# Popular Mechanics/Volume 50/Issue 5/The Latest Submarine Life-Saver

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Diver Getting His Breath Preparatory to Another Descent, and a Close View of the Improved Breathing Mask
Two men recently spent a quiet afternoon diving into a great tank at the navy yard, Washington. They wore bathing suits and on their heads was a curious-looking device not unlike an ordinary gunny sack with a rubber tube attached to the wearer's mouth.
First one man would disappear slowly beneath the surface. His every move was visible to the few spectators above, for the water was absolutely clear. Treading water, he would find the bottom and then, by means of some magic powers attached to the head device, he would remain down there, may be half an hour, possibly longer. Safe on the surface once more, he would watch similar maneuvers of his companion diver.
Since the apparatus is so built as to work efficiently only from the bottom up, rather than from the surface down, it was necessary to inclose the diver's head into a device looking like an inverted half of a barrel. It served the purpose of entrapping a substantial quantity of air, thus permitting quick descent.
Extremely simple as those diving operations appeared to be, they meant much to ​humanity—the possibility of avoiding loss of life in submarine disasters.
First Stage in Descent with the Diving Bell; Diver Climbing Inside for Lowering
Close View of the Bell That Aided in Rapid Descents during Breathing-Mask Tests by the Navy; Note Air Hose and Connection
The two divers are counted among America's best-known experts on submarine life-saving devices—Lieut. C. B. Momsen and Chief Gunner C. L. Tibbals. For six months they had been working night and day on the breathing device they had invented in conjunction with F. M. Hobson, civilian engineer in the naval bureau of construction.
Following the tank tests in sixty feet of water, the experts took their apparatus a few miles down the historic Potomac, recently choked with mud through flood. Instead of the inverted barrel, an especially rigged up diving bell, weighing about 1,500 pounds, was employed to convey the diver to the bottom. During the descent, he was located within the bell in such fashion that, while standing on a platform, his head was inside a bubble of air. Slowly he was lowered, his system meantime becoming gradually accustomed to the steadily increasing pressure until he reached the bottom, 110 feet below the surface.
Fundamentally, the apparatus has all the essential characteristics of standard European life-saving apparatus, but the new navy device weighs only two pounds—many times lighter than others of its kind, which range around twenty-one pounds. Then, too, the rebreather is small, about eight by ten inches.
Lieutenant Momsen, one of the inventors of the newcomer, gives a graphic description of its operation on the scene of actual disaster. "There are two ways," he explains, "whereby it may be used to advantage. First of all, when no help seems to be at hand and the crew of ​the wrecked submarine must brave the treacherous depths alone; and secondly, when a diver has descended, ready to give aid. In the first case, it will take the men only a few seconds to don the apparatus.
"At this point one might well inquire, how in the world the men will be able to withstand the terrific pressure that prevails at 200 to 300 feet. Here is the answer: Under normal atmospheric conditions we all are under a pressure something like 14.7 pounds. Down around 200 feet the pressure jumps to 88 pounds, Certainly that is a terrific force to beat against a man's body. But after all, it is a relative matter, since pressure conditions become equalized all over the body.
"Nor should we forget that nature has equipped us all with a remarkably devised pressure resistor, the Eustachian tube, a tiny structure running from the mouth to the ears. So, with the aid of that and the new device, the men in a sunken submarine should be able to gain the surface without experiencing that terrific pull on the eardrums which some times spells death to a diver. All the while, of course, there is no heavy weight to hold the men down and, when they have stepped outside the wrecked craft, the buoyancy of their bodies will hurtle them to the top. Once there, granted that other human beings are fairly close by, their lives should be saved.
"Of course, a somewhat different situation exists when the crew of the submarine happens to have an expert diver from above come to their aid. In such case, the submarine's commander may send the men out of the wrecked craft one at a time. Thereupon the diver, being attached to a strong rope, need merely signal to his helpers up above, and the two men will reach the top quickly. Another diver will then go down and the procedure be continued until every man is saved.
"However, the chief point to emphasize in the new instrument lies in the fact that it enables life-saving operations to be conducted and completed without the slightest interference with salvage maneuvers. Once the crew has reached the surface, the submarine commander may aid materially in salvaging his craft."
