Popular Science Monthly 1920-11: Vol 97 Iss 5

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Inventions— Machines— Automobiles—Electricity at (i | ular yi. | ] “4 HOW TO USE THE - mien “— VOTING Science = DRAWN BY W. B. HUMPHREY

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at ene a RATER a RETA PT a Tsar TF TSS + Who ever heard an-INDIAN rider kicking about bad roads? It’s the wonderful comfort-giving action of the famous Cradle Spring Frame that provides the INDIAN Powerplus with its well-known easy- riding qualities. No other shock-absorbing device can approach it in insulating the ma- chine and the rider from road jars. This exclusive INDIAN feature is made possible by light springs of special steel fitted to each side of the rear wheel in such a way that the REAR FORK and WHEEL are permitted to move up and down inanarc. This unusual assembly makes it possible for the WHEEL to adjust itself instantly to the inequalities of the roadway and so absorb the road-jolts that would otherwise cause discomfort to the rider and injury to the vital parts of the machine. Ask your nearest INDIAN dealer to demonstrate Power- plus riding qualities TODAY. Department 38 HENDEE MANUFACTURING COMPANY Springfield, Mass. The Largest Motorcycle Manufacturer in the World Popular Science Monthly $ Pop

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Popular Science Monthly Hunn) UTE Champion Spark Plugs to cut truck costs. They aid greatly in profttable, con- tinuous truck operation, because they end many of the costly i for repair and adjustment. Champion No. 3450 Insulator ef- fectively withstands the constant shocks, heat and vibrations to which truck motors are subjected in their long, daily grind of heavy duty work. Champion dependability accounts for the fact that Champion Spark Plugs have been adopted as standard equipment by more automobile, truck, tractor and engine manufac- turers than any other make of spark plug. There is a Champion Spark Plug specially designed for your particu- lar type of gasoline engine. Order a set from your dealer today. He can supply you. Be sure the name Champion is on the Insulator and the World Trade Mark on the Box Champion Spark Plug Company, Toledo, Ohio Champion Spark Plug Company of Canada, Limited, Windsor, Ontario DEPENDABLE SPARK PLUGS “= w/.- . . = oo . ‘ ~ ° _ “ 7 ‘ cneeicianiell - by ad =

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Now, why not obviate the Watch- ful Waiting for decay to manifest itself in out-of-doors woodwork by making everything of Cypress, “the Wood Eternal,” in the first placer | Well, sure enough—why not go ahead and obviate? This kind of foresight is Some Obviator when it comes to Lumber Re- pair Bills. | 1 Alin A ta It is possible that we might have a booklet you could use to ad- vantage—we have 43 of them in the Cypress Pocket Library. Some have plan-sheets—big and practical and artistic—and ex- clusive—and they cost us some- thing—you nothing. Volume One contains the list. Also what the government of the U. S. A. says about Cypress, “the Wood Eternal.” Our ad- dress is below. What is yours P Is it all right to askP All-round Helps Department Southern Cypress Mirs: Ass’n. | 1249 Hibernia Bank Building, New Orleans, Louisiana we i 1249 Heard National Bank Building, Jacksonville, Florida - 3 am Se OE St Popular Science Monthly palsies . Popular Science Monthly NOV., 1920 Volume 97-No. 5 | — CONTENTS AERONAUTICS The Airplane for You and Me.............. 33 By Airship to the North Pole............... 34 PAD ENR APONTE 5655 ooo 0 5.0 5 0 :ein's ine, bi0 00 0:0 42 A Balloon Hydrogen-Generator on Wheels.... 50 Weighing the ‘‘Lift’’ of a Balloon:.............. 75 His Oxygen Tank Useless.................... 86 INDUSTRIAL PROGRESS Carrying Milk in Tank-Cars................ 21 Heat Water with Steam.................... 33 A New Factor in Brass..................... 36 Hay Forked Down Automatically. .......... 36 An Ingenious Homemade Soil-Sifter......... 44 This Soda. Fountain Takes Care of Itself...... 44 The Telephone Calls Your Station........... 44 It Will Revolutionize Pipe-Laying........... 45 When in Need of Coal, Use Sawdust......... 48 An Automatic Steam Siphon................ 50 Enter, the Movable Electric Furnace........ 50 Steel Teeth to Cut the Ice.................. 61 His Master's Voice—Loud and Deep......... 71 What the X-Rays Reveal About Matter...... 73 Carrying a Railroad to Alaska................ 86 How One Man Lifts a Ton.................. 86 MEDICINE Living Forever—Why Not?................. 28 MONE BAROTE BOER 0.6 6 6.86.6 00 ose ene sess 42 MOTOR VEHICLES AND ACCESSORIES A Flexible Gate for Automobiles............ 33 Demountable Bodies for Automobile Trucks. . 38 The Automobile with a Rotary Valve........ 53 Trouble Gloves for Automobilists............ 58 Carrying Gasoline on the Farm............. 61 Primitive Styles in Automobiles............. 76 Protect Your Garage Air Hose.............. 82 To Mount Heavy Truck Wheels............ 82 How an Automobile Radiator Shreds the Air. 83 Getting Their Goats with a Truck........... 83 NATURAL SCIENCE A Maple-Tree that Braced Itself............ 49 Our Ears Deceive Us in Locating Sound...... 68 A Champion Among Goldfish. .............. 59 (Continued on page 4) Copyright, 1920, by the Modern Publishing Company POPULAR SCIENCE MONTHLY is issued monthly. Yearly subscription in the United States, $3.00. Canada, $3.50. Foreign, $4.00. Single copy, 25 cents. POPULAR SCIENCE MONTHLY may be had at all news-stands in the United States and Canada; also from the International News Company, London, and at Brentano’s, Paris. Advertising rates on application. Forms close the twentieth of the second month preceding date of publication. Entered as second-class matter Dec. 28, 1915, at the Post Office at New York under the act of March 3, 1879. Entered as second-class mat- ter at the Post Office Department, Canada. The contents of this magazine are copyrighted and must not be reprinted without permission. H, J. Fisher, President; R. C. Wilson, Vice-President; O. B. Capen, Secretary and Treasurer. Modern Publishing Company 225 West Thirty-ninth St. New York City Povular Science Monthly — le ee ae ee ie

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Popular Science Monthly November, 1920; Vol. 97, No. 5 25 Cents a Copy; $3 a Year Waldemar Kaempffert, Editor Published in New York City at 225 West Thirty-ninth Street —S——— a Carrying Milk in Tank-Cars The cost of milk can be reduced by transporting it in tank-cars heated by live steam from the engine NDER average condi- | tions, the quart of milk for which the farmer receives eight cents costs the housewife sixteen. In other words, the handling charges, plus the milk-dealer’s profits, is equal to the first cost of the product. Under present con- ditions the rail freight per quart of milk is one cent when the milk is collected within four hundred miles of the city where it is ultimately sold. If the plan proposed by F. F. Craft, of New York city, is adopted, the freight charge can be cut in half. Mr. Craft’s idea is to haul the milk hot instead of iced. This would permit the hauling of fresh milk for distances up By Joseph Brinker The world is brought up on milk. Eight cents of the price you now pay for a quart of milk goes toward bring-_ ing it to your door. Therefore a bet- ter system of transportation means cheaper milk. Mr. F. F. Craft, a milk expert of New York city, says that he can bring milk from the farmer’s cow to your doorstep for three cents a quart. Children in the large cities die for want of milk. A reduction of five cents a quart would save lives. to eight hundred miles — double the distance it is now practicable to haul cans of milk iced in transit. If this is done, it will eliminate a further increase in price due to a short- age of milk threatened by the inability of the present area of supply to keep pace with the demand for milk. Less than ten years ago, New York had a population of approximately three millions. To-day the number is six millions. Has the territory from which New York’s milk supply is secured increased? Statistics show that it has not. As large cities like New York and Chicago increase in size, it will become more and more difficult to secure the When the milk arrives at the city milk station it must be efficiently distributed. , tem of ‘“‘zones”’ containing the retail milk stations makes an easy solution of the problem of distribution AJanemhar 1007 "2" (RETAIL MILK STATIONS) » = * | SMALLER ZONES 21 In a large city a sys-

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we " eeancnpeninsipeaninding -imamiicnenenneune ; a tina ell a : . * Popular Science Monthly ees RES ae = al Here is a chart showing how milk can be brought from greater distances than are now possible by the usual methods: of handling the dairy products. required amount of milk. The only way to overcome this condition is to get the milk from points farther and farther away. Under the present method of hauling iced milk in cans, this distance cannot be increased be- cause of the limitations of train speed and the inability to keep the milk from souring before reaching its destination. The limit has been reached, for milk trains traveling at passenger-express- train speed of forty miles an hour take at least ten hours to carry the milk frem some sources to the city. How the Present System Began The first steam-railway milk train was run into New York city about thirty years ago. Then the milk was all collected within a radius of forty to fifty miles. Milk stations were built every three or four miles along the railroad by a private individual who received about ten cents a ean from ‘the railroad for every can of milk passing through his stations and hauled to its destination by that par- ticular railroad. The railroad was glad to pay this small amount because it helped to build up its business. Then, as the city grew, the farms with from one to ten cows that were formerly on the outskirts were turned into residential suburbs or into large estates. The dairy farmers moved far- ther out, with the result that the milk had to be collected from greater and greater distances. This has gone on from year to year until now the limit is almost reached. If an attempt is made to haul milk from greater dis- tances than four hundred miles by some more intensified method of ice refrigeration, the cost of ice and freight charges will make it impossible for that milk to compete with the milk col- lected within the four-hundred-mile radius. But now comes a man, F. F. Craft, a milk expert of New York city, who proposes to change the entire existing scheme by heating the milk instead of cooling it to preserve it; to carry it in from seven-thousand- to twenty-thou- sand-gallon tanks instead of ten- gallon cans, and to bring it from double the distance at no. greater freight charge, by saving in the cost of keeping it sweet while in transit. In the first place, he would use a huge steel tank mounted on an ordi- nary freight-car framework. This tank has a manhole at the top for filling, and is lined throughout with glass, so that not a drop of milk touches the metal. Around the outside of the steel tank is a layer of insulation, then an air space, and another layer of insula- tion, with an outside covering of cor- A city milk station, showing the method of getting the milk from the tanks and cooling it in the process of Pasteurization 22 The tank-car solves the problem rugated iron to protect the insulation from engine sparks. The filling-pipe extends clear from the manhole almost to the bottom of the tank, and passes through a hollow glass-lined float that rests on top of the milk and prevents it from swashing back and forth and turning into butter while in transit over the long distances. As the tank is filled, the float moves up the straight sides of the tank, but always remains on top of the milk. The space between the two layers of insulation is filled with live steam from the locomotive at a temperature of 125° Fahrenheit in the same manner as steam is now piped to heat ordinary passenger coaches. Temperature and Handling Economies This temperature, sufficient to keep the milk, is about the same as that at which milk is now drawn off the Pasteurization tank. The temperature of each tank is kept constant by means of an ordinary steam thermostat such as is commonly used on the radiators of our newer office buildings and pub- lic schools. But Mr. Craft does not consider the problem solved merely by the use of such :a_ heated: tank. He goes still further and elimi- nates many of the handlings that now go to increase the consumer. point of railroad pickup he loads the milk directly into the tank-cars from the Pasteurizing: plant, pointing out that, because of lower labor and rent charges, Pas- teurization can be done more eco- cost of milk to the’ At the

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November, 1920 GRE Chip Pn to. He Would Transport Milk in Heated Tank-CGars Fenton F. Craft was born in 1867 at Jefferson, New York, on one of the largest dairy farms in the state. He has been identified with the industry ever since and his knowledge of dairy conditions was valued so highly that his expert testimony was sought by the combined com- mittees of New York city and New York state charged with investigating the high cost of milk. While he was in charge of the largest butter-producing creamery. in the state of New York the first Pasteurizing machines were introduced into this country. It was from these machines that Mr. Craft conceived his idea of transporting milk in heated tank-cars instead of in cans in iced refrigerator-cars. He claims that in the milk-tank car, milk at 125° Fahrenheit can be shipped one thousand miles at no greater cost than that for moving it three hundred miles under iced refrigeration.

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1 7 ees ——— a Ty are reat iene rae RU AY ea ED i arta Bl nomically in the country than in the congested city. Because the milk is handled in larger quantities, there is no need for as many small stations as at present, and the new ones could be twenty miles apart. The territory within a radius of ten miles of each station could then be more economic- ally served by motor-trucks than farmers’ horse-wagons, and each of these steps would reduce the number of handlings and the price of milk accordingly. Gravity Saves Man-Power Arriving at the city milk station, Mr. Craft lets the milk flow out of the car- tank by gravity directly into the cooling-tank, from which .it again flows by gravity to the bottling- machine, where it is cased and moved on roller gravity conveyors directly into the bodies of great ten-ton trail- ers hauled by motor tractors. The saving effected by such a method of handling may be realized by contrasting the method with the present one, in which the milk is first placed in small cans on the farm; hauled to the nearest milk station in slow horse-wagons; unloaded and then loaded into the milk train; un- loaded again at the city freight-station; and loaded into tractors, which carry it to the city milk plant, where the cans are again unloaded into the Pasteuriz- ing tank, and from there into the cooler and the bottling-machine and thence to the waiting tractor. From this point in the path of the milk from the farm to the table, Mr. Craft maintains that the price can be still further reduced by those who want milk at a lower cost by making the buyers go to distributing stations in their own localities instead of delivering it by wagon to the window- ledge, doorstep, or dumb-waiter shelf. Although he does not wish to deprive those who can afford to pay the price of doorstep delivery, he claims that the price should and could be reduced from three to five cents a quart by the “carry” plan. As contrasted with the present method of horse-wagon, door-step de- livery, by which a driver delivers about 250 quarts a day at a cost of about three and one-half cents, he Popular Science Monthly would ship the milk in huge ten-ton trailers and tractors. These can de- liver to local milk stations or grocery stores approximately twelve thousand quarts a day in four trips at the rate of about one half cent a quart. How the Price is Lowered This would show a saving of three cents a quart, which, with the ability to buy milk from one to two cents a quart cheaper at double the distance from which it is now collected, would show a saving of from four to five cents a quart. This calculation assumes no saving in the freight cost, the sav- ing in icing offsetting the cost of haul- ing over the longer distances. An additional saving could be made by charging a deposit for every bottle taken from the local distributing sta- tion. Under the present scheme, the aver- age life of a milk bottle is twenty-two trips. If the buyers were made to find it worth while to return their bottles, the average life might be increased indefinitely and the price of the milk accordingly reduced. STEAM SPACE—=m INSULATION Ai STEEL TANK ~~ Not an oil-tank, but a milk-tank, is illustrated here. The tanks will hold from 7000 to 20,000 gallons of milk. A glass-covered float prevents the milk from splashing 24

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November, 1920 Lost! $6000 Worth of Radium! The electroscope discovered it among the ashes IX thousand dollars’ worth S of radium was throwninto a furnace. It came out in the ashes. How it was found and recovered makes an interesting story. A nurse was removing ten tubes of radium from a patient. She lost one in doing so. Six thousand dollars’ worth of radium in a tube the size of your little finger! A diligent search of the room failed to reveal the presence of the little tube and as a final effort the radium detective was called By Raymond Francis Yates wi setanoent. wettnn SSO none needs one from radium alpha, beta,.and gamma rays. Ordinarily air is a fair insulator, but when these radium rays get mixed up with it, its insulating or non-conducting properties rapidly vanish and it becomes a fairly good conductor. We can understand then that the air about a small quantity of radium—smaller than one can hope to imagine—is a poor in- sulator and if any charged bodies are present, their charges -are sure to leak off into the atmosphere. for. In this case he was Pro- fessor Lawrence of the Uni- versity of Rochester. The radium detective did not arrive on the scene armed to the teeth or prepared for an en- counter with some bold robber. He came in with a very simple looking in- strument under his arm—an electro- scope. The electroscope can detect the presence of radium in much the same. fashion we would detect Limburger cheese if it were hidden away. The electroscope is sort of. a “nose’”’ for smelling radium and in this respect it is tremendously sensitive. The electroscope is really an instru- ment for detecting electrical charges. We learned at school that like charges of electricity repel one For instance, if two tiny .pieces of gold leaf both had a _ negative charge, they would insist on staying away from each other; they would repel each other. If one had a nega- tive and one a positive charge, they would insist on remaining together, or, if they had no charges at all on their surfaces, they would be in- different. :. The electroscope works on just this principle. Two tiny pieces of gold leaf are suspended © at the end of.a metal rod en- | closed in a glass vessel and care fully insulated, which means that it is prevented from coming in contact with any- thing that is a conductor of elec- another. - Ordinarily air is a non-conductor, but the invisible rays from radium render it conductive, and when the electroscope is brought near radium the gold leaf loses its charges and comes together dry silk it will become charged with positive electricity. Part of this posi- tive charge from the glass rod can be made to flow to the surface of the gold leaf in the electroscope by merely bringing the glass rod in contact with the projecting metal rod. At this instant the gold leaf will fly apart and remain in this position until a con- ducting substance is brought in con- tact with the metal rod. If this is done, the charges on the gold leaf will leak off and it will come back to its normal position. If an electroscope is allowed to stand in a charged condition the charges will gradually escape into the atmosphere. The rapidity of this leaking process will depend upon the condition ofthe air; whether it is dry or damp. We will now set out to find the missing radium. Radium iscontinually shooting off tiny particles; atoms, really. Scientists call these emanations If an electroscope is brought near a small amount of radium, the gold leaf will instantly de- tect its: presence by coming together. If the radium is some distance from the electroscope, the gold leaf may move just a very small distance, but the radium detec- tive has a magnifier trained on it and if it moves he is sure to see it do it. When Professor Lawrence set out to find the radium, he set the electroscope up in-the room where it was used on the patient. The instrument failed to register. The radium had not been lost in the room. It was somewhere else. Probably the nurse got it mixed up with the bandages from the patient and it was thrown in the furnace. The ashes from the furnace were examined by the radium detective and, sure enough, the electroscope responded instantly. Further examination re- vealed the fused tube which contained the radium. The radium was not lost. The search: was . continued until every possible milligram of the valuable metal- was recovered. Radium will not burn. After Professor, Lawrence found the radium in the ashes, a hurry-up call was sent out for a_ physicist from a_ large radium company. After he arrived on the scene, the valuable ashes were placed in sev- eral quart fruit- jars and taken to the laboratory and all but $210 tricity. worth of the If a glass rod is $6000 worth rubbed _ briskly The scientific radium detective at work after having found that of radium was with a piece of six thousand dollars’ worth of radium was contained in an ash-can recovered. 25 an Se nT

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Popular Science Monthly How It Really Happened; In which is shown that those film palaces are not always

The director here is seated in front of the camera, giving orders. But when the pic- ture is taken, not even the edge of his hat will give his presence away. He is hold- ing the scenario in his hand

By means of her dummy Con- stance Talmadge is saved from hours of standing around while her director and cameraman decide on positions and lights. The dummy is just her height and has the same coloring— but the charm is lacking

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An audience is having its picture taken, and, in order that it may register properly, an orchestra is playing appropriate music. Nearly as many people are needed to produce the picture as are needed to produce the audience

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This picture shows a corner of a large studio after the day’s work. Many sets are left standing. Everywhere are lighting fixtures; therefore it is not surprising that a studio’s electric bill is some- times a hundred thousand dollars a year 26 It is not a real hotel lobby, in spite of the convincing pillars. The set was built in one of the: Hollywood studios. Notice how abruptly the balcony ends at the sides of the picture. Of course such rough details are not in evidence on the screen

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November, 1920 or, Movies in the Making breath-taking thrillers of the what they appear to us to be A moonlight scene on a canal in Venice—that’s what these carpenters have been told to construct. Will they succeed in presenting a realistic scene to the thousands who will see this picture? Abso- lutely; they’ve never failed yet Here is a Venetian scene—even unto the canal. It’s only a few inches deep, as can be seen by the high-water mark on the director’s boots. He’s telling the handsome stars to register love Seeing this ballroom on the screen you would swear it was taken in some millionaire’s home. In reality, it occupies little space. It is bril- liantly lighted, however, and the proper light- and-shadow effects are produced Half an elevator was needed for the picture, so half an elevator was built. The scene was supposed to have taken place in an expensive New York apartment. Who would guess that the elaborate landings were not real?

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Living Forever—Why Not? What the scientists have discovered about the secret of perpetual youth By Arthur Benington “ =, > dd A"

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“‘T have taken old and worn-out sheep and goats; I have grafted on them the glands of a goat or of a vig- orous sheep; and my ani- mals were rejuvenated and gamboled about just as they did when they were young.” VORONOFF. NY one of us can A get from an in- surance company an estimate of how long he may expect to live. He will be told that the average American white man lives sixty years and the average woman sixty- four. That is to say, of all white children born in America, the average age at death will be sixty for males and sixty-four for females. And if he asks the officials of the Life Extension Institute, they will give him great piles of statistics to prove to him that the expectation of life for men and women who have passed forty has actually de- creased and is steadily decreasing. Our Lease on Life According to C. H. Forsyth, in the Decem- ber, 1919, issue of the American Statistical Association’s quarterly, the expectation of life

Are We Wound Up Like Clocks? Who has not looked forward a hundred years and wondered what the world will be like, and then thought, “I shall not be here to see it???’ And yet—why not? Am I not a healthy man, in the prime of life, suffering from no disease of which I am aware, with a stomach that revels in Welsh rabbits at midnight, with a heart that pumps with the steady rhythm of a perfect steam-engine? And yet I would bet my life-insurance policies against a German mark that in a hundred years I shall be dead. You, too, are just as sure that you will not be here to see the year 2020. Are we, then, wound up like a clock to run for a certain number of days and then stop? We hear occasionally of men and women passing the century mark. We know the giant sequoias of California live for thousands of years. Dr. Eugene Lyman Fisk tells us - there is no reason why we should not live for centuries. Why, then, are we so sure that we shall not see the next century? In this article Mr. Benington reviews all that science has discovered to shed light on the question: ‘‘Why can’t we live forever?’’

natural stamina to resist the diseases that attack adults. Second, life has become so complex and strenuous that the hu- man body has not yet been able to adapt itself to the stresses and strains that are the in- evitable concomitants of the swift pace we are leading. Why We Die Dr. E. E. Rittenhouse tells us that there are always 1,500,000 Ameri- cans ill with preventable diseases; that four out of every ten deaths are preventable or could have been prevented. Dr. Eugene Lyman Fisk tells us that, of 28,000,000 men between the ages of eighteen and sixty, 8,500,000 show evidences of approach- ing organic disease or already have it. It is illuminating to read the causes of death. In 1917—a typical year, in which the figures were not complicated by the war—14.2 of every thou- sand persons in the United States died; out of every hundred thou- sand deaths 153.2 were from diseases of the for a male white of native parentage at ten years of age, which in 1890 was 56.1, had fallen in 1910 to 54.1. And the expectation at forty, which in 1890 was 32.8, had fallen in 1910 to 29.9. A large loss in expectation was shown also by the native white of foreign or mixed parentage. This seems a paradoxical result of all our modern science, all our vaunted hygiene, all our improved methods of medicine and surgery. What, one may ask, is the value of all this greater enlightenment and increased skill if it ‘cannot add a year to our lives and is even bringing us to an earlier death? The answer to this last question is double-barreled. First, our improved methods of taking care of babies are sav- ing a host of weaklings that, but for this care, would have perished in infancy, and that grow to manhood without the 28 . heart, 149.8 from pneumonia, 146.4 from tuberculosis, 107.4 from kidney troubles, 82.9 from apoplexy, 81.6 from cancer, 79 from diarrhoea, 25.3 from diseases of the arteries, 17.2 from influenza, 16.9 from diabetes, 16.5 from diphtheria, 16.3 from bronchitis, 108.8 from accidents of all sorts. Arte- rial diseases and diabetes show an increase that is really alarming; for in 1900 only 6.1 per 100,000 died of the

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November, 1920 former and only 9.7: of the latter. These, with those of the heart and kidneys, are diseases that result directly from the strain and stress of modern life. One has but to glance at the faces of a group of women of high society toward the end of the season to , see the ravages that high living and late hours have wrought upon them. “It is the pace that kills.” And it‘is the pace that brings on old age before its time. Many learned physi- ologists have speculated upon old age and its causes, and have written treatises to prove that we are all potentially immortal and might live for hundreds or even thousands ‘of years, if we could avoid—oh, so many things! And they have pointed to the lives of famous old men as examples of what we ought to do to attain to their extraordinary length of days. The classic example is that of Cornaro, who lived comfortably to the age of ninety-eight, his secret being his diet, in which he limited himself to twelve ounces of food a day. A living example is Count Greppi, an Italian senator and former diplomat, who is hale and hearty at nearly one hundred and one. Count Greppi says his rule of life has been to allow himself no sensations—he assures us he has never loved! If the price of passing the century be abstention from the joys of life, why live at all? Most of us prefer ‘‘a short life and a merry one’’ to a long life spent in clamlike seclusion. Nature's Reason for Limiting Life But mankind is not alone in growing old and dying. It shares this fate with all creatures, animal and vege- table. It seems that every species has its own allotted term aA of life, to which it adheres closely as an average, and Weis- mann has’ shown that this term among animals is usually that required for reproducing its kind and giving its off- spring such parental care as it may need. Among plants, the fungi live but a few days; there are an- nuals, biennials, and perennials, of which the baobab is known to live 5000 years. Many insects live in the image stage only a few hours. The ephemerids rise from their grublike stage and die at once. do not even eat, having no digestive apparatus. On the other hand, there are locusts that live seventeen years from the day to mate, They they are hatched. Eels live sixty years; pike two hundred; turtles live “‘And the days of Methuselah were nine hundred and nine years.’”” No wonder men made long pilgrimages to see him more than two hundred; small birds live seven or eight years; eagles more than one hundred; whales live several centuries; horses from fifteen to thirty years; elephants from thirty to forty, “though it is popularly supposed that they live to one hundred years. Parts of Us Are Immortal But when we get far down in the scale of.life we find creatures that never die—yes, and some that are very difficult to kill. The rotifers, for ex- ample, many of the bacteria, and some small nematodes can actually be desiccated and stored away in a dry place for a long time and then revived by moisture. Creatures that are unicellular are immortal—that is, of course, if some hungry thing does not come along and make a dinner of them. More marvelous still, we are assured by such authorities as Professor Jacques Loeb and Dr. Alexis Carrel Dr. Voronof, who did some remarkable skin, bone, and gland graft- that every single cell of our own bodies is, or can be, immortal. Dr. Carrel has fragments of .the heart of an embryo chicken, cut out eight years ago, which are still alive and growing. Leo Loeb has proved the immortality of cancer cells. Livers . removed from the body and supplied with artificial circula- tion secrete bile and produce urea; kidneys under similar circumstances secrete urine, and hearts continue to beat. And certain organs have been removed from men _ already dead, kept on ice for days, im- planted or grafted into the bodies of other men, and lived. The glands of reproduction have been transplanted from the bodies of dead young men into those of living old men, and not only survived, but rejuven- ated their hosts. Thus it is demonstrated that the death of the body does not involve with it the immediate death of all tissues and organs. If, then, every one of the myriad cells of our bodies is immortal, why, we may ask, can they not live as a group? Does life x life = death? To undestand this apparent paradox, we shall have to study the processes that go on with our bodies, beginning even before birth and ceasing only with death. Our Body Cells Never Die Friedrich von Mueller, lecturing at Munich five years ago, remarked that old age begins in adolescence, and that it would be almost true to say that we begin to die as soon as we are born. For death is only the climax of a long period of degeneration. A word we meet with constantly in medical litera- ture is ‘‘metabolism.” This is used to. describe the process by which the cells of our bodies absorb from the blood the nutriment we give them in the way of food and oxygen and eliminate the worn- out matter. These cells are formed of proto- plasm; each has its nucleus, and every: one of them had its origin in the split- ting in two of an- other cell. They have many different forms, according to the work they have to perform in the body. There are nerve cells, muscle cells, bone cells, livér z ing during the war. On a recent visit to the United States, this in the water, fly eminent: ch surgeon announced his willingness to transplant cells, gland cells, and about long enough the interstifial gland of a dead youth to the living body of an old man a multitude of 29 \

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oan einai > Pe Aan RAE cerns esitindite sia others. But all are essentially alike in that they are primitive cells resem- bling the unicellular animals at the bottom of the scale of life, and, like these, potentially immortal. They are all made of the four elements, car- bon, hydrogen, oxygen, and nitrogen, and the processes of metabolism that take place in them all the time are nothing but chemical changes. They have the power of turning the simple molecules that are led to them by the blood stream—taken up by it from the food we eat—into the more complex elements of which they are composed (anabolism), and splitting up complex elements into sim- pler ones (catabo- lism). This is a proc- ess of oxidation, and the power to perform these chem- ical reactions — a power that is pos- sessed by no chemist on earth—is inherent in each tiny cell. By this oxidation the cells keep all the organs of our bodies in working order, removing debris and repairing losses. The digestive juices in our stomachs and intestines prepare the food for absorption by the blood. Many persons have wondered why the cells of the stomach and intestines are not themselves digested by their own juices. Fermi says it is because the digestive ferments—principal of which are trypsin and pepsin—can not pene- trate living cells; and Loeb suggests that the living molecule of protein is not hydrolyzable. However this may be, we know that living cells are proof against attacks from _ these ferments. The. Battle Waged within Us In youth the metabolism is -prin- cipally a process of building up. When full growth has been attained, it is an even balance between building up and breaking down; in other words, it is a mere keeping in repair. When the body is invaded by the germs of a disease, a battle royal takes place between the soldiers or policemen of the blood (called phagocytes) and the invading army of microbes. If the former be the stronger, the latter are killed, and we recover; if the latter be the more powerful, the former are so reduced in number that they can no longer protect the cells of our organs from the poisons liberated by the mi- crobes, and we die. There are diseases from which we may recover, but which leave certain organs in a weakened or wrecked con- dition—like the devastated regions of France and Italy after the invading his doctors that he would not live past middle age. his diet to twelve ounces of food a day and lived to ninety-eight Germans and Austrians had been driven out. Such an organ no longer performs its functions as efficiently as before. There are also other diseases from which we never really recover; we may seem to, but the germs have merely barricaded themselves in such secret places as the marrow of our bones or the chambers of our brains, and they may break out again after many years. Luigi Cornaro, an Italian of the sixteenth century, was told by Some disease germs enter our bodies with our food; others are breathed in; others penetrate through a cut or abra- sion. Those germs that enter with our food find in our intestines a fertile field for their development. Metchnikoff at- tributed the onset of old age to the germs that flourish in the large intes- tine; he went so far as to say that if we had our large intestines removed, we should live longer, and he pre- scribed cultures of sour milk as an antidote to the poisons liberated by these germs. .. Again, the cells in their perpetual work of metabolism tire; Laumonier has shown that they slowly degenerate and their walls thicken; thus they can no longer get rid of the debris, and they become clogged with the prod- ucts of their own activity. The cells of our bones collect lime, and this gradually takes the place of the gristly part, until, as we grow older, the bones become brittle. Too often our arteries share in this same kind of Improper diet, lack of hardening, He reduced Popular Science Monthly fresh air, exercise and rest, over- indulgence in such things as alcohol and tobacco, help all of these insidious processes by upsetting the metabolism, overtaxing the cells, and introducing foreign poisons into the system. And thus does our body begin to show signs of age. Some organs degenerate before others. Friedman says our bodies begin to lose their elasticity after the very first decade of life. The thymus gland, in normal in- dividuals, atrophies at puberty; athletes attain their maxi- mum power before they are thirty and this then begins to wane; the eyesight starts on the down- ward grade at about fifty. These phases are manifestations of the degradation or death of the cells of the organs affected, due to wear and tear and poison, the latter either introduced from outside or produced by the cells themselves (autolysis). Repairing Bodies Like Clocks Attempts have been made, and seemingly with some success, to repair artificially the organs that have broken down or worn out under the strain of living. In recent years we have heard much about the functions of the so- called “‘ductless” glands, and a new department of medicine, called en- docrinology, has been built upon them. It is known that these glands—the thyroid, spleen, supra-renals, pineal, pituitary, and other glands, besides some of those that manufacture other secretions for which they have ducts, notably those of reproduction—pro- duce certain secretions which they pour directly into the blood without passing through special ducts, and § e “It is the pace that kills,” and it also ages prematurely—as any society woman can’ see for herself at the end of a strenuous season “30

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November, 1920 these secretions exercise a powerful but mysterious and as yet only partially understood effect upon our whole sys- tem. The thyroid gland, for example, situated in front of the throat on both sides of the ‘‘Adam’s apple,” affects our development. When it is absent or deficient at birth, the infant grows to manhood, but his mind does not develop and we have a “cretin,” a twenty-year-old man with the mind of a child of two. When, on the other hand, this gland is enlarged or works too vigorously, exoph- thalmic goiter is the result. The endocrinologists are now curing cretins by administer- ing extract of the thyroid glands of animals. And they sometimes. cure exophthalmic . goiter by cutting out the en- larged thyroid, but it is a dan- gerous operation. Extraordinary results of ex- periments with thyroids have recently been obtained by Julian Huxley in England, and upon these some of the English newspapers have based highly colored articles in which his discoveries are hailed as an “elixir of youth,” much as Dr. Brown- Sequard’s discovery of the properties of the ductless glands was hailed in 1856, and as the grafting of interstitial tissue from the reproductive glands, described by Lydston, of Chicago, and reannounced by Voronoff, of Paris, was hailed a few months ago. It is noteworthy that the wide- spread interest aroused by such dis- coveries as these is evidence of the almost universal desire to-prolong, not life, but youth! Experiments on Animals Huxley’s experiments were on sev- eral of the lower animals, to which he administered thyroid extract. Para- mecium (a unicellular animalcule that multiplies by splitting in two), when fed on thyroid extract, split twice as often as normally. Tadpoles turned into frogs twice as quickly as usual, but ceased to grow, so that the experi- menter had adult frogs no bigger than flies. On the other hand, tadpoles from which the thyroid gland had been ex- cised grew to a monstrous size, but remained tadpoles with tails and gills, never turning into frogs. The axolotl, which is the larval or tadpole stage of a great salamander called amblystoma, lives in the marshy streams around the Gulf of Mexico, breathing through gills like a fish. Its adult form, living on land and breath- ing air through lungs, is rarely seen, and it is only a few years since an accident revealed that the former The fungi in this picture will live but a few hours; while the turtle may see its two hundredth birthday develops into the latter. A strange fact about this creature—or these creatures—is that, although the ax- olotl is only the rudimentary form, as the caterpillar is of the butterfly, it often lives and dies without develop- ing further; it mates, lays eggs, and these hatch into new axolotls, while the adult amblystoma has _ never been known to mate or to lay an egg. By administering thyroid extract to aquatic axolotls, Huxley succeeded in hastening their transformation into land-living amblystomas. Thyroid extract is given to human beings as a medicine to stimulate their metabolism. Kendall has calculated that one milligram of it, in the form of thyroxin, will increase the metabolism of a one-hundred-and - fifty - pound man two per cent, and he has estab- lished a regular scale of dosage on this basis. After studying these and the many artificial methods now in use for re- pairing the deficiencies or the wear of our organs, and considering the multi- farious plans for safeguarding mankind from the attacks of disease or for help- ing him to conquer it, well may one wonder why it is that we all continue to grow old and die, just as our fathers In making repairs on the human body, doctors have recently trans- planted organs from monkeys to men with astonishing results $1 did before us. If our individual organs can be kept alive and healthy after we are dead, if the cells of our bodies can live on indefinitely, how is it that the totality of those-organs and ‘cells is doomed to perish? Professor Jacques Loeb, of the Rockefeller Institute, says: ‘‘Imme- diately after the cessation of the heart- beat and respiration, the cells of the muscles of the skin and probably of many or most other organs are still alive. and might continue to live if transferred to another body with circulation and res- Diration. As a consequence of the lack of oxygen supply in the dead body, they will, however, die comparatively rapidly.” For death is due to cessation of oxidation. As pointed out above, the activity of all the cells is merely a process of oxidation. To quote Loeb again, ‘‘While all the cells may be immortal, they can be-so only in the presence of oxy- gen and the nutritive solution which the circulating blood furnishes. With the proper supply of oxygen cut off, they can no longer live.”” And “some accident sooner or later introduces the poison that reduces immortality to mortality.” No Way Yet to Beat Nature We have not yet learned how to attain long life, much less to conquer death. If we would reach a ripe and healthy old age, we must work less, play more, breathe pure air, avoid all excesses, pay stricter attention to water filtration and to the efficient dis- posal of sewage and garbage; we must free ourselves from the bondage of the house-fly and the mosquito; we must eat and drink in moderation—in other words, we must do, collectively and individually, all the well-known things that help us to defy disease. But we should have begun with our ancestors, for most of us have inherited constitutional weaknesses or defects. It is useless to rely upon grafting of monkey glands.or injection of thyroid extract. By these we may succeed in speeding up the motor for a brief time, but the ultimate effect will be like that of putting new wine into old bottles, or picric acid into the gasoline-tank of an automobile—the engines will work with unwonted vigor for a few hours, and then all is over forever. Loeb suggests that every speeding up of natural processes is compensated for by a decrease in the span of life. And Dr. Edmond Perrier, commenting on the effects of thyroid extract upon the axolotl—transforming it from a breeding, egg-laying juvenile into an impotent, sexless adult—says: “If sterility is-the price we have to pay for eternal youth—no, thank you!”

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© Popular Science Monthly A Gunboat in War—a HE Kilmore was a British gunboat during the war; now She was converted from one to the other in two months! The picture in the upper right- hand corner shows the Kilmore in her war paint. She had a stern-shaped bow, which made it difficult for the Germans to know whether she was coming or going. But she is a merchantman. at a speed of ten knots. 32 Drawn by S. W. Clatworthy Merchantman in Peace now, with war paint off, and deck cut away, she is another vessel, as the picture in the lower left-hand corner shows. Now she can carry five hundred and seventy tons of cargo The conversion has been so successful that seven other ships in her class will also be made over into merchantmen

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November, 1920 This tiny airplane costs no more than an automobile, needs no larger shed to live in, and will rise and land in our back yard “TET’S go flying!” 4 You'll be saying that ‘before long with the utmost calm. Take for The ‘example the new sport ‘airplane shown herewith. It costs but two thousand dollars, and a gallon and a-half of gasoline will run it for an hour. Moreover, War Department records show that flying accidents are no: more frequent than automobile Airplane for You and Me accidents, considering their numbers. The new sporting airplane is much smaller than most. It has a two- cylinder, twenty-one-horsepower en- gine, with a maximum speed of fifty miles an hour. Its weight is only 425 A Flexible Gate Stops Automobiles HEN the careless chauffeur speeds toward a railroad cross- ing without heeding the “Stop, Look, and Listen” sign, there is likely to be an accident. A barrier to prevent vehicles from encountering this danger has been invented by Joseph B. Strauss, of Chicago. His device consists of two supports on opposite sides of the road, between which is held a movable gate suspended by suit- able weights and operated by motors. When a train is coming, the gate is lowered across the road. When an automobile reache the flexible gate, comii Noansom her. 7 aon the railroad crossing, it runs into to an instant stop If this obstruction were absolutely rigid, there would be a bad crash resulting from the sudden stopping of the truck or touring-car. But Mr. Strauss’s clever design allows for such an occurrence by this flexible obstruction, one that “gives” to a certain extent when the heavy motor vehicle strikes it. This permits of a quick stop without capsiz- ing the vehicle or demolish- ing the gate, providing, of course, that the chauffeur is not driving his vehicle too » recklessly. heated. It is called a sporting air- plane. No wonder! The wings can be taken off in ten minutes and the airplane turned into a tent pounds and it can land at the low speed of twenty-five miles an hour. A good sized lot ? will be sufficient for a landing-field. As for a hangar, any shed nine feet wide, twenty feet long, and seven feet high will do, -because the wings are detachable and can be removed in ten minutes.' A cable release lever makes this possible. Heat Water with Steam F you have steam heat, a new heater will provide hot water instantly. Live steam and cold water are conducted to a central chamber in which the steam, through small openings, is brought into contact with the water. The water condenses and absorbs the steam and becomes Open the hot-water faucet and you will obtain hot water heated to the desired temperature by steam From the mixing-chamber it passes to another chamber containing a the?mostat. flexible meta] bellows enclosed in a rigid shell filled with a volatile fluid, the boiling-point of which is a few degrees below the temperature of the water. As the hot water passes around the shell, the Jiquid within is volatilized and exerts a pressure on the bellows propor- tional to the water’s temperature. than desired, the pressure of the volatilized control liquid forces the bellows down, and with it a thrust-pin, which controls the valve admitting the steam This instrument consists of a If the water is hotter

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Popular Science Monthly By Airship to the North Pole The Peary of the future will explore the frigid zone in a floating laboratory ferred to the last desperate ef- fort of a Nansen, a Scott, or a Peary to reach his geographical goal as a ‘‘dash for the pole.”” Anda ‘‘dash”’ itis. A few dogs hauling a few sledges, one or two instruments, barely enough food to keep body and soul together -such is the equipment of the daring expedition that makes the supreme effort. Now, a polar expedition is essentially a scientific undertaking. Its primary object is to increase the world’s stock of knowledge. Science needs time to make its discoveries. It must have leisure in which to experiment and to penetrate into the unknown. The ‘Admiral Peary” A huge airship of the Zeppelin type will enable the explorer of the future to study the geography of the poles in a really scientific way. There need be no ‘“dwsh.’”’ The great gas bag can float for days over a given region. It will accomplish in a week what could not be accomplished in years with the aid of whaling<vessels and teams of dogs. That exploring ship of the future—of the very near future, in fact—will be a veritable scientific laboratory. Let us name her the Admiral Peary. Behold her, ready for her voy- age to the north polar regions. She is housed at the great hangar at Spitzbergen, whence sailed the ill-fated Andree and his com- panions in their free balloon, the Ornen, on July 11, 1897, never to be seen again. From the same spot, Danes Island, Walter Well- man, fifteen years ahead of the - time, also tried to reach the pole by dirigible: , a The Admiral Peary, stream- lined from bow to stern, a giant one thousand feet long, reaches from the floor of the immense hangar to its very rafters. Her diameter is one hundred feet; her crew numbers one hundred men; her load is two hundred tons. . You marvel at. her bulk. You enter this leviathan. You walk down the passageway. * .Countless steel trusses and lat- ticed struts encompass you and - extend almost as far as the eye canreach. These great tanks are filled with gasoline; those en- gines there equal the efforts of three thousand horses; that ele- vator takes you to the observa- IN ‘erred to the: have always re- By Lieutenant Clifford A. Tinker tion rooms one hundred feet above. The rooms along the sides are for the scientists. They are provided with many instruments and equipped with laboratories—the astronomer, the geol- ogist, the ethnologist, the botanist, the meteorologist. Here are the quarters of the crew and officers; there are the pantries, the dining-saloon, the hos- pital, the lounging-room; in the center is the dynamo-room and the radio equipment. Even a huge telescope is mounted in a well-like compartment amidships. On top are placed the four auxiliary airplanes for emer- gency use. The photographic depart- ment is housed in an after compart- ment. A walk of eight hundred feet along the metal-floored passageway toward the bow of the ship brings you to the streamlined pilot-house, which pro- jects ten feet below the main ribs of the hull. You descend and report. to the captain; who tells you that the start will be made in ten minutes. The great doors of the hangar roll open, the ship slowly emerges. The engines are warming up. A deep- voiced gong resounds through the length of the dirigiblé, and the land drops away. The voyage has begun. The time of starting and the hourly On top of the gas bag are the laboratories and cabins. And in the rear of this top-deck housing is an open hurricane- deck from which kites as well as sounding-balloons can be sent aloft

i

progress of the ship is sent by wire- less to Washington. Thanks to radio, you are but two minutes from home. The ship turns her prow westward. She crosses the open sea, so called by courtesy, for it is crowded by floating icy mountains. Great spreading floes, miles in extent, stretch out to meet the horizon. You wonder how far away that horizon may be. You step to the dial. The ship is at twelve hundred feet altitude, and thus it is forty miles to the horizon. Your range of vision includes an area of. more than five thousand square miles. Think of that in the polar regions, where in times past an entire expedition has. been so buried in by icy barriers that its mem- bers died of starvation, ignorant. of the rescue party only a few miles away. You are thrilled at the unending panorama, by the wonderful .fields of © snow and ice, and the stretches of water like blue veins between the floes, and the ghastly whiteness of the tower- ing icebergs as they topple and swing with crushing force against other bergs or burst through some narrow floe to waters beyond. Hark! The call tolunch. You pro- ceed to the electrically heated dining- saloon to. enjoy a four-course lunch, with salad and fresh fruit. You return to the pilot-house. To the Pole in a Week What is that gray mass over westward? Northeast Cape on Amdrup Land; Greenland, if you please. You have been flying along at one hundred miles an hour, and in one week’s time you will cover as much territory as all the arctic explorers formerly covered in four centuries. Thus the Admiral Peary floats over ice and snow, over chaotic frost-bound lands, over seas of steely blue, and gray wind-swept rock patches; on over the spots where heroes died, where wintered starving, desperate voyagers, where “Farthest North” was writ- ten, where hunger and disease turned back the brave. And then, at a certain hour, the cap- tain calls your attention toa patch on the frozen surface. As the ship descends for closer investigation, you make out a pile of stones peeping out of the ice and snow. “That,’”’ says the captain, with simple pride, “is Peary’s North Pole cairn!’

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November, 1920 a i e n,n To the North Pole A huge dirigible of the Zeppelin type will enable the explorer of the future to study the geography of the poles in a really scientific way. There need be no “‘dash.”” The great gas bag can float for days over a given region. It can even come down for a few hours. In this picture we have shown it anchored by the head, by Dirigible Airship so that the explorers may study closely the ice-bound region about the pole. The wind has lifted the tail of the airship, which accounts for its peculiar position. Not long may the explorers leave their craft thus anchored. Its positjon is precarious. The wind may beat its tail down upon the ice and wreck it beyond repair

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ae Melting brass by electricity is a new development. It gives closer regulation of temperature and more uniform’ production A New Factor in Brass EXT to iron and steel, the production of brass ps castings and rolled products is one of the largest of the metal industries. To make brass castings and such rolled products as sheets, rods, etc., it is, of course, necessary to melt the original pure metals first, to mix them properly, and to pour them into molds as castings or into ingots that are later rolled. For a long time this has been accom- plished by means of crucible furnaces or gas- or oil-fired but of the two processes, the oil- or gas-fired is to be preferred. Recently a new and igteresting development has taken place in the melting end of this industry— melting by electricity. The development of the electric furnace as a melting medium for brass and copper and other non-ferrous alloys has largely taken place in Popular Science Monthly Teeth ~ eee While You Wait HE Wakamba dentist does not look for cavities—he makes them. He chisels and then files his patients’ teeth until each tooth ends in asharp point. Why? So that his patients can tear raw meat with neatness and despatch. The Wakamba tribe is one of the least civilized tribes of Africa. The men will sell their wives for a few cows. Everybody eats raw meat; in fact, very little cooking of any kind is done. The idea of having one’s teeth chiseled and filed is not at- tractive, but the Wa- kamba men _ don’t mind it at all. One of them is shown be- low reclining in his dentist’s arms. Kadel & © Herbert The Wakamba have no cooks. In order to eat the raw meat, they have their teeth filed to sharp points furnaces. Whether melted in crucibles, or oil- or gas- Among the Wakamba, one of the least civilized fired, only small quantities can be melted at one time; “Tica tribes, the dentist makes cavities in teeth Hay Forked Down Automatically Fo a long time inventors have been designing machines for getting hay into the hay-loft, but none of them have worried about getting it out again. George Chromy, on the contrary, has felt the néed of such a me- the past two years. Electric melting has sev- eral advantages, among which are closer regulation of the temperatures, small- er loss by volatilization and spills, the handling of larger quantities at one time, and greater uniform- ity of product. , si cae Electric melting was WEIGHT ~& first used in melting silver. In' a few years it has spread to brass of all kinds, coinage metals and alloys, aluminum = and some of its alloys, and to other fields. The constant appear- ance of new non-ferrous alloys, some involving the use of the rarer metals, new uses for the more common alloys and metals, and the unlimited possi- bilities for new combina- chanical hay-puller and has therefore invented one. A handle, a weight, and : a fork, properly connected, MOVABLE. “ constitute the chief fea- M@HAY,- FORK OM NA tures of this machine. es Start with the handle. When the farmer wishes to pull down some hay, he turns the handle, thus causing a rope to wind aroundadrum. This rope Passes over a series of pulleys attached -to the roof, and terminates in a hanging weight. To that section of the rope that passes over the hay, .a fork is attached. Thus, when the farmer turns the handle, the fork drags across the hay and pulls it down. Then, when the handle is released, the weight pulls the fork back tions assure a wide use for i Turning the handle pulls down some hay from the loft. Re- to its original position, the electric furnace. leasing the handle pulls the fork to its starting position ready for a second trip. 36 Danning Saaennre Una th).,

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November, 1920 November, 1920 — Steam shovels at work, stripping the area of coal. It was no job for the city fire department; engineers had to be called in Fighting a Burning Coal-Mine Under a City The battle is still being waged HERE is a coal-mine burning - under one of Pittsburgh’s most exclusive residential sections. The fire started in 1914. A few months later it spread rapidly and became a source of great danger to the commu- nity. To know that a fire is burning . under the street you live on, with the possibility that it may actually extend under your home, would not add any- thing to your feeling of comfort and security. The people in the Squirrel Hill section of Pittsburgh, where the fire occurred, did not give the matter much thought until the street above the burning mine became so hot that pedestrians were unable to walk upon it. The street was completely undermined by the fire, and part of it caved in. The Engineers’ Plan This was no job for the fire depart- ment. Putting out mine fires is a job for engineers. Water could not be used, and it would not do any good even if it were possible to apply it. When the city engineers reached the fire and studied it, they decided to dig down a short distance and build a clay wall or barrier beyond which it would be impossible for the fire to spread. This plan was put into effect, and it By James Hope was thought that the fire would soon burn itself out. But the engineers were disappointed. The fire did not burn itself out. It grew hotter and hotter. The heat caused the clay wall to crumble, and the fire spread rapidly to thicker coal deposits. There was another hurry-up call for the engineers. This time they decided to strip the vicinity of coal as far as possible, and steam-shovels were put to work. The excavation was carried on with great haste to prevent the fire from spreading to sections forty feet beneath the surface. To permit the fire to reach these areas meant almost complete disaster to the entire com- munity. It was very difficult to fight the fire at depths varying from ten to twenty feet. At a depth of forty feet, effective work would have been almost impossible. Coal One Dollar a Ton The race with the fire continued for some time. Steam-shovels dug fran- tically. Coal became so plentiful that it was sold to the people in the neigh- borhood for: one dollar a ton. | At times during the operations burning portions of the mine were exposed. 37 ‘\ Although the fire was subdued to a great extent, it was not entirely ex- tinguished. The battle with it is still being waged. A Constant Supply of Oxygen “The coal-mine in which the fire started is a very old one. It has been abandoned for forty years. The fire received its necessary supply of oxygen through several openings. It is difficult to imagine how ferocious a coal fire may become, burning underground. As the oxygen is used up in the com- bustion of the coc’, a partial vacuum. is created. This lowering of pressure causes air to find its way in from the outside and the fire never lacks a fresh supply of oxygen. Coal-mine fires are not uncommon, but they usually occur in unpopulated districts where they are allowed to burn themselves out, owing to the great cost of extinguishing them. A coal-mine burning under a city is a more serious matter—it simply must be put out regardless of cost and trouble. [If it is allowed to reach deposits that extend beyond a certain distance underground, the job of putting it out becomes well nigh impossible. The use of dynamite is bad. It loosens the coal and offers more fuel for the fire. ee amano eT celica aac ieee I tn aac nas chy cent Po. 2 pln ee eo sa ety Liaapiet aa 5

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Demountable Bodies Will Keep Your Truck Moving How motor-truck failures be- came successes when loading and unloading time was reduced By Joseph Brinker MONG the 900,000- odd motor-trucks now in use there are some that do not save money in comparison with horses, if the cost per unit moved alone is considered. There are countless in- stances where horses are stillemployed because the truck apnarently cannot compete. So-called short hauls or excessively long loading and _ unloading times as compared with the time actually spent in mo- tion during the possible working day work in favor of the horse. The motor-truck is a means of modern highway transport only when its wheels are actually turn- ing. When it is standing idle, when, for example, it is loading or unloading, it is a mere’ repository for goods, and a most ex- pensive one. Truck opera- tion includes many im- ew Popular Science Monthly Lower delivery costs were secured by the use of detachable semi- trailers, loaded while the hauling tractors were on the road

Making the Motor-Truck Pay In this article, the fifth of the Popular Science Monthly’s series on the right way to use the motor-truck, Mr. Brinker takes up the important subject of demountable bodies. Here we learn how demountable bodies have made motor-trucks pay, after they had lost money because they were being used according to old horse-wagon principles. Efficiency of motor delivery is not to be mea- sured by horse standards. Other important business-building facts must be considered— among them the motor-truck’s ability to cover a great territory and to meet emergencies. Sometimes these in themselves justify the purchase of trucks. But the principle of keep- ing the truck moving, of cutting down loading and unloading time, should, more than any other, govern transportation by truck. Perhaps there are questions about motor- trucks and their uses that you would like to. trucks do the same amount of work as five * trucks without them. This is equivalent to a saving in truck costs and operation of over $12,000 a year. Besides, his demountable bodies enabled him to do away with the labor of two. loaders and one checker and to save $375 a month in wages alone. Thecost of the demount- able bodies and the equip- ment to hoist them was less than $2000. Yet they saved approximately $16,- 500 a year. This saving was made possible by cut- ting down the loading time from thirty minutes without demountable bodies to less than ten minutes with them. As they are loaded with groceries the demountable bodies are suspended in the stockroom from short overhead tracks running

portant factors, but none - of greater moment than the method of loading and ~ unloading,.for no delivery is complete until the eees <

ask. Send-them in. Mr. Brinker will be glad to give you the’ benefit of his wide knowledge and experience. perpendicularly. to the edge of the loading plat- form. These act as switch tracks from which the loaded bodies are trans-

are loaded and again un- loaded. A truck is losing money when its wheels are not turning. The greater the ratio between the idle standing time and the total possible working time each day, the less is the useful work done. To reduce to a minimum the idle truck standing time during loading and unloading operations, that is an axiom in the correct operation : of ‘motor-trucks. It is because Debiaiebbe héilion ‘help to reduce idle standing time that they are so important. They may be employed to equal advantage where either package or bulk goods are to be hauled, either between fixed points or on delivery routes. The success of the demountable body is not dependent upon the kind of goods moved, for it has been applied successfully in trans-

