A fine lacquered brass surveying theodolite, signed on the horizontal plate W.Harris & Co 50 Holborn London, the telescope with dust cover, rack-and-pinion focusing, internal crosshairs, over bubble level held in twin-arm locking cradle, mounted on vertical half-circle, divided on one side 30°-0°-30° Diff of Hypo & Base, the other with three quarters silvered scale divided 90°-0°-50°, with vernier scale, the axis with twin conical supports on twin A-frames, with tangent screw adjustment and clamp, the horizontal plate with bubble and cross bubble, the compass box with silvered scale, engraved compass rose, edge bar needle cap and clamp, twin silvered vernier scales, with tangent screw adjustment and clamp, over horizontal silvered scale divided 10°-360°, on four-screw tripod mount, with butterfly locking nut - 10¾in. (27.5cm.) high; and a mahogany carrying case

Details

A fine lacquered brass surveying theodolite, signed on the horizontal plate W.Harris & Co 50 Holborn London, the telescope with dust cover, rack-and-pinion focusing, internal crosshairs, over bubble level held in twin-arm locking cradle, mounted on vertical half-circle, divided on one side 30°-0°-30° Diff of Hypo & Base, the other with three quarters silvered scale divided 90°-0°-50°, with vernier scale, the axis with twin conical supports on twin A-frames, with tangent screw adjustment and clamp, the horizontal plate with bubble and cross bubble, the compass box with silvered scale, engraved compass rose, edge bar needle cap and clamp, twin silvered vernier scales, with tangent screw adjustment and clamp, over horizontal silvered scale divided 10°-360°, on four-screw tripod mount, with butterfly locking nut - 10¾in. (27.5cm.) high; and a mahogany carrying case

Lot Essay

William Harris & Co flourished as instrument makers from 1799-1848. They were making instruments at 50 High Holborn from 1813-48.

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