ANEROID POCKET BAROMETER E. Malacrida Marseille Stamped PHBN Circa 1890 France

M&R170

ANEROID POCKET BAROMETER
Signed E. Malacrida Marseille
Stamped PHBN (Pertuis, Hulut, Bourgeois, Naudet)
Circa 1890
France

The dial
The circular silvered brass dial has a barometer scale with Arabic numerals (53-79 cm Hg). The rotating outer edge serves as an altimeter and has a scale in hundreds from -4 to 30. Above the centre is the indication BAROMÈTRE HOLOSTÉRIQUE with the mark PHBN in between, which stands for Pertuis, Hulut, Bourgeois, Naudet. The name of the retailer E. Malacrida Marseille is indicated in the lower part of the dial.

The case
The circular gilt brass case has a suspension eye at the top. The back has the stamped mark PNHB in the centre.

Height: 8.5 cm. (including the suspension eye).
Diameter: 7cm.
Depth: 2.5 cm.

Literature
Bert Bolle, Barometers in beeld, Chapter 15.

The maker
PNHB refers to the house of Naudet. The name Holostérique was coined and registered by Naudet in 1860 when the company was founded by four industrialists, namely Pertuis, Hulot, Bourgeois and Naudet. It means that no mercury is used in the device. The company quickly became known in the field of mechanical barometers. They use the PHBN stamp and the company still exists.

Holosteric or aneroid barometer:
The first aneroid barometers came into production in 1847, after the inventor Vidi was granted a patent in 1844. They contain an almost vacuum, round flat drum with ribbed top and bottom. A steel spring ensures that the atmospheric air pressure does not compress the box. Due to the air pressure fluctuations, the top of the box moves up and down over a small distance. These minuscule movements are first magnified via a lever system, after which they are transferred to a rotating pointer. This system had several advantages over the hitherto usual mercury barometer: low vulnerability, easy handling, insensitivity to movements at sea, small size and an easily readable.