The elements of non-Euclidean plane geometry and trigonometry, by H. S. Carslaw.

This volume is produced from digital images created through the University of Michigan University Library's preservation reformatting program. 1. By the term Non-Euclidean Geometry we understand a system of Geometry built up without the aid of the Euclidean Parallel Hypothesis, while it contains an assumption as to parallels incompatible with that of Euclid.