Liquid compass
Bowl: Brass, filler plug at base, a syphon tube expansion chamber also fitted to base. Inside of bowl painted white. A directional arrow is fitted across diameter below verge glass, at centre of arrow is fitted the top pivot of pivot system.
Card: Wire spider of four elements, the E & W wire is bent upwards at each end, the N & S wire is bent downwards at each end. The N point is indicated with a cross.
Needle: Two needle magnets fitted below spider. no float is provided, the pivot stem passes through centre of spider.
Pivot; Double pivot type. Upper pivot point engages in pivot cap fitted to centre of arrow at top of bowl. Lower pivot engages in cap carried at centre of bridge mounted across base of bowl.