"SAY, Peter, have you heard anything recently about old Mr. Farwell?” Martha Nixon asked her husband one evening at the dinner table. “You mean that old chap, with all the money, who lives over on Oak Street? No, I haven’t heard anything about him. Why, what’s up?
Loyalty is a common attribute of pipe smokers. But the loyalty of Mr. N. SadlierBrown, a resident of British Columbia, is of a kind and degree that would make any manufacturer feel proud of his product. Here is Mr. Sadlier-Brown’s letter: Blue River British Columbia November 26, 1931 Larus & Bro. Co.
Booklets, Samples, Information, Available To Popular Science Readers
By referring to the advertisements on the pages indicated be low, you can solve a great many problems. Most of the adver tisers in Popular Science Monthly offer valuable catalogues of tools, or booklets of information and instruction. Others will send you samples of products ranging all the way from shaving cream, to glue, and tobacco.
POPULAR SCIENCE M 0 N T II L Y guarantees every article of merchandise adver tised in its columns. Readers who buy products advertised in POPULAR SCIENCE M 0 N T II L y may expect theni to give absolute satisfaction under normal and proper use. Tools, Radio Apparatus, and Oil Burners advertised in Pop ULAR SCIENCE MONTHLY have been tested or investigated by the Popular •Science Institute of Standards and each advertise mnent carries the insignia indi cating approval.
IF YOU could build a perfectly heatproof house like a giant thermos bottle, you could heat it through a hard winter for little more than a few cents a day. And in the summer, the rooms in your house would be as cool as a shaded dell in the woods. Unfortunately, it is not practical to Construct buildings along thermos-bottle lines.
For 7 Years, He’s Glad to State, We’ve Kept His Radio Up-to-Date
No Fiction for Him in This Magazine
This Radio Ham Wants Big Department
Biotropy for Evolution Gains a Supporter
That Twenty-five-mile Visible Airplane Is 420 Feet Up
Incinerate the Rats and Set Idle Men to Work
Television Is Derided as Most Improper Word
Everything Just Right for This Constant Reader
All the World Was Small in Those Queer, Ancient Days
Last Straw, Plus the Load, Snapped Camel's Back
Facts About “Ghost Fleet” Come from Headquarters
Ready to Build Set and Talk Around the World
Only Relativity Can Help Solve Piston Problem
Do You, Too, Want Articles on the Great Outdoors?
That's Some Job You're Trying to Hand Us
Here Are Two “Why's’” for You Tool Experts to Answer
IF POPULAR SCIENCE MONTHLY is not as hopelessly hog-tied with Professor Einstein’s theories as are several other magazines, its columns may be available for the publication of a three-dimensional interpretation of the “red shift” observed in the spectra of the more distant nebulae.
Prospectors Rush by Plane to Rich New Treasure Field
Is Belgium's Radium Trust Doomed?
A RICH man's rush! That is what this migration of mining engineers, geologists, and prospectors, sweeping by airplane into the Great Bear Lake region of Northwet Territories, Canada, is called. Not gold but radium is the prize; and radium is worth, ounce for ounce, a hundred thousand times as much as gold!
COMPLETED plans have just been announced for superliners that may bring back to America's merchant fleet the supremacy of the seas. Construction of the "blue ribbon" fleet for transatlantic service is propose by the United States Lines, subject to the enactment of favorable legislation by Congress.
Here Are Two More Heroes of Science Rules of This Contest—Read Carefully
FOR SOLVING NEW AND EASY PICTURE PUZZLES
HOW would you like to stay home tonight and, with a pair of scissors, earn $500? You have a chance to win that sum, and much more besides, by competing in our six-month Picture Puzzle Cut-Out Contest, which began last month and will continue until August.
TREASURE buried centuries ago, rivaling in riches the relics in the tomb of King Tut-ankhAmen in Egypt, was unearthed a few weeks ago by Alfonso X. Caso, Mexican government archeologist. Amid the ruins of Monte Alban, a mountain fortress in the highlands of southern Mexico, Caso discovered the secret burial vault of six ancient Indian war lords, their crumbling skeletons literally covered with a wealth of gold and jeweled ornaments.
POPULAR SCIENCE MONTHLY'S Committee Selects Distinguished Physicist as Recipient of Honor for His Outstanding Scientific Achievements
COMMITTEE OF AWARD
CONSPICUOUS in the long list of Dr. Langmuir s work stands the nitrogen-filled electric light bulb, which he invented, the atomic welding arc, and valuable contributions to radio
THE POPULAR SCIENCE MONTHLY Annual Award of $10,000 for notable scientific achievement has been conferred upon Di Irving Langmuir, research chemist and physicist and assistant director of the re search laboratories of the General Electric Company, at Schenectady, N. Y. Dr. Langmuir is the inventor of the nitrogen-filled incandescent electric light bulb and the atomic welding arc.
AN ARTICLE by One of the Best of All Aviators. He was Lindberghs Partner in Barnstorming and Is Famous as a Stunt Man, Air Mail Flyer, Teacher, Radio Operator, and Photographic Pilot
WE WERE waiting for the Winnie Mae, 2,000 feet above Jamaica, Long Island. All day, the telegraph at Roosevelt Field had been clicking out the progress of Post and Gatty as they raced down the home stretch in their eight-day circle of the globe.
ARMS TO FLAP BATLIKE WINGS OF MAN-POWERED AIRPLANE
THOUGH aviation’s annals hold no record that any man ever succeeded in making a sustained flight with a machine propelled by his own muscular exertion, a New London, Conn., inventor plans soon to make the try. He has constructed a pair of wings of twenty-two-foot spread, mounted in a framework so that they may be flapped by his arms.
FIREMEN on Brazilian railroads now hurl shovelfuls of coffee beans, instead of coal, into locomotive fire boxes. Because of an enormous surplus production, coffee has become so plentiful in this country that inferior grades are being used as fuel.
NINE-STORY apartment homes on stilts are proposed for New York City. Models of the dwellings were exhibited the other day by William Descaze and George Howe, the two architects who worked out the novel plan. The structures would have no first stories.
WATER power runs a labor-saving toothbrush recently exhibited in England. A miniature water wheel attached to the bathroom faucet spins the brush. A sw’itch on the handle controls the speed of the brush, which receives its rotary motion through a flexible cable.
No LONGER immune from execution are houseflies buzzing through the air, since the invention of a double-action fly-swatter with two surfaces that snap together. By nipping flies in flight, it avoids staining walls or furnishings.
A STRANGE “mechanical beetle” has just been completed at Maida Yale, England, for an attempt to break the world's thirty-six-hour nonstop speed record for automobiles. Efforts to reduce wind resistance are responsible for its unusual lines.
