Popular Science Monthly 1916-02: Vol 88 Iss 2

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aoe Sot eieeeneemeeace siti Siete oe . ee arr” Popular Science Monthly 239 Fourth Ave., New York Vol. 88 No. 2 February, 1916 om Annually Mining the Air Against Zeppelins By Carl Dienstbach angle anti-aircraft artillery to de- stroy Zeppelins attacking London has been repeatedly demonstrated, and it has stimulated many a scientific mind to invent some more efficient means of defense. At night the English aero- planes are at a serious disadvantage, since the glare of the ground search- lights renders it almost impossible to drop bombs on the enemy with any degree of accuracy. Instead, they fall into London, causing explosion and con- flagration. The same danger exists in firing upward against the almost invis- ible and swiftly moving Zeppelins. Joseph Steinmetz, an American in- ventor, proposes to mine the air with bomb-carrying balloons. Small hydrogen balloons, connected in pairs or groups by piano wire (weighing about ten pounds to the mile) are to be set adrift when the Zeppelins are over London. Accord- ing to the inventor, they would rise rapidly and enmesh the enemy’s aircraft. Attached to the balloon units are small hook-trigger bombs of high explosive contact and incendiary torches, which are to be drawn into the Zeppelin’s gas bag with destructive results. The method is to be further elaborated by carrying nets of very wide mesh, an idea successfully applied in submarine war- fare. In the opinion of Mr. Steinmetz, even though the chance of a Zeppelin’s fouling the balloon-connecting wires is only one in a thousand, that one chance is well worth the attempt and expense. At first blush this scheme of mining the air as a defense against Zeppelins is attractively plausible. Undoubtedly, if the atmosphere above London were ie failure of the English high- full of floating air-mines, it would not be so easy to bombard the town from aloft. \\hen it comes to making this arrangement practical, however, serious difficulties are immediately encountered. Flotation in air is not like flotation in water. A balloon left to itself invariably goes up or comes down. It is generally considered a wonderful accomplishment if a balloonist knows the aerial ocean well enough to keep his craft in regions where sun, winds and vapors do not con- tinually force it from its level, thus causing him to use up gas and ballast and shortening the trip. Over a great city, this procedure’ would be extremely hazardous. After the air has _ been thoroughly sown with mine-balloons, it may snow. Imagine the result! With a wind blowing the balloons about dur- ing a snow storm, and their bombs strik- ing roofs right and left, the inhabitants of London might prefer the attacks of the Zeppelins. Think of the conflaga- tion .these clusters of balloons might cause! The whole plan harks back to the ex- periment made in Austrian campaign against Venice in 1849. Nothing was done by halves at that time. No less than two hundred small hydrogen bal- loons, each carrying a twenty-five or thirty pound bomb, were liberated, but they refused to stay at the right level. They continued to rise until an upper current of oppcsite direction found them and returned them to the senders. Even if the mine-balloons remained over London in their allotted places, there are other factors to be considered which could very likely result in a catas- trophe. To carry the smallest bombs, 163 i i | 4

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164 balloons must be many times larger than the heaviest floating mines. range they would furnish ideal targets to a Zeppelin’s machine- guns. A Zeppelin may easily shade its lights and yet clearly illumin- ate a near object in the air. Let a good marksman with a machine- gun be stationed at each side of the front car, and before any balloon-mine could do any harm, it would be shot down and fall into a city street. The Plan Is Feasible in Water Interconnecting cables such as Mr. Steinmetz proposes, are more satis- factory in water than in the air, where they are liable to slip off upward or downward. If caught by airships below them, the bombs will be drawn together harmlessly _ be- neath the level of the hull. The chances are that the Zeppelin would gather a trailing mass of wires, empty balloons and live bombs in its wake, to be cut off for the benefit of those be- low. The steel propel- lers would cut the thin wire, and since they are as big and heavy, would hardly be damaged. It would also be easy to shape a Zeppelin so that single wire must slip off wherever it strikes the hull, simply by slanting the outlines of all pro- jections. It does not look as though the Stein- metz plan would make Zeppelin destruc- tion assured. The three dimensions of the air necessitate the use of mines in large numbers, yet the risk is propor- tionately increased. Here comes the ques- tion of the practical value of the plan. Popular Seience Monthly At short

‘tse Bigs rs a terror of the air for Zeppe- lins and, indeed, for any den- izens of the air. But is the terror not as great for the houses below?

Hooks and flaming bombs as | Sweeping a Channel for Mines HE operation of mine sweeping is one of the most dangerous and arduous of the many tasks that fall to the lot of a navy. The dan- gers of mine sweeping are great even in the North Sea and around the Brit- ish Coasts, where there is no active _ opposition. These dangers are, of course, greatly increased when the ships are con- tinually under fire, as they were in the Dardan- elles. A mine field consists of a number of mines laid together. It will most effectively block off any particular area of water. A certain number of mines are generally laid at intervals just deep enough to render them invisible to the look-out on board the mine sweep- ers. For such work shal- low draught ships are al- ways employed. Mine sweepers work generally in pairs. Each ship tows over the stern a wooden apparatus called a kite, fitted with planes which dive beneath the water. The depth to which it dives is regu- lated by the speed of the towing ship. Each of these kites is fitted with a pulley block. <A wire rope is passed from the stern of one ship through the pulley on its own kite across the water through the block on the second kite and so up to the stern of the second ship, where it is fastened. steam ahead at the same speed, the kites dive to the depth corresponding to the particular speed, and the steel rope is stretched out between them. When the rope strikes a mine, it fires it. Soth ships

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Cleaning New York’sSnow-Clogged St reets ae oe al halt br peeerstees Motor-trucks mobilized by city for snow removal dump their loads into Hudson River N Monday morning, December 13, came New York’s first heavy snow storm of the winter. When business men and wo- men started for work, the city’s transportation lines were sadly disorganized. Street cars, busses and taxi- cabs floundered through the snow and took workers to their offices, hours late. At noon, those who were hardy enough to venture out to lurich saw a novel spectacle. Great numbers of privately-owned motor-trucks were crawling through the streets laden with snow. Drawn up beside huge heaps of snow in the busiest streets were other powerful trucks, and gangs of men were speedily throwing the snow into their capacious bodies. The old-fashioned street-cleaners’ wagons with their pa- 165 With Motor- Trucks a MOE ant = One of the new motor-driven snow plows which did much to make the streets passable after the recent New York storm tient horses were in evidence, too, but they were a minor consideration. The great work was being accomplished by the motor trucks. Through the avenues came _ heavy- powered trucks with snow-plows fas- tened to their front axles. Many of these were furnished by a "buss com- pany, while others were private trucks with a special plow attachment fitted for

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166 Popular Science Monthly the emergency. These plows pushed the snow into the middle of the streets, where it was carried away by the work- ers. On Tuesday morning, nearly all of the vast quantity of snow had disap- peared from the main thoroughfares, and the fleet of motor-trucks vanished as suddenly as they had appeared. Heaps of snow still clogged the middle of many of the side streets, but the work of removing this was done as it had been in previous winters, by gangs of men working twenty-four A Gigantic Steel Bridge-Beam NE of the greatest of modern en- gineering undertakings is the con- struction of the New Quebec Bridge, which upon completion will span the St. Lawrence near Quebec on the site of the great Quebec Bridge which collapsed several years ago with a great loss of life. Work upon the foundations of the original bridge was begun in the early spring of 1910, but nearly all the work accomplished when the bridge fell hours a day, aided by horse-drawn carts. Where did the motor- trucks come from? Where had they gone when the main streets and avenues had been cleared? Dissatisfied with the slow methods of snow re- moval last winter when two or three heavy storms paralyzed the traffic of the city, Street Cleaning Com- missioner Fetherstone ar- ranged with a number of large contractors to mobil- ize a fleet of privately owned motor-trucks, suit- able for the removal of snow, whenever a storm threatened to disorganize the transportation of the city. A census was taken of the owners of trucks who were willing to furnish them when needed for this work. A large number of these power- ful vehicles were placed at the disposal of the contractors, and when the call was sent, the trucks were quickly at their appointed stations. The work done by these trucks was remarkable. The ample bodies held an average load of two and one-half times the amount of snow that could be con- tained in the largest of the old-style carts and wagons, and the snow was carried to the various disposal points in a small part of the time usually required. As a result, the snow disappeared from the important streets as if by magic. One of the largest steel beams ever used in bridge building, designed in place of the faulty members which caused the disastrous collapse of the new bridge at Quebec, before it was completed had to be practically abandoned and re- commenced from the foundations them- selves. Since the disastrous collapse was caused by weak members, the en- gineers have fitted to the new bridge some of the largest steel beams ever used in bridge building. An idea of their great size may be gained from the illustration} showing an end section of one of the members. Half of the pin hole shown is to receive a steel pin nearly four feet in diameter. It is expected that trains will be crossing the bridge in another twelve months. ae

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ane Popular Science Monthly A Windmill Which Always Turns in the Same Direction HEN the wind strikes a surface inclined at an angle to the direc- tion of the wind, the surface is displaced in a direction that depends upon the de- gree of inclination. Upon this well- known principle sailboats, windmills, and aeroplanes are built. When the wind comes in an opposite direction— that is to say, strikes the surface on the other side—it tends to displace it in the opposite direction. It would seem then to be impossible so to place a surface that it shall always move in the same direction no matter whence the wind comes. A French windmill maker, how- ever, has succeeded in solving the prob- lem. He makes a horizontal windmill with perpendicular vanes and axis re- volved by the planes without gearing. The vanes are formed of many sheets of iron arranged in the form of a wheel. The wind on entering the wheel passes between the plates and produces motion, and the wind on issuing, dips along the general slope of the vane and produces motion in the same direction. The wind is thus utilized going and coming. \When the vanes are properly inclined, the power produced by this strange windmill is high, and the wind 167 i {|} ij A 44) i: The roll of tape is sixty feet long. On it is written one of the longest letters ever mailed for two cents Puzzling windmill which always turns in the same direction, no matter how the wind is blowing that reaches nine-tenths of the wheel’s diameter is set to work, no matter in what direction it is blowing. An Island Made to Order AWAIIAN soil is being used to build up the small coral island in the Pacific Ocean known as the Midway and used as a relay station by a trans- Pacific cable company. A quantity of earth is taken there every three months by the schooner that is sent with food supplies for the operators. The task of building the island has progressed so far that it is now possible to keep a cow on the pasture. The Longest Letter in the World OUR friends are always asking for long letters. To supply this demand a man in Los Angeles, California, has invented a little novelty that has cap- tured the fancy of visiting tourists. It consists of a roll of paper tape sixty feet long. The paper is made to write on, and has a place for the name and address of the sender and receiver. It goes as first class mail for two cents, like any other letter, and can be mailed in any mail box. These little “long letters” cause many a laugh and one can write a regular letter on the tape, by merely unrolling it as it is used up.

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Steam-Driven Models Made by a Handless Mechanic NE of the chief exhibits at the Home for Aged and Disabled Rail- road Employees of America, Highland Falls, Ill., is a collection of model steam engines made by handless Joseph J. Bel- laire. Popular Science Monthly gines, some of which are remarkable bits of machinery. Working models of steam engines predominate in his col- lections, and most of them run on steam or compressed air. The various tubes and cylinders are soldered together instead of being riveted. All the models work like clockwork. Mr. Bellaire has exhibited his models many times and has received a large number of prizes and medals. Tearing Up Rails witha Motor Truck ULLING up the half- buried track of an old railroad much in the same Way as a dentist extracts an obstinate tooth, is the novel use to which a heavy motor truck, armed with a derrick, All these miniature engines are driven by steam or air, and were made by the ‘‘handless mechanic’”’ Thirty-four years ago Mr. Bellaire, a young and healthy locomotive fireman, swung down from his cab and crawled under his engine to take the ashes from the firebox. The engineer, forgetting that his mate was beneath the wheels, received the signal from the brakeman and set his engine in motion. The un- fortunate fireman, hearing the creak of the wheels, made a_ wild was recently put in a small Ohio town. The boom of the derrick was secured by a heavy braced pillar, which acted as a pivot, to the floor of the truck. Tongs were used to clutch the rail, and the pull exerted through a steel cable and pulleys. This wrecking equipment ‘ex- tracted” between one hundred and sixty and one hundred and seventy rails per day, which is equivalent to a length of track a half-mile long. plunge for safety, and suc- faRS ceeded in freeing himseli— all but his hands. When they took him to the hospital they saved one thumb on his right hand. With infinete patience Mr. Bellaire succeeded in mak- ing his artificial hands use- ful. On his right hand is a thumb and a metal plate. On the left wrist is strapped a wooden attachment, in the center of which is a thread- ed hole for the insertion of various handy devices, the most useful of which is a steel hook. Since his accident he has spent much of the time in constructing models of en- This truck pulls upa half-mile of track during a working day

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eR Ey 2 Popular Science Monthly 169 A Motor-Cycle Converted into a Motor-Sled OW to make a power sled, is a problem that has been solved in a rough way at least, by C. H. Carpenter of Waukesha, Wis., whose great plaint in life has been that the motor-cycle he so dearly loves to tour with in summer, with his family, is not available for use in the winter, when the frost is on the pumpkin and the snow upon the ground. This motor-sled was converted from a motor- cycle at total expense of about one dollar He has solved the problem, he believes, and that with a total expense of fifty cents for a packing box and about as much for nails-and screws. An iron framework, blacksmithed to hold the motor-cycle firmly to the rest of the ma- chine, added the greatest item of cost; for with felt lined clamps to grip, yet not mar the enamel of the motor-cycle, the iron work cost the sum of two dollars. Mr. Carpenter has made a motor-sled, with a packing box, his motor-cycle, and the stout, hickory runners of an old coasting sled, cut for the purpose. Tak- ing sections of two coasting sleds, the framework of iron was so designed that the motor-cycle power wheel operated between the sleds, much as the walking beam of an old-fashioned steamboat works on the shaft of the paddle-wheels. Built upon the sled, the packing box was cut down, planed and painted. It was given a high back, and the portion cut away in front was converted into a seat. The sled makes about twelve miles an hour, the motor-cycle being equipped on the power wheel with a special gripping tire, made by the simple method of winding wire about the tire and rim. Electric Candles on a Nine-Story Birthday Cake BIG birthday cake, with thirty- five electric candles on the top, is a sight which recently astonished Colum- bus, Ohio. _The cake was made in recognition of the thirty-fifth birthday anniversay of a large store devoted to the sale of women’s goods. Heretofore it had been the custom to make use of the traditional wax candles but for obvi- ous reasons it was decided this year to make the experiment of using electric candles, which would last longer, give more light and be much more cleanly than those of wax. The result of the experiment was wholly satisfactory and electric candles will be used in the future. The wiring was buried in the sugar covering of the cake. , Apart from this novel electrical fea- ture the cake itself was very interesting because it was one of the largest ever baked in this country. It was a nine- story layer cake weighing a little short of a ton and it required the services of eight men to carry it from the motor truck which hauled it around the city into the store, where it was the center of attraction. It was four and one-half feet in diameter and into its composition there entered a barrel of flour and one thousand eggs, three tubs of butter, fifty quarts of milk, one quart of lemon flavoring, one quart of vanilla flavoring. It was covered with two hundred and twenty-five pounds of icing. This cake would supply every employee of the store with a generous portion. Thirty-five electric candles graced this one- ton birthday cake, which required eight men and a motor-truck to deliver it from the bakery

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170 Popular Science Monthly A Boy’s Street Boat CHOING the spirit of his fore- fathers who ‘crossed the bleak prairies of the west in the days of the California gold rush, when sails were occasionally raised on the prairie schoon- ers to help the horses along, a New York boy has added a leg o’ mutton sail to the foot power driving equipment of his “scooter” with the result that he has been several times in danger of breaking the speed laws of his city. With front and rear wheels oiled well, With the aid of a brisk breeze, this scooter can break the city’s speed laws and a brisk breeze blowing, he can travel at a twenty-mile-an-hour clip without much difficulty, despite the crude con- struction of his vehicle. The front wheels are those of a discarded baby carriage, while those in the rear are rollers taken from skates. The name of this conveyance is the “windmobile,” which is at least as happy as the names of apartment houses and Pullman cars. Bread Without Grain Flour HEMISTRY in Germany is strug- gling to produce a substitute for grain flour in making a palatable and grain in place of potato starch. nourishing bread. The recent potato harvest being large, most research- workers have sought to use flour from The dif- ficulty is that when bread contains an unusual proportion of potato starch, or even of rice or tapioca starch, it lacks the sponginess produced in ordinary bread through the carbonic acid devel- oped by the fermentation of yeast or by baking powder. In an article on the subject in Umschau some account is given of the experiments made to overcome the objections to the use of grain flour substituted. It had been proved that the defect in pure starch flour for bread-making is the lack of glu- ten, for the elasticity and toughness of ordinary dough are caused by the albu- men contained in gluten. A chemist named Fornet claims to have found a substance which, when mixed with dough from starch flour, produces the physical characteristics of gluten. The dough is raised with yeast, can be made from all kinds of starch, and looks like ordin- ary white bread. The bread has been found edible at the army front when several days old. The substance dis- covered is not yet announced. The fa- mous chemist, Wilhelm Ostwald, has proved that the albumen of gluten is coagulated. by heat during baking and has used egg albumen instead with or without a gas-producer, as veast or bak- ing powder, with good results, but the process is too costly. Walter Ostwald and A. Riedel have substituted thick starch pastes for the various albumens in the dough. These pastes resemble gluten in the qualities of elasticity and. impermeability to gas and are also cheap. The leaven is made of potato flour, milk, and pressed hops; baking powder can also be used. The inner friction of the starch paste produces in baking the nec- essary puffiness and porosity of the dough, and the loaf shows an elastic, porous crumb of fairly normal thick- ness. Wilhelm Ostwald also substituted casein dissolved in ammonium carbonate for gluten. In baking, the ammonia and carbonic gases present acted as leaven while the casein replaced the gluten of ordinary white flour. + seenew ,

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Enlisted Men: The Foundation of the American Navy By Josephus Daniels, Secretary of the Navy NE of the curious and unexpect- ed things which I have found since I assumed the duties of Secretary of the Navy has been the effect of a too near point of view in destroying the perspective of some of our ablest Naval Officers as to what 171 Loading a four-inch gun in battle prac- tice on the cleared deck of a torpedo boat the subordination of everything con- nected with the Navy to its military functions really means, and how far back military preparation must begin. As each new civilian Secretary of the Navy assumes office, it has of an- cient custom been regarded by the service as necessary for the Naval of- ficers with whom he comes in imme- diate contact in the Department to im- press upon him that the Navy is a fighting machine, that its sole purpose and reason for existence is to fight and fight effectively, and that everything that is done must be done with this foundation principle constantly in mind. This is an almost self-evident truth, and it would be indeed a dull mind that could not grasp it and agree, but in the carrying out of this principle there is, I find, a tendency to begin at the top, and, working down towards the foundation of things, to stop suddenly before the bottom is | scorn sopra oi ep iene CHa chan Sh ca ene aR ESTEE Se ti

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reached. Thus, in all matters of dis- cipline aboard ship. Thus, in matters of discipline aboard ship, in the training of crews and squad- rons, in maneuvers and strategy, in ar- mament and equipment, the idea of mili- tary efficiency has been splendidly car- ried out, and in these matters I hold our Navy. ranks second to none. Have Our Officers Lost Perspective? When it comes, however, to the utili- zation of our yards so that they will be of the greatest aid to the Navy as a military weapon, to the subordination of all our so-called civilian activities in the Department to the great military plan, and to the recruiting of men who will prove the most efficient military units, worthy of promotion, when fit, even to flag rank, many of our high navy officers have lost their perspective. This is all the more curious because the German military organization is continually held up by these naval officers as the ideal to be achieved, and if there is any one fea- ture where the German differs from other organizations it is in the thorough- ness with which the beginnings of things and things ordinarily thought of as par- ticularly civil are bent and subordinated from the start to their place in the final military organization. The need of perfectly trained crews so high in character and intelligence that they can grasp the most in- tricate matters of machinery and drill, that they can save tenths of seconds in the firing of a gun or keep in constant repair the most delicate electrical ma- chinery, is recognized by navy officers as highly important, but there were many, until very recently, who considered that no special effort was required to attract to the service the class of men from whom these results can be obtained. Pos- sibly this was because, in Germany, for instance, military service is compulsory, and the men with the brains and intelli- gence needed are compelled to enter some military arm of the service in any event, whereas in this country, depend- ing as we do upon voluntary enlistments, high class men cannot be secured unless there are real inducements far more at- Popular Science Monthly tractive than pretty pictures on recruit- ing billboards. It was to remedy this failure to begin at the bottom in one of the most impor- tant military matters which led me to in- augurate new ways to attract the right class of men to the service and to keep them in the service when once so attract- ed by making the term of enlistment a great opportunity to obtain, at Govern- ment expense, an education, particularly along technical lines, which would enable the man, upon his discharge, to obtain a higher wage. Opportunities for such improvement existed before I became Secretary, and, while they have been considerably enlarged since then, the only sweeping change has been to give to those enlisted men who lacked it the rudimentary school education needed before they could comprehend the mechanical and electrical trades. What I have done, however, is to bring prominently before the country on every occasion the fact that such oppor- tunities existed, and I believe there is hardly a young man anxious to improve himself who does not know that in the Navy he can find his opportunity. Our Recruits the Cream of Youth The result of this campaign has been gratifying in the extreme, and the Navy is now recruited to its full strength from so many applicants that we are able to pick the very cream, our latest figures showing that only seventeen per cent of those who apply are now accepted. In addition, while the value of a man who has already had the training of one en- listment term in the Navy is recognized as being far greater than that of a lands- man just taken on board, and while the military importance of having men of long experience on every ship has been acknowledged, the equal importance of making the service attractive to the en- listed men in order to keep them in the service has not been sufficiently consid- ered until recently. Without abating one jot of the rigid military discipline, with- out pampering or favoring the enlisted man at the risk of destroying his efficien- cy as a cog in a great machine, the num- ber of re-enlistments has increased, as the result, from fifty-four per cent to

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Popular Science Monthly 173 turing establishments as + worth time and money in increased efficiency of workmen. The young man who has mastered the fundamentals of some particular trade can enlist in the Navy and be assigned immediately to work at that trade with sure promotion ahead of him. The experience that he gets in the Navy will be far broader and greater in The daily drill on the ship’s deck is an important and interesting feature of the day’s routine. Above, sailors in a battle- ship reading-room ninety-two per cent. I am asking Congress this year for eleven thousand five hundred more men for our Navy. Thanks to the policy outlined, there is not the slightest doubt that we will be able to get eleven thousand five hundred (or more when they are needed) young men of the highest type, keen, intelligent, desirous of improving, and willing to learn their duties. It has simply been a case of willingness to learn from civil life the most efficient way to achieve a military object, for the education of apprentices has been recognized by great manufac- The navy turns out gocd stenographers and typewriters as well as good mechanics all probability than he would get work- ing at his trade outside. Take the young man who has gone in for electricity and who lives in a small town. He has few chances of learning the higher branches of his profession; wiring for electric | H | |

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174 Popular Science Monthly bells, occasionally repairing a small mo- tor, putting in electric light. fixtures— these are practically the limits of his experience. On every battleship, how- ever, are to be found the most delicate and complicated of electrical apparatus, huge dynamos of enormous horsepower, delicate signaling and recording instru- ments; every kind of electrical appara- tus is there. How to make and how to repair this apparatus is a part of his mil- itary education, progressing from the simpler work to that requiring the great- est skill, and with this training will go a thorough education in the fundamental principles of electricity as well. Every Recruit is Trained to Become a Skilled Artisan When he leaves the service he will be too proficient as an electrical expert to be in any danger of being compelled to spend the rest of his days as he began —putting up bell wires or installing elec- tric lights in a small town. He will be a welcome addition to any of the great electrical and manufacturing establish- ments, with good wages, and perhaps a place at the very top. This is true of all the other vocations, and fifty of them are taught in the Navy. There has just been established, for in- stance, a new class at Charleston for in- struction in gasoline engines, where the enlisted men will be taught not only the theory but the practical handling of the largest gasoline engines now in use. Ma- chinery of all kinds is used in these schools for enlisted men, and, in addi- tion, what is known as the yeoman branch affords an opportunity for those who desire to become expert stenogra- phers, typewriters and accountants. Here is a partial list of the schools for enlisted men at present maintained by the Navy. It is interesting as showing the wide range of subjects covered. 1. Navy aviation .school, Pensacola, Fla. 2. Electrical schools, Navy Yard, New York; Navy Yard, Mare Island. 3. Artificers’ school ; Navy Yard, Norfolk. 4. Oil burning school, Navy Yard, Philadelphia. 5. Machinist’s mates’ school and school for gas engines, Charleston, S. C. 6. Seaman gunner school and school for diving, Naval Torpedo Station, Newport, ee. B Yeoman schools, Newport, R. I., San Francisco, Cal. 8. Musicians’ school, San Francisco, Cal. Norfolk, Va. 9. Hospital training schools, - Newport, R. I., San Francisco, Cal. 10. Commissary school (for ship’s cooks, bakers and commissary stewards), San Francisco, Cal., Newport, R. I. 11. Mess attendants’ school, Norfolk, Va. 12. Naval Training Stations for apprentice seamen, Newport, R. I. Norfolk, Va. Great Lakes, IIl. San Francisco, Cal. “J How thorough the instruction is, can best be shown by the course of instruc- tion in the Navy Electrical School at the New York Navy Yard, which follows. During the first week of instruction, the recruit studies machine shop work, such as forging, welding, tempering, an- nealing, brazing and _ soldering, and thread cutting. In the second week, his machine shop instruction continues, the novice becom- ing familiar with the hand operated tools such as the lathe and lathe tools, the shaper and shaper tools, the drill press, the milling machine and mill-cut- ters, and the emery wheel. He also learns the rudiments of machine shop work, such as bench, lathe, drill press, milling machine and emery wheel work. For the third week, he studies recip- rocating steam engines, the various courses being in simple and compound reciprocating engines, also in the auxil- jaries, viz., separators, traps, pressure regulators, all kinds of valves, condens- ers, pumps, gages, revolution counters, tachometers and. indicators. Practical operation of engines and practical work also occupy much of his time. He learns assembling and dissembling engines, lining up engines, resetting and adjust- ing valves, reading indicators, overhaul- ing and repairing engine and pumps and the regrinding of valves. ; The subject of steam turbines is taught during the fourth week. The

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practical operation an d care and preservation of these complicated engines keeps the recruit busy dur- ing the week. For the fifth week, the subject is that of internal combustion engines. The study of the principles of these engines, and of special types such as the Hornsby-Akroyd, Meitz and Weiss oil engines, is

The navy offers an opportunity to study electrical engineering thoroughly pursued, and the practical operation, care and preservation of all oil engines is taught. In the sixth week, the theory of mag- netism and electricity is studied, and in the seventh week, the instructors teach the students the theory of the dynamo Bluejackets in artillery and infantry excrcises ashore. Above, a school- room on shipboard and electro-magnetism. Practical work on dynamos is ac- complished during the next two weeks, and pupils learn the mys- teries of turbo-generators, switch- boards, operating dynamos in par- allel, care of the plant and dynamo room routine. Theoretical and practical work on motors occupy the recruits’ time from the tenth to the twelfth week. Studies are made of the principles of di- rect current motors, motor generators and dynamos, and practical work is done on service motors and motor starting and controlling devices. Ammunition conveyors and _ hoists, gun elevating

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176 equipments, rammers and turret turning equipments are made the subject of study. . The thirteenth, fourteenth and fif- teenth weeks are devoted to the study of the theory and practice of lighting and interior communication. The sub- jects listed are instruments, circuits and fuses, incandescent and arc lights, tele- phones, wires and wiring, wiring appli- ances and fixtures, search lights, signal- ing apparatus, interior communication cables, switchboards, telephone circuits, telephones and fire controls. During the sixteenth and seventeenth weeks the theory and practice of pri- mary and secondary batteries are studied. The last two weeks, the eighteenth and nineteenth, are spent in a general review of the entire course, and any points that have been missed by the pu- pils are made clear in their minds. Radio Telegraphy For the first six weeks of the course in radio or wireless telegraphy, the study closely parallels the study of mag- netism and electricity, dynamos and mo- tors, alternating currents, batteries, and internal combustions which is pursued in the course just outlined. From the seventh to the nineteenth weeks, the pupil is constantly practicing at the instrument, becoming efficient at sending and receiving. He also devotes one week each to the following subjects: Condensers, inductances, oscillating cur- rents, primary circuits (transmitting), secondary circuits and closed oscillating circuits, radiating circuits, transmitting sets, receiving apparatus, receiving cir- cuits, Fessenden sets, wireless specialty companies’ sets, and Telefunken sets. The nineteenth week is spent in review, as in the other course. Immediate entrance to these schools is, of course, obtained only by those who already have some knowledge of the trade, but every enlisted man who wants to take up a trade of which he may be utterly ignorant at the time of his en- listment has only himself to blame if he does not eventually acquire a chance to obtain this special shore instruction. He has only to state to his superiors on the ship what line he would like to fol- low and provided there are not too Popular Science Monthly many already having the same desire at the time on the ship, he will be assigned duties on shipboard which will give him a certain familiarity with the subject. After a year’s service, he can make ap- plication for a special course of trainin at the school, and, if he has shown sufh- cient intelligence and progress in his work on board ship, he is certain to have his request granted. With such inducements and with a daily school on shipboard where the sub- jects to be found in every public school on shore are taught him as well, it is not surprising that, instead of a lack of men of the type desired, the Navy now finds it a difficult matter to choose from the host of applicants those best suited for the service. Judges no longer sen- tence ne’er-do-wells to the Navy as a punishment, nor are such men received, and desertions in the last three years have decreased thirty-two per cent. In this way has the doctrine of sub- ordination of everything to military ef- ficiency been carried to the very begin- ning, and we are certain of efficient crews on board our ships because we have efficient recruits to begin with. Iron Industry Gains in Germany. eee the smothering effects that the war has upon industry of all kinds, the production and manufacture of iron implements increased considerably in Germany since the opening of hostilities. During the last year of peace, 1913, the German iron industry mined approxi- mately 35,941,000 tons of domestic iron ore, from which, after exporting 2,613,- 000 tons and importing 14,019,000 tons, a total of 19,300,000 tons of crude iron was smelted. During the month of Au- gust, 1914, when the war started, the output of iron products sank to 18,310 tons daily. During 1915 this daily aver- age has increased to 33,000 tons. A large percentage of the iron being pro- duced in Germany is finding its way into war implements of various sorts. HE commission form of govern- ment is in effect in eighty-one of the two hundred and four cities in this country of over thirty thousand inhabit- ants. A LEGIT RELIED TT ’

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il tad ww we aa SS OO YF ee CS Re Fish That Travel on Land ee fat oe oie: When the tide goes out and strands*these fish in a shallow pool, they leave the water, and actually flop over land to the sea. They never get lost and travel in the wrong direction, but always take the straightest road back to deep water CIENTISTS rarely go a-fishing in sy troubled waters; Professor S. O. Mast, however, of the zoological de- partment of Johns Hopkins, is an ex- ception. The Johns Hopkins professor discovered that such fish as minnows are often found in the little temporary pools left in the sand by the tide, but rarely, if ever, after the water in such a tide is so low that the outlet is closed. When the tide is falling, these fish— fundulus majolisis, the scientific name for them—swim out, somehow knowing when the tide is about to get so low that they might be trapped in the little pools in the sand. As the tide falls, they swim in and out of such tide-pools at short intervals. Thus, these fish avoid being trapped in the pools and killed when the little collections of water dry during low tide. Professor Mast has observed that the outlets of such tiny pools may be closed while the tide rises, but if they should close while the tide is falling, the fish swim about rapidly in various directions to discover water. If they find none, they leave the water and actually flop over land to the sea. Professor Mast has seen scores and scores of these fish leave large pools and travel across sand- bars more than twelve feet wide and half a foot high. The fish nearly always leave the pools on the side towards the sea. They evidently remember the di- rection of the outlet and the direction from which they entered. Curiously enough, they never make any mistakes in “walking” on dry land, either. Professor Mast never found one to take a wrong direction for any great distance. Although he admits that it is not yet definitely known how fish are guided in the right direction, it is certain that light reflected from the water is not a factor in this sense of direction. Perhaps one of the, most interesting discoveries made by the Johns Hopkins zoologist shows how fish can make their way on dry land. Of course, locomotion on land by fish can be brought about only by successive leaps and jumps produced by rapid bend- ing and wriggling of the body or side- swiping by the tail. When trapped in a pool which rapidly dries up or evaporates, they swim about for a few minutes, then come closely to the edge of the water and swim up and down the side of the pool nearest to the sea. Finally a dense aggregation of fish forms in the outlet near the dam, and three minutes by the watch after they are shut in, they manage to climb out on the sand. They leave in groups of twelve and “march” like General Sher- man to the sea. These fish are superior to some men in finding their way home. 177 Se 5 TOOT t

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178 Popular Science Monthly Natural Cannonballs HE cannon balls illustrated are sim- ply big, nearly spherical rocks which are found at intervals in the soft sandstone of Southern California, the —a considerable distance it is believed by geologists. Lach year’s freezes and thaws throw down portions of the outer columns. Irom the vastness of the rock pile at the base of the standing columns it is evident that this process

of disintegration has been going on for many centu- ries. The posts are com- posed of basalt of great hardness and density, the product of volcanic erup- tion. Exposed portions of the top of the pile show the scratching of glaciers, yet the pile itself and the sur- rounding country is cov- ered with a layer of pumice dust, an evidence that the

Natural cannon balls found in the soft sandstone of Southern California same sand formation in which the great deposits of petroleum are found. Of course there is no oil left in these cliffs; it has all leached out and evaporated, but where the strata dip down from two thousand to three thousand feet below the surface, there it is saturated with oil and natural gas, to constitute one of the greatest oil deposits in the world. The Devil’s Post Pile HE Devil’s Post Pile is one of the greatest wonders of America. It is such a remarkable formation of volcanic rocks that it has been constituted by Presidential Proclamation “post-pile” is the product of a voleanic eruption which occurred after the glaciers had long since retreated. Fossil Plants Twenty Million Years Old KOLOGISTS deserive what is known as the Denver Basis as a great, low, swampy region (Denver is approximately its center) which existed during an early period of the earth’s his- tory when the Rocky Mountains were just pushing their way up out of the primal ocean. This great “basin” was made up of shallow lagoons and low- lying, sandy shores on which grew a rank, tropical vegetation somewhat sim-

into a National Monument. The huge pile is composed of large basaltic columns about the dimensions of tel- egraph or telephone poles, though most of them are either hexagonal or five- sided. Some, however, are four-sided and closely re- semble hewn timbers about two feet in diameter. The “posts” stand in the pile at all angles. from vertical to almost horizontal. The visible height of the tallest post is over fifty feet,

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Popular Science Monthly 179 ilar to that of the valley of the Amazon today. Huge palms, fig trees and giant ferns were laced together with a tangle. of vines, through which man, had he been on the earth at that time, would surely have found it difficult to pursue or escape from his enemies. And of the latter there would have been many. The country must have fairly swarmed with strange animal life, according to the bones of scores of species of the enor- mous, half-animal, half-reptile of the Mesozoic Era. The photograph shows the perfectly preserved leaves and stalks of this swamp growth, which was submerged in the sandy shores of some lagoon. The air having been excluded, the growth was silicified and fossilized. At a glance it resembles the intricate carving in coarse sandstone such as might have been used in some ancient decoration. This formation is placed by geologists as belonging to the Cretaceous Period which is variously estimated to have been from fifteen to twenty millions years ago. A Piece of Salt that Weighs Two Hundred Tons T the famous salt mines. of Wieliczka, eight miles southeast of Cracow, Galacia, which was the scene of bloody fighting between the Russians and the Austrians, there re- cently fell a huge mass of salt weigh- ing some two hundred tons. The great block evidently became detached from the roof of one of the chambers and came crashing to the ground. In its fall it demolished a portion of a

Perfectly formed leaves and twigs fossilized in the course of twenty million years

A two hundred ton rock of salt which recently fell into the working chamber of the greatest salt mine in Austria passage and broke down heavy timbered barriers. No one was hurt, however. These salt mines are famous not so much on account of their size and large output <s for the many wonders they contain. Indeed, they are re- garded as one of the show places of Europe. They comprise a_ sort of underground world, with all kinds of chambers, such as ballrooms, restau- rants, theatres, churches, chapels and monuments hewn out of the solid rock salt. In these chambers may be seen wonderful chandeliers carved out of the rock salt. There are sixteen sub- terranean lakes in the mines, on one of which is a boat. It lies some seven hundred feet below the surface of the earth. The aggregate length of the gal- leries at present accessible is upwards of sixty-five miles and that of mining rail- ways twenty-two miles. The mines have an annual output of no less than sixty-five thousand tons. They are the property of the Austrian government and have now been worked for upwards of a thousand years.

