WELL, boys, I'm all set for a killing," announced Howard Bullard, as he and three cronies sat down and began to deal the cards for their weekly bridge session. “Don’t be too sure,” suggested John Snyder. “I seem to remember that you were the big loser last week.”
WHILE radio engineers in industry have been making real strides in designing radio receiving equipment that comes closer to approaching the ideal, the Popular Science Institute of Standards has been concentrating at the same time on the development of more discriminating and precise tests for radio sets.
“I REALLY was not aware that POPULAR SCIENCE indulged in humor as a reading of your list of thirty-one geniuses would indicate. Certainly, if this list is to be regarded seriously, it is an insult to mature intelligence. Thirty-one geniuses, of whom at least nineteen are American—my dear sir! In the compiler’s obvious zeal for a ‘hundred percent American’ list, I cannot understand why Horatio Alger and ‘Scar-Face Al' Capone were omitted.
ENTIRE Film Industry Being Revolutionized As 400 Theaters Show Pictures That Speak and First Great Full-Length Talking Drama Is a Reality—Complete Musical Comedy Is Arranged For and in a Few Months It May Be Produced in a Thousand Auditoriums—How Remarkable Inventions Give Voice and Music to Silent Screen
ALDEN P. ARMAGNAC
WILL talking movies, newest competitor of the silent drama, eventually usurp its place? That is the question on the lips of everyone who has watched its phenomenal spread throughout the country. Today the “movies you can see and hear” are presented in more than 400 theaters—from the Roxy in New York, seating 6,200, to the Sun Tower in Los Angeles, with a seating capacity of 900—and by the first of the year, it is expected that such theaters will number a thousand.
The Whole World Watches Heroes of Modern Invention Wage Grim Battle to Save Nobile’s Men from the Ice
IN A banquet hall at Oslo, Norway, a few weeks ago, famous explorers of the Arctic gathered to honor Capt. George H. Wilkins and his pilot, Lieutenant Eielson, for their daring airplane dash from Alaska across the Polar Sea. Among the guests was Capt. bald Amundsen, discoverer of the South Pole and hero of the polar flight of the dirigible Norge in 1926.
Firemen Idly Watch While Walls Topple and Effects Of the Flames Are Recorded
H. C. DAVIS
TWO brick business buildings in the heart of Washington, D. C., one of them five stories high, were deliberately set on fire recently. While most of the city slept, and more than 150 firemen with high-powered apparatus stood idly by, flames shot skyward, walls toppled and crashed amid showers of sparks.
Seventy-nine of the Ninety Known Chemical Elements Are Idle, and Industry Offers Riches to Whoever Can Put Them to Work
E. E. FREE
A COUNTRY where eight tenths of the workers were always looking for jobs would probably not be prosperous. Yet that is precisely the situation of the great modern empire of chemistry to which the world al ready owes so much. There are ninety known elements—the workmen upon whom the chemist must depend for everything he does.
Soundproof Freight Trains to Run Through Holes in City Skyscrapers
JOHN WALKER HARRINGTON
NEW YORK CITY is to move a railroad off its streets. It is going to rip up the freight tracks of the New York Central Railroad that now run along Eleventh Avenue, known as "Death Avenue," and turn them into an elevated line. Straight through the block between Tenth and Eleventh Avenues the new railroad will run, burrowing through skyscrapers, hotels, and great apartment houses.
A STILLNESS hung about the rig of the Drumwell National Oil Company. From Main and Broadway, you could just see the faint outline of the derrick, tapering above the scrub oaks on the hill, far to the north of town. In the other direction, and closer, a bristling forest of rigs marked the rich oil pool which had brought Drumwell into existence and fame.
Amazing Modern Photography Solves Problems of Science, Industry, and Athletics, and Even Settles Legal Disputes
THE MAGIC EYE
IN A California court the other day, Capt. W. B. Sellner, State Fish and Game Commissioner, accused a man of trespassing and dumping garbage on his property. Vigorously the other protested his innocence. The court was puzzled. "One moment, Your Honor," said Capt. Sellner. "I can show you first-hand evidence."
He Has Made Himself Master of the Earth, Yet in the Universe He is Merely a Speck
WILLIAM BRADLEY OTIS
SOME weeks ago astronomers announced that a star, Nova Pictoris, apparently had split in two. The spectacle, described recently in POPULAR SCIENCE MONTHLY, was offered as a remarkable new discovery. Yet the actual event had occurred sixty years before Christopher Columbus was born! It had taken all the time since for the fastest messenger known to man to bring us the news.
AT NINE in the morning, not long ago, a San Francisco business man hurried down the gangplank of a liner just docked in New York. He was racing home from abroad to the bedside of a close relative, critically ill; a New York friend, notified by cable, had arranged his passage across the continent.
More Comfortable and Convenient, Certainly, But This Article Weighs the Problem as It Affects Your Purse
JOHN E. LODGE
IS THE added comfort and convenience of an oil burner worth the price? That question today confronts every prospective home owner. The answer, of course, depends on the value you put on the advantages of oil heating, and other factors that must be considered in contrasting oil with other fuels.
Secrets About the Selection and Use of Materials That Will Save You Money When You Build Your Home
JOHN R. McMAHON
"WHAT advice would you give a greenhorn on building a house?” "That’s a fine question!” snorted Uncle Ed Warner. “In what way, if you don't mind telling?” “Every which way. It’s like asking what advice a landlubber needs to become a navigator.
Improper Insulation the Cause of Poor Refrigeration, Our Tests Show
R. D. MORRILL
How much did you pay for your icebox? That question is mighty important because it involves both your health and your pocketbook. Although the United States uses far more iceboxes than any other nation in the world, investigations conducted by the Popular Science Institute of Standards have developed the alarming fact that most of these iceboxes are practically worthless for preserving purposes.
