Thermometer Reaumur

Unfortunately, errors in the way he fixed his points were criticized by many in the scientific community at the time, and even with modifications in the scale, instrument makers favored mercury-based thermometers. Reaumur s scale, however, lasted over a century, and in some places well into the late 20th century. 

Temperature is measured by such instruments as thermometers, pyrometers, thermocouples, etc., and by scales such as centigrade (Celsius), Fahrenheit, Rankine, Reaumur, and absolute (Kelvin). 

The simphcity of the relationship between the thermodynamic scale and the gas thermometer scale is due principally to the simple properties of rarefied gases, and also to the fortunate choice of mercury as thermometric substance by Celsius and Reaumur before the discovery of the gas laws. The coefficient of expansion of mercury happens to be almost exactly proportional to the coefficient of expansion of rarefied gases. All our thermodynamical relationships would have been very much more comphcated had water or alcohol, for example, or the resistance of a metal, been used for the definition of the practical scale of temperature. Their strict validity, however, would not have been affected. 

Reaumur, Rene-Antoine Ferchault de (1683-1757) French Philosopher, naturalist Rene-Antoine Reaumur was born in La Rochelle, France, in 1683. After studying mathematics in Bourges, he moved to Paris in 1703 at age 20 under the care of a relative. Like most scientists of the time, he made contributions in a number of areas, including meteorology. His work in mathematics allowed him entrance to the Academy of Sciences in 1708. Two years later, he was put in charge of compiling a description of the industrial and natural resources in France, and as a result developed a broad-based view of the sciences. It also inspired him into the annals of weather and climate with the invention of a thermometer and temperature scale. 

The encyclopedias, such as Americana, Britannica, Coilier sf Chamber sf and the German Brockhaus are generally strong on the subject of matches, especially the historical aspect, but sketchy on other branches of pyrotechnics. Nevertheless, they often make informative reading on side issues such as the history of the thermometer scales devised by Celsius, Reaumur, and Fahrenheit, the principles of optics, the phlogiston theory, etc. 

Comparison of thermometers Showing the relative indications of the Fahrenheity Centigrade and Reaumur thermometer scales... 

Reaumur s thermometer, containing alcohol, had really only one fixed point (the freezing point), and although described in 1730-1 was inferior to Fahrenheit s of 1724, which contained mercury and had three fixed points Reaumur does not seem to have known of Fahrenheit s prior publication. Reaumur determined the specific gravities of spirits of wine and the contractions on mixing alcohol and water. He described freezing mixtures of ice and salts and investigated the sparks struck from steel by flint. ... 

Rene-Antoine Ferchault de Reaumur (France) develops the alcohol thermometer. [1730]... 

A Reaumur thermometer measures temperature in degrees Reaumur. 

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