THE telephone on George Lambert’s desk rang insistently. With a gesture of annoyance, he put aside the blue-print he was studying, and picked up the receiver. “Yes, Lambert speaking . . . oh, hello Steve, how’s the boy? Glad to hear it, feeling pretty good myself.
Present sets approach perfection so closely that those bought now will not be outmoded by any changes that are likely to be made in the next few years.
F. G. PRYOR
A GOOD modern receiver would double and triple the radio enjoyment of many people who are struggling along with an old radio outfit. The new set, in many cases, would not cost as much as the old. But it is not so much money consideration that is keeping these people from replacing their out-of-date sets as one mistaken idea or another—all of which could be quickly exploded were they given the chance to talk to a radio expert.
WHEN I read the letter from Goshen, Ind., in a recent issue of POPULAR SCIENCE MONTHLY, I sure started to boil. The very idea of anyone saying such a thing about POPULAR SCIENCE MONTHLY is enough to make me bite a ten-penny nail in two. When O. O. wrote that letter he must have been under some malign influence.
First of a Series of Articles That Explain "Life—The World's Greatest Mystery" Just the Things You Always Wanted to Know
MR. MOK: Dr. Gregory, can you tell me where man came from and how long he has been on earth? DR. GREGORY: That is a large question and one that has stirred up a thousand bitter fights. In the old days, they thought they knew the exact answer. For example, in 1641, a great English scholar, Dr. John Lightfoot, vice-chancellor of Cambridge University, announced that man was created on October 23, 4004 B.C., at nine o’clock in the morning.
WILL America be destroyed from the air? Will winged messengers of death ride over the country raining poison gas on men, women and children? Will they drop a hail of bombs to demolish the sky-scrapers of New York or swoop down, for a lightning attack, on the Capitol at Washington?
HILLCREST FARM, Gates Mills, Ohio. To the compiler of statistics, that may mean just one of 6,371,640 farms listed in the United States. But, to birds, it is an address to remember. It is the home of the Baldwin Bird Research Laboratory, unique among American institutions.
Air Battles Given New Fury When Dutch Boy Hooks Machine Gun to Propeller—Rivals Plan His Ruin
ROBERT E. MARTIN
ONE Tuesday evening in 1915, an excited young man leaped aboard a train pulling out of the Berlin station for northern Germany. He was Anthony Fokker, Dutch designer of fighting planes. Under his arm was a precious bundle destined to revolutionize battles in the sky.
ON A six-by-eight-foot screen in a darkened room appeared a spherical object. It resembled a gray indoor baseball, crisscrossed in all directions by fine threads of silk. Slowly and aimlessly it rotated. “The spore of the bacterium that causes lockjaw,” came a voice from the loudspeaker of the motion picture apparatus.
IT WAS a little after six o’clock on a March evening. The world’s largest grain elevator, a sprawling ten-million-bushel monster of steel and concrete, lay silent on the outskirts of Chicago. Only a night crew of six remained on duty. Suddenly there was a terrific blast.
AUTO EQUIPPED WITH BALLOONS TO FLOAT IT WHEN CROSSING RIVERS
A NOVEL and original auto was tried out in the Severn River in England recently. The car was designed to make an exhibition tour from London, England, to Capetown, South Africa. As an aid in crossing rivers on the long trail, it has been fitted with “balloons” that will keep it afloat.
IF PLANS of the United States Weather Bureau work out satisfactorily they soon may have a “weather man” flying regularly over Cleveland, Ohio. Manufacturers have been asked to bid for furnishing planes for daily flights to altitudes of five miles on weather recording trips, carrying instruments.
As IF they were pointing a searchlight, radio engineers on the cliffs of Dover, England, recently aimed a beam of radio waves from a ten-foot reflector across the English Channel. It fell on another ten-foot bowl near Calais, France, twenty miles away, and over this beam the men at Dover and Calais talked.
SHEETS of iron and copper are soaked in milk until tiny quantities dissolve, and the result is fed to sufferers from anemia, by an Atlanta, Ga., experimenter. Tests have showed striking benefit from this strange “metallized milk,” the discovery of Dr. J. L. McGhee, Emory University biochemist.
MOUNTAIN or seashore weather is brought into the sick room by a New York inventor’s device. The “climator,” as the inventor calls it, is built as a sleeping bed. After the patient climbs in, the curtained top is lowered about him. A uniform atmosphere combining radiant heat, proper humidity, and moving air is continually provided by electric controls, and may be maintained day and night at any season.
AN EXAMPLE of what may happen in the future when airplanes become more popular was shown near Chicago, III., the other day. J. V. Neill was trying out a midget plane when his hat flew off. He saw it land in a back yard. Then he flew down, landed in the yard, got his hat, and took off.
BERLIN crowds can now see advertisements projected on the clouds in the night sky, in letters a quarter of a mile high. Were they to follow the streamers of rays to their source, they would find a giant auto train occupying seventy feet of roadway.
STRANGEST of devices to try out aspiring baseball pitchers is a novel target recently introduced in the East. Behind a dummy batter, who faces a home plate, is a back-stop ruled in squares and charted with key letters. The pitcher under trial is required to try to hit any spot the instructor may order, with the various types of delivery at his command.
AN ELECTRIC arc of more than 6,000 amperes recovers gold, silver, and base metals from ore in a new type of electric smelter invented in Oregon. Elbert Dyer, an inventor of Bandon, Ore., and Roland Sutherland, Alaskan miner, who visioned the new smelter, borrowed an electric transformer for their experiments.
THOUGH the average electric lamp is far more efficient for heating than for illumination, the light from a new type of high-power lamp is cold. The new bulb is designed for uses where a minimum of heat is required, as over operating tables in hospitals, for lighting wax models in store window displays, and for projecting opaque objects in a stereopticon.
AN EXTRA sturdy dual-purpose rake that will not clog is a late invention of particular interest to the gardener. The rake thus combines the usefulness of the old-fashioned steel rake used for working in the soil with that of the Japanese bamboo rake for leaves and rubbish.
TELEVISION images appeared on a ten-foot screen the other day in the Chicago laboratory of U. A. Sanabria, twenty-four-year-old engineer. This is the largest television image yet shown on any screen. The secret of Sanabria’s success is a new neon lamp capable of developing the amount of light needed to build up a television image of such large proportions.
