The octant has an ebony frame and limb with a brass index arm, fittings, and a stop for the index arm. It also has inlaid plates on the crossbar and on the back of the frame, which are both missing. There is no tangent screw, and the clamping screw is on the back of the index arm. The socket shades are missing. The index-glass, with the glass missing, is adjusted by a screw which is also missing. The horizon glass, which also has its glass missing, and the back horizon glass is adjusted by levers, wing nuts, and milled clamping screws, one of which is missing. The sight vane has two pinholes and a swivelling shutter and the back sight vane is broken. A pencil or screwdriver is missing from the crossbar. The octant has no box.

The instrument has an inlaid ivory scale from -5° to 95° by 20 arcminutes , measuring to 90.5°. The octant has an ivory vernier measuring to 1 arcminute, with zero at the centre.