LEGENDRE, ADRIEN MARIE.

Éléments de géometrie, avec des Notes; Douzieme Édition.

Paris, Firmin Didot, 1823. Cont. hcalf. Blindtooling to back. (6),431 pp. and 14 folded engraved plates.

Importent 12th edition of Legendre's "Elements". He worked on the Euclidean parallell postulate over a period of about 20 years, and his various results with and attacks on the problem, appeared in the different editions of his "Elements". This 12th edition having L.'s demonstration of angle sum by a series of triangles with the same area and angle-sum, not in the previous editions. (Sommerville: Non-Euclidean Geometry 1823:Legendre).

Order-nr.: 31111