A very unusual French aneroid pocket barometer triptych comprising pocket barometer altimeter, thermometer, and inset compass c1900

Compendium having silvered and die struck barometer dial, the outer part having weather prognostications in French, and marked “Barométre Aneroide,” the barometric scale calibrated in centimetres of Hg with a range from 58cm – 80cm, divided to 20ths, the inner displaying altitude in metres with a range from 0m – 2400m. Blued steel pointer. Cantilevered movement driven from a single, soldered nickel alloy 1⅛” internally sprung capsule.

Concentrically set thermometer, the register calibrated in degrees Centigrade with a range from 0° – 50°, divided to 1°. Inset miniature compass on jewelled suspension, part blued pointer, the card with central rose, French cardinal and intercardinal points, held within a nickel plated bezel.

The whole contained within a drum form nickel plated case, low dome bevelled glass, compensation port to verso. Pendant and bow.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The barometer with easily acceptable accuracy, predictably and in common with most contemporaneous instruments, resolution of lower pressures (well below standard pressure) is poor. The thermometer working well with unbroken thread and apparently accurate to around ½°, tested at 23°. The compass swinging freely, and finding north easily.

Barometer dial with minor marks to centre, otherwise clean and crisp. The thermometer register clean and clear, retaining most original lacquer. The nickel plated case retaining most original finish, signs of age, oxidation and minor losses.

Comments: These late C19th French instruments are quite scarce, unsigned but almost certainly the work of Maxant. This instrument, displaying all instruments beneath a common glass, is very unusual indeed and the first such seen – compendia like these are usually double-sided, with the barometer to one side, and the compass and thermometer to the other.

In much above average condition, and a marvel to hold in the hand, this is undoubtedly a collector’s piece.