MARTHA!” called out Waldo Sims, as he burst in the front door of their bungalow one evening. “How soon can you jump into your best bib and tucker? We’ve got some important celebrating to do. I’ve reserved a table at the Monte Cristo Club right on the ring-side just for you and me.
Some Surprising Facts about Ref rigerator Care Are Brought Out by Laboratory Tests
Prof. R. D. Morrill
"HURRY up and close the icebox door!” is an instruction that echoes through many an American home, and we sometimes wonder if this business of getting the refrigerator door closed quickly is worth all the commotion it causes. Just what happens, when this injunction is not carried out as promptly as it ought to be, now has been definitely determined.
THE article on 'Are Women as Smart as Men?’ was exceedingly interesting. I am not a psychologist, nor could I be scientific if I had to; but I am a woman, therefore I enjoy talking back. “As Mr. Lecky says, women are ‘newly freed in body, newly independent in action and expression.’
U. S. Medical Authority Explains the New Scientific Yardsticks of Your Capacity to Pilot a Plane Safely
L. H. BAUER
IN THE wake of the epochal flights of the last eighteen months a great wave of enthusiasm for aviation has swept the country. Every boy sees himself a potential Lindbergh. Thousands of Americanshave made airplane flights as passengers; hundreds of young men—and men not so young—have enrolled in training schools for pilots.
PEERING into the future is, for most of us,mighty chancy business. For Nikola Tesla, world-famous electrical wizard and inventor extraordinary, it is second nature. He is an enigma, this man Tesla. His astonishing discoveries and his prophetic visions have established him in the popular mind as a genius and a fantastic dreamer.
DIRT? The inside of a smokestack is a white porcelain tub compared to the cinder-tunnel that crawls beneath the soaking-pits of Midwest Steel. Heat? The breath from a stack's mouth is a cooling zephyr beside the blast that radiates from those incandescent rooms of hell.
New Tests Show How to Have Your Picture Taken—Kinks for Camouflaging Big Feet or Shortening a Long Nose
HE WON’T get my vote; I don’t like his looks.” How many times, in the last few months, have you heard that said of one or the other of the candidates for the Presidency of the United States? These are days, thanks to the motion picture, radio, and the news photographer, when we don’t have to go to see or hear Presidential candidates.
New Lamps That Flash Warnings in Daytime as Well as at Night Replacing Semaphores
A FAIRYLAND of blinking color flashes—that is the fifty-mile stretch of track between Attica Junction and Deshler, Ohio, where the Baltimore and Ohio Railroad has just installed the latest in railway signal systems. Vertical bands of green light speed fast expresses on their way.
A House with Food Walls; Mountains of "Smokes,” and a City Lot of Gum, Go on South Pole Voyage
EDWIN W. TEALE
WHEN Commander Byrd’s flagship, the bark City of New York, with its gleaming white hull and orange masts slid out of New York harbor recently for a two-year visit to the Antarctic, it carried the first consignment of the most expensive and complete equipment ever provided for a voyage of exploration.
BILLIONS of dollars” is the value placed upon the recent discovery, at the University of Illinois, of a method of coating metals with aluminum by electroplating. As announced by Prof. D.B. Keyes, of the university faculty, it solves a problem which has baffled experimenters for years—ever since the electrochemical process of extracting aluminum was discovered, back in 1885.
DUST of the air—even coal smoke—eventually may come into wide practical use in scientific rain making. Such was the recent assertion of Prof. C. F. Knipp, a chemist of the University of Illinois, who demonstrated how, with the aid of dust, experimenters now can make rain fall in the laboratory.
WHICH wear more sensible clothes, men or women? An answer to the old disputed question at last has been supplied by scientific laboratory experiment. And it is all in favor of the women. The scientist who tackled this ticklish test is the noted German hygienist, Dr. Ernst Friedberger.
FOR more than two years, 8,000 men, women, and children of Hagerstown, Md., have been the subjects of the first study of its kind in the world, an investigation by the U. S. Public Health Service to learn new facts about the relation of age to physical fitness.
FILMS of metal so thin that they are utterly invisible to the human eye have not only been produced, but also measured, in the Bell Telephone Laboratories at New York City. In recent experiments under the direction of H. E. Ives, to improve the design of photoelectric cells for television, layers of a light-sensitive metal known as rubidium, of various thinness, were deposited inside of glass tubes. When best results were obtained with one particular film, the task remained to measure it.
THE earth is cooling off, according to the theory recently advanced by Dr. William Bowie, Chief of the Division of Geodesy, U. S. Coast and Geodetic Survey. Millions of years from now, he believes, our world will be a lifeless frozen ball. A billion and a half years ago, he says, the earth’s temperature was just below the boiling point of water, 212 degrees F.
MILK bottles soon may disappear, along with bottling machines and the daily rounds of milk wagons. According to Prof. Victor E. LaMer, of Columbia University, chemists are at work to produce milk in powdered form to simplify the problem and save costs of distribution. And Dr. H. E. Barnard, consulting chemist of Indianapolis, Ind., states that powdered milk already is being marketed in limited quantities.
Miners Buried Alive Deep in Poisonous Tomb Saved by Uncle Sam’s Trained Rescue Crews—How New Inventions Help to Safeguard Lives of a Million Workers
AMERICAN breakfast tables were saddened one morning recently by news of four mine disasters. A total of 223 lives had "been snuffed out in four days as an incident of the extraction of fuel and metal vital to the operation of our complex system of civilization.
THE attractive dwellings pictured on this page are typical representatives of the latest advances in design and construction. Chosen from among hundreds of houses displayed in a recent nation-wide “Better Homes in America” competition, they offer convincing proof of the fact that attractive homes, embodying every modern comfort and convenience, can be brought within reach of families of modest means.
Homes Already Reared in a Few Hours Point the Way to Wholesale Building by Assembly of Standard Parts— Mass Production Will Reduce Labor Costs
ARTHUR A. STUART
IN DETROIT, where automobiles are made and assembled with the speed and economy of a magic that is purely American, a steel house took shape recently with similar speed. One hundred minutes after a small crew of erectors appeared on that Detroit site the steel frame of the house was boltedinto shape, its permanent stairways were in place, and all was in readiness for the next stage of construction—the placing of the floors and roof.
You Can Have It Always on Tap with Improved Automatic Heating Units That Save Countless Worries in the Home
JOHN E. LODGE
MARY! Why in blazes isn’t there any hot water this morning? You might at least wait till I get through shaving before you draw it all off!” “It’s your own fault, John. You forgot to light the heater when you got up. Now you’ll just have to wait.” Conversations like this, with variations, are common in thousands of homes.
