A unique brass first pattern pocket barometer, to the Fane family, manufactured by Negretti & Zambra, retailed by CW Dixey, c1860

Pocket barometer having 2½” silvered dial having a barometric range from 28–31 inches of mercury, the upper portion annotated “Stormy,” “Much Rain,” “Rain,” “Change,” “Set Fair” and “Very Dry” and signed by the retailer “C.W. Dixey.” The lower portion marked “5 New Bond St, London,” semi-circular mercurial barometer with Fahrenheit scale having a range from 40°–110°. Blued-steel pointer and gilt brass telltale with setting wheel, bevelled glass with deep dish to centre. High quality early conventional movement driven by a 2” capsule tensioned on a C spring.

All set in a heavy drum case, the verso with compensation port set at 3 o’clock, and detailed inscription: “Frances Adria Spencer Fane from her Father in Law Colonel Henry Fane, Novr 28th 1885, given to her Grandson, Vere William Garton Fane RN, on his passing into the Navy, April 4th 1905,”

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test.Working well with good sensitivity and transition, the movement required a small repair to the fusee chain which has been effected to the highest standard.

These instruments, it would appear, were not lacquered originally and thus the case remains in its bare state. The silvering to the dial remains original, though this has been carefully and painstakingly cleaned and a thin coat of preserving lacquer applied.

Comments: This is a fascinating instrument on all levels. Although signed C.W. Dixey, manufacture of this instrument is by the premier London maker Negretti & Zambra, as commissioned by Admiral Fitzroy, and of considerable quality. It conforms to the pattern of the earliest known pocket barometers originating in 1860 and only effectively produced in this size for a year or so, thus of considerable rarity (see Negretti & Zambra, A Treatise on Metrological Instruments, Chapter V: Secondary Instruments, item 49 and accompanying Fig. 34). Aspects of this instrument would indicate a prototype or early production, namely the extensive thread and dial platform, not only expensive to produce but desirous at the assembly stage facilitating adjustment of the dial datum relative to the movement. Also noteworthy is the means by which the primary lever is driven from the capsule, connected to the C spring via a transverse steel rod. 

Notwithstanding the important aspects of this instrument from a historical perspective in the evolution of the aneroid barometer, it is also very interesting for the elaborate and extensive inscription on the verso.

This unique instrument is testament to the excellence in manufacture and innovation of the maker. It is a very significant and most important piece.

Provenance: This pocket barometer was originally owned by Colonel Henry Fane, eldest son of General Sir Henry Fane GCB, and was passed to his daughter in law Frances Fane upon his death in November 1885. Frances passed the pocket barometer on to her grandson, Vere William Garton Fane, when he became a cadet in the Royal Navy in 1905. Sadly the young cadet died the following year.