340 J. 0. Smock—Thickness of the Continental Glacier. 
p croeron that report. The course across Staten 
Island and Long Island was given,—as the continuation of the 
New Jersey moraine. Its course in Pennsylvania was traced 
and described by Professor Frederick Prime, Jr., of the Geolog- 
the Wisconsin Academy of Sciences. Professor Chava 
has correlated the eastern and western terminal moraines in an 
article in this Journal for August, 1882. The eastern continu- 
ation of the moraine, on Long Island, was described by Warrel | 
Uphan, lately of the New Hampshire Geological Survey, 10 
ci Journal in 1879.§ The results of the labors of Professor 
wis of the Pennsylvania Geological Survey, in map- 
shoe out “the ae limit of the ice sheet in Pennsylvania, 
have not yet appea 
While engaged in a irate the course of the moraine in New 
Jersey, the questions of the thickness of the ice of the glacier 
and the rise of its upper slope, were suggested by the vary ing 
heliat of its mounds and the absence of drift on the higher 
peaks which stood in its course. The terminal moraine repre 
sents materials pushed forward under the foot of the glacier, 
and also earth and stone carried on its surface and dropped 48 
it melted and retreated northward. The heights of these 
more in giving to it its present contours. It is possible to eS 
minimum estimate for the thickness of the ice from some of th® 
* — Am. Inst. of Mining Engineers, vol. vi, pp. 467-479, Easton, 
Pa. 
+ Ann, ‘Rep. of the pee Geologist for 1877, pp. nhs ator aee 1877. 
oceedings of the Am. Philosophical Society, vo 1. xviii, p. 85. 
. This Journal, Ill, xviii, pp. 81-92, and 197-209. 
