ACADEMY OF SC.ENCES] POWELL'S SURVEY 109 



In the meantime, the progress made in the half century past should surely encourage our 

 physiographers as they march into the future. Let them glory in the remembrance that, 

 under the leadership of our western explorers, and especially under the inspiration of the 

 philosophical observer who pointed out the way in which the slopes of the land must gradually 

 organize themselves in a relation of interdependence under the laws of structure and of divides, 

 an American school of physiography and hence of geography came to be developed. This 

 school was a natural outgrowth of the impulse toward new methods of thought given by the 

 exploration of a region in which underground structure and surface form were manifestly 

 related. If the more recent progress of this school be less rapid than its earlier progress, that 

 is only because the young geographers who entered the subject from the physiographic side 

 have so seldom carried their work far forward into the human and economic aspects of the 

 science; just as those who later entered it from the historic or economic sides have as a rule 

 failed to apprehend the full meaning of its physiographic basis. The future development of 

 scientific geography in America, the earlier stages of which profited so greatly from Gilbert's 

 physiographic leadership, will depend largely on the completeness with which the whole 

 breadth of the science is cultivated from whichever side it is entered. 



