It worked perfectly. So well, in fact, that the basic principle of Whitney's gin has never been improved on. So well that those same planters broke into the shed overnight and stole the gin, learning the secrets of its construction before Whitney and his partner, Mrs Greene's new husband Phineas Miller, had patented the invention.

By the time they obtained their patent, in the autumn of 1793, the gin had been copied and bastardised and the pair became ensnared in a nightmare of litigation as they tried to assert their rights.

Whitney and Miller planned not to sell the gin, but to hire out machines to plantation owners, taking in payment one third of the cleaned cotton. But the scheme never worked. Whitney failed to raise enough cash to build the machines on a proper scale, and after recovering from a serious illness he discovered his factory at Newhaven had been burned to the ground. While it was being rebuilt, impatient planters built their own machines.

The partners eventually managed to turn things around, only to fall victim to rumour mongers who put about the story that the gin had a damaging effect on cotton fibres. They disproved this claim, but when they brought their first action for piracy against a plantation owner, in 1797, they lost. By that time, the value of the gin to the Southern states was obvious, and the plantation owners wielded too much power and influence for a jury to find against them.

No fewer than 59 more cases were heard before Whitney and Miller obtained a verdict in their favour in 1808. But by then, their patent had just one more year to run and there was no hope of them recouping their investment.

Whitney had spent all his money on lawsuits. The litigation even cost him the entire grant voted to him by the State of Georgia for his invention. Congress refused to renew the patent when it expired and, like Crompton, he came to the conclusion that an invention could be so valuable to the world as to be worthless to its inventor.

Unlike Crompton, however, Whitney did not fade into obscurity. Instead, he became the father of US mass production, developing the concept of interchangeable parts.

PILE 'EM HIGH ... hundreds of cotton bales on board a Mississippi steamboat. This sort of production would have been impossible without Whitney's gin.

His idea was to replace the skilled mechanic, who manufactured an entire product from start to finish, with semi-skilled workers who used machine tools, templates and jigs to manufacture identical parts, which could be brought together on an assembly line.

In 1799, just a year after his cotton-gin business was closed down, he was given a contract by the US Government for the manufacture of 10,000 muskets. Start-up problems meant that he missed his two-year deadline - he took a further six years to complete the order. But within two years after that, he had made a further 15,000 muskets, and his fortune. But he never again patented any of his inventions, which included a milling machine.

He died in January, 1825.