Henry Bessemer
Henry Bessemer invented a process that made steel cheap and transformed industrial construction. Born in Hertfordshire in 1813, the son of a typefounder and engineer, he had no formal scientific training and worked in his father's business, developing an early talent for mechanical improvisation. His first successes had nothing to do with metal. He devised a method of perforating date stamps to prevent the reuse of government revenue stamps, receiving no reward for it; and he worked out a machine process for making gold powder for paint, which had been produced by hand in Nuremberg at great expense. He kept the method secret rather than patenting it, and it made him wealthy for forty years. During the Crimean War he designed a rotating artillery shell, and was told that existing cast iron guns were not strong enough to fire it. That sent him to the problem of producing better metal. Pig iron from a blast furnace contains too much carbon and is brittle; removing it by the puddling process was slow and produced small quantities at high cost. His converter, patented in 1856, blew cold air up through molten pig iron in a tilting vessel. The oxygen burned out the carbon and silicon, and the reaction generated enough heat to keep the metal liquid without additional fuel. Twenty-five tonnes could be processed in about twenty minutes. Early licensees failed because the process could not remove phosphorus, and Bessemer had used phosphorus-free ore without realising it. Robert Mushet's addition of spiegeleisen fixed the carbon control. Steel prices fell by around eighty per cent. He was knighted in 1879 and died in 1898.
- Lived: 1813 CE – 1898 CE
- Nationality: British
- Roles: engineer, inventor, industrialist
