Popular Science Monthly 1924-01: Vol 104 Iss 1

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Law SE teas NUARY Hydro-Glider Skims the Waves at 70 Miles an Hour 25 CENTS Most Wonderfully Illustrated Magazine in the World

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POPULAR SCIENCE MONTHLY The SIXTH SENSE of INDUSTRY > Temperature Control If Seeing was Believing CO F seeing was believing in making cutlery the temper of the steel blades would be the same gamble it was before quan- tity production demanded uniformity of quality. In the old days the quality of steel blades depended on the eyesight of the man who was tempering the blade. He watched the successive color changes as he held the heated metal in oil. It was his job to “hoid” the temper by plunging the blade in water when it reached the color he believed would give the temper wanted. But after all, the workman was human —and being human his judgment was not always right—and when he misjudged the moment for cooling the steel blade, the blade never gave satis- factory service. It may have “looked” like a good blade; it may have “felt” like a good blade—but when used it wasn’t up to standard. Modern manufacturing — and selling requires exact uniform- ity of products. The uncertainty in manufacturing that always exists when the human senses are gambled on can be eliminated by substituting Tycos—the sixth sense of industry. In making cutlery, bread, phonograph records or anything else requiring exact temperature, Tycos Instruments will give accurate results. Nothing is left to the sense of sight —guess- work is eliminated when Tycos Temperature Indicating, Recording and Controlling Instruments are used. This sixth sense of industry —Tycos Temperature Control, ensures the uniformity of quality that is absolutely essential to manufacturing on a quantity basis. Tycos in the Home Fyeoe Office Thermometers An aid in promoting hu- man efficiency. Zyeoe Bath Thermometers To enable you to get the most good from your bath. Fyeos Home Set Bake Oven Ther- mometer. Candy Ther- mometer. Sugar Meter. The secret of accurate results in cooking. Tycoe Wall Thermometers To help you maintain a temperature in your house conducive to good health, Your dealer will show them to you. on a postal, for booklets on any of the above. Seeing Jeeling Tycos Control Freoe Quality Compasses. To show you the right way in unfamiliar coun- try. Tycoe Fever Thermometers A necessity in every ome, 4 Fycoe Stormoguide Forecasts the weather twenty-four hours ahead with dependable accu- racy. Fycos Hygrometer To enable you to keep the humidity of the at- mosphere in your home correct at all times, Ask us, SIX SENSES Hearing Smelling Tasting and «= Temperature ee Pn at app ae Line ie BF oka seria secicsestineiiensjainianglincgtaae rn pee z . eae er ee a i EP a = ] Jycos and the MEDICAL Profession Jycos Sohygmomanameter, Pocket and Office type Zycoe Urinalysis Glassware. Zycos Fever Thermometers, Bulletins on request. ™“% se red an eI RNG ONE LIS MANUFACTURERS What is your problem of applying this “sixth sense” to your plant? What do you make? Write us and information on any instrument or type of instrument will be sent you promptly. Tycos engineers are ready to show you how it will save money in your plant. There is no charge for such service. ero Maen, paneer 0 Canadian Plant cos BUILDING TORONTO Taylor Instrument Companies Main Office and Factory ROCHESTER, N. Y., U.S.A. ae. sects cmon caecietecipate ie ccatnernmnirce es eee PR RBS ac AINE: ONIN a A RET Rae a a EASES AE

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JANUARY, 1924; Vol. 104, No. 1 | 25 cents a Copy; $2.50 a Year

N 1843 an official of the United States Patent Office resigned “because every- thing possible had been invented.” He added that in his judgment it was only a matter of months until the Patent Office would be forced to close through lack of business. And that was before PopuLar SciENCE MONTHLY | Most Wonderfully Illustrated Magazine in the World

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

knew about it? Does it ever occur to you that your idea might be worth money to you? * HEN * a leak in the plumb-

In Next Month’s Issue Astronomy from the Cellar—The fascin- ating story of a New England governor’s underground observatory. Our Senses—Gateways of Knowledge —A usable article in Dr. James J. Walsh’s psychological series. ‘‘The Story of the Mind” tells how you can use your mind to get greater happiness, better health, and bigger success out of life. Your Radio Troubles — Jack Binns, America’s most popular writer on radio, will tell where they come from and how to avoid them. Frozen Radiators—Balky Engines—An expert tells how to prevent annoying and costly automobile troubles in winter. Secrets of the Mighty Atom—The most remarkable photographs ever published, showing the nature and movements of atoms, reproduced through the courtesy of Sir Ernest Rutherford, great British physicist. And 200 other fascinating articles and pictures

You may say you you do something about the house—when you devise a temporary way to stop the windows from rattling, or stop valuable inventions often spring. More than 50 years ago a man got the idea that a rubber at the end of a pencil might be a con- venience. This may have been a. trivial thought, but it netted him a fortune. The safety razor, the foun- tain pen, the metal cap for bottles are simple things; yet they have brought wealth to their inventors and manu- facturers. * * HOUSANDS of devices of this sort still remain to be invented. Successful inventors have reduced the business of inven- tion to a formula. Look about you until you observe some human need, they say; then go about satisfying that need. _ tence tells the story of every invention. That short sen- Probably you need not look beyond your- self to recognize some human need that happiness? invention might satisfy. that would add to your own comfort and Invent it. Is there something If it is useful to you, it will be useful

ing—you are doing PopuLAR SCIENCE MONTHLY to others. Moreover, the rewards of in-

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Does it ever occur to you that what you are doing might be something that thousands of others would do if they vention are paid not only in money, but in the priceless satis- faction that results from successful cre- Issued monthly. Single copy, 25 cents. Yearly subscription to United States, its possessions, and Canada, $2.50; foreign countries, $3. Entered as second-class matter Dec. 28, 1918, at the Post Office at New York under the act of March 3, 1879. Entered as second-class matter at the Post Office Department, Canada. Printed in U. S. A Copyright, 1923, by the Modern Publishing Co. The contents of this magazine must not be reprinted without permission. Fisher, President; R. C. Wilson, Vice-President B. Capen, Secretary and Treasurer

ative work.

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hd % DR. PAUL BARTSCH, head of the Division of Mollusks of the Smith- sonian Institute, Washing- 0} ton, D. C., demonstrating the compact underwater motion - picture camera which he has invented to photograph creatures of the sea. Diving into the clear waters about the Bahama Islands, he recently ob- tained remarkable movies of many varieties of strange fishes in their native haunts ka & @ Bee

DR. S. C. LIND, new Chief Chemist of the United States Bureau of Mines, is one of the foremost radium experts in the United States. He is shown above with his own invention, an improved electro- scope designed for measuring radium. When the in- strument is placed in the field of radium emanations, the time required to discharge the electroscope deter- mines the percentage of radium in the sample DR. W. W. CAMPBELL (left), director of the Lick Observatory and president of the University of Califor- nia, in a recent statement declared that certain areas of Mars, as detected through the telescope, change in color with the seasons, indicating that there might be vegetable life on Mars DR. ROBERT A. MILLIKAN, of the California Institute of Technology (right), has been awarded the Edison Medal for meritorious achievement in electrical research by the American In- stitute of Electrical Engineers. In pre- senting the award, Dr. F. B. Jewett, president of the institute, declared that “in the last two decades Millikan has done more to influence young men toward clear thinking in scientific re- search than any other man in America.”

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POPULAR SCIENCE MONTHLY 1Ve In ais with your Age. : | Sao Tzu —— Io be in harmory with Khe present ase you must ewn a : REB BROADCAST RECEIVER | atalty ; 6é HE 20-foot silk-covered wire, supplied with this Receiver, is the only antenna required. This wire may be concealed behind the 3 picture moulding or run along the baseboard a in your library or living room. Fee The beautifui walnut cabinet has compart- © = ments for all necessary batteries. Write for “Grebe Radio in the Well-Appointed Home” en Se Ee + A. H. GREBE & COMPANY, Inc. t, Richmond Hill, N.Y. Western Branch, 451 East 3rd St., Los Angeles, Cal. we pitinhie Sth al ih Reet AER - rere tere

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POPULAR SCIENCE MONTHLY SUMNER N. BLOSSOM, Editor January, 1924 Take the Brakes off Your Brain! First Article of a Vitally Useful Psychological Sertes— pe ene ene FEW days ago a small fire occurred in a house near mine. I happened to be looking out of my window when a man rushed down the street to turn in an alarm at the corner box. In an almost unbelievably short time—not more than two or three minutes—a fire engine pulled up before the house. A few minutes later the blaze had been ex- tinguished and the engine had departed. A Wonderful Alarm System This was no extraordinary occurrence; simply a commonplace incident of pres- ent-day city life. Still, I could not but wonder at the swift passage of events that followed the ringing of the alarm. Here was a marvelous combination of human ingenuity and discipline. Au- tomatically the touch of a finger on a switch within the alarm box had sum- moned a roaring engine to the exact location of the fire. Then, with per- fect teamwork and precision, their trained firemen had gone about the work of putting out the blaze. And yet, as a psychologist, I had little reason to marvelat , what I saw. For the complex electrical fire-alarm system and the perfect discipline of the firemen represent- ed only an imperfect im- itation of the wonder- fully sensitive alarm system operating in every normal human body. At the heart of this system is a central control station—the brain. Leading from it to every “corner box” of the body is anelaborate network of wires—our nerves. And finally, responding to every interchange of mes- sages or alarms, that flash along the nerves to and from the brain are our muscles, per- forming for us the movements necessary to protect and sup- port our lives. On the degree of perfection with which this complicated nerve system functions, and on the precision and discipline of our muscles in responding to every signal flashed to the brain, depends largely our success in meeting the tasks The Story of the Mind By James J. Walsh, M.D., Ph.D. Famous American Surgeon and Psychologist or emergencies that every-day life pre- sents. To learn the secret of this wonder- ful network of living nerves and muscles, to discover its weaknesses, repair its faults, and to make it respond more surely to our common needs—this is the part of psychology. At one of the World Series baseball games in New York last fall I witnessed an incident that illustrated in a vivid way the workings of the human alarm system. One of the Yankee batsmen hit a fly ball over first base, well out in right field. It was beyond ihe reach of the first baseman and the right fielder— ULE ‘4 Way : Woy, Wy, hy This chimpanzee represents one of the very highest orders of animal intelli- gence; yet his capabilities end where those of the baly begin. Animal instincts rule the life of the chimpanzee. He has reached his limit of progress. But in the baby the mind is master. The baby can reason; and there is no limit to his progress and the heights he can achieve apparently a safe hit. And yet the fly was caught by Frisch, second- baseman, of the Giants, even though, when the ball was hit, he was stationed farther away from its ultimate landing place than any other player. The reason Frisch caught the ball was this: Almost at the instant the batsman struck the ball, Frisch had started running in the direction it was traveling. In fact, to most people in the stands his first movement seemed to coincide with the crack of bat on ball. Messages Flashed to the Brain Yet the two events really were not simultaneous. Between the instant the bat touched the ball and the instant that Frisch started to run, there was an infinitesimal pause. And during that pause, a highly complicated series of actions and reactions had taken place in his body—comparable to the trans- mission of electric signals and the re- sultant appearance of the fire engines, but infinitely more complex and infinitely ~, more certain. The crack of the bat stirred into . action delicate nerve centers controlling the man’s vision and his hearing. From these nerve centers, sensitive nerves carried a report of that event to certain brain cells. These, accepting the message transmitted from the eyes and ears, retransmitted it along another line of nérves to the muscles that carried him in the direction of the ball. And not until these muscles re- ceived the relayed message did he move. That may seem like a long and complicated explanation of a _ process that took place in a space of time so short as to be virtually incalculable; but it is typical of the working of the wonderful human nervous system and its guiding power, the brain. Every time we per- form a conscious action, there is just such an interchange of messages between our nerve cen- ters, our brain and our muscles. If you accidentally touch the glowing end of a cigar, you quickly draw your hand away. This may seem to you ' 31 Nae anaes

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CRS. > eet TS ee ll i i ln intent 5 ly be BFS ja 32 to be an instinctive action—one performed more or less automatically by your muscles without the direction of your brain. But it is not. You pull your hand away because your brain, sending the message of pain from your finger tips, directs your muscles to remove it from the danger area, just as the brain of the baseball player directed his muscles’ to POPULAR SCIENCE MONTHLY It will struggle madly, clawing at the sides of the box, hurling itself about as a pro- test against its confinement; but all its efforts will fail to bring release unless, of course, it should touch accidentally the lever operating the lid. But lock a man in a similar box and observe how different are his actions. He science by experiments with animals, dis- trolling its own set of muscles. Long ago covered the specific locations of the motor centers controlling the movements of the legs, arms, face, fingers, in fact, every part of the body. nd Psychology, the scientific study of the mind, has revealed one extremely im- portant fact about carry him toward the flying ball. Yet while proc- esses of this sort may seem compli- cated, really they are elementary when compared with other and more amazing processes by which our brains and nerve systems serve our needs. Even the lower animals possess nervous organiza- tions that guide them in avoiding danger or pain and enable them to HE SEES perform actions necessary to sup- port life. The Chimpanzee Consider the chimpanzee shown with the child on the preceding page. The chimpanzee has a high order of animal intelli- gence; it can do some things that are as yet beyond the capabilities of the child. But the animal can’t rea- gon and in a few months the child will outstrip it mentally. The FLAPJACKS STIMULATED; TAST BPAND SMELL STIMULATED chimpanzee lives by its animal in- stincts. It never can progress. But there is no limit to the progress of the child. The one impor- tant and essential difference that dis- tinguishes man from the lower an- imals is that man possesses a mind. He reasons. His How the Brain Controls the Body MOTOR CENTERS RESPOND these motor cen- ters that holds the key to success or failure. It is this: Impulse Needed ao IMAGINATION ENTERS SITS AT RESTAURANT TABLE ORDERS without, transmits the sensation of hunger to the body and moves the muscles to responsive action. The man in the pictures first sees flapjacks cook- ing in the window. Through the visual center of the brain his imagination is stimulated. He imagines himself in the restaurant eating flapjacks, which ~ GLAND SECRETIONS IN MOUTH, THROAT AND STOMACH INCREASE DESIRE FOR FOOD ERE is a picture story of how the _ causes stimulation of the senses of taste M an Reasons H brain, receiving stimuli from and smell and of certain glands of throat and stomach. Through their secretions, these glands bring increased desire for food—the mouth-watering Noises in the restaurant add still another stimulus. All these sense messages are transmitted through the motor centers to the muscles, which act to satisfy the hunger sensation. —~ Your brain, though it is the ruler of your body, has not the power of itself to initiate thought; nor can it, of itself, direct your muscles to perform any defi- nite action. It must receive, first, a sug- gestion or impulse from without. A ring of your doorbell, the en- trance of another person into the , room where you STIMULUS: are reading, or HE HEARS some other inter- NOISE OF ruption, may cause DISHES you to put down this magazine—a thing which, if you are interested, you FRONT OF probably have no intention of doing. Or, take the case of Frisch, the Gi- ants’ second-base- man. His motor centers did not di- rect his muscles to move toward the fly ball until after his brain had per- ceived that move- ment was neces- GLAND RESULT; ; THROAT = STOMACH cecreTiONS FEELING OF sary if he was to a. _y SATISFACTION intercept the ball. Why You. Act Although you may be awake, you will not rise from your bed in the morning until the sunlight or the sight of your clock informs you that the time has come your duties. On . your way to take life is ruled not by every passing im- pulse that flashes across the transmission lines of his nerves. Rather, his mind is master. His brain, the central station, rules. It is the guiding power of his ner- vous system, and consequently of his body and its functions. Lock a cat in a box covered by a lid that will spring open at the touch of a lever, and the cat will remain a prisoner. will not struggle, he will not hurry. He will consider his situation calmly until he discovers that by moving the lever he may cause the lid to rise and so gain his freedom. In every normal, healthy man the brain is ruler. It exercises its control over his muscles through certain groups of brain cells called motor centers, each con- the street car to your office or shop you will not hurry unless you learn in some way that hurry is necessary because you have left your home at a later time than usual. Alsd, you probably would not be going.to work at all had your brain not learned, either from your own experience in the past or by informa- tion you have received repeatedly from (Continued on page 130) for youto be about.

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Army Airship Rescues Fallen Aviator from the Sea effective life-saver at sea. The il- lustration, from an actual photo- graph, shows the spectacular rescue of a fallen aviator by the U. S. A. airship D-3 recently off Cape Hatteras. The remarkable feat was accomplished by lowering the airship to within 15 feet "Te airship has proved itself to be an of the water. The ship’s speed then was killed by heading it into the wind and idling the motors. With a rope ladder trailing in the water, the ship approached the wrecked airplane slowly until the swimming aviator could grasp the end of the ladder and climb to safety. To allow for the weight of the extra passenger, ballast was thrown out, and the D-3 rose again, In performing the rescue the D-3 was commanded by Captain William O. Butler, 19th Airship Company, Langley Field, Va... The rescued aviator was Staff Sergeant. Charles V. Williams of the same company. tere ea ETT: - tS AMO Re IEE NS SE TED ALE ELLE LPL OP LE EE copnenenarserncpuehrimmarsnationentt en TER ee ee 3 EA enema TES AE SA x os a

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Seventy Miles an Hour in a Hydro-Glider New Aur-Propelled Boat Skims Waves at Express-Train Speed inches of water is the astounding performance claimed for a revolu- tionary new type of air-propelled glider- boat developed by F..W. Davies, of Dud- ley, England. This feat is the more impressive be- cause, unlike most craft that threaten the world’s speed record, the Davies hydro- glider conquers water not by sheer, costly massing of compact power, but essentially by minimizing friction. Nautical super- speed, hitherto exclusively a sport of open-handed millionaires, there- GS inches o miles an hour in three POPULAR SCIENCE MONTHLY shallow draft is the wide, somewhat flat bottom. The weight is distributed over a large water area, sharply limiting the dis- placement depth. This construction not only greatly reduces the danger of wreck and injury by lifting the craft’s bottom above the reach of most underwater dan- gers, but further lessens the potential friction. For at high speeds the hydro- glider skips from wave to wave instead of pushing through the water. The lifting power of the water is utilized to the utter- most, while the resistant strength of it is

An airplane engine and propeller, mounted high on braced struts, drive the new speed craft scientific design of the Davies craft. Only the cockpit portion is raised. The hull is low and flat to prevent resistance to the lusty breeze encountered at high speeds. The forward end of the cockpit is

fore is brought within the reach of every water lover. Commuters May Use It But its importance<as a new plaything for sportsmén is over- shadowed by its significance as a promising attack on tke problem of commuting to and from large cities. A New-Yorker with one of these wave-skimming boats could enjoy the pleasures and economies of country residence, commuting daily down Long Island Sound or the Hudson. Every inland water- way in the country, such as the Great Lakes, the Mississippi and Missouri rivers, would become a

A Busy Man’s Hobby—The Stars D! D you ever consider the significance of the fact that the small end of an astronomical telescope always points toward the earth, while the large end points to the heavens? James Hartness, former governor of Vermont, noted engineer, inventor, and business man, is one man who has. ‘“‘Whenever my worries get too much for me, I find solace in my telescope,’’ he says in a notable interview in next month’s POPULAR SCIENCE MONTHLY. “Then the seeming importance of the little affairs of this world pales to insignificance in comparison with the vast worlds that lie beyond us.” Don’t miss this fascinating story of Mr. Hartness’ hobby—aremarkable underground observatory where he embarks on wonderful journeys into the skies. propeller. tervals with

quick and open road to points now sparsely settled because of the slow speeds at which most river and lake craft travel. An airplane propeller and engine drive the hydro-glider. Thus the enormous friction exerted by water upon high-speed propeller blades is avoided to a marked degree. Thus the new craft adapts the most efficient prin- ciples of the famous seasleds, which some years ago upset many traditions of nauti- cal construction. Even wind friction is reduced by the rounded for the same reason. The hull is oblong in. shape, with a tapering tail upon which is the main rudder, operating di- rectly in the air stream from the Strength of Construction The airplane engine and the air screw are mounted high on struts braced by diagonal wires. The cockpit, forward of the engine, seats six persons. The main walls of the hull are braced at close in- timbers, while the longitudinal stringers and the keel are fastened by stout metal gusset plates riveted together. The bot- tom, which bears a great strain, consists of two skins laid at 45 de- grees to each other. A double layer of chemically treated and copper-fastened fabric lies between these skins. Moreover, the bottom is constructed so that a dam- aged plank can be replaced at slight cost.

avoided. Moreover, such propulsion helps achieve the shallow-water oper- ation that is impera- tive for safe naviga- tion on many lake and river stretches. The Rudder Even the main rudder, a high, finlike projection, “operates by deflect- ing air instead of water. Two small water rudders are located on the tran- som for maneuver- ing, but they rise above the surface as soon as the craft has picked up speed. ae The chief factor ais in effecting the craft’s amazingly “

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The hydro-glider piloted by its inventor, F. W. Davies, of Dudley, England, during recent tests in which the novel craft skipped over the waves at a speed of 70 miles an hour . Perfect control of the craft is said to be possible at all speeds. At _half throttle it is suid to glide 40 miles an hour. Because of the reduction of friction its fuel cost is low. The world’s speed record for power boats, 81.5 miles an hour, is held by Miss ‘America JI, Gar Wood’s hurricane. Yet the Davies hydro-glider, an em- bodiment of striking departures in design, almost equalled this record in its first trials. It demon- strated thus the soundness of prin- ciples which may set a new mark forspeed boats to shoot at. motorized

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POPULAR SCIENCE MONTHLY 35 Cameras Pick Race - Track Winners By Truman Stevens SWIFT, short flash—often only a A blur of straining heads—upon the retina of a human eye decides the winner of most horse races. Thousands and occasionally millions of dollars poise upon that flash. Hundreds of decisions have been questioned, many no doubt justly, for even a judge’s eyes are humanly fallible. But lately on a Belgian track a specially devised camera, ingeniously connected with a finish tape, has been the court of last resort. This invention, recently im- proved by a Frenchman, now awards contested places at the famous Maisons- Lafitte track. A green cotton thread that operates the camera shutters when touched by the winning horse, is stretched across the track at the height of a horse’s breast. It is just enough in front of the finish line so that the photograph registers the exact moment when the winner’s nose appears in line with the winning post. Two posts, from 23 to 26 feet high, one atop the judges’ box, the other on the op- posite side of the track, are equipped each with three convergent cameras. These are disposed so that a fine vertical line RECORDS OTHER rf. CONTESTANTS le just before the focal center of the glass screen of each camera is in line with the winning post and the judges’ view. Four of these six cameras—two on each post—are operated simu'tane- ously when the winner’s breast touches the finish thread. Two of the four—one on each post— ; have one focus, and the other ~ La two have another focus, giving -

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four varying pictures. Thus a good photograph of every horse and of every inch of the finish line is assured. A fine A close finish, automatically photographed from the judges’ box. The black vertical line across the center of the photograph, produced by a fine thread in front of the camera lens, is in line with the finish post. It’s easy by this method for the judges to pick the winning horse line indicates on each photo- graph the location of the finish line. The remaining cameras—one on each post—are released simyltaneously by an operator. These two are intended to photograph a group containing one or more placed horses when such a group is separated from the winning horse by some distance. The thread that actuates the automatic cameras will withstand a steady tension of nearly 20 pounds, but will break at a slight shock. It ends at each post in an electric contact formed of two flexible plates barely separated. Contact be- tween the winner’s breast and the thread The diagram below shows how triple cameras are focused on the finish line on each side of the course at the winning post. arranged to focus on every horse. Note how the cameras are At the left is one of the triple cameras, and at the right, the automatic apparatus that opens the camera shutters when the winning horse ‘touches a thread stretched across the finish line causes an increased tension resulting in an instantaneous contact between the plates. The resultant current, through a magnet, releases the shutters of all four cameras. Three minutes after the race is won, the pictures establishing the winners are de- veloped. If the judges have no doubt of the result, they announce the decision as soon as the race is over. Otherwise the word ‘‘Photograph” is posted and the on- lookers await the verdict of the mechani- cal judges.

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Cheeni te Sot a eottaatent ati mdy ft wet me a aren I A a 8 me en ee I — POPULAR SCIENCE MONTHLY Air Flivvers for Ever Midget Planes to Sell for $150 and to Fly on a Thimbleful of Gasoline By Donald Harris A LITTLE more than 20 years ago, people rushed to their front doors to watch an automobile go by. Ten years ago an airplane could draw the eyes of a countryside. How long must we wait before the airplane becomes like the automobile, a commonplace of transportation, a family convenience? How soon before the housewife, who once lifted the kitchen window at the droning roar of a plane, looks down upon that kitchen window from where the birds are? In a few years, at most. In the recent international motor glider contest at Lympne, England, two pilots each flew 87 miles on a gallon of gasoline. Another drove his tiny sky sparrow at a | —— speed of 75 miles an hour. aerial midgets were Their average cost was only $1000. Such sensational achievements are comparatively virgin field of aviation. sibilities. mile speed record are pioneering feats. dollars will not long remain the These amazing restricted to en- gines of not more than 7!4 horsepower and to a width of 10 feet from wing tip to wing tip. in a The “flying flivver” is an infant, with an infant’s pos- The 87-mile gasoline record and the 75- One thousand ~ minimum cost of such machines. Lawrence Sperry, inventor of A the tiny ‘‘messenger’’ plane, con- fidently predicts that the $150 plane is only a few years away. Quantity production of small engines is now the only thing standing in the way of such cheap machines. These engines could be built in large numbers for $50 each, according to Henry Ford. But, ignoring everything ex- cept achieved facts, we find the implications of such facts tre- mendovs and astounding. Te The above photograph of the world’s smallest gasoline engine gives an idea of what we may ex- pect in the development of inex- pensive power plants for future air flivvers. This engine, dis- played recently in London, is said to run 250 miles on a gallon of gas- oline and to drive a motorcycle at an average speed of 25 miles an hour. In the recent air-flivver contest in England, 7 )4-horse- power airplane engines of the One of these “air babies” could fly from New York to Chicago, 908 miles by rail, in 12 hours on 101% gallons of gasoline. The fastest train takes 20 hours. At prevaii- ing fares and gasoline prices, the aerial trip would cost nearly $30 less than the rail trip. Railroad fares the country over average 3.6 cents a mile. Investment and upkeep aside, the air flivver fare would be .3 of a cent a mile. A Short Hop between Cities To one of these Tom Thumb planes, Chicago and Omaha would be 6) hours apart. Chicago and St. Paul, or New York and Pittsburgh, would be six hours apart. Eight hours would separate New York and Akron. A Senator could leave Washington, D. C., at 10 A.M. and keep a speaking engagement in Chicago at 8.30 in the evening. Flying 10 hours a day, one of these planes easily could reach San Francisco from Chicago in three days. A 13-hour flight would put a Seattle business man 2t a conference in San Francisco. A Vickers “air baby,” of less than 10-feet wing spread, piloted by Captain Cockerell, in test flight at Lympne, England All these figures are based on railroad mileage. And a plane flies as does the crow. The commuting possibilities of the “air flivver’’ beggar the splendid achievements of the automobile and the electric train. Thousands of commuters spend an hour riding to and from their work twice daily. The expenditure of the same amount of time with an aerial flivver would bring cheap land, country rents, and country life within reach of millions in the over- grown cities. At the close of the day the New Yorker could take aa elevator to the roof of his office building and fly to dinner with his family in the quiet of New Hamp- shire’s White Mountains, or in the Adiron- dacks. True, there are now no adequate facili- ties for landing or for the housing of planes. But how old are service stations and garages? Protected skyscraper tops would offer ideal landing areas. Beacon routes for night flying, proved a success by motorcycle type drove baby planes 87 miles on a gallon of gaso- line at a speed of 75 miles an hour the recent night air-mail tests, will inter- lace across the continent as rapidly as the need for them widens, as surely as good roads followed the automobile. Aerial vacationing and week-ending on a grand scale are as obviously impending facts—facts that we shall accept soon as calmly as we now accept radio. Week-Ends in Remote Places Small, speedy airplanes would enable Chicago business men to enjoy their week-ends in the Canadian lake country and their summer vacations in the Rock- ies. The miles that separate inland lovers of the sea from ocean beaches would shrink. - Yellowstone would be eight hours from the farmers of middle Kansas, while New York winters would be 12 hours from Florida’s beaches. In fact, the “air flivver’’ would make every foot of America accessible. Remote and hitherto inaccessible fastnesses of a ic E a le v t © meas = © es)

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POPULAR SCIENCE MONTHLY

Lawrence Sperry, known as the American father of the air flivver, in his baby plane, the Messenger, on the plaza of the Capitol at Washington, D.C. This plane has a wing spread of only 20 feet. Sperry predicts that the day of the $150 airplane is not far distant nature could be invaded with ease. Rich men may buy mountain tops upon which to build their estates. It may not be too much to predict that far-seeing real estate operators will have the opportunity to pile up tremendous fortunes, as did the original Astors, by buying for a song isolated plots of land within airplane commuting distance of large centers. Certain it is that as popu- lation increases so will the demand for property in what are now remote sections. Moreover, the city’s advantages in cul- ture, entertainment, shopping facilities, and variety would, by means of the small, speedy plane, be brought as close to the farmer and the long-distance commuter as was the grocery store before gasoline outstripped hoofs. The country dweller’s family physician could be one of the city’s best. Neither drifted snows nor bad roads would stop a plane. In the air there are no grade crossings, blind corners, speed limits, nor traffic congestion. An airplane is a simpler mechanism than an auto- mobile of corresponding quality. Fewer mechani- eal problems have con- fronted aeronautical de- signers. Cost to Be Low

As a_ result, modern airplanes are mechan- ically almost perfect. Hence the cost of planes and their upkeep—after large-scale production and wide use have done for them what they did for automobile prices—will be less than that of automo- biles. The flights at Lympne, England, dem- onstrated strikingly their far lower fuel demands. machine flew 87 miles on a gallon of gasoline. through a seven-foot gate in a qualification test. These facts, in the light of the past year’s astonishing strides toward ultra- practical aviation, add significance to Henry Ford’s recent interest in small air- plane development. A year ago he an- nounced that he would not make planes

Competing in the motor glider contest at Lympne, England, this midget Wren the Wren’s 314-horsepower engine being refilled The “air baby” is shown passing The upper picture shows

aati an nteneseeecineitnrentissnsencoemmasscenssamecstatll until they had become commercially prac- tical on a generous scale. Airplane driving—high speed and trick flying aside—is not a difficult art. It can- not be learned as easily as automobile driving, but, once learned, it is easier. With rare exceptions, the men who have mei death in aviation were taking danger- ous and unnecessary chances, just as the goggled heroes of the .automobile race- track have taken chances and paid. What the race drivers of the track did to make your car safe, the daredevils of the air have done to make flying safe for you. The Sensible Flier Is Safe Only in one case in a hundred is an aerial accident today a consequence of mechanical defect. And even in such rare cases—though the engine stops or the propeller breaks—a plane is in no par- » ticular danger. Side-slip- ping and careful gliding in practically every case will effect a safe landing. Even if a tree or building is struck in landing, a driver is not likely to be hurt; for landing speeds, particu- larly those of small planes, need not be great enough for bodily injury. In short, a sensible flyer is safer than a sensible motorist, because the wide roads of the air minimize the danger from fools. The automobile altered the course of civilization profoundly and beyond measure. It left no house- hold and no life un- touched. It is conceiv-

able that the airplane will be just as revolutionary; and the air flivver is to- day’s signpost in our swift progress toward that era. —*

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TREN CFE ET mete Foe ATP WLP rat besenerane IM bap aR ot onc regen PY Ee Pee sok pentane = stem errr 38 POPULAR SCIENCE MONTHLY How My Home Workshop Helps Me to Build Stories By Arthur Stringer Noted American fiction writer, author of ‘‘The Prairie Wife’’ and many other novels and short stories activity that this brain of ours rests most when it is most earnestly at work. Expenditure, in this case, is the true source of economy. If you are a child, you play a game. If you are a grown-up, you have a hobby. And if you are a normal man it’s ten to one you will take your avocation much more seriously than you do i IS one of the paradoxes of mental child’s imagination tints its rag doll with the coloring of life. A hobby, in this era of specialized labor, is also a wonderful preserver of balance. There is a fixed belief, of course, that authors have an uncommonly easy time of it, that their vocation is neither specialized labor nor any kind of labor. But after producing almost 30 volumes— on her throne and efficiency on her feet. Being already a builder of plots may have had something to do with it. But after carefully carpentering together a novel, I have found it unexpectedly restful to car- penter together a lawn bench. My sub- conscious impulse was still to build. So I embarked on a recreational orgy of furniture making. Most of it, I’m afraid, was very bad furniture. Some your vocation. of it was so bad that my dis- Now this word “hobby,” if etymology and memory serve me aright, comes from the “‘hoabby-horse”’ of the old mor- rig dances, the painted wooden imitation of a horse which, in- stead of carrying the actor on its back, was actually carried about by that actor. Soa man is always most squarely on his feet when he rides a hobby. And the hobby which I have found most stabilizing and stimulating, in my own case, is a home workshop. Why I Prefer the Shop It was not ever thus, I’m willing to confess, for I’ve tried my restless hand at many things. When a friend asked me why I gave up golf for a tool-littered imitation of a constructive. important thing. It’s the Fun that Counts 7 MAN is always most squarely on his feet when he rides a hobby,” says Arthur Stringer. hobby, I find, has one subtle yet dis- tinct advantage over a game—it is It is something done for a definite and perceptible end. ‘In my own case, after much experi- menting, I found in a home workshop that nice balance between physical and mental effort that tended to keep reason on her throne and efficiency on her feet. “My immediate product is not the It’s the fun I get out of making my wabbly old period pieces.”’ cerning spouse committed it to the fireplace as promptly as the female infants of India were once committed to the Ganges. Some of it, after being duly put together, fell to pieces again “A like the One-Horse Shay. Learning the Trade But I am learning. My tech- nique may not be perfect, but my ambitions are now re- strained. I can at last make a highboy that stands on all four legs at once. I know how to stain and finish seven kinds of wood to convert it into true mahogany. I still occasionally cut myself with a drawknife and I still occasionally hammer my thumb. But I can at last console my Better Nature with the thought that I am doing cabinetmaker’s workshop, I said it was because I got more fun out of the workshop. When that same persistent friend wanted to know just why I got more fun out of my workshop, I had to put aside my jack-plane and sit down and fish for reasons. I had to brush the sawdust off my over- alls and tell him there were moods and moments when golf struck me as essen- tially childish, as so essentially childish that the vision of three or four dozen sclerotic old gentlemen solemnly knocking little white balls about 400 acres of landscape impressed me as slightly pathetic. There was something so _ self-defeat- ingly futile about them all. Now a hobby, I find, has one subtle yet distinct advantage over a game. It is constructive, in so far as interest in it survives the moment of its practice. It is something done for a definite and perceptible end. And, being such, it is both self-justifying and self-perpetuating. It is not a self-deluding gesture toward youth, like the game of golf. It can forget to take itself seri- ously, for, unlike golf, it does not have to watch the lighting effects, the lighting effects that tint a mere game with a theatri- calized importance just as a good, bad, and indifferent—I’m grimly forced to the conclusion that this business of trying to amuse the world in its idle moments is much harder work than the world imagines. And the harder we work, the more we seem to need a hobby. In my own case, after much experi- menting, I found in a home workshop that nice balance between physical and mental effort that tended to keep reason “After carefully carpentering together a novel, I have found it unexpectedly restful to carpenter together a lawn bench.” Here is one of the sturdy lawn benches built by Arthur Stringer in his home workshop at Mountain Lakes, N. J. something constructive at the same time that I can console my Better Half with the knowledge that I can make a Louis-Quinze cabinet not unfitted to a second-maid’s bedroom. But my immediate product is not the important thing. It’s the fun I get out of making my wabbly old period pieces that counts. Some day they may no longer be spirited away by a shamefaced family. Some day they may even descend below the timber-line of the third floor. And in the meantime, at any rate, I have my two young sons who firmly believe in my ability with the chisel and saw, what- ever my incapabilities with the pen may be. That belief is founded on bows and arrows (after the three of us saw “‘Robin Hood’’) which can as easily break a second-story window as they can penetrate the painted canvas sides of pass- ing delivery trucks; to say nothing of a windmill that sacrificially raced itself to pieces on the garage gable, and a canoe that unexpectedly turned out to be a submersible, and a box-kite that actually rose above the garden hedge during the well- known tornado of 1921. Nor would it be just to a humble workman to omit a a a a a a’ a,

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etrate say that pieces canoe out to POPULAR SCIENCE MONTHLY 4 ; Yt) ty, Y YW WY MYEHEELELZ: wi RTHUR STRINGER, noted American fiction writer, building furniture in his home workshop at Mountain Lakes, N. J. At the age of 49 he has written 25 novels and innumerable short stories, most of which, he says, have been evolved as by-products of other activities. His first year of newspaper work resulted in his first volume of short stories, “The Loom of Destiny,” in 1898. Again, as editorial writer for the American Press Association, he completed his first real novel, ‘“‘The Silver Poppy.” An attempt to operate a fruit farm in western Ontario resulted in half a dozen books of adventure, including ‘“The Gun Runner,” in 1912. Another venture as a wheat grower in the Alberta foothills led to his three novels of Western life, ““The Prairie Wife,” 1915; “The Prairie Mother,” 1920, and “The Prairie Child,” 1922. He has traveled extensively and is recognized as an authority on criminology. He was homemade Canadian toboggan that got so warped in the steaming, while giving a fit and proper retroussé tilt to its nose, that it developed into a sort of legless retriever and betrayed an unerring in- stinct to circle about on itself and return to the spot from which it first set out. We have also a considerable number of birdhouses, constructed with meticulous care and, so far as we can judge, finished in unimpeachable good taste, which have remained singularly tenantless during the two years of their existence. The song- sters of the air may never, in fact, house born in London, Ontario, February 26, 1874 between those little waiting walls. But the blithe-spirited amateur in carpentry has been rewarded by the swarming thoughts that came to his empty head— and were later committed to paper—as he placidly and contentedly pieced those houses together. SEPRE SETI Le ete aoc *

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LT Ses Ba re tr rca oe tenia IRL Catt PET Po ios) Waters of the Jordan to Restore Palestine As if Fulfilling Old Testament Propiecies, Engineers Harness the Sacred River Baptized; “Rebuild Waste Places”’ POPULAR SCIENCE MONTHLY for Electric Power where Jesus Was or the Lord shall comfort Zion: he will comfort all her waste places; and he will make her wilderness like Eden, and her desert like the garden of the Lord. .’. . And they shall build the old wastes, they shall raise up the former desolations, and they shall repair the waste cities, the desolations oc many generations. From the Biblical prophecies of Isaiah By Raymond J. Brown EEMINGLY in striking accordance b with the prophecies of the Old Testa- ment, modern science has invaded the Holy Land, harnessing for electric power the sacred River Jordan where Christ was baptized. Engineers are im- pounding for irrigation of the arid valleys the waters of the Sea of Galilee where the Apostle Peter cast his nets, draining the fever-breeding swamp lands for agricul- ture, and spreading a web of transmission lines over Palestine from Dan to Beer- sheba and from the Mediterranean to the eastern edge of the Jordan valley. Recently the first electric power station of the enterprise—an oil-burning plant developing 1000 kilowatts—was finished and put in operation at Jaffa (Joppa) on the Mediterranean shore. Similar plants are nearing completion at Haifa and in the holy city of Jerusalem. These three plants, soon to be connected, will supply electric current for municipal, in- dustrial, agricul- tural, and do- mestic purposes. Incidentally they will provide the power to operate an electric rail- way from Jaffa to Jerusalem, the first step toward the ultimate elec- trification of all the Palestine transportation lines. These oil- driven __ plants, however, will be merely a temporary expedient, pending the completion of the vast hydroelectric and irrigation project now being con- structed in the valley of the Jordan. When the work of harnessing the Jordan is completed—in less than four years—the fuel-burning plants will become auxiliary emergency units in an electric system that will make half a million horsepower avail- able—a $5,000,000 undertaking. The ultimate development will require about 20 times this expenditure. The Duke of Sutherland in debate before the British House of Lords not long ago called it “the most substantial contribution so far made by Judaism to the restoration of prosperity to Palestine.” The effect of the completion of the Jordan valley project is bound to be far reaching and revolutionary. Civilization has not advanced appreciably in Palestine since Biblical days. So far as the native population is concerned, no use has been made of the gifts of science, except in a few isolated farming operations. Ox- drawn wooden plows and primitive water wheels for irrigation are the machinery of agriculture. The inhabitants make their journeys on donkeys exactly as Joseph, Mary, and the infant Christ accomplished the flight into Egypt. Water for domestic purposes still is carried in hide sacks from streams and.old wells. Oil lamps illumi- nate the homes. Long ago the forests dis- Building the great dam that will make a natural reservoir of Lake Tiberias—the Sea of Galilee, where the Apostle Peter cast his nets. Camels are used to transport bricks Engineers are spreading a web of transmis- sion lines from Dan to Beersheba and from the Mediterranean to the eastern edge of the Jordan valley, to serve a newly prosperous Palestine with electric light and power appeared from the country, and the rich soil was washed away from the high ground. Neglect has caused the once fer- tile valleys to become swampy and ma- larial. But now, with electricity available, the swamps drained, and the valleys watered, the results of the neglect of centuries are likely to be repaired virtually overnight. Indeed, it is expected that the inhabitants of the Holy Land will make far wider pro- portionate use of the devices of modern invention—especially electrical—than do the people of America and Europe. For engineers say it will be possible to supply electricity throughout Palestine so cheaply that it can be used in every home for cook- ing and heating pur- poses, for which only wealthy persons are other countries. Fur- ther, the eager inter- est with which the native population greeted the _ recent introduction of a small quantity of modern agricultural and construction ma- chinery seems to give evidence that the Jewish and Arab in- habitants both will embrace the opportunity to better their condition of life through the use of modern methods. The work of developing Palestine is being conducted under conces- sions granted by the British Govern- ment, mandatory of Palestine, to Pinhas Rutenberg, civil engineer, who prepared plans for the project after two years’ study of conditions in the Holy Land. The recommen- able to employ it in — > ee a ~ LSet = SB Te a ee ee ee ee ee. ee, ee ee) — .§§ —_ in, in a 6a

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its ly k- r- ct dations he made were agreeable to Zionist interests. When he sought the necessary concessions from the British Govern- ment, he obtained the financial assistance of Baron Edmond de Rothschild. These concessions were granted with certain restrictions regarding the capitalization of the company that would undertake the work, the rates to be charged for electrical energy, and the profits to be made by the company. Later the concessions were taken over under a deed of trust by the Palestine Development Council of New York City. A Tremendous Project The enterprise is of such vast extent, covering practically the whole length of Palestine from north to south and the major portion of its width, that it was found impracticable to execute the entire project at once. It will be carried on in successive steps, keeping pace with the upbuilding of the country. Recently the efficiency of Jewish labor was tested under most unfavorable conditions, in parts of the Jordan where malaria is prevalent. The results are reported to have been most satisfactory in the quality of labor and in the endurance of the workmen. Work is well advanced on the first big undertaking in the harnessing of the Jor- dan—the construction of a power plant situated about eight miles from the river’s efflux from Lake Tiberias, or the Sea of Galilee. At this point a dam is being built similar to the Roosevelt Dam in Arizona. It will make of Lake Tiberias a great natural storage reservoir, containing almost 10,000,000,000 cubic feet of water available for irrigation and power. Canals will be dug on both sides of the Jordan, paralleling its course, to carry this water to 650,000 acres of dry lands. Water required for electric power will be returned to its course in the Jordan after passing through the turbines. Trans- mission lines will carry the power gener- ated to Haifa, Jaffa, and Jerusalem in-a 66,000-volt system. Lake Tiberias pro- vides a natural storage basin which, en- gineers say, is better than engineering Map of the River Jordan power and irrigation project, showing power plants and the canals to carry water from the Lake Tiberias reservoir POPULAR SCIENCE MONTHLY 41 eas its, sat x ren” Gs ee a The baptism of Jesus by John the Baptist in the River Jordan—a reproduction from the famous engraving by Gustav Doré. The waters of the sacred river now are being im- pounded by a force of engineers to supply the Holy Land with electric light, heat, and power could produce, making the total cost of the development low. Conservation of the water re- sources is a necessity to the develop- ment of Palestine, since most of the annual rainfall of about 25 inches occurs during two months in winter. In the nine miles of the course of its upper waters from Lake Merom to Lake Tiberias the Jordan falls 600 feet. This would seem to offer an ideal situation for power develop- ment, but, because of the present lack of means of communication and the more immediate necessity of irri- gation and storage development, it was decided to erect the first power plant below Lake Tiberias. Between this point and the mouth of the Jor- dan in the Dead Sea, 68 miles away, there is a fall of 690 feet. The rate of flow of the Jordan at Lake Tiberias at present ranges from about 100 to 600 cubic feet a second. When storage and regulation is completed and when some of the water above Lake Tiberias is used, the lower course of the Jordan, it is estimated, will have a regulated flow of about 300 cubic feet a second. From these figures it can be seen that the Jordan is a small stream when compared with some of our American rivers, its average width being about 40 feet. However, its regulated flow, coupled with the considerable difference in level between its source and its mouth, makes it adequate to serve as the backbone of the power and irrigation development of Palestine, which is little more than one sixth the size of England. Great cliffs rising above the river banks at certain points along its course make it a Colorado River in miniature, and increase the en- gineering difficulties of the development. Palestine to Have Cheap Electricity At present there is said to be an imme- diate market for an electrical energy out- put of 15,000,000 kilowatt hours in do- mestic and industrial service. The low development cost, permitting service at an unusually low rate, it is claimed, will make electric power at once available for heating and cooking. In the coast cities, particularly, there is need for modern methods of domestic heating. Once the electric supply is available, it is believed, there will be an increasingly rapid growth in demand. Besides the Jordan, the Jarmuk River, ~ 6 Se erg es ee

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a Pees THE: LAN TRESS SO a 42 which flows into the Jordan below Lake Tiberias, is included in the de- velopment project. This river, having an average flow of about 180 cubic feet a second, gains importance as part of the general scheme from the fact that its waters cin be stored at high elevation. Thus they can be led for irrigation purposes into waste lands that stand 1000 feet above the level of Lake Tiberias. To this land the water from the Jarmuk can be carried by siphoning; it can be pumped to higher levels. The second step in the enterprise will be the drainage of marshes and im- pounding of the Jordan springs. Thus, agricultural reclamation of marsh lands will be followed immediately by irrigation and subsequent housing and transportation development. As a minor feature of the scheme, domestic water supply will be provided through- out the region covered by the hy- draulic works. Important as these projects must prove to the whole of Palestine, they are regarded as merely preliminary to the ultimate development of the Holy Land. Probably $100,000,000, it is estimated, will be spent eventually in the restoration of Palestine. Nine power stations, a veritable network of irrigation canals, electric railways, dams, houses, manufacturing plants, POPULAR SCIENCE MONTHLY Above: The Jarmuk water- fall of the Jordan—one of the sources of power to be harnessed. At the right: The first of Palestine’s power stations at Jaffa on the Mediterranean shore. This oil-burning plant eventually will be used as an auxiliary station } “OR wharves, warehouses, and large scale drainage of the marshes already are planned. They await only the adjust- ment of the population to the new order that will be ushered in by the operation of the power station on the Jordan and the reclamation of the waste lands of the valleys. Winston Churchill, Secretary of State for the British Colonies, and others occupying high position in the British Government have expressed themselves with unstinted enthusiasm regarding the Palestine reclamation work. Government restrictions, as has been mentioned, have been placed on the project. The company organized to pursue the work has been limited to a maximum profit of 121% per cent, and the Palestine Government has been authorized to purchase the under- taking after 37 years or at the end of each 10-year period there- after. Many claim to see in the project a first step toward the reali- zation of the Zionist dream of re-establish- ing Palestine as the fatherland of Jewry— a dream that has sur- vived the centuries. Improved Kite Camera Simplifies Aerial Photography UCH of the difficulty usually en- countered in making aerial pho- tographs by means of kites is said to have been overcome by an un- usual kite design and ingenious appa- ratus for suspending the camera that re- cently has been perfected in Germany. One of the chief To assure a gentle release of the camera shutter, without shock, an unusual release gear has been devised. In addition to the main kite cord, a shutter release cord from the ground is tied to the end of a plunger that is held within the upper tube of the camera rig by means of a spiral spring. The other end of the tube is fast- ened to the main flying cord. When the plate is to be exposed, the operator gradually slackens the flying cord and the release cord is taken in so that the plunger is gently pulled out of the cylinder. This causes a trigger projecting from the plunger to handicaps to kite photography in the past has been lack of sufficient lifting capacity to carry the camera aloft and SHUTTER hold it steadily in position in light or fickle winds. The new camera, it is _— claimed, exerts a lift of 72 pounds in A a fair breeze. a A distance of about 170 feet is allowed between the kite and the sus- pension gear of the camera. To direct the lens to any de- sired point while the CAMERA FLYING CORD Pt 12'-O" SPAN “4 TO KITE UNIVERSAL JOINT , camera hangs from the kite string, a Construction of the special suspension new kite camera, ca- pable of lifting 70 AD. pounds, is shown at the evolved consisting of upper right. Above is three tubes linked pictured the ingenious together. apparatus for suspend- 8 er. Small wel ing the kite from the 4 2 cord and for releasing the joints, and into the camera shutter the teeth of these | ‘from the ground. At the right is a typical photograph taken with gear has been wheels are fitted to wheels flat springs engage, holding the this kite camera camera at the de- sired angle. strike the button at the end of the regu- lar camera shutter cable and in conse- quence the desired exposure is made, the shutter being re- leased again when- ever the operator so desires. Here are some precautions that must be observed in air photography: Aerial photos should be attempted only in bright sun- shine, else they will have a flat look. If the camera is a focal plane one, the shutter should be adjusted to the shortest exposure— about one thou- sandth of a second. The lens should be used at full aperture. For deveiopment, a fairly concentrated developer should be used, and the de- velopment must not be broken off too soon.

