140 SCENERY OF SWITZERLAND. 
1 50 metres of the houses at Gletsch, where it formed 
a small terminal moraine. From 1822 to 1844 it 
again retreated; then commenced another period of 
advance, and in i855"6o the front was within 
100 metres of the moraine of 1820. From that 
time it has again retreated. 
Shortly above the hotel is the moraine of 1820, 
forming a well-marked curved ridge, whiclr stretches 
across the valley, except where it has been cut 
through by the river. About 100 metres further is 
the moraine of 1855-60, which was the terminal 
moraine of the glacier when I first saw it. Then 
follows a stretch of irregular moraine matter, showing 
in miniature the same irregular heaps, which on a 
large scale we find near the moraines of the ancient 
glaciers. It is interesting to notice the difference 
between the angular rocks which have fallen with 
avalanches from the sides of the valley, and the 
rounded blocks w'hich have been brought by the 
glacier. The larger of these often show a marked 
difference on the two sides, being (Fig. 36, vol.i. p. 148) 
rounded on the side turned to tlie glacier, and 
rugged on the other. Some of the blocks have 
evidently been pushed along by the ice, leaving a 
furrow behind, and making a little mound in front. 
The river leaves the glacier in many streamlets, 