How Modern Science Tames Smoke and Flames Is Revealed in the Amazing Experiences of New York City’s Fearless Chief
HENRY MORTON ROBINSON
MAROONED! First Officer John Kenlon clung to a barren ledge of Hog Island, 1,800 miles west of the coast of Australia, and watched the last splintered planks of his vessel sink beneath the waves. Thirty-six hours ago he had been treading the bridge of a crack clipper ship bound from Liverpool to Melbourne.
How Two Young Brothers Invented a Marvelous Machine Which Fixes the “Runs” in Women's Silk Hose
TWO young jobbers of hosiery have just become potential millionaires. Within the last few weeks, they have seen their invention of an amazing stocking repair machine valued at $20,000,000. Perhaps, by the time you read this, thanks to their device, a disconsolate maiden with seemingly ruined stockings may walk to the nearest store and for a quarter or more, depending on the damage, have the pair returned to her as good as new.
New Tests Reveal Astonishing Facts about Secrets of Human Life and Problems of Environment and Heredity
E. E. FREE
WHEN Nature sets out. to produce a pair of twins one of her methods is the exact reverse of the marriage service. Instead of joining two to make one, Nature divides one to make two. The chief reason why many pairs of twins are so astonishingly alike that even their own mothers sometimes get them mixed is that they are not really two individuals at all, but are two halves of one individual, split apart early in the formation of their bodies.
New Safeguards for Electric Sets—Testing Loudspeaker Quality— Uses for Old Parts —Hints for Drilling Panels
SEVERAL devices have appeared on the market that will prove useful if your electric receiver is located where the voltage of the light current is too high. One of them is shown in the illustration on this page. It is plugged into the electric light socket, and the plug from the electric set is screwed into the socket provided.
HUMAN ears are such tricky pieces of mechanism that they can fool you into believing something that actually is not so. That is why it is so hard to judge loudspeakers. After hearing a loudspeaker in a friend’s home, you may decide that it is not as good as yours when you turn on your own radio receiver a half hour later.
THERE are two ways to ruin a radio panel during the drilling operations. One is to let the drill slip and scratch an ugly gash across the panel that will prove an eyesore all the time the set is in use, and the other is to drill the holes in the wrong places.
THE fact that radio parts ordinarily do not wear out brings up the problem of what to do with old-style variable condensers, sockets, audio transformers, tuning coils, cumbersome old dials, and so on. If you have been a radio experimenter for some time your workbench undoubtedly is cluttered with parts that are just as good as they ever were.
RADIO receivers do not become less efficient as they grow old unless soldering paste has been used as a flux in making the soldered joints in the wiring. Such paste in time will creep over the insulated surfaces and cause an actual loss in signal strength.
THE resistance of any copper wire depends on its length and diameter. The shorter it is and the larger in diameter, the lower the resistance. Whenever you force electric current through the resistance of a wire you use up voltage or pressure.
ELECTRIC radio receivers of the modern type cause less trouble than older battery operated sets. Occasionally, however, something does go wrong. Chances are that even if you are familiar with the battery operated receiver, you will hesitate to fix the electric set.
You Begin Here by Building a One-Tube Outfit, and Add to It Later, Until You Have a Full Electric Receiver
ALFRED P. LANE
HERE is the first of a series of radio constructional articles that will appeal particularly to beginners. Each one will describe a complete receiver, starting with the inexpensive, modern one-tube receiver detailed on these pages. The next and succeeding articles each will detail the same receiver with additional parts to make it more powerful, so that the last article will describe a full electric set that will give good results on distant stations, show a satisfactory degree of selectivity, and operate a loudspeaker with good tone and volume.
Surprising Tests Explain Why Some Folks, Like Bees, Are Blind to Red and Green — How Our Eyes Catch Rainbow Hues
P. A. CARMICHAEL
THIS would be a dreary world if everything in it were either white or black, and man never saw any color but those. To look at a deep red rose and see only a cluster of blackness; to find the leaves of a tree all a dull white; to see a clear sky as a dome of granite gray; to get from the sight of leaping flames only the impression of fog—all this could happen only in a strange, fantastic world.
ONE of the oddest of treasure hunts ended at Saint Nazaire Harbor, France, the other day, after a successful test of new deep-sea diving apparatus of German design. It had recovered 2,000 francs in Belgian currency notes, a few coins, and a packet of papers from the captain’s safe in the derelict Belgian steamship Elizabethville, sunk in two hundred and forty feet of water off Belle Isle, situated south of Brest on the French coast, in 1917.
New Engineering Science Shows How to Develop Flying Harbors to Replace Mere r Landing Fields”
ROBERT E. MARTIN
A BAND was playing in a level, weed-grown field. Near by stood a group of prominent citizens, some of them mumbling the rehearsal of speeches soon to be delivered. Less prominent citizens and their children craned their necks to watch airplanes overhead.
The World’s Most Valued Feathered Tribe Fly in Vast Clouds That Hide the Sun. On Their Crowded Island Homes They Supply Fortunes in Farm Fertilizer
IT'S a queer, strange story about the most valuable bird in the world. The bird is never sold, never skinned nor dressed, its feathers have no use, its eggs serve no useful purpose except to raise more birds, no human being ever ate it, and it is rarely seen by the ordinary person.
How to Build a Simplified Model of the Speedy Old Buckeye State, a Stern-Wheel River Packet—The OneType of Ship Entirely American
RIVER PACKETS RACE ONCE MORE
E. ARMITAGE McCANN
ROMANCE has passed from Mississippisteamboatin’, but we can preserve a bit of it in our homes by building a model of one of the picturesque, speedy, and in many ways amazing old stern-wheelers that contributed so large a part to the upbuilding of the Middle West.
How to Lay Out, Saw, and Plane Boards and Make Doweled Joints —Hints on Furniture Building and Odd Jobs
EDWIN M. LOVE
A MOMENT of great anticipation! The home mechanic removes the clamps from his assembled radio cabinet and prepares to give it a last cleaning before applying the paint, varnish, or lacquer. What does his inspection show? Does he mutter under his breath and reach for the plastic wood, putty, glue and sawdust, or powdered-brick crack filler, or does he smile with pleasure as he finds every joint tight and the broad surface free from mars?
Yet It Can Be Made at Trifling Cost and No Great Labor with the Tools Found in Every Home
NOTHING sets off a fireplace better than an artistically designed fireplace screen. High prices are asked for screens that have a decorative, handmade appearance, but the actual cost of the materials in even the best of them is relatively small.
