ELI WHITNEY'S cotton gin was the final process in the automation of cotton production. But although it brought prosperity to the Southern United States, it brought little material reward for its inventor.

Whitney was born in Westborough, Massachusetts, a little town about 30 miles west of Boston, on December 8th, 1765, the son of a farmer who supplemented his income by making wheels and chairs and doing odd jobs for neighbours.

As a youngster, Whitney showed little interest in farming but he had his father's aptitude for intricate craftsmanship. Like England's Samuel Crompton, inventor of the spinning mule, at the age of 12 he made his own violin, and once took his father's watch to pieces, then reassembled it so no-one was the wiser.

The young Whitney started a business making nails during the War of Independence, and later manufactured hat pins for women and walking sticks for men.

Meanwhile, he was studying hard in his spare time and in May, 1789, managed to enter the freshman class at Yale, graduating in 1792.

A few months later, he obtained a job as a tutor in Georgia and it was on the journey to Savannah that he fell into the company of Mrs Nathaniel Greene, the widow of the Revolutionary general.

Perhaps fortunately for posterity, when he arrived in Georgia he found the tutor's post already filled, so he accepted Mrs Greene's offer of hospitality and stayed at her home while he studied law.

As a thank-you, he built a new embroidery frame to replace his hostess's broken one, and then occured one of those coincidences on which history sometimes hinges.

A group of officers who had served under Mrs Greene's husband came to pay their respects. Most of them were now planters and as they sipped their mint juleps, the conversation turned to cotton and the desperate need for a machine that would separate the cotton fibre from the seeds and husks.

Cotton as a commercial enterprise was relatively new to the United States at that time - the Deep South's first major crop had been harvested just two years previously. But there was a solid and growing demand for it, to feed Britain's rapidly expanding textile industry.

The job of cleaning the cotton was difficult and time consuming. It could take a worker a whole day to remove the seeds from

CROSS-SECTION of Whitney's gin. Raw cotton is fed into the hopper (top), and rotating saws pull the fibres through a grid, tearing them from the seeds and husks which are expelled (right). Cleaned cotton appears (left)

Mrs Greene, who had been highly impressed by the embroidery frame, told her neighbours: "Gentlemen, apply to my young friend Mr Whitney. He can make anything."

Whitney protested that he had never even seen a cotton plant. But he put aside his books and travelled into Savannah to search the docks and storehouses. He returned with a sample of cotton fibre and set up a workshop in Mrs Greene's basement. First, he made his own tools and then laboured throughout the winter of 1792-93.

By early spring, he had set up his prototype cotton gin in a shed on the estate, and planters from all over the state were invited to watch it in operation.