352 



SCIENCE. 



[N. S. Vol. XXIII. No. 583. 



and warm and much melting over and about 

 the glaciers has occurred. Snow has been 

 removed from portions ordinarily covered 

 throughout the year, exposing numerous cre- 

 vasses and concentrating relatively large quan- 

 tities of foreign material upon the surface of 

 the ice. The dirt zones, dirt bands, stratifica- 

 tion and all the phenomena based upon the 

 differential melting of the ice have stood forth 

 with unusual clearness, so that the season has 

 been an exceptionally favorable one for glacial 

 study. A reexamination was made of the five 

 glaciers upon which a preliminary report was 

 published in May, 1905.' 



I. Victoria Glacier. — Located at the head 

 of the Lake Louise Valley, this glacier is nour- 

 ished by the snow which falls between Mount 

 Lefroy and Mount Huber, the snow and ice 

 which are avalanched from these mountains 

 and Victoria and that supplied by the double 

 tributary. The avalanches during the spring 

 and summer have been exceptionally numer- 

 ous and heavy from the hanging glaciers, par- 

 tially making up for the loss occasioned by 

 the unusual warmth of the summer and the 

 diminished precipitation of the past winter. 

 Along the oblique front the retreat has been 

 much greater for the year than for any other 

 since observations began in 1898. From Sep- 

 tember 13, 1904, to September 2, 1905, this 

 amounted to 20.35 feet, the average retreat for 

 the last six years being, at this point, 14.5 

 feet. Some 300 feet farther down the valley 

 the retreat between the above dates amounted 

 to 13.2 feet. 



The real nose of the Victoria glacier is 

 completely veneered with rock debris, so that 

 the ice is not visible and is effectually pro- 

 tected from melting. The last episode here 

 was one of advance, the glacier having in- 

 vaded the forest and mounted an ancient 

 moraine. From July 9 to September 13, 

 1904, a small stream of clear, ice-cold water 

 was observed to flow from this part of the 

 glacier and stones embedded in the front had 

 settled back an inch. During the year this 

 very small amount of recession has been made 

 up, the points selected upon the boulders lack- 



' Smithsonian Miscellaneous Collections, Quar- 

 terly Issue, Vol. 47, Pt. 4, pp. 453-496. 



ing but .03 to .06 of a foot of regaining the 

 position occupied when the stations were es- 

 tablished, and the nose has been practically 

 stationary. 



July 9, 1904, a line of 18 steel plates was- 

 set across the Victoria glacier, approximately 

 100 feet apart and 3,600 feet back from the 

 nose. Although the glacier is here straight, 

 the maximum movement was found to be two 

 thirds of the way across, at plate No. 13, and 

 averaged for 20 days (July 9 to July 29) 2.Y4 

 inches daily. In remeasuring the distances 

 moved by the series of plates (July 29, 1904, 

 to September 5, 1905) it was found that plate 

 No. 11 had made the greatest advance, Y1.8 

 feet, giving a daily average of 2.14 inches, 

 or 80 per cent, of its midsummer motion. 

 Forbes's dirt-bands were located in 1904 from 

 the surface of the glacier itself and their dis- 

 tances approximately determined. This sea- 

 son it was found that their upper margins 

 were sharply defined, when seen fi-om a dis- 

 tance of two thirds of a mile, or more, and 

 with the help of an assistant these margins 

 were marked by means of small cairns and 

 their distances afterward measured with a 

 steel tape. From the base of the ice slope 

 upon which they are formed some 19 bands 

 were thus located, their distances apart, ex- 

 pressed in feet, running as follows : 159, 174, 

 126, 124, 113, 109, 100, 83, 75, 100, 86, 88, 57, 

 81, 66, 83, 83 and 45. These bands, which are 

 transverse to the glacier at the time of their 

 formation and but slightly curved, become 

 more and more convex down stream and indi- 

 cate by their shape the locus of maximum 

 surface motion, and there is reason for think- 

 ing the approximate annual motion of the ice. 



IL Wenkchemna Glacier. — As reported pre- 

 viously, this is a piedmont type of glacier, near 

 the head of the Valley of Ten Peaks, made 

 up of some twelve component streams, placed 

 side by side. It lies close in upon the north- 

 ern side of the great Wenkchemna series of 

 peaks, which form here the Continental 

 Divide. These peaks supply the snow, protect 

 the meager neve field from the noonday sun 

 and contribute quantities of rock debris with 

 which the glacier is almost completely covered. 

 In August, 1904, a series of eight stations was 