REPORTS have long had it that Henry Ford, the man who made cheap auto-mobiles popular, was about to produce a light plane that any man could afford to own and fly. Now Ford’s chief aircraft designer, William B. Stout, announces what he calls “an aerial counterpart of the famous Tin Lizzie.”
Ship Models for All the World Tested in U. S. Navy Yard
TOWING toy-size boats in a tub is serious business at the Navy’s model basin in the Washington, D. C., Navy Yard. The models reveal such things as resistance to water and required power of real ships similarly designed. Merits of propellers are also compared.
Two huge X-ray tubes, one at the California Institute of Technology, Pasadena, Calif., and the other by the General Electric Company, at Schenectady, N. Y., are now being constructed. Dr. Robert A. Millikan and Professor Charles Lauristen designed the apparatus under construction at Pasadena.
SOON to be placed on the market, according to advance reports, is a novel apparatus that will make the air in sleeping and living rooms less humid during summer months. Exactly opposite in principle from standard air moisteners, this de-humidifier will draw moisture from the air.
A VETERAN fire-fighter, John Kenlon, who recently resigned as Chief of New York City’s Fire Department after nearly twenty years at that post, predicts revolutionary changes in fire fighting. One of these days, he foresees, airplanes will supersede automobile fire engines.
LOOSE hammer handles, caused by wedges working out, may be avoided by using a wedge recently placed on the market. A series of projections cause it to bite into the wood of tool handles, holding itself firmly in place.
Two years of sunlight were crowded into a few hours in New York recently when a new wall paper was given a fading test by artificial sunshine. Samples of the paper were stretched over small openings at the base of a large cylinder. Rays from a powerful sun lamp, which was installed within the cylinder, fell on them through the openings.
A METHOD of dividing the musical scale, which may result in new and strange harmonies, was demonstrated in New York City recently by Augusto Novaro, a Mexican of Italian descent. Twenty years of experiments were required to perfect the system, which is based on mathematical calculations and instruments of Novaro’s design.
STRIKING in contrast to the bulk of ordinary seismographs, or earthquake detectors, is the diminutive size of a new instrument recently installed at the University of Pittsburgh. It is called the only one of its kind in the Western Hemisphere.
IF THE squeak of a rusty door hinge, or of a piece of chalk upon a blackboard, sets your nerves on edge, perhaps there’s a reason. When loud and high pitched enough, it is actually deadly to cells and small organisms, investigators have found. Both germs and the red corpuscles of human blood were killed by audible noises, in tests conducted by Prof. O. B. Williams, University of Texas bacteriologist, and Prof. Newton Gaines, Texas Christian University physicist.
A CURVED, trough-shaped nail file placed on the market recently is a useful manicuring tool. Rubbing it across the nail ends, which are held inside its trough, results in nails filed to shape. This novel instrument is made with three sections— one especially for the thumb, one for the little finger, and one for the three middle fingers.
BECAUSE his hobby was fire fighting, Albert T. Bell, Atlantic City, N. J., hotel man and president of the National Fire Protection Association, had a private yacht built for himself that could be pressed into service to fight waterfront fires.
So THAT motorists may travel in comfort, sleeping while riding if they desire, M. A. Montenegro, of Tampa. Fla., has devised a head rest for use in autos. Straps suspend the rest from crosspieces in a car's top. The device is equipped with “ear flaps” to prevent the noise of travel disturbing the sleeper.
BELL notes louder than any ever heard by human ears can be played by a small electric carillon, not much larger than the average radio set. The apparatus, recently developed by a New York City manufacturing firm, also can reproduce bell sounds as faintly as the ticking of a tiny boudoir clock.
A NEW odorless varnish that can be used in refrigerators without harm to foods was announced in a recent report to the American Chemical Society. Varnishes at present in use contain a strong-smelling material known as phenol which is easily absorbed by fatty foods like butter.
A CAMDEN, N. J., manufacturer has just introduced a remotely controlled radio set that uses the standard type of phone dial. The rotating dial is set on a case no larger than that of a small traveling clock. It is operated by the finger or the end of a pencil.
So MANY phone subscribers desire the correct time at a nominal charge, a service provided in several cities, that a new system will soon enable one operator to give many callers the time at once. Pictured above, she announces thus, “When you hear the tone signal it will be exactly 10:45½ A.M.”
A DIAMOND studded automobile, the most expensive in the world, costing $125,000, was displayed recently at Kansas City, Mo. It was built to commemorate the silver jubilee of a dealer’s organization, and is finished largely in silver. To maintain the car requires the presence of a large armed guard to protect its silver, jewels, and fine machinery.
PLEASURE cars and light motor trucks may soon roll more smoothly on “balloon wheels.” Recently an Ohio inventor succeeded in adapting a set of these extraordinary devices, previously used only on airplane landing gear, to replace the conventional wheels and tires of an automobile.
BORROWING an idea from prospectors, engineers of a Pittsburgh, Pa., manufacturing firm have perfected an electric “divining rod” for locating hidden electrical outlets in floors. As changes are made in the arrangement of factories or offices, wiring connections for desk telephones, lights, or buzzers are sometimes covered with linoleum.
Supersensitive camera and high powered incandescent lamps add realism to work in pictures — Mineral oil sprayed by giant atomizer gives appearance of fog thick or thin as desired
ONCE, when it became necessary to shoot a movie scene supposed to take place at night, the actors went through their stuff in broad daylight. Then the film was dyed blue to give the night effect. The result often required a bit of imagination on the part of the audience, especially when the sky was brighter than it could be with the brightest moon you ever saw.
Silver Selenide and a Secret Metal Used by German to Get Electricity from Solar Rays
AS THIS is written, an amazing lamp has burned each day for several months in a Berlin, Germany, laboratory—an electric light run by current created by sunshine! It suggests the possibility of future use of a vast, inexhaustible, hithertountouched reservoir of power.
Emergency calls for long flights have led this flyer into many dangerous and exciting situations—Careful study of route and plane is secret of success♦
THE airport telephone jingles. Someone wants to charter a cross-country plane. It may mean a hurry-up jump to Miami, a rush business trip to Chicago, or an emergency dash with a famous surgeon to a hunting lodge in Maine. But, whatever the call, it spells adventure for the man who pilots the flying taxicab.
