A452 Aneroid Barometer
4¾ inch diameter brass cased aneroid with a milled edge bezel. This type of bezel usually signifies an early aneroid barometer (invented 1844), and this fact is corroborated by the positioning of the hole for the adjustment screw on the reverse - at 6 o'clock instead of 3 o'clock for most - and by the serial number of the dial 6357.
This example has the earliest form of mechanism, with a printed card dial in French, all in perfect working condition. It also retain its original lacquer.
All early aneroid barometers were made in France, where they were invented, although so many were made for the weather-obsessed English, that many have English lettering and numbering.