View of a Bessemer converter blowing iron into steel 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. The conversion process, known as "the blow," occurs as impurities are removed and skimmed off of the molten iron by means of oxidation and the required steel is formed. This photograph is one of a set of fourteen stereographs detailing the production of iron and steel by various processes.