If you cant answer the questions below, turn to the page indicated
1. Has blood pressure any connection with auto accidents? (. 51) 2. Who will transmit for you, without charge, a radio message to anyone, anywhere? (p. 39) 3. What kind of a cold is not contagious? (p. 28) 4. For what is Sir Isaac Newton famous? (p. 34)
THE family had finished its dinner early. Harry Wilson had about exhausted his evening paper and was ready for whatever might turn up. His wife was upstairs going through the nightly tussle with two lively youngsters, getting them stowed away to bed.
THE Booklets listed below will help every family in laying out a financial plan. They will be sent on request. “Ideal Investments” is the designation universally accorded Smith First Mortgage 6½% Bonds which carry attractive tax refund features.
IT IS a fine tool; it represents good value; it will give you satisfactory service, ’’— this is what the Popular Science Institute of Standards’ insignia of approval tells you when you see it on a tool advertisement. Such statements mean much or little according to what lies in back of them and the tool user will rightfully ask, “How do you know that?’’
US and Joe, those inimitable garage experts who are with us each month, felt justified, a few issues ago, in roundly blaming the woman who “drives” from the back seat. Letters from many readers agreed with them. But listen to Mrs. L. S., of Walton, N. Y.
Inventions That Might Have Prevented the Tragic Loss of the Crew of the S-4 That Fought for Life at the Bottom of the Sea
JOHN WALKER HARRINGTON
IN A gale-swept bay of the New England coast one of the greatest rescue fleets ever mobilized closed about the spot where forty men had been buried in a crushed coffin of steel, flung to the bottom of the sea. The living tomb was the submarine S-4. one of the largest of Uncle Sam’s undersea fighting machines, which had been rammed and sunk by the U. S. destroyer Paulding.
CUYABA, Brazil.—Freed from romantic captivity as the living idol of a remote Indian tribe hitherto unknown to science, Col. P. H. Fawcett, the noted British explorer who in 1925 vanished into the jungles of Matto Grosso, is now being brought out to civilization.
What Happened When the Big Air Liner Took Its First Trip—A Story of Ingenuity, Parachutes –and a Girl
ANDREW A. CAFFREY
JUST mention all metal aircraft construction and you are sure to start some sort of argument. But ask for the best all metal pilot in the game, and the flying world points him out—Jack Page. This yarn has to do with an all metal combination—Jack and his all metal airliner, the Pacific Gull.
How Tiny Bodies in the Blood Protect Some Men Against Illnesses That Others Cannot Survive
FOUR men of Buffalo, returning some years ago from a convention in a neighboring city, were stricken with typhoid. The infection was traced to the water they had drunk in the convention city. Why was a fifth Buffalo man who drank the same water apparently immune to the onslaughts of the typhoid bacteria?
Lindbergh’s Plane Good as New After Flying 35,580 Miles
WHEN Col. Charles A. Lindbergh touched the soil of Central America on his latest “good will” hop, his famous mechanical partner, the Spirit of St. Louis, had carried him, altogether, 35,580 miles—nearly equal to one and one-half times around the globe! And this without sign of faltering, and with only a few minor repairs.
Lumberjacks Risk Lives Playing with Twenty-foot Jackstraws And Dynamite to Keep Timber Moving in Lakes, Rivers and Rapids
THE drive! Pulp logs—fourfoot lengths of spruce destined for the pulp crushers of the voracious paper mills down river. Saw logs— twenty-foot lengths of pine for the band saws of ever-hungry mills. Thousands and thousands of feet of rushing timber, wet and slick, sometimes tossed half hidden by sheets of white spray into the thin spring sunshine, sometimes tumbled end-over-end down breath-taking rapids by the fierce swirling waters of wellnamed Rapid River.
Dramatic Story of Modern of Miracles Which Vastly Increase Safety of Land, Sea and Air Travel
FRANK PARKER STOCKBRIDGE
SPARE, blue-eved man with a close-cropped, white mustache stood on the roof of a tall building on the Brooklyn side of the East River and looked across a mile and a half of space at the skyline of Manhattan. Except for a few illuminated windows here and there, behind which workers lingered at their tasks, the battlements of downtown New York were black against the midnight blue beyond the Jersey hills.
May be from Heavy Meals, Smoking, Kissing, or From Your Neighbor—Some New Discoveries about Our National Malady
P. A. CARMICHAEL
THOMAS A. EDISON has said that the American people eat too much. The great inventor speaks with authority; he knows the importance of right eating. To the fact that he has long kept to a light diet he attributes much of his ability to work more hours a day than most men.
How Uncle Sam's Sky Glassrooms Are Teaching Awkward Fledglings to Become Great Flyers
MAJ. GEN. JAMES E. FECHET
FIFTEEN hundred feet above Brooks Field, San Antonio, Texas, a biplane skidded uncertainly in wide-sweeping circles. In the cockpit a goggled young flying cadet, right hand clutching the “stick,” feet moving gingerly on the rudder controls, struggled in the grip of a strange predicament.
Bitter Dispute Divides French Archeologists—Are Carvings Dug Up 1o ,000 or Only 1o Years Old?
GEORGE LEE DOWD, JR.
THREE thousand so-called prehistoric relics, dug from clay two feet under the soil of a peasant’s farm in the hamlet of Glozel, France, today have divided French archeologists into two bitterly hostile camps in a controversy to determine whether a fascinating new chapter shall be added to the early history of mankind.
