Henry Bessemer patents his steel-making process

In 1856 the English inventor Henry Bessemer announced and patented a method for making steel cheaply by blowing air through molten pig iron in a pear-shaped vessel called a converter, which burns out impurities, such as carbon, in about 20 minutes, instead of the days needed before. The cost of steel fell from about 40 to 60 pounds a ton to 6 or 7 pounds. The American William Kelly had independently found the same idea. Early steel was brittle because of phosphorus in some ores, a problem solved in the 1870s. Cheap steel made possible railways, skyscrapers, bridges and ships, and the iron and steel industry in Britain, Germany and the United States.

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