Industrial Revolution sectors of the economy. However, per-capita food supply in Europe was stagnant or declining and did not improve in some parts of Europe until the late 18th century. Industrial technologies that affected farming included the seed drill, the Dutch plough, which contained iron parts, and the threshing machine. Jethro Tull invented an improved seed drill in 1701. It was a mechanical seeder which distributed seeds evenly across a plot of land and planted them at the correct depth. This was important because the yield of seeds harvested to seeds planted at that time was around four or five. Tull's seed
Drill bit was sold only by the Unibit Corporation in the 1980s until the patent expired, and was later sold by other companies. Unibit is a trademark of Irwin Industrial Tools. Although it is claimed that the stepped drill was invented by Harry C Noakes it was in fact first produced by Bradley Engineering, Wandsworth, London in the 1960s and named the Bradrad. It was marketed under this name until the patent was sold to Halls Ltd.uk by whom it is still produced. Hole saws take the form of a short open cylinder with saw-teeth on the open edge, used for making