Un ouvrage de r f rence pour les astronomes, pr sentant les principes fondamentaux de l'astronomie th orique et pratique, ainsi que des tables et des formules pour faciliter les calculs. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United...