly within it thief smeary pearls spector looks it over very thoroughly. It has so many hidden corners This camera may be perfectly innocent, but the in-

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onth| ; some and el-box, L Cigar »roken, ic dia. er tried t into ut the t first February, 1921 Change the Body to Suit Your Taste No more family arguments over which style of car to buy The car is here a full-fledged roadster. This is the form it takes when Mr. McGuire rides to his office on a fair, warm morning. Mr. McGuire has been a coach-maker all his life To the right is shown the special compartment for spare tires beneath the rear seat. The backs of the front seats are on hinges and «an be low- ered to meet the rear ones, thus forming a bed A coupé for two is illustrated below. It is made by resur- recting the back and side windows and bringing them forward to the windshield. These windows cannot be opened from the outside, so when the door is locked, no thief can enter Photographs © American Remove the front window-panes of the sedan, fold up the top, and you have an open touring-car with a sort of victoria top. This changeable body is mounted on a “flivver”’ chassis ‘‘When a touring-car becomes a roadster’”’ is a suitable title for the picture at top center. The top is swung forward until its edge rests on the back of the front seat. The rear cushions automatically disappear below when this happens Below: What is it? A sedan of course. But the inventor, Mr. John J. McGuire of New York, has constructed it so that it can be transformed into practically any other type of car as the mood of the owner dictates

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Popular Science Monthly The End of the World Our sun may some day be a “new star” for the universe BLAZE of light flashes in the sky where perhaps no star was seen before, and a ‘‘new star’’ is heralded throughout the world. What does it mean? According to the gen- erally accepted opinion of astronomers, nothing else than the end of a distant solar system, a cataclysm that has, at least temporarily, terminated the ex- istence of a sun and its planets. Re- cent discovery has strongly confirmed this opinion. All astronomical eyes are directed toward a new star when it appears, and the remarkable changes in its light and color are observed. Photo- graphs are taken, and its spectrum, or color-band, is closely studied. Per- haps the star will have become so bright that it rivals all other stars and can be seen in full daylight. Gradually it begins to fade, usually changing from white to yellow, then to red, finally fading into a greenish nebula. This is the order usually followed in all the stars that are designated new, or temporary, stars. Long before the invention of tele- By Latimer J. Wilson scopes the occasional flash of a “‘nova’”’ attracted the eyes of people. Out of the darkness of night the brilliant new star seemed to flame, burning brightly for a few days and then sinking back into the depths of the unknown. What was a puzzle to the ancients, arousing only curiosity and superstition, has become a separate branch of scientific research, and to-day the problem of the new stars is seemingly within the reach of our understanding. Nothing in history is more amazing than the explanation that the most exact of sciences offers to account for the temporary stars. One of the most conspicuous ‘‘novae’’ of recent times was that which appeared suddenly in the constellation Perseus in 1901. It was a splendid object as seen with the naked eye. In June, 1918, another nova blazed out in the constellation Aquila. In each instance the star was actually seen to turn into a mass of luminous gas, a nebula; but the nova in Aquila has afforded the most aston- ishing confirmation of the theory o such stars. On the eighth of June. the night following the eclipse of the sun, this magnificent star was discovered by every one who looked skyward. For several nights it was the brightest star in the sky at that time, and in bright. ness second only to the brightest of all stars, Sirius. With the blue-white Vega and the pure white Altair, the nova of Aquila formed a gigantic celes- tial triangle in the summer sky, Photographs showed it on plates taken several nights before the date of its greatest brilliancy. In the interval it had increased in luminosity many thousand times. Prior to this it had registered on photographic plates as an exceedingly faint star in the region of the Milky Way. What is the meaning of these out- bursts in the distant realm of the uni- verse, and what import have they in the lives of men? To understand the meaning, one must understand the curious changes in their light as dis- closed by the spectroscope. The spectrum of a bright body is its light Seen from a distance the sun would appear utterly lost among the stars of the Milky Way. This pictures a section of the spangled stream of the galaxy. 46 The sun would be much closer to be thus seen than are any of the stars shown here Febr wary, This it sh mate rush spread | the bod solid, o1 form of color-ri vertical ment, s incande double shows i section: are pro rainbov the eco but th curious This w ered tk rounde

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thly iL: February, 1921 © This indicates the speed of the masses traveling from the sun if The expansion of the materials of the outburst, following the terrific and instantaneous rush of light and heat, would be at the rate of eight thousand it should imitate the new star in Aquila. spread out into a ribbon of color. If the body consists of a luminous heated solid, or a gas under great pressure, the form of this spectrum is a continuous color-ribbon, the color appearing in vertical bands and lines. A single ele- ment, such as sodium, when heated to incandescence, gives a single color, a double band of yellow. But hydrogen shows in the green, the blue, and the red sections of the spectrum. The electric are produces a continuous band full of rainbow colors. The sun also gives the complete rainbow-tinted ribbon, but this band of color is crossed by curious combinations of dark lines. This was a puzzle until it was discov- ered that a luminous body, when sur- rounded by gases of the same sub- OF EARTH / / EXPANSION 4 DAYS GHRS. / miles a second. than five days stances in a lesser degree of incan- descence, suffers a partial absorption of light, thus causing the formation of dark gaps, or lines across the continu- ous spectrum. The sun is surrounded by these cooler gases, and they stop some of the light sensations, thus pro- ducing dark spaces. These dark lines, by their position and grouping, show exactly what sub- stances are involved in the incan- descence of the sun and stars. When a bright body is surrounded by a blazing atmosphere of incandescent gas, bright instead of dark lines ap- pear, and these also have the same arrangement in the spectrum as have the dark lines of the same substances. In the region of sunspots are both 47 selec # fee lt If a cloud were shot from the sun at a speed of eight thousand miles a second, it would reach the earth in four hours, and would fill the whole of the solar system within less bright and dark lines. Some of the gases around or above the spots are at a higher state of incandescence than the gases within the sunspots. The displacement of these lines toward the violet or the red end of the spectrum indicates, among other things, motion in the line of sight. The principle is illustrated by a similar phenomenon of sound in which the sound-waves are crowded and shortened and rise in pitch as the object emitting them ap- proaches us. Thus a_ locomotive whistle rises to a shrill shriek as the train dashes in our direction, while it falls in pitch as the train recedes. So the light sensations are quickened with the approach of their source, or lengthened in proportion as_ their

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source recedes from our line of sight. This furnishes the key to interpret- ing the curious conduct of new stars. At first the color-ribbon is crossed by strong dark lines all shifted toward the violet or short-wave end of the spec- trum. This shows that the gases sur- rounding the star are violently in motion toward us. Then, as the nova flares brighter, strange bright lines ap- pear. But they are wide and diffused, their centers agreeing with their proper place in the spectrum. Measure the width of these lines, and you find that they are extended both toward the violet and toward the red end of the spectrum, indicating that the lumin- ous gases producing them are both approaching and receding——a strange anomaly! How can these blazing gases in the far distant star be both coming and going at the same time? The answer is one of the most ingeni- ous pieces of reasoning in the whole field of astronomical research. It assumes that the atmosphere of the new star is expanding in all directions around the core of the star in a bright shell of incandescent vapors. Hydrogen and helium are the principal gases involved. The motion in our line of sight on the near side of the incandescent shell shifts the bright lines toward the violet, while the mo- tion around this area is directed more Anybody Can Now 4 oot don’t have to be an expert pianist to make music rolls for player-pianos. Any one who under- stands time and rests can, by using the machine pictured, make his own rolls. There is a note scale, on which treble and bass notes are recorded. This scale extends the full width of the machine. Beneath it the music-roll paper is stretched. Perforations are punched by a pointer that trav- els back and forth across the note scale. When you have located the note you wish to register, you move the pointer to it. The time scale is at the left of the machine. After the operator has adjusted the pointer on the note scale, he moves the note scale to the proper place on the time seale. Then, by pressing lightly on a punch button, he makes a per- foration in the paper. If the note is to be held for and more away from us, causing a shifting of the lines toward the red. The rate shows that the expanding gases reach a velocity of nearly eight thousand miles a second. It is difficult to conceive of matter moving at such a speed. Then the question arose, might it not be possible to detect this expansion of the star in the increased size of its volume as seen through the telescope? Ordinarily there is no star, except the sun, that shows a measurable disk. The face of distant suns is indeed too remote to be seen except as a mere theoretical point of light. But this new star proved to be different from ordinary suns. Its ex- plosion was of such an enormous ex- tent that the star actually expanded until it reached a measurable diameter, and since the cataclysm first became visible it has continued to increase in size, though its light has waned, until to-day it shines only as a nebulous star that is just beyond the reach of un- aided visibility. The measured rate of expansion proved to correspond to the rate indicated by the shift of the spectral lines. Nova Aquila now appears as a starlike planetary nebula having a disk 3.8 seconds of are in diameter, appearing in telescopes to be as large as the largest of Jupiter’s moons as Make Music Rolls several beats, he continues tapping the button, moving the note scale forward a notch at a time. This is repeated until all the notes in that particular section of paper have been recorded. Then the paper is released and moved forward and work started on a new section. You repeat this action until the whole roll is perforated.

With a note scale on one side and a time scale on the other, any one can make piano-player music rolls with this new machine. 48

Popular Science Moni/ily seen with the same glass. But in actual size it dwarfs into insignifica: ce the vast space occupied by our <n and planets. The period usually re- quired in stars of this sort to retur? to their pre-nova degree of bright: ess ranges from eight to fifteen yerrs, This is exceedingly short when one ¢ jn- siders the magnitude of the outbur:t. Calculations show that the outburst of this star occurred nine hundred years ago. Light traveling 186,:)00 miles a second has been all that time reaching us from the region of ‘he cataclysm which regenerated a fzint sun into a new nebula. If imagination be permitted to run in the fantastic direction indicated by disasters of such gigantic scale as t iat witnessed in Nova Aquila, might we not imagine a similar catastrophe be- falling our sun in some remote future day? Perhaps the center of our solar system will suffer a similar convulsion. Something will let loose the pent-up energy of the star, rending asunder the bonds of gravity and releasing the compressed gases. In a moment the burst of incandescence would wither the earth and planets. In the distance across the ocean of space, astronomers on some other world would see a ‘nova’ in their sky, and it is not pleasant to think that we should be furnishing the spectacle. Present-Day Surgeons Must Be Good Carpenters ¥ JE have wondered at the skill of OY oes in grafting pieces of skin from a frog’s leg or from a human body upon the skinless injury caused by a burn or other accident. But the marvels of modern surgery do not end there. ‘‘Bone’’ grafting is an art that demands the skill of a specialist in the most remarkable kind of “‘carpentry.”’ Electrically driven circular saws in the hands of a bone carpenter can now be used to slot, splice, and alter a fractured part of one’s skeleton. Some- times a part of the broken bone is neatly shaped and slid down into a slot cut into a part of the fractured member. Screws of steel, silver, ivory, or screws made out of the patient’s own skeleton, are used to hold these jointed pieces firmly in place. One curious result of these ingenious attempts is that of repairing an injured jaw. A piece of bone removed from the edge of a broken hip-bone was found to serve splendidly when properly fitted into a man’s broken jaw. This man to-day literally chews his food with his hip-bone—an anomalous situ- ation indeed! Never before in the world’s history was there such an opportunity for bone carpentry as that offered by the war. The knowledge thus gained was not lost with the coming of peace February, : HE | Unite dreadnou now coas slated for control, a by the gu At Sant command Bob” Ev played part, giv blows to Colon wi pair of tv In the served as The I¢ ‘other v ment are and the boilers ar by two o which fa The wei will prob modern ¢ The ment W about tl ratus as John H in his trolled b ago. TI used by their att: ish moni barded t! the Belg: Hammo1 tending » equipme When the Jowc peake fc with her that the OS bu terials ai The peo had mill of good rial in and did The Lake W its sho dous q decayed substan: erly ce Nuisane gressive

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d 0t ne- _ red Ty, it’s ese ous red the und erly This ood itu- Lory yone War. not * other February, 1921 Sacrificing a Battleship to the Science of War The old “lowa’’ is first to be made the subject of wireless-control experiments and then shot to pieces HE most famous veteran in the United States Navy, the pre- dreadnought type battleship Jowa, now coast battleship Number 4, is slated for some experiments in wireless control, and then to be shot to pieces py the guns of the fleet. "At Santiago, under the command of ‘Fighting Bob” Evans, the Jowa played a conspicuous part, giving the mortal blows to the Cristobal Colon with her forward pair of twelve-inch guns. In the great war she served as a training-ship. The Jowa’s guns and valuable equip- ment are being removed and the. coal-burning boilers are being replaced by two oil-burning ones, which facilitate control. The weight thus saved will probably be used in modern deck armor. The wireless equip- ment will consist of about the same appa- ratus as that used by John Hays Hammond in his wirelessly con- trolled boat a few years ago. This system was used by the Germans in their attack on the Brit- ish monitors that bom- barded their positions on the Belgian coast. Mr. Hammond is_ superin- tending the instalment of the wireless equipment. When all changes have been made, the Jowa will steam down the Chesa- peake for some very thorough trials with her wireless control. It is desired that the ship shall be controlled alter- e nately from another ship, a shore sta- tion, and an airplane or seaplane. After the wireless tests have been completed, the Jowa will proceed to the battleship range and proving-grounds farther down the bay, where her crew i. © = - seury Bg hie ste ence ii: — al — al iy * —_ ‘Fighting Bob’”’ Evans’ famous old Jowa, which the Navy Department is preparing for very thorough experiments in wireless control will leave her. Control will then be taken over by a seaplane. The firing tests will be made as near to war condi- tions as possible. The Jowa will pro- ceed under her own power, when a squadron of destroyers will dash past her, enveloping her in a dense smoke- screen. The battleship force will arrive on the scene and will begin firing. With a blurred vision at great ranges, it will be almost impossible for the shells to hit their target except for the airplanes, which will spot the fire of the big guns. As each shell falls, its exact location in relation to the target will be radioed back to the pointers from one of the seaplanes. While wireless control of ships dates from 1896, it is still in its infancy and must be developed for safety’s sake. It is therefore reported that the battle- ship Ohio will be fitted out for this purpose later. Still another ship, the former German dread- nought Ostfriesland, may be used as a target for the big guns. This Ger- man ship has a most complete system of in- ternal protection and will therefore supply the needed example of deck protection. LIGHT PROTECTIVE HEAVY ‘ARMORED WIRELESS ROOM PROSPECTIVE oer 7 BELT ARMOR; v"4 ARMORED VERTICAL ~ ARMORED DECK ARMOR ENGINE COMPARTMENT ROOMS How the /Jowa is being refitted. The wireless equipment is about the same as that used by the Germans in their attack on the British monitors’ off Belgium How a Road Was Built from Salt OST road- building ma- terials are expensive. The people of Utah had millions of tons of good road mate- tial in their state, and did not know it. The Great Salt Lake washes upon Its shores tremen- dous quantities of decayed salt. This Sal med oe “ ae .*, gay oe eg ie eR, Ree ¥ “See f. ser her fat . ows i ee Se aes ® discovered its value as a road-building material. When properly treated it was found to have better wearing quali- ties than most. After the tests, it was at once decided to build a link of the Lincoln Highway with it. A small railroad was run into substance was form- etly considered a huisance until a pro- gressive contractor The steam-shovel is loading on railroad-cars decayed salt from the Great Salt Lake; the picture opposite shows how it was used purposes 49 Waste salt was discovered by chemical’ tests to possess ex- cellent qualities for road-making the heavy deposits and a steam shovel loaded the cars that carried the material.

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New Uses for the Photographer’s Tripod The tripod also comes in handy in the sick-room. If a tray is fitted with a nut corresponding to the tripod screw, a tray may be firmly fixed so that the dishes are safe It often happens that a photog- rapher is also an artist. In an emergency the artist-photog- rapher can use his tripod to advantage as an easel Steel Structures that Have No Rivets HEN a New York company en- gaged in electric welding opera- tions decided to erect a new building, its engineers suggested that the struc- tural parts of the steel framework be joined autogenously by welding in- stead of by bolts or rivets. They were confident that this method would save time and money. As there was no precedent, the municipal authorities, when asked for a building permit, refused to issue it unless tests were made that would satisfy the building officials that a welded structure would be as strong and safe in every respect as a riveted structure. Lap welds of various structural units were submitted to severe tests, the results of which were entirely sat- isfactory to the officials. They issued a permit for the erection of the steel framework, but insisted on a special test of the steel trusses of forty-feet span, which were to support the roof and the traveling crane of five-ton capacity. Two truss units of the fan type and with a span of forty feet were set up, supported at their ends only. They were placed parallel twenty feet apart and connected by steel cross-bars. The test load, consisting of gravel in bags, was piled in tiers on plank- ing placed on top of the steel struc- ture. The trusses were designed for a live load of forty pounds to each square foot, each truss supporting a panel of eight hundred square feet. They were tested with a load of one hundred and Popular Science Mo uthly If a tripod is firm, it will serve as a typewriter stand. A base is put on the typewriter into which a nut corresponding to the tripod screw is fixed Welding a Shaft with an Arc and a Steel Wire Lo new automatic arc welder will weld away for hours without attention. It will mend broken seams, plates, joints, and fractures. It is shown welding a steel wire toa shaft that was turned below size by mistake. The shaft is turned slowly and the wire welded to its surface. The wire is fed slowly by a small electric motor. It also passes through a simple straightener before it reaches the arc at the surface of the steel shaft. When the welding is done, the shaft will be turned over again to the correct size. Steel framework of a building can be welded together as safely as it can be fastened by bolts or rivets twenty pounds to the square foot, or a total load of forty-eight tons on the two trusses. Representatives of all building de- partments in Greater New York attended the test, which gave the most satisfactory results. The de- flections caused by the load were care- fully measured, and when the entire load was removed two days later, it was found that, with exception of one single point, all parts of the trusses had returned to their original position. 50 | February Savl LCi N be a harveste huge vel the Iron into wag side in t Accor Friedma load as shoveler The f four-wh can be rt miles ar its inve! yard m continu trucks smaller in rotat Friedm: save $' hand sh I The two lol veyors, compal second matica a side. truck | at the th PLA A new electric arc welder that does its work quietly and efficiently

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nithly | rve ase nto to an re er will thout eams, ‘e toa ze by slowly ace, small rough aches stee! e, the to the February, 1921 Saving $7000 a Day with a Snow-Removing Machine because it looks somewhat like a combination of giant farming harvester, war tank, and tractor, this huge vehicle picks up snow and ice at the front and unloads it at the rear into wagons or trucks running along- side in the same direction. According to its inventor, Samuel Friedman, of New York city, it can load aS much snow as eight hand shovelers in one twentieth the time. The foundation of the machine is a four-wheel-driven motor-truck that can be run at a speed of from two to ten miles an hour, and that, according to its inventor, can load 1300 eight-cubic- yard motor-trucks daily if operated continuously and that number of trucks are loaded one apiece or a smaller number loaded more than once in rotation. When this is done, Dr. Friedman claims that the machine will save $7000 daily as compared with hand shoveling. How the Snow Is Loaded The snow is picked up by means of two longitudinally inclined belt-con- veyors, which carry it up to a boxlike compartment at the rear, where a second crosswise slat-conveyor auto- matically discharges the snow through aside door into the body of a motor- truck running alongside the machine at the same speed and in the same N ‘ecatse it I the ‘“‘snow-tank,”’ ONE CROSS\ CONVEYOR They call it the ‘“‘snow-tank”’ for obvious reasons. By Joseph Brinker direction. Thus the entire snow pick-up and unloading is done mechan- ically. The longitudinal pick-up con- veyors run continuously while the tank is in motion, but the crosswise con- veyor is working only when the load is being discharged. The entire mechanism is operated by a 150-horsepower marine gasoline engine mounted at the rear of the chassis frame. Only one power plant is necessary, since special clutches are provided for vehicle propulsion, for the longitudinal conveyors and trans- verse conveyor. All three may be operated at once, or any one or com- bination as required. The longitudi- nally inclined conveyors at the front extend to within a few inches of the ground and are provided with heavy bladelike shovels on endless belts. These blades cut into the snow or ice and carry it up the belts as the apparatus moves forward. At the top or rear of the longitudinal conveyors, the snow is deposited into a hopper or boxlike receptacle, the floor of which consists of the transverse conveyor. The latter moves in either direction. As soon as one truck is loaded, it pulls away and an- other truck takes its place. In case the snow is not to be loaded into vehi- WISE It scoops up snow and ice and déposits cles but it is desired only to clean a path ten feet wide down the center of the street, one of the hopper side doors is left open and the transverse con- veyor run continuously and the snow is also discharged continuously to one side or the other. Doubling the Removal Capacity One especial advantage of the machine lies in the fact that it com- presses the’ snow in loading, rather than expands it, as is the case with hand shoveling. Due to the action of the longitudinal pick-up conveyor blades in raising the snow from the ground to the hopper, it is claimed that sixteen yards of snow on the ground are compressed to eight yards in the hopper. On the other hand, six cubie yards on the ground expand to eight yards with hand shoveling. Three men are required to operate the tank, the driver at the front in his own cab to steer and work the pro- pelling clutch, and two other men, who stand on a platform at the rear of the hopper, one to control the longitudinal pick-up conveyors and the other to manipulate the crosswise loading con- veyor. it in a steady flow into a motor-truck running alongside at the same rate of speed 61

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Long pincers reach out from the boat and bring them in ITHERTO — submarines have H been invented and constructed destruction. Their record in the great war, as every one knows, proved them an extremely sub- for purposes of dangerous weapon. But the marine shown below, an invention M. Raoul, a French abbé, is intended to be used for gathering sponges from the bottom of the ocean. It was built by a manufacturing company at Toulon, France, where it was thoroughly tested by sub- merging it to a depth of some three hundred feet in the har- bor. It stood the test per- fectly and returned to the surface without showing the slightest defect. The Racul-Rimbaud, as the craft is named, has a length of about fifteen feet, and in salt water displaces about 8°, tons. It carries two persons. It consists of a steel cylinder with a diameter of approximately five feet, and has a rounded cap at eachend. The sub- marine is entered through a manhole in the top, surmounted by a small tower. This opening can be hermetically closed by means of a cap, which may be operated either from the inside or from the outside, in case of an acci- dent to the submerging and emerg- ing mechanism. A simple turn of the handle of the closing mechanism is all that is necessary to lock or unlock the cover of the manhole. Construction of This Submarine In its interior the submarine craft contains two reservoirs capable of holding air at a pressure of about 230 pounds to the square inch, and three water bulkheads that serve for submerging and raising the craft. Two of these bulkheads hold 250 quarts each, and serve to overcome the greater part of the craft’s buoyancy. They are filled directly by the sea and are emptied by hand pumps. The third tank, which is located in the center, holds only about sixty quarts. It receives its water through a tube connecting it with the sea, and is emptied by the com- pressed air contained in the pressure tanks before mentioned. Under normal conditions the craft is sub- merged by filling this third tank with water and is raised to the sur- face by forcing the water out of it by compressed air. ‘or greatersecurity, a lead keel, weighing about fifteen By Jacques Boyer hundred pounds, is attached to the bottom of the craft, and may be re- leased from the interior in case of danger, to bring the craft quickly to of the surface. In front of the craft a sounding-lead weighing fifty pounds is ie CENTRAL ‘ WATER-TANK CONNING-*, COMPRESSED TOWER ~ “S/AIR Py. TRIMMING-TANKS PUMP ‘ DEVICE ELECTRIC i] “Mh LAMP iL\ Att | we ) LEAD ANCHOR 4 "he WHEEL SAFETY KEELWEIGHT rf KEEL WEIGHT RELEASE ARMS 7ARM Space is limited in this craft and this cross-section shows how compactly its interior equipment is arranged ANCHOR- OPERATING > YSPONG suspended, which may be lowered o raised by a hand windlass on the inside to produce slight vertical changes of position. The submarine is propelled by two oars of steel, which are connected with the interior by a ball joint similar to that of the torpedo-tubes. The ste rod of each oar has at its free end hinged wings which are gp arranged that they push against the water in a direction opposite that of the intended motion of the craft, and fold up when they are moved jp the direction of the boat's course. How Sponges Are Gathered E- GRIPPER In front of the keel is placed a broad wheel of moderate diameter, which, after the submergence of the craft, Gathering a harvest of sponges grown by nature on the bottom of : the sea, is the peaceful mission of this man-built monster 52 Popular Science Monthly This Submarine Gathers Sponges F: bru rests makes with resort lifting walter time | The spong conca a tele ated f side ¢ and e eral f the b craft like e steel fron serve: purpe ries | inca Jamps by e! from N b cal Betw the I dams They cept 1 Th dams the | down steel are ¢ super space are sl be ra the f dam. chain Tw A; at W years trap Colu reme!} effect the fi At chino youn; eve s recap spaw) snore Bure: ested

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ed or inside res of y two 1 with ilar to Stee] 3 free are so push ection ended d fold ed in boat’s ered placed derate the craft, February, 1921 rests on the bottom oi the sea and makes it possible to move the craft with the aid of the oars, without resorting to the tedious operation of lifting the hull by expelling part of the water in the ballast bulkheads every time a change of position is desired. The apparatus for gathering the sponges consists merely of a pair of concave cutting pincers at the end of a telescoping steel rod which is oper- ated from the in- side of the craft and extends sev- eral feet beyond the bow. The craft has a beak- like extension of plates in which serves a double purpose. It car- ries a group of incandescent lamps operated by electricity from a_ storage steel front, Maintaining N building the New York state barge canal much damming was necessary. Between Schenectady and Rome on the Erie branch there are eight huge dams of the so-called bridge type. They look like steel truss bridges ex- cept that there are no approaches. The first step in making one of these dams is to build a concrete sill across the bed of the river. On the down-stream side of these sills steel frames are built and they are connected with a bridgelike superstructure by hinges. In the spaces between the frames there are sliding steel gates which may be raised or lowered to control the flow of water through the dam. The gates are moved by chains wound and unwound by Two Years in the Life of a Salmon CHINOOK salmon was tagged by mistake on August 13, 1918, at Whidbey Island, Washington. Two years later it was caught in a shore trap in the Skeena river, British Columbia. You will undoubtedly remember that Prohibition went into effect between those dates. Could the fish have been influenced by that? At ‘the time of the tagging the chinook salmon must have been quite young, for it was mistaken for a sock- eye salmon. Thus at the time of its recapture it had -not- reached the spawning age. Then why was it near shore instead of out to sea? The Bureau of Fisheries is very much inter- ested in the wanderings of this fish. battery, and supports also a large basket into which the sponges gath- ered are deposited. The sponge- gatherer in the bow carefully inspects the bottom of the sea within the ra- dius of his lights. If he espies a sponge, he grasps it with the pincers Comparison with the figure of the man in the background gives a good idea of the size and proportions of the submarine craft at the end of the gathering-rod, tears or cuts it from its base, and deposits it in the basket. The interior of the craft is illumi- nated by electric lights supplied by the storage battery already mentioned, and the crew may communicate by telephone’ with the consort ship. Although the craft carries a crew of only two men, the supply of air quickly becomes ex- hausted. The installation of an air-purifying plant or of oxy- gen tanks is not feasible. The submarine must be raised from time to time and ventilated to prevent the men from suffocating. the Water-Level of a Great Canal electric winches in the bridge floor. During the navigation season the gates are down, but in the event of a flood they are raised to permit the escape of water. During the winter months the gates and the frames-——they rest on the sill but are not attached to it—are raised to a horizontal position, thus leaving an unobstructed channel through which ice and snow may flow. There are also dams of the fixed type which have movable sections for regu- lating the depth of the water. These sections are semicircular in shape; they are called sector gates. They are of steel and are counterbalanced by concrete blocks. Each gate rests on a wooden sill and is hand operated. The largest gates of this type in the world are located in the Champlain branch of the canal. There are six of them and they form a regulating notch in one end of alargedam. Each one has a steel faceplate that is twenty- six feet high and fifty feet long. They retain the water above the dam at a normal depth of four- teen feet. canal. and they rest on a concrete sill. This enormous movable dam is located on New York state barge Steel frames are hinged to the bridgelike superstructure, Abeve are shown the huge circular stee! plates that are used as movable sections in an adjustable dam 53

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A Pencil-Holder Made from a Piston F you want to make use of the discarded piston of an automobile engine, here is one way to do it. On the desk it serves Colored Lights for Window Display INDOW- DRESs- ERS who wish to introduce theatrical lighting effects can easily do so with the gelatine slide that fits across the as a paperweight, a pen- cil-holder, and a ciga- rette-holder, all in one. The small hole in the side of the piston, which was used to pin the piston-rod to the head, is just the right size to accommodate one’s cigarette, though there is no place for the ash. Not only does this expedient serve as a pencil-holder; it can also be made to do service as a flower-pot. “To what base uses we may return,” is probably the sentiment of the piston; but at least it is.a use. Men Who Repair Skeletons § Mice are two kinds of skeleton- menders—the bone surgeon and the skeleton-assembler. Art schools, medical colleges, and students of anatomy require an accurately constructed skeleton to aid in their work. All the bones must be properly assorted and carefully put together. They are strung on fine wires. The _ skeleton- assembler must also pick out of the hun- dreds of odd bones that are sent him the two hundred and more bones that belong to the particular individual being recon- structed. It is not an easy task, and the price of skeletons is justified by the amount of work required to construct them. Siam Adopts the Dry Dredger EMARKABLE progress in the con- struction of roads in Siam is evidenced by the photograph reproduced above. The big dry dredger is thoroughly modern and up to date. The endless chain of scoops digs up the loose ground or soil at railroad cuts. These scoops or buckets carry the material gathered in by them to the screens, where it is separated into sand and gravel which slide down in shoots by their own gravity and are deposited in separate piles. The motive power is supplied by a gasoline motor. The bucket’ chain can be extended to a distance of about one hundred and twenty feet. One of these large dredgers will remove and separate about two hundred and fifty cubic yards an hour. A depth of forty-five feet may be reached by the dredger and the material may be deposited to an equal height. The machine attracted a great deal of ‘attention when it was set up at its destination. The picture shows the appearance of the machine during the ceremonies of its dedication in the presence of the Siamese king and other dignitaries, who evidently attached much importance to the event. reflector holding an elec- trie bulb. The device consists of a metal frame that fits over the rim of the reflector. The gela- tine slide is supported in this frame by a netting of fine steel mesh. The color of the gelatine will not fade by exposure to the electric light. The colored screens can be automatically changed, throwing red, blue, violet, green, purple, and yellow light upon the display. Artificial moonlight as well as golden sunlight can be imitated, giving a richness to the setting of the windows. A Giant Mechanical Nutcracker RACKING walnuts is the job of this mechanical giant with its two ‘‘hands”’ having fourteen fingers on each. These metallic hands constitute two units, each of which can be used separately. The walnuts are dumped into a hopper at the top of the machine and are admitted to the pairs of open metallic fingers through metal channels. There are seven channels on each side. The open crackers are so arranged that the largest nuts can be held and yet the smallest will not drop- through. With a complete revolution of the device twenty- four nuts are cracked without crushing the meats. : © Keystone View Company ' Februar Type THE f shaft valuable for the carded s easy mat The t; tration ° used for arms or the spee to the 1 bearing casing, © The ligh A sp upright adapted T AIL bee tion of structic lies in iron. Each lock tc when t half is brace 1 lock w positiot the be clamps side. stakes place. Rail: up or with p

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' February, 1921 Typewriter Lamp Made from Speedometer Shaft "THE flexible covering which encloses the shaft of your speedometer becomes a valuable aid when you want to make a lamp for the typewriter. If there is not a dis- carded shaft-casing out ii, the garage, it is an easy matter to get one from the repairman. The typewriter lamp shown in the illus- tration was made from an old hall ‘‘tree’”’ used formerly as a hat- and coat-rack. Its arms or branches had been removed and the speedometer-shaft casing was soldered to the top of the tree. The electricity- bearing cable passes into the flexible metal casing, where it joins the top of the tree. The light can be easily adjusted. A speedometer shaft attached to any upright support mounted solidly can be adapted to making a table-lamp. Two-Piece Railroad Ties 2 Aas ties of special design have been developed to facilitate the erec- tion of small-gage railroads on large con- struction jobs. The secret of the method lies in the new tie, which is made of cast iron. ‘ Each tie is made in two parts and these lock together in the manner illustrated when the rails are Jaid. One end of each half is bent slightly upward so that it will brace the rails. The tiepieces also inter- lock when they are placed in the proper position. The rail is held securely against the bent ends of the ties by small iron clamps that are bolted in place on the out- side. Means are also provided to drive stakes into the ground to hold the rails in place. Rails laid in this manner may be taken up or changed in a very short time and with practically no expense but the labor. » ab pute % WOOD BLOCK {73° INSSRTED HERE, How We Look from Above HOTOGRAPHS taken from the air by aerial travelers show the ugly spots on the beautiful landscape made by man’s artificialities. Houses resemble confetti scattered on a green rug; fields look like a erazy-patch quilt. Roads and paths are puzzles for Sherlock Holmes to solve. Contrasted with these views, however, are many truly beautiful estates whose design ornaments the general landscape in a pleasing fashion. The new angle of view affords oppor- tunities for the future landscape architect. Cities of the future can be planned from the air; indeed, this method is already being used in planning the suburbs of some of our large cities. Coasting a Motor from Third Floor to Basement OME automobile factories assemble their motors on an upper floor, and then have them conveyed to the first floor or basement to be tested in the dyna- mometer. A quick way to get the motor downstairs is to “coast”? it down on a conveyor con- trolled by an air-operated device. The conveyor is started in motion by a single movement of the master air-valve. An automatic tripper causes the carriage to stop at a designated point, where the monorail on the carriage engages with the main rail on the ceiling of the dynamometer room. From this position the load can be shifted to any point in the room. How They Save Coal in England with a Flower-Pot FLOWER-POT will cut your coal-bill * in half! That seems rather strange, doesn’t it? Yet many fellow sufferers from the shortage of coal in England have put flower-pots in their stoves and grates and are using half as much coal as they used formerly. Before you build your fire, place an in- verted flower-pot in the center of the grate. If your stove is small, use a small pot; if large, a large one. Then lay your wood and coal around it. When your fire is going strong, you will find that your stove gives out just as much heat as it did when there was no flower-pot within. Should it happen that flower-pots are not much in evidence in your neighbor- hood, a brick will serve the same purpose. Pay-Envelopes Filled by Machine N using the new pay-roll machine, the cashier first lists all of the salary amounts. When thelast amount is listed, there is available, automatically added by the machine, not only the total amount of the pay-roll, but the exact number of each denomination of coin required for the pay- roll. After the schedule is prepared, the device is replaced by a coin-tray in which have been placed all coins, gold, silver, and copper. To the left of the coin-tray is a keyboard. As the amount for each envelope is called out, the operator presses the proper keys and pulls a lever. The machine automatically counts out the proper num- ber of each kind of coin and drops them into the envelope. At the same time the machine makes a printed record of the amount.

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Popular Science Monthly 7] © Kadel & Herbert Fooling the Rabbit-Hounds EVERAL dogs ~- chasing one small rabbit—that was too much for the humane societies of Oakland, California. They protested against the inhumanities of coursing, and the result was the me- chanical rabbit shown above. It is made of steel and wire, covered with a real rabbit’s skin. It is attached to the end of a long metal arm and is driven by a five-horsepower motor. The rabbit can make a speed of forty-five miles an hour, and completely fools the eager dogs that pursue it. Bees Eaten for Revenge EES are usually employed as manufac- turers of honey, which is everywhere considered a delicious food, but there are places where the bees themselves serve as a food. The negroes of Guiana, when stung by a bee, proceed to catch as many as they can and in revenge eat them. It would be interesting to know what hap- pens as an effect of the stings thus taken internally. In Ceylon the natives hold a torch under the bee swarm hanging to a tree, catch them as they drop, then carry them home, boil them, and eat them. The Queer-Looking Twins Are Baby Alligators HE man who took this photograph was a patient fellow. He waited several years before the event happened. He was on the job, however, and snapped this picture when the youngsters were a few hours old. Here they are, a couple of young alliga- tors just out of their shells. They are nota bit rough, like their parents. In fact, they are so gentle and playful that children could have a good time playing with them. True, like the snail, they cannot move very fast, but they get there. The one in the background has its mouth open. Probably its mama has already given it lessons in the wonderful art of fly-catching, since this is one of the delicacies in their diet. Mail Your Letter on a Trolley-Car a‘ ELLO, what is your great hurry?” says one native of Hamburg, Ger- many, to another. “IT want to catch a mail-box,” replies the other, dashing off down the street at great speed. Mail-boxes are in the habit of standing still in the United States, and the above conversation would sound strange to us, In Hamburg and other European towns, however, the postal authorities have found it advisable to place mail-boxes on the back of the street-cars. Food that Arabs Eat RABS catch locusts, roast them, pul- - verize them, and eat them as a pudding. To prepare them for food, they dig a deep hole in the sand and build a fire in it. On top of this fire they throw bags of live locusts, cover them with sand, and build another fire on top. When they have roasted thus for a suitable time, the Arabs take out the locusts and grind them into a powder, which they mix with water and eat as a pudding. Locusts are pests in border regions of the Sahara, but when other food is scarce, they are welcome. A Daffodil Will Make a Novel Candlestick TOW that electricity has been 4 installed in most city houses and has done away with lighting inconveniences, people are clam- oring for candles! Gloomy candle- light when given off by artistic candles is preferred to the efficient glow of electric light. Here you see an artistic candle in an even more artistic holder. Should you fail to recognize it, let us announce that it is supposed to look like a daffodil. The flower itself holds the candle, and three of the leaves make the stand. The entire flower is made of | metal and is painted yellow and green. Were it not forthe sharp unnatural bends in the leaves you might mistake the candlestick for the real thing. This is adaptable to any flower with a deep corolla. = An Electric Decorative Table Fountain ONCEALED in the base of this fountain a small electric motor keeps the water in circu- lation. No water connection is needed, and the fountain, with the charm it lends to its surroundings, can be added to any dining-table, sick-room, or living-room by merely inserting the plug in the electric-light socket. The fountain is made of lac- quered metal, cement, stone, or marble. It costs but a fraction of a cent an hour to operate, and there is absolutely no danger of its overflowing, since it contains only a few cupfuls of water. If this small fountain becomes popular, larger ones will un- doubtedly be made. Perhaps they will take the place of the tall flower-pot stands that, went ] out of style a few years ago. 56 N Ds cent sixte Tl old ; well of gi drop ture pris und the | N the and pres wat

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7 Car ry?” Ger- plies et at cling bove 0 US, wns, ound back - pul- as a dig a in it. f live build have Arabs ntoa id eat order other come. se of ectric circu- on is th the lings, table, 1 by n the f lac- le, or ion of , and rer of itains comes | un- rhaps f the went February, 1921 A Huge Japanese Fan Blows Away the Chaff Micke than sixty per cent of the popu- lation of Japan is engaged in the pursuit of agriculture, but there is room for improvement in their methods. One of these is shown in the illustration. It consists of an old bellows fan which is worked to blow the chaff from the wheat. More than one million acres in Japan are devoted to wheat-growing. Strangely enough, even with the unscientific imple- ments that are used, the soil of Japan ranks higher in general production than that of Italy. What could be accom- plished by the use of modern time-saving devices can be imagined. The law requires that all suitable land not used for other purposes must be cul- tivated, and if any remains idle a certain time the state makes plain that its owner is violating the law. Antwerp’s Old Torture Pump N the Steen, an old castle in Antwerp, said to have been built in the ninth century, is a pump that dates from the sixteenth century. The water comes from a Roman well as old as the castle itself. It was from this well that water was drawn for the purpose of giving the ‘‘water cure,” the “drop by drop,’”’ and other fiendish methods of tor- ture employed upon the’ unfortunate prisoners confined in the dark dungeons under the building in the dreadful days of the dark ages. Note the remarkable leverage by which the piston-rod of the pump is worked up and down. As a vacuum is created the pressure of the atmosphere forces the water upward. | tea | Bill li ee a SO | lh | The Concrete Garbage Furnace ISPOSING of waste from the table and the kitchen is sometimes a problem that must be met by the individual instead of by the community. When one lives out- side the city limits and has not the benefit of garbage collection, he must get rid of waste products as best he can and with as little delay as possible. The use of an outside concrete furnace, inexpensive in construction, solves this problem satisfactorily. The quick fire made possible by the specially constructed flue burns the waste with the least effect of smoldering. The fumes escape rapidly and are blown away, instead of remaining in the air, as they do when garbage is burned in a heap in the open, Starting an Exciting Hoople Race on the Ice at Lake Placid WENTY years ago every city child had a hoople, and chased it for blocks and blocks with astick. But to-day you see very few; the danger of running into automobiles is undoubtedly the reason. The children of yesterday, however, are grown up today, and many of them still cling to their hooples. But instead of chasing them through the streets, they chase them across the ice on skates. nice ats A hoople race is very exciting. The con- testants are lined up at the starting posi- tion, and there is just enough space between them to make room for a hoople. If the hooples don’t follow the straight and narrow path, they will collide and put their owners out of the race, sometimes spoiling the chances of several contestants. © Edwin Levick

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Fish-Nets for Active Babies F all people were as ambitious and persistent when they grow up as they were when they were babies, this would be a great world. Long before a baby’s feet are strong enough to hold him, he tries to stand. Then, when he has finally learned how to stand and the newness of it wears off, he tries to climb. If he does manage to reach the top of his crib, he will undoubtedly fall out and hurt himself. In an institution where many babies are brought up, this matter of climbing and falling assumes large proportions. Thus in one English babies’ home all the cribs have fish-net covers. When the babies are awake the covers are fastened down. The Stroke-Counter for Golfers O you play golf? Then you know how difficult it is to remember the exact number of strokes in which you made each of the eighteen holes of an exciting match. The counter in the accompanying il- lustration enables the golfer who carries it to keep track of his record, hole by hole, with the least possible inconvenience. The counter resembles a watch with a dial on each flat side. Each large dial has nine small dials, resembling the second-dial of a watch, but divided into twenty divisions, one for each stroke. In making the record, the first of the small dials, directly under the stem, indicates the number of strokes for making the first hole. At each pressure of the knob of the stem the hand of the dial moves one degree. It is assumed that not more than twenty strokes are required to make any hole. Trapping Vagrant Cats RRAT-TRAPS are common, but imagine a cat-trap! Such a device, for ensnaring vagrant cats, has been designed and constructed by Ned Dearborn, of the United States Bio- logical Survey. The trap is so pivoted as to pull the prop under the edge of the box when the latter is raised. As the cat reaches for the bait, the treadle is tipped that springs the trap, the box falls, and a rod, coming in contact with the cat’s back, releases an ounce of carbon bisulphid, which instantly and pain- lessly asphyxiates the animal. The authorities proclaim the object of the trap “for catching vagrant cats and disposing of them humanely.” Rowing Twelve Miles an Hour with Your Feet UR legs are stronger than our arms. Why not use them instead of our arms whenever possible? That is the idea that occurred to the man who designed and constructed the boat shown below. He drives it with a pedal arrangement similar to that on a bicycle. A regular two-blade propeller is used, which gives a speed of from ten to twelve miles an hour if a ‘‘husky” is at the pedals. Driving a boat in this way is very good exercise for everybody, and persons who like open-air sports will enjoy this one. The boat can also be driven in the usual way with a paddle or oars. Popular Science Monthly Use Old Automobile Cushions USHIONS that helped make your car an easy-riding one in its da) should not be junked when the car is given up as lost by automobile doctors Keep them; if necessary, re-cover them then place them in front of an ope fireplace. If you wish to toast marshmallows o: roast popcorn, you will have an excel lent seat. By resting your elbows on your knees you keep your arms from growing tired while the roasting or toasting goes on. Any housewife could think of a dozen uses for old cushions, and for once the man of the house will agree that ‘‘that old junk” makes a welcome addition to a fireside seat in his smoking-room. Planes that Went to Alaska USINESS men of the future will prob- ably own summer cottages in Alaska. The families will enjoy the delights of an arctic summer, and the husbands will take a “fly” up there to spend the week-end with them, making the trip from New York in the Alaska Flying Express! This is, of course, but a speculation of the future. That it is not an impractical undertaking has been demonstrated by the recent flight from New York city to Nome, Alaska, conducted by the United States Air Service in its memorable trail-blazing expedition. The illustration shows the rudder of one of the three airplanes that made the flight. On it is painted the name of each stop included in the round trip and the pilot’s and mechanic’s names. Feb a ae ee bel pla nic all: a by tra the bo th thi co re ha m: 8Q) fo. du lol hi le’ sti se m sO hi Su Sij

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February, 1921

A Piano-Practice Keyboard ( N this new keyboard the keys have depressions in them. The inventor believes that these depressions will help piano students to develop better tech- nique with less practice than is gener- ally necessary to produce a good player. The depression in the center of the key trains the finger to strike the center of the key while playing. By the continuous use of this key- board, the student will train himself so thoroughly that his fingers will strike the center of the keys on a piano without conscious effort. This is one of the requisites of successful playing and it has always been very difficult to master.

‘‘Hustling’”’ the Underground ONDON’S ‘“Underground”’ is a scene of rushing crowds and swift trains. The scramble to get aboard at the station plat- forms necessitates having a man whose duty it is to prevent a train from stopping longer than its fixed time at any station. A special box is built for him; and, with his watch in one hand and the handle of a lever in the other, he keeps tab on the train stops. Ifa train remains longer than thirty seconds, he pulls the lever and this sounds a siren that warns the train crew that they must be off. In the New York subway a gong is sounded for the same purpose. With the hurry and crowding always to be found in subways, the gong is the less nerve-racking signal.

