Caption:

Engraving with a working scene above showing the process, and tools and equipment at the bottom. The furnace is shown in two positions at the top: upright, for when the metal is being melted; and tilted, for when the molten metal is poured into a mould. The furnace is shown in detail at the bottom. 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. This book formed part of his 'Opera philosophica et mineralia' (Philosophical and Logical Works), which dealt with the creation of the world, and drew on Swedenborg's interpretations of metallurgy and metaphysics.