Time #2

Water Clock

Originally, sundials were used as timekeeping devices throughout the world, but they are useless at night and in cloudy weather.

A water clock, also known as a clepsydra, is a clock that measures time using water. The invention of the water clock was therefore a significant advancement.

This clock consists of two reservoirs.

There are types that measure how much water remains in the first reservoir and types that measure how much water has flown into  the second reservoir.

In the latter type, the water drips slowly from one reservoir to the other. As the water level changes, the float rises. By means of a rod with teeth and a gear, the hand turns and the time is indicated.