Temple doors opened by fire on an altar, 1589.

Engraved diagram showing a method whereby, 'on lighting a fire, the doors shall open spontaneously, and shut again when the fire is extinguished'. A system of heated liquid, chains, pulleys, weights and siphons, enables the doors to be opened automatically as long as a fire is burning. Illustration from 'Gli artifitiosi et curiosi moti spiritali di Herrone' (commonly called 'Pneumatics') by Hero of Alexandria, published in Ferrara in 1589.