574 



PROCEEDINGS OF THE ACADEMY OF 



[Dec, 



of this area with that similarly plotted in 1899 shows a marked shrink- 

 age in the surface of the ice at that point. 



Table Comparing Summer Daily Motion of Plates on Illecillewaet 

 Glacier. 1899-1906. 



AsuLKAN Glacier. 

 Glacier House, British Columbia. 



This glacier, lying at the head of the Asulkan Valley, some three miles 

 from Glacier House in British Columbia, has been observed with more 

 or less regularity since 1899 (compare Proc. Acad. Nat. Sci. Phila., 

 1899, p. 504). At that time rocks were marked and the general aspect 

 of the tongue and moraines noted. Photographs have also been made 

 which show the yearly changes in extension, thickness and breadth. 



The work on this glacier in 1906 covered practically the same 

 ground as on the Illecillewaet, and may be similarly divided. 



Test Pictures. — An almost continuous record of photographs of the 

 lower section has been made since 1899 from a large flat rock several 

 hundred feet below the glacier which affords a view of all parts. A 

 comparison of these photographs taken over a series of years shows 

 smaller changes than in the cases of some of the neighboring glaciers, 

 but that they are of the same character — a general shrinkage and 

 reduction of section area (compare Plates XXV and XXVI with Plate 

 VI, Proc. Acad. Nat. Sci. Phila., 1899). 



