A scarce colliery wall or bulkhead aneroid barometer by Short & Mason for John Davis & Son (Derby) Ltd, ex-Manvers Main Colliery c1930
Aneroid mining barometer having 7½” silvered and engraved dial, the barometric scale calibrated in inches of mercury with a range from 27” – 33” and divided down to 1/20th, the upper part marked “Mining Aneroid“ and “Compensated for Temperature,” the lower part with semi circular thermometer, the register calibrated in degrees Fahrenheit with a range from 20° – 140° divided to 2°, signed by the retailer, “John Davis & Son (Derby) Ltd, Derby.” Blued steel pointer, gilt brass index, the arrow marked in red paint, bevelled glass.
Standard Vidie pattern movement driven from a single 2¾” flux welded capsule tensioned on a C spring, generally with applied grey anticorrosion paint, the chassis struck with Short & Mason “S&M” logogram. All contained within a low drum form case, inner spring cushioned movement shroud. Bulkhead or wall fixing points at 12, 4 and 8 o’clock.
Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement responding well to pressure variation across the scale.
The dial with some discolouration, most probably due to contact with hydrogen sulphide, a common gas found in mines, the dial otherwise in good condition, the thermometer with intact thread and working reading about 1° high, quite within expectation. The outer case retaining a good proportion of its original japanned finish.
Comments: This is a very original instrument, now very hard to find and particularly interesting with provenance to Manvers Main Colliery in the West Riding of Yorkshire, which finally closed in 1988.
It would appear that Negretti & Zambra made these “Mining Aneroid” instruments as well with near identical external appearance – this is entirely feasible since the Coal Board may well have commissioned two suppliers with a common specification.
Dimensions: 9½" diameter x 2⅜" deep
Stock No: BA2602
Price: Vavasseur Archive - not currently for sale