14 
GLACIAL PERIOD. 
glacier of the Rhone even when we have fol¬ 
lowed its ancient boundaries to the shores of 
the Lake of Geneva; for along its northern 
and southern shores we can follow the lateral 
moraines marking the limits of the glacier 
which once occupied that crescent-shaped de¬ 
pression now tilled by the blue waters of the 
lake. 
M. de Charpentier was the first geologist 
who attempted to draw the outlines of the 
glacier of the Rhone during its greatest exten¬ 
sion, when it not only tilled the basin of the 
Lake of Geneva, but stretched across the hilly 
plain to the north, reached the foot of the 
Jura, and even rose to a considerable height 
along the southern slope of that chain of 
mountains. At that time the colossal glacier 
spread at its extremity like a fan, extending 
westward in the direction of Geneva and east¬ 
ward towards Soleure.* The very minute and 
extensive ivestigations of Professor A. Guyot 
upon the erratic boulders of Switzerland have 
not only continued the statements of M. de 
* M. de Charpentier has published a map of this ancient 
glacier in his “ Essay upon the Glaciers and Erratics of the 
Yalley of the Rhone.” 
