1906,] NATURAL SCIENCES OF PHILADELPHIA. 579 



the case on the right side where the main stream debouches from a 

 most beautiful ice arch. 



Horseshoe Glacier. 



Paradise Valley, Laggan, Alberta. 



Although no marks have been placed on this glacier it offers some 

 striking and unique points of interest. It is of the piedmont type and 

 owes its existence to the snow avalanches from Mounts Hungabee, 

 Ringrose, Lefroy and Mitre, to the north of which it lies. The tongue 

 and lower portions are deeply buried in moraine. While in common 

 with others there are indications of shrinkage and retreat, the protection 

 of moraine on the surfaces renders these changes very slow. An ex- 

 ceedingly interesting phenomenon was noticed at a point several 

 hundred feet above the tongue where a great sinuous canon has been 

 worn in the ice. The sides were perpendicular or overhanging, from 

 20 to 30 feet in depth, while the curves were 1,000 to 1,500 feet long. 

 In all there were not less than ten great bends, and through the bottom 

 a good-sized stream flowed. The walls exhibited very fine examples of 

 banding, while all the surfaces were fluted horizontally, apparently due 

 to the greater melting in summer than in winter. Should this be correct 

 the caiion has been at least twelve years in forming. 



From the foregoing data it is hard to draw more than the most 

 general conclusions. It may, however, be safely noted that in all the 

 glaciers observed there has been decided shrinkage and recession in the 

 past seven years. While changes in the position of the tongue may 

 have been small, the ice mass and sectional area are evidently much less. 

 On the other hand the average yearly recession was in 1906 less than 

 during a similar period five years before, the exception in the lUecille- 

 waet Glacier being probably due to unusual conditions. The trifling 

 advances in the Asulkan Glacier may be attributed to local causes and 

 have no particular significance, but the increased daily rate of flow of 

 the IlleciUewaet, coupled with a thickening of the ice at the sky line as 

 seen from the test rock, would seem to point to a period of greater 

 activity in the not very distant future. 



