pocket chronometer

Webster's Dictionary (GCIDE)

1.An instrument for measuring time; a timekeeper. [1913 Webster]

2.A portable timekeeper, with a heavy compensation balance, and usually beating half seconds; -- intended to keep time with great accuracy for use an astronomical observations, in determining longitude, etc. [1913 Webster]

3.(Mus.) A metronome. [1913 Webster]

Box chronometer. See under Box.

Pocket chronometer, a chronometer in the form of a large watch.

To rate a chronometer. See Rate, v. t. [1913 Webster] Chronometric