SAVARY (Félix). - Lot 206

SAVARY (Félix). 1797-1841. French mathematician and astronomer. Professor at the École Polytechnique, member of the Académie des Sciences and the Bureau des Longitudes. Important L.A.S. "F. Savary" to mathematician Louis-Benjamin Francœur. Verneuil, August 9, 1839. 4 pp. in-8. Beautiful and important scientific letter devoted to tidal calculations, lunar theories and astronomical tables. Savary responds to Francœur's observations on the tables published in the Annuaire and develops at length his thoughts on the calculation methods inherited from Laplace and Bernoulli: "This table calculated according to Laplace's old formulas is basically just Bernoulli's." The scientist discusses in detail the parallaxes, declinations and lunar parameters used in tidal calculations, while acknowledging the limitations of existing models: "When we want to go further, it's the formulas themselves and Laplace's theory itself, both ancient and recent, that need to be modified or completed. Savary also refers to a vast body of personal work based on tens of thousands of observations: "I convinced myself [...] by discussing [...] some 50,000 observations. It's a work that has brought me bad luck, because every time I wanted to finish it [...] I found myself sidelined by other occupations." He wished to maintain the utmost discretion regarding this still unfinished research, and asked Francœur not to divulge it: "It remains for me to beg him not to give them any publicity [...] each time it has always made me want to give them up." A scientific document of the utmost interest, testifying to the theoretical debates on celestial mechanics and tidal prediction at the Bureau des Longitudes in the 1830s. A fine letter from one of the great French mathematicians of the July Monarchy, Ampère's collaborator and a pioneer in the calculation of stellar orbits. A few traces of folding and minor marginal blemishes. Very good condition.