One day in ancient Greece, King Hiero asked a crown（王冠）maker to make him a golden crown. At first, he was very happy with it.
"It's a nice crown, isn't it? "he asked his men. Later, however, he began to wonder whether it was a real golden crown or not. "Is it made completely of gold? "he asked himself. He sent it to Archimedes and asked him to find out the truth.
"This problem seems difficult to solve. What should I do? thought Archimedes.
Archimedes was still thinking about this problem as he filled his bath with water. When he got into the bath, some water ran over.
"That's it!" shouted Archimedes.
"I know how to solve the king's problem!"
Archimedes went straight to the palace to see the king. First, he weighed the crown and asked the king for some gold of the same weight.
Next, he put two pots into two big bowls and filled both pots with water. He put the gold into one pot, and some water ran into the bowl. Then he put the crown into the other pot. This time, even more water ran into the bowl.
"Look at this," said Archimedes to King Hiero. "A crown made completely of gold displaces （排出） less water than a crown made of gold and another metal （金属）. This crown displaced , so I'm certain that it's not completely made of gold. "
"The crown makertrickedme, didn't he? What a bad man he is!" shouted King Hiero. He then sent the crown maker to prison （监狱）.
