Des quantités positives et negatives en géométrie
A mathematical treatise on positive and negative quantities in geometry by L. A. comte de Pourtalès, published at Neuchâtel by J. Gerster in 1847 for students and teachers of algebraic geometry. The plates are fine-line engraved diagrams: numbered figures of circles, intersecting lines, angle arcs with Greek labels, and skeletal cube axonometrics, usable as sparse linework and lettered geometric motifs.