Mysteries of Northern Lights Explained—A $50,000 Search for a Meteorite—Discoveries and New Events in Astronomy
WHAT makes auroras? “The sun!” is the latest answer, given by Prof. Carl Stornier, Norwegian astronomer. Like a mighty siege gun bombarding the earth with buckshot, every sunspot that crosses the face of Old Sol pelts the earth with a hail of electrified particles.
AS THIS is written, a $50,000 party of men and machines is digging a hole in Arizona, looking for a fabled meteorite that may contain $500,000,000 worth of metallic nickel. The heavenly visitor they seek, believed to have buried itself beneath the great Canyon Diablo crater, three quarters of a mile across and 600 feet deep, is thought to be the greatest of a whole tribe of stray missiles that bombard us from the sky.
AS BIG as a silver dollar” is a romantic but not very satisfactory description of the size of the full moon. In order to compare heavenly objects and distances more accurately, astronomers use an ingenious and simple system of measurement.
ONE of the greatest astronomical spectacles of the near future will occur in September, 1932, when New York and New England will witness a total eclipse of the sun. Under favorable weather conditions, it will be seen by as many persons as that of January, 1925.
Magic Oil Films Let Industry's Engines Roar at Amazing Speeds
GEORGE LEE DOWD
MAJESTIC in its towering rigidity, the largest dock gate in the world swings open to admit an ocean liner. It is the most impressive feature of the new $35,000,000 Gladstone Dock, pride of Liverpool, England. Five hundred tons of steel, propelled by unseen machinery, recede silently and smoothly on massive bearings before the incoming vessel.
TRAFFIC from both ends of a narrow bridge wide enough for only one car, in Hampshire, England, is controlled by one man through an invention perfected by F. D. Blachford, a traffic guide of the Royal Automobile Club. The operator sits in a raised tower at one end of the bridge, and with a lever swings an indicator at the opposite end alternately to “go” and “stop.”
LONGER life and higher efficiency for electric toasters, irons, and heaters of all kinds is promised, according to the Westinghouse Electric and Manufacturing Company, by a new insulating compound just developed in its laboratories.
SO SUCCESSFUL have rubber pads proved as shock-absorbers and silencers for railroad trains, after a test on one rail length of a Federated Malay States railroad, that they are to be tried on longer stfetches of track. The rubber, which is made by special process, was found to deaden the sound of the clinking of rails within the coaches, and to absorb practically all vibration.
SOMETHING new in submarine rescues occurred in Italian waters the other day, when the undersea craft N-34, commanded by Lieut. Perrucchetti, became mired in mud at the sea bottom off Rome. Captain Perrucchetti, brother of the N-34 commander, was standing by with his new 2,000-ton submersible Ballilla, when he learned by undersea signal of the sister ship’s fate.
TELEVISION soon will play a part in solving a puzzling problem for the orchestra leader, according to Fritz Reiner, conductor of the Cincinnati Symphony Orchestra. A symphony to be presented calls, at one point, not only for a full orchestra on the stage, but also for a second orchestra hidden from view in back of the stage to provide faint strains of music as from a distance.
A CRASHING salvo from the U.S.S. Lexington's new eight-inch guns was the recent climax of four years’ effort by ordnance experts of the Navy to perfect the huge armament for installation on aircraft carriers. This photograph, first ever made of the Lexington s big guns and turrets in action, vividly shows how a carrier, “eyes of the Navy” through its covey of observation planes, may become a formidable battleship as well.
DO YOU know why winter is colder than summer? How deep scuttled ships sink in the sea? Why air in a close room gets bad? If you do, you cannot be caught in pitfalls of ignorance that trap many a man of more than average education, as disclosed by a recent New York survey of college graduates and others presumably well informed.
SINCE its $50,000 grant to Samuel Pierpont Langley to develop a flying machine, on which preliminary experiments were made in 1899, up to the present day, the U. S. Army has spent more than $1,000,000,000 on aviation, according to figures just announced by the aeronautics branch of the Department of Commerce.
NO LONGER need the occupants of an automobile rumble seat be at the mercy of the weather. A new cover in the form of a canvas hood unfolds at a moment's notice from a container on the back of the car. Its side and back curtains contain windows; the whole is made in one piece and is fastened with spring clasps.
A DOUBLE-DECK Pullman of the highways, providing berths for twenty-six people and hot meals during the long journey, recently was completed for service between Los Angeles, Calif., and Philadelphia, Pa. Each of its thirteen compartments has, among other conveniences, a wash basin with running water and a built-in thermos bottle to add to the comfort of the passengers.
FROM the sun must come the energy that will run the world for the next billion years, as it has in the past, Dr. R. A. Millikan, famous for his researches on star-born “cosmic rays,” recently declared. Harnessing the energy supposed to reside within atoms of matter, Dr. Millikan said, is “a childish Utopian dream,” and the idea that chemists might wreck the world by unlocking it “a foolish bug-a-boo.”
REMOVAL of curious wind towers that drove the steamship Baden-Baden, and substitution of a prosaic Diesel engine, has just marked the passing of the Flettner rotors as a commercial test. Anton Flettner’s idea was to utilize a part of the wind’s unbounded energy to drive ships; in short, to use spinning towers as sails to drive vessels.
MILWAUKEE firemen need no airplanes these days to get the thrills of sky riding. They have just come into possession of a new telescoping ladder, imported from Germany, which rises to a height of 100 feet in thirty seconds. Raised by gasoline motors, it is believed to be the tallest ladder of its kind.
A RESERVOIR which will add twentytwo billion gallons of pure water to the supply of Springfield, Mass., will result from the construction of the world's highest earth dam, forming a giant plug in a gorge of the Little River at Cobble Mountain, in the southwestern part of Massachusetts.
A CURRENT of icy water sweeping down the Atlantic with an average width of 110 miles—greater than the distance between New York and Philadelphia—that is the Labrador current as revealed by surveys made by the U. S. Coast Guard Oceanographic Expedition.
COMPLETE even to “ hot dog ” stands and traffic policemen, a remarkable model of the city of Detroit has been on display this year in towns throughout the state of Michigan. Its purpose is to teach the lessons of safe driving graphically and entertainingly.
TO PROTECT banks and depositors, George L. McCarthy, a former banker of New York City, has invented a new camera which photographs automatically every check cashed or deposited. The instrument can be adapted to any standard adding machine, making a photographic record of every check as it is listed.
A STRANGE bird that eats its own feathers is one of 188 specimens living in Porto Rico, reported recently by Dr. Alexander Wetmore, Assistant Secretary of the Smithsonian Institution. It is the Antillean grebe, a common bird of the island.
