A Six Reel Movie on the Rise of the INVESTMENT TRUST
To Help You Get Ahead
A billion dollars is a lot of money. Within less than a decade, more than a billion dollars belonging to American investors have been put into investment trusts. Today several hundred investment trust companies are operating in the United States.
Tests in the Institute Laboratory Show That Inferior Amplifier and Rectifier Tubes Break Down Under the High Power of the Modern Electric Receiving Sets
F. G. PRYOR
SEVERAL days ago a radio vacuum tube was placed in a test circuit in the radio laboratory of the Popular Science Institute of Standards. There is, of course, nothing unusual about that, because a number of tubes are tested every day in the Institute laboratory, But the action of this particular tube shows what may happen if you are careless about the make of tubes you use in your radio receiver.
“I AM not knocking locomotive engineers, but after reading Arthur Grahame’s story, ‘At the Throttle of the “Big Hog,”’ I am wondering if you realize the importance of a trade which is changing passenger transportation from railroads to motor roads, or the ‘slab.’
WHO, young or old, does not respond to the thrill of fireworks, and of the skyrocket most of all? Exciting adventures of Prof. R. H. Goddard, and of his nine-foot rocket that scared Worcester, Mass., into thinking a falling meteor had exploded, are a part of a project that captures the imagination.
COME OUT AND GET ACQUAINTED THIS SHIP IS MADE OF WOOD AND WIRED TOGETHER THE WINGS ARE NOT COVERED WITH TIN IT DON’T BACK UP
LINDBERGH and I started barnstorming by accident. It was this way. We were both living in St. Louis in 1924. He had sold an old war-time “Jenny” to a boy living up at Oelwein, Iowa. The kid gave him a deposit of twenty-five dollars, or something like that, and flew off home.
Where the World’s Fastest Ocean Liner Gets Its Speed
UNUSUAL features in the design of the German steamship Bremen, new speed queen of the Atlantic, are depicted on these pages. They show why she was able to race into New York harbor, the other day, with a record-smashing mark of four days, seventeen hours, forty-two minutes from the French port of Cherbourg, and then, on her return trip, to lower the record between New York and Plymouth, England, to four days, fourteen hours, and thirty minutes.
Goddard Tests New Missile to Explore the Upper Air for Science
ALDEN P. ARMAGNAC
A SMALL group of experimenters carried a heavy cylinder of steel to the outskirts of Worcester, Mass., the other day. They set it on end at the base of a steel tower forty feet high at the center of a vacant field. Its shape revealed it to be a rocket—but such a rocket as a small boy might dream of the night before the Fourth of July.
New Toy-Sized Auto with 60-Mile Speed May Be Sold by Mail
A TWO-PASSENGER automobile, only five feet between wheels, and so light that a man of average strength can lift the wheels from the ground, is the latest arrival in motordom. At this writing three of the motor dwarfs have been built, and the car is expected to appear on the market within six months.
From a Cranky, Motorized Balloon to Gigantic Ocean Airliners—The Story of Count Zeppelin and His Long Struggle to Perfect the Dirigible
WALTER E. BURTON
TWO airships of size greater than any ever built are soon to go under construction at Akron, O., for the United States Navy. Two other American ships of the same 6,500,000 cubic feet gas capacity, are being designed for commercial service over the Pacific between California and Hawaii, while a project is reported under way for a regular transatlantic dirigible service.
NOT since the death of Luther Burbank, the great plant wizard, has there been a discovery of such apparently revolutionary importance to the farmer and back-yard gardener as that which Mr. Dunn describes here. Fields of grain and vegetables flourishing on the desert; summer flowers blooming at Christmas; five-inch pansies and double-sized potatoes—these are a few of the marvels of a new scientific agriculture which replaces arid soil with shallow tanks of water fertilized by the introduction of life-giving chemicals.
Light Exerts Pressure, Experiments Indicate
H. H. DUNN
EM AN CIPATION of farmers and growers of fruits and flowers from the vagaries of soil, season, and climate is promised by a discovery, of revolutionary importance in crop production, announced by the department of plant physiology of the University of California.
ASTRANGE “insect zoo” was established recently in England. The government experts in charge of it spend their time caring for armies of little six-legged soldiers—insects that prey upon other insects destructive to growing crops. These fighters are being shipped to different parts of the Empire to aid the farmers.
The World Pays Tribute to Thomas A. Edison on the Golden Anniversary of the Incandescent Lamp, Which He First Made to Glow with a Bit of Thread
GOVERNMENTS and institutions throughout the world on October 21 will pay tribute to Thomas Alva Edison, the world’s greatest inventor. That day marks the fiftieth anniversary of his invention of one of man’s most important contributions to man—the practical incandescent electric lamp.
THE picture at the right no doubt expresses better than any words the feelings of millions of Americans as the world celebrates the Golden Jubilee of electric light. What man would not like to shake the hand of Thomas A. Edison and to thank him in person for the scores of modern comforts and conveniences his inventions have made available everywhere?
