Chromo graph

[Gr. chroma, color, and grapho, to write. A colored engraving. by, chromo-lithography. graphy to oil-printing. See LITHOGRAPHY. "Transmit a true chronology to succeeding ages."- Holder . Chronometer, n. [Gr. chronos , and metron , measure.] A watch of peculiar construction, and great perfection of workmanship, used for determining geographical longitudes, or other purposes where time must be measured with extreme accuracy. The C. differs from the ordinary watch in the principle of its escapement, which is so constructed that the balance is entirely free from the wheels during the greater part of its vibration; and also in having the balance compensated for variations of temperature. Marine C. generally beat half-seconds, and are hung in gimbals, in boxes about 6 or 8 inches square. The pocket-C. does not differ in appearance from the ordinary watch, excepting that it is generally a little larger. C. are of immense utility in navigation, and ships going on distant voyages are usually furnished with several, for the purpose of checking one another, and also to guard against the effects of accidental derangement in any single one. The accuracy with which C. have been found to perform is truly astonishing; the error in the mean daily rate in a two-months' voyage sometimes not exceeding two or three seconds. (Mus.) An instrument to measure the time of a musical movement. Chronometric, Chronometrical, a . Pertaining to a chronometer; measured by a chronometer. Chronometry, n. [Fr. chronométrie.) The art of measuring time; the measuring of time by periods or divisions.