THE PROBLEMS OF GEOLOGY 613 



that men of equal ability and attainments had been at work on the 

 problems of geology in the various continents. This supposition is, 

 of course, erroneous, for it is evident that the great constructive work 

 of geology has been done largely by a comparatively few individuals. 

 Indeed, the contrast between nations in the number of creative geolo- 

 gists which they have produced is so great that it is a fair inference 

 that the differences in the principles of the science developed in the 

 three continents under the conditions named would have been more 

 largely due to difference in the capacity of the geologists than to 

 variation in the phenomena demanding explanation. In geology, 

 as in other lines of human endeavor, the exceptional man, the genius, 

 is a factor of paramount importance. 



THE PROBLEMS OF PROVINCES AND DISTRICTS. 



Thus far we have considered only the development of the principles 

 of geology. They are appHcable to the entire earth. There is 

 another great field of geology, which has not yet been suggested — 

 the application of the principles to provinces and districts. 



This second line of problems of geology is illustrated by such 

 subjects as the stratigraphy of a given district, its physiography, its 

 paleontology, etc. The working out of the stratigraphy, or physiog- 

 raphy, of a given county or township may be of great importance to 

 the inhabitants of that county or township, or even of some conse- 

 quence to the nation. They are, however, of much less importance 

 to persons interested in the advancement of the principles of geology, 

 unless their elucidation adds to the science some new principle, or 

 some unusually fine illustration of an old principle. 



The principles of geology may be broadly comprehended by a 

 single individual. No individual can be familiar with more than a 

 minute fraction of the applications of the principles to the numerous 

 geological provinces of the world. Scarcely a score of years ago it 

 was possible for a geologist not only to know the developed principles 

 of the science, but to know somewhat fully the facts upon which those 

 principles were based. At the present time this is impossible. A 

 man may know the more important facts in reference to a few dis- 

 tricts, the broader facts in reference to states, and some of the more 

 general facts in reference to an entire continent, or even more than 