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le re t- ne ne ne of id he ad on ee rst li- ist sh- he ur= “How My Car Serves Me” Prize-W inners in POPULAR SCIENCE MONTHLY POPULAR SCIENCE MONTHLY Contest Find Novel Uses for Autos Frrom the many contributions submitted in POPULAR SCIENCE MONTHLY’S “How My Car Serves Me” prize con- test, announced in September, the judges have selected the fol- ing three as representing the most ingenious ways of putting the family automobile to work in addition to its regular duties in transportation. The winners are: First Prize, J. M. Scho- Second Prize, E. W. Tee, Brooklyn, N. Y.; Third Prize, Samuel D. Lamis, Hannibal, N. Y. field, Stockton, Calif.; By J. M. Scofield Stockton, Calif. First Prize, $20 OR eight years I have run a pump and__—- well - digging tools with my Overland. On the way to and from jobs it pulls a four-wheel trailer loaded with from 2500 to 3500 pounds of digging tools and casing, and does it at from 15 to 20 miles an hour. To raise the derrick, I attach guy ropes to the front of the car and back it up the proper distance. The crankshaft is ex- tended to the front of the radiator, and I use a pair of bevel gears and a short shaft to run the belt pulley between the chassis and the front wheel. The belt then is run to the derrick pulley. A friction plate is used in hoisting tools, pumping sand, drilling, and lifting full augers for emptying. If the belt gets loose, I place a jack against the front axle and push the car back until the belt is tight enough. When I am through for the day, I throw off the belt and go home. When the car is not serving as a stationary engine, I loosen the boxes and pull the bevel gears apart. ging outfit. The belt pulley does not interfere in the least with turning the front wheel. My car, I believe, can be used to drive any belt-driven machine that does not require more than 27 horsepower. Ss j. M. Schofield, of Stockton, Calif., using his Overland car to operate a well-dig- The engine also raised the derrick shown in the upper photograph By E. W. Tee, Brooklyn, N. Y. Second Prize, $10 yy staying near a lake in the country last summer, we began to experience a shortage of spring water. -} ae ans | EO SE a to aon oe ES PEE armas How Samuel D. Lamis, Hannibal, N. ¥., used his car in place of a.team to mow the hay. The inset shows how the car of E. W. Tee, Brooklyn, N. Y., pumped water from a lake to his hillside cottage With careful manage- ment, the supply seemed to be sufficient for drink- ing purposes, yet we had to find some means of providing ourselves ‘with water for washing and other household uses. We were some distance from a lake, and we could easily see that it would be a tiresome job to carry up water every day to the house, which was situated halfway up a hill. Finally, we decided to try to use our old Oak- land to supply the power to pump up the water. This proved to be entirely satisfactory, and more than came up to our expectations. A tire was removed from the rear wheel, and the rear end.of the car was raised by strapping it to a long pole driven into the sand, thus permitting the rear wheels to revolve. A temporary belt was made, and power thus was obtained to drive the pump that easily.supplied all the water required. By Samuel D. Lamis Hannibal, N. Y. Third Prize, $5 A FEW weeks before my hay was ready to cut, at the close of a long, dry season, several heavy rains started the grass growing at the bottom. When I came to cut the crop, I found the grass at the bottom so thick that the team could not keep up a sufficiently strong and steady pull. So the knives kept plugging up every few feet. I decided that probably my 1911 Buick had more pep than the horses, so I put a stub tongue on the mower and hooked it to the car. A man rode the mower and I drove the car. After a very short time of experiment, I knew I had solved the problem. The field was stony in places, and a part of it had a 10 per cent grade, but neither handicap seemed to affect us. I did not have to stop once for plugged knives and I cut the field much quicker than I ever did with the team, even when the hay was easy to mow. I ran in low all the time yet the engine did not heat up any more than a tractor. ————E i es eee ——— —

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a Every Snow POPULAR SCIENCE MONTHLY flake a Master Design Lace Makers, Jewelers, and even Bakers now Copy Photographs of Cloud-Born Crystals as Patterns for Ther Wares By Wilson A. Bentley, World’s Foremost Snowflake Photographer NVENTIVE man has learned to im- | prove on Nature’s processes in count- less ways—in the production of larger and better crops; in turning the energy of streams and waterfalls into electrical power to give him light and to run his factories. Yet in one field Nature never has been surpassed. That is in the production of beauty. Nature is the master artist. Man can only copy crudely the patterns she de- signs in infinite variety. And nowhere is this supreme artistry more marked than in the tiny snow crystals that fall in countless numbers from the dark snow clouds of winter. For 41 years I have been studying and photographing snowflakes; yet QS tals are formed. Minute variations of these lower temperatures definitely alter the forms that water assumes when it enters the solid state. To this fact chiefly is due the marvelous diversity of snow- flake patterns. Thus, the natural form of the water crystal—ice—is a triangle. Snowflakes, however, rarely form in this design—only at unusually low temperatures when the molecules of water from which the snow- flake forms is transformed slowly into the solid state. When the freezing tem- perature is higher, the molecules become a solid more quickly and tend to assume a branching form. Almost invariably this form will be some variation of a six- pointed star. even now, each new snowfall adds thrilling interest to my search for wonderful new forms of beauty. I think that is be- cause in all those 41 years I never have found two snowflakes exactly alike. Think of it! Every time I focus my camera on a snowflake, I do so with the knowledge that I am _ recording an intricate and beautiful design that never before existed in the world! Thrilling but Practical This unending thrill of new discovery always has been ample reward for the time and labor I have spent in pursuing my hob- by. Yet in recent years added interest and fascination have come through the fact that my study of snowflakes and the photographs I have made of many hours at a time. A Hobby that Never Grows Old NTIL I was 16 years old, a snowflake to me was just a snowflake,” says Wilson A. Bentley, relating how he first began to pursue his fascinating hobby of photographing crystal gems from the sky. people, I thought snowflakes all were alike, except that some were larger than others. Then my parents gave me area. For example, on the east- a compound microscope, and in my search for interesting objects to view through this magic glass, I soon discovered the almost unbelievable beauty of snow crystals. study of snowflakes immediately became my hobby, and it has remained my hobby ever since.” Mr. Bentley is a farmer. “Like most The southern His home is in Jericho, Vt. Here during his spare hours in the winter he makes his remarkable photographs, often working out of doors In recent years, with a growing demand for his snowflake pictures by manufacturers, designers, and scientists, his hobby has developed a financial value; yet he has been content to let his work among the crystals remain a pastime and to draw his livelihood from his farm. During the 41 years he has followed his unusual hobby, he has photographed more than 4000 snowflakes—and never has he found two of them exactly alike. Meteorologists especially have become interested in facts re- garding the nature of snowfalls which my work has ‘revealed. For one thing, the forms of the crystals vary remarkably, al- though not by definite rule, in different portions of any storm ern edge of a storm, columns and plates often are prevalent; the portion produces branching stars and sometimes sleet and granular forms; the center portion, granular forms; the western section branching stars and plates, and the north- ern part columns and plates. When Stars Are Formed Medium to rather scattering snowfalls, rather than heavy storms, produce the most beau- tiful forms. Branching stars them have found practical use- occur most often during mild fulness in industry and in scien- tific research. Incidentally, my hobby has developed a real financial value. For example, a lace manufacturer dis- covered in my photographs of snow crys- tals an opportunity to copy their original designs in the manufacture of his product. He bought a number of the photographs from me, and from them fashioned lace in the patterns that Nature, the master artist, had formed by hurling tiny drops of water through the winter air. Next, a jeweler realized the possibilities of imitat- ing my captured snow gems in gold and precious stones. Wallpaper designers, makers of silks and other fabrics, metal workers, wood carvers, manufacturers of glass and chinaware—all have purchased my snowflake photographs for use in pat- terning their wares. And recently I sold some pictures that are to be used as models for cookies! The fact that no two snowflakes ever are alike, or ever can be alike, in form and texture is one of Nature’s great wonders. Yet by close study of the formation of these crystals, science explains why this isso. Each of the minute crystals of water vapor that fall as snow takes its individual crystalline form from a definite combina- tion of atmospheric conditions that it en- counters as it falls—such as temperature, density, wind movement, and electrical content of the air. Temperature, of course, is the chief factor in producing snow. Every one knows that water alters its form according to its temperature. At ordinary tempera- tures it is a liquid; at high temperatures it becomes a vapor—steam; at low tem- peratures it becomes a solid—ice. Even when water is in the fluid state, the nega- tive and positive poles of its molecules tend to arrange the molecules into crys- tals. At the higher temperatures, how- ever, these molecules dart about under the influence of heat, making it impossible for their poles to hold them in crystal form. When the temperature is low, though, the water becomes quiet. Then the poles draw the molecules together and the crys- weather, while plates and col- umns fall generally in cold weather storms. It is astounding to find that in zero weather tiny bits of water from 1/300 to 1/4000 of an inch in diameter exist in the clouds in a fluid state. Even more amazing, I have found these droplets to contain a crystal core, covered by a film of fluid water. Why these tiny bits of water fail to freeze in the coldest weather of winter is a mystery of cloudland to puzzle the keenest scientific mind. Hardly iess interesting is the evidence contained on some of the snow crystal faces that certain portions of them also once were covered with fiims of fluid water that later crys- tallized in the typical scalloped, rounded form characteristic of massive ice crys- tals. Some falls of snow have yielded as many as 50 beautiful pictures; others none atall. In all, I have made more than 4000 photographs, and each winter I return to my hunt with undiminished enthusiasm.

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CCW WS s WH Uj Yi, Y Y N . ——— a eee a

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BT AS Y ‘ ar AS LN bo Ih on 46 POPULAR SCIENCE MONTHLY The Sports You Need Most For Every Job there’s a Recreation to Keep You out of Ruts By C. Ward Crampton, M.D. National Authority on Recreation and Health fatal of all diseases. The winning of success demands intense concentration. It means that a man must put his whole self into his work. In pursuit of success he takes himself out of life; he not only gets into a rut, but the ruts get into him and wear him down. I have in mind an old boyhood friend who, from the day he left school, em- barked on a spectacular career that in a few short years carried him to financial independence. The other day I ran across him on the street. It was the first GS tata of can become one of the most : time I had seen him in 15 years. I hardly recognized him. His face, once tanned and boyish, had become the color of putty. His once handsome features had assumed a hawklike sharpness. Deep lines marked his forehead and gave a drooping twist to his mouth. A One-Sided Man We talked of the years that had sepa- rated us. “Doctor,” he said, “I have given every- thing I have to get where I am. I have worked night and day, year in and year out. And yet, do you know, now that I have all that I was after, I’m not happy. I don’t enjoy my food. I can’t sleep well. I don’t enjoy the company of others. All I can think of is my business. What’s the matter with me, anyway?” There was a certain tragic look about him. “T know what’s the matter with you,” I told him. ‘“‘You remind me of an auto- mobile wheel spinning in the mud. The faster you go, the deeper you sink in the rut. And if some one doesn’t hurry with a derrick, you’re going to get stuck so fast you can’t budge. The trouble is you’ve forgotten how to play. What you need is to get out for some fun and ex- ercise.”’ All of us who are interested in our work, and are eager to succeed in it, are in con- stant danger of falling into the same kind of rut. And the way to get out is to re- establish the balance of life that has been overturned by too much concentration. It is the opposite of concentration—it is recreation. Those who do not re-create themselves dry up like mummies, wrapped in them- selves, all dusty and shriveled inside. They are half dead while they are alive, and they die early. As a New York physician declared recently to a patient: “It is a case of recreate or wreck.”’ There are, of course, many kinds of recreation, and the kind that may suit you may not be suitable to your neighbor. But you will go a long way toward making a correct choice if you pick for your recrea- tion some form of activity that is abso- lutely different from your daily work. If your work is mainly muscle work, find some mind-testing recreation, and play some game that makes you use your muscular equipment in some entirely different fashion. If your work is mainly with your head, turn to vigorous muscular activities. If you work indoors—go out. If you are out of doors all the time— like the postman or the structural iron- worker—stay inside. If you sit or stand at your work, walk, run or dance for recreation. If you are continually meeting many people, seek seclusion. If you work alone, seek congenial com- pany. Keep Yourself Well Balanced If your work is quick, intense, and ex- citing, seek quiet. If it is dull and monotonous, find some activity that is rapid and intense. If you have a white-collar job, put on a flannel shirt. If you have a flannel-shirt job, a white collar as a change may have its merits. Change your clothes, change your mind, change your attitude—but, above all, get the play spirit. Nature has pro- vided us all with a desire to get into the game. Some of us feel that we may have lost that desire. Games, particularly of the athletic type, employ the whole mind, body, and emotions. “a ae He needs basketball to make him run and jump, to knock him around ruth- sessly with other men He needs to rough it out in the open; to learn how to enjoy a roaring campfire sire One) He needs to spend his week ends in the woods on the shore of lake or river, to learn all about the world out of doors f UML All tired out—the office man taxes his brain, using few muscles % Ry Sketches by Dector Crampton % "= X24 He needs to play baseball for outdoor fun and vigor- ous, exciting exercise Chopping wood will strengthen his muscles, his lungs, and _ his heart Mountain climbing will take him away from his worries and re-create him mee “dS sb Qe or 0 & Se Se +t 5 - o£

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<x = oo ‘oo ir Te 1e ye of d,

He needs handball to loosen up his stiffened joints and limber his unflexed muscles He needs boxing for rapid, exciting, and vigorous exercise

A quiet game of check- ers develops his brain POPULAR SCIENCE MONTHLY

47 He needs bowling to straighten’ his back ma) Reading an exciting adventure story stirs his blood and fires his imagination

He needs to go fishing to relax his tense muscles

The flannel-shirt man works indoors at a job that requires taut muscles Take the man in an office job, say a clerk 25 years of age, who has sedentary indoor work eight hours a day, in an office where he sees only three people— the boss, the stenographer and the office boy. What is the one best recreation for him? Basketball makes him run and jump. It takes him out of himself and throws him (sometimes violently) among his fel- lows. His daily work is quiet and un- eventful. Basketball is full of excitement. His work uses only a few muscles in the body. Basketball uses them all. and spend the week-end in the woods, in- dependent of a hotel, has taken a big stride toward becoming a real, all-round, full-grown man. All this applies especially to every man who works indoors and does not employ his muscles vigorously — the school teacher, bookkeeper, clerk,. salesman, editor, executive, manager, buyer, broker, or banker. Suppose you are a machinist. Your job calls for constant application, requiring a good eye, steady hand, and taut muscles. indoor season will be either boxing or wrestling. Go to some gymnasium where you can get good instruction and see clever work done. Learn these manly sports from the ground up, for boxing and wrestling are the greatest of all-around man-making games, and belong in every man’s life. If you want to be a well-rounded man physically and mentally, you need to develop the other side of you. It is a good thing occasionally to give the mus- cular equipment a rest for an evening and sit down to a quiet game of

He can sit at his desk for the whole day and not be much more than a neat, tidy automaton. Basketball musses him all up, brings out his virile qualities, makes him a shout- ing, vigorous man in action— every fiber of his being on the job. Sleep—a Health Builder

RE you ‘‘all in’? when you go home at During the daytime are you pursued by the “‘tired feeling”’ that robs work of its zest and deadens am- bition? In an early issueof POPULAR SCIENCE MONTHLY, a noted health authority will ex- piain the scientific secrets of fatigue and will tell how you can conquer it. night after the day’s work? chess, checkers, or cards. These help to develop a useful part of your anatomy—your brain. Reading that Stirs the Blood For the vigorous, active man, who is tired at night, there is no finer recreation than occasionally stretching out in an easy chair

Moreover, he gets a shower bath and a rubdown afterward, and he comes out of the gym tired, glowing, and stimulated, ready for a solid night’s sleep of perfect reconstructive repose. He has been re-created. Baseball, tennis, handball, boxing, and wrestling, too, are good choices. All sup- ply the vigorous exercise and stimulating ‘sport that the white-collar man needs. But aside from competitive games such as these, an ideal source of recreation is out in the woods, under the skies, along the shore of some lake or river. If you are a white-collar man, learn how to walk and become a hiker. Find a lake in your vicinity. Make your camp and cook your supper on the shore, skate there or swim, according to the season. The man who can start off with a pack on his back When you get through, you are tired. Your muscles are cramped. Your back is bent over. The chances are it will stay that way, for it obeys the general law that the body structure assumes the position in which it is most exercised. I have seen hundreds of men who have been engaged in mechanical work for years. They become strong, but hard and stiff, and stiffness is just another kind of weakness. You need, if you work at one of the manual trades, a thorough livening-up. to overcome this hardening process. Your game is handball. It is interest-~« ing, rapid, and vigorous and will loosen up any or all of your joints when the rivets tend to get rusted in. Your next best recreation during the and reading an exciting story of romance and adventure. This stirs his blood; makes him thrill with the dan- gers, struggles, and victories of fiction, and he participates in stirring events that he could experience in no other way. Similarly, you can find enjoyment in watching others play when you yourself cannot play. If you cannot play baseball, go see a good game once in a while and “root’”’ for one of the teams. Knock ’em “over the fence’ with Babe Ruth. If you can’t go to a game, follow the fortunes of your favorite big league team through the season. If you are interested in tennis, follow it up. Go to ‘ the big tournaments. Get into the game. Recreate. It holds big profits for you. aa .

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POPULAR SCIENCE MONTHLY I Ave 8 ‘ Aye Oye AN ‘ #2 to én . * * ae Re f - , MAD ous HEN a barge loaded with freight cars struck a buoy near the Queensboro Bridge, New York City, re- cently, the cars were plunged into the DERRICK LIFTS CARS FROM RIVER East River. The photograph above shows how the cars were lifted one by one from the water by a giant derrick mounted on a huge barge anchored in the river. Handy Envelope Is Sealed by Postage Stamp A SELF-SEALING envelope, easily opened, has been invented by Ervin W. Weigand and Arnold B. Ogden, of Jefferson City, Mo. To the flap of the envelope, which is at one end and which folds over the face, is attached a small tab. This is inserted beneath two other tabs at the upper right-hand corner of the envelope. — When the stamp is pasted over these joining tabs, the envelope is sealed. To open, it is necessary merely to pull a tab attached to the flap and projecting be- neath the edge of the stamp. POWER SAW CUTS ICE IN SQUARES POWER saw for cutting ice has been designed by a New York manu- facturer to replace four pair of horses and six men. Power from a four-cylinder gasoline engine is transmitted to two vertical circular saws at the rear through a series of gears and a universally con- nected shaft swiveled to swing vertically. ~ How the power saw cuts the ice into checkerboard squares The operator, standing on a frame in _ front, keeps the cutter in line by following the previous cut with a guide pin. The friction of the saw as it cuts its way through the ice serves to move the machine for- ward on its run- ners. After the entire ice area has been cut in checker-. ' board fashion,-the: machine is_ re- moved and work- men armed with picks and ice saws break off the cakes. Pistol Welding Torch Is Released by Trigger HIS oxy- acetylene torch shaped like a_ pistol, with a trigger release, was in- vented in Ger- many. It is rug- gedly built, so as to eliminate all danger of escaping gas. Out - of- the- way corners that are inaccessible to other welding torches can be reached easily by this compact tool, it is claimed. a New Automatic Sprinkler for Fire Prevention 8 geenarepigiciid of a new type of auto- matic sprinkler head is accomplished by a liquid that is sensitive to heat. It has been developed for fire prevention in- stallations and is said to be non-corroding and more sensitive to heat than the older types. The thermally responsive part of the new head is a silica bulb nearly filled with a red liquid. As the temperature rises it expands the liquid. When a predeter- mined temperature point is reached— usually about 135° F.—the bulb bursts under the pressure. Normally, the bulb is so adjusted as to hold a glass valve against the water inlet. When the bulb bursts, the valve flies off, allowing the water to flow. Heretofore, solder heads have been used exclusively, because solder melted at a lower temperature than did any known alloy strong enough to keep the sprinklers SCREW HOLDS VALVE DOWN _ SILICA BULB eiQuid EXPANOS AND BURSTS BULB AT.135° GLASS VALVE FLIES OFF ALLOWING WATER; TO FLOW Bursting of the sensitive bulb releases the water inlet valve, allowing the water to flow watertight. The new head, operating on a fundamentally different releasing prin- ciple; is Said to be effective at much lower temperatures, attacking fires earlier. The first industrial plant to install the new heads is the Thomas A. Edison fac- tory at West Orange, N. J. They areina room where celluloid cylinders are stored. ha col

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Is ther asily er uto- shed It n in- ding yider the with es it eter- ed— ursts as to inlet. s off, been ed at nown iklers jos URSTS \T. 135° ATER} ; the flow ing on > prin- lower all the n fac- reina stored. .winter than they are in summer. New Bottle Stopper Pours Specified Quantities N INGENIOUS bottle stopper that pours an exact quantity—from one to five teaspoonfuls—into an attached container is a recent household conveni- ence invented in France. To pour this quantity a second time, the bottle first must be placed upright. Hot Bottle Heats Itself when It Is Needed ESIGNED for household conveni- ence, a new hot bottle, filled with a harmless chemical instead of water, stays cold, it is claimed, until you need heat, and then _ be- comes hot al- most immedi- ately at a slight manipulation of the stopper. Boiling the bottle charges it with heat. The bottle then cools, while the chemical con- tents hold suffi- cient latent heat to meet any need for a hot-water bottle. It can keep food warm on a motor trip or, when no heating device is handy, re- main cool until heat is needed. Since it is built of metal, it cannot be punctured, and it is said to be more durable than rubber. Skyscrapers Shrink in Winter, Tests Show EW York skyscrapers are from 1 2/10 to 1% inches shorter in mid- This fact has been revealed as the result of a study of skyscrapers recently made by the planning service of the National Asso- ciation of Building Owners and Managers. The figures were arrived at by calculating the expansion and contraction of steel. In the Woolworth Building it was found that each degree change in temperature makes a difference of .061 inch in the structure. POPULAR SCIENCE MONTHLY 49 OUTDOOR SWING AND BED Con | ae the person who enjoys the out-of- doors in winter this combination swing and bedroom has been devised by Bernard H. Witte, of Chicago, Ill. A glass frame completely incloses it. A portion of this frame behind one of the seats may be swung outward, while the back of the seat ean be swung to a horizontal _ position, forming an extension for a bed. The adjustment for either bed or swing can be quickly made. Showing how one seat of the glassed-in swing (at the left) is swung out to form a floored extension for the bed Sensitive Fire Detector Sounds the Alarm HIS remarkable fire detector, actuated when the temperature in any part of a building it protects reaches a 106° Fahrenheit, indicates on a central switch- Pincushion Attached to Sewing-Machine Arm INS have been made convenient to the fingers of a housewife operating a sewing machine by a doughnut cushion encircling the arm of the machine. It is not necessary to turn about to find a pin or to leave a cushion exposed where the forgetful hand may be pricked. By means of an inconspicuous slit in one side, the cushion can be slipped easily over the machine arm. It does not at all impede the opera- tion of the machine. The fire detector, showing alarm signals board the exact location of the danger point. Simultaneously it sounds an alarm bell at the switchboard and one at the nearest fire station. A white control light burns constantly on the switchboard. Should this light burn out, or should a wire break or a con- nection get out of order, a distinctive trouble alarm is sounded. . This, of course, is heard only at the switchboard. When the temperature reaches 135 de- grees, an alarm is sounded loudly outside the building and the word “Fire,” illumi- nated through red glass, calls the neighbor- hood’s attention. ae, tas 4 = = Honey Prevents Freezing A MIXTURE of honey and water in the radiator of an automobile will prevent freezing in winter, according to experimenters at the New York State College of Agriculture at Ithaca. Cushion within easy access of seamstress

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ER RCT eg Sy ig ROI PRS oe ig oy TS ee ae SE SI a Ee ee a 50 Oddities in the News — THE SMALLEST MONKEY IN CAPTIVITY Born in the jungles of Brazil along the Amazon a full-grown, healthy marmoset, He is the smallest monkey in captivity, and is the pet of Miss Ruth Clifford, River, ‘“Paradox,”’ weighs only four ounces. of Los Angeles, Calif., who is shown at the right holding him on her wrist. ‘“‘Paradox”’ is just three years old. Grapes and figs, to which he became accustomed in his Brazilian jungle, are his favorite foods. Every day he consumes his own weight of them. Like all marmosets, he is extremely POPULAR SCIENCE MONTHLY sensitive to cold. CUOMO MM ip DEER BEGS A MEAL When winter snows lie deep, the American white- tailed deer often visits the outskirts of city or town in search of food. Above is a typical scene in Du- luth, Minn., where the deer become so tame as to beg meals from doorsteps of suburban homes RWW WW y ; : : % ties. caps = wo 48 x * . SN s WN x SAN meeeereeeennnnrrrenteuereeereete ig } } RANA ANY HPN é ae 4 | | , hk; E | ni rae \ , § N Z } N om MMQMHWWOA WOW wD WN WH Ia eS I Ee a Me CMM MANN SOOWOVWW WWW Wy THE SKYSCRAPER OF THE FUTURE, designed by Helmle and Corbett, New York architects. The building, occupying a city block, will be composed of units rising to a 60-story, 1000-foot central tower NEW THRILLS FOR SKATERS Made from a bicycle frame, a motor wheel, and a pair of steel runners, the ingenious shown at the left offers new thrills. Propelled by the friction wheel driven by a small motor, the machine scoots over the ice at 30 miles an hour, pulling the skaters. tion of Thomas Avoskin of New York motor-skating machine It is the inven- Z a NEW AIRCRAFT GUN The newest development in airplane armament is this unusually flexible Browning 30-caliber ma- chine gun. It is mounted on a specially designed revolving mount that en- ables the gunner to train the weapon in almost any desired direction or angle

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tor the ine lis. ble DYNAMITING AN ICEBERG A boat crew from the United States coast- guard cutter Tampa is shown here pre- paring to dynamite a huge iceberg that has floated into the path of the trans- atlantic shipping lines, menacing navi- gation. Dynamite mines were inserted in the great mountains of ice and ex- ploded by a fuse after the crew had gone — A PERISCOPIC MIRROR No blemish of make-up escapes the woman who is armed with the hand mirror shown above, displayed at a recent perfumery exposition in New York. This triplicate mirror reveals the hang of the owner’s earrings, the arrangement of her back hair, as well as the amount of powder on her nose POPULAR SCIENCE MONTHLY FORD CROSSES U. S. IN EIGHT DAYS Record time for a trip across the United States in a Ford is claimed by F. G. Gegoux, who recently drove from Los Angeles to New York City in eight days and six hours. Gegoux is shown above standing beside his mud-spattered car. Note the special roadster body, de- signed to give protection from the severest weather USES MOTORCYCLE AS DELIVERY VAN Delivering a seven-piece dining- room suite, all loaded on his motor- cycle side car, is just one small item in the daily business of H. Farrar, a furniture dealer of London, Eng- land. Finding that the slow moving van and delivery wagon were not speedy enough for his trade, he re- inforced his side car, strapped the goods on top, and drove away. After using this method of delivery for 18 months, he says it’s a real economizer of time and money eevectncenrnitemasntheansitcariigaantttaat eaten tt eee —————— eapenmcncemte erence racers At eben CELA IAL

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52 POPULAR SCIENCE MONTHLY ei a a “7 invention of Above: The sea sled, driven by air propeller, skimming the water at a speed of nearly half a mile a minute near the Naval Air Station at San Diego, Calif. This flat-bot- tomed craft draws only eight inches of water. Installation of the airplane engine and propeller is shown at the left _ SOLVE the problem of rescuing disabled airplanes that frequently are stranded on mud flats near the Naval Air Station at San Diego, Calif., naval officers invented the ingenious sea sled pictured above. So shallow is the water above the flats that attempts to use ordinary speed boats to reach stranded planes were abandoned. Approach on foot through the soft mire was out of the question. The hull of the new sea sled resembles SEA SLED RESCUES STRANDED PLANES on a large scale the aquaplanes used in water sports. Its draft is only eight inches and therefore it can maneuver in water less than knee deep. The craft is driven by an airplane en- gine and propeller mounted at the stern. The pilot’s cockpit is immediately in front of the engine. Six men can be carried on this sea sled. Skimming over the surface of the water, the boat is said to have attained a speed of 29 miles an hour. HUGE GRAIN TRUCK HAS SIX WHEELS A SIX-WHEEL motor truck, built, by a firm of millers in London, England, has a capacity of 448 bushels of grain— about 1314 tons—yet it can be loaded by one man in half an hour, or unloaded in 20 minutes. This huge vehicle, which has a body length of approximately 22 feet, averages 60 miles a day in three trips back and forth between a London dockside and the firm’s flour mills. It is loaded by gravity through the distributing hose from . Sages OE GRAIN LOADED : : THROUGH TOP, porting sacks by rail. the granary floor overhead, and is dis- charged through three chutes beneath it onto an underground conveyor at the mill. The body is constructed with slant- ing sides to prevent any particles of grain from finding permanent lodgment. The giant truck has been in operation only a few weeks, but its owners say that already it has effected a considerable saving in labor and transportation as compared with trans- J ss DISCHARGE CHUTES The six-wheel grain truck, showing the narrow opening at top through which grain is loaded, and the discharge chutes below. The body is 22 feet long, with a capacity of 448 bushels Movable Hammer Claws Have Vise-Like Grip HIS carpenter’s hammer, with mov- able, vise-like claws, capable, it is said, of pulling the most stubborn, head- less nail, is the George Ainsley, of Long Beach, Calif. In gripping a nail, the claws, pivoted 1% inch from their ends, spread apart when pushed toward the handle. Then, when they are straightened by a pull on the Pushing the hammer handle, they claws spreads them are forced into to grasp the nail the wedge- shaped opening of the bearing shoulders, tightening the hold on the nail in propor- tion to the force required to draw it. A spiral spring in the head straightens the claws when the nail is removed. The jaws, if damaged, may be replaced within a few minutes. Litter Carrier Saves Time on Dairy Farm O LIGHTEN one of the most dis- agreeable of farm tasks and increase sanitation on his dairy farm, George Benson, of Cambridge, Wis., has invented the movable litter carrier shown above. Into the gutter of the cow barn fits a series of steel troughlike pans. These are lifted by a chain hoist and carried on an overhead track to the manure pile. There the pan is tripped automatically and dumped. The carrier rod telescopes to four feet, making it adjustable to pans of widely varying lengths. The simplicity of the invention is said to place its cost and its upkeep within reach of even the small » dairyman. It is claimed that the invention accom- plishes a saving of one third in time and three fourths in labor, besides assuring greater purity of the milk supply.

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yv- is ad- ers, JOr- the ced ne dis- ease orge nted Ove. its a e are nan ‘here and feet, idely f the id its small com- » and uring Spring Clamp to Prevent Rattling Windows INDOWS that rattle in the wind all night are said to be silenced by this newly patented combination sash holder and win- dow lock. The device also makes it more difficult for a burglar to en- ter. The sash can be lifted to any position and there securely held by two clamps that press tightly against the win- dow frame. A slight pressure on the handles of the spring catch releases the grip of the clamps. Brush Holder also Serves as Sanitary Cover SANITARY metal cover for the household brush is provided in a combination brush holder and case in- vented by A. H. and D. A. Wolf of Philadelphia, Pa. When the brush is not in use, the case, which has one open side, covers the bristles. When the brush is in use, the case serves as a back, the bristles being exposed in the open side. In reversing, the brushes slide on small tracks along the inside edges of the cover. Adjustable Last Designed to Fit Any Shoe Fitting the adjustable last to a shoe HE adjustable shoe last shown here is the invention of Hans Gafner, of Escanaba, Mich. In addition to being adjustable to the length of the shoe, as are many types of last, it is split longitu- dinally so that it can be compressed or expanded for adjustment to the width of the shoe as well. POPULAR SCIENCE MONTHLY 5 % % 4 X x + aa \ ve x ‘alee \\ Np 2 Above: Modern copies of Stradivari violins undergoing sun-drying process. At right: Applying the special varnish to the violins World-Famous Violins Copied by Scientist Se science at last appears to have rediscovered the secret of making super-violins—a secret that was understood by Stradivari and other old masters of the seventeenth century, and that was buried with them. Professor F. J. Koch, physicist and musician of Dresden, Germany, is re- ported to have duplicated world-famous Stradivari violins so successfully that in recent tests a group of Italian musicians was unable to distinguish between their tones and the tones of his instruments. After a searching analysis of thin wood sections from the works of the masters, Professor Koch concluded that the secret of their tone lay in imparting an artificial uniformity to the wood. A violin is like SILK TUBE SERVES HUMAN bodies shooting to safety through a tube of silk from the upper stories of burning buildings! Such an improve- ment over the fireman’s life net is said to be embodied in a life-saving tube perfected by a Cleveland, Ohio, in- ventor and _ successfully tested in that city. The tube is of balloon silk, ineased in heavy netting. The upper end is affixed to a window of the burning building, the lower end held by firemen in the street. The person being -res- cued enters the tube head first, and slides through it to the street, the speed of the descent being regulated by pulling the tube taut or permitting it to be- come loose. EARTHWORMS—th ough their brains are in their abdomens—have memory and can be trained to go in a specified direction, says Prof. L. Heck of the University of Prague, Germany, after a series of experi- ments with 500 worms. Loti B A a bell. Its material must be uniform throughout to produce the “‘deep” tones that are pleasing to the ear. If its wood contains small bubbles, pores or minute cracks, it will produce discordant tones. Since no wood in its natural state is entirely uniform, Professor Koch set out to rediscover the method of making it so. His clue to the secret lay in a peculiar, transparent substance he found in the pores of the wood from the Italian violins. This discovery fitrally led to an oil treat- ment which, combined with months of sun-drying and a special varnish, is said to have produced his remarkable results. AS FIREMEN’S NET The person being rescued shoots head first to safety through the silk tube ee

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ELMAR Se RE BRS A ee ge Be Sate ee POPULAR SCIENCE MONTHLY S pies PRIZE COW roar ON WOODEN LEG HIS cow, ‘‘Fanny,” was the champion milk producer of the whole county in a farming section of Illinois until an injury to one of her legs resulted in an infection which for a time caused her owner to fear it would be necessary to destroy her. A local veterinarian, how- ever, amputated the affected leg, and then supplied “Fanny” with the wooden leg which she is wearing in the picture. ONE RAM GIVES 25 POUNDS OF WOOL ONE of the largest: clips of wool ever taken from a single animal, 25 pounds, was shorn recently from this ram at Santa Cruz, Calif. The illustration shows the animal just after the shearing was completed. He is a registered Ram- bouillet of the long hair variety. WHEEL CHAIR DRIVEN BY DOG MOTOR jnsSocaniouna’ - a ib naadenaadessa! eo ‘THs unique dog - powered wheelchair at- tracted much at- tention when it appeared recently on the beach walk at Ostend, Bel- gium. The photograph seems to indicate that the canine motor neither re- sented nor suffered under the appar- ently strenuous task imposed by his crippled mas- ter. This Blind Carpenter Has Built Six Houses F evn ne totally blind, John Tay- | lor, of Canton, Ohio, is a successful carpenter. For 28 years he has been un- able to see the hammer he works with; yet in that time he has built six houses. His infirmity, dating from his early youth, never has prevented him from hitting a nail squarely and soundly on the head, a feat that is beyond many a man with perfect vision. He now is finishing an addition of six rooms to his home, and is said to have done every piece of the work himself. He even laid an additional length of cement walk for the home that he recently enlarged. John Taylor, blind carpenter of Canton, Ohio, can hit the nail on the head every time Bicycle Sidecar Becomes Popular in Germany HE average pair of legs feels that pedaling two bicycle wheels and a rider is a sufficient task. But in Berlin, Germany, where the cataclysmic collapse of the mark has made street-car rides prohibitive luxuries for thousands, the bicycle sidecar has been born of necessity and is a common sight. A two-passenger bicycle in Berlin By | cou not tior acti fro! wit abc

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as Pay- ssful un- rith; arly rom the man 1ing and the onal that |} should have been spread over the sur- POPULAR SCIENCE MONTHLY 55 | Better “sous with Less Fuel By Orion O. Oaks, M.E. BURNED four tons of | coal last month in my seven-roomed house and could not keep warm. If I had not used two oilstoves in addi- tion to the furnace, my family actually would have suffered from the cold. I am at my wits’ end to know what to do about it.” A Common Problem In this way a friend of mine recently presented his home- heating problem to me—a problem that confronts more than half the home-owners of the country. An inspection of his hot-water heating system revealed the fact that there was absolutely nothing wrong with it. Even his coalbin was filled with the proper kind of fuel. Imagine his surprise when I demonstrated to him that thetrouble Ne se FRESH COAL lay not at all in his lth eal equipment, but entire- Z77gstesV/p ly in his ignorance of how to take care of his furnace. His practice had been to go down to the cellar in the morning, open the damper and all the doors of the furnace, then shake the grate until the hot coals fell into the ashpit; finally, to throw in a few shovels of stove coal. Often the fire went out. At other times he could get up no heat until late in the morning. What he should have done was to shake the grate just once or twice to remove the packed ashes and allow air to pass through. A few shovels of coal then For mild weather face. This would have ignited in a few minutes and started steam. When fully ignited, the firebox should have been filled with fresh fuel. Smothering the Fire Shaking the grate too much when starting from a banked fire causes the coals to fall together and clog the air passages between the coals, stopping the draft. Since there is little fire in the morning, it cannot break through sufficiently fast. Either the fire suf- focates or it takes too long to heat up, especially when large coals are used. Another difficulty often encoun- tered is due to improper care of the fire during the day. Some persons throw in a few shovels of coal every hour or two in the belief that such a method is economical. As a matter of fact, it actually wastes fuel, causes more work, and decreases furnace efficiency. After the fire has been well started, the firebox should be filled with fresh fuel until the top layer of coal is halfway between the top and bottom levels of the fire door in the center, ~ FILL GAGE To get better heat with less fuel, keep the firebox full. Don’t put on the coal in the middle of the fire door, as shown above. Insets show how the fire should be regulated for mild and for very cold days sloping down at the front so that the coal will not fall out when the door is opened. With such a mound of fresh coal on top and a bed of live coals extending to within about two inches of the fire door, TO WATER = LINE In steam and hot- water furnaces it is important to keep the water at the proper levels. Lack of water results in poor circulation and the danger of burning out the boiler. The steam plant, above, should be kept full to the water line. In the hot-water system, at right, the dial pointer should indicate “full” the fire should burn without ad- ditional coal for at least eight hours on aseverely cold day, and as long as 14 hours on a mild day. During this interval only the grate will require attention. On a mild day a layer of ashes as deep as six inches may be maintained. This will hin- der rapid combustion and sup- ply just enough heat to keep the chill out of the house. Ona severe day, however, the ashes should be kept down to a mini- mum, never allowing more than an inch or two to accumulate before shaking the grate a little. Shaking every three or four hours should be sufficient. Leave the Damper Open When shaking, leave the smokepipe damper open, close the check draft and draft door in front of the ashpit. Never 2 Lee poke hard coal fires So EE from above. Shaking ie the grate will split the Jo uvecon, surface sufficiently to eater allow the fresh fuel to me fall among the live ASHES driblets. The top of the coal should reach SS ee coals. For banking at night, shake out the ashes and fill full of coal, then close the damper after allowing a few minutes for free gases to ignite. All this applies equally to steam, hot- water, or hot-air furnaces. In all cases you will find that less coal will be used and more heat obtained by maintaining a deep fire rather than a shallow one. An important consideration in steam and hot-water systems is to keep the water at the proper levels. In steam boilers usually you will find a gage with a line marking the water level. For cold weather Why Gage Is Important Should water fall below this level, it will lessen the ability to maintain even heat; should it become empty, you may burn cut the boiler. Too much water, indicated by a full gage, ‘ will allow no room for the steam. Ifa valve is accidentally left open, all the radiators may become full of water, producing no heat and causing con- siderable trouble. In the hot-water heat- ing plants there isagage indicating the amount of water in the system. A fixed pointer indicates “full,”’ and a movable pointer shows the actual amount. Before start- ing a fire, be sure that the system is filled. In hot-air furnaces, where pipes are used, difficulty in heating may be due to the fact that air is not drawn into the system from See Ce ee SS a een EE ie a a ST Eee ee F a es

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& & e y a sad eaby diana tee ON Von oe & ON 9oois Onin ie Slag k 2 ee sf I TE DOR BENE RE SI a ght Sates A & 3 EP PEA ee 56 the outside in sufficient quantity. The in- take opening should be located on the side of the house from which the prevail- ing winter winds blow. If situated on the wrong side, there will be a suction on the inlet instead of a pressure inward. In pipeless systems the cold air from the house drops through the rim of the single register into the furnace. After it is heated there, it ascends through the center of the same register. Outside conditions do not affect this type of heater as they do the piped hot-air sys- tem, for the air in the house simply is recirculated. POPULAR SCIENCE MONTHLY is impeded. If the hot-air system is not working properly, regulate the intake damper until you get the desired amount of heat in the rooms. Another question that arises is the kind of fuel to use. For ordinary house-heating plants the most satisfactory is stove coal. Other fuel, of course, can be burned Keep the Air Moist In both hot-air types water should be kept in the trough located in the side of the furnace. This will allow the air to absorb moisture to keep the house at- mosphere at a healthful humid- ity. In all systems the furnace and pipes should be kept clear of soot and dirt. In hot-air furnaces there is a door in front of the radiator through which the dirt can be scraped. A coat of soot will pre- vent the heat from penetrating to the heating units, whether day. they contain water, steam, or air. A good practice is to inspect the pipes at least twice a month. You will find that a few minutes’ work will clean out the soot de- | posits. To keep the fur- oa, ‘ons nace working prop- \ erly and to prevent burning out the grate, the ashes should be removed daily. If the ashes are allowed to ac- cumulate so that the pit is full up to the grate, the heat not only will cut off the draft, but How to burn soft coal: Pile the fresh coal in front, allow- “ a ing the burning sometimes will coal to be exposed buckle the grate at the rear bars. Very often all the most perplexing of your furnace troubles may lie in poor draft. Chimney corners filled with soot, - clogged smoke pipes, or a chimney of too small a cross section may be the cause. In any chimney not only strength of draft but quantity of draft is necessary. For that reason it is best to have the necessary chimney area computed by a competent authority rather than to rely on guess- work. How to Control the Draft When a freely burning fire is necessary, the smoke damper should be open, the slide on the fire door closed, and the draft door open. Checking of the draft should be controlled by the damper, allowing just enough draft to supply the proper amount of heat. In the intake pipe of hot-air systems there is a damper to con- trol the amount of air admitted to the furnace plates. Obviously if this damper is tightly closed, the circulation of hot air Clean soot and dirt from boiler flues of steam or hot-water furnace at least twice a month, using a scraper as shown above. Ashes should be removed from the pit every If they are allowed to accumulate until the pit is full or until they touch the grates, as shown at the right, they not only will cut off the draft, but may eventu- ally succeed in burning out the grate efficiently after some nractice. Coke alone may prove difficult, but if properly handled will produce satisfactory results. Large stove coals are hard to use when starting a fire. Buckwheat is small and lies too compactly when burned alone. It may be well to have a special bin of small fuel for starting the fire the first thing in the morning. The use of soft coal involves a problem of its own. In some cities it is not per- mitted because of the tendency to produce smoke, although special boilers have been a designed to eliminate this nuisance to some extent. When burning soft coal be sure not to cover the entire live-coal surface with fresh fuel. Either it will put out the fire, or it may cause an explosion. This is be cause a large amount of combustible gases are formed and do not burn at once, since the small particles of soft coal pack the surface tightly. After a while the fire may break through, ignite the accumulated gases, and blow the fire door off its hinges, Always put the fresh soft coal in front, leaving the glowing coals on top in the rear. Air in the Pipes Even if the furnace is work. ing perfectly and you are tak. ing proper care of the fire, yoy still may have difficulty in keeping the house warm. In a steam system air ac cumulates in the pipes overnight and must be driven out by the steam before the radiators can become hot. For this purpose the radiators are fitted with air valves. If these are not working properly it may be very difficult to heat the house, even though there is plenty of steam in the boiler. A vent valve fitted on the end of the steam main of such a system may help in allowing a _ considerable amount of air to escape. Radiators Must Be Adequate Likewise, in steam and hot-water sys- tems the amount of radiating surface may be insufficient in some or all the rooms; or in hot-air heaters the cross section of the registers may not be great § enough to supply an adequate quantity of fresh heated air. If you have any rea- ‘son to suspect that these are inadequate, call on an expert to compute these values for you. No matter how well you look after the fire, no matter how much coal you burn, you cannot expect to heat your home if any part of the apparatus is too small for its needs. In every type of heating system the smoke pipe should be disconnected from the flue at the end of the season and all soot should be cleaned out. All doors on the furnace should be left open and_ the hinges thoroughly greased. In the case of steam or hot- water plants, water should be left in the system. If you have cleaned and taken care of the system at the end of a season in the manner described, you will only have to spend a few A typical hot-air furnace. Methods of firing are the same as for steam and hot-water types. Clean soot and dirt from the radiator once a month through the “‘clean-out’”’ door at the top. The inset shows water trough, which should be kept full of water to maintain a healthful humid‘ty minutes to get it started in the fall, and it should give good service throughout the winter,

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istible rn at rticles urface he fire te the blow ‘inges, t coal owing 5 work. e tak. e, you ty in 1 ir ac pipes st be steam / Scan r this OTS are es. If orking > very house, plenty er. A yn the system erable fe or SYS- urface ll the ' Cross . great antity ly rea- quate, values ter the | burn, ome if small m the 1 from and all ors on uld be 1 the ughly ie case hot- water in the leaned of the id of a nanner ill only » a few POPULAR SCIENCE MONTHLY 57 Mechanical Aids for the Kitchen Spring jaws attached to a small device for the wall or door serve as a convenient towel holder, providing quick release for a towel when needed. Pulling downward spreads the jaws and re- leases the towel for use The chance that the milk can, with its dust - covered clots of milk around the pouring holes, may become _ un- sanitary is elimi- nated by this simple can puncturer that slips into the holes it has punched | 4 THE completeness of its labor - saving mechanical equipment, the modern Ameri- can home is keeping pace with our most efficient factories. On this page are pictured some of the latest devices to free the house- wife of burdensome drudgery. Jelly making has been simplified by this simple metal frame with adjustable supports that hold the strainer bag securely in place Thiselectrical “mechanical servant” mixes, beats, whips, mashes, chops, slices, strains, and in addition serves as an ice-cream freezer. The insert at the left shows the attachment for beating eggs or batters and making mayonnaise. At the right is the meat-grinding attachment. Above the ma- chine is being used as an ice-cream freezer An entire kitchenette in a small cab- inet.- It contains an electric stove, a sink with hot and cold water, icebox, garbage pail, cooking utensils, kitchen cutlery, glass containers, shelves, com- partments, bread boxes, and drawers Inserting this alumi- num cylinder, perfo- rated at the bottom, and pressing a finger over a tube at the top, quickly draws off the cream from the top of a milk bottle The usual difficulty of cleaning thermos bottles or jars is said to have been remedied in _ this new type hot or cold container. The glass jar is quickly removable for cleaning after use This novel pie-crust trimmer cuts off the overhanging crust and tightly seals the upper and lower crusts by a pronged wheel sineiiahaguemainartamenioatn Sn at SR deere +*heatinsen tate tet ee TANTO cierertnheaentanmmmanirodgatnal aie

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ota aerre> r cher Sata e 9 bow MP FE RS ARI SN me pore gen—ypenconee Tm : 5 re eee MAGNET AIDS PIANO BROADCASTING rege solos always have been one of the least effective features of broad- cast programs because, although the abrupt sounds from the hammer blows are transmitted distinctly, the relatively weak singing quality and the overtones reproduce satisfactorily. fail to The Pencil Radio Set Uses Crystal Detector HE ingenuity with which midget radio receiving sets are made parts of other articles in common use appears limitless. One of the latest of these novelties is this pencil receiving set com- bined with a pair of head phones. Itisa complete radio crystal set and can be carried easily in a pocket or purse. A small tuning coil is wound around the pencil, and the crystal fits into the cup where usually the eraser is. A piece of wire acts as a catwhisker. The set ob- viously is not selective, but it is said to work over a range of from 10 to 20 miles quite satisfactorily. The set is said to be especially useful for taking notes on broadcast lectures, speeches, or sermons. POPULAR SCIENCE MONTHLY % ay ore] General Electric Company now claims to have overcome this defect by a new mag- netic system. The magnet is fastened firmly to the frame of the piano and a coil is anchored to the sounding board. This combination is said to reproduce faith- fully the finer tone vibrations. Solid Auto Wheel Used as Radio Aerial A SOLID automobile wheel proved to be an effective aerial when Miss Genevieve Keane, New York radio en- thusiast, tried the experiment with her one-tube reflex set. It developed that the wheel gave best results when turned in the direction of the broadcasting station— just like a loop aerial. The steering wheel thus became a sort of tuning dial. Wire wound around the spokes of the usual type wheel also is said to have given successful results. ais eee Miss Genevieve Keane, of New York City, using a solid auto wheel as an aerial Amateur Radio Stations Increase Steadily HILE the popularity of radio broad- casting, after a spectacular devel- opment since the winter of 1921, appar- ently reached its pinnacle last _year, amateur radio transmission is continuing the steady advance that has marked its development since its official recognition by the United States government in 1912. Such is the conclusion drawn from figures recently compiled by W. D. Ter- rell, chief government supervisor of radio at Washington, D. C. These figures reveal that in the last 10 years the number of amateur sending stations has increased from 1224 to 16,570. They also show that the number of broadcasting stations has fallen off during the last year. In September, 1923, there were 563 broadcast stations as com- pared with 591 in the month of May, re- garded as the saturation point. Mean- while, the number of amateur sending stations has been advancing steadily and now is at its highest peak. Although amateur radio transmission dates away back to the late ’90’s and almost has been lost sight of in the. wave of interest in the reception of broadcast entertainment, amateur enthusiasm never has waned. This undiminishing enthusiasm is due in large measure to the tremendous ex- pansion of popular radio. Window Shade Serves as Indoor Loop Aerial WINDOW shade that also serves as an indoor loop aerial has been de- vised by W. H. Bullock, a New York radio engineer. The material used is the same as that in ordinary window shades. The wires of the aerial are sewed in around the edges, as indicated by the right hand finger of the man shown above. The aerial is connected with the set at the connections shown on the bottom of the shade. The invention can be hung on any window, the wires being incon- spicuous. Tuning is accomplished by pulling the shade up or down. AFTER wiring a radio set, go over it care- fully. Wherever the wires are close to- gether, reroute them so as to separate them as much as possible. It is better to have the wires a little longer than to have them running close to each other.

