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CHAPTER XIV. 



RETROSPECT, WITH NOTICES OF EARLY PALAEOZOIC STRATA, 



GRADUAL changes taking place in the crust of our earth are 

 admirably illustrated in the Swiss Alps. Whether the traveller 

 crosses the Alpine chain by the Julier and the Bernina, by the 

 Splugen or the St. Bernard, by the St. Gothard or by the 

 mountains of Berne or the Valais, he will everywhere find 

 enormous masses of fallen rocks and debris, which here and 

 there cover the slopes and bottoms of the valleys, and afford 

 evidence of the constant weathering of mountains and of the 

 impossibility of vegetation advancing so rapidly as to cover all 

 the rocky fragments with its green mantle. 



Deep ravines have in various places been formed by the action 

 of running water ; and torrents forcing their way through these 

 gorges have carried down heaps of stones and earth into the 

 valleys, and have thus occasioned the formation of tall cones. 

 By the continual process of lowering heights and filling up 

 valleys, lofty peaks gradually diminish in elevation, and lake- 

 basins are filled up. Thus the northern part of the Lake of 

 Wallenstadt will in turn be converted into dry land. Already, 

 within the last fifty years, since the river Linth was conducted 

 into the lake, a considerable delta has been formed, which is 

 continually increasing, and now fills the north-western portion 

 of the lake, so that the mouth of the river Linth is constantly 

 advancing into the former lake-basin, and the bed of the river 

 has to be constantly elongated and deepened. 



At present, as the Swiss mountains become disintegrated, all 

 the masses of rock remain in the vicinity where they fall ; but 

 in the drift-epoch the broken pieces were carried away to great 

 distances, covering the soil of the plain of Switzerland, and in 

 some parts raising it considerably. If we imagine all these 