DOWN a Michigan road, not long ago, rattled a dilapidated "tin lizzie." Over the steering wheel crouched a tall, gaunt, grayhaired man; a small boy at his side. Henry Ford was the man. The car was a new Ford, secretly built and disguised under a body of ancient vintage.
The Story of a Farm Boy Who Built Queer Toys, Made the Universe Hang Together, and Became One of the Supreme Discoverers of All Time
NEWTON’S SIX GREATEST WORKS
ARTHUR A. STUART
AN ENGLISH farmer’s son, rather dull in his early school days, who carved his name on a stone window sill when he should have been conning his lessons and spent his leisure at home in making doll furniture for girls and queer toys for himself, received the homage of the civilized world during the last year on the two hundredth anniversary of his death.
A Close-Up of Mechanical Magic Behind the Screen Revealed in This Romance of Courage and Ingenuity
S. W. NEWMEYER
DON KENNEDY, red-headed young director of the comedy section of Popular Players’ West Coast Studio, and Judy Burke, his script girl, shared the high ambition of some day producing a big feature picture. Toward this goal Judy had written an excellent scenario, while Don had invented a new photographic process by which action photographed in a studio might be superimposed on backgrounds taken anywhere in the world, thus effecting enormous economies in production.
Appeals for Flood Relief News from Explorers and World-Wide Signaling All the Amateur’s Work
ALDEN P. ARMAGNAC
IMAGINE a hobby so fascinating that it can keep a boy from his meals—and his father, unable to stop him even by demolishing his radio transmitting set, has to appeal to the Government for aid! That happened the other day. Eric H. Palmer, of Brooldyn, N. Y., sat down and penned an urgent letter to the Federal Radio Commission at Washington, D. C. “Please revoke my son’s license to operate his amateur station 2ATZ,” the father wrote.
TO LET the ocean waves do the work of man by providing hydroelectric power, Lieutenant Commander Lybrand Smith, of the Navy Department’s Bureau of Engineering, has designed an amazingly ingenious battery of hydraulic rams, illustrated by this schematic drawing and the accompanying diagram.
How American Navy, Firing “Off the Map” Shattered and Set Aflame Germany's Vital Rail Centers,Hastening Victory
REAR ADMIRAL CHARLES P. PLUNKETT
ON THE war map you stuck pins in ten years ago, Laon was northeast of Soissons, with so many radiating railroads that it looked like a spider. Gun No. 1 cut off the spider’s legs in eight days’ bombardment, though news came at the end of the first day that the German retreat from before Laon was commencing.
Waves of Radio and of Light and Sound Guide Planes and Steamships Through Blinding Vapor
NORMAN C. McLOUD
WERE nearing the American coast in a fog which had blanketed us a good part of the way across the Atlantic. For three days our ship had barely crept, continually sounding its mournful warning whistle. Now a chorus of whistles from other craft indicated we were in the vicinity of New York harbor. But wdiere?
Chemists Already Make Bituminous into Medicines, Dyes and Fertilizers and May Make Tile and Rubber
A. C. FIELDNER
EVERYONE who has tried to keep clean in any neighborhood when soft coal was burned will be interested to know that research chemists in the Pittsburgh Experimental Station of the U. S. Bureau of Mines are busy, at the present moment, making it smokeless.
Skull of California“ Ape Man" May Be Half Million Years OldHeart's Electricity Photographed—“Death" of the Sun Predicted
Advances in many and widely diverse fields of scientific research, discoveries, inventions and theories, important because of their bearing on everyday life, are chronicled each month in these pages. Professor Jeans calculates that our sun is perilously near the “white dwarf” stage. Any day it may totter. But, since a day in the universe may be millions of years, this is nothing to worry about.
AGREAT British astronomer. Professor J. H. Jeans, says the sun is ready to collapse at any moment. When it does, the earth will be frozen so cold nobody can live on it. A French astronomer, M. F. Baldet, finds evidence that the planet Jupiter, largest in the sun’s family, is shooting enormous volcanic bombs into space.
WORKMEN, laying a sewer in Santa Barbara, Calif., found a skull buried eighteen feet a few weeks ago. To them it was only a somewhat gruesome mass of bone; but to Dr. A. H. Ousdal, an archeologist, it was a rare historic document. For his examination indicated, he said, that the skull was the nearest thing so far found to the “missing link” connecting man and the apes with common ancestry.
Oil Engine and Cheap Helium May Start New Flying Epoch
AVIATION engineers of England have perfected a new airplane engine of the Diesel type, which burns heavy oil in place of gasoline. From the Fixed Nitrogen Laboratory, at Washington, D. C., comes the statement of Dr. Frederick G. Cottrell, expert on the chemistry of the atmosphere, that helium gas may be obtainable from the air in unlimited quantities.
A CAMERA, a cat, a bulldog and a nursery of babies were assembled recently in the psychological laboratories of Johns Hopkins University to determine what sort of stride babies use when they creep. The answer was: Babies are trotters. Watched by the camera, the cat and the dog proved to be pacers, the weight of the body being alternately borne by the two legs on each side.
PHOTOGRAPHY’S latest achievement, announced by Dr. C. E. Kenneth Mees, Director of Research in the Eastman Laboratories, is in recording faint electric currents of the human heart! The process, employing a string galvanometer, a delicate instrument for measuring electric currents, promises usefulness in diagnosing heart ailments.
