Book excerpt: This unique book Spherical Trigonometry is the first and only book with comprehensive and accurate illustration of diagrams of spherical triangles according to given and computed angles that is not found in any similar books in circulation. Part 1, 2, and 3 consist of Definitions.Computations on spherical triangle areas, right, polar, quadrantal, oblique, and spherical triangles. Use of Napier's Rules, Laws of Sines and Cosines, The Six Cases, Delambre's and Gauss' Formulas. Part 4 consists of its application to sea and air navigation, statute and nautical mile, geographical coordinates of cities, computation of distances between cities of countries, time difference between countries, bearing, heading, and course.