This was the way looms worked for centuries and it was fine as far as it went. But it meant that a single operator could not weave material wider than his outstretched arms, and both his hands were occupied in catching and throwing the shuttle.

What Kay did was to mechanise the process. The shuttle was flung from side to side mechanically, from spring-loaded boxes placed either side of the loom, using what he termed a fly cord and a picking stick. It needed just one hand to achieve this, freeing up the other to operate the reed comb which, besides separating the warps, also compacted the weft threads to complete the weaving process.

Even before Kay's invention, a weaver could use the output of four spinners - the workers who used spinning wheels to produce the cotton thread required by the loom. These were often members of his immediate family.

Now, using the flying shuttle, a good operative needed up to 16 spinners to keep him occupied and, consequently, he was forced to spend much time tramping his district trying to buy thread, and was often idle for long periods.

So immediately, the search began to find a way of removing the spinning bottleneck, by mechanising that job, too. It was a search which was to lead, eventually, to the complete mechanisation of the cotton manufacturing process and the introduction of the factory system.

Kay's flying shuttle was taken up first by woollen weavers who, at that time, still dominated the Northern textile trade. But they declined to pay him royalties and he was almost ruined by the cost of litigation.

When his patent expired in 1747, Kay petitioned Parliament for an Act that would allow him to recoup the money owing to him from these pirates. He gave the government a three-day ultimatum, and at the end of that time he set of for a new life in France.

The French treated him a little better, refusing to grant him a £10,000 lump sum for all rights to the shuttle, but giving him a pension of about £120 a year. French weavers, however, were slow to take up what they called the "navette volante" and, as the flying shuttle began to make inroads into the English cotton and wool trade, he returned to Lancashire for a spell, probably to make and sell the device himself.

However, his moorland home at Bury - which is still in existence today as a private dwelling - was raided by machine breakers in 1753. There is evidence that these neighbours were out to kill him, and Kay escaped their clutches only by climbing out of a window and legging it across the moors.

A workman who was left behind avoided detection by hiding in a sack of wool.