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Niagara on Tap By Professor Thomas H. Norton To what extent should Niagara Falls be sacrificed in the production of elec- tric power? Each year witnesses a growing bitterness between two factions: The one insists that no scenic treasure shall be permanently marred by servi- tude to the demands of commercialism; the other claims with almost relent- less logic, that in the case of Niagara, the right of the nation to utilize the enormous power available, shall not be subordinated to a mere sentiment. Professor Thomas H. Norton, in a paper which he read before the American Electrochemical Society, outlined a scheme whereby it would be possible to satisfy those who see only the beauty of Niagara, and those who see only power going to waste. The following article by Professor Norton is an abstract from the paper in question, especially revised for this issue of the PopuLaR SCIENCE MONTHLY by its author-—Fditor. HERE must be some practicable, workable thesis, according to the terms of which, on our own con- tinent for example, the rights of its in- habitants shall suffer no material diminu- tion in the opportunity to fully enjoy the splendor of Niagara, while conditions are created which permit the utilization, on a satisfactory scale, of the tremendous sovrce of power,—one of the nation’s grandest assets. The principle of an intermittcit water- fall would appear to offer a simple, but thoroughly practicable solution. It may be briefly formulated as follows: During somewhat more than half of the twenty-four hours, especially during the night time, a waterfall is completely harnessed. Every kilowatt which it is capable of creating is devoted to the service of industry. During a shorter period—from ten A. M. to eight P. M.— the cataract resumes its normal activity, contributing to the esthetic enjoyment of all who behold it. In the case of Niagara, naturally the most familiar of the world’s great catar- acts to the readers of the PopuLar Sci- ENCE MONTHLY, the application of the intermittent principle would offer no dif- ficulties of an engineering nature. The topographic factors are simple. To harness completely the great mass of descending water is a matter of comparative ease. The expense would be far less than that required for the monumental Assouan Dam of the river 180 Nile——five hundred millions. It would probably not exceed two hundred mil- lions at the outside. One-quarter of a mile above the west- ern extremity of Goat Island, where rip- ples betray the beginning of the upper rapids, a dam would be constructed at right angles to the axis of the river. The length would be about four-fifths of a mile. Niagara River at this point is ex- ceedingly shallow. Equidistant sound- ings from the American shore to the Canadian shore show an average depth of 334 feet. It is evident that the con- struction, based upon the rocky bed of the river, would be relatively easy and inexpensive. The dam would possess the necessary architectural features to harmonize with the environment. The water impounded by the closing of the gates could be led by huge canals, on both sides of the gorge, to the edge of the bluff overlook- ing Lake Ontario. From this point a multitude of penstocks and rock tunnels would conduct the entire volume of wa- ter to the level of the river near Queens- ton on the Canadian side and Lewiston on the American side, where battalions of power-houses can easily be located. The total section of the system of can- als and penstocks required for the com- plete utilization of the average flow of Niagara River would be approximately sixteen thousand square feet. The mean flow of water, with a hydrostatic head of nearly three hundred and fifteen feet,

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Popular Science Monthly - 181 “In the deep recesses behind the falling sheet of water at Niagara,’’ says Prof. Norton in his article, ‘‘a gigantic system of scaffolds would be erected. These would serve as the supports of a series of over-shot wheels or endless-chain bucket wheels. By careful disposition a considerable fraction of the available power—possibly thirty to forty per cent.—could be utilized without revealing any portion of the mechanism to the eye of the beholder” Sees

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182 Popular Science Monthly would produce about seven million, four hundred thousand horse-power. Once provided with the mechanical means to control the vast volume of wa- ter, ordinarily sweeping over the crest of Niagara, the daily program would be as follows: At 8 P. M. the entire series of gates on the dam would simultaneously close. A few minutes later and the American Falls would falter. The volume of water would swiftly diminish. Soon the grand curtain would be rent and gashed as if by invisible knives. A minute or two more, and rivulets here and there pour over the brink. The gloomy, cavernous recesses beneath the overhanging edge are revealed to the eye. Another minute, and the rivulets have changed to drops. From Goat Island to the apex of the great Horseshoe the same sequence of transformations begins. It creeps stead- ily along the crest until it reaches the Canadian shore. The deafening roar of the cataract sinks to an agonizing groan, a reproachful sigh, a dying murmur. Niagara is silent! A few minutes later and the rage and fury of the long stretch of rapids in the picturesque gorge falter and slowly sub- side. The vast volume of water between the foot of the falls and Queenston grad- ually drains away. A quiet lake remains between the railroad bridges and the base of the falls.. Its surface is about eighty- six feet below the normal level, and the enclosing cliffs gain that much in height. It would be somewhat narrower than the present river, and frequent rocky islands would appear near the temporary banks. For three-quarters of a mile the rela- tively narrow and shallow bed of the whirlpool rapids would be laid bare. The whirlpool itself would remain a some- what restricted and motionless sheet of water, forty feet below its normal level, at the head of a quiet fjord, extending inland from Lake Ontario. Such would be the topographic chang- es attending the harnessing of the catar- act. Synchronously with the vanishing of the falling tons of water, in thousands of workshops scattered over the fruitful territory of Ontario and New York, a million, perhaps many million, workmen begin their daily task. For fourteen hours the world’s greatest beehive of in- dustry is filled with the busy hum of activity, keyed to the highest pitch, ban- queting, as it were, on the corpse of a murdered Niagara! One shift of seven hours is succeeded by another of the same length. All the energy of the sev- en million, four hundred thousand horse- power is devoted to the welfare of the nation. Itis 10 A. M. As the signal is flashed from the National Observatory the gates of the great dam shoot upward. The hum of spindle and loom, the clang of the triphammer, all the many-toned ga- mut of sound which forms the orchestral accompaniment of a busy, happy people shaping, fashioning, creating the objects of convenience or luxury destined for each other’s comfort or enjoyment,—all sink to a whisper,—vanish! A minute later and the crest of a vast billow sweeps over the brink of the American Fall. In an instant, almost, with a deafening roar of exultant joy, the cataract has sprung into full activity. Swiiftly the falling curtain spreads from Goat Islend along the crest of the semi- circle, until Niagara, in full panoply of power and might, hurls her defiance at the assembled thousands gathered to wit- ness the most wondrous sight on the face of the globe—the rebirth of a cataract. The spectacle would combine all the swiftness of movement and stupendous grandeur offered by the sweep of the Johnstown flood, or the tidal wave of Galveston, free from the tragic terrors and horrors of those cataclysms. The gloomy, beetling cliffs disappear behind the sheet of foam and spray; rainbows hover in the clouds of mist; the gray walls of the gorge echo back the roar of the proud cataract! In a less dramatic and_ spectacular manner the level of water in the gorge would steadily rise; the foam and spray of the rapids become evident ; the whirl- pool resume its circling activity; and Niagara’s normal life reappear. For ten hours the thousands of ma- chines, of furnaces, of electrolytic vats rest or are available for repairs, until the sun sets, and in the twilight the hour approaches for an eager multitude to witness again the death agony of a cat- aract unequaled in size.

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Popular Science Monthly 183 A view of Niagara Falls when, a few years ago, ice dammed the river above and shut off all but a small proportion of the water. One of Prof. Norton’s plans would denude the falls each night still more than is shown here. When the water diverted by his dam to the running of his power plant, the ‘“‘grand curtain would be rent and gashed as by invisible knives, a minute or two more, and rivulets here and there would pour over the brink . . . Another minute, and the rivulets have changed to drops . Such would be the daily sequence of events. On holidays, on the Sabbath, the lovers of nature could view the falling sheet of water at all hours of day and night, in the twilight, at dawn, in the solemn quiet of midnight. When used for motive power on rail- ways, street-car lines, etc., in many branches of electrochemical industry, continuity of current is imperatively nec- essary. Storage batteries may be em- ployed, but at an increased cost for each electrical unit. It is, however, perfectly feasible to rescue a very large proportion of the power, ordinarily going to waste during the shorter period of the day, when the cataract resumes its normal activity, without affecting, to any noticeable de- gree, any elements of its scenic beauty. In the deep recesses behind the fall- ing sheet of water at Niagara, the Cave of the Winds, etc., a gigantic system of scaffolds could be erected. These would serve as the supports of a series of over- . . Niagara is silent!” shot wheels or endless chain-bucket wheels. By careful disposition a consid- erable fraction of the available power— possibly thirty to forty per cent—could be utilized and directed to electrochem- ical or transportation centers without re- vealing any portion of the mechanism to the eye of the beholder gazing at the cat- aract.. There would be a noticeable in- crease in the volume of spray, which could tend only to heighten the scenic beauty of the waterfall. The simplest means to accomplish the purpose would be a series of buckets, operating on endless belts, working on axes located immediately beneath the brink of the cataract and at the base of the falling sheet of water. Essentially an enormous overshot water wheel, with its modern effective devices on the per- iphery, distorted and elongated into the form of a belt, as used for the transmis- sion of power from one shaft to another. A complete series of such elongated wheels, closely adjusted side by side, a Ra

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184 Popular Science Monthly A Mile-a-Minute with an Air- Driven Sled would occupy the entire space behind the curtain of falling water, as far as their presence could be concealed from the view of those on the adjacent banks. It is scarcely necessary to state that during the fourteen hours of enforced quiet and rest, while the waters of the Great Lakes are diverted through a maze of penstocks, to dash upon thousands of turbines, the sight of a serried array of mechanical devices, lining the cliffs of Niagara, would be sadly out of harmony with the otherwise gloomy grandeur of the gorge. Although this period covers the time ordinarily devoted to slumber, still in the evening and during the early forenoon, tourists and others would constantly gaze upon Niagara at rest. To remedy this feature, one per cent or less of the river’s volume would be allowed to pass the dam, and flow over the Grink. It would generate a thin cur- tain of water, just enough to hide the massive scaffolding and the maze of wheels. By simple hydraulic devices, this small amount of water could be largely transformed into spray. <A deli- cate lace-like “bridal veil” would screen cliffs and every trace of commercialism. The initial outlay would scarcely ex- ceed two hundred million dollars. This is equivalent to a capital outlay of twen- ty-seven dollars per annual horsepower, based upon continuous use. The annual interest charge would be less than a dol- lar seventy-five. This approximates the rates of two dollars per annum in Ice- land and of three dollars on the west coast of Norway. At present the elec- tric power of Niagara costs twenty dol- lars per annum. It would mean the creation of an in- dustrial metropolis, surpassing any now existing on the face of the globe. No cinders or soot would pollute its atmos- phere; no towering chimneys would rise against the sky-line. Industries of the most varied nature, carbides, carborun- dum, aluminum, cynamid, chlorin, alka- lies, steel, copper, and many minor branches—all dependent upon the elec- tric current—would gravitate to this point. It would become in very truth— perhaps in name—the electropolis of America! T was doughty old Count von Zep- pelin who first pointed the way to- ward locomotion with an air propeller. More than fifteen years ago, when he first planned the giant, rigid airships which are now known by his name, he had to conduct a series of experiments in order to obtain propellers of sufficient thrust for his huge untried craft. Ac- cordingly he mounted them upon a boat and made experiments on Lake Con- stance. The speeds which he attained were not more than twelve miles an hour, but they were sufficient to prove that he could urge his first giant vessel through the air at forty miles an hour. The idea reappeared in France at a later date. Ordinary launches as well as specially constructed hydroplanes were driven on the Seine by propellers revolv- ing in air. Tissandier and Santos-Du- mont made speeds as high as fifty miles an hour on water. As in Count von Zep- pelin’s case, their experiments were prompted by the thought of obtaining a system of propulsion for air boats. So successful were they that a few motor- cycles and automobiles appeared thus propelled. Now comes an American manufactur- er who reduces the idea to commercial practice. He has constructed an air- propelled sled with which it is possible to obtain a speed of sixty miles an hour over ice or packed snow. An engineer- ing experiment, to test out the possibili- ties of an aircraft, has been developed commercially. The air-propelled ice- craft is now a vehicle of sport. Notice the construction of the sled as it is depicted on our front cover. Upon a frame supported by the two rear run- ners a gasoline engine is carried, by which the air propeller is driven. A string-piece connects the motor-carrying frame with the single forward runner. There is room for two men. The rear man does the guiding with an automo- bile steering-wheel connected with the forward runner, which is pivoted so that it acts as a kind of rudder. Stop the motor and the whole sled can be checked and brought to a standstill very quickly by a powerful emergency brake.

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Popular Science Monthly 185 A Sleeping Nest With an Electric Elevator CALIFORNIA | electrical engi- neer has constructed a_ sleeping porch thirty-eight feet above the ground. He thinks that the night air close to the ground interferes with his repose, and that the temperature forty feet from the ground is at least ten degrees cooler. His sleeping porch is a veritable nest in a steel tree. He took pains to build his cage’ to withstand the high winds that occasionally prevail in that section of California. The steel poles which sup- port the elevated bedroom are stoutly braced, and he has estimated it will be comfortably safe in winds blowing as briskly as two hundred miles an hour, thus allowing him an ample margin of protection. A miniature elevator. lifted by a di- minutive electric motor of one-sixth’ horsepower is employed in making -the flight between the ground and the lofty bed chamber. Publishing a Paper Aboard a Train ERHAPS one of the oddest publica- tions of recent years was that issued aboard a special train traveling While the editors wrote copy in the parlor cars, the newspaper was printed every day in the baggage coach The owner of this sleeping nest cannot fly to his bed, like a bird, and so he installed an electric elevator between St. Paul, Minn., and Spokane, Wash. An entire printing equipment, including a linotype machine, a large cabinet of hand type and a printing press, was installed in the baggage car. The editors were selected from managers of the touring party and did their work in the parlor cars, and the paper was printed every day in the baggage coach. The press used was the narst working mode! of a new type of machine. SS

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OMMON sense teaches everyone i that speed, range, striking power and adequate armor protcction, are essential in a fighting vessel and the ship in which these are combined to a pre-eminent degree most fully meets the ideal. But it is no easy matter to unite all these attributes in a single craft of a given tonnage. If a battleship is excessively armored, weight must be saved elsewhere—in guns, en- gines, etc. And so it happens that every fighting ship-is more or less a compro- mise effected -by the advocate of speed with the advocate of heavy guns and thick armor. Although the developments in battle- ship construction have been exceedingly rapid, the greatest ‘impetus was given about ten years ago: when Great Britain came to the fore with the Dreadnought, a ship which mounted only big guns, namely ten twelve-inch rifles. She was fast too, for her speed was twenty-one and one-half knots, something unprece- dented in battleships. Soon the superdreadnought appeared, a vessel still faster, mounting still bigger guns, and still more heavily armored. Then came the battle cruiser, a formid- able craft with a speed of twenty-eight knots—a type also first introduced by Great Britain. These battle cruisers—vessels which mount somewhat fewer heavy guns than the superdreadnought, but of the same caliber, and which have somewhat lighter armor and the greatest speed that can be given to a warship are at last to be intro- duced in our own navy. If we were to engage now ina naval war with a foreign power, we would be hopelessly at a dis- advantage, not only because of the few- ness of our superdreadnoughts, but be- cause we utterly lack battle cruisers. While no official announcement has been made of the principal features of these new ships, the PopULAR SCIENCE MONTHLY is in a position to present de- tails which may be accepted as accurate. Profiting by the lessons taught by the engagements fought off the Falkland Islands and in the North Sea, this new America’s First Thirty-Five Knot Battle-Cruiser battle cruiser of ours is to have a speed somewhere between thirty-two and thir- ty-five knots. Obviously engines of enormous power are required to attain that speed, and so we may expect that one hundred thousand horsepower must be generated. Every additional knot means an inordinate increase in engine capacity. Our unbuilt and unnamed battle cruiser will have eight fourteen-inch guns and twenty five-inch guns. At first blush it would seem as if the Queen Elizabeth's fifteen-inch guns must carry the day if these two ships were ever opposed. but our ordnance officers have made the state- ment that the new fourteen-inch guns which they have developed are the su- perior of the fifteen-inch guns at present used in the British navy—or statements to that effect. The armor protection of the new United States battle cruiser is to be twelve inches amidships and four inches at the ends. The Queen Elizabeth has thirteen and one-half inches of steel on the waterline, ten inches above that and a top layer of eight and one-quarter inches. It is here probably that we had to make our sacrifice in order to gain the engine power and, therefore, speed. ut if speed will enable our ship to pick out her own position and our guns have the greater range, the loss in armor pro- tection is more than compensated for. The Lion and Tiger are battle cruisers in the true sense of the word. Our ship will easily outdistance them. In tonnage there is not much to choose, for they displace thirty thousand tons as against the thirty-one thousand tons of our ves- sel. In armament we will be far supe- rior. The Lion and the Tiger each mount eight fourteen-inch guns which are prob- ably inferior in range to the guns of equivalent caliber on the proposed Amer- ican ship. The Tiger has twelve six- inch guns and the Lion sixteen four-inch guns; but weapons of such small char- acter play no part in a long range en- gagement and are serviceable chiefly for the repulsion of torpedo boats. 186 EM, DENRA,

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Is Mars Alive Pr By Waldemar Keempffert T was in 1877 that the Italian astronomer, Schiaperelli, detected on the planet Mars those curiously straight lines which he christened canalt and which have since been a bone of contention among astronomers. Later he also saw his “canals” double, very curiously, until] they looked like ; parallel rail- _ & way tracks— q j something Lag which has not - > been = satisfac- ey torily explain- = ed to this day. The Seven Hundred Puzzling Canals and What They Mean ception of our animal and plant life or even of our geographical and _ physical conditions. Far simpler is the task of the earthly astronomer who studies Mars. The planet is never obscured. No clouds, no veils of mist can dim the view; for the {| ‘Martian atmo- | sphere is ever ! dry, rare and Now that Mars is about to ap- proach the earth again, a number of observers, headed by Pro- fessor W. H. Pickering of Harvard, are to add their opinions to the dozens which have been delivered in past years, all without materially affecting the validity of Schiaperelli’s work. Although Mars can never approach us nearer than thirty-five million miles (which is much nearer than it will ap- proach in February), we know more about its surface markings, in some re- spects, than we know about our own Earth. If the Earth were viewed as we view Mars, the only evidence of human handiwork that we could see would be the extensive grain fields of Canada and the United States. Of natural phenom- ena we would note the melting of the Himalayan and Rocky Mountain snows and the consequent flourishing of vege- tation; the great caps of snow that cover the poles; the continents and oceans; and the clouds that girdle the Earth. If a Martian were asked to fathom the mystery of a planet of which he knew only these things, we would hardly ex- pect him to form a very accurate con- E. C. Slipher, of Doctor Lowell’s staff, took this instru- ment with him to South America. The drawings of the “canals” made by Mr. Slipher with this instrument agreed in detail with those made at Flagstaff, Arizona 188 severe, except around the melting caps. A weather prophet would have nothing to do on Mars. There is no weather—only the changes of the seasons. Watching the Snows of Mars Soon after the telescope was invented and used for astronomical observation it was discovered that there is snow on Mars. During each Martian winter great white caps settle down on the poles; during each spring and summer they dwindle and disappear. In the dead of winter these white expanses may measure thirty-three hundred miles in extent. Besides the snow, astronomers long ago discovered that there are curious blue-green and russet areas on the plan- et. At a time when astronomy was not as advanced as it is now, the blue-green areas were supposed to be seas and the russet expanses continents, with the re- sult that both were christened with pic- turesque but inapt names drawn from classical mythology. Some years after Schiaperelli discov- ered the famous canals of Mars, Pro-

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Popular Science Monthly fessor Percival Lowell established at Flagstaff, Arizona, an_ observatory, equipped with the best instruments ob- tainable for the special study of Mars. He has gathered about him a corps of observers, who have become wonderfully skilled in refined Martian observation; he has the advantage of viewing the planet in an atmosphere unsurpassed for clearness; he has made ‘his observatory the fountain-head of all important Mar- tian discoveries. To him we owe our re- markably detailed knowledge of the planet’s sur- 189 markings of Mars in the way that seemed most natural and simple to him. It is certain that they accept without question the markings of other planets, plotted under the same conditions. The significance of the canals is ap- parent when it is considered that no- where on Mars is there any water ex- cept at the poles. Ages older than the earth, Mars has arrived at a pitiful con- dition which may best be described as deadly aridity. Long ago much of the fertile area of the planet shriveled to face mark- ings. The Seven Hundred Canals— ‘ What Are They? It was Pro- fessor Lowell who not only confirmed Schiaperelli’s discoveries of the canals, but who plot- ted them ac- curately year after year and added to them until now their an immense desert. Oceans, seas, and lakes leaked into the interior by way of caverns and crevices, leaving. only . parched ba- sins. The at- mospher- ic gases have in part float- ed away, so that the air has become as rare and as thin as we should expect to find it miles above number is seven hun- dred and eighty - eight. It is he who originated and for more than twenty years has de- veloped the theory that the canals are all that their name implies-—artificial waterways con- structed by intelligent beings. Per- haps it is because he has so persistently heaped one piece of evidence upon an- other to prove his theories that there is any Mars controversy at all. His op- ponents would probably be more in- clined to accept the existence of the canals if he had not interpreted the The distinguishing surface features of Mars are the snow caps at the poles, vast russet,areas and blue-green regions between the poles, and the fine, straight lines which are known as ‘“‘canals.”’ .the straight lines are indeed ‘‘canals,’”? and serve to conduct the water from the melting snows at the poles to the russet-brown areas, which are deserts, and cause them to flourish. Dr. Lowell’s theory finds confirma- ’ tion in the fact that portions of the russet-brown areas assume the characteristic blue-green hue of vegetation with the advent of Spring the Rocky Mountains. Whatever wa- ter still re- mains, gath- ers in the form of snow or hoar frost at the poles. Clearly, if Mars is inhabited, Professor Lowell ar- gues, the one supreme task that engages the attention of every thinking being on the planet is the utilization of that pa- thetically scant supply of water. If it were possible to conduct the water of the melting snows in spring to those portions of the torrid and temperate zones that would still bring forth, if properly nour- ished, a race might save itseif. Dr. Lowell holds that >

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190 In the canals Professor Lowell sees the life-lines of the planet. They are to him great irrigating trenches which con- The relative sizes of the moon and of direct Mars photographs are shown by these two circles. The size of the moon to the naked eye is indicated by the circle to the left; the circle to the right indicates the size of a direct Mars photograph before enlarge- ment. This disposes of the usual conten- tion that the Mars photographs made at Flagstaff are no larger than pinheads duct the water of the melting snows to fertile fields thousands of miles away. The Canals Are Irrigating Ditches No more forcible argument in favor of this view can be advanced than their appearance and ar- rangement. Nature never works with mathematical preci- sion. Yet the canals have been planned with mathematical fore- sight. No whim governed the choice of their direction. Inva- riably they terminate in large well-defined spots, from which they radiate like spokes from the hub of a wheel. If there were one spot, or even two spots, to which a pair of lines converge, we might look on the phenome- non as one of the natural fea- tures of the planet. But when more than a dozen lines run with geometrical directness to a sin- gle spot, and, when, moreover, the spots themselves are connect- ed by lines and are in no sense isolated, we must assume that an intelligence has been at work. Aptly enough the spots and lines are distributed in the very regions where we should expect a Martian engineer to place them; in other words just where Popular Science Monthly water is needed. Were it not for their staggering length (fifteen hundred to four thousand miles), we should never see the canals at all. Viewed from a dis- tance of more than thirty-five million miles even so large a city as Chicago or London would be no largér than the head of a pin. What we see is not really a waterway, but, as Dr. Pickering and Dr, Lowell has pointed out, the vegetation that fringes its banks. Curiously enough, the canals disappear at intervals, only to reappear with their old clearness. On the face of it this would seem in itself an unanswerable refutation to any theory which assumes that the canals are irrigating ditches. It would be absurd for a hypothetical race of Martians to dig canals periodically, only to fill them again. But Dr. Lowell explains the disappearance very simply. What we see is but the sea- sonal growth of the vegeta- tion along the banks. Time is required for the water of the polar seas to make Size of Moon to naked eye The relative visible sizes of the moon and Mars. In the small circle is a photograph of the moon (the size which it appears to the naked eye). In the large circle, is a drawing of Mars exactly the size which it appears through the telescope with a power of 392 diameters—the lowest used

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Popular Science Monthly 191 itself felt; weeks must elapse before sufficiently Juxuri- ant vegetation has sprung into being so that the courses of the canals can pe traced each spring and sum - mer. And the pe- culiar manner in which the canals seem to creep down from the poles at the rate of two and a half miles an hour lends color to the explanation. The Growth and Death of Vegetation on Mars This elaborate network of sluices divides the planets into plains of more or less geometrical shape. Blue, green Martian irrigation, is demonstrated by the scientific pre- cision with which the canals have been drawn to meet them. Not a soli- tary spot is any- where to be found. Three, four, six, even seventeen ca- nals concentrate their floods on a single spot. In di- ameter the spots range from seven- ty-five to one hun- dred and fifty miles. Like the ca- nals they have been designed with ge- ometrical economy. If there are cities on Mars, it is not unlikely that they are situated in these spots. Like the canals the spots disappear and orange are the colors of these plains—colors that proclaim the char- acter of the areas Dr. Percival Lowell, who erected at Flagstaff, Arizona, the finest private ob- servatory in the world for the special study of the planets. Here for many years he has made those observations of Mars with the approach of winter; but be- fore they are ex- tinguished the ca- in question. The blue-green areas are fertile regions fed by the canals; the orange sections are deserts, hopelessly arid. This distinction Professor Lowell draws by reason of the peculiar fluctuations in hue which the blue-green patches undergo with the ad- vent of spring and winter. As autumn approaches they assume a russet tint, which renders it almost impossible to dis- tinguish them from the orange deserts. When the polar snows begin to melt they gradually deepen in shade until they as- sume the characteristic color of vegeta- tion. Inasmuch as these changes are closely linked with the waxing and wan- ing of the canals, it is evident that the one phenomenon is dependent upon the other. That the spots toward which the ca- nals converge are the objective points of which have made him the foremost au- ion ees thority on that planet in the world ~ sie oh This is_as nals have faded it should be. Be- fore our time the spots were thought to be lakes and were named accordingly. Professor Lowell regards them as oases studding the Mar- tian deserts. Lakes would never deepen in color; only vegetation can cause the characteristic fluctuations to which the spots are subject. Are the Canals Real or Merely Illusions? The amount of ink that has been spill- ed over the canals and their meaning would fill a hogshead. Many astrono- mers deny that the canals exist at all and regard them as optical illusions produced by eye-strain. But none of these skeptics has had the opportunity of studying Mars night after night in a clear atmos- phere, far from the smoke of cities. Doubting astronomers who have troubled ee aE SEE wth are Sake ciate S

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192 themselves to journey to Flagstaff or other well-situated observatories are speedily convinced that the canals are objective realities and not illusions. Un- til 1907 the Flagstaff observatory was the only one devoted to the study of planets and especially equipped and maintained for that purpose. In that year M. Jarry Deloges, at the suggestion of Flammarion, started an investigation of. Mars in France and Algeria. The result was an astonishing confirmation of the Flagstaff observations. So similar are the drawings of the Martian disk made nearly seven thousand miles apart that one set might well be taken for a copy of the other. If any evidence were needed to prove that the canals of Mars are real, it is surely found in the actual photographs which were first made ten years ago at Flagstaff by Mr. Lamp- land. of Doctor Lowell’s staff, and which have been duplicated over again by others since then. Unfortunately the detail in these pictures is so very fine that they cannot be satisfactorily reproduced in the pages of a magazine such as the PoPpuLAR SCIENCE MONTHLY. It must be admitted that it is not ev- eryone who can see the canals. The man who is a successful observer of faint stars may be quite unable to detect fine planetary detail for structural reasons. Moreover, big instruments, especially in high latitudes, are rather a hindrance than a help in observing Mars. Granting that Doctor Lowell and his followers are right and that Mars is a living world, what manner of beings are these who have dug canals to water their planet? Unfortunately, no ade- quate conception of a Martian’s physical Popular Science Monthly appearance can be formed, although Ed- mond Perrier, a French academician, ‘some years ago boldly declared that they must be very tall and very blonde. Ro- mantic guessing is not scientific deduc- tion. Doctor Lowell in one of his earlier works shows that, while we can never hope to draw a picture of a Mar- tian, we can at least deduce something about him because Mars is a small planet. The bigger the planet on which you live, the harder it is for you to move about. A steam crane would be a wel- come assistance in moving your body about on Jupiter. This is due entirely to the enormous gravitational attraction of Jupiter. The bigger the planet the hard- er are you pulled down to its surface. Mars is only one-ninth as massive as the earth. Hence you would weigh much less on Mars than you do on the earth. A Martian porter could easily carry as much as a terrestrial elephant. A Mar- tian baseball player could bat a ball a mile. Because his planet is not able to pull him down with the attractive force that the earth exerts upon us, the typical Martian has conceivably attained a stature that we would regard as gi- gantic. Three times as large as a human being, this creature has muscles twenty- seven times as effective. His trunk must be fashioned to enclose lungs capable of breathing the excessively attenuated Martian air in sufficiently large quanti- ties to sustain life. As a canal digger— assuming that he had no machinery—he would be a great success, because he could excavate a canal with the speed and efficiency of a small Panama steam shovel. 4 1 2 3 These drawings of Mars were made under different conditions by observers who knew nothing of each other’s activities. And yet the pictures agree in their essential features. Drawing No. 1 was made October 21, 1909, by E. C. Slipher, of Doctor Lowell’s staff, at Flagstaff, Arizona; drawing No. 2 was made by Jarry Desloges four thousand miles from Flagstaff on November 13, 1909; drawing No. 3 was made on January 21, 1914, with the Lowell 46-inch reflecting telescope, a magnifying power of 365 being used; drawing No. 4 made by Mr. Slipher about one hour later on the same night with the same ins- trument and the same magnifying power, shows the same important features

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A Bridge of Boats i Towing a French pontoon to its proper position—work often done under fire. The bridge is practically completed before it reaches its destination. On arrival, it is anchored and the remaining flooring is laid to connect the different. sections. (In the insert.) Cavalry shrinks from nothing—not even steep embankments. The horsemen in the picture are Russian Cossacks who are noted for their daring exploits 193 a ee

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In this War of Big Guns German artillerymen carrying a heavy 21-centimeter (8.4 inch) shell to the big gun emplacements which line the Russian front An Austrian shell bursting close to the Italian trenches. The photog- rapher who snapped this picture was buried under the earth thrown up by the explosion, and two men standing beside him were killed fs ae A pte PO el i hn Me a : ioe ha es - Huge quantities of ammunition captured from the Russians are of Japanese manufacture. Above are a large number of Japanese shells, captured from the Russians near Grodno. Below is shown a fort in which the Germans found a complete equipment of Japanese artillery 194 aad

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Curious Phases of the War ——— Filling a French " oa ae captive balloon re - 4 from cylinders of hp. 4 hydrogen gas. The : 3 invention of this form of gas con- ‘ : tainer permits of =. ° ; much more rapid 7 filling of balloons, and dispenses with the old cumbersome generating plant which was formerly used The clock of a destroyed belfry at Monfalcone, which continued to go for three hours after it fell cemeigenieeals These field kitchens in the Aisne country have been concealed in caves by their French cooks, who are preparing meals as calmly as though they were at the Cafe de Paris (At Left.) An incendiary ‘bomb which fell on a London house during a recent; Zeppelin raid

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Where the Austrians and Italians are Fighting tee “ asa / eT « fe. Flit etl fini’ asad of WM Maggiorn WCaria —_Canfin Spitse Ken Mra i] S308 8436 773% 7967 4487 . , H : : ‘ Wreee “Kish "Yohu Zueen di Boor ' Wtettagshofet + Wisch Berg ' + 630% 6842 6307 17206 Zieierkofe! + 6858 | Sobade + B754 — aatoraig Fatune, + cow. a v cei eSBs} OS 6586 re “Gers 8708 « RA } “re ' : : z ' t of ld Monta, | ; t ' Fs fa : : ' ‘1 goeGr 3 H pe ' ee ry : , ' Soe Begin ' a te ae boa ' é ’ ‘ 4 1 t : ie ty ‘ ' : ; ' ‘ H ' ir t \ ' ’ n 4 ‘ Dw ee'e Tait | 14 t ’ ! t ; Pek { * 4 Bi ; t eget g ces ek ' is ; Gail = tos ect : ig ’ Re x ‘ + 4 ; ’ feats { 1 tt Ga Tal i : eo i Ve ee a a ' owe eee : © fear t. | t > Nillech Le ae t anes 3 NO os uel) ! 4 Bes : 4 ‘ ‘ t 7 t t ; H us ee a = aa ‘ i ' ‘ Se — ge Ny HESS lect Gee Seema ‘i pean fi a ie 4 ‘ ' 4 t ' ' ‘ i i t ’ Monfalcone Sea ‘Prosecce of . Mirenere é ¥ ee Pd me. \Ag . pe . a OE, Gulf Bercole 4 Vi of Trieste } Lo . TRIESTEASE > ‘ i f u ee The Italian army, with enormous effort, and overcoming difficulties the like of which are unknown on any other front, is endeavoring to drive the Austrians from their mountain strongholds. At present the action around Goriz, or Gorizia, holds the center of the stage, for unless they capture this fort, the Italians cannot hope to take Trieste. In the illustration, the Austro-Italian border is indicated by the broad white line. The heights of the mountains are indicated in feet 196

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Austria’s Natural Citadels Austrian outposts watching the movements of Italian troops. Imagine the difficulty of storming this spot! Yet the Italians are every day attacking a seemingly impregnable mountain top. The suffering on both sides in the Alpine campaign is terrible, for the cold in the high altitudes is most penetrating, and snow-storms sweeping through the mountains cause the loss of many lives in both the contending armies 197

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War Trades Practiced at the Front An outdoor blacksmith shop among the sand dunes near Ostend (below). Most of the German troops occupying the stretch of land along the coast of Flanders are sailors from the idle fleet. Their presence at the front has released a great number of soldiers for use along other sections of the line An odd watchmaker’s shop. An Italian watch- maker who had _ been called to the colors took up his trade again when he arrived at the front. Underneath an army - wagon he set up his shop Many visitors to the trenches have brought away cigar lighters made of two cartridges. In one is placed the gasoline and wick, while the bullet of the other contains flint and a steel friction wheel

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cama autanemnemtaaeiniiniaelh Guns and Games at the Front A card game at the cannon’s mouth. These German officers are enjoying themselves while awaiting an attack upon their concealed gun emplace- ment Bulgarian artillery being set up in the field. The Bulgarians were equipped with French Creusot guns during the Balkan wars. It is quite probable that they are still using these powerful guns EAN % it 3 ' La] EE m a ’ a . : ae —— ee Zt ts ; se nce ey Cartridge belts for machine guns captured from the Russians. In spite of the tremendous losses in equipment, the Russians seem always able to secure enough to recoup their losses. The Japanese are now supplying the Czar’s forces with war material to renew the equipment lost in last summer’s retreat 199 passant

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New Labors of Hercules Building a mountain. This is not a ruined temple in Central America, but fodder stacked by Russian Prisoners for the use of German horses during the winter campaign. The Russians have gladly accepted the opportunity to work outside the war prisons -~> end Caves are now used along the whole western front for the storage of explosives. With the aid of aeroplane scouts, gunners have been remarkably successful in dropping shells upon the ammunition stores of the enemy. Hence the need for caves 200

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SEF RSE pa ons 1 E SPY SDIREREN RRM E The see PASE PILI The Fangs of the British Navy © Underwood and Underwood The first photograph ever made of one of the new British monitors in action. These craft are equipped with one fourteen or fifteen inch gun, and are very effective for coast bombard- ment. Six first-class monitors may be built at the cost of one super-dreadnaught, and are useful for coast attack as in the Dardanelles A view from the forward turrets of the super-dreadnaught ‘‘Queen Elizabeth,”’ the pride of Great Britain’s navy. The huge fifteen-inch guns shown throw a heavier shell than has ever been shot from a battleship before. During a bombardment in the Dardanelles, these great guns hurled their one-ton projectiles over a distance of nearly fifteen miles 201 See a a" —

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LE ATE LENSE 2 Ae Sar Toten a Searching for the Best Respirator and Mask

If these men come out of the gas-filled tunnel unaf- fected, the mask will perhaps be adopted. At least, it will be givena further trial. We have not heard how many of these devices have been tested in this manner and found faulty, but it is certain that many sol- diers would rather bein the trenches than in a gas-filled tunnel with an untried respirator

em

Styles in poison gas masks change more rapidly than Parisian styles in bon- nets. Officers and men are constantly searching for a more efficient mask which will enable the sol- diers to resist the thickest cloudsof asphyxiating gas. The favorite method of testing the efficiency of a new mask is to call for volunteers, who descend into a tunnel which is filled with the deadly fumes. Many volunteer to per- form this hazardous ex- periment, though the out- come is uncertain at best. They know that it may mean the saving of many lives, even if it is at the actual sacrifice of their own. More and more the war resolves itself, in its minor phases, into battles of science, and science de- mands a laboratory. Here is the laboratory of the respirators

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SS SATA ITTF J : What War Means to Ancient Art During a recent aerial attack upon Venice by the Austrians, a high explosive bomb fell upon the Church of the Scalzi and completely ruined the wonderful ceiling decoration which was renowned throughout the entire world. According to an art critic who examined the church, “Nothing but fragments of dust remain, and the loss is irreparable” 203

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Women Shouldering the Burdens of War A Serbian girl who isa pumpkin dealer. Serbia is now destitute of men in civilian occupations to a greater extent than any other of the war- ring nations A modern Delilah. Yet they say that the war is tou:hing London lightly! FL NE ES AGILE LAE SES RBM EEE IOI SB Loading bags of coal for several hours a day can be considered a good day’s work for the strongest man. Very few women would envy these Scotch women who are so valiantly taking the places of their fighting husbands 204

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% fe oe ioe 2 EEPROM SERIE APRESS An Artillery Shell Used as a Bomb a mo RP Pe OS Wei Me © Underwood and Underwood Preparing a huge 220-millimeter (8.8 inch) shell for use as an aeroplane bomb. The French have adapted some of their artillery shells so that they may be dropped from aeroplanes during their frequent raids over German territory. A percussion cap takes the place of the time fuse, and wings are placed at the large end of the projectile to keep it true to its course 205

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Underground Engineering at the Front wt “ ae A subterranean passage connecting two distant French trenches. Such is the danger of being shot by enemy sharpshooters while passing from one trench to another, that long com- municating tunnels are dug. Sappers start from both ends, and meet in the middle. The illustration shows the first connection between tunnels which have been begun a considerable distance apart, and which are about to be united 206 Rie

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4 2 i 4 ¥ i * & +] é & é ! The battery of pumps above is used to draw the water out of a flooded trench. One motor pump would draw more water and in less time, and the German army is equipped with thousands of power driven pumps. Many of these hand pumps bear American trade-marks, and much of the pip- ing was made in this country also On the right is an improvised open- air bath. A whole book could be written on the inventions of all armies for keeping clean under difficul- ties which vary with every new station, and with the ingenuity of the soldiers Water and War

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The French Helmet’s Practical Success f Ly st Hm The new field equipment of the French infantryman. The French have gone far in their efforts to substitute for their comic-opera uniforms of blue and red a practical fighting costume, and they may now be considered as well clothed as any soldiers in the field. The steel helmet is the latest addition, and met with instant favor among the fighting men. The helmet is admirably designed, and tends to prevent the multitude of head injuries which have swelled the mortality rate. The illustrations of damaged helmets show the remarkable strength of this head-gear, for in all cases shown, the soldier was only slightly wounded by missiles which would otherwise have killed him 208 AMATO =

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The Hardships and Pleasures of War Collecting copper and brass is still in vogue in Germany. The little boys of the large cities enjoy the work; they look upon it as a new sort of game. All copper and brass utensils are bought by the German government and market prices paid for the metal The Christmas spirit, strange as it may seem, was prevalent in the very trenches that are the scenes of the greatest slaughter. In many parts of the battle line foes became friends for a few hours, and after exchanging greetings and cigarettes, went back to the deadly game of killing each other. Here we have a picture of Father Christmas, a soldier, on his way to present the children of a half-ruined village with a few simple toys made by his comrades 209

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210 A Machine That Thinks Up Movie Plots EARLY every one of us believes that in the back of his brain he has a perfectly good moving picture scenario that awaits only the chance to be flashed upon the screen. He is now given an opportunity to produce, by the demand for scenarios in a field where hundreds of new stories are filmed every week. And now comes an opportunity, Rae aig Turn the handle and new words appear on the face of this machine—words that sug- gest plots for motion picture plays in the form of a plot manufacturer, for those without ideas, a compact little cardboard box that contains more plots than the moving picture people could use in a hundred years. The “movie writer” as it is called, is exceedingly simple. Arthur F. Blanch- ard, of Cambridge, Mass., who is a Har- vard graduate, is the inventor, and he believes his machine will revolutionize literary art. The device consists of a modest cardboard box six inches long, three inches wide and two inches deep. Half a dozen slots are cut in the top sur- face, beneath which revolve spools of paper upon which are printed several thousand scientifically selected words. Handles project from either side which are turned at will. The word in the top slot is an adjec- tive, that in the second a noun, the third a verb. Next comes another noun (the subsidiary character) and then follows a word expressing a denouement. Each knob is given a few twists, either selec- tively or at random, and a complete plot, Popular Science Monthly perhaps extravagantly impossible, per- haps hackneyed, or perhaps new and useful, turns up. but at all events there will be a plot. Here are a few samples; imagination must supply the details. Beautiful, stenographer, bribes, cus- toms officer, adventure, recall. Benevolent, steward, captures, press, affair, reflection. Chivalrous, stranger, dares, governess, alliance, repentanice. Cowardly, author, anguish, rejection. Bold, beggar, brawl, banishment. As a toy, the mechanical plot creator also has its uses. With each person at a dinner provided with one of the ma- chines, a story can be started by the first person, the others following in turn, each based upon the preceding one and car- rying the story. It remains to be seen how many successful picture plays re- sult from the use of this invention. em- deceives, editor, blackmails, broker, A French Motor-Tricycle Sweeper ACQUELIN, the French champion cyclist, has conceived the idea of attaching a rotary brush to the back of the motor-tricycle. His novel combina- tion attracts much attention, in operation upon the streets of Paris. To a light frame, made over steel tubes, the motor-tricycle is attached, and this frame holds the brush and is driven by a chain from the rear axle of the cycle. A basket of the proper shape lies next to the brush so as to receive the sweepings, as the work proceeds. That a professional cyclist should have in- vented this street-sweeper is natural. But why use muscle when gasoline motors are cheap?

