IN MANY American homes, people are asking, "How are future developments of the radiotelephone likely to affect us?" No one is in a position to. answer all the implications of this question. The possible expansion or retrenchment in the broadcasting of entertainment, the extent of lasting public demand for musical programs of the present type, the method by which, in the long run, these programs will be financed—all these matters hinge on unforeseeable contingencies.
Science Explains Cloudburst, Tornado, and Thunder Shower
The Storm Clouds
How Hail Forms
Why Thunder Storms Bring Hail
Size of Drops Limited
Eleven Drops in Cubic Foot
Storms Grow as They Advance
Whirling Air Creates Vacuum
WHO has stood fascinated by the spectacular approach of a menacingly black thunder cloud, waiting for the summer storm to loose its fury, without wondering where it came from, how it was formed, and where it accumulated its store of energy that suddenly beats down upon the earth in the form of raindrops, hailstones, or whirls of wind?
WHOLESALE street washing on a retail scale has been achieved by the town authorities of Baker, Oregon, through the use of a strange pipe line on wheels, similar to the smaller pipes used abroad. The town had water to spare, but the amount of hose required to reach some of the streets made street flushing an unwieldy proposition.
TO FACILITATE the task of fingerprint experts in the detection of crime, George Blum, official photographer of the San Francisco Police Department, has devised a special camera that supplies the illumination at the same time that it is recording the view.
HOW many miles of travel can be saved yearly in a factory by a scientific rearrangement of the routes along which materials move? This is a question easily solved by Major Frank B. Gilbreth, efficiency expert, using a pocket map measurer.
IN THE future, forest rangers in Minnesota will fight fires with new portable pumps light enough to be carried by one man instead of relying upon gunnysacks, picks, and shovels to open fire lanes. The pump weighs less than 75 pounds, including a gasoline engine with its 3-quart tank filled with gasoline.
THIS is the age of power. Electricity and gasoline are emancipating the human race from the slavery of primitive drudgery. The America of 50 years hence is taking shape now. To visualize it, to picture the details of the civilization our children will live to see, it is necessary only to look about and see what's going on.
Here is the city of to-morrow as conceived by Henry Ford—an agricultural-industrial community in which, he believes, life for every individual will be healthier, happier, less monotonous, and more useful. At intervals along the banks of a stream, like jewels on a string, these communities are situated where natural power is easily available for hydroelectric development and the land is tillable.
Tailor Hoffman's Luck Was to Fall Downstairs, and He Turned into an Idea for a Steam Presser that Won Him a Fortune
"Adon's Steam Arm"
The Beginning of Fortune
The Public Was Skeptical
Aids Other Inventors
Electric Woodworker Can Do Fifteen Jobs
John Walker Harrington
WHEN young Adon Hoffman fell headlong down a dark stairway and broke his arm while employed as an apprentice in a little tailor shop at Syracuse, New York, he conceived the idea of a clothes-pressing machine that he could operate with his foot!
A Simple Story of the Elementary Principles of the Most Mysterious Force Controlled by Man
Protection of Radio Sets from Lightning
"Induction" and "Capacity"
The Hard-Working Condenser
How Radio Waves Are Formed
"Direct" and "Alternating" Currents
Dr. Charles P. Steinmetz
THE tremendous interest in radio today has brought hundreds of thousands of persons into close contact with electricity as an important influence in their lives; for they have discovered that if they are fully to enjoy the benefits of this newest marvel of communication, they must understand its secrets a little more clearly than ever before.
To Keep in Trim without Strenuous Exercise, Try a Massage
ON THE theory that body massage is a more effective health builder than the usual run of calisthenic exercises, Albrecht Hensen, of New York, has worked out a system of massage movements that has received the indorsement of some of the foremost physicians.
A CONTROL device, invented by William J. Maxwell, of Brooklyn, New York, makes it possible for a person who has learned to play one instrument to play simultaneously any number of other instruments in harmony and rhythm. For example, the inventor, playing the banjo as the master instrument, at the same time plays the xylophone and orchestra bells.
YOU'RE missing lots of profitable fun this summer unless you have joined the growing army of POPULAR SCIENCE MONTHLY readers who are out with their cameras to win $50 Three Prizes Each Month $50 These prizes are offered by POPULAR SCIENCE MONTHLY for the most interesting photographs of new inventions, mechanical and scientific achievements, or personal adventure.
COMBINING a power drill and a hammer in a single tool, T. S. Payne, of Lincoln, Nebr., has invented a portable machine that will drill holes in steel, wood, or stone. The change from drill to hammer is accomplished by a quarter turn of the milled head just below the motor.
Coal Machines Make American Miners World Champions
UNCLE SAM is the world's champion coal miner, thanks to Yankee ingenuity in inventing machinery with which he is able to dig annually 200,000,000 tons of coal more than Great Britain's output—and that with a quarter of a million fewer miners.
Huge Pontoon to Raise Treasure Ships from Ocean Depths
SUNKEN ships with cargoes worth millions will be raised in 24 hours from depths as great as 350 feet—far beyond the reach of divers, if a gigantic pneumatic salvage machine invented by J. W. De Vito, of Boston, proves as effective in the full sized machine as tests with a model indicate.
HOW to recover a motion-picture film for a second run through a projection machine without rewinding has been a mechanical problem ever since the movies became popular. Now Charles F. Herm, of New York, claims to have invented a successful automatic rewinder that will fit into the space assigned to the rewind reel in the ordinary commercial projection machine.
WHEN the United States Forest Service began its work of reforestation, scattering tree seeds in woodlands thinned by lumbermen, so many seeds were eaten by birds and chipmunks that few trees sprouted. But now the seeds are treated with red lead in a way that makes them inedible without detracting from their vitality. The seeds are spread on canvas strips and thoroughly mixed with finely divided red lead, which clings to them, so that animals and birds leave them alone.
YOU can engrave your name in the barrel of your fountain pen by a new embossing stamp operated with electricity. It is so designed that a person of limited experience can cut the letters with no danger of cracking the pen. The embossing stamps are set in the periphery of a disk, and heated by the electric current so that they melt the rubber as it is brought into contact with them.
A NEW and extremely compact welding outfit that may be carried wherever oxyacetylene gas is available permits the garage owner to use the equipment anywhere in his shop without sacrificing space. The entire outfit of torch, extension tubes, gas regulator, and hose connections fits in a case less than 15 inches square—slightly larger than the case of a folding typewriter.
MECHANICAL smokers that inhale four cigars at once are part of the testing equipment used by the cigar manufacturer to insure that your cigar shall burn evenly. The manner in which various kinds of tobacco will burn when they are actually being smoked, and the effect of various blends, are being tested in this way by David E. Brown, of the Department of Agriculture.
FOOLPROOF protective curbings that compel the careless driver to approach railroad tracks slowly have recently been invented by K. W. Carter, of San Antonio, Texas. Instead of a gate, the approach to the crossing is guarded by curbings of concrete a foot or more in height, laid out so as to form a narrow, curving passageway through which the vehicle must pass.
