Author(s): Willi H. Hager; Oscar Castro-Orgaz
Linked Author(s): Willi H. Hager, Oscar Castro-Orgaz
Keywords: French Academy of Sciences; Paris; Biography; French scientists; Hydromechanics; Open-Channel Flow
Abstract: The Library of the French Academy of Sciences, Paris, includes a hand-written correspondence between two of the masters of engineering and physical sciences of the 19th century, namely Adhémar Jean-Claude Barré de Saint-Venant (dSV, 1797-1886) and Joseph Valentin Boussinesq (JB, 1842-1929). Some 600 letters were written between 1868 and 1885. Given the scientific advances made during these days that were initiated by the two masters, and the development of a certain topic until final publication, the present authors considered it appropriate to deal with the contents of the letters in selected papers. Three papers were published in the Comptes Rendus Mécanique of the Academy of Sciences, and another three papers are under preparation. The purpose of this paper is to allow interested readers for a closer look at the written exchange between dSV and JB. Based on a short paper written by JB in 1868, dSV contacted him by letter in which certain clarifications were addressed. This marked the origin of a personal, friendly relation between two outstanding scientists of the 19th century in the field of free surface hydraulics. dSV was then president of the Mechanics Section of the Academy, controlling to a large extent its publications. He could have been the grand-father of the young JB. The latter then was a College teacher at Gap in the French Savoy, trying to obtain a better professional position. JB, a self-taught person, has worked on all fields of physics except for electro-dynamics, whereas dSV was the master of mechanics, particularly in the theory of elasticity. Aged by then 70 years, he felt that JB could be for him an excellent colleague, who could help him in the solution of scientific problems. In turn, JB realized that dSV could be the optimum person for him to expand studies to engineering problems and that he could provide him a better professional position. Accordingly, both scientists took a deep interest into each other and developed a friendship lasting up to the death of dSV. Note here that JB was elected Member of the Academy of Sciences ten days after dSV’s passing, an event for which the two had worked over years to finally succeed. The topics dealt with in the Correspondence do not only include applied mathematics and theoretical physics, or hydromechanics and the elasticity theory, but also issues relating to religion and ethics, aspects of the two families associated with visits of JB to the home of dSV. Many of these so far hardly touched aspects are considered in this communication for the IAHR World Congress 2021 in Granada.