THE reason some auto drivers constantly have accidents while others have little trouble may be largely a matter of blood pressure. Dr. Walter Y. Bingham and C. S. Slocombe, psychologists of the Personnel Research Federation, New York City, have just completed experiments in which they find a definite relation between health and motor accidents.
MUMMIES of long-forgotten men of the Far North, older than those found in ancient Egyptian tombs, will be sought by an expedition of the American Museum of Natural History, this spring, exploring the Arctic Coast of Siberia. The remains are those of primitive Mongolians, believed to have been the first settlers of North America.
SOME months ago a German chemist, Dr. N. D. Zelinsky, was making chemical analysis of certain insects. The process involved covering them with powdered copper oxide and heating them in small platinum crucibles in an atmosphere of carbon dioxide.
THE man who drives with one hand will find that he may use the other to reach for a sandwich and a cup of coffee in a5“road yacht” developed in London. The vehicle, which looks like a large metal bug on wheels, is the latest in touring luxury. Speed of forty-five miles an hour may be easily attained. An electric “galley,” completely fitted lavatory, two sleeping cabins, book shelves, writing tables, and a radio complete the equipment of this automotive innovation, which accommodates five persons.
WHAT is thought to be the largest meteorite preserved intact for which the date of fall is definitely known is being studied by experts at the University of Iowa. It is a 110-pound chip from a celestial visitor that exploded about fifteen miles above Iowa City, la., according to Prof. Charles C. Wylie, one of the investigators. The chip buried itself in hard clay.
A FLOATING bottle’s journeys ended the other day when William Hannapin, walking along the west coast of Ireland, picked it from the water and read the note it contained, “No. 1059. Please return to William Beebe, New York Zoological Park; or to the Hydrographic Bureau, Washington.”
IT’S harder to name a new animal than a new baby, according to Dr. C. W. Stiles, secretary of an international commission that has sought for years to work out a standard naming procedure. The creature runs the risk of being named several times by independent discoverers.
A LONG steel cable, drawn at high speed and fed continually with wet sand, cuts through solid rock in a new type of quarry saw developed by Dr. Oliver Bowles, of the U. S. Bureau of Mines. Tiny grains of sand, dragged across the rock face, serve as abrasives to groove it at a rate hitherto unknown.
Swastika May Trace Races To Lost Pacific Continent
MANY thousands of years ago there stood in the Pacific Ocean a continent where thrived a remarkable civilization. In a tremendous earth upheaval the continent vanished, swallowed by the waters. But before the catastrophe, adventurers from that lost land drifted to other continents and left their marks.
HOW would you like to go for a motorcycle ride on the river? E. A. Cullum, pictured below, thinks river cycling a plausible idea even though his first attempt to cross the Thames resulted in the sinking of his queer machine and the second fared little better. His vehicle consists of a motorcycle built into a float of the sea sled type.
SKATES like those seen below would allow you to drink that extra cup of coffee and still get to work with time to spare, for the remarkable speed of thirty miles an hour is claimed for them. The effective motive power for these upto-date “seven-league boots” is furnished by the downward step of the skater through a ratchet gear wheel.
CLAY roads are kept moist, firmly elastic, and free from sun-dried cracks in Michigan by the addition to the clay used in building them of an odd chemical that absorbs water from the air. The resulting compact mass stands up well under ordinary traffic, according to A. L. Burridge, of the State Highway Department, who developed the novel idea.
THESE seals and sea lions are said to be experiencing a new sensation, for heretofore, it is declared, this type of animal has never been caught and brought in writh nets. The picture below shows a small schooner off the west coast of Mexico with what is reputed to be the first haul of this kind, made with netting of tremendous strength.
WITHIN the concrete paving of a five-mile stretch of Colorado road, just laid, lies $20,000 worth of gold. Highway engineers found that rock from mine ore dumps was the nearest at hand and most plentiful for mixing the concrete. Despite the quantity of gold it contained, there was not enough to pay for the expensive process for its extraction.
HAVE you a dump heap near your home? If so you might lay out a golf course, for therein are the “makin’s.” Pipe fittings, a number of loose bricks, and a variety of crockery went to form hazards for this sporty nine-hole course that a large gas company at Hell Gate, N. Y., laid out in its front yard. Upon these links the player must be careful not to send his ball out of the yard with an unexpected bounce off a piece of steel tubing.
WATER holds back water in an amazing new type of dam, said to be extremely economical to construct, proposed by French engineers. If successful tests of a plaster model are confirmed, a 230-foot dam will be erected near Marege, France. Instead of one solid masonry wall, the dam will consist of five thin concrete ones across the Haute-Dordogne Valley. Each, looking down the valley, is lower than the last, the farthest downstream being only forty-six feet high. When water is running over their tops they will appear like cascades.
PUTTING the moon to work for us is the not far distant prospect held out by the National Geographic Society, by the use of the same force that creates the tides and that makes the great liner Leviathan weigh ten or twelve pounds less when the moon is directly over it. “In years to come,” the society announces. “this moon-force may be harnessed to create power; already plans are under way for the construction of tidal power stations. ”
FLEET greyhounds vie for speed records as they pursue the “electric hare” of a new racing outfit, designed by an English inventor and recently successful in tests at Beddington. Though in design it resembles the standard race tracks that have popularized greyhound racing in Britain, the latest apparatus is portable and can be set up at any sports meet or fair.
