Réaumur (English name) René-Antoine Ferchault de Réaumur

French scientist and engineer. Born into a distinguished family in La Rochelle, he lost his father when he was just a year old and was raised by his mother and relatives. In 1703, he went to Paris to study, first mathematics and then zoology, and thereafter became involved in a wide range of experimental sciences and practical technologies. His sharpness and breadth of observation in natural history is said to be comparable to that of Charles Darwin, and his contributions to entomology and embryology are highly regarded. Meanwhile, after becoming a member of the Academie des Sciences in Paris in 1708, he devoted himself to the editing of the Academie's project, the Encyclopedia of Industries, and carried out detailed research on steel, tinplate, and ceramics in particular. Among his other notable achievements is the invention of the thermometer scale, which indicates that if the volume of a liquid in a glass tube at the freezing point is 1000, if it increases to 1001, it is expressed as 1 degree, if it increases to 1002, it is expressed as 2 degrees, and so on. As a result, the boiling point of alcohol was determined to be 80 degrees, but due to a misinterpretation, a scale representing the boiling point of water at 80 degrees was named after him and called the Centigrade degree (symbol).

[Seiji Takada]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

フランスの科学者・技術者。ラ・ロシェルの名門に生まれたが、生後1年余りで父を失い、母や親戚(しんせき)の手で育てられた。1703年パリに遊学、まず数学、ついで動物学に接し、それ以後実験的な諸科学、実用的な諸技術に幅広く携わることになる。博物学における彼の観察の鋭さと広さは、C・ダーウィンのそれに匹敵するといわれ、昆虫学、発生学での貢献は高く評価されている。一方、1708年にパリ科学アカデミーの会員になってからは、アカデミーの事業である『産業百科全書』の編集に熱中し、とくに鉄鋼、ブリキ、陶磁器に関し詳細な調査を進めた。その他の業績のうち著名なのは温度計の目盛りの考案であって、ガラス管内の液の氷点での体積を1000としたとき、それが増して1001になれば1度、1002なら2度……と表すことにした。その結果、アルコール沸点が80度となったが、誤伝されて水の沸点を80度とする目盛りに彼の名が付せられ、列氏度（記号）とよばれた。

［高田誠二］

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