Mariners barometer having 4¼” silvered and finely engraved twin concentric scale engine divided dial, the barometric outer calibrated in inches of mercury with a range from 23 – 31” Hg,  principal stations on the inch but divided to 1/100ths, the inner altimetric calibrated in feet with 0 set at 30” Hg (standard pressure) and with a range from -1,000ft – 7,000ft, principal stations on the 1,000’ and divided to 10’. The upper part marked with the retailer “M. Pillischer,” the lower “88 New Bond Street, London.”

Fine blued steel pointer, gilt brass index, bevelled glass, rolled brass bezel. First quality single 3” nickel alloy capsule driven movement tensioned on a C spring contained within a drum form case, the verso with adjustment port and lower set screw. Extension post and suspension ring.

Presented within its original mahogany bevelled transport or deck case having brass hinges struck “W.T & S Improved” and secured on steel screws, original functioning single lever lock with key, glazed viewing port, top suspension ring on a swivel mounted to flat brass disc secured on three blued steel screws. The interior and exterior finished in high gloss shellac.

Condition: The subject of a full mechanical overhaul, conservation, and calibration under laboratory conditions, see performance chart. The dial clean and crisp, very slight oxidation to periphery, very faint radial marks only visible in critical lighting, the glass clean and chip free. The movement working exceptionally well showing a maximum error of equal equal to or less than 0.06” across the normal barometric scale, good sensitivity and stepless progression.

The lacquered drum case retaining a very good proportion of original finish, some losses, oxidation and wear consistent with placement in its transport case. The case has contracted slightly across the grain and so the fit of the instrument into the case is snug but easily removed with care. The mahogany case in very good condition, showing no signs of warping or cracking, and retaining a very high proportion of the original shellac finish. Minor marks scratches and light impressions entirely commensurate with age.

Comments: Though not rare, these instruments are infrequently seen and, in this condition, extremely difficult to find. It is interesting to note the altimetric scale zeroed at standard pressure, an unusual feature for aneroid instruments with altimetric scales, this would strongly suggest primarily a nautical application. This particular piece would have been offered to explorers and mariners alike. 

Instruments of this design when released became an obvious choice for yachtsmen, being a far more practical proposition than the established Kew pattern mercurial barometer with their known disadvantages of slow response to rapidly changing pressure and, of course, ever present vulnerability to damage and requirement for bulkhead space.

Moritz Pillischer, who traded from 88 New Bond Street between 1854-1888, is known to have retailed the finest instruments available at the time, though not known particularly as a maker of aneroid instruments. It is almost certain that this piece was manufactured by Negretti & Zambra who in that period were making some of the finest instruments available anywhere in the world. The finely divided dial and obvious quality of the movement all point to an instrument of exception.

“W.T & S” is most probably William Tonks & Sons of Birmingham, brassfounders.

Dimensions: 6½” wide x 6½” deep x 2⅝” high

Stock No: BA1862

Price: SOLD