Farm machine used, mainly in developed countries, to harvest wheat and often other cereals.
The mechanical ancestor of today's large combines was reaper , introduced in 1831. Threshing machines were powered first by men or animals, often using treadmills, later by steam engine s and internal-combustion engine s. The modern combine harvester, originally introduced in California с 1875, came into wide use in the U.S. in the 1920s and '30s and in Britain in the 1940s. The self-propelled combine was introduced in 1940. The combine cuts the standing grain, threshes out the grain from the straw and chaff, cleans the grain, and empties it into bags or grain-storage facilities. It has greatly reduced harvesting time and labour; whereas in 1829 harvesting an acre of wheat required 14 man-hours, the modern combine requires less than 30 minutes.