WINDSHIELDS on the upper deck of the city buses of Detroit, Mich., afford comfort to passengers traveling in the open air during chilly weather. The shield acts like the curved "dodgers" on the bridge of a torpedo boat destroyer, throwing the current of air over the heads of the passengers.
YOU can make a dynamo of the front wheel of your bicycle, and light the head lamp with the current produced, by means of a new device that is rapidly becoming popular in Europe. A small electric generator is attached to the front fork, with a driving shaft ending in a rubber disk resting against the side of the front tire.
THE commercial airliner of the future will probably resemble closely the airplane pictured here, especially if intended for supermarine travel," writes Captain Rickenbacker, first American ace during the war and now head of his own motor-car company.
WHERE are the young men who are going to make brilliant aerial careers for themselves in the next few years? Whose will be the names written large on the sky, in terms of fame and financial success, when the great boom of commercial flying comes?
WHEN Ralph C. Diggins, a young school teacher, decided in 1911 to learn to fly, he spent six months and $800 in a "flying school" without getting off the ground. So he determined that the only way to fly at that time was to make his own machine and fly it.
Grover C. Loening, a Big Name in Aviation at the Age of Thirty-Four
AT THE early age of 34, Grover C. Loening, America's most successful young airplane designer, is president of his own aircraft manufacturing company and was recently awarded the Collier trophy for the greatest achievement in aviation in 1921—the perfection of a monoplane air-yacht approved by the Underwriters' Laboratories.
TWENTY-SIX hours, 19 minutes, and 35 seconds in the air! That's the world's endurance record for aircraft, set by Eddie Stinson and his partner, Lloyd Bertaud, at Roosevelt Field, Long Island, N. Y., on December 29, 1921. Stinson's career as a commercial aviator is one striking example of the fame that a good pilot can achieve in cross country flying if he seizes the opportunities that are opening wider daily.
How Glenn H. Curtiss Won Financial Success in the Air
The Boy Mechanic
His War Record
THE one outstanding financial success in American aviation is that of Glenn H. Curtiss, author of the above article. Not so many years ago, he was a young bicycle repair man with only a public school education, received in his home town, Hammondsport, N. Y. But inventive and mechanical ability and grit were among his gifts.
FLYING almost out of sight, to a height of 40,800 feet, Lieut. J. A. Macready shattered the world's altitude record Sept. 29, 1921. He is now chief test pilot at McCook Field, Dayton, Ohio, where he passes upon all new improvements, both of engine and plane, as they are submitted to Uncle Sam.
WHENEVER an airplane meets disaster, many people throw up their hands in horror at the "fatal riskiness" of aviation—forgetting, perhaps, our national yearly average of something like 9000 deaths in automobile accidents. While no pretence can make out flying as a wholly "safe" mode of travel, its comparative safety is shown by the 1921 records of flying compiled by the Aeronautical Chamber of Commerce of America.
THE golf enthusiast may save energy for the next drive by the use of a new golf ball retriever, fastened to the putter handle, by which he can pick the ball out of the cup or from the green without stooping. The novelty consists of a small nickel-plated brass cup the inside diameter of which is exactly the same as that of a golf ball. When the ball falls into the hole, the handle of the putter with the retriever in place is inserted, and pressed over the ball, which is caught in the cup and withdrawn.
NOW that a corkscrew on a pocket knife serves only as a reminder of days gone forever, it has been replaced by a small monkey wrench that is a convenience in working around an automobile. The new knife is large pocket size, and its outfit of tools includes, besides the pocket wrench, a heavy knife blade, a screwdriver, and an arrangement to cut wire.
Weighing Jacks Protect Highways from Overloaded Trucks
WEIGHING jacks with which the load carried by a heavy truck may be ascertained by road police are helping Maryland protect its new state roads from damage by overweight vehicles. Most roads are constructed to withstand a moving load of 10 tons.
ONLY a crew of ants could find deck room in the model of the clipper ship Ariel, constructed by J. A. Bellhouse, of Medford, Mass., and said to be the smallest accurate ship model on record. Although but 5½ inches in length, the model is completely fitted with gear and rigging, constructed exactly to scale, and is a masterpiece of microscopic craftsmanship.
SEED for planting pine forests in connection with the Federal reforestation program is gathered by robbing squirrels of the hoard of pine cones collected for winter food, and threshing the cones in homemade churns. The forest rangers first allow the cones to dry thoroughly in the sun and then throw them into a framework covered with a galvanized wire cloth.
SEMI-OVERALLS, or protectors for the lower half of the trouser legs, have recently been invented by Edward L. Richardson, of Brooklyn, N. Y., for use by those who wear dusters to protect their clothes. The protectors are suspended by straps from the belt and, fitting loosely, will not wrinkle the trousers.
PASSENGERS on vessels at sea anywhere near New York City may now receive free medical advice by radio. A wireless dispensary is available every hour of the day and night. Last year more than 50 cases were treated in this way. Although most seagoing vessels areequipped with radio, about 80 per cent have no doctors aboard, and thus a population equal to that of a small city is constantly afloat within radio distance of New York without medical attention.
THE depth of an oil well can now be ascertained accurately at any moment by a simple gaging machine recently designed by C. E. Van Ostrand, of the United States Geological Survey. The apparatus consists of a wheel mounted between two parallel bars that hold it over the opening of the oil-well casing.
Mechanical Surveying Machine Maps Hillsides and Valleys
Like a Giant Tracing the Landscape
How Photographs Are Taken
Machine Draws Contour Lines
BY MEANS of a newly invented camera and drafting machine based on the principle of the stereoscope, it is now possible to make an accurate surveyor's contour map mechanically, plotting every ditch, hillock, and tree stump on a mountainside several miles away to an accuracy of inches—and this without calculation and without sending a surveyor over the country.
SQUEEZING mild steel into the cracks and folds of a soft rubber washer, as into a die, deforming steel bars with an ordinary paraffin wax candle, and compressing water to 20 per cent of its original volume are some of the physical marvels possible at a pressure of 300,000 pounds a square inch, reports Mr. P. W. Bridgman, of Harvard University.
"UNNCLE" Horace Rees, of Lowville, N. Y., dean of American cheesemakers, recently celebrated his eighty-first birthday by pouring the largest cheese ever manufactured. It is a monster, standing over six feet high, and weighing slightly over 12 tons—enough, it is computed, to make 300,000 sandwiches.
POGO sticks were invented about 300 years ago by a blacksmith in a Transylvanian village who wanted to keep his feet dry, according to Mr. G. Pilarczyk, of New York City. His account is as follows: Pogo was originally the name of a small Transylvanian village on the bank of a stream, across which lay the cattle pastures.
WHEREVER there is a job of heavy shoveling, the mechanical loader, invented by A. H. Lessman, of Des Moines, Ia., does the work with the power derived from a small tractor. The driver, sitting in the tractor seat, controls the tractor by operating a single lever.
CITY streets and sidewalks may be converted into temporary billboards by an invention resembling a lawnroller that prints the advertising message in water on the asphalt. As the machine is pushed along by its operator, a spray of water from the tank in the upper half passes through a perforated belt or drum that acts as a stencil.
