Rene Reaumur. Engraving of Rene Antoine Ferchault de Reaumur (1683-1757), French technologist and naturalist, making his first thermometer in 1731. Reaumur (at left) devised a thermometer which used a mixture of ethanol alcohol & water that expanded up a tube as it warmed up and so could be measured against a scale to give the temperature. Reaumur devised a complicated scale in order to compensate for inconsistencies in the expansion of the mixture at different temperatures. The thermometer was marketed with 80 degrees between the melting and boiling points of water. This Reaumur scale" eventually fell out of use in favour of those devised by Fahrenheit and Celsius."