WWI compass of semi-spherical form with extended cylindrical viewing port, the fully floating compass card of flared form and having reverse marked (to inside and outside) cardinal and intercardinal points on fine elevated suspension post. Magnetic bars below on cat’s cradle supports. Wire lubber lines. The viewing port with bevelled glass and screw fixed bezel. The sphere top with fluid filler.

The instrument suspended on anti-vibration mountings within an outer supporting ring. The whole raised on a light alloy base with four fixing points.

Condition: As found, clear signs of age and patination externally, probably originally bright plated with traces remaining. The anti-vibration mountings intact, the white/cream painted interior clean and in good condition, the compass swinging freely and easily finding North. The alloy base with traces of original black paint.

As shown, this instrument lacks fluid filling. A basic pressure test has shown that it may have good integrity and filling would be possible.

Comments: This is a non-marked Pattern 259 compass developed by Creagh-Osborne and Henry Hughes & Son, and used in Royal Flying Corps aircraft in World War I. This example is, however, designed for fixing onto a flat surface, generally precluding use in an airplane and entirely consistent with fitment to an early WWI tank such as the Foster Mark I tank.