Barometers Realm

Before us is one of the earliest serial aneroid barometers—an example bearing serial number 1342, manufactured around 1850 by Lucien Vidie for the English market. It belongs to the formative period of the aneroid, when form, material, and visual language were still being explored and articulated in parallel with the very physics of the new measuring principle.

The barometer’s case is executed in a tympanum-like form, made of turned brass produced by pressing and drawing on mechanical or hydraulic presses. This method gives the case a sense of wholeness and precise geometry, as well as the thin walls characteristic of early aneroids while retaining sufficient rigidity. The overall silhouette deliberately alludes to the format of wall and pocket watches: a circular body, a central dial, and an upper suspension ring. This choice was far from accidental. Vidie consciously selected a form familiar to the prospective user — a clock-derived dial format that rendered the new, still unfamiliar instrument psychologically intelligible, immediately legible as a precise measuring device rather than an experimental curiosity. The brass suspension ring mounted at the top of the case reinforces this association and at the same time provides a practical means for wall mounting.

Particular attention is drawn to the thin brass bezel framing the glass. Its surface is decorated with a fine knurled ornament—uniform, rhythmic, and executed with great precision. This ornament visually “loosens” the boundary between case and glass, softening the transition while lending the bezel a tactile expressiveness. Such treatment demonstrates that Vidie conceived the aneroid from the outset not as a crudely utilitarian instrument, but as an object deserving careful finishing and visual credibility.

The dial is made of dense card and reinforced along its edge on the reverse side with a thin zinc strip, serving to stabilise its shape and protect it from deformation. The dial is set into a brass reflective ring, which enhances visual depth and emphasises the central area of the scale. Its surface is light and even, with crisp printing and carefully balanced typography.

The barometric scale has a concentric layout and is calibrated in London inches of mercury, ranging from 23 to 31, divided into fortieths—a fine graduation that attests to the instrument’s serious aspirations toward accuracy. Along the outer edge, the scale is supplemented with standard textual weather terms in English. These inscriptions are rendered in a serif typeface, combining lowercase and uppercase letters, which makes the text not only informative but also visually balanced. Distributed along the arc of the scale and logically correlated with pressure changes, these terms form an early interpretive “map” of weather—traditional in origin, yet of limited informational value.

The dial is protected by a thin mineral glass. At its centre is a knurled brass knob used to control an auxiliary pointer—the barometric trend indicator. This feature underscores the analytical nature of the instrument: the user could fix a previous pressure reading and clearly observe its change over time. The main indicating hand is made of steel and finished by heat bluing, giving it a deep dark-blue hue. A characteristic crescent motif is placed on the tail of the hand.

At the heart of the mechanism lies a sensitive aneroid capsule made of copper, invented by Lucien Vidie himself. He proposed measuring atmospheric pressure through the degree of compression experienced by elastic bodies under the stress of the surrounding air. Vidie asserted that a vacuum could be created within a thin-walled metal vessel with a corrugated surface, that this vacuum would be preserved indefinitely, and that the elasticity of such a barometric vessel—with its non-uniform resistances—could be exploited to measure variable atmospheric pressures. It is precisely this non-uniformity of resistance that constitutes the essence of Vidie’s patent. Among the many possible forms, he preferred the cylindrical one, as it provided a stronger action. Atmospheric pressure causes the Vidie chamber to flex, drawing its two opposing walls closer together. To enable this effect, the upper and lower membranes of the capsule must first be forced apart after the vacuum is created, which is achieved by means of an external coil spring held at the end of a curved cast-iron lever. Motion is transmitted to the pointer arbor via a fusee chain. This is the earliest known and easily recognisable movement produced by Vidie, distinguished by two square-headed adjustment screws on the main arbor.

The barometer is accompanied by its original protective wood case, which, however, requires restoration. Only the lower portion of the case has survived, lined with fabric and purple velvet, while the lid is missing; of it, only a single rib with its brass hinges remains.

Taken as a whole, this Lucien Vidie barometer is not merely an early aneroid, but a tangible witness to the moment when experimentation gave way to serial production. Its watch-like form, careful metal finishing, thoughtfully conceived scale, and clear typography reflect the inventor’s determination to make the new measuring device intelligible, reliable, and worthy of trust. It is a rare and historically significant object, standing at the very origins of the entire subsequent tradition of aneroid barometers.