MONGE (Gaspard) Géométrie descriptive, Paris: Mme Ve Courcier, 1820. -In-4, 257 x 200 : xx, 187 pp. 27 plates (of 28). Red morocco, framed with gilt and cold-stamped roulettes and gilt arms in the center of the boards, ornate ribbed spine, inner gilt roulette, gilt edges (period binding). Fourth edition of this fundamental work whose principles, new at the time, are for the most part still valid today. It was written for the students of the École normale created on October 30, 1794. The first edition appeared in 1799; this one is for the first time augmented by "La Théorie des ombres et de la perspective", extracted from the author's papers by M. Brisson: "Descriptive Geometry has two objects: the first, to give the methods for representing on a sheet of paper which has only two dimensions, namely length, width and depth, all the bodies of nature which have three, namely length, width and depth, provided nevertheless that these bodies can be rigorously defined. The second object is to give the way to recognize, according to an exact description, the shapes of bodies, and to deduce from them all the truths which result both from their shape and from their respective positions" (page 1). Copy illustrated with 27 folding plates out of the 28 required; the last one, showing the 53rd figure, is missing. EXEMPLAIRE EN MAROQUIN DE L'ÉPOQUE, AUX ARMES DE MARIE-THÉRÈSE CHARLOTTE DE FRANCE, DUCHESSE D'ANGOULÊME (1778-1851). Some wear and scuffing, splits at the hinge of the first cover, snags at the outer edge of the second cover, inner hinge of the first cover fragile. Provenance: Duchesse d'Angoulême, with her coat of arms on the boards and the label "Petit séminaire de Versailles. Établissement de S. A. R. Madame".