View of several workers forming the bottom of a Bessemer converter at an unknown manufacturing plant. The Bessemer converter takes its name from the "Bessemer process," an inexpensive industrial method for the mass-production of steel from molten pig iron. Named for Sir Henry Bessemer (1813-1898), the Bessemer process involves the removal of impurities from molten iron by means of oxidation in order to form steel. This photograph is one of a set of fourteen stereographs detailing the production of iron and steel by various processes.