Two close-up views of a demonstration of the cold-drawing technique used to produce the 3-16 polyester super-silk fiber, the forerunner of nylon. This technique was discovered by DuPont chemist Julian Hill (1904-1996) in April 1930. Using a special molecular still to synthesize a 12,000-weight polyester substance, Hill found that, after cooling, the molten material could be stretched, or cold drawn, into a thin, yet extremely strong and flexible fiber similar to silk. While the new fiber's low melting point made it unsuitable for use in commercial textiles, Hill's discovery enabled fellow DuPont chemist Wallace Carothers (1896-1937) to cold draw the more commercially successful polymer, nylon, four years later.