Reaumur - Definition


Reaumur - Definition

This article is about the temperature scale. R�aumur is also the name of a commune in the Vend�e d�partement, in France.

The Réaumur is a unit of temperature named after Ren� Antoine Ferchault de R�aumur, 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 kelvins. The Reaumur temperature scale is also known as the "division octogesimale" or "octogesimal division".

R�aumur's thermometer was constructed on the principle of taking the freezing point of water as 0°, and graduating the tube into degrees each of which was one-thousandth of the volume contained by the bulb and tube up to the zero mark. It was the dilatability of the particular quality of alcohol employed which made the boiling point of water 80°; and mercurial thermometers the stems of which are graduated into eighty equal parts between the freezing and boiling points of water are not R�aumur thermometers in anything but name.

The R�aumur scale saw widespread use in Europe, particularly in France and Germany, but was eventually replaced by the Celsius scale. Today it is of historical significance.

See also