334 CLIMATIC COXDITIOXS OF THE GLACIAL EPOCH. 



It being evident that the ice masses of Southern Europe are diminishing 

 in size, the question naturally arises -whether this is also the case in the other 

 great glacier regions of the world, especially in the Himalayan and the 

 Scandinavian ranges. Here, however, we meet with a difficulty. These 

 distant and rarely visited regions iiave had their glacial features explored 

 with so much less detail than have the Alps, the Pyrenees, and the Caucasus, 

 that it is hardly to be expected that mucli trustworthy information should 

 be forthcoming concerning the changes of the last few years. It is only in 

 the case of mountain ranges which have been accurately surveyed that the 

 means are fiu-nished for accurate comparison from time to time of the 

 changes which may have taken place in the amount of surface covered by 

 snow and ice. That there has been some diminution of the glaciers both of 

 the Himalayan and Scandinavian ranges seems evident ; but it is not easy to 

 say, from any evidence as yet furnished, how much of this has been accom- 

 plished within the present century, and how much belongs to that indefinite 

 past which to most geological writers is represented by the term " Glacial 

 epoch." More will be said in regard to this point in the next chapter. In 

 the mean time it may simply be added that Professor Dufour thinks he 

 has evidence sufficient to justify him in stating that all the glaciers of the 

 northern hemisphere are participating in the same retrograde movement. 

 This evidence, as presented in the article to which reference has already 

 been made, is, however, extremely vague and unsatisfactory.* 



Although the subject is not one intimately' connected with the purpose of 

 the present chapter, yet as it throws light on the causes of the motion of 

 glaciers, a few words will here be added in reference to those very irregular 

 ice masses which from time to time move forward with great rapidity, and 

 do great damage by devastating the regions below, either directly, by flood- 

 ing the country and covering it with detritus, or, indirectly, by causing the 

 formation of a temporary lake, Avhich finalh' breaks away and sends a flood 

 of water down the valle3^ 



Of this latter class is the Tyrolese glacier called the Vernagt, which from 

 time to time pushes forward with extreme rapidity, combining with another 



* For instance for the. statement that the recession of the Scandinavian glaciers "has now become general," 

 no other authority is given than that of "a Swede, JI. Nystroni, who was kiml enongh to obtain the information 

 asked for." For Greenland it is said that "several people had observed that the glaciers of that country had 

 retreated considerably." Nordenskjold is reported, also, as having stated that the glaciers of Spitzbergen " had 

 undergone a similar diminution within the past few years." This is in flat contradiction with what this author 

 has himself published since his return from his exploration of that region. (See pp. .335, 336.) 