WITH the letting of the largest construction contract in its history, the United States Government has begun work on the $50,000,000 Hoover Dam, highest in the world. Six years from now the completed dam will span the gorge in the Colorado River between Arizona and Nevada at the point known as Boulder Canyon.
APPRENTICE barbers at Frankfort, Germany, learn to shave by using strange looking blockheads. Since it is difficult to get customers for the young men who are being taught to use the razor, wooden effigies of human heads are used. These remain calm and quiet while the students go over them with their sharp tools.
CONTRACT bridge players know that it is an advantage for both sides to keep score, in order to keep in touch with the progress of the game, and a novel bridge table makes this easy. Built into its top is a revolving score pad, twirled at a finger’s touch to face any of the players.
AN UNUSUAL reducing machine was demonstrated recently in New York City. A series of vertical rollers completely surround the person using it. They can be adjusted to suit users of different girths. Turning a switch starts the rollers going, literally ironing off excess poundage.
WHETHER every cylinder of your car is firing properly is easy to see when the motor is fitted with a set of new transparent spark plugs. The insulator of each plug is made of a glasslike material having great resistance to heat, provided with ridges to give a cooling effect and make the glow visible.
SOMETHING new in aquatic sports was demonstrated at San Pedro, Calif., the other day, when a dare-devil surf rider took a tow from a blimp for the first time in history. Trailing at the end of a 200-foot rope, attached to the Goodyear baby dirigible Volunteer, Elmer Peck thrilled spectators by a program of acrobatic feats.
AN ELABORATE electrical system for posting scores eliminated errors and speeded the play at the recent national bowling tournament held in Buffalo, N. Y. Two thousand six hundred and thirty-nine teams kept thirty-two alleys busy for a week, and yet every bowler and spectator could tell at a glance how the scores were going by glancing at the large bulletin boards made possible by the electrical signalling.
A NEW device that can be screwed into the spark plug hole of one of the auto’s cylinders turns that cylinder into an air pump that will produce two and a half cubic feet of free air per minute. This much air is sufficient to spray oil paint, germicide, insecticide, and similar liquids.
A HANDY little device, invented by Mrs. Isobel Brubaker, of Los Angeles, Calif., calculates contract bridge scores quickly and easily. Two white disks bearing numbers and scoring figures rotates between composition holders. Projecting slightly beyond the edges of the holders, the disks are easily turned by pressure of thumb and fingers.
ENGINEERS at the General Electric Company’s plant in Schenectady, N. Y., have given photo-electric cells the job of checking time in two different ways. Faced with the problem of comparing the company’s master clock with the Government time signals on a daily schedule, they used a photo-electric cell to avoid any mechanical interference with the clock.
Two Los Angeles, Calif., youths recently turned an ingenious idea into a profitable occupation when they evolved a plan for making house numbers more plainly visible to passing motorists. When they appeared before municipal officials, their scheme to paint house numbers in large type upon a whitened section of curb met with approval and they readily obtained a permit.
THE sea isn’t always salty. Recently explorers found a thirty-foot surface layer of fresh water at some places in the Arctic Ocean. Their explanation of the apparent paradox is that melting snow and ice from glaciers and icebergs supplied the fresh water.
ONE of the latest pieces of equipment for German fire fighters is a novel extension ladder that can reach a height of 125 feet when fully extended. It is mounted on a motor truck of its own and raised and lowered by machinery. A rotating base supports the ladder in such a way that it can be raised in any direction without moving the truck.
A REMARKABLE small-scale model of a human skeleton was completed recently by Miss Catherine Doret, a Los Angeles, Calif., dental assistant. Hard rubber, gold, silver, and dental plaster were used in making the skeleton. All of her spare time for two years was given to the job.
ADDED to the Harvard University Museum at— Cambridge, Mass., the other day was the skeleton of a tiny camel that once roamed the Western plains of this country. It was found at Agate Springs, Nebr., by geologists of the university’s research department.
STUDENTS of marine life or amateur photographers now may take underwater pictures without wetting their cameras. Edward Sanderson, of Portland, Ore., demonstrated recently that this could be done by the aid of the new electric photo flash bulbs.
MOTORISTS in foreign countries find the word “stop” on traffic control signs almost everywhere, regardless of the language spoken. Tourists traveling over the mountain roads in Albania saw this English word on traffic signs as frequently as signs printed in the native tongue.
AN ARTIFICIAL corn leaf 160 feet long by thirty-six feet thick will be one of the exhibits at the Chicago International Century of Progress Exposition to be held in two years. Visitors will be able to walk through the huge leaf, much as tiny germs might pass through the leaf itself.
A CONVENIENCE on German railway trains is a device by means of which passengers may open sleeping car windows themselves. Without rising from his seat, a traveler grasps a small lever at the window sill, opening the window quickly and easily.
A MONKEY wrench that tightens its grip on nuts or boltheads the harder it is applied is a new tool for mechanics. It is made by a Binghamton, N. Y., firm. A round nut in front of its handle regulates the jaw opening to the approximate size required.
BORROWING an idea from builders of big guns, a Chicago, III., manufacturing firm has designed a new thief-proof money holder for commercial establishments. A heavy steel cylinder is fitted with a circular hinged cover like the breechblock on a big gun.
COIN-IN-THE-SLOT typewriters for public use in hotels and postal and telegraph offices have been designed by a German firm. Putting money in the slot, a depositor may make 1,000 strokes with the machine. Attached to it is a device counting strokes as they are made, showing the user when he is approaching the end of his number.
EXTREMES in the sizes of electric lamps were demonstrated recently at Cleveland, Ohio, when one of the new photographic flashlight bulbs was shown beside a monster incandescent lamp of 150,000 candlepower. The flashlight bulb could hardly be seen beside its huge brother.
DESIGNED for use in washing dust from motor cars is a rubber sponge put out by a Trenton, N. J., manufacturer. Fitted to a short length of hose, water flows through the sponge before reaching the auto’s paintwork. Both washing and scrubbing are done in one operation by use of this device.
ONE of the latest of Uncle Sam’s mobile weapons for war on the land is a light armored motor car. This machine, recently tested at Fort Eustis, Va., mounts two machine guns in a turret. It can make sixty miles an hour on the road and can go 200 miles on one filling of gasoline.
A MECHANICAL flying instructor was shown in Los Angeles, Calif., recently by its inventor, George Bosson, of that city. The student pilot sits at a standard set of airplane controls—stick, rudder bar, and throttle—with a regular instrument board before him fitted with blind flying and engine-recording instruments.