IN THE historic old churchyard of St. Mark's in the Bouwerie, New York City, are two trees growing from one root, although they stand 20 feet apart. While endeavoring to reach one of the old burial vaults in the yard, the sexton discovered that when the roots of a very old tree expanded, they came in contact with the vault roofs and were unable to grow downward.
THAT blindness does not bar the person thus afflicted from being self supporting has been demonstrated by Miss Grace Keator, a young blind woman of New York, who is shown above in her office, reading the raised characters of machine-made stenographic notes which she transcribes on a conventional office typewriter.
TOSSING away coins for charity has become a "rattling good game" since E. Fred Cullen, a Boston business man, invented a money scoop for use by the Red Cross in collecting funds for disabled soldiers. Instead of handing your money to a collector, you toss into the scoop.
SKYSCRAPER lumber piles that tower from 60 to 75 feet above the roadway are becoming common in the lumber yards of Puget Sound since the introduction of a mechanical stacker that works on the principle of a bucket loader. The planks are placed in brackets attached to an endless chain, lifted over the top of the tower and down the other side, where they are transferred to the pile.
GOLD 1/2,798,000 of an inch thick, or 10,584 times thinner than the ordinary sheet of printing paper has recently been produced. One grain of the precious metal of this thickness covers nearly four square feet of area and is perfectly transparent.
YOUR health may depend upon the skill with which inspectors of clinical thermometer tubes recognize microscopic defects in the glass. Thermometer "canes" are now tested for uniformity of bore, perfection of the magnifying effect of the rounded front of the tube, and for freedom from blister bubbles and other exterior defects.
NOW comes the portable bicycle to join the company of portable typewriters, sewing machines, phonographs, and garages. The new invention was designed for the convenience of travelers and motorists, for use on tours and camping trips—wherever space is valuable.
Retarding System, Based on Invention of Self-Sinking Pile, Forces the Missouri to Form Sand Bars and Protect Its Banks
To Save Rich Farmlands
Mat of Trees Retards Current
Vast Farmlands Await Rescuers
How a Railroad Was Protected
FOR 41 years engineers have battled to bridle the turbulent Missouri River; yet each spring the unruly stream, roaring defiance to the mastery of man, has torn itself from its channels, plowed through fertile fields and destroyed bank protections designed to curb it.
WHAT is said to be the first practical steam truck built in the United States has just made its appearance in a two and a five ton model. The fuel used is kerosene. A fire tube boiler is located under the hood, and the engine is geared directly to the rear axle; in fact, since the differential housing also forms the crankcase, the engine and rear axle are one unit.
UMBRELLA tags, displaying the owner's name and address, that fasten firmly to the stick above the upper catch, and are protected from the rain by a thin sheet of celluloid, have been invented by E. L. Gaines, of Seattle, Wash. Many a man carries around a borrowed umbrella sincerely believing that he bought it himself.
WIRE ropes instead of steel beams were used recently in a novel temporary bridge of 110-foot span constructed over the Kern River, Calif. The bridge is a rigid-deck truss, although four 1¼-inch wire cables act as its bottom chords. Construction was quick and easy, for the use of rope obviated the necessity of false work.
A PRINTING press for lemons and oranges, that will imprint on the fruit itself the grower's trademark, is the invention of Fred J. Sevigne, of Milford, N. H. It can be utilized for marking any spherical or near spherical object, from baseballs to eggs.
KEEPING up with the blueprint machine will be easier for draftsmen whose work is expedited by this electrically lighted tracer. An electric light located below the work shines through the paper, and a tracing may be made more quickly and far more accurately.
BY SHOOTING bullets through a stick of high explosive held in the hand, H. P. Bostaph, of Detroit, Mich., proves that his new product may be roughly handled with impunity. While it has the power of dynamite when exploded with a detonator, the inventor claims that it cannot be exploded accidentally even if tossed into a fire or struck by a heavy hammer.
BOLTED upon the compound rest of a lathe instead of to the toolpost, a new universal lathe grinder is so mounted as to secure greater rigidity and to eliminate chattering. As the frame is of aluminum alloy, the weight is kept to 22 pounds without loss of mechanical efficiency.
"HE'S—out!" The runner may kick and the fans howl. The umpire has decided and that settles it. But was the runner really out? Until Arche M. Dunning, photographer, of Los Angeles, Calif., perfected a new method of photographing close plays, no one could say certainly whether the arbiter was right or wrong, unless a news photographer caught the play from close at hand.
To protect themselves against stones, broken bottles, and other missiles hurled at them by rioters, Egyptian police are now equipped with small wicker shields. Front and back views of the shields are shown at the left. This light, tightly woven armor is as effective in stopping "brick-bats" as is the steel armor worn by police in our large cities in stopping bullets
Dogs that earn $100 a week appeared recently in person at the office of the Income Tax Collector of New York City to swear to their returns. The canine plutocrats all gave their occupations as "actors." Most highly paid dogs are in circuses, but some are in the movies. Two of these "actors" are said to draw salaries as high as $50 a day
At least 15 omnibuses are pulled apart and reassembled daily in the centralized motor-bus hospital of the London General Omnibus Company. The photograph below shows part of the standardized equipment for handling bus bodies—a body lift and electric truck
With a wooden disk tightly strapped against his chest, from which extends a wooden rod about a foot long, with a clamp on the end for holding a pencil, this armless man soon learned to turn the pages of a book, to sketch, and to write legibly. Use of the device is being taught in the hospitals of London, England
A new use for the electric fan—for hat trimming—has been discovered by Miss Ethel Beech at Miami, Fla. She electrified society there by appearing in a hat trimmed with clothespins, set off by a small electric fan and two dry cells, as pictured above
HIGH tension fuses, resembling the simple device used on lighting circuits have recently been perfected for use on circuits carrying upward of 115,000 volts and 400 amperes. Tests on high voltage short circuits seem to prove these fuses act more rapidly than the oil circuit breaker usually employed.
ANNOYED by the drudgery of continually winding his phonograph, Allen D. Bosworth of Brooklyn, New York, invented a steel tape which would replace the crank. He mounted a sprocket, about four inches in diameter on the end of the shaft, and passed steel tape about it.
THAT baled hay can be scientifically and quickly analyzed,to determine its food value before it is fed to live stock, has been proved by H. B. McClure, hay specialist of the Department of Agriculture. His invention of a sorting table with six compartments enables inspectors to separate the various kinds of grass of which a bale of hay is composed and to grade them according to their amount of nutritive value.
CLAIMING to be "a motorcycle for cost and an automobile for comfort," a new vehicle combines the two wheels and handlebars of the former with the chassis and spring suspension of the latter. The result is a light, fast means of motor transport for one person.
LOSS of both arms has not prevented William A. Winemiller, of Spencerville, Ohio, from becoming a crack rifle shot, famous throughout northwestern Ohio as the "armless sharpshooter." He has already won 10 consecutive shooting matches this year.
