European Mercury Thermometer (Réaumur/Celsius)

This European atmospheric mercury thermometer features both Réaumur scale and Celsius (centigrad) scale. It is displayed in an ornate, carved Oak frame, with an etched brass face, and a German-silver cage protecting the bulb. This thermometer ranges from -20 to 50 (C) and 0 to 40 (Re).

The Réaumur scale was developed in 1730 by a French naturalist René Antoine Ferchault de Réaumur. This scale was popular in 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 almost completely phased out by the start of the 20th century and replaced with the Celsius scale. The decline in popularity was largely in part by the French adopting the Celsius scale as a part of the metric system in the late 18th century.

This thermometer dates between the mid/late 18th century to the mid 19th century. It existed as a way to use both units of temperature, during the transitionary period of switching from the degree Réaumur to degree Celsius.

Dimensions: 20 cm x 6 cm

Weight: 3.4 oz.