The octant has an ebony frame with a brass index arm and fittings. It has inlaid ivory plates on the crossbar and the back of the frame. The tangent screw and clamping screw are positioned on the back of the index arm. The octant has three index shades, two red and one green. Index-glass adjustment is made by a screw and on the horizon glass by a square-headed screw and a detached key. The sight vane has two pinholes and a swivelling red shade. The adjusting key is missing. An ivory-capped pencil is fitted in the crossbar. The octant has no box.

The instrument has an inlaid ivory scale from -4° to 103° by 20 arcminutes, measuring to 91°. The octant has an ivory vernier measuring to 1 arcminute, with zero at the right.