THE TWO GREAT SCULPTORS. 
125 
a stream of water. It is very curious to see the num- 
ber of little rills running down the great masses of 
ice at the glacier's mouth, bringing down with them 
gravel, and every now and then a large stone, which 
falls splashing into the stream below. If you look at 
the glacier in the Frontispiece, you will see that these 
stones come from those long lines of stones and boul- 
ders stretching along the sides and centre of the gla- 
cier. It is easy to understand where the stones at the 
side come from; for we have seen that damp and 
frost cause pieces to break off the surface of the rocks, 
and it is natural that these pieces should roll down 
the steep sides of the mountains on to the glacier. 
But the middle row requires some explanation. Look 
to the back of the picture, and you will see that this 
line of stones is made of two side rows, which come 
from the valleys above. Two glaciers, you see, have 
there joined into one, and so made a heap of stones all 
along their line of junction. 
These stones are being continually, though slowly, 
conveyed by the glacier, from all the mountains, along 
its sides, down to the place where it melts. Here it 
lets them fall, and they are gradually piled up till they 
form great walls of stone, which are called moraines. 
Some of the moraines left by the larger glaciers of 
olden time, in the country near Turin, form high hills, 
rising up even to 1 500 feet. 
Therefore, if ice did no more than carry these 
stone blocks, it would alter the face of the country; 
but it does much more than this. As the glacier moves 
along, it often cracks for a considerable way across 
its surface, and this crack widens and widens, until at 