Amazingly Complete Systems With Tiny Locomotives Using Their Own Power Used to Teach Transportation Methods
L. G. POPE
TINY steam railroad locomotives that burn real coal and yet are no longer than your foot—miniature Pullman, baggage, and freight cars perfect in every detail— tracks, signal towers, switches, and other railroad equipment exactly like their full-sized prototypes are being produced by the patient skill of model makers in all parts of the world.
1. When, by whom, and where was the first flight accomplished in a heavier than air machine with power? 2. How were the early airplanes made to take off? 3. What department of the U. S. Government is charged with regulation of interstate air traffic?
An Intimate Study of the Great Explorer at Home — How He Plans an Expedition—Why He Is Going to the South Pole
"HE IS still sleeping," the maid told me when I came down to breakfast at eight o'clock. I was spending a whole twenty-four hours with Commander Richard E. Byrd at his home in Boston to see exactly what such a man does when he is not flying over some Pole or on some other exciting adventure, and the girl's words seemed to indicate that this was a lazy man.
Higher Values—Better Tone, Selectivity, and Volume—Lighted Dials—Dynamic Speakers
RADIO today presents a strikingly novel situation. Tremendous improvements have been made in the last year—more, perhaps, than in any recent year—and yet these improvements have all been accomplished without the aid of any basically new invention or discovery.
Solder That Needs No Iron—Noises Tell What's Wrong—Long Loudspeaker Cords—Problems of Changes in Tuning Solved
FOR amateur radio experimenting the electric soldering iron is ideal, but there are times when to use one is almost an impossibility. Soldering a lead to the antenna while you are up on the roof, for instance, or making a connection between wires of a home telegraph line quite a distance from the nearest electric light socket, cannot conveniently be done with an electric iron.
WHILE there are many connections in a radio receiving circuit that should be kept as short as possible, there are practically no limits on the length of a loudspeaker cord. This means that you can run an extension cord to any part of the house with no appreciable falling off in volume.
A DOCTOR with a listening instrument called a stethoscope can tell you what is the matter with your heart. Similarly, you should learn how to tell what is wrong with your radio equipment by listening to the sounds from the loudspeaker. The doctor sometimes makes an erroneous diagnosis.
IN MOST cases where the tuning of any given station suddenly changes you will find that the station actually has shifted its wave length, and you can be positive that this is the case if other stations come in at the points on the tuning control where you normally find them.
CONTRARY to the usual belief, the first sign of an exhausted power tube is not weak signals. Decreasing filament emission caused by many hours of use shows first in distortion when the volume control is turned too far. On weak signals, however, an old and practically exhausted power tube may give just as audible signals as a brand-new tube.
THE watt is the unit used to measure the rate at which electric power is consumed, and the watt-hour to measure the power used within a definite time. A current of one ampere at a pressure of one volt is one watt, and if the current flows for one hour one watt-hour of power has been consumed. In any circuit, you can determine the power flowing in watts by multiplying the rate in amperes by the pressure in volts.
Institute of Standards Tests Reveal Its Shortcomings and Show How to Experiment in Newest Method of Communication
ALFRED P. LANE
TELEVISION! A dozen times a day I'm asked to tell just when we will have television. And by television my friends mean a system whereby they can turn a knob as they do on their radio sets and see swiftly moving events, football games, yacht races, and so on recorded on a screen hung on the wall.
Cash Awards of $50,000 Go to Ingenious Employees for New Ways to Increase Efficiency and Devices That Reduce Costs
NORMAN C. McLOUD
BOOM! A wisp of blue smoke rises from the distant barge that lies at anchor in the river. An amphibian plane, poised on a rail above its deck, scoots forward, reaches the end, and skims into the air. Here is the powder type of catapult that the U. S. Navy has just announced it will place on every ship that carries an airplane.
Amelia Earhart Proves Value in Ocean Flight of Multiple-Engined Seaplane
"THE flight of the Friendship is intended to point the road toward the seaplane instead of the land plane as a means of flying across oceans, and multiple-engined planes instead of single-engined. It will help toward more comfortable flying; when women demand planes not only comfortable, but luxurious, men will build them."
Rome-Brazil Nonstop Flight Sets New Air Distance Mark; Plane Refuels 5,000 Feet up to Seek Endurance Record; Soundproof Cabins and Most Gigantic Motor Are Announced
BLAZING a 4,400-mile trail from Rome across Africa and the South Atlantic to Brazil, the Italian flyers Capt. Arturo Ferrarin and Major Carlo P. Delprete have just accomplished the longest nonstop flight in history. Their hop, ending on the Brazilian coast near Natal, eclipsed by 500 miles the record distance flight of Chamberlin and Levine from New York to Eisleben, Germany, made last year.
FOR a while it looked as if the fifty-three-and-a-half-hour mark set not long ago by George W. Haldeman and Eddie Stinson had clinched for America the world’s airplane endurance record. But it was not long to stand. Two Italians, Capt. Arturo Ferrarin and Major Carlo P. Delprete, whose latest ocean exploit is described above, flew fifty-eight and a half hours to a new record.
THE U. S. Bureau of Standards is seeking to make flying less of a strain on the eardrums. So far the best success has been obtained, according to Dr. J. H. Dellinger, Bureau physicist, by use of cabins with four-inch soundproof walls, faced with thin aluminum sheets, lined first with a veneer of wood and then stuffed with “dry-zero”—a lightweight cottonlike substance which is grown on South American trees.
