Meet the Author of the Year’s Most Fascinating Serial
POPULAR SCIENCE MONTHLY
MANY good friends of POPULAR SCIENCE MONTHLY have told us that the story of “How ‘Borax’ Smith Came Back”—that astonishing romance of science and industry published in our issue of December last—was the best article we ever printed. There are just two reasons why that story was unique.
From $5-a-Week Beginner to Scientific Chief of the World’s Greatest Telephone System
How J. J. Carty, Directing Marvelous Research Work by Army of 3000 Scientists, Has Developed Our Phone Service “Half a Century Ahead of Its Time”
A Great Army of Scientists
Speech Around the World
What Organized Research Has Given You in Service
Every Step Carefully Planned
The Full Metallic Circuit
First Hard Drawn Copper Wire
Early Days of the Switchboard
Machines that Seem to Reason
Evolution of the Cable
Original Use of Vacuum Tube
Harry A. Mount
“THE next step will be direct telephone conversations with Europe.” Just 47 years after Dr. Alexander Graham Bell heard the first feeble sound ever transmitted over a wire, this matter-of-fact, yet tremendously significant statement was made to me by the genius who has led the development of Bell’s baby invention into an indispensable system of communication —by Gen. John J. Carty, vice-president in charge of development of the American Telephone & Telegraph Company.
New Fireproof Floating Roof Designed to Reduce $100,000,000 Annual Fuel Waste, Caused by Flames and Evaporation
Oil Boils without Igniting
How Roof Is Sealed
WOULD you believe that you could envelop a tank full of fuel oil with a roaring fire without inviting certain disaster? By doing that very thing during tests of a newly devised floating safety roof, experimenters of the Underwriters’ Laboratory recently demonstrated not only that oil tanks can be safeguarded from fire, but that the millions of dollars’ worth of oil and its by-products lost each year through fire, lightning, and evaporation, can be saved.
COUE is here! He was scheduled to arrive in America the week this magazine appears on the newsstands. Emile Coué is one of the most spectacular figures in the world today. He is popularly known as the greatest individual healer in history. At his modest home in Nancy, France, this modern miracle worker is reported to have cured 20,000 persons of a host of serious ailments.
Amazing Scientific Discoveries Give New Explanation of Volcanic Flames —Earth’s Center May Be Solid Mass of Precious Metals
What Science Guesses
The Earth’s Contents—The Old Idea and the New Ones
Old Ideas Upset
Weighing the Earth
How the Earth Was Weighed
The Molten Earth Idea
Earth Resists Tidal Pull
Flaming Lava at Night
How Vesuvius Became a Roaring Smokestack
Motor Truck Runs on Coal or Corn
Threadless Wrench Holds Fast in Tight Places
Explaining the "Planetesmal" Theory
World Built by Meteors
Rocks Melt as Earth Shrinks
E. E. Free
ONE of the greatest of all scientific mysteries lies literally under your feet. It is the mystery of what is inside the earth. Suppose you devised some kind of powerful digging machine, capable of with-standing terrific heat and pressure, and suppose you climbed inside it and started downward through the rock and kept on going, mile after mile, until you penetrated all the 3956 miles down to the center of the earth.
The Most Fascinating Serial Ever Published in a Magazine
It Begins in the Next Issue of Popular Science Monthly
Facts You Need to Know
YOU will read in POPULAR SCIENCE MONTHLY during 1923 the most important serial ever published in a magazine. You will enjoy the most fascinating and thrilling story that could be told. It is a tale more absorbing than fiction could ever be.
THE use of high explosives to scrap bulky and unwieldy iron receptacles or machines that have been discarded is replacing the cumbersome method of lifting them entire on cars and hauling them away to be melted. The scraps into which the receptacle or machine is shattered by the blast are not only easier to load on cars, but they also take up less room and thus conserve car space.
Engineers Make Mississippi River Bed Autograph Its Profile
AN AUTOGRAPHIC sounding machine that makes it possible to obtain a detailed and accurate profile map of a river bottom as rapidly as a towboat pulling a barge can move along the line of soundings, has been developed by M. Meigs, Corps of Engineers, U. S. A., and is being used by government engineers to chart snags, shoals, and rocks on the upper Mississippi River.
OPERATED by one man, a new power driven grain binder, developed by a Chicago implement manufacturer, cuts a 10-foot swath and harvests from 30 to 35 acres a day. It is said to mark the greatest step since the invention of the binder in the seventies.
THE process by which the raw hides of animals are transformed into leather is far more complicated than most people realize. After the hides reach the tannery, they are cleaned of blood and dirt and then softened by soaking and mechanical treatment.
HOW Uncle Sam is continually on the alert to prevent you from being “short weighted” when you purchase food is shown by the recent adoption of a bread measuring device by the Bureau of Agricultural Economics. The displacement principle is employed, the volume of a particular loaf of bread being measured by the uniform flow of flaxseed into a graduated tube.
MOUNTED on a swivel ring with ball bearings, the body of a newly invented motor truck, designed especially for transporting heavy materials, 'such as coal and rock, can be rotated so as to discharge its load either backward, on either side, or in any direction between these angles.
MORE thorough cleaning of the teeth is made possible by a small circular brush rotated by turning the sanitary handle to which it is rigidly fastened. The position and pressure of the brush on the teeth are maintained by a second handle through which the shank revolves.