DO WE need another Panama Canal? Although the great waterway is now operating on a sixteen-hour schedule, it may eventually require constant use, indicates a report of the governor, M. L. Walker, to the Secretary of War. During the last fiscal year shipping passing through the canal set a new high record of 5475 commercial vessels alone, not to mention other craft that brought up the average to nearly seventeen a day.
THAT the real inventor of the gasoline automobile was Siegfried Marcus, Austrian mechanic, is the contention of authorities who plan a statue in his memory at Vienna. As early as 1864, it is said, the man who won the Golden Cross of Merit for incandescent lamps and rotary pumps he invented made the world's first motor car. Eleven years later he perfected a model and carried passengers.
HARD surfaced highways are the most economical to motorist and town or state alike, according to W. H. Rhodes, New Orleans engineer. “The efficiency expert of a tri-state bus company,” he recently told the American Society of Municipal Improvements, “found that their heavy busses running over gravel cost two cents a mile more in tires than those running over asphalt.
WHEN cotton manufacturers sought to find new uses for their fabric, they decided to make wheels of it! Now these odd wheels, used on hand trucks to enable them to roll quietly through factories and offices, have proved successful in recent tests conducted at the War Department.
WITH average luck, you might expect your car t J last seven years, concludes Prof. C. E. Griffin, of the University of Michigan, who investigated the history of 100,000 cars. Half of them were out of commission at the end of seven years, but, after twelve years, more than 5000 were going strong.
THE great Pacoima Canyon Dam, three hundred and eighty-five feet high, six hundred feet long and a hundred feet thick at the base, considered one of the outstanding engineering feats of our time, will protect California's fertile San Fernando Valley.
TREACHEROUS at ail times, the legend-famed Irak Desert of Mesopotamia becomes a sea of mud in rainy seasons, and motor cars attempting to cross it are trapped times without number like flies on flypaper. But mail must in spite of all circumstances traverse the forbidding wastes between Bagdad, in Mesopotamia, and Beirut, Mediterranean port of Syria.
FOR the aid of trans-Atlantic flyers, the Navy Department’s hydrographic office has commenced the publication of “pilot charts of the upper air,” showing the most feasible aviation route for each month. They will be issued throughout the year.
FASHION designers seeking new patterns may well turn to Nature, as the unusual photograph below shows. It is the chance shot of a photographer who saw in the curious mosaic of circles and ovals of an oil ditch an out-of-theordinary camera subject well worth recording.
TWO thirds the size of the old currency, the small new dollar bill just designed by the U. S. Treasury is expected to save the Government four million dollars a year. You will soon be carrying the new-size notes, which were scheduled to be ready by the time this magazine is printed—although it is said that half a billion will be printed before the first is issued.
CIVILIAN inhabitants of Moscow, Leningrad, and other Russian cities— men, women and children—are now being provided by the government with “personal gas masks” and instructed in their use, according to reports. “It is our duty to supply them not only to every soldier but also to every working man and inhabitant of the districts behind the war front,” Commissar of War Voroshilov told the Fourth Soviet Congress, urging that in the unlikely event of war Russia should not be unprepared.
NO, YOU’RE wrong, this is not a picture of an explosion, although it may look like one. In reality, the photograph was made when wreckers demolished several ancient buildings in Jersey City, New Jersey. The old structures were almost 100 years old and very solidly built. The crash when they finally surrendered to the razers’ sledge hammers was heard several blocks away.
HEATING plants on the roofs of buildings may come within a few years, H. Leigh Whitelaw, of New York City, recently told the Pennsylvania Gas Association. Skyscraper owners, íe said, would increase their profits by leasing the basements that now hold the heaters. The technical difficulties of adapting heating systems to the topsyturvy plan could be overcome, he says.
FIRST place in the international egglaying contest just conducted by the Washington State Agricultural College has been won by ten Barred Plymouth Rock hens owned by Prof. H. B. Densmore, of the University of Washington. In one year his pen of hens laid 2807 eggs. This is said to be the first time in poultry history that Plymouth Rocks have beaten all other hens, including Leghorns, which took second place.
NOW the guests of a New York City hotel have radio programs on tap through the touch of an electric switch. The entire hotel has just been wired for radio, and two central receiving sets are on the thirty-first floor. Nearly all the 1600 rooms have loudspeakers.
“Seeds” of Metal Salts, Put in Strange, Poisonous Solutions,Sprout Like Sea Vegetation
NOW artificial plants are grown in test tubes through the chemist’s magic. The photographs on this page, made by Dr. E. Bade, show how closely these chemical plants resemble nature's own products. Pills made of salts of metals are the “seeds,” which are dropped into solutions of sugar or salt and other “nutritive” substances such as saltpeter and yellow prussiate of potash, a deadly poison.
FASTEST of toy automobiles, says the maker, is a new lightweight car for the children. Among its novel features are a safety system of double brakes and a patented bicyclelike sprocket that enables the youthful driver to go forward, reverse, brake and coast at will.
IF YOU need a faithful, efficient house servant, not subject to human failings, try a baboon. That is the startling advice of Prof. F. A. Lindemann, of Oxford University, England. In twenty years, he declares, there need be no servant problem.
GREAT, undeveloped power resources —the smoldering fires within the earth—have just come in for attention with a recent survey of the California natural steam wells. Two experts of the Carnegie Institution, Dr. E. T. Allen and Dr. Arthur L. Day, have reported the results of the first thorough investigation of its kind in America.
