The
Réaumur is a unit of
temperature named for
René Antoine Ferchault de Réaumur, who first proposed it in 1731. The freezing point of water is 0° Reaumur, the boiling point 80° Reaumur. Hence a degree Reaumur is 1.25 degrees
Celsius or
kelvin.
The Reaumur scale is still used in some parts of Europe, but today it is in most places of mainly historical significance.