FIRST aid to chilly hands is a pocket-sized warmer, just placed on the market. Handy for those who work or play outdoors in cold weather, the device is about the size of a cigarette case. Cigarette lighter fuel or ordinary benzine furnishes the heat.
EARLY-morning risers may praise the inventor of a new razor that carries its own light for shaving. Since the tiny lamp’s beam is focused directly upon the path of the blade, no lurking stubble can escape the user’s eye. The hollow handle of the razor contains the battery that furnishes the current, while a switch is within convenient reach of the thumb.
A NEW motor car, streamlined and declared by its builder to be capable of 110mile-an-hour speed, recently had its tryout on New York streets. It is the third oddity in automobiles to come from the workshop of Capt. James V. Martin, airplane builder of Garden City, N. Y.
A VERITABLE “flying wing” is the United States Army Air Corps’ latest style of bombing plane. One of the fastest ever built, its clean streamlined form is emphasized by retractable wheels that fold up within the fuselage. Twin engines drive the low-wing monoplane.
WARM hands for Army flyers are assured by electrically heated flying gloves. Developed by United States Army Air Corps engineers, they consist of heaters, worn next to the hands, and glove-shaped covers that have heating elements extending from wrist to finger tips.
A NEW type of autogiro airplane, intended especially for Arctic exploration, is reported to have been invented in Russia, with the rotor or “windmill” mounted beneath the fuselage. Stubby wing surfaces, found in American models, have been entirely dispensed with, and the rotor alone sustains the machine in flight.
BRITISH military engineers have perfected an automobile truck that can dodge the bombs of enemy airplanes. When a bombardment from the air begins the trucks can leave the road and scatter in every direction. Their endless treads enable them to crawl over rocky country and through swamps.
WINGS on this privately constructed plane are replaced by spindles, whirled by two small motors. A third engine drives the propeller and furnishes traction. The machine, built behind locked doors in New York City, is the invention of John B. Guest, physicist and inventor of the Pacific coast, and was put together under the direction of I. C. Popper, construction and designing engineer of New York City.
New Method Stows Akron in Hangar in Spite of Twenty-Five-Mile Wind
IT TAKES only ninety men now to dock the biggest ship in the world &emdthe giant Navy dirigible Ai~'ronin her Lakehurst, N. J., hangar. An innovation in mooring methods practiced there, centering around a massive docking beam invented by Lieut. C. M. Bolster, U. S. N., has aroused the interest of airship experts the world over.
Another Chapter in the Story of LIFE, the World’s Greatest Mystery
Civilization Began a Million Years Ago
ANCIENT HOVEL TO MODERN SKYSCRAPER
HE WORKED FOR HIS FIRE
THE miraculous story of a speck of living jelly that became a man in a thousan million years was told in the early chapters of this series by Dr. William K. Gregory, of the American Museum of Natural History. The mechanism of heredity was explained by Dr. Herbert Ruckes, of the College of the City of New York.
Big Animals Shot for Movies in California "JUNGLE"
Trained Elephants and Hippos Stage Stampede and Attack Hit ;iters While Talkie Cameras Make Film "Thriller"
IN A small forest, an hour's drive north of Hollywood, Calif., twenty elephants and seven hippopotami recently were directed in thrilling jungle scenes for a talkie. Elephants dropped into deep pits and stampeded through the forest to destroy a pygmy village, following the commands of a director who guided them before a battery of talkie cameras which recorded their wild flight.
Fiction Lags Far Behind Thrilling Work of Modern Scientific Sleuth In Solving Mysterious Crimes
PRESSURE PHOTOGRAPH TRAPS BLACKMAILER
MAGNIFIED PHOTO SOLVES MYSTERY
MURDERER REVEALED BY PRINTING
HIS OWN PEN CONVICTED HIM
EDWIN W. TEALE
IMAGINE the cross on a "t," one five-hundredths of an inch thicker on one end than on the other, trapping a forger! Or the tail of a single comma exposing an elaborate fraud! Imagine a fake will plot nipped in the bud through the shape of a dot above an “i,” a cunning swindle stopped by the loop of an “e”! Such amazing feats are not taken from the pages of fiction.
SCIENCE at last is giving the baldheaded man a break. A brand-new theory says that, in many instances, baldness is caused by a deficiency in the secretions of the endocrine glands. Practical tests of the glandular treatment, at the University of Illinois College of Medicine, have led to remarkable success.
Many Unknown Spots in World Still Challenge Trained Adventurers
WHAT is said to be the world's only school for explorers has just been opened at Harvard University, Cambridge, Mass., under the name of the Institute of Geographical Research. Here young aspirants for adventure in strange lands will learn how to read a compass, set up radio communication with civilization’s outposts, make their own weather forecasts, and record valuable scientific data.
A STRANGE “sled” that gives cornfields a shave is the United States Department of Agriculture’s latest weapon in its fight against the European corn borer. This destructive insect hibernates during the winter in the stubble left standing above ground after the corn is cut.
LESS than eight inches long, a new heavy-duty tool can cut off bolts and rods with ease. It may be used in cramped quarters because of its compactness. This is made possible by the use of a powerful screw, instead of hand levers, to actuate the jaws.
WHEN painters were called in to work on the seventy-foot steel smokestack of a midwestern power plant, not long ago, they found no ladder had been installed to provide a means of reaching the top. An ordinary umbrella, hastily pressed into service, solved their problem.
To MAKE more vivid his instructions to novices, a German dancing master built an electrical robot that performs the proper steps in time to the music. At the same time, the animated figure points to a diagram illustrating how the feet should be placed at each stage in the dance.
IF FIRE should start unnoticed in home or factory, a new wall extinguisher not only fights the flames but also calls for help. The heat of a match is sufficient to melt a fusible link and release a powerful spring. Its blow smashes a glass container, releasing a stream of carbon tetrachloride liquid that turns to gas and smothers the flames.
WHAT is called the most luxurious car ever built to order for a boy has just been completed in England for the eleven-yearold son of an Indian prince, the Maharajah of Jodhpur. Beneath the hood is a four-cylinder motor that will drive the car seventy miles on a gallon of gasoline.
STAINED glass windows have hitherto been seen almost exclusively in churches, but a German craftsman has adapted them to other purposes as w'ell. His modernistic designs have brought the ancient art up to date for the decoration of public buildings.
UTILIZING a principle already applied in sound-absorbing materials for building walls, a new noiseproof pad for the typewriter provides a firm base but suppresses the clatter. The usual felt pad is covered with a durable and sanitary top of perforated metal, through which the noise passes and is absorbed below.