A NEW wasp of the air recently delivered to the British Royal Air Force is a flying gun mount. The wicked little high-speed single seater carries no fewer than six machine guns, fixed so their fire focuses on one point ahead of it. Like the big guns of a battleship, all of which may be fired by one man, all six of the new fighter’s machine guns may be fired by the pilot.
NOT long ago two squadrons of naval planes, carrying seventy-two men, wandered too far from their mother ship, the carrier Lexington, and became lost at sea. They found their way back safely only after dark, when the carrier’s searchlights pointed the path home.
LOST over the shark-infested Pacific Ocean off Panama—and out of gas! Chief Aviation Pilot Verne W. Harshman, U.S.N., had strayed and could not find the aircraft carrier Langley and the airplane fleet. Now his motor sputtered and died. The plane, a land-flying type, splashed into the sea.
HIGH amid what appears to be a tangled mass of girders, mechanics are installing motors that will drive the huge Navy airship Akron, largest in the world, now nearing completion at the Goodyear-Zeppelin dock in Akron, Ohio. They will break all precedent in airship construction by being placed inside the hull.
SPECIAL crockery for serving meals in passenger planes was demonstrated in Los Angeles, Calif., the other day. Dishes that could not spill their contents or slip off tables while the plane made steep banking turns were shown. The plates, cups, and glasses were held in place on tables by spring clips instead of wooden racks used in steam-ships for similar purposes.
IT TAKES four days for an Army artillery battery to travel overland from France Field, Canal Zone, to the little town of Rio Hato in the Panama jungle, 120 miles away. But a complete field gun battery of four three-inch guns whizzed through the air the other day to make the trip in scarcely more than an hour.
Industry Uses Invisible Vibrations to Make Pictures of Insides of Giant Forgings or Household Utensils in Search for Flaws
CLAYTON R. SLAWTER
MAGIC and a new factor of safety have been added to industry by the use of X-rays, those tiny invisible vibrations of ether so small that some have two trillion to the inch. Long the useful servants of the surgeon and doctor, X-rays now are making pictures of the inside of solid masses of steel and of the hidden parts of household utensils and showing, on photographic plates, weak spots in giant forgings— thus aiding in a new way in the protection of life, limb, and property.
IN THE world of crime, sheep can now be separated from goats. Sheep are those who can and will reform. Goat crooks are those who can’t and won’t. New Jersey state experts, wise in the ways of a crook, have given 10,000 mental tests to jail and reformatory inmates during the past two years.
Tests with Movie Camera Prove That Our Legs Are Pendulums
Do you know that laws of mechanics set a limit to the length of stride you can take and the speed at which you can walk? Use of movie discloses locomotion secret and shows why you run faster than walk.
WALK along the street at your natural, brisk pace, watch in hand, and count your steps for exactly a minute. If you are of average height, the number will be a few more or less than 120, or about two steps a second. Now count the steps of some man about your height who is walking ahead of you, but count only the heel strokes of one of his legs.
Oil and Gas Preserve Eggs By a Process That Keeps Them Fresh for Months
BY ADDING “gassing” with carbon dioxide to a new oil treatment for the preservation of eggs, T. L. Swenson of the United States Department of Agriculture has greatly improved the process. Indeed it is predicted that the commercial application of egg “gassing” will make strictly fresh grades as cheap in midwinter as in summer.
Two Pittsburgh, Pa., youngsters are the proud possessors of an auto they built themselves. Joe Smalley and Don Graham recently got an old washing machine gasoline motor which they installed in a “chassis” built of boards and old wheels. The chain-drive vehicle, it is said, has attained a speed of twelve miles an hour.
CAPABLE of picking up two pounds of metal, this magnet is made primarily to aid the auto mechanic in picking up metal cuttings, broken pieces, and nuts and bolts. It can be inserted into the transmission to remove bits of metal, and it can be used to insert bolts and screws where the hand cannot reach.
A REMARKABLE mechanical man was put on exhibition in St. Louis, Mo., the other day. Unlike earlier devices of this kind, which only obeyed whistled signals, “Mr. Vocalite,” the new iron man, responds to words of command spoken into a telephone mouthpiece.
A WINDOW ventilator that strains dust and noise from air as it enters a room is a new development of a Chicago, III., manufacturing firm. Windows are partly raised and the throat of the device, slipped into the opening, completely fills it.
How long after you pull the trigger does the charge of shot come out of the muzzle of your gun? Twenty-five to thirty-five 10,000ths of a second, say gun experts who calculate this speed from tiny scratch marks on a metal rod falling through a hole in a bench.
HARVARD University scientists plan to use dynamite as a yard-stick in measuring deposits of gravel and earth left by glaciers that once covered large parts of the North American continent. Shots of the explosive will be set off at varying distances from a portable seismograph.
FUNCTIONING as the motorist’s leg does in exerting pressure on an automobile brake, a pedal pressure measuring device has just been brought out by a brake testing machine manufacturer. Adjustable for angles and length, it is operated by compressed air and is equipped with gages that tell the number of pounds pressure and so record the amount of pedal push.
EGYPTIAN mummies at the Brooklyn Museum in Brooklyn, N. Y., were examined by a new method the other day when X-ray photographs were made of them. In this way, many interesting facts were discovered. One of the mummies, that of a woman, was found to be in perfect condition.
A NEW type of leather tobacco pouch holds both tobacco and a pipe of ordinary length. The pipe fits into a separate compartment at the bottom of the pouch, and is held in place by a strap fitted with a snap button. The tobacco is removed from the top of the pouch, which is closed with a zipper fastener.
HIGH altitude tests for airplane engines made while they remain on the ground is the novel idea of an Italian firm of airplane engine builders. In testing a new or overhauled motor, it is mounted on a large auto truck and taken to the top of a high peak in the Italian Alps, 10,000 feet above sea level.
“HOT PAPA,” least-known member of Uncle Sam’s Navy, recently posed for his picture aboard an aircraft carrier. Few outside the service knew of his existence until it was revealed during the recent Panama maneuvers (P.S.M., May '31, p.70).
WIRE wheels of an automobile can be brightened up by application of shiny metal sleeves fitted over the spokes. These coverings, the product of an auto-mobile wheel manufacturing firm in Detroit, Mich., are made of bright steel that will not rust or stain.
