Popular Science Monthly 1915-10: Vol 87 Iss 4

Page 1

ELECTRICITY MECHANICS INVENTION SCIENCE aaa A i

Page 2

t ¢ ae SR 4 ; %, Fae RECSRDS ECAUSE the tone offiginstrument depends al- most as much upon the original recording process in the record-making as on the reproducing mechanism of the instrument itself, Columbia Double-Disc Records, played on any instrument, are indeed a tone revelation to most people. Once you have played a Columbia Record on your instru- ment, we believe you will never again be satisfied with a tone any less round and rich and natural. A talking-machine record i is the only article of merchandise in the world that literally “‘speaks for itself.” Hear one Col- umbia Record and wc have told our story. (B COLUMBIA GRAPHOPHONE. CO. y Box J493, Woolworth Bldg., N. Y. This model Columbia Grafonola with individual record ejectors$110 with ordinary record racks $100

Page 3

-POPULAR SCIENCE MONTHLY and WORLD'S ADVANCE or ELECTRICITY CONDENSED COURSE ELECTRICAL ENGINEERING Completein OneYear Bliss Electrical School Studies restricted to theoretical and practi- cal electricity, mechanical drawing and nec- essary engineering knowledge. Actual construction of apparatus, installation and testing right in the school. Teaches concentra- tion and hard work. 23rd year opens Sept. 22nd. Write for new catalog E. Special 6 months Evening Course in “Wire and Wireless Operating” opens November 15th, 1915 EXCEPTIONAL OPPORTUNITY to qualify as a FIRST CLASS preg sapere am OPERATOR Write for catalog W 100 TAKOMA AVENUE Practical Electrical Education 122 ans san fic methods, under practi- eal working conditions, all branches of Electrical Science and Engineering. No matter what your present education is, we start you at the point where you can easily grasp the study. By our system of practical individual instruc- tion you ean complete the course as quickly as your ability warrants.. TRAINED ELECTRICIANS ARE IN GREAT DEMAND. This school, the only one of its kind in the U. S., is highly endorsed by leading electrical employers in U. 8S. and other countries. Our trained students are eagerly sought for and are well paid. The Electrical field offers the greatest number of highly paid opportunities for ambitious men. Students may enter at any time Write for FREE Illustrated catalog and terms. School of Engineering of Milwaukee 221 Stroh Building Milwaukee, Wis. WASHINGTON, D. C. LEARN IN 3 MONTHS TO EARN $1300 TO $4000 A YEAR MECHANICAL DENTISTS DO IT—the demand is years ahead of the supply. Any man or woman can learn, no previous schooling or entrance examinations required. PROF. BODEE, the most ingenious and thorough mechani- cal dentist in America, instructs each student personally. The first and only school recognized by the Dental Profes- sion. Not a correspondence school. Practical individual in- struction on actual cases in our large laboratory; no book study. Tuition payable in moderate monthly installments; we assist you to positions. Students received at any date. WRITE TODAY FOR CATALOG B. FILMS DEVELOPED By my process give best results. Over twenty years’ experience WHY experiment with failures? One 6x roll developed free. Booklet ‘Film Faults.” Sample Velox Print free. Cc. V. POLLARD, Lynn, Mass. EARN TELEGRAPH Morse and Wireless—R. R. Accounting (Sta- tion Agency) taught. Splendid opportunities. Positions secured. Marconi Co. takes our wire- less graduates. We own and exclusiveiy ed 46 yea ailroad, ‘Marcon and Western Union Ee piecton teachers. Low living expenses; easily earned i nas ber Tuition low. ney a. Corre- spondence courses talogs Dodge's, Telegraph, Ry. & Wireless 1 Instituta 2ist Street, Valparaiso, ind. earn Electricity earn Plumbing earn Bricklaying Unlimited possibilities for gaining wealth and future independence in all of these trades. They pay $5 to $8a day right from the start and any one of them offers exceptional opportunities for starting a business of your own on very small capital. The same is true of Mechanical Drawing and Moving Picture Operating Two new, big-paying occupations that are now demanding more and more trained men everywhere. You canearn $100 to $250 a MONTH We give you thorough, practical training —no needless theory—you learn with ac- tual tools in your own hands under expert instruction instead of from books. No ex- perience and no special education re- quired. Just a willingness to learn and we'll make you an expert in a surprising- ly short time. You can enter at any time. The ages of our students are from 15 to MEN WANTED right now for all of these trades. That’s why we are now making special induce- ments in the way of a very small tuition on easy payments if you like, agree to assist you in earning your way through school and also help to place you in a good paying position when you graduate. At this biggest and most successful of all trade schools everything has been arranged for the benefit and convenience of our students. Day or night classes as you prefer, and we even furnish as well as all other neces- Tools Free sary equipment for your work Mail Coupon NOW! Don’t put it off. This is a matter of vital importance to you. Get full particu- lars of the wonderful opportunities this re- markable school affords. No obligation— everything free. Mail coupon today while our Special Offer is still open. easy it is te become a “Coyne Success” WE OCCUPY ENTIRE BUILDING Tear off, fill out and mail = ee = om B. W. Coo! Director, Coyne National Trade Schoo! 39-51 ES Winois St!, Dept. 1407, Chicago, Ill. Gentlemen: Without any obligations on me whatsoever, onag send m me your school catalog and full particulars of this offer to anne Sy When writing to Advertisers please mention Popular Science Monthly and World’s Advance.

Page 4

PULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Volume LXXXVII Contents for Gaisher 1915 Fage Aeroplane Secured by National Guard and Naval Militia ....c.ccccccccccscccee sient Animals that Cure Men’s Ills An “All-Electric” Village tad Coal with Water in German tees. A Buried Garbage Can Opencd by the Foot.. Carefully Made Champagne Bottle, The Chance for the American Motor Maker in China, A Cleaning Four and a Half Miles of Water Main with an Internal Scraper Composing Music with the Aid of a Wax Phonograph Record Concrete Piles and a New Way of Sinking Them Converting a Street Car into a Stationary Re- pair Shep A Craftsman Desk Table Dyeing Silk Before it is Silk Electric Power from Thunder Clouds Electrical Resistance as a Cr:terion of Health.. 503 Electricity Direct from Coal Evolution of the Self-Starter, The Fighting the Menace of Shifting Sands Fishing Boat Hauled by a Motorcycle, A Fishing a Ten Thousand Dollar Locomotive Floating Metals Forcing Plant Growth by Acetylene Forty-Five Pound Miniature Motorcycle, A.... From Albany to the Panama-Pacific Exposi- tion on a Motorcycle Furka Railway of Switzerland, The Growing Mutton by Electric Light Land Yacht and its Transcontinental Voyage, A Home Craftsman, The How Ammonia is Made How Electrolytic Action Destroyed a Yacht.... How German Bread Laws Inspired an In- How Smoky is the Air? An Instrument that Tells Jail on Wheels, A Latest Galveston Hurricane, The Lightning Rod Comes Back, The Machine Gun—the War’s Greatest Terror, The. 459 Man-Made Limbs for Limbless Men Man Who Built a Round House for Himself, A. 450 Measuring Telephone Talk.: Minimizing Eyestrain at the Movies Mobile Motion Picture Studio, A Mudguard Lights to Show the Width of an Automobile Mysterious Zone of Silence Observed in Test- ing Distances Big War Guns Can be Heard.. 462 Necessary Poison, A New Discovery About Shaving Soap, A New Fashions in Furniture Casters New Food from the Sea, A New Tasks for the Automobile New Type of Detachable Motor for Rowboats ee ee eee coescocccccce 449 Non-Blinding Automobile Headlight, A......... 406 Oil Worth $1,200 a Barrel Panama-Pacific Exposition Notes ..........ses+. 497 Peace Fleets of the United States......... eocces Mee Photographing a Bullet in Flight cvcoe M4 Plant that Made a Seat Out of a Millstone, A.. 455 Poisonous Submarine, A ; “The Portmanteau’”—a Theatre that Travels with its Actors Providing a Torpedo with Ears...... Smanwlew sioiye Questions and Answers ccccccdece Sad Radium in the Air We eatin, Railway Lunch Counter for Golfers............ Real Cost of a College Education, The Reconstructing Facial Features from the Skull. 481 Rendering a Bank Safe Burglar Proof Return of Natural Indigo—One Effect of the War Saw Mills in City Streets Short-Lived Pin, The Sign that Renders your Car Proof Against Space Saving Table, A Sprinkling Cart that Carries its Own Pump, A. 450 Surprise Signals to Test Locomotive Engi- Taking an Imaginary Submarine Trip at the Panama-Pacific Exposition Teaching Office Boys their Job Telephones on Fighting Aeroplanes to Talk Over Three Feet Tobacco in Convenient Cartridge Form Tower that Fools the Eye, A (Continued on page 8.) Copyright, 1915, by The Modern Publishing Co.

Page 5

AND POPULAR SCIENCE MONTHLY bh f WORLD’S ADVANCE Vol. 87. October, 1915 No. 4 AND Wor.Lp’s ADVANCE. ADVANCE will present to its readers the new, the prac- tical, and the unusual in modern science, mechanics, J and electricity. It will strive to be a fascinatingly inter- : esting, easily grasped, and trustworthy monthly record dustry. most varied kind. Waldemar All the features of the WorLp’s eis which have proved most popular will be retained. Wireless ama- teurs may turn to the “Radio Section” and know that they are receiving the latest wireless news and the best practical information on wireless. who have profited by the “‘Practical Worker” “Home Craftsman” departments will continue to re- ceive helpful suggestions for the making of useful ar- ticles. All these departments will henceforth be edited by the most competent men obtainable. will be more useful and stimulating than ever. The Porutar ScrencE MontTHity AND Wor.p’s as in the past, In fact, they of the latest achievements in science, invention and in- The November issue will contain over 140 pages of illustrated articles and three hundred pictures of the Contributions from our readers are solicited by your new Editor and by the new publishers. paid for at regular rates on acceptance, 401.910.3472 They will be Two Important Events for the W orld’s Advance ITH this issue the Wortp’s ADVANCE and the PopuLAR SCIENCE Monru ty, founded in 1872, the oldest monthly in America devoted to the popularization of science, are combined. Beginning with the November issue, | Kaempffert—perhaps the best known writer of popular science subjects in America, and for the past fifteen years Managing Editor for the Scientific American— becomes the Editor of the PopuLar ScreNcE MontTHLY CE a NR fe ered | | i

Page 6

} § , HANKS to modern science, animals are not merely beasts of burden or purveyors of pelts. Although it is not generally known, animals have been of peculiar service in assisting man to prevent and combat disease and to overcome the effects of poisons. Even the dreaded poisonous snake has become the means of saving many thous- ands of persons yearly from death due to snake bites. Through the great ad- vancement in the knowledge of antiveno- mous serum-therapeutics in the last few years it is now possible to overcome the effects of venomous snake bites through the injection of antivenomous serum into the snake’s victim. Certain snakes thrive in captivity while others refuse food and are kept alive with difficulty. A snake that refuses food must be artificially fed, and it is not possible to obtain as much venom from such a one as it is from one that will eat of its own volition. The snake pic- ture at the head of this page is one of those which take kindly to captivity. It is a moceasin snake that has been in the Reptile House in the Bronx Park Zodlogical Gardens for several years. When the venom is to be extracted the The method of holding an enraged snake in order to secure its venom. A glass tumbler is covered over with sterilized gauze in which the 402 Animals that Cure Men’s Ills snake sinks its fangs. By A. M. Jungmann snake is taken from its cage, thrown upon the floor and, before it has had time to strike, a cane is held over the back of its neck. It is then seized firmly just behind the head while the body and tail are held under the arm. The snake is now thoroughly enraged and ready to strike. It is offered a glass tumbler covered with absorbent gauze, and into this it sinks its fangs with a vengeance. As soon as the snake takes hold of the glass the poison glands are gently pressed and all the venom they contain is forced out. The snake yields between thirty and forty drops of venom. Extracting venom from poisonous snakes requires coolness and skill, but Mr. Charles E. Snyder who held the snake shown, re- gards it as all in the day’s work. It would be possible for this moccasin to yield twenty-eight ounces of venom if it were extracted once a week and the average yield were 35 drops, because a moccasin is expected to live about seven years in captivity. Antivenomous serum is obtained from horses. The horse is vaccinated with the snake venom, beginning with a very small amount and gradually increasing the amounts over a period of sixteen months.

Page 7

. <a wack om he all he as.

The serum is sufficiently antitoxic when the horse will tolerate 2 grammes of dry venom in a single injection. Dr. Cal- mette has been very successful in prepar- ing serum from cobra venom in this manner. Twelve days after the last in- jection of venom the horse is ready to be bled. In a space of ten days he will give 20 litres of blood. Then, after a three months’ rest, the animal is ready to have the operation repeated. The horse has been of the greatest service to man in furnishing sera. Not only has this animal been the means of giving us antivenomous serum, but he has provided sera for use in combating tetanus and diphtheria. As an example of how efficient a horse can be in this re- spect, consider the horse shown in one of the illustrations. He is known as Old Faithful. After having served an ordinary lifetime of labor in the employ of New York city LE he was condemned and sent to Otisville, where the city main- tains a laboratory for the production of sera. This horse being found to be in excellent health, although too old to con- tinue the work he had been accustomed to doing and therefore considered value- less in a monetary way, was sent to the laboratory. To date he has given the City of New York $175,000 worth of diphtheria antitoxin. . Diphtheria antitoxin is produced by taking a virulent culture and growing it

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 403 in broth for a week. The culture, after rigid tests for purity, is rendered sterile by the addition of 10 per cent. of a 5 per cent. solution of carbolic acid. In 48 hours the dead bacilli will have settled on the bottom of the container and the clear fluid is filtered off and kept in a cool place until required. Horses are then injected with enough of this toxin to kill five thousand guinea pigs. From three to five days afterwards a sec- ond injection is given the horse. At intervals of from five to eight days there- after pure toxin is injected until at the end of two months the dose has been in- creased from ten to twenty times. After six weeks or two months from the. first injection the horses are bled and their

Above: A sheep will yield, on an average, three ounces of blood twice a week. his blood is large- ly employed in the well-known Wasserman test. At the Left: Obtaining the seed virus from a rabbit.

serum tested. Horses that are found to give less than the desired number of units per cubic centimeter are discarded. The horses which are retained receive in- creasing doses on an average of from three days to one week. At the end of three months the antitoxin serum of the horses should contain over 300 units per cubic centimeter. Some horses have been known to give over 1000 units, but none has been known to give as much as 2000 units per cubic centimeter. At in-

Page 8

404 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE tervals of every nine months the horses are given a three months’ vaca- tion, during which time no inoculations of any kind are given. In this way the horses are kept in good condi- tion. The strength of the antitoxin necessary seed virus. The calf which is to be inocu- lated is first thorough- ly cleaned and its hair clipped. The calfshould be from two to four months of age and pre- ferably a_ fe- male. Before vaccination the calf is thrown on a table and “ Th h the part played by a calf it is possible to procure - : is tested on sufficient vaccine from a single animal to vaccinate 15,000 its posterior guinea p i gs. people, with the original material secured from five children. agbdomen and For example, when ten fatal doses of toxin are mixed with one-tenth of the amount of anti- toxin used with 100 fatal doses, the guinea pig will remain in its normal state of health. The service of the calf to man does not end with giving him leather and veal. The calf has been of inestimable vaiue in combating smallpox. In preparing smallpox vaccine five children who have never been vaccinated are vaccinated in the usual way. Five days after vaccina- tion the top of the vesicle, or scar, is removed and the base is rubbed with sterilized bone slips. Each child will serve to charge both sides of from one hun- dred to two hundred _ slips. The slips are then placed in a sterilized box and kept in cold storage. They will re- tain their use- fulness for from two to three weeks. This is known as _ obtaining seed virus. Rabbits are also used for obtaining the s F : J This is Old Faithful, a horse that has already given the City of New York over $175,000 worth of diphtheria antitoxin. the insides of its thighs carefully washed and sterilized. About one hundred scarifications are then made on the sterilized area. The vacci- nated places are from one-quarter to one- half of a square inch. Each scarification, or place wherein the vaccine is to be rubbed, should be separated from an- other by about three-quarters of an inch. On the fifth or sixth day from the time the calf was vaccinated the vaccine vesi- cles should be ready for collection. The vaccinated area is again thoroughly steri- lized and the crusts are picked off. The remaining pulp is then removed with a curette and made into an emulsion, which is placed in vials. Ivory slips are also charged from the vesicles. The _ mate- rials collected from the origi- nal five chil- dren may be sufficient to vaccinate fi f- teen calves Ten grammes of pulp and ‘two hundred charged _ slips may be ob- tained from Tay * “ee , Ss PD AA

Page 9

each calf. five children, enough vaccine should be produced to vaccinate fifteen hundred In short; from the original persons. One calf has been known to yield sufficient vaccine to vaccinate ten thousand persons. It has been found that when an animal is subjected to repeated injections with red blood cells of another species it will produce substances in its serum which will dissolve the foreign blood cells. Wasserman used this principle in his famous “Wasserman test.” For this pur- POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 405 pose a sheep is used. A sheep will yield, on an average, three ounces of blood twice a week for about two years. All the animals used for these purposes are given the best of care, for they must be in excellent physical condition. Every effort is made to accomplish the opera- tions painlessly. It is safe to assume that many an animal suffers more physical discomfort because it is improperly cared for in the ordinary pursuits than do the animals used in laboratories for the pro- duction of sera. A Poisonous Submarine The United States Patent Office re- cently granted a‘ patent to Carl N. Wheaton for an invention which it pro- saically calls “means for conducting sub- marine warfare,” but which is in truth an extraordinary revelation of the pos- sibilities of the human imagination run riot. Torpedoes were apparently too harm- less for this inventor. So he conceived the idea of asphyxiating the entire crew Not satisfied with the deadly efficiency of modern torpedoes as used by submarine boats, an inventor has suggested a = of using a gun to shoot asphyxiate ison gases into the hulls of hostile warships. The plan is to e crew of the warship without causing any material damage. But is the suggestion : practicable ?

Page 10

Eos — Salpeter 406 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE of a battleship. He was not inspired by the use of chlorine gas in the present war; for according to his patent papers he filed his application over eight years ago. It is his idea to bring a submarine directly beneath the battleship and drive a hollow pin or projectile right through her bottom. Through the bore of the projectile a deadly gas is to be poured. He suggests, too, that a timed bomb can be attached to the head of the projectile, which is made separable so that the sub- marine can retire and watch results. No naval officer would take this inven- tion seriously, In time of war, fleets of battleships are carefully guarded by whole chains of submarine mines and cordons of torpedo boats. There is no chance for a submarine captain to glue himself to the bottom of a battleship. And on the high seas the feat would be still more difficult. Once it dives below the surface a submarine is blind; its peri- scope is retracted and it cannot see. What is more, the speed of a submarine on the surface is about twelve knots and the speed of a modern battleship any- where from twenty to twenty-five knots. The submarine would be in a position of a snail trying to bite a greyhound. A Non-Blinding Automobile Headlight Headlight dimming or controlling de- vices have appeared in considerable num- ber recently, but few have succeeded in passing the official tests of the Board of Headlight Inspection of Maryland, which has taken, up the question of highway protection in a vigorous manner. One of the latest to receive the approval of the Board is the fnon-blinding device illustrated herewith. Uninterrupted passage of the rays of light is permitted only when they are horizontal. All rays reflected in an up- ward direction are caught by the tilted section of the “lattice work,” reflected first downward and then outward in a horizontal direction. A few rays are per- mitted to escape downward, directly in phacenanea iets ey BROKEN Away TO | CONSTRUCTION, ie The glare of any automobile headlight can be climin- ated by using a simple device consisiing of con- centric metal strips. front of the car, where they increase the light thrown on the road. Not a single ray can blind the eye of a pedestrian or driver in an approaching car. The device consists of a series of con- centric rings, made of metal and covered with the usual mirror silvering. It is placed in the headlight back of the glass, being protected from dirt and dust. Electric Power from Thunder-Clouds Ever since men knew these two things —that the energy displayed in a thunder- storm is electric, and that electricity may be utilized—they have wondered if there was no way of preventing so much power from going to waste. Occasionally a bold inventor tries to harness the storm as we have already harnessed the cata- ract. His task is similar to that of util- izing the energy of the gunpowder ex- ploded in a battle. The energy is there, but the problem is to control it. We need a motor that will run with a current of high intensity and small volume. Such a motor, it appears, is that in- vented by a Russian, N. P. Michkine. Whether he has entirely solved the prob- lem is, of course, another question. The quantity of electricity stored in the atmosphere may be estimated by the effects sometimes produced by lightning. ge fr fF A fF wee

Page 11

tiene ge But clouds that carry electric charges are only, so to speak, greater centers of ac- cumulation for the electricity which in ordinary weather is spread throughout the atmosphere. We know that electric discharges also manifest themselves by heat effects. . There are numerous cases of telegraph wires melted by lightning. At the mete- orological observatory of Pavlovsk, Rus- sia, when a balloon was about to be re- leased, an electric discharge, passing from a cloud to the earth, completely volatilized a steel wire one-thirtieth of an inch in diameter, that held it. The remarkable thing was that the atmos- pheric state indicated only a slight ten- dency toward the production of a thun- der-storm. Experiments in similar conditions, made by Kohlrausch, a German physic- ist, show that at the moment of a light- ning discharge a copper conductor one- fifth of an inch in diameter may be melted. Now Michkine has used these data to calculate the quantity of energy con- tained in a cloud, and has concluded that it amounts to at least enough to run an eight and one-half horse power motor for one hour. Hence, if we could utilize the energy wasted in a thunder-storm— energy that probably exists in the atmos- phere at other times also—we should have a most valuable source of power. Although its energy is great, the elec- tricity in a cloud possesses this energy largely by virtue of its high tension, for the actual volume of current in a dis- charge is small, just as the energy of a rifle bullet is due more to its velocity than to the small mass of lead compos- ing it. If we are to utilize the energy of atmospheric electricity, therefore, we must have a motor that will work with a small volume of current. This motor Michkine believes he has invented. The world’s copper production amounted to 893,085 tons last year, most of which is consumed by the electrical industry. A large amount of the copper production has been utilized in the mak- ing of ammunition for the fighting na- tions. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 407 Concrete Piles and a New Way of Sinking Them Concrete has for many years been steadily usurping the place of wood in numerous forms of construction. One of the uses to which this versatile mate- rial has been put is in the concrete pile. An exceedingly successful concrete ————EEEEE aes ea———S A sectional view of a new pile of novel design. The not only protects the con also acts as the reinforc sunk into the ground, # concrete is poured in and J: of concrete tae shell, which crete filling but ing agent, is first after which the allowed to harden. pile, which has only §&% put on the market, ¥% ground in a novel collapsible steel the size and shape plete pile, is sur- recently been is put into the } manner. A core, exactly of the com- rounded with a reinforced steel shell, which is driven into the ground by a steam hammer to the desired depth. The core is leaving the steel ground. This, if examination to be filled with concrete is completed. Such subjected to the se- and the results have satisfactory. The holds the concrete to shape while it is har- prevents any deteri- by contact with the earth while the concrete is still soft. The piles are tapered and able to sustain great loads with very little settling. One pile seven- then removed, shell in the found upon perfect, is and the work piles have been verest tests been highly steel — shell the proper dening, and oration caused

Page 12

2 ee A sectional view showing the method employed in driving the steel shell of a new concrete pile into the ground. The shell is tem- porarily provided with a collapsible core, which is subsequently removed when the desired depth has been reached. : teen feet and nine inches long, sustained a load of 120,- 000 pounds, with an actual settlement of but one-tenth of an inch. The original cost of these piles is somewhat higher than those of wood, but it is claim- ed that in the end they are many times cheaper. ‘ 108 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE The man- ufacturers of this pile claim that it is abso- lutely per- mane n t— a feature which, if true, will result in the total disuse of wood piles in time. The _ piles are not subject to decay or to the at- tacks of woo d borers and destroyers. Piles of this type which have been dug up after having borne heavy loads for a number of years, have been found to be as_ perfect as the day they were driven in- to the ground.

Page 13

The Furka Railway of Switzerland By M. Widmer HEN the Simplon Line was in- augurated in 1906 there was prob- ably no other city in the Rhone Valley which derived greater benefits through this feat than Brig, a delightfully quaint community at the junction of the + OSU pT Parmer aren egee of the Bernese Alps, to Kandersteg, Spiez, Berne and Interlaken. The Simplon Railway forms the inter- national highway from the Lake of Ge- neva and the Rhone Valley to Italy, while the Létschberg Line, connecting re aca A collection of views along the route of the new Furka Railway of Switzerland, which connects the towns of Brig and Andermatt. The railway is 424 miles long and employs steam traction. It incorporates 50 viaducts, bridges and galleries, 7 tunnels and 5 loop tunnels. Simplon and Furka post routes. A few years later—to be exact, in the summer of 1913—a second gigantic undertaking, the celebrated Lotschberg Railway, opened another new era for this for- tunate district, and where it formerly re- quired a long railway journey via Mon- treux and Spiez to reach Interlaken, or a trying drive via Gletsch to Meiringen, followed by a train and boat trip to In- terlaken, this modern Alpine road takes a short cut through the huge, rocky mass 409 with the Simplon route at Brig, has brought the Rhone Valley and the Ber- nese Oberland in direct communication. There remained now one other Alpine Pass, the Furka, which had no train service and which in a distance of 42% miles runs from Brig to Andermatt, at the foot of the Oberalp Pass. From Andermatt—which will shortly be con- nected with Gdschenen on the Gothard Line by a 2% miles long electric rail- way, running close to the road through

Page 14

410 the Schdllenen—the Oberalp Pass, prac- tically a continuation of the Furka road, leads to Disentis, an ancient monastic vil- lage with recently discovered radio-active mineral springs, a distance of eighteen miles. From Disentis the Rhaetian Rail- way affords direct communication with all the noted Grisons resorts. To cover-this entire distance of 60% miles requires a journey of one day be- tween Brig and Andermatt and 4% hours between Andermatt and Disentis— a fascinating drive for the tourist who is fortunate enough to be able to travel with leisure, but often out of the question for those who are somewhat rushed for time. The construction of a railway which would form the connecting link. between Brig and Disentis came up for discus- sion a number of years ago, and the con- struction of the line was started in IgII. On June 30, 1914, the inauguration of. the first section, Brig-Gletsch, took place, but four weeks later, when the railroad was actually ready for regular traffic, the European war broke out, and in view of the completely reversed conditions it was decided that the line would only be POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE opened for the summer season of 1915. The trip by rail from Brig to Gletsch takes two hours ; the sections Gletsch-An- dermatt, Andermatt-Goschenen and An- dermatt-Disentis, which will also be open for traffic in the near future, re- quire 1%4 hours, % hour and 1¥% hours, respectively. The new Alpine Railway will thus cover the total distance of 60% miles in five hours. The new railway has steam traction. It is a narrow gauge line, with rack and pinion sections, and possesses an extra- ordinary number of interesting features from an engineering point of view. There are over 50 viaducts, bridges and galleries; seven tunnels and five loop tunnels. The maximum gradient is 110 per cent., and the total length of the rack and pinion sections is 19% miles. It is estimated that the cost of construc- tion for the line Brig-Gletsch-Disentis is over $7,600,000. The Victoria Falls, of the Zambesi River, in South Central Africa, are cap- able of furnishing 35,000,000 horse-pow- er of electrical energy. From Albany to the Panama-Pacific Exposition on a Motorcycle In an outfit consisting of a motorcycle with a side-car attachment containing a complete wireless set, Mr. and Mrs. They will be in constant touch with important wire- less stations on their trip from the East to the Panama-Pacfic Exposition: Robert Wengatz, of Albany, N. Y., started for the Panama-Pacific Exposi- tion, to compete for the prize offered by the officials of the Exposition for the most novel method of crossing the con- tinent. They are to be joined by Fred Wallace, also of Albany, who is an expert wireless operator. En route, they intend to keep in constant communica- tion with important stations. The travelers hope that the war will end in the autumn, so that they can make a tour of the world by motorcycle. ‘Vineclad Pittsburgh—The Triumph of Foliage Over Smoke The bald and smoke-ruined hills of .the great iron city are to become vine- clad, tree-crested and _ brilliant-hued. This seems like magic, but the superin-

Page 15

tendent of parks has imported from Asia Minor large quantities of lycium vine which will cover the bare slopes with the beautiful red foliage. It is able to resist smoke and fog and will not starve on poor soil. Of the native plants sumac and locust have done the best fighting against the Pittsburgh atmosphere and they are to be used extensively on the hilltops. Converting a Street Car Into a Station- ary Repair Shop A street car that long ago outlived its usefulness as a vehicle of transportation is now made to perform useful service as a repair shop on one of the principal streets of Battle Creek, Michigan. Five years ago, the ex-street car was hauled into its present position and placed on a brick foundation. The interior was remodeled so that more space was ob- tained—space ample enough for a work- shop in the rear and a display window in the front. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE After having outlived its usefulness as a ve- hicle of transportation, this car was converted into a repair shop. The shop, liberally decorated with signs and bordered by a well-kept bed of flowers, attracts the attention of all who pass. Surprise Signals to Test Locomotive Engineers To train locomotive engineers so that they will not fail to see signals, some roads constantly use test or surprise sig- nals. Signals are flashed which compel the engineer to slow up or to stop without any reason. If the engineer fails to see the signal he is told at the end of his trip that at a certain point and a certain moment of his run he failed to obey a signal. Thus admonished he is made more alert. The training is continued until it becomes practically impossible for the engineer to pass signals without heeding them. Such testing is regarded by many rail- road men as a necessity. It keeps the

Page 16

turneth away 412 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE engineers ever on the watch for signals, so that in a moment of real danger there is no likelihood of a failure to act prop- erly. Some psychologists assert that the training makes it impossible for the men to fall into the habit of noticing certain stereotyped signals, and not recognizing others. Teaching Office Boys Their Job Office boys, too long the butt of base- ball and funeral jokes, are beginning to be recognized as a vital, necessary fac- tor in the business organizations of the country and are being trained in their duties in much the same fashion as sten- ographers and bookkeepers. There are big opportunities ahead of every office boy, but nine out of ten are almost totally unprepared for their duties. The first school for office boys was launched in New York as a part of the Y. M. C. A. work for boys. M. Marvin Jackson, in charge of the employment bureau for boys in the West Side Young Men’s Chris- tian Associa- tion, is the moving factor in the new school. The course of study keeps pupils busy. They are taught how to run errands so as to cut down mileage and time, warned against way- side loitering w hile on er- rands, made to wrap packages neatly and se- curely, shown how to operate a telephone switchboard, instructed to give the soft answer

that An office boy school ‘is a most modern institution. Hereto- fore, the boys fresh from school lacked the aren training that makes them of immediate value to t wrath from the lips of the nervous in- quirer at the other end of the wire, and taught how to clean ink-wells and sharpen pencils and empty waste baskets, manipulate adding machines, typewrit- ers and copying machines. They are made acquainted with filing systems and the proper methods of addressing en- velopes.

‘“‘The Portmanteau’’—A Theater That Travels With Its Actors A complete theater, which may be packed into ten boxes and sent to any part of the country, has been recently opened to the public in New York. The entire equipment of the “Portmanteau,” as it has been aptly named by its inven- tor, Mr. Walker Stuart, of New York, weighs but three thousand pounds. It can be set up in two and one-half hours and repacked in about one hour. This little theater may be mounted in the gymnasium or auditorium of any school, club or settlement, in the ball- room of a pri- vate house, or in the open upon the lawn. Small though it is, the stage of the little theater offers plenty of room for the sixteen actors and ac- tresses who are to accompany the ‘“Portman- teau” on its travels. The fore-stage is eighteen feet long and six feet deep; the main stage is twenty - two feet wide and twelve feet deep ; the pros- cenium open- ing is sixteen feet wide and twelve high. eir employers. piniiee <qncutiiatiligibiine- —eaimisldhdiiicnio—- a ——w

a oe DS mh ll olCUCUlClkeee ll Ci Thies, Dp wa. mee

Page 17

me Much difficulty was found in provid- ing a suitable lighting system. It was found that forty-two bulbs would give satisfactory re- sults, and that these could take their cur- rent from the circuit in the house or thea- ter where the stage is set up. Each of the lights is inten- sified by a spe- cial corrugated Tile OO Eee oe il POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 413 glass reflector. Modern stage managers are abandoning footlights be- cause they pro- duce. unnatural ef- fects. Since the “Portmanteau’” is very modern, we find lights only in the drops and behind screens in the wings. According to Mr. Stuart, the system is most satisfactory. The scenery is made of fibreboard, held on supports of wood, and all of it has been made fireproof. The arches and struts, although they may be taken apart and packed for transportation, are joined so perfectly that they will bear the weight of a man without straining the joints. Hardly is an invention complete when improvements suggest themselves. Mr. Stuart hopes to substitute metal frames e for the wooden supports, with the re- sult that his theater will be even lighter than it is now, as well as stronger. In the oval: The complete electrical equipment of the Portmanteau Theatre. Below: The portable theatre assembled and ready for use by the actors, as well as the packing boxes in which the Port- manteau Theatre is transported from place to place. Two Telephone Systems Cause Much Confusion in Rochester, N. Y. Physicians in Rochester, N. Y., are fighting for a single system of telephones. There are in Rochester at the present moment two competing companies, and the doctors claim that through the con- fusion of these systems much valuable time is lost in emergencies.

Page 18

414 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE A simple pressure of the foot opens the lid of this improved garbage can, which is both sanitary and convenient. A Buried Garbage Can Opened by the Foot To lighten the drudgery of housework and to improve the sanitary condition of the kitchen, an underground waste can has been invented. It lessens the work of the maid or housekeeper. Press on a plate with your foot and the can’s lid opens. Remove your foot and the cover springs back into place, so that stray hun- gry dogs are foiled in their attempt to satisfy their appetite by tipping the can. How is the garbage collected? An iron frame fits snugly around an inner receptacle. The receptacle is lifted from the frame and the garbage is dumped into the collecting cart. New Fashions in Furniture Casters Millions of furniture casters are made of leather. To produce them, disks of the required size are cut out and ce- mented and compressed to form the wheel. Disks of metal are clamped on each side to serve as bearings for the axle that runs through the wheel. Such casters are made for use on hardwood floors. Similar casters of compressed felt are manufactured for the same pur- pose. Among other styles of casters may be mentioned those of glass, designed to serve as insulators; ball-bearing casters, with no wheel at all, but instead a ball which, when the furniture is moved, re- volves on a circle of smaller balls within the caster fitting; and lastly, caster wheels made of porcelain and of rubber, of lignum vitae, and other hard woods. What Street Is This?— Look at the Curbstone Street signs that can be read as plainly by night as by day have been installed in San Francisco. A waterproofed and protected cast-iron box, forty inches long and eight inches deep, is set into the curbstone six or eight feet from the cor- ner of the sidewalk. Within the box is an electric tube light, connected with the regular street lighting system. The outer side of the box is perforated with letters spelling the name of the street. What is more, the names are placed exactly in position to meet the eye of the passing pedestrian, the autoist or the street car passenger, during the day or night. An electrically-illuminated sign installed in the curb- stone indicates the name of the street by day as well as by night. — «=e £H AA tee! 44 OST KRKlClC ThlhUCOrhF~, a ee ee. ee ee ee ee ee ae he

Page 19

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Winding among the canyons and summits of the Rocky Mountains, this automobile road reaches an alti- tude of 8,500 feet above sea level. It has been built by private capital f or the sole use of automobiles. Due to its narrowness, it is possible for automobiles to pass each other only at certain points where the road is sufficiently widened. A Wonderful Automobile Road in the Rocky Mountains Extending from Manitou, Colorado, to Crystal Park is one of the finest auto- mobile roads in North America, an en- gineering triumph as well as a wonderful scenic highway. This road, winding among the canyons and summits of the Rocky Mountains, rises to an altitude of 8,500 feet above sea level, climbing up steadily from the city more than two thousand one hundred feet in fifteen miles. Only automobiles are allowed to pass over this route. It was buili for automo- biles by private capital. Much of the way has been carved or blasted out of the granite of the everlasting hills. Over the lower slopes the course has been run in most tortuous curves in order to main- tain an easy grade. In one single piece of ground, having only thirty acres of area, is a mile of looped and tangled roadway, forming a perfect maze of highway. Thus a maximum grade of only eight per cent. is secured, a road which is perfectly safe and easy for the biggest machines. Because of the narrow way it is im- possible for motors to pass, except at designated points. Hence the machines going down must wait for the ascending vehicles. This makes it essential to main- tain a perfect schedule for the cars. The Short-Lived Pin Scientific curiosity has led a French investigator to look into the old question of the fate of the ordinary brass pin. By a series of experiments conducted on his own estate he discovered that pins, like human beings, go their way and are re- solved into dust. Hair pins, which the experimenter observed for one hundred and fifty-four days, disappeared at the end of that period, having been converted into a ferrous oxide, a brownish rust, which was blown away by the winds. Bright pins took nearly eighteen months to disappear; polished steel

Page 20

416 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE needles nearly two years and a half; brass pins had but little endurance; steel pens at the end of eighteen months were nearly gone, while their wooden holders were still intact. Pencils suffered little by exposure. A Tower That Fools the Eye What form of building would be the unsafest to the eye, and yet the safest in reality? That seems to have been the whimsical problem that Professor Kohnke, of Dantzig, set himself to solve. The re- sult is the amazing obser- vation tower of Koslin, Ger- many, compar- ed with which the famous leaning tower of Pisa is tame and almost un- interesting. Although it apparently lurches up and out in a drunk- en way, the staircase lead- ing to the top stands as a monument to the strength and adaptabil- ity of rein- A New Discovery About Shaving Soap That the lather with which the shaver covers his face is valuable as an anti- septic, apart from its other uses, is as- serted by a distinguished English au- thority. Soaping the face prior to shaving the beard is regarded merely as a means of facilitating a troublesome operation. A razor is really a saw, and shaving is a process of sawing bristles. Soap is said to extract the oily matter from the hair and thus render it brittle, so that the blade of the razor saws through it easily. With sensitive skins, of course, a soap of good quality and preferably free from alkaline excess is desirable. On the other hand, it might be thought that an excess of alkali would prepare chin bristles more readily than a pure soap or superfatted soap. The corrosive effect of alkali, however, leaves no doubt as to the kind of soap that should be used. Soap probably plays a more 1m- portant role than that of a sa- ponifier of the natural oil of the hair. In spite of the fact that razor users frequent- ly cut them- selves, slight wounds gener- ally heal quick- ly, and the risk of infec- tion thus aris- _ ing seems to be almost il. In most cases, forcedconcrete While this tower appears to be anything but safe, it is so therefore, it is ee : constructed that it compares favorably with any conventional the material structure. It is built of reinforced concrete. of which the tower is built. Before it was opened to the public, the structure was tested to its full capacity with bags of sand, which were left on the platform for. five weeks. At the end of that time it was found that the deflection of the upper landing plate was less than one-tenth of an inch. When the weight was removed, the plate returned immediately to its normal posi- tion. The total height of the structure is about sixty feet. clear that the razor blade must be bacteriologically clean—that is, free from septic matter. This may be attributed to the fact that it is probably dipped into hot water before use, or else that the soap lather is antiseptic. /The latter explanation, it is thought, is the more probable of the two. The amount of soap rubbed on the skin is considerable if the shaving is to ke in any degree com- fortable, and soap has enough antiseptic power to destroy the typhoid bacillus if only a six per cent. solution is employed.