The Head of a Nation-Wide Broadcasting Chain Tells How He Delivers Entertainment and News to a Vast Audience of Fifty Million People
FRANK PARKER STOCKBRIDGE
IN LESS than three years radio broadcasting has grown from a kind of hit-or-miss novelty show to almost a domestic necessity; from a scattering of small, independent, and often irresponsible enterprises to the newest of the nation’s “big businesses.” The days of “fishing around” to pick something out of the air besides amateur night programs have swiftly vanished.
TWO chemists of the United States Department of Agriculture were testing recently some recipes for chocolate cake. A few of the cakes came out a deep, rich brown, like old-fashioned chocolate jumbles. Others turned out a dull, brownish gray.
BENEATH giant “flying the yacht” 157-foot just wingspread completed of by the Dr. biggest Claude airplane Dornier ever in built—the Germany —could be hidden a pair of Uncle Sam’s greatest bombers. Construction of the new German monster, pictured on this page, required more than two years, and was one of the greatest engineering feats in aviation history.
THE Pennsylvania, largest commercial vessel ever built at an American shipyard, was launched recently at Newport News, Va. This 34,000-ton turbo-electric liner of the PanamaPacific Line will make fortnightly runs between New York and California by way of the Panama Canal.
First Scientific Census Will Put America Under the Microscope
ALFRED P. RECK
WITH the taking, next year, of the fifteenth decennial census of the population of the United States the Government will tackle the greatest piece of scientific research work along statistical lines ever undertaken. Since the first census was collected in 1790, the gathering of information every ten years has been concerned mainly with the number of citizens, their national, racial and religious antecedents, and their occupations.
Shattering the World's Duration Mark—Improved Weapons for Aerial Warfare—Planning a High-Flying Ocean Plane—Marvels of Night Photography—Latest Feats of Motorless Flight
Anchorage for Seadrome
To Berlin in Six Hours?
A Camera “Machine Gun99
Wind Vane for Night Flyers
Sharpshooting with Bombs
Parachutes Tested by Monkeys
Aerial Photos by Night
Women Aces Recognized
Two New Glider Records
THE once imaginary spectacle of a man getting into an airplane, saying to those on the field, “I’ll be down two weeks from next Tuesday,” and soaring aloft is today a reality. Of late, one endurance record after another has been shattered, culminating, at this writing, in a mark of seventeen and one-half days in the air.
A HURRICANE that could knock a man flat will soon rush through a tube ten feet in diameter, which, when completed soon at Pasadena, Calif., will form one of the finest aeronautical • wind tunnels in the world. Within it a set of vanes that looks vaguely like a giant automobile radiator will control a man-made gale of 120 miles an hour, produced by a four-bladed propeller with a streamlined electric motor.
"AND a package of haddock,” a Kansas housewife tells her grocer. He hands her a sealed box, faintly cool to the touch. In the kitchen, she drops its contents in a frying pan. It is a fish fresh from Atlantic waters, now for the first time available to her through a new process of quick freezing.
OVERLOOKING the Golden Gate, at San Francisco, California, is an unusual astronomical observatory, owned and operated by a high school. The building and its equipment are mounted on the top of the annex of the Galileo High School, which is named after the famous Italian astronomer of the seventeenth century.
ACONCRETE dam that will be a foot higher than the present record holder, the Pacoima Canyon structure of southern California, described in a recent issue of POPULAR SCIENCE MONTHLY, is being built on the Skagit River in the state of Washington.
PROPELLERS of two outboard motors lashed to the sides of the after deck of the Margaret FIV, a racing sloop, recently drove it through the Erie Canal. When the owner decided to take the craft from New York City to Detroit, he found the hull was too high for convenient transportation by rail and decided to take it through the canal.
BY MAINTAINING a temperature of 458.58 degrees F. below zero in a chamber twelve cubic inches in size— nearly that of a half-pint container— Prof. W. H. Keesom, Leyden University physicist, recently paved the way for experiments to reveal new properties of matter.
THE fight against the invisible typhoid bacillus was marked with increased success last year, the American Medical Association reports. Of eighty-one cities in the United States having populations over 100,000, nine had no typhoid deaths during 1928.
A SUNDIAL almost as high as a house, and said to be the largest in the world, was completed recently in a residential district of San Francisco, Calif. Its sloping stile, which casts a shadow to indicate the time of day, is made of reinforced concrete; and about it circles a curb of concrete to form the dial itself, which is marked with hourly divisions.
HIGH tension lines, carrying thousands of kilowatts of electrical energy at high voltage, now can be economically tapped to supply current for farms and scattered villages along the line. The expense of installing elaborate substations has been eliminated by a miniature substation recently developed in the laboratories of the General Electric Company.
EXPRESS trains which literally “fall apart” at full speed to deliver cars and their passengers at small way stations were put into service in England the other day. Coaches destined for minor stops are attached to the rear and detached or “slipped” when their stations are reached, while the train speeds on.
HOW many ants are there in the average mound? About ten thousand, according to Prof. E. A. Andrews, of Johns Hopkins University, Baltimore, Md. In one case, Professor Andrews actually counted the ants in a mound and found its galleries inhabited by exactly 8,239 individuals.
