How $680 a Year Increased Craig Wright's Estate From $12,000 to $42,000
JEFF MARLEY was scared. With thoroughly justified fear he viewed the immediate financial prospects of himself and his family. And well he might. No one could exactly accuse Marley of being improvident. He had worked hard —too hard for the good of his health.
THE Booklets listed below will help every family in laying out a financial plan. They will be sent on request. The House Behind the Bonds reminds the investor of the importance, not only of studying the investment, but of checking up the banker who offers it.
THE equivalent of years of everyday wear is given in a few minutes to tools undergoing tests in the laboratory of the Popu1ar Science Institute. Some of these machines seem almost human in their movements and tell accurately facts that years of usage would only partially disclose.
I SHOULD like to call your attention to an article in your publication for January, 1930, pages 17 and 129. This article refers to “street noises,” and dismisses the most serious street noise with some remarks that are not correct. I refer to the noise of riveting machines, in steel buildings.
Within the year the sport of gliding has advanced to a point where it is safe, easy to learn, and useful. More than a thousand American men and women, girls and boys, now are following it with enthusiasm. Other thousands are preparing to try their wings. Here is the first of a series of articles explaining all the facts about this thrilling outdoor sport which is training the aviators of the future.
EDWIN W. TEALE
MORE than a thousand Americans are flying without motors. Thirty-two gliding clubs, scattered from coast to coast, are in operation and fifty more are being formed. In one state, Ohio, there are nine clubs, all affiliated with the National Glider Association.
A SHEER eighty-foot cliff of steel rising straight into the air. Small white faces peering down from the rim. A pygmy figure, wearing an aviator’s helmet as protection from the biting wind, standing on the bridge a hundred feet above the water.
How the Strongest Cables in the World Support the Load of Huge Bridges, Carry Aerial Railway Cars, and Serve the Many Needs of Engineers
"THE wire's got to come down— every strand of it." The speaker was one of a group of engineers for the new Ambassador Bridge, that was to link Detroit to the border cities of Ontario, Canada. They stood at an anchorage, examining one of the huge cables that supported the 1,850-foot main span, longest in the world.
A SHORT, shy man stepped from a gangplank the other day on his second visit to America—Dr. Claude Dornier, premier German aircraft builder. He explained his mission simply. “The aviation of the future is in big flying boats. I think America is the logical place for their development.”
MOST of the superstitions of the past still survive in some degree. Especially is this true in the field of psychology, one of the youngest of the experimental sciences. The majority of people probably believe in telepathy or “mind-reading,” and yet this belief is lacking in experimental proof.
On this and succeeding pages are presented the latest achievements of inventors including important devices and processes, together with useful methods for making and doing the old things in a better way
THE stock ticker is to tick no more. New high speed machines that whir instead are to be installed in brokers’ offices in New York, Chicago, San Francisco, and 350 other cities in the United States and Canada. They will record by telegraph news of transactions on the New York Stock Exchange, replacing old machines found too slow for modern trading.
FOGHORNS will not only give warning, but will tell a fog bound captain just how far he is from shore, if a new radio and sound wave device now being tested at Cumbrae Lighthouse, near Glasgow, Scotland, comes into general use. At the instant the foghorn blows at the lighthouse, an automatic radio transmitter begins vocally to count off “one,” “two,” “three,” and so on, at intervals of five seconds, the time required for sound to carry one mile.
UNUSUALLY powerful electric signal lamps that flash their colored beams for miles and are visible through fog and bad weather by day or night are being employed to supplement the familiar semaphore signals along the main lines and in the yards of American railways.
EVEN more of a surprise to the engineering world than the "pocket battleship” Ersatz Preussen which created a sensation last year is the Leipzig, a new water dragon of the German fleet capable of holding a speed of thirty-two knots or thirty-six miles an hour.
"XETAL," a new safety glass said to be proof against fire, splintering, or discoloring has been patented by an English firm and subjected to rigorous laboratory tests. When service revolver bullets were fired at the glass at distances of ten and twenty-five yards, it is reported, the glass was pulverized to a depth of only one thirty-second of an inch.
TURNING on its own water supply, and handing out a wax paper packet of powdered soap and a towel, a new “automat,” recently displayed at an exhibition of automatic machines in Berlin, Germany, furnishes all the materials necessary for a thorough wash. All the customer need do to obtain service is place two ten-pfennig coins, the equivalent of approximately five cents in American money, in a slot and pull a handle.
LITHIUM, a metal so light that it easily floats on water, is now to be available in tons instead of pounds, as heretofore. Through a new quantity production method developed by Dr. H. M. Partridge, New York University chemist, it will cost at wholesale rates only $15 a pound.
RAILROAD cars are the latest things to be equipped with windows of “health glass” which transmit the beneficial ultra-violet rays of the sun. Travelers to the south of England, bound for Cornwall and neighboring sunny winter resorts, now have available a special express service equipped with the “sun bath” cars.
DESIGNED for a wide variety of uses about the house and yard, a new combination ladder invented in California can be made to serve as a short, straight ladder, an extension ladder, a stepladder, or one that can be adjusted to rest on the steps of a stairway.
While the new front-wheel-drive car is being introduced in America, a British manufacturer has gone to the opposite extreme in the unusual model pictured above. Retaining the rear drive, its engine and radiator are placed in a trunklike compartment back of the chassis, between the rear wheels.
Accelerator and foot brake are combined in one pedal in the new electric brake control shown below. Toe pressure on the pedal works the accelerator; heel pressure works the brake. The latter closes a circuit and actuates an electromagnetically driven solenoid (in the circle) which, in turn, moves the cams that apply the brake.