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POPULAR SCIENCE MONTHLY

59 A King of Radio Sets Secrets of the Super-Heterodyne—the W orld’s Most Sensitive Receiver TWO CONTROLS SUPER-HETERODYNE yy

By Jack Binns America’s Foremost Writer on Radio S THERE any radio receiver that will ] reproduce programs broadcast from coast to coast? The answer is—Yes! It is the super-heterodyne receiver—the Rolls-Royce of radio—invented by Major E. H. Armstrong, of regenerative fame, to meet an imperative condition during the war. I can say without qualification that it is the most sensitive and the most selective radio receiving apparatus known to man. Simplifying the Super-Heterodyne The chief difficulties in the past that have prevented the popular adoption of the super-heterodyne in the reception of broadcast programs have been the large number of tubes necessary to operate it, and the fact that it required an expert to manipulate its variable parts. The ad- vent of a really “hard” vacuum tube with low filament consumption now has solved the former problem, while the splendid work done by members of the Radio Club of America under the supervision of Major Armstrong has simplified the latter. When the super-heterodyne circuit was

invented, no efficient radio frequency amplifying transformer had been pro- duced. Experience up to that time showed that while it was possible to am- plify radio currents at the frequencies involved in fairly long wave lengths, the question of capacity was too difficult to solve when it came to the terrific fre- quencies that prevail on the short waves. The amplification of radio waves had been accomplished by resistance coupled stages, which, while not very efficient, answered the purpose if the waves were long ones. The problem that confronted Major Armstrong was to design an instrument that would detect the extremely short waves used in trench wireless, upon ex- tremel; low power. These waves, of course, involved frequencies far too high to amplify by means of resistance coup- ling. Armstrong knew that it would be a simple matter to amplify the short waves if the frequencies could be reduced to cor- respond with those of the long waves. He came to the conclusion that if he were to _set up a series of local waves with an oscil- lator, he could produce any frequency he desired by varying the constants of the inductances and capacities of the oscilla- tor. He decided, for example, that if he The newest type of eight- tube super-heterodyne re- ceiver perfected by the Radio Club of America, and George E. Burghard, presi- AUDIOFREQUENCY dent of the club. Note that fe Grd the set has only two con- trols — for wave lengths and for frequency changes were to impress on the detector tube a wave from the oscillator, having a fre- quency difference of 50,000 cycles from the incoming wave, he would get a fre- quency output of the same value from the detector. A Double Detector Receiver Now 50,000 cycles frequency represents a wave length of 6000 meters, and is readily amplified by the regular cascade system. Three stages of such amplifica- tion, he reasoned, would bring the signal up to a point where it could be rectified to work the telephones.” This conclusion was borne out absolutely in practice. The principle of superimposing another frequency on the first detector is known as “‘heterodyning.”’ Because the incoming waves are detected and heterodyned before they are passed through the amplifiers for rectification, the super-heterodyne system also is known as the “double detector re- ceiver.” Since the original model of super- heterodyne was produced, radio frequency transformers have been developed. Now a transformer designed to operate most efficiently at a frequency of 50,000 cycles a second will allow only that frequency to

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OTe | f ¢ ; It. ae ) a Teo ea Gs 66 pass through it, provided it is operating correctly. It is this very fact that makes the super- heterodyne so selective. Whatever may be the wave length of the station we desire to listen to, there is only one point where this wave length will give a beat note of 50,000 cycles when it is passed through the first detector and sub- jected to the clashing fre- quency of the oscillator. This is because there is only one point in the setting of the oscillator where the difference of 50,000 cycles appears. Two Controls Suffice The beat note of 50,000 cycles, which is the product of the first detector tube, faithfully carries with it the modulation of the incoming wave, so that a perfect repro- duction of speech, music, or dots and dashes is repro- duced by the second detector. The latest type of super- heterodyne receiver embody- ing the simplifications made by the Radio Club of America and used as the official receiving apparatus for the recent radio show in New York City, has but two controls—one to adjust the set to the incoming wave length, and the other to change the frequency of the oscillator. Since hard tubes are used throughout, it is necessary to use only one rheostat to control all of them. The new model employs eight tubes without any audio frequency amplifica- tion. It is novel in that two stages of transformer-coupled radio frequency Ds POPULAR SCIENCE MONTHLY varied with respect to the primary wind- ing. Once set, however, the position of the pick-up coil may be left alone, and the frequency change made entirely with the variable condenser across the grid coil, as shown in the diagram on page 59. After we reach the first detector, it is absolutely necessary that every stage mary and secondary binding posts. The size of these condensers will be deter- mined, of course, by the transformers. Since the winding of transformers is somewhat difficult, the builder of a super- heterodyne can employ a standard type of long-wave radio-frequency transformer. This is resonant around 50,000 cycles, and answers the purpose excel- This 14-tube super-heterodyne receiver, designed and operated by Claude Golden in New York City, hears European and Pacific Coast stations with ease, using the loop aerial shown at the upper left should be carefully shielded. The top, bottom, and side of each separate stage should be inclosed in a copper box. Since the detector tube and its inter- mediate frequency transformer may be inclosed together in one section of the shield, a short direct lead may be made from the plate terminal of the tube socket to the primary of the transformer. All the filament and B battery leads may be amplification are used to strengthen the currents picked up by the loop aerial before they are passed through the first detector. This results in an ultra-sensitive receiver, one which is readily capable of receiving Pacific Coast broadcasting stations at the Atlantic seaboard. The secret of the wonderful selec- tivity of the improved super-hetero- dyne lies in the special transformers designed to amplify at 50,000 cycles. Applying Variation Frequency The first part of the Radio Club re- ceiver consists of two stages of trans- former-coupled radio-frequency am- plifiers. Their range is between 200 and 600 meters, with a peak around the Lroadcasting wave lengths. The output from these two stages is impressed on the first detector tube through a grid leak and condenser. In this input circuit, however, there is a “pick-up coil,”*which is coupled with the oscillator coils. In this manner the variation frequency is applied to the first detector tube. Satisfactory coupling can be made through the use of duolateral or honey- comb coils. The grid coil may be a 35- turn, and the plate a 25-turn coil. The pick-up or frequency change coil may con- sist of 30 turns of No. 36 double silk- covered wire on a one-inch tube, and should be placed so that it can be varied in relationship to the honeycomb coils, just as the rotor of a 180-degree coupler is _ What’s Your Trouble? DES your radio set continue to make peculiar noises, in spite of all you can do? Do you fail to get the results, in clearness of reception, that you think your set should give? Don’t miss Jack Binns’ article in next month’s issue. This famous authority on radio will explain effec- tive remedies for the most common radio troubles. And for the radio fan who is building his own set, he will suggest valuable precautions against future difficulties. taken from the rear of the shielding box. This leaves but one connection to go to the succeeding stage—the grid lead from the transformer secondary to the grid of the succeeding tube. This lead should be passed directly through the wall of the shield, through a small hole, slightly larger than the diameter of the connecting wire with its insulation. Naturally the lead should be kept as short as physical conditions will permit. The first transformer connected with the plate circuit of the first detector tube should be tuned as sharply as possible to 50,000 cycles. This can be done by join- ing fixed condensers across both the pri- lently. Connections of the three stages that amplify the out- put of the first detector are similar to those for the stan- dard short-wave _ radio-fre- quency amplifiers, except for the shielding feature. Special Transformer Used When we come to the out- put of the final stage of this intermediate portion of the receiver, a special transformer must be employed ahead of the second detector. In this connection George Eltz, Jr., a member of the Radio Club of America, who has done much work on the super-hetero- dyne, recommends the fol- lowing, where intermediate transformers are used: The primary of the special transformer should be wound on a bobbin three inches wide, with a center one inch thick, and a space of one quarter of an inch between the sides. The wire is wound just as ona cotton bobbin, except that the winding space will be only a quarter of an inch wide. The primary should have 200 turns of No. 29 double silk-covered wire. Directly over this is wound the secon- dary, which should consist of 1500 turns of No. 36 double silk-covered wire. In winding these coils, no particular care is necessary; in fact, they can be put on just like cotton on a bobbin. How Resonance Is Gained In the circuit the primary is shunted by a fixed mica condenser of .0075- mfd. capacity, to make the trans- former resonant to the best frequency of the long-wave radio-frequency trans- formers. The secondary of the trans- former is placed across the grid and filament of the second detector tube. If an audio frequency amplifier is added to the receiver, a fixed condenser of .005-mfd. capacity should be used across the plate and filament terminals of the detector tube. This will prevent any of the intermediate frequency cur- rent from entering the audio amplifiers. For those who do not know just how to get the correct value of the fixed condensers named above, I may add that the trick can be done by adding fixed condensers of .0025-mfd. capacity in parallel with each other. Three such con- densers will have a total capacity of .0075 mfd., and two of them in parallel will give .005 mfd. When properly constructed, the set is very simple to operate, since only two controls are required. Construction of a set of this type, however, should not be attempted by any radio fan who has not first experimented with the simpler types of radio receiving apparatus. Q44@-. MW

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The ter- s is per- ype ner, and cel- hree out- are tan- -fre- > for Jsed out- this the rmer d of this [r., 2 ib of auch tero- fol- mers rmer ches nda veen ona ding inch urns wire. con- urns care put nted 075- ans- 2ncy ans- ans- and be. or is nser used nals vent cur- iers. how ixed add ixed r in con- 0075 give et is two t be not ‘Portable Steam Radiator Heated by Gasoline A PORTABLE radiator that supplies steam heat without coal has been perfected for use in isolated rooms, rooms that are difficult to heat adequately, and for small apartments. Two burners, fed from a tank of gaso- line below them, heat the air in a special chamber. The hot air in turn boils the water in the tubular chambers. The resulting steam circu- lates through a system of copper __ tubes that radiate the heat. The device is said to be odor- less. It holds fuel and water enough to last a week, it is claimed by the manufacturer. The portable radiator Famous Dance Floor Is Supported by Springs NCE in a decade workmen with wrenches ‘“‘tune up” the famous dance floor of the grand ballroom at the Hotel Savoy, in London. This remark- able floor rests upon steel girders sup- ported by powerful coil springs that im- part resiliency to the dancing surface. The ' ity on the shoe side © U.&U. The end of one of the steel dance-floor girders with coil spring attached floor is designed to bear a weight of 250 tons. The “tuning up” process includes over- hauling the springs and girders, as well as refitting and polishing the boards of the dance floor. — Lightning as a Weapon “TN SOME future war our scientists may be able to hurl a devastating bolt of lightning across the ocean.” Such was the recent statement of Robert Sibley, former vice president of the American Institute of Electrical En- gineers, discussing an announcement by Professor Harris J. Ryan of Stanford University that ‘“‘control to some extent” of man-made lightning is possible. POPULAR SCIENCE MONTHLY WHERE HUNTERS HROUGH centuries of rugged en- vironment the hardy natives of St. Kilda’s, a partly barren island of the Hebrides, Scotland, have learned unusual ways of wresting food from Nature. Their method of snaring wild fowl requires careful stalking and astonishing dexterity. The photograph shows a hunter snaring SPRING HEELS, TO HERE is an old tale about one “‘Spring-heeled Jack,’’ a thief who contrived a pair of heels with which he was able to travel in 15-foot jumps. Perhaps the in- ventor of the spring- heel here illustrated found his inspira- tion in that old tale. The device consists of an ordinary rub- ber heel with a cav- in which is fixed a Snaring a wild petrel on the jagged cliffs of St. Kilda Island. With a long pole the hunter casts a loop of horsehair over the bird’s head, lassoing it as shown 61 “FISH” FOR BIRDS a young petrel—a bird that is regarded as a particular delicacy. A loop of horse- hair at the end of a long, slender pole is flung deftly over the bird’s head, and a quick jerk traps the game. The almost inaccessible ledges on which the birds are found increase the hazards of hunting them. “BOOST” WALKERS strong steel spring. In walking action the wearer is sup- posed to compress this spring at the beginning of the step. As the step is completed the spring is expected to assist him. It is claimed also that the spring action supplements the re- silient rubber heel A TOBACCO pouch designed to roll a cigarette or fill a pipe without spilling a grain, is a recent addition to the con- veniences offered smokers. A pipe is filled through a‘tube attached to the pouch. In making a cigarette, the paper is rolled about the tube and the ex- posed end is closed. Then, with the pouch upside down, the paper is slipped for walking. TOBACCO POUCH “ROLLS YOUR OWN” down near the end of the tube, where it is held firmly. Next, the tube is worked gently in and out of the pouch until the paper case is filled. Finally, the tube is pushed all the way into the pouch. The rubber-surfaced leather substi- tute of which the pouch is made is claimed to keep tobacco;affoist. The pouch holds enough for 30 cigarettes. i sdanmaeasiiarmeniian

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‘ § - alia Das ns 5 62 POPULAR SCIENCE MONTHLY A BAROMETER CLOCK This giant barometer with dial face, on the tower of the German Museum at Munich, Germany, is said to be the only one of its kind in the world. A SS single hand chronicles the a, slightest variations in at- . mospheric pressure, indi- ee cating probable changes in the prevailing weather A SHOTGUN NINE FEET LONG, recently captured by game wardens on the Potomac, Washington, D. C. Mounted on the bow of a motor boat, it is said to have killed as many as 500 ducks at one time. It weighs 150 pounds THE MINUTE HAND OF THE WORLD’S LARGEST CLOCK is so huge th t 17 men were required to carry it to a position where it could be hoisted to its dial on the roof of a building in Jersey City, N. J. The hand is 20 feet, eight inches long THIS LOCOMOTIVE FIRE DEPARTMENT is maintained by the Southern Pacific Railway in California to protect small mountain towns along its line that are endangered by the devastating forest fires. Sufficient water is carried to throw out two powerful streams on a fire for an hour A BOAT LIKE A FROG, shown at the left, as much at home on land as it is in water, motors through the streets of Scarborough, an English seaside resort, picking up passengers. Then it puts to sea for a spin over the waves. The craft is driven by an auto engine geared to the propel- ler when the boat is in the water, and to the wheels when it is on land, which makes it amphibious

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POPULAR SCIENCE MONTHLY © U.& U. THIS REMARKABLE AUTOMATON DISPLAY, reproducing in lifelike form the Last Supper of Christ and His Twelve Disciples, is the product of 40 years of painstaking labor by an obscure Ohio locksmith. It was purchased re- cently by John Scharding of Chicago, Ill. The 13 figures are in life size and are controlled by intricate mechanism that moves their arms and bodies and changes their facial expression. The machinery is said to weigh more than 2!4 tons THE LARGEST VIOL The huge bass viol shown below is 14 feet high, more than two feet taller than its nearest competitor, ac- cording to A. S. Filson of San Diego, Calif. To play it the musician must stand on a stage five feet high ie eon Oe eee MOSAIC SIDEWALKS line the principal boulevard of Rio de Janeiro, the South Ameri- can “City Beautiful.” The walks, about 25 feet wide, are surfaced with little black and white stones about an inch square, laid in varied designs kM ee ee ae DOG ON WHEELS - When an irritable cow kicked Peggy, a pedigreed bulldog of Butte, Mont., crushing her backbone, her owner devised this ingenious wheeled support. Now Peggy ranges her old haunts, followed by her puppies PLUMBER’S MAST More than 11,000 pipe fittings, involving 14,- 089 joints, were used in this accurate miniature model of the famous Eiffel Tower, exhibited by one of America’s leading valve manu- facturers. The model is 1214 feet high and 4% feet across the base. It is fitted with lights and elevators f 63 a a ee es a Sata Nar ar me Aimed — ep oR te —cnrunineninusietaapmsaamaiirn- tetera ERE TOE Se A NAOT AA AORN EY BS anaes arenes ==

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ip ee ena eee aioe Se POPULAR SCIENCE MONTHLY “ ST a Sie ee : SRE Drains and Flood Gates Protect Arizona Town ITUATED in a narrow valley and divided in two by a river, the town of Clifton, Ariz., is in constant danger of being inundated by swollen waters of the river during heavy rains. For protection, corrygated iron storm drains are provided to carry off the sur- face water, these emptying through a concrete and masonry levee. As a further precaution against unusually high waters, the drains are equipped with 48-inch cast-iron gates that close automatically whenever the river rises to their height. Concrete levee at Clifton, Ariz. Arrow points to one of the storm drains, shown at left Double Arbor Press for Automobile Work my NEW arbor press, especially de- signed for motor-car repair work, combines two separate presses for large and small work. The main press is oper- ated by a wheel to which additional pres- sure can be given by a lever and ratchet device. A smaller rack and pinion press at the left of the main screw is said to be of great value in wristpin, bearing, and bushing work. Large and small presses in one machine CLAIMS AIR MOTOR BUCKS THE WIND N AIR motor, which its inventor claims will move a boat or vehicle directly against the wind and will virtu- ally manufacture,its own wind when no air is stirring, has beerf developed by Charles R. Ford, of Elma, Wash. The contrivance consists of a series of fans, or windmills, mounted on_ the Above: Thirty- blade air motor, in- vented by Charles R. Ford. The housing is removed to show arrange- ment of windmill wheels. At right: The invention driv- ing asmall raft by wind power same shaft and in- closed in a cylinder. Between the fans are stationary pieces of metal, which the inventor calls “air straighteners” and which he says so dis- tribute the currents passing through the housing that each fan generates the same amount of power. New Transatlantic Cables from U. S. to London HE first transatlantic cable to be laid since 1910 started recently from Far Rockaway, N. Y., on its long journey. More than 4,000,000,000 pounds of copper were required for its conductor and nearly 2,000,000 pounds of gutta percha for its insulation. More than 80,000 miles of steel and iron wires were wrapped spirally about the cable as a protection. In shallow water, where the danger of injury is greatest, the unusual protection necessary makes it weigh 20 tons a mile. In midocean it weighs only two tons a mile. From Far Rockaway the cable will be Starting the cable at Far Rockaway, N. Y. routed to Canso, Nova Scotia, from there to the Azores, and thence to London via Waterville, Ireland. World’s Largest Grinding Wheel Weighs 20 Tons GRINDING wheel with a 66-inch face, said to be the largest in the world, has just been completed by a ma- chine manufacturing company of Prov- idence, R. I., for such work as grinding boiler sections having a height as great as five feet. The abrasive wheel is constructed in 22 sections. Driving power is supplied by a motor of 75 horsepower, the wheel spindle attaining a speed of 180 revolutions a min- ute. The machine weighs 40,000 pounds.

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1S Striped Boiler Gage to Prevent Explosion MAan* a boiler explosion has resulted from the fact that the fireman be- lieved his boiler gage glass was full when mine th io & wee empty. To pre- vent this haz- ard there has been perfected a striped back- ground for gage glasses that re- veals at a glance whether the boilers are full or empty. The lines as seen through the water in the glass are at right angles to those of the background, and the lines through the empty section of the glass are approximately at the same angle as those on the _ back- ground. The scheme was first developed for use in the Edison Lamp Works at Newark, N. J., where the interior of the fireroom is white. New Camera ‘‘Gun’’ Serves as Important Weapon Me ne & A ‘THE camera gun for photographing both movies and stills has attained a military dignity nearly equal to that of the most powerful war weapons. Both kinds of photographs are used extensively in determining the effect of smoke screens, shell fire, and aerial bombs, and for estimating the velocity of projectiles. Chief photographer J. M. Hayme, of the U. S. S. Wright, is shown above with his odd looking navy model K-1 aerial camera, taking ‘‘movies’”’ from a torpedo plane. This remarkable camera has a special 24-inch lens. T= Editor will be glad to supply, wherever possible, the names and addresses of manufacturers of devices mentioned in this issue of POPULAR SCIENCE MONTHLY, / POPULAR SCIENCE MONTHLY 65 THE WORLD’S LARGEST BRIDGE GIRDER © U. & U. cently as part of a railroad bridge at Rock Island on the Mississippi. This giant girder weighs 97 tons and is 114 feet long. Two powerful cranes lifted it. EUROPE BUILDING MOLDED HOUSES BESET by a shortage of materia! and labor, Europe today is experimenting walls. with an inexpensive method of building houses by molding them of a cheap mixture of gravel, sand, and slag with a small proportion of cement. This mixture is said to equal masonry in durability, heat in- sulation, freedom from cracks, ad- herence of plaster, and nailing quali- ties. It is cast in molds made of sec tions that are fitted together in a few hours. The MOTOR SPEEDWAY ON FACTORY ROOF IGH above surrounding roofs of The track is used for testing the cars Turin, Italy, has been constructed of a well-known Italian automobile manu- the most remarkable motor speedway facturing company. Each chassis, when in the world—a three-quarter-mile track, assembled, is taken to the roof by elevator 70 feet wide, with steep banked turns and driven around the track at top speed around which high-powered cars, stripped until the staff engineer conducting the to their skeletons, dash every day at the _ test is satisfied with its performance. greatest speed their roaring engines can The track is of armored concrete with a produce. top dressing of asphalt. It consists of two long stretches and banked turns. Con- crete walls five and ten feet high act ie S= as safeguards. HILE - motion-picture cameras clicked and hundreds of spectators cheered, the longest and heaviest steel bridge girder in the world was laid re- The three-quarter- mile speedway on the roof of an auto- mobile factory at Turin, Italy, and, above, one of the high banked turns re En een ae windows and doors are cast with the It is claimed that these molds can be used at least 30 times. : : 2 _ er 7 . i ae aeaceaeeieien eli’ —————

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~ PAL TRE D 2 aig * 4 5 ay) - 5 EI A BEES By Ag he PR, S PE. » PR wo Serene rape ater ¥ ae | ae ‘ She Jig eR Ae © RT ARET agi POPULAR SCIENCE MONTHLY Motor Yacht Controlled by Three Pushbuttons — what contempt would Colum- bus, Sir Francis Drake, or any of those storied mariners of old, view the ingenious automatic navigation of this craft! In it three pushbuttons have reduced propulsion control from a matter of sailcraft to the pressure of a finger. This motor yacht, the Wanda II of Bridgeport, Conn., was launched re- cently. A group of distinguished marine engineers and designers observed her on the trial trip. . They are said to have acclaimed the pushbutton control a re- markable success. The buttons govern an electric motor in the stern. This motor in turn controls a new type of rudder, the latter inclosing the propeller within two concaved leaves. Adjustment of these leaves produces full ahead, stop, or reverse without need of shifting the engine gear. Finds Oysters Change Sex YSTERS change their sex three or four times a year, according to the statement of the Danish scientist Sparck after investigations at the Limfjord ex- perimental station. He believes the changes are caused by variations in the temperature of the water. The motor yacht Wanda II at Bridgeport, Conn. At the left, the pushbutton controls Slide Control Simplifies Saxophone Playing A NEW instrument designed to make it easy for any person to master saxophone playing has just been perfected by a Chicago concern. The outstanding feature is a slide in place of the usual finger stops. Instead of the usual holes covered by padded keys, the tones of the chromatic scale are produced by means of a slotted tube of unique design, which is soldered longitudinally to the body. Inside the slide is a closed tube that acts as a valve in opening and closing the slot. The notes are produced by moving the tube up or down. The mouthpiece, reed, and manner of sound production are the same as on the regular soprano saxophone. Moving a sliding tube produces tone variations Tennis in Small Space for Any Season BALL game for winter or summer, that can be played in a space as small as seven by three and a half yards has been invented and popularized in England. The game is. an adaptation of tennis. Any small yard and even a large room can be used. At one end of the court is a BOARD POCKET Backstop' construction, rectangular showing pocket, net, frame holding and board netting that ex- tends three feet from the ground. Above the netting is a board, fixed between the frame’s uprights. In the exact center of the frame, at the juncture of the board and the net, is a small net pocket. The player tries to serve the ball into the pocket. Failing in this, the ball will The game in progress on a back-yard court strike either the net or the board. If it strikes the net, the player loses a point. If it strikes the board, the ball rebounds and returns into court just as would a ball served from the opposite side of the court in tennis. The ball then must be played by the opposing player. The ball is kept in action until one of the players serves it into the pocket, winning the point, or serves it into the net or out of bounds, losing the point. Scoring is similar to that of tennis. New Plant Diseases Found A RECENT survey completed by the United States Department of Agriculture shows that hitherto unknown diseases are attacking common American vegetables. ° The government specialists found that among the plants affected are tomatoes in California; spinach in Idaho, Washing- ton, and Oregon; Chinese cabbages in Texas; radishes in Missouri; watermelons in Washington, D. C., and Washington State, and potatoes in New York, New Jersey, Pennsylvania, and Vermont. Most of the diseases, it has been ascertained, are caused by various sorts of parasitic fungi.

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id the of wn pan hat 3in ng- . in ons ton lew een. orts Airplane Photos Reveal City Fire Traps The latest type of automatic camera for air- plane photography, run by storage battery By G. B. Muldaur Gen. Agent, Underwriters’ Laboratories HE utilization of aerial photography by municipalities in preventing fires was demonstrated recently in experiments and is recommended by the Underwriters’ Laboratories, a non- commercial organization associated with the National Board of Fire Underwriters in the testing of materials and devices designed to eliminate fire hazards. Many airplane pictures of cities were taken by expert camera men from a height permitting the photographing of buildings, streets, and vacant land in de- tail and without distortion. The photo- graphs then were pieced together, form- ing accurate topographical views of the cities. Maps were prepared from tracings of the composite photographs. Maps traced from aerial pictures have been found markedly superior in some respects to the insurance maps commonly used to show the physical condition of cities, neighborhoods, and_ individual structures with relation to fire risk. As one point of superiority, the prep- aration of a city map by surveying is a POPULAR SCIENCE MONTHLY long and tedious process, while an air- plane map can be produced with com- parative speed, and, by means of an aerial] patrol, can be supplemented constantly. Also, the usual insurance maps, which designate various fire hazards by colors and symbols, take into account only structures, giving no definite informa- tion of those that may lie in vacant places The application of aerial photography to fire prevention was indorsed by Major R. W. Schroeder, former holder of the world’s altitude record and now in charge of the aircraft division of the Underwriters’ Laboratories. CLOSED CAR BUILT LIKE SUBMARINE “Submarine sedanette’’ designed to protect its occupants from dust ERE is the latest thing in motor-car novelties — the “‘subma- rine sedanette.” It is called a “submarine,” not because it can be operated in water as well as on land, but because of its body construction, which resembles the con- ning tower and half the hull of a submersible. The unusual body de- sign aims to protect the driver and passengers from the white dust that is common on the high- ways of Europe, where the machine was con- structed. 67 " * a aera al ‘ De? ped Above is an aerial photograph of a city section, from which the fire map at the left was traced. The photograph reveals fire hazards such as piles of rubbish in vacant lots and automobiles parked so as to obstruct the streets Officers Give Commands by Loudspeaker i 250 lusty-lunged drill sergeants of the Regular Army should get together and join in roaring ‘‘Fall in!’”’ the resulting effect, it is said, hardly would equal the a’. ~ The officer issues orders in an ordinary voice noise of a single voice magnified by a huge portable amplifier recently put into opera- tion by the United States Signal Corps. The outfit consists of four amplifier horns mounted on a towering tripod. It can be collapsed and transported from place to place in a motor truck from which it is operated. The officer stands beneath the tripod and issues his orders into a microphone. With this equipment, it is claimed, a single officer can drill large bodies of troops. : Cera eee eee eee eee aca acne cane es conmeumsnmmamanie cam acetate imams amas ele mmm omen casei intanios oe neat Pe ———E Sa A RE Se ZS

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ve ACME RDNA OREN aT SY pcan eA RRND IY, Ge WS ae SBT aoa A +e 6 a ify " seed oa a ~ +36 . >= é . * +} y | O DETERMINE the resistance to wear of leather and other materials used in shoes, the United States Bureau of Chemistry in Washington, D. C., has undertaken a series of tests to eliminate undesirable products and to standardize materials. In service tests on 14 pairs of soles, one sole of each pair was of plain leather, while the other sole was treated by a special process to increase the wear re- sistance. This process consists of covering the entire surface of the soles with stitches looped and locked near the center of the sole. The wood fiber thread used was thoroughly saturated with wax. POPULAR SCIENCE MONTHLY SHOE LEATHER TESTED BY UNCLE SAM The results of the tests show that leather so treated wears about 25 per cent longer to the unit of thickness than un- treated leather. The increase in wear appears to be proportional to the amount of fiber material added to the leather. In addition, several commercial prod- ucts used in the making of shoes have been tested on a special machine, shown above, that in a few hours subjects the material to the same wear that it ordinar- ily would be expected to withstand in months of actual service. The effect of wear on wet shoes, and the value of polishes and waterproofing materials, also are being studied. Portable Heater Supplies Running Hot Water OT water in a few seconds and con- tinuously thereafter is supplied by a small portable heater recently invented in England. Denatured alcohol is burned in the device, the heat being conveyed ‘to an ingenious arrangement of coils through which the water circulates. This heater can be used also for light cooking. Handy Case for Neckties Irons out Wrinkles HAT man, dressing at a sprint 20 minutes behind his social schedule, has not let loose an outburst of temper at finding his favorite necktie hopelessly wrinkled? This little pressing case is designed to remove wrinkles and to keep ties always neatly pressed. Within the case is a series of stiff fiber plates between which the ties are placed. Pressure is applied to the plates by means of thumbscrews. The ends of the case are hinged so that any tie can be removed without disturbing the whole set of pressing compartments. Small compartments in the cover of the ease are designed to hold collar buttons and stickpins. The entire outfit takes up little room. ‘A Mouse Trap that Won’t Catch Fingers ANY a mouse trap catches more fingers than it does mice. Yet the simple twist of wire shown at the right be- tween the fin- gers of the oper- ator is said to protect the hands without interfering with the trap. A twisted wire aids in setting the trap Pencil in Fountain Pen A COMBINED fountain pen and mechanical pencil, the size of an ordinary fountain pen, is one of the latest pocket writing conveniences. The pen portion is self-filling. Pencil points can be replaced. The combined fountain pen and pencil Forked Spear Hooks Fishes F ved hesied the principle of the fish- hook to a spearing fork, Solomon T. Henry, of Downsville, La., has created a deadly weapon for fishermen. Both tines of the fork are flattened and each has a recess a few inches from the point. A prong with an upstanding flange extends toward the handle from each recess, swingable outward 40 degrees. The inventor and his novel fishing fork _,

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How to Weigh a Letter with Ruler and Coin O YOU ever put extra postage on a bulky letter to save a trip to the post office? This simple but effective scales will give you the correct weight of a letter. Place a 25-cent piece on the 12-inch end of an ordinary foot ruler. Rest the ruler upon the sharp edge of a pocket knife at the six-inch mark. Now hold the letter to be weighed loosely between the thumb and fin- ger, and bal- ance it on the ruler at the 4 34- inch mark. One coin will coun- terbalance one ounce, the limit for two-cent postage. Two coins will coun- terbalance two ounces, and so on. Lest you forget, you might make a circle at the end of your ruler and mark the two graduations to be used.

Ingenious Safety Guards for Carving Fork

Above: A simple bent wire guard. At left: Aux‘liary spring for broken guard

EARLY every carving fork is equipped with a hinged guard; yet often, after years of use, the spring breaks or the guard is broken. Since it never is safe to use carving utensils without a guard, the two types of auxiliary guards shown above have been invented. The e Upper illustration shows a wire guard that can be sprung on to almost any carving fork. The lower illustration shows a spring that can be slipped on beneath the ordinary guard should the original spring break. Either device will prolong the life of a carving set.

A™MA4Z!I NG photographs showing the nature and movements of atoms will be published in next month’s issue through the courtesy of Sir Ernest Rutherford, the great British physicist.

POPULAR SCIENCE MONTHLY 69

Be ese this 21 by 60 foot barge from White Horse to Lake Labarge, in the Yukon Territory, Canada, seemed offhand an impossible task. No water route was available, and the width of the barge seemed to make rail trans- portation impossible. But so sorely was the barge needed for work on a large dam being built in a BARGE GOES 43 MILES ON FLAT CARS

stream that empties into the lake, officials of the White Pass & Yukon Railroad agreed to try. They waited for the first windless night and then, bracing the barge in a perpendicular position on a flat car, as shown above, they made their cautious way over the 43 miles to the lake. A rising wind might have wrecked the train.

Small Electric Hand Saw for the Woodworker N ELECTRIC hand saw, compact, light, and usable with all sorts of saw teeth by interchanging blades, has been designed especially for woodworkers. The tool is moved across the work much like a hand plane. It is eccentrically mounted in its frame and capable of ad- justment relative to the frame. It will cut a groove thirteen sixteenths of an inch wide and one inch deep, or it will take a two-inch cut. It can be used for cutting flooring, making grooves for inlays, fitting doors, cutting through slab doors, and many other operations.

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This Bill Fold Contains Handy Score Card COMBINATION billfold and score card is a recent invention for sport lovers who like to keep their own box scores, or to keep a running record of golf, basketball, track, and other contests. In addition to the usual bill compart- ments, there are two record card pockets with dulled celluloid faces through which the printing on the card is visible. Pencil writing on this celluloid is distinct, yet it can be erased with a damp cloth or a hand- kerchief. When not in use as a score card, the celluloid surfaces can be used for memoranda. On the record cards are printed the names of various teams and the players, as well as the record of each player made the previous season. <-nmanemtnent ategpeehe aT TO LTT TT TN TR LTT CL TEL LET OLE EL a

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aig a haha ate aad eae ae te ses eee Mariah are POPULAR SCIENCE MONTHLY HUGE reinforced concrete ball, hollow, more than seven feet in diameter and painted inside and out with a highly reflecting white paint, is kept at the Bureau of Standards, in Washing- ton, D. C., to measure the candlepower of electric lamps and their brightness. The lamp to be tested is placed, through an opening in the top, within the sphere, where the white walls centralize the intensity of the light upon a measur- ing device. A special arrangement of milk- DISCOVERS STAR DENSER THAN ROCKS ITH the giant j “ER telescope shown at the right, Dr. Frank C. Jordan, of the Alle- gheny Observatory, Pittsburgh, Pa., claims to have discovered the densest star known to astronomy. It is called a variable star, for it consists really of two bodies revolving about each other. The two bodies are egg-shaped, with their long axes directed toward each _ other. They eclipse each other twice in a complete revolution, or at inter- vals of 170 minutes. These bodies are be- lieved to be denser than the surface rocks of the earth. The star is so faint that at its brightest the light would have to be strengthened 130 times to make it barely vis- ible to the naked eye. At its faintest, it would have to be strengthened 270 times. Neither its distance nor its actual amount of light is glass windows and tubes permits the ob- server to study the light while it is in the sphere. This curious sphere was used in testing the ‘‘jewels’”’ for the famous Tower of Jewels at the Panama-Pacific Exposition. TO DETERMINE whether a fabric is all wool, or part wool, boil a bit ina concen- trated solution of caustic soda or caustic potash. The wool portion will disappear gradually. Ps. i oa known. Doctor Jordan and telescope used in discovering new star New Disk Machine Blends Colors Scientifically MACHINE designed to blend colors scientifically has been invented by Prof. Edwin B. Twitmeyer, of the De- partment of Psychology, University of Pennsylvania. The problem is one that has defied the ingenuity of scientists for many years. Advertising experts, textile makers, eye specialists, and interior decorators are among those who will benefit from the studies into the principles of their arts that the device is said to make possible. The basis of the machine is two colored disks, fitted together so that parts of each show as the disks revolve rapidly on a shaft. Such devices, in crude form, long have been used to demonstrate the strik- ing effects of colored lights when com- bined. © These effects are quite different from those of colored pigments. For ex- ample, as every school child knows, green is obtained by combining blue and yellow. Yet blue and yellow disks, when spinning together, give a grayish white. The ingenious feature of Professor Twitmeyer’s machine is that the position CONTROL LevER J ADJUSTS DISKS COLORED i DISKS The blending machine, showing color disks and lever controlling the amounts of color exposed of the disks may be changed while the shaft is in motion, varying the visible amount of each color. The exact ratio of the two colors is shown by a graduated scale at the top. Spotlights may] be trained on the disks and used to add still more colors to the combinations. Colored Silks Are Used to Imitate Marble 6 pee ingenuity of scientists in creating substitute, or imitation building materials is strikingly demonstrated by the recent invention of a “‘marble’’ that can be manufactured on the job. By this process, derived from Italy, a net of colored skeins of silk is laid on a piece of oilcloth. Over the silk and cloth is spread a layer of special cement. After the cement has stood for a few minutes, the silk is withdrawn. The slab then is levelled carefully and covered with astrip of cheesecloth and a layer of dry plaster. When the cloth and plaster are re- moved, there appears a slab of putty-like cement in which is a colored pattern left by the silk. This pattern is said to duplicate almost exactly that of natural marble. SN RR

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POPULAR SCIENCE MONTHLY Geologists Brave Floods to Map the Colorado ee death almost constantly while their boats were swept along by flood rapids in the Marble and Grand canyons in northern Arizona, 11 members of the United States Geological Survey reeently completed what has been called the most dangerous enterprise ever undertaken by government agents during peacetime—the mapping of the treacher- ous waters of the Colorado River and ex- ploration of the canyon gorges. Three months were required by the ex- pedition to traverse 300 miles, a day’s journey for a fast automobile. Four boats, specially constructed and fitted with air chambers, carried the mem- bers of the party, who were strapped into the cockpits and wore life preservers dur- ing the entire time they were afloat. A radio receiving set furnished their only means of communication with the world. At one time, during heavy floods in the Colorado, the outside world believed the entire party had perished in the deluge. When the explorers at last reached civil- ization, stripped to the waist and tanned as dark as Indiams, they told a dramatic story of their narrow escape from death. . ELL ODES, CURVE DLE LOE LG LOE (ip saa” | se Seger SAARC STR CARRE SCRE GRE ATES NES bh pot : \ ) \ \ nt « How the explorers, strapped in boats fitted with air chambers, rode the Colorado rapids One night the river rose 20 feet and_ in progress since 1909. As a result of the multiplied its volume 10 times. They recent expedition, complete records are* ‘spent the night struggling to protect the now available of more than 1200 miles of Z boats. One boat was hauled up the face the Colorado and Green rivers and their ia : § of the canyon wall by block and tackle, principal tributaries. The expedition was MADELEINE While others were moved to points where’ in charge of Col. C. H. Birdseye, chief A bird’s-eye map of the treacherous Colorado River they could bedragged up ahead of the flood. topographic engineer of the Geological canyons explored by the government geologists The mapping of the Colorado has been Survey. 1. Why do we grow old? HAT science touches the every-day lives of our readers at . 7. What is a rainbow? : : thousand points is evidenced by every mail. Scores o ‘s 2. What is the difference uestions, as varied as science itself, come daily toour Information 8. Is perpetual motion b land } ; a a coat an Editor. From these have been selected the dozen typical queries possible? ra coa printed here. To test your knowledge, see how many of these 3. What is the fastest you can answer correctly. 9. Why do vacuum bot- thing in the universe? It’s a fascinating game in which you can’t lose. Even though tles keep things hot 4. Whe te Lendl ~~ you fail to make a high score, ay will gain useful scientific or cold? . y 1s ndon time _ knowledge. So whet your wits and try them out. When you different from New have finished, turn to page 135, and check up your answers. 10. Can diamonds be York time? There will be another dozen next month. made artificially? 5. Why must ice cream be stirred while freezing? 11. Why does wool shrink when it is wet? 6. Why is it that a hurt received while you are 12. Why does the hair grow thickest on top of excited is seldom felt until afterward? your head and very little over the body? }

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hig Ore se res REE PLO Pew 72 POPULAR SCIENCE MONTHLY A Treasure that Fell from the Sky Scientists Believe a Fortune in Minerals Ts in Meteorite Burted in Arizona Desert Craters on the moon, from an astronomical photograph. Some scientists believe they were formed by the impact of enormous meteorites—a _ theory based on their re- semblance to earth’s meteorite craters, such as the grect Arizona crater shown at the right. Some of the craters on the moon are 60 miles in diameter DIAMETER Ye MILE DRILLING RIG 1 ‘ he ~ 7 THE CRATER TODAY 8 pe N THE Arizona Des- Se _ ig ert, midway between eg Sees GB the Grand Canyon Sie ee i and the Petrified Forest, i 9 Brown Hawk Wing, a wise man of the Navajos, tells a story that is gen- erations old. Like many legends of once savage folk, it parallels with uncanny accuracy the scientific explanation of a weird phenomenon of nature. Ages and ages ago, the Indians say, three of their gods, seeking eternal rest, rode to the earth on flaming blue thunder- bolts that cleaved for them a deep and wide-mouthed grave. Therein those gods still lie, runs the legend, in their endless sleep, covered with recks and iron and a pure white dust that is fine as flour. And terrible is the fate that will clutch the desecrators of their slumber! That is the Navajo version of the fall of what science calls the Canyon Diabolo meteorite, a huge lump of celestial matter that is believed to lie embedded in the solid rock, 1400 feet below the desert sands, beneath the 570-foot crater that it blasted out when it plunged flaming from the sky. For 40 years the Navajos have been shaking their heads and prophesying evil as they have seen the white man’s machin- ery set up at the crater’s edge and his drills bite into the tomb where sleep their gods. For mining engineers believe that the buried meteorite is a giant treasure chest of iron, nickel. platinum, iridium, and other valuable minerals. The size of the celestial visitor has been variously esti- mated as between 300 and 1000 feet in diameter and its weight as between a few \thousand tons and many million. Twenty years’ digging has failed to locate the treasure. The Navajos wag their heads sagely, saying that their gods know how to protect themselves, even in death. Recently, though, the seekers were given a favorable sign. The steel point of an oil drill, boring into the rock, was shattered against a substance harder than itself. Wasit the meteorite? The engi- neers are assuming that it was and have sent for additional mining machinery to sink a shaft. What the drill struck is more than 1400 feet below the surface. The sinking of the proposed shaft will enable the engineers definitely to ascer- tain if the mysterious substance was a part of the long-sought treasure. But its sinking is likely to prove a difficult task. At one time the pit was thought to be of A typical Canyon Diabolo meteorite fragment, weighing 357 pounds. Many thousands of smaller specimens, like those at the base of the stand, have been found about the huge crater Deep beneath this yawning pit in the Arizona desert scientists hope to find the Canyon Diabolo meteorite, which is believed to have plowed through earth and rock diagonally, burying itself in the position shown at left Brown Hawk Wing, wise man of the Nava- jos, who recites the Indian legend con- nected with the crater. He relates that three Indian gods, seeking eternal rest, rode to earth on flaming thun- derbolt? that cleaved for them ae wide- mouthed canyon grave voleanie origin, and the meteoritic fragments that lay about it and lent color to the meteor theory merely a _ coin- cidence. Modern science, however, has caused this theory to seem quite untenable, since in no part of the surrounding region—or in the great pit itself—is there any mark of voleanie action. So for some years it has been regarded as the handiwork of a monster meteorite. However, it is believed that the vast ob- ject is not embedded in the center of the pit, but to one side of it, this latter cir- cumstance being due to the fact that the lump of matter fell obliquely through space and continued its slanting path after it had struck the earth. The crater has a form that resembles on a giant scale a lump of mud or soft plaster into which a ball has been thrown. Much of the interior of the bowl is composed of white “rock flour,”’ believed to be pulver- ized sandstone that was ground beneath the meteorite in its fall. Layers of gray sandstone, and, below the ‘‘rock flour,” red sandstone that was not disturbed by the falling body, compose the rest of the crater. Specimens of the meteoritic fragments are of such interest, that tons of them have been removed and placed-in museums. Natural conditions, climate, and the presence in the neighborhood of thousands of rattlesnakes and rats, impede the prog- ress of the mining operations. But they are being carried on whenever possible and their results will be awaited with eagerness both by the scientific world, which is seeking corroboration of its theory, and by the general public, which cannot but be thrilled by so dramatic a project as that of digging out a treasure chest fallen, centuries ago, from the sky. a —m = =e KH HA etm Ha OSs OO

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POPULAR SCIENCE MONTHLY Automobiles of 1924 Show Marked Mechanical Improvements 110,000,000 persons in the United States either owns an automobile or rides in one belonging to some one else. The 13,000,000 Americans who own ears today, almost without exception, are planning for the time when they will get new machines. And those who do not own them are looking forward to the time when they will. Consequently, the ap- parent tendencies in automobile construc- tion, as indicated by the 1924 models of various makes, are a matter of almost universal interest. These tendencies represent an increased value that the mechanical and manufacturing P2i10,000.000've every one of the By H. Clifford Brokaw of Society of Automotive Engineers removable. When these are taken out, the car can be converted into a cozy bun- galow with 50 cubic feet of space. For touring and camping, this design has many commendable points. For example, it is possible to make up a bed on the floor of the car—a bed in which a person actually can stretch his limbs in comfort- able repose. In addition a novel mechan- ical device makes it possible to adjust both front and rear seats backward and for- ward. This feature insures comfort for owners to carry more passengers and more baggage. It is possible now for a fairly large family to go on tour with ample baggage without being cramped for room. In the Ford zroup, the coupé has an enlarged rear compartment and an entirely new body design that zives it much more attractive lines. Other im- provements on this model include a wind- shield visor, nickel fittings, new rear fenders, deeper cushioned seats, cowl ventilator, side door that opens forward, and a larger oblong rear vision window. On all Ford models the new radiator sets an inch higher than formerly. An apron on the bottom of the radiator genius of automobile companies joins a similar apron effect of the is giving in the latest models. An Even Choice Often I am asked, ‘What is the best car on the market?” There is no such thing as the “best car’ so far as I know. Certainly, all new features can- not be obtained in any single 1924 model. One car may have one especially good feature, but another car may have an en- tirely different improvement that fully offsets the advantages claimed by the first. Yet it is safe to say that practically every standard 1924 model is reason- ably near in value to the price that is set on it. One would need to write a book to go fully into the whys and wherefores of all the new features that are claimed for the 1924 automobiles. It is possible here, however, to point out enough of the more important being made now. Enough Autos for Everybody HERE are enough automobiles in the United States to carry every man, woman, and child at one time. 13,000,000 cars registered, and trucks, this would mean only about eight persons to each automobile. The average price of an automobile today —about $750—brings the ownership of a car within the income of almost every family. In 1922 more than 2,500,000 cars were manu- factured and the 1923 production was close to 4,000,000. January, 1924, sees the automobile industry the largest in the country. The new car you have ordered probably is Read what Mr. Brokaw, an experienced automobile engineer, about what you will find in it. not ordered a new car, but expect to, Mr. Brokaw’s survey of 1924 improvements will help you make your choice intelligently. features to give prospective car owners a general bird’s-eye view of the situation—to give them a yardstick by which they can measure the value of these new features in the automotive field. Like a yardstick, the mechanical im- provements tound on the 1924 automo- biles are aivided logically into three parts —trs., the body of the car, which shows remarkable results of engineering skill; second, the chassis, which includes such items as brakes, transmission, wheels and tires; third, the engine. New Models Blend Hood and Body The design of automobile bodies shows a decided tendency toward a blending of the hood with the body. Evidence of this fashion is notable especially in the Dodge and Buick. The Buick hes evolved a de- cided change in the hood lines. In addi- tion, it has a larger body, and a radiator of new design. One of the most spectacular of the 1924 changes in body design is seen in the Overland Champion. The versatile per- son will find a wide variety of possible uses to which this new inclosed model can be put. Both the front and rear seats are - with long or motorists short legs. Other cars, the Dodge for example, have removable rear seats, making it pos- sible for a far- mer to carry his produce to market, a housewife to transport the results of her shopping tour, or a business man to cart all manner of goods to cus- tomers. In fact, a noticeable tendency in almost all 1924 models is to provide increased space inside. This assures greater comfort. It enables Convenient With some including buses says If you have rear-end trunks are part of the standard equipment of numerous 1924 models. Here the trunk is shown in use on a Chevrolet sedan fender on each side. This change, in addition to improv- ing the lines of the cars, increases the cooling efficiency. Frames Stiffened In the Star, too, will be found a change in radiator design. The frames of both the 1924 Star and the Durant are stiffened by the “tubular backbone.” This is a metal tube of comparatively large diameter running Jength- wise with the frame. In both the Dodge and the Nash the instruments on the dash have been grouped more closely on a panel. This not ouly improves the appearance of the «instrument board and provides a unit in which all instruments are lighted easily by a single bulb. The same tendency also is noted in some other makes. The Nash Victoria Six has a new body design. Windshield wings and a motom- eter have been made ~\ part of the standard s' equipment of the : Nash sport model. In the Nash touring car are found wi- der and deep- er front seats. The Reo has attained a lower swung body through offsetting the » frame more P. than pre- viously im- proving the appearance. The new Jordan Vic- toria, the Wills Sainte Claire Gray Goose Spe- cial, the Oakland True Blue Six, the Moon Sa- lamancas, the Maxwell Traveler, likewise thenew touring

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RSS Pe Tate Pai es RIMES oR Sac ae 74 Kissel speedster and coupé models, the Cadillac, Case, and Auburn—all have striking improvements in body lines. On the new Maxwell club sedan the two doors, one on each side, have the unusual width of three feet. Each door is mounted on four hinges and opens forward, giving access at once to both the front and rear compartments. In the 1924 Hudson and Essex coaches aluminum bodies are a commendabie feature. POPULAR SCIENCE MONTHLY are employed, and an equalizer between the front and rear pairs of brakes are de- signed to equalize the braking power. In turning corners the outside front wheel revolves faster than the inside one. Therefore, if the brakes were applied equally, the outside wheel naturally would transmit more of the braking power than the other. To overcome this difficulty, the Buick brakes are so designed that the brake on the outside Side curtains opening with the doors, sun visors and windshield wipers are new on the Chevrolet, which, like the Jewett, has made use of a new develop- ment in body finishing. Instead of the usual ap- plication of paint and varnish, a baked enamel finish, such as heretofore has been ap- plied to fenders or mud- guards, is now applied to the entire body. So much for body changes. Chassis Designs front wheel does not operate if the brakes are applied while turning a corner. To Avoid Locking To facilitate the opera- tion of the four-wheel brakes the Packard Com- pany has installed plane- tary gearing attached to the brake pedal. This is so designed that it gives quick action to take up lost motion in the link- age and increases lever- age when the brake shoes contact with the drums. The brakes also are de- Among chassis im- signed so that locking provements, perhaps the most conspicuous is the introduction of four-wheel brakes on Among other improvements on the Jewett, the gearshift lever has been lengthened and _ its angle changed to bring it conve- niently under the driver’s hand the wheels is practically impossible...” For the Rickenbacker four-wheel brake system several makes, includ- ing Buick, Oakland, Cadillac, Ricken- backer, Packard Eight and Marmon. Here is a distinctly useful advance in motor-car construction at a period when the highways are becoming dangerously crowded with motor vehicles. Safety first is the aim of the four-wheel brakes, now that motorists are the chief cause of the 75,000 accidental deaths that occur each year in this country. Four-wheel brakes undoubtedly enable the driver to bring his car to a stop quickly; yet the use of brakes on the front wheels has presented very definite prob- lems, including: (1) The action of brakes must not interfere with steering; (2) The braking effort must equalize properly at all times; (3) The brakes must operate with ease and directness. Solving Mechanical Difficulties Because of the difficulties in solving these problems, some engineers insist that four-wheel brakes have not yet been de- veloped to a point of absolute safety. On the other hand, designers of the cars using the system this year claim that the me- chanical difficulties all have been solved. To assure safety in steering, the front wheels are inclined inward, or under- gathered, and the steering knuckle pins are set at such an angle that they point directly at the spot where the tires touch the ground. This is said to eliminate the tendency to change the direction of the wheel —a tendency that would exist if one brake should hold more than another. Equalizing bars or cables similar to those used when only two brakes step plates, all part of the equipment. the claim is made that whether the car is turning or is on the straight-away, the action of the brakes is unchanged; that the front wheels cannot be locked and that the pressure exerted on the rear wheels always is greater than on the front. Other advantages claimed are that these brakes are automatically lubricated, that they cannot freeze in winter, and that they have the same braking power go- ing backward as for- ward. In. the use of the balloon air-cushion tire at least two manufactur- ers have offered a strik- ing 1924 answer to the growing demand for greater comfort and safety in motoring. The Cole car has adopted these tires as stand- ard equipment. They are found, too, on some models of the Moon. Probably every motorist has observed that when the common pneumatic type of Reo coupé, showing lower slung body, steel disk wheels with demountable rims, and Rear springs of the 1924 Dodge, showing protection for gasoline tank and stop light as standard parts of the car instead of extras Under the rear deck is a roomy compartment tire is inflated to from 40 to 90 pounds, as specified by the manufacturer to insure its full life, it absorbs little of the road’s in- equalities. It is necessary to call upon the springs to take up light and heavy shocks, Balloon tires are expected to eliminate the need of supplementary springs and other shock absorbers. Because they are in- flated at low pressure and have large diameters, these tires, it is claimed, can absorb shocks that heretofore have been passed on to the body springs, and thence on to the occupants of the car. Because of increased surface contact with the road, balloon tires are said to result in increased braking power and less liability to skid. Other advantages claimed are lower upkeep and repair cost, due to restricted vibrations, and de- creased liability to blowouts on account of reduced air pressure. The New Traffic Transmission The outstanding 1924 development ip transmission gears—that unit of the automobile which until now has remained practically unchanged since its inception —is found in the Chandler traffic trans- mission. In this gear, control of speeds is ob. tained through a lever in the ordinary way, but all gears are always in mesh, This feature eliminates the grinding of gears when an inexpert shift is made, and is designed to make driving in heavy traffic easier. It also permits shifting toa lower gear instantaneously without loss of momentum to the car when climbing hills or crossing railroad tracks. Further, it facilitates shifting to obtain braking power when de- scending a hill. As in other transmission sys- tems, all gears are made fast to the jack shaft. Gear Operation The jack shaft is at- tached to the propeller shaft, and all gears may turn freely. To operate first speed gear, for ex- ample, a key or rod of comparatively large diameter slides into con- tact with teeth on the in. side of the gear, with the result that the gear is locked to the shaft. The construction is such that this locking does not be- come effective until a cam on the road is in full mesh with the gear—a feature that eliminates possibility of grinding or of chipping off the edges of the locking parts. The fact that the key comes under a compression, rather than a shearing strain, saves it from wear or breakage. Advantages claimed for the new transmission are these: Elimination of gear clashing and “dub” shifts; the possi- bility of instant change of gears up or down; and of engaging any desired gear under any condition; ease in maneuvering, less skidding; saving of time, nerves, and repair bills. ai im 0 tt tan 2 ek OU ie nthe. oe in a - ae ae

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in- the ks, the her in- rge nan Den nee act less ges ost, de- unt t ip the ined tion ans- ob. nary esh, g of and DAVY toa loss bing ther, »tain de- sys- nade haft. s at- veller may erate r eX- rd of arge con- 1e in. h the ar is ction t be- road ar—a y of yes of e key ‘than saves kage. 1imed ission ation and possi- nange 3; and esired ition; z, less time, bills. The new Maxwell club VA sedan, above, is dis- & tinguished for the un- usual width of its two ees doors. Each door, 3% three feet wide, is mounted on four hinges and opens forward MM, The lines of the Ford coupe, below, have been improved by in- creasing the height of the radiator. Other improvements include a larger rear window, larger compartment and deeper cushions POPULAR SCIENCE MONTHLY 75 ie Se Stee At the left is the new Dodge Brothers tour- ing car, showing streamline effect of the body produced by in- creasing height of the radiator. The body is designed for increased roominess and comfort The general tendency toward streamline effect is shown in the Buick two-passenger roadster, «- model 24-six-44, below. Note how the hood is blended with the body In the 1924 Apperson is found a trans- mission system in which the shift from one speed to another is made automatically when the clutch pedal is pressed. Instead of the usual gear shift lever, a selector handle is placed just under the steering wheel. To shift to a certain gear, the selector handle is moved to the proper . position, the clutch is thrown out, and automatic mechanism shifts the gear. When the clutch is engaged again the new gearing is in mesh. Advantages claimed are that the selector lever is in a more convenient position than the usual gear shifting lever and that the automatic feature eliminates grinding or clashing of gears. This gear shift should not be con- fused with the electric shift already in use, although its action is very similar. Among chassis improvements in the Hupmobile are longer wheelbase and frame, and a marked increase in the length and width of the springs. The new clutch is of an entirely changed design, using two spring steel plates, permitting a more rapid and silent shift. The weight of the driven member in the clutch assem- bly has been reduced nearly 80 per cent, making for ease of shifting. The metal has been strengthened to compensate. The height of the shift lever, now 25 inches, gives greater leverage and con- venience. All gear faces have been en- larged and all gears increased in diameter. The diameter of brake drums has been increased from 12 to 14 inches on the Jewett and the emergency brake has been completely redesigned. All wheels have been made heavier. The front seat has been built to give more foot room for the driver and the gear shift lever has been lengthened to simplify operation. The Dodge chassis has longer rear springs, the front axle has a drop, and the wheelbase has been lengthened. The gear shift and emergency brake levers have been moved forward to give more leg room, the spark and throttle have been made shorter, the wheels are dished, and the splash pan is concave instead of con- vex. The fuel tank has increased pro- tection. ; On the Studebaker, all the surfaces of the crankshaft are machine tooled for the purpose of reducing vibrations. The Oldsmobile has adopted a fabric type of universal joint, which also is found on

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76 some other well known automobiles. A chassis hung several inches lower than on any previous model is the most distinct change embodied in the 1924 Reo. An improved rear axle is a further feature of all these latest models. This new axle effectively combines most ad- vantages of the old full-fleating axle and of the later semi-floating types. Even greater sturdiness is accomplished by the addition to the chassis of a torque rod at the rear. A new device for extracting dirt from the air drawn into the cylinders is found on the 1924 Rickenbacker. It is a well known fact that much of the carbon de- posited in the cylinders is road dust that has been carried in through the car- bureter. To clean the air the Rickenbacker motors are equipped with a contrivance that causes the air to blow against a mushroom-shaped head. The heavy particles of dirt, through their inertia, pass by, while the clean air for the carbureter is taken from the under side of the mush- room, or cap. Fashions in Wheels An increasing tendency to use disk wheels is noted in the 1924 cars. Many models have these solid wheels either as standard or optional equipment. The Stude- baker, Oakland, and Chevrolet are among the newcomers in this class. The Maxwell has changed to straight tire valves on disk wheels. The Studebaker also offers combination tail and stop lights and front and rear bumpers as standard equipment. Another tendency in chassis construc- tion is toward a longer wheel base. Evi- POPULAR SCIENCE MONTHLY dence of this is found in the Dodge, Wills Sainte Claire, and others. The result is said to produce greater beauty of line and increased ease in riding. The new Chevrolet includes the Alemite lubrication system as a standard equip- ment. This means that the old style grease cups are eliminated. A high pressure gun forces out the old grease, cleans the bear- ings and lets new grease flow in. This provides ease in lubricating the chassis and quiet running of the car. Pressure systems of a similar nature are used on other cars, including the Jewett. Distinct novelties in lighting have been introduced on a number of 1924 models. The new Hupmobile engine. showing the improved cooling system. Water jackets surround each cylinder for the entire length of the piston stroke, as well as all valve seats and combustion chambers. A larger hose connection and manifold outlet deliver the heated water more rapidly to the radiator, thus assuring more rapid cooling On some Chevrolet models the headlights are reversible so that light may be thrown on the engine. Also the road back of the machine on either side of the highway may be illuminated. Drum lights have be- come even more popular. While they light the roads no better than other types, they are considered more artistic. The Dodge and Nash models have adopted them. One of the most remarkable improve. ments in engine design is found in the Packard Eight, in which the eight cylin- ders are placed in a single line instead of in the conventional V formation. The purposes are simplicity and accessibility of the engine as well as better body lines, The possibility of transverse and torsional vibration that might be expected in an engine of this length is eliminated by pro- viding a crankshaft of comparatively large diameter supported in nine bearings. The Hupmobile has a new motor, larger and more powerful than before, al- though its weight is only five pounds greater. A sig- nificant innovation is the new crankshaft, which now weighs 5714 pounds, and which has been counter- - balanced statically and dy- namically with great preci- sion. Moreover, the throw has been made straight, supplanting the angle. For a Cool Radiator The Hupmobile camshaft has been made 55 per cent stiffer by enlargement, and its total bearing area has been increased 25 per cent, The cylinder block has been redesigned so that a water jacket surrounds the cylinders for the full length of the piston stroke. En- larged cylinder outlets now deliver the heated water more rapidly to the larger radiator, cooling it more quickly. Another new engine development is found in the

iehnseez., Comparative Use of Motor Cars in Cities and on Farms __ 283228, 360 360 345 , 345 330 CARS PER 1000 PEOPLE ON FARMS AND TOWNS UNDERJ000 330 WRMB CARS PER 1000 PEOPLE IN CITIES OVER 1000 315 315 300 300 285 265 270 NEW ENGLAND | MIDDLE | EAST NORTH WEST NORTH SOUTH ATLANTIC EAST SOUTH SOUTH MOUNTAIN PACIFIC 270 ATLANTIC CENTRAL CENTRAL CENTRAL CENTRAL 255 255 240 240 225 225 210 210 195 195 180 180 165 150 150 135 135 120 120 105 105 90 90 75 75 60 60 45 45 30 30 15 15 3 wi} 3) x2] =) 45] | 3] > i] le =/S/Z2/a/5) |Z = lal. Ht slacleil al slat S}a/AI1a ] [ 2) zy wj> |S] |z]<