THE explosion of one hundred thousand pounds of dynamite, the biggest blast ever set off in the Pennsylvania coal fields, recently loosened more than 200,000 cubic yards of earth near Hazelton, Pa. It enabled steam shovels to remove the material above a rich vein of coal.
AN AUTOMATIC, invisible, and silent moving picture camera, housed within an innocent-looking telephone case, is designed to be the undoing of hold-up men. Its inventor, John E. Seebold, of Los Angeles, Calif., is shown below with the new apparatus.
A RAILROAD scale, so large it will weigh a 120,000-pound box car, and so sensitive it will show the change in weight if a sparrow alights on the car, has been built for the Chicago Belt Line by the U. S. Bureau of Standards. It will record down to one tenth of a pound.
WHISTLES will be tied to the tails of U. S. Army carrier pigeons to protect them from hawks as a result of experiments at the Signal School, Fort Monmouth, N. J. Made of featherweight bamboo, the whistles emit a shrill note as the wind passes through them.
WHEN this unit in a new traffic signal system installed on Ocean Avenue, Brooklyn, N. Y., says “go,” you can run for three miles through city traffic without having the lights turn against you. This is made possible by an electrical control system of synchronizing twentyone signals so that if a driver maintains an even pace of twenty-two miles an hour, he will never encounter a red stop light.
A MODEL steam locomotive which can pull its engineer, conductor, and three or four adult passengers along its miniature tracks has been perfected by a young machinist in Vienna, Austria. Its maker claims it is the smallest locomotive in the world that can develop such power.
A THOUSAND-TON, three-section bridge recently was moved down the Weser River, in Germany, from its position near Bremen to a point eleven miles away, where it was re-erected. Each section, 100 feet long, was mounted on two barges, which had been lowered with water ballast until they were able to move under the span.
THE three most hazardous jobs in America are those of the steel worker, the railroad yard worker, and the miner, reports the Bureau of Labor Statistics. Other hazardous occupations are glass blowing, slaughtering, and meat packing, and work in lumber planing mills.
CANADA now has more than 13,000 bison on government reservations. The largest herd, about 6,000, is located at Wood Buffalo Park, near Fort Smith, Northwest Territories. The second largest is at Wainwright, Alberta. It grew from four calves adopted by a half-breed, named Michael Pablo, after a slaughter of the animals in Montana.
WHAT is said to be the largest singlesurface kite in the world recently was made by small boys in a military academy in Los Angeles, and successfully flown. Five of the youngsters, ranging in age from twelve to sixteen, built the kite. But it took two dozen of them to hold it down once they got it up into the air.
SUGAR cane that, planted outside your house, would brush against your second-story windows, has just been discovered by American explorers in New Guinea. In the wilds where Prof. Jeswiet, leader of the expedition, found it, the stalks grow twenty-eight feet high.
THE world’s first two-story airplane hangars form part of the equipment of the Littorio Airport, at Rome, Italy, the southern terminal of the Vienna-Rome passenger planes. The machines taxi up to the second story on the 200-foot approach seen in the foreground of the picture below.
STEAM at the terrific pressure of 3,375 pounds to the square inch—four or five times as much as the highest steam pressure commonly used in factories— is produced in a new power plant at Charlottenburg, Germany. It is the first large-scale embodiment of the plans conceived by a British engineer named Benson.
THE belief that a protruding jaw indicates pugnacity is scientifically false, according to Dr. Fred Fletcher, American dental expert. “ The man with a squirrel-like jaw”, he says, “may be dynamite compared to one with a jaw like a mastodon.”
WHERE does the water in a waterspout come from? Meteorologists say the old idea that it is sucked up from the sea is wrong. Over bodies of salt water, the water in these spectacular whirlwinds has been found to be fresh. It is believed that the condensed vapor of the atmosphere through which the whirling vortex moves supplies this.
FISH oils, wood tar, and other similar products other than crude oil supply one third of all the “gasoline” used in the world today, according to a recent statement of Dr. Gustav Ègloff, of Chicago, research director of a large oil company.
SPECTACULAR fire tests to determine the flame resisting qualities of office safes are being continued by the U. S. Bureau of Standards, at Washington, D. C. A few weeks ago, as told in a recent issue of POPULAR SCIENCE MONTHLY, experts of the Bureau set fire to two condemned buildings in which they had placed three dozen safes and filing cabinets.
STUDENTS of the North Attleboro, Mass., High School have just assembled their own De Havilland plane as the first step in a new course in aviation. The Liberty-motored machine will be used for ground instruction only; pupils will “taxi” it across the ground and take it apart and reassemble it.
MODEL automobiles and airplanes, propelled by little rockets, form the latest toy craze in Germany. In this picture, a group of German children are watching one of the toy rocket cars get away for a flying start. It is patterned after the famous Opel machine, described in a previous issue of POPULAR SCIENCE MONTHLY, which recently attained a speed of 156 miles an hour on rails, without a passenger, before it leaped from the track and was blown to bits by the exploding rockets.
THAT hope for a cancer cure may lie in the hands of the chemist is a possibility seen in a new theory of the disease’s cause, recently outlined by Dr. Ellice McDonald, of the University of Pennsylvania. Germs do not cause cancer, according to Dr. McDonald’s unusual theory; instead, he claims, the cause may be and probably is excessive alkalinity of the blood.
NOW the humble ant comes to the aid of the prospector. How geologists may well pause in their surveying to test ant hills for desired minerals is described in a remarkable report of W. D. Johnston, Jr., of the U. S. Geological Survey, who tells of a recent attempt to map a valuable vein containing iron and manganese ore in the Little Florida Mountains near Deming, New Mexico.
RECENT reports of a strange sea monster washed ashore on a San Salvador beach, said to suggest the possibility that, it was a survivor of prehistoric reptiles known as ichthyosaurs, are discounted by Dr. J. W. Gidley, paleontologist of the Smithsonian Institution.
THE United States is the possessor of another volcano in Alaska, just discovered by the Pavlov Volcano Expedition headed by the American expert, Dr. T. A. Jaggar. He reports that the mountain is north of Canoe Bay and is 4,300 feet high. A small lake lies in its crater.
PICTURES sent by radio are played like phonograph records in a system of photo transmission and reception, invented by Capt. O. Fulton, and recently demonstrated in London, England. Both transmitting and receiving instruments employ revolving cylinders, not unlike the records of an old-fashioned phonograph.
