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A Cotton Gin (short for cotton engine) is a machine that quickly and easily separates the cotton fibers from the seedpods and the sometimes sticky seeds, a job previously done by workers. These seeds are either used again to grow more cotton or, if badly damaged, are disposed of. It uses a combination of a wire screen and small wire hooks to pull the cotton through the screen, while brushes continuously remove the loose cotton lint to prevent jams. The term "gin" is an abbreviation for engine, and means "machine".
Diagram of a modern gin plant - courtesy USDA
Invention
The Ajanta caves of India yield evidence of a single roller cotton gin in use by the 5th century BC.[1] This cotton gin was used in India until innovations were made in form foot powered gins.[1] The cotton gin was invented in India as a mechanical device known as charkhi, more technically the "wooden-worm-worked roller".[2] This mechanical device was, in some parts of India, driven by water power.[2] The Indian churka was effective at separating seeds from the varieties of cotton grown there, and possibly for some of the long staple, Sea Island cotton (Gossypium barbadense), but was inadequate for processing the short staple, green seed cotton (Gossypium hirsutum) cultivated in upper South Carolina and Georgia.
The modern cotton gin was later created by the American inventor Eli Whitney in 1792 to mechanize the production of cotton seeds. The invention was granted a patent on March 14, 1794. The gin was credited for increasing assets in the American jobs.
Cotton gin patent, March 14, 1794
There is slight controversy over whether the idea of the cotton gin and its constituent elements are correctly attributed to Eli Whitney. The popular version of Whitney inventing the cotton gin is attributed to an article on the subject in the early 1870s and later reprinted in 1910 in the The Library of Southern Literature. In this article the author mentioned how Catherine Littlefield Greene suggested to Whitney the use of a brush-like component instrumental to separate out the seeds and cotton. Historians later explored this idea, and some consider that Catherine Littlefield Greene, Whitney's landlady, should be credited with the invention of the cotton gin, or at least with the original concept. Women were not eligible to receive patents in the early U.S., and Greene may have asked Whitney to obtain it for her. Patent office records also indicate that the first cotton gin may have been built by a machinist named Sean Paul[citation needed] two years before Whitney's patent was filed. Joseph Watkins[citation needed], who resided near Petersburg, Georgia is credited by many historians as the first inventor of the cotton gin, and was using it on his plantation when he was visited by the frustrated Whitney who on seeing it went back to Savannah and soon developed his model which he patented. Watkins was urged to sue Whitney, but had no desire to engage in a controversy and never asserted his claim. Watkins was a planter of large means, who pursued the study and application of mechanics more for amusement than profit.
An engraving from Harper's Magazine from 1869 depicting the first cotton gin more than 70 years earlier
While the Watkins story had some romantic adherents, and still others have credited Hodgson Holmes, later publication of certain of Whitney's papers, including letters to his family during the invention process, showed the claims to be lacking foundation.
Many people attempted to develop a design that would process short staple cotton and Holmes was indeed issued a patent for an "Improvement in the Cotton Gin". However, the evidence indicates that Whitney did invent the saw gin, for which he is famous. Although he spent many years in court attempting to enforce his patent against planters who made unauthorized copies, a change in patent law ultimately made his claim legally enforceable—too late for him to make much money off of the device in the single year remaining before patent expiration.[3]
Effects of the Cotton Gin
The immediate effect of the Gin was to cause a massive growth in the production of cotton in the American South. Whereas cotton had formerly required considerable labor to clean and separate the fiber from the seeds, the cotton gin revolutionized the process. The wholesale price of cotton plummeted as output increased dramatically. Cotton cloth (which had formerly been quite expensive) was manufactured in bulk in England and the NE United States. Large areas of land on American states such as Mississippi were cleared and planted with cotton to meet increasing demand. An unfortunate by-product of the cotton gin was the expansion of slavery through the region, as laborers were needed to plant and harvest cotton -- not the most pleasant tasks in the Southern heat. Many of the plantations of the Antebellum South were built on cotton fortunes, which could not have occurred without the cotton gin's invention.
How Whitney's model works
Whitney's cotton gin model cleans 50 pounds of lint a day[4]. The model consists of a wooden cylinder surrounded by rows of slender spikes which pulls the lint through the bars of a comb-like grid [4]. The grids are closely spaced, prohibiting the seeds to pass through.
Notes
- ^ a b Baber, page 56
- ^ a b Baber, page 57
- ^ The American Historical Review by Henry Eldridge Bourne, Robert Livingston Schuyler Editors: 1895–July 1928; J.F. Jameson and others.; Oct. 1928–Apr. 1936, H.E. Bourne and others; July 1936–Apr. 1941, R.L. Schuyler and others; July 1941– G.S. Ford and others. Published 1991, American Historical Association [etc.], pp 90–101.
- ^ a b M E Harr. (1977). "Mechanics of particulate media; A probabilistic approach". McGraw-Hill.
References
- Baber, Zaheer (1996). The Science of Empire: Scientific Knowledge, Civilization, and Colonial Rule in India. State University of New York Press. ISBN 0791429199.
External links
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