EAST AND WEST MEET IN AUTO CARVED FOR BRIDAL USE
Oriental splendor and tradition ride on a modern motor car in an elaborate chassis carved for bridal processions in Shanghai. Rich decorations, an ornate chair, hangings and tassels of silk, with other trinkets, feature the vehicle, which is a motorized duplicate of carriages used in China when the bridal party parades abroad.
Elaborate Motor Car Designed for Chinese Bridal Processions; Its Ornate Carvings Conform to Old Oriental Traditions
RADIO GUIDES "PHANTOM" SHIP SAILING WITHOUT CREW
Radio control of ships has been further demonstrated in Germany with the directing of the "Zaehringen," an 11,000-ton vessel, through complicated maneuvers without the aid of a single person on board. The ship's only point of contact with the outside world is its antennae, the wireless orders being sent from a mother ship some distance away. The "Zaehringen" started, stopped, slowed up and changed its course wholly by radio control. Besides these performances, an interesting series of other functions can be executed by wireless direction, for instance, if the oil burners should cause a fire. By radio, automatically governed extinguishers can be put into action and, should the oil-feeding apparatus break down and the ship stop, rockets are automatically fired off to signal the operators on the mother ship that something has gone wrong.
THREE-MILLION-DOLLAR DAM TO RECLAIM DESERT
Constructed to Withstand Severe Strains; the Multiple-Dome Coolidge Dam across the Gila River, near Phoenix, Ariz.; It Has Been Built at a Cost of Almost $3,500,000
Work on the Coolidge dam across the Gila river not far from Phoenix, Ariz., is rapidly nearing completion and engineers are studying it with special interest because of its form of construction. It is of what is known as the multiple-dome type and is said to be the largest of this kind in the world. The buttresslike form is intended to give greater strength. The dam has been built by the United States reclamation service and the Indian department at a cost of approximately $3,500,000.
TELEVISION INVENTOR PLANS FULL-SIZE PROJECTION
Projection of television images on a large screen, in the same manner in which movies are shown, is planned by C. Francis Jenkins, televisor and radio-movie inventor. If the method on which he is working succeeds, the chief problem of television reception—the smallness of the image possible with all existing systems—will be solved. In the old Jenkins process, as in all others, a scanner is used to reproduce the picture. The Jenkins scanner had forty-eight holes, drawing forty-eight successive lines of light, and, as the picture is square, the effect is of forty-eight times forty-eight dots, or a total of 2,304 separate units. Behind the scanner disk is a neon light, the intensity of which is controlled by the received signal, and the illusion of a picture depends on the persistence of vision in the eye, the light of each line lingering until all of them have painted a complete picture. In his new system Jenkins is using 2,304 small incandescent flashlight lamps, mounted closely together in a square bank. A revolving switch or commutator connects the lamps successively to the radio set to receive the incoming signals. But, unlike the neon light, the filament of the incandescent lamps continues to glow for an instant after the current is turned off.
​Thus the background does not merely appear to be bright, but actually is bright, though the glow from the lamps which have been turned off is not bright enough to detract from the light of those that are in circuit to form the picture. The net effect, however, is a much larger picture with infinitely more light than a neon lamp can produce, so it is possible to place a condensing lens in front of the lamp bank and project the picture on a screen. Jenkins is trying a similar system at the transmitting end, with 2,304 small photo-electric cells on which the image, focused by a lens, will fall.
HOW CROCODILES ARE HATCHED REVEALED BY PHOTOS
Just Emerging from the Shell, a Baby Crocodile Surveys the World and the Camera
Interesting stages in the hatching of crocodiles have been obtained by photography by training a camera on a number of eggs that were taken from a Java river bank and hatched in a laboratory under favorable conditions. One of the remarkable features of the young reptiles is their great development as they leave the shell, one specimen showing the naturally savage tendencies of the species by opening its jaws when a finger was moved close to it.
PUNCTURE MAT TO STOP CARS HELPS FOIL BANDITS
Puncture Trap That Can Be Quickly Extended across the Road to Halt Cars; Pressing a Button Releases the Rack
Stop your car or puncture your tires, is the forcible warning behind a mat of sharp spikes that can be spread across the road at a moment's notice to halt bandits traveling in automobiles or drivers of stolen cars. A press of a button expels the mat from its holder at the side of the street.