EVERY third farm in the United States has at least one automobile; but only one farm in 28 has a tractor, and only one in 50 a truck. Since only 40 per cent of farms have telephone connections, the auto seems the most desired adjunct to rural life. Even now only one farm in 10 has water piped into the house, according to the report of the United States Census Bureau.
A NEW electrical machine that winds tarred twine around wire cables to protect them from rust consists of a movable frame that pulls itself along the cable, and a rotating mechanism that winds, or "serves," the twine tightly at the rate of three feet a minute.
ELECTRICAL reproduction of phonograph records by a device that eliminates the horn and gives the listener complete control of the volume of sound, has recently been perfected by E. T. Jones, of New Orleans. His invention consists of a coil close to the phonograph reproducer, the vibrations of which are said to set up feeble currents.
GOGGLES that give moving pictures perspective and depth, and at the same time enable the spectator to see the pictures in any general color he thinks the action requires, have just been invented in Europe. Three colors are usually supplied—green for outdoor scenes, blue for the night close-ups, and red for fires.
SLIPPING down a steep mountainside recently near Slate Run, Pa., a 4-inch log drove through a 12-inch tree like a cannon-ball, suggesting that momentum, rather than hardness, is the great factor in penetration. The small log struck the tree a blow of 30,000 foot pounds—equal to the impact of 15 tons falling one foot. This is calculated on the basis that the log weighed half a ton, and gathered a speed of 20 miles an hour in its course down the mountainside.
A HAND-OPERATED wallpaper machine that automatically performs the technical details of papering has been invented by Stanley Pytlak, of McMechen, W. Va. The roll of wallpaper is placed in a metal cylinder, from which it is unrolled by the turning of a crank.
Torches Cut 18-Inch Steel Armor into Five-Foot Lengths and Giant Shears Snip Destroyers Apart in Newest Industry
How Ships Are Torn Apart
Armor Plate Cut into Blocks
Junk of Greatest Value
Old Troopships Are Valuable
THE greatest junk business in the history of the world sprang up almost overnight when the recent Conference for the Limitation of Armaments, in binding the United States, Great Britain, France, Italy, and Japan to "keep the peace," decided to discard more than 2,000,000 tons of fighting ships of three leading powers.
A NINE-HOLE golf course has recently been installed in a department store in Portland, Ore. The length of the fairways varies from five to 25 feet, but the putter is not the only club used in the indoor game. To play the "bunker hole," for example, you must drive from a tee over a high bunker and into a net beyond.
YOU can work comfortably on the flat of your back under the car, if you lie on a garage creeper with a headrest that you can raise or lower by pulling a hand lever. The end of the creeper consists of a padded cushion about six inches wide, supported by two pairs of flat steel bars, pivoted in their centers, with their lower ends sliding on two round bars extending across the creeper beneath the frame.
WHAT the audience of a motion-picture show sees as a long jail corridor is in reality only a series of arched doorways made of canvas. By an entirely new system of forced perspective a well known producing company has succeeded in producing the effect of a large building with the minimum amount of construction.
YOU can now prevent your checks from being raised by using a newly invented fountain-pen equipped with a sharp steel wheel, mounted in the base, which shreds the fibers of the paper and forces in a red, acid-proof ink. This protects the amount and payee's name just as they are safeguarded by a mechanical check protector.
A BACK rest that converts an oak thwart of a boat into an armchair has recently been invented by Messrs. Polhamus and Gillette, of Los Angeles, Calif. While the oarsman is rowing, a spring in the metal frame holds the rest constantly against his back.
A NEWLY perfected semi-automatic welder is said to double the speed of the hand-operated welder, while retaining the continuous features of the full automatic machine. It allows the operator to direct the arc and is designed for welding products where the seam is of irregular contour, or the work too large to permit the use of the automatic machine.
Collecting Atmospheric Energy with Metallic Bags, Experimenter Claims to Have Found a Way to Utilize "Free Electricity"
Spikes Cover Balloon Surface
Would Prevent Thunderstorms
P. J. Risdon
WILL the vast reservoirs of dormant energy, represented by the difference in potential between the atmosphere and the earth, be harnessed at last and utilized to light and heat our homes and to turn the wheels of our factories? The limitless supply of potential energy all about us has long been recognized.
YOU can stop either a fire or a burglar with a recently invented gas pistol consisting of a small cylinder filled with compressed gas, and slipped onto a pistol grip handle. The pistol is discharged by simply pulling a trigger. This releases a pin, which punctures the container.
PROJECTING arms which are extended from the rear of a street-car at stopping-points will afford passengers descending from the cars real protection, if the invention of Col. Charles Gore of Los Angeles, Calif., is adopted. Many accidents have already been prevented by the present "safety zones," although these depend on automobile drivers' knowledge of and obedience to traffic rules.
TINY alarm clocks, measuring 1¼ inches square, are the latest novelties to appear on the market. One handle winds both the time and alarm springs, while the entire case forms the gong for the alarm. The clock is constructed on practically the same principle as the familiar alarm watches.
IN A new type of envelope sealer, the envelopes to be sealed are stacked with their flaps down and toward the front of the machine. Then a thin brass plate moves up as a hand wheel is turned and, sliding in between the envelope and its flap, moves the envelope ahead.
IRON that will not rust has recently been produced in Sheffield, England. The new product is said to be superior to the so-called stainless or rustless steel, since it is rustless in the ordinary state, and does not require heat treatment. It can be worked in the cold, soft state by all mechanical processes, and after being polished becomes rustless. It seems to remain so indefinitely. In tests after protracted exposure to the fume laden air of industrial centers, the polish on the metal was as bright as the day it left the mill.
FOR the use of institutions that desire to economize by combining an ambulance and a pallbearers' coach in a single vehicle, a limousine has been constructed that may be converted at will from one to another of these uses. In appearance the car resembles a standard limousine. By folding up the seats on the side, and dropping the forward seats into a recess at the front of the compartment, the machine will admit a regular ambulance cot through the double doors.
Pinching Fingers Deadens Toothache, while Rubber Band on a Toe Will Ease Smashed Thumb, Says "Zone Therapy" Expert
Zone Theory Is Demonstrated
How Zones Divide the Body
Rubber Bands May Be Used
Pain Zones of the Body
Ralph R. Perry
HAVE you ever, after accidentally pounding your thumb, seized it and held it tight to stop the pain? Do you know that when you did this, you were unconsciously applying one of the secrets of an extraordinary medical discovery of the day, called "zone therapy"?
Corn Fuel Is Cheaper than Coal for Firing Brick Kilns
CORN may be used as a standard fuel in firing the brick kilns of a clay products company at Adel, Iowa. At present prices of corn and coal, more heat can be obtained by burning the corn itself than by selling it and burning the coal it would buy.
AMERICAN astronomical observatories will no longer be compelled to buy their best telescopes abroad, for Donald F. Sharp, of Buffalo, N. Y., has succeeded in casting and polishing a 40-inch reflector mirror that weighs half a ton. Cooling the huge piece of glass with perfect equality throughout is the great difficulty in making such a mirror.
