A clepsydra is an ancient timekeeping device that measures time by the gradual flow of water into or out of a container. It is considered one of the oldest timepieces, with evidence of its use dating back to 6th century BC Mesopotamia.
The word “clepsydra” comes from the Greek words klepsydra, which literally means “water thief”. Clepsydras were widely used in ancient Egypt, Greece, Rome, and China. They were used for a variety of purposes, including timing public speeches, regulating water flow, and even navigation.
There are two main types of clepsydras: inflow clepsydras and outflow clepsydras. Inflow clepsydras work by measuring the amount of water that flows into a container over time. Outflow clepsydras work by measuring the amount of water that flows out of a container over time.
Clepsydras were not very accurate timekeepers, as the rate of water flow could be affected by temperature, humidity, and the size and shape of the container. However, they were a valuable tool for keeping track of time in a world before mechanical clocks.
The development of mechanical clocks in the 14th century made clepsydras obsolete. However, they remain a fascinating example of early human ingenuity.