Page 21

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THE “QUEEN ELIZABETH” AS A TARGET The splashes are Turkish shells aimed at the “Queen Elizabeth” in the Dardanelles. No wonder the “Queen Elizabeth” had to withdraw. Below: The forward deck of the “Queen Elizabeth.” Officers study- ing the effect of Turkish fire. Photos. Copyrighted International News Service.

Page 22

418 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THE TOOLS OF MODERN WARFARE An ordinary French field piece mounted to repel an attack from the sky by German bomb throw- ers in aeroplanes and _ airships. When shrapnel is used these field guns are often very. effective aga‘nst air cra‘t. Both France and Germany built oan motor cars —_ airship- repelling guns upon them, as soon ps Eaten war of 1912-1913 proved that the air scout could gather invaluable strategic infor- mation. The guns on the French cars, here shown, have a range of five miles, which is higher than either aeroplanes. or airships travel. Although it is used only once, a shell is made with the nicest care. It must be hardened, for one thing. Here a French workman is shown extracting shells which have been heat-treated in a gas furnace. For use in the Vosges Mountain; the French have developed an especially light field piece, which can be very easily transported. Forty-two centimeter guns could never be hauled up the Vosges Mounta’ns—one reasqn why it was necessary for the Germzns to go through Belgium.

Page 23

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE INTERESTING GLIMPSES OF THE WAR, A German 42-centimeter shell which was hurled against a fort at Verdun did not explode. The French picked it up, and now it stands in the court- yard of the famous Hotel des In- valides, Paris, where French veterans live out their days. The projectile stands five feet high and weighs about a ton. In the circle: A German ma- chine gun mounted to repel air scouts and bomb-droppers. To the right: a gun crew hauling an Austrian Skoda gun from its base for transportation. The Germans keep their prisoners busy repairin roads and streets. To the right: A barrel mount as a field pee to fool inquisitive air scouts. From a heig t of two thousand feet this looks like a mortar.

Page 24

420 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Bata sh 2 KS SN F 4 — THREE PICTURES THAT TELL THEIR STORY A German Zeppelin shed which was destroyed by a raiding party of British aviators. Not only was the } shed blown to pieces but the giant craft within was _ e destroyed. This was, of course, a temporary shed, ; for the Zeppelins are usually housed in brick structures. 3 elon? aS ee An English machine gun carried on a motor tricycle. Every army is using motor driven vehicles of some kind tor the rapid transporta- tion of Maxims. Lowering a British seaplane into the water. The British have been more successful than any other power with this type of craft. Photos Copyrighted International News Service

Page 25

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THE GERMAN SIDE OF THE WAR No, this is not a cosy bungalow for summer use. It is a German officer’s dwelling behind the firing line in France. He insists on having white curtains and a garden. Thus he proves what we all know—that on the western frontier ground is won and lost by inches only. This officer may live in his comfortable cottage longer than most New Yorkers live in an apartment. No wonder that we hear of shower baths and running water at the front. A native village in German south- west Africa. It consists of huts made of poles and skins. The huts are now on British soil, for Ger- many has lost her South African colonies. Handing out» clean linen on the battlefield to German _ soldiers. This is part of a hospital division and the linen is intended for wounded lying on unseen cots.

Page 26

422 A French captive balloon about to ascend in order to note the effect of artillery fire on the German lines. This type of vessel was in- vented by Captain Siegfeld, of the German army, and called by him a “kite balloon.” The bulge at the bottom serves to steady the cra‘t in the air, like the tail on a kite. German soldier watering his horses in a ¢aptured Russian village. The Germans are as careful of the wa- ter which they give their horses to drink as if it were intended fot themselves. POPULAL SCIENCE MONTHLY AND WORLD’S ADVANCE Er ye er ar It is not the mouth of a coal mine, as you may suppose, but the en- trance to a tunnel dug by French soldiers to reach e German trenches and blow them up. Copyright by International Press Exchange. German soldiers besthing in the tubs of a captured laundry. The lace was almost made to order or them, with its elaborate hot and cold water plant.

Page 27

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Who would suppose that these two men are German soldiers? They form part ot a bridge-build:ng company, and their water service uni- form is a rubber suit so filled with air that they cannot sink. Pad- dles are more useful than guns fon the work in. which they are engaged. SN iria sonar Ask~a German to interpret this picture and he will say: “German soldiers reviving comrades who have been overcome by English gas bombs.” yo 4 an Englishman and he will retor*: “Germans over- come by their own gas and inhaling oxygen so as to recover and do it again.” Which side is right? eee tan nares oe

Page 28

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE SHOWING HOW SHRAPNEL IS MADE tani | sricn | SmoweLess I T is one of the grimmest aspects of war that tender-hearted women should be engaged in making ammunition of the deadliest kind. Since the entire arms-bearing population of France is fighting in the trenches women have been recruited to man the machine-tools, without which it would be impossible to produce the shells fired by the thousand during the course of a battle. In the upper picture a French woman is turning a shell; in the bottom view French women are inspecting shells. Two forms of shrapnel are here shown—a German three-inch to the left and a French three-inch to the right. Both are drawn to scale. A shrapnel is really a kind of shell hurled by a field piece at the enemy, which carries about three hundred bullets in its head and is so timed by a rather compli- cated mechanism as to explode above a hostile force and scatter its bullets

Page 29

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE IN THE WORKSHOP OF DEATH & BP HS HOOP RED “} HEDSERESIADI*® > 200] ee ee, “e+ ® ie a over a wide area. Shrapnel is the deadliest form of projectile fired by artillery. ; The range of shrapnel is about a mile and a quarter, which distance is cov- i ered in twenty seconds. It will be noticed that two charges of explosive are contained within a shrapnel shell—one a charge of black powder, the other a charge of smokeless powder. The first is a bursting charge and serves to blow the bullets out of the shell; the second propels the shell from the gun. There is but little difference between the shrapnel shells of the warring powers. To the left on this page appears the type of shell used by the British, while to the right is that used by the Russians. Both are essentially similar to the shells illustrated on the preceding page. In the upper picture Armenians are shown manufacturing munitions of war. The lower picture is the interior of a French factory where machine guns are made. Upper Photo. Copyrighted, Underwood & Underwood.

Page 30

426 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ERE we have a novel type of French trench gun. It fires a torpedo shell which has wings so that it spins and keeps on a straight course. The shell has a rod like a rocket which fits into the barrel’ of the gun. Photo Copyrighted International News Service. ere RG MAS 8 mE, ait

Page 31

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE A Russian field piece which was hit squarely in the muz- zle by a German pro- jectile. The mouth of the gun was torn open. The flaring parts of steel clearly show the rifling o: the gun. This Austrian auto- mobile was crippled so that its rear wheels were useless. To transport it to a repair shop it was partly carried on a motor truck, as shown, with its front wheels on the ground. German troops reconstructing a damaged railway which they required for the transporta- tion of supplies in the Poland theatre of war, where good roads are scarce, and railroads even less common. Photo. Copyrighted, Underwood & Underwood.

Page 32

428 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE HE interior of a Krupp submarine boat is packed with about as much mechanism as a watch. Diesel engines, dynamos, storage batteries, torpedo discharg- ing tubes, not to mention living quarters for the ofh- cers and crew, seem huddled together; yet in reality they are nicely disposed with an eye to making the most of every square inch of space. When submerged, a submarine makes about eight knots; on the surface at full speed, about twelve knots. Before a torpedo is fired the bearings of the ship to be destroyed must be taken by compass. Then the submarine launches a torpedo. Once below the surface, a submarine is blind. There is no way of training the torpedo except by trimming the entire boat.

Page 33

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE The torpedo compartment of an Italian Fiat San Georgio submarine boat of 250 tons. The two torpedo launching tubes are clearly visible in the lower part of the picture. The Italians have done as much as any European power to develop the large submarine boat. Two periscopes are often found on The eyepiece of a periscope as it submarines, so that at least one appears in an Italian submarine may be left if the other is shot off. boat.

Page 34

fa a A SR i ' 4 30 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE An Italian subma- rine leaving the cylinders of a float- ing dock. The ves- sel is tested in the cylinders for wa- ter-tightness from time to time. A submarine boat in course of con- struction. Circular steel hoops would make it seem as if a huge steel barrel were being built. THE UNDERWATER PERIL What the man at the eye- piece end of a periscope sees. He has a clear view of the entire horizon. No ship escapes his eye. Without a periscope a submarine would be sight- less. It has_ therefore been well named “the eye of the submarine.” RNG Ne

Page 35

5th AERIS POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THE GRENADIER IS RESURRECTED How the war methods of long ago are resorted to in the present war, due to the requirements of trench warfare woe trench fighting has revived the use of weapons which military officers thought had been abandoned for good and all more than a cen- tury ago. It is necessary to throw bombs and grenades into the trenches of an enemy. To do that both the Roman catapult and the old-time grenadier have been resurrected. Progress is made backwards in this war. The picture shows grenadiers of modern times—their heads protected by steel helmets against shell splinters, their chests guarded by bullet-proof waistcoats, and their lung; protected by masks which cover their nostrils and mouths. Various forms of grenades are shown in the small pictures, the two top views illustrating a grenade hurled by a rifle and the two lower views hand grenades used re- spectively by the French and Germans. Photcs, Copyrighted, Underwood & Underwecd | |

Page 36

SSS RSS SR a 432 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THREE NECESSARY WAR MACHINES Locomotives are as important as cannon in this war. Were it not for their marvelous system of railways, the Germans would not have succeeded in shifting troops and supplies from one frontier to the other. ere we see a double end loco- motive in distress. To the right: An Austrian field howitzer. The short cylinder beneath the gun takes up the recoil. ] / jig tite Mig iy = — xf, \ AoR\ ai / TAL, £9 8 WSL ANY ia. aN A German cyclists re- pairing their wheels. Most military bicycles are collapsible so that they can be carried on a man’s — if need e. eee ree Ai erence

Page 37

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 1, THE AFTERMATH OF A CLOUDBURST That a heavy downpour of rain is capable of creating havoc com- parable to that of an FRX “ earthquake is i — % i “4 ~ ; aM proven by . b. eS > j these pic- tures. Here are _ various views of de- struction aris- ing from a cloudburst. One of the hundreds of houses that were wrecked in the city of Erie, Pa., during a recent cloudburst. Owing to the dis- organized police protection, the State militia was placed on guard, Railroad embank- ment that was washed out by the onrush of water fol- lowing the cloud- burst. At the left: Searching parties at work among the debris, clearing the wreckage and hunt- ing for bodies. Photos. Copyrighted, Underwood & Underwood

Page 38

434 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE OUR COAST DEFENSES ARE IMPRESSIVE According to Captain Charles E. Kilburne, of the General Staff of our Army, our twelve- inch coast detense guns seem more terrible than they really are. Their extreme range is fifteen thousand yards, but a German or an English fleet from the safe vantage point of twenty thousand yards could disable them easily with the aid of aeroplanes to direct the fire. The trouble is that the coast ‘defense gun can be elevated only fifteen degrees, whereas foregn war vessels can elevate their guns anywhere from fifteen to thirty degrees and thus throw their shells farther. If our coast defense guns could be mounted so as to permit their elevation to a maximum of forty-five degrees, a range of 33,000 yards would be possible. The officers of the Coast Artillery are now trying to work out a plan of modifying the carriage mechanism so that greater elevations are possible Photos Copyright, Underwood & Underwood Mortar batteries are sunk in_ concrete pits. The men who fire the guns never see where the shots fall. The mortars are trained in re- sponse to telephone directions given by the men at the range finders. The Eighth coast defense com- mand of the New York State National Guard is here shown drilling with 12-inch mortars at Fort Wright on Fisher’s Island. Loading a twelve- inch mortar. The shell is brought to the piece on a little wagon and driven into the breech of the gun with a ramrod. Our mortars are about as good as the best made by Krupp

Page 39

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE The chart room at Fort Wright, where the exact positions of the targets are located. Once a ship comes within range of the guns it is almost sure to be hit. Its po- sition is determined ex- actly by a simple system of triangulation and telephoned to the gun- ners. The targets which are used to train the crews of our coast defense guns. They are simple canvas | gtas yrs carried on a raft and towed at a safe distance by tug- boats, at moderate speed, Photos. Copyrighted, Underwood & Underwood The muzzle of a_ twelve-inch coast defense gun. It is ‘mounted on a_é disappearing carriage. ‘The recoil of the gun drives it back on its carriage below the parapet. Disappear- ing carriages were invented by: Colonel Buffington and General Crozier of our army. No other power has adopted them. i | j j ] j | } | } i

Page 40

436 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE A GIANT BRIDGE OF STEEL AND CONCRETE View of the anchorage at the back of the span which will form part of the giant steel arch bridge over that part of the East River known as Hell Gate, New York City. The anchorage is of steel and will later form part of the ap- proach to the bridge. This view shows part of the huge arch "oaier At ed age bien ridge, when complete will be the Sonsiest and aoe ag ws single span steel arch bridge in the world. 80,000 tons of steel will o.into the arch. It will e 1,000 feet between abutments and will carry four railroad tracks. ; DE epr4> Se Pst rs oat The line of concrete arches that will carry the approach to the main span. There are 120 of these arches, the tallest one being 124 feet high.

Page 41

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE At the right: The only winding stair- way in the United States that is made entirely of concrete is located at Glens Falls, New York. It has fifty steps and makes two complete turns. Above: What happened when an au- tomobile struck a deer. The deer was instantly killed; the car turned turtle, caught on fire and was entirely destroyed. All that remains of the hull of “The Revenge,” one of Bene- dict Arnold’s fleet which was defeated by the English at Val- cour Island on October 11th, 1776. She carried eight guns. The old hull was_ recently raised out of Lake Champlain and placed on exhibition on the grounds of Fort Ticonde- roga, N. Y. Built in 1838, this water wheel was in continuous service until 1890, at Troy, New York. 4 37

Page 42

438 steamer cess. May” Sentinel Island, Alaska, was per- haps the most re- markable ever seen on the Pa- cific Coast. The vessel ran on the _ reef at high tide. At low tide two- thirds of the hull was in mid-air. At the next high tide the ship was floated, wi practically no damage. Below: The double claw of a lobster captured at New Bedford, Massachusetts. ever, is of no value to its At the right: A a The extra claw, ssessor, since it is fixed. by a Papuan for holding er child. A rest station built of heavy cobblestones and Portland cement. This rustic work is costly; in this instance the sum of $400 was expended. Some, of the boulders weighed 1,500 pounds. ra

Page 43

iia cei ona aia an PBA Be AME nicl. eta SPD. Se DOA ay a2 ea 7 How Movie Men Film Royalties By Ernest A. Dench TT“HE filming of royalties presents probably the most difficult task a moving picture camera man can possibly encounter. Kings and queens are zeal- ously guarded, and access to them is had only by long and tedious waiting, if at all. The authorities must be extremely careful, as the trick has already been tried by terrorists of disguising an anar- chist as a movie operator. Fraudulent credentials have been used repeatedly. In England, when a royal procession is held, the route they intend traversing is circulated beforehand. This affords the photographers an opportunity of se- lecting an advantageous position. Ex- citing competition for best places results. Operators as a result often seize an ad- vantageous viewpoint and maintain pos- session by remaining for a night and until the procession passes. One time, when King George and Queen Mary attended the horse races, the rumor was circulated that the militant suffragists would make an attack on the royal automobile, so steps were taken to prevent every suspicious character from approaching. The police even forbade movie photographers being present. ' However, the rumor reached the ears of King George, who is an ardent movie fan, and he issued a statement which has become an epic in moviedom. “Only a few thousands of the mil- 439 lions of my countrymen throughout the world can see the part I play in this event,” he said, “but a motion picture can convey it to all my loyal subjects whether they reside in London or Aus- tralia.” In Germany, the difficulties are even greater. The operators are asked the most searching questions by the author- ities and have to make the best they can of the position, which is seldom satis- factory, allotted to them. They are also required to promise not to export the film without submitting it to be deleted of any military information of any value to an enemy power. At all events, these rules were in force before the war, and in all probability they have since been made severe to a point almost beyond conjecture. The moving picture as a result of which these stringent rules were made depicted the entry of Emperor William’s daughter and fiance into Berlin. This was exhibited at the Berlin theatoriums on the same evening. The police inter- vened, and all of the copies in circula- tion were confiscated. Russia has long been recognized as the home of the iron hand even in times of peace. The Czar values his privacy highly ; at least moving picture men find it the height of impossibility to gain an interview with him.

Page 44

| | | / | | | | | H } 440 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Although the moving picture photog- raphers are more greatly restricted now than in the past, one time, during the reign of Alexander III, a dauntless op- erator succeeded in filming the imperial family at three yards’ distance, some- thing that has never before been accom- plished during a Russian official cere- mony. However, this daring feat was accom- plished in the pioneer days of cinematog- raphy. HOW FAKE WAR MOTION. PICTURES ARE MADE \ 7 AR pictures, so we are told by a London correspondent, are even more popular in Great Britain than here in America, and the English people are now reveling in vivid war dramas which are faked on the hillside and ‘the rolling downs of. the south coast. Clever me- chanical devices, the unstinted use of electricity, spring bayonets, gunpowder bladders and underground explosives are used in the production of grim war pic- tures, realistic to a degree and bearing the earmarks of the French and Belgian trench and the Polish battlefield. Agricultural laborers, farmers’ sons and village youths, dressed in the uni- forms of the British and German armies, are drilled in their new duties and ini- tiated into the mysteries of disappearing bayonets, exploding fake shells, trench warfare and make-believe “gassing.” . Stroll along a quiet, country footpath bordering some rolling grassland slop- ing to the sea and you may come upon a horde of yelling men whose spiked helmets and wicked-looking bayonets glint in the sunshine as they charge to- ward you. If you take cover nimbly and On the screen the German soldiers are seen crossing a stream with the enemy shells falling dangerously close to them. In reality, the columns of water are caused by bladders filled with gun powder, which are . concealed below the surface of the water and electrically exploded at the desired moment.

Page 45

ane a wail BO hing ATMO CP aie ES > sa Legit eg he ea POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE THE SPRING BAYONET SPRING~ To the audience the scene is one of a most desperate nature, with the German and English infantrymen engaged in a life-and-death, hand-to-hand bayonet encounter. But the scene loses much of its thrill when it is explained that the bayonets are provided with safety tips and slide against a spring in a tube, when pressed. watch you will see they are rushing a trench filled with khaki-clad British sol- diers. You shudder involuntarily as you see those glinting bayonets sinking into human flesh three or four inches, but you find later that the points are pro- tected with little felt buttons and that they are attached to the barrel end of the rifle by a spring that allows them to re- tract several inches upon striking a solid substance. As the soldiers ford a stream in their mad charge, columns of water splash high into the air. After awhile you realize that these columns are caused by dropping shells from concealed artillery. You wonder how it is that all these coun- .try “supers” are not maimed or even killed until you find out that the water columns are caused by electrically-ex- ploded bladders filled with gunpowder and hidden beneath the surface of the stream. As the charging “Germans” reach the opposite bank and make straight for the “British” machine guns, terrible explosions occur. They are the shells still “dropping” from the British artillery. The explosions are electrically controlled by a stage director or pro- ducer, and are caused by burying small cans of gunpowder here and there under the ground to be rushed. At the proper moment the fake mines are exploded by throwing a switch or pressing a but- ton, thus sending clods of earth, a cloud of smoke and a dummy figure or two into the air. All the vivid effects of a big shell bursting on the ground are thus obtained. ‘ To give to the moving picture patron an idea of the vast numbers of troops -now in France, the producers used an ingenious leather band machine, which, in conjunction with a broad window built into the scenery wall, is all that is necessary. The spectators in the theater see women at the window waving out to the departing troops. The tops of rifles with bayonets fixed move past the window and bob up and down in a never- ending stream. Beneath the window, concealed from the spectators, an oper-

Page 46

442 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 6, & What a large cast the company must have employed to produce this But look at the picture showing troops passing by the window! next picture. ator turns a leather band passing over two fly-wheels about twelve feet apart. Attached to the top of the band are rows of bayonets. As the handle is turned the bayonets move along with the realism of a marching regiment, rifles on shoul- ders, fastened, as they are, to the leather band which can be moved at any speed.

In “close-up” pictures of big explosions, such as bridges, forts and the like, it is not politic for the movie men to get too close ; a chance projectile may come their way. To overcome this difficulty the camera is set up in some adjacent spot and focused upon the scene of the explosion. From a safe distance the oper- ator controls his camera by electrical wires, the re- sult being as satistactory as if he had been on the brink of the scene him- self. So excellent are the pictures of modern “warefare” thus obtained by producers in rural Britain, that the motion picture theatre patrons cannot realize that mo- tion picture men are not allowed near the firing line in the theatres of war and that the restrictions imposed on the pro- ducers prevent them from obtaining the real thing in France.

Motion Pictures Aid in Teaching Students of Agriculture The Agricultural College of North Dakota is making extensive use of mo- tion pictures in the lecture course which is given by the college. Other reels are educational, showing im- proved methods of farm cultivation, the detection and prevention of disease to animals and to crops, and other subjects tending to inspire the farmer to greater efforts in efficient farming.

Mr. A. P. Hollis, the lecturer, has traveled in the past two years with a motion picture ma- chine and an unusually complete set of reels. Some of the films serve women to the college, showing the general ac- tivities of the campus,

: a: to draw young men and <7

views of the buildings, and the various phases a uous of outdoor construction. '* Proiections A continuous belt mounted between pulleys and provided with bayonet- furnishes the “army” that is passing by in the above view.

ss an Sa ACORN

Page 47

"+ erm Lite Fy es ae soc chasse nareanan AER Pa ERI Goes 0 0 The Secret of the ae Cartoon By Eustace L. Adams E have been watching a famous W “Animated Weekly” for fifteen minutes. We have seen pictures of fires, of disasters entailing the loss of hundreds, even thousands of lives, and of the cruel and heartless World War, until our spirits are at their lowest ebb. Before our eyes French and Belgian vil- lages are wiped out by the struggles of nations, and ambulances carrying maimed bodies flit past, until we feel that the world is all awry. Suddenly the pictures change. Our old friend, Col. “Heeza Liar,” appears and, after a few minutes of ridiculous and absurd gamboling, the world is set right again, and our spirits soar to par. How is it done? Whose is the skillful hand that can produce this animated cartoon, most popular of screen comedies? Remember that a motion picture film consists of thou- sands of scenes which are flashed on the screen at the rate of sixteen a second—so rapidly that the eye cannot perceive the in- ; motion that the sensation of comtinuous motion is produced. Who has the patience to draw thousands upon thousands of pictures which are all thrown upon the screen in so short a time. Seated in his little private office in a great building near Madison Square, and surrounded by volume upon volume on zoology, sits J. R. Bray, one of the most famous of motion picture cartoonists. From struggling newspaper artist to head of a syndicate supplying the ever- increasing demand for animated cartoons is the tabloid history of his career. At the present time Mr. Bray has a staff of six cartoonists, twenty assistant Bray has made a thorough study of : the producing of animated cartoons in screen. The result is 445 artists and four cameramen constantly at work preparing 1,000 feet of animated cartoons every week. An idea of the amount of work entailed may be gained from the knowledge that there are thirty- four different processes to be undergorie by each cartoon, and that there are from three thousand to four thousand cartoons in each thousand feet of completed film. Hence a week’s output involves from 102,000 to 136,000 processes. The accomplishment of this tremen- dous task is made possible only by a special method which Mr. Bray has in- vented and patented. Asa result of Mr. Bray’s invention the work of preparing thousands of pictures is cut in half. When he has decided upon the desired scene for the antics of “Heeza Liar,” Mr. Bray first makes a background on a sheet of heavy paper, which background is then printed on many sheets of tracing paper. This done, it is necessary for the artist only to draw the parts which are to appear in motion on the : ictures and his name is known terval, with the result to the oe Sa of thousands who go to the movies. evident. The back- ground remains abso- lutely stationary throughout the scene, so that the work of the artist is reduced to a minimum. If a man is to be represented as standing still for any length of time, he is printed on the sheets. He docs not have to be drawn again until he is supposed to move. This permanent background may be easily erased or drawn over. What is more, a large number of copies are printed with portions of the background omitted. This obviates the necessity of erasing to a great extent. In order that movements may be both steady and continuous on the screen, great care must be taken in the drawing

Page 48

POPULAR SCIENCE MONTHLY AND WORLD’S of the cartoons, a task greatly simplified by Mr. Bray’s use of tracing paper. The artist merely places a piece of paper upon the last drawing, so that the posi- tion last taken by the figures shows clear- ly through the paper. Thus he is able to draw in the next position carefully and easily. Mr. Bray supervises personally every stage of the work. He criginates the plot and makes from six to a dozen sketches of the vital points of the story. Then the real work commences. While the cartoonists do most of the sketching, Mr. Bray draws practically every move- ment. If a man, for instance, who has been motionless for some time, is re- quired to raise his arm, the staff cartoon- ists draw the figure, but Mr. Bray draws the arm in the act of moving. When the sketches have been made, they are turned over to the staff of assistant ar- tists who complete them, drawing them in ink and filling in the color. To reduce the effect caused by the projection of much white light on the screen, Mr. Bray has invented and pat- ented a process for making a uniform background. By this method one paint- ing of the background suffices for the entire reel. When the set of cartoons is com- pleted four expert cameramen photo- graph them to obtain the negative film. An important feature of Mr. Bray’s in- vention consists of a method for con- trolling the speed of action in the pic- ture. This is done by varying the num- ber of photographs taken of each car- toon. For instance, if the scene demands that an object shall move rapidly, then slowly, and finally come to a stop for a moment, the pictures representing the quick action would each be given one exposure. As the movement of the ob- ject diminishes in rapidity, each pic- ture is given a correspondingly increas- ing number of exposures. When the action comes to a stop numerous pho- tographs are taken of the same pic- ture, the number being dependent upon the length of time that the action is sus- pended. ADVANCE Two strips of typical animated cartoons produced by J. R. Bray. abe

Page 49

2S AL esi

Behind the Scenes of a Motion Picture Play By Loring Brent NE of the greatest differences which exist between the speaking stage and the motion picture studio is the mat- ter of temperament. The stage will al- ways be characterized—as it has been characterized throughout its traditional past—by temperament. The motion pic- ture studio, because of the factory ideal toward which it is tending, may not be temperamental. Thus, at the Essanay

Above: A log cabin erected for a motion picture play. While in the film shown to the audiences the cabin appears as a complete dwell- ing, it is in fact but a front only.

studios, where I saw the filming of “The White Sister,” featuring Viola Allen, factory schedules and factory rules are enforced. The hours are from 9 a. m. to 5 p. m., with time out for lunch. There is even a time-clock to prevent the tem- perament from side-stepping. “The White Sister” is a long feature film, probably six or eight reels, and it has required many special sets. The work in progress on the morning of 445 which I write, illustrated an interesting phase in the making of long feature plays, or plays of any length, for that matter—the filming of “flashes.” <A “flash” is a very short scene which is thrown on the screen for a few seconds to indicate usually the development of a minor plot. It may show, for example, the neglected wife of an absorbed busi- ness man enjoying herself at a cabaret,

Below: The “lake” in back of one of the leading motion picture stu- dios is barely twelve feet in diam- eter. Yet on occasions it serves for scenes representing large lakes or rivers! while the main theme of the play—her husband in some financial venture—occu- pies the long scenes. The brevity of flashes indicates their relative unimpor- tance. Nevertheless, the production cost of flashes is often greater than that of longer and more important parts. The scenes which traced the major theme of “The White Sister” had been completed; the flashes alone remained. One of these, a private room in a hos-

Page 50

446 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE pital, was being filmed. Six times at least Miss Allen, at high dramatic pitch, went through the rehearsal before the camera crank was turned. Although the flash would consume at the most thirty seconds on the screen, the time required for per- fecting it amounted to atleast three or four hours. Trolleys For Lighting “The White Sister” was produced in one of the largest artificially lighted studios in America. The method of light- ing is as interesting as it is efficient. Long rows of mercury-vapor arc lamps are suspended from the ceiling on trol- leys, so that their light can be thrown upon a scene by merely pulling long cords which run over pulleys and down the side walls. The lights receive elec- tric current through trolley wheels from copper trolley wires above them, just as The faces of the leading characters are intensified, and attention thus drawn to them by the concentrated rays of flaming arc lamps. Precautions are taken that a player does not face these lamps any longer than is absolutely necessary ; they are almost blinding in brilliancy. Once an actor was compelled to stare for a certain dramatic effect directly across a set of these lights into the face of the “villain.” He stared too long, and lost the use of his eyes for several days. Not every type of actor is fitted for the “movies.” A girl may be pretty, a man handsome, yet their features may be of a. type utterly unfitted-for-camera drama. A long or a broad face becomes gro- tesquely exaggerated. The eyes may be too dull—effective “movie” eyes are usu- ally large and brilliant. Then, too,, the complexion is vitally important. Exces- sive pallor is grewsomely intensified when it.is filmed. High color in patches The em studio of any motion picture nevecmna is an upocing structure from the viewpoint of the ayman. It is usually a steel a street car derives its energy from the wire overhead. All scenes are illuminated by the greenish light from the long glass tubes. amework covered by t ousands of panes of glass. on the skin appears a deathly black on the screen—and often no amount of paint and powder will conceal the defect ; mercury light seems to penetrate directly we

Page 51

ie ane Orne FS to the surface of the flesh. Another in- teresting fact is that some faces “photo- graph better,’ as directors say, than POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 447 assortment of old stage coaches, hansoms and “props.” The “lake,” which is a concrete basin, +> a | S| 3 —_— : 4) 9,fa e Ne ‘ / ’ Aq f) a 3 ea * s The “back yard” of a motion picture studio contains the most diversified collection of dwellings, vehicles, structures and geographical features imaginable. In fair weather most of the scenes, whether they are “Interior” or “Exterior,” are taken outdoors. others. Some are clearly defined ; others are blurred and hazy. No one knows why. The Queerest of Back Yards The back yard of the Essanay factory is the queerest place imaginable. In size it measures about two hundred by six hundred feet. In the diversity of its possibilities, it measures more than that number of miles. Standing in the auto- mobile tunnel which leads through the building from the street, you see in a semi-circular sweep of the eye all this: A desert, a “lake,” a farm yard, a garage, a section of the Wild West, a fashionable residence, a stockade of the days of ’49, a beautiful green lawn, smooth enough for lawn fétes and tennis, and a curious is hardly more than twelve feet in diam- eter; yet it serves its purpose well. A scene may be required showing a man in the act of diving into a river. The camera is adjusted so that the lens covers the water only—not the concrete rim. A soft mattress is tied to the bottom to deaden his fall, the actor dives in—and the camera is stopped. When the story is told on the screen, the water ripples away on all sides of the picture, and con- veys the desired effect quite as well as if a river or lake miles in extent had been utilized. On other occasions, during garden scenes, the “lake” serves the duties of a fountain, a pipe connecting it with the water main. The “desert” is a sprawling pile of white sand. Although there are build-

Page 52

448 ings and fences within twenty feet of this sand pile, a camera fitted with an ex- tremely narrow-angle lens is employed for taking desert pictures. A horseman appears in the film as solitary as if he were in the heart of Sahara. . There are some pictures that cannot be “faked,” however. Occasionally a scenario is written in which ocean or mountain backgrounds or races of vari- ous sorts figure prominently. Such films are carried in stock in large quan- tities. FE. H. Calvin, a director and act- or, travels about the country taking “stock” pictures for this purpose. Re- cently he took motion pictures of the Derby Race at Lexington. The film may not be used for months, but it will lie on the shelves in the stockroom until a play is produced in which horse racing is the background. Bits of the Derby race will be inserted as the plot is de- veloped. Reality to Secure Reality On the northwest side of Chicago, fifteen or twenty minutes by the elevated from the Essanay plant, is the blockful of studios and factories occupied by the Selig Company. Only one studio was in commission when I visited the plant, the others serv- ing temporarily as garages and store- rooms. “The House of a Thousand Candles” was being produced in a large glass-covered room. The library scene, which is the center of interest of the story, had just come from the skillful hands of the carpenter. It is worth comment. In the first place it was real- istic enough to be truly homelike. The walls were not the patently artificial type usually found in a moving picture stu- dio; they were substantial, and their color was soft. A generous library of real books lined both sides of the room. At the end was a fireplace with a genu- ine fire log, and before it a comfortable leather armchair. Those who are familiar with Meredith Nicholson’s “The House of a Thousand Candles” will recall the secret panels of the fireplace, through which John Glen- arm, the old house owner, supposedly dead, made _ nocturnal visits. I POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE searched for the panels in the fireplace of Selig’s “House of a Thousand Can- dles” for ten minutes before I found them—so perfect was the matching of the boards. How Actors Are Selected According to Type The ingenuity and the care exhibited in the construction of the panels and, in- deed, the rest of the scenic structure, is but part of the Selig system. A year ago, in the Selig’s Los Angeles studio, I was shown a card index system for filing the names of applicants. The ac- tors were classified not by name but by type. John Jones was not John Jones at all: he was merely one of a large number of nonentities listed on cards under the index “English Butler.” There were several thousand cards in the file together with the telephone numbers of the applicants. If a society matron is wanted, the director consults the file, se- lects one of the cards under the index “Society Matron,” and requests the ap- ‘plicant to call upon him. In the wardrobe room at Chicago I saw a similar example of this remark- able methodization. There were hun- dreds of lockers and drawers arranged in tiers and rows about the room. All were numbered and indexed. If one of the directors wants fifty complete uni- forms for a Civil War play, or twenty- five Louis the Sixteenth costumes for a story of the French Revolution, he states his wants to the woman in charge of the wardrobe, and the uniforms or costumes are ready in an hour if need be. Composing Music with the Aid of a Wax Phonograph Record Of great aid to music composers is the invention of a Swedish inventor. Con- necting with the keyboard of a piano or organ is an electric device which tran- scribes music as it is composed on a wax ribbon, from which it may be copied. Improvisations are then recorded. The idea is not altogether new. Such an in- strument, the invention of a Viennese, has long been installed in the German Technical Museum of Munich.