How to Prevent Gas Explosions F city houses were equipped with an automatic device to cut off the gas as soon as fire reached the spot, probably many big fires would be prevented. Even a small fire that reaches the system of gas- pipes in a building can gain momentum by the burst of flame that follows. There is a device arranged on each floor which automatically closes the flow of gas. Soft metal lugs on a connecting lug under the ceiling of each floor melt at 150° F. This disconnects the rod, releasing the handle cock in the cellar, which closes the gas- immediately. 3 It would seem a wise law to make such a device compulsory in all large buildings.

© Keystone View Company Spreading the Whipped Cream 6 les modern chef has created a fine art in making cakes, and for these delicious products of his art the public is willing to pay high prices. The chef in a prominent New York hotel uses a “‘bag’’ funnel in spreading whipped cream over a cake creation. This hotel takes good care of its em- ployees in the culinary department, and if one of them receives as much as a slight scratch on the hand he is promptly attended by the doctor. Cleanliness as well as skill are the principal first con- siderations, and, wherever the process permits it, mechanical devices are used to prevent hands from coming in con- tact with food. Comfort Before Style in China HINESE women have not yet learned to ask for fur coats in winter-time. In fact, they wear practically the same clothes in winter as in summer. In the most severe weather, however, they wear heating baskets under their cloaks. These baskets are plain wicker ones, such as we use for trash. Inside the baskets charcoal warmers are placed. They will radiate heat for hours. The charcoal is mixed with chemicals that generate oxygen, and thus the charcoal will burn constantly even though it is sealed in the containers. Looking at the picture below might cause one to marvel at the Chinese woman’s seeming disregard for appearance, until the Occidental bustle and crinoline are recalled.

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How a Five-Ton Elephant Learned Modern Dancing One of the Hippodrome stars George Powers, of the New York Hippodrome, taught five-ton Jennie, born in India, to dance. He played a dance record on the phonograph until Jennie got accustomed to it; then he stopped the phonograph and lifted Jennie’s front feet in time to his count At first she did not realize that she had to sway her whole body to Powers’ count. She thought it enough to sway her trunk and head. So he indicated to her what he expected by pushing her from side to side By As soon as Jennie understood that Powers wanted her to lift her feet in time to his count, she did it vol- untarily. He guided her steps so that, at a cost of much time and perseverance on the part of the man and the elephant, she learned just how to place her feet After her daily dance Jennie likes to shake hands with her master and dancing partner. She is immensely pleased when she has mastered a new trick and shak- ing hands is her way of telling Powers so At last Powers turned on the phono- graph again, and Jennie heard the record she had heard so often for so many days before her ‘‘ dancing” lessons began. Immediately Jennie started to dance in time to the music. Powers took her by the trunk and danced with her. She soon learned to match her steps to his 60 Popular Science Month’, Jennie’s reward is some delicacy she fancies. Here Powers is giving her an apple. Powers never hurts or intimi- dates his elephants. He says as soon as an elephant understands what is wanted, the big animal tries its best to do it

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February, 1921 Some New Jobs for the Clothes-Wringer Should it be idle six days a week? This woman knows all about the ordinary use for the clothes- wringer. It has probably never occurred to her that it can be utilized in other ways, as dem onstrated by the five pictures shown on this page. If the butcher cuts your bacon too thick for your particular taste, don’t be annoyed. Instead of sending it back and demand- ing more, slip it through the wringer. It will be thin when it gets through | A creased knitted tie, placed on a wet bath-towel may be run | through a wringer to restore it to its youthful freshness. This will eliminate the creases without injuring the tie one particle | * “Dip in cracker-dust | and fry,” reads the d recipe. If you have zi crackers in the house, 3 “ you can soon have the v required dust by run- ning them through the wringer If you have some hard nuts to crack, Pots and pans mean a great deal to let the gears of the wringer do the job many men who, before prohibition, F for you. Place your adamant nut be- kept out of the kitchen as much as tween its teeth and give the handle a possible. One of these men is here short, sharp turn. The meshing teeth seen squeezing the juice out of a bag will crush the shell of fruit

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handle-bars. Economy of fuel, ease of travel, and Floors covering large areas can be cleaned by an electric scrubbing-machine, which does the work of fourteen men Scrubbing Floors Electrically HE days of drudgery for the serubwoman are numbered owing to the perfection of a new automatic scrubbing- machine. It is portable, and is easy to operate. Attach the machine to any electric-light circuit and it is ready to use. A large machine with three operators has cleaned 5600 square feet equivalent to that performed by fourteen hand- serubbers. The work is divided into three opera- tions. First there is the scrubbing-machine, operated by one man; next is the mop-man with a water-absorber tank and mop to clean the scrubber wheel-tracks and finally a sub-station, consisting of a weighted stand carrying an auxiliary cable for use where the cable on the scrubber is too short to reach from the farthest point to be scrubbed to the nearest light-socket. The machines can be equipped with different brushes to suit different kinds of floors. MAGINE a streamlined body of an airplane running on three wheels, two in front and one in the rear, pro- pelled by an_ airplane propeller placed at the front. During the war the Ger- mans employed airplane propellers for the pro- pulsion of freight-cars. The land car shown in the accompanying picture is the invention of Leyat, a French engineer. The body of the car, which is set on three or four wheels, is streamlined so as to offer the least resistance to the air. In the original model the driver occupied the seat in the front cab placed directly behind the propeller, while in the later models the cab has been abandoned and the driver occupies the cock- in one hour—work speed are combined in this adaptation of the motorcycle. Traveling at thirty milesan hour this little machine can go more than eighty miles on a gallon of gasoline. foot-tracks; and Driving a Car by an Air-Screw pit with only his head showing above the top of the car. The driving mechanism consists of nipulated from the seat, A French inventor took a lesson from aviation and constructed a streamlined body automobile carrying an airplane propeller 62 Popular Science Monthly An Automobile for One O longer is it necessary to get out the big tourin:- car when only one member of the family wishes ‘o ride. In the garage, or in the basement is a little vehicle that will convey a single passenger in comfort. In a small space the complete mechanical equipment of an average automobile—the engine, gear-box, fiy- wheel, clutch, and shaft-drive—is arranged. The engine of 214 horsepower is of the standard two-stroke pattern, which has a heayy outside flywheel in which is housed the clutch, behind which is the two-speed car type of gear-box. The drive is taken to the worm- driven rear axle through a short shaft that runs into an aluminum casting containing the whole rear-axle equipment. The machine is started by a handle ma- and the control is from the The two - wheeled “‘automobile.”” Above is shown the compact arrangement of the mechanism. At thirty miles an hour the traveler can make eighty miles on one gallon of gasoline an eight-horsepower two-cylinder gas- oline engine of the V type, air-cooled and connected directly with the four- winged propeller. The en- gine is placed in the front end of the car, before the driver. Behind the driver’s seatis a seat for one passen- ger, whilethesharply taper- ing rear of the car contains a gasoline tank and space for tools and baggage. The rear wheels are used for steering, while the front wheels serve for braking the car. Tests show that a car of this construction can easily make fifty miles an hour, using about thre quarts of gasoline. With the brake system’ used a ear of this kind going at a rate of twenty-five miles an hour can be brought to a complete stop within fifteen feet. AC pi conscl detail noted pause Th out a the ti grim) his sk go av me ir in het Th boile! “I there Six | wate “a asket “a resp¢ H; the 1 huge way good bunk pum Ja wate ing ' As sup} that

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n- nt ng at on les in February, 1921 His Chance to Make Good With burnt hands he plugged the roaring, leaking boiler ACK HARDING glanced at every piece of machinery as he passed it —he had the born engineer’s un- conscious habit of taking in every detail. Nearing the switchboard, he noted the readings of the meters, then paused in the doorway of the fireroom. The heat of roaring furnaces rushed out at him as he stood staring down the tunnel-like space. ‘Allen!’ he called to a scantily clad, grimy-faced stoker. Allen, resting on his shovel, turned. ‘“‘The chief had to go away,” said Harding, “‘and he left me in charge. Is everything all right in here?” The stoker cast a glance toward the boiler. He hesitated uncertainly. “T was just going to report that there is something wrong with Number Six boiler, sir. She ain’t taking in water right.” ‘‘What seems to be the trouble?’ asked Harding. “Something wrong with the pump,” responded the stoker. A Leak in the Pump Harding entered the fireroom. On the right side of the aisle was a row of huge black boiler ends. Across the way were the bunkers, piled high with good steam coal. Between each bunker and the one next to it a busy pump worked. Jack Harding’s eyes sought the water-glass of Number Six; the read- ing was at half. As he approached the pump that supplied water for Number Six, he saw that the steam chest was leaking. In By Edward J. Veronda place of the steady clank of an honest pump, this one was sputtering and fuming crazily. The trouble was slight enough, but it must be remedied at once. If the damage was not repaired before the water in Number Six boiler was exhausted, the fire under it would have to be raked out, thus reducing the amount of steam fed to the engines. Some circuit would have to be cut out, and this would mean darkness in some part of the city that night—the very thing he had been given the opportunity to prevent! Stepping quickly to the engine- room, he seized hammer and chisel and hurried back to the pump. Dropping on his knees beside the pump, he set to work. The narrow space cramped him, the _ escaping steam burned his hands; even the While one other valve. just in time man was put drawing the fire, the worked _ fever- ishly at the defective With scalded hands he replaced it chisel grew so hot that he could hardly hold it. And when he finally plugged up the leak the valve did not respond! “She's Near Dry” There was something more than a leak, he realized; the trouble must be in the valve itself. ‘“She’s near dry,’’ came Allen’s swift warning. ‘‘She ain’t safe!’ His voice was husky and his eyes measured the distance to the doorway, though beyond this he showed no sign of wavering. ‘“‘Draw the fire,’ directed Harding. Despite this, Number Six continued to vibrate dangerously, quivering like an animal on the point of springing. Down on his knees, Jack was pulling the pumps apart; his hands were burned nearly raw. And he raged when they fumbled. Probing into the pump, he found the trouble at last—a stone wedged in the valve! He picked at it with his fingers, then with a screw- driver—it would not come out! He got up, ran to the bench for a new valve, and hurried back. The ruined valve came away, and he inserted the new one, quickly driving in the screws. The internal noise in Number Six was now a roar, and the safety valve let out an increasing scream. He tried to work faster, and as he worked he considered the matter a little hysteric- ally, though his hands worked none the less steadily. Driving home the remaining screws, he forced the valve of the cylinder in place. The noises from the belly of Number Six were dreadful now, and it was be- yond the- power of man to listen to them with a steady heart. As the boiler vibrated, the great steam-pipes vibrated with it. The walls of the building took it up and trembled also, not in unison at first, but finally in perfect harmony. Hard- ing felt as if this vibration would drive him mad. His very bones trembled to the tone of the boiler. He twisted the last nut, fumbled for the cock, and threw on the steam into the chest of the pump. There came a gurgling, choking sound, then a sharp click, the unmistakable noise of a working pump. He reeled backward. ing, Allen?” “Sure,” stoker. 99 “Ts she work- answered the “And if fire ain’t under Number Six she’ll be having the chills.”’ Jack stumbled out into the sunshine. He had made good—his opportunity was won!

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Installing Oil Fuel on a Great Ocean Liner

20 Men working in a haze hea¥k & coal dust.

og hor. 4 8 . ey Ce ee en - ee he front of one . as fitted pag as — —— ge

The same boiler-room with air fired furnaces worked by $imen

© Modern Publishing Company HE use of oil fuel on ships is, of course, not new, but the conversion of the Aquitania into an oil- burning steamship is a matter of universal interest. It comprised the removal from boiler-rooms of ash-expellers, furnace fronts, fire-bars, etc., weighing 300 tons. The weight of new material amounted to 745 tons. The main storage-tanks (in sections) extend along both sides of the ship for a distance of 369 feet. There are also Drawing by G. H. Davis three large athwartship tanks. The total storage capacity is 7780 tons of oil. The tremendous advantages of oil over coal are graphi- cally pictured in the drawing above. ‘Bunkering” is done in hours instead of days, the traveling speed is in- creased, and whereas in handling coal three hundred _stok- ers were formerly required, oil fuel can be taken care of by a crew of eighty boiler-minders. as k direc’ | ian diagr papel diagr squal repre settil is ree bloel time curic At a woo mad thes mad are nece scen is § hav peal ‘| itse out Aln sim ace and con abl can a |] pal

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avis February, 1921 Stage Settings from Blocks NOVEL but very effective stage setting first used in /{\ the production of French: plays in New York city, was based entirely on a system of angles. director for the French Players in New York is ready to plan a scene, he goes to his drawing-board and draws a diagram of the stage. Then he takes pieces of dark-colored paper, cut in the form of squares, and fits them on the diagram until he obtains the effect he seeks. squares of paper are all cut according to scale, each square representing so many feet on the stage. setting is all worked out on the drawing-board, the director is ready to set the stage for rehearsal. Once the preliminary work was done in the studio, it was only a matter of a few minutes to set the stage. Back of the stage are piled numbers of square blocks and several other blocks in the shape of steps. blocks, fitted together, make one large block, about four times the size of the plain square blocks. curious-looking blocks stand lattices, doors, and windows. Two of these steplike When the stage The little After the stage a AT. Beside these At the back and at the sides of the stage are permanent wooden pillars. made that they fitted between these pillars. They are all made in such a way that they are interchangeable. It is not necessary to have two sets of scenery, yet, when the stage is set, the scenes presented have an entirely different ap- pearance. This type of scenery lends itself to the production of both outdoor and indoor scenes. Almost any arrangement of a simple or formal garden can be accomplished with the blocks and lattices, while out of the combination of the interchange- able doors, windows, and blocks can arise a room suitable for a peasant’s hut or a king’s palace. The lattices, doors, and windows were so With these blocks is built up any scene that may be required, from drawing-room to garden, from a peasant’s hut to a king’s palace Mr. Barcroft of Cambridge, England, exercised on a sta- tionary bicycle during his imprisonment in a glass case In a Glass Case for Six Days N the interests of aviation, Professor Barcroft of Cam- bridge University spent six days in a hermetically sealed glass case. Nitrogen and oxy- gen were constantly pumped into the case, but the amount of nitrogen was increased while the oxygen was decreased. Thus the atmospheric conditions within resembled those experi- enced by aviators flying high. At the end of the six days blood was drawn from Mr. Barcroft’s arm and carefully examined. As for the effect on the experimenter, he became very restless toward the end. He was unable to sleep and lost his appetite entirely. Mount a Flashlight on Your Automatic 7 ANDS up! Quick!” A flash of Jight envelops the would-be burglar and blinds him. “Drop that gun!” Dazed by the light, he drops it. His captor, in the meanwhile, is Lon perfectly calm and sure of himself. The light that is blinding the burglar is a flashlight attached to his gun parallel to the barrel. Thus he knows that his gun is in line with the light. Furthermore, the flashlight is so A flashlight mounted on a gun will daze the would-be burglar. This particular flashlight is so constructed that there is a dark spot in the exact center 65 The flashlight is parallel to the barrel of the gun; thus you are sure of your aim constructed that there is a dark spot in the center. As the light flashes on the culprit, the dark spot stands out and shows the captor just where his bullet would hit should he need to fire. The burglar knows nothing of the man who covers him; that man may be smaller than the burglar, or he may be much larger. In any event, the burglar * decides not to take any chances and he therefore promptly gives up without a struggle.

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When Inoculating the Pig ERHAPS, at first glance, one would think that this was a device for pulling a pig apart limb by limb. It is not, how- ever. It is merely used to keep the animal quiet while it is inoculated with an anti- cholera serum by experts of the United States Department of Agriculture. Pigs are very susceptible to cholera, which is a highly infectious disease, and a continuous battle is waged against it by breeders everywhere to prevent it from spreading. Although the ‘‘operating-table’’ in the picture looks like an instrument of torture, it is not at all painful, but effectively pre- vents the pig from squirming while the inoculation is being made. So tightly is the pig held that he cannot move an inch; all he can do is grunt. Hooks that Will Hang © Edwin Levick Ice-Pegs to Start Sleds OU don’t need hills for bob-sledding if you are willing to ‘peg away.” Grasp a sharply pointed peg in each hand and dig them alternately in the ice. You and your sled will start to move slowly, but gradually you will gain momentum. The faster you peg, the faster you will go. A peg race is great sport, and many of the visitors at Lake Placid are peg-racing this season. The picture above shows the start of one of these contests for ladies. The onlookers enjoy it as much as the con- testants. Besides the excitement and pleasure in a race like this, it is also physically beneficial. Both arms are exercised equally. There are few sports in which this occurs. Gas from Peat EAT is now being used for the produc- tion of gas in especially designed pro- ducers. The yield compares favorably with that of coal, and many valuable by- products are produced. This method of using peat has been found to be the most effective, since it is not necessary thor- oughly to dry the crude material. Plants for the manufacture of gas from peat are in operation in Germany, England, Ireland, Sweden, and Italy. : Removing a Double Chin DOUBLE chin is the deciding factor 4 that places its owner in the heavy- weight class. It is the one thing most feared by women who have reached the stage known as “pleasingly plump.” Now, however,-there is a double-chin remover which can be operated by the owner of the chin in the privacy of the home. The machine is mounted on a small stand. Two wires extend from it to the sides of the band which the wearer straps under her chin. She turns on the current, and her chin, invigorated, tries to fall back into place, and once more electricity has jumped into the breach and justified its value in the household, each year finding it more strongly intrenched than it was the previous year. A Check to Keep Doors the Picture Straight NE crooked picture will make a room look untidy. There is a new picture-hook that is supposed to prevent this. It is made of strong, flexible wire arranged in a series of loops, with a sharp point at one end. The point is driven into the wall and the loops are adjusted until the picture is perfectly straight in its place. When you take the picture down and wish to remove the hooks, do not pull them out. Instead, pull the loops back- ward and forward a few times; they will break off and leave the stem behind them. from Banging HE easily attached door- check shown in the illus- tration will prevent the bang- ing of doors. It consists of an arm bearing a spring coil ending in a soft cushion. This arm is pivoted to a base screwed to the lock side of the door. The arm moves horizontally only, and is held in position by a tension spring that can be regulated by turning a set screw. At the same level a clamp | attached to the door-jamb so that it is ready to receive the padded end of thé door-check whenever the door is banged shut. N step A of acti com two larg line fror prir use T gros idly A a lk larg It i eigl nin Thi

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a= ctor LVy- nost the chin the the nall the ‘aps ent, ack has its ling the ors 90r- lus- ing- ring soft ited ock irm and sion ited p is » SO the eck ged I ebruary, 1921 Pictures Teach Dancing TOW there is a moving-picture +‘ device to teach people dancing, step by step. An expert dancer performs in front of a moving-picture machine, the action being so timed that he does a complete movement in exactly forty- two pictures. The pictures are en- larged and printed on paper. An out- line of each picture is sketched, and from these small cuts are made. The printer ‘‘pulls’” proofs and these are used in machines like the one above. The pictures are placed in succesive grooves in a drum that is rotated rap- idly, producing the illusion of motion. The Largest Belt Yet BELT like this is used in con- veying materials from one part of a large factory to another. It is the largest belt ever made for this purpose. It is one thousand feet long and forty- eight inches wide, and contains twenty- nine thousand feet of rubberized fabric. This is enough to cover the floor space of the largest gym- nasium in the country more than two and. one half times. 4 [ BARRETT Eee if "a © Harris & Ewing Moving-Day for This Monument of Lincoln ~HORTLY after Lincoln’s death a monu- ment to him was erected in front of the district courthouse building in Washington. For fifty years this tall monument with its life-sized statue of Lincoln on top, has adorned the vicinity of the old courthouse building. Recently the building was reconstructed, and now the statue is considered to be out of harmony with it! As a result, the statue is being moved to a more appropriate spot near the Poto- mac. Many of the resi- dents of Washington have protested against the removal, but what chance have mere individuals in an argument with a courthouse? A Collapsible Cane *VERYTHING has a time and 4 a place—especially canes. There- fore why not use a collapsible cane that, when shut, will fit in your pocket? Such a cane has been in- vented by Frank Kutwicz of Regina, Saskatchewan. You will always be able to carry it with you and take it out when circumstances permit. The cane comes in six sections, all hinged together like a folding foot-rule. Each section possesses a small blade that fits into a socket in the adjoining section. These blades make the cane rigid when it is erected. When you wish to fold the cane, you release the blades. Checking Up the Coal-Dealer HE coal-dealer must give full weight if his customer uses one of these coal-meters. The coal passes through a chute in the center of which is a rotating vane that is moved by the passing coal. A dial records how much coal has been thrown down the chute. On the device is arranged a counterweight that cuts off the passage of the coal unless a solid column is running through. If a small amount of coal were allowed to pass, the vane would not operate and the dial would not register. COUNTER- WEIGHY

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Rubber Caps Prevent Short Circuits 4 LECTRIC wires can be protected from any pos- sibility of becoming grounded or from being short-circuited. This is usually done with tape as an insulator, but some- times the tape is stretched until it becomes dangerously thin and, in time, more or less worn. The danger of short-circuit- ing is entirely eliminated by the use of small rubber caps easily twisted over’ the spliced ends of the wires. There are two sizes, and it takes only about threeseconds to put them on. When the tape is wound around the rub- ber cap, the insulation is doubly strong, and the chances of loss of current through contact with mois- ture or of short-circuiting is entirely avoided by this Carry Your Own Cigarette-Stand IF you go into a house where smoking is permitted but not indulged in by the mem- bers of the family, you are not apt to find an ash-tray on which to park your cigarette. But if you carry in your pocket the small cigarette- stand shown above, you need not depend on the ash-trays of others. The stand is made of silver, and is so con- structed that it will fold up and fit in your vest pocket. Unfortunately, no provision is made for the ashes that are bound to fall off the end of your cigarette; it is up to you to dispose of them yourself. We would suggest that you carry a small recep- tacle in another vest-pocket and use it for your cigarette simple method. ashes. Drill-Presses and Production SHOWN below are drill-presses that represent a radical departure from the ordinary type. The bushing-plates are attached to the drill so that they may be adjusted vertically. The jig, which holds the casting to be drilled, rolls on V-shaped rails from machine to machine. The first machine drills the holes, the second reams them, and the third counter- bores and countersinks them. A continu- ous procession of castings passes under the drill. At the end of the row, the finished casting istaken out of the jig, and the jig is re- turned on another rail to the first machine. Taking a Sample of Pavement “THESE men are not drilling a well as you might think. No; they are obtaining a sample of pavement so that they may take it to a laboratory to put it under tests. This machine displaces several men working with pickaxes and chisels. The drill is made of chilled steel and has steel shot as its cutting medium. It is placed in contact with the pavement, flushed with water, and set in motion. It cuts a perfectly round hole, and the con- crete from this hole is used in the tests that follow. The concrete is removed in the form of a core. This is tested for thick- ness, wear, abrasion, and resistance. A Mechanical Mule [ IKE a regular mule, this mechanical 4 mule is driven by reins. The ‘“‘reins” are really control cables that are connected with the electric motor that drives the mule. Instead of saying ‘“Giddap,” the driver merely operates a switch and the mechanical mule, unlike its namesake, starts off without any delay. This little machine is an infant mine locomotive weighing eighteen hundred pounds. It is but twenty-six inches high, and this enables it to get in parts of a mine where mules could not go. It will also travel over very light track, even though it be poorly laid. Tt The this pub chri bod kno T pon ser\ the T her It i wis! G ma’ tim mal for WO! is ¢ eye bus alw will bec nev

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re ut m- ay ur ur te- ed Lys ide on- old est 2p- cet tte cal s”” ed he he he Ke, ine ed th, ne iso Is This a Boat or Is It an Airplane? HIS looks like a cross between a Chinaman’s junk and a seaplane. The electrical engineer who designed this mysterious craft refuses to tell the public just, what it is all about. He has christened it the What-Is-/t. Every- body who has seen it is interested in knowing just what it is to be used for. The superstructure rests on three pontoons or floats. The stern float also serves as a rudder, and it is turned with the wheel in the bow. The boat—if we may call it such—is here shown starting on its trial voyage. It is a mystery to us, but we heartily wish the inventor every success. Blowing Glass Eyes to Order LASS-BLOWING as an art goes back to ancient times, but its application in making artificial eyes belongs to modern times. The art is delicate, especially in the matter of obtaining the right tint of color for the iris. Eyes that do not match are worse than none at all as far as appearance is concerned. The war caused a huge demand for glass eyes, and many manufacturers are kept busy making them. The enamel on the front of the eye must always be perfectly smooth or the eyelid will become irritated. When this enamel becomes worn, the wearer should get a new eye. A Hot-Swaging Machine to Make Heavy Tubing N ANY advances have been made in the methods of forming metals by cold- swaging processes, but the hot process has been developed to be used principally on heavy work where a great deal of reduction is desired without annealing. A new ma- chine handles tubes as large as five and a half inches in diameter and solid rod of two and a half inches in diameter. As the spindle rotates, the hammer- blocks are thrown away from the center by centrifugal force and the dies open. The twelve head-rolls project toward the center beyond the path of the hammer-block rolls and as the rolls pass each diametrically opposed pair of rolls, they are forced toward the center of the: machine and carry the hammer-blocks and swaging dies with them. As the head rolls are passed, the hammer-blocks and dies are thrown automatically apart again. The work is held rigidly and concen- trically with the dies by pneumatically operated clamping jaws bolted to a saddle which moves forward and back- ward on its slide- ways by hydraulic pressure. Feeding is controlled by a hand valve. The holder and cover are self contained and hung on a hinge so that easy access to the dies and working parts of the maehine is se- cured. 69 Diamonds Manufactured—This Time in the Movies ON’T get excited. The diamond market is not wrecked yet. It will probably be some time before it even begins to totter. If movie-men really knew a process for the manufacture of diamonds, the production of movies would no longer interest them. This formidable array of mysterious- looking apparatus was assembled at great expense for a serial picture. From the movie-man’s standpoint, the illusion is perfect. From the scientific man’s stand- point, it is just about what a movie- man’s idea of a diamond-producing apparatus would amount to. A Drill-Press of Many Uses place of the ordinary table, this little drill-press has a revolving member carrying on it different forms for the vari- ous classes of work. There is a V-block, a cup, a point, an angle, and a flat table. Any one of these may be brought into posi- tion by merely turning the casting which is mounted on a shaft. The movable member locks into position when any one of the forms is in exact alinement with the drill in the spindle. A man is here shown using the V-block in drilling a hole through a rod. Pins, shafts, collars, balls, or angular pieces may be drilled by bringing the proper form into position.

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Why the Chinese Are Cutting Their Queues \ ITH the fall of the Manchu dynasty came the wholesale barbering of queues. The barbers of China were very busy people, and their art is now develop- ing to that of the normal tonsorial stage. In the early part of the seventeenth century, when the Manchu Tartars invaded the country, they found the men wearing long hair tied in a knot upon their heads. But on the conquest of the country the inhabitants were compelled to adopt the queue, or long pigtail, often greatly lengthened artificially by employing long strands of black silk thread. To celebrate the fall of this dynastic rule the Chinese were eager to have their queues removed, after the lapse of three centuries. Skull Rock in Colorado HERE are several famous rocks in various parts of the country that are shaped like the human head; but you must go to the Rocky Mountains if you wish to see a rock that is shaped like a skull. “Skull Rock,” as it is called, is located near Canyon City, Colorado. It juts out from the side of the mountain on which it is located, and is clearly outlined against the sky. If Hamlet had seen this monstrous skull, how he would have soliloquized! At Canyon City there is a road known as the “skyline drive.’’” As you travel along it you see a range of mountains outlined against the sky. Skull Rock stands out sharply, with its eternal reminder of the transitoriness of man’s life.

© Kadel & Herbert Picking Up Marbles with the Toes to Cure Flat Feet en you flat-footed? If you don't know, the next time you take a bath, observe the impressions that your wet feet make. If your feet are normal, there will be a narrow line from heel to toe on the outside; if they are flat, the entire bottom of the foot will show. How can you correct flat-footedness? Buy a handful of marbles, place them in two rows, and start picking them up with your toes. To do this you must curl up your toes; as a result the muscles of the feet will be exercised and thereby strength- ened. The Old Horn as a Funnel iF the electrical end of your automobile horn is irreparably broken, find new uses for the various parts. Take, for instance, the cone-shaped horn proper. It may be used as a funnel. Your car is apt to run dry when you are miles from a garage. The nearest farmer will give you a pail of water, and the horn- funnel will guide the water into the radiator.

How the Pioneer Automobiles Were Started UT her in gear and push. That’s one of the remedies for a car that won’t start and a good old-fashioned remedy, too. For that’s how the first automobiles ever made had to be started. Above you see a Peugeot automobile that was built in 1894. It is still in exist- ence and is occasionally exhibited at the French automobile shows. The engine is full of life, even though it is more than twenty-five years old, and a few healthy pushes will start it off. The wheels are much larger than the wheels of the automobiles of today, and the tires are made of solid rubber. This automobile was one of the first to be built in France. Beheaded by an Earthquake NCE there was a woman who hated the thought of passing out of this world without leaving some concrete image of herself behind. And as she had plenty of money to satisfy her whim, she had the concrete image made. It was dressed con- cretely in clothes that were stylish at the time —a tight-fitting coat and a wide skirt. For years, now, it has been sitting on the edge of her tombstone, which is situated in a Los Angeles cemetery, holding a concrete satchel in its hand. Recently, however, there came an earthquake which respected neither tombstones nor images. It knocked the head off the concrete woman, and deposited it alongside of the satchel. ‘All the king’s -horses and all the king’s men”’ will be needed to put her together again. Popular Science Monthly

Februa It’s T Te <VER ~ that color oO percolat pe! ‘orat gardless though has beer \ tin stance, tured, W pose. just sue made dangles small « opens t If you I hot wat utes, th come te ill We is said It trave 62 mile gallons A mi priately It migh physicis Thes while t wings n

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February, 1921 It’s Tea-Ball and Teapot Too Me one knows that the flavor and color of tea-leaves will percolate through any per/orated container, re- gardless of its shape, al- though heretofore a ball has been the usual shape. A tiny teapot, for in- stance, if properly punc- tured, will serve the pur- pose. Below you see just such a teapot. It is made of silver and dangles at the end of a small chain. The lid opens to let in the tea. If you hold it in a cup of hot water for a few min- utes, the water will be- come tea. The Smallest One-Man Airplane VV Baers only 220 pounds and cost- ing only $1200, the Pischof airplane is said to be the smallest flying-machine. It travels the aerial highway at a speed of 62 miles an hour and consumes but 11.2 gallons of gasoline an hour. A machine of this type might appro- priately be called a “runabout” of the air. It might prove of practical value to country physicians whose practice is extensive. The small engine is a remarkable feature, while the small space taken up by the wings makes the plane easy to house. Acrobatic Japanese Firemen > gk a population of nearly three million people and with houses of generally flimsy construction, the city of Tokyo, Japan, requires a well drilled and efficient fire department. Because there are no skyscrapers, the fire-fighting apparatus is remarkably simple compared with that of American cities. But the skill of the firemen as acrobats cannot be doubted when one witnesses them engaged in a practice drill. Here they are seen poised in difficult positions on the top of tall ladders, a feat often performed on the stage by Japanese acrobats in foreign countries. Numbers of us have seen these acrobats perform upon the top of ladders in an upright position. Eye-Strain at the Movies NVESTIGATION has shown that eye- strain in moving-pictures is often caused when one has to raise his head at an angle greater than thirty-five degrees to see the top of the screen. He should not have to turn his head sideways more than twenty- five degrees. The body of the theater should have a soft, even light, approximately that given by a candle burning at a distance of forty degrees from the eye of the observer. A Beer Sign for ¢, the Illiterate ; you } OOK closely at the ~ picture and will notice a sign | entitled ‘‘Bor es Sar,’ t and above these words a picture of seven foaming glasses of beer, and a tray on which are seven beer bottles! This store is located in Budapest—-a long way from the United States. The reason for this artis- tic beer display is that many of the poorer people in Budapest are unable to read. ‘Bor es Sor’ would mean no more to them than it does to us, were it not for the picture. below He Put a Canoe on a Chassis HIS is not an amphibious automobile, as you might think. It is merely an automobile chassis fitted with a canoe-body. The owner wanted something that looked different, so he bought an old canoe and fitted it over the chassis of his car in the manner shown. He not only had a cheap body but a car that attracted attention wherever it went. A glance at the picture, however, does not speak much for the com- fort of this freakish-looking apology for an automobile. Its four passengers appear to be rather crowded for space.

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Do It with Tools and Machines Industrial weapons forged by man’s inventive mind By changing the position of the carbon so that the arc leaves its crater at an angle of 120 degrees, and by rotat- ing the carbon rod, the spot- light #luminating power is increased 40 per cent Clamp this rail-cutting ma- chine to the rail, adjust the saw-blade, andturntheswitch of the motor; the machine will do the rest Popular Science Monthly No belt is required for this drill-press, driven by a ver- tically mounted motor. The drill is attached to the shaft. A treadle controls the motion One of the centerless cylindrical grinders will prove of great ad- vantage in all cases in which accuracy and speed are essential This multiple spindle drill-press is equipped with a re- volving table that indexes for each successive operation of rough drilling and reaming of connecting-rods. The machine head is returned to position by air-pressure \COUPLING WITH - YIELDING SPRING COILS Flexible friction coil couplings make it possible to couple shafts with an offset of 1, inch or a deviation in alinement of 10 degrees The first few teeth of this tap do the cutting, while the others act as a lead screw which removes the chips that would otherwise bruise the thread upon removal of the tap If the side-cutting jaws of this plier become damaged they can be removed and a pair of new crucible steel jaws can be put in their place This tool for heavy service on lathe, planer, or shaper is prac- tically the equal of -hand-forged solid tools, and is more economical With a machine like this a workman can stamp the name of the manufacturer on 2500 pairs of shoes in a single day a Febru AT Is the | natin their WwW they are 1 ding olde broc T wine the mat It time

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onthly yy ; Na- the tch ine February, 1921 Keeping Up with the March of Science Facts for the man who wants to know A Tree that Meets Every Need N the islands of the southern seas, the coconut palm supplies all of the needs of the members of society. It supplies the natives with lumber to build their homes, their boats, and their utensils. When the leaves of the tree are young, they are eaten. When they are old, they are woven into hats, clothes, baskets, bed- ding, paper, and thatch. The ribs of the older leaves are made into spears, arrows, brooms, torches, and paddles. The flowers of the tree give the natives wine, vinegar, and sugar. The fruit of the palm yields oil, foods, cord, and matting. It is said that even the roots are some- times used as food. The Scientific N American missionary who recently ~ returned to this country credits the ancient Koreans with being scientists and inventors. He claims that they used iron- clad warships against the Japanese as early as 1597. They used cast type long before any other people, and they were employing gunpowder as early as 200 B.c. Their astronomers thought out the operation of the planetary system thou- sands of years ago. They invented the magnetic needle and were the first people to underglaze pottery. They also intro- duced carpentry and architecture into Japan, and were the first to excel in the manufacture of silk. Bronze and brass foundries were in operation in Korea at the beginning of the Christian era. It has been said that Korean engineers designed and constructed the great wall of China. Koreans What Makes Milk White? AVE you noticed that some milk is white, some has a bluish cast, while cream is yellow? Milk in a normal condi- tion contains many millions of minute spheres of fat, and these act as little mir- rors, reflecting the light in all directions. The more numerous masses, as in the com- pact form of cream, produce an absorption of a part of the light, reflecting the yellow rays. When the masses of little spheres of fat are less numerous, as in skimmed miJk, the liquid becomes more _ transparent, and as there is less reflection the color is bluish. It is interesting to coyjparetiis phenom- enon of light wit the milk-white and the dull rings oOfethe distant planet Saturn. Through thé telescope this same principle of reflection from small bodies is apparent. The more cOmpactly formed portion of the ring that sUrrounds Saturn shines with a pure white tight. Here there are countless millions of! little moons flying around Saturn, reflecting the sunlight as do the spheres of fat in the rich milk. As these masses become less compactly grouped on that portion of the ring farthest from and that nearest to the planet, we can see the dark sky through the ring. On its inner and outer edges it is transparent and thus appears dark. What Is a Dollar’s Life? DOLLAR does not go very far nowa- days, but the journey it makes must be a hard one if we are to judge by the wear and tear upon the life of the average dollar. According to a table compiled by the Treasury Department, a dollar note lives but 2.03 years, while a_ silver certifi- cate stays in circulation but one year. A five-dollar note stays in service 2.49 years, a ten-dollar note 3.57 years, while a twenty- dollar bill lasts 5.94 years. A hundred- dollar note lives as long as 6.15 years, while, curiously enough, a five-hundred- dollar bill lives but 3.78 years! But this is a long time compared with the longevity of a ten-thousand-dollar note, whose period of service is actually but .16 of a year. The notes are by no means worn out in use, but are freely retired on becoming unserviceable. Radium Used in Pottery ATER containing radioactive com- pounds is used as a curative agent for certain illnesses. Mere contact with such compounds for a sufficient length of time will make water slightly radio- active. Pottery is now manufactured which has in it a small percentage of radioactive material. This is mixed with the clav and baked in the kiln. Water left in pottery of this nature for a short time will become radioactive by “induction,” and a health- giving drink is made. Such water may also be employed in the watering of plants with good results, since the presence of a radioactive compound near the roots of a plant is very helpful to its growth. Do Frogs Like Music? [D'P you ever wake up in the country, on a summer night, and hear the frogs saying kerchunk? Probably it would be more sensible to ask if you managed to get to sleep while they were croaking. An Englishman claims that frogs can be charmed with music in much the same manner that a snake may be charmed. He tells of having held four frogs absolutely spellbound with piano music. Science has made another great dis- covery, and it may be of some benefit to mankind. 73 Moisture X-Rays the Wall bape up at the ceiling and at the wall 4 of your room and see if you can locate the skeleton of the lathes back of the plaster. If the room is of suitable location and temperature, the phenomenon can be observed. Investigation shows that the black markings are the spaces between the lathes, just as one might look between them into the dark shadows of the attic above, or the dark background between the plaster and the outer wall. Curiously, this effect cannot be observed in interior rooms, or upon the ceiling of a lower room where the upper part of the house is kept warm. Temperature and moisture are found to be responsible for the effect. The warm air of a room contains much moisture and also fine particles of dust. The attic is usually cold, as also is the air-space back of the plaster of the outer walls. This causes the moisture to condense on the spaces between the lathes where the temperature difference is greatest, and in condensing it deposits the particles of dust. Making Use of Lizard Skin “THE lizards of India—and India has a great crop of them—are hunted for their skins. Women’s and children’s shoes, purses, and handbags are manufac- tured from them. These articles have been found to wear as well as calfskin or glacé kid. The average skin is two feet square and is worth thirty-two cents. A_ pair of shoes made of lizard skin costs four dollars. Why Piants Freeze to Death for scientific as well as for practical reasons, the question as to the exact manner in which the death of plant life is caused by freezing is of great interest to scientists. A number of explanations of the phenomenon have been given. Some investigators were of the opinion that the freezing or crystallization of the water contained in the cells caused a dis- ruption of the plasma membrane, which is extremely sensitive. This theory was not accepted by others, who maintained that, the plasma being a viscous liquid, it may be assumed that the membrane would be able to- yield sufficiently to avoid rupture. Other investigators claimed that it was not the freezing, but the thawing out, especially rapid thawing, that destroyed the cells. This opinion is correct only in part. It is undoubtedly true that rapid thawing may destroy frozen cells which with gradual thawing would have sur- vived. The problem is greatly complicated by the fact that certain plants survive even a severe frost and revive after they have been

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frozen hard and stiff for a considerable period, while other plants, especially those coming from the tropics, are killed by temperatures only slightly above the freezing-point. A new theory assumes that the freezing removes part of the water contained in the colloidal living substance, and that the water thus separated cannot again be absorbed by the colloid. Another effect of the freez- ing undoubtedly is that mineral salts, sugar, and other substances contained in solution in the cells are deprived by frost of part of the water in which they are dis- solved. The solution hence becomes too saturated. > Indirectly the frost injures plants if the ground is frozen hard, while the sun keeps the plants themselves below freezing tem- perature. The roots and rootlets, frozen hard, are unable to supply the plant with water, and the plant wilts. Severe cold may cause disruption of the cells in the interior of the plants which in some cases may cause the death of the plant by the drying up of the injured tissue. Trees are often split by extreme cold, but otherwise healthy trees are seldom permanently injured by the cracks. Ancestors of the Big Trees AMPLE evidence is to be had that Cali- 4 4 fornia’s great trees, the sequoias, whose first sprouts appeared above the soil at least seven centuries before the advent of our Christian era, are the survivors of a widely distributed race that millions of years ago spread over a vast area of the world. Probably more than eight million years ago these trees, the redwoods, were leaving their time-resistant cones as records which to-day are unearthed as fossils. Beneath their lofty branches giant reptiles erept or flew. The ancestors of our sequoias towered above the ferny underbrush that preceded modern plant life. There were no flower- ing plants in those days; they developed later, and are the food sources of civilized man. In the shade of the great trees the giant reptiles came and vani.ned, the little five-toed horse developed into the modeih horse. The race of trees survived and watched the evolution of the whole animal species up to the age of man. What a re- markable history the redwoods could tell of life on our planet! Watch New York Grow HE 1920 Census Report shows that New York city has within its limits 5,620,048 inhabitants. This means that in the past ten years 853,166 strangers have come to the city to live—a rate of more than 85,000 a year. This inerease, averaging more than 17,000 families of five to the family, means that 142 apartment buildings, housing 120 families, would have to be built each year to house all these newcomers. This has not been done, hence the serious lack of housing that threatens the great city. In New York state there are now 10,384,- 144 people, an increase of 1,270,530 since 1910. It can be seen that New York city has gained practically two thirds of this increase in the state’s population. Cement Joints for Iron Pipes EAD is usually employed to make joints in cast-iron water-pipes. Lead has recently been replaced and cement has been brought into use as a su)Dstitute. This experiment was conducted by a water company of San Francisco, Califor- nia, and it is claimed that a great saving has resulted. The cement can be rammed in place much more easily than the lead and considerable reduction in cost is effected. Animals that Glow AMONG the interesting phenomena of organic life is the luminescence or phosphorescence of certain animals and plants. The light-giving power of so-called lightning-bugs, of certain organs character- istic of deep-sea fishes, of certain micro- organisms that cause the phosphorescence of the sea in tropical and sub-tropical lati- tudes and of decaying wood belong in this class. It was originally believed that the glow- ing and decaying wood was caused by some chemical process of decay; but recently investigators, among them Brefeld and Molisch, ascertained that the mycelium of certain fungi of a low order produces the phosphorescence, and the decaying wood is concerned in the process only to the extent of supplying the nutriment for the develop- ment of the mycelium. The exact process of light production has not yet been ascertained, but it is known that only in the presence of free oxygen is the phosphorescence at all possible. According to the theory advanced by Molisch, the cells of the mycelium produce a substance that he calls photogen and that gives light in the presence of water and free oxygen. Saturn without Its Ring HE man in the street may notice the planet that some one has pointed out to him as Saturn. He has heard of the re- markable flat ring that surrounds this dis- tant world. If he takes a look through a telescope any time wiitil February 22, ex- pecting to see the ring, lie will be disap- pointed. On November 7 the earth passed through the plane of Saturn’s ring, and now we are on the unilluminated side of it and can see only its dark shadow where the ring crosses the ball of the planet. It takes Saturn almost thirty years to make a trip around the sun, and twice in that interval the earth passes through the plane of the ring. The event is of much interest in attempts to solve some of the problems concerning its structure. With a large telescope a very thin bright line can be discerned at the time the ring is exactly edgewise toward us. The Pale Eyes of City People ROLONGED absence of sunlight tends to produce pale hair and colorless eyes. Both vegetable and animal coloration de- pend to a proportional degree upon direct 74 Popular Science Monthly sunlight. Note the albino fish of caves, the white shoots of plants eternally shielded from the sun. In like manner the eyes o/ a human being would become less rich in color, as also would the skin and hair jf he lived constantly in deep shadow. Based upon this theory, one might ex- pect the dwellers of city apartment-houses eventually to develop these characteristics to a degree. A French professor has told the Academy of Sciences in Paris that after long residence in the city an individu:|’s eyes grow paler and the hair undergoes bleaching. Dark eyes are less sensitive to light than pale ones; hence the dark-eyed people of the sunlit tropics are better able to endure the stronger light without pain. The Life of a Star 1 we examine the light of a number of stars, some will be found to be white, others yellow, and still others red. In certain white stars hydrogen and helium gases are conspicuous, and there is little indication of metallic elements. These are the youngest suns of the universe. In another kind the helium is less pro- nounced and the hydrogen is strong, while the metals have made their appearance. In still another kind, such as the sun, the metallic elements, such as iron and titan- ium, are present in the atmosphere of the star. At last we come to the kind of star that shines with a red glow, and whose atmos- phere contains metallic compounds, ox- ides of metals, and cyanoger There are many reasons for supposing that a star is formed through the condensa- tion of primitive matter diffused through- out space. Compactly forming under gravity, there are frictional shocks and collisions that greatly raise the temperature of the mass. The star grows hotter as it becomes more compact until the heat pro- duced becomes less than that radiated away through space. Then the star begins to cool until it finally becomes extinct and dark. Buying Scientifically ‘THE engineer or architect must be con- tinually on the lookout for errors arising from the use of unstandardized material. His specifications may permit the use of several kinds of lumber, but he is at a dis- advantage because he has no means of knowing from what region the wood will be secured, and therefore what sizes will be supplied. This frequently is the cause of dis- crepancies and inaccuracies in his design. The technical man becomes familiar with grades ‘“X, Y, and Z” of a certain species of umber. There comes a time when he is unable & secure that species and has to use the same nameu grade of some other kind of lumber. This he max find totally dis- similar and unsuitable. \ There should be a naticnal instead of a regional standardization of sizes and grades of lumber. It would result in greater efficiency in distribution and use, reducing the cost of labor in handlin % and simplify- ing the lumber-dealers’ niultiplicity of stock items. ‘ebrua

