Ancient Egyptian Timekeeping: The Water Clock

The ancient Egyptian civilization, first springing up near the Nile delta around 5000 BC, had a very substantial understanding of time. It was the annual flooding of the Nile River that influenced ancient Egyptians to begin to record time. They needed to record time in order to determine when to plant and when to harvest crops. This relationship between the ancient people and nature reflected their spirituality, since they viewed the Nile as a pathway to the afterlife.
Ancient Egyptians used sundials to observe the 12 daytime hours, but in oder to tell time at night, a new method was needed. Under the reign of Ahmenhotep I, a man known as Amenemhat created a water clock. The water clock, also called a clepsydra, was a essentially a funnel made of alabaster that stood about 95 centimeters high. It had 12 sections carved into it, each with 11 perforations lining it. When filled with water, the clepsydra would take 12 hours to drain through a tiny hole in its base. To tell time, one had to observe the water level in the clock, and read the time according to the closest perforation. The timekeepers were priests and astronomers, who needed to know when to plan religious rituals, which were of utmost importance to the ancient civilization.