Named for Eureka, an expression of joy after making a discovery. According to a story that is probably apocryphal, Hiero II asked the Greek physicist Archimedes (287–212 B.C.) {see planet  (3600)} to judge whether a crown contained pure gold or gold mixed with silver. After some consternation he found the answer while taking a bath: the weight of the crown in and out of water would allow the density to be determined, and hence the proportions of silver and gold. Thus Archimedes’ principle was born, that a solid body surrounded by liquid is supported by a force equal to the weight of the liquid displaced. Archimedes was so thrilled by the revelation that he leaped out of the bath and dashed down the street, presumably still nude and shouting “Eureka! Eureka!” (I have found it!) (M 21134) _ _.