Boiler water purification, 19th century. Illustration of a vertical section through a device designed to treat water for use in boilers. This process, known as boiler water treatment, removes of modifies impurities or chemicals in the water that could damage a boiler. This design was produced by French inventor Henri Desrumaux. Artwork from 'Chaudieres et Machines a Vapeur' (1911) by French civil engineer Max de Nansouty (1854-1913), part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.