A scarce silver hunter cased compendium including aneroid pocket barometer altimeter with rare Bourdon type thermometer by Francis Barker c1896

Pocket barometer having 1½” silvered and die struck dial, outer crown operated altitude ring calibrated in feet with a range from 0 – 10,000ft divided down to 100ft and 50ft, and impressed “Rd 149175,” inner barometric scale calibrated in inches of mercury with a range from 21” – 31” divided down to 1/10”, the upper part with standard meteorological terms, further annotated “Improved Scale,” “Compensated,” and impressed “Rd 149175.” The lower part with inset analogue temperature dial calibrated in degrees Fahrenheit with a range from 30° to 130° divided to 2°. Blued steel pointers, bevelled glass.

Conventional Vidie pattern movement driven from a single 1” nickel alloy capsule and tensioned on a C spring. The thermometer mounted to dial verso and comprising Bourdon tube, fine chain, transmission cock and tensioning hair spring. All contained within a silver full hunter watch case, crown cover release, calibration port to verso, pendant and bow. Hallmarks for Francis Barker & Son and date year 1896 to inside case, inside cover and bow.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The barometer showing easily acceptable levels of accuracy over standard barometric range.

Generally much above average, the dial with some minor marks and signs of ageing, the thermometer working, the silver case with minor marks but with good shine. The hallmarks clearly struck.

Comments: Registered design number “149175” was awarded to Francis Barker on 1 May 1890 for the detailed inner scales, which enabled greater accuracy in determining heights. The thermometer is based on a patent for “An Improvement in Metallic Thermometers and Barometers” that was issued to Thomas Wheeler in 1894.

The drawing is taken from the Barker catalogue of 1907, showing a later version of this instrument.

This is a very unusual combination, attractive and rare. Certainly a collectors piece.