National Geographic : 1943 Jan
Glass "Goes to Town" New Electric Welding Makes Glass Piping Practical "The room of a thousand curves," they call one installation where fruit and vegetable juices flow through transparent "victory glass" which replaces stainless steel (Plate VI). Here Corning glass plumbers fuse glass pipe joints by torches of gas flame and high frequency arcs (page 2). glass" that float like cork, and can be sawed, cut, or drilled with carpenters' tools (page 2). A piece the size of a pound of ordinary glass weighs little more than an ounce. It is water proof, fireproof, verminproof. Aboard ships, on trains, for houses, and in refrigerators it is used for insulation. Making Thread from Sand Most uncanny of all glass operations is mak ing thread or wool from sand. The product defies all the layman's preconceptions of the way glass should behave. It can be bent like rubber, twisted like string, woven like cotton, and when a wad of it is pressed, the mass bounds back into shape like a sponge (Plates IX and XII and page 39). Into factories roll trainloads of sand and lesser quantities of other ingredients. There from pour glass wool and glass yarn for scores of products. A strand of glass fiber may be 15 times finer than human hair, and have a tensile strength greater than steel. To form such strands the manufacturers first make marbles by the ton. Continuous filaments are drawn out faster than a mile a minute. A single marble yields a spiderweb filament that would reach from Washington, D. C., to Wilmington, Delaware. A pound of fiber would go around the world. Overshadowing all the hundreds of uses of glass fibers is that of halting heat, cold, and electricity; resisting water and acids; and deadening sound and vibration. In modern industry glass is the great insulator. Two types of glass fiber have been devel oped. The woolly kind is used chiefly for thermal insulation in the form of batting, blankets, and boards. The textile type makes threads and yarns which are woven into elec trical insulation materials, and into a variety of versatile fabrics that defy stains of most everything, from fried eggs to nitric acid. Wartime services of such glass range from protecting fuel and oil from subzero cold in high-flying airplanes, to sheltering batteries in submarines, shockproofing radio and control panels on battleships from the air compression that follows the firing of a heavy broadside, and cushioning batteries from the terrific jouncing of armored cars and tanks. Bulk of the wool filters air and insulates houses, ranges, refrigerators, and water heat ers. Railroads use it; so do buses, trucks, planes, and ships. Much of it goes to sound proof factory walls.