LIKE a miner’s headlamp is a new helmet for motorists, recently exhibited in London, England. An electric bulb aids night driving by directing a beam of light upon a road map, gasoline tank, or motor. The motorists’ hands are thus left free, and repairs or adjustments are easily made to the machine.
TRAP shooters may now correct their faults with the aid of a tracer shotgun shell, recently placed on the market. Like the tracer bullets in military use, it leaves a fiery trail plainly visible even in daylight. The light comes from a capsule of pyrotechnic material so placed that it travels almost exactly in the center of the shot pattern.
A HUGE electrified yacht just completed at Kiel, Germany, for an American runs either under the power of her 4,000 square yards of canvas or a Diesel-electric power plant. Four 800horsepower oil-burning motors drive the dynamos. The sails are handled by electricity, and when the skipper desires to run under sail alone, a “free-wheeling” clutch releases the propellers, allowing them to idle.
This fourteen-foot pump, with a capac ity of 60,000 cubic feet a minute, is one of sixteen that remove storm water from New Orleans THE LARGEST pumps in the world are now draining storm waters from the city of New Orleans, La. Twelve of these monsters, their size evident from comparison with the men and car in the photograph above, were in operation at this writing.
Concrete pillar for Hoover Dam ready to be tested Only this was left after testing machine finished with pillar WHAT kind of concrete will go into Hoover Dam, the mighty structure soon to block the Colorado River for water supply and electric power, is being decided in a Denver, Colo., research laboratory.
ILLUMINATED menus now come to the aid of restaurant diners wherever the lights are low. A bulb is fixed in the menu holder, shedding its beam upon the inserted card at the touch of a button. The battery is carried in a clip at the side, in a case resembling that of a flashlight.
SINCE alcohol lost from a car's radiator during the winter months means not only wasted money but danger of freezing, many inventions have been designed to recover it. Latest of these is an attachment for the radiator overflow pipe consisting of a pipe surrounded by cooling fins and a glass jar.
A BROWN mineral rich in the radioactive substance uranium, hitherto unknown to science, has just been discovered near Spruce Pine, N. C., and named “Clarkeite.” The find is important because so few ores of uranium are known.
BANK robbers well might quail before the latest mechanical contrivance devised for their downfall. This is a steel “bandit trap” of which its Oklahoma inventor recently exhibited a full-sized model. The device is a hollow cylinder of bullet-proof steel moving on casters, and just large enough for a man to stand inside.
A HANDY new device speeds the task of applying gummed rings around the holes of loose-leaf sheets. Resembling a rubber stamp, it holds 100 rings, one of which is deposited each time the end is moistened and pressed down upon a page. A central plunger, which disappears when pressure is applied, centers the reinforcing patch.
IF INTELLIGENT beings inhabit Mars, they may have received a radio broadcast from the earth the other day. That the ultra-short waves transmitted in a narrow beam from the roof of an East Pittsburgh, Pa., laboratory possibly reached our neighbor planet was announced by engineers of the Westinghouse Electric and Manufacturing Company, after testing a new outfit that broadcasts waves of hitherto unequaled power for a wave length as low as less than half a meter.
STRANGELY unlike their long-barreled forebears are latest styles in telescopes. A sawed-off instrument that is as portable as a camera and looks like an overgrown half of a pair of field glasses is shown in the upper photograph. Through the use of an ingenious combination of lenses and prisms, the short barrel gives the equivalent magnifying power of a much longer instrument.
RECENT experiments show that the cotton grower may soon be able to reap a greater profit by mowing the whole plant down—boll, leaves, and stalk—and selling it entire to be used in making artificial silk.
BEATING the other man to the draw meant life or death to the two-gun Westerner of an era not long past. With modern weapons and a new technique, the speed of the old-time “bad man” can be surpassed, as is demonstrated by J. H. Fitz Gerald, firearms expert and lecturer of Flartford, Conn.
SEWED with invisible stitches into the lining of a valuable coat or dress, a tiny padlock introduced by a German manufacturer protects the garment against theft. When the lock is snapped tight over a closet bar or coat hook, the coat cannot be removed without tearing it to pieces until the owner arrives with the key.
THE same tool that astronomers use to measure the size of stars now serves, in slightly modified form, to test the merits of dental fillings. A compact new “interferometer” for this purpose has been perfected and placed on the market by an Eastern firm.
YOUNG Frankie Mitchell, of Los Angeles, Calif., is the envy of his playmates, for his father owns the California concern that is said to turn out the majority of agate marbles used in the United States. Four-ton blocks of onyx furnish rav/ material from which the “aggies” are made. The blocks are neatly sliced into slabs seven eighths of an inch thick, and these in turn are cut into cubes. Then the cubes are carried, in trays of 200, to a rotary grinder where they become spheres.
AS A night watchman on a Long Island City pier, projecting into the East River at New York City, lifted his eves. a shaft of light from thc headlamps of an automobile pierced the darkness. The car was being driven down a “dead-end” street that ended at the river bank.