EVERYTHING new in aeronautical science is said to be incorporated in the Navy’s latest seaplane—a giant with a cruising radius of 3000 to 4000 miles that could conquer the Pacific! The first of these “PN-11” planes, secretly built at Philadelphia, has just been completed, and twenty-five more are to follow.
TO TELL the time, without turning in bed, an English inventor had devised an apparatus that projects to the ceiling a magnified, illuminated image of his watch-face! He slips his watch into the device before retiring; a touch of an electric switch conveniently located on his bed at any time during the night and the hour is indicated above him.
ENGINEERS recently laid a unique floating roadway when they constructed a $275,000 underpass to avoid a grade crossing at South San Francisco. To pass beneath twelve main-line railroad tracks, the road dips three feet below sea level. It rests upon a mud and water foundation alone; six hundred steel anchors hold it in place.
NO MATTER how hot it is, you can skate and coast as in midwinter on a new kind of “ice” devised by German chemists, now installed in a Breslau exhibition hall and skating rink. Although, it is said, you can slip and fall on it as effectively as on the natural substance, the new compound does not melt even at a heat of 208 degrees!
Planes Use Costliest Wood At $600 for Thousand Feet
PROBABLY the highest-priced lumber that comes from a log, lumbermen say, is the hand-picked Sitka spruce used in the building of airplanes. Not every log will supply the quality demanded— a clear straight-grained spruce of the highest standard. Only a half dozen mills in the Pacific Northwest can supply the rare wood, and it takes from three to six weeks to assemble a carload.
IN A short time, what is said to be the highest bridge in America—if not in the world—will be completed. It spans an Idaho river north of Twin Falls, at the tremendous height of 490 feet. This unusual photograph below shows the structure being thrown up across the ravine.
WHAT is said to be a speed record in home construction was achieved recently at Forest Hills, N. Y., where architects and engineers saw workmen erect the steel framework of a twostory dwelling in three hours and twenty minutes! It was a demonstration of a new system of house building by the use of standardized steel members similar to those used in constructing skyscrapers.
YOU can’t be carried past your floor in the latest type of automatic elevator, recently introduced in New York and other American cities. On the ground floor the operator presses a numbered button for every stop desired. Then he starts the elevator; without further control, it shoots upward and stops at the first floor called for.
WHEN the weather is on its bad behavior, the open car loses much of its attractiveness. It’s a quick change to a closed one with a remarkable new convertible type of automobile recently exhibited at Westminster, England. From the rear compartment, as seen below, unfolds a substantial top that is quickly set in place and made weather-tight.
THIS magazine is always glad to answer inquiries of readers concerning all subjects within its scope and to furnish names and addresses, whenever possible, of the makers of articles described in its pages. Replies are made as promptly as possible in view of the time required for research, and every effort is made for absolute accuracy.
A GLOWING, gigantic bubble of gas that shrinks and swells” is the astronomer's latest description of Mira, a remarkable star that graces the celestial equator. Recent observations with the aid of a light-recording instrument, devised by Prof.
BY THE lightest touch of your hands, through a marvelous new mechanical device, you have power enough to steer a ship or aim a huge gun. These are the latest uses seen for the “torque amplifier,” developed under direction of H. W. Nieman at the Bethlehem Steel Works and described in the January POPULAR SCIENCE MONTHLY.
UNUSUALLY bright children are neither queer nor likely to become so later. That is the opinion of a number of authorities. Clever children, they agree, generally come of distinguished parents, have unusually good health, are fond of play, are popular with other children and show no peculiarities.
QUAINT old maps, some of them used by generals in planning campaigns, are now turned to a far different use by women who have them cleaned, varnished, and built into lamp shades. Many make attractive pictures when framed. In the photograph a final coat of varnish is being applied. The squared sections represent part of an ancient town; the building at the left is the church.
BY FINGERPRINTS the world’s races can be roughly classified into West European, Italian, Indian, Japanese and Manchurian, recent investigations showed. Prints of persons of the same race were similar. This may help eventually to perfect the specific classification and subdivision of races.
Two minutes and “she’s through”— with a new electrically driven chain saw that has been applied to pile cutting. Such was the time “clocked” for this heavy twenty-inch piling, and but fifty minutes was required to cut a row of twenty-four. Weighing only seventy pounds, this device, which promises great saving in dock work, is easily portable.
FAR up in the air amazing things happen to sound waves. Dr. F. J. W. Whipple, of the Kew Observatory, England, found not long ago that sometimes he could hear a cannon sixty miles away eleven minutes after it had been fired; normally the sound would take less than half this time to cover the distance.
Playing Cards in Tile Form Defy Wind and Hard Usage
A NEW deck of cards in tile form, which borrows the traits of Mah Jong, lets the hostess give her bridge party on the porch without fear of a sudden breeze disturbing the cards. Their solid construction prevents the wear that brings torn corners and cracked backs to paper cards. The “cards” are packed in an attractive box which, as seen below, also provides individual racks for holding the “hands.”
HOW long can a truck run before it wears out? So owners may determine, and thus know the actual cost of trucks in their business, a new clocklike instrument has been invented. Attached to any moving part, it starts to register when motion commences and stops when the machine is idle. Its dial tells just how many hours up to ten thousand, that a truck, or for that matter any machine, has been run, regardless of the speed at which it operates.