DOCKING a liner without a tug is difficult even for the most skilful pilot unless he has accurate knowledge of the position of the ship's rudder. With an electric rudder indicator developed by the originators of the gyroscope compass, the position of the helm can be determined to a degree.
AN APRON trap for the bowling alley, to prevent the ball's rolling back from the rack end of the return trough has recently been invented by Walter Choinski, of Milwaukee, Wis. Balls returned to the bowler frequently do not have sufficient velocity to ascend the incline that delivers them to the storage rack.
WALLS of soft, sticky mud served as building forms in the recent construction of a unique summer house, of irregular and fantastic shape, which not even the builder, a resident of Cincinnati, can duplicate. The completed house, which appears as if it had come out of some book of fairy tales, is formed of concrete; yet during construction a huge and apparently shapeless mud pile rose on the site.
Air Blast Mixes Concrete Evenly in New Automatic Machine
Material Receives Thorough Coat
THE problem of mixing the ingredients of concrete in the correct proportions and at the same time so thoroughly as to insure a perfect coating of cement around every particle of sand and every piece of stone has been met successfully by a recently perfected portable mixer in which cement is blown by a fan in a cloud that covers the aggregate.
GRASS growing on terraces can be cut as easily as that upon the level lawn by using a lawnmower with an adjustable handle, invented by Robert R. Kitchel, of Ridley Park, Pa. Pressure on a toe clip locks the handle at the angle desired. The operator walks on level ground at the foot of the terrace, and cuts one longitudinal swath above another on the sloping surface.
ONE nut, instead of the usual eight or ten, locks a new demountable rim, invented by H. N. Moody, of New Orleans, to an auto wheel. The tire may be tightened or released almost instantly by means of a locking cam. To the surface of the felloe are welded 10 metal cleats placed at an angle of 15 degrees.
GLIDERS manned by dummies will be used to test the anti-aircraft guns of the Atlantic fleet during coming maneuvers off the Virginia capes and Cuba. During the bombing tests off the Virginia capes last fall, naval officers objected that the tests were not convincing, since aviators would be shot down if they should attempt to approach a modern dreadnaught and launch their bombs as deliberately and from such low altitudes as they did against the anchored German ships.
BY TRANSFERRING 30 tons of coal from the bottom of a gondola car into the coal dealer's trucks in an hour, a newly designed belt-type car unloader is said to enable the small dealer to handle his material as cheaply and efficiently as would be possible in larger scale operation with raised trestle and gravity bins.
NOW that the world is at peace, the United States Chemical Warfare Service has declared war against the pests that eat up the farmer's profits. Phosgene and mustard gas are proving as effective against rats as against an advancing enemy.
Is a single-wire aerial as good as a multi-wire aerial for radio receiving purposes? In speaking of a four-wire, 100-foot aerial, does the length refer to the length of each wire or to the combined length of all the wires?—W. S. U. For receiving purposes, a one-wire aerial is just as good as a multi-wire aerial.
SHIPPING bricks in individual cardboard cartons, as if they were fragile as eggs, has been found profitable by a Los Angeles concern. Formerly, finely pressed and enameled bricks were often chipped and broken in transportation. The new protection eliminates breakage entirely.
IT'S a long stretch, but the rubber still holds. The test stunt shown above is one method recently adopted by a rubber company in testing the flexibility of the inner tube of a bicycle tire. The tube, lifting wheel and rider from the ground, supports a total weight of 222 pounds.
A VARIATION of golf was demonstrated recently at Pasadena, Calif., where Samuel G. McMeen has startled orthodox golf players by appearing on the links with bow and arrow. McMeen challenges all comers. As his opponent drives his ball, the archer-golfer shoots his arrow.
ONE dictaphone trains 10 typists at once in a modern business school. One machine is connected with a hollow tube running down the center of a table. The students plug their ear-tubes into small holes in the tube, and all 10 may take dictation simultaneously from one record.
AN IDEA of what happens to the bottom of a ship when it is washed in a gale for a mile over reefs and through the surf is pictured above. When the disabled tank steamer F. D. Asche was towed into New York harbor recently after a battle with a West Indian hurricane, in which she was wrecked on the Bahama reefs, shipping men characterized her as "the ship without a bottom." Nearly every section of her steel bottom resembled the crumpled sole of an old shoe.
WITH Austrian crown notes worth only three hundredths of a cent, money was the cheapest material this German could buy to paper his room. European paper currency is so cheap that bills are even twisted into paper bags and sometimes used for pipe-lighters.
IN THE heart of a genuine pearl lies a mysterious, unseen quality that gives the gem its warm beauty and its value. What is it? How can this quality be detected so as to distinguish positively between the real pearl and the imitation? One way has been discovered—by the strange, invisible rays of ultra-violet light.
Huge Searchlight Mirrors from Molecules of Copper and Silver
WHEN huge mirrors, five feet in diameter and perfectly formed, were needed recently as essential parts of army searchlights used in night signalling, scientists found a way to manufacture the mirrors in quantities without the employment of large numbers of skilled opticians.
TWO hundred miles an hour—more than three miles a minute—nearly 300 feet a second! Measure that 300 feet with your eyes, then watch the little hand tick off one second, and you will have some idea of the fastest man-made thing in America. It is the triplane known as the Cactus Kitten, with which Clarence Coombs took second prize at the Omaha air meet and in which he intends to try for the official world's speed record this summer.
Medal-Making Machine Reproduces Finest Work of Artists
Drill Cuts Replica in Steel
A MACHINE that automatically reproduces an artist's bas-relief design to any scale without alteration of the slightest detail is responsible for the artistic perfection of the latest coins and medals. Guided by soft wax forms, drills now eat their way into solid blocks of steel, turning out dies that are exact copies of the sculptor's work—a thing that was virtually impossible with hand die-cutting.
IT IS a fact not always recognized that, when water-pipes burst, the damage is actually done at the time the water within them is frozen. We only become aware of the burst when a thaw sets in and the pipe begins to leak. Beyond emptying all exposed pipes during, or in anticipation of, a hard frost, no satisfactory expedient has yet been devised for preventing these unfortunate accidents until this simple scientific device illustrated was patented.
ROLLING a 65-ton dynamo rotor ten miles over the road to a power house proved to be easier than delivering it on a special truck. The grades over which the machine had to be hauled were as high as 10 per cent. It was found that two tractors could roll the rotor, while seven motor-trucks, in addition to two tractors, were required to draw a similar machine.
IN ENGLAND, motor-trucks with special box-stall bodies are now being used to transport race horses from one track to another. It has been found that travel on railroad trains is extremely hard on the physical and nervous condition of a thoroughbred.
INVALIDS can now shave comfortably in bed, thanks to a new mirror that clamps on the patient's knees and that may be easily adjusted. The mirror, an invention of Harry J. King, of Oaklandon, Ind., is supported by two L-shaped members working on a hinge at their junction, and padded at the lower end so that they may be clamped either to the bed or to the knees. The glass is attached by a universal joint to a rod sliding through the central hinge, and can be raised, lowered, or turned to either side, and held in the desired position by tightening the wingnuts.
