io6 



GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 



TEMPERATURES OF STREAM FROM ASULKAN RIDGE. 



8. FRONTAL CHANGES. 



Points of reference for the study of the frontal behavior of the lower Asulkan 

 nose were established August 12, 1899, by the Messrs. Vaux and observations 

 and photographs have been repeatedly made by them since. At that time they 

 made an unsuccessful search for reference blocks previously marked by H. W. 

 Topham. One year previously (August 23, 1898) they had visited the glacier 

 and obtained a photograph from their "test rock," which was published, along 

 with a brief description of the glacier, in the paper previously referred to. 1 

 A comparison of their test picture of 1898 (plate XLI, figure 2) with that of 

 1899 showed a slight shrinkage in the height and a slight increase in the breadth, 

 "while the position of the tongue had not changed to an appreciable extent." 

 The ice fall appeared to be less and they note that the ne"v line was lower, the 

 glaciers upon the slopes of Castor and Pollux more active, giving rise to a 

 number of avalanches, which seemed very infrequent in 1898. In marking the 

 position of the tongue at the time of their visit in 1899 three rocks were selected 

 in a line with the nose, the magnetic bearing of which was N. 8535' E. One 

 rock was located upon the small, left lateral moraine, a second just below and to 

 the right of the nose, while the third lay upon the inner side of the higher 

 right lateral. In 1900 the Messrs. Vaux observed a retreat of 24 feet and " a 

 marked shrinkage in every dimension." From 1900 to 1901 these observers re- 

 ported an advance of 4 feet and for the two years 1901 to 1903 an additional 

 advance of 36 feet. 2 



This glacier was first visited by the writer September 17, 1903, at which time 

 it was found that the nose of the glacier lay 13^ feet beyond the Vaux line, 

 which was readily located by the two well marked end rocks. This would indicate 

 that the nose had retreated z\ feet between the date of Vaux's measurement in 

 1903 and September 17 of the same year. The stone that had been marked 

 near the nose had been pushed forward some 14 to 15 feet, turned on end and was 

 about to topple over. Upon August 27, 1904, the nose lay 12^ feet beyond the 

 line, indicating practically no change, when allowance is made for difference in 



""Some Observations on the Illecellewaet and Asulkan Glaciers of British Columbia," Proceedings oj 

 the Acad. of Sci. of Phil, 1899, p. xai. 



a " Variations of Glaciers," H. F. Reid, Jour, of GeoL, vol. xni, 1905, p. 316. 



