Celestial navigation refers to the ancient practice of position fixing that allows a navigator to move through a space without the need of estimated calculations to know what their position is. Usually, the Sun is used for this, but the Moon, Polaris, a planet, or one of the numerous other navigational stars can also be used. First published in 1918, this book contains a detailed guide to using astronomy for navigation at sea, originally published as a textbook to be used by the U. S. Naval Academy. Contents include: "General Definitions", "List of Navigational Instruments and Books Usually Provided", "The Compass", "The Earth's Magnetism and the Elements of that Magnetism", "Finding the Deviation by Reciprocal Bearings, by Bearings of a Distant Object, by Time Azimuths, by Ranges", "Mathematical Theory of Compass Deviations", etc. Many vintage books such as this are increasingly scarce and expensive. It is with this in mind that we are republishing this volume now in an affordable, modern, high-quality edition complete with the original text and artwork.