Henri BECQUEREL (1852-1908). 2 autograph manuscripts signed, - Lot 514

Henri BECQUEREL (1852-1908). 2 autograph manuscripts signed, Géométrie analytique, 1871-1872; 2short in-4 (22x17.5cm) notebooks of 177 and 178 leaves mostly written on both sides (plus qqs ff. volants and qqs ff. blancs), original dark-green cloth-backed boards (labels of paper manufacturer Mane 3, rue Linné), autograph title labels pasted on top cover. Course books for the Special Mathematics class at the Lycée Louis-le-Grand. The lectures are given by Gaston Darboux (1842-1917), whose name is noted at the head of the 2nd notebook. The pages are filled with cursive handwriting in black ink, with a few pencil passages, and numerous equations; they are illustrated with numerous sketches and diagrams in the margins. In the first notebook, the 14th f. reads: "Interruption de deux mois en raison de l'insurrection de 1871" (la Commune); on the next page, the "Discussion de l'équation du 3e degré en λ" is dated June 12, 1871. The first notebook (1871) opens with the words "La géométrie analytique ou application de l'algèbre à la géométrie est due à Descartes" ("Analytical geometry or the application of algebra to geometry is due to Descartes"), before the study of Coordonnées rectilignes ("Rectilinear coordinates"), and so on. The second book, entitled "Cours de Géométrie analytique 1872 1er cahier. H. Becquerel Mr Darboux professeur", opens with the chapter "Des coordonnées"; it ends with "Des quantités imaginaires", and a problem. A few loose sheets of drafts, mainly in pencil, have been slipped into the notebooks.