Air-Conditioning Plants, Developed for Factories, Will Soon Guard Homes from Dust and Bacteria
KENNETH M. SWEZEY
Many Industries, Unable to Meet Losses Caused by Sudden Changes in Condition of Air, A RcTIc cold, tropic heat, fresh May mildness in a sweltering July warm and moist indoor air when •the mercury outdoors has dropped below zero, are only a few of the conditions of climate now made to order by the new science of manufactured weather. Made-to-order weather is now an indispensable part of more than 200 different types of industries. It has made possible the modern broadcasting studio, as well as the sound-tight and air-tight “talkie” studio. Hospital rooms, supplied with controlled air, have saved premature infants; and, with oxygen added to the atmosphere, have helped the recovery of pneumonia patients. Air artificially cooled and dried in summer and heated and moistened in winter affords year-round comfort in theaters, offices, banks, restaurants, department stores, and public buildings. Trains with conditioned air have just been put into service on one great railroad. In the windowless Travel and Transport building of the 1933 World’s Fair at Chicago, in a large section of New York’s “Radio City,” and in the millionand-a-half-dollar windowless factory of the Simonds Saw and Steel Company, at Fitchburg, Mass., now nearing completion, air-conditioning machinery will provide the entirely inclosed interiors with comfortably tempered air, freer from dust and bacteria, and generally more healthful, than the purest “pure air” encountered anywhere outdoors in the modern city! Perhaps even more interesting to many readers than the knowledge that manufactured weather has been put to scores of extraordinary industrial uses is the news that small air-conditioning plants, capable of maintaining an ideal temperature and humidity relationship throughout all the weather vagaries of both summer and winter, may soon be made available for the average American home. A number of home plants for filtering, heating, moistening, and circulating the winter air are now in use. A few have been equipped with refrigeration for cooling, as well. When the engineers, still working on the problem, succeed in producing a safe, efficient, and entirely automatic refrigerating unit, at a price within the means of the average home-owner, summer cooling and dehumidifying may be universally accomplished at a cost probably no greater than winter heating. With complete air-conditioning apparatus in the home, broiling August sun will mean as little as piercing January cold; every day indoors will be a fine day! ' I 'HIS modern science, which has revo-*• lutionized many old industries and helped create new and which now promises to be one of the most important contributions to human health and comfort in the history of invention, is a technical triumph won almost entirely within the last thirty years, and particularly during the last ten. To be completely “conditioned,” air must be cleansed, controlled in temperature and humidity, and circulated uniformly. Willis H. Carrier, an engineer who has won international recognition for his contributions to the art of weather making, formulated this fundamental principle as early as 1901. By continuous control of all four factors, air-conditioning is differentiated from heating, ventilating, cooling, filtering, or humidifying. Operate Successfully When Machines Give Accurate Control of Temperature and Humidity Previous to the pioneering work of Carrier, air had been regarded chiefly as a heat-carrying medium, and attempts to regulate indoor climate in the face of an outdoor climate which changed constantly were centered almost entirely in altering the temperature. Carrier insisted that air must also be regarded in the light of its moisture content, since moisture is more important to comfort and to the special demands of industry than the degree of temperature. VX/’ITH precisely the same temperature * * (say seventy-five degrees Fahrenheit) we may have a “hot and depressing” summer day, the overheated, dried-out, midwinter atmosphere of an average office building, or the refreshing air of a spring day. The relative humidity, or the amount of moisture in the air compared with what it can hold, makes the difference. Not so obvious to the layman as the effect upon his personal comfort is the effect of indoor weather conditions upon industrial operations. Yet industry, and not human comfort, made the first demand upon scientific air-conditioning. Textile and paper mills, printing plants, candy factories, bakeries, powder mills, food preserving and storage plants, furniture factories, and scores of other industrial enterprises that worked with hygroscopic, or moisture-absorbing, materials bad long been victimized by the tantrums of unregulated weather. The first complete weather-making units were installed in the spinning and weaving rooms of textile mills. In the normally dry, dust-laden air, superheated by a maze of whirring machinery, the fibers of cotton or wool lost a valuable part of their natural moisture, becoming weaker, brittle, less pliable, and less satisfactory for further processing. Besides the interference with production caused by breaking of threads, shut-downs, and an inferior product, the material lost considerable weight during the manufacturing, with the result that when material was bought by weight and sold by weight, a considerable part of the profit evaporated in thin air. To keep down these losses, textile manufacturera resorted to the more or less haphazard methods of wetting the floors, distributing steam pots among the machines, and spraying water vapor directly into the air. Weather-making machinery, which filtered the air as it came from outdoors, sucked it through dense sprays of water to give it the required additional moisture, heated it when too cold, and by an elaborate duct system distributed it evenly throughout the mill, solved the problem with a satisfaction never before dreamed of by the mill operators. Printing (Continued on page 121) plants were next to recognize the boon of a climate that could be made to order. Fluctuations of indoor temperature and humidity had always been their worry. Changes in humidity produced every sort of deformity of paper—wavy edges, buckling, curling, creasing, stretching, and shrinking. It caused roller troubles and variations in ink. (Continued from page 55) Weather manufactured by the same type of equipment as was used in the textile mills, but adjusted for a lower and more humanly comfortable temperature and relative humidity, completely eliminated these printing troubles. Its value established, air-conditioning apparatus rapidly made its way into an everwidening circle of industries. Wood furniture and other wood products, sanitary ware, brick, tile, pottery, insulators, abrasives, confectionery, medical products such as coated pills, effervescent salts, capsules, and all kinds of standardized prescriptions ; still and motion picture film, lacquer and varnish, leather and leather goods, paper and paper products, artificial pearls, rubber, soap, food products, including bread—all these products, besides others which number in hundreds, are today made under conditions which make manufactured weather almost indispensable. A NUMBER of industries, including the rayon and machine-made cigar industries, owe their very existence to this weather. In the making of rayon, that silklike material conjured from spruce trees by chemists’ magic, temperature and humidity must be controlled precisely through every stage of the process. Into the three great plants of the Viscose Company, makers of seventy-five percent of all the rayon used in the United States, manufactured air is poured at the rate of 5,000,000 cubic feet a minute! The weather requirements imposed by industry run the whole range of weather variations met in experience, besides many that must be invented for the occasion. That every drop of moisture may be blotted from the paper insulation, telephone toll cables are made in a manufactured atmosphere maintained at temperatures above a hundred degrees Fahrenheit and extremely low relative humidity. Bread is raised in air that is warm and moist. The atmosphere required for many of the stages of candy making is cold and moderately dry. Medical capsule making demands an astonishing regulation of climate. Dust must of course be absent; temperature must be constant within a few degrees; greatest of all, however, the humidity must not vary more than one quarter of a grain (1/28,000 of a pound!) per cubic foot! A variation greater than this might change the viscosity of the gelatin sufficiently seriously to influence the production and quality. IN EGG storage houses, humidity is exceedingly important. If the relative humidity is too high molds and mildews develop, causing the eggs to become musty and have an unpleasant taste. If too low, moisture is robbed from the eggs, causing them to shrink and “rattle.” Conditions of climate other than timely or local have long been produced in greenhouses for raising crops out of season or nurturing plants foreign to the territory. Several colleges and scientific institutions, including the University of California, the University of Chicago, and the Boyce Thompson Institute for Plant Research, Yonkers, N. Y., have lately installed special compartments in which the temperature and humidity may be regulated