346 J. 0. Smock—Thickness of the Continental Glacier. 
may have been near thirty-five feet per mile, although from 
the fact of the glaciation on the Pocono Highlands considera- 
bly farther south, we should infer that the rise was by no 
means uniform, but was much faster near the glacier front. 
Sam’s Point, the highest part of the Shawangunk range and 
2341 feet high (according to Professor Guyot), which is in the 
same latitude as the Moosic Highlands, is glaciated to the top. 
Walnut Hill or Liberty Hill, in Sullivan County, New Yor 
also exhibits glacial abrasion and drift to within 200 feet of its 
suromit, or at an altitude of 2000 feet. 
During a short visit to the Catskill Mountain region, in the 
summer of 1877, the great height of the western and south- 
western peaks of that mountain group suggested the possibility 
of finding there the upper limit of the ice, and the ascent 0 
unter Mountain was made that season. Visits have beep 
made to this region each year since, and many of the more 
great mass of the continental glacier these valleys were ne 
doubt occupied by detached glaciers. The torrents flowing 
from them evidently modified much of the older drift and de 
posited it in a stratified form in these valley bottoms as we now 
* This Journal, III, vol. xix, pp. 429-451. 
