Jesse Ramsden - London. 18th Century mahogany Stick Barometer. c1770

Most unusual and finely constructed 18^th Century mahogany Stick Barometer, c1770.

The ‘swan-neck’ pediment, centred by brass urn finial, over silvered brass register plates, engraved with both English and French notations. The mercury thermometer, with adjustable gnomon, operated by impressively elaborate solid state rack-and-pinion mechanism, with Réaumur and Fahrenheit scales. The barometer scale, in both English and Paris inches, bearing adjustable wrap-around vernier, typical of the maker, with brass sleeve at the base to help to overcome the parallax problem. This mechanism is singularly robust, the precursor of Ramsden's classic simplified system. [See images]. The figured mahogany trunk conceals the barometer cistern tube, which terminates within elegant turned base.

Drawings of a similar, unsigned, barometer are illustrated in Goodison [‘English Barometers 1680-1860’]. See image.

 Ramsden was undoubtedly one of the finest and most innovative of barometer makers, achieving international acclaim even in his own lifetime.