Antique barograph having finely executed lacquered brass mechanism, raised on four turned pillars over a half-plate bevelled chassis, comprising eight pressure sensing capsule stack with calibration knob over, finely finished pivots, polished recording arm, arrestor bar, ink station with contemporaneous bottle and dipper. Silvered and engraved brass open faced dial with conventional annotation calibrated from 28 to 31 inches of mercury. Bottom part marked with “Rd no. 428606” and the maker’s name “Negretti & Zambra, London.” Blued steel hairspring and pointer.
The recording drum, serially numbered “455,” with sprung paper clip, spring loaded ‘half turn’ retaining nut. The movement contained within a separate drum form case, the top plate with winding square, stop and start lever, serial number “455 “and Negretti & Zambra “N&Z” logogram, and detailed as 7 day duration. Conical friction drive.
Five bevelled glass case with oak frame having freize drawer under, the whole raised upon slab feet.
Produced at a time when Negretti & Zambra were arguably at the height of their game, this is unquestionably of quality, with a full range of adjustments available, some of which were not available on less well-made or second quality instruments. The fit and finish of the component parts is very good indeed.
Hitherto Negretti & Zambra had imported and sold barographs made by Richard Frères, France but badged as “Negretti & Zambra.” They also bought and re-sold instruments manufactured by Short & Mason. Here, the barograph movement is a Negretti & Zambra one but the dial and probably the movement are Short & Mason, licenced to Negretti & Zambra.
The subject of a complete re-build, conservation and calibration, with attention having been paid to alignment, balance and pivots. The clockwork mechanism fully overhauled. The bespoke arm manufactured and replaced by us, the brass work remains original in all respects. The case disassembled, cleaned, re-lacquered, and reassembled. Small shell chip to inside top right end glass. Tested under laboratory conditions and now exhibiting very good sensitivity and progression – see performance chart.
This is now an absolutely first class antique barograph in excellent condition.
Dimensions: 14½” wide x 8½” high x 9” deep
Stock No: BG1469