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CD mee Se Popular Science Monthly 211 The Latest Style in Handcuffs. AWBREAKERS may be nipped in the bud most effectively by the police nippers invented by John J. Murphy of Norwich, Conn. The police nippers or “leaders,” as they are some- times called, are clasped about the wrist or even the ankles of the ar- rested man. The advantage of the new nippers is not alone in their effectiveness but also in the fact that they may be quickly and easily operated with one hand. The closing of the hand about the handle portions of the nippers causes the jaws to close. These are pivotally connected by opposed ex- tending arms with a sliding tubular member attached to the T-shaped inner handle. This tubular member slides on a basic rod to which the outer T-shaped handle is mounted. It takes but an instant to clasp the nippers on the wrist of an offender. Have You Eaten Your Cow? VERY man, woman and child in the United States eats, each year, a whole steer, sheep or hog, according to United States government figures, which show that one hundred million meatanimals are slaughtered in this country each year. Of one’s beef, mutton or pork, how- ever, one has to give up one and one- half per cent, on account of condemna- tion by government and city officials, for this proportion of the meat slaughtered is thrown out as unfit for use. The fed- eral inspection covered, last year, fifty- eight million meat animals slaughtered, and condemned 299,958 whole carcasses, and 644,688 in part. This represents considerably more than that number of cases of ptomaine poisoning which gov- ernment inspection saved Americans, but it also represents a considerable saving in other diseases. Tuberculosis was the chief disease condemned, 33,000 beeves and 66,000 pork carcasses being entirely condemned and parts of 48,000 other beeves and 440,000 other swine being removed. Hog cholera was responsible for the next largest loss, nearly 102,000 swine being condemned entirely on this account. It cost the taxpayers $3,375,000 for this protection, or four cents a head for the population of the country, which was paid for when they bought their beef, sheep or hog for the year. In selecting one’s diet for the year one should bear in mind the additional fact that over half the number of food animals inspected by the federal govern- ment last year were hogs. It will be difficult for a thief to escape the clutch of the law if these new “‘nippers” are adopted, for they can be quickly and effectively operated with one hand

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The Home Engine of Many Uses The portable gasoline engine makes possible the watering of lawns and parks where the source of water supply is a nearby lake or stream HE farmer is probably buying more gas engine horse power to- day than any other half dozen general classes. Besides being the most generous purchaser of motor cars and practically the sole buyer of tractors, he purchases the greater part of the half million ‘stationary and portable engines turned out annually by several hundred American manufacturers. Few farms are now without a gaso- line or kerosene engine—many have two, and some of only fair size have five or six, all busy. The average size of engine is increasing rapidly (now prob- ably about six horse power) and as farmers . become more familiar with them, these handy power plants are daily put to a more varied and more nearly constant use. The great majority consume gasoline. The danger of a gasoline famine, so im- minent a few years ago, has been averted for the present, at least, and the heavy- oil engine has not made much headway in the small units adapted to the farm. Farm engines, other than tractors, are almost wholly of the single-cylinder type, both vertical and horizontal being widely used. Some manufacturers make both, not only to give the farmer his choice, but to provide more than one dealer in a town with an “exclusive” agency. Most of these engines are stationary or semi-portable, i. e., mounted on skids. Many are portable (on wheels), and this is especially true of the larger sizes. The 212 usual range is from one to thirty horse power. Roughly speaking, skid-mounted engines range from one to eight horse power, and the portable from ten to thirty-five horse power or larger. The tractor has taken the place of many of the larger portable units, and is rapidly encroaching on the smaller portable field. However, there is a growing demand for the light-weight, high grade throttle governed type, so easily adaptable to many uses. * The versatility of the gasoline engine in the farmer’s hands is really remark- able. A one horse power model may play the part of a chore boy about the house, while a larger size may be at work around the barn and a still larger one be doing heavy work somewhere in the open. The washing machine, cream separa- tor, sewing machine, churn, grindstone and some of the lighter machines in the workshop call for the smallest engines. A two or three horse power engine may be the mainstay of the farm water system and run the milking machine. The electric lighting plant, plus the work just mentioned, may call for four or five horse power, whereupon the corn sheller and feed grinder are brought in to keep the power plant busy. From this point upward the character of work changes less than the size of machine for doing it. Saws, feed mills, grain elevators, hay balers, etc., may use only a few horse power or the full

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Popular Science Monthly 213 ) A traction engine of novel form at work. This machine is one of the many attempts which have been made to supply a small © traction engine which can be profitably used upon farms of moderate size. The problem of supplying such a tractor is more difficult than that of a cheap automobile Running a cream separator with a small engine. The same en- gine can be employed for other dairy work and for dozens of | other uses on the farm ' So varied is the work to be done ' upon a farm that the engine must i be readily movable from one place i to another. The photograph shows i a small engine which has been : mounted upon a truck so that it can iM be readily shifted about. It has id been geared with wheels so that it a can be attached to the mower shown, 4 which can be run by a thirteen year a old boy and faster than with horses i Above is an installation which shows how a gas engine can be used to drive a conveyor by means of which a wagon can be loaded, or hay or grain stacked and stored. At the left is an engine used to churn butter and pump water at the same time

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Popular Science Monthly Gasoline engine used for irrigating one Circular bales madeby the gasoline baler hundred and fifty acres shown on the opposite page Engine power is the most economical for running the separator, milk-testing machine, churn, mechan- ical milker and other devices of the dairy An engine- driven water power plant for the small home is one of the luxuries brought by the gasoline engine

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Popular Science Monthly 215 The engine-driven hay baler at work. It makes the bales shown on the opposite page Shelling corn by gasolene engine power Engine-driven ce- © ment mixer A typical power and water pumping plant for a large residence or institution.

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216 Popular Science

Monthly

Spraying trees in a park with the aid of an engine mounted on a horse-drawn truck

a ae ote

= <A gearless two-horsepower engine ot = which pumps from a deep well

from a traction engine was used

A drilling well at work at Amarillo, Texas. Power A twenty-two horsepower gasoline engine driving an attrition mill The picture to the left shows how a small engine can be employed to drive a conveyor and transport ice to an ice house. An engine is a very convenient thing to have whenever there is any sort of heavy hoisting to be done. Its power and ease of control make it splen- didly adaptable for such work. The same engine has many other uses on the farm

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SEARLE BEES FEARLESS EN Ao Ne BR AO TS Popular Science Monthly 217 Threshing with the aid of a portable engine. Below are two pictures which show how hay can be hauled with a motor under difficult conditions A real gasoline horse guided by reins. It can go anywhere and never gets tired os ee th | im: t H i] 1 an ‘3

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Popular Science Monthly Baling hay in the field. Below, is an arrangement for threshing and bagging peas by engine power. Contrast the horse with the engine. A horse tires out before the day is over; an engine is as fresh at night-fall as at dawn In the circle is shown a large power sprayer at work in a celery field. If the same work had to be done with hand-operated spray- ers, dozens of men would be required to take the place of this single machine To the left is a silage cutter showing a connection with gasoline engine power for cutting corn silage inside the barn during any sort of weather

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Era Popular Science Monthly 219 One engine running a grinder and pumping water at the same time. This particular outfit has many uses and has been especially de- signed to meet the requirements of the small farmer who cannot afford an expensive installation. It is illustrated on other pages at some of its tasks. Water pumping and wood sawing were the first uses to which gascline engines were put on the farm A home-made gasoline bucket dredger at work digging drains on a farm Below, an engine-driven wood sawing outfit at work Using a traction engine to uproot trees

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Popular Science Monthly

The man below is grinding mower blades with the aid of a gasoline engine. The youth who was formerly obliged to turn the handle of a grinder will wel- come this machine with joy oer

a

oe ae arn Oe atts Y <o ‘ ee oe

To the left, a five-horsepower gasoline engine mounted on an ordinary farm

A battery of sprayers is at work in the picture in the circle, spraying hops in British Colum- bia. The gasoline engine has become invaluable wherever spraying must be done over large areas -

tractor and used for almost every form of farm work

ge I IL

Driving a husker in Indiana with a portable engine is a great aid to the big western corn growers. The “hired hand” problem is brought a step nearer solution by it

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ron ere Se RING COME BETES 8 ee Popular Science Monthly Operating a well pump with a little engine To the left, an elec- tric light instal- lation for the small home. The im- provements in en- gines and electrical generators have placed electricity within the farmer’s easy reach. Good, safe illuminati@n in the farm and stable more than pays for itself in the saving of time required for various duties, to say nothing of the elimination of risk from fire, always the terror of the dweller in the country = ——— oe

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222 Popular Science Monthly capacity of an engine of twelve to eighteen horse power. The corn husker and shredder, the silo filler (especially if fitted with a “blower,” or pneumatic elevator), the big baling-press, etc., may easily utilize the power of the largest fluential organizations of technical men are working toward the standardization of power ratings and the use of stock sizes of bolts, nuts, pins and other easily obtainable parts. A farm engine is not only far more easily maintained than is commonly realized, but it is extraordinarily inexpen- sive. The horse is an ex- pensive luxury compared with a small motor. He must be fed regularly every day, whether he works or not; he is not as fresh in the afternoon as he was in the morning; he requires constant attention in order to keep him clean, to bed him properly and to minister to his_ physical wants. He may die at any moment. In fact, his work- This little engine, attached to mowers and binders, made possible the saving of thousands of bushels of grain in the West last summer. Heavy rains had made the ground soft, so that the power-driven mechanism was practically inoperative for lack of wheel-purchase. The binder was mounted on skids so that it could run Over soggy ground almost as easily as over snow. A small gasoline engine drove the binding mechanism portables which are now obtainable. Irrigation is almost a separate field, requiring a special installation, yet some of the smaller engines are pressed into service. In combination with hoists, spray pumps, balers and what-not, the utility of the gas engine becomes almost unlimited. One great drawback to the universal popularity of the gas engine is the ex- cessive competition and almost total lack of standardization — whether of price, rating, equipment, method of selling, or service to the customer after the sale. An engine advertised at a low price may turn out to be of good value, but minus cooling tank, magneto, skid base, battery box, and other desirable acces- sories, while a higher apparent price may actually prove lower because equipment of good quality has been provided in full. The tendency is toward better acces- sories, better workmanship, and better 1acilities for the furnishing of necessary repairs. Moreover, at least two in- ing life is brief. Besides there is something almost pitiful in watching a horse doing heavy work. Not one of these con- siderations applies to the in- animate, tireless, cheap en- gine. Its initial cost. is less than that of a horse; it is never fatigued. It costs nothing when it is not in opera- tion; it requires but little attention. The “hired man’ problem is not so difficult to solve when a cheap source of power is athand. A farmer wrote to an engine manufacturer and made the following interesting comparison: “A man works at the rate of about one-tenth of a horse power. That is to say, the ordinary man in one hour does one-tenth horse power of work. In a day of ten hours, he does one horse power of work. If we consider a man’s time to be worth at least $1.00 a day, it costs $1.00 to do one horse power of work by man power. A gasoline engine uses one pint of gasoline per horse power per hour. If we take gasoline at twenty cents a gallon, a pint costs two and one-half cents. The cost of one horse-power hour of work done by gas- oline engines, therefore, is two and one- half cents. The cost for man power is one dollar.” rae Feepremerr sie Ey CRPISRE ONT go SRE re

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Wwe US Cc “3 or CP VR AIRE SS TRE TS en OF MDE IIb TG apres co OR YCINRR SEE rene ee Popular Science Monthly 223 A Machine to Pull up old Telegraph Poles NE of the most difficult tasks fall- ing to the lot of the telephone or telegraph lineman is that of removing a pole which has been firm!v A Racing Car Built of Tires A CLEVERLY constructed racing car, built of tires, tubes and car- tons containing parts is shown in this photograph of a Houston, Texas, tire embedded in the ground tor a number of years. It 1s often necessary to dig the post out of its bed. A Chicago concern has recently placed on the mar- ket a jack which is said to be able to accomplish this task in a few minutes. The device is very similar to an ordinary automobile jack, but is larger and many times as powerful. In the illus- tration is shown a_ pole which was fixed five feet in the ground, and which had been embedded for eight years. It took the jack nine- teen minutes to pull the pole from the ground. A chain, with a_ grab hook attached, is fixed to the lift of the jack, and is passed once about the pole. es ee Spe The lift extends two feet; then it may be lowered and the chain given a new grip. The capacity of the jack is fifteen tons, large enough, it is claimed, to uproot the most stubborn pole. The amount of time and labor saved by this machine are worth considering. A show-window racer built of tires, tire boxes, and tire repair accessories A pole was embedded five feet in the ground. It was removed by a powerful jack in four and one-half minutes exactly dealer’s show-window. The vehicle is composed mainly of outer cases, which range in size from twenty-eight by three up to thirty-seven by four and one-half inches and are set upon a frame of light timbers. The seat is formed of cartons containing inner tubes; the dash is made of cardboard, on which are fast- ened patches and repair ma- terial tins to imitate speedom- eter and lighting systems; the exhaust is composed of a tube, stiffened within by card- board to keep it rounded. In the seat is a driver who gives the final racing touch by grip- ping the famous Barney Old- field cigar in the corner of his mouth. As yet, no one has tried to buy this car, though it will undoubtedly be sold piece by piece. ee

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When these trees were young, fence boards were nailed to their trunks. The boards are now completely buried in the tree A Tree Captures a Fence M** years ago a row of Irish poplar trees was used for the posts of a fence, and boards were nailed to the trees. The trunks of the trees, in the process of growing, gradually over- lapped the boards, until now the boards are near the center of the trunks. Not needing the fence any longer, the owner sawed off the boards, the remnants of which still protrude from the trunks of the trees. To Keep Automobiles off Railroad Tracks HE new long distance railroad signal has been brought about by the new conditions arising from the general use of the automobile. Chauf- feurs are so frequently found driving through country which is new to them that they often find themselves on the tracks of a railroad line before they know it. The long distance signal was designed to give them sufficient warning of the proximity of the rail- road tracks to enable them to be on the alert and to avoid accidents on the tracks. The new signal was designed by the officials of the Southern Pacific Railroad, and the first one was placed at the crossing of the main street in Tropico, Cal., but such excellent re- sults attended the experimental instal- lation that others are now being in- stalled. The use of the new signal will be further extended. Popular Science Monthly The lines of the sig- nal are such a departure from the typical rail- road signal that it can- not help being observed by the wayfarer, either mounted or afoot. It consists of a tube of metal eight inches in di- ameter and two and a half feet long, mounted on a support, which, in this case is a piece of three-inch pipe. The pipe also offers accom- modation for the elec- tric wires which supply the current. The tube is painted black and is mounted in the direction of the road, so that the red light inside may be seen at q a great distance before reach- ing the signal. pas iin 3: A red light inside the tube of this railway signal is visible for a great distance, and the disk attracts attention in the daytime

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Pe c,h 2 ed eT eee PERO REY T ITE IEEE Popular Science Monthly 225 It Looks Like a Telescope, but It’s Really a Camera CAMERA that can be used for taking photographs without the subject's knowledge, resembling in appearance a short tele- scope, has been brought out in Eu- This camera looks like a small telescope, but takes snapshots _ directly at right angles to the apparent line of vision of the photographer rope, in spite of the war’s absorbing inter- est. A lens almost invisible is located in the side of the tele- scope so that the photographer, point- ing what appears to ’ be a telescope at some dis- tant object, can get snapshots of objects that interest him, directly at right angles to his apparent line of vision. The lens is equipped with an adjustable shutter, so that snapshots or time exposures can be made. For tourists traveling in foreign lands, such an equipment would be of considerable value, as natives often spoil photo- graphs by unnatural posing and va- cant staring, and this little camera would throw them off their guard. In Europe they call these contrivances “detective” cameras, probably because no detective ever carried them. The accompanying illustrations show snap- shots obtained without the knowledge of those in the picture. What Is the Best Shade Tree in the United States? HE prize for the largest shade tree in the United States was won by a sycamore tree in Worthington, In- diana, which the judges of the Ameri- can Genetic Association found to have a circumference of forty-three feet, and a height of one hundred and fifty feet. This interesting incident calls attention to the fact that foresters are recom- mending the sycamore very strongly for city planting. They tell us that long experience with sycamores planted in city streets and on lawns has shown that the species is very well adapted to withstand the smoke, dust and gases sO common in cities. Besides, the sycamore is very resistant to the attacks of insects and fungi, and grows rapidly. At ten years of age, a healthy sycamore is large -enough for shade as well as for decorative purposes, Indeed, in the latter respect, it is not exceeded by any other Eastern species. Its mottled bark, its full, rounded crown, and its dense foliage, impart a very handsome and striking appearance to any lawns or boulevards which are fortunate enough to dis- play these mag- nificent trees. The sycamore ranks with the oak and hard maple as a dec- orative tree. The new camera is especially val- uable for securing natural pictures of persons who would pose and stare, or else run away, if acamera were pointed at them

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———— oa ; - SESE Perils of the Bad Road By O. R. Geyer ITHIN the last few years Iowa has been brought face to face with the- new problems of preventing the tremenduous loss of life on the state’s highways. Every state in the Union is confronted with the same problem. Failure to exercise even the most important safety first principles is costing the lives of more than one as a means of saving many lives. The majority of=*these accidents could have been prevented with the exercise of a little more care, but since the average American is in too much of a hurry to protect his own life and the lives of others, the state must help him. lowa lost seventy-five of her citizens through accidents which oc- curred on the highways of the state in the year ending November 1, 1915. The number of persons seriously in- jured was many times this, totaling about five hundred, according to the best information obtainable by the Highway Commission. Conservative estimates based on these returns from Iowa indicate that each year sees an average of from one thousand two hun- dred and fifty to two thousand persons Grade crossings and unsafe bridges constitute two of the gravest perils of the road, although the danger of unsafe bridges is more important in those districts where heavy farm machinery is moved than it is in the Eastern States. The illustration on the left shows a fatal accident caused by a farm tractor and trailer falling through a wooden trestle, resulting in two deaths. On the right is a typical grade crossing, with a dangerous sharp curve, in approaching which the driver’s back is toward many approaching trains thousand Americans each year, accord- ing to statistics compiled by road ex- perts. This number is as large as the casualities in many a day’s fighting in the world wide war. After much study, the State Highway Commission of Iowa is pushing vigorously a campaign for the building of permanent roads and bridges 226 killed and more than five thousand seriously injured in accidents on the highways. This means that in each state of the Union more than twenty- five persons meet death on the high- Ways in a year’s time. This loss of life and limb and the resultant destruction of property is

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Popular Science Monthly 227 Such bridges as these are responsible for many fatalities. When the spring rains cause the rivers torise, these light bridges are carried away, or so undermined that they cannot support the weight of an or- dinary automobile costing the country about twenty-five million dollars a year, a sum sufficient to build many miles of paved roads— an estimate based on an allowance of ten thousand dollars as the value of a human life. The loss in Iowa, econom- ic and real, is more than one million dollars. The greatest contributing factors to this huge death list are bad roads and bridges, speeding and reckless driving. The Iowa Highway Commission, realizing that it cannot put a stop to reckless driving and speeding, is work- ing on a plan to make the highways as safe as possible, and has succeeded in bringing about a material reduction in the number of accidents. Still, the commission realizes that even the safest roads will not make speeding entirely safe. It has begun a cam- paign against reckless driving. Second in the list comes the grade railroad crossing, which takes an un- usually heavy toll of lives and mangled limbs in a year’s time. There are eight thousand six hundred and sev- enty-six railroad crossings in Iowa, and of this number nine hundred have been classed as a constant menace to life by the commission. The work of remov- ing these dangerous crossings was taken up in a serious manner more than a year ago, and at the present time nearly one hundred of the nine hundred crossings are scheduled for improvement in 1916. Improvements were completed on eighteen crossings during 1915, The task of removing and relocating these bad crossings is a stupenduous one, the average cost of each change ordered so far being four thousand four hundred and forty-seven dollars. At this rate it would cost Iowa nearly twenty million dollars as her share of the improvement. The railroads must pay a sum equally as large, too, before these nine hundred crossings are made safe for ordinary travel. The question as to whether these costly improve- ments are worth while is best answer- Another view of the tractor and trailer which fell through a wooden trestle. The driver of the machine and his assistant died on the way to the hospital —E ee Tenner Scan igammmaneer em

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228 Popular Science Monthly ed by the reports for the year 1914, which show that fifty Iowans were killed on railroad crossings of this sort. The death toll from this source for 1915 has been almost as large. Immediately following a fatal acci- dent, when public opinion demands ac- tion on the part of the local authori- ties, plan and estimates of cost are worked out, and a tentative adjust- ment of the cost between the county and railroad is made. In the majority of cases the railroads have been willing net This old fort has been converted into a water tower, and is saving much expense to the town to co-operate with the state in remov- ing these sources of danger from the country highways. One railroad in particular relocated eleven dangerous crossings in one county. Dangerous turns in overhead cross- ings, bridges undermined during flood seasons, sharp turns in roads, “chuck” holes, ditches alongside roads, weeds and other obstructions on roads, un- guarded bridges, speeding on slippery roads, reckless driving at night, “short” culverts, steep embankments, neglect in placing warning signs or barricading dangerous places are some of the sources of danger the traveler in the country must encounter almost every day. The loss of more than 125 Iowans in the last two years has not been without some beneficial results, as a demand for the building of permanent roads has been crystalized as the re- sult of these sacrifices. It has been rather a costly manner in which to awaken the public to the need of these changes, however. Sprinkling Streets with the Aid of an old Fort NE of the many Martello towers or forts found around the coast in the Channel Islands has been put to a novel use. These buildings lie idle for the most part, having been built over a hun- dred years ago, and are now _ useless from a military point of view. In Jersey Island, however, a use has been found for one of these towers. It now forms the base of a water tank used for street-sprinkling. A windmill pumps water into the tank, thus saving considerable expense for- merly incurred when water was taken from the water company’s mains. Signal Lights for Traveling Cranes oa/ CERMEN employed in_ shops where a traveling crane is used are constantly on guard to see whether the crane is approaching them. This consumes a _ considerable amount of time, which, when multiplied by all the workmen so occupied in looking up at the crane, totals up to a formidable loss. An Ohio firm has placed on the market a device which is designed to warn the workmen, by means of red and green lights on the crane, whether the latter is coming toward, or moving away, from them. When the crane ap- proaches the observer, the red light au- tomatically lights, and when it departs from the observer, a green light gives the safety signal. The device has the advantage over warning gongs, which merely attract without telling the direc- tion in which the crane is moving.

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10 hE ee ee ee en 0 A ede Popular Science Monthly 229 This pneumatic chisel is installed in the sculptor’s studio, and greatly simplifies his work { The Sculptor’s Use of a Pneumatic Chisel for Artistic Carving INCE the very beginning of sculp- ture, the greatest difficulty encoun- tered by the creator has been in the mat- ter of outlining the marble. The only method known, until quite recently, was the tedious process of carving with mal- let and chisel and this was not only laborious, but awkward as well, for only one hand was left free to guide the chisel, the other being required to hold the statuary in place. Naturally the result was often crude and imperfect because of the limited strength of the one hand. Hans Schuler, the well-known Balti- more sculptor, was among the pioneers of those who broke away from this confining and hampering method. He installed in his studio what is known as a “pneumatic chisel”—literally a chisel operated by air. This is nothing more than the old chisel employed by the stone-cutter and carver. The device greatly simplifies the work and gives infinitely wider scope to the artist. It leaves both hands free. The chisel, in shape and size exactly like that of any ordinary stone-cutter’s, is driven by compressed air at a press- ure of seventy-seven pounds a square inch, operating through a long flexible tube, the air being compressed in a large tank by means of an electric motor. The chisel is pounded against the stone as if hit by a mallet, due to the air passing through the tube. It is amazing that the application of this long-known invention did not occur to sculptors several decades ago, but the efficacy of its use is well illustrated when it is realized that such eminent sculptors as Lorado Taft, Hans Schuler, and Ed- ward Berge make use of it exclusively. Of course it can be employed only in the rough modeling and in large figures, all of the finer and finishing work having to be done by hand as before. The amount of labor saved, however, is in- estimable. An Automobile Road Sign and a Map Combined HE Automobile Club of Southern California has installed guide signs at different points, which give a com- plete diagram of the good roads as well as the distances to the various towns and highways from that immediate dis- trict. The sign itself is complete and thus saves the motorist the trouble of consulting his own map, if he should have one with him. The point at which the sign is placed is designated on the diagram by a three-quarter red disk. Guides of this type are a great aid to the motoring public and save any amount of annoyances and inconveniences due to inaccurate directions so often picked up on the roadside. | A sign post that is a boon to the motorist 7 a tase Eas Seat e t DSP ne nF aS BRS ET I ae oes

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230 Popular Science Monthly Forest Rangers Must Fight Snakes as Well as Fires HE Forest Service is on the war path against rattlesnakes in the national forests. Many forest rangers have been bitten by. these venomous snakes from time to time, but the attention of the forest service was sharply called to the. necessity for the extinction of rattle- snakes by an episode which occurred during a recent forest fire. Several fires broke out in the Shasta National Forest, and a force of men was called to subdue it. After the fire was thought to be extinguished and the men were withdrawn it was discovered that one blaze had broken out again. A squad of men who returned to the scene ran into a section of brush that seemed literally alive with rattlesnakes. Six hours were spent in fighting the snakes before it was possible to enter the forest, and in the affray several men were bitten. Arrangements are now being com- pleted for the arming of forest guards and fire fighters against snake bites. The weapon to be given out consists of a small combination tool containing a sharp lancet and a receptacle to hold per- manganate of potash, which is declared to be the best antidote for snake bite. Making Butter by the Barrel. AIRY work is receiving much atten- tion in England during the war. The thousands of wounded and convales- cent soldiers in the hospitals through- out the British Isles consume tons of eggs, milk and butter every day, and it is extremely important that all of this material be of the very best. The accompanying illustration shows a monster churn which can make and wash six hundred pounds of butter at a single operation. This monster churn makes and washes six hundred pounds of butter at a single operation, and is exceeding valuable at this time in English hospitals, where wounded soldiers consume large quantities of dairy products by the orders of their doctors

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stgwenan: Popular Science Monthly 231 .This merry-go-round furnishes great en- joyment for bathers who must have water sports of a more or less reckless variety It is operated by an electric motor, and splashes the bathers in the water as it whirls them about A Merry-Go-Round in the Water. OR the entertainment of its patrons, who enjoy water sports of a more or less reckless variety, a recreation park on Lake Erie near Cleveland, Ohio, installed last summer a revolving mechanism for bathers which, in the form of pleasure it offers closely resembles the familiar merry-go-round, or carousal, of the state fair. . An iron framework similar in de- sign to an oil well derrick supports revolving arms to the outer ends of which cables are attached: The bath- ers swing and splash in the water as the arms revolve. An electric motor on a platform a few feet above water level is connected by gears to an up- tight rod through which power to re- volve the arms is applied. Motion Pictures on the Firing Line LETTER from the War Front in Europe gives an interesting descrip- tion for a motion picture theater near the firing line in Flanders. This theater is operated by several British army officers to provide relaxation and amusement for the troops when off active duty. There are usually two performances each evening, with a four reel program. The soldiers pay twelve cents admission, while the officers are charged a double amount. The expenses are very low, since most of the work is voluntary, and all profits are devoted to charity. The operator and pianist were both formerly employed in the same capacity at mo- tion picture theaters in London. The power for the lights and the machine is obtained by fastening a dynamo to an automobile. At first all the films were obtained from Paris, but the cost was so high that the theater was being operated at a loss. The lieutenant in charge of the theater then went to London to attempt to rent the films at a more reasonable price. When he had explained his de- sires to the officials of a prominent motion picture concern he was offered sixteen thousand feet of film monthly until their supply was exhausted. It is said that it is by no means un- usual to hear the reports of shells while the performance is progressing, as the firing line is but a short distance away. — aaneresr ei pONE OROOEN REREg SRT se ae Sn ST

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Inspecting the Inside of the Earth N mining for coal or metals, opera- tors must know a number of things about their claims in advance unless they are out- and-out gam- blers.. Before starting operations at a mine the thickness, extent and richness of the vein must be estimated in order to determine whether the mine can be worked profitably.’ The depth of the vein from the surface, the dip or angle at which it lies and the nature of the ma- terials that will be encountered before reaching paying values, are also factors of the greatest importance. In a word, the mine operator must have a good idea of the “lay of the land” in ad- vance, or he may be doomed to failure from the start. All of these questions are eas- four feet per hour. Several typical cores are illustrated. Figure i illustrates, in section, a core drill penetrating loose ma- terial composed of soft rock and earth. Here the cutting bit is shown with. several sharp cutting edges, and the core barrel is about three-quarters filled with the different kinds of rock that have been penetrated. Figure 2 shows a core drill employing a steel shot bit, which type is used for cutting hard, solid rock. The rod F extend- ing to the surface of the ground imparts a rotary motion to the cutting tool. As the drill sinks deeper and deeper, this rod is extended correspondingly by screwing pieces into it at the top. The rod is hollow and through it are fed water and very hard small steel shot. The shot set- ily answered in advance by means of core drills. Think of the way a corer takes out the heart of an apple and you have the main idea of the core drill. These drills have been used for taking samples out of the earth at varying depths from a few yards to several thou- sand feet. The speed of drilling, of course, depends upon the size of the core and the hardness of the rock, but the average is probably between two and Piles of cores from the drill. Here is a record of the contents of the earth for hun- dreds of feet below the surface How the drill samples the earth through which the bor- ing is made 232 tles, entering the diagonal slot near the bottom of the bit which feeds it beneath the rotating bit, as shown at L. Here the weight of the drill, combined with the abrasive qualities of the shot, rapidly ‘wears away the rock and permits the cutter to settle around the core. While the core is being made, the cut- tings are washed upwards by the stream of water and settle in the receptacle B, which is known as a calyx. This gives an additional record, in inverse order, of the rock and earth penetrated, the mater- ials being in pulverized form, suitable for assay purposes. Figure 3 illustrates this point and also shows how the core is broken preparatory to extracting a piece. For this purpose, pebbles are fed into the drill in place of the shot. They jam around the core near the bottom and break it off as the drill is rotated. This wedged material also holds the core in place while the drill is being raised to the surface. 4

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Popular Science Monthly 233 ee AINE AONE: These drills, while sinking deep into the ground, constantly send up samples of the earth for examination. They are in the form of solid rods, large or small (as here) With several soundings thus made in different parts of a property and accurate records kept of the material encountered at different depths, it is a simple matter to map the various underlying strata and eliminate absolutely all guesswork from subsequent operations. The Size of a Railway Station OVERS of statistics will be interest- ed to know that in the concourse of the express level of the Grand Central Station, New York, the old City Hall of that city could be placed with twenty- eight feet to spare at either end and with one foot clear on each side. The top of the statue on the City Hall would be nearly fifteen feet under the ceiling. The number of passengers handled annually at this great station increased from fif- ten million, seven hundred and fifty thousand in 1903 to twenty million, eight hundred thousand in 1914. In 1905, nine hundred and eighty-two thousand cars entered the station, and in 1914 there were one million, one hundred and twenty-six thousand. Fewer trains, however, are entering the station, for in 1905 there were two hundred and sever thousand eight hundred trains, while in 1914 there were but one hundred and eighty-two thousand five hundred. This decrease is due to the fact that more cars are hauled by the electric locomotives in one train than were hauled by the steam locomotives, and therefore fewer trains are required than heretofore. Fig. 1 Fig. 2 Fig. 3 Typical cores and how they are procured. Fig. 1. is working through loose material, with a sharp-pointed drill. Fig. 2 is using steel shot to cut through hard rock. Fig. 3 shows the use of water in cutting, also how pebbles are used to break and hold the core preparatory to stopping the work

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234 Popular Science Monthly Power from a Floating Water Power Plant ARMERS who have small streams running through their places are showing much interest in the portable and self-contained power. plant which has been designed and patented by A. G. Watkins of Philadelphia. The appara- tus can be used wherever water moves at the rate of two miles an hour, which is less than that of the average stream. The plant consists of two triangular floats fastened together by iron rods to form The float on one side houses a motor with a series of gear-wheels which mul- tiply the power to such a degree that a one-half horse power dynamo is effec- tively driven. The other side of the float contains a pump, and thus water or pow- er may be secured as desired. The float is anchored to a tree or any other con- venient object. Where more power is wanted several of these devices can be tied up one behind the other. The plant shown is the first which has been demonstrated by the inventor. It is shown on the surface of Carrol Creek Two triangular floats support the water wheel, which derives power from any stream flowing at a rate even as low as two miles an hour a channel of decreasing width. A water wheel is mounted in the narrow part. Between the floats and beneath the water there is an adjustable platform, set at a slight angle, so that, together with the floats, a wide-mouthed opening is form- ed, decreasing in its dimensions in three directions toward the wheel. This has the effect of increasing the volume of water passing through the narrow open- ing and acting on the blades of the wheel. at Frederick, Md. A line was run to the bridge appearing in the distance, where twenty incandescent lamps of six- teen candlepower each were operated. One of these plants will soon be in operation at St. Petersburg, Fla. It is said that the operation of the power plant in cold weather is not interfered with by ice for the reason that the motion of the water in the passage between the two floats prevents freezing. oe

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The Timber Hitch, a safe and simple knot usually em- ployed: in holding poles and booms. The turns in the loose end must be carefully made bo How to Make Knots, Ties, Hitches and Bends The Double Bow- line is used when the end cannot be used, and when a loop is desired in the bight The Single Bowline is one of the most important of all the hitches. It is very safe and will not slip or jam The Timber and Half Hitch. Much the same as the Timber Hitch with the addition of a half hitch to avoid any danger of the rope’s rolling The Blackwell Hitch, while safe for light loads, is likely to part under heavy strains & The Square or Reef b Knot is one of the safest ties, but care should be taken to avoid a “granny” A “safety-first’’ tie, the Cat’s Paw. This hitch will sustain'\heavy;loads, and is most us‘d for that reason t When the rope is too long, it may be shortened by the use of this knot, the Sheepshank — The first operation in preventing the dead end of a rope from ravelling The Clove Hitch is a very safe knot, and may be handl- ed very quickly The Stopper Hitch is used to hold the strain in the fall line of blocks 235 The second opera- tion in preventing the dead end of a rope from ravelling

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F people as a whole were aware of the importance that a tooth- brush plays in the healthful happiness of their entire body more attention would be paid to this perfunctory daily exercise. The soberness of this fact is perhaps a trifle more evident when it is mentioned that mouth infection is now known to be the source of numer- ous diseases that cause chronic sick- ness and eventually death. Looking upon the situation from the opposite side, it is equally true that mouth and The teeth and gums should be scrubbed with a circular motion five or six times in succession teeth cleansing is the chief means of preventing these diseases, and in many instances, curing them. A Philadelphia physician, who has gone more deeply than usual into this question, points out that mouth washes are of no value in the presence of bacterial masses, unless these are removed once a day at least. In other words, the mouth should be thorough- ly scrubbed daily. This physician lays even more stress The tooth brush should be small and the bristles short. The upper brush is similar to those usually bought. The lower brush is correct Brushing Your Teeth; There Is a Right and a Wrong Way upon the correct use of the toothbrush. He has calculated the antiseptic and 236 The spaces between the teeth should first be carefully cleaned with dental floss curative results brought about by the the use of the toothbrush on a mathe- matical basis. For example, the tooth brush being usually two inches long, generally re- duces the movement of the bristles to a half inch, which is almost all taken up by springing and pivoting, so that the actual friction amounts to very little, if anything. Therefore, considering that friction is a highly desirable factor, the ideal It is most important that the circular brushing should extend as far back in the mouth as possible tooth brush is one not over one inch and a quarter long with bristles not over a quarter of an inch in length. Bristles of this length will necessarily be stiff, but if the gums are soft and inflamed. a brisk rubbing is the best thing in the world for them, and will, in the course of a week or two, bring them back to a state of health again. The fact that the inflamed gums become sorer than usual during the first few days is an indication of self-poisoning, or autoinoculation, a condition and a result that should not exist in an otherwise healthy person.