Page 53

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE imi he vibration caused by a detachable motor when it is installed in a canoe, a Canadian inventor ey Tes pp ee that athe fed fastened to the stern and which carries the motor. Thus the vibra- tion is confined to the auxiliary craft and does in nowise affect the canoe. A New Type of Detachable Motor for Rowboats and Canoes Detachable motors have for several years greatly increased the pleasure to be derived from the ownership of a row- boat 6r a canoe. Much difficulty has been experienced in the past because the vibration from these useful little engines has often strained the frames of canoes to which they have been attached. The weight of the engine is all supported by the extreme stern of a fragile craft. Hence the frame is loosened and the entire hull weakened. The accompanying illustration shows the method invented by a Canadian mo- torboat inventor to obviate this difficulty. He has built a floating frame which -is to be attached to the stern of the canoe. Buoyed up by air chambers, this frame supports the weight of the engine, and keeps the propeller immersed in the water to the proper depth. Most of the vibration of the motor is taken up by the frame, and the hull is eased of the strain to which it was formerly subjected. . Dyeing Silk Before It Is Silk Silk is the secretion of two glands of the silkworm lying alongside the diges- tive canal. These glands, which consist of numerous coiled tubes, terminate in a spinning-wart. From a common orifice in the spinning-wart the secretion, of the consistency of honey, issues forth, promptly hardening into a thread on ex- posure to the air. Usually the silk is colorless on leaving the body of the silk- worm, but sometimes it is straw yellow or greenish. Why? The answer has been a matter of long dispute. Some claim that the larva itself pro- duces the color; others ascribe it to im- purities acquired upon secretion; still others are of the opinion that the green color of the leaves of the mulberry tree is the cause. Two French scientists, Levrat and Conte, determined to settle the dispute. They fed silkworms on mulberry leaves which had been satur- ated with non-poisonous aniline red and aniline blue. With what result? Not

Page 54

SS os ne 450 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE only were the silkworms turned red or blue, but their secreted silk assumed the respective colors. Who knows but some day we may be dyeing silk in the leaf instead of in the vat. A Man Who Built a Round House for Himself This “Round House,” located in It was an eccentric gentleman who had this bizarre round dwelling house built. It has no advantages other than being conspicuous. Somerville, Mass., was erected by an ec- centric who thought not only that a cir- | cular dwelling could be built at less ex- pense than the ordinary frame dwelling, but that more room would be obtained. A circle forty feet in diameter was laid out, a cellar dug, and a solid foundation built. The walls are made of plank sawed to fit the circular foundation and nailed together in regular rows. Nearly two years were required to construct this house, which is three stories in height, and contains fifteen rooms. The door knobs are of glass, with white medallions bearing likenesses of the Presidents of the United States. A recent electrical invention is in the form of a latch for automobile doors that opens when a push-button is pressed. s Growing Mutton by Electric Light A novel method for fattening mutton has been recently developed among the big ranchers of Oregon. The sheep pens are wired for many light bulbs, and dur- ing the winter the lights are turned on at four o’clock in the afternoon, in other words, at dusk. The sheep feed so long as the pens are lighted. At nine o’clock the lights are turned off until four o’clock in the morning. Feeding recommences. The ranchers claim that this frequent feeding brings them to the market stage very quickly. A Sprinkling Cart That Carries Its Own Pump Instead of taking water from a tank or through a pressure pipe, the sprinkling carts on the highways of Marin County, California, make use of gas engines, Water, whether from a hydrant, tank or pond, is always available te this sprinkling cart, which car- ries its own pumping equipment. which are carried upon the rear of each vehicle, and which are used to pump up water for wetting the roads. Such is the abundance of the water available that the system of using a small, gas-propelled pump makes it unnecessary to build ex- pensive tanks and permanent pumping plants for the use of the water wagons. AO cg ca Erna soe .

Page 55

pv SANA i wo eae ae —— ry A New Food from the Sea By Charles Alma Byers LONG the coast of southern Cali- mitted the product to be labeled tuna, | fornia there is being rapidly devel- under which name it is marketed. ped a new sea-food industry that threat- Both the albacore and the tuna proper ‘ens to rival the canning of salmon. The are game fish, and have long been famil- new material of this newly established iar to the deep-sea fishermen of southern industry is the .tuna fish. In 1913, California. Certain species of the tuna 115,000 cases, of four dozen one-half have been found in various parts of the and one-pound cans each, were put up — world, notably in the Mediterranean, but and disposed of, and in 1914, with ten so far the albacore branch has been companies engaged in the industry, the found only in the waters of the Cali- 2 Although a newly established industry the Tuna Canning activities of Southern California are already said to be serious] pees xa the canning of salmon. Here are seen the women workers in a typical cannery. The fish are first beheaded and hung by their tails te drain. All the skin and bones are then removed—the white meat only being used—and the useful portion baked in large ovens. The packing then takes place, a single piece being allotted to each can, in salad oil. output amounted to nearly 300,000 cases, fornia coast. And even here they seem valued at $1,500,000. Experiments in to be confined exclusively to the stretch tanning tuna had been made for about of water extending from Santa Barbara three years, but not until 1913 wasacom- to San Diego. In season—that is, from mercially successful method evolved. about the first of June to the middle of The tuna fish which is canned is more January—they are found in large quan properly called albacore. It belongs to a_ tities. branch of the tuna family. The real tuna The fish employed for canning pur- frequently weighs as much as one hun- poses range in weight from fifteen to dred and fifty pounds, whereas the alba- forty pounds. Because of their size, they core rarely exceeds one-third of this must be caught with hook and line. All weight. Because of the family connec- attempts to take them in nets have failed. tion, however, the Government has per- Since they run in large “schools,” two or 451

Page 56

452 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE four fishermen, in a gasoline launch, will daily return to port with from six hun- dred to four thousand pounds of fish. Small sardines are used for bait. The fishermen are mainly Japanese. The fish is extremely powerful, and fights hard. It is of steel-blue color, is very solid, and is of true torpedo shape. During the past season, nearly one hun- dred boats were regularly engaged in tuna-catching for the canneries. The fish are first beheaded, and are hung up by their tails in the packing house to drain. All skin and bones are removed. Only the white meat is used, which is baked in large ovens, and then packed, usually a single piece to each can, in salad oil. The product has a taste not unlike that of chicken, and is very much in demand wherever introduced.

Cleaning Four and a Half Miles of Water Main With An Internal Scraper The difficult task of cleaning a long water main of large diameter without seriously interrupting the service has been recently completed at Merced, Cal- ifornia. The main, 2:,570 feet long, had been in continuous use for 27 years, and had been so much incrusted that its service was becoming inadequate. It had been found necessary, when a full peak load of water was needed, to augment the service by drawing water from wells by three large pumps installed for the purpose. Do you believe that water supply pipes are scrupulously clean? If so, take a look at this little mountain of from a water main at Merced, California, 24,570 feet long. The device seen at sediment that was removed The device for cleaning the pipe was a self-propelled machine, built on the principle of the water turbine motor. The water pressure behind the machine forced it through the pipe, at the same time rotating the vanes and scrapers that removed the incrustation. The entire length of main was cleaned without re- moving the machine from the pipe. The material removed made a pile ten feet in diameter, and four and a half feet in

tak <a k ft, especially intended for the purpose of cleaning w ater mains, was used for the task.

Page 57

height. The contract was fulfilled to the letter, and the contractor received a bo- nus for increasing the capacity of the pipe beyond the terms of the contract. The cost of removing the incrustation was fifteen cents per linear foot. Radium in the Air We Breathe Researches have been made to ascer- tain whether there is any relation be- tween the state of the weather and the electric condition of the atmosphere, but not with much success. Recent investi- gations indicate a plausible reason for this failure. The earth is continually exuding a radioactive emanation, which electrifies the atmosphere from below and interferes with the measurement of electrical charges due to aerial move- ment—exactly what the student of the weather is trying to get at. Experiments show that the air in an empty water-tank of about six hundred and fifty cubic feet capacity is as radio- active as if it contained a small ascer- tained proportion of radium bromide. It follows that if the atmosphere covering the land surface of the earth is as active as the air in Montreal, for example, for an elevation of six-tenths of a mile, six hundred tons of radium bromide evenly distributed over that surface would con- tinue to produce emanation sufficient to equal in its effects those observed in the case of the empty water-tank. Vessel’s Whistle Dislodges Glacier Ice Dislodging thousands of tons of ice by a mere blast of a whistle was the re- markable feat performed on an Alaskan steamship. It took many hours for the captain to get his ship in the right posi- tion. Finally he struck the right point ‘and the vibration from the whistle caused tons of the ice from the Taku Glacier to come crashing into the sea. This glacier is located in the southeastern part of Alaska. The steamship had to sail very near to the shore to perform the feat. Tourists declare that the spec- tacle of the tumbling ice surpassed even the sights further north on the Alaskan trip. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE /n aviator and his passenger may be only three feet apart, yet they cannot converse without the use of telephonic apparatus of special design. Telephones on Fighting Aeroplanes to Talk Over Three Feet Military flying machines usually carry two men—a navigator and an observer who must also work a machine gun when he has to beat off a meddlesome enemy-aviator. It is hard—almost im- possible—for the observer to communi- cate with the navigator because of the motor’s deafening roar. Hence, it was found necessary, even before the present war, to strap telephone sets on the heads of the men in flying machines. Turner, the inventor of the dictagraph, has de- vised a special loud-speaking telephone for the use of men in the air, an instru- ment of extraordinary power; which has been recently adopted by the Russian and Italian air fleets. Since everything must have a name Turner calls his in- vention an “aviaphone.”

Page 58

SS eS ae a a eae 454 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE The mouthpiece is large, and is held in position by a plate strapped about the chest. Two receivers are used. They fit under the helmet. The instruments are very sensitive, and magnify the sound, so that it is not drowned by the motor. Floating Metals If a small piece of iron—a straight piece of wire, for instance—be greased, it can be made to float on water. Ap- parently the grease prevents the break- ing of the surface of the water, and the iron lies cradled in a slight depression or trough. In recent experiments with rods and rings of iron, tin, copper, brass, platinum, aluminum, German silver, etc., it was found that all metals, even the heaviest, will float on water when their surfaces are chemically clean. A perfectly clean piece of copper or platinum wire, for example, forms a trough for itself on the surface of the water just as if it were greased. The same is true of a small rod of glass. The floating is due to a film of air con- densed on the surface of the glass or metal. Why? If the rod be heated to redness, cooled, and immediately placed on water, it sinks. But if it be exposed to the air for a short time it floats. PEACE FLEETS OF THE UNITED STATES HE U. S. Government has its peace a: fleets as well as its war flotillas. They carry no guns, for their purpose is constructive, not destructive; yet they are com- manded by some of the ablest officers in the service and are active- ly engaged for many months of the year. The larg- est of the peace fleets are main- tained on the Upper Mississippi River. If all the several hundred steamers, barges and crafts of various other kinds comprised in these peace fleets should assemble and move down the great river together, they would make quite an imposing spectacle. It is the work of the peace fleets to make the wandering Mississippi stay put in one main channel — a channel so deep and wide that it will afford easy passage at all times to the big freight and pas- ESS == A Government scow eng oe stones on a n to agg ned the senger water om un- dermining the steamers n shore. the north to oval: The build- St. Pau 1. ing of a dam. They are = accom=

Page 59

ee eee ‘ RIE AES oes comers % POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE One of the peace fleets of Uncle Sam engaged in keeping the treacherous Mississippi River under control and insure free navigation to the many steamers that ply its waters. plishing this by digging up and carrying off sand bars, pulling snags, reveting hundreds of miles of banks that wash and send sediment into the river, and build- ing thousands of dams from the shore into the channel to turn the spreading waters and keep them flowing in one main course. The river is divided for work be- tween St. Paul and St. Louis into seven divisions with a resident Army Engineer on each division and a fleet consisting of three steamers, three quarter boats, two dam-building barges, a riprapping outfit, a pipe line dredge and 25 to 30 barges for hauling. Since much of the work is done at too great a distance from towns to allow the employees to go ‘back and forth, the boats are fitted up as a home for them. Two big double- deck quarter boats are used by the labor- ers. A third is the home of the Army Engineers and their assistants and has a suite of modern offices in addition to living and sleeping quarters. As soon as the ice moves out in the spring the seven fleets leave winter quar- ters and take up the work of dam build- ing at different points on their divisions. The quarter boats tie up at the shore at the place of construction and the work boats and barges ply the river nearby. A third of the contract to make a six- foot channel to St. Paul that the War Department has undertaken is already achieved, and the engineers in charge of the fleets are confident of the ultimate accomplishment of the whole project. Blasting Coal with Water in German Mines In German coal shafts there is being ‘practiced a method of mining that is said ‘to do away with dangerous blasting, | while also avoiding much of the risk of spontaneous explosion of coal-dust. Deep holes are bored in the coal and water is introduced into them by pipes under heavy pressure. The water finds ‘its way through the coal fissures and opens them up until the mass is loosened, “when it is readily removed while wet without any dust or the use of any tools other than a light pick and shovel. A Plant That Made a Seat Out of a Millstone. Some years ago a huge millstone which had been used in a South Dover, N. Y., mill, was dis- carded. It lay on the ground for a long time. One day a tender plant poked its head through the hole in the center of - the stone and grew up with it. | |

Page 60

f | \ { } tH 456 The Real Cost, of a College Education Statistics have recently been given out by the University of Wisconsin which show the average cost of a four-year col- lege education, both to the pupil and to the taxpayers. According to these fig- ures, it costs $211.65 to give each student instruction for a year. Of this amount, the taxpayer is forced to pay $149.05, the rest being made up by state and federal grants, special fees and gifts. In addition to this sum, the pupil has to pay his share of the expenses, for board, clothes and incidentals. This av- erages about $300 a year. Another item to be considered is the value of the time lost in college when the student might be at work and earning money. This might average another $300 a year. Hence, the average cost of a college education amounts to $800 per academic year, or $3,200 for a four years’ course. A Railway Lunch Counter for Golfers For the convenience of the hurried business man who is often confronted with the necessity of choosing between a hasty lunch or the possibility of miss- POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ing his train to the golf links, a middle western railway has added to its “Golf Special,” a first-class train leaving Chi- cago about noon-time for Waukegan and the golf links, a lunch car which is a model of comfort, cleanliness, and ef- ficiency. A lunch counter which extends nearly the full length of the car is fitted with twenty-seven comfortable revolving seats. A Treasure Caravan in New York The sight of twenty-five gold-laden automobile trucks, manned by numbers of men carrying repeating rifles and escorted by a cavalcade of mounted po- lice, brought the traffic of Wall Street to an abrupt standstill recently. The trunks contained $50,000,000 to pay for war munitions and other supplies, of which vast sum $19,534,200 was natural gold. Thousands of spectators, who had read in their papers that morning of the tre- mendous shipment of gold from the Bank of England to J. P. Morgan & Co., stood spellbound while watching the treasure caravan roll past. The “Golf Special” train leaving Chi- *° for the golf ca, links at Waukegan includes a lunch- counter car

Page 61

Soveping British gold and securities amounting to the value of $50,000,000, twenty-five automobile trucks re- cently wended their way through the streets of New York ogg guarded by a cavalcade of mounted policemen and numerous men armed with The eyes of the guards, of the mount- ed police, and of detectives constantly watched the crowds. Some of the guards nearly collapsed from the strain, for they had been constantly on duty during the twenty-four hours’ journey from Canada to New York City. The treasure, which had been brought by a fleet of English warships, was for- warded to New York in a train of seven inchester rifles. steel cars. Three miles in front ran a dummy train of five cars, to receive any attack which might be made. Only five cars contained the treasure in the second train. The first and last cars were empty, so.as to serve as buffers in case of a wreck. Forty guards, armed with army rifles, vigilantly sat in the cars during the entire trip. Every pre- caution was taken.

Page 62

458 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE When it arrived at New York, the train was met by a strong detachment of police. The work of unloading the heavy boxes of gold from the train into the twenty-five covered automobile trucks was done with great care and dispatch. When the procession drew up before the doors of the Sub-treasury, an im- mense crowd gathered, but the large number of policemen and guards kept the curious at a safe distance. Checkers for the Government, J. P. Morgan & Co:, the express company which handled the shipment, and the British Govern- ment, carefully watched the unloading and the final opening of the boxes. Tobacco in Convenient Cartridge Form Sportsmen, tourists, and lovers of out- door life, to whom compactness must al- ways hold a peculiar charm, will consider this new form of tobacco and smoking- tube a distinct advance over the bulky old tobacco can and the bulging rubber pouch. “Tobacco cartridges” the new article has been named; for the roll of hin» Pe Do you admire compactness? Here is the latest examples of it: Tobacco made up in the form of es and smoked in a special holder. tobacco that goes to make this device has been cut transversely into a half dozen tubular plugs, each of which, ‘in the manner of a soldier’s cartridge, may be removed from the roll and inserted into a pipe or holder, and smoked just as readily as ordinary pipe tobacco, Thus has the military idea of the com} pactness and easy manipulation of a cartridge been adapted to the smoker’s enjoyment. Furthermore, these car- tridges, instead of containing shreds or strands of tobacco, are made of the en- tire leaf, which is rolled together and folded so as to obviate the drying up and wastage of the old fashioned cigarette, In this way, one’s pipe tobacco, or chew- ing tobacco, may be carried in a small, neat, sanitary roll; and at that silent after-lunch command “Light up,” one simply removes a cartridge of tobacco, loads his pipe, and puffs contentedly away. Although these tobacco cartridges may be smoked in any regular pipe, a smok- ing-tube is suggested for use with this form of tobacco. In principle, it is simply a cigar holder with a larger and deeper bowl, tapering towards the stem, so that the cartridge may be more tightly gripped until it is entirely consumed. One side of the tube, which is slightly curved, is flattened so that it may be placed on any flat surface, without the possibility of burning the varnish or contaminating the mouthpiece. An ‘‘All-Electric’’ Village Wildwood, a suburb of Toledo, Ohio, may be truthfully called an “all-electric” village. A large real estate development company has erected this little village of thirty houses, and has equipped them throughout to be operated by the latest electrical devices. Each house is fitted out with a large electric range in- stead of the old-fashioned cook-stove or range. The real estate company pur- chases the current for the entire village in bulk from the central station and re- tails it to the householders, who are thus able to obtain their power at a reasonable rate. Saran mm see

Page 63

NNR RAEN TO % Russian infantrymen and their machine guns captured by the Austro-German armies in the vicinity of Warsaw in Poland, The machine guns in this instance are mounted on small carriages to permit of ready transportation The Machine Gun—The War’s Greatest Terror LTHOUGH the Gatling gun—a weapon consisting of six connected barrels revolving on a common axis— was a remarkably efficient weapon for its day and wrought its share of havoc in the Civil War, and although the French used a mitrailleuse in the Franco- Prussian War—a gun with no less than thirty-seven barrels—it was not until Hiram Maxim in 1883 invented the auto- matic weapon that bears his name that we really had a true machine gun. In- genious Yankee mechanic that he is, Maxim hit upon the idea of making the “kick” of the gun perform every opera- tion from loading to firing. Before his time machine guns had all been operated by hand. When smokeless powder was discovered, the Maxim machine gun came fully into its own; for then it was possible to take up a concealed position and squirt death without betraying clouds of smoke. Since England has always had a war on her hands with some savage tribe, it was but natural that the British army should have given the Maxim machine gun its first practical test. In the Mata- bele campaign of 1893, the Afghanistan 459 war of 1895 and the Mahdi conflict of 1898, the frightful demoralizing effect of hundreds of shots discharged almost like water from a hose was convincingly demonstrated. During the Spanish- American war of 1898 and the Boer war of 1899-1902 the Maxim machine gun was first used effectively against civilized people. If there was any doubt as to the efficacy of the weapon—it had been argued by some conservatives that the gun was much too complicated and that it jammed too easily—it was dis- pelled during the Russian-Japanese war. Such was the deadly effect of the ma- chine gun in Manchuria that every European power at once increased its machine gun contingents. After the | Balkan campaigns of 1912 and 1913 it was generally conceded by military offi- cers that neither infantry nor cavalry could be effectively used without the assistance of the machine gun. The older Maxim models weighed about fifty-five pounds. By skillful de- signing the Germans reduced this to thirty-five pounds. The latest English Maxim model is still lighter, weighing but twenty-five pounds.

Page 64

460 POPULAR SCIENCE MONTHLY AND WORLD The machine guns used in the present European conflict all fire infantry car- tridges. The opening of the breech, load- ing, closing of the breech and firing are absolutely automatic so long as the marksman keeps his finger upon the fir- ing trigger. Since as many as six hun- dred shots may be fired in a minute, am- munition must be supplied in great quan- tities in an uninterrupted stream. To ac- complish this the cartridges are fed either in belts or in metal magazines. Such is the rapidity of the fire that the barrel becomes dangerously hot. Hence every machine gun of whatever make is provided either with a water jacket, like an automobile cylinder, or with cooling flanges and projections. For this reason machine guns cannot be built in a size and weight with that of the infantry rifle. Although Maxim’ s original idea of using the “kick” or recoil in order to perform the functions of loading and firing still meets with approval, machine guns are also in use in which, not the recoil of the barrel, but the pressure of the powder gases is made to operate the piece. The Hotchkiss and the French Berthier gun are perhaps the best exam- ples of this type. The inventor of this gas-pressure type is Freiherr von Odko- lek, an Austrian officer. All these guns are cooled by air with the exception of the French Berthier. A water jacket is the most effective means of cooling the gun. In order that the steam arising from the water may not betray the position of the piece, it is conducted by a hose either to a water container or to the ground, where it is quickly precipitated. Glycerine is added to the water in order to prevent it from freezing in winter. While air-cooled guns are free from the objection of gen- erating steam, they are necessarily much more complicated. Most of them are provided with pumps which automati- cally drive air through the passages to be cooled. The early machine guns were carried on wheeled carriages like ordinary field pieces. That proved a serious error, be- cause they were much too easily seen at a distance. Consequently tripod mounts were soon adopted. This tripod mount- "SS ADVANCE ing is usually detached from the gun during transportation. While on the battlefield the parts of a machine gun (tripod, barrel, ammu- nition, and so on) can be carried by int fantrymen, as the cover design of this magazine shows. Over long distances, however, the guns are usually hauled by animals or cavalrymen. The vehicles on which the infantry weapons are trans- ported may serve to carry part of the crew, as in the German army. In the French, Austrian, Japanese and Russian armies machine guns are carried by ani- mals entirely and the gun crews march on foot. In the German, Dutch, French and English armies cavalry machine guns are carried on vehicles and the gun crews either ride on horses or on the vehicles themselves. If only animals are used for transporting cavalry machine guns, as in the Austrian, Russian and Japanese armies, the gun crews are, of course, all mounted. Machine guns are carried by horses, mules, dogs, motorcycles, automobiles and sleds. Indeed almost any kind of vehicle can be employed for transporta- tion, which is speedy and not too con- spicuous. Aeroplane Secured by National Guard and Naval Militia In the midst of the agitation to equip the National Guard and Naval Militia of the various states with aeroplanes and flying boats comes the good word that the Naval Militia of the State of New York has already purchased a Curtiss flying boat of the latest type, and expects within a few weeks to hold practice flights in the Hudson River off Ninety- seventh street. Two members of the battalion are now at Hammondsport, N. Y., at the Curtiss factory, learning to fly and ac- quiring a thorough knowledge of the motor. The commanding officer of the bat- talion has been flooded with applications of the militiamen to be assigned to the aeronautical corps, and by a weeding- _ out process it is expected to find a group ‘of very efficient men to navigate the hydroaeroplane. POS ARIE ‘.

Page 65

{REFER Ser oA TBT FO a ‘. A Chance for the American Motor- Maker in China The American consul-general at Shanghai, China, believes that there is a large field for motor boats and engines in that country. He says that there are thousands of small craft plying the nu- merous inland waters and canals of China, and that few of them are equipped with motors. He hopes that at least a small percentage of this great POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 461 He fits a detachable motor to a small, flat-bottomed skiff and places the whole on a two-wheeled steel carriage. This he attaches to the side-car of his motor- cycle by means of a swivel bolt. His wife he disposes in a side-car and his fishing rod and lunch in his boat. Thus equipped, he sets off at top speed for any of the numerous ponds, rivers or harbors which abound in the neighborhood of Providence. This suggestion might well be followed by owners of motorcycles. How is this for an outing suggestion? A Providence man and his wife travel to a distant lake, river or seaside on a motorcycle and side car, hauling a fishing boat mounted on a light bicycle wheel truck be- hind them. Once they arrive at the water’s edge, the oat is slipped into the water, the gasoline motor turned on and they are off for a marine trip. fleet of boats will be equipped in the near future with American motors. A Fishing Boat Hauled by a Motorcycle Mr. B. A. Swenson, of Providence, R. I., has apparently solved the problem of how to own 4 motor boat on each of several far-away fishing grounds, and how to reach ‘them quickly in his leisure hours-—all on a moderate income. How Smoky Is the Air? An Instrument That Tells John Lowden, a Scotchman, has in- vented a “smoke tintometer,” which, it is thought, may be of use in prosecuting cases of “smoke nuisance.” It consists of a tube with a single eye- piece and two object openings. One of these is clear, but the other contains a revolving diaphragm in which are set five circles, one of clear glass and the } | } |

Page 66

-tom, which is 462 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE other four of tinted glasses correspond- ing with the standard tints of a scien- tific ‘‘smoke-chart.” In examining smoke-defiled air the diaphragm is turned until the tinted glass coincides in darkness with the air seen through the clear aperture. The various glasses are systematically numbered, so that a glance suffices to show the degree of de- fiiement of the air. The Evolution of the Self-Starter From a heavy, cumbersome and some- what undependable piece of machinery to a small, compact and _never-fail- ing unit is the evolution of the automobile self- starter in the last four years. The accompany- ing illustration shows graphic- ally the relative sizes of the dif- ferent . models, from the top machine, which is the 1916 mod- el, to the bot- that of 1913. The most recent model, that of 1916, weighs 14 pounds. Last year’s car car- ried a self-start- er weighing 24% pounds. In 1914 the weight was 34% pounds, well un- der half that of the previous model, which tipped the scales at 801%4 pounds. The starters mentioned are of the elec- tric type. a SSS Four years of the auto- mobile self-starter: Here are seen the electric self- starter machines of the past four years; the bot- tom one ing the first model and the other three, in the order shown, the succeeding ones. ~~ eee A Californian has invented a machine that pumps warm air out of a freight car and replaces it with cold air for the purpose of refrigeration. pe é ; Mysterious Zone of Silence Observed in Testing Distances Big War Guns Can Be Heard In making observation as to how far heavy artillery fire can be heard, scien- tists have discovered the unaccountable phenomenon of a zone of silence. AlI- though heavy detonations could be heard at distances of a hundred and thirty-nine and a hundred and forty-two miles, there was no sound audible at points from forty to one hundred and six miles away from the location of the heavy mortars used in the attack on Antwerp. At the point where the detona- tions could again be heard; that is, at a point about one hundred and six miles from the artillery, the re- ports and con- cussions were especially —_vio- lent and severe; for the ground trembled percep- tibly. This war is a scientific demon- stration of the existence of such a sound- less zone, reported in history. When Fred- erick the Great de- feated the Austrians near Liegnitz in 1760 zones of silence aided of the Austrians, sta- tioned nearby, did not hear the artillery fire, and, as a consequence, failed to come to the support of their companions, while other Austrian troops, much further removed, heard the cannon- ading and started for the scene of activ- ity, but arrived too late to be of any assistance. Zones of silence are often encountered in navigation. him. The main body - A ARAN RRM

Page 67

. ; LE RT What Is It? Boat or Automobile? A Vienese inventor, Ludwig Zeiner, has invented an automobile-boat or a boat-automobile, whichever you choose to call it. When it travels on land it looks pretty much like an ordinary racing car, for its hull is modeled on the lines of a torpedo car body. And when it crosses a river it looks for all the world like a motor boat for the same reason. If it were not for its propeller no one would suspect that the vehicle is as much a boat as it is an automobile. A four-cylinder motor of sixteen The ssengers in this auto- tmobile-boat are equally pre- pared to travel on land or water. horsepower drives the automobile-boat at a speed of forty-five miles an hour on a road and twelve miles an hour through water. There is no stoppage before the automobile takes the water. It plunges down even a steep bank and pushes its nose into the water at once. When dry land is reached again it climbs out just as readily. Other vehicles of this type have ap- peared in the past, but perhaps none have been as practicable. Forcing Plant Growth by Acetylene It appears that acetylene gas-is being utilized as an adjunct to the sun in the cultivation of plants. Plants subjected to the light of this gas are reported to attain twice the size of those left to the © tays of the sun only, and vegetables are POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 463 said to have attained dimensions double those unassisted in the matter of illu- mination. | The experiments were conducted dur- ing a period of three months and in a hot-house. This house was divided into two parts by means of a curtain, the cur- tain being hung in such a way that each half of the house received the same il- lumination from the sun. The beds on each side were exactly alike, not only in size but in location and contents. If a lily were planted in a certain part of a bed on one side, another of the same species and age was set out in the same part of the corresponding bed on the other. Inside the curtain an equipment consisting of thirty-five candlepower acetylene lamps was erected on one side of the curtain. Ordinary tin reflectors over each light threw their > _ _>__»=~_=SSSEEREBEEE On land this vehicle can at- tain a speed of forty-five miles an hour, and twelve miles an hour on water. rays downward upon the soil. The lights were operated whenever it was dark, the length of time varying from nine to fourteen hours, according to the period of daylight. The plants on the acetylene side were found, in many instances, to mature with twice the rapidity of those on the other side of the partition. Radishes, onions and several other species that develop their edible portions below the surface of the ground were found to have pur- sued their usual course, except that they grew twice as fast as those not placed under the influence of the acetylene light.

Page 68

Man-Made Limbs for Limbless Men N the stress of circumstances created by the great European war, France is already casting her glance ahead to- wards the future, when her maimed and ‘crippled defenders will return from the battlefields to their beloved hearths. France is aware of the great debt she has contracted towards her gallant sons; and even now, with the end of the struggle not yet in sight, a great movement is A collection of views of the French seieiane where limbs are being made in large quantities for the In the other views, showing the mechanism of artificial limbs, the first one illustrates the sliding bolt mechanism of a leg. While walk- ing the bolt is pushed down so as to engage with the catch in the lower member, the -* men who have been maimed while fighting t nent rigid. e battles of the Republic. en the wearer of the limb wishes to sit down, the bolt is pulled up so as ding the artificial leg. The second sketch shows a typical artificial arm as well as the implements French Republic is planning to provide her maimed sons with artificial legs and arms, so that the crippled veteran, far from becoming an object of maudlin sentiment or a hopeless pensioner, will actually be enabled to take his place in the trade or profession to which his in- juries limit him. If the social question of the readjust- ment of the cripple to his environment is WAIST BELT eaten — ee LEATHER SLEEVE used conjunction with it. The third view illustrates an artificial leg with the various parts indica under way to give to the crippled victims of the war the material and moral aid which they have so bravely earned. The a complex one, the mechanical question is more easily solved. For, given a good artificial limb, the armless or legless man 464 being thus to permit of

Page 69

can readily move about, easily take to an occupation, and be quickly enabled to F “stand on his own legs,” both in the physical and economic sense. Experts engaged in the making of artificial legs and arms for the French soldiers. So skillfully made are these limbs that in almost every instance become hopeless pensioners. above the knee. Although the ideal artificial limb is still to be devised, there have neverthe- less appeared several models in France | | a which approach a solution of the cripple’s | problem with a high degree of skill and efficiency. There are, of course, extreme cases of amputation, which even a per- fect artificial limb alone will fail to re- lieve. In the case of an amputated thigh, for example, no device can enable the patient to regain his normal walk. The | use of an artificial limb in this instance : is attended by a painful movement of the hip, making imperative the use of the old-fashioned wooden crutch. | Next, after the ordinary crutch, comes the use of the time-honored pestle-shaped ka a en ee ene POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE the maimed soldiers will be able to earn a livelihood and not he sketches showing the mechanism of the artificial limbs are as follows: The first represents the artificial leg devised by de Beaufort for cases where the leg has been amputated The second indicates the mechanism of the leg designed by Professor Delbet, which operates on the principle of the swinging parallelogram. The last is a leg of American manufacture. The leg is thrown forward for a new step by means of a spring 465 stump which, on account of its ugliness, is not very popular. Yet in its lightness and in its ease of management it possesses a decided advantage over the artificial leg. Cripples provided with this device, especially those whose opera- tion has left them a long stump, have been known to run and jump, to mount stairs rapidly, and even to ride a bicycle. The most popular and the simplest mechanical leg is that made by de Beau- fort and used in cases where the amputa- tion has been made beneath the knee- joint. The portion above the knee is strapped around the thigh, which is sup- ported by two wooden or steel rods, jointed at the knee and extending down along the tubular leather leg into the wooden foot. A steel spring is concealed within the leather leg-piece so as to per- mit the foot to conform with the walking

Page 70

| | 466 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE movements. This device earns its popu- larity because it enables its wearer, after several weeks of practice, to resume a gait that is almost completely normal. De Beaufort’s artificial limb may be employed in cases where the amputation is above the knee, but here the knee joint ceases to be free. Consequently, an arti- ficial knee-joint must be supplied, either in the form of an ordinary locked bolt, or in the more improved form of an ad- justable bolt. In the former device, the head of the bolt is permanently held in its socket, so that the cripple is required to walk with a stiff, sidling gait. "When he desires to sit down, he must press on the upper lever, which thereupon folds back and permits the artificial leg to bend at the knee. In rising from a sitting posture, the bolt becomes erect through the rising motion. The adjustable bolt differs from this device in that it permits the leg to articulate during walking ; but it is of such an extremely detailed con- struction: that it is recommended only for those cripples who are capable of concentrating their attention for long periods of time. Internal springs, or even two stout rubber bands connecting the thigh and the leg, carry the latter forward when the whole limb is off the ground. The adjustable bolt may be also used to make the entire limb rigid, by simply allowing the bolt to slip into the socket. Still another artificial limb has been devised by Prof. Pierre Delbet. In its operation it employs the principle of the swinging parallelogram. The wooden foot, which is attached to a stirrup- shaped knee by means of two pivoted steel rods, is carried forward by the springs whenever the body is brought forward, and the limb raised from the ground. Owing to its great flexibility and adaptability to almost any movement, it is by far the most desirable limb for a cripple who seeks speed in his activities —and there are many in this class. American made artificial limbs are also found on the French market. One model. has a wooden foot which is articulated by means of a four-pointed steel bolt, which, with the aid of springs concealed in the hollow leg, allows a free and jointed movement in walking. Since it is made entirely of wood, it dispenses with steel supports and a leather tube; hence it gains in lightness. The Ameri- can manufacturers will doubtless find a ready market for artificial limbs in Europe after the war. Not so much attention is devoted in France to the manufacture of artificial arms and hands, for they are considered mezely as esthetic apparatus with which practical and useful movements are im- possible. One form of limb is used in cases where the forearm has been ampu- tated. The thumb and the index finger are both jointed; and by means of two strings attached to the steel frame, they ~may be extended so as to grasp small objects. The entire movement for providing cripples with artificial limbs has become one of national importance in France. Numerous associations with this object in view have been formed in many sec- tions of the Republic. And the fact that they are patronized by the civil and mili- tary leaders—the famous General Pau, for example—bids fair to insure the suc- cess of the movement. A Jail on Wheels Prisoners of Atlanta, Georgia, who are lucky enough to find themselves in the “honor squad,” will have reason to con- gratulate themselves that good behavior has earned for them comforts denied convicts in most jails. The Fulton County commissioners decided that they would have no unsanitary convict canips and ordered a fleet of specially designed con- vict cars. Gaze upon them in the ac- companying pictures. They are comfort- able padlocked cells on wheels. Thirty- six of these cars will form the nucleus of Atlanta’s “honor camp.” Each car holds from twelve to eighteen

Page 71

men, and each man sleeps on a wire spring bunk. Forced ventilation keeps the air pure, and a heating system is employed for cold weather. In rainy weather the cars are fitted out with tents to shelter the prisoners. The camp can be moved on short notice—men and all. It re- duces the guards required ordin- arily and protects against disease and vermin. The Atlanta honor camp will have many modern facilities, in- cluding a special dining tent, reading room, carpets, spring cots and other conveniences not usu- ally found in places of detention. POPULAR SCIENCE MONTHLY AND THE WORLD’S ADVANCE 467 A traveling prison with awnings attached to keep out the rain during inclement weather. Oil Worth $1,200 a Barrel at Hatteras Post Office, on the nar- row sand strip between Pamlico Sound Probably the only porpoise-oil factory and the ocean, about six miles below in the United States is that established Cape Hatteras and near Hatteras Inlet. When the catches are hauled to the beach, they are killed and skinned for their hides, and the blubber is removed Although this may seem like a box car for live stock, it is in reality a most comfortable and sanitary form of prison mounted on wheels. The “honor squad” prisoners of Atlanta, Ga., while working outdoors are using thirty-six of these cars as sleeping quarters.

