This biography of Agnes Mary Clerke and Ellen Mary Clerke offers a detailed look at the lives and achievements of these sisters, who were pioneering figures in the field of astronomy. Agnes Mary was a respected astronomer and science writer, while Ellen Mary was a skilled observer and artist who created many stunning astronomical illustrations. This book examines their contributions to the field of astronomy and their impact on the scientific community. 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.