A VARIETY of accidents can happen to your automobile that will cause trouble and expense, but there are forms of carelessness for which you may have to pay with your life. Driving with weak or defective brakes is one of them. Failure to inspect the running gear and steering mechanism at regular intervals is another.
New Paint Striping Device Lets Anyone Decorate Auto
A NEW tool makes long practice unnecessary for automobile paint striping jobs. With one of these instruments, illustrated below, any striped design work may be duplicated by an inexperienced painter. The compasslike device has two interchangeable barrels for fine and medium lines attached to one arm and fed by a rubber lacquer-container. The other arm is used for a guide along a molding or rule and stripes are spaced as desired by adjusting the thumb screw.
OFFICIALS of the London Zoo recently obtained the first movies of a Spanish toad swallowing his meal of a worm. A camera taking 1500 pictures a second was required! One taking 500 a second had completely missed the eating act. When the authorities carried off their first film and developed it, they found they had good pictures of the toad, but between two of them the worm simply disappeared and how he went remained as much a mystery as ever.
THESE questions are selected from hundreds sent in by readers. Test your knowledge with them. Correct answers are on page 166. 1. What is the northernmost town in the world? 2. What country is especially famous for its butter? 3. Where is fresh water found 200 miles at sea? 4. Where do men have their wives whipped by law? 5. Where does the abalone live?. 6. What Alaska city is as warm as Philadelphia?
THE question of what to do with old tree stumps has been almost as baffling as the time honored “What shall we do with our old razor blades?” H. W. Ayers, of Burbank, Calif., made an incinerator out of one in his back yard. which was so successful that neighbors were not slow in copying it.
AND now we have the mechanical tutor—a portable professor, to be exact! It is a device that will teach you foreign languages, card games, and the like. If you would learn bridge, for example, all you do is place the arm with the squared indicator over the line of pictures illustrating that game and turn on the power.
WALLBOARD made from cornstalks, a long-standing laboratory achievement, is now about to become a commercial process, thanks to six months’ research by specialists of the U. S. Bureau of Standards. At present the huge corn crop is called the outstanding example of farm waste in the United States—less than twenty percent is used as food.
AN INGENIOUS news-flashing systern has been used of late by Paris newspapers to inform the boulevard crowds of the day’s latest developments. The device resembles the running advertising phrases and time signals flashed in some of our larger American cities, but offers up-to-the-minute news which the operator receives by telephone and spells out on a lettered machine.
FOR years laboratory experimenters have sought in vain to duplicate the secret processes by which living plants form starch and sugar from sunlight, carbon dioxide gas absorbed from the atmosphere, and water taken in through their roots. At last, by an ingenious method. Prof. E. C. C. Baly, of Liverpool University, has succeeded.
THE accepted idea of the heart as an automatic pump sending blood to all parts of the body may have to be revised. A famous German heart specialist, Dr. Mendelsohn, says the heart is simply a governor to control the orderly flow of the blood, this current itself being due to the constant intake and outgo of liquid caused by chemical action in the body cells.
WHAT engineers are doing the world over is made available in a moment by a remarkable new service of the American Society of Mechanical Engineers. Libraries and other subscribers receive each week a batch of index cards to be filed in a special cabinet, bearing titles and abstracts of articles on engineering problems that have just appeared in American and foreign technical papers.
MONORAIL cars will scud at sixty miles an hour beneath the River Tyne on a new type of underground railway seen below, designed by E. W. Kearney, British engineer, if his plan, already passed by the Ministry of Transport, is approved by Parliament. First of its kind, the tube is to connect North and South Shields.
ONE of the strangest farms in the world is the great subterranean acreage of Howard Bell, of Crittenden, N. Y., on which he raises huge crops of mushrooms. Seeking means to cultivate the delicacy, which thrives without daylight, on a wholesale scale, Bell conceived the idea of using an abandoned cement mine.
THE coldest spot on earth is a new laboratory in Berlin, to study strange changes that take place in substances exposed to temperatures as low as 452 degrees below zero—within about eight points of absolute zero! This is done by liquefying helium gas under high pressure,‘then allowing it to expand. At such a temperature some metals, such as silver and copper for example, lose their resistance to electricity, becoming super-conductors.
TELEPHONE line insulators in the Salt Lake Desert, Utah, have a regular wash day to remove salt blown from near-by beds, which cakes on the glass and causes leakage of electricity. Steam is sprayed over the insulators from a nozzle on the end of a fish pole. Though an ageing action on the glass results, B. F. Howard, engineer of the telephone company, says the economy of the method he has developed justifies it.
EVEN the blistering heat of molten metal pouring from a furnace can be measured conveniently and accurately by a new instrument resembling a small telescope. When it is pointed at the glowing stream, the brightness of the reflection seen through the eyepiece is taken to indicate the temperature. Through an adjustable dial this glow is compared with that of a small electric flashlight bulb within the device, and the exact number of degrees directly indicated when the two are matched through a red sighting glass.
IF YOUR son puts away a bigger meal than you yourself can eat, don’t be surprised, advises the Bureau of Home Economics of the U. S. Department of Agriculture. He is merely behaving like any normal, active boy of nine to eighteen. At certain ages boys and girls may need one to one and a half times as much protein and mineral matter as adults, according to a new dietary scale worked out by the Bureau that gives the needs of each member of the family.