Page 72

Se a SR 468 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE from them. The hides are salted down and sent in the green state to tanneries in the North to be tanned and made into leather. Porpoise hide is used for shoe strings, for pocket books, and for vari- ous other purposes. The oil from the blubber is tried out at the factory on the beach, and then sent to New England for refining if found of sufficient value. Photos Copyrighted International News Service A most realistic trip in a sub- marine is one of the attractions of the Panama-Pacific Exposition’s Zone, or amusement concession district. After a trip in the sub- marine the passengers are ded and guided through mysterious caves. A huge whale is one of the features of the attraction. The head oil, valuable because it is used for oiling watches and other deli- cate machinery, is obtained from the marrow of the porpoise’s lower jawbone, and from a small quantity of blubber found between the snout and the blow- hole. In the manufacture of the oil this blubber and the marrow are mixed. The production of head oil may range from half a pint to a quart from one por- poise. Refined porpoise oil for jewelers’ use is worth from $900 to $1,200 a barrel. The body oil obtained from a porpoise amounts, generally speaking, to thirteen or fourteen gallons. To produce a bar- rel there is required the oil taken from about four porpoises. This oil, which is employed for various purposes, brings far less than the head oil. Taking an Imaginary Submarine Trip at the Panama-Pacific Exposition Exhibitors in the “Joy Zone,” the amusement district of the Pa- nama-Pacific Exposition, have spent fortunes in devising new methods of amusing the public. One of the most novel of the many attractions that line both sides of the “Joy Zone” is “The Submarine,” an exhibit which offers to its patrons an illusory under-water excursion in a boat to view the equally illusory mys- teries of an illusory Sargossa Sea, Blue Grotto of Capri, submerged icebergs, and Davy Jones’ Locker. The imitation submarine, when it has received its complement of fifty pas- sengers, is ceremoniously made airtight. It lurches forward and thus apparently starts on its under-water trip. On “ar- -riving” at “Nature’s Labyrinths,” the submarine lands, and the visitors, ac- companied by guides, start on-a tour of the passages, which honeycomb the con- cession. One of the many novelties of the stroll consists in walking through the bowels of a papier-maché whale. It is obvious that the “submarine” remains stationary while the scenery moves by.

Page 73

Use Your Motorcycle or Auto Tires as Life Preservers Two young English girls have recently been giving many interesting experiments at Westcliffe-on-Sea, England, to show the value of an automobile tire as a life preserver. They affirm that the buoy- ancy of an ordinary tire is much greater than that of life preservers, and is so flexible that it allows of the limbs being used for any swimming stroke. The ac- companying illustration shows one of these girls resting after a long swim. She is supported by the tire as comfort- ably as though she were reclining in a hammock. : Minimizing Eyestrain at the Movies Although makers of motion-picture ap- paratus are busily seeking a means to eliminate the fatiguing flicker which many patrons of the movies find so try- ing to the eyes, nevertheless some ocular discomfort still makes itself felt even in motion picture houses of the most mod- ern kind. For this reason, the optical device seen in the illustration is designed for the use of picture playgoers whose eyes are sensitive to the flicker of the films. It POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE To eliminate the eye strain due to the flickering of motion pictures, an inventor has recently devised this simple contrivance. consists of a lorgnette-like piece of stiff black paper, with a bridge made to fit the nose of the wearer. Each eyepiece contains a narrow slit, about 1/2oth of an inch wide. The size of the slit can Automobile or motorcycle tires make excellent life preservers. Not only do they possess great buoyancy, but their size and shape make possible the full freedom of the limbs.

Page 74

470 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE be varied simply by two movable shut- ters to suit the vision of the individual using the instrument. The shutters can be raised or lowered over the slit. When this device is held before the eyes by means of a pivoted lorgnette handle, the effect of the narrow slits is to cut down the amount and intensity of the light rays which enter the eyes, and thus prevent the eyestrain which the flicker usually causes. We would call it a motor-skate; the inventor calls it a mon-auto. At any rate, it is a cross between an exag- gerated skate driven by a gasoline en- gine and a diminutive motorcycle. At a recent dinner party given by prominent society people of Toledo, a novel feature was introduced. Fach guest cooked his own dinner by elec- tricity. An electrical device has recently been patented by which the number of pas- sengers entering a street car is automatic- ally recorded. This device may obviate the necessity for the old-time fare regis- ters. A Forty-Five Pound Miniature Motorcycle A sensation was recently caused in the streets of Baltimore by the sight of a man being rapidly propelled through the traffic upon the smallest motorcycle ever built. The seat of this tiny machine was little higher than the seat of an ordinary chair. A one cylinder motor furnished plenty of power, and when the driver drew up in front of his resi- dence he picked his machine up in one hand and carried it into the house. Hugo C. Gibson, of New York, the inventor of this new departure in the automobile © field, became known to the public when he exhibited his “motor skate” at last year’s automobile shows. His new machine, the “Mon Auto,” much resembles the motor skate, except that it is larger and allows the rider to sit down. The rider sits on a saddle sup- ported on the rear end of a cantilever spring, and places his feet on two rests, one on each side of the front wheel forks. He steers by a novel handlebar arrangement to which the motor control is attached in such a manner that push- ing the handle forward increases the speed, while pulling it back decreases it. The Mon Auto is 48 inches long, 9 inches wide, 18 inches high and weighs 45 pounds. Oil and gasoline for 75 miles are carried in the tubular steel frame,

Page 75

and the handlebars and frame fold up to permit of easy carrying and storage. A 2'4-horsepower motor, geared in the ratio of 5 to 1, drives the Mon Auto at a maximum speed of 25 miles an hour. Mr. Gibson claims that his invention should be extremely valuable for mili- tary purposes. The car weighs less than a soldier’s ordinary equipment and can easily be carried over fences, streams and ordinary obstructions. It offers quick and cheap transportation, while its cost must necessarily bring it within the reach of the multitudes. The Smallest Motor in the World Ivan T. Nedland, of Hillsboro, N. D., deserves a medal for painstaking labor. He has made a tiny dynamo, weighing but five and a half grains, probably the smallest in the world. The length of the motor over all is 19/64 inch. The height is 11/64 inch. The commutator has four segments of gold, each segment insulated with mica. Fibre is used as an insulator between the commutator and shaft, and between the end pieces and commutator. The com- mutator is built as it is on large ma- chines; no glue or cement was used in its construction. The diameter of the commutator is .0045 inch. It is mount- ed on a pivot steel shaft, .oo9 inch in diameter. The armature has four poles, and is wound with silk-covered wire. Between POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE S) i | POOLE 3 se Here is the latest claimant to the title, “The small- est electric motor in the world.” Have you ever seen a smaller one? the armature and the yoke are two field coils. The brushes are of silver and are but .oo12 inch in diameter. The springs for the brushes are .004 inch in diam- eter. Fishing a Ten Thousand Dollar Loco. motive Out of a Lake It can be statistically proved that the safest place in the world is in a Pullman car and the most dangerous, your own home. Only once in a while something goes The locomotive was valued at $10,000, so the railroad officials figured that it was worth while to recover it from the bottom of the river. to it, Divers were sent down to inspect the engine and fasten the wire cables A wrecking crane soon lifted the locomotive onto the bridge an placed it gently on the rails.

Page 76

i l] { 472 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE wrong on the best regulated roads. The locomotive shown in the picture ran off the bridge and plunged into the river at Bay City, Michigan—one of these “once in a while” occurrences. To-day all railroads have as part of their equipment cranes, known as “wreckers” and regularly employed in construction work of the heavier kind, such as bridge building and handling turn tables. These cranes are always ready to be rushed to the scene of an ac- cident. Equipped with a set of tools designed to handle derailed or damaged cars and locomotives, they lift.an over- turned car and place it back on the rails or else carry it to the shops for repairs. As soon as the accident pictured oc- curred at Bay City, a wrecking crane was sent for. It was found that the seventy-five ton locomotive lay in deep water and that it would be necessary to send divers down to attach the lines, After the divers had inspected the loco- motive they came up and selected the tools they desired to use, comprising dif- ferent kinds of wire rope slings, hooks, eyes, clevises, hoist beams and yokes. Then they went down and attached the slings and lines to the locomotive. In three hours the submerged locomotive was once more on the rails and very little the worse for the experience. Getting it out of the water so promptly saved it from damage by rust or prolonged con- tact with the river bottom. Marconi is said to have invented .an apparatus to destroy aeroplanes by par- alyzing their motors wirelessly. The de- tails are not yet known to the public, NEW TASKS FOR THE AUTOMOBILE HE motor car of today is not only~ a pleasure car or a truck, but it is a house-mover, a sleeping car, a traveling bank, a freight loco- motive, a plow horse, a fort on wheels— in fact, its versatility een (ht would have surprised even the most im- aginative of inventors in the early days of motor locomotion. The great tractive power of a five-ton truck is utilized to Below: The interior of the City of Detroit paymaster’s car. The car body is of steel to insure the huge sums of mon carried against theft. In the oval: A motor truck doing duty as shunti loco- motive. At the right: Not only is this automobile used for pleasure wunaanee. * daring wotien hours its owner uses it to drive a complete woodworking equipment. move a house in ee ee eee

Page 77

POPULAR SCIENCE MONTHLY Above: A complete camp- ing equipment which is car- ried in an automobile. The car also furnishes electric light at night. In the cir- cle: Moving a house by means of a motor truck. —— a single working day by a Los Angeles house mover. Using a 1,000-foot cable, a block and tackle, and a convenient tele- graph pole, the powerful motor pulls a house on its support of heavy iron wheels about as fast as a man can walk. A most comfortable and complete “sleeping car” is the invention of a West- erner. The seats of a touring car are arranged so that they may be made into a comfortable berth, the bedding of which is carried in a compact roll on the running board. By means of a tent, a dining room and kitchen may be added to the complete and compact apartment. The traveling bank is now a familiar sight on the streets of many of our large cities. The City of Detroit employs an efficient example of this type of car to pay gangs of laborers in outlying sections of the city. The body is of steel, and is _ proof against “hold-ups.” The interior is fitted as a cashier’s office, with desk and swivel-chair, filing cabinet and safe. The pay envelopes are disbursed through a barred window in the rear, where the workmen line up to receive their wages. This car has been found extremely eco- nomical, for it handles the great amount of work more expeditiously and requires less time than did the former system. A Western concern dispenses with the use of a switch engine for shunting AND WORLD’S ADVANCE Above: A touring car fitted with a hammock so that its occupants can spend their nights in comfortable sleep without the necessity of putting up at expensive inns or hotels, freight cars about upon the spur con- necting its factory with the main line. It was found that a string of seven freight cars, loaded with heavy metal work, could be easily pulled by a five-ton truck just as efficiently and much more cheaply than could the heavy and cum- brous switch engine. The truck has not only been doing all of the work, but has also been in almost continuous service for general duty. The Carefully Made Champagne Bottle The champagne bottle must, in all its parts, be constructed of an almost math- ematically even and heavy thickness. Its glass must be perfectly smooth and un- affected by the acids contained in the wine. Its neck must be exact in every particular, to insure perfect corking, and with no grain or projecting points on the inside. Such progress has, within the last ten or fifteen years, been made in the man- ufacture of these bottles, that, where formerly a breakage of five per cent. was deemed small, at the present time the breakage does not exceed one per cent. Despite the perfection as to strength reached in the production of champagne bottles, the strain upon them

Page 78

474 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE caused by the intense pressure they sus- tain and the repeated handling they un- dergo weakens them to such an extent that it is considered unsafe to use the bottles a second time. With the exception of smaller houses making the cheaper brands, champagne manufacturing firms place their wine in none but entirely new bottles. The American Consul at Rheims reports that four glass-blowing establishments in that city, and several others in the vicinity, make bottles almost exclusively for champagne. They work night and day, in three shifts of eight hours each, and turn out about 40,000,000 bottles annu- ally. Photographing a Bullet in Flight The first successful photographs of the flight of shot were made by Ernst Mach in 1885, according to Prof. Dr. F. Neesen in Umschau. A point of utmost importance in un- derstanding the flight of shot is a knowl- edge of the condition of the air, for the resistance of the air robs the shot of the greater part of its energy. Mach made use of the fact that light is deflected in varying degree by masses of air of vary- ing density. Thus it became possible to note the difference in the density of the air surrounding the shot. The eye can see this distinction in the wavering cur- rents of air that rise over a hot steam radiator, but is not quick enough to see it in experiments with shot. But the camera can see it. A bullet traveling through the air displaces the air in much the same manner as a ship plyin through water. A bow wave is formed in front o the bullet, while in its wake are waves and bubbles caused by the partial vacuum formed. W hat the camera sees the accom- panying pic- tures reveal. A bullet in the air pro- duces about the same ef- fect as a sub- marine boat in water. In front is a strong bow wave, caused Another view of a rifle bullet passing through the air at high by the com- speed. pression of the air, and behind the projectile is a rarified space in which strong eddies arise. The bow wave is actually a wave and not compressed air carried along by the shot and spilled laterally. Ifa resisting body is placed at the spot passed by the shot that is taken on the plate, the picture shows the way in which the shot pierces this body or blows it up. Such photographic studies are of great value in judging the effect of shot. For example, explosive effects which formerly were believed to arise from the use of dum-dum bullets have been ex- plained by these photographic exper- iments. A Space Saving Table One of the most congested districts in New York City is that known as Chel- sea. Here a day nursery has been es- tablished by the municipality, so that chil- dren of tubercular parents may be cared for during the day. The children are given plenty of fresh, wholesome food and are kept in the best of condition. The nursery became so crowded that at meal times it was necessary to feed the children in two shifts, and, needless to say, the ones who had to wait did not like it. The supervising nurse finally solved the problem simply and _ ingeni- ously. She had the centers cut out of the low, round tables at which the chil- dren are seated. Now they all eat at the same time, the very little ones have the east zZ

Page 79

inside seats and the older children the outside, and there is an air of general satisfaction in the nursery. The suggestion offered in this article might well be followed by anyone con- fronted by the same problem as the supervising nurse in this case. Since the entire surface of a table is seldom neces- sary, why not cut out the center? ‘POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 475 Most commercial ammonia is a by- product of gas manufacture. When the coal is placed in the retort at the gas plant two products result from its dis- integration. One is the gas which is piped to our homes and used. The other is a liquid which contains a strong percentage of ammonia. This liquid is placed in vessels in In this day nursery space is at a premium. Using an ordinary table it was found necessary to serve the children in two shifts, which was bcth impracticable and resulted in dissatisfaction among the youngsters. The supervising nurse finally hit -_ the table, so that children could sit bot! How Ammonia Is Made A great many unthought of processes lie back of the average article in common use. A great deal more is involved in the making of a piece of ice, for instance, than the machinery and process of the ice plant. One of the things essential to ice-production is ammonia. The manu- facture of this cold-producing chemical is no less interesting than the making of the ice itself. n the idea of cutting away the center portion of around and inside the table thus formed. which it is allowed to stand and settle. This brings the liquid portion to the ex- clusive occupation of the upper level, the solid substance having settled to the bottom. The free ammonia is driven from the liquid by steam. A mixture of lime with the contents of the vessel serves to separate the fixed ammonia, and this is then driven to itself by an- other application of steam. The steam collects the ammonia and gases and, together with them, it is

Page 80

‘sulphuric acid. 476 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE forced through leaden tanks containing In this the ammonia takes the crystal or sulphate form, and may be removed from the tanks by means of ladles. The ammonia not taking the crystallized form is gathered in water, from which is made the liquid ammonia or hartshorn in common use. Free ammonia is not found in Nature and must therefore be produced by arti- ficial means. There are other methods of manufacture, but the one here de- scribed is probably the only one in any large use. Ammonia, of course, has many uses other than household use and ice-manu- facture. It is largely used in dyeing, calico-printing, making coloring sub- stances, and in chemical compounds. Measuring Telephone Talk A new device, designed to aid a per- son to gauge carefully the time spent in a long-distance telephone conversa- tion, has been invented not for the benefit of the _ tele- phone com- pany, but for the benefit of telephone con- versation- alists. The makers of this imstrea- ment claim that toll calls average less than two min- utes per call, and that since three minutes of conversation are paid for, more than $60,000,000 is paid yearly for toll service that is not rendered. The talk-measurer is a small clock built on the principle of a stop-watch. The dial is marked off into minutes and their divisions, and the total revolution of the hand occupies six minutes. The Long distance telephone conversation is expensive. In order that a business man may converse to the full I'mit of one call this talk-measurer has been introduced. three-minute mark is emphasized by the announcement in red letters, “Excess be- gins.” When the connection is made be- tween the speakers, a lever is moved, and the clock starts to record the time. As soon as the conversation is completed, the clock is stopped. The time consumed by the call is thus accurately registered, to be noted for reference in case of over- charge by the telephone company. Rendering a Bank Safe Burglar Proof A most dangerous weapon in the hands of safe “crackers” is the oxy-acetylene blowpipe, by which the hardest steel is consumed like butter. This proc- ess seems to meet the desires of the safe burglars better than any other. So it is not surprising that a few years after its invention the fusing burner was adopted as a burglar’s tool. The first time it was used by burglars was in April, 1907, in the robbery of a bank in Antwerp. The rooms of the Antwerp bank were on the ground floor of a hotel in which t he thieves rented a room directly over that contain- ing the bank’s safe. Their “baggage” con- sisted ofacom- plete apparatus for generating acetylene, two cylinders of compressed oxygen, a blowpipe torch and other ne- cessary tools. On a holiday, when no one was in the bank, they sawed a large, square hole in the flooring of their room and with the aid of a rope ladder entered the part of the bank con- taining the safe. First they hung two thick blankets on the two sides of the safe, thus forming a kind of tent, to pre- vent the bright flame from being seen

Page 81

RRR MOY oe NA NO outside. They then put on automobile POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 477 A new armor-plate steel has lately been glasses to protect their eyes from the invented at the Krupp plant in Germany p aw: © © = ful light and went to work. In a few hours the thieves had melted out the piece of heavy plate containing the lock, drawn back the bolts, and opened t he safe. The booty gained was over 25,000, it is said. At first there seemed to be no pro- tection against the fierce heat of the oxygen flame. Safe- makers tried various chemical fill- Lined with concrete and provided with a clever construction of which 1s practi- cally unmelt- able as a safe - steel on account of the great amount o f time and gas necessary for its fusing. This new in- vention is not Co xt Op rk= sively em - ployed as yet, so that more interest at present at- other method of protection that has been adopted of late years. In this method the safe is so made. that it is impossible bolts, this type of safe is claimed to be as proof against burglars to reach the ings behind the exterior plate to generate poisonous or explosive gases as soon as the smallest opening is made. Packings were also devised, so compounded that their gases would ex- tinguish the flame of the burner. One manufacturer proposed the use of a thick paste that hardens in the air and instantly stops up the hole. There are also safes that have a plate of copper in back of the exterior plate. The current of oxy- gen striking it causes the copper to be covered with an incombustible copper ox- ide, thus making it difficult to reach the inner walls of the safe. There are draw- backs, however, to all these methods of prevention. The copper plate can be pierced with relative ease by a drill and chisel. Moreover, poisonous gases give no absolute protection, as there are de- vices for overcoming these poisons, such as the smoke helmet and devices for in- haling oxygen. as any type yet devised. bolts of the lock. These doors consist of five steel plates, set one behind the other, and bound to- gether by powerful steel bolts. The bolts are screwed from behind into the exte- rior plate and are distributed over its en- tire surface at short intervals. In this arrangement a short bolt always stands between each set of two long ones, so - that the heads of the bolts are arranged alternately behind the intermediate plate and the covering plate. The space be- tween the plates is filled with cement to cover the’bolts entirely. Behind the heads of the bolts and firmly united with the frame of the doors are the steel plates, which make it impossible to drive the bolts through to the interior. It would take-a burglar more than a whole night to open this safe, and it would require more gas than can be compressed in the pair of tanks that a burglar would carry. taches to an-.

Page 82

Fighting the Menace of Shifting Sands By William S. Birge, M. D. AST tracts of land are annually in- undated by sand drifts. What the blizzard, the cloudburst and the tornado ‘ are to cities high winds and storms are to the seashore and other sandy stretches. Great sand drifts bury railroad tracks and sweep over farms. Sand dunes ap- pear where yesterday was a plain. Nature has provided an ample remedy for her own curse in the form of certain grasses that. grow in sandy _ wastes. Wherever they are found the sand is held together. It is possible to select and transplant these grasses so that the most stubborn and lawless beach may be held in control. By their aid the people of Holland have finally secured their hard-earned country against the constant efforts of the North Sea to devour it; and after a constant struggle of nearly a hundred years France has transformed the desolate shores of Gascony into fer- tile fields and forest lands. The Government at Washington has for many years, through the Department of Agriculture, conducted an investiga- tion regarding the nature of sand grasses. It has learned what other countries have accomplished with them and has brought from all lands hundreds of specimens representing every known variety not grown wild in this country. It has ex- perimented with them under all possi- ble conditions and made trial plantings in the sandy wastes along the shores of Washington, California and Florida. These extensive investigations do not stop with the mere binding of the sand along the coasts. In the eastern portion of Oregon and Washington, and in other sections of the interior, are large areas so sandy as to be of little or no value. In some places the soil consists of pure sand,-the shifting of which has devas- tated miles of arable lands, buried trees and destroyed whole forests. In the vicinity of Provincetown, Cape Cod, is what is known as the “buried forest,” The planting of sand grass has done much to prevent the shifting of sand which, in many instances, proves disastrous. Not only does sand grass serve this all-important function, but, it is claimed, the productiveness of the sand is also improved. 478 ero ee ae Somat

Page 83

aeRO called so because the tops of scrub pines are just being visible on the surface of the dunes. The two most important sand-binding rasses are the marram, or beach grass, and the sea lyme. Another grass which is useful as a binder and which is found on the Atlantic coast south of the range common to the marram and lyme, is called “little panic grass.” Growing in the sands along the western coast of America is a species of Poa, which has been called seaside blue grass by the Bureau ot Agriculture. But the most promising of all the grasses so far dis- POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 479 covered by the bureau, and one only re- cently obtained is called the sand blue grass. It is a native of the interior, ap- pearing in the arid places of the South and West, and it serves as forage where the more nourishing grasses will not grow. The fact that sand-binding grasses may be developed having nutritive quali- ties shows to what extent the experiments have been carried by the Agricultural Department. It has also been proven by the bureau that pure sand, if planted with these, may become transformed into a more productive soil. aon RETURN OF NATURAL INDIGO—ONE EF- FECT OF THE WAR ERMAN chemical science, about twenty years ago, killed an import- ant agricultural industry—raising the in- digo plant for its dye. The industry was not small. It was measured by many millions. of dollars, and it produced among the planters of India many so- called indigo nabobs. China devoted large acreage to the plant. A century ago Louisiana tried to raise the plant, only to find that sugar cane paid better. The manufacture of this fine blue dye, so essential to the world, tempted the research chemists of Germany. For thirty years they spent much money and effort trying to make real indigo in the laboratory. Some methods were devised, but they were too expensive. It was not until about twenty years ago that success was achieved. Naphthalene (the sub- stance of which so-called “camphor balls” are in part composed), an almost worthless by-product from the distilla- tion of coal tar, was used as the starting point. The accidental breaking of a glass tube threw some mercury into an experimental vat and caused a successful reaction not before obtained. Quick appreciation of what had happened gave the chemist the key to the problem, and artificial indigo, equal to the best natural, was made more cheaply than before. The planters were driven from the field, figuratively speaking, and now twenty million dollars worth of artificial indigo is sold every year. The Hindus and Chinese turned their indigo acreage into grain fields sadly needed in such famine- stricken countries. So this chemical tri- umph was a blessing to the world. About four hundred tons of the dye were exported from India last year, but five years ago the amount was double this. Last autumn the war prevented ex- portation from Germany of the artificial product, and the price rose 500 or 600 per cent., thus tempting the Hindu planter to increased acreage for the present sea- son. Some large producers are said to be in London negotiating with the Brit- ish government for a guarantee against loss in the future if they attempt to put the natural industry on its old basis. This strikes a popular note in the present state of the British mind on the subject of German dyestuffs. Even China has decided that the six and a half million dollars it pays Ger- many every year for synthetic indigo might be spent to better advantage at home. The war has cut off much of the importation. This means some privation to the Chinese, who have always been extremely fond of indigo blue.

Page 84

480 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE A Land Yacht and Its Transcontinental Voyage “The Gypsy Van,” perhaps the largest and most completely equipped motor car in the world, is now on its way across the continent with a passenger list of eight persons, as well as a crew of three, who are provided with as comfortable eating, sleeping and liv- ing accommodations as are to be found in most small yachts. This yacht on wheels is over 25 feet long—a greater length, in fact, than the familiar Fifth avenue ’buses. It is 71%4 feet wide, 13% feet high, and weighs between seven and eight tons. There are sleeping accommoda- tions for eight persons inside the body of the car, while the roof may ~ “Gypsy Van’—perhaps the largest and most com- pouly equipped motor car the world—which is now om its way across the North erican continent. It has accommodations for eight Passengers and a crew of three. aaa SS be enclosed so as to form a chamber for the two chauffeurs and the cook. Electricity, supplied by a generator, lights the interior of the car and oper- ates an electric range in the well- equipped kitchen, Food supplies suff- cient to last a week may be carried in cupboards and in an ice-chest which has a capacity of 100 pounds of ice, in addi- tion to storage room for perishable foods. “Gypsy Van”, with the kitchen in the back. ground. In the Circle: Front view of the hu , motorcar. the left: The uaa yacht under way. = ——— | A six-cylinder motor of about 60 horsepower is used, and with the special transmission which has been installed it is ex- pected that this gigantic van will be as flexible un- der bad road conditions as a pleasure car. There are nine speeds forward and three reverse. The gear ratio of the lowest speed is 6 2/3 to 1, and that of the highest is 82/3 to 1. The brakes are exceedingly powerful; the service brake acting on the rear wheel having a friction surface of 260 square inches. Before starting from New York the car was given a thorough try-out over rough roads and proved equal to its task.

Page 85

ae

AKI KCC GIAUG <2 aie oe

Wd ddd rte

An interesting exposition of the relationship between the human skull’ and its flesh. Scientists have made such a careful one exacting study of this relationship that they can reconstruct a face from almost : any sku ene Facial Features from the Skull HEN Shakespeare, in his impres- sive and uncanny Gravedigger Scene, causes Hamlet to recognize one of the skulls as having belonged to Yorick, the dead jester, he may have merely been providing his audience with a fantastic, over-imaginative _ thriller. But in the last century the scientist anat- omist has undertaken the almost im- possible task of demonstrating that all human skulls possess sufficient points of difference to enable him to reconstruct, by means of portraits and death-masks, an actual likeness of the face of the in- dividual who during his lifetime proudly bore the skull on his shoulders. To the layman, in fact, all human skeletons and skulls appear to be hopelessly similar; indeed, it is only in real life that we can distinguish, thanks to differences in facial characteristics, one person from another. But science has succeeded in reconstruc- ting the human face with nothing but the skull and a portrait or a death-mask to furnish the clues. The inspiration for this fascinating work of reconstructing the human face occurred as the result of a famous con- troversy over the skull of Schiller, the German poet. Upon his death, his body had been immured with twenty-two others in a vault in the cemetery at Weimar, Saxony. When, in 1826, this vault had to be emptied, the coffins were

so completely decayed that Schiller’s could not be recognized from the others. Accordingly, a comparison was then made between the twenty-three skulls and the only known death-mask of Schil- ler; and in the unanimous opinion of a large body of so-called experts, the larg- est skull was decided to be Schiller’s. Upon the subsequent discovery, how- ever, of a second death-mask at Weimar, the German anatomist, Welcker, com- pared both masks with the supposed skull of Schiller, and made the startling an- nouncement that there was no resem- blance between it and either mask; con- sequently it could not be the skull of Schiller. His views, of course, were not widely accepted, and caused a long and fruitless controversy between 1884 and 1887. Twenty-five years later, Prof. von Froriep found another skull in the vault, which he maintains is the genuine Schil- ler skull. He made profile drawings. of this skull and of the mask, and fitted them together. He obtained the exact: thickness of the fleshy parts of the face from a large number of measurements of suitable corpses; and his conclusions are’ now accepted as valid and beyond dis- pute. By a similar method, the genuinenéss_ and authenticity of the skulls of: the artist Raphael, and of the musicians 481

Page 86

482 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE A phantom view of the skull of the prehistoric woman of Auvernier and the probable flesh covering which it had. At the right is the modeled face of the woman. Haydn and Bach, have been successfully and completely settled. When no portrait or death-mask of a person exists, the face is reconstructed by a different method. Such was the problem presented by a well-preserved skull found in a prehistoric pile dwelling in 1878 at Auvernier, near the Neuen- berg Lake. From its appearance, it was evidently that of a woman about thirty years old, who had lived in the bronze or stone age, 7000 or 8000 years ago. In order to reconstruct a likeness of this prehistoric relic of the white race, it was necessary to ascertain the normal thick- ness of the flesh in various parts of the face. This was determined by a series of very careful measurements of the faces of eight female corpses. A very fine needle, with graduations of 1/1ooth of an inch, was used in these measure- ments. After many tiny plaster pyramids were erected all over the skull to cor- respond with the data, they were con- nected with a layer of clay, the surface of which was flush with their tops. The result was a rough clay reconstruction of the face, which was completed by an artist named Buechly, whose skill and imagination supplied the hair and neck to complete the famous lifelike bust of the Woman of Auvernier. A Mobile Motion Picture Studio A complete travelling power plant, in- stalled on a high-powered motor car, and able to furnish light for outdoor motion picture photography, is the latest addition to the equipment of the Lubin Company. This mobile power plant is equipped with a powerful generator, connected with a switchboard to which many different circuits may be run for © the successful illumination of an outdoor scene. A thirteen-inch navy searchlight, with a capacity of 4,500,000 candlepow- er, mounted upon the car, makes one think of the pictures of the great search- light cars with the armies in Europe. The entire plant and automobile weighs approximately eight thousand pounds. Compactness and simplicity of the plant was the principal aim in designing the unit. It is said that remarkably success- ful night effects have been produced with the aid of the machine.

Page 87

Photo. Copyrighted, Underwood & Underwood. A typical scene in Galveston durin the flood following in the wake of the hurricane, impression of the conditions in the business section of the city. This conveys an The Latest Galveston Hurricane T should be said at the outset that Galveston enjoyed no monopoly of the tropical storm that raged at that place August 16-17, 1915, and there is no more justification for calling it the “Galves- ton hurricane” than for calling it the “Haitian hurricane,” since this identical atmospheric disturbance did immense damage in the island of Haiti. In nam- ing a storm of this character we are con- fronted with the same difficulty that the historian will have to solve when he un- dertakes to name the battles of the pres- ent European war, some of which have involved fighting along a front of hun- dreds of miles. Like, the ever-memorable “Galveston Photo, Copyrighted, Underwood & Underwooi ° A'few of the many homes that were wrecked by the hurricane at Galveston. hurricane” of September, 1900, the re- cent storm spent some days in traveling across the Caribbean Sea and the Gulf of Mexico before it reached our south- ern coasts. It was a true West Indian hurricane. Storms of this type are ex- tremely violent whirls in the atmosphere, in which the surface winds blow in a direction contrary to that of the hands of a clock; not in a circle, but spirally inward toward the center. The storm as a whole, which covers an area never more than a few hundred miles in diam- eter, travels rather slowly along a path which, in the typical case, runs at first a little north of west, and at about lati- tude 30 degrees recurves toward the The preliminary estimate o/ the loss of property, made by the Government, placed it at $15,000,000. 483

Page 88

484 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Photo. Copyrighted, Underwood & Underwood. The wreck of a vessel that was blown inland by the violence of the wind. In the background may be seen a portion of the great seawall which has done much to prevent the recent hurricane from causing greater loss of life and property. north and northeast. In the great ma- jority of cases the recurving occurs so far to the east that the storm does not enter the Gulf of Mexico, but sweeps northeastward off the Atlantic coast. The storm of August, 1915, however, like the one of 1900, traveled across the Gulf, and the low-lying coast districts of the Gulf states were devastated by the storm waves, more damage being done by water than by wind. During the hurricane season the United States Weather Bureau receives daily cable reports from a number of meteorological stations in the West In- dies, and also wireless weather reports from steamers plying West Indian waters. The recent hurricane was first sighted August 10, when reports from Barbados and Dominica showed a fall in the barometer of .14 inch in 24 hours; an occurrence that, in tropical latitudes, means trouble. The storm center was then probably somewhere between Mar- tinique and St. Vincent, in both of which islands wind and water wrought some mischief, especially to shipping. On the morning of the 11th the dis- turbance was apparently central to the southward of St. Croix, and moving a little north of west. No damage was reported in the Danish islands, but heavy northeast gales were raging over Porto Rico. Twenty-four hours later the center of the storm lay just south of Haiti, and widespread destruction was reported in the southern part of that re- public, including some loss of life. Be- tween the morning of the 12th and the morning of the 13th the hurricane passed over the island of Jamaica, where damage amounting, it is said, to about $10,000,000 was done; the banana crop suffering most severely. During the next twenty-four hours the storm passed directly over the extreme west end of Cuba, where, among its other exploits, it destroyed the wireless station at Cape San Antonio. By the morning of the 15th it had passed over Yucatan Chan- nel and was apparently central a little north of Yucatan Peninsula, moving more to the north of west than pre- viously. The peril that now threatened the Gulf coast of the United States was unmis- takable, and every effort was made by the Weather Bureau to distribute warn- ings wherever they were needed. In fol- lowing the progress of the storm across the Gulf the Bureau relied to a great ex- tent upon the reports received by radio- telegraphy from shipmasters, and this comparatively novel method of keeping track of hurricanes again proved its great utility. On the morning of the 16th the storm was supposed to be cen- tral about 3% degrees south of the Louisiana coast, and during the night of the 16th-17th it reached the coast of Texas, a short distance south of Gal- veston. Here the barometer fell to 28.53 inches, and the wind reached a maximum velocity of 90 miles an hour. (In 1900 the barometer fell to 28.48 inches, which was lower by .10 inch than any reading

Page 89

3 3 a 0 h - POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 485 Photo. Copyrighted, Underwood & Underwood. A group of huts on the beach which have been wrecked by the high winds. previously recorded in the United States, and the wind is supposed to have been blowing at 100 miles an -hour (when the: Weather Bureau anemometer was car- ried away.) Galveston and its vicinity had ample notice of the storm’s approach, and pre- cautions were taken accordingly. Mr. W. P. Stewart, in charge of the Weather Bureau station, sent men on motorcycles over the whole of the island, thirty miles in length, on which the city is situated, warning peo- ple that they would certain- ly be drowned unless they came into town immedi- ately. Hun- dreds of lives were saved, due to this commendable precaution. The city itself was spared a repeti- tion of the tremendous disaster of 1900, in which some 6,000 persons perished, chiefly because of the remarkable engi- neering works which have been carried out for its protection by an enterprising municipality. The storms of 1900 and 1915 probably did not differ much in force or character. In each case huge Waves were generated; partly by the dif- ference of barometric pressure between the center and the periphery of the storm and partly by the force of the wind. The Photo. Copyrighted, International News Service. Piles of wreckage strewing the beach at Galveston after the passage of the earthquake. “storm wave” is a characteristic feature of a tropical cyclone, and such waves, -when they inundate-low-lying coasts, are often responsible for appalling disas- ters. Not to mention those that have de- vastated the coast of India, costing, on occasions, hundreds of thousands of lives, the Texas coast has frequently suf- fered from such waves. After the catastrophe of 1900 the city of Galveston erected a sea- wall of steel- reinforc- ed concrete, 17 feet high, 16 feet wide at the base, and 5 feet wide at the summit, along the whole front of the city. It has a concave face which is pro- tected by a rip- rap of huge granite blocks. This wall has now passed through its first sévere test successfully, on the whole, though abéut a thousand feet of it was battered down, and the people of Galveston may henceforth feel themselves tolerably secure from the fury of the waves. Another engineering enterprise car- ried out in consequence of the 1900 dis- aster was the building of a two-mile re- inforced concrete causeway connecting Galveston Island. with the mainland. Part of this was carried away in the recent storm. The mest striking, how-

Page 90

a re oe ” 486 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ever, of the precautionary measures adopted by the people of Galveston was the raising of the grade of their city to a maximum of 19 feet above its previous level. The whole city—houses, car lines, walks, etc.—was raised on stilts, while 20,000,000 cubic feet of sand, dredged from the Gulf, was pumped in, after which the whole was consolidated and restored to its normal condition at the new level. This achievement was almost without precedent. These three engineering feats, to- gether with timely warnings of the ap- proaching storm, explain why only about 14 lives were lost at Galves- ton. Consider- ably more than 100 persons are supposed to have perish- ed at other places. At Texas City, on the short of Galveston Bay, a camp of 7,000 soldiers of the United States Army was wiped out by the storm. 90° 80° Ten_ soldiers was central to the southwest of Houston, where at 2.30 A. M. the barometer (re- duced to sea-level) read 28.21 inches— a reading probably without precedent in this country—and the wind blew 89 miles an hour. During the 17th, however, the storm diminished in force and continued to recurve, so that by the morning of the 19th it was central over extreme north- eastern Texas, and was accompanied by torrential rains. General floods occurred on the rivers of the southwest. On the morning of the 20th the center was over southeastern Missouri, and heavy rains and gales still prevailed. In- cidentally, St. Louis experi- enced a rain- fall of 7 inches during the 24 hours ending 8 P. M. of the 2oth, flooding the lower parts of the city and interfer- ing with steam and _ electric traffic. On the same day the Mississip- pi rose rapidly lost their lives A map-of the region visited by the Galveston hurricane, and flood and many more were injured. Galveston was not, however, saved from severe material damage; most buildings along the water front were wrecked, great havoc was wrought ‘among the shipping, and several fires oc- curred after the storm had broken the water mains leading to the city’s sup- ply wells on the mainland. A prelimi- nary estimate places the property loss in Galveston at $15,000,000, as compared with $20,000,000 to $30,000,000 in the storm of 1900. It is impossible, at this writing, to estimate the total loss in the area visited by the storm. About 25 per cent. of the central Texas cotton crop is said to have been destroyed, and there was great damage in the oil fields. On the morning of the 17th the storm showing its position on various dates. warnings were issued, Three days after Galveston was swept, the disturbance moved eastward, south of the Great Lakes, and ceased to be a “storm,” in the ordinary sense of the term, as the furious winds that leveled buildings and plantations in the West Indies and heaped mountains of water against the sea-wall at Galveston gave place to moderate breezes. The meteor- ologist will tell you that it was just as much a “cyclone” as ever, but it ceased some days before to be a “hurricane.” To avoid the use of unclean towels at public washstands, there has recently been invented a device by which a per- son’s hands are dried by heated air.

