A 19th-Century brass theodolite, signed Troughton & Simms LONDON, the telescope with rack and pinion focusing, ray shade, bubble level and cross wire adjustors, located on the limb by twin clamps, the vertical half-circle engraved 50°-0-30° Diff. of Hypo & Base on one side, the other side 0°-90° (X 2), with silvered scale vernier and magnifier, the axis on twin Vee-supports, mounted on the compass box with silvered dial, edge-bar needle and clamp, the horizontal plate with level and cross-bubble and twin verniers over the silvered chamfered horizontal circle and socket for magnifier, with tangent screw fine adjustment and clamp, on 4 screw tripod mounting, overall height 11½ins. (29.2cm.).

细节

A 19th-Century brass theodolite, signed Troughton & Simms LONDON, the telescope with rack and pinion focusing, ray shade, bubble level and cross wire adjustors, located on the limb by twin clamps, the vertical half-circle engraved 50°-0-30° Diff. of Hypo & Base on one side, the other side 0°-90° (X 2), with silvered scale vernier and magnifier, the axis on twin Vee-supports, mounted on the compass box with silvered dial, edge-bar needle and clamp, the horizontal plate with level and cross-bubble and twin verniers over the silvered chamfered horizontal circle and socket for magnifier, with tangent screw fine adjustment and clamp, on 4 screw tripod mounting, overall height 11½ins. (29.2cm.).
See illustration