14 THE POPULAR SCIENCE MONTHLY. 



areas of continuous drift. How vast, manifestly, have been the 

 changes which marked the landscape during and since the period 

 of greatest ice ! The period of recession seemingly still con- 

 tinues, but how far the results of this recession will extend can 

 not be told. 



The insignificant development of the ice cap, in its relation to 

 the large glacial streams which radiate off from it, is so striking a 

 peculiarity in some parts of Greenland as to have suggested the 

 suspicion that many of the existing glaciers are merely relics of 

 the great Ice age. Bessels, the accomplished scientist of the Po- 

 laris Expedition, indeed, gives voice to this feeling in explana- 

 tion of the by no means insignificant glaciers of Herbert and 

 Northumberland Islands, lying somewhat north of the seventy- 

 seventh parallel of latitude, which descend from an ice cap of 

 eighteen hundred to two thousand five hundred feet elevation. 

 It did not appear to him probable, or even possible, that the 

 comparatively feeble accumulation of snow which is found at 

 this elevation could originate ice streams of the dimensions 

 which are there found. The facts, however, show that there 

 is no real basis for this interpretation. The snow covering 

 of these islands belongs to themselves, and, feeble though it be, 

 it is quite competent to explain the associated phenomena. Many 

 of the " hanging glaciers "' of Herbert Island, which descend over 

 slopes of some thirty to thirty-five degrees, are so attenuated in 

 their upper parts as to be almost extinguished before reaching 

 the summer ice cap ; yet basally they rapidly increase in dimen- 

 sions, so that before they finally terminate they measure not less 

 than forty to fifty feet in thickness. The slowly accumulating 

 snows descend over the first-formed layers, whether by sliding or 

 otherwise, and help to build up the base while they thin out the 

 top. In all essential respects these hanging glaciers are identical 

 in structure with the larger streams, and it is only in their nar- 

 row connection with the ice cap that they at all difl'er. I am in- 

 deed convinced that some of the minor glaciers have been formed 

 without the assistance of any ice cap or of the accumulated snows 

 of a neve basin ; for such streams, which are seemingly not very 

 numerous, the designation of ravine or couloir glaciers might, 

 l)orhaps, be advantageously used. 



Briefly recapitulated, the glacial phenomena of Greenland are 

 the phenomena of all other glacial regions ; they are not illustra- 

 tive of new forces and involve no explanations that have not 

 already been made familiar through the teachings of other coun- 

 tries. 



