MO 
SCENERY OF SWITZERLAND. 
probably enclosed a lake, now represented by the 
Lago di Viverone, Lago di Candia, and some smaller 
pools. It is nearly bisected by the Dora Baltea. In 
fact, it is characteristic of the Italian valleys that the 
surface is comparatively low where the valley de- 
bouches into the plain, and then gradually rises to- 
wards the Po, forming an amphitheatre whose en- 
circling wall is the outer moraine* 
At several places on the south flank of the Alps, 
morainic masses are more or less intercalated with 
younger marine deposits, closely resembling the sub- 
marine moraines of the Polar regions, and the 
Boulder Clay of England and Scotland. 
The older moraines are, moreover, less abrupt, 
and the slopes are more gentle. 
Erratic Blocks. 
The second class of evidence proving the former 
extension of glaciers is that presented by erratic 
blocks, which are often of great size, unrounded, and 
which have come from a great distance. Many of 
these are so remarkable that they have struck the 
imagination of the peasantry, have been attributed 
to superhuman agency, and have received special 
names, such as the “Pierres de Niton” in the lake 
* Penck, Vergletscherung der Deutschen Atyen. 