VESUVIUS ON VERGE OF NEW OUTBREAK OF LAVA
Mount Vesuvius, the world's most famous volcano, is approaching a new eruption, according to Professor Malladra, who operates the observatory on the mountain slope. The mountain's outbreaks occur from twenty to thirty years apart, and, as the last one of any size was in 1906, another is just about due. The conditions which give warning of an approaching eruption are the failure of springs around the mountain, a series of earthquake shocks, and the filling of the volcano crater with lava. The crater has been practically full since 1926, but the other two manifestations of approaching activity have not yet appeared. In each major eruption the stored-up energy in the mountain blows out the lava which clogs the crater and clears the volcano's throat, so it can "breathe" easier. Then the crater clogs up again and the process continues until the collected lava closes most of the vent and backs up pressure enough to cause another outbreak.
ELECTRIC SHOE-SHINING STAND HAS SCREEN FOR WOMEN
Using the Electric Shoe-Shining Stand with Protecting Shield for Women
Equipped with a shield in front and a motor-driven brush, a shoe-shining stand now on the market is especially designed for women patrons. The operator's stool is a separate unit and carries the motor underneath. The customer's chair is easily mounted, has a comfortable seat and back, and as entrance is gained from the side, there is no danger of catching the clothing on protruding parts. The electric brush, it is said, produces a higher degree of polish than can ordinarily be obtained with the usual hand tools and, of course, also saves time.
OFFICE-PIN HOLDER SAVES TIME AND PROTECTS FINGERS
Waste of time, pricked fingers, and other unpleasant features, are avoided in a special holder for office pins. It has a top so arranged that when it is pressed, a pin emerges bead first from a little opening where it can be grasped with the thumb and forefinger, ready for immediate use. The container holds 200 pins, is attractively finished and does not spill the pins, as they come in special refill tubes ready for insertion in the holder.
EIGHT-MILE RAILROAD TUNNEL BREAKS RECORDS
An eight-mile tunnel through the Cascade mountains, the longest bore in America and fifth longest in all the world, is nearing completion in the northwest. When trains start through it, probably about the first of the new year, the Great Northern's route to the coast will be shortened by many miles, the climb over the mountains reduced 505 feet, a two-and-a-half-mile tunnel abandoned, and six miles of costly snowsheds eliminated. The new tunnel is to cost $10,000,000, but the saving on upkeep of snow and avalanche sheds alone is expected to pay for it. When President Coolidge, on May 1, pressed a telegraph key in Washington and set off the blast that holed through the pioneer bore alongside the big tunnel, he marked the beginning of the end, after two and a half years of labor. The pioneer bore is a smaller shaft, parallel to and sixty feet distant from the big one. It cost several millions to drive the preliminary tunnel, but the savings it made possible made the outlay worth while. Only two gangs, one starting at each end, can work at one time in a single tunnel, but by rushing the smaller bore through the mountains for eight miles, the engineers were enabled to drive short connecting shafts sidewise to the line of the big bore, and then start additional crews from each shaft, working in either direction. In this way the main tunnel was attacked from eight different places, the two outer portals and six in the mountain, with two crews working in each direction from the six, or a total of fourteen crews working at one time. Seventeen and a half miles of the present railroad line will be eliminated, along with the old tunnel and the 505-foot climb to its level. The new bore eliminates also track curves that are equivalent to nearly seven complete circles.
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AMERICA'S LONGEST TUNNEL NEARING COMPLETION
Cross Section of the Cascades. Showing the New Tunnel 500 Feet Below the Present Railroad Line: Photograph of the Range under Which the Big Bore Passes, and, in Circle, One of the Compressed-Air Shovels That Works in Limited Quarters to Clear Away the Rock
DIVING PLANE FOR BOMBING CARRIES FOUR GUNS
Examining Big Bomb on the Fighting Plane, Which Also Carries Four Machine Guns and a Crew of Two
Tests with one of the fastest fighters of the skies were conducted at Mitchell field recently when pilots rode a diving bombing plane through varied maneuvers. This ship, which is equipped with a "Wasp" motor, is capable of a speed of 170 miles an hour and can dive at a rate of 300 miles an hour. Besides four machine guns, it carries a big bomb under the motor and is manned by a crew of two.