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er of vhite, and there 1ents. verse. pro- while ance. 1, the titan- yf the that Emos- , OXx- osing ensa- ough- inder and ature as it » pro- iated egins t and ' COn- rising erial. se of a dis- ns of rill be il] be dis- sign. with ecies he is Oo use kind r dis- of a rades eater ucing plify- y of ‘ebruary, 1921 Housekeeping Made Easy Here is a wooden tie-stretcher— two arms hinged at one end. You slip it into the tie, arms, and hold it over steam spread the Need some new saucepans? Buy, instead, a detachable handle and adjust it to an old can. In this fashion you will have as many saucepans as you have cans What can you do when a nail-hole outgrows the nail? Wrap some cotton around the nail and soak it in glue. Then put the nail back This is the new electric floor-polisher. A small motor revolves at the rate of one hundred and sixty revolutions a minute and carries with it a circular brush One of the best things a spool does is toroll. But this new holder _at- tached to a safety- pin enables you to fasten the spool to your dress. while you sew How can you pre- vent a box of cigars from going dry? By placing a small water-soaked por- celain block inside the box. This white block is en- cased in rubber pri ~ door. There with hinged arms Hang your ironing-board on the is a metal holder that can be adjusted to fit any ironing-board Don’t wrap a cloth around a hot dish when you wish to carry it to the table. Rather, place the dish in a wire frame like the one above, and protect both dish and table To prevent a glass utensil from cracking when boiling liquid is poured in, slip a steel knife under it She lowers the mop into the wire basket, slips the half ring over the mop-handle, and pulls the handle forward, squeezing out the water 75

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The scoop of the body is pushed back by the truck into the material to be loaded and the load is automatically taken aboard A Motor-Truck Body that Loads Itself YOMETHING new in the way of S self-loading motor-truck bodies has recently been invented by Fred- erick Wengraf. The body of the truck is mounted on rollers, which run in special tracks on the truck chassis frame and permit the body to be pulled backward off the chassis on to the ground by means of a cable and drum operated from power taken from the regular truck engine. The rear end of the rollers curves down Handcuffing a Car to Prevent Theft A UTOMOBILE thieves have been more and more reckless in the past year or so. Among the many devices that have been invented to combat their depredations, one of the most effective is a veritable handcuff which is fitted around the vertical pin of the steering knuckle and locked in place so that the front wheels can turn neither to the left nor to the right. The apparatus consists of two hinged steel jaws with wedge teeth. A double- headed bolt operated by a special lock holds the jaws in place, thus making the steering knuckle rigid. The entire mechanism can be carried in the coat pocket when not in use and can be locked to the steering-wheel or taken off in a few seconds. One advantage of the lock is that it - city ordinances in that its use does not make the car immovable, which would constitute a danger conforms to all so that the body is lowered gradually. When on the ground, the body is pushed backward into the bulk ma- terial to be loaded by backing up the truck chassis. The body tailgate, which is pivoted at the bottom, is auto- matically controlled by a _ separate drum and cable so that it can be swung downward to act as a scoop. The body may be entirely discon- nected from the chassis in thirty seconds. (PREVENTS €: LOCKING-BOLT YALE LOCK When this lock is snapped on the wheel, the car can be run only in a straight line in cities in case of fire, but permits it to be moved in a straight line either forward or backward. however, cannot be turned so long as the lock remains in place. The front wheels, truck. 76 A ENGINE EXHAUST THROUGH TANK ZING Printer’s ink is delivered in bulk by this tank- The ink is discharged by gravity and pumped from cellar to roof Motor-Truck Tanks Delivery Printer’s Ink HE first truck to be employed jn carrying ink in bulk is show: jy the illustration below. It is used hy y Hoboken, New Jersey, ink manu- facturer to deliver ink to severa! of the New York city daily newspzper plants. While the carrying of ink in a truck tank at first would seem comparatively simple, it presented two problems which had to be solved before the method was made practicable. The first of these was to prevent the ink from freezing in cold weather. This was solved by running the exhaust pipe from the truck engine through the bottom of the ink-tank. The second problem was to get the ink from the truck tank to the storage tank usually placed on the roof of the printing-plant. When the ink was delivered in barrels these were raised to the roof in the freight elevator. But with the ink delivered in bulk in 750- galion lots, the use of barrels for unload- ing was impracticable. A new method had to be devised, and so a filler pipe was run from the roof tank to the sidewalk. The ink is allowed to run into this pipe by gravity and is then lifted to the storage tank by a pump in the base- ment of the printing-plant. al ROOF STORAGE “ad | 4 , =. OUTLET 1 aia ‘oot DISCHARGE Popular Science Monthly F In ® that, were had | you could home Th write solut sity 1 Af impr possi was the | the ° fan 1 maki ing f was ried slack belt cross give drive In mint ator and latio thek reple norn an Jam agall A whic of 1 part’ load: truc] moré may from are ¢ of t whic Tl oper driv

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yi ‘ on ‘Aly liver yed in Wh in 1 | ya Nanu- Tal of Paper truck tively blems e the The e ink This it pipe h the et the OTage of the . Was sed to But n 750- nload- ethod * pipe o the Oo this ted to base- February, 1921 In an Emergency This Is a “Hot One” i, while using your automobile on ] a very cold night, you discovered that, during a short stop which you were obliged to make, your radiator had become “‘froze up,”’ what could you do to thaw it out so that you could safely run the engine and get home? This was the problem which the writer encountered recently, and its solution again proves that ‘“‘neces- sity is the mother of invention.” After considering a number of impracticable and more or less wild possibilities, the logical conclusion was that the engine must furnish the heat wanted. This in turn led to the ‘‘big idea”’ of driving the cooling fan in a reverse direction and thus making it a heat- ing fan. Theidea was quickly car- ried out by first slacking the fan- belt and then crossing it to give a reverse drive to the fan. Inless than ten minutes the radi- ator was thawed and water circu- lation resumed; the belt was then replaced in its i sl normal position Se Tt and ‘Home J 9 _.. By reversing the fan the warm air ames, Was from the engine is blown against again possible. LOADING mechanism has re- cently been placed on the market which may be applied to any make of motor-truck. The apparatus is particularly adapted to SA EINER gee «2s = apueenaan” ee 3 #) Te NAM the radiator, thawing it out A New Logging-Truck Loads Itself OW would you like to have a suite of rooms on wheels, so that, if you wished to take a long trip, you would be able to take your hotel accommodations along with you? That, in effect, is what a Mid-West- erner proposes to do. He has had built for him a motor- truck and trailer combination that has all the comforts of a stationary home—and with almost as much actual room clutch and pressing down a pedal, the power being secured from the ordinary propelling engine of the motor-truck on which the apparatus is mounted. If you live in an apartment on wheels, moving loses its terror and becomes a pleasant diversion, a source of delight at all times Traveling with a Furnished Apartment in it as many a modern city apartment. On the motor-truck he has had con- structed a “‘living-room,’’ which also does duty as a dining-room. The trailer carries the sleeping-room and bathroom. Between the living-room and bedroom of his traveling ‘‘apart- ment” he has a passageway, somewhat after the design of Pullman-car tele- scoping vestibules. It would be quite possible for a large motor-truck to tow two or more trailers, each carrying one room, connected by flexible vestibules. and Trailer The size or the shape of the logs do not affect the work of the machine. Logs may be loaded from either side of thetruck. In addition, other unwieldy objects required at a lumber- loading big logs on motor- trucks or trailers. Further- more, the same mechanism may. be used to pull the logs from’ the place where they are cut to length to the side of the truck or trailer on which they are to be loaded. The entire apparatus is operated by the truck- driver simply throwing in a camp can be handled equally well. The apparatus consists of a framework for supporting the logs; a winding-drum and a mechanism for turning the drum by means of power taken from the truck engine. The supporting framework takes the place of the ordin- ary truck body and consists of four I-beam sills set equally distant crosswise of the truck frame at the back of the driver’s seat. The winding-drum is mounted on a shaft carried at the ends of Logs of any size can be loaded on the truck or its trailers by utilizing the power of the driving engine of the motor-truck. The dia- gram on the left shows the detail of the arrangement of the mechanism which is con- trolled by the driver. The logs are hauled by a chain which is wound on a drum 77 the cross sills and parallel to the centerline of the truck chassis. The power is trans- mitted from a driving fric- tion disk on the shaft to a driven disk at right angles to it.

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New and Practical Accessories for the Passenger Automo- bile and the Truck Popular Science Mon hly % / ge ie [= | a\ 2 * : \ Ay This lubricator, which is made in the shape of a tomahawk, can be forced between the leaves of the automobile spring by a few taps with the hammer. It feeds the grease from a hollow handle Bus-trailers help to solve the passenger-transportation prob- lem. The bus shown here has reversible and rattan-covered seats for thirty persons, and is arranged similarly to a street- car, with doors at the side By paying an annual fee to the electric-light company of London, Ontario, you obtain the ‘right to tap the electric current at any of the plugs installed at numerous points, for heating your radiator in cold weather In one of the new models of a cer- tain American car the bow supports of the top at the rear corners are removable. They are carried in the tool-box when the top is up With this extension wrench-handle, nuts in places reached with difficulty may be turned with any flat or S wrench without resorting to a makeshift Carbon scrapers may be used to advantage for fastening or un- fastening screws in places inac- cessible to straight screwdrivers The scrapers are made of the best materials and will stand hard wear Babbitt-faced shims for automotive bear- ings are among the most recent improve- ments. The shims are locked in the man- ner shown to the brass part of the shims Nuts, bolts, or tools accidentally dropped into the drip-pan of the engine are easily recovered without loss of time by means of a magnet attached to a wooden handle Instead of crawling under your car to oil the springs, take a spray- gun filled with kerosene and a little powdered graphite and spray the mixture between the ~ aves. The kerosene will eairy the lubricant Fé bruary, Durin eight-f engine movec a truc to Tol enty ! ret 0 OR

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February, 1921 During a recent railroad strike the eight-ton combination boiler and engine shown here could not be moved by raiJ. It was loaded on atruck and carried from Dunkirk to Toledo, Ohio, a distance of sev- enty miles, without mishap By pushing down the small thumb lever, the rubber washer is pressed against the thread of the tire valve and air leakage pre- vented when the tire is being inflated By turning the eccen- tric lathe of this at- tachment with your finger you will lock your hood so securely that it will not rattle. The tension spring is adjustable Desiring to give to his automo- bile a distinctive appearance, one owner of a sporting model cut the side windshields and ven- tilators of his car as shown here What Inventors Are Doing to Improve Engine-Driven Road Vehicles of All Kinds This apparatus indicates the volt- age of your storage battery on | charge or discharge and the state of efficiency of any plate in the a || battery What is believed to be the smallest high- power automobile ever built is shown in the foreground of this picture. It has shown a speed of fifty-eight miles an hour, is a won- derful hill-climber, and is equipped with a two-speed transmission and a six and a half-gallon gas-tank In this self-cleaning and self-cooling spark-plug a monel-metal ball, kept a in constant motion by r) the vibration of the en- es gine, prevents excessive carbon deposits Dust-laden air drawn into the engine will soon wear out all mov- ing parts. The appara- tus shown here removesthe dust 70 APE from the air on to a wet sponge a x toh Le # This machine wi!l enable the operator If you wish to keep the springs of to inspect an automobile tire in a few your automobile well oiled, always moments. A powerful electric light place an old piece of felt soaked in discloses any picked-up nails or small oil between the springs and the breaks or cuts in the tire guiding seat on top of the springs 79

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This small automobile is not a toy for children but a racer capable of traveling at one hundred miles an hour The Seven-Foot Automobile ee HE ‘Flying Peanut” is the nickname given to what is said to be the smallest practicable automobile. feet long over all, it is hardly a foot and a half longer than Yet it is so well proportioned that it would be difficult to distinguish it in a picture from a full- fledged racing-car were it not for the comparison in size of It is owned by Robert Breese, of Long Island, who is seen driving it in the accompanying the average man is tall. the car and its driver. illustration. In its design the miniature machine follows up-to-date racing-car engineering, except that like the early racers, the power of the engine is transmitted to the rear wheels by chains at the side instead of by a shaft. Otherwise the radiator, engine- hood, springs, wheels, tires, and body are built in proportion. The wheels are small and give the car a low center of weight so that it is able to make sharp turns at a high speed. The engine is a modified airplane model, said to be able to propel the car at one hundred miles an hour. Because of the clever proportioning of its parts, the baby racer is most pleasing to the eye. The driver’s seat is comfertable, and his eyes are pro- tected by a miniature hinged wind- shield. How Your Carburetors Waste Millions URING a series of tests under- D taken for the purpose of ascer- taining the volume of carbon monoxide discharged from the exhaust of run- ning-trucks and pleasure automobiles under average working conditions, Dr. A. C. Fieldner, supervising chemist of the United States Bureau of Mines Experiment Station at Pittsburgh, found that 30 per cent of the gaso- line now used by automobiles in the United States is wasted through improper adjustment of the carburet- ors, causing incomplete combustion. Estimating the average price of gaso- line at 34 centsa gallon, American auto- mobilists waste annually more than $231,200,000 for gasoline.

TEERING \ COLUMN Seven ~.-->-- burgh, Pennsylvania, solved the problem by an auto: regulator of the current strength or intensity. The regulator consists of a rheostat mounted cylindrical casing directly beneath the steering-wheel. [t< contact switch may be moved from one notch to ano: her by the driver’s little finger without removing his hand from the steering-wheel. degrees of intensity between the standing light and the maximum penetrating driving-beam. The installation of this regulator does not interfere \ ith the lighting system of the average car. polished reflectors are used with the lights so tilted that no part of the projected beam extends above the level of the

The rheostat switch that graduates your lights from the steering-wheel Popular Science Moi‘) Regulating the Headlight Glare HILE most engineers have attacked the proble eliminating automobile headlight glare by the uve of some form of diffusing lens, Mr. A. A. Tirrill, of Pit 0} tts- tie nha The apparatus affords eight Clear lenses and lamps. The cover of the casing housing the rheostat is provided with a flexible stop, which is adjustable so that it can be set at the highest no- glare position allowed by various local authorities. The flexible stop may also be lifted, permitting the rheostat contact handle to be moved down to the standing dim position. A New Fuel-Feed System for Automobiles ESIGNED to overcome the tem- LD peramental non-functioning peri- ods of the vacuum systems fitted on most automobiles, the new system here shown uses the compression in the engine cylinders to feed the gasoline from the tank to the carburetor. Whereas in the vacuum system the least fuel is supplied when the engine requires the most, the new system supplies the most fuel under the same conditions. Because of its positive action, the new system does not per- mit of a condition of ex- hausted gasoline supply when climbing steep hills as long as there is gaso- line in the main tank. The fuel feeder con- sists of a small cylin- drical tank placed under the engine-hood as shown in the picture. It can be mounted on any make or type of car, truck, tractor, airplane, or sta- tionary engine. There are no complicated valve mechanisms to get out of order. When the engine turns over, the compression in the engine cylinder to 80 FROM FUEL TANK

system TO CARBURETOR The harder the engine works the more fuel it requires and the more will be supplied to it by this new feeding which the feeder is attached is con- ducted through the piping at the left to a control valve inside the feeder- tank. It then passes down into a cylinder directly below the valve, forcing down a piston in that cylinder. This expels the air below the piston through a spring-controlled valve in the bottom of the cylinder. As the piston in the engine PRESSURE FROM avele , r¢ SER travels downward, the pressure on top of the piston in the feeder cyl- inder is relieved, and the spring beneath it forces it upward, causing a suction below the piston which draws fuel from the storage-tank through the pipe at the right and top into the lower por- tion of the feeder-cylin- der. As the engine pis- ton again rises and puts pressure on top of the feeder-cylinder piston, the gasoline below it is forced into the feeder- tank, from which it flows into the carburetor by gravity. The piston in the pump continues to operate until the float rises and automatically closes the control valve.

February, 19 Openi Batter: HE pu { ishior used 10 Oper storage batt money, an repairman a one cel nee be opened tank metho the new bat accompany time or fo opened mec and at muc. In smalle a waste of f all day, it m in that th into steam seals may b of the two for use in repair work combinatio on an ordir

With this of a stor NE hoist same type in two di one. Th adding to the hoist, distribute and make: the body The hoi make of ten tons ¢ ton hoist ° extension and is ope all the o chanically from the The fir is by me lifting ay under sid near the are raise wound a the rear

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y m id Febr: Ivy, 1921 Opening Automobile Batteries Mechanically }:E putty-knife and the old- cashioned hot-water tank, when ysed 10 open the cells of an automobile storage battery, are expensive in time, money, and labor to the battery repairman and his customer. If only one cc!l needs to be opened, all have to be opened when the old hot-water- tank method is employed. But with the new battery steamer shown in the accompanying picture, one cell at a time or four cells together may be opened mechanically in much less time and at much less expense. In smaller shops, where it would be a waste of fuel to keep the steamer hot all day, it may be put to a dual purpose jn that the water ordinarily turned into steam for softening the battery seals may be passed through the upper of the two tanks shown and distilled for use in the battery after the cell- repair work has been completed. This combination steamer and still is heated on an ordinary gas-stove. N\SifAM 10 STILL-TANK With this new steamer one or four cells of a storage battery can be opened An industrial tractor that can push as well as pull load-carrying vehicles around plants, its pulling capacity being fifteen tons This Gasoline Tractor Pulls or Pushes BILITY to push as well as y pull, and to run twenty- four hours a day if necessary, distinguishes this new industrial tractor from other forms. The machine will tow or push standard trucks or load-carry- ing vehicles or skids about plants, and do the work more quickly and cheaply than it can be done by manual power. It is a compact four-wheeled solid rubber-tired vehicle with a power plant, clutch, gearset, and rear axle such as are used in small-capacity motor-trucks. Perhaps the most unusual feature of the vehicle’s appearance is the two flat steel bumper plates front and rear to permit pushing from eitherend. The It has the apparatus of a small motor-truck. Notice the front and rear bumper plates machine’s 22.5-horsepower gasoline en- gine will drive it at speeds up to fifteen miles an hour, and permit it to pull trailing loads of fifteen tons A New Double-Lift Hoist for Motor-Truck Bodies NE of the newest mechanical hoists differs from others of the same type in that the body is lifted in two distinct operations instead of one. This method, while After the latter has been raised for one third of its height, the bottoms of the two lift arms come level with the top of the truck frame and leave the wire cables. The second lifting operation begins at this point, when two pivoted side arms, with rollers at their lower extremities, adding to the parts forming the hoist, serves better to distribute the lifting strains and makes it possible to raise the body to a greater angle. The hoist is made to fit any make of truck from one to ten tons capacity. The one- ton hoist with a special frame extension is for Ford trucks and is operated by hand, while all the other sizes are me- chanically operated by power from the regular engine. The first lifting operation is by means of two vertical lifting arms bolted to the under side of the truck body near the front. These arms are raised by two wire cables wound around two drums at the rear end of the body. 81 By lifting the truck body in two distinct operations this new mechanical hoist secures a greater dumping angle take the load on rails along the tops of the body silis and force the body up to its full height. When lifted to its highest point, the body is held until lowered by an automatic power cut-out, which disengages the driving clutches working the two cable drums. The body can be stopped at any desired point between the lowest and highest points by a clutch and hand-brake lever.

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ATER is not an ex- plosive in the usual sense of the term. Any gas or liquid will explode if it is cramped into a small space under high pressure. Com- pressed-air tanks often ex- plode when the pressure reaches a high point. Water is made to “explode” by placing it under a pressure of several thousand pouncs to the square inch. There has always been a need of a way to tear apart stone masses without using blasting-powder and dyna- mite. ‘‘Why not use water under high pressure?’”’ some one asked. The idea was put to test and found practical. This method can be used for razing buildings, quarrying, coal-mining, potash-mining, tunneling, etc. No noise is produced and there is abso- lutely no danger of accident or fire. The hazard of having large quantities of high ex- plosives on hand disappears. The ‘‘exploding’”’ machine is really a small but powerful pump that is used in con- junction with a compressed- air drill. A hole is drilled to Water taxing the place of dynamite in razing a brick foundation with a battery of small hydraulic pumps The ‘“exploding”’ machine is a pow- erful pump used in conjunction with a compress- ed-air drill. The pump, operated by hand, forces the water into cylinders, bring- ing a tremendous pressure to bear and resulting in an explosion like that of dynamite Popular Science Monthly Where Water Takes the Place of Dynamite accommodate the expand. ing member of the ex. ploding device. This part of the machine consists of a steel housing provided with a number of cylinders and pistons. Water is forced into these cylinders witha small hand-operated water. pump. After the water. pump is operated for a few minutes the pistons exert a tremendous pressure up- ward and downward. The material in which the de vice is inserted is fractured; finally it gives way to the pressure. One man is ab'e to exert a terrific pres- sure with this simple device. A pressure of many tons per square inch can be brought to bear if the small water-pump is_ oper- ated long enough. A battery of these ma- chines will make short work of a brick build- ing if it is to be torn down. One illustra- tion shows men at work ‘forcing’ down a heavy brick wall. A New Collarless Harness for the Horse HAT is claimed to be the most revolutionary step in the ad- vancement of horse haulage, since the first horse was harnessed to a wagon centuries ago, is a collarless harness tried out on the veldts of South Africa and now being introduced in the United States. The harness is the in- vention of J. C. E. Kohler, a rancher of the Orange Free State, in South Africa, and is revolutionary in that it brings into play an en- widest part of the horse’s girth instead of from the neck. It is the claim of the inventor that the use of the neck muscles and those of the fore legs for pulling in- terferes with the locomotion of the horse itself; and he points out that pulling from a heavy collar results in an irritated neck The new harness is lighter than the conventional design; it is also cheaper. It may be employed for a one-horse wagon or for a double team by the addition of two extra shaft straps for a one-horse rig. For a double set, the only change necessary is a slight short- ening of the center shaft-pole. The strap around the horse’s greatest girth from which the pulling is done is con- nected with a pad between the two front legs at the top and held bya light strap around the neck where the collar is otherwise placed. tirely new group of muscles never before used by a horse in drawing a loaded wagon, the pull being made from the The new harness fits tightly around the hind legs at the rumps and thus makes back- ing up much easier. A rancher of South Africa claims that the horse has been harness- ed inefficiently ever since the first member of the species was sub sidized by man This rancher, J. C. E. Kohler, has invented a new kind of harness, which brings into play the correct muscles for drawing a load, the pull being made from the widest part of the horse’s girth instead of from the neck 82 The new harness is collarless, and the horse is spared painful sores that the collar often causes. It is also lighter and cheaper When I phragm stylus 1 thread “ ” E T toyoun before le very Wi Steiger, recordin is used f rubber. opera tl one sma the rep more 9 rubber 1 The treated pared c tive to It is no’ does it 1 it is bo’ The | pulleys There a the thr HE an | by J. ¢ York, of norm that it wall wk The | bearing under t the a toom. bed-clo be rem the spri left on anism simple Voives

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nd. eX- art if a ith ind 2 to reg- iple e of lare t to nall per- ma- hort Lild- corn tra- at own Februaty, 1921 A Talking Machine that Uses a Thread for Records When he speaks into the horn, a dia- phragm at the other end vibrates and a stylus makes impressions on a moving thread END me your ‘Aida’ thread.” This request may sound strange to you now, but it is quite possible that before long you may be saying those very words yourself. For Mr. E. Steiger, a Swiss, has invented a sound- recording instrument in which thread is used for the records, instead of hard rubber. Imagine a thousand yards of opera thread! It would perhaps fill one small spool; yet when played on the reproducer would deliver much more music than the largest hard- rubber record made today. The thread is ordinary thread treated with a coat of a specially pre- pared composition that is very sensi- tive to sound when it becomes hard. It is not affected by temperature, nor does it require any special care. Thus it is both inexpensive and durable. The blank thread is stretched over pulleys in the recording machine. There are two main pulleys that hold the thread directly underneath the Push the HE new drawer bed is By P. Schwarzbach Photographs © American Photo Service Here is a less complicated thread record- ing-machine for children. After the speaking or listening apparatus is attached, the thread is set in motion recording stylus, and there are aux- iliary pulleys that help keep it taut. When a record is being made, the thread is moved forward at a uniform speed while the record-maker sings, talks, or plays into a horn. Thereisa diaphragm at the other end of the horn and a stylus attached to it. Each sound-wave is recorded on the thread by this stylus. One picture shows a man dictating in one of these machines. He holds the horn in one hand and a handle in the other. He turns this handle slowly and evenly as he speaks into the horn, and it sends the thread on its way Bed into He’s listening to the tale of a thread. Since the thread is very cheap and much more durable than the usual hard-rubber records, we may soon expect to find it in all fields of talking machinery by further pulley action. It is so small that you can carry it on busi- ness trips. After dictating a number of letters, you cut off the used thread and send it in an envelope to the office, where it is run through a machine which has a receiving set attached to it. The operator listening to the spoken words transcribes them on a typewriter. There is still another important use for the thread machine—in the home. Suppose some member of the family is far away. The Jetters that you send each other are practically the only means of communication you have. Would it not be more comforting to hear each other’s voice? A few yards of talking thread would make it pos- sible. Most of the machines are operated by hand. There are some machines, however, in which this is done me- chanically, insuring an absolutely uni- form movement of the thread. the Wall and Forget It slight shove causes the bed an invention introduced y J. G. Stickley, of New York. A comfortable bed of normal size is so arranged that it disappears into the wall when not in use. The bed operates on ball bearings on a track built under the dressing-table in the adjoining dressing- room. In the morning the bed-clothes may or may not be removed, as desired, but the springs and mattress are left on the bed. The mech- anism is unlocked by a simple operation that in- volves no lifting; then a to slide easily through the wall into its place under the dressing-table. The foot- board of the bed becomes the finished base of a book- case that is built into the wall. ' The footboard fits exactly under the bookcase and makes a complete piece of furniture, giving no ink- ling that it is part of a bed. Now step into the small dressing-room and see what has become of the bed. Open the doors under the In the present-day apartment-house a bed that takes up no more room than the paper on the wall is a boon indeed 83 dressing-table. There it is, mattress and springs, with the spread and pillows.

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COPPER GASKET os & To prevent leaks in boiler-tubes. The tube end has a square shoulder that rests tightly against the plate, with a copper gasket pressed between Leaky Boiler-Tubes Will Weaken the Locomotive LOCOMOTIVE can be no more efficient than its boiler-tubes. When they are leaky the locomotive loses its power rapidly, and it must either be repaired at considerable ex- pense and loss of time, or run.with low efficiency. When a locomotive stands idle in the repair-shop, the railroad it works for is minus just that much of its equipment and -whatever it is capable of earning in hauling freight or passengers. Until recently, preventing boiler- tubes from leaking has been a vexing problem. A thousand and one differ- ent methods have been proposed and tried without satisfactory results. It is only recently that a practical, leak- proof joint has been devised. This new method of inserting tubes in boilers, which is the invention of Charles S. Coleman, of Los Angeles, California, is illustrated herewith. The tube end has a square shoulder that rests tightly against the plate, with a copper gasket pressed between. A slight bevel is given to the hole into which the tube end fits, and this “wedge effect’? also helps to prevent leakage when the locomotive is in service. The boiler-tube proper is shrunk on the tube end and the joint fused. This method is a great improvement over the old expansion method, which was really only half a remedy. A tube forced into place by the old ex- pansion method is shown. The new method of holding boiler- tubes in place has been found ninety per cent efficient and results in a saving of from ten to twenty per cent of the fuel consumption. This also means from ten to twenty per cent more mileage obtained from each tender- load of coal. Thesaving of fuel results from maintaining the boiler pressure at normal. Popular Science Monthy An Automatic Chemist NE more machine to replace human labor! This time the services of an analytical chemist are dispensed with. Philip E, Edelman, an electrical engineer of New York city, has devised an apparatus that will stand watch over a chemical process and act more efficiently than a well- trained chemist. In large chemical plants it is the duty of a routine chemist to watch cer- tain processes. He must do this through analysis. At certain periods of the day or night he takes samples of the ‘““‘mix”’ to determine whether or not the proper quantity of the various ingredients is present. In paper-mills, the sulphurous acid used in the bisulphite process must be held to a free sulphur- dioxide content of two per cent. It is the duty of the chemist to see that this per- centage is held. The auto- matic chemist will automat- ically regulate theingredients. How does it work? Every chemical mixture has a cer- tain electrical resistance, or, we might say, it has a certain degree of electrical conduc- tivity. This degree of con- ductivity depends entirely upon the percentages of the various chemicals present. Some mixtures have high conductivity, while others offer great resistance to the passage of an electrical cur- rent. Since slight changes in mixture vary the electrical conductivity, an especially designed electrical controller is made to follow closely such che nges automatically and to keep the ingredients of the liquor at certain values. This is done throurh an automatic valve, electrically oper. ated. Any change in the acid content will change the resistance of the solution or liquor. A relay closes a motor circuit, which operates an elec- tric motor connected with a valve, The valve opens and allows acid ito flow in. When the conductivity of the solu- tion is brought back to normal throuyh the addition of acid, the valve is auto- matically closed. Such an apparatus as this of Philip E. Edelman will do much to overcome errors of judgment by the chemists. This arrangement of apparatus will per- form all the duties of a routine chemist It Thaws Out “Empties” FLAME NOZZLE ‘ , Thawing out a frozen ‘‘empty” with a huge gasoline blow-torch, thereby saving time and money S4 HEN empty coal-ecars are re- turned to the mines in the winter- time, the hoppers on the bottoms are often frozen up. In stubborn cases, several men must work half a day or more to pick the ice away. One man can do the trick in a few minutes if he is provided with this large gasoline torch. A separate tank contains the fuel, which is fed to the burner through arubber hose. The burner is mounted at the end of a Jong pipe that also serves as a handle. A valve at the end of the pipe allows the workman to adjust the flame. When a frozen “empty” is received at the mine, the workman directs the big, hot flame of this torch against the parts giving trouble. Things start to crack and sizzle and in a few moments the mechanism is loosened up and the car is again ready for business over the shining steel tracks. Februcrifs | H!RE deal ouija-boar' orters Cc which are triangular munication the skepti that if the ingly man’ least does Sunker scientist, | of ouija-b jieves it V absolutely question scious Op tion. It operator t board, W “spirit ty structed « when the ated upol fitted wit with an ir in comme The opers is writing then the | progress | hiding-pl: The tri than a pi casters O boards ar being the tion. Th cireumfe! tween ea key. T letters a LEC reac opment 1 is growil rails on € tems are only wi plates, b weld th curity a deteric eliminate the rai loose. Here welder ticular t develop1 parts ha It is nm

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Rebrucrys LIT Is the Ouija-Board Controlled Subconsciously? This Hindu scientist’s invention may tell H!RE has always been a great deal of controversy about the ouiia-board. Its most zealous sup- porters contend that the messages which are spelled out by the little triangular table are in reality com- munications from the dead, while the skeptics have held all along that if the operator does not know- ingly manipulate the board, he at Jeast does so subconsciously. Sunker Abaji Bisey, a Hindu scientist, has invented a new sort of ouija-board by which he be- lieves it will be possible to settle absolutely aud without doubt the question of conscious or subcon- scious operation and manipula- tion. It is not possible for an operator to contro] the Bisey ouija- board, which he has called the “spirit typewriter.” It is con- structed of steel, and writes only when the triangular table is oper- ated upon a steel tray, which is fitted with blind keys connected with an invisible ribbon, such as is incommon use on all typewriters. The operator does not see what he is writing until he has finished, and then the paper which has recorded the progress of the table is taken from its hiding-place and he sees the message. The triangular table is nothing more than a piece of steel fitted with three casters or rollers, as ordinary ouija- boards are, the tray on which it moves being the mechanical part of the inven- tion. This tray is fitted all around its circumference with a series of pegs, be- tween each two of which is a typewriter key. The keys correspond to the letters and numerals found on an By Herbert Asbury . Sunker Abaji Bisey operating his ‘‘spirit typewriter,” fitted with blind keys con- nected with an invisible ribbon ordinary ouija-board. As the trian- gular table under the hand of the operator travels about the steel tray under whatever influence it is that actuates a ouija-board, one or another of its three angles, instead of touching the letters, as is done on the wooden and visible board, pokes its point between the pegs and strikes a key. Each key is connected by a lever to a letter or numeral beneath the tray, and a touch between the pegs impresses that key or numeral upon a type- writer ribbon, which is also hidden. At the end of the sitting there is with- drawn from the machine a paper on which is noted every letter or numeral! struck by the triangular table. The ribbon moves one space after each printing of a letter. The tray upon which the ouija moves is round, and all of the pegs and posts upon its surface are per- fectly plain faced and exactly similar to one another in appear- ance. Set an operator before the beard, turn it about several times, and it can easily be seen that the board cannot be knowingly man- ipulated. The following description of the invention as furnished by Mr. Bisey to the Patent Office may more clearly explain the mechanism in connection with the drawing: “A circular tray is mounted on a suitable frame, and its surround- ing edge is divided into thirty-six equal parts by pegs. The space left between the pegs is occupied by the button of the key lever. There are thirty-six such keys---one for each letter of the alphabet and ten numerals. The operating board is made triangular and any of its corners is designed to enter the gaps between the pegs. A circular board is pivoted on the triangular board and serves as a hand rest. A paper ribbon and ink ribbon are mounted on rollers and placed underneath the tray. No letters or signs appear on the key buttons to prepare the mind of the operator, who can operate the apparatus placed before him in any position.” Mr. Bisey’s invention is an ingenious version of the overworked ouija. Traffic Does Not Wait on This Track-Welder LECTRIC welding has reached a point of devel- opment where its application is growing daily. All of the rails on electrical railway sys- tems are held together not only with bolts and _ fish plates, but with a permanent weld that is an added se- curity against accident and deterioration. The weld eliminates the possibility of the rail joints becoming loose. Here is a new electrical welder in use. This _ par- ticular type is a very recent development, al] superfluous t wheels so that it may be rolled along the track and easily moved from place to place. The dynamotor takes the current from the system when it is connected to the rail and trolley wire. It con- verts this current into one suitable for welding pur- poses. A man is shown hooking one wire over the trolley with a long pole. The man at the left of the picture is adjusting a carbon mold to a rail joint in prepar- ation for the welder, who is parts having been eliminated. It is mounted upon three When a street-car comes along, the men roll the small dynamotor off the track and allow it to pass. This requires but a few minutes ~ 85 seen working at the right of the picture.

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Testing a Road The testing wheels run in tracks beside the road slabs. One pair of wheels having a spring attachment weighs nine thousand pounds; the other unsprung wheels weigh three thousand pounds. When dropped on the road below, they have the same effect as a seven- ar eight-ton truck ANG! You drive over a hole in the road, get shaken up, break a spring on your car, and say things about state roads. The road materials are usually at fault; they should have been thoroughly tested before they were put down. That’s what the government is doing to-day—testing forty-nine different kinds of road composition by heavy- weight methods. The various mix- tures are made up into slabs seven feet square, of different thicknesses. All sorts of concrete mixtures, differ- ent kinds of bricks on concrete bases, sand and cement—all are given their chance to prove their merit. The slabs are laid end to end, and over them an impact machine is drawn by cable. The machine traveis in tracks at the sides of the slabs, and carries in its arms two pairs of heavy wheels, one pair having a_ spring attachment and solid rubber tires. The wheels are dropped on the various slabs, and they have the same effect on the road material as the rear wheels of a seven-and-a-half-ton truck. The unsprung wheels—those having no springs to help absorb shock—weigh three thousand pounds and the sprung ones nine thousand pounds. By watching the surface of the various slabs after the weights have been dropped on them several times, it is easy to determine which mixtures will stand up best under traffic conditions. There is another test that is used— the pile-driver test. But in this case there is no pile for the weights to fall on; they fall directly on the slab. The lower weight, weighing one ton, is long, thin, and has no spring to absorb the shock when it drops. There is, however, a hard rubber shoe at the bottom. On top it carries a full-sized truck spring which receives a second heavier weight that is dropped from above This three-ton weight is cushioned just as a load on a truck is cushioned. Both weights are raised by a cam that is operated by a gasoline engine. As the cam turns over, it drops the load, and the combined weights have the same effect on the Before It Road materials are now given heavy- weight tests by the government. Here are forty-nine sections of different road compositions. Heavy wheels. are dropped on each section and their com- parative resistances determined road as the rear wheels of a truck passing over an obstacle. The weights can be dropped from different elevations up to a maximum of four inches. When dropped three and a half inches, the impact pressure equals sixty thousand pounds. ean also be varied a aL. The amount of weight to be dropped In this way it is simple matter to duplicate virtually the shocks on an average road The pictures on this page show the Popular Science Monthly Is Built The road materials also receive a pile- driving test. The pile-driver has a one- ton weight with a rubber shoe at the bottom and a truck spring attached to thetop. A second weight, of three tons, is also used in the test two methods of road-testing described here. The pile-driving tester was photographed’ when the three-ton weight was being raised. You can clearly see the rope and pulley used for the purpose. The slabs that it pounds are placed close together, but they do not touch each other. They may be seen at the right in the photo- graph showing the heavy wheel tester in action. To Prevent Heat Waste in Furnaces OU pay so dearly for coal these days that none of the heat it gives off should be wasted. Watch the tem- When wishing to find the temperature of gas in the flues, he turns a switch and is answered in five seconds 86 perature in the smokestack closely and you will be able to tell whether your furnace is delivering your money’s worth in heat. But how ean you watch this temperature? By means of a pyrometer—a kind of thermometer that records high temperatures. The sensitive element of a pyrometer consists of a thermocouple, which is made up of two wires of dissimilar metals that are attached to a delicate current-recorder. When the couple is heated, a current will be produced and the pointer on the recorder will register the amount, which increases with the temperature. : To find the temperature in the smokestack, place the couple in the stack. The current generated is trans- lated into degrees of temperature and is constantly recorded on a scale situated in a near-by room or in a dis- tant superintendant’s office. The mes- sage of the furnace is electrically con- ducted. Ii the temperature is too high, something is wrong with the system. In connection with the temperature scale, there continuous recorder very much like a recording barometer. is a uary; ‘HE ¢ 7 has that an re) erly -efini pai! { she from the upinas thorough amateur, tions and steps to twelve or job woul dollars if It is owner to viding h quiet pl automob because certain : this perl It is no ° automoh where it to day, t garage oO days. failure is owner e¢ material careful, A gre: bile pain proper r oil is use pentine, should a and smc cheaper of colors smear reé right m one sho materia A lis Metal p known Roug in cans pound : It is to a thick then re: Some Othe lead, di ing, tur linseed automo of varn and ret be had It wi brushes 3 in, or put on lead ex quality apply » expens will be essenti

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February, 1921 Learn How to Refinish Your Automobile ‘HE public in general Save has the impression that an old automobile cannot be prop- erly refinished outside of an automobile paint shop. Nothing can be farther from: the truth if this work is taken up in a systematic, workmanlike, and thorough manner. Itispossiblethat the amateur, provided with proper instruc- tions and a working knowledge of the steps to be taken, can paint his car for twelve or fifteen dollars when the same job would cost him fifty or seventy-five dollars if done in a commercial garage. It is possible for the automobile owner to finish his car this winter, pro- viding he has some spare time and a quiet place to work. Painting an automobile takes considerable time, because each coat applied requires a certain amount of time to dry, and this perhaps is inconvenient to some. It is no worse, however, to have your automobile laid up in your own garage where it can be worked on from day sixty dollars by doing it yourself smooth, even coats. A large, thick brush is the best for putting on the varnish. It is necessary to put the varnish on as rapidly as possible, and for this reason a large, first-quality brush will be the best. All brushes work better after having been used for a time and if new brushes are pur- chased, they may be broken in by saturation with oil and using them briskly on a board for fifteen or twenty minutes. As they are used they be- come more pliable. A good way to keep the bristles from bending and be- coming deformed is to bore a small hole in the base of the handle at a suit- able height and after preparing a small can of linseed oil, run a wire through the hole, resting it upon the edge of the can, thus supporting it in a per- pendicular position. For the rubbing material, sandpaper, emery-cloth, or steel wool have their Carefully go over the entire automobile, look- ing for checks, cracks, portions of the body where the paint has chipped off, and then decide whether or not it will be necessary to remove the old paint. Providing the body is reason- ably free from these blemishes, a lot of time and work may be saved by leaving the original color on. If there are but few spots where the paint has chipped off, or only an occasional erack or check, it will hardly be wise to remove the paint. Should there be many of these defects, however, the only safe and sane method will be to take off the paint. Assuming that the automobile is in a condition to warrant a complete job of finishing, secure a liquid paint and varnish remover, or a gasoline blow- torch. The liquid remover comes in cans and is accompanied by thorough and accurate directions for use. This liquid thoroughly softens the old paint to day, than it is to haveitin a public advantages and disadvantages. Steel in a short time so that it may be d garage or pajntshop for a week or ten scraped off easily with a putty-knife a days. The main factor resulting in _S_ sor other dull-bladed instrument. The n failure is carelessness. The automobile y | entire surface is then washed with tur- n owner equipped with the proper tools, | pentine, removing the last vestige of d materials, and some spare time, if he is the old surface. careful, need not fear the outcome. - A great many attempts at automo- How to Use the Blow-Torch 0 bile painting fail because of the lack of ¥ proper materials. For instance, when If the blow-torch is to be used, hold >» oil is used as a thinner in place of tur- it in your left hand, and with a putty- " pentine, the coat does not harden as it knife in your right, go to work. Hold should and does not stand the rubbing the flame 3 or 4 in. from the surface and smoothing processes. Also, when and go slowly back and forth over a cheaper house colors are used in place small area until the paint is thoroughly of colors ground in turpentine, a greasy blistered. Follow immediately with smear results which does not dry in the the knife, scraping off the scales as fast 4 right manner. At the outset, then, as they are loosened. When one small “ one should determine to use the best : ere patch has been treated, select another, . materials available. —_ the old paint has been removed, and repeat operations. The blow- g : : e ll all dents and cracks with putty : . bs A list of the materials required: torch method is not as satisfactory as Of Metal primer, obtained from any well- wool or emery will perhaps be the most known varnish manufacturer. the other, for on almost every occa- effective and but a small quantity will sion now and then a spot will not come i Rough stuff: this is usually procured berequired. The grade should be fine off with the application of the heat, ie in cans at twenty-five or thirty centsa or very fine. Pumice-stone is pre- and is, instead, burned on to the ig pound and is a sort of a heavy paste. ferred by some, but is more expensive metal. It is then necessary to use a It is to be thinned with turpentine to and the steel wool and emery-cloth sandpaper or varnish remover. ‘e a thick working consistency and is_ will serve nicely. After the automobile has been freed of ne then ready to be brushed on. Aside from the tools mentioned all paint and cleaned with the kerosene- d above, a few vessels, a chamois-skin, a turpentine solution, carefully go over m Some of the Materials Required large brush, and some cotton rags will all sheet metal and take note of any also be required. dents, cracks, or depressions which Other materials required are white It should be understood at the out- may be there. These are then filled r lead, dry white lead, dry bolted whit- set that the automobile must be free in with solder or putty and smoothed % ing, turpentine, coach japan, and raw’ from dust and drafts when it is being off with emery-cloth. Solder is better linseed oil. After the painting of the ‘d automobile is finished, a good quality of varnish is required to cover the body painted. The first thing will be to thoroughly wash the automobile. This may be than putty, for it is permanent and stands more hard use than putty, but putty is more easily applied. ¥ and retain its gloss. Directions may done outside, and plenty of water After the body has been thoroughly of be had from any paint manufacturer. should be at hand. Go over the body cleaned, it should be gone over with a a It will be well to have four or five and chassis and soften all chunks of medium grade of sandpaper. This h brushes on hand. A large flat brush mud and hardened dust. After the process roughens the surface of the ™ 3 in. or so in width will be required to dust has been removed, mix some metal slightly, and enables the first a put on the rough stuff, primer, and kerosene and turpentine together in coat, or primer to adhere firmly. Too lead coats. A 2-in. brush of better quality should also be on hand to apply the color coats. A little extra expense in procuring a good brush will be well worth while. For it is essential to have the color laid on in equal proportions and with this solu- tion thoroughly soak all oil and grease spots that were immune to _ the water. This solution loosens any re- maining spots and they can then be rubbed off. great emphasis cannot be laid upon this first coat. Any grease or foreign matter between the metal and the first coat will eventually result in a chipped-off place. (To be continued) 87