THE volume of tone from a banjo can be doubled, it is claimed, by a new sounding-board that collects the vibrations of the under side of the head and delivers them through a horn straight at the audience. In most banjos only part of the possible tone volume is heard, as the instrument must be held close against the body of the player.
WHEN great icebergs, breaking away from the winter pack off Newfoundland, drift southward across the transatlantic steamship lanes, the sea captain is confronted with one of the most deadly perils of the sea. As his ship plunges through darkness and mist at 20 miles an hour, he anxiously peers into the gloom ahead, watching for the frosty gleam that may warn him, perhaps too late, of disaster.
DIFFERENTIALS, propeller shafts, friction clutches, speed gears, and other trouble makers have been eliminated in a gasoline-electric motor car, recently developed. The motive plant of the automobile consists of a two-cylinder gasoline engine, the crankshaft of which is parallel to the front wheel axle.
MOVING pictures of a furnace fire photographed through a metal screen by Mr. Sanford Riley, of Worcester, Mass., have supplied new facts of what actually happens in mechanical stoking. As a result, a mechanical stoker of twice the customary size, having a coal bed 20 feet instead of 10 feet long, may soon be commercially practicable.
Best Solution to This and Other Puzzles on This Page Will Win $25 in Prizes
Count the Rectangles
What Did the Squire Get for His Horses?
How Many Bricks in Hod?
June Puzzle Solutions
WHEN the glaziers had completed the window in the professor's new bungalow, that astute gentleman contemplated the work, then spoke as follows: "In viewing your admirable artistry I perceive that within the large square formed by the boundary of the window there are 16 small squares, and that the dividing lines of the panes form an interesting variety of rectangles.
FOR the mechanical draftsman a universal adjustable set-square with which it is possible to draw lines at an angle much faster than when using a protractor, has recently been invented. The instrument is a celluloid 45-degree triangle, one face of which is in the form of a hinged blade equipped with a scale by which it can be set at any angle.
A canteen that never goes dry has just been invented by Dr. Alexander Graham Bell, father of the telephone. Even in the desert or at sea the container will assure a constant supply of drinking water, it is said, for it distills moisture from human breath.
A crane that lifts a loaded coal car bodily from the tracks, weighs and dumps the coal, then returns the empty to the rails, has recently been built for use in industrial plants. Two steel tackles ending in double chains that are attached to the car just behind the axles handle the car as shown in the photograph at the right.
By the use of a novel relay tower, the contractor for the North Avenue Bridge at Milwaukee, Wis., recently was enabled to place 17,000 cubic yards of concrete from one central mixing station. The mixture was started from the tower seen at the left in the photograph below, then hoisted to the top of the tower on the right, and distributed from that point through a swiveling spout.
Stretching the backbone to relieve twitching nerves and muscles while the patient is exposed to the curative effects of heat and light rays is a new method of treatment for nervous disorders developed by Dr. Jacob Rcemer, of Waukegan, I11.
Even a broken back doesn't prevent "Sandy," a full grown Airedale, from taking his daily stroll. When the dog was run down by an automobile in Philadelphia recently, the "walker" shown in the illustration was built to aid in his recovery. With his back in splints, "Sandy" is lashed to a framework set on rollers.
Strips of linoleum were laid recently on a busy street corner in Los Angeles to test the durability of the material. When the linoleum, shown below, was removed at the end of the day, it had not been appreciably damaged, although more than 15,000 vehicles had passed across it.
How an Amateur, Advancing by Easy Stages from the Simplest Equipment, Planned the One Best Outfit to Meet His Needs
The Beginner's Ideal
A Portable Outfit
Phones Influence Sound
The Advantage of Knobs
IDEALS differ. Some men select blondes and others are carried away by brunettes. Also, ideals change. The blonde may become first the wife and then the complainant, and the brunette may become the co-respondent. Just so, men are bound to change their minds in radio, advancing from one conception of the ideal radio set to another, as the limitless possibilities of recreation, entertainment, instruction, research, and financial profit through universal communication spread new vistas before them.
The Five Best Ways to Erect an Aerial for Your Ideal Set
EVERY radio receiving set requires some type of antenna. While facilities are not always available to permit the erection of the very best type, still, there is always a one best method of antenna construction for receiving under any given set of conditions.
ONE Popular Science Monthly reader writes us: "In less than six months of radio experience I have bought one crystal set and scrapped it; one set of aerial equipment, which I foolishly scrapped for another; and one detector tube set, parts of which I gave away when I built my two-stage set.
Scattered Thousands Hear Entire Church Services, while Voices from the Air Brighten the Days of "Lifers" in Prison
Convicts "Listen In"
IF THE radio broadcasting station recently installed in the First Baptist Church of Shreveport, La., had sufficient radio power to reach Jackson, Mich., it would be possible for 1800 convicts of a penitentiary to listen to entire church services.
Who Will Invent a Radio Valve?—Use Squeals in Tuning
A Strange Whistle
THE other day, in a downtown lunchroom where I was snatching a hurried midday meal, a tall, angular, and somewhat nervous man sat down beside me with a tray of food. Just before he began to eat, he pulled out a daily paper, tore off the radio program, and began to study it intently.
THE foregoing paragraphs may explain to some of my readers one of the things which has been causing them trouble ever since they took up radio. The condition arises most frequently in larger cities, where, on some apartment-house roofs, you will see as many as seven or eight aerials attached to different sets in the apartments below.
A YOUNG chap came to me the other day, and said: "There is always a terrific grinding noise in my telephones. I am using a regenerative vacuum tube set. I’ve tried to get rid of the noise, but without success. All the sets I have listened to have the same trouble."
AT THE present moment, when the genius of the country is concentrated upon the development of radio receiving apparatus to improve the concerts that nightly are being sent through the air, a set of experiments equally important is being prosecuted.
BY USING the well known principle of the Wheatstone bridge, illustrated in the accompanying diagram, radio engineers recently were able to carry on a two-way conversation by wireless telephone with the steamship America, 400 miles at sea.
COMPLETE equipment for highway maintenance has just been designed by Stanley Able, of Kern County, Calif., in such a compact form that it can be carried upon a single five-ton truck. The unit carries machinery and supplies for practically all varieties of road repairs.
The Story of a Mechanic Who Is Turning His Skill with Tools to Spare-Time Profits in a Novel Way
Wrestling Wrench-Maker Wins in Tool Contest
Winner of First Prize in Contest, "How I Made Money with My Tools"
I AM an auto mechanic who never had much patience in wrestling with the nuts and cap screws hidden away in so many mean places around the average machine. So I started to make wrenches that would get into the out-of-the-way parts with ease—wrenches that would turn corners.
Originality Marks the Prize-Winning Contributions for July
THE outstanding feature of the three prize-winning contributions in the contest, "How I Made Money with My Tools," is their originality. None of the writers is following ordinary methods in earning extra money with his tools. And just as unmistakably the work of each man shows him to be gifted with exceptional mechanical ability.
