HOUNS'LOW HEATH. A region west of the township of Hounslow, London, covering in 1546 an extent of 4293 acres. It was formerly notori ous as the resort of highwaymen, and it was cus tomary to leave the bodies of those who had been executed hanging on gibbets along the road. In 1686 James II. established a camp on the Heath for the purpose of overawing the Londoners. Extensive barracks were erected in 1793, and part of the land is now occupied by powder-mill:. The region is in great part under cultivation and inclosed.
HOUR (Al". are, OF. ure, )care, ore, pore, Fr. heure, from Lat. Nora, from Gk. ciipa, hour, sea son). A measure of time equal to one twenty fourth part of a day (q.v.). As there are two kinds of days, the solar and sidereal, so there are two kinds of hours, the solar and sidereal. The latter is shorter than the former by 9.856
solar seconds. Sidereal time is used by aAron oiners in discussing the motions of the stars; but in the ordinary affairs of life solar time only is employed. Twenty-four ordinary solar ]lours correspond to an interval of time equal to the mean or average period elapsing between two successive returns of the sun to any given meridian. The first hour of the civil or ordinary day is numbered XII, and commences at mid night. The following hours are then numbered 1, 11, etc.. up to XI", which number is attached to the hour beginning at noon. In Italy, until November, 1693, when the standard time was adopted, 'time was reckoned from sunset con tinuously, from 1 to 24 hours. On the Continent, France is to-day the only country that is outside the time-zone, i.e. that uses local time.