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 instructor Drill Instructor Ribbon, and the Army's Drill Sergeant Identification Badge. It may be taken offensively by U.S. Marine Corps Drill Instructors to be referred to as 'Drill Sergeants', which is strictly an Army term in the American military, just as Marines may take offense to being called "soldiers". This is considered to be a grievous insult if done intentionally. The only acceptable address of a drill instructor by a recruit is "sir", "ma'am" or "(senior) drill instructor (Rank) (last name)". At Officer Candidates School (OCS), candidates are instructed by Drill Instructors who have already served a tour at one of