Excerpt from The Problem of Volcanism The following chapters on phases Of the problem Of volcanism were prepared for the course Of Silliman Lectures at Yale University for the year 1914, and represent the lectures as they were then given, with slight elaboration in some parts. They were intended both for students Of geology and for others who, while not having made a Special study of the earth, are interested in its history and in theories respecting its origin and the possible causes Of volcanic activity at or near its surface. For this reason the attempt was made to avoid, as far as possible, the use of somewhat technical terms; and when their use seemed unavoidable, they were generally defined, at the risk Of making the treat ment appear elementary. It seemed desirable also to reduce the problem to its simplest elements, and to attempt to trace each back to its fundamental basis, or to express it in terms Of elemental principles. It is hoped that in this manner the discussion may appeal to a wider range Of readers than would be interested in a more technical treatment Of the subject. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.