SAID to be the largest type of aero engine now in use, and differing from all others in design, a new Curtiss air-cooled motor recently tested in a standard two-passenger observation plane develops 600 horsepower from its twelve cylinders, set in two rows of six.
GERMANY leads the world today in commercial aviation, with the United States so close a second that it is likely to take the lead in another year. France, Italy, and Great Britain trail in the order named. That is the recent conclusion of the U. S. Department of Commerce, based on Germany’s record of 5,713,200 miles flown last year and this country’s estimated 5,700,000.
This powerful machine, capable of landing on or taking off from either land or water, was built in the American Navy Yard at Philadelphia. It is shown on a catapult stand, ready for flight. Intended for service with the carrier Langley, it is now being tested at San Diego.
This 16-passenger monoplane with three 450-horsepower motors and exhaust pipes to carry the fumes beyond the cabin is named Hermann Koehl in honor of the Bremen’s famous pilot. It is one of the most luxurious planes of the Luft Hansa (Air League)—a merger of several early German air transport companies.
This folding plane is being used at Curtiss Field, N. Y., to demonstrate the operation of Handley-Page slotted wings, described in detail in this magazine last February. They are said to prevent spins and crashes.
Something went wrong when Don Juan de la Cierva recently flew his famous auto-giro, a plane with “windmill” wings which can rise and descend in restricted space. The flyer survived the 30-foot fall, which occurred at an English air pageant, but the machine was damaged.
WEAPONS and inventions of modern warfare have been brought into action recently in two decisive victories on land and sea over destructive pests, age-old enemies of man. After years of experimenting, Uncle Sam’s Chemical Warfare Service has at last developed a successful defense against ship borers, the submarine destroyers which undermine wharves and which, it is said, have destroyed more wooden ships than all the naval battles in history.
THE health of the world is improving, and the gain is most marked in America and Europe. Such is the encouraging word of Dr. Hugh S. Cumming, Surgeon General of the United States, after attending the 1928 meeting of the Health Organization of the League of Nations at Geneva.
WHENEVER Marconi sails on one of his cruises in the yacht Elettra, the world looks for some advance in wireless. It was not disappointed when, returning recently to London after his latest voyage, he announced that he was working out an improved method of beam transmission which will widen the range of world communication.
A WORKMAN at a cutting machine was disturbed over a quarrel with his wife. In a moment of distraction he forgot the knives and a serious accident resulted. Another man, operating a huge press, was worrying over a mortgage on his home. Failure, for an instant, to attend to his job nearly cost him his life.
HOW long can you lie on the beach without being painfully sunburned? Many a bather has experimented, to his sorrow, to find that his skin is surprisingly sensitive to the penetrating ultra-violet rays of sunlight. But now Dr. Robert C. Burt, of Pasadena, Calif., has invented a new instrument which, in a few minutes indoors, will tell just how easily you sunburn—without the chance of blistered shoulders and sleepless nights.
Prof. Bordier, University of Lyons, France, is seen here demonstrating his device that applies to the nose tiny plates which send high-frequency current into the inner tissues, relieving the congestion-and killing the germs that are the cause of the cold.
How You Can Construct, Without Straining Your Pocketbook, the Popular Ultramodern Pieces
MODERNISTIC furniture is so stimulating as to take one's breath away. It is at once severe and angular, crystalline and scintillating. You may not like it at first, but it grows upon you and often ends in fascinating you. Folding screens decorated in the modernistic manner offer the amateur craftsman an especially easy and natural way in which to introduce the new mode into his own home.
A Few Scraps of Wood, a Knife, and a Shady Seat Outdoors Are All You Need to Make This Privateer
E. ARMITAGE McCANN
BECAUSE the weather is hot and we wish to be outdoors, it does not necessarily follow that we must discontinue our ship model making. We can follow the example of the old-time sailorman who gathered some scraps of deck planking and sat on the fore hatch and whittled a model of his ship.
How to Coax More Miles an Hour from a Light Motor Boat—Fuel, Lubrication, and Ignition—Hints on Choosing Both Hull and Power Plant
Outboard Motor Speed Table
SPEED—how to get more speed—is the topic of the day with the outboard motor boat owner. In the past few years the speed possibilities of these little craft have increased so rapidly that today it is not unusual to hear thirty miles an hour talked of, whereas a short time ago the utmost expected was ten or twelve.
Sometimes It Protects You and Sometimes It Doesn’t, And This Article Tells Why—How to Study Your Policy
THE day was boiling hot. A sympathetic farmer, driving his truck home from town, stopped to pick up a weary "hitch hiker." A few minutes later the truck collided with another machine and the hiker was injured. He sued for $10,000 damages. “I’m insured,” said the farmer, unworried.
New U. S. Submarine, Largest in World, Is Also the Safest
THE V-4 largest submarine in the world and latest to be commissioned for service in the U. S. Navy, will not lack for safety devices. Its great size permits many that would have overburdened smaller craft, the Navy announces, and the giant boasts 106 provisions for the safety of its crew.
A FIVE-PASSENGER motorcycle that can outdistance a motor car is the latest addition to the Berlin police department. The German invention carries besides its crew a powerful searchlight, emergency rescue apparatus, and a spare tire.
HOW did radium, most costly mineral in the world, and vanadium, valuable ingredient of modern alloy steel, happen to become concentrated in the sandstone rocks of southwestern states? Under what temperatures and pressures is gold deposited in quartz?
NOW a new use has been found for cadmium, brother metal to zinc and, combined with other chemicals, the chief ingredient of brilliant yellow paints with which we are familiar. It has recently been utilized in the making of special new solders that fuse at unusually low temperatures.
