Intended for use in a projected transatlantic flight in the first large Curtis flying boat (abandoned due to the war). This type of compass was subsequently used in airships during the war. Aluminium was used in its contruction to reduce weight.

Bowl: Black painted brass, filler plug at side expansion chamber and glass aperture for illumination of lubber line are fitted in base. Inside of bowl is painted white. Black painted lubber line carried on a white painted plate projects from fore side of bowl. Verge ring is fitted with two small spirit levels, placed 90 degs apart. At centre of verge glass is a shadow pin mounting (two pins are located in carrier in edge of binnacle). Mounted in aluminium dwarf binnacle. Diameter 9.25" by three U-shaped sockets lined with rubber into which three trunnions on the bowl engage. The space between bowl and binnacle is filled with horse-hair to damp out vibrations. Binnacle hood has four celluloid windows around side and the top carries a lens and adjustable mirror, to give a magnified image of card and lubber line, and an electric lamp is fitted.
Card: Mica (?) White with black markings, graduated to 1/2 points and 360 degs. At centre of card is a black painted float dome. Diameter 5.5" (14cm)
Pivot: Unsighted, possibly inverted type and attached to bridge mounted across base of bowl.
Needle: Unsighted
O.A. Height 14" (37cm)