Pocket barometer with 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 degrees. Blued-steel pointer and gilt brass telltale with setting wheel, bevelled glass with deep dish to centre. Heavy drum case, the verso with 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,” compensation port set at 3 o’clock. High quality early conventional movement driven by a 2” capsule tensioned on a “C” spring.

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. One other similar instrument has been seen with the dial signed “Negretti & Zambra,” though that example lacked the benefit of the thermometer.

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. The subject of detailed conservation, these instruments, it would appear, were not lacquered originally and thus the case remains in its bare state. The movement required a small repair to the fusee chain which has been effected to the highest standard. The silvering to the dial remains original, though this has been carefully and painstakingly cleaned and a thin coat of preserving lacquer applied.

Working well with good sensitivity and transition, this unique instrument is testament to the excellence in manufacture and innovation of the maker. It is a very significant and most important piece.

Dimensions: 2¾” wide x 1½” deep

Stock No: PB0401

Price: SOLD