6i6 CHARLES R. VAN HISE 



comparative simplicity and brevity. But so broad and complex is 

 the science of geology that a comprehensive statement of the principles 

 of the entire subject will necessarily be somewhat voluminous. 



Supplementary to the principles of geology, which are applicable 

 to the entire earth, there will be a long series of volumes of the geology 

 of different continents, the various political divisions of these conti- 

 nents, the states under those divisions, or even the minor areas, such 

 as counties or townships ; for so numerous are the facts of the science 

 that it requires a volume to discuss in detail even a small area. For 

 instance, to give the geology of a township with sufficient fulness 

 to make clear the earth-story there illustrated may require a good- 

 sized volume. 



We have seen that geology rests upon physics and chemistry as 

 its foundation; that it is closely related upon one side to astronomy, 

 upon another side to botany; that in its broader sense it includes 

 mineralogy; and that for its satisfactory development the aid of the 

 higher mathematics is needed. It is evident that the man who is to 

 advance geology must be broadly trained in science, and that he have 

 a firm grip upon the nature of energy, ether, and matter, and their 

 interactions. 



It is my conviction that when geology is placed in order under 

 the principles of physics and chemistry the science will have passed 

 through a greater revolution than at any previous time in its history. 



Charles R. Van Hise. 



University of Wisconsin. 



