Post by geriatrix on Sept 23, 2015 14:01:40 GMT
The clepsydra or water clock is an ancient timekeeper that operates by measuring the regulated flow of liquid into or out of a vessel. It is believed to have been used in Egypt as early as 2,000 BCE, making it one of the earliest known time-measurement devices. Early water clocks were calibrated with a sundial and they remained the most accurate timekeeping devices until the invention of the pendulum clock in the 17th Century.
