John Kay's (1704-1764) invention of the flying shuttle in 1761 made it possible for one man to weave material wider than the length of his extended arms--material so wide that a normal loom would require two or even three men to cast the shuttle back and forth. As use of the flying shuttle increased, a new shortage of thread became apparent, for one man, using a spinning wheel, could only produce one thread at a time. A reward was offered to the man who invented a machine to increase the spinner's productivity. While it is not known if he ever received that reward, the man who ultimately invented the machine was James Hargreaves, and the machine was the spinning jenny.

The origin of the jenny's name is unclear. Some say that it was named after Hargreaves' wife; others, that it is a colloquialism for engine; still others...