Card for a liquid compass.
A card for early projector compass in submarines.

Card: The card is made of mica attached to the float by a wire complex. There are two bands of graduations. The outer band is white with black markings graduated to quarter points and quadrantally in degrees. The inner band is clear with black markings graduated to every other point and quadrantally in degrees, the graduation being 180 deg. out of phase to the outer band.

Needle: There are four needles set in tubes and attached to the float. The inner pair are larger than the outer pair, both in diameter and length.
Dims. Inner 3.75" (9.6 cm) Outer 3.50" (9.2 cm)

Pivot: The pivot is incorporated into the domed float, though in this example it has been unscrewed and lost.

O.A. height 2.25" (5.7 cm)