J. De Laski—Glacial Action on Mount Katahdin. 29 
Along the “ Horseback” lie boulders so perched upon one 
another that we are sure they were not piled up by any frosts 
to which the mountain has been exposed in modern times; in 
fact, no frost agency could have put them in their present 
position. The ridge is narrow, and drops at an angle not dif- 
fering much from forty-five degrees. We can safely presume 
that snow never accumulates on this ridge to any considera- 
ble depth. This locality is the very focus of winds at all sea- 
sons of the year, and especially during the winter months. 
What snow falls there is probably transformed into ice, and 
would not have much downward movement over the narrow 
ridge as ava:anches. These boulders I consider to have been 
structed with granite boulders, generally angular, and some of 
them from ten to twenty feet square. The great blocks are 
heaped upon each other without order and to such a height 
that it is exceedingly difficult to climb over them. 
I believe the top of Katahdin to have been overridden by 
the glacier, and that the ice-cap has everywhere degraded its 
summit, though, like Hitchcock, I saw nothing of the glacier pol- 
ish and scratches there; nor should we expect to find them 
on so high an eminence composed of coarse granite, where no 
soil can accumulate to protect them from the eroding action 
of winter frosts. Prof. Hitcheock thinks that the northern sides 
of Katahdin at any considerable height have not been stos- 
sed by the drift agent.* I can say with great confidence, that 
the northern side of the mountain just below the “Monument, 
which is three thousand five hundred feet above the Wassatta- 
cook, washing the base of the hill, really “appears like one 
great stoss side,” and is a glacially degraded wall, just as all 
our hills in Maine are, at all heights below that of Katahdin. 
We see boulders with rounded corners lying in place there, 
and wonder why they have not been topp ed down the mount- 
ain by the winter frosts. ; ; 
Furthermore, we have the fact of the disruption of the 
top of Katahdin into “strata,” as Mr. Hitchcock designates 
On the south side of the mountain, just under the 
“Chimney,” this disruption is very marked, apparently hori- 
zontal, though the sheets probably dip toward the south. Now 
* Report of Scientific Survey for 1861, p. 396. 