SOLID perfumes to replace liquid scents have appeared in this country following their recent introduction in Paris. Intended for travelers in particular, they are in paste form and are applied to hair, neck, or clothing. Ordinarily paste obtained by boiling flowers in fat is distilled to make perfume, but the new scents are simply the undistilled paste.
FIRE engines are keeping pace with the mechanical progress of this fast-moving world, as the remarkable photograph at the right shows. The latest engine, recently demonstrated in London, is a combination pump, fire escape, monitor, and searchlight, with amplified telephonic communication with the ground.
HOUSE to house delivery is expedited by a new truck which the driver may operate from the running board as well as from the driver's seat, says a Virginia dairy company that has installed it. The truck, its makers say, is so noiseless that it won't wake sleeping customers.
AT A distance of twenty miles or more, when the weather is fair, you can tell the time by a remarkable new electric clock that has recently been installed in Baltimore. It faithfully indicates the hour by red and white flashes from sixteen huge electric lamps.
MORE than twice the power of an ordinary engine with less than half the fuel consumption is the claim made for a new type of motorcycle engine introduced by an Australian inventor. The engine develops twelve horsepower, and in a demonstration before the High Commissioner of Australia, shown above with the inventor, is reported to have made close to 14,200 revolutions a minute.
ENOUGH ice cream to make twenty billion ice cream cones is America's consumption each year, a recent estimate states. In twelve mouths' time, we eat 324,000,000 gallons, according to figures placed before the International Association of Ice Cream Manufacturers at Atlantic City, N. J.
NEARLY seven hundred million horsepower—enough, if converted into man-power, to furnish every man, woman, and child in the United States with sixty servants—is the total capacity of all the power generating equipment installed in this country, according to the latest exact figures, for 1923, just released by the U. S. Department of the Interior.
ONE man standing before two huge control boards, one of which is seen at the left, supervises the operation of thousands of automobiles that pass daily through the twin tubes of the Holland vehicular tunnel under the Hudson River between New York City and Jersey City, N. J. Red, yellow, and green lights, flashing on the boards, signal the location of traffic tie-ups or accidents, and the operator summons emergency trucks or diverts the flow of traffic by throwing designated switches.
Gigantic English-Made Bell Coming to American Church
A FEW weeks ago the largest assembly of bell-ringers England has ever seen gathered at Croydon to hear the booming of the biggest bell ever forged in that country—a giant that will be shipped to America to find its home in the tower of a New York City church.
CAVALRY charges of the future may be thunderous and clanking assaults of platoons of mechanical steeds, as the armies of the world continue to perfect new types of caterpillar tanks for modern warfare. The British Army has begun eliminating horses by equipping cavalry units with baby tanks, and recent tests proved their worth.
A NEW idea in money-making—the collection of rent from airplanes passing overhead—recently occurred to Samuel Schwarz, owner of a house at Zebden, Germany, who interpreted literally an old law reading, "The rights of a property owner extend to the space above and the ground beneath his property."
TWO thousand trains a day whiz along the Southern Railway's tracks in England. This entire stream of traffic is to be controlled by a tremendous signal box at London Bridge. Miniature levers that operate the intricate signal system border the control box as far as the eye can see.
ALREADY New York is wondering where it will dock the world's biggest liner, the Oceanic, whose keel has just been laid at Belfast, Ireland. The great ship's 1,000-foot length will require a longer pier than any yet in existence. It will be finished by 1932.
AMONG things to worry about comes the occasional warning, on one hand, of the danger of "race suicide"; on the other, of the peril of an over-populated earth with not enough food to go around. Which should cause the most concern? Results of the latest investigations seem to answer: “Neither.”
DID Methuselah, of Biblical fame, really live to an age of 969 years —or was that the life of the clan he founded, that bore his name? The latter is the sensible interpretation, R. P. Field, of Philadelphia, recently told the American Philosophical Society. The chronicled birth, apparently of a son, to many a patriarch, Mr. Field declares, was not that of a person but of a new tribe that had split off from the father’s clan.
Giant Zeppelin for Sale; Will Go to Highest Bidder
DO YOU know of anyone who would like a nice, brand-new dirigible for Christmas? If you do, now is your golden opportunity. For the Zeppelin Construction Company of Germany announces that it will be only too glad to sell to the highest bidder the mighty airship LZ-127, now being rushed to completion.
LIKE an airplane in appearance is the novel sailboat seen below that can see-saw its way directly against the wind and just as easily can turn and ride with it. Before a group of eminent German engineers, its inventor, Friedrich Budig, of Berlin-Grunau, demonstrated how his queer craft could capture the wind’s direct force to tilt the air vanes first to one side and then to the other, driving a propeller that pushes the boat forward.
NOW England, too, is to have its flivver, according to reports. Recent secret tests of a new automobile of only seven horsepower—only a third of that of most American small cars—are said to have shown it capable of amazing speed and pick-up.
Novel Use for Typewriter in Making Flexible Rulers
IF A ruler marked in tenths of an inch is not available, when such dimensions must be measured, it may easily be contrived with a typewriter. Many type-writing machines make ten spaces to the inch; and a paper rule is obtained by typing a row of periods, alternated with commas every tenth space to mark inches.
RIGHT down to the water's edge backs a new lifeboat-launching auto invented in Germany. Its body tilts, and as the boat slides into the water a curved guide points it upward to prevent its being swamped. With the speedy carrier, which holds the craft on steel rails, a boat may be launched in a fraction of the time it takes to drag it by muscle power down a beach, and with less effort.
ASBESTOS suits are the latest style for firemen in Glendale, Calif., where the mayor and fire chief of the city recently gave them the hair-raising test seen at the right. Almost surrounded by flame in a small wooden shack deliberately set on fire, they fried an egg in the conflagration which nearly enveloped them.
