ROEBUCK, JOHN

born 1718, Sheffield, Yorkshire, Eng. died July 17, 1794, Borrowstounness, West Lothian, Scot. British physician, chemist, and inventor, perhaps best-known for having subsidized the experiments of the Scottish engineer James Watt that led to the development of the first commercially practical condensing steam engine (1769). Roebuck devoted much of his time to chemistry, especially its practical applications. Among the most important of his early achievements in this field was the introduction of leaden condensing chambers in the manufacture of sulfuric acid (1746). The substitution of leaden chambers for glass globes, which had been employed for years, revolutionized the production process and drastically reduced costs. In 1760 Roebuck became engaged in the manufacture of iron. He established an ironworks at Carron, in Stirlingshire, Scot., where he introduced various improvements in production, including the conversion of cast iron into malleable iron by burning coke derived from bituminous coal. In utilizing coke instead of charcoal, he revived in Britain a practice that had been introduced by the ironmaster Dud Dudley (q.v.) in the early 1620s.