Its particularity lies in the system allowing the measurement of atmospheric pressure: this is not a vacuum capsule, which is usually found, but a Bourdon tube. The Bourdon tube takes its name from its inventor, Eugène BOURDON [1808-1884]. At the time, Eugène Bourdon's main competitor was Lucien Vidie (inventor of Vidie capsules). He even suffered a loss in a lawsuit against Lucien Vidie. The Bourdon tube, in addition to being used as a barometer, is also still used in manometers, which allow the pressure of a fluid to be measured. The Bourdon tube is the main element of the barometer of the same name, it is a circular metal tube which has the specificity of deforming slightly depending on the atmospheric pressure. This system, once assembled with a simple but ingenious mechanism and an indicator, can then display pressure variations on a dial. We obtain the same operation as a “classic” vacuum capsule barometer. Bourdon barometers are much rarer than those of Vidie, so their price is often higher. The barometer is in working condition. Will be packed with the utmost care and sent insured and registered by post, colissimo.