ADDITIONAL details concerning the speedy new fire boats put into service at Portland, Ore., and described in the June POPULAR SCIENCE MONTHLY, have been supplied by A. D. Merrill, naval architect who designed the boats. The operating mechanism of each boat, including pumping units, propelling units and generators, can be controlled by one man from the pilot house.
IVORY is given a silverlike finish that actually is composed of tiny silver grains by placing it in a dilute silver nitrate solution, and then in a solution of common salt until it turns deep yellow. Next the ivory is dipped in water. and exposed in the sun until it blackens.
SERVING alternately as a portable double stall for huntsmen's horses and a conveyance for their touring car, an ingeniously adapted automobile van makes hunting more comfortable for English sportsmen. The horses are brought to the meet by van, while the men go by car.
THAT a huge parachute can land an entire airplane safely in case of motor failure was demonstrated again the other day at Tracy, Calif., in the latest of two years' experiments described from time to time in POPULAR SCIENCE MONTHLY. At an altitude of 2,200 feet, pilot E. J. McKeon shut off his plane's motor and went into a dive.
AN ENGLISH physicist says he has discovered the existence of a second "radio roof." Fifty or sixty miles above the earth's surface experts believe there is a layer of electrified atoms of air gases underneath which the radio waves travel great distances, and through which they cannot penetrate.
TO DEMONSTRATE his plan for flood control, Carroll Livingston Riker, mechanical engineer, built this remarkable sixty-five-foot model of the Mississippi Valley and installed it in the basement of the Capitol at Washington, D. C. Rivers, valleys, and levees are shown in perspective.
FROM time to time, POPULAR SCIENCE MONTHLY has told of the experiments of Howard T. Barnes, Professor of Physics in McGill University, Montreal, in breaking up ice jams by the use of thermit, the remarkable mixture of iron rust and powdered aluminum which, when ignited, produces terrific heat.
HUGE sums that railroads pay to destroy weeds along their right-of-ways may now be avoided by the invention of a new mower on wheels, towed by a motor handcar. Pivoted cutter bars cut a six-foot swath on each side of the track while the car rolls along at the dogtrot pace of four miles an hour.
WHAT was your most embarrassing moment? Wasn't it the time you started to introduce a friend to a man you had met a moment before—only to discover that you had forgotten the latter's name? Dr. Donald A. Laird, psychologist of Colgate University, has been studying ways to avoid this predicament.
IT ISN'T any trick at all to tune-in your favorite broadcasting station with the new receiving set pictured at the left. All you need do is press a button; automatically the dials leap to the correct positions and in comes music. Previously the receiver has been tuned to the station in the ordinary way and an adjustment tightened.
CAMOUFLAGE—which helped win the war—is helping catch mice, according to a recent report of the United States Biological Survey at Washington. The latest traps are designed to deceive the most wary rodent. One, built for mice that rob corncribs, looks like a hollowed-out corncob and has its death-dealing spring hidden in the center.
A LOUDSPEAKER for your telephone now is available in the form of the portable amplifying unit pictured at the right. It is readily attached to any type of instrument. Although originally intended to make telephone conversations easier for persons with defective hearing, it is also useful in a noisy office where listening is difficult.
A TOY with a valuable educational purpose is a housebuilding set for youngsters that has recently been placed on the market by a member of the National Committee on Wood Utilization. To the boy who plays with it, the set, with its tiny sills, beams, joists, and rafters, some of which must be cut to size, affords limitless fun in constructing lifelike dwellings in miniature.
THOUSANDS of rare birds will occupy the world's largest aviary, nearing completion on Catalina Island, Calif. It is soon to be open for public exhibition and scientific research. Already live specimens from plains, mountains, and tropical jungles are arriving daily.
RECENT tests show that the crowing of a rooster, the ringing of a church bell, and, under some conditions, the shout of a man penetrate almost a mile into the upper air. A cricket’s chirp carries up 2,500 feet, and the croak of a frog can be heard at an altitude of 3,000 feet.
HOW an earthquake telegraphs a message of destruction far in advance of human communication is disclosed by official records of the quake that recently wrecked the city of Philippopolis, Bulgaria. At the instant the quake struck, seismographs all over the United States penned their record.
JUST arrived in the United States is Joseph Darbel, French inventor, seen above with his ingenious new camera to take pictures in natural colors. In reality it takes three pictures simultaneously, through a single lens. Each records one of the three primary colors from which all tints of a scene are blended.
COLDS and bronchitis are the most prevalent ailments in America. Influenza and grippe come second. These statements come from Dr. Hugh S. Cumming, Surgeon General of the U. S. Public Health Service, after two years’ investigation. Respiratory infections cause more lost time in industry than any other group of diseases.
SOMETHING new in "beam radio" is a remarkable reflector for radio waves being tried out at a Nauen, Germany, transmitting station, in experiments in "pointing" a radio beam at one particular receiving station. This method conserves power and makes secret communication possible without the necessity of a code.
REMARKABLE inconsistencies in auto lighting laws among various states are revealed in a chart recently compiled by engineers of the National Lamp Works, Cleveland, O., which is seeking a uniform lighting code. The distance a car’s headlights must be visible varies from seventy-five feet, in Delaware, to two hundred feet in seventeen other states.
ALTHOUGH his new explosive "radiumatomite" is many times more powerful than TNT or nitroglycerin, Capt. H. R. Zimmer, of Los Angeles, handles it as if it were so much flour. A former Army officer, he developed the remarkable invention in his outdoor laboratory.
