THE EARLIEST MEN 171 



clocks. Take the case of those glaciers which have 

 been in operation during the Glacial Period, and 

 are still in being. De Mortillet selected these as 

 his " clock," and based his calculations on the 

 length of time which, as he calculated, it would 

 have taken the Rhone glacier to deposit its terminal 

 moraine, namely forty thousand years. But it is 

 quite clear that the Swiss glaciers are compara- 

 tively trifling objects to what they must have 

 been during the Great Ice Age. Dom Izzard* 

 points out that 



" glaciers of the Glacial Period cannot be com- 

 pared to their degenerate descendants now re- 

 maining in the Alps, but rather with the glaciers 

 of Alaska and the Himalayas. In a recent official 

 communication of the geological survey of India, 

 it is attested that in 1903 the glacier of Hassan - 

 abad extended itself in two months a distance of 

 nine thousand six hundred metres. The Rhone 

 glacier during the glacial epoch would be a vast 

 mass of ice similar to this, and if it had advanced 

 towards Lyons at the pace of the Himalayan 

 glacier, it would have covered the distance in 

 thirty years. The Alaskan glaciers do not furnish 

 us with any rapid progress such as this, but they 

 move much more rapidly than the present Alpine 

 glaciers, and in addition the rate of neighbouring 

 glaciers at the same period seems very variable. 

 We cannot, therefore, take the present day Alpine 

 glaciers as standards for movement in the glacial 

 epoch." 



* In a very interesting- and useful paper in Thg Oscotian, 1913. 