INTERLOCKING asphalt shingles which, the manufacturers claim, will not warp, curl up or blow up in wind or storm, have been designed especially for reroofing old wood shingle roofs without the necessity of tearing off the old shingles.
A RUBBER stamp printing outfit by which the operator can set type without having to read the letters or figures backward has been perfected by a San Diego, Calif., manufacturer. The type units are placed in a hinged wire frame that forms the face of the stamp, away from the face This frame is swung and in it are placed the type units, on which are printed the letters as they will be read.
A PORTABLE elevating loader, operated by and mounted on a Fordson tractor, is a recent contribution to industry by a Philadelphia, Pa., manufacturer. Attached to a regular Fordson tractor and taking its power from the power shaft of the tractor, the loader is said to elevate and load more than a ton of material a minute.
AN AUTOMATIC safety fender for freight elevators has recently been devised by a large manufacturing concern to safeguard operators from being crushed to death by descending cars. The invention consists of a control bar attached beneath the floor of the car and connected with the elevator driving mechanism in such a way that the instant the bar strikes any obstruction it automatically shuts off the power and brakes the car.
BY THE use of dummy teeth mounted on an aluminum plate, dentists are now able to chart quickly the conditions found in the mouths of their patients and to keep a permanent and complete record of every case treated. On the plate is marked a diagram of a normal dental arch.
USING a small single cylinder gasoline engine to start a large one, a concern in Harvey, I11., claims to have solved the problem of turning over the crankshaft of a large road roller engine. Heretofore electric motors and compressed air starters have been used.
THE recent invention of a circular radio calculator or slide rule, by Raoul J. Hoffman, noted aeronautical engineer of New York City, has assisted greatly in the design of wireless sets, eliminating the tedious method of computing values for inductance, capacity, and other necessary figures by means of formulas.
THE sniper’s ponderous rifle of Civil War days has returned in the form of a super-accurate rifle made by the Winchester Arms Company for the United States Government and used by the 1921 Olympic team in defeating the Swiss riflemen for the first time in a score of years.
Floating Cradle Lays Jointed Pipe across River Bed
BY THE ingenious use of a timber cradle 150 feet long, suspended between two moving barges, engineers recently set new speed records in submerging thousands of feet of flexible joint, 30-inch cast iron pipe under three rivers that cross the route of a 20-mile water supply line running into Norfolk, Va.
FURNITURE manufacturers in Germany have developed an ingenious method of dyeing the wood of living trees instead of waiting until the tree is cut down and sawed into lumber to apply the coloring. A solution of the dyestuff in water is supplied to the roots of the tree through a tube from a tank suspended from the trunk at a height of 10 or 15 feet.
BASED on the principle of the harpoon, a new spring gun for trapping furbearing animals, has been designed by Mr. V. M. Brown, of Medicine Lodge, Kans. The trap includes a barrel in which is mounted a spear that is driven downward by a coiled spring concealed within the barrel.
New Stagecraft Lifts Scenes through Floor and Paints Them with Light
Revolutionary Playhouse-Amphitheater without Aisles Created by Young American Designer
A Stage Suddenly Appears
“Painting by Light”
Source of Light Unseen by Audience
IMAGINE yourself entering a square theater without aisles, and in which the stage, instead of being “framed” like a picture, at one side of the auditorium, juts out from a corner, presenting a wide circular front to the audience. No stage curtains, back drop, or orchestra pit are in sight—just a bare, colorless platform, separated from the spectators only by a low flight of steps.
RIVET-PASSING by compressed air through a flexible metallic hose is replacing the dangerous bucket-and-tongs method.The new apparatus consists of a simple compressed-air gun and storage tank and a metal hose that leads from the forge to the riveter.
THE work of battering and stripping the body of a hard concrete road—always the most difficult part of a road repairing job—has been greatly simplified by the invention of a powerful road-breaking machine mounted on a truck driven by a gasoline engine, and similar in design to the crushers once used in stamping mills to crush quartz and metal ores.
IN A 16-foot combination power and row boat driven by a single cylinder, 2½horsepower engine, Walter P. Horger and Henry J. Miller started from Detroit, Mich., recently on a 4000-mile cruise through the Great Lakes as far as Duluth, Minn., and back.
PAINTING house numbers on the curb where they are in plain sight of automobilists and drivers of delivery cars, is a practice that is becoming popular with residents of Glendale, Calif. The numbers are stenciled on the curb with lampblack and oil and will last for years.
Six-Story Foundation for Apartment House to Hold Garage
How the Problem Was Solved
APARTMENT houses with entrances at the sixth floor, 80 feet above the ground, will soon be constructed in the fashionable Riverside Drive district of New York City to face an elevated cross street that bridges a deep valley and joins the elevated drive at 134th Street.
DO YOU know how strong you are? Run up the stairs as fast as you can— two or three at a time if you like—and have some one note the time in seconds you require to climb a definite height in feet. From these figures, and your weight, including clothes, you can determine your “horsepower” by means of the chart shown below the accompanying illustration.
FINDING millinery less profitable and less interesting than beekeeping, Miss Josephine Whipple, of Los Angeles, Calif., turned professional apiculturess and has recently invented a queen bee capsule, or incubator, in which the queen bee spends the first ten days of her life.