ONE of these days a new element may be added to our list of known ones, all but bringing it to completion. A mysterious, unidentified radioactive element, much more potent than uranium, radium's parent, exists on earth and releases quantities of energy, Prof. Walther Nernst, of the University of Berlin, recently told the Franklin Institute at Philadelphia.
ON HER recent voyage from San Pedro, Calif., to Honolulu, 2,228 nautical miles, the U. S. Navy's new aircraft carrier Lexington shattered all records, doing 700 miles the first twenty-four hours, 742 miles the second, and 786 miles in the remaining twenty-four hours and thirty-four minutes.
LAST year cancer caused a loss of $800,000,000! That is approximately what 300,000 workmen would lose if they were out of jobs for a year. This estimate comes from Dr. Louis I. Dublin, statistician of the Metropolitan Life Insurance Company.
FLOATING concrete islands capable of being navigated from place to place like ships, by means of their own propellers, are the latest French idea in ocean landing fields for planes. The novel "seaports," of which a model was recently exhibited by the Chamber of Commerce of France, would be seaworthy enough, it is claimed, to take up stations as halfway stops in transocean flights.
Inventor Makes Wheels Spin the Right Way in Movies
MAKING whirling automobile or carriage wheels look natural on the screen—a twenty-year puzzle of the movies—has just been solved. Because movie cameras could not keep pace with the rapid flashing of the spokes, wheels often appeared to revolve backward.
TO ADVERTISE his wares, a German merchant of perfumery and toilet waters sprays with perfume all passers-by free of charge, and even scents the air in front of his shop. From the top window of his store a little hose, seen in the picture above, shoots forth a shower of the merchant’s different brands of perfumery, and the window shopper can sniff the air and make his choice from the sample before he goes in to buy.
BULLFROG hunters in the marshes of Louisiana have been making such big catches of late that there are more frogs now than there are people who enjoy the delicacy of their fried hind quarters. As a result of this overproduction, the market price of the croakers recently dropped to a low level—about half the price of dressed chicken.
SUNLIGHT reflected into his studio by a huge movable reflector is used by a California photographer in making enlargements. The reflector, shown in the picture below, is made of aluminum-painted metal over a wooden frame. It is tilted to proper positions by ropes operated from the inside of the studio, and the rays are directed through a window, on the inside shelf of which the enlarging camera rests.
GOLF balls that figuratively call "Yoo hoo, here I am!" when they get lost in the "rough" are promised by a New York inventor. They depend on the player's senses of smell, hearing, and sight to help him discover them. One plan is to coat the balls with the fireworks composition commonly called “spit devil.”
POPULAR SCIENCE MONTHLY is glad to answer, whenever possible, readers' questions on any subject within its field, and to supply names and addresses of makers of devices described in the magazine. A stamped and self-addressed envelope should be inclosed.
UNCLE SAM has turned to the bootlegger's equipment in experiments, under direction of the Prohibition Bureau, to develop a nonpoisonous denaturant for alcohol. The business of the Government's still, pictured at the right, is to do the same thing that the bootlegger does— take the poison out of denatured alcohol, but at the same time to make it disagreeable to the taste.
SEVENTY bricks in a wheelbarrow, pushed at a brisk pace, are easier to wheel than fifty bricks in the same barrow trundled at a slow walk. The British Industrial Fatigue Research Board has come to this conclusion after tests. Large rubber bags were attached to the backs of men wheeling varying weights at different speeds.
IF THE engine of your car unexpectedly overheats while you are driving, the trouble may be due to any one of a number of causes. The first thing, of course, is to make sure there is enough oil in the crank case and enough water in the radiator. If so, then look for a slipping or broken fan belt.
ACCORDING to the Federal Bureau of Education, American college students number more than those in all the other countries combined. They total about 1,000,000; those in the rest of the world, 950,000. In schools of all kinds, 29,000,000 students are enrolled in the United States.
TO TEST your knowledge, see how many of these questions you can answer. Correct answers are on page 136. 1. Where was the first oil well in the United States? 2. Where are the largest stones ever used? 3. Where is the Great Barrier Reef? 4. What people wear socks divided for the big toe?
PROF. H. L. SHANTZ, of the University of Illinois, recently told the National Academy of Sciences that the earth is capable of supporting 8,000,000,000 people, if all the land is fully utilized. This would be nearly five times the present population of the world.
TRAVEL by motor bus has reached such proportions in the East that fifty-four interurban lines now operate into New York City, and the bus companies are erecting terminals similar to railroad stations to accommodate the traffic. These terminals are complete, with waiting rooms, restaurants, rest rooms, telephone and telegraph service, barber shops, and beauty shops.
THE Borgias and other notorious poisoners of history were reputed to have mixed finely powdered glass in food and drinks which they offered their victims. Recently, however, Dr. Roche Lynch demonstrated to the Medico-Legal Society of London that this supposedly murderous material usually passes through the human digestive system without causing death or even doing serious damage.
AT ROCKY POINT, N. Y., there has just been erected what is said to be the most efficient type of beam radio transmitter yet installed. Outstanding features are its simplicity and the efficiency with which it directs a pencil of radio waves toward distant receiving stations, resulting in economy of power and high-speed transmission.
A BUILDING so big that the plumbing and wiring will be measured by "mileage" rather than by footage is being constructed in Boston. It will cost $21,000,000, cover 130,000 feet of ground space, and be the largest building in the world. It will surpass in floor area such famous structures as the General Motors Building in Detroit and the Graybar, Telephone, and Equitable Life buildings in New York.
FIVE years ago, almost to the month, Rear-Admiral William A. Moffet, Chief of the Navy Bureau of Aeronautics, wrote a remarkable prophecy for POPULAR SCIENCE MONTHLY. He predicted giant air liners "of 5,000,000 cubic feet capacity, equal in size to the steamship Leviathan."
