The water clock has three parts.On the left is a tank holding water.This tank has a narrow opening through which water drips into a second container,also a tank.Inside the second tank is a floating object,to the end of which is attached a long pole with an arrow.On the right is a cylinder with the numbers one to twelve written on it.As the water from the tank on the left drips into the seco (共 658 字) [阅读本文] >>