Cotton gin

A cotton gin is a machine that quickly and easily separates cotton fibers from their seeds, allowing for much greater productivity than manual cotton separation. The fibers are then processed into various cotton goods such as linens, while any undamaged cotton is used largely for textiles including clothing. Seeds may be used to grow more cotton or to produce cottonseed oil.

Although simple handheld roller gins had been used in India and other countries since at earliest 500 AD, the first modern mechanical cotton gin was created by American inventor Eli Whitney in 1793 and patented in 1794. However, the Indian worm-gear roller gin, invented some time around the sixteenth century, has, according to Lakwete, remained virtually unchanged up to the present time. Whitney's gin used a combination of a wire screen and small wire hooks to pull the cotton through, while brushes continuously removed the loose cotton lint to prevent jams. It revolutionized the cotton industry in the United States, but also led to the growth of slavery in the American South as the demand for cotton workers rapidly increased. The invention has thus been identified as an inadvertent contributing factor to the outbreak of the American Civil War. Modern automated cotton gins use multiple powered cleaning cylinders and saws, and offer far higher productivity than their hand-powered forebears.

Cotton fibers are produced in the seed pods ("bolls") of the cotton plant where the fibers ("lint") in the bolls are tightly interwoven with seeds. To make the fibers usable, the seeds and fibers must first be separated, a task which had been previously performed manually, with production of cotton requiring hundreds of hours of labor for the separation. Many simple seed-removing devices had been invented, but until the innovation of the cotton gin, most required significant operator attention and worked only on a small scale.

The earliest versions of the cotton gin consisted of a single roller made of iron or wood and a flat piece of stone or wood. Evidence for this type of gin has been found in Africa, Asia, and North America. The first documentation of the cotton gin by contemporary scholars is found in the fifth century A.D., in the form of Buddhist paintings depicting a single-roller gin in the Ajanta Caves in western India. These early gins were difficult to use and required a great deal of skill. A narrow single roller was necessary to expel the seeds from the cotton without crushing the seeds. The design was similar to that of a mealing stone, which was used to grind grain. The early history of the cotton gin is ambiguous, because archeologists likely mistook the cotton gin's parts for other tools.

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