Gus Gives a Know-It-All Driver a Few Hints Concerning His Automobile That Are Worth Anybody's Reading
"ISN'T it funny," observed Joe Clark, "that just as soon as a fellow gets to know a little about automobiles, right away he thinks he knows it all!" Gus Wilson, his partner, working on a motor outside of their Model Garage, grunted. “Know-it-alls give me a pain,” he growled.
Does the Rain Drown Your Motor? Is the Window Cracked? Do Insects Clog Your Radiator? Here’s How Others Fixed It
GENERALLY when your motor refuses to start after a heavy rain it is because water has leaked through the hinge joining the two sections of the hood. Fig. 1 shows how a gutter of sheet iron or, preferably, brass can be constructed to carry the water harmlessly away.
BROKEN or cracked glass windows on an automobile are dangerous as well as unsightly. If the glass has broken in a clean crack, without shattering at any point, it can be repaired so that the crack will hardly be visible, as shown in Fig. 2. Obtain a good grade of transparent glass or celluloid cement and a sheet of celluloid.
TO END the nuisance of insects in your radiator when the pests swarm in summer, keep them out with close-mesh window screening as shown in Fig. 4. After cutting to size, the screen is held in place at several points by wires threaded through the holes in the radiator.
WHEN the bolt and nut are greasy and the light is not particularly good, it is extremely difficult to find a cotter-pin hole. A time-saving and ingenious idea is to file an indicator mark across the end of the bolt exactly in line with the cotter-pin hole, as shown in Fig. 3.
IF YOUR car lacks a device to carry off fumes from the crank case and prevent their entering the body of the machine, you can fit such a device as shown in Fig. 5. A half-inch pipe is brazed or soldered into the side of the oil filler pipe and the end of it brought down below the motor.
THIS month's prize for the most valuable idea for motorists is awarded to Clarence Clevenger, of Santa Clara, Calif. His contribution, a time-saving kink for locating cotter-pin holes, is shown in Fig. 3 and described elsewhere on this page.
IF YOU wish to give your neighborhood, school, or model club a real thrill, build a giant airplane model like that illustrated. Only by seeing the enormous model soar away in flight can one realize the sensation it creates among the spectators.
Small Shop Methods for Grinding Plain and Spiral Mills—A Universal Tooth-Rest—Clearance Angles
HECTOR J. CHAMBERLAND
IN SHARPENING plain or spiral milling cutters, side mills, end mills, angular cutters, counterbores, and reamers, the toolmaker or machinist has to observe two essential requirements: First, he must know the proper clearance angle; and secondly, he has to provide a good rest for the teeth.
AN INEXPENSIVE way of rigging up a lathe for turning a large radius is shown in the illustration below. While of a temporary nature, it is free from the troubles which usually accompany makeshifts, and enables the work to be turned out rapidly and accurately.
If you work to close limits, once a week you should have your micrometer tested at every one-tenth reading. Don’t always blame the milling cutter—or even yourself—if it runs out; half of the time the trouble is in a sprung arbor. Worn screw slotters, ground cylindrically and to the required angle, make very good slitting disks.
IN NO other way can you turn your wood turning to better advantage than in making legs for decorative tables. Rarely has a home too many small tables; there is always room for a graceful occasional table like that illustrated in Fig. 1 or a book-trough end table such as is shown in Fig. 8.
WITH odds and ends of boards, a few tools, and a moderate degree of that desirable trait "gumption," any boy can build toy "chutes" which will give him and the "gang" hours upon hours of pleasure. Nail the tracks to the crosspieces, place the resulting ladderlike frame upon a box or a built-up support, and cut the bottom of the rails to fit the walk.
THIS simply made Spanish-Colonial wood box for the fireplace has the advantage of being a carrier as well as a receptacle. It saves bringing dusty logs from the basement in one's arms. The wood for the box should be chosen for its decorative grain.
HAMMER and nails are in common use in every household. Yet driving nails, the commonest of all mechanical operations, is not often done in such a way as to get the full holding power of the nails. A few plain facts about nails and their uses would, if they were observed, decrease the difficulties encountered and save much effort and subsequent disappointment in the failure of joints.
IN BUILDING a racing car at home, it became necessary to heat some heavy iron bars. The cost of a forge was prohibitive for this one job, so a forge was improvised on the spot. An old heating stove bowl, which was badly cracked, was found in the scrap pile.
Unique Triple Stand Combined with an Electric Lamp
C. A. K
THE combination electric light and triple stand illustrated in Fig. 1 is a distinctly novel piece of furniture for the amateur woodworker who wishes to build something that cannot be duplicated in a furniture store. The trays may be used for smokers' articles, books and papers, or sewing materials.
ITS great power and extreme lightness give this toy hydroplane surprising speed. It is literally a mosquito among water craft. Use 3/16-in. white cork pine or similar light, soft wood for all parts except the rear propeller support, which is whittled from ¾-in.
IF YOUR home workshop is used by boys who may be careless about fire, or if you have any other reason for installing a fire alarm system, you can do so at a trifling expense. All you need is a circuit of the type used for house door bells and one or more sensitive fire indicators so placed that they will be affected by any excessive heat.
NOT having a separate room to use when spraying homemade furniture and school projects constructed by boys, I found a good shield could be made from a large discarded window shade. I hung the shade on the wall about six feet from the floor so that it could be pulled down behind the painting table.
OUR blueprints can be obtained for 25 cents a sheet. In some cases there are two or three sheets to one subject. The blueprints are complete in themselves, but if you wish the corresponding back issue of the magazine in which the project was described in detail, it can be had for 25 cents additional so long as copies are available.
