1873.] 261 [Hunt, 
bushes, which were so thick we could not get through them other- 
wise. It became so fatiguing that we left our blankets and went on 
without them, and spent one night without blanket, coat nor pro- 
visions. 
We found quite a number of very beautiful waterfalls, on a small 
scale, in the main river, and some very fine small falls on some of the 
side cafons. Near the upper part of the cafion we found some of 
the finest and largest cascades I ever saw. In two different places 
the whole river plunges down over the glacier-polished and carved, 
rocky bed, for a distance of nearly half a mile in each place. — 
The main part of the cafion must remain inaccessible to most tour- 
ists, but I think we can, perhaps, make a trail into the upper part, so 
that a visit to these beautiful cascades and the splendid scenery 
around will be possible. 
Ali the upper portion of the Sierra Nevada Mountains is very 
interesting. From the top of Mt. Lyell or Mt. Dana may be seen 
hundreds of different mountain peaks, mantled with snow, with in- 
finite variety of form and finish. The views are too full of sublime 
grandeur to be described. 
Mr. Waterston also spoke of the peculiar rounding of 
blocks of granite by the intense heat of the great fire of 
Nov. 9th. The rounded outline of these blocks recalls the 
dome-like mountains of the Yosemite, and he suggested that 
similar causes produced these phenomena in both cases. 
With regard to Mr. Waterston’s interesting comparison of 
the rounded surfaces resulting from the exfoliation of granite 
blocks by the action of artificial heat to the rounded outlines 
due to concentric lamination, seen in the great granitic 
domes of California, Dr. Sterry Hunt expressed an opinion 
that the cause of the phenomena in both cases was the same. 
When angular blocks of a homogeneous, uncleavable, brittle sub- 
stance, like granite, trap-rock or glass, are exposed to changes of 
heat and cold, the layers of equal temperature established within the 
mass, instead of conforming to the exterior surface, will necessarily 
be curved, and the exfoliation naturally resulting from unequal ex- 
pansion or contraction will give rise to rounded outlines. Prof. 
