A Nomogram for Solving Spherical Triangles

摘要

A nomogram is presented which converts between celestial and horizon coordinates for a single latitude. In 8 by 10 inch size the accuracy aver¬ages half a degree. It may also be used to find range and bearing of any point on the earth from its latitude and longitude. The construction is easy since it consists of two straight lines and a circle graduated according to simple rules. Examples of use, directions for construction, and theory are included.