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a ae ee a Fe ee = - —-— SS Te EA Popular Science Monthly 237 Care should be taken to follow the curve of the gum with the entire face of the tooth-brush Floss silk, so this physician has noted, is another great corrective for ailing teeth. The silk should be passed between teeth, across gums and drawn rapidly, even roughly. The discom- fort may be slight, but it is sufficient to cause most people to avoid the prac- tice, although they would perhaps be somewhat more enthusiastic towards this particular tooth cleanser if they knew that it would help greatly to- wards avoiding gout, rheumatism, val- vular heart disease and ulcer of the stomach. Concerning the general mechanics of tooth brushing, there are three im- portant actions to be borne in mind. The first is the rotary motion, where- by all the gums and the teeth in front of the second molars are cleansed by a vigorous whirling motion. Second, the drawing motion wherin the mid- dle of the brush is placed behind the wisdom teeth and drawn vigorously across the gums. Third, the drawing motion wherein the brush is placed back of the last molar and drawn sharply forward along the gum margins and the teeth. It may be mentioned that healthy gums can stand the same _ vigorous friction as can be borne with impun- ity by the finger nails. The midcie bristles of the brush should be placed at the back of the third upper molar and drawn briskly forward along the gum margin Hard-Pressed Germany Invents New Foods | granada sausages are being made in Germany which are said to taste a’ great deal like blood sausages, and are not a great deal lower in food value. The price of the potato sausages (called also K-sausages) is much less than the blood sausages. It was found possible in Germany to purify bacteria-carrying oysters by al- lowing a stream of pure, fresh, filtered sea-water to run over them, in tanks, for four or five days. No sickness resulted from eating these oysters. Study of the milk marketed in Zittau, Germany, up to the present time of the war shows that scarcity of good fodder for the cattle does not decrease the fat content of the milk, but only the quan- tity of the milk. This movement will clean the backs of the teeth which are too often neglected In Germany the comparative quality of the milk can be decided by the use of certain bacteria. Five are used, called respectively and alarmingly the “Danish streptococci,’ ‘“Jaroslawer di- plococci,” “Guntherschen diplococci,” “Russian lactic acid streptococci” and “Bacillus bulgaricus.” The Danish strep- tococci can live only in fairly good milk, the Jaroslawer diplococci in worse, and so on down the list until we reach the Bacillus bulgaricus, which is tough enough to live in very bad milk. How- ever, there is milk so bad that not even the accommodating Bacillus bulgaricus can live in it. An elderberry wine is being made in Germany which is so like grape wine that it can easily be used as an adulter- ant of grape wine. It can be detected by chemical analysis, however. New methods for determining husk residue in meals and flours have to be used, since the German war orders to grind more of the husk into the flours.

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Popular Science Monthly ‘“* Mare’s tail’? Cirrus clouds A small form of Alto-cumulus

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A Journey to Cloudland A majestic cumulus, passing into cumulus-nimbus. A very beautiful and common type HE clouds, like the stars, are among those common objects of Nature upon which men look, for the most part, with unseeing eyes. Some aspects of the clouds do, indeed, force themselves upon our attention—chiefly those that denote the imminence of a storm—but few of us realize to the full the beauty and scientific interest of the vapory pageant that is continually sweep- ing across our skies. Strange to say, many artists, skilled in painting land- scapes, are unable to paint plausible sky scenes. About half a century ago an English painter, Elijah Walton, pub- lished a book (now almost forgotten) in which he pointed out that the great ma- jority of out-door pictures, including those of the old masters, are very inac- curate in their skies. If the painter, whose business it is to observe Nature, has acquired so imperfect a knowledge of clouds, no wonder the average citi- zen needs instruction concerning them. At first sight, clouds seem infinitely 9) ~ various, yet with a little study one can assign them all to a few broad classes. The scientific classification of clouds dates from the year 1803, when an Eng- lish chemist, Luke Howard, published a description of seven cloud-types, to each of which he gave a Latin name. With a few additions and modifications, How- ard’s classification is now generally used by meteorologists. This system is based upon three fundamental forms: viz, fibrous or feathery clouds (cirrus), clouds with rounded tops (cumulus), and clouds arranged in horizontal sheets or layers (stratus). Intermediate forms are described by compounding the names of the primary types; e. g., cirro-cumu- lus, cirro-stratus, etc. There is really no good reason why the intelligent schoolboy, who. knows an oak from an elm and a crow from a turkey buzzard, should not be able to call the clouds by their names. The In- ternational Cloud Classification, now adopted for scientific purposes all over 39 a a ct

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Popular Science Monthly Cumulus mammatus clouds Alto-stratus clouds A nondescript form of alto-cumulus Nimbus (rain-cloud)

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PETE IE RH PERRO Popular Science Monthly 241 a Anvil-shaped cumulo nimbus the world, is brief and simple, and must serve as the point of departure in our excursion to Cloudland: I. Upper Clouds 1. Cirrus (“Mares’ Tails’). Detached clouds, delicate and fibrous, tak- ing the form of feathers. 2. Cirro-stratus. A thin, whitish, oft- en web-like sheet of cloud. II, Intermediate Clouds 3. Cirro-cumulus (“‘Mackerel sky’). Small globular masses or white flakes. 4. Alto-cumulus. Rather large globu- lar masses, white or grayish, part- ly shaded. 5. Alto-stratus. A thick sheet of gray or bluish cloud. III, Lower Clouds 6. Strato-cumulus. Large globular masses or rolls of dark cloud, oft- en covering the whole sky; espe- cially common in winter. 7. Nimbus. Dark, shapeless clouds attended by rain or snow. IV. Clouds Formed by Day in ’ Ascending Air Currents 8. Cumulus. Thick clouds with more or less rounded summits and flat bases. 9. Cumulo-nimbus (“Thundercloud” ). The common cloud of summer thunderstorms; a mountainous mass, often turret-shaped or an- vil-shaped, generally with a fibrous sheet spreading out above. V. High Fog 10. Stratum. A uniform layer of cloud resembling fog, but not resting on the ground. The international Classification also Strato-cumulus clouds recognizes a few minor types: especially fracto-nimbus, or “scud,” (shreds of nimbus seen drifting under the rain- cloud) ; fracto-cumulus (small detached fragments of cumulus, undergoing rap- id change in form), and fracto-stratus (formed when a uniform layer of strat- us is broken into irregular patches by wind or by mountains). Mammato-cu- mulus (“sack cloud,” or “pocky cloud”) is a rare and striking cloud form, seen especially in thundery .weather, consist- ing of rounded sack-like clouds, convex downwards. The photographs accompanying this article will help the reader to interpret the foregoing descriptions. There are several collections of such pictures, known as “cloud atlases,” of which the most important is the International Cloud Atlas, published in Paris, with de- scriptions in French, English and Ger- man. Equally useful, however, to the American student is the booklet entitled “Classification of Clouds,” with beauti- ful illustrations in color, issued by the Weather Bureau and sold at twenty-five cents a copy by the Superintendent of Documents, in Washington. The layman who has learned the cloud names given above will sometimes, per- haps, be puzzled to find a variety of other names applied to cloud forms by technical writers. The explanation is that many specialists have sought to in- troduce more elaborate cloud classifica- tions; in which, however, the Interna- tional nomenclature usually forms the substructure. None of these systems has ever come into general use. Clouds are Composed of Tiny Needles of Ice Turning, now, from the obvious to

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242 Popular Science Monthly the recondite, let us consider briefly the anatomy of a cloud. The highest clouds, cirrus, cirrostratus, and probably also true cirro-cumulus, with an average al- titude of six or seven miles above the earth, consist of tiny needles of ice. All other clouds are composed of drops of water, and do not differ at all in struc- ture from an ordinary fog, which is simply a cloud resting on the earth. These cloud particles are formed by the condensation of the invisible water- vapor (water in a gaseous state) which is at all times present in the air. Just as water-vapor condenses and becomes visible on the cold surface of an_ ice- pitcher, so, it is supposed, condensation occurs in the free air on the surface of extremely minute (mostly ultra-micro- scopic) grains of so-called “dust,” when cooled to the critical temperature with respect to the amount of water-vapor present (the ‘“dew-point’’). The exact nature of this “‘dust” is not fully under- stood. You will perhaps wonder how clouds composed of water can exist in cold weather, when our ponds and _ streams are all frozen to ice; especially as it is a matter of common knowledge that the temperature of the air diminishes with altitude, so that wintry weather on earth implies wintrier weather in Cloudland. To find the clue to this enigma we con- sult the books on physics, and learn that, with proper precautions, it is possible to cool a liquid far below its ordinary freezing point (32 degrees Fahr. in the case of water). Clouds of “supercooled” water-drops are seen even in the polar regions. A sudden jar turns a super- cooled liquid instantly to a solid; and thus it happens that, in cold weather, raindrops or fog particles turn to ice on coming in contact with terrestrial ob- jects, such as trees, telegraph wires, and the like, giving us the interesting spec- tacle of the “ice storm.” Clouds are Always Falling Another paradox is the fact that the bits of ice and drops of water composing the clouds should appear to “float” in the air, though of much greater density than the latter. As a matter of fact they do not. Cloud particles are all the time falling relatively to the air around them; though since this air itself may constitute an ascending current, they are not always falling in an absolute sense. The speed at which a cloud par- ticle falls through the air depends upon its size; the smaller the particle, the more slowly it falls. The smallest have diameters of the order of .0004 inch and fall in still air at the rate of about a tenth of an inch per second. The larg- est range up to more than a fifth of an inch in diameter, and fall at the rate of about twenty-six feet per second. Rain- drops and snowflakes are cloud particles which, in virtue of their size and other favorable conditions, succeed in falling all the way to the earth. Many a shower of rain or snow never reaches the earth, but evaporates in midair. Reverting to the aspects of clouds as we see them from the earth, there are a few interesting phenomena that require notice. Cirrus and cirro-stratus clouds sometimes occur in long, narrow strips, extending across the sky, and, while really parallel, seem to converge toward two opposite points on the horizon on account of perspective. These: strips are called “polar bands,” or, popularly, “Noah’s Ark.” Parallel bands of cloud, whether in continuous strips or in sep- arate cloudlets, reveal the presence of waves in the atmosphere. Where a wave carries a body of water vapor upward the latter cools by expansion and con- denses to visible moisture. Thus the clouds mark the crests of the waves. The ‘‘White Flag of the Chinook”’ A kindred phenomenon is that of the “cloud cap” often seen over a mountain. Here the ascent of the air, with its charge of water vapor, is due to the up- ward deflection of the wind by the slope of the mountain. Sometimes the cloud cap, once formed, spreads far away to leeward of the mountain peak, consti- tuting a “cloud banner.” Such is the “white flag of the chinook,” seen stretch- ing from the crest of a mountain ridge in our Western states when the chinook wind is blowing over it. The same phe- nomenon constitutes the “foehn wall” attending the foehn wind in the Alps. One of the most famous and striking of CRRA IEP INE AEE

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ee ae ces Popular Science Monthly 243 cloud caps is the “table cloth” that become fringed with feathery ice clouds, spreads itself over Table Mountain, near Cape Town, when a moist wind blows in from the sea. Sometimes the lo- called “false cirrus,” but really identical in structure with true cirrus or cirro- cal topography causes the wind that has swept up over the crest of the mountain to form a second “standing” atmospheric wave to leeward of the mountain, and this may also be marked by a cloud, which, like the cloud cap it- self, presents a de- lusive appearance of permanence, while it is really in constant process of formation on the windward side and dissipation on the leeward. The pair of clouds thus formed—one over the mountain and the other at some distance from it—is exemplified in the well-known “helm and bar” of Crossfell, in the Eng- lish Lake District. Of all clouds the most majestic are the mountainous masses of cumulo-nim- bus that attend our summer thunder- storms. The formation of these clouds can often be watched from its early stages. On a hot, still day the warm air near the earth’s surface streams upward by virtue of the same “convective” proc- ess that accounts for the draft of a chim- ney. The diminished pressure prevail- ing at higher levels permits the air to expand, and expansion causes it to cool. When the ascending column reaches a sufficiently low temperature, its water vapor condenses into cloud. The first visible stage is the appearance of a small cumulus, rounded above and flattened on the under surface, constituting the capi- tal of an invisible column of rising air. This occurs at an average altitude of from four thousand to five thousand feet above the earth. In the course of the afternoon one sees these clouds grow and coalesce, until they have towered up to enormous heights; often ten thousand feet or more. Very often the summits Alto-cumulus clouds Cumulus and alto-cumulus (above) stratus. Sooner or later the violent at- mospheric circulation that produces these clouds culminates in disruptive electrical discharges, rain, and hail. Similar clouds are not infrequently formed over great fires, and almost al- ways over a volcano in powerful erup- tion. In the latter case an actual thun- derstorm is commonly generated. Apart from their shapes, clouds pre- sent interesting phenomena of color and give rise to a great variety of luminous appearances, including rainbow, halos, coronas, and the like. These yield much information concerning the structure of the clouds in which any occur. Thus halos occur only in ice clouds, rainbows only in water clouds. The corona (not- withstanding statements found in many books on meteorology) probably never occurs in ice clouds, though it is some- times due to fine dust in the air. The colors of the rainbow, often described as ‘invariable, really differ considerably from one bow to another, according to the average size of the water drops in which they are generated. Beautiful iridescent colors may some- times be detected in clouds, especially along their borders, and not pertaining to a true halo, corona, or rainbow. ereeeMicratiicaintices-*>

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244 What Is Hoarfrost? N every-day English the word “rime” is synonymous with “hoarfrost” and is applied to the fine white deposit which replaces dew in cold weather. Hoarfrost is sometimes defined as “frozen dew,” but it is more often a direct deposit of small ice crystals from the atmosphere, the invisible water vapor turning to ice without passing through the liquid form. In recent technical literature the term Popular Science Monthly Of all these various frost deposits, true rime perhaps presents the most curi- ous forms, and these reach their fullest development on mountain summits and in the polar regions. Beautiful tufts and fringes of ice form on objects of small diameter, such as twigs and wires, and along the angles of square posts and the like, but not on broad surfaces. The deposit is almost or quite confined to the windward side, and grows against the wind. At the former meteorological observa- tory on Ben Nevis these ice feathers were sometimes seen to grow at the rate of two inches an hour. In the winter of 1884-5, according to Mr. R. T. Omond, “during a long continuance of strong southwesterly winds and cold weather a post four inches square grew into a slab of snow some five feet broad and one foot thick in less than a week; the crystalline mass then fell off by its own weight and a new set began to form.” The anemometers and other Hoarfrost is a powerful but cE * mischievous magician. Above, ee a beautiful effect created on a oe tree; on the right, a wire rope oe “rime” has a_ different pr age meaning. It is limited in ae: its application to those out-of-door instruments at the observatory were generally so coated with rime in winter as to be useless. A Curious Tobacco Pipe-Borer RAVELERS among the Sioux Indians are _ very much impressed with the per- fect smoothness of the bore in their pipe-stems. Without the use of a tool of any kind, they make a perfect bore in the twigs of ash trees, which they use for musical instruments and _ for pipes. To accomplish this end, striking deposits of. rough ice or of feathery crystals which sometimes form on _ exposed objects surrounded by fog, when the temperature is below freezing. This formation is, in its turn, distinguished from the smooth coating of ice which results from rain in cold weather, and to which the name “glazed frost” is now applied. Heavy deposits of glazed frost often load branches, wires, etc., to the breaking point, and give us the familiar phenomenon of an “ice storm.” they employ the larva of a but- terfly which inhabits the ash tree. The Indians remove the pith for about three inches from the stick they wish bored. Into this cavity, they place one of the larve of a brown butterfly, which gradually eats its way down through the pith until the bore is com- pleted. A little heat applied to the wood expedites the work of the larve. The Indians consider both the tube made in this way and the larva as sacred as their idols.

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Popular Science Monthly Q45 New York Trains That Play Leap Frog VERY interesting traffic situation occurs on the long and attenuated Manhattan Island, which makes only one express track necessary. In the morning, New Yorkers travel southward to the they are known technically, the local sta- tions are situated. The reason for the leapfrogging is ob- vious. There are three tracks in service already on the elevated line, but the third track could not be used for express serv- ice unless the trains crossed over and on Passengers riding on the express trains on the new “L” tracks will be reminded of the ‘‘roller coasters” at Coney Island down town business sections, and in the evening return northward to their homes. In order to relieve the swelling traffic on the elevated lines in New York city, an ingenious method of track-laying has been resorted to. A horizontal view of the completed structure would bear a strange resemblance to the roller coaster railroads so much in evidence in nearly all of America’s amusement parks. Near- ing a station, the express trains for which the new track is being designed, rise swiftly on an incline, so that they play at a modified, mechanical game of leapfrog. Under the raised tracks, or “humps,” as At each express station, the new tracks rise above the level used by the local trains the local tracks to take on and discharge passengers. This would involve delay and a serious possibility of accident, due to the failure of engineers to obey sig- nals. The stations selected for the express stops are either reinforced or renewed, and the middle track is raised abozt

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246 twelve feet. The loading platiorms for the “extra elevated” express tracks are built over the existing local tracks, which are left unchanged. The length of the “hump” is determined by the grade of the present local tracks at that particular section, as the grade of the express This device permits accurate timing of the revolutions of a machine tracks never exceeds three per cent. The new platforms are to be three hundred and fifty feet long. It is expected that the cost of opera- tion of the express trains will be some- what decreased as the headway which they get on the incline will carry them some distance before power need be ap- plied. Trains will also be able to stop quickly and smoothly because of the up- ward incline as they enter the station. Great credit is due the engineers en- gaged in the construction of the new tracks, for, with a few brief exceptions, traffic on the local tracks has not been interrupted. A Revolution Timer and Stop Watch Ingeniously Combined T takes skill to time the number of revolutions a machine is making per minute, especially if it is running rapidly. One’s attention is so divided between the watch and the revolution counter that it is difficult to start or stop the read- ing exactly on the second. In order to eliminate the human element and make Popular Science Monthly the reading positive, a Chicago man has connected the revolution counter elec- trically with the watch. Within the case of a stop watch is a tiny electro-magnet, which, when ener- gized, allows the second’s hand on the watch to run; but the instant the elec- tric current is broken and the magnet is no longer energized, the watch stops. The electric current is furnished by a flash-light dry battery attached to the revolution counter, and the counter it- self is so constructed that the electrical circuit is completed the instant the counter starts to revolve and is broken the instant it stops. The electrical mechanism does not in- terfere with the use of the watch, as a time piece or as a hand-operated stop- watch. The revolution counter may be used in the ordinary way if desired. The Danger of Safety-Tin Boiler Plugs. HE attention of the Bureau of Standards of the Department of Commerce has been called to a very seri- ous condition in the safety-tin boiler plugs used to warn engineers of dan- gerous boiler conditions. The plugs, which are made of fusible tin and which are supposed to melt easily when the temperature rises too high, were found on inspection to have become oxidized. Since the melting point of oxidized tin is about three thousand degrees Fahren- heit, one can readily see that the oxi- dized plugs, far from being a safety de- vice, actually increased the possibilities of danger from explosion. Lead and zinc impurities are found to be the prin- cipal causes of this oxidation in the tin; and their elimination by strict inspection is urgently advised by the federal au- thorities. Our Women Police P' )LICEWOMEN are now employed in twenty-six cities. Chicago has twenty-one; Baltimore, Los Angeles and Seattle, five each; Pittsburgh, four; San Francisco, Portland, Oregon, and St. Paul, three each; and Dayton, Topeka and Minneapolis, two each. Fifteen other cities have one each. Their pay ranges from $625 a year in Dayton to $1,200 in San Francisco.

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GUE T Rc tasS A et I i ' i Popular Science Monthly Q47 Charles M. Schwab Lifts a House over Trees: Sentiment vs. Cost HERE is real sentiment in trees to Charles M. Schwab, especially those trees which have sheltered his fine old homestead called “Immergrun” near Lo- retto, Pa. Recently Mr. Schwab decided to build a new palatial summer residence on the site of the old home, but he did not want to destroy the beautiful frame house ent location and will crown a little hill. The steel king intends to build a mil- lion dollar summer home in the heart of the cluster of trees that this jacking op- eration has saved. A Queer. Adventure in War ANY aeroplanes are captured dur- ing the fighting in Europe; seldom does an aeroplane land on an enemy’s aviation field without a fight. At an im- DW Age. angie i S =. Tbr r’ portant British aviation station in northern France a great German biplane was seen recently to emerge from the fog. As the anti- aircraft guns were about to fire upon it, the ma- chine circled several times around the field and final- ly alighted. Surprise changed to which has been more home to him than even his mansion on Riverside Drive, New York. The house is entirely sur- rounded by trees. To move it and not destroy the trees was no unsurmountable obstacle to the man who is furnishing guns and fighting ships for the Allies of Europe. When Schwab first spoke to his engineers about mov- ing the Loretto homestead, they mapped out for him a plan which sacrificed only three trees. But that was too much for Schwab. the problem again: The photographs herewith show them in the act of mov- ing the fine old Schwab residence over the trees. By the route that is being taken, the house goes over 23 trees be- fore it will reach the road where it will have clear sailing. The maximum height the house will be jacked over is thirty- four feet. It then starts on its journey across a deep valley on the Schwab farm where it will find a new resting place. It will travel a thousand feet from its pres- In order to move his old homestead without destroy- ing it and without killing the beautiful trees which surround it, Charles M. Schwab, President of the . Bethlehem Steel Co., told the engineers-to spare no So the engineers attacked expense. Accordingly they proceeded to jack the frame house up to a height of thirty-four feet. It will be necessary to lift the residence over twenty- three trees before it can be lowered amazement when the English aviators, mechanics and officers saw the German warplane drive quietly across the field and enter an empty hangar. The Ger- man aviators calmly said they had lost their way in the fog, and that on becom- ing short of fuel they decided to alight. Jokingly, one of the Germans remarked, = you will kindly give us a little petrol e should be able to return home.”

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Popular Science Monthly ~ x Nature has built the largest stadium in the world for the sport-loving population of Cleve- land, Ohio. Over one hundred thousand persons watched this baseball game, and thirty thousand more could have been accommodated A Natural Stadium Which Holds One Hundred and Thirty Thousand HE largest stadium in this country is not a product of engineering skill but the work of nature. More than one hundred thousand persons, the largest crowd that ever witnessed a baseball game, was assembled in this great bowl recently without taxing its capacity. It is estimated that it could accommodate one hundred and _ thirty thousand persons. The natural stadium is part of a city park in Cleveland, Ohio, and all athletic events which take place there are free to the public. It is almost a perfect amphitheatre. The large field, suitable for all kinds of athletic games, is almost completely surrounded by hills inclined at just the right degree to accommodate spectators. At one end there is a break in the hills that affords a convenient en- trance and parking space for auto- mobiles. Fifty Thousand Aviators O the average American, the aero- plane is still a wonder, a miracle, a creation of magic. In Europe men have become so accustomed to it, that children now talk of becoming “avia- tors” as they would of becoming “police- men.” Counting both pilots and ob- servers, there are more than fifty thou- sand men now in Europe, in daily flights above ground. The number in- creases from day to day, and before the war is ended it is possible that the num- ber will reach one hundred thousand. A hundred thousand human beings taken to the air every day—and only six years ago Glenn H. Curtiss made his first long flight down the Hudson River—a won- derful feat chronicled in the press of the world! Paper from Grass ERMINATING a series of experi- ments, the Department of Agricul- ture has recently announced that it is possible to manufacture a first-grade ma- chine finished printing paper from zaca- ton grass, which grows in great profu- sion from California and Texas south- ward to the Argentine Andes. This grass is harvested for the sake of its roots. These are made into brushes of various sorts, and are frequently known as broom root grass. At the pres- ent time the tops of the grass are allowed to go to waste. There is reason to be- lieve that from these a satisfactory pa- per-making material may be developed. a ara a alata SOMONE SESE TERE LAT

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Me i ee ll a4 te SPRING OPT Py PTE NETE PRUE Government Manufacture of Aeroplanes— A National Menace! By Eustace L. Adams manufacture of aeroplanes and motors. The specter which haunts those who hope to see the United States take her place among the nations with a fleet of aircraft whith will demand, and receive, respect! The ex- A GOVERNMENT factory for the turers. l¢xperiments may be conducted there which will evolve a highly valu- able type of military aeroplane. There a highly trained force may be created, and a training and industrial plant built up, capable of infinite expansion on the periment which cost Great Britain nearly five millions of dollars, and produced, al- together, fourteen flying of- ficers and seventeen aero- planes at the end of a wasted three years! There is a strong South- ern movement, of which Senator Duncan U. Fletcher is a leading spirit, to estab- lish at the new aeronautic base at Pensacola, Florida, a government factory for the manufacture of aeroplanes and motors for the Navy. It is on these grounds that Flor- ida hopes to see factories estab- lished to manufacture aeroplanes government’s 1,400 acres, which would be of service that cannot be estimated to the country in time of war. The government has an opportunity to build up a modern manufacturing plant, school and experi- A general view of the wharves at the new Aero Base at Pensacola, Florida Senator Fletcher, in defending his atti- tude, says: “I am strongly of the opinion that the aeronautic base (at Pensacola) should be equipped to manufacture aeroplanes and motors. Not to manufacture all that we may require, but a considerable number. This will act as a stimulus to private manufacturers, as a nucleus for a considerably increased output in war times, as a check on any tendency to- ward slackness on one hand, or too high prices on the other, by private manufac- ment station at Pensacola that will attract the best cf the official and enlisted personnel of the Navy as well as the most skilled workmen.” A year ago the Secretary of the Navy requested the Bureau of Construction and Repair and the Bureau of Steam Engineering to investigate and make a report upon the advisability of having the Navy enter upon the manufacture of aeroplanes. This report, which the Sec- retary transmitted to Congress, advised strongly against such an attempt. Some of the reasons: given were: “It would be a tremendous loss to the 249

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250 Popular Science Monthly advancement of aeronautical work to lose the ideas and results of private in- vestigation and experiment. The estab- lishing of a government plant for the general manufacture of aircraft would require a complement of officers that could be ill-spared at the present time, not only because the Navy has a very limited number of specially trained de- signers in this class of work, but be- cause such a plant would call for the di- version from actual flying work of many of the most competent operators. Any war, especially if the private manufac- turers had been driven out of business by government competition? At present, after a year and a half of warfare, and although private manufacture of aero- planes took a tremendous boom after the failure of the government’s experiment, Great Britain is forced to buy almost the entire output of the many American aeroplane factories. Should war be declared upon this country after the private manufacturers had ceased their efforts, because of gov- ernment competition, the government factory would not be able to supply the needs of our Army and Navy. It is conceivable that we might not be able to cross the ocean in search of privately manufactured aeroplanes. In that case we would have to build up the industry from _ the start, while thousands of enemy aeroplanes hummed over for a real aero corps government plant which could be estab- lished in the near future would be entire- ly inadequate in war time, as aircraft would be required in large quantities for such an emergency.” In spite of this report, the project is still being agitated, and numerous offi- cials appear to be in favor of establish- ing such a factory. Southern news- papers, particularly those conducted in Florida, are jubilant, but it is to be hoped that they are “counting their chickens before they are hatched.” Senator Fletcher says that government manufacture would act as a stimulus to private manufacturers. When did gov- ernment competition ever act as a stim- ulus to private manufacturers? Certain- ly not in Great Britain when the govern- ment was conducting its costly experi- ments along those lines. Great Britain found that by means of government manufacture it could not keep up with the foreign powers in times of peace. How did it hope to produce the thou- sands of aeroplanes necessary in time of The navy has a half dozen of these flying boats which can really fly. It should have five hundred as a basis our heads, and dropped bombs upon our ships and troops. Mr. Henry Woodhouse, a Governor of the Aero Club of America, in expressing his opinion of this project to the writer, said: “Manufacturing of aeroplanes and motors, which Senator Fletcher pro- poses, is inadvisable, first, because it would retard the development of naval aeronautics, and second, because it would discourage the youthful aero- nautic industry. Needless to add, there is, therefore, no argument in favor of the proposition.” There are many persons, interested in the problems of national defense, who see in such a project a real start toward a greater air fleet, and overlook the fact that it is a start in the wrong direction. It is probable that they cannot see the far-reaching evil results of such a step. On the other hand, a large number of far-seeing advocates for real prepared- ness are displaying great concern that so obvious a “pork barrel” proposition should receive even the most casual at- tention of Senators and Congressmen at a time when the nation seems at least

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Be aad Popular Science Monthly 251 An efficient private aeroplane factory. All these Curtiss machines are going to Europe. The aeroplanes in sight in this picture are almost double the number that either our Army or Navy Aero Corps has in commission, if only the serviceable machines in both services are counted awakening to the shocking condition of army and naval affairs, particularly in the branch of aeronautics. -.Mr. Alan Hawley, President of the Aero Club, the public-spirited organiza- tion that is leading the vast movement to supply the national guard and naval mil- itia of the various states with aeroplanes, said to the writer: “So long as the appropriations for aeronautics for the Army and Navy are not sufficient to meet the actual need for aeroplanes and for the training of avi- ators, there is no justification for spend- ing the small amount available for fac- tories and experiments. The dozen or so aeroplane manufacturers and aero motor makers have shown that they are able to supply, in any quantity needed, the type of aeroplanes and motors re- quired, and they have assured us that they will be at all times ready to do their utmost in every way to supply the aero- nautical needs of the Army and Navy.” Mr. Augustus Post, one of the fathers of the Aero Club, an experienced bal- loonist and a pioneer aviator, gives us his views on the matter. He says in part: “It would seem just at this time that it would be well to purchase what has already been perfected by the manufac- turers in this country and so well. prov-, en abroad, and that the Army and Navy might well devote their energies, at pres- ent at least, to training men to fly and in perfecting an aerial organization which could be moved where needed. The developments are bound to be so rapid in the near future that immediate steps must be taken to keep up with even the present rate of progress, and it would seem that rather than extensive laboratories, schools of flying should be established and the manufacture and in- ventive side of aeronautics left in the hands of those who are doing so well and who have accomplished so much.” As was pointed out in the last issue of the PopuLaR ScrENcE MonrTHLY, the aviation corps of our Army and Navy are at the present time, rather ghastly jokes. Congress has continually over- looked aeronautical needs, and the little money appropriated has been sadly mis- spent. A recent court martial of one of the officers of our Army Aero Corps afforded the public a glimpse into the rottenness of affairs when politics are applied to our infant aeronautical ef- forts. If government manufacture is NS aR TT aor aceaanane i ; | ;

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252 introduced at Pensacola, perhaps it will be the death blow to the hopes of those of us who wish to see the United States, the birthplace of self-sustained flight, provide for its Army and Navy a fleet of aircraft which in time of war would safeguard our Navy, our fortifications, and eventually our homes. Popular Science Monthly Making a Dancing Floor Into a Skating Rink EW YORK, the city of many fads and fashions, is now forsaking the dance floor for the ice skating rink, Dancing, which has held sway for three winters, was doomed to a slow death, even before a substitute was found. It needed only the advent “eet rt rt iu wan ane of a successful play in which an ice skating scene was the chief attraction to turn the tide in favor of the rink. Quick to see the coming change, the man- ager of one of the largest hotels in the city converted his famous dance floor into a skating rink, and at pres- ent has the largest in the city, with the exception of the permanent arenas which have catered to ice skaters for a number of years past. The rink is circular in shape, and consists of a shallow tank which holds five inches of ice. The The ice-skating rink which took the place of the popular dance floor in one of New York’s prominent hotels Our Big Birdseed Bill HEN one watches a_ canary daintily picking at its little box of birdseed, one is not likely to reflect upon the large quantity of that food which is eaten every year. Nevertheless, during the past year the canaries of this country consumed a total of four million seven hundred and four thousand six hundred and twenty-five pounds, or two thousand three hundred and fifty tons of birdseed. At the advanced price of five and one-half cents a pound which has been in force since the war made it difficult to import this material, the tiny birds have cost their owners two hundred and fifty-eight thousand seven hundred and fifty-four dollars and eighty-eight cents. HE average annual fire loss in the United States is about two dollars per inhabitant. water was frozen at the beginning of the season by the refrigerating plant of the hotel, and is to remain in that condition until the skating season is over. Every night, when the last skater has left the rink, the ice is scraped, and a slight film of water is sprinkled over the surface. When this water is frozen, it makes an entirely new surface for the next day’s sport. It is said that the rink was made at a cost of about twenty thousand dollars. Hazards of Aeroplane Making EROPLANE manufacturing must now be rated among the hazardous employments. At a foreign aeroplane factory a number of workmen employed in the varnishing department were taken seriously ill, and two deaths resulted. Upon careful investigation the cause was found to be poisoning by tetrachlor- ethane, an ingredient of the varnish used. These accidents led to an order forbidding the use of varnish containing a high percentage of this deadly chemical.

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Popular Science Monthly 253 A Business Office in the Open Air NE of the most remarkable testi- monials ever given for the fresh air cure is that of Roger Babson, the famous statistician, at his Wellesley Hills, Mass., office. The confinement of Mr. Babson’s work broke his health to such an extent that his physician ordered him to live in the open, even during his working hours. A large office, built in the rear of his building, was so arranged that it could be enclosed in stormy weather. As may be supposed and as our illustrations show, his office force is heavily clothed ; the altitude is high, and the thermometer often drops below the zero mark. The main difficulty was found in oper- ating their typewriters. It was neces- sary that the hands of the typists be pro- tected with heavy woolen mittens; but even with this covering, it was almost impossible to operate the machines with speed. The difficulty was solved when Mr. Babson suggested the use of two curved sticks. These are held one in each hand, to depress the keys, in much the manner that a Xylophone performer Roger Babson and his staff work in the open air. As the thermometer often drops below the zero mark, the office force must be heavily clothed. The heavy woolen mittens make it impossible to operate the machines with speed, so two curved sticks are provided with which the keys are de- pressed. Good speed is thus attained plays upon his instrument. After some practice, the stenographers become ex- pert in the use of these novel tools.

