Chinese Water Clock

A water clock is any timepiece that uses a regulated flow of liquid into or out from a vessel to measure time. Water clocks and sundials are some of the oldest time-measuring instruments. Where and when they were first invented is not known, and given their great antiquity, it may never be.

The bowl-shaped outflow is the simplest form of a water clock, and it is known to have existed in Babylon and Egypt around the year 1600 BC. Some claim that water clocks appeared in China as early as 4000 BC.

The Chinese used a very simple water clock to tell time. It consisted of a shallow pan with a very small hole in it, all resting inside a bowl filled with water. When the pan sank, a gong was rung to mark the hour.