Popular Mechanics/Volume 49/Issue 1/Dummy Flyers Help Make Air Safe
Dummy Flyers Help Make Air Safe
By R. BACHE
Tumbling Headfirst from a Plane, the Parachute Jumper Is Jerked Upright as the Silk Umbrella Fills with Air; at Bottom of Page, a Seat-Pack Chute Which Takes the Place of a Cushion
Dummy aviators are importantly helpful in trying out new ideas for parachutes. They afford just as good safety tests as live men, and, in case of accident, nobody is hurt. A fall of a few thousand feet or more doesn't bother the dummy.
The typical dummy used by aeronautic experimenters of our army and navy is made on a strong wooden frame, covered with canvas, and stuffed with any kind of material that happens to be handy, an essential requirement being that it shall weigh 180 to 200 pounds. Thus its weight corresponds to that of the heaviest airman. It has a neck but no head: the legs and arms are mere stumps. The parachute equipment is fastened upon it with a harness of straps, exactly as it would be attached to a man.
The equipment is a "seat pack," secured to the lower part of the dummy's back. This kind of pack, used as a seat cushion by an aviator, removes all weight and bulk from his person, save for the harness. It is a canvas envelope containing a parachute of light and very strong silk, twenty-four feet in diameter, carefully folded in a particular way, and weighs eighteen pounds.
When the dummy is dropped experimentally from an airplane far aloft, the rip cord connected to the pack is simultaneously jerked, releasing the parachute. But the first thing to emerge from the canvas envelope is a small "pilot chute," thrown out by springs. Catching the wind, it exerts a pull which yanks the big parachute out of the pack, and thereby the parachute is enabled to expand quickly.
It is fully opened by the time the dummy has fallen 150 feet. Then, the expanded umbrella having caught the resisting air, it floats downward toward Mother Earth at a rate of thirteen feet a second. The loftiest height in the sky from which a parachute jumper has ever leaped was twenty-six thousand feet, or nearly five miles. It took him a little over half an hour to reach the ground. but he alighted safely. The first parachute drop from a flying machine was made in 1912, at St. Louis, by Capt. Berry. The chute was folded and stuffed into a cylindro-conical metal container. In the following year, the first "knapsack" parachutes were developed, with a rip cord to open the pack. The seat pack is designed for flyers who do not move about during flight. Another type is the "lap pack," which rests in the lap of the airman. It is especially for use by gunners and observers. A gunner usually has the most available room directly in front of him and below the waist line.
{{cWith Knees Drawn Up to Absorb the Shock, the Flyer Prepares to Land. Top; a Test Dummy, Center, and an Old Sketch of Garnerin's First Jump in England in 1802}}
To learn how to use a parachute requires no natural aptitude beyond the ordinary, and very little training. The aviator. when he jumps from aloft, holds in his hand a ring to which the rip cord is fastened. All he has to do is jerk it, and the rest of the business takes care of itself. The sensation of floating downward is described as being rather agreeable than otherwise.
GIANT "HOOP" FOR GENERATOR IS MARVEL OF WELDING
Electrically Welded Frame for One of the 50,000-Horsepower Generators Being Installed by Philadelphia Power Company
What is said to be the largest piece of electrical machinery ever made from structural steel and electrically welded has been completed in the frame for one of the 50,000-horsepower generators for a Philadelphia company. Four of these huge units are to be installed in this plant, which will be the largest electricity "factory" in the United States except the power development from Niagara falls.
TINY FISH FANS ITS YOUNG TO SUPPLY OXYGEN
Fish placed in water that has been boiled to drive out the oxygen usually die in a short time, showing how necessary the element is to the preservation of their lives. The little stickleback fans the nest in which the young are hatched with its fins to afford an abundant oxygen supply and another species exercises the same care, both parents taking their turn doing the fanning.