to produce any combination of climatic conditions encountered from the equator to the poles ! (Continued on page 122) Tropical climate, faithfully reproduced by air-conditioning apparatus, enables “schedule ripening” of South and Central American fruits in northern storage houses. The fruits are picked when green, shipped north under cold storage, and ripened as needed by controlled weather. (Continued from page 121) In certain industrial operations the highest degree of comfort, as far as the weather is concerned, must be sacrificed to some special demand of the work. However, this is not always true, and some of the first uses of manufactured weather were for the health and comfort of workers. The first nonindustrial installation of importance was that of the New York Stock Exchange, engineered in 1902 by Werner Nygren. The new-fangled idea of humidifying as well as heating in winter, and cooling in summer, was sold with difficulty to a skeptical building committee. Early air-conditioning systems for summer use depended for cooling, in most instances, upon water sprays. The invention, about nine years ago, of a safe, efficient, compact, and automatic refrigerating unit revolutionized weather-making science. Cooling and dehumidifying systems were in a few years installed in the great movie theaters. Almost immediately the “summer slump” was turned into a bonanza. Auditoriums, department stores, restaurants, banks, followed suit. Not only did the new weather attract customers, but it increased the health and efficiency of workers. In offices, by requiring that all windows be kept shut, the use of conditioned air eliminated the distracting effect of noise. In 1928 and 1929 manufactured weather was introduced in the Senate Chamber and the Representatives’ Hall of the Capitol at Washington, D. C., to cool the nation’s representatives in summer and to keep them from drying up in winter. It may be interesting to note here that the dense water sprays which in an airconditioning system wash and humidify the air in winter also, with the aid of refrigeration, dehumidify the air in summer, thus adding a quality of comfort that mere cooling could never give. When moisture is to be taken from the air the water sprays are cooled below what is known as the “dew point.” At that point moisture is precipitated from the air like rain from a cloud that has been cooled. In the new Philadelphia Saving Fund Society’s building it is estimated that the air-conditioning apparatus, with a cooling capacity equivalent to nearly 1,000 tons of ice melting in twenty-four hours, may extract more than 8,000 gallons of water from the air distributed during a single humid twelvehour day! The broadcasting studio and the “talkie” studio had naturally to be equipped with a conditioned air supply. The latter, constructed often of concrete and gypsum blocks, lined with some sound-deadening substance and entered by means of an outer and inner door, is often as well insulated and as airtight as an ordinary refrigerator. All the air that the occupants breathe must be forced in and out at a rate sufficient for health, yet noiselessly and without any abnormal draft. In the Harlem Hospital and the Rockefeller Institute, New York City, and the University of Maryland Hospital, to mention a few of the pioneers, oxygen chambers, which allow independent control over temperature, humidity, and carbon dioxide content of the air circulated—besides the possibility of supplying additional oxygen—have been successfully used in the treatment of pneumonia cases. A number of air-conditioned rooms are also in use for the nurture of premature babies. The new home office of the Metropolitan Life Insurance Company, rising now in New York City, will be the largest office building in the world to be completely supplied with manufactured weather. Tested thoroughly in industry and in public buildings, plants for weather-making are now available for the home. The cost of the necessary equipment is from a third to a half more than the cost of a good two-pipe steam heating plant. Although perhaps less spectacular, the maintenance of a scientifically correct relative humidity in winter is at least as important as summer cooling. The latter, plus dehumidification, is a problem that may soon be solved. Compared to the average food refrigerator, the amount of refrigeration required to cool an ordinary eight-room house is amazing. The food refrigerator produces a cooling effect equal to that produced by the melting of one-tenth of a ton of ice a day. Refrigeration equaling the effect of six to ten tons—or from sixty to one hundred times as much—would be necessary to cool the house! However, the cost of operation of the larger plant would be proportionately less. It has been estimated that the young science of manufacturing weather is already saving industry about $15,000,000 in cold cash every year. Who dares to predict what it will contribute in the next few years—when it finds extensive use in offices and homes—to the intangible values of comfort and health !
Marvels of the Deep shown in Amazing Museum Exhibit
4 ERELY by walking down a flight of stairs. a visitor to the American Museum of Natural History, New York, may soon experience the sensation of donning a diver's helmet and exploring the wonders of the sea bottom. Paintings on the upper floor of the Museum's two-story Hall of Ocean Life, nearing completion after ten years of labor and the expenditure of $100,000, have been executed to give a realistic imitation of sea scenes.
Talking Tape Ousts Court Stenographer in British Test
THE fallibility of human stenographers may trouble British law courts no longer, since a recent test of a sound recording device known as a “talking tape” to receive the evidence developed during a hearing at Manchester. When the proceeding was over, the metal tape bearing the sound record was played back to the judges.
BECAUSE it stood squarely in the path of a projected road through a Washington, D. C., park, a big full grown magnolia tree recently took an unusual journey. Rather than cut it down, Government officials set a hundred men at the task of moving it.
MANY a strange craft has passed beneath the Fremont drawbridge, near Seattle, Wash., but the towerman must have rubbed his eyes the other day when he saw a house approaching on a scow. Nevertheless he swung the draw open for the unusual cargo, and for another just like it that soon followed. The two dwellings had been purchased by C. C. Casad, a city engineer, in Seattle.
A CHILD can lift a piano with the aid of a new jack invented for the purpose and recently patented by an Abilene, Kans., piano tuner. It lifts the heavy instrument so the floor underneath may be cleaned. Housewives might also find the invention useful for raising beds and other weighty pieces of furniture.
EASY to read at a glance is a new dial tape measure. When it is unrolled to the length of the object measured, the dimensions are instantly shown on the indicating face. The small hand registers feet and the large one inches. Three sizes from twelve to a hundred feet are made.
RECENTLY in Texas a machine was demonstrated that cuts steps in hillsides. Where hillsides are not terraced in some such manner, swiftly flowing water carries away much fertile soil. The new terracing machine, in appearance and operation, is similar to a road scraper.
WHEN world diving stars vie for honors at the coming Olympic Games in California, none will be able to say that the springboard is too limber or too stiff. An adjustable board, the invention of a San Francisco amateur swimmer, will be used. The point of support, or fulcrum, may be moved by hand or by electric motors to a place that suits the individual’s weight.
A REMARKABLE new type of refrigerated truck for delivering perishable products, such as meats and butter, makes the refrigerant do double duty. After it cools the body of the truck, it runs the engine, taking the place of gasoline. The refrigerant, a new fuel gas perfected by a large oil company, is compressed to liquid form and carried aboard the truck in tanks no larger than standard gasoline tanks.
WHEN foxes made repeated inroads upon his livestock, an English farmer devised an innovation in “scarecrows.” He placed a dummy fox-hunter, properly outfitted in riding costume, atop a small tree where it is plainly visible in all directions.
COOKING gas for the household range is manufactured economically from gasoline by an ingenious electric device invented in Germany. Fuel is poured into a cylindrical tank through a filler tube, and an electric cord is plugged into the nearest socket.
Strange Instrument Built to Solve Mystery of Cosmic Rays
R emarkaiVe Radiations from Remote Source Lead to World-Wide Investigation
RAYS FROM OUTER SPACE HIT EARTH
THE world's first "cosmic ray telescope" shortly will scan the heavens from the roof of a Swarthmore. Pa., laboratory. Its users seek the source of the mysterious rays from outer space which bombard the earth with such force that only a fifty-foot wall of lead will stop them.
HERE is an incomplete water faucet. How would you complete its mechanism so that no spring will be required to close it or keep it closed? You are free to modify the part A in any way you choose, and you also may add a single additional part. The six diagrams below give the solution of the cam-movement problem of last month in which a valve was to be closed and opened.