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Popular Science Monthly Repairing a Cast-Iron Roll Under Difficulties N every mechanic’s life emergencies will arise that call for rapid think- ing and original work on his part in order to keep the wheels of industry running smoothly. In this article the writer tells how he made an emergency repair on a broken roll that lasted until the roll was worn out. When a bar was going into No. 2 pass, a sliver on it jerked the tongs from the hands of the roller and it was jammed between the side of the bar and collar, separating grooves 2 and 3; the result being that an 8-in.-long section of collar was broken out. Owing to conditions, welding supplies were unobtainable; a new casting could not be had in less than three weeks, four days more being required for turning a new roll. The writer was delegated to make a mechanical repair if it were possible to make it withstand the side pressure exerted by the iron during rolling. A patch the size of the broken section and screwed to roll was first thought of, but rejected as impracticable as, both joints being near one another, the patch would spring and shear the bar. It was decided to cut the cast-iron collar off the roll altogether and re- Brain Saves NE day the boss took me up to the attic floor of an old-fashioned office-building to do some work on the skylight. This upper floor had origi- nally not been intended for use and was only partly finished, the wooden roof trusses showing in all their nakedness. The main roof of the building was flat, but out of it projected, one at each end, two square towers about 50 ft. high, and the skylights were at the tops of these towers. The top of each skylight was pro- vided with a metal ventilator, and it developed that one of my fellow work- men, some days before, had been em- ployed to fit the bottoms of the ven- tilators with hinged doors that could be closed by means of a cord from the floor below. Only a single cord was used and it was supposed that the doors would open of their own weight. As a matter of fact, it took so much cord to reach the floor, that the weight of it nearly balanced the door which, in consequence, would only open an inch or two. My job was to fasten lead weights on the doors to make them overbalance the cords. With the height of the upper story added to that of the tower, the ven- tilators were all of 70 ft. from the floor, and as I looked up the inside of the tower I inquired of the boss, ‘‘How’s a fellow going to get up there?” “I don’t know,”’ was the reply, as he turned to leave. “Smith got up there By W. S. Standiford

How a broken cast-iron roll was re- placed with one of wrought iron place it with a wrought-iron one, the joints of the halves being a long dis- tance apart. To enable it to with- stand side pressure, a slot having a slight taper and 215 in. deep was cut into roll, the width being 214 in. After the slot was turned, a hardwood templet was made. The length of the two halves was ascertained by the “cut-and-try” method until, when placed in the roll grooves opposite one another; they made a snug fit at the joints and bottom. From these tem- plets a wrought-iron collar was forged and turned with a taper matching the slot; the tapered section being a fow thousandths of an inch larger so as to make a forced fit in the slot. Half of the wrought collar was forced in the slot as far as it would go by using hammers, a heavy iron ring was then put over the half collar, and 4 jacks, one opposite each joint, and others spaced equal distances apart. Part of the ring in front of the jacks was filled with iron blocks. The jacks were then screwed up, care being taken to get equal pressure until the collar touched the slot bottom. The collar was drilled and tapped to take *;-in. screws that extended 1 in. into the roll body. The other half of the col- lar was next fitted, a good job result- ing. The roll was put into the lathe and the collar turned to the same size as the others. When tried in the mill, the new collar stood the heavy pressure admirably, a slight mark on the iron bars produced by the joints being removed in the finishing pass of the rolls. Brawn when Fixing the Ventilator By Edward H. Crussell

There are more ways than one to fix the ventilator in a skylight all right; you ought to be able to do what he could.” Well, when a fellow came to notice the pieces of 2 in. by 4 in., spiked here and there up the sides of the tower, it wasn’t hard to guess how Smith had climbed it. He had evidently taken a ladder, climbed to the top of it, spiked on a piece of 2 in. by 4 in., carried upa piece of plank, stretched it across the tower, then carried up another ladder, stood it on top of the plank and so on until he had reached the top. I had no doubt of my ability to climb the inside of the tower in the way Smith had, but I had no intention of lugging half a dozen planks and ladders 88 up to the top of a four-story building unless it was absolutely necessary. Permanent ladders on the outsides of the towers made the tops of them (which were flat, and surrounded with an ornamental iron railing) easy of access and my first thought was, that I could go up the outside of the tower, take a couple of lights of glass out of the skylight, stretch a_ plank across and work from it. When I got to the top of the tower, however, I found that by taking out four screws I could lift the ventilator off the sky- light and get at the top surface of the door quite easily. So I went below again, pulled each door shut, fastened the cords securely, carried up my weights, fastened them in place, and replaced the ventilators, screwing them down securely. How to Bore a Conical Hole through Wood HEN you have a conical hole to bore, such as for a handle hole in a wooden maul or other similar place, leave the cutter of an expansive auger bit a trifle loose and begin boring at the side where the smaller end of the hole is wanted. The inner edge of the cutter lip being angular, the cutter will gradually draw itself out from the body of the bit, making the hole larger as the bit goes into the wood. February, REE! of French S and othe used for furs, like cony, et tage to s skins of A bris skins of buyers < good p) thought their qu known; being i New Y¢ factures mole, : ijmitatio tises fo rabbit-s for ther skins if The } bit sho animal be kille ears, al a sharp shown skinnir 'F h the motor yond 1 by rec they \ is plac and t the st it | servel more wheel drivil in th of ch comp with whee whee the r all bk near are som road hoot ind het bee: side roa gen Lolv

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- Ss © OD DMD 1 rh February, 1921 Save Your REEDERS of rabbits, especially of Flemish Giants, Belgians, French Silver, Beveren, New Zealand, and other breeds of which the skins are used for making high priced imitation furs, like French seal, mole, beaver, cony, ete., will find it to their advan- tage to save and properly prepare the skins of their rabbits. A brisk trade has arisen in rabbit- skins of the breeds mentioned. Fur buyers all over the country now pay good prices for skins which were thought worthless a few years ago, as their quality and fur value were little known; most of the rabbit-fur skins being imported from Europe. One New York manufacturer who manu- factures rabbit-skins into near-seal, mole, and beaver-cony, and other imitations of high-priced furs, adver- tises for 10,000,000 American raised rabbit-skins, and will pay good prices forthem. It pays to save your rabbit- skins if you are raising fur rabbits. The illustration shows how the rab- bit should be hung in order to skin the animal properly. The rabbit should be killed by a sharp blow behind the ears, and the jugular vein opened with a sharp knife. Hang the animal up as shown in the illustration, and begin skinning by cutting around the hind By Marcellus W. Meek legs at the first joint, and slitting the skin down to the tail inside the hind legs, shown by the dotted lines. Skin around the vent. The skin is then easily pulled off ‘‘cased’’—inside out like a glove. When the forelegs are The proper way of hanging the rabbit and some devices for stretching skins reached, a little deft work with the skinning-knife will remove the skin nicely. Cut around the neck, as it is not necessary to skin the head. When removed, the skin must be stretched and dried. Fur dealers prefer ‘‘cased’’ skins. Fur stretchers are easily made as shown in the drawing, either from thin boards or wire. The wire stretcher which has a loop in the top is very easily made from 3¢-in.-gage wire, and is inexpensive. Rabbit-skins must be dried in a cool, dry place never in the sun or where it is damp. Move the Automobile Tires Forward By Robert A. Chandler F he will change tires around in the manner described below, a motorist can make them last far be- yond the usual mileage. This is done by reducing the strain on the tires as they wear away so that the newest tire is placed at the point of greatest strain and the oldest one at the point where the strain is least. It is evident, even to a casual ob- server, that the rear tires wear out more rapidly than those of the front wheels. This is due to the strain of driving through the rear wheels, letting in the clutch, applying the brakes, use of chains, skidding, and so on. Now comparing the right side of the car with the left, the tires on the right wheels will wear faster. The left wheels run along the smooth part of the road where the ridges and ruts are all beaten down by the traffic. But near the edge the road is rough, there are more ruts and small stones, and sometimes these wheels must leave the road altogether. There is more likeli- hood of meeting broken glass, metal, and other objects on this side. Then there is more weight on these wheels because the car is tipped more to that side on account of the crown of the road. Therefore it may be stated as a general principle that the rear tires AT NNT DL {)\\\ RET ) Changing the tires according to the sys- tem here explained will mean a saving 4 wear more than the front ones and the right ones more than the left. Starting with all new tires it will be evident that the right rear tire will show serious wear long before the left front tire has got over its newness. At this point the two should be exchanged. It is difficult to state just when this change should take place, possibly it is best left to the discretion of the driver. If a ‘“‘non-skid”’ is used, the change should be made before the tread is worn so smooth as to lose its protective feature. At the same time the other 89 Rabbit-Skins—They Are Valuable Free circulation of air is necessary. After the rabbit-skins are dried, they should be sorted as to size and quality, and each lot tied up separately. Burlap or grain sacks are the best for shipping skins. A card should be placed inside the bundle with name and address of the shipper, and the outer tag should give the name of the house to which shipment is made, as well as the name and address of the sender. Be sure to write plainly in ink. The sacks should be sewed up instead of just tied. Don’t use sacks full of holes, and don’t use wires to tie up the skins, as these might cut the pelts. It is best to ship by express or parcel post. Although winter skins are preferable, many buyers will take summer rabbit- skins, as the rabbit often has prime fur in summer and fall as well as winter. Rabbit-skins are graded into ‘‘prime’’ and “unprime’”’ skins—the unprime skins showing black spots or splashes on the back where the new hair is com- ing in. Both grades are sorted in four sizes—very large, large, medium, and small. The least valuable grades are used for felt hats, and are termed “‘hatters’ fur;’’ these are bought by the pound. The better grades are bought by the piece. as They Wear two tires should be exchanged to keep matters even. After a few thousand miles more we enter the second phase. One by one the tires will wear out and not even vulcanizing can save them. They must then be moved up in the sequence shown. Supposing the left front tire is discarded, the right front tire takes its place; the left rear tire moves forward and the right rear tire takes its place. The spare tire is placed on the right rear wheel, the point of greatest strain. Of course if some tire is to be re- moved temporarily for repairs, it will be replaced by the spare tire instead of moving the rest forward, and as soon as returned it is put b ack in its regular position. By following the above system you will not only make your tires last longer, but you will have less trouble from punctures—an other good reason for following this practice. The logic of the advice given by the author is unimpeachable and is based upon a careful study of the subject. Tests, extending over a period of sev- eral years, have proved beyond reason- able doubt that the rotation method suggested will actually result in a con- siderable saving of time, labor, and money to the owner of the car.

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Don’t Let the Tow-Car Get You ON’T condemn a_= spark-plug unless it is at fault. To deter- mine this, first find out which cylinder is missing explosions. Short-circuit each spark-plug with a screwdriver. If the engine slows down, it is a live plug. If it doesn’t, that cylinder is not firing. Disconnect the wire from the spark- plug and run the engine. If a good spark jumps from the terminal when laid upon the cylinder head, the trouble is in the plug or in the cylinder. If there is no spark, the trouble is in some other part of the ignition system. If a good live spark is shown, remove the plug and lay it upon its side on the cylinder head with its terminal at- tached. If it shows no spark, the trouble is in that plug. Clean off the carbon with a cloth dipped in kerosene or use a brush. Touch up the points of the plug with emery-cloth, but do not scrape the emery on the porcelain, as_ that scratches it and makes it soot up all the more readily. A cracked core must be replaced. Put the parts together and adjust the gap to approximately the thick- ness of a very thin dime. Try it again in the cylinder. If the engine misfires, the trouble may be a loss of com- pression or faulty carburetion. Be sure to carry an extra set of lamp- bulbs, so that one can be replaced as soon as it burns out. You should know the candlepower of the bulbs in your headlights, side lights, tail light, instrument light, and dome light. Take them out now and make a memorandum in the box with the bulbs, and so insure your lighting future. How long is it since you went over the connections of the steering mech- anism to see that they were fastened securely? This should be done at least once a week, as more damage can be done by failure of the steering mechanism than by any other cause. See that lock-nuts, lock-washers, and split-pins are doing their duty. Try each nut with a wrench even when it is secured by the means mentioned. There is more wear on the side walls of the right tire, due to the increasing use of the left-side drive. Some drivers have learned to drive up close to the curb without touching it. A It is learning to repair the little troubles that keeps your car from being towed little practice on your part will go a long way in making your tires last their guaranteed mileage. Now is a good time to go over the rim to see that the various parts have not rusted together. Give them a fresh coat of paint before replacing them. If this is not done, the rains will rust them together so that a de- mountable rim will become a perma- nent fixture on the wheel. The skilled driver rarely uses his brakes except for an emergency stop, or when going downhill. Learn to judge the distance and let your car coast to the point at which you wish to stop. This will save the brake linings and other parts, so that they will not have to be replaced so often. The funnel used to fill the oil reservoir should have a strainer in it of very fine wire. It keeps out dirt and foreign matter which would otherwise fall into the system and clog up some small opening. One little piece of dirt might do no harm, but others would accumulate there and finally cause clogging. This matter of straining the oil is especially necessary with the type of lubricator using several small pumps, as a small piece of dirt getting into any one of the valves puts that pump out of commission immediately. Some relief valves have handles set the wrong way, so that the valves shake open. If one becomes trouble- some, replace it with another which is set properly. If this is not desired, the hole may be plugged with a piece of brass rod and a new hole drilled at right angles to the old one. One of the many mistakes which be- ginners frequently commit is to rest the feet on the clutch and brake pedals. It wears out the clutch collar and makes it noisy, and this habit may also cause the brake to drag. The best position is to have the feet near the pedals ready for instant use, but not onthem. Sometimes the water does not circulate properly through the water jacket on the carburetor. Run the engine and see if it warms up. If not, disconnect the lower pipe and see if the water runs through the jacket. Locate the stoppage and remove it. Remember that gasoline cannot evaporate unless heat is pro- vided either by the water jacket or the hot-air inlet to the carburetor. 90 Popular Science Monti To Develop Strength in the Wrist and Fingers HE little device shown in illustration is called a grip n chine because it is intended to devel: 5 the strength of the wrist and finge It is used by squeezing the moval « crosspiece until it reaches the oth.; crosspiece. This operation practis: ( with both hands each day for fifte: or twenty minutes, will strength: your grip and enable you to do gyn- nastic stunts with greater ease. The use of this simple exerciser equally beneficial in restoring the strength of the hand after it has be- come weakened through injury. First get a piece of straight heavy, wire 1g in. thick and 2314 in. long. Sharpen each end with a grindstone or file. The handles or grips are made from wooden pail handles 334 in. long. Mark the wire with a scrape of the file 934 in. from each end. Slip the pail- handle on and fasten it between the marks by forcing slugs of wood into the hole, then bend the wire at each mark. Take a piece of wood about 6 in. long and 1 in. square. Drive the ends of the wire into the wood about 1 in. from each end as shown in the illus- tration. Take another piece of wire of th: same thickness 6 in. long. Mark it 11 in. from each end. Slip on the 4 yv VIEAVY WIRE a \ | | WOODEN | PAIL HANDLES || | DETAIL OF GUIDC —SCREW CYC Persistent and regular exercising with this device will give greater strength to your grip in a short time pail-handle and fasten it between the marks as you did the first. Bend the ends as shown and make two guards of a piece of thin wire to keep the crosspiece from pulling away from the long wire. The guards should be large enough to allow free movement of the crosspiece and should be oiled to prevent wear. Screw two screw-eyes into the wood as shown and fasten 2 large springs— one from each side of the crosspiece— to each screw-eye. The wire can be obtained in a tinsmith’s shop and the springs will be found in a hardware store.—WALTER THOMPSON. Th Ju: ator ! the | the | and | Tt teeth four Whe prod ings Tool erat) steel unti worl

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February, 1921 Through a 4-in.W rought “erie Steel Pipe in 110 er, ee Se cond S = Clamps and Filing Guides RR Bevels \ SS Hack Saw Frames

>

~ ‘

Just before this photograph was taken, the oper- eyAQ\ Mitre Rods : WY Re-Saws ator released the ratchet controlling the speed, and Knives — Circulad- Me @ork, Cloth, the saw actually slashed its way clear through Leather, Paper, etc. the four-inch wrought steel pipe in one minute i * Repairing Saws and fifty seconds. Mitre-box Saws . : y : ’ Cylinder Saws é This circular, metal-cutting saw, with special Drag Saw Blades teeth inserted close together and each series of ——- a. four to six interlocked, is a Disston invention. Trowels-Brick, Plastering, Pointing, etc. ‘ Wherever used, it greatly reduces the cost of Knives~Cane,CornHedge a r Webs, Turning and Felloe producing steel of irregular shapes such as cast- Venecring Saws ings or railroad tracks. Screw-slotting Saws c.. Ice Saws *.. @®_ | Hedge Shears

The fundamental quality of all Disston Saws and

‘ ° : Files and Rasps Tools lies in the Disston-Made Steel. For gen- Ws 75 Back Saws erations the workmen have produced the finest Saw-sets . : : . : Plumbs and Levels steel suitable for each article in the Disston list, se, Rig ee Marking, etc until these men know steel as few men in the Band Saws for Wood and Metal world can know it. Grooving Saws Knives — Machine “ATED U7 . ~ NO Cross-cut Saws. and Tools | | HENRY DISSTON & SONS, INC. Buck Saws | Philadelphia, U. S. A. Compass Saws K ‘| Ll Mandrels at ee | Hand, Panel, and Rip Saws Inserted Tooth Circular Saws Milling Saws for Metal Shingle Saws Levels ~ Carpenters’ and Masons’ [<\—_] Screw Drivers Saw Gummers Stave Saws s Plumbers’ Saws Butcher Saws and Blades One-man Cross-cut Saws Saw Screws Tool Steel Sugar Beet Knives Squares-Try and Mitre Slate Saws - Circular Hack Saw Blades Keyhole Saws Segment Saws Kitchen Saws Circular Saws for Wood, Metal and Slate

SAWS TOOLS FILES

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Popular Science Monthly All Sorts and Conditions of. Steel ITH the advent of the automo- bile came the wide use of alloy steels and of the term “alloy steel’’ in the nomenclature of the machine trades. And as the automobile has become a necessity, people who never knew and never cared about things mechanical have become interested to the extent that a great deal of general information that was heretofore trade talk is today part of the man-in-the- street’s vocabulary. The automobile is largely respon- sible for the general use of alloy steel and for its use in other lines requir- ing high duty, but the elements that produce these advanced results were known many years before and such steels were produced and used in lim- ited quantities. Also there are other steels that the machinist encounters at times and that are of much gen- eral interest, but that have not re- ceived the advertising that has marked automobile materials. The Chemistry of Steel The chemistry of steel is of the utmost importance today. Without going into that, it may be said that changes of 1/10 of 1 pér cent in the amount of certain elements will make a considerable difference in the work- ing of a piece of steel and the service to which it is adapted. A number of the striking changes in properties and the use to which such steel is particu- larly suited will be mentioned. First, one or two facts should be fixed in mind. We have mild, or ma- chine, steel, which is the most valu- able structural material we know; roughly, it is a combination of iron and carbon, but with not enough car- bon in it to make it a hardening steel. Then we have carbon steel, containing 0.60 per cent or more of carbon—steel that will harden, showing in the hard- ened state greater strength and the ability to cut other metals. If it were not that the hardness is always accom- panied by brittleness, carbon steel would answer for most of the purposes where alloy steel is now used, both in construction and as a cutting steel. The increase in strength—and in brit- tleness—is in direct proportion to the amount of carbon added. A carbon content of 1.20 per cent is rarely ex- ceeded in straight carbon steels. Manganese Steel Manganese steel is the oldest of the so-called ‘“‘alloy steels.’”’ About fifty years ago, Hadfield’s manganese steel was brought out for cutting-tools and marked a wonderful advance in the art, for it would stand up under far greater speeds than carbon steel. It hardens in air and from that quality it early acquired the name of “self By Donald A. Hampson hardening.”’ Until the advent of high- speed steel, self hardening occupied the foremost place for cutting-tools and is still in demand for many classes of work. In its composition there is 12 per cent of manganese and about one per cent of carbon. Every one knows that the plunging of a piece of red-hot steel into water causes it to harden, if the steel is of the proper grade. It is the element of carbon that brings about this change. Unless the brittleness is reduced by tempering or there have been other elements introduced to prevent this extreme hardness, the picce of hard- ened steel is almost as brittle as glass and can be shattered by a blow from a hammer. One notable exception to this is found in steel alloyed with man- ganese—not the composition noted above for cutting-tools, but a compo- sition for structural purposes, the most notable example of which is the use in safe and vault building. The manganese steel of this grade is heated and plunged quickly, just as is carbon steel, and while it becomes very hard, it does not get brittle as does the latter, but is ductile and will resist almost any amount of hammering without fracture. After hardening, it cannot be cut with tools—all surfaces that re- quire machining have to be ground. Still other compositions of manga- nese steel are highly valuable for mod- ern uses. The non-shrinking die steel, so prized by our tool-makers, contains about 1.60 per cent of manganese along with 0.90 per cent of carbon. When it is considered that ordinary tool steel will change its size several thousandths of an inch when plunged hot into water, the value of a steel that does not change at all is at once apparent, particularly in the case of an expensive die, one whose shape precludes any correction after it is hardened. The addition of from 5 per cent to 14 per cent of manganese to steel renders it non-magnetic and a poor conductor of electricity, features that make it desirable in the construc- tion of many kinds of electrical appa- ratus. Tungsten Steel High-speed steel, the undefeated rival of Hadfield’s manganese, contains 18 per cent of tungsten and about 0.65 per cent of carbon (enough carbon to make it harden). It is the possessor of the wonderful property of remain- ing hard at all temperatures up to and including a dull red heat. This is very important in modern machine- shop practice where such a cutting speed must be maintained that heats the chips to a temperature of 600° or over and where the tool gets even hot- ter and must run so for hours. In point of actual hardness, carbon steel exceeds high-speed steel, but the 92 former loses its “temper” at a little over 400° and so must be used at vastly reduced speeds. High-speed steel, oncé hardened, is practically self hardening, for nothing short of long hours of treatment will change its na- ture to where it can be machined again. This steel is not used for anything ex- cept cutting-tools. During the early days of the war, its price rose to nearly four dollars a pound and still remains well over half that amount. Tungsten steel of a lower grade is used extensively in electrical and in- strument work. It has the property of retaining its magnetism for long periods, once charged. This makes it ideal for permanent magnets as well as in the more delicate work of compass- needles. Silicon: Steel Another steel prominent in elec- trical work is silicon steel. It finds its use in electromagnets up to the largest sizes; it has a greater perme- ability than the purest of wrought iron, and a high resistance. An in- teresting difference will be noted in the last two paragraphs—tungsten steel for permanent magnets, silicon steel for electromagnets. Nickel Steel Nickel steel is one of the most valu- able of the alloys. It came into promi- nence twenty-five years ago when nickel-steel bicycle tubes were made for use in the Coiumbia bicycle—a steel with 5 per cent of nickel that gave greater strength with much less weight. Today nickel steel is widely used in marine work for engine and ship forg- ings, having practically displaced all other steels. Armor-plate is made of nickel or chromium steel or steel with these two elements combined in vari- ous proportions. Armor-plate with a composition of 314 per cent nickel, 11% per cent chromium, and 0.25 per cent carbon can be pierced by a pro- jectile which, if powerful enough, will go through, leaving a clean hole (as if by a punch) with no cracks radiating from the hole. Other properties of nickel steel are its resistance to wear. Nickel steel rails last nearly four times as long as ordinary rails, and thus railroad offi- cials specify them for the hardest ser- vice on curves. Nickel steel has a high tensile strength and a high per- meability. Twenty-five per cent of nickel renders the steel noa-magnetic, though this is seldom required (note that 5 per cent to 14 per cent of man- ganese does the same thing). A com- position of steel with 30 per cent of nickel is practically non-corrosive; such steel is used extensively for boiler- tubes where its consequent long life Februar |

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Febr uary, 1921 Bets Iry Sthat Trail, Kate” “ [’: a steep grade, but we can make it. You won’t be scared, will you P’’ ‘Of course I won’t, silly. I’d g0 anywhere with you, Jim—and a Harley-Davidson! And just think—with all the rough roads and hills we’ve been over this afternoon, we haven’t used up sixty cents’ worth of gasoline!” “That’s just like a woman—figuring out pennies! But you’re right, Kate. There’s no ‘high cost of motorcycling.’ ”’ Ask your dealer for a demonstration Harley-Davidson Motor Co., Milwaukee, Wis. World’s Largest Producers of Motorcycles “CTOorlds Champion” —— I

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i “HANES” is the national standard in underwear! It will make good to you! Read Hanes Guarantee: “‘We guarantee Hanes Underwear absolute- ly—every thread, stitch and button. We guarantee 1o return your money or give you a new garment if any seam breaks.” **T* XTRA wear, extra warmth and extra comfort are built into “Hanes” winter un- derwear for men just as ac- curate time is built into a good watch! “Hanes” is made with one ideal in mind—that it be the greatest underwear value ever sold at the price! Your own test will prove that it is—and it will also prove why our guarantee on every “Hanes” garment is so broad. We know what goes into “Hanes’”—and what “Hanes” must deliver to you in satis- faction! You can feel that thrill of contentment the mo- ment you put on “Hanes” underwear! “Hanes” never disappoints! *¢t TANES” heavy winter weight union suits and the new silk trimmed, full combed yarn medium weight union suits (carrying the yellow Hanes label) have the non-gaping tailored collarette and elastic knit, shape holding arm and leg cuffs; buttonholes last the life of the gar- ment; an extra gusset assures extra comfort across the thighs; the “Hanes” closed crotch stays closed; pearl buttons sewed on to stay; reinforcements strengthen every strain point. “Hanes” heavy winter weight Shirts have the snug-setting elastic knit collarette and arm cuffs. Drawers have an extra wide, durable 3-button sateen waist band that assures comfort and service. Union, Suits for boys are unmatchable! “Hanes” Union Suits for boys are unequalled at the price for fleecy warmth, form fitting comfort and wear-service. They are wonderful value because they give such extraordinary service! Made in sizes 20 to 34, covering ages from 2 to 16 years. 2 to 4 year old sizes have drop seat. Four desirable colors. See “Hanes” underwear at your dealer’s. If he cannot supply you, write us at once. P. H. HANES KNITTING CO., Winston-Salem, N. C. “ye bork p.mece Warning to the trade: Any garment offered as “Hanes” is a substitute unless it bears the ‘‘Hanes”’ label. Now Sumumer-oull want ko wear ldanes Nacaseok Vuisn Suits! i Popular Science Month; makes it the cheapest material in t} end in spite of its high first cos Other applications where there is e posure to water and vapor show t! same freedom from constant renewa! . Chromium Steel Chromium steel with a high pe centage of chromium resists oxidati: and corrosion well. But it isin armo:- plate that this alloy steel really shin. at the present time. The great har: - ness in the face of the plate and th» great toughness at the back are s- cured by chromium as in no other wa). From 2 per cent to 4 per cent o/ chromium allows the lowering of the carbon content without affecting the hardening of the steel and then the undesirable quality of brittleness is not present to an alarming extent. This brief review of special stee!s will show the degree to which the stee!- maker’s art affects those things upon which our modern life depends. And that without touching the alloy stee| as applied to automobile crankshafts and gears, or the steel that goes into the great bridges and from that down to the common implements of farm- ing. These latter uses of mild steel steel that before the war brought around three cents a pound—have been promoted and made possible at a low cost because alloy steels have been found ready for cutting-tools and for highly stressed parts. The mouse- trap sold over the counter of five-and- ten-cent stores was made salable at that price because high-speed steel tools were used in its manufacture and the bridge over which speeds the twen- tieth-century train is made safe by the use of alloy-steel pins at critical points —steel that is scientifically com- pounded and treated. For Binding Hose Clamps with Wire O bind hose with tight wired con- nections a tool can readily be made from an old pair of pliers, even a pair with the ends broken. Saw or grind the ends flush and dri’! with two !,-in. holes as shown in th: HOSE ‘wikE ‘USED TO CLIP WIRE —— 94 This useful tool may be made from an old pair of pliers sketch. A U-shaped piece of wire | cut and the ends are placed throug! | the holes after surrounding the hose. Twisting the handles makes a clamp that is both tight and inexpensive. | Wire up to }¢-in. in diameter can be | used with this tool and wired patches about pipes, tanks, etc., can be made securely.—G. A. LUERS. Februa An A fo! OR k ove fixture positive illustra nary he the la screwet the la short with t screw A sect cular | a piec hole s drillec causes brack AC A’ Be quite heade such . ism, | hand! Ple whee the 1 whee end. Tl forat book with time

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February, 1921 An Adjustable Light Fixture for the Drafting-Table OR use above the drawing-table or over the desk an adjustable light fixture that is simple in construction, positive in the setting, is shown in the illustration. This consists of an ordi- nary half-round reflector secured about the lamp socket. The socket is screwed to a piece of brass tubing and Here is one way to get good light, just where it is needed the lamp wire led through this. A short section of pipe split lengthwise with two cuts for the tubing and a set screw is for purposes of adjustment. A second section of tubing, with a cir- cular bend in the extreme end, rests in a piece of angle-iron through which a ; hole slightly larger than the tube is drilled. The overhang of the lamp | causes the tube to hold firmly in the 1 bracket.—G. A. LUERS. 3 A Clock-Wheel Serves as a. , Paper-Perforator PAPER-PERFORATOR is easily made from an old clock-wheel. Bevel the wheel on both sides until quite sharp. Now get a %4-in. brass- headed screw, two small brass washers . ism, and a piece of wood to form the a handle. Place a washer on each side of the wheel, insert the screw, and attach to rlANOLE TOOTHED WHEEL? A scREw- “WASHER An old clock-wheel and a wooden handle make a good paper-perforator sn the wooden handle so that the toothed e. wheel protrudes beyond the handle 1p end. e. This tool, drawn along a page, per- be es de forates the paper quite easily, and note- books with fast leaves may be provided with detachable pages in a very short time.—GEORGE H. HOLDEN. such as are used in clockwork mechan- |: | | SAFETY Satisfied Users Have Sold More Than 2,000,000 in 13 Years No selling arguments—no advertis- ing—just the personal recommenda- tions of men who use it and like it so well that they have induced their friends to use it also. The Enders is so simple — only three parts—apart in one second, to- gether in three; so safe; so absolutely sanitary, and so satisfying. The constantly increasing millions of Enders blades sold each year reg- ister this continuous satisfaction. Could I offer you a more reasonable argument for trying the Enders—if, genpers sEiis for any reason, your morning shave FOR $1.00 is not wholly satisfying P Ha es Shaving with an Enders Safety Pushed ie 9 Sead Razor is ‘‘Just like wiping your face ok eee with a towel.’ package of 5—35c. FOR SALE BY BEST DEALERS EVERYWHERE ENperRS SALES CoMPANY 17 Battery Place New York La ae —— B: cad, ~~ pee { rR TRADE MARK = ». PAT. MAY 21906 95

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Learn Shorthand LESSON, 5 MINUTES Absolutely astounding —the quickness, cer- tainty and ease with which you can learn K. I. Shorthand. Exactly what the busy or ambitious person needs. Trifling cost. Try the Specimen Lesson Here: re's\\p and,this isOa Write the two together, and you have NO pe Here's ( th ly write and with these two ersy To meke path you sim- + movements of your pencil, you have e 9 word thet needs 16 pencil movements: when writteh in longhano, Nere's \ t so it is cosy to rite 1 at, A tap end \p pnt. Already you heve lcorned four KT. horthand signs you won't forget. With the other signs and easy di- rections you can leern to ipidicete every word in the dictionary in querter to twentieth of the time Tre- uired in ordinsry writing, as ra pe ly as wo spoken! LEARN QUICKL if | o1 learn the above in minutes you should learn the whole k. I. Shorthand within 5 hours, after which you develop speed with ordinary prac- tice Hindrances of old systems eliminated; no shading, no disjoined vowel ymbo's, no ruled lines, no positions—you can read ur notes readily months or years after. Hence kK. I. Snorthand is valuable for “aking no'es in pri 23s enten, Seema 8, et k. I. Shorthand Pe Brochure In order to prove to you the simplicity of K. L. Shorth and, we would like to send you FREE the new brochure, guaran- tee, and further informa- tion about this system. SHORTHAND is furnished under guaran- tee. Fill out or copy the coupon below and mail to 1 am taking it downin us promptly. You will be K. 1. SHORTHAND.” surprised and delighted. KING INSTITUTE EL-188 Station F, New York, N. Y. or 8 So. Wabash Ave., EL-188, Chicago Please send Free Brochure EL-188 of K. I. Shorthand Name Address “*Talkas fast as you like, POATES’ COMPLETE ATLAS of the WORLD The 1920 edition of this Atlas just pubhshed shows all the changes to date. It is the world re-mapped according to the Treaties of Peace following the World War. It is accurate, concise and reliable. It has 195 pages six colors. and Each map is 8% x 1034 and occupies two pages, so that the book is 7x 10 inches, a convenient handling. An index of countries and towns, with locations, is a valuable feature. of maps in five S1Z¢ for Cloth, Price, postpaid, de = Flexible Morocco, Price, postpaid, POPULAR SCIENCE MONTHLY 225 WEST THIRTY-NINTH ST., NEW YORK $2.65 4.65 How Tool Steel May Be Case-Hardened T is necessary for toolmakers to case-harden many tools and tool ends, such as wrenches of the S shape and straight-end styles, in order to pre- vent serious wear. There are many other tools which would last longer without becoming misshapen were they case-hardened after being dressed up and before use. The following method of case-hardening good grades of steel may be employed. First, secure or make a little wrought-iron box, the size depending on the Jength of the tools or pieces of steel to be hardened. This box of thin iron may be shaped like a cigar-box and have a hinged lid or otherwise, just so that it may be sealed air-tight with fire-clay or such matter between the lid and box. When such a box is prepared, secure enough bone-dust to nearly fill this box. Next, cover Case-harden your tools. will last much longer They the bottom of the box with said bone- dust about an inch deep and place the tools or steel parts in this bed— being sure that no parts come in contact with each other or the sides of box. If more than one layer of steel parts is to be hardened, place another layer of bone-dust over the first layer of steel parts and then another layer of steel parts, then more bone-dust, until the box is packed tightly. Seal with fire-clay or other such substance, or pack lid of box with asbestos to se- cure an airtight box under heat. Then you are ready to give the box and con- tents the required heat and cooling treatment to produce case-hardening. When all is ready for the fire, heat box and contents to a cherry-red heat and maintain this heat until you are sure the pieces of steel inside are thor- oughly heated, which may require 15 to 20 hours, after which remove box and contents and quickly cool too! ends or the whole in a pail of luke- warm water. A pinch of salt will help. If this fails in results, repack and heat for a longer period, as the carbon from the bone-dust must pene- trate the steel to give it hardness. 96 Popular Science Monthly Making a Useful Hacksaw for the Pocket GOOD way of utilizing broken hacksaw blades is to make a holder, or haft, similar to a pocket- knife. Take a 4-in. length of 14-in.-diam- eter brass gaspipe, cut down on on side lengthways, and then flatten with hammer until a turn cap U shape is formed, just of sufficient width to re- HACK SAW ao —— BLADES — 4” tip y YM fee / , S U gk NUT AND BOLT * — HAF T This shows how to make a folding hacksaw from broken blades ceive two thicknesses of the saw- blades. Half an inch from both ends bore a 1¢-in. hole, insert the eyelet end of a piece of the saw in haft, together with a clockmaker’s small washer, and tighten up with small bolt and nut or a set screw. The saw-blades, when not in use, will then fold over and fit in the haft like a penknife, and may be carried about in one’s waistcoat pocket with ease.—GEORGE H. HOLDEN. To Reverse the Polarity of a Compass OMETIMES a small compass be- comes reversed through careless- ness in using it near a strong magnet. As it is almost useless in this condi- tion, it must be restored to its original polarity, but how to do this without removing it is usually a puzzle. The compass, held level so that the needle is free to move, is brought to the pole of the magnet, which it will naturally seek. It is then brought around in a semicircle, allowing the REVERSED A COMPASS o. MOVE FORWARD QUICKLY - The polarity of a compass may easily be corrected, as described here needle to revolve as shown. This brings it over the pole. The compass is now moved forward quickly so as to catch the other point of the needle before it can get away. As this is the correct polarity, the compass is tapped a few times against the magnet to set- tle the molecules into place and the trick is done.—ROBERT A. CHANDLER. ¢ | February, 1 ——— ———— ena ss} th fo do pr co sei an ar m m tv $:

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Febru ry, 1921 - \ THY, that’s my third increase in a year! training will do for a man. couldn’t do anything in particular. “Then one day I woke up. do any one thing well. “Why, in a few months | had a whole new vision of my work and its possibilities. see, I was just beginning to really understand it. and he was immensely pleased. and wished he had more like me. “Just after that an opening came and he gave me my chance—at an increase of $25 a Six months later I was put in charge of my depart- month. Then I really began to grow. ment and my salary went up again. Since then I’ve had two increases of $50 a month and now I’ve got another $50 raise!”’ For 29 years the International Correspondence Schools have been helping men and women everywhere to win promotion, to earn more money, to have happy, pros- perous homes, to know the joy of getting ahead in busi- ness and in life. More than two million have taken the up road with I. C. S. help. More than 130,000 are now turning their spare time to profit. Hundreds are starting every day. Isn’t it about time for you to find out what the I. C. S. can do for you? Here is all we ask—the chance to prove it—without obligation on your part or a penny of cost. That’s fair, isn’t it? Then mark and mail this coupon. ‘Another $FJO Raise!” | It just shows what special | When I left school to go to work I | All I could hope for was just a job- that’s what I got, at $60 a month for routine, unskilled work. for three years, with one small increase each year. I found I wasn’t getting ahead simply because I couldn’t | I decided right then to put in an hour after supper each night preparing myself for more important work. So I wrote to Scranton and arranged for a course that would give me special training for our business. I made some suggestions to the manager Said he had noticed how much better I was doing lately and I stayed at it | You | | \ Seem eanneetiaemeeiliaaannantiaaeaeed AR OUT HERE sm cee cee eee et INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7611 B, SCRANTON, PA. Explain, without obligating me, how I can qualify for the posi- tion, or in the subject, before which I mark X. ELECTRICAL ENGINEER SALESMANSHIP | EjElectric Lighting and Railways ADVERTISING Electric Wiring Window Trimmer | Telegraph Engineer Show Card Writer Telephone Work Sign Painter | MEOHANIOAL ENGINEER Railroad Trainmao Mechanical Draftsman ILLUSTRATING | Machine Shop Practice Cartooning Toolmaker ‘BUSINESS MANAGEMERN? Gas Engine Operating __| Private Secretary { OLVIL ENGINEER | BOOKKEEPER Surveying and Mapping Stenographer and Typist 1 MINE FOREMAN OR ENGINEER Cert. Public Accountant STATIONARY ENGINEER TRAFFIC MANAGER | ©/Marine Engineer Railway Accountant Ship Draftsman Commercial Law | ARCHITECT GOOD ENGLISH Contractor and Builder Teacher Architectural Draftsman Common Shot Subjects | Concrete Builder CIVIL SERV Structural Engineer Railway Mail. Clerk PLUMBING AND HEATING AUTOMORILE OPERATING | Sheet Metal Worker Auto Repairing Textile Overseer or Supt. Navigation Spanish | (CHEMIST [) AGRICULTURE 9) Freneh Mathematics C) Poultry Raising §() Italian Name | Present Occupation | Street and No [l= State —— Canadians may send this > 7-25-19 International Corresp ontreal, Canada

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Mother Pins Her Faith to Musterole In days gone by, mother mixed a mustard plaster when father had bronchitis or brother had the croup, but nowshe uses Musterole. It is better than a mustard plaster. She just rubs it on the congested spot. Instantly a peculiar penetrating heat begins its work of healing —and without fuss, or muss or blister. Musterole relieves without dis- comfort. The clean white ointment sets your skin a-tingle. First, you feel a glowing warmth, then a pleas- ant lasting coolness, but way down underneath the coolness, old Nature is using that peculiar heat to disperse congestion and send the pain away. Made of oil of mustard and a few home simples, Musterole is uncommonly effective in treat- ment of the family’s little ills. It takes the ache out of grandfather’s back. It soothes sister’s headache. It helps mother’s neuralgia. Mother pins her faith toit asa real ‘‘first aid.” She is never without a jar of Musterole in the house. Many doctors and nurses recommend it. 35c and 65c jars; hospital size $3.00. The Musterole Co., Cleveland, Ohio BETTER THAN A MUSTARD PLASTER

AN EASY WAY TO MAKE MONEY 22: : plod along on a small salary, Be independent. Go in the tire re pairing business. One man says “‘I made $60.00 the first day.’’ Others average $200 to $500 a month. Very little capital needed. Jobs plentiful. Every motorist a pos- sible customer, No experience needed. We teach you. SHALER Tire Repair Outfit Improved Wrapped Tread Method cd Used by Tire Manufacturers Does as good wor’ as the big high priced vulcanizing outfits. A boy ean use it. It’s the only vulcanizer that has Automatic Heat Control, and can’t undercure or overcure a tire, Requires no watching or regulating. * FREE Book **How to Open a Tire Repair Shop.”” It tells how to make big money. Don't delay. Write quick. C. A. SHALER CO. 2101 Fourth St. Waupun, Wisconsin a re $4 or $5 wiley is A Standard, Guaranteed =) TYPEWRITER With Every Modern Writing Convenience

Write Today For Ilusirated Circular Explaining Try-Before-You-Buy Plan SMITH TYPEWRITER SALES Co. (Harry A. Smith) 306 —218 No, Wells St.,Chicago, ll, a month

Make a Pocket-Bib for Your Baby HE pocket in the bib described here catches the crumbs and food particles which the baby drops from mouth and fingers, and prevents them from falling on the clothing or floor. The bib is made, like a majority of

This pocket bib will help to keep baby’s clothes and the floor clean baby bibs, preferably of rubberized or other waterproof fabric. To make the pocket, lay the bib on a sheet of paper—about one third the distance from the bottom to the neck, as shown in Fig. 1. Draw the bottom outline of bib on the paper. Around this draw another line, distant from the first line, 34 in. at the bottom, flaring to 1 in. distant at the top edge of paper. At the points A, B, and C, mark V-shaped notches as shown, so that the projecting pieces left shall be the same length at their outer edges as along the inner line. Using this as a pattern, cut out your pocket, allowing enough margin Outsidethe : POCKET - jinesforaseam, 4 "eee and the same BIB - — alon g the V G2 Sie 5 cuts. Seam the — edges of the V cuts together. Place edge of pocket against back edge of bib and stitch flat, as shown at Fig. 2D. Turn, bring- ing pocket in front of bib, and stitch through, as close to edge as possible, making a turned edge as shown in section at Fig. 2C. Bind top of pocket with tape. The bib complete is shown in per- spective in Fig. 3. The mother may add some individual, artistic touches to her work, but, remembering the purpose for which it is intended, she should avoid everything that would make it difficult or impossible to clean the bib after use.— CHARLES A. PEASE. 98

Follow this pattern for making one of these use- ful bibs

£ Popular Science Monthj A Flexible Fastener for Small Belts N such places as printing-shop. and other places of business wher: veyors are used, the need of a «mall flexible fastener for connecting the ends of small belts together arises. The writer was recently confronted with the task of equipping a y ‘On- {ten eat : ; arge blueprinting machine with new elastic bands. The old ones had lost their elasticity, the main quality required of them in the rolling of the printed shee after it had been developed and dried. Wire was first used, but the ends <oon frayed and pulled apart. A more sub- stantial method, which has worked per. fectly for some time, was empleyed in the following manner: Pairs of tin strips, the width of the elastic belt and 3 widths long, were cut from sheet tin and small holes punched near their edges, as shown in Fig. 1, on a line running through their centers, These holes were punched through with a nail set and ground smooth. » Small wires were then cut into short lengths and put through the holes and the ends clenched over, holding the two strips firmly together, also shown in Fig. 1. The ends of the strips were spread with a knife-blade wide enough to FE wom ee eo Lore

BELT:

WO STRIPS HELD i= “4 } BY WIRE — a FIG! FIG.2 Fig. 4 Every step in the making of this flexible belt-fastener is here clearly illustrated

grasp with the fingers (see Fig. 2) and the bend was completed as in Fig. 3. It will be noticed when this has been done, that a simple hinge has been made, which is held together by the doubled wire. This is now ready to attach to the belt ends, with the exception of punch- ing the tooth-like prongs that dig into the belt, when fastened, and prevent it from pulling out. To make these prongs, procure a small nail, and grind the end to a three-cornered point. This should consist of two broad surfaces and one narrow one. Then finish by grinding off the point until the end of the nail appears as shown in Fig. 5. This, when driven through a sheet of tin, makes a mark similar to the one shown in /'ig. 4. By making a row of these marxs with the prongs along each edge of the connectors, as shown in Fig. 3, the ends of belting or webbing will not pull out when it has been clamped down with a pair of pliers. When using the punch, place a thin strip of wood

Feb pet’ een 1 ear ul n at o:1ce. This fe pro iding excessive uarys — An A fo DE as jllustrati ture for garage J transmls eut and } This be us being shown. ing riv clamp the car the boc and al: twenty ment i car, a car.— Care I Ta fo drivin axles i BOLT DRAIN PLUG - Prov tial for | mean conse or en Bya tappe clean in e¢ the g TI

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the cut ched 1, on ters, ugh oth, hort and the Own read 1 to w = = 2 ble ed and y. 3. been been the the nch- into nt it re a fo a ould one ding nail yhen es a lig. aris the the pull own the vood

February, 1921 eare‘ul not to cut through both sides pet: een the sides of connectors and be at o11ce. This fastener will hold indefinitely, providing the strain thereon is not excessive.—DALE R. VAN HORN. An All-Purpose Headlight for the Automobile DETACHABLE headlight fixture A as shown in the accompanying illustration affords a convenient fea- ture for tire repairing and roadside or garage repair work on the engine or transmission. The lamp support is | cut and a detachable joint made as |

WIRE | A FLATTEN AND DRILL FOR RIVETS | Intl

RIVETS~ h CLAMP SCREW PIPE. —~ BENT ROD

This headlight is removable and may | be used to advantage when repairs are being made at night shown. This joint is a section of tub- | ing riveted to the lamp bracket with a | clamp screw to engage the support on | the car. A section of tubing riveted to | the body of the lamp serves as a handle and also as a reel for winding up about twenty feet of lamp wire. This attach- ment is suitable for either the private car, any truck, or the garage service car.—G. A. LUERS.

| Care and Treatment of the | Main Driving Gears | | HE section of the rear axle-housing | for an automobile enclosing the driving-gears is in a large number of axles only provided with an aperture

PLUG Or coy LEATHER PIPE Y F Lam = —s —

The Comteibutiaa The greatest material benefits the world has re- ceived have come from the laboratories of the scien- tists. They create the means for accomplishing the seemingly impossible. Science, after years of labor, produced the tele- phone. From a feeble in- strument capable of carry- ing speech but a few feet, science continued its work until now the telephone- voice may be heard across the continent. In February of 1881 a blizzard swept the city of Boston, tearing from the roof of the Bell telephone building a vast net-work of 2,400 wires. It was the One Policy

4 _& set 228 com = AMERICAN TELEPHONE AND TELEGRAPH COMPANY AND ASSOCIATED COMPANIES And all directed toward Better Service

sof Sctence worst wire disaster the Company had sustained. Now through the ad- vance of science that num- ber of wires would be car- ried in a single under- ground cable no larger than a man’s wrist. As the fruit of the effort of science greater safety and greater savings in time, money and materials are constantly resulting. And never before as now, the scientist is helping us solve our great problems of providing Telephone service that meets the in- creased demands with greater speed and greater certainty. One System Universal Service

for putting in the lubricant. No means of draining is provided and in consequence the casing is not cleaned or emptied until the axle is overhauled. By adding a \4-in. drilled hole and a tapped-in plug to this case, periodical cleaning and draining is readily done, in consequence of which the life of the gears and bearings is extended.

