Bowl-Dia 8.25" (21cm) Grey painted brass, filler plug and expansion chamber unsighted. Domed verge glass. Ungimballed.
Card- Dia.6.9"(17.5cm) White plastic ring with black markings, graduated to 360 degs attached by a plastic framework to cruisiform float at centre. Fitted with a black insulating shield.
ACO Catalogue: The compass works on the Wheatstone bridge principle but, unlike the A.T.M.C., instead of the whole bowl, only the electrodes follow-up, the resistance between them being varied by interposing an insulating shield carried by the card. The horizontal magnets are carried in slides in a central tube as is common to this type of binnacle, but the vertical magnet is only 1" long, carried in a horizontally adjustable holder in a bridge spanning the spherical top of the compass. The quadrantal correctors are small plates carried in three holders to port and starboard and on the starboard bow.
Binnacle- Dia. 16.4" (41.5cm) Grey painted plastic with grep painted metal fitings. For correctors see ACO.Cat remarks above.
Hood-Grey painted aluminium (?) with circular glazed aperture with lid and shutter.