Anaphoric Clock

• The anaphoric clock was described by Vitruvius and was probably a Water Clock with a Disc representing the Sky and Zodiac cycle.
• The Disc would have rotated behind a bronze grid containing circles and curves which defined the months of the year and hours of the day.

Vitruvius (88-26 BCE)

• Vitruvius described an Anaphoric Clock in Alexandria in Book IX, Chap.8. 8-15, of his ‘Architectura’.
• It was probably a Water Clock, identical or certainly very similar to the Tower of Winds in Athens.
• The clock had a rotating field of stars behind a wire frame which indicated the time of day.
• The wire frame and star map were constructed using Stereographic Projection.
• Other examples have been found in the Roman Empire dating to the first to third century CE.