108 



GEOLOGY. 



Tig. 42. 



brought to the termination of the glacier, together with 

 the stones imbedded in the ice and those accumulated 

 on the surface. Much of the finer matter is carried 

 away by the stream of the glacier, to be deposited here 

 and there, while the more bulky parts are heaped up at 

 the end of the glacier in what is called the terminal mo- 

 raine. As the limit of the glacier varies, as already 

 stated, very much from year to year, these terminal de- 

 posits are scattered in heaps over quite a large space, 

 and are much changed from time to time by the moving 

 ice and water. 



191. Icebergs. In very cold regions the glaciers ex- 

 tend down to the very borders of the sea, and the end 

 of a glacier breaking off into the water, forms an ice- 

 berg. Icebergs are of various sizes, many of them reach- 

 ing a height of 200, some even 300 feet above the sur- 

 face of the water. As, from the specific gravity of ice, 

 only one twelfth of it is above the surface, we see only a 

 small part of an iceberg. For the 300 feet that we see 

 there are 3300 feet (considerably over half a mile) be- 

 neath the surface of the water. A representation of an 

 iceberg seen by Captain Ross is given in Fig. 43. Ice- 