“ Jal Elals S ; aysjz = < ola ; s 8]8|Siz}z $ *The figures for Rhode Island and Massachusetts are not comparable with those of other states, since the local basis for census calculations is different. In this chart population figures are based on the 1920 census. Dark lines indicate number of cars in cities; shaded lines, number on farms

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, they Dodge nem, prove- in the cylin- read of The sibility y lines, rsional in an Y pro- atively rted in has a d more re, al- s only A sig- is the +h now 3s, and yunter- nd dy- _ preci- throw raight, ve ator mshaft Pr cent 1t, and ea has r cent, 1s been . water or the En- er the larger nother in the ont. ‘ms POPULAR SCIENCE MONTHLY Reverse, low, and interme- diate gears are the three closely grouped MMB WWW WWWVV_ ww 8 WAN SN QW Above is shown the ap- Buick four-wheel brake to the - The uni- versal joint permits turn- ing the front wheel with- plication of the front wheel. out affecting the rest of the brake. The Buick brakes are so designed that in turning a corner the brake on the _ outside front wheel does not operate when the brakes are ap- plied. There are also four external brakes for service work with an ex- . tra pair of inter- nal brakes on the rear wheels agree The new Chandler traffic transmission. Speed changes are effected through sliding keys that lock gear to shaft. Directly above are two cross section views of the shaft, showing keys in neutral (left) and engaging a gear (right) The new Buick engine, show- ing automatic lubrication to the valve rocker arms. This feature assures a running engine. smoother Other engine improvements include double valve springs, new carbureter and detachable motor arms ROCKER ARM ec, piles th Cut-away view of the 1924 seven-passenger Stude- baker closed car, showing the new model’s roominess Closer grouping of instruments on the dash is a noteworthy 1924 tendency. shown. two of these groupings — on the Studebaker (at left) and the Dodge (at right). Assembly of the instruments on a small panel enables one bulb to light all instruments ZZ i The main { drive gear is at the ex- treme right Directly above are the rodlike, sliding keys that are moved back and forth in grooves in the main drive shaft to lock any desired gear to the shaft. The upper phantom view shows the assembly of gear, grooved shaft, and key The air cleaner _shown above is found on 1924 Rickenbacker mod- els. It is designed to decrease carbon deposits in the cylinders by remov- ing dust and dirt «-from the air sup- plied to the car- bureter. Incoming air is blown against a cap- shaped head that deflects heavy particles of dirt, while clean air is taken in Below are SF es parts. Above is the remarkable new Packard eight-cylinders-in-line engine, showing the simplicity of design and accessibility of While this engine is longer than usual, it does not distort the car’s body lines

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78 Oldsmobile in its Model 30 Six. Here the cylinder block and crankcase are cast in- tegrally. The motor, with detachable L-type cylinder head, develops more than 42 horsepower. The principal improve- ment announced by Chandler for its Pike’s Peak motor consists of a change in the oiling system, which now is entirely a pressure feed. In the Buick engine a removable cylin- der head has been introduced among other motor improvements. Some Overland models have a larger motor. The Maxwell has adopted the Kingston oil vacuum system, in which the gasoline is drawn into the vacuum

tank through a vacuum induced at the oil pump instead of at the inlet manifold. The advantage claimed for this system is that when the engine runs out of oil the vacuum ceases and the engine stops because no gasoline is fed to the carbureter. This prevents damage to the POPULAR SCIENCE MONTHLY

Ra * ; Rd 5 AE «* ae * $ & a * gill or, be 4 * ak 2 3 . 2 ete ~~ et ~ ——O —l—o OOOO ~ — —-« Th A TH TH HO, _ -_ in nh a Se eee | 6 | 6th Gee

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clock, ed (in vision nneau Iso a iveni- dered ndard Es- trunk runks com- ishes, ne de- ; line where Imost yment crific- cuous cially which lilt-in y licate defi- ‘ident otive npos- 2 new liffer- intro- And diffi- many that uring POPULAR SCIENCE MONTHLY 79 By Joseph Calcaterra Of POPULAR SCIENCE MONTHLY’S Radio Staff 700 miles away are received regularly on a high grade loudspeaker through the simple, inexpensive, one-tube radio set illustrated. They come in clearly enough tobe heardin any part of a good-sized room. The secret of the extraordinary results obtained with this remarkable little set lies mainly in an unusual modification of the familiar single-circuit regenerative hook-up. The primary coil is tapped in such a way that it becomes an auto- transformer with separately and inde- pendently adjustable grid and aerial cir- cuits. This makes possible the high efficiency and loud signals of the single- circuit set and at the same time gives the selective qualities of the double or triple circuit hook-up. Using the set within two miles of the two most powerful broadcasting stations in New York City, I have had no diffi- culty in tuning either station in and out at will, without any interference, of course, from near-by sta- tions. The signals on the head phones can be heard across the room and the volume is suffi- cient to operate aloudspeaker. What is far more surpris- ing, however, is the fact that distance seems to make little difference. With an outside aerial 100 ft. long the set also brings in on the loudspeaker stations WDAP and WJAZ in Chicago. Add to these characteristics the important features of low cost, easy construction, and simple control, and it will be seen that this set I have evolved from the ordinary single-circuit receiver is one that is certain to give satis- faction in radio reception. How the selective qualities of the set are obtained is shown in the wiring diagram. The aerial switch can be adjusted to any point on the coil, so also can the secondary B ‘onntesaw programs from stations - Switch. One switch being attached to the aerial and the other switch to the ground post, makes it possible to adjust the aerial either on one side or the other of the ground connection and greatly adds to the selectivity. The variable condenser across the grid circuit aids in close tuning. The number of parts used has been re- duced to the minimum. The complete cost of making the set, exclusive of tube, batteries, and head phones, amounted to less than $8. This is based on the use of a homemade variocoupler. If a commercial variocoupler of the $3 type is used, the cost can be held down to less than $10. The panel is 7 by 10 in., a standard size. In the layout of the parts, shown clearly in the illustrations, A and B are the aerial and ground posts respectively; and C and D are ordinary inductance switches with 5 contact points and 2 switch stops each. E is a variocoupler having from 50 to 60 turns-on the stator and from 35 to 50 turns on the rotor winding. F is a 23-plate variable condenser of the Vernier type. G is the rheostat for con- ° The front of the panel (at right) Showing the few con- trols with which great selectivity is obtained trol of filament current of the tube, the type used depending on the type of tube. H is the tube. socket, which also de- pends on the tube used. J is a combina- tion grid leak and condenser. The grid leak should have a value of from 1 to 2 megohms and the condenser a capacity of .00025 mfd. : J, K, L, and M are the terminals and heads of the screws of the binding posts used as phone and battery connectors. Binding posts of the double connector type are convenient to use; if these are not obtainable, ordinary binding posts may be used. The arrangement of the parts and the unusual sim- plicity of the wiring is made clear in the rear view at the left. Note the home- made pler method of tap- ping the primary, each tap being connected with two switch-points Y SH A me r = “Allt---Nt 8B BATT. Diagram of the hook-up, which is a modification of the siagle circuit The cost of the parts will vary slightly in different localities. The variocoupler should not cost more than one dollar if made at home and a satisfactory commercial coupler can be bought for $3 or less. A dial will cost about 30 cents. A good socket can be had for from 50 to 75 cents. A suitable rheostat will cost 30 cents and a grid leak and condenser about 60 or 70 cents. A variable condenser with vernier can be obtained for $3. The switches, switch contacts, and binding posts . will add another dollar to the and the cost. From $1 to $1.25 will cover the cost of the panel. Making the connections is a simple matter. First con- nect the top end of the’stator winding with one terminal of the grid condenser and leak and with the stator plate ter- minal No. 2 of variable con- denser F. The other terminal of the grid condenser and leak is connected with the G terminal of the socket. The No. 1 switch contacts of both switches should be connected with the first tap from the top end of the stator winding; the No. 2 switch contacts should be connected with the second tap of the winding, and so on down to the last switch contacts and taps. The aerial post is next connected with the arm of switch C. A wire is run to con- nect the ground post, the switch arm of switch D, the rotary plate terminal No. 1 of condenser F,, one of the F terminals of the socket, and the binding-post terminal L. Binding post No. 1 of rheostat G is con- (Turn to page 109)

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i t ee aa PEL oe ser Ee PR LOT es * * wea ee. ee oS EROS Yee eee has 80 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Three Ways of Improving Your Workshop How to Make a Wall Tool Cabinet, a Bench Hook, and a Boring Gage S THE home worker adds to his A collection of tools, the problem of keeping them in order and at the same time instantly available for use becomes more pressing. To leave them scattered about the bench is hard on the tools and harder on the temper; yet if they are put away in a box or even in drawers, they are not so accessible. The happy solution is a wall tool cabinet of ample size, and this the home worker can build for himself with little difficulty and small expense. The cabinet illustrated is especially roomy. It will hold a set ofat least 50 tools so that any one can be selected without hunting for it. It will, therefore, take care of the equipment of hand tools found in the average home workshop. The main compartment is 6 by 24 in. by 2 ft. 6 in.; the door compartments are 5 by 12 in. by 2 ft. 6in. Chestnut or oak is excellent wood for the cabinet, but the builder can use other woods if he prefers. The stock for the tops, bottoms, and sides is 7% or 34 in. thick; that for the shelves and drawer fronts, 54 in.; that for the back of the cabinet and the front of the doors, 3¢ in. (solid or 3-ply); that for the sides of the drawers, 14 in., and for the backs and bottoms of the drawers and for the sliding tray, 14 in. The type of joint illustrated is and clips for tools as desired. Com- mercial tool clips can be used, metal clips made, or wooden racks provided in the way shown. This cabinet was designed especially for POPULAR SCIENCE -MONTHLY by George F. Kaercher, who has been super- intendent of several of the largest wood- working plants in the United States. The working details and complete bill of ma- terials, which are contained in Blueprint No. 30 in the Home Workshop series, will be sent to any reader for 25 cents. On the same sheet are details of two other extremely useful bench fixtures for the home worker. One is a unique combination bench hook, miter block and plain, miter, and the long-miter shooting board. This ingenious fixture could well replace the ordinary bench hook on every home hi} i HN 1 | il) TTT strong and workmanlike; but simpler joints can be used, such as a plain rabbeted joint or even'a butt joint. The corners are greatly strengthened REMOVABLE MITER PLANING BLOCK RAISED FOR PLANING LONG MITERS The combination bench hook, which serves as a miter block, and a shooting board by the use of angles bent from brass, 8 of them being made from pietes 1/16 by 31% by 5 in. and 4 of them 1/16 by 34% by 6 in. Other hardware necessary is six 3-in. narrow brass butt hinges, 4 flush ring pulls, a hook and eye or elbow catch, a cupboard lock and escutcheon, and hooks The cabinet open to show the construction. 3% = workshop bench. The.base, 14 by 10 by 18 in., has fastened to it a top piece 7% by 7 by 18 in., by means of 2 hinges let in flush. This top piece carries the usual bench hook head block 134 by 214 by 7 in. with 2 miter cuts, which should be most carefully made to insure the accu- racy and squareness of the miters. Useful for Planing Rules A removable miter, block, triangular in shape, which is cut from a piece 134 by 5 by 10 in. in such a way that the grain runs parallel to the long edge, can be fastened to the bench hook when necessary by means of dowels. The dowels are glued in the miter block and fit snugly into holes in the top piece of the bench hook proper. This attachment is for planing the ends of miter cuts such as in making picture frames or preparing moldings to be mitered around cabinet work, as in the sketch in the upper right- hand corner. There is still another use for the fixture. That is when long miters have to be planed, as sometimes in cabinet work in- volving long mitered joints. The whole upper part of the bench hook is swung up on the hinges and supported at 45 de- In the large drawer is a removable sliding tray for small tools or screws Each tool in a set of 50 or more is ine stantly available when kept in this com- pact and useful wall cabinet 7] . y . r grees by means of two triangu- lar blocks. These blocks have tongues that slip into grooves, as shown. The edges of the stock can then be trued up most ac- curately by ‘shooting’ them with a fine-set plane. The other fixture illustrated is a gage for boring holes for dowels or preparatory to cutting mor- tises. The ordinary wooden gage of this type is difficult to make be- cause the hole through it must be bored with absolute accuracy. There is nothing difficult in mak- ing the gage shown, however, for the hole is formed not by boring, but by means of two thin wooden pieces and two spacer blocks that can be planed true and square before assembling. Furthermore, it is a simple matter to change the blocks for use in boring holes of various sizes. The dimensions suggested as_ being most generally useful are as follows: Main block 7% by 214 by 43 in.; division strips 3g by 1 1/16 by,2 3/16 in.; back and front caps 4 by 23/16 by2 l4in. The four screws are No. 18 or other heavy screws 2 in. long with the points cut off. If you wish the sheet of details for the cabinet and the two bench fixtures, send 25 cents to the Blueprint Service Department, POPULAR SCIENCE MONTHLY, 225 West 39th Street, New York. Yipes third year of the Home Work- shop Blueprint Service will begin next month with woodworking projects of exceptional interest. Details of a Priscilla sewing cabinet will appear next month. The boring gage ~~ PD ~m 4 —eK eye TD KK A OC ~~

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is ine com: ngus 1ave 3, as tock ac- hem d is wels mor- rage 2 be- st be acy. nak- , for ring, oden n be ling. r to 10les eing ows: ision print ENCE New fork- egin jects of a HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 81 Contest Winners Name Most Useful Tools SCIENCE MONTHLY’S recently con- cluded contest on the subject, ‘““The Most Useful of My Tools,” is awarded to Maj. R. S. Bamberger, of 1016 Sixteenth Street, N. W., Washington, D. C. For many years an army officer, Major Bamberger has made working with tools his hobby. Frequent changes of station, however, have compelled him to limit his equipment to a few of the most useful tools, and in emergencies he often has had to adapt the tools at hand to rather novel uses. Most versatile of all he finds his pliers, as he explains in his prize-winning contribution, which follows: T's first prize of $25 in POPULAR I AM just an every-day amateur with a little mechanical ability and a great love for tools. While I love them all, I have absolutely no hesitation about pick- ing out what, to me, is the most useful one—my slip-joint pliers. It would be much easier to tell you what I have not done with them than what I have used them for. Of course, they have their legitimate uses, but I’m simply going to mention a few of the odd ways in which they have come in mighty handy. Your hammer isn’t at hand—use your pliers. One end of the grip is a fine screwdriver and by extending the other end at right angles, enormous leverage in driving or taking out screws is obtained. As a pipe wrench on small stock I get splendid results. I have used it as a monkey wrench and as a tap wrench. It is a good pin vise; laying the handles between the jaws of a bench vise, the jaws of the pliers will hold any piece of irregular stock; it is a splendid nail puller; I use it to bite off longi- tudinal pieces of small wood stock; wire is cut easily by using it on the shank of a screwdriver, any screw may be driven, or, if rusted in, screwed out. The handle takes out close driven tacks. I have used it as a come-along; it opens screw tops like magic; it bends metal readily; when I can’t find a cork- screw (for vinegar bottles only), I insert a screw in the cork and then pull the screw out with the pliers—the cork comes with it; it takes the place of the mislaid can- opener; in cans that open with a key, whenever the metal strip breaks (and it usually does), the pliers finish the job; it skins insulated wire; the handle acts as a lever in inserting screweyes and in lifting refractory windows; I have opened butt hinges on a locked closet door when the key has been lost. This letter could have been shortened by saying that I use it for everything; as a matter of fact, I am as careful to see that my pair of pliers is in my grip when I am starting on a trip as I am to take my toothbrush along. Now you can see why, without hesita- tion, I call the slip-joint pliers my most useful tool. The winner of the second prize of $15 is W. S. Branaman, of 821 North Lawrence Avenue, Wichita, Kans. His first experience with tools was in helping his father build a sod shanty on a claim in Kansas 60 miles from a railroad. Cowpunching and country school divided his attention until the lure of mechanics drew him into carpentry work. Now he is general delivery clerk in the Wichita post office and has a carpenter shop at home where he does all kinds of fancy cabinet work for amusement. Incidentally, he finds it a profitable pastime. Maj. R. S. Bamberger, first prize-winner, is shown above using his pliers to help turn a stubborn screw. W. S. Branaman (at the left), who won second prize, is tightening a wire fence strand with his * hammer. The third James Gary, used a pipe wrench as shown at the right to save himself from being stalled on an Arizona desert Mr. Branaman’s contribution to the con- test is as follows: I WOULD say the clawhammer is the most useful of any tool I have. It is the only tool you can use successfully to drive all kinds of nails, from a half-inch brad to a fortypenny spike. In using finish nails and in doing any fine work, no tool will take its place. In pulling all kinds of nails, the same rule applies. Nothing will take its place. In taking up an old floor or laying a new one, in taking off an old roof or laying a new one, the hammer is all you need to do the job. If I am laying brick or stone, I use the hammer to break them. If I am making ice-cream, I use the hammer to break the ice. In tak\g down any kind of a frame structure, I use the hammer to loosen all joints and pull all nails. If I want to half sole a pair of shoes, I use the hammer. With the hammer anda nail I can set asaw. If I break or bend a nail in driving it, the hammer is the only tool to take it out successfully. I can stretch a barbwire fence with the hammer. Just catch the claws over the wire at a barb and get a leverage around a post; you can then make it very tight. You can also cut a wire or a nail with the claws of the hammer. If I am plowing and bend a share, I take the hammer and a piece of flat iron and straighten it out. I can take a piece of red hot steel and hammer it out to make a chisel. If I have a bucket, tub, or pan with a dent in it, I pound it out with my ham- mer. In putting up any frame structure you must have a hammer all the time. To put up a brace or take one down, you must have the hammer to do it. In going out late at night if I feel I need some ° protection, I just stick the handle of the hammer inside my belt, the claws catching over the top of the belt. It makes a handy and good de fender. James Gary, of Maricopa, Ariz., is the winner of the third prize, $5. He is another reader of POPULAR SCI- ENCE MONTHLY who makes a hob- by of his home workshop, special- izing on toys and small models. He also does all his own auto repair- in g. The letter of Mr. Gary is as follows: Your prize offer for a letter on which tool I like best prompts me to say that all tools come in handy at times, but’I use my pipe wrench most of all. If a hub cap on the car gets smashed up so badly that it is impossible to take it off with an ordinary hub wrench, I use my pipe wrench. It makes it come off in a hurry. I have used the wrench to take off fruit- jar tops that would not come off in any other way. It can be used to fix up pipe fittings around the house and the well. I have used it to take off the radiator cap of my automobile when it was too hot to handle with bare hands. There are a lot of other uses for a pipe wrench, but I won’t mention them here or my letter will be too long. Instead, I will tell about the most important use I ever had to put my pipe wrench te—a use that saved me from being stalled in a desert. One day, after being over to Phoenix, Ariz., which is about 35 miles from my town, I was on my way home and had (Continued on page 118)

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By Joseph Coudon Instructor of Woodworking, U. S. Veteran’s Hospital No. 81 \ \ 7 ment. their mystery to me. handiwork is If it is because the tools are elab- orate and costly, let me tell you about my own set of tools for shallow carving made at no expense what- ever from cid power hacksaw blades and a fie or two. If it is be- cause the work seems too difficult or tedious, let me cxplain how it can be done with reasonable ease and speed. Suppose you have a pair of plain walnut bookends (walnut, mahogany, oak, gum, and similar hard woods are better for carving than the softer woods) and wish to carve a rosette or circular ornament in the center of each. Probably the simplest type of rosette is one that is chip-carved— made by removing triangular slivers with a sharp knife, to form sparkling geometrical patterns as shown in Fig. 2. The knife can be a regular chip- earving knife for manual training work sold at hardware stores, a 14-in. skew carving chisel, or a chisel made from a machine hacksaw blade. I prefer the shape shown in the second tool from the bottom in Fig. 5. With compass, square, rule, tri- angle, and pencil, lay out on the wood one of the simpler rosettes sug- gested by Fig. 2 and then carve it by making vertical, rocking cuts into the wood to mark the deep points and slanting or paring cuts to remove the triangular chips. Little more difficult than chip carving are line carving and ribbon carving. The former is merely a geometrical design marked out with a

Fig. 3. Two American pieces carved prior to 1700, one a panel from an oak chest with tulip design, the other a desk box of oak and ash HY more home workers do not use simple woodcarving to orna- a .* ‘ " ‘ ‘ yee SQVVr . 4 r ss , petite veiner or deep 1/16-in. gouge. All lines are begun inside the corners and finished toward the corners. somewhat similar, broader and are formed by means of a vertical cut on one edge and a slanting cut made to join it from the other edge— Ribbon carving is but the lines are like elongated chip carving. M., fy, “fs IZ a a NN OOP LE, } Oe Pm : }: ILA SIM Ys \ A F_: a 2) Wal CECT? “I ANSIN WN J Wi 4440S 2? 4A aS

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Next comes the useful type of carving shown in Fig. 3. In this the background Vs vas SNAONSA NINN 4s ek 4-=\ 4 44 AY Uke * be GaN ore ) Pe Woe fT DVN A v ANI “A RUF! - LANL Tay aN NAY poe * “HF, \\ a y a“ io ™s VA IANS: WNP S Z ~ Z Y A WE Y Z g Y oR a Z A Z Z AG 4 PANY we wie ENUZS et 44 Lani J ‘ Dy i Pr hee s Photos Figs. 2, 3, and 4 by cour- tesy of the Metro- politan Museum om Art, N. ¥..C Fig. 2. The home worker will find a storehouse of chip-carving designs in these remarkable wooden mangle boards. They were made in Dutch households in the eighteenth century and required no tools but a knife is first outlined, just inside the lines, with a deep 14-in. gouge, using it like the vein- ing tool in line carving. Then the back- ground is cut out or grounded with paral- lel cuts across the grain made by the same tool held on its side, and the vertical edges are trimmed with whatever gouges and skew chisels are at hand. Whenever pos- sible, use a gouge that fits the curve, as fiddling the work with a number of small cuts is the principal error made by begin- ners. Shallow bent gouges, if available, are used for truing up the background. The background also can be indented, if desired, with designs made by punch- like carvers’ markers, obtainable in many styles, or by a large nail, the point of which is filed flat and then filed deeply in HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Secrets of Wood Carving

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Fig. 1. executed by boys in a woodworking class at Greenwich House, SA a A A ELE OEY SF ft Se

Elaborate carving in Italian style New York City 2 crisscross or checkerboard fashion, From this stage, it is not difficult’ to elaborate the carving in two more ways. One is to carve or model the face of the design, as shown in Fig. 4, - The other is to carve the vertical edges, where the design sinks into the background, with a molding, as in the Gothic tracery in churches. Keeping your tools sharp is half the battle. They are sharpened in the same way as other woodworking tools, but on both sides. After they are ground, the finishing is done on an oilstone and with carvers’ slips— small stones with the edges shaped to suit various gouges and V-tools. The tools are then stropped on leather. The first four tools below are made’ from hacksaw blades; the last is an 6-in. double end, slim taper three- square file, each end ground at ane angle. Handles could be fitted to these, but I prefer them without. * For those who wish to buy a set of tools, I suggest 14- and 3¢-in. straight chisels, 34- and \-in. straight shal- low gouges, a 5/16-in. bent shallow gouge, 1/16- and 14-in. straight deep gouges, a 14-in. skew chisel, and a Yy-in. parting tool. Fig. 4. The simple grounded carving of Fig. 3 may be developed intathe mod- eled carving shown at left

Fig. 5. These five tools are part of a set used by Mr. Coudon for shallow carving such as he has described in the instructive article above

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veloped he mod- carving 1 at left 1e has POPULAR SCIENCE MONTHLY JoHNSON's Woop Dvt Fumed Oak NO. 120 FREE Book on Wood Finishing Gives complete instructions for finishing all wood—hard or soft—old or new. Explains just what materials to use and how to apply them. Tells how inexpensive soft woods may be finished so they are as beautiful as hardwood. This book is the work of experts—illustrated in color. Gives covering capacities, etc. JOHNSON’S WOOD DYE Johnson’s Wood Dye is for the artistic coloring of all wood. With it inexpensive soft woods such as pine, cypress, birch and fir, may be finished so they are as beautiful and artistic as hardwood. Johnson’s Wood Dye is very easy to apply—it dries in 4 hours and will not rub off or smudge— penetrates deeply bringing out the beauty of the grain. ~ Johnson’s Wood Dye is made in fourteen popular shades Fl 6. ©, SOREN, Sati PORE all of which may be easily lightened, darkened or inter- iad ematedbanbadisahalit gic Please send me free and post paid, your instruc- & mixed. Full instructions on every label. g ‘ion Book on Wood Finishing and Home Beautifying. P| pernamrs Me. oe. ca cekccocecceceuunes came i s. C. JOHNSON & SON, Racine, Wis., U. Ss. A. i NAME 6c.cdnL tall tees tin daedeRisbe dink StI see 4 “The Wood Finishing Authorities”’ B appases... 2. 22, 23, bees zat § BRANTFORD, WEST DRAYTON, SYDNEY, ] City & SHS. 6 UCI VES IVS. tS dees kale an i CANADA MDDX. ENGLAND AUSTRALIA ee ee ee ee ee | |

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POPULAR SCIENCE MONTHLY

Better Shop Methods How Expert Mechanics Save Time and Labor

Tailstock Center Simplifies Taper Turning It Has Accurate Crossfeed Adjustment and Attachments for Holding Lathe and Boring Tools O SIMPLIFY the turning of tapers, especially on lathes that have no thoroughly accurate and reliable taper attachment of the conven- tional type, I have developed a taper- turning tailstock center along lines that I believe are unique. Although the accompanying illustra- tions show the attachment as designed for small work, it is by no means a device limited to the amateur mechanic with @ cheap lathe. Made in larger sizes, it will be found of especial value in machine shops and auto repair garages where a large—in fact, an increasingly large amount — of taper work has to be done. In addition, the device has bor- ing and turning heads, simple in construction like the attachment itself, but flexible in adjustment and valuable to a degree that will, I feel certain, be generally appreciated by machinists. The need for the attach- ment arises froin the fact that not all lathes are equipped with taper attach- ments and some that do have them will not turn out accu- rate work except after a num- ber of trials. The attachment is made so that the tailstock center can be thrown out of alinement any desired amount within the limits for which it is designed. This can, of course, be done by setting over the tailstock itself, but the inconvenience comes in placing it back accurately in line. With the taper-turning center this difficulty is eliminated; simply by turning the feed screw until the indicator reads zero on the scale, the center is again alined. How the Slide Is Machined The slide forms the main part of the attachment. A rectangular block of ma- chine steel is finished as shown in Fig. 4, with a tapered shank to fit the lathe tail- stock. The slide is dovetailed to receive the taper center and the boring head, a gib being used at the top of the dovetail slide to transmit the pressure from the binding screw so as to clamp the head in position after it has been set by the feed screw. The feed screw extends from the hand wheel entirely through the slide and rests in bearings screwed to each end. By turning the wheel the screw forces the movable center horizontally along the slide to any desired position, as indicated Fig. 2. The boring head

By B. R. Wicks Engine and Machine Designer

Fig. 1. Tailstock at- tachment as used for boring C SCREW SiG~18THD 4 NY 7 SCALE BRACKET BINDING SCREW Ye -24 THD

PLATE 2°x "AG"

DRAW NUT Se 18 THD "yo

LATHE “

NO. TAPER AND BORING

GIB-ADJUST! SCREWS FEED-SCREW BEARING “3

FEED-SCREW NUT Xe" STD.

Fig. 3. The turning head

Fig. 4. Top and side assembly views of the adjustable taper turning center as designed for a small lathe, with important dimensions

by its location with respect to a scale fastened to the top of the slide. The graduated scale, made of tool steel, is held in place by means of a clamp that is screwed to a bracket in the rear of the slide. Care must be taken in squar- ing and alining the parts. The angles of the slot in the slide must be true 30 degrees. The feed screw, the tapped hole in the center head, and the two end bearings must be accurately in line. The gib is used to take up the side play of the center head and is adjusted by means of four gib screws situated on top of the slide. The center head is locked by means of a gib thrust block and binding screw. The shank that is to fit the taper in the tailstock sleeve must be a tight fit, and must keep the slide square with the . center line. Feed Screw and Scale The feed screw is cut left- hand and the center head, if made the size indicated, is tapped out halfway with a 5/16-in. 18-thd. left-hand tap. The seale is made from an ordinary 6-in. standard scale that is not hardened. It will have to be planed or ground to 11/16 in. wide so that it will fit between the bracket and center head. The Y%-in. slot in the scale is intended to allow clearance for the binder. A thread is cut in the nose of the center head to receive the draw nut that holds the center in place. This is removed when the auxiliary attachments are used. These boring and turning attachments are castings finished as shown in Figs. 1, 2, and 8. The first has three positions for the boring tool—one in the center and one at either side. A setscrew holds the tool when placed in the ceriter position. When in the other positions, the tool is held by clamping together the slotted projections with the clamping screws provided. A setscrew holds the attachment on the center head projection. The turning tool holder, Fig. 3, also fits on the nose of the center head. The fix- ture holds the tool horizontally at an angle with the plane of the slide. Set- screws are provided to clamp the tool in position. ccr- ee Cuoemcn

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POPULAR SCIENCE MONTHLY START THE NEW YEAR WITH A STARRETT CATALOG ¥4 scale The el, is » that n the ;quar- The - glide The ole in vo end ely in ike up r head of four yee You’re going to need new tools this pie coming year. NOW is the time to at start planning. fit the Ff sleeve ff 1 must | Send for the Starrett Catalog. You | ornament h ° . ae e ° i? ne will find it invaluable in making your if harles ~ 2 - it ie a i selection of the tools best suited for Meee f aw. your individual requirements. ead, if . _ is Over twenty-two hundred fine Precision “ye Tools are described in this Catalog. Illus- ” cr trations — uses completely ‘described — scaie ° is tol prices — the newest additions to the Star- paar rett Line — the whole story in its.350 pages. ; scale is , , , yr the Write for it TODAY, Mailed promptly at of the our expense, Ask for Catalog No. 22‘*W” w nut his is lf nments THE L. S. STARRETT CO, hments The World’s Greatest Toolmakers rigs. lL Manufacturers of Hacksaws Unexcelled ons for ATHOL, MASS, ind one egg he tool ne N When “SD” ¢ Showing how the Starrett 1eld by ee oC area: Catalog describes a_ tool ections Oo EY), and its uses. This free ed. A book has the information on the you want, Send for it. also fits The fix- at an » Set- tool in

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iter oe co PP NPE SRN og ae Nites ei ARR ESRC gency 86 BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY APITALIZE On it. Such men as lawyers, bankers, doctors, executives and successful business men consider their personal appearance one of their greatest assets. This applies equally to yourself. Your chance of promotion may depend largely upon your appear- ance. Neat clothes, clean collar, trimmed hair and good taste today help considerably in the making of a business man. Perhaps the most important of these factors is your hair. What is more slovenly looking than when the hair grows down over the collar—and what is more easily remedied? Keep it neat appearing between trips to the barber by trimming it at home. It’s simple and easily done with Brown & Sharpe Hair Clippers—used by barbers the world over. THE CLIPPER YOUR BARBER USES IS THE CLIPPER TO USE AT HOME. Mail Coupon for this FREE BOOK Now! Keep the neck clean. Anyone can do it for you. The tapered effect is just as easy to obtain. baa The side tabs can also be easily trimmed with i the aid of a comb. MAIL THIS COUPON TODAY BROWN & SHARPE Mfs. Co. Providence, R.I., U.S.A. “Brown & Sharpe Mig. Ce., occ: — Please send a free copy of your new Keep a Brown & Sharpe Hair Clipper at booklet, “How to Use Clippers.” home for use between trips to the barber— for trimming the children’s hair or sis- ter’s “‘bob’’ and for use on vacations or when a barber is not right at hand. | accurately centered. The other end of the 1 within \% in. of the proper diameter. Lapping Jaws of a Universal Chuck Is a Simple Process [ aeerne the worn jaws of a universal chuck so that it will run true with the lathe spindle can be done quickly by means of a lap arbor and a pilot bushing used in conjunction with a lathe. One end of the arbor is turned to fit a pilot bushing, which in turn fits into the hollow spindle of the lathe. This bushing is bored after it is in place so that it will be PILOT BUSHING HOLLOW SPINDLE The lapping compound is placed on an arbor supported by a pilot bushing and the tailstock arbor fits into the tailstock spindle. ' A portion of the arbor, left larger than | the rest, is used as the lap. This is covered with oil and emery and brought into con- tact with the jaws and fed in and out by means of the tailstock spindle. Since both jaws and lap wear away, it will be neces- sary to bring the jaws into contact with | | the lap by tightening them. | Soft steel should be used for the arbor and care must be taken not to let any | abrasive get into the pilot bushing. | Shaping Conical Wood Patterns on a Vertical Spindle Sander HoLLow and conical wood patterns can be made without excessive lathe _ work by utilizing a vertical spindle sander as shown. The wood is bandsawed to | Then, for inside work, a crotch is clamped to the table in such a position that the sander will just bear against the surface Finishing the inside of a pattern (at the on and shaping a conical surface (at the right of the wood. The cylinder is turned | around the sander roll until the entire cir- _cumference of the pattern has been | finished. For outside conical or cylindrical work | a board is first clamped to the table, which _ may be horizontal or tilted. In the board from it. A hole is then drilled in the pat- tern to receive the nail. As the pattern is turned about its pivot, the outer surface is accurately trimmed. Both methods are useful in making patterns for cone pulleys. is driven a pivot nail projecting parallel to | the sander and at the proper distance | | | | |

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POPULAR SCIENCE MONTHLY 87 RS) SA Usa. Trade Mark For Best Results in Filing--- OU NEED THESE TWO BOOKS. “File Filosophy” is packed full of prac- tical hints and suggestions as to the proper method of using Files---a gold mine of information for the mechanic or artisan. You can read it in an hour. - “The Nicholson File Catalog” contains six hundred illustrations of perfect files and an interesting history of the world’s greatest _ file and rasp manufactory---a story that reads like a romance. Your name and address on a post card brings you both of these books absolutely FREE--- and without incurring the slightest obligation. Write today. ICHOLSON FILE Co. |

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oo POT a REN Ree BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Mr. Punch— the Automatic Drill No. 185 Price, $2.50 ‘ ; oe ' i ye % z e So By H eee: Loe : ee: Sok it. Ste . = x es 2 BE eS REPAIRING pele FIXTURES CURTAIN =, “T bore holes” says Mr. Punch “Do one thing—and do it well, is my motto. That’s why I specialize on boring holes. I’ve found the way to make clean holes through hard wood without splitting it, through soft wood without mushing it, through plaster without cracking it.”’ Mr. Punch is the Goodell-Pratt Automatic Drill. Inside the handle are eight different size drill points varying from 1-16 to 11-64 inch. You pick out the size you want, fit the point into the chuck, and Mr. Punch bores the hole in a jiffy. All exposed metal parts are pol- ished, nickel-plated and_ buffed. Length, 10 inches; weight, 8 ounces. Sold by good hardware stores everywhere. If your dealer hasn’t it, write us. Write for free Catalog No. 15 Illustrates and describes each of the Goodell-Pratt 1500 Good Tools. Your mame and address on a postcard brings your copy. GOODELL-PRATT COMPANY Greenfield, Mass., U. S. A. GOODELL- PRATT Using the Bar of a Vise as a Press for Bushings A BUSHING press attachment for an ordinary vise is a useful fixture for work too large to be pressed directly be- tween the vise jaws. Two brackets are secured to the vise base, as shown. Two long rods pass VISE BRACKETS HELD BY VISE BOLTS 34 STEEL RODS, THREADED FOR ADJUSTMENT ae 2 ee CEG = wo A fixture for the rear of the vise that extends its usefulness in small press work. One rod is shown broken out for clearness RK IN DRESS through these brackets and through a rear plate. The two rods are so placed that the center of the rear plate is in line with the vise bar. Work is placed between the plate and the end of the vise bar and pressure is brought to bear upon it by closing the vise.—G. A. L. Drill Jig Used with V-Block 0 penerpes centrally located holes in round stock is made easier if a drill jig is added to the usual open V-block. A plate is drilled, bored, and threaded, as shown, to receive a knurled drill bushing. The plate is held down on the hook by ond Z ee Het eo ae hi == ii Jayptet lati w OLI0000F AMAA AR ZA HAA WAZ ihe 2 TAP GAGING PINHOLE : AN v DRILL PRESS TABLE A drill jig with a removable bushing is added to a V-block for drilling shafts and round stock two cap screws, which pass through pipe- sleeve spacers. The bushings are tool or machinery steel, casehardened. When one is worn too large, it can be annealed and reamed to the next larger size. One end of the V-block is tapped for a gage stop rod for locating the longitudinal position of the hole to be drilled.—J. R. Shop Features for February O DRESS the wheel of a surface grinder at an angle by hand is a tedious job and one that no machinist relishes. A simple fixture for doing the work accurately without waste of time will be described next month in the Better Shop Methods Department. Another valuable article will tell how to make a set of surface plates. A non-slip attachment for automatic screwdrivers, a convenient gas shut-off for the shop blower, a slip pulley and gear for preventing tool break on automatic machines, and other labor- saving devices will be described by experts.

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ss | ar he th en nd by in ill as ig. POPULAR SCIENCE MONTHLY qual to All Demands This is Number Four of a Series Every tube you add to your receiver makes it just that much more important for you to use Eveready ‘‘B” Batteries, for each additional tube increases the work the “B” battery has to do. It demands a more capable, long-lived battery. Here is a table that shows just what each type of receiving tube draws from your ““B” battery. The current is measured in milli-amperes, or thousandths of an ampere. Current (in milli-amperes) Taken from the ‘“‘B’’? Battery by Various Tubes “B” | WD-11 | UV-199 | UV-201 JUV-201-A Volts | WD-12 C-299 C-301 | C-301-A 2214 0.5 0.5 0.5 0.5 45 1.5 1.4 1.5 1.5 6714 2.5 2.4 2.5 3.5 90 4.5 4.0 3.9 6.0 Above figures are at zero grid bias The table shows that the “‘B” battery current drain increases much more rapidly than the increase in voltage. For ex- ample, if the voltage doubles from 45 to 90, the current drain increases three-fold in one case and four-fold in another case. This all means that the life of the “‘B”’ battery may be materially lengthened by not using a higher voltage than is necessary to obtain the desired results. The most popular type of receiver today has at least three tubes, operating a loud- speaker. As ordinarily employed, it places a fairly heavy drain on the “B”’ battery. Under light and heavy service, Eveready “B” Batteries prove up. More and more fans buy them every day because they are the most economical. According to the work they have to do, so is their life. You get most energy for your money in Eveready “B” Batteries—they last longer. “the life of your radio” The Metal Case Eveready “B” Battery, No. 766. The popular 2234-volt Eveready Battery in a new handsome, durable, waterproof metal case. At all dealers, $3.00. Eveready “‘B” Bat- tery No. 767. Con- tains 30 large size cells, as used in the popular No. 766. Voltage, 45. Made especially for sets using detector and one or more stage of amplification. The most economical “‘B” Battery where 45 volts are required. At all dealers, $5.50. Eveready Radio Battery No. 771. The Eveready “Three.” The ideal “‘C”’ Bat- tery. Voltage, 414 — three terminals permitting the use of 1144, 3, or 4% volts. The correct use of this battery greatly prolongs the life of the “B” ‘Battery. At all dealers, 70 cents. Manufactured and gueventeed by NATIONAL CARBON COMPANY, Ine. Long Island City, N. Y. EVEREADY Radio Batteries —they last longer Note: This is Number 4 of a series of informative ad- vertisements, printed to enable users to realize the utmost in battery economy. If you have any battery problem, write to G. C. Furneses, Manager, Radio Division, NATIONAL CARBON CO,., Inc. 116 Thompson Ave., Long Island City, N. Y. Ask for special booklets on “‘A,” “B’’ and “C” Batteries.

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sence MEY

BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY

‘‘Here’s the panel I want”’ The panel is the “front door” of your radio set. The selec- tion of the panel is an impor- tant step. You want a good- looking panel. And you want a panel that has high dielectric strength. Your Celoron panel comes wrapped in a dust-proof glass- ine envelope. Dust and grit cannot scratch it. Human hands cannot ieave greasy finger prints on it. Because of its high dielectric strength, Celoron is approved by the U. S. Navy Depart- ment Bureau of Engineering and the U. S. Signal Corps. Celoron radio panels are fin- ished in black, oak, and ma- hogany. ‘They come ready to use in these standard sizes: 1...6x 7x 5... 7x18x3/16 2k x 9x36 6... 7x21 x3/16 3...7x12x\% 7... 7x24x3/16 4...7x14x3/16 8...12 x 18x 3/16 9...7 x 26 x 3/16 Other sizes are cut to order from sheet Celoron. Ask your dealer. An interesting booklet for the radio set builder is ‘Getting the right hook- up.” This booklet is sent free upon request. To radio dealers: Send for special dealer price list showing standard assortments Diamond State Fibre Company BRIDGEPORT (near Philadelphia) Offices in Principal Cities In Canada: Diamond State Fibre Company of Canada, Limited, 245 Carlaw Avenue, Toronto CELORON

STANDARD RADIO PANEL

PENNSYLVANIA

aa

How To Make Things Electrical This book gives directions for making hundreds of electrical appliances and devices for the home, the shop and the garage. The simple directions and many drawings make the work easy. 429 pp. ‘Price, $1.50 postpaid POPULAR SCIENCE MONTHLY 225 West 29th Street, New York City

inches, $1.00 postpaid.

The Vest Pocket 4, °2""<.2"4 of practical BOOKKEEPER tociiceping, with short cuts in figures and complete instructions for the correct keeping of books of accounts. A working model adapted to the novice and business man, by F. M. Payne; 160 pages, size 3x6 POPULAR SCIENCE MONTHLY 225 WEST 39th ST., NEW YORK

Flat Forming-Tool Holder Will Be Useful in the Shop HE forming-tool holder illustrated will be found useful in almost any toolroom where forms and models must be made with great accuracy and be duplicated from time to time. The construction of the holder is obvious from the details, but a word may be added in regard to the tools made for use with it. The forming tools are made of flat tool steel and are shaped either to fit a model or made up to suit the drawing. The various radii should be stamped on the tools before they are hardened, as well as the name and number of the model or

3 s% - { %4 x20 THD TAP ‘« a % : ames.) FORMING TOOL hoot Se BOLTED TO SIDE OF HOLDER “2x13 THD TAP, rT

\ TT \ Niji | Ah ie ae a4 CIRCULAR FORMING TOOL 4+ 73 CLEARANCE

HOLDER , .* SMALL CIRCULAR FLAT TOOL fy DRILL FORMING TOOL Details of the tool holder and several types of forming tools used with it

drawing they are intended to be used with. After the tool or set of tools has been used, it should be turned into the model or toolroom crib and stored for future use. The tools will last indefinitely when they are called for only occasionally, as is frequently the case, but an accurate record should be kept so that it is always possible to tell what tools are on hand. Circular forming tools can be sharpened without changing their form.

Bench Fixture Saves Time in Laying Out Angle Irons

2" «/2" CHANNEL?” Wyren laying out small angle irons, difficulty is often found in holding them in place so the flat surface will be up. A simple bench fixture can be rigged up to do this by fitting two pieces of 4 by 3 by 5/16-in. angle iron into a 2 by \-in. channel, 9 in. long. The slotted holes in the legs allow adjustments to be made to accommodate angle irons of varying thickness. — O. W. MIELENZ, Phila- delphia, Pa.

\ as AL OAMlClelURUlUCUrKTUCUCONQND

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jE BOLT irons, olding vill be rigged f 4 by Y-in. sles in made arying Phila- POPULAR SCIENCE MONTHLY 91 a oe oA Write us a post card— _ Address Dept. 5-R and we will send you free this 52 page catalogue of radio sets and parts. It also contains explanation of radio terms, map and list of broadcasting stations and much radio information, including an explanation of successful hook-ups and circuits. You will be amazed at the low prices ce AER} WARD € co |/ Ward’s quote. A complete tube sect ==— Paul Portiand o, ; having a range of 500 miles and more, ' including tubes, head set, batteries, and antenna equipment, as low as $23.50. This catalogue contains everything for the expert and amateur. Complete sets and every improved part for building sets, all the most up-to-date de- vices—at the lowest possible prices. Headquarters for Radio Montgomery Ward & Co. is headquarters for Radio, selling everything direct by mail without the usual “Radio- profits.” Why pay higher prices? Ward quality is the best and the prices will often save you one-third. Everything sold under our Fifty Year Old Guarantee,—Your Money Back if You Are Not Satisfied. Write today for your copy of this complete 52-page Radio Book. Write to our house nearest you. Address Dept. 5-R Chicago Kansas City St. Paul Portiand, Ore. Ft. Worth Montgomery Ward ? G The Oldest Mail Order House is Today the Most Progressive

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SMAPS ES TIN NT ND eee eee = Si a en ee Nate Bees See ee ae ENR Re a Giving the Telephone Life Wherever your thought goes your voice may go. You can talk across the continent as if face to face. Your telephone is the latch to open for you any door in the land. There is the web of wires. The many switch- boards. The maze of apparatus. The millions of telephones. All are parts of a country-wide mechanism for far-speaking. The equipment has cost over 2 billion dollars, but more than equipment is needed. There must be the guardians of the wires to keep them vital with speech-carrying electrical currents. There must be those who watch the myriads of tiny switchboard lights and answer your commands. There must be technicians of every sort to construct, repair and operate. A quarter of a million men and women are united to give nation-wide telephone service. With their brains and hands they make the Bell System live. “BELL SYSTEM” AMERICAN TELEPHONE AND TELEGRAPH COMPANY AND ASSOCIATED COMPANIES One Policy, One System, Universal Service and all directed toward Better Service . The Midget “‘Five-in-One’’ Slide Rule \ ies a gombination. mage > Polymet- \\ and oe tract Slide ale. mit will hs fnstantly od subtract, multiply and divide any = bination of whole numbers, fractions, mixed numbers and decimals. Gives Ti] eve Srimtser wer, also 8, Sines and Tangen ade of aluminum with scales on white celluloid. Size 4 in. Approved and adopted by colleges. Pricewith Instructions, $1.50. th: Case 50c extra. Catalogue Free. TOOL CASES for MACHINISTS and TOOLMAKERS —k Gown in our new 1924 cohow Thirty styles and sizes own. A postal brings H. GERSTNER & SONS (Patented 1-17-22) Gilson Slide Rule Co. ,Niles,Mich. 501 Columbia St., Dayton, 0. Develop Your Ideas at aras With the help of a Boice Junior Bench Saw D° your ripping, mitering, grooving, rabbetting, tenoning, sanding, L-"] grinding, and many other operations with surprising ease and accuracy. Top 10" x 13". Saws 1%%"' stock. Dadoes 5%" x 5%", Machine built entirely of metal. Extremely accurate. Driven by \% or % h. p. motor. Portable. Attaches to any light socket. Write for descriptive literature on Boice-Built bench saws, lathes, drills jointers, band saws, and motors. W. & J. Boice, Dept. P.S.-1, 1730 Norwood Ave., Toledo, Ohio ———__ | Getting the Most Out of Your Lathe Tools By Joe V. Romig Machine Tool Builder and Designer ReVERY machinist will be interested ia this article on the controversial] subject of the solid forged lathe too] versus the toolbit. Whether you agree with Mr. Romig or not, write briefly the conclusions you have reached on this subject from your own shop ex- perience and address your letter to the Editor of the Better Shop Methods Department, POPULAR SCIENCE MONTHLY, 225 West 39th St., New York. If your letter is of sufficient gen- eral interest to warrant its publication, you will receive our usual rate of payment for it.—THE EDITOR. Hew often have you seen machine operators using toolbits and hold- ers simply because they are less expensive than solid forged tools? This is a penny saving and dollar losing proposition in many cases, particularly if the tools are for roughing work. The duty of a roughing tool is to make the first cut on a rough casting or forging, and, as the surface is usually covered with scale and dirt, the cutting edge quickly becomes dull. Consequently a large amount of heat is gener- ated and this must be carried away from the cutting edges of the tool or they become too hot and lose not only their tem- per and hard- ness but their cutting edge. A tool of large cross section will carry away and dissipate much of the heat and there- fore stands up better than toolbits held in tool holders or built-up tools made of welding bits to soft steel shanks. Although the solid tool is the logical tool for roughing operations, some me- chanics seem to learn better by experience than logic, and on one occasion the writer saw the solid tool triumph over the toolbit in a rather spectacular way. A big battery of motor-driven lathes turning shrapnel cases had been tooled up with tool holders and round toolbits held at an angle, as illustrated on the next page. The metal to be taken off in roughing was tough and full of scale. The fact was that the cases had been heat treated after forging to increase their strength and bring the elastic limit of the steel up to the required specifications. After laboring along for several weeks with poor results, the plant suddenly be- gan to show increased production on sev- P eral of the lathes. Upon investigation it was found that the operators had dis- carded their toolbits and substituted solid tools, which they had borrowed from empty machines assigned to a different operation. The big, husky roughing tools carried away the heat and stood the gaff of the heavy- cuts. After-that, all the lathes were equipped with solid tools and production jumped to the maximum. (Continued on page 94) Rough turning »

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of igner rested Versial 1e tool 1 agree briefly hed on Op ex- to the ethods ‘ENCE , Ne ew rt Sen- ation, ite of achine hold- ensive penny ion in Is are make rging, d with uickly olbit athes ed up ; held page. r was | that after and o the yeeks y be- sev- on it dis- solid from srent tools gaff - the and POPULAR SCIENCE MONTHLY at home Macnavox | gives you the melody | of concert and opera HE secret of the marvelous results ob- tained with Magnavox Reproducers does not lie in any one feature (such as the shape or material of the horn) but in the correct working out, in all features, of correct scien- tific principles. No receiving set is really complete without Magnavox. Magnavox Reproducers horn and 1 stage of amplification R2 with 18-inch curvex horn $60.00 $59.00 R3 with 14-inch curvexhorn $35.00 2-R consisting of electro-dynamic M1 with 14-inch curvex horn Reproducer with 14-inch curvex 4 horn and 2 stages of amplification Requires no battery for the field. $35.00 $85.00 M P. Ampli Magnavox Combination Sets Prive + “ g es F " =i, A1-R consising of electro-dynamic AC-2-C—2-stage. . . . $55.00 Reproducer with 14-inch curvex AC-3-C—3-stage. . . . $75.00 Magnavox Products are for sale at Registered Magnavox Dealers everywhere. Write for new 32-page Magnavox Radio Catalogue. THE MAGNAVOX CO., Oakland, Calif. New York Office: 370 Seventh Avenue Perkins Electric Co., Ltd., Toronto, Montreal, Winnipeg, Canadian Distributors _# ways

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SS TPE IIE 94 BETTER SHOP METHODS DEPARTMENT OF POPULAR sCIENCE MONTHLY Then Fread This/ Look in the tool box, or under the seat of practically any motor car and you will probably find there —~VIchek Tools. Our name won’t appear on them, for this is not permitted, but nevertheless they are Vichek Tools and the kind of Tools which we would be proud to stamp with our name. In 15 short years we have becoine the largest tool kit manufacturers in America and that means, in the world, The reason? Great capacity, certainly, and advanced equipment through which we are enabled to secure the lowest possible cost. But there’s still another reason. The advanced Vichek Pro- f ) 7 pendable, so thoroughly cess is so accurate, so de- efficient in a mechanical and engi- neering sense, we are enabled to produce Tools that, for every prac- tical purpose, are without a superior whether Ball Pein Hammers, Cold Chisels, Screwdrivers, Wrenches, Valve Lifters, Bearing Scrapers, or anything else. A Vichek Tool, whatever it may be, has the utmost of strength in it; the maxi- 5 mum of sweet tempered liveliness and balance. Its design is perfect and it provides for a hand comfort that makes it easy to use for hours at a stretch. It’s a tool that the shrewd mechanic, as soon as he takes it in his hand, will recognize as one which will stand up to his work. A tool, in short, upon which we are glad to place our guarantee and this means imme- diate replacement if one goes wrong. THE VLCHEK TOOL COMPANY, CLEVELAND, OHIO EASY TO SAY VELCHEK VLCHEK TOOLS MADE BY THE WORLD'S LARGEST PRODUCERS OF TOOL KITS Saw Filing Pays Buy a Foley Saw Filer and Setter and establish anin- dependent, profitabie business. — Write today for FREE Catalog. Territory open to interested parties. , FOLEY SAW-TOOL CO. 3613 Portland Avenue MINNEAPOLIS, MINN. R BETTER RESULTS — F RAMINGHAM pai { LUXE _PARTS In Your Home | er) Our marvelous prac- tical Movie Ma- ceili sell as low as $5.00— and what's more, we have a ful films at lowest) Prices—with a film rentals orien Don’ tMiss This! ; Wri r Free Catalogu PARAMOUNT MFG. COMPANY ox 1371, De ons P.Ss. _— Boston, Mass., ru. s. COLD PIPE BENDERS Standard of the World. HAND and MOTOR OPERATED 14 Sizes of Machines What it coats be bend pipe our baat he rt x es * Dipe 25 cents cents w* * pipe 10, 0 cents 6°” pipe 60 cents 8”’ pipe 31% Send for Catalogue. AMERICAN PIPE BENDING MACHINE co. S51 . Mass. joston. Mass. __ Your Lathe Tools (Continued from page 92) Part of the work was later subcon- tracted to an out-of-town firm and the rest of the forgings were sent to them from our own forging plant. This firm also had its troubles, and, not being able to get any production on the rough turning, com- plained that the metal was too hard and tough to turn and burned up the tools. After a random selection of shell cases had been returned to us with the state- ment that they were too hard to turn, the president of the company himself paid us a visit. He found we were running on a sur- face speed of around 30 ft. a minute, while in his own shop a speed of 60 ft. a minute was demanded of the operators. We used a heavy feed of .09 in., while the “ARGING Pg "5" H CLAMPING 6 ROUND SCREWS OOUBLE END TOOL BIT ne re SOLID TOOL Ae ~~ TOOL BIT AND HOLDER The solid tool for rough turning and types of toolbits and holders for finishing cuts feed in his shop was only 1/64 in. We were using our heavy tools of 1 by 14 in. cross section; his men, 3¢-in. square toolbits in regulation type tool holders (see A and B above). We turned our cases to size with one rough and one finishing cut, while they had great di_iculty in even starting a roughing cut, let alone finishing it. After he returned to his own fectory and put in solid tools with a slower speed and correspondingly heavier feed, “the work was handled successfully. In all big steel mills one will see the solid tools used in roughing operations in preference to the toolbit and holder and, in my opinion, it should be the policy of every shop doing rough turning and plan- ing to supply these tools, even if they cost quite a bit more. The small bit and its holder have a valuable place of their own in the finishing of all kinds of work. Tools of many shapes are required in finishing, “and the small toolbit, being ground easily, meets the bill exactly, especially when used in a univer- sal tool holder. For quick, efficient and low cost tool service, the toolbit is ideal for finishing after the big, solid tool has done the rough work. On fine tool work, where accuracy and finish are absolutely essential, the solid tool must be used. For these tools, a high grade of carbon steel is preferred to all (Continued on page 95)

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BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY 95

Your Lathe Tools (Continued from page 94) high speed and self-hardening grades. This is because the carbon steel takes a finer edge than it is possible to get with the more open structure of the high speed steel. Form tools made of carbon steel will hold their shape and edge through the process of hardening, if not overheated. Practically all high speed steels will scale from the high heat of the furnace and always should be ground to shape to re- move the scale. Common sense practice for a machine operator is to gather a collection of good roughing tools of the solid type and fall back on the toolbits for finishing work.

