REVIEIVS l^'J 



The section which treats of the glacial epoch has been rewritten and 

 enlarged, and a number of cuts have been added. Professor Fairchild 

 has shown much skill in preserving the spirit and style of the book, 

 and yet by a series of deft touches he has been able, in most instances, 

 to bring the subject-matter up to date and well to the forefront of the 

 rapidly advancing science. Henry Landes. 



Geology. By Thomas C. Chamberlin and Rollin D. Salisbury. 

 Vol. I, Geologic Processes and Their Results; Vol. II, 

 Earth History. (American Science- Series — Advanced 

 Course.) Henry Holt & Co., 1903. 



Volume I is just issuing from the press. Volume II is to follow 

 closely. The following extract from the preface indicates the con- 

 trolling ideas of the authors : 



In the preparation of this work it has been the purpose of the authors to 

 present an outline of the salient features of geology, as now developed, 

 encumbered as httle as possible by technicalities and details whose bearings 

 on the general theme are unimportant. In common with most writers of text- 

 books on geology, the authors believe that the subject is best approached by 

 a study of the forces and processes now in operation, and of the results which 

 these forces and processes are now bringing about. Such study necessarily 

 involves a consideration of the principles which govern' the activuies of 

 geologic agencies. These topics are piesented in Vol. I, and prepare the 

 way for the study of the history of past ages, which is outlined in Vol. II. 



The general plan of the work has been determined by the experience of 

 the authors as instructors. Little emphasis is laid on the commonly recog- 

 nized subdivisions of the science, such as dynamic geology, stratigraphic 

 geology, physiographic geology, etc. The treatment proceeds rather from the 

 point of view that the science is a unit, that its one theme is the history of the 

 earth, and that discussions of dynamic geology, physiographic geology, etc., 

 apart from their historical bearings, lose much of their significance and 

 interest. The effort has, therefore, been to emphasize the historical element, 

 even in the discussion of special themes, such as the work of rivers, the work 

 of snow and ice, and the origin and descent of rocks. This does not mean 

 that phases of geology other than historical have been neglected, but it means 

 that an effort has been made to give a historical cast to all phases of the sub- 

 ject, so far as the topics permit. 



Throughout the work the central purpose has been, not merely to set 

 forth the present status of knowledge, but to present it in such a way that the 

 student will be introduced to the methods and spirit of the science, led to a 

 sympathetic interest in its progress, and prepared to receive intelligently, and 



