Compass, Mariner's

A compa distinguished by the card being attached to and rotating with the needle. A mark, the "lubber's mark" of the sailors is made upon the case. This is placed so that the line connecting it, and the axis of rotation of the card is exactly in a plane, pa ing through the keel of the ship. Thus however the ship may be going, the point of the card under or in line with the "lubber's mark," shows how the ship is pointing. The case of the mariner's compa is often bowl-shaped and mounted in gimbals, a species of universal joint, so as to bc always horizontal. (See Compa , Spirit-Gimbals.) IMG:8956969607833025625_143F109.jpg: FIG. 109. MARINER'S COMPASS.