With Biot, he completed the measurement of a terrestrial meridian arc and carried out the first precise measurements of the density of air and various gases. He was elected to the Académie des Sciences in 1809 and became its perpetual secretary in 1830. Member of the Provisional Government in 1848, as Minister of the Navy and War. He abolished slavery in the French colonies. Autograph manuscript s.l.n.d. 2 pp. in folio and signed letter. "F.Arago" to M. E. Plantamont in Geneva, Paris, November 12, 1849, 1 p. in-4. At the head vignette of the Institute, address. Text partly printed. Beautiful piece. Minute of a curious report concerning the professor of grammar and writing Laplace, interspersed with considerations on the study of grammar. Follow: acknowledgment of receipt of a work by Pantamont: "Astronomical observations" made at the Geneva observatory in the year 1847. "...Il est à sa connaissance ... qu'à une certaine époque les élèves se livraient dans l'école même à des scènes de débauche et qu'on n'employait aucun moyen pour les faire cesser …”.