The motion picture camera and screen are playing an increasingly important part in the training of medical students. In the clinic of the University of Berlin, Germany, has been installed the special movie camera pictured above. Focused on the operating table, it makes a film record of every step in the surgeon’s work.
Instead of the movies, the elaborate apparatus shown at the left is used in the American Hospital in Paris, France, to reproduce scenes of an operation for students. Suspended above the operating table, it works on much the same principle as the familiar magic lantern which projects photographs or post cards on the screen.
High-Speed Photographs Make Whirring Wings Stand Still
"ARRESTED motion" photographs at extremely high speeds may open a new world for nature study in the future. A bee’s wings, it has been computed, beat at a rate between 2,000 and 3,000 times a second. But Joseph A. Speed, A.R.P S., of London, has caught a bee in motion with a shutter so quick that not only were the wings shown stationary in the resulting photo, but even minute details and markings of the wings were revealed.
IN THEIR efforts to design higher skyscrapers architects are limited by an enormous dead load of flooring. To lessen this unnecessary burden on the building’s supporting structure, a new type of floor panel construction has been invented by steel engineers.
WHEN garage floors become covered with dust and spotted with oil, a sprinkling of sawdust or sand saturated with kerosene assists in the cleaning. It prevents clouds of dust from rising during the sweeping and the kerosene removes most of the small oil spots.
A LIGHT combination desk and seat, which can be adjusted to suit any child from four to ten years of age, has been devised by a California inventor, who claims that the equipment weighs at least ten pounds less than the present standard school desk, is just as serviceable, and costs half as much.
YELLOW pine lumber has entered the field of tunnel engineering with the building of the new water conduit from the River Rouge to the Ford Motor Company Plant in Detroit, Mich. From the bottom of a seventy-foot shaft twenty hydraulic jacks are driving an enormous steel shield horizontally through the earth to make a circular tunnel nineteen feet in diameter.
THE problem of snow removal in large cities may be solved by chemistry after this year. Chemical methods of breaking up snow and ice along the gutters have been tried out this winter, particularly in the Boroughs of Manhattan and Brooklyn in New York City.
Passengers on crack trains of the Dominion Atlantic Railway in Nova Scotia can sit on observation platforms without being choked by swirling dust. A new dust catcher consists of a rectangular frame of iron pipe covered with a screen of canvas and attached horizontally to the end of the observation car a foot below the floor level.
By changing blades, this new adjustable saw can be used to cut stone, iron, steel, or fiber, as well as wood. It also will cut at any desired angle, or make circular grooves. The circular blade is attached to an arm which moves on ball bearings.
Sixty-five feet undersea, the crew of the Italian submarine S-17, in recent tests near Spezia, Italy, entered a newly invented safety tube and shot to the surface in six minutes. At sixteen feet depth, others of the crew escaped wearing only bathing suits.
All the shaver need do to keep a keen edge on this novel razor, the inventor claims, is to shake it once in a while; for it combines in one unit a blade, a hone, and a strop. The shaking is said to move the blade edge over a sharpening surface to which a special chemical abrasive has been applied.
TO REDUCE the increasing number of fatalities from automobile-train collisions, the German government recently introduced special railway signal lights for automobile drivers at grade crossings. White and red are the colors used, corresponding to the green and red lights ordinarily used for railroad signals.
UNDERGROUND steam heating plants may be the next item on the list of agricultural implements. Heating the soil has been found by an English chemist, Dr. W. F. Bewley, Director of the Experimental and Research Station at Cheshunt, to destroy pests and diseases and to increase soil fertility.
"AIR CLINICS" for nervous and rundown patients are suggested by C. L. Julliot, French lawyer. With the reported approval of the medical faculties of France, he proposes airplane rides as a tonic for the nerves. Every hospital might maintain an airplane or two for the use of its patients.
A HANDY tool for slashing open a cardboard or fiber carton with a straight line cut, so that the container may be used again, is the recent product of a New York City manufacturer. Simple and speedy in operation, it can be used to open either small packages in the home or large shipping boxes in stores and other business houses.
THE first "ship-to-shore" telephone service by radio was opened on a recent eastbound voyage of the steamship Leviathan. Seated at his desk in the offices of the American Telephone and Telegraph Company on Broadway, New York City, Walter S. Gifford, President, took up the phone and asked for “the United States Liner Leviathan, somewhere at sea.”
ABOVE the twenty-six-mile stretch of the Grand Trunk Railway running from Detroit to Pontiac, Mich., a four-way automobile toll road mounted on steel pillars will be built. This is said to be the first instance in which the air rights of a railway have been used for automobile traffic speedway purposes in the United States.
The touch of a finger tip on a lever just below the steering wheel operates a new auto gear-shifting device which works by vacuum and does away with the usual shift lever. It is the invention of J. H. Newmark, automotive engineer of New York City.
An amateur talking motion picture outfit in combination with a radio receiver is the latest thing in home entertainment. Produced commercially, the talkie apparatus comprises a motion picture projector and phonograph. A 16-millimeter picture film is carefully synchronized in movement with the phonograph disk on which the voice is recorded, the timing being accomplished by an ingenious electrical hook-up.
Resembling a giant crossbow, a new life-line catapult has been devised by Alberto Santos-Dumont,the Brazilian aviation pioneer who made the first airplane flight in Europe in 1906. He is pictured below with his invention placed in firing position.
More certain identification of criminals is the purpose of this new camera designed to standardize photographs by automatic control of lighting, exposure, and focus. Strong, diffused light assures clear pictures and avoids distortion of the face.
