In order to harvest grain and process it to be used for food, farmers must cut the grain from the field and separate the grain from the plant. Cutting the grain in the field is known has harvesting or reaping. Separating the grain from the plant is known as threshing. Harvesting and threshing were two separate jobs, but machines called “combines” save farmers time by both cutting and threshing in one step.
This combine was patented in 1879. Notice the machine was powered by steam, but the farmer still relied on horses to move the machine through the fields.