ALPINE SCULPTUEE. 285 



In the Val di Campo, for example, about three-quarters 

 of an hour from Pisciadello, there is a moraine com- 

 posed of large boulders, which interrupt the course of a 

 river and compel the water to fall over them in cascades. 

 They have in great part resisted its action since the 

 retreat of the ancient glacier which formed the moraine. 

 Behind the moraine is a lake-bed, now converted into a 

 level meadow, which rests on a deep layer of mould. 



At Pontresina a very fine and instructive gorge is to 

 be seen. The river from the Morteratsch glacier rushes 

 through a deep and narrow chasm which is spanned at 

 one place by a stone bridge. The rock is not of a charac- 

 ter to preserve smooth polishing ; but the larger features 

 of water-action are perfectly evident from top to bottom. 

 Those features are in part visible from the bridge, but 

 still better from a point a little distance from the 

 bridge in the direction of the upper village of Pont- 

 resina. The hollowing out of the rock by the eddies of 

 the water is here quite manifest. A few minutes' walk 

 upwards brings us to the end of the gorge ; and behind 

 it we have the usual indications of an ancient lake, and 

 terraces of distinct water origin. From this position 

 indeed the genesis of the gorge is clearly revealed. 

 After the retreat of the ancient glacier, a transverse 

 ridge of comparatively resisting material crossed the 

 valley at this place. Over the lowest part of this ridge 

 the river flowed, rushing steeply down to join at the 

 bottom of the slope the stream which issued from the 

 Kosegg glacier. On this incline the water became a 

 powerful eroding agent, and finally cut the channel to. 

 its present depth. 



Geological writers of reputation assume at this 

 place the existence of a fissure, the ' washing out ' of 

 which resulted in the formation of the gorge. Now 

 no examination of the bed of the river ever proved the 