FIVE minutes of candlelight, streaming through a pinhole, is enough to make the slender stems of little mustard seedlings lean over toward the source of the light! To get a glimpse of sunshine, the shoot of a tulip bulb will struggle upward through the dark earth for a distance of 11 inches, and at the end of the climb will have enough reserve energy to spread its leaves and create a flower!
Wing Spars Support Engine of New Loening Monoplane Racer
Tanks Waste Fuel
DEPARTING from the usual “automobile type” of airplane construction—that of supporting the engine, with propeller, on the longerons or longitudinal members of the fuselage, Grover C. Loening, famous young American airplane inventor and designer, has perfected an extraordinary type of racing monoplane in which the wings and the powerful engine they support form a complete flying unit in themselves.
DESIGNED to prevent disastrous train wrecks due to the failure of engineers to observe block signals or their carelessness in taking curves at excessive speed, an automatic train governor, designed by E. Rodolausse, a French engineer, not only makes a train foolproof, but actually keeps an accurate record of a train’s performance by which the engineer’s competency can be judged.
This Raft-Boat Sails against the Wind by Wind Power!
DRIVEN by the power of the wind, yet able to progress against the wind at moderate speed, a small water craft of unique design recently made several successful trial trips on the Seine River, near Paris, navigated by the inventors. The apparent paradox of sailing against the wind by wind power is explained as follows:
Eye-Witness Describes Colossal Cloudburst in a Western Canyon
A Twelve-Foot Sheet of Water
Story of Eye-Witness
Safety in the Hills
John Edwin Hogg
I HAVE just talked with the only eyewitness of the most colossal cloudburst recorded in modern times—with Joe Lacy, a guardian of the Los Angeles water supply aqueduct, whose family fled up the hills from their doomed cabin on the edge of the Mojave Desert, Calif., while a wall of water 60 feet high thundered down the canyon at their heels.
UNCLE SAM will soon own the first “mother ship of the air.” Carrying beneath her huge 300-foot body a brood of speedy bombing and scouting planes that she can release or pick up while traveling at full speed, the “R-l”—first semirigid airship to be built in America— will provide, when completed, an efChief aero engineer of the Goodyear Tire and Rubber Company, in charge of constructing the “R-1.”
Walls of Metal Lath and Plaster Withstand Blaze for an Hour
Homes Protected at Small Cost
New Fireproof Building Material
Fire Buff Gives Advice on Fire Prevention
A Barrier to the Flames
Where Metal Lath Gives Safety
WILL you be one of the 15,000 victims of fires in the United States this year? Will your home be one of the 1600 dwellings offered as unwilling sacrifices to the God of Flames this week? You can’t answer those questions. But, thanks to remarkable progress in the science of fire prevention and fire control, you can help to cut down the $1,500,000 daily toll exacted by preventable fires in this country, and of which you now must pay your share.
This Large Capacity Truck Was Built from a Tractor
CONSTRUCTED by combining a Fordson tractor with the wheels obtained from a large steam tractor and mounting a wooden body on them, a homemade large capacity truck is being used by a contractor of Athens, Ontario, Canada, for the purpose of hauling stone from a crusher and distributing it along a road that is being built.
A MUSICAL instrument built on the principle of a piano, but in which the keys operating the sound-producing mechanism are pressed by the feet of the player, has been invented by a Western musician. The strings of the instrument are mounted on a vertical frame inclosed in a wooden case.
CORNCRIBS that cost little and give good ventilation for ripening and drying the grain, are built of woven wire netting by ingenious farmers in Argentina. The cribs are constructed by driving eight long poles in a circle of 15 or 20 feet. Around these poles sections of wide chicken wire are fastened, allowing each section to overlap.
THE latest bathbrush has in the center of the bristle side a space large enough to hold a cake of soap. The soap is held by a clamp that can be adjusted by a screw on the back of the brush as the soap becomes smaller from use.
THE world’s largest paver, weighing over 30 tons, manufactured by a Milwaukee, Wis., concern, will automatically lay a mile of concrete road pavement in four days. Material is brought to the paver in cars. A derrick on the paver grapples the body of each car, picks it up and deposits its load in a charging skip.
EXTREMELY compact, yet combining the most improved features of a large camera, a pocket camera recently perfected is only a half inch thick when collapsed. It is equipped with a long bellows extension, permitting the photographer to take pictures as near to the objective as a foot and a half.
A COLLAPSIBLE paper umbrella that is serviceable and attractive has recently been designed and patented as an inexpensive emergency shelter for the traveler who is caught in a shower. The umbrella is made of waterproofed paper and consists when open of two cones, the inner one of which acts as a brace (corresponding to the ribs in the ordinary umbrella).
WITH a small and inexpensive home motion picture projector recently devised, any household may enjoy the best movie productions and the most popular film stars without going to the theater. The film reels used with the projector are faithful reproductions of the original feature releases.
Send your questions on subjects of general or applied science to Information Department, POPULAR SCIENCE MONTHLY, 225 West 39th Street, New York City, inclosing self-addressed stamped envelope
A. Because during millions of years the rains have been wearing down the land and carrying the dust and sand from it into the sea. The solid fragments have been deposited as sand or clay on the sea bottom, but always there has been a little of the rock from the land that was really dissolved by the water and remained in solution.
