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.