GROTESQUELY attired, members of a British Red Cross unit carry out first-aid drills in gas masks. They have been ordered to wear their masks so they may become accustomed to breathing in them while doing hard work. Both nurses and stretcher bearers complete all the evolutions of their drill wearing the anti-gas devices just as they would in an emergency.
FARTHEST north for the monkey tribe is believed to have been claimed by a species that once, far earlier than history records, inhabited what is now Holland. Fossil remains recently discovered in that country show these monkeys to have been similar to those now found around Gibraltar, although somewhat larger.
BROADCASTING organ music from a soundproof pit is a new stunt worked out by Vernon A. Trigger, chief engineer of radio station WBZ, Springfield, Mass. Hitherto organists have been unable to hear their own broadcasts and as a result have found it difficult to play in a way that will meet the peculiar requirements of the air.
WHEN Sir Hubert Wilkins’ submarine Nautilus plunges under the Arctic ice cap on her voyage to the Pole this summer, she will not be entirely blind. Two huge electric headlights, of 1,000,000 candle-power each, will cast beams of light nearly 100 feet ahead of the vessel.
PUPILS at an English aviation school have all the thrills of real flight without leaving the ground. They get their final training before soloing in a device invented by two engineers of Farnham, Surrey. A small plane, complete with controls, propeller, fuselage, and cockpit, is mounted on a pivot so it can move in any direction while fixed to one spot.
ENGINEERS in Chicago, III., are experimenting with different lighting effects to be used at the World's Fair which will be held in that city in 1933. When it is finally opened to the public, the visitor will see light used for decorative purposes on a scale never before attempted.
IF HUMAN laborers were paid only what their actual physical energy is worth, the average workman would receive a cent an hour. So concluded Prof. William Boss, of the University of Minnesota, after testing typical men with a device that compares their power directly with that of engines, windmills, and water wheels.
LINCOLN CHARLOT, an eighteen-year-old schoolboy of St. Paul, Minn., showed the other day what can be accomplished by ingenuity and cast-off kitchen utensils. He built himself an ultra-violet or sun-tan-producing "health" ray lamp, using an old bread pan as the casing.
How much energy does a human being consume doing hard manual work in high temperatures? That is the question scientists are seeking to answer by placing strange looking equipment on the back of a student at the Kaiser Wilhelm Institute, Dortmund, Germany.
A MECHANICAL calendar of many uses recently has been placed on the market by a Chicago, III., manufacturing firm. Installed in an automobile, it will notify the driver when to change oil and put water in the battery. It also can be arranged to control industrial machinery, electric signs and so on.
GREEN and red flashlights now control movements of planes at the Washington-Hoover Airport, Washington, D. C., Thousand-watt lights are contained in two round sheet iron barrels, each of which can be capped with a red or green lens. The barrels are fitted to each end of an iron crossbar attached to a revolving stand on top of the airport.
ONE of the latest recruits to the ranks of the army of more than 150,000 amateur movie makers in this country is Albert Einstein, father of the theory of relativity. During his recent stay in California, not far from the hub of the moving picture world, the illustrious German scientist doubtless came under the movie influence of that section.
CHIOGNA, a Swiss ski jumper, recently claimed the title of the “fastest human” as the result of trials with electrical timing devices on a skiing course in Switzerland. The timers showed he attained a speed of 81.82 miles an hour at one point in his arrowlike descent.
LUMBERMEN on the Pacific coast are using an electric branding iron recently perfected by the General Electric Company. A forked handle carries a holder at one end in which a removable brand is inserted. It takes about fifteen seconds to mark a timber with a brand that can be removed only with a saw or chisel.
AT TWELVE o’clock noon the chimes of “Big Ben” ring out—not from the English towers of Westminster, where the famous bell swings, but from the Camden, N. J., City Hall. The tone of its English prototype is reproduced without a bell at all, through an electric device that imitates bell sounds.
RIVETERS clatter and steel clangs on steel on the shores of the river Clyde at Clydebank, Scotland, where workmen are busy laying the keel of the biggest liner in the world, the new Cunarder that is expected to cross the Atlantic to the United States in four days.
PROSPECTIVE bus drivers are taught how to manage their vehicles in a “skid” on a special skidding ground at a London, England, training school. The ground is on a slope, and the surface is regularly dressed with a thick layer of oil and grease over which water is sprayed.
EVEN riders in taxicabs will no longer be immune from advertising signs. A device soon to make its appearance in New York will flash a continuous program of illuminated advertisements before the passenger’s eyes. The new signs will appear in 20,000 cabs in New York and other cities this year.
RAISING autos by their wheel rims is accomplished by a novel jack recently devised by an Illinois inventor. This screw device is operated by a long crank handle, which makes stooping unnecessary. The jack is placed in position and the car lifted until the tire is clear of the ground.
A WIRE device, developed by an Englewood, Colo., inventor, locks nuts on big bolts. The ring of wire, which fits into threads on the bolt, is made slightly small for them. It is opened up by pressing against two “ears” formed in the wire. After being placed over the bolt these are released and the ring clamps itself around the bolt by the spring in the wire.
SAWDUST mixed with cement was used recently at the Oregon State Agricultural College as flooring material. Floors made of this mixture were, when a little thicker than those of sand and cement, equally strong and much warmer.
A RUBBER cap, molded out of soft fubber, has been patented for use on the heads of steel chisels. It keeps fragments of metal from flying from chisel heads and injuring workmen. It also prolongs the life of the chisel about three times. With the cap on, the chisel may be used until the head is considerably shattered before it needs regrinding.
FUSEES, resembling those used for railway signaling, have been perfected for smothering chimney fires. A heavy paper tube about twelve inches long, with a handle at one end, contains the substance which, when heated, releases a smothering gas.
WORKING under almost incredible difficulties, a party of American motion picture people recently succeeded in making sound picture in the heart of the equatorial jungles of the Dutch East Indies. A base for developing and recording film was established at Singapore in the Federated Malay States.
A FOLDING reflector for the photographic flashlight bulbs, that take pictures without the aid of powder, is a new accessory for the amateur photographer. It is a cone of aluminum-coated paper and cardboard. An eight-sided disk of cardboard with a hole in the center is slipped over the bulb first.
