Precision measuring instruments were highly sought-after pieces in the 18th century, being the fruit of the scientific advances made in an era when confidence in man’s intellectual abilities and the power of reason took on enormous importance. The king and the court were not adverse to this tendency, using such instruments to decorate their salons and thereby conferring on them the status of works of art.

This barometer-thermometer was made by Claude-Siméon Passemant, one of the greatest inventors and builders of scientific instruments of the time. The two instruments – the barometer and the thermometer – are housed in a chased and gilded bronze case decorated with ribbons, flowers, fruits, garlands and scrolls. This decoration also includes three porcelain plaques signed by Charles-Nicolas Dodin, a renowned figure painter attached to the Royal Manufactory of Sèvres who created various plaques for the decoration of furniture and scientific instruments as well as dinner sets and vases.

The three plaques feature motifs related to the function of the piece. The uppermost plaque, which is oval in shape, contains a green reserve with a gilded frame within which a cupid is shown sitting on a cloud, holding a telescope. In the central plaque, which is enclosed by the same type of frame, a child is depicted in a bucolic scene holding a drawing compass and an armillary sphere. In the lower plaque, which is smaller and has no reserve, a book and several scientific instruments are shown resting on a cloud. The book is open at a page on which we read the words Connaissance des Temps.

The enamelled faces of the two instruments contain information about the weather.