Details
A rare 19th-Century surveyor's combined alidade rule and square,
signed on the underside Manufactured by Negretti & Zambra, London. Patentee George Francis, C.E. Chester., the lacquered-brass upper plate engraved with scales, with level and cross bubble, two sets of folding sights, the compass box with vernier and scale engraved 0°-180°, with silvered dial, the edge-bar needle with jewelled cap and clamp, one side with two folding sights and bubble level, the underside engraved with two scales, one inscribed feet perp, the other feet base -- 12¼in. (31cm.) long opened, contained in the original leather carrying case -- 8½in. (21cm.) long closed
See Colour Illustration and Detail
signed on the underside Manufactured by Negretti & Zambra, London. Patentee George Francis, C.E. Chester., the lacquered-brass upper plate engraved with scales, with level and cross bubble, two sets of folding sights, the compass box with vernier and scale engraved 0°-180°, with silvered dial, the edge-bar needle with jewelled cap and clamp, one side with two folding sights and bubble level, the underside engraved with two scales, one inscribed feet perp, the other feet base -- 12¼in. (31cm.) long opened, contained in the original leather carrying case -- 8½in. (21cm.) long closed
See Colour Illustration and Detail
Sale room notice
This Lot includes the original mahogany and brass tripod stand.