History of agriculture the New Leicester sheep. Machines were invented to improve the efficiency of various agricultural operation, such as Jethro Tull's seed drill of 1701 that mechanised seeding at the correct depth and spacing and Andrew Meikle's threshing machine of 1784. Ploughs were steadily improved, from Joseph Foljambe's Rotherham iron plough in 1730 to James Small's improved "Scots Plough" metal in 1763. In 1789 Ransomes, Sims & Jefferies was producing 86 plough models for different soils. Powered farm machinery began with Richard Trevithick's stationary steam engine, used to drive a threshing machine, in 1812. Mechanisation spread to other farm uses through the
Seed drill hopper filled with seeds arranged above a series of tubes that can be set at selected distances from each other to allow optimum growth of the resulting plants. Seeds are spaced out using fluted paddles which rotate using a geared drive from one of the drill's land wheels—seed rate is altered by changing gear ratios. Most modern drills use air to convey seed in plastic tubes from the seed hopper to the coulters—it is an arrangement which allows seed drills to be much wider than the seed hopper—as much as 12 m wide in some cases. The seed is metered