DESIGNED for forest fire patrol and for municipal fire protection, a rotary rear wheel pump attached to a track-laying tractor is performing excellent service. It is adapted also for use by contractors in pumping out flooded excavations, trenches, or coffer dams and as an auxiliary for irrigation work.
It Might Give You a Headache, Says Army Captain Who Describes First Scientific Tests Revealing What Happens When a Bullet Is Shot Straight Upward
Capt. Edward C. Crossman
ON THE shelter platform, above our heads, the Browning machine gun remarked 10 times, staccato: “Tat-tat-tat-tat,” while three s top watches clicked with the first shot, and commenced their busy ticking. Above us two machine gunners ducked under the cover of their extemporized steel shelf, while we stood in security beneath half an inch of armor plate covering the 10-foot-square platform of the observation tower.
Professor Braves Death to Prove Dread Spiders Are Man’s Friends
Induces Huge Tarantula to Bite Him—and Lives!
Taking His Life in His Hands
WOULD you have the nerve deliberately to force a “deadly” tarantula—that dreaded hairy spider often as large as a man’s hand—to nip your finger, in order to test the supposed fatal effects of its poison? Professor W. J. Baerg, a scientist of the University of Arkansas, recently summoned his courage to try just such a daring experiment on himself.
THE invention of a small seaplane that can be stored in a submarine, assembled on the deck in five minutes, and launched, provides a new weapon of attack. The seaplane has a wing spread of only 21 feet. It can be knocked down and stored in a four-foot hold of a submarine.
How Marvelous Switchboard Instruments Locate the Exact Spots where Wires Break and Poles Fall under Tons of Ice—Our Voices Take a Detour while Army of Workmen Rushes Repairs
Switchboard a Block Long
Where Trouble Is Spotted
Wheatstone Bridge Finds Breaks
Trouble Army Mobilizes
Some Famous Storms
Harry A. Mount
WHEN sleet and ice turn the world into a glittering fairyland, and telephone lines go down under the weight of the frosty tinsel, there swiftly comes to the aid of American telephone companies an amazingly sensitive, almost human, mechanism, that immediately puts its finger on the breaks and skilfully directs the work of repair so that our telephone communications may be uninterrupted by the winter storm.
A ONE-WHEEL, hand-pushed cycle, the wheel of which incloses a cylindrical container, has recently been placed on the market for transporting bulky books and documents, or as a handy, practical substitute for the housewife’s market basket.
WHEN you press the edge of a calling card on the top of a steel bar 4 ½ inches thick and 20 inches long, solidly supported at both ends, will the bar bend? It certainly will, improbable as it may seem. In fact, with a homemade apparatus, you yourself can easily measure the deflection, which is about a millionth of an inch!
NIGHT flying over transcontinental air routes is expected by government officials within the next six or eight months, making it possible to shoot mail through the air from New York to San Francisco within 28 or 30 hours, thus reducing delivery time by four days.
COMPLETELY submerged, horizontal paddle wheels, so mounted that they can be used as rudders, have recently been introduced by a French company for canal barges and other craft using artificial waterways. In the past, navigation of barge canals has been hindered and their usefulness destroyed by the churning of vertically working turbines and paddles.
PRESSED by the increasing need for additional parking space for automobiles, the city of Cleveland, Ohio, is planning to install the first underground municipal garage. Cleveland’s lead probably will be followed in New York City. Cleveland possesses an ideal site for underground parking—an expansive mall or open public park, about which is being built a group of great public buildings, all of Roman architecture.
Electric Loom Weaves Elaborate Designs from Metal Photos
Why Linen Is Expensive
ANY home, club or hotel may now own linen and other fabrics of individual design at reasonable cost as the result of an invention by Dr. T. A. B. Carver, of Belfast, Ireland. He has devised an electrical loom that makes use of metal photographs and electrical currents in transferring the artist’s original design directly to the automatic weaving mechanism.
THE practicability of general public use of telephone wires as radio aerials is being demonstrated in the state of Washington, where the Seattle Radio Association—a broadcasting enterprise—and the Puget Sound Telephone Company have entered an agreement by which any telephone subscriber, using a newly invented adapter, may convert phone lines into an aerial for his receiving set.
BY WELDING together several lengths of rail and laying the long sections so formed, a street railway company of Washington, D. C., found it possible to replace tracks on an entire line without interrupting traffic. The work of welding the rail lengths was accomplished during the daytime when traffic was heavy.
A NEW “track laying” tractor, the entire weight of which travels on anti-friction rollers, has been designed to minimize wear and “knocks.” Advantages claimed are: that it covers a wide range of duty without change of cleats; that its self-cleaning cleats do not fill with earth; that it increases the amount of motive power delivered to the drawbar, and that it makes shorter turning possible.
How an Inventor, by ingeniously Combining Blue-Green and Red-Orange on Double Photograph, Tricks Our Eyes into Seeing Delicate Shades of All Colors, Vividly Representing Life
A Colorful Dream Comes True
Light Rays Split and Filtered in New Color Camera
A College Professor's Vision
How Our Eyes Mix Colors
Facts Explaining How We See Color and How Color Screens Work
Green Isn’t Green
WHEN I was told, a few weeks ago, that another new process for taking motion pictures in color had been “perfected,” I confess I smiled skeptically to myself. I had seen many colored movies before. They had left me either unimpressed or thoroughly displeased.
