Two Autograph Letters Signed "Augte Viquesnel" to an unnamed correspondent. In French [En Francais]

One page each, 8vo, minor stains and creasing, good condition. (1847) He describes a colleague, a "M. de La Roquette", for some years Secretary to the "Societe de geographie". whom he understands to be working on Turkey. "Je me [?] de lui indiquer un ouvrage Special sur Constantinople, son historie, ses monuments . . . " He wishes to avail himself of his correspondent's knowledge of "bibliographie" to help his colleague. ([1854?]) He has left with his correspondent's concierge two books loaned by the latter, a copy of the map which accompanies his book "Voyage dans la Turquie d'Europe" and a letter from "M. Elie[?] de Beamont "qui fera bonne figure dans votre collection d'autographes". He gives his response to the books which were lent to him. Note from BnF: "Géologue,ses travaux embrassent également la météorologie, la géographie, l'ethnographie. Membre (1833), trésorier (1843) et enfin président (1858) de la Société Géologique de France. Fondateur de la Société de météorologie de France (1850), membre de la Société Philomathique. Il s'occupe essentiellement de la partie continentale de la Turquie (Macédoine, Albanie, Thessalie...) et de la Thrace (1847-1848)." Two letters,