Fastening Crank Handles ACHINISTS and toolmakers fre- quently are annoyed by the ease with which crank handles slip off the square end of the feed screws on milling machines and other machine tools, and drop to the floor. Two simple methods of preventing this are illustrated. Figure 1 shows how a groove is chipped out of the square hole in the crank handle,

ary Uyza) ‘ ‘

i BACKING

SCREW FLAT SPRING —COIL SPRING SCREW = a Ty U Ses ‘ VY WY, Y AG Y “Y Y//p/ ‘id Yy WY) ei aly Y Sit “Yj Y 4

FIG.| FIG:2 A flat spring (at left) and a coil spring and ball (at right) applied to machine crank handles and a flat spring is inserted to hold the handle in place. Figure 2 shows what is perhaps a better method. A ball is pressed against the square shaft by a spring, the tension of which is controlled by a backing screw.— C. M. Wiucox, Torrington, Conn.

Combination Caliper for Inside and Outside Measurements

HIS combination outside, inside, and hermaphrodite caliper has proved popular in the shop. When used as an inside caliper, the hermaphrodite leg is turned back and in some instances forms a convenient handle, especially when reaching into very deep, small holes or getting into awkward places. The dimen- sions shown on the illustration can, of course, be varied to suit individual needs. —WALTER WELLS, Zanesville, Ohio.

‘“‘The Third Hand with the Mighty Grip”’

This handy vise, with swivel base, can be adjust- ed at any angle for any kind of work—‘‘Bull Dog’’ Jaws—for ‘all-around’ use.

| VISE | OW about those little jobs you were going to do on your car? Have you been delaying because you need a vise—the most necessary tool on any work bench? The two Prentiss Vises shown here are especially de- signed for the motor car owner who has his own work- bench. The cost of a Prentiss Vise is very slight compared with the saving you will effect on small jobs—and it will last you a lifetime. See a Prentiss Vise—‘‘The third hand with the mighty grip’—at your hardware dealer’s today. If he doesn’t have them in stock fill in and mail the coupon below. v4 of ¢ i Prentiss Vise Company Fe : 106-110 Lafayette St. FA ee N i s ew York City yf ‘ Rs > & . a eo 4" ° o ~ @ Pe oS 7 Ad re ca $ o APS Se 0 Pa &<$ Prentiss Patent Self Adjusting 7 A a Me Jaw Leng omeoed = Le PA ? Se : sna wi sit % ann “The Saeed type of Ps Ps o,% eo vise made. Steel jaw faces in- terchangeable ; 4 *

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Ie MEET IIE ATE mG AA A OL A wy de ek 2 + (ae BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY The Master Tool for Production-Building You can develop machines that do their work automatically. But none do their best auto- matically. That “best” may be reached by recording the best you begin with —progressing then to higher rec- ords by improved mechanics and operating methods. Your out-of-ordinary production is built up and kept up by records. And your master tool for building them high—is a YRR COUNTER The small Revolution Counter be- low registers one for a revolution of a shaft, recording a machine operation, or product. Though small, this counter is very durable; its mechanism ‘will stand a very high rate of speed, making it \ especially — suit- | able for light, } fast-running ma- chines and most adaptable to ex- perimental work. If run backward the counter sub- tracts. Price $2.00. (Cut 4-5 size.) Small Rotary Ratchet Counter, to register reciprocating movements of small ma- chines, also $2.00. The Revolution Set-Back Counter below records the output of the larger machines where a shaft-revolution indi- cates an operation. Sets back to zero from any figure by turning knob once around. Supplied with from four to ten figure-wheels, as re- quired. Price with four figure-wheels as illustrated, $10.00—subject to dis- count. Cut less than one-half size. Set- Back Rotary Ratchet Counter, to record reciprocating movements as on punch presses, $11.50 (list). Everything you could ask in a counting device is shown in the 80-page Veeder booklet. It’s more than worth writing for. TheVeeder Mfg.Co., 44 Sargeant St., Hartford, Conn. Special Tool Holder Aids Taper Work on Dies [N MACHINING blanking dies many odd shapes are encountered and these call for specially shaped tools. To forge these tools from square or flat stock costs too much, and the ordinary tool held in the shaper head is not adjustable. These difficulties can be overcome, however, by the use of the special holder HOLE TO Sui? ty ORILL a $s CLAPPER BOX y ‘ o :% “TOOL=% ORILL ROD . “MACHINE STEEL Ar MUST COME BELOW | “ CLAPPER BOX Working drawing of the tool holder and how it is used with drill-rod tools M6 SLOT shown. It is designed for tools forged from %-in. drill rod and allows them to be turned to form the various shapes required. Drill rod tools are handy for this work, not only because they are a grade of steel of known reliability, but also because they take up a good deal less room than an equal number of rectangular tools. Crankshaft Bearings Are Trued with Simple Lapping Fixture ae it is generally known that the connecting rod bearings on the crankshaft and the main crankshaft bear- ings wear oval after a period of use and this eccentricity does not provide a perfect seat for the babbitted bearings, repairmen rarely attempt to true up these parts. A method one repairman uses with sat- isfactory results is shown in the accom- panying illustration. A lapping fixture is 7— HOSE CLAMPS \. SAW FRAME Two BABBITT / BEAT'NG HALVES CRANKSHAFT Fr BELT LACE The lapping members, formed of Babbitt bearings, are revolved with belt lace and hacksaw frame made of two cast Babbitt bearings re- moved from the rod and cap of a connect- ing rod or from the bearing and cap of the cylinder block, and the inner surfaces are charged with emery. These sections are clamped about the crankshaft with two ordinary hose clamps. A length of belt lacing is then fixed in a saw frame and looped around the improvised external lap and used to rotate it, as shown. The method is simple and the time reauired for lapping is comparatively short. "EM FROM COAST TO COAST Clearly and distinctly, too! For our users tell us that Cincinnati hears Frisco, Denver hears Schenectady, New York hears Havana! Scores of long distance records were made on these instruments last year so with the many new refinements incorporated the result obtained now will be far better than ever. HIGHEST QUALITY AT LOWEST PRICE This has always been the MIRACO key-note and the thousands of sets now in use are a fitting tribute to MIRACO’S excellent performance. Many new improve- ments, such as new sockets resting on shock absorbing pad—a refinement found only in the most expensive sets—rheostats with multiple resistance windings, mak- ing it possible to use cither dry cell or storage battery tubes, and a new aluminum shield that prevents an- noying body capacity effects, are embodied. Cabinet is of solid mahogany—workmanship the finest —operation extremely simple yet always dependable. 2 tube outfit, shown above__-.-.------- $29.50 4 tube outfit, shown below 54.50 Write for our new bulletin to-day. DEALERS—JOBBERS. Write for our proposition quickly. AGENTS: wire, There’s still some territory open—vwrite or THE MIDWEST RADIO COMPANY 808 Main Street Cincinnati, Ohio “ITS A “Exactly what I wanted —the whole family will enjoy radio now!” Several’ thousand lovers of real radio will say something like that Christ- mas morning when they open a package containing “Morrison Loud Speaker.’’ Give a Morrison and you are sure to please. Attach to ng phonograph or use it with a horn. Morrison is the Loud Speaker that reproduces music and voices naturally without vibration—as loud as you like it. You can adjust tone soft or loud by simple turn of thumb screw on back—no other adjustment necessary—nothing to break or get out of order. We guarantee you money back if not satisfactory. Complete with 5-foot cord Nickel Plated Model, $10 Gold Plated Model, $15 If your dealer doesn't carry it order direct from factory Beautifully Illustrated Catalog free on request. Be sure to stock up now for Holi- DEALERS. day business. Orders filled in turn as they come in. Christmas sales will break all radio records. Wire or write today for our special offer. 2] MORRISON LABORATORIES, INC. Uy 341 Jefferson Ave.,*East, f DETROIT, MICH. ~"$ 10.90 Comptere Loud Speaker

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“S' ami od &20tce ™I == fl ' BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY 97 Hinged Angle Iron for Machining Angular Work By Henry S. Laraby HEN work is to be held on a ma- chine tool at some angle other than 90 degrees, an adjustable angle iron is a decided time-saver. Few mechanics, however, own or use a hinged angle iron. \ sh —S GRINDING CENTERS i mig - ® [o]s 3 Toe eas F 4 S-WTHDS-L 3°y The assembled angle iron with the parts numbered for identification, and corre- sponding details of the parts Those who wish to add such a fixture to their tool equipment will find that the de- sign illustrated is strong, simple, and adapted to all ordinary uses. The iron consists of two hinged plates, four clamping arms, and the necessary bolts, washers, and nuts. Both the ad- (Continued on page 98) that you may have. LY: NY « Yj v = —e wy: = Bf x hdl | me wa bl : 4, Vv Ay Te sasauhaal Le i@ Ly Uy, Ly Choose Working Partners From This List They'll Work a Week Free! A DIME A DAY WILL KEEP THEM Carpentry and Contract- ing, 5 vols., 2138 pages, 1000 pictures. Was FST SOLNOW 2... vccccss $19. Civil Engineering, 9 vols., 3900 pages, 3000 pictures Was $67.50, now..... $34.80 Electrical Engineering, 8 vols., 4100 pages, 3300 pictures. Was $60.00, een) eae eae $ Automobile Engineering, vols., 2600 pages, 2000 pictures. Was SE5:00) OW. 6..6 65:0 3% $21. Machine Shop Practice, 6 vols., 2300 pages, 2500 pictures. Was $45.00, PUVOE 5.510; sae S.sieisre osve8. $24. law and Practice (with free reading course), 13 vols., 6000 pages. Illus. 29.80 Was $97.50, now. . .$49. 80 Fire Prevention and In- surance, 4 vols., 1500 pages, 600 pictures. Was $30.00, now...... $14.80 Telephony and_ Teleg- raphy, 4 vols., 1728 pages, 2000 pictures. Was $30.00, now..... $14 Sanitation, Heating and Ventilating, 4 vols., 1454 pages, 1400 pic- tures. Was $30.00, now $14. Business Management, 8 vols., 2500 pages, well illus. Was $52.50, now. $29. Drawing, 4 vols., 1578 pages. 1000 pictures, Blue Prints, etc. now... - $14.80 Keep Experts at Your Elbow Until You Are Expert Yourself The up-to-the-minute action of the Ameri- can Technical Society has gathered the work of more than 200 of -the world’s greatest experts who have contributed their know}- edge, their great experience and practical advice to help ambitious men get ahead. Each tells you all about that line in which he is a recognized authority and so hélps you to become an expert yourself. ° Don’t Waste Time Working Problems Alone Here are hundreds of experts ready to work with you—at least twenty in your own line. They help you become the right man for the next big job—you'll be the one who will be singled out from a number of capable fellows because you'll be the man who knows. Remember the: big- money goes to the men who are ready. Seven Days’ Free Trial That you may test these books in every way—use them as if you owned them;— show them to your friends or the men for whom you work— get their opinions—in other words to prove to you that these books can help you with all your problems—the books are sent for absolutely free examination. Don’t Send Any Money. The Society seriously wants you to be certain of the big value the pay-raising books present. They. want you to be as sure as are the thousands of members who are now growing by the help of the books .and the consulting membership. That’s why they gladly send any set you want—they know you'll see the volumes are worth in- finitely more than is asked and want to become one of the men who grow because they know. You'll Raise Your Pay For a Dime a Day If you keep the books just pay $2.80 within a week and send $3.00 a month—just i0 cents a day—until they be- long to. you. . Send in the coupon now and know more than the other fellows on your job. FREE CONSULTING MEMBERSHIP A resident consulting staff of from 15 to 20 practical experts is waiting to-solve for you any difficulty A letter or a wire to American Technical and the solution to your problems. library will enable you to handle successfully any job in your line. and the newest and best ways of doing things. PARTNER. Use this service daily if necessary. Society will bring you an immediate answer This advisory staff of practical men plus your working and reference These men know all the latest methods Let this pay-raising consulting staff be YOUR SILENT This free consulting membership offer is good for a limited time only and can be withdrawn without notice. American Technical Society, Dept. X120, Chicago, U. S. A. | Pe OS OS OSS SS SS SCS SSSS SESS SOS8 See e228" Dept. X120, Chicag Please send me a set of "REE EXAMINATION, shipping charges collect. ‘Oo AMERICAN TECHNICAL SOCIETY, a eh a:n:/d(eaidl ore ore! wie: t so bk i erein emia ee aaa TRE 6 aaa ae for seven days’ « I will examine these books thoroughly, and if satisfied will send $2.80 within seven days and $3 a month until I have paid the special price of $..... 3 If I decide not to keep the books, I will return them within one week at your expense. It is under- a stood that if I keep the books I am entitled to a FREE Consulting Membership inthe.............. 4 % division of the society. a PON asec seo ocho Old NEG S Givin sole Mew Slelp wwe ee we dle etary doe baad wi olatelwatls © alia: «ace a ane eee a SN i 4 asec ls no:¥ @:6'b1b.0: 1850-9509: mn 0G .p:e 9 4-0'T Wile wR lees SiS 6 9 "are ace om sac aie kcal ata i 3 ee ee eee ee a ee nee” a mE PRE I z (Please fill out all lines, give local merchant, banker or employer as reference.) e ee TT eT UG

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98 BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY Easier to build Radio Sets “YANKEE” Ratchet Screw-drivers HAT new set that you are planning will be easier to make if you let “Yankee” Ratchet Screw-drivers help you do the job. The “Yankee” Ratchet eliminates the tiresome grip-and- let-go. One good grip and the screw is driven home. No. 10 (illustrated) comes with 2, 3, 4, 5, 6, 8, 10, — A inch blades. No. is same as No. 10 except that Ratchet Shifter moves across instead of parallel with tool. No. 15 (illustrated) with knurled thumb turn, comes with 2, 3, 4, 5, 6, and 8 inch blades. A knurled thumb-turn on No. 15 lets wobbly little screws easily with thumb and great convenience! ou start orefinger.

Good reception depends on accuracy. That’s why it pays to work with these “Yankee” Screw-drivers that drive straight, true and tight. Dealers everywhere sell “Yankee” Tools. Make your selection of those that you will need 1 in your radio work. Some of the many “Yankee” Tools are— Ratchet Hand Drills | Automatic Push Drills Ratchet Breast Drills iral Screw-drivers Ratchet Chain Drills Plain Screw-drivers Ratchet Bench Drills 11% to 30 in. blades Ratchet Tap Wrenches Helpful Tool Book Mailed Free Describes all the in- genious “Yankee” Tools

for saving time and labor. Contains numerous illustra- tions of these remarkable Write for your copy tools. today.

NorTuBros. Mra.Co., Philadelphia, U.S.A. "YANKEE" TOOLS Make BetlOv Mechanica

Hinged Angle Iron (Continued from page 97) | justable plate and the base are made of | machine steel pack-hardened to a depth of about in. All plain surfaces that must be ground should be .02 in. oversize. The hinge bolt holes should have an allowance of .03 ts in., while the surfaces of the hinge knuckles where the parts come together should have an or oo allowance of .02 hele coe tesed in. The four clamping arms are also made of machine steel. To get the hinge bolt holes parallel to the plate surfaces, it is well to rough bore them first, then clamp the piece to an angle iron that is itself bolted to the lathe carriage, and finally finish the boring with a boring bar held between the lathe centers. A milling machine will do this equally well. The tool steel hinge bolt should be slightly lapped after grinding to remove the grinding wheel roughness, and the hinge bolt hole should also be lapped until the bolt becomes a wringing fit in its hole. To avoid side play, the hinge knuckles should be lapped to an exact fit. If screw holes for straps are to be placed in the plates, they should be made before hardening. PLATE wet | CUTTER

ANGLE <—!RON

RRIAGE

Improvising a Reamer N OVERHAULING an automobile engine recently for use on a motor- boat, I found that the bearings for the crankshaft and connecting arms, which were die cast, required a great deal of scraping. To save time I improvised a reamer from a broken crankshaft of the same size as that of the engine being over- hauled. A piece of straight shaft would have done as well. Along one side of the shaft I chiseled a groove similar to a spline groove and somewhat longer than the new bearing. Then, with a blunt tool like a nut set, I hammered one edge of the groove lightly to raise the edge a trifle. After this had been filed smooth, it made a fair reamer. The shaft was clamped in a vise, the connecting arm was put on, tightened up and turned around once. It was then taken off and the shavings were cleaned out of the groove. When the reamer had cut to the bottom of the babbitt, the con- necting rod was tried on and it fitted very well. The engine bearings were trued up in the same way by using a reamer made from shafting held in place at one end by an old bearing cap, and turned with a pipe wrench. It is a good plan not to tighten the bearing cap too much, and not to turn the reamer more than once before cleaning the groove, as the chips otherwise tend to roughen the bearing. The next step was to run the crankshaft in a big lathe for a time. When the caps were taken off, I found we had a good job. —GEORGE H. MuRPHY, Wells River, Vt.

I have averaged °70007°3 fun Have Made Over $90 Profit in One Day This is the statement of Frank DePries, one of our live-wire representatives. Keeton of Mississippi made $252 on his first sale. Vickers. of Alabama made $118 in one week. Conant quit a $6,000 job to come with us. AGENTS WANTED We need more men likethese, be- cause the demand for our Super Se Fyr-Fyier is growing by leaps and bounds. Sells togarages, \ stores, factories, schools,

\ homes, hotels, auto owners. Mi »\ Approved by the Under- \ Spr writers. If you are willing to work and ambitious to make some real money, get our plan. You need no experi- ence, as we train you without cost for the work, No great capital required. Good terri- tory goingfast. Better Mm write us at once. Ford without os THE FYR- FYTER co to that big 1714 Fyr-Fyter Bldg, ad Dayton, Ohio,

HIGHEST QUALITY SIVERTONE Lowest Price VOLUME Likt ( OPERATES n dry THREE MODELS FULLY GUARANTEED Oné Price $6.00 Everywhere DeForest Tel. & Tel. Co. L QO. & T. Electric Corporation 1819 Broadway New York

The New Indestructible— Metalectric Soldering Iron Operates with the simplicity—effi- ciency—ease and comfort of a pen, on any Interchangeable tips

5" **‘worth it’ A quality instrument with a uine guarantee. Special quarter inch “ chisel” tip for fine work furnished at 25 cents extra—of your dealer or write POST ELECTRIC CO., Mfrs. (Dept. A) 30 E. 42nd St., N. Y. C.

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BETTER SHOP METHODS DEPARTMENT OF POPULAR SCIENCE MONTHLY 99

Setting a Taper Attachment with an Indicator Te cut and try method in turning a taper can be eliminated by utilizing an indicator to set the taper attachment on the lathe at the proper angle. A ‘est bar or other piece having accurate sur- faces is first placed in the lathe. The in- dicator is then mounted so that it can be moved along the piece at the angle deter- mined by the setting of the taper attach- ment. The proper readings for the indicator are next computed and the taper attach- ment is set to agree with them. Thus, if it TAPER ATTACHMENT | : 078" - ss | ARBOROR — TEST BAR __

Diagram showing how an indicator and test bar are used for setting a taper attachment for a No. 7 Morse taper is desired to cut a No. 7 Morse taper, the offset is known to be .625 in. a running foot, or .052 an inch. Since the accuracy of setting is increased by increasing the span, a 3-in. length will give a better set- ting than lin. Therefore the taper should be .078 for 3 in. The indicator is set against the test bar at a zero reading opposite the first of two points X and Y that are 3 in. apart. The indicator is then moved to the second point and the taper attachment is fast- ened so that the reading will be 78 when the indicator is against the surface of the test piece. When a difference of 78 is found in the readings taken between the two points, the taper is correct. The test piece can then be removed and the work turned without trial. Drilling in Difficult Recesses DRILL holes in narrow recesses where the ordinary ratchet cannot be used, the method illustrated may prove useful. The drill is turned by means of a

Coilspring serves as ratchet CENTER drive for INCH drill spring of 1%-in. steel wire wound tightly around a rod a trifle smaller than the drill shank and then reamed out to make a wringing fit. Under pressure the spring turns the drill, but it releases its grip on the back stroke.—J. F. D.

NERVE EXHAUSTIO How Nerve Abuse Wrecks Health by PAUL von ECTURER and Author of numerous books and treatises on Mental and Physical Energy, Respiration, Psy- chology and Nerve Culture There is but one malady more terrible than Nerve Exhaustion, and that is its kin, Insanity. Only those who have passed through a siege of Nerve Exhaustion can understand the true meaning of this statement. It is HELL; no other word can express it. At first, the victiza is afraid he will die, and as it grips him deeper he is afraid he will not die so great is his mental torture. He be- comes _ panic-stricken A and irresolute. A sick- yr > ——Eyes—Nose ening sensation of weak- BOECKMANN you that there is nothing the matter with you; that every organ is perfect. But you know there is something the matter. You feel it, and you act it. You are tired, dizzy, cannot sleep, cannot digest your food, and you have pains here and there. You are told you are “run down,” and need a rest. Your doctor may prescribe a drug—a nerve stimulant or sedative. Leave nerve tonics alone. It is like making a tired horse run by towing him behind an automobile. And don’t be deceived into believing that some magic system of physical exercise can restore the nerves. It may develop your mus- ness and_ helplessness ae cles but it does so at overcomes him. He be- —Throat the expense of the comes obsessed with the nerves, as thousands of thought of self-destruc- athletes have learned tion. ——Bronchials through bitter experi- Nerve Exhaustion is ——Chest Breathing ence. brought about through The cure of weak and nerve strain. ‘There is py-——Heart deranged nerves must no other cause. Men iN have for its basis an strain their nerves ) understanding of how through mental con- the nerves are affected centration and business ae by various abuses and worries; often, too, Y strains. It demands an thtough excesses and fg understanding of cer- : _ ; ( tomach ‘ , “ vices. Women. strain : , tain simple laws in their nerves < —_ mainly through their emotions, especially those involved in their domestic affairs. Indeed, we are in the midst of nerve strain everywhere due to “the mile a minute life we are leading. And no man or woman is so strong as to be,immune to this strain. Nerve Exhaustion is not a malady that comes suddenly, yet its symp- toms are unmistakable. It does not manifest itself, as many think, in twitching and trembling hands. The majority of sufferers from nerves seem strong and healthy, and may have not a tremor in their body, yet inwardly their nerves are in a tur- moil and are undermining the entire bodily organism. The symptoms of Nerve Exhaustion vary according to individual characteristics, but the development is usually as follows: First Stage: Lack of energy and endurance; that “tired feeling.” Second Stage: Nervousness; rest- lessness; sleeplessness; irritability; decline in sex force; loss of hair; nervous indigestion; sour stomach; gas in bowels; constipation; ir- regular heart; poor memory; lack of mental endurance; dizziness; headache; backache; neuritis, rheumatism, and other pains. Third Stage: Serious mental disturbances; fear, undue worry; melancholia; dangerous organic disturbances; suicidal ,tendencies; and in ex- treme cases, insanity. If only a few of the symptoms mentioned apply to you, especially those indicating mental turmoil, you may be sure that your nerves are at fault—that you have exhausted your Nerve Force. Perhaps you have chased from doctor to doctor seeking relief for a mysterious “some- thing the matter with you.” Each doctor tells

) SNS ——lIntestines —— Bladder — Pelvic Organs Showing how Every Vital Organ is governed by the Nervous System, and how the Solar Plexus, commonly known as the Abdominal brain, is the Great Central Station for the distribution of Nerve Force. —SOLAR PLEXUS mental and physical hygiene, mental con- a trol, relaxation, and 5 how to develop im- munity to the many ——Kidneys strains of everyday life. -| : Through the applica- Colon tion of this knowledge the most advanced case of Nerve Exhaustion can be corrected. I have made a life study of the mental and phys- The Sympathetic Nervous System jcal_ characteristics of nervous people, havin treated more cases 0 “Nerves” during the past 25 years than any other man in the world (over 100,000 cases). The results of this vast’ experience is embodied in a 64 page book, entitled “Nerve Force,” a book that is essentially intended to teach how to care for the nerves and how to apply simple methods for their restoration. It includes important information on the application of deep breathing as a remedial agent. The cost of the book is only 25 cents, coin or stamps. Address me—Paul von Boeckmann, Studio 162, 110 West 40 St., New York City. This book will enable you to diagnose your troubles un- derstandingly. The facts presented wil! prove a revela- tion to you, and the advice will be of incalculable value, whether you have had trouble with your nerves or not. Your nerves are the most precious possession you have. Through them you experience all that makes life worth living, for to be dull-nerved means to be dull-brained, insensible to the higher phases of life—love, moral cour- age, ambition, and temperament. The finer your brain is the finer and more delicate is your nervous system. and the more imperative it is that you care for your nerves. “Nerve Force” is not an advertisement of any treatment I have to offer. This is proved by the fact that large corporations have bought and are buying this book from me by the hundreds and thousands for circulation among their employees—Efficiency. Physicians recommend the book to their patients—Health. Ministers recommend it from the pulpit—Nerve Control, Happiness. Never before has so great a mass of valuable 1 meme been presented in so few words It will enable you to under- stand your Nerves, your Mind, your Emotions, and your Body. Over a million copies have been sold during the past fifteen years,

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100 Millers Falls } Radio Hand

An excellent tool for radio fans and general work around the house Hit: the fun of being a radio fan is in making your own set. And there's a lot of fun in fixing things yourself around the house. Here’s a new Millers Falls tool that’s made just right to give you the greatest satisfaction in such work,and youcan buyit ata price that will add to its satisfaction. It’s called the radio hand drill— No.85. Takes round shank drills up to 44", big enough to handle all radio jobs. See it at your hardware dealer’s— if he doesn’t carryit write us and we'lltellyouhowyoucangetone. MILLERS FALLS COMPANY Millers Falls, Mass. Manufacturers of Carpenters’ Tools, Hack Saws and Automobile Tools

MILLERS FALLS TOOLS

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

Non-Tipping Bob Built for Safety By Henry S. Laraby LD as is the 6) sport of coast- ing, few bob-sleds are built with proper regard to safety. Often the sleds are bolted directly to blocks, so that they cannot rock when going over the snow ruts and bumps, and even when rockers are provided, there is no round block like a fifth wheel to give adequate bearing to the front sled in turning corners. Indeed, the bearing is usually less on the turns than at any other time and since that is just when the maximum support is needed, many an upset happens on curves. These shortcom- ings are avoided in the bob-sled design illustrated. Both sleds are mounted on rockers and the upper rocker of the front sled is bolted to a round oak block that bears directly against the under side of the main plank. The bob therefore rides all the bumps easily

WIG ----7 BOX FOR BATTERIES pr. ad

pulley eyebolts are shown on the cross bar. For rope steering a bolt is substituted for the wheel shaft. Note that the lower end of the wheel shaft in this design is split and bent to serve as the upper rock- ers of the front sled. The runners are 1 or % in. (according to the thickness of the sled sides) half oval steel, screwed on. They are better, to my mind, than spring runners, which are bound to come off in time, or flat ones, which sometimes side slip in turning. The cross bar is unusually heavy. This is so that it will act as a bumper in a collision and very likely save the legs of the rider from getting hurt. The hood holds the batteries for the two auto lights and also has room for lunches for’ the coasting party. I might add a word of caution in regard to operating CARRIAGE. BOLTS-%4" YonCHAMFER

~¥ EYE BOLT WHEEL ‘“s SPLIT oom ee % IRON; ae at

OETAIL OF DASH DETAIL OF DETAIL OF AND BOX FRAME BLOCK AND BLOCK AND TOP ROCKER TOP ROCKER No.2 NO.I

a OAK -~ z rae bei, ip IRONS 10 3+ 4 t.. OAK

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UNDER SIDE UX 12"X13-O7 OAK a “4 : t is A Tag ® il : “ BOLTS \ # CARRIAGE it Y BOLTS

1 24 aby DETAIL OF DETAIL OF OETAIL OF LOWER BLOCKS CROSSPIECE CROSSPIECES_ AND ROCKERS A BANDC NOS.1&2 Side view of the bob, the under side of the main plank, and details of the dash, blocks, and rockers, and cross pieces. and takes the curves without danger of upsetting. This flexibility is also a factor in making the bob unusually speedy. The main plank is 1 or % by 12 in. by 13 ft. The dimensions purposely are kept down in size because the writer’s experi- ence in building larger bobs, one nearly 20 ft. long, has been that they are too heavy to pull uphill. The bob is all oak except the dash and the hood. This makes the construction heavy, but the bob is no one-man pull anyway. Built in this fashion, the sled will stand up under hard usage for years. The main dimensions and method of construction are made clear in the details. While my preference is for an auto wheel for steering, the bob may be steered with ropes and pulleys in the usual way. The The sled can be steered either with an auto wheel, as shown, or in the usual way with ropes the bob. Either pick a steersman who knows his job or stick to low hills until experience is gained in handling the sled; If a rope is used, be sure it will stand the gaff. I well recall once trying out a bob built along identical lines, only larger. About 18 of us were going down the hill when a rope broke and we hit a post. We went sliding forward over the dash, over a fence, and down over a 20-ft. drop into a creek. Every one hit his head on the top rail of the fence and teeth were lost all around. On another occasion we iced the hill with a hose and as a result went through the front porch of a house. So coasting, while one of the most thrilling of winter sports, is not to be approached with any display of foolhardiness.

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HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Tin Tobacco Box Used for Novel Perpetual Calendar PERPETUAL calendar, good not only for 1924, but for any year, can be made at practically no cost. After cutting down an empty tobacco box of the oval pocket kind to 2% in. high, make a 114 by 2 in. opening in one side. Next make two wooden rollers, as HEADLESS NAIL PIECE OF CELLULOID CUT- DOWN TOBACCO BOX SLOT FOR SCREWDRIVER How the calendar is made and assembled shown, with headless nails driven in the ends to engage holes punched in the top and bottom of the box. Prepare a strip of paper a little nar- rower than the height of the box and long enough to pass around the two rollers, allowing a lap for pasting. Divide and number as indicated, assemble the whole, and gild or paint the case. Place the figure 1 under the day of the week on which the month begins. Complete List of Blueprints A one of the blueprints listed below can be obtained from POPULAR SCIENCE MONTHLY for 25 cents. The Editor will be glad to pro- vide, upon request, information rela- tive to tools, material, or equipment. Blueprint Service Dept. Popular Science Monthly 225 West 39th St., New York. GENTLEMEN: Send me the blueprint, or blueprints, I have checked below, for which I in- CORO, 6 2 0s cents in stamps or coin: No. Title Price ST . BR OI s a 5c 00 6095 oo esc 25c 2. Smoking Cabinet............. 25c 3. Book Trough End Table....... 25c 5. Kitchen Capinet............0. 25c 6. Two-Stage Radio Receiving Set. 25c 8. Shaving Cabinet.........ccees 25c 9. Arbor with Gate and Seats... ..25c AO, Beep Ce PIN 5 65:06:65.9 wes sb 0 08 25c 11. Bench and Tilt-Top Table..... 25c 12. Electric Washing Machine..... 25c BS RR ies ln eee ar 25c 14. Toy Train, Horse, and House.. .25c 15. Home Workshop Bench....... 25¢ 16. Inlaid Radio Cabinet.......... 25c 17. Cedar and Mahogany Chest... .25c 18. Telephone Table and Stool... . .25c 19. peng mag lle “Ee. See 25c¢ VR ge Cg 25c 21 eilocioy Wat Writing Desk........ 25c 22. Girl’s Cabinet and Desk....... 25c yk Ry eer 25c 24. Copteler Waite. bck oihsss sos s ee 25c 25. Sailing Outfit for Canoe........ 25¢ 26. Baby’s Crib and Play Pen... ..25c 27. Kitchen Cabinet Work Table. . 25c 28. Pullman Play Table........... 25c 29. Toy Tea Cart, Garage, etc... ..25c 30. Tool Cabinet, ‘Bench Hook, ete. 25¢ ooooooooOoooOooOooooooooOoOoOo000o oto “Built First to Last * Make it a Coto Compact Radio Christmas OU have plenty of time to build a Coto Compact set before the holiday. Get together with your local deal- er. He will advise you and help you get real results. And give presents of Coto Radio Apparatus this Christ- mas. Always most acceptable to radio enthusiasts of all SA LAL ages. In a class alone for combined compactness and reliability. Coto Compact Moulded Variocoupler Compact for neat, portable sets. Size only 3144 x 3 x 33 inches. Efficiently covers range of 200 to 600 meters. Eight taps for use with primary condenser. Pigtail connec- tions to rotor. Base or pene $ 5: 50 mount. Type 9000. Reliable Dealers Always Recommend Coto Quality Dealers value the trade of those who insist on Coto Quality. If your dealer fails you, send us his name and we will see that you are supplied. Pacific Coast Branch: Northwestern Branch: Minneapolis, Minn. Southeastern Branch: tlanta, Ga. COTO-COIL CO. 87 Willard Avenue, Providence, R. I. 329 Union League Bldg., Los Angeles, Cal. Geo. F. Darling, 705 Plymouth Bldg., Cc. P: seeds Atlanta Trust Co. Bldg., New Coto Compact Moulded Variometer Size only 34% x1%x3%. In moulded bakelite. Stator is hon- eycomb wound. Pigtail con- nections to rotor. Range 200 to 600 meters. Base or panel $5 mount. Type 8000....... New Coto Compact Air Condenser with Vernier Only 2 7/8 inches square. Ro- tor plates soldered to shaft. ee ar soldered to supports -001 Mid. > $5 Mfd. 6 Coto Special Audio Frequency Transformer Turn ratio of 3 to 1. Coto —_ a but made to at a popular price. EMG SaeGe sn cccccees $2. 50 The Original Honeycomb Wound Inductance Units Popular low priced favorites of the amateur and experimenter. Permit the economical building of an all wave set. Sold mounted or unmounted. Coto Tapped Radio Frequency Transformer Efficiently covers the whole broadcasting range because it is tapped. a switch control for one or st Type 5000 Sonn —— ages. $7. 50 PIA PED ITU 101 sae s ee nee ee ere teen nee Ore ne ENTNE TNT Tew Nene ee ee ore pic hss Oy Ee

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102 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

Radio Officer N. C. Kumler, graduate of the Radio Insti- tute of America, awarded a gold medal by the city of Los Angeles, and $500 by the Radio Corporation of Amer- ica for heroic services at the sinking of the S.S. Honolulu. Wanted— Trained RADIO Men The story of radio rescue when the Honolulu sank is but one of hundreds in the lives of far-traveling radio operators. It has al- ways been a life of fasci- nation—and today offers a big future. Over 6,000 operators have already graduated from our school. And many more trained men are needed. Study at home in your spare time. You may know nothing of radio today. But ina few months study, you can earn your U. S. Govern- ment operator’s license. The Radio Corporation of America, which places more operators than any other organization in the world, prefers our grad- uates, for their thorough training. Many among them have become the biggest meninradiotoday.

Advanced Radio Course Great popular demand bythe advanced student, experienced amateur and wire- less operator has led to the opening of an ADVANCED HOME STUDY RADIO COURSE, specializing in C. W., I. C. W., telephone and radio measurements. Investigate!

Radio Institute of America (Formerly Marconi Institute) Established 1909 328 Broadway, New York City Indicate byacross X the course you are interestedin: Radio Institute of America, 3 328 Broadway, New York. 5 Please send me full information about ‘ radio opportunities today, and your H COMPLETE RADIO COURSE 0 H ADVANCED RADIO COURSE 0 SOOa seme ceeseseseaseseseas i]

EL. cs sn dE kisi Wes CAsBb eS Wh cbbs ¥06ss se secewe Home and Home Workshop Chemistry SSS Sy Se ree columns, and a wealth of other material will complete the department. Child’s Wooden Savings Bank Has Trick Drawer By Kenneth R. LaVoy (Oren take delight in depositing money in this unique wooden bank because of the ingenious construction of the drawer, which allows coins to be put in but not removed. The bank, if care- fully made and well finished, is an orna- ment on a shelf or bureau. A silk tassel A coin placed in the opening in the drawer falls to the bottom of the box when the drawer is pushed in hung from a small cup hook makes a dec- orative drawer pull. Nails are used throughout to hold the parts together with the exception of the bottom piece, which is fastened with screws. This permits the removal of the coins, when the bank is full, without destroying it. The nails should be set in and the holes plugged with putty. Two coats of enamel give a satisfactory finish,

| On the February Schedule OR the woodworker there will be details of an especially attractive Priscilla sewing cabinet as well as a straight-legged cabinet of modern de- sign. Other articles will tell how to make inlaid serving trays from cigar- box wood, a neat cabinet for stains and chemicals, and a plant stand with or- namental trellis. Roland B. Cutler, specialist in the construction of toys that boys like to build, will tell how to make a ski-sled. Dr. E. Bade will give unusual designs for decorative weather vanes. R. J. Stephens, who wrote the re- markable home-building story that ap- peared in the January, 1923, Popular Science Monthly, writes on “How to Save Money in Building a Small Home.” Joe V. Romig takes for his topic, “Getting the Most Out of Your Tools.” Auto kinks, suggestions for metal workers, radio stories, the Shipshape

EarnBigMoney jE gem Learn the 2 NA —Own Automobile <1 ft f = yo puss 70 pee ol cars! Engines,

electrical systems, batteries, ~-. tires, etc. There are not nearly =a enough trained men to do this work. Grad- uates of this School (all over the world) are successful, making money in this business, either in good jobs or shops of their own. Age, edu- cation, or experience make no difference. You can be successful too, if you will get M.S. A.S, practical training now. UNLIMITED OPPORTUNITIES FOR TRAINED MEN Study autos, trucks, engines, auto electricity, tractors. Learn on best equipment, all in good condition, up-to-date; expert instructors to teach you, a thorough complete course that slights nothing. Plenty of time in every department to learn it right. COME TO DETROIT THE AUTO CENTER Here you have wonderful advantages. Visit the at plants, Ford, Cadillac, Packard, Lincoln, odge, Hupp, Hudson, Studebaker, many others. These great companies also endorse this school because they know our course trains you right, Get factory endorsed training at Detroit, the Auto Center. Be Successful! Write today for 100-page catalog describing school, Detroit, opportunities. Address A. G. Zeller, President. Write today. MICHIGAN STATE AUTOMOBILE SCHOOL 581 Auto Building Detroit, Michigan Le Teach COMMERCIAL

Meyer Both Company, the largest Commercial rganization inthe . World offers you an unusual opportunity for practical training, based upon twenty-three years of success. This nationally known organization each year produces and sells to advertisers over 15,000 commercial drawings. Meyer Both in- struction is the difference between successful fact and experimental theory This well paid profession equally open to men and women. Home study instruction. Get Facts Before You Enroll in Any School Ask the Advertising Manager of the leading news- papers in your city, anywhere in the Uni States, Canada, England or Australia about the Meyer Both Company—let them tell youabout us. Write for our illustrated book telling about the success of our students—for one-half the cost of mailing—four cents in stamps. MEYER BOTH COMPANY Department of Art Instruction Michigan Ave. at 20th St., Dept. 35, CHICAGO, ILL. Note—To Art and Engraving Firms: Secure practi- cal artists among our graduates. Write us.

It Will Pay You to Own a MONARCH Junior Lathe Hundreds of things, of metal or wood, for the shop, auto and home can be made with a MONARCH Junior Lathe. This sturdy, small engine lathe, guaranteed to do work with 1/1000 of an inch accuracy, was ‘especially designed for inventors, experimenters and small 8hop owners. It is easy to learn to operate—even beginners — am 1 . quipped with auto- matic safety devices. $245 9" lathe—2 4% ft. bed—with bench legs SEND for Free catalog of MONARCH lathes which are built up to 30” swing THE MONARCH MACHINE TOOL CO. 401 Oak Street SIDNEY, Ohio

Se a

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Built-In Tool Rack Is Useful Addition to Roadster 7 cover of the rear compartment on a roadster is an excellent place for installing a tool rack. Two or three pieces of wood are screwed to the frame under the lid and are fitted with metal strap loops. A leather strap is fastened at one \Y RS {I iy When tightened and buckled, the straps hold each tool firmly in its own place in the cover cf the rear compartment end of each wooden strip and a buckle for tightening it is placed at the other end. Small tools that are not readily held can be fixed by cutting a recess into the wood with a gouge or chisel. All rattling and damaging of tools is thus avoided, and tools are always conveniently at hand when needed. Holder for Baby’s Bottles “Pere for baby’s bottles is an exact- ing task that is lightened by the use of the simple stand illustrated. The top and bottom are of 4-in. wood nailed or QW POSTS - A/,"xI" x1" —= This labor-saving container for glass sterilizers is made of two thin pieces of wood and four small posts screwed to four supports. Eight holes are drilled in the top piece } in. larger in diameter than the bottles. The filled bottles are set in the holder, covered with a cloth and placed in an icebox compart- ment.—FRANK N. COAKLEY, Buffalo,N.Y. To cuT a stovepipe, mark off the length to be cut and scribe a line around the entire pipe. File a small hole with a three-cornered file on the line. just scribed and insert the blade of a can opener in the hole. Then cut the pipe like an ordinary tincan. This will leave edges that are cleaner cut than if tin snips were _used.—EDWARD W. PRASEK, Cleveland, O. Charges Radio and Auto Batteries at Home Over Night = For a Nickel! For a friend who owns a radio set or automobile, what could be more appropriate than a gift which would eliminate the inconvenience and expense of taking his battery to a service station every time it requires recharging? The Othe World’ ; J ‘She World's Host Popular is such a gift, appropriately dressed up in a beautiful Christmas package, too. It charges any AUTO, REBIO or ‘‘B’’ storage battery in the si = quickest and most’ efficient manner pos- sible. Connects to any lamp socket—operates silently—requires no watching. Fully automatic in operation—absolutely safe. HOMCHARGER’S TEN POINTS OF SUPERIORITY 1. Simple—Only one moving and wearing part, 6. Fool-Proof—Can be operated by anyone. replaceable after thousands of hours use for Attach to lamp socket and connect: battery $1 Will last a lifetime. either way it will alwayscharge. High-grade 2. Efficient—Uses less than one-half the current ammeter eliminates guess work. of any bulb or liquid type rectifier. Willcharge 9. Safe—Nodanger of shock or fire. Tested and any radio or automobile battery for a nickel. approved by Fire Insurance Underwriters 3 ick—its high charging rate of 7 amperes pee ont, pests dhe ring charge—will not eliminates long waiting for battery to become 8 Beautif ass peeetayl i 'd Gold Fi charged. Will charge any “‘A™ or “B™ battery bas jogany an: inish. over night, or three times as fast as a 2-ampere 9. Unqualifiedly Guaranteed. machine. 10. ey ee at $18.50 com- 4. Clean—No expensive bulbs to break or acids ee Ween anada). No extras to buy. Id by all dealers. FREE BROADCASTING LIST. Ask your dealer or write direct for Free to spill or replace. No acid fumes. Charges without muss, fuss or bother. 5. Dependable—Tungsten contacts insure con- Hegerase List of Broadcast Stations, tinuous operation—prevent sticking and stop- and Cir Describing the Gold Hom- ping. charger. DEALERS! JOBBERS! to be “‘best sellers’’ GOLD SEAL HOMCHARGERS in their attractive Xmas packages are dising p then prepare to get your to the e pneny f trade. Write for our elaborate m share of this big ‘‘Homcharger Xmas business’’. Insist on the GOLD SEAL ACCEPT NO SUBSTITUTE. Like all gond products, the HOMe CHARGER has been widely imitated. No other charger is just as ood. INSIST on seeing our registered trade-mark, the ‘GOLD SEAL,” on nameplete and carton before purchasing. %eAutomaticElectrical DevicesCo., 131 West Third St., Cincinnati, 0. eo Largest Manufacturers of Vibrating Rectifiers in the World:~ SP ma WANTED! RAILW Men and Women—17 to 45 Years $1600 to $2600 a Year Common Education Sufficient—Travel— see the country no lay-offs—lifetime Job Holidays with pay Write today for free list of positions obtainable You can earn $15 to $50 a week show cards in yorr own home.—No can A a ow pote oem easy and quickly at by our new lock A Artistic ability not y —We teach you how, and supply work—Distance no Witton Mm o) booklet free. N METHODS LIMITED— DEPT, 3-A 64 East Richmond, Toronto, Canada. and information how to get a position. United Business Tr. Ass’n., 807 Dinan Bidg., Detroit, Mich, na cesieacneneinndes Sadia sssnnsnae ana sitet aia ini atcha j “4

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Scientific Barbering “2s. Near Home / HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 0 Colleges with 33 branches, located in all principal cities of the United States, teaches the highest degree of Barber Service—in a few weeks—places graduates in positions Graduates 7 paying up to $75 a week or enables men There 1s to make up to a thousand dollars a month in his own shop. a Next to, the Surgeon, there is no one in , whom the public place themselves with so Moler complete confidence as they do with the modern Barber—they want Moler Service and will pay School for it. Scientific Barbering means Moler Methods. Say “My shop has doubled its receipts since oming one of the Moler Chain Shops. The business- like way in which your Near Our short practical course—saves 2 years of ap- advertising educates Y prenticeship—teaches you Bobbing and Mar- my customers to this ou celling—gives you short cuts to big pay, puts you in line for one of the Moler Shops—service of which is being advertised nationally. Moler methods—Moler Service mean success for you from the start and you can learn them right near home. . To the man without a profession, this thoroughly practical short course gives youa new lease on life, travel, sure work; to the underpaid man it is a godsend. This is light, clean, inside work and It Pays. Booklet C, which is mailed Free— will tell you how the training puts you into the best shops, or if you will, helps you get started in your own business by equipping your shop oneasy terms. Infact Moler takes you as you are—makes your life work easier, better paying—and more gratifying. Write Today—Nearest Branch service has worked won- ders. The protection you give me in this exclusive territory insures my future. “I am proud to say I am a Moler Post Graduate Shop Owner.” Another Post Graduate says— “My position in the Moler Post Graduate Chain Shop is entirely satis- factory. I had never supposed a Barber Shop could be conducted on so high a standard in service and morale. Women and children, also, do not hesitate to patronize us for their Bobbing and Marcels. “This Post Graduate Service is surely a revela- tion in Barbering.” Another states— “I can now travel and see the world and be sure of a job ina Moler = yy 157 Third Ave. , New York, N.Y. 23 N. Forsyth St. Atlanta, Ga. Post Graduate Shop—anywhere.” 195. Wells St. Chicago, Ill. 80 N. 2nd St. Memphis, Tenn. — ee ee ee eee eee ee ee ee ee my ey ees = “ “4 oa ae _ 910 Main St. Dallas, Texas Moler System of Colleges i ain St. Kansas City, Mo. 71? Franklin Ave. Houston, Texas t = od a Peis soy 727 W. Commerce St., San Antonio, Texas --""" WRITE NEAREST BRANCH) "7777 | 1045 Cass Ave. Detroit, Mich, 429 ©: Fifth St Las Angeles, Calif Please send Pithout . obligation your Free i 1229 17th St. Denver, Cole. 159 Fourth St. San Francisco, Calif. . a 10S. 14th St. Omaha, Neb, 218 J St Sacramento, Calif, | I SI3E. Water St. Milwaukee, Wis, 955 G. St. ___ Fresno, Calif. 1 1005 Canal St. New Orleans, La. 114 Regent St. Salt Lake City, Utah FOR EASY MOUNTING FRAMINGHAM DE LUXE PARTS | Ask Your Dealer | 0 Monthly Brings You Big ~U BATTERY CHARGING PROFITS wn a mouey-making battery charging bus- Dayerent brings you 1S hour charsinn en ngs you ur Cc! im outfit. Easy $20 monthly terms let sour pay balance_ with nice surplus besides. Thi rial on money week at Home, In Your Spare Time. Method. No Canvassing. per: Unnecessary. Teach You How, Guarantee you Steady Work and pay and cash no matter where you live. rite today for ree sample lesson and Illustrated Booklet. UNITED SHOW OARD STUDIOS, 818 Dinan Bidg., Detroit. Mich. You can make 15 to 50 Dollars a Easily I ed b: New Simple asily — y our we Tap Wrench Holds Small | Washers for Reaming | _ it is necessary to enlarge a hole in a small washer, the job is easily done, if a lathe is at hand, by chucking the washer and running a boring tool through. Lacking a lathe, however, the job is of the ‘“‘mean”’ variety, because 2G) A convenient way to hold washers firmly ‘without damaging them it is difficult to hold the washer while drilling or reaming it. A simple expedient is to grip the washer in a tap wrench, as shown. This does not disfigure the face of the washer, which often is important, and any slight marks on the edges can readily be re- moved as a rule. If appearances are especially important, the edges can be protected by strips of softer metal, fiber, or cardboard.—H. G. To Keep Glue Can or Bottle Tightly Closed with Clamp T° KEEP the liquid glue can or bottle properly sealed is always a problem. If the cap or cork is closed tightly, it sticks and is difficult to remove; if it is put on loosely, the glue gets hard. r Recently the woop Writer hit upon J the method il- lustrated and finds that it works very well. Simply use a flat piece of wood and a cheap clamp. Place the wood over the open- ing of the can or bottle and clamp it on. It makes an abso- lutely tight joint, is easily removed, and if too much glue adheres to the wood, it is a simple matter to find a new piece that will do. The container may be put away in a drawer or box on its side, or it may even be hung by the clamp on a nail. Even if it is upside down, there is no danger of leakage.—N. G. NEAR. BOTTLE OF GLUE A tight stopper, easily removed Cracks in Castings PREVENT a crack in a casting from extending, the usual practice is to drill a hole at each end, but this frequently fails because the holes were not drilled in-the proper place. To de- termine exactly how long a crack is, cover the surface with a mixture of equal parts of kerosene and oil. Allow it to stand for a time, wipe the surface clean, and brush on the whitewashing mixture used when laying off lines. The crack will show up clearly.

