10 
GLACIAL PERIOD. 
from the ice, to the very shores of the Lake of 
Geneva, where, near the mouth of the river, 
on both banks of the valley, the ancient mo¬ 
raines may be traced to this day, thousands of 
feet above the level of the water, marking the 
course the glacier once followed. 
It is evident that here the remains of the 
glacier mark a process of retrogression; for 
had these successive walls of loose materials 
been deposited in consequence of the advance 
of the glacier, they would have been pushed 
together in one heap at its lower end. That 
such would have been the case is not mere 
inference, but has been determined by direct 
observation in other localities. We know, for 
instance, by historical record (see Gruner’s 
u Natural History of the Glaciers of Switzer¬ 
land”), that in the seventeenth century a 
number of successive moraines existed at 
Grindelwald, which have since been driven 
together by the advance of the glacier, and 
now form but one. Indeed; we have ample 
traditional evidence of the oscillations of gla¬ 
cier-boundaries in recent times. When I was 
engaged in the investigation of this subject, I 
sought out all the chronicles kept in old con- 