AN INGENIOUS automobiledriven hoist, designed for small lifting jobs, can be attached to the rear wheel of a motor car or truck in five minutes, according to the maker, and will lift weights of 600 pounds as high as twenty-four stories. A single lever controls it and, should the motor stop with the load in midair, the mechanism is designed to lower the load gradually to the ground.
COL. P. H. FAWCETT, British explorer, whose disappearance in the Brazilian jungle has for three years been an unsolved mystery, probably died at the hands of hostile Indians. That is the conclusion of Commander George M. Dyott, head of a search expedition, expressed in a radio flash from out of the jungle that has just reached the world after being twice relayed.
IT WOULD take twenty-five average steamships, loaded to capacity, to carry all the tea used in the United States in one year. Fifty million people each year drink 30,000,000,000 cups of tea, costing seventy-five million dollars.
THE most disconcerting thing that can happen on the road is for the motor suddenly to cease firing, as though the ignition switch were thrown off. However, the manner in which the motor goes dead is a definite symptom that will help you locate the trouble.
BY-PRODUCTS of illuminating gas manufacture, which now serve only to gum up the meter in your cellar, soon may be turned to use in making plastics and perfumes worth many thousands of dollars a year. Investigating the clogging of meters, experts in the organic chemical laboratory of the U. S. Bureau of Mines have discovered that the trouble is due to gufn formation from the chemical compounds, indene and styrene, always present in manufactured gas.
ELECTRIC typewriting machines which automatically translate messages, into secret code or decode them, as fast.as a typist can write the messages, are the recent invention of Alexander von Kryha, of Berlin, Germany. The invention consists of three units—two typewriters and a central control box, all connected by a system of electric relays.
TWO advances in the telephone service of Berlin, Germany, have resulted from the perfection of automatic instruments. For the first time, long distance calls can be made automatically from a pay station by the dial method without having to call central first.
A RAILLESS steam locomotive, designed to haul trains over the solid stone roads of his native land, has been invented by Ahmed Nassery Shahpar, a Persian studying railroading in the United States. The locomotive resembles a tractor in construction and is said to be able to pull ten passenger cars, each loaded with forty people, at a fair rate of speed.
THAT the Gulf Stream—the warm current flowing eastward across the North Atlantic—turns around in the middle of the ocean and starts back toward America is the surprising phenomenon recently reported by the captains of two large trans-Atlantic ships.
A NEW lightweight, high-speed Diesel motor, burning a cheap grade of heavy fuel oil, is reported to have been perfected by a German manufacturer for use especially in motor trucks, buses, and railway motor cars. It may also be employed extensively as a stationary power unit—operating pumps and hoisting machinery and generating electric current.
TO TEST your knowledge of the world you live in, see how many of these questions you can answer. Correct answers appear on page 156. 1. What is the world’s largest island? 2. Where can natural rock salt be seen in the United States? 3. What is the driest place in the world?
THE RS-1, newest lighter-than-air craft built for the U. S. Army, is designed with an unusual heart-shaped bow, the purpose of which is to increase its stability while in flight. It will be used for training and practice flights, it has been announced.
I ATE air mail can be dropped directly into a letter slot built into the fuselage of a new type mail plane recently put into service on a western air route. United States Senator William E. Borah was one of the first to post a letter in this aerial mail box recently at the air field at Boise, Idaho, just before the pilot started up his engine and took off on a flight to Salt Lake City, Utah.
A DISTINGUISHING term for platinum, similar to “Sterling” for silver, is being urged by leading American jewelers to prevent unscrupulous manufacturers selling as pure platinum jewelry containing cheaper metals. The public, they say, cannot tell the difference between pure platinum jewelry and jewelry containing a mixture of platinum and palladium, which costs less.
IN ONE of the first public demonstrations of German gliders in America, Peter Hesselbach, holder of the world’s duration record of five hours for motorless flying with a passenger, recently had a thrilling escape from death at the edge of a high cliff near Highland Light, Cape Cod, Mass.
MILLIONS of tons of Wisconsin iron ore, in mines abandoned because of its high sulphur content, will be saved by a new smelting process developed by Prof. Richard S. McCaffery, University of Wisconsin metallurgist. In some mines the ore showed four times the amount of sulphur found in the output of successful mines.
TO MAKE the game more difficult, the British Golf Ball Committee has proposed the adoption of a new ball, slightly larger and lighter than those now used. It would cut down the length of drives. Golf authorities claim that while the proposed ball would have little effect on the game of professionals and champions, ordinary players would find their scores mounting.
A WINGED motor boat, called the Sea Flea by its inventor, George de Gasenko, Ukrainian engineer, made its appearance two years ago and was described in the pages of POPULAR SCIENCE MONTHLY. A new model of the invention has just been put through tests on Lake Teplin, near Berlin, Germany.
TWO new methods of combating seasickness recently have been brought to the aid of travelers who suffer on ocean voyages. One is the invention of “antiseasickness tanks,” installed on the larger steamers of the Hamburg-American line. These are in the form of great blisters along the water line of the ship.
THE latest wonder of agricultural experiment is a cabbage plant which produced six heads of cabbage in turn, one above the other. It was grown by Julian C. Miller, of Cornell University, who obtained the remarkable results by keeping the plant at high temperatures over a period of two years.
AS STRONG as twenty horses, yet so light that a girl can lift it, a midget airplane motor just produced by an aircraft manufacturer in Sacramento, Calif., is said to be the smallest in the world. It is a four-cylinder air-cooled radial engine weighing only sixty pounds with propeller.
THE world shrank nearly a fifth its size, as far as time required to travel around it is concerned, the other day when John Henry Mears and Charles C. B. D. Collyer, with “Tail Wind,” their white terrier mascot, landed at Miller Field, Staten Island, N. Y., in their folding wing Fairchild monoplane, the City of New York.
STREET lamps which shed striped light rather than a uniform glow are ideal for making pedestrians visible to motorists. This surprising fact was revealed in tests made by the Association of Lighting Engineers in England. In uniform strong light, it was found, an auto driver sees a pedestrian or other object mostly by the contrast in brightness between that object and the darker background.
PRACTICAL development of the radio beacon for aircraft, achieved only this year, is to be followed by its extensive installation on commercial air routes in the United States by 1930, according to the U. S. Bureau of Standards. Through its use, pilots for the first time will be freed of fog’s menace, for no longer will they be obliged to fly blind.
UNSEEN planes that make no noise may wreak havoc upon cities with their bombs in the event of future wars. This startling prophecy, made by a British aeronautical expert, is based on his declaration that already England, France, Germany, and Russia have nearly realized such a “ghost plane.”
