DE LA CAILLE Nicolas-Louis, Abbé (1713-1762). "Leçons élémentaires de Mathématiques ou élémens dAlgèbre et de Géométrie / Nouvelle Edition revue, corrigée & augmentée", a Paris, H. L. Guerin & L. F. Delatour, M.DCC.LXIV (1764). In-8o de 5 ff., 277 (2) pp., 6 folding diagrams. Nicolas-Louis de La Caille (1713-1762), a student of Cassini at the Paris Observatory, is best known for his astronomy work on the southern hemisphere. He was one of the most important astronomers of the 18th century, while being a professor of mathematics at the Mazarin college. Anxious to facilitate the learning of his students, he wrote his books in French rather than in Latin.The first edition of the "Elementary Lessons in Mathematics; or Elements of Algebra and Geometry" was published in 1741. The book was a bestseller and reprinted about thirty times in different languages. These famous lessons proceed from the simplest to the most complex elements, from the definition of mathematics and addition to the rectification of curves and tangents and show patient pedagogy. Contemporary full calf binding, 5 nerves spine, decorated with gilt fleurons and title; rubbed and bumped over extremities. Marbled endpapers, coloured edges; spatial spotting and foxing, but clean and tight. Quérard IV, p. 353. Good copy.