412 



NINETEENTH CENTURY. 



rr, iiT. 



the air is warm enough to melt it, and here it flows gradually 

 away as water, leaving the stones and rubbish it has brought 

 down lying in a confused heap, which is called a moraine. 



Towards the end of the eighteenth century a famous 

 geologist, named De Saussure, spent much time in examining 



Fig. 62. 



Glacier carrying down Stones and Rubbish (Lyell). 



the glaciers of the Alps, and pointed out how they are now 

 forming large deposits in the valleys, out of these heaps of 

 rubbish which they bring down from the mountains. Since 

 his time many geologists had taken up the study, but it was 

 Professor Agassiz who first spelled out the wonderful history 

 we can learn from it, about the former climate of our hemi- 

 sphere. He noticed that rocks over which a glacier has 