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HE engine and boiler room forces of a steamship need no longer die like rats in a trap when a steam pipe explodes and fills the compartment with scalding vapor, if the invention of Mr. Ernest H. Peabody and Walter b. Tardy, of New York, is adopted by any of the steamship companies. At present the life of coal-passers and engineers is one of extreme hazard, for in modern steamships the engines are driven by forced feed. This means that the boiler rooms are filled with air at a high pressure, driven into the compart- ments by means of a blower, and pass- ing into the fire boxes to give the flames greater heat. Toekeep the compartments under this pressure it is necessary for the men to enter or leave by means of air locks, where one door has to be shut before another is opened. This method of entrance and exit is, therefore, very slow, and should the compartment be- come suddenly filled with steam or nox- ious gases, all the men at work could not gain the outer air in time to save their lives. In order to obviate this difficulty, the inventors provide a tank extending from the engine or boiler room under the bulk- head to the adjacent compartment. In case of accident the men jump into the tank, and the force of their jump carries them under the bulkhead, which extends several inches under the surface of the water, thus shutting off the gas or steam from the adjacent compartment. When the men rise to the surface, they appear in the safe compartment on the other side, which compartment is fitted with an exit leading to the deck. The tank, which is constantly filled with water, is about eight feet deep, thus allowing those escaping to become completely submerged and to pass safely under the bulkhead. The water acts as an effective barrier to the escape of the steam or gases into the adjacent com- partment, and at the same time offers a ready means of hasty escape for men Saving Men trom Scalding Steam in Steamship Engine Rooms 254 who may be caught in the room when an accident occurs. A modification of the invention is shown in Fig. 2 of the illustration. In- stead of having the tank filled with water, a series of valves are arranged to blow a draught of air from the bottom of the empty tank. This blast will be forced upwards in that side of the tank located in the gas-filled compartment, and will blow back the steam or noxious gases, so that they can not pass under the bulkhead separating the two com- partments. A trap is set in the floor a few inches from the tank, so that the first man to reach the tank will step on the trap and open the air valves. Another modification specified by the inventors is the use of a large room be- tween the two compartments, which is operated in the manner of an ordinary air lock, but is so arranged that when the door is opened, a great quantity of water shall be sprayed from sprinklers in the ceiling, as shown in Fig. 3. This water will drive out or condense the steam or gases so that the men may pass through the room in safety. Testing Shrapnel Shells in Electric Ovens N electric oven for testing shrapnel shells has been introduced by a Chicago firm. This oven is for use in one of the government arsenals for the purpose of ascertaining the amount of heat which the shells can withstand. For twenty-four hours, each shrapnel shell must be exposed to a temperature of one hundred and twenty degrees Fahrenheit ; and by the use of an auto- matic thermostat the temperature is maintained at this point for the desired length of time. A pilot lamp outside the oven indicates whether the current is on or off. On a continuous test of more than twenty-four hours, the temperature in the oven did not vary more than one degree. — ET ROTORS ere seein RARE:

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As the photograph shows this huge ant-hill has been deserted by its original occupants to make room for two-legged inhabitants An Ant-Heap as a Look-out Station NE of the most destructive of African insects is the white ant. This strange little creature, well under an inch in length, erects huge heaps in which to dwell. In some places, particularly in the Congo, these heaps convert an otherwise flat country into a hilly one. They rise from twenty to fifty feet and more in height. In- variably they are crowned with several bamboo trees, which often attain a height of another thirty to forty feet. Then the heaps are often covered with beautiful ferns and the choicest of wild tropical flowers. The ants themselves are most de- structive, demolishing everything ex- cept iron and steel. They go about in vast armies, and in a single night the damage they will do is almost in- credible. They will enter huts or tents and attack everything that is not made of iron. Curiously enough, they only destroy that portion of the object that is not exposed to the air. For instance, they eat away the soles of boots, leav- ing the uppers standing in their place. It is only when you come to Popular Science Monthly pick up the object that you find it has been destroyed. The photograph de- picts a deserted ant heap in the Congo which the surveyors converted into a look-out station. Living In a Tree Stump | N the big timber section of the Pacific Northwest many huge fir and cedar stumps are to be found, reduced to mere shells through the action of fire or rot, Some of these stumps measure twelve feet in diameter. The pioneers of this region often util- ized these hollow stumps for cattle shel- ters, storage rooms or even as dwellings for short periods. If open to the sky, a roof of “shakes” was put on, which kept the interior dry. Open fires could be used, as the huge stumps acted as chimneys, creating an excellent draught. The accompanying photograph shows a big Washington cedar, in which four men lived for over two months some forty years ago. They were engaged in building a home for one of the party, who is pictured standing beside the stump, which he has carefully preserved. & Ek hs eg Four men lived for two months in this tree stump while building a permanent home LEAT LN TET I —EE + SONORAN RENE

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1S 40) ic ar re yt. ve il- »|- gS y, ch Id -air from the holds into a glass Popular Science Monthly 257 Detecting Fires in the Holds of Transatlantic Liners Y means of an apparatus which is now found on many of the large trans-Atlantic steamships, the officer on duty on the bridge can instantly de- tect any fire which breaks out in any of the holds or compartments. tubes leads into a bottle or container which is filled with lime water. If a fire should break out in a hold, the smoke is drawn into the terminal box for the tubes as before, but is itm- mediately drawn on until it reaches the glass jars containing lime water on the This efficient indicator con- sists of a set of pipes extending from each of the holds directly to the wheelhouse. At the ter- minals in the wheelhouse is a set of electric fans which draw case to which the pipes lead. Should a fire start in a hold, some of the smoke would be drawn through the tubes into the glass case, and would be no- ticed by the officer. As soon as the fire is discov- ered, the officer opens the case and fastens to the open end of the tube a steam pipe, which sends live steam through the tube into the compartment and smothers the blaze. This device has met with con- siderable objection among ships’ officers, because it was claimed that the noise of the electric fans was found very disturbing to the officer on duty, and also that the apparatus took up a large amount of space, particu- larly on large steamers with bridge or in the wheelhouse. The’ car- numerous compartments to be protected. In order to overcome these The moment a fire breaks out in the hold, it is detected by the officer in the pilot house and by the watchman on deck, by means of the system of tubes and fans indicated, which carry the objections, the inventor, Will- iam Rich, an American, living in Liv- erpool, England, has taken out pat- ents for improvements over his orig- inal device. A set of small glass cases, one serving for several compartments, is located on the bridge, or wheel- house, while the remainder of the appa- ratus is located in a more convenient part of the ship. In the terminal compart- ment for the tubes is a set of fans which draw the air from the holds, and an- other fan which serves to send a smaller amount of air from each of these tubes through pipes into the device in the wheelhouse. Each of these smaller smoke to the bridge or the deck bon dioxide carried up with the smoke turns the fluid to a milky color. The officer can then order live steam turned into the tubes to smother the fire. With this new device, all the fans and the cumbersome apparatus are located in a distant part of the ship, while only the small set of glass cases is found in the wheelhouse, where saving of space is of more importance. The chief advatages in the system ob- viously lie in the fact that a fire can be discovered immediately, and can be ex- tinguished quickly by means of the same apparatus, od Sietigt Se SS =

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258 Popular Science Monthly How to Sit Straight and Still be Comfortable HE ordinary straight-back chair encourages incorrect posture. It does not conform to the natural mould of the back. The sitter must assume a slouching attitude to be comfortable. The cushion fits into the small of the sitter’s back and encourages him to sit upright with the chest properly raised All this is remedied by a simple de- vice invented by Dr. J. H. Kellogg of Battle Creek, Michigan. The device is a small leather or cloth bound cushion which may be attached to any chair. This cushion is so placed that it fits into the small of the sitter’s back and en- ables him to sit upright, with chest properly raised and at the same time to be comfortable. - Concrete to Replace Willow Mats XPERIMENTS have been made by the United States Bureau of Stand- ards to develop a» method for accelerat- ing the hardening of concrete in order that concrete may be substituted for the willow mats that have been used in the past along the Mississippi River. As a result of the experiment, it was found that four per cent of calcium chloride added to the mixing water increases the strength of the one-day-old concrete one hundred per cent. Testing a Hack-Saw’s Strength N order to prove that a hack saw is an instrument of remarkable tensile strength, an experiment was recently con- ducted at Springfield, Mass. It was found that the thin steel would sustain without injury two hundred and eighty- two pounds, the weight of two men. Much damage is done to hack saws by too speedy operation, the operator often forgetting that it is the action, not the speed, that does the work. A hack saw should not be run faster than forty to sixty strokes a minute, and no blade. will stand a higher speed without injury, The thin hack-saw, although bending badly, is supporting two hundred and eighty-two pounds without damage to itself

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Popular Science Monthly 259 A Lens That Remains in Focus HEN dissecting small objects under a magnifying glass, and in many similar operations, inconven- ience is caused by the object’s continu- ally getting out of focus as the work progresses. An English inventor has hit upon an ingenious method of over- coming this difficulty by fixing the lens to the tool so that when once focused it will always follow the point of the instrument. The illustration shows a lens fitted to a teazing needle in a wooden holder for dissecting purposes. - The arrangement consists of a sliding sheath, A, capable of being slid to-and- fro along the holder, but gripping with sufficient force to maintain its position after adjustment. To this is pivoted an arm, B, to the other end of which a shorter arm, C, is similarly attached. The latter carries the lens, which may “be anything from two inches to three inches focal length, and from one inch to one and a quarter inch in diameter. A lens mounted in the manner des- cribed above, will be found a great con- vience for the purposes of microscop- ical and botanical: dissection, fine en- graving on metals and the more delicate photographic retouching. Provided the holdérs are round and of a size suited to the sliding sleeve the attachment may be fitted equally well to a dissecting knife, scalpel, teazing needle, steel scrib- er, or a photographic retouching pencil. When the ‘Microscope is properly adjusted, it remains in focus without further attention The wire-drainer clasps over the edge of the kettle and holds a row of doughnuts suspended so that they may drain Wisconsin Cook’s Doughnut-Drainer LONG-FELT want of the Ameri- can home has been a doughnut drainer, a device that would save the housewife from getting her fingers burned with spatterings of hot lard. Mrs. Lyda M. Schultz, of Dorchester, Wis., has devised one of wire that clasps over the edge of the doughnut kettle and holds a row of doughnuts suspended over the kettle where they drain off on being taken from the kettle. The doughnuts cook in less than half the time it requires without the drainer, according to Mrs. Schultz, thus saving fuel, time, energy and lard, and the doughnuts are better. The drainer is easily cleaned. A shake in hot water and it is ready to hang up-to dry. The drain- er can be used with equally good results in making shoe string potatoes, potato chips, fried oysters, dumplings, greens, vegetables, and even fried bacon. WITZERLAND is best supplied with postoffices. There is one for every nine hundred and _ sixteen in- habitants. ———————————

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does a ea se et ished Bes = 260 And Now Comes the Front-Wheel Drive Motor-Cycle MONG the many new forms of lo- comotion which are continually startling the public appears the front- wheel drive motor bicycle. This novel This front-wheel drive motor-cycle will run one hundred miles on one gallon of gasoline machine is equipped with a device very similar to the motor wheel to be seen on the street. The motor wheel in this case is actu- ally the front wheel of the bicycle, and it is claimed by the makers that it em- bodies the correct principle of pulling the load instead of pushing it. This method of construction permits of a di- rect transmission of power, the usual chain, belt or shaft drives being elim- inated. The front wheel bears the weight of the motor, while the weight of the rider is borne by the rear wheel. The motor is a single cylinder, four- cycle, and air cooled. It is said that it will drive the machine at a speed of twenty-five miles an hour for a distance of one hundred miles on one gallon of gasoline. Three-Wheeled ’Rickishas for Asia CONSIGNMENT of five hundred jinrickishas has been shipped to Calcutta, India, for distribution through- out the Orient, with the intention of eventually displacing the two-wheeled *rickishas now in use in Asiatic coun- tries. The two-wheeled ’rickishas have a great disadvantage in the unpleasant Popular Science Monthly way they often tip out the passenger when the coolie drops the handles to the ground. The new ’rickisha eliminates this disagreeable feature, and it pos- sesses an added advantage, because of having pedals, in keeping the feet of the coolie from the ground. Wet pavements and muddy roads-have been the cause of many deaths among the jinrickisha coolie population of Asia ever since that vehicle was first introduced by an enterprising American missionary in the lands where the ’rickisha reigns. Some of the new jinrickishas are provided with storage batteries and an electric motor, but the majority of them are driven by foot pedals. The gearing is comparatively low, to adapt the new ‘rickisha for hill climbing. Another consignment of five hundred of the vehicles will be shipped as soon as the American factory, where they are made, can turn them out. They are destined for India, China, Philippine Islands, Java, and the Straits Settle- ments. A Makeshift Polarity Indicator WO lengths of soldering wire at- tached to the two wires of a direct current circuit and suspended in a weak solution of sulphuric acid will serve as an emergency polarity indicator. After the wires have been in the solution for several seconds, one of them will be- come covered with a brown layer, in- dicating that the wire is connected to the positive side of the circuit. The brown layer is lead peroxide. Tricycle jinrickishas are now used in the Orient, thanks to American salesmen

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Popular Science Monthly 261 A Giant Metal Shoe PERFECT shoe more than fifteen times as large as the ordinary man’s shoe, and weighing five hundred pounds has just been made by a manu- facturer of Peoria, Ill. to be used as a part of an advertising sign. This giant shoe, fifteen times as large as an ordinary shoe, is complete in every detail, even to the eyelets and heel strap The shoe is made entirely of sheet metal and is seven feet six inches in height, fourteen feet long and four feet eight inches across the sole. It is com- plete in every detail, even to the eyelets and the strap for pulling it on, and is a perfect, magnified counterpart of the small shoe after which it was patterned. Painting Cars Rapidly PROCESS has been patented by which a railway car can be thoroughly painted, inside and out, in a fraction of the time usually re- quired. The car is first given a prim- ing coat and put in a drying oven which has a temperature of 250° F. After drying for three hours, it is re- moved and painted. Another three- hour period of baking follows, after which the car is ready for a second coat. This process is repeated until the car has not only been painted, but the necessary letters are also placed on the sides and it is varnished within. The length of time required depends upon the number of coats that are given and the quickness with which they are applied. Making An Automobile Tire Casing NE of the most interesting sights in almost any: one of the great tire factories are the great machines which are used in tire making. The one illustrated is used for making casings. Two men work together at each machine and their combined output is twenty-five finished cas- “™=rgq ings per day of ten working fo aN hours. pis Patterns conforming to the shape and size of the tire are mounted on a re- volving wheel. The opera- tor builds up a tread_on this foundation. From spools of prepared fabric, cut to the proper width, lengths un- wind automatically over the tire structure, the casing be- ing built up in successive layers. The number of fab- ric strips is governed by the sectional diameter of the tire. For example, a four inch tire requires five strips, a four and one-half inch tire, six strips, and the large five inch tire requires seven strips. These processes, of course, prepare the tire only for the ovens where it remains for varying periods according to the rub- ber stock, size of tire, and construction. One machine like this will turn out twenty- five finished automobile tires a day scraper enter EEE AAT ———— =

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ST Mpa A AH to 8 i ae re ee eee 262 Popular Science Monthly A Saw That Stands Up NE of the inconveniences of the ordinary handsaw is that it will not stand readily against a wall or a saw- horse. The least jar causes it to fall. This is neither good for the saw nor pleasant for the owner. A saw invented by a California man has two small teeth on the end of the blade which catch in The two small teeth prevent the saw from slipping when leaned against a box the floor just enough to keep it from slipping. With these points against the floor only a very slight support at the side is sufficient to keep the saw upright. Josef Hoffman Invents a Shock Absorber HE avocations of gen- ius are always interest- ing, and sometimes really valuable. The hobby of Jo- sef Hoffman is science and mechanics, and above all au- tomobiles. He has patented several automobile improve- ments. The latest of these is a pneumatic spring and shock absorber for automo- biles, on which he was re- cently granted a United sorber tends to bind when there is a side displacement between the body and the spring, as for example, on a curve. His pneumatic spring is an improved type which is designed to eliminate all the sliding contact both from between the parts of the pneumatic spring and from the parts of the steel springs. The device consists of a cylinder, a plunger, a diaphragm, and a connection between the ends of the steel springs and the plunger of the pneumatic spring. The plunger is guided solely by the air held with the cylinder, which contains the diaphragm. Thus, when once the plunger is set centrally within the cylin- der, the air will not permit the plunger head to get out of center; but if, by some unusual force, its center is dis- turbed, the plunger will immediately spring back to its normal position. A perfectly safe guiding of the plunger is thus provided, and all sliding contact eliminated. The diaphragm is made of a grooved fabric, so as to enable the compressed air in the cylinder to reduce the diam- eter of the plunger. This reduction in size permits the diaphragm to enter the cylinder, whose walls it has shortly be- fore been touching. The entire device may be connected to the body and the semielliptic springs of the ordinary car. This apparatus is inexpensive and so simple in its construction that it cannot readily get out of order. i States patent. Mr. Hoffman has found that the ordinary automo- bile spring or shock ab- pict ine f ems: 4 Josef Hoffman found the ordi- ————— ~ aa nary shock absorbers far from 2) soothing so he invented a pneumatic one of his own

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Sh <M Popular Science Monthly 263

is convenient to have such an arrange- ment to save her coming from upstairs or from the basement laundry. A Handy Darkroom Lamp LAMP that can be used for print- ing and lighting the developer tray while the print is being developed can be made by covering one side of a wooden or metal box with orange or ruby paper or glass and leaving the other side open. The covered side should cast its light on the developer tray, while the open side can be used for exposing the print. A Rolling Clock N oddity in the way of a clock has lately been invented by a young

When the tradesman shuts the door of this receptacle, it can be opened only from the inside of the house

jeweler in Los Angeles who claims that it is mere accurate than the ordit nary timepiece. The clock is placed upon the high end of a small table which is eighteen inches long and of polished ma- hogany. Gravity draws it to the other end of the in- cline, but the speed is con- trolled by a wonderful system of weights in the

Door Parcels-Receivers VERY housekeeper has_ times when no member of the family is at home when the day’s supply of milk or meat or groceries are de- livered. Some dealers will not leave parcels when there is no one to receive them. The milk and the meat tempt roving cats and dogs. In city homes, at least, the chance of human thievery has also to be considered. It is now pos- sible to have a special kitchen door fitted with four box-like compartments, one above the other. Each compartment is independent and is for a definite kind of . supplies. Each has a door opening outside and another inside the house. The tradesman finds the outer door un- locked and closes it upon his delivery, after which the receptacle can be opened only from within the kitchen. Even if the housekeeper be at home it clock. There are no springs and therefore no ‘winding. Every thirty days the clock runs the eighteen inches and is then taken up and started all over again. The case re- volves as it runs down, but the dial re- mains in the usual position.

It takes this clock thirty days to roll the length of the stand

a AR ig ens A

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The leverage is so great that three nuts may be easily cracked at the same time Cracking Nuts Three at a Time NEW vise-like utensil to crack nuts easily and quickly is de- signed for use in the kitchen in prepar- ing a large bowl of nuts for table con- sumption or cracking nuts for use in cakes or other confections. The new cracker consists of a small vise equipped with a large handle to give adequate leverage. A simple worm moves one of the vise jaws. The jaws are notched so that nuts of different sizes can be broken and so that more than one nut can be cracked at a time. The leverage obtained by this construction is so great that it is very little effort to operate the handle, a point that is of great importance in preparing brazil nuts or hickory nuts for the table. “Growing Pains” are Rheumatism CCORDING to Dr. Mary H. Wil- liams, an English specialist in dis- eases of childhood, “growing pains” are nothing but rheumatism in the vast ma- jority of cases. Popular Science Monthly A Bird-House That Can be Cleaned A BIRD-HOUSE that can be “house- cleaned” each year before the feathered tenants return from their southern pilgrimage has just been per- fected by J. C. Hubbard, a Battle Creek, Michigan, lover of birds. The new house obviates the loss that sometimes ensues because particular varieties of birds will not raise a second brood of youngsters in an old nest—they want new quarters for each nesting. The washable bird-house is made of a frame and a roof into which a hollow cylinder fits, held firmly in place by pegs. After the nesting season is over and the birds have gone south, the house can be cleaned by simply removing the pegs and allowing the cylinder to drop down. A garden hose is all that is needed to make the renovation complete. When the vernal migration is over the former occupant finds the old home clean and fresh and as inviting as a new house. By removing a few pegs, this bird-house may be opened and cleaned for the next coming of the birds

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Some RRS TEE re Popular Science Monthly 265 Aeroplane Drift and What It Means HEN making a flight between two distant points separated by water, or over strange ground on which there are no familiar landmarks, an aviator uses a compass like any sailor. He may find his bearings at any time during the trip by plotting a line on his chart in the direction in which he has been travelling. Then by estimating his rate of speed and the length of time he has been flying he obtains a point on this line which repre- sents his position at the moment. Such was the plan which Lieutenant Porte originally intended using in navigating the America on his proposed trans- atlantic flight. Serious errors are possible in steering by compass, because no correction is made for drift with the wind. Of course, there would be no drift in a per- fectly calm atmosphere; but the air is unfortunately a very unstable medium, filled with currents of varying velocity and direction, which insidiously divert air craft from‘their supposed line of flight. This is illustrated in Fig. 1, where the aeroplane is shown heading due north and the aviator naturally supposes that he is flying in that direction. A strong east wind is blowing and carrying him northwest. He cannot feel this wind be- cause he is moving with it and the longer he flies the farther he drifts from his objective. This matter had never re- ceived very serious consideration until the transatlantic flight of the America was planned, and then it loomed up as a serious problem. A gyroscopic stabil- izer had been installed and automatic control ensured, thereby relieving the aviators of much responsibility, save that of “setting the course.” Yet with the America wéll on her way there would have been no certainty as to where she would have landed, although the pilot might have kept her absolutely upon the compass course. The air compass, like the mariner’s compass, is provided with a mark known as the “lubber-line,” a line usually en- graved on the compass case and repre- senting the bow of the ship. Generally there is a corresponding line 180° dis- tant representing the ship’s stern. While ee Line Or Farcur Fig. 2 Fig. 2A Fig.3 Fig 3A Showing different wind conditions met by aviators during a flight, and on the right the corresponding readings on the drift indicator in each case the “compass needle,” is frequently re- ferred to, nautical compasses are pro- vided with a card to which several “needles” are affixed on the under side. This card, bearing the cardinal points, is held toward the north through the influ- ence of the earth’s magnetism. It will be seen, therefore, that when a northerly course is to be sailed the ship must be sO maneuvred as to bring the “N” on the card directly opposite the “lubber- line,’ as shown in Fig. 1A. Now let us again consider drift. Suppose we set our course as described and the conditions are those disclosed in Fig. 1. If we are flying at a reasonable height we see below us so much of the earth’s surface that we appear to be standing perfectly still in space; we know we are progressing because we would fall if we were not. We can rely only upon the compass for our sense of + : : h

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266 Popular Science Monthly direction. If we look at the earth through a telescope, however, we limit our field of vision to a comparatively small area, which rushes past so rapidly that we are unable to distinguish a single object. The earth seems to “flow” under us. If you have carefully followed the foregoing explanations you will be quite able to appreciate fully a drift indicator which has recently been developed and which is regarded as one of the most im- portant contributions to the science of aviation. The lubber-line is engraved on a mov- able ring mounted inside the compass and encircling the compass card. A tele- scope, provided with five fine cross-hairs, is mounted at any convenient location and so connected with the lubber-line ring that any movement of the telescope results in a corresponding movement of the ring. When the aeroplane is flying as in- dicated in Fig. 1, the positions of the lubber-line, the compass card and the cross-hairs of the telescope are as shown in Fig. 1A. Looking through the tele- scope the earth appears to flow in the direction of the wavy lines. We know the aeroplane is drifting, and at once we set the cross-hairs to parallel the lines of Dust from the mop falls through the sieve and is caught in the dustpan drift; the lubber-line is automatically and simultaneously moved in the same direction and to the exact number of de- grees. Fig. 2 shows the aeroplane fol- lowing the course unchanged, but the compass card Fig. 2A indicates our course to be actually northwest and not north. Fig. 3 and 3A show that the pilot has swung his craft around to meet the changed « onditions. While the aeroplane is heading northeast, the actual line of flight is now due north. Battery Wax Recipes. HERE is nothing better for the upper edges of glass cells or open-circuit batteries than hot paraffin. Brushed about the upper edge it pre- vents the sal ammoniac or other fluids from creeping up over the top. The paraffin can be colored, if neces- sary, with red lead, green dust, or pow- - ders of various kinds. Generally the paraffin is used without color, so that it has a frosted appearance when cool. A black wax for stopping the tops of dry cells and coating the tops of car- bons is composed of tar and pitch in equal parts. These are made into a pasty mass with turpentine heated over a stove, but not over an open flame be cause the ingredients are inflammable. The compound should be like very thick; molasses, so that it can be worked with an old knife. Another good black wax is composed of paraffin, eight parts; pitch, one part; lamp black, one part. Heat the mixture and stir it until thoroughly mixed. Ap- ply with a brush or dip the parts into the warm liquid. Oil Mop Cleaner and Dustpan HE oil or polish mop is coming into very general use in homes with finished floors. The dust is quickly picked up in the soft yarn mesh of the mop but the problem of remov- ing the dust from the mop then arises. A special cleaner has been devised which is also a dustpan. One holds it in place with a foot upon the short han- dle, and combs the mop back and forth over a perforated platform, the dust falling into the dustpan beneath. This can be used in the house as well as out of doors.

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Se ee | Slee SS “= = F a h ce oO T Mw. st 11S ut Popular Science Monthly 267 Applying Hot Road Material O be impervious to water and to re- 7 sist wear to the greatest possible degree, roadways must be impregnated with hot tar or some similar material. This condition demands vehicles which combine the necessary distributing ap- paratus with a plant for heating the road material. The truck illustrated herewith is of five tons capacity and is one of three re- cently installed in Baltimore, Md. The truck has a four cylinder gasoline motor, and this also operates a powerful air compressor with which the hot liquid is forced out on the roadway. .With the Forty-Niners ie historically important discovery of gold in California was made in January, 1848, at John Sutter’s mill on South Fork of American River near Co- loma, a point only ten or fifteen miles southeast of the town of Auburn. From 1850 to 1853 the greatest yield was de- rived from the gravels, and the largest annual output for this period was more than sixty-five million dollars in 1852. There was some reaction in 1854, due to previous wild speculation, but a produc- tion of about fifty million dollars a year, chiefly from placer mines, was main- tained up to the year 1861. To obtain the best results, the tar to be used in making roads must be sprayed while hot. A great tank truck has been built, which has a small boiler on the rear of the chassis to keep the material at the desired temperature The material within the tank is main- tained in a liquid state with the aid of a small flash-steam boiler, which is mounted at the back of the chassis and which may be fired with either kerosene or gasoline. From this generator, super- heated steam is led through the material in a continuous flow by means of pipe- coils, i Navres most remarkable gold and silver beetles are to be found in Central America. Some have the appearance of burnished gold while the others are like silver. They are worth $35 apiece. At first the gold was won chiefly from the gravels along the present streams. Those who first got possession of the rich bars on American, Yuba, Feather, and Stanislaus rivers and some of the smaller streams in the heart of the gold region, made at times from one thousand to five thousand dollars a day. In 1848 five hundred to seven hundred and fifty dollars a day was not unusual luck; but, on the other hand, the income of the great majority of miners was far less than that of men who seriously de- voted themselves to trade or even to common labor.

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268 An Adjustable Auto Foot-Pedal for Short-Legged Drivers HORT per- sons usually have difficulty in driving an auto- mobile because of the distance of control pedals from the seat. Especially is this the case in cars made in large quan- tity, where no allowances are made for the varying leg lengths of prospective owners and drivers. For the convenience of these short-legged persons there has been brought out the two-step extension pedal, which can be attached and adjust- ed in a few minutes. The pedal consists of two sections with a serrated joint, sim- ilar to that of the adjustable handlebars on bicycles. The pedal can be adjusted to suit any driver and is nickel plated. An Extra Seat for Ford Cars Which Hangs on the Door ROWDING one or two extra persons in- to a Ford car ap- pears to be rather more of a habit than before. Time has shown that a little Ford tour- ing car can be relied on to “ramble right along” with as many as seven people in it, and inventive geniuses are busy supplying additional seats. The accompanying illustration shows a neat, simple and very light seat, to be hung over the doors of the car. The hinges at the bottom of the hanging rods show that the seat can be folded flat. The device is finished in japan, with padded leather or pantasote seat. The hooks are also padded with leather to avoid marring the finish of the doors. Beeswax for Cracks and Holes HEN filling cracks and holes use beeswax instead of putty. Heat it until it is plastic and push it into the crack. Then sandpaper the wood around the crack and let the dust mix with the beeswax. . When the wood is stained, the crack will be hardly noticeable. Popular Science Monthly This Folding Motor Bucket Is Also a Game Bag WATER bucket which folds up and may be put in the door pocket or under the = cushions of an au- ~ tomobile is one of =: the most convenient °° of recent motor ac- cessories. It is made of heavy brown wa- terproof canvas and holds over a gallon. The only metal in the bucket is the top rim, which folds compactly, and when unfolded stays in position. To un- fold, the rims are pushed out iv the reg- ular size and the bucket is immediately ready for use. It may also be used as a fish or game bag, by leaving it flat and fastening a strap or small rope in the loops on the side of the bucket. This latter fact makes it especially handy for a long tour. A Machine for Cleaning Blackboard Erasers MECHAN- ICAL clean- er for blackboard erasers has been brought out which will entire- ly obviate the highly unpopular schoolroom task of beating the erasers on the window sills, with the unpleasant \ clouding of the |(O\\ room which ac- companies this operation. The apparatus consists of several pivoted handles with erasers fas- tened at the upper ends, an upright screen and a rotating shaft fitted with cams. Rotated by a handle at the end of the machine, the cams force the han- dles outward so that they descend brisk- ly upon the screen, thus driving out the chalk dust retained in the erasers. A fan whirling rapidly at one end of the screen blows the dust away from the operator.

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— WwW 8 eee YF UF a nn ners ‘ Popular Science Monthly 269 If You Only Have a Rope UPPOSE you are caught like a rat in a trap in a house on fire. Your only means of escape may be a dead wire, a loose rope, or sheets and blan- kets tied together to make a rope. Would you know how to slide down the rope or wire like a fireman or sailor? You will very likely say, as sixty odd univer- sity students re- plied w hen asked that question: “Ah, that is easy. Any- body can slide down a rope.” But can they? Boys are usually as agile as monkeys, and more likely in an emergency to be able to rescue themselves than others, yet a recent test of boy scouts with a rope lower- ed from the first story of a suppos- edly burning build- ing, proved that only two or three knew how to use a pole, a wire, twisted sheets or a rope in order to reach the ground safely. Sliding down a rope, like many other things, is simple enough—if you know how! If you lower yourself by letting the rope or wire slide and slip through your hands or touch any part of the uncov- ered flesh, the motion and friction will sting and tear your skin beyond endur- ance. This will cause you to let go and may produce serious results. By holding on with your hands and letting your weight go down, one hand over the other, you will not go far be- fore you are too tired to support your own body. Disaster will be the price, because you will drop like a shot. Nor can you slide with the rope between your legs, because the swaying will make the rope slip or will jerk it from its clutch. There is a right way, which secures to you almost the safety of walking on The correct way to slide down a rope solid ground. You stand upright and put out your leg, say the right, and give it a turn around the rope. Next put the rope into the crook of your elbow and there hold it firmly. Your hands and skin do not now touch the rough rope at any spot. You may slip down slowly or rapidly, but under complete control by bending or stiffening the body, to the security below. Your garments act as a shield to your flesh, and you have a fire-escape and rope-lad- der fit for safety, stratagems or adven- tures. A Bunsen Burner Flat Iron N Illinois man- ufacturer has placed on the mar- 4} ket a novel gas flat- E} iron which employs the principle of the Bunsen burner to keep it at an even temperature and to eliminate any out- side heating. Essentially; it consists of a hollow flat-iron, in the back of which is inserted a modified form of the simple and inexpensive burner. By its means the gas flame is directed down towards the point of the iron; and the intensity of the heat may be very easily regulated by the amount of air admitted to the tube attached to the back of the iron. A Hair-Drying Comb COMB with a hollow back for receiv- ing a hot iron is the essential idea contained in the illustration. The comb is the ex- ception that the back is hollow. A handle with a heating iron is provided as a part of the device. When it is de- sired to use the comb for drying the hair, the iron is heated in a gas flame and inserted into the back of the comb. Gradually the heat is conducted to the teeth, which are made of steel. Strok- ing the hair with the warm comb readily dries it, and, the inventor claims, leaves it in a lustrous, soft condition.

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= ck: STE Se aera = Short Cuts in Arithmetic HE principle described by Mr. Shourn in the November issue of the Poputar SciENcE MONTHLy as a “Short Cut in Multiplication,” can be used equally as well in addition, sub- traction and division, with slight varia- tions. To use his figures in Addition. 974265 — 33 — 6 84337 = 25 = 7 13 — 4 1058602 — 22 = 4 Subtraction. 974265 = 33 84337 — 25 8 —8 889928 — 44 =8 If the 33 and 25 were further reduced it would be 7 from 6, in that case 10 would have to be added to the six, and 1 subtracted from result, as below: 33: = 6 = 16 23=—-7= 7 9 1 8 Multiplication. 974265 = 33 = 6 84337 = 25 = 7 42 = 6 82166587305 = 51 = 6 Division. In division the division digits are mul- tiplied by those of the quotient and to the result the remainder is added, these must equal the sum of the digits of the dividend: Dividend — 974265 — 33 — 6 Division -—= 84337 = 25 = 7 Quotient —1146558 = 27 = 21/7 (7X 2) +1 = 15 =6 Dividend = 6 —L. E. F. That Mathematical Short Cut 270 Be Sure You're Right HOSE who read in the November number of the PorpuLaR ScIENCE MonTu_y the article entitled “Short-Cut Multiplication Proof” may be _ inter- ested to know that the principle of the method there discussed may also be ap- plied to the other three fundamental arithmetical processes. As a simple example suppose we di- vide 25 into 375. Our answer or quo- tient would be 15. Now let us reduce each one of these figures to its lowest terms, which, according to this process, means adding the 2 and 5 in the divisor, making 7. Then 3 plus 7 plus 5 in the dividend equals 15, and 1 plus 5 in the 15 makes 6, the lowest term of our divi- dend; and 1 plus 5 equals 6, the lowest term of our quotient. To prove the problem all that is necessary is to mul- tiply the lowest term of our quotient by the lowest term of our divisor. If our division was correct our answer will be the lowest term of the dividend. That is, in this case (quotient) 6 x (divisor), 7 equals 42; and as 4 plus 2 is 6, the same as the lowest term of our dividend, we know that our division was correct. , The following is an illustration of proving substraction : 5721 equals when the digits are oe NE eek emia ba hard ae 3545 equals when added 17, and 7" SS ere Teter 8 2176 equals when added 16, and 6 eee eer The same problem in ‘addition would be: 5721 equals 15 equals..... 6 3545 equals 17 equals..... 8 14 equals 5 -9206 equals 23 equals....... equals 5 With a little practice one may become very proficient in reducing the numbers to their lowest terms, thus making the process valuable for those who have to check over their own work. Trv it. —M. A. wore

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_— ee. Popular Science Monthl Hotel Keys Which Take the Place of Shouting Call Boys O longer will hotel clerks have to “page” the corridors, lobbies and bars when a visitor asks for a guest who cannot be found in his room. It will only be necessary to take the key which Mr. Jones has left at the desk, and after a glance say, “Mr. Jones may be found in the grill room.” The labor-saving device which will make this possible is a novel key tag which has recently been patented by a Chicago inventor. The tag, on which the num- ber of the room is stamped, is oval, and is imprinted with a clock face. By means of a pin in the center of the tag the key may be fastened so that it will act as the clock hand, indicating the approxi- mate time when the user expects to re- This key tells where to look for missing guests, when a pin is inserted to indi- cate the place where he can be found turn. On the outer edge of the tag are a series of small holes. Near these are stamped the names of the various public rooms of the hotel. Another pin is at- tached to the tag by means of a light cord or chain, and this may be placed in any of the holes, indicating the place where he may be found. Water That Cannot Be Cut FACTORY in Grenoble, France, utilizes the water of a reservoir sit- uated in the mountains at a height of two hundred yards. The water reaches the factory through a vertical tube of the same length, with a diameter con- siderably less than an inch, the jet being used to move a turbine. Experiments ee A stream of water under high pressure will break the blade of a sword if an attempt is made to cut it have showed that the strongest men can- not cut the jet with the best tempered sword; and in some instances the blade has been broken into fragments without deflecting a drop of the water, and with as much violence as a pane of glass may be shattered by a blow from an iron bar. It has been calculated that a jet of water a small fraction of an inch in thickness, moving with sufficient velocity, could not be cut by a rifle bullet. The engineers of some big water pow- er projects of the Far West are willing to wager that a two hundred pound man, swinging a four-pound ax with all his might, cannot make a “dent” in the wa- ter as it emerges from the nozzle at the power house. Burying an ax in a stream of water looks like child’s play, and the average two hundred pound visitor is likely “to bite.” He invariably loses. So great is the velocity of the water emerg- ing from the nozzle in these modern power plants that an ax, no matter how keen its edge, is whirled from the hands of the axman as soon as it touches the water. The water travels under a pres- sure exceeding 500 pounds to the square inch in many instances, and no power on earth can turn it off at the nozzle, once it gains mometum. It has the same ef- fect on one’s fingers as a rough emery wheel, and will shave a plank with the nicety of a razor-edged plane. When, as frequently happens, it is necessary to shut down a power plant operated by one of these streams, the nozzle is de- flected by means of a powerful set of gears. —————

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Seta FE Se i ER tape armani i ot eB A I = a ‘ ae. = r : — What’s New in Patents Little Inventions to Make Life Easy A New Headlight Dimmer SMALL searchlight is nested in one of an ordinary size, pro- viding two com- plete headlights, one within the oth- er. The _ larger one, when lighted, throws its beams in an anular ring of light past the headlight which has been nested therein. This makes a dim light. To make a brilliant light, both are illuminated at the same time. Keeping Your Sole Warm LAYER of thick felt or 1 rubber is sewed to 4a frame made of a resilient material, and shaped to fol- low the outline of the sole of a boot or shoe. At convenient points on the outside edge of the attachable outer sole are sewed projections or loops through which may be passed straps for secur- ing the outer sole to the sole of the shoe. Adjusting a Brush to Its Handle DETACH- ABLE and adjustable handle ~is fitted to the standard form of ‘brush by means of a slotted fork and held to the brush by means of a bolt and a winged nut, which may be tightened or loosened by the fingers. By means of this fastening, the handle may be secured to the brush at any desired angle, or it may be re- moved at will. 2 For Applying Chains to Wheels BAR, having a central spring clip de- signed to grip the spoke of a wheel, is provided with f; two hooks on each end. In applying anti-skid chains to the wheel, after adjusting the clip, the ends of the chains are each engaged on the hooks, which are stationary, and the chains are thus held firmly in position. ac) An Egg-Tester and Mailing Tube Combined SHEET of paper - board is rolled so that it tapered. On _ the larger end, the tube is so cut that it will fit the size of an egg held against it. A circular or other . piece of printed matter may be mailed in this tube, and the recipient may use it to test eggs, by pressing an egg against the end and looking toward the light through the smaller end. A Clothes Rack Dryer NUMBER of heavy wires are fitted with hooks at their low- er ends and sliding rings at the center and upper ends to form a collapsible clothes rack which can be fitted to an oil heater. By the sliding of the retaining rings, the device may be disengaged from the stove, collapsed, and stored in a small space,

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ed nd on. led ase nst ght the the nall AA TTT INET SS . Popular Science Monthly 273 Combined Coat Hanger and Trousers Stretcher CLOTHES hanger and trouser hanger are connected by a device which is commonly called a “lazy tongs.” When the trous- ers have been hung on the de- vice, the tongs are stretched as far as possible and locked, thus holding the trousers stretched. A coat and vest may be hung on this device at the same time by making use of the clothes hanger which forms the uppermost section of the apparatus. Making it Easy for the Birds CYLINDRI- CAL bird box is made of fire-clay or pot- tery and is fash- ioned on the out- side to resemble the trunk and bark of a tree. A : slanting roof, which projects well above the walls of the house to prevent the leakage of rain or water into the house, is provided with deep flanges to hold it securely in place. A circular hole is made in the side near the top for the free passage of the birds, and on the inside is a climbing strip lead- ing from the bottom to the side opening near the top to aid young birds or in- jured ones to reach the opening. A Simple Signal for Automobiles N one side of ; the rear light iis marked the word “Stop.” The light is mounted on a pivot, being actu- ated by a rod con- nected with the brake rod. When the brake is moved by the driver, the light turns, exposing the warning signal to the rear. Keeping Shampoo Soap Out of Your Ears WO ear pro- tectors are held in their prop- er places by means of a resilient metal band fitting under the chin. Passing over the top and front of the pro- tectors is a trough to catch liquid which might fall from the hair while the latter is being shampooed. The liquid passes over the top and is guided downward into the bowl, or if it falls against the front of the protect- or it is guided downward into two small cups or retainers which are suspended - from the front of the protectors. A Shaving Mug with a Soap Pump SHAVING gs mug is made with a false bot- tom to contain liq- uid soap. Passing into the soap reser- voir is a plunger which, when push- ed, allows a suffi- cient quantity of “ soap for one shave to pass into the water reservoir. Snapping the Snapping Turtle NUMBER of resilient wires are attached to the end of a long pole. Each wire is pro- vided at its lower extremity with a hook which is first bent inwardly and then outwardly. In use, when a turtle or tortoise is seen crawling upon a river bed, the operator, with a quick down- ward movement of the pole, forces the free ends of the gripping wires or fin- gers downward upon the shell back of the reptile. The wire fingers spread out- ward until they ride over the edge of the shell back. The shoulders formed by the shape of the wire fingers engage under the shell and grip it tightly.

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FEB TE Q74 Popular Science Monthly A Headlight Dimmer Operated from the Seat HOOD or shield, formed of a single piece of metal, is fitted to a pivot on each side of an au- tomobile headlight and equipped with an arm leading to a controlling lever. The shield, in its normal position, rests above the lamp, but when the con- trol lever is actuated from the driving seat, the shield pivots to the front of the lamp and deflects the rays of the search- light, so that the blinding light will not ‘dazzle an approaching pedestrian or driver. A Stepladder and Ironing Board DEVICE that will appeal to the housewife who desires compactness is a step-ladder at- tached to an iron- ing board by means of two pivots. A brace is secured to the legs of the ladder and engages the bot- tom rung and holds the ladder in place. A similar brace makes it into an ironing table. The combination when not in use can be folded together to save storage space. Increasing your Grip on the Golf Club HE palm and fingers of a glove are provided with a number of gripping surfaces composed of flex- ible leather. These are cut to such a shape that when — = the glove is encir- cling a golf-club the maximum amount of gripping space is in proximity to the club, thus insuring a firm grip. On the back of the glove are numerous ventilat- ing holes, which also add to the flexi- bility of the glove. It’s a Wise Man That Knows his own Tooth Brush De eee ee a tooth bruh eee is made of atrans- |4 fsoxnn | parent material and is provided with a deep longi- tudinal slot. Inthis [,- slot may be slipped {27 a label upon which is marked the name of the owner of the tooth brush. A plug is furnished to seal the open end of the slot, making the interior waterproof. By means of this device the name of the owner is permanently placed upon the instrument, and is not made illegible by handling or by the influence of water. A Sop to Feminine Vanity FAN is made with a small mirror placed on / the inside of one of the end blades. A small button on the same blade is designed for en- gagement with a hole in the adjacent blade. When the button is engaged in the hole, the mir- ror is concealed behind the adjacent blade, which does not open, with the rest of the fan. \hen it is designed to use the mirror, a slight pressure upon the end blade will free the button and ex- pose the hidden mirror. Making Potato Chips by Machine THREADED rod is set on a stationary arm which is provided with a clamp and set screw so that it may be secured to a table. On _ the arm, opposite the threaded arm, is mounted a pin and a knife blade. A po- tato is placed upon the pin, and by means of a handle the threaded arm is rotated, thus pushing the potato against the knife. In the process of turning the handle, the knife cuts the potato into strips suitable.