BORROWING an idea from aircraft, H. B. Hendrickson, of Washington, D. C., rigged up an air-speed indicator as a radiator cap ornament on his auto. A venturi nozzle, a somewhat conical-shaped tube, is mounted above the dial of the indicator.
A NEW golf game was played recently in Los Angeles, Calif. Brightly-colored canvas cones, several feet in diameter across their openings, are raised slightly from the ground. They are placed at varying distances from players armed with irons, who attempt to pitch shots into them.
RAY STAFFORD, California glider pilot, decided the other day to take photographs of himself while flying his craft. He focused a camera on the pilot’s seat of his glider and strapped it to one of the wing struts. Its shutter was worked by a string within easy reach of his hand.
THE unusual spectacle of alligators shooting the chute is to be seen at a Los Angeles reptile farm. When a wooden slide was built beside an artificial pond, they took keenly to the new sport. Without difficulty they learned to clamber up a stairway to the top of the slide and coast down it, legs askew, landing with a splash.
WINDOW frames, sidings, and other forms of lumber are now on the market coated, not for decoration, with aluminum paint. The paint seals the wood against moisture, so that paint applied later will not crack or peel off. A number of mills have adopted the practice of first drying their lumber, then applying the moisture-proof coat of aluminum.
A CONVENIENCE for shipping clerks who have to label packing cases is a fountain pen marker recently developed by Edward S. Garvey, of Clayton, Mo. Ink is contained in a hollow handle, at one end of which is a felt tip. Through this, the ink escapes to the work in response to a slight pressure on the tip, which opens a small valve in the handle.
A MOTOR-DRIVEN sweeper similar in principle to those that keep the city streets clean is now in operation at the entrance to an Oakland, Calif., yacht harbor. Instead of observing the accepted eight-hour custom, the water sweeper is turning day and night keeping back oil scum, driftwood, and other floating debris.
TRYING out latest methods of gassing criminals barricaded in buildings, Boston, Mass., police officers tested the effects of tear gas on fellow members of the force the other day. Three policemen were stationed in a building at the police training school while tear gas shells from a new type gun were fired into it.
FOR lighting the paths of night-flying pilots, powerful new experimental air beacons are being installed at different points in the United States. They are unique in that they can throw a beam of light across the skies in two directions at the same time.
STRANGEST of commuting methods is that used by W. H. Slater, a dock employee of Kent, England. Each morning when he starts to work he hoists sails on his conveyance, casts off its moorings, and sails away—down railway tracks to his job five miles off over the tracks of an old coal mine abandoned some time ago.
ARE the diamonds in your family jewel chest worth between $150 and $200? If so, they represent the average share possessed by American families. According to a recent estimate, the value of diamonds owned in the United States exceeds four billion dollars.
GOOD material for a heavy-weight fighter or wrestler was this gorilla, the skin of which is being mounted at the Smith-sonian Institution in Washington, D. C. When roaming the jungles of equatorial Africa in the prime of his strength, this monster stood five feet four inches high, weighed 400 pounds, and had a reach of ninety-seven inches, about twenty inches longer than that of a big man.
A NOVEL periscope recently developed by a Brooklyn, N. Y., manufacturing firm enables workmen to peer inside paint or oil barrels to see if they are completely empty or clean. In a hollow tube a number of mirrors are mounted, so that when the tube is thrust into the bunghole a view can be had of the barrel's interior.
A WRECKER bar devised by William F. Henderson, of Colfax, Wash., can be used to draw nails. A roller carried in a frame íear the claws allows the bar to move. As a result a nail is drawn upward in a straight line instead of in the arc of a circle, and wall come out with ease without bending and binding.
DUTCH business men may now hold conferences over the phone. A new telephone service put on trial in Holland the other day permits from three to six subscribers to talk with each other over the phone at one time. The new service is finding a wide use in offices.
SUPPOSE that you are planning a day’s trip into the country with friends, and this question arises: Will there be moonlight for the return journey, and how much? If you memorize the rule, you can answer the question on the spot. Here is the rule, followed by a worked out example.
Small Home Builder Builds His Own House— All His Pet Theories Prove Good
Small Home Builder Builds His Own House— All His Pet Theories Prove Good
HOSPITAL HAS AIR LOCK TO TREAT “BENDS”
JAMES F. CALNON
AS A HARD boiled builder of small houses, I’ve spent most of my life following the plans of many architects. It has been a pleasure to coöperate with most of them because they know their business as well as I do mine. Of course now and then I have had to argue with some architect whose grand ideas couldn’t possibly be interpreted in terms of concrete, wood, plaster, or any other building material.
COVER SHOWS HEAT. Built into this cover is a thermometer by which the temperature of the skillet, bake pot, or Dutch oven can be observed and regulated to any degree. HOT WATER ON DEMAND. Louis Emans, of Willmar, Minn., exhibits his recently invented portable hot water heater.
A MAN came into our office the other day. He had an idea that he believed would be useful to us. He stated his proposition clearly and with a grasp of detail that was amazing. Nothing had been overlooked. There was no sign of loose-jointed and foggy reasoning.
Best Portable Radio Receivers Built from Diagram on This Page Will Win Cash Awards—Four Rules to Follow
HERE is your chance to build yourself a fine portable radio receiver and win a cash prize for doing it. The contest is open to everybody except, of course, the members of the staff of POPULAR SCIENCE MONTHLY or their families. On this page is a diagram of an electrical circuit.
A MATEUR radio builders and experimenters will soon find that it does not pay to rush things. The more you hurry, the more likely you are to make wrong connections with disastrous results to your tubes or other equipment. This applies with special force to experimental hook-ups of a temporary nature.
RADIO engineers are confronted with a whole new set of problems as the result of the enormous amplification possibilities of the modern screen grid tube. The chief problem has been to find a way to control the volume of the super-powerful multi-stage screen grid receiver without introducing severe tone distortion or the form of interference known as “cross modulation” or the jumbling together of two stations.
Gas Lays Down the Law About Taking Chances and Tells Why Fool Drivers Fail to Protect Themselves and the Public
GUS WILSON fingered the crumpled fender while he gazed appraisingly at the other damaged parts on the front end of the car. “Lemme see,” he rumbled, counting on his huge fingers. “First there’s the mudguard. That’s a total loss—beyond fixing.
