High Quality Content by WIKIPEDIA articles! The thrashing machine, or, in modern spelling, threshing machine (or simply thresher), was a machine first invented by Scottish mechanical engineer Andrew Meikle for use in agriculture. It was invented (c.1784) for the separation of grain from stalks and husks. For thousands of years, grain was separated by hand with flails, and was very laborious and time consuming. Mechanization of this process took much of the drudgery out of farm labour.