1901.] NATURAL SCIENCES OF PHILADELPHIA, 215 



cave or northeast side has a greater daily motion than last year, 

 while the <;onvex or southwest has not moved at quite so rapid a 

 rate. Whether this change is accidental or is the result of peculiar 

 conditions has not been determined. 



While the plates were left on the surface of the glacier, it is 

 hardly likely that future measurements will be of great value, 

 should the plates be again found. They are approaching a much 

 rougher portion of the glacier, broken by crevasses, deep wells 

 and seracs, and even should they remain on the surface, in many 

 instances it will 'be impossible to see them from the base line. 

 They have, however, served their purpose in demonstrating that the 

 average motion of nearly two feet per day as determined by Dr. 

 W. S. Green in 1888 was either much greater than the actual 

 motion, or was the result of conditions which do not now exist. 



TaUe showing Total Average Daily Motion of Line of Plates on 

 lllecillcicaet Glacier, Glacier House, B. C. 



