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Object Overview
This Hallway barometer, made about 1930, is an unusual example of the union of the utilitarian and the decorative in objects of everyday use. It is built on a board of burr maple, on which a barometer is mounted together with two clothes brushes. Such a hallway set was intended for the entrance of a house: on the way out one could both glance at the weather and brush down a coat or dress.
The instrument is of German manufacture and was made for export, as its English-language scale shows. It is unsigned, though one may suppose the maker to have been the firm of Lufft — this cannot, however, be stated with certainty in the absence of a mark.
The clothes brushes, fixed on either side of the barometer, carry on their backs brass repoussé mounts with a flowing floral-and-acanthus design and a beaded border. Delicately integrated into the whole, they lend a functional object decorative richness and betray the attention to detail characteristic of pieces of the period.
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aneroid capsule tensioned on a C-spring
brass, enamel, glass, wood
The barometer itself is set in a brass bezel holding a thick mineral-glass crystal, with a trend-indicator hand at the centre. The open enamel dial is marked with Gothic weather legends. The barometric scale is graduated in London inches of mercury over the range 26–31 in, and the weather terms — Stormy, Rain, Change, Fair, Very Dry — are set in a Gothic (blackletter) type with red initial capitals, separated by small flourishes, giving the instrument a deliberately antiquarian character.
The dial is vitreous (porcelain) enamel on metal — a thin layer of opacified glass fused to a metal plate during firing. Its whiteness and opacity are produced by an opacifier incorporated into the enamel. The enamel also contains a small addition of uranium: imperceptible in daylight (the dial remains white), it responds under long-wave ultraviolet light at 365 nm with an intense green glow. The fluorescing species is the uranyl ion (UO₂²⁺) dispersed in the glassy network. The presence of uranium is confirmed instrumentally as well: at the dial surface a handheld counter reads a dose rate of about 0.57 µSv/h against a natural background of about 0.06 µSv/h — roughly a tenfold elevation. This is a white enamel carrying traces of uranium, not uranium ("vaseline") glass, in which uranium serves as a bulk colourant. The material is stable and, under ordinary conditions of display on a wall, safe.
The instrument is driven by a simple aneroid movement. At its heart is a corrugated capsule of German silver from which the air has been evacuated; the upper and lower membranes of the capsule are held under tension by a U-shaped flat spring. An interesting feature of the movement is that the pointer-arbor carrier is mounted directly on the edge of this U-spring. From the free edge of the spring a brass main lever also extends, acting on an angle lever that turns on pivot bearings; from the vertical arm of the angle lever a fusee chain runs to the pointer arbor. The instrument is calibrated by a screw at the back, which acts directly on the U-spring. The movement is mounted on a lacquered base and lies fully open to view through the aperture of the dial.
This barometer is not only a working instrument for measuring atmospheric pressure but also an expressive decorative object of its time, uniting precise mechanism with artistic finish.