Bessemer Steel
This process of making steel was patented in 1856 by the inventor, Henry Bessemer, and consists in converting the pig-iron into malleable iron, as a preliminary operation, by blowing air through the mass of molted metal, previously introduced into a converter, until all the carbon, silicon, sulphur, and phosphorus has been burned out, and then converting this into steel by the addition of a small quantity of a peculiar cast iron of known composition, called Spiegeleisen. See CONVERTER; SPIEGELEISEN; CAST STEEL; OPEN-HEARTH STEEL.