or mariner's Compass, an instrument whereby the ship's course is determined. See Navigation.

Azimuth Compass. See Navigation.

Compass dials, are small horizontal dials, fitted in brass or silver boxes, for the pocket, to show the hour of the day, by the direction of a needle, that indicates how to place them right, by turning the dial about, till the cock or style stand directly over the needle, and point to the northward; but these can never be very exact, because of the variations of the needle itself. See Dialing.