Regarded as a textbook of geology, the present work offers some departures from existing examples. Though it has been customary to combine in a single text historical with dynamical and structural geology, a tendency has already become apparent to treat the historical division apart from the others. Again, a desire to treat the science of geology comprehensively has led some authors into including so many subjects as to render their texts unnecessarily encyclopedic and correspondingly uninteresting to the general reader. It is the author’s belief that there is a real need for a book which may be read intelligently by the general public, and it must be recognized that the beginner in the subject cannot cover the entire field by a single course of readings. The present work has, therefore, been prepared with a view to selecting for study those dominant geological processes which are best illustrated by features in northern North America and Europe. It is this desire to illustrate the readings by travels afield, which accounts for the prominence given to the subject of glaciation; for the larger number of colleges and universities in both America and Europe are surrounded by the heavy accumulations that have resulted from former glaciations. Emphasis has also been placed upon the dependence of the dominant geological processes of any region upon existing climatic conditions, a fact to which too little attention has generally been given. This explains the rather full treatment of desert regions, of which, in our own country particularly, much may be illustrated upon the transcontinental railway journeys. More than in most texts the attempt has here been made to teach directly through the eye with the efficient aid of apt illustrations intimately interwoven with the text. For such success as has been reached in this endeavor, the author is greatly indebted to two students of the University of Michigan,—Mr. James H. Meier, who has prepared the line drawings of landscapes, and Mr. Hugh M. Pierce, who has draughted the diagrams. Though credit has in most cases been given where illustrations have been made from another’s photographs, yet especial mention should here be made of the debt to Dr. H. W. Fairbanks of Berkeley, California, whose beautiful and instructive photographs are reproduced upon many a page. As given at the University of Michigan, the lectures reflected in the present volume are supplemented by excursions and by so much laboratory practice as is necessary to become familiar with the more common minerals and rocks, and to read intelligently the usual topographical and geological maps. In the appendices the means for carrying out such studies, in part with newly devised apparatus, have been indicated.