SERVING as a memory jogger for the business man, a reminder clock, recently perfected, rings an alarm when the hour for an appointment arrives. The rim of the dial has 48 slots into which small cards can be inserted. Each of these slots with card inserted, controls the alarms for a quarter-hour interval.
A MAMMOTH self-propelled floating crane, capable of lifting loads of 150 tons, is the recent contribution to the list of giant engineering equipments, by a Dutch engineer and shipbuilder, Mr. Werf Gusto. The crane, of the derrick type, is provided with two sets of tackle, from each of which loads can be deposited upon the deck of the hull on which the crane is supported.
BY REPEATEDLY dropping a typical truck wheel to the pavement from any desired height, a new portable electric road-impact machine, now used by the United States Department of Agriculture to test concrete slabs, subjects the concrete in a few hours to wear and tear as great as that produced by driving a truck over a pavement for months.
AN ELECTRIC massage apparatus that enables the operator to massage the entire body of a patient in a few minutes consists of a series of eccentrically mounted rollers on a shaft driven by means of a chain from an electric motor. The rotating of the shaft causes the eccentric rollers to knead the body over an area equal in width to the length of the shaft, or about 1½ feet.
FURTHER development of the gas mask has resulted in a new breathing apparatus for rescue work, recently perfected for the navy by the United States Bureau of Mines. The mask enables the wearer to remain under water for 15 minutes. It consists of a rubber breathing bag in which oxygen, escaping from a tank, is mixed with air from the outside.
WHILE it has been comparatively simple for engineers to design economically an arched bridge to cross a stream at right angles, there has been considerable difference of opinion regarding the correct design of a skew-arch bridge (one that crosses a stream or road diagonally).
DRIVEN by four surface propellers, and designed to skim over the top of the water, a sea sled, built for use as a passenger boat on the Magdalena River, Colombia, S. A., recently developed a speed of 30 miles an hour carrying a load of 51 passengers up the Connecticut River.
ONE person in every 300 wears a glass eye! When you consider that you may pass hundreds, or even thousands of persons a day, without observing one case of sightlessness, this astonishing estimate, coming as it does from reliable manufacturers, is convincing evidence of the perfection reached by skilful modern artisans in duplicating the shape, size, and color of human eyes.
AFTER years of experiment by various manufacturers of farm implements, a combined potato digger and loader has been perfected in which a steel blade, passing under the tubers, lifts them upon a movable open slat conveyor. There the loose dirt and small potatoes are sifted out and the valuable potatoes are carried to a wagon that moves alongside of the machine.
SERVICE and clever advertising are combined in a fence built on the premises of a garage near Glendale, Calif. The enterprising owner has used worn-out tires for this unique barrier. The tires are nailed to a horizontal bar supported by posts in such a way that they overlap, thus forming a complete barrier.
WITH stitches concealed so that they are not exposed to direct contact with pulleys, a belt splice recently patented makes it possible to join small belting, such as is used on an auto fan, so that the splice lasts. The belting is cut so that one end will have tongues of unequal length that exactly fit into slits cut in the other end.
COMPRESSED air is used in a new apparatus for baling empty cement bags. The device also serves to bale other materials. A hundred or more bags are placed beneath the ram, a lever is pulled, and the bags are instantly ready in a compact package.
A “STROKE counter” has recently been placed on the market for the convenience of golf players who find it difficult to keep mental track of the number of strokes they require to make a hole. In match games an official scorer is provided, but even then a player likes to keep his own record.
TRADESMEN can save money by printing their own display signs artistically and rapidly with the aid of a new lettering outfit manufactured by a concern in Westport, Conn. No special skill in lettering is required to use the device. The apparatus consists of 30 frames, each having a different type of lettering.
A PERSONAL filing cabinet recently placed on the market by a New York manufacturer, weighs only 72 ounces without the index, but being of rolled steel, it is fireproof and can stand such abuse as it would receive in transportation. The drop front makes easy the removal of any paper, no matter how full the file may be.
AN ATTEMPT is now being made by the government to discover new sources of platinum, nickel, tin, vanadium, tungsten, cobalt, antimony, chromite, and zirconium—minerals that exist in this country only in inadequate amounts or are entirely lacking.
AN AIR preheater for house furnaces that utilizes the principle of the blast furnace and thereby, it is claimed, provides a fuel saving of at least 20 per cent, is being marketed by a concern in Richmond, Ind. It has been proved that the greatest heat in a furnace is in the coal bed.
DIFFICULTIES of cranking the balky engine of a motor truck, especially in cold weather, may be overcome by the use of a newly invented cranking machine driven by compressed air and mounted on a small truck. The drive shaft of the machine, with universal joint, engages the crankshaft of the truck by means of a clutch.
A SELF heating soldering iron, recently brought to this country, has a receptacle with a hinged cover into which a capsule containing a combustible material is placed. A special match is inserted in the top of this capsule or briquet and the wooden part of the match is broken off.
