VI MOUNTAINS 227 
and since their elevation have probably 
always stood, above the range of ice, and 
hence their bold peaks. In Scotland, on 
the contrary, and still more in Norway, the 
sheet of ice which once, as is the case with 
Greenland now, spread over the whole coun- 
try, has shorn off the summits and reduced 
them almost to gigantic bosses; while in 
Wales the same causes, together with the 
resistless action of time—for, as already 
mentioned, the Welsh hills are far older 
than the mountains of Switzerland — has 
ground down the once lofty summits and 
reduced them to mere stumps, such as, if 
the present forces are left to work out their 
results, the Swiss mountains will be thou- 
sands, or rather tens of thousands, of years 
hence. 
The “snow line” in Switzerland is gener- 
ally given as being between 8500 and 9000 
feet. Above this level the snow or névé 
gradually accumulates until it forms “ glac- 
iers,’ solid rivers of ice. which descend more 
or less far down the valleys. No one who 
has not seen a glacier can possibly realise 