‘porting small packages of groceries or drugs as well as cases of goods weighing one half ton, loads of lumber, bags of mail, rolls of print paper, boxes of fruit, and even five-ton loads of bulk coal. Wherever the case of the motor-truck seems hopeless because of the con- Gitions of extreme loading and unload- ing delays under which it must be operated, the applied study of the principle of demountable bodies will in nine cases out of ten make the truck installation not only anaes but - highly profitable. A Saving of $16,500 a Year Take, for example, the case of a St. Louis grocer. By using five de- mountable bodies he made _ three 38 ferred by means of an overhead moving carriage upon a second set of tracks in front of and parallel to the edge of the loading platform. Thus a body loaded on any ‘one of the five switches may be trans- ferred to the second set of tracks in front of the platform and moved directly over the waiting truck chassis and then deposited upon it. Short hauls have always been the bane. of successful truck. operation. Let us see how a Philadelphia pub- lishing company reduced its haulage ‘costs 12 cents a ton on round trips only 1.1 miles in length. We will learn how wonderful are the saving possibilities of the demountable-body idea. This saving is perhaps the most noteworthy in the history of motor-truck installa- tions; for it was made not with one class of goods, but with five dissimilar Damalay» Vaanaso Manthia,

~w hawt es OF; = a ll le

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November, 1920 classes of loads, including rolls of print paper, bales of waste paper, bags of printed periodicals to be mailed, com- mon case freight, and even bulk coal. Using two types of demountable bodies, one chassis is able to haul five classes of goods at will. A box or gondola demountable body is used ex- clusively for coal. The rolls of paper, the bales of waste paper, and the com- mon freight are carried on the perma- nent platform of the truck chassis. A demountable platform body with mov- able side stakes is employed to haul the mail-bags of periodicals between the publishing plant and the railroad station, whence they are distributed. Reducing Traffic Congestion In this work, more demountable bodies are used than trucks, so that demountable bodies suspended by hoists in front of the loading platform are being loaded while other loaded bodies are being transferred from plant to railroad station and empty bodies from railroad station to plant. The successful operation of this plan neces- sitated similar equipment for removing the demountable bodies at the railroad station where the jurisdiction for install- ing such equipment was out of the hands of the company owning the trucks. Yet the demountable-body plan so reduced vehicular congestion at the railroad station that 28,000 pounds more of outbound mail could be handled daily without additional truck equipment; the railroad was glad to permit the erection of the overhead hoist necessary for the body removals. This is one of the few cases on record where an outside concern or one not owning or controlling the trucks used in the work, has cooperated to make the demountable-body idea one hun- dred per cent efficient at both ends of the haul. With a total yearly tonnage hauled of 105,000, this trifling 12 cents a ton saved by the use of electric trucks with demountable bodies, as against horse-wagons without them, has meant a reduction in truck cost alone of $12,600. By using the two types of demount- able bodies and the fixed platform of the truck as a third type, the trucks are never idle as long as there is work for them to do. When there is no mail to be hauled, the demountable body may be removed and the trucks used for hauling freight, bales of waste paper, or rolls of print paper, which last are removed by means of special electric hoists that can load or unload 9000 pounds in 12 minutes, or less than one third the time required by hand. When coal is to be moved, the demountable coal body is simply lowered upon the fixed chassis plat- form; the coal flows down from an overhead hopper and is unloaded by gravity. Both the demountable coal and platform stake-sided bodies are mounted and dismounted from the truck chassis by means of overhead hoists operated by a differential block and falls. Double Loading Capacity A wholesale dry-goods company in Baltimore, Maryland, spent $15,000 in a demountable-body installation and saved $22,000 in trucking costs during the first year, in addition to a like amount yearly ever since. In addition to these savings, the fact that the demountable bodies were already installed and in operation when the railroad congestion became acute dur- ing the war, made it unnecessary for the company to hire or build a new warehouse which would have cost at least $100,000. The demountable- body investment included thirty de- mountable bodies and fourteen sets of hoists. The bodies are used in con- junction with eighteen five-ton electric trucks to move the company’s goods between its main and subsidiary ware- houses. The use of the demountable bodies has practically doubled the work capacity of the trucks with which they are used. Without the demountable bodies each truck averaged about four - i lea Fem. DEMOUNTABLE ) |BODIES (LOADED) } DEMOUNTABLE [5 BODIES “a (UNLOADED ) é Showing the equipment needed for a motor-truck demountable-body installation. This arrangement of overhead tracks for handling demountable bodies enabled a St. Louis grocery firm to save $16,500 a year at an initial expense of less than $2000 November. 1920 39

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and a half loads a day. With the identical truck and a demountable body, the average number of loads a day has been increased to eight and one quarter. As shown in one of the accompany- ing illustrations, the method of in- ‘ stalling the demountable bodies is just the reverse of the usual procedure; for they are suspended from hoists, so that they are parallel to the edge of the loading platform in- : stead of perpendicular to it. This procedure was followed because it was desired to have all . of the loading and un- loading performed un- der cover, and to do this the bodies had: to be placed in an alley run- ning through the build- ing from one street to the next. Thus the trucks enter one end of the alley, dispose of theirempty bodies, have the loaded bodies placed upon them, and then pass out of the alley in the same general direc- tion as that in which they entered. This re- duces congestion in the alley and enables the trucks to change their bodies and begin their next trip within ten minutes. Easy Transference of Bodies The installation is also unusual in that no backing up or maneuvering is necessary for the transference of either the loaded or the empty bodies. The overhead hoists on which the bodies are ‘moved extend clear across the alley. When a truck with an empty - body shown here. body enters, it runs forward beneath one of the free hoists. The empty body is lifted off and moved sideways to the door in front of the loading plat- form. The truck then moves forward to a point opposite one of the hoists with a loaded body, which is moved sideways over the truck chassis and deposited upon it. A Brooklyn manufacturer of paper products has reduced the time of A manufacturer of paper products reduced the time of loading his five-ton trucks by twenty-five minutes by the use of the demountable loading each of his five-ton trucks from forty-five minutes to twenty minutes by the use of demountable bodies. These bodies are loaded entirely inside of the building; are picked up on an overhead hoist; moved to the loading door and transferred directly upon the truck chassis. At the present time hand-chain hoists are employed to propel the bodies from the point where loaded to the motor- trucks. It is estimated, however, that the loading time can be reduced from The bodies are loaded within the building and moved to the waiting truck chassis on an overhead track Popular Science Monthly twenty minutes to five minutes by the installation of an electric motor to propel the hoists and bodies on their overhead tracks. Bodies on Rollers and Nesting Bodies A grocer in Los Angeles has applied the demountable-body idea in an unusual manner by building the truck body in two parts, each part being mounted on roller casters which per- mit the truck body to be moved at will around the stockroom while being loaded. When ready to be transferred to the truck chassis, each body is picked up from the floor by an_ electric crane which runs on overhead telphers or tracks leading out over the truck chassis at the loading platform. By the use of the electric telpher, all hand move- ment of the bodies has been eliminated. The truck leaves with its loaded body within five minutes after it has backed up to the loading platform with its empty body. Before the demountable bodies were employed, it often took a whole hour to load one truck because of the large number of packages required to make up a five-ton load. . A further development of the de-’ mountable-body idea appears in the form of nest bodies, which are placed inside of the usual body permanently mounted on the truck chassis. One ‘How the demountable body, mounted on rollers, is pulled off the truck chassis on to an inclined platform when empty, and allowed, after having been loaded, to roll down the platform by gravity to the truck chassis. Two bodies are used with one truck 40

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November, 1920 CHAIN good example of such nest-body de- sign is that used by the Arlington Mills in Lawrence, Massachusetts, where skeins of yarn are loaded into wheeled hampers in the spinning- room and then rolled to the edge of the loading platform, where three of them can be placed in the ordinary body of a two-ton truck. This takes but two or three minutes of the truck’s time, whereas at least half an hour would be required if the same amount of yarn were loaded by hand into an ordinary body. Even loads of lumber may be car- ried successfully in demountable bodies. One lumber company in Neponset, Massachusetts, employs two demountable bodies in connection with each of its trucks. One body is loaded at the lumber-yard, while the other is on the truck making its deliv- ery. The demountable bodies are moved about the yard on_horse- wagons for the collection of the loads, and when.loaded are moved, to two horizontal beams placed on either side of a driveway. LOADING DOORS . we é& ia OVERHEAD | ... TRACKS HOISTS ,sililllll® Drugs also may be transported with success in demountable bodies. One New York drug company employing fifteen demountable bodies in con- junction with ten motor-trucks has been able to handle a three hundred per cent increase in business without the addition of more trucks. The Demountable Trailer In still other applications of the fundamental idea, demountable bodies may take the form of trailers which are detached from the hauling tractors when backed up to the loading plat- form to be loaded. The front ends of the trailers may be supported by means of wooden horses, jacks, or even stands pivoted to the under side of the semi-trailer frame and swung up out of the way when the trailer is connected to the tractor. The use of semi-trailers in this manner permits larger loads to be carried than could be moved on _ conventional Thedemountable-body in- stallation pictured above cost $15,000. It saved $22,000 each year in idle truck time. The de- mountable - body equip- ment enabled the trucks to double the tonnage of goods handled. Thirty demountable bodies are used with only eighteen motor-trucks trucks of the same engine horsepower as the tractor. One wholesale grocer, who operates a chain of thirty-nine hundred retail stores, employs at its main plant a fleet of thirty-seven trailers used in conjunction with twenty five-ton tractors. Ordinary trucks proved a failure at first in this work, because it took each one two hours to load. The semi-trailers, loaded in advance, can be coupled to the tractors in eight minutes. The same idea of demountable semi- trailers has been worked out success- fully for the transportation of fruit from the orchards to the packing stations and from the packing stations tothe railroads. In one instance, threc five-ton trucks and nine six-ton semi- trailers have displaced one hundred and twenty horses in moving the fruit between the orchards and the packing- houses and thence to the railroad shipping-point. Three trailers are used with each. tractor, one being loaded at the orchard, one Here jacks are employed to lift the beams vertically and remove the bodies from the horse-wagons. The _hori- zontal beams are then jacked up still higher, so that the truck chassis may back directly beneath the body. The body is depos- ited upon the truck by re- leasing the jacks. ; By this means idle load- ing time of the lumber truck has been virtually elimin- ated. Without demount- able bodies it took over an en route, and the third at the packing-house. . As soon as a tractor arrives at the packing-house from the or- chard, it drops its trailer and returns to the orchard with its empty trailer. Each trailer is equipped with jacks, mounted on a stand suspended from the- trailer frame. When con- nected with the tractor, the jacks and frame. are swung up out of the way. The efficiency of the semi- trailer demountable body is further increased by the hour to load ‘the sme amount of lumber. In loading skeins of yarn, nest bodies on rollers have reduced the loading-time from one half an hour to three minutes 4l use of. gravity-roller con- veyors for unloading.

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The patient in the chair is connected electrically to a sensitive current-detecting instrument Your Heart’s History RINK a cup of coffee, smoke a ciga- rette, find a hundred-dollar bill, and your heartbeats will quicken. All of these irregular actions of the heart can now be recorded upon a moving photographic film by the electrocardiograph. It has been found that the heart, upon contraction of ey ges hago a. certain of its muscles, generates a small vibrating fiber of quartz electric current. This current fluctuates upon a moving-picture with the movement of the heart, and by film recording these fluctuations the electro- cardiograph will cause this organ to write its autobiography. The electrocardiograph is one of the most sensitive instruments in the world. When it is properly connected with the human system, no movement of the heart is too small or too weak for a it to record. This instrument is capable of laying \ bare the innermost secrets of that little organ that faithfully pumps blood through our system. The Ejiathoven galvanometer -is really the “heart” of the electrocardiograph. It is nothing more than a sensitive instrument for the detection Here is a city unsurpassed by any in ‘“‘Gulliver’s Travels” Popular Science Monthly This City Is a Toy OU can look down upon a city in miniature and see moving street-cars, automobiles, crowds of people, and all phases of metropolitan life reproduced in a passing show before you. This is not a freak, but an actual toy, which can be used to demonstrate the interesting inven- tions of the day. With clever electrical manipulation, automatically con- trolled, the daylight comes upon the city and its street life begins. Automobiles, wagons, trains, and street-cars operate; and people, resembling the Lill putians described in ‘“Gulliver’s Travels,” move about through the streets. Some of them crowd about the door of a moving-picture show, as true as life itself. As the day advances and dusk drops its‘soft light, the illumination of the shop-windows be- gins, and the city takes on the brilliancy of artificial illumination. The headlights of trains glimmer as they emerge from the tunnel and stop at station platforms. The fountain in the public square begias to play and colored lights - cast their glow upon the shrubbery of the park. In this toy city a boy finds interest in the mechanical equipment of present-day urban life. Perhaps it will influence his whole future. As the Crow Flies of weak electrical impulses. "THE Crow is one of the world’s smallest airplanes. It A fine thread of spun quartz is suspended between the dots the blue sky of England. It can carry you at a poles of two powerful magnets. When an electric current speed of sixty-five miles an hour. The British Crow weighs passes through this fiber of quartz, it will be dis- turbed, the extent of the disturbance depending upon the strength of the current. If the shadow of the fiber of quartz is cast upon a moving pho- tographic film, every movement of the quartz may be recorded. By suitable connec- tions with the human body, the minute current generated by the heart may be caused to pass through the quartz fiber of the electrocardiograph and the record is then produced upon the pho- tographic film. The sen- sitive quartz fiber is faithfully sympathetic to 220 pounds and has a wing spread of but six- teen feet. Its motorisa forty-horsepower engine, twin-cylinder, air-cooled, mounted on the front of the plane. It forms, with its mountings and gas-tank, a complete unit that can be easily detached. Mr. Fred- erick Koolhaven is its designer. Those who have fol- lowed the development of the airplane will find a certain similarity be- tween this machine and the old Demoiselle of Santos-Dumont. Like the Demoiselle, the Crow is probably difficult to control because of the every movement of the Get in and take a ride with the British Crow. This flivver of the air very high center of heart. can carry you at the rate of sixty-five miles an hour gravity. 42

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November, 1920 No waiting on weather “TOOK at the leaves blowing! _ . What a gale!’”’ You see the tree-limbs bending almost. to the ground in the foreground of the screen-picture, not to mention the house being blown down while its occupants are apparently seeking fresh fields and pastures new. The sheets of water blow violently over the top of the portico; the wet shawl around the shoulders of the drenched heroine flaps violently in the wind. ‘There must have been a terrible storm when they took that pieture!’’ is the. natural conclusion the audience. Indeed, no! The day was unusually calm. The moving-picture men might This wind-machine can create a seventy-mile gale. It is equipped with a dynamo for use indoors and with a gas-engine for use outdoors And the Wind Blew _ have waited a month in the movies for such a storm to fit the scene. And then they couldn’t have taken photographs at all. But they didn’t wait. They had a wind-wagon that ° would furnish all the wind necessary. An airplane propeller, mounted on a movable frame and equipped so that it can be run by either a gas-engine or an electric’ current, is the wind- machine of the moving-picture studios. It would be most dangerous to make use of a gasoline engine in the studio, where inflammable film is used. Soa plug is connected with a two-hundred- 43 and a trans- and-ten-volt current, former on the wind-wagon regulates the speed of the dynamo that turns the propeller. It can make four thousand revolutions a’ minute, creating a seventy-mile gale. Outdoors a gas-engine is used in- stead of the dynamo. The wind from this machine is powerful enough: to blow down frame buildings.

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2° > ‘ so Ta uh nt OE A Hot Meal on the Spot Y carrying with him a_vest-pocket kitchen, when the noon whistle biows, this mechanic is enabled to set up his stove, light the fire, and in a few minutes have a hot meal ready. This little kitchen is so efficient that three dishes can be heated at one time— coffee on the lower deck, soup in the mid- dle and beans on top. A few cubes of solidified alcohol in the firebox furnishes the -heat. When the cooking is finished, the oxygen supply is cut off and the fire extinguished. The remainder of the solid alcohol cubes can be saved for use in preparing the next meal. An Ingenious Homemade Soil-Sifter HIS electric soil-sifter is used in the greenhouse of the Kansas State Agri- cultural College. A clever student con- cocted it from an old motor, two gas-pipes, the framework and wheel of a sewing- machine, and an iron hoop. This material he arranged into the position seen at the right in the picture. Then he placed the hand sifter on the iron hoop supported by two legs. These he bolted to the work- bench. Taking a steel arm, he fastened one end to the sieve and the other end to the crank bar. The motor was started, the sieve moved from side to side, and in five minutes it thoroughly sifted a bushel of soil. A Soft-Drink Fountain that Takes Care of Itscif. “TROP a nickel in the slot and get a marriage license’’—so the nickel- in-the-slot machines of the future may say. Automatic vending by the slot-machine is growing every day. You can get a shoe- shine, postage-stamps, stationery, soap, towels, drinking-cups, candy, peanuts, gum, newspapers, moving-pictures, and music from vending-machines. A measured quantity of any kind of soft drink can be obtained from the vending- machine shown in the picture above, which takes the form of a large oak barrel. As many as eight drinks can be drawn at one time. Each spigot has a supply of sanitary paper cups placed near it, which are made available by inserting one cent in a slot. The capacity of the oak barrel is sufficient to provide eight hundred people with a cool, refreshing drink before it be- comes necessary to refill it. The base upon which the barrel stands is used as a receptacle to accommodate the used cups. When this drink dispenser is placed in a busy locality, as much as four hundred dollars has been earned by it in a single day. Popular Science Monthly The Telephone Calls Your Station [* will be your own fault if you ride past your subway stop when this system comes into use. The guard calls the stop into a telephone transmitter, and his voice is reproduced in the vestibule of each car in the train. Loud-speaking telephone receivers, used in connection with a special form of am- plifier, solve the problem. The voice, loud and articulate, can be heard above the noise of the train. This new development for the comfort of the traveling public is the result of the work of E. E. Trafton, the telephone en- gineer for the Brooklyn Rapid Transit Company of New York city. Getting Sunburn without the . Help of the Sun N° longer is it necessary to go to the + “_ seashore or country to develop a well tanned skin. It can be done at home— while one sleeps, if preferred. The little blue daylight lamp will produce a sun- burn within a few hours. It has been found that the rays from one of these lamps are just as healthful as those from sunlight. It is the ultra-violet light from the sun that tans skin. Every electric-light fila- ment gives off these rays, but the glass bulb prevents them from escaping. The little lamp shown is provided with a quartz bulb through which the ultra-violet light may pass. A special reflector concentrates the rays. Popular Science Monthly eo. . late ied A OO”

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November, 1920 It Will Revolutionize Pipe-Laying WO Englishmen, Captain A. R. Mang- nall and Captain Irving, have invented a machine that will revolutionize present- day pipe and cable laying. The portable apparatus weighs only thirteen hundred pounds, and consists of a hydraulic cylinder carried on trunnions in a carriage, and capable of being turned from a horizontal to a vertical position. Inside the cylinder is a piston. This “gun” is dropped on to its framework in the pit, and is connected to a gasoline- driven pump set. The water is in continual circulation. - The gun is turned to a vertical position and the ‘“‘pilot” is dropped into it. Then the gun is turned down, and, after being alined on position at the next pit, the pilot is thrust into the-ground. The ad- mission and exhaust valves are operated by one lever. The gun is again raised, and the first extension piece pressed into it; once more the gun is lowered, and the pilot thrust forward by the extension. This operation is repeated until the -boring is completed. The operation occupies less than one minute. Another Vacuum-Cleaner Job ACUUM cleaners will fill pillow- casings with feathers! This kink was discovered by a husband who one day found his wife filling with feathers both a pillow-casing and the workroom. The husband took an embroidery-ring, placed it over-the open-end of-the. casing, attached the casing to the back of the cleaner, and when the cleaner was set in operation over the feathers, it sucked them into the casing. Rescuing a Drowning Cork MAN the time you’ve pushed a cork into a bottle when trying to pull it out. Can it be fished out? Try this: Grease the inside of the bottle’s neck with -vaseline and-hold the bottle under the cold water for a few minutes. Spear the cork with a hatpin and draw it up into the neck of the bottle. Then heat the bottle. The expanding air within will force out the cork. First Aid to the Wheel A CHIPPED wheel-flange or a broken axle will hold up a freight-train and perhaps several others. But there has been invented a skid shoe that will enable any train with broken wheels to limp to a ‘siding-for repairs. ‘The skid shoe shown below fits in front of the wheel. The shoe will slide along the tracks, and is so made that it will not falter when it reaches either a curve or a switch. The Boy and the Binder It is no wonder that the eleven-year-old boy in the picture has a broad grin on his face. Farm work to him is as easy as driving a horse and buggy. He sits on a small seat at the rear of a combination tractor and eight-foot wheat-binder, hold- ing a pair of ropes in his hands, and feels that he is lord of all he surveys. By means of the ropes he controls the speed and direction of his machine. To the uninitiated the binder appears to be a most complicated piece of machinery; but in reality it works as smoothly as the surface of the farm land permits. Can you imagine any child-labor law in the land being strong enough to prevent farmer’s sons helping their father, with such a fascinating farm-tool as this? © Formerly it took two grown men to do the work this boy is able to accomplish with the aid of machinery. Once again the law of compensation is proved not to be a myth. Farmers are short of laborers, and along comes this machine and eliminates one man’s work, or should we say the work of one man and a half? Seeding the Cantaloup GEEDING cantaloups is an art deftly performed by the natives of the regions in which they grow. The two halves of the melon are turned quickly around a stiff piece of rind, or other suitable object held between them. This motion dislodges the seeds, and they are collected in a vessel for future planting. Tradition credits this extremely popular fruit with having been imported from Armenia. ; November, 1920

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The Community Grinder A Soop advertising man is this dealer. He sells abrasive ma- terials and he believes in advertising the fact. To do this he has put a large grinding-wheel on the front of his shop where the passers-by can stop and sharpen their pocket- knives. The stone has become so popular that the housekeepers of the neighborhood come to the store to sharpen their kitchen knives. It has become the neighborhood grinding- stone and it serves a very worthy purpose. People gather around it to sharpen their knives and chat, the way they used to gather around the neighborhood pump. The shopkeeper claims that it has done much to help his business, people fre- quently recollecting their need of some item displayed in his windows. Horses Up to Their Hips in Mud HE horses are not sitting down to take a rest. They are trying very hard to get up. Their hind legs are under the ground, not on it. The potato-field in which the horses were working was very boggy, and, without warning, their hind legs sank. The more they try to get out, the further in they sink. On the whole, though, they don’t seem frightened. The potato bags standing erectly in the foreground will have to wait until the horses are extricated before they will be collected and carried to town. It seems evident that the farmer has gone to get help. Even the Fire in the Fireplace Is Unreal Ts cheery glow of the fire is quite un- able to rouse the listless moving-picture heroine pictured above. Perhaps it is because that cheery glow is just the concentrated effort of several powerful electric lights operated by an electrician behind the scenes. And the flames that seem to be rising from the logs are really spurts of steam issuing from jets hidden behind the imitation logs. So, of course, there is nothing at all cheery about the fire from the actress’s viewpoint. There is little doubt, however, that the audience will enjoy it to the full and wish for one like it, and young couples will make a vow that their new home shall have one. Whether the interests cf science excuse our so mercilessly exposing an illusion of the moving-picture world, is a matter that must be decided by the individual. Pri- vately, we have our doubts. Popular Science Here’s the Parasol-Purse ” spite of the cool weather, the chief bather in the picture above carries her sunshade with her. But she does not put it between: herself and the sun. It is the latest thing in sunshades and must not be left at home. When the sunshade is closed, it be- comes a handbag! The umbrella handle disappears discreetly within and the newly made bag is carried by hoops. Half of the handbag may be seen hanging down one side of the umbrella; the other half hangs down the other side. They look like orna- ments, but they contain all the young lady’s valuables. What does she do with her precious parasol when she goes into the water? That’s easy: she doesn’t goin. Why put on pretty clothes just to get them wet? “Hens Out Walking with Their Keeper ENS are so scarce in Germany that they are never allowed to run around loose any more. They are closely watched and kept in captivity. Every day they are taken out for a walk, but they travel at the end of astring all the time. At night vari- ous members of the family to which they belong take turns at playing watchman. The hens in the picture appear to fully appreciate their new dignity. Their ancient enemy, the dog, has lost the pres- tige of former days. The birds strut along, not realizing, possibly, that use and not beauty is the reason for their importance. _ eam ee SO VLEET Spe eps Wee “ge gE “a ( ae a ? er Ponular Seience Month],

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November. 1920 November, 1920 we ae Painting Traffic Lines PAINTING traffic lines is a quick and easy job when you use a painting machine like this one. The machine re- sembles the whitewashing machines used for marking lines on a tennis-court, but its action is entirely different. The paint does not drip upon the pavement. It is fed to a rotating circular brush that distributes it evenly in a narrow strip. As the brush approaches the narrow opening through which the paint is fed, its bristles are compressed between walls that extend on either side of the opening. The bristles are also bent backward because of the decreased distance from the hub to the opening. At the point of greatest com- pression the brush reaches the feed open- ing; whereupon it starts to expand until it reaches its normal size in time to paint the pavement. The action is the same as in hand-painting, and the results are just as smooth. Above a man is painting a traffic line on a street. He travels quickly and will have completed the job in a few minutes. The Rat that Was Electrocuted by Motor | Faemaae little while you hear of a rat 4 jumping off the stairs and breaking its neck or leaping into a pail of water and drowning. Here is the sad case of a rat that electrocuted itself in true Sing Sing style. It stepped unknowingly: on the electrical. terminals of a high-powered English car, short-circuiting the current through its body. The driver of the car found it suddenly without juice. He started to hunt the source of the trouble, and came upon the burned body of the rat. The rat. must have caused quite an arc when it took the fatal step, for the main switch was also badly burned. At least, this rodent showed good judgment when it picked out one of the most expensive English cars in which to do the deed. Seriously speaking, the rat has become an electrical pest. Central station men dread it because of. its: short-circuiting proclivities. It is always stepping in where people fear to tread, even though it is ab- solutely unfamiliar with the laws of electric- ity. However, a dead rat is always good for the community at large. 2 A ONS RaiBi es iid thik, © Kadel & Herbert Eating the Greedy Camel A the present price of grain, a camel is an expensive pet to keep. He will eat three dollars’ worth of food a day; whereas a boa constrictor is satisfied with one rabbit a month. When two exhibitors exchanged pets, the new camel-owner couldn’t stand the ex- pense. Hesold the camel to a butcher, who cut the animal up and sold him in steak form to hungry customers. This happened in Paris, where horse meat is not unknown and lion meat brings a fair price. However, we feel very sorry for the camel. If he had known what was in store for him, he might have dieted. These Telegraph-Poles Are Getting a Creosote Bath ONGER life for telegraph-poles is made possible by alternating hot and cold baths. The number of poles that can be treated at one time varies with the size of the treat- ment tanks. The fibrous inner bark is removed from the end of the pole that goes into the ground; then the end is lowered into a tank filled with creosote heated to a temperature of 212° Fahrenheit. The pole remains in this hot bath for several hours and is then plunged into a cold creosote bath, there to remain for another two hours. . When the pole is taken out it is ready for years of hard service. Creosoted poles do not rot, and insects avoid them. This process of preserva- tion is used especially for cedar telegraph-poles. ‘ 9 a ipa. ME Ses a ee ene oe re Sos i a ne a Sty ee

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Salted Peanuts Roasted in the Shell he is no longer necessary to shell peanuts before they can be salted. They are now soaked in a strong brine, drained, and placed in this special roaster. Before the process of roasting, an air pressure is applied that forces the brine through the fibrous shell of the nut, imparting a delicate flavor to the kernel. This done, the roasting is started and con- tinued in the usual manner. The little roaster shown in the ' photograph below has been perfected especially to carry out the new proc- ess of making peanuts salty without removing their shells. This serves to keep them clean and fresh. Separating Seeds by Their Shape A NOVEL seed-separator divides round seed from those that are egg-shaped, elongated, flat, three-cornered, or whatever shape a seed may be. It consists of two series of spiral channels through which the seeds are passed. The inner spirals are lower than the outer series. The round seeds attain greater velocity in flowing through their spiral passage, so that they jump the low barrier and ulti- mately are deposited in the larger spiral, whence they empty through special spouts into bags. The seeds that are not circular remain throughout their course in the inner spiral and are delivered into other sacks. The separator is chiefly valuable in separating vetch from rye seed. @©Keystone View Co. Polishing Brass Buttons without Injuring the Coat hap echet the fascinating power that brass buttons have on the gentler sex, it behooves all officers to make their buttons shine brightly. But how can brass polish be applied to buttons without the risk of getting it on the cloth beneath? A New York patrolman’s wife solved the problem by inventing a glass shield that is placed around the button. The shield is made of two pieces of glass, each semi- circular in shape, which fit together. At the center the glass is grooved to receive the button and at the top it is grooved to make way for a spring adjustment that holds the shield in place. Each semi- circular piece of glass is placed in a metal frame, and the two metal sections are linked together at the bottom and held together at the top by the spring. When the whole shield is in place it looks like the headlight of an automobile. It isolates the button completely and enables the person who is cleaning the button to polish it as strenuously as he would a doorbell. Above you see a dutiful policeman’s wife polishing her husband’s brass buttons. We hope sincerely that he will not take advan- tage of her good work and try to dazzle the passers-by. Popular Science Monthly When in Need of Coal, Why Not Use Sawdust? ITH coal at fourteen dollars a ton, the use of sawdust as fuel will interest many people who have to heat homes this winter. An officer in the British army has invented a small stove that uses saw- dust as fuel. He claims that it will keep two rooms comfortably heated in the coldest weather. Its construc- tion is very simple, sheet iron being used throughout. It is claimed that thestove will burn for twelve hours on one filling of saw- dust, which may be obtained at the local lumber-yard for a few cents. Sawdust burns quietly and produces practically no flame. The Easiest Way to Fly AKE a seat in a chair behind the painted airplane shown in the photo- graph. You will appear to be suspended in the air in flight. To make the picture more humorous, the proportions of passengers and airplane can be disregarded. Thus the photograph will show a large-sized image of yourself and friends and the flying-machine will appear ridiculously small. Before airplanes were invented, it was common to make such pictures, using a donkey-cart as the vehicle of transporta- tion. Then the automobile was used. One could see a picture of a small auto full of big people. Now the airplane has arrived for its share in the funny picture-maker’s art.

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November, 1920 Washing Photograph Prints HEN a lot of prints are placed in a flat tray to be washed, great care must be taken to prevent them from stick- ing together in such a way that some are imperfectly cleared of hypo. Here is a device that assures perfect washing, and chapped hands are avoided. A mesh cylinder of metal is revolved by water-cups on each side, the power being furnished by a hose attached to any faucet. The revolution of the cylinder shuffles the prints and provides a eomplete washing as they are dipped below the level of the water contained in the lower part of the washer. When the work is finished, the cylinder can be easily lifted out and the prints removed. At intervals of several days, when dirt has settled in the bottom of the container, the water can be drained off by removing a stopper in the bottom. This print-washer provides a way to han- dle numbers of prints without one’s hands in the water. When prints are washed with a single stream, itis necessary toshuffie them. Keep Your Small Metal Fares on a Safety-Pin INCE there is no coin between the nickel and the dime, railway com- panies that have raised their fare to an intermediate amount are constantly troubled with making change. It is not only difficult to obtain enough pennies to go round, but the conductors find their work more complicated. In Aurora, Illinois, the street-railway company has issued a small coin that represents the new eight-cent fare. You buy these coins by the dozen at a_ ticket-office. They are, however, very small, and you are liable to lose them if you carry them loose in your pocket. But since they are perforated, you can pick them up on a safety-pin, just as a woman picks up her stitches in knitting. An ordinary safety-pin will hold twenty coins comfortably. In the picture you see the coins ona pin. Each coin has an A plainly outlined on it. A in this case stands for Aurora. Thisis a suggestion that grocery and dry-goods stores might follow. A Maple-Tree that Braced. Itself REE surgeons sometimes find it neces- sary to brace brariches together with bolts and chains to give them strength to withstand the ravages of storms. It is unusual to find a tree that performs this feat itself. The illustration shows a red maple in which two separate branches grew into one, forming a natural brace. When the tree was young, two branches were sent out from the trunk at different angles. The wind rubbed these branches together, wearing away the bark until the growing inner layers were exposed. The two branches then grew together, form- ing a natural graft. Later the end of the upper branch died and the two became one. Making Roquefort Cheese AlMost every one likes cheese— especially good sharp cheese. Roque- fort cheese is a delicacy that has hereto- fore been manufactured only in parts of Europe where it was asserted the proper conditions for ripening existed. It was also asserted that goat’s milk was necessary for its manufacture. American scientists have disproved both of these contentions. Roquefort cheese has been successfully made in this country. Not content with making it in this climate, our scientists proved that goat’s milk was unnecessary. Cow’s milk will produce excellent cheese if it is properly ripened. It has been found that a room with con- trolled temperature, moisture, and air circulation is a good place to eure this par- ticular brand of cheese. Before it is placed in the curing-room, it must be perforated to permit air to circulate through it. This brings about a more rapid growth of mold, and more mold, better cheese. As the cheese grows old, the holes gradu- ally close up. Let the Screwdriver Hold the Screw HiXPERT workmen can practically com- plete the operation of driving a screw with one hand. Most amateurs need both hands and even then they do not get the screw in straight. For the benefit of amateurs and those who have but one arm the new screwdriver has been invented. As you see, the driving end has a curved metal attachment. Its job is to hold the screw in the proper position for the be- ginning of the drive. The attachment is so . curved that it is of double thickness at the bottom. The lower section is open so that the head of the screw can be inserted. The upper section has a hole in it through which the screw- driver can revolve. Both the driver and the screw are in the same straight line and it is impossible to send the screw in crodkedly if you hold the driver in a perpendicular position. The arms that grasp the - head-of the screw are curved . to fit it and are adjusted to hold it firmly. You must spread them in order to re- lease the head.

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The apparatus has two separable units. hydrogen generator. A Balloon Hydrogen-Generator that Goes on Wheels YDROGEN is extensively used for filling balloons as well as for other scientific and commercial It is true that helium, being incombustible and inexplosible, offers a distinct advantage over hydrogen, but it is a great deal more expensive and purposes. difficult to obtain in large quantities. In many cases the hydrogen is generated a long way from the place where it is to be used, and so it must be transported to that place, compressed in steel cylinders. But this method also is expensive, and is besides accom- panied with great risk. Long before the war, apparatus was invented to generate hydrogen on the spot. A new design of portable generator is mounted on a truck. The hydro- gen is generated by the action of a metallic substance like silicium on a hot solution of sodium hydroxide in water. Another truck mounts an engine driven by a pump which sup- plies the generator with water and is used only in cases where no direct supply is available and the water has to be pumped from a river or pond. The gas is cooled and puri- fied by passing it through water; it is delivered with a purity of ninety-nine per cent, free from poisonous substances and admixtures. The temperature reached in the reaction is 110° Centi- grade, and the apparatus functions without refilling for a period of fifty or sixty minutes. No fire for heating the apparatus is necessary, and therefore there is _ practi- eally no danger of ignition or explosion of the gas in case of a collision. The apparatus, which re- quires three men for its operation, begins to supply hydrogen a few minutes after the starting of operations. One truck contains the The other truck mounts an engine siphon. SOLENOID) + MAGNET J WATER —~ SUPPLY i ENGINE-| PIPE ROOM DIAPHRAGM VALVE a? LAMP Popular Science Monthly An Automatic Steam Siphon SUMP hole in a mill building was drained by a siphon located in the engine-room. The engineer was a for- getful chap and often neglected to stop the siphon. result, the basement of the mill was continually flooded. The trouble was overcome by making an automatic system. A float was placed in the sump. to a certain point a switch closed a circuit containing an electric solenoid. The solenoid opened a valve on a small water-supply pipe which caused water to flow into a diaphragm valve controlling the steam passing through the In this way the steam supply to the siphon was cut off and a flooded cellar prevented. Asa When the water rose The use of this electrically controlled steam siphon pre- vents a cellar from becoming flooded Enter, the Movable Electric Furnace HINA that is not hand painted— how does it get its pattern? In an oven, we find; the pattern is baked on. An electric furnace that can be used for this purpose is shown here- with, It is small, but very strongly built. The oven is mounted on steel casing, and its walls and door are thoroughly insulated, thus preventing loss of heat from radiation. Mounted directly above the oven are the switches that control the heat- ing. There is a main-line switch, a double throw switch for high and low This movable electric furnace may be small, but it can harden and temper tools, bake vitreous enamel, and heat carbon steel 50 heat, and a red pilot light that acts as a warning to the operator when the furnace is on high heat. After the switch is thrown on, maximum heat can be reached in an hour and three quarters, and a very even distribution is maintained at all times. There are connections at the side of the control-board for attaching re- sistance-boxes when temperatures as low as 300° Centigrade are required. The furnace can be used for any number of things—for example, heat- ing carbon steel in tool making, baking vitreous enamel, and harden- ing and tempering tools and dies. It is very easily oper- ated; there is a shelf in front for the convenience of the operator, and the door is equipped with counter- weights to keep it in position when opened. Apart from the advantage of size, this oven has other qualities. It has eliminated the fumes, noise, and smoke of the old-time furnace, and also its numerous gas-pipes. The use of the pilot light largely eliminates damage to the material that is being baked. It is perfectly safe to go away and look after other business, if the oven is left at low heat. a, I

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How the Blind May Read with Their Ears ate Gh, ane ee . . Shae eS a. buy + ampan ngof Light Spots aay Sounding. Notes e © Popular Science Monthly T= optophone enables blind people to read directly from printed matter. It was invented by E.’Fournier d’Albe. A thin beam of light is projected upon a letter of a word to be read. This beam is broken into five smaller beams by a revolving perforated disk, which also interrupts the individual beams. The beams are interrupted with various frequencies to correspond with five musical notes. The optophone makes it possible to hear the interruptions. This is accom- plished with a selenium cell. Selenium possesses the peculiar property of changing its jo "v a Sustained Drawing by S. W. Clatworthy electrical resistance under the influence of light. The five light beams are reflected from the printed letter to a selenium cell which results in interruptions in an electrical circuit con- taining a pair of telephone receivers placed over the reader’s ears. When the light beams strike a letter, some will be reflected to the selenium. The various combinations formed depend entirely upon the letter’s shape. This changes the sound heard in the receivers. Each letter produces a different sound, so there will be as many sounds as there are letters in the alphabet $. rs area: a ee ietogcte. etieneooe eT

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2 < ve all

An aged vessel is filled with cement and sunk to form part of a breakwater Converting Old War-ships into Breakwaters - IVE us the old discarded battle- ships,’’ say the people who live in the coast cities of England. Why do they want them? Of what use is a ship whose days as a fighter are past? From the war-ships that are no longer serviceable on the sea, all of the equipment is removed that might be still of service. The hulls of the ships, filled with stones and concrete, are then towed to points along the coast where breakwaters are needed, and sunk. Thus the discarded war-ship forms an efficient breakwater. A vessel such as the obsolete Prince George, after twenty-five years of use- fulness, will continue to guard the coast, but in this new capacity. The ship will make a breakwater 390 feet long. Popular Science Monthly The Flag that Never Wavers in the Wind AILROAD accidents are usu- ally due to improper signaling —flagging, for instance. The flag is often mounted on a stick thrust into the ground beside the tracks. The wind blows it down, and the en- gineer is unwarned. Alexander Currie, of Sorel, Can- ada, has invented a flagging signal that can’t possibly go astray. It consists of a metal rod mounted on a base that can be clamped securely to any track. The rod is made in two telescoping sections. The metal flag is bolted to the top of the rod and is at right angles to the track. The whole signal can be packed, carried to the track, and set up ina very short time. /

‘ll RAIL CLAMP HINGED JOINT

No accidents due to false signals can happen when this new signal is used Tools that Released Men from Prison HREE desperate criminals escaped from the Charlestown State Prison at Boston, a few months ago, by means of an ingenious con- trivance that they had manufactured in the prison shops. One of the escaping prisoners was a mulatto, and it was afterward dis- covered that this man possessed an almost diabolical cleverness in the handling of tools. It was he who manufactured the apparatus pictured on this page, which unlocked a cell door the lock of which was out of reach of the tallest prisoner. This me- chanical device is regarded by prison officials as the height of ingenuity. It was an improvised piece of mechanism made up of more than a score of parts, and perfectly put together. Its body is a rod an inch in diameter and one and a half feet long. The “head’’ contained a loose part, semicircular in shape, through which was a neatly carved groove. Into the groove projected a screw that was used to keep secure a key when placed in the groove. The whole part at the ‘head’ was controlled by a piston at whose end was a thumb-

The contrivance, made of parts stolen from the prison shops, that unlocked a cell door and released three desperate prisoners 52 presser. One press allowed the part to revolve. The device was unquestionably of prison make, many of the parts being recognized as coming from various workshops in the prison. A trusty aided the three convicts in making a getaway. Cleverly arranged dummies were left by each man on their cots, so that guards passing their cells would suspect ~ nothing even though the convicts were then making their escape. The police officials de- clare that there isn’t an institution in the world, or an organization within an institution that is in- fallible in preventing the escape of such men as these. Not one of the men has ever been cap- tured. Popular Science Monthly

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November, 1920 The Automobile with a Rotary Valve It will eliminate all valve-grinding and many valve troubles By Stanley Yale Beach HEN casting about for something interesting with which to busy himself after per- fecting his process of acetylene welding, Mr. Eugene Bournon- ville, a Belgian, conceived the idea of using rotary valves on automo- bile engines. At the time, James W. Tygard was the only one, so far as the writer is aware, who had successfully applied a valve of this type to a gasoline engine, and he used a special tapered valve in a freak motor. Bournonville set out to produce a valve that could be used on any standard automobile engine. Because of his knowledge of the action of metals under different degrees of heat, Bournonville pos- sessed a distinct advantage over others working in the same line. He used a single valve extending across the top of his four-cylinder motor, instead of individual tapered valves such as had been used before, but the problems of attaining gas tightness and of lubrication of this long straight valve were by no means easy to solve. To carry off the heat as much as possible, Bournonville used a tubular valve and passed the cold gas from the carburetor through it from the middle to each end. There it made a turn and entered the intake manifold or passage in the water-cooled valve- casing. The exhaust ports were on the opposite side of the casing, and ports in the cylinder heads were con- nected with the intake or exhaust ports at the proper times by means of cut-away portions of the periphery of the valve. Instead of a camshaft with cams that lift as many as four valves to the cylinder in ordinary modern motors car with explanatory details of installation November, 1920 - The inventor of the rotary valve at work on his own automobile, which is equipped with one. Mr. Bournonville is demonstrating that the valve can be removed and replaced in a few minutes GAS CONDUIT gq~_ THROUGH TWO-PART VALVE FIRING The detail at the top shows how the valve is turned. The various positions of the valve at the time of intake, compression, firing, and exhaust are made clear. Notice the water jacket around the rotary valve. The arrow indicates the direction in which the valve turns CYLINDER PORTS Showing the opera- tion and construc- tion of the new rotary valve. At.one ~side the long, slot- shaped ports are shown. The oppo- site end displays the corresponding depressions in the face of the valve EXHAUST PORTS iN CASING ae GASINLET eM PORT ~_ eee (the two exhaust valves being raised against the very consider- able pressure of the burning gases and thereby absorbing power), we have here simple rotary motion with instant and full opening and closing right in the center of the hemispherical cylinder heads. The result is a full charge and complete evacuation of the burned gases. Thus the motor always gives the maximum efficiency — the most power, the highest speed, and the greatest number of miles to a gallon of gasoline that it is possible to obtain. : Because of its great flexibility, a six-cylinder motor is practically vibrationless and as smooth-run- ning as a “twin six,’’ and a four- cylinder quite as good as an ordi- nary six. The numerous valves of an ordinary multiple-cylinder en- gine are displaced by but two rotary valves, and these never have to be ground or adjusted in any way. Valve trouble is thereby eliminated entirely. A very reliable air-cooled motor is all that is needed to make aviation as great a sport and business as is auto- mobiling, and such a motor will soon be developed from the air-cooled automobile engine. Because of its internal cooling from the cold gas, the Bournonville rotary valve is pecu- liarly adapted to air-cooling. Evena water-cooled motor runs much cooler with this valve. The engine pulls. at slow speed when climbing a hill, with much the same strength and tenacity exhibited by a steam-engine. The spark can be advanced fully at any time without stalling the engine or causing it even to “knock.” Its per- formance in this regard is remarkable and unexplained. EXHAUST WATER, JACKETS CONDUIT IN CASING Eg WATER GAS CONDUIT IN VALVE - EXHAUST PORT ie

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Popular Science Monthly Gathering the Morning Coffee Long before you drink it There are hundreds of coffee- These are ripe coffee-berries ready pickers on a large plantation. They to be plucked. Two seeds, or beans, pluck the ripe berries from the are found in the yellowish pulp in- trees and gather those that have side each berry. Two methods are already fallen ‘ generally used in Brazil for remov- ing the seeds—the drying method and the washing method At night the drying berries are swept into piles and covered to prevent the night moisture from spoiling the day work of the sun. When the berries are thoroughly dried, the hard beans within are easily removed After the coffee-berries have been mashed, they are dropped into a second tank of water, where a steady stream soon separates the pulp from the seeds. The pulp floats off, and the seeds, or beans, settle to the bottom els ae The berries are laid out on dry- ing-flats, and natives constantly stir them with brooms so that they will be thoroughly dried. Don’t mind the bare feet—the beans are still inside the berries The washing method removes skin and pulp. The berries are dumped into water and the mature ones sink. They travel through pipes to a pulping- machine, where they pass be- tween a roughened revolving cylinder and a curved iron plate, emerging in pulp form l= = a = P.O

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November, 1920 Smoking Makes the Whole World Kin How our neighbors prefer the weed These aged Korean shop- keepers sit and smoke and smoke all day—except when a customer arrives. The Korean pipe ‘is so long that the bowl rests on the ground. In shape they are not unlike the old English church- warden pipe She has just joined the old ladies’ pipe-smoking club of Liége. She car- ries her own pipe and to- bacco to the meeting and, between puffs, talks about the good old days, before the war, when the H.C. of L. was unknown Se white cheroot— Bokumbi village, Belgian Congo, is the home town of these three blacks. They very obviously be- long to the leisure class. The bowls of their pipes seem ridiculously small in comparison with the stems, but the smoke apparently is satisfactory 55 ” r \ ——T «? . f. - * ais 4 ‘ ‘ Yer ioe ‘An’ I seed her fust a-smokin’ of a whackin’ That’s what Kipling said about the Burmese girl on the road to Manda- lay; and that’s how we see her in the picture above, resting in the woods ry \ N In Bethlehem, Palestine, the women have coffee every morning and afternoon, and smoke the hookah. It is a pipe with a long, flexible stem and a water-tank attach- ment. The smoke is water- cooled before reaching the smoker’s lips = an ee oe y re ee

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Popular Science Monthly It Took Nerve to Do This Job What Washington thought of O’Hara is told in this true HILE Davis was melting ice on the wireless antenna, Zeider was having a chat over the signal wire with Hoke Fitzsimmons in Wash- ington. O’Hara, the fun-maker of the trio, was telling Davis how to do his job. “Zeider,”’ Davis said, “I believe our bold shipmate thinks he knows some- thing. To stop his chatter, ask Hoke what the Washington gang think of him.” Davis, Zeider, and O’Hara are chief electricians in the navy, attached to the powerful navy transatlantic radio sta- tion. The wire Zeider was working led from a place we will call Danapolis to room 2628, Navy Building, Washington. It was the latter part of January. For weeks it had been neces- sary to interrupt the _ send- ing of radio to melt ice on the antenna. To melt the ice, the radio- sending machinery was discon- nected and the antenna was con- nected with an ordinary electric current. This current, however, was a little too heavy for wires of the size of the antenna to handle properly. It caused the wires to heat and melt the ice. Davis was sending as much electricity through the antenna as the wire could handle without blowing out his current-breaker. “‘Here’s the answer,” Zeider shouted. “‘O’ Hara—is—tfull—of—pep— like — an — admiral’s —- aid — and-—he—would—be—all right ae if ve 99 Just then Davis’s ice-melting circuit-breakers went out with a bang. They all hurried out into the fog and rain. Looking aloft, they saw the cause of the trouble. The an-. tenna wires were supported by steel cables stretched between the tops of the six-hundred-foot towers. These cables were not in the ice-melting circuit. They had become coated with ice, and the additional weight had forced them down, allowing the antenna which they supported to sag so low that it touched a lead-in wire and made a short circuit. Zeider had been sending suffi- cient current through the an- tenna to heat up about ten miles of wire. When the antenna wires touched the lead-in wire, this cur- rent changed its course and es- story of two naval radio By John W. Kean caped by a short cut to the earth, causing the explosion. While the antenna wires touched the other wire the ice-melting circuit was out of commission, but—and this was more serious—the station itself was dead. To put the station in commission it would be necessary for two men to climb to the top of the northeast tower and cut the wire that was touch- ing the antenna. O’Hara and Zeider were detailed to cut the wire. To save time they de- cided to carry up a plank, instead of employing a pulley and rope. The rungs of the ladder were coated Several times O’Hara’s hand slipped from the icy rung, but he was steadied by the plank held solidly by Zeider. It took the place to them of the mountaineers’ rope 56 operators with ice. O’Hara went first, holding one end of the plank. With his left arm around the plank, he grasped a rung with his left hand, and reached up with his right to the next rung. He then moved his left hand up a rung. Scraping his feet on the rungs to get a secure footing, he made it fairly safe for Zeider. The fog gradually hid the station and the bay. A fine, misty rain was falling. The plank was becoming slippery. The gloves on the men’s hands also became slippery. The plank, while a cumbersome and dangerous article to carry up the icy ladder, also proved a help. Several times O’Hara’s hand slipped from the icy rung, but he was steadied by the plank held solidly by Zeider. Five hundred feet up, the rungs grew more slippery. They had to stop while O’Hara jarred the ice to loosen it before taking hold. The plank also was be- coming covered with a thin coat- ing of ice. Away out on Chesa- peake Bay a steamer picking its way through the fog blew its mournful whistle. They stopped for a moment for breath. After what seemed an eternity they reached the top. It was now necessary to fasten the plank to the tower, with one end extending about six feet. Balanced on top of the spider web of steel nearly a hundred feet higher than the Washington Monument, O’Hara and Zeider finally succeeded in getting the slippery plank fastened. O’Hara then crawled out on his stomach to the end of the plank to eut the wire. SLOWLY he felt his way along the plank, testing it as he went along to see if it would hold. The plank held, but before starting to work he called back: “‘Zeider, what do you suppose he was going to say about me?” “For heaven’s sake, man, cut that wire!’’ Zeider said. , Working slowly, O’Hara sev- ered the wire. They left the plank and hurried to the ground. In the power-house O’Hara, with a foolish smile on his good- natured face, said to Zeider: “Ask Hoke what Washington was going to say.” “O’Hara — would — be — all right —if —he—had—some— nerve!”’