ELECTRIC HANDS MOVE CARS IN TALL GARAGE
Space for parking 1,052 cars is to be provided in a twenty-eight-story garage for New York City's crowded business district. It is to be within a few feet of one of the entrances to the Grand Central terminal, and is planned to afford a maximum of storage space within the limits of the lot. After a driver has surrendered his car and received a check for it, an electrically operated truck rolls from an elevator, is stopped under the auto, the rear axle engaged in a rubber-cleated coupler, and then the car is taken back to the elevator, and run to the desired floor, being left in its space by a reversal of the method that was pursued at the first. The little trucks are governed by push buttons in the elevator, so that the operator need not leave his post or touch the auto to store it. Elimination of ramps and useless aisles, highspeed elevators, and street-level delivery and acceptance are other features.
One of the "Electric Hands" That Move Cars: Truck Adjusted under Auto to Slide It on or off Elevator
ROWING DRILL IN ONE-MAN TANK GIVES OARSMAN PRACTICE
Rowing Practice in His Yard: British Oarsman in Stationary Boat near Tank in Which He Can Keep in Training with Real Strokes: Splash Guard around Rim at Left
To keep himself in training, a British oarsman has a private tank just large enough for one oar. He sits in a stationary "boat" and sweeps the oar through the water as though in an actual race. The boat has a sliding seat, similar to those in the usual racing hull.
INSECT WEATHER PROPHETS
If spiders are busy spinning their webs, fair weather may be expected, but if they are resting, the fact is an indication of impending storms or wet weather, some naturalists say. The reason is that the spider, knowing that its prey will not be abroad during rains or other unfavorable conditions, does not trouble to make its nest at such times. but prepares it for catches during fair weather. Bees are able to tell approaching storms and in threatening intervals will not venture far from their hives. The noise of the screech owl at night is also claimed to be an indication of fair weather.
ENDLESS TRACK FOR TOY TRAIN NOVEL WINDOW DISPLAY
Adding Interest to the Window Display: the Double-Spiral Track for Toy Electric Train Occupies Small Space
Designed especially for window display, a spiral tower for an electric toy train, permits continuous running in smaller space and adds to the interest in the operation. By means of transformers, the train ascends on a current of nine volts and comes down on five and one-half volts, in order to make sure that it will not run off the track. For home-play purposes. the outfit can be operated with but one transformer.
SHARK SHIP HUNTS SEA TERRORS TO MAKE SHOES
EXCELSIOR BUILDING BLOCKS NEW HOME MATERIAL
Building blocks of compressed packing excelsior, impregnated with a mineral cement which makes them practically fireproof, are being used successfully in a new form of home construction. The blocks, four by eight by sixteen inches, are each equivalent to eight ordinary bricks in volume, but, weighing only three pounds, are less than one clay brick in weight. Each block is pierced by two four-inch holes, and when they are laid in overlapping row, as are bricks, the holes match. After three rows or courses are piled up, steel reinforcing clips are inserted, and the holes filled with concrete. The clips are equal to four courses, and each pouring ends one below the top, so that a continuous bond is obtained. The finished wall is a series of four-inch reinforced concrete columns, spaced four inches apart, and surrounded by the compressed-excelsior blocks. At the floor levels a four by eight-inch reinforced-concrete beam is worked in, and the next wall started on top of it. Laboratory tests show the material is equal to four inches of cork in insulating value; that it is a sound deadener and that a reinforced wall built of it will carry a load of 16,000 pounds per running foot. No skilled labor is required in laying the walls, as the blocks are simply piled on top of each other, the steel reinforcing dropped into the holes, and the concrete poured from an ordinary coal scuttle. No lath is required on the inside, plaster being applied direct to the blocks, the fibers of which furnish a good bond, and stucco is applied in the same way on the outside. Owing to the mineral cement with which the blocks are impregnated, they will not support combustion.
Detail of Construction with the Blocks, Showing Concrete Section and Close View of Excelsior Unit
MENACE OF FLY'S FOOTPRINTS REVEALED BY MICROSCOPE
At Left, Fly Footprints and Microscopic Enlargement of Same; at Right, Showing Germ Growth
That the fly is a spreader of dirt and disease has long been known, but the microscope reveals a particular reason why the insect should be killed. Its footprints are scarcely visible to the unaided eye. even when materials make the marks plainer, but examination of the tracks a few hours after they have been formed, explains the hazard of allowing the fly to walk across articles that should be kept clean. The microscope shows how tiny disease germs in substances carried by the fly's feet, have developed. A few hours after the photograph was taken, some of the germs had developed tiny balls of spores which were carried away in the air to seek lodgment and possible growth. Where flies have been eradicated, a marked decrease in disease has been observed.