The idea of making a motor car manufacture its own gasoline is embodied in this apparatus devised by D. E. Fowler, of El Paso, Tex., (above) for the use of crude oil as motor fuel. It consists of a cylinder attached to the engine and acting as a portable still for producing gasoline by the “cracking” process.
A CAMERA attachment for a shotgun is the latest invention to enable a sportsman to test his aim as well as the accuracy of the weapon itself. At the touch of the trigger the gun fires a “camera-cartridge” as well as the usual charge of birdshot.
A "REFRIGERATED" telephone receiver, designed to take the discomfort out of lengthy conversations in hot weather, has been invented by an English engineer. Made of special material, it is said to contain a new kind of freezing mixture which becomes perceptible only when the warmth of the ear is applied to the casing.
A NOVEL convenience for the traveling man is a "knockdown" shaving brush with removable bristles and carrying shaving cream and powder within its handle. In the cap that screws over the butt of the handle fits a little round case containing powder and puff.
AN ELECTRIC typewriter designed to print words and phrases in addition to single letters is the invention of Clyde C. Baiston, of New York City, who claims it will write a business letter five to twenty-five times faster than the usual machine.
A NUT that can't be shaken loose, yet comes off easily with the turn of a wrench, has been invented by a French mathematician, H. L. Dardelet, and is now manufactured in this country. It is used with a special bolt. The harder one tries to twist it, the harder it grips.
"SMOOTH sailing" is the motto of an expedition of scientific and business men which recently left the Tebo Yacht Basin in Brooklyn, N. Y., for the Galapagos Islands. The new vibrationless yacht, Olive K, owned by Charles F. Kettering, head of the General Motors Research Laboratory in Detroit, is the ship of adventure which the expeditionists are trusting to keep them from seasickness and jiggling bunks.
Above is a working model of a new nonstop moving sidewalk system demonstrated by its inventor, Herman E. Taylor, traffic supervisor of Detroit street railways. It comprises two worm-driven belt conveyors, one carrying seats and moving at a constant speed of 20 to 25 miles an hour, the other starting at ¾ mile an hour and accelerating to speed of the other in 9 seconds.
Instead of water or liquid chemicals, Germany’s newest type of fire engine pumps through the hose lines a harmless carbonic acid powder which is said to smother flames without damage to fixtures and goods. The powder pumping machine is pictured in the oval above.
This motorized “lumber buggy” supersedes the horse-drawn two-wheel cart in Pacific Coast mills to speed the transportation of lumber about the mill yards or to shipping docks. Straddling a pile of lumber, it lifts it bodily at the touch of a lever and carries it away at a speed of 15 miles an hour.
Joseph Graziano, New York shoemaker, has devised a carburetor which, he claims, permits use of fuel oil instead of gasoline in motor cars. It includes special spraying and heating chambers for vaporizing the heavy oil. Photograph shows the inventor and his son installing the device.
A NOVEL "compensator" for the reduction of recoil peculiar to high powered rifles and shotguns has been introduced to sportsmen by a Connecticut manufacturer. It is claimed that it will reduce recoil fifty percent. Fitting on the front of the gun muzzle, it seems to get around the established physical law that action and reaction are equal, at least so far as the effect on the gunner’s shoulder is concerned.
THE family ice man, vanishing before the spread of mechanical refrigeration, may come back—with a load of “dry ice” on his shoulder. But his calls will be less frequent, according to Walter S. Johnson, one of the pioneers in developing the new refrigerant, who made the prophecy before the American Society of Refrigerating Engineers recently.
THE possibility of making diamonds from burnt toast is suggested by Dr. S. Paramasivan, a brilliant physicist of Calcutta, India. Diamonds are carbon atoms packed extremely tight. The only difference between diamond carbon and lead pencil carbon is that the atoms in the latter are packed very loosely, like the crumbs of a sponge cake.
THE hack work of laboratory workers in biology and physiology may be considerably lightened by the use of a time-saving invention recently perfected by a banker-scientist of Tuxedo Park, N. Y., A. L. Loomis, and described at a meeting of the National Academy of Sciences.
ON THE banks of the Volga River by the town of Stalingrad, Russia, a new factory has been established for the manufacture of syrup from the pink pulp of watermelons. This new product, known as “Nardek,” will have its uses split in half ; the better grades of the syrup will be used in cooking or confectionery, and the poorer grades utilized in the manufacture of alcohol.
FROM wood pulp to artificial silk—a pictorial story of progressive steps in the so-called viscose process of manufacturing rayon. Eighty-five percent of the world’s rayon now is made by this method, which was perfected in 1900 by two British chemists.
The Veteran Commander of Navy Dirigibles Tells of His Experiences in Piloting the Los Angeles
Lieut. Commander CHARLES E. ROSENDAHL
WE WERE just back from Panama, one March night, and the Los Angeles was being hauled down to the ground in its second landing attempt. The men on the ropes and those holding the handrails on the outside of the cabins were walking the ship across the field to the hangar.
TWENTY-TWO of America's foremost scientists and inventors have consented to serve as members of the Committee of Award which will administer POPULAR SCIENCE MONTHLY’S annual award of $10,000 for the year’s outstanding achievement in science, the creation of which was announced in the February issue.
IF ALL the rubber consumed in the United States last year in the manufacture of tires were made into a single tire of average automobile tread, it would have a diameter of more than forty miles. Lying on the ground, it would encircle 1,400 square miles of territory, far more than is contained in the state of Rhode Island.
Developments in engineering, exploration, and discovery, and news of the world’s progress in science are recorded on these pages. Here are included the interesting features previously presented in “Back of the Month’s News.”