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is ccteitici sy AE LTTE

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 105

—— FREE book on DEAF- giving you full particulars and WILSON EAR _DRUM CO.., Incorporated 471 Inter-Southern Bldg. Louisville, Ky.

Easy Payments at- ead if desired. Conn @ has been recognized’ su- reme for halfa century & the world's greatest artists. Write for details, wwe instrument. Cc. G. CONN Ltd. 122 Conn Building Elkhart, Indiana

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wr Pa ’ SMALE SWE ES . ts + oe oa I bs mer Cy ns oh re) Dang . porene Ss anid eae . " ‘a oe. o . para e f eee ae cee amen Se wy Otis fo ie ESTER TIE Te iF ele eT DR OE Coma ATK Atkins “‘Non-Breakable”’ Hack Saw Cut Faster— Do Not Break UT an Atkins Non-Brgakable Blade P: your hack saw franpe, and you'll feel the difference at nce. It will saw the toughest metal faster and easier than ordinary blades, hol its cutting edge longer, and will not bre§k. There’s a reason. Thesg blades are made of selected steel, and ge hardened and tempered by an exclusfe gas-and- oil process, which gives.a hard,{een cutting edge and a tough, flexible Edy to the blade. You can eliminate losses of time and money due to breakage of briitle blades by using Atkins Non-Breakable Hack Saw Blades. Prove it for yourself. Send ten cents and tell us what metal you want to cut, and we’ll send you a sample 8 or 10 inch blade that will out-cut and out-last any other blade. Blades for Hand Use Get This FREE Hack Saw Chart It will save you time, money and labor, and insure better work. Shows the right hack saw blade to use for each metal- cutting job—in hand frames or power machines. If you buy or use hack saws, you need it. Just write your name, address and dealer’s name on the margin of this page, and mail today. Saws for Every Use When you need a hand saw, circular saw, band saw, pruning saw, metal-cutting machine, or any saw for cutting wood or metal—there’s an Atkins product that will save time, money and labor. Write for free booklets on the saws you need. E. C. ATKINS & Co. Inc. Dept. D-20, Indianapolis, Ind. Makers of Silver Steel Saws & Tools Cheap Balsam Microscope Reveals Hidden Wonders By William J. Edmonds ANY wonders of the invisible world are revealed by the quickly and cheaply made balsam microscope illus- trated. The handle is a piece of broom- stick about 1 in. in diameter and 4 in. long. A length of \-in. wire is inserted near one end so as to project about 3 in., as shown, and a saw slot is cut in the end of the handle to carry the lens unit. To make this unit requires first a piece of glass, 1144 by 2 in., as free from flaws and bubbles as possible. The edges must be smoothed and the surfaces carefully cleaned. On one side a piece of black paper Handle, lens unit, and sliding stage the paper a pinhole is securely fast- ened with glue. In the center of is made. On the other side of the glass, opposite the pinhole, the lens proper is formed of Canada or other crystal-clear balsam. The balsam is placed on another piece of glass and boiled. While it is liquid, all bubbles are broken by means of a pin point. A drop of this clear liquid balsam is then placed on the lens slide directly op- posite the pinhole in the black paper. It should be as nearly circular as possible. The slide is then laid across an open box to protect it from dust and to prevent any injury to the lens while it is harden- ing. It is advisable to make several lens units and test them; one is almost certain to be distinctly better than the others, and it should be retained. The stage is a glass strip 1 by 2 in., backed up by a piece of thin wood with a 1-in. hole bored in it center of the glass, to come opposite the the two being held together by means of two rubber bands. The wood has a lower semicircular ear with a -in. hole to slip over the 3-in. long wire slide. The surface of the wood that comes in contact with the glass strip is painted a dull black. Drawing ink may be used for coloring it. The units are then assembled, the drop of bal- sam being on the side of the lens unit facing the stage. The ob- ject to be ex- amined is placed on the stage and Bottom view, showing hole through stage focusing is accomplished by sliding it back and forth on the wire rod. With this microscope a drop of water will seem like a small world, and even the simplest specimens will be found of fasci- nating complexity. To DO concreting in cold weather, heat must be provided. For temperatures not lower than 22 degrees, 11% lbs. of salt to 18 gals. of water can be used as a mix- ing fluid. Otherwise the materials and the mixing water should be heated with fire or steam. HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY INS METAL CUTTING Write for this BULLETIN “"16”’ x 6’ Quick Change Gear $466 16’’ x 6’ Standard Change Gear $406 “LATHE WORK SIMPLIFIED” con- tains 52 illustrations of up-to-date lathe operations that every mechanic should study. Over 30,000 users attest to the performance, accuracy and durability of SOU7H BEND LATHES. is Size Standard 9x 3' Lathe $211.00 11° x 4' Lathe 248.00 . 13° x 5’ Lathe 304.00 15°x 6' Lathe 376.00 16° x §8' Lathe 438.00 18° x 10’ Lathe 656.00 Write today for the Bulletin. Catalog No. 83 will also be sent you without obligation. SOUTH BEND / LATHE WORKS 575 E. Madison St. Js SOUTH BEND [ATHES —T + To Your Knowledge Your Earning Power There’s a better job just ahead of you— if you fit yourself for it. The more you know, the more you can earn. Add to your knowledge and you will surely multiply your earning power. Train yourself to be worth more money— then GET IT. We can help you to earn more money —perhaps double your present salary. Check, on the coupon below, the occu- pation you think you would like, fill in your name and address. We'll tell you where you belong and how to get there through an American School Course. The lessons are simple, you study right at home in your spare time, the results are sure. The cost is low, terms easy, satisfaction guaranteed. Fill out coupon mow. Learn how to make ee big money in the line of work you should doing. Fullinformation free. American School Dept. GI75A Drexel Ave. & 58th St., Chi © A.S. 1923 American School, Dept.CA75A Drexel Ave. & 58th St., Chicago checked. Law Send me full information on the ... Archi Practice T

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specially pre

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 107

At the dealer’s Counter Try the ‘“‘magnet test’’ with the Radio Head Set Unscrew the cap on the ear piece. Place the thin circular diaphragm on the counter. Hold the ear piece above it and see how powerful the magnets are in picking up the diaphragm. Try the same test with any other head- set and notice the difference. Power- ful magnets in a Radio Headset give strong, clear signals. Sold by dealers everywhere, Stromberg-Carlson Telephone Mfg. Co., Rochester, N. Ye

‘s‘Music Lessons UNDER MASTER IER io? At Home

Let a Master Teach You Music Learn to play for Pleasure or Profit without leaving home. Our simplified and complete courses are for home study. Celebrating 20th Anniversary with Special Tuition Rates Be pe rabepr of the first to receive the Annive GSe. Not a ethod but one tried and endorsed by wski and others great authorities as well as by thousands = iy — PIANO—CORNET—VIOLIN—HARMO) GUITAR—B ANJO— MANDOLIN. VOICE, ” x ab ste SCHOOL MUSIC Sil s abet reed ts fees bock™ Weits SRI strane = one — details of thelessonsand our Anniversa: Offer ich meansa cash credit on your tuition. Careful train ing ing by re — 2 grading examinations aioe ae the Ccoa. ion for each individual 1, _See for yourself ee oF have done, You can LS ceecer the eoanepenelan,

University Extension Conserva: 854 Siegel-Myers Bldg., Chicago, III.

Miniature Kitchen Cabinet Is Novel Toy for Little Girls By Herbert A, Mincher SMALL kitchen cabinet, standing about as high as a table, is a toy that provides perpetual entertainment for small girls. To build one requires only a hammer, saw, square, chisel, plane, screwdriver and miter box. The materials need- ed are: 1 piece % by 1% in. by 10 ft. (plowed 4 by 4 in.) for bottom section end frames 1 piece % by 1 in. by 12 ft. (plowed \y% by \ in.) for door frames 1 piece 4% by1% in. by 11 ft. for top and, bottom front frames 1 piece % by 6 in. by 4 ft. for top section ends 1 piece % by 534 in. by S ft. for shelves 1 piece % by 14% in. by 1ft. 9 in, for table top 1 piece 4% by 7X by 1 ft. 9 in. for top 1 piece % by 13 in. by 1 ft. 7 in. for bottom 1 piece %-in, quarter-round molding for bracing back and bottom 1 piece wallboard, plywood, or plaster board 3 ft. by 3 ft. for back, door panels, and end panels 2 pieces 64% by 914 in. selected sheet glass 4 door catches 8 1-in, narrow butt hinges

The finished cabinet with toy dishes The cabinet is made in two sections, the upper part being fastened to the lower with screws put in on an angle under the table top. The writer first cut the legs and the rails for the ends, which are made of 34 by " 1 FRAMES \ y/) MN A

The chief dimensions of the cabinet, which is made in two sections fastened together with screws, the other parts being nailed 11% in. material plowed on one edge 14 by 4 in. for the plaster board panel. The groove should be made to suit the thick- ness of the paneling used, which may be wallboard, plywood, or solid stock. These pieces are nailed together and reinforced (Continued on page 108)

Thackeray liked his pipe and said so

—a great physical aid in conversation

William Makepeace Thackeray must have felt more than friendly towards smoking, for he wrote:. “Honest men, with pipes or cigars in their mouths, have great physical advantages in conversation. ... The pipe draws wisdom from the lips of the philosopher and shuts up the mouths of the foolish.” Often you see two men sitting comfort- ably smoking their pipes in silence. They have no need for talk. The quiet puffing at their pipes is sufficient bond between them. Or you will see other men sit for hours in friendly discussion with pipes going all the time. Here the pipe seems to draw them out. And yet, for all its sociability, the pipe is a great solace to the man who finds himself all alone. As a real companion you have to travel far and wide to find anything to beat the pipe. You have any number of brands to choose from. No matter how hard you are to please, you can surely find the tobacco that suits your — tempera- ment. -<¢ If you haven’t tried Plan i there is 4 fairly good chance that it is the tobacco you have always been hoping to find. Edgeworth has made thousands of friends in all parts of the country, and each year it makes more and more new friends. If you will send your name and address, Larus & Brother Com- pany will be glad to send you free samples both of Edgeworth Plug slice and Ready- Rubbed. A few pipefuls should suggest to you whether or not you care to go further along the Edgeworth trail.

For the free samples, address Larus & Brother Company, 59 South 21st Street, Richmond, Va. If you will also include the name and address of your regular tobacco dealer, your courtesy will be ap- preciated. To Retail Tobacco Merchants: If your jobber cannot supply you with Edgeworth Larus & Brother Company will gladly send you prepaid by parcel post a one- or two-dozen carton of any size of Edge- worth Plug Slice or Ready-Rubbed for the

same price you would pay the jobber.

LITA EAL ATOLL AAA ET ETE NTE ean

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~ eee te tat hee eeebpere et yen nh Sa sh reg eet & aS eee ~ ni AA aE SES a Sees SR ON UB ae, la RR A Le 108 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY “Another $50 Raise!’ “Why, that’s the third increase I’ve had in a year! It shows what special training will do for a man.” Every mail brings letters from some of the thousands of students of the Inter- national Correspondence Schools, telling of advancements won through spare-time study. How much longer are you going to wait before taking the step that is bound to bring you more money? Isn’t it better to start now than to wait for years and then realize what the delay has cost you? One hour after supper each night spent -with the I. C. S. in your own home will prepare you for the position you want. Without cost, without obligation, mark and mail this coupon, Do it right now! “ao ow ow eo oe oe eo oe oe ee ee ee ee ew am = INTERNATIONAL CORRESPONDENCE SCHOOLS Box 7672-C, Scranton, Penna, Without cost or obiigation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X: BUSINESS TRAINING COURSES Business Management 0 Salesmanship Industrial Management L) Advertising Personnel Organization Better Letters Traffic Management Show Card Lettering Business Law Stenography and Typing Banking and Banking Law Business English Accountancy (including C.P.A.) (J Civil Service Cost Accounting Railway Mail Clerk Bookkeeping Common School Subjects Private Secretary High School Subjects Spanish O French Dlustrating TECHNICAL AND INDUSTRIAL COURSES Electrical Engineering Architect Electric Lighting Blue Print Reading Mechanical Engineer Contractor and Builder Mechanical Draftsman Architectural Draftsman Machine Shop Practice Concrete Builder Railroad Positions Structural Engineer Gas Engine Operating Chemistry Pharmacy Civil Engineer Automobile Work Airplane Engines Surveying and Mapping Agriculture and Poultry Metallurgy O Mining Engineering [) Radio Mathematics EE Street STI upiies tsuseednentahaccescencnbaneenopebeibenicindiessbpesercesenenibheenseecess SF iis cancinese --- State... BIND. cnncnscnssesscssocnsbeaneiabbecseed Persons residing in Canada should send this coupon to the International Correspondence Schools Canadian, Limited, Montreal, Canada I OFFER YOU $200 A WEEK ** We on ont women in -— community to demonstrate an —=—— orders for Comer All-Weather Coats. Yc ha® | New offer enables you toearn $200a_ gee week and a Buick Touring Car. la YA No collecting or delivering. No @} experience needed. Mail the Q . coupon now for full details. The Comer Mfg.Co., Dept.BO-44 Dayton, 0. Just Mail This NOW The Comer Mfg. Co., Dept.BO-44 Dayton, O. Without obligating mein any way please tell me how I can make $200 a week and get a Buick Touring Car. TOURING CAR Name Address. Print or write plainly Miniature Kitchen Cabinet (Continued from page 107) on the inside with corrugated joint fast- eners. The frame for the front is then made from 34 by 14 in. material (not plowed), the ends and front assembled, and the bot- tom and shelf put in before the top is nailed on. After the top is on, the back panel is fitted and nailed. The frame for the front of the top sec- tion, made of 34 by 14% in. material (not plowed), is cut and assembled and the end pieces cut to the shape shown. The front is then nailed to them. The shelves and top are next put on and the back fitted and nailed. The doors are then made and fitted. In making the doors for the top section, one edge of the plowed 34 by 1 in. material is cut out in order to allow the glass to be in- serted from the inside. The glass is held. in place by small wooden strips. The cabinet illustrated is made of cy- press, stained with dark oak oil stain and varnished. Another neat finish is ob- tained by giving the cabinet one coat of flat white paint or enamel undercoat and one or two coats of white enamel. Sardine Cans Make Handy Nail and Screw Holders HE next time you have sardines, do not open the can in the usual way, but cut half- way around the top and rem SS , ove all but Pe ! SURPLUS ry YY in. of the WITH CAN AND BEND flap, asshown. opener INWARD After the can has been emp- tied and cleaned, bend back the 1-in. strip to make a smooth edge, then punch a hole in the can so it can be hung up as a con- tainer for small nails, screws, tacks, and the like. I have been using this idea in my home workshop for a number of years and find it a good one.—HAROLD GUSTAF- son, Chicago, IIl. Old Dry Cell Aids in Cleaning Sooty Flues (CASS ee the soot from furnaces, stoves, and chimneys is a disagreeable job, but it can be made a lighter task by simply tossing a discarded dry battery into the stove or furnace at some time when there is a particularly hot fire.* This will quickly dissipate much of the carbon and soot formation, and, if re- peated from time to time, soot will not accumulate to any extent. Scrap zinc in any form has a similar effect and may be used if an old dry cell is not at hand.— GLEN F. STILLWELL, Collinsville, Ill. A workshop use for discarded cans Liguip wood filler and substitutes for varnish should not be used as a first coat on floors, as the durability depends largely | upon the first coat. n Davey needs young men John Davey’s organization, The Davey Tree Expert Co., Inc., has a limited number of openings for ambitious young men be- tween 20 and 30 years of age, single men preferred. The opportunity is unusual, of- fering good pay at the start, permanent employment in the Davey organization, and thorough scientific training in the pro- fession of Tree Surgery. Advancement rapid, according to merit. The work is fascinating, of- fers chance to travel extensively, and association with finefellows. Only clean, red-blooded young Americans, lovers of the outdoors, need apply. Write, giving full information to The Davey Tree Expert Co., Inc., 55 City Bank Bldg., Kent, Ohio, Home Protection with an ASTRA Automatic will cost little Nearly every man wants a gun in the house—he feels better able to protect his family. We are able to offer these enuine Astra guns at special prices a we ge before — — raises became effective. eally fine ns, beautifull finished, hard hitting. Use standard rath nM vg Order direct from U. S. importers. $7 15 25 calibre—7 shot—C. O. Q. Automatic. 8.96 25 calibre—7 shot—Astra Automatic, 9.96 25 calibre Astra with triple safety. 10.96 32 calibre—10 shot Astra, extra magazine, 16.95 32-20 and 38 cal. swing-out cyl. revolvers. We guarantee every gun against defective work- manship; brand new; of Drop nee Steel Through- out. efore buying any weapon INSIST on this guarantee. SEND NO MONEY unless you us Neg pF % or m ed. Write for new firearms catalogue. —_ CALIFORNIA TRADING CO. ei Los Angeles, Cal. AccOUNTANT Dept. 11, Terminal! Bidg., are earni 000 to $10,000 a year. in you thoroly by mail _— tine ‘or C. PAS examina Or executive encoun fr not 0 . K to 5 ig under th f William B. hols, A. M-« C.F a. “former Comperoler and ‘instructor Poiversity of Illinois; oO s The Largest Business Training Institution in the World Be a Fincer print Fxpert, Learn SCOT- LAND YARD METHODS, Big Pay, Knor- mous Rewards, We teach you how ons arrang t or you #8 soon se berg. Soliant Sout, SE y for abou ‘: iD YARD, and how oa ger Print Expert. UNITEO DETECTIVE TR. ASS'N., 807 Dinan Bidg., Detroit, Mich.

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ully rder | 83 Feseeratees RQ ES B OFabes HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY — One-Tube Radio Set (Continued from page 79) nected with binding post K, while binding post No. 2 of the same rheostat is con- nected with the remaining F terminal of the socket. One of the rotor leads is then connected with the P terminal of the socket, while the other lead is connected with binding post J. No leads are connected with bind- ing post M, this post serving as the con- nection between one phone terminal and the positive terminal of the B battery. In operation, the aerial is connected with the aerial post A and the ground wire with the ground post B. The negative of the A battery is con- nected with binding post K. The positive of the A battery and the negative of the B battery are connected with binding post L. The positive of the B battery and one of the phone terminals are connected with binding post M, and the other ter- minal of the phones is connected with binding post J. Quickly Made Wooden Sleds Friar agin they have flexible steel sleds, my boys, at the first fall of snow, kept trying to slide down a snow- bank on boards. I split a short length of round stove wood into quarters, and 1 in the base. Just Plug it in— No extra resistance coil required A combination adapter and resistance coil for UV-199 and C-299 Radiotrons, It fits any standard base socket. A coil having 18 ohms resistance is embodied In changing to UV-199 or C-299 tubes, it is only necessary to connect to a filament bat- tery of proper voltage and insert this com- bination Resistance-Adapter. It is unnecessary to substitute a high resist- ance rheostat or use an extra coil. The re- quired .resistanc: is obtained by using this combination Resistance-Adapter in series with a low resistance rheostat (4 to 10 ohms). Ask your dealer for it. Price, $1.25 EISEMANN MAGNETO CORPORATION William N. Shaw, President 40 THIRTY-THIRD STREET, BROOKLYN,N.Y. A safe sled for little tots, made of box wood, and a board toboggan nailed one of these quarters to the front of a wide board. This makes a first-rate toboggan, as shown in the photograph, and the children have lots of fun with it. Out of box boards in about half an hour I also made a wooden sled that is safe and practical for a three-year-old.—H. T. Double-Slotted Adjusting Screw for Awkward Places HEN it is-necessary to use screws in inaccessible places, especially for adjustment purposes, the difficulty of’ inserting and pouate turning the screws can be reduced by making them as shown. . This type of screw has a spheri- cal head and two slots at right angles to each other. A — pilot on the end of the screw guides it 6 into its hole. This YY = is a method I have V/s Vf used to advantage Y// pps in assembling tele- scopes.—O. S. M. “hee has pacierive “Experiments With 110-Volt Alternating Current” ERE at last is a book that gives a practical working knowledge of the alternating current. The only way to gain a thorough understanding of electricity is by direct personal experiment. How a practical knowledge of the alternating current can be gained in an interesting and inexpensive way is shown. The knowledge that comes from experiment is of vastly more value than that acquired from the performance of the stereotyped series of battery ex- periments usually described in books on Alternating Current. The book “Experiments with 110-Volt Alternat- ing Current” is needed by every man experimenting with alternating current. 256 pages, 135 illustrations. Price, postpaid, $1.75 POPULAR SCIENCE MONTHLY 225 West 39th Street New York City The Wireless Experimenter’s Manual E. E. Bucher ‘TSS book thoroughly covers the entire field of amateur radio work, including the theory and design of amateur wireless transmitters and, re- ceivers, the construction of trans- formers, high voltage condensers, spark gaps, aerials, masts, and receiv- ing sets for long and short wave fe- ception. 330 pp. Fully illustrated. Price $2.25. POPULAR SCIENCE MONTHLY 225 West 39th St., New York City, N.Y. Imported from Japan **It makes Carbon Copies’’ Hustlers Making $20 Daily! Money refunded if you don’t think it’s the best pen you ever wrote with. Up to 150 per cent Profit. Send for quantity price list and distributing plans. F. SPORS & CO., 199 S. 4th St., Lesueur Center, Minnesota SELLS for $1.25 AGENT’S SAMPLE 65c.! New Self-Filling Bamboo Fountain Pen with Stylo Point ‘i Ideal Guaranteed for 1 year feat Reta “eolcnnnonniaeeth abt ates * eto — cod Toe Sa abacedaes aoe angele

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vor ether 110 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY © The Supreme Insulation —~ RADION Panels are easiest to drill, saw, or engrave with simple tools at home 18 Stock Sizes Radion Panels 6x7 6x 104 6x14 6x 21 7x9 7x10 7x12 7x14 7x18 7x21 7x 24 7x48 9x14 10 x 12 12x 14 12 x 21 14x 18 20 x 24 07 QUBBERCO.NY AMERICAN HARC imitations, American Hard Rubber Co. New York 11 Mercer St. Look for this stamp onevery Ate eis —— orange iN RTS anel. Beware o RADION Denver’ substitutes and Transforming an Old Pedestal Dining-Table By Stanley W. Blanchard TYLES in home furnishings are changing. The living-room is ex- panding and taking in the dining-room. It is now quite correct for dining- and living-room to be merged into one long room. Houses are being built this way and the partition is being torn out in old houses to achieve the same effect. The transformation of the two rooms into one calls for some arrangement of the furniture, but this presents no great difficulty, except the problem of what to do with the dining-table if it is of the pedestal base type. Instead of fitting in with its surroundings, it insists on stand- ing out and proclaiming itself to be a dining-table and absolutely nothing else. The problem was well solved in one case by removing the top from the base, Half a pedestal dining table recon- structed into a three-legged writing-table discarding the latter, and fitting each half of the round top with three square, tapered legs, thus making two half- round tables of pleasing lines. These take up little room with their backs to the wall and yet can be moved out and placed together in a minute for duty as a dining-table. This plan makes an exceptionally con- venient arrangement for the small apart- ment where space is at a premium, but it may be used in any home, as additional space is always welcome. If you have a dining table that is not being used, or possibly has the base broken, it can profitably be made into a pair of these tables. One of the halves can also be transformed into an attractive writing desk by the simple addition of a back that projects above the top for 6 or 7 in., and a rack for letter paper and envelopes at each end. The accompanying illustrations give a good idea of possible construction in making the changes, but as all dining tables are not the same, it will be neces- sary to use your ingenuity. The same kind of wood should be (Continued on page 111) Make Money Taking PICTURES Tremendous, big-paying opportuni. ties are open for ambitious men in Modern Photography. This jg the picture age. Magazine and news. paper publishers buy thousands of hatagragee each year. Every manufacturer sends out high priced ‘very pictures of his products. home wants portraits. Photography is a business run. ning into millions of dollars each year. And there is a great shortage of trained photog. raphers. EARN $3,000 T0 $10,000 A YEAR Hundreds of men are earning big money and establishing their own businesses. Even spare time, while trainings, you can make $75 a week easily—no matter where you live! Got $100 for Flood Pictures **T took pictures ofa flood and sold them for $100. I have been le to buy my house and lot from the sale of pictures.’’ Cc. M. COLE, Washington. $97 in Two Days! **I made $285 in De- cember. Went out two days last week on home rtrait work and made ‘id A. G. HUGHES, Kentucky. Amazing New Easy Method I show you, at home, how to do the kind of work turned out by the Lig studios in New York and Chicago! [| show you how to make big money within 30 days! C. M. Cole bought a home with money he had made when only half way through his training. So well do I know what I can do for you that I guarantee under bond to return 7 cent of your tuition if you are not thoroughly satisfied. View Camera Freel Write at once for Free Camera Offer — I give you, free, a splendid profes- sional view camera. You will be as- tonished and delighted. This offer open ‘or short time only—so act cuick. Ne obligation. INTERNATIONAL STUDIOS, Inc. Dent. 2381 3601 Michigan Avenue, Chicago, U. S.A, led teshentl WEAR ‘oavs FRE OUR MARVELOUS MEXICAN DIAMONDS have delighted thousands of customers for 18 years. They diamonds. ry y me same dezating play of w fire. Stand intense acid test of side y 5 need their experience to detect any % nape pokes ou admire on your closest friends are MEXICAN DIAMONDS and you never knew it Test a2 MEXICAN DIAMOND FREE; you risk nothing. Wear it seven days side by side with a genuine diamond. If you see any differen back HALF PRICE TO INTRODUCE experts itively whatever. Per- m Uc. - $2.63 —Gents Heavy Tooth Belcher, 1 ct.gem, 14k gold f 3.28 — Ladies 3 stone Duchess ring, fine platino finish, two 6/8 ct. first water Mex. diamonds, one biue sapphire. 5.90, Ne. 4—Gents Ex. Heavy Gypsy Ting, platino finish, black cEN on sides; 1 7/8 ct. first wate ater Mex. Di P a SEND NO MONEY passresce tse" tna Ras inger to sho Say which ring you want. We ship arrival, d t price with tman. 7) jo) lute’ Co S' LAS CRUCES, MW. MEX. P.O. if Exclusive Controllers of Mezican Diamonds for 18 years. Py nt not to keep it, return fa 7 days and we'll retund | money. Write TODAY. Agents wanted. Weenie DIAMOND IMPORTING CO. Fine Tone $2 ae instruments have a _ wonderful new epee ted le, ¥ -Guitar, perb Violin, Tenor . Ukul i ssons only, Four you several pieces. ntee mplete outfit free. Write lay, Dept. lingerland Scheo! of Music, 1815 Orch FOR CLEARER SIGNALS FRAMINGHAM DE LUXE PARTS system of teaching note an by mail! To first pupils in each locality we will give free & * Ban jo-Mandolin, ¢ t or Banjo-Guitar abso- é 19 ag age and O an. Very email charge for le cces® harge "166, No obligation. ard St., Chicago, tll. nina an A

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HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Transforming an Old Table (Continued from page 110) used, if possible, in making the new back and legs as was in the original top, unless the table is to be painted. The finish on the old table top should be removed entirely with varnish remover and well Qe THE OL FAMILY DINING TABLE PAIR OF a” CONSOLE , TABLES USED WRITING ASA DINING _- TABLE TABLE --~~ Suggestions in remodeling a pedestal dining table and method of withdrawing the sockethead screws sometimes encountered sanded; then the whole table can be refinished at the same time. In taking the old table apart, it may be found that screws with a square socket in the head were used in fastening the parts together instead of the usual slot. A key to remove them can be made by filing the end of an ordinary screw square to fit in the socket. One half of a small dining-table can be converted with a little ingenuity into / MORTISED AND GLUED “= CORNERS ~’ Details of the mew rear-leg con- struction (above) and the method of fastening the center leg (below) a dressing-table if a back, fitted with mirrors, is added. The results obtained in rebuilding old pedestal dining-tables are so pleasing that it might pay to purchase a second- hand table, if necessary, as the finished tables are worth from $20 to $25 each. FUMBLING for the keyhole when unlock- ing ‘the door in the dark is obviated by gluing a hand of an old luminous watch so that it points to the keyhole.—C. D. T. From New York to Honolulu With Erla Synchronizing Transformers Uy, led d power, over a waveband of 200 to 700 meters, is assured by Erla synchronizing reflex transformers. List, $5 each Unduplicated amplification without distortion enables Erla audio transformers to improve any receiving unit, Ratios: 3% and 6tol. $5 . Solve crystal troubles by in- stalling an Erla fixed c: rectifier. Once installed, no attention is required. jolt and jar proof. List price, $] Dealers and Jobbers: Erla scientific advancement is reflected in sensationally in- creasing 4 tho pales and a febher dapler gaght. Waee or our liberal discounts. = “AIU.S. Stations on Loud Speaker, Using Only Three Tubes” Typical of the thousands who have discarded complicated multi-stage receiving units in favor of simple, efficient Erla reflex design, is the experience of J. G. Hamock, 1917 So. Western Avenue, Chicago, who writes: “During my first week with your three-tube hook-up, tuning through high power Chicago stations, I got Jefferson City, Dallas, Memphis, Atlanta, Omaha, Kansas City, St. Louis, New York, Springfield, Pitts- burgh, Harrisburg, Louisville, Cincinnati, Fort Worth and Tampa. “The Sunday following I added Fresno, Denver; Astoria, Ore., Los Angeles; Honolulu, Hawaii Naval Maneuvers; and Juneau, Alaska, the Alaska Electric Light and Power Company. “The United States Stations all were clear on the loud speaker. Also I re-tuned every station by checking them with my twelve-year old son, who would get them on the re-tune, whereupon I would, when required, sharpen the re-tune myself.” Such power, selectivity and ease of control, with three tubes, are attainable only through Erla reflex design, incorporating Erla synchronizing radio and audio frequency transformers. _ Guaranteeing the perfect synchronization of received and reflexed currents having the same phase characteristics, Erla transformers enable vacuum tubes to do triple duty, as simultaneous am- plifiers of received radio frequency, reflexed radio frequency and reflexed audio frequency currents. For complete details, ask your dealer for Erla Bulle- tin No.14, giving Erla one,two and three-tube reflex hookups. Or write direct, giving your dealer’s name. Electrical Research Laboratories Dept. F 2515 Michigan Avenue, Chicago * ERLA lil $25.00 in PRIZE of book for details See top of page 6 in front al, Yow dang deiciah teat Gatien The Skate for Pleasure The Finest Tubular Skate and Shoe Made . Used by the World’s Greatest Amateur and Professional Skaters. For Sale by All Good Dealers or Direct from Factory. Factory and Salesroom Dept. PS, 2846 W. North Ave., Chicago, III.

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A awe ego ee ae ae a aA be Teh Di Rg tiles Stee POA cot FE nS eRe a EN Sea Tees aaa” 112 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

‘Sera frail Sagat et ee ewe ice Great NE Ww, Invention for seekers of

Beauty E£lco Health Generators at last are ready for youl! If you want more health —greater power to enjoy the pleasures and de- lights about you, or if more beauty is your sire—write! As for the book on these inventions which has just been pre- pared. It will besent to you without cost. It tells you how Elco Health Generators aid you in leaving the lethargy and hopelessness of bad health and weakness be- hind forever. Re-vitalize ee. Bring back en- ergy. Be wholly alive Write today! 10 Days FREE eo Write for FREE Boo

Hectric Health - “Generators These great el —_ F T ial tions generate Violet Ray, Vibration, Electricity and ree rl Ozone—combined d or separate. They operate on the electric light in your home or on their own motive power at less than 50 cents per year. Elco Health Generators are positively the only instruments which can give you in one outfit Electricity, Violet Ray—vVibration and Ozone—the four greatest curative agents. Send the coupon below. Get the Free Book NOW! For All These: Rheumat Paralysis Sore Th cat re maples Block Heads pallies ng piste Catarrh eo omen Purvousness

Develo t

Mail cian Power for Free Book | 5” Do aod ed this paper down with- out sending the coupon. Don’t go on as you are with pains and with almost no life and energy. You owe it to yourself to be a better man or woman. You were put here to enjoy life—not just to drag through it. Sodo not rest another day until you have put your name on the coupon here. That will bring the whole story of these great new inven- tions. Do it today—now. Lindstrom & Company bee me om 442-448 N. Wells St., Dept. 13-61, Chicago. a onl ) Please send me your free book, ‘‘Health—Power— { Beauty,” and full information of your 10-day Free ; Trial offer. I

} I cirieke nnn em nceneconse l State te Representatives W: Wanted

Parlor Ringers Played with Rubber Horseshoes By Roland B. Cutler UTDOOR sports seldom can be brought into the house without losing action, but realistic barnyard golf can be played in the “best room” with the home- made equipment illustrated. Pitching horseshoes is popular with everybody and the indoor game calls for the same skill of hand and eye as the out- door. With an old automobile tire and two 10-in. pie plates you may make parlor equipment that is as reliable as it is inexpensive. Each plate is fitted with a wooden bottom made of 34-in. matched stock in two halves. A broomstick stake, 33 in. long, is inserted in a hole in the wooden base and nailed in place. The stake is

re) LEAD woe ® sal . ta WS oar Pitching horseshoes indoors with equip- ment made from an old auto tire, an inner tube, pie plates, wood, and wire “4

then passed through a hole cut in the tin plate and the plate is nailed to the wooden bottom. About 22 in. of lead pipe is then wedged around the bottom against the rim of the plate and nailed to the wood. A rubber jacket provides suitable “ground” and protects the floor. It is an 18-in. length of discarded inner tube. Open it up to inclose the plate and fasten under the bottom with lacing or tacks. Reinforce it with stitches at each corner, as shown. The four shoes should be about 84 by 5 in. A knife and hacksaw will cut the tire. Although pitchable “‘as is,’”’ a shoe can be shaped almost rigid with heavy wire such as a pail bail. File a groove for the wire and point the ends into the “‘calks.” Slip a suitable rubber tube over the wire, and fasten in place with shoemaker’s thread. Play the game according to thé scoring rules of the National Horseshoe Pitching Association, which are as follows: Only shoes that remain within 6 in. of the stake shall be scored or counted. A leaner is counted asa closest shoe and has no advantage over a shoe lying on the ground and against the stake. When each contestant has a ringer or double ringers, they are counted as equals—credited as ringers pitched but not counted to score. All plays that are equal count as ties and do not score. If all four shoes tie, such as ringers or being an equal distance from the stake, the contestant who pitched last is awarded the lead. Score one point: for a shoe closest to the stakes for the next closest shoe when each contestant has a ringer. Score two points: for both shoes of a contestant when closer to the stake than opponent’s. Score three points: for a ringer; for one of the two ringers of a contestant when ‘there is one Op- ponent ringer. Score four points: for:a ringer and a closest shoe. Score six points: for a double ringer—the highest count a contestant can make.

Written 2-Year Guarantee Your Proof of Performance SPECIAL CHRISTMAS OFFER Thousands of Popular Science Monthly Readers will profit by this amazing offer. They will buy the famous 2-year guaranteed World Battery at the lowest price ever quoted. They will get their choice of a hydrometer and a ‘‘B” Battery or a nickeled Auto Spotlite FREE. And they get the best battery built, with 2-year ironclad guarantee, Compare These Prices Automobile Prices Radio Prices 6 Volt, 11 Plate = - $12.25 a7 ee rd, Chev., Mitchell, Hup., For W.D. 11 and W. D. iz Elgin, Tubes. Will Eo bourp ca 6 Volt, 13 dg -- “a gne e. argeable, Overland Buick, Reo, Paige, "Race! © Volt Storage Bee. “= = = $8. dson, Nash, Stude., Dort. For U. V. 199 Tubes. Same 12 Volt, 7 Plate - - $17.00 features as 2 V Amps. - $8.59 Maxwell Dodge, Regal, ° nak ipaeermataee: — S¥ae Ramos, > i olt, 120 Amps. - 14.59 Give year and model of car. Hy Volt. 140 Amps. - 16.09 SEND NO MONEY You need mot, send a penny. Just clip this ad. and mail wi your name and address. The batte: tery you you , specity will be pote to you the day dope order is receiv n the battery arrives, inspect it— our 2- 2-year wuarantes before you pay one pe 7 ce yourself rotected from eve ene le- ie World Battery saves 9 you ou 50 per cent. Get the 5% mt the ad. ond onal oa WORLD BATTERY CO. 1219 So. Wabash Ave., Chicago, Ill, Nickeled ‘Your Choice 2**3,.4. at aoe od or Auto Spoti'te FREE. Clip Dept. 7,

“ B” Battery and Hydrometer

Gear With Ait-Friction Carburetor _. And we guarantee all other cars nearly double present mileage, power and flex- ibility, make hills on high formerly diffi- cult on low, Models for any car, truck, tractor, marine or stationary engine, See wonderful mileage guarantees— on gallon of gasoline for other cars. Makes old cars better than new. Ford __. 34 mi. J Reo. ..24 mi. } Chevrolet_32 mi, Buick 4..30 mi. | Chal’rs_23 mi. | Maxwl(25). 30 mi, Buick 6__24 mi. ]| Olds. 6 _23 mi. | Nash 6 ___. 23 mi. Hudson .20 mi. | Paige 6.20 mi. | Lincoln 8 17 mi, Hupp.._.25 mi. | Oakl’d6.24 mi. | StdbkrLt6..23 mi. Dodge.._.28 mi. | Overl’d4 32 mi. | Cole 8 ___-- 17 mi, If your car is not mentioned here send name and model for particulars and our guarantee on it. Agents Wanted,

SENT ON 30 DAYS’ FREE TRIAL. You can drive any car in heaviest traffic without shifting gears. Starts off on high in any weather without priming or heating—no jerking or choking. No more foul spark plugs or carbon in cylinders. No leaking of gas into crank case. Try it 30 days on our guarantee of money back if not Sri at satiated. No strings to our guarantee, YO DGE. Anyone who can handle a wrench can Pie. | iu "ae boring of new holes or changing of operating mechanisin. Write today. AIR -FRICTION CARBURETOR , 17 Raymond Bldg. Dayton, Ohio, U. S. A.

Ct) Me oe Write today! OTTAWA MANUFACTURING CO.., 1951Y King St., Ottawa, Kansas. Desk 1951Y Magee Bidg., Pittsburgh. Pa. An Ideal Git only 50c orcio.o. Pocket Identification Holder It is always necessary to have your indentification, lodge or fraternal receipt, or age valuable Paper with you— attached to-watch chai ey Ley | can’t be lost!

Weather proof! Hendeomely ni snickeled, ; Sones ite Z syeusys fgrmithed olen wth 107k of corde 2 inghaal or YX ockat. ‘urnished com cor c. ~ Only $1.00. io see today.—ask f. or circular of other : item a. INSTITUTE MFG. CO., Dept. 301, 311 Main St., Worcester, Mass, SEND NO MONEY jn! Settions-4 sente le and objects miles away — _ were close, see Moon and Stars you never did before. B sarc and entertaining. tell lane 4 miles

~ =< + eh eH LIA ct TM

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.\ SESSSES Sener fet ranet Pi aH "— a 8 PHL ‘Inlaid pn for Typewriter Keys Made of Sheet Rubber O CUSHION hard typewriter keys and do away with their tiresome glare, it is possible to make quite cheaply a set of inlaid rubber caps. All you need to purchase is a small tube of rubber cement and a piece of soft, thick sheet rubber, costing about 25 cents. A piece of blackboard chalk and a pair of shears also will be needed. From the sheet rubber cut small disks that will just fit the tops of your typewriter keys. Then, with a hot nail or wire, melt into each its identifying letter or number, and fill the depressions with a paste of rubber cement and a little powdered chalk. Clean off any surplus paste with benzine. Allow the disks to dry in a warm but not hot place. When perfectly dry, fasten the caps to the keys with rubber cement. They will stick well and stand hard usage, although you can remove them at any time by slip- ping a knife blade under them. That will leave the regular keys in as perfect condi- tion as when they were first covered.— KENNETH B. Murray, Sturgis, Mich. Two of the caps in place How to Construct Some Simple Farm Machinery Bearings wo a farmer and handy man hesi- tates to build simple labor-saving devices and light machinery because of the lack of suitable bearings. For such ma- chines the type of bearing illustrated is one of the cheapest and best. It is of the split type, made of iron, both halves being cast over the same simple pattern. Holes are drilled in the inside for anchor points for the Babbitt metal lining and the upper cap is drilled for an oil hole. These bearings are mortised intc the sills or frame of the machine and therefore DRILLED pa HOLES The assembled bearing, both halves of which are alike, and a cross section showing anchor- age for Babbitt metal are rigid so far as end play is concerned. Side play is prevented by two )-in. bolts that pass up through the wood and screw solidly into the lower half of the bearing. The holes in the cap are drilled a sliding fit over the bolts, which aline the cap per- fectly with the lower half. The halves of the bearing are 1/16 in. below and above the center line to make room for the shims made of soft pine. ‘Three simple patterns of different sizes will handle nearly all sizes of shafts usually found on farm machinery. A Coal-Saving of at least 204 ts Ginette to every user of the CROWN fuel Javer Guaranteed in this case means just what it says. There’s no hokum about it, no “ifs” or “‘buts.”’ Properly attach the CROWN Fuel Saver to the feed door of your heating plant and we guarantee you an actual saving in fuel of at least 20%—or we will refund your money without question. The price of coal isn’t so low that you can afford to ignore this offer—particularly as the CROWN is comparatively inexpensive. Many users of the CROWN obtain fuel savings up to 50%) Over 10,000 satisfied users of the CROWN are getting more heat, steadier heat and cleaner heat. They are cutting down their coal bills 1/5 to 4; eliminat- ing smoke and deadly gases; and re- ducing the number of trips to fire the furnace. The CROWN pays for itself One user says: “I have burned only half the amount of coal.’’ Another says: “TI am saving from 40 to 50% of coal and the house 1s always evenly heated.” (Names on request.) What the CROWN is The CROWN is a small device which Meat FROM PERFECT '/, COMBUSTION SMOKE UNBURNED GASES Sy lied may be easily bolted to the feed door of any type heating plant without injury to the door. The CROWN (see illustra- tion) provides, by means of natural draft, an auxiliary supply of hot air over the surface of the fuel bed. This hot air (oxygen) burns the rich gases that are ordinarily lost thru the chim- ney in the form of “smoke.” The CROWN turns this “smoke” into intense heat and assures almost perfect combustion. The CROWN FUEL SAVER works automatically. There’s nothing to take care of; nothing to get out of order. It is easily installed without putting out your furnace fire. Write today for details Don’t put off learning about the amazing heat-producing and guaranteed coal-saving powers of the CROWN Fuel Saver. Begin your coal saving now and keep every room in your home comfortably warm in any kind of weather. Write today for details and prices and for our interesting free booklet ‘‘Making the Coal Bill Look Like 30 cents.’”’ As the CROWN comes in 4 sizes, give name and make of heat- ing plant and approximate size of grate. CROWN FUEL SAVER CO. 12 N. 10th St., Richmond, Ind. Keep your home sy warm and save coal with the CROWN Fuel Saver ‘ Write for interesting profitable proposition. Every home, business house and factory a prospect. 113 : Easv to to have more eggs to yr sell. Prices ing up i oe Startnowtodouble eandtrebleegg yield by following Prof. T. 5.Que 8 enberry’ eecnsetional meth Free Book Tells How. 60 Eggs More Per Hen Guaranteed! » Know Eggs More per year. fy 6 sinking Festa Prof. Gulsenberry a een Tells how to make hens shel! ou eggs; to ogee on fe how to call = po This book i is FREE ‘send Retcwk include a STRAIGHT-FROM-THE-SHOULDER TAL about your future in the electrical field. no misle: ading, promuiecs such as, YE or ‘““BECOME AN E LECTRICAL EX- PERT IN AFEW MONTHS? DO YOU WANT A BETTER JOS? intelligent to believe such rot. GET THE santnt? F MY 25 Mt2 EXPERIENCE LECTRICAL ENGINEER erts endo B. .. i. ~ course. Rake Course presented to everyone who answers this advertise- help yourself and those depending on you, write for my Catalog. RGESS ELECTRICAL tT te Yorke Burgess, Supt. Be 746 E. 42nd Street Chicago. i. Canadian Branch, Send for my HOME-STUDY fot AS which = it ocatbes “EARN $10,000 A If you are seeking to better yourself, you are far too I am in business to help deserving men as I have helped thousands. want to help you if you will permit me todoso. My instructions are right to the point. My catalog speaks volumes for any man who wants to be a success in the electric: -4 field. Evectrical fend Book and Slide 4 for prompt enrollment. If you are sincere and want to Sie Crawford St., Toronto

Page 90

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tae Seamer ro 06 ee a ae ha ai ilat oa

GA gy > ae SEN 3 ed ae es 114 Takes Only 60 Days to Get a Real Job in the Auto and Tractor Business Read what these men are doing— here is your big chance to get ‘‘on easy street.’ Ramee to these great shops on the biggest FREE offer ever made. Big Firms Need Trained Men The Auto and Tractor Business is on the boom. Thousands of trained men will be needed during the next few months. I get calls every day from Garages, Battery Stations, Auto Repair, Welding Shops and other suc- cessful concerns for Rahe_ men. When the big fel- lows need high- grade men they

“My = garage and Ford Agency is a big succe 8s, 1 . a7 fake’ know where to owe i oO ane raining.’ * G. Smith, W come for them. Ohio. » W. Alexandria, They Want Rahe trained men. My Training Unusual Scientific tool training—that’s the secret. You do things here according to the latest engineer- ing standards. Thousands of dollars have been spent in modern tools and equipment. That’s why my men are at home with the biggest shops The Great Rahe School in the coun- ison : 2 try. If you want to suc- ceed the way Smith and Metzger and the rest have —qualify by the same method. I’ll Pay Your Railroad Fare and Board You! In order to fill the openings that now exist, I am making an offer no one has ever made before — Free Railroad Fare. Free Board. But even that is not all. I'll tell you about the rest in my letter. Send for FREE BOOK My big illus- trated training book tells how others are suc- ceeding. It tells many things you ought to know about Autos and Tractors. Write for it and my short time offer NOW. It soon

“Rahe Training was the best investment I ever made.” Colby Lord, Oak- land, Maine.

“I thank Rahe Training for a great job in the best garage in Lima.’’ Howard h Metzger, Lima, Ohio. expires. Tractor & Rahe z=: School Dept. 260, Ninth & Walnut Sts., CINCINNATI, O. RAHE AUTO & TRACTOR SCHOOL, Auto

1 Dept. 260, Ninth and Walnut Sts., | Cincinnati, Ohio Without any spliantion. send me I your big free The Evolution of Transportation.” Also informa- ] tion regarding special temporary offer. 1 1 eee ee 2 Oe Sr See eS, I Pn setednsertenecten nw uden Mate... a0

Learning to Skate with an Ice Merry-Go-Round O LEARN to skate without bumps and mishaps is a simple matter if a skating wheel is constructed as shown. A post is set through a hole in the ice into the mud below and allowed to stand until it is frozen in solidly. On it is pivoted a

\ - ae UB O1D suare_ A a CENTER STAKE RUNNER DRIVEN INTO MUD

The beginner in skating is upheld by a re- volving cross arm, pivoted to a central post long 2 by 4 with braced vertical legs at each end. These legs are fitted with old skates to form runners. - With the bar for a support, the beginner can skate round as fast or slow as he desires.

Hand Stove for Skaters OR skating or coasting parties, the cheaply made stove illustrated gives sufficient heat to warm chilled hands. An old bucket is needed for the top; a discarded kettle serves for the bottom. The two are riveted together, the kettle being in- verted. Holes are punched about the base of the pail to promote combus- tion.—D. R. V. Burns charcoal or wood

Hinged Platform for Garage A HINGED platform fastened to the wall of the garage affords a conve- nient stand for washing, repairing, and re- finishing the top of a closed car and is much _§handier than a step- ladder. A wooden plank is fast- ened to two brackets, which are attached to the wall stud- ding with bolts about 4 ft. above the floor. The platform hangs out of the way against the wall except when needed. It is then raised to a horizontal position and held with heavy chains. If no bench is available, the platform may be used for tire or other repair work.—G. L.

Platform inameal for use

C1GAR-Box wood can be used for many purposes. How to make attractive inlaid serving trays with it will be told in next month’s Home Workshop Department.

HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

7 Learn e @ Electricity How would you like to earn two or three dollars every evening after school and pre- pare yourself for a fine big job at the same time? Here’s the opportunity of a lifetime for you fellows who like Electricity. Begin right now to prepare yourself for a regular man’s size job in this fascinating field. Your chances for a big success are simply wonderful—the pay is big ($70 to $200 a week) and advancement comes swift and sure. i WILL TRAIN YOU AT HOME With my easily learned, spare time Electrical Course I will train you at home like I have trained hundreds of other boys who are now big successful men. It will not in-

Look What terfere with your school work This Boy and you can earn more than Is Doing the small cost of the course do- ing odd electrical jobs in your spare time. The Course pays for org I = show you how to get this work and how to do examinations, I mar,| it. Some of my boy students my. electrical studies make $10 to $15 a week this way. Tools, Apparatus and Radio Course FREE Send me the coupon below and I will tell you al! about the big outfit of tools, apparatus and instruments and a new Radio Course that I am giving to my students for a limited time. I will send you my big interest- ing Electrical Book and a sample lesson, too—all Free. You will be tickled with the things I will send you Free. Mail the coupon right now. *“*Although the School term is coming to a close, and I am pretty busy with my . e I forgot to tell you I am now in business for myself. Am doing fine, but owe it all to you. ‘If it had not been this town. But I got it, and now have all the work I can do, averag- ing $20 to $30 a week thru spare time work. “Iw out on a job tonight after school, other on which I made $2.50 — ae 50, for 4 hours’ work and no atari “furnished by “ROGER SMITH

1215 Chestnut St., L. L. COOKE, Chief oa Greenville, N.C. hicago ning Dept. A-31 HICAGO

Use This Free Outfit Gauion L. L. COOKE, Chief Engineer, ; Chicago Engineering Works, Dept. A-31 2150 _ preanmcinend Ave., Chicago | l Send me your Free Outfit Offer, your big Elec- trical Book, Sample Lesson and particulars of your Electrical Course and Free Radio Course. | This will not obligate me in any way. WS As foe ao ia reek oceie lo oleiwin ve eiein oLsis)s<oiw oiaieseiars PAMRI BER Sos Sie rare eta ra tate eiaia we essa Mee ee win eee 1 For use of boys 15 years old or more i aaleeteetiostiontantentcntantentatied

send your name, address and oe toe, and we will send you beautiful genuine diamond, | 14K solidgold ring on approve. Send no money; pay no Merely accept the ring and wear it a week, Then decide—either return the ring and call the deal closed, or k it and send np $3.75 a month until our cut Ps 638.75 1 paid. (Regular $50.00 value.) Genuine Diamonds * Each ring lid 14K id, with M EN S RING 18K white td top, ex Sioitely hand en- NO.A4450 ved ith a Site Erilliant, calles ou. blue-white fo anor} ‘pame. address and r sine. Alor your age occupation o4

say you want ladies eee

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. —_ hree pre- ame ‘ime now yb in “cess 00a yurse lreds v big yt in- work than e do- your pays 0 do lents this nd FE y and e big and tadio Oo my rest- id a ree. | the Free. Ww. =" (2) °o o nm Ned D 44 - | . with ind en- , extra e gen- on men's

Pia a a rs vet ee oe a ee

| length of the blade. | the block always flat on the blade. HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY

Cushion of Sand Reduces Noise of Small Stationary Engine or on a layer of sand, any small gas or gasoline engine can be mounted so as to be practically free from vibration and its destructive results. The sand is placed between the wooden skid and the concrete floor as shown. This idea has been in practical use in a smail shop for more than three years and

AK RUBBER WASHERStan RUBBER : AS Sy a ss LEY UAE Zap One BOLT ak pein We iia allel EMBEDDED INCONCRETE SAND CUSHION~3' THICK The wooden skid rests upon a layer of sand and is held in place by rubber covered bolts the bolts in the concrete floor hold as well asever. It should be of particular value to the mechanic who has his shop in the cellar of his home and who wishes to work in the evenings without annoying other members of his family. A depression in the floor is not abso- lutely necessary; a skirt of concrete may be built around the engine base to hold the planking and sand. This will raise the engine about 6 in. above the floor level. Over each bolt a piece of rubber such as ' gas tubing may be placed, as it also helps materially in damping the vibration. —JOHN H. SCHALEK, Pittsburgh, Pa.