Shaking Motion Moves Ore along Stationary Conveyor
AN ELECTRICALLY driven stationary ore conveyor, that carries the ore forward by a shaking motion, consists of a metal trough operated by an electric motor. In addition, an upward motion is imparted by a curved track on which the trough rides.
Using Cement Horn with Radio Amplifier, Inventor Floods Miles of Countryside with Melody, Giving Entire Rural Community Unique Entertainment
An Idyllic Community Center
How the Phonograph Is Utilized
YOU are driving your car along a country road in a prosperous farming community not far from a large city. Suddenly you hear a faint, barely audible melody floating through the air like the strains from some elfin orchestra. At first you are startled.
A COLLEGE education for every one who wants it. A university in the home, in the factory and mill, and in the public hall. An “aerial soapbox” for the forces of economic progress and right. A complete course in practically any of the subjects now named in the college curriculum—for five dollars; an elementary course in these subjects for one dollar, and a single, far-reaching lecture on one of them by a worldwide authority for ten cents.
Fourth Series: Two Big Problems of the Moment—The Loudspeaker and Radio Frequency
1. Know Your Loudspeaker
2. Know Your Radio Transformer
Two Tubes Do the Work of Four
3. Place Your Trust in Short Leads
4. Make Tuning Elements Simple
Various Ways to Hook Up Your Radio Frequency Set
5. Trust the Potentiometer
6. Use a Battery Switch
7. Use a Loop wherever Possible
8. Use Only Hard Tubes
9. Transfer Tubes in the Circuit
10. Regeneration and Radio Amplification
THE long-distance bug has bitten the radio fan, inoculating him with the desire to hear what the broadcasting stations across the continent have to say. How can this long distance be achieved? Undoubtedly the best way is by the use of radio frequency amplification, and it is my purpose this month to guide the radio fan in its use.
Important Facts about Tread and Fabric that Will Help You Cut the Cost of Driving Your Car in Winter
The Ten Parts of an Automobile Tire
How to Avoid Blowouts
Why Well Built Tires Cost Less in the End
Protect the Tube
Know Your Car
Harold F. Blanchard
WINTER is the time when tires suffer most. Sharp pieces of ice cut and tear the tread, while icy ruts rip the side walls to shreds. Pieces of ice are picked up by the tire, and later, when the car is in a warm garage, the ice turns to water that rots the tire structure.
MOST automobile drivers have observed that differential noises are periodic. For several months, perhaps, a well-oiled housing will develop a roaring noise that can not be located; then suddenly, for some unknown reason, the noise will cease.
AUTOMOBILE tourists and those who drive frequently on country roads at night will find a searchlight mounted on the right-hand runningboard of the car, as shown, a great help in staying on the road. It lights up the margin of the road and shows where the ditch lies.
A GASOLINE separator that will remove both sediment and water, can be made easily by following directions and illustration below. No dimensions are given, because the size of the separator will depend entirely upon the size of the engine.
LEAKAGE at pump stuffing boxes and hose connections, which will open up when the car is operating on the road, often are not in evidence when the machine is stationary, and it is difficult to determine where the leaks are unless pressure is applied to the motor.
EVEN the most careful job of repainting a car sometimes lacks a finished appearance because it has no striping. To add the stripes, the colors desired should be mixed to a rather stiff consistency. They should be thin enough to flow readily from the brush and yet be stiff enough to stay where put.
JUST as machines have taken much of the drudgery from large shops, cheap electric power and sturdy and inexpensive small motors make it possible to eliminate tedious hand work from the home workshop. By motorizing his shop, the home worker can quickly repay the cost of installation through increased production and better and more accurate work.
TO BE able to design and apply stencils is a most valuable accomplishment for the home worker, and one worth mastering. Stencils can be used for ornamenting many kinds of painted, enameled, and stained work, and will serve alike for decorating small pieces of furniture and large plaster or wallboard surfaces.
THRILLING and yet comparatively safe is the new winter sport of bicycling on the ice. The machine is equipped with skis and a jibsail, so that it is really a high speed scooter. Three or four machines make possible 10or 20mile races around a one-mile circular track.
OF ALL factors that determine the success or failure of the mechanic, especially the machinist, that of accurate measurements is the most important. In large manufacturing plants, where interchangeable parts are produced, the demand for accuracy is met largely in the toolroom by expert design and workmanship in jigs, fixtures, and gages and ordinary meth ods of measuring are scrapped almost entirely.
TWO advantages distinguish the type of trestle illustrated from those usually seen in shops where heavy loads have to be supported. The legs are so spaced that they are not opposite each other and the trestles therefore will nest together.
IN A certain plant manufacturing cream separators there is considerable soldering to be done, and to speed up the work the scheme illustrated was devised. Its simplicity is its chief advantage. The gas heated iron formerly used was discarded and an electric iron substituted.
ON JIG and fixture work I often use the quick acting nut illustrated. It is a great time saver and does not take as long to make as many another locking device. To tighten or loosen this nut, it is necessary to give it only a quarter turn and it then can be lifted off.
Battery Repair Table Revolves on Repairman’s Bench
E. L. F.
A REVOLVING table is a useful addition to the battery repairman’s bench. By being able to turn the battery in any position, the repair work is considerably simplified, especially such operations as soldering terminals and “pitching” shut the jars.