REMINDERS of the days of '49 may still be found today in the dogged prospectors who still haunt the streams of northern California panning for gold. They always hope that they will find the mother lode. The modem methods of prospecting are electrical.
WEATHER forecasts from almost inaccessible regions will now be practical, it is said, by the use of a new traveling weather bureau recently sent to the Sierra Madre Mountains for the United States Forestry Service. The equipment, housed in a motor truck, consists of an elaborate radio receiving and transmitting equipment plus all the usual instruments necessary to measure wind velocity, humidity, and barometric pressure.
A BATTERY of giant X-ray tubes immersed in a tank of oil and operated at the electric pressure of 1,600,000 volts produced man-made rays like those of radium in a recent demonstration at Washington, D. C. The experiment, performed by the Carnegie Institution, was a step forward in attempts of physicists to break down the atom itself.
WHEN a stick of dynamite goes off, the wave of explosion travels along the cartridge at four miles per second, one of the fastest chemical “reaction” speeds known. Experts at the laboratories of the United States Bureau of Mines at Bruceton, Pa., have been measuring this speed by a clever mechanism called the mettegang (German for “go-between”) recorder.
A POPULAR impression among motorists has been that automobile engines run better in muggy weather. That the opposite is true is now revealed by recent tests on six-cylinder engines, announced Daniel P. Brooks of the Bureau of Standards of the United States Department of Commerce.
THE "tomapotato," a new plant demanding a new name, which produces potatoes at its roots below the ground and tomatoes on its stalk above the earth, has been developed after twenty years of experiment by Oscar Soderholm, foreman of a florist’s greenhouses at Worcester, Mass.
THROUGH a process developed in the research laboratory of the United States Department of Agriculture, fruit that would take many days or weeks to ripen on the trees may be ripened in storage in only a few hours by treating it with ethylene gas.
THE world's largest submarine has been launched at Cherbourg, France. The Surcouf, 400 feet of steel naval defense, has complete armor protection for all vital parts exposed when running at the surface. This makes her really an armored cruiser, as she can withstand the shells of light quick-firing guns and can return fire.
SOME day the earth may have rings like Saturn's. This possibility was suggested recently by Dr. Harlow Shapley, director of the Harvard College Observatory. Saturn’s rings are held to be composed of myriads of tiny moons. The earth’s rings, according to Dr. Shapley, would be formed from fragments of the earth’s moon.
A PARTIALLY noiseless pneumatic drill for tearing up city streets and similar excavation work has been tested in London and found to be successful. It is said to reduce the noise of drilling by more than sixty percent. Two methods of noise prevention are used.
The unusual triple-span bridge pictured under construction at the left is an attempt of Japanese engineers to relieve traffic congestion across a junction of waterways at Kyobashi, the industrial center of Tokio.
That theater auditoriums soon will be patterned after ancient Greek amphitheaters is the prediction of a German architect, who has embodied his ideas in the model shown above. The domed roof has been skeletonized to show the interior.
If caught in the rain, Berlin pedestrians now can deposit the equivalent of fifteen cents in a vending machine and pull out an umbrella. The folding emergency umbrella comprises a hood of oiled paper and a handle of wood.
New Camera Photographs Eyes to Find Secrets of Vision
SECRETS of vision that lie within the retina of the human eye on which, day after day, millions of pictures are photographed successively, are now being investigated by means of a new camera perfected at the famous Zeiss optical works at Jena, Germany.
GIANT electric batteries, consuming coke and air and yielding electricity cheaply enough to revolutionize house heating and other branches of practical engineering, are suggested as possibilities by Professor M. deKay Thompson of the Massachusetts Institute of Technology.
PERHAPS plants have nervous systems and hereafter may be treated by neurologists. In experiments with the large cells of the water plant Nitella, Dr. W. J. V. Osterhout, of the Rockefeller Institute, has found evidence of nerve currents similar to those of animal muscle and nerve.
A GERM that looks under the microscope like a string of pearls is probably the thing that gives people the “flu,” according to Dr. Isadore S. Falk, University of Chicago bacteriologist. He reports that he has isolated the long-sought cause of influenza, and that experiments are already under way to develop vaccines and antitoxins to prevent and cure the disease.
TEST your knowledge with these questions, chosen from hundreds asked by our readers. Answers appear on page 155. 2. Which is more powerful— an electric locomotive or a steam locomotive? 3. How would you compute the horsepower that can be developed by a waterfall?
PICTURES now can be taken on plates of solid metal, instead of film. A way to develop pictures made on gold and other metals is the recent discovery of Dr. P. H. Carr, Cornell University. The new method of photography without light is not intended for taking snapshots of the baby, or the suburban home.
GRAIN alcohol from natural gas is the latest feat of manufacturing chemists. It has been developed by the Union Carbide Company by “cracking” the gas into ethylene (a new anesthetic of great possibilities) and converting ethylene into ethyl (grain) alcohol by a new method of combining ethylene with water.
NOW comes the "automatic chemist" —a device that relieves the chemist of one of the most tedious parts of making an analysis. As recently demonstrated in New York City, the automaton measures either the acidity or alkalinity of a solution, or the amount of certain ingredients in it.
IN A recent report to the American Medical Association comparing the diets and diseases of 501 selected patients, Dr. Lovell Langstroth, of San Francisco, finds that the ordinary “business man’s” or “society woman’s” diseases are due not to fast living but to bad food.
IN THE past artists have coveted the daylight from the northern sky for matching their colors, believing it the best possible. But A. H. Taylor, physicist of the National Lamp Works at Cleveland, Ohio, recently told the Illuminating Engineering Society that northern skylight varies in intensity from day to day and even from hour to hour.
