...our hours at the equinoxes, when days and nights are equal; in summer they were longer and in winter shorter than at the equinoxes. The Chaldeans, Syrians, Hindoos, Persians, Egyptians, Greeks, and Romans thus divided the daylight into twelve periods or hours, while the civil day was the solar day and had twenty-four hours. The dial of Ahaz may have had a vertical gnomon on the upper one of a series o...