Page 91

The “Sea Call,” claimed to be the largest and finest schooner yacht afloat at the time she was launched, was in the water barely six weeks when the corrosion of the skeleton and plates, due to electrolytic action, made the vessel practically worthless. As a result the ship has been ordered broken up for junk. The destructive agent, electrolytic action, resulted from the use of monel metal and steel together. 2 How Electrolytic Action Destroyed a Yaght HE Sea Call, a few weeks ago the largest and finest schooner yacht afloat, is now being broken up for junk after being used by her owner, Alexan- der S. Cochran, for only six weeks. Heralded throughout the yachting world as the fastest cruising yacht ever built, the Sea Call is now the center of a heated controversy between scientists, ship designers and technical writers. The Sea Call was an experiment ia ship design. She was the first steel ship ever built with a bottom made entirely of monel metal, although this metal, which is composed of two-thirds nickel, one-third copper and a small percentage of other metals, has been extensively used about ships for deck fittings, an- chors and other parts. Mr. Cochran’s yacht had been‘in the water less than six weeks when it was 487 discovered that portions of the steel skeleton and plates around the-stem and stern had been so seriously corroded by electrolytic action that it was feared the ship would go entirely to pieces within another month. As a result of this, the magnificent ship was ordered broken up for junk. Monel metal, when placed in conjunc- tion with steel in salt water, starts an electrolytic action much like that exist- ing in an electric battery. One of. the metals becomes a positive element, while the other assumes a negative polarity; the salt water forming the electrolyte or exciting solution. In this action the steel is slowly corroded and in a short time loses its tensile strength. Electrolytic action has been noticed be- fore under somewhat similar circum- stances, but has never caused the wide-

Page 92

488 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE spread interest that has been occasioned by the faulty hull of the Sea Call. The Pennsylvania Railroad, in experiment- ing with monel metal, placed a propeller upon their towboat Overbrook, which was composed of two steel blades and two monel metal blades mounted upon an iron hub. After three years’ service it was found that the monel metal had been unaffected but that the steel had been somewhat corroded. The United States Navy has used monel metal somewhat extensively, but when it was placed in conjunction with steel under water a piece of zinc was incorporated in the construction. The electrolytic action attacks the softer metal, zinc, and tends to neutralize ac- tion on the steel. The naval authorities are greatly interested in the Sea Call. A Sign that Renders Your Car Proof Against Theft An automobile tag, claimed to be the most efficient device yet put on the market for the purpose of preventing the No better protection against theft could be had than this simple plate which is placed over the usual li- cense tag. theft of cars, has recently been offered to the public by a Philadelphia concern. It is a metal plate that can be locked over the license tag and bears the startling inscription, “If this car is driven with this plate on, it is a stolen car.” The plate is simply a device for cover- ing the license number of the car with a bright colored plate bearing words which’ are sure to attract attention. The intend- ing thief cannot remove the tag without breaking the lock or using a skeleton key. This device has met with great favor among the insurance companies which issue burglar and theft insurance policies for automobiles. One company has - ordered 100,000 plates and is making them a feature of its policy. Mudguard Lights to Show the Width of an Automobile A new system for illuminating auto- mobiles has recently been patented by Edmund D. Shaw, of Syracuse, N. Y. At the present time, most cars are lighted by searchlights between the mudguards or by side lights near the driver’s seat. Mr. Shaw believes that many of the acci- dents occurring while cars are passing on a dark road are caused by an improper arrangement of the lighting system, the drivers not being able to judge the length and width of the oncoming car properly. To obviate this trouble, the inventor has placed a small light on the front of each mudguard. Holes are made in the front and sides so that when the dazzling searchlights are turned out, an approach- ing driver can see the exact width of the car. As he is passing, the light on the Electric lights placed in the mudguards of an automobile are found of great value in avoiding collisions at night on dark roads. side of the nearer mudguard shows him just how near he is to the other car at all times, and the two cars are able to pass on a narrow road without accident. = ae RO ESHER haf Nobo

Page 93

Torpedoes are launched from the decks of to do boats and cruisers by means of adjustable, gun-like tubes known as launching tubes. The torpedo is placed in the breech of the tube and the gate closed. A puff of © compressed air admitted into the chamber jin back of the torpedo ejects it into the water. Providing a Torpedo with Ears By Edward F. Chandler "THE author of this article is a recognized authority on torpedo construction. He _assisted Capt. Leon in working out the sound-control torpedo, described in this article, and he has had much practical experience in the construction of the White- head torpedoes used in the United States Navy. As the inventor of a new gyro- scopically-controlled torpedo his work has attracted the attention of the United States Government and foreign governments. considered an authoritative exposition of a very ingenious type of weapon. S a piece of mechanism the torpedo is probably the deadliest and cer- tainly the costliest weapon of modern wartare. In its cruelest modern Eure- pean form it carries about 400 pounds of gun cotton in its “war head,” and it costs about $7,000. If it once hits a ship, either total paralysis or complete de- struction is sure to follow. But what makes it hit its mark? Re- member that this deadly contrivance must travel through the water for a dis- _ tance of at least half a mile if discharged from a submarine boat, and a distance The following article may therefore be —EDITOoR. of from five to seven miles if launched from a battleship during an engagement. What keeps this $7,000 worth of death on its course? To answer that question we must first find out something about the construc- tion of a torpedo. Imagine a cylinder twenty-one feet long (the size of the latest United States model), in the nose of which a charge of guncotton is con- tained; imagine behind the charge a compartment containing air at a pres- sure of a ton to the square inch; imag- ine in back of this air tank a compressed 489

Page 94

490 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE air turbine and propellers—imagine all this and you have before you the vitals of a torpedo—all but its brain. the diaphragm would overcome the spring; the rudders would be thrown down and the torpedo would rise until Bringing a Torpedo Automatically Back on Its Course HIS conventional diagram represents several positions of a torpedo as it would appear at different points along its course. In each of the views G represents the gyroscope, the gyroscopic axis being indicated by the long arrow, which points in the general direction of the torpedo’s travel. In view 1 the torpedo is parallel with its gyroscopic axis and traveling in a straight line. In 2 the torpedo is turning to the left; consequently the rudder R has been swung slightly to the right, due to the fact that the center line of the torpedo is not coincident with the gyroscopic axis, as shown. The rudder having been turned to the right, the torpedo is steered back across its course, and in position 3 it has passed the meridian on the other side; consequently the rudder is corrected to the left, which again carries the torpedo back across the meridian, as shown in position 4. At position 5 the torpedo is virtually back on its gyroscopic line. In this country it has been the practice to employ a steering mechanism in which the rudder is swung definitely in a hard-over position either to the right or to the left with no, neutral or center stop. This causes the torpedo to steer a crooked course. Since the, rudder is provided with very little throw, the weapon deviates but slightly from its im- pressed direction. The Mechanical Brain of the Torpedo A mechanical brain of some kind is obviously necessary; for this death- dealing torpedo of ours must be guided automatically upon its course and must never swerve very far from it. Some way must be found to keep it at a set depth and to prevent it from swerving to the right or to the left. The ocean itself, paradoxically enough, holds the weapon at a fixed depth. Every one knows that the pressure of water increases as you near the bottom. If it were not so divers could perform even more difficult feats than now lie within their powers. The water is al- lowed to press against a diaphragm on one side; against the diaphragm on the other side a spring pushes. It is obvious that by adjusting the tension of the spring a perfect balance can be maintained between the sea water on one side of the diaphragm and the spring on the other. Connect the diaphragm with horizontal rudders and you have an automatic depth regulating gear. If the torpedo should dive below the set distance, the pressure of the water on spring tension and water pressure were absolutely counterbalanced. The oppo- site effect occurs when the torpedo is traveling too high and the spring tension is greater than that of the water pres- sure, The Wonderful Gyroscope—A Never- Failing Compass To prevent the torpedo from swerv- ing to the right or to the left the gyro- scope is employed—the most puzzling, the most mysterious device in the whole realm of mechanics. A gyroscope, gen- erally speaking, is any rapidly rotating body. A spinning top is a gyroscope. So is a rapidly turning flywheel. It is one of the properties of a swiftly turn- ing wheel that it resists any attempt to throw it out of its plane of rotation. It is this property of a gyroscope which is applied in automatically keeping the torpedo on its course. Now the gyroscope of ‘a torpedo con- sists simply of a small, heavy flywheel, mounted so that it may freely revolve in a frame which is in turn pivoted in what is known as a gimbal ring. In other words, the wheel can swing around s « rset

Page 95

eee t both horizontally and vertically. Before the torpedo is launched the frame carry- ‘ing the flywheel is locked, so that the wheel itself is held in a fore and aft position in the torpedo. While it is thus locked the wheel is spun at high speed. When released it will hold its plane of rotation even though the torpedo may be swung around horizontally, so long as the spinning continues. rudder with the gyroscope, the torpedo by the very act of departing to the right or to the left, will swing them and thus pring itself back again to the predeter- mined course. If the torpedo curves to the right, the rud- der moves to the left; if the torpedo _ starts off to the left, the rudder shifts over to the right. The torpedo always travels along the line passing through the plane of the gyroscope’s ro- tation, and the plane or rota- tion always lies along the line which the torpe- do is supposed to take — the line in which the torpedo is pointing at the instant the spin- ning wheel is set free. It is wonderful, in- deed to think that a little spin- ning wheel keeps a torpedo on its course. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 491 How a Torpedo Is Launched By connecting How the Gyroscope of a Torpedo Works I N the drawing, 1 is a fly wheel, and 2 the frame carrying the fly wheel, half of which has been removed to expose the wheel. This frame is pivoted in a horizontal plane in the ring 8, which has also been broken away, as shown. Ring 8, which carries the fly wheel in the frame 2, is pivoted at 4 and 5 in the vertical plane in a suit- able support or frame. It is evident that the gyroscope fly wheel 1 is not only free to revolve about its axis, but also to swing around its verti- cal and horizontal pivots. For the convenience of illustration 6 represents an insulated member carried by the ring 8, and having @ contact surface 7. Resting against the contact surface is a brush 8, which is connected in circuit 9 with an electro-magnet 10 and a bat- tery 11. In the picture the current is on and the magnet energized; in consequence the armature 12 is drawn over. The armature carries a balanced valve 18, which controls the flow of compressed air through the pipe 14 to the turbo-motor 15. The piston rod 16, of the turbo-motor, also acts as the rudder rod for the horizontal-course steer- ing-rudder 17, on the post of which is a crank 18. When the gyroscope swings around so that the insulated portion 6 is carried under the brush 8, contact is broken and the electro-magnet 10 de- energized. The spring 19 then instantly pulls the armature 12 and consequently the valve 18 to the opposite extreme position, thus causing the rudder 17 to shift over. The arrow A represents the general direction in which the torpedo is supposed to be traveling, it being understood that the gyro- scopic fly wheel 1 is revolving at high speed. A torpedo is discharged from what is known as a launching tube by a puff of compressed air. At the top of the tor- pedo is a little latch, which is tripped as the torpedo passes out of the launching tube, so as to cause the compressed air to operate a little engine which spins the torpedo. The air is auto- matically cut off and the gyro- scope __ released when a sufficient speed of rota- tion has _ been attained. Com- pressed air is also supplied to the _ propelling engine of the torpedo at the same time. All this must happen during the frac- tion of the sec- ond required for launching. It is evident that a torpedo is nothing but a little ship, trav- eling through the water at railway speed, guided by a me- chanical helms- man, and kept on its course by an automatic compass — its Syroscope. Surely it would be difficult to imagine any- thing more me- chanically intel- ligent. Unlike most human be- ings, a torpedo is absolutely obedient ; it does exactly what it is told. Perfect as this

Page 96

492 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE mechanism seems to be, nevertheless, it has its defects. it must adhere most surely to its course— It is not quite modern ina word, at the moment of striking. enough. Launch it from a submarine at a Other factors must battleship a half a mile or a mile distant, and it will perform its task with ghastly per- fection. But launch it at a dread- naught seven miles away — and this is the range at which mod- ern sea bat- tles are fought— and it is doubtful if it will ever find its mark. Why? Firstly, be- cause it is hard to hit a moving target at long range, if not actu- ally impos- sible; sec- ondly, the gyroscope gradu- ally “dies” down like a boy’s top which has spun too long. Once the speed of the spinning flywheel drops below acertain critical point the torpedo no longer keeps upon its course. Unfortunately this slowing up of The Ears of the Leon Electrical Torpedo and How They Hear a Hostile Ship HIS is a schematic diagram of the apparatus invented by Captain Leon to control torpedoes by enabling them literally to hear the propellers of a hostile ship. The “ears” or sound responsive devices 20 and 20' (microphones) are enclosed in a suitable casing located within the head of the torpedo and surrounded by a sound-transmitting medium, such as water or gelatine. The sound passes directly through the shell of the metal head, which is about one-sixteenth of an inch thick. The two microphones are connected by an electrical con- ductor 21 with an adjustable device 22. The rudder 23 is here shown directly controlled by the magnets 24 and 24, which are electrically connected with the adjustable con- trolling device 22 to receive energy from a battery 25 when the switch 26 is automatically thrown into operation. This switch 26 forms part of a clock work mechanism which throws out the gyroscope control and connects the sound control, after the torpedo has traveled within the range of the sound vibrations sent out by the propellers of the enemy. It is important that the torpedo should not turn upon its own ship in response to the beating propellers. Hence the torpedo is made to travel under gyroscopic control for a certain distance, before the “ears” are allowed to operate. : To illustrate the operation of this apparatus, let E repre- sent the position of the enemy when the torpedo is origi- nally discharged and F the intended line of fire. Had the torpedo continued as originally intended it would have missed its mark, the enemy having proceeded in the mean- time to the position I’. As soon as the sound device is released for operation by the clock switch 26, vibrations are conveyed to the torpedo along the lines X and Y. Rays traveling along the line X strike the microphone 20 squarely, whereas microphone 20' is out of the zone of influence. Clearly, the microphones are out of balance; one “ear” is hearing more than the other. The magnet 24 is therefore energized, and the rudder 23 is automatically turned in the position shown, thus causing the torpedo to be steered around toward the enemy. When the torpedo is headed for the enemy and consequently both microphones are equally energized, the rudder assumes a midship position. also be con- sidered. The speed and _ direc- tion of the vessel which fires the torpedo must be considered, so must the distance to be covered, the time allotted to reach the target, and the target’s speed and direction. Fire point blank at a battle- ship only three miles away and the torpedo will miss its mark; for by the time the 35-knot weapon covers the intervening distance the ship will be many yards beyond the point at which the torpedo was intended to intiict its destruc- tion. Clear- ly, the tor- pedo must be shot ahead of its mark, and it must be so timed that the two will inevitably the gyroscope occurs just when the torpe- meet. It is so difficult to make all these calculations that long-range torpedo fir- do should be most trustworthy ; just when

Page 97

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 493 How the Leon Torpedo Hears an Enemy’s Propellers and Directs Its Course Accordingly. : straight dotted line represents the intended course of the torpedo as it was dis- patched originally against the enemy. The enemy has passed beyond the path of the torpedo; but, thanks to its microphones or ears, the torpedo alters its course as shown by the dotted line and overtakes the enemy in its new position on a curved path. ing is much less dangerous than is com- monly supposed. Because battle ranges are now so great that the gyroscope cannot be expected to keep up its spin for a corresponding period, we find Nikola Tesla, Rear Ad- miral Bradley A. Fiske and John Hays Hammond, Jr., trying to control tor- pedoes by wireless. But a much more startling plan than theirs is that of Cap- tain Karl O. Leon of the Swedish Navy. He would have an enemy’s ship destroy itself by attracting a torpedo to its very side. His invention consists in giving a tor- pedo ears—electrical ears which will en- able it to hear the propellers of a ship and direct itself toward the sound. Only a ship at anchor would be safe; for in the murkiest weather or the darkest night his torpedo will hear the propeller vibrations and head for them. The Electrical “‘Ears’”” and How They Hear Captain Leon’s electrical ears are microphones. A microphone is found in every telephone transmitter. It is an instrument for intensifying feeble sounds, or for transmitting sounds, and it is based on the principle that the transition between loosely joined electric conductors decreases in propor- tion as they are pressed together. The conductors form part of a circuit through which a current is passing, and the variations in pressure due to sound waves in the vicinity of the conductors produce variations of resistance, and hence fluctuations of the current, so that the sounds are reproduced in a tele- phone receiver. In the modern telephone the transmitter is essentially a micro- phone, the pressure of the sound waves being communicated to the conductors by means of a diaphragm. Captain Leon mounts four of these sensitive electrical ears on a torpedo. When they are influenced by the sounds of the enemy’s screws they automati- cally steer the torpedo, not at the direct source of sound (the propellers), but several yards to the right or left, ac- cording to the direction in which the hostile ship is traveling. The four sen- sitive ears are in the head of the torpedo and point forward. Two of them are located on the horizontal center line and two on the vertical. The right and left microphones on the horizontal center line control the horizontal steering rud-

Page 98

494 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ASK AIR FLASK PLY(HIGH PRESSURE ABER diagrammatically shown on page 491. The Shonnard Torpedo— ‘om drawing shows schematically the application of the Leon steering device to a modern long-range high-speed alcohol propelled submarine torpedo invented by H. W. Shonnard. In the fore part of the torpedo head can be seen the starboard microphone receiver. In the upper part of the head is located a box in which the adjusting mechanism is contained, the purpose of which is so to regulate the microphone as to cause the weapon to strike either to the right or to the left of the source of sound. An electric cable extends from this controlling box through the air flask to the gyroscopic gear located in the after body. The gyroscopic gear is connected with the rudders as described in the article and The Shonnard torpedo is perhaps the most promising type of internal combustion pro- pelled torpedo which has yet appeared upon the horizon of American practice, and it is here illustrated in conjunction with the Leon microphone steering device because of its extreme novelty of design. It will be noted that the propellers are driven by three hori- zontal engines, one of the cylinders being located above and two below the center line of the torpedo, thus ensuring stability and providing a very compact and powerful motor. Around the engine is an enclosed space in which the liquid fuel (alcohol) is carried. ders, and the upper and lower micro- phones on the vertical line control the depth steering mechanism. Preventing the Torpedo from Blowing Up Its Own Ship Captain Leon also employs a gyro- scope, but it serves to guide the torpedo only for a short distance. As soon as the electrical ears hear the propellers the gyroscope is thrown out of action automatically and the ears left to them- selves. Of course, the vessel which fires the torpedo also has propellers. It is very important that the torpedo shall not hear them, turn back on its course and blow up its own ship. For that rea- son a suitable clockwork time switch is introduced which keeps the sound ap- paratus from operating until the torpedo has proceeded a considerable distance on its deadly errand. If the Leon torpedo is correctly point- ed toward the enemy, an equal amount of sound reaches each one of the micro- phones or ears; but if, for instance, the weapon is traveling too far to the right or to the left the effect on one ear is greater than it is on the other. Conse- quently, the rudder is caused to shift and the torpedo’s course is altered until the microphones are all equally influenced by the vibrations set up in the water. After that the torpedo proceeds head on. Sound travels much more quickly and clearly in water than it does in air. That is one reason why the propellers of a large battleship will set up a disturbance UNAS

Page 99

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE to the engine ‘at a uniform pressure. into: the cylinder. The Latest Fashion in Torpedoes Compressed air from the air flask passes through a reducing valve and is delivered The liquid fuel is maintained under pressure derived from the air flask and is delivered to the mixing chamber. The propeller shafts are tubular and are telescoped one within the other. revolved in opposite directions by a group of three gears directly driven by the engines. An extension on the end of the main propeller shaft revolves within a casing and performs the function of a rotary valve, the head of which forms one-half of the mixing chamber. The ignition system has, of course, the usual spark plug and magneto. E From an oil flask oil is delivered under pressure to the valve chamber, where it serves the double purpose of lubricating and preventing leaks. When the starting latch on top of the torpedo is tripped, which happens when the torpedo is launched, compressed air is admitted to the engine in order to start it. proper instant a suitable charge of alcohol is sprayed into the mixing valve and exploded Shonnard employs a tank of compressed air so as to relieve the engine of the necessity of compressing the charge in the manner familiar to every automobilist. They are At the in the water which would influence deli- cate microphonic receivers over a very great distance. Even though the torpedo may be several thousand yards out of its course, it must inevitably be drawn to- ward its prey. The Ultra-Range Gyroscope and Its Possibilities Originally Capt. Leon did not include a gyroscopic steering gear, but depended solely upon the sound-receiving micro- phones for steering. This arrangement is unsatisfactory except for very short distances, because the weapon is liable to make a large detour before the sound apparatus comes into play. The introduc- tion of the gyroscope was a decided im- provement and greatly increased the efh- ciency of the weapon. By using the ultra-range gyroscope in- vented by the author it is possible to in- crease the efficiency of the Leon torpedo almost 100 per cent. The extreme accu- racy which is made possible by this new form of gyroscope greatly reduces the demands made upon the sound receiving apparatus. In actual practice it is neces- sary to employ only two sound receivers, one on the right side and one on the left, in order to maintain a_ horizontally steered course. Guiding the Torpedo by Means of an Echo The Leon torpedo, it has been pointed out, is effective only against a moving ship. Why not send out a call from the torpedo and let the ear be guided by the

Page 100

496 POPULAR SCLENCE MONTHLY AND WORLD’S ADVANCE echo? In order to make.thetor- f= pedo effective even against: an anchored vessed, the authgr, has’ conducted experiments wich lead him to believe that arragscil- lator or sound producer be. inserted in the nose. of ‘the #pr= - pedo for the purpése of: sefiding out sound vibrations whict may be reflected by, an anchoré@ghi There is good -reason :to.R88 that the effect of, the tem sound is practically the’ as” that of the direct vibrationss" ex- cept that over great. distances | they are somewhat enfeébled. But the results thus far obtained are encouraging to such aft-ex- tent that it will ultimately..be possible to use the Leon torpedo even when a ship’s propellers are not working. Capt. Leon is not the only in- ventor who has been working in this field. Christian Berger of Hungary and John Gardner of England have in- dependently suggested the, use of micro- phones onatorpedo. It was-their idea to place one or more microphones on a tor- pedo. But instead of picking up sounds emanating from a hostile vessel, they in- tended to send out submarine signals from a controlling station, by means of The torpedo tube of an American submarine boat. The pivoted lid is opened at the moment the torpedo is to be ejected. - which the course of the torpedo could be governed. To this there is the manifest objection that the vessel must be seen to be guided. Although it is not necessary to provide the torpedo with high masts easily shot away (one of the difficulties of wireless control), it is nevertheless necessary to watch the course of the tor- pedo while it speeds toward the enemy. THE LIGHTNING ROD COMES BACK © After a number of years of increasing uripopularity, the lighnting rod is rapidly reappearing on the roofs’ of houses and barns throughout the country. The state- ment made a great many years ago by those who were supposed to know, that lightning rods not only were ineffective as lightning preventives, but that they actually attracted lightning, has been proved to be absolutely false by an ex- tensive series of tests made by the United States Weather Bureau: Circular let- ters were mailed to mutual insurance companies throughout the country, es- pecially to those in the agricultural dis- tricts, requesting statistics concerning the fire ‘losses of insured buildings occa- sioned by lightning in comparison with losses due to other causes, and particu- larly the fire losses occuring to buildings equipped and unequipped with lightning rods. The replies gave strong evidence of the value ofthe rods. In 1912 and 1913 about 200.mutual insurance com- panies doing a business of fully $300,- 000,000 had 1,845 buildings struck by lightning. Of this number only 67 were equipped with lightning rods. So far as could be learned about 31 per cent of the buildings insured by these companies were rodded; hence, if the rods had furnished no protection, buildings struck would have numberd 572 instead of 67. Thus the efficiency of the rods in actually preventing lightning strokes appears to have fully go per cent.

Page 101

MONG the species of Argentine woods on display in the Agricultural Pal- ace, is that known as Quebracho Colorado, which is worthy of men- tion because of its unusual qualities, which fit it espe- wash them into the sluice troughs, where the gold is caught. Then there is the bump- ing table or con- centrator, which separates the free placer gold from the lighter sand and gravel by a shaking-up pro- cially for types of construction requiring a wood that shall withstand the attacks of the elements for a maximum of time. This Que- bracho wood, resembling red-wood in color, has a density of 1.225 and weighs from 70 to 80 pounds to the cubic foot, or approximately 20 pounds more per cubic foot than live oak. It is used by all Argentine railways for ties, and is practically indestruc- tible, even when in contact with the ground; in fact, ties which have been in use for twenty-five years are still sound and will outlast the steel rails. The wood’s durability is shown by pieces of con- struction timber taken from a dock in Buenos Aires. The wood, though ex- posed to the water and elements for fifty years, is apparently as sound as it was when first driven into place. An instructive exhibit in the California state building is that comprising work- ing models of such apparatus as is used in the various methods of the metal- lurgy of gold. There is a large topo- graphic model of a mountainous section typical of the type of country in which the hydraulic process might be employed. The delivery pipe, running down the side of the mountain, supplies water to the huge monitors, which direct powerful streams against the dirt and rock and 497 cess; placer gold being a term applied to deposits found in beds of sand, clay or gravel formed by the corrosive action of the weather upon original deposits. The latter, in the form of veins running through the rock stratum, is termed reef gold, and is often separated by the amal- gamation process. The gold-bearing ore is put into the stamp mill, where it is crushed and then washed over amalga- mated plates (copper plates coated with mercury), where the gold is amalga- mated or held back by the mercury while the quartz and other rock materials pass on in the form of tailings. The pure gold is then separated from the gold amalgam by a process of distillation. The silver, with which native gold is usually alloyed, is often recovered by this same method. Nearby is a remarkable work- ing model of a huge Yuba gold dredge. It is about ten feet long and is operated by a number of electric motors, the cur- rent for which is controlled from a switchboard located outside of the tank in which the “dredging” operations take place. Yonder series of eight substantial safes houses the $100,000 collection of gold nuggets and gold-bearing ore, as well as a few hundred dollars’ worth of diamonds and platinum nuggets, which tend to add to the attractiveness of the

Page 102

498 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE whole. This is said to be the finest col- lection of gold in its various forms ever assembled. The United States Army and Navy exhibits in the Palace of Machinery are probably the most popular—as_ they naturally would be under existing condi- tions—of all the displays in the main exhibit palaces. Demonstrations are given several times daily of the method of protecting harbors and inlets by means of electrically controlled mines. There is a glass tank about 20 feet long by 4 feet wide and 5 feet deep which is partly filled with water, in which floats a model of a battleship, so arranged that it may be drawn back and forth parallel to the sides of the tank by an electric motor. A number of miniature mines are an- chored, by weights resting on the bottom of the tank, a few inches below the sur- face of the water. These mines contain several little glass windows through which the observer may view an electric lamp which represents the explosive charge. At each end of the tank is a working model of a coast defense forti- fication with its equipment of mortars, disappearing guns and searchlights. An explosive charge, placed in the bow of the battleship, is so connected that it may be fired by passing a current through the wires controlling the motion of the vessel. The lamps within the various mines are connected electrically with a keyboard at one of the shore fortifications, and the firing of the mine is represented by the lighting of the lamp in its interior and the explosion of the charge within the ship. The object of the demonstration is to show that any one of the mines can be fired at will; thus making them a source of danger to a foe, but harmless to an ally. A par- ticular mine is designated and the unin- itiated spectators are told to note its action when the ship passes over it as an ally. Nothing happens. The ship is next treated as a foe. The searchlights and guns of the shore fortifications im- mediately get into action and the ship proceeds toward the mine. Upon reach- ing it the lamp within lights, an explosion takes place which tears a hole in her side and blows off her stacks, and she lists to port and begins to sink. Then, when the delighted spectators have dis- persed, the attendant repairs the ship and makes it ready for the next demonstra- tion. The type of electrically controlled mines used in “observation” firing, un- der actual conditions, consists of a water- tight steel shell three feet in diameter and from three to seven feet in length, partly filled with explosive and contain- ing the detonator. The mines are held in place about ten feet below the sur- face by cast-iron anchors weighing 2,000 pounds each. These anchors are auto- matic in that they automatically pay out enough cable to permit the mine to float at the required depth; thus in the plant- ing of such an anchor it is necessary to know only the approximate depth of the water. The automatic feature consists, essentially, of a heavy weight connected with the anchor by a rope or cable of a length equal to the depth at which the mine is to float; the cable being so con- nected to the anchor that the reel within, paying out cable to the mine floating on the surface above, is automatically stopped when the tension on the cable carrying the weight ceases by reason of it reaching the bed of the ocean. The anchor continues to sink and, the reel within being locked, the mine is pulled below the surface to a depth equal to the length of the measuring cable. The mines are planted in groups of from 7 to 19 each, there being a distance of about 100 feet between the mines of each group, and their cables are led to a distribut- ing box, resting on the bed of the ocean, which is in turn connected with the firing station at the shore fortification. The usual charge is 100 pounds of trotol, and it has been determined, by experiment, that the maximum destructive effect oc- curs when the explosion takes place at a distance of about seven or eight feet from the hull of the ship; the area af- fected at this distance being greater, and the damage of a more desirable nature, than when the explosion takes place right next to the hull. The advantages of trotol over guncotton lie in its greater destructive power and the comparative safety with which it can be handled. It cannot be detonated when the least bit

Page 103

damp and hence can be handled with im- punity by merely keeping it slightly moist. There is an interesting display of vari- ous sizes and types of projectiles, some of which are shown in longitudinal sec- tion. The largest is a 16-inch cast iron shot which stands on end about 5% feet high. It weighs 2,400 pounds and the propelling charge is 66614 pounds of smokeless powder. Near by is a large section of six-inch nickel steel armor plate which has been pierced through and through by a six-inch shot, appar- ently as easily as one might pierce a sheet POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 499 of paper with a pencil. There is always a group of people admiring the White- head Automobile Torpedo and the at- tendant thereto is kept remarkably busy answering questions pertaining to its virtues. The periscope is another popu- lar instrument and it amuses its ad- mirers by enabling them to view scenery on the farther side of an adjacent wall. There is a collection of chronometers which are of particular interest to the antiquary ; among which are several re- covered from the battleship Maine, now rusted almost beyond recognition after their fourteen years of submersion. HOW GERMAN BREAD LAWS IN- SPIRED AN INVENTOR Laws have been passed in Germany which determine not only how much bread may be sold to any one person but when he may buy his bread—all because the country’s food supply must be hus- banded during the war. Curiously enough, these laws have given one Ger- man inventor a chance to enrich his day and generation with a device that every Teutonic household needs. If there is any- consists simply of a perforated drum with a toasting plate inside. Hold the drum over an alcohol lamp for two min- utes, turn it, and the roll of yesterday, inside, becomes as fresh ard crisp as if it were baked an hour previously. THE UNFAITHFUL COMPASS AND THE POLE" “True as the needle to the pole,” like many another popular saying, must fall by the board. It is thing that a German loves with his cup of f coffee in the morn- ing it is a crisp, hot roll. Alas, the law forbids the selling of rolls in the morn- ing. They must be bought in the after- noon. That inspired one German with an idea. He would eat no soggy rolls of yesterday’s baking. And so he invented a roll warmer which can be placed on the I 1 no longer scientific- ally true. In order that it may keep it- self duly informed as to the unfaithful- ness of the needle to the pole, or techni- cally, the “variation of the compass” from the true north, the United States Government main- tains a Division of Terrestrial Magnetism. magnetic needle Not only does the table. vary at different His invention is This convenient form of heater for the morning rolls places, but the vari- simple enough. It has been invented by a German as a result of conditions in his country. ewer ation changes from a a Sn ai ia

Page 104

500 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE year to year, and even at different times in the day. Places which, at a par- ticular time, have the same amount of va- riation, are connected on magnetic-survey charts by what is known as an “isogonic,” or equal-variation line. Through these points on the map in which there is no variation of the needle from the true north, a line known as the “agonic” passes. Iron deposits and mountain ranges modify the action of the unknown causes of periodical variation, so that the corre- sponding lines become very crooked. Tsogonic charts may be accurate to-day and full of small errors in a few years. The famous boundary between Pennsyl- vania and Maryland, known as “Mason and Dixon’s Line,” surveyed in the years 1763 to 1767, was “run by the stars,” and not by the needle. That was a great piece of foresight for its day. Had the line been surveyed by the compass in 1800, it would have shown a deviation in some places of two miles, and had it been run by uncorrected compass a hundred years later, in 1900, the variation would have reached nearly nineteen miles to the south. As a result the rich coal fields of two Maryland counties would have be- longed to Pennsylvania. And yet peo- ple ask: “What’s the good of science?” The discovery of the magnetic needle’s shortcomings was probably made during the voyage of Columbus. Certainly the great Genoese must have wondered at the behavior of the compass. Indeed, it is said that the needle’s action spread consternation among his crew. A NECESSARY POISON Arsenic is not one of the things that we are apt to think we could not get along without, but according to the French scientist Gautier, its presence in the human body is absolutely necessary to some of its most important vital proc- esses. This terrible poison, the mere mention of which calls to mind the philters of an- tiquity and the fascinatingly horrible op- erations of the poisoners of the Middie Ages, is, it appears, neither more nor less than a constituent element of the tissues of all living beings, vegetable or animal. Without arsenic, no life is pos- sible; a purveyor of death is one of the great supporters of life. Arsenic, says Professor Gautier, ex- ists normally in man and animals, in the skin and its appendages, in glands and in the brain and the bones. In the other organs it has been found only in slight traces. This organic arsenic is eliminated by the skin, the hair, and the horns in mammals. Whence comes this arsenic? Gautier, not having found it in wheat, discovered it in such lower plants as marine algae, seaweeds and “plankton,” that strange food of whales, consisting of vegetable débris, lower animal life and microscopic algae, suspended in sea-water. Sea-wa- ter, then, the great generator of the lower forms of life, is a veritable bouil- lon of arsenical cultures. Where does the sea get this quantity of arsenic, which, taking into account the enormous mass of sea-water that covers the globe, must represent a huge weight? Only the primitive rocks that. have been corroded and abraded by the sea since geologic times would seem ca- pable of furnishing this quantity of ar- senic. And, indeed, Gautier found by chemical analysis that this was so— that granite, for example, contains ar- senic. The provision of arsenic on the earth’s surface is, therefore, enormous, and will be sufficient for ages for the consumption of living beings, who also constantly restore it. The arsenical cy- cle has, it appears, thus been established by Gautier. First the sea takes it from eruptive rocks and dissolves it. Numer- ous marine plants, as well as fishes, ab- sorb it, and transmit it to man. Land plants also take it from the soil formed by the débris of old rocks and pass it on to other plants and to animals. There is now on the market an elec- tric filter for household use in which current is only consumed as the water is being drawn through it.