Proper lighting of subject is half the battle—Beginning a new series
FREDERICK D. RYDER
CLEAR, sharp photographs are with-in the reach of everyone who owns a camera, whether it cost a few dollars or several hundred. All you need to do is practice the simple rules of photography outlined in this article and others to follow. By doing so you can learn to take pictures of professional quality.
WITH the addition of a folding shelf and front piece as illustrated, an ordinary three-burner camper’s gasoline stove has several advantages. Its heating efficiency is increased, it does not spatter so much grease around, and it allows biscuits, pies, and other food to be warmed on an unlighted end burner while the other two burners are used for cooking.
EXPENSIVE looking raised letter signs can be made cheaply with the aid of any high-grade wood composition of the type intended to be applied in a plastic state. Paint the background black, draw the letters in outline with a scriber, and along the center of each stem drive a row of carpet tacks, letting the heads project about ⅛ in.
THE loss of a particular key, or bunch of keys, often proves to be quite an inconvenience. I find it a good plan to make a blueprint of each key that I have, and under each print I letter the number of the key and the name of the lock company. It is thus easy to have a duplicate key made if necessary.
WHEN alarm or other clocks of the cheaper variety come to the end of their usefulness and no longer run, their life can be renewed, unless the spring or some other part is broken, by removing the works from the case and soaking them for a day or so in a bowl of kerosene.
BY ATTACHING a 4-in. paintbrush to a garden hoe with an iron C-clamp as illustrated above, one home owner saved himself many hours of tiresome kneeling and bending when he undertook to coat the floor of his basement with a dust proof cement paint.
“GIDDAP, Spot! We’ve got to go to the store for mother.” What boy couldn’t say that willingly and with a cheerful voice if he had a fox terrier dogcart like the one illustrated at the right? This cart is made from a prune box 12 in. wide, 15 in. long, and 6 in. deep.
FROM the lumber rack in his well-equipped basement workshop, Frank Bradley drew a short block of scrap wood and held it up for Jack Horland's inspection. “Dry or not dry?” he demanded. “That’s more than I can tell.” “Then just listen to this.”
Novel Ball-and-Chain Desk Set Portrays a Prisoner’s Dream
CHARLES HERBERT ALDER
HERE is a genuine novelty in desk sets that is easy and inexpensive to make, requires few tools and very little material, and offers the craftsman an opportunity to exercise his skill, ingenuity, and imagination in elaborating the idea as much as he desires.
A MATEUR craftsmen who experience difficulty in obtaining plans for just the type of furniture they desire will do well to turn to commercially made pieces for designs, over-all dimensions, and general methods of construction. Indeed, woodworkers who exercise a little ingenuity by scouting through furniture stores and gift shops and scrutinizing advertisements, often will find excellent suggestions which can be used in building pieces of their own.
THIS little rubber-driven auto racer will go farther and faster than any similar toy the writer has ever purchased, regardless of price. The motor, which is a heavy rubber band nearly twice as long as the car, is so arranged that the car continues coasting after it is completely unwound.
BECAUSE it has what is known as an airfoil or all-wing fuselage, the Burnelli twenty-passenger transport plane forms an unusually interesting study for the model maker. The fuselage is more than twice as wide as the cabin of other transport planes of corresponding capacity, and it is shaped like the section of a wing.
Clarence E. Mulford gives plans for building his Model of Old Fort Union
Historic trading post on the Missouri where fur trappers and Indian fighters forgathered
THOSE model makers who read last month’s introductory article on Fort Union (P.S.M., May ’31, p. 91) will understand exactly what my feelings are when I say that I get a great kick out of this kind of work. I have been accused of being a hard-boiled sentimentalist—whatever that means—because tears were in my eyes when I paced off the foundation adobes of Bent’s Fort, and because I was watery-eyed when I wandered along in the wheel ruts of the old Santa Fé Trail.
IT IS frequently necessary to turn a wooden handle, knob, or similar piece with a deep hole in one end. In such cases the outside turned surface often is far from being concentric with the hole because it is so difficult to bore a deep hole without having it run off to one side.
IF YOU bind your own magazines or do any work which requires a number of sheets of paper to be trimmed uniformly, you can obtain professional looking results with an ordinary plane blade that has been sharpened to a keen edge. The trimming should be done when the first glue coat on the back has almost set and just before the back is to be rounded.
A FiVE-CENT glass salt shaker containing a rolled wad of ordinary white blotting paper makes an efficient, clean humidifier for tobacco jars. Merely immerse the loaded shaker in a bowl of water until it has soaked up moisture and wipe the out-side of the shaker dry so that particles of tobacco will not adhere to it and clog up the holes.
BUILT to fit the rest holder of your wood turning lathe, this simple tool grinding attachment makes it possible to obtain the same angle each time a tool is ground. No dimensions are given for the rod since they depend on the lathe. File the rod for about ¾ in. at the top until it is only ¼ in thick, and drill a hole through this portion for the pivot bolt.
This easy step-by-step method of making a perspective view from ordinary plans gives you the answer to this question
J. D. GILBERT
HOME builders who are not accustomed to reading blueprints will often experience difficulty in visualizing how the new house will look. They cannot form a clear mental picture of the house from the individual floor plans and elevations.
A BROKEN string in a tennis racket is an unfailing source of annoyance. It is quite possible, however, to insert a new length of gut in a manner that will neither affect the playing qualities nor leave unsightly knots on the outer edge of the racket.
THE common method of removing dents in the auto body is by pounding from the inside with a soft hammer. To do this it is almost always necessary to take out a large section of the upholstery to get at the back of the dent. Figure 1, above, shows a way to do the job that will work in some cases, and if it does a large amount of time is saved.
WHAT can be saved in even a small machine shop by reclaiming dull, worn, and damaged high-speed tools is surprising. In fact, it amounts to far more than anyone would imagine without a record of the actual figures, as was pointed out in a previous article (P.S.M., May 31, p. 98).
NEVER straighten tool steel when cold, as it is likely to warp in hardening. Tungsten carbide tools should be given as much support as possible, and excessive overhang should be avoided in order to eliminate chatter. It is much easier to change a design than to use a “putting-on tool” or a melting pot.
IN MY work I occasionally find it necessary to make certain records in the form of graphic charts. When the finished “curves” on these charts zigzag up and down, there is always the risk of blotting the work. This difficulty led me to make use of the “wrinkle” illustrated.
