celtgreeklatin A #sundial is a device that indicates time by using a light spot or shadow cast by the position of the #Sun on a reference scale. The earliest household #clocks known, from the archaeological finds, are the sundials (1500 BCE) in Ancient #Egypt and ancient Babylonian astronomy. The #ancient #Greeks developed many of the principles and forms of the sundial. Sundials are believed to have been introduced into #Greece by Anaximander of Miletus, c. 560 BCE. The #Romans adopted the Greek sundials, and the first record of a sundial in #Rome is in 293 BCE according to #Pliny. Source: Wikipedia 📷 A Roman period sundial of the Greek hemispherical type. Author: Mark Cartwright (CC BY-NC-SA 4.0)