n.
born June 22, 1792, Shettleston, Lanark, Scot.
died Jan. 18, 1865, Queenshill, Kirkcudbright
Scottish inventor.
Working at the Glasgow Gasworks (181747), he introduced the use of a hot-air blast for the smelting of iron ore. It had been believed that a blast of cold air was the most efficient smelting method (see William Fairbairn ); Neilson demonstrated that the opposite was true, patenting his idea in 1828. Use of the hot blast tripled iron output per ton of coal, permitted iron to be recovered from lower-grade ores, and made possible the efficient use of raw coal and lower grades of coal instead of coke and the construction of larger smelting furnaces.