THE Bremen, famous Junkers monoplane, which made the first westward crossing of the North Atlantic last year, recently arrived in New York City, where it will be kept on permanent exhibition at the Museum of Peaceful Arts. The machine was presented to the city by the late Baron von Huenefeld, who with Hermann Koehl, German pilot, and James C. Fitzmaurice, Irish airman, made the historic crossing.
OPENING the windows and letting Nature take its course is still the most effective way of airing a room, and no mechanical ventilating system thus far devised improves on this old-fashioned method. Such is the conclusion just reached by the U. S. Public Health Service after a survey of schools to determine the frequency of colds, bronchial trouble, and other respiratory diseases among the pupils in relation to the means of ventilation used in the buildings.
A CIGAR lighter that can be installed on an automobile dashboard in a moment and requires no wires or batteries has appeared on the market. A rubber suction grip holds it to the dashboard. When its cap is pulled off, as pictured above, a file rasps upon flint, igniting the lighter, which is designed to burn any fluid used in the ordinary pocket device.
WOLVES roaming the tundra of Alaska are killing off reindeer at the rate of about 100 for each wolf during a winter. More than 500 reindeer were killed by only five wolves last winter near Unalakleet, and the previous season 200 were slain by two wolves near St. Michael.
TEN shots a second is the reported maximum speed of a new machine gun invented by a Russian and recently introduced in the Soviet army and air forces. Allowing for the time it takes to change the drums, the gun discharges 150 bullets a minute. The Lewis machine gun, used previously by the Russians, fires 125 shots a minute.
A FEW years ago, a pedestrian was crossing a street at a busy corner in Cleveland, O. Just as he was halfway across, traffic lights changed and he escaped the unleashed automobiles only by a mad dash for the curb. As he walked on, an idea popped into his head.
ULTRA-VIOLET rays, used in the treatment of rickets and other ailments, now are being called to the aid of the historian and antiquarian. Recently Professor G. R. Köbel, of the University of Vienna, Austria, discovered that, by means of ultra-violet rays, the now invisible writings on palimpsests, the doubly-written parchments of Medieval times, may be photographed and deciphered.
A WATCH that is said to have kept perfect time for a hundred years has provided its owner, Miss R. Belville, of London, England, with a steady income for forty years. Known as “The Clockwoman of London,” she makes daily trips to a number of business houses, setting their clocks to the correct Greenwich time as told by the old timepiece, known as “Arnold 345.”
TIGHT-ROPE-RIDING automobile recently thrilled watchers in the vicinity of Berlin, Germany, when H. Kambrinow, a dare-devil rider, drove the machine along parallel high tension wires for almost a fifth of a mile. At some places the swaying wires were a hundred feet from the ground, with yawning limestone quarries below, yet the heavy machine completed the trip safely at fifteen miles an hour.
A RED, green, or white light is possible with a new electric flashlamp pictured above. It is designed especially for policemen, motorists, and campers, for whom it serves as a handy method of night signaling. When both buttons on the front of the device are at the bottom, the light is white.
PLANTS and birds descended from species that lived millions of years ago still exist, while the large mammals and reptiles of prehistoric times, such as mastodons, dinosaurs, and giant armadillos, have been extinct for centuries. This fact was revealed by recent excavations in two widely separated parts of the world.
INVENTION of a rubber tire that cannot be punctured, though it contains no metal armor, is claimed by E. C. Walton, LaPorte, Ind., engineer. His tire is protected by studding the tread of ordinary rubber with hard rubber disks, arranged in several layers beneath the surface so that they cannot work loose.
EFFICIENCY and mass production, watchwords of modern industry, have invaded the henhouse. Department of Agriculture statistics show that the United States had fewer hens last year than in 1927 but that the birds more than made up for the thinning of their ranks by laying a greater total of eggs.
IMAGINE a blow torch, used to cut through steel girders, playing for an instant on a piece of paper without singeing it, or a piece of wood resting momentarily unharmed in a white-hot blast furnace. Those apparent reversals of nature’s laws are said to have been accomplished by two experimenters in Los Angeles, Calif.
TWO recent innovations in building provide convenient nailing blocks for attaching baseboards, picture molds, or wall panels to walls made of hollow tile or terra cotta, or containing metal lath. For the metal lath, square steel clips, each with an opening on one side that allows it to be slipped on one of the narrow metal uprights, provide anchors for wooden wedges driven into the clips to form nailing blocks.
IN A recent report to the American Medical Association, two physicians of St. Louis, Mo., described a disease which resembles hay fever in its causes. They told of persons suffering from purple spots on the face or body after eating small quantities of eggs or beans, or drinking as little as one spoonful of as one spoonful milk.
WATCHES soon may be set automatically by radio if plans of an American timepiece manufacturer are successful. There is a race between this firm and a German concern, to produce the first radio-regulated timepiece that is practicable, according to Louis G. Caldwell, former general counsel of the U. S. Radio Commission.
