Charles Edouard Guillaume (1861–1938)


Charles Edouard Guillaume was born in Fleurier in the Swiss Canton of Neuchatel on 15 February 1861. His father and grandfather were both clockmakers and his father’s family originally came from France. Guillaume went to grammar school in Neuchatel and attended the academy there, which went on to become the university, from 1877 to 1878.

Studies at the Federal Polytechnic Institute

In the winter of 1878, he embarked on a degree in mathematics (Section VI A) at the Federal Polytechnic Institute in Zurich), which he completed with a diploma as a teacher of mathematics on 4 August 1882 (ETH-Bibliothek, University Archives. Student Register EZ-Rek 1/1/4769).

Promoting and years in Paris

In 1883 he obtained a doctorate under Heinrich Friedrich Weber at the University of Zurich as the Polytechnic was not yet permitted to award doctorates. The very same year, Guillaume became an assistant at the International Bureau of Weights and Measures in Sèvres, near Paris, and from 1889 an adjunct. In 1888 he married Emilie Marie Anne Taufflieb from Germany, with whom he had three children.

Work for the International Bureau of Weights and Measures

He maintained close ties with the International Bureau of Weights and Measures in Paris for the rest of his life, even though he was offered a new physics chair at the Federal Polytechnic Institute in Zurich in 1901, which he turned down.

Präsidialverfügung Nr. 444a

ETH-Bibliothek, University Archives. Student Register EZ-Rek 1/1/4769

He became vice-director of the bureau in 1902, was director from 1915 to 1936 and remained an honorary director from 1936 until his death in Sèvres in 1938.


Guillaume's major achievement between 1886 and 1919 was the discovery of an iron-nickel alloy with near-zero expansion coefficients (invar) and a temperature-independent elasticity module (elinvar). The invention of these alloys and their research were of central importance to metrology and the clock industry and led to accurate information for thermostats as well as astronomical and other precision instruments. 

Nobel Prize in Physics and other awards

Charles Edouard Guillaume received the Nobel Prize for Physics (external link) in 1920, "in recognition of the service he has rendered to precision measurements in Physics by his discovery of anomalies in nickel steel alloys". 

The universities of Geneva, Neuchatel and Paris awarded him a Dr. h.c. He was President of the Société Française de Physique (external link), a corresponding member of the Académie des Sciences de Russie, an officer in the Legion of Honour and a member of numerous scientific societies in Europe.


Excerpt from Charles Eduard Guillaume’s letter to the mathematician Wilhelm Fiedler, 16 February 1902

ETH-Bibliothek, ETH Zurich University Archives, Hs 87: 1637


Guillaume's personal papers are housed at the Musée international d'horlogerie in La Chaux-de-Fonds. ETH Zurich University Archives hold C. E. Guillaume's student register, a letter to Wilhelm Fiedler, which is included in the latter’s personal papers, a biographical dossier and four honorary medals.