MAN'S DEPENDENCE ON THE EARTH. 103 



Frencliman is not less than that from the rude marble block to the 

 statue which the genius of an artist designs from it. So, while the 

 earth has evolved slowly, man has developed with a feverish activity. 

 With time he has contracted new needs and tastes, which have caused 

 him to appreciate and seek out what he had despised ; and, collected 

 in groups, with gathered knowledge, men have acquired powerful 

 forces which have enabled them finally to surmount obstacles that 

 had at first stopped them. It could not be otherwise than that the 

 value of the relation between the earth and man should have been 

 frequently and materially modified. 



Every one of the four factors of which we have determined the 

 essential importance has undergone great variations in the course 

 of man's evolution. Consider the relief. Hills and small moun- 

 tains appear to have been the first places inhabited by man. It was 

 in the foothills of the Pyrenees and the Alps, in the moderately 

 elevated limestone plateaus of the central massif, and the modest 

 heights of Charolais and Picardy, that were found the traces of the 

 most ancient human occupation in France. It is reasonable that it 

 should be so. The nascent brook, the living spring, the slightly 

 undulating slope, are mollified natural forms with which the in- 

 dividual man can enter into immediate relation without exerting too 

 great effort. 



The plain, or rather the wet plain, offers only much later ves- 

 tiges than the hills. Some may say it is because it has been dug 

 over so often; but it is probable that life became possible in 

 such situations only after some development of civilization. Re- 

 gions subject to overflow and excess of stagnant water present 

 obstacles to cultivation and comfortable living which it was beyond 

 the power of primitive man to overcome, and would repel habitation 

 for a long time. But once made habitable, the plain, with its mel- 

 low, fertile soil and its rivers offering easy ways of communication, 

 would become attractive and draw population down from the hills, 

 the chief value of which would henceforth lie in their adaptability 

 to purposes of defense against attack. 



Only the high mountain still remains unsubdued; but daily 

 progress is made toward mastering it. Terrible in aspect, and seem- 

 ingly beyond man's reach a hundred years ago, it is now the resort of 

 tourists, and is climbed, traversed, and tunneled or threatened by 

 railroads. It is not yet subdued, but it no longer stops us. 



Thus each form of relief is more or less adapted to some of the 

 many human wants. Each has its special value, changing from one 

 epoch of civilization to another. The hill, an obstacle to the agri- 

 culturist and the merchant, has become auxiliary to the manufac- 

 turer through the motor force which is derived from its streams. 