Above, forty-pound boat ready for use and at the right, same boat folded compactly for carrying ESPECIALLY designed for campers is a folding sailboat recently placed on the market. Stored for carrying, it makes a compact bundle weighing only forty pounds, easy to transport by train, on an automobile luggage rack, or carried on the back.
WITH a new “parking mirror” installed on his right fender, a motorist can see just how near the curb his front wheels are. In a tight place, he can also avoid grazing the car in front in getting in or out of a small parking space.
BUILDINGS a mile high are made pos sible, engineers say, by the invention of a brick so light that it will float in water. It is the latest accomplishment of Dr. Charles F. Burgess, one of the nation’s most distinguished chemists, who recently received the coveted Terkin medal for achievement in that field.
WHEN depression struck the Far East, two British planters started overland for London on a pair of motorcycles. As far as the Siamese frontier, they experienced no difficulty. In Siam, the muddy roads were impassable and the cyclists were stopped until a machinist at a local tin mine came to their rescue.
To ELIMINATE dangerous curves in a New Jersey state highway at a point where it crosses a canal, engineers have built what is called the craziest bridge in the world. Its unusual diamond-shaped construction is made necessary by the fact that the new road crosses the canal at an extreme slant.
WILL automobiles of the future carry their motors in their wheels? Inventors say such a scheme of “unit power” would lead to marked advantages in traction, efficiency, and ease of control. One proposes steam-driven wheels for motor cars.
Gunpowder Now Used to Drive Rivets and Splice Cables
APPLICATION of gunpowder to such varied tasks as driving rivets, splicing electrical cables, and drilling holes in ships’ hulls was demonstrated recently in New York City with the aid of devices perfected by Robert Temple, noted wartime inventor.
A DUMMY with a wooden head and painted features gives students in a German school an opportunity to practice the technique of rescues from poison gas. For some time Germany has been educating its citizens in defense against an enemy gas attack from the air.
No LONGER is it difficult to call a taxicab on a rainy night. A new umbrella with a signal lamp at the tip solves the problem. The bulb is lighted by a switch in the handle, which also holds the battery that supplies the current.
LAST STAGECOACH OF OLD WEST STILL MAKES REGULAR TRIPS
LIKE a ghost from the days of the forty-niners, a stagecoach drawn by six fleet horses dashes, several times a week, along an unfrequented California highway. On the driver’s box of the swaying vehicle sits Capt. William Banning of Los Angeles, veteran driver of pioneer times and a son of the man who founded the first stage lines in southern California.
CHILDREN learn to play the violin and ’cello quickly with a radical method of teaching recently introduced in New York State schools. Music for them to play is written in giant notes, each of a certain color corresponding to its pitch. The fingerboard of each instrument is similarly marked with colors, giving the corresponding finger position for each note.
FLOATING balls of cellulose composition, with centers of cobalt steel, have recently been used to demonstrate the symmetry of magnetic forces. The steel alloy used is one of the most highly magnetizable substances known. When four of the magnetized balls are dropped into a vessel of water, they immediately group themselves in a figure like a three-pointed star, with the outer trio evenly spaced about the center one, as seen in picture at the right.
A NEW aid to carpenters is a portable band saw that weighs but twelve pounds. It is easily carried to the place of work, and is said to cut a piece six times as quickly as it can be done by hand. An electric motor drives the labor-saving tool. For a semipermanent installation, it is attached to a convenient bench by a few screws.
So SENSITIVE that it can tell your weight to within one gram, or about one twentyeighth of an ounce, is a new balance recently exhibited before members of the American Society of Heating and Ventilating Engineers at Cleveland, Ohio. It is being used in a study of the changes by which the human body gains or loses weight, because of minute variations of temperature and humidity.
ENTER “carbogen” to save the lives of pneumonia victims. Inhaling this new gas, a mixture of oxygen and carbon dioxide, is reported to have proved effective incases usually considered hopeless. The photograph above shows the strange apparatus developed by two Yale University medical experts to administer the treatment.
AN AUTOMOBILE raises itself to permit changing a tire, with the aid of a jack devised by a Louisiana inventor. Folded, it occupies small space in the tool kit. Should a puncture occur, the motorist unfolds the jack and places it just in front of the wheel. Under the engine's power, the wheel climbs an inclined platform until the brake drum drops into a notched support, with the tire clear of the ground.
A LARGE milk concern serving New York City has opened its own noise abatement campaign. By equipping its horses with rubber cushions for their shoes, and providing its drivers’ milk-bottle baskets with rubber shock-absorbers, it plans to lessen the racket of early morning milk deliveries.
A CHICAGO dentist develops X-rays of his patients’ teeth quickly and in full daylight. During exposure and development the sensitive film is inclosed in a lightproof but moisture-permeable envelope he has invented, shown above.
YOUR home chemistry laboratory usually contains all that you need to perform several amusing tricks or stunts. Among the simplest are the color-changing of liquids, or wine-waterink-milk tricks. Perhaps the most popular of these is the pouring of a dilute sodium hydroxide or sodium carbonate solution (a pea size lump of sodium carbonate dissolved in a tumbler of water) into an apparently empty glass, which in reality contains two or three drops of phenolphthalein solution.
WHEN Dr. Willis R. Whitney, director of the research laboratory at the Schenectady plan of the General Electric Company, hired the brilliant young physicist, Irving Langmuir, some years ago, he escorted him down a hail and threw open a door.
LIKE a lot of other tricks, reading a radio blueprint is astonishingly easy once you catch on to it. Yet radio blueprints, or, in fact, blueprints of any kind, always will remain just so much Greek to thousands of radio fans. Show a five-year-old child a picture of a house or a cat or a dog and the youngster doesn’t have to be told what it is, yet the child is performing with ease precisely the same stunt a man balks at when he throws up his hands in despair at sight of a radio diagram.
Details of Simple Receiver Batteries or Hooked Up to
That Can Be Operated with
the Electric Light Current
ALTHOUGH the gateway to amateur radio two-way communication is a Government examination for a radio operator s license, as was explained last month, you can get into the receiving end of the game as soon as you wish—the sooner the better. In fact, your study of the code will be greatly helped by hours of listening on the amateur waves.
BEWARE of Polish That Eats Away Car's Lacquer, Gus Warns as He Tells How to Keep Auto Like New
WHERE'D you et this stuff?" Gus Wilson asked as he picked up a gaudily decorated can that was resting on the edge of his partner’s desk in the office of the Model Garage. “That’s a marvelous new auto polish, Gus,” Joe Clark replied as he pushed aside the pile of bills in front of him.
