36 GLACIERS 



lovers of the Swiss mountain valleys over the shrinking 

 of the Mer de Glace of Chamonix, the Aar Glacier of 

 Rosenlaui, and the Rhone Glacier. But they will extend 

 again some day. The Yengutsa Glacier in the Himalayas 

 has increased two miles in length since 1892. Another 

 Himalayan glacier (that of Hassanabad) had slowly shrunk 

 back during a long period until seven years ago it was six 

 miles shorter than it had been fifty years before ; then 

 suddenly it advanced over the lost ground and actually 

 grew six miles — pushed its snout forward six miles, back 

 to its old position — in three months ! 



The great extension at a remote prehistoric period of 

 the Swiss glaciers, and the general existence in past ages 

 of glaciers and an ice-covering of the land in Central and 

 Northern Europe, are proved by the following four pieces 

 of evidence : First, the existence of " moraines," those 

 huge embankment-like piles of broken rocks, many even 

 hundreds of miles distant from the existing glaciers, often 

 in positions which it is clear from the' "lie of the land" 

 the present glaciers would have reached if they had been 

 enormously increased in size ; second, the existence of 

 detached rocks, called " erratic blocks," which are found 

 perched on the surface of the ground at a vast distance 

 from the mountains from which their mineral Structure 

 shows them to have been carried ; third, the occurrence of 

 rock surfaces far from existing glaciers, which nevertheless 

 show the peculiar polishing and scratching which is made 

 only by glaciers ; fourth, the existence in more southern 

 regions of the remains of plants and animals of kinds 

 belonging to a cold climate, and now only found in the 

 far north, as well as the existence of Alpine plants in 

 regions now separated from the cold upper parts of Swit- 

 zerland (where they flourish) by vast expanses of warm 

 country, over which they could not spread in the present 

 condition of the climate. 