Page 105

Scrubbing Device A scrubbing device that automatically feeds itself with water and soap is the boon to housewives which has recently been invented. A tube connects the scrub- bing brush with a faucet through which a continual stream may run. Part way down the hose is inserted a container for soap. The water running through this container becomes suitable for scrubbing without further application of soap. At the end of the scrubber is a perforated plate over which a cloth is fastened. The soapy water runs through the perfora- tions and seeps into the cloth, making what is claimed to be a very useful and labor-saving device. Sound-Transmitting System A new form of apparatus for trans- mitting sounds over wires to a plurality of telephone receivers is the subject of a recent patent. As will be seen by the accompanying sketch, the transmitting member of the system consists of an arc enclosed in a chamber to which is se- cured a horn or mouthpiece. As the sound waves pass through the horn they affect the steadiness of the arc, thus Recent Novel Patents varying the current passing through it. These variations are transmitted through an induction coil and the line wires lead- ing to a number of telephone receivers. Automatic Fire-Alarm System A simple automatic fire alarm that is connected with the lever of an ordinary telephone instrument has recently been put on the market. The device is so adjusted as to hold the hook lever of the telephone receiver in the same position as it occupies when the receiver is hang- ing in its place. If a fire starts, the heat melts a fusible link and starts a spring mechanism which moves the receiver up and down in a regular and predetermined manner. The telephone operator in the central station, knowing this signal | to be caused by a fire, immediately sends for the fire department. This little device has thus performed its duty as satisfactor- as could a compli- cated, high-priced system.

Page 106

502 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Crib Arrangement for Bedsteads A crib which may be attached to the side of an ordinary bedstead, and which may be rocked by the mother without necessitating her getting out of bed, has © recently been awarded a patent. Two wooden arms are bolted under the bed- stead to hold the crib, which is suspended on these arms by four hinged supports. These supports permit of a lateral rock- ing of the cradle, which is said to be as soothing to a fretting baby as the old- fashioned rocking cradle. * Lathering Implement An instrument that obviates the la- borious task of first lathering the face and then rubbing in the lather with the fingers. to soften the beard has recently been granted a patent. A soft brush and a rubber bristled brush are both mounted on a light holder made of U-shaped steel wire. The face is first lathered with the soft brush, then the instrument is turned over, and the softening is done with the rubber bristles. Curtain for Shoe-Polishing Chairs A victim of the wiles of a “shoe-shine artist” will no longer be forced to sub- mit to having his trouser legs daubed to the knees with polish and grease, for a Maryland inventor has recently patented a curtain which hangs from the ex- tended arms of the chair and protects the sitter from the knees to the shoe- tops, as is shown in the accompanying illustration. Novel Mouse Trap An adaption of the familiar “see-saw” of our childhood days is the underlying idea for this novel mouse trap. A strip of wood is projecting well beyond the base of the trap, and is affixed to its sup- port by a hinge. A piece of bait is held ee Z out on a wire over the projecting plat- form. When the mouse walks out on the platform to seize the bait the plat- form becomes overbalanced and tilts suddenly, dropping the mouse into a re- ceptacle below. An Austrian inventor has recently pat- ented a design for umbrellas, shaping them like flowers. He believes this de- sign to be superior to the familiar round pattern.

Page 107

Sanitary Telephone Mouthpiece Many inventions have been patented as improvements over the unsanitary telephone mouthpiece. One of the most recent patents for making this breeding place for microbes more sanitary is shown in the ac- companying illus- tration. A roll of antiseptic paper is held in a_ dust- proof holder di- rectly over the mouthpiece. The paper is drawn through a clip which holds it tightly over the transmitter. When a person goes to the instrument he pulls down the used section of the paper and tears it off, leaving a clean and hygienic surface to talk into. Holder for Paint Brushes A rack for holding paint brushes when not in use can be made from a length of stiff wire, bent into a series of loops and nailed down at either end. Contributed by B. W. VERNE. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 503 To Preserve Useful Suggestions The writer has gained many valuable suggestions from articles in this depart- ment on the subject of chemistry in which he is particularly interested. These articles are clipped each month and pasted in a note book for future refer- ence. In the front of the book an index is written from month to month. This systematized “clipping bureau” has proved itself invaluable on more than one occasion. Contributed by S. D. WittiaMs. SAW-MILLS IN CITY STREETS The conversion of fine residence streets into temporary wood-yards and saw-mills during the fall and winter months is a spectacle that never fails to amaze the stranger who chances to be in Portland, Oregon, at those seasons of the year. Wood, which is the principal fuel used in both furnaces and fireplaces, is sup- plied and purchased in four-foot lengths and is cut to order for domestic use, sometimes by the dealer in his yard, but more often by an itinerant wood-sawyer equipped with a portable gasoline saw- mill mounted on an ancient automobile chassis. ELECTRICAL RESISTANCE AS A CRITERION OF HEALTH ong the physician in diagnosing your case, instead of taking your pulse and temperature, saying, “I think I had better take your electrical resist- ance.” Removing from his bag a piece of apparatus somewhat similar to a med- ical battery, he proceeds to adjust a pair of electrodes and place a telephone re- ceiver to his ear. After a moment or so he announces, “Your resistance is a few hundred ohms too low. Your cells need toning up.” In the future such an occurrence may be a reality instead of a flight of the imagination. In fact, with the perfec- tion of apparatus and development of a proper technique, such a thing is entirely possible. The cells, of which all living organisms are composed, possess semi-permeable membranes which have the power of ex- cluding some substances while freely ad- mitting others. If the vitality of the cells is decreased, this power of discrim- = a Ray mgs ee ws eS saad so td ra ne ge ee a = = RT

Page 108

504 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE inating between what shall b< admitted and what shall be rejected is also dimin- ished. When the cells are dead this power is entirely lacking and substances which would be excluded if the cells were alive readily pass through the plasma membrance surrounding the protoplasm of the cells. By bringing living tissue in contact with a salt solution or some other electro- lyte, arranging the electrodes so that the substance in solution must pass through. the tissue, and then measuring the re- sistance that is offered to its passage, it is possible to tell whether the cells of the tissue are in a healthy condition or not. If the cells are in a healthy or vig- orous condition they offer a high resist- ance to the passage of the ions, in other words, they are poor conductors; but if their vitality is low they offer less re- sistance, and, if dead, very little resist- ance. Very weak currents may be used, so that there is no injury to the living tissue from the effects of the electric current, this being fully determined by many experiments. The cause of the high resistance of living cells is found in the semi-perme- able membranes previously mentioned, and the resistance is proportional to the vitality of these membranes, and upon the vigor of the cells depends the health of the entire animal or plant, so that the resistance offered is a criterion of the health of the organism. Prof. Osterhout of Harvard Univer- sity has used this method in determining the effects of various substances, such as salts, alkaloids and anesthetics, upon plant cells, and has obtained more exact knowledge upon the subject of perme- ability than has hitherto been possible. Most of his experiments have been upon Laminaria saccharina, a species of kelp, but the same method with certain mod- ifications can be used upon other plants and animals as well. The apparatus is so arranged that a weak alternating current must pass through the cells of the plant, and the resistance be meas- ured on a Wheatstone bridge. Many substances that are injurious to the living cells are antagonized by other substances that are also harmful, so that a mixture of the two is comparatively harmless. This is frequently true even when no chemical combination of the two sub- stances takes place. ‘It is an odd fact that these marine plants soon die in a solution of common salt, although this is by far the largest mineral constituent of sea water. However, if a small quan- tity of a calcium salt be added, they live about as long as if they were in sea water. Either one of these substances alone is toxic, but a combination of the two in the proper proportions is harmless. They antagonize one another. Dr. Osterhout’s work has _ thrown much light on the manner in which anes- thetics produce insensibility to pain. His experiments lead to the conclusion that the anesthetic raises the resistance of the nerve cells. It is probable that sensa- tion is accompanied by electrical cur- rents that pass along the nerves to the brain, and as the anesthetic raises the resistance of the nerve cells the current becomes too feeble, and a decrease or total absence of sensation results. Biologists are now using this method upon animals and very recently on hu- man beings. From recent experiments it is probable that very important dis- coveries will soon be announced. It is certain that the method will be extensive- ly used in the future and altogether probable that it will be of service in the diagnosis of disease—LrEE Morrison.

Electricity Direct from Coal A patent has recently been granted a German inventor for an application of the familiar thermo-pile principle to the production of electric current in con- siderable quantities without the interven- tion of boiler, engine or dynamo. While the principle of the device is similar to that of the old-time thermo-piles, the present arrangement utilizes a furnace fitted with suitable couples made of heat- resisting materials, and it is said that the apparatus produces a current of such volume that it may be put to practical use. The cost of producing the current is said to be somewhat less than that of the usual method employing steam, and it is certain that the first cost of the plant is considerably less than that of a mod- ern generating equipment.

Page 109

e . a . The Home 3g wml SS - A Craftsman Craftsman TN a hy All) Desk Table Describing the Construction and Finish of an Attractive Desk Table of the Arts and Crafts Style By Ralph F. Windoes Instructor of Manual Training, Davenport High School, Davenport, Ia. RODUCTS of handicraft uncon- P sciously stamp themselves with the individuality of their maker. Snug- fitting joints; clean, sharp edges; a beautiful finish—and in the mind of the observer is seen the builder—neat, clean, and precise. Conversely, dirty work; open joints ; smeared finish—and in one’s mind flashes a picture of just such a workman. Hence, when we make the new claim for homecraft work—that it has a cultural value as well as an econo- mic one—our contention among the ob- servers will be substantiated. Never leave a piece until it is just as good as you can make it. If you know that the distance between the shoulders of an end rail is 17”, and of the corre- sponding stretcher for the same side is 167%”, don’t glue it up and close the gap with a tightly drawn clamp. You may be able to bend the leg, and by pinning the tenons, make them hold, but you would be cheating yourself. You would not be getting your full share of value from the work you were doing. All handwork demands the utmost in exactness—an inch is an imch—not 31/32”. Can you imagine a gas engine 505 running whose cylinders were bored 1/32” larger than the pistons were turned? I believe that there is a sermon in homecraft work. I once knew a sloven- ly workman who was keeping his own time on a job. He worked about eight hours a day—but his time went in for ten. “Oh that’s near enough,” was his motto. Now if that man in his work had never left a thing until it was just right, his morals would never have been so corrupted that he would steal from his employer. Make the most of your opportunities. If you are building furniture for pleas- ure, see that you do each thing just right, and you will derive untold benefits from it. With this issue we are presenting de- tailed drawings of a desk table. It is no project for the inexperienced to attempt, but an excellent one for the older home- craftsman. It demands the accuracy pleaded for above, and if given a reason- able amount of care, will resolve itself into an article of beauty and great use- fulness. TT LO RS A LS ~s - racine snee _— mores Bes ere Ne aren eet, PEE en nae ee ne a ee SS

Page 110

506 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Go to the mill with the following mill bill, and insist that each piece be cut to exact dimension and sandpapered. For stock, we would suggest nothing but quarter-sawed white oak, kiln dried, but the craftsman may prefer some other wood. 4 pes. 134" x 1347228 W.rcccece eccccccccece legs 1 pe. 4 x23 "x36 mas to ; x Be a 2000950000005 she ac i oe. 4" x ts ae back rail 2 pes. K" x SD ahs cebeeeesicas > end rails 2 pes. yn Qt De stretchers ee oe lower shelf 1 pe. 4" x REE IN whis's 006 lower back rail 2 pes. rx Be” KE O05G occ ces for drawer support softwood 3.gcs. 96° x 256" = 13967 ..00 2008 for oe mupert softwoo OS ee 5 eed be” ey partition 1 pe. Yn = 1 2 x29 aoe front of drawer support Pe Sox $8 xiataes sc ccccciclecne ack late el oe let 2 | A a eee end slats Pe, “Sek Se BOR eo 0ccscecewe top of pockets _— 30% : ao 4 = seb cease ends of a pcs. x 2 de ey ee aaa shelves 4 pes. Zn i Bie 0c OUR 000500 000000% ones ~ softwoo 2 pes. 34% x 434" K 1355". .ccccccceres drawer backs softwood Sigcs. 3° x 1656" x 1856" <0. orccces drawer bottoms softwood These mill sizes are exact. Any errors will necessitate the purchase of more lumber. As is usual with these problems, begin the construction with the legs. Remem- ber to carefully lay out the mortises in pencil before gauging and scribing. Cut the mortises—after first boring them out with a bit—perfectly square with the sur- face of the leg. Fit the corresponding tenons on the rails and stretchers and cut the little mortises in them for the slats. After fitting the slat tenons into these mortises, glue this much up. Next, con- struct the drawer supporting frame, as detailed, gluing the one inch strip of oak on the front edge. The drawer partition can be screwed onto the frame through the bottom of its middle member. To hold this frame in place, screw through it, diagonally from the inside, into the end rails and the back rail. In a similar manner, fasten the lower shelf in place. The top is held in place with right angle irons, or, better yet, with table top fast- eners. The top shelves, or pockets, are constructed as detailed, and nailed to- gether with brads the heads of which will be set and filled later. The shelf back is also detailed, and is held in place by screws put in from the under side of the Zesk top. The pockets are fastened to this back by screwing into them through the back. The two large draw- ers are built as usual, and should be just loose enough to slide easily into place. This will complete the construction, and the next step is the finishing. Be very sure that you clean up the wood thoroughly before starting this very im- portant part of the building. By “clean- ing up” is meant the scraping and sand- papering off of all glue, dirty spots, roughed up grain, and chatter marks. One word about sandpapering oak. Never use a coarse sandpaper, as you will probably tear up the soft part of the grain, thus forming large pores in the wood that are hard to fill in finishing. Number 00 or number 0 is coarse enough, and be sure to wrap it over a smooth faced block of wood. A somewhat different mode of finish- ing will be suggested. In the usual way, a coat of stain is applied, followed by a coat of filler. But these two can be combined in one, thus saving a little time in the finishing process. Paste filler can be obtained from the manufacturer in cans of the natural, antique, golden, or weathered effects. These colors are all good, but, if the craftsman desires a different shade, he can thin out the natural paste filler with the desired color in an oil stain. The colored filler can be thinned with good turpentine or benzine, and it should be of the consistency of varnish when ap- plied to the wood. Work it well into the grain with a rather stiff brush, and allow it to stand until it has lost its gloss. Then rub it, also across grain, with a pad made by gluing a piece of leather onto a block of wood. Wipe off all filler above the surface with tow, or a piece of old cloth. Remember, all rubbing and wiping must be done across grain. Give the filler at least thirty-six hours in which to dry, and then go over it lightly with number oo sandpaper. Examine the grain carefully—use a magnifying glass if necessary—to see that the pores are well filled and no pinholes visible. If any defects of this kind are noted, it is well to go over the surface with the filler a second time, but have it of thinner

Page 111

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 507 5 STOCK 1 Sa ean tania emacs

bs SHELVES OR POCKETS

a " 7 pony W-T ae aaa H l rn ‘ t H l | ait —>3 +2 5% pres [fr C | = cs ae UF Cial 7 «| 1 r | = J < : 205 at oo ’ u i ie i a Lj

DRAWER SUPDORT

QO Vg DRAWER PULL DETAL oF PLATE

k—e—j bs+ Ww

Various details of the desk wile, showing especially the upper portion of this piece of furniture, the rawer support and the drawer pull.

Page 112

508 POPULAR SCIENCE MONTHLY AND WORLD'S ADVANCE

DESK TABLE

t

} a DETAIL DRawre ' i “1 [Sa> — re ~ i | y kK— 1 ——-+ ‘8 A f | SHELF Top i Ww

Additional details of the desk table, as including a dimensioned drawin the appearance of the piece of furniture w of the complete assembly as well en finished,

Page 113

consistency than at first, and repeat the operations of rubbing, wiping, and sand- papering. Next apply one or two coats of white shellac, rubbing down each with fine sandpaper. If you desire a wax finish, apply a coat of good prepared wax, allow it to stand over night, and rub it toa high gloss in the morning. If a varnish finish is preferred, apply a coat of good hard oil varnish over the shellac coats, and, after two days, rub it down with Num- ber oo steel wool. Apply a second coat, and rub it down with pumice stone and water. This will give an agreeable dull gloss. Ifa polish is desired, rub the last coat with raw oil and rotten stone, and polish it with sweet oil. This finishing varnish should be one of the many brands upon the market that is not af- fected by water, as the top of the desk will collect more or less ink that must be washed off, POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE _ 509 The drawer pulls may be purchased ready to attach, or the craftsman can construct his own. We have detailed the method on one of the drawings. Secure some Number 16 gauge soft copper or brass, and two solid rings whose inside diameter is about 114”. From the sheet carefully cut two circles 2%” in diameter. File the edges smooth. At the top of each, cut two small holes %4” long and as far apart as the rings are thick. Through these holes insert a strip of brass, with the rings in place, and spread their ends on the back like a paper fast- ener. Drill or punch six small holes around the edge of each plate through which drive large headed tacks to hold the pulls to the drawer fronts. The brass can be polished by rubbing it with steel wool, and applying a coat of ban- ana oil to prevent it from tarnishing. This desk table, if made carefully, should stand hard usage for years. Stairway in Closet Many small houses are built with an attic, but with no means of getting to it except by way of a trap door. Where a stairway is desired and hallway room is scant, a set of stairs on a condensed scale can be erected in the clothes’ closet ofa bedroom. In the house of the writer there was a closet 33 inches wide, 10 feet high and 6 feet long, with a door at one end. The ceiling of the closet was sawed out and two boards, 1x6 feet, were placed at an angle so as to reach from the floor, just inside the door, to the top of the other end of the closet. Thirteen steps of the same material were fastened between these boards on cleats. Each step overlapped the other two inches. The stairway was made only 16 inches wide, so that the shelves at the back of the closet, and also the floor, could be used for storage purposes. To keep out the cold in winter, a screen door frame was covered with canvas and laid over the opening, as a trapdoor. Contributed by MarGareET W. Moony. Easy Way to Make Large Envelopes Envelopes to suit any sized article can be easily made from a sheet of paper. Re- ferring to the drawings, 4 represents aa 4 — Ls] > v = = r! rT 4 1 4 e the object to be wrapped. To determine the width of the paper required for the envelope, the width of A should be dou-

Page 114

510 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE bled and a half inch added. For length, the paper should extend about 34 inch beyond one end of A and 1% inches at the other. After the paper is cut to the correct dimensions, it should be folded along the dotted lines, EE and FF. The flaps, D and L, should be glued down. Contributed by C. H. PETERSON. Home Made Fire Extinguisher A fire extinguisher of some kind should be placed in every workshop. Chemical extinguishers are the most ef- fective. One of this type which can be ger of the bottle exploding as the walls are thick enough to withstand a high pressure. The effective range of the syphon-extinguisher can be greatly in- creased by soldering the tip of an oil can to the nozzle. Contributed by J. F. Bircuter. A Book Cover A protective covering for the binding of books can be made from strong draw- ing paper. It should be cut about one and two-thirds times the height and length of the book. The two edges of the long side should be folded inward, and one end slipped over the end of the constructed’ easily and cheaply is de- scribed below. In a syphon bottle a %4-inch layer of sodium carbor.ate crystals is placed. The bottle is filled 34 of the way with water containing one ounce of sulphuric acid. The metal cap is then screwed tightly in place. Carbon dioxide gas forms slowly as the crystals dissolve. By using crys- tals instead of powdered soda plenty of time is provided to screw,the cap in place before the charge forms. Sufficient gas is generated in the syphon to expel the liquid contents at considerable pressure. There is no dan- book binding, as indicated in Fig. 1. The other end should be brought around to the other cover and slipped on. This covering has an advantage over the usual type, as it will not slip off easily. Contributed by C. H. PETERSON. A Lamp Bulb Magnifying Glass A magnifying glass of strong power can be made by filling a burned out lamp bulb with water. The bulb should be submerged in a basin of clear water and the tip broken off with pliers. The

Page 115

vacuum will cause the water to rush in through the small opening until the bulb is filled. Distilled water is preferable. Contributed by S. TonNER. Clothes Pin for Lamp Cord Adjuster In the cellar and attic, where elegance is not essential in electric lighting serv- ice, a clothes pin can be used in place of the expensive lamp cord adjuster. The cord is looped and forced into the slot between the lines. Contributed by WALTER FRANSEEN. To Whittle ‘‘Carpenter’s Knot’’ The “carpenter’s knot” is a compli- cated structure of small blocks of wood, correctly whittled and glued together. Six sticks of wood are necessary. Notches should be cut along their edges as shown in the accompanying drawings. To assemble, place numbers 2 and 3 vertically on either side of No. 1 at its center. Place numbers 4 and 5 on either side of numbers 2 and 3, resting the notches in No. 1. This leaves their third notches open, forming an opening with the space left in numbers 2 and 3 into which No. 6 is snugly pushed. Unless one is acquainted with the structure, dis- sembling the carpenter’s knot is a dif- ficult task. . ‘ Contributed by L. K. Hattock. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ae B:) ZaeNG T J SS eZ S AZ ~ : SS 2A SS 22 ~ SS? S = |AXA, JE 4 Ingenious Container for Harness Thread A rat-proof holder for harness thread can be made from a small tin can with a hole cut in the top, through which the thread passes. The end of a clock spring, one edge of which has been sharpened, may be soldered to the top to serve as a knife. Contributed by J. G. LunpDHoL”M. Inexpensive Lawn Sprinkler The parts necessary in the construc- tion of the lawn sprinkler shown in the accompanying drawings are as follows: 2 %” elbows. ¥y” x 1Y,” nipples. ye” x 214” nipples. ¥e” cross tee. ye” tee. Ye" x 1” brass washers. 3¥e” pipe caps. These should be drilled with two 3/32” holes, 5/16” apart, center to center. 1 3%” pipe, 12” in length. This should be tapered to a point at one end. It serves as the standard, and is to be driven into the ground. 1 %” x 5%” round brass rod. 1 %” x 8” brass disc. The edge should be divided into 21 equal parts. With a hack saw, 21 3” slots should be cut toward the center. The blades thus formed should be bent upward, thus forming a fan-like wheel. The brass washers should be soldered to this wheel, one on each side, to act as bearings. Nd He Wh Fein aoe

Page 116

512 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Ue A ty i i | The various parts should be assembled as shown in the drawing. When the water is turned on, the wheel will revolve and scatter water to a considerable dis- tance. Contributed by Henry G. SMITH. Mending Broken Glass Article Articles of glass, such as tumblers, fruit dishes, lamp chimneys, globes and other similar bric-a-brac, can be mended when broken with the following prepara- tion: Take five parts of gelatin to one part of a solution of acid chromate of life. Cover the broken edges with this and press together, then place in direct sunlight for a few hours. The mended article will not come apart even if washed in boiling water, nor will the breaks show. Try it! Contributed by CLARENCE T. HuBBARD. Handy Attachment for Auto Horns Most makes of cars have the push button controlling the horn placed on the inside of the frame at the side of the driver’s seat. This puts it in a most in- convenient position. To improve mat- ters, connect one side of the button to any bolt on the auto; the other terminal being led up into the driver’s glove and screwed firmly to same. A break is made at the cuff of the glove and a small slip socket inserted in the line. At the tip of the little finger, where the wire ends, solder a small ring of metal; when this ring is brought into contact with the nearest part of metal on the steering wheel the horn will sound. Contributed by Aucustus SAULTIS. Fire Alarm for Hay Lofts An alarm system which will give prompt warning when a fire starts in a hay loft may repay by a saving of hun- dreds of dollars the few minutes of time that are required for its construction. A one-point battery switch is mounted on one of the beams near the roof. Wires lead from it to batteries and a bell which should be located some place in the house where it can be heard read- ily. A light string should be stretched from the handle of the switch to the op- posite side of the loft. A rubber band or light helical spring, pulling in the op- posite direction to the cord, should be stretched to a hook behind the switch. When the string is taut, the circuit re- mains open and the bell does not ring. A fire will quickly burn the string, releas- ing the switch handle, which is: drawn back to the contact point, and the bell rings the warning immediately. Contributed by WILLIAM WARNECKE. Sena hubber bong SG)

Page 117

For Practical Workers An Exciter for Electrostatic Experiments By H. John Gray ORKERS in the fascinating field of electrostatics, often termed “frictional electricity,” will find the appliance described below very useful for many purposes. It gives a continuous stream of tiny sparks, either positive or negative tion, holes being made in the center of each and bushed with short lengths of brass tube, no longer than the thickness of the rods. The ends are strengthened with shorter pieces of ebonite, DD, drilled lengthwise to accommodate wires and projecting a lit- as desired, and is es- pecially useful for exciting larger ma- chines, charging proof panes, etc., without the bother associated with the use of an electro- phorous. Exact dimensions will not be given, but an overall length of 9 or 10 inches will be sufficient. The elec- tricity is generated by the rotation of a disc of ebonite be- tween two fur rub- bers, the former becoming negatively electrified and the latter positively. tle beyond the longer strips. To these pro- jecting ends two large brass balls, E and F, are securely fixed. Bedstead knobs or certain kinds of door han- dles answer the pur- pose very well, but. the surface must be plain, not fluted or ornamented in any way, and should be made quite smooth and bright. The rubber and _ collect- ing points are shown at G and H. The details of the disc and rub- Details of a simple static generator that may be used ber are shown in Fig. I shows the in experimenting with this form of electricity. Fig. 2, where A parts. The ebonite disc, A, which may be about 3% inches in diameter and thick enough to be rigid, is mounted on an axle, B, the ends of which form handles. The neces- sary support is given by two strips of ebonite, cc, about 14 inch square in sec- 513 is the circle of ebonite perforated at the center, B, to take the axle, the rubber being shown in position at C. This is made from a piece of thin sheet copper, cut to the shape shown at D, and having a few inches of copper wire soldered to the

Page 118

514 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE middle of the narrow part. It is im- portant to file the edge quite smooth, as well as the solder with which the wire is affixed. If any sharp points are left they will cause a loss of electricity. Two small pieces of fur, such as mole- skin, should be attached with glue to the crescent-shaped portions of the copper, on the side opposite the soldered wire. When dry the rubber may be bent to press lightly against both sides of the ebonite disc when in position. A small collecting comb, Fig. 3, will be required to collect the charge from the surface of the ebonite disc. This can be made from stout brass wire bent as shown and having two pin points sol- dered to each end. These must be of exactly equal length. A few inches of copper wire must be soldered to the frame for connecting with one of the -brass balls. The separate parts having been pre- pared, they may be assembled in the fol- lowing order: A length of straight, stiff brass wire should be used as a handle and passed through both the ebonite strips with the disc in between. The latter should be held firmly and must rotate quite true, so as not to touch the supporting strips on either side. A pair of tiny metal or wooden washers will give sufficient strength. The ends may then be bent carefully to form handles. Inside each brass ball solder a short piece of copper wire, with the ends outside. Thread the wire from the rubber through one of the ebonite end pieces (D, Fig. 1), and twist the end tightly to the wire projecting from one of the balls. Connect the collecting comb with the other ball in a similar manner. It only remains to fix the ends securely with the brass balls in position. To do this first secure one of the end pieces in each ball by partly filling the latter with pitch. The ends should be bound firmly with stout sewing silk. The rubbers and collecting comb will be approximately in position, but should be adjusted and firmly secured. The rubber should grip the disc firmly and be fastened with two small pads of leather or strips of india rubber, one on each side. Both sides of these should be coated with bicycle-tire cement, to grip both the copper segment and the inside of the ebonite frame. To adjust the collecting comb, the pin points should be set rather close to the disc, but not touching it, as the latter rotates between them. It may be held in this position by means of two strips of strong adhesive tape. The instrument is very simple to use. If positive sparks are required grip the negative ball in the left hand and turn the handle, presenting the positive ball to the apparatus to be charged. If a negative charge is wanted, simply re- verse the ends. It will be found con- venient to mark the balls so that their polarity can be seen at a glance—the rub- ber end being positive and the comb end negative. As electricity of both signs is produced one of the charges must be conducted away through the body of the operator. The machine is only intended to give quite small sparks, but it is much too powerful for charging a gold leaf electroscope. Difficult Small Castings Occasionally the experimenter has need of small castings of intricate shape which would hardly warrant the mak- ing of core prints. The pattern is first made in wax procured from any dentist or dental supply house and carved into proper shape with the aid of a slightly warmed knife. It is next smoothed down to a glossy finish with gasoline or commercial chloroform applied with a pledget of cotton. Then a mixture of one part sharp sand and three parts plas- ter of paris is made and the pattern covered with it. This investment should have just enough water in it to make a thick, creamy mass. Cut a pouring vent through the plaster so as to expose the wax. Place the investment in boiling water until all wax is out of the mold and heat in oven till very dry, then pour the metal through vent. It is an advan- lar) nm orwm eo — wi @ of} FF ETD

Page 119

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 515 tage to make o r two air vents to the cord, pull the trigger, release the allow the tog “at a es to ee spri a and the switch handle will be |" when pouring. thrown bi Contributed by Contributed by AUGUSTUS SAULTIS. E. A. Hopcson. | . " ; A magnet hae ‘hat wil hl Time Clock i Lights at shin: Willen sue tata erate window at any desired time. A kn ‘fe : pe e han amabeenmaninn TS x SB hn i UE t i. — q ‘ 1 i i | Lo i i 3 = t ' i | q s\!) | | | \ | Hh HTL |) HHL HI UL Hl LA can be made indin oO a ne pity — A try square can be used as a marking oiaeen © dictneas ea prepa indexed "The knife h is connected in the rem TE beter: ee 5 = ( Racoon tices im viding ey o th recente | — i

Page 120

516 blade is cut with notches to correspond to the numerals. A marking groove can be cut in a board by placing the point of a nail in one of the notches. Contributed by F, M. DEFANDORF. Wiring Diagram for Converting Motor to Dynamo, or Vice Versa A wiring diagram is shown herewith by means of which a power motor may be converted into a dynamo, or a dynamo into a motor. To use either as a motor or as a gen- erator, the line switch must first be thrown in. To use as a motor the four- line Sw -= Lime | 76 46 46 Pad “ruses Starting 00a Shut Armoture Shut held pole double-throw switch is thrown to the motor side, and the motor is started with the motor rheostat handle. To use as a generator the four-pole double-throw switch is thrown to the generator side. The voltage may be reg- ulated by the generator field rheostat. The load may be varied by separate switches, not shown in the diagram. Contributed by Epwin J. IsRAEL. Driving Nails Under Water An ingenious method of driving nails under water is shown in the accompany- ing drawing. A nail is placed, point out- ward, in the end of a length’ of gas pipe over the spot where the nail is to be POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE a A stiff rod is inserted in the hole of the pipe and struck with a ham- mer until the nail is driven entirely in. Contributed by HERBERT BAMBRICK. driven. To Repair Broken Celluloid Broken celluloid articles can be re- paired with a cement properly form- ulated. The broken fragments should be cleaned thoroughly with soap and water, and when dry, painted at the fractured edges with Acetone of Merck. The Ace- tone will blow between the cracks, soft- ening the adjacent celluloid. After a few minutes, the liquid will evaporate, and the joint harden. Contributed by FRANK R. BENNETT. Clamps Boards Without Marring If two “S’-shaped wooden cleats are screwed pivotally to the top of a work owt om to bebe TR pee ae ae ee a ee ae a ae Poa ae eT

Page 121

bench, mahogany, oak and boards of similarly expensive woods can be held firmly without their surfaces becoming marred. The cleats may be set at any desired distance apart, to accommodate boards of any thickness. E. B. W. Contributed by Menominee Ny Oil and Water Separator In many places, especially in the oil fields of this country, petroleum collects about the wells and finds its way into small streams. The amount of the oil is often not worth saving, but it is car- ried away where it does damage often to the extent of lawsuits. The usual preventive method is to build dams, draw the water off at the bottom, and the oil at the top. This method is expensive and not satisfactory. The accompanying illustration shows a separator that may be constructed cheap- ly. Oil and water enter the side of the tank, or separator, under a head of sev- eral feet, so that it is injected into the tank with some velocity and in such a direction that the fluid in the tank will whirl. This whirling motion throws the water to the outer part, while the oil col- lects on the top of the water and in the center. The water is drawn off at the outer edge and bottom of the tank and pumped up to a “laundry,” the bottom of which is an inch to three inches below the oil outlet. The outlets should be of suffi- POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 517 cient size to cause no backing of either fluid in the separating tank. Contributed by RosBert W. PHELPs. ere, Boring Holes with Aid of Inductance It is frequently necessary to bore holes through floors and partitions when an extension bit is not available. In such = 3S SS ss N = Hi I) an exigency the following suggestion will be of value. Cut two lengths of soft iron rod, 4 inch in thickness and 2 feet in length. Wind one of them, A, with two layers of No. 18 D.C.C. magnet wire. File one end of the other rod, B, to a point and wind it likewise with two layers of wire. No. 28 or No. 30 D.C.C. magnet wire should be used. The drilled hole in the floor or parti- tion should be as deep as possible, and the rod, A, inserted, previously being connected in series with a buzzer and dry cells. Rod B should be connected in series with a telephone receiver and moved about on the opposite side of the parti- tion until the buzzer can be heard loud- est. At this spot, dent the wall with the point of the rod and bore a hole. If care is taken the two holes will be ex- actly opposite. Contributed by A. SUHER.

