The octant has a mahogany frame and limb with a brass index arm, fittings, and a brass stop for the index arm. It also has inlaid ivory plates on the crossbar and on the back of the frame, which is missing. There is no tangent screw and the clamping crew is located on the back of the index arm. The octant has three socket shades, two red and one green. Index-glass adjustment is made by a screw and on the horizon glass by a lever, wing nut, and a milled clamping screw. The sight vane has two pinholes and a swivelling shutter. An unused ivory-capped pencil is fitted in the crossbar. Decorative engravings are found on the index arm. The octant has no box.

The instrument has an inlaid ivory scale from -2° to 99° by 20 arcminutes, measuring to 91°. The octant has an ivory vernier measuring to 1 arcminute, with zero at the right.