THAT the voices of famous present day men, transformed into radio waves, are now wandering around the earth and may be picked up a century hence is the startling contention of engineers of the Marconi Company, London. Such waves, they say, never die out completely; with sensitive enough receivers they might be heard in 2028! Already they have heard programs that have circled the world three times.
What You Can Get From the Several Types of Receivers
A Wireless Electric Light
WHEN is a radio receiver an electric set and when isn't it? Which is better, a battery set or an electric set? What do "socket power,” “electrified,” “full electric,” “direct from the socket” and all the other new radio terms actually mean?
How a 60-Year-Old Residence Became A Modern Home– Hint You Can Use
JOHN R. McMAHON
I AM going to buy that old house on the hill and fix it up in a way you never heard of," said my friend Joe Penka about a year ago. “Put it on wheels and take it to Florida in winter?” I hazarded. “No, although I do have a piece of land down there. My scheme is to make it a combination of a one-family and a two-family house, so that it can be used either way on short notice.”
Beware of the Big Trade-in Allowance and the Service Graft, Says Gus
WHAT'S the matter with your car?" Gus Wilson asked his partner Joe Clark as the latter arrivedone morning on foot. “I could answer a lot easier if you’d ask what isn’t the matter with it,” Joe grumbled as he hung his hat and overcoat on the door of the tiny office in the Model Garage.
HERE is an ingenious way to utilize the regular front And rear seat cushions of your closed car as a bed while auto camping. As you will note from Fig. 1, you will need to construct one long bracket to support the rear end of the rear seat cushion.
WHILE the regular style of jack that you usually carry in the tool kit is, of course, adequate for emergency tire changes on the road, you will find that a simple quick-acting jack such as is shown in Fig. 2 will save a lot of back-breaking work in the home garage.
OPENING the garage doors, driving out and then having to get out of the car to shut the doors after you is a nuisance when you are in a hurry. By constructing garage doors after the fashion shown in Fig. 3 you will be able to back right through the doors, and they will close after you, eliminating the necessity for getting out to close them by hand.
IN LONG trips it is difficult to find room for extra tools. Fig. 4 shows how to solve the problem. If you will take up the floorboards in front of the rear seat you will find that there is plenty of room for at least one deep tool box and one shallow one.
MOST cars sold today are regularly fitted with stop lights, but here is a way to make yours more effective than the standard. Look over Fig. 5. In place of the regular stop light fit a board, and to the top of it attach an ordinary vacuum type windshield wiper.
P. H. ASHBY, of Strathcona, Alberta, Canada, wins the $10 prize this month with his garage door suggestion (Fig. 3). POPULAR SCIENCE MONTHLY awards $10 monthly, in addition to regular space rates, for the best suggestion for motorists. Other contributions published are paid for at usual rates.
Anyone Can Build Successfully This Little Single-Stick Monoplane
How to Assemble the "Flying Stick"
J. D. BUNCH
A. F. KOCH
THERE is a real thrill in flying airplane models. It doesn't matter how old you are or whether you know anything about aviation or not; you can't escape the fascination of the game. But first you have to get into it, and to do that we can think of no better way than to build the model illustrated.
How to Complete the New Popular Science Receiver with an Amplifier and Current Supply Unit Giving Maximum Volume
Blueprint Is Ready!
The Parts to Use
Toy Balloon Improves Blowpipe
IN THE February issue of POPULAR SCIENCE MONTHLY we described the construction of a new electric radio receiver. To complete-this receiver you will need to build either the high power amplifier and current supply unit to be described here or the lower powered and less expensive unit to be described next month.
Hints on Sharpening Chisels, Planes, Gouges,Scrapers, Auger Bits and Saws
CHARLES A. KING
HOME workers and manual training pupils often seem to think that time spent in sharpening tools is largely wasted. They prefer to “put to more strength,” in the words, of the Biblical philosopher who wrote: “If the iron be blunt, and he do not whet the edge, then must he be put to more strength : but wisdom is profitable to direct” (Eccles. 10:10).
How to Lay Out Work Quickly and Accurately on Lathe and Milling Machine—Jigs, Fixtures, Piercing Punches and Dies
HECTOR J. CHAMBERLAND
NEW stunts in laying machine-shop work, although they may appear to save time, are often lacking in either accuracy or practicability. Anyone familiar with this line of work will admit that the method of using movable buttons is hard to beat so far as the average shop is concerned.
A Simple Way to Use Gears for Indexing Work on the Grinder— Depth Gage for Lathe Drilling — Extension Tool Holder for Planer—Universal Joint for Floating Reamer—Other Shop Kinks
Using Gears for Indexing Work on the Grinder
IT IS often necessary to grind indexed work, but as a rule no adequate or universal indexing fixtures are available for grinder work. It is not advisable to use a milling-machine index head on a grinder since it is likely to be injured sooner or later for accurate work on the miller.
WHEN drilling a job chucked in the lathe, such as, for instance, the one shown in Fig. 2, it is possible to rig a gage to indicate how far the drill has penetrated. A strip of sheet metal is secured to the drill chuck with a rubber band, and the end of the strip is lined up with the end of the drill and bent so that it just clears the work.
HOW to overcome the handicap of an old style planer with only a narrow opening between the housings is illustrated in Figs. 8 and 4. A tool holder was made as shown so that the full stroke of the planer does not have to be used. The inside of the tool holder was cut out with a torch to give ample room for bolting it in PLACE.