The filling hole should also be pro- Cleartone Phonographs $4.00 to $200.00 Retail Our Sundry Dept. offers Needles 39c per thousand. Motors $1.35 to $14.75 each. Tone-Arms and producers $1.30 to $5.75 per set. Main springs 2vc to 90c each. Records, Needles, Sapphire Points and Parts at reasonable prices. Write for our 84-page catalogue, the only one of its kind in America, illustrating 33 different styles of Talking Machines and over 600 different Phono- graphic Parts. LUCKY 13 PHONOGRAPH COMPANY Export Dept. 503G. East 19th Street, New York

y ant one exclusive repree YZ sentativeincach locality to use # end sell the new Mellinger Extra-Ply, Uf hand made tires, Guarantee Bond for 4, 8000 Miles. (No seconds), Shipped pre- 4 aid on approval. Sample sectionsfurnished. Donot A, Buy until you get onr Special Direct Prices. Write MELLINGER TIRE & RUBBER CO, Se 1004 Oak St Kansas City,

poconenesscessececceess TOC pecsensocerens Ir

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Sais LEAVING BRIGHTNESS AND CLEANLINESS. | /’ GO THE WHITING-ADAMS ey are spry and catch the nimbie dollars. They Save the Surface, brighten and beautify. *WALL BRUSHES - FILLER BRUSHES - STUCCO BRUSHES: JOHN L. WHITING -J.J. ADAMS CO., Boston,U.S.Ai Brush Manufacturers for Over 110 Years and the Largest in the World

FROM HOUSE TO HOUSE BRUSHES

Send for Illustrated Literature

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Mother Pins Her Faith to Musterole In days gone by, mother mixed a mustard plaster when father had bronchitis or brother had the croup, but nowshe uses Musterole. It is better than a mustard plaster. She just rubs it on the congested spot. Instantly a peculiar penetrating heat begins its work of healing —and without fuss, or muss or blister. Musterole relieves without dis- comfort. The clean white ointment sets your skin a-tingle. First, you feel a glowing warmth, then a pleas- ant lasting coolness, but way down underneath the coolness, old Nature is using that peculiar heat to disperse congestion and send the pain away. Made of oil of mustard and a few home simples, Musterole is uncommonly effective in treat- ment of the family’s little ills. It takes the ache out of grandfather’s back. It soothes sister’s headache. It helps mother’s neuralgia. Mother pins her faith to it asa real ‘‘first aid.” She is never without a jar of Musterole in the house. Many doctors and nurses recommend it. 35c and 6Sc jars; hospital size $3.00. The Musterole Co., Cleveland, Ohio BETTER THAN A MUSTARD PLASTER

AN EASY WAY TO MAKE MONEY 2: : plod along on a small salary, Be independent. Go in the tire res pairing business. One man says “‘I made $60.00 the first day.’’ Others average $200 to $500 a month. Very little capital needed. Jobs plentiful. Every motorist a pos- sible customer, No experience meeded. We teach you. SHALER Tire Repair Outfit Improved Wrapped Tread Method f Used by Tire Manufacturers Does as good wor’ as the big high priced vulcanizing outfits. A boy /7 can use it. It’s the only vulcanizer that has Automatic Heat Control, and can’t undercure or overcure a tire. Requires no watching or regulating. \ * FREE Book **How to Open a Tire Repair Shop.”” It tells how to make big money. Don't delay. Write quick. C. A. SHALER CO. 2101 Fourth St. Waupun, Wisconsin a month a ~ $4 or $5 WILL BUY A Standard, Guaranteed 7 ee TYPEWRITER es : With Every Modern Writing Convenience " Write Today For Mlusirated Circular Explaining Try-Before-You-Buy Plan SMITH TYPEWRITER SALES Co. (Harry A. Smith) 306 —218 No, Wells St.,Chicago, lil,

Make a Pocket-Bib for Your Baby HE pocket in the bib described here catches the crumbs and food particles which the baby drops from mouth and fingers, and prevents them from falling on the clothing or floor. The bib is made, like a majority of This pocket bib will help to keep baby’s clothes and the floor clean baby bibs, preferably of rubberized or other waterproof fabric. To make the pocket, lay the bib on a sheet of paper—about one third the distance from the bottom to the neck, as shown in Fig. 1. Draw the bottom outline of bib on the paper. Around this draw another line, distant from the first line, 34 in. at the bottom, flaring to 1 in. distant at the top edge of paper. At the points A, B, and C, mark V-shaped notches as shown, so that the projecting pieces left shall be the same length at their outer edges as along the inner line. Using this as a pattern, cut out your pocket, allowing enough margin Outsidethe lines foraseam, i— erent and the same Th POCKET along the V FIG.2 “ cuts. Seam the STITCH edges of the V cuts together. Place edge of pocket against back edge of bib and stitch flat, as shown at

Fig. 2D. Turn, bring- Follow this pattern for : : : making one of these use- ing pocket in 41 bibs front of bib, and stitch through, as close to edge as possible, making a turned edge as shown in section at Fig. 2C. Bind top of pocket with tape. The bib complete is shown in per- spective in Fig. 3. The mother may add some individual, artistic touches to her work, but, remembering the purpose for which it is intended, she should avoid everything that would make it difficult or impossible to clean the bib after use.— CHARLES A. PEASE. 98

Popular Science Monthly A Flexible Fastener for Small Belts N such places as printing-shop. anq other places of business where cop. veyors are used, the need of a «mall flexible ‘fastener for connectiny the ends of small belts together ofte, arises. The writer was recently confronted with the task of equipping a irge blueprinting machine with new elastic bands. The old ones had lost their elasticity, the main quality required of them in the rolling of the printed sheet after it had been developed and dried. Wire was first used, but the ends <oon frayed and pulled apart. A more sub- stantial method, which has worked per- fectly for some time, was employed in the following manner: Pairs of tin strips, the width of the elastic belt and 3 widths long, were cut from sheet tin and small holes punched near their edges, as shown in Fig. 1, on a line running through their centers, These holes were punched through with a nail set and ground smooth. Small wires were then cut into short lengths and put through the holes and the ends clenched over, holding the two strips firmly together, also shown in Fig. 1. The ends of the strips were spread with a knife-blade wide enough to

TIN STRIP Y Width La Fic y OF BELT J a i an

NAIL FILED AS SHOWN

BELT. TWO STRIPS HELO 7 7 BY wiRE = < f an FiG.3 | castles FIG.2 FIG 4 Every step in the making of this flexible belt-fastener is here clearly illustrated grasp with the fingers (see Fig. 2) and the bend was completed as in Fig. 3. It will be noticed when this has been done, that a simple hinge has been made, which is held together by the doubled wire. This is now ready to attach to the belt ends, with the exception of punch- ing the tooth-like prongs that dig into the belt, when fastened, and prevent it from pulling out. To make these prongs, procure a small nail, and grind the end to a three-cornered point. This should consist of two broad surfaces and one narrow one. Then finish by grinding off the point until the end of the nail appears as shown in Fig. 5. This, when driven through a sheet of tin, makes a mark similar to the one shown in /'ig. 4. By making a row of these marxs with the prongs along each edge of the connectors, as shown in Fig. 3, the ends of belting or webbing will not pull out when it has been clamped down with a pair of pliers. When using the punch, place a thin strip of wood

February pet veen car ful Ir at once. This f pro idin excessive An A fo DE As illustrat ture for garage } transm|: cut and MEADLIGHT This be us being shown. ing rive clamp the car the boc and als twenty ment ii car, ar car. —( Care N 12 fo. driving axles ¢

4 BOLT DRAIN PLUG Provi tial c for p means consec or em] By ad tapper cleani: in cor the ge The

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and con- mall the ften nted arge astic heir d of heet ried, “00n sub- per- d in the cut ‘hed 1, on ters, ugh oth. hort and the own read 1 to February, 1921 pet veen the sides of connectors and be earful not to cut through both sides at once. This fastener will hold indefinitely, providing the strain thereon is not excessive. —DALE R. VAN HORN. An All-Purpose Headlight for the Automobile DETACHABLE headlight fixture illustration affords a convenient fea- as shown in the accompanying ture for tire repairing and roadside or garage repair work on the engine or transmission. The lamp support is cut and a detachable joint made as NRE FLATTEN AND HEADLIGHT Tit / > GD LU TrirRead RIVETS a \ CLAMP SCREW PIPE, —~ BENT ROD > a This headlight is removable and may be used to advantage when repairs are being made at night shown. 7 DRILL FOR RIVETS | This joint is a section of tub- | ing riveted to the lamp: bracket with a | clamp screw to engage the support on the car. A section of tubing riveted to the body of the lamp serves as a handle and also as a reel for winding up about twenty feet of lamp wire. This attach- ment is suitable for either the private car, any truck, or the garage service car.—G. A. LUERS. Care and Treatment of the Main Driving Gears HE section of the rear axle-housing for an automobile enclosing the driving-gears is in a large number of axles only provided with an aperture LEATHER CPR wasier ELBOW ay . ELBOW FILLER Ui, Wy LeaTHeR ~~” SU DRAIN WASHER DRAIN PLUG PLUG Provide a drain-plug for your differen- tial casing and you can flush the gearing for putting in the lubricant. No means of draining is provided and in consequence the casing is not cleaned or emptied until the axle is overhauled. By adding a \4-in. drilled hole and a tapped-in plug to this case, periodical cleaning and draining is readily done, In consequence of which the life of the gears and bearings is extended. The filling hole should also be pro- The Contributionsot Sctence The greatest material benefits the world has re- ceived have come from the laboratories of the scien- tists. They create the means for accomplishing the seemingly impossible. Science, after years of labor, produced the tele- phone. From a feeble in- strument capable of carry- ing speech but a few feet, science continued its work until now the telephone- voice may be heard across the continent. In February of 1881 a blizzard swept the city of Boston, tearing from the roof of the Bell telephone building a vast net-work of 2,400 wires. It was the One Policy — worst wire disaster the Company had sustained. Now through the ad- vance of science that num- ber of wires would be car- ried in a single under- ground cable no larger than a man’s wrist. As the fruit of the effort of science greater safety and greater savings in time, money and materials are constantly resulting. And never before as now, the scientist is helping us solve our great problems of providing Telephone service that meets the in- creased demands with greater speed and greater certainty. AMERICAN TELEPHONE AND TELEGRAPH COMPANY AND ASSOCIATED COMPANIES One System And all directed toward Better Service Universal Service Cleartone Phonographs $4.00 to $200.00 Retail Our Sundry Dept. offers Needles 39c per thousand. Motors $1.35 to $14.75 each. Tone-Arms and Re- producers $1.30 to $5.75 per set. Main springs 2vc to 90c each. Records, Needles, Sapphire Points and Parts at reasonable prices. Write for our 84-page catalogue, the only one of its kind in America, illustrating 33 different styles of Talking Machines and over 600 different Phono- graphic Parts. LUCKY 13 PHONOGRAPH COMPANY Export Dept. 5034. East 19th Street, New York Y hand made tires, Y/ 8000 Miles. (No seconds). ~ *(Zeshoeent ip =~ , . Jj We want one exclusive repree jo sentativeincach locality to use and sell the new Mellinger Extra-Ply, Guarantee Bond for ” P Shippe dons ce) 5 i tions ished. SA, ecicet our Bpecial ‘Direct Prices. Write wr MELLINGER TIRE & RUBBER CO, pF 1004 Oak St., Kansas C d pre- Donot ity, Me Tpit FROM HOUSE TO HOUSE sD#. LEAVING BRIGHTNESS AND CLEANLINESS ’” 60 THE WHITING-ADAMS BRUSHES They are spry and catch the nimbie dollars. | They Save the Surface, brighten and beautify. “WALL BRUSHES - FILLER BRUSHES - STUCCO BRUSHES: Send for Illustrated Literature JOHN L. WHITING -J.J. ADAMS CO., Boston.U.S.A\ Brush Manufacturers for Over liO Years and the Largest in the World |

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J — {SS j \ —__ ia _ rt —S—————OOO- ——_—— Finish This Picture Fill in the missing lines. See how close you come to the orig- inal drawing. The above pic- ture was drawn by Student Wynn Holcomb. We have a great number of students and graduates whose work appears in magazines and newspapers all over the country. Can You Draw If you like to draw write for our book. Read about our new method Home Study Course in cartooning, illustrating, designing. Learn at home, by mail, in spare time. Become an Artist Illustrators, Cartoonists, Commer- cial Artists make big money. You can earn $25 to $100 a week and more. Learn under personal direction of Will H. Chandlee, famous newspaper, magazine, advertising artist of 30 vears’ successful experience. Book and Outfit Free Complete outfit free to new stu- dents. Write for handsome book, “How Become an Artist.”’ Tells what Course includes, shows many drawings made by Director Chandlee and many students. Write Postal NOW Don’t miss our book. Even if you have no previous knowledge of drawing, our will enable you to become a successful car- toonist or illustrator. Many students earn money while they are learning. If you are ambitious to get ahead, to earn more money, write for our free book and special offer now. You can do as well as our other successful students! Write now for free book, “How to Become an Artist.’’ Mail letter or postal. Washington School of Art, Inc. Room 1112 Marden Bldg., Washington, D. C. Course vided with an elbow connection, such as is obtainable at plumbing supply houses, to facilitate filling with oil. The differential housing contains 8-in. gears, their bearings, and 2 quite soft babbitt thrust-bearings in addi- tion to a ball thrust and roller radial bearing on the driving pinion. These parts rapidly contaminate the oi] with much metallic grindings or slivers that cut the bearings rapidly, especially the babbitt, and throw the gear teeth out of alinement. By draining the case, flushing with kerosene, and refilling every six months | the life of the axle is | with fresh oil, doubled.—G. A. LUERS. Another Use for Old Inner Tubes A* emergency water-bucket can be made from an 18-in. piece of a discarded inner tube; the 41!- or 5-in. sizes are preferable. If possible, use the place where the tube has been set together as the top of the bucket. The lower 3 in. is slit in four places, then turned under and cut so that the edges fit perfectly and form a_ nearly flat bottom. Now _ treat these edges as HANDLE INNER you would a cut in an inner tube when about to repair / it; while the cement is dry- _ ing, cut two A side and bottom 7 by 1 in. strips view of the bucket of patching material and apply them over the edges. Also cut two 12-in. strips 1 in. wide. Apply a thin coat of cement to | the gummed side of one, starting 2 in. from the one end and stopping 2 in. from the other. When sufficiently dry, press the two 12-in. strips together. They form the handle and are attached to the upper end of the bucket by cementing the tube between the loose ends. To make pouring easy, a lip should be cut on the concave side of the tube, and if desirable one of the strips at the bottom can be cut 10 in. long and attached. It also aids in pouring. A bucket 15 by 5 in. weight of water enough to hold 14 gal. with ease. How to Make a Drill-Press for the Bench ARIOUS pieces of wrought-iron pipe and pipe-fittings as shown provide, in conjunction with an elec- tric hand drill, a substantial bench type of drill-press from which the hand drill | can be removed readily when desired. This will apply to practically any type of electric drill with a detachable or screwed handle. With a drill of the expands with the | Popular Science Mo nthly — SEE THE LOF TIS‘ CATALOG FOR ' Special Bargainsin e DIAMOND ais Engagement Rinvs Wedding Rings i a splendid assort. 2 ent of Diamon 25) DIAMONDS eal Bar Pin; here) WINHEARTS Brooches, Ear Sc a Scarf Pins, Cuff Links, Pearl Beads, Watches, Wrist Watches, Chains, Weoffer excep- tional values in Diamond Rin Solitaires and jus ters, latest cn plain and fancy on engrav , Catalog & Whatever you =: a will besent prepaid y us. You see and examine the article right in ‘our own hands, ou can select ag = articles as you wish and - m. hineeh gems 4 Witte. », Green mt * -chasesof $5 or over, one-fifth down, balancein eightequal amounts, payable monthly. LOFTIS BROS. & CO. THE NATIONAL CREDIT JEWELERS D eaf ness Perfect hearing is now being re- Stored in every condition of deaf- } ness or defective hearing from * causes such as Catarrhal Deaf- ness, Relaxed or Sunken Drums, « Thickened Drums, Roaring and sx Hissing Sounds, Perforated. ’ Wholly or Partially Destroyea Drums,Discharge from Ears, etc, Wilson Common-Sense Ear Drums “*Little Wireless Phones for the Ears’’ require no medicine but effectively coeeece what is lacking or defective in thenatural eardrums, They are simple devices, which the wearer easily fits into the ears where they are invisible. Soft, safe and comtortals Write today for our 168 page FREE book on DEAF: NESS, giving you full particulars and testimonials. WILSON EAR DRUM CO., Incorporated 350 inter-Southern Bldg. LOUISVILLE, KY, EARN FNGINEERING Electrical and Mechanical Engineers receive fabu- lous salaries. Thousands needed. We give you thorough personal training from 3 months to 2 years under expert instructors. NOT A TRADE SCHOOL but a PRACTICAL, TECHNICAL COLLEGE teaching electricity {steam, gas, auto- tractor, armature winding, drafting, Extensive labora- tory and shop equipment. DEGREES AWARDED Day and night sessions: enroll any time. Write for free catalog. Earn-while-you-learn-plan. FINLAY ENGINEERING COLLEGE 1002 Indiana Ave. Kansas City, Mo. Dollars in Hares We pay $7.00to$1 8.50 and upa pair and express charges. Big Profits. We furnish guaranteed high grade stock and buy all you raise. Use backyard, barn, cellar, attic. Con- tractand Illustrated Catalog Free. STANDARD FOOD AND FUR ASS’N 407C Broadway New York | LA ATT LS TTS Be A BUCHSTEIN’S FIBRE LIMB soothing to your stumr strong, cool, neat, light fasy pay me “A t Guaranteed 5 Years Send for Catalog Today. P. BUCHSTEIN CO., ties. ~/ 113 6th St.. S. MINNEAPOLIS, MINN Over 100,000 in Use (Opemanrate Gem ie PORTABLE Mostly sold through | |Adding Machine recommen dation For Personal Desk or (t General Offic poses La It checks mental calculations | RMB Uicmere pepe ed Buy through your stationer. | Write for 0-day Trial Offer P. E. Gancher, A. A, Mo. 148 Doses St., New York | nasi en) anadian Agency ' (ae ~\u v 4 Agents wanted * Mult iplies Subtracts & +) February. rigid-han att ach to des ired. mainly of 5 ‘ tees” of pipe o attachme Two p wall are screwed movable The s pipe and i!) || SLIOIN | FIT~ ~FL Buil pipe the drill simple | sure on the end drill poi ment af of the d ture for sary to Tir ER car first ste bottom melted hot sto have b can ise the enc then s solder | side w used

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INN

Fei ruary, 1921 rigid-handle type a bol'ing fixture to attach to the handle can be made when desired. This drill fixture consists mainly of 3 pipe flanges, 2 elbows, and 5 ‘tees’’ joined with screwed sections of pipe of a size corresponding to the attachments used. Two pipe flanges secured to the side wall are the supports. A third flange screwed to a section of pipe is a re- movable table. The sliding ‘‘tees’’ on the vertical pipe and the vertical attachment above SLIDING /ALANGE “Fit al]

ELONGATED SLOT

lly. sa LEVER ELECTRIC

if DRILL i Fa LEVER SECTION pe<—— FLANGE —— SLIDING FIT ~SET SCREW

~~ FLANGE Build this drill-press from pieces of pipe-fittings and an electric drill the drill prevent lateral movement. A simple lever, which increases the pres- sure on the drill above that applied to the end, is the means of feeding the drill point into the work. This attach- ment affords the maximum usefulness of the drill with only a slight expendi- ture for material and the time neces- sary to assemble this.—G. A. LUERS. Tin Can Rain-Pipes to Save Money ERY good rain-pipes or leaders can be made of tin cans. The first step is to remove the top and the bottom of each can. The solder can be melted away by putting the cans on a hot stove. After the tops and bottoms have been removed one end of each can is expanded slightly so as to receive the end of the next can. The cans are then soldered together, a little extra solder being applied to the joint at the side which may have become weaken- ed during the ie melting away Tan of the top and atiry bottom. As tincang each can is ff soldered _ to

| ia ey | the other it is | given a coat Je SPREAD of paint inside AND SOLDERED and out. In this way a very durable rain-pipe is formed that mai 0 answers every purpose __re- Empty tin cans can oe = Oe be —_ economically EONARD used for making BASTIN.

The Velodrome at Newark, New Jersey

IM a AMM MMM ART SPENCER. winner of the American Profes- e S encer Wins sional Sprint Championship Series of 1920 (also 1917) and the $.000 Grand Prize of Newark.

American Championship on a Dayton Pitted against the world’s best, Art Spencer and his Dayton Bicycle came triumphantly through the long grueling test at Newark, N. J. —both man and machine : singled out as worthy of absolute leader- ship through sheer demonstrated merit. Spencer’s skill pluck and endurance counted heavily in the great victory. But in his Dayton he had a smooth-running, fast-flying mount—backed by the sturdy Dayton construction that assures maximum speed with unfailing dependability. Ride the bike that the American Champion rides. G Write to- day for new 1921 catalog No. 44. It contains a full page portrait of Champion Art Spencer in his racing togs. Dayton Ticycles Cycle Division, THE DAVIS SEWING MACHINE CO,, Dayton. Ohio

MARE FIER Ac clemental beak on the cnalitne ow | CONSTRUCTION OF INDUCTIONCOILS EM. An elemental book on the principles, con- ~oen struction and use of an arc system of wicehens telephony. | and Transformers. By T.S. Curtis. Open Illustrated. Price, postpaid, 25 cents | and closed core transformers are both taken up. POPULAR SCIENCE MONTHLY | Price 25 cents 225 West 39th Street New York | Popular Science Monthly - 225 West 39th Street, New York

BE AN oT | Style Vs Bee AUTOMOTIVE || Mii Ett : , Every man knows that Old Style XPERT Automobile and Tractor Me- Shaving is best—but few know how to keep chanics are in demand everywhere. the Old Style Razor in good condition. Just Well trained men earn big money. YOU plain stropping will not produce a perfect can qualify for these positions. We teach cutting edge—a good honing once a week you by daily actual practice under skilled followed jt A tet | instructors. Experience in training pap cs te orrea thousands of mechanics for U. S. Govern- — ment. Course include all branches of automobiles, tractors, welding and tire vul- canizing. Day or even- ing classes. Our free catalog tells how we train men to Occupy ex- pert automotive posi- tions. Send for your copy now. Motor Institute, Inc. 2698 University Avenue S. E.

is the only hone that the inexperienced man can use without fear of over-honing— the holes (patented) automatically remove the rough, scratchy edge that makes the Old Style Razor pull. These holes shear off every particle of ‘‘Wire-Edge.”’ TRY ONE 30 DAYS If it fails to do exactly what we claim—to make your favorite old razor shave like new— return it at our expense, Your money cheerfully refunded. All good hardware and drug dealers carry Perforated Hones — if yours is not yet supplied, send $1.00 direct to us with your dealer’s name. PERFORATED HONE CO.,31S Hammond Bidg. DETROIT, MICHIGAN

Minneapolis, Minn.Mé

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t : BETTER tire re- air method is mak- ingmen RICH! Chas, Evans, carpenter, = past 60, now MAKING $100.00 a weck in shop shown here. Gibbard of Mich., age 62, learned TIRE SORGERY, has shop ‘in’ small town, writes: ‘*C a receipts for May, June and July; 1920, $30,00 is easy tolearn. I will teach you in two weeks, Within thirty _ ys you're started on road = fortune. Car owners EVE HERE demand this NEW re d, as it DOURLES life of aires 28 iilon ing down DAILY. ONE = USAND MORE Tire Sur- ) needed bad OUNY MAN It put $6, 000.00 in bank for John W. Blair, Ohio, a 12 months; got $8,000.00 for Fleming, of New land, within { year; and has aw Lg of hers, There’s money In this business for Investigate tails. Send coupon at once for the FREE book, r Tree P Adee, “fay ‘apitol A mont et ou Dear Sir: $end full details of Tire poltec ing as I want to get into big paying business quickly. Name. = Address.__ ... Cos MakeYour Bike aMotorcycle ASY to do and at low cost. E Your old “foot power” bicycle can be quickly transformed to a speedy, easy-run- ning high power Motorcycle with the Shaw Motor Attachment. No third wheel! Fits any men’s bicycle of any make or size, Chain drive model can be attached inless thanan hour. A boy can putit cn. No special tools or knowledge necessary. SHAW Thousands in use, A light weight 24 H-P motor of wonderful efficiency. Simple to attach. Everything furnished complete. Every owner enthusiastic, All materials are guaranteed. Get one NOW. FREE Write at once for Free Book and Low Direct Factory Price on the Shaw Attachment, also the Shaw Motor-bicycle--a complete power machine at a low price. SHAW MANUFACTURING Co. Dept. 1462 Galesburg, Kansas Roofing at Factory a et et “Reo” Cluster Metal Shingles, ' V-Crimp, Corru- gated, Standing Seam, Painted or Galvanized Roof- ings, Sidings, Wallboard, Paints, etc., direct to you at Rock-Bottom Factory Prices. Positively greatest offer ever made. Edwards “Reo” Metal Shingles cost less; outlast three ordinary roofs. No painti ng errepairs. Guaranteed rot, fire, rust, lightning proo Free Roofing Book Get our wonderfully low prices and free samples. We sell direct to you and save you all in-between dealer’s profs. Ask for Book =m Low PRICED GARAGES Lowest prices on Readv-Made } Fire-Proof Steel Garages. Set upany place. Send postal for oe eowne styles. 248-208 Pike St., Cincinnati, 0. Samples & Roofing Book Make a Tapping-Machine at Home OU don’t have to purchase a high- priced tapping-machine if you adopt the idea shown in the accom- panying sketch. Rig up on a bench a piece of iron of the shape shown, place through this a shaft with a handle and you have a tapping-machine. The square end of the tap fits into a square hole of the BENCH If you have much tapping to do, you will find this little machine a great help tap-holder sleeve. With this machine you can tap all sorts of work at very little cost. The sleeve that holds the tap is removable, so that different sized ends to suit different sized taps can be used. This simple machine means added production wherever holes have to be tapped, and, what is more important, it means fewer broken taps. A Special Stand to Facilitate | Car-Repairing N the small repair-shop it is not always convenient or practical to have a work-pit or a permanent ele- vated platform for removing the auto- mobile far enough above the floor to give free and easy access underneath. A stand that is portable and on which an automobile can be placed in an elevated position is shown in the accompanying illustration. It consists of two longitudinal rails | of wood, 10 ft. long. A center support with two pivots about 24 in. high forms a trestle on which the automobile is pulled by means of a _ winding-bar, Repairs are made much easier if the automobile stands on this trestle above the floor crank, handle, and rope, with a hook to attach to the front axle of the auto- mobile. Two fixed blocks on the for- _ward ends of the rails with two swing- ma Popular Science Moni).ly BIG PROFITS IN WULGANIZING Make $10 to $30 per « with Anderson Steam canizers. Better tir: pairing at one-tenth F usual cost. Big pri j We teach you the famo: derson method of Vulcar also the operation of the A son Super-heated Wailc and Anderson Retrea how to build business in your town little capital. here are Anderson s of vuicanizing in 34 stat the schooling plus eq that makes Anderson ti: ists distinctive. — buy an Anderson Vuica any time we refund yx: and pay you $5 per day ex; money tor each day of t days served because we work you do ANDERSON STEAM VULCANIZER co 101 Williams Bldg. Indianapolis, Ind., U. S. A. JEWEL a RLIPI he Ae wrAT — The masterpiece of watch man- / ufacture—adjusted to me oe chronism. Encased at factory into your choice of the exquisite new watch cases. The great. Burling- ton watch sent on request. Pay at rate of 7. 00a ay month. Yous pay Saly ce— ye pene —the | lowest 5 which the a is sold. color iltustra- Write Today % tions of all newest designs in adage, Lo bat ou} have to joose from. address on at 19th St. and Bied. |.» Chicago, Iilinois Canadian — ice: 338 e Avenue, Winnipeg, Man. Standard Underwoods S- Year Guarantee $ Yes, this genuine Standard Visible Writ- than factory price, yours for $5.00down and than easy monthly payments, oy 10 Days FREE Trial Try it for 10 days Ines our risk. Money hack guarantee. Send pow for free book—bargain offer No, 2142 Lyvemweren EMPORIUM, Montrose and Fao- for 2142 Shipman Building po Ulino es New Big No. 14-200 pp. Wireless , ond 100 pn. Elec'rical Catalog Wireless catalog mailed for 12c and electrical catalog for 6c. You may deduct this amount on first $1.00 purchase. Catalog not sent other- wise. Any wireless amateur will tell you it isthe one catalog to have As an encyclopedia of information ft is invaluable. The largest and most elaborate radio catalog pub- lished. Values that cannot be duplicated elsewhere. THE WILLIAM B. DUCK COMPANY 212-214 Superior St. TOLEDO, OHIO CATALOG 40.94 The William B. Duck Co ANYTHING ELECTRICAL World’s Best Poultry Journal BF os be oo —— th ria’ 4 (eee th ees 20c SEND U. 8. STAMPS Te! etow to keep poultry with greatest prof- - 100 to 168 pages monthly; 27th year. Best articles; ex- rt advice; profusely 7 illustrated, Ayr., $1.00; 8 yrs., $2.00. Reliable Poultry Journal Pub.Co. “Dept. 131 Quincy. Ill. E—==, Build This Phonograph Yourself TREMENDOUS SAVING IN COST Beey, fascinating work, with our SIMPLIFIED PLANS We furnish blue prints, diagrams, enn ‘cabinet pieces, tan uilt horn, ye ou don’t need to be cabinet-mak bad hours assembling and ‘you will have a fine AGENTS at onme- a arter the regular retail p’ NTS MAKE ONEY coe 9 and selling eg in REE Ori ware today for full details and our FREE OFFER. Address: MODERN PHONOGRAPH SUPPLY CO. 454 Springer Building 313 So. Clinton St. CHICAGO, ILL. Learn to Dance YoucanlearnFox-Trot,One-Step, Tw o- Step, Waltz and latest ° ‘up-to-the-minute”’ ciety dances in your own home by the wonderf al Peak _- of Mail Instruction. New Diagram Method. Easily learned; no music needed; thousands taught successfully success absolutely guarant Write for Special Terms, Send today for FREE Swe and Cayo? low offer. WILLIAM CHANDLER PEAK, M.B pr Broadway, 1. Chicago, sia SIMPLE WIRELESS TELEPHONES AND HOW TO MAKE THEM. An elemental book on the principles, construc: tion and use of = arc system of wireless telephony. Price, 25 cents postpa ok Department, Popular Scienc® Monthly, 225 est 89th Street, New York City. February ing bloe support pulled ir lowered. On ac | cli le an ning, th );means O rails. 1] place Vv from cr re also When readily aside. The Al M*s wood ii the gra draw il desirab or conv The: how a = imitat with a be tak each € (see tk side W of th angle A N pe W) age, | Ta equa of pe parts cinec TI past ston rend whe! knifi Sc thro larly

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| cline and the possibility of over-run- i. February, 1921 ing blocks on the rear ends rigidly support the automobile after it is pulled into place and the forward end lowered. On account of the angle of the in- ‘ning, the winding-drum should be the : means of getting the automobile on the rails. Two wedges forward nailed in place will prevent the automobile | from ereeping to the front. Wedges are also placed under the rear wheels. When not in use, the parts are readily disassembled and _ placed aside. The Triangle in Drawing Wood Grain N ANY draftsmen, when they have occasion to show the grain of wood in their drawings, like to have the grain more uniform than they can draw it freehand. This is especially | desirable in patent and other technical | or conventional drawings. The accompanying illustration shows how a triangle may be shaped to | Draftsmen who find it difficult to draw wood grain may use a triangle for the work imitate wood grain. This can be done with an ordinary penknife. Care must be taken to leave intact about 14 in. of each end of the triangle side to be cut (see the sketch), in order that the wavy side will be 90 degrees to the other side of the triangle, thereby leaving the angle perfectly true. A Mixture for Hardening a Soft Grindstone pe a grindstone which was soft and had deteriorated with age, I hardened it as follows: Take 22 parts of rock crystal and an equal quantity of minium to 60 parts of powdered glass, 1 part arsenic, 5 parts of saltpetre and 15 parts of cal- cined borax. This should then be made into a paste with water, and applied to the stone, after which soft stone will be rendered so hard as to emit sparks | when struck with merely a _ pocket- | knife. Soft building stone, deteriorating through weathering, may also be simi- larly treated.—GEORGE H. HOLDEN. Ward o/? pains and stiffness FTER having been at work all day, standing on your feet, lifting heavy weights or “sloshing” around in the wet on a rainy day, it’s a good thing to have a bottle of Sloan’s Lini- ment handy at home or in the shop. Apply it freely, without rub- bing, to the strained muscle, rheumatic joint or aching back, and quickly comes grateful warmth and relief. For 39 years, Sloan's, the World’s Liniment, has bee.i the enemy of rheumatic pains, neu- ralgia, lumbago, and the hosts of “external” aches and pains that lie in wait for the person exposed to the weather or subject to heavy and continuous work. Three sizes—the bigger the bottle the greater the thrift. The largest size contains six times as much as the smallest. 35c., 70c., $1.40 All Druggists have Sloa Linimen After \\~s33 exposure. = or unusual exertion 2] Apol, 2s Y fi 5] icnder or, SEXUAL KNOWLEDGE ILLUSTRATED By WINFIELD SCOTT HALL,M.D.,Ph.D. SEX FACTS MADE PLAIN What every young man and Every young woman should know $1 00 What every young husband and wee L, Every young wife should know Post What every parent should know Mailed paid Cloth binding —320 pages—many illustrations wrapper ‘able of contents, & dations, on request. AMERICAN PUB. CO., 217 Winston Bldg., Philadelphia LAW become ani. This is the only law school in the U, S. which conducted a standard resident school and gives its students identically the same instruction by mail. We are legally qualified and authorized to confer the Degree of Bachelor of Laws — B.—by correspondence. Over 450 lectures deliveredin classrooms and especially revised for our students by a large corps of prominent, practicing lawyers. Our Law Library consists of 24 volumes ‘bound into 12 books) of Students’ Standard Text Books, prepared at an enormous cost exclu sively for the use of our students by one of the largest and most reliable law book publishers in America. Written guar- antee to prepare graduates to pass bar examination. $60.00 course in Oratory and Public Speaking given free. Thousands of successful graduates. Only school of its kind in America. Established in 1910. Write today for Illustrated Catalog which will give you the Facts— the Proof— the Evidence. Hamilton College of Law, 507 Morton Bidg., Chicago OPERATORS NEEDED NOW — GOOD PAY — RAPID PROMOTION Men and boys needed for Merchant Marine, Big Land Wireless Stations, Railroad and y Telegraph Companies, Commercial Concerns, Lake and Ocean Steamships. Salaries start at $125 a morth plus Room and Board, which means more than $200 a month. — our recent graduates is getting $6,000 a year. N or locate in land stations in COMPLETE COURSE BY MAIL. Some of our students have passed the commercial examinations in ten weeks. One of Chance-to see the world America. Start studying NOW in Spare time at home. We furnish FREE to every student, our marvelous new automatic ‘‘Natrometer’’ which transmits wireless messages in 600 differ- ent combinations Operates at any speed from 1 to 30 words a minute. You receive this instrument after your enrollment; it becomes your personal gg upon completion of our course. Write today for FREE INT STING BOOK —— SS weak: a x) %, fGeumel|) NATIONAL RADIO INSTITUTE Dept. 454, Washington, D.C. ER- “Wireless the Opportunity of Today.”

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A Big Raise in. Salary Get, If You Go About It in the Right Way You have often heard of others who doubled and trebled their Is Very Easy to salaries in a year’s time. You wondered how they did it. Was it a pull? Don’t you think it. When a man is hired he gets paid for exactly what he does, there’s no sentiment in business. It’s preparing for the future and knowing what to do at the right time that doubles and trebles salaries. Remember When You Were a Kid and tried to ride a bi first time? You thought ke for the very that you would never learn and then—all of a sudden you knew how, and s aid in surprise: “Why it’s a cinch if you know how.” It’s that way with most things, and get- ting a job with big money is no excep- tion to the rule, if you We Will Show know how. You How Without loss to you of a single working hour, we can show you a sure way to success and big pay. of men in each of the A large number positions listed are enjoying their salaries because of our help—we want to help you. Make check on the coupon you want and we will against the job help you get it. Write or print your name on the coupon and send it in today. American School of Correspondence Dept. G-275 Chicago, Ill., U. S. A. American School of Correspondence, Dept. G- 275, Chicago, IIl. I want job checked — tell ll. a co 65,000 to $15,000 .. Building Contractor re $5,000 to $10,000 | Automot ile A Ngineer | ..... 0 to $10,000 ee... Re pairman |..... $2,500 to $4,000 | Civil ar ty ° $5,000 to $15,000 | ~~ I. “yar r 00 to $10,000 | Business Manae r b scteed to $15,000 | ..... Certified Public Ac- : “countant $7,000 to $15,000 ae pons & Auditor |...... 0 to $7,000 | aes Draftsman & & Designe r | $2,500 to, $4,000 | opel Electrical é a sin $4,000 to $10,000 | .... General Hoeeation : In one year | Name Address. Steam EE 000 ineer ... Sanitary Engineer me how to get it. $5,000 to $15,000 Mechanical ee r 84,000 to $10,000 Shop Superintendent 83, to $7,000 Employ oma t Manage r $4,000 to $10,000 000 to $4,000 ...Foreman’ 4 Course 0 to 84,000 Posieoten Writer $2, ‘0 $10,000 to $5,000 Telephone Engineer 500 to $5,000 Te Jlegraph. Engineer to $5, High Sebotl Graduate In two years ... Fire Insurance Expert $3,000 to $10,000 | A Good Way to Cool Milk Without Ice N the absence of ice, the common method of cooling bottles of milk and other foods is to set them so that the water flowing from the faucet falls upon the top. If it is a bottle of milk, the water spatters and but little flows down the sides of the bottle. ‘If the You need not drink lukewarm milk. If you have no ice-box, put the bottle under the cold-water faucet bottle is placed so that the stream of water strikes only one side, the process of cooling is even slower. In the accompanying illustration a scheme is shown which works well. If a small cup or butter-saucer is inverted over the top, and then placed under the faucet, the water, when turned on, will run down all sides of the cup, and, upon reaching the lower edge, flow under and directly onto the bottle. If this is tried, it will be seen that the dish and bottle may be placed in such a way that water flows down the sides uni- formly. DALE R. VAN Horn. Eliminating Coupling Noises in Your Engine AY TOMOBILE generators and magnetos are driven by coupling from the water-pump shaft. When the coupling is new and all its surfaces are fitted tightly together, it works quietly and efficiently; but after being used some time, it makes a chatter- ing or squeaking noise. To put in a new couplingisa very difficult job, as the magneto must be remov- ed and timed over after the new coupling is inserted. An easy way to overcome this diffi- culty is to make a small leather cover to fit over the coupling. This can be clamped into place by two tin clips bent up and held by two small bolts, as shown in the illustration. A small hole is made in the side of the cover to allow the tip of an oil-can to be inserted. TIN CLAMPS Noisy couplings can be silenced by a leather cover Popular Science Month, Gibson Instruments Mandolin, Mandola, Mando - Cello, Guitar, Tenor-Banjo, Mandolin - Banjo, Cello-Banjo, Guitar-Banjo, Harp- Guitar, Mando-Bass — a 4 e Easy to Play t Easy to Pay ‘ wt MARAE) Select your Gibson now You can soon be playing th music of the day. Your friend y will be surprised and deligh; y fully entertained. Jatusbelpy organize a Gibson Orches in your community. You can i Crease your popularity, income a pleasure by playing for Concerts, Ent: tainments, Church Affairs, etc. A small down payment ar then $5 a month will soon pay for a Gibson and wil! f nish you with wholesome, year-’round entertainment you have an olé instrument, we will make liberal all ance on a Gibson. Write Today for Free Book, Catalo, Free Trial Offer, information about Wm, Place, dr. Bool and the instrument you prefer. GIBSON MANDOLIN-GUITAR CO, 482 Parsons St., Kalamazoo, Mich., U. 8. A. Shoot Without Noise Cut out that unnecessary report noise. Don't scare away all the other game, USE THE NEW MODEL 1920 MAXIM SILENCER Price, 22 cal., $7.00 All larger calibers, $10.00 Send 6c. in stamps for catalogue and BOOKLET of astonishing exper- ; iences of Silencer users. THE MAXIM SILENCER COMPANY 93 Homestead Ave., Hartford, Conn. DO YOU LIKETO DRAW? Cartoonists are well paid We will not give you any grand prize if you answer this ad: Nor will we claim to make you rich ina week. Butif you are anxious to develop your talent with a suc cessful cartoonist, 30 youcan make money, send a copy of this picture, with 6 cents in stamps for portfolio of cartoons and sample lesson plate, and let us explain The W. L. EVANS SCHOOL OF CARTOONING _ 825 Leader Bldg. Cleveland, Ohio Learn Piano! This Interesting Free Book How To i Study | { if Musi of piano or organ In your own home, at one uarter usual cost. Dr. Quinn’s famous ritten Method is endorsed by leading musicians and heads of State "Conservatories. ag | 26 years. Play chords at once and complete piece in every ke sons. Scientific yet ple to understand. Fully iiheateeted. For begin- ners or teachers, old or young. All music free. Be granted. Write today for 64-paze free hook. ‘‘How to Study M M. L. QUINN CONSERVATORY, StudioZB, 598 Columbia Road, Boston. 25 Mass Keep Young Thru Pandiculation You feel the need of exercise. You haven't time. utes use of Pandiculator equals Gives you punch, a2- p. booklet FREE fhe e Pandiculator | re om 15 min- ls 2 hours in gymnasium. *p, and vigor. The lazy man’s gym _343 Advance Bidg., Cleveland. O. MAKE SPECIAL RUBBER BANDS. RED or GRAY SELL THEM WHOLESALE OR RETAIL Own a real a vos ss inthe commercial line. 200 to 400 per cent. profi 0.00 a day easily made on a small scale No expe rience, e ma aeheeeniaee no large fac tory. More used now than ever. INSURANCE COMPANIES. BANKS, COR PORAT IONS, everybody uses them. We sell no books, no formulas, no stocks. or is this a petty mail order propositio A legitimate business proposition in the dollar class. We teli you how. ‘*Fucts in a Nutsheli’’ sent free. PROGRESSIVE BUSINESS COMPANY 6 Van Wagenen St. Newark, N. J 2 Print Your Own cards, circulars, labels, tage, menus eet paper. Press $12. Larger $35. Ji ss $150 up. ve TS EXPE NSELN H ALI 7am SMALL OUTLAY, Pays for itself in short time. W ill last for years. Easy to use, printed rules sent. Print for others, BIG PROFIT. Write factory TODAY for press catalog, TYPE, cards, paper,envelopes. THE PRESS CO., D-33, Meriden,Conn. AUTOMOBILE IGNITION, STARTING AND Lighting, with Questions and Answers. By CHARLES B. Haywarp, M. S.A.E. A comprehensive analysis of the complete electrical equipment of the modern automobile, including many wiring diagrams. 1,024 pp. 740 wiring diagrams and ills. (including 128 blue-print diagrams). Flexible binding. Price, nag 2 Popular Science Monthly 225 West 39th Street, New Y EXCELSIOR shows how you can become a skilled player 5 Fe loc dis cal We sh to fit et

