The octant has a black-lacquered brass plain-pattern frame with a wooden handle. The tangent screw and clamping screw are positioned on the back of the index arm. The octant has four shades, three red and one green and three horizon shades, two red and one green. Index-glass adjustment is made by a screw and on the horizon glass by capstan screws. Attached to the octant is a magnifier on an 89mm swivelling arm as well as a threaded telescope bracket without adjustment. The telescope is 82 mm in length with an erect image. The sight-tube is 82 mm, and has a red shaded eyepiece. The octant is contained in a polished wooden keytone box, with a trade label in the lid for James White, 209 Sauchiehall Street, and 16, 18 Cambridge Street, Glasgow (1884-90).

The artificial horizon consists of a spirit levels to hold the instrument vertically. One level is fitted to the upper edge of the crossbar and a second spirit level is fitted at the centre of the lower handle-securing bracket. The bubble in the second level is missing.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 120° by 15 arcminutes, measuring to 105°. The octant has a silver vernier measuring to 15 arcseconds, with zero at the right.