How to Build a Radio-Phone Set into a Library Table
Neal W. Sanders
FOR one of the boys in a sanitorium who had but limited space in his bungalow, I made the library table for a radio set as shown in the accompanying illustration. The top is 24 by 30 in. and the legs 2 in. square and 29 in. long. The top is in two pieces, the back being fastened solidly to the rails and the front hinged. The base of the instrument panel is also hinged at the back so that it may be lowered out of the way or raised for operation.
IN CASE a drill is not long enough to carry the borings out of a deep hole, they may be removed easily by inserting a magnetized rattail file into the hole. The file can be magnetized by placing it on the face of a magnetic lathe chuck or on the field of a generator for ten minutes. It will hold its magnetic power for several days.
(Second Prize, "How I Made Money with My Tools" Contest)
D. J. Spencer
I HAVE been a blacksmith for 41 years and until a year ago last September I never had time to indulge my great desire to carve. Being out of a job for a few days, I began carving a small sparrowhawk then an eagle, then a group of four eagles, called the "Feast of the Eagles."
WITHOUT ever having read a book on carving or taken a lesson in art, Mr.D.J. Spencer, of Price, Utah, who has spent a lifetime at the forge, turned his hand to sculpture in September, 1920. He is now working on a series of portrait busts of famous men, and has carved Lincoln, Washington, Jefferson, Roosevelt, Wilson, President Harding, and Venizelos.
STATIC, the bane of summertime radiotelephone reception, may be overcome in large part by the use of a simple loop aerial in place of the ordinary outdoor antenna. It will not, however, serve well with a crystal set; a good vacuum tube receiver with several steps of amplification is essential for the best results.
THE typewriters used in a shipping office over a large warehouse were in almost constant need of cleaning, especially in the summer, until a special machine method of brushing them off was adopted. The cleaning was done by means of a small circular brush mounted on a flexible shaft connected with an electric motor, which would be plugged in the nearest light socket.
ANYBODY who had the privilege that has just been mine, of reading hundreds of manuscripts submitted by readers of POPULAR SCIENCE MONTHLY in the Home Workshop's "How I Made Money with My Tools" contest, would be amazed at the variety of ways in which mechanical hobbies may be made to pay cash dividends.
NOISE in plenty for celebrating the Fourth of July can be made with an electric carbide cannon. Not only is such a cannon safe, but the ammunition costs next to nothing, is easily obtainable, and produces a surprising volume of sound. The most expensive part of the cannon is the coil.
(Third Prize, "How I Made Money with My Tools" Contest)
I AM clerk for a hardware dealer who closes his store at 6 P.M., except on Saturdays. My employer made the remark one day that it would be good advertising to leave the show window lights on until 9:30 or 10 P.M., but this would mean that one of us would have to return to the store to switch off the lights at that time.
Youthful Winner of Third Prize Builds Unusual Models
THE winner of the third prize, Mr. Edward Jones, of Frankfort, Mich., is still in his teens. Born in Kemptville, Ont., in 1903, he attended public schools at Milton, Ont., Benzonia, Mich., and Frankfort, Mich. He clerked in stores, washed dishes and tended fires at a hotel in order to earn his way through high school.
Complete Your Paddling Canoe Equipment with a Sail
RUTH D. SHULTIS
THE regulation sailing outfit for an open paddling canoe can be purchased for about $25, but may easily be made for less than half this amount by any one who can handle a few common tools. From my experience in rigging up an outfit for my 16-ft.
Listen-In on POPULAR SCIENCE MONTHLY'S Two-Stage Receiving Set
THOUSANDS of radio amateurs have made and are now receiving broadcasted programs with POPULAR SCIENCE MONTHLY'S two-stage receiving set, described in Blueprint No. 6 of the Home Workshop Service Department's series of blueprints.
A SMALL aquarium, which will be found even better than some that can be bought, as well as cheaper, can be made from a large empty tobacco tin. With a can-opener cut out the sides and top, leaving only a rim ½ in. wide on each side. Then cut pieces of plate-or window-glass to fit.
WHENEVER you make something particularly useful and original in your home workshop, write a letter describing it to the Home Workshop Editor, POPULAR SCIENCE MONTHLY, and send in a photograph or sketch to explain the construction. Not only does POPULAR SCIENCE MONTHLY pay well for available articles, but it also awards special prizes for the "Best Ideas" published in this department each month.
WHEN bread is baked at home, the work will be simplified if a cabinet is made for mounting the dough mixer. The mixer rests in a circular hole in the top of the cabinet and is clamped solidly on the top shelf. The pans containing the dough are placed on the shelves of the cabinet during the rising process, and the baked bread and baking utensils are stored in it at other times.
IF A vacuum cleaner is available, it is a simple matter to dust radiators thoroughly. Hang an old damp sheet or large dustrag back of the radiator, place the blower attachment on the vacuum cleaner, and blow the dust through the radiator on to the damp cloth at the back.
This Arbor, with Its Quaint Gate and Two Seats, Will Add Charm to Your Garden
Make Your Own Radio Set
NOTHING adds more to the attractiveness of a well-kept garden than an arbor, especially if it has comfortable seats. Such an arbor is the one designed by the Home Workshop Service Department as Blueprint No. 9 in the series of working drawings it is publishing to help readers of POPULAR SCIENCE MONTHLY in their work with tools.
FOR this parlor, piano, or reading lamp, a good cabinet wood should be used, such as bone-dry white or red oak, plain or quarter sawed. The lumber may be obtained from a planing mill cut with just sufficient allowance for finishing at the bench, or the parts may be ripped from the board.
Old Films Will Make Durable Markers for Shrubs and Trees
C. C. RICH
IN PLACE of wooden tags, try using old photographic films as permanent markers for young fruit trees, small shrubs and plants. They make neater and more permanent markers. With black ink write the name of the tree or shrub in the middle of the emulsion side of a small film or a piece of a large film.
THIS sketch shows a very useful holder for a draftsman's ink-bottle. It is heavy enough to make the spilling of ink practically impossible. The holder is a 1½ in. standard galvanized pipe cap, which is just large enough to receive the regulation small drawing-ink bottle.
How to Make a Rotary Lawn Sprinkler of Pipe Fittings
THE rotary lawn sprinkler that is described below is made entirely of pipe fittings that can be obtained at any hardware store. The cost is approximately one half that of a sprinkler of the same size bought at the same store. To make the sprinkler, the following fittings are necessary: 3 nipples, ½ by 6 in.
Construct a Variable Condenser with Sliding Plates
Aluminum Makes Best Condenser
L. B. Gangawere
A VARIABLE condenser with sliding plates may be constructed much more easily than the rotary type. One built by the writer has 5 fixed and 4 sliding plates, the fixed plates being 3½ by 3 in. and the sliding plates 3¾ by 2 31/32 in. It has a capacity of about .00075 mfd.
THE tire gage is considered a necessity around every garage and repair shop, yet it is a small article, easily lost, and, alas, also easily stolen. In fact, after a man is through with it, he is apt to put it into his pocket absent mindedly. This difficulty is neatly solved by soldering the gage into a small tin can.
