Réaumur Scale

a practical temperature scale proposed in 1730 by R. A. de Réaumur. The unit of the Réaumur scale is the degree Réaumur (°R); 1°R is equal to l/80th of the temperature interval between the melting point of ice (0°R) and the boiling point of water (80°R)—that is, 1°R = 1.25°C. The Réaumur scale is no longer used.