Double Blue Glass Inkwells and Thermometer Desk Set

This desk set is made of brilliant blue cut glass, with a rectangular base holding two hinged inkwells and a central cut glass obelisk that houses a mercury thermometer.

The glass color is a rich, vivid azure blue. In color theory, azure is a color between cyan and blue on the visible spectrum. It is often described as the color of a clear, brilliant sky. The term comes from the gemstone lapis lazuli. The inkwell’s color appears to be a deep, saturated version of this shade.

Thermometer Scales

The thermometer is marked with “C” for Centigrade (now known as Celsius) and “R” for Réaumur. The Réaumur scale, also known as the “octogesimal division,” was developed by René Antoine Ferchault de Réaumur in 1730. On this scale, the freezing point of water is 0°R, and the boiling point is 80°R. This scale was widely used in Europe, particularly in France, Germany, and Russia, until the late 19th and early 20th centuries.

Country of Origin

Given that the thermometer uses the Réaumur scale, which was a French invention and was very common in France until the adoption of the metric system and the Celsius scale, it is highly likely that this desk set is from France. The style and the cut glass are also consistent with French craftsmanship from the late 19th or early 20th century.