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‘ rope to the drown- ar November, 1920 He Revolutionized Lumber-Drying Harry Tiemann, who helped win the war By Samuel J. Record HEN the United States joined the great fight, millions of gun- stocks, thousands of artillery wheels and transport wagons, as well as the proposed super-fleet of airplanes, called immediately for lumber; and not lumber merely, but dry lumber. Dried, too, in such a way that its strength and elastic properties would not be im- paired. Orders were issued for millions upon millions of feet of lumber while ‘‘the birds were still singing in the trees” whence it was to come. Our reserve stocks of dry wood had been drained by our allies. The time-hallowed method of curing oak, walnut, and hickory was to expose it to the air in open sheds or protected piles for from two to five years. There was no known method in general use for hastening the process without endangering the strength of the wood. Boards, shingles, and other thin lumber of the less refractory kinds had long been dried successfully in kilns with artificial heat; but stock of the kind and sizes for army specification might literally be torn to pieces by such treatment. With the coming of the war, manu- facturers realized that they would have to abandon the only way they knew of drying wood. Somehow they must make their dry-kilns do the seemingly impossible. They tried and failed. The Government's Need Anticipated At their wits’ end, they turned to the United States Forest Service. Little did these manufacturers realize that on the staff of the Forest Products Laboratory at Madison, Wisconsin, was a man who had anticipated their problem years be- fore and had evolved the formula for its solution. This man had discovered the secret of drying wood quickly, thoroughly, and without injury. It only remained to adapt his principles to a given set of con- ditions. It was asa ing. Who is this man? Harry Donald _Tie- mann, a government employee of seven- teen years’ loyal service. Of modest 2 dl Ie Lal» and retiring disposition, he has been content to slave for an ideal, with little thought for personal gain or advancement. His patents have been generously dedicated to the public, and they yield to the inventor not a cent of royalty. Within a narrow circle he is known round the world, and his kilns are being erected in the remotest corners of the earth. How did he acquire his experience? In 1897 he received the degree of Mechanical Engineer from Stevens Institute of Technology. For a time he taught chemistry at Pratt Institute, in Brooklyn, and later was instructor in mechanical engineering at the Uni- versity of Pennsylvania. This work was not exactly to his liking, and in 1901 he enrolled in the newly estab- lished School of Forestry at Yale, graduating two years later. It was at Yale that the opportunity came to him to combine his training in mechanics and chemistry with a knowledge of woods and a realization of the future needs of the lumber industry. From 1903 until the autumn of 1909, when the Forest Products Laboratory was established at Madison, Mr. Tiemann had charge of the Yale Tim- ber-Testing Laboratory, conducted in cooperation with the United States Forest Service. For six years, in the basement of Marsh Hall, he applied himself to a single problem—wood in re- lation to its moisture content. Thou- sands of different specimens—green, water-soaked, air-dried, kiln-dried, boiled, and steamed—were broken or crushed in testing-machines and the re- sults carefully analyzed and tabulated. His work at Madison has _ been largely a continuation and an amplifica- 57 Harry Donald Tiemann saved us from a serious lumber famine when we entered the war tion of that at Yale. Experimental kilns were erected in which the tem- perature, the humidity, and the cir- culation of the air were under accurate control, and where every stage of the drying operation could be closely followed. Controlling the Drying Process Mr. Tiemann’s great contribution was the control of the drying process by the regulation of the humidity in the drying-chamber. He designed and patented his own type of kilns to accomplish this purpose. _ In addition he was able to modify existing types of kilns quickly and cheaply so that they would approximate the results of his own. In these kilns black-walnut gun- stocks for army rifles were dried from green condition in sixty days, with a loss of only a small fraction of one per cent. Wheel stock of oak, ordinarily requiring from three to five years to sea- son, was turned out in perfect condition in ninety days. Wing- beam material for airplanes was dried fresh from the tree in from twenty-four to thirty days, and was in better con- dition than the same material air-seasoned for a year or more. It was thus that Mr. Tiemann averted a famine of dry lum- ber when dry lumber was indispensable to the nation’s success. He has complete- ly revolutionized Mr. Tiemann is here shown instructing a class of manufacturers in his new quick the lumber-drying method of drying lumber. The wood dries quickly, yet does not lose its strength process. Li A OOO CII SO > TE . NT PE aa zx aa = or en see ee ne ae | HW

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Now there Is a Double-Ended Vacuum Cleaner OW there is a vacuum cleaner that not only does your sweeping for you but dusts as well, without the need of any special attachments. The handle is equipped with a suction device; thus when you wish to draw the dust out of corners or from upholstered furniture, you hold the cleaner upside down and let the handle do the work, as shown in the picture above. Inside the cloth dust-bag there is a paper bag which is easily removed and replaced when filled with dust. Thus the dirty and insanitary method of shaking the dust out of the cloth bag is eliminated. The passageway through which the dust travels into the bag is transparent and you are able to see whether the fan is working properly or not. Light up the Trench Hat ON’T hang your old trench helmet in a closet where no one can see it; hang it rather from the ceiling and use it as an inverted-light fixture. You can buy a reflector that will fit inside when the lining is taken out. In place of the chin-strap you attach chains with which to fasten the hat to the ceiling. The wiring is done as usual. : Inverted lighting is considered much bet- ter for the eyes than direct lighting. At first only transparent globes were used for the purpose, but now metal ones are also used. Trench helmets also make good flower- pots, saucepans, or fish-globes. If you brought any of them home with you, dis- tribute them around the house, and if you have an extra one, put it in a tree for birds to live in. Our Ears Deceive Us in Locating Sound CAN we judge the direction of loud and soft sounds of different pitch with equal accuracy? Experiments have shown that we can not. Blindfold a man and mark off a circle in ten-degree divisions around him. Start a sound in a certain part of this circle, but vary its intensity. Experimenters have found that the blindfolded man is deceived when the displacement of the source causes the sound to reach each ear with different intensity. He seems to hear a “phantom” sound which rotates horizontally around him as the intensity varies, when the vibrations are as slow as 256 a second; but with a frequency as high as 1024, the effect changes and sometimes disappears. Moving the source of sound around the circle so the vibrations reach the ears from different angles, at 60 degrees dis- placement with 256 frequency, the observer hears the sound as though it came from 6.1 degrees. Popular Science Monthly A Pair of Trouble Gloves for the Automobile Driver you wear high rubber boots when you wish to plow through heavy snow, why not wear long gloves when you have to dig through the mud and grease that accumu- late on your car? You never know when you may have to change a tire, or adjust your carburetor, or tend to any other of the many ills that cars are heir to. If you have a pair of long gloves like those above, tucked away in the pocket of your car, you need never worry about soil- ing your cuffs or sleeves when trouble occurs. With overalls under the seat and long gloves in one of the pockets, you can wear your best clothes on a trip and know that they will be in no danger of soiling. With an extra pair of these gloves you need have no hesitation in calling upon others for help. Use a Motor-Sled in Flat Country NLESS some one has been willing to drag you around, you haven’t been able to do much sledding in flat country. But now that the motor wheel has made good on bicycles and small boys’ express wagons, it is being tried out on sleds. Above you see a motor- sled chugging its way across the smooth hard snow. It is able to attain a speed of more than twenty miles an hour. Thus before long we shall have a new type of speeder brought into court. The motor wheel is attached to the front of the sled by means of a special wooden frame. Ski-Sailing for Two in Modern Norway PEED—that’s the secret of many sports. Take skiing, for instance. Even though skis carry you across the snow at a terrific rate of speed, many skiers are not satisfied. They want to go faster. How can it be done? By wearing a sail. Above you see some people starting on a ski-sail in Nor- way. One sail is used by two people. They put their arms through a bar across the middle of the sail and in this way they are able to guide it. Even a slight breeze will have a marked effect on : the speed of the skiers. a: a St ae Se

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November, 1920 Shaving with a Side Motion ERE is a _ razor whose _ blade moves from side to side as you draw it across your face. This double motion doubles the speed and accuracy with which each individual hair is chopped off. Thus it should not be necessary to scrape your face more than once when you shave. The side-to-side motion is caused by a small roller connected with the blade. The roller touches your face as you draw the razor across it and its revolving motion is imparted by cams to the blade. You can adjust the guard that holds the blade so that it will give you any kind of shave you desire. Providing a Street-Car with Stilts to Keep People Dry HEN the floods from the Ohio river inundated some of the streets of Cincinnati, a unique arrangement was made to keep the high water from reaching the exposed parts of the street-car motors. The car which held the motive apparatus was mounted higher above the wheels, thus elevating the motor out of reach of the water. In front of the short car containing the motive power is attached the car in which the passengers ride. When passing through parts of the flooded district, the water reached the: floor of the passenger-car. Then the passengers had to stand upon the seats to ke2p their feet dry. Cincinnati is probably the only city in the world where this has been tried. Lamps Under the Chair Keep Him Warm B4? boys in Sunday supplements and movie villains are always building fires under other people’s chairs. But none of them had anything to do with the two lighted lanterns that blaze away beneath the ticket-chopper at the Times Square, New York, subway station, whose picture is shown here. He put the lanterns there himself, to keep from freezing on the job. He tucked his feet in a box lined with newspapers, sat on more newspapers, and leaned against still more. Thus he protected himself against one of the bitter cold shocks that New York is heir to. This ticket-chopper is not the first per- son to realize the warming properties of newspapers. For years past housekeepers have spread newspapers under mattresses and carpets to keep drafts away; even between blankets, when bed-coverings were scarce. Also as chest-protectors, newspapers are most satisfactory. © Kadel & Herbert A Champion Among Goldfish ¢( LD Black Joe has a namesake—a German-born goldfish that has been living in this country seventeen years. He-was given that name because of his coal black color; but, strange to relate, when the United States entered the war with Germany, his color changed to red, white, and blue. Old Black Joe, the fish, is worth more than a thousand dollars and he is the champion of the goldfish world. He belongs to the broadtail telescope class and, in spite of his eighteen years of life, is still full of vigor. Our Black Joe is the father of over a million children. His owner would not sell him at any price. Hitch Your Skis to a Motorcycle and Travel Fast KIING is a thrilling sport at the least attempt, but when it is connected with various other motive sports it surpasses the mere sensation of thrills and enters the realm of real danger. One of the least dangerous is the cele- brated sport of the hills of Sweden and Norway. Old Dobbin is hitched up suit- ably and furnishes the fun for “ski- joring.” ; But the gasoline engine thumping away in the frame of a motorcycle affords an element of speed that tugs at restraint. In a cloud of fine snow-powder the motorcycle guides the man on skis. He cuts through ruts and skims the surface of the snow. If he is skilful, he remains upright to the end of his journey. © Keystone View Co,

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Popular Science Monthly Looking at the Ocean’s Floor HE bottom of the sea is undiscovered country to most of us who are not deep- sea divers. Now, however, there is a sea telescope that makes it possible for us to see clearly from the deck of a boat, objects a hundred feet below in clear water. It was invented specially for fishermen and salvage workers. The tube is enclosed in an opaque cover- ing and has at its lower end a circular plane glass. There are two eyepieces with elastic rims at the opposite end of the tube. These fit so closely around the eyes that all light is excluded. Since the plane-glass end is in direct contact with the water, no distortion takes place. Watch now for the man who charges a dime to look through the sea telescope. Banana Skins Can Be Used for Cleaning Shoes BANANA skin has a bad name, owing to its unpleasant habit of making peo- ple slip. But it is really quite useful. For example, it will clean and polish your shoes just as effectively as a regular shoe-polish. You rub the inside of the CLOSING EXTRACTING SPREADING THE ENDS THE PIN THE ENDS A Tool for Manipulating: Cotter-Pins HE legs of cotter-pins are often hard to open and close; but there is now a tool to attend to this. There are two handles, pivoted together as in the case of a pair of scissors. One handle has a hole grooved out near the end, and the other terminates in a pyramid-shaped point that fits in the hole. Suppose you wish to spread the legs of a new cotter-pin. You slip the legs through the hole and force the point between them by pressing on the handle. An Automatic Fire-Door AFETY curtains, fire-doors, and all other devices for preventing the spread of fire, should be made to work automati- cally. In the confusion and excitement that accompany fires these devices are often overlooked. In the picture below is shown a new automatic release attached to a fire-door in a factory. If the temperature should rise fifteen degrees a minute, as would happen in case of fire, the air would expand so rapidly that its pressure on a diaphragm in the device would cause a plunger to be- come disengaged. Whereupon a cord attached to the door, and on which a weight hangs, would be released. The door would close instantly. Removing Old Paint Quickly EMOVING old paint with a gasoline blow-torch is a tiresome job. Such work is made more pleasant and rapid with this new torch that burns acetylene gas. The gas is supplied from the dissolved- acetylene tank which rests on the ground. It is connected with the blowpipe by means of a flexible hose of sufficient length to allow the operator freedom in his work. The flame is extremely hot and therefore it is not necessary to hold it in contact with the paint very long. This enables a painter to cover a greater amount of surface. The flame used is so hot that the paint on a canvas surface can be heated and removed before the fabric underneath becomes hot enough to burn. It Keeps the Low Shoes from Slipping Up and Down N? matter how well your low shoes fit, they are likely to slip up and down on your heel when you walk. It isn’t the shoes’ fault; they simply are not as flexible as your feet. What will give then this flexibility? A strip of elastic. You fit it inside the shoe and fasten skin on your shoe and the sticky substance there will absorb all the dirt. After it has dried on the shoe, you take a rag and rub it off. Your shoes will then be clean and shiny. But of course if you don’t happen to want a banana at the time when you want a shine, it | would hardly be worth your while to buy one just for the sake of the skin. Bananas are en- tirely too expensive these days. Winner vee ose ‘ COUNTER BALANCE it at each side of your heel. The strip should be slightly shorter than the inside measurement of the heel of the shoe. It will then fit snugly against your heel and move up and down with it, remov- ing that uncomfortable feeling of slipping. This will be a welcome hint to those who dance, owing to the tendency of pumps to slip up and down after they have been worn once or twice. WEIGHT ELASTIC LOOP Ponular Seienre Manthh, ey

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November, 1920 A. Speedometer for a Buggy GHOULD you see what looks like a speedometer attached to the axle of a buggy, like as not the vehicle is being employed by the Soil Bureau of the United States Department of Agriculture. When thus employed, the principle of the speedometer is converted into an “odometer.” It registers the dis- tance traveled in the course of a survey. The character of soil in one corner of a field may be different from that in another part. The distance be- tween the sections from which soil samples are taken can be obtained readily by looking at the pointers on the face of the dial. Steel Teeth to Cut the Ice AN engine which can push a steel-chisel ice-cutter serves well to keep open winter transportation. The sharp-pointed chisel-teeth dig deeply into the hard surface of ice, or the compact coating of frozen snow, and shove aside the broken pieces to clear the right of way. The invention occupies a place of distinc- tion apart from the service of a snow-plow. Rushed into a hard ice-field, the snow-plow is of little use. But the difficulty is over- come when the metal teeth of the ‘“‘ice- plow” crunch the glazed covering which a winter’s storm has cast upon the street-car or the railroad tracks. Focusing from Above with an Unusual “ Tripod’’ (5=T up into the air with your camera if you wish to take a photograph of merchandise for catalogue use. This camera “tripod’’ was built especi- ally for this purpose. Pictures can be taken quickly without the trouble of pinning the objects to the wall. The photographer stands back of his camera and brings it to a focus by adjusting the moving platform, up or down as the case may be. The photographer himself moves with the camera by manipulating the small hand wheel shown at his side. This is a great improvement over the old method of taking catalogue photographs by fastening the objects against a white paper placed on the wall. One advantage of this system is the ease with which the articles can be moved about. A Hard Helmet to Crack INERS, structural steel-work- ers, and others who jeopardize their heads by working in places where rock, coal, or pieces of iron frequently fall, can find protection in the new “hard-boiled” cap which serves the purpose of a helmet. The cap is made of stiff material capable of withstanding a blow equal to that of a twenty-pound rock falling six feet—a pressure of four hundred pounds. It is water- and fire-proof and is a non-conductor of electricity. A twenty-ounce bolt fell forty feet, struck a man’s head, knocked him down, but left him unhurt. Many a fractured skull can be prevented by the wearing of this helmet. Carrying Gasoline on the Farm HEN one’s tractor or gas engine is in use a mile or so from the house, and the “‘gas’’ gives out, it is not always easy to carry the supply across the plowed fields. To meet this need of farmers a new form of tender has been placed on the market. On two light but strong metal wheels are mounted steel drums in which to store gasoline, water, lubricating oil, ete. These drums are so constructed that when being transported they stand upright, on the wheels, but when gasoline is needed they can be tilted over so that the liquid will run out of the faucets, with which each tank is equipped. November. 19290

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Popular Science Monthly A Little Tank with a Big Job [Ff you think this little tank is a toy, you are mistaken. It is a real worker—a hard worker. It is well constructed, has plenty of power, and, although a little slow, like the snail it finally gets there, even though pulling a heavy load. It hasa gasoline motor, tractors, and everything. A one-eighth-horsepower motor keeps this machine going and supplies it with enough power to pull a load of several per- sons. When it is pulling a heavy load, a man must stand on the back to give it sufficient traction. Otherwise, the tractors would merely slide over the pavement. The con- trol levers are placed at the back of the hood that covers the engine, where they will be within easy reach of the operator riding on the small platform. An enterprising manufacturer con- structed this gasoline miniature tank to see how much power he could get into a small space. Elaborately Carved Human Interest Sign-Posts hE, VEN in their sign-posts the Germans display their love of elaborateness. Instead of having plain wooden or metal posts with arrows pointing to The Muff on the Carriage Handle BABY must have plenty of good fresh air. In the wintertime a mother’s hands get very cold on the handle of the perambulator. A humane inventor—very probably an experienced father—has in- vented a handle which will accommodate a muff so that the hands may be kept com- fortably warm while little son or daughter is enjoying the fresh air. One end of the handle swings on a pivot while the muff is placed on the opposite end. The handle is then slipped back into place, and mother goes on her way in comfort, regardless of the winter wind, snow, sleet, or hail. © Kadel & Herbert How Babies Advertise Milk HERE is no better advertisement for milk than a healthy one-year-old con- sumer. That’s why a London dairyman put four strapping young milk-drinkers in his show-window. If people will stop to look at puppies in a window, surely they will look at babies with a much greater interest. The mothers who so kindly lent thee children to the dairyman stand in the background, ready to grab them should they cry. But the children appear to be just as interested in the people outside as the people are in them, and they are not likely to let their emotions overcome them. One of the chief advantages of advertis- ing with animate objects is that they remain in the mind of the observer much longer than do inanimate ones, and have that much greater selling power, a fact that has not been overlooked by store- keepers and advertisers of all kinds. Protecting the Traffic Man with a Windshield HILADELPHIA comes to the front with a humane device to protect traffic policemen. Exposed to the bitter winds of winter, the traffic regulator has the various towns, highly carved tree-stumps are used. They are fashioned to represent human beings with extended arms— the arms pointing to the various towns, and having the distances written on them. Some of the sign-posts smile at you; others frown. Perhaps they are trying to tell you the kind of road that’s ahead. A cheerful sign-post is shown to the right. A schoolboy hugs to his bosom his slate on which is written the name of the next town. He smiles at you sweetly and points toward the town, regardless of the fact that point- ing is considered bad manners. The stump on which he dwells is a tall one and makes you think, at first, that the boy is wearing long dresses. These mileposts are only one of the many curious things that travelers through to keep a sharp lookout for offenders who do not obey his orders. When the wind, full of ners of his eyelids, it is not an easy matter to keep a clear vision. If aviators and chauf- feurs had to drive unprotected against the wind, there would be far greater danger to: them- selves and to others. But windshields enable them to bear the brunt of the wind easily. Based on this plan, the traffic policemen of Philadelphia are equipped with a windshield sufficiently large to protect their eyes. Apart from the additional comfort experienced by the user of the windshield, those who drive and those who walk, receive that much more efficient service from the man Europe are continually seeing. © Ledger Photo Service who makes streets safe. a) ee ice-crystals, cuts into the cor- “ No a a y v c k k I ie Se ee le ee

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November, 1920 This Cork Cannot Escape Its Fate ” HERE is that . cork?” you ask, after you open a bottle and the cork slips out of your hands. The little wire handcuff on _ this cork keeps: it where it belongs—attached to the © International Film Co. Gloves that Were Struck by Lightning jon open your um- brella in a heavy thun- derstorm, even though it will mean ruining a new hat. Umbrellas attract lightning and may lead to injury or sudden death. bottle. It is very sim- ple. Above you see a mutilated pair of gloves that were A single piece of small- gage wire which has_ several bends does the trick. It can be used on a bottle of any size and it adds practically nothing to its cost. The cork is free to move the necessary distance to let the liquid out. The Trunk Bandit W eee is always a great trunk mystery raging as the history of crime goes on. One of the recent trunk affairs involves a burglar who had himself locked in a trunk by his confederates and shipped to a vault in a large storage company. In the dead of night he planned to creep out and take his pick of the valuable jewels and furs around him. But it so happened that he raised the lid long before the dead of night. Private detectives, who chanced to be present at the time, arrested him before he was able to get out. Below you can see the would-be bur- glar and the brave detectives who captured him. © Keystone View Co. The Return of the Four Bronze Horses of Venice EFORE the war, when you could tour Europe for a few hundred dollars, your guide would invariably lead you to the entrance of the church of St. Mark in Venice and point grandly at the four bronze horses at the entrance. But during the war the famous four disap- peared—they were removed to Rome for safekeeping. Now they are back again, none the worse for wear or war. It was not an easy job to move those horses. They had to be hoisted down carefully, then placed on specially built wooden trestles and dragged through the streets to the station. During their visit to Rome they stood in the garden of the Palazzo Venezia, the residence of the Austrian ambassador to the Vatican. The above picture shows them on the last leg of their journey—being hoisted back into place. A solemn service of thanksgiving was held in the church when the horses had once more resumed their rightful positions. worn by a woman who was holding an umbrella when lightning came her way. It ran down the umbrella handle, tore the gloves, and burned the woman badly about the head and shoulders. Lightning always seeks the earth, and umbrella handles are good conductors. Ostrich Eggs for Luncheon AN ostrich-egg omelet was prepared especially for the thirty-two guests of a film star at a luncheon recently given by her at a fashionable hotel in Santa Barbara, California. In arranging the menu, it was decided to have something in the way of a novelty to offer the guests. The star chartered an airplane and made a hurried trip to a famous ostrich farm, near Los Angeles, where two freshly laid ostrich eggs were secured at eleven dollars apiece. In the hotel kitchen the chef broke the eggs with a sledge-hammer. One egg just filled a large chafing-dish and proved to be similar in appearance to an ordinary hen-egg. 7 eae si ta

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Popular Science Monthly What You Can Do with Old Corks Instead of making considerable noise, corks now hush things up. | To prevent a window from pr rattling, bore two holes in the bottom edge and insert corks ter as shown in the picture on the left pe =—— or cel th pr ca in ti tk in p u J If the latch on the door of Automobiles are always develop- t your automobile is hard to ing new “‘canary-bird’”’ squeaks. € work, you are apt to lose The doors and windows are C your temper and slam it shut usually to blame. Two corks I hard. Why not soften the will take the squeak and rattle blow by applying corks? out of any of them ah Gn 06 tad If a ladder slips when you are on it, you will surely have to give up the pursuit of happiness for at least a week. A cork on each foot of the ladder will keep it firm and safe This ex-soldier must carry his crutch a long time. But he gets along very well, especially since he had the idea of attaching a cork to the end of the crutch to ease the jar Few things can be more annoying to sensitive nerves than a door that always bangs. That was a fault of the door shown above, until its owner fastened four small corks to the door-frame and in- sured quiet door-closing

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November, 1920 Keeping Up with the March of Seiwhice _ Facts for the.man who wants to know Dyed Sugar Just as Sweet HE appearance of “rainbow” sugar has brought about an investigation by the . United States Bureau of Chemistry. Harm- less dyes were found to have been used in producing the various tints. But the Department of Agriculture in- tends to keep a sharp lookout for the ap- pearance of other than harmless colors. It is continuing the testing of the “‘col- ored’” brands of sugar that are supplied to certain grocery dealers. It will also see that the sugar is not inferior, and that the prismatic tints have not been added to camouflage some defect. The Power in a Tree YOUNG man wished to measure the force that drives the sap upward in trees and shrubs. So he cut a vine and tied a bladder over its end. In two hours the bladder was . greatly distended, and inside of three.hours it burst with a plop, so great is: the force that drives sap - upward. lias Leads : M ORE money | is spent i in this country on tobacco than on automobiles! When you compare the price of a cigarette with the price of an automobile, you realize the enormous amount of. tobacco that must be consumed in order ° to. give~ the tobacco business the supremacy. Statistics gathered by: ‘the Treasury Department | show that two billion dollars is spent on automobiles in a year, whereas an extra two hundred million goes into tobacco. We spend one billion on candy and fifty million on chewing-gum. American Houses for France [% spite of the critical house shortage in our own country, builders find it ex- pedient to construct a thousand wooden houses for France. Five hundred houses have already been shipped in sections that will be put together when they reach their. destination. The windows, doors, paint, nails, and bolts go with each house. - When erected, each house will consist of three rooms and a shed and will occupy about twenty-three feet square. The houses will be erected in the Arras and Lens districts. A Dearth of Golf-Balls ‘THE golf-ball manufacturers are barely able to produce enough golf-balls to meet the demand. England,-for instance, used seven million balls this. year! It is twice the number that were used before the war. Orders for balls from Australia, Can- ada, Africa, and India have increased proportionately, and the United States has been able to secure a strong hold onthe market. Recognizing Real Midioneng b gcd buy a “mahogany” table, pay a good price for it, and then begin to wonder whether it is made of real mahog- any. Red gum can be made to look so much like mahogany, and Circassian walnut that it is often sold for one or the other of these woods. How can you tell the difference Siiloha the false and the true? By looking at the cross-grain; if you can see the pores with the naked eye, then you will know that all is well. If you can’t see the pores without the aid of a “magnifying-glass, then you will know that you’ are in the presence of red gum. = &. Even through anni _ the pores - of mahogany and walnut are distinetly visible. Mi 6S we How Carton Black’ a Made OW is caeion black made? By burn- ing oil or natural gas. _But the carbon obtained from gas is. much. blacker and better than the carbon from oil. Gas-burners are erected underneath steel channels that move back and forth. The carbon is deposited on these channels, but it is constantly scraped off by their movement against each other. Only 1.5 per cent of the total carbon in the gas is recovered in the form of black; thus the waste of gas is enormous. Scientists are now trying. to produce carbon from gas by mixing it with other gases without neces- sitating combustion. Rivaling the Sun Biv sun gives the earth a large part of the earth’s heat, but we inhabitants contribute to the remainder.’ Wilhelm Schmidt ‘investigated the warmth of Vienna, Berlin, and Potsdam, and he found that one sixth of the heat in Vienna was caused by earthly objects. In Berlin and ‘Potsdam the percentage was even higher —‘one third! In New York, the largest city in the world, the percentage is highest of all. In Vienna, the people, the animals, and the fuel burned give off seven billion kilogram-calories of heat in a year. The Average Hair Crop HE Bible tells us that the hairs of our head are numbered, but it does not tell us even the approximate number a square inch. But some one has figured this out for us. He counted the hairs in a square inch on many heads. On the average head there are a thousand hairs to each square inch. Find out the number of square inches in your scalp and you will soon know the approximate num- ber of hairs on it. We are also told that four hairs will sus- pend a one-pound weight. Therefore an average head of hair should be able to support the combined weight of two hun- dred people. Don’t try it. 65 . gins. How to Sleep W HT happens to your body when you sleep? First, your breathing slows down and your heart drops six or eight beats a minute. Then cellular repair be- The muscles, nerves, and tissues get new life; your whole body breathes more freely. >i When you waken you should feel refreshed. If you don’t, perhaps you have slept too long; or slept in a room not prop- erly ventilated. Eating heavily before retiring will also make you wake up tired. When you go to sein stretch out. If you draw your knees up under your chin your body will not relax properly. Small pillows and light bedding are also recom- mended. If you follow all these rules and sleep eight hours every night, you will wake up full of pep each morning. Seal Flippers Produce Glue EALS are out of luck now that fashion calls for sealskin coats. Many thou- sands of them are killed each year. And the flippers that heretofore have gone to waste are now being considered . possible glue-producers. The Bureau of Standards has recently experimented with some flippers and has found that they yield glue equal to sixty- seven per cent of their weight.. The aver- age weight of the four flippers of a seal is about eight pounds. Radiotelephony on the Farm WESwecan farmers who live far away from civilization will soon be able to know what’s happening in the big city at any time of the day. The Michigan Agri- cultural College has planned a system of wireless telephones to be installed on all the large far-distant farms. The Michigan farmer will be able to know at all times the market prices of his products. He will receive weather fore- casts and listen to lectures or music when he has nothing else to do. His equipment provides for receiving messages, but not for sending them. Wood Absorbs Explosives Bos and kegs that have been used for carrying explosives are often sent out again, unwashed. As a result many acci- dents have occurred. Black blasting- powder, for instance, is usually shipped in kegs. Even though the powder is dumped out carefully, some of it remains in the cracks. Should the kegs be used again by some one who knew nothing of the-former contents, an explosion might easily occur. Nitroglycerin will sometimes exude from dynamite sticks. If the sticks are shipped in a wooden box, the nitroglycerin is apt to be absorbed by the wood. Any box that shows the slightest stain should be de-

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stroyed immediately. All others should be well washed before they are sent out into the world again. Heat Reflection in the City “Ts so hot in the city!’” That’s what the suburbanites say when they go to town in the summertime. Why does it seem hotter in the city? Because of the pavement. The sun’s rays hit the side- walk and bound back in your face. If there are no trees or grass around to absorb some of the heat, the temperature is several de- grees higher than in the country. Engineers have taken the temperature at varying distances above asphalt, brick, and concrete roads, together with the temperature above a lawn in the vicinity. Results have shown a difference of several degrees. Whitewash Wood for Safety ONE spark will sometimes lead to the loss of thousands of dollars’ worth of lumber. Therefore it is essential that fire preventives be used whenever possible. The Forest Products laboratory announces that the most practical preventive so far discovered is ordinary whitewash. ’ A coat of whitewash will not necessarily keep wood from burning under severe con- ditions, but it will greatly decrease the danger of a blaze’s spreading. A single spark, for instance, would die a natural death in the midst of whitewashed wood. Nettle Fabric for Linen INCE Russia has been in a turmoil linen has become scarce; for Russia was long the world’s greatest flax-pro- ducer. Professor O. Richter of Vienna make: the proposal that the nettle plant be used as a substitute for flax. It is nota new proposal, but it assumes commercial importance just now because Richter has devised a process for treating the resistant nettle so that textile mills can spin its ' strong, tough fibers. A thread of nettle consisting of three fibers can support a weight of two and one quarter pounds. Preserving Explosives NDRE LEFEVRE, French minister 44 of war, also a distinguished chemist, recently startled the Chamber of Deputies with the proposal to store the French stock of guncotton and nitrocellulose explosives in one of the lakes of the Pyrenees. France has on hand about ninety thousand tons of high explosives, enough to last her three hundred battle-days, even at the enormous rate at which powder was consumed during the war. Explosives deteriorate with time. Chem- ical decomposition begins sooner or later if the mass of ‘explosive is not kept ata safe and constant temperature. The tem- perature of the water of Pyrenean lakes never varies more than four or five degrees. Hence M. Lefévre would sink France’s stock of war explosives in waterproof tanks in the lakes and keep them thus for decades. Fireproofing a Thresher HE dust in a thresher mixed with air may be as explosive as gasoline in an automobile engine. A tiny spark of elec- tricity is enough to fire the dust-laden air in a thresher. Hence insurance companies charge high rates for threshers—as much as eighty to one hundred dollars for each one thousand dollars’ worth of Property insured. What was wanted was a device to prevent thresher dust from exploding. It has been invented by. engineers of the Department of Agriculture in coopera- tion with manufacturers of threshing machinery. - Charges of static .electricity—the kind that you generate by. friction—are carried off by a special wiring system, which may be regarded as a miniature lightning conductor. Fire-extinguishers are attached to the separators... Thus the danger from explo- sion and fire is minimized. -Moreover, a fan is installed which cleans -the grain, particularly of smut. Hence the. smut spores cannot be disseminated by wind to infect wheatfields, as has been the case for many years past. Sodium Instead of Copper VV BEN Germany was hard pressed for copper electric conductors, von Bett, a physicist, suggested that sodium would be an acceptable substitute. The conductivity of sodium is about equal to that of zinc and about one third that of copper, but since the _ specific gravity of sodium is small, it is'a better conductor, weight for weight, than any metal. On the other hand, sodium has a very low melting-point and cannot be drawn into wire. - Moreover, it- cannot be ex- posed to the air. Therefore the experiment was made of filling thin-walled iron tubes, painted as a protection against rust, with fluid sodium. The experiment was successful. Whether or not such conductors as these can be introduced commercially, de- pends upon the possibility of drawing the tubes cheaply. Sodium is now made cheaply from common table-salt by elec- trolysis. Weeding Out the Unfit HE American army was the first in history that tested not only the physical fitness of a recruit, but his mental fitness as well: There were few feeble-minded soldiers in the A. E. F. Shortly before his death, Dr. E. E. Southard, of Harvard University, sug- gested that the same methods be applied to industry. If a man has been found unfit to fight because of his nervous and mental con- struction, he is probably also unfit to work under certain conditions. Every large, well-conducted plant has a staff of physi- cians to look after the physical well-being of the employees, but as yet no plant employs a psychiatrist. Southard succeeded in having men pass the regular physical examinations in plants, who were totally unfit for employment in 66 Popular Science Monthly difficult, positions. On the other hand, he was able to show many a grouchy, “queer,” and otherwise ‘difficult’? person how to make a living. Carry out Southard’s suggestions in plants and we will: have -.- fewer undesirable “‘floaters,’’ more workmen who own homes, and fewer ruinous strikes, Bacteria for Sausage Skins. GAUSAGE skins are usually made of entrails, but parchment paper and de- nitrated wood pulp have also been used. Now comes the daring proposal to make them of bacteria. The particular species of bacterium employed is called xilinum and is found in vinegar. Xilinum has been the dread of the vinegar-maker and manifests itself in an objectionable slimy scum. Some years ago a process was patented for converting xilinum bacteria into leather, and now a Dr. Wuestenfeld would use them in the making of sausage skins. Xilinum skin is obtained, of course, only in flat sheets. No one has _ succeeded in inducing xilinum to breed tubes. The sausage meat must be wrapped in the skin and then sewed. up. Can You Hear Colors? Out of twenty-five people who read this, at least one can hear colors. To hear a color seems about as ridiculous as to see sound; yet color-hearing is a phenomenon well known to psychologists. To a color-hearer a trumpet-note appears red, an oboe-note a brilliant yellow, and the bass note of a big brass instrument purple or deep green. Even names suggest hues to the color-hearer, probably because each vowel has its characteristic shade, What. is the explanation? Perhaps the optic nerve and auditory nerve touch each other at some place in the brain, so that the auditory nerve trans+ mits a sound to, the point of contact, after which the optic nerve is excited. Metal that Lilbricates Itself E feswes One hy of bearings is necessary in order to’ prevent ‘‘hot boxes” and “seizing.”” Two contacting metals in motion ‘‘seize’’ when the ‘microscopic hills in the one mesh with the microscopic valleys in the other. It is the function of the lubricant to keep the metals apart. Now comes an inventor with a metal which will run hot and which will not “seize’”’ because he has found a way of combining graphite with it. This is prob- ably the first time that any one has suc- ceeded in combining a non-metal with a metal. An alloy of aluminum and graphite gives better results than the usual phos- phor-bronze-bearing alloy at the same speed and pressure. Must the Cat Go? R. A. K. FISHER, of the United States Biological Survey, estimates that the cats of New York State destroy 8,500,000 birds annually. A. H. Pratt estimates that Illinois cats kill 2,508,530 birds annually. Massachusetts cats are credited with destroying about 2,000,000. Nove

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r ” > 1’s ve en Ba a2eonwrm aso — 7 _~ ery eS — November, 1920 A Crane with a Code Is Soon Started : i a I * } ‘ee fs . : ee %, bs Ss = “Boom down”’ and “Hoist load” signals are just the reverse of “Boom up,” “‘Lower load” signals. The right thumb goes down and the left palm is turned up , ‘Stop!”” What is the best way to signal it? Mr. Kelley spreads out his arms with both palms facing downward. The man operating the der- rick watches him closely After all, the code of the crane is really quite simple.. A left motion is indicated by a left gesture, and a right motion by a right gesture; to wit: the gesture below means “swing right” 67 bases ns “Swing left’’—indicated by a sweeping swing of the right arm to the left. George Kelley, a master mechanic, who helps build skyscrapers, is shown ex- ecuting a left swing Right thumb up, in this case, means ‘‘Boom up;”’ left hand outstretched with palm down means “Lower load.”’ Both of these orders can be com- bined or given separately Building means digging, and dig- ging means derricks. While the man on the derrick operates the bucket by control levers, he takes orders from a man on the ground, who signals with his hands

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Popular Science Monthly Five Thousand Pigeons in a Race > fo “Avy Nate’ or fe Cr Some of the five thousand carrier pigeons in the race making a mile-a- minute speed. These birds were sent off from places within a radius of five hundred miles of St. Louis ROM towns within a radius of five hundred miles of St. Louis, Missouri, five thousand homing pi- geons were released in one of the most remarkable races of its kind ever held in this country. At the speed of a mile a minute these feathered letter- carriers competed for prizes, the win- ners being the pigeons that first arrived home and registered in- side their loft compartment. The race was a feature of the convention of druggists held in St. Louis in September last. The lofts where the homers were trained for the race, are one hundred and eighty feet long and have two floors with eighteen compartments on each floor, each one being ten by fifteen feet. The lower floor is used only for breeders, while the upper loft is given up to the young birds in training. The roof of each upper compartment is painted a different color and the birds have been taught to identify themselves with the color of their own loft. 68 ~~ f", Photographs by courtesy of the Rexall Drug Co. The upper compartments of the pigeon-loft. The homer alights upon the platform in front of his compart- ment, and enters through a door that opens inward. His racing time is taken only when he arrives inside In training, the homers are conveyed varying distances from their loft and are released. They will fly straight home, settling upon the platform whose color they are trained to recognize Ponular Science Monthly Not

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November, 1920 November, 1920 Voting ‘by Machine . - One way to insure an. honest eléction - By Raymond Francis Yates every year? The taxpayers, of course. in a mechanical age. time. election system. ’ elections. How much do election frauds cost this country The figure has never been made known. ‘It would probably run well into the millions. Our election laws make fraud easy. case on record where the investigation and correction of fraud required an expenditure of eighty thousand - dollars and four years’. time. The ballot method of election ought to be extinct We Americans are prone to boast of our mechanical ingenuity and to forget that we have an election system that was old in Czsar’s The mere existence of the cash-register and adding-machine ought to make us ashamed of our The voting-machine insures honest There is one Who paid the cost? , | important, when he goes into the election booth to cast his vote, understanding, as he does, that he is discharging one of his most sacred duties as a citizen. Yet while an election officer is un- folding the ballots, he may “acci- dentally” tear a few. If he is clever, he may have a small piece of lead concealed under one of his finger-nails. He can do one. of:two things with this lead. He can-mark a ballot in a way that will render it void; or-he can place a cross next to the name of a man who was not voted for. He may decide to punch a hole through the ballot with his pencil-point, which would at once invalidate the vote. There are numer- ous other tricks to deprive an honest voter of his vote. Comparatively few people know that it is possible to sell their votes. How would the politicians know they had “delivered the goods,” you say? Most states provide a space for the voter to vote for persons not nominated. It is perfectly legal for the voter to vote for himself. If John Jones sells his vote to one of the parties, the ballot he used in voting can be identified by his name in the space allotted for it. This is simple enough and perfectly legal. The ballot laws actually encourage this practice. In the few states where no such provision is made on the ballots, other methods of identification are in use. Some states provide ballots must be that the HE ‘average American feels very’ folded in a certain way to be legal. When they are folded in this way, the marks show through the paper. The ballot can be rendered invalid by the slightest mark. A cross, a single line, no matter how short, added to the ballot nullifies it. Electior officers often take advantage of this fact in eliminating as many votes as possible belonging to the other party. At one time it was the practice on the East Side of New York to throw ballot-boxes into the river. Stuffing the ballot-box is a merry game. - Under the voting laws, each voter is entitled to-one vote only. What is going to prevent more than one ballot from being placed in the box under one voter’s number? The law? The law does not prevent ballots from mysteriously finding their way into the boxes. This fact is so After each election the machines are sealed and placed in a heavy case, where they remain until the next election 69 it tae Oe ee ee NeLEte: “eee eee $ a The voting-machine cannot be manipulated until the voter pulls the curtain about him, which releases the registering mechanism. i a secret ballot and eliminates rau generally known that laws have been made that state what disposition is to be made of votes cast in this illegal manner. If all of the voters were honest or if all of the election officers were honest and watchful, stuffing might be im- possible. One of the serious defects of the present voting system is the opportunity it offers for illegal prac- tices. While the opportunity for cheating exists, honest elections will be unpopular with those in charge. The ballot system is costly and grossly inefficient. In the larger cities the cost of an election runs well into hundreds of thousands of dollars. Each election district must be officered by men who receive from six to twelve dollars for their day’s work. After the election is over, the votes must be counted by. hand—a long, laborious task, pregnant with the danger of mistakes. As long as the counting of votes is done “by hand,” an unreliable method of election will exist that can- not: be more honest or trust- worthy than the persons con- ducting it. Many attempts have been made to perfect a machine or device that will make the me- chanical registration of votes possible. While there are cer- tain problems in connection with the perfection of a reliable machine, there is no reason why it could not have been done many years ago. The adding-machine had its birth in the fifteenth century. It paved the way for the voting- machine, but several centuries

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rolled by before the voting-machine actually came into being. During the last half century many attempts were made to bring voting to a mechanical basis, but few of these held any promise of success. A man in Balti- more invented a machine with which votes were registered by rolling small balls into channels provided for each voter. At the end of an election it was necessary only to count the balls. When the machine was tested, a few hoodlums put chewing-gum in it and wrecked the election. Another man proposed registering votes by having the voter punch holes in paper. This also passed out of existence. Rochester, New York, was one of the first cities in this country to try voting- machines. That was in 1878. The city is still using them. Not only this, but sixty-five per cent of the voting in New York state is done by this method. Thecompletereturns of a large city can be made known within one hour after the polls close. In the city of Niagara Falls, where. the. voting- machine has been in use a number of years, the returns of the election are made known and the ‘‘ex- tras’ printed and on the streets for sale within forty-five minutes. In Buffalo, a city of over half a million population, the election returns are made public one hour after the polls close. This voting - ma- chine is strictly a mechanical device. It operates with mathematical accu- racy. Before the voter can cast his ballot he must pull the curtain of the machine about him with a handle provided for the purpose. This in- sures a secret ballot; the act also unlocks the machine. When the curtain is opened, the machine is relocked and cannot be manipulated. After the voter pulls the curtain about him, he sees before him a board on which the names of the candidates of the various parties are arranged in rows. The Republican party occupies one row; the Democratic party an- other, etc. Over the name of each voter is a small lever. It is necessary only to throw this lever down to vote for a candidate. If the voter desires to vote a “straight ticket,” he has only to pull down all the levers in the party row. Levers are also provided to vote “Yes” or “No” on questions. When the voter has thrown the levers down over his candidates, he pulls the cur- tain back and steps out. While the curtain conceals the voter, he may make any changes he desires, since the vote is not registered until he pulls the curtain back and departs. It is possible only to cast one vote for -each office. . For instance, when one candidate for mayor is voted for, the lever over the other candidates for the mayoralty are automaticaHy locked and cannot be operated until the other lever is lifted in case a change is de- sired. — The Integrity .of the Voting-Machine But can’t some one open the back of the machine and change the registered number for any candidate? When the machine is in use, the back doors are locked, and they cannot be opened even with the keys provided for the purpose. On the other hand, when’ the back of the machine is opened to read the result, the levers on The back of the ma- chine open. The re- sults are registered here, and it is nec- essary only to copy them off when the polls close. The votes cast for each candi- date are registered on anindividual counter. When the back of the machine is open,’ the levers on the front are inoperative Shall the sale of Liquor he Licensed? ll 7. Pers nanny | vices TICKET a ae. Popular Science Monthly the front are inoperative. There is also ’ a counter on the machine that registers every time the back doors of the ma- chine are opened. A counter also reg- isters every time the curtains are pulled together, thereby keeping a record of the number of votes cast. When the election is over, aseal is placed on the locking device of the curtain, and the seal cannot be removed until the next election without detection. Plot and plan, scheme and engineer as he may, the crooked ward-heeler cannot discover a way of cheating the machine. After the election the machine is placed in a strong packing- case and sealed up until the following year. The machine is honest, and _ its honesty is fully protected from those who would destroy it. Voting mechanically greatly reduces election costs. The number of clerks -in each district and the number of election districts are reduced. This is made possible by the rapidity with which the voters are handled. Hence more voters can be crowded into a dis- trict. In the city of Buffalo, the number of election districts was reduced from one hundred and fifty to one hundred and eight after the introduction of the ‘voting-machine. This reduced the election costs fourteen thousand dol- lars a year, besides eliminating fraud. Expensive recounts and contests are avoided through the use of machines. In the case of a recount, it is necessary merely to remove the machines from their cases and re-copy the results. The dictum of the machine is abso- lutely final. This ayoids expensive. contests in the courts, where long and. costly litigation often results. Shall the town purchase a stone crssbert 9 CONSTABLE * Vata for any three _ In voting by machine it is necessary merely to throw the lever down over the name of the candidate one wishes to vote for. When the voter pulls back the curtains that screen the booth, his vote is registered 70 2 TH

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November, 1920 His Master’s Voice—Loud and Deep HE superintendent of a:large American electrical ' plant was called into a conference. While waiting for it to start, he gazed out.of.the window at the busy yards a short .distance away. ‘Suddenly he noticed a load of material coming down the track. The foreman was in another:part of the yard and could not-see it. The superintendent, up in the conference room, turned his head and in an ordinary speaking voice said, ‘“Open your switch; load coming.” Immediately the foreman down in the yards swung round and obeyed the order. How did he hear it? By means of the new loud- speaking telephone that amplifies the ordinary speaking voice so that it roars out of the other end of the wire. In the conference room there was one of the special “loud-speaking”’ transmitters. It was located about two feet away from the superintendent. When he turned toward it and spoke, the resulting sound-waves hit the diaphragm and thus caused the electrical waves to pass into the ampli- fying device. The amplifier is provided with several valves that increase both voltage and power. By the time the electrical waves leave it they are enormously increased. They travel across wires to a series of receivers, all of which are equipped with horns similar to those used on gramophones. The diaphragms of these receivers are crinkled and thus stop the reso- nance that would create confus- ing noises; the voice rings out clearly and distinctly. Any number of receivers can be used, and one small voice on the transmitting end will issue forth from them all. But the number of valves in the amplifier must be increased when more receivers are added. There are eight receivers in the yards of this particular electrical plant. They are so arranged that the voice on the sending end of the telephone can be heard dis- tinctly all over the company’s yards. Recently, in Christiania, Nor- way, one of these receiv- ing horns was erected out- side of a large news- paper office. One of the reporters at the transmitting end was calling off events in a great skating-match going on at the time. This was for the benefit of the passers-by. But the pass- ers-by were so interested that they stopped passing, and soon a great crowd had collected outside of the building. Traffic was held up and the city police were very much annoyed. What would they do if baseball became the Nor- wegian national sport? The superintendent in the office saw the trainload coming down the tracks and by .means of the loud-speaking telephone he warned the foreman The superintendent used his speaking voice; yet the yards foreman heard him distinctly Magnet Coils! to drive Armature’ ‘SECTION OF. LOUD SPEAKING RECEIVER } Diaphragm crinkled to stop resonence . TOP PORTION TH eg i = ous SPEAKING An amplifier greatly increases the volume of an ordinary speak- ing voice Hauling in 2000 Barrels of Fish ETACHED and dis- A model of a huge fish-trap that is capable of bringing in from 1000 to 2000 barrels of fish at one time 71 jointed, the sections of a gigantic fish-trap can be put together in half an hour. When complete, it measures 60 feet in diam- eter. The hoops which hold the net are 15 feet apart and 10 feet deep. Though the dimensions of the trap are large, it is easily manipulated, a crew of only. six men being sufficient to handle it. The trap is the inven- tion of Fred P. Smith, of Chelsea, Boston. A haul of from 1000 to 2000 barrels of .cod, pollack, herring, bluefish, mack- erel, or any surface fish, can be caught in the net.

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Popular Science Monthly Fifth Avenue Twenty Years After — + ae al. AR % expe eleceaigis ee ee Fifth Avenue has long been New York’s favo- rite parade ground. Twenty years ago, when women wore huge hats and tiny waistlines, they pa- raded up and down the avenue just as they do to-day The picture shown above was taken on Easter day in the year 1900. The one at the left was taken recently. There is just one auto-: mobile in the large pic- ture. Find it, if you can. The day of the traffic “cop” had not arrived Regulating an Electric Railroad’s Power HERE is a new automatic power limiting and indicating system for electric railroads. The system is based on the desire to prevent exces- sive peak loads which might cause serious voltage variations. It accurately records at one place and on one meter the total power supplied to the railroad’s trans- mission lines at a number of points. The illustration shows a train- despatcher’s office with an indicating instrument above the clock. The function performed by. this device ‘is that of automatically limiting the maximum power demand and re- cording the total net power. Regardless of the number of feed- ing-points, the dial indicates to the train-despatcher at all times the total That small dial over the clock registers the power in use ona complete railroad division 72 net amount of energy being delivered to his division, with permanent record for future study. The controlling device automatically deducts re- generated power if it is returned to the power company’s lines or trans- ferred from one line to another over the railway company’s transmission line. It will automatically limit the amount of power supplied to the division by lowering the trolley voltage and slowing down the trains so that the maximum peak load on the system cannot exceed a certain predetermined maximum. The maximum limit can be changed instantly by the despatcher without the necessity of notifying substation operators.

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November, 1920

What the X-Rays Reveal about Matter The atom‘has-a skeleton and'thé X¢rays show its structure HEN the X-rays were first discovered, scientists were not quite certain whether or not they were light. Light, as every one knows, is a wave motion of the ether. X-rays have waves ten. thousand times smaller than ordinary light waves. The ordinary prism or diffraction grating could not resolve an X-ray into a spectrum. <A spectrum is due to interference of the light waves. There could be no interference with a diffraction grating because the lines could not be ruled closely enough. In 1912 it occurred to the German physicist, von Laue, that perhaps the atoms _ in a crystal might act. as a diffraction grat- . ing. They were certainly closer together than lines could ever be ruled on a plate. He made the experiment. He obtained an X-ray spectrum. It was established that X-rays are light rays. Now the X-rays are produced by the bombardment of a substance, usually a metal, with what are called electrons. Every atom is composed of a nucleus and-one or more electrons revolving around it. An atom, therefore, is a kind of solar system. Shoot electrons at a substance in a vacuum and X-rays are given off by that substance. A trons. Down Came Eight Hundred and Fifty

2% * i . me Oe A shortage of buildings and of brick existed in Hilton, Cali- fornia. It was decided to raze an old chimney which contained eight hundred and fifty tons of brick—enough to relieve the brick shortage. A big notch was cut into the chimney’s base. As the -bricks were removed, supporting timbers were put in

A model of an atom. The balls-show the positions of elec- These positions are not guessed at; they are deter- mined by X-raying different crystals in powdered form. In front of the model is the X-ray apparatus young Englishman named Moseley produced X-rays from every metal— from aluminum to gold. He made photographs of the X-ray spectrum of each metal. He proved conclusively that atoms are indeed built up of electrons, and that when, for example, the chemist said that aluminum con- sists of a nucleus around which thirteen electrons are grouped, it was true. Moseley showed that what is known in chemistry as the periodic table—a table in which all the elements are Slowly at first, then with increased speed, the big pile of brick moved earthward. There was a great crash

arranged according to their atomic weights—is curiously related to the electron theory. Hydro- gen is the first in the table. It has also the lightest atom. At the extreme end is uranium, which has the heaviest atom. : The numerical position of an element in the table is significant. Thus alu- minum is thirteenth in the table. Moseley also proved that. an aluminum atom consists of anucleus around which revolve exactly thirteen electrons. Simi- larly, uranium, which is the ninety-second in the table, has ninety-two elec- trons revolving around its nucleus. Continuing .. Moseley’s work, the two Braggs, father and son, proceeded to determine the exact positions of the electrons in an atom by means of X-ray spectra. Their work, with an improved apparatus of his own invention, has been continued in this country by Dr. A. W. Hull, of the General Electric Company. Thanks to the electron theory, physicists now know why oxygen combines with iron and not with some other metals; why some substances are conductors of electricity and others not, and why helium is inert, that is, does not combine with other elements. Tons of Brick

: — , . \ a . 7 _ “da ~~ iy * . ere ID s, *. ee f 4 Ba. far.’ When the timbers were all in place, they were covered with gasoline and set on fire. The men then gathered up their tools and drew away to watch the big crash from a safe distance. As the fire burned, the timbers be- came weakened; they groaned under the terrific weight, and— down she came!