MOTORISTS who are troubled with rain or moisture getting to the distributor and causing the engine to miss will appreciate this solution of the problem. The distributor is enclosed in a section of inner tube that is gathered at the top to form a sort of bag with open bottom.
RADIO enthusiasts who are woodworkers can make a loudspeaker that will give good results with a radio receiving set and two stages of audio amplification. The outside of the loudspeaker may be made of any wood that will match your own wireless cabinet; for best results the interior should be either of white pine or mahogany.
Bottle Serves as Cheap but Efficient Aerial Insulator
John H. Schalek
THE radio antenna insulator shown in the illustrations has been in use for the past two months. It effectively insulates and supports a two wire No. 14 gage flat aerial that is more than 120 ft. long. It has withstood several very severe wind and rain storms during that time without breaking or losing its insulating properties.
Pictures Show Steps in Making Sensitive Crystal Detector Receiving Set
This Is the Now Famous Radio Set of the Home Workshop Service Department's Blueprint No. 7
DESIGNED by experts for the Home Workshop Service Department, this set is one of the best crystal detectors that has been constructed. It has met most exacting tests even to receiving broadcasting on an indoor aerial. Other points of interest about it are: 1. It has few parts and is of simple and practically foolproof construction.
Easily Made Merry-Co-Round Provides Fun for Kiddies
F. W. SHULTIS
A FATHER with several children of his own and an interest in his neighbors' children, constructed this unique merry-go-round on a vacant lot. The stump of a tree was utilized for the base. A piece of 1¼-in. pipe was set upright in the stump and held plumb by pouring cement around it.
A SHELF under the cowl is handy for the automobile shopper or tourist. Small packages may be laid on this shelf without fear of being stepped on or sat upon. When touring, the road map may be kept at your fingers' tips, and your best hat may ride without causing the least ripple of worry as to its safety.
IF AN old bicycle frame is lying useless in attic or cellar, or if one can be purchased cheaply, it will pay to rig it up so that it can be used for operating an ice-cream freezer. The frame is blocked up, bolted rigidly, and braced so that a person can sit on it and pedal; and a chain is used to transmit the power to the ice-cream freezer, on which the crank is replaced by a cog wheel.
Resilient Bait-Casting Rod Was Made from Buggy Whip
H. C. McKay
MANY of the joys of bait casting are missed by the younger fishermen because of the expense of a good outfit. A steel rod has not the necessary resiliency, to my mind, for the finest work, and a good split bamboo rod is expensive. For less than $2.50 I succeeded in making a rod I would not trade for all the fancy ones on the market.
Quickly Made Awning Will Shade Exposed Door Effectively
G. A. LUERS
ONE continuous piece of iron rod is bent to the indicated shape and, after the canvas is attached, it is fastened to the door casing with heavy staples. An awning constructed in this manner, with a projection of about 3 ft., serves to shade a gasoline pump beside a gasoline filling station.
THE rolls of ordinary clothes-wringers usually wear in the center. To repair them two methods may be used with little expense or difficulty. The first is to shave down the ends of the rolls until the diameter of each is constant throughout its length.
Locking a Ford by Modification of the Ignition Key
JACK L. BAKER
YOU can rig up a lock that will answer the same purpose as a special Ford ignition switch lock without costing a cent. The trick is simplicity itself, yet it will fool anybody who tries to tamper with the machine. The working part of the ordinary Ford ignition key consists of one central pin and two side prongs.
A SMALL irrigation system for the garden may be built in such a way that the available water power is made to perform all the labor. The system consists of an overshot waterwheel connected with a small rotary pump by means of a chain drive. From the pump the water is piped to an overhead system of piping, from which the water is sprayed over the plants.
OF COMPARATIVELY inexpensive construction is this floating boathouse. The construction is of the simplest type throughout, from the pontoons to the shed-like roof, so that any one with ordinary skill in handling woodworking tools can confidently undertake its building.
A MECHANIC is often at a loss where to lay his hot soldering-iron. He would not hesitate if the iron had a holder similar to the one shown. It is made of a heavy strip of brass and is so constructed that it can be folded up when not in use. The two legs hold the iron a little above the bench where there is no danger of anything catching fire.
Simple Hoist for Delivering Cement to Second Floor
G. A. L.
THE hoist rigging here shown is a practical application by a local builder of a lever lift used in placing a cement porch on the second floor of a building. The usual practice is to hoist the cement hand over hand with pulley and rope. In this instance a vertical support was placed near the porch, bearing a combined swivel and pivot joint connecting with the lever, which was a "two by four" about 16 ft. long.
FOUR of the most efficient methods for joining electrical conductors are shown in the accompanying diagram. Figures A and B are twisted joints, the second being more quickly made, but not so strong as the first. In C the wires are shown held together with wire rope clamps.
Automatic Gage for Sawing Circles on Scroll-or Fret-Saw
A CIRCLE-CUTTING attachment for a scroll-or fret-saw may easily be made. From a ½in. board cut a circle of any convenient size and chisel a slot in the center for the saw blade. On four different radial lines lay off scales that will represent certain diameters.
PUNCHED holes in metal fabricated work for boilers, ships, and similar work are usually countersunk to overcome the crystallization that may result. A large boiler shop at Waukegan, Wis., has adopted a small shopmade tool for doing this work.
SMALL children delight to play with sand and it is almost as much fun for mechanically inclined grown-ups to make sand toys of wood and metal. One of these interesting toys is the sand dump illustrated. First make a trestle incline and a framework to carry the weight cord.
A STRONG bottle-cap remover for the kitchen or for picnics, where many caps have to be removed at one time, may be made from a piece of ⅞-in. hard wood about 6 in. long and a wood screw. The handle should be shaped as shown and a hole drilled at an angle into the end of the jaw to take the screw.
Knots that All Fishermen Will Frequently Find Useful
ROBERT PAGE LINCOLN
THE hitch shown in Fig. I is excellent for connecting the line to the loop of the gut leader. Generally the fisherman makes a solid knot and often has to cut it off and make a new knot, but this one, while it holds well in service, will come undone when the short end is pulled.
ONE of the United States Geological maps makes an excellent hiking guide, but is awkward to carry when rolled up. If it is creased or folded, it soon becomes illegible, especially at the creases, and in a short time falls apart. To obviate these drawbacks, cut the map along the rectangular division lines and lay them face up on a piece of linen or muslin a trifle larger than the map.
TABLES are often marred by having the varnish burned through to the wood in spots where hot dishes have carelessly been left too long. To repair the damage properly it is necessary to remove the varnish and refinish—a long, tedious, and often difficult job.
THREE or four small, highly polished thumbtacks placed under a T-square will keep it raised above a pencil drawing sufficiently to prevent the lines from becoming rubbed and soiled by the constant shifting of the T-square. This is also helpful when working near the thumbtacked edges of the paper.
MANY amateur photographers think that they cannot take unusual and striking pictures unless they have a costly camera with a fine lens and shutter. That is a mistake, because the ordinary camera will register in black and white on the sensitive films of today as much and more than the eye can see.