Fragment of a basalt water clock
Said to be from Tell el-Yahudiya,
Egypt
Macedonian Dynasty, around 320
BC
With the names of Philip Arridaeus
On the death of Alexander the Great in 323 BC, the throne of Macedon passed to his half-brother Philip Arridaeus (323-317 BC). He left several monuments in Egypt, of which the most visited is the sanctuary of the Temple of Amun at Karnak. This water-clock is another object which bears his name.
Water-clocks, which measured time by the gradual evacuation of their contents through a hole at the base, were a way of keeping track of the passing of the 'hours' in which Egyptians divided the day and night.
Both day and night were divided into twelve hours each. However, as the length of day and night varied with the seasons, it was necessary to calibrate the clocks each month. For example, the twelve daylight hours would each have to be shorter in the winter months, to fit them all between dawn and dusk.
The
gods
The clock continued to be used into the Roman period (after 30 BC) as can be seen by some Latin letters indicating months on the top.
G. Langmann, G. Hölbl and M. Firneis, 'Die ägyptische Wasserauflaufuhr aus Ephesos', Jahresheften des österreichisc, 55 (1984), p. 4-67
S. Quirke and A.J. Spencer, The British Museum book of anc (London, The British Museum Press, 1992)