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{vw ws — Ts = y po- ans ted, the the into For Practical Workers To Prevent Bolt from Turning When Unscrewing Nut i) th HE bolt y will of- Miah ten turn in unscrewing nuts, and should it be a carriage bolt difficul- ty is often experienced in unscrew- =. ing the nut at all. The ac- com panying illustration shows a very simple method of preventing the bolt from turning, by This file prevents the bolt from turning simply clamping a coarse file over the head of it, as indicated. Saw Box HE saw box illustrated is one which has proven itself well worth while. In cutting a large number of pieces to the same length it was found that the old-fashioned box soon became inaccurate, due to the contact of the teeth of the saw with the edges of the guides. To obviate this trouble and se- cure a more permanent and serviceable box this one was designed. The drawing requires very little ex- planation. Hardwood, preferably maple, is used throughout. The saw is first equipped with the two strips of wood, one ,on either side. These are bolted on to the saw with two 14” x 1” stove bolts, heads and nuts set flush to allow the saw to pass between the vertical guides. The holes. may be readily punched in the saw by means of a good punch. Hold the saw on the end grain of a block of hardwood and keep the holes at least 84” from the edge, in order to avoid cracking the saw. As the saw will be found a little thicker at the heel than the point, as well as at the teeth, than the back, the boards will have to be dressed down to bring them the same thickness at every point, after they have been bolted on. Be quite certain to take the same amount from each board. Next work out the parts for the box and carefully assemble the boards at one end. Place the saw in position and assemble the boards on the other end, being certain that there is just enough play to allow the saw to move freely, but with no shake. A little beeswax or floor wax on all the guides will keep the saw moving freely and easily and will also prevent wear. An excellent depth gage can be ar- ranged as suggested in the sketch. A fine tooth saw will give best results. The saw is always available for other work by removing the screws and taking off the boards. The holes in no wise in- terfere. 3° xe x24 Ye" X3"X SAW LENGTH This saw box will be found more perma- nent and serviceable than the old-fashioned box 275

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276 Potato Roaster for Campers POTATO roaster for camping parties may be made from a sheet of stiff sheet metal—iron will usually be The potatoes are held on nails, and the heat circulates evenly the handiest—through which a number of nails spaced equally distant are driven. The potatoes are pushed upon the nails and the loaded tray lowered over the glowing coals of the camp fire. The heat circulates about the potatoes evenly; so they are roasted uniformly. An Electrical Peddler Chaser ROBABLY the greatest source of annoyance to the housewife is an- swering the door-bell for agents who peddle things not worth buying. A little device shown in the accom- panying sketch will save her much an- noyance. The little box is placed at the front door over the bell button on a level with the eye. It contains a sign which shows through a small window. The sign is operated similarly to an old- fashioned window shutter by an electro- / WE DO NOT This sign is guaranteed to rout any peddler Popular Science Monthly magnet ; when not in use the two leaves of the shutter lie horizontal as in the right-hand drawing. In this position the sign cannot be read. The leaves are hinged to a double-armed rod, which, in turn, rests on a long lever, the lever being pinioned very near the magnet on a small bracket. This increases the lift of the magnet, so that about a quarter of an inch of movement on the left end will give about an inch and a half at the right, which is sufficient to bring the leaves in a perpendicular position and to exhibit the sign, which is drawn back by gravity. A push button is situated at a point in the house from which a view of the front walk or porch may be obtained; or, if the front door contains a glass, near the kitchen door. When an agent rings the bell the button is pressed and he is dismissed by the sign. He can’t argue with this “Agent Chaser.” The nails have their heads filed to a point, and prevent the casks from slipping Prevents Casks Slipping While Unloading ILY barrels or casks give truckmen much trouble when they are loaded upon wagons or drays, owing to the ten- dency of the unwieldy object to slip on the ways which are placed between the truck or wagon floor and the sidewalk. This difficulty can be removed by driv- ing a row of stout nails into the ways and filing the heads to a sharp point. While not seriously marring the face of the casks, the points prevent them from slipping.

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Popular Science Monthly Q77 An Electric Toy Semaphore N electric semaphore, if used in connection with a toy electric rail- way, will be interesting as well as in- structive. ; Its construction requires an electro- magnet, (F) Fig. 1, pulling down an arm (A) when the magnet is energized. The arm is provided with a small ex- tension, so that it automatically shows the regulation colored lights at either po- sition of the arm. When at right an- gles to the standard it is supposed to signify “Stop” or “Danger,” and a tiny red light shows. When hanging down at 45° from the standard it signifies “Clear Track” and only a small white light is seen. Fig. 1. The semaphore, if properly painted, has a very realistic appearance Fig. 2 is the detail of the semaphore arm, which is made of light sheet brass or aluminum. The dimensions explain it thoroughly. The small lip which is to be bent outwards at right angles is the part to which the string (K) is at- tached. Dimensions for a magnet cover (B) that will fit over a magnet taken from a medium sized bell or buzzer are shown in Fig. 3. This should be made of light sheet brass or aluminum. Small lips are provided which are bent in and sol- dered or riveted to an adjoining side. The dotted lines indicate where the metal should be bent. No dimensions are giv- en for the small holes, their size de- pending on the size screw used to fasten the cover to the base. Fig. 2. Detail of the semaphore arm, showing dimensions The lamp (C), Fig. 4, is made of hard wood, 114” square, into which holes are bored as shown in the figure. Small 3% volt flashlight lamps fitted into min- lature sockets are put into the 14” hole as far as they will go. The end is then filled with putty so that it is lightproof. The %%” holes are covered with tissue paper, the top with white and the bot- tom with red. The lights may be con- nected in multiple or series, depending on the voltage of the current. If small telephone switchboard lights and the opals which fit into the switchboard sockets can be procured the holes may be bored smaller and a much neater ef- fect secured. The base (D) and the standard (E) are made of hard wood. The base should be about 14” thick. In Fig. 5, the plan of the arrangement of the parts is shown. The four small holes shown :} a ee is ies Nes Ne ere $s + 2 al 10 Mie et yf “ig -B New Nw ae. gegtigly Fig. 3. Dimensions for cover to fit magnet taken from bell or buzzer

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278 are for binding posts. Each element has its own set of binding posts. The rea- son for this is that some experimenters ‘ . have a step 4 / ed vt -—@F— down trans- re 1 former which would be suit- —— i @; el able for the : ee lights but Bearing point of semaphore arm cannot be used in con- nection with the magnet. No dimen- sions are giv- en for the spring (G), armature (H), or projection arm (Fig. 1), their size depending on the size magnet used. The spring (G) should be made of some spring metal, such as german silver or phosphor bronze. The armature (H) is made of soft iron and the projection arm of aluminum. The spring and arm are riveted to the armature. Fig. 4. Diagram showing con- struction of lamp \ (pO pe Se goo ; | eae eee ere ae ee L. H H : i ! - ' > ! Lash Yt ; a y Fig. 5. Plan of arrangement of parts, with dimensions An angle arm (J), holds the lamp to the standard. It should be about 1” wide and each arm about 1” long. The string (K) attached to the pro- jection arm is the means by which the semaphore arm is moved when the ar- mature is pulled down by the magnet. If a light brass chain is used in place of the string, the appearance is more real- istic. Fig. 7 shows the wiring diagram when used with one source of current. The key is a strap key or push-button, Popular Science Monthly placed at a distance from the \ semaphore. In Fig. 1, the T. arm is shown with the cur- . rent passing through the magnet. When completed and as- sembled, if the cover, base and lamp are painted black, the standard painted white and the semaphore arm painted red with two white stripes as shown it gives the semaphore a very realistic appearance. The semaphore need not be entirely electric as the sema- | phore arm can be constructed so that it will move with a lever instead of an electro- Lj { magnet. In such a case, its Li 4 construction will be much Fig. 6 simpler than when electricity is used. Saving Time in Tracing a Design ere age every worker, from the lady embroiderer to the machine shop designer, at some time has use for a symmetrical design, yet they us- ually go to the trouble of drawing each side out, or tracing one side. A far quicker and easier way is to use the following draughtsman’s method: Draw one half of the design out on tracing paper, or any strong tissue paper. Fold this over on top of the blank half, being careful that the crease comes exactly along the center line of the whole design. With a silver half-dollar, pass over the top of all us- ing a rapid to-and-fro stroke. The de- sign is now reproduced perfectly on the other half of the paper. For this work the pencil should not be too hard, F or B, or a common No. 2. I. Ui Key Wiring diagram when semaphore is operated with batteries Magnets Fig. 7.

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Popular Science Monthly 279 Enlarging a Runabout’s Capacity HE torpedo extension with which most runabouts are built is often inadequate for carrying packages or bun- dles of more than ordinary size. With some extra lumber, the capacity of a small au- tomobile may be con- siderably increased, as shown in the sketch. An extra box is so con- structed as to get tele- scopically into, and slide easily in and out of the main box on the rear of the car. When the hood is lifted and folded back, this extra drawer may be extend- ed into the hood and supported by it. In this way an extensible box is furnished which con- siderably increases the capacity of a runabout without decreasing its strength or detracting from its appearance. A Non-Spillable Funnel FUNNEL which will cease flow- ing automatically when the vessel into which the liquid is being poured reaches a certain height, can be devised by attaching a metal float to the tapering funnel-tip. The float is a small metal cylinder closed at both ends. Small brass When the funnel is filled the float rises and stops the flow tubes should be soldered on opposite sides of the float, as indicated in the drawing. Nails which will fit loosely in the tubes (to give the float free play) should be soldered at their points to the tip of the funnel, with the float in place. The extensible box is easily made and greatly enlarges the capacity of the car When liquid is poured into the funnel, it will flow past the float until the vessel is nearly filled, whereupon the doat will rise and check the funnel’s discharge. The funnel can then be withdrawn quick- ly, so that little or no liquid is lost. Mat-Making for Photographers ee a few spoiled plates and clean off the film. Cut off four pieces from a roll of passepartout, one for each edge of glass. Paste these on the glass along the edges, leaving an opening in the center of the glass a little smaller than the films or plates. In using this put the mask in the printing frame first, lay the film or plate on top, and print in the usual way. By making a number of masks with different size openings in the center, dif- ferent size films or plates can be printed. If a mask of special design is wanted, paste the loose mat on the glass, as it saves‘time, and also prevents the mat from being lost, torn or creased. Passepartout tape can be bought at any art store for 10 cents a roll of 12 dozen yards. This will make all the dif- ferent size masks wanted, and there will be enough left over to passepartout a number of prints.

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280 Shock Absorbers FTER a season without shock ab- sorbers on an automobile and a sea- son with them, a driver will be thorough- iy. convinced of their worth. Here are given sketches and descriptions of a type which can be built by anyone handy with tools. The advantages of shock absorb- ers may be summed up in three words: comfort, speed and saving. With shock absorbers a light car equals in riding quality cars of much greater weight and longer wheel base. A speed of five to ten miles more per hour is practicable. The WU == Ls HH} HHH — Ho lo) pe rea] | : eae 6a = 0~ wan These shock absorbers may be made with the aid of a few good tools saving is in the general wear and tear on the machine and especially in the tires. The absorbers shown here are fairly simple in construction, requiring no welding or other difficult forging opera- tions and but the simplest of machine shop operations, that of drilling. The rear absorber is somewhat simpler than the front one. Eight of the brackets shown are worked up. The hole in the top is formed by bending the piece of %" x ¥%," mild steel around the proper size pin. The size of this hole is not given, as it will vary, in some cases be- Popular Science Monthly ing %” and in others 9/16”, depending on the make of car. This is a matter which the maker must determine before ordering the stock. Cold rolled steel is used for all bolts. The width of the spring leaf will determine the length of the bolts. After the brackets have all been bent up a clip is placed around the neck of each. Some of the 4” x 34” stock is used for these. The clip is first made- U-shaped and then placed over the neck while hot and the ends clinched or bent over. These ends should be just long enough to come together when bent over. The cross bar at the bottom of the rear absorber is made long enough to support the side of the springs. This bar is made from 14” x 1” stock. The bottoms of the brackets having been bent to shape, the cross bar is held in position and the holes drilled. Rivets of 1%” are used to hold these parts together, but before fastening finally the springs must first be provided and fit on the brackets. It is best to round the corners of the brackets to form a better support for the. spring as well as to prevent the coils becoming nicked, thus causing them to weaken and finally break. Owing to the method of attaching front springs in use on almost all types of cars, the design of the front shock absorber must be radically different from that of the back. Here the pull is up instead of down, so the coil springs must be held rigid at the upper end and links used to transmit the shock down and un- der the bottom ends of the coil springs, which in this case are the free ends. A study of the sketch will show the con- struction clearly. In order to prevent the springs coming up over the bracket too far a set screw is placed in each side of each bracket as suggested in the sketches. A 1%” set screw is heavy enough for this. The link is detailed in the sketch, except the size of the holes which will be determined by the size of the holes in the spring. The bottom cross bar is cut off even with the edge of the bracket instead of allowing it to extend as in the case of that on the rear absorb- er. The corners are again ground round before assembling the springs in place permanently.

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. a ee eo i ie ee ee col nw Popular Science Monthly . 281 The weight of the car will determine the size wire to be used in the coil springs; 3/16” for the front springs and y,” for the rear ones 1s about right for a car in the 2,000 pound class. This is figured for a touring car where five pas- sengers are to be carried. In the case of the roadster the rear springs could be of one size smaller wire. In the case of cars materially heavier the size of the wire should be increased. In order that the springs may carry the load properly they must be made 1” longer than the place they are expected to fill. This means that when they are assembled in the finished shock absorber, they are already under compression. According- ly those for the front absorbers should be 6” and those for the rear springs 7” long. The inside diameter of the springs should be not less than 114” in any case. Those fortunate enough to have ac- cess to a machine shop can wind their own springs if desired, although there will be no great saving as the springs will be made up as ordered by any good spring manufacturer for about twenty- five cents each. When placing the absorbers on the car they should first have their springs com- pressed and tied down with wire in order that they will not interfere with placing the bolts through. To compress them, use a cabinet clamp or vise. The entire cost of the absorbers de- scribed was just $3.34 outside of the work. Key Controls Battery Current HIRE batteries are placed on bicycles or motorcycles for light- ing purposes, it is a great temptation to mischievous boys to turn the current on, a circumstance which, of course, means a loss of money to the owner of the vehicle. Such happenings can be averted if a lock switch is employed for con- trolling the battery current. If ‘ahh nit \ U @ vif 4$- 1 Fig IT When the key is withdrawn, the auto-thief or mischievous boy is foiled The batteries should be placed in a metal cylinder, the ends of which. are plugged with wooden discs. On one of these discs a small drawer lock is fasten- ed. At one side of the lock—the side from which the bolt emerges when the key is turned—a brass or phosphor- bronze contact spring should be fas- tened.. When the key is turned, the bolt pushes this spring against a brass con- tact, and current flows from the bat- teries to the lamps. Eliminates Pants’ Guards for Bicycle Riders CHAIN guard can be made for bicycles which will dispense with the need of pants guards. A circular piece of stiff metal, having a diameter 1” greater than that of the A circular piece of metal protects the trousers from the sprocket gear large sprocket, should be cut and crimped along the edge. Clamps should be fashioned from heavy steel or iron for the purpose of grasping the spokes of the sprocket. The clamps should. be soldered to one face of the protecting disc and holes bored through the two. Machine screws pass throug’. the holes, terminating in tapped holes in similar clamps on the opposite side. A Try-Square Aid HEN using a try-square to deter- mine if stock is true, one cannot remember all the high and low spots. If the edge of the try-square is dipped in lamp black before using, and is then run on the piece, all the high spots will be black while the low places will remain untouched.

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282 ‘ How a Jack Knife Can be Used as a Compass POCKET knife that has two blades - at one end can be =<; converted, with the use of a pen- cil, into a make- shift drawing compass. One blade should be opened entirely ; the other only half way, so that they form a right angle. The blade that is half opened is placed point down on the paper, while a pencil is fastened to the other, and the circle drawn.

Enlarging Without Dividers RAW a straight line on a strip of cel- \ luloid or tracing ‘\\ cloth, and with a thumb tack fix the strip on co- ordinate paper in such a way that the line always intersects axis XX, YY. This, of course, is best done on a drawing board. By swinging the free end of the strip to any position between the axes, any proportion is obtainable. The principle of triangles, by which the proportions are obtained, is so well known that further explanation seems unnecessary. Still, here is a concrete example: Let us suppose that we want to make a drawing twice the dimensions of an original. Measure a distance of 2” along the horizontal as indicated and locate the point P. Then shift the strip until the vertical distance to the central line is exactly 1”. We then have the ratio 2 to 1 as desired. Every hori- zontal distance from the axis of the strip is twice the vertical distance. Should the desired ratio be 4 to I or 3 to I, or anything else, the same method is easily and consistently followed.

Bending Brass Tubes Without Kinking RASS tubes can be bent without kinking if they are previously filled with fine sand. Both ends of the tube should be closed with wooden plugs.

Popular Science Monthly A Self-Lighting Arc Light ROCURE a a \

tin can about 6” in diameter de. and cut three “i T\ holes in the side { « \ about 3” from the a }] back, as shown ¥ y/ in the drawing. The two holes AA must hold a sec- tion of rubber hose tightly. A short porcelain tube QO is put in the third hole. The hose holds the carbon F stiff while the carbon F is loose in the insula- tion. The carbon is supported at X by a piece of No. 25 gage German silver wire about 6” long. This wire runs through the tube B to the binding post D. The binding post D is fastened to a wooden plug in the end of the tube Q. The tube is adjusted so that the end of the carbon £ touches the end of F. The wires leading to the light circuit are connected with the binding post D and the end of the carbon F. A resist- ance, consisting of about 15’ of No. 25 gage German silver wire, is inserted at R. When the current is turned on it ex- pands the wire C, pushing the carbon E away from F, forming an arc. When the current is shut off and the wire cools, the carbons are drawn together ready for relighting. / / An Ingenious Electric Connector LeCTRic onnectors for low voltage cir- cuits can be made from the small metal cases that are used for storing pen points. Holes should be bored in the ends of each half and binding posts attached, as shown in the sketch. This connector can be used for battery circuits.

To Prevent Rust OOLS which are kept in a damp cellar can be protected from rust very easily, if a pan containing un- slacked lime is placed under the bench. The moisture is entirely absorbed by the lime.

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Popular Science Monthly 283 Rinsing Photographic Negatives Without Running Water MATEUR photographers who are compelled to labor under the dif- ficulties of developing prints and nega- tives without the aid of running water, If the pail is high . ( rg) enough, a service- =y/ SS able spray will fall = 5) mn the plates =F on (SE \ will find the apparatus which is shown in the drawings to be of considerable assistance. Water is syphoned through a small tube from a pail, the tube lead- ing to the center of a developing tray where it is bent upwards at a right angle. If the pail is elevated to a sufficient height above the tray, the pressure will cause a spray, which will be distributed evenly over the emulsion surface. The used water is syphoned from a corner of the tray by another tube. e Small Screws in Difficult Places T \AB a bit of beeswax on the head of ihe screw and push the point of the screw-driver through the wax and into the slot of the screw. The screw will be held in just the right position for driving home. Or again, if the screws are of steel the driver may be magnetized by stroking it a few times with a magnet. Its insertion will then become much easier. If the slot in the head is very shallow, the screw will be likely to slide over and stick to the blade of the screw-driver. In this case, use the bees-wax. Of course, it is evident that the hold on the screw is very light and can be used only to drive a screw into its cor- responding tap. For inserting wood screws the above methods are out of the question. A Mysterious Motor HE “Mysterious Motor” will puz- zle any one. Not only the novice, but professional electricians must do a deal of thinking to decide how it runs. The little toy consists of an electro- magnet over which is suspended a four-spoked iron wheel mounted on a thick wooden base. When placed upon a flat metal surface the motor will run, but when set upon a non-conductor it will remain motionless. The thick base is hollowed out from the bottom to make sufficient room for a small flash-light battery. Four brass tacks are driven into the base. From one of these tacks runs a wire to the thin copper brush, to which the iron wheel acts as a comutator and arma- ture combined. The current passes through the brush into the wheel, thence through the support to the coil. From the coil it passes on to one pole of the battery and from the opposite pole to another tack. This leaves the circuit broken between the two tacks, when the brush is in contact with the iron wheel. Consequently, when the device is placed upon a conductor the circuit is closed and the wheel revolves. The remainder of the cavity occu- pied by the battery is plugged with wood, and the base covered with heavy blotting paper, allowing the tacks to protrude. Much amusement may be derived from the “Mysterious Motor,” at a party by announcing that you have a motor that will gather its power from the air, when placed upon any metal, and then giving a demonstration. When the motor is placed upon metal it will operate; on wood, it refuses to move

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284 Filter for Lubricating Oil : ew apparatus to be described was made for the purpose of filtering oil pumped from the crankcase of a ma- rine gas engine after it had been used in the cylinders and bearings of the engine. The oil filtered out perfectly » 4. => ] lop view of stand ” HI Fig 2 IN y 4 ‘\ } “Ww 4 , he 8 ET \ y) é fF L fig. The oil is poured into the container through the paper filter, and collects in the container to be drawn when needed clear and was used over and over with — perfect success. Referring to the drawings, A is the container, made of zinc with soldered and riveted seams, about 16” high and 14” in diameter. On one end of the cylinder A was soldered the cone-shaped part D with a 3¢” brass pipe coupling E soldered into the small end. A brass shut-off cock F was screwed into this coupling as shown. A loose-fitting cover was made to fit the open end of the con- tainer. This cover B was about 14” larger in diameter than the container, and had a handle C riveted on to the top. To support this container a ring of Popular Science Monthly strap iron was riveted together and three legs riveted on, as shown, with holes for holding down screws bored in the feet. Three angle pieces of sheet iron H H H, were riveted on to the ring G for the bot- tom of the container to rest on. Another ring J was riveted together of a size to slip easily into the container. Then a cone was made up of copper wire gauze K and soldered to the bottom of the ring J as shown. Two or three sheet iron clips L L, riveted to J and bent over the outside edge of the con- tainer, served to hold the cone in place. This wire gauze is intended as a support for the filter paper, which is folded up into a cone as shown in Fig. 4 and placed inside the wire gauze cone. The oil is then poured into the paper and will slowly filter through and collect in the bottom of the container. It can either be drawn off by the valve as needed or be allowed to run through all the time and be col- lected in a can or other recep- tacle. It may require some experi- menting to find the best kind of paper to use, but for oil such as “Havoline” or “Monogram” or- dinary brown wrapping paper or even newspaper is perfectly sat- isfactory. Unsized paper is of course preferable, because of its ® porous character. Fuse for Storage Battery Circuits PIECE of glass tubing of small diameter is cut into pieces about one inch long. Small holes are drilled in the bottoms of used cartridge shells. The shells should be as nearly the size of the tubes as possible. They are then put on the ends of the tubes and a short length of German silver wire is put through the holes in the shells and soldered. The size of the wire can best be determined by experiment. Two fuses made in this way are fastened to a block of wood by four small clips and the fuse block is done.

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ee 0 ce ee he O O ee ed Popular Science Monthly 285 A Way of Fastening Machine Parts N building models of machines, en- gines, etc., the amateur is sometimes confronted with a case somewhat like that shown. The shaft A is of small diam- eter; the hub of the gear B is a great deal larger than neces- sary, requiring a large diam- eter taperpin C. If this pin is driven in as shown in Fig. 1, it will weaken the shaft, but if the pin is driven in as shown in Fig. 2, the shaft is only weakened slightly. The pin C in Fig. 7 can shear or break or twist at points D, but when the pin is driven as shown in Fig. 2, this is impos- sible and the shaft and pin will carry a far greater load than the old conventional way of pinning as shown in Fig, 1. A Capacity Job OME small stands had been de- signed both to length and size at the bottom so that they would fill the lathe completely. When it came to facing the top and bottom of the stands By means of the arrangement shown in the lower cut, the lathe is able to take larger stands. The upper cut is the original arrangement of the lathe it was discovered that the carriage could not be moved far enough to the right to allow the cross slide on which the tool is mounted to be moved in and out, it lacking only a few inches. Old method of pinning on the left; new mee efficient way on the right The tailstock was fastened down by means of two bolts passing through a wide plate. The bolts were taken out and the plate removed. The plate used for holding the center rest down was used instead. As this plate was only one-half as wide as the regular plate, it was fastened under the left- hand bolt of the tailstock, thus allow- ing the tailstock to be moved back far enough. The carriage could now be moved to the right, thereby allowing the cross slide to shift in and out. Before being able to run the car- riage close up against the tailstock it was necessary to remove the split nut used in thread cutting, as this nut struck the lead-screw and feed-rod bearings. The drawings show clearly how the gain was made. A Good Belt Compound. GOOD belt compound is made from equal parts of resin and light machine oil. Boil the mixture for about 20 minutes. Use when cool by pouring a little, drop by drop, on the moving belt. Not only will a good gripping surface be secured, but the compound will also act as a preservative.

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286 Sleigh Attachment for Perambulators WO runners are attached to a crank- handle, so that by moving the han- dle they may be suspended above the lev- el of the wheels or dropped below the This perambulator may be a sleigh in winter or a carriage in summer level of the wheels. Thus the perambu- lator may be used as a sleigh—or as a wheeled vehicle, at the will of the op- erator. Ice Skates Make Shoe Shining Stand ISCARDED ice skates of the type which clamp the soles of the shoe by the turn of a lever can be used for foot rests on shoe shining stands. The steel runner should be bolted between blocks of wood that are nailed or screwed to the foot rest base. With foot rests of this sort, the nervous customer cannot without difficulty, jerk his foot from under the hand or brush of the polisher. \ Guatersuat hates i DS Belts helding shgte —— Hi Bern Li Kestenng blocks ~“: With foot rests made from ice-skates, the customer cannot escape Popular Science Monthly Substitute for Large, Gas Reservoir N apparatus that will take the place of the large and cumbersome reservoirs used in chemical laboratories for storing quantities of gas for experi- ments can be made with two four-liter bottles and several connecting tubes. Referring to the drawing, A and C in- dicate the bottles. A mouth is cut in the side of A and plugged with a rubber cork bored out to accommodate a glass tube. The tube leads from B into the bottle C through a pinch cock inserted at D. Gas is generated from an appara- tus leading to tube E and is stored in the lower bottle. When pinch cock D is released the gas is forced out of C through tube E until the supply is ex- hausted. Water in the upper bottle forces the gas from the lower bottle through the tube E. This apparatus supplies gas for labora- tory experiments Prevents Insulation Unwinding HE waxed cotton insulation of an- nunciator wire can be prevented from unwinding by unravelling a length of both layers and knotting them. As the layers are wrapped in opposite di- rections the knot will prevent further unravelling or slipping. Drilling Holes in Glass HE following mixture on the de- sired size steel drill; will do a neat smooth hole. Turpentine Machine oil Use on point of drill at high speed. This formula is one used by optical grinders.

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Popular Science Monthly Hydraulic Blowing Arrangement HE apparatus here described will be found very useful for supplying air to small blow-pipes in glass-working, etc., also for wood-burning and in jew- elers’ work, as it leaves both hands free to work. By reversing the valve it may be used for purposes requiring a small suction. Fig. 1. for supplying air to small blow-pipes, as it leaves the hands free The hydraulic blower is useful The apparatus is simple and easily constructed. Fig. 1 shows the general plan, where 4 and B are cans of the de- sired capacity (1 gal. being a good size) mounted on the wooden frame work with a pipe containing a faucet, H, sol- dered between them. The cans are fast- ened to the wood with a metal clip, E, which is screwed to the wood and solder- ed to the cans. The inner framework is mounted on a shaft, G, supported by the outer framework, and the cans are kept from turning by the pin, F. The tubes, T: Ts, should be made of copper or brass where they extend into the cans and the part outside the cans may be of copper, brass or rubber. To operate, the top can is filled with water and the rubber tube 7, which leads to the blow-pipe or other appara- tus, is connected to the lower can. The faucet H is then opened, permitting the water to flow from the top can into the lower one, thus forcing the air out of the latter, the flow of air being regulated by the flow of water. 287 When the top can is empty the posi- tion of the cans is reversed and the hose is changed to the lower can. To do away with the changing of the hose, however, a very simple valve, which works automatically with the re- versing of the cans, may be used. The materials needed for the valve are as follows: 1144” of 1%” brass tubing, three pieces brass tubing 34” long to fit in rubher hose, 114” of brass rod with 8/32” thread, four 8/32” nuts, four 34” brass washers, two 14” leather washers, and two 4/36” screws. The 14” brass tube T (Fig. 2) is drilled for the tubes Tz, T2 and T3 and drilled and tapped for the machine screws S. The small tubes are then sol- dered to the large one as shown. The nuts D and leather washers B and brass washers C are placed on the shaft, which is then inserted in T after adjustment for right between head distances. The screws SS are put in to prevent the moving part from slipping out either end. The valves should be oiled and the corresponding tubes connected. The weight W is made of lead just heavy enough to work the valve. The valve is placed on the framework to which the cans are fastened. When the valve is in the position shown the air comes from the lower can through 73, through the valve, and out of T1 to the blow-pipe or other appara- tus, while T2 is open to receive air. Inverting the weight shifts the valve so that the blow-pipe or other apparatus is always connected with the lower can. qT, Fig. 2. Showing how the brass tube is tapped for tubes and screws

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288 Popular Science Monthly Emergency Bolts WO short bolts may often be made to serve as one long one as shown in Figs. 1 and 2, when no long bolts are at hand. The two bolts A and B are The nuts shown practically double the length of the bolts coupled together by means of the nut C. When two timbers are to be fastened together as shown in Fig. 2, it may be necessary to drill a recess M in one of the pieces to hold the coupling nut C but often the bolt is used in the manner shown in Fig. 1, where there are two projecting end pieces. In this case it will not be necessary to make room for the nut. Renewable Fuses N attachment plug can be con- verted into a renewable fuse by re- moving the flexible cord and connecting a length of fuse wire across the ter- minals. The plug should be inserted in series with the apparatus. . Mica-- fuse The attachment plug is converted into a renewable fuse The Care of Paint Brushes HOSE who have only occasional use for paint brushes find difficulty in caring for them, as it is expensive to buy new brushes for every job. The following will solve the problem: Procure a dish (a tin can will do) and fill with water high enough to cover the bristles of the brushes. Then pour in a small quantity of lubricating or ma- chine oil. Next wrap the bristles in paper, kept in place with an elastic band or a tied string, and place in the dish of water with the oil floating on top. The oil prevents the evaporation of the water and the rusting of the iron brush parts. The paper wrapping keeps the bristles in shape, and prevents contact with the oil. Lengthens Life of Blow-Torch Burners HEN used constantly, the brass tube through which the flame of a blow torch passes is rapidly burned away, so that complete new burners Money is saved when the burner of the blow torch is made detachable must be frequently attached. This rather costly procedure can be avoided if the actual “business end” of the burn- er is made detachable, or renewable. Several short lengths of brass pipe, equaling in size that of the burner it- self, should be procured. With a hack- saw cut off an inch or so from the end of the burner and thread the remaining end. A narrow ferrule, or coupling, should be tapped to fit the threads, and the brass tips threaded to correspond with the shortened burner. When one tip is burned down, it can be quickly re- placed by a new one. °

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HIS article presents a_ simple T method of binding magazines and the like into book form and illustrates novel and easily made tools for use in the work. The tools and the method can also be used for re-binding old books. The principal tool required is the press, which is shown in plan view Fig. 1, and end elevation Fig. 2. Two jaws of surfaced wood 2x3 x 24 FE== inches are united by two bolts % x 13 inches. These bolts are common iron bolts, but the threads must be cut down to about 314 inches from their heads. The heads of the bolts may be counter- sunk into the jaw and a strip of wood 1% x 2 x 24 inches nailed over them. Strips of wood 34x14x6 inches are nailed to the under side of the jaws, close to their ends. These strips slide in contact with the outside of the wood- en box upon which the press is placed and serve to keep the press in position over the box. Two press boards 1x6x 16 inches, having beveled edges, are used with the press. The drawings show the assembled sections of a book in the press, ready for making the saw cuts into the back as described later on. Fig. 3, represents the sewing frame. This is made by nailing a board upon

fs = SSS Qx“— <SSSSSNN SSSSS SNS - | LL Lh i | 4 Yj |

————— te wen, —— SAA

HUM Le Cae r — 1. The press-plan view Binding Magazines Into Book Form

two strips of wood 2x2x12 inches. The board may be about 10 inches wide. An .iron rod %g inch in diameter is bent to the form shown and its ends are in- serted into holes drilled into the pro- jecting strips, about 14 inch from the edge of the board. These holes are not

289 Fig. 2. The press: end elevation drilled entirely through the wood. Hori- zontal holes are drilled to meet the ver- tical ones and the ends of the lower hori- zontal rod are inserted therein before the top board is nailed upon the strips. Arrange the numbers of the magazine which are to constitute the volume in their proper order. Carefully separate and remove from the magazine or old book, one at a time, the sections of which it is composed and stack them in order in a pile. Take four sheets of strong white paper, about 14 inch larger all around than an open sheet of the maga- zine and fold them the same way the magazine sheets are folded, to be used for end papers. The folds or joints of two of these sheets should be strength- ened by pasting upon them strips of thin white cloth 1 inch wide, using white paste. When the paste is dry, re-fold the sheets and press the folds down flat. Arrange the four end sheets in order with a plain folded sheet and a sheet having a cloth joint, for each side of the book. Gather the sections of the vol- ume, with the end papers in place, be- tween the thumbs and fingers and rap them into line along the back and top edges. Place a press board upon each side of the book as shown in Fig. 2. The boards should be placed parallel with the book and about \% inch from it. Hold the book between the press boards with

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290 | Popular Science Monthly the thumbs and fingers and carefully lower it between the jaws of the press. Now hold the book with the left hand, and, using a wrench with the right hand, clamp the jaws of the press against the press boards. Mark five lines across the back of the book in the relative positions shown in i € B= S— | —_— AE, S SS82222Z ZEEE ee SSS = Di SO ZZ = oo ’ \ \ Fig. 3. The sewing frame Fig. 3, using a pencil and a try square. If a try square is not at hand, a squared piece of card board may be used. Guided by these lines, make five saw cuts into the book. The depth of these cuts should be 1-16 inch or less, or just sufficient fo show when the sections are again opened. A miter box or “back” saw is best for sawing the two-cuts nearest the ends but a wider saw may be used for making the three central cuts. After sawing, the book is re~ moved from the press. Tie three strong cords to the rods of the sewing frame as in Fig. 3. These cords must be long enough to project about 114 inch on each side beyond the edge of the book after it is taken from the sewing frame. Cords may be made of strong linen threads folded and twisted together several times. Usually the operator sits in front of the sewing frame, but it is best to sit at the end of the frame, since one can, in this po- sition, see the inside as well as the back of the sections and the arm has more freedom when sewing with long threads. The upper halves of the sections may be opened and fastened to the upper rod by means of spring clothes pins, so that the center of the sections will be visible and the leaves will be kept out of the way while sewing. Place a section of the folded end pa- pers upon the sewing frame and slide the cords B, C, D, upon the rods until their position corresponds with the three central saw cuts. The right size of thread to use for sewing will vary with the size of the book and the number of sections it is to contain. For six num- bers of magazines No. 25 linen will be about the right size. It is best to use unbleached thread. The method of sew- ing is shown in Fig. 4, B, C, D, repre- senting the cords that are tied to the sewing frame and the fine line S, the sewing thread. With the right hand, pass the threaded needle in at the end saw cut E, receive the needle with the left hand and pass it out at the next saw cut. Carry the thread around D and in again at the same cut. Sew around the cords C and B in the same way. Pass the needle out at A, draw the thread out until about two inches are left projecting at S. Lay the title page section of the book or magazine face downward upon the end papers already sewn. . Pass the needle in at catch stitch mark A of this section, sew around B, C, B, and pass the needle out at E and draw the thread down with fairly strong tension, looking to see that it lies straight within the section. The thread should now be tied to the projecting thread S of the previously sewn section. Pro- ceed in like manner to sew all the sec- tions to the cords. When the needle has been drawn out at A, after sewing the third section, it is passed between the first and second sections, back of the connecting thread, Fig. 4, the thread drawn: out, the needle passed upward through the loop of thread and the thread drawn down with good tension; but the ends of the sections must not be drawn too tightly together or the middle of the back will appear swollen and will be somewhat inflexible. As the sewing progresses, every time the needle is passed out at A or B, the thread is caught around the thread that connects the preceding sections in the manner just described, before sewing on a new sec- tion. Be careful that the needle does not penetrate the sewing frame cords. As the work advances, the sections should occasionally be pressed together at the points where the cords emerge.

