Réaumur scale

The scale Réaumur is a scale of Température conceived in 1731 by the Physicien and inventive French Rene-Antoine Ferchault de Réaumur (1683 - 1757), who gauged his thermometer between 0 and 80: the freezing point of water (value: zero) and the point of boiling of water (value 80).

Thus the unit of this scale, the Réaumur degree, is worth 5/4 of a Kelvin (or a Degree Celsius) and has same the zero as the Degree Celsius. Its symbol is generally °Ré , although one sees sometimes °r .

Another version (see discussion): The 80 of the Réaumur thermometer corresponds to the point of boiling of ethanol used to fill the tube of the thermometer, which corresponds to 78,5°C. There is thus quasi an equivalence: 100°Re = 98°C

The bond below illustrates an ancient thermometer, manufactured towards 1758 by George Adams (1709 - 1772) of Fleet Street, London, manufacturer of mathematical instruments for the king George III (starting from 1756). One sees four scales of temperature there of use at the time: Newton, of Lisle, Fahrenheit and Réaumur.

http://www.scienceandsociety.co.uk/results.asp?image=10413117

Other scales

External bonds

Conversion of dismantles Réaumur towards other units of temperature

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