PART of the ozone, that mysterious and healthful form of oxygen in the earth’s atmosphere, may be produced by sunspots. Dr. F. E. Fowle, of the Smithsonian Institution, Washington, D. C., recently advanced the theory that, while one layer of ozone in the atmosphere is created by the ultraviolet light of the sun, another owes its origin to minute particles emanating from sunspots and shot at the earth by billions.
COMBINING beauty with utility, a California architect recently designed a new type of fire escape which constitutes not only an effective means of rescue but also an escape from the ugliness of the conventional gratings and ladders. In his plans for the headquarters of a Hollywood motion picture concern, he substituted for the usual iron framework a series of decorative concrete balconies, connected between floor levels by a system of steel stairways.
TIME is saved in setting nails, or driving their heads below the surface of wood in finishing work, by a new tool designed to eliminate the usual hand-held punch. A conical opening at the bottom of the tool, pictured above, automatically centers the nail head below a plunger which is struck with a hammer to set the nail.
WITHIN a few years every large city in the United States will have a “cancer institution,” equipped with from $500,000 to $1,000,000 worth of radium treatment apparatus and manned by .a staff of experts and surgeons. Such was the recent prediction of Dr. James Ewing, head of the Department of Pathology in Cornell University, Ithaca, N. Y., and a noted cancer specialist.
IN TWO generations of a Brazilian family reported to the Eugenics Research Association, five of the members have been born without hands or feet. Three are children. Their father, similarly crippled, died recently. One uncle, also deformed, still lives. In explaining the strange case of hereditary deformity, biologists say the tiny living granules, called chromosomes, contained in every living cell, transmit characteristics from one generation to another.
THAT the skin pigment of the so-called black, yellow, and red races does not differ from that of the white race except in quantity is the conclusion of two scientists at the Mayo Clinic and Foundation, Rochester, Minn. Using a spectrophotometer, or color analyzer, they have made a study of skin coloring in regard to vividness, hue, and amount of light reflected. They found that some men are black and others white not because of different-colored pigment, but because varying amounts of the same pigments reflect light in different degrees.
THE fact that a man prefers blondes to brunettes may indicate that he should be an engineer instead of a lawyer, farmer, clerk, or mechanic, according to Prof. H. H. Remmers, of Purdue University. In a recent questionnaire submitted to agriculture and engineering students, he discovered that the engineers like short women, blondes, shopwork, city life, and methodical people.
AS A jagged streak of lightning twisted ACROSS the sky over the office buildings of downtown Chicago during a recent thunderstorm, a photographer on Michigan Avenue obtained the remarkable photograph at the right, catching the brilliant streak of millions of horsepower of electrical energy as it appeared framed by skyscrapers.
LINDESAY PARROTT, a New York newspaperman, claims to be the first reporter to phone a story to his editor from under water. Recently he sent in a feature story while standing on the bottom of the East River, between Manhattan and Brooklyn. Attired in a diving suit and helmet, he was lowered over the side of a tugboat and began his descent.
ALTHOUGH $100,000,000 is spent in THE United States each year for cosmetics—more than ten times the sum this country sets aside annually for scientific research—American women are by no means the inventors of this form of facial adornment, nor are their presentday European sisters.
A PEACEFUL invasion of England on water bicycles took place recently when a French sportsman and a twenty-two-year-old girl pedaled their way safely across the twenty-odd miles of rough sea water separating Calais, France, from Dover. The first trip was made by Roger Vincent, who “bicycled” his way across the English Channel in slightly more than five hours, in spite of high seas and strong contrary winds.
RACING over winding rails in the shadow of snow-covered peaks, the Empire Builder, the Great Northern Railway’s latest crack train on the ChicagoSeattle run, recently inaugurated a new sixty-onehour schedule between the two cities.
LEPROSY, regarded for centuries as an incurable disease, has in the past few years been treated successfully with chaulmoogra oil, obtained from an East Indian tree. This method, however, has two disadvantages—the treatment takes several months and the oil is so nauseating that it cannot be administered in very large doses.
IF A person is quick-tempered or timid, or both, he is more to be pitied than scorned, for he probably is still a victim of diseases suffered when a child, according to Dr. George M. Stratton, of the University of California. Experiments with students conducted by Dr. Stratton indicated that those who had suffered the most diseases in childhood were most susceptible to anger and fear.
AN AUTOMATIC detector to locate gas leaks or warn of the presence of firedamp in mines has been invented by a woman in Paris, France. Whenever the quantity of gas in the atmosphere is greater than 1.3 percent the instrument sounds a warning by ringing a bell and flashing a tiny electric lamp.
IN WINTER, the air in the average American home has less humidity than that over the Sahara desert. A kiln for drying lumber contains more moisture than a typical American room. These surprising facts were discovered during a recent study, in New York state, of the effect of dryness upon valuable rugs.
A BROADWAY actor who had entered the “talkies” told in POPULAR SCIENCE MONTHLY, a few months ago, how the tearing of a piece of paper during the filming of one talking picture had spoiled a sound sequence that cost approximately five hundred dollars.
