Early Floating-Movement Aneroid Joins the Collection
A rare aneroid barometer by R. Deutschbein, whose movement is not fixed to the case but floats on springs, has been added to the collection.
The collection has been enriched with an aneroid barometer made around 1860–1870 by Robert Deutschbein of Hamburg and retailed by H. Lehmann of Berlin. The wall instrument is housed in a turned, black-lacquered wooden case with a beaded brass bezel. Its card dial carries a scale in Paris inches with seven German weather terms, from STURM to BESTÄNDIG, and a Réaumur thermometer, both pointing to the years before the German states adopted the metric system.
The barometer's chief rarity lies inside. The movement sits in a zinc cup that is not screwed to the case at all: it rests on five compression springs on the back plate and is held under light preload against the bezel. This arrangement isolates the sensitive mechanism from the seasonal movement of the wooden case and takes up any play on its own, so that after some 160 years the instrument remains tightly assembled. The movement itself follows Vidie's system, with a deeply corrugated capsule, a brass main lever on knife edges, a helical spring and a fusee-chain transmission.
The catalogue entry describes the floating mounting, the dial and the movement in detail.