††††World War 1 increased the demand for food and the use of tractors, instead of horses, allowed large areas of land to be brought into cultivation. Many tractors of various makes were imported into the British Isles from the United States. The most popular of these were made by the International Harvester Company and the Ford Motor Company.
Tractors with rubber tyres had already been developed in 1937. The most radical change in the design of the tractor was made by Harry Ferguson. In the 1930s he introduced the use of hydraulically-controlled implements mounted on the tractor. By the use of three linkage arms, the plough or cultivator effectively became part of the tractor.
Most modern tractors have powerful diesel engines. They have a power takeoff mechanism for driving machinery and a hydraulic lift for raising and lowering implements.