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Popular Science Monthly A French Machine that Bottles and Labels FROM France there comes a new quick- action wine-bottling machine. French- men have plenty of use for it. They drink a bottle of wine with nearly every meal! The machine interests us only theoretically. The wine is poured into a tank which looks like our orangeade tanks. It is shown at the left of the picture above. A pipe connects the tank with a vat be- neath it, and a faucet controls the flow of the wine, and the wine in the vat re- mains at a constant level. Eight siphons carry the wine from the vat to bottles which are placed on holders below. Special valves in the siphons regulate the amount of wine that goes into each bottle. When the bottles have been filled, they are corked and labeled. The label- ing is done automatically by a machine shown at the right. Parallel rollers revolve and release the labels. Cracking Nuts with a Stick we you like to know a new way to crack nuts? This is not a joke, but a serious question. If you are out in the woods gathering nuts some day, and have no nutcracker with you, make one. You take a stick and cut a notch in it. The notch should be about two thirds as deep as the average nut, and a little wider. You insert a nut in the notch, press on the top of the stick, and The Table that Collapses A NEW folding table has been invented by Vernon M. Gay, of Danbury, Connecticut. Opened up, it has an attractive circular top whose leaves barely give a hint that they are not built to be permanently spread. Presto! The sliding clamp along the main support is moved, and down come certain sections of the leaves, making the table-top a perfect Maltese cross. Then a slight manipulation of the clamps, and the whole top folds down in the form of a square box. The table then ‘ can be used as a pedestal; or it can stand inconspicuously in the corner of the room. Worms that Spin Silk in Every Color 6 ew silkworm has no taste for color, for which reason its silk is drab and must be dyed before it is woven. By feeding the worm certain leaves it can. be made to spin its silk in various beautiful colors. Dr. Vartan K. Osigian, an Ar- menian, has developed this process, and the silkworms spin silk in eighteen different shades. Neither the sun’s rays nor boiling will cause the silk to fade. There are two hundred thousand worms on Dr. Osigian’s farm at New Orleans, and they will turn out a cocoon apiece in seventy-two hours. These cocoons consist of two strands of silk, each containing eighteen hundred yards. The ordinary silkworm does not turn out anything like that amount. Above you see Dr. Osigian feeding his worms with the mysterious leaves that have this effect. He comes from a long line of “silk kings.” Mittens for the Athlete’s Feet ON each hand there are four fingers and a thumb; and on each foot there are five toes. We Americans do not usually put our big toes in a class by themselves, as we do our thumbs. Thus the toe of our stocking is all in one, and so is the toe of our shoe. But in Japan, ideas are different. The big toe is considered a thing apart and in consequence it is often isolated. To the left you see the legs of a your nut will crack. The meat will be intact and so will your fingers. Soft-shell nuts can be opened in this manner, provided the material composing the stick nut- cracker is of, the right degree of toughness. It is something new, any- way. If it does not work, try the nut with a rock, ' though it will not be as safe for the fingers as this stick suggestion has been found to be. Japanese athlete. On his feet he wears a pair of running-shoes which are made so that his big toes run by themselves. Per- haps this shoe construc- tion enables him to grip the ground more firmly. In spite of their short legs, ‘the Japanese are fast runners and good all-around athletes. ‘The average American’s legs are more than half the length of his body. The reverse is true of the Japanese,

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November, 1920 Weighing the “ Lift”’ of a Balloon FREE balloons of small size are used by the United States Weather Bureau to help in determining the conditions of the atmosphere and to aid the forecasts which are so valuable to aviation. The drift of free balloons and the motion of the clouds are the weather-vanes of the upper levels. _ It is important to test the balloons and to determine their lifting power. This is done by an expert making use of delicately balanced scales to which the balloon is attached. The counterweight necessary to balance the lifting power of the gas with which the balloon is inflated, furnishes the required information. Balloons of larger size equipped with recording instruments are used to make soundings of the upper atmosphere. ‘Hair-Dressing Styles for Cattle [_ONG-HAIRED breeds of cattle, such as Hereford, Galloway, or Angus, are carefully ‘“‘frizzed up’’ before they are taken into the show ring of the exhibition. Sponge baths and daily scrubbings with soap and water, and much brushing, get the hair in condition for final treatment. Just before Bossie goes into the tan- bark arena, the attendant moistens her coat with a mixture of olive oil and de- natured alcohol which makes the hair lustrous and fluffy. He then brushes and parts the hair, care- fully using a round curry-comb for curling it, and producing ays the attractive finish calculated to find favor with the judges. A Pile-Driver that Does Not Drive F machines like this one are used, the “bump, bump, bump”’ of the pile-driver will no longer be necessary. This driver screws steel piles into the earth. It works silently but efficiently, putting a steel pile in place as quickly as the ordinary pile-driver. The end of the pile is provided with crude cutters and a single screw-thread. The cutters bite into the earth and the screw- thread causes the pile to follow them. The pile is bolted to the driving-rod of the machine, which is turned by an electric motor connected to it through a train of gears. Roll Your Umbrella by Tube | Dabo try to roll an umbrella smoothly so it will not bag in the center? The man who knows takes from his pocket a small aluminum cylinder lined with leather and having upon it a gold monogram. Into the end of the cylinder he places the point of the umbrella, holding the cylinder in his left hand. Rolling the cloth in com- pact folds is now a simple matter. The difficulty of hand-rolling is to keep the folds under even pressure and not to let them become loose before the top of the cover is reached. By making use of the “roller,” the cloth is held rigid enough to assure even rolling. 75 Farmers Become Experts at Grading Grain ” HAT is the quality of your lot of grain?” is a question that must be answered. The mass must be probed and. a sample taken out to be graded. It is neces- sary to obtain equal portions of this sample. The Department of Agriculture has put forth an invention which any one can make. It consists of a metal cylinder, at the top of which is a container for the grain, poured in by a funnel. The bottom of this container is closed by a cap manipu- lated by a lever. Pull the lever and the grain flows over the sides of a cone. Part of it pours into chutes which convey it into the pan at the bottom. An equal portion flows be- tween the chutes and drops into a pan. In this manner the sample of grain is exactly divided, and the test can be made. No Bugs in the Movies HOUSANDS of dollars’ worth of damage has been done by moths spot- ting the films during the making of moving- pictures at night. A special trap has been invented by F. S. Mills and Clyde Ewing of the Hollywood Lasky Film Studio. The device consists of a wide box open- ing, a carbon arc, two 100-candlepower lamps, a funnel made of an or- dinary milk-can, a suc- tion fan, and a large net receptacle in which the moths are trapped. In ten minutes nearly ten pounds were caught.

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Carrying Heat in the Coat Pocket ITH one of these little hand-warmers in your pocket, you need not fear the biting winter cold which threatens to benumb your fingers. Take the hand-warmer, a cylindrical box of nickel, out of your pocket, re- move the cover, strike a match, and light the wick soaked with the benzine with which the box is filled. Then replace the cover and the trick is done. The interior of the eover is lined with a coating of a metallic sub- stance which glows and gives out considerable heat when it is exposed to the vapor of benzine. The metallic lining of the cover will continue to glow and to give heat for about eight hours, or until there is no more benzine vapor. Primitive Styles in Automobiles is the early days of the automobile, each new type was larger and more compli- cated than its predecessor. Electric-light- ing systems, new kinds of steering devices, ammeters, oil-gages—one by one, they were added. And now, after twenty years of auto- mobiling, we find the small, simple car in , vogue again. Below you see a “new” Dutch automobile. It has a one-cylinder engine in front, three wheels, and a steering apparatus very much like the original ones. Instead of turning a wheel, the driver moves a lever from side to side. This was done twenty years ago. She’s Practically Unsinkable T= Brude is the latest approach to an unsinkable lifeboat which combines the capacity advantage of a raft. Forty-four people, twenty on the deck and twenty-four on the continuous seat run- ning around its sides, can be accommodated. In a compartment beneath the deck water ballast is carried, while buoyancy tanks are arranged around the boat under the continuous seat. On the upper deck, or roof, thirty extra people can be carried, making the capacity of this lifeboat equal to that of a raft. As the picture shows, the Brudz is ellipsoid in shape and is built to carry a sail to sup- plement or take the place of oars. In the near distance is seen a com- plete view of this craft sailing. 76 Popular Science Monthly Washing-Block for the One-Armed Have you ever won- dered how you would manage if you had only one arm? The accompanying pic- ture shows a German in- vention. It is a washing- block for the one-armed. It may be fastened to the wall of the washroom or clamped to any conve- nient piece of furniture when traveling. A band of loofah covers a semicircular curve in a block. Beside the block there is a small scrubbing-brush fastened. The loofah is dampened and_ rubbed with soap. The arm and the hand are rubbed against the loofah and the brush, and can then be rinsed off under the faucet or in a bowl of water. Then the loofah band is removed and a strip of toweling is put in its place. No Stakes or Nails Needed Here a place is home-sweet-home to this fence. There has always been a great need for a fence of this nature and at last an enterprising inventor of -Palo Alto, California, set about the task of develop- ing one. The result of his labors is shown.- In erecting this fence it is not necessary to drive stakes or nails. The units hook to- gether and they are prevented from falling by cross-pieces mounted at right angles to their length. The units are light and can be readily transported from place to place. A single truckload is sufficient to make a large enclosure. The fence is just as ser- viceable as a permanent one. Each unit is sixteen feet long. 7] es ri it i conan eg nwt DPaomiular NSevence Monthly no

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November, 1920 oF © Underwood & Underwood ; Is This a Street-Car or Is It a Cage? ERE is a street-car that looks some- thing like the monkey-cage at the zoo. In fact, this car would make a very suitable vehicle in which to transport monkeys. Few changes in its construction would be necessary. This car is one of many equipped in the same way for protective purposes. During the recent strike of the men on some of New York’s great subway and surface-car railway systems, it was decided to place this protecting screen on every car to pre- vent injury to the passengers should the strikers get rough. Before the strike was over, the screens proved very useful and saved many a broken head. As a further precaution, two policemen were placed on each car, one atthe entrance and one at the exit. Although these pre- cautions minimized the danger of accident, they did not prevent it altogether. To Warn of Unseen Danger HERE is a new danger-signal that warns you whether a monkey-wrench may fall upon you from above, or a man- hole cover blow up and hit you from below. The signal is provided It Pays to Advertise 7 SCENT which. pays the best, an’ then, go into it bald-headed:” Sosaith the poet, James Russell Lowell. The same sentiment was held by the bald-headed man above; he scented adver- tising. Whereupon the words, “Venez ce soir au Café du Nord’ (Come this evening to the Café du Nord), were painted on his bald head and he sat every evening on a boulevard in Paris near the café. The pro- prietor paid him well for his advertising space, which is one time that a bald- headed man had the advantage over his shaggier brother. Water, Only Five Cents a Glass — who let the water drip for days be- + cause you are too lazy, or busy, to repair a broken washer, take note. In Constantinople folks must pay five ‘cents for a glass of water! Above you see an army officer getting his nickel’s worth. The water supply in Constantinople, however, is gradually being increased. The use of cisterns has been almost entirely abandoned. Instead, water is piped from reservoirs in the forest of Belgrade to vaulted chambers in the city from which it is. distributed to fountains all over the city. Water-carriers supply the various houses. It is peculiar to note that nature does not always place water where it is most needed. In more torrid regions of the world water is not as plentiful as in the United States. It causes one to wonder what happens at a fire. A Most Extraordinary Clock pas and simple as this clock looks, it is really very complicated. Not only does it tell the time of its own home town, Aurora, Illinois, but upon request will tell the time of places all over the world. with an arm that points either up or down toward the source of possible dan- ger. It was invented by Ken- neth P. Babcock, who is a safety engineer of Spring- field, Massachusetts. He calls attention to the fact that it is the unseen source of danger that is the dead- liest—in other words, the one above or below the range of vision. The indicator is turned to register either “Above” or “Below.” The indicator circle is white and all the remainder —lettering, indicator, and pipe —is painted black. - entire signal is five feet tall. It also gives astronomical and atmospherical read- ings, and has thermometer and micrometer attach- ments. It is wound every two months by two fifty- pound weights. The clock was made by a man named Blanford; he spent most of his life working on it. When he died, Aurora bought the clock, and installed it in a conspicuous place. The workmanship in the clock is of the best, and the future citizens of Aurora for many years hence can expect to find it running, and by it they can order their lives from day to day as their ancestors did before them. Nanomhor 100N

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Popular Science Monthly

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Thié. Toul -Ghihes ‘Scale from: Boller Tubes [F boiler tubes are made to vibrate at a high frequency, they will shed their scale as a duck’s back sheds water. This little tool climbs into a boiler tube, carrying its flexible feed-pipe after it. It obtains its power from steam or compressed air. When the steam or air is admitted to the tool, its “vibrator head” gets busy and vibrates rapidly. This vibration is im- parted to the boiler tube and the scale is shaken off. The accumulated matter on the inside and the outside of the tube is forced to leave. The vibration of the tool is very mild though effective. It can be held in the hand with perfect comfort while it is vibrating at high speed. This makes it possible to use the tool with no fear of its harming the tubes of the boiler in any way. This is one of the most effective methods oi removing scale cheaply and without danger to the tubes. Through Wood with X-Rays f eapeddeaene rays penetrate wood with the greatest ease, and it is possible to detect imperfections so small that they ordinarily would escape notice. Samples of wood from which airplane spars are to be made are planed perfectly smooth, and the grain is seen to be straight and even. But if there should be an internal knot, shake, or crack, it would appear distinctly in the radiograph. Airplane parts must be absolutely sound. The eye cannot penetrate into the wood, for which reason it cannot be com- pletely relied upon. Hence the X-rays must take its place. Paper-Lined Cars Are Frostproof He’ can potatoes be shipped by railroad in cold weather without their freezing? Agriculture’s Bureau of Markets considered the subject and came to the conclusion that paper would do the job as well as Experts in the Department of anything. Paper is a good insulator. Both ex- treme cold and intense heat fail to affect it greatly. That’s why, in winter, people wear paper in their shoes, and wrap them- selves in paper vests. But a paper vest for each potato would not be practicable. What to do then? Why not line with paper the cars that carry the potatoes? Place a thick layer of paper on the floor and fasten planks over it. Do the same to the ceiling and the sides of the car. The car will then be well protected from outside drafts of cold air, and the potatoes placed within will reach their destination untouched by the frost.

A One-Handled Knife and Fork KNIFE and fork that folds up like a jackknife has been in- vented by Rudolf Strop- pel of West Branch, Iowa. The inventor tells us that it is intended for people with one hand and “‘campers, or others in like situation.” By this, we judge, he means travelers of all kinds who may desire a quick meal on the road. When the knife and the fork are opened up, they are sufficiently far apart not to interfere with each other. To close them up, you press a button in the handle. But when the fork is laden with food and is on its way to your mouth, take care that you do

Make the Shovel Into a Hoe HY not combine the hoe and shovel into one tool? The hoe digs down and the shovel digs up; thus one blade will serve both purposes if its direction can be adjusted and its shape can be modified to suit both operations. Mr. Joseph Szabo of Newcastle, Pennsylva- nia, has invented just such a tool. The blade is flat and yet rounded at the end. It swings at the end of the handle and can be fastened into either the hoe or shovel position by means of a small wrench, which is shown beside the shovel in the picture above. The tool can be used for heavy farm work and

not press the button. for light. garden work.

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November, 1920

A Pattern that’s Already Laid AS the high cost of clothing is due largely to the high cost of labor, any labor- saving machine is welcome. Above you see an electric vattern-marking machine that does the work of many skilled men. When a certain pattern is decided upon and laid out so that the least possible amount of goods will be used, the new marking-machine traces this pattern on a sheet of chemically prepared paper. As the machine passes over the paper, it makes perforations in it at the rate of from three hundred to three thousand a minute, depending upon the speed at which the machine is operated. There are seven speeds to choose from. The paper chart thus made is placed over the cloth to be cut and white powder is dropped on it. It goes through the per- forations and leaves a white trail on the cloth below. How Yow Pon Tell if Cement <3 Is Waterproof oo cement is waterproof, and some is not. But you can’t tell by looking at them which is which. wren rite’ If you wish to find out, sprinkle some of the cement on top of a glass of water and then thrust your finger into the water. If the cement contains the proper amount of waterproofing material, your finger will be dry when you pull it out of the water. A New Use for Talc ARIUM $s sulphate, like many other things, is very scarce. It has always been used as a filler in paint and now a substitute must be found. Many paint manufacturers have decided to try using a tale which belongs remotely to the same family as the talcum powder you use. For years tale has been considered greatly inferior to barium sulphate, but now that actual tests of it are being made, its reputation has begun to improve. Although tales from different localities vary both in physical appearance and chemical content, their differences become unimportant when they are ground very fine.

Lifting Men with Kites b | vse deat you have an irresistible desire to go up in the air, try kiting; that is, ascending by the aid of man- bearing kites. You will be sure to find it a decidedly exciting and exhilarating sport. Kiting of that kind is a favorite pastime in France and there are numerous clubs devoted to this sport, which have formed a general organization, known as Union Cerfvoliste de France, the headquarters of which are at Issy les Moulineaux, on the outskirts of Paris. Large kites, stoutly built, and of care- fully tested material, are sent up. in tandems of two or more, held by a wire or light cable. Two kites that have an aggregate sur- face area of about 140 square feet will support the weight of a person of about 140 pounds, provided the wind has a velocity of at least 28 or 80 feet a second.

The Box that Won’t Come Off REIG’S “Morning Mood.” That’s the name you see on the box. You take out the music-roll, adjust it in place in the player-piano, and start working the pedals. But the first bar or two tells you that “you’ve come to the-end of a perfect day.” Of course it’s a mistake. Somebody put the music-rolls back into the wrong boxes. That’s why you got the end of the day instead of the beginning. How can this be avoided? By never taking the rolls out of the boxes. If the boxes are made smaller and the ends of the rolls are allowed to project out of them, these ends can be engaged with the spindles of the piano, as usual. Of course the boxes must not. interfere with the rotation of the rolls. A Tooth-Brush that Twirls as It Cleanses it you brush your teeth regularly three times a day and do it thoroughly, you need not fear the dentist’s chair. But what kind of brush is best for teeth? Owing to their peculiar irregular formation, it is difficult to construct a brush that will reach all the hidden corners and crevices. Some dentists advocate large brushes; others favor small. Some think they should be curved; others say they should be straight. And now we have a rotary tooth- brush. It was invented by Mr. Jacob Goldstein, of West Hazleton, Penn- sylvania, who has long rebelled against them all. This new tooth- brush consists of two small circular brushes that are made to rotate by means of a handle located at the end of the implement. The brushes are paralle! and the space between them is sufficiently large to admit a row of teeth. When you turn the handle, the brushes rub against the teeth and are able to touch the seemingly inaccessible spots. Of course when the brushes rotate, the tooth-paste and water on them tend to fly outward—as in the case of snow on a snow-plow. But to avoid this, each brush is equipped with a sort of mud-guard. Thus the pasty water is retarded in its flight, and can be removed when the cleaning is over.

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Do It with Tools and Machines A one-man high-speed ball- bearing jack. He shifts the lifting lever into sockets provided for the purpose, tips it over on its own permanently attached wheels, rolling it where needed The removal of fuses from high-voltage cir- cuits is risky work. If a porcelain handle is attached to a large fuse, it can be removed without danger to the workman This jig automatically clamps and ejects work, requiring hand-feeding only. It is operated by the foot. A short ac- tion clamps down the part to be drilled be By attaching a carpenter’s brace to this apparatus you can easily drill holes in steel. The chains keep the drill tight against the steel that is being worked This machine is a whole factory in itself. It performs five different tooling operations on the same piece. One man only is required to operate the machine and his task consists in feeding the rough work and removing the finished article An electric heater designed for heating shoe-manufacturing tools, the heater keeping them hot until needed This machine removes by vibra- tion any cement left in the bags. The bags are also baled and counted before removal from the machine. Both time and money: are- saved by its use The air-driven blower is something new ona forge. All the black- smith has to do is to regulate the flow of air instead of pumping the bellows In building operations in which reenforced concrete is used, it is necessary to cut the reenforcing rods of iron. This cutter will cut such rods any length The conc ’s punch clips a hole in commuter’s ticket, and the piece falls into the con- tainer. Puncning the ticket registers the fare Popular Science Monthly

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Candles are popular because of their beauty, but the light they give is insignificant. If the can- dles are placed in front of a mir- ror, as is the case in the fixture above, the candlelight should be doubled because of the reflection Housekeeping Made Easy Here are various devices to save energy and obtain better results You can preserve the polish on floors with this device. You wrap a cloth around the circular brush and mop up the dust. Then you use the brush for polishing. You lock it in a certain position until the exposed bristles become dull; then you change it She’s crushing grapes. The machine is a porce- lain-lined box and a wooden wedge that is forced down by a handle. The grapes are crushed between the wedge and the container 2a When.it comes to rubbers, we are as bad as the naughty kittens who lost their mittens. “A strip of rub- berized material attached to the in- side of each rubber will keep them fastened together; it fits inside the rubbers when not in use A usual rigid washboard wears out the clothes rap- idly. But a washboard made up of small wooden rollers is much more merciful to them Curling-irons and hot-water bottles usually haven’t much in common. But an iron whose handle is detachable will heat the water in a bottle by inserting the rod in the bottle and turning on the switch When you dig into a grapefruit, you’re almost sure that some juice will find your eye. Put acover over the fruit, and you'll be safe Ags Feeding clothes to the wringer by an endless belt- conveyor will save your hands and insure smooth feeding It is essential to have an airtight cover on a jar of preserves. Two new cover wrenches are shown above. The one which grasps the jar has an adjustable tape band attached to a metal handle. The wrench that grasps the cover is all metal Here is a safety seam- ripper. An ordinary razor-bJjade fits in a tooth- edged cover to which a handle is attached. As the blade cuts, the teeth guard the cloth and pull out the threads een waa |

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One man can mount and dismount a large motor-truck wheel with the aid of this newcrane, accomplishing the job with speed To Mount Heavy Truck Wheels HE problem of mounting and dismounting heavy motor-truck wheels has become more and more serious to the motor-truck owner as the size of his fleet increased, making the operation more often necessary for re-tiring the wheels or greasing the bearings. But the problem has. been solved by the development of a special wheel- lifting crane by means of which one man can remove or mount the heaviest truck wheel. The crane is adjustable for any size of wheel or tire and special grab-hooks are furnished for removing wheels fitted with giant pneumatic tires instead of solids. When the truck has been jacked up, and the hub-cap, axle-nut, and bear- ings removed, one man rolls the crane to the wheel. The grab-hooks, reaching under the fender, grip the steel rim on either side. A turn of the hand- crank, and the crane lifts the wheel so that it hangs free and straight. The crane and the suspended wheel are then rolled back from the truck, and the wheel is off in no time. ‘When the wheel is ready for re- mounting, the crane and wheel are rolled over to the axle. The wheel is slipped into place with one motion, the grab-hooks released by a turn of the crank, and the job is done. All that the operator has to do is to set the grab- hooks, turn the crank, and roll the crane on its casters. The grab-hooks are set to the proper width by an adjustable splice-bar. They take hold as do a pair of ice-tongs—the heavier the wheel, the tighter the grip. A simple adjustable stop- bar at the base holds the | wheel in a vertical position so that it may be slid over the axle spindle, even when a sprocket or brake drum would otherwise tend to slant to one side. vineyards, This hose automatically pulls up out of the way when not in use Popular Science Monthly Protect Your Garage Air Hose ECAUSE all motorists are human, and therefor? often negligent about coiling up an air hose so that it will not be run over by other motor vehicles, walked upon, and eventually made to leak, the Standard Oil Company of California has developed an underground counterweight system of hose protection at one of its service stations in San Diego, California. The underground counterweights operate a_ steel cable over a pul- ley, the outside end of which is attached to the air hose. The weight of the hose is slightly over- balanced by that of the counter- weight, so that when some one has finished in- flating a tire, the hose is immediate- ly drawn up out of the way. The hose is thus kept out of has a chance to walk on it, run over it with an automobile, etc. The moral of the story being that the hose has a much longer life. From Vineyard to Bottling-Plant ERE is a truck that is not used in the country of prohibition, but that marks a new step in highway transportation in France, where it has displaced the hand-cart, the ox- team, and the small wagon for col- lecting wine from the vineyards and carrying it to the bottling-plants. In the old days, each grower carried his own wine to the bottling-plant. This ees q es Yo So Ss 2 . “= & 2 . a “Sy >» ne x > * 4 ’ % : ' £ ‘ Ae ee i] A | pe TELESCOPING [a gig cOLLEcIN PIPE A et SS 4 Instead of water, this truck collects wine from the It couldn’t be used in this capacity in America, but France still presses the grape 82 was slow and tedious work and like- wise expensive. It also took the grape- grower away from his vineyard, which meant a decreased production. Now with the motor-truck tank the grape-grower can produce more be- cause he does not have to leave his vines. It is cheaper to collect the wine by truck because of the greater volume handled at one time. The tank on the truck holds 1600 gallons, in addition to which 800 gallons can be carried in a tank on a= small _ two- wheeled trailer. The apparatus is ingeni- ously worked out. The wine is pumped into the glass-lined tanks by means of a special pump mounted on the truck frame di- rectly back of the driver’s seat and driven by power from the truck engine. There are four suction pipes, two on each side of the truck. When these are not in use, they are raised from the ground by means of telescoping pipes. When in use, they are simply dropped into the barrels of wine on the ground. danger. No one. an) 6 A ae PR A me tet te* at— 859 Sl

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November, 1920 An Automobile Radiator Shreds the Air NEW principle in the construction of automobile radiators shows the air passing through the radiator core shredded or broken up into a multiplicity of small currents. The purpose of this division of the air-stream passing through the radia- tor is to bring the greatest possible volume of air into contact with some portion of the core and thereby absorb a greater amount of heat from the water to be cooled. In the ordinary honeycomb type of radiator, the air passing through each cell touches the core around the circumference, but allows. the air in the middle of the stream to pass through without taking its share of heat from the water. Air passing through the radiator is broken up into small currents which carry off much heat Gaston Chevrolet, smiling and hopeful before the five-hundred-mile race © Goodyear News Service After six hours at the racer’s wheel, when fatigue left him almost helpless What Fatigue Poisoning Does to Us "HEN Gaston Chevrolet swept across the finish-line, winner of the five-hundred-mile International Sweepstakes automobile race at In- dianapolis last May, the spectators cheered wildly and marveled at the endurance of the plucky little driver who had sat at the wheel for six solid hours. They did not see him climb feebly from his seat and, supported on either side, walk with head drooped, eyes “dead,” and faltering step, to his garage, his face haggard from the fatigue of the long grind. They did not see attendants vigorously rub- knotted muscles, cramped from the strain of gripping the tugging, jerking wheel for six hours. That agonized expression which in- termittently swept across his visage, the lifeless stare, made him look like Getting Their Goats with a T is not every day that a motor- truck can act the role of a goat- getter, although this is exactly what the truck shown in the accompanying illustration does. Just how this came about dates way back to the early days of the eighteenth century when the old Spanish Mission padres searched the Pacific coast for converts. When they sailed away from Guadaloupe island, about three hundred miles from San Diego, California, some of the more adventur- ous goats that strayed from the fold were left behind. Between that time and now, they have multiplied bv thousands so that ‘today they are being broughi into San Diego on cattle-boats in lots of a thousand or more Once the boat is docked, the truck assumes its role of goat-getter. The goats are unloaded from the ship in groups of three or four by asteam windlass. The ropes are fastened around the horns of the When all is ready, the signal is given and up go some- body’s goats to be lowered into the truck awaiting them 83 a man who had just taken poison. And that is exactly what had hap- pened. Extreme physical fatigue is equiva- lent to poison, and, furthermore, fatigue poison is just as effective in its action as arsenic or carbolic acid. “The extreme exhaustion suffered by Chevrolet caused certain chemical changes to create poisonous decomposi- tion in the muscles of his body; in other words, the production and ac- cumulation of waste substances such as carbon-dioxide and lactic acid,” de- clares Dr. Clyde Leeper, of Akron, Ohio. “These in large quantities become known as fatigue poisons. They are carried throughout the entire body so that the exertion of one set of muscles leads to complete exhaustion of the entire body.” Truck animals, which are loaded directly into the truck body and then trucked off to the slaughter-house or the nearest rail- road shipping point. Eventually Mr. Goat is converted into fertilizer, sheep- skin, chamois, glue, and buttons. The use of trucks as goat-getters is but another of the unusual tasks to which motorized equipment can be put to good advantage. Before the trucks were used to carry the goats from the boats to the slaughter-houses and railroad sidings, the animals were driven through the streets. This was a slow and expensive process. It re- quired a large number of men to watch each herd so as to prevent any of the goats becoming detached from the main group and wandering off and becoming lost. The goats are moved quickly by truck.

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S-SCREW-OPERATED JAW : Above is a tire tool recently put on the market which quickly changes tires on ali sizes and types of demountable rims either of the solid or split rim design. A glance from left to right across these two pages will illustrate how the machine is made to do various kinds of tire work economically and quickly Place this stand beside the gasoline filling station, and it is only a minute’s work to deliver a quart of oil to the car needing it. This mechanical oiler keeps the oil clean and free from grit, which cannot be said of the open measure Popular Science Monthly Doing Things Mechanically The less handwork in the garage = == _ ROLLER ON a OUTSIDE OF RIM RIM- EDGE If the tire is stubborn after the lock- Mounting plain clincher tires on solid rings are removed, rotate the horizor- rims is made easy by using the tal arm that carries the gooseneck horizontal arm with the rollers bi?) Ve This tool handles all kinds of press- ing work, such as forcing off wheel- hubs or bearings, straightening shafts, etc. ONE PIECE BEARING ADJUSTABLE BOLSTER BALL BEARING HAND WHEEL A_ twenty - ton- capacity press. It is made from one solid piece of five-inch chan- nel iron, with no bolted corners or connections. The press is portable, and a feature is its ability to re- lease its pressure quickly RADIUS ROD SUPPORTS One man can handle unwieldy rear-axle assemblies with this tool. It consists of an axle-stand with two adjustable yokes for the live axle-shafts, and a bar support for the front end -of the propeller-shaft 84

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November, 1920 in the Automobile Garage the more money in your purse 4o LOCKING RING END-UNITING JAW Release lock-rings with the new tool by lowering the pivoted arm so that the roller pushes down the exposed portion of the adapter-ring, freeing it from the lock-ring TRUING UP RIM q The wheel to be repaired is held at a con- venient height and supported by a cone- bearing contact with the machined surface of the interior of the hub If a split ring has been sprung, it is hard to force the latching mechan- ism into position. Place one of the jaws.-against the latch and the sprung end is readjusted When necessary to replace a con- siderable number of spokes, proper alining or truing of the rim is essential. An adjustable indicator is provided to reveal the slightest variation CRANK SHAFTS \ Instead of the grimy funnel and the open quart measure, one may use a mechanical gravity flow. A thumb button controlls the oil discharged Truing up and re- pairing wire wheels is another task that is often most diffi- cult. But with this special stand the work is made easy. Spare spokes and other tools neces- sary for this kind of work are held ina cabinet below the stand, within easy reach of the work- man. Some addi- tional jobs that can be simplified by the use of this stand are shown below at the left Here the press is shown alining a crankshaft. The pressure is se- cured by the use of two large cam- faced washers or thrust-bearings. As the pressure on the screw. is developed by revolving the wheel to the right, these washers tend to PRESS LEVER \ climb, one against the other. The angle of the cam- faces, however, is such that they will not back off

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How the United States is carrying a railroad system to the north. Swinging a passenger-coach aboard a steamer bound for Alaska Carrying a Railroad to Alaska LASKA has been greatly in need of railroads. It was unable to build its own roads, owing to lack of car-shops, etc. facilities in the shape of steel-mills, But now the railroad system of Alaska is being gradually built up. The rolling stock and other materials are manufactured in the United States and sent north by water. Each vessel is capable of carrying four coaches on its deck, and before many months our northernmost state will have a railroad system of which it can be proud. The gold-diggers can travel in luxury as the great railroads nose their way into the wilds, displacing pack- mules and dogs. His Oxygen Tank Useless at 27,000 Feet Altitude ROGIN, a Swiss military aviator, decided to try to break the world’s altitude record. He rose higher and higher, until finally his airplane was no longer visible to the people watching him from below. When he had reached a height of twenty-seven thousand feet, and had been forced to use his oxygen tank, one of the connections suddenly broke. Progin immediately lost conscious- ness, and his airplane plunged earth- ward at a terrific speed. But when it reached four thousand feet, the aviator came to life, and regained control of his machine just in time to make a landing! How One Man Lifts a Ton One man does the work of five in moving aheavy weight with this spur- geared chain- block NE man with a pull of only eighty pounds can lift this one- ton block two feet from the ground in half a minute. One man can do the work of five in moving heavy weights, and he need not be a “strong man.” He pulls upon a chain attached to a new “‘spur-geared”’ chain-block, and lifts the INTERNAL GEAR LOAD SHEAVE INTERMEDIATEAR GEARS PiniOn ON PINION CAGE Showing the planetary-gear arrangement of the Yale spur-geared chain-block by which the lifting of weights is easily accomplished Popular Science Monthly CHAIN WHEEL weight. These long tails were produced by careful inbreeding “of fowls whose tails molted but slightly 86 Thirty-one feet of chain pass through the workman’s hand when he pulls to raise a ton one foot high. The chain works a system of gears on the well known planetary-gear principle; blocks of one-ton or ten-ton size, or more, are used for the weight-lifting required. The heavier sizes require several men. The arrangement of gears is so balanced as to distribute the weight evenly, and it prevents too great a strain being thrown upon any one part of the mechanism. The Long-Tailed Fowl of Japan N the Uyeno Park Museum, in Tokio, Japan, there are three fowls with tail-feathers from thirteen to fifteen feet long. Only the cocks have feathers of such startling length. The hens are rather commonplace in ap- pearance. The long-tailed fowls settled in Japan before the Christian era. They are probably an offshoot of a Korean variety which sprang from the jungle- fowl of southern Asia. Why do the tail-feathers grow to such lengths? Every chicken molts once a year. Chicken-growers say that sometimes a part of the chicken skips this molting season. By a process of painstaking selection and breeding, those fowls in which tail-molting sea- son is suppressed will ultimately give rise to a strain with long tail-feathers. These Japanese cocks are fed, almost stuffed, in a way that would astonish American barnyard chickens. They are not allowed to move about freely; if they did so, the precious tail-feathers would break.

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November, 1920 Learn to Interpret the Engine’s Knock HAT makes your’ motor ‘knock’? If you know, you are unique among men. There is more misinformation current among the owners of automobiles regarding the causes of this very common ailment than of all other motor ills combined. The carbon knock, recognized by a regular succession of distinct, almost metallic, sounds, as of blows on an anvil, is by far the most important knock that afflicts the gasoline motor. Now, every motorist knows that sooner or later a hard, graphitic layer of car- bon accumulates upon the piston heads, the upper portions of the cylinders and about the valves of his engine—ar. accumulation due to a too. liberal use of oil and a too incomplete combustion of gas. But why should this layer of carbon cause your engine to knock? Ask the average driver and you will get all sorts of curious By Floyd L. Darrow at the proper point in the cycle and there is no knock. This also explains why your motor does not knock when it is cold. On first starting a car in the morning the knock is absent, even on a hill, and you wonder where it has gone. It is at once apparent, however, that until the engine has had time to heat up, the layer of carbon is not hot enough to ignite the mixture. Among the numerous remedies for this knock, there is only one that is really effective, and that consists in removing the cylinder head and scrap- ing the carbon out. After scraping, the parts that have been carboned should be rubbed with fine emery- cloth and if necessary the valves must be reground. So-called carbon ‘ re- movers and burning out the Hoy Aegis sce : ” answers. The ees renee Slt OY Sr 1's carbon will give TT A most common = | = : V7 aT ay Sy temporary re error is to sup- a | BAY sali\N E ml lief only, and pose that this YU aT wee nse iT: when an engine carbon becomes so thick that the piston on the upstroke actual- ly strikes the cylinder head. When you. consider, how- ever, that the series of explo- sions going on continuously in each _ cylinder brings the car- bon covering the interior of the com- bustion chamber to a constant red heat, you have the key to the explana- tion. As the piston compresses the fresh mixture of gas and air, the hot carbon, acting like a spark from the ignition system, fires the charge before the point of maximum compression is reached. Only the momentum of the flywheel carries the piston over and prevents it from being driven back downward. The shock resulting from this premature explosion is heard asa distinct knock and it will be at once seen that the decided loss of power is due to the momentary tendency to drive the piston backward. As is well known, this knock is always noticeable when the car is on a hill or the engine is pulling hard on a slippery road. This is because at those times a richer mixture is being fed into the cylinders and the mo- mentum of the flywheel is less. Such a mixture is more easily fired and the diminished momentum makes it less easy to carry the piston by the dead point. On a level, smooth road, where the engine is not working hard, the explosions from the hot carbon and from the spark tend to come together Beware! trouble. When your engine knocks, it means Learn its cause, then remedy it is‘ badly car- boned they will not do that. A clean en- gine runs like a charm, climbs hills without difficulty, and gives a maxi- mum of power. Another very common motor knock comes from a too-. advanced spark. The proper time for the spark to appear is at the point of maximum compression, or, if the en- gine is running rapidly, very slightly before this point. But if the motor is pulling hard on a hill or slippery road, and con- sequently running slowly as well as drawing a rich mixture of gas, an ad- vanced spark will ignite the mixture too soon and a knock will result just as in the case of hot carbon. When the engine is running fast, the increased momentum of the flywheel carries the piston over and an advanced spark liberates the energy more nearly at the right point for maximum power. It actually takes an appreciable time for the combustion of the gas and the liberation of the pent-up energy to take place. Therefore, at such times, an advanced spark is necessary if all the energy is to be fully utilized on the downstroke. When running slow, however, an advanced spark liberates this energy considerably before the piston has come to the top of its stroke and tends to drive it backward. The remedy for such a knock is to retard the spark: In the case of either knock, the sound itself is produced by the play 87 between the piston-rod and the wrist- pin. The pre-ignition, as already ex- plained, tends to drive the piston downward, and this play permits a momentary pounding and the result- ing knock. It is much more noticeable Explosion should occur when pis- ton is in position 1, or at end of stroke. Because of hot carbon it occurs at posi- tion 2 in the case of hot carbon, because the very large ignition surface produces a much more nearly instantaneous combustion than does an advanced spark. A Neat Repair on an Old Table. WO valuable old _ stand-tables, heirlooms, with very heavy marble tops, were brought to me to be repaired. The work was to be done without showing any marks of repair. The heavy tops had caused the legs to give way, allowing the solid walnut center to touch the floor. Some one had tried to repair them with glue, but it had not held. I took the legs off, cleaned every- thing thoroughly, cut a recess in each leg 2 and 314 in. deep, 1 in. wide, and 1 in. long. Then I put one leg on, clamped it, and drilled a 5-in. hole through the table center and through one leg into the recess already bored. OTHER Soy Bw -———4 Lb oe — SS % BOLT-THREADED' BOTH ENDS BOTTOM VIEW OF LEG SHOWING RECESS How repairs were made to strengthen two old tables with the repair unseen The bolt-hole for the two other legs was drilled about 14 in. above the first one so as not to enter it. A small quantity of glue was also used in addi- tion to the bolts. This, by the way, is always advisable where parts are bolted together, unless the bolting is of a temporary nature and intended for making future adjustments possible. After the two tables were completed, they were exceptionally firm and not a mark showed anywhere. The repair could not be seen unless the tables were turned upside down. This was ten years ago and so far as I know the tables are in good shape today.

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” Wr HETHER equipped with an abrasive cloth disk for surfacing smali metal parts or with a sandpaper disk for finishing wood patterns, mitered frames, and other articles, the small disk-grinder is an extremely use- ful piece of apparatus in the hands of the- small-shop or home-shop man. While an ordinary grinding-stand may be easily altered to a disk-grinder, this article will deal only with its applica- tion to the small lathe. A speed lathe is best adapted to such work, though a screw-cutting lathe TABLE TILTED To GIVE DRAFT. FOR CAST-IRON DISK | woneey PATTERN SCREWED TO oe .% 4 0°)

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November, 1920 Automatic belt grind- erin use. -Works best with U. S. Abrasive Belts. Look for the MAP TRADE MARK New abrasives for Send us a trial order for your next requirements. If U.S. Abra- sives are not satisfactory in every respect, return the goods and we will allow you full credit and freight both ways. You be the judge. What could be more fair? Grinding, Polishing and Finishing Metals Out of the stress of war work grew two remarkable abrasives—Carbalox and Her- culundum. They were needed to boost production. Records had to be broken. These abrasives are now available on paper and cloth in all of the usual com- mercial shapes and degrees of fineness. For steel, brass, copper and aluminum, Carbalox is recommended without qual- ification. Herculundum is best for cast iron and similar materials. Both abra- sives are remarkable for their sharp, tough edges and ability to form more perfect cutting edges under pressure of the work. This feature is important— and is one reason why these abrasives stand up to severe work in all kinds of factories and shops. There is a right abrasive for every grade of work. No shop is too small to use them profitably. Tough, especially-made paper, strong cloth, and glue that everlastingly holds the tiny particles of abrasives, are com- bined, seasoned and inspected before the finished product is worthy of the U. S. Map trademark. tes SAND PAPER U.S. Abrasive Discs on disc grinders are time savers. Fast-Cutting Mineral Abrasives oeree em Le ‘ Flint Paper Garnet Paper Emery Paper Crocus Cloth Garnet Cloth Emery Cloth Sheets, Discs, Circles, Belts and Rolls of various widths and lengths of the above U. S. Abrasives. Carbalox Cloth Herculundum Cloth New York Boston UNITED STATES SAND PAPER CO., Williamsport, Pa. Stocks at following branch offices: Philadelphia San Francisco Detroit Chicago

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= msi te mental 30 OS OEE ROT NR LSA So 0 a ee eee teen PRL COOP ES tne ecm Deg eee Se eR CE BEER

An empty space surrounded by metal. What happens mechanically inside the lock when the key enters, you don’t much care about—provided it does happen with perfect case and regu- larity, and keeps out gentry who use everything but the key to get in. A key and a keyhole are instruments of moral welfare. They help people to stay honest. They have to be made with a con- science, too, to stand up to the worst instead of standing in with it. The outward sign of this inward grace is the name YALE on both lock and key. Sign of a stronger metal where strength is the point, sign of fewer parts where fewness makes fool-proof- ness, sign of heavier metal where weight makes for permanence, sign of a smoother finish where this means facility in use, sign of guality from conception to finish. The Yale & Towne Mfg. Co. Makers of the Yale Locks General Offices and Works: Stamford, Conn. New York Office: 9 East 40th St. Chicago Office: 77 East Lake St. Canadian Yaie & Towne Ltd., St. Catharines, Ont. Yale Made is Yale Marked

Popular Science Monthly Ingenuity Shown in an Electric Arc-Lamp ITH a few odds and ends of gas- pipe, an old iron box bell, and a mica insulating-joint such as electri- cians use on combination gas and electric fixtures, I have constructed a very serviceable homemade arc- lamp. The accompanying _ illustration shows in detail the %-in. gas-pipe RON WIRE ein

—$"piPE TEE STRAP IRON 3" PIPE NIPPLE STRAP IRON

6" PIPE NIPPLE INSULATED WIRE GLOBE FROM OLIVE BOTTLE. } INSULATING JOINT SOLDERED CONTACT 6" PIPE NIPPLE => . SET SCREW WALL-FASTENING FOR CARBON ELBOW Be ot The construction and assembly of a home- made arc-lamp made from odds and ends about the house

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g CARBON . <—— EXTENSION connections and gives approximate dimensions. The two -in. elbow- joints are those having flanges with screw-holes so that the apparatus may be fastened upon the wall. Four %- ‘in. T’s, 3 6-in. nipples, all of 1%-in. pipe and having right-hand threads on both ends, constitute the required fittings. The magnets and armature of the bell are removed and reconnected, bringing the leads of the magnet directly out instead of in series with the armature contact screw, thus making the bell mechanism a single- stroke instead of vibrating. A heavy piece of galvanized iron—sheet iron, or slate, approximately 3 by 7 in., is fastened by machine screws, stove- bolts or pipe-clamps to the top of the pipe structure, and the magnets and armature mounted upon the plate in alinement with the pipe- fittings. On the back side of the plate may be mounted a_ single-throw double-pole switch for controlling the circuit. Around the top 5-in. nipple, wind with 2 or 3 turns a piece of asbestos paper, using plenty of shellac to keep it wound tight and in place. About 36 turns of No. 16 or No. 18 iron resistance wire should be wound upon this asbestos, forming a resistance 90 By Theron P. Foote coil, the ends of which are terminated upon the slate plate mounted beneath. If this plate is made of iron in- stead of slate, the terminal screws must be well insulated from the plate. To the end of the bell-clapper solder a small piece of flexible wire about 2 in. long, and on the other end of the wire an iron washer having a hole about 14 in. larger than the carbon rods to be used. Two \% in. by 1% in. or larger couplings are placed in two of the T’s so that a large glass tube may be supported around the are, if so desired. This tube may be made from an olive bottle by cutting top and bottom with a piece of string soaked in gaso- line and tied around the bottle in the correct location for cutting. After the string is ignited from the bottom, it burns rapidly. When the flame is ex- tinguished and while the charred string is still glowing, the bottle should be immediately dipped into cold water and will be found to crack as desired. A .set screw in the bottom 3-in. nipple aids in holding firmly the bot- tom carbon. A piece of asbestos-covered wire about size No. 10 is soldered into the inside of the lowest 6-in. nipple and brought up through the insulating joint and other couplings, coming out through the nipple near the magnets and connects with one side of the double-pole switch. The magnet wires connect with the same binding-posts as the resistance- coil leads, and one binding-post con- nects with the upper carbon by means of aclamp on the carbon rod and a flex- ible connection. The other binding- post is connected with the remaining side of the double-pole switch. The positive side of the incoming circuit should also be connected with that side of the switch. As the current passes through the magnets, the armature pulls on the washer, causing it to grip the carbon and lift it up, thus forming the are. As the carbon gradually burns away, less current passes through the mag- nets, causing the carbon to sink lower and keeping it at the right distance from the lower carbon to form an are. When the armature has become lowered as far as it will go, the washer on the carbon should be low enough to strike on top of the 4-in. tee, causing it to release its grip on the carbon and allowing the carbon to fall. More current will now pass through the magnets and the carbons will be pulled apart again, the iron washer having taken another grip. This action is continuous, and with a little care the lamp can be so ad- justed that there will be no flickering of the light. . Popular Science Monthly

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November, 1920 Make It Easier to Remove > the Ashes DEVICE for the removal of fur- nace ashes is shown in the two illustrations. A car with an ashcan is drawn up an enclosed incline from be- No.more carrying heavy cans up and down the cellar stairs. This dustless elevator does it for you neath the furnace to a point outside the building. A trapdoor in the floor of the ashpit and over the can is opened by means of a rod at the side of the furnace. The ashes are pushed into the hole with a furnace hoe. The trapdoor is normally closed so as not to affect the draft of the fire. This drawing shows the arrangement of the inclined track for hoisting the full eopto = ashcan from the TRAPsDOOR cellar When the can is filled with ashes, a door made in two sections is opened at the top of the incline. The car is drawn up by means of a winch fixed to one of the sections and the filled can exchanged for anempty one. Thus the ashes cannot even sift into the cellar. Protecting Sliding Wagon Wheels from Wear EFORE descending a steep hill, it is a common practice to leck a rear wheel of a heavily loaded wagon which is not provided with the usual service brakes. This protects the wagon and its load, and also prevents the wagon running over the animals. The usual method of locking is to have a small chain attached by one end to the side of the wagon-box and to tie the other end to a wheel-spoke or to the rim itself. This method is danger- ous to the wheel, because if it were to November, 1920 SAFETY UT If your razor suits you— Stick to it If it does not — | Try the Enders. i On the market 13 years. More than 2,000,000 in regular use before it was ever advertised. Satisfied users alone have been its salesmen. Is there another product with a similar record? The appealing charm of the Enders is its simplicity—only three parts: BLADE:—of the finest quality Swedish- base steel—hand stropped, hand tested, assuring the keenest and most lasting edge. GUARD:-—stands free of the blade, leav- ing the entire cutting edge free for shaving. HANDLE:—hung at the exact angle nec- essary to secure the sliding, diagonal stroke of the old style open blade. Shaving with an Enders Razor is ‘‘ Just Like Wiping Your Face With a Towel” Tv Gnders- ENperRs SaLes COMPANY 17 Battery Place, New York ENDERS SELLS FOR $1.00 with six blades of the best quality Swedish-base steel. Packed in a black Karatol box, plush lined. FOR SALE BY BEST DEALERS EVERY WHERE. sb RR EBB POE I EAA RIE A rm Seem BAS PTET =

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Goblin Does Work Wonders! Goblin is a soap that really cleans; you can actually see the dirt disappear before your eyes. It is made of the purest and most effective ingredients; that’s why— it cleans thoroughly and quickly; lathers freely in the coldest or hardest water; does not injure the tenderest skin. It’s the heavy duty soap for the stained and badly soiled hands;—always keepa cake of Goblin on hand. At your grocer’s; if he hasn’t it on hand send coupon for a free trial size. Trial Size Cake Free CUDAHY, Dept.H 111 W. Monroe St., Chicago Canadian Address: 64 Macauley Ave., Toronto, Canada Please send me trial size cake of Goblin Soap. Your Name eee eee eee eee eee eee ee eee) eee eeeseeeseses TORR O OOH ee OOOH Eee meee eEEEOeeEseses ’ strike an obstruction or drop suddenly into a hole in the road, it would natu- rally deliver a-swift, powerful jerk to the wheel and possibly break out a spoke or fracture the rim. It also causes considerable wear to the tire by dragging it abruptly on the ground down the entire grade. A simple homemade locking device called a “slide lock’”’ eliminates all these troubles. Take a piece of malleable sheet-iron of any desired thickness (14 in. is pref- erable), and cut from it a strip an inch wider than the tire of the wheel on which it is to be used and 18 in. long. Curve the piece sidewise to conform to the circle of the wheel, and turn 1% in. of each edge upward at a right angle, leaving 2 in. of one end _ straight through which to drill a hole to receive the chain. After the hole is drilled, cut the end link of the chain, insert in the drilled hole, and reweld together, thus uniting the slide with the chain. Illustrating how the wagon slide looks when in position on a hill. It also pro- tects the wheel from wear Attach the chain as formerly by one end to the side of the wagon-box and provide a hook also in the side of the box for hanging up the chain and slide when not in service. When ready to lock the wheel, stop the team, and lay the slide immediately ahead of the wheel, where it will make sure to roll on it between the turned-up edges and drive ahead. The chain must be of proper length so that when the slide is directly under the wheel it will be fully stretched. The wheel will thus slide down on this slide lock, free from all danger of breakage and wear to the tire. The turned-up edges of the slide will prevent it from slipping out from under the wheel. There is abso- lutely no strain on the wheel when locked.—L. M. JORDAN. Heating the Automobile’s Front Seat OST flow-heaters for automobiles i seem to be designed for the rear compartment and not for the front seat. The heater shown in the illus- tration is designed for runabouts, roadsters, and particularly the type of automobile that affords no protection for the driver against cold, such as taxicabs, town cars and limousines. 92 - Popular Science M onthly Antiseptic and Germ-proof Cuts, scrapes and all skin injuries should be kept clean while they are healing. With this object use New-Skin promptly when the accident occurs. Scientific tests establish the fact that it has the power of. destroying germs of infection. 15c and 30c. Atall Druggists NEWSKIN COMPANY New York Toronto London “*Never Neglect a Break in the Skin” LET THE MACHINE DO THE WORK a More than a_ typewriter—A whole print shop, Over 365 different styles of type and languages to select from. TWO STYLES .OF TYPE, Ortwo to five different languages, carried on the machine AT ONCE. "JUST TURN THE KNOB"and change instantly from Roman to Italics,or Minature= Roman, or toBeautifut Sexrrpt; or from English to Greek, Russian, French, ws - the Multilex yon need is ze 0 i etc. ; etc, Good vwork is automatic; ‘twoe cannot get out of alignment. “*Just let the Machine do the work.’ WRITE TODAY FOR FREE BOOKLET Write your name and address on the margin oi this page NOW and mail the margin to HAMMOND TPECRATEE co. 639 East 69th Street EW YORK CITY qd Learn Piano! | ea z= 4) This Interesting Free Book shows how you can become a skilled Player of piano or organ in your own home, darter usual gest. ‘Dr Guinn s agus n eth is endorse leading ane 2 and heads of State Conservatories. Successtul 36 years. Play chords at once and complete piece in every key, within 4 lese sons. Scientific yet easy to understand. bully illustrated. For be: ners or teachers, old or youn; Diploma gran’ Write today for 64-paze free hook. ‘How to Study Music’’ M.L. QUINN CONSERVATORY, Studio IK, 598 Columbia Road, Boston, 25 Mass.

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November, 1920 _ The radiator is simply an ordinary floor radiator such as is used in hot-air systems of house-heating. The ad. justable vane type with the ribbed foot- control knob is of course the most de- sirable, as it will allow the driver to permit as little or as much heat as he desires to come through: The size of the radiator used de- pends on the amount of clear floor space. As the illustration indicates, a hole is cut through the slanting part of SEAT CONTROL KNOB HEAT. FROM VANES | ote If you equip the driving compartment of your automobile with a heater now, there won’t be any cold feet this winter the floor and the radiator set in and screwed down. -It will be found that a surprising amount of heat comes through when the radiator is wide open. A heater of this sort assures much more comfortable driving in an open car when the winter weather is severe.—FRANK W. HARTH. Holding Paint-Pail Bail to One Side HE good old-fashioned way to paint small buildings is to get the ladder and hang thereon the pail of paint while the brush is shifted from one hand to the other, as the arms tire. But the nail somctimes bends under its load of lead, and spills its two or three dollars’ worth of con- tents upon the ground. Not having a pail-hook handy, and having the above-men- tioned acci- dent happen, aman made a simple clip from two wires, with which the bail of the pail was kept at one side, thus affording plenty of room Spats walhhe hale beste e pail is held as - Sees shown in the illustra- e brusa, an tion, there will be no TWISTED WIRE. HOLES Joe | PUNCHED CLIP IN USE at the same danger of its contents time holding spilling the pail secure upon its nail in the side of the ladder. The clip consists of two lengths of wire, each 6 or 7 in. long, and twisted in the center, leaving 11% in. at the lower end and 2 in. at the upper. The ends are bent into hooks, the lower ones hooking into. two holes punched in the rim of the pail and the upper ones over the bail. The size of the clip will be deter- mined by the size of the pail being used. Published in the interest of Elec- trical Development by an Institution that will be helped by what- ever helps the ox “I’m sorry I stepped on your train, but here’s some nice new string to pull it with.” FTER a period of starvation a man needs time to build up his system again. And so our railroads need time before the tonic effects of the recent rate increase can beshowninimproved service, During the period of government control increased wages and costs for material left little over from a stationary income to buy much-needed equipment—or even to keep the existing cars and engines in order. To rebuild this equipment the railroads must secure hundreds of millions of dollars of new capital: the rate increase placed no such lump sum at their disposal. It merely gave them a chance to make a fair living, to insure reasonable dividends to their investors, and thus to attract the money of new investors. Right here is where we can help, Every dollar we place in a railroad security will have a share in buying some freight car or locomotive to bring us the goods we want when we need them. Every hour we save as shippers or re- ceivers of freight in loading and unloading the cars will enable them to get into action again the more quickly. Or as suppliers of material or cquipment we can give first place to the orders of railroads, and thus help them speed up reconstruction. So by putting a shoulder to the wheel and keeping patient, we all can hasten the glad day when the 8:05 will always be on time and we can be sure of getting that furnace for the same winter we ordered it, “ieee” Western Electric Company No 20 To do its share in restoring the rail- ° road service, from the Atlantic to the Pacific, from the Gulf clear across the Canadian border the Western Electric Company is hurrying delivery of electrical supplies to the railroads, WELL, WHAT Lae ‘ t2 ae rt Hi ‘ att | . i by p a) t cau vau At ia tah F aff. pen 4 fi + 8 4 bia) Re im Oat i i] ht Peay t ¥ ul re iv H ae a : : sa hs a oa Lt aa At i J .

