Liquid compass
Bowl: Brass, black painted, filler plug at side, two electric lamp fittings at side and expansion chamber at base. Set in gimbals. Inside of bowl painted white. Short black wire lubber line fitted under verge glass. Rotatable verge ring fitted with special locking device, which is released by pressing on verge ring. Verge ring graduated to eight points and 360 degrees and carries four parallel wires for grid steering. Foreside of bowl fitted with a reflector above lubber point so that it could be seen more easily at night.
Card: Wire spider of eight elements, with two additional elements set parallel, one on each side of the N-S wire. Domed float at centre of spider accommodating pivot pin.
Needle: Six needle magnets carried below spider. N point indicated by red triangle.
Pivot: Unsighted, stem screwed to base of bowl, presumably cap at top of stem engages pin on underside of float.
On ACO wooden stand 8" x 8" (20cm x 20cm) O.A height 4.25" (10.8cm)