Originally published in 1859, this early work by English Mathematician Isaac Todhunter is both expensive and hard to find in its first edition. It contains a wealth of information on spherical trigonometry and includes chapters on Geodetical Operations, Polyhedrons, Spherical Geometry and much more. This fascinating work is thoroughly recommended for all students of mathematics looking to advance their knowledge of the subject. Many of the earliest books, particularly those dating back to the 1900s and before, are now extremely scarce. We are republishing these classic works in affordable, high quality, modern editions, using the original text and artwork.