IN MOST cases, neither sorrow nor joy but rather relief from the tension induced by either one of these emotions is the real cause of tears. Dr. Frederick H. Lund, of Bucknell University, and Dr. H. V. Pike, of Danville State Hospital of Pennsylvania, after an investigation of the causes of weeping, recently reported this conclusion to the American Psychological Association.
THAT “boys are harder to rear than girls” was recently given support by statistics issued from the Children’s Bureau of the U. S. Department of Labor, in Washington, D. C. These reveal that, although more boys are born in the United States than girls, the latter have thirty percent more chance of living.
WHEN five brothers of Madison, N. H., constructed their own airplane, they included features not found in more conventional models. Following the design of Z. D. Granville, twenty-eight, oldest of the quintet, they put the joy-stick on the dashboard instead of in the floor, to give the pilot more room, and made the top wing adjustable for high or low speed flying. The photo shows the plane’s designer in the cockpit, and the four other builders standing by.
A FEW months ago, P. A. Best, director of one of London’s large stores, told in POPULAR SCIENCE MONTHLY of the need of a new style of handwriting that would enable clerks to write fast and foolproof records. Illegible sales slips, he estimated, cost department stores millions of dollars a year.
A MECHANICAL baby-bottle holder, designed to relieve mothers of the strain of holding the bottle while infants finish their meals, was recently exhibited in Chicago. Attached to a weighted base is a flexible arm similar to those used on desk lamps.
THOUGH composed of only one cell and not much larger than a pin-point, the arcella, a tiny creature that inhabits the ponds and streams of Europe, carries its own life-saving equipment within its microscopic body. The late Dr. E. J. Bles of Cambridge University, England, discovered not long ago that the minute animal, which lives in a miniature shell, possesses a chemical mechanism by which it saves itself from drowning.
A THIN coating of aluminum over duralumin, the light metal used extensively in dirigible and airplane construction, was shown in tests made by the U. S. Bureau of Standards to prevent corrosion which makes the high-strength alloy brittle and weak.
BY INJECTING paraffin into the chest, Dr. Hugo Hauke, a surgeon of Breslau, Germany, has speeded the recovery of tuberculosis patients, he reported recently to a surgical congress in Berlin. During pulmonary tuberculosis, cavities form, particularly in the upper lobes of the lungs, and prevent the curative process, Dr. Hauke explains.
"WAFFLE pavement" is the latest protection against skidding in Berlin. When an asphalt street was laid recently in the German capital, a huge “centipede” machine with several rollers, in a train, ran over the hot surface to give the final leveling.
A SUDDEN increase of flat feet among women has been noted by a German orthopedist, Dr. Gustav Muskat. In the past, he says, approximately twice as many men as women have had flat feet, but recently the ratio has changed, so that now it is three to five against the women.
TEST your knowledge with these questions, chosen from hundreds asked by our readers. You will find the correct answers on page 156. 1. Why is the picture on a film reversed—black where white should be? 2. What is the difference between a fast lens and a slow one?
PHYSICAL comfort should be the guide in the matter of house ventilation according to experts of the U. S. Public Health Service. The idea that all out-door air is “fresh” is a fallacy, they say, and so is the notion that sleeping with wide-open windows, regardless of temperature and weather, is necessarily healthful.
AUTOMOBILES are “stacked” five deep in a novel experimental parking tower recently opened at Sandusky, O. Occupying ground space no greater than that required for an ordinary two-car garage, the tower accommodates ten machines. The inventor is J. E. Morton, a Sandusky engineer.
ANOTHER “round-the-world” trip is being taken—this time by a species of herring, the American shad. From Oregon rivers young shad are being transplanted to Japan, with such success that the Japanese government plans to spend large sums to further the work.
THE municipal health department of Bordeaux, France, proposes to ask all citizens to carry cards which will contain a record of every disease the bearer has suffered, every operation he has undergone, and other notations concerning his health.
MORE than 7,000 false fire alarms were turned in last year in New York City alone. Nearly one out of every four times that the fire engines dashed through the streets, they were wasting time and money responding to a false alarm. To protect the city from the costly pranks of practical jokers, a new fire alarm box, equipped with a mechanical “eye,” has been designed to photograph each person who turns the alarm key.
MORE than 100,000 eggs are collected every day at one of the world’s largest poultry farms, near Los Angeles, Calif. On this hundred-acre ranch are housed 300,000 laying hens—equal to the total population of a city the size of Denver, Colo. Add to this number the 200,000 baby chicks which are being raised to become egg producers, and the total becomes half a million.
GRASSHOPPERS, which, like ail other insects, have no lungs, breathe through an intricate system of air tubes ending in tiny valves in their sides. The insects are able to control the operations of these pipes and portholes at will. These facts were revealed in experiments conducted the other day by James M. McArthur, a Louisiana entomologist.
