Water Clocks

Abstract

Abstract Egyptian water clocks were among the earliest timekeeping devices that did not depend on the observation of celestial bodies. One of the oldest was found in the tomb of the Egyptian pharaoh, Amenhotep I, buried around 1500 B.C.E . As explained by the National Institute of Standards and Technology Physics Laboratory, early water clocks were named clepsydras (“water thieves”) by the Greeks. The Greeks began using clepsydras about 325 B.C.E . Clepsydras were stone vessels with sloping sides that allowed water to drip at a nearly constant rate from a small hole near the bottom. The drip‐drip sound of water dropping from a water clock was an ancient precursor to the ticktock sound emitted by certain mechanical clocks invented in later times. Water clocks were replaced by the invention of mechanical clocks about 700 years ago.