JF Ptak Science Books
Henri Poincare. A collection of six papers on Fuchsian functions, including the three important contributions in volume 92 of the Comptes rendus.
"Sur les Functions Fuchsienne", in Comptes rendus hebdomadaires de l'Académie des sciences de Paris,, volume 92, February 14, 1881, 333-335; pp 395-396, February 21, 1881; pp 859-861, April 4, 1881. Three papers, in original wrappers, extracted from a larger bound volume
Offered with: Sur une nouvelle application et quelques applications importantes des fonctions fuchsiennes, Poincaré Henri, Comptes rendus hebdomadaires de l'Académie des sciences de Paris, 92, 1881, p. 859-861
“Sur les Fonctions Fuchsiennes.” Comptes rendus hebdomadaires de l'Académie des sciences de Paris, 1882, volume 94, pp 1166–1167. Extracted from a larger volume, without wrappers.
The six papers: $950
"Before the age of 30 he developed the concept of automorphic functions which are functions of one complex variable invariant under a group of transformations characterised algebraically by ratios of linear terms. The idea was to come in an indirect way from the work of his doctoral thesis on differential equations. His results applied only to restricted classes of functions and Poincaré wanted to generalise these results but, as a route towards this, he looked for a class functions where solutions did not exist. This led him to functions he named Fuchsian functions after Lazarus Fuchs but were later named automorphic functions..."--from the St. Andrews (UK) Math site, here.
See: Papers on Fuchsian Functions, translated by J. Stillwell, New York, Springer, 1985.
For Poincare commenting on his own creativity--especially in regards to Fuchsian functions, see his Foundations of Science (1908), here.
"The crucial idea came to him as he was about to get onto a bus, as he relates in Science and Method (1908):-
At the moment when I put my foot on the step the idea came to me, without anything in my former thoughts seeming to have paved the way for it, that the transformation that I had used to define the Fuchsian functions were identical with those of non-euclidean geometry."