RELATIONS TO OTHER SCIENCES 609 



However various may be the demands which exploration may 

 make upon the geographer, yet everywhere one problem is promi- 

 nent which concerns him alone, and that is the earth's surface. The 

 greatest of living German geographers has correctly defined geo- 

 graphy as the science of the earth's surface. * Yet it is not always the 

 earth's surface alone which occupies the most prominent place in 

 geographical investigation. In civilized countries, where the division 

 of labor is far advanced, that problem belongs to the domain of the 

 auxiliary sciences of topography and cartography, while the true 

 geographical problem is the study of the combinations of phe- 

 nomena happening on the earth's surface. 



The consideration of the various phenomena in their areal rela- 

 tions is the characteristic feature of all geographical investigation. 

 Yet it is a great mistake to think that, for this reason, geography 

 is only a method of investigation which may be applied to the most 

 widely different sciences, for it does not treat of the areal rela- 

 tionships of any class of phenomena. Two groups of phenomena 

 are especially prominent in its province. From the earliest times 

 geography has dealt with the relations of the earth's surface to the 

 distribution of man, thereby coming into touch with the science of 

 man, and especially that branch called history. Thus we have come 

 to call this side historical geography, a some\vhat unfortunate des- 

 ignation, since its problems have a broader scope than that usually 

 allotted to history. Its problems constitute an anthropogeography 

 in a much broader sense of that word than the one ascribed to it by 

 its inventor, Friedrich Ratzel. Furthermore, geography early began 

 to study the relations between the earth's surface and mundane 

 phenomena, considering both the organic and the inorganic phe- 

 nomena which take place there. The researches of the biologists have 

 made the largest contributions to our knowledge of the relations 

 between the terrestrial surface and the organic phenomena from the 

 standpoint of the latter, but the strictly geographical side of these 

 problems has yet to be developed. In a similar way, the relation of the 

 earth's surface to the natural forces at work upon it has grown clearer 

 and clearer as the science of physics has advanced. Indeed, in recent 

 years this relationship has acquired unusual complexity, chiefly as 

 the result of English and American studies into the intimate reaction 

 between the forms of the earth's surface and the forces acting upon 

 them. 



Physical geography, the study of the relation of the earth's surface 

 to the earth-forces and to the earth as a whole, is thus seen to occupy 

 a position between the geography of organisms in general, bio- 

 geography in the widest sense of the term, or "ontography," as 



1 Ferdinand Freiherr von Richthofen, Aufgaben und Methoden der heutigen 

 Geographic, Leipzig, 1883, p. 3. 