CHART TO TEACH TYPEWRITING SAVES STUDENTS TIME
Chart in Use and Close View Showing Perforations That Take Place of Typewriter Keys
Paper keyboards, with perforated tops to guide the fingers. have been introduced by a woman inventor to help teach typewriting. The charts make it unnecessary to use the real machines at first, so that the student can devote his entire attention to learning the position of the keys and is not distracted by the mechanical operation of the typewriter. In practice, the subject learns the correct hand and finger positions with the chart guides and then, to test his skill, writes the name of the character on the piece of paper under the openings. According to reports, results with this guide have been successful and it is recommended especially for correspondence schools.
VOICE STARTS AND STOPS TRAIN BY RADIO CONTROL
Visions of what vast possibilities of service still lie in the power of radio were shown to visitors at a recent engineering exhibition in London, at a model-train display. The engines started instantly as a man said "Off," and when the word "Stop" was pronounced, they obeyed as quickly, and also reversed or went forward at spoken commands. The secret of the performance was that the vibrations of the voice, passing through a microphone, affected sensitive controls which released electric current to cause the proper movements. During one of the demonstrations, a collision was avoided. One of the tiny trains ran off the track on a sharp curve. Another was rushing toward it, but the operator saw the impending disaster, shouted "Stop," and the train halted. While the system, as now developed, could not be practically adopted in commercial railroad operation, engineers point out that it holds vast promise in that direction as well as in the performance of other tasks, such as opening doors and windows and doing other duties that ordinarily require the direct muscular effort of some person. The dream of a day when a housewife can sit comfortably in her chair and deliver vocal orders to the oven door to open, the furnace draft to close, etc., is not impossible of realization, radio experts believe.
ELECTRICAL PEAKS AND DIPS SHOWN BY SOLID MODEL
Model of Graphs to Show Electric-Load Fluctuations of German Station; Scales Printed at Sides
In a German electric station a complete record of the load fluctuations for every day of a whole year is built up in solid form by cutting out the daily graphs and arranging them side by side, as shown. Scales are arranged on two sides, indicating kilowatts, and along the base indicating months and days, and hours of the day and night. The whole gives an easily comprehensible view of the year's output.
PORTABLE FOOT BRIDGE OF PIPE AIDS ARMY DRILLS
Crossing the Pipe Bridge; Soldiers on Maneuver Using the Portable Viaduct Which Is Quickly Assembled from Lengths of Piping and Is Strongly Braced
Portable bridges made of piping are being used by the British army instead of the usual wood and rope units. They are stronger and more easily assembled, being especially suited for drill maneuvers.
SEARCH FOR OIL LEADS TO SEA ON CALIFORNIA COAST
Oil wells, drilled in the surf of the Pacific along the California coast, have been producing for some time, and now various companies are making plans to sink their shafts farther out to sea in the hope of tapping more abundant supplies of "black gold." The problems involved will tax the ingenuity of engineers, but are not considered so difficult as to balk the attempts to obtain the liquid wealth below the waves. Often the oil-well derricks and machinery weigh hundreds of tons. It will be necessary to build strong foundations for this equipment. Some of the wells are planned for areas where high tides will wash across the derrick floors part of the day. One concern has been granted permits to dig wells a quarter of a mile from shore, if it is mechanically possible to do so. Engineers estimate that it will cost approximately $25,000 to construct each of the bases for the derricks and difficulties, not known in land operations, are expected in drilling, but if the oil is present in as large quantities as the preliminary soundings indicate, it will pay to "buy the ocean and pump it dry," in the opinion of some of the experts.
PIPE-CLEANING SET IN HOLDER CARRIED LIKE PEN
Contained in a holder which is carried in the pocket, a pipe-cleaning set now on the market is kept from soiling the clothing and in position for use at any time. It consists of two tools, one for the bowl and the other for the stem.