For several months a truck carrying delicate instruments to measure the intensity of noises has been roaming New York streets gathering evidence in the city’s antinoise campaign (P. S. M., Jan. ’30, p. 17). Health officials are seen here making tests with the instruments, which give visible and audible records.
To aid movie film editors to synchronize pictures and sounds for the talkies, a new machine called “moviola” has been devised. Into it the editor feeds the picture film (left) and the sound film (right). By listening to the sounds and watching the picture he superimposes one record upon the other (center).
To speed the growth of plants in a test garden at Stockholm, Sweden, electric heat is applied to the soil. Beneath the beds are laid lines of resistance wires about a foot apart, as shown at the right. These are sheathed with brick and then covered with a layer of soil a few inches in thickness.
By subjecting ordinary table sugar to enormous heat and pressure in the laboratory. Prof. J. M. Hershey, of McPherson College, Kansas, claims to have produced diamonds the size of a grain of sand. Larger artificial gems are possible, he says.
This huge dredging machine recently advanced along the Landwehr Canal, Berlin, Germany, clearing the waterway of an accumulation of debris and sediment. The buckets, rising from the bottom, dumped their load into a tank; the water drained out, leaving the sediment.
Around the Air Circuit for a 5,000-Mile Record—New Amphibians for Forty Passengers—Other Flying Progress
Safety Contest Winner
Adding 75 Feet to R-101
Automobile Engine Drives Plane
New Curved Radio Beam
Mail Pilot Flies Million Miles
ALL distance records for airplane flight apparently have fallen, recently, with the trip of Dieudonne Costes. French aviator, and his companion, Paul Codos, over a closed circuit in France. Although the mark actually attained has not been checked officially at this writing, preliminary estimates place it close to 5,015 miles.
Workmen Labor Night and Day to Save California Cities from a Water Famine
WHEN nine cities in the East Bay region of California were faced with a water famine, engineers working day and night completed one of the world’s mightiest dams a year and a half ahead of schedule. Unusual high-speed methods erected this 358-foot-high structure, the Pardee Dam on the Mokelumne River, in world’s record time.
Science Traces the Shepherd Dog, Wolfhound, Spaniel, Bulldog, and All the Others, Back to a Common Ancestor Which Lived Millions of Years Ago, and Discovers Interesting Facts to Explain Why a Great Dane Differs from a Pekinese
SEVENTY-NINE breeds of dogs, among them rare and little-known varieties, will constitute soon the greatest dog show on earth, at the Peabody Museum of Natural History in New Haven, Conn. It will be a show without a bark, for the novel collection is not of living dogs.
Mass Production on Farms Now Made Practicable by Harvesting Unripe Grain
JOHN E. LODGE
MACHINE methods applied to agriculture are growing three crops of grain a year where only one grew before. Already well past the experimental stage, a device that dries green crops artificially by coal fires and powerful ventilating fans is being used successfully on five large farms in the United States.
What a Veteran Pilot Has Learned from Encounters with Storm and Fog During Sixteen Years of Flying
WHEN I think of flying weather at its worst, I think of a 9,000-foot plunge through darkness filled with ripping bullets of ice that I once experienced. I was up with a photographer in a Bulgarian army plane during the war. We were ordered to take pictures of British movements behind the Saloniki lines.
TOILING along the snow-covered crags of the upper Alps, in antlike single file, hardy Italian troopers recently engaged in a spectacular mountain-scaling maneuver. Nearly a mile of marching men, tied together with long ropes as a precaution against falling over cliffs, wound up the slopes of the Bernina peak on the border of Italy and Switzerland.
BEAUTIFUL deep-blue gems of zircon, hitherto known only in brown, greenish, or yellow colors, recently appeared in American markets and puzzled jewelers. Now the mystery may be explained with the observation of Dr. George F. Kunz, New York jewel expert, that they may owe their color to the little known and only lately-discovered element hafnium.
WHEN the ancient Mayas of Central America prayed for rain they got a quick reply. Their prayer was answered the same day it was offered, or very shortly after. This was not divine intervention, but a scientific coincidence of the seasons, according to Zelia Nuttall, famous expert on Central American history who recently addressed the Royal Anthropological Institute in London.
FORTY-THREE white rats recently vied with twenty-three college students in threading a maze at the laboratory of R. W. Husband, psychologist of the University of Illinois, who is bent on comparing the intelligence of rats with that of men.
MEAKING industrial buildings attractive has of recent years been one of the minor accomplishments of the engineering world; but nowhere, perhaps, have the results been so striking as in a unique building erected in Suffolk, England.
PALEOBOTANY, the science of flower fossils, has lately brought to light some unusual specimens, autumn leaves millions of years old imprinted on rock with the original colors retained. Dr. Ralph W. Chaney, paleobotanist of the Carnegie Institution in Washington, reports the finding of these curiosities in newly discovered fossil leaf beds of Wheeler County, central Oregon.
THE evolution of the underground piping system of a large city could be partly traced in the Bloomsbury district of London, England, when replacement work was undertaken, following a series of gas main explosions, and a number of old wooden pipes used in bygone days for the transmission of the city’s water and gas supplies was unearthed.
IN A few years the American bald eagle will be seen only on coins and the coat of arms of the United States unless drastic action is taken to save these birds from extinction, according to W. Dewitt Miller, ornithologist of the American Museum of Natural History, New York City.
NEARLY 300 years before the automobile appeared, traffic congestion was already a problem. In London, a retired naval officer, named Bailey, had bought carriages previously used only by aristocrats, dressed the drivers in livery, and had begun carrying passengers.
