A 19th-Century brass theodolite, signed Troughton & Simms LONDON, the telescope with rack and pinion focusing, dust cap, cross wire adjustors and bubble level, the vertical half-circle with silvered scale and vernier, external rack gear adjustment, the axis on twin Vee-supports, raised on the horizontal plate with level and cross-bubble, the compass with silvered dial, edge-bar needle and jewelled cap, the chamfered silvered horizontal circle with twin verniers on 4 screw tripod mounting, in mahogany carrying case - 11ins. (28cm.) wide.