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TRAFFIC JOBS 100,000: High-Salaried Men Needed! RE ag interested in quickly obtaining a big job in a new uncrowded profession eager for your trained services? Traffic Manage- ment offers you a field filledwith splendid opportu- nities now easy for you to grasp. Never before has such a chance come to you and it may never come again, 100,000 high-salaried Traffic men are needed at once, to handle efficiently the tremendous amount of traffic which is crowding the railroads and steamship companies to Ca- pacity. $3,000 to $5,000 a year is gladly paid. And now comes to you the opportunity to quickly obtain one of these fine traffic positions. Exchange Your Spare Time For A Big Traffic Job Now through the American Commerce Association you receive the help of many of America’s greatest traffic managers in preparing for this fascinating field. Because of the tremendous need for traffic managers these famous experts of the Association's staff are eager to put you on their list to be trained for one of the big positions open. i . shippers and ship owners are literally crying for trafic men. You don't have to quit your present job in order to prepare for one of these positions. Such men as T. Albert Gantt, Traffic Manager, Corn Products Refining Company; William Scott Cowie, American Freight Board Committee; Samuel G. Lutz, Vice President, Chicago & Alton R. R., and nearly 200 others of equal prominence train you quickly and thoroughly in your spare time and at a cost so trifling that any ambitious man can easily take advantage of this great opportunity. Traffic Men Earn Big Money Because They Save Their Firms Big Money It is easy to understand why traffic men arein such need and why they receive such big salaries. A traffic man recently saved his concern $24,000 on shipments to their new plant in Chattanooga. Another saved $9,751 in shipping 66 carloads in two weeks. Another saved his firm £36,000 by applying a differential rate on 1,500 cars from Pittsburgh to nada. Traffic Experts saved an automobile concern $640,000 in ten months. A traffic expert discovered that freight rates paid by the Meeker Coal Company were legal, but exorbitant. A ruling secured from the Interstate mmission resulted in a refund of $122,000. An oil shipper in Kansas was losing over $30 every day—$700 monthly—because he did not know of certain tariff regulations entitling him to lower rates. Is it any wonder that the traffic experts who can save their employers hund and thousands of dollars in freight charges are highly paid? Such knowledge can almost dictate its own salary. MAIL COUPON FOR FREE BOOK “Swap” your spare time for a big traffic job. Mai! coupon now'for free book. Explains why firms all over the country are needing trained traffic men to handle their shipping and traffic problems economi- cally and efficienily. Gives full information about opportunities open to you and how you can earn $5,000 a year and more in this interesting profession. This free book will open your eyes to a new, un- crowded profession just. as eager for your trained services as to pay you big money for them. Mail Coupon today. AMERICAN COMMERCE ASSOCIATION Dept. 1411 , 4043 Drexel Blvd., Chicago, Ill. Arerican Commerce Association, Dept. 1411, 4043 Drexel Blvd., Chicago, Ill. Please send me without obligation, your new book, “A New Profession.” and tell me how I can qualify for Traffic Management. | Address am eee How to Properly Fit Bearing-Shims HE removal of bearing-shims to compensate for wear in connecting- rods of an engine that has not seen much service is not difficult, even with those of limited experience in this line. With an old engine this is not so simple. -The connecting-rod bearings are provided with a thick metal shim and some smaller ones, and in the old engine it is advisable to file down this thick shim slightly after the bearings have worn down farther than is provided for by the removal of these thinner shims. If new shims that are slightly thinner than the old ones can he had, it is ad- visable to make use of them, as it requires some skill to file them to a perfect flat surface. Should the shims be filed, a jig similar to that in the illustration should be made wood and three screws. Con- tinue toturnthe screws into the wood until the screws are just underneath the shims. It is essential that the thick- ness of the shim after filing is as nearly uniform as possible, and thesurfaceeven at all points. If the wood is long enough (approximately 7 in.), it is quite easy to maintain a flat filing position by keeping the file always parallel to the wood surface. A very little filing will usually bring the bearing surface far enough down to remove a knock, and for this reason it is advisable to try and fit the bearing after every few strokes of the file, to guard against the shim becoming too thin.—RONALD L. PRINDLE. \ ty ~VISE JAWS vid A block of wood beneath the shim will permit it to be filed to a uniform thickness Je HI Here Is Shown a Novel Centering -Drill CENTERING-DRILL that makes a beautifully smooth seat for the lathe center is made from a piece of steel with the end formed exactly like a lathe center. A slit is cut, as in the drawing. The length of the slit is about twice thelength of the tapered -portion of the tool. The tool should be hard- ened and tem- pered like an ordinary drill. When fed into a small hole drilled for the center position, the slit allows the 94 The slit gives two cutting edges to this centering-tool from a block of . used.—J. ALEXANDER. Popular Science Monthly two halves to spring out far enough to make a cut. If too much pressure is used in feeding, the edges will be forced into line again and will not cut. The proper pressure is easily gaged, however. The tool is sharpened by grinding in the same way that the lathe center is ground. A —— Handle for a Soldering-Iron FTER considerable use the wooden handle of a soldering- iron becomes charred and burnt from continued contact with heat. A non- Soldering-iron handles soon burn off. Why not wrap as- bestos paper around the shank and have a non- burning han- dle? pte pa pata A ASBESTOS burning handle can be made in the following way: Remove the ferrule and handle and raise several sharp barbs along the end of the shank with a cold chisel. Then cut a strip of asbestos paper about 5 in. wide and wrap about the barbed shank until a suitably thick handle is acquired. Bind it tight with several turns of fine wire and you have a handle that will outlast half a dozen wooden ones. illias the Kitchen Sink with Water FTENTIMES the dishpan is too small, so we decide to fill the kitchen sink with water. This we can- not do because there is no way to stop the outlet. A convenient way to do this is to use a lead weight. To make this weight, Some cloth and a lead weight over the sink drain enable you to fill the sink with water LEAD —) fCLOTH select a can lid slightly smaller in diameter than the metallic colander outlet of the sink. A one-pound coffee-can lid is usually the right size. Melt scraps of lead on the stove and pour the molten metal into the can lid and lay aside until it is cold. Make sure that the lead does not slop over on your hands and burn you. Fold four to eight thicknesses of cloth and lay them flat on the sink drain; then put the lead weight on the cloth and fill the sink. The suction of the water and the weight make a con- tainer of the sink and you can fill it with water. In place of the cloth, one or more pieces of rubber, taken from a discarded hot-water bottle, may be nm che en ot Th of

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November, 1920 An Extra Base for the Automobile Jack HEN jacking up the car in the mud or sand, it is the usual thing for the bottom of the jack to sink grad- ually out of sight and subsequently lower the wheel until it again touches the ground: To do away with this annoyance why not carry a supple- mentary base to support the jack in such soft foundation? One suggested STEEL OR WOOD When changing atire on the road = it sometimes = happens that the 775. “pectin deep Neues wen Why not use a VT SCREWS OR wooden base and J RIVETS makethechange © ~==->--{ in comfort? Sat

2 ! Wee

is shown in the illustration. It can be made of heavy thick wood or of a large piece of sheet steel. Arrange four cleats in a position which will fit about the base of the jack and hold it fn the center of the base, thus prevent- ing it from skidding to one side if the base tips out of the horizontal. If desired, 1 clamp can be arranged to turn over one edge of the jack base so it will not lift out of the cleats when the handle is being operated. A base 8 in. by 10 in. should suffice to support the weight of a large car under such conditions.—T. HALLETT. Pipe-Fittings Make a Very Good Muffler MUFFLER that gives good re-. sults, is easily made, and costs very little, can be put together from the commonest kind of pipe-fittings, noth-

: EXHAUST PIPE PUA UA UNREAD DADE MO Mana NNN NN : ( = aan Hinnuayie nn = Sinn “es 5 =) =: = iI NYT TLD Addis = ~ PIPE eee 42 S49 pipc NIPPLE. =a eq Tots brine Fond TO Sona <<

Monn ADULT HAH LU Stationary gasoline engines make a lot of noise if not provided with a muffler. Here is the way to make a good one ing being required but seven tees and six short nipples. Screw a tee on the end of the exhaust pipe, and in each branch screw a nipple. Put on two

tees, one on each end of the first,

HE washing of heavy bed linen and blankets can be one of the easiest household duties, if théy are washed in a 1900 Cataract Electric Washer with its ex- clusive figure 8 movement! “But why,” you say, “a 1900 Cataract, in preference to any other washing ma- chine?” Because of the magic figure 8 movement! By means of this exclusive feature the soapy cleansing water swirls through the clothes in a figure 8 motion, four times as often as in the ordinary washer. Swiftly, steadily, the water swishes back and forth, going through those clothes with every motion of the tub. Thus the clothes are washed rapidly and thoroughly. The water swirls through the clothes in a figure 8 mo- tion four times as (6) often as in the or- R< dinary washer. And that shiny copper tub—the inside is smooth as one’s hand. Nota part in it to catch the clothes or to cause wear and tear. No heavy parts to lift out and clean after the wash is finished. Then there’s the smooth-running, silent wringer that also works electrically—it can be shifted from the washer clear over to the waiting clothes basket without moving the washer or requiring one extra step. The 1900 Cataract Washer ‘costs a few cents an hour to operate, and it washes the clothes in 8 to 10 minutes, clean- ing equally well the heavy clothes, and the sheer fine under- - garments or delicate blouses. IQOO CATARACT WASHER If you want to know more about the 1900, send for the interesting book, George Brinton’s Wife, a book of fiction with some surprising facts included. 1900 WASHER COMPANY, 206 Clinton St., Binghamton, N. Y. Canadian Factory and Office, Canadian 1900 Washer Company, 357 Yonge Street, Toronte

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i San il eee SH

ship! Is this your fix? The Boy Without a Bike «32.72 Left all alone again—cut off from his friends —denied their healthy fun and companion- Fun, health and quick, convenient, economical and dependable transportation to school or work. That’s what a bicycle means. What else. can you buy for so little that will bring you so much? Write today for your dealer's name and copy of handsome new 1921 Dayton Catalog No. 44 showing 8 models for men, women, boys and girls. Dayton Ticycles

Popular Science Monthly screwing them on the nipples. Then put four nipples in the four tee branches and attach four more tees. The layout is clearly shown in the illustration. The exhaust gas is broken up into a number of streams and is greatly expanded and slowed down in escaping. It will be found that there is no back pressure. V-Blocks Made of a Piece of Pipe SMALL set of V-blocks can be easily made for bench use by utilizing pipe fittings in the manner shown. First get a sufficiently large flange and bolt it to the bench in a conven- ient position. Then thread a short piece of pipe or a nipple into the i flangesoit willpro--- mK. “4m ject about 5or6in. _— Pipe Then with a hack- saw cut two V- ee shaped openings ao - the top edge of Such aset of V-blocks the pipe exactly jg ideal for handling opposite each small shafting, wrist- other. File away pins, etc. any unevenness and try to get the cuts the same size and shape, so a round rod, reaching across, will fit in the cuts without any chance of wabbling.

No Light Can Get into This Darkroom DEALER in photographic sup- plies was often asked for the loan of his darkroom, and _ several times people had opened the door, not knowing the room was in use. Of course this spoiled the plates and films then being developed. The photographer was exceedingly annoyed by this, so he figured a way by

‘i ma ard Visible Writing : Underwood,newly re- i built, yours for @ down

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We furnish guaranteed high grade stock and buy all you raise. Use backyard, barn, cellar, attic. Con- tract and Illustrated Catalog Free. STANDARD FOOD AND FUR ASS’N 407C Broadway - New York

CLEAN SMOKING) One twist of mouth piece cleans this pipe of smooth-smoking Italian: briar. Aluminum draining canal does the trick. f $1 postpaid; cash or money order. THE S & H COMPANY . & Wilkes-Barre, =.

Automobile Ignition, Valve Timing, Self-starting and Lighting, Including Ford System. A manual covering the care, adjustment and repair of the electric system of automobiles. Price, postpaid, $1.40. POPULAR SCIENCE MONTHLY 225 W. 39th Street, New York 96

Cycle Dept. THE DAVIS SEWING-MACHINE CO., Dayton, ( Ohio | aes . DARK ROOM SINK ee *14° RUBY GLASS ‘ PASSAGE STANDARD UNDERWOODS Dollars in Hares Spams, 5-Year Guarantee We pay $7.00t0618.50 and upa pat |_{ passace—f STORE

] uainue CURTAINS

Three doorways covered with heavy curtains permitted entrance to this darkroom while developing which it couldn’t happen again. He made a darkroom about nine feet square, and, as you will note by the diagram, there were three doorways, each covered with a heavy black curtain. The curtains were equipped with lead weights at the bottom so that they would stay in place at all times. With this scheme in use one could enter and leave the darkroom without danger of spoiling the films being developed.—CorA HAMILTON.

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November, 1920 An Expanding Screwdriver Made at Home“ NY instrument maker, adding- machine ' assembler, ‘typewriter repairman, etc., will appreciate: this expanding screwdriver, which is very efficient and practical. When you have to:replace a screw. in an almost enclosed corner, where you cannot use your fingers, all you have to do with this improved screwdriver is to pinch the tongues together and press it into the. slot of screw, which it will hold firmly and not drop, as would bethe case with a magne- tized screw- driver. Any u tool out of a piece of drill rod, and to save time, you can use an old screw- driver with the aid of a hack-saw and fine narrow file.—H. E. MENDE. Save Coal with This Simple Draft-Gage HE production of draft in a chim- ney and the satisfactory operation of the boiler connected with the chim- ney depend upon the pressure difference between the heated gases in the chim- ney and the outside air pressure. To operate the boiler to its maximum | advantage, especially in house-heating (for which this article is intended), it is necessary that there be some visible means of knowing this pressure differ- ence or draft. The intensity of the draft may be measured by means of the little water-gage shown in the accompanying illustration. It is easily con- structed from a piece of glass tube bent into How to measure the the shape of a_ draft in your chimney letterU. One leg passes over the top of the supporting panel and communicates with the pipe leading to the chimney or straight into the chimney itself. A_ short ‘ie length of rubber tube is used to make Here is the ordinary Prote cting the Insulation HE real mechanical strength of any portable electric cord is in the out- side covering. Once this covering wears through, the insulation is an easy prey : to hard knocks, abrasion, oil, moisture, i heat and even light—for light tends to | make rubber brittle. } "eck ae ae Duracord has a thick, heavy fabric woven like a piece of 3 . s > fire hose, not braided. cover woven like a piece of fire hose in- Picture shows outside covering only with im; Stead of the usual light braid. That’s nteinite why it outwears ordinary cords 4 to 6 times. It has unusual strength where the wear comes—on the outside. | Duracord can be furnished in all ! sizes of portable electric cord and also in the larger sizes of single and duplex cable. Ask your electrical jobber about Duracord or let us send you samples of Duracord and ordinary cord for you to test and compare yourself. TUBULAR ‘WOVEN FABRIC CO. SPORBRINRTE a ss Nine i SN ° e ‘ braided cable covering. : the connection. The difference in the Note the open and. por~ Pawtucket, R. I. ous construction, easily wrowatr Jorden the deere | Eset rt ’ p Duracord yt nda and tubular woven fabrics of all kinds water. For the convenience of reading a scale is placed between the two legs. The draft produced by a chimney may vary from 1% to 2 or more inches of water, depending upon winds, gas temperatures, and the height of the chimney. A high chimney with low gas temperature is-the most advan- TRADE MARK REGISTERED

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it iF if it Cooma nines tre i a * cage cca poo siek, mie Rete Tare EN IVER JOHNSON SAFETY REVO 4 $0 x » new . “at te ——~* peing + oe on the |ja fa hat an’ sportly, be > ‘ 4 “ epee Swag TSE wounds Man. etek vis pisht: yallins pevolver. ~ from P&=- | wees he ot A. revolve®: wnich” “ nerocty- Roose 0 a (car nis | erolmat® cg tn in Broadway aischare ses) Pa Wrill- j ne eos street yesterday we! ‘ : Co! umbus , seven it pit ke, 48-4)? Berke, oe set UP id THOMAS »o naing on, one ge fobeet ‘alte ® wy Wom)? Reproduction of an actual * newspaper clipping, but with names omitted. AUTOMATIC LV.ER This could not happen with an IVER JOHNSON A jolt—an accidental discharge— and a fatal injury. Such accidents are impossible with the Iver Johnson. It simply can’t gooff by accident. And yet its safety is automatic—no buttons—no levers—nothing to-adjust —nothing to remember to do to make it safe. Drop it, kick it, thump it, ‘‘Hammer the Hammer’’—it can’t go off accidentally. Just one way to fire an Iver Johnson—pull the trigger all the way back. At that point only the revolver responds with lightning quickness. Drawn tempered piano-wire springs make the Iver Johnson always ready for use. And the perfect rifled barrel speeds the bullet straight as a streak of light just where you aim. Choice of three grips: Western Walnut. Three Booklets—One or All Free on Request “A” —Firearms; “‘B”’—Bicycles; ‘“‘C”—Motorcycles If your dealer hasn’t in stock the particular model you want, We will supply you through him. IVER JOHNSON’S ARMS & CYCLE WORKS 343 River Street, Fitchburg, Mass. 717 Market St., send us his name and address. 99 Chambers St., New York Regular, Perfect Rubber, San Francisco Iver Johnson Single and Double Barrel Shotguns combine accuracy and dependability. Iver Johnson Bi- cycles are world- famed for easy riding, strength and durability. Models and prices to suit everyone. $15.00 A WEEK FOR: SPARE TIME WORK $60.00 to $90.00 A WEEK FOR WHOLE TIME. That’s what being -a local representative for POPULAR SCIENCE MONTHLY can bring to you. If you are willing to hustle, then we want you. POPULAR SCIENCE MONTHLY 225 West 39th Street, New York Automobile Ignition, Valve Timing, Self-starting and Lighting, Including Ford System. A manual covering the care, adjustment and repair of the electric system of automobiles. Price, postpaid, $1.40. POPULAR SCIENCE MONTHLY 225 W. 39th Street, New York Easy fo Pla Easy fo D4 | i This book tells you when to use Saxophone. leaky. in quartettes, in sextettes, orin aay band; to transpose cello in orchestra fa (ak, other you would \ e You can cons en to play the costo In one hour's practice, and = books ean double your incom gopularity. Easy to pay by our easy payment plan. MAKES AN IDEAL PRESENT @ Send ‘or free Saxaphone book and catalog of every- Sond eo. True-Tone band and orchestra instruments BUESCHER .iaiuescher Block, Eltnertstnd. o LASS PIN Si qh FREE CATALOG 2it6 2nd NGmoen in cuass Either pin illustrated made with any ann Was » amount of lettering, one or two colors enamel. Silver plate, 257 ea., $2.50doz. Sterling silver, ‘) 50c ea., $5.00 doz. Write oe “4 ne “a we want oneexclusiverepre- | FY tivein each locality to use ¥ iE, new piataaer Ext xire-t} ‘as a... Guaran ‘ res Gf one Se esac Si oe SELINGER TIRES USER COW. wme TIRE le 98 Popular Science Monthly tageous for use. The amount of draft pressure required depends upon: the kind of fuel used. Wood needs but a slight draft, only about 1% inch of water; while bituminous coal requires less draft than hard or anthracite. With a little care and observation the operator will be able to determine the most satisfactory draft pressure for economical operation of the furnace or boiler.—FRANCIS DASHIELL. A Clamp that Holds the Lamp in Position F working at a vise, it is not only necessary to have enough light, but also to have it where it is wanted. The usual type of electric lamp gives sufficient light, but is un- satisfactory because if too high, it throws a shadow of the worker on his work, and if too low, it is a hindrance. Every one knows how annoying it is to spend some time arranging the lamp until it is ‘‘just right,’”’ only to have it slip when jarred. The accompany- f¢ ing _ illustration Ca ame a shows a_ very Ci easily made lamp- = holder, by means of) of which the lamp may be arranged in aninstant. The lamp may beraised orlowered without the inconvenience ofadjustingscrews or wires; will stay in ‘that position; and will be held so that the light falls directly on the work, preventing shad- ows, and protecting the worker’s eyes from the direct glare. The upright support is a piece of iron of any convenient size; 14 in. wide by 14 in. thick is a good size. The arm of the holder is a piece of iron about 1 in. thick and 1 in. wide and of any desirable length. About 4 in. from one end of the arm an oblong hole is cut so that the upright piece may slide easily through it. The back end of the arm is cut to fit the upright, while the opposite end is cut to fit the lamp handle. At A the arm isshown before bending. The back end is then in the form of a half circle, taking care that the notch in the end lines up fairly well with the oblong hole. The other end of the arm is given a )%-in. twist, so that the lamp will be held at an angle of about 45 degrees. At Bthesupporting arm is shown after bending. The supporting arm is then slipped over the upright support. The weight of the lamp produces a clamping effect on the upright, so that any notches, screws, or wires are unnecessary. By lifting up slightly on the lamp, the supporting arm immediately slides freely on the upright. The upright may be set in a heavy base or attached to the work-bench | with screws. If the latter method is decided upon, it is advisable to make wey No screws or wires are in this holder Ponyular Sevence Maonth)y

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November, 1920 November, 1920 the supporting arm with at least one joint, so that it may be swung out of the way if desired.—R. H. CAsPrEr. How to Keep the Typist’s. Papers in Order HEN typing multiple copies of a letter the stenographer is usually annoyed by the sheets and carbon paper curling up. Try as she will she cannot keep them flat. Whenever this occurs in our office we attach a paper clip to the end of

PAPER4

Just try putting a clip on your copy sheets. It will hold them down without curling the top sheet, which weights the other copies down and permits us to con- tinue the work without further trouble. Try this idea next time you have this difficulty and see how it enables you to go ahead immediately.— M. A. OSBERG. A Way to Mill Keys from Flat Stock HOULD a number of keys have to be made all alike, they can be made on the milling machine, using a thin cutter or a metal slitting-saw. The tapers can be set off on the divid-

This illustration shows the most economical way of making the cuts ing scale of the machine, so that they all will be alike. By arranging the cuts so that the keys will come ‘‘heads and tails,’’ there will be a minimum of waste material. All the cuts at one angle can be made at one setting, and an- other setting made for all the rest of the cuts. The finished flat stock sup- plied by the steel people lends itself very well indeed to work of this char- acter, as it can be had in any width or thickness, and ground flat and true to the required gage. After the necessary number of cross-cuts has been completed, it is necessary simply to make one longi- tudinal cut at the end of the cross- cuts to separate the keys and to re- move the burrs. :

“HANES” the national | nameplate on =< OY underwear is : | an unfailing guide! ELASTIC KNIT Hanes Guarantee: “We guarantee Hanes Underwear absolute- ly—every thread, stitch and button. We guarantee to return your money or give you a new garment if any seam breaks.” UY “Hanes” winter underwear for men on the strict business basis of the most unusual quality, comfort and service ever sold at the price! Buy “Hanes” with your eyes shut, or over the phone—buy it without the slightest inspection, if need be, because : Every garment bearing the “Hanes” nationa/ nameplate returns in wear and in absolute satisfaction far more than you pay for it—more than you ever before got out of an undergarment! Confidence you will have in every “Hanes” thread, stitch, buttonhole, seam, or reinforcement can never be misplaced. Our guarantee is your safeguard. It proves our faith in “Hanes”! It is your protection! “T_ JANES” underwear is made in heavy weight and medium weight Union Suits and heavy weight Shirts and Drawers. (Illustrated in this advertisement.) The new medium weight Union Suit, carrying the yellow label, has been added to meet the demand of indoor men. It is made of full combed yarn and silk trimmed. “Hanes” Union Suits have the popular snug fitting tailored collar- ette and elastic knit arm and leg cuffs that will not gap; closed crotch that stays closed; flat, unbreakable seams; an extra gusset assures unusual comfort across the thighs; buttonholes last the life of the garment; pearl buttons are sewed on to stay! Shirts have the snug fitting elastic knit collarette. Drawers have a wide, easy fitting, 3-button sateen waist band that adds so much to the wearer’s comfort. “Hanes” for boys Buy “Hanes” Union Suits for boys if you seek more warmth anc more wear than you ever bought before. This extra-value under- wear duplicates the men’s Union Suits in all important features with added fleeciness that appeals to the boys—and to mothers! Made in sizes 20 to 34, covering ages from 2 to 16 years. Two to four year old sizes have drop seat. Four desirable colors. See “Hanes” Underwear at your dealer’s. If he cannot supply you, write us immediately. P.H. HANES KNITTING CO., Winston-Salem, N.C. New York Office: 366 Broadway Warning to the trade: Any garment offered as “Hanes” is a substitute unless it_bears the “Hanes” label. Now S'umnarur-N ou Vl want to yorar ones Naraseek Vite Sui! UNDERWEAR.

99

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hat PIECED eg SNe ee awe we. $2,500 to $5,000 a Year Earn big pay and win swift promotion! Get out of the rut and qualify for a real, big pay job!. Be an Electrical Signal Engineer. Op- rtunities in this big, new field are unlimited. he work is simple and easy. to master —we teach you at home in ew 8 time. Two Big Outfits FR EE If You Act Now! A complete drafting set with special drawing instruments, triangles, curves, etc.—also, co plete signal outfit with model miniature ens a a , a es

s = way, signal sumapheres, bells and lights— } both absolutely free to those who decide SIGNAL": to enter this fascinating big pay pro- ENGINEERING

fession now. Write for Free Book Write to-day for our new Free Illustrated book | on Electrical Signal Engineering. Find out a } the golden op etastiion of this interesting. Dis pay game. & how you may a high- salaried, teuportent member of this great pro- fession. You ——— no obligation. Send a postal to-day. Addre DEPARTMENT ¢ OF SIGNALLING Dept. 1208, 1924 Sunnyside Ave., Chicago, Ill. | ane

course \ Secret Services ORE Finger Print Experts are M needed. Men who are masters of this profession are scarce. The demand for Finger Print Experts is great. Asaspecial inducement we will give you free of charge our new easy reading course in Secret Service Intelli- gence if you act at Once. Be a Finger Print Expert Build up a business on a basis of a trained brain. You can do it asa master of the Finger Print profession. There is crying need for Finger Print Experts right now and the demand for these trained men is growing every day. A profession that offers wonderful op- portunities for advancement. Govern- ments, corporations, police depart- ments, institutions and individuals have constant use of these specially trained men. The work is fascinating and The Pay Is Big! No special education is necessary. You can become a master of this profession by studying at homein your spare time. Expert Finger Print men travel all over the country solving mysteries that baffle all others. They areimportant men and highly regarded ardenvied by everyone. Mail the Coupon Get full information about this great profession and our big offer of a free course in Secret Service Intelligence. The mastery of these two closely allied professions places a brilliant career within your grasp Achievements that will immediately place the stamp of suc- cess upon you, are now possible. Send this coupon for full inforntation NOW. University of Applied Science

Desk 1208, 1920 Sunnyside Ave., Chicago Gentlemen: Without any obligation whatever send me your new FREE book on Finger Prints and your offer of a free course in Secret Service Intelligence.

Popular Science Monthly ‘A Tap-and-Drill Table in a Metal Soap-Box By Theron P. Foote VERY man who shaves himself has his own particular make of soap. I have been using the twenty- five-cent size shaving-stick, and when I finished with the box I always gave it to the baby to play with. The other day I found one on the floor and, putting it in his box of toys, noticed that he had eight similar boxes. With a little thought I have placed a number of those little boxes to very good use as a dirt-proof decimal equivalent , and tap-and-drill table for my tool- box. : I first sineaasiiel a portion of a wooden rod having a diameter of 1 5/16 in. and 33in.long. Finding the

To the man in the shop this tap-and-dril]l is invaluable center, I started a small hole, later to be used as a guidance hole for a screw, in each end. I then laid out in the center of a large sheet of plain white paper a tabulation similar to the one in the accompanying sketch, allowing 1 in. for the decimal-equivalent scale and V4 in. for the tap-and-drill scale. This I filled in with typewritten numerals and then neatly pasted the strip around the wooden block. Clamp a 34-in. iron pipe nipple in a vise and placing the soap-box over the end, with a small hammer carefully flatten out the threads. Then mark the box as shown in the illustration and cut out the sections with a sharp cold chisel. Find the center of the bottom and top of the soap-box and drill a hole in each, using a No. 30 drill The wooden anew is then placed in the box and a 34-in. No. 6 round-head nickel screw fastened from the bottom into the guidance hole of the cylinder. This screw should not be drawn up tight, as an allowance should be made so that the cylinder may revolve in: the box. Now fitting the cover on, the screw through the cover into the end of the cylinder should be drawn up tight, so

that the cover and cylinder are one. 100 44 Any loose tension between the cover and box may be taken up by tighten- ing the screw in the bottom of the box. Revolving the cover shows at a glance the decimal equivalent for any sixty-fourth of a unit in the first four holes, that is, the first and third holes show what part of the sixty-fourth;

fos ts =a Fe | Ye tp oe Ea Wi —+ 64 alr

Mark the holes as shown here and cut with a sharp chisel in theillustration the 15 and 47 denote 15-64 and 47-64, while the second and fourth places give their respective decimal equivalent. The second row of figures shows the tap and body drill to be used with a given size of tap, that is, as in the illustration, for an 8 by 32 tap, a No. 28 drill should be used if the material is to be tapped, whereas if an 8 by 32 machine screw is to

a - 3%. a Vick $4 ht — 4 FG ot F fe ¢ $a ox & x 7X3 6x3 5X x3 OK 2x am Such a table as this should be pasted . on the rotable cylinder in the box

Pysre TeP 24D UP TO TH/$ 41NEL pass through the hole without being threaded, in other words, a clearance hole, use a No. 18 drill. It didn’t cost a cent and it has saved a lot of time and bother. Try it. Protect Your Garage and Car from Fire N spite of every precaution, gasoline is sometimes spilled in the garage or shed in which an automobile is housed and it is not always due to carelessness that the spilled gasoline is ignited. An extinguisher of the squirt-gun type, and filled with car- bon tetrachloride or trichlorethylene, shou'd be in every garage.

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November, “$100 a Week, Nell! Think What That Means To Us!” ‘‘They’ve made me Superintendent—and doubled my salary! Now we can have the comforts and. pleasures we’ve dreamed of—our own home, a maid for you, Nell, and no more worrying about the cost of living! “‘The president called me in today and told me. He said he picked me for promotion three months ago when he learned I was studying at home with the International Correspondence Schools. Now my chance has come—and | || thanks to the I. C. S., I’m ready for it!” | Thousands of men now know the joy of happy, prosperous homes because they let the International Correspondence Schools prepare them in spare hours for bigger work and better pay. CALS LE PRS peepee PELE is NP NS EE TSS SIE Caan Seb oh eS NE IE SS ee PO Page a = at a ek rs I sheer (“treanationll 00 HERE wee mews cme sere en Why don’t you study some one thing and get ready | INTERNATIONAL , GURESPONDENCE SCHOOLS for a real job, at a’salary that will give your wife and children the things you would like them to have? a... x Toe me, how I can guality, for the posi- Explain or in “a subject, before which I mark X. ENGINERR and Railways Pr | You can do it! Pick the position you want in the | work you like best and the I. C. S. will prepare you for it right in your own home, in your spare time— you need not lose a day or a dollar from your present ; | | : | I ] ENGINEER Draftsman occupation. ® Yes, you can do it! More than two million have done it in the last twenty-eight years. More than 100,000 are doing it right now. Without cost, without Railway Mail Clerk atin OPERATING Ante Spanish Sateen | French Poaltry Raising Italian HEATING orker or Supt ° ° i Name. obligation, find out how you can join them. Mark and 4 Pasat, mail this coupon! OG eet , City State Conadions may cond 7-28-18

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nee et a ee : (fristmas GIETS is, UC 25H) Be Je aut ‘ ag b\: an: me) XO ' aid ~ 101 $145°% a 4

10 Months to Pay The Royal Way HORTAGE of ready money need not prevent é ~ from giving your i ef ¢~4 loved ones the Xmas hh Gifts they long for —buy on Credit. The cost of a cheap, tawdry,imitationgift will go far towards the payment of a enuinearticleon The oyal Credit Plan. Rare Xmas Values >: We have a large stock of the most beautiful and \ desirable Diamonds, Fy Rings, Watches, Toilet ‘\ Sets and other Gifts. Bs These are rare Holiday Bi Values at amazingly low as s

oO SSeS: = aSee

I 3 ad af aes ‘y is 207 h-420°° 265 a aknoas Buy Now For Xmas is The Xmas rush and 9j¢ consequent mail conges- tion will soon be upon py. us. Make your selec- #! tion NOW and to be sure of getting exactly fe what you want on time, W you can buy now as well as later, for in buying the Royal Way, you is have Ten Months to Pay No money in advance. Order now—pay 20% upon examination and balance in ten equal monthly amounts. See and examine any selec- tion. Then, if pleased, send first payment and the balance in easy monthly installments. Money promptly refunded onany unsatisfactory pure chase, if returned within 10 days. Liberty Bonds accepted. 10% discount allowed for cash.

“en Tere ~ ~ We | beused for two or proof paint would i ina + -.J three hours, then serve the pur- Ve ‘ia BATTERY later one globe pose nicely. If Pin may be screwed thecurrent taken from the rectifier To the left is a unit of the battery; to the right is the wiring diagram et, out of the sock- and so on

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I Built This Dandy ~ __ ay Moving Stairway ie a: MECCANO Ps oe? i gs me These Models Your Fingers Will Tingle with Eagerness To Build These Wonderful Models ITH Meccano you can build hundreds of fascinating models in shining steel and brass, and with your Meccano Motor, make them run like real machinery. Say, but it’s loads of fun! . Think of building a Crane that lifts weights and swings them anywhere at a touch of your hand—an Electric Locomotive that pulls a train—a Lighthouse with lights that flash red and white. Yet you can easily build these and countless others just as interesting. You can have a new toy every day. The Get thi more you build, the more you can build. A tai You don’t have to study a bit. Read the simple instructions and the fun is on! ea , : xX Meccano building is a glorious, absorbing, Prisco manly sport for every day in the year. i It builds over 100 models Tell Dad nothing will do for Christmas but Petess of Meccano. MECCANO OUTFITS B No. Dopeeeeeteeeeeeneess $200 De BAR cece cece eeresecece ° Send for FREE XMAS BOOK te. 2%:2:::::05055 os end ror - 1 iieecrpeeaete $50 ss : : oi | NE ke ca wiePcas ab deat 9.00 called ‘‘Meccanoland.”” Contains the inventor’s No. 3X.................. 11.50 own story of Meccano and over 50 pictures of And up to $40.00 models and boys building them. Just the thing MOTORS to help you and Dad to pick out your Xmas gift. icstrie, Mavarsina....... $4.50 Doesn’t cost a cent. Get yours early! Electric, Non-Reversing.. 3.00 Clockwork Motor........ 3.00 Transformer............. 3.25 MECCANO COMPANY, Inc. Outfits and motors sent prepaid on receipt of price if not at your dealer’s., Div. K, 71 W. 23d Street New York City ~CSt snd mentors alightly higher \ MECCANO Toy Engineering for Boys | 108 Cem See ee Bee fe i f |

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ee fs i ie ah DO meee AP. Bes ROE He 08 Sty OLSEN : Your Choice 75c a Week With every set is included — FREE —a Consulting Membership which gives you the privilege of submit- ting your perplexing problems to a corps of experts for an entire year. i This Consulting Membership regu- larly sells for $12.00, No matter what your occupation, one of the home study sets listed below will quickly fit you for a better job and bigger pay. Any set you select will be sent for seven days’ examina- tion, and if you decide to buy you may pay the rock- bottom price at the rate of only 75c a week. But you must act now! The rising cost of paper and binding materials won’t permit us to continue the present low prices much longer. These books are the work of recognized authorities. They are written in plain, easily understood language, by recognized authorities, and contain hundreds of photographs, diagrams, tables, etc., that make diffi- cult points as simple as A-B-C. Handsomely and dvrably bound in half or full morocco leather (except as noted), and stamped in gold. Pay-Raising Books At Greatly Reduced Prices Accountancy and Business Management, 7 vol., 2700 pages, 1000 pictures. Was oT ae ies eae aaa Now $29.80 Carpentry and Contracting, 5 volumes, 2138 pages, 1000 pictures. Was $37.50. Now 24.80 Civil Engineering, 9 volumes, 3900 pages, 3000 pictures. Was $67.50 ......... Now 39.80 Electrical Engineering, 8 volumes, 3000 pages, 2600 pictures. Was $60.00 ...Now 34.80 Automobile Engineering, 6 volumes, 2600 pages, 2000 pictures. Was $45.00....Now 29.80 Machine Shop Practice, 6 volumes, 2300 pages, 2500 pictures. Was $45.00...Now 29.80 Steam and Gas Engineering, 7 volumes, 3300 pages, 2500 pictures. Was $52.50, Oe gh 5 eS 2 See 29.80 Law and Practice (with reading course), 13 volumes, 6000 pages, illustrated. Was EE ens ck Soo os oke ne Now 49.80 Fire Prevention and Insurance, 4 vols., 1500 pages, 600 pictures. Was$30.00 Now 19.80 Telephony and Telegraphy, 4 volumes, 1728 pages, 2000 pictures. Was $30.00 Now 19.80 Sanitation, Heating and Ventilating, 4 volumes, 1454 pages, 1400 pictures. Was Se eS i eee Now 18.80 Drawing, 4 volumes, 1578 pages, 1000 pic- tures, blue-prints, etc. Was $30.00...Now 19.80 Send No Money Shipped for 7 Days’ Trial Yes, we'll gladly ship any set right to your home or office upon your simple request. Pay only shipping charges when the books arrive. Don’t send a penny until after you have used them seven days, then re- mit only $2.80 or return them at our expense. Pay balance at the rate of $3.00 a month—75c a week. Act now—while these splendid books are being offered at 20% to 50% less than regular prices. This offer is open to every person within the boundaries of the U. S.and Canada. Grasp your opportunity— fill in and mail this coupon NOW! American Technical Society, Dept. X208, Chicago American Techical Society, Dep. X208, Chicago, U.S. A. | | American Technical Society, Dept. X208, Chicago, U. S. . | ce LE ee eee | will examine the books thoroughly and, if satisfied, | - 7 DAYS’ examination. shipping charges collect. | | will send $2.80 within 7 days and $3 each month, until I have paid the special price of........ If I decide not to keep the books, I will notify you at once and hold them subject to your order. Title not to pass to | me until the set is fully paid for. [ SRE CES 55s Gb apo o 6 chSTT DORR SESORG 2 01000 db ecccee | | PIB? ow 555 wins cn cicccinn onwcewews secede eesecs sees | | EET TT PTL ORT TCL rT rt ee eee OO SES A A ST A A ST “until the last hour of the charge per- haps one light will be enough. In general, storage batteries should be charged more rapidly tor the first hours than later. If the rectifier is kept cool, the battery may be charged at night and thus require but little of the motorist’s time and the battery will always be ready for service on the car. There should be a switch in the alternating-current circuit to cut off the rectifier when not in use. Rectifiers of this type are not of very high efficiency, that is, more current goes in on the alternating side than can possibly be taken from the direct side, but even the cost of charging at home, if it is rightly done, will be less than the price paid at a service station, to say nothing of the convenience afforded by always having the battery ready for service. When it is seen that the total cost of this apparatus is less than five dollars, even if all parts have to be bought new, it is obvious that it will yield a big interest on the investment. It should be noted that the wire which leads from the two aluminum plates that are connected, is the posi- tive wire on the direct-current side and should be connected with pole of the storage battery marked Z. It is also important that pure aluminum be used for the plates. Some aluminum on the market is too impure for good results. The aluminum plates should be at least 11/16 in. thick and it might be advisable to have them heavier. This homemade rectifying device for charging storage batteries is de- signed to give satisfaction on a 110-volt alternating-current circuit. How to Notch Sectors on an Ordinary Lathe TOOTHED sector is_ easily notched out on an ordinary lathe. Mark off the tooth positions on the edge of the sector. Mount a milling cutter of the desired form on a mandrel Showing a sim- ple way of notching a sec- tor on a lathe SECTOR 1c IN PLACE. OF H—1 | TOOL-POST in the usual way. Bolt the sector to the tool carriage, using a bolt that passes snugly through the hole in the hub with the head in the tool-post slot. The teeth can be milled out one after another. If great accuracy is required, a gear with the proper tooth spacing may be attached to the sector and used as a guide in connection with a stop to enter the gear teeth. Any one who has a lathe in his shop may also employ the method described in the foregoing for cutting the teeth of small special gears which he may require in constructing models of machinery. 104 Popular Science Monthly Two Great Books on Alternating Currents I Experiments with 110-Volt Alternating Currents This really wonderful book by J.D. Adams explains what can be done by the amateur electrician with the 110-volt commercial cir- cuit. It shows how the 110-volt commercial circuit may be handled with perfect safety and without involving the expense necessary to maintain a power supply. It is written so clearly that everyone can understand it. There are profuse illustrations and dia- grams which show exactly how you can make these experiments yourself. The only way to gain a thorough understanding of electricity, as it is used commercially, is by direct personal experiment. The knowl- edge thus gained is of vastly more value and importance than that acquired from the performance of the stereotyped series of battery experiments so uniformly described in the text-books. The many ex- periments described in this book were all performed at home and notina machineshop or laboratory. The apparatus involved was nec- essarily made as simple as possible consistent with the securing of striking results. Fully Illustrated, Price Postpaid, $1,75 Construction of Small Alternating Current Motors By PROF. A. E. WATSON Brown University This book contains complete in- structions for building small alter- nating current motors in several sizes. The designs will be found in harmony with those of the very best manufacturers and they can be worked out by the amateur for - making useful instruments. Some of the subjects taken up are “Characteristic Features of Alternating Current Motors,” “Construction of a One-Half Horsepower, Single Phase Induc- tion Motor,” “ Procedure in Testing and Using an Alternating Cur- rent Generator or Synchronous Motor.” Clear, concise directions and careful drawings are features of this book. Price, $1.75 Fully Illustrated. . Popular Science Monthly 225 West 39th Street, New York

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November, 1920 An Envelope Trick, or the Mysterious Message HE “gentleman from the audi- ence” being shown an apparently empty envelope, is asked to place a message inside it, then seal the enve- lope. This he does, and is amazed to see the performer immediately . tear open the envelope and draw out a AN AWD N BA S N . g WS aN WS NN SAM QS WY AQ A WU SS AW GCN WNW I N \ YAN NY) \ ee \X F.RKEINY, KE. CUT HERE went This trick is performed by inserting a cut envelope inside a whole one return message which has, in some mysterious manner, replaced the original note. The method is as follows. Two envelopes A and B are used. They are precisely the same shape, size and color, but B is cut around three sides, which permits it to fit nicely into A. After trimming, B is really in two sections, 1 and 2. After placing B in A, the reply is inserted between A and B, toward the address side. The flap of A is now gummed to flap B, and a seem- ingly empty envelope is ready to be shown the gentleman from the audi- ence. Making Machine Screws from Rivets N an emergency, a very respectable machine screw can be made from a round-headed rivet, either brass or iron. All that is necessary is to thread the shank with the stock and die, and with the hacksaw make a slot in the head. A convenient woop way to hold a short rivet for threading is to place it be- tween two blocks of wood wae gem and put the a machine screw made blocks in the from a round-headed rivet vise, pressing the rivet head into the wood with as much force as is necessary to prevent it from turning. A little‘ powdered rosin will help a good deal in holding the rivet station- ary. The blocks should be made of hardwood. + samme em Nanoemher 1990 Make This Test Watch how your teeth respond All statements approved by authorities This ten-day test has shown to mil- lions the way to whiter, safer teeth. It is a free test—you should make it. No other method known can do what Pepso- dent does for teeth. To end the film The object is to fight the film, which dims the teeth and causes most tooth troubles. Dental science has worked years to do that. Film is that viscous coat you feel. It. clings to teeth, enters crevices and stays. The ordinary tooth paste does not combat it satisfactorily, so brushing leaves much of it intact. It is the film-coat that discolors, not the teeth. Film is the basis of tartar. It holds food substance which ferments and forms acid. It holds the acid in con- tact with the teeth to cause decay. Millions of germs breed in it. They, with tartar, are the chief cause of pyorrhea. Thus all these troubles have been constantly increasing, despite the tooth brush. Now we combat it Dental science, after years of search- ing, has found ways to combat film. High authorities have proved them by clinical and laboratory tests. The best dental opinion now approves these methods. Leading dentists every- where are urging their adoption. Millions of people, as a result, now employ them daily. The methods are combined in a den- tifrice called Pepsodent. And a 10- Day Tube is offered free, so all who will may quickly know how much it means to them. Five Much Desired Effects One ingredient of Pepsodent is pep- sin. Another multiplies the starch diges- tant in the saliva to digest the starch deposits which cling and form acid. It also multiplies the alkalinity of the saliva, to neutralize the acids which cause tooth decay. Two factors directly attack the film. One of them keeps teeth so highly polished that film cannot easily adhere. Pepsodent combines the best that modern science knows to combat the Pepsaodéent REG.U.S. The New-Day Dentifrice Ascientific film combatant com- - bined with two other modern req- uisites. Now advised by leading dentists everywhere and supplied by all druggists in large tubes. great tooth destroyers. It has brought A new era in teeth cleaning. Watch it act 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 teeth whiten as the film-coat disappears. You will see several new effects, and the book we send will tell you what they mean. This is too important to forget. ‘ Cut out the coupon now. 1 0-Day Tube F hae - THE PEPSODENT COMPANY, Dept. 902, 1104 S. Wabash Ave., Chicago, IIL Mail 10-Day Tube of Pepsodent to oor er ee eee eee eee eee eee eeeeeeeeeeeeeee coe eee eee emer eee eee eeeeeeeeeeeeeeseee Only one tube to a family 105 Mite ie te aro? Ssemrenesane eessseseresaacaamaseaeeteasatsenaans —easasaaiacaseaeae aaa og STS QE

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ith sine UR Nir one" Days + noe Se POP Att ts epee tek Es GOS ALT BLL AERIS. Lhe eee eg ves sedate, Wadukddiniyinatied Roney eat ate ta Bega BECOME AN EXPERT CCOUNTANT Unusual op ——- everywhere await expert accountants. azard business methods must give way to efficiency. orn means a greater demand than ever before for the mantrained in modern accounting. $3,000 to $10,000 a Year Great organizations everywhere want the expert business analyst. They need the man whocan show them where they stand—who can map the whole sit- uation in figures—who can suggest ways to eliminate waste of time and money and tell why and how to authorize expenditures in certain directions — who can tell what the real income of the business is and how to put economical policies into operation. The man who can do al) this and who can put effi- cient organization into the office or factory is the man wanted now. He is the man for whom im- portant executive positions are open. Get Instruction from the LaSalle Experts The LaSalle method will train you by mail under the direct supervision of William B. Castenholz, A. M., C. P. A., former Comptroller and Instructor, University of Illinois, assisted by a staff of Certified Public Accountants including members of the Amer- ican Institute of Accountants. Analysis and Organ- ization, andthe principles of Accounting, Auditing, mercial Law and Scientific Management all made oT ow you will be given special preparation for the C. P. A, examination. Train by Mail Hold your present position while preparing for a higher one. Only your spare time is needed. Thoue sands of men have won quick advancement and in- creased salaries this way. Begin your preparation now. Enrollment also gives you free use of our Con- sulting Service which brings advice on any business problem whenever you want it. The cost of LaSalle . training is small and you can pay on our easy terms —a little every month if you desire. Write Mail the coupon and we will send you full particulars—also our valuable bogk. “Ten Years’ Promotion in One,” and our book, * wa containing evidence from men who have ae to high positions thru this course of expert training. LaSalle Extension University The Largest Business Training Institution in the World Dept.1183-HR Chicago, Illinois Please send me catalog and full information regarding the course and service I have marked with an X below. Also a copy of your book, “Ten Years’ Promotion in One ”’ all without obliga- tion to me. =a Higher Ac- { Training for positions as Auditors, countancy 4 Comptrollers, Certified Public Ac- countants, Cost Accountants, etc. Other LaSalle Training Courses LaSalleis the largest business training institution in the world. It offers training for every important business need. If interested in any of these courses, check here: : Business 0 Banking'and Finance Administration O Bookkeeping p TrafficManagement— [) Commercial Spanish Foreign and Domestic O Production Efficiency pusiness English C BusineseLetterWriting "Coaching for C. P: A. 0 Law—Bar,LL.B.Degree [] “and Institute Examin- 0 Commercial Law ations 0 Public Speaking . Name Present Position Harvesters Can Be Made on the Farm ORN is one of America’s big crops, and its magnitude alone would suggest the difficulty of the task in harvesting the immense _ acreage. Moreover, corn-harvesting is limited to a few days if the feeding value of the fodder is to be completely realized. Speed is essential to cutting the corn for silage or fodder. Hence the value of a platform harvester which can be purchased or made at home. The illustration shows the one-row har- vester. Two men with a platform harvester and one horse can cut and shock as much corn in.a day as three men cutting by hand. This machine is a sled platform or a platform mounted on small wheels, with knives attached for cutting the stalks. Homemade platform’ har- vesters can be mounted either on sled runners or on wheels. The harvester is pulled by one horse and cuts one row at atime. Two men ride on the plat- form to catch and support the stalks as they are knifed. When cutting corn Speed is essential in the cutting of corn crops, and here is the machine that will attain that speed for fodder, the horse is halted when the shock is reached, the operators carry the cut corn to the shock, return to the cutter, and proceed toward the next shock. The original cost of a platform har- vester ranges from twenty to fifty dollars, depending on the make-up of the machine. Devoid of many mov- able parts, the repair bills are almost negligible. Sharpening the knives usually represents the expense of upkeep. It is estimated that the machine can be operated at a cost of twenty-five cents an acre. Cutting corn with a corn-binder is much more expensive, taking no account of the expense of acquiring a corn-binder. Making a Good Boring- Bar from Steel Tubing VERY simple and satisfactory boring-bar can be made from a piece of steel tubing, 2 plugs, a long bolt, and a viece of steel for the cutter. A slot is cut at any desired place in the tube to hold the cutter, the slot 106 Popular Science Monthly being just large enough to allow the steeI-to pass through. : One end of the tube is plugged and the plug centered for the back center of the lathe. The other end is also plugged and is drilled and tapped for:a fine-threaded steel bolt. The center for the head- stock end is formed in the head of the bolt. The cutter is placed in position in its slot and the bolt screwed in. This idea can be carried further if it is desired to make a bar with two or more cutters, so that two or more cuts One boring-bar may be used for one or more cutters, as shown here can be taken at the same time. If two cutters are required, for instance, make two slots at the desired distance apart. The screw will come against the nearest cutter as before, and between the first and second cutter there is a round bar that will be forced against the second cutter when the first cutter is jammed against it by the screw. Any number of cutters might be used, or a single cutter put in any place on the bar, by using a number of slots with suitable rods or distance pieces between them. An Emergency Spark-Gap for a Weak Cylinder HEN a certain cylinder misses regularly, it is an easy thing to locate, but when every cylinder misses, then one is very apt to use harsh lan- guage. The illustration shows how to make a cheap spark-gap which can be applied to each of the BRASS STRIPS spark-plugs. ADJUSTABLE | A glance at ~4 yoke | oe the gap shows whether that particular cylinder is getting the current. Then Emergency spark-gaps made again,aspark- from strip copper and fiber gap seems to increase the voltage of the current and tend to cause ignition, even if the plug is sooted or short-circuited. The device is made from two pieces of strip copper, or brass, about }4 in. wide; one bolt or binding-post, and a strip of fiber or hard rubber. The illustration shows how these parts are assembled. Be sure to slot one of the brass strips so that it can be slipped backward or forward to adjust the gap. Rn en mem ©) © Mert’ Mi.__3y —— rH - oft oh ot ht OF OAD OU os. oh me 4A FR mt hm ht he Ut OE ole ltt ea FF weet beet PF TP as FA thew n-—_ wk ow ok ee Ok

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bie « me OD ( ( me November, 1920 The Square of the Distance Explained by Geometry F the rays from a single source of light are allowed to fall upon screens as indicated in the illustration, the amount of light which the first screen receives would cover the surface of four screens of the same size placed at double the distance. This fact is made clear by drawing the lines through the corners of the screens as shown. Furthermore, since the light is spread over four times the surface at double the distance, the intensity of the light is reduced to one fourth. That ex- plains why lights grow dim so quickly as we go away from them and so rapidly increase in intensity as we ap- proach them. In technical language, the light is said to vary inversely as the square of the distance. Thus, if the distances are 1 and 2 units, whether feet, yards, or miles, the inten- sities are in the inverse ratio of the Geometrical reasons for the ratio of dimi- nution of lighting power with distance square of 1 to the square of 2; or in- versely as 1 to 4. In other words, the intensity is one fourth as great when the distance is doubled, just as the drawing indicates. This square of the distance idea is met with so frequently in scientific work that the study of it in its various phases is important, particularly to the youthful experimenter or mechanic who likes to know the reason for things instead of blindly applying rules and formulas. All forms of energy radiating from a center are governed by this law.—H. C. RIDGELY. How to Square a Timber by Reflection HERE are times when one wishes to square a timber and has no square at hand. To take chances on squaring by the eye alone is risky, but here is a way that it may be squared by the eye and still run a good chance of making the cut square enough for all practical purposes. Look at Fig. I. This shows the saw placed across the timber as nearly square as possible by the aid of the eye alone. To do this properly, use a saw that is polished so the reflection of the timber can be seen easily. Now, tip the saw from left to right and change the angle of the teeth with reference to the sides of the timber until, with the blade held as nearly perpendicular as Y fe Refinite Soft Water will lower your Operating Costs aa pt Branch Special Di 300 5. Mich NEW YORK, SAN FRANCISCO, 1116 Nat’1 Assn. Bldg. 419 Cal! Bldg. ATLANTA, MINNEAPOLIS, ae Hurt ag 703-4 Plymouth Bldg. CINCINNATI, 410 Traction Bldg. ST. LOUIS, - SPOKANE 438-9 Boatmen’s 1015 Old "Nat'l Bank Bank Bldg. Sales Rooms, igan Ave. aS a | UN ry, ° F HARD water is going into the boilers of your power plant, into the dyehouse of your textile mill, into the washroom of your laundry or the laundry department of your hotel, hospital or other similar institution, you are carrying an unnecessary and easily avoidable operating expense. Refinite Water Softeners have proven this fact for users in all parts of the country. By their saving in fuel, in supplies, in equipment re- newal, in time and in labor they have quickly written their costs from the books—and then keep right on adding to the profits. EFINITE RIVAL OF THE CLOUDS TRADE mar Nature’s Water Softenei Copyright 1920—The Refnite Company The Refinite Water Softener attaches to the cold water supply line. Occupies little space—requires no expert supervision, practically no attention—built in sizes to suit all needs—reasonable in price. Refinite softened water is ideal for beauty parlor, barber shop and for home uses. Fresh, clean, velvety soft, it is soothing to the skin, beneficial to the complexion, delighful for the bath and shampoo. LIME-SODA WATER SOFTENERS—FILTERS We build also the Refinite Rapid Pressure Filter and the Booth Lime-Soda Water Softener. The latter is designed especially for railroads, municipal- ities and the larger steam power and central heating plants. Let us give you particulars about a Water Softener for your use. No obligation. Address our nearest office. THE REFINITE CO., Refinite Bldg., Omaha, Neb. Refinite Mineral Factory, Ardmore, S. D. Equipment Assembling Factory, Omaha, Neb. Member Associated Manufacturers of Water Purifying Equi ne See ibe eae i SSeS eee eee aed OEE hese ep ee oe! ESE ae Sea re aera NS a ne Wes 9 a a ys

