Vitruvius related the famous story about Archimedes and his detection of adulterated gold in a royal crown. When Archimedes realized the volume of the crown could be measured exactly by the displacement created in a bath of water, he ran into the street with the cry of "Eureka!", and the discovery enabled him to compare the density of the crown with pure gold. He showed the crown had been alloyed with silver, and the king was defrauded.