Barometers Realm

The gauge dial, measuring 54 mm in diameter, is meticulously marked from 0 to 99, with hatch marks for each unit and numbers for multiples of 10. The upper portion of the dial bears the inscription "Mètres", while the lower part is marked "Société Anonyme des Établissements" and signed by the renowned maker, Jules Richard, Paris. The hands are crafted from blued steel, adding both functionality and elegance. A side-mounted dial brake and a re-set aperture at the verso ensure ease of use.

At the connection point between the fan and the gauge, the metal bears the iconic RF logo — a hallmark of the renowned enterprise Richard Frères — along with the patent mark Breveté SGDG and the city name Paris.

The anemometer is housed in a protective wooden case covered in leather, measuring 20 x 11 x 7.5 cm. The case features a hinged lid, two metal fasteners, and a carrying handle. Inside, the case is lined with rich purple fabric and includes a folding pocket for documents. Among the documents are the Calibration Protocol for the device, dated 1954, and a classified instruction manual issued by the Dutch Department of Defense. Additionally, the case contains a nickel-plated tuning key and a bottle of oil for maintenance.

The anemometer is designed to measure the average velocity of directed air streams in industrial settings and other environments, using a stopwatch for timed observations. The wind sensor, a lightweight impeller mounted on a pipe shaft, rotates on a fine steel string inside the shaft, driven by air currents. The rotation is transmitted through a worm gear to the counter reducer, which translates the motion into readings on the gauge.

This instrument not only reflects remarkable engineering and craftsmanship but also serves as a historical artifact, encapsulating mid-20th-century technological advancements in air velocity measurement.