This volume traces the history of the Lowell Observatory, a research institution in Flagstaff, Arizona. Established in 1894, the observatory has played a key role in advancing our understanding of the solar system and beyond. The book includes detailed accounts of astronomical discoveries, as well as profiles of some of the pioneering scientists who worked there. 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.