THE hope of producing superior types of men by X-rays is pronounced futile by Dr. Halsey J. Bagg, of Memorial Hospital, New York City, an expert on heredity. Success in producing variations in fruit flies and mice by exposing the parents to the rays have led some experimenters to conclude that human evolution might be speeded.
The New Methods of Radio Reception Are Explained Here in Simple Terms—Why They Stop Distortion and Give Better Tone Quality
ALFRED P. LANE
MUCH the “power will be said detector” this year tube about as an important feature of a modern radio receiver. And many persons will get the impression that a “power detector” is some sort of a super detector circuit, far more sensitive than the ordinary hookup.
Three Handy Tools for Set Builders—New Standards for Measuring Sensitiveness—Simple Ways to Test Voltage
Testing High Voltages
A B C’s of Radio
IN WORKING on a radio receiver, exasperating jobs that are almost impossible to get at with bare fingers become easy if the fingers are supplemented with proper tools. The illustration on this page shows three of the most useful tools in radio.
A Few Simple Precautions Save Radio Apparatus from Short Circuits and Fires
ELECTRIC and tireless current worker is when an obedient properly controlled, but if a breakdown permits it to flow outside its normal path valuable apparatus may be ruined in the twinkling of an eye. A radio receiver may operate smoothly and without trouble for months or even years and then, without warning, insulation may give way and a short circuit may turn valuable apparatus into smoking scrap metal, perhaps setting fire to the whole set.
WHY does the paint on one house go to pieces in a few months, while on another it lasts for years? In this article an expert gives the answer. For free advice on your painting problems, write to the Building Service, Popular Science Institute, 381 Fourth Avenue, New York City.
ROGER B. WHITMAN
TO BOB KERSEY, paint was merely for decoration, or to freshen things when they were shabby. That there was more to it first occurred to him when he found his friend, Tom Sands, all worked up because something was the matter with the paint on his garage.
NOT left long the employ ago, W. of B. the Coleman state of Virginia after serving since 1919 as official breeder of quail. In those ten years, Coleman raised more than 20,000 bob whites on the first and largest farm in the world devoted to the breeding of those shy, wild game birds in captivity.
How to Cut Designs for Decorating Furniture in a Material Much Easier to Work Than Wood
MOST chisels men and who gouges own a have selection ised themselves that they do some wood carving “sometime,” but the closer they get to the the bigger it looks. Linoleum carving—a new and fascinating craft—offers an cellent solution. Linoleum is much cheaper than it can be had in pieces of almost any it is easily and quickly worked, it does warp, and, if a piece is spoiled, the loss not very serious in either time or money.
Unusual Noises Are Symptoms of Trouble, Says Gus, But Don’t Let Your Ears Spoil the Fun of Driving
Ask Gus—He Knows
"THERE! Hear that? There it is again!” Bancroft exclaimed, as he singed the tip of his ear on the hot exhaust manifold in the attempt to listen more closely. “I tell you there’s something wrong with that motor.” Gus Wilson listened intently for a few moments.
YOU have probably noticed the sensation caused at social gatherings by someone, perhaps disguised as a gypsy, who was able to “tell fortunes.” Here is a trick which will go the professed amateur palmist one better and with which you can excite double the amount of curiosity.
Protecting the Face When Under Car—An Emergency Flange Repair—Other Useful Ideas
PROTECTION and face from dirt of and the grease eyes while working beneath an automobile is afforded by the ingenious homemade mask shown in Figure 1. Take a piece of celluloid, such as is used for the windows in the curtains of open cars, and with a couple of pieces of string tie it in semicircular form about the face.
FIGURE 2 shows an emergency method of repairing a broken carburetor flange which may prove serviceable on a trip. It will do the trick until a service station or garage can be reached, and the broken flange replaced with a new one.
IN MANY types of cars grease has a tendency to work out, to some extent, around the bottom of the gearshift lever. The shoes of a driver are likely to come in contact with this grease and be stained. To eliminate the trouble, cut a short section from an old inner tube and slip it over the gearshift lever to the bottom, as in Figure 3.
AFTER the cylinder head has been scraped free from carbon, it is desirable to remove the carbon from the lower threads in each spark plug hole. A simple way to do this is to grind or file grooves across the threads of an old spark plug, as shown in Figure 4. Remove the gasket and screw the filed plug into the hole. It will seat slightly deeper than the standard plug and will remove carbon from the thread groove. A still better method, if a lathe is available, is to turn down the body of the spark plug, just above the threaded portion, to a diameter slightly smaller than the bottom of the groove.
FIGURE 5 shows a novel and very simple door check that will prevent the door of a garage from blowing closed. A block of wood is screwed to the door and another flat piece of board is hinged to it by means of an ordinary strap hinge. A spring is hooked between two nails, one in the fixed portion and one in the movable portion.
FRONT tires on cars fitted with four-wheel brakes may wear more rapidly than the rear tires if the front brakes are set too tight. This trouble can be eliminated by making sure that the front brakes do no more than their fair share of the work of stopping the car.
IN woodworking LEARNING machinery to use small or a motorized home workshop, you will find this Maryland end table a particularly instructive and desirable piece of furniture to build. Because of its delicate proportions and graceful lines, it is a little gem; at the same time it is simple in and the materials are inexpensive.
