The process of measuring the volume of an irregularly shaped object is the most celebrated of Archimedes’ inventions. The inventor was called upon by King Hiero II, the King of Syracuse, to verify, if his votive crown was created using entirely pure gold or whether the goldsmith had cheated him by substituting some silver for gold. Archimedes was asked to find the answer, without causing any harm to the crown, and, therefore, the crown could not be melted into a more evenly shaped body for determining its density.
While enjoying a bath in his bathtub, on a sunny day, Archimedes suddenly observed that the level of water in the tub rose and some of the water flowed out, as he stepped into it. This is when it struck him that he could use the same method to calculate the crown’s density. Upon this discovery, he became so excited that Archimedes came out of the bathtub and ran naked through the streets of Syracuse, shouting ‘Eureka! Eureka!,’ which means ‘I have found it.’ Since, Density = Mass/Volume, he knew that in order to find the solution for King Hiero, he will have to match the density of the crown with that of pure gold. Conducted with great success, the experiment revealed that the dishonest and audacious goldsmith had indeed mixed silver to cheat the King, but was ultimately not successful.
This discovery of how to ascertain the volume of objects, with an irregular shape, is well-known as Archimedes’ Principle or the Law of Buoyancy. With the passage of time, June 14th came to be known as the International Bath Day and it commemorates his great and unique discovery in the bathtub.