Let us ponder on the story below :

Archimedes needed to determine if a goldsmith had embezzled gold during the manufacture of the royal crown for King Hiero I of Syracuse. How would you find out if a crown was made of gold or a cheaper alloy? How would you know if the crown was a base metal with a golden exterior? Gold is a very heavy metal (even heavier than lead, though lead has a higher atomic weight), so one way to test the crown would be to determine its density (mass per unit volume). Archimedes could use scales to find the mass of the crown, but how would he find the volume? Melting the crown down to cast it into a cube or sphere would make for an easy calculation and an angry king. After pondering the problem, it occurred to Archimedes that he could calculate volume based on how much water the crown displaced. Technically, he didn't even need to weigh the crown, if he had access to the royal treasury, since he could just compare the displacement of water by the crown with displacement of water by an equal volume of the gold the smith was given to use. According to the story, once Archimedes hit upon the solution to his problem, he burst outside, naked, and ran through the streets yelling, "Eureka! Eureka!"