FLYING across the continent from Los Angeles to New York in eighteen hours and fifty-eight minutes, Col. Arthur Goebel, 1927 winner of the Dole race across the Pacific to Honolulu, recently added two more records at once to his collection of laurels.
NINE tons of air mail left Lansing, Mich., in a single shipment the other day. Eighteen Stinson-Detroiter planes carried their weighty consignment of 350,000 circulars announcing a new model automobile, to Chicago, where the leaflets were sorted and sped by air to all parts of the country.
FOR two minutes, it looked as if a parachute jumper at Brooks Field, Texas, was doomed to remain in the air indefinitely. He had the recent novel experience, according to the War Department, of jumping from a plane into a powerful rising wind current that suspended him practically motionless at an altitude of 2,000 feet above the earth:
EVEN before the first air-rail line in this country went into operation in September, extending rail service by air between Chicago and the twin cities of Minneapolis and St. Paul, another part of the country saw an actual air-rail passenger transfer.
New Radio Beacons to Safeguard U. S. Airways; Unusual Planes and Remarkable Flying Records
women passengers for New York. They had come by air from Tulsa, Okla., to catch it and had flown low to identify the train as the one they wished to board. Elsewhere air facilities have been linked to advantage with other modes of travel. Germany has just effected an elaborate hook-up between its entire air and railway systems for the speedy transportation of freight.
STAMP collectors who have just placed the new five-cent air mail stamp in their albums, and others who use it, will be interested to know that the design is not an imaginary but an actual scene. Ten thousand feet above sea level, the world’s highest air beacon near Cheyenne, Wyo.
FOR those who are still uncertain just how to use the air mail and what advantages it offers, the U. S. Post Office issues the following information: Letters marked “Air Mail,” or stamped with air mail stamps, will be carried to any part of the United States at a usual saving in time of from four hours to two and a half days.
OVERNIGHT the mail and passenger network that spans the United States is undergoing mushroom development. This month should see the new air line of the Canadian Colonial Airways, between New York and Montreal, in operation despite delays in securing airports and arrangements for night lighting.
TRAFFIC signals direct planes landing and taking off at the Oakland, Calif., municipal airport. An airplane control station with a system of signals resembling those of a railroad has been erected on top of the administration building at the airport.
MOST great inventions and scientific achievements are, after all, merely object lessons in adding two and two to make four. The elementary principles of electromagnetism, for example, were well known to scientists for years. Then along came an artist named Morse who added them all together and got a result in the telegraph that revolutionized human communication.
IN AN eighteenth century laboratory, two pieces of metal, attached to a galvanometer, were thrust into a salt solution until they touched the leg of a dead frog. At that moment, the experimenter noticed the galvanometer move. He announced that the source of electrical current was frog’s legs.
ATTEMPTING a solo flight in his new airplane, Fred Stone, famous comedian, recently crashed and suffered severe injuries. If Stone were an ordinary actor, the incident might be dismissed as one of those unavoidable mishaps of flying training.
WITHOUT warning, a great new geyser recently roared from the ground in Yellowstone National Park, Wyoming. Today it is spouting steaming water, at fifteen-second intervals, sometimes to a height of 100 feet. Its present output of hot water would form a stream four feet wide and eight inches deep, flowing 120 feet a minute.
“THE earth was split off from the sun as a ball of fire of high temperature about 1,600,000,000 years ago.”—Dr. A. J. Nernst, University of Berlin. “Germany needs aerial patrolmen right now, and in a few years all Europe and America will have flying policemen.
And, Take It from Gus, He Got It!—A Short Tale of Two Autos
“I’M a mechanic, not a blooming auto salesman!” Gus Wilson grumbled as Joe Clark, his partner in the Model Garage, finished reading the letter he held in his hand. “Why be so grouchy?” grinned Joe. “Hamilton was a good customer and we ought to be willing to do something for him.
Or if You Break an Axle, There's a Simple Way Out of the Emergency—Ideas Which, if Heeded, Make Hard Jobs Easy
ONE man can pull a car out of a bad mud hole with a rope, a stake driven into the ground, and a wooden pole such as a fence post or a limb of a tree. Fig. 1 shows how it is done. The forked stick which translates the pull into upward motion is not absolutely necessary, but will help a good deal.
WHILE the oil gage on the dash indicates plugged oil pipes by registering excessive pressure, or oil-pump.failure by a low pressure reading, you may not happen to look at the gage. Figure 2 shows how to install an electric indicator lamp that will immediately call your attention to any oil failure in case you do not notice the warning of the oil gage.
THIS month’s $10 prize goes to J. L. Longino, of Pine Bluff, Ark., for his suggestion of the handy jack base shown in Fig. 3. Each month POPULAR SCIENCE MONTHLY awards a prize of $10, in addition to regular space rates, for the most useful ideas for motorists.
YOU can simplify the problem of slipping the jack under the rear axle by making the folding base for the jack, shown in Fig. 3. Cleats hold the jack in place. The length of the base can be made to suit the car and the hinges can be located to make the base fold into the tool box.
THE design for a simple, homemade cotter pin extractor that will pull the tightest pin with ease is shown in Fig. 4. A metal collar is welded near one end of a piece of drill rod. Then a sliding iron weight is fitted to the rod and the other end of the rod is pointed and bent into a hook. To use, hook into the eye of the cotter pin and move the sliding weight forcibly against the handle. A few hard blows are generally sufficient to remove the most stubborn cotter pin.
TWO U-bolts, some pieces of strap iron, and a front axle can be fitted together to form the emergency towing axle shown in Fig. 5. If the car axle has broken off at the wheel, this auxiliary axle can be bolted to the axle housing, making it possible to tow the car to a service station where the broken axle can be replaced.
Made of Wood and Worked by Strings —Four Other New, Inexpensive Toys
CHARLES H. TAYLOR
IN EVERY neighborhood there is a puppy. Even if he isn’t your own puppy and doesn't bury his bones in your garden, you find his antics amusing. By making a wooden copy of him—a puppy puppet—and burlesquing his tricks, you will have a lot of fun. This animated little dog (Figs. 1 and 2) is made from a block of white pine 1¾ in.
Gives New Thrill Even to Experienced Model Makers—Of Advanced, Featherweight Design, Yet Not Hard to Build
J. DANNER BUNCH
AVISON F. KOCH
PICTURE a tiny tractor monoplane flying very slowly, no faster than a person normally walks. Its large propeller revolves so slowly one can almost count the turns. On it floats, mounting higher and higher. It seems it will not run down. You have time to observe every flying characteristic, as if watching a slow-motion picture of an airplane flight or looking at some strange, slow-moving bug under a microscope.
