Liquid compass
Bowl: Grey painted brass, filler plug at side, expansion chamber at base, contained in outer protective casing having anti-vibration damping. Diameter 4.8" (12.3cm) Inside of bowl painted white, fitted with short wire lubber pointer under verge glass. Rotatable verge ring, graduated to 360 degrees, carrying four parallel wires for grid steering and fitted with two verge ring locks.
Card: Wire spider of eight elements, N & S red, rest black, N point indicated by a red diamond. Centre of spider has a cage accommodating the pivot cap, no float is fitted.
Needle: Two needle magnets mounted below the spider.
Pivot: Unsighted believed to be of the inverted type. With pivot point at top of brass stem engaging in underside of pivot cap at centre of spider. Brass pivot stem mounted on bridge attached across base of bowl. O.A. height 3.0" (7.6cm)