FOUR hundred individual 1enses mounted on a wooden rack are being designed to provide a reflecting surface of 100 square feet in an unusual experiment in telescope construction by C. W. Woodworth, professor of entomology at the University of California.
LURKING on the sea bed of the Great Barrier Reef, off Queensland, Australia, and so shaped and colored as to be almost indistinguishable from its surroundings of horseshoe clams, knobby-corals, and algae-covered stones, a fine specimen of the “stonefish,” called the world’s most repulsive fish, was discovered recently by G. P. Whitley and W. Boardman, two scientists of the Australian Museum.
A GERM colony which took up lodging in the shoulder of a British Tommy when he was wounded in battle eleven years ago was recently found to be still alive, according to the report of the operation which brought it to light, made by Dr. R. J. V. Pulvertaft of St. Thomas’ Hospital, London.
IN CAVES in southwestern France water crystals have been found which are estimated to date back to prehistoric times. They were discovered in the “Cave of the Sister of the Falls” by archeologists who were exploring for traces of primitive men, and proved to be perfect water crystals, probably the largest ever found.
A 57,000-horsepower water wheel, said to be the biggest ever built in the United States, is nearing completion at a Newport News, Va., shipbuilding yard. It is America’s bid to capture supremacy in the building of the great rotors, of which the world’s largest are those of 70,000 horsepower at Niagara.
PLAYING cards made of aluminum, with colored faces and backs, are the newest thing for a game of bridge. They look and feel like ordinary cards, except that they are a little heavier. On the beach or porch, the cards will not blow away, and they are handy for the camper, too.
THE historic woods of Fontainebleau, France, have gained added fame from their ability to produce giant specimens of fungus. In the recent exposition of mushrooms and like growths in the Muséum d’Histoire Naturelle, Paris, France, appeared one such specimen, illustrated in the photograph.
MORE exciting than a Wild West rodeo, and more perilous, is a wild elephant hunt in the hill forests of India, as pictured here in close-range photographs. Decoyed by tame elephants, the angry, trumpeting beasts are rounded up in herds, roped with enormous “lassos,” and captured alive.
RECENTLY the Daniel Guggenheim Safe Aircraft Contest came to a close. Any hope of its being a "contest" in any accepted sense of the word faded long before the end. An airplane automatically received the $100,000 award because it was the only one successfully to complete the eighteen required tests for safeness.
Experiments on the POPULAR SCIENCE MONTHLY Distance Getter show ways to get rid of cross modulation and improve selectivity of the receiver
ALFRED P. LANE
ENGINEERS hailed the appearance of A. C. type screen grid tubes with enthusiasm. The new tubes, they said, would make radio receivers easier to design and more efficient in operation. Their predictions have largely been fulfilled. For any given degree of sensitiveness it is easier and simpler to employ a circuit using screen grid tubes.
How to Adapt a Battery Set to Use 227 Heater Tubes; Plugging in the Headphones for Distance Reception
Use Headphones for "DX"
A B C’s of Radio
THE simplest method of rewiring an old battery set for A. C. operation is to use type 227 heater A. C. tubes in all sockets except that of the last audio stage, in which a type 171A power tube should be used. In POPULAR SCIENCE MONTHLY for February, 1929, on page 65, was outlined a method of rewiring a battery set, using 226, 227, and 171A tubes.
ALTHOUGH natural static is a radio nuisance for which no remedy has been found, man-made static, including all types of interference produced by electrical machinery, can, in many cases, be eliminated. Whenever extraneous noises interfere with radio reception the first step, therefore, is to determine to which type of interference they belong. The test is simple.
And Demonstrates His Point by Using Them to Pull the Car of an Unbelieving Motorist Out of the Mud
"I'VE been expecting a call like this from Morrison," Gus Wilson grumbled to his partner, Joe Clark, as they stopped the Model Garage service car beside an expensive new coach job that was stuck in the mud. “Where are your chains, Mr. Morrison? ” asked Gus, as he noticed the position of the stuck car.
WHEN POPULAR SCIENCE MONTHLY requested me to write a "how-to" article on building a small outboard boat for fishing and family use, I had no idea that before I was through with the job Seascoot would actually come into being. I expected to furnish the design, write a few words of advice on building the boat, and let it go at that.
Trestle Gate Table of True Colonial Design Serves as Object Lesson in Studying Spindle Turning Operations
WILLIAM W. KLENKE
GENERALLY speaking, wood turning lathes can be divided into two main dasses: direct motor-driven and those run with a belt. There is something to be said for and against each type, and the use of either of them is mainly a matter of personal preference.
Fine Points in Handling the Copper Bit Skillfully and Making Neat, Strong Joints—Fluxes for Various Metals
PROBABLY no tool used by the amateur craftsman is so little understood as the useful soldering copper, or soldering iron as it is sometimes called. For fine work, there is really no substitute for this tool. It has the advantage of applying the heat and the solder within a limited space and does not warp small pieces of thin metal as does the blowtorch.
IF THE car is kept in an unheated garage, a motor cover arranged as shown in Fig. 1 will promote easy starting in many cases. Of course it will do no good if the car is not used for days at a time, but if it is operated daily, enough heat will remain in the motor overnight to make it start easier.
WHILE the trail-worthiness of the Diamond Tally-Ho—that famous old stagecoach which years ago swayed on leather springs and rocked back and forth in rhythmic fashion over the rough road from San Diego to the small town of Julian in California—depended on the sturdy construction of the carriage, all the romance of gold mining days was symbolized in its brilliant vermilion body.
