42 
SCENERY OF SWITZERLAND. 
of the Limmat from Rapperschwy], on the Lake of 
Zurich, to near Baden. 
Besides the actual moraines and the erratic 
blocks, the glaciers as they retreated, and the floods 
arising from the melting of the ice, left great masses 
of so-called “Diluvial” gravels, which occupy much 
of the valley bottoms, not having even yet been com- 
pletely re-excavated by the rivers, and as we ap- 
proach the Jura even form the hills, the valleys being 
occupied by comparatively recent river deposits. 
Thus the river Lorze runs on this gravel from the 
Lake of Zug as far as Baar: at Lucerne the gravel 
has been pierced to a depth of 30 metres without 
reaching the bottom; in several places it attains a 
thickness of even 60 metres.* The river Langeten 
near Roggwyl sinks almost entirely into the gravel, 
so that it disappears except in very wet weather,’ 
rising again in several strong springs a little further 
down the valley. The surface of the gravel beds is 
very irregular, and often gives rise to small lakes, as 
for instance the Maiiensee, Bibersee, Finster See, 
Rothsee, etc. Several of the present peat mosses 
were formerly shallow lakes of this character. The 
Baldegger See and Hallwyler See are separated from 
* Kaufmann, Beitr. z. Gcol. K. d. Schzc., L. xi. 