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Popular Science Monthly 291 After a few sections have been sewn to the cords the ends of the sewing thread will be reached and a new length must be added. Tie a sliding knot in the end of the new thread (Fig. 5), slip the loop over the projecting end of the old thread, draw the old thread down through the loop and draw the loops snuggly together to form the knot. After the needle has passed out at the last catch stitch mark A or E as the case may be, the thread should be se- curely connected to the preceding catch stitch thread, so that it will not become untied. The cords may now be untied from the sewing frame and the book removed from it. The cords should be cut about 11% inch from the edge of the book and their ends frayed out flat by scraping them with a knife. Place the thumb and fingers of the left hand upon the back of the book and with the fingers of the right hand, press inward along the frone edge to form the usual rounded shape (Fig. 7). Adjust the press boards so that they will be parallel with the back of the book and at a distance from it slightly greater than the thickness of the mill board to be used for the cover. Lower the book into the press and screw the jaws together just sufficiently to keep the book from slipping through the press. Give the book a final adjustment and screw the jaws of the press tightly together. Now take a ham- mer and hammer tip and down along the edges of the back of the book with diagonal or outwardly inclined strokes, until the ends of the sections spread out- ward over the press boards as shown in Fig. 6. Hammer along the center of the back also, to keep it in well rounded shape. Loosen the jaws of the press slightly and brush hot glue over the back, al- lowing it to penetrate for a short dis- tance between the sections. Tighten the press again, but not so tight as when rounding the back, and having cut a piece of fairly strong cloth to a size about two inches shorter and two inches wider than the back of the book, lay it in place upon the back and press it down firmly upon the fresh glue. When the glue is fairly dry but still flexible, trim the end papers to size and take the book at once to the printer who will rap the book straight from its rounded form, clamp the book in his power cutter and trim its edges. After cutting the edges of the book they may be ornamented by placing the book between the boards in the crafts- man’s press and spattering the edges with red or brown ink. Figs. 4 and 5 The method of sewing Fig 6 Dip a tooth brush in a small saucer of ink, rap off the surplus ink and draw the brush across the coarse teeth of a comb. Practice first on a sheet of waste paper. The book is now ready for the cover. Obtain some mill board of the desired thickness, lay it upon another piece of mill or straw board and using a sharp knife guided by a straight edge, cut the mill board to the proper size. For a book of magazine size, there should be a space of about '4-in. or more between edge of the cover and the back edge of £ a , w Fig. 7 Fig. 8 Shaping the book Forming the covers the book. This space should be greater when using heavy cloth like buckram, than for cloth of light weight. Fold a strip of paper around the back of the book and place the trimmed mill board in position on the book, Fig. 7. Make pencil marks upon this strip of paper close to the edge of the mill board cov- ers. Lay the mill boards upon the table with a space between them equal to that LE

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292 indicated by the marks upon the paper strip and measure the size for the cloth for the cover, which size should be about %4 inch larger all around than the outer measurements of the boards as shown in Fig. 8. Buckram is usually the only cloth suitable for covers that can be found in small cities. It should be of good quality and color. Thin, split leather can be handled the same as cloth. Having cut the cloth for the cover, lay it right-side down upon the table, and upon it lay the cover boards. Care- fully arrange in position with the meas- ured distance between Z them and mark around -7 their edges with a pen- cil, marking upon the buckram. Remove the boards from the cloth. Lay one board upon a piece of waste paper and brush hot glue over it and replace and press it down upon the cloth cover in its final position, glued side down. Turn the cloth cover and the attached board over, spread over them a clean cloth and fin- ish the pressing with a flatiron which should not be too hot. Press around the edges of the board as well as over its face. Proceed in the same way with the other cover-board. Trim the projecting edges of the cloth all around to about 4% or % inch from the boards. Cut the corners from the cloth as indicated by the dotted lines in Fig. 8. Do not cut the corners close to the board but leave about 14 inch of cloth and be careful to make the cuts at an angle of 45 degrees. Brush the glue upon the projecting cloth along the top edge of the cover and fold the cloth over upon the boards. Glue and fold the cloth at the lower edge in the same way. Before folding the cloth at the front edges, fold in a little corner of the corner cloth as along the dotted line Fig. 9. Place the book between its cover and carefully adjust it to its final position. Lightly mark around the four front cor- ners of the leaves of the book, marking the buckram to show where the book should lie within its cover. When all work is finished the marks may be erased, Lay the book upon the table Fig. 9 Popular Science Monthly and open the top cover back upon it as in Fig. 10. Take a sheet of waste paper larger than the book and slip it beneath the end paper to protect the book from glue. Throw the strip of backing cloth and the cords backward and quickly brush the hot glue over the end paper. Fold the cords over upon the end paper, tak- ing care to spread their ends open as shown in the drawing and brush them down into place. Fold over the back- ing cloth and brush glue over it. Pass the smooth handle of the brush up and down over the backing cloth, and along the raised edge at the back to insure its contact with the book at this point. Slip the fingers of the right hand be- neath the front edge of the glued end paper and press down firmly upon the book to keep it from slipping out of place. With the left hand lift the cover, draw it snugly around the back of the book, hold it at an angle to allow room for the right hand and press the cover firmly into contact with the book all along by the back edge or joint. Re- move the right hand from the book and lightly lower the cover upon it. Open the cover and proceed to press the end paper into smooth contact with the board. Upon opening the cover, if it is found that the book has shifted badly from position, it may be well to strip the end paper from the board and try again. This is a risky operation, how- Fig. 10. Completing the process ever. Proceed in like manner with the opposite cover. When the covers are on, the edges of the flatiron or handle of the brush should be passed up and down along the depression at the joints of the book covers and the covers should be carefully opened and closed several times. The covers may be left slightly open while the glue is drying, or if they are closed, sheets of waxed paper or

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Popular Science Monthly 293 celluloid should be placed between them and the end papers to keep the leaves from absorbing moisture and becoming wrinkled. The easiest way to letter the cover of the book is to make a stencil of the paper cover of the magazine, as this will save the labor of laying out the let- ters. Lay the cover paper upon a hot plate and saturate it with paraffine wax. Wipe off the surplus wax while it is still hot. Lay the waxed paper upon a piece of straw board and cut the letters out, stencil fashion, using the sharp blade of a penknife. Use a good water- proof India ink and a stiff brush from which surplus ink has been removed. Draw the brush inward from the edges of the cut out letters. The letters may be finished by filling in the blank spaces with a pen. A Self-Adjusting Sandpaper Block A SANDPAPERING block that au- tomatically adjusts itself to both convex and concave surfaces of any ra- dius is very easily constructed by using a piece of rubber packing for the face and glueing to the back or fabric side wedge-shaped strips of hard wood of the general dimensions shown in the draw- ing. These strips should be about 1-32 inch apart where they fasten to the rub- ber, so that the face will bend easily. The sandpaper is folded over the block in the usual way and with very slight pressure the face will conform to the surface to which it is applied. This sandpapering — block adjusts it- self to any surface on which it is used tord wood A Handy Way to Repair a Tire VERY convenient instrument which may be used to repair punc- tured tires can be made from a common button hook. Straighten or cut off the hook part with a pair of pliers. Saw a slit about 14 inch from the end up the stem of the hook with a hack saw and round off the ends into a fairly sharp point. With a knife cut all the sharp edges from the slit so it will not tear the rubber bands. Make a hook as shown in. draw- With this tool rubber bands can be pushed into a puncture, to make an excellent quick repair ing, and passing the rubber band first through the slit and then over the hook enough times to fill up the hole in the tire, dip the rubber and hook in tire ce- ment and push through hole. Unhook the rubber band and draw out the hook care- fully with a twisting motion so as not to remove the rubber band. Cut off the pro- truding rubber and you will have your puncture repaired in excellent shape. A New Use for Broken Drills and End Mills ROKEN drills and end _ mills should not be thrown away, as they will be found useful if a special socket is to be made for the lathe or miller, when a drill or end mill is to be held. By grinding the tang off, it can be turned around in the socket to ascer- tain if the taper has a bearing the whole length. If a drill or end mill is used without thus changing it, the tang will prevent its being turned around.

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294 Popular Science Monthly A Home-Made Football Inflater VALVE from an old bicycle tire or an inner tube is a very serviceable substitute for the expensive and delicate pumps used to inflate footballs. Cut the metal ring and the rubbed pad from around the valve, and the inflater is ready for use. Insert it into the neck of the foot- ball, attach the outer end of the valve to a bicycle pump, and your football may be quickly inflated. A Dust-Proof Bottle for Acid GLASS spirit lamp makes an excel- lent bottle for keeping small quantities of ni- tric acid, solder- ing spirit or other acid liquids. A glass rod may be left in the lamp and covered with the ground cap as shown in the illustration. The cap usually makes a very good fit, and for many purposes no other stopper is re- quired. When used to contain nitric acid, for testing gold, however, the other device shown may be adopted. A piece of glass rod is drawn out to a rather fine point at one end and passed through a per- forated India rubber cork, which forms an air-tight stopper. A Multiple Punch = a PUNCH for making ——— a number of " __— holes in sheet fibre or metal can be made from a block of steel machined as shown in the accompanying drawing. A punch of this type is intended for work that must be repeated with uni- form results. An Oil Tray Made Without Solder tb trays which ep aaa require no ¢{ soldering may be made from a piece of tin of such _ thickness that it may be readily bent. The tin should be marked off as in the illustration. Bend the sides up on the lines AB and CD; then bend them back to their former place. Do the same with the ends on the lines XY and MN. Take the corner BY and bend along the line RT until the side and end come together and form a square corner, as in lower drawing. Bend the projection up against either the end or side. Do likewise to the remaining corners. Parcel-Carrying Rack for Bicycle HE accom- panying line drawings show a simple pack- age-carrying at- tachment for a bicycle, which can be cheaply and easily made and removed or at- tached simply. The drawings show clearly the method of bending and the dimensions. Make the pocket to suit the handle bar of the bicycle. Switch Detects Bad Ignition T is often a te- dious and troublesome mat- ter to determine which cylinder of a multiplex cylin- der engine is missing explo- sions. A very sim- ple little instru- ment, shown in the accompanying sketch, renders the discovery of the missing cylinder easy. It is simply a switch, to be fastened to the spark plugs in succession.

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RADIO SECTION Devoted to the Encouragement of Amateurs and Experimenters in the Field of Radio Communication Aeroplanes, Wireless and the War By William Dubulier The author of this article is an American radio engineer, who has performed exper- imental work for the United States Government and whose investigations for the British and Russian governments have attracted attention abroad. His wireless apparatus is now used on British military aeroplanes. His article may therefore be considered as an exposition of the subject of radio communication from aeroplanes from first hand knowledge.—Editor. HE art of warfare has been trans- formed by wireless and wireless has in turn been transformed by modern warfare. We can safely say that the one great electrical event of the war is the use of wireless even between trenches, and the directing of artillery fire. While the regular telephone and telegraph are also used, the wires are so frequently broken by shrapnel and shell fire that wireless proves to be the only uniform and trustworthy means of com- munication. The men themselves at night (the only time when they dare leave the trenches) stumble over regu- lar telephone and telegraph wires and break them, and often there is no opportunity to repair the damage. Not only have the Allies tried to get wire- less trench sets, but the Austrians, Ger- mans and other powers as well. The trench set in question is one in which one man and certainly no more than two men are needed to For aeroplane use, the instruments must have a greater range. They vary in power from twenty watts to two kilo- watts, which latter is the power of the instruments now being installed on big aeroplanes made in England and em- ployed not only to signal the hits and misses of heavy artillery, but also to jam the enemy’s stations. In a wireless installation of this aeroplane type, light weight and com- pactness are the most important re- quisites. Let us begin by describing the small installations which require about twenty watts to operate and which are used almost exclusively by the French army for directing artillery fire. In de- signing this instrument old principles were revived—principles quite the same as those in vogue when wireless first came into being. There is a small in- duction coil with a vibrator and a spark gap, and an aerial and ground or counter capacity carry, set up and * connected across operate. The trans- mitting distance the secondary. This e is shown in Figure 1. The efficiency is ANT 7 need not be more ‘ . | ‘ : than five miles. ( } ba greatly increased Such instruments a by connecting the are now being built and supplied. Fig. 1. Wiring diagram of the Rouzet system, showing synchronized revolving i spark gap now being used by English and French governments One type weighs only eight pounds. condenser across the interrupter arid primary as in the Dubilier system in- 295 a EE en en a en

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296 stead of the condenser across the inter- rupter, the former custom. The battery is a small case containing ten, eight am- pere-hour cells of twenty volts, and the secondary is connected with the dis- charge electrode or oscillator mounted on top of a small case within which the ——— || i y Sony = qe

ih Mh Me i Fig. 2. The apparatus in detail. It weighs, complete, about 30 Ibs, for 150 watts, and includes one self-exciting 250 cycle generator with synchronized spark gap, one Dubilier condenser, one transformer in oil, and a loose coupled tuning coil rest of the apparatus is fastened. The os- cillator is mounted outside to take advan- tage of the rush of air in the aeroplane track along, thus cooling it. The aerial and equivalent capacity is connected di- rectly across the spark gap, thus elimin- ating the necessity of tuning by means of a condenser and tuning coil. The arrangement is much the same as that which Hertz and Marconi used in their initial experiments. It will be seen, therefore, that the operating circuit pro- duces a natural wave without the neces- sity of adjustments such as are necessary for most spark transmitters. The primary input is about twenty volts and one-half an ampere. The inter- rupter produces a musical note of about 250 frequencies. The trailing wire, which is used as the aerial, is about 150 feet long, and has a three-pound lead weight attached to it. With this small power we were able to obtain five-tenths of an ampere in the aerial wire circuit, the capacity of which was about 0.00003 m.f. It was found that communication could be effected a distance of fifteen This served the purpose very especially for directing artillery miles. well,

Popular Science Monthly fire. The receiving wireless station was situated about one mile behind the guns. Between the receiving station and the gunners a regular telephone line was set up. The position of the aviator is obvi- ously very perilous. He must be right over the enemy’s trenches if he is to direct every shot of the artillery. When a shot falls short or long or too much to the right or to the left, he flashes the information at once to his station. The next shot follows the course that he in- dicates. This is the most effective elec- trical work which has been done in the war. The aeroplane employed in this dan- gerous service is a two-seater contain- ing a pilot and the observer. The ob- server sends his messages as quickly as he makes his observations. Another set of instruments is used, of 150 watts capacity, the energy being ob- tained from a generator driven by the engine of the aeroplane. Various in- stallations are used of. this capacity, some utilizing direct current and some

LA

Fig. 3. The he. <0 with a small engine for portable use alternating current. The best instru- ment in my opinion is one which has a 250 cycle alternator attached by a belt to the gas engine. This generator is of remarkably light weight and is so con- structed that it is self-exciting. The whole installation, including the genera- tor, a closed core transformer in oil, a key, condensers, loose-coupled tuning coils and hot wire meter weighs com- plete but 27 pounds. How remarkable is this installation may be gathered from the fact that the ordinary machine

Fe Aiteeiihinin nha SAT IA EET LI

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labia Popular Science Monthly 297 weighs between 75 and 100 pounds. An installation which I have been supply- ing the United States Government for aeroplane work, weighs 60 pounds. Yet here we have a complete apparatus weighing but 27 pounds. _ It would be practically impossible for one to build such a set in this country for government use because the govern- ment tests would automatically elimin- ate the instrument itself. For example, the generator if run under ordinary con- ditions in a room would not stand up under fifteen minutes’ continuous use. The United States Government insists on a test of eight hours’ duration in a closed room. The French and English have wisely concluded that since the generators are used in an aeroplane travelling through air at the rate of sixty miles an hour, a cooling effect is obtained which may be utilized and which will simplify the task of the radio designer. This generator seems to work most satisfactorily and ought, it appears, to be employed by our own navy for aeroplane work. On one end of the shaft of the motor is attached a rotary synchronized spark gap. A_ small closed-core transformer mounted in a fibre tank full of oil and generating about 20,000 volts is included in the secondary. The condenser used is of the Dubilier type. This is the standard for aeroplane installations in Europe for the Allies. The condenser is the most important element of the aeroplane wireless in- Fig. 4. The small apparatus used mainly by the French for directing artil- lery over trenches. This apparatus weighs about 12 Ibs. and is capable of utilizing about 40 watts Liga “ ine | Fig. 5. A 750 watt equipment on aeroplane using the resonance alterna- tor of J. Bethenod. This alternator generates an alternating current of 1500 cycles, 750 watts, at a speed of 4500 R.P.M. The outfit consists of a gen- erator, a transformer, oscillating circuit and a system of manipulation. The generator complete weighs but 42 lIbs., and is built for an overload of 20%. It is driven by the motor of the aeroplane. The transformer has a closed core, and is air cooled without magnetic leakage. The oscillating circuit provides for op- erating on a wave length up to 600 m., and is self-excited by a condenser with 0.01 M. F. capacity stallation; for it is obviously impossible to use fragile Leyden jars. The con- denser must be unbreakable, have high efficiency, and occupy very little space. Figure 2 shows such an installation. By means of a small aeroplane aerial it is possible to radiate one ampere with this installation. Communication can be held over distances of fifty miles. The English government is building its own installations along these lines. Duplex Wireless Telegraphy. UPLEX wireless telegraphy, in which two messages are simul- taneously sent in opposite directions between two radio stations, is entirely practical. The system is used between Glace Bay and Clifden, and in the trans-Pacific stations. This arrange- ment makes it possible to handle twice as many radio messages between two stations in a given time.

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Recent Radio Inventions New Patents on Wireless Instruments By A. F. Jackson MONG the most interesting pat- ents of 1915 is No. 1139220, is- sued to E. Raymond-Barker, for a system of radio-telegraphy using two wave-lengths for transmission of a sin- gle message. Instead of sending Morse signals in which the dots and dashes are distinguished by the difference in dura- tion of impulses, this method uses sig- nals all of the same impulse length but distinguishes between dots and dashes by sending each at _ a different wave ate in these circuits oscillations of dif- ferent wave lengths. If it is desired to send a dot the left-hand key is depress- ed; this connects ‘the left-hand arc to the antenna, and waves of a certain length (say 3,000 meters) are radiated. If a dash is to be sent, the right-hand key is pressed for an instant, and for that time the right-hand are is connected to the antenna and allowed to radiate waves of its different wave length (say 4,000 me- ters. Thus combi- nations of dots and frequency. That is _to say, only short signals which cor- “ey respond in length to ordinary Morse dots are sent, but these are emitted at two different wave lengths, one of which is for dots and one for dashes. d indicate 0 =|" 0 | & represents dots and the other dashes. dashes correspond- ing to the letters of the Morse code are transmitted. At the receiving station it is neces- sary to pick up signals on either wave length and to that one WW Figure 1 shows | Fig. 2 shows one the way in which the invention may be applied to a Poulsen transmit- ter. Here the pow- er lines G supply energy to two oscillat- ing arcs, F F, through suitable imped- ances. The central contacts or levers of two telegraph keys A and AZ are con- nected in the shunt oscillating circuits of the two arcs, and serve to con- nect the arcs either to radiating reso- nant circuits C D or to non-radiating resonant circuits Cr Di. Consider- ing the operation: When neither key is depressed both arcs are connected to their non-radiating cir- cuits through contacts H H, and gener- Fig. 1. 77 Fig. 2. 1c Wy dddddddddddddddddddddddddddééédée Raymond-Barker double-wave transmitter C7) Telephonic Receiver for double- wave system 298 way in which this may be done: The receiving antenna Br is connected to two parallel tuned primary circuits, C5 D5, one of which is tuned to the “dot wave” and the other to the “dash wave.” Each primary has coupled to it a tuned secondary C6 which acts upon a tikker detector Pr with telephone P and stopping condenser D6. One telephone is held to each ear of the _ operator and the dots dis- tinguished from the dashes by not- ing which ’phone gives the response. A simpler way of distinguishing the dots and dashes is by adjusting the tikker-interrupter speeds Pp ZZ U1/ 17

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Popular Science Monthly 299 and the condensers D6 so that the sound of the dots is somewhat different from that of the dashes. This gives in effect a two-tone system, and obviously per- mits higher signaling speeds than does the usual dot-and-dash method. In ad- dition to the increase in speed the two- wave lengths feature offers excellent se- curity from interception of the messages by ordinary radio receiving stations. When the signals received are suffi- and cause loss of energy through short- circuited turns; variometers are limited in range of adjustment, and have their total resistance in circuit even at mini- mum inductance; roller arrangements are bulky, and slow in operation. All these difficulties may be overcome by the use of multiple-point switches connected to the turns of the coils, but it would be practically impossible to have a switch- point for each sin- gle turn of a long ciently strong to operate a sensitive relay it is possible by this method to make a siphon re- corder pen-and-ink record correspond- coil. If a saving in the size of the switch is attempt- ed, by making each point cover a num- ber of turns, it is not found possible ing exactly to cable “slip.” If a relay is connected to each side of the receiv- ing system, the two contacts may be used to control a third polarized. re- lay which will re- main in an open neutral position so long as no signals are received, but which, when waves are ar- riving, will close its local circuit and per- mit ‘current to flow in one direction or the other according to whether it is operated by a dot-impulse or a dash- impulse. A siphon recorder in this last- named local circuit will record the sig- nals by a wavy line having a hump above its neutral position along a central line for each dot, and a hump below for each dash. Fig. 3 shows the actual connec- tions of apparatus set up to accomplish this result, and in this diagram the action may easily be traced from the sensitive relays U U, which are connected to the two detectors, to the siphon recorder g. U. S. Patent No. 1127921, issued to G. W. Pickard, is on an important detail of receiving tuning apparatus. Before the adoption of inductance varying ar- rangements similar to that shown in this specification it had been customary to rely upon either sliding contacts, vario- meters or roller inductances for tuning. Each of these methods has disadvan- tages; sliders give poor contact at times, Fig. 3. Relay connections for recorder operation to get sharp enough tuning unless an auxiliary variable inductance or con- denser is used. The plan of wiring shown in Fig. 4 makes it possible to get sin- gle-turn steps of inductance on a long coil by using two small switches. One of these, indicated by S, has taps taken off the body of the coil at each tenth turn. The other, Sz, has its points connected to each of the last ten single turns on the coil. The leads to the coil, A and G, run to the levers of the two switches; and each ter- minal may be connected directly to the tenth turn of the coil by placing its re- spective switch lever on a button marked “O.” This common sero of the two switches seems to be the novel point in A , OO OO) Poe Peon VY Fig. 4. Common zero switches on inductance coil the present patent, and is the artifice by which it is possible to adjust to any in- ductance from zero to full value by steps

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300 of a single turn. Reference to Fig. 4 shows that each step to the left of switch S adds in circuit ten turns of the coil, and that these large jumps of inductance may be filled in by the smaller steps se- cured by moving switch 1 to the right. 4

= || =a a = pt = | "i —_

Fig. 5. Arco and Rendahl high power variometer This switching system has come into wide use within the past few years. One of the difficult problems of radio engineering is the construction of an easily varied inductance capable of car- rying such high currents as are encoun- tered in the oscillation circuits of power- ful transmitting stations. Flat spiral coils have proved useful, but if they are to be used for final adjustment some way is needed to change their induct- ance gradually without interfering with the current through them. 1915 patent No. 1131187, issued to G. von Arco and R. H. Rendahl, shows an interesting way of doing this. Referring to Fig. 5, two sets of flat spiral coils a and b are seen to be mounted in a framework which permits the group a to be moved away from the others by swinging them about the pivots f as an axis. The whole set of coils is connected in serics, with taps taken off at terminals k, <nd the units are carefully insulated from each other. When the moving group is in the posi- tion of closest coupling to the fixed coils the system has its maximum inductance, since the magnetic fields of all the coils

‘Popular Science Monthly are co-operating ; when, however, the 5 coils are swung out into the position in- dicated by the dotted lines at the bottom of Fig. 5, the maximum addition of fields no longer occurs and the induct- ance of the system is very much re- duced. The special advantages of this method of mounting arise from the fact that parts having large differences of po- tential are kept well separated. Al- though the simple two-coil variometer construction used in receiving coils will give an inductance variation as large as 1 to 15 when insulation difficulties are small, in the two coil form as applied to high-powered transmitter the coils have to be kept so far apart that the maxi- mum inductance is only about twice the minimum. With the sub-divided form shown in this patent, however, heavy currents can be carried and yet a con- siderable inductance variation attained. Fig. 6 shows an interference prevent- er arrangement patented in 1915 by T. B. Miller, specification No. 1127368. In the ordinary interference preventer of Fessenden two primary circuits con- nected to the antenna act on two oppos- ing secondaries; one primary is adjusted to receive the desired signals selectively and to impress them upon the detector, while undesired signals are caused to af- fect both branches of the circuit equally and oppositely and so produce no final effect. The circuit of Fig. 6 differs from this earlier arrangement in that a single antenna primary circuit is used with two secondaries and two detectors,

Fig. 6. Interference preventer and the neutralization of interfering sig- nals is accomplished by opposing their effects in the telephone circuits.

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Popular Science Monthly 301 The primary 3 is coupled to secon- daries 4 and 5, with their corresponding detectors 8, 14, and stopping condensers 12, 18, in the usual manner. The leads from the condensers 12, 18, which ordi- narily go direct to telephone receivers, are in this case carried to the two pri- mary windings of a telephone trans- former. These two coils, 10 and 16, op- pose each other’s effects upon the sec- ondary 20, which has in series with it the telephone receivers 21. This trans- former is adjustable, so that either of its primaries may be caused to induce stronger signals in the secondary than will the other. The operation of the device may be considered in connection with a condi- tion assuming simultaneous sending by two wireless stations, one nearby and the other distant. Suppose that with an or- dinary receiver the strong signals from the nearer station practically drown out those coming from a distance, and yet that it is desired to read messages on the weaker waves. With the apparatus of this patent the receiving operator would adjust one of the detectors, say 8, to a sensitive condition in which it would respond well to the weak signals. The other detector, 14, is then adjusted to receive only the strong signals. Thus there are set up telephone currents in primary 10 from both stations, that from the distant one being much weaker than that from the interfering set, and tele- phone currents in the opposite direction in coil 16, these latter being only from the interfering station. Since the sen- sitiveness of detector 14 has been re- duced, the interference currents in 16 will be weaker than those in 10. By loosening the coupling between 10 and 20, the signals from the interfering sta- tion will oppose in their magnetic effects on the secondary, and so produce no re- sponse; if it has not been necessary to weaken the coupling too far, the signals from the distant station should still be heard. Thus, if detector 14 is of the type which requires a certain fairly large cur- rent before it gives any response, and if the difference in signal intensities is not too great, some very advantageous interference reducing effects may be had. , A Cheap Ground Clamp A hose clamp can be purchased at any hardware store at two for five cents and a binding post taken from the zinc side of an old dry battery. A hole is then drilled in the hose clamp and the post soldered fast. Insulators can be made by taking a broomstick, sawed into 4 inch or 5 inch Strain insulator made from a broom stick lengths and having a screw eye put in each end. Baked and thereafter boiled in paraffine these make first-class strain insulators. To prevent splitting, a hole should be drilled in each end a trifle smaller than the screw eye and then filled with glue. The screw eye should have a coarse thread. The tough hard- wood holds the eyes so they will stand a heavy strain. Two coats of black as- phaltum make them resemble hard rubber. Crystal Detector Hints HEN the best results are to be ob- tained, the crystal should be mounted in a fusible alloy. This can be easily made by melting equal parts of ordinary fuse wire and tinfoil and add- ing a little mercury. In selecting pieces of galena the parts that are very shiny and have the most vein will be found to be the most sensi- tive. When breaking galena do not hit the mineral one hard blow: tap it three or four times lightly with a hammer, breaking it into square pieces, and there will be no waste. With silicon or ferron as a mineral, use a gold wire having a sharp point. A fairly heavy pressure may be used, and results in a firmer adjustment. The re- sistance of a crystal is great, and there- fore as small a piece as possible should be used. Different combinations of minerals will often work better than one mineral. Galena and graphite, silicon and graphite, zincite and bornite, or chalcopyrites (perikon), ferron and silicon, and galena and tellurium will all work better in combination than alone.

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Antenna Circuits in Radio Telegraphy By John Vincent N the two earlier articles of this se- ries, the simple relations between ca- pacity, inductance, wavelength and resonant frequency were explained. It was shown that in a closed circuit such as that of Fig. 1, the maximum current would flow when the impedance (or al- ternating current resistance) was made as small as possible. It was also shown that by adjusting the circuit capacity C and inductance L, they could be made to neutralize each other’s effects for the particular frequency of the alternator E, and that when the circuit was in this resonant condition, the current flowing was dependent only upon the voltage generated at E and the resistance R. The relations of induct- If one thinks of capacity as a prop- erty possessed by any pair of conductors separated by an insulator (which is a correct idea), it is easy to see that an antenna has capacity with respect to the earth. As the two plates of a condenser are separated by an insulator and have capacity with respect to each other, so, in the antenna system, the aerial wires and the earth’s surface, (both of which are conductors) are separated by the in- tervening air. The capacity of the aerial system is a definite quantity depending upon the distribution of current in it, and like that of any other condenser may be computed or measured. Inductance is a property of conduct- ors which makes itself known ance and capacity to frequen- Av) cy and wavelength, and those A of voltage and impedance to Cy current, exist in “open” an- tenna circuits such as that of Fig. 2, exactly as in closed circuits like Fig. 1. For most purposes the computations explained in the January ar- ticle will give good results for by the magnetic effects pro- duced upon these conductors when the currents through = them vary. Since direct cur- rent is usually of uniform strength, in direct current circuits inductance is not often considered; neverthe- less, the property is always present and ready to become either open or closed circuits. The only error likely to cause trouble depends upon _ the fact that in the elevated part of an antenna circuit there are both capac- ity and inductance. In the closed cir- cuit (Fig. 1) practically all the capacity is lumped together at C and nearly all the inductance at L. In the antenna, however, for short waves the inductance L may be quite small and so the distrib- uted inductance of the antenna wires may play an important part in determin- ing the resonant frequency of the sys- tem. For most radio telegraphic pur- poses waves considerably longer than the natural wavelength of the aerial are used, and with these the antenna may be considered to be the equivalent of an inductance, a capacity and a resistance all connected in series. Fig, 2 302 | prominent when the current 4- varies. In radio antenna sys- tems, alternating current flows and therefore the inductance of the wires is important. One hundred feet of anten- na wire stretched out straight has about 0.07 millihenry inductance, which is equivalent to about twenty turns of No. 24 wire wound in a coil of 4” diameter. For a given length of wire a coil has much more inductance than a straight wire, because each portion of it can act magnetically on the turns beside it. Thus the inductance of an antenna wire can be represented by that of a small coil, just as its capacity may be represented by that of a condenser. Antenna systems, like other conduct- ors, possess electrical resistance in addi- tion to their capacity and inductance. This resistance is made ap of several

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Popular Science Monthly 303 parts, one being of the wires themselves and another that of the earth’s surface in the neighborhood of the antenna-base. All power losses in the antenna, includ- ing that due to the radiation of energy, represent additional parts of the effective resistance. All these component parts ‘are added together to get the true total antenna resistance. For instance, in a large flat top aerial the wires might rep- resent an effective resistance of 0.3 rapidly, till it teaches a maximum value. If the inductance is still further in- creased, the current will grow smaller and smaller. The largest current flows when the effect of the inductance just neutralizes that of the capacity for the frequency used, or, in other words, when the antenna impedance is a mini- mum. The aerial system reactance is then zero, the impedance is equal simply to the effec- tive ohmic resist- brush discharge 0.2 tenna is resonant or tuned to the al- 4 | 6° Ze ohm, the ground —f WWW ance, and the an- 0.4 ohm, losses by a S y ) : o— ohm, losses at the insulators 0.2 ohm, ternator frequency. and the radiated ower 0.8 ohm. Added _ together, = the total resist- ance becomes 1.9 ohms; a closed circuit having the same capacity and inductance as the an- tenna, and including a resistance of 1.9 ohms in series, would permit the same current to flow as would the aerial when excited by the same frequency and voltage. From the foregoing the fact appears that, for wavelengths long compared to the fundamental or natural wavelength, the electrical properties of an aerial sys- tem are in many ways equivalent to those of a circuit containing lumped in- ductance, capacity and resistance. An experiment with the arrangement of Fig. 3 will show this to be true. In the dia- gram A and G represent antenna and ground, which are connected to the “X” side of a double-throw double-pole switch. The “Y” terminals lead to a condenser Cz, inductance Lz and resist- ance Rr, in series. Across the center points are connected the radio frequency alternator E, the inductance L2, and the ammeter J. Suppose the switch to be closed on the “X” side and the alterna- tor to be generating at 100,000 cycles per second frequency (which corre- sponds to a wavelength of 3,000 meters). Assuming the natural wavelength of the aerial to be considerably under 3,000 me- ters, if the inductance L2 be slowly in- creased the current reading of / will also increase, at first gradually and then | an In this condition the current is de- the total antenna Sle resistance and the effective applied voltage, irrespective of other factors. If, now, the condenser Cr is made equal in value to the capacity of the an- tenna and the coil Lz adjusted to equal the aerial inductance, the right hand cir- cuit will have a reactance equal to that of the antenna. If the switch is thrown to the “Y” position, with the alternator running at 100,000 cycles, and the in- ductance L2 is again gradually increased from zero, the current reading of J will first increase and then decrease exactly as before. The point of maximum cur- rent will appear for the same value of L2 as when the antenna was connected; if the resistance Ri is set to a value equal to the total antenna resistance the greatest current in amperes will be ex- actly the same as with the switch in the “X” position. Thus it is evident that any antenna may be considered as an inductance, a capacity and a resistance in series, and that so far as current and voltage ef- fects are concerned the true aerial cir- cuit may be replaced by an artificial an- tenna consisting of equivalent condenser, coil and rheostat in series. This means that the considerations regarding the impedance of closed oscillation circuits and its arithmetic calculation, as given in the January article, may be applied almost without change to antenna cir- cuits. It is only necessary that the wave- termined only by.

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304 length used be somewhat longer than the fundamental of the aerial, which is the usual condition of practical wireless telegraphy. In all the discussions up to this point the use of sustained or undamped radio frequency current has been assumed. The generators indicated by the symbol E in the diagrams have been supposed to be radio frequency alternators of the Fessenden type, which produce continu- ous alternating current of a definite ra- dio frequency depending only upon the speed of the machine. Such an j\y alternator forces any attached Popular Science Monthly ment of Fig. 4. Here an antenna 4, which possesses inductance, capacity and resistance, has connected between it and the earth — a spark gap S. Across the spark gap, by means of terminals TT, a high voltage transformer, induct- ance coil or other charging source is connected. If the potential of this charging source gradually increases, a current flows into the antenna and, be- cause of its electrostatic capacity, this aerial system takes a charge. If the voltage continues to rise until the elec- trical pressure is so great that the air between the spark gap circuit to oscillate at the ma- chine’s generating frequency, ? terminals at S breaks down, a spark will pass and the elec- but the amount of the current set up in the circuit depends strictly upon the dynamo’s voltage and the circuit’s im- pedance to that frequency. Transmitters of this general type are coming into wider use day by day, as is seen from the work of the Gold- tric charge previously im- pressed upon the aerial will rush to earth. In an ordinary antenna this discharge to earth will be such that the electrical inertia of the system will cause the charge to “over- shoot,” in a sense, and the an- tenna will take on a polarity schmidt, Fessenden and Tele- funken companies. The cir- cuit effects described are - substantially identical with those in alternating current circuits operating at commercial power-distribution fre- quencies of 25 or 60 per second; in the radio work, however, resonant or zero- reactance effects are made useful, and condensers are used directly in the cir- cuits. In low-frequency practice, reso- nance is usually carefully avoided and series condensers are almost never used. By far the greatest number of radio telegraph transmitters in use today are of the spark condenser-discharge type. The circuit behavior in these senders is somewhat different from that in the sus- tained wave alternator transmitters, but most of the basic principies already ex- plained hold true. The main difference arises from the fact that with the alter- nator the frequency of the oscillations developed depends entirely upon the speed of dynamo and is independent of the circuits connected to it, while in the spark transmitter the frequency depends mainly upon the capacity and inductance of the discharging circuit. Consider for a moment the arrange- Fig, 5 opposite to that which it had originally but somewhat weak- er. The insulating properties of the air gap S are not regained in the brief time of the charge’s passage, and so the current rushes up to the antenna once more; at each swing or partial elec- trical oscillation the electromagnetic in- ertia due to inductance causes the effect of “overshooting,” and the oscillations continue until the energy of the original charge is used up. The electrical phe- nomenon is in many ways similar to the mechanical effects which may be ob- served when a weight at the top of a springy rod (which has its lower end clamped in a vise) is swung back and forth. Consider such a mechanical system, as shown in Fig. 5. If the weighted end A is pulled to the right by drawing on the light thread B, the spring C will be more and more strained until at last a point is reached at which the thread snaps. This is a fairly close analogy to the straining of the air in the spark gap S, Fig. 4, as the charging voltage grad- ually increases to the breaking point. Referring again to Fig. 5, as soon as the “charge” of mechanical energy placed in

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a i i i A A Me Popular Science Monthly 305 the spring C is released by the break- ing of the thread, the weight A swings to the left. By reason of its inertia the weight does not stop at the central nor- mal resting position unless the friction is very large, but “overshoots” and trav- els off to the left side. But its motion to the left does not carry it so far from the center as it was originally. When it again swings back to the right the dis- placement is still less ; the successive par- tial mechanical oscillations to right and left gradually become smaller until the energy originally imparted is used up, when the swinging stops. For every complete oscillation of the freely vibrating antenna system a certain definite time is required. This time, which is usually measured in fractions of a second and is called the period of oscillation, depends upon the capacity and inductance of the vibrating system. It is a definite quantity for each amount of capacity and inductance, and, when the resistance is not abnormally high, depends only upon these. If the capac- ity of the circuit is stated in farads and the inductance in henrys, the time of one complete oscillation in seconds may be found by (first) multiplying the capac- ity by the inductance, (second) taking the square root of this product, and (third) multiplying the result by 6.28. Thus if the capacity is 0.002 microfarad (or 0.000000002 farad) and the induct- ance 3.2 millihenrys (or 0.0032 henry), the product is 0.0000000000004, its square root is 0.00000253, and the period (multiplying by 6.28) is about 0.0000161 of asecond. The frequency is obviously the reciprocal of this, or 62,000 periods per second, which (as shown last month) corresponds to a wavelength of 4,800 meters. In the next article some of the effects of changing inductance, capacity and re- sistance in both open and closed circuits will be discussed. ° Edison’s Railroad Wireless IRELESS was used on railroad trains as long ago as 1885, but the system then devised by Edison de- pended upon static induction and not radiated waves. It has been only re- cently that radio telegraphy has proved useful in railroad work. A Roof Insulator a insulator for lead-in wires passing over the edge of a house roof may be made by cutting a piece of stiff asbes- tos and placing it between two pairs of porcelain cleats. A hole is then made in the asbestos and a porcelain tube insert- eo Oa This insulator for lead in wires is efficient and easy to make ed; the entire insulator is then nailed to the roof and is ready for use. The draw- ing shows the construction in detail. International Conference at Washington NTERNATIONAL conferences on radio telegraphy were held at Berlin in 1903 and 1906 and in London in 1912. The next is to be at Washington, D. C. The regulations adopted have been agreed to by most of the countries of the world. Radio Has Velocity of Light N THE experiments between the powerful Navy station at Arling- ton and that of the French government at the Eiffel Tower, Paris, which were carried on two years ago, it was found that the velocity of electromagnetic waves as used in radio was substan- tially identical with the speed of light. The measurements were made by tak- ing carefully timed photographic rec- ords of signals sent across the Atlantic. |

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By John L. EARLY all experimenters are fa- miliar with the action of the ordi- nary inductively coupled receiving tuner illustrated in Fig. 1. With this arrangement of apparatus, if the ele- ments are well designed and manipu- lated, excellent results in tuning may be secured. The construction is not always easy, however, since the primary and secondary coils must usually be so built that one may slide within the other. It is difficult to devise ways to connect con- veniently to various taps on the movable coil without introducing losses in lead wires. Such losses in- variably result in weakened sig- nals, and prevent reception of signals from the greatest possi- ble distances. Fig. 1. i; A Lr w. =e - a mF LO> ca a Magnetic coupling for receiv- ing tuner A somewhat different type of tuner, which is now coming into rather exten- sive use, usually gives sharp tuning and loud signals, yet is very easily assembled. The connections are shown in Fig. 2, and may be seen on examination to bear some resemblance to the inductively coupled layout of Fig. 1. In both dia- grams the antenna and earth are shown by A and E, the primary circuit loading coil by Lz, the primary by L2, the secon- dary by L3, the secondary tuning con- denser by C1, the blocking condenser by C2, the detector by D and the telephone by T. In Fig. 1 the primary and sec- ondary coils are placed rather close to- gether, so that energy may be transfer- red electromagnetically by the action of the lines of magnetic force linking both coils. In Fig. 1, the mutual inductance of the primary and secondary (and there- fore their coupling) is altered by moving the coils toward or away from one an- other; when near together the coupling is close and the selectivity poor, when The Static Coupled Receiving Tuner 306 Hogan, Jr. far apart the coupling is loose and the selectivity or sharpness of tuning great- ’ er. The gain in selectivity is often ac- companied by a reduction in signal strength. In Fig. 2, the primary and secondary coils are set far apart, so that there is practically no magnetic coupling between them. A third condenser, C3, which is preferably variable and of small mini- mum capacity (say of from 0.00005 to 0.001 microfarad range) is put in circuit as shown. This additional condenser goy- erns the coupling of the system; when C3 has small values the coupling is loose and the tuning sharp, and when C3 is increased the opposite condition is ap- proached. The two coils need not be moved at all in order to secure any of the desired coupling effects; therefore, either primary or secondary or both may be variometers and the end-switch losses thereby eliminated. In tuning with the condenser-coupled circuit the ordinary procedure is fol- lowed. The coupling is made close and, with the secondary condenser discon- nected by opening switch S, the primary — is adjusted until the desired station is heard with the greatest loudness. The switch S is then closed and the secondary system tuned by varying L? and Cr. If interference is present, or if the incom- A ing signals are very sharply tuned, the best results are se- cured by gradually loosening the coupling and at the same time adjusting 12 and Cz, to keep the s We mele Mir == (Fig. 2. Static coupling for receiving tuner —a signals at maximum strength. The reso- nant wave length of the coupling circuit L2, C3, L3, is generally much shorter than that which is being received. Test- ing this static-coupled received will be well-spent effort.