WIRE, through proper handling and intelligent choice of form, can be used to solve many difficult, problems in the shop. Its physical characteristics make it a suitable material for use as tension, torsion, and compression members, and for many other purposes which to most of us are less evident.
MAKE use of every safety device provided in the shop. Always lift a file on the return stroke; dragging it dulls the teeth and scratches the work. When melting babbitt, stir in some rosin or oil. This will purify and thin the material and all foreign matter will come to the top.
BALANCE and weight make the burr cutter shown an efficient accessory for the small machine shop. The cutter is easily machined, being circular in shape and having a tapered body and round knurled handle. The cutting edge is formed at a 45degree angle and is hardened back far enough to allow ample stock for repeated sharpenings.
A SIMPLE and efficient taper boring attachment for use on small lathes can be made with the expenditure of little time and money. The attachment shown consists of a 1 in. diameter steel bar having a ¼-in. keyway cut along its entire length. A cutter head with a key fastened to its inner surface slides on this bar.
HOME craftsmen who are wood turning enthusiasts will find the small upholstered bench illustrated an exceptionally attractive spindle turning project. The construction is not too difficult for the beginner and yet has enough character and grace to make it a worth while problem for the expert.
Doctor Finds Home Workshop Restful After Day’s Work
RECREATION in the form of mental and physical play is a necessity in every man's life. No one should be without some hobby, some means of taking his mind from the everyday worries of a commercial or professional career. The home workshop enthusiast finds mental relaxation in his little shop, tucked away in some corner of the house or hidden in attic or basement.
DURABILITY, together with the quality of being worked easily into shape, makes leath er an excellent medium for decorative craftwork. A box, such as the one shown, will practically never wear out; in fact, its attractiveness increases with age.
Easily Constructed Wall Vase Made of Hammered Pewter
PEWTER is an excellent metal for decorative metal work, being inexpensive, easy to handle, and attractive in appearance. Its advantages will be discovered in making a vase like that illustrated at the right, the construction of which is relatively simple and well within the capacity of a beginner in metal work.
A SIDE from its decorative value, the lighting fixture illustrated is both practical and easy to build. The bracket, or shelf, is made of ¾-in. white pine, finished in gold bronze, and gone over carefully with a blowtorch or similar flame to scorch it and produce an antique appearance.
BY USING a set of angle irons having 45-degree grooves cut in them as shown in the illustration, the grinding of round objects will become a simple matter. When high pieces are to be ground the angles supply a double surface for the pull of the magnetic chuck, and the danger of having the work come loose and break the wheel is eliminated.
CURVED and small concave surfaces can be readily sanded by using the small ball sander illustrated. Machine a section of hexagonal stock to the size desired and affix to its end a small wooden ball. This ball is then dipped in glue and fine sand or emery dust and allowed to dry.
WINDOWS and screen doors can be assembled strongly by the butt joint and dowel method illustrated. Making the joints in this way saves considerable time, especially if the mortise and tenon joints must be made by hand.
AN EXAMINATION of any group of pocketknives probably would reveal as many different kinds of edges as there are knives. Most of us sharpen knives by holding the blade at a rather large angle to the stone and moving the blade back and forth with a more or less careless rolling motion that eventually rounds off the edge and gives it a shape somewhat similar to the small end of a pear.
TO ASSIST you in your home workshop, POPULAR SCIENCE MONTHLY offers large blueprints containing working drawings of a number of well-tested projects. Each subject can be obtained for 25 cents with the exception of certain designs that require two or three sheets of blueprints and are accordingly 50 or 75 cents as noted below.
VEGETABLE racks for the pantry and kitchen take up little room and allow a quick choice of any of their contents. The rack illustrated is large enough for the average family and can be made from scrap pieces of lumber. The writer made the thirty-two ½ by 3 by 8¾ in. slats from lumber salvaged from lettuce crates.
WHITE spots such as those caused by hot dishes on a mahogany table top sometimes can be removed simply by rubbing them lightly with powdered pumice stone. The idea is to remove the discoloration but not cut right through the varnish, shellac, or lacquer.
CARBON-ZINC cells that wifi give two hours of steady service at a I voltage of between 1.2 and 1.5 and that will recuperate to full voltage in 24 hours can be made easily in the home laboratory for experimental work. They will light small flashlight bulbs and can be used for many electrical experiments.
PROBLEMS in planning and arranging a motorized workshop vary with the space available, the machines to be used, and the type of work to be done, but there are a few kinks that can well be incorporated in any shop, large or small.
ORDINARY faceplates,because of their large hubs and, center holes, often present difficulties where small pieces of work are to be attached to them with the aid of bolts. This is especially true if the bolts which hold the work are to be placed near the center portion.
PLANERS are sometimes idle for long periods of time, thus leaving the ways exposed to the dust and grit of the shop, which becomes ground in when the machine is started. One shop protects the planer ways by providing a board cover for each side.
GANG switches can be obtained in sets of two or three switches and in either three single-pole, one single-pole and one three way, or two single-pole and one three way sets. These units take up the same space as one ordinary switch and therefore are handy for installations where old switch boxes are to be used, since no new hole need be cut in the plaster.
Special Silk Thread Wrapping Adds to Strength and Resiliency of a Homemade Rod for Casting
ROBERT PAGE LINCOLN
SPIRAL winding or truss-winding a rod with silk threads is probably the most ingenious manner of rod winding open to the amateur rod maker. It method that not only strengthens the greatly but also gives it a graceful, resilient action. Solid wood tips so wound have double or triple the value of like tips wound straight across in the ordinary manner.
