Archimedes getting into his bath, 3rd century BC, (1548).
© Science Museum / Science & Society Picture Library
Woodcut by Peter Flotner of the naked Archimedes (c 287-212 BC) stepping into his bath where he noticed that the water overflowed. He suddenly realised that the volume of water that overflowed was equal to the portion of his body that had been immersed. It is said he then leapt out and ran naked through the streets of Syracuse shouting 'Eureka!' ('I have found it'). After further experiments, he concluded that the buoyant force on an object is equivalent to the weight of water displaced by that object. This is now called 'Archimedes' Principle' or the 'Principle of Buoyancy'. Illustration from 'Vitruvius Teutsch', the first German translation of 'De architectura' (Of architecture) by the Roman architect and engineer Vitruvius Pollio (1st century BC), published in Nuremberg in 1548.