Diamond-frame pattern sounding quintant.

Sounding quintant made by Edward Troughton and William Simms, London, about 1890. Anodized diamond-pattern frame, polished limb, wooden handle. Signed on the limb: Troughton & Simms London. Marked at the bottom of the index arm: H.O. [broad anchor] 76. Inlaid silver scale from -5° to 180° every 30', measuring to 151°. Silver vernier to 1'. The tangent screw working against a spring-loaded stop, and the clamping screw are on the back of the index arm. No shades. Index-glass adjustment by screw; adjustment of the horizon glass by capstan screws and a square-headed screw and a detached key (missing). Magnifier on a 65 mm swivelling arm, a frosted glass shade. Threaded detached telescope bracket without adjustment. Telescope (70 mm, large objective) erect image. With wooden carrying case.