GLACIAL PERIOD. 
17 
present basin of the lakes of Brientz and 
Thun. These were joined by the glaciers 
emptying their burden through the valley of 
the Kander. To these combined glaciers the 
formation of the terminal moraine of Thun 
must be ascribed. But before this had been 
formed, the glacier of the Aar, in its amplest 
extension, had also reached the foot of the 
Jura, without, however, spreading so widely as 
the glacier of the Rhone. Farther to the east 
Professor Guyot has traced the boundaries of 
three other colossal glaciers, one of which 
derived its chief supplies from the Alps of Uri, 
bringing with it all the tributaries which the 
main glacier coming down from the St. Gothard 
received right and left, in its course through 
the valley of the Reuss and the basins of the 
lakes of Lucerne and Zug. The second, born 
in the Canton of Glaris, followed mainly the 
present course of the Linth and the basin of 
the Lake of Zurich. Professor Escher von der 
Linth has shown that the lovely city of Zurich 
is built upon a moraine, like Berne. The im¬ 
agination shrinks from the thought that all 
the beautiful scenery of those countries should 
once have been hidden under masses of ice, 
