Liquid compass
Bowl: White metal, fitted with filler plug at side and an expansion chamber at base. The bowl is set in an anti-vibration mounting. Inside of bowl painted white. A centesimal scale graduated to 100 degrees is fitted on fore side of bowl, the centre of scale marked by a small arrowhead and corresponds with the fore and aft line.
Card: Wire spider of seven elements and has a very small card at centre showing eight points. four of the elements are marked 0, 1, 2, and 3. These are placed so that the angular distance between 0 and 1, 1 and 2, 2 and 3 is 100 degs in each instance, the distance between 3 and 0 being 60 degrees. So if course to steer is north, No 3 is made to coincide with 60 degs on scale, and the course is therefore either 360 degs or 0 degs.
Needle: Two magnets slung beneath card.
Pivot: Unsighted, appears to be a pin engaging in cup attached to underside of small card, and secured to base of bowl on a bridge.
O.A. height 3.26" (8.4cm)