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Se aR EE ATES MA TI Mechanical — Engineering Learn at Home! Employers everywhere are looking for men with mechani- cal ability. Splendid salariesand rapid advancement are offered. There is an easy, delightful way in which you can learn right at homeinsparetime. For - 29 years the International Cor- respondence Schools have been giving men and women just the training they need for success in mechanical engineering and more than 200 other subjects. Hundreds of thousands have stepped into good positions through I. C.S. help, but never were opportunities so great as now. Let the I. C. S. help you. Choose the work you like best in the coupon below, then mark and mail it today. This doesn’t obligate you in the least and it will bring you information that will start you on a successful career. This is your chance. Don’t letit slip by. Mark and mail this coupon now. ee owe ee eee TEAR OUT HERE Ot ee = eo eee INTERNATIONAL CORRESPONDENCE SCHOOLS BOX 7700, SCRANTON, PA. Explain, without obligating me, how I can qualify for tho position, or in the subject, before which I mark X. ELECTRIOAL ENGINEER SALESMANSHIP Electric Lighting ana Kys. ADVERTISING Electric Wiring Window Trimmer Telegraph Engineer Show Card Writer Telephone Work Sign Painter MEOHANIOAL ENGINEER Railroad Trainman Mechanical Draftsman ILLUSTRATING Machine Shop Practice Cartooning Toolmaker BUSINESS MANAGEMENT Gas Engine Operating Private Secretary CIVIL ENGINEER BOOKKEEPER Surveying and Mapping MINE FOREMAN or ENGR STATIONARY ENGINEER Marine Engineer Ship Dreftsman ARCHITECT Stenographer and Typist Cert. Pub. Accountant TRAFFIC MANAGER Railway Account: at Commercial Law GOOD ENGLISH Teacher Common School Subjects CIVIL SERVICE Oentractor and BRullder architectural Drafteman Concrete Builder Structural Engineer Railway Mail Clerk PLUMBING AND HEATING AUTOMOBILE OPERATING Sheet Metal Worker Auto Repairing Textile Overseer or Supt. Navigation Spanish CHEMIST AGRICULTURE Freneh Mathematics (J Poultry Raising Italian Name Present Occupation. Street and No. City. State. as Canadians may send this coupon to 7-25-19 OT di Schools, Montreal, Canada possible, the image of the edges of the timber will follow. the real edges in a perfectly straight line. When this con- dition occurs, it will mean that the saw-blade is at exactly rignt angles to the timber. If the reflected sides do not follow the original sides in a straight continuous line, you may feel sure the saw is not at quite a right angle. ; Of course, remember that the blade must be held perpendicular at all times while making the cut to sever the timber properly between top and bottom face.as well as across. A method of mitering at a 45° angle is illustrated in Fig. 2. This is a trifle more complicated, but nevertheless is one that can be mastered quickly, once understood. First, make a mark A across the board which cuts it square. Then place the farther teeth of the saw at the point. where this mark cuts the outer edge of the board X. Now move the nearer teeth of the saw away from the mark so it touches the inner edge of the board as near a 45° angle as \\\\ \ \ war\\* \\\ = \ \\ \ \ \ \ \\ \\\ \\ ~ \ \\ ~ . Ati ‘hE ~ at | \\\ = In the absence of a carpenter’s square you can square a timber by reflection as shown in the drawing you can judge. Hold the saw perpen- dicularly and look at the square formed by the lines D and A on the board itself and lines B and C in the reflection of the cut A and the farther edge of the board. If these four lines form a perfect square, you may feel sure that the saw is crossing the board at an angle of 45°. Look directly down upon the board and slightly to one side of the saw when viewing this reflection. While these methods may not be correct enough for fine carpentering, they will suffice for heavy work. First Aid for the Flash- Light Battery HEN one is in most urgent need of an emergency light, it often happens that the old flashlight is “dead.” The following first-aid treat- ment has often saved such a situation: Remove the battery and slip the individual cells out of the cardboard tube. Take out the bulb and with it test each of the three cells, completing the circuit by means of a knife-blade or some other convenient piece of metal. It will frequently be found 108 Popular Sevence Moniny Mother: . Sometimes, in the night, Pain comes to your house. . Then.is the time, most of all, when you rely on good old Musterole. No fuss, no bother,no worry—no mess- ing about with plasters or waiting for water to heat. Quickly you go tothe Musterolc jar. A bit of that clean white oint- ment on little Bobbie’s ehest, and lightly yourubit in. A gentle tin- gle of skin puts Doctor Nature to work, and soon a healing warmth reaches the congested spot. Then comes a soo coolness, and Bobbie drowses off to sleep. For coughs, congestions, bron- chitis and croup, Musterole is uncommonly effective. It is goed, too,todrive away the pains of rheu- matism, lumbago and neuralgia. Musterole relieves — without discomfort. It is better than a mustard plaster, with all the virtues of the old-time plaster but none of its disadvantages. Musterole does not blister. And itis easy to apply. Just rubit on. Rub it on—for little Bobbie’s cold —for Sister’s bronchitis—for Grandma’s pains in chest or back. It’s an old-fashioned remedy in a new-fashioned form. Keep a jar handy. Many doctors and nurses recommend Musterole. 35c and 65c jars. $3.00 hospital size. The Musterole Co., Cleveland, Ohio BETTER THAN A MUSTARD PLASTER BE AN AUTOMOTIVE EXPERT! XPERT Automobile and Tractor Me- chanics are in demand everywhere. Well trained men earn big money. YOU can qualify for these positions. We teach you by daily actual practice under skilled instructors. Experience in training thousands of mechanics for U. S. Govern- ment, Course include all branches of automobiles, tractors, welding and tire vul- canizing. Day or even- ing classes. Our free catalog tells how we train men to occupy ex- pert automotive posi- tions. Send for your copy now. Motor Institute, Ine, 2698 University Avenue S. E. Minneapolis, Minn. ELECTRICAL ENGINEERS’ HANDBOOK This book is a handy reference of Useful Tables, Mechanics, Electricity and Magnetism, Direct Current Dynamos and Motors, Electric Batteries, Alternating- current Apparatus, and many other kindred subjects. Pa pages, 238 illustrations.. Price $1.00, postpaid. Science Monthly, 225 W. 39th St., N. Y. City eee ~, isn setae (ot en en owe ee oe eS

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November, 1920 that one of these small cells has-deteri- orated more than either of the other two (especially if its zinc covering is eaten through in places). Replace in the battery tube the two cells that will individually cause the bulb to light feebly under the above test. Now bend in the form of a U a small piece of wire or a convenient strip of metal and place same over the end of the ex- hausted cell. This should now be inserted in the battery tube so that the WIRE OR FLAT METAL

\—_g@00p ceits—7 The exhausted cell is short-circuited and merely used as filler final arrangement is as illustrated in the illustration. Of course, the effect is of short- circuiting the dead cell and of using it only as a “‘filler’’ in the battery tube. Its resistance in circuit stops the current otherwise available from the two better cells. With this first-aid arrangement, however, sufficient light can often be obtained to supply the emergency.—M. M. ELLIS. The Right Way to Plane a Curved Surface PIECE of wood can be planed with a surface curved lengthwise, using a straight plane, if the trick is known, and if the wood is thin enough to be somewhat flexible. Simply fasten the wood down to the bench with a support under it so that the under side will have the curve that is required on the top. Then plane the top perfectly straight. When the wood is released, it will spring back to its original form

If the wood to be planed is held as illus- trated in the drawing, the result will be a concave surface on the upper side and one side will be concave and the other straight. The same plan can be followed in metal work, where only a slight curve is needed. Even cast iron can be sprung a little, and the piece can be fastened down on the bed of the planer or shaper and planed while sprung, giving a curved surface when the piece is allowed to resume its natural form.

Dont be a Slave to a Machine The machine shop spells opportunity and big pay. It is the starting place of great inventors and designers. Machinery, appliances and all sorts of things needed in our daily life. The big world of industry revolves around the machine shop. You can win success through the machine shop. You can reach a high position at big pay—if you avoid one danger—if you take care not to become a slave to one machine all your life. 27 ENGINEERS TEACH YOU MODERN SHOP PRACTICE Here is the way by which you can know all there is to know about machinery. Here is a way by which you can put yourself in line for quick promotion, or to be your own boss. 27 Mechanical Engineers, Designers and Specialists in shop methods and management have combined to produce a spare time reading course that will make you familiar with all details of Modern Shop Practice. Whether you are apprentice, mechanic or shop foreman, or whether you are a man on the outside with a desire to know machine shop methods and practice, this great reference library brings you the information you need. Six Volumes Shipped Free f You are not asked to buy them now. You are simply asked to write for a 7 days’ free trial of this six volume set of ‘‘Modern Shop Practice.”’ Just pay the small shipping charges when the books arrive. Send the coupon and the 6 books will be shipped to you at once for 7 days’ free examination. Ask any mechanical expert what he thinks of them. If you and your friends do not consider them worth several times their price, send them back to us, and you won't owe us a cent. If you keep them, simply send us $2.80 within 7 days and then $3.00 a month until you have paid us this special introductory price of $29.80. What the Books Teach | Consult Experts Without Cost It sets forth simply and clearly a everything you want to know— _ If you order ‘‘Modern Shop Prac- all details of shop management, tice’’ at once we will enter your name production, metallurgy, manu- for a regular $12 Consuiting member- facturing, welding, die-stamp ship in the American Technical So- ing. tool design, tool making, | ciety for the period of a year. This foundry work. molding, cast- | entitles you to the advice and counsel of our staff of engineers on any prob- ing, ame, pees er mechanical drawing, machine lem you may have within the scope of the books. drawing and design, and automobile shop work.

Six splendid volumes bound in Only 10c a day flexible American Morocco, gold stamped, 2300 ges, 2500 illustra- tions, photographs, drawings, diagrams, tables — everything to make it easy for you to learn; all this comes to you in this magnifi- cent six-volume set op MODERN SHOP PRACTICE, which has gone through six editions and which has helped to promote ° Cogpeeenee of mechanics into well-paying positions as en- PARTIAL LIST OF CONTENTS gineers, shop superintendents, Shop Work — Shop Kinks — Gear Cutting] shop owners, etc. —Turret — Lathes — Screw Machines — : Manufacturing—Shop Management— Send No Money Right Metaliurgy—Welding—Die Making—Metal now Stamping—Tool Making—Punch and _ Die tear off, fill in and mail the Work—tool Design—koundry Work—Mal- coupon. No money in advance. leable Practice—Forging— Pattern Making— No obligation. You owe it to Molding Practice—Mechanical Drawing— yourself to inspect these books Machine Drawing and Design—Automobile ae F pet home and see if they Shop Work. will not prove salary-boos bexees AMERICAN TECHNICAL SOCIETY “<== som

coupon at once, Dept. M-208 oy eeipedeaeminy CHICAGO oo AMERICAN ILL * TECHNICAL . ? SOCIETY ¢ Dept. M-208 of CHICAGO, U.S, A. @ Please send me, shipping o*. charge collect, set of Modera @ Shop Practice for seven days’ free ® examination. If I decide to buy, I will alance at $3.00 a month until $29.80 7 has been paid. Then you send me a re- v7 .ccipt showing that the $45.00 set of books and AA $12.00 consulting membership are mine, and v7 _fully paid for. If I think that I can get i without the books after the seven days’ triai, will return them at your expense. ee ee ee ee es eee eee eee eee ee PA send $2.80 within seven days and the .

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ee oe aS ee oe Sa aa eA MRT Senta ar eenen nes See ere a apa apteremnrereeetney ranean Ss PA igen eA t The Paper Famine and your copy of | Popular Science Monthly You should have a heart to heart talk with your news- dealer if you are going to make sure of your copy of Popular Science Monthly regularly every month. You must insist that your newsdealer place a standing order for your copy, and that he saves it for you. There is a paper famine. There is no where near enough paper to go round, and as a result, Popular Science Monthly, and every other magazine, can only print a limited number of copies. We have told the newsdealers, ‘‘You cannot waste a a single copy of Popular Science Monthly. Order what you actually need, but no more. Your customers should place their orders in advance.”’ In self-protection, therefore, please do one of these two things right away :— 1. Place a standing order with your newsdealer for Popular Science Monthly. Every newsdealer in the United States can get a regular supply of Popular Science Monthly by writing to us. 2. Order a yearly subscription now and thus be sure that your copy will be delivered regularly to your house. Do one or the other of these two things right away and make sure of receiving Popular Science Monthly every month. SUBSCRIPTION BLANK Popular Science Monthly, 225 West 39th Street, New York. Enter my subscription for one year. Enclosed find $3.00. oeoreereeeseereeseeeeeeeeeeeereeeeeeeeeeeeeeeseeeeeeeeeeees eeereeree ees ere ese eseee ees eevee eeeeeeeeeeeeeeeeeseeeeeeeeese coereeerererererer eevee ee ee Fee eeeeeveeeeeeeeeeeereeeeeeeeeeeeeeeeees 110 a) Popular Science Monthly An Efficient Method of Grinding Lawn-Mowers ARLY fall is the time that the >, lawn-mower should. be cleaned, sharpened, and oiled to be put away for the coming season. At this time, too, the average small machinist is crowded with work along that line and. perhaps finds it hard to keep up with the demand, especially at the fag end of the summer season. One machinist doubled his mower-sharp- ening capacity by establishing a fixed bench in his shop for the sole purpose of lawn-mower grinding, and has gone about it in the following manner. He uses power and can sharpen them almost as fast as his helper can place the machines on the bench and take them away. ; First he arranged two heavy upright bolts in the bench about 15 in. apart. A flange was fitted to each one as shown. Then two pairs of clamps were turned out of soft iron stock. Each section of a pair was drilled in the center with a hole which was a loose, sliding fit for the bolt. One side of each section was gouged out in a shallow groove. Then a section was slipped over each bolt, grooved side up, and rested on the flange. The second sections were then CLAMP mer fit K | CLAMP DETAIL FLANGE BENCH LAWN-MOWER This machine spins the lawn-mower’s blades so that they will be uniformly and quickly sharpened slipped over the bolts, grooved sides down. Then a wing-nut was threaded down over the tops of each bolt, and serving to force the clamps together. The handle and shaft of the lawn- mower were removed as well as the traction wheels. The blade drive- shaft was fitted with a temporary pulley which could be slipped on and off at will. The machine was then taken and placed upon this stand so the tie rod between the two sides rested in be- tween the grooves in the clamp blocks and the cutting-bar rested at the bottom next. to the bench. Then the wing-nuts were tightened up and held the machine securely in position. The pulley was belted up to the source of power so the action on the blades was to reverse their motion from normal. It is necessary that the clamps are held high enough by the flanges so that the disks clear the bench by an inch or more. If the cutting-bar adjustments are under the bar instead of over it, the clamps can be loosened, the machine swung up from the bench until the screws can be reached, and then let down and reclamped.

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November, 1920 . The. sharpening is done by setting the cutting-bar so it touches the blades hard enough to slightly jam them, then starting them to revolve about thirty to forty revolutions a minute, reversed in motion as before stated, and touch- ing them occasionally with a brush dipped in some valve-grinding com- pound. It will not be many minutes before the blades are evenly ground their entire length and all touch the cutting- bar with equal pressure. The Electric Lamp as a Cooking Device N egg can be electrically fried and other small cooking done with the aid of an ordinary lighting- bulb—the bigger the better—and a tin can. Put the bulb in the can, as shown in the illustra- tion, and set the cooking utensil on top, and wait for the result. Less heat will be wasted if the outside of the can is cov- ered with a layer of asbestos. With a large can bent to an oval shape, and two bulbs, even better results can be obtained.— HOWARD GREENE. FRYING-PAN

Frying eggs with an electric-light bulb Measuring Distances by Means of a Wheel T takes two men to stretch a tapeline when measuring land, but one man can do the job quicker and better with an old buggy wheel rigged up properly. Make two shafts out of 3-in. scantling about 6 ft. long. They are attached to the wheel-hub with an axle made of a long bolt. The opposite ends of the shafts are spread and a

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Earn $250—$300 a Month Thereisan urgent demand for skilled draftsmen. Companies are issuing calls every day for men to fill positions_paying from $250.00 to $300.00 per month. Work is light, pleasant and profitable. IInstruct You Personally I am a Chief Draftsman of a well known firm. I know just the kind of train- Yes, I will give you this complete drawing outfit absolutely free. The instruments are regular draftsman’s working in- struments, in a handsome plush lined folding case. Besides, I will give you absolutely free, a 20 x 25 inch drawing board, a 24 inch T square, a 12 inch rule, a supply of drawin curve, pencils, erasers, thumb tacks, etc. you at once. You have them to work with from the very first day.

paper, two triangles, a French he complete outfit is delivered to Send Coupon Put your name For Big Book Pet your name coupon and send it to me some. I will send you my new book, “‘Successful tsmanship’’, and ny great special offer. No obligation. aasee8 Getin line for a bi in ition. Get- ting the book ‘and fail particulars of Fl Chief the special offer is the first step. e Drafts- PayAsYouWish 9” ..27325 What I wantistheright kind Chicago, tll. of men. Don’t bother about &. Without any obligation C2 expense. I will give you an ne. ‘ RiSecceestal

ing needed by men who get the big salaries. ook, 9 [train you with actual, practical work the eS | rod Draftemanshio.”” 02d, tal kind that you must be able to do to hold chargeaverysmall .¢® _ ‘Personal instruction’ offer te permanent, big paying positions. I give fee for training you ff “om. you my individual instructions. I see [53 An.cxperi: @ you through. Correct you. Help you Youcanpaythe 17... quickly _become an expert draftsman oavea” Ka SOOO CO eee eee reese sees eee eee ° and designer. Best. y o Chief Draftsman Dobe ra PNR a dss Socenddeunesedccquauneesen occcces Dept. 1368, 4001 Broadway Chicago, Ill. & -eepmemac noe DCG ORG. Kcecccicdcervesses Wb cadicniion

Post SEXUAL ILLUSTRATED By WINFIELD SCOTT HALL,M.D.,Pb.D. SEX FACTS MADE PLAIN What eve ufg man and Every mi ween should know $1 00 What every young husband and Every young wife should know id What every parent should know Mailed elon Cloth bigding—320 pages—many illustrations pper t request Table of & ‘

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B you play quaint, dreamy Ha- music or latest songs on the Ukulele you will be wanted everywhere. We teach by mail 20 simple lessons; give you free every course a genuine Hawaiian Ukulele, music, verre thing —no extras. Ask us | eo the story of Hawaiian music, ou will loveit. No obligation, absolutely free. The Hawaiian Institute of Music i400 Broadway, Dept 44-M, ew York

In running over the ground, the wheel measures the distance and rings a bell every so many feet round piece of wood inserted about 18 in. long for a handle. A _ second spreader can be inserted halfway down if desired. The sketch shows roughly how a bell can be rigged up to strike at each revolution of the wheel. A pin pro- jects from the rim of the wheel and 4 LyfoL0r

io< Ne OPERATORS NEEDED NOW — GOOD PAY — RAPID PROMOTION Men and boys needed for Merchant Marine, Big Land Wireless Stations, Railroad and Telegraph Companies, Commercial Concerns, and Lake and Ocean Steamships. Salaries to start $125 a month plus Board, Lodging, and Laundry, which meansa total of $200 or more a month. One of our recent graduates is getting $6000 a year. Chance to see the world or locate in land station in America. E COURSE BY MAIL. Some of our students have actu- ® ally passed the commercial examinations in ten weeks. One student secured his license in eight weeks. Start studying NOW in spare COMPLET ght By Mail DD D< Dest a” con \ time at home. We furnish FREE to every student, an automatic m transmitter and receiver, which sends you messages just as you would receive them from a distant station. your enrollment; it beco: our course. Write today for FREE You t receive this instrument efter mes your perso’ roperty upon completion BOOK o particulars. ; abe! feepemmes |) NATIONAL RADIO INSTITUTE, Deg. 357, 14th Sis,N.W. Washington,DC ik. a

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alae eenernee ge miles reer ey ee

Can you play a man’s part? [F some one should make an insulting remark in the presence’of ‘your mother, sister or sweet- heart, wouldn’t you be ashamed if you could ‘not take her part? eae . ae &. Or if you remonstrate with a man for striking

a smaller man and-the bully-turns on you, can you hold your own? ten Or suppose one of your pals says “Come on, put on the gloves and have some fun,”’ can you do it and get any ‘‘fun’”’ out of it? To play a man’s part whenever called upon you must know how to box and how to defend yourself against a violent attack. Here’s how you can learn easily and quickly. The Great New Course Marshall Stillman’s great new course in boxing and self-defense is now ready. It contains the most com- plete lessons in boxing, wrestling, jiu-jitsu, etc., ever preparei. It beats his old cou’se that thousands of pupils thought wonde-ful and beats it a mile. The lessons sta*t with simple movements, such as the breast str >ke in swimming, holding out your hand for acoin, etc.,and step by step you are led into strik- ing heavy blows, guarding, ducking, feinting, side- stepping, etc., just as if you had a real opponent before you. When you've mastered the fundamentals, you take up shadow boxing,in which you are taught such blows as the Bennie Leonard Triple, the Mike Donovan Double, etc. Then follow lessons in the best blows and guards known tothe ring. When you've finished you'll know what blows to use, when to use them, and how to guard against your opponent’s blows. To complete your t’aining in self-defense, you’re taught 15 jiu-jitsu holds, and 8 holds in standing wrestling for use against violent attack; how to dis- arm an opponent with pistol, dagger or club; how to break a strangle hold, etc. There’s a set of daily exercises, including the Colon Exercise (one of the best remedies for constipation) and Synthetic Breathing, a great lung developer and aid against nervousness. An article on Mass Boxing shows how to teach boxing to large numbers of men. Then there’s a short criticism of all sports such as baseball, tennis, football, etc., and a history of 69 famous prize fighters with their pictures— and “inside’’ stories about them not generally known. There are over 246 illustrations in the entire course. SEND NO MONEY We send the entire course (6 books) on approval. Keep it ten days, practise the lessons, and then return it or send $5 in complete payment. Mail the coupon now to Marshall Stillman Association, Suite F-111, 461 Fourth Avenue, New York. ecxeeveewanwaee: COUPONe ew enw was a = Marshall Stillman Association Suite F-111, 461 Fourth Ave., New York You may send me your complete new course in Boxing and Self Defense, including the extra instruction described above. I give a pledge that you may feel safe in trusting me as agreed, and that I will either return the course or remit $5 (Canada $6, foreign countries $7) within ten days after I receive it. RR ye a ee ee eee SEND NO MONEY uality fine count per- a a Sooo

jeshirts. t extra large, roomy @ armholes. This season’s latest black, blue or laven- der stripe effects on white background, ave money— Wri fore this astounding offer is charges, "You poy caly 500. es. ‘ou 3:00. |. Just send Jour name, 2 —_ bartd size.

and neck! BERNARD, HEWITT & COMPANY . Dept. R4911 900 West Van Buren Street tttncle, | strikes the hammer, pulling it back: _ When the pin passes, a spring pulls the hammer back and strikes the bell. Measure the distance around the rim of the wheel and divide into equal parts so that short distances can be computed. ready to ring the bell, a mark should be at the very bottom of the rim. Each time the bell strikes means one revolution or so many feet traversed. A Testing- Rod Indicating 7 Lishdd dda [7222222221212 AAS Errand SEE, <Q eC) Cheatin iia TERMINAL 1S TAPE NON-CONDUCTOR PLACED ON CABLE OF CONDENSER N N NY ESSSSssy SMTSITsTs

If there is current passing through the wire, this instrument tells the tester that it is dangerous to work upon it

The condenser, which is mounted on the tip of a test-rod, consists of two metal cylinders separated by “linotape” insulation. As the area of the cylinders is small and the distance between them is comparatively large, the capacity of the condenser is very limited, and it will have a high im- pedance which will limit the current passing through it. One electrode of the Geisler tube is connected with the . outer cylinder of the condenser and the other electrode is connected with a binding-post on the rod shield. Worn-Out Saws Still Have Their Uses NE of the large manufacturing concerns uses old band-saws, which were formerly thrown on the scrap-pile, for lining flumes for sand and gravel. -The old blades have been found so well adapted to this use, owing to their hardness, that. the manufacturers re- ferred to not only use up their own old saws, but purchase blades discarded by other concerns. They last three or four times as long as bands of the

average structural steel. he When the pin is just .

Popular Science Monthly : SOMETHING NEW ~ “DEFENDER” POCKET KNIFE A two bladed pocket knife and pocket fire- arm combined, discharging any standard .22 calibre short rim-fire-cartridge, blank or ball. Protection in the home for ladies and gentle- men, also a high-class pocket knife. Nickel silver finish, handsome in appearance.

‘Size, 3 inches long by 34 inch wide. NOT A TOY. NO RECOIL. Only article of its kind made. PRICE $5. Postage prepaid. UNITED STATES SMALL ARMS CO. Rochester, N. Y. Arithmetic of Electricity A practical treatise on electrical calculations of all kinds reduced to a series of rules. $1.50 Postpaid. Popular Science Monthly, 225 West 39th St.. New York

Diamond Bargains en Just Released Unusual conditions force us to offer man great bargains ae a 2 gh owners }~ —4 Ah bgere The values we often & to the pub- cai an n bulletin are price ed so low that we challenge comparison at 40% more. Write at Once for Great Diamond Loan Bulletin Write us for our splendid Bargain Bulletin of mar- d joaned money on valuable

velous pamend values. wer pare 1 P mor '. self how much cheapo: y can buy from Us. tite today. Send your name oniy for the latest bulle- = — just J but only a few. Weite ES cow before you're toolate. Hurry. ; . L. Goldman’s Sons, Dept. 1368

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DYNAMO BUILDING for AMATEURS A practical treatise showing in detail the construction of a small dynamo or motor, the entire machine work of which can be done ona small foot lathe. Full instructions with drawings. Will run a sewing machine or small drill press. Price, postpaid, $1.10. Popular Science Monthly, 225 W. 39th St., New York

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November, 1920

POSITION AUTOMOBILE ENGINEER REPAIR MAN

CHAUFFEUR

Put Your Name On This Pay-Roll Men like you are wanted for big-pay positions in the fascinating field of automobile engineering. We have made it easy for you to fit yourself for one of these positions, You don’t have to go to school. You don’t have to serve an apprenticeship. Fifteen automobile engineers and specialists have compiled a spare time reading course that will equip you to be an automobile expert without taking any time from your present work.

AUTO BOOKS 6 Volumes Shipped Free Now. ready for you—an up-to-the-minute six- volume library on Automobile Engineering, covering the construction, care and repair of pleasure cars, motor trucks and motorcycles. Brimming over with advanced information on Lighting Systems, Garage Design and Equipment, Welding and other repair methods. Contains everything that a mechanic or an engineer or a motorcyclist or the owner or prospective owner of a motor car ought to know. Written in simple language that anybody can understand. Tastefully bound in American Morocco flexible covers, gold stamped, 2650 pages and 2100 illustrations, tables and explanatory diagrams. A library that costs thousands of dollars to compile but that comes to you free for 7 days’ examination. Only 10c a Day Not a cent to pay in advance. First you see the books in your own home or shop. Just.mail coupon and pay express charges when books arrive. You can read them and study them for seven whole days before you decide whether you want to keep them or not. If you like the books send only $2.80 in seven days and $3.00 a month until the special introductory price of $29.80 has been paid. (Regular price $45.00.) Along with the set goes a year’s con- sulting membership in the American Technical Society.

Partial List of Contents More than 100 Blue Prints of Wiring Diagrams Explosion Motors Weldin Motor Construction and Repair Carburetors and Settings Valves, Cooling ubrication Fly-Wheels Clutch Transmission Final Drive Steering Frames Tires Vulcanizing Ignition Starting and Lighting Systems Shop Kinks Commercial Garage Design and Equipment Electrics Storage Batteries Care and Repair Motorcycles mmercial Trucks Glossary

¢ Dept. 4 A208 7 AMERICAN 7 TECHNICAL (Regular price $12.) This great bargain offer must soon , SOCIETY be withdrawn. Send No Money Don’t take our word for it. Now See the books without cost. There is so much profit in this offer for you, that we 7 4 urge you to waste not a moment in sending for the books. Put the coupon in the mails today. 7 Mail The J: examination, shipping charges collect. will send $2.80 within 7 days and the balance at $3 a month until ne $29.80 has been paid.. Then you send me a receipt showing that the $45.00 set of books and the $12 Con- sulting Membership are mine and fully paid for. If I think I can get along with- 7 Chicago, Illinois / Please send me the 6-volume set, Automobile ngineering, for 7 days’ If I decide to buy, I Send no money—Just the / out the books after the seven days’ trial Coupon For ‘ coupon ! These Books American Technical Society, Dept. A208 Name.. I will return them at your expense. MGS. 5 ois 00k CREE OA a oe Cee ss ss See RGM iss io cheek < eh pees thine Ves beeen Chicago, Il. 7) "me

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THE EVERLASTER Always On the Job Whether you ride a bicycle to work, to school, or for pure enjoyment, you require reliable tires. The longer the wear and the fewer the punctures, the greater the satisfac- tion from your wheel. The Kokomo Everlaster gives you every ounce of service that can be built into a bicycle tire— —a thick, white, resilient rubber tread that has demonstrated its sur- passing wear —unusual strength through its two- ply motorcycle fabric foundation . —leak-proof valve construction by its three-way splicing to the casing —a handsome, twin-grip tread with a continuous easy-rolling center rib and two rows of sharp, gripping wedges to give traction and avoid skidding. Sent Free—The Kokomo Bike Book. It gives a lot of interesting bicycling information and tire hints. Every rider should have one. Kokomo Rubber Co. 40 S. Main Street Kokomo, Indiana “* Contributors to Cycle Trades of America Advertising Campaign.”

i c LON S —- Lf FL BICYCLE WIRES

A Mirror to View the Inside of Elevated Objects OR inspecting the condition of inverted lights, high shafting, | house gutters, or any object at con- | siderable height which is in such a position that it cannot be viewed from the ground, the mirror herein described will be found useful. Procure a round automobile mirror of the style shown. Solder a rod to the back which will extend beyond the socketed end nearly as far as that end is from the mir- ror. Fit the end of a pole with a- bolt a through the a stock to which MIRROR, the socket of ' the mirror can be bolted. = Set up the To MIRROR nuts lightly so the mirror will BOLT 1 swing freely but not loosely. | ps Then attach a cord or wire to . & the end of the rod and lead down the pole through eyes to the hand. A finger ring at the end of the wire will facilitate pulling. Opposite the cord set a light spiral spring between the mirror shank and the pole. A light bamboo pole or fishing-rod can be used. The mirror is raised to the desired position and the angle altered by a gentle pull on the cord so the object can be seen. «®

This rod and mirror will enable you to see the inside of elevated objects How to Make a Rain Visor for Your Automobile HEN it rains against the wind- shield the view of the road is uncertain and chances of accident are increased. Windshield cleaners are good, but they keep one working. This visor has been devised to prevent the elements from striking the HOLES FOR TACKS

NAILED al INSIDE OF TOP Attached to the top of your automo- bile, this tin visor prevents rain or snow from fogging your vision glass at all and is a great help to driv- ers in stormy weather. As most auto- mobilists keep their tops up during winter, it can be fastened permanently in place, for that season at least. Cut out a piece of sheet tin the de- sired length and so it can be bent about as shown in the perspective | sketch. The top edge follows the line 114

Popular Science Monthly Ne

=o | th .... . 36,85 Insured for six months’ wear m DURATEX Guaranteed Shirts a Good quality Percale, full coat cut, well re- inforced where the wear comes. Neat Fall patterns, fast color. State preference of pattern, color. Don’t forget size. . £73 endsheshirvecomete ostpaid. MONEY BACK IF NOT SATISFIED. Fail Catalog 5; -dcsctadileumendianeam furnishings. GOODELL & CO.,611D Duratex Building, New York “i Largest mail order haberdashery house in the world

h Woe! a — A baking , ua PSs ’ oo aoe those who iL From the ee moid the world’s destiny. 9 is jeans. I SO UENG i sos sant. paver fe Jour hams ing. mbolesome, 3 the precisa 6 pa would appreciate a it er, whit puts everything clearly, ap | ¥. 3 it is. Send Te to show that you a ae ae Fy —~ e Pathfinder a ight t. ~ Woe! ag i not repay us, Fue PA a to ipvest a new friends. Address: 483 Langdon Washington. D.C.

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Noanember. 14620 November, 1920 of the windshield edge of the visor, and should. be punched with several holes so that it can be tacked to the inside of the front bow of the top. Make it just low enough so that it will ward off the snow or rain, but not too low to prevent the driver from watching the road. Be sure the side shields come as close as possible to the glass without touching, as they will help to keep drafts from sucking in |: the snow or rain at the sides. When enameled a suitable color to match the car, it will not be unbe- | coming or conspicuous in the least. Numerous Uses for the Electric Iron HE electric iron used by the house- wife is like the electric fan—it has many other valuable uses than that for which it was intended. » The writer, returning from an ‘automobile -trip; found a large gap ‘the size ofa silver dollar cut in one of the tires. : Not having any portable vulcan- izer on hand, the gap was cleaned, filler applied, and the electric iron set over it to vulcanize the patch. Need- less to say it was whole again in a very short time. (Fig. 1 at A.) In the illustration an inner tube at B is ROINNER TUBE WATCH= REP RR 'FIG.2 \METAL STAND \LEATHER r BELT yj ARON ) G~ nea FIG.3 H Fig. 1. The iron vulcanizing an inner tube. Fig. 2. Asawater-heater. Fig. 3. Drying a glued belt. Fig. 4. Soldering a tin pan being treated likewise. At C the iron is shown removing the temper from a watch-spring so that it may be bent and punched. In Fig. 2 the electric iron is acting as a water-heater; D is the pan, E the position of the iron, and F the little metal stand upon which the iron is set upside down. Figure 3 shows the iron drying a freshly made leather-belt lap. At G and H are seen the lap ends of the splice. Figure 4 shows the electric iron soldering a large pan. The dark spots at the bottom are small rust holes which caused the tub to leak. By the use of soldering wire cut in short pieces and driven into these holes, the iron will melt it slowly and make a rivet which will plug the holes tight. fan a Trained Man in the AUTOMOBILE BUSINESS Learn in 6 to 8 Weeks Earn *150 to $400 a Month All the Year’Round [carn_in America’s foremost school. Over 2 million dollars invested. Four big buildings, vast equipment — Automobiles, Trucks, Tractors of all kinds, all latest motors, 4’s, 6’s, 8’s, 12’s, in operation for ‘‘trouble shooting.” Electric Starting and Ignition Systems of all types. Extra large Tire ne Acetylene Welding, Machine and Repair Shops. All students get personal and individual training under Master Instructors. Rahe School I train with tools—not books. The thousands of former Rahe You work on real Autos, Trucks, Students now in business for them- Tractors—all pee and sizes and selves always call for more Rahe latest models. My school is recog- § Trained Men than I can furnish them. nized as the greatest and best auto- These former Rahe Students are in motive training school. I trained business in all parts of the United thousands of soldiers as motor me- States arid engaged in all branches chanices for U. S. Government in60 of the Automotive Industry. They day periods. Opportunities are un- refer Rahe Trained Men for their limited. Authorities agree the coun- usiness. I will train you to be try needs 10 times more garages and successful in your own business just repair shops and men to run them. as I trained these. ‘ No Previous Experience Needed: 457 m2", 16 years can learn comers motor mechanics in my school by the Rahe Practical Method. Over 35,000 men of no previous experience have learned here and are now making pee money. No — educational requirements. No tools or ‘‘extras’’ to buy. In a few weeks you are all ready to accept a waiting posi- tion or to g° into business for yourself. Always more calls for Rahe ‘Trained Men than I can supply. Free Catalog. Write today for Free 68-page Catalog, showing ~ibewiiteined the thousands of opportunities now open. RY J. RAHE, °":**...S22ns5.ctu Me.

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a ee onan ine ae) hu RAR AES AIT tate oem A he em VA abn ea in. Sale gy - 2 NR NN et eS abn EMS ee NE MeN © CM F*-$3.00 Army Goods Bargains! You. Hurry! Order NOW—Direct from this Ad. We deliver prepaid. Money-Back Guarantee Protects penis pepaizes. wi Pee jing, ete ve size. seco a? are in splendid con- ne Small ri ~~ ys feat for h petee, Gebine, —_ a unting ng, touring, ete. ~~ K-233—Spiral sogemes, reclaimed, O. D. Wool, first class 7 condition. [Brice . delivered strong Olive Drab can- vas with harness to go over the shoulders. Used b boys in France, Fine ~— hunters, ara, toure me Ob¢ =. K-411—ArmyCoat Olive Drab Cotton. Re- claimed and laundered, Fine for work, outing, ete, Saves Sizes, 84 and up. Givelc size | ice delivered . Dept. K . detiverea. OD #_- K -137—Olive Drab Blank-} ets. Reclaimed by government methods, Practically like new. Genuine Wool. . touring, etc. K-911912—Arm y Price delivered Brecohes. ‘Thor Brand New Olive Drab Blank- 6.95 ets, bargain Fo pa ty A 4 ay Price delivered. unt- 99—Boy Scouts Shel- ter Tents. = Shelter or — tents used by Yanks hes rance. Just 4 ching. for nters, campers, hiking Watenpeeel. Complete with t Piss Hees. $3.95 K-231—Canvas in ~" ys nd-hand, K-228—Military Axe. Made of highly tempered steel, keen cutting edge, gen- uine hickory handle, painted Drab. Forauto trip, ae, camping, ay Olive Uz =. Quuseens master, Price delivered K-323—ArmyA Knitted Cap a ona ee bined. Pure Worsted. Kit, num, Tight. fitting cover. Combination —- an late, Just the thing and for etc Finest te: - mpl iy and you vty ‘ark. ne by all U. S. Aviators, Sea SOF For camping, . . ed large supply fro A7 K -229—Leather Protector’ for above axe to be attached to Scarf co nglish Olive Drab a 61.37 emyMess Madeof Alumi- oy Scouts, campers Clotkes Wi lably low Pare gains, ‘ar, Overalls, W _e everter ryday use land storie 1 = je atereet al Stroman: ! eralls, Work items of eve: CARNIE-GOUDIE MFG. CO. Kansas City, Mo. A Short Cut to the Circle’s Circumference OW often have you wished that you could get fairly accurately the circumference of a circle quickly without a lot of figuring? The following short cut is especially valuable to the sheet-metal worker and to others as well. Suppose we were laying out a sheet-metal duct of circular construction and had drawn a circle to denote the cross-section. Take a steel square or a large triangle —it doesn’t matter which; one will do as well as the other—and place the corner of the angle on the center of the circle as shown in the illustration. Then make a mark with a pencil where the sides of the angle cross the circle £ STEEL SQUARE \_— or TRIANGLE. Here is the shortest way to tell the circumference of a circle outline. These marks we will call A and B. Now draw a line, using a straight edge from A to B. This line, as we all know, is the cord of an arc. From the middle of this cord measure to the extreme outside of the circle line. This distance we will call C. We now have all the necessary data to work with. The formula is very simple: three times the diameter of the circle plus the distance C equals the circumference. If we take, for example, a 5-in. circle and have found by measurement that the distance C is a shade less than 34 in. Three times 5 plus 34 gives us 1534. Tocheck this up we find that by using the standard formula 7D, which is 3.1416 times the diameter, we get 15.71, so that by using the short method we have an error that is neg- ligible—FRANK W. HARTH. Electrocuting Four-Footed Chicken-Thieves OUNTING my flock of chickens every night for a week I found that fifty had utterly disappeared from the henyard in that time. This yard had a five-foot fence all around it, but I noticed that it was slightly bent down on the side away from the house. I concluded from the many feathers scattered about the yard that a four- footed thief was at work. A few months previous to losing the chickens I had installed a small electric-lighting plant in my home. This plant was operated by a water- wheel set in a stream about four 116 Popular Science Monthly Make $10 to $30 per Day at VULCANIZING with Anderson Steam Vulcanizers. Better tire vepeiee ing and retreading at one-tenth the usual cost. Big profits for thousands owners. We not only supply the Anderson Steam Vulcanizer and Ander- son Retreader, but we teach you how to use them, and how to build upa successful business in your town, with little capital. here are Anderson Schools of Vulcanizing in 33 states. There's range one near you. rite and we will tell you all about it. i The course requires five to He da ? and costs $35.00 2 buy an Anderson 1- canizer the course does not cost you a cent and in addition we pay $5.00 per day expense money because we sell the work you do while teaching you. Don’t miss this opportunity. Write today. ANDERSON STEAM VULCANIZER COMPANY 101 Williams Building Indianapolis, Ind., U. S. A. with write mrntesoto to 100 words x'minvee ts now arn carn $32 YO si Yo ss eee eWEEK. 10 lessons at home, in s e. No in. sara in i with oa work, Honey refunded if results are not sa tory. Tanase’ the NEW Way Totally new system based on Gymnastic Finger g, practicedaway free pcbine. First results. | Send postal for 82 page ing” abe 8 salary. salary. Writs NO eblcotee “ e eye a Never-Failing Exterminator No need to be troubled with rats and mice. *“*Rough On Rats’ never fails to clear the prem- ises of these pests when used according to direc- tions. It is not a ready- mixed exterminator; rats do not learn to avoid it because the food you mix it with can be changed as y- Ittempts old and Toune rats alike. At drug and general stores. g Rats and Mice’’—booklet—sent free. E. 8. WELLS, Chemist, Jersey City, N. J. AGENTS $6 a Day Should be easily made selling our Concentrated Non-Alco- holic Food Flavo Soaps, Perfumes and Toilet — times the strength of bo bottle extracts. Every home in city or country is a possible cus- Somes: . ae os new. Quick repeaters, Not’ sold in stores. oie” competes. 100 cent. profit to agents, Little or no capital —_ qecent spon gd lo FREE Cul AMERICAN PRODUCTS CO, 2821 American Bldg. Cincinnati, @, DEAFNESS IS MISERY I know because I-was Deaf and had Head Noises for over 30 years. _ My invisible Antiseptic Ear Drums restored my hearing and stopped Head Noiges, and will do it for you. ey are Tiny Megaphones. ‘annot be seen when worn. Effective when Deafness is caused by Catarrh or af pusoreead, Partially or Wholly Destroyed Natural — Easy to Sst i is easy to take out. Are “Unsee: Comforts expensive. Write for Booklet and my pall statement of how I recovered my hearing. ' A. O. LEONARD Suite 301, 70 Sth Avenue - « New York City Mito hoe TELEPHONES AND HOW TO MAKE - An elemental book on the ‘mange wm con- pone: A and use of an arc wee of wireless telephony. Illustrated. Price. stpaid, 25 cents POPULAR SCIENCE MONTHLY 252 West 39th Street New York I ( I f mm

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, soe ee © November. 1520 hundred yards from my home, the plant generating about thirty thou- sand volts. Having some copper wire left over I ran two wires around the top of the

The foxes trying to jump the wire fence were thrown against the live wires put there for the purpose and electrocuted fence, of course making the necessary connection to send the electric current through them. Just before retiring that night I turned on the full current from my power plant. When I awoke the next morning, there were three foxes stretched out, dead, beneath the place where the fence was bent over. Since that time my chickens have all »een accounted for.—L. W. FLETCHER. Enlarging the Bore of a Reamer MACHINIST recently showed me a trick with a reamer that may be useful to others. Hedesired toream out a hole in steel to a certain diameter, but the reamer nearest the size desired fell short a small fraction of an inch. To make this reamer sufficiently over- size to meet the situation, he resorted to the following expedient: He took several pieces of small round brass wire or rod and placed them along the flutes of the reamer on one side. Then he | drilled a du- | plicate of the ) hole he in- | tended to ream and ex- | perimented TD SUSU TUTTE UU OE | | Sah with the ex- | 3 panded ream- | er until, by | : removing or adding pieces of rod, he filled out the flutes just enough to force the reamer over to one side suffi- ciently to ream out a little more metal. The rods were of soft metal and did not affect the roundness of the hole. To force the reamer to one side the rods must be sufficiently large, of course, to project beyond the sides of the cutters of the reamer. HUT

Brass wires placed in the reamer will enable it to bore a larger hole

1000 Lo as THAT HOLDS AGE: $7-22 $800 $900 & 310-00 SHOES FOR MEN AND WOMEN YOU GAN SAVE MONEY BY WEARING W. L. DOUGLAS SHOES TT he bestknown

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and $5.50 © direct from the factory to you at Douglas stores, only one profit, which guarantees to you the best shoes that can be produced, at the lowest possible <oat: W. L. Douglas name and the retail price are stamped on the bottom of all shoes before they leave the factory, which is your protection against unreason- able profits. W. L. Douglas $9.00 and $10.00 shoes are absolutely the best shoe values for the money in this country. ey are made of the best and finest leathers that money can buy. They combine quality, style, workmanship and wearing qualities equal to other makes selling at higher prices. They are the leaders in the fashion centers of America. The stamped price is W. L. Douglas personal guarantee that the shoes are always worth the price paid for them. The prices are the same everywhere; they cost no more in San Francisco than they do in New York. W. L. Douglas shoes are made by the highest paid, skilled shoemakers, under the direction and supervision of experi- enced men, all working with an honest determination to make the best shoes for the price that money can buy. W. L. Douglas shoes are for sale by over 9000 shoe dealers besides ourown stores. If your local dealer cannot supply you, take no other make. Order direct from factory. Send for booklet telling how toorder shoes by mail, postage free. CAUTION.— Insist upon having W.L.Doug- e name and price is — President W.L.Douglas Shoe Co., 124 Spark Street, Brockton, Mass. UUUUUUUUULVNUUUNUUOALGULULULULAUGLUUAUUUL UHL

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‘117

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10 Cents a Day Pays for This Symphonola Page oii yacosds, em honola, Victor, Columbia, Edison = Little Wonder, Emerson. Take over a year to pay ter 30 days’ trial. Compare its tone for clearness, volume, with — costly sretremencs, Return at our expense if it make good k toda iar the Beautifully tit Hilseteatnd maphonele Book FREE sy honola Recerd ¢ fore sold on easy payments. 3ymphon ecords Get our i Match the latest song, dance bo is. Pl wekwe sounding, full toned larkiz Ca, Desk SPSM-1120 Buffalo, N. Y.

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How to Make Wireless Instruments A little book that fully describes the construction of spark wireless instruments and apparatus. Just the thing for the amateur. Illustrated. Price, postpaid, 25c. Book Dept., Popular Science Monthly 225 West 39th St., New York City

Learn in Spare Time to be a CIVIL ENGINEER Earn $1500 to $5000 Yearly Here’s your big chance to be- come a full — Civil Engineer! With this set of books you can fit " yourself to make big money, in the greatest outdoor profession y onearth! Offer fully explained in «@ = coupon. Good only within bound- oe Sve- CE d\ aries of the U. S. and Canada. <r! Great Books Shipped FREE 7Sca Week 5 yout stem ate Nine big leather-bound volumes; 3900 pages, 5%¢x8 inches; 3000 plates, maps, diagrams, etc. Written by world’s greatest civil engineers. Books tell you ALL ABOUT surveying; highway con- struction; railway engineering; earth work; speci- fications; estimating contracts; bridge engineering ; masonry; _ reinforced concrete; water supply; sewers and drains; water power equipment; irri- tion engineering—etc., etc. Written in simple anguage—every point made plain. Consulting Service Free A $12 Consulting Membership solves your difficult problems fora whole year. FREEwith the set of books. SEND NO MONEY—JUST THE COUPON!