ON A night job recently, I found it necessary to use a micrometer, but, as often happens under such conditions, the light was so poor that it was impossible to take an accurate reading. An older mechanic, who wore very strong magnifying eyeglasses yet could not read the micrometer, suggested that I try his glasses.
Convenient truck for welding outfit—How to make a set of interchangeable cone centers for the lathe
NO KNOWLEDGE of chain hitches, bends, or complicated knots are needed in attaching the safe, positive-acting lifting rig for heavy work illustrated in Figs. 1 and 2. Once the adjustable arms are placed and the weight of the casting is put on the rig, it will not let go until the weight of the work is removed.
A New and Easy Way to Make Small Storage Batteries
Tiny cells, incased in celluloid, provide efficient source of power for ship models
MARK A. COOPER
SMALL storage batteries for use in ship models or for experimental purposes can be made without difficulty to suit any space available. It is necessary merely to have the plates ⅝ in. lower than the maximum height of the space into which the battery is to fit, and ½ in. narrower than the maximum available width.
SOME time ago while doing a rush job, I found that I was in immediate need of a wire buffing wheel or scratch brush. Not having the time to go out and purchase the type of buffer I wanted, I worked out the idea illustrated above. From some old wire screening I cut sixteen 6 in. diameter circles.
THIS fence, although easily portable, is surprisingly strong and firm. Built entirely of 1 by 4 in. lumber, it is made in sections 10 ft. long. The horizontal boards are placed 12 in. on centers, and the uprights are 5 ft. high. Every other section has three boards arranged in a sort of “A” shape at each end, as shown; otherwise all the sections are exactly alike.
A CHAIN is as strong as its weakest link, and a home workshop is as efficient as its motive power. We may have the finest of tools, the best in machines, and the ability to turn out excellent work, but if our motors are worn and fail to supply the rated power, our home workshop machinery will probably bring us more grief than pleasure.
THE turntable stand illustrated will be found helpful in painting a ship model, especially as it holds the hull so that the entire bottom can be painted without interference. When the painting has been done, the pin supports are replaced with regular cradles, which hold the model steady while it is being rigged.
The frame is made of silvery looking monel metal which will never tarnish
NOT often will you see a gold-fish aquarium with a silvery frame-work of that new and modish material, monel metal, yet there are few more attractive decorations for the home. The metal is brilliant in appearance, does not tarnish, and is easy to work.
SCALE model airplanes of the nonflying type can be equipped with realistic radial engines by building the dummy cylinders from small copper washers or riveting burrs. Use two sizes of washers arranged alternately as shown, and. fasten each group to the nose of the model.
SAFETY pins can be converted into excellent shock absorbers for model airplanes. Obtain a pin of a size suitable for the model you are building; then cut off the ends as shown in the illustration below and slightly flatten the wire forming one leg of the remaining V.
AS A chain is no stronger than its weakest link, so is a fishing line no stronger than its knot, and most knots cut themselves at a strain of about three-quarters of the breaking point of the line. The accompanying illustration shows how one sportsman ties on his fishhooks in such a way that the knot is relieved of the direct strain.
Jack Hazzard Tells How to Make A Tent without a Fault For Auto and Canoe Camping
FOR auto or canoe camping the most convenient and comfortable tent is one that can be heated easily from a back-log fire and requires a minimum of pegs and poles. Really comfortable tents are often prohibitive in price. Often, too, their dimensions are cramped or they cannot be well ventilated.
AFTER many hours of research spent in reading books and visiting museurns, James Doyle, expert craftsman of Niagara Falls, New York, set about the task of building what he feels will be one of the most completely and authentically furnished doll’s houses ever constructed.
EVERY gardener has to guard against two kinds of insect pests, speaking broadly—those that eat the foliage and those that suck the sap. These require entirely different methods of spray control because poisons that kill sucking insects will not always destroy leaf-eating insects, and others that control leaf-eating insects rarely kill sucking insects.
SILKEN garments must be laundered frequently, and it is often necessary to dry them indoors. For this purpose, the little dryer illustrated is convenient because it can be hung from any available projection. When not in service as a dryer, it may be used as an ordinary dress hanger, and undergarments and hose to match may be fastened to the clips so the complete ensemble is ready for wear.
WHEN a student in a high school wood turning class, I was asked to design a gavel so the head would not fly off. My solution was to run a metal rod through the handle and head with a countersunk washer on either end of the rod, as shown in the accompanying drawing.
SATISFACTORY garden hose coupling washers can be cut from pieces of old hose. A guide to aid in the cutting can be made by boring a hole the same diameter as the hose in a block of wood and inserting the hose through it until it projects about ⅛ in.
WITH this movable toilet case or dressing mirror, a bureau, a table, or even a tastefully draped packing box can be changed into a convenient dressing table. Since the design suggests the late eighteenth century, mahogany seems the most suitable wood, although either walnut or red gum will be an excellent substitute.
expense of lacquer thinner has ted you to put away lacquer without cleaning them with abso-oroughness, take a pint bottle to a or paint store and have it filled with parts of denatured alcohol and ace-This is practically as effective as the er for cleaning the hands and the although the brushes might have final dipping in thinner.
WOOD turning is done in two ways —by cutting and by scraping. The difference between them depends on the position of the tool rest and the angle of the cutting edge with relation to the work. On faceplate work, scraping is done almost exclusively, but on work between centers the tool ordinarily is held in such a position that it will cut rather than scrape off the chip.
MANY washing machines are discarded because they are obsolete in design and unsatisfactory in operation, but their motors are usually in good condition and can be salvaged for other purposes, such as driving small home workshop machines.
ANYONE who has occasion to prepare small quantities of quick, hard-setting mixtures such as litharge and glycerin, plaster of Paris, plain water putty, and similar materials will find that he can do the work quicker and with less muss if he will use one half of a small rubber ball as a mixing bowl.
MANY a home owner has noticed the wrought iron hinges with which architects so often ornament the massive doors of fine residences. Because it is both unusual and decorative, this type of hardware gives a touch of genuine individuality, but it is expensive.
AT PRACTICALLY no cost, a convenient, heavy-duty extension light for the home workshop can be made from an old automobile luggage carrier, a headlight and reflector, two door hinges, an old extension cord and key socket, a scrap piece of pine, and some washers, bolts, rivets, and paint of the desired color.