8 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
The largest perched-block now being carried along by this glacier 
measures 34 by 28 by 10 feet, and is supported on & column of ice 
five or six feet thick, eight feet high on its northern side, and six 
feet high on its southern. Many masses of rock larger than the 
one measured were seen in the terminal moraine that circles about 
the foot of the glacier. ; 
The motion of these glaciers was not observed, but that it exists 
is manifest from the nature of the crevasses and the curvature of 
the dirt-bands. The rate of flow of a glacier on Mt. McClure was 
measured several years since by Mr. Muir, who found it to be 47 
inches in 46 days (from August 21st tc October 6th, 1872).* 
Six glaciers are known to the writer within the southern rim of 
the hydrographic basin of Mono Lake, and about twice this num- 
ber were seen about Mt. Conness, Mt. McClure, Mt. Lyell, Mt. 
Ritter, and the Minarets. 
Many of the glaciers mentioned above have been previously re- 
ported in popular articles by Mr. John Muir, but the fact that they 
are true glaciers haying been denied by eminent geologists, it is de- 
sirable to have a more accurate description of them. 
[The communication was illustrated by photographic lantern 
views. Its subject-matter will be more fully presented in the Fifth 
Annual Report of the United States Geological Survey. ] 
Mr. Girpert THompson described certain glaciers on Mount 
Shasta believed to be new to science. Their discovery increases 
the number of known glaciers on the flanks of Shasta to seven. 
Mr. Houmes described modern glaciers of the Rocky Mountains 
observed by himself. Those of the Wind River Mountains are 
from one-fourth mile to one mile in length. He illustrated by a 
sketch the position of three small glaciers in the gorges of Mount 
Moran, in the Teton Range, at an altitude of 10,000 feet. 
Mr. PowEtu remarked that the chief interest of these small 
modern glaciers lies in the fact that they illustrate the process by 
which the drift has been distributed, and aid in completing the 
theory of the ancient glaciation of the country. 
Mr. Marx B. Kerr mentioned the occurrence of a probable 
glacier in the Salmon Mountains, a division of the Coast Range. 
e 
* American Journal of Science, Vol. V, p. 69; 1878. 
