Reaumur (°Re)

The Réaumur scale (symbol: °Ré) is a historical temperature scale introduced in 1730 by René Antoine Ferchault de Réaumur. It defines the freezing point of water as 0 °Ré and the boiling point as 80 °Ré, making one degree Réaumur equal to 1.25 kelvins. Widely used across Europe during the eighteenth and nineteenth centuries, it was gradually superseded by the Celsius scale, though it retained niche use in traditional European dairy and cheese production.