CAMERA RECORDS ITS LOCATION ANYWHERE ON EARTH
Accurately recording its position on the earth at the point where the picture was snapped, a sextant camera that has been included in Commander Byrd's equipment for the South Pole adventure, is expected to prove of great service to all navigators by sea, land or air. With one motion, the user can determine his position, whereas, for centuries, a number of instruments and more or less elaborate calculations have been required. It will function even when no ground markings are in sight, and the picture will also show the exact time at which it was taken, the day of the month and the angle at which the exposure was made. This remarkable camera was developed by Comm. M. R. Pierce of the United States navy in co-operation with the Eastman Kodak company. It takes pictures of the sun, and one of the secrets of its operation lies in its ability to "fold and wrap light into a small package." The finished photo is smaller than the hand, 100 pictures can be made on one roll of film, and as each exposure is made, it is cut out and deposited in a dark box. The various recording instruments are housed inside the camera, and the light beams are brought into focus on the film, where they record the data essential for determining the exact position of the camera at the time.
PHONOGRAPH IN WATCH CASE PROVES ACTRESS' VOICE
Practical use is claimed for a tiny phonograph that fits into a watch case and is operated by a small spring. Its records will hold about fifteen spoken words, and these can be reproduced by the owner to show the quality of her voice as reproduced for the talking films. The entire outfit can be carried in a vanity bag.
Gwen Lee Demonstrating the Watch-Case Phonograph, Which Plays a Record af Her Voice
CIRCUS STAGED WITH PUPPETS ATTRACTS CROWDS
Where Puppet Clowns and Actors Present an Eight-Ring Circus; Views of the Elaborate Motor-Driven Arena and the Entrance
One of the most attractive features of an eastern amusement park is a miniature eight-ring circus, in which all the performers are puppets that go through realistic movements by the action of electricity. A tiny band wagon furnishes the music, while midget animals, jugglers and acrobats perform, roller coasters, merry-go-rounds and aeroplane swings operate, and practically all the lively thrills of a real circus are duplicated in miniature. The elaborate installation is the result of a country merchant's plan to attract customers to his show windows. Trade was dull, so he exhibited a few manikins, dressed in the latest fashion and operated by clockwork mechanisms. The device grew so popular that it was gradually enlarged until it became a complete circus.
NEW WOOD FOR TOBACCO PIPES SEASONS MORE QUICKLY
Due to the shortage of genuine briar, a substitute wood has been grown by grafting the gnarled, knotted roots of the bruyere to ordinary red and white hawthorn and with satisfactory results, according to reports. Pipes made from this hybrid wood are said to be light in weight, to absorb nicotine readily, give a cool, sweet smoke, and can be seasoned in about three months as against the three years necessary for the real briar. Another advantage claimed is that the roots grow to three or four times the size of the briar's so that more pipes can be cut from them.
DETACHABLE MOTOR FOR BARGE HAS SAFETY PROPELLER
To speed canal traffic, an English inventor has introduced a motor which may be removed or attached in a few minutes and has power enough to tow three fully loaded barges. Its chief feature is that the propeller is so adjusted that, should it strike an obstacle, it automatically rises above the obstruction to prevent damage. This is an important point when running in shallow waters.
Propeller of This Detachable Motor Rises When It Meets an Obstruction, to Prevent Damage
COSMIC RAYS LINKED WITH CREATION OF MATTER
Artist's Diagrams Showing, Center, How Cosmic Rays Were Measured in a Mountain Lake; and, in Inserts at Left, Earlier Experiments with Electroscopes Sent Up in Sounding Balloons
CREATION OF MATTER IN STAR SPACE EXPLAINS RAYS
The cosmic rays discovered a few years ago by Prof. R. A. Millikan, the famous California scientist, are the waste energy generated by the creation of oxygen, magnesium, silicon and iron in the vast laboratories of outer space, according to a recent announcement by their discoverer. The cosmic rays are the most minute, yet most powerful radiations ever detected, with wavelengths less than one-hundredth of those of radium, and yet requiring the enormous electrical potential of 59,000,000 volts to generate them. Their initial discovery was made by sending electroscopes into the upper atmosphere, attached to sounding balloons, and then studying their recorded findings when the gas bags came back to earth. In his latest experiments, Professor Millikan measured their penetration in the clear waters of a high mountain lake. The presence or absence of the billions of stars which compose the Milky Way had no effect on their intensity, so they apparently come from more distant realms of space. Professor Millikan found that the rays were able to penetrate 16.7 feet of lead or 190 feet of water.
