Published in 1920, this book covers the physical properties of radiation. It is a landmark in the field of radiation physics and provides a comprehensive overview of the subject. The authors present their findings in a clear and concise manner, making this book accessible to readers with a range of scientific backgrounds. 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.