IN MODERN homes a kitchen cupboard extending from floor to ceiling often is built along one entire wall. If you live in a house without this convenience, you can construct a suitable cabinet yourself without much difficulty or great expense.
Setting Up Small Parts—Plates for Obtaining Variations Up to Twenty Degrees—Emergency Jobs
VERY small angles can be produced conveniently by a machinist or toolmaker with the aid of the adjustable blocks and plates of Figs. 1 and 2. In these devices, the angle is obtained by spreading the two “wings” by means of set screws, and holding the adjustment by corresponding lock screws.
ALWAYS use the arbor press to drive a piercing punch or bushing into its holder. A cheap way to patch broken teeth in a cast-iron gear is to drive in pins; a good way is to dovetail the job. Consult your neighbor on a difficult job; two heads are better than one.
THE drill extension shown below combines an unusual number of desirable characteristics. Held as rigidly as if it were solid, the drill is yet instantly removable. The holder can be made to be only twenty-five percent larger than the drill diameter, and the combination of the two will still have the full strength of a solid drill.
MANY useful tools for the home workshop can be made from dull or broken hack saw blades. These blades are of fine tool steel and very hard ; it is necessary only to heat them to a dull red and allow them to cool slowly, when the steel will be found soft enough to be filed and bent into various tools, which then may be hardened, tempered, and ground.
IN CONVERTING oil lamps into electric lights, the main problem is find a satisfactory way to support the cluster and stem which elevates the bulbs and holds the new shade. As explained in a preceding article, “Wiring a Vase for Lights,” (July issue, page 112), you can buy a ready-made, completely wired assembly to be screwed into the opening of the lamp.
THERE are many ways to handle kalsomine, simple and inexpensive finish as it is, so as to gain uncommonly decorative effects. It should be remembered, however, that most of these decorative wall finishes can be carried out in a more permanent form by using either prepared fiat wall paints or white lead and flatting oil tinted to suit.
WITH the aid of a large metal embroidery hoop of the kind having a spring to keep it taut, you can make a practical and convenient disk sander for use on a small lathe or an electrical home workshop. After buying the hoop at a ten-cent store or a department store, screw a block of wood about 1 in. thick to a faceplate and turn it to a diameter slightly larger than the inside of the metal ring.
ALTHOUGH model yachting has become a national pastime and much has been published on both the building and the sailing of miniature boats, little attention has been paid to casting keels, with the result that this work is generally turned over to a foundry.
ONE is polishing job in the tarnished home that metal. is no Nickel joke and nickel-plated articles do not tarnish as readily as some of the other metals such as silver and brass, but to keep them in good condition, they should be frequently washed in hot, soapy water.
Built at Relatively Low Cost, It Gives Homemade Furniture a Professional Look
W. CLYDE LAMMEY
NO one DOUBT time or every another home has worker viewed at with certain envy the neatly molded curved edges that are a characteristic of many fine pieces of furniture. Such a molding is comparatively easy to form where it is straight; but when it must be applied to curved edges, it gives a hard challenge to every workshop enthusiast.
CONCRETE can be used in making an inexpensive tamper for cement work and odd jobs about the garden. All that is required is a tin can 5 or 6 in. in diameter, with the top removed. Drive several nails into the end of a suitable hardwood handle so as to form radiating projections.
A STRONG type of joint for light model airplanes, especially those having a framework of delicate bamboo members, can be made as shown at A. The members are butted together and fastened with an ambroid type cement; then reinforcing fillets of a plastic wood composition are added.
THE accompanying designs for an amusing bridge table set were submitted by George Gordon, Jr., of the Congress High School, Bridgeport, Conn., in a contest conducted by the Educational Department of POPULAR SCIENCE MONTHLY for teachers of shopwork. Mr. Gordon won first prize in the advanced metalworking division of the same contest with a design for andirons, which will be published in another issue.
IN MY home workshop I run several bench woodworking machines with one motor, as shown in the accompanying illustrations. The motor is mounted on a wooden sub-base, which slides on the lathe shears or bed and may be clamped solidly at any desired point.
SINCE the upper half of the space in the side compartments of the ordinary sideboard is rarely utilized, it is often desirable to make an extra drawer as shown in Fig. 1 for holding additional linen. The guides, preferably of the same material as the sideboard, are made as shown at A, Fig. 2. The upper guide on each side is placed 6 in. from the top of the compartment.
IF model YOU are airplane building described the flying in scale the article “How to Build a Lockheed Model” published last month, your next step will be to construct the wing. You will need the following materials: 3 pcs. balsa for wing ribs, by 2 by 20 in.; 2 pcs. balsa for entering edge, ⅛ sq. by 20 in.; l pc. balsa for wing beam, ⅛ by ¼ by 31 in.; 2 pcs. balsa for trailing edge, 1/16 by 3/16 by 20 in.; 2 ft. 3/32 in. diameter white German reed for wing tips; 2 pcs. of superfine Japanese tissue 18 by 24 in. for covering the wing; one 2-oz. bottle of light dope.