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Le ‘Wi aid rize if laim to ou are }a suc noney, 5 cents ns and lain YONING d, Ohio o! 300k player } min- sium. gym. id, O February, 1921 Marking Metal Surfaces in an Accurate Manner HOULD you need to mark, or graduate any flat metal surface, look at the illustration and you will discover about as simple a method as ean be found, yet accurate in every way. Grind your chisel point to the shape shown, then fasten an ordinary scale to the portion of the piece you want marked. The lo rest is easy, for with the o spring piece A, which rests | -| on each grad- 9 — uation of the : scale, you can lay out what- ever divisions The spring permits the marker to move from one gradation to the next you desire. As - you hit the chisel on the head with a hammer and make one mark, it becomes second nature after a little practice to move the spring part A along to the next indented mark on the scale.—J. W. MOORE. How to Flare Copper and Brass Tubing T is always desirable to flare the ends of copper or brass tubing when fitting it for attachment to carburetors, etc. Many motorists, however, are not so fortunate as to possess any of the special tools on the market for flaring tubes and fear to damage the end of the tube by trying to do the job with ordinary tools at hand. A very good method to flare tube ends consists in boring a block of hard wood 2 in. thick, 2 in. wide by 4 in. Jong, and with a 5/16-in. drill tocut the block in two with a fine saw. This forms the clamp for holding the tube between the jaws of the vise, WOOD the tube being le. BLOCKS inserted in the hole, and then allowed to pro- ject about i ami lg in. at the top. Now, an or- dinary flathead wood screw with a body diameter _per- mitting it to fit loosely in the The split block tube is dropped —_ ~ tubing; } e€ taper of a screw- in the end of head does the flaring the tube and then tapped lightly with a hammer. With each blow the screw will turn slightly. After afew taps the tube will be evenly and accurately flared. If the tubing material is too hard to be worked by this method, it may be softened by heating it in the furnace or over a gas flame until it is red hot and then quenching it in a bucket of cold water. Jobs Open to You $1.75 anhr. Auto Expert $40-$50 a Wk. Chauffeur i) $200 a Mo. Domonstrator $225 a Mo. - Tire Expert $4,000 a Yr. - Salesman ff } $5,000 a Yr, Garage Mgr. | $10,000 a Yr. Gar. Owner Don’t stay a Low-pay man wishing for a good, —— steady income to come through lucky breaks. Make your own luck. Take a short cut to top pay right now. Come to the world-famous Rahe Auto / & Tractor School. In 6 to 8 weeks Henry Rahe will fit you to pick your job in the Automotive Business—the one business that needs ' more men than ever and pays the biggest money. Remember, it’s the Rahe F« School 2 Million Dollars Invested—Nearly 40,000 Graduates Learn Here Easily and Quickly and learn Right. You work daily doing real jobs under Master Instructors on all types and models of real Automobiles, Trucks, Tractors and Aviation Equip- ment. You learn by the Rahe Practical Job Method of Training—-the same metnod of training that has brought succegs and independence to nearly 40,000 Rahe Trained Men in every section of the country. You need no previous experience; no special schooling. Best of Living Conditions. Board and room always reason- able. Plenty of opportunity to earn part living expenses while here. Get my fine 84-page Catalog and Special oN Catalog Free Tuition Offer before you go to any | More Calls for Rahe school orshop. Bothare Free. Write today. HENRY J. RAHE, Dept. 2880. Trained “S Kansas City, Mo. Cincinnati, Ohio Men Than NE i Can Supply! “DON’T SHOUT” “Thear you. Ican hear now as y wellasanybody. ‘How?’ Doxttocetm Cittt meh, set PHONOGRAPH With THE MORLEY PHONE. I'vea pair in my ears now, but they are invisible. I would not know I had them in, myself, only that I hear all right."’ IT’S EASY WITH OUR HELP A few hours interesting work saves over half and gives you a machine to suit your ideas. We furnish motors, tone arms, case material, The Morley Phone for the | [blue prints and full instructions | | Plays any record. Make fine D E A F profit building phonographs for your friends, Write today for our £ Blue print offer. FRE AGENTS wanted for Choraleon King Phonographs Abyone can adjust it. Over one hundred thousand sold. | {| Choraleon Phonograph Co. Write for booklet and testimonials. | 221 2d St. Elkhart, Ind, ~ is to the ears what glasses are to the eyes. Invisible, comfortable, weightless and harmless. THE MORLEY CO., Dept. 797, 26 South 15th Street, Philadelphia. = Wireless Telegraph— Transformers story of the origin Easy fo Play catty Easy fo Pay b With which any amateur can cover great dis- tances. Write today for Bulle- tin on Wireless. This book tells you when to use Saxophone — singly, in quartettes, in sextettes, or in regular band; how to transpose cello parts in orchestra * 34 and many other things you would % ec like to know. aa S You can learn to play the scale In one hour's . ice, and soon be playing popular airs. You B . ean double your income, your pleasure, and your popularity. Easy to pay by our easy payment plan. MAKES AN IDEAL PRESENT G free Saxaphone book and catalog of every- Send fot, frec-Toue band and orchestra instruments BUESCHER 2282 Instrument co, Warren, Ohio FREE TRIAL $ 24,692.01 — 1,021.20 + 16,924.00 —- 12,165.15 + 9,987.02 2 =358.41668 LIKE A FLASH Borrow a real calculating machine to do your problems. Use it fo’ two weeks free. Find out how it automatically adds, subtracts, divides and multiplies with marvelous speed. Equals work of $350 machines. Easy to operate. Accurate and durable. Written three-year guarantee. Send us only $25.00 if you are pleased. If not, return at our expense. SEND NO MONEY—just your business card or letterhead. Do it today! THE RAY ADDING MACHINE CO., Grand Rapids, Mich,

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‘5. GI Expenses PAID YOU have same opportunity! Bea Rail- way Traffic Inspector. Travel or remain near home. Broaden yourself, and your opportunities. Interesting, healthful work. Meet infiuential officials, who reward ability. Position Guaranteed Expenses-and-$110 Monthly to Start You can easily qualify after three months’ home, spare-time study. No books to buy. No expense except moderate fee, returned if position is not secured You Take No Risk! Investigate NOW. Demand for trained men cannot be satisfied. Send for FREE Booklet D-223. Standard Business Training Institute Buffalo, New York learn Mechanical Drawing EARN $35 TO $100 A WEEK AS AN EXPERT DRAFTSMAN We will train you by mail, in your own home through our practical Home Study Course in Mechanical Drafting. By our improved method you will learn Drafting as you would in actual practice in any big drafting department. When you finish this course you will be qualified, as an experienced draftsman, to step into a position paying $35 to $40 a week to start with opportunities for advancement to position of Chief Draftsman paying $5,000 or more a year. The practi cal knowledge of drafting which we will give you may prove the stepping stone to position as Chief Engineer or Manager of Production at a much higher salary. Our graduates are alwaysindemand. Big concerns employ them regularly at good sala-ies, because they KNOW-—because we produce first-class professional Draftsmen. WRITE TODAY FOR FREE CATALOG telling what we have done for others and what we can do for you. It will open yoir eyes to Your Future in Drafting. ROY C. CLAFLIN, Pres., COLUMBIA SCHOOL OF DRAFTING, Dept. 1°77. Washington, D. C. Just turn avalve to cook or heat tHE OLIVER OIL-GAS BURNER Does away with coal and wood — Cheaper. Makes your stove or range.a gasstove. Gives more heat. Keeps your home warmer. No fires tomake. No ashes, dirt, smoke, odor, chopping, shoveling -- carrying coal or wood, Saves hours work. Makes your stove bake better, canst, quicker, Thousands in use over 10 years, Doesn’ te hange your stove, simply sits in fire box, easily slipped fn or out, absolutely sate. Lasts lifetime. Makes its own gas from Coal-oil (kerosene) at small cost. Gives even heat instantly, re much or little. Saves money, ¢ time, labor whether you —. coal or wood, Sol id under money-b — -- 80-day trial, Write for. PR E literature and special introdictory price. AGENTS WANTED (References Required) THERE'S Oliver Oil-Gas Burner = OLIVER OR EVERY STOVE Machine Co., 2UU07 Pine Street, ST. LOUIS, bad “0-.05) T A NAAN vt or rr ‘at Popular Science Monthly An Adjustable Magneto Coupling HE usual means provided for mak- ing magneto adjustments on most old types of gas-engines still in service and on many present types—is by two adjustable flanges on the drive- shaft. One of these flanges has two or three bolt-holes drilled through it, and the other has corresponding elongated slots. By loosening the bolts, slightly turning the slotted flange, and ” B18 HOLES EQUALLY SPACED ‘A’-20 HOLES EQUALLY SPACED FIG.! One of the adjustable flanges has twenty, the other eighteen holes, equally spaced tightening up again, the magneto is synchronized to give its spark at the proper instant. The disadvantages of this system more than outweigh the advantages. While it is possible to adjust exactly to any desired point, the flanges often slip while in operation as they are held ° in adjustment only by the grip of the nuts and boltheads. The accompanying drawings show a flanged connection that can be ad- justed near enough to any desired posi- tion for all practical purposes, and which cannot slip. Figure 1 shows two flanges drilled for two connection bolts flange A has 20 holes, and flange B 18 holes. Figure 2 shows the manner of attaching these flanges to the mag- neto drive-shaft by the usual practice of pinning one flange and fitting the other with a feather key to allow for endwise adjustment. In Fig. 3 the relation of the holes in the two flanges is shown. The flanges are placed so that the opposite FIG2 FiG.3 How the flanges are attached to the magneto shaft and the relations of the holes holes at A and A are in alinement ready for the connecting bolts. The holes at B and B can be brought into alinement for connection by a very slight turn of either flange. A slightly greater turn will Jine up the next pair of holes, and so forth, so that very nearly any desired adjustment can be made. 106 To calculate the value of the smallest possible adjustment it is only necessary to find the angular difference between consecutive holes in the two flanges. Thus flange A (Fig. 1) has the holes spaced 360+20, or 18° apart. The holes in flange B are 360+18, or 20 apart. The smallest adjustment that can be made, then, is 20-18, or 2° for consecutive pairs of holes. By turning two spaces, an adjustment of 4° can be made, and so on around the whole circle by intervals of 2°. Two disks of eardboard cut out and punched as shown will illustrate the principle involved better than any amount of description. Twenty-hole and 18-hole flanges are taken only for illustration. If closer adjustment than 2° is required, flanges with larger numbers of holes can be used, the only limit being convenience in the diameter of the flanges. For a 3-bolt connection, the num- bers of holes in the two flanges must be consecutive multiples of three. In general, if the number of bolts desired be represented by b, the number of holes in the two flanges will be b x n and b(n+1), where n is any whole number selected for convenience. Also the smallest angular adjustment pos- sible for given values of b and n will be a= 360 — 360 bn b(n+1) which simplifies to the form 360 3 —— ' bn (n+1). Luminous Minnows Made at Home X is well known, the ‘glowing lure’’is one of the deadliest forms of artificial minnows that one uses on bass and other fish. These phosphor- escent baits are used at night, for it is from six o’clock in the evening to very near midnight that the bass are strik- ing the Jure at the best. This is ac- counted for by the fact that during the hot days of summer the fish feed at night. The glowing lure in the water is seen and on the impulse of the mo- ment are seized by the fish. The knowledge of how to color and make artificial minnows glow at the same time is known to comparatively few. If the following directions are pursued, no trouble will be had in pro- ducing minnows equal to the best on the market. Four colors with the glowing combination are given, namely, orange, green, blue, and white. To produce the orange coloration with the glow to it, take 46 parts of the best spar varnish, and mix with it 17.5 parts of prepared barium sulphate; add one part prepared Indian yellow; also 1.5 parts prepared madder lake, and 38 parts of luminous calcium sulphide. This gives excellent results. For green take 48 parts of the best Februa spar Vé barium cl romi ous cal parts C pared ultram cobalt ealeiur silica ¢ in asu then a calciur give tk paint ¢ minno and tr new. To S Vi g the un tained less of follow remar| A re camer plate 1 cautio as the ruin t ingly, or wit screen Blue a red sensit obtaiz comp! such j the de no ruil the sy howe’ that 3 red-se a cert find n ness. By to m: clear semb]

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February, 1921 spar varnish; add 10.2 parts prepared barium sulphate. Add 8 parts green chromic oxide, and add 34 parts lumin- ous calcium sulphide. For blue take 42 rts of spar varnish, 10.2 parts pre- ared barium sulphate; add 6.4 parts itramarine blue; add 5.4 parts of soball blue; add 4 parts luminous ealcium sulphide. For white, use silica and whiting, and with this mix in a sufficient amount of spar varnish; then add a goodly portion of luminous calcium sulphide. It is a good idea to give the minnows several coats of the paint as this gives a good coating. Old minnows can be sandpapered down and treated so that they appear like new.—ROBERT PAGE LINCOLN. To Successfully Photograph a Blueprint VERY one who has tried to photo- graph a blueprint is familiar with the unsatisfactory results that are ob- | tained by the usual apparatus, regard- less of the detail in the original. The following method will be of interest, as remarkable results can be obtained. A red ray-filter should be used in the camera and the exposure made on a plate that is sensitive to red light. Pre- cautions must be taken in developing, as the ordinary dark-room lamp will ruin the red-sensitive plate. Accord- ingly, this must be done in darkness or with the aid of a special color- screen on the lamp. When the red- +i sd | Blueprints can be photographed by using a red ray-filter and a red-sensitive plate sensitive plates are bought, it is easy to obtain the proper lamp-screen of a complementary shade of green. When such is available, it is safe to perform the development by this green light as no ruinous effect will be produced upon the special plate. Care must be used, however, to obtain the shade of green that is exactly complementary to the red-sensitive plate that is used. After a certain amount of practice one will find no difficulty in developing in dark- ness. By this simple method it is possible to make from even weak blueprints clear reproductions that actually re- semble engravings in regard to detail. 105 —How to make an Income Tax Return? —How to handle Adver- tising and Sales? —How to Audit by the best methods? —How to make up all kinds of Office Forms? —How to manage a Mail Order Department? —How to protect yourself with Business Law? —How to get Bookkeeping and Filing Efficiency? —How to keep the Books of a Bank? —How to handle Commer- cial Paper? —How to write Business Letters? —How to take an Inven- tory? —How to devise Collec- tion Systems? —How to use Business English? —How to create and man- age a Corporation? NY business proposition you are up against—any modern business method you want to adopt—you can find it all in the Library of Accounting and Business Management as quickly as you find a word in a dictionary—all worked out for you and explained. The whole business world is laid right before your eyes. Accountancy and Business Management These famous books were written to help ambitious men get ahead. Some of the ablest and most successful men in the business world prepared them. These men ac- tually take you into their confidence in these books— give you the benefit of all their experience—tell you the very methods by which they achieved success. This vast fund of money making information is yours for only 7 cents a day and you don’t have to send any money in advance to get it all for a whole week’s free trial. See the partial list of the things the books cover and our Free Examination offer below. 10,000 Vital Business Facts At Your Finger Tips Business Organization, Advertising, Sales, Copections, Credits, Shipping, Purchasing Cost Analysis, Management, Commercial Law, Partnerships, Corporations, Contracts, Bookkeeping, Ac- counting, Trial Balance, Corporation Methods, Inventories, Bro- kerage, Bankruptcy, Auditing, C om Requirements, Specialized Forms, Banking, Retail Store Accounting, Insurance, Real Es- tate, Cost-Keeping, Store Management. Free Examination Mail the coupon for free examination. Don’t send any money. We will ship the books (all 7 volumes) by express collect and you can have a whole week to use them as if they were your own. Give them every test you can think of. Take them to your office. Show them to your friends and ship them back at our expense if you don’t want to keep them. If you do keep the books to help you in your work and to help you earn more money, send us only $2.80. You can send the balance of the $29.80 price the same way—$3.00 each month. Only 10cents a day. This is your chance to double your efficiency. Be the man who knows. The coupon is your start. MAIL IT TODAY. American Technical niaitachoa B-202, Ane 7 Big Volumes — 3000 Pages—2000 Pictures— Plans, Diagrams and Special Business Forms — Bound in Flexible American Morocco. } } | \ ACCOUNTANT “and BUSINESS MANAGEMENT - VOL.VII rs \ ACCOUNTANC and KI BUSINESS | MANAGEMEN! OFFICE Equipment BANKING INCOME TAX PROBLEMS COMMERCIAL ARITHMETIC ~ INDEX BILLS - NOTES EVIDENCE ACCOUNTANCY and BUSINESS MANAGEME VOLV MEN Nat INAS | American Technical Society, Dept. B-202, Chicago, U. S. A. § Please send me set of Accountancy and Business Management in | = 7 volumes for FREE examination, shipping charges collect. will examine the books thoroughly and, if satisfied, will send $2 80 within 7 days and $3 each month until I have paid the special price | of $29.80. If I decide not to keep the books | will return them at your expense within one week. ] — acquTan and —————_— MCOUNTANC! and - MANAGEMENT = wustness MAN NANAGEMENT NCCQUNTANC and BUSINESS cS = = = iS RINLIAN) HANAGEMENT M (Please fill out all lines.) A NTE EE SE NUE eee ae A 107

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A Real Automobile Wheel Haven’t you often wished for a wagon equipped with wheels like those on an automobile? Of course you have— and here’s your chance. The Auto-Wheel Coaster and the Auto-Wheel Convertible Road- ster have standard automobile- type wheels with steel tires They are designed by onainows, on scientific principles THE Auto-Wheel Coaster and the Auto Whed se vadster are real wagons for real boys. Automobile-type wheels are only one good feature about these wagons. Each one is equipped with roller bearings, special hub- eaps, locking pins ‘and a safety brake; and each one is durably constructed of seasoned ash. It is a wagon of true mechanical parts. Organize an Auto-Wheel Coaster Club and become its cap- tain. We will furnish caps to members of the club and send you a special cap as captain. Send us the names of three coaster wagon dealers in your town, telling us which ones sell the coaster with the name “Auto-Wheel" on sides, and we will send you our magazine ‘‘The Auto- Wheel Spokesman”? for six months and an Auto-Wheel Dime Bank —- EE. The SrutoWhed Coaster Conc. The Buffalo 3 Siea Company 157 Schencs Street, TONAWANDA, N.Y In adaie Preston, Ont Export OGer 865 W. 23rd Street, ew York City. p ie Wheel Are You Sour On Society 2? Do you feel like rebelling against every- thing and everybody? Are you sour on society, disgusted with men and hateful with women? If you are, you are bankrupt in health, and lacking in manly vigor and mental courage. lhere’s something wrong—something,. perhaps, you wouldn't want anyone to know. Its a gloomy place to the de- spondent, hopeless, wreck who finds it hard to make his way in the world— who finds himself shunned by women, sidestepped by men, who sees himse if slipping, faltering, and failing in every- thing he undertakes. You need not go on in this way battiin with the world. I can help any man who is Lacking in mental strength, bodily vigor, or physical stamina. I canaid in restoring the impotent. I can give you back your dissipated man- heod. I can give you new courage, increased vigor, more pep. My Free Book **Promotion and Conservation of Health, STRONGFORT Stroagt ane Mental Energy’’—will prove —the Perfect Man Send a 10c piece for stage, etc. to pos address. Tell me your ailment 1 will reply prompuy— you "ih aes vour the truths found in my book and you will see at once a ow era of life is within your grasp. LION EL STRONGFORT Physical and Health Specialist Newark, N. J. Dept. 202 Why Be a Wall Flower? Now you can learn dancing, in your own home, by , from the greatest dancing ieiawasis rs in the country. No longer need you stay at home or sit idly by at parties and © dances. Join the fun. Learn Dancing at Home with Moving Pictures Moving Picture Machine free Instructions and diagrams teach youevery step. Just follow the ’ pictures. Anyone can learn. Teach the children. Waltz, Two Step, Fox Trot, One Step and the new College Rock. Write today for free book. Address A M. SYSTEM OF DANCING INSTRUCTION Dept. 42, 290 Brc adway, New York 2 Make Your Own Popular Science Monthi Sectional Garage By George M. Peterson sa er RIN a Ii Ss | ml | | 2" Oe me mes 2' ey re ee bees celhecian ml ; ¥ REAR SECTION ct FRONT SECTION | REQUIRED D | REQUIRED a BOLT wis | — EE a8 | “ Y4 ROUND $ = \ 4 TORS ¢ 2 5 \ + 5 \ x i } ie * w | z ‘ ost x GLASS | || 4141] “hp | DETAIL CR en aa " DETAIL OF ROSS “SECTION _ yy! IRON ANGLE SIDE ELEVATION WINDOW If you own an automobile and intend to build a garage for it, you will save part of the cost by building it in accordance with these drawings and specifications ae illustrations herewith show a very easily built sectional garage which will be appreciated by those who have tried to get a contractor to build one for less than two or three hundred dollars. The drawings give all of the infor- mation to frame this building, but the exterior sheathing has been omitted purposely. The garage may be covered with shiplap siding, lap siding, corru- gated iron, or slater’s felt, but the most desirable materials would be either A Simple Automatic Camera “Snapper” HEN a snapshot is made of a group, some one has always to be omitted from the group in order that he may operate the camera. The fol- lowing arrange- ment makes it possible to include every member of the party without pulling a string. The camera is prepared as fol- lows: A piece of string is tied to the lever of the shutter release, and slipped over the camera handle or some _ conve- nient projection, thus holding the lever up securely. Then a rubber band is slipped over the lever in such a manner that it pulls downward on the lever. The band is stretched around the camera and fastened in the same man- 108 When the fire of the cigarette reaches the string, it will release the shutter corrugated-iron siding and roof, or shiplap sides and a prepared roof. Corrugated iron may be nailed directly to the studs and rafters, but for pre- pared roofing the roof will have to be covered with boards and the roofing placed upon them. The shiplap siding, if used, may also be applied directly to the studs. The side elevation shown in the sketch shows lap siding and a prepared roofing which makes a garage fit for any location. for All ner as the string to the lever of the shutter release. A coin is placed under the string to protect the camera surface, and the camera is now ready to be placed on some conve- nient object, such as a stone, post, etc., and focussed on the group. A lighted cigarette or a piece of punk is then placed on the string in such a manner that as it burns away it will burn the string. This gives the person preparing the camera sufficient time to take his position in the group before the shutter is released. When the string burns through, the downward pull by therubber band snaps the shutter.—GEORGE FREDERICK. ers, inc TE Won pupils Ukule lutely cess 0 SLING

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February, 1921 “SUCCESS IN ie MUSIC AND Son HOW TO WIN IT” J ~~" HE ie FREE. # OU E THis wondertul book | tellshow tocultivate your musical “bump” for pleasure and profit. Send postcard today for your copy and details of Free Trial of Any Instrument Try a famous Conn cornet, trombone, clarinet any band or orchestrainstrument —in your own home, free. No risk, no obligation; easy payments when you buy and allexclusive Conn features at Sousa Wrote This Book with nine winer world-famous mu- sicians Making big money today. They tel secrets of no greater cost. Highest honors at world expositions, Cc. G. CONN, Ltd. 232 Conn Building. Elkhart, Indiana Agencies in All Large Cities their success; how to discover your talent; how to choose the proper instrument for it; how to increase your income in Spare time; how to win success in a musical career, Interesting inform- ative, inspiring. Send today for your copy. HO ORCHESTRA i" The little matter of 10 ets. will bring you the Pathfinder eight weeks on trial. * The a Pathfinder is an illustrated weekly, pub- ned at the Nation’s center, for all the Nation; an independent home paper that prints all the news of the world a ime and tells the truth; now in its 28th —_. — paper fills the bill with- out anats ng the Will bring oe it costs a@ year. If 4 sent to keep oll posted on what is going 7 in ~ wor at 18 Fr om the least expense of ime or money, this is your means. if you want a paper in your home ations which is sincere, reliable, entertain- ing, wholesome, the Pathfinder is yours. If you would appreciate a pa- per which puts everything clearly, ‘a strongly, briefly—here it is. Send 10c to show that you might like such per, and we will send the Pathfinder on eabatien “elaht A eks. e 10c does not repay us, we_are glad to invest in new friends. Address: THE PATHFINDER. 487 Langdon Sta.. Washington, D.C. Washington has become the World’s Capital and reading the Pathfinder is like sitting in the inner council with those who mold the world’s destiny. CARPENTERS, Shipfitters, Bricklayers, Structural, Concrete and Sheet Meta! Workers, Electricians, Mechanics, Plumb- ers, Pipefitters, Boilermakers and others can earn more money if they know how to read Blue Prints. By oursimple method,we train youina shorttime. Write for Catalog B, stating trade. DRAFTSMAN Earn $35-$150 Week Draftsmen are in demand. Books and tools FREE. Write for CatalogG. DOIT TODAY! Columbia Correspondence School §:.!9°* Carroll Dept. Drexel Bldg., Phila, Pa. 5 Ukulele, Hawaiian Buiter, violin, Mandolin, Guitar, Cornet or Banjo Wonderful new system of teaching note music by mail, To first pupils in each locality, we give a $20 sv~erb Violin, Mandolin, Ukulele, Guitar, Hawaiin Guitar, Cornet, T-20r Banjo or Banjo abso- TENOR BANJ lutely free. Very small charge for lessons only. We guarantee suc- cess or no charge. Complete outfit free. Write now. No obligation, SLINGERLAND SCHOOL OF MUSIC, Inc. Dept. 603 CHICAGO, ILL. Build This Car This nifty little car driven by gasoline motor can be built by any boy. New 1921 now ready. Send 30c for build- to build thie. jad" 7 car. SYPHER MFG. CO., 174 Sypher Bidz., Toledo, Ohio Locking Tool Compartment with Drawer Lock T is frequently desirable to provide a compartment under the work- bench for tools and equipment too large for the bench drawer. When this is done and it is desired to lock the compartment for safeguarding the tools, a method that does not involve the purchase and installation BENCH Y 7 DRAWER WA Se H tock "1 , 4 ANGLE = = = IRON | L ppawer Th | | | DOOR a Pr | TOOL COMPARTMENT } CEI | When the drawer is locked, it auto- maticlly locks the tool compartment of a special or extra lock consists of having an extended metal plate attached to the under side of the drawer that will butt against the compartment door as is shown in the illustration. The door can be swung on hinges to open to one side, or the hinges can be placed next to the floor and the door swung down. With this method on!y the one key and lock are required. —G. A. LUERS. How to Repair that Sagging Garage Door ‘NARAGE doors have a habit of sag- (. ging after a time, making it diffi- cult to close them properly or else necessitating their removal and plan- ing off the bottom. Unless the door is small or exceptionally well made, plan- ing the bottom affords only temporary relief. An easy way to effect a permanent cure for this trouble is to drive two spikes in opposite corners of the door as shown and connect them with a few GRACE) 5 ee Sane. 7 ~ \Gawist ~~ WIRE “sp ie —_— Supported by the tension wire, the garage door will hang without sagging from its hinges lengths of strong wire. Place two blocks of wood under the wire, forcing it out a few inches from the door. Take a third spike and insert it between the strands of wire and twist the wire with 109 Learn Drafting Employers everywhere for skilled draftsmen. good salaries to start with splendid chance for advancement. are looking They are offering Drafting offers exceptional opportu- nities to a young man because drafting itself not only commands good pay, but it is the first 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 step easy delightful way in which you can learn right at home in spare time. For 29 years the Inter- national Correspondence Schools have been giving boys just the training they need for success in Drafting and more ‘han 200 other subjects. ‘“lhousands of boys have stepped into good positions through I. C. S. help, but never were opportunities so great as now. Let the 1. C. S. help you. Choose the work you like best in the coupon, then mark and mail 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. — oe TEAR OUT HE PE come eee eee cee eee BOX 7613B, SCRANTON, PA. Explain, without obligating me, how I can qualify for the position, or in the subject, before which I mark X. _) ELECTRICAL ENGINEER SALESMANSHIP Electric Lighting ang Kys, ADVERTISING Electric Wiring Window Trimmer Telegraph Engineer Show Card Writer Telephone Work Sign Painter MEOHANIOAL ENGINEER Railroad Trainman Mechanical Draftsman ILLUSTRATING Machine Shop Practice Cartooning loolmaker BUSINESS MANAGEMERT Gas Engine Operating Private Secretary CIVIL ENGINEER BOOKKEEPER Stenographer and Typist Cert. Pub. Accountant TRAFFIC MANAGER Railway Accountant Commercial Law GOOD ENGLISH Teacher Common School Subjecte CIVIL SERVICE Railway Mail Clerk AUTOMOBILE OPERATING Auto Repairing Navigation ‘ STA’ TIONARY ENGINEER Marine Engineer Ship Draftsman ARCHITECT Contractor and Rnilder Architectural Drafteman Concrete Builder ) Structural Engineer PLUMBING AND HEATING Sheet Metal Worker Textile Overseer or Supt, ) OHEMIST CJ) Mathematics Spants ()Frenel: | Jitallaa AGRICULTURE (J Poultry Raising Name Present Occupation Street and No City. State. Canadians may send this coupon to 7-26-19 International Correspondence ‘Schools, Montregl, Canada

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PATENTS F YOU HAVE AN INVENTION which you wish to patent you can write fully and freely to Munn & Co. for advice in regard to the best way of obtaining protection. Please send sketches or a model of your invention and a description of the device, explain- ing its operation. All communications are strictly confi- dential. Our vast practice, extending over a period of seventy years, enables us in many cases to advise in regard to patentability without any expense to the client. Our Hand-Book on Patents is sent free on request. This explains our methods, terms, etc., in regard to Patents, Trade Marks, Foreign Patents, etc. If you are a reader of SCIENTIFIC AMERICAN you are probably aware of the fact that it has a special appeal to the inventor. Each issue contains a description of a large number of recently pat- ented inventions. Pending pat- ent legislation as well as the most recent rulings of the Patent Office and the courts are considered in its columns. MUNN & CO. SOLICITORS OF PATENTS 683 Woolworth Building, New York 624 F Street, Washington, D. C. Tower Building - Chicago, IIl. Hobart Bldg., 582 Market Street, San Francisco, Calif. CAN YOU think of a simple, practical idea that will fill one of the many re- quests we have on file for new inven- tions? It may mean a fortune for you. Thousands of things are needed R1Gut Now. Your brains can help. Send to- day for our great new book—“‘Inven- tions and Trade Marks, Their Protection and _ Exploitation’”’ and learn more about making money from ideas than you ever knew before. It tells many things that are wanted, 00. A postal will do— it is free. PATENTS ADVERTISED For SALE FREE In INVENTION And MANUFACTURING SUPPLEMENT. Published for the man with an idea Send for free sample copy. One year’ssub- yi scription 50c. We help our clients, without charge, to get the dollars out of their ideas —having facilities hone others possess, Advice free. Don t delay—-get the book at once AMERICAN INDUSTRIES, INC. [ii 201 Patent Dept., WASHINGTON, D. C. | | | WILLIAM C. LINTON Consulting Engineer and Patent Attorney “Inventor's request. Paten Adviser’’ Mailed free on Gives full information as to ts, Trade Marks and Their Cost OFFICES 364 UNIVERSITY ST., Montreal, Canada. 916 F ST. N. W., Washington, D. C. the spike This will act as a turn- buckle and draw the bottom of the door up. When sufficient clearance is obtained, drive the center spike into the door and you have a permanent repair. In cases where the door has sagged to a great extent, it is better to give the wire only a few turns every day until proper clearance is obtained. Carrying Excess Luggage on the Automobile ERE is a simple method for carry- ing extra suitcases or other bag- gage on an automobile when equip- ment is not provided for the purpose. On the front end of the running- board six small strap loops may be fastened by wood screws. Two loops are set in at the rear edge of the board about 20 in. apart. Another two are set crosswise on the board, a conve- nient distance apart. This is governed By using this method you can materially increase the carrying space of your car by the size ot the package that is being considered. The remaining two are located at the front edge of the board on its under side. The reason for this is that it permits the parcel or baggage to overhang the board. Cord or straps can be arranged to tie or strap over the bundle, the ends being threaded under the loops in a convenient manner. A New Emergency Ford Valve-Grinder HERE a regular grinder tool for rotating a valve of a Ford or similar type of automobile is not avail- able, an impro- vised tool can be made in a few PIECE OF minutes from a BROOM 5-in. section of a N J “ANDLE hoe- or broom- handle and 2 nails or 3/32-in. drill-rods. Drive thesteel pins into the handle firmly, cut off evenly, and bend the points out to correspond with the holes in the valve-head. —G. A. LUERS. NAILS In an emergency a homemade __ valve- grinder will do 110 | Popular Science Month, ses To Hang Things Upon a Needle Point Any boy interested in mechanics can tell you why Moore Push-less Hangers The Hanger with the Twist Se PRE Rare ee will safely hold heavy pictures to the walls. the scientific angle of the point. use the world-famous Moore Push-Pins. on Neither will mar wall paper, plaster or wood work. Suggest a use and we'll send samples free. Sold by hardware, stationery, ’ per 15ck. drug and photo supply stores every where MOORE PUSH-PIN CO., 11-2 Berkley Street, Philadelphia, Pa. Not For light pictures ik cn ended for comfort Eve: “yp air gu aranteed es. AT SHIRLEY: MASSACHUSETTS Catalogue on Request Wational College of Chiropractic (RESIDENTIAL) 16 N. Ashland Bivd. Chicago Unsurpassed facilities for a com- plete Scientific Chiropractic edu- cation. Distinguished Faculty. Mod and extensive pecan td e uipepents Large clinic. Gymnasium. dormitory and etudents’ aid dep Chicago's op- portunity for self help unlimite . Enter quarterly. 3-year term. 14t ear. STUDY AT HOME Become a lawyer. Legally trained men win high positions and big success in business and public life. Greater opportu- nities now than ever before. Be iB ts e10.¢ a leader, Law- to' $10,000 Annually We guide you = bod step. You can train at — ing spare time, We are you for bar exam! tion in any state. Money refunded accordi uarantee Bond if dissa‘ Degree o conferred. Thousands is of successfu students en- rolled. Low cost, easy ‘ourteen volume Law Library free if you enroll now. Sere our valuable 120 page 7 Law Guide’? and ‘‘Evidence’’ books free. Send for them—now. LaSalle Extension University, Dept. 263-4 _ Chicago my our CLASS PINS) FREE CATALOG .05 SnoSucnoer in cuss. — pin illustrated mate with any 3 letters ¢ f) and 2 figures, one ortwo colors enamel. Silver plate, 25¢ ea., $2.50 doz. Sterling silver, 50¢ ea., $5.00 doz. Write for new catalo og. ‘2 BASTIAN BROS, CO. 287}B8astian Bidg., Rochester, N.Y, WHY insects? I buy for collections. each. not spend Spring, Summer and Fall —arniag butterflies, hundreds of kinds Some worth $1 to $7 Simple outdoor work with my instructions, pictures, price list. Get posted now. Send 10c (NOT STAMPS) for my Illustrated Prospectus. Mr. SINCLAIR, Dealer in Insects Dept. 7, Ocean Park, Calif. WHY DON’T YOU Write the Words for a Song? You can doit. Write about Love, Mother. Home, Childhood, Patriotic, Comic or any subject and send poem to me at once. [I com- pose Music and guarantee publication. EDWARD TRENT, 631 REAPER “er Chicago NEWSPAPER AND MAGAZINE ILLUSTRATING, FASHION, PASTEL AND CRAYON PORTRAITS. Earn $50 to $200 a week. By our simple method your talent is quickly developed without interfering with present work. BY MAIL OR LOCAL CLASSES. Write for full particulars. List ot successful pupils, illustrated prospectus. Associated Art Studios, 23rd St. and apunwes 59 B Flatiron Building, New York, N. Febri AS D ause mme alve into © NE ‘ blue chal sepi succ brig G or ¢ add neal littl the tion A one tra} prit mol din cles con 7 on bro an ] ex] wil wa fro the wa

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February, 1921 A Substitute for a Broken Valve-Spring ISCOVERING that the jerky | |) action of my automobile was | aused by a broken valve-spring, I mmediately decided I must tie the alve-stem to prevent it from falling into the cylinder. While preparing to For a limited time a strong rubber band will serve as a broken valve-spring tie the stem, it occurred to me that a strong rubber band might do the work of the coil-spring, at least temporarily. The rubber band R, as shown in the illustration, was attached to the tie-rod directly above the cylinder block and the lower end of it was attached to the notched end of the valve-stem. To my surprise, this substitute worked per- fectly and was used for nearly a week. How to Change Blue Prints to Brown NEVERAL years ago I was making quite a number of photographic blueprints. Hearing of a way to change them from blue to brown or sepia color, I tried it with splendid success, and the prints are still as bright and clear as when first made. Get an ounce of tannic-acid powder orcrystals. Put into a clean bottle and add just enough water to dissolve nearly all of it. There should be a little left undissolved in the bottom of the bottle; this gives a saturated solu- tion of tannic acid. Add one teaspoon of ammonia to one cup of cold water; pour it into a tray or other flat dish. Have the blue- print wet, then put it into the am- monia water until it is bleached to a dingy white color. Then dip it into clean cold water, and put into a tray containing the tannic-acid solution. The picture will soon appear, just as on developing paper. When a deep brown in the darkest places, remove and wash well in running water. Blueprints that have been over- exposed so that they are blue all over will be all right when redeveloped this way if care is taken to remove them from the tannic-acid solution as soon as they are sharp and clear, and at once wash them well.—-CorA HAMILTON. Before disclosing an invention, the inventor should write for our blank form ‘‘Evidence of Conception.’ This should be signed and witnessed and if returned to us to- gether with model or sketch and description of the inven- tion, we will give our opinion as to its patentable nature. a ( Our Three Books Mailed Free to Inventors . f Our Illustrated Guide BOOK ATENT SPECIAL OFFE COPYRIGHTS FREE OPINION AS TO PATENT ABLE NATURE Sent FREE on Request Contains full instructions regarding Patents, Trade-Marks, Foreign Patents. Our Methods, Terms, and 100 Mechanical Move- ments illustrated and described, Articles on Patent Practice and Procedure, and Law Points for inventors. OUR TRADE MARK BOOK Shows the value and necessity of Trade-Mark Protection and gives information regarding unfair competition OUR FOREIGN BOOK We have Direct Agencies in all Foreign Countries. Write for our illustrated Guide Book on Foreign Patents. SPECIALIZATION Our Staff The field of invention is so vast that it is impossible for any one man to become an expert in all the different classes of invention. Only those practically skilled in the class to which the invention relates are capable of rendering efficient service. For this reason Victor J. Evans & Co. employ a number of patent lawyers and mechanical experts who have been selected for their special knowledge and ability in certain lines of invention. Each case is placed in charge of experts in the classes in which the invention relates. THE VALUE OF YOUR PATENT Will depend much upon the skill and care with which your case is prosecuted in the United States Patent Office. This work will receive the benefit of skill and experi- ence acquired by a long and successful practice. We spare neither time nor pains to secure the broadest possible patents that the inventions will warrant. That every case entrusted to us receives our best efforts, and that our work is done consistently, skillfully and thoroughly is evidenced by the many unsolicited letters of commenda- tion that we receive constantly from our clients. We will furnish upon request lists of clients from any State in the Union for whom we have secured patents. Our New York, Philadelphia, Pittsburgh, Chicago, and San Francisco Offices Owing to the growth of our business we have establishe1 for the benefit of our clients Branch Offices in N ; Cal. These branch offices being located in these large commercial cities, together with our Main Office located nearthe U.S. Patent office, in Washington, enables us to more promptly handle the business of our clients, particularly as the branch offices are in constai Office and fully equipped to handle patent business in all its branches ew York City, Philadelphia, Pa., Pittsburgh, Pa., Chicage 1 San Francisco, £O, and t touch with the Main Highest References—-Prompt Attention--Reasonable Terms VICTOR J. EVANS & CO. Patent Attorneys New York Offices Philadelphia Offices | 1007 Woolworth Bldg. 135 S. Broad Street Chicago Offices, 1114 Tacoma Bldg. Pittsburgh Offices TE i) nit v A} i) { i | } as described above. Address ; 514 Empire Bldg. San Francisco Offices, Hobart Bldg. Main Offices, 760 9th Street, Washington, D.C. Gentlemen: Please send me FREE OF CHARGE your books a TRADE-MARKS

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PATENTS SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent Free on request. etc. Send model or sketch and description of your invention and we will give our opinion as to its patentable nature. RANDOLPH & CO. 130 F St. N. W., Washington, D. C. IF YOU HAVE AN INVENTION and DESIRE TO LEARN HOW TO Tells our Terms, Methods, ‘estenteteetententestentedtstenteltententastar UE 0 icc cnn 0000s cues rdes ts souese Seneeee sense STREET | C Free Book on Patents ipplying for a patent write ree Copy of our book 1 a Patent,” which inventors, t tell OV to secure Patents. l or sketch of your inventio our ‘“‘Evidence of Conception” form and our opinion of its patentable nature—Free. Twenty years’ experiencein patent matters. Write today for your FREE BOOK. PATENTS TRADE-MARKS COPYRIGHTS ]| | | Send for our free book of patent information Beale & Park wb ceue.2. ¢ /GEND FOR DON’T LOSE YOUR RIGHTS TO PATENT PROTECTION Refore disclosing your invention to anyone A send for blank form *tEVIDENCE OF CON- CEPTION” to be signed and witnessed. A sample form together with printed instructions # will show youjust how to work up your evl- M dence and establish thesame before filing ap- MB plication for patent. As registered patent at torneys we represent hundreds of inve ntors all over the United States and Canada in thead- B vancement of inventions. Ourschedule of fees B willbe found reasonable. The form ‘Evidence of Conception,” sample, instructions reé lating to obtaining of patents and schedule of fees sent upon request. Ask for them,—a post ecard will do PATENTS AND J \TRADE MARKS 274 Ouray Bidg. WASHINGTON, D. C. Originators of forms “Evidence of Conception.” PATENTS Booklet Free Promptness Assured Highest References Best Results Send drawing or model for preliminary examination of Patent Office records and report as to patentability All Business Given Prompt and Proper Attention WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D. C. I. T. S. Patents Five years ago, practically without capital, J. G. Tufford, Elyria, Ohio, and his associates Smith and Ingwer started business with the now well-known I. T. S. Rubber Heel under the Tufford U. S. and foreign patents obtained through Lacey & Lacey. Fourteen tons of these heels are now produced daily. The profits already amount to many hun- dreds of thousands of dollars and foreign patents have been sold to the extent of $550,000.00. That demonstrates the financial possibilities even of an extremely simple invention of merit properly patented. “PATENT-SENSE GAT € “dhe Book for Inventors & Mfrs” By Return Mail FREE. Write LACEY & LACEY, | Dept.¥-S Washington. Dc, THE MODERN’ ELECTROPLATER,. By K. M. COGGESHALL. A complete and practical book on electro- plating and allied processes. 300 pp., 135 ills. Price, $3.00. POPULAR SCIENCE MONTHLY 225 West 39th Street, New York To the Man With an Idea | I offer a most comprehensive, ex- | perienced, efficient service for his prompt, legal protection and the development of his proposition. ; } Send sketch, or model and description, |} for advice as to cost, search through prior United States patents, etc. Pre { liminary advice gladly furnished with- out charge. | My experience and familiarity with | various arts, frequently enable meto jj accurately advise clientsasto probable || patentability before they go to any }} expense. | Booklet of valuable information and form |! , for properly disclosing your idea, free on |} z request. Write today. i x I} RICHARD B. OWEN Patent Lawyer \ 6 Owen Building, Washington, D.C. 2276-D Woolworth Building, New York City Popular Science Month, A Bumper for the Private Garage End RASH! What wasthat? Just tl hired man running the autom bile into the back end of the garay: Another case of the brakes refusing | take quickly enough. The bumper, which is easily max and will prevent such happenings, shown in the drawing. Two 2 by are cut 3 ft. long, and hinged, one t each studding, next the corner post « the end of the garage. A block of 4 | 4 of suitable length is then nailed each lower end and a stiff flat ste spring, bent to the shape shown an drilled for nails at the upper end, j placed behind each 2 by 4 in th | -GARAGE WALL -HINGE 72° *%4°%3-0° SPRING STCEL = pases — f z*1""2°0 cs. j/ / yt y | WOODEN \ Swe” = | BLOCK ae ait The spring of this bumper must be strong to prevent injury to the recklessly driven automobile manner shown. If tempered steel is not available, an old wagon tire cut in half will serve the purpose. The distance from the bumper to the wall will depend upon the stiffness of the spring and the size and weight of the car, but if the lower side of the bumper rests about a foot from the end of the garage, and the springs are rea- sonably stiff, there will be little danger of severely jarring or starting any of the studding from the foundation. The sharp corner of the 4 by 4, where it comes in contact with the front tires, may be rounded slightly with a drawknife._-DALE R. VAN Horn. They Didn’t Get Away with It YO Smoking! The order was given 4 aboard the Leviathan and most members of the crew observed it. A few, however, went quietly down to one of the lower holds and began to smoke. Two minutes later an officer walked in on them. How did he find out? The men puzzled over this while they went through a round of extra duty for their offense. It seems that the fire- detecting system gave them away. It consists of pipes leading from all the different holds to the bridge. A suction fan constantly draws a supply of air up from the holds to the bridge. Thus when the men began to smoke, a sample of it drifted before the eyes of the officer on the bridge. Februar. This | ge con at the | dia! ete The slo a full le tapered ber at — ‘. oh Split an e1 one an rubber prefera such a an ope soldere burstin Asid the use length satisfac the ak cramp be don A Hunt WV: J there » you ar be car and @ proof paraffi have Cane are k in th a shay closed very light, candle be use tected air yo ting i mica tom.-

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oe ee ee ee

February, 1921 This Eraser Handle Is Made of Bamboo consists of a section of bamboo cut at the joint to insure strength. The diameter of the butt is about 1 in. The slot is cut deep to allow the use of a full length new rubber. The slot is ered from the thickness of the rub- ta] per at the bottom to approximately g handle of this eraser-holder

Split bamboo may be used for audition an eraser holder like that shown here one and a half the thickness of the rubber at the points. A metal band, preferably of non-oxidizing material, such as German silver, shaped like an open thimble, is provided, silver- soldered at the joint to withstand the bursting strain when in use. Aside from the economy secured in the use of the rubber (notice the short length in the acer the greatest satisfaction is secured to the user by the absence of fatigue and _ finger- cramp whenever much erasing has to be done. —C. S. BEARDSLEY. A Waterproof Light for Hunters and Automobilists \ HEN you are on a hunting ex- pedition or an automobile trip, there will often be an occasion when you are in need of light. Matches can be carried in any pocket or matchbox and can be made absolutely water- proof if they are dipped in melted paraffin. In windy weather you may have some difficulty in lighting a match, but if you notch it as shown in the picture, this difficulty will practically van- ish. But a match does not burn very long, nor does it give much light. For cases of emergency, a candle attached to the cover of a shaving-soap box and carried in the closed box to protect it, will be found very convenient. When you need a light, unscrew the cover and use it as a candlestick. Of course the candle can be used only in a place where it is pro- tected from the wind. In the open air you will have to protect it by put- ting it inside one of the old-fashioned mica lamp-chimneys open at the bot- tom.—WILLIAM LORENCE.

cS oui oe matches are kept water-proof in this box 1 |

| | | | DRAWING. OUTFIT

you at once. pleasant and profitable. get the big salaries. hold permanent, big paying positions my individual instructions. Correct you. draftsman and designer. For Big Book the coupon and send it to me today. you my new book, and my great special offer. No obligation. in line for a big paying position. the first step. CHIEF DRAFTSMAN DOBE Dept. 1362, 4001 Broadway

Yes, I will give you this complete drawing outfit absolutely free. The instruments are regular draftsman’s working in struments, in a handsome plush lined folding case. I will give you absolutely free, a 20 x 25 inch drawing board, 24 inch T square, a 12 inch rule, a supply of drawing paper, two triangles, curve, pencils, erasers, thumb tacks, etc. You have them to work with from the very first day. Be a Draftsman There is an urgent demand for skilled draftsmen. calls every day for men to fill positions paying $3,600 a year. Get in line for a big paying position. fIinstruct You Personally I am a Chief Draftsman of a well known firm. know just the kind of training needed by men who I train you with actual, prac- tical work, the kind that you must be able to do to I give you I see you through. Help you quickly become an expert Send Coupon Put your name and address on I will send “‘Successful Draftsmanship”’ Get Getting the book and full particulars of the special offer is Chicago, tli. | pa

Besides. : a French The complete outfit is delivered to Draw $3600 Per Year ! Companies are issuing Work is light, Pay As You Wish What I want is the right kind of men. Don’t bother about expense. I will give you the working outfit free if you get inat.once. I charge a very small fee for training you to be an experienced draftsman. You can pay the small cost as suits you best. I

CHIEF DRAFTSMAN DOBE Dept. 1362 , 4001 Broadway, Chicago, Ill, Without any. obli gation whatsoever, please mail your book, “Successful Drafts manship,"’ and full partic “ulars of vour liberal ‘‘Personal In- i struction’’ offer to a few students Post OFfiCE .....00+ veccecccses -StGlO, .ccccccccccce®

EXPERIMENTAL WIRELESS STATIONS By P. E. Edelman. The theory design, construction and operation is fully treated including Wireless Telephony, Vacuum Tube, and quenched spark syste <" 24 chapters. 167 illus. Price, Popular Science Monthly 225 West 39th Sieet, New York | | a REPAIRING MADE EASY ctor W. Page A thorough!y practical book containing ete direc rose. making repair parts of the | motor car mechanism | 1,056 pp. Popular Science Monthly to al Price, $4.00 225 West 39th Street, New York

Law Trained Men Win A’great number of big business men owe their success to law training. Follow their example. Send for our FREE BOOK today. AMERICAN SCHOOL Dept. L-275, Drexel Ave. and 58th St.,

Chicago YOUR PATENT ATTY

' 311 Main Street To be most efficient must bea man of various | In Att’y W. E. Baff you find the rare combination of proven technical skill protecting inventions, coupled with first hand knowledge of marketing thereof gained | as an author of a standard work \sk for booklet. } | BAFF PATENT LAW OFFICE Mass Worcester,

Free Book telling How to Obtain a Patent. invention for Preliminary Examination and advice Charges reasonable. SEND SKETCH OR MODEL TODAY FOR ADVICE—GET OUR FREE BOOK AND RECORD OF INVENTION FORM J. L. JACKSON & CO., 122 Ouray Building, Washington, D. C. SECURED PROMPT SERVICE Avoid Dangerous Delays. Send for our “Record of Invention”? form and Send sketch or model of your FREE. Write TODAY.

