Early Egyptian water-clock

From Object Wiki

Cast of early Egyptian water-clock
Manufacturer	(unknown)
Production years	1415-1380 BC
Production location	Karnak Temple, Upper Egypt

The original of this cast was found at Karnak Temple, Upper Egypt, in 1904 and dates from the reign of King Amenhotep III, 1415-1380 BC; it is now in Cairo Museum. It is made of alabaster, and was probably used for indicating the passage of hours of the night.

[edit] How it works

In use the vessel was filled with water, which leaked out slowly from a small hole near the bottom, and the time was indicated by the level of water within. With a vessel of this shape the water-level falls fairly uniformly, for the more rapid flow when near full is compensated by the greater cross-section of the vessel near its top, a greater outflow of water then being required to produce a given decrease of level. At this epoch it was customary to divide the periods of daylight and of darkness each into 12 ‘temporal’ hours, so that the length of an hour of day differed from that of an hour of the night (except at the equinoxes) and both varied according to the season of the year. A separate scale of time was therefore required for each month of the year, and there are accordingly 12 series of dots marked on the inner surface of the vessel, the name of the month to which each scale refers being marked on the rim of the vessel above the scale in question.

[edit] Memories

Do you remember stories about the Egyptian water-clock? Add your memories.

[edit] In the Science Museum's Records

Inv. No: 1923-48