Engraved diagram showing four naked smiths rhythmically hitting iron on an anvil. On the right is a furnace, with a water supply on the left. Below is a system of wheels, chains and pulleys. Illustration from 'Gli artifitiosi et curiosi moti spiritali di Herrone' (commonly called 'Pneumatics') by Hero of Alexandria, published in Ferrara in 1589.
© Science Museum / Science & Society Picture Library