Page 122

518 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Hints for Workers in Iron By means of carbolic acid a hole 4 inch in diameter has been bored through ¥Y%-inch thickness of cast iron, with a common carpenter’s brace; judge, then, what can be done by using the acid and a pressure drill. To scale cast iron mix one part of sulphuric acid with two parts of water; brush the solution on the iron with a cloth until the surface is wet well. Af- ter nine or ten hours wash the surface with water and the scaly surface will have disappeared. To make cast iron take a polish like steel, treat it in the following manner: Dissolve in one quart of hot water one ounce of copper sulphate, one ounce of prussiate of potash, one ounce of charcoal, eight ounces of salt and then add one gallon of linseed oil. Mix well and after bringing the iron to the proper heat cool it in this solution. To tin cast iron cleanse it well and then rub it with a coarse cloth dipped in muriatic acid. Then, with the same cloth, rub it with French putty, which may be made by dissolving in mercury all the tin filings it will hold. Contributed by M. F. FLavIAN. ——$—_—____ Casting Aluminum Nearly every experimenter requires, at one time or another, castings of ir- regular objects, and as very few people have the apparatus necessary to pro- duce the heat required to fuse the harder metals, such as iron, brass and copper, most amateurs resort to lead. In many cases, lead is quite satisfactory, as, for instance, in objects requiring no great strength, and not subject to heat or re- quirirg considerable weight, such as keels for boats, weights and plugs. In a great many cases, however, a harder metal is very necessary, as in stove doors, ir- regular supports, bases, containers for certain instruments, and thousands of other objects. In such cases aluminum can generally be used with satisfaction. There seems to be a general idea that aluminum requires a high temperature for melting. In reality the melting point of aluminum is comparatively low, about 650° F., for pure aluminum, as a matter of fact, is readily melted by the heat from an ordinary coal fire. It is, of course, necessary to make the fire burn briskly by giving it plenty of draft. The aluminum can be melted in an iron or brass ladel. As aluminum dissipates heat very rapidly, it must be handled rather quick- ly, but if melted in a heavy ladel the metal will remain in a liquid state for some time. Because of the exces- sive shrinkage of aluminum, it is neces- sary when casting to allow for this loss either by the use of an oversized pattern or, in case an open mold is used, by add- ing aluminum as the casting cools. Aluminum is strong and tough, and is maleable when cold. In repairing broken parts of any metal with aluminum, al- though great difficulty may be encount- ered in an attempt to weld them, a great deal can be accomplished by cutting ex- panding cavities, filling them with alumi- num, and thus anchoring the pieces to- gether. Contributed by R. U. Crark, 3p. Helical Wire Springs Calculating helical springs is not such a difficult problem as a great many ma- chinists and draughtsmen imagine. A method is shown herewith, which has been employed in figuring springs, al- ways with correct results. The formulae for helical springs is taken from Kent’s “Mechanical En- gineer’s Pocket Book,” and the values in the table are the results obtained from these formulae. The correct method of drawing springs is also shown and an example is given of figuring a spring for carrying 100 lbs., as a maximum load and to per- form its work in 2”. This spring is 9” closed and 11” semi-opened. Using this example as an illustration, square or round springs can be figured with little difficulty. Those who have had experience well know that a helical spring as wound on

Page 123

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 519 SE =" ° e . formulas for Helical Spring Wire kent) D= outside diam of spring S-use 60,000 Section from spring table W safe load carried in /bs. J use 50.000 for figured fram ‘Kents’ formulas F deflection of 1 col per one /b. continous work. ‘ D 1100 | 425 | 150 d aiom. of wire S$ 10.000-20,000 lbs. for brass.\ 7 \|W\/57 | 122 | 99 S fibrestress E 12,000,000 in — 5 wh fae E torsional modulus of elasticity calculating toble. #, twlesoleesli9s ik MW for 3g. SH. = 1.2+I0.1n table F for sg.st! fig in table. 59 |_.204 | F |.00037|.0005/,0008 i P(0-¢)? Ed4 F for brass = fig. in table 2 ei for square steel = sigh F = 4.7/2 Sd! _.3927%60,000077' P(0-d)?_ 8+ 1.0737 for round steel Wy = 3927 5-F = we Wz2lbs. F= 87 a * sana 00083 Cer. Method of Drawing Springs + ~Pifch tlre igi Ten 5100 SPLIOGS — . L_~ free length———| Method of squaring ends (ye yor ting coils & pitch _ fe Before squaring ends Size of rod over which t spring is to work Sering moker requires — free length , — -_. coils sia sileasiaet iaies Outside il Compression spring ize and kind of wire Lxam ple ped deflection ” erm open 49.63/bs. “ . | C yr /dS. Moximun load 100 lbs.ond = za= 50.84 coils = : = 09.197 whe 47.84 working coils ‘ S cous def bs 3.97" total deflection ~ e =: . 47.84x.00683 « 1003.97" total deft. = p 12.97’, free length [ = , 11.00 pee! /00 1.97" MW S€/71/ ape —49.63 ———————— =: 49.63 /bS. fe £68 00083 = 47.84 J’ closed PrOOl = “50 57 47.84».00085 +2" 2° difference Problems Problem "1. Draw compression spring OD. and 10f" free length, #3 .244') mire 29.8 working coils 8"closed and 9" serni open, pitch #" This spring to perform its work in one inch. Problem *2:. Draw tension spring QD. 4" and 7Y* free length, 4, (=.244°) WITE $0 working corls. Problern *s:. Draw compression spring QD. if’ and ef" free length 2s working coils 4 Square spring steel,wire, pitch §°. This spring fo perform its work in J inch. Problem *4:. Figure spring in problems similar to example using 250 /bs. for max. lood. _ to work from sou'-f 00. _3.00 cotls for squaring ends

Page 124

5 -00053 | .0007!|.00094 |.00/2 |.00/86 | .00276 |.0053 |.0052 20 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE HELICAL WIRE SPRINGS (ow wre) t ) .20 25 3125) | 375 .4375 |.500 5625 |.625 |.75 875 \1.00 28 Ww |.524 41 3/ ar 25 .20 A175 = |.16 3 ot .098 016" | F .0632 |./302 |.302 |.470 |.760 4150 _\|1.66 |2.30 4.02 |.6.95 |9.42 7 D 25 3/25. |.375 |.4375 |.500 |.5625 |.625 |.75 .875. 1100 1.125 24 | Ww \4.18 92 .76 .45 56 50 .45 .37 3! .28 .24 0225" | F .0278 |.063! |./135 |./875 _ |.282 |.408 |.569 |.975 |1.660 |2.42 |3.46 Zt o 25 3125 |.375 |.4375 |.500 1.5625 |.625 |.75 675 7.00 |4125 -. Pe 2.35 |1.84 1.49 11.26 4095 \.96 665 |.7/5 -6/ . 53 .47 028 F -0119 |.0250 |.0453 |.0742 |.//40 |./65 |.23! |.408 |.660 |.995 |/.42 t 7) 25 3/25 |.375 |.4375 1.50 $625 |.625 |.75 1.875 [1.00 4125 20 ,| |47 3.64 2.97 12.5 2.18 1.92 1.72 1.42 420 |1.05 1.93 055 f .00451 |.00952_|.0/75 |.0292 |.0447 |.065! |.09/4 |\./63 .264 400 |.575 7 D 125 3125. -'|.375 |.4375 |.50 .5625 |.625 1.75 875. |4.00 (4.725 9 || a 7.87 6.05 4.93 4.15 \3.58 |3/6 2.82 |2.32 497 1748 454 041 la 00234 |.0047_ |.0088 |.0/06 |.0228 |0334 |.04/0 |.842 |.1370 |.208 |.305 t 0 25 3/25. 1.375 |.4375 |-50 625 75 .875 |/.00 11/25 11-25 “oe. \e 12.05 |9.2 7.4 6.57 | 5.4 4.23 3.48 2.95 |2.85 2.27 2.02 .047 F 00115 |.00294 |.00488 |.00824 |.0/32 |.0/87 |.0396 |.0785 |./26 175 . 242 t o 25 \.5/25 1.375 .50 625 |.75 675 1.00 L125 |h25 1.50 7 |W 18.9 14.3 US 8.3 .647 15.32 4.5 3.91 3.45 |3./ 2.56 -054 a 00059 _|.00/38 _|.00256_|.00702 |.0/45_|.0267__|.0437__| .067 20971 __|.1§02 _|.228 t 0 25 375 50 .625 |.75 675 1.00 4.125 |1.25 150 RIS 16 " 3.5 18.8 13.8 10.5 8.57 17.25 6.28 5.04 4.96 4./ 3.50 063" | F .000 .00122_|.003!__|.00704 |.0/29 _|.0233__|.0327_ |.0476 |.066 |.//8 ./90 t 0 375 500 .625 |.75 -675 |400 7/25 |125 1.50 |175 2.00 s iw 29 20.5 15.85 |12.92 |10.9 9.46 8:35 17.45 1675 5.25 4.53 -072 F .00066 |.00/8 |.00404 |.0074 |.0/24 |.0/89 |.0279 |.039 -0697 |./16 .204 Q 7) 375 50 625 1.75 .875. 11.00 7/25 |1.25 |7.50 |475 12.00 4, W 41 28.2 22.2 18. 15.2 13.15 \1.6 \10.35 |86.52 17.25 |6.3 -08 F .00041 |.00/28 |.0034 |.0057 |.0082 |.0/27 |.0186 |.026 |.0548 |.0757 |.1/6 7 0 500 |.625 IS 875 7.00 1125 1.50 1.75 12.00 12.25 |2.50 3 iw 45.7 35 26.4 23.8 20.3 |/6./5 13/5 111.25 19.72 18.65 17.75 .092 F 00063 _|.00/4 _|.00266 |.0045 _|.0072 |.0/48 |.0266 |.0425 |.0658 |.08/ |./3/ tf a 625 75 .875 7.00 125 150 175 2.00. |2.25 12.50 2.75 in A 52.5 42.2 35.4 130.4 23.8 19.5 |16.6 14.4 12.7 4 10.3 /05 F 00069 _|.00/48 |.0026 |.0039_|.0083 |.0/49 |.0245 |.0574 | .0545 |.0734 |./02 £ D 75 875 1.00 1.25 7.50 |175 2.00 |2.25 |2.500 |2.75 |3.00 7] w 65 54 46 36 29 25 22 19 17 19.5 14 .120" | F 0008 |.00/3 |.002/9 |.0046 |.0084 |.0/39 |.02/3 |.03/1 |.0433 |0.568 |.077 r} D O75 1.00 7-25 |1.50 775 |2.00 2.25 12.500 |2.75 |3.00 |3.25 10 n" 77 67 52 42 36 3! 27 24 22 20 18 135" | F 0008! |.00135 |.0027 |.005/ |.0084 |.0129 \.0/91 -0266 |.0358 |.0475 |.0608 Zt D 100 125 L375 |/.50 1.75 2.00 2.25 |2.50 |275 3.00 |3.25 350 $ Ww 90 69 62.4 |56 47 4! 38 32 29 27 24 23 /46" F -00085 |.00/9 | .00257 |.003/7 | .0056 |.0078 |.0/3/ |.0/8 .024 -O3/3 |.0413 |.0522 z D 7.00 1.25 7.375. |1-500 |1.75 2.00 12.25 12.50 |2.75 3.00 13.25 3.50 ~~ - W 120 98 82.5 76 64 55 49 43 39 36 33 30 /62 F -C0057 | .0012 -00173 |.002 |.0055 |.0059 |.0088 |.0/26 |.0/168 |.022 |.0285 |.0364 t 0 1.00 1.25 7.50 1.75 2.00 12.25 2.50 2.75 3.00 3.25 3.50 7 W 159 122 99 63 72 62 56 si 46 42 39 77" 1 F -00038 |.00083 |.00/5 |.0026 |.0041 |.006 .0083 |.01/5 .0154 |.0/96 |.0249 t 0 1.25 1.375 17.50 175 2.00 12.25 2.50 |2.7§ |3.00 [325 13.50 14.00 eo " 158 141 128 107 92 6/ 72 65 59 55 50 44 192 f -00057 |.0008/2|.00/! _|.00/8 |.0028 |.0042 |.0059 |.008 |.0107 |.0/38 |.0/74 |.0266 t 0 1375. [4500 17.75 2.00 |2.25 |2.50 |2.75 13.00 3-25 |350 4.00 |4.50 + Fe 173.6 |I5S5 131 3 99 88 80 70 67 6/ 53 47 -205 F -000604|.0008 |.00/4 |.0022 | .0032 |\.0041 |.006/7 |.0082 |.0/06 |.0/134 |.0222 |.0298 7 7) 1375 |1600 \|7.75 [2.00 |2.25 |2.50 |2.75 | 400 3.25 350 4.00 42.50 4 |" 233 2/0 175 |150 132 118 106 97 89 82 7 63 225 f .000408|.00055 |.0009 |.00/5 |.0022 |.003 -0041 |.0065 |.0071 |.009) |.073 .0202 : 0 1.50 175 2.00 |2.25 12.50 |2.7F |3.00 [3.25 3.50 |4.00 |450 3 | 250 225 195 170 157 136 125 114 105 88 80 : wd -00037_|.0005/_|.0008 |.00/2 | .00/98 |.0029 | .0039 |.005/_|-.0065_|.0086 |.0//6 7} D 1.50 1.75 2.00 12.25 2.50 |2.75 |300 3.25 3.50 14.00 |450 5.00 2. eo 345 290 250 2/5 192 175 156 146 134 Ws 100 90.5 .263 F 00026 |.00046 |.00073 |.00/1 .0015_|.002/ |.0027 |.0037 |.0047 |.0072 |.0/06 | .0/48 t 0 175 2.00 2.25 |@50 [2.75 [3.00 |3.25 3.50 4.00 |450 |500 / P ” 360 3/0 279 240 275 195 180 165 145 127 Ws -263 F 0003! _|.00055|.00078|.004 |.00/5 |.002/ |.0027 | .0034 |.0053 |.0077 |.0/28 7 0 175 200 2.25 |2.50 12.75 [3.00 [3.25 [3.50 |4.00 |450 |5.00 o |W 470 400 350 3/0 280 |250 230 12/2 185 162 145 -307 f -0003! |.00038 | .00055 |\.00079|.0011 |\.00/5 |.002 |.0024 |.0033 |.0055 |.0077 7} 0 1200 2.25 |2.50 (12.75 3.00 |3.25 3.50 14.00 |4.50 |5.00 |5.50 oo | 510 445 |390 350 320 |290 270 230 205 183 165 33/ la 00029 _|.00039 |.00056 |.00078 |.0010 |.00/4 |.00/7 |.0027 |.004) |.0056 |.0075 ft iy 2.00 2.25 2.50 |275 3.00 [325 [3.50 4.00 |4.50 |5.00 |5.50 000,\ W 700 6/0 |540 |480 435 |400 365 315 280 250 225 362 a .000/7 |.00026 |..00038

Page 125

an arbor in a lathe may be of a given length, but that after it is taken from the arbor and compressed, coil to coil, it will not come back the same length as previously wound, on account of the “set,” which takes place in the spring. For example, a spring which is made of %4” round spring steel 3” in diameter on the outside, having nine coils and measuring 6 11/16”, when compressed coil to coil would, after compression, measure only 63@”. Therefore, that spring had a 5/16” set, or was shortened by that amount, and in constant use the spring would always open 63g” in free length. The spring above referred to was wound cold. After a spring is wound and the end squared, it should be baked in an oven heated to a temperature of 400° to. 500° Fahrenheit, for a period of from one to two hours. This tempers the spring and prolongs its life. The accompanying table was figured from a Kent formula and gives the out- side diameter, which is indicated by D, the safe load, which is indicated by W, the deflection, which is indicated by F, and also the size of the wire. This table is for helical round wire springs and values for square wire springs may be easily computed by using the following constants : F in the table should be multiplied by 59 and W by 1.2 to find values for square wire. Contributed by F. B. Extiott. An Automatic Gas Lighter An automatic gas lighter for a small gas heater which is turned on and off POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 521 frequently, can be made by drilling and tapping the valve or pipe on the intake side of the heater valve, to accommodate an 8/32” machine screw. A piece of brass or copper pipe, 1%” outside diam- eter, is threaded with an 8/32” machine die. This pipe is connected to the intake side of the valve or pipe, bent into the hole provided for lighting the heater, and extended until it reaches the first tip. A small flame can be had -by denting the pipe with a pair of pliers. Contributed by C. P. CLEary. Pattern Maker’s Tool While walking through a factory the contributor noticed a pattern maker using a very handy tool. The device en- eS a Fig.t - oe = o— Fig. 2 abled him to round the edge of a pat- tern, taking off the corners a little bit at a time and with the greatest ease. The tool was made from a piece of 1/16 inch strip steel about 34 inch wide and 7 inches long. The strip was bent into a long “S” shape as shown in the illustration, and the two holes, one in either end, ground in the curved portion to form an elliptical opening with a cut- ting edge. The size of the hole deter- mines the radius of the curve which is to be cut in the rounded corner of the pattern. It is, therefore, advisable to make up a number of the tools fitted with different sized w gan: in order that various classes of work may be accom- lished. The method of using the tool is clearly shown in the illustration. Contributed by Ep. Hart. ————

Page 126

522 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE

== a ESSSzESzESSzEEZZE! ——— ——S S—=_=z EE aL

A Rivet Holder In riveting the seams of tubes having small diameters, considerable difficulty is usually encountered, because the rivets cannot be held in place. This can be - overcome by using the tool illustrated in the accompanying drawing. A strip of stiff metal is bent in the center and notched at one end. The rivet is insert- ed in this notch and slipped into the de- sired hole in the tube and held firmly. Contributed by Geo. T. Cooper. Babbitt Rivets for Mending Pans Small holes in tinware can be mended with rivets made of babbitt metal in small slugs. The slugs should be inserted in the holes and flattened on both sides. Contributed by Leo M. LaFANne. Method of Babbitting Bearings The method suggested herewith for making a babbitt bearing has been used with great success. A short length of shafting is used for the babbitting man- drel, the diameter being the same as that of the shaft to be used in the bear- ing. A single thickness of

eae SEES] LZ _EH_EZU_TEE= = iq? —— — —=— << ees —4 should be somewhat greater than the length of the bearing to be poured, as suggested in the drawing. The mandrel is set up in place and the babbitt poured in the usual way. After re- moving the mandrel, the bear- ing surface will be found to be smooth and clean; therefore, very little scraping will be required, as the paper-covered mandrel makes the bearing with just sufficient clearance to produce a good running fit. Contributed by

Jomn LEarFstrom. A Makeshift Die A die to cut threads upon fibre or hard rubber bushings can be made from a nut having the desired sized hole and thread pitch. Four small grooves should be cut across the threads at equal distances apart. Contributed by CLARENCE H. ANDERSON, Substitute For a Jack Screw A 2/3 inch or 1 inch turnbuckle makes a very good substitute for a jack screw for leveling or raising light timbers, boilers, etc. The nuts on the ends of bolts should be set tightly with a lock nut or by welding to the shank of the bolt, so that the bolt cannot turn when it is placed against the object to be lifted. Contributed by T. N. Stocum.

newspaper is wrapped around the mandrel, the | ends of the wrapping _— Length of Bearing nel

being cut square and

made to meet as shown —- gee

in the illustration. The

ends of the paper are se- cured to the mandrel with thin glue or mucilage. The width of the paper

‘ » Method of Babbiting Bearings

Page 127

r Questions and Answers . i department will appear regularly in PopuLAR SCIENCE MONTHLY AND THE Wor.p’s ADVANCE, subject to following regulations: The questions must be legibly written with typewriter or in ink, on one side of the sheet. Each question must be definite and cover but one point of the subject under considera- tion although a letter can contain more than one question. On the roth of the second month preceding the date of issue of the magazine all the questions on hand will be considered, and those which are put in the most intelligent manner and of widest general interest will be selected for publication in such issue, the number be- ing governed by the space available. All other questions will be returned to: the writers with a statement of the price for which they will be answered by letter. Return postage must be enclosed with each letter containing questions, and the letters must be addressed to the Questions and Answers Department and contain nothing relative to other departments of the magazine. TESLA COIL. (22) C. W. C., New York City, asks: Q. 1—I have constructed a %-kw. Tesla coil and desire to use it with a %4-kw. coil type of transformer with a vibrator. I will use six Columbia dry cells. How many glass plates, each 8 in. x 10 in., coated with tinfoil 6 in. x 8 in, will it be necessary for me to use? A. 1—With the type of coil which you mention it will not be possible to use much over 8 or 10 plates. Q. 2—Would a 6-60 storage battery be better than the dry cells? A. 2—The storage battery would be far preferable if the voltage were higher. Use an 8-60 or a 10-60 battery. Q. 3—How large a spark should I obtain? A. 3—We doubt if it will be possible for you to obtain over a six-inch spark. RECEIVING SET CONNECTIONS. (23) R.S., Carlisle, Pa., asks: Q. 1—Is the enclosed diagram of connec- tions satisfactory to use with a radio receiving set! A. 1—No. Omit the battery B and the condenser C. Place the detector where you now have the battery. Q. 2.—I have been unable to receive any- thing with the set as shown. Can you sug- gest anything which might be the trouble? A. 2—Yes. We would not expect you to receive with the present connections. Make the changes indicated and all should be satis- factory. ‘ eat there any large station near Car- isle? A. 3.—Arlington is sufficiently near so that you should hear them without difficulty. They send time signals at noon and 10 P. M. Also weather bulletins at 10 P. M. The wave- length is 2,500 meters. 523 TRANSMITTING SET (24) C. C. H., Abington, Mass., writes: Q. 1—He gives a large amount of data regarding his transmitting set, the essential features of which are: Aerial 90 ft. long with 35 ft. lead in, 1 in. spark coil with suitable condenser, quenched gap, and helix of vario- meter type. He says that he can get but four miles, but with just his coil connected in the aerial circuit he can get ten miles, and that his wave is not sharp. He desires to know what the trouble is and how it may be rem- cdied. A. 1—A small spark coil is very unsatis- factory when used in a tuned circuit. It has a high secondary voltage so that when put directly in the aerial circuit it is capable of radiating energy. But when so connected the damping is very high, due essentially to the high resistance of the gap. The radio law forbids high damping, or broad wave, so that it becomes necessary to use tuned circuits. The character of the secondary current and the small amount of energy of the spark coil available do not make satisfactory condi- tions of operation. Four miles is probably as good as you can expect to do with tuned circuits on a l-inch coil. Your aerial has a natural period of 200 meters or over, so that you will find difficulty in complying with the law unless you use a series condenser, and you have too little energy already to do that. Better cut down your aerial a bit. The quenched gap is of no advantage to you with a spark coil. You will get just as good results, if not better, without it. There is very little you can do to improve your efficiency and re- main within the requirements of the radio law. WINDING OF THE STATOR OF AN INDUCTION MOTOR (25) K. J., Canon City, Col., says: Q. 1—How to wind the stator for an induc- tion motor for a speed of 3,600 rev. per min.,

Page 128

524 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE to fit a 60-cycle 110-volt circuit? Stator sheet iron is 5 in. outside diameter, 3 in. inside, and the stack is 1%4 in. thick, and there are 24 slots. A. 1—If you mean to make the machine operate as an induction motor you will be lim- ited to a speed of about 3,300 or 3,400. Of course, the smallest possible number of poles is two, and while 3,600 rev. would then be the synchronous speed, the actual speed would be a few hundred less. If you prefer a series motor, requiring an ordinary direct current motor and commutator, you can get 3,600 rev. or more. In either case the stator would be wound for only two poles, but the amount of iron in the particular lot you have is insuff- cient for that magnetic arrangement, for the outside diameter should be about 1 in. more than at present. To make the case worse, the space lost by use of rivet holes is to be re- gretted. The best alternating current motors avoid this construction. If you utilize these holes be sure to use brass, not iron, bolts. To wind for two poles you can adopt hand-wound concentric coils or form wound over-and-un- der coils. In either case see if you have room for them within the frame. For the first sort wind a coil, say of No. 22 wire, filling slots 6 and 8, ignoring 7; then without cutting the wire, continue into slots 5 and 9; similarly in 4 and 10, 3 and 11, 2 and 12; finally a coil occupying half of slots 1 and 13. Opposite this group wind in similar manner a coil in slots 18-20, 17-21, 16-22, 15-23, 14-24, and a half coil in 1-24. If wound in exactly the same manner, the two inside ends are now to be connected together, the other two lead to ter- minals. The magnetic effect can be tried with direct current, the central teeth in one group being energized to a greater strength than those near the outer coils, the two groups be- ing of opposite polarity. The second method involves, placing coils in slots 2-8, 3-9, 4-10, 5-11, 6-12 and 7-13. The other group occupies slots 14-20, 15-21, 16-22, 17-23, 18-24 and 19-1. This method is frequently adopted in “univer- sal motors.” If you will be satisfied with the induction motor operation, the rotor can be of the squirrel-cage sort. SECRECY OF RADIO MESSAGES (26) R. O.S., Polo, Ill, asks: Q. 1—Would two No. 10 copper wires be equal to 1 No. 4 for a protective ground for a radio set? A. 1—No. It would be necessary to use 4 No. 10 wires to get the equivalent of 1 No. 4. Q. 2—Would an ordinary telegraph key fitted with dime contacts carry the current from a 1 kw. transformer? A. 2—Yes. Q. 3—Is it lawful to have a bulletin board for the purpose of printing the press news and weather reports that are sent out by Arling- ton (NAA) at 10.00 P. M. eastern time? This is to help inform the public that I have es- tablished radio reception from Arlington, and communication between neighboring communi- ties. A. 3.—It is lawful to publish such news as is sent broadcast for the reception and publi- cation of all who hear it. The weather re- ports and such allied matter may be published, but care should be taken not to publish any- thing sent to an individual station or group of stations. Press from WCC cannot be pub- lished. Q. 4—Does the length of ground lead cause a decrease in efficiency? A. 4.—Yes. Q. 5.—Is it advisable to use a variometer for long distance receiving? A. 5.—Variometers are very little used at the present time. WINDING FOR DYNAMO ARMATURE (27) F. B. R, Reading, Kansas, asks: Q. 1—What would be the proper winding for a 40-slot drum armature 534 inches in diameter and 3 inches long to yield a pres- sure of 12 volts? Slots are 4% inch by % inch. A. 1—As you did not state what speed was desired, we shall have to suggest one, say 1500 r. p. m., but if you prefer a slower speed, it can be arranged for by proportionately in- creasing the number of conductors. The size of slots proposed does not yield the maximum output, and the slenderer are the teeth the more effectually are the armature reactions, therefore the sparking, prevented. It will be an improvement to increase the depth to % inch, but if required, the width of slots could be reduced to .23 inch. Form wound coils will be used on armature, arranged for a four- pole field magnet. Let each coil consist of two turns of two No. 11 wires in parallel, giving four wires per coil, eight per slot. Woven-wire copper brushes in four places on the commutator will be necessary, and the allowable current will be between 125 and 150 amperes. Each pole shoe should have an arc of about 314 inches, and the cores on which the spool fits be of wrought iron about 2% inches in diameter, with a winding space 214 inches long. The magnetic yoke can be of cast iron of 5 inches by 1% inch section. CONNECTIONS OF SQUIRREL CAGE ROTORS. (9) F.P.A,, Lincoln, Neb., asks: Q. 1—Why is it that same three-phase in- duction motors with “wound” rather than squirrel-cage rotors have the “Y” point of these windings grounded, while others do not? A. 1—For one reason it makes a convenient starting point for the windings, otherwise a special copper ring is necessary. For a more important reason, it diminishes the potential difference between windings and core. At the moment -of. starting, there is induced in

Page 129

the rotor, in spite of the few turns in such coils, a fairly high voltage. Without the grounded center there would be the voltage due to two phases in series, but as thus defi- nitely attached to the iron, the voltage is that of one phase only. The same principle is recognized in ordinary three-wire direct or alternating current distribution systems from central stations, whereby only half the work- ing pressure is exerted between a line wire and the ground, thereby diminishing personal danger. SPARK COILS (28) M.C. O., Castle Rock, Colo., asks: Q. 1—I am 28 miles from Denver, 45 miles from Colorado Springs, and 85 miles from Pueblo. How many 6-60 storage batteries and what size spark coil would it take to reach to each of those places? There is no light plant or electrical power nearer than Denver. A. 1—For Denver you would require at least a 5-inch coil. Such a coil would probably be wound for about 20 volts. This means that you would need 3 sets of 6-60 batteries. To reach to Colorado Springs you would need an 8-inch coil. A 60 storage battery would be a little small for the coil, but if specially wound for high primary voltage it might be possible to use 60s. We would expect to use about 4 6-80s on it. To reach Pueblo you would need at least a 10-inch coil. You would require 5 6-120s to run this coil. On these figures of coils we have not allowed a very large factor of safety. Signalling by coils will be found to be expensive. Before actually building your set it would be best to go into the matter in great detail, for if you do not you are pretty apt to meet with an expensive failure. Q. 2—Where can I get information on the audion? A. 2.—Consult the back numbers of this magazine. If you have not a copy of the index one will be furnished you on request for the period desired. There have been several good articles during the past two years. RADIO REPORTS (29) E.L., Clarksburg, W. Va., asks: Q. 1.—Will you please tell me at what time in the evening Sayville, Cape Cod and Key West radio stations send their reports? A. 1—Cape Cod (WCC) sends press at 10.15. It takes about 45 minutes for.the com- plete copy. A break of 15 minutes is then given and the same matter sent the second time. A second break of 15 minutes follows and the matter is repeated for the third time. Say- ville has changed its time since the war broke out. Formerly they started at about 9.15 on 2800 meters. Now they start at 11.00 on about 4000 meters. Key West waits until Arlington gets through with the report which is sent at 10.00 and then. they send the same report as sent out by Arlington. POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE ELECTROMAGNET WINDING (30) A. E. K,, Mobile, Ala., asks: Q. 1—What would be the dimensions and winding for an electromagnet capable of lift- ing a weight of 75 pounds, the energy to be taken from a 10-volt 8-amp. dynamo? A. 1.—It is not difficult or expensive to make a magnet that will hold 75 pounds, but quite a different case if the distance through which the magnet is to work be even a fraction of an inch. A U-shaped piece of 1-inch diameter round iron would readily suffice to do the holding, and with less expenditure of electri- cal power than you have proposed, but if the lifting is to be across an air gap, we would need to have the conditions stated in a definite manner. CONVERTING A MOTOR INTO A GENE- RATOR (31) A. R., New York City, asks: Q. 1—What would be the proper winding for a Diehl 1/7 h.p. motor to change it into a 6-volt generator for charging storage cells? Field bore is 25/16 inches, diameter of arma- ture 2% inches, length 134 inches, with 16 slots and 16 commutator segments. Its pres- ent winding yields a speed of 2800 rev. when operating as a 220-volt circuit. A. 1—To give 8 or 9 volts on open circuit, or 7.5 volts when desired for charging the cells, you will require about 12 wires per slot, or 6 per coil. This number will permit a reduction of speed from that stated; as for a low voltage generator, necessarily requiring copper brushes, the speed should be kept as low as possible. As you did not specify the size of slots, we cannot decide what is the largest permissible size, but you can readily determine that for yourself. Field wire should be about 25 times as large as at present, which, in the B. & S. wire gauge, means a number about half as large. For instance, if present wire is No. 30, you can substitute No. 16. Q. 2.—What size of water motor to use, if operated at city pressure? A. 2.—As you do not state the pressure in pounds we cannot decide. You may be in the basement or the attic, and the difference in pressure will be considerable. In any case, you will find operation from such a source very expensive. RECEIVING SET CONNECTIONS (32) W. W., Whiting, Ind., asks: Q. 1—What is the best connection for the following instruments? Receiving trans- former, detector, loading coil, variable con- denser, fixed condenser, 2000 ohm head set. My aerial is 50 feet long. A. 1—Connect the aerial to the loading coil, from the loading coil to the primary of the receiving transformer, and from the re- ceiving transformer to the ground. This is known as the primary circuit. If the loading coil is not already provided with a switch for

Page 130

526 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE cutting it out when not in use some form of switch must be added. Use a two point switch. Connect the aerial to the handle, or middle contact, then from one contact go to the loading coil and from the other contact go to the receiving transformer. The open end of the loading coil also goes to the re- ceiving transformer. This method actually cuts out the loading coil when not in use and does not merely short circuit it the way that is so often incorrectly done. Connect the variable condenser directly across the secondary of the receiving trans- former. From one side of the variable con- denser go to the detector, from the detector to the fixed condenser, and from the fixed condenser back to the other side of the vari- able condenser. The phones go directly across the fixed condenser. This circuit, made up of the secondary of the receiving transformer, the two condensers, the detector, and ’phones, is known as the secondary oscillation circuit. SPARK COILS (33) W. B., Fredericktown, Ohio, asks: Q. 1—Is there any way that I can connect up a l-inch, 1%4-inch, and a %4-inch spark coil so as to get a 3-inch spark? A. 1—No. Q. 2—Will a gravity battery light a minia- ture lamp? A. 2.—Because of its high internal resist- ance a gravity battery is not suitable for light- ing lamps. Q. 3—How many leyden jars should be used in connection with a 3-inch coil? A. 3—This would depend entirely on the size of the jars, and for what purpose the coil was being used. For general work something in the order of four jars would probably be used. This assumes two quart jars. Q. 4—Does the capacity of a leyden jar depend on its size? A. 4—Most certainly. The capacity in- creases directly with the surface area coated with foil. Q. 5.—Can copper plates be used in making a variable rotary condenser? A. 5.—Yes, but it is not as satisfactory as aluminum plates because copper is not as rigid as aluminum. Q. 6.—Under what conditions can I use a helix with a 3-inch spark coil? A. 6—If you can get a sharp wave with it. But it is next to impossible to obtain a sharp wave with a helix. If no other station is within range of your station you can use a helix as long as this condition exists. WINDING FOR A LOW-VOLTAGE DY- NAMO (34) E. B. K,, Portland, Ore., asks: Q. 1—What should be the winding of a dynamo to give 10 volts when driven at a speed of 2500? Dimensions are as follows: Rectangular cast iron field, 2.5 inches wide, ¥% inch thick; two poles with winding space 134 inch diameter and 1% inch long, bore be- ing 2% inches; armature has 12 round holes, each 7/16 inch in diameter. A. 1—We urge enquirers always to send a sketch of a proposed dynamo, the designa- tions in words frequently being vague. For instance, a “rectangular” field magnet may have several shapes; we will take it to be “iron-clad,” having iron both above and below armature, and the two poles having a com- mon axis. An important designation, the diameter of armature, you omitted. We will assume air gap is not over 1/16 inch on each side of armature. With these suppositions, the field ought to supply 100,000 useful lines of force, and at the speed you give, allowing for various losses, 32 conductors per slot should suffice, and you ought to get in this number using No. 17 double cotton covered wire. In- stead of using a 6-segment commutator you ought rather to have a 12, and still better a 24, else there will be considerable sparking. Of course the six will be tolerable, but not good. For shunt field you can use about 2 Ibs. per spool of single cotton covered No. 20 wire. DIMENSIONS OF 110-VOLT GENERA- TOR (35) H. S., Athens, Ohio, asks: Q. 1. Are the following dimensions proper for a 110-volt 9-ampere dynamo: Cast iron yoke 16 inches outside diameter, section 6 inches by 1 inch; four poles cast integral with yoke, each having a section 34 inches by 3 inches, 334 inches long, to be bored out 6% inches. Armature 6 inches in diameter, 3 inches long, with 24 round holes, each % inch diameter, commutator with 24 segments. A. 1—While the proportions are fairly good you have underestimated the output of the machine. Assuming a speed of 1500 r. p. m, you require about 48 wires per slot, and with due allowance for insulation you ought to get them in if you use No. 17 d.c.c. This size is good for 4 to 5 amperes, and since the winding gives the effect of four wires in parallel, you will be able to get 16 to 20 amperes iu al!. Sparking will be reduced if you use a 48-segment commutator, winding two coils per slot, that is, after every 12 turns bring out a lead to the commutator. The .entire length of the pole pieces as you have sketched them will not be available for wire, and the appearance will be greatly improved by filling in the pattern with a flat pad for each coil to rest upon. Use 6 lbs. per spool of No. 21 s. c. c. wire. You can still further improve the appearance and operation of the machine if you follow the design for one of almost these dimensions made by our Mr. Watson, in the electrical engineering labora- tory of Brown University. Separable pole pieces are used, liberal self-oiling bearings, etc. If interested, we will be glad to advise your further.

Page 131

ae RADIO SECTION Devoted to the Encouragement of Amateurs and Experimenters in the Field of Radio Communication Wireless in the Dark Continent By M. E. Pelgrims IRELESS is rapidly invading the most remote corners of the earth. In the French colonies of Central Africa, near Lake Tchad, seven wireless stations are in daily use, operated by the French government. In 1911 it was decided by the French Minister of Colonies, M. Messiny, to connect the military terri- tory of Tchad with chief of the radio service of Madagascar, a lieutenant and twenty-five men of the signal corps, were disembarked on the African coast and had to start on their difficult journey through the tropical for- ests. All of the apparatus had to be carried on men’s backs for hundreds of miles. Later on in the journey, oxen and canoes were used Ouadai. As it was impossible to run wire lines between — because of the dense vegetation, the wild animals, the high cost of the miles of wire required and, most important of all, incessant wars SA FH. AAA Bork0o » Foya VBigrerac \ the two territories |j* Co Mussoro ° Abeshr Kort Lamy ie 177 . ES on land and water to carry the mate- rials and apparatus. The party had to be divided into two separate parties, VA one going by way of Lagos (Nigeria) | and Zinder, the other through “4| French Congo, with the natives, + Oubanghi and wireless was chosen - A section of Central Africa where wireless telegraphy as the most practical is depended on as the sole means of rapid communi- cation with the outside world. be means of communi- cation. It was no easy task to install the radio stations. The engineers decided to install six stations separated anywhere from 125 to 200 miles apart and scattered through- out the Tchad district. The stations were finally built at the following points: Nguigmi, Mao, Mussoro, Ati, Abeshr, Faya and Fort Lami. The first difficulties were encountered when the party, consisting of Captain Chaulard, head of the expedition, a Cap- tain of the Colonial Artillery and ex- 527 Chari. The stations to installed con- sisted of two steel masts ninety feet high, a five-horsepower kerosene motor driving an alternating current generator of one thousand cycles frequency, .o5 mfd. condensers, and mu- sical notes spark gap, and other pieces of apparatus, all of which were packed in steel waterproof boxes of about 155 pounds each. One night the tent of the party was flooded and upset, and on more than one occasion they were seri- ously annoyed by the wild animals of the jungles.

Page 132

528 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE Then came the technical troubles. The sets were first tuned to a 1,500-metre wave length but the results were very poor, only 95 miles being covered. The wave length was lengthened to 3,500 me- tres and 10 feet more added to the masts. This resulted in increasing the range to a trifle over 400 miles. At the present time the Fort Lami station communicates reg- ularly with Abeshr, a distance of about 300 miles. The constructors were also handicapped by the impossibility of se- curing a good ground connection at first. Finally, one of them conceived the idea of burying the steel boxes in which the apparatus had been packed and connect- ing the ground wire to them. This proved to be an ideal ground and the results were still more satisfactory. The conquered wilderness soon avenged itself upon’ the invaders. The men were stricken by the malarial fevers and the lieutenant and several of the men had to be sent back to France in order to save their lives. Captain Chaulard and the other engineers, however, struck to their posts and while the other men were helplessly ill, he, shaking with fever him- self, kept in constant communication with the other stations. This self-sacrifice nearly cost him his life on two occasions, but his courage inspired the other men, and some time later they succeeded in establishing the seventh station 250 miles northward, thus connecting Borkoo with Ouadi. Later on, when he was able to communicate between. Faya and Fort Lami, a distance of about 454 miles, the French government decided to award him the Legion of Honor decoration in rec- ognition of his services. In this manner has the French Signal Corps invaded into the darkest corners of Africa and established wireless sta- tions which permit of communication with the outside world. The courage and perseverance they have shown is typical of wireless men the world over. A High Tension Battery Switch for Audion a has been long acknowledged that in the telephone-grid circuit of an audion detector, adjustment of the high- tension voltage is necessary, as all bulbs do not act alike, and the same bulb is found to work different under varying conditions. In order to provide for this adjustment it has been customary to em- ploy an ordinary point switch, the lever of which is connected to one side of the circuit and the points connected to con- secutive plates of the high-tension bat- tery. Now in such an arrangement it is quite apparent that if the points are set close together or the switch lever which rides over the points made wide enough to span two consecutive points, then, if great care is not always taken to see that it is in contact with only one point at a time, the current from one cell will pass from its point across the lever to the next point, thus short-circuiting one cell and destroying its usefulness. Circuits The only method in use within the writer’s knowledge to prevent such short- circuiting of cells has been to separate the points so far and to make the switch so narrow that no bridging could pos- sibly occur. This method is, of course, quite effective, but, owing to the fact that the lever must ride down into the space between each pair of points and up over each point, this type of switch is open to the objection that it is difficult to ad- just, noisy, and, owing to the unusual distance between the points, is not as neat in appearance as might be desired. In the construction of an audion cabi- net the author was confronted with this problem and solved it very successfully in the manner about to be described with the aid of the accompanying drawings. In Fig. 1 there is given a diagram of the connections used on this switch, and there is diagrammatically shown the method employed. It will be at once

Page 133

as RAST: % é

noted that between the switch points of the ordinary switch there are interposed other points, the space between all the points being equal and but 5/16 inch when using %-inch points. These extra points are all connected together at the back of the switch panel, and take the place of the usual conducting arm and connection to the center of the same. In this case the switch arm acts only as a bridge between any two points selected.

POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 529 of the switch, this particular model em- ploying ten live points and nine common points. Fig. 3 is a side elevation of the same and shows how the common points are joined at the back of the panel by means of the brass strip, A. This strip is shown in detail in Fig. 5. The strip is cut from a piece of thin brass as shown and the little tabs bent up at right an- gles, after which the tabs are fastened

<—e-- {alalalalalalalalel

Fig. ‘a.

Fig. 3. 71g. 4.

Constructional details of a high tension switch for audion circuits, as well as the wiring scheme used in conjunction with it. Thus, connection to any cell of the high- tension battery is obtained by placing the switch arm in such a position that the point connected to that cell is connected to the adjacent point through the arm. This in brief is the method employed. It is, of course, evident that in such a switch the cell terminals can never be- come crossed and also that as the switch arm does not enter the spaces between the points that a perfectly smooth riding switch is obtained. Fig. 2 shows to scale the appearance

under the heads of the switch point screws, as clearly shown in Figs. 3 and 4. Fig. 4 is a section taken on the line of vertical centers of the switch in order to disclose the construction of the switch lever with its hard rubber handle, and also the method of attaching the lead wires to the live points. Into the kerf of the fastening screws at the back of the switch points is drilled a small hole just large enough to take the cleaned and bared end of the lead wire, which is inserted in the hole and soldered in

Page 134

530 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE with the aid of a small blow torch and suitable soldering paste. The soldering can be done before the points are fas- tened on the panel if a screw driver is first provided having a notch through the center of its edge to accommodate the wire. If, however, the rubber panel is thick and the soldering is done quickly there is no danger in soldering such leads after the switch is partly assem- bled. In order to construct this switch within reasonable limits as to space and yet give it as neat an appearance as pos- sible, it is necessary to use a type of switch point that has a hole at the rear for a machine screw. The ordinary switch points now largely used have a threaded shank and nuts at the back which take up too much space. Contributed by Cuas. Horton. A Variable Condenser of New Design There has recently been perfected by Eugene T. Turney, an inventor of New York City who has a number of wire- less inventions to his credit, a variable This variable condenser is operated by pulling or pushing the rod protruding from one end. condenser that combines a large capac- ity, compactness and ease of operation. The new condenser is not of the com- mon intersecting plate type. Instead, there are a large number of plates sepa- rated by air spaces and so mounted that they may be moved as a single unit on two brass rods. One of the brass rods is insulated from the plates by means of an insulating bushing, while the other makes contact with the plates. The plates are placed on two carrying rods with the holes in a staggered position in relation to each other, so as to make them alternate in their point of contact. The supporting rods are for part of their length made of insulating material, while the remainder is brass. As the plates are drawn over the insulated portion of the rods, more capacity is procured. When the plates are moved in the opposite direction so as to bring them on the brass portion of the rod, they are short-cir- cuited, reducing the capacity. The capacity of the condenser is de- termined by the proximity of the plates, which in turn is controlled by the thick- ness of the spacing washers between the plates. The capacity can be increased without enlarging the size of the plates, by using thinner washers between them. Owing to the peculiar construction of the instruments, the plates may be placed ex- tremely close together, thus securing a comparatively high capacity. This con- denser, made with thirty-five plates, has a capacity of .00046 mfd., while another of fifty plates spaced closer together has a capacity of approximately .oo2 mfd. Among the advantages of the new con- denser may be mentioned the fact that it is impossible for it to get out of order. The plates cannot short-circuit, and the case, being both air- and dust-proof, pre- vents dirt from hampering the efficiency of the instrument. Sliding the plates on the rods causes the latter to be clean at all times and thus insures perfect con- tact. The instrument is graduated by a scale etched in the glass casing. All electrical connections are broken when the pointer sets at zero, giving this con- denser an absolute zero. The newest and oddest use of a dry battery is the electric horsewhip. The whip is supplied with two metal rings. When these are laid against the horse a current causes a mild shock, which, the inventor claims, “will materially accel- erate the speed” without injuring the horse.

Page 135

The Non-Synchronous Rotating Gap By A. S. Blatterman, B. Sc. tober, 1912, the writer has already discussed the rotating gap, present- ing a general theory to account for its action, and proposing with the aid of one or two elementary equations an explana- tion of some of the effects of rotative speed, capacity values and voltage. It was pointed out at that time that the size of the condenser was an important item in the most effective working of the gap, and in general it appeared that the correct value was considerably less for a given transformer when a rotary gap was employed than when a plain stationary gap was used. The writer’s statement to this ef- fect was met by some criticism at that time, ik Electrician and Mechanic for Oc- TRANSFORMER breaks up the wave of voltage from the inductor or transformer into several sparks per alternation. A common form of spark gap for this purpose consists of a metal disk, rotated at high speed, which carries a number of equally spaced studs about its periphery and which re- volves between stationary electrodes. The usual arrangement of the gap and its position in the circuits is shown in Fig. I. The device differs in its operation and to some extent in its purpose from the so-called synchronous rotating gap. In the latter the disk is rotated at a par- ticular speed such that the r. p. m. mul- tiplied into the num- ber of studs on the disk is equal to the num- SPARK GAP though now its truth {0} ber of alternations per is generally admitted, | a second of the primary and it is a point in Tc L alternating wave; and fact that the most ef- 3 = 2 then the stationary fective — sets of as —— are — the type under con- ed on a‘Irame so that us Ml are now Fic. |. they can be rotated using condensers con- A simple transmitting circuit in which a ro- about the disk after siderably smaller than would ‘be necessary if stationary gaps were used. The ques- tion of sparking rate was also discussed. It appears, however, that a great deal more remains to be said concerning the factors, capacity and speed, and their effects upon power, antenna current and radiation, than was evident at the first writing. The production of smooth spark tones alone is important as well as very interesting, and it is a matter of general experience among all those who have used the non-synchronous rotary that certain motor speeds produce clearer sparks than others. Where the cycle of primary current is of low frequency, that is, 25 to 133 cy- cles, the advantages of a high spark rate with musical tone can be achieved by using for the spark gap a device which * Owing to the great length of this article it has been found necessary to run it in several instalments. The continuation of the discussion will soon appear. 5) tary gap is employed the manner of the brush-rocker on a dy- namo, and thus cause stationary and re- volving electrodes to come opposite each other for sparking at the instant when the alternating wave is passing through its maximum. Thus, one spark is ob- tained in each alternation of the voltage cycle, and it can be made to take place at the maximum value of voltage in the cycle. To secure and maintain the syn- chronous relation of spark disk to pri- mary wave, the disk is mounted on the > shaft of the generator which supplies power to the transformer. To secure the desired high spark tone the spark gap, transformer and generator are designed for a primary wave of high frequency, commonly 240 or 500 cycles, which give, respectively, spark rates of 480 or 1,000 per second. The transformer, theoreti- cally at least, is adjusted to the conden- ser so as to produce a condition of res- onance for the frequency employed. 31

Page 136

532 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE That is, if L represents the inductance of the transformer in henrys, and C the capacity of the condenser in farads, then, roughly, adjustments are made to make 2arfc= f 2ufc. In practice the adjustment is made for a condition of 15 or 20 per cent. FiG. 2. An alternaton of the current secured with a high speed, non-synchronous spark gap, indicating the instants of sparking. below resonance. Thus, if resonance is obtainable at a speed of 1,500 r. p. m., the operating speed wili be set at, say, 1,300 r. p. m. With the non-synchronous rotating gap, on the other hand, the disk is re- volved at high speed, generally without regard to the frequency of the primary wave, and instead of obtaining one spark per alternation at a constant voltage, the voltage wave is broken up into several sparks occurring at no very clearly de- An alternation of the current secured from a rotary ap when the electrodes are not spaced at the critical Ce resulting in only four sparks per alternation. fined instants during the alternation, though one particular conditon may be that shown in Fig. 2 where 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 indicate instants of spark- ing. The condition for sparking is that the instantaneous value in the wave shall be sufficient to break down the gap between stationary and moving electrodes when these come opposite each other. If, as is entirely possible, a pair of moving elec- trodes comes opposite the side electrodes at an instant when the voltage in the alternating wave is not sufficient to break down the gap or when the voltage is passing through its zero value, then the regular sequence of sparking will be bro- ken, and one, two, three or more studs may pass the stationary side electrodes before the voltage has reached a value sufficient to cause a spark. Important factors are the number of studs on the disk, the length of the spark gap between moving and stationary studs, and the size of the condenser. If the spark gap is made long by drawing the side electrodes back from the disk, then a considerable voltage will be required to produce sparking and thus only a few sparks will be obtained dur- ing an alternation. Some of the moving studs will come opposite the stationary studs without sparking, because they do come opposite at instants in the alter- nating wave when the voltage is too low to bridge the gap; and the greater the An alternation of the current secured with a rotary gap under certain conditions and when one stud is rendered inactive. number of moving studs, or the greater the rotative speed of the disk, the greater will be the number of inactive studs dur- ing the cycle. If, however, the gap is made very short, as short as is mechani- cally possible, then a very low voltage is all that is required to break down the gap, and hence the condition may exist that sparking takes place to every movy- able stud as each pair in turn is presented to the stationary electrodes. The maximum possible spark length— to take the case which is shown in Fig. 2—which can be used and still permit sparking to each stud, is that correspond- ing to the voltage at instants 1, 5, 6, 10, where now the division points 1, 2, 3, 4, etc., must be interpreted as denoting in- stants when moving and stationary studs are opposite one another in a position suitable for sparking. When the gap length is longer than this every stud will not yield a spark. ee

Page 137

When it is shorter each stud may still yield a spark. When the gap is set at the critical length every stud will yield a spark ONLY WHEN MOVING STUDS ARE PRESENTED TO STATION- ARY STUDS AT INSTANTS WHICH DIVIDE THE ALTERNATION SYM- METRICALLY: AS SERIES SHOWN IN FIG. 2. For fing; if the instants of opposite POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 533 be only four. One stud has become inac- tive. If the gap is shortened now to allow discharge at voltage 5-5’ then all studs will again yield sparks, and the shorter the gap is made the greater is the permissible displacement of instants I, 2, 3, 4, 5, etc., along the cycle. When the displacement is such that the instants 5 and 10 of the representative case coincide with instants of zero voltage in the alter- position, which will here- after be called the sparking Fic.5. position, of moving and placed along the cycle as shown in Fig. 3, then at instants 5 and 10 there is available only a potential 5-5’ (=10-10’) to break down a gap whose length is set for the potential 5-5 (10-10), see Fig. 2, and hence instead of five sparks per alternation there will 16 IN CONDENSER CIRCUIT AMPERES 200 400 600 A water resistance shunted 7 ic- across the armature of a motor stationary studs are dis for securing low speeds. nating wave ther, of course, one stud will be in- active. See Fig. 4. If the above reasoning is correct we must conclude that when the spark gap is very short there are two ways in which sparking may occur. 1. In every alternation each stud may yield a spark, in which case the sparks will follow each other at equal intervals. 800 1000 1200 1400 1600 1800 SPARK __ FREQUENCY Curves obtained with a rotary spark transmitter, plotting the current in the condenser circuit and power in watts in the primary against the spark frequency. |

Page 138

534 = SS EL POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE IN Fic. 6. 6) aL LILI VI Arrangement of the various pieces of apparatus with which the author of this article obtained the data on rotary spark gaps. 2. In every alternation each stud BUT ONE may yield a spark, in which case sparks will occur in groups, the time interval between groups being twice as great as that between sparks in a group. We must expect, also, if sparking oc- 1S) AMPERES IN CONDENSER CIRCUIT. $ 200 400 600 800 curs in either the first or second way just described, that the length of the gap must be less as the speed of the disk is increased, while at lower speeds it should be possible to use longer spark gaps. Experience has shown that these ef- 1000 1200 1400 1600 1800 SPARK FREQUENCY Curve obtained with a transmitting set using a rotary gap in conjunction with a condenser of 0.005 mf.

Page 139

AMPERES IN CONDENSER -CIRCUIT. qn & 200 400 600 800 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 535 1000 1200 1400 \600 1800 SPARK _ FREQUENCY Curve obtained with a transmitting set using a rotary gap in conjunction with a condenser of 0.01 mf. fects do exist. When the disk is rotated at high speed the spark gap must be made very short to produce anything like a smooth ‘tone; and lengthening the gap by as little as 1/64” is often found to give the spark tone a very ragged quality, ap- parently indicating that a number of studs miss spark. On the other hand, when the disk is rotated at low speed the allowable spark gap is found to be much longer. General experience has also shown that the rotative speed of the gap as well as the size of the condenser has important effects on the power and aerial current, and in order to investigate this the fol- lowing experiments were carried out. For the first experiments a small 60 cycle, 5,000 volt transformer was used. The spark gap was of a common type consisting of a disk carrying 18 studs. The motor was an a. c. series motor whose speed could be varied through a range of 500 r. p. m. to 5,000 r. p. m., the lower speeds being obtained by ad- justing a water resistance placed in shunt to the armature (see Fig. 5) ; the higher speeds were obtained by giving the brushes a considerable lead. Instantane- ous values of speed were read from a tachometer, the speed counter being found unsuitable except at the highest speeds. In this way the speed could be kept quite constant for any set of read- ings. : An adjustable glass plate condenser of maximum capacity 0.01 mf. was used. The high-frequency inductance was of copper strip wound in a flat spiral. The set-up is shown in Fig. 6. An ammeter, :, voltmeter V, and watt- meter W, were placed in the primary side of the transformer. In the high-fre- quency circuit was placed a hot-wire am- meter, A,. As the maximum range of this meter was only 8 amperes it had to be used with a shunt and calibrated for the wave length used. The calibra-

Page 140

536 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE tion was effected by sending with re- duced power and observing the reading of the meter without the shunt and then with the shunt connected. The ratio of the two readings then gives the multiply- ing value of the shunt. For observing wave length and decrement in the high- frequency circuit the wave meter induct- ance L, was loosely coupled with the condenser circuit and observations taken by means of the hot-wire milli-ammeter in the wave meter circuit. A preliminary set of readings was obtained with the speed as independent variable. See Ta- ble 1. TABLE 1 Motor Speed Spark Freq. Primary H. F. Current r.p.m. N. Watts Lamps 4 450 345 11.2 I 540 400 12.2 2600 780 510 13.4 3400 1020 590 14.9 3800 1140 610 15.2 5000 1500 630 15.9 Current in the condenser circuit and power in watts in the primary were . plotted against spark frequency. See Fig. 7. It was found that with the high- er spark rates the condenser current and power increased at a slower and slower rate toward what appeared to be a max- imum. This was interesting, and steps were at once taken to see if the curves did pass through a maximum and then fall as the motor speed was carried to very high values. The 5,000,-volt transformer was re- placed by one wound for 13,000 volts, and a new spark gap installed having twelve points, whose speed could be ac- curately controlled from 200 r. p. m. to 12,000 r. p. m. The effect of disk speed was exam- ined first. The motor speed was varied for different values of capacity in the condenser and readings taken of speed, high-frequency current, watts input to the transformer, primary voltage and pri- mary current. Table 2 and the curve Fig. 8 are for a condenser of 0.005 mf., Table 3 and the curve Fig. 9 are for 0.01 mf. and Table 4 and Fig. 10 are for a condenser of 0.02 mf. All three of these curves exhibit dis- tinct maxima of current in the high-fre- quency circuit corresponding to certain critical motor speeds. TABLE 3. C—0.01 mf. Motor Speed I Prim. Prim. r.p.m. amps. Watts. amps. Volts. 12,000 4.0 110 5:3 108 5,400 5.0 125 5.3 108 3,500 5.0 130 ae 108 2,000 5.4 140 23 108 1,220 $.5 150 5.4 108 1,000 5.6 165 5.6 108 500 5.0 175 5.8 108 TABLE 4 C—0.02 mf. Motor Speed I ' Prim. Prim. r.p.m. amps. Watts. amps. Volts. 12,000 3.0 96 53 108 6,400 4.0 115 5.4 108 4,000 4.0 115 5.4 108 2,000 4.5 124 5.4 108 1,000 4.5 135 5:5 108

Page 141

AMPERES IN CONDENSER ORCUTT. 600 200 400 600 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE 1000 OPARK FREQUENCY 537 1200 400 1600 1806 Curve obtained with a transmitting set using a rotary gap in conjunction with a condenser of 0.02 mf. DISTANCES COVERED BY PORTABLE WIRE- LESS SETS LTHOUGH there has been a great deal said about portable work, and although we see from time to time pic- tures of different types of portable out- fits, very little has been published re- garding the distance covered by the av- erage outfit. Exception is made to the army outfits for, though we hear but lit- tle regarding their work, it is known that the sets used are practicable and efficient. It is proposed to cover in this article two items regarding practical “portable work,” which will give an idea of what may be done with limited apparatus. While in each test the apparatus used was of different make than the other, both outfits were of the loose coupled pattern, galena was used as mineral, and a 2,000-ohm headset completed the equip- ment. No fixed or variable condenser was used, so the outfits consisted of a loose coupler, ‘phones and detector. On the route known as the “Mariposa Trail” to Yosemite Valley, Cal.,'a wire- less set as above set forth was carried along with the camping equipment. At about a distance of 125 miles from San Francisco, a single copper wire 100 feet

Page 142

ii i i} i il i] | i} i i eo easneanee nee eT = aA mR A SARS carn ie. oN Fane a ae cab ED eR la a TT Sagres eee 5388 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE long was run up into a pine tree to a height of 50 feet, the other end being stretched to the instrument. At night time, San Francisco, Mare Island and numerous coastwise ships were copied without trouble, despite the fact that the location was in the Sierra Nevada moun- tains, and in the worst spot possible for the reception of messages, a small valley formed by the sharp high slopes of two ranges. This will give the camper who contemplates carrying a portable wireless outfit with him an idea of what kind of work he can do under unfavorable con- ditions and small aerial. On the peak of the range, and with an aerial supported from the top of a tall tree, it would be possible to do much better work. The other test was on a single wire 100 feet long and Io feet high the entire length. The set used was one especially designed for portable work, and weighed but one pound and a half. With this aerial, Mare Island was copied a distance of 50 miles, and on a very high wave. The signals were clear and readable, the time being about 2 P. M. Those who have thought of the buzzer as a rather primitive means of sending will do well to ponder over the results of some of our ships in Asiatic waters. The buzzer was a bell of the 110-volt type minus the gong. With this as the only sending power, distances of 125 miles were covered without trouble, and it is claimed that this is no unusual range— Pau Oarb. A Research Club Formed by Wireless Amateurs There has recently been formed at Shreveport, La., a research club by the local wireless amateurs. The members of the club are directed in their activi- ties by Mr. C. D. Simmons, their in- structor, who is a thorough master of radio telegraphy. Correspondence from wireless organizations and interested in- dividuals should be addressed to Willie Antony, 1906 Laurel St., Shreveport, La. The Bronx Radio Club of New York There has recently been formed the Bronx Radio Club of New York, which has for its object the promotion of good fellowship among the amateurs of the Bronx. The club consists of eight en- thusiastic members, most of whom have stations of their own. Members who wish to broaden their knowledge on the subject are instructed by the more ad- vanced members. The present officers are as follows: President, M. Haber; vice-president, H. Berlin; secretary, L. Brodie; treasurer, A. Richter, and busi- ness manager, J. Smith. The club will be glad to communicate with other similar organizations and in- dividuals. All correspondence should be addressed to L. Brodie, 1382 Boston Road, Bronx, New York. Those wish- ing to call in person may see the presi- dent at 670 East 170th St., Bronx, New York. The Killington Radio Club At the last monthly meeting of the Killington Radio Club of Rutland, Vt., the following officers were elected: President and secretary, Raymond H. Shaw; vice-president and _ treasurer, Reginald P. Lyman; chief operator, Bruce Mills. All communications should be addressed to the secretary at 10 East Washington St., Rutland, Vt. The Gem City Radio Association The Gem City Radio Association of Dayton, Ohio, held its first meeting at the home of Frank Caswell, 21 DeKalb St., on July 17, 1915. The meeting was well attended. The association invites all those interested in wireless to join, and correspondence may be addressed to the president, Frank Caswell, at the above-mentioned address.

Page 143

The Construction of a Variometer By Charles Horton N the early days of wireless recep- tion all adjustments as to inductance, capacity and coupling were made as nearly continuous as possible. For in- stance, in the case of inductance it was accomplished by the use of sliders rid- ing over bared wire. As time passed and the degree of accuracy and other features became apparent, point contact switches began to take the place of sliders, and continuous ad- justment gave toward all rotary adjustments, since these are infinitely superior to all others. Although the variometer is by no means new, it has not come into wide- spread use among amateurs, probably owing to the difficulties involved in its construction. In order to produce a variometer of any efficiency and range it is necessary to use portions of spheres upon which to wind the coils in order to obtain the minimum of sep- aration between way to step ad- justment. Step adjust- ments served their purposes well in cases where ordinary adjustment was required, but at the present mo- ment, due to the sudden remark- able increase of receiving radits, these step ad- justments are in danger of be- coming obsolete and, no doubt, in due time all adjustments will again be contin- uous, but with this difference: ; Up-to-date continuous adjustments will not be subject to the disadvantages of the old types and, further, they will be more nearly, or actually, perfectly continuous. As a type of these continuous adjust- ment instruments, the well-known vari- ometer may be cited. This instrument, as is well known, takes the place of the widely used loading coil, to which, of course, it is superior. The rotary adjust- ment of this instrument is also a great ad- vantage over the loading coil. In addi- tion, it may here be stated that the trend in receiving instruments is distinctly, | . 539 the coils and yet allow of a com- plete half turn to one coil with- in the other. The variometer is commonly constructed so that the inside coil may move from a position within the plane of the outside coil to a position at right angles to that plane and thence to a sec- ond position again within the Fig. 1—A view of the stationary and movable spools of the variometer. plane of the out- side coil. Thus the movable coil of the vario- meter proceeds through a rotation of 180 degrees from a position of common neutralization in con- junction with the fixed coil, to a position of no mutual action and finally to a posi- tion of co-operation, thereby rendering possible a wide and continuous variation. The drawings accompanying this ar- ticle give the construction of a very fine variometer and show clearly the method used to make the spherical coil forms. The making of the latter has been the great stumbling block to successful con- struction. Fig. 1 shows the variometer assem-

Page 144

540 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE bled in the containing case, the side having been removed to show the coils. The inner coil is shown moved into an angular position relative to the outer coil. Fig. 2 represents a front view of the instrument with the front panel removed, -and with the coils turned at right an- gles to each other. There is also indi- cated the method of mounting the sta- tionary coil upon the interior of the top panel. Fig. 3 is a view of the coils mounted on the top panel of the case, looking up from the bottom. The bearing plate at the bottom of the instrument is clearly indicated, and is intended to be screwed into a recess in the base of the instru- ment in such a way as to allow sliding motion in any direction under the heads of its securing screws, thus obviating the necessity of accurate machine work in preventing the coils from touching each other. Fig. 4 is a view of the top of the in- strument, showing the scale and other details. The steps in making the variometer are illustrated in the detailed drawings as follows: Detail No. 1 shows to scale the top of the containing case which should be made of ma- hogany, oak or other suitable wood and pol- ished by the application of several coats of shellac or varnish, and finished off with pum- ice stone and water in the usual way. Detail No. 2 is the bottom of the case, which needs only to be polished at the edges, The recess shown at the bottom of this piece should be accurately made, as the bottom bearing plate rests within it. Detail No. 3 is the front and back of the case, which should, of course, be polished in the same manner as the front. Detail No. 4 shows the two sides, which complete the case. The case is assembled by means of countersunk screws, which, if they can be secured, should be of the type known as “Oval head,” the appearance of the set being materially improved since these screws are slightly rounded on top. Detail No. 5 is the support for the station- ary coil, and should be carefully made, since the position of the stationary coil is of great importance. Detail No. 6 shows the angle pieces used to support the parts (Detail No. 5) that support the stationary coil in a position at right an- gles to the top panel of the case. Care should be taken to make these pieces absolutely square. They should also be exactly alike. Both details, Nos. 5 and 6, are specified as hard rubber, but if need be the builder can use some close grained wood such as maple, mahogany or olive wood. Detail No. 7 shows the form for the inner or movable coil. The form is made of wood turned in the lathe. The coil can be made of paper, if desired, sim- ilarly to the stationary coil form to be described later. As soon as this piece is taken from the lathe it should be shellacked to prevent the entrance of moisture into the wood and the consequent distortion. Details Nos. 8, 9 and 10 show the shaft of the variometer, which is to be made in two parts which are in- sulated from each other by a hard rubber bushing. This is done in order to provide two conductors in the shaft for the connecting of the coils. The small brass bushings shown are held on the shaft in any position desired by their set-screws, and are intended to be placed snug against the inside walls of the movable coil so as to position the coil on the shaft. It is obvious that by this means the mova- ble coil can be placed so as to rotate freely within the stationary coil. The lower end of the shaft is threaded for an 8-32 nut. Detail No. 10 is the bottom bearing plate. The screws for holding this plate to the bottom of the case are Fig. 2.—Front view of the variometer with the front panel intended to fit loosely in the holes * removed and with the spools turned at right angles to each the corner of the plate to permit other. adjustment back and forth.

Page 145

Detail No. 11 is the upper bearing for the shaft, and is made of 1/16- inch brass and one piece of %4-inch square brass with a hole drilled in it. These pieces are carefully soldered together, forming a part that is in- tended to span the two pieces shown in Detail No. 5, to which it is screwed. Detail No. 13 is the regulating knob, made of hard rubber, or wood, treated with a coat of asphalt var- nish. Detail No. 14 is the spring washer, to be inserted under the knob, in order to keep the movable coil in any position desired and prevent acci- dental change in adjustment. Detail No. 15 is the stationary coil form, which is made as follows: There is first turned on the lathe, or otherwise made, a spool or bobbin of wood, as shown in Detail No. 16. The spool is given a coat of shellac and then covered across from one end piece to the other with a piece of veneer or thin metal. Next, through a hole placed conveniently, plaster of paris is poured till the space inside is full, then the form is thor- oughly dried. The plaster should be mixed with plenty of water so that it is the consis- tency of thick soup. The form should be dried for three or four days. When the plaster is perfectly dry so that it can be scraped off as a dry powder, the covering of veneer or metal is removed and the whole affair again set up in the lathe on the centers POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE o41 lili i | | | ii . ia a} | Ti | i Ih 1 i i i hl Fig. 3.—View of the coils mounted on the top panel of th>2 case, looking up from the bottom. previously used and the plaster turned dow. truly spherical and to the specified size. If a template of thin sheet metal is used to get the spherical shape this operation is made much easier. The next step is to secure a small quantity of the paper, known to the trade as “red pattern” paper, and which can be bought at almost any wholesale wrapping paper house. It should be of a thin grade. The paper is cut into strips 3% inches wide, and as long as possible. A tin template is then provided of the size and shape shown in Detail No. 17, and cut with notch, as indicated. The form shown in Detail No. 16 is now covered with a coat of parafine over the plaster, so that the paper can be released from it, and the notched pa- Fig. 4—Top view of the variometer case, showing the handle, binding posts and graduated scale. SS th | sj ““t — f (ulin pS, " AY f H per strip wound about it in spherical form with a liberal amount of hot carpenter’s glue applied with a brush. Care should be taken that the lobes of the notched strip are prevented from lapping over one another; they should lie flat and just in contact. As the winding of the strip reaches the end of one piece the entire wind- ing should be tightly wound with string or wire to cause it to assume the spherical shape of the plaster form. Then, with the string tightly secured about it, the winding should be set aside until the glue is dry. The string is then removed and a second strip, cut the same as before, is carefully butted up against the end of the first strip and the winding proceeds. It will be noted that the

Page 146

542 POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE lobes of the cut strips do not agree from one layer to another, and for that reason the glue is applied pretty liberally to make the layers uni- form. One strip at a time is put on as described until the thickness of the shell is 3/32”. After drying the ends of the form are removed and the paper shell, after having been neatly cut around its greatest diameter into two parts, is removed from the form. It may be neces- sary to heat the affair in order to loosen the shells. The shells should now be cut down to a width of 114” with a very sharp knife and holes made at their largest diameters for the shaft to pass through. The final operation is the gluing of a 4%” paper strip on the shells at each small diameter, as shown, for the purpose of providing a base for winding the wire on, and applying a coat of asphalt var- nish all over. The winding of the wire on the forms may be conveniently accomplished by mounting the shells on the plaster form without the ends on and securing the shells in true posi- tion by means of small brads forced through them into the plaster. The winding should proceed in the usual manner, beginning in the case of each shell at the narrow re- taining strip; that is to say, at the small diam- eter. Care should, of course, be taken upon the completion of the winding of one shell to take the form from the lathe and reverse it between the centers in order that the direction of winding on the two shells shall be the same. The wire should not quite fill the shells. A strip about 3/16” should be left un- wound on each shell at its greatest diameter in order to allow space for mounting. The outside coil or stationary coil should best be wound with No. 20 single cotton-covered magnet wire, preferably left dry except that the covering may be stained green if desired with an alcohol stain. Water stain should not be used. The reason that no shellac or varnish is used is on account of the great increase of distributive capacity due to this material. If a particularly fine instrument is projected, green silk-covered wire is very at- tractive. The inner coil is easily wound sim- ilar to the shells by centering in a lathe by means of a wood chuck or any other conveni- ent manner. One-half of the coil is wound to within 3/16” of the greatest diameter (which is best marked while turning). The coil is then reversed in the lathe and the other ran wound. This coil also should be left ry. The manner of assembling is as follows: HR ~“8RASS VARIOMETER DETAILS i ORK, 3% AKE-1- SPRING WASHER ProsPror 82 2 3 @! ane Brass ; re Ye MIAKRE POINTER To Suit a Tap 8-32 +4 , q i” D 4g ima qj “ | NM 7 | 7t - ms . faonr BACK ® SpeES @® P: @ + we MAKE 2 Wooo MANE -2 Wooo € | | t = HAP D PUBBERG. } €2 7 N = D = z > 3 DRILL IO 4-7 a, ORNL FOSCS S saad 4 J | Cs | €s Sane AS Scowtw MAKES uoo AKE HARORVECER . an , Mane 1 3° BRASS sae QOranes fi c iliakeae = TOD Z Baas poate of _—— [ye ge Details of the parts necessary to build the variometer, as well as the wooden spools and case.

Page 147

— @ MAKE /- PAPER Ww A ima: ie % Z eo - oO ! | 4 / Es Aa ae | Re foe kl “tA _—_— @ Came 4 Wooo rPLASTER 37 @ DIAGRAM OF CONNECTIONS Details of the winding forms and the method of making them, as well as a wiring diagram of the variometer. The pieces, Detail No. 5, are first mounted in proper position on the under side of the top of the case; Detail No. 1, and then one of the shells, Detail 15, is mounted in the circular parts by means of very small brass screws. Next, the movable coil is loosely placed into this shell and then the other shell put on and screwed to its support with the small screws, and also attached to the other shell by means of a piece of passepartout strip, which gives the neat appearance of leather. The next operation is to slip the shafts, Details 8 and 10, through both the coils and bring the ends almost together within the hard rubber tube, Detail 9. The two shafts are fastened within the tube by means of the set-screws provided. The shaft thus com- pleted will then be extending through the cover piece and out at the bottom of the coils. The next step is to make the electrical con- nections, which are within the two coils. This is done so that the path of the current will be as follows: From one of the binding posts to one of the small ends of the stationary coil (see Fig. 1), thence across that winding, and by means of a flexible lead, to the lower bearing plate, from this bearing up through the shaft, De- tail 10, by means of a second flexible lead from this shaft to one end of the movable coil, across that winding, by means of a third flexible lead to the other part of the shaft, Detail 8, thence to the unper bearing and by a fourth flexible lead to the other binding post. It is obviously not important which end of the stationary coil lead is connected to the end of the movable coil, since the coils make a complete half revolution in operation and thus are at one time in opposition and at an- other time in co-operation. All the joints should be carefully made and soldered. When the connections have been made, the case is partially assembled by screwing to the base, Detail 1, the two side pieces, Detail 4, and then screwing thereto the top piece with the two coils attached thereto; the shaft be- ing allowed to project through the hole in the base piece. Next, the bearing plate is put on the lower end of the shaft and a nut screwed on to hold it in place. A drop of solder on this nut will insure that it does not come loose. The bearing plate is then screwed to the base in such a manner that it can be forced in any direction under the heads of the screws. The upper bearing has, of course, been put on when the coils were mounted and the spring washer is now slipped over the up-

Page 148

544 per end of the shaft and the knob at the top. By means of all the adjustments provided the shaft is caused to rotate stiffly in its bearings, and by means of the two collars on the shaft inside the movable coil the latter is spaced away from the stationary coil so as to permit of free rotation. When all ad- justments have been accomplished and the connections made to the binding posts, the POPULAR SCIENCE MONTHLY AND WORLD’S ADVANCE front and back of the case may be screwed in place and the instrument is complete. Finally, the scale should be applied after the instrument has been tested to determine which is the zero inductance point. Either end of the swing may be made the zero point if the coils are carefully connected to produce the desired result. This device will undoubtedly give good satisfaction, The Central Radio Association Blue Book The Centra! Radio Association, which covers over thirty states, announces that some supplementary pages have been added to the Blue Book which they publish, in order to bring it up to date for the fall and winter season. The _ names of all the new members are being added as well as a considerable fund of interesting articles, among them con- tributions from the pen of A. Hoyt Tay- lor, Ph.D., director of the radio station of the University of North Dakota. The Blue Book of the Central Radio Association contains a list of names, ad- dresses and call letters of hundreds of amateurs, as well as complete informa- tion in regard to their station. It also includes the call letters of all the prin- cipal government and naval stations. One of the interesting features is a key to the station calls of the world. Other features are a list of authorized abbre- viations used in radio communication, as well as dozens of short cuts in general use; instructions concerning a govern- ment radio license—how and where it can be secured ; complete descriptions of the audion detector and audion ampli- fier ; information concerning the govern- ment time signals and weather reports, as well as the meaning of every code figure; the average transmitting dis- tance of different sized spark coils ; how to build an oil insulated condenser of any size up to five KW; how wireless stations are tuned, giving in detail the various steps in tuning a transmitting set in order to secure the greatest radia- tion; the proper form to use in calling a station to send a message; articles on the reception of continuous waves, the ultra-audion and the double audion, and a number of other equally interesting subjects. The price of the book is fifty cents postpaid, and a copy can be secured by addressing H. B. Williams, secretary, Central Radio Association, Chanute, Kansas. | New Uses for Radio-Telegraphy In Life Saving The application of radio-telegraphy to motor-lifeboats, inaugurated to a limited extent last year, has been an advance of great importance, not only as a factor lessening the danger to life at sea, but also as.a great aid to navigation. In dense fog or in the presence of ice, a life- boat equipped with a radio telegraph ap- paratus is sent out ahead of the steamer? and by means of the radio signals, the parent vessel is able to follow in perfect security. In many cases when a person has fallen overboard from a steamer, the officer in the small boat sent out to pick him up is unable to find him, while from the bridge or crow’s-nest of the steamer, the man struggling in the water is clearly visible. In case of an accident aboard the steamer of so serious a nature that the ship’s crew were forced to take to the lifeboats they would no longer be forced to make the feeble and inefficient efforts to attract the attention of a pass- . ing ship that are often the horror of the present-day shipwreck. A new electrical machine will scour 2,000 pans in an hour and grease them for use again. About 25,000,000 horse-power: is de- . q veloped in the explosion from one of the biggest cannon now in use.