Ramesside Star Clock

Definition

The Ramesside star clock is the New Kingdom Egyptian night-timekeeping system preserved in the burial chambers of three 20th-Dynasty kings — Ramesses VI, VII, and IX (about 1145-1111 BCE). It works by transit: you watch a named star cross the meridian — the line due south, where a star climbs highest — rather than catching it rising on the horizon. Each table comes with a drawing of a seated man facing you, the 'target figure', and the star's position is read off against a part of his body — left ear, left shoulder, the centre over his heart, and so on.

In Tradition

Egyptologists — Clagett, and Neugebauer and Parker, who edited the clock in full — treat it as a later, transit-based refinement of the earlier diagonal star clocks that timed stars by their rising. The seated-figure grid uses seven vertical lines: the meridian over the heart, plus three to each side through the eyes, ears, and shoulders. Neugebauer and Parker judged the scheme awkward, yet it was carved to mark the night-hours 'for all eternity' on the tomb ceilings.

In Practice

An hour-priest sat facing a second observer — the living version of the seated target figure — and noted which named star crossed the meridian, or one of the six close lines beside it, level with a given body landmark. That told him the hour of the night. The clock is laid out as 24 semimonthly tables, one for the first half and one for the second half of each civil-year month, each giving the transits at the start of the night and at the end of each of the 12 night-hours. Neugebauer and Parker found the table arithmetic does not cleanly track the real night lengthening and shortening through the year, so they had to reconstruct it editorially; from the date given for Sirius crossing the meridian at the start of the night, they fixed the clock's design to about 1470 BCE, older than the tombs that preserve it.

Historical Origin

Four copies survive, all in 20th-Dynasty royal tombs in the Valley of the Kings: Ramesses VI (two copies, KV 9), Ramesses VII, and Ramesses IX (about 1145-1111 BCE). The clock's design is dated to about 1470 BCE from the Sirius culmination in its Table 12. Foundational edition: Neugebauer and Parker, Egyptian Astronomical Texts Vol II: The Ramesside Star Clocks (1964); presented again in Clagett, Ancient Egyptian Science Vol II, Document III.14 (1995).

Definition

In Tradition

In Practice

Historical Origin

Further Reading