The octant has a pear-wood frame, limb and index arm; brass fittings and a brass stop for the index arm, with an inlaid ivory plate on the crossbar, and two red socket shades. Index-glass adjustments can be made by a screw and on both horizon glasses by levers, wing nuts and milled clamping screws. There is no tangent screw and the clamping screw is on the back of the index arm. The sight vane has two pinholes and a swivelling shutter and the back sight vane has one pinhole. The octant has no box..

The instrument has an inlaid boxwood 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.