This barometer and matching thermometer are after the celebrated model supplied by the marchand-mercier Simon-Philippe Poirier to Madame du Barry on 20 December 1769. Described as 'Un Baromètre & Thermomètre, de Passement, montés trés richement en bronze dorés d'or moulu et ornés de trois plaques de porcelaine de france à Enfants en miniature cy 1056l', this pattern was made with both two and three plaques. Interestingly, the lower plaque of the latter type commemorates the Transit of the Planet Venus, which was seen in Paris on 3 June 1769.
18th Century barometers and thermometers of this model are now in the Victoria & Albert Museum, London; the Metropolitan Museum of Art, New York; the Calouste Gulbenkian Foundation, Lisbon; the Louvre, Paris; and at Waddesdon (G. de Bellaigue, The James A. de Rothschild Collection at Waddesdon Manor: Furniture, Clocks and Gilt Bronzes, Fribourg, 1976, vol. I, no. 1, pp. 44 - 7).
A virtually identical pair with differing porcelain mounts, from The Alexander Collection, was sold, Christie's, New York, 30 April 1999, lot 178.