The octant has a mahogany frame and index arm, boxwood limb, brass fittings and a brass stop for the index arm. There is no tangent screw and the clamping screw, which is broken and possibly an old replacement, is on the back of the index arm. The octant has two socket shades,in red and green. Index-glass adjustment is made by a screw and on both horizon glasses by levers, wing nuts and milled clamping screws. The sight vane has two pinholes and a swivelling shutter; the back sight vane has one pinhole. A small oval label on the back of the frame near the pivot has a handwritten inscription ‘H. Hughes & Son’ [illegible] ‘1908’ [illegible]. The octant has no box.

The boxwood limb displays a transversal scale from 0° to 90° by 20 arcminutes, which is vice versa for the zenith distance, measuring to 90°. The scale reads to 2 arcminutes by the fiducial edge at the end of the index arm.