Glaciation of Mountains, Etc. — Uphdui. 173 
of moderate size. On the southwest slide a few masses were 
seen as heavy as a lumdred pounds each, but in general — al- 
ways upon the east slide — the pieces ran from a few ounces 
up to twenty pounds in weight. They were chielly fragments 
of slates and sandstones, identical with the strata of the coun- 
try north and west, mingled with pieces of mctamorphic and 
trappean rocks. . . . Among the scanty drift upon tlie upper 
third of the southwest slide, I have never seen a fossil-bearing 
stone. And upon those parts of the summits where drift was 
found, only once was a fossil met with, — a solitary brachiopod 
impression on a ten-pound piece of sandstone, picked up on 
the slope northward from West peak to the Saddle, about 600 
feet below the top of the peak, or at an elevation of about 4,615 
feet above the sea. This is by far the highest point at which 
fopsiliferous rocks have yet been found upon Ktaadn." 
From these observations it is known tliat the northern sum- 
mits of this mountain were ice-covered, the upper limit of the 
drift being apparently about 4,700 feet above the sea ; but the 
higher west and east peaks, the sharp serrated ridge, the 
Chimney and Pamela, rising above that bight, appear to be 
destitute of drift, and probably formed an island projecting 
out of the continental mer de glace during the epoch of maxi- 
mum glaciation. If we compare the slope of the surface of 
the ice-sheet with the present sea-level, disregarding the oscil- 
lations of the earth's crust which carried the land to a great 
elevation, as I believe, before the formation of the ice-sheet, 
depressed it while thus loaded, and partially uplifted it again 
after the ice was melted away, the average ascent from the 
glacial border in the Atlantic to Katahdin was about nineteen 
feet per mile. But if the glacial border was indented within 
the gulf of Maine, the slope would be greater, perhaps twenty- 
five feet or more per mile. The greatest thickness attained by 
the ice upon the country surrounding the base of Katahdin 
was about 4,0(.X) feet, or foiir-fifths of a mile. In other parts 
of Maine the directions of the glacial current, as shown by 
striae and transported boulders, were prevailingly S. S. E., 
with local deflections which bear rarely to the west of south, 
and more frequently to the southeast or almost due east. 
Examples of the courses of stria\ from a long list reported by 
C. H. Hitchcock.' are in Fryeburg and Alfred. S. 32° E. ; in 
H4oolopv of Now Hampshire, 1878, vol. nr. These and other btar- 
iugs noted in this paper ure referred to the astronomic meridian. 
