98 W. M. DAVIS RELATION OF GEOGRAPHY TO GEOLOGY 



reference to rock structures and to past processes. But it may be fairly 

 urged in relation to all these examples that the science to which a descrip- 

 tion belongs can not be determined by the devices that it employs, nor by 

 the simplicity or the detail of the statements that it contains, but by the 

 object in view and by the pertinence of such matters as are stated to the 

 accomplishment of that object. Let me illustrate this principle by 

 analogy. 



A^Tien a chemist weighs a precipitate, does his work belong under 

 physics because he for the moment gives up questions of composition and 

 concerns himself with the action of forces ? Does the work of a physiolo- 

 gist belong under chemistry because he for a time studies the composition 

 of the digestive fluids of the human body? Does the work of a petrog- 

 rapher fall under chemistry when he uses chemical reagents in the analy- 

 sis of his rocks, or under physics when he uses N"ichols prisms and polar- 

 ized light in the determination of his minerals ? When a man calculates 

 the orbit of a comet from three observations of its position in the heavens, 

 is his work to be classed under mathematics or under astronomy? 



The principle which must guide us in assigning a place to all such 

 work is that it must be classed according to the object to which it is 

 directed, not according to the means by which it is carried on, nor accord- 

 ing to the detail with which it is elaborated. In the last case mentioned 

 if the object sought is a fuller knowledge of a comet, the work belongs 

 under astronomy, even though the means used in order to reach the object 

 are mathematical. In all such questions it is the object and not the 

 method's, the end and not the means, which determines the classification of 

 the work done and of the man who does it. Utter confusion would result 

 from any other plan of classification. Hence there is good and sufficient 

 reason for saying that the description of the Front Eange given below, 

 and all the other descriptions and phrases that I have here introduced, 

 are geographical descriptions and phrases, because their object has been 

 the presentation of the facts regarding existing land forms, even if in 

 gaining this object various facts regarding rock structures and past 

 processes were freely employed whenever they were helpful. All of the 

 descriptions here cited were carefully phrased in such a way as to lead up 

 to existing facts. Emphasis was always intentionally placed on existing 

 features and not on past conditions or processes, except in so far as these 

 directly aid in appreciating present conditions. All geological matters 

 which have no bearing on existing facts were excluded. N'o mention was 

 made of geological periods in terms of their names, nor v/as any account 

 given of the succession of events in past time, except in so far as such 

 succession may throw light on the nature of the facts now visible. 



