This volume is an abbreviation and Simplification of college geology, published five years ago. Many technical details have been omitted, but the general purpose and scope Of the volume is not altered fundamentally. It is intended to present an outline of the essential features of geology with as few technicalities as the nature of the subject permits. Part I deals with geological processes, and with the materials on which they operate, while the theme of Part II is historical geology. The effort has been to treat these topics in such a way as to give the student not merely an understanding of the subject, but also an understanding of the means by which the present status of the science has been reached.