Octant made by John Bird, London, about 1772. Mahogany frame and limb with a lacquered brass index arm and fittings; the back of the limb is also brass-covered, and there is a wooden pad-shaped handle on the back of the frame. Signed on the scale: J. Bird London. Surface-mounted lacquered brass scale from 80° (-10°) to 100° every 20', measuring to 93°. Lacquered brass vernier to 1', zero at the centre. The tangent screw and clamping screw are fitted to the limb on a separate shoe, to the right of the index arm. Two socket shades (both red); two back sight socket shades (both red). Index-glass adjustment by screw; adjustment of the horizon glasses by levers, wing nuts and milled clamping screws. The sight vane is missing (broken) perpendicular adjustment by rising-piece and a milled knob; the back sight vane is missing. No box.