A fine possibly unique silver plated aneroid chart table barometer designed and commissioned by Captain I. Napier R.N. from Patrick Adie, 395 Strand, London c1864

Aneroid barometer having 5½” silvered and engraved stepped dial, the engine divided barometric scale showing a range from 25” – 31” inches, divided down to 100th”, the inset with semi circular thermometer, the register calibrated in degrees Fahrenheit with a range from 0° – 120° divided to 1°. Blued steel dagger form pointer, deep reflector ring, all set beneath a bevelled glass.

The Vidie pattern movement driven from a single 3” diameter soldered capsule tensioned on a C spring, the arbor running in ruby bearings. All contained within a silver plated drum form case, the verso with pull out suspension or hanging plate, calibration port, and inscribed “Designed by Captain. I. Napier, R.N., 1864. Adie, 395 Strand, London. Jewelled and Compensated.”

The whole presented in its bespoke grape velvet lined mahogany transport case, the lid with sliding semi circular inspection port, the outer lid with inset cartouche marked “Capt. I. Napier, R.N.” Lock and key, oxidised brass transport/security strap guides.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working exceptionally well with very smooth stepless response to pressure change and showing a maximum error across the range of 0.1”.

Fine overall, the dial very crisp, the brass case retaining virtually all its original silver plate. The transport case structurally sound and with excellent colour and figure, the internal fabric retaining good colour and vibrancy. The lock and sliding inspection port working correctly.

Comments: At the time of writing this instrument is 162 years old. Less than 20 years before its manufacture Lucien Vidie patented the Aneroid Barometer, and this movement by Negretti & Zambra would be one of the first designed with a C spring for balancing the capsule, replacing the original design which incorporated a coil spring. The very unusual aspect of this particular movement is the jewelled bearings supporting the arbor, possibly a first for this time.

Patrick Adie and Negretti & Zambra had strong links in the mid-19th century, particularly around the manufacture and supply of Kew Pattern and marine barometers. Adie, known for his first class instruments, many of which had nautical applications, would have been the natural choice for a senior Naval Officer looking for a scientific instrument maker to bring his design to life. Adie would have acquired the movement from Negretti & Zambra, incorporated the jewelled bearings for the arbor, and created the barometer housing, dial and transport case. The result is a very fine instrument developed for refined sensitivity and accuracy, with a substantial deck case that provided protection whilst allowing the barometer to be read.