European Mercury Thermometer, c.1795-1835 (Réaumur & Celsius)

This antique atmospheric mercury-type thermometer interestingly features both Réaumur and Celsius (centigrade) scales. Thermometer is displayed in a fine, ornately carved Oak frame with an etched brass face, and German-silvered cage protecting the glass bulb. This thermometer ranges from -20 to 50 (C) and 0 to 40 (Re). Circa 1795-1835.

The Réaumur scale was developed in 1730 by French naturalist, René Antoine Ferchault de Réaumur. This scale was popular throughout Central Europe, specifically France, Germany, and Russia. It was commonly used within the scientific community and industries such as brewing, distilling, and dairy production. The Réaumur scale was most popular from 1730-1800. The decline in popularity was largely due to the French Revolutionary Guard adopting Celsius as part of the Metric System, introduced in 1791.

This thermometer dates between 1795-1835. It existed as a way to use both units of temperature, during the transitionary period of  the degree-Réaumur to the degree-Celsius. It's combination of hand-etched, ornate monography with the rigidity of the scale lines/numbers on the brass face lend further credence to this timeframe. The print-engraving technique evident of rigid/straight lines seen in this scale were introduced in 1790. Furthermore, such meticulous hand-engraving combined with this specific style of curved-lettering is conservatively indicative of a pre-1835 piece.

Dimensions: 20 cm x 6 cm

Weight: 3.4 oz.