Double sounding quintant.

Double sounding quintant made by Edward Troughton and William Simms, London, about 1840. Lacquered brass frame and limbs, with a detached wooden handle. Signed on the frame: Troughton & Simms | LONDON. Inlaid silver scales, both from -5° to 182° every 30', measuring to 146°. Silver verniers to 1', zeros at the right and the left. The tangent screws and clamping screws (one missing) are on the back of the index arms. No shades. Two index glasses, adjustment by screws; adjustment of the two horizon glasses by square-headed screws and a detached key. Two magnifiers (single lenses), each on a 35 mm swivelling arm. L-shaped threaded telescope bracket fixed to the frame, without adjustment. Telescope (115 mm) inverted image. Two shaded eyepieces (both grey/green). An adjusting key. In a fitted rectangular wooden box