Beschreibung:

A rare 19th-Century French lacquered-brass magnetometer, signed on the horizontal circle Brunner à Paris , the telescope with rack and pinion focusing, object glass dust cap, prismatic sight with two shades and viewing apperture to side, mounted on twin circular supports to the 7¾in. (19.7cm.) diameter vertical circle, with finely divided silvered scale, twin verniers and magnifiers (scale shades missing) , with tangent-screw fine adjustment and clamp, the axis supported on two brackets and mounted with a graduated bubble level, the cross-bubble similarly graduated, raised on a frame located on the axis and a support, the black-enamelled brass main support frame with limb, supporting the magnetometer accessories, with sighting tube suspension column with fine adjustment and viewing tube, the limb mounted at the centre with two vernier magnifier bars, the magnifiers reading off the vernier scales against the 7¾in. (19.7cm.) diameter horizontal circle with similar finely engraved silvered scale, tangent-screw fine adjustment and clamp, the limb with counterbalance weight engraved on the upper face no. 2 , raised on a column and tripod stand with three adjustable screw feet, with accessories including tommy bar, turn-key, spare suspension brackets and a supplementary case containing steel and iron rods, a spool of suspension wire, the underside of the lid inscribed in ink Bureau des Longt Brunner No. 2 , the face inscribed in ink Haut , the underside of the supplementary case additionally inscribed Bureau des Longitudes (Montsouris Brunner No. 2) , the instrument mounted on an oak platform base, and contained in the original walnut carrying case with two side and upper iron carrying handles -- 19½in. (49.5cm.) high See Colour Illustrations and Detail