2 10 
SCENERY OF SWITZERLAND. 
At Gurtnellen we come to Protogine, over which 
the Reuss Hows nearly as far as the Devil’s Bridge. 
At Inschi, a little way above Amsteg, a reef of 
hard Gneiss crosses the valley obliquely. The Reuss 
is still engaged in cutting through this barrier. Its 
upper edge is covered by debris and vegetation, but 
the gorge of the river (Fig. 141) is 200 to 300 feet 
deep with nearly vertical walls. 
It will be evident to anyone that this narrow 
gorge has been cut by the foaming water. Above it 
is the imposing summit of the Bristenstock, with a 
regular slope of over 2000 metres in height, except 
where it is indented by a river terrace, which will 
be again mentioned further on. As we ascend the 
valley we meet other Gneiss ridges, in some places 
* Uher Thai-- u. Seebildung^ 