Simple Filing Device Keeps Your Scissors Sharp b igpee filing device illustrated sharpens scissors as well as grinding them would do. What is more, any one can be reasonably sure of getting good results with it. Snap off a short piece of a very smooth flat file, and fasten it toasmall block of brass by setting the fileintoa groove and clamping it down with a short strip of brass and a ma- chine screw. The important thing is to set the file at the correct angle. This is best determined by trial, using as large a pair of scissors as can be obtained to make the setting easier. When the block is set flat against the inside of the scissors blade, the file should be exactly parallel with the cutting face of the blade. To use the sharpener, place the block flat against the inside face of the blade and work it back and forth for the full Be careful to keep

r) ' SCISSORS BRASS BLADE. BLOCK How the sharpener is used

If very dull scissors have to be sharp- |

ened, it will pay to use a somewhat coarser file for the first eut.—H. G. |

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FREE single-spring motors. chine. $35 Value for $20 Special offer. steel needles Free. MIRAPHONE Plays all records up to 12 inches. Mechanism very substantial,—made to last. days you are not pe Hard fibre carrying case to fit, $4.00 extra. Trial for 10 days a Phonograph of Quality made by Swiss Watchmakers Has double main spring, playing twice as long as Reproduces as loud, clear and musical as any expensive ma- i Case fancy polished wood. Sold on easy terms; $1.00 down with the order, $3.00 on re- ceipt of machine. Balance in four monthly payments of $4.00. RECORDS FREE We also send 4 records, ten-inch, with up to date music and 100 Everything ready to play. Money refunded, if within 10 rfectly satisfied. $1. discount if fully paid in advance. CO., Dept. P, 16 East 23rd Street, New York pe é Lae Reteeas is.

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ae ete) nn Aes pe Ag Rt ean ED 6 Sa A arene Ire Dy kt a AR eet Sel Notre, Pate Ping Pea EA = : C3 oS ” wipe 116 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY NTHUSIASTIC testimony from an author- ity. The delicate overtones are faithfully re-born through the patented ‘‘double dia- phragm.” Adjustable to your set and individual receiving conditions. Letters from Users Requested $ Write for Illustrated Booklet ‘‘V’’ Sole Canadian Distributors: Marconi Wireless Tele- Ask for demonstration. graph Company of Canada, Ltd., Montreal, Canada Home-Study Business Courses Do you want an important, high-salaried position? You can have one if you can do the work. LaSalle experts will show you how, guide you step by step to success and help solve your per- sonal business problems. Our plan enables you to train during spare hours without interference with your present duties. Give us your name and address and mark with an X below the kind of position you want to fill. We will mail catalog and full par- ticulars regarding our low cost monthly payment plan. Also our valuable book for ambitious men, ‘Ten Years’ Promotion in One.”’ Tear out, mark and mail the coupon today. No ghitcation to you. Find out about the new ‘‘LaSalle Problem Method,’’ what it is and how it works, Let us prove to you how this step has helped thousands of ambitious men to real success. Check and mail the coupon now. ——-—— Coupon — LaSalle Extension University Dept. 183-R_ Chicago, Ill. Gentlemen: Send without obli- gation to me information re- ing course indicated below, also copy of your interesting book, ‘“Ten Years’ Promotion in One.”’ OBusiness Management [Modern Business Corre- CO Modern Salesmanship amy and Practice r Acc tanc Modern Foremanship Pimwerond aaaphenent and Production Methods DRailway Station OPersonnel and Employ- Management ment Management OLaw—Degree of LL.B. [Expert Bookkeeping Commercial Law OBusiness English DiIndustrial Management Commercial Spanish Efficiency O Effective Speaking OBanking and Finance OC.P.A.Coaching Name Present Position Address ...... Sea Super Transformer Audio Frequency Does your receiving set refuse to amplify the bass notes of the piano? Does it make organ music sound like that of an accordion? If so, you are not getting the maximum enjoyment from radio. Recent experiments in the Thordarson Lab- oratory have proven that the low notes of the heavy instruments can be amplified as readily as the high C of the soprano. The Thordarson Super Transformer reaches its amplification constant at approximately 600 cycles and continues at even amplification well past the highest frequency of audiability. Such manufacturers as the Colin B. Ken- nedy Co. and the Zenith Radio Corporation, convinced of the perfect reproduction of the Super Transformers, are incorporating them in all their sets. Install a pair of Thordarson Super Trans- formers in your set and you will hear a radio concert as you have always wanted to hear it. FREE BOOKLET Write for our free Booklet No. 7, which con- tains many helpful suggestions regarding radio receiving. Price (Mounted Only) High Ratio6toi .....«. . $4.50 Low Ratio 34toi.,.... 4.00 Sold by good dealers everywhere THORDARSON Huron and Kingsbury Streets, Chicago ecm 7S et RSME 2 LLG NTE Simple Diffusing Screen Gives Artistic Photographic Effects O SAVE an expense of from $35 to $150 for a diffusing lens for my cam- era, I made a substitute at a cost of a few cents that gives artistic soft focus photo- graphs of professional excellence. A piece of absolutely clear, non-magni- fying glass is cut the size of the camera lens and placed on a clean newspaper. A tea- spoonful of common powdered resin is melted and mixed with enough pow- dered charcoal to give it a grayish - black color. After the mixture has cooled, it is placed in a cup or mortar and powdered as finely as pos- sible by hammering with a pestle or rod. Put a little of the powder on the back of your hand and blow it over the news- paper. When sufficient resin has’ been blown upon the paper, the glass disk will have tiny black specks over it about .01 in. apart. Without disturbing the specks, lift the glass and hect it slightly above a candle flame just enough to start the resin melting and stick it to the glass. Clean the glass and glue it in a 14-in. ring cut from a cardboard mailing tube of suitable size. The prepared side should be toward the inside of the ring. By placing the diffusing screen over the regular camera lens, fitting it as you would a lid on a pill box, you will be able to take soft-focus photos without any change in the time or method of exposure ordinarily used.—K. B. M. Diffusing glass attached to camera Strap Aids when Adjusting Auto Chains in Muddy Weather (>"= of the hardest jobs a motorist en- counters is putting the chains on the wheels when they are buried in a mud hole. Here is a way to do it easily: Rivet a large harness snap to each end of a heavy leather strap about 8 in. long. When the chains are needed, slip the strap between the spokes of the wheel and con- nect the ends of the chain with the snaps. Stretch out the chains behind the wheel so they will wind up on the tire when the wheel begins to turn. After the-chains are on, they may be fastened in the usual manner, or, if you intend removing them as soon as you pull out of the hole, just leave the loose end as itis; it will not hurt anything unless you drive fast enough to cause the loose end to whip out and strike the fen- der.—M. C. METZER, Silver Creek, Neb. Auto chains strapped to wheel VALUABLE suggestions for home build- ers will be contained in a February Home Workshop article.

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m -— om RBAReTaANADA YP — oe aes = ' He Pe aBaoerrwer ie le oe BOT Mee TL IO RRA LE Fe S48 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 117 Hinges Hold Garage Doors from Swinging Shut cree’ hinges can be used at the bottom of any large doors, such as those leading into the garage, to prevent them from swinging or being blown shut. _Above each hinge is a screweye and ring to hold hinge when not in use. These service- able fasteners require no spe- cial parts and can be put on in a few minutes. They are a dis- tinct improve- ment over the makeshift blocks and wedges so often used.—G.L. RING AND SCREW_ TO HOLD HINGE, \ TO DOOR Hinge acts as stop Molten Lead Provides Safe Heat for Difficult Soldering ANY amateur mechanics, like my- self, are without a blowtorch to heat their .soldering iron, and need a con- venient way to keep their iron hot. I have had satisfactory results by using a small pot filled with melted scrap* lead. The temperature is about 600° F. and, of course, high enough to heat my soldering iron. The lead holds its heat for a long time and can be carried into the living- room for soldering the radio set, on the roof for repairing a gutter, or wherever it is not safe or convenient to have an open flame. To melt or dissolve a soldered joint without heat, scrape a portion of the solder clean and apply mercury or quick- silver. This will dissolve the lead in the solder and release the joint. The ad- vantage of this method is that it avoids all danger of fire and of destroying any composition or highly finished parts of a radio set with heat. Quicksilver has no bad effects, either on your hands or the set.—M. FAULKNER, Winnipeg, Canada. Rod and Tube Form Bar of Neat Trammel yee drawing large circles I have found very useful the bar compass or tram- mel shown. A threaded plug for holding a point, pen, or pencil, is screwed into the end of a tube of suitable diameter and length. A rod slides in this tube and at SETSCREW SETSCREWS~” ‘~~ eG ' ‘ ' ! ! ' . (i Adjustments are made by sliding the rod in and out of the tube one end of it is a holder for the other point. In setting the instrument, the rod and tube are telescoped or expanded the de- sired distance and locked by means of a setscrew.—J. H. Moore, Toronto, Can. ' you write them. Cc. J. Buckwal- ter, President, the man behind the remarkable instruction which has as- tonished the teaching profes- sion and which offers wide- awake men a 50-day short- cut to big earn- ings. “egenee LLLP Vp biusy, EE SMS Spo s: 50 Ris ~then IS In New Automotive Electrical Business The shortest road to big earnings ever known. Scarcity of experts makes positions certain and pay high. A remarkable new system of training enables you to earn $132 a week in less than two months. And we can prove it. Get my free book. HINK of it! Only 50 days training puts you in a position to earn $132.00 a week! All because there is an enormous demand for Automotive Electrical Experts and there are far from enough. Employers are ready to snap up our graduates at once. ployment service helps you to get the very “pick” See facts and figures in my free book. Experience Not Necessary YY V4); “Ul nd 13 24 25 26 27 28 219 3v 31 BIG JOBS OPEN FOR AMBU MEN 78% of all auto tro we °. ad Tey ubles occur in tive Electrical Ex- perts are in suchbig demand and the pay is so large. Makes 4 hay 1 His “I was making $40 a week as Head Book- Kooper = when I took up your training. Last week [ made $175, in- cluding overtime and hardl. about $160. mechanics do the hard w Henry L, te Tenn. Makes $1,000a Month “I trained with you people 7 weeks, if you ne member; the started right to work with big gar- aqe. Aversges out $150 week. After 8 “weeks of this 1 opened a shop of my own. Sell a few batteries but make m big money on electrical re pairs. Find t EEL SD ected hie: ji easy to get any p I ch Clearing over $1, 000 a mo nth.’ freee W. C. Ellerd, Nebr. CGome to Chicago or Stay at Home For those who cannot come to Chi- cago I have prepared a home study course. Makes you as — as a resident course at easy a child can master. Learn in oe hours. Positively fascinating. ersonal coaching given by mail by the instructor to whom we assign you. Hundreds of our graduates are ‘home study’’ men and they are just as expert and their earn nes are as large as those who train Our free em- of such positions. You don’t need to know about Automobiles or Electricity at the start. Chicago. Nor do you need any more education than the ability to read simple We give you all the knowledge you need—teach you com- My book explains everything free. Amazing New Way to Train When the government needed Auto-Electrical Experts for the war there than handwo Men had to be trained 100% right and sent out The man who invented the 50 day method was the mar to whom Uncle Sam went for help. Results were amazing. Never before had such a thing been accomplished by anyone. English. pletely—in 50 days. was no time to waste. almost overnight. practical thorough trainmg in 50 days. 20 men to a class. more you learn, All my graduates are masters of their profession. I’ll give you their names. it is to get out of the grease. Unusual Short Time Offer I have a most remarkable offer to make for a short time to those who send for my free book at once. It will be a revelation to you. So be sure to mail the coupon at once, while this offer is in force. Write me personally. Cc. J. BUCKWALTER, President AMBU ENGINEERING INSTITUTE Dept. 41 2632 Prairie Avenue, CHICAGO So remarkable that after the war and at a great cost it was made available to Ambu students only. Ambu has even improved on the original plan by not admitting more than No other school does this and the smaller the class the Get Out of the Grease And they are so en- thusiastic over the way in which they’ve stepped from their former poor- pay jobs into this delightful, big-pay profession that I am glad to have They will tell you how fine poctsc--- FREE BOOK 22's" bout this new field. Shows why there is such a big demand for Auteemstive Elec- tricians apd why the pay is so large. Tells what our graduates are mak- ing and reprints copies of , own grateful letters. hows pe get paid for your head -3 rat rk. And how you can do the directing while others per- form the labor, and handle the dirt and grease. Get this remarkable book at once. A complete Cc. J. Buckwalter, Pres., Ambu En pncoring Institute, Dept. 41, 2632 Prairie , Chicago, lilinois | Please send me FREE Book and pce information about the 4 big-pay uncrowded field of Automotive EJectricity. xplain also your remarkable short time offer. os om interested in g Home Study Co ° Resident Gourse "at ¢ Chicago 5 DE bcs Koike pee 0-00 600000 00s0bate se bekasenseee i] BEOIEEDs c ccc cvccecssectceccceseeeenreee soputesese 4 Cs c-0:0 ccc Vibes cteespeocveueceeuwen Beebe. co ccvccic 5 Twentieth Century Book of Recipes, Formulas, and Processes This book of 800 pages, gives thou- sands of recipes for the manufacture of valuable articles for everyday use. Hints, helps, practical ideas and secret processes are revealed within its pages. It covers every branch of the useful arts and tells thousands of ways of making money. Cloth binding. Price, postpaid, $4.00. POPULAR SCIENCE MONTHLY 225 West 39th Street New York City lo talent or experience, necessary. ‘ascina’ work. P. lete instruction one :hie beat ie SeBsasees ‘Dept. 72,NewYork EARN MONEY /MMEDIATELY ~ WE FURNISH EQUIPMENT TO START THE STANDARD RADIO GUIDE Clear directions for making an excellent radio receiving set. Also for assembling and adjust- ing a set. Adequately illustrated. Price 50 cents. POPULAR SCIENCE MON TEES 225 West 39th Street New York City Eee OF

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oP AOR ES & Ba eee ey eee ee Ley: 3 A ee ee ‘ate ln para anes ae ae Sma ere pam (ow eee od a intense oe Doers ere oS Rei > 118 The only man who could talk to the Superintendent OON after I began studying,” a student wrote to us the other day, “we had a change in management at our plant. I certainly was glad then that I had decided to study in my spare time. For, thanks to my I. C. S. course, I was the only man in the organization who could talk to the Superintendent in his own language. As a result, I was promoted over men who had been here from ten to twenty years. My salary has been increased 90% in the last ten months.” HAT’S a true story of what just one I. C. S. student has done. There are thousands of others. Every mail brings letters from men and women telling of promotions and increases in salary due directly to spare-time study. One hour a day, spent with the I. C. S. in the quiet of your own home, will prepare you for suc- cess in the work you like best. Yes, it will! Put it up to us to prove it. Mail this coupon to-day. oe om he oe oe eee ee ee ee ee ee es ee are CORRESPONDENCE SCHOOLS x 7671C Scranton, Penna. Without cost or obligation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X: BUSINESS TRAINING COURSES Business Management Salesmanship Industrial Management Advertising Personnel Organization Better Letters Traffic Management Show Card Lettering Business Law Stenography and Typing Banking and Banking Law Business English Accountancy (including C.P.A.) (] Civil Service Cost Accounting Railway — ih Cheek, Bookkeeping Cc Sch ti Private Secretary High School “subjents Spanish 0 French Ulustrating TECHNICAL AND INDUSTRIAL COURSES Electrical Engineering Architect Electric Lighting Blue Print Reading Mechanical Engineer Contractor and Builder Mechanical Draftsman Architectural Draftsman Machine Shop Practice oncrete Builder Railroad Positions tructural Engineer Gas Engine Operating Chemistry © Pharmacy Civil Engineer Automobile Work Surveying and Mapping Airplane Engines Metallurgy O Mining Agriculture and Poultry Steam Engineering (1 Radio Mathematics Street 8-3-23 IN catechins con casedasocsitbucoxsscsesictsctnasecs cod bessccdccssensaunakice Persons residing in Canada should send this coupon to the International Correspondence Schools Canadian, Limited, Montreal, Canada me D) 8 BO) 6 ie WIRE HOOK, STAGGERED GRIP BELT LACING is replacing endless belts in hun- dreds of plants and saving Time, ihn | Labor, Belts, Power, Etele Ma Welelee-telen Money Write for Folder Detroit Belt Lacer Co. Detroit, Michigan Hh | Radio Phone Receiving 7,22! eek Written in non-technical terms by nine specialists. 224 pages. Fully illustrated. Price $1.50. Popular Scienee Monthly, 225 West 39th St. » NewYork | Contestants Name Useful Tools (Continued from page 81) covered about 20 miles when, owing to bad roads, I twisted my hub loose from the axle. I was driving along about 15 miles an hour, when all of a sudden my car stopped dead with the engine still running. After looking about for a few minutes, I saw that the driving axle on my left rear | wheel was just spinning round and round. For a while I thought I would have to leave other 15 miles. Then I thought of my pipe wrench. After a few minutes’ work I had tightened up well on my axle, having first removed the hub cap. I next roped the handle of the wrench to the spokes of the wheel, and this worked fine. In fact, I used the car in this way several days until a new hub could be shipped from a garage 40 miles away. So, on the whole, I think my pipe wrench is the most useful tool I have, although I will say that all of my tools are useful, From the large number of contributions re- ceived in this contest the judges have se- lected six others for honorable mention. They are the work of the following contes- tants: Raymond Paul, Chicago, Ill. (Pliers) _E. J. Morrissey, West Allis, Wis. (Caliper rule) Charles Vivier, Lankershim, Calif. (Pliers) Charles S. Murch, Augusta, Me. (Pliers) Frank G. Davis, Harrisonburg, Va. (Pocket knife) Mara Snerriov, Palo Alto, Calif. (Fora novelty contribution in the form of a neatly bound and illustrated booklet in verse, “The Song of the Hammer and Saw.”’’) Clamping Fixed RadioCondensers to Reduce Noise and Losses | gue experimenters often do not realize what heavy losses take place in their fixed condensers unless they are properly made. If the plates are loosely assembled and the tinfoil insecurely held, there will be a dilating effect caused by the repulsion and attraction of the electric currents and this causes many of the howls and noises heard in receivers. Those who make their own condensers will therefore do well to mount them be- tween two small clamping pieces of fiber or paraffined wood. . WOODEN--* a ry ~~ ' F CONDENSER A clamped condenser Staple Holds Wire to Iron Post N ADDITION to the two ways of fastening fence wires to iron posts illustrated recently in POPULAR SCIENCE MONTHLY, I have found the method illustrated is excellent. Itisa saving of time and material as one hole is drilled for each wire and ordirary staples are used as fasteners. The only trick is to drill the hole smaller than the wire to be held so that the staple points have to cross when driven in.—E. C. F. WIRE FENCE STAPLE my car on the desert and walk the | HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONT. HLY S ‘Gen : Here is the only liquid that will quickly and easily find all leaks anywhere in automobile cooling system and stop them permanently in from 5 to 10 minutes. RADIATOR NEVERLEAK is absolutely guaranteed not to impair or clog the cooling system inany way. It adds years to the life of your radiator by preventing rust and scale from forming. Radiator Neverleak is the original stop-leak compound. This, secret for- mula is the result of 25 years’ research. Entire satisfaction guaranteed or money re- funded. Write for free ‘Secret Service’ booklet. BUFFALO SPECIALTY MPANY oon Ellicott St. uffalo, Ic can make a good penman of you at your home during spare time, no matter where you live or how poorly you now write. My simplified system has shown thousands the way to good penmanship during the past twenty-five years—it CAN and WILL ae the same for YOU— “My beautifully y Vets: >, | illustrated 32-page "y y quate ol above pi below Book the wonderful improve- it I've made in less ¢ rove. ass | ‘How to Become Bonet Re 2 Gillespievitie,o. | a Good Penman” FREE!!! It contains many beautiful specimens of penmanship showing what others have accomplished by the Tam- blyn System, with testimonials and general information about our course—( Your name elegantly written on a card if you enclose stamp for postage) 5a athe sane as successfully as men AY, address kg Seabee Kansas City, Mo., U.S.A. 437 Ridge Bide. EARN $2,500 to $12, 000 A YEAR One student, no previous hotel experi- f ence, writes: “ef am leaving today to take } the fine position you secured for me at the Hotel * Another advanced ‘‘from clerk to executive two weeks after beginning this course, with over 100% increase in salary.’ MANY POSITIONS WAITING No hotel exbderience neces- sary. YOU can quickly fit yourself for well-paid hotel position, meals and often room furnished. Fascinating work. BIG opportunities. Men and women needed, specially trained for executive positions. YOU CAN EASILY PREPARE © Through the Hotel Operation and Man- agement Course, highly endorsed by hotel men. Prepare quickly at home in spare time. Simple—easy to understand. Cost moderate—terms easy. Hotels everywhere seek our graduates. Save this ad asa re- minder to write today for Booklet H-167. STANDARD BUSINESS TRAINING maettTeTE Carlton Court, Buffalo, N. $25. 00 in Prizes See top of page 6 in front of book for full details.

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i i Ne et an- tel are ost ere re- rp ITE | HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 119 Racing Skate Sail Provides Thrills and Is Fine Sport By Howard Greene NE of the finest and most-exhilarating of winter sports is skate-sailing. Nothing surpasses it in the sensation of pure speed. The skate-sail and the skater together form a miniature ice- yacht, capable of beating to windward and doing whatever an ice-yacht can do. This particular sail is designed to ‘“‘fit’’ a man or boy having a height of about 5 ft. 8 in. The sail itself is of heavy unbleached cotton. As the long upper spar, or sprit, will bend somewhat when in a wind, the head of the sail should be cut with a slight curve beginning about 6 ft. from the peak. The spreader, which holds the spars apart, and the short bar reaching from With the wind quartering, the skater can often travel faster than the wind the spreader to the sprit, are made in duplicate, a set on each side of the sail. The short bar rests on the shoulder, and this should bring the boom at the level of the ankles. Bear this in mind in as- sembling the sail. Make spreaders and shoulder bars of spruce 114 in. wide and 34 in. thick. The spreaders are to be planed to a half-round section, the flats next to the sail, while the shoulder bars are rounded to an oval section. The spars are hinged at B and the two spreaders at C (page 120) with a strip of leather secured by a wrapping of fishline or other strong twine. A -in. carriage bolt runs through both spreaders just far enough from the ends so that the boom can go between the bolt and the leather. Two collars, made of strips of leather wound around three or four times and held by glue and brads, are put on the boom to keep the spreaders from sliding fore or aft. The upper ends of the spreaders, which are left somewhat long to allow for the stretching of the sail, are drilled with several holes to take a similar bolt as at A. Each shoulder bar is pivoted to its spreader by means of a short \-in. bolt (Continued on page 120) The knowledge of science that has come to be so necessary a part of the education of the cultured man or woman. The understanding of the miracles going on around us that will bring every day some thrilling experience. The enjoyment of the most amazing romance in all the world—the story of man’s conquest of the Universe. This opportunity is now offered to you for the first time, and you may learn all about it in This Free Book which tells the whole remarkable story of an epoch-making work that opens the doors to the wonder-world of science. Without cost or obligation to you, we will send you a copy of this booklet, with four plates in full color and over thirty half-tone illustrations. You will find it a fascinating book in itself with full information about the most im- portant publishing event in many years.—The Outline of Science. The Most Fascinating Romance in the World The Outline of Science is the magic story that tens of thousands are eagerly reading— the story of man the miracle worker; whose marvelous scientific achievements have disclosed the most wonderful secrets ‘of nature and gained control over her greatest forces. In one simfle, flowing story you read of all scientific progress since the beginning—The Romance of the Heavens—The Story of Evolution—Man's Rise from His Earliest Ancestry—The Struggle for Existence—Mar- vels of the Insect World—The People of Air and Sea—The Kingdom of the Animals—Plant L ife—W onders of Microscopy —Miracles of Electricity—Psychoanalysis, Aviation, Wireless, Chemistry, and hundreds more subjects just as fascinating. It is all told so simply and clearly that anyone can understand—so fully and accurately that the whole scientific world has given it unqualified endorsement. Nearly a thousand superb illustrations form a pic- torial history of the progress of science. The Outline has been proclaimed by hundreds of au- thorities an unprecedented achievement. Thousands of reviews have been unani- mous in its praise. ‘Should be read by every human being,”’ says William Beebe, the famous scientist. “A fine triumph” agrees Vernon Kellogg. “Here are the foundations of our civilization,’’ writes Dr. Frank Crane. ‘‘More interesting to ar than any romance.’’— New York Globe. tensely absorbing narrative.’’ —Prov Side Journal. “An_ epoch-making _perform- ance.""— New York Herald. ‘Has no rivals. There is no other work in existence that presents all the sciences from the modern point of view in familiar language.’”’— The Bookman. Putnam’s The four handsome volumes of =} The Outline of Science form a 2 West ai ch z. romance of a thousand thrills New York that will hold you spell-bound for many an hour. And the free booklet will show you why. Send the Coupon’ Now No Obligation-No Expense for this booklet. You will find it highly interesting reading and it will give you full information about The Outline of Science and the easy way by which you may own and enjoy it. G. P. PUTNAM’S SONS Dept. 137, 2 West 45th Street, New York Send me by mail, without cost or obliga- tion on my part, the free booklet, with four color plates and over 30 half-tone illustrations, describing The Outline of Science. FSET ES OI REL, TEL ANN EDIE LED AE OI

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SUPREME COURT OF UNITED ae COURT OF APPEALS DISTRICT OF COLUMBIA, COURT DISTRICT OF CO) UMTED $1 Saves. COURT OF CLAIMS. saainen - - a - . rc , INSTITUTE ~. City Postal Clerks OCHESTE ~ Fill out and mail the attached coupon now. ROCHES ER, N. Y. Vacation with pay Permanent Employment Rapid Advancement Pleasant Work Short Hours You must act at once.

~ We will j = ‘ SRE SEr oP. ‘ igen ~ e will immediately send you full description of the positions obtainable sen owt ye tes any obll yi. with a full description of the work, hours, vacation and salaries. Boys peptic, on my part list of O. S. Government ~ 16 to 18 should get ready now for the first examination after the ig paid positions now obtainable. Advise me ~<a 18th birthday. 7 ~~._ DO IT TODAY. ~ also regarding the salaries, hours, work, vacation and tell me how I can geta position. TOMORROW RANI Bn.csveeiensuvissseinestogeesessseesecees sy. a ee ee

Skate-Sail Footsie Thrills (Continued from page 119) or a rivet. the end projecting through the nut and file off all sharp corners, to protect the sail. The sprit ends of the shoulder bars may be held in place by a strap, such as a skate strap, passing around both bars and the sprit. In using the sail, the first important thing is the balance—the pressure of the wind should be just a trifle greater be- hind the sailor than before. This balance | can be adjusted nicely by shifting the | shoulder bar forward or aft, as may be necessary, or by slightly tilting the boom, swinging the whole sail from the shoulder bar. If sailing a course that brings the wind on the right-hand side, put the sail on the right shoulder and grasp the sprit with the right hand and the spreader == SPREADERS

Dimensions of the skate-sail and details of the joints between the boom, sprit, and spreaders with the left, reaching back to do this. On the other tack, get on the other side of the sail and reverse, the left hand holding the sprit. In a heavy wind be careful not to slant the sail against the wind at too sharp an angle. The natural tendency is to do so, and it may result in the sail acting as a kite and slightly lifting the body, which results in a spill. Keep the sail approxi- mately vertical. One more caution. Do not make the first trial with this sail in a good breeze unless there is plenty of room. The be- ginner is likely to slide the sail too far forward and start shooting to leeward, directly before the wind, despite the “steering gear.”” The remedy is to slide the sail back until the prepanderance of pressure is aft. A fall on the ice, even at high speed, never does any harm, but running ashore is dangerous. Incidentally, if the wind gets on the wrong side of the sail, so that it tends to pull away, do not hold it by the shoulder bars or spreaders, but let it go; it will simply flop on the ice. In changing tacks, run up until the sail flaps in the wind and always go around forward of the sail, stepping over the point, If a bolt is used, trim down |

ay |

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| | B i ih New York Office Suite 1007 Woolworth Bldg. | j r Philadelphia, Pa., Office Suite 714-715 Liberty Bldg. a a ~ POPULAR SCIENCE MONTHLY TRADE-MARKS COPYRIGHTS NO CHARGE FOR Oo U = O ao - ae =" EXAMINATION AND # INSTRUCTIONS. HAVE YOU ANY NEW IDEAS?|h YOUR FIRST STEP | EFORE disclosing an invention the inventor should write | for our blank form **Record of Invention.’’ be signed and witnessed and returned to us together with model or sketch and description of the invention for examination and instructions. NO CHARGE FOR THE ABOVE INFORMATION Our Three Books Mailed Free to Inventors Our Illustrated Guide BOOK HOW TO OBTAIN A PATENT Full instructions regarding U.S. Patents. Our Methods, Terms, and 100 Mechani- cal Movements illustrated and described. OUR TRADE MARK BOOK Shows value and necessity of Trade Mark Protection. Information regarding Trade Marks and unfair competition in trade. OUR FOREIGN BOOK We have Direct Agencies in Foreign Countries, secure Foreign Patents in shortest time and lowest cost. ALL COMMUNICATIONS AND DATA STRICTLY CONFIDENTIAL INTERFERENCE AND INFRINGEMENT SUITS PROSECUTED Private Office, Victor J. Evans, with View of Patent Office Through Window , Highest References Washington, D. Victor Bldg. Prompt Attention VICTOR J. EVANS & CO., Patent Attorneys ! FREE COUPON Main Offices: 760-9th Street, N.W., Washington, D.C. J Gentlemen: Please send me FREE OF CHARGE your 1? books as described above. ] ee ee eeoeeeeeere Reasonable Terms 4 r i h ‘ t a f a i : 2 Ly i 1 4 1 i i ) l 1 i 1 1 t i a 1 i i ! t : L 121 This should — Chicago, Ill., Office | Suite 1114 Tacoma Bldg. “i Pittskurgh, Pa., Office Suite 514, Empire Bldg. ahh oe ee a Suite 1010 Hobart Bldg. Te tan GEES - wee " ee § ‘ cma 4 San Francisco, Cal., Office bon Late PRR LT TET 2 I ET OT SRT te RN

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sere r > . ee eee ie o 122 Dept H-175 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY COURSE IN TWO YEARS

YOU ARE BADLY if you lack HANDICAPPED FHighSchool P training. You cannot attain business or social prominence. You are barred from a successful business career, from the leading professions, from well- paid civil service jobs, from teaching and college entrance. In fact, em- ployers of practically all worth-while sitions demand High School train- ng. You can’t hope to succeed in the face of this handicap. But you can remove it. Let the American School help you. FIT YOURSELF FOR A BIG FUTURE This course, which has been prepared by some of America’s leading professors, will broaden your mind, and make you keen, alert and capable. It is com- plete, simplified and up-to-date. It covers all subjects given in a resident school and meets all requirements of a High School training. From the first lesson to the last you are care- fully examined and coached. USE SPARE TIMEONLY Most people idle away fifty hours a week. Probably you do. Use only one-fifth of your wasted hours for study and you can remove your present handicap within two years. You will enjoy the lessons and the knowledge you will gain will well repay the time spent in study. Check and mail the coupon NOW for full particulars and Free Bulletin, American School Dept. H-175 Drexel Ave. and 58th Sf., Chicade _. American School and how you will help me win success, sooves Building Contractor Automobile pacer pairman

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Tire-Repair Frame for Home Garage Aids in Patching Tubes | gpa toned punctured tubes becomes a simple matter when a rack is at hand for holding them properly. Such a rack can easily be made and will save the motorist considerable time and trouble. Nail two braces to the best lighted wall stud in the garage and fasten a small board on top of these as a table. This should be about 40 in. from the floor. A piece of

Iya SECTION A-A SPOOL-6"x2"s

% BOLT AND NUT DETAILOF _-% SPOOL AND SLOT

The patching of inner tubes is made easier by this table, which has an adjustable sliding spool for holding the rubber taut wood is then slotted to accommodate a 3%-in. bolt, counterslotted to take a %%- in. nut, and fastened to the stud below. The bolt holds a large spool 6 in. long and 2 in. in diameter, over which the tube is stretched tightly as shown. The punc- ture patch can then be applied quickly and easily, and clamped in place.—J. R.

Ventilated Metal Compartment Holds Muddy Tire Chains ligne is no suitable place in an auto- mobile for storing muddy tire chains. One can readily be provided, however, by fastening a metal box about 7 by 8 by 12 in. underneath the floor boards. Quarter-

IRON STRIP/ o@ hee” <3 “| His : lS COVER itll A\ Mi vy “ims @ 74 e e |. S a 7 ] FASTENING SCREWS a, FLOOR jj ripe BOARDS fe’ —=a * OF CAR y )), A CHAINS y Je fp ij? fp pe. % PUNCHED, ] 4," SHEET HOLES © IRON

An opening cut in the floor of the car gives access to this special compartment for holding tire chains inch holes are punched in the sides and bottom to allow free circulation of air to dry wet chains. A wooden cover with a metal edge as shown covers the top of the box, which is then hidden by the floor mat,

ND FOR THIS FORM DON’T LOSE YOUR RIGHTS TO PATENT PROTECTION Before disclosing your invention to anyone send for blank form ‘tEVIDENCE OF CON- CEPTION” to be signed and witnessed. | sample form together with printed instructions will show youjust how to work up your evi- dence and establish thesame before filing ap- plication for patent. As registered patent at- torneys we represent hundreds of inventors all over the United States and_Canada in thead- vancement of inventions. Ourschedule of fees willbe found reasonable. The form “Evidence of Conception,’ sample, instructions relating to obtaining of patents and schedule of fees sent upon request. Ask for them,—a post card will do. PATENTS AND 274 Ouray Bidg. WASHINGTON, D. C. Originators of forms “Evidence of Conception.”

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 Ricut Now. Your brainscan help. Send to- day for our great new k—‘*‘Invene tions and Trade Marks, Their Protection and Exploitation’® and learn more about making money from ideas than you ever knew before. It tells many things that are wanted, too. A pestal will do— It is free.

_We help our clients, without charge, to get the dollars out of their ideas—having facilities none others possess, PATENTS ADVERTISED For SALE FREE Advice free. ponent delay—get the In INVENTION And ei MANUFACTURING AMERICAN SUPPLEMENT. INDUSTRIES, INC. Published _ for ~ the man with fan idea. Send for free sample 201 Patent Dept. copy. One year's sub- WASHINGTON, D. C. eS] scription 50c.

As one of the oldest pat- ent firms in America we give inventors at lowest consistent charge, @ service noted for results, evidenced by many well known extraordinary value. Book, Patent-Sense, free. Lacey&Lacey, 648 F St.,Wash., D.C. Estab. 1869.

PATENTS TRADE-MARKS, COPYRIGHTS AND PATENT LITIGATION rite for advice instruc- tiens how to proceed, costs, etc. Hand Book with illustrations of 100 Mechanical Movements sent free on request. ALBERT E. DIETERICH Patent Lawyer and Solicitor Successor to Fred G. Dieterich & Co. 60 Ouray Bidg. WASHINGTON, D. C.

e. — meeenpad EE 4

Wi

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6 ee 8S Owe tt We feu VPPervrs a fl - Home Workshop , Chemistry Simple Formulas that Will Save Time and Money Al Mo) de ESONee. aluminum, and gold paints are finely powdered metals or alloys, which can be obtained in almost any hardware or paint store, mixed just be- fore use with a so-called banana oil— acetone, amyl acetate, and _ benzol mixed in equal quantities: To give body to this “‘oil,’”’ a few transparent celluloid chips are dissolved in the amyl acetate Cutting up clear sheet celluloid to make chips for thickening “banana oil” until a thick solution is obtained. This is then diluted with the other two liquids. RAIN spots on the ceiling can be removed with a little unslaked lime dissolved in alcohol (denatured alcohol can be used). The lime is thoroughly shaken up with the alcohol until it crumbles into a fine powder. This mixture is then brushed over the spots. When dry, the ceiling can be painted in the usual way. THE waxing of woodwork often engages the at- tention of the home’ worker. Only thor- oughly depend- able commer- cial waxes should be used and then ap- plied thinly and vigorously pol- ished with woolen cloth. _In its simplest way a wax for wood consists of nothing more than 2 parts of pure, white beeswax and 3 parts of Venice or well ozonized or oxidized yellow turpentine. Spirits of turpentine—which is always water white —cannot be used. A more solid wax mixture, especially adapted for floors, although it can be used for furniture, consists of a handful of beeswax, a 34-in. cube of rosin, and a teaspoonful of Venice turpentine. These are melted together over a small flame, and from 8 to 10 teaspoonfuls of ozonized or oxidized turpentine added. This type of wax must be left at least Overnight; better still for 24 hours, be- fore it is brushed and polished. As soon as the thin layer is hard, it is repolished with a brush. A soft woolen rag is used for obtaining a high polish in the final rub- down.—ERNEsT BADE, Ph.D. Venice turpentine PATENTS Seventy-six Years of Practice HE firm of Munn & Company filed its first application for a patent in 1846, and for seventy-six years has endeavored to keep pace with the inventive genius of the United States. An experience of many years is at your disposal. If you have an invention which you wish to patent, send your sketches or model together with a description of your device, explaining its operation, and you will receive prompt, courteous attention. Write for our Handbook on PATENTS A full and complete booklet on Patents, Designs, Trade- Marks, Foreign Patents, Copyrights, Labels and Patent Office Practice with an explanation about our methods, terms, etc. All communications strictly confidential Keepin touch with the inventions of the world byreading SCIENTIFIC AMERICAN .. The MONTHLY MAGAZINE with a special appeal to every man of inventive genius. Recent rulings of the Patent Office, descriptions of the latest patented inven- tions, legislation and court decisions affecting patents, are noted in this authoritative publication. MUNN & COMPANY Patent Attorneys 683 Woolworth Building, New York City Scientific American Bldg., Room 3, 625 F Street, Washington, D. C. 801-D, Tower Building, Chicago, III. 602 Hobart Bldg., San Francisco, Cal. aera marae sarees ARE IF YOU HAVE AN ATE NTS INVENTION and DESIRE TO LEARN HOW TO SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent free on request. Tells our Terms, Methods, etc. Send model or sketch and description of your inven- —e ee eee eee ee eee = = = tion and we will give our opinion NE ins cuhns rxvens caeennaneeeeee’ I as to its patentable nature. ee aes Seis i:RANDOLPH & CO. I deois ack chin' tee chie ae I «occa epee ak 130 F St., N. W. Washington, D. C. Ss pe gee EP ee

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a Sate Toe nese eerres 0 SaaS av 124 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY “lm Going to Make More Money!” “T’m tired working for a small salary. I know I have just as good a head on me as Fred Moore and Bob Roberts, for we used to work side by side. But they’ve gone far ahead of me. “Why? Because they saw the value of special training, and I didn’t. “But I know better now. If the International Correspondence Schools can raise the salaries of men like Fred Moore and Bob Roberts, they can raise mine, too! “If they have helped others to ad- vance, they can help me. To-day— right now—I’m going to send in this coupon and at least find out what the I. G§ Ss. . can d do for me.” sere emma eee re ” INTERNATIONAL CORRESPONDENCE SCHOOLS Box 7669-C, Seranton, Penna. Without cost or obligation on my part, please tell me how I can qualify for the position or in the subject before which I have marked an X: BUSINESS TRAINING COURSES Business Management Salesmanship Industrial Management Advertising Personnel Organization Better Letters Traffic Management Show Card Lettering usiness Law Stenography and Typing Banking and Banking Law Business English Accountancy (including C.P.A.) [] Civil Service Cost Accounting Railway Mail Crank, Bookkeeping Cc Schoo Private Secretary High School “Subjects Spanish O French Lilustrating TECHNICAL AND INDUSTRIAL COURSES Electrical Engineering Electric Lighting Mechanical Engineer Mechanical Draftsman Machine Shop Practice Railroad Positions Gas Engine Operating Architect Blue Print Reading Contractor and Builder Architectural Draftsman Concrete Builder Structural Engineer Chemistry ©) Pharmacy Civil Engineer Surveying and Mapping Metallurgy O Mining Steam Engineering [2 Radio Automobile na Airplane Engine Agriculture and Poultry Mathematics Street Occupation Persons residing in Canada should send this coupon to the Inter orr Schools Canadian, Limited, ‘Montreal, Canada ADD $5.00 a DAY to YOUR PROFITS with a TORIT ACETYLENE TORCH No. 13 For radiator repairing, general soldering, light braz- ing, heating, battery repairing, etc. Produces instant hot flame, works rapidly. Furnished with 4 different tips and soldering copper, enabling you to do a wider range of work. USES ACETYLENE « sone A A cplendid use for discarded auto acetylene tanks, any rs make the Torit No. 13 pay for Stecif ‘in a singled day. Torch ¥ with 4 different tips, so! — copper, 6 ft. tubing and connection for auto ace’ lene 7. 0 er How to Weather-Strip Your Doors and Windows By Dale R. Van Horn RATTLING window or door pro- claims fuel waste in winter. It is sound business economy to prevent this loss of heat by applying weather-strip or installing storm sash and doors. The latter are, of course, ideal, but when ex- pense must be considered, weather-strip will serve the same purpose to a degree and is much less costly. There are so many good weather-strips on the market that one cannot go far wrong. Each kind has certain advantages and disadvantages. The plain felt strips Fig. 1. Resivite felt weather-strip to stop the draft through a badly fitting lower sash (Fig. 1) are the cheapest and the easiest to put on. The ordinary wooden strips edged with rubber are almost as easily in- stalled and have the advantage of requir- ing only a few small brads to hold them in place instead of a large number of tacks. Metallic strips (usually zine with rubber inserts) are neat and quite satisfactory if well nailed. The elastic rubber strips and cushion felt strips are somewhat similar to the plain felt, but are more substantial. More elaborate weather-strips, with inter- locking members, are also obtainable, but usually require considerable work to in- stall. For doors, however, there is a spring brass type that is inconspicuous and easy to apply. The first step is to figure out how much weather-strip is required. To rattle the upper sash of a window when the sash catch is un- locked is the usual test for tightness. For each window that rattles, fig- ure on obtain- ing enough weather - strip to go around the upper sash —probably 8 or 9 ft. Unless the window fits very badly, it is not necessary Fig. 2. Nailing on a to use weather- wood and rubber strip strip on the lower sash. For each outer door that is not tight, figure on enough weather-strip to go all the way around. Suppose wooden strips have been ob- tained. Cut lengths to go around the upper sash of each window and nail the (Continued on page 125) Warren Radio L Cut Away to — Construction. RADIC Keep Your Set Small WARREN Radio Loop, the most com- pact loop aerial, will fit inside your cabinet, under a table, in almost any odd space. Remove the unsightly, dangerous, trouble- some, old-fashioned outside antenna. A Warren Radio Loop simplifies, increases efficiency, and makes your set more useful. A TYPE FOR EVERY SET Type-A-737 (300-700 meters) 6 inches square—non- ec: tee 2 poe are 10 Type-A-7236 (176-1009 meters) 6 inches oquare—nee- : - 2 Type-B-2537 (300; 700 meters) 18 inches square— on Type- neta 200-18, 000 meters) with honeycomb “coll unting, 18 inches square—dire $25 ie for Bulletin U-102 V-DE-CO RADIO MFG. CO. Dept. O, Asbury Park, N. J. To the Man With an Idea } I offer a most comprehensive, ex- perienced, efficient service for his prompt, legal protection and the f development of his proposition. Send sketch, or model and description, for advice as to cost, search through rior United States patents, etc. Pre- iminary advice gladly furnished with- out charge. My. experience and familiarity with various arts, frequently enable me to accurately advise clients as to prob- able patentability before they go to any expense. Booklet of valuable information and form for properly ban your idea, free on request. Write RICHARD B. OWEN Patent Lawyer 6 Owen xe » Washington,D.C, 2276-D Woo worth Building New York City PATENTS HIGHEST REFERENCES PROMPTNESS ‘ASSURED BEST RESULTS Send drawing or model for examination and report as to patentability WATSON E. COLEMAN, Patent Lawyer 624 F Street N. W., Washington, D. C. GROW TALLER! INCREASE YOUR HEIGHT Develop your Physical Beauty. Natural, simple Method. Will increase your height and improve our appearance. Write for Free klet. Dept. F. THE NATURAL METHOD BUREAU, Atlantic City, N. J. close do nt gethe half. plug screv rep half so th will — the old the ing do: the yd St. Paul Welding & Mfg. Co. 164 W. 3rd St. St. Paul, Minn.

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HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY 125

How to Weather-Strip (Continued from page 124) pieces on that part of the frame outside the sash known as the blind stop. Hold each piece firmly against the sash as you nail it, but don’t press so hard that the sash will not slide. The lower rail of the upper sash and the upper rail of the lower sash, often called meeting rails, should be drawn tightly together when the sash lock is closed. If they do not come to- gether, take off half of the lock, plug the old screw holes and replace that half of the lock so that the lock will draw the

Fig. 3. Enlarging the striking-plate mortise

rails together when fastened. The lower sash can now be made tight by prying off the inside stops, which are usu- ally about %

« 1 ¢ Fig. 4. Plugging by 1% agg % the old screw holes strips, pulling the nails through the back or cutting them off, and replacing the stops. Start nailing at the meeting rails, being sure the catch is locked, and leave between the stop and the sash a space equal to the thickness of a thin sheet of paper. This will allow the sash to slide and yet let in little air. Only if the lower sash is very loose is it necessary to put on weather-strip, which in that case is attached on the inside stops at the sides and along the stool at the bottom (Fig. 2). Felt strips are placed in the same way, and if necessary a piece (usually extra wide) can be tacked underneath the lower rail of the upper sash to insure tightness between the meeting rails. Before apply- ing the weather- strip to an out- side door, see if it rattles when shut. If it does} remove the striking-platein the door jamb, cut or chisel out a narrow sliver of wood from the slot, as illustrated in Fig. 3, plug the old screw holes with wood (Fig. 4), cut the plugs off flush, and replace the strik- ing-plate in its new position. If this is done properly, the door will close and yet there will be no play of the catch in the (Continued on page 126)

* Fig. 5. Applying brass strip to door jamb

That’s the Way To teeth you envy —Just combat the dingy film When you see glistening teeth—as you do everywhere now —remember how folks get them. Leading dentists the world over are urging a fight on film. Millions now em- ploy the method. And wherever you go you now see the results. If.you have not yet found that method, ask for this ten-day test. Why teeth discolor You feel on your teeth a viscous film. It clings to teeth, enters crevices and stays. If you leave that film, it becomes dis- colored by food or tobacco stains. Then it forms dingy coats. Tartar is based on film. That’s why teeth grow cloudy. Film also holds food substance which ferments and forms acid. It holds the acid in contact with the teeth to cause decay. Germs breed by millions in film. They cause many _ serious troubles, local and inter- to fight that film. It has found two film combatants. One acts to curdle film, one to remove it, and without any harmful scouring. Able authorities proved these methods effective. Then a new-type tooth paste was perfected to apply those methods daily. That tooth paste is called Pepsodent. Careful people of some fifty nations are em- ploying it today. Pepsodent does two other things which research proved essential. It multiplies the alkalinity of the saliva. That is there to neutralize mouth acids, the cause of tooth decay. It multiplies the starch digestant in the saliva. That is there to digest starch de- posits which may otherwise ferment and form acids. Send the coupon for a 10-Day Tube. Note how clean the teeth feel after using. Mark the absence of the viscous film. See how

nal. Thus film is the teeth’s chief enemy. Now easy to combat, Dental science, in late years, has learned how

Protect the Enamel Pepsodent disintegrates the film,.then removes it with an agent far softer than enamel. Never use a film combatant which contains harsh ¢rit. teeth whiten as the film coats disappear. You will know in a week what this way means, both to you and yours. Cut out coupon now.

Pepsadent _REG.U.S. The New-Day Dentifrice A scientific tooth paste based on modern research, now advised by leading dentists the world over.

Stop Using a Truss) (“g STUART'S PLAPAO- PADS are different from the truss, being mechanico- chemico applicators made eadhesive pu ly to hold the distended muscles securely in place. No stra buckles or spring attac —cannot slip, so cannot chafe or press agdinst the pubic bone. Thousands have successfully treated them- selves at home without Reduced

Feecsieait F ac-Simile hindrance from work—most Fac-Simile Gold Medal obstinate cases conquered. Grand Prix Soft as velvet—easy to apply—inexpensive. Awarded Gold Medal and Grand Prix. Process of recovery is natural, is aherwards | Corer use for tresses. We e it sendin; ria pao absolutely PrWrite name on Coupon and send TODAY: FREE Plapao Co., 790 Stuart Bldg., St. Louis, Mo.

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10-Day Tube Free” THE PEPSODENT COMPANY, Dept. 583, 1104 S. Wabash Ave., Chicago, III. Mail 10-Day Tube of Pepsodent to

7 Only one tube toa family. =

The Real Metal Solder in Paste Form

“SOLDERAL <sS — — ——i Introducing Our New iz SOLDERALL of Heayy Solid Brass indispensable in the Home,Garag - and to the Electrician. For solder - ing Radio, House Wiring, Jewelry ignition, Kitchen Utensils, etc. XK te

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126 HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY Easy to Play Easy to Pay Donald Clark, Soloist with the famous Paul Whiteman’s Orchestra Victor Resende Wai is by Paul | Sax Invent ae Perfected the Saxophone True-Tone Saxophone The Buescher a0P is so perfected and simpli- fied that it is the easiest of all musical instruments tolearn. It is the one instrument that everyone can lay—and it wholly satisfies that craving everybody has to personally produce music, With the aid of the first three lessons, which are sent free (upon request) with each new Saxophone, the scale can be mastered in an hour; in a few weeks you can be playing popular music. Practice is a pleasure because you learn so quickly. You can take your place in a band within 90 days, if you so desire. For Bands and Orchestras, for church, lodge and ochael musical affairs, for social and home en the Saxophone is the most ular instrument and one St the most beautiful. A good Saxophone player is always popu- lar socially and enjoys many opportunities to earn money. e et ney are always in demand for dance orches- tras. Every to have a Saxophone quartette or Try It in Your Own Home may order any Buescher Saxophone, Cornet, am yd Sembee or other Band or Orchestral Instrument and tr six oe in your own home, without obligation. Essy ae Ss may be = ry if preferred, oe ) eereapens tnterentes @ complete catalog will """Buescher-Grand Trumpet Especially easy to blow, with an improved bore and new pro- ate With the mute in, it lows so softly and 7 that practice never annoys. splendid home instrument. Free Saxophone Book We ave pared a very interesting book on the history velopment of the Saxophone, It tells which saxo- kes violin, cello and o— p Barts ts and many other | oped a would like to know Iso illustrates first lesson. Every music lover should have - copy. It is sent free on request. Just send your name for a copy. BUESCHER BAND INSTRUMENT CO. Everything in Band and Orchestra Instruments 3116 Buescher Block, Elkhart, Ind. Burscher Band Instrument Co. 3116 Buescher Block, Elkhart, Ind. Gontemnen: 1 am interested in the instrument checked below:

axophone........ Cornet........ Trombune. Trompet.......: 7 (fention any other instrument interested in) ain Name. Street Address Town EE |

How to Weather-Strip (Continued from page 125) striking-plate and the door will not settle. If the door then fits fairly tightly at both sides and the top, the only weather- strip necessary will be a wide piece on the bottom of the door placed on the side most convenient for opening the door. Use 1-in. brads or 1-in. No. 6 round head screws for fastening on the strip. In addi- tion, if necessary, fit weather-strip on both sides and the top of the door jamb on the outside so that they will press tightly against the door when it is closed and locked. For doors that are especially bad, nail strips of 4 by 1 in. wood (or regular door stops) around the jamb, after planing the edge of each so that it will fit tightly against the door. Weather-strip can be used on top of this if it seems necessary. An excellent weather-strip for doors is a spring brass strip that is applied right on the doorjamb, asshownin Fig. 5(page 125). These are the basic principles to ob- serve in applying weather-strip. They will make it easy for any home worker to weather-strip all the windows and outside doors of the home, no matter what variety of weather-strip is used.

Unique Lighting Circuit ‘‘Aerial’’ Requires no Special Plug ALLED upon to in- stall a_ radio outfit for lec- ture purposes within half an TINFOIL hour, a radio me expert found himself with- ae out a lighting circuit plug and Tinfoil wrapped around no opportunity an electric-light bulb to rig up an outside aerial of any kind. As a sub- stitute for a lighting plug, a sheet of tin- foil was wrapped around an electric-light bulb and connected with wire to the aerial binding post of the radio set. When the electric light was turned on, the radio set responded exceptionally well.

Universal Wire Terminal Speeds Radio and Electrical Work [THE quickly made wire terminal illus- trated has been found by the writer to be convenient in making electrical con- nections to binding posts of various kinds. Cut up several dozen lengths of good flexible wire and make twice as many of the small copper connectors shown. >» The connectors are fastened to the wires by being bent around and This quickly made soldered as_ indi- terminal fits any cated. Then a binding post small piece of No. 14 gage bare wire is soldered to each ter- minal so that it projects a trifle. The con- nectors will fit interchangeably into both standard types of screw binding posts, as well as spring binding posts.—C. F. , SOLDER

wiNnay” Ne? s

us fi; uum y HOES AGENTS 3%, GAN RSS Tilis GUARANTEED TO NEVER TARNISH For store fronts, office windows, Bank windows, Office Doors, Panels, Board Signs, Trucks, Auto- mobiles and Glass Signs of all kinds. Anyone can put them on and make money right from the start without previous ex- All you have to do is to show

perience. your samples; the letters are very attrac- tive and easy to sell. Letters costing 3%e sell for 25c. One agent says: ‘‘Your Letters are the best thing I have seen in years: I have made $125.00 the first week and still going strong.’’ Paul Clark says: ‘‘Smallest day $28.70.’ H. Gilder made $835.00 in six weeks, $60 to $200a Week GENERAL AGENTS— It is easy to appoint sub-agents for this line. | We pay you 20% cash commission on all orders we receive from local agents gee by you anywhere. We allow you; 50% discount on your own orders. You can sell to nearby trade or travel all over the country, as you please.

