Correspondence between de Saint-Venant and Boussinesq 3: de Saint-Venant's professional career and private life.

Adhémar Barré de Saint-Venant has significantly contributed to the engineering sciences. His professional career can be divided into mainly two parts. Namely, until 1852, he made contributions through his engineering works as a practicing engineer and his scientific works at two French academic institutions. He retired at an early age from these institutions, moving with his family to the family castle close to the city of Vendôme, 170 km southwest of Paris. Saint-Venant is particularly known for his research in elasticity, his formulation of the shallow water equations, his hydraulic works, and his interest in the history of technology. He was a person who cared for the professional advance of his colleague Boussinesq, both by posing him relevant problems, thereby elevating Boussinesq's name as an outstanding physicist, and by his wide connections in the French academic world to which the shy and modest Boussinesq was introduced by his master. The Correspondence allows for an alternative insight into the relationship between these two scientists, which also includes their families. When the Correspondence started in 1868, Saint-Venant had already passed the age of 70. Given this age, he felt himself no longer able to tackle new problems by himself alone. He found in Boussinesq an extraordinary pupil and colleague who mainly supported his master in advancing a large number of scientific questions. The Correspondence thus evidences the sometimes long developments of a final solution to a problem of common interest. In addition, the Correspondence also includes questions on ethics, religion, and the history of sciences. The role of their wives is also highlighted because they had a strong impact on the social relation between the two families. This work is concluded with hardly seen obituaries of more private than professional nature, by which the many facts not included in the Correspondence are evidenced. In addition, a number of letters written by the eldest son of Saint-Venant to Boussinesq are presented, in which the fate of the many unfinished papers of Saint-Venant is discussed. [ABSTRACT FROM AUTHOR]