4-42-39. H. Poincaré à Felix Klein

[After 13 Oct. 1905]

Mon cher Collègue,

J’apprends par Darboux que le prix Bolyai vient de m’être décerné; je tiens à vous remercier de la part que vous avez prise personnellement à cette décision.

Veuillez, je vous prie, présenter à Madame Klein mes respectueux hommages et croire à mes sentiments dévoués,

Poincaré

ALS 1p. Nachlass Klein, Handscriftenabteilung, Niedersächsische Staats- und Universitätsbibliothek, Göttingen. Edited by Dugac (1989, 124).

Time-stamp: "27.05.2026 18:46"

Notes

• 1 The Bolyai Prize of the Hungarian Academy of Science was officially awarded to Poincaré on 18 December 1905, although Lebon’s biography dates the award to 18 April, 1905 (Lebon, 1912, 19). The jury was composed of Gyula König, Gusztáv Rados, Felix Klein, and Gaston Darboux, who presided. It decided in favor of Poincaré on 13 October 1905, according to Rados’ published report (which erroneously indicates the date as 13 Oct. 1901). Klein was chosen to write the report on the two candidates, David Hilbert and Poincaré, but according to Rados (1906) he renounced his duties, citing poor health, and was replaced by Rados. Klein wrote to Poincaré to explain the situation on or after 16 June, 1906 (§ 4-42-40); see also Poincaré’s reply (§ 4-42-41), and Rados’ report, published in April, 1906. On the origins of the Bolyai Prize, see Barna Szénássy, “Contributions to the history of the Bolyai-Prize”, 1995. Szénássy notes that Poincaré sent a letter to the Hungarian Academy of Sciences expressing his gratitude for the Bolyai Prize. The Archives of the Hungarian Academy conserves both this letter (§ 6-1-2093) and a draft of the president’s letter of 18 December announcing the prize (§ 6-1-2092).