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Show -LrcL"Lospiere Bed loon. , , - I ; ' ,: ; x - - - -Lc-' - 'j'1' , 1 " Gondola for Stratosphere Flight. its attachments and load, it will weigh nearly eight tons. The gondola is a huge hollow ball 8 feet 4 inches in diameter, that haa been built up by welding together eight sections shaped like pieces of orange peel. The shell made of dow-metal dow-metal is slightly less than three-sixteenths of an inch thick. At first glance the big metal ball seems to be built of steel; and it is almost as strong as though it were. But the shell, as it stands, without its various fittings, weighs only 450 pounds. If it were made of steel, it would weigh practically a ton. The two largest openings in the gondola, gon-dola, just above the "equator line," are manholes one each for Maj. William Wil-liam E. Kepner and Capt. Albert W. Stevens, the "crew." The manholes are fitted with covers, which will be clamped down until air-tight by a heavy bolt, easily tightened and loosened loos-ened by hand from within. On the way down from the stratosphere, strat-osphere, when breathable air has been reached, these manhole covers will be lifted from their hinges and thrown overboard attached to parachutes as ballast. Numerous small portholes have been provided in the shell of the ball. Some are covered with glass and will serve as observation windows ; in some the lenses of cameras are mounted with air-tight fittings ; and in others scientific scien-tific instruments have been placed. One glass-covered port is situated in the exact top of the sphere so that Major Kepner, the balloon pilot, can look up through it and through the Prepared by National Geographic Society, Washington, D. C. WNU Service. THE huge balloon, which will be used in the stratosphere flight sponsored jointly by the National Nation-al Geographic society and the United States army air corps, is the largest ever constructed. It will take the air from a protected spot in the Black Hills near Rapid City, South Dakota. The balloon was made in a vast room in an Akron, Ohio, factory, whose windows were sealed, whose air was strained through canton flannel, and where men and women employees wore grit-free "slumber shoes" of cloth as they walked over rubber-impregnated fabric. The bag is capable of holding three million cubic feet of hydrogen gas. This capacity is nearly three and a half times that of the largest free balloon hitherto built. The finished bag which was rushed westward to the point of takeoff by truck, will lift two intrepid officers and a cargo of specially designed scientific instruments near fifteen miles above sea level. Not a stitch was taken In putting together more than two and a third acres of cloth. Instead of being a job for a seamstress or a sail-maker, the task was closest to that of a news editor ed-itor pasting together pages of "copy" or a librarian mending a torn page. Everyone of the 3,520 major pieces into in-to which the fabric was cut, and each of .the scores of smaller fragments, was cemented with the greatest care to its next-door neighbors with rubber cement. The next step was to cover the cemented seams of this jigsaw puzzle puz-zle with fabric-backed rubber tape on both sides. When these operations were completed the seams were actually actual-ly stronger than the neighboring fabric. More than 300 gallons of cement the purest rubber dissolved in gasoline gaso-line and benzol were required to put the balloon together. Immensity of the Balloon. Although the balloon room In which the great balloon was made is three hundred feel long and in places more than a hundred feet wide, that area was not a large enough one in which to spread out the completed bag. Portions Por-tions of the bag as large as racing yacht main-sails, assembled on the floor during construction, represented relatively small fragments of the balloon bal-loon area. Half of three "orange-peel" "orange-peel" sections, or "gores," cemented together and spread out, covered nearly near-ly half the floor of the balloon room. Yet twenty-five sections equally as large had to be cemented on tj this piece before the bag was finished. Owing to the huge size of the balloon bal-loon segments, final construction operations oper-ations required piling them in long windrows of pleats with only the edges exposed for cementing. After large sections of the balloon were put together, thousands of cubic feet of air was pumped under the fabric to float it off the floor for inspection. Men under the cloth looked through it to strong light, finding any thin spots. These were reinforced with rubber patches. Cloth for the balloon was made from specially selected cotton of unusually long, strong fibers. It was woven in strips 42 Inches wide and 300 feet long. One hundred and thirty of these massive rolls were used in cutting out the balloon 39,000 running feet or more than seven and a third miles of cloth. Every square foot of the amazing amaz-ing acreage of cloth passed through a rubberizing machine thirty times, each time receiving a very thin coat of rubber. rub-ber. More than SO employees worked on the balloon under a balloon-building expert, who, during the past twenty years, has supervised the construction of more than a thousand balloons and airships for the army and navy. Tacking the completed balloon for its westward trip was no small problem. prob-lem. It was probably the largest unit of fabric that was ever transported. It required folding with extreme care and its surfaces, and folds had to be protected so that there would be no rubbing. Gondola Is of Dowmetal. Without a single rope, and without its valves, the bag weighs approximately approxi-mately 4,700 pounds. With ropes and valves, but without the gondola and Its trappings, the balloon's weight Is slightly over 5,000 pounds. When the balloon rises from the earth with all open bottom of the balloon appendix, and can read a large thermometer dial near the top of the bag which will tell him at all times the temperature of the hydrogen gas. The opening In the bottom of the metal ball was reserved for a large aerial camera which will make frequent fre-quent photographs of the earth, straight downward. Part way up the curved side of the gondola is another camera opening for the taking of oblique photographs. Shelves for Apparatus. A series of shelves have been provided pro-vided inside the ball between upright posts and the shell ; and on them will be stored the dozens of pieces of scientific scien-tific apparatus, batteries, oxygen flasks, and other paraphernalia needed for twelve hours of scientific "housekeeping" "house-keeping" in the stratosphere. Around the edge of the floor will be piled forty-pound sacks of lead dust for ballast. bal-last. The most unusual assortment of scientific sci-entific instruments that has ever been brought together to fathom the secrets of the upper air many of them provided pro-vided with "electric brains" and "photographic "pho-tographic eyes" were built and assembled as-sembled at Wright field In the huge machine shop and laboratory of the United States army air corps. In this "pay load" of nearly a ton of apparatus lies the reason for the most ambitious stratosphere expedition expedi-tion yet planned. All of the work at Dayton on the devices to gather scientific data was done under the personal supervision of Captain Stevens, famous aerial photographer pho-tographer and observer, who has himself him-self designed some of the instruments. Probably the most important instrument instru-ment invented by Captain Stevens is a balloon valve of unique design. Heretofore Here-tofore it has been necessary to operate oper-ate a valve in the top of a balloon bag by means of a rope tugged from the gondola far below. As balloons have increased In size, this type of valve has become less and less satisfactory. satis-factory. Captain Stevens' valve will be opened by means of a long rubber hose Into which compressed gas will be admitted. When the air pressure Is released, the valve closes. The principle is like that used for operating air brakes. The valve lias been tested through 400 feet of rubber hose In a cold chamber whose temperature was minus 45 degrees centigrade. It worked perfectly. |