FIGURE 5 shows how a bench block was fitted with a spring grip arrangement to hold thin metal down at one end while it is being cut off with a chisel. Spring wire was bent as shown, the ends were sprung into a hole passing through the block near the top and suitable coil springs were attached.
IN FIG. 7 is shown an indexing fixture for an engine lathe. A cast-iron or steel disk 10 or 12 in. in diameter is cut as a worm wheel on its periphery, preferably with 360 teeth. This is attached to the lathe spindle in place of the regular faceplate.
How to Lay Out Your Shop for Decorative Metal Work
THE individual craftsman who takes up decorative metal work will, of course, adapt his shop layout to the space available, be it large or small. He may use benches and other equipment already in his possession provided they are in a good light.
How to Interpret the Playwright's Script-Sketches and Models - Hints on Painting and Lighting
IN THE designing and building of an exterior setting the amateur scenewright finds himself up against a more difficult problem than any he has encountered in his experience with intenors. He knows well enough that he can create three walls of a room, but he stands in awe of the wall-less outside, where tree forms, flowers and atmosphere are perhaps the only limits to his set.
They Save Time and Money in Making Essential Repairs—My First Outfit and How I Added to It
WE FARMERS are confronted with a difficult problem in selecting tools for our workshops. In the first place, most of us have not the time to spend in building things purely for pleasure; we build from necessity. In the second place, we are called upon to make many makeshift repairs on our implements and machines until parts come from the factory.
Choosing a Lathe—Spindle Speeds— How to Sharpen Gouges and Chisels
IF YOU have a hobby, you may consider yourself fortunate in this age of speed and mental strain. An interesting hobby takes the mind off business problems, gives it a rest and tends to keep it healthy and normal. Modern psychologists, medical practitioners and educators stress the value and importance of developing a hobby; indeed, it is one of the frankly avowed aims of manual arts instruction in the schools of today.
How to Fill Cracks Around Bathroom and Kitchen Fixtures and in Plaster Walls
F. N. VANDERWALKER
EVEN the most carefully constructed house will suffer a little from the settlement of the foundation. Some cracks will open in the walls and the joints in floors, wood trim and built-in plumbing and cabinet fixtures. Furthermore, the shrinkage of lumber opens up cracks in wood trim and in floors, such as those often seen about a fireplace and hearth of tile or brick.
RECESS tubs, which are butted close to tile and plaster walls, sometimes pull away from the tile, leaving an unsightly crack. The settlement of the floor and the shrinkage of timbers in the wall are the usual causes. To fill such cracks, the first step is to cut off all loose cement and sharp projections with a putty knife or screw driver.
THE defects found in plaster walls are settlement cracks at corners and elsewhere, fine cracks, door-knob bruises, abrasions made by furniture, toys and other objects, and nail and screw holes. Very fine cracks are not large enough to be filled with putty, yet when painted they absorb the liquid and show up as flat streaks much wider than the cracks themselves.
WHEN a wall or ceiling is completely covered with a network of fine “fire” cracks too small to be filled, it is too much work to shellac and flat-paint them. Other means are quicker and better. One of them is to apply a size coat consisting of one half first-class floor varnish and one half turpentine.
SURFACES to be painted, whether wood, metal or composition, must be dry and clean. Any knots and sappy spots in woodwork must be covered with shellac. Cracks and depressions are first painted with linseed oil and then are smoothed over with putty.
A SMALL ornamental plant stand of the type illustrated can be made easily by the amateur woodworker. While stands of this type can be any size, one 14 in. high, 9– in. across the top, and 8 in. across the base will be described. The wood is all ⅞ in. thick.
THE music of the xylophone in either solo or ensemble playing has a piquant quality that makes the time spent in learning to play it well worth while. First it is necessary to obtain an instrument on which to practice, but that is not difficult.
IN SETTING foundation corners for small buildings and in grading, ditching and the like, I have found useful a simple tripod made as shown. It supports a carpenter’s level equipped with sights of the type that can be obtained in the larger hardware stores.
BY FLUSHING out the water-heating coil in the fire pot of your house heating furnace or boiler and by keeping a duplicate coil always on hand so that it can be speedily installed in an emergency, you can forestall trouble with this part of your plumbing system.
A FEW odd bits of material, a few minutes of time, and a little patience are all that you need to make the little elephant shown as this month’s “comicull.” A novelty for use as a dinner favor or toy First take a large walnut shell and a thin piece of wood that is a little larger than the walnut so that it may be marked and shaped to go between the two halves of the shell.
ALMOST daily in my carpentry work I use a method for dividing large spaces into equal parts that is simple, speedy and foolproof. It is so rapid that I can say what the divisions will measure as quickly as I could measure the length that is to be divided up.
Figures, not speculation, are the basis for recent statements that progress of the war against disease is more hopeful than ever before. John K. Gore, Vice President and Actuary of the Prudential Insurance Company, finds that in the last quarter century science has saved 635,000 lives each year, and has prolonged life in thirty-two countries.
ETHER masks scented with perfume are the latest surgical novelty, according to Dr. Gohrbrandt, German physician. The nauseating smell of the anesthetic is said to be eliminated, and the patients go quietly to sleep in comfort. Women, particularly blondes, are as a rule much better at receiving anesthesia than men, declares an American dental expert.