History of the horse in Britain drawn by two horses, the "Dutch plough", was used in eastern England; this was followed in 1730 by the lightweight Rotherham plough, an unwheeled, or "swing" plough. It was advertised as reducing ploughing times by a third, or using a third less horsepower for the same ploughing time. The improved seed drill and horse-hoe were invented by Jethro Tull in 1731; but it took more than 100 years for these designs to come into common use. The earliest horse-powered threshing machines, which were installed permanently in barns, were developed towards the end of the 18th century. The use of fast
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