Boat's liquid compass. Patt 178

Bowl: A brass bowl with heavy copper encased ring at base. Bowl glazed top and bottom. Has filler plug and two expansion chambers on side. Inside is white with black horizontal lubber spike.

Card: Reduced diameter mica. Card is white with black markings graduated to points and quadrantally in degrees (one set normal, one inverted). Diameter 3" (7.6 cm)

Azimuth circle: A plain circle that carries a prismatic sight and a weight containing a spirit level

Needle: Two needles are held in tubes attached to the underside of the card.

Pivot: Unsighted.

Binnacle: A binnacle of white metal and wood. It has a removable hood which has a hinged window, containing sliding doors in the flap and a handle. The binnacle has two hinged arms for holding correcting spheres, both spheres are missing, and one bolt hole at its base. It has a candle lamp on the back side where the light is reflected through the compass by means of a brass reflector. There is also a gimbal stop on the side which prevents the compass moving when applied.
Diameter 7" (17.8 cm)

O.A. height 18" (45.7 cm)