The Combine Harvester: Cut, Thresh, Separate and Clean in One Pass

Grain harvest was once a chain of separate jobs: cut with the reaper, bind and stook the sheaves, carry them to the threshing machine, winnow what it gave. The combine joins them: it cuts the standing crop, threshes the grain out, separates it from the straw, cleans off the chaff and carries the grain to a tank, while the straw goes out of the back. Hiram Moore of Kalamazoo County, Michigan, backed by his neighbour John Hascall, built a working combined harvester in the mid-1830s and patented it in 1836. In California, Benjamin Holt's combines of 1886 drove their mechanisms by link belts rather than gears, so a jolt broke a belt instead of stripping a gear; the machine cut, threshed, cleaned and bagged the grain. This rung works out the threshing impact and the air speed that cleans, and separates grain from straw and chaff with a fan on the bench.