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Have Cozy Rooms For 20c a Day Now made possible by the latest Larkin Factory-to- One to three rooms furnished com- for only 20c a day. 1000 Beautiful Furnishings Await Your Choosing Welcome surprises await you in the large f furnishing you can do at small expense. q y Furnishings of tasty easy term Family plan amount High and beautiful design, on , at rock-bottom prices surely merit your investigation. Big Helpful Book Now FREE Every one of its 128 pages contains intensely interest- ing offers for the home lover Write for your book now. Larkin Ca, Inc. Desk FPSM-221, Buffalo N. Y. No Bafteries Needed with this FLASHLIGHT Hand generated current gives brilliant light at no oper- ating expense F lect: o- Avctomate $7.80 Postpaid These flashlights were manufactered to sell at $15.00. This is a special introductory offer and only a few hundred will be sold at this figure. Nothing to get out of order,—lasts a life- time,—no parts to renew. Order at once— send money order, check or cash to Elsaesser & Watts 136 Liberty St. New York City —E - WANTED! RAILWAY MAIL CLERKS $1600 to $2300 a year. Common education sufficient. No ‘pull’ neces- § sary. Mail cou- pon for Cata- ® log 92. % Examinations soon. Steady life-time job waoneseveesccececccsen, e Patterson Civil Service School, % Rochester, N. Y. ° Sirs Send me without charge your @ Patterson Civil Catalog 92 describing this and other © Serviee School fine U. S. Government positions. % Rochester, % N.Y. PN Ks ebukasocssseeeunnsvassabeessene * DEEN tha kocevnGhesn cee baebsadsautc cre COMPRESSED AIR, By Louis J. Wight- man. A reference work on the production, transmission and application of compressed air; the selection, operation and maintenance of compressed air machinery, and the design of air power plants. Price, postpaid, $2.10. Popular Science Monthly, 225 W. 39th St., N. Y. City Popular Science Monihly Building a Simple Charging Panel By Robert A. HE panel de- scribed here will be found very useful for a small garage or for private use. It is easily made and portable, but the electrical fit- tings must be bought from a reliable house so as to cover un- derwriters’ re- quirements. This apparatus can- not be used on alternating cur- rent. 14-ft. No. 14 rubber-covered wire 1 fuse-block (plug type) and switch (double pole, single throw, 125 volts, 25 amp.) 1 self-closing box for same, with 4 bushings 4 or more plug fuses, 10 amp. each 4 porcelain cleats 1 porcelain knob 2 porcelain tubes, 4 in. 12 lamp sockets 2 connector plugs for flexible cables 2 lengths of flexible cable, one long enough to reach from lamp socket to panel, the other to battery on automobile 10 carbon lamps, (provided by company) Asbestos card or paint, as desired 37 screws, rubber tape, friction tape, soldering apparatus. 100 the watts each electric-light If a drawing-board 16 by 32 in. is available, it will do, but it is slightly small. If one is to be made, have it at least 18 by - 24 in. This r should be paint- | ed a dead black | & ' 10 AMP FUSES with lampblack and shellac, as it , TY makes it less See trying on the S » eyes. White paint makes a_ neater CLEATS appearance, but white enamel gives too great a glare. Some electricians use a “On LO FO LO vee UBES + Provide the : following equip- ne gc gy nance ta ment before one like that shown here starting: 1 drawing-board, 16 by 32 in. or larger 3 WALL SOCKET PLUG 5 SOCKETS ae Chandler not required jy the underwriters. If the board jg not neat enough, it may be sand- papered with No, 00 grade and finished with varnish or shel- lac. Set the fu es next the line, and the switch so that if it falls (due to loose- ness of the joints it will not close and cause trouble. It must be completely covered by a metallic box which closes by its own weight or by a= spring, Where the wires enter and leave, the holes must be bushed. This is to pro- tect the insulation. Either weatherproof or rubber-cov- ered wire must be used. As the lamps give off considerable heat the weather- proof is best, but the underwriters re- quire rubber-covered wires when they are exposed to acid fumes. If the panel is to be used in a private garage and only occasionally, the weather- proof will pass inspection, but in a public garage none but rubber-covered wire will be allowed. Size No. 14 is the smallest permissible. As it will carry 15 amp. safely, there is ample margin. Where a wire ends at a lamp socket or switch, the end should be turned over to form an eye for fast- ening. The lamp sockets are of the stand- ard type for house lighting. If a 100- watt lamp (32 candlepower, carbon filament) is screwed into one, it allows about 1 amp. of current to pass. If only 14 amp. is required, an ordinary 16 - candlepower (50-watt, carbon filament) lamp J LARGE DRAWING can be used, but BOARD this is seldom required, as a variation of 1 amp. is_ suffi- ciently close for | a this work. Be sure to use car- ; bon lamps, as they permit more == current to pass. 4% APART thin sheet of as- bestos card over the whole sur- face, as it di- minishes the fire risk, but this is FIG| 114 The wiring of the charging panel and the proper way of connecting the batteries are illustrated by this diagram aad More sockets wm 1 may be added if = IN athena a greater charg- er ee ing capacity is required. But riG2 not more than 15 can be sup- plied by a No. 14 wire. No. 12 |) ar. > me a: al | rr Februai wire Mm: supplyi Note come cl cleats ] 1, in. one pas tupe nN securel he rezit to the bat carryir to sta cord is vided the pal place ‘ Hav satisfa compa Jamps. Hav supply and n This is to be the lig have t Do no line, a After ¢ It v polari batte! and ¢ trolyt the h nake of tab veniel two the e1 which and § other markt ner— knot be te: necte Fo! panel tive Vv is git “Star ever screw Thos cate 3 an e¢ whicl cells at 2 i If chars conn tive) patte of th atte the are 1 the 1 necte

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ust ely Ox by he ro- Ips er- re- ey he ize eT- er

February, 1921 wire may be used with 20 sockets for supplying 20 amp. of current. Note that the wires must nowhere come closer together than 2!gin. The cleats keep them at this distance and 1, in. away from the board. Where one passes under another, a porcelain tube must be used. Tape the ends securely so that the tube will not shift. ‘he two cables used to supply cur- ret to the panel and to connect with the battery should be of the twin type, carrying two wires, and heavy enough to stand rough usage. Twin lamp cord is too light. Each should be pro- vided with a connector plug so that the panel may be moved from place to place as required. Having finished the board to your satisfaction, notify the electric-light company and make requisition for the lamps. Having chosen the lamp socket to supply your panel, follow the line back and note the size fuse on that branch. This is usually 6 amp. If 10 amp. are to be used at the board, and some of the lights burn as well, the fuse will have to be large enough to cover this. Do not use more than 15 amp. on the line, as that is all the wire should carry. After charging, replace the 6-amp. fuses. Find the Wire Polarity It will) now be necessary to find the polarity of the wires that run to the battery. Provide a tumbler of water and drop a half-teaspoonful of elec- trolyte into it from the battery, using the hydrometer syringe. This is to make it a better conductor. <A pinch of table-salt may be used if it is incon- venient to use acid. Now place the two wires in the solution, keeping the ends slightly separated. The one which gives off bubbles is the negative and should be left unmarked. The other is the positive, which should be marked in some unmistakable man- ner—by a piece of tape, string, ora knot tied in it. The polarity should be tested every time the panel is con- nected to a different socket. For charging, connect positive of panel with positive of battery and nega- tive with negative. The charging rate is given on the side of battery, as, “Start 15 amp., finish 5 amp.,’’ or what- ever it may be. This is obtained by screwing in as many lamps as required. Those that are passing current indi- cate it by lighting up, so that we have an easy way of knowing the rate at which the battery is cherging. If the cells bubble over, we unscrew a lamp at a time and reduce the charge. If two or more batteries are to be charged simultaneously, they must be connected in series (positive or nega- tive), Then the positive of the end battery is connected with the positive of the panel, and the negative of the battery at the other end is attached to the negative of the panel. If the two are to be charged at different rates, the two banks of lamps can be con- nected with them as shown in Fig. 2.

Learn Electricity

In the Great Shops of COYNE +m 312 MONTHS I have an important personal message for YOU. As an electrical expert you can make to ; tart —two to three times what you are earning now. MAKE $65.00 TO $175.00 A WEEK! If you want a raise in pay—raise it yourself by becoming a COYNE TRADE ELEC- TRICIAN, No need to take one to four years to become expert. We train you in everything from the simplest bell systems to the mighty generator, and you learn fast and sure by doing the actual work on our immense equipment. Thousands of our boys have become Superintendents, Power Plant Operators, Electrical Engineers, Automotive Engineers, etc., and you can do as well as they. Come with us for 98 days—3!4 months and get the pr: actical Electrical Training you need, through the fascinating system of instruction perfected at this oldest, largest, and best-equipped Electrical Se hool in Amerie: 7 Earn While You Learn Course in Automotive Electricity It is surprising how little money you need. Don’t FREE let the money question hold you back. If you need For a limited period we make this astounding money our influential employment departm nt will offer—the finest training in th® finest ps it help you secure a part time or full time job without jeg —on Batteries, Ignition, Lighting and Startin charge. We have aided hundreds and we will help Systems—FREE. This is a wonderful opportunity you. Write at once for free particulars, and our for you. Get full particulars NOW, wonderful catalog-full of hundreds of photos of our od shops. It is FREE. Dept. 32 Bennett Wellington Coke, President j ee —— inots 5St., nicago, . COYNE TRADE AND ENGINEERING i Without obligation on me and fully prepaid and SCHOOLS free, send big catalog and full details. 39-51 E. Illinois St., Chicago, IIl. Name i Address... <. Dept. 32,

‘You CanSave $50.00 NPT |, CARPENTRY LEARN AUTOS AND | By GILBERT TOWNSEND, S.B. TRACTORS A practical treatise for the use of carpenters and wood Wonderful opportunities constant- | workers on simple building construction, including framing, ly offered trained men; we train | roof construction, general carpentry work, and exterior and you thoroughly tostart your own interior finish of buildings 258 pp., 368 ills Price, $2.10. business or make good money as ater capert. G:iver, sham tare Popular Science Monthly, 225 | West 39th Street, New York man, etc. - pose 5000 graduates making good. Catalog Free. Cleveland Automobile School, | 1821 E, 24th St., Cleveland, Ohio

A Sure Guide to Better Gardens It will show you how to

By recovering your old

auto top fr ame yourself. produce large, healthy, We cs trent 2 ig care. vegetable crops—howto ise person that can drive a | | ) have beautiful flowers. carcanputiton, We furni ish | instructions. Roof and quar- Parcels Post Paid ters sewed toge ther with THE MAULE rear curtain, fasteners, welts and tacks. All comple Give us the name, year and mc xdel number of your car and we w iti send you ir cat alogue with samples and quote you exact price LIBERTY TOP & TIRE CO., Dept. E8, Cincinnati. O FREE ‘ SEED BOOK This 176-page illustrated catalog tells what

seeds to use; whenand howto plant them. All the secrets of gardensuccess. Send forittoday.

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Ready to ha Direct from: sasitaiconwve, | Completely wired including glass- | | 4 t 4 —_ ely wired including gla | a a & Send for Catalogue No. 20 | fs ERIE FIXTURE SUPPLY CO. | | BRchakeiecives 2b “ ip Desk A, Erie, Pa. | Always Grown

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Your Choice /5c a Week With every set is included — FREE —a Consulting Membership which gives you the privilege of submit- ting your perplexing problems to a corps of experts for an entire year. This Consulting Membership regu- larly sells for $12.00. No matter what your occupation, one of the home study sets listed below will juickly fit you for a better job and bigger pay. Any set you select will be sent for seven days’ examina- tion, and if you decide to buy you may pay the rock- bottom price at the rate of only 75c a week. But you must act now! We cannot guarantee these reduced prices for any great length of time. These books are the work of recognized authorities. They are written in plain, easily understood language, by recognized authorities, and contain hundreds of photographs, diagrams, tables, etc., that make diffi- sult points as simple as A-B-C. Handsomely and durably bound in half or full morocco leather (except 1s noted), and stamped in gold. Pay-Raising Books At Greatly Reduced Prices Down go the prices. nders to cut the passed on to you. Accountancy and Business Management, 7 vol., 2700 pages, 1000 pictures. Was $52. 50 ICG Aah se Skate sau awe caw ae Now $29.80 Carpentry and Contracting, 5 volumes, We induced our printers and price we pay them. This saving 2138 pages, 1000 pictures. Was $37.50. Now 24.80 Civil Engineering, 9 volumes, 3900 pages, 3000 pictures. Was $67.50 ....... Now 39.80 Electrical Engineering, 8 volumes, 4100 pages, 3300 pictures. Was $60.00 ...Now 34.80 Automobile Engineering, 6 volumes —_ pages, 2000 pictures. Was $45.00....Now 24.80 Machine Shop Practice, 6 volumes, 2300 pages, 2500 pictures. Was $45.00...Now 24.80 Steam and Gas Engineering, 7 volumes, 3300 pages, 2500 pictures. Was $52.50, EE ee ee eee 29.80 Law and Practice (with reading ‘course), 12 volumes, 6000 pages, illustrated. as a EE eee ne re Now 49.80 Fire Prevention and Insurance, 4 vols., 1500 pages, 600 pictures. Was$30.00..Now 19.80 Telephony and Telegraphy, 4 volumes, 1728 pages, 2000 pictures. Was $30.00 ._Now 19.80 Sanitation, Heating and Ventilating, 4 volumes, 1454 pages, 1400 pictures. Was IRS's ss 5c Sin Ago Mie ewce & Now 18.80 Drawing, 4 volumes, 1578 pages, 1000 Xs tures, blue-prints, etc. Was $30.00...Now 19.80 Send No Money Shipped for 7 Days’ ney Yes, we'll gladly ship any set right to your home or office upon your simple request. Pay only shipping charges when the books arrive. Don't send a penny until after you have used them seven days, then re- mit only $2.80 or return them at our expense. Pay balance at the rate of $3.00 a month—75c a week. Act now—while these splendid books are being fiered at 20% to 50% less than regular prices. This ffer is open to every person within the boundaries of the U. S.and Canada. Grasp y our opportunity— fill in and mail the coupon NO American Technical Society, Dept. XX-202, Chicago rican Techical Society, Det. XX-202, Chicago, U.S.A, | ~ American Technical Society, Dept. XX-202, Chicago, U.S | Please send me set of ee for 7 DAYS’ examination. shipping charges collect | I will examine the books thoroughly and, if satisfied will send $2.80 within 7 days and $3 each mantn. until I have paid the special price of decide not to keep the books, I will notify you - a. and hold them subject to your order Title not to pass to me until the set is fully paid for. NAMB... -cccccccccccccevesesccvececccocsccsccece ADDRESS. 2. cece ec es eres ec eseeeesessecssesesees fi | REFERENCE ..... Serre er | AT LT Ne A Sa | Popular Science Monthly Make a Xylophone in Your Own Home 9 you like xylophone music, it will pay you to make such an instru- ment in view of their present high cost. The frames must be made first. Use hardwood strips °¢ in. thick and cut to the dimensions given in the de- tail diagram. One of the frames is 21% in. high, the other 315 in. Saw the ends at an angle so they may be mitered. Glue a double layer of thick felt lengthwise along the top edges to within 2 in. of each end. The bars are to rest on the felt. These bars are made from strips of hardwood flooring. Saw off the grooves and tongues from each side of a FIGS 8 A (ae | | i HINGE te eS te eee ewer ese + CDFGA DRILL FOR ROPE CD EF GABCDEFGABCDEFG FIG.2 Make a xylophone for yourself accord- ing to directions. Your neighbors will appreciate it the strips and plane them smooth. Bevel the two top edges slightly and round them off with sandpaper. No specific directions can be given for the length of the bars for the various notes as it differs with the kind of wood used. The length of each bar is to be determined by trial. Cut several pieces from 14 ft. to 114 ft. in length and lay them on the felt on one of the frames. By striking them with the handle of a screwdriver you can de- termine their pitch, comparing each tone with the corresponding note on the piano. If the tone of the bar is not entirely true, it must be tuned. Planing off the ends raises the tone. If the tone is too high, tune it for the next higher tone on the piano. Label each bar properly tuned with the note it represents. Cut enough of these strips or bars for the 32 notes of the instrument, which has a range of two and a half octaves. Figure 2 shows a suitable scale of notes for such an in- strument. The high G corresponds in pitch with the highest G on the piano. After all the bars corresponding in tone with the white notes on the piano are cut, lay them on the lower frame in their consecutive order, space them evenly, and arrange them so that the distance between the notes will be the same on the whole frame. Now, with a long straight edge, draw a line along all the bars, above the middle of the pieces composing the frame. Make a punch mark in the frame halfway be- tween the bars and insert a screw-eye in each hole capable of holding a 14-in. 116 rope. Remove the bars and dril! holes through each bar to correspond with the lines marked on them. Re- place the bars and fastening a piece o l4-in. rope to one end of the fram: with a couple of staples, string th; rope through each bar and screw-eye At the end of the frame turn to th: other side and fasten the bars on th other side in the same manner. Nex? set the other frame side by side wit} the one already completed, place on i: the bars corresponding with the blac! notes on the piano in their respectiv: order, and fasten them just as the bar representing the white notes wer: fastened. Then turn both frame: face down and connect them by strips 1% in. by 2 in., so that the bars of the second frame overlap but don’t touch those of the first. Cut these strips with the saw halfway between the two frames and connect them by hinges. The instrument can then be folded and is easier to carry. Varnish all woodwork, which will improve the appearance and durabil- ity of the instrument. Mallets for playing the instrument may be made by drilling holes in two wooden parlor- croquet balls and inserting a wooden handle in each. If you wish, you may obtain hard rubber mallets intended for this purpose at any near-by music- store.—-CARL CHASE. Steam-Heated Sidewalks Will Clear Snow Away URING the winter’ season, especially when there is heavy snowfall, a steam-heated sidewalk will save a great deal of time, labor, and expense which would otherwise be necessary for removing the snow. As shown jin the illustration, the steam-pipes are laid in the cinder-bed TO BOILER—| — —RETURN BENDS a | BLECD AND VENT 7 yr House FRONT VENT TRAP FEED FROM BOILER SIDE VIEW OF SIDE WALK RETURN TO. BOILER aS | | | - of the sidewalk before the concrete is put on. The more coils, the better it will be. The pipes should be of gal- vanized iron. The bleed and vent traps do not necessarily have to be in the sidewalk, but may be placed in the basement, connected with the pipes by the bleed- pipe, and provided with an air-valve to release the condensed water and air. Snow will not accumulate on a steam-heated sidewalk BASEMENT Februar 10c Be vutiful m so;ely finis Larkia ( Av N i ienentieneete A thor directi motor motor knowl detail titude able ti 1056 Por 225 V —— pa for € hoice oO of famol to-Ride buy anys ire SEND trated f: Dept.

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February, 1921 10c to 25c a Day Pays For the Symphonola Re \tiful models in genuine Oak, Walnut, Mahogany Hand- soiely finished. Compare tone, construction, price, terms, with higher priced phono- graphs. See the saving. Over 2 Years Time for the beautiful Period Model here shown. 18 mos. —2 yrs. on other popular models. Convenient month ly payments. Enjoy your Symphonola while paying Plays All Records Using steel needles, as Sym- phonola, Victor, Columbia, Emerson, without expensiv< extra attachments; Pathe or Edison Records with sapphire or diamond points. Records 70c Postpaid Symphonola Records play- able on any phonograph. Contain best of music. Get our latest Record list, and save money. Beautiful Book FREE Illustrates Symphonolas in natu- ral colors. Full details, prices, terms, construction. A postal quic’ ‘kly brings it. Get your copy NOW-— It’s FREE. Larkta Co Inc- Desk SPSM- 21 Buffalo, N. Y.

Automobile Repairing Made Easy VICTOR W. PAGE A thoroughly practical book containing complete directions for making repairs to all parts of the motor car mechanism, explained so simply that motorists and students can acquire a working knowledge of automobile repairing, while its detailed instructions and information ona mul- titude of subjects of interest make it indispens- able to the garage and repair man. 1056 pp. 590 illus. Price, postpaid, $4.00

Popular Science Monthly 225 West 39th Street New York

Pélivered to you Free, * for30daystrialonapproval. Your choice of 44 Styles, colors and sizes of famous Ranger bicycles, Factory- to-Rider lets you_buy at wholesale prices, express prepaid, direct from maker. lets you enjoy 4 1 QMonthsto your Ranger |r at once. Many boys and girls easily save the small monthly payments. Ranger fs a better bicycle than you can buy anywhe _ af any price. ires " horns, wheels, parts and pons eta at half usual prices. SEND NO MONEY, Simply write for our big, fllus- trated free Ranger catalog with lowest leapt and Cycle Company ‘i. 3,22: Mead i, H 109 cnieage tisk PROMPT USE HB MOTORS sASvery Cash or Easy Payments Sturdy ball bearing electric motors for actory, machine shop or garage. Am- ae capacity, smooth-running and eco

nomical. Reguire little or no attentio = to operate. nder absolute money back uarantee you run no risk. One to 10 -p. Choose the size ou weed. Ask for information on baitery chargers, lighting sets and generators e or wire today for information. HOBART BROTHERS CO., Box S-25, Troy, Ohio WITTE 2 H-P. Pulls 23 Big Value--Big Surplus power. Immediate shipment. Offer in- cludes engine on wkids--ready touse. From gy x! h add $5 Allsizes 2 to 8 H-E. | lower Now. WITTE ENGINE WORKS 2220 Oakland Ave. Kansas City, Me. 2220 Empire Bidg. Pittsburgh, Pa.

cash art ase : , Signments, mm! MAGAZINE lessons and i articles on Cartooning, Designing, Illus- trating, Lettering and Chalk-Talking. Criticises amateurs’ work. Full of in- formation for artists and art students. Satisfactory or money refunded. 20c a copy, $1 a year. Send $1 NOW, Thrift Stamos Taken G.H. LOCKWOOD, Editor, Dept. 638, Kalamazoo, Mich

—_ Bicycle a Motor Cycle By using the STEFFEY ATTACHMENT. In successful use 21 years. Easily attached to any ordinary bicycle, either diamond, double-bar or truss frame models. Lowe st prices. Send stamp for circul ars. STEFFEY MANUFACTURING CO. Dept. S, 5025 Brown Street, Philadelphia, Pa.

Correcting a Defect in an Automobile UTOMOBILE owners may gain a valuable suggestion from the description of the method I used in correcting a defect in the coupling of an automobile. The car was equipped with plain disk couplings with leather insert, which connected the generator with the pump on one hand and the magneto on the other. We found it practically impos- sible to keep the back lash out. There- upon we took two silent chain-gear wheels and cut these in two, placing

sawed in Silent chain-gear wheels, half and coupled by chain, corrected a defective coupling each half on its respective shaft and placed the chain around the two halves. The chain, after being con- nected, holds the two halves of the wheel together and acts (to some ex- tent) as a universal joint, at the same time making a much finer adjustment for the timing of the magneto. We have tried these couplings out for five thousand miles, and there is not the least bit of the lost motion that is usually to be found in other couplings.—H. R. SPENCER. Electric Wires Connected with a Cotter-Pin HERE electrical connections must be made and remade in wires carrying relatively small cur- rents, the ends of the wires may be slipped through the loop or eye of the cotter-pin—soldered and twisted to make good contact, and taped. Wire ends thus equipped may be quickly

Cotter-pins may be used for making wire connections attached to other wires, to binding- posts, or to each other by simply slip- ping the fork of the cotter-pin over the wire and sliding the washer forward to lock it. Wire ends so equipped may be used and reused without becoming frayed. 117 |

Big Money for Boys!

ELECTRICITY There is a wonderful opportu- nity right now for boys who like electricity. Thousands of men from the electrical industry have gone into the service. But their work must be done. Boys who are ambitious and will train themselves in spare time can step into good positions and get experience that will give them a real start toward success in life. Good salaries are offered with rapid promotion. For 29 years the International Correspondence Schools have been training boys for success in electricity and over 200 other sub- jects. They will help you prepare right at home for a position in the line of electrical werk you like best —or in any other work that ap- peals to you. Thousands of boys, through I. C. S. training, have stepped into fine jobs, but never were Opportunities so great as now. Let the I.C.S. help you. Choose the work you like best in the cou- pon below, then mark and mail it today. This doesn’t obligate you in the least, and it will bring you information that may start you on a successful career. This is your chance. Don’t letit slip by. Mark and mail this counon now ee eee ee eee TEAR OUT HERE com eee cee) ee oe INTERNATIONAL CORRESPONDENCE: SCHOOLS BOX 7612-B, SCRANTON, PA. Explain, without obligating me, how I can oe for the position, or in the subject, before which I mark X ELEOTRICAL ENGINEER (SALESMANSHIP Electric Lighting ana Kys. ADVERTISING _) Electric Wiring Window Trimmer _) Telegraph Engineer [})Show Card Writer Telephone Work Sign Painter MEOHANIOAL ENGINEER Railroad Trainman Mechanical Draftsman CJILLUSTRATING ) Machine Shop Practice |} Cartooning Toolmaker BUSINESS MANAGEMENT Gas Engine Operating [ } Private Secretary CIVIL ENGINEER f} BOOKKEEPER }Surveying and Mapping Stenographer ard Typlst MINE FOREMAN or ENGR _| Cert. Pub. Accountant STATIONARY ENGINEER Marine Engineer }Ship Draftsman ARCHITECT Contractor and Ballder Architectural Draftsman Concrete Builder Structural Engineer PLUMBING AND HEATING | )Sheet Metal Worker ™ Textile Overseer or Supt. Bo \HEMIST (_}) Mathematics TRAFFIC MANAGER (Railway Accountant Commercial Law “]GOOD ENGLISH 4 eacher _) Common School Subjects “]CIVIL SERVICE AR ailway Mail Clerk AUTOMOBILE OPERATING Auto Repairing Navigation (Spanish (J) AGRICULTURE Ef) French (J Poultry Raising §Jitallan

Name eieeiadnes Present Occupation. amit Street 8 = City. ee Canadians may send this coupon to -26-418 Internationul Correspondence Schools, Montreal, Canade .

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South Bend Lathes| A Size for Every Shop 9”x3’ Plain Feed, Automatic Feed, Price $175.00 Price $210.00 11”x3’ Plain Feed, Price $260.00 Automatic Feed, Price $300.00 9” and 11” South Bend Lathes are fit- ted with graduated Compound Rest and either Automatic Longitudinal Feed, Auto- matic Cross Feed or plain Screw Feed. They are practical in light Manufactur- ing, in the Tool Room, the Electrical Shop and Battery Service Station, or in any shop where fine accurate work is required. App Price ¢ Swing [Length [Distance Hole Wet F, 0. B. pees Over of Retweer Thru on | 8, Bend ? Be *Bed | Centers | Spindle | Skids Long Crated) Legs 25-AA 9% in 3ft 18 in & in 460 1$220.60 25-A | 9% in| 4ft 30 in & in 500 1$230.00 27-AA {11% in.| 3 ft 14 in | 4 in 575 1$300.00 27-A 11'4 in,| 4ft 26 in. | %4 in 625 {$310.00 27-B 1144 in.! 5 ft 38 in ¢ in 675 1$325.00 South Bend Lathe Works Established 1906 SOUTH BEND, IND. 433 E. Madison THE NEW METAL WORKER PATTERN BOOK. By W « KITTREDGE AND ASsOcIATES. The most complete book on metal pattern work published. It contains 259 problems, including 65 on triangulation. 544 pp., 900 figs. Price, $7.50 | Popular Science Monthly, 225 W. 39th St., New York : - H. i i 3 f Electricians’ Knife and Tweezers We can meet dealers’ demands at once and offer attractive quantity prices Write for description MATHIAS KLEIN & SONS, Mfrs. CANAL STA. 3, CHICAGO Popular Science Monthly Gunpowder for Removing Heavy Bolts ECENTLY a large manufactur- ing concern had occasion to dis- mantle a heavy gas-engine, having a flywheel some 30 ft. in diameter. The tearing down of the engines proceeded without unusual difficulty until the UB OF | FILLED WITH SOLID STEEL POW AEEL\ HR Buack POWDER CYLINDER TO Guns ras Cen, The gun for removing heavy bolts and the recoil cylinder are here shown in working position flywheel was reached. The sections of which the wheel was formed were separated, after some little difficulty, by heating the large keys which joined them until they expanded sufficiently to be driven out. But the real trouble was found in removing the hub-bolts of the wheel. These were 21% in. in diameter, and from 12 to 18 in. long. Many years of operation in a damp and dusty place had so cemented the bolts in place that they resisted the best efforts of a 30-ton jack which was provided for the purpose. After some delay, a 100-ton jack was obtained, and further attempts were made to dislodge some of the bolts by the use of the heavier jack in connection with The other piece of shafting shown in this picture was set up behind the gun to take the recoil, and the gun was set with its muzzle directly against one of the bolts to be blown out. In the first attempts the gun was loaded with dynamite, and a small section of shafting was used as a plug or “solid shot.’’ The result was that the first gun used was blown in two. One of the illustrations shows the re- mains of this exploded gun. (The fuse hole does not show, as it was in the half which was blown off.) It was also found that the use of the steel plug was impracticable, as it damaged the metal of the flywheel. Using the gun shown with a charge of black powder and no plug or shot whatever, all the bolts in the flywheel The further of the two cylinders is the gun which blew out the bolts; the nearer cylinder provided backing to take the recoil the 10-ton electric crane which formed part of the power-house equipment. Again failure resulted; a few of the bolts yielded, but the longer ones in the inner circle around the hub re- fused to budge. In the extremity, some bright ex- service man remembered the damage which can be done by the mortar type of artillery, and proceeded to build a gun. Obtaining a piece of the shaft- ing used in a similar engine, about 10 in. in diameter and 4 ft. long, he bored out a hole slightly larger than the di- ameter of the bolts and extending some distance inward from the center of one end of the steel cylinder. Near the end of the large hole, a small hole for a fuse was drilled in from the side. In one of the illustra- tions a sliver of wood is set upright in this fuse hole to show its position. 118 The use of dynamite in this gun blew it in two; to avoid this it was found necessary to use, instead, ordinary black powder hub were finally loosened to a point where they could be pulled out by the heavy jack; a few of the bolts were blown clear out by the force of the explosion. A few days’ work, guided by a little military experience, thus avoided the tedious and highly expen- sive alternative of drilling out the large bolts. You Can Render Drawing- Paper Transparent CONVENIENT method for ren- dering ordinary drawing-paper transparent for the purpose of making tracings, and of removing its trans- parency so as to restore its former appearance when the drawing is com- pleted, consists in dissolving a given quantity of castor-oil in one, two, or three volumes of absolute alcohol, according to the thickness of the paper; and applying it to the sheet by means of a sponge. The alcohol evaporates in a few minutes, and the tracing-paper is dry and ready for immediate use. The drawing or tracing can be made either with lead-pencil or india ink and the oil removed from the paper by im- mersing it in absolute alcohol, thus restoring its original appearance and opacity. The alcohol employed in removing the first oil is of course preserved for diluting the oil used in preparing the next sheet. The solutions should be kept in well- stoppered bottles to insure cleanliness. February I TWI Ree a Thi comp! giving factul use. Secre of the 10,00 Bes' Ab every of for! are nc Pop ~- ‘H N An por exp ove fro kin ap] Th ele

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February, 1921 TWENTIETH CENTURY Book of Recipes, Formulas and Processes This book of 800 pages is the most complete Book of Recipes ever published, giving thousands of recipes for the manu- facture of valuable articles for every-day use. Hints, Helps, Practical Ideas and Secret Processes covering every branch of the useful arts are given. 10,000 Practical Formulas—The Best Way to Make Everything A book to which you may turn with confi- dence that you will find what you are looking for. A mine of information, up-to-date in every respect. Contains an immense number of formulas that every one ought to have that found in any other work. Price $4.00 Popular Science Monthly 225 West 39th Street, New York are nc& How to Make Things Electrical An of popular book for the student this and entirely new edition experimenter. It shows how to make hundred things from a simple battery kinds of up-to-date appliances. electrical cell all apparatus and Over a to The man or boy who is interested in electricity can find no end of experi- bells, lights the a bit rusty on how ments with batteries, motors, dynamos, electric everything And who has grown electrical. householder to repair electrical devices about the house, garage and automobile will | find valuable pointers and a lot of | new ideas. Clear, concise directions and many | careful drawings make this book | easy to use and of definite value to the amateur. Published February, 1921 Price $2.50 Popular Science Monthly 225 West 39th Street. New York | | | nw How to Straighten a Bent Connecting-Rod NOME time ago a serious accident | in the engine-room of one of our | local cotton-mills caused the stoppage of the machinery and temporarily made the three thousand employees of | the mills idle. came obstructed and this caused the buckling of a large rod of great weight. 18 ft. long and near its middle, where it was bent, about 10 in. thick. straightening of the connecting-rod by machinery because the mills had no machinery of adequate size and power to do the work. The crosshead pin be- steel connecting- The rod was The question was out of the In the yard of the factory we built a forge from bricks, leaving a gap at one end to admit the connecting-rod. We built a great fire, loaded the con- necting-rod on a truck, rolled it to the forge, and placed it with the bent part in the fire. four hours later we took the rod out of the forge, placed one end of the rod on the ground, and lifted the other end with our yard derrick about 6 ft. from the ground. ‘The raised end of the Heated at the bend, the connecting- rod was dropped on the ties connecting-rod was held by a grass rope close to the end. We placed two railroad crossties on the ground be- neath the bend and with a steel hook slipped the rope off the end. Three falls of the rod, which had to be reheated twice, straightened the bend and, as there was fortunately no | torsion, the connecting-rod functioned properly when the engine was started next morning.—J. EDGAR MITCHELL. Temporary Patch for a Torn Automobile Top ERE is a good method for mend- ing a torn automobile top. Sew the torn edges of the tear together with stout thread. Then take several strips of surgeon’s tape and lay them over the joints, pressing the tape down solidly and warming it by the heat of the hand. When the tape is firmly stuck to the top, give it a couple of coats of shellac and allow it to dry thoroughly. Lastly, give the tape a coat of quick- | drying paint, the color of the top, and .the repair is completed. 119 REG. U.S. PAT. OFF, Pliers No. 50 No tool could be more house, garage or Office. useful around strong enough to stand hard use and ‘“‘made to make good.” Forged from tool steel (not pressed); spring tempered handles; throat shaped to be used as wrench; powerful knife cutters; knurled handles scientific shape. - 4 7 sice of a Retail price $1.75 for 6 inch. If not at your dealer’s, write to us direct. 'RedDeyil Nol239, Os. ll iat Our teeth One of a large assortment of Hack Saw Blades, each one made for a par- ticular class of work. Both hard and flexible blades, teeth cut—-not stamped and evenly set. The correct number of teeth to the inch, according to the work the blade will be required to do. Tool Booklet on request Smith & Hemenway Co., Inc. 264 Broadway, New York City Manufacturers of a complete line of Hand Tools for Mechanic, Electrician and Motorist. Pliers, Hack Saw Frames and Blades, Auger Bits, Chain Drill Glass Cutters, Cold Chisels, Punches, Lock Washers with six points of contact, etc., etc. \J 2 , ad ‘Devil’ TRADE MARK.

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Planes that inspire your confidence Sargent planes are not “Fair weather friends.” They cut through the toughest grains cleanly and truly, without a tremor. * tai Amateurs as well as | professional carpenters sense the correct ‘“‘feel’’ and “thang” of Sargent P| planes. The apprecia- | tion of good tools is in- stinctive. ey ist oe The Sargent Auto-set Bench Plane illustrated below deserves particu- lar attention. It is light, fast-cutting, and has positive adjustments. The auto-set feature en- ables the cutter to be removed, whetted and teplaced in exactly the same position without adjustment. Made in | Six sizes. te The Sargent book of planes will be sent free on request. SARGENT & COMPANY Hardware Manufacturers 50 Water St., New Haven Conn. ASBESTOS We are miners and shippers of Crude Asbestos in any quantity. We produce all grades at our world famous BELL ASBESTOS MINES, in Canada. We also card fibres, spin yarns, weave cloths, and make all sorts of Asbestos products. For anything you want in Asbestos, turn to KEASBEY & MATTISON COMPANY Dept. S-4. AMBLER, PENNA., U. S. A. Owners of the world’s largest Asbestos Mines rs Pilliod Vee TOOL -CASES EXCEL Machinists, Tool Makers and Carpenters find them most satisfactory im construction, appearance, service and price. Immediate shipment Booklet describing 20 styles on request. The Pilliod Lumber Co. Dept. A, Swanton, Ohio Popular Science Monthty An Electrical Automatic Recording Target By Clifford A. Butterworth HE con- struction of an electrical automatic re- cording target for a rifle-range is detailed in the accompanying illustrations. In operation, the spot where a bullet. strikes is instantly indicat- ed by the lighting of a lamp in a corresponding position ona signal-board, making it easy to correct the aim and keep account of the score at ranges at which the target cannot be easily seen. The target is composed of five rings, each of which is. divided into four sec- tions. Each section is fastened to two arms which swing on a pivot. The sectionis normally held out by a spring, but when a bullet strikes, it swings back under the impact, pushing in a switch plunger which closes the con- tacts on the back of the target panel, lighting a lamp on the signal-board. As the size of a target depends en- tirely upon the range at which it is to be used, this is left to the constructor. The dimen- Neaiameereek. ileleleum! sions given are fora target A approximately 8 in. in | diameter. Ifthetargetis | rm 7K increased in size to any hid great extent, the parts | #% must be made heavier in |“ order to have sufficient | strength. | In making the target a wood panel is first built up, being made about 16 in. square. To this is bolted an iron plate of the same size, 14 in thick. The screws that hold on the working parts can be tapped into the plate, or bolts can be used and run clear through the wood. The target rings are cut from 14-in plate, turned to size and then cut into sections. They are drilled and countersunk for the3 /16-in. bolts struction that fasten | SPACING them to the see arms. The out- side diameters of the rings are as follows: Outer ring, 814 in.; second ring, 614 in.; third ring, 414 jin.; fourth ring, 3 in.; fifth ring, 1°4 in; bull’s-eye, 34 in. The arms are shown in detail SWITCH PLUNGERS Shoot at the target and electric lamps will signal automatically where your bullet struck Detail of the con- target is shown here 2°*%6 BOLI * Va. a IN SS SPACER These cross-sections and diagrams of the different parts of the target will be of help to you in making such a target in Fig.1. The: are made of 3 1) by 34 in. flat iror They swing on 3g-in. pin. Th: spacing ring that keep the: the proper dis tance apart ar cut from 3¢-ir pipe. The swite plungers ar made of %-in steel rod. Th ring sections ar fastened to the arms as in Fig. 2 The spacers, which are place: between the sections and the arms, ca be cut from 14-in. pipe or washers ca: be used. The space between the ends of the bolts and the plate must not be more than 1% in. The arrangement of the bull’s-eye and the four sections around it is shown in Fig. 3. These five plungers are made of 4- instead of °¢-in. rod. The five small plates on the back of the panel which provide a bearing for the inner ends of the switch plungers are arranged as in Fig. 4. The holes in the panel must be large enough so that the plungers will not touch the wood, as they must work as easily as possible. The Id | best way to do is to mark the places for the plungers on the front plate, and after boring the holes in the wood and fastening the plates on the back, drill the plunger holes through both plates at once. This’ will insure perfect alinement. The arrangement of the contacts is also shown in Fig. 4, and an enlarged view of a con- tact strip in Fig. 5. The strip is placed so that a contact is made when the plunger has moved in about ly in. The wires from the target to the signal-board are connected as shown inthe wiring diagram. A wire is run from each contact to the ==} |= ||| =f|=| of the as 1% 4 s—F| *) = —lLy : STOP BAR “by lamp in the ¥ (2 ° s_"% A! corresponding wa _J ie | position on the PIN ) SUPPORT Rr signal - board. One battery wire makes connec- tion with all the lamps, and the other is con- nected with the plate on the target panel. Al- together there are 22 wires run- ning back from FIGS SECTION BB — Yg ROD Februa ry, This is an of a life-tir an autom of your ow territory,! required. without fa SPARK ting, wire bonds, wir Ilustrz America Make $15 Month Sm mall cas dy, dep car ac ity fe eqnivaient terms Ge and let us manent, business. thon HobartBroth Successful Harde A bool hardeniny llustratic POPULAI

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~ iY

February, 1921 | Don’t Freeze | ‘Burn Woo You must burn coal or wood. Coal is scarce and high ape Wood is plenti- ful Hg cheap. Geta WITTE Drag Saw. Cut your wood for almost nothing. You can get delivery if you buy now and the lowest “?

