240 
SCENERY OF SWITZERLAND. 
source of the Inn is in reality merely one of the 
tributaries of the old main river; and there is no Inn 
above the Lake of Sils, the sources of supply having 
been cut off. Nor is it only the main river which 
has disappeared, but several of the former tributary 
streams have been carried away into Italy. 
“If,” says Prof. Heim, to whom and to Prof. 
Bonney our knowledge of these facts is mainly due, 
“we imagine the valley southwards of the Maloja 
filled with cloud, over which we were looking to the 
clear heights above, we should see a series of valleys, 
the Val Marozzo, Val Albigna, so-called from the 
whiteness of the water, Val Muretto, etc., all con- 
verging towards the Inn, of which apparently they 
were undoubtedly tributaries. But the cloud lifts, 
and we see to our surprise that they open on the 
southern side of the watershed, and turn sharply 
down the Val Bregaglia.” 
The slope of the Val Bregaglia being much steeper 
than that of the Inn (Fig. 15 1), the river Maira has 
gradually cut its way back and appropriated more 
and more of the territory which originally belonged 
to the Inn. The waters of the Val Marozzo, now 
called the Upper Maira, and the Val Albigna were 
once tributaries of the original Pipper Inn, but have 
been carried off into Italy by the victorious Maira. 