EVERY practical tool user and all of our readers who are interested in inventions or in patents on new tools, or improvements on old tools, will find illuminating a recent experience of POPULAR SCIENCE MONTHLY. On page 92 of our December, 1922, issue, a contributor described a planer gage with several useful features, constituting an improvement on gages of this type commonly in use.
Dual Toolposts Will Speed Up Production of Bushings
G. A. LUERS
TO INCREASE production in bushing work or in turning parts of the general shape of a bushing, the lathe tool mounting illustrated is an expedient of value. The work is accomplished with a single tool set-up and only the stock and steady rest are moved to repeat the operation after one bushing is finished.
THE feature of this bench lathe boring-tool holder lies in the ease with which the tool may be raised or lowered to the center of the work. The parts of the holder and the method of assembling them are made clear in the illustration. The tool is quickly made up and will repay the labor required many times over for any machinist who does fine work on a bench lathe.
GALVANIZING is a processs by which zinc is deposited upon another metal, usually iron. Because zinc furnishes an almost perfect protection from rust, it is widely used as a coating for iron and steel hardware, wire products, screws, nuts, bolts, and similar articles.
FOR some years I have been interested in small bench lathes. Until recently the method of testing was as follows: The test bar was inserted in the bearings and locked by screws in the bearing caps and a block with a V edge to correspond to the shears of the bed (front side) was used with a dial indicating gage.
AFTER masteiing his homemade receiving set, the radio fan invariably wishes for a suitable cabinet. He wants something that will be as permanent and beautiful a piece of furniture as a cabinet phonograph. There are many styles of cabinets that can be built at home, ranging from the simple boxlike case described in the Home Workshop last May, to the elaborate inlaid cabinet that is illustrated above.
WHEN the natural setting permits, skating parties can be enlivened by arranging an overhead trolley for what might be called ice flying. One skater at a time skates rapidly toward the pulley bar, as illustrated, grasps the handle and coasts as far up the wire as possible, and then turns in midair, so that as he travels back to the starting point, he will be ready to release the bar and resume skating.
TO THE lover of flowers this miniature greenhouse will make instant appeal. It is not only easy to make and attractive in appearance, but also, with its aid, the most delicate plants can be kept in the window garden successfully. Even orchids, those fairylike flowers, do well in this greenhouse, and other plants, like ferns and palms, develop prolifically.
THOSE who like to sleep with the windows wide open or are forced to do so because of illness, find that many disadvantages are involved. Rooms get so cold that it is most uncomfortable to dress in the morning, hot water heating systems freeze, and there is a considerable waste of coal in heating up the room for daytime use.
HAVING lost two valuable bunches of keys by having the clip work off the belt, I set out to design a clip that would not come off and yet would be convenient to use. Finally I hit upon this clip. I took an ordinary clip, A, cut off one end, and bent it around a small harness snap, B. Then I bent the other end to fit over the belt, as at C. The belt must be threaded in the slot.
A UNIQUE and useful automatic match safe may easily be made by following the details in the accompanying illustration. Any kind of wood may be used, either hard wood, such as oak, maple, and birch; or soft wood, such as mahogany, poplar, and white pine.
THE home mechanic often is obliged to find the pitch of internal threads in small tubes, machine parts, and fixtures of one kind and another. The ordinary external thread gage of the leaf type is of no assistance in cases when the leaf is too large to enter the threaded bore.
Billy and Fido Toy Illustrates a Mother Hubbard Tale
Charles L. Miller
OLD Mother Hubbard, on one of her many returns to her cottage, found her dog riding the goat and this toy illustrates that tale. The general arrangement is shown in Fig. 1. As the car is drawn along, a cam causes the goat to buck up and down, but the dog always maintains his balance.
Resistance Unit for Recharging Radio Storage Battery
J. M. Rolston
A PORTABLE resistance unit, like the one illustrated, for charging radio storage batteries from any direct current lighting socket permits the owner to draw six amperes without using a cumbersome bank of lamps. The construction is exceedingly simple and inexpensive because standard parts are used.
Radio Receiving Set Operates on 110-Volt Direct Current
TO THE majority of radio experimenters, audion receiving sets spell storage batteries, which are always expensive and must be charged frequently. The wireless fan who has spilled acid from his battery on a rug and has found it necessary to buy B batteries frequently, can avoid all his difficulties if he has access to 110-volt direct current mains, for he can build a receiver to operate entirely from them.
THIS collapsible display rack, installed in a Washington, D. C., store, is of especial interest because of the manner in which the arms fold out of the way when not in use so that one or more may be used independently of the others. The construction is simple and inexpensive.
THE past few decades have seen an amazing development in the manu facture of lenses suitable for the compound microscope. But since such an instrument is expensive and often is employed only in photographing objects too small to be seen readily with the eye, a different method, requiring only one well ground lens for both enlarging and photographing, will frequently serve satisfactorily.
I ALWAYS have had a shop in which to putter and tinker at making things, and when I needed money to build a wireless set, I turned to my tools to help me earn it. I found a demand for some one who would do little things that didn’t require a carpenter—placing an extra bolt on a door, making a sidewalk, building and repairing fences, placing a board on a porch floor, and similar jobs.
