For thousands of years wheat was harvested by sickles and other tools. Dozens of workers had to be on one field at once because this was a slow hard job for each of the workers.
Wheat crops grew well in South Australia and in 1843 they grew too tall and combined with a general lack of labor made it very difficult to harvest and meet the current demand. A competition was started in which the inventor who builds the best design for a machine that could cut wheat faster than by cutting by hand.
Nobody won this competition but there was a lot of interest in a machine entered by John Wrathan Bull. His machine had a comb to grip the wheat and a beater to thresh the grain.
John Ridley built a machine that improved on Bulls basic design that actually did harvest the crops faster and more efficiently than any of the workers could, except the heads of the wheat was not winnowed to strip the chaff from the grain.
Others continued to copy and improve on the design and by the 1880s Wheat stripping machines were in use throughout Australia and the world.