The replica of this special form of the water clock consists of a hollow copper ball with a long neck attached to it, which has a hole at the top. The ball rests on a holder above a clay inlet vessel. The device was named Klepsydra, which means water thief. There are several small holes on the underside of the hollow sphere, actually a water strainer. It is filled by putting it on the water. After a while it is pulled out, holding the opening at the top of the neck closed with a finger.
The device was also used as a timepiece, e.g. B. used for speaking times. At the court, two bullets were used for the prosecutor and the defense attorney, one of which was sealed with beeswax.
The Greek natural philosopher and statesman Empedocles (490-430 BC) used this device to detect air as a substance.