OFTEN wire, such as copper-plated spring wire and piano wire, which come from the factory in coils, must be straightened before it is used. A way to do this easily and quickly is by drawing the wire off the coil through three nails driven in a block of hard wood.
Test Lamp Prevents Burning Out Costly Vacuum Tubes
EVERY radio fan who experiments with new circuits can avoid the danger of burning out an expensive vacuum tube through short circuits if he will make it a practice to test the filament terminals of all sockets with an ordinary electric light bulb of the same voltage as the vacuum tube.
ANY one who has tried to saw slots in a midget phonograph record or a piece of a large record in order to make spider web inductances for a radio set, knows that it is next to impossible to avoid breaking the brittle composition. The work can be done easily, however, if two ½-in.
MANY postcard projectors show the pictures backward, with the printing reading from right to left, although some of the higher-priced machines use a prism and refracting lens to correct this fault. You may make a projector having this advantage, however, without using a prism and at very little expense.
OFTEN when the home mechanic wants to make a picture frame or other mitered frame, he has no miter box handy and doesn’t wish to go to the trouble of making one. He can make perfect fitting corners, however, simply by laying out on the workbench or table the outline of the outside dimensions of the proposed frame, as shown.
Box for Feeding Birds in Winter Turns with the Wind
Robert Page Lincoln
TO ENCOURAGE the winter birds in the colder sections of the country, many persons scatter crumbs or seeds on the ground, after clearing away the snow. This is not the best method, because driving snow frequently covers the food just at the time when it is most needed.
A THOROUGHLY reliable method of making a set line rig for fishing through ice for pike, muskalonge and other large fish, requires nothing more than a stick and crotch. The crotch is large or small, depending upon the amount of line to be used. A hole is bored near the top of the handle and the line is pulled through, brought down to the crotch, slipped under and then wound over one arm and under the other.
Electric Timer in Darkroom Aids Amateur Photographer
H. C. McKay
IN ALL darkroom work the amateur photographer feels the need for some method of accurately counting time. Consulting a watch or guessing at the time are equally unsatisfactory. The ideal way is to make a simple audible counter. The materials required are a common advertising yardstick, a 6-in. length of light clockspring, a wooden block 1 by 3 by 3 in., some tinner’s lead or babbitt, wire, batteries, a large nail or spike and an electric bell.
AMATEUR mechanics like the writer are often put to it to find room for their tools and equipment, especially in the constricted space of a flat. While an old table in the corner of a bedroom has done duty as a bench, it was a problem to make a place for a diminutive lathe that was added to the outfit.
Motorized Workshop Saves Time in Making Plant Repairs
A PORTABLE bench with a self-contained power plant is used in one large factory so that small construction or repair jobs can be done with the least delay. To obtain power, it is necessary only to screw a plug into the nearest lamp socket. The heavy, rugged bench has a lower shelf to support the motor and a line of shafting.
THREE large connecting rods from an old engine were utilized by a Washington, D. C., mechanic for supporting a line shaft that was to drive a series of small bench machines from a 1-hp. electric motor. The 1-in. shaft extends for 15 ft. across the shop and improvised hangers are placed at 5-ft. intervals.
SKATES form the runners of this little ice boat, which will furnish endless fun for the skilful boy on frozen ponds and streams. The rider lies flat on the plank and operates the tiller with his hands. The sail is manipulated by means of the wire loop at the end of the boom, which is slipped over either ankle.
Sheet Metal Parts Will Replace Broken Furnace Castings
L. N. O.
FREQUENTLY some casting connected with the furnace breaks. Regulator links, draft door controls, and parts operating grates are brittle and easily damaged. These parts can often be replaced quickly and inexpensively with sheet metal fittings.
Carved Strips Transform Cigar Box into Jewelry Case
ORNAMENTAL carving of the simplest kind will transform an almost square cigar box into the jewel case illustrated. The carving is done on strips taken from another cigar box, some of the strips being l in. and others in. wide. Each of the strips is then notched along its two upper sides with a pocket knife, care being taken to space the notches equally as to depth and width.
THE difficulty of keeping the windshield clear in a rain or snow storm can be overcome by washing it with a mixture of one part kerosene and one part glycerin shaken well together. The kerosene acts as a cleanser and the glycerin as a coating over the glass, from which the moisture will run without blurring the driver’s vision.
IF YOU should be unfortunate enough to break your favorite pitcher or one of great-grandmother’s plates, don’t fail to pick up the pieces. To cement them together you can use nothing better than ordinary white lead, according to comparative tests made by the Department of Agriculture.
Cement with Waterproof Coating Forms Durable Drainboard
A KITCHEN sink drainboard that costs little and will stand up under constant washing with boiling water and lye can be made of cement plaster on metal lath. The hard surface finish is given with coatings of commercial waterproofing finishes, which are easily obtained and quite inexpensive.
TIME and use play havoc with the appearance of the leather covering of a kodak. The writer endeavored to refinish one with a prepared “camera finish,” but found that the slightest moisture caused it to crock and rub off, and a touch of water would wash it off entirely.
TARNISHED silverware can be cleaned by dipping it in a solution of water, soda and salt in an aluminum pan. There are several methods of procedure, but the simplest is to fill an aluminum pan that is clean and free from grease with sufficient boiling water to cover the silverware.