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A Mexican Radio Station By Stanley E. Hyde N MEXICO at present there are eight radio stations, situated at Vera Cruz, Campeche, Obispo, Maria Madre Island, Mazatlan, San Jose del Cabo (end of Lower California) Santa Rosa- lia and Guaymas. During the recent troubles in Mexico the rebels destroyed the station on Maria Madre, which is one of a group of three Pacific Coast Antenna wire Tower, Insulator / Insulators Fig. 1. Plan of Antenna Tower, / Courter porse itt oft ground Fig. 2. Plan of counterpoise islands belonging to Mexico, situated about ninety miles southwest of the State of Tepic. These islands, ex- tremely barren and practically void of vegetation, are surely a most uninviting place for a radio operator. The station illustrated is that of the Federal government, completed during the present year at Mazatlan, Sinaloa, the largest Mexican city on the Pacific Coast. The station is on the top of a hill back a little from the city, and over- looks the ocean. On the side of the hill are broken down barbed-wire fences in great confusion, erected by the Federals to hinder the advance of the rebel forces which about a year ago tried to capture Mazatlan by land and sea. Upon reach- ing the station one is greatly surprised to find a modern steel tower tor support- ing the antenna. It is square and grad- ually tapers to the top, on which is an observation platform which can be made useful for military purposes. The whole, constructed of thin structural steel, is 250 feet high, and guyed by steel cables anchored firmly in the earth. The antenna, which is illustrated in Fig. 1, has distinct features not found in the ordinary radio station, and is especially adapted to the tropics where the static is troublesome. It consists of four wires spread out umbrella style, but not connected together at the bot- tom. The four spans are brought to- gether near the top and the leads run down from the highest point, as illus- trated in Fig. 3. On such rocky and dry soil it would be impossible to obtain an efficient earth connection so a counterpoise or artificial serial is made use of. Fig. 2 shows a plan of this, which consists of wires supported 18 feet off the ground and insulated from it. These wires are also connected together at the tower ter- minal and brought into the station through a large lightning switch. The radio building is constructed of , brick and has a red tile roof. Two rooms are used for the transmitting and receiving instruments, whjle the other three are for the use of the operator and his family. The transmitter is a 1% kilowatt Telefunken set, using a 500 cycle alter- nator, belted to a ten horse-power dis- Directly connected to the tillate engine. Fiz. 3. Diagram of station at Mazatlan, Mexico 307

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308 Popular Science Monthly alternator shaft is a small direct current exciter. Engine and alternator are situated in a separate room from the rest of the apparatus. The engine is water- cooled by rain water collected in a large tank outside.. The receiver consists of a Telefunken loosely coupled set with variable condensers, telephones, two sensitive Galena detectors and transfer switch. To the left of the receiver stand a high voltage tube condenser, the quenched, and variometer inductances. A hot-wire ammeter is included in the antenna circuit. It is. remarkable that this small station can work with Vera Cruz, over mountains and dry places, a distance of nearly 800 miles, but strange things hap- pen in the tropics. A Variable Condenser VARIABLE condenser can _ be made of two test tubes covered out- side with tinfoil, one tube being a little smaller in diameter than the other. The smaller tube is placed inside of the large one, a flexible card being attached to the tinfoil on each. The condenser is varied by sliding the smaller tube in and out of the larger. There may be several sets of these condensers made and hooked up in either parallel or series. large tube covered mith foil on outside small tube covered with foil an ovtskde“ A variable condenser made from two test tubes Radio Club News HE Technical Association of Li- censed Operators, was formed on October 21, 1913. Meetings are held fortnightly, at which papers are presented and discussed. The present officers are: W. Woodrow, President; E. T. Dickey, Secretary and Treasurer. Other clubs are invited to address communications to the secretary’s of- fice, 1649 Amsterdam Ave., New York City. Radio Club of Redlands The Radio Club of Redlands, -Calif., was recently formed, with an_ initial membership of nine. The following officers were elected: President and Chief Operator, Ezra Moore; Vice- President, Arthur Munzic; Secretary- Treasurer, Rudolph Kubias, and Asst. Secretary-Treasurer, Harry William- son. Meetings are held every second Friday evening, at 7:30 P. M. Amateurs in nearby towns are re- quested to communicate with the club, at 108 Eleventh Street, Redlands, Cal. Wireless Club in Salt Lake City __ At a recent meeting officers were again elected to positions in the Granite Wire- less Association. The club is beginning its second year in amateur radio work and is now studying some of the latest works on Radio under the supervision of Prof. S. H. Besley. Most of the mem- bers have stations entirely of their own make and have secured excellent results. They hope to have the largest club of the Middle West and invite communica- tions from other clubs. These may be addressed to Pres. Merton Stevenson, Granite High School, Salt Lake City, Utah. The club’s station call is G. W. A. and practice work .is carried on the last Saturday evening in each month. Busi- ness meetings are held every Friday af- ternoon, beginning at 2 P. M. at the school building. Pensacola Junior Radio Club The Junior Radio Club of Pensacola, Fla., recently held its first meeting. The following officers were elected: Edwin Copas, President; Oliver Williams, Sec- retary; Fred Gillmore, Operator. Near- by amateurs are invited to join. Ad- dress communications to Fred Gillmore, 127 W. Gregory Street, Pensacola, Fla.

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What Radio Readers Want to Know Indoor Aerial C. J., Detroit, Mich., asks : Q. 1. Would it be possible to use the light- ing circuits in the house for an aerial, it being understood that the main switch is open? A. 1. While not a very efficient aerial sys- tem it might be used under certain conditions. If the wires are not placed in metal conduits or in no way grounded, the system could be used. Nothing but local stations would prob- ably be received. Better run a few wires across a ceiling in the top of the house than to try to use the light wires. Q. 2. If the wires could be used, what would be the wave length of the system? The house is a two-story frame house, with one light in the attic and four in the cellar. A. 2. It would be impossible for us to estimate the wave-length of the system. Q. 3. If the bulbs were unscrewed, could this aerial be used to transmit on by using a small coil? A. 3. No. The potential from the coil would be too high for the wiring and would puncture it at such points as fixtures. Similar trouble is experienced where currents are induced in the house wiring from an out- door system of aerial conductors. Radio Telephone E. J. O’B., Black River Falls, Wis., asks: Q. 1. Will you please give me the informa- tion which will enable me to construct a radio telephone set capable of transmitting one- half mile or farther if possible? A. 1. We would judge from your letter that you would prefer to have instructions for a set which you could set up yourself, without involving expensive construction costs. For details of larger or more effi- cient sets we would have to refer you to a text book on the subject as it would be far too long to cover in this column. However, there is in vogue a type of radio which will cover the distance which you desire and which is fairly reliable. Such a set consists fundamentally of a transformer, such as would be used for radio telegraphic “work, shunted by a carbon micrometer gap. Con- nected across the gap are two small conden- sers in series between which is the primary of an ordinary oscillation transformer. The secondary of the oscillation transformer is connected on one side to the aerial and on the other to the transmitter, the other side of the transmitter being grounded. The conden- sers are about 0.0025m.f. in capacity and the transformer about % K.W., and should op- erate on 60 cycles or at a higher frequency if available. The April, 1914 Popular Electricity and World’s Advance, page 1,466, has a de- scription of such a set and shows the microm- eter gap in detail, giving the necessary work- ing drawings. Page 666 of the May, 1914, Modern Electrics and Mechanics, describes a similar set, but omits details of the spark gap. Multiple Tuner A. F., Rochester, N. Y., asks: Q. 1. Is it absolutely necessary to use No. 24 wire on the multiple tuner described in the September issue of the World’s Advance? A. 1. By changing the size of the wire the most important change in the characteris- tics of the tuner will be the wave length, to which it will respond. By increasing the size of the wire the wave length to which the tuner would respond would be decreased.. By using smaller wire the respondent wave length would be increased. In this partic- ular tuner it would be possible to use any size of wire from about No. 22 to No. 28, bearing in mind, of course, the change in the respondent wave length. For your purposes we do not believe this change would be of any great importance to you. Q. 2. Is it also necessary to use enameled wire? A, 2. Enameled wire permits the greatest number of turns to be placed on the coil and increases the respondent wave-length over that available with other types of windings. Spaced bare wire or single cotton or silk covered wire may be used quite satisfactorily. Receiving Set E. E. Z., Long Island City, N. Y., asks: Q. 1. Please give me the dimensions of a receiving transformer to use with an audion detector to have a range of 200 to 1,500 meters. I desire to use switches instead of sliders. A. 1. Wind 150 turns of No. 28 S. C. C. magnet wire on cylinders 5% and 4% inches in diameter respectively and five inches long. You can arrange the taps to suit yourself. On the primary we would suggest that you make arrangements for tuning to every other turn, and on the secondary ten points wouid be sufficient. Q. 2. Please give me the dimensions of a loading coil to increase the range to 4,000 or 5,000 meters. A. 2. Wind No. 28 S. C. C magnet wire 309

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310 on a cylinder 5% inches in diameter and 15 inches long. You should place about 500 turns on this coil. A. 3. What is the approximate capacity of a 17 plate rotary condenser whose plates are 4% inches in diameter and a separation of about 1-16 inch? A. 3. We assume by a 17 plate condenser you mean 17 rotary plates. This condenser would have a capacity on the order of 0.0008 m.f. Receiving Distance B. R. J., Omak Wash., asks: Q. 1. I have a circuit of No. 14 copper wire, 475 feet long, strung from comb to comb of buildings. I wish to use this as an aerial by placing a gas pipe in the center of the span, raising it to 92 feet above the ground. Using silicon or other crystal detector, what is the prospect of getting at least time sig- nals from Mare Island Navy Yard, 800 miles south of here or from Bremerton, about 140 miles west of here. I am located east of the Cascade mountains in the Okanogan Valley of Washington. A. 1. It is very difficult to say just what a station will do when the station is located behind a mountain range, but if you use an efficient set we do not see why signals should not be received from Mare Island. If you used galena instead of silicon you would probably have better luck. Be sure to insulate your antenna well from the gas pipe pole. This will prevent serious difficulties. Armstrong Circuit F, F. L., New Rochelle, N. Y., asks: Q. 1. Can the Armstrong circuit be used on wave lengths of from 150 to 3,000 meters? If so what size coils should be used? A. 1. The circuit itself is all right, but it is very difficult, if not impossible to get the audion to oscillate satisfactorily in a wave length of 150 meters. It is possible to get it to work on the longer wave length you men- tion. As the sustained waves are almost by absolute necessity of a long wave length there is very little need to get the audion to respond to the shorter lengths, as it is fully as effec- tive to receive there the spark frequency ra- ther than the radio frequency. Single Radio Receiving Station C. O. T., Easton, Md., asks: Q. 1. What instruments do I need to re- ceive messages 500 miles? A. 1. Some form of tuning coil, preferably a loose coupler, many of which have been de- scribed in the columns of this publication; a detector, a mineral such as galena would - than is possible for us to do here. Popular Science Monthly probably be most satisfactory to start with; a high resistance receiver, a 2,000 ohm set is quite satisfactory, and a small stoppage con- denser is all that you would require. Better results would be obtained by adding a vari- able condenser across the secondary of the loose coupler, but this is not absolutely nec- essary. Q. 2. What kind of an aerial would you use? A. 2. The easiest to erect, is about the usual answer. Almost anything will do. Look around and see a few other aerials and you will get a good idea of what you think would best suit your needs. We would suggest that you buy, if not otherwise possible to obtain, a copy of Edleman’s book on “Experimental Wireless Stations.” This book will answer both questions 1 and 2 with far more detail It will also give you a very good elementary knowl- edge of the entire subject. Q. 3. We have a 32-volt storage battery house lighting system for house lighting. Can | use this on my receiving set? A. 3. No battery is required for your re- ceiving set. Loose Coupler J. F. E., Pittsburgh, Pa., asks: Q. 1. Is it necessary for me to build two loose couplers in order to receive wave lengths of 150 meters up to 3,000 meters, or would one loose coupler be sufficient without bothering with the dead end effect? A. 1, Unless you desire the highest possible efficiency, one loose coupler will be sufficient for your needs. The amount of dead end ef- fect will be small and will not cause a great deal of loss. If so desired you could section- alize the coils by inserting one or more switches, but we would not consider this abso- lutely necessary. Unless you have a very small antenna it will not be possible for you to receive wave lengths as low as 150 meters without inserting a condenser between the aerial and the primary of your loose coupler. If you desire to receive wave lengths of 150 meters, your aerial including all leads should not have a total length of over 50 feet. Sat- isfactory operation may be obtained from aerials whose total length is 125 or possibly 150 feet if the series condenser above referred to is used. Q. 2. What number wire should I use to build a loose coupler which will tune to 3,000 meters? A. 2 Wind the primary with No. 24 S. C. C. magnet wire, and the secondary with No. 26. The primary cylinder should be 5% inches in diameter and the secondary 4% inches. Both cylinders are 7 inches long.

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The Home Workbench Avoiding Dangerous Stair Turns HE turn of an ordinary narrow staircase is so sharp and the steps at the inner part of the turn so nar- row that a person in a hurry is likely to stumble and fall. The danger of injury can be considerably reduced by construcing the stairs with the steps The usual way of building stairs(Fig. A), and the more intelligent scheme of widen- ing the inside steps at the turn (Fig. B) wider at the inside of the turn. To ac- complish this, more steps must be allowed for making the turn. Instead of the usual sharp right an- gle, each succeeding step should be cut at an increasing angle, so that double the number of steps are re- quired in constructing the turn. By a comparison of the two drawings, it is readily seen that the breadth of the step on the inside of the turn meant comfort and safety in a narrow passage. A Dustless Ash Sifter HAT unhappy Saturday morning task of the small boy—sifting ashes—may be brightened to some ex- tent by a comparatively dustless ash sifter. Certainly, a device of this sort will be welcomed by the housewife, 311 who listens with consternation to the grating sound of the ash-sifter, fully aware of the disaster that powdered ashes wreak on lace window curtains and polished wood work and furniture. The dustless ash sifter consists of two boxes, one for sifting the ashes, the other for receiving the waste. The lower box is large, and fitted with a sliding door at one end for removing the ashes when it is filled. The upper box is nailed over a long hole in the top of the other, and is provided with a hinged cover. At one end of the small box a hole is cut to admit the handle of the sifter. The sifter, itself, consists of a flat wooden frame, made box shaped, from four narrow boards. It is open at the top and screened at the bottom. ‘The ashes are placed in the sifter, the hinged top is closed, and the handle is moved back and forth. Unusable ashes fall into the bin below; clinkers and unburned coal remain on _ the screen. A packing box, properly adapted, becomes an excellent dustless ash sifter

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312 Popular Science Monthly An Outdoor Window Bed. CLEVER Los Angeles club- woman has invented a window bed which can be used for several pur- poses. It may be used, for instance, as an attachment on a window, whereby a fresh air lover can sleep with his or her head out in the open (Fig. 1). The head is protected from mosquitoes in summer by a metal screen box fitting tightly over the head of the bed. By making a few changes in the framework, floored tent or movable playhouse for children is erected. This can also be made 7 feet tall for adults, merely by extending the metal posts. Figure 2 shows how the device can be converted into a flower stand out- eeesee seeees » e . * - = Fig. 1. Outdoor sleeping becomes simple without a sleeping porch Fig. 2. In summer the arrangement can be used as a flower pot support \ pio “ Fig. 3. How the arrangement becomes a plain bed Fig. 4. The same piece of mechanism made into portable two-shelf flower stand side the window and a table inside the window. In Figure 3 it is a plain bed. There are many further possibilities of this versatile bed as an elevated platform for travelling speakers, as a children’s theatre stage, as a display stand for itinerant peddlers, and patent medicine men. For further outdoor uses it can be transformed in a few minutes to a portable two-shelf flower-stand (Fig. 4), or a lawn settee. For the Amateur Painter HEN painting sash-windows it is very hard not to get any paint on the glass. Any attempt to wipe off the paint from the glass means wiping paint from the freshly-coated sash, too. To remedy this take a cake of soft soap and rub it on the glass close to the sash, making a 2” margin. The sash can then be painted without being careful about the glass. When the paint is dry wipe the soap from the glass and the paint will come off the glass, too.

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Nay A srt ma How to Make a Simple, Automatic Window Closing Device HE object of this device is to en- 1 able one to sleep in a room with the windows open during cold weather without the disadvantage of having a cold room in the morning. Briefly, it consists of an electro-magnetic latch which holds the window open during the night until at some predetermined hour, early in the morning, an alarm clock ope- rates a switch in the latch circuit which releases the latch and allows the win- dow to close. .The operation of this latch is as fol- lows: When a current passes through the magnet winding (Fig. 1) the arma- ture is drawn in toward the magnet which releases the hook. As the hook falls, the window no longer being sup- ported, closes. It is, of course, neces- sary to fasten a weight to the window, or remove the window weights, so that when it is not supported by the hook it will close because of its weight. When the window is closed the hook remains in the position shown in dotted lines in Fig. 1. As soon as the current ceases to flow through the magnet winding, a spring (not in the drawing) moves the armature back to its original position. When the window is again raised the top of the ring striking against the hook carries it up with it until the hook au- tomatically locks into position. The window will then remain open until a current again passes through the mag- net winding. The construction is as follows: The yoke piece may be cut out of a piece of iron or cold rolled steel 214” x 144” x 4%”. Two pole cores of the same material about 34” in diameter are’ riveted to this yoke piece as shown in the drawing. The magnet spools may Press-button,. l} Lotch | ! Clock Bottery Fig. 2. Diagram of connections be formed out of brass, or some insulat- ing material, and wound with No. 20 B. & S. gauge single cotton covered wire. About 5 oz. of this wire will be re- Uy Y///: yy Ml — Window frome ‘base AGUSTING Stren Vohe-- 7 be “Armature ib Hook / Window sash Fig. 1. The latch, showing its operation quired. The armature should be cut out of a piece of 1/16” sheet iron and bent up at the top to form a bearing and at the bottom to form a support for the hook. The base, the hook, and the ring should be cut out of 44” sheet brass. A spring must be provided to keep the ar- mature over against the adjusting screw when the magnet is not energized. A suitable spring for this purpose may be formed by winding No. 23 B. & S. gauge phosphor-bronze wire on a rod 3/16” in diameter. This spring may be supported on a rod between the two magnet spools. This spring support rod should be just long enough to keep the armature from coming into contact with the pole core ends when the magnet is energized. For operating this device use an ordi- nary alarm clock, the only requirement being that it shall have an alarm winding key which rotates as the alarm rings. 313 a eee eae —

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Popular Science Monthly tr 5 ta ree ; ia é¢ Washer Joring support ~ xe ‘— tr Ea x Winding Spool i vty i +t ce +—s—¥ || ae L.-J y fe Magne? nat mo, Sa ohe | 4d Aqusting — is : ia i Q) siren sipport le % ; eM ec ed ee oa Sh ett > pe gt ioe =" | Ai ©) ‘ute 0: fol — \ ft | oy? ___ f el a- — 2g - : P | 6)-| ee |}] Adisting screw te % oy Il N 7 ; “g t At H al sa y4 . Base Armoture Details of construction of window opening device Two binding-posts are fastened to the back of the clock. One post is in elec- trical contact with the frame of the clock while the other is carefully insulated from it. A flat spring is attached to the insulated binding-post and bent into such a position that the alarm key will come into contact with it as it rotates. It is not necessary to wind the alarm up com- pletely but only to give it a fraction of a turn so that in unwinding it will touch the flat spring in passing. The apparatus should bé connected up as shown in Fig. 2. One dry cell is suf- ficient to operate this device. A press button switch may be included in the cir- cuit as shown in Fig. 2. This press- button is for use when it is desired to close the window at any time other than that for which the alarm clock switch is set. , One alarm clock switch may be used to close any number of windows at the same time by simply connecting the magnetic latches on the different win- dows in series. It will, of course, be necessary to increase the number of cells in the battery if more than one window is to be operated. For Conserving Heat in Steam Pipes, A N excellent covering for steam pipes may be made from materials that are almost always available. Take some fine sawdust and screen it through a sieve to remove any foreign bodies. Prepare a thin paste of flour and water, and mix the sawdust thoroughly with this paste. With a small trowel, the mix- ture so prepared should be applied in about 5 coats to the steam pipes while they are slightly warm. Each coat should be thoroughly dry before the next is ap- plied. If the steam pipes are in an ex- posed situation, 3 or 4 coats of coal-tar should be applied after the paste has dried; if inside a building, this water- proofing is unnecessary. Steam pipes treated with the sawdust as above lose very little heat and, in addition, the mix- ture is much cheaper than patented prep- arations.

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Popular Science Monthly 315 How to Make a Snow-plow to Clean the Sidewalk HE plow is built on a lawn mower, the blades of which have been re- moved. In the drawing the plow is made from a shovel. One of the halves is put on each side and brought to a point in front. The frame is made of one board about 1” x 12” or two boards 1” x 6”. This snow-plow is made from a lawn mower from which the blades have been removed As the sizes of lawn mowers vary, so will the plow have to vary to fit. The cross-bar is the width and thickness of the handle of the mower, and can be ad- justed. It keeps the nose of the plow on the ground. A Clock Light for Dark Mornings BOY of fourteen, who has had no instruction in electricity, and whose home in a little Iowa town has no electric service, invented the device illustrated. In this home, early rising is the rule, partly from necessity and partly from choice. In the winter time, when the days are short, he must rise before there is much daylight. This arrangement enables his father or WALL Li6HT AND SocKer 41D OF DESK When the lid is lowered the switch automatic- ally closes the circuit and lights the desk lamp mother to illuminate the dial of a clock and to see what time it is without get- ting up. As the diagram shows, two dry bat- teries are connected in series and put into a little wooden box, on top of which the clock rests. To the back of the box is fastened a light bracket made of strips of soft wood. This bracket overhangs the clock, and to its underside is fastened a three-volt searchlight bulb in a minature base. From one pole of the battery a wire is run down behind the dresser, under the carpet to the bed, up one of the bedposts, to a height about a foot above the mattress. Here a push-button is attached. The return wire goes back over the same route, up behind the dress- er to the lamp, and from the lamp to the other pole of the battery. Hanging in front of the lamp is a little piece of tin bent so as to make a crude reflector, at ! _— Ss, Push Buton i ii i! hy \\ | A push button beside the bed allows the boy to see what time it is without getting up the same time that it serves to keep the light of the lamp out of the observers’ eyes. By pushing the button the dial is illuminated, and the occupant of the bed can read the time without rising. An Automatic Desk Lamp CONVENIENT automatic desk light may be easily constructed from two pieces of thin brass, a small light bulb with socket, and a dry battery. A piece of brass is screwed to the desk lid, as shown, and the other piece is fast- ened underneath it, so that when the lid - is lowered the two pieces close the cir- cuit to light the lamp. A switch may be placed in circuit so that the lid may be lowered without lighting the lamp. The-wires are placed as illustrated.

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316 Making Use of Cupboard Space for Refrigerator HE location of a refrigerator in a certain home was an afterthought. No convenient space was available—ap- parently. The housewife tackled the problem and finally had a bright idea. There was a large cupboard built into the wall separating the kitchen from a small rear vestibule. It had large draw- ers beneath and shelves closed by doors above. She measured the space occupied by _——— i, | NNSA RASS TSW YW REAR VESTIBULE RIFRIGERATOR == . . Room for a built-in refrigerator should be found where a door for outside icing can be ar- ranged. This pre- vents mud being tracked over the kitchen floor KITCHEN the drawers, and she and her son divided up the list of dealers in refrigerators, spending each half day in the search of an ice box to fit into the drawer space. Persistence was rewarded at last. A carpenter was hired to remove the drawers, cut the wall, and install the re- frigerator, which was chosen with a rear icing door. The doors were also re- moved from the upper part of the cup- board and the shelves, now open are used for staple groceries. The location of the icebox is conven- ient in its relationship to the other work- ing equipment of the room. The iceman can fill the box without tracking mud over the kitchen floor. If the family is Popular Science Monthly away the two inner doors of the vesti- bule can be locked and the outer left open for the delivery. During the late fall and the winter the icing door is left open and the refrigerator keeps food well without ice, which would not be possible were the box entirely within the warm room. Fastening Wood With Screws HEN the wood screw is used for fastening wood together, its func- tions are, firstly, to draw the pieces into close contact, and secondly, to hold them firmly. Driving a screw, as illustrated, is one of the simplest processes in wood- working, but until experience has taught the amateur better, he usually tries to force the screw through piece 1 by main strength or bores a hole so small that the screw must be turned in with a screw driver. In neither case will the screw draw the pieces more closely to- gether than when the screw entered piece 2. The hole at a should be large enough to allow the thread and the shank to be pushed through with the fingers, but not: so large that the head of the screw will not have a good bearing at d. It is not customary to countersink the screw hole in soft wood as at b, or to bore a hole in piece 2 to receive the thread as at c, as the screw head can usually be turned into the wood by the drawing of the thread in 2, until its head is sunk a little below the surface of 1 as at d. In hard wood the hole in piece 1 should be countersunk as shown, and a hole about the size of the core of the thread bored at c, ir piece 2; if this is not done the screw may be twisted off The correct way to use wood screws

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Popular Science Monthly by the force applied to the screw driver, though if the screw is lubricated by be- ing pushed into a piece of yellow soap it may be driven more easily; this is often necessary even if hole c has been bored. To Make a Mission Screen LL the tools necessary for making a screen are a hammer, a few fine nails, a saw, plane, gimlet, rule and glue pot. The necessary material may be found at most sash and door factories or plan- ing mills free of cost. They are: Four pieces like A, 2 like B and 6 like C in 1” boards. If possible obtain pieces of the same wood, ash or elm being preferred. If no work bench is available, nail a ¥%" piece to the floor and by using this to keep the stick from sliding, plane sides smooth and sandpaper. Then take two pieces of A and the two B’s and at a and b bore holes for the casters. Cut in all the A’s and B’s YZ” cuts at m,n, p, q. Then with knife or chisel break out the pieces and square the holes. Cut out the pieces in the C’s at r and s, and smooth the openings. Next procure 2 pairs of suitable hinges and fasten one pair on each of the A’s which have not the caster holes. Place the hinges on the face shown in the cut. When this is done, varnish or stain all the pieces thoroughly. When the stain has dried, the pieces are ready to assemble. Take 4 of the C’s and 4 of the A’s and glue firmly; a few fine nails may be used, care being taken that the wood does not split. Then assemble the 2 B’s and the remaining C’s. When glue has set, put up the frame, put in the castors and stain or varnish again. When this is dry, a suitable cloth may be attached to this frame. This screen is cheaply made and if carefully built will serve the purpose of an expensive screen. One thing in which care must be taken

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Construction details of mission screen

A mission screen easy to make is the hinges, which must be on opposite sides, so that the screen when open must form a Z. Seam Ripper from Old Safety Blade HANDY device for the housewife may be made from a safety razor blade. Cut a wooden handle 5 inches long. Bore holes to conform to the holes in the blade. Two screws, passed through the blade and the wooden handle will hold the blade firmly. This device will be found exceedingly useful to rip the seams in cloth while sewing. To Open a Molasses Jar "Eo remove the top of a honey or mo- lasses can which sticks, the follow- ing will be found practical: Take a piece of stiff wire and bend it into a cir- cle the size of the top. Put this around the top, and with pincers, twist till tight. A Simple Ruby Light F a 220-volt carbon lamp of 32 can- dle-power is used in place of the ordinary 110-volt lamp, a dim ruby light will be obtained which wili not injure negatives exposed to it in the dark-room.

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ad A Combined Ice Storage Room N arrangement of a cold storage room for keeping milk, butter, eggs, fresh meats and small fruits in combination with an ice-house seems to meet the requirements of many country houses. Where perishable ar- ticles are purchased or obtained else- where in quantities, there is felt a need for some cold storage place other than the ordinary ice-box, which after all, is intended chiefly for articles in use from day to day and is rarely of suffi- cient size to accommodate large quanti- ties of food. The ice-house must necessarily be filled in winter, and the trick of using the chilled air from the ice-chamber to keep a storage-room below cool through the summer is an economical one, for there is no great waste of ice. Ice is a cheap commodity ‘in winter, but rather an expensive luxury in sum- mer. Its waste in hot weather in tak- ing it from the ice-house to the kitchen almost daily represents about thirty per cent of the whole harvest. The daily opening of the ice-house, which admits warm air, causes a rapid shrink- age of the supply. The combination ice-house and cold- storage room eliminates, to a certain extent, this daily waste. Most of the articles kept in the kitchen ice-box can be retained in the cold-storage room until actually needed. Consequently, there is less transportation of ice to the house than by the old method. So far as possible this combination house should be located as near the back of the kitchen as conditions will permit, for if made easy of access, it will be utilized to its full extent both summer and winter. As the storage- house is a few feet underground, easy steps must be built to reach it, and not steep, narrow or awkward steps. The ice compartment of the house is filled at the back so that as little muss as possible is created either in putting in or taking out ice. The cost of building a combination 318 House and Cold ice-house and cold-storage room is one- third to one-half greater than that for a simple, old-fashioned ice-house, but in the end the extra investment is well paid for both in the convenience and greater saving of ice. There is another saving that is even more important. Many people living in country houses could reduce the cost of living by buy- ing perishable articles in wholesale quantities, but through lack of proper storage facilities they cannot do so. Butter purchased by the tub or firkin in the season when prices are the low- est would alone represent a big saving. Meats can also be made a big item of saving by buying in quantities, not to speak of small fruits in their season. With an ample cold-storage room, such as that illustrated, one could buy nearly all perishable articles by the wholesale and be sure not to waste any through deterioration. The saving in this way alone would more than pay for the extra cost in one year. The foundation of the combination house may be built of rough stones up to the ground level, cemented firmly together, and lined on the inside with a coating of good concrete. All parts of the house below the grade should be waterproofed in order to keep the moisture out. This is very important, for it is quite essential that the storage room should be dry as well as cold. In the center of the cold-storage room there should be an iron or wood- en pillar to support the load of ice overhead. Likewise, the floor girders above should be extra heavy to sup- port the tons of ice. The outside walls of the ice-house can be built of brick or stone, or even of wood, according to the style of the house with which it is connected. If wood is used the upright supporting-beams must be ex- tra heavy—four by six at least—so that they will be strong enough to carry the load of ice. Ordinarily, the ice is carried on the ground, and the con- struction of the ice-house may be made

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Popular Science Monthly very light, but in this case the ice is above, and the load is considerable. Another point that requires special emphasis is the necessity of building a water-tight flooring for the ice above. Otherwise the water dripping from the ice: will leak through the ceiling and spoil the storage room. Also the ice must not rest directly on this flooring; otherwise heavy cakes when put in will destroy the waterproof lining. A plat- form is made of unmatched boards, supported on short joists laid on edge and nailed rigid with strips of wood. This platform should be strong 319 is merely a matter of individual choice, although most of the big commercial ice companies still stick to the sawdust filling as the most satisfactory method of insulation. Your storage room is thus inclosed on all four sides, and at the bottom with double walls either filled with sawdust or dead air, and with an un- insulated ceiling above. The chilling of the room from above is satisfactory, for the hot air naturally ascends, and the cold air descends. Of course, this produces a certain amount of waste —— 30'-0 — -——_—_. __—— and steady, but it must be ar- ranged so that one can get un- der it easily when the ice is out. It will be necessary every au- tumn before putting in a fresh crop of ice, to clean the space underneath, examine the drain- age-pipe, and look for leaks in the waterproof floor. A good method to make this floor of the ice compartment wa- tertight is to lay down rubber Vedat | | in sheeting, and then nail zinc sheets down over it. The rubber strips make the joints watertight. The flooring must have a gradual slope toward the drainage pipe, which should be at one or more corners of the build- ing. The laying of this waterproof flooring, and the installation of the drainage pipe are the most technical parts of the construction, for on their success depends the serviceableness of the storage room. There is no sawdust or inclosed air space between the ice-chamber and the top of the storage room. This permits the chill from the ice to penetrate downward and keep the room below cold. As the lower part of the room is underground there will be little chance for the temperature to rise in sum- mer. The bottom and sides of the storage room, on the other hand, are well insulated either with sawdust or air spaces. One can take his choice in regard to filling the air spaces. Some find spaces of dead air between the walls just as satisfactory as layers of sawdust or any other filling. That storage plant in the ice, but far less than. one would imagine. When the room is once chilled the change in temperature is very slight. Little or no warm air can come up from the ground or through the sides, except through the window and the door. To make the storage room service- able it needs at least one or two win- . dows on the side opposite the door, but these windows are double and have two sashes, which can be darkened at will with heavy shades. Between the double windows there is a dead air space, which forms a pretty good in- sulation against the outside air. The window can be opened on cold days just enough to get ventilation. Fur- ther ventilation is obtained by tubes that run through the walls on opposite sides. These ventilating pipes should be of a kind that can be closed from the inside at will, so that too much air may not be admitted. This can be arranged very easily by having a cover to fit in the mouth

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320 | Popular Science Monthly of each pipe, so that it can be removed and easily cleansed at any time. The entrance is through a double door. This is better arranged with an outside door opening outward and the inner door opening inward. A vesti- bule of a few feet between these doors is a great convenience and very eco- nomical. Ona very warm day in sum- mer one can then enter the vestibule and close the door behind him before opening the inside one. There is then no rush of hot air from the outside to raise the temperature of the room, an important consideration where one must enter the storage room several times a day. The mere admission of a current of warm air on a hot day may raise the temperature of the room several degrees, and cause the melting of a ton of ice in the course of the season. The compartment above, in which the ice is stored is not very different from the inside of the ordinary ice-house. The ice must be packed economically and in regular layer fashion, and then covered with saw dust. There should be a ventilator in the roof. This is essential to the preservation and sweetness of the ice below. The filling door should be placed as high up un-_=**°* der the eaves as possible, but not so high that there is no room for a block and tackle arrangement. This will facilitiate the handling of the ice enormously, and al- most save the cost of one man in filling it. With the house once constructed it is merely a matter of individual taste in dividing the storage room into com- partments for keeping milk, butter, eggs, meats and small fruits. Any con- venience of tables, shelves and bins that suggests itself can be installed later. The floor of this storage room is of cement, so that the spilling of any liquids will not cause damage. To keep the floor clean and sweet an oc- casional flushing with a hose will suf- fice. The drain for it should be at one side to permit the water to pass off quickly. But as a rule the room should WINDOW be kept as dry as possible, since flushing the floor with water may cause an ex- cess of dampness that will take days to evaporate. ; The economy and convenience of such a combination house can readily be seen from the illustration. I¢e for the house can be taken out from the back in the ordinary way, and that re- maining in the compartment will be utilized at all hours for chilling the storage room below. There will be a little waste through melting in hot wea- ther, but not to any extent. To offset this an extra ton of ice should be placed in the compartment each winter, and then the supply will last through the summer. A combination ice and storage house of this character can be built from VENTILATOR sae Seat 1. oe o.0. AIR SPACE ©. 2°.” et ee Ue ie ee he | ee ss ‘SK -- A . eee oe e °°. o oto, Je Pee a Ome an YY Amit. pats. .* . Ce eee Kis 2 “Bete ae ee” 6 PAW OUST i.e ig . BRICK AKOKS FO" BEAMS # LALLY COLUMN THE COLD STORAGE ROOM CROSS SECTION LONGEST . PART oouBLe. DOOR aE tio Aa STONE CONCRETE Section of ice-house and cold storage plant, indicating construction of floors and walls $500 upward, depending upon the size, cost of materials and of labor. A good size is 25’ square, outside measure- ments, which will give a storage room of at least 20’. If properly built and filled with ice, a temperature of 34° can be maintained in winter, and from 35° to 36° in summer, which is suitable for the preservation of practically all food products. RY batteries can be brought back to their electrical life for a time by punching holes in the zinc covering af- ter having removed the cardboard filler, and soaking them in warm salt water.

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bow” Our Readers’ Service Department Since our editorial pages must be kept free from advertising matter of any kind, we can- not mention manufacturers’ names, trade- marks and the like. But if you want to know more about some simple tool or appliance which you can use in the shop or the home and which was described or illustrated in the PopuLaR ScIENCE MONTHLY, tf you want to know who can supply more information on a subject which has been discussed in our pages, write to our Readers’ Service Depart- ment. Of the two hundred articles and three hundred pictures published each month by the PopuLAR SCIENCE Monrtuyy, there must be many that. interest you in a personal way. Even if the subject in which you are inter- ested has not been taken up in the PopuLar ScieNcE Mownrtuty, the Readers’ Service Department will help you, either by giving you the actual information which you want or by telling you from whom it can be. ob- tained. 321

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Forts on Rails to Travel Along Our Defenseless Coasts A New York inventor, Lawrence Luellen, proposes the mounting of heavy guns on rails, to be run between concrete emplacements at suitable points. General Crozier, the foremost ordnance expert of the United States Army, has thought well enough of the proposal to sketch mountings for the guns. The guns can be quickly mobilized and used wherever an attack is threatened or actually begun. Any desired number of guns can be concentrated at a single spot—something which is not possible with permanent fortifications 322