HOURL, in Chronology, an aliquot part of a natural day, usually a twenty-fourth, but sometimes a twelfth. Originally the word hora, or hour, comes, according to some authors, from a surname of the sun, the father of hours, whom the Egyptians called Horus. But others derive it from the Greek ἰσχύς, to terminate, or distinguish; and others again from the word ἴσος, urine, conceiving that Trismegistus was the first who settled the division of hours, from observing an animal consecrated to Serapis, named cynocephalus, which made water twelve times a day, and as often in the night, at equal intervals.
An hour with us is a measure or quantity of time, equal to a twenty-fourth part of the natural day, or nycthemeron; or the duration of the twenty-fourth part of the earth's diurnal rotation. Fifteen degrees of the equator answer to an hour, though not precisely, but near enough for common use. The hour is divided into sixty minutes, the minute into sixty seconds, and so on. The most ancient hour is that of the twelfth part of the day. Herodotus, (lib. ii.) observes that the Greeks learned from the Egyptians, amongst other things, the method of dividing the day into twelve parts. The division of the day into twenty-four hours was not known to the Romans before the first Punic war. Until that time they only regulated their days by the rising and setting of the sun. They divided the twelve hours of their day into four, namely, prime, which commenced at six o'clock; third, at nine; sixth, at twelve; and nine, at three. They also divided the night into four watches, each containing three hours.