A mule jenny is a hand-operated textile spinning mule.
Samuel Crompton invented the spinning mule in 1779, so called because it is a hybrid of Arkwright's water frame and James Hargreaves' spinning jenny (a mule being the product of crossbreeding a female horse with a male donkey. A female donkey is called a jenny). With the development of the self actor, the hand-operated mule was increasingly referred to as a mule-jenny.[1]