IN ONE corner of a recently acquired suburban property was a shed that was spoken of as a garage. Its walls were of unpainted rough clapboarding, there was no trim around the windows and doors, and the lean-to tool shed was built of boards that had once formed a real estate sign.
ORDINARY book ends or blocks, no matter how heavy, are likely to spread apart when a number of volumes are placed between them. The book holder illustrated, however, will not slip, because of a locking effect obtained by means of two dovetailed slides.
BOMBS and parachutes can be dropped from a model airplane by means of the simple releasing device illustrated. When the propeller shaft turns, it pulls the thread through the rubber band and allows the bomb or parachute to drop. Several can be dropped in succession, if DESIRED
TO DISCONNECT an electric appliance by grasping the cord near the point where it is connected to the plug will soon loosen the connections. It is better to fasten a loop of strong string, such as chalk line, to the plug on the inside.
IF YOU make two paint-pot hooks of the type illustrated, you can ascend a ladder with two buckets of paint and two or three brushes and still place the hooks without difficulty over a rung wherever you desire. To use the hook, place your fingers, in the ring made for that purpose, drop the paint pot between the rungs, and catch the hook on the rung above.
WHEN given a slight push on a smooth table or floor, the trick spool illustrated will perform unexpected spins and turns, but if rolled hard, it will go in a relatively straight line. To make the toy, a section of curtain pole about 1⅜ in. in diameter and 2¼ in. long and two stiff cardboard disks about 3 in. in diameter are required.
SMALL and medium sized ship models may be simplified by making the hull in two parts. The work is more convenient to handle and the rigging is made taut without tying knots in inaccessible places. In making a 10-in. model of the Constitution, two pieces of wood were selected for the hull, each large enough to take the deck plan of the model.
FOR a home workshop where only one machine is in use at a time, I have found after considerable experimenting with other arrangements that the one illustrated in Fig. 1 is practical and economical. When I want to use any particular machine, I simply put on the belt for it and leave off all the other belts.
WHEN the home experimenter needs a simple device for regulating the tension of light springs or similar purposes, he can make one quickly and cheaply from the adjusting nut and stem of a pair of ordinary school compasses as shown. It can be mounted by means of a Staple or a bent nail.
AMATEUR craftsmen who enjoy lathe work will find these metal candlesticks a satisfactory problem on which to try their skill. A piece of 1¼-in. cold-rolled steel about 5 in. long will make two cups. Face off the ends, bore a ¾-in. hole 1 in. deep into each, and drill the rest of the way through the piece with a 13/64-in. drill. Thread this hole for at least ⅞ in. with a ¼in.-20 U.S.S. tap.
MANY a glass cutter that has been thrown away because the wheel failed to give satisfactory service might have been used many more times if resharpened on a fine oilstone. To sharpen a wheel, hold the cutter as if to cut glass but with the wheel inclined on the oilstone as shown at A and B.
OLD phonographs, which the newer music boxes make a little out of date, can be given a better voice by substituting an exponential or air-column horn for an the old one and by adding an improved reproducer and tone arm. This type of horn can be obtained from almost any large radio supply house.
CONCRETE workers are frequently called upon to bend reinforcing bars and heavy bar iron without heating, often with no adequate facilities. A simple way to bend them is to use two pieces of iron pipe, preferably about 4 ft. long. The bar is passed through the two pipes, one of which is held down with a foot while the other is pulled up and, if desired, bent back to make what is known as a “hairpin” bend.
WHEN the writer was confronted with the problem of making a small worm and gear for light service, he used a method that simplified the work very much. In place of first cutting gashes in the worm-wheel blank, he cut the teeth from the solid, and used a tap for a hob.
PROBABLY the most familiar form of spring hinge is the screen door type shown at A, which is applied simply by holding the door in place with wedges and driving the screws. The flange type B is another form of A; it may be used in places where the door is to be hung between the jambs of an opening.
THE answer to this question must be divided into two parts, with reference to the additional questions: Does a fuse blow out when the cord is connected to the circuit? Does the fuse remain intact, but the appliance fail to function? The blowing of the fuse denotes a short circuit, either in the connections at the end of the cord or perhaps in the lamp or appliance itself.
SMALL brass pulleys sometimes are needed for curtains, for yacht models, and for other uses. To make them, shape a piece of scrap brass as indicated. Drill a hole through one end, fold the piece end to end, and drill a matching hole through the other end.
LIKE their many home of those workshops, who are I motorizing needed a pulley shaft to use with a ¼-H.P. motor. Finding that one would be somewhat expensive. I visited a garage junk pile and obtained parts for constructing an entirely satisfactory shaft, as shown in Figs. 1 and 2.
1. The light sensitive material on the celluloid film consists of a mixture of gelatin and silver bromide. In some way not yet fully understood, the light falling on the silver bromide causes a molecular change in its structure which cannot be detected by ordinary means but the effect of which shows up in the development of the plate.