The sextant has a polished brass frame and a detached wooden handle. The tangent screw is positioned on the front of the index arm and the clamping screw is on the back. The sextant has three shades, one green and two red, with the hinge of middle shade broken. It also has three red horizon shades. Index-glass adjustment is made by a screw and on the horizon glass, with its glass missing, by a square-headed screw, a detached milled screw, and a fixed milled knob.

Attached to the sextant is a magnifier on a 76mm swivelling arm. There is also a detached threaded telescope bracket in two parts, which can be mounted on the back of the frame, and is fitted for correcting collimation error. It has perpendicular adjustment by a rising-piece and a milled knob. The telescope is 108 mm in length with an inverted image and four cross wires. A second telescope is 45 mm in length with an erect image and a green shaded eyepiece for use with the oil lamp. The sight-tube is 73 mm in length with a rotating shaded eyepiece; however the rotating mount with the shade is missing. Accompanying the instrument is a milled adjusting key, as well as a pendulum and two glass bottles, one of which contains oil for dampening, the other contains lamp oil). A handwritten label on the artificial horizon reads, ‘1° to add for correction of horizon’. The sextant is contained in a fitted rectangular mahogany box with a second, square box inside for the oil bottles. In the lid of the second box is a handwritten note ‘1° 49'' Add for correction of Horizon’.

The artificial horizon consists of a 95 mm long bracket for attaching the horizon to the frame. The pendulum is lowered in a black-lacquered brass conical attachment, filled with almond oil to dampen the pendulum’s movement. A separate oil lamp can be fitted to the bracket for illumination at night. Alexander Bridport Becher (1796-1876) invented his artificial horizon in 1834. This example is by an unknown maker and has been fitted on an older sextant.

The instrument has a polished brass limb with inlaid silver scale from -3° to 139° by 15 arminutes, measuring to 128°. The sextant has a silver vernier measuring to 1 arcminute, with zero at the right.