No distinctive improvement has been made since, except to add strength and simplification.

The machine now needed the services of only two men, one to drive and the other to shock the bundles, and could reap twenty acres or more a day, tie the grain into bundles of uniform size, and dump them in piles of five ready to be shocked.
Grain must be separated from the straw and chaff.

The Biblical threshing floor, on which oxen or horses trampled out the grain, was still common in Washington's time, though it had been largely succeeded by the flail.

In Great Britain several threshing machines were devised in the eighteenth century, but none was particularly successful.

They were stationary, and it was necessary to bring the sheaves to them.