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118

Popular Science Monthly Concrete Supports for Work Under the Car HOUSANDS of car-owners take their cars to the garage and pay for little jobs that they themselves could do at home. But the thought of sliding under a chassis with a twelve- inch clearance and attempting to make satisfactory repairs keeps them from trying it. Some few thoughtful ones provide their garage with a pit whereby this work can be done either in a sitting posture or on bended knee and it is seldom that cars which come to rest over a garage pit every night lack for the simpler attentions due them. And yet another method: The illus- tration shows that used by one car- owner who itched for a wrench and screwdriver every time he heard a knock. Just back of the garage he fo) concrete

~ This concrete support set in back of the garage enables the owner to work on his car without lying on his back dug two trenches about 4 ft. longer than the wheelbase of the machine, 8 in. wide and 18 in. deep. Forms of wood were arranged above the ground at a 2 ft. height and both filled with concrete. The forms were filled to the top at one end, but tapered off at the other as shown, care being taken to see that the level portions were 1 ft. or more longer than the wheelbase of the car. The concrete was poured rather thin and after thoroughly tamping, the top of each wall was scooped out to a depth of 3 or 4 in. and slightly wider than the diameter of the tires on the wheels. As seen in the drawing, the notches in both walls terminate abruptly oppo- site the sloping approach, and gradu- ally diminish in depth at the other end. Thus it is easy when driving the car on to the supports to stop at the desired place—namely, with the front wheels against the end of the - depressions. If desired, the notches may be made slightly deeper at the points on which the rear wheels will rest, to prevent any chance of the car backing off, or the walls may be made to slope slightly toward the front end. With such a support always at hand, it is a simple matter to run the car up on to it for a hasty repair at any time, and the light and working facilities will be much better than they could be in a pit in the garage. The merely nominal outlay in money will be soon made up in repair bills saved, and will be a means of encouraging the boys to keep the car in condition. Ten or fifteen minutes once a month should be sufficient to go over the nuts which are apt to work loose. Four or five dollars will buy the cement and sand for this support for your car.—DALE R. VAN Horn. a ee ee ee ee ee ee ee

a "085 85 ND RH DD a

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November, 1920 A Cutter for Making Large Holes UTTING large holes in sheet metal is sometimes quite a prob- lem when the metal is too heavy to work with shears, or the hole is not large enough. A highly satisfactory tool can be made for the purpose in the fol- lowing way: Take a piece of brass or steel tubing of a diameter about 1/16 in. smaller than the size of the hole. Plug one end with hard wood, carefully square up the plugged end, both wood and tube, accurately mark the center, and insert a steel pin about 14 or 3/16 in. in diameter, letting it project about Vo in. Have the pin tight in the wood and well supported. Take a hacksaw blade with fine teeth and cut it to such a length that it will exactly encircle the tube, the ends coming close together. Secure the blade to the plugged end of the tube with small machine screws -tapped into the tube, allowing a little more than half the width of the blade to project below the plugged end. Use at least five serews—one in each end of the piece of hacksaw blade and the other three at equidistant points; if the tool is large, use more screws. An important point is that it will be found TUBE necessary to draw part of the temper of the blade be- fore it can be bent and drilled, but the softening process should not be carried any further than is neces- sary. Heat the blade ona piece of flat iron, or in an iron pipe, held over a Bunsen burner or other gas flame so the heating will be even. If the blade is too soft, the teeth will not last long; while if it is made too hard, it cannot be drilled and will break when an attempt is made to bend it. It will be necessary to do a lit- tle experimenting and to spoil a few blades before just the right result is obtained. To use the tool, drill a hole in the sheet metal for the steel pin, making the hole so that the pin will fit without lost motion; put the tool in an ordinary brace, insert the pin in the hole, and turn. The hole will be smooth, clean, and true. Not much pressure is required. A good way to attach the cutter to the brace is to plug the upper end of the tube in the same way as the lower end and insert a piece of square steel that will fit the chuck of the brace. Drill aholesomewhat smaller in diameter than the diagonal of the square steel and drive steel into place. ‘| HACKSAW |} BLADE t — STEEL PIN A hacksaw made into a circle will cut any size hole Get Double Use From Single Electric Sockets The full convenience of modern Elec- trical Appliances is not realized until single electric light sockets are given double use with the Turns every single socket into two with a twist of the wrist. Millions in use. Gives you light and heat or light and power at the same time. “Every Wired Home Ni eeds Three or More’’ AT YOUR DEALER’S Have all your Electrical Conven- iences equipped with Benjamin 903 Swivel Attachment Plug. Screws into socket without twisting the cord. Benjamin No. 2452 Shade Made only by Holders enable you to use any BENJAMIN ELECTRIC MFG.CO, shade with your Two-Way Plugs. Chicago New York San Francisco Expert electrical engineers are being paid fabulous salaries. Thousands needed to- day. Wegive you personal and thorough training — practical, technical, courses. three months totwo years, under expert engineers in electricity, steam, gas, auto, armature winding, drafting, etc. Extensive laboratory and shop equipment. Nota trade school. Enroll anytime. Do not judge us by size of ad but write for free illustrated catalogue, FINDLAY ENGINEERING COLLEGE a Srentens of its kind 1001 Indiana Ave Kansas City, Mo. Violin, Hawatian Guitar, Ukul Guitar, Mandolin, Cornet, Tenor Banjo or Banjo teaching music by mail. To fret Violin, Mandolin, lutely free. Very small charge for lessons only. We guarantee suc- cess or no Complete outfit free, Write now. No obligation, SLINGERLAND SCHOOL OF MUSIC, Inc., Dept. 27, CHICAGO, ILL. MUO aaa MakeYour Bike a > Motorcycle ay The kw cost Shaw Attach- ms: ment fits ond bicycle. ly Dat or on. No special t tools or nqwiedge pec. Shaw otorbleyele, a saad power bike at big saving., SHAW MANUFACTURING CO. Dept. 4611 . Galesburg, Kansa2e [Axrt Corners | -No Paste NEeoep to mount all kodak albums 1Q¢is07 Engel Y Why Poy Foil] | MAU ETRY CM RMI | aTeeneurye raved ever i000, 00 00 [> At Home _ h de mutta ta the mplete a t American a rns Re teachers. n eacher ail creat Am impliity and co and coach oice ane i es Pub! Mosic, Violin, Gorse Mandolin Organ—and we will send our ea ae CATAUO a *.-- on avproval. Amazing sa customers’ letters, Send for Latest List Diamond Loans Free and without obligation —pendestel lists of amazing radically different rom catalogs. ou haveev ity f free to test and verif: We before you buy. Write today. DeRoy & Sons,4728 DeRoy Bidg. Opposite P. O. Pittsburgh, Pa. UNIVERSITY EXTENSION CONSERVATORY 1 Siegel-Myers Bldg. Chicago, Illinois "i AN ATEN A INOS ADEE AE: RS r

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perenne <aibcol oo ah mannan 2 BS 8 eR Se aaah ad Malet RN Seta Ee BTL SHINE IME COURSE IN TWO YEARS YOU ARE BADLY 7 inet —_ BANDICAPPED =o 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 positions demand High School train- ing. You can’t hope to succeed in the face of this handicap. But you can remove it. School help you. Let the American FIT YOURSELF FOR A BIG FUTURE 7's Corse; spapaned by some of America’s

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essors, will broaden your mind, and. make you coon, alert and capable. It is complete, simplifi and up-to-date. It covers all sub- jects given in a resident school and meets all requi of a High School training. From the first lesson to the last you are carefull and coached. y examined USE SPARE TIME ONLY Most people idle away fifty hours a week. Proba! youdo. Use only one-fifth of your wasted hours for study and you can remove your present handicap within two . £0U nowledge will enjoy the lessons and the kr por err eee will well repay the time spent in Ye YOU RUN NO So that you may see for yourself how thorough and beipam complete our training is, we invite you to take ten lessons in the high hool Course—or any course of specialized training in the coupon below—before decid- ing whether you wish to continue. If you are not then satisfi ed, we will refund your money in full: We absolutely guarantee Satisfaction, On that basis you owe it to yourself to make the test. Check and mail the coupon NOW for full and Free Bulletin. OF Dept. H 875

Chicago, Illinois Explain how I can qualify for the position checked. . -High-School Graduate . -Electrical Engineer .-Elec.Light& Power Supt. .-Hydroelectric Engineer .. Telephone Engineer .». Telegraph Engineer N Address . Wireless Operator . Architect . -Building Contractor . -Civil Engineer .- Structural Engineer - -Mechanical Engineer -Shop Superintendent -. Steam Engineer . -Draftsman and Designer -Photoplay Writer .-Employment Manager Q@Me ...--2-++ ce-es cere ..-Lawyer ..-Business Manager .. Certified Pub. Accountant ..-Accountant and Auditor .-- Bookkeeper -. Stenographer . Fire Insurance Expert . Sanitary Engineer . »--Master Plumber ..-Heating & Vent. Engineer . Automobile Engineer .- Automobile Repairman ..-Airplane Mechanic »--General Education Course .--Common School Branches ..-Foreman’s TrainingCourse eee ee eee eee ee ee

How to Make Your Own Cabinet Clamps CABINET-MAKER’S | clamp A suitable for the amateur’s work- bench can be made of a section of channel iron and a discarded bolt as follows: Cut out a section of heavy channel iron about 1 in. wide. The width of the iron between sides should be enough to furnish jaws of sufficient opening for ordinary work. Select a suitable steel bolt and drill and tap a hole near the top of

CHANNEL IRON

Channel iron and an old bolt will make — an excellent cabinet clamp one of the-jaws of the clamp into which the bolt can be threaded. A second hole through the bolt-head should be drilled to take a short piece of rod for a turning handle. File the end of the bolt smooth and round and about half its original diameter. The bolt should then be set through a hole in a nut. One half of the nut is hollowed out and the end of the bolt then can be riveted over so the nut will revolve easily but will not allow the end of the bolt to pro- ject beyond it. Thus the bolt, when turned down on any article, will not mar it. Such a clamp is cheap, simple to make, and will do the work required of it'as well as the more expensive kind. To Check Up the Alinement of a Connecting-Rod “PART of an old discarded crank- shaft used in conjunction with an old face-plate and square, is a reliable means of checking up the connecting- rod alinement of a motor vehicle. . The crankshaft must be cut just forward of the connecting-rod bearing, and the fly- wheel flange used as a base to bolt the dummy crank thus formed to the face- plate. The as- sembly to be tested is at- tached to the

When your engine knocks, test the alinement of the connecting-rods and elim- inate the trouble bearing, as shown in the illustration,’ and a metal square is used to deter- mine whether or not the top of the engine piston is parallel to the crank- shaft bearing. It will be seen that the 120

Popular Science Monthly .World’sBest PAZ oh =A ae — " _ z “Reo” Cluster Metal Shingles, V-Crimp, Corru- ited Sanding Soom. Painted or Galvanized Roof- ngs, Sidings, allboard, Paints, etc., direct to you at Rock-Bottom Factory Prices. Positively greatest offer ever made. Edwards “Reo” Metal Shingles cost less; outlast three ordinary roofs. No painti orrepairs. Guaran rot, fire, rust, lightning proo 4 Free Roofing Book Get our wonderfully low prices and free samples. We sell direct to you and save you all in-between dealer’s Samples & Roafine Rook on Ready-Made Proo: aoe i Garage Book, showing styles. Fa. COo., Ciacinaati, 0. ARDS M 48-1198, Pike St.,

You can easily learn Modern Ballroom Danc- ing now in your own no matter where you live—by the famous Peak System of Mail Instruction Fox-Trot, One-Step, Waltz, Two- Step and latest Ballroom dances taught. Courses constantly revised to include the newest dance ideas. We Guarantee the Peak System to teach you to be an easy, graceful and accomplished dancer. Equally successful with beginners and with dancers seeking to improve, and learnthe latest society steps. New Diagram Method: The result of forty years’ practical experience. Easily and quickly learned. Thou- sands taught successfully. I can teach you. Send Today for FREE Information: Write at once for surprisingly low offer. William Chandler Peak, M. B., President The Peak School of Dancing, Inc. Established 1880 Room 115 821 Crescent Place Chicago

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pre Big Money. i cars County Agents Onty Honey hack quar: four and De Luxe six. Don’t wait. Write today! BUSH MOTOR CO., Chicago, iilinois, Dept.p111 Bush Temple & ARMATURE AND MAGNET WINDING By Horstman & Tousley A necessary book for electricians. Full facts and dia- grams, $1.75 tpaid. POPULAR SCIENCE MONTHLY, 225 W. 39th St, New York “BOWLEGSand KNOCK-KNEES” UNSIGHTLY 4) SEND FOR BOOKLET SHOWING PHOTOS { y, OF MEN WITH AND WITHOUT LY

course is rite for Free Book 332.2 nis eee HOOSIER INSTITUTE, S.S.Dept. 1788 Ft. Wayne, Indiana

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November, 1920 - dummy crank must be bolted to the ace-plate absolutely true, otherwise the accuracy of the test will be destroyed. When the engine continually knocks or scores the cylinder walls, while all other parts are apparently in normal adjustment, it is wise to check up the connecting-rod alinement as de- scribed.— RONALD L. PRINDLE. Some Ways of Arranging Machine Belting HE amateur machinist is not al- ways aware that belting can be arranged to drive a wheel or counter- shaft in any other way than by the direct method employed in all or- dinary power transmission. A man having his own little power plant in the basement, attic, or in any small, confined quarters, can, by clever ma- nipulation of belting, greatly increase DRIVE PULLEY DRIVEN PULLEY, DRIVE PULLEY’ S PULLEY DRIVEN ” PULLEY FIG.4. FIG.5. FIG.6. Some suggestions for belt-drives that will prove invaluable to any one with limited shop space the machine capacity of his limited space. The illustrations show how a few of these combinations can be made, and their advantages are obvious. Figure 1 illustrates how two belts can be run from the same pulley to drive two shafts. In this case the middle shaft must be situated in line with the other two. While this is a favorite method with some machinists, it is little enough known among ama- teurs. . Figure 2 shows a flat belt trans- mitting. power between two parallel shafts over guide pulleys, the shafts not being in the same plane. Such shafts may be located in any direction from each other with the arrangement of guide pulleys as shown. Figure 3 shows a method of trans- mitting power by a flat belt from one shaft to another in a case where the shafts are too near together for direct driving. In this example the belt is also directed by guide pulleys. - Figure 4 illustrates another way of LORSHEIMS are “long run” shoes—cost you a little more than some in the begin- ning, but much less in the end. That’s the theory Florsheim has always followed. It works out better than ever in these days of high prices and uncertain values. You get most for your money in The Florsheim Shoe. Consider the wear not the price per pair. Look for the name—The Florsheim Shoe. Write for booklet “Styles of the Times.” in 3 THE FLORSHEIM BA: SHOE COMPANY a4 Manufacturers Chicago The Kenwood— Style M-61 Cartoonists Big Money Make OH MIN! EvERY time Sid Smith makes a stroke of his pen, millions of people laugh, and every laugh means money for the man who creates it. Andy and Min earn big money for him every day. Men who can make people laugh are highly paid for doing so. By capitalizing their humorous ideas and their ability to draw, cartoonists like Fox, Briggs, King, and Smith make $10,000 to $100,000 a year. YOU may have ideas that are equally good. Let Federal training give you the skill to put them on paper. Send For This Book If you really want to learn to draw, send for ‘‘A Road to Bigger Things.” It describes the Federal Master Course and shows how it will develop your originality while teaching you the technical details of cartooning. Through the Federal Course you get the composite experience of more than forty of the greatest cartoonists and artists for your personal use. Send six cents today for your copy of this book. Be sure to state your age and present occupation. Federal School of Applied Cartooning 01028 Warner Building, Minneapolis, Minn. 121 SS ee a a

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a eT ‘| 4 y : 4 ef ennigetpianeabereiielaneapitih: signa aR Seep ae ate renee tae FB atnnent orenee nent ence 5 i i bai The biggest business in the world The greatest business in the world today is the big business of transpor- tation — moving goods and passengers and mails by trains and_ ships. It isa business that offers wonder- ful opportunities to young men. With an Ives Toy railway system, you can learn all about railroading while you are having great fun. You lay the tracks, install the switches, signals, bridges, tunnels and stations. You are the builder, general superintendent, engineer and president of your railroad, all in one, learning all about the business. [ves Toys Make Happy-B Oys Ives trains are just like the real trains. They have powerful mechanical or electric locomotives, while the cars are made and painted just like those of the big railroads. There are beautiful coach, buffet and bag- gage cars, tank cars, cattle cars and red cabooses. Ives Boats are made of steel, with strong, long running motors and real screw pro- pellers. They will run a long time in water under their own power. There are ocean limers, tugs, steam yachts, launches, U. S. Marine ships, scout patrols, torpedo boat destroyers and diving submarines. Send for these books Wiite today for our finely illus- trated boat book, ‘‘Ships and Ship- ping,”’ full of nautical information, rules of the sea, etc., and our fine folder on trains. Both sent for 10c in stamps to pay for postage and packing. The Ives Mfg. Corporation 191 Holland Ave., - - BRIDGEPORT, CONN. Ze q driving two shafts by belts from one drive pulley. In this method the drive is accomplished in the same manner as with an ordinary cross belt; that is, a twist is madein one belt where it crosses the other, thus eliminating interference. Figure 5 shows how one belt can be used to transmit power from a main shaft to two other shafts running at right angles to it. However, these must be all in the same plane. Figure 6 shows the manner in which two pulleys should be belted up which are at right angles to each other, but not in the same plane. Certain con- ditions are necessary to make this connection right. In the first place, the distance between the near faces of the pulleys should not be less than four times the width of the belt. The pulleys should be so arranged that a line drawn from the center of the face of one pulley will be tangent to the face of the other. This idea is illus- trated in the sketch. The deflection or twist must come from the pulley with the wider face. These arrangements are invaluable to the man with limited shop space and who wishes to make the most of his source of power. Belts must, of course, be kept in good condition and well cared for todo the greatest amount of work.—L. B. ROBBINS. A New Lubrication Idea for a Milling Cutter T isa well known fact that if a mill- ing cutter is well lubricated while it is cutting, it will perform quicker and better work. Acting on that as- Instead of a thin stream of lubricant, this device throws a wide stream on the milling cutter sumption, here is what the writer did: In place of the ordinary single pipe which fed the lubricant to the cutter, a long pipe was made with a series of holes in it similar to those in the illus- tration. bent to the shape shown and the re- sult was a good wide stream of lubri- cant.—J. W. Moore. 12° =e Popular Science Monthly aa What the Spin Means It means that the wheels on your Auto-Wheel will run faster and smoother. It means a sturdy coaster that will stand hard knocks. Roller-Bearings overcome friction. Get an Auto-Wheel and you'll elways have a good wagon. , TWO MODELS The Auto-Wheel Convertible Roedster and the Auto -Wheel Coaster. The roadster is a com- bination wagon. Turn the sides out to change it from a roadster toa coaster. The Auto-Whee! is the old standard coaster wagon. ut con' 4) Auto-Wheel Club. Send for a FREE six months’ subscription, alsoa neat Auto-Wheel Coaster Dime Bank. Send-us names of . telling which ones sell the coaster wagon with the name ‘Auto -Wheel” on the sides. The Ss Coaster Co.knc. Sled Compang The 157 Schenck Street, N. TONAWANDA, N.Y. In Canada: Preston, Ont. Export Office: 865 W. 28rd Street, New York City. , Auto Wheel Shoot Without Noise Avoid disturbance, also flinching. Enjoy quiet shooting, anywhere, anytime. Use a MAXIM SILENCER Price, .22 cal. $7.00. Send 6c in stamps for catalog and book- let of astonishing experiences of Silencer users. The Maxim Silence: Co. 91 Homestead Ave. Hartford, Conn. Build This Car This nifty little car driven by ne motor, can built . by any boy. Parts are furnished Next, a piece of tin was SY WHY DONT YOu w H RITE THE WORDS FOR A SonG WE'LL HELP YOU ALONG oe ig mE ny rg Bre. LENOX CO. 271 W 25th Se. NY. —————————— — Every Bicycle a Motor Cycle By using a STEFFEY ATTACHMENT Fits any ordinary bicycle, truss. diamond or double- bar frame. Ea ZA toattach. Thoroughly PRACTI- SJ CAL and SUCCESSFUL. Send ‘: stamp for circulars. STEFFEY MANUFACTURING CO. Department 8, 5025 Brown Street, Philadelphia, Pa. Popular Science Monthly

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November, 1920 November, 1920 Supplying Moisture for the Automobile Engine LMOST every man who owns or has run an automobile has noticed that his engine actually runs better in the very early morning or late at night, just after the dew has fallen. This is due to the amount of moisture in the air. Why contend with the frequent skipping of the engine and the loss of co! TURNED OVER AND SOLDERED 7 KON FRORY OF DASH f || WATER LEVEL FLEXIBLE COPPER Tee |_— BRACKET INTAKE MANIFOLO Iron straps fasten the humidifier to the ~ dash beneath the hood. A copper pipe runs from it to the carburetor power due to the hot dry air of a summer day, when with a few hours’ time and a little expense you can manufacture an apparatus which will give you the moist cold air that gives life to your engine? A Mason preserving-jar of the quart size should be mounted on the back of the dash underneath the hood of the engine. This may be done by the use of an oil-can holder for a shelf and a couple of band iron straps to hold the glass jarin place. In the metal top, about 1 in. apart, drill two holes, one with a 14-in. drill and one with a 3-in. drill. Solder into the %-in. hole a small nipple having on its end a small union joint such as is used with flexible copper tubing. A piece of %-in. brass or iron pipe ¥4 in. shorter than the height of the jar, should be threaded on one end for about 34 in. On this thread place one nut and one washer and thread through the cover of the jar, placing another washer and rut on the outside, tightening the two nuts until the cover is held rigid, and when mounted on the jar allows the pipe to extend down- ward to within 4 in. from the bottom, A Yéin. copper tubing extends from the nipple soldered in the jar-top through the dashboard to a stopcock, and continues on back through the dash, and is tapped into the intake | manifold just above the carburetor. {- “Pains enemy” IT say it is! VV HEN you want quick com- forting relief from any “ex- ternal” pain, use Sloan’s Liniment. It does the job without skin staining, rubbing, bandaging. Use freely for rheumatism, neuralgia, aches and pains, sprains and strains, backache, sore muscles. It breaks up colds, too. i | 8 ~|9 and Wri Talking LUCKY 13 PHONOGRAPH COMPANY Export Dept. 46G, E. 12th Street, N.¥., U.S. A. or our 5t-peg kind in America, il Machines graphic Parts. leartone Phonographs $4.00 to $200.00 Retail Our Sundry Dept. offers Needles 39c pet . Motors $1.35 to $14.75 each. Tone- and a roducers $1.30 to $6.75 per set. Main springs 90¢ Records, Needles, Sapphire Points oe at reasonable pric 3. catalogue, the only one of its : ting 33 different styles of over 500 different Phono- 4 New am. 14-200 pp. Wireless and 100 pp. Electrical Catalog Wireless catalog mailed for 12¢ and electrical catalog for 6c. You may mm deduct this amount on first $1.00 purchase. Catalog not sent other- wise. Any wireless amateur will tell you it isthe one catalog to have. THE WILLIAM.B. DUCK COMPANY 212-214 Superior St. TOLEDO, OHIO Send for a Complete Catalogue of MASONIC BOOKS Jewelry and Goods REDDING & CO. Publishers and Manutacturers 200 Fifth Avenue Dept.S New York 3] TEACH YOURSELF 33,2" a would. Adopted by U. S. G Automatic unlimited Morse or Continental messa: ov’t. an a ** THERE'S MONEY INIT - SAR=LEARN TELEGRAPH Y=30% MORSE AND WIRELESS—-—-— A 2 = eee © wee wo eee ee ee, ES om ay oe Ge oe vanomaitier THE OMNIGRAPH. sends , at teadi: @raph Schools. 4 styles. Catalog free. ‘ OMNIGRAPH MFG. CO., Dept. H., 26 Cortlandt St., New York. any speed, just as an ervert ng Universities, Colleges and Tele-

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j ne ts Pe 2. crea ee PRE RES OES" one * Reorenanamescnmnienies SE II SO MR Sra MM ame PY ree pertenasea nts ie ee ee Ba eR HN ag a HANES MAD ‘ as The Man Who Positively Knows Wins It’s the fellow who “knows” that gets ahead. The man who knows “how” and “‘why” gets the worth-while jobs—and the big salaries that go with them. Let the master minds of industry show you the short cut to real success. The very methods and ideas that made eighty men the diggest men in their fields will be sent to you for a week’s free trial. Accountancy and Business Management This great Business Library is a complete business training for the beginner and a handy reference work for the executive. It covers every line of business—shows new and better ways of doing things—explains methods by which other men have made money and best of all shows how

000 = you can make more money 10, “ Money and rise to the position you Making Business would like to have. The seven Facts at big volumes bound in genuine American Morocco contain 2700 pages and hundreds of valuable charts, diagrams and illustrations. Entire Library Seat to You for One Wee Free Examination Take a week to decide right in your own home or office whether or not the books will do for you what they have done for thousan of other men. You don’t have Your Finger Tips meome Tax Procedure, Advertising, Selling, Collections. Credits, Charting, chasing. Cost Analysis, ance, Inventories, Brok- erage, Banking, C. P. A. uirements, Business Forms, Retail Store Ac- counting. Insurance, to send us one cent for this Real te, Cost Keep- | privilege. Just fill out and ing, yo Meosgement, mail the coupon. The whole Mail r, Labor Con- library will come to you at trol, ion, Busi- once by express collect. After ag = gg Of- | @ week’s examination you fice uipment, etc can either return the books Over 25,000 sets of pre- | at our expense or send us rope siuemeasics | Eo Seperate @ ~ just off t each month until the special price of $29.80 is paid. Mail _ coupon now = get 3 sulting “mee ip in Society free. °

American Technical Society Dept. B-208 Chicago U.S.A. B-208Chicage, U.S. A. nd me set of Accountancy and Business oe a ven volumes for FREE Soaiation, shippin lect. I will examine the books ghly and i it satisfied will send $2.80 within 7 and $8 each month until | have paid the s special p price of $29.80. If I decide not to keep =e 1 wi them at your expense with-

“'"(Piease fill out ail lines)

| was intended to burn them.

The jar is then filled to about three quarters of its height with water, by opening the stopcock so the air may escape, and pouring the water down the tube in the ton. When the engine is running, open the stopcock on the dash, which is within reach of the operator, and the

This shows the complete device as it appears when mounted. engine will suck the air from the top of the water in the jar, this tending to cause a vacuum, and air will con- sequently enter the pipe and be de- livered at the bottom of the water. As the air bubbles up through the water it is not only cooled but is saturated with moisture. This moist air passes into the intake manifold and gives the same result as if the car were being driven at night along the side of a river. A bit of shellac applied with a tiny brush will help to make the joints airtight. As the water evaporates, the jar may be again refilled by pouring water down the air inlet tube. No water will enter, however, unless the stopcock on the dash is open to allow the en- closed air to escape. Using Stumpwood for Lime-Burning IREWOOD is becoming scarce and expensive. This has made the burning of lime more costly than in former years. It requires about 30 cords of wood to fire a kiln containing about 1500 bushels of lime. Owing to the increased value of the wood, we see very few of the old lime- kilns in operation nowadays. Coal has been tried as a fuel for lime-kilns, but the trouble with that is that it does not burn the kiln out clean. It leaves a great deal of un- burned stone, which not only causes a | loss, but makes a great deal of trouble for the operator. One of the most prosperous and progressive farmers of Virginia hit upon the idea of using stumpwood for lime-burning. He had been clearing a lot of stumpland and the stumps had been hauled to a vacant lot, where it Before this action was taken, however, the idea of using the stumpwood to fire . the lime-kilns occurred to him. His own farm needed: liming badly, and hé 124 Popular Science Monthly Diite am GclttaD Clee, Gifts Now afew cents a d ay JUST sendyourname and address for our 128 an Christmas book of argains in diamonds, watches and jewelry. Millions of dollars worth of jewelry from which to choose your Xmas gifts. Your selection sent on your —— Rey 4 without a If you don t ‘think it L the biggest bargain ave ever seen, sen “it | ck at our expense. If you keep it you can pay at the rate of only a few cents a day. 8% Yearly Dividends Youareguaranteedan&% early increase in value on all exchanges. Also 5 per cent bonus privilege. Write Today for Xmas Catalog Send your name and ad- now. No obligation. re Explains ‘all ©, ed ponoes f is grea el Uargains s now ad

The most remarkable values ever offered. A postal brings you a large assortment of cloth samples, wholesale prices direct from the manufacturer, style book and measuring charts. No matter where you live or —— where you have been buying = your clothes, and even if you Manenit do not need a new suit now, in- HMMA vestigate at once the wonderful : savings you can make by deal- = ing direct with this large manu- ————= facturer. Long wear, fast color, perfect fit, and satisfaction guaranteed. Write today. Address your card or let- ter like this: Lincoln Woolen Mills Company, Department 487, 208-214 South Green Streeet, Chicago, Illinois. $2000 to $5000 now being mode b oe 2 for -. famous Linco!

good men by wearing and taking ie-to-measure clothes. No experi- teach you — furnish free equipment. Write today! “DON'T SHOUT” “T hear you. Ican hear now as wellasanybody. ‘How?’ With THE MORLEY PHONE. I'vea pairin my ears now, but they are invisible. I would not know I had them in, myself, only that I hear all right.”

is to the ears what are to the eyes. —. ————. rmiess. Anyone can oo it. Over one hundred thousand sold. Write for booklet and testimonials. THE MORLEY CO., Dept. 797. 26 South 15th Street. Philadelphia, Keep Young Thru Pandiculation

You feel the need of exercise. You haven’t time. 15 min- utes use of Pandiculator equals 2 hours in gymnasium. Seg you pone F p, and vigor. The lazy man’s gym. Dp The Pandiculator Co.. 343 Advance Bldg. Cleveland, O. ee ee You CanSave $50.00 $8.46 Sy and up Parcels Pest Paid

<< Dm fod tot 6G

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November, 1920 had plenty of limestone available from which to make it. However, he hes- itated about paying the price now charged for cordwood with which he might burn the limestone himself. He was inclined to think that he could buy the lime cheaper than the wood; that is, counting what it would cost him for labor to operate his kilns. The pile of dry stumpwood solved his problem. The stumps had been nicely split up by the dynamite which had been used in blasting them out and made ideal firewood for the lime- kilns. He estimates that the use of the stumpwood saved him about $45.00, and as much more would have been expended in hauling the cordwood. This man figures that in using the stumpwood to feed his kilns, he really got his land cleared and limed for less than nothing, because the value of the lime produced more than equaled what the clearing had cost him. It is common practice for farmers to pile their stumpwood and burn it as soon as it is dry enough to burn after blasting. In view of the scarci- ty of wood, this is poor economy. Down here in our section of Virginia we are using stumps for firewood in our open grates and sheet-iron heaters. In sections where limestone exists and where lime is needed for the farms, it is decidedly poor economy to burn the stumpwood in the field, for it is most valuable for burning the lime.—CHARLES F.. H1GGs. Reference Tables Passed Along by a Trolley-Line HIS idea, which illustrates how one drafting-room eliminates waste of time, is so adaptable to other lines as to merit attention. In order to speed up the work of passing various reference tables from one draftsman to another, a trolley- wire was erected as shown in the illus- tration. This wire ran above the row of drafting-tables and a board attached to two trolley wheels which ran upon

Make a trolley-line for your office and send the work in a carrier the wire. Pasted on the board were the reference tables. A draftsman requiring the tables would merely ask for the board and the man who had it at his desk would give it a-push, and away it would go down the wire to the required desk. A simple idea yet a real time-saver and one which is adaptable to almost any office work.

LEARN DRAFTING are paid. No prev professional draftsm At Home in Your Spare Time Get into this constructive branch of industry where big salaries -Ing and the personal instruction of Mr. Roy C. ‘Claflin.

ious training is necessary to become a capable an with the help of the Columbia School of Draft- You can master the practical lessons of our famous home

Big Concerns Employ study course in your spare time at home, and becomea trained specialist through your choice of one of our special post graduate courses. Draftsmen Get $35 to $100 a Week

‘¢ Columbia Graduates’’ The best concerns in Amer- ica me el Columbia grad- uates in their drafting

Because of the importance of his work, the draftsman is paid a big and is always in line for advancement, A knowledge of drafting is the stepping stone to

departments because the therouale practical trainin ve them enables them to step right into important raft ng itions. Students of the Columbia School of Drafting often secure positions at $2000 or more a year to start before completing the course. Our diploma is the entering wedge into big drafting rooms everywhere. As one of our uates you are recognized as an experi draftsman. Our training spells Success for you. Many Opportunities Now We are called upon to place trained draftsmen more rapidly than we can produce them. General construction ——— manufacturers, railroads, ship buildin: draftsmen today in greater numbers bere ant concerns, engineering projects, all need at better salaries than ever before. Send This Coupon Today Let us tell you the fascinating story of drafting and how you can master this lucrative profess salaries and steady advancement through our help. Write today to " ct COLUMBIA SCHOOL OF D ROY C. CLAFLIN, Pres., Dept. 1183, 14th & T Sts., N. W., Washington, D.C big technical positions in the industrial field paying as high as $50,000 a year.

RAFTING

This Complete Rents Equip- *““ ment Furnish to students of our school. The instruments are of standard American make of the best quality, fully guaranteed, and become your property on completion of the course. Every instrument lease needed for the course is included me.

COLUMBIA gomocs. OF DRAFTING Claflin, President, Dept. fax 14th & T Sts., N. W., Washington, D.C. I am interested in your practical training in Moshastent Drafi send me Free, your illustrated book of iculars, testim: yal ' I am also interested in the s \perpanedaae course ow: (Mechanical Drafting, or Machine Draft is the foundation grone a is co in -) :: re Drafting". | “Highway -Highwa ——— eee MB cee wi y & |: Aeroplane a Se ae : ba “Sabtetiea i Drang Shay Sheet Metal Drafting. . . Radio Drafting ders’ en NINE ak bn bs. «has cn Cameeatcaccaieeel eden MME ata os accu OI 6 60's ce retick-ocen sacs nite bwatine ES pe ae oe eee ge NOE rE

CONCRETE ON THE FARM AND IN THE SHOP This new book illustrates and describes in plain simple language many of the numerous appliances of concrete within the range of the ae worker. Price, poet, $1.00 BOOK DEPARTMENT, POPULAR SCIE ee MONTHLY 225 West 39th Street, New ¥ Do You Work in a Factory? $10 to $25 a Week for an Hour a Day We want a representative in every factory in the United States. You can easily earn $10 to $25 extra each week by using an hour a day of your spare time Write oa giving the name of the factory where you are employed

ON CREDIT wg, DIAMONDS 3 >< WATCHES For Gifts Do your gift buying with- DIAMONDS Ut dela . while stocks are WIN HEARTS = and unbroken. Our

hopping to Sear te our 8 n handsome SSte-white 4 ts on edit. Whatever you s select will be sent pre . Youseeand examine the article right in your own hands. CREDIT of $5 or over, one-fifth TERMS on purchases down, balance in eight equal amounts, payabls e monthly,

We off ceptional values in these Ciemend Rings, Solitaires and Clusters, aptest ace = plain and fancy engraved mountings. The D mognit cent cont gomns. ont set in White, Green ond —- Solid iption, see catalog. Priced a $85, seer oor 6 $250 tae Forme ns chr

\ |“ ] prices cost her only $350. Wouldn't you call this

$200 Saved by This Home Lover One housewife had selected $550 worth of furnish- ings locally before learning of this new Larkin plan. The same selection at our low Factory-to-Family saving of $200 worth while? May we send all the interesting facts? 1000 Furnishings at 20c a Day Small as well as large Furnishi needs are easily and quickly filled under this Meltehttal plan. Pay- ments as low as 20c a day. Completely furnish an entire home or parts of several rooms this convenient way. Get This Bi 128-Page Book F REE i) Here is a complete guide for WH beautifying your home. You'll if Spend many profitable hours Wit looking over this Book of Better ii Homes. Write for it aol, Find 4] Qut how easily and economically jj your home can be brightened.

eth iets = r Ca ll FF LEER RR OE RTE

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AANA ON egal ei

sw’ DIAMONDS pnect FROM JASON WEILER & SONS of Boston, Mass., one of Amerca’s leading Diamond Importers For over 43 years the house of Jason Weiler & Sons, of ston, has been one of the leading dia- mond importing concerns in America selling to jew- elers. However, a large business is done direct by mail with customers at importing prices! Here are several diamond offers—direct to you by

Popular Science Monthly Have You a Step-Saving House? The Popular Science Monthly will pay ninety dollars for the best answers mail—which clearly demonstrate our position to name prices on diamonds that should surely inter- est any present or prospective diamond purchaser.

Men’s Diamond Ring $390.00 Perfectly cut blue white diamond of exceptional brilliancy. New octagon 14K. solid gold ring. Ladies’ All Platinum Diamond Ring 1 carat, $145.00 This one carat Gemend | ia of _— brilliancy and perfectly . Mounted in ihetany ats = 14K. solid ad setting. i refunded ‘ifit can be duplic ate elsewhere for less than directto you «= SPL 45

Six perfectly cut, blue white diamonds set on sides. Center diamond of fine color. Ring is ex- quisitely $450 and pierced $450 00 | | A few weights and prices of other diamond rings: 4 carat - ~ $31.00 1% carats = - $217.00 *% carat -=- 50.00 2 carats -= 620.00 44 carat-- 73.00 3 carats valuable Catalog Free W TO BUY on DIAMONDS”

This book is beautifully illustrated. Tells how to judge, select and buy diamonds. Tells how they mine, cut and market diamonds. This book, showing weights. sizes, Prices and quali- ties of a Million Dollars’ Writ worth of _Diamonds is rs for

considered an author- ity. your copy todav Free Jason Weiler & Sons 372 Washington Street, Boston, Mass. Diamond Importers since 1876 Foreign Agencies: Amsterdam and Paris

Build Your Own PHONOGRAPH

motors, tone arms, case om OY blue prints and fuil a Plays any record. Make fine profit building phonographs for your friends. oday f mrte Aone eg FREE AGENTS iite?icnographe Choraleon Phonograph Co.

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A few hours interesting work saves OVER over haif and gives one 8 machine to suit your ideas. e furnish , HA LF

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Send for them—NO Ow. a UNIVERSITY: WYER y trained men win eee lone big Am in business an: pooch. ng eee ag pm now thanever. Bealeader. Lawyers earn We guide you step bystep. Youcan

CHicago, "Ill, OW do you save steps in your home? What arrange- ments or what appliances have you made that save time and reduce work that would otherwise have to be done by hand? The Popular Science Monthly wants to know just what practical and useful things can be constructed to make every house a step-saving house. For instance: a con- cealed laundry chute would interest us, if it weren’t so old; a space-saving cupboard-—another old one. No patented or marketed appliances will be considered. The Popular Science Monthly offers three cash prizes— a first prize of $50, a second prize of $25, and a third prize of $15—to be awarded in accordance with the rules set forth below. Rules Governing the Contest (1) Contestants are not limited to the number of step-savers and time-savers, but only one method can possibly win the first prize, only one the second, and only one the third. The contest is open to everybody. (2) The method must be shown clearly either in a photograph or in a drawing. If a drawing is sent in, it need not be made by a skilled draftsman. It is sufficient that it should be _ intelligible. While pencil sketches will be con- sidered, contestants are requested to make their drawings in ink on heavy white paper. The views should be sufficient in number to set forth the writer’s idea very clearly. The contestant’s name and address should appear on each sheet of drawings. (3) The drawings or photo- graphs must be accompanied by a description, preferably type- written, in which the method is clearly given. It must be written on one side of the paper only, and it should not be more than 500 words in length. The name and address of the contestant should appear in the upper left-hand corner of the first sheet of the written description. (4) The drawings and descrip- tion entered by contestants must be received by the Popular Science Monthly not later than 5 p.: m. on Friday, December 31, 1920. (5) The judges ‘of the contest will be the editors of the Popular . Seience ‘Meattly. 126 (6) The first prize of $50 will be awarded to the contestant who, in the opinion of the judges, has suggested the best method for saving steps in the house. The second prize of $25 will be paid to the contestant who sub- mits a method next in merit. The third prize of $15 will be paid to the contestant who sub- mits the method third in merit. (7) The winners of the contest will be announced in the earliest possible issue of the Popular Science Monthly. A description of the methods which win the three prizes offered will duly appear in the pages of the Popular Science Monthly, together with the names of the winners. (8) The editors of the Popular Science Monthly shall have the right to publish meritorious manu- scripts which do not win a prize. The regular space rates will be paid to the contestants who sub- mit the manuscripts thus selected. (9) When a contestant submits more than one method, the de- scription and drawing by which each is set forth must be sent as a separate unit. (10) Manuscripts or drawings will be returned to contestants if stamps are enclosed. (11) Send drawings and specifi- cations to the Editor of the Step- Saving House, Popular Science Monthly, 225 West 39th Street, New York City. a an eee: hl

cl —a

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November, 1920 Cooling the Shelves of the Kitchen Closet CURRENT of cool air can be made to circulate through the shelves of a kitchen closet by cutting holes at the top and bottom through the flooring and walls and by using “icebox”’ shelves made of perforated 4 iron. The air can be kept cooler and cleaner if a length of sheet-iron fur- nace pipe is run 4 from the hole in the closet floor down into the cellar below, so that the open end of the pipe is but a few inches from the cellar floor. Then a cheese- cloth sack is made to fit over the open bottom and sides of the pipe and is hooks ed to the ceiling _ near the top of. the pipe. A shelf to hold a pan of water is put up near the top of the sack. A wick, sewed to the sack and dipped in the pan, serves to keep the sack damp and the air within the closet several degrees cooler than it is outside. The bottom of the sack over the open mouth of the pipe prevents par- ticles of dust entering the closet. During the winter months a damper in the pipe will be found useful. go CELLAR FLOOR Md Air circulating through the wet sack keeps the closet cold How to Apply Gold Leaf to Uneven Surfaces HILE patented gold leaf is the handiest to apply to flat, even surfaces, it is not so easy to use on depressed or uneven surfaces, espe- cially if the depressions are of some little depth. Nevertheless it some- times hap- FIG.2 pens that it PATENT GOLD-LEAF is the only ATEN “LEAF : METAL SIDE UP kind on hand. I find the best method is the follow- ing: If dabbed with a brush Lay a the dampened goid leaf will damp — not sink into the depressions wet—blotter on some flat surface. Place a sheet of the patent gold-leaf, metal side up, on it. Place a spent sheet on the metal and rub until the under side is evenly damp- ened. Remove the spent sheet and take up the dampened sheet of gold. It won’t tear. Place it against the sur- face to be gilded and dab with a bristle brush so as to drive the gold into the depressions. Nonember. 1920 TRADE-MARKS AND fe) AACE PATENT -opviticnTs SPECIAL OFFER patenrasie nature Before disclosing an invention, the inventor should write for our blank form ‘‘Evidence of Conception.’’ This should be signed and witnessed and if returned to us to- gether with mode! or sketch and description of the inven- tion, we will give our opinion as to its patentable nature. Our Three Books Mailed Free to Inventors Our Illustrated Guide BOOK HOW TOOBTAIN A PATENT Sent FREE on Request Contains full instructions regarding Patents, Trade-Marks, Foreign Patents. Our Methods, Terms, and 100 Mechanical Move- ments illustrated and described, Articles on Patent Practice and Procedure, and Law Points for inventors. OUR TRADE MARK BOOK Shows the value and necessity of Trade-Mark Protection and gives information regarding unfair competition. OUR FOREIGN BOOK We have Direct Agencies in all Foreign Countries. Write for our illustrated Guide Book on Foreign Patents. SPECIALIZATION Our Staff The field of invention is so vast that it is impossible for any one man to become an expert in all the different classes of invention. Only those practically skilled in the class to which the invention relates are capable of rendering efficient service. For this reason Victor J. Evans & Co, employ a number of patent lawyers and mechanical experts who have been selected for their special knowledge and ability in certain lines of invention. Each case is placed in charge of experts in the classes in which the invention relates. THE VALUE OF YOUR PATENT Will depend much upon the skill and care with which your case is prosecuted in the United States Patent Office. This work will receive the benefit of skill and experi- ence acquired by a long and successful practice. We spare neither time nor pains to secure the broadest possible patents that the inventions will warrant. That every case entrusted to us receives our best efforts, and that our work is done consistently, skillfully and thoroughly is evidenced by the many unsolicited letters of commenda- tion that we receive constantly from our clients. We will furnish upon request lists of clients from any State in the Union for whom we have secured patents. Our New York, Philadelphia, Pittsburgh, Chicago, and San Francisco Offices Owing to the growth of our business we have established for the benefit of our clients Branch Offices in New York City, Philadelphia, Pa., Pittsburgh, Pa., Chicago, Ill., and San Francisco, Cal. These branch offices being located in these large commercial cities, together with our Main Office located nearthe U. S. Patent office, in Washington, enables us to more promptly handle the business of our clients, particularly as the branch offices are in constant touch with the Main Office and fully equipped to handle patent business in all its branches. Highest References—Prompt Attention—Reasonable Terms al VICTOR J. EVANS & CO. i Patent Attorneys | , ve (DULL | 'f) | 1th ) i : Philedaiphia Pitsbergh ALi) i | soot Weacet dg, ESHA El i | Chicago Ofices, 1114 Tacoma Bldg. San Francisco Offices, Hobart Bldg. | Main Offices, 760 9th Street, Washington, D.C. ! | ii | Vn | Gentlemen: Please send me FREE OF CHARGE your books ii ie i : 19 eee Re ee ee Ree aR ae Address........ Re sc PL pe SORE ae SE Seika: nat TO RENO CC AC LUTE TTR RM 127 OA Sih RPI OI oe A SN SIE NES AG Se AC OOLESI MEL EEE —

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Pcacetnanr a 3 de RR A eter pins: br Aanennist Nan rapiane aaa nite coe an ae ee a Ee ee encanta ance lbeaemsesaes eerie SOT NM SRN ROAR PF NRE, papearcnprenyurtonsnapnmsesntarinaanen si PATENTS Write for free booklet Terms Reasonable Highest References Best Results Send model or drawing for preliminary examination and report as to patentability ALL BUSINESS GIVEN PROMPT AND PROPER ATTENTION WATSON E. COLEMAN, Patent Lawyer, 624 F St., Washington, D.C. PATENTS F YOU HAVE AN INVENTION which you wish to patent you can write fully and freely to Munn & Co. for advice in regard to the best way of obtaining protection. Please send sketches or a model of your invention and a description of the device, explain- ing its operation. All communications are strictly confi- dential. Our vast practice, extending over a period of seventy years, enables uc in many cases to advise in regard to patentability without any expense to the client. Our Hand-Book on Patents is sent free on request. This explains our methods, terms, etc., in regard to Patents, Trade Marks, Foreign Patents, etc. If you are a reader of SCIENTIFIC AMERICAN you are probably aware of the fact that it has a special appeal to the inventor. Each issue contains a description of a large number of recently pat- ented inventions. Pending pat- ent legislation as well as the most recent rulings of the Patent Office and the courts are considered in its columns. MUNN & CO. SOLICITORS OF PATENTS 683 Woolworth Building, New York 624 F Street, Washington, D. C. Tower Building - Chicago, IIl. Hobart Bldg., 582 Market Street, San Francisco, Calif. Before applying for a patent write for a Free Copy of our book “How to Obtain a Patent,”’ which contains valuable information and advice to inventors. Ittells how to secure Patents. Send a model or sketch of your invention for our ‘Evidence of Conception” form and our opinion of its patentable nature—Free. Twenty years’ experiencein patent matters. Write today for your FREE BOOK. L. T. S. Patents Five years ago, practically without capital, J. G. Tufford, Elyria, Ohio, and his associates Smith and ty started business with the now ie ee I. T. S. Rubber Heel under the Tufford U. S. and foreign patents obtained through Lacey & Lacey. Fourteen tons of these heels are now produced daily. The profits already amount to millions of dollars and foreign patents have been sold to the extent of $550,000.00. That demonstrates the financial possibilities even of an extremely simple invention of merit properly patented. READ PATENT-SENSE Saath ri “dhe Book for Inventors & Mfrs’ Mai LACEY & ~. Dept. PATENTS TRADE-MARKS Send for our free book of patent information Beale & Par COPYRIGHTS 804 F St., Washington, D. C. 16 S.Broad St., Philadelphia, Pa rete PROCURED and TRADE-MARKS REGISTERED | Twenty Years’ Experience. Instructions and Terms on request. ROBB, ROBB & HILL, Attorneys at Law Specializing in Patent and Trade-mark Practice exclusively 408 McLachlien Bldg., 1336 Schofield Bldg,, ashington, D. C. Cleveland, Ohio. patentable. nature. PATENTS SECURE A PATENT, send for Our Guide Book, HOW TO GET A PATENT, sent Free on request. etc. Send model or sketch and description of your invention and we’ will give our opinion as to its RANDOLPH & CO. 130 F St, N. W., Washington, D. C. IF YOU HAVE AN INVENTION and DESIRE TO LEARN HOW TO Tells our Terms, Methods, Pe er ee eee se oe Popular Science Monthly A Simple Wceod Insert for Cement Fence-Posts OST of the difficulty with cement fence-posts comes in supplying a suitable method of tacking the wires to them. This is easily over- come by the method described. A strip of wood, wider on one side than the other, is embedded in each concrete post, in the cast- . ing, with the it narrower side flush with the surface of the post. Lengths of / straight green ULE wood will suf- Lh ficeifseasoned ~~ wood can not be procured. Then, when the post is dry, this wood is solidly imbedded in it and presents a narrow strip down the entire length to which the strands of fencing may be tacked or otherwise attached. CONCRETE =) —~ How wire can be nailed to a wood strip inserted in concrete Get Your Chicken Binssies*: with a Lasso F course Miss Chicken may object to being roped in, as it were, but by using a lasso you are absolutely sure of having her for dinner. Scatter the corn as you always do when feeding the chickens, placing a cord lasso in a loop about it. Have plenty of slack to the end of the twine Corn is scattered inside the cord loop. As soon as the chicken gets inside, the loop is pulled tight and your dinner is ready to cook so.-as' to stand back far enough in order not: to frighten the fowl that you have your eye upon. When the bird walks into the loop, pull upward quickly until the loop tightens about her leg. Several of her friends may come in with her, but you can release the ones you don’t want. If the rooster, as in the illustration, tries to ‘‘corner” the grain-supply, patience. must be used to lure him away. Now usef the swe i Uy, lor in int to on in rf tr — ——

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November, 1920 Picking Up Threads Is No Easy Task HE thread-picker as shown in the illustration was found to be very useful in picking thread or hair from the floor. If this is done before you use your vacuum cleaner or carpet- sweeper, it will prevent the brushes Why not a thread-picker as well as a carpet-sweeper? It is easily made and will-save you from bending over from becoming entangled with the thread or hair. One will find this picker a very simple device to assemble. It can be made from a few pieces of wood pro- . cured from an_ old. soap-box, some 17%-in. brads, and an old- broom- headin Be sure that the side guides are longer than your brads when bent, in order that the brads will not stick into the rug, as the side guides are only to act as runners for the picker to ride on and to enable one to keep the brads in the proper length.—H. E. MENDE. Something to Know about Line-Shading N heavy line-shading—as in a Pat- ent Office drawing—there is a ten- dency for the ink to flow under the The accom- triangle and cause a blot. A FIG.1. VAY A Fig.2 \YS Your triangle won’t blot, even over heavy ink lines, if you raise it from the paper by cementing lugs on each corner panying illustration shows a device useful in such cases. : On the triangle B (Fig. 1) small triangular lugs are cemented on each corner. These should be placed slight- ly back from the edge as shown (Fig. 2). The triangle is thus held clear of the paper and may be used even over fresh ink. The triangle B should be fairly thick. The pieces A may be cut from an old triangle. If the triangle is made of hard rubber or celluloid, it is best to make the lugs of the same material, using rubber cement for fastening them. -— Trial you may have any instrument with complete musical ee or a week’s free trial at home. No obliga- tion. it at our expense after trial if you wish. Outfit includes velvet lined case, self instructor, music andall accessories at factory cost. A tremendous saving. Gicevinsioes Monthly Payments few cents a day will for instru t and outfit. W fteinneensy ey ay pg ae ty Ry ag Send Coupon for Beautiful New Catalog Every festrement known illustrated with on tune Gaye ten nae The Rudolph Wurlitzer Co. ++,Dept. | 1788 on o 4th 8t., Cincinnati,O.—3298 ve.. Chicago acaeeiatannaiasiien tie sof of Wark elit iiezer Complete Gutdes and tooo lat ead cow (State instrument you are specially interested in.) To the Man With an Idea I offer a most comprehensive, ex- perienced, efficient service for his prompt, legal protection and the development of his proposition. Send sketch, or model and description, for advice as to cost, search through prior United States patents, etc. Pre- liminary advice gladly furnished with- out charge. My. experience and familiarity with various arts, frequently enable me to accurately advise clients as to probable patentability before they go to any expense. Booklet of valuable information and form for proper! ayer seg your idea, free on request. rite today RICHARD B. OWEN Patent Lawyer. 6 om a Buliding, Weshingtom, D.C, 6-D Woolworth Building, New York — CAN YOU think of a simple, practical idea that will fill one of the many ree 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 book—“‘Invene tions and Trade Marks, Their Protection and _ Exploitation’’ and learn more about making money from ideas than you ever knew before. It tells many things that are wanted, C00. A postal will doa— it is free. we Lame the Goma — “of thele ADVERTISED wutieee ieee For SALE FREE Advice free. In INVENTION And book at once. "MN MANUFACTURING SUPPLEMENT. AMERICAN INDUSTRIES, INC. 201 Patent Dept., WASHINGTON, D. C. Published for the man with an idea. Send for free sample copy. One year’ssub- ‘ii scription 50c. es MEN Intensely interesting booklet free. Wonderful results. E. GYDE CO., Washington, D.C. et AS DS Before disclosing your invention to anyone, send for blank form *‘Evi- dence of Conception” to be signed and witnessed. Form and infor- J mation concerning patents FREE, LANCASTER AND ALLWINE 274 Ouray Building, Washington, D.C. § (Oriyinators of the form ** Evidence WILLIAM C. LINTON Consulting Engineer and Patent Attorney “Inventor’s Adviser’’ Mailed free on request. Gives full information as to Patents, Trade Marks and Their Cost OFFICES 364 UNIVERSITY ST., 6 F ST. N Montreal, Canada. Waetington D. ve. 129 —— ad PERL ETACHPC ERAT ARO RE THT Pate ee etree eeerer eating PATENTS Trade Marks Send sketch or model for actual search and report. Write for Book- let of instructions on patent practice and procedure. Prompt personal service.... Geo. P Kimmel Patent Lawyer seeresrio ceeeerteteeeeteaenetan - - . « - - Teprtverear COE Pe DOSE UGHASGAUSCRASBOLECT OR OR ROME PA AU CRD OLED AERA EAT EC RET OT EP PRB AR EEL ETS 39-L Loan and Trust Building, Washington, D.C. - TTC ECCE AE LAER eee ee SoS SAL ei eee a RS a aE pode =e : ime 5 ee

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e Learn Drafting Employers everywhere are looking for skilled draftsmen. They are offering good salaries to start with splendid chance for advancement. Drafting offers exceptional opportu- nities to a young man because drafting itself not only commands good pay, but it is the first step toward success in Mechanical or Structural Engineering or Architecture. And drafting is just the kind of work a boy likes to do. There is an easy delightful way in which you can learn right at home in spare time. For 29 years the Inter- national Correspondence Schools have been giving boys just the training they need for success in Drafting and more than 200 other subjects. “Thousands of boys have stepped into good positions through I. C. S. help, but never were opportunities so great as now. Let the I. C. S. help you. Choose the work you like best in the coupon, then mark and mail it. This doesn’t obligate you in the least and will bring you information that may start you on a successful ¢areer. ‘This is your chance. Don’t let it slip by. Mark and mail this coupon now. — A on A ee A GUT be Se ee en, Com ee INTERNATIONAL CORRESPONDENCE SCHOOLS » SCRANTON, PA. Explain, > ma cng mer how I can outs for the

position, or in the sub: which I m: BLECLNIOAL, ENGINEER SALESMANSHE ig ond Rys. Electric Wiring Window Trimmer EN Bantncer Show Card Writer Telep' e Work Sign Painter msonanioaL ENGINEER Railroad Trainmaa Mechanical Draftsman ILLUSTRATING Toolmaker BUSINESS SAN, GEERT A Gas Engine Operating Private oe md Hepping BOOKKEEPER rveying an pe | Stenographer and NE FOREMAN o aR Cert. Pub. peo STATIONARY ENGINEER TRAFFIC MANAGER Marine Engineer Railway Segguaanat Ship Drafteman Commercial La ARC GOOD ENGLISH Centractor and Railder < Teacher Architectural Drafteman Common tow Subjects Concrete —.. CIVIL SERVICE Structural Engineer ~ alg ry Clerk PLUMBING AND HEATING AUTOMOBILE OPERATING Sheet Metal Worker Auto Repairing Textile Overseer or Supt. Navigation Spanish OHEMIST acacoutine | French Mathematics Poultry Raising § (Italian Name. Present . Occupati Street and No = City. State.

