66 UNIVERSITY OF COLORADO STUDIES 



at the end of the ice shows that an ice-field cannot be a glacier, for 

 certainly a recession of any alpine glacier may temporarily form a 

 lake back of its terminal moraine. The absence of moraine itself 

 may result simply from rapid retreat of a glacier/ In the present 

 instance, Stone' seems to have been himself in doubt as to the pro- 

 priety of applying the term glacier to the Hallett ice, for in 1889, 

 twelve years after his first report, he says: "It is plainly sliding, if 

 not flowing, down the mountain side. It appears so much like a true 

 glacier that I have named it Hallett Glacier, after the discoverer." 

 The italics are mine. 



Chapin's interesting account does not add much that is not noted 

 by Stone. He indicates that the length of the ice was about 1,000 

 feet and its width about a quarter of a mile. He thought the ice- 

 bergs were formed by the ice moving forward and breaking off along 

 the lines of the crevasses, as in case of the large arctic glaciers which 

 extend into the sea. A very different origin of such icebergs is sug- 

 gested elsewhere in the present paper. LeConte,^ in the latest edition 

 of his Elements of Geology, uses a photograph of this ice-field, borrowed 

 from Chapin, to illustrate the unequal weathering of a wind-rippled 

 surface. 



Mills attempted to measure the rate of motion of this ice in 1904, 

 and under date December 20, 1904, wrote: "The glacier was moving 

 in the center and at the northern end at the rate of i . i inches in 24 

 hours." On January 25, following, he added: 



In lining for measurements I used nail-pointed stakes. Considering that the 

 summer of 1904 was cool and snowy, a movement of i . i inch per day for the 

 Hallett is pretty swift. My figures possibly may be slightly wrong, but I believe 



them correct Though I have neither figures nor photographs to verify, 



yet I feel sure that the glacier has become much smaller since I first saw it in 



1895 The bergschrimd (September, 1904) seemed wider than usual, but 



the crevasses w^re completely cemented with recent snow and ice. 



' Lee, Willis, T. "Note on the Glacier of Mount Lyell, California," Journ. Geo!., Vol. XIH, pp. 358, 

 igos. 



' Stone, G. H., "Remarks on the Glaciation of the Rocky Mountains," U.S. Geol. Sun., Hon., Vol. 

 XXXIV, p. 351. 189Q. 



1 LeConte, Joseph, Elements of Geology, 4th ed., D. Appleton & Co., 1901, p. 52- 



