Melting cast iron in a furnace by charging it with charcoal, 1734.
© Science Museum / Science & Society Picture Library
Engraving showing 'the ordinary furnace in which cast iron is melted by charging it together with charcoal, without placing it in a special crucible'. Like many eighteenth century technical illustrations the plate is separated into two: the upper part shows artisans using bellows to heat one of these furnaces, in which the iron is melted. It also shows how iron melted in a second furnace is being poured into moulds. Tools and equipment used in the proces are shown below. Illustration from 'Regnum subterraneum sive minerale de ferro' (The Subterranean or Mineral Kingdom in respect to Iron) by Emanuel Swedenborg (1688-1772) published in Dresden in 1734.