Clepsydra

Hji ie«j/ lou, the water-clock, an apparatus for marking time by the leakage of water from an arrangement of jars. There was formerly one called T'ung lou hu in the Drum Tower at Peking; and there is one still in use at Canton, said to be eight centuries old. It consists of four copper jars placed on steps, and the water trickles down to the lowest, where a floating indicator marks the hour. It is arranged to run for twelve hours.