Capt. E. ARMITAGE McCANN'S latest and best model...
Hull Details of Whale Ship Wanderer
WHAT MATERIALS YOU WILL NEED
IN THE old days, whaling was desperate business—and big business, too. Many an American fortune was founded by the efforts of the grim and incredibly courageous crews of whaling ships. Their hardihood and seamanship were the pride and boast of every New England port.
A “JOLLY ROCKER” built like the one illustrated will give children many happy hours. It is perfectly safe because even the most violent rocking will not cause it to tip over, and it is strong enough to defy the destructive efforts of a whole gang of youngsters.
IF ONE has access to an air blast, it is not difficult to free small dies and other tools from fine chips and cuttings. At the home workbench, an equally effective method of cleaning small tools may be used simply by obtaining a hand bulb and tip for a hydrometer at a ten-cent store.
To REPLACE a small shaft in a flashing device, I needed a piece of wire .096 in. in diameter. I had a coil of music wire of this diameter, so I cut off a piece about 2 ft. long, suspended a 5-lb. weight from one end, and ran a torch up and down the wire.
FOR draining aquariums or other liquid containers, you will find a self-starting siphon useful. To make one, obtain a small glass bottle or vial, a rubber cork to fit, two pieces of glass or metal tubing about 2 in. long, and some rubber tubing that will fit snugly over these pieces.
. . . The softest and most comfortable of all footwear
LEONARD F. MERRILL
MOCCASINS! Footwear of the American Indian, they have been worn by nearly all the great hunters, woodsmen, and scouts of American history or fiction. That is because they are the softest, easiest foot covering ever designed. To make a comfortable and serviceable pair of moccasins for your coming vacation requires no special tools or skill, and the materials are not expensive.
Made from Solid Mahogany and Complete Even to the Finishes
FOR its April project, the Popular Science Homecraft Guild is offering a construction kit with which to assemble a genuine mahogany book trough of exceptional grace and delicacy—the equal of the finest custom-built furniture in design and quality.
THOSE who are building the new POPULAR SCIENCE MONTHLY three-in-one boat Vagabond and have faired the framework as described at the end of last month's article (P.S.M., Mar. '32, p. 75) are ready to begin planking the hull. If you missed that article and wish to construct one of these inexpensive but fast and seaworthy little boats, you can obtain a blueprint with complete working draw ings for 25 cents (see page 110).
DUG out with everything from a penknife to grandfather’s old saber, dandelions continue to grow and thrive. A better tool with which to combat them is illustrated. It is a sort of easily handled harpoon—an old mower sickle section firmly bolted into a slot cut in the end of an old rake or hoe handle.
WHEN the small slotted-wire “keys” that come with some kinds of canned food tear the tin off at an angle, leaving the can only partly open, a pair of round-nosed pliers may be used to finish the job quickly and effectively. Grasp the edge of the torn tin with the pliers, twist them to the right, and the remainder of the can top will roll off the way it is meant to do.
IN THIS blindfold cigarette trick, the spectators place one each of several different brands of cigarettes on the table. The performer snips strips from a. sheet of black paper and gives one strip and one cigarette to each spectator to be “blindfolded” by covering up the brand mark.
THIS combination rabbit hutch and wire run can be wheeled around as a unit, with the advantage that the rabbits may be moved when necessary to fresh grass and also kept in the shade. The run or cage is covered with 1-in. mesh wire netting and has no bottom, but a bottom of 2-in.
IT IS a simple matter to convert unsized paper into synthetic parchment for making greeting cards and underlays for mounted photographs, as well as other purposes for which genuine parchment would be appropriate. Prepare a strong solution of sulphuric acid by gradually and cautiously adding concentrated acid to half its volume of water.
Fig. 3. At left: Diagram of layout, where D is diameter of circle through the center of the-extreme lens. Below: How the lenses fit in the countersunk holes
GEORGE H. WALTZ
DON MARSHALL, my neighbor, who is a television experimenter and a radio expert, led me down the stairs to his well-equipped basement workshop. “Have you ever tried to cement glass to metal?” he asked as he snapped on the light. “It’s some job—unless you know just how to do it.
MANY house models of extraordinarily fine design and craftsmanship were entered in our "Build Your Home in Miniature” Contest (P. S. M., Nov. ’31, p. 82). The first prize of $50 was awarded to H. E. Chesebro, of Schenectady, N. Y., for the model shown in Figs. 1 and 2. The sides are of ½ in.
Each month we award $10 for the best idea sent in for motorists. This month’s prize goes to Wesley Kuhlmann, Woodcliff, N. J. (Fig. 3.) Contributions are requested from auto mechanics, both amateur and professional, and if published will be paid for.
L'OR week-end picnics, camping trips, ^ and long tours through arid regions, a convenient water supply can be arranged by fitting a special tank to the running board. Procure a suitably shaped gasoline tank from an auto junk yard. Clean thoroughly with washing soda.
r I 'HE simplest way to test a tube for leaks is to place it under water and watch for bubbles. However, the usual round tin tub or wooden wash tub takes up a lot of room. An excellent water container for this purpose is a section of a large truck tire attached to hood at once whenever there is any repair work to be done.
WHAT I want to know is, what is color value in a photographic film and how does it affect the pictures I take? How can a film that takes pictures in black and white have any color value if it doesn't register colors at all? This talk about ‘panchromatic,’ ‘orthochromatic,’ and all the other fancy names has me in a fog.
ONE problem every arc welding operator has to meet is keeping his cable easily accessible and in good order. In two of the accompanying illustrations is shown a convenient spool that will hold 250 ft. or more of double cable and can be wound or unwound as required.
A SIMPLE and safe hook for handling heavy metal sheets, with no sharp corners to tear the hands or damage metal surfaces, may be made as shown from three 6 by 8 in. oval sections of ¿4-in. steel plate. The lower halves of two of the oval sections are bolted on each side of a filler of 34-m. plate.
EVERY machinist knows how difficult it is to keep the lathe center constantly against the tap when tapping by hand in the lathe. The accompanying drawing shows a substitute center A pressed into the end of a piece of tubing or pipe B, which is bored to a slide fit on the tailstock quill D. The spring C is the active member.
ANY small celluloid drafting triangle is easier to use for fine cross-section work or intricate mechanical drawings if a handle is fitted to it as illustrated in the photograph at the right. This finger grip is nothing more than a common soft rubber suction sink stopper, trimmed down until it does not extend beyond the edges of the triangle.
CUT from old belting, the holdback shown below is better for work being turned in the steady rest than the belt lace ordinarily used. To apply it, run the drive plate forward, place the holdback on the work, insert the pins, and run the plate back, which will tighten the strap and hold the WORK.-ALLAN B. SHAW.
