184 FRA GMENTS OF SCIENCE. 



of giving direction to the agents which are to be regarded 

 as the real sculptors of the Alps. 



The fracture theory, then, if it regards the elevation of 

 the Alps as due to the operation of a force acting through- 

 out the entire region, is, in my opinion, utterly incom- 

 petent to account for the conformation of the country. If, 

 on the other hand, we are compelled to resort to" local 

 disturbances, the manipulation of the earth's crust neces- 

 sary to obtain the valleys and the mountains will, I 

 imagine, bring the difficulties of the theory into very 

 strong relief. Indeed an examination of the region from 

 many of the more accessible eminences from the Galen- 

 stock, the Grauhaupt, the Pitz Languard, the Monte 

 Confinale or, better still, from Mont Blanc, Monte Rosa, 

 the Jungfrau, the Finsteraarhorn, the Weisshorn, or 

 the Matterhorn, where local peculiarities are toned down, 

 and the operations of the powers which really made this 

 region what it is are alone brought into prominence 

 must, I imagine, convince every physical geologist of 

 the inability of any fracture theory to account for the pres- 

 ent conformation of the Alps. 



A correct model of the mountains, with an nnexag- 

 gerated vertical scale, produces the same effect upon the 

 mind as the prospect from one of the highest peaks. We 

 are apt to be influenced by local phenomena which, 

 though insignificant in view of the general question of 

 Alpine conformation, are, with reference to our customary 

 standards, vast and impressive. In a true model those 

 local peculiarities disappear; for on the scale of a model 

 they are too small to be visible; while the essential facts 

 and forms are presented to the undistracted attention. 



A minute analysis of the phenomena strengthens the 

 conviction which the general aspect of the Alps fixes in the 

 mind. We find, for example, numerous valleys which the 

 most ardent plutonist would not think of ascribing to any 

 other agency than erosion. That such is their genesis and 

 history is as certain as that erosion produced the Chines in 

 the Isle of Wight. From these indubitable cases of erosion 

 commencing, if necessary, with the small ravines which 

 run down the flanks of the ridges, with their little working 

 navigators at their bottoms we can proceed, by almost in- 

 sensible gradations, to the largest valleys of the Alps; and 

 it would perplex the plutonist to fix upon the point at 

 which fracture begins to play a material part. 



