Liquid compass
Bowl: Brass, grey painted. Filler plug on side of bowl, expansion chamber fitted to base. A frame incorporating a short directional arrow and carrying the top pivot of the double pivot system is fitted across diameter of bowl below verge glass.
Card: Wire spider of four elements, each element is bent upwards at its end. The N point indicated with a yellow diamond.
Needle: Two needle magnets fittted below spider. No float is provided and the pivot stem passes through the centre of spider.
Pivot: Double pivot type, uper pivot point engages in pivot cap fitted to centre of the frame at top of bowl. Lower pivot engages in cap carried at centre of bridge mounted across base of bowl.