68o W. M. DAVIS 



which we ordinarily treat as parts of physical geography and thus 

 associate with present time, are seen really to have their ancient as 

 well as their modern, their geologic as well as their geographic, phases. 

 We can gain some hints as to ancient meteorology, for we find records 

 of paleozoic raindrops, of remote glacial deposits, and we hope yet to 

 find evidence concerning the distribution of early chmatic zones. 

 As far as ancient records of this kind can be pieced together, we may 

 study them in their momentary or geographic, as well as in their 

 continuous or geologic, relations. Concerning ancient phases of 

 terrestrial magnetism we are at a loss; yet our conception of even 

 this branch of earth science, as well as that of the meteorological 

 branch, is certainly broadened when it is regarded as a contemporary 

 of all the geological ages, and not merely as a latter-day characteristic 

 of the globe. 



Similarly, those geological events which we are accustomed to 

 treat in their time sequence, gain fuller meaning when they are 

 decomposed into their momentary elements, and when each element is 

 treated as a geographical feature associated with its contemporary 

 fellows. The columnar sections of stratified rocks, for example, so 

 useful in the understanding of historical geology, are like the edgewise 

 view of a closed book. The book must be opened, the leaves must 

 be turned over one by one, the pages of these early records must be 

 read, like so many gazetteers of ancient times. Never mind if some 

 pages are worn and others are missing; those that can be still deciph- 

 ered assure us that the past was generally hke the present, and warrant 

 the generalization that geology is like nothing so much as a whole 

 series of geographies. 



At the present stage of our progress, the sciences of the earth may 

 be given a somewhat different classification from that of the eight 

 sections into which they are divided for the purposes of this congress. 

 These sections, as it seems to me, represent the subjective divisions 

 of our sciences, within each of which specialists may limit their 

 studies more or less closely, and for each of which speakers may be 

 provided. But when regarded objectively, the divisions, their group- 

 ing, and their relative values, must be otherwise presented. Geol- 

 ogy objectively considered is not merely one of the earth's sciences; 

 it is the whole of them: it is the universal history of the earth. 



