This book is a detailed guide to help readers understand the equation of time - the discrepancy between time measured by astronomical observations and time kept by watches and clocks. It explains how to use the equation table to adjust watches and clocks and provides a description of a time-keeper that is useful for astronomical and industrial purposes. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.