SNOW AND ICE. 
127 
at a very short distance we come to a bank ot loose 
sand and stones, some angular, some rounded, which 
curves across the valley, except where it has been 
washed away by the river. This is the moraine of 
1820, and shows the line at which the glacier stood 
for some years. The Swiss glaciers generally in- 
creased till about 1820, then diminished till about 
1830, increasing again till about i860, since which 
they have retreated considerably. The moraine of 
1856, in the case of the Rhone glacier, forms a 
well-marked ridge some distance within that of 
1820. 
From that ridge to the foot of the glacier, the 
valley is occupied by sand and stones in irregular 
heaps, some of them smoothed and ground by the 
glacier. This is especially the case with the larger 
stones, which show a marked difference on their two 
sides, that turned towards the glacier being smooth, 
while the lee side is rough and abrupt. Many of 
the stones were evidently pushed by the glacier along 
the valley, and have left a furrow behind them. The 
Rhone wanders more or less over the flat bottom of 
the valley, and spreads out the material which has 
been brought down by the glacier. 
Here and there on the glacial deposits lie blocks 
with fresh angles, totally different in appearance from 
