GLACIATION OF THE HIGH MOUNTAINS 435 



in glacial geology is that of the passage of an ice-sheet over a highland 

 barrier of such extent and elevation as that of New England ; yet proof 

 of this passage seemed complete. Evidence from the Adirondacks and 

 from the Green mountains * shows that the ice-sheet rose well up toward 

 the top of these mountains, if in fact it did not override the highest 

 peaks. In the White mountains, the highest of all in this mountain- 

 barrier region, Hitchcock f has found transported pebbles at the height 

 of 6,100 feet. On mount Ktaadn transported fragments have been 

 found by different observers at various elevations, although Hamlin, X 

 who found them at the highest point, did not discover any above an 

 elevation of 4,615 feet. Indeed Upham, from his study of the litera- 

 ture, § announces that Ktaadn projected its peak above the mer de glace. 



To this evidence of previous w r orkers I am able to add one or two far- 

 ther observations concerning the glaciation of the higli mountain tops 

 of New England. About midway between Ktaadn and mount Washing- 

 ton, in the Dead River plantation, is a mountain called mount Abraham, 

 which reaches an elevation of about 4,000 feet. From its crest mount 

 Washington may be seen to the southwest and mount Ktaadn to the 

 northeast. This peak rises distinctly higher than any of the surround- 

 ing mountains, and in fact is one of the highest in Maine. On its crest 

 are found not only numerous small fragments of transported rock, but 

 even large boulders. One particularly large foreign erratic, several tons 

 in weight, may be seen along the trail ; and on the very crest, near the 

 cairn, I picked up several distinctly foreign pebbles of a stratified rock, 

 entirely different from the gneissic and schistose layers of the mountain 

 itself. 



While ascents of other lower mountains were made, and in each case 

 transported fragments found, one does not need to climb to the crests of 

 these lower peaks in order to obtain evidence that they were overridden 

 by an ice-sheet moving from the north. Their form proves this conclu- 

 sively, for the stoss side is strikingly smooth and rounded, while the lee 

 side is prevailingly steep, and at times very precipitous. This is so 

 prominent that it attracted the attention of Thoreau during his journeys 

 through the Maine woods. Further reference is made to this feature of 

 the mountains in a latter part of this paper. 



During the first ascent of mount Ktaadn the highest peak was not 

 reached. While the ascent of the high North peak was being made the 

 clouds closed in around the still higher South peak; but on this climb 



* Upham : Amer. Geologist, vol. iv, 1889, pp. 165 and 205. 

 fProc. Amer. Assoc. Adv. Sei., vol. xxiv, part ii, 1875, pp. 92-9G. 

 1 Bull. Museum Comp. Zoology, vol. vii, 1881, pp. 189-223. 

 I Upham : Amer. Geologist, vol. iv, 1889, pp. 105 and 205, 



