Guillaume, Charles Édouard

(b. Fleurier, Switzerland, 15 February 1861; d. Sèvres, France, 13 June 1938)

metallurgy, physica.

Guillaume’s father, Édouard Guillaume, returned to Switzerland, his family’s original home, from London, where he had managed a clockmaking firm. His knowledge of science was considerable, and he was his son’s first teacher. The latter was admitted at the age of seventeen to the Zurich Polytechnikum, where he studied not only the prescribed scientific subjects but also German and Frencch literature. He used to say that François Arago’s Éloges académiques had exerted a profound influence on him.

In 1883 Guillaume entered the International Bureau of Weights and Measures at Sèvres,, near Paris. He remained there throughout his career and became its director. In 1911 he was elected a corresponding member of the physics section of the Académie des Sciences.

Guillaume’s first works were devoted to the mercury thermometer; upon completion of these studies he published a treatise on thermometry which made available to physicists the methods perfected by the International Bureau of Weights and Measures. He next participated in the preparation of the national meters, a fundamental work which marked the origin of modern metrology and permitted the presentation in 1889, at the first Conference on Weights and Measures, of the complete collection of standardized meters destined for the different countries.

Since 1890, Guillaume was led to undertake investigations on metal alloys. Studies had been made at Sévres on a ferronickel (an alloy of iron with 24 percent nickel and 2 percent chromium) that had just been created at the Imphy Works in Nièvre. This alloy was more expansible than the iron or the nickel composing it. While studying an alloy containing slightly more nickel, Guillaume observed that this small variation in composition resulted in an alloy less expansible than the constituent metals. He undertook a methodical study of ferronickels and showed that with 36 percent nickel, one obtained an alloy, which he called invar, that expanded ten times less than iron and that even possessed a zero coefficient of dilatation after appropriate tempering, drawing, and rolling.

This alloy immediately found numerous applications, particularly in clockmaking. Guillaume also helped to solve another problem—compensation in ordinary watches—through his discovery of elinvar, an alloy whose elasticity does not vary with temperature.

These successes gave Guillaume an important role in the International Physics Congress, held in Paris in 1900, and earned him the 1920 Nobel Prize in physics. Moreover, he had the pleasure of seeing that his work would be brilliantly continued at the International Bureau of Weights and Measures by the physicist Albert Pérard, who succeeded him as director. In addition, Albert Portevin and Pierre Chevenard obtained very satisfactory results in developing his researches on nickel alloys.

BIBLIOGRAPHY

Guillaume’s works include “Sur la dilatation des aciers au nickel,” in Comptes rendus hebdomadaires des séances, de l’Académie des sciences, 124 (1897), 176; “Recherches sur les aciers au nickel. Proptiétes métrologiques,” ibid., 752; “Recherches sur les aciers au nickel. Propriétés magnétiques et déformations permanentes;” ibid., 1515; Recherches sur les aciers au nickel. Dilatations aux températures élevées; résistance électrique,” ibid., 125 (1897), 235, errata, p. 342; “Recherches sur les aciers au nickel. Variations de volumes des alliages irréversibles,” ibid., 126 (1898), 738; “Nouvelles recherches sur la dilatation des aciers au nickel,” ibid., 136 (1903), 303; “Changements passagers et permanents des aciers au nickel,” ibid., 357; “Variations du module d’élasticité des aciers au nickel,” ibid., 498; “Sur la théorie des aciers au nickel,” ibid., 1638; L’anomalie de dilatation des aciers au nickel,” ibid., 152 (1911), 189; “Coefficient du terme quadratique dans la formule de dilatation des aciers au nickel,” ibid., 1450; “Modification de la dilatabilité de l’invar par des actions mécaniques ou thermiques,” ibid., 163 (1916), 655; “Écrouissage et dilatabilité de l’invar,” ibid., 741; “Homogénéité de dilatation de l’invar,” ibid., 966; “Recherches métrologiques sur les aciers au nickel,” in Travaux et mémoires du Bureau international des poids et mesures, 17 (1927); “Les anomalies des aciers au nickel et leurs applications,” in Revue de métallurgie, 25 (1928), 35.

Georges Chaudron