Canadians may send this coupon to 7-25-10 International Correspondence Schools, Montreal, Canada

A Tool for Removing Spindle Bushings ARTS of machines such as spindle bushings are often difficult to drive out. With a tool like the one herein described, however, the job becomes much easier. Get a piece of round tool steel a trifle smaller than the spindle’s inside diameter. Soften the bar and saw up through the middle for ie about half its | length. This — makes it ap- iM Z-— BUSHING pear something like a large

cotter-pin. SPINDLE Smooth down nicely and re- harden afterthe BUSHING tines are spread somewhat as shown. The tool is inserted, handle first, through the exposed end of the bushing and pulled through until the tines spring out and rest on the inside face of the bushing. Then the top of the handle is tapped with a soft hammer until the bushing is started. By providing oneself with several sizes of these tools, practically any size bushing of similar character can be handled by the machinist. A steel bar cut through the middle removes spindle bushings Making a Trestle that Can Be Folded Easily COLLAPSIBLE trestle is easily constructed and can be conve- niently stored when not in use, or easily transferred from place to place, as occasion may require. It can be made from as heavy ma- terial as the work requires. The legs, instead of being nailed permanently to the heavy timber used to hold them together, are attached by hinges. | 4 FOLDED ie i N stan IRON This compact collapsible trestle can be stored and easily moved about by the workman

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The legs may also be spliced by gate-hinges. They are then locked by pieces of strap iron, having notches cut in them, which drop over project- ing nails, preventing the legs spreading. The ends and sides are both supplied in this manner. When a shorter trestle is desired, these braces are removed, allowing the legs to unfold at the hinge and rest at this joint, while they are secured by the braces above in a similar manner as before.—C. C. WAGNER. 130 Popular Science Monthly How to Become a Successful Electrician Get the Electrician’s Wiring Manual, by F. F. Sengstock, E. E., the new 1920 Edition. This big book gives complete and accurate directions for all kinds of elec- trical wiring. The author is an electrical engineer with many years’ experience as an inspec- tor on the Chicago Board of Underwriters, and you can de- pend upon this manual. It’s not a “high-brow” treatise, but is written in simple, plain English, and so thoroughly illustrated that it is easily understood even by the amateur electrician. In short, the questions that the electrical worker wants answered by the electrical inspector are discussed just as the author has talked them over with “the man on the job.” Follow the directions in this manual and you need not worry about your work being approved by the. in- spector. Glance over this list of chapter titles and you will see why you should have the Electrician’s Wiring Manual Tools and Symbols—Preliminary Suggestions on Building Wiring— Moulding—Flexible Conduit—Rigid Conduit—Fixtures and Their Instal- lation—Switches—General Sugges- tions on House Wiring—Installing Household Electrical Utensils—Wires and Cords — Motors —Transformers —Switchboards and Panels—Motion Picture Theater—Bell Circuits, An- nunciator Circuits, Gas Lighters, Burglar Alarms, Bell Transformers, Door Lock—Elevators—Wiring in Damp Places—Outside Wiring— Grounding and Ground Detectors— Inspector’s Report on a Defective Electrical Equipment— Estimating and Specifications—Tables and For- mulas—Electrical Circuits, Calcula- tion of Wiring, Line Losses and Na- tional Electrical Code Discussed for the Beginner—Alternating Currents Simply Explained—Some Things the Electrician Should Know About Storage Batteries—Underwriters’ Re- quirements in the Installation of Wireless Telegraph Equipment— Practical Kinks. There are many formulas and tables which are of great value to the electrician. This is a book every wide-awake electrician or any one who wishes to do any wiring should own. Don’t take chances, but be sure your work will pass the fire in- spector. This Manual may save you 100 times the price of the book. 448 Pages, 414 Illustrations, Hand- some Flexible binding. Pocket size. Price, postpaid, $3.00. Popular Science Monthly

225 W. 39th St., New York City « Popular Science Monthly,

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November, 1920 Electric-Light Bulbs Make Good Clothes-Sprinklers ANY women sprinkle their M clothes by hand, and many more go to the trouble of purchasing a clothes-sprinkler when they could easily make one at home. Here isa way of making your own clothes- sprinkler that will do the work as efficiently as any factory-made arti- cle. Procure a blown-out electric-light bulb, one with the inside wires broken (if the glass itself is broken, the bulb will not do), and immerse the bulb in a basin of water. -File or break off the tip of it. As the file eats through the glass the water will rush into the By breaking the tip from an old electric- light bulb in water it can be used suc- cessfully as a clothes-sprinkler bulb, and upon taking it out of the basin the water will stay inside until a shake releases it.—A. GOLDENBAUM. Did the Telephone Company Know About It? AVING occasion to use my tele- phone downstairs during the day and upstairs during the night, but believing the convenience thereby ob- tained did not warrant the rental re- quired by the telephone company to install and maintain a second instru- ment, I purchased two telephone jacks and a plug. The telephone-box con- taining the coils and the bell was already in a convenient location and the bell could be heard distinctly all over the house. On the end of the cord of the tele- phone-desk stand, which was normally connected with the telephone-box, I placed the plug. A three-wire strand was connected with the terminals of the box and run to both jacks. One jack was located in a convenient place downstairs and the other upstairs. Disconnecting the telephone instru- ment from either jack does not. inter- fere with the ringing of the bell. November, 1920 in Motor - Mechanics _. the Best Trainingy Prepare yourself for the best jobs with the biggest pay—on the farm and in the city. Enormous demand for real motor mechanics—for men who can locate trouble instantly and make adjustments and repairs quickly. Our master mechanics teach by the most standard, practical, ‘‘horse sense’? methods. Our Test and Trouble work alone is worth the price of the course. Learn by Big Shop Standards In Seven Weeks. Learn where you work with the most modern equipment and motors of latest design, including the Liberty Motor—slowly, surely, step by step. Our graduates are recognized everywhere as exceptionally competent workmen. Thousands are holding fine positions or making money fast running their own garages. Life membership privileges. White students only accepted. SPECIAL BUSINESS COURSE—shop records and manage ment—included in regular course. Y. M. C. A. MEMBERSHIP—swimming pool, boxing, Ay \ wrestling, etc.—no extra charge. Se FREE BOOK. send forit today. It tellsall—showsall, Soy FRANK D. HENNESSY, President (5 oh IOWA STATE AUTO & TRACTOR SCHOOL oe Oe) “The Quality School” 5 @. > Pe Pronounced by Official Inspectors “‘one of the Seg best schools in the country. See 2 ; 769 Nebraska St., Sioux City, Iowa IG oe ws - Official Hart-Parr School for training & Ss 2 purchasers of their tractors in tractor “r . care, repair and operation. ° eo g & ee E PRIN SHI PFITTERS, Structural Workers,Carpenters, Bricklayers, Mechanics ,Plumbers,Pipefitters, Boilermakers, Sheet Metal Workers and others can earn more money if they know how to read Blue Prints. By our method, we train you in a short time. Write for Catalog B, stating trade. We also teach Dra a a Draftsman! Earn big money. Books and tools FREE, Write for Catalog G. COLUMBIA CORRESPONDENCE SCHOOL Est. 1904 Dept. O, Drexel Bidg., Phila., Pa. YOUCAN DO IT! START TODAY! If you are clinging to a low-pay, insignificant place in the business world, just because you think you don’t know as much, or that you aren’t as “clever,” or that you haven't as good an opportunity as the ‘‘bigger’’ men of your community, you are the man I’m talking to—because I know you are mistaken. The ‘Puckett Method” has started hundreds of dissatisfied mid- dle aged men and young men on the high road to financial success. All I want is a chance to show you, and I know I can show you if you will send me, at once, the attached coupon. This will take but a moment—and a two cent stamp—and it may mean the turning point in your life, for I claim any man or boy who will study and apply the principles of the “Puckett Method” to his life for one year, will DOUBLE HIS INCOME. 7 & Af Puckett Learn the secret of success—that success which comes with ¢—=: + . (@) the assurance of money in the bank, of work well done,of AS » service well rendered, and of joy and comfort in the home. 43° Ss If you will only give me the opportunity to “jar you loose’’—to induce you to lift up IPs 8 SH your head—to make your eyes sparkle with a new confidence in yourself—and to cause 4 oe ‘oO you to rise up and go after the bigger things of life which you long to possess—in short, 4 Pees ax if you will let the ‘Puckett Method”’ point you to real, substantial, financial success, 7H ES fe I know you will rejoice to theend of your days that you chanced to see this page. CEES SS I want you to know all about the ‘“‘Puckett Method.” Send the coupon 7 “ws wee today for a FREE copy of the booklet: “HOW TO DOUBLE YOUR INCOME IN ONE YEAR.” IISE Mail the coupon to THE PUCKETT METHOD CORPORATION Z Rg se E. W. PUCKETT, President ISS SS 352 West Wayne St., Fort Wayne, Indiana IS VEL 4 4 EEX MAIL IT TODAY “e // eccentenen. 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pos Sears ape a apacrer ueoeneneae mn iaerrere Ds oa ete OR NEARS PASE My mma mann ee Se a eee $100.00 A WEEK' ge! Ni ME Old KX R. CHAS. EVANS, Ind., car- penter, past fifty, laid aside saw and hammer, learned Tire ia, oad within two weeks, nowhasthriving Tire Surgery Station shown above. Averages $100 a week. Alwayshasmoney in pocket. Never pinched for ready cash. n’t have to wait for ag Money flows in every hour of day. It’s a proposition YOU can handle. Let me equip a TrESBSS Station for YOU. Learn Tire Surgery—the new tire repairing method. The QUICK and BETTER way for repairing old, worn, ragged and torn casings. Adds 3,000 to 5, mileage. I teach you in fourteen short days. Show —_ how to be SUC- CESSFUL MANAGER. Tell you how to build BIG , TRADE quickly. Giveyou pointers that Pasko you SUCCESSFUL rom VERY START, I put you into auto industry — the business that makes millionaires. Place you in DIRECT LINE for SPEEDY RAISE in HIGHLY PROFITABLE FIELD. Nothing can stop you. Need noexperience. No special qualifications. No high education. Age makes no difference. $3,000 to $5,000 Year —average earnings. Many make more. Chances for sensational success never ° Seven million cars swarming over the country. Twenty-eight million tires in constant use. All are wearing down, being cut, blown out, bruised and gashed hourly. Casings by thousands roll- ing into Tire Surgery Stations for repairs. Get —e L.~ o bas ag te po ceeds oe ness. astation quick. coupon and within ONE BRIEF MONTH I’ll have IMIG CHANCE? A money-making opportunity money-making o i youcannotafford to overlook! Full details caly cost you red stamp. Get Facts—Filleut Coupon Write name and address plainly. Mail it — Get my big, interesting book by RE- URN MAIL. Read what others have done. Read what YOU CAN DO. Find out how to be own boss. How to be paid for what you do— not for hours you work. Learn how easy you ean get into big paying, permanent business, Fill out coupon—and SEND IT NOW! Haywood Tire & Equipment Co., 794 Saleh ives Eedianngalt > Ke Cc ES Ba MR. M. HAYWOOD, Pres. Hevwood Tire & Equipment Co., 794 Capitol Ave., Indianapolis, ind. Dear Sir—I_ want to get into big paying business quick. Please send me your propo- sition at once. Yours truly, _ En Se ee | Lr@sident- Suspenders _for confort y oy Every pair guaranteed | MADE AT SHIRLEY M $15 A WEEK FOR SPARE TIME WORK OR $60.00 to $90.00 a Week for Whole Time That’s what being a local representative for POPULAR SCIENCE MONTHLY can bring to you. If you are willing to hustle, then we want you. Popular Science Monthly Some Ways to Avoid the Repairman OMPARATIVELY few ownersand drivers of automobiles are aware of the value of soap for sealing leaky joints in the gasoline system. Very frequently gasoline oozes out around the filler cap, especially when the tank is nearly full. Such a leak is objec- tionable because the gasoline spreads over the outside of the tank, which nowadays is usually carried at the rear of the car, collects dust and im- pairs the finish. A coating of ordinary soap on the gasket and threads will REG prevent leakage, aXe even when the tank is full. Many automo- biles have no pro- vision aside from a strainer in the tank for keeping dirt from the car- buretor. Owners of such vehicles will do well to fit a trap in the fuel line.. All the big carburetor makers offer these traps, which are to be placed in the line near the carburetor or in the bottom of the tank. The trap catches all the dirt and water and should be cleaned out regularly once a month. In taking battery readings with the hydrometer the operation should be performed before the distilled water is added to the solution, which will other- wise be diluted and a wrong reading given. Also, after the water has been put in, it takes some time to mix with the acid. The water, being lighter, stays on top, and if the hydrometer is used, say an hour after the water has been added, it will wrongly indicate a weak solution. It is common to find automobile frames that sag in the middle after a considerable period of service. Some- times this condition produces diffi- culty in clutch-shifting and other mechanical operations because the various parts have been twisted a little out of alinement. The proper way to cure a sagging frame is to fit a truss-rod with a turnbuckle under the sagging portion of the frame. If the owner cannot carry out the repair himself, any machinery shop or garage can do the work. If dash and tail lamps are in series, the failure of the dash lamp puts the ‘tail light out of commission. Very often a makeshift repair can be made in the following manner: Smash the burned-out lamp-bulb so as to gain access to the inside of the lamp. You will see protruding from the glass stem two so-called ‘‘leading-in” wires. By twisting these leading-in wires to- gether and putting the lamp base back into the socket, you again establish an unbroken path for the current and your tail light, at least, will burn. If the tail light should give out, shift the 132 tis IE Immediate attention given to unusual engine noises will keep your automobile away from the repairman dash lamp to the rear and put the twisted-together base of the burned- out tail light to the socket of the dash light. Needless to say, this wire- twisting stunt works also in the case of a burned-out or injured head lamp, provided they are in series; in this case you have at least one head lamp to proceed with. It must be borne in mind, however, that when a single series-connected lamp takes the full voltage of the system, it is apt to =——— trevrme burn out if the : im SFricer storage battery carries a top- notch charge, or if the generator de- velops sudden bursts of excess current, as may happen when the motor is made to race in pulling out of a snowdrift or mudhole. But with reasonable care in driving, the single lamp, together with the twisted-together remnant of the broken bulb, will do emergency service until a new lamp can be secured. Tire repairing on the road is never a pleasant pastime, and we are not likely to exercise much care about details, especially when they seem unessential. There is one small thing often over- looked which has much effect later. If the tube is allowed to get into the dust, and particlesofsand or grit stick to it, or if these find their way into thecase, more trouble is ahead. In time you will find your tube full of tiny holesasif fine glass had done the work. The inner tubes should never be allowed to touch the ground, and before they are put in place they should be carefully cleansed of any grit which may adhere to them. Conserve the tube. Watch the grit. Air leaks are a common cause of misfiring, though they are often over- looked. A worn valve guide allows enough air to be sucked into the cylin- der to cause misfiring, and it also per- mits oil to leak out. If oil is discovered leaking out, it is fair to assume that excess air is being injected into the fuel charges. When a keyway becomes worn, the first thought of the owner is to file the channel larger and fit a larger key. To do this often weakens the metal seriously, and it may be found that a preferable way is to weld new metal into the old slot and then cut a new keyway to fit the old key. In lubricating automobile springs, the greatest trouble is found in keep- ing the lubricant from being squeezed out under pressure. A compound that obviates this is found in graphite and beeswax mixed to a paste and spread upon each leaf. Obviously the spring must be taken apart to apply this lubricant. > | nereewaermdsatet. - of ao& oo ol eel

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November, 1920 A Handy Test-Tube Holder for the Laboratory EST tubes are frequently broken because they are left lying about the bench. Why not have a holder for them? ‘That old discarded poker-chip holder so popular years ago can be utilized to good advan- tage for hold- ing the extra test-tubes, as shown. If necessary or advanta- geous, fit a round board to the bottom and attach a spindle to it which will re- volve upon a base. Or else suspend the holder from the ceiling with a wire. Such a holder will take care of sev- eral test-tubes of different diameters and prove a useful way of utilizing cast-off poker properties.

[A poker-chip holder makes a handy test-tube rack A Universal Joint to Be Used in Light Work SATISFACTORY universal joint for light work is made as shown in the accompanying illustration, and it has the advantage of running in absolute silence. It requires no lu- brication, and will not wear, provided it is not overloaded. Split the ends of the shafts to be jointed, heat the split ends to a low red, and bend the two parts in opposite directions at right angles, being careful to have them exactly at right angles. Drill the arms near the ends for small bolts, taking care not to make the holes so large as to unduly weaken the steel. Cut a piece of heavy leather into a disk and bolt the arms of the shafts to it, the arms of A i \ uy Hh.

SHAFT SPLIT AND BENT TO FORM ARMS

This universal joint requires no lubri- cation and will run silently provided it is not overloaded one shaft being at right angles to those of the other. It is necessary to exer- cise a good deal of care in getting the shafts exactly in line; otherwise the joint will wabble when it runs, and there will be pressure on the bearings and vibration if the speed is high. Perhaps the best way to do this is to bring up temporary bearings of wood blocks drilled a snug fit for the shafts, line them up with a solid shaft, and then put the two shafts to be

I CAN HELP YOU-2% THIS BOOK ON —. w zit _ z 18 240) (10) 29s hy ul RE you one of those languid, tired out fellows disinclined to go out into the world and make a fight for a place for yourself and familyP Are you a croaker and a grouchy, grumpy clod whom no- body wants around? : Are You To Blame? __ _No one should be blamed for being dumpy, grouchy, disheartened if he feels all off when he rises in the morning and feels languid and sluggish all day; but anyone should be blamed who permits such a con- dition of the body and mind to ruin his whole life and the lives of those about him without making an effort to throw off disease and ill-health —when I stand ready to help him—when I offer to place within his grasp a system of self-cure, of rehabilitation, upbuilding and strength- ening, that is leading the way in making better men, happier men out of thousands who had counted themselves failures.

You should be blamed if you refuse to listen J to the advice of the man who first made of him- self the most perfect specimen of manhood in the world and who now extends his hand to you and | offers to point the way to health, strength, happi- ness and hopefulness. STRONGFORTISM Is A Science In Itself It makes men new. It. awakens slumbering ambition. It puts pep into the languid fellow. It sends.a new thrill of energy through the body —fills it with the desire to do, to achieve. It rids the system of disease without the use of drugs or medicine, clears the mind of despondency—makes the world look brighter and life more worth liv- ing for. I GUARANTEE 100 PER CENT RESULTS I guarantee to improve you 100 per cent physically and mentally, if you will follow my directions. It makes no difference where you live, what your present- condition is or what has brought you to it. You can follow out my course without inter- fering in any way with your present occupation in the privacy of your own bedchamber if you like.

LIONEL STRONGFORT Dr. Sargent, of Harvard, declared that ‘‘Strongfort is unquestionably the finest specimen of physical devel- opment ever seen. FREE CONSULTATION COUPON Absolutely Confidential MY BOOK IS FREE | ier emer. ‘ k, N. J.; Personal—Pliease send me your book ‘*PROMOTION AND Send for my FREE BOOK, ‘‘Promo- | CONSERVATION. yor (HEALTH, STRENGTH AND ° : ENTAL , ,”” for t: b 1 tion and Conservation of Health, q three 2-cent stamps. i have starked (X) before the cablect Strength, and Mental Energy.’’ in‘which I am interested. ~«

COCO EEHEEHE HEHEHE EEE EEE E EEE OEE EES LIONEL STRONGFORT Physical and Health Specialist 56 Strongfort Institute Name AGB. cocccscccvececece Occupation Street Catia csecbasvawises cates wee eee SS OBeeeeeeees PCOS EEE ESTEE HEHEHE EHH EEE EEE ESE EEE HEHE 4 » aeenen.. + - een, Ceeaees <a send itin TODAY. You'll hear from me : : - Noureigia, . ty 4 ER, —_ ‘Strength . by return mail with a message that will 4 .: Deformity :!PoorCirculation ..Many-Weight Fe (describe) ..Increased Barbell be a revelation. § . Insomnia Height . Professional i .. Short Wind ..Skin Disorders Training q 4 i q t NEWARK, N. J. Jee eee eee eee eee ee

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SOE GR oR mee - At a Cost of 1 ic a Cord! gay size logat the rate of a foot a minute. the work of ten men, As easily K Send today for Big Special Offer and Low | moved from log to} Direct Price on the OTTAWA, the One- wheelbenvew.” “Cycle Frost Proof a 2 Man Saw, the first made and sold direct a from factory touser. Greatest ~ and money-maker ever invented. pe - polanesd crank s' ecid for soldering iron. Joins or t fo) ba wires, metals or metalware A Sold by hardware and electrical ) - stores or sent by us postpaid. , BINATI roi Jy fe $1. 50 SOLDERALL CO., Dept. A 129 Sussex Ave.. NEWARK, N. J. Dealers Send for Quantity Price

TOOL CASES EXCEL Machinists, Tool Makers and Carpenters’ find them most satisfactory in construction, appearance, service and price. Immediate shipment. Booklet describing 20 styles on request. The Pilliod Lumber Co. Dept. A, Swanton, Ohio HANDY ATLAS OF THE WORLD Printed from brand new plates with maps in 3 colors. Water in blue—Mountains in re- lief,—and all Railroads named. Shows each State of the United States all the Provinces of Canada and the Continents of the World. Price in Cloth, $1.00 and in Leather, $1.50. Postage,10 cents, Book Department. POPULAR SCIENCE MONTHLY 225 West 39th Street ss New York Wrum Pilliod

ASBESTOS We are miners and shippers of Crude Asbestos in any quantity. We produce all grades at our world famous BELL ASBESTOS MINES, in Canada. We also card fibres, spin yarns, weave cloths, and make all sorts of Asbestos products. For anything you want in Asbestos, turn to KEASBEY & MATTISON COMPANY Dept. S-4. AMBLER, PENNA., U. S. A. Owners of the world’s largest Asbestos Mines

Make Big Money— 1p With a Saxophone! |; LAYERS are alwaysin demand at good prices because the saxo- }% phone is today’s popular instru-} > ment. It’s easy to play; learn the | — scale in an hour, popular airs ina} = short time. 3 GET THIS FREE BOOK — story of | — the saxophone; all band and orches- | ~ tra instruments. Cultivate Your

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BY ONE MAN. It’s yt = THE yg Saves money and ee at eet o agency. Folding Sawing Machine Co., 161 West Harrison St., Chicago, lil.

electrical, rope, air- plane, piano, pipe- organ, flat, hoops, bale-ties, tacks, nails, barbed-wire, concrete re- inforce- ting, wire fences, steel pos bonds, wire wheels, oe Mane ye , horse-shoes. Illustrated Books Describing Uses, FREE American Steel & Wire Co. *-B*kss¥.F.and6. S.A

Send You a Lachnite } DONT send « penaz. Just send name and say 4 id ring on 10 mounted in a solid gold fir trial W Wa ion send it repaid right to your m0 dope comes merely deposi: _ 5 with the postman then wear the ring for 10 full days. if you trom a diamond, send

Popular Science Monthly jointed into the temporary bearings to mark the places for the holes in the leather disk. Put a good large washer on each side of the leather before screwing down the nuts. Rivets may be used if desired, and they are just as good if it is not necessary to take the joint apart.—HOWARD GREENE. Do You Know the Proper Way to Sharpen Drills? T is surprising to learn of thesmall number of mechanics who can boast of knowing how to sharpen a drill. To those who would like to learn the proper method of grinding we offer this advice: The mechanic should bear in mind the following factors: That both cut- ting lips of the drill must have the same angle to the axis; otherwise the cutting will be done on one lip and

Oa aa aE 4 uy hig. Hold the drill to be sharpened lightly against the grinding wheel and watch it carefully to see that it does not burn the drill will bore oversize. Both cutting-lips should be of the same leagth. If they are not, it will throw the point off center. Proper clearance at the back of the cutting edge is absolutely necessary. Insufficient clearance causes the drill to drag, cut hard, and then get dull very soon. The angle of the lips should be sixty degrees for best re- sults. Begin by holding the drill lightly against the cutting wheel, with the cutting lip on the wheel. The wheels for use in drill grinding should be fairly soft and open so that they will not clog or burn. The drill must be lightly pressed against the wheel and carefully watched to see that it is not burned and the temper drawn. Twisv the drill and at the same time throw the hand down in order to grind the clearance.—RONALD L. PRINDLE. iar S..-. i -e 2a — a

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November, 1920 Making a Grooved Pulley from Barrel-Heads FTENTIMES a grooved wheel of fairly large diameter is wanted for temporary or rough use. Such a pulley, built of wood, can be con- structed of two barrel-heads and a third wooden disk with a flat edge. Cut the disk out of stock, the thick- ness of which is as wide or wider than the belt to be used. Its di- ameter should be the same as the smallest di- ameter of the barrel-head at the bottom of the bevel. Screw the sections of each barrel-head to each side of the disk so they will be concen- tric with each other, and bore a shaft-hole through the center. Setting the grain of each barrel-head at right angles to that of the other will prevent warping. Temporary grooved wheels or pulleys made from barrel-heads A Portable Cabinet Made from Match-Boxes AKE six empty match - boxes. Glue them together as shown in the illustration and glue stout wrap- ping-paper around the whole. You now. have a cabinet with six drawers that will fit comfortably in the coat pocket. Further improvements can be added in the way of index labels pasted on the front of the drawers and little knobs for pulling them out. The cabinet may be strengthened by wind- ing strong thread or pasting thin card- board around the outside before the wrapping-paper is glued on. The cab- inet may be increased in size, or it may be altered to fit some particular pigeonhole in the desk or tool-chest. This little machine-part filing cabinet was made of six match-boxes bound with wrapping-paper It is used by the carpenter to keep assorted sizes of brads and screws; by the machinist to keep small sizes of nuts, bolts, cotter-pins, etc.; by the watchmaker for small parts; in fact, the extent of its use is limited only by the number of trades that use different sized parts which should be kept sepa- rated.—MYRON DRACHMAN. Rlanomhor .100N Good Tools Better Work—Better Pay For seventy years mechanics have used Brown & Sharpe Tools .as stepping stones to success, Catalog 28 —our new small tool catalog—lists a thousand tools with a million uses. Some of them are just the tools you need. Accurate, reliable, finely fin- ished tools. You'll be proud to own them. Send today for Catalog 28 Brown & Sharpe Mfg. Co. Providence, R. I., U.S. A. geet ns Wireless Tlikecaal Transformers With which any amateur can cover great distances. Write today for Bulletin on Wire- less. EXPLOSION. WHISTLE EFFICIENCY fa your warning signal means safety to ife and property. No factor contributes more to personal safety and the elimination of need- less repair bills than the Buell Explosion Whistle. Over 200,000 now in use. Equipment for more than 96 manufacturers. Effective, reliable, durable. Guaranteed for 10 years. In Single Tone or Chime. Buy it from your dealer or write us direct. BUELL MFG. CO. Cottage Grove at 30th, - - go Warren, Ohio Chicago FACTORY GUARANTEED NE ALL SIZES hive crag Cod Gavel Eten ie nitase, he C.,220v, 110 oF 220 volts, ene.1750 RPM. Complete 1700 R. P.M. Wits bone paliey end res with hase and pulley. 4 Senn ap. YEP. - - $46.50 V4 Sake os ais. $2850 V4 roe $28.50 50 1/4 Ri “~~ so V2 . $46.50 8v. 10am. --- $19.50 once $8650 _— es - $82.50 Hitlers $54.50 iaiereset $26.50 3uP. . $98.50 our. - $124.50 1 itt teers” . $74.50 40 v, 6 amp. - - uP. 110 v, 2% amp. $31.50 vines S116. 50 3 up. - - $142.50 Bee iB ce 110 v,Samp.-- $52.50 mee $10e 50 § uP. - - $218.50 5 Pry ee $188.50 40, 12amp. -- $52.50 WRITE FOR CATALOG. BARGAINS 16 MOTORS AND GENERATORS “% siding bose 110 v, 9% amp. $67.50 ———— 40 v, 25 amp. -- $67.50 pt 110+, 18amp. $116.50 “ oo Pic ctiy C.,@ >. M. with acta Sai HM lighting, Bat table for a Rites. B tery TMP. Requirements, 40v.,50amp. $1 16.50 110v,26amp. $156.50 15% dopa ‘110v,S0amp. $238.50 SHIPPING TERMS: Express. Sight MANUFACTURERS’ DISTRIBUTER Comers. 2116.50 CHAS. H. JONNSTON, Box rE meal

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en ee 4 me ae spss Pu A TP or le igi teen ee — pam ipeionsneren reves wages fo hs rene bpretions opiates sneer metas ats et em) aa et A me PS EA NT Oe mE IES AL tg mean a Red Devil AUTOMATIC FEED BALL BEARING CHAIN DRILL No. 2012 Used with a Bit Brace N excellent drill for metal work. The Red Devil Chain Drill drills engine cylinders, sheetsteel, steel beams, wagon tires, safes, boilers, pipes, flanges, etc. Can be used asa clamp. Works with a bit-brace, hand-drill, breast-drill, or even a wrench. It has a hardened steel ball race and is fitted with a nickel plated Universal Chuck which takes round or square shank drills from 3/16 to 3/8 inch. Yoke finished in red-enamel and equipped with a three foot polished steel chain, it looks to be and is a strictly high grade tool, fully up to the ‘‘Red Devil” standard. If not at dealer’s, send his name and $4.00 SRSA Booklet of Mechanics’ Tools on request Pliers, Automobile Chisel and Punch Kits, Automobile Tools, Glass Cutters, Auger Bits, Bearing Scrapers, Electricians’ Tools, etc., etc. SMITH & HEMENWAY CO., Inc. 260 Broadway, - New York ee Rn ees ee srmene ne rataglimen fname — saree nese eet mea _ garrat a on Your Drag Saw Big increase in my facto enables me to make lowest_cas offer on a Drag Log Saw. Lever Control to Start or Stop Saw while engine runs, Arm Swing pole ng acne with speed ON LY magus Oe. ey ead | ? 4 00 i> F. 0. B. Kan HOW 131) \ etme F.0.B. KANSAS CITY Electricians’ Knife and Tweezers We can meet dealers’ demands at once and offer attractive quantity prices Write for description MATHIAS KLEIN & SONS, Mfrs. CANAL STA. 3, CHICAGO Get My Special Prices now being made on Stationary and Portable Engines—in sizes 2, 3,4, 6, 8, 12, 16 22 and 30 H-P. Also, Power Cut-Off Saws for sawing cord wood and pole wood. This $125 Offer on WITTE Drag Log Sawsis for immediate acceptance, Don’t waitif you want to get in on this big advertising offer. You know if it’s a WITTE, it’s allright. Quick shipment, have your banker wire or- der, or mail order today and Save $50. Ad- -dress your nearest shipping point, 4 WITTE ENGINE WORKS Co a The Midget Slide Rule will instantly add, subtract, multip! and divide either whole numbers, dec. imals, fractions or mixed numbers. It solves rtion and gives roots, pow- ers, Sines, cnronte and Logs. The j| most versatile calculatorever invented. Made of Metal. Size 4". Price with Instruction Book, b EP vot Satisfaction guaranteed. Send for our Catalozue and Instructions in Logarithms and Trigonometry. Gilson Slide Rule Co. Niles, Mich. 136 Popular Science Monthly Taking the ‘‘Pop’’ Out of the Gas-Stove EARLY all gas-stoves will occa- sionally back-fire, or burn back in the opening where the gas is ad- mitted, and some stoves have the habit so badly that it is a positive nuisance. This can be cured, however, by inserting a piece of fine brass or copper wire gauze in the PIPE TO GAS STOVE BURNER pipe leading to the burner— between tap and burner. Cut a disk of the gauze and bend up the edges, making Fine wire gauze screening a screen that in the supply pipe will i 5 prevent the gas-stove from nie a nag J popping and back-firing one screen is not enough, put in two, half an inch apart. Automatic Shaft-Polishers Prevent Rust HAFTING in a _ machine-shop, which has been allowed to accumu- late rust through neglect, can be kept in a clean condition by the use of the polishers shown in the sketch. Cut out several disks of heavy card- board, felt or leather, and slip them on the shaft by spreading a = cut through Sk one side. They should be fairly ae loose so the CARDBOARD = shaft. will turn DISCS easily inside. With the shaft in mo- A set of these cardboard tion s disks on machine shafts : te _SHAPT . ; disks will travel will automatically clean the rust from them back and forth along its length and in a short time will clean the steel of its rust and keep it bright. Springy Cage Perches Make Healthy Canaries HEN birds hop from branch to branch it can always be noticed that the twig gives slightly to the weight of the bird. For this reason bird-cages should be provided with springy sticks. These are at- tached to a piece of wire which firmly loops the stick. The wire runs free for a short distance i behind the twig b efore it ig CAGE WiRES HEAVY WIRE twisted tightly How tomake « springy around a wire branch of the cage. In this case, as shown in the illustration, the stick must not rock from side to side.

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November, 1920 How Rubber Hose Improves Your Pliers OU can easily make all your pliers open automatically and stay open at all times by attaching a piece of rubber tubing or hose as shown in the illustration. It is found to be very useful for in- strument makers and electricians and at the same time it makes a soft handle In order to keep the plier jaws open, use a piece of rubber tubing to clamp over the handles. It also acts as a non- conductor of electricity and a non-conductive one where live wires are to be cut. It is much better than the metal spring which is attached to some pliers, as this gets caught in every- thing and is always in the way. To Keep Flower-Beds and Lawns Trimmed OME little time is required to edge and trim walks and flower-beds even if the person doing it is experi- enced. A gardener who had charge of a public park equipped’ his men with edging tools which he made himself. BUTCHER- “KNIFE WAeemacs 130988 pg _— ch pale 4 LRAE ‘lle Fi lk r YJ a LIM This little tool will help speed up your lawn work and keep the edges neat Wheels were procured from worn-out lawn-mowers, a hardwood stick four feet long, and a blade from an old carving-knife. The illustration shows how the trimmers were made. With this tool it is a simple matter to trim or edge a good many flower-beds in a very short time, as the tool is operated after the fashion of a garden hoe, and the oper- ator was able to walk along at a steady gait. In some instances it was found bet- ter to bend the bottom edge of the blades at right angles to cut the grass roots and sever the sod. ee ey TONN » \ " a : . % a” : ‘ ‘ 3 f 4 7 f «Some confab you had with What was he telling you?” the foreman. Ms what I knew already. I was using my Vernier Dept. doing real close work. “It was nothing new to me. The first foreman I ever had—back when I waé‘an apprentice—used to tell me Gage, and when he saw the Starrett mark on it, he started in telling me about Starrett Tools. How, when he was on the bench, he always used ’em, when he was id pRRe- W/o”? JA ACK SAWS the same thing. He’d been using them since the 80's. When I started to get a kit together, I bought Starrett Tools. Couldn’t do without °em. Simply have to have a Starrett for high-grade work.” “Sure. I never buy anything else either. And I always tell the kids in the shop to get Starrett Tools. Then they’re certain to have a kit When you want a tool of the with Starrett trade mar 21 W. Sent free on request. ey can depend on.” eatest accuracy, buy one Write for Catalog No. THE L. S. STARRETT CO. The World's Greatest Toolmakers Manufacturers of Hack Saws Unexcelled Big Profits Every Month in Battery Charging You Can Make $100 to $200 Clear Extra Profit Each Month This HB Outfit recharges 1 to 10 6-volt batteries at once for 10c to 15c each. Owner pays 75c to $2. Figure those profits! Youcan build a big, profitable business in battery charging. No electri knowiedge required. Small cash investment —long, easy terms—BIG PROFITS. | @ Small Cash Payment Puts This HB Outfit in Your Garage “ Balance on easy monthly terms. f easily carry payments. No expensive renewals—steady, dependable service, with BIG PROFiTS. Absolute money- back guarantee. Tear out this and mail today for information. Hobart Brothers Co., Box Sil2, Trey, 0. Suevesaful Manufacturers Since 1893 a Boxwood and Spring Jt. Rules ACCURATE Ask your dealer. - Ask us for Catalog No. 12 THE [UFKIN fPULe (0. x1. | > Price Includes Equipment as Shown in Illustration An 80- book, How to Run a Lathe mort onl 5 mgr ‘oe address for tencents, silver or stamps accepted. 187 ‘ South Bend Lathes For the Machine and Repair Shops 13” Lathe - $385.00 | 18” Lathe - $ 735.00 _ - 483.00 | 21” * =- 900.00 wt. - 550.00 | 24” * - 1250.00 Made with straight or gap bed South Bend Lathes are in use in manufacturing plants in 54 countries throughout the world. Est. 1906. Free catalog mailed on request. SOUTH BEND LATHE WORKS 433 E. Madison St., South Bend, Ind.

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ance mrenangpe ie eh nape The P Heat-Treatment of Drop-Forgings ACH grade of steel con- tains the possibility of a variety of physical condi- tions and, consequently, all steel forgings may be greatly modified in strength, tough- ness, or hardness by suitable heat- treatment. This process requires expert skill and special equipment. In Williams’ product, the grades of steel and its method of treatment are prescribed and controlled by a highly trained staff; some of the equipment, including the auto- matic furnace for treating quanti- ties of heavy parts, like auto axles and crankshafts, is shown above. Williams’ Superior Drop-Forgings and Drop-Forged Tools are supe- rior because scientific heat-treat- ment makes them dependable. J. H. WILLIAMS & CO. “The Drop-Forging People” BROOKLYN BUFFALO CHICAGO

7 RICHARDS St. 7 VULCAN Str. 1007 W. 120TH Sr. WILLIAMS’ “VULCAN” MACHINISTS’ | CLAMPS

Ask for Clamp Book

|

Popular Science Monthly Automatic Draft-Opener for the Furnace 1 ese the alarm By Thorton Hallett goes off in the dark- ness of a cold morning, why not have the furnace drafts automatically opened so that by the time you have had a couple of extra naps and finally get dressed the fire will be burning briskly and heat coming into the rooms? With the aid of a few odds and ends found about any work-bench | this can be accomplished, and part of _ the early morning labors abolished. It will first be necessary to take out the turn-damper in the smoke- pipe and fit in a longer axle that will project at least 5 in. from the side of the pipe. To this axle is then fitted the large sprocket of a bicycle, and a wooden drum or spool over that, slightly smaller in diameter than the sprocket. As the drum is to be wound with cord, be sure and provide flanges each side so the turns will not run _— LOOP—, FINE WIRE are ae a. Se TRIGGER “pad RELEASE TRRELEASE

MAGNETS

Here is the electrical apparatus attached to the alarm-clock which actuates the furnace damper off. Also arrange the damper to turn easily in the pipe and not bind. Next to construct is the electric release. This can be mounted upon a solid board nailed to the floor beams overhead and in line with the sprocket somewhat back of it as shown in diagram. Then cut out the trigger and release pieces of sheet steel or iron and pivot them to the baseboard so they will work freely. No dimensions are given herein, as the conditions will determine those to some extent, but the proportions should be some- what as indicated. Arrange the re- lease so the little projection will hold the trigger in an upright position when that bears against it. A small spiral spring also holds the release away from the magnets. The magnets can be secured from an electric bell or telegraph instrument and mounted upon the Dase so the poles will come about |< in. lower than the height of the projection on the release. 138 Two dry batteries can be strapped to the base directly under the magnets and wired to them as shown. Next, just back of this electric release, and in line with it, set up a single knife switch and connect the handle of it to the loop on the end of a bicycle chain which runs over the

You won’t have to start the furnace on a cold morning if you have this automatic draft-opener sprocket on the damper-turner. The other end of the chain is provided with a weight. The alarm-clock by which the damper arrangement is released can be situated anywhere in the house. Provide a second knife switch which works easily and fit it with an extra long handle. When the alarm un- winds, it lets the switch handle which was resting on it, drop into the poles of the switch below and this completes the circuit through the magnets on the release. The operation is simple. As the magnets are electrified, they draw the release down to them, which lets the weight on the chain pull the loop off the trigger and releases the hold. The weight carries down the chain, which in turn revolves the sprockets and the damper. When the damper has reached a position parallel with the pipe, it is held in that po-

= ELECTRIC RELEASE

SPROCKET AND PULLEY ATTAC TO DAMPER WEIGHT ON 7 CHAIN ——~ RN-DAM PERL S m CLOSE HPIT A AS DAMPER

/ DIAGRAM OF ARRANGEMENT CLOSED T ASH= CORD i DAMPER ‘TURN-DAMPER

The sprocket wheel and weight which turn the furnace damper are here illus- trated in detail

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November, 1920 sition by the cord attached to the chain and the knife switch back of the release. The pull on. the cord opens the switch and breaks the circuit through the magnets, thus saving the power of the batteries. The length of the cord and the handle of the knife switch should be such as to determine just where the chain is to be stopped so as to bring the damper in the right position. The ashpit damper can also be opened at the same time by leading a stout cord wound about the wooden drum and leading it. over the heater to a pulley a little forward of the pit door as shown. When the sprocket revolves, it will wind up the cord and lift the damper. The particular make and operation of the heater you are using will determine the exact position of the separate parts, but by a little figuring they can be arranged to operate the dampers as described. ° Suggestions for Economy on the Automobile HEN the brakes squeak it is usually due to dirt forced into the lining fabric when pressed against the drum. Often this dirt can be washed out with kerosene. When the lining is thoroughly im- pregnated with dirt, however, kerosene will not prove adequate. In these cases, a small amount of rosin and castor-oil mixed as a fluid and applied to the brake-bands will put an end to the noise. A crack in a cast-iron pipe or a cylinder jacket can be repaired in the following manner, without a great deal of trouble, if the pressure the part has to withstand is not too great: Dissolve some sulphate of copper in water, and after cleaning the edges of the crack well with a file or sand- paper, paint these edges with the sulphate solution several times until there is a coat of copper on them. The crack can now be filled with soft solder, which will adhere to the cop- pered edges. There is a good chance of the cur- tains mildewing if folded and packed away when they are damp. It takes but a few minutes longer to dry them thoroughly before stowing them away, and the assurance of their keeping in good condition is worth these extra minutes. As an amplification of the hairpin idea, every automobilist’s tool-kit should include a spool or roll of small- diameter soft iron wire. This has a multitude of uses in and about an automobile. You know how handy the little wire hairpin is when some- thing goes wrong on the road that only a piece of wire will fix temporarily. But very often this famous pin is not long -enough. Better to have the spool of wire and never use it than to get stalled when a length of pliable wire would prevent it. ies BRHUREDDA ARE RAOitOE y SIMONDS INSERTED TOOTH METAL SAW cutting 12''x 12" unannealed die block at rate of 1"" in 144 min. or 12” in 18 min. SIMONDS SAWS cut metals just as infallibly as they cut wood. Not so fast, of course, but just as steadily and truly. There is a SIMONDS Saw ‘for every purpose. And the soul of each is SIMONDS STEEL. Simonds Manufacturing Co. “‘The Saw Makers” Established 1832. Fitchburg, - ‘- Massachusetts New York Memphis Montreal San Francisco New Orleans Chicago Portland, Ore. Seattle Lockport, N. Y. London, Eng. Vancouver, B. C. St. John, N. B. SAW STEEL PRODUCTS ||. MADE RIGHT SINCE 1832 SIMON 139 DS SG ee RR DERE aa SSE SSS a PRE EE — oe mee 3 mato e Si 2s -

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Popular Science Monthly An Easily Installed Burglar Alarm for the Home N these days, when our daily papers By Mortimer V. Tessier in place by the use of the staples, they will are so full of the activities of the | be practically unseen except where house-breaker, many will be interested, | they cross the wall from the baseboard no doubt, in anything that will insure | their home against a visitor of this | kind. Nothing will drive a burglar away quicker than an unusual noise of any kind while he is at work. For this reason the contrivance here described should be of special interest, for it can be wired into the line of your front- door bell and the moment Mr. House- breaker attempts to open a door or window, your front-door bell will start ringing and continue to ring until the door or window is again closed. It can be installed easily without the aid of an experienced electrician and all you will require is a_ sufficient quantity of small cotton-wound wire, a cheap, single-pole throw-off switch, some sheet brass (not very thick), and a quantity of small wire staples to run the wires with. Also two dry- battery cells for the burglar alarm. How to Install the Alarm Cut from the sheet brass, which should be about the thickness of heavy tin, so that it may be easily cut and shaped with the shears, one spring, as shown in Fig. 2, for each door and two springs, as shown in Fig. 1, for each window. The springs for the windows should be turned in opposite

FIG. 1 FIG, 2 The details of the general wiring plan for the homemade burglar-alarm system directions, as they are to be placed on opposite sides on the top of the lower sash, as shown in Fig. 1. After you have made enough of these springs to equip all the win- dows and doors on the ground floor of your home, you are ready to begin the installation of the line. The wire used for this contrivance should be small, single strand, cotton-covered copper wire. If it is covered with some material that will match the paper or woodwork, the wires will be much less conspicuous and can be placed so that very little can be seen of them. Figure 3 will give a plan for the wiring of the alarm. If the two wires required in the line are placed along the top of the baseboard and a loop brought up at each window or door along the outside of the casing and brought down on the other side to the main line, drawn tight, and held 140

to the window-casing. The wiring for the windows is as follows: Place one of the springs for the window (Fig. 2) on each side of the top of the lower sash, and connect

a, fRONT-DOOR WINDOW 4“ WINDOW BELL YY ‘“s - 4 DOOR TriROW-OFF SWITCH {1|t BATTERIES FIG. 3 The circuit is made or broken by means of springs when the door or window is opened the two springs with a wire running along the top of the sash by winding the bared end of the wire once around one of the wire nails with which you fasten the spring in place. These springs should be so placed that they bear lightly on the face of the sash strips at the sides. Run a length of the bared wire down the face of the sash strip to with- in about half an inch of the top of the lower sash, taking care that it is in the track of the spring, which will slide up and down the sash strip as the sash is raised or lowered. Fasten this wire down with staples at intervals and turn the end of the wire into the wood at the lower end. Now carry the upper ends of these wires out over the casing at the top of the window and down along the outer edge to the base- board, using the staples at intervals. Care should be taken that you do not connect both of these wires to a single wire at the baseboard. Each should connect to a separate wire on the main line. The doors are wired in the same way as the windows, using the spring shown in Fig. 2 in the manner de- scribed. The main-line wires may be carried all around the casing of the door and the connection made across the corner as shown, placing the spring so that it will bear lightly on the top edge of the door when it is opened. Fasten the bare end of a short length of wire over the edge of the door in such a position that when the door is opened it will connect with the spring. Bring this wire across the corner of the door and to the hinge. Lift the upper screw of the hinge out a couple of turns and wind the bare end of the wire once around, and drive home again. Repeat this opera- tion with the other side of the hinge on the door-casing, using another short-length wire, and, carrying it over the casing, connect with the other wire in the main line. Repeat this programme with all the doors and windows on the ground floor, and finish by hooking in the dry cells and

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November, 1920 connecting it with the front-door bell, breaking the line at some easily accessi- ble place, and install the throw-off switch. Thisis very necessary for use in the daytime, so that then you may throw off the alarm completely. To Splice a Clothesline Strongly and Easily HEN several sections of a clothesline have to be connected, or when a broken section has’ to be repaired, here is a simple way to do it that will prove strong: Cut off the end of the line clean and bind each one with several turns of tightly wound twine. Then punch a hole through the center of the line about 34 a steetbelt-hook will hold in. from the the broken line securely end and drive a steel belt-hook through these two holes, connecting the ends of the lines. By pinching the legs of the hook over on the under side of the line a solid repair is made. Lines can be quickly disconnected by twisting one at right angles to the other and pulling the hook out. To Balance Ornaments that Are Top-Heavy E are constantly upsetting top- heavy ornaments, lamps, pedes- tals, etc. A great many of these acci- dents can be remedied easily, if the bases on which these lamps or orna- ments rest are ELECTRIC made heavier. Phe may be done in many different ways and does not re- quire exception- al skill. The method of weighting such ornaments depends, of us Gale A course, on the RECESSED) material of which they are a made. If made serting melted lead of wood, bore holes in the base from the bottom, and with a chisel cut out the wood between the holes so as to join them. At intervals cut three or four shoul- ders for locking. With lead melted just enough to run freely, fill the exca- vation. Be sure the base is level (up- side down) and guard against the lead being too hot, as it will burn the wood. It is better not to fill to the top with the melted lead; and if there are any high places after it is set, use a cold chisel or file to reducethem. Itis best to cover the base by gluing on felt to prevent scratching. Cut Wood Lichining Fast Saws 60 to 70 Cords a Day Saw your winter’s wood supply in a few hours! This newly invented, Portable Buzz Saw does the trick. It’s a BIG MONEY MAKER and a wonderful WORK SAVER to any Woodsman or Farmer. Pro- vide wood for needed fuel for your neighbors at high prices. Coal shortage is boosting wood prices. Many users are averaging $15 profit per day of easy work. Light Weight Easy to Move Anywhere: ©23¥,° es | Asigag A Woman or Boy every day in the year—in all weather. Cuts wood faster than [@u@)yYoricome heavy, old style saw rigs. Costs less than 4%. Motor runs belt machinery—feed grinder, cream separator, washing machine, etc., when not sawing wood. This most practical development of a low cost buzz saw ever invented. It’sa big surprise! The work it does opens your eyes. The money it saves you will make you a booster, TTAW. The Newly Invented A a. Sawing Machine WW ~ / was», BUZZ SAW fee Cords a Day hd) peemmmmmmmmeees TT Pump Jack : ulls over 3 H. P. 4-Cycle Frost-Proof Engine, 225° with Gscit lating Magneto. No batteries; starts without cranking. Extra heavy saw mandrel; balance wheel; belt tightener. Has saw guard that protects operator. 20-inch tested steel circular saw. Bronze fuel mixer uses low grade fuel. Entire machine is made to give dependable service for years. Nothing to get out of order. Comes to you all ready for work. 9 . Try the Ottawa Buzz Saw for a full 30 Days Tr ial: math. Let it prove that it saws faster and at lower cost than any other outfit invented. Pay for the outfit out of your profits. 10-year Guarantee backs each and every machine. Workmanship and Material the very best. Use coupon below and send at once for book Free Book: telling at about this wonderful buzz saw— what it will do and what it is doing for others. Special Limited Introductory Offer is yours if you ACT AT ONCE. OTTAWA MFG. CO. 872 Main St., Ottawa, Kans. ns Ai Hy ai \\\ ; ie : AX \ LE BF sPECIAL OFFER §f ae OTTAWA MFG. CO. 4 872 Main St., Ottawa, Kansas Piease send me Free Book and Special a Offer on Ottawa Buzz Saw. IS oo ors isiie hinatens Conia ebm s Sb weteae ee ee ee ee 141 2NN Pictures of Inventions and Discoveries i Be { i sp — =

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p pur gre Jt New Discoveries in Your Machine In the most familiar and fin- ished machine there are new things to be discovered— new powers of production, new efficiencies in adjust- ment, new responses to operating methods. You make these discoveries by watching the production-record; you see the causes which register increased output or a better production-rate. Summed up on the dial of a COUNTER are the results of your manage- ment of your machine; the record is made as the machine runs—showing you what is happening as it happens. The above Revolution Set-Back Counter records the output of any machine where a shaft-revolution indicates an opera- tion. Sets back to zero from any figure by turning knob once round. Supplied with from four to ten figure-wheels, as required. Price with four figures, as illustrated, $10.00 —subject to discount. Cut less than 4 size. The Number 14 Ratchet Counter at left registers one for each throw of the lever, recording } number of machine- operations. Sup- plied with outside stops which regu- late the throw of the lever, and having return spring action which automatically returns the lever into position for the next count. The lever is adjustable, allowing the counter to be used at any angle. Price, $2:25. Cut nearly full size. Most any machine you're inter- ested in can be equipped with a Veeder Counter; write for booklet illustrating complete line. The Veeder Mfg. Co., 44 Sargeant St., Hartford, Conn. is usually busy washing cars and fails to pay im- mediate atten- tion to the re- quest. A method of calling the at- tendant auto- matically is shown in the il- lustration. If desired, the de- vice can be ar- GARAGE Aalslalals HH BURIED COILS Popular Science Monthly A Simple Automatic Signal for Garages By Thomas W. Benson ESIDENTS near public garages are often annoyed by motorists blowing their horns late at night when seeking admittance, and the night man during the day. The other two coils are connected to a relay similar in construction to an alternating-current voltmeter with the exception that the pointer is ar- ranged to close two contacts when it moves. ° This alternat- ing-current relay may control a bell or other sig- naling device placed in the rear of the gar- age. Ora second relay may be connected in the COILS IN BUILDING A.C.RELAY ranged to open the doors as welli. It is but another application of the well-known Hughes’ induc- tion balance, a device of a thousand uses. Two coils, alike in every detail, are buried in the ground directly in front of the garage door. These coils are carefully waterproofed and have sepa- rate leads running back into the garage. Here two similar coils are mounted. One coil of each pair is connected to the lighting mains through a switch that is used to disconnect the device a SWITCH (3 LIGHTING-MAINS Running the car over the buried coils throws them out of balance and rings a bell for the garage attendant TO BELL OR RELAY CONTROLLING MOTOR circuit to control a motor to open the garage doors. The operation of the device is practically _ self evident. The coils are so connected that the currents induced in them balance, thus the alter- nating-current relay will remain open. However, when a car drives over the buried coils, the balance will be de- stroyed and the first relay will close. In this manner a signal will be given or the door opened as arranged. A device like this is eminently practical and convenient. A Special Surface-Gage Pointer By H. H. Parker HE sketch illustrates a fine ad- justment attachment to a:surface gage when a direct longitudinal move- ment of the pointer is required. It is intended to fit into the regular clamp | body in place of the regular needle and consists of a steel sleeve the diameter STEEL TUBE , SAME DIAMETER AS REGULAR AA Cerri tttet (or THREADED AT END FINE ADJUSTMENT LOCKNUT QUICK ADJUSTMENT HANDLE The illustration shows the sleeve and pointer. The locknut only secures the handle and does not lock the pointer of the original needle, made either of small sized tubing or of a piece of rod drilled out with a long drill of small diameter and then turned on the out- side to the pointer diameter. The sleeve is threaded inside with a fine thread for a short distance at one end; the walls of the sleeve must be left thick enough for the purpose. Then a pointer is made up to a snug 142 fit into the sleeve; one end is left large enough to be threaded as ~ shown. Drill 10d is probably the best material for the pointer. A small flat nut anda longer one of smaller diameter are made up, the edges knurled and both threaded to fit the pointer. The flat nut acts as a locknut to hold the other one, and also as a slow-speed adjusting nut, while the longer one acts as a high-speed adjustment. Scratch the Match on Your Pocket-Knife HE three most essential require- ments of the smoker are, first, something to smoke; second, a match;. and, lastly, some place to scratch the match. As nearly all smokers carry a pocket-knife, the difficulty may be overcome by placing the knife in a vise and with a hard file make a series of notches across the back of the knife (as shown in the illustration). These notches need not be very deep, as the quantity counts more than the depth of the indentations.— MORTIMER TESSIER. SSSSS AR Ww aa See TAA As i} Te VES VE ALBA RAR Notch the back of your knife and you will always have a match-scratcher aa