The process of separating the wheat from the chaf also was speeded up by the application of new technology. The principle of the flail was simple: the thresher beat the grain until the kernels broke away from the straw. Wind often helped by blowing away the chaff. The first mechanical innovation was a rotating spike-toothed cylinder that tore the straw apart and, in the process, knocked the kernels from the stalk. To this a series of shaking sieves was added to help separate the grain from the straw and chaff. This unit, consisting of a cylinder and a separator, was driven first by horses but, as the use of steam and gasoline engines became feasible, it was adapted to machine power. And as tractors grew, becoming, eventually the giant units of the early twentieth century, the threshing separator grew in size. It also acquired a blower, which blew the discarded straw into piles which eventually were burned. This photograph shows a steam- powered, belt-driven unit. The blower can be seen in the background on the right. Horses of course were still used to bring the grain to the threshing site.
By the turn of the century, these huge threshing outfits were an important part of prairie life. They moved from farm to farm, in some cases travelling the length of the continent to keep abreast of the harvest, employing an engineer, a fireman, a fuel and water hauler, a number of field men with horses to haul sheaves to the machine and several more to feed the machine and haul away the grain. Thus as many as fifteen to thirty men and an equal number of horses, plus a cook and cook's helper, were required on a crew.
The introduction of smaller, cheaper gasoline tractors and of smaller threshing machines returned the harvest to a family operation, a tractor operator, a combine operator and a truck driver. In the last quarter-century, self-propelled combines have eliminated even the tractor, so two people now do the work of fifteen to thirty, often in air-conditioned comfort and to the accompaniment of recorded music.
