Archimedes of Syracuse (c. 287-212 BC), Greek mathematician, physicist and engineer. Archimedes is regarded as the greatest mathematician of ancient times. He used geometry to measure the volume of solids, and calculated an approximation of pi correct to 3 decimal places. He is said to have discovered the Archimedes principle whilst taking a bath. This principle states that a body immersed in a fluid experiences a buoyant force equal to the weight of the displaced fluid. Engraving from Vies des Savants Illustres (1877).