Barometers Realm

This is an elegant wall-mounted Counterweight barometer, circa 1870, assembled by the 19th-century Danish scientific instrument maker Julius Nissen, housed in a richly carved walnut case executed in a boldly plastic, expressive manner. The case is conceived as a free, almost sculptural composition of deeply cut leaves and scrolling forms, creating the impression of a living, organically growing ornament. The warm, dark tone of the walnut heightens the play of light and shadow within the carving and lends the object a noble, intimate presence.

At the top of the case sits a thermometer framed by a carved surround that reads like an interlacing of slender wooden twigs and leaves, seamlessly continuing the overall vegetal motif of the housing. This frame does not feel like an added component; rather, it seems to grow out of the mass of the wood itself, visually binding the thermometer to the rest of the composition.

The mercury thermometer itself is relatively large and mounted on an opaline glass plate, which gently diffuses light and provides excellent legibility for the scales. The temperature scale is dual: Réaumur on the left and Fahrenheit on the right, a feature typical of instruments intended for a broad European audience.

The lower, central portion of the case is occupied by the barometer. Its open cardboard dial is arranged in a classic concentric layout and calibrated in centimetres of mercury across a range from 69 to 79 cm. The outer ring of the scale is supplemented with Dutch weather terms, giving the instrument a distinct local cultural anchoring while also emphasising its practical, everyday function.

The dial is protected by a substantial mineral glass with a bevelled edge, neatly seated within a warm, golden-toned brass bezel. This glass does more than protect: it enhances the dial’s optical depth, creating the effect of a “window” into the instrument’s measured world. At the centre of the glass is a classic brass trend-index pointer fitted with a small knurled knob, allowing the user to mark pressure values manually.

At the heart of this barometer’s rare mechanism is a movement by the Hamburg mechanic R. Deutschbein. Its core element is a large-diameter corrugated aneroid capsule mounted on a cast-iron base, functioning as a self-elastic component: it responds to changes in atmospheric pressure without any external stretching coil spring acting on the capsule walls and without any internal spring.

Above the self-elastic aneroid capsule runs a horizontal brass beam carrying a shaft that rotates in bearings; on this shaft sits the main lever, held by a contact pin resting freely above it. The lever is fitted with an oddly shaped counterweight that ensures force closure in both directions, including when the instrument is hanging vertically. The counterweight is positioned behind the pivot point of the supporting axis, so that even in the vertical orientation it pulls the lever toward the contact pin. In this way, deformation of the aneroid capsule acts on one side of the lever, while the counterweight acts on the other.

Motion is transmitted via a vertical push-rod from the aneroid capsule to the contact pin, then onward through a system of levers and, through a fusee chain, to the central pointer arbor.

The main lever is not rigidly fixed beneath the contact pin—without additional force, contact would be lost during a fall in pressure, when the capsule tends to rise. This is precisely where the counterweight becomes essential. It takes the form of a massive cylindrical, or slightly barrel-shaped, brass weight mounted behind the lever’s pivot point, i.e., aft of the axis. Visually it resembles a brass “mushroom” or a cylinder with rounded ends.

For regulation of the barometer, the supporting axis can be adjusted in height relative to the aneroid capsule by means of a screw that emerges at the rear of the instrument’s case.

Taken as a whole, this counterweight barometer is a harmonious union of a utilitarian scientific instrument and a decorative interior object, where measurement accuracy is paired with expressive carving and a carefully considered visual hierarchy of elements. It stands as a vivid example of how 19th-century meteorological instruments became integral to the artistic culture of their time.