A fine lacquered brass aneroid pocket barometer altimeter compass and thermometer compendium retailed by Maurice Aronsberg & Co c1885
Pocket barometer having 1¾” silvered and die struck stepped dial, the outer bezel adjusted altimetric scale calibrated in feet with a range from 0 – 8,000ft divided down to 100ft, inner barometric scale calibrated in inches of mercury with a range from 23” – 31” and divided down to 1/20th”. The inset with standard meteorological terms, signed by the retailer “M. Aronsberg & Co” with address “39 Castle St, Liverpool” and marked “Compensated,” the lower part with curved thermometer, the register scaled in degrees Fahrenheit with a range from 30° -120°, divided down to 2°. Fine blued steel pointer, bevelled glass. The first quality ‘bat wing’ bridge movement, unsigned but probably by Negretti & Zambra, driven from a single 1” capsule and tensioned on a coil spring, the underside bearing no. “66.”
The drum form case with ribbed embellishment, engine turned finisher. Suspension post and bow. The verso with calibration port and attached, push-fit Singers pattern compass, hand-painted dry floating mother of pearl card having cardinal and intercardinals points, lyre indicating North, side mounted compass lock.
Presented in its correct two tier, two tone brown leather over timber, green silk and velvet lined case, snap closures on button releases.
Condition: The subject of a full service, conservation, and calibration under laboratory conditions. The barometer movement with very acceptable levels of accuracy across the standard barometric range 27 – 31” Hg, some noted deviation at lower pressures consistent with many instruments of this age and design, see performance chart from dynamic test.
The instrument overall fine. The dial crisp and bright, the lacquered brass case with a minimum of wear consistent with very little handling. The thermometer with unbroken thread and working, reading approximately 1° high at 70°F. The compass swinging freely and easily finding north, the transit lock working perfectly.
The leather travel case structurally sound, some wear, minor marks and indentations externally, some loss to colour. The fabric interior sound but with some losses to coloured silk. Snap catches working properly and closing securely, losses to leather over buttons.
Comments: These instruments infrequently occur in any event, and now very hard to find in this fine condition. As an example for a collector, this would be amongst the very best pieces of any portfolio.
Dimensions: 2¼" wide x 2⅝" long x 1½" deep
Stock No: CP2371