in chronology, an aliquot part of a natural day, usually a 24th, but sometimes a 12th. The origin of the word hora, or ἡρα, comes, according to some authors, from a surname of the sun, the father of hours, whom the Egyptians call Horus. Others derive it from the Greek ἐπίστημον, to terminate, distinguiā, &c. Others from the word ὀρυζον, urine; holding, that Trismegistus was the first that settled the division of hours which he did from observation of an animal consecrated to Serapis, named cynocephalus, which makes water 12 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 24th part of the natural day, ornythemeron; or the duration of the 24th 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. It is divided into 60 minutes; the minute into 60 seconds, &c.

The division of the day into hours is very ancient; as is shown by Kircher, Oedip. Ægypte, tom. ii. p. ii. claff. vii. c. 8.: though the passages he quotes from Scripture do not prove it.—The most ancient hour is that of the 12th part of the day. Herodorus, lib. ii. observes, that the Greeks learnt from the Egyptians, among other things, the method of dividing the day into twelve parts.—The astronomers of Cathaya, &c. Bishop Beveridge observes, still retain this division. They call the hour chag; and to each chag give a peculiar name, taken from some animal: The first is called zeth, "moule;" the second, chiu, "bullock;" the third, zem, "leopard;" the fourth, mau, "hare;" the fifth, chiu, "crocodile," &c.

The division of the day into 24 hours, was not known to the Romans before the first Punic war.—Till that time they only regulated their days by the rising and setting of the sun. They divided the 12 hours of their day into four, viz. prime, which commenced at six o'clock; third, at nine; sixth, at twelve, and none, at three. They also divided the night into four watches, each containing three hours:

HOURS, Horæ, in the ancient mythology, were certain goddesses, the daughters of Jupiter and Themis; at first only three in number, Eunomia, Dice, and Irene, to which were afterwards added two more, Carpo and Thallote.

Homer makes them the doorkeepers of heaven. Ovid allots them the employment of harnessing the horses of the Sun:

Jungere equos Titan velocibus imperat Horis.

And speaks of them as standing, at equal distances, about the throne of Sol:

—et, positæ spatius equilibus, Horæ.

The poets represent them as dressed in fine coloured or embroidered robes, and gliding on with a quick and easy motion.

Hours, Horæ, in the Romish church, are certain prayers performed at stated times of the day; as matins, vespers, lauds, &c. The lesser hours are, prime, tierce, sixth, and none. They are called hours, or canonical hours, as being to be rehearsed at certain hours prescribed by the canons of that church, in commemoration of the mysteries accomplished at those hours. These hours were anciently also called curfew, curfus: F. Mabillon has a dissertation on them, entitled, De Curfu Gallicano.

The first constitution enjoining the observation of the canonical hours is of the ninth century, being found in a capitular of Heito bishop of Basil directed to his curates, importing that the priests shall never be absent at the canonical hours either by day or night.