Equipment Needed—Faceplate for Truing Long Work—Typical Set-Ups
HECTOR J. CHAMBERLAND
INTERNAL grinding in the up-todate shop is a daily problem. To do it properly requires attention and practice on the part of the machinist or toolmaker. And the equipment must be in fairly good condition. A four-jaw chuck, a faceplate, and, above all, a good internal attachment or spindle, are the most necessary and importantitemsof equipment.
Three Kinks to Save Your Time in Solving Daily Shop Problems
J. H. DOWNIE
MUCH work in which holes have to be related correctly to each other requires the locating to be done within perhaps two thousandths. While work of this kind can be done by precision methods—with buttons or with blocks and parallels—these procedures are slow, especially where there are a number of holes.
DO YOU know what? I wish the State Board of Education would empower me to hand out the degree of H. M. In England they might think it meant “His Majesty,” but here in America it means “Handy Man.” Remember, A. B. stands not only for Bachelor of Arts, but also for Able Seaman.
How to Give Antiques a Glowing Luster— Darkening New Patches—Hints on Waxing
R. C. STANLEY
WHEN all the necessary patching and repairing have been done to a piece of antique furniture and the old finish has been removed'as suggested in the first of these articles (December, 1927), we are ready to refinish the piece. You may wonder why the removal of the old finish should be delayed until after the patching has been done.
IN THE article describing the common six-block puzzle or “Chinese cross” in the May, 1927, issue, it was stated that the whittler could devise new combinations at will. Those who have tried to exhaust its possibilities have found the number running into the thousands without reaching the end.
ONE of the most annoying features about many a new home is the leaking of window sash. The casement windows so popular today are especially likely to let in water whenever there is a driving rain. Homes that have a very narrow roof overhang are often troubled because the rain beats directly upon the window glass.
Has 12-ft. Wing Spread and Looks Like Airplane—Releases a Parachute
RUDOLPH F. FISCHER
ONE of the most interesting kites I have constructed during the four years that I have been building and flying kites as a hobby is the one illustrated. It has a wing spread of 12 ft., and the over-all height is 6 ft. An alarm clock fastened to the frame serves to release a 4-ft.
AMATEUR painters who mix their own house paints with white lead-inoil paste can make plastic paint for textured walls and other decorative purposes by using the white lead as a base. The standard formula is: 100 lbs. of white lead base, 22 lbs.
Wooden Chucks Used in Turning Attractive Lamp and Stand
THE turned table lamp illustrated in Figs. 1 and 2 consists of two parts, the upright and the base. Before the upright can be turned, a hole must be made lengthwise through its center for the electric wires. This hole may be made either by boring through a solid piece of wood or by gluing two pieces together after first cutting a groove in each.
Paint Sprayer Built as Attachment for Vacuum Cleaner
WALTER E. BURTON
WITH a glass jar of the screw-cap type and a few other odds and ends, you can construct a satisfactory paint sprayer to be operated by the family vacuum cleaner. The use of such a sprayer makes painting a pleasure. It is especially suitable for producing a smooth, even finish with quick-drying lacquer.
ARROW points may be made as illustrated from brass or steel tubing, the outside diameter of which equals that of the arrow shaft. Place the tubing vertically in a vise, make two cuts from 5/16 to ⅜ in. deep with a hack saw at right angles to each other, and with a triangular file work each cut to a long V-shaped notch.
Assistant Superintendent of Manual Training, Los Angeles City Schools
Charles M. Miller
WATER yachts are tame beside these little runaways that rush along the pavements almost as fast as the wind. All kinds of sails may be used, and what with running before the wind or tacking, there are problems to keep the owner on tiptoe through all the windy play days of fall.
YELLOW pine woodwork is sometimes primed by painters with a mixture of white lead and red lead in equal quantities, thinned with raw linseed oil, turpentine, and benzole in equal parts. The advantage of this priming is that it effectively seals in whatever pitch there is in the wood and forms a durable base for the finishing coats, whether oil paint, flat paint, or enamel undercoater.
WHEN appeari nces are of no great importance, a ready-made storm sash often can be used, without any fitting, for a window not of a standard size. It is merely fastened on the outside of the casing as shown, by three or four screw eyes on each side and one in the center at top and bottom.
SMALL model airplanes are attractive novelties for use as ornaments, favors, or toys. The body can be whittled from a spare piece of soft pine, or a clothespin may be used. A good length is 2¾ or 3 in. and the breadth and depth in proportion. The wings are best made from very thin, soft pine.
TWO good dust brushes often can be made from a discarded floor push brush, provided the brush is not too badly worn. Saw it according to the accompanying diagram, trim away the hair on what are to be the handles, and dress the handles with a rasp or coarse file. While the handles are not centered, this does not MATTER.
A SUBSTITUTE for a rubber-stamp pad can be made by wrapping a length of typewriter ribbon around a piece of cardboard and fitting it into an old stamp pad box. When the pad no longer gives a clear impression, the outer layer of ribbon can be cut away.
THE home worker often desires to keep the door of a cabinet or cupboard closed without the use of a lock, a latch, or a surface catch of any kind. The best solution is to apply a friction catch, which is cheap, efficient, and, above all, easy to fit.
THERE are many places in a ship model—as in attaching deadeyes to the shrouds, fixing pendants to rigging blocks, and making eyes in the stays— where an eye splice would be useful, but owing to the small size of the majority of “ropes,” a true eye splice would be impossible to make.
SHIP model builders now have an opportunity to compete for prizes in a series of local or state contests being conducted to aid the work of the National Tuberculosis Association. The model must be a Phoenician, Greek, or Roman ship resembling the argosy that is pictured on the Association’s 1928 Christmas seals.
SHARPENING a spokeshave blade is a problem that often gives the home worker some difficulty. That is mainly because a blade is so hard to hold. A good holder, however, can be easily made from a block of wood as shown. The blade must fit tightly in the slot, which should be cut with a fine saw.
WHEN wood with knots in it is used for building purposes, as frequently must be done, the knots often fall out. Such holes are best repaired by means of a plug of softer wood cut to a size slightly larger than the hole and having a minute taper.
IN EVEN the smallest bathroom there is room for a corner cabinet of the type illustrated below. It requires only a 9 by 18 in. space on ea,ch wall in the corner. The same method of construction may be used, of course, for larger cabinets. While common soft woods, painted or enameled, serve for a bathroom, highly finished cabinet hardwoods would be appropriate if the cabinet were to be placed in a bedroom or living room.
