The lower half of the furnace with the water-baths and connecting condensation retorts. Illustration from 'Tripus Hermeticus Fatidicus' ('The Prophetical Hermetic Tripod') by Johann Joachim Becher (1635-1682) published in Frankfurt in 1689. Becher is not only famous in the history of chemistry for his theory of combustion but is notable as a technologist, miner, metallurgist and he proposed many economic schemes. He travelled much, spending a year in Cornwall, studying its mines and writing this book. He was the author of a number of books both practical and symbolic and was equally an alchemist and a chemist. Despite its arcane title, this book contains much practical chemistry and mineralogy.
© Science Museum / Science & Society Picture Library