SEEK CAUSE OF PAINT SCALING TO PROTECT WOODS
Paint adheres to wood chiefly by gaining mechanical grip in minute openings on the surface of the wood, forest products laboratory experts have concluded after an investigation into the causes of paint scaling and other factors connected with paints. What is needed, they declare, is an improvement in painting practice, a method that will cause the paint to cling more firmly rather than scale off. The effect of the grain of the wood on the durability of a coat of paint can be seen on wood that has wide annual rings. The part that grew rapidly in the spring contains more openings than the summer part, which is denser. Paint scales off this summer band much more quickly than it does from the spring wood, the investigators found.
¶ Every hour, fires destroy two human lives and approximately $60,000 worth of property in the United States.
SPRAY WAGON FOR FOOTBALL SUBSTITUTE FOR SPONGE
West Point Football Players Refreshing Themselves at the Nozzles of the Gridiron Water Wagon
Football men at West Point have discarded the old unsanitary sponge in favor of a water spray wagon from which eight men may refresh themselves at the same time and with much less trouble. A fine spray is forced through the nozzles in such a way that it reaches the face and neck with cooling effect and without spilling so much water on the suits. The wheels are equipped with heavy rubber tires so that the wagon can be trundled over almost any ground with little difficulty.
AIR-MAIL STAMPER PRINTS TWO COLORS AT ONCE
Ordinary envelopes are quickly identified for delivery to the air mail with a stamping outfit that prints the words "via air mail" in red and blue, conforming to the postal regulations. The contrivance is fitted with a self-contained pad, the rubber die being adjusted for automatic self-inking, in the same manner as most other similar stampers for quick and efficient work.
CAMERA IN POLICEMAN'S CLUB TAKES TWENTY PICTURES
Apparently Holding an Ordinary Club. But Actually Taking Picture with Camera Hidden in Baton
Concealed in the policeman's club, a miniature camera takes from ten to twenty pictures at one loading, and the negatives, although but an inch square, are so sharp that they will stand enlargement up to four inches square or more, it is said. To make an exposure, all that is necessary is to press a button, then turn an unexposed film into place. Time or instantaneous pictures may be made as readily as with an ordinary camera.
TELEVISION TO CONDUCT MUSIC OF HIDDEN ORCHESTRA
Practical use for television has been proposed by an orchestra leader in directing a group of musicians who play off stage during a symphony. Heretofore, it has been the custom to have an assistant leader, who peered through a hole in a wall, took his cues from the conductor and then directed the hidden players as he looked through the opening. By television, the leader's movements will be projected on a screen so that all the second-orchestra members can see them and the need for an assistant conductor will be rendered unnecessary.
LILACS BLOSSOM AT CHRISTMAS WITH AID OF CHEMICAL
Lilacs, flowering almonds and other blossoms may be had for Christmas decorations by exposing the potted plants to the vapor of a special chemical, Dr. F. E. Denny, of the Boyce Thompson institute for plant research, recently reported. The trick is an easy one, the chemicals are obtainable on the market and about the only precaution to be taken is that the gas treatment should be done in a tightly closed room. Ethylene dichloride or ethylene chlorhydrine is used and almost any florist can arrange a treatment room without great expense. Dr. Denny recently demonstrated the effectiveness of the method with two twigs on the same branch, as much alike as possible. The treated twig responded quickly while the other remained dormant. He has also applied chemical "awakeners" to various other plants and has succeeded in getting seed potatoes to grow soon after harvesting. This is expected to be of considerable commercial importance.
WATER SYSTEM FOR THE HOME WORKS AUTOMATICALLY
Advantages of a city water-supply system may be enjoyed in farm and country homes through an electric pumping and pressure outfit that starts and stops itself, is economical to operate and is furnished in two sizes to give either 210 or 420 gallons per hour. The unit is compactly constructed and housed under a hood that can easily be lifted off for oiling or inspection; only two pipe connections are required, and, if desired, the unit may be employed in connection with a big storage tank. The outfit can be installed in two hours. Users do not have to press any buttons or operate any switches and the pump is self-oiling, so that the apparatus requires practically no attention.