HOW to fasten a baby’s gate temporarily to a door or a porch railing without unnecessarily damaging the woodwork or going to too much trouble, is a problem that is frequently encountered. One simple solution is that shown above. The gate is pivoted on a long wood screw in such a way that it can be instantly tipped up out of the way.
RECENTLY I made several ásh trays and other novelties from unserviceable radiator caps, using three ⅝-in. steel balls for the feet of each. First determine the location of the feet, dividing the distance between them evenly, and drill ¼-in.
MY HOUSE is a warmly built six-room cottage. A hot water system using by-product coke furnishes the heat. Six or seven years ago I adopted the plan of banking the fire at night with ashes. Then the thought came that a metal cover might be the best thing to use, since it would possess all the good qualities of the ashes and none of the bad ones.
MAKING an arbor is a school shop project that involves the use of micrometers in turning to accurate dimensions. Arbors of other sizes than that illustrated may be made. The material is soft steel. The tools needed are: Hack saw, scriber, hammer, center punch, combination center drill, lathe dog, engine lathe, 6-in.
FROM a pair of old pliers with broken cutting edges and worn-out jaws, a machinist made an ideal tool for holding any length of round stock of small size for soldering,hardening, and tempering. After thoroughly cleaning the surface of the pliers, he bent over a length of flat stock and “sweated” it to the jaws as shown above.
ORDINARY tin boxes, in which various goods are packed, serve well as “tote” or carrying boxes in the shop after they have been emptied of their original contents. Special boxes of this kind are illustrated. Each of these has only one handle, made by passing a length of strap through punched holes in the side and tying the ends.
How should one prevent a recurrence of the sticking?
C. A. K.
Paste this Home Workshop Reference Sheet, including the head above, in your scrapbook in the section marked windows. (Nov., 1928, POPULAR SCIENCE MONTHLY.) WHEN the lower sash of a doublehung wooden window—that is, an ordinary sliding window—sticks, how can it be opened and remedied ?
HOW would you remove the lower sash of a double-hung window for replacing broken sash cord or glass ? 1. Remove the left stop strip A by preference, as this will allow right-hand work. If the cord on the right side is to be repaired, however, the strip on the right side (A1) should be removed.
ONE of the hardest tasks for the beginner in ship model making is to give his handiwork the weatherbeaten appearance so often desired on models of galleons and other ships of the fifteenth, sixteenth, and seventeenth centuries. The method used by the writer in painting more than a dozen ships sold by him to friends and neighbors is as follows:
WHEN a ukulele, banjo, mandolin, or similar instrument will not produce correct tones, I have found the cause to be almost invariably one of the following: Loose pegs, defective ' strings, frets not accurately placed, or nut too high from the fingerboard.
IN MAKING the book ends illustrated, I used ½ in. thick soft white pine— hardwood would have served as well or better. A piece of old lead drain pipe was melted to give the necessary weight. The ship itself is cut from a piece 5½ by 6 in. The waves, which form the base of each block, are cut from five pieces, the largest ½ by 1¼ by 5½ in.
AMATEUR woodworkers and even carpenters find it difficult to plane the edges of long boards reasonably straight, as when a number of pieces have to be joined to make wide shelving. I find it a great help in all such work to stretch a line or wire taut on top of the bench and drive a row of finishing nails partly into the wood at one side of the line, close to but not touching it.
A NGLES of 30, 45, and 60 degrees are often encountered on valve seats, cutters, and reamers, but the faces are usually so small that it is difficult to determine instantly what the angle is. If marked as shown in the illustration above, the calipers may be used as a protractor for measuring such angles when extreme accuracy is not a matter of concern.
BRUSHING lacquer is now being used by some pattern makers to coat wooden patterns in place of shellac. Metal patterns which have not been protected by being sheradized are also being lacquered. The lacquer resists moisture better than shellac and lengthens the life of the patterns; it is said also to give a smoother finish so that less patching of the sand mold is necessary and better castings result.
MY BUNGALOW, which was not built with an eye to the confusion of intruders, has been entered no less than three times in two years. The vulnerable point was the door of a basement garage at the rear, held by inside bolts and a “night” lock attached to the inside.
"SAY, George, I need a little help on a motor over at the shop. I wonder if you will come over and give me a hand. I’ve been making some changes and I want to use one of the motors in a different place, where it has to run in the opposite direction.” Anson, my machinist friend, was speaking.
THE threads on the lower or bearing end of small grease cups wear in time to the point where they easily become crossed upon applying the cup. The chances are then greater of the cup’s being loosened by vibration and becoming lost. Lay the worn part over the peen of a hammer as shown and strike it with a block of hard wood.
THE desk attachment illustrated can be easily built at slight expense and attached to almost any ordinary chair. For the top, glue to a piece of 1 by 6 in. pine 2 ft. 6 in. long, two widths of 1 by 10 in. stock 1 ft. 5 in. long, so that the desk can be shaped up to a width of 1 ft.
TINY log cabins for use either as mantel ornaments or as toys can be made quite easily from branches of trees, or wooden curtain rods or dowel sticks. I made the cabin illustrated of ⅝-in. curtain rods—14 pieces 11 in. long and 18 pieces 7 in.
PLASTER of Paris statuettes or busts can be cleaned by dipping them in a thick liquid starch, allowing them to dry, and brushing off the starch. The greater part of the dirt is removed with the starch and in many cases the surface of the plaster looks as clean as when it was new.
HOW British scientists used the faint air pulses from German guns to locate and destroy them was told the other day by Sir William Bragg to the British Association for the Advancement of Science. It was a problem, he said, of finding some way to time the arrival of the pulse simultaneously at several points, so that surveying experts could locate the gun and give British artillerymen the range.
RESEMBLING in appearance the “igloo” habitations of Arctic tribes, new powder magazines developed by the Navy have demonstrated their safety in recent tests at the Indian Head, Md., proving grounds. In one experiment, a ton and a half of T N T was placed in one of the low-domed, concrete structures and exploded.
1. The largest island is Australia. It has an area of 2,974,581 square miles. Greenland is second largest, 827,300 square miles. 2. The most important area is in western New York, especially near the town of Warsaw. Rock salt has been mined here for many years.
ULTRA-SHORT radio waves, of the type recently used in experiments at the General Electric Company’s Schenectady, N. Y., laboratories and elsewhere, may have new value in the treatment of disease, Prof. Esau, of Jena, Germany, told the German Wireless Association a short time ago.
WOULD a head-on collision of the earth with a comet—a perfectly possible, though unlikely, occurrence—spell the world’s doom? “It might be disastrous—or it might be more spectacular than dangerous,” says P. Davidovitch, of Harvard Observatory.