1887] Notes on the Glaciation of the Pacific Coast. 255 
topography, is of a most explicit and interesting character. The 
Muir Glacier, which is two miles wide at its mouth, is formed by 
the confluence of nine main streams, coming in majestic curves 
from the southeast, east, north, northwest, and west, and uniting 
in a vast amphitheatre of ice many miles in diameter a short 
distance above its present outlet. From the surface of this icy 
amphitheatre numerous islands project, as from the waters of an 
archipelago. The summits of these bear every mark of having 
been freshly uncovered by the decreasing volume of ice. Below 
the mouth of the glacier numerous islands in the bay present 
exactly the same appearance, except that they now project from 
water instead of ice. Their recent glaciation is indicated by every 
characteristic sign. Willoughby Island, about the middle of the 
bay, is as much as a thousand feet above the water. Were the 
ice to retreat a few miles farther, it would doubtless uncover an 
extension of the bay with numerous islands similar to those now 
dotting its surface south of the glacier. Fresh glacial débris 
lingers on the flanks of the mountains on either side of the inlet 
. ata height of two thousand feet; and at three thousand seven 
hundred feet striae were observed moving, not down the moun- 
tain, but parallel with the axis of the bay, showing that the 
present glacier is but the remnant of an ice-flow of similar 
character and direction of movement, but of vastly greater 
dimensions, extending and filling the whole bay to its mouth in 
Cross Sound, a distance of twenty-five miles. At Sitka the rocks 
in the harbor are all freshly striated, the direction of the move- 
ment being in a westerly direction, or towards the open sea. 
Glaciers still linger in the mountains at the head of the bay to 
the east of Sitka. : 
From all these facts it seems evident that we have only to 
suppose a slight increase of present forces favorable to the pro- 
duction of glaciers to find a state of things which will account 
for all the facts and unravel the whole intricate web of phenomena 
upon the western coast of North America. 
_ The present formation of glaciers on the coast of Southeastern 
Alaska is favored not so much by the coolness of the climate as 
by the elevation of the mountains and the excessive amount of 
precipitation, which is not far from one hundred inches annually. 
There is no evidence that the elevation of the coast has materially 
changed in recent times. Nor is there evidence of any changes 
