For example, an iron cube weighing a kilogram will disperse some water. But an aluminums cube of the same weight will displace more water than the iron cube.

Archimedes knew all these theories. Using this as the basic knowledge, Archimedes worked out a plan to find out the purity of the crown.

Archimedes took two bowls. He filled them with water to the brim. Then he placed each bowl separately in the middle of the large vessels. He placed the crown in one bowl. Water overflowed. It collected at the bottom of the outer vessel. Then he took a cube of pure gold. This cube of gold was equal in weight to the crown. He kept this gold cube in the middle of the second bowl. Here also water overflowed. Water got collected at the bottom of the outer bowl.