Large demand for window lettering everywhere. Write today for free sample, full particulars and liberal offer to general agents. AGN ie) Genuine Gold Leaf Letters}.

Metallic Letter Co., 433-AN. Clark St., Chicago

“DON'T SHOUT” “T hear you. I can hear now as well as anybody. ‘HOW?’ With THE MORLEY PHONE. I've a pair in my ears now, but they are invisible. I would not know I had them in, myself, only that I hear all right.” The Morley Phone for the DEAF is to the ears what glasses are to the eyes. Invisible, comfortable, weight-

if d harm! A adjust sand sold. Write for booklet and

it. Over one hundred thou- _ THE MORLEY CO., Dept. 797, 25 S. 15th Street, Philadelphia

EAxr HoMee you can make $15 to $60 weekly in your spare time writing show O canvassing or soliciting, We instruct you by our new simple Directograph ov ape supply you with work and pay you cash each week. Write today for full particulars and free booklet. WEST-ANGUS SHOW CARD* SERVICE LIMITED Authorized Capital $1,250,000.00 63 Colborne Building, Toronto, Can.

y mate, game cen eae sicand 3 tai e et Easil and se Teicned by mn, nope and vs rite for Free tr. Toile ah about ty

supplie Dept. |

Page 103

HOME WORKSHOP -DEPARTMENT OF POPULAR SCIENCE-MONTHLY

4 ra genuine UNDERWOOD Yes, quly $3 down puts this genuine standard Shipman -Ward Rebuilt Under- wood in your home. Then—small monthly payments, or if convenient yoo oe cash. Either way you get the wor typewriter at a big cash saving. WHY PAY RENTAL? Think of it! You pay little more than rental, and the machine is yours! we offer the same

three models of the Underwood writer : which are hee — and sold iteren nderwood H Company a &§ e only difference is that Shipman-W: am. are fe yp 4 on ' are oy like new by ex X- them from brand new mac 9 Vieibicn ial Ww =the FULL LINE. of typewriting is visible at re times. STANDARD 4-ROW SINGLE SHIFT KEY- BOARD. Two color ribbon, back spacer, stencil de- Ae vice, automatic ribbon reverse, tabulator, ete. 7 TEN DAYS’ FREE TRIAL s fe rself! typewriter ten ill ye. You, ou, murt be isan an or fet entire trans. , j cost you a penny. ; st ar St atteated ca and full il partieulars. 1X — fiow. : =FREE TRIAL COUPONsum Kk} Typewriter -Emporium int | MAN-WARD MFG. a 2141 Shipman Bldg., CHICAGO oa Send by return mail Bargain Offer No. 2141 de of a Standard Visible Writing Underwood. ae ‘ This is not an order and does not obligate re. me to buy. nd Name...... aie iaresace Misisip bse < sisieos cle sae go. PSEC GR Ren Bee Bis INGOs, < 6.00 040.0. 6s0e00.0es —— SREINNON «sie bas 01056-914:006-0 State OR SA SRN EH, A, ESE A BS

Receives 100 Miles or More Sendnameandaddress.

our Clear Shin. Your Skin Can Be Quickly Cleared of Pimples, Blackheads, Acne Eruptions on the face or body, Barbers Itch, ema, larged Pores and Oily or Shiny Skin. FREE Write tod for my y FREE POOELET, A CLEAR-TONE SEIN,” telling how cured myself after being afflicted 15 years. $1000 Cash says ! can clear your skin of the above blemishes. E.S. GIVENS, 153 Chemical Bidg., Kansas City, Mo.

Motorcycle Bargains SAVE 25% to 65% on Slightly Used and_ Rebuilt Otorcycles, Ace, Indian, Excelsior, Harley-Davidson, Cleveland, Side Cars, Johnson Motor Wheels, Evans Power Cycles, Bicycles. Send for ree Bargain Bulletin and Money Saving Message, listing hundreds of a ange bag used, rebuilt and new machines, supplies, accessories AMER ICAN MOTOR CYCLE Co. Dept. 126 2047 W. Chicago Ave. CHICAGO

|

Amusing Toy Chickens Peck Grain as Pendulum Swings i THIS amusing toy, four chickens, mounted around the edge of a fanlike wooden platform, move their heads up and down realistically as if pecking grain. Their movements are caused by a pendu- lum that is swung around in circles. Each chicken has an egg-shaped body carved from soft wood, with two wooden pegs for legs and a head and a tail cut from thin wood. The tail is fixed, but the head is pivoted freelyin a slot, asshown, and moved by a length of heavy thread or thin string. The strings from all the chickens are The chickens’ heads joined together, bob up and down and tied to a longer string, which has a wooden ball or other weight at the end. The whole toy is painted in gay colors, and grains of corn are painted on the center of the platform, or real grains are glued in place there.—JoHn F. Jos, New York. Keeping the Glue Brush Soft an best way to apply glue to small work is with a little brush, such as a mucilage brush. The trouble with this method usually is that after the brush has been used the first time, it is allowed to dry and harden. After that it is no ;--e BRUSH better than a ~e piece of wood. The harden- ing of the brush can be pre- vented by mak- ~ ing a brush- ‘+=-=-SOLDER holder from @ he brush holder is short length of soldered to the can brass tube, with one end plugged. It is soldered to the side of the tin glue can. Water is then placed in it, and the brush dropped in when not in use.- In this contamer the brush will keep soft and always be at hand. It pays to buy the larger sizes of cans of glue, and ordinarily such a can will last so long that the trouble of soldering on the tube is well worth while.

WATER °°" IN TUBE

Bumper for Home Garage A SIMPLE bumper for the rear wall of a home garage can be made by mounting a heavy plank on two old auto springs. A spring for this purpose may be obtained from a junk dealer and cut in half, one piece being bolted to the wall to support each end of the bumper. The plank can be padded with pieces cut from an old tire, or the edges my rounded.

EARLE E, LIEDERMAN as he is today START THE NEW YEAR RIGHT Will 1924 Bring Success or Failure? Right now is the time to decide. If you had started right one year ago you would be on the high road to success this very minute. Don’t let another year pass you by. It is within your power to make yourself just what you will. Make this day the beginning of a new life and a better one. I WILL GIVE YOU WEALTH— HEALTH and HAPPINESS T will transform that body of yours and make you physically perfect. I will make a real HE man out of you. I will build out your chest so that every breath means increased life, purifying your blcod and sending vim and vitality throughout your entire system. I will broaden your shoulders and give you the huge muscular arms and legs of the athlete. I will put pep in your old backbone and strengthen every vital organ within you. You will be just bub- bling over with life, having tlfe keen, alert brain, the bright, flashing eye and the spring and step of youth. You will be admired and sought after in both the social and business world. You will be a leader of men, and the good things of life will naturally come your way. I CHALLENGE THE WORLD If a man stood on the house-tops and shouted to the people that he was the strongest man on earth, it would avail him nothing. Someone would make him come down and prove it. But records speak for themselves. I will gladly show anyone personal letters from the leading strong men in the world today that my course is absolutely the best and the quickest to acquire physical perfection. Come on then and make me prove it—TI like it. I have the means of making you a perfect p nyces ‘specimen of manhood, of making you a successful leader of men. . You will be a credit to your communit 1 have done this for thousands of others. What I have done for them I will do for, you. I don’t care what your present condition is. The weaker you are, the more noticeable the results. Come on then, start the New Year right. Send for My New 64-Page Book ‘“‘“MUSCULAR DEVELOPMENT”’ It Is Free It contains forty-three full-page photographs of my- self and some of the many prize-winning paste I have trained. Some of these came to me as pitiful weaklings imploring me to help them. Look them over now u_will marvel at their present physiques. This ick will prove an impetus and a real inspiration to you. It will thrill you through and through. All I ask is 10 cents to cover the cost of wrapping and mailing and it is yours to keep. This will not obligate ou at all, but for the sake of your future health and happiness, do not put it off. Send today—right now, before you turn this page. EARLE E. LIEDERMAN Dept. 1301, 305 Broadway, New York City ee, OR AP A IY AER ER CE A TS CR SE een EARLE E. LIEDERMAN Dept. 1301, 305 Broadway, New York City Dear Sir: I enclose herewith ten cents, for which you are to send me, without any obligation on my part whatever, a copy of your latest book, ‘‘Muscular Development.” (Please write or print plainly. )

Page 104

4 |e | i A 128 Electrical Experts Eqmn’124030qDay Trained ‘Electrical Experts’’ are in great demand at the highest salaries, and the opportunities for advancement and a big success in this line are the greatest ever known. “Electrical Experts’’ can earn $70 to $200 a week. Fit yourself for one of these big paying positions. BE AN “ELECTRICAL EXPERT” Today even the ordinary electrician—the ‘‘screw driver” kind—is making money—big money. But it’s the trained man—the man who knows the whys and wherefores of eecteier—the ‘Electrical Expert’’—who is picked to the ordinary electricians—to boss the big jobs— the jobs that pay. $3,000 TO $10,000 A YEAR Get in line for one of these ‘‘big jobs’’ by enrolling now for my easily learned, quickly grasped, right-up-to-the- minute, Spare-Time "Home- -Study Course in Practical Electricity. AGE OR LACK OF EXPERIENCE NO DRAWBACK You don’t have to be a College man; you don’t have to be a High School Graduate. My course in Electricity is the most simple, thorough, and successful in existence and offers every man regardless of age, education, or pre- vious experience, the chance to become, in a very short oe. am ‘Electrical Expert,”” able to make $70 to $200 a week. i GIVE YOU A REAL TRAINING As Chief eer s of the Chicago Engineering Works, I know exactly the kind of training a man needs to get the best positions at the highest peg Hundreds of my students are now earning $3,500 to $10,000. Many are now successful ELECTRICAL CONTRACTORS. YOUR SUCCESS GUARANTEED So sure am I that you can learn electricity—so sure am I that after studying with me you can get into the “‘big money” class in electrical work, that I will guarantee under Bond to return every single penny paid me in tui- tion if, when you have finished my Course, you are not satisfied it was the best investment you ever “made. FREE—ELECTRICAL WORKING OUTFIT AND RADIO COURSE I give each student a Splendid Outfit of Electrical Tools, Materials and Measuring Instruments absolutely FREE. With me you do practical work right at the start—at home. You start right in after the first few lessons to WORK AT YOUR PROFESSION in a practical way. THIS OFFER INCLUDES ALSO A NEW COMPLETE RADIO COURSE— ALL FREE An up-to-the-minute Course in Wireless Telephony and Telegraphy given free with my great Electrical Course—two Courses for the price of one. Coupon brings particulars. GET STARTED NOW—MAIL COUPON I will send you a valuable book entitled ‘‘How to Become an Electrical Expert,’’ and full particulars of my free outfit if you will send this coupon now. L. L. COOKE, Chief Engineer, CHICAGO ENGINEERING WORKS Dept. 531 2150 Lawrence Ave. CHICAGO, U.S. A. CHIEF eee need COOKE “| hicago Engineer Wi Dept. $31, 21 2150 Lawrence Ave., CHICAGO, ILL. Dear Sir: You may send me entirely free and fully | pronett. a_copy of your book, ‘‘How to Become an | lectrical Expert,” and particulars about your Home Study Course in Electricity and Radio. l | Ee ee ennenecccrinasanesesseueeesbe | I iabialeitiincnatinxetnenicadienicccsnitnieiynl | | SS be eee on eee eee | HOME WORKSHOP DEPARTMENT OF POPULAR SCIENCE MONTHLY The Shipshape Home How to Do the Odd Jobs ‘ For general use around Using the house, it is advis- Hacksaws able to select hacksaw blades with 14 teeth an inch. Fine tooth blades are apt to break on thick metals because the teeth clog up. To obtain the best results, saw blades should be chosen for the material that is to be cut, and it will pay the home worker to keep on hand, beside 14-teeth blades, a blade or two of 24 teeth to the inch for sheet metal and tubing. So far as the frame is concerned, it is well to get one that is adjustable to blades of different lengths, and by all means a heavy frame. If it is inclined to bend in bi; Bi. use, the blade will buckle and break. The newer type of pistol-grip saw frame is especially good when heavy cutting and considerable work are to be done. The advantage of an adjustable handle is that the blade can be turned at right angles to the frame when cutting off long strips of metal. To cut sheet metal, use the saw at an angle of about 45 degrees to the work. There is then more surface to bear on and less danger of breaking out the teeth. Bear down only on the forward or cutting stroke and not too hard. On the return stroke, ease up until there is practically no pressure. The teeth will then not become dull so rapidly. By putting two or three blades in the frame alongside each other, a wide slot can be sawn.~-HEnry S. LARABY. To APPLY varnish with- out laps, runs, or streaks is not difficult if no attempt is made to cover a large surface at one time. Take advantage of the pan- els, board divisions, and other breaks to divide the varnishing into sections. Brush the varnish on the surface freely and quickly with the grain of the wood, then spread it in a thin film by “laying off’ the surface across the grain without refill- ing the brush, and finally remove any superfluous varnish and smooth out the surface with a few strokes made with the (Continued on page 129) Tricks in V arnishing The Three Best Radio Bargains All good dealers carry Murdock Radio Apparatus because it is standard the world over — made _ right — priced right. If your dealer cannot supply you, send your order direct. MURDOCK MURDOCK' HEADPHONES LOUDSPEAKER Willgive youbetter Absolutely com- satisfaction than plete. A clear phones costing more money and will last longer. Now priced at $4.00 and crystal sets.) $4.50 $5.00 NEW MURDOCK PLUG JACK You need one of these. It enables you to connect four pair of headphones at ~~ Bea Wm. J. Murdock Co. 345 Washington Ave., Chelsea, Mass. Sales Offices: Chicago and San Francisco STANDARD SINCE 1904 toned, practical loudspeaker at a very low price. You should have one. (Not suited to THE NEWEST SIMORE TOOL es Lightning-Change” Combination KNIFE and screwdriver -- a keen ateel knife blade, and two screwdriver blades in the handle — blades selected and pro- duced by gravity, the knife blade can never fold or turn and injure you, change blades in two seconds. This Combination KNIFE and screwdriver ba! = be sent you post pre for Bs $2.25, ta or money orang The only 225 tool of its kind, ideal for radio — fans, carpenters, motorists, PREPAID forhousehold use. Order TODAY. Dealers are invited to write for proposition on this and other Simore tools THE SIMON & SKIDMORE MFG. CO. Dept. 51 Santa Ana, Calif. Planning a NEW HOME? Let these Books be Guide. Beautiful ali- fornia Styles, with Pic- tures and Plans for all- climate homes. SPECIAL OFFER: Send $2.50 for any eo three Books and Gae rage Folder. 50 Money back tf not satisfied. 1 E. W. STILLWELL & CO., Architects, 109 Calif. Bldg., Los Angeles BURN YOUR NAME ON TOOLS ARKOGRAF pot pom Soe took from theft. write 3 any name,engra any design on metal with electricity like writing on paper with m or pencil. Complete outfit $3.50, pre- paid any wears. Interesting descripe tive circulars free Write t to-day. ents wanted. Arkograph Pen Co., 481-A East Couch St., Portland, Oregon Wrestling B Book FREE gt S ee: Learn to Coie fereges cad snd carn brs i- = “ye iui ae Cec 2 W. Send al Burns aie of Wrestling, 1781 Ramge Bidg., Omaha, Neb.

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Se me OP ER m- lear cal ave 1d to

The Shipshape Home (Continued from page 128) grain, keeping the brush fairly dry by wiping it on the varnish cup. Sandpaper each coat except the last with 00 paper rubbed with the grain just enough to remove the gloss. For a dull rubbed finish, rub the final coat with pumice-stone powder and oil on a piece of rubbing felt or a cloth pad, giving each part of the surface about six or eight strokes. For a highly polished finish, rub with pumice-stone powder and water and, a day or so later, with powdered rotten- stone and water.

THE backs of chairs often project backward farther than the legs. This results in the wall- paper and plaster being damaged whenever any one accidentally shoves a chair against the wall. In order to prevent this disfiguring of the walls, I installed in all the rooms of my house a guard rail made as follows: Place the chair-back about 1 in. from the wall and find the distance on the floor from the back legs to the baseboard. Then rip from a %-in. board a strip as wide as this distance and as long as the wall or partition. The edge to the front Chair Guard Rail

A wooden strip nailed to the floor around the baseboard serves as a chair rail may be rounded or left square and the piece can be nailed or screwed to the floor. The quarter-round molding usually used in the corner between the baseboard and the floor, which, of course, has to be taken up, can be replaced in the angle between the baseboard and the guard strip. Finish to match the rest of the trim.—HArRRY W. LEUTNER, Baltimore.

ANYONE who does his own house painting knows how unhandy a ladder is when used near windows or for work nearly out of reach. A simple ex- tension bracket for the top of the ladder built as shown is a great aid in such cases. It gives unusual freedom to the painter at the top of the ladder, since there are no rungs or uprights in his way and he can stand far enough from the wall to wield a brush effectively. The extension Painting Ladder

should be at lay least 4 ft. wide he and bolted to - ag the ladder. " ‘The extension bracket

SII See eseseseseaearaes ee OOOO OOOO heres that crane you built ? BS are that Crane you built yester- day?” asks the Meccano Boy’s friend. “Oh, that’s a Tower today,” he repfes, “It sounds peculiar but it’s quite true, for I build a new model every day with Meccano. I i use the same steel strips and girders, brass wheels and nuts and bolts to build this model of the Eiffel Tower. There’s wonderful fun in Meccano. You can build whatever you choose and there’s heaps of fun making your models work and then taking them to pieces to build something else. “It’s because all the parts are real engineering units that I can build anything an engineer builds. And it’s ever so simple—I only use this screwdriver.” MECCANO Engineering for Boys

Grand Prize Contest Ask your dealer for entry blanks, or write to us. Send For This New Meccano Book It describes Meccano and tells interest- ing things about model building. Every page a pleasure. Free. if you send names and addresses of yourself and three chums. Put No. 65 after your own name for reference.

MECCANO PRICES No. 00 builds 40 models - $1.00 No. 2 builds 163 models - $6.00 . 0 sie 70 * - 2.00 No, 2X with elec. motor - 8.50 No. 1 “106 - 3.00 No. 3 builds 207 models - 9.00 No. 1X with elec. motor - 5.00 and up to $40.00 MECCANO COMPANY, INC. Division K-1 Elizabeth, N. J. In Canada: Meccano Ltd., 11 Colborne St., Toronto

FOR Oe A i hh hh hh he he he he

Ot he he ca hae ac ce eae oe ee oe ee LASS PIN FREE CAT, GIVE NAME OF SCHOOL OR CLUBANDNUMBERINCLASS 2 5 A ' prep p 7 ene == —_ any ote ‘ ve) MRGS 2404 ters a igures, 1 or 2 colors ename Nay P, Silver plate, 25¢ ea , $2.50 doz. Sterling WW Ky silver,40Gea., $4.00 doz. Write for catalog 3409 of sterling and solid gold pins and rings. Bastian Bros. Co. 542 Bastian Bldg. , Rochester, N.Y. 3529

var Saat Ly

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Print Your Own cards, circulars, labels, tags, menus boo aper. ress arger o Pee: Pree CUTS EXPENSEIN HALF, “jae a Bt oa Sire fez ees” — eo. <—s ether, to use, printed

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Special 5 Size Tap and Die Set, Only $3.00 DIRECT FROM THE FACTORY TO YOU! Our tomob' our highly finished chestnut bo: woes t's tape sb aie Se #16, and 1-2), tn the S. A. E. ) yay ie stock yy EE ony ole ae as. same e e cept that thread ss. = creak. You arepurchasing s eplendidset atavery be, Send us your order at once and be one of our customers us slee send you one of our circulars our full Tools Let line of AWORCESTER STEEL PRODUCTS CO, Dept. M. 29 Union Street, Worcester, Mass. U, S. A.

Page 106

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seni en) 139

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POPULAR SCIENCE MONTHLY

Take the Brakes off Your Brain (Continued from page 32) others, that you must work in order to live. That the mind cannot spin out thought of itself, that it will act only in response to some external impetus, undoubtedly is the most significant fact shown by psychology in its practical application to the every-day man, and an understanding of this fact furnishes the key that will unlock the storehouse of the hidden powers of the mind. We do nothing—we do not even perform the workaday actions necessary to keep the breath of life in our bodies, except in response to some external stimulus—the press of necessity, the orders of our employers, something of that sort. Nature has recognized this inertia of humankind and has supplied us at birth with the means of performing, without the direction of the brain, the elementary actions necessary to living. Thus we breathe, swallow, and digest our food, send the blood coursing through our bodies, by what is known as reflex action—actions that are accomplished without interchange of messages between nerve centers, motor centers, and muscles. Don’t Wait for Necessity’s Prodding This is what governs most of the actions of the chimpanzee; why he can’t progress. But far too many of us go through life virtually letting our reflexes take care of us. We act only in response to the stimulus of necessity. We never seek a stimulus that will stir our minds into action, carrying us on to the heights of achievement where stand those whose success we envy and, excusing our own lethargy and laziness, attribute to luck. A few weeks ago I called at the office of a lawyer and found him in a most unhappy frame of mind. On his desk lay a great sheaf of unanswered corre- spondence. “T hate to write letters,’”’ he told me. “These have been accumulating for a week, and I’ve been putting off replying to them from day to day until now there are enough of them to overwhelm me. What am I to do?” This lawyer is a really eminent man, and his distress about what seemed to me to be a comparatively trivial matter quite amused me. Getting an Unpleasant Job Done “T don’t know what you can do,” I informed him, ‘‘except to buckle down and answer the letters. All of us have mental inhibitions; yours apparently take the form of a distaste for letter writing. This distaste places a brake on your brain when you approach that task. The task itself is not difficult, but you raise up difficulties—imaginary diffi- culties that become real—by brooding too much over your dislike for dictating letters. Undoubtedly you do really difficult and important work without trouble, because you concentrate on the (Continued on page 131) Wynn iit Exchange 22 21 Reliance Bide. TRIAL

ne : . J : Js The Aristocrat of Chocolates a selection of the most | frequently chosen of all | fine Bunte chocolates.

BUNTE BROTHERS * CHICAGO Have You An INVENTION? If so the WORLD PROGRESS will show you how to Protect and Profit From Your Ideas Sample copy free. One year *ssubscription $1.00. Send for free book, “WHAT TO INVENT” containing Suggestions to Inventors as to In- ventions Needed. We invite manufactvrers to address us regarding inventions they want. WORLD PROGRESS PUB. CO., INC. Reom 202 Victor Bidg. Washington, D. C. DON’T WEAR/ A TRUSS BE COMFORTABLE— pe Ag Fs invention ‘which gue rupture sufferers immediate re= ef. »* has no. obnoxious springs or ir oe ind

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Page 107

Take the Brakes off Your Brain (Continued from page 130) work itself, raising up no imaginary difficulties, but rather using your fac- ulties to remove the actual difficulties that the work contains. “Try this,” I suggested. ‘Classify your correspondence according to its importance. Begin by replying to the routine letters that require only routine answers. Then, by the time you reach the letters on which you must exert real thought, you probably will have acquired sufficient momentum to carry you through.” He told me later that he had taken my advice. He found that the method I had suggested of ‘“‘cranking up” his mind had banished the trouble his correspondence had given him previously. Why Amateurs Were Successful During the war, in the munition works at Watervliet, N. Y., I saw many young women of no previous training and of little mechanical skill performing the most intricate operations connected with the manufacture of firearms—work al- ways before done by experts after years of experience. That these girls, called from homes, stores, offices, and factories to aid in supplying the sudden need for huge quantities of arms, were able to per- form this intricate work satisfactorily was due entirely to the fact that they had not been informed that the tasks at which they were set were difficult. Had they been told that the work they were doing usually required years of practice, they would have become doubtful of their ability to perform it, and probably would have failed. As it was, they just took it as a routine task, and went ahead and did it. Psychological tests conducted by the army and navy showed indubitably that the average mental age of the officers selected from civil life during America’s part in the World War was about 18 years. Certainly one would say that boys of 18 would not be fit to command - troops in time of war. Yet under the leadership of these same officers the American forces carried on their share of the war with conspicuous success. Why? Because under the stress of war and the sudden responsibilities it brought them, these officers of 18 mental years quickly learned to use the mental powers that had been lying dormant while they had been carrying on the easy, even affairs of civil life. In other words, their brains received the necessary impetus from without. And they rose to their opportunities through the use of their brains, completing with success the most difficult job they ever had essayed. Napoleon’s Pride His Impetus The French Revolution gave Napoleon his chance.. Napoleon was a very small man. Indeed, people used to laugh at him because of his size, and, because he was sensitive, it hurt very much. In- (Continued on page 132) POPULAR SCIENCE MONTHLY | RADIO N the case of all living _ things the heartlis the most vital organ. Weaken, injure or destroy the heart and life is accordingly weakened, destroyed. In a radio receiving set the tube is analogous to the heart. Remove it entirely and the set will cease to function. Use an inferior tube and the results will be inefficient and generally not pleasing to listen to. In living things a perfect heart does not always in- sure a healthy y, but on the other hand it is in- dispensable. The same is true of the radio receiving set. It may be perfect in every detail but unless the best tubes are used the results will not be perfect. Cunningham Radio Tubes were developed in the great Research Laboratories of the General Electric CUNNINGHAM RADIO TUBES endangered or tery Det. and Amp. Special Bas: REE. can taydcenieco ee 6.50 ie yt 2-18- -08, C-301A—6 Volts %amp. Ampiities€6.00 a others issue C-299—3 Volts 06 amp. Dry Bat- and pending. Li- CS A ef eee censed for reer ry C-300—6 Volts as Content De- experimental’ an EE APE ae A Re pan entertainment use in C-11-—1.1 Volts .25 amp. Dry ao © radio communica- Cote Se oa Poacial Base 6-50 tome Office: 182 2nd St. 154 W. Lake St. 30 Chareh St San Francisco, Cal. 131 Co.,,and are now being made in that company’s modern and mammoth factories under the su- pervision of highly skilled engineers. Better tubes are not attainable. There is a model specially adapted to every set, every circuit and everv socket used today. Every radio dealer can supply you with Cunningham tubes. Buy them for replacements. Insist that they be included, when purchasing a new set—and you will know that your receiving set has a perfect heart. The care and operation of each model of Receiving Tube is fully extlained in our new 40-page “‘Radio Tube Data Book.” Copies may be obtained by sending ten cents to our San Francisco office. TUBES The Heart of your Receiving Set Patent Notice Cunningham tubes are covered pai- ents dated 11-7-05, tion. Any other use will be an infringe- N.Y. City = ment. hicago, lil. Manufacturer With National Distribution Wants More Local Representatives HE man we want is now employed, but finds it difficult to make both ends meet. Hefeels certain that there must be some way whereby he can better his condition, He may not bea salesman but he can talk convincingly on something he firmly believes in. He may not have much money but he is not broke. The man we are looking for is mechanically in- clined and willing to devote his spare time as a local manufacturer and representative for us— work that can be done at home which will pay a splendid profit and surely develop into a business which will justify giving it all his time. The OZARKA PLAN will give such a man more money, more independence and a real opportunity to build up a formanent. profit- able business of his own. is fully described in a large illustrated book—a FREE copy is yours for the asking. Unlike any book you ever read, the OZARKA PLAN is a true story of life, of men, of why they fail and how they succeed. It is founded on the principle that the world owes wae gd man a good living, a home of his own surplus for a rainy day. This book proves the reason why some men are millionaires and why others, by the sweat of their brow made them so. In territory not now covered the [right man is ee ae OZARKA PLAN may be the pets | in ar life, so in writing for the OZAR AN Book, tell us about yourself fully ao kee name of your county. OZARKA INC., 852 Washington Bivd. Chicago, til. DO YOU LIKE TO DRAW? CARTOONISTS TRAINED BY W. L. EVANS MAKE MONEY Some of the cleverest cartoonists are former students. They had no experience before enrolling, but worked at the lessons during their spare time and found CARTOONIST Evans’ MetHop “easy to learn’’ and are now.making good money. It is not hard to learn to draw originals when shown in a practical way. The School is recommended by well known cartoonists because they know the students are handled right. - If you like to draw and want to be able to sell your drawings, send a sample of your work (either a copy or an original) and let us see what you cando. We will send you the port- a "ed cartoons and full details about the school. The Course is NOT EXPENSIVE THE W. L. EVANS SCHOOL OF CARTOONING Leader Bidg., CLEVELAND, OHIO

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132 POPULAR SCIENCE MONTHLY

CONCERNING BURGESS BATTERIES The unique position of esteem and confidence occupied by Burgess Radio Batteries is a natural devel- opment of the conservative policy which has characterized the manu- facture, advertising and sale of Burgess products. Of interest, perhaps, to the thinking battery buyer is the fact that no Burgess product is ad- vertised or sold until its merit has been proven, not only by our own rigid tests, but also those of the foremost radio engineers, manufactur- ers and experimenters in the country. Through friendly criticism and suggestions, together with extensive research and engin- eering by the C. F. Burgess Laboratories the efficiency of Burgess Batteries has increased to a degree which we believe is not equalled elsewhere. Ask Any Radio Engineer BURGESS BATTERY COMPANY Encineers - DRY BATTERIES - MANUFACTURERS FLASHLIGHT - RADIO - IGNITION - TELEPHONE GENERAL SALES OFFICE: HARRIS TRUST BLDG., CHICAGO LABORATORIES AND WORKS: MADISON, WISCONSIN BRANCHES BOSTON KANSAS CITY PITTSBURGH ST.LOUIS IN CANADA PLANTS: NIAGARA FALLS AND WINNIPEG GRANCHES: TORONTO + MONTREAL + ST. JOH (on. BURGESS A | Garren MINNEAPOLIS NEW ORLEANS Wew YORK WASHINGTON on BURGESs .*) | js).

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Recover your old auto top frame yourself. $3. 85 Parcel Post Paid AND UP Custom tailor made to fit all makes and models of cars. Any person who can drive a car can put it on, Roof and quarters sewed together, with rear curtain, fasteners, welts and tacks complete. Give name, year and model num- ber of your car, and we will send you catalog with samples. Liberty Top & Tire Co., Dept. E-8, Cincinnati, 0.

Take the Brakes off Your Brain (Continued from page 131) stead, though, of bending humbly under the ridicule of his fellows, he was roused intensely by it. When opportunity came to him he gave the lie to the historians who were fond of saying that the world never again could produce another general as great as Caesar or Alexander. Nor is it necessary for a war or some other great emergency to arise to cause us to make use of the full powers of our minds. An American novelist whom some critics call our greatest spent his boyhood in luxury. There was no necessity of his using his mind for any other purpose than devising ways to enjoy himself. At the death of his father, he inherited a large sum of money, and went to Europe, when he gave himself over to the expensive amusements which the Continent provides for the wealthy idler. In a couple of years he had wasted his fortune and faced the necessity of work- ing or starving. In desperation he turned to his pen, and after a period of dis- couragement succeeded in catching the public fancy and winning both fame and wealth from his writings. In his case the necessity for supporting himself supplied the impetus which his mind required to stir it to action. Had the necessity not arisen, this man probably would have wasted his life. Poverty as a Brain Stimulus A famous financier of other days used to say that the best thing that could happen to a young man was that he should go in debt for some legitimate purpose. Similarly, a well-known jurist frequently expressed the opinion that the best environment in which a growing boy could be reared was one that placed him under the necessity of supporting a widowed mother. Both of these men were speaking from their own experience. To one the discharge of a debt that he contracted to launch his first business enterprise was the spur that drove him to make full use of his mind. To the other it was the necessity of supporting his mother. A large percentage of the successful men of this age were the sons of struggling country pastors. This is not surprising. Early in life these men received the stern impetus of necessity, which taught them to use all the powers of their minds. The habits of mind they acquired as boys remained with them through life, leading them to greater and greater achievements. Adversity Is a Great Teacher Most of us fear adversity. Yet adversity well may be considered a blessing in disguise, since to most of us it will prove the impetus we need to start our minds working to their full capacity. Francois Coppée, the distinguished French writer, in one of his books, tells the story of a banker who failed, and in doing so ruined a half-dozen persons who had intrusted their money to him. Flee- (Continued on page 133) YOU TOO. CAN PLAY THE HAWAIIAN GUITAR © : JUST AS THE HAWAIIANS 00! PLAY ALE THE LATEST HITS After Your FIRST LESSON You ~- ,<\__ Will Play a Complete Selec- ; tion. We Guarantee That-- Our method is so simple, interesting and appealing that you begin in your first lesson to learn the famous Ha- — waiian FolkSong**‘ ALOHA’’. Think Z4¢838 how happy you will be when you < surprise your friends by playing os the fascinating Hawaiian Guitar. Only Four Motions-- and You Master Them Quickly! In a few minntes you acquire the fou r motions necessary to pla: buses | Pa pn -after that ashort period of practice and you will pase master: is weird! tee music, Complete course of 62 lessons includes FREB beautiful Hawaiian Guitar, necessary picks, steel bar, etc. Noexiras. No Sretens Musical Knowledge Neces: never read a musical note in your life--if TE zpane knowledge of music a can quickly re to pla this wonderfully popular instrumen pea er’’ when vou can be the center of in: Over 40,000 successful students. Just Mail a Post Card for Details of our remarkable FREE Hawaiian Guitar Of- fer- pao write: ‘*] am interested’’-- but do it ioday.

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be grec CAN make $1 to $2 an hour writing show cards at home in your spare time. Quickl and easily learned by our new simple saoubods No canvassing or soliciting. Weshow you how, guarantee you work at homeno matter where you live and Book you casheach week. Full par- Goulers anes me! free. Write to-da D SYSTEM LTD. te et Be trully Paid 7, $1,000, a 206 Adams Bidg oronto, Canada Ford Runs 57 Miles on Gallon of Gasoline A new automatic and self-regulating device has been invented by John A. Stransky, 2041 Fourth St,, Pukwana, South Dakota, with which automobiles have made from 40 to 57 miles on a gallon of gasoline. It removes all carbon and prevents spark plug trouble and overheating. It can be installed by anyone in five minutes. Mr. Stransky wants agents and is willing to send a sample at

his own risk. Write him today.—Adv.

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For All Batteries The one charger which re- charges all radio storage bat- teries—2-volt peanut tube batteries, 6-volt A Batteries, 6 and 12-volt automobile bat- teries, and 1 to 4 B Batteries. It’s the new Valley Type A BC Battery Charger. Plugs into regular electric light sockets. Takes about a dime’s worth of current for an average charge. A lot of people were dissappointed last year because we could not make enough Valley Chargers. We are making more this year, but with the improvements, they will be in greater demand. Don’t miss out. At all good radio dealers. VALLEY ELECTRIC CO. 3157 S. Kingshighway, St. Louis, Mo. POPULAR SCIENCE MONTHLY 133 ACE TYPE WV *20~ Armstrong Regenerative Receiver Licensed under ArmstrongU.S. Patent No. 1,113,149 The low cost of this set together with its efficiency and simplicity makes the great de- mand for it increase daily. A long range re- ceiver. Stations from coast to coast heard dis- tinctly. An ace two-step amplifier in connec- tion with this set at $20.00 makes use of loud speaker practical. Has Crosley Multistat which permits use of any make tube. Ask for “Simplicity of Radio” —it’s FREE. Dealers, write on your letterhead for splendid sales proposition. ; THE PRECISION EQUIPMENT COMPANY Powel Crosley Jr., Pres. 117 Vandalia Avenue CINCINNATI, OHIO Re/ieve your trouble zone, / THE NOSE AND THROAT NS couen tatps @ FREE RADIO BOO An easily understood explanation of Radio written by Powel Crosley,Jr., President of Crosley Mfg. Co., Cincinnati, and The Precision Equipment Co., Cincinnati. Write today for this Booklet. CROSLEY MANUFACTURING CO. 117 Alfred St. Cincinnati, O. Take the Brakes off Your Brain (Continued from page 132) ing the country, he went to Canada, where in time he recouped his fortunes. Then it occurred to him that he should return to his native land to repair the harm he had done those who had suffered through his reverses. What was his surprise to find all of them far better off than they had been in the days before his failure. Adversity, the press of necessity, had supplied them with the mental impetus they needed to carry them on to success through their own efforts. This is a purely fictional story, but it is founded on a premise which psy- chology shows to be entirely true. Ad- versity, crises, sudden _ responsibility, almost invariably drive men to achieve- ments beyond any they have dreamed. We see evidence of this about us con- stantly. The young man who starts a business enterprise on small capital will learn to work harder, to use his mind more than will a salaried employee, and his efforts will carry him on to success. Find Your Own Brain Stimuli A man suddenly advanced to a position of greater responsibility in the business world will rise to his new responsibilities, evidencing capacity for work and mental effort such as his fellows had not suspected he possessed. New business, the more responsible job, the sudden necessity for supporting a family supplies the impetus that the mind requires. Too many of us, lacking such re- sponsibilities, crises,*or the spur of necessity, potter through life, using our minds no more than we have to, satisfied as long as we are supplied with the bare necessities of existence. Through psy- chology we learn that the mind will not work except in response to an impetus from without; yet how many of us, if that impetus is not supplied by circum- stances, try to supply it ourselves? That we can supply it, psychology also shows. We learn that while the mind, like the automobile, requires a crank to start it, yet once started, we can through our will guide it along whatever paths of thought we wish. Envy or Emulation ? An order from your employer will start the engine of your mind working. Yet the direction in which your mind will travel after receiving that order rests entirely with you. You may grumble at the extra work you have been asked to do. You may even, if you wish, flatly refuse to do it. Or you may—and you probably will, if you are wise—accept the order cheerfully and throttle your mental engine up to full speed to accomplish the task to the best of your ability. Like- wise, the success of another will stimulate your mind into activity, but it rests with you whether that activity will take the form of envy and jealousy of him and complaint at your own lesser fortune, or the desire to emulate him and achieve success similar to his. (Continued on page 134) The Opinion of 1,000 Others To find out what influences ambitious men and women to enroll with the American School, an advertising agency sent out a questionnaire to one thousand names, taken at random from ourstudent rolls. The answers to three of these questions show very clearly how our School is regarded by our students, both before and after enrolling. Why Students Inquired About ur Courses 31.5% wrote only to the American School, be- cause our,advertisements impressed them more favorably than the advertisements of other home study schools. 27.0% had heard of the American School before. 23.7% answered several home study school ad- vertisements, so they could select the best. 15.1% were recommended to our school by a friend or acquaintance who had taken one of our courses. 2.7% inquired for various other reasons. Why Students Considered Taking a Course With Us 334% wanted to qualify for better positions. 22.5% wanted assistance in their present work. 20.7% wanted more information on the subject for which they enrolled. 1.2% wanted to prepare for college entrance examinations. 7.4% wanted to “brush up” on subjects previ- ously studied. 8% enrolled for various other purposes. What Students Really Think About Our Courses 97.2% say our courses are ‘‘Good.” 1.4% say our courses are only “Fair.” rd ead our courses are “‘Not what they ex- When you take the average opinion of 1,000 people, selected at random, about some one t! . you will act a definite idea as to the worth of the thing. average opinion of these 1,000 le is that our courses are O. K. Do you need arther proof? If you want to get ahead and are consider- ing a course of practical training, you will find that hool is the best place to get that the best grade of the American training. From us you will get training at the lowest cost. And further— Our Money-Back Guarantee Protects You You cannot lose when you enroll with us. If after you have $ finished your course oo ee ou are not absolute- y satisfied, if you do not believe that the training we gave you will help you to get ahead, just write us and we will refund to you every cent you paid us. Mark the coupon, Your re- quest for information puts you under no obligation and _ no GENTS WILL BOTHER YOU. American School The American School is not @ money-making cor- poration, but like resident schools colleges, is chartered strictly as aa **Educational Institution, not for profit.” ore than 200 famous engineers and educators prepared the special in- struction papers for our -etudents. For overa quarter of a . century, Big Bagom, American Educators and usiness Men have recommended School the American School. The know that our long nd Dept. G-175 ence as an educatio in- - G-17 stitution guarantees better exel Ave. and | training at. less cost than 58th St. can be given by any school Chicago, U.S. A conducted for profit. COURSES TAUGHT American School, Dept. G~175, Drexel Ave.& 58th St., Chicago. Gentlemen: Please send me full information on the subject checked. It is understood that this request places me under no obligation and that no agents will bother me. . Architect . -Building Contractor@r Carpenter .- Automobile Engineer . Automobile Repairman . .Civil Engineer . Advertising Manager .- Business Manager . -Financial Manager .-Sales Manager . Cert. Pub. Accountant .. Accountant & Auditor ..Law . . . Machine Shop Practice .-Photoplay Writer ..Mechanical Engineer .-Shop Superintendent .-Employment Manager . Steam Engineer . .Foremanship .- Sanitary Engineer . Surveyor (& Mapping) .- Telephone Engineer - Telegraph Engineer chool . .Bookkeeper . High S .- Draftsman & Designer ..Fire Insurance Expert . -Electrical Engineer . .Wireless-Radio . General Education a w .- Personal Analysis ..- Undecided GUND ioe bi Wa dee nd desbebbcbbduccoasdéccnmel é CORI ois on Cece Kivne toh nceecksrdaadicc ee eee

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pee Lane: 235 Fy Say mrt a nts sar Ov attache Mae mi ae = 7: sacs. San = = Sas ina Re © eho Fae. wes 134 POPULAR SCIENCE MONTHLY He took the world to her Twenty-five years ago a boy left a little country town to find his fortune. He found it. The modern vacuum Two years ago, when radio was still a novelty, he took a receiving set back to the old home and set it up in his ? ° tube, used in radio mother’s room. That evening transmission and = the world spoke to her. reception and in so many other fields, is a product of the Re- She could not follow her boy search Laboratories of dies Generel Eloc- away from home. But the tric C . Th . Laboratories arecon- DESt that the world has to give stantlyworkingtode- =§ __in music, in lectures, in ser- velop and broaden the service of radio. mons—he took back to her. GENERAL ELECTRIC CATALOG #35 EVERYTHING IN RADIO One of the largest complete stocks in the world. 40 diagrams of latest Hookups. DEALERS ALL OVER THE U.S. Making big profits handling our supplies. 24-hour servi shipped same day order received. WHOLESALE RADIO DISTRIBUTORS Dept.B 6W. 14thSt. SENSATIONAL SALE GUARANTEED TYPEWRITERS Limited quantity fully guaranteed standard make typewriters. Five Days Free 7. Lowest prices ever offered. monthly pay- ments, Satg: we As for FREE booklet of Valuable Typewriter Information and Special Sale Bulletin. SMITH TYPEWRITER SALES CO. 321-360 E. Grand Ave. Chicago, Il. Kansas City, Mo. “LIGHTING FIXTURES” Ready to hang. Direct from manufacturers. Completely wired including glassware. Send for Catalogue No. 24 and ‘ Dealers’ proposition. ‘Ea ERIE FIXTURE SUPPLY CO. ’ Desk A, Erie, Pa. Take the Brakes off Your Brain (Continued from page 133) It is a striking, but true, expression that the ordinary graduate of a high school in our time knows much more about a great many things than Aristotle, the wisest of men in his day, ever knew about them. But it was not Aristotle’s knowledge that gained him his reputation as the greatest of thinkers—the sovereign of men who know—it was his power to use his information to the best advantage in thinking out the problems that lay all around him. How the old Greek philosopher, who was deeply interested in psychology, would have envied us our knowledge of the make-up of the nervous system and of its mode of action as far as that has gone! And yet we, to whom this knowledge is readily available, make scant use of it, plodding along in the old-fashioned way, letting our instincts and the practice of whatever talents that are forced on us carry us through life. What is it that has put a brake on your brain? Whence springs the inhibitions that are holding you back? From lazi- ness? From ill temper? From self- satisfaction? From grumbling discon- tent? From lack of self-confidence? Look within yourself for the answer, and see that you give it truthfully. Once conscious of the thing that is impeding you, you have gone a long way toward banishing it. This you can do by calling on your will. Recognizing your trouble and using your will to combat it, supplies the impetus your mind needs to start it working toward its full capacity. It All Rests With You And once started, its own momentum will carry it forward. Then difficult tasks will become simple and what had seemed impossible of accomplishment before will become relatively easy. It all rests with you. Once you make up your mind to do a thing you will find you have the mental equipment with which to do it. You will find that you have hidden resources of power which you never suspected and these latenf powers will carry you far on the road of success and happiness. . But making up our minds emphati- cally enough to stir ourselves into action is something that too few of us do. In- stead, we let ourselves be guided by our sensations. We are ruled by our senses, while our will power lies dor- mant. Were we to awaken it, we should be able to accomplish ever so much more than we can ever be tempted to do by our senses. There lies the difference between the unsuccessful man and the successful one— in the use of the will. Buy the senses operate, how they y be made to serve us in drawing on ey Mi hidden resources of our won- derful mental storehouse will be de- scribed by Doctor Walsh in the next article of this series.

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Here Are Correct Answers to Questions on page 71 1. It is probably because waste materials of various kinds accumulate in the body in such a way that they cannot be got rid of. For instance, compounds of lime get deposited in the walls of the arteries so that the walls become hard and brittle. We know very little as to why all this happens. 2. It is mainly a difference in the impuri- ties. Hard coal is more nearly pure carbon. Both hard coal and soft coal have been formed by the slow hardening of vegetable matter buried in the rocks. The hard coal has hardened more completely. A larger percentage of its original im- purities has been got rid of. 3. Light. It travels 186,326 miles a second—more than seven times the cir- cumference of the earth. 4. As the earth turns from west to east, and as London is east of New York, the sun rises in London while New York is still dark. 5. The millions of little crystals of ice that are formed all through the ice cream must be kept small or the cream will not be smooth. The stirring helps to keep these crystals small. 6. This is a form of hypnotism, you your- self being both hypnotist and subject. Suppose you are climbing down a ladder out of a burning building. Your attention is fixed completely on the fire and on the progress you are making in your escape. You have no brain power left to notice anything else. 7. Remember that a glass prism will split light into the seven primary colors. A group of falling drops of water will do the same thing. If the sun shines on such a cloud of falling water drops, as in a shower of rain, the light reflected from the drops will be split up in this way and a rainbow results. 8. Only if you could get a machine that would run with absolutely no friction or other resistance. No such machine has ever been made. Evenif it could be made, you would not be able to get power from it. Any attempt to do so would stop it. 9. The poorest conductor of heat is a vacuum. The only heat that will pass through it at all is the kind of heat called radiant heat, such as that received from the sun. Vacuum bottles are double, one bottle inside the other. The space be- tween them is a vacuum. 10. Small ones have been made by dis- solving carbon in melted iron and allowing it to crystallize as the melted iron cools very slowly and under pressure. No one has succeeded in making large diamonds. 11. Woolen cloth is made of many tiny fibers twisted together to make threads and then woven. When the fibers are wet, they twist up more and this makes the threads shorter. 12. Scientists believe that the animal an- cestors of man were hairy all over like an ape. Man gradually is losing his hair, probably as a result of wearing clothes, so that hair on the body is no longer neces- sary as a protection. Clothes were in- vented before hats. So the head hair has not been lost as completely as the hair elsewhere. POPULAR SCIENCE MONTHLY 135 , TRADE MARK REG. URLIIZE “SUPREMACY IN. 7 MUSICAL INSTRUMENTS ¥ Learn to Play = You are always popular and sure of a good E 4 time if you can play some musical instru- = ment. By yourself, with your friends around the piano, in orchestras or bands,—there is no end to the pleasure music will give you. And there is no easier way to earn money in your spare time. = in Your Own Home You may now have any known musical instrument for a week’s free trial in your own home, There is no obligation to buy—no expense for the trial. You may return the instrument at the end of a week if you decide not to keep it. Wurlitzer instruments are known everywhere for their unusual tone quality and excellence of workmanship. They are used by the greatest professional musicians, bands and orchestras. Harry L. Jacobs of Sousa’s Band, Brooke’s Marine Band, and Chicago Grand Opera says: “I am proud to be the owner of one of your new cornets. It is positively superior to anything I have had in all my years of cornet playing.” Thousands of amateur musicians are playing on Wurlitzer in- struments. Many of them could not have bought except through the Wurlitzer selling plan. Easy Payments The Wurlitzer plan makes it easy for you to own the instrument you want. Payments are conveniently arranged in small monthly sums—a iew cents a = will pay. ; Wurlitzer isthe world’s greatest music house, with storesanddealersinallparts of the country. But no matter where you live you will receive the same service by mail as though your lived next door tothe factory. Send the coupon today, ‘ Free Catalog The test musical catalog ever published. Over 3,000 coliduaoaee: known instrument described and illustrated PF py Aa them shown in full color. Gives you all details of the Wurlitzer plan. Send coupon now. f The Rudolph Wurlitzer Co., Dept. 1781 117 E, 4th St., Cincinnati 329S. Wabash Ave., Chicago 120W.42ndSt.,NewYork 250Stockton St.,San Francisco Send absolutely f: illustrated catalog of musical Snotrwenente. Also tell. me how I may try any instrument in my ow , own home at ycur expense and urlitzer plan makes it easy for me to buy. No WErTTeTITITi TT tities i) Peer erer Terre TRETeTOTITICCT retiree

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POPULAR SCIENCE MONTHLY Discovers NewCheap Fuel | Does Away With DirtyCoalandWood | in Ranges,Heaters Furnaces! Mr. B, M. Oliver, fuel expert of St. Louis, after seventeen years of experimenting, has de- veloped a new cheap fuel which gives 3 times the heat of coal. 3 Times th No more fires to build, bank or watch—no more dirty, heavy coal to atry and lift—no more clouds of ashes to breathe, or back-breaking scuttles toempty—no getting up on cold mornings to build fires—no more smoke, soot and coal dust—no more worries about coal short- ages, poor quality or high prices since this Wonderful New Invention. heat of coal or wood. Cheap—fool-proof— absolutely safe—lasts a_ lifetime—150,000 now in use! No wonder housewives are clamoring for this wonderful new device. Mrs. W. N. Spencer of Connecticut writes: “The Oliver in my heating stove works like magic. It is wonderful to have quick heat and no work.’’ Mr. Geo. Flynn DER TEI + ns . ‘ : of Michigan writes: “It is HY should any woman give her best strength in endless, back-breaking servitude to a hot, mussy heater, cook stove or furnace? The wonderful in- vention of Mr. Oliver of St. Louis in one minute turns any coal or wood burner into a modern up-to-date gas stove. It gives as much or little heat as wanted by simply turning a valve! Slips right into any. fur- nace without change. 3 times the heat of coal, No motors, gas or elec- tricity. . i Cheaper Than Coal or Wood Mr. Oliver calls his invention the Oliver Oil-Gas Burner, be- cause it uses 95% air and only 5% oil, the cheapest fuel there is, turning them into actual gas that burns with an in- tensely hot, clean flame. No wicks, no smoke, no odor. 16 Models to Fit Any -DISTRIBUTORS Salesmen and Agents Wanted Here is your opportunity to “cash in” on this nation-wide sweep of oil. Housewives everywhere are clamoring for this amazing new Burner. Oliver agents are making fortunes. F. W. Bentley of Phila. says: ‘‘Ye Gods, some seller. made $215 today.’” J. Carnegey, S. Dakota, writes: ‘‘Making $1000 a month.” Mrs. Ider, Kans. made $100 a month spare time only in her own home. I want men and women of every type—for spare time or full time work. $75 a week easy! Man getting $1000 a month. Men with selling organizations who can swing whole territory can earn cleaner, cheaper, hotter and steadier than coal or wood. Cost me $5.00 for two months.” Low Introductory Price Now, once and for all time do away with household dirt and drudgery. Send immediately for the FREE ATTRACTIVE BOOKLET, “New Kind of Heat,” telling all about this amazing new invention. Shows The Oliver Burner makes any range a gas stove. No holes to drill, no bolts to fasten. Easily slipped in—in one minute, $10,000 to $50,000 or more a year. Write or wire at once for details or exactly how it works, how it is different from all other burners, how it will relieve es YOU Of the back-breaking work of coal and wood. Mail Coupon for Big Offer If you mail the coupon at once you will be in time to receive Mr. Oliver’s very Low In- troductory Price. But to get this low price you must write at once. There is no obliga- Stove or Furnace Made in 16 different models to. appointment. Address me_per- fit any kind of cook stove, heat- _fonally. B. M. Oliver, at address ing- stove or steam, hot water, or hot air furnace. No noisy motors, no gas or electrical connections, no moving parts, and installation can be made with no changes whatever. Gives even heat all day long without a bit of attention—a warm cozy house in the morning or a quick fire at turn of valve. You can absolutely depend upon your Oliver to heat your home tion. Get your Oliver installed immediately. in coldest zero weather —it gives 3 times the Fill in and mail the coupon now. OLIVERasBURNER OLIVER OIL-GAS BURNER COMPANY A-54 Oliver Bidg. St. Louis, Mo. “‘Oldest and Largest Manufacturers of Oil-Gas Burners in the World’”’ Canadian Distributors: A-54 Oliver Bidg., Toronto, Ont. 16 types to fit any heater or cook stove. Quick heat at once—no waiting for fire to come up. ee eee oe oe ee eee ee Oliver Oil-Gas Burner Co., e A-54 Oliver Bidg., St. Louis, Mo. Send me your FREE book “New Kind of Heat”, and special Low Price Introductory offer. I am interested in a burner for a Coal Heating Furnace. . O Range O Stove 0 (Specify steam, hot air or hot water) aa e ema ee eames ee Ss we es oe oe oe ol