How were water clocks used?

How were water clocks used?

Water clocks were among the earliest timekeepers that did not depend on the observation of celestial bodies. The oldest one was found in the tomb an Egyptian king, buried around 1500 BC. Later named Clepsydras (water thief) by the Greeks, who began using them about 325 BC these were stone vessels with sloping sides that dripped water at a nearly constant rate from a small hole near the bottom.

In the early-to-mid 14th century, large mechanical clocks began to appear in the towers of large Italian cities. Another advance was the invention of spring-powered clocks between 1500 and 1510 by Peter Henlein, a German locksmith from Nuremberg. Replacing the heavy drive weights permitted smaller (and portable) clocks and watches.

Henlein nicknamed his clocks ‘Nuremberg Eggs’. Although they slowed down as the mainspring unwound, they were popular among wealthy individuals due to their size and the fact that they could be put on a shelf or table instead of handing from the wall. They were the first portable timepieces.