NIAGARA. 197 



which the river flowing through the valley once fell as 

 a cataract. Near Pontresina, in the Engadin, there is 

 such a case; a hard gneiss there worn away to form a 

 gorge, through which the river from the Morteratsch 

 glacier rushes. The barrier of the Kirchet above Mey- 

 ringen is also a case in point. Behind it was a lake, de- 

 rived from the glacier of the Aar, and over the barrier 

 the lake poured its excess of water. Here the rock, 

 being limestone, was in part dissolved; but added to 

 this we had the action of the sand and gravel carried 

 along by the water, which, on striking the rock, 

 chipped it away like the particles of the sand-blast. 

 Thus, by solution and mechanical erosion, the great 

 chasm of the Finsteraarschlucht was formed. It is 

 demonstrable that the water which flows at the bottoms 

 of such deep fissures once flowed at the level of their 

 present edges, and tumbled down the lower faces of 

 the barriers. Almost every valley in Switzerland fur- 

 nishes examples of this kind; the untenable hypothesis 

 of earthquakes, once so readily resorted to in account- 

 ing for these gorges, being now for the most part aban- 

 doned. To produce the Canons of Western America, 

 no other cause is needed than the integration of effects 

 individually infinitesimal. 



And now we come to Niagara. Soon after Euro- 

 peans had taken possession of the country, the con- 

 viction appears to have arisen that the deep channel of 

 the river Niagara below the falls had been excavated 

 by the cataract. In Mr. Bakewell's * Introduction to 

 Geology,' the prevalence of this belief has been referred 

 to. It is expressed thus by Professor Joseph Henry in 

 the ' Transactions of the Albany Institute:'* * In view- 

 ing the position of the falls, and the features of the 

 country round, it is impossible not to be impressed with 

 * Quoted by Bakewell. 



