Egyptian Sundial

A stick in the ground that casts a shadow as the sun moves across the sky was mankind’s first timepiece: the sundial, or shadow clock. A sundial measures time as the pointer casts a shadow on a scale with reference lines – the first “dial” for telling time. Sundials were in widespread use in the ancient Egypt and Babylonia since they were most effective in sunny climates. The oldest known sundial was found in the Valley of the Kings dating from 1500 BC, but there is no doubt that the concept goes back millennia. From their earliest development, a sophisticated understanding of astronomy was necessary. The sundial is our earliest evidence of man’s comprehension of the heavens.

Sundials were less effective in cloudy climates, and only useful from sunrise to sunset. The dial reflects the period between sunset and sunrise. Adjustments were made for different latitudes. This was a sophisticated technology. A sundial was the most reliable means of determining the time until the mechanical clock became an accurate precision instrument by the 19th century. Sundials were often provided to purchasers of clocks to ascertain the exact time to set their clocks.