Clock

A machine composed of a combination of wheels, which are moved either by weights or by a spring, and which measures time, indicating the same by hour, minute, and second hands moving around the dial, or face of the instrument, on which numerals are painted.

Astronomical Clock. A pendulum clock of superior workmanship and great accuracy. It shows sidereal (star) time, and when the first point of Aries is on the meridian it indicates oh. om. os.

Mean Solar Clock. A timepiece which shows mean solar or civil time.

Sidereal Clock. An astronomical clock.