CHEMISTRY furnishes a cheap and simple means for testing materials. While it is true that the old-fashioned buyer of such raw materials as paints and varnishes, bulk foods, steels and brasses, fuels and cements was satisfied to lay out his money "by guess and by gosh," the hard-boiled modern business man trusts no label but, before spending a nickel, sends a sample from each delivery to a commercial chemist.
Urges Everett Eames, Who Explains How to Combat Many Common Defects—Leaks under Windows and Cracks
W. W. S
IT IS easier to build a new house than to keep it looking new. Time and the elements soon produce a subtle change, which advertises its increasing age only too plainly. Fire excepted, water in the form of rain or melted snow or ice is the most relentless destroying agent.
IN A great many houses today there is at least one dresser finished in golden oak, which was once universally popular but is now entirely out of style. Perhaps no more profitable opportunity exists for improving home furnishings than by refinishing one of these old-fashioned dressers, together with a couple of chairs and whatever bed is in the room, into a modern bedroom suite.
WHAT can be done at almost no cost at all by an ingenious amateur mechanic is demonstrated by the accompanying illustration of a jig saw built by Dr. L. St. John Hely, of Richmond, Calif. Wood from packing cases served to make the framework except the legs, which cost 30 cents, and the base, which is a piece of 2 by 12 in.
A GOOD serviceable holder for stain and paint brushes can be fashioned in a few minutes from a piece of metal weatherstrip of the type illustrated. Drill ⅛in. holes not more than 6 in. apart and fasten any desired length of the strip to the bench or wall with ¾-in. No. 10 round-headed screws.
CLEANING out the inside of a pipe, hollow casting, or any deep hole or receptacle is often difficult to do satisfactorily. The usual expedient is to tie a rag to a stick or piece of wire, with the result that either the rag pulls off or else fails to reach the bottom corners.
By DOING a Little Amateur Bricklaying, YOU CAN Build an Indoor Incinerator
It Reduces the Cellar Fire Hazard and Saves Much Trouble in Burning Paper, Sweepings, and Trash
DISPOSING of paper, sweepings, and other combustible rubbish, which constantly accumulates in every home, is an end less task. Worse still, their storage while awaiting disposal creates a serious fire hazard. To burn the rubbish in the furnace quickly chokes the pipes, ruins the fire in winter, and heats the house in summer.
IMITATION inlaid inserts or marquetry ornaments can be made from shavings in a fraction of the time required to cut and apply real inlays. With a very sharp finely set plane, prepare a few wide, thin shavings of the wood or woods to be used in the “inlay.”
HOW a strong yet slender kitchen stool can be made in an hour or so with the simplest of tools is shown below. Two pieces of wood (from packing boxes) are used for the seat, the grain of one piece crossing that of the other for strength. The upper piece is round or octagonal; the under one is square and to it are nailed the legs, which are made from 1 by 4 in.
IN AUSTRALIA, a few weeks ago, was written an epic of the progress of life on earth, from crawling worms to flying men. At about the time Captain Kingsford-Smith and his comrades were alighting at Brisbane after a record ocean flight across the Pacific, there was announced the discovery, in Australian mountains, of the fossilized remains of the oldest known inhabitants of the earth, who lived some 600,000,000 years ago.
PROF. G. W. RITCHEY, noted American astronomer, predicts that within the next eight years the world will know whether there are cities and men in the planet Mars. Professor Ritchey supervised the design and construction of the 100-inch reflector for Mount Wilson observatory, largest in the world.
HOW many tons of coal will your bin hold? Measure its length, breadth and height in feet; multiply these together for the contents in cubic feet. Divide the resulting number by thirty-five, the average number of cubic feet in a ton of coal, and you have the capacity in tons.
THE list of amazing new jobs for X-rays, as given in the July and August issues of POPULAR SCIENCE MONTHLY, continues to grow. Recently Dr. F. Holweck, noted French X-ray expert, applied the destroying power of the rays to calculate exactly how much it takes to kill a single disease germ.
IF YOU jump from a plane, the greatest speed your body will attain is between 100 and 120 miles an hour no matter how far you fall. That is the surprising discovery of the U. S. Navy's Bureau of Aeronautics, based on night-experiments with flare-lighted dummies at Wright Field, Dayton, O. These dummies were hurled from high-flying airplanes.
INFORMATION of an aviation equipment department, with branches from coast to coast, is contemplated by the Automotive Equipment Association, according to its president, Arthur C. Storz. Such a step would signalize the entry of automobile makers as a whole into airplane servicing; and, Storz declares, many individual automobile manufacturers and jobbers are already supplying near-by airports with aviation equipment.
MOTOR bus and airplane facilities are combined in the latest rapid transit project, similar to the proposed transcontinental air-rail transport. It is planned to operate fast airplane passenger planes in conjunction with existing motor bus routes between Detroit, Kansas City, and Salt Lake City.
FEW people stop to realize that the ground under their feet is full of flowing streams and rivulets. Yet, according to the latest estimates of Dr. Chester A. Reeds, of the American Museum of Natural History, the water under the ground is equal in volume to one third of all in the oceans!
SOME weeks ago a giant meteor flashed like a bombshell across the skies above Georgia and South Carolina. Startled inhabitants reported a severe accompanying "earthquake." Houses trembled, window panes crashed. Can meteors cause earthquakes?
WHEN a number of sacks must be filled, holding them open with one hand becomes exasperatingly clumsy. An easier way is to drive four curved nails around the inner rim of an open barrel, and suspend each sack within the barrel. When filled it is easily removed to make room for another.