Archimedes screw

So the Archimedes screw was obviously invented by Archimedes. It was used to get water from a lake or just water up onto plants. It works like this. Think of a spiral staircase, then think of you on the stairs, you are not moving, but then the staircase starts winding upward. Then there are these stoppers that don't let the water go down. Then at the top it lets the water out and keeps doing the same cycle over and over again. Archimedes was a famous scientist and here is a little story about him.

So the king during that time liked Archimedes a lot because he was smart and could solve problems for him. One of these problems was about a crown. He had asked one of his servants to make him a crown of gold. But he was worried that it wasn't all gold and asked Archimedes to come and solve the problem. Archimedes came but didn't solve the problem immediately, instead he went to his house to think about it. He was in his bathtub and then he saw how the water rose when he went in. 

"EUREKA!"he cried  and ran into the streets naked. He had solved the problem. This was called bouncy. You may have heard of it. This what he found out. He put a piece of gold the exact volume as the crown. The crown was more dense so it meant that it was not pure gold it was only leafed.