Barometers Realm

The barometer is housed in a 12-centimeter solid brass case with a warm golden hue. The top section features a sturdy hanging ring. One of the most remarkable details is the bezel, adorned with an intricate pattern resembling interwoven threads or a scale-like motif. This is a highly interesting decorative element, characteristic of early aneroid bezels found in cylindrical brass cases. The ornamentation was likely created through engraving or embossing, adding an extra layer of visual depth to the instrument.

The face of the barometer is a minimalist silvered-brass dial. At the top, it features an engraved barometric scale in centimeters of mercury, ranging from 72 to 80 centimeters. Just outside the semi-concentric scale are engraved standard French weather condition indications.

In the lower part of the dial is a curved mercury thermometer, with a spherical reservoir embedded within the case. Along the glass capillary tube is an engraved centigrade temperature scale.

Around the perimeter of the dial is a polished brass reflector ring, onto which a flat protective glass is mounted. This glass is held in place by a thin outer bezel.

At the heart of the movement is a sensitive aneroid chamber (Vidie capsule) made of copper. The capsule’s walls expand and contract in response to changes in atmospheric pressure. To transmit and amplify this subtle movement, a large iron plate is attached to the top of the capsule, its edges resting on supports. A main lever extends from the right side of this plate, functioning as a continuation of the plate itself, and presses against a strong helical spring.

At the base of the mechanism, the main lever is connected by a hinge joint to a secondary short lever, which further amplifies the movement. This short lever drives a vertical lever, whose end is linked by a chain (resembling a bicycle chain) to the indicator shaft, which rotates the pointer. Around the shaft, a fine hairspring provides light tension, eliminating pointer backlash.

The barometer’s movement is in excellent condition; traces of lubrication are visible, indicating that the instrument was maintained and oiled over time. As a result, the barometer is fully functional.