‘s tases Controlled. You Push. to Start—Pull to stop. Any speed you want in starting orstopping. A fast cutting out- fit with high power 4-cycle engine. Cuts much faster than former rigs. Cash or Easy Payments. Sold on lifetime guarantee, WITTE TREE SAW EQUIPMENT Latest Out—Most Practical—Costs Less Makes the Log Saw a Tree Saw. Quick change. $34.95 Extra. Cuts trees clear down. Only one rig to handle. Branch Buzz Saw for saw- ing top wood, only $23.50. Why Pay more? Write for Log and Tree Saw Catalog FREE, WITTE ENGINE Works 2223 Oakland Ave., Kansas City, Mo. 2223 Empire Bidg., Pittsburgh, Pa. ——o

YIUNLUTALUEUNUUUUULUUULULL ULL Mn $372 in 17 Days WM

Mr. C. J. Weeks, 2319 Lydia Ave., Jacksonville, Fla., easily made this money by selling Sparko-Gaps $100 in Less Than One Week Irving Laighton, Vineland, N. J., reaped this harvest by selling Sparko Gaps! George A. Norton, of Vernon, N. . earns big selling Sparko-Gaps! THREE Vf Se aS 7 - ae ~ i ae | *s Cx NEW MODELS oT ee “COLD Pipe Fending Ma bs A a sh, ch nes pat. electrically oper ( . Lu Dg aled to ber i tre ym 1 in BB to 8 i? west | - | inchée Send fc itec Ny ae WL = te i, We Send maufacrure TEN J r , other sizes, han erat to oo | b benc 4 ize, Bto 6 inches. FF OD escees x American Pipe Bending Machine Co.

electrical, rope, air- plane, piano, pipe- organ, flat, hoops, bale-ties, tacks Manufacturers—51 Pearl Street, BOSTON, Mass., U. S. A. nails, barbed-wire concrete re - inforce- IRE ment springs, net- ting. wire fences, steel posts, trolley-road wires, and rail bonds, wire wheels, auto-towing cables, horse-shoes illustrated Books Describing Uses. FREE F. Baackes.V. P. andG. S. A. American Steel & Wire Co. * Bs*ksy. Fz The Midget Slide Rule will instantly add, subtract, multiply and divide either whole numbers, dec imals, fractions or mixed numbers. It solves proportion and gives roots, pow ers, Sines, Tangents and Logs. The +‘! most ve orsatile eale ulatorever invented. Made of Metal. Size >rice with Instruction Back, $1.50. Satisfaction guaranteed. Send for our Catalorue and Instructions in Logarithms and Trigonometry. Gilson Slide Rule Co. Niles. Mich.

Make $150 to $350 Profit Every Month in Battery Charging Small cash payment brings you this sturdy, dependable HB Charger with capacity for 32 6-volt batteries or eqhivaient. Balance on easy monthly terms. Get our liberal proposition a i let us start you in this big, per- nent, profitable battery charging business. Write today for informa HobartBrothers Company, Box $23,Troy,0. Successful Manufacturers Sinee 1898 Hardening, Tempering, Annealing and Forging of Steel By J. V. Woodworth A book containing special directions for the successful harde ning and tempering of all steel tools. 320 pages, 250 fllustrations. Price $3.

POPULAR SCIENCE MONTHLY, 225 W. 39th St, New York

the target.

They can be bunched together like a cable and bound with tape every few feet. The signal system can be improved | by the maker if desired. ior example, the wires from the target, instead of being connected directly to the lamps, could be connected to electromagnets operating small switches, so that a lamp on the signal-board, instead of only flashing an instant, would remain

wh Sem Ho” nes +

Pe vas SPRING BRASS CONTACT Cece The complete wiring diagram of the target and the construction of the electric contacts are here shown

Ighted until the switch was released. It would also be possible to construct an automatic recorder with electro- magnetically controlled pencils to mark the score on paper moved by clockwork. Cutting Off the Bottom of a Bottle T is sometimes desirable, especially in a laboratory, to cut off the bot- tom of a bottle and to do so with a clean-cut fracture. The accompanying diagram shows a very effective method. Tightly draw about the bottom of the bottle a piece of No. 30 iron wire, carrying one end to one pole of a battery and the other end to one binding-post of a knife-switch. Do not allow the ends

on When the current is sent through the wire; its heat will cause the bottle to crack

to touch at the point on the glass where they cross, and draw them tightly. Connect the other binding- post of the switch and the battery with ordinary copper bell-wire. The source of current may be a dozen dry cells, or with a suitable re- sistance in series, current may be taken directly from the house-lighting cir- cuit. Upon closing the circuit, the | heat in the wire causes the glass of the | bottle to crack in a smooth line. 121

Economy and Drop-Forgings kK FORE shipment, every one of Williams’ Special Drop-Forgings, made to order, must pass the rigid inspection — of experienced men employed only on this work. When necessary, dividual forging eauged for thickness and length, straightened and tested for strength. <All are absolute- ly dependable and are fully guaranteed. each 1n- 1S The cheapest forgings in the long run are those made uniform in size and quality and close to specified di- mensions, thus saving customer's labor, tame, and money. J. H. WILLIAMS & GO. “The Drop-Forging People’ } the tools BUFFALO 7 VULCAN ST. BROOKLYN 7 RicHaArps St. CHICA 1007 W GO 120TH St.

WILLIAMS’ “AGRIPPA”’ TOOL HOLDERS For all regular machining operations Booklets describing Walliams’ Supertot Drop- Forged Wrenches, ‘‘ Vulcan’’ and ‘‘A grip- pa’ Tool Holders, Lathe Dogs, Clamps, et will be mailed free on your request.

Page 106

MONARC THES In the largest factories in the smallest machine shops— wherever lathes are used— Monarch Lathes are found. & SAY wedbdorg Built right of the very best material designed to meet all conditions in lathe work— Monarch Lathes deliver per- fect work of the most minute accuracy and give long time service. bd Moderately priced because they are built in quantity. Guaranteed to give satisfac- tion to the purchaser. Write today for catalog and full information of Monarch Lathes. The Monarch Machine Tool Co. 108 Oak Street Sidney, Ohio aot SERENE 8 BEE cE 8 . Nooden, Counter recording ° . machine production This shows a Veeder Counter recording the number of stampings produced by a punch press—counting ork as it’s done This enables the operator to 1ine close to capacity at the same ives and-counting weighing or computing roduct eeder Counters of similar type are 1 on screw machines, pri presses, pumps, eyors, stoker electric ers, coil winding nery, can making ac y. paper making hinery, textile machines, laundry machinery arking machines, bottling machines and scores of other Write w Veeder counter booklet and see hat it offers tor your purposes The Veeder Mfg. Co., 44 Sargeant St., Hartford, Conn. MOTORCYCLES, SIDE CARS AND CYCLE-CARS, Their Construction, Management and Repair. Victor W. Page Describes fuily all leading types of ma- chines. 550 pp., 350 iils., 5 folding plates Price, $2.50, POPULAR SCIENCE MONTHLY 225 West 39th Street New York By Popular Sctence Monthl,, Why Some Lathe-Work Is Inaccurate By Howard Greene F TEN the amateur mechanic finds that when a piece of turning is fin- | ished it is not as accurate as it should be, though the lathe may be of a good make, the tools in good order, and the actual turning carefully done. Per- haps the commonest fault found is | that, in the case of a shaft or other | and the work | recess gets larger, somewhat long piece, the diameter at the tailstock end will be greater than at the headstock end. The reason will be found in the fact that the cen- ter for the tail- stockend has not been properly prepared. A center-mark is made with a center-punch, the lathe center jabbed into it, proceeded with. As the work goes on, the center, finding itself ina place in which it does not fit, grad- ually wears itself into the metal. As the the shaft be- comes loose be- tweenthe centers Careful gaging will it is best to treat both ends the sam: way. Another cause of annoying inaccy racy in lathe-work is back-lash in t} cross-slide. If the work is done wit an eye wide open to this possibilit) trouble can be usually avoided. Fy instance, if the tool has been fed i; and the mechanic finds it has bes advanced too far and turns the hand] back a little, if he is not looking out the result may be a backward jum; until the back lash is taken u; and a consequen involuntary a! teration in th adjustment ox curs. The prope: way, under th circumstances, is to back off th: tool a little and then feed it uj; again so that there will alway: be pressure fron thescrew toresis' the pushfrom the tool. Watch an experienced lathe-hand and he will work thi way almost in- disclose inaccura- variably, con- and shifts away cies if the work is not properly centered stantly on his from the tool. Not only does it shift more and more as the work proceeds and the recess becomes larger, but the nearer the tool comes to the dead center, the greater is the movement. And if the mechanic, noticing the looseness, tightens up his back center, the resu!t will be a change in the cut unless the tightening is done between cuts. The proper thing to do is to prepare a proper center in the first place. Drill a small hole in the center of the shaft; 1/16 in. is a good size for small work. Drill it far enough so that the point of the center will not reach to the bottom. Then make the seat for the dead center with a regular centering tool or a drill ground to guard against trouble as a matter of fixed habit. Do not start a job without oil at the cutting-point and then later on start the oil running. It will alter the cut. On the other hand, if you start the oil, keep it up to the end of the cut. Uss the same cutting lubricant from one end of a cut to the other if accuracy is called for. It is a common thing to use a file smooth cut—for getting a smooth fin- ish on a rough-turned job. This is all right in some cases, but it is bad business unless accuracy is a minor consideration. It is practically im- possible to file evenly enough to avoid taking off more in one place than an- “| agoop other, and the work will CENTER the 60° angle of the cen- , be more or less out o! ter, or with an old center parallel and out of round with flutes cut on it as pL ee But if only finish is the shown in the illustration. Saat object, it will do wel This gives a bearing for >: enough. Never hold thi the center that will hold CENTER CUTTER file still while the wor the work properly, though A good center and runs under it. Keep | it is always well to try between cuts and see if any shake has developed. The small hole first drilled not only protects the point of the center, which should never touch the work, but also holds a little extra supply of oil for lubrication. While the centering of the other end one | of the work is not so important, be- | cause there is no relative movement there between the center and the work, gv = 4 the tool for cutting moving, not only across the work, but lengthwise or you will get scratches and groove: and the file will get its teeth filled uj very rapidly. Inrome work a ver, fine finish can be obtained by using : bit of oilstone and oi! on the surface The amateur working on the lath should always bear in mind that accu- racy isthe most important thing and fine finish is of on'y secondary consideration. Februar Increé “HE 34 creased marring holes as draw ing the ion§ Whe1 A » Mark thus much distane it will I betwee! scale m rectang the gui of blocl upper ¢ For Bez N sn wrig is quite lowed tion. with gr tration, able ler A sn into th Throug a diame date a Oil ye well troubl the frie copper shaft a warms to alloy bearing comes t ing. T shaft, d

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February, 1921 Increasing the Usefulness of the Triangle *HE usefulness of a triangle such as ; used by draftsmen may be in- .d by a simple method without creast marring it in any way. Drill 3 small holes as indicated in the accompanying drawing about 14 in. from the edge of the longer right-angle side. When you wish to do some lettering, you can draw guide-lines by placing the point of the pencil successively into the 3 holes and drawing the lines by sliding the short side of the triangle along the edge of the Cy / eer T-square. With- SAY 14. ); out any measur- ald \ i 5 are s e 2 ing the size of Mark your triangle the lettering will thus if you do be uniform. much lettering If you mark out the proper distance, and draw a line as shown at A, it will help you to get uniform spacing between the lines of the lettering. The scale marked at the short edge of the rectangle will enable you to mark off the guide-points for the vertical lines of block letters as shown at D in the upper corner.—J. H. MOORE. For Oiling Line-Shafting Bearings Automatically N small workshops where no mill- wright is employed, line-shafting is quite frequently neglected and al- lowed to go without proper lubrica- | tion. If the bearings are equipped with grease-cups, as shown in the illus- tration, they will run for a consider- able length of time without attention. A small length of rattan is driven into the nipple of the cup as shown. Through its center is drilled a hole of 2 diameter large enough to accommo- date a piece of copper wire and leave a small clear- ance. A _ piece of copper wire is placed as shown, one end touching the shaft, the other protruding into the grease- cup. The grease- cup is filled in the usual way. As the bearing warms up with the friction of the shaft’s turning, the copper wire, being in contact with the shaft and a good conductor of heat, warms the hard oil in the cup enough to allow some of it to flow down to the bearing. The warmer the shaft be- comes the more oil is fed to the bear- ing. The wire, being softer than the shaft, does not scratch or cut the shaft. Oil your bearings * well and _ avoid trouble 40 Years of Progress with Fine Tools «--cyvhen old Dobbin zvas the motor.” Even in 1880, in the days when old Dobbin was the motor, machinists had learned to rely on Star- rett Tools for long service and measurements of un- varying accuracy. So the first automobile factories to be established found skilled workmen ready to carry out the inventors’ plans— with the help of Starrett Tools. Starrett Tools are linked inseparably with the marvelous growth of the automobile industry.. They have helped to make it possible. In the great automobile factories of today—in every shop where metal is worked to the closest limits of tolerance~skilled mechanics know and prefer Starrett Tools. The Starrett Catalog No, 22“W” {sa useful reference book. Write for a free copy. THE L. S. STARRETT COMPANY The World's Greatest Toolmakers Manufacturers of Hack Saws Unexcelled- ATHOL, MASS, y TURNER ” MACHINE SHOP WORK. 'B PERRIGQ e ° ZRIGQ, Do You W ork Ina Factor y 2 | FAIRFIELD. \ compre e guide to the most | approve wd methods in m 10de rn shop practice. The use $10 to $25 a Week for an Hour a Day io of v ariou ul i tec Is is exp lained, folk »ywed by a com- We want a representative in every factory in the United prehensive disciusion of the lath® and lathe tools, States. You can easily earn $10 to $25 extra each week by 360 101 uy , wad iil P $2 60. using an hour a day of your spare time Write to-day giving v0" pp. aceU rice, $2. the name of the factory where you are employed. POPULAR SCIENCE MONTHLY, 225 W. 39th St., New York POPULAR SCIENCE MONTHLY 225 W. 39th Street, New York FACTORY GUARANTEED ALL SIZES PROMPT DELIVERY Polyphase Motors Direct Current Motors Single Phase Motors Zand 3 plase, A.C. 220 v, 110 or 220 volts, D. C., shunt wound, 110-220 volts, A. C., 60 cycle, Ge..1750 R.P.M., Complete 1750 R. P.M. With base pulley and ee with base and pulley. Ts — / Vioshiog Machine Mone $28.50 ”% OP. - $46.50 1/4 Mosinee - $28-50 V/q vase H.P., 110. agen $28.50 wade nl 1 wpe. - $66- 50 1/4 ing Machine Mote $28 50 1 9 ht i. re tateaten, tal . $46 50 ——— Tour. . - $58.50 ; bu toene.,--Sane *** - $9650 Vr ur. - - $89.50 Wy MPa tates $54 50 15v.,10amp $26.50 34° - $98.50 so | oe omnes, $7450 40 v, 6 amp. - - $31.50 5 “ape $ 50 20 ane $124. 2 eT sapshien infection 50 - $116: “ $126- 110v, 2% amp. $31.50 | 3up.-- $142 ner 110 v, 5 amp. - - $52.50 wd Btn $106. 50 Sup. - - $218-50 g bait $146.50 40v, 12 amp. -- $52.50 WRITE FOR CATALOG. SARGAINS IN sesememmmnee” with sliding base $188.50 110 v, 91/5 amp. pogo 1 Ta AL WASHING MACHINE MOTORS 40 v, 25 amp. - - A 110 volts 110v,18amp. $116.50 Yaw Pas ine 3? 17588 8PM, £o. 40 v.,50amp. $1 16.50 — 110v,26amp. $156.50 110v,50amp. $238. 50 Genoaier 38 $1 16.50 MONEY BACK SHIPPING TERDAS: Espace Sign eon win oi of Losing stoced by iit MANUFACTURERS’ DISTRIBUTER CHAS. H. JOHNSTON, Box 14, West End, Pittsburgh, Pa.

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Your Success depends not your technical equip- ment but on your every day working ment. on!y on equip- Your tool kit should contain enough too!s to meet your every day requirements so _ thai you can work accu- rately and quickly, these two points are the basis for promotion in practically every shop. A well made re- liable mi- crometer is an ac- tual ne- cessity. Its uses are unlimited. It should be in every kit. Another practical tool is the combination square. In laying out a drill job or squaring up a piece it is of great help. If you have many jobs that demand ac- curacy a Vernier Cali- per will be of great assistance. rn There are over a thousand other tools a4 that made to aid the have been machinist, iisted in our No. 28 Catalog. Send for it Brown & Sharpe Mfg. Co. PROVIDENCE, R. 1., U. S. A. Popular Science Month, Gymnastic Apparatus for Your Yard By Walter S. HE apparatus shown in the illus- tration comprises the horizontal bar, flying rings, trapeze, and a child’s swing, while rope-climbing can also be practised upon it. The uprights are two scantlings 2 in. | thick by 4 in. in width and 15 ft. long. The crosspiece at the top is a piece of the same material 414 ft. long. These can be purchased in a lumber-yard. Put the scantlings together with the 2-in. sides facing each other. Then measure up 3 ft. from one end and mark with a pencil. This length goes into the ground. Measure up 6 ft. from the 3-ft. mark and mark again. Now mark every 6 in. for a distance of 2 ft. each side of the 6-ft. mark. These are for the holes which the hori- zontal bar slips through. Thentake a brace and bit ~.«+——, i en J. Thompson put 4 in. of it in the bottom of the hx then set the scantlings in place and the concrete around them. Keep the secantlings vertical by stays while the concrete is soft. It will take abou: a month for the concrete to harden, diir- ing which time the scantlings must not be touched. A piece of oak pole 414 ft. long and 114 in. in diameter is best for the hori- zontal bar. Run the bar through the lowest hole in one scantling and through the corresponding hole in the other scantling, and if the bar is not even with the outside of each scant- ling, it should be sawed off so it will be. Take a bit 114 in. in diameter and shove it through the small hole in the seantling and bore a hole through the horizontal bar. by sure to hold the bit horizontal or else it and bore a hole 1°% fl in. in diameter in the middle of the scantling at every 6-in. mark. Then turn the scantlings so the 4-in. sides are together and inthe _| ¢& pao foe See Se ‘3 Stl =: i+ roster © G oO i y “ will not come out through the hole in the other scantling. Now purchase 2 bolts 41% in. long: these are to ¢ through the sm: hole in theseantli TIT tT a sar |La (Ges EES. | | iH 4 i ] U | aes i 2, — middle of the 2-in. side on both scant- | [ lings, draw a line | FFP fromthe first hole to the last and borea | 1,-in. hole all the | my way through the | A seantling so it will | pierce the center of | every Do this till every hole is pierced. This is for the bolt that holds the horizontal bar in its place. Now place them on the ground 4 ft. 2 in. apart, resting on the 2-in. side. They are now ready for the crosspiece at the top. It is well to have the ground ends resting against a wall or block of wood so they will not move when the crosspiece is nailed on. Put two large hook-bo!ts in the crosspiece with the hook end extending from the 4-in. side, 12 in. from each end. These are for the trapeze ropes. Place an- other one in the center of the same | side to be used for rope-climbing. Nail | the crosspiece to the tops of the scant- lings. Now give the whole structure a coat of white lead and two or three coats of any color paint desired. While the paint is drying, select the spot where you wish to erect the apparatus, but be sure you have room enough for the trapeze and swing. Dig two square | holes 114 ft. square and 3 ft. 4 in. deep. | The seantlings should be in the center of the holes and there should be 4 ft. 2 in. between them When the paint is dry, mix the con- crete. One part cement, 2 parts sand, and 3 parts stone. Mix it thinly and 124 large hole. 1 Why not erect a combination apparatus like this in your back yard? ldjj « J bbs U and in the ho zontal bar to kee; it firm while it being used. The trapeze-bar is made from the same material as the horizontal bar, but it should be 34 in.long. Bore two holes 11% in. from eachend. Purchase two bolts like those shown. Run these through the holes and tighten the nuts. It is well to wire the bar each side of the bolt with copper wire to prevent the bar from splitting. Now purchase a piece of manila rope 14 ft. long. Cut it in two equal parts. Now buy two safety- hooks such as shown in the i!lustration, pass one end of the rope through and splice the rope for a distance of 6 in. Then wind it tightly with strong fish- ing-cord. Do the same to the other hook. - The other end of the rope is passed through a ring and weund. The seat for the swing is the same length as the trapeze-bar and about 1 in. thick by 8 to 10 in. wide. Nail two cleats, one on each side of the seat, as shown in the illustration. Bore a hole at each end fora bolt. The sai kind of a bolt is used as was used the trapeze-bar. >» Thee q . Pr Magen SS ye ; Si St SiSiS SiSies fee Ss SSS SSS The rings can be purchased in a sporting-goods store for about one dollar apiece; the rope may be ob- tained at any hardware store. Instead of having an extra piece rope for rope-climbing, the two shor lengths can be joined together, thu reaching the ground. ct eh wm Februa Me NM SA A be and tw Proc about | long, t other, each tu edge, | board ¢ with g shoulde - OBJECTIVE COVER | Sol SPRING ss a me Fron lense with a for the made | over th cut in used in a cone: Blae possibl and tu The upon t pair of you ju Give ing of : weathe By | them t quickh A |} You “VE ud in it in o ably n and | HARNES: SNAP BAT Make with tk suffiei weigh make: the he tery a or mo Popular Science Monti,|;, Februar.

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February, 1921 Mailing-Tubes Used in Making a Spy-Glass SATISFACTORY sgpy-glass can A be made of two mailing-tubes and two lenses in a short time. Procure two ordinary mailing-tubes about 114 in. in diameter and 15 in. long, that will slide, one within the other, fairly snugly. In one end of each tube, about 1 in. back from the edge, put a shoulder of thick carc- board around on the inside, fastening with glue. Set a lens against this shoulder and then hold it in place OBJECTIVE END COVER fe _— MAILING 18 | TUBES \| 9X We ue CONCAVE LENS) | SHOULDER / SPRING RING/ \ CONVEX LENS SHOULDER SPRING RING From two mailing-tubes and a set of lenses a good telescope may be made with a ring of spring wire. A cover for the end of the tube should then be made of a tin-can cover that slips over the end of the tube and has a hole | A convex lens is | cut in the center. used in the objective or large tube and | a concave lens in the smaller one. Blacken the inside of the tubes if possible with a mixture of lamp-black and turpentine. The length of the tubes depends upon the combined focal length of the pair of lenses, but any optician will tell you just what lenses to buy. Give the outside of the tubes a coat- ing of shellac to protect them from the weather and your spy-glass is done. By extending the tubes or pushing them together the proper focus can be quickly obtained.—L. B. ROBBINS. A Homemade Handle for Your Automobile Battery “VERY one using a storage battery 4 in his automobile will have to lift | it in or out occasionally. This invari- ably necessitates the use of both hands and considerable exertion, as the battery case is bulky, heavy, yr and hardto handle. A very useful device for lift- ing the battery can be made by fastening a har- BATTERY ness snap with Make your work easier with this battery handle end of a stout leather strap of sufficient strength to support the weight of the battery. Such a handle makes it much safer and easier to move the heavy weight, and insures the bat- tery against injury due to breaking one or more jars.—RONALD L. PRINDLE. February, 1921 rivets to each | Friction Clutch | Starts and Stops Saw! xtCords a a Day! -7» Used by U.S. . Navy and in Gov’t V\Schools Ve Pat. Appld. For a ny 4G Less Than Wholesale! | Lowest Factory Price! Send at once for Special Offer and Lowest Factory Price on Improved 1921 Model OTTAWA Log Saw. Less than Wholesale! Don’t delay! No need to saw logs the old, back-breaking way when you can getan OTTAWA at Less than Wholesale. Just send name and address on coupon below for full particulars about this wonderfu] work-saver and money-maker— OTTAWA [OG SAW Cuts Down Trees—Saws Logs By Power The new Improved 1921 Model = Pulls Over 4 Hi P. OTTAWA cuts much faster than other oe Drag 7 —— Saws. a ey ad —— a a Minute—over 6 each secon cighs un less than any other 4-cycle log saw built, Easiest Friction Clutch to move and operate, Counter Balanced Crank levercontrolled, roller bear- Shaft eliminates vibration, increases power, saves ing, enables youtostartand fuel. Direct gear drives saw; no chains to tighten; stop saw blade without no keys; noset screws. 4-Cycle Frost Proof En- stopping the engine. gine. Built-in Magneto—no batteries needed. Saves time; pro- Automatic Governor with Speed Regular. When vides absolute not sawing, engine runs pumps, feed grinder, etc. safety. 30 Days Trial Every OTTAWA shipped on 80 daystrial. Must ful- fill 10-Year OTTAWA Guar- antee. For nearly 20 years we have been selling direct from factory to users, saving them thousands and thousands of doilars. Cash or Easy Payments Get our easy selling pian and learn how easy it is toown an OTTA- WA Log Saw. Pays foritself in a few weeks, then keeps on making money for you. Sold only direct from factory to you at Less than Wholesale Prices, Now over 15,000 satisfied users, Send For Free Book! Webave pre- pared a 32-pg. book which you may have free, Illustrates in full color the OTTAWA Log Saw, taken from genuine photographs, Be sure to write today so you will receive your copy promptly. Just send name and Wheels Like a Barrow Easy to Move from Cut to Cut Wheels Tura On Swivel Axte You can only get the OTTAWA Log Saw direct from the fac- tory, and at the Low Facto Price. You can’t get an O TAWA in any other way. Now over 15,000 satisfied users and ever is a b e address on the coupon opposite. aM | L T H is NOW - OTTAWA MFG. CO. Ben tine 8 1803 Wood Street Without obligation to on on ~ase send 3 me your Free Book and pbec cial Offer on the 1921 OTTAWA Log Saw @ NAME _ ’ # ADDRESS __ ja g auamunmeaemeeeeeecel OTTAWA, KANSAS This book includes electro-deposition of metals, electro-de- UP-TO-DATE ELECTRO-PLATING HANDBOOK | BUILDING AND FLYING AN AEROPLANE position of alloys, electro-plating dynamos, solutions and fe te nog ge Al HAT WARS. Pe pent Ager yr apparatus. 192 Pages, 50 Illustrations. With Tables and planes Spe Bc pment a i. pera Formulas. Price, $1.25. — ov pager Fico, 9F.00. Popular Science Monthly, 225 West 39th Street, New York Popular Science Monthly, 225 West 39th Street, New York | RULES [UFKIN 0 RELIABLE, STANDARD FOR YEARS PIONEERS IN THE NOTEWORTHY IMPROVEMENTS Stocked by Dealers. Send to us for Catalog No. 12 THE [UFKIN fouLe C¢: Saginaw, Mich. Get Your Free Copy Today of the most practical, complete and indispens- able monthly magazine for automobile owners, repairmen and garagemen It contains a wealth of invaluable information and suggestions on overhauling, ig- nition trouble, carburetor efficiency, engine knoc ks, wiring, storage bat- teries simplifie -d and many articles of interest to you. Attractive il- lustrations, drawings and sketches. Simply send your address TODAY and YOUR FREE COPY will be mailed at once. American Automobile Digest 105 Butler Blidg., Cincinnati

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Our new trade mark! =l5 Two Great National Industries Unite in Producing the Finest in Wrought Steel Hardware and Carpenters’ Tools ECOME products. acquainted with these dependabie STANLEY Wrought Steel Butts, Hinges, Drawer Pulls, Bolts, Brackets, Screen and Garage Hardware, will be a constant source of sat- isfaction Any architect is glad to specify them. STANLEY Carpenters’ ‘Tools are first in the minds of good carpenters. The ownership of a STANLEY Hammer, Screw Driver, Plane, Rule, Level and Bit Brace will afford you many pleasing, profitable hours. Catalogs Another STANLE} Hardware; ask your of the above products on request. product 1s Storm Sash dealer to show it to you. Or, tf more convenient, write us for folder 7B. The STANLEY WORKS Main offices and plants: NEW BRITAIN, CONN. Branch offices: New York Chicago Los Angeles Seattle San Francisco 126 / Popular Science Monti:!, A Wrench that Is Made of Seamless Tubing SOCKET-WRENCH is alway handy tool about a shop or , rage, and at times it is indispensa!| One that fulfills all the requirem: of the purchased tool can be m: easily. The wrench shown in the j!lust tion was made to fit the head of a in. standard cap-screw with hexa; head. A piece of -in. seamless tuh- | SEAMLESS U-™ | TUBING | ae Key-wrenches are easily made of seamless tubing ing was procured and the head of an old cap-screw ground to ataper. The end of the tubing was then heated and forced on the head. After heating again, the socket end of the tubing was forged about the head of a 3¢-in. eap- screw. The shank end of the wrench was drilled for a piece of 14-in. drill- rod, which was used as a handle. By using various sizes of tubing, complete set of wrenches may be mac: for either hexagonal or square heads. The, shanks may be forged to fit handle which is interchangeable with the complete set. If there is no seam- less tubing to be had, iron pipe may be substituted, although it does not have the lasting qualities of the tub- ing.—LOWELL R. BUTCHER. To Make a Cement Bumper : for the Garage O prevent running the automobil: > § through the back of aclosed garage, ‘4 cement bumper can be built either syhen building the drive and cement floor or years later. This is done by) “making a hill of cement about 16 in. high and starting the incline about 3 fte from the wall. Before constructing, examine the Yront-end of the automobile to se * SOLID CONCRETE «& SWINGS A a —-9: Solid ‘concrete makes a good bum- per for the rear of your garage whether or not it carries a bumper an how high the hill should be built 1 leave clearance for any front appliance that may be added. The hill should b made just abrupt enough that in th: event of the automobile’s starting t ascend, it would be met by such resistance as to cause it to roll back ward.—J. ALEXANDER. February, ) yor D new: the plate | tells how cells to de of about The cc cigal -box part ment strips 5, 1 wide, res run from edge. T 13,-in. le quired. with a m One si moved. nailed ti box and paraffin, soft are | the long brads; 1 place. 1] removed Melted p to a dep bottoms the strips the joint hot iron The e the cells telephon series, @ into ad whether move ar iron as b To as No. 6 dr “VER 4 pri guides, | to own costs co The how a with on convert: factory bit as g the exp The « the oth time al guides { pincers assists place, holds t moved torch fi stove p remove amoun'

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February, 1921 Constructing a High-Voltage “B” Battery ) you want to make an easily re- D newable and cheap battery for the plate circuit of your audion? This tells how the writer constructed dry- cells to deliver 32 volts, at a total cost of about 50 cents. The container was made from a cigar-box partitioned off into 24 com- partments by means of hardwood strips 5, 16 in. thick and 7¢ and 1%, in. wide, respectively. The wide strips run from end to end of the box laid on edge. The narrow strips are cut into 13,-in. lengths, 20 of them being re- quired. The ends must be cut square with a miter-box. One side of the cigar-box is re- moved. The remaining corners are nailed tight with *¢-in. brads. The box and strips are then boiled in paraffin, and while the paraffin is still soft are assembled in the box. Only the longer strips are fastened with brads; the others are wedged into place. The side of the box that was removed is now nailed in _ place. Melted paraffin is poured into the cells to a depth of 14 in. This seals the bottoms of the cells and helps retain the strips. Any cracks that appear at the joints can be sealed by passing a hot iron over them. The container is then tested. the cells with salty water. Connect a telephone receiver and battery in series, and dip the ends of the leads into adjoining cells to determine whether there is a leakage. To re- move any short circuits use the hot iron as before. To assemble the cells, take a new No. 6 dry-cell, cut off its zine shell and How to Make a rill “VERY fisherman takes particular pride in his pole with agate line- guides, ete., if he is fortunate enough toown one. But a pole so equipped costs considerable money. The illustration clearly illustrates how a cheap fishing-pole, equipped with only simple wire guides, may be converted into an efficient and satis- factory pole with guides that are every bit as good and work just as well as the expensive pole. The operation of converting one to the other is simple, but takes a little time and patience. To remove the guides from the old pole take a pair of pincers and unwrap the wire which assists in holding the wire guide in Place. If the solder that is left still holds the guide firmly, it can be re- moved by placing the guide over a torch flame, or even an ordinary gas- stove plate will do. Be careful not to Tfemove too much of the solder, as the amount which is left will serve as the By Thomas W. Benson PARTITION ; ZINC CARBON P t+ PARAFFIN pat t- SAND SGV Nt CARBON ROD - BATTERY PASTE i i LS PZe cece f~ ZINC PLATE ™ PARAFFIN CROSS-SECTION OF ONE CELL IN COMPLETED BATTERY It costs very little to make a high-volt- age battery like that described here remove the black substance inside. Add to it half as much flour and sufficient 10-per-cent sulphuric-acid solution to make a thick paste. The zinc shell is flattened out and cleaned with sandpaper. It is then cut into 24 pieces measuring 34 by 2in. The corners of these pieces can be trimmed off as shown, if desired. For the carbon elements use sticks 2in. long and 44 or 1% in. in diameter. These can be obtained from old pocket-light batteries or from the B batteries at present on the market. They have brass caps fitted, and serve the purpose nicely. The prepared mixture is distributed evenly among the cells, taking care that none gets on the top of the partitions. Put a carbon stick and a zinc sheet in each cell. The zines, however, are wrapped in porous paper toweling or filter paper for 115 in. of their length. Double a piece of paper 3 by 2 in. the long way, insert the zine between the folds, and turn back the ends. The zinc can then be pushed into place. The wrapping prevents local action of the zinc. Each cell gives about 1.3 volts. On circuit it will give 0.5 ampere. When the elements are placed, cover the paste with clean sand nearly to the top of the partitions and pour in paraffin to cover the cells and parti- tions. After the paraffin has har- dened, the cells are connected in series by short soldered leads from the zine of one cell to the carbon of the next. Bring out leads as desired. When the connections are completed, more par- affin may be poured in. The box may be painted and the lid replaced to give it a finished appearance. Should the voltage drop off after several months, it may be brought back temporarily by inserting a heated nail through the top paraffin and injecting a solution of sulphuric acid. When finally worn out, the battery may be completely rebuilt from one No. 6 dry-cell. Simply disconnect the zinc terminals and pull out all the electrodes with a pair of pliers after warming the battery slightly. Scrape out the paraffin and remove the dried paste. The new paste may be put in, the old carbons used again, and new zinc sheets inserted. The paraffin may be melted over and. used again. The cost of making and maintaining such a battery is extremely small. short Good Fishing-Pole from a Cheap One By Frank W. Harth tinned surface to which to solder the new guides. The new guides, instead of being made from expensive agate, are turned from scrap ivory knobs taken from an old electric instrument. figure 1 shows how the guides were made. A lathe is not at all necessary, in fact, a good knife and file are all the tools that were used. 7 WIST WIRE AND SOLDER POLE Pe - GROOVE DRILL & SHAPE FIG. | RUN WIRE THRU ett) 1'P sas BEND OLD f “0p TIP SO THAT | i oy GUIDE WILL SET/ | FIRMLY FIG. 2 FIG.3 Details of the accessories required for converting the cheap pole into a high- class one 127 The guide-holders are made from paper-fasteners straightened out, wrapped once around the groove in the guide, and then twisted, leaving two ends for soldering. Figure 2 shows the holder loop in detail. By holding the wire in place on the pole with a pair of pliers, one end can be soldered into place. After one side is soldered, the finishing of the other side is a simple matter. The super- fluous lead is then trimmed off with a knife and file. The tip was made in the same way, except that the other end of the knob was used. Figure 3 shows how the tip was fastened and then soldered into place. It is not necessary to wrap the wire on again, as the guides will hold just as well. The rebuilt pole, although not as fancy as a professionally made pole, looks fairly well and, what is more, works just as well.

Page 112

Drawing on 5 tee fungus is a form of plant life with the uses of which compara- tively few people are acquainted. One class, popularly called shelf or bracket fungus, may be used for decorative purposes. Pictures may be drawn on its flat surface. The bracket fungus is found most often in the shape of a semicircular bracket, varying in size from 1 in. to 2 ft. in diameter and attached to dead stumps and fallen logs—beech-trees particularly. One side, the upper, is a hard woody surface, brown in color, with concentric rings similar to the year-rings of a tree. The under side in most specimens is a pure white which, on the slightest rub, becomes a sepia brown. It is this side on which the artist can work. In fungus-hunting, which is fun in itself, the artist needs but few materi- als—a chisel to pry off the brackets, 2

aoe S wean | The largest and whitest fungi may be found in the thickest and darkest woods hammer, and some receptacle to hold the specimens so that their sensitive white surfaces do not rub or touch one another. A box with several shelves and a handle for carrying will answer. To obtain good, untarnished fungi, it is necessary when chiseling them from the log or stump to make sure that the bracket comes off without breaking and without falling to the ground. If this should happen, as is sometimes the case, and it falls on its white face, the specimen is spoiled. Having a few good specimens, the artist is ready for his work. A simple set of tools is now necessary, consisting of three or four sticks sharpened to various degrees of fineness and a clean rag. A stylus and the file blade of a pocket-knife are even better than the sticks. One of the sticks should be sharpened to a flat chisel point, which tool can be used to secure background and shadow effects. When the artist has determined on his sketch, a portrait, landscape, build- ing, or a copy of a picture, he must remember that a mark once placed upon the fungus cannot be erased. A misplaced line or badly proportioned object cannot be rectified. The reason for this is simple The Popular Science Monthly Fungus—a Novel and Pleasing Art By Anthony E. Zipprich

Highly pleasing artistic effects may be produced by etching portraits on fungi “etching side’’ of a fungus, when freshly picked, is very slightly moist and pure white. This white surface, however, is only about as thick as paper. Directly beneath it is the body of the bracket, a rich deep brown, ex- actly the color of the photogravure pictures in many Sunday newspapers. The scratch of a pin or the cut of a knife will expose this beautifu] brown underneath, leaving a permanent mark. The exactitude required is precisely what fascinates and makes the alluring. An artist in making his first attempt will do well not to block in his subject, but rather to make small dots on the white surface at important parts of his composition, which points can then be connected. The proportions and outlines are then sure to be correct and true in perspective. The tech- nique of the artist and his method of handling will be greatly enhanced in consequence. To keep the lines of the subject clean and sharp, a linen rag should be along- side of the worker. In the process of etching, the tool gathers up small parts of the white material, and as a crisp, sharp line is hard to get with a clogged seriber, it must be-wiped on the cloth after every line. When this is done, no art

The velvety white under side of the fungus offers an exccilent medium for the artist’s stylus

128

specks or crumbs stick to the pict:r and the results are more satisfactor Fungus etching will give keen delice}: to any individual skilled in the us the pen or engraving tool. It has, or may seem to have, serious drawba when one is not well acquainted w th its peculiarities. One of these draw- backs is the tendency of the fungu dry up and become unworkable, som times within twenty-four hours. How- ever, a dried shelf or bracket can be put in working condition by placing it in a damp atmosphere overnight or by hanging a damp rag over it. The time required for this varies and i; only learned by experience. The tendency of fungi to dry and be- come hard should be kept in mind and only so many brackets should be col- lected as an artist can conveniently etch in the course of one day. A second and also a serious difficulty relates to the color of the working side of a bracket. The finest and whitest specimens are found in the deepest woods where little or no sunlight pene- trates. When they are brought out in the daylight, some turn a light brown or pink after several days. To prev: or lessen this, they should be etched only in subdued light, or, if this is not feasible, they should be left in the sun

Great care must be exercised to prevent the fungi from be- coming marred by scratches no longer than the time required to finish the sketch. With the picture completed and the fungus dried up, the tendency to ‘‘yellow” will be largel) lessened. As stated at the beginning of this article, effects like the mezzotints of the old English masters can be secured; wood-engraving and charcoal studies likewise have their counterparts in the fungus medium. The water-colorist will find the white surface of hard and dry unused fungus a very fine medium for his brush. While the writer has never attempted oil-painting on them, it is within the range of possibility th this form of the graphic arts can also be successfully applied to fungi, bi etching seems, after all, the most log- ical and appropriate method of utiliz- ing fungi for artistic purposes.

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Page 113

thly be it by ‘he nd ol- Lly ity de Popular Science Monthly a = TYYYTIVYYITITITIVITINITIIIYITIVITIVIVILILIIIII IVI IVI TIVITIES bene nes TYTITYITIYIVITITYYYITITIVITIIIIIIII IIIT IIIT ITIP Y ILI PEST EEE PE EO Ur Sh ee Se ek ek 2 OS OS ON SE SD So SS Tre RS TE OTST TTT TET TTT TTY DMT | OSSD Sos) St) SD SO SOS OSNGN GS ONO NS SOS SO SOS SOS GSTS = SRIETRN SNE RN SRN ERS 2 SOS OS ON ON GS ——— 1" 3 The true portrait of Caruso’s art TOT » Enrico Caruso 88127 he, ee ey EN, ~ ‘ ‘King, at. COn€ 5 q ¥ TUTTE TO When you hear a Victor Record of Caruso’s voice played on the Victrola, you hear the great tenor exactly as he wishes you to hear him. NIE Only the Victor process of reproduction can HE EL bring out all the wonderful beauty of tone IE Eb which the Victor process of recording put into | the record. After their records have passed the critical EY, officials of the Victor Recording Laboratory, Eh the great artists who make Victor Records pass l judgment upon themselves as they are heard ¢ on the Victrola and they must give the final | ; approval before any of their records are re- . ¢ leased to the public. Victrolas $25 to $1500. | : : iE f Victor dealers everywhere. aes. i 7 . word “'Vietrola’* identify all our products 1 (| = Victor Talking MachineCo.,camden, NJ. Hekanierte a "Lick on eins ee a ae | cereal iE (Ean ans guevuuna cco LTTE = = sais en — amon onenneana SR T ~~ — a a 1

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Popular Sc:ence Monthly

Science Monthly Volume 98-No. 3

‘ =. Popular MARCH, 1921.

Important to Readers Owing to the paper short- age, the number of printed copies of POPULAR SCIENCE MONTHLY is limited. To insure getting your maga- zine regularly, you should place a standing order with your newsdealer, or send us your yearly subscription of $3.00. CONTENTS AERONAUTICS Landing on the Wheel within Wheels........ Thirteen Hours in the Balloon Rigging Blazing the Airman’s Trail................... Its Wings Carry the Engines................ This Airplane Is Not Traveling to the Pole.. High-Flying in a Sealed Airplane Steering with the Gyroscope................. Loading an Airplane Through Its Nose FOR THE FARMER TO Rest the Tractors Pull. ........55..00cc0. Grinding Wheat for the Neighborhood Beautifying the R. F. D. Mailbox Wind It Up and J-et It Work An Aid to Irrigation........... Keep the Water Cool for the Hens............ No Stones Will Clog This Irrigation Pipe... . HOUSEKEEPING MADE EASY For Greater Gas-Burner Efficiency Economizing on Coal. . area Bell Rings When Bottle Is Empty............. Scrubbing Floors with a Hand Machine Living-Room and Bedroom in One Let Steam Do the Family Washing Hot Springs in Iceland Casters for the Water-Bucket A Round Table that Folds................ Feed the Pup from a Cake-Tin................ The Filipinos Iron Clothes with their Feet... .. Drying the Safety-Razor Blade... seen wees INDUSTRIAL PROGRESS Making a Heavy Crane Obey a Touch Build a Sectional Storage-Tank............... A Train that Straddles the Track Piping Coal Into New York A Burglar Alarm for Stores Water-Cooling Furnace...................00- Keeping a Watch on the Coal’s Temperature. . Detening the Barrel-Head.............00.00- No Rest for This Auger............0.eeceeeee Iron asa Rubber Substitute.................. (Continued on page 4)

41 52 55 57 67 68 39 42 44 45 55 65 65 6/ 68 69 26

Copyright, 1921, by the Modern Publishing Company POPULAR SCIENCE MONTHLY is issued monthly. Yearly subscription in the United States, $3.00. Canada, $3.50. Foreign, $4.00. Single copy, 25 cents. Advertising rates on application, twentieth of the second publication. Forms close the month preceding date ol Entered as second-class matter Dec. 28, 1915, at the Post Office at New York under the act of March 3, 1879. ter at the Post Office Department, Canada. Entered as second-class mat- The contents of this magazine are copyrighted and must not be reprinted without permission. H. J. Fisher, President; R. C. Wilson, Vice-President; O. B. Capen, Secretary and Treasurer. Modern Publishing Company 225 West Thirty-ninth St. New York City

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