English Dictionary: sidereal clock | by the DICT Development Group |
2 results for sidereal clock | |
From Webster's Revised Unabridged Dictionary (1913) [web1913]: | |
Sidereal \Si*de"re*al\, a. [L. sidereus, from sidus, sideris, a constellation, a star. Cf. {Sideral}, {Consider}, {Desire}.] 1. Relating to the stars; starry; astral; as, sidereal astronomy. 2. (Astron.) Measuring by the apparent motion of the stars; designated, marked out, or accompanied, by a return to the same position in respect to the stars; as, the sidereal revolution of a planet; a sidereal day. {Sidereal clock}, {day}, {month}, {year}. See under {Clock}, {Day}, etc. {Sideral time}, time as reckoned by sideral days, or, taking the sidereal day as the unit, the time elapsed since a transit of the vernal equinox, reckoned in parts of a sidereal day. This is, strictly, apparent sidereal time, mean sidereal time being reckoned from the transit, not of the true, but of the mean, equinoctial point. | |
From Webster's Revised Unabridged Dictionary (1913) [web1913]: | |
Clock \Clock\, n. [AS. clucge bell; akin to D. klok clock, bell, G. glocke, Dan. klokke, Sw. klocka, Icel. klukka bell, LL. clocca, cloca (whence F. cloche); al perh. of Celtic origin; cf. Ir. & Gael. clog bell, clock, W. cloch bell. Cf. {Cloak}.] 1. A machine for measuring time, indicating the hour and other divisions by means of hands moving on a dial plate. Its works are moved by a weight or a spring, and it is often so constructed as to tell the hour by the stroke of a hammer on a bell. It is not adapted, like the watch, to be carried on the person. 2. A watch, esp. one that strikes. [Obs.] --Walton. 3. The striking of a clock. [Obs.] --Dryden. 4. A figure or figured work on the ankle or side of a stocking. --Swift. Note: The phrases what o'clock? it is nine o'clock, etc., are contracted from what of the clock? it is nine of the clock, etc. {Alarm clock}. See under {Alarm}. {Astronomical clock}. (a) A clock of superior construction, with a compensating pendulum, etc., to measure time with great accuracy, for use in astronomical observatories; -- called a regulator when used by watchmakers as a standard for regulating timepieces. (b) A clock with mechanism for indicating certain astronomical phenomena, as the phases of the moon, position of the sun in the ecliptic, equation of time, etc. {Electric clock}. (a) A clock moved or regulated by electricity or electro-magnetism. (b) A clock connected with an electro-magnetic recording apparatus. {Ship's clock} (Naut.), a clock arranged to strike from one to eight strokes, at half hourly intervals, marking the divisions of the ship's watches. {Sidereal clock}, an astronomical clock regulated to keep sidereal time. |