348 J. C. Smock—Thickness of the Continental Glacier. 
2. The outcrops and the surface on these summits and 
higher slopes are made up either of angular, sharp-edged rocks 
in place, or the slightly worn blocks and rock fragments and 
earth of the same nature as the ledges, and apparently derived 
from them. Much of this material seems to have been broken 
off by the action of frost. Had a glacier moved over these 
mountain tops it would have removed this débris, or rounded 
the stones and more prominent ledges. 
3. There is a general absence of drift earth and of stones 
foreign to the rocks in situ. There do not appear to be any 
erratics nor mixed earths. A glacier would have left some for- 
eign materials to mark its course. ; 
4. The phenomena on these higher peaks correspond with 
what are so common and so characteristic of the country lying 
south of the terminal moraine. No glacialist can avoid noting 
this resemblance. If the latter is unglaciated, the former must 
be also. , 
The only explanation left is that there was a limit to the ice 
sheet, above which it did not go. It was not thick enough to 
cover all of these peaks. 
The following table gives the elevations of glacial drift or 
markings. The heights were determined by barometric ob- 
servations, viz: 
On Black: Domes. 2206 i405 2940 feet. 
North Mountain -_.-...- 2500 “ 
Indian Head, or Round Top.---.--- 2800 ‘ 
Overlook Mountain (striz) -_.--..-- 3000 “ 
High Peak (old Round Top)------- 3250 “ 
unter Mountain 2800 “ 
Wittemberg Mountain. _..._-_.._.- 2900 “ 
Puce momen... oo a eee 3080 “ 
Mt. Pisgah (west of Margaretville)..2930 “ 
OTR oo Pe ce ee $306. * 
og, ee ete ern eget 3200 “ 
analogous to the snow coverings of all mountain peaks above 
the snow line. And in some cases they may have amounted 
