The sextant has a polished brass straight-bar pattern pillar frame, with twenty pillars, and a wooden handle. The tangent screw and clamping screw are located on the back of the index arm. The sextant has four shades, two red, one orange, and one green, and three horizon shades, in red, orange, and green. Index-glass adjustment is made by a screw and on the horizon-glass, which has oval glass in a square mount, by a square-headed screw and a detached key.

Attached to the sextant is a magnifier on a 70mm swivelling arm. There is also a threaded telescope bracket in two parts, fitted for correcting collimation error. It has perpendicular adjustment made by a rising-piece and a milled knob. The telescope is 74 mm in length with an erect image. A second telescope is 182 mm with an inverted image and two parallel cross wires. It has an extra drawtube which is 90 mm in length with an erect image and four cross wires. The sight-tube is 126 mm and has two orange shaded eyepieces and a milled adjusting key. The sextant is contained in a polished mahogany keystone box, with a trade label in the lid for W.C. Cox, 93 Fore Street, Devonport and 35 South Side Street, Plymouth, and a repair label for Troughton and Simms, 138 Fleet Street, London, dated September 1915.

The instrument has a polished brass limb with inlaid platinum scale from -5° to 150° by 10 arcminutes, measuring to 125°. The sextant has a platinum vernier measuring to 10 arcseconds, with zero at the right.

Edward Troughton patented the pillar and plate frame (no. 1644 of 1788).