The octant has an ebony 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. There is no tangent screw and the clamping screw is located on the back of the index arm. The octant has two socket shades in red and orange. The foot of the instrument’ frame is broken. Index-glass adjustment is made by a screw, but the mount is incomplete. Both horizon glasses are adjusted by levers, wing nuts and milled clamping screws, one of which is a replacement. The sight vane has two pinholes and a swivelling shutter, whereas the back sight vane has one pinhole. A pencil or screwdriver is missing from the crossbar. The octant is contained in a stepped oak box which has been repaired.

It has and inlaid ivory scale from -2° to 99° by 20 arcminutes, measuring to 90°. The octant has a cracked ivory vernier measuring to 1 arcminute, with zero at the right.

The instrument is unsigned, but does have a scale mark for Spencer Browning and Rust allowing the assumption to be made that they are the maker.