A very good and unusual pattern motor or panel mounted aneroid barometer by Negretti & Zambra no 16291 c1920

Auto aneroid having 2¾” white illuminated dial on a black painted ground, barometric scale calibrated in inches of mercury with a range from 26” – 31” divided down to 1/20”, the upper part marked “Compensated for Temperature“ and “Aneroid,” the lower signed by the maker “Negretti & Zambra, London,“  with serial no. “16291.” Black and white painted light alloy pointer. Heavy rotating bezel with engine turned circumference, coupled white arrow index, deep bevelled glass.

Conventional movement driven from a single flux welded 2” capsule tensioned on a C spring. All contained within a low drum form case, forward mounting flange with three fixing points, calibration port to verso.
 
Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working exceptionally well across the scale.

The glass with minor chips to bevel, some scratches overall. The dial very crisp and clearly marked. The brass case with original black painted finish to rear, losses to front flange and bezel.
 
Comments: We have seen many of these instruments – this one is quite different for its very heavy construction, deeper bevelled glass and, what was at the time, a state of the art new generation pressure sensing capsule.

This is a very unusual variation, the heavy engine turned bezel easily operated with a gloved hand and clearly designed for that scenario. Most likely this was a standard fitment to a prestige car of the time.

Very much a collector’s piece.