Bowl-Brass, two card fins on inside of base, pivoted on roller bearings in octagonal gimbal. Outer gimbal journal resting on elliptical brass springs which have tension screws. Provision for four studs projecting into bowl, two missing. Black painted lubber line.
Card-black card with white markings graduated to points with decorated North and East points. Marked quadrantally in degrees. Underside of card has four paper fins.
Needle-Flat bar type perforated for the insertion of balancing weights. Similarly perforated cross balance of brass. Jewelled pivot cap attached. Length 5.75" (14.5cm)
Pivot-Brass pivot pin mounted in brass held by screw through base of bowl.