James Smith (3 January 1789, Glasgow – 10 June 1850, Kingencleuch near Mauchline, age 61)^[1] was a Scottish inventor whose inventions include a reaping machine, a subsoil plough and the first endless chain of flats for carding.

Smith's father, a self-made Glasgow businessman, died when he was two months old; his mother went to live with her brother, a friend and pupil of Richard Arkwright, and managing partner of cotton-works at Deanston.^[1] Smith attended Glasgow University before entering his uncle's factory and becoming manager aged 18.^[1] Aged 24, his invention of the reaping machine won him a medal from the Imperial Agricultural Society of St Petersburgh.^[1] In 1823 Smith came into possession of his uncle's farm, and set about systematically draining the soil and working it with a subsoil plough. In 1831 he published his agricultural recommendations as a small pamphlet, Thorough Draining and Deep Working, which attracted attention in the agricultural crisis of 1834.^[1]

Smith also introduced mechanical innovations in spinning: in 1834 he improved Archibald Buchanan's self-stripping card, filing a patent (British patent no. 6560) for fixing the flat cards on an endless chain, allowing them to be regularly cleaned.^[2]

Smith was appointed by Robert Peel to the Commission into the sanitation and health of manufacturing towns, which led to the 1848 Public Health Act: Smith pressed to make liquid manure useful to agriculture.^[1] Smith was also an active member of the Royal Agricultural Improvement Society of Ireland, and a member of the Glasgow Philosophical Society, contributing papers to their Transactions.^[1]