LOBACHEVSKY, Nikolai Ivanovich (1792-1856). Three works on non-Euclidean geometry.

Rare Kazan first edition, journal issues of Lobachevsky’s Imaginary Geometry and its sequel on the application to integers; plus the French edition of Lobachevsky’s final work, summarizing his discoveries in non-Euclidean geometry.

Comprises:
1. “Voobrazhaemaya geometriya” [Imaginary geometry]. Pages 3-88, in: Uchenye Zapiski Kazanskogo Universiteta [Proceedings of Kazan University], book 1. Kazan: University Press, 1835. With folding engraved plate for Lobachevsky’s work and folding letterpress tables for following works.
2. “Primenenie voobrazhaemoi geometrii k nekotorym integralam” [Application of Imaginary Geometry to some integrals]. Pages 3-166, in: Uchenye Zapiski Kazanskogo Universiteta [Proceedings of Kazan University], book 1. Kazan: University Press, 1836. With folding engraved plate for Lobachevsky’s work by L. Schewitz (browned). (Lacking lower wrapper, upper wrapper nearly detached.)
3. “Pangéométrie.” Pages 279-340 in: Sbornik Uchenye Statei… [Collection of Scientific Papers in Commemoration of the 50th Year of Imperial University of Kazan.] Kazan: University Press, 1856. (Some pale dampstain/spots internally. Tear from blank corner of lower wrapper.)
D. Sommerville, Bibliography of Non-Euclidean Geometry, pp. 26-27, and 33.

Together, three volumes. Octavo and large octavo. Illustrated with diagrams and formulae and engraved plates. Original printed wrappers. Overall only light wear except as noted above. Housed in three quarter morocco clamshell boxes.