R EAMERS, plug gages, or similar tools that must be finished under 3/16 in. in diameter always should be made with male centers. When making an angular cutter, mark it with the angle it will cut, never with that of its own form. If a light bulb burns out, a good man will never replace it with one taken from a vacant machine.
SCREWS, bolts, and other small parts often have to be soaked or washed in kerosene or gasoline to remove grease and dirt. This can be done more easily if they are placed in an inexpensive water soaping device such as may be bought in most stores which sell house furnishings and kitchen supplies.
GARDENERS, florists, and flower lovers use paper band “pots” by the thousands for sprouting seeds and for conveniently transferring plants from cold frames to the field. The bands no: only make the small plants easy to handle, but protect young cabbages, beans, and other tender plants from the ravages of rabbits and cutworms.
IN MAKING coaster wagons, boys are confronted with the problem of fastening the steel axles to the wood securely enough to withstand rough usage. The usual method is to drive in spikes and bend them over the steel axle, but in a collision these either loosen or split the wood. A better method is to cut the heads off 14-in. carriage bolts, bend the ends to a Ü, and set the bolts in holes bored in a “two-by-four.
COING out to the mail box every few minutes to see if a belated letter carrier has arrived is never neces sary with a mail box like that illustrated It announces the postman's arrival by ringing a buzzer inside the house. mcidentally, it is a receptacle large enough to hold papers and magazines.
ABOUT 3,000 holes 54 in. in diameter and 2 in. deep had to be drilled in an especially hard concrete floor of a school auditorium for fastening the seats. I tried various kinds of twist drills in an electric drill, but they failed to do the work.
RUSTIC settees of a type that will enhance any garden may be made at a cost of about 50 cents each by anyone who is willing to cut his own wood. I use willow, hickory, or sassafras found along streams, old fence rows, or in cut-over land. The hickory should be cut in the late fall or winter, otherwise it is likely to become wormy; but the other two can be cut at any time, and either worked up at once or allowed to dry.
HOW TO SET UP A SMALL GRINDER for Truing Lathe Centers
NO MATTER how carefully and expertly a machinist operates a lathe, he finds it necessary occasionally to repair the damage caused to the centers by wear and accident. The amateur mechanic finds it equally essential to have a ready means of reforming the 60-deg. points, which must be perfectly true if accurate turning operations are to be attempted.
IT IS no secret that ordinary cylinder locks, night latches, and electric door openers can be forced when installed on a door which has the common type of socalled “loose” stops and not a solid, rabbeted jamb. Any thin instrument—a longbladed knife or the like—may be slipped between the stop and the jamb and used to press against the beveled or rounded surface of the lock bolt, causing it to slide back and unlock the door; or, if
FOOT-HIGH rabbits, jauntily sitting on their haunches, form the ends of this unique rack for holding brightly colored Easter eggs. Although the rack illustrated was designed to hold fifteen eggs, the number can be altered to suit by changing the dimensions of the two rack pieces.
A COMBINATION flower box and trellis like that illustrated allows vines to be grown indoors or in special locations outdoors such as on a flagstone terrace, a porch, or the roof of an apartment house. An old packing box about 10 by 13 by 28 in.
TROWEL stock in diameters of Y in. and less, such as is often needed for model work, can be prepared by the following method: In a piece of steel 1/16 in. or more thick, drill several holes, one the same diameter as the dowels are to be and the other progressively larger by slight degrees.
1V/Î OST home workshops do not have -i-’-*facilities for grinding small jointer knives accurately, but the knives can be kept in good condition by honing them occasionally on an oilstone. As they are awkward things to handle, I made a clamp of hardwood, as shown, to hold them.
"AT PRESENT I have two locomotives, some passenger and freight cars, a couple of switches, and enough track to make quite a large oval shape. What I want to know is, what is the next step in this model railway game? What shall I do now?” That question, with minor variations, occurs far more frequently than any other in letters from model railway enthusiasts.
A SMALL leak in a lead water pipe often can be permanently repaired by the method illustrated. First turn off the water. Then, if the pipe has become somewhat flattened at the point where it is leaking, endeavor to squeeze it back to its original shape by using a pair of large gas pliers.
REALISTIC looking cowling for any airplane model of the in-line engine type can be made easily from thin aluminum. In a flying model the slight additional weight at the nose allows the wing to be moved farther forward, and the speed will be greater than if the front of the ship were left open.
INTRICATE fretwork for ship model5 can be cut from wood without splitting if an ordinary nonwaterproof three-ply panel is used. Draw the design, score around it with a sharp knife, and remove the waste wood down to the second ply or core stock, leaving the ornamentation in relief.
TF YOU are planning to build our new whaling ship model described on pages 75 to 78 of this issue, you can save yourself much time and effort by buying a complete set of the necessary materials from the Popular Science Homecraft Guild. By extending its activities to the field of model making, the Guild has solved what has always been one of the most troublesome problems encountered by those who wish to take up the hobby of building ship models—that is, the difficulty and expense of having to shop around for so many miscellaneous small parts of unusual sizes and kinds.
$10 for the best Photograph Showing COLOR CONTRAST
For the most photographically perfect picture showing color contrast submitted on or before May 2, 1932, POPULAR SCIENCE MONTHLY will pay $10. The only condition is that it must be taken during the months of March and April, 1932, by an amateur.
EVERY normal human body is full of ice, according to Dr. N. Marinesco, French biochemist. But it is in no danger of freezing, since the “ice” is of a different variety from that found in the household refrigerator. Water forms at least six different kinds of ice, science has discovered, and variety number six is a “warm ice” capable of existing at temperatures between forty and 176 degrees F. It can be formed in the laboratory only under the enormous pressures of more than 100,000 pounds to the square inch, but the forces acting within the microscopic layers of living tissue are believed to be sufficient for its formation.
THE last two chemical elements to be discovered, numbers eighty-seven and eightyfive, have had their formal christening. “Virginium” and “Alabamine” are the names chosen for them by Prof. Fred Allison, Alabama Polytechnic Institute physicist under whose direction they were found.
THE earth’s life-sustaining blanket of oxygen gas is a comparatively new acquisition, as geologists measure time. So declares Prof. Alfred C. Lane, of Tufts College, who holds that carbon dioxide, familiar as the “fizz” in soda water once constituted a large part of our atmosphere.
How to turn nature’s honey into a nonsticky form that can be cut like hard butter and that keeps indefinitely in cans or glass jars is the discovery of a young Cornell University student of agriculture. Of its own accord, honey after months or years will become a mass of grav-white crystals.