CABINET CONCEALS COOKSTOVE AND REDUCES ODORS
Stove Concealed in Cabinet; Inset Shows Appearance of the Unit When the Doors Are Closed
For the small home or apartment, a metal cabinet has been devised to inclose the gas cookstove, shielding the rest of the room from odors, excess heat and smoke, and adding to the appearance of the cooking quarters. The doors have louvers at the base to admit cool air from close to the floor. This sweeps up through the cabinet and out into a chimney duct at the top.
SHALE MAKES CONCRETE LIGHT WITHOUT STRENGTH LOSS
The use of burned shale or clay in place of sand and stone in concrete, for buildings and bridges, has resulted in a lighter material without a sacrifice of strength, engineers declare. Ordinary concrete weighs about 145 pounds to the cubic foot, but the shale mixture only ninety-five pounds. The material is about the same as that employed in the manufacture of brick. It is heated to a high temperature until it becomes plastic, this process expanding the mass and causing a large number of small pockets or air cells to form, owing to the escape of gas. This light stuff is then crushed and used instead of sand for mixing with the cement. Its aid in building was illustrated recently in Kansas City, where six stories were added to a structure originally intended for but four more. Use of the lighter cement enabled the engineers to erect two extra stories without hazard.
FURNITURE HEAVIER IN SUMMER
Wooden furniture absorbs moisture, consequently, in moist seasons, is heavier, as a general rule, than it is in winter when the house is heated. A bureau, weighing 200 pounds, may be twenty-four pounds heavier under average summer humidity as compared to its normal weight when the furnace is going and the air in the rooms is drier. These changes occur in spite of paints, enamels and other finishes, tests by the United States forest service have shown. The coatings are none the less useful, for they prevent sudden checking and swelling that would result were the wood not so protected.
SOFT RUBBER AS UPHOLSTERING SUBSTITUTE FOR SPRINGS
In place of springs, sponge rubber is being used for upholstering automobile seats and other articles. The material is said to hold its shape, give the covering longer wear and to be more comfortable than other kinds. It is strong and easily shaped to give uniform resiliency.
{{c|Rubber Upholstering for Chair Bottom: Its Soft, Spongy Texture Is Revealed When It Is Squeezed
FLYING BOAT THAT CARRIES TEN LINKS HAMBURG TO LONDON
For Faster Trips between Hamburg and London, the Ten-Passenger Flying Boat in Action; Its Two Motors Afford a Speed of 150 Miles an Hour
One of the latest units in aerial travel between London and Hamburg is a ten-passenger flying boat. It develops a maximum speed of 150 miles an hour, has two motors, aggregating 1,300 horsepower, and when loaded weighs 23,100 pounds. The wing span is eighty-five feet. A crew of three is required to operate the ship, which is fitted with running water, electric lights, and radio-receiving and sending apparatus. It can land or take off from ground or water with equal facility.
CANARIES THAT CAN SING JAZZ GAIN IN POPULARITY
Roller canaries, with classical musical educations, are giving way to the chopper, a songster with shorter, brisker notes more like those of the jazz melodies and other compositions popular today. According to a bird dealer, the chopper is a twelve-to-one favorite over the roller in the markets. Owners have also noticed that frequently a jazz phonograph record will stimulate their canaries to sing when other means fail. Canaries are being imported into the United States at the rate of several thousand a week, many of the most valuable kinds coming from the Hartz mountains in Germany. Because of their tendency to fight, the males have to be shipped in individual cages, but 100 females can be placed in a single cage.
STOP WATCH FOR FOOTBALL TO END DISPUTES
Seconds are precious when the football score is tied and one team is within inches of the goal line. A stop watch, designed to simplify the task of allowing for intermissions, time-out intervals and other irregularities, has been introduced this season. The dial records seventy-five minutes, for four quarters of fifteen minutes each and a fifteen minutes' intermission between halves. There are really two watches, one that records the time of playing and the other, the time taken out. By pushing a lug, the operator sets one mechanism to operating and stops the other. Markings show the official when to notify the teams to get ready to leave the dressing rooms and indicate the number of minutes remaining to play.