WHEN only a joint or two is loose in a piece of furniture, it is usually possible to spring the parts far enough apart to insert glue and then bind them together or clamp them until the glue has hardened. If possible scrape off the old glue before applying new glue.
OIL paintings that have been hanging for a number of years sometimes become dull and lifeless. Such paintings can be quickly brought back to their former clearness by cleaning and then brushing with a special picture varnish. In cleaning, care must be taken.
THOSE who have tried it know that while hard rubber can be ground to shape on an ordinary emery wheel, it is practically impossible to shape soft rubber in the same manner. This difficulty can be overcome by using an emery wheel having square teeth cut into its surface.
Homemade Pedestal Built Entirely of Standard Fittings and Two Auto Axles
C. A. HOWARD
PROBABLY few readers have ever associated gas pipe and astronomical research in the same channels of their minds. These have been associated, however, and out of this thought has grown an efficient and durable telescope mounting. The mounting illustrated was made the writer and is now in use on the grounds of his home in Dallas, Texas.
FEW dogs can boast of having a residence as fine as the one built by G. O. Lawrence, of Semaphore, Adelaide, South Australia, and pictured above. Figurátively speaking, the house has all the conveniences of a modern home. As Mr. Lawrence expresses it in his letter, “Our dog is a very happy one, and with a little patience we hope to train him to turn the light on for himself so that on dark nights there will be no danger of his tripping over the doorstep!”
FOR the amateur woodworker who wishes to build furniture of the newer trend, this combined radio and phonograph cabinet has the merits of novelty and utility. It affords ample room for most types of receiving sets as well as space for a phonograph and records.
WHILE little difficulty should be encountered in constructing the parts that go to make up the two block puzzles illustrated at the bottom of the page, the solutions are of a type to keep your friends guessing a long time. Below are given the solutions to the two puzzles of a similar character which appeared in P.S.M., Feb. ’30, p. 117.
ANY reader who has had some experience with concrete work will be interested in the unusual examples of cement construction shown. They are the work of D. H. Frew, of Lisbon, Ohio, an editor and publisher. The garage was made from concrete panels 1 in. thick and 8 ft. long, which were molded in sheet iron pans.
STORM water and seepage can be easily removed from cellar coors located below the sewage drain by the ingenious application of a steam boiler feed water injector. First, break through the flooring at the lowest point, place a 100-lb. white lead or similar can flush with the surface of the floor, and cement it securely in place.
SUCCESS in model airplane construction depends, as in all crafts, not only upon the skill of the worker but on the tools that he uses. The novice, especially, will find that a set of a few specific tools will simplify and improve his work. A sharp pocketknife and a block plane having a 1-in. blade are probably the most important parts of the plane builder’s tool kit.
CIHILDREN are less likely to forget their three-times-a-day duty and are encouraged along the lines of tidiness if they are provided with the attractive little toothbrush holder illustrated. The design can be cut from a ⅜ by 5 by 7⅜ in. piece of soft wood, since the figure is 7¼ in. high and 5 in. wide.
BLACK iron enamel of the best grade forms a very efficient cement for use in mending many small crocks or pieces of highly prized china. First, dry the piece of crockery or earthenware to be mended thoroughly. Apply the enamel to the crack with a thin piece of wood shaving, being careful to spread it on evenly all along the cracked edge.
BY INSTALLING a simple electric alarm of the type illustrated, you can efficiently protect a garage, chicken house, barn, or similar building against burglars. Even if the wires are cut by the thief the alarm rings. The system operates on a closed circuit which holds a relay open until the circuit is broken or a short circuit occurs, whereupon the alarm is sounded.
NEATNESS and cleanliness spell success in refinishing an automobile with a small motordriven spray gun. This is true in the preparatory work (P.S.M., Feb. ’30, p. 106), and even more so in the actual application of the priming coats and the finishing lacquer.
FOR the amateur artist who wishes to perform a novel stunt in home entertainment, "musical cartoons" are something new, amusing, and mystifying, yet may be performed without special talent or previous training. In fact, an hour or so spent in preparing the materials will insure a hit on any program.
HELIUM gas passes through nearly half a mile of copper tubing to be purified, in a mobile reclaiming plant developed for the Navy’s new airships under construction at Akron, O. The outfit can be towed behind a motor truck. Previously, gas-reclaiming plants were so heavy that they had to be mounted on railroad cars for transport.
FLAG stops for airplanes, like flag stations for railroad trains, have been added by a transcontinental air line, extending its scheduled service. Three such stops are at Vandalia, O.; St. Elmo, Ind.; and Terre Haute, Ind. At these points passengers may board planes by notifymg the company’s representative, and passing planes stop for them on signal.
In the files of our Information Department are thousands of questions asked by our readers, from which these monthly questions and answers are compiled. What particular field or fields of applied science would you like to have presented in this form in forthcoming issues?
LIVING matter created synthetically in a test tube is predicted as a future possibility by Dr. Paul R. Heyl, physicist of the United States Bureau of Standards. Recent advances in the ability of chemists to duplicate nature’s substances, he says, are bringing this hope nearer.
MANY are the stories of balls of fire that enter houses during lightning storms, are reported to roll or float about, and often at the end explode with a loud report and lingering smell described as “sulphurous.” Unfortunately such phenomena have a way of happening, if at all, when no scientist is around to observe them.
THE cost of stage scenery has been reduced from thousands of dollars to thousands of cents at the Grand Theatre in Geneva, Switzerland, by an ingenious method of substituting paper for wood and other more expensive compositions ordinarily used in the fabrication of scenery.