170 Glaciation of Mountains, Etc. — TIphara. 
resembling the peaks and ridges of the Andes. Instantly the 
idea occurred to us that such a narrow ridge could never have 
been shaped by drift action. Its sides are covered with those 
loose angular blocks which frost has removed from the ledges 
but drift has never transported, precisely like the fragments 
upon the top of Mt. Washington above the drift region. We 
searched in vain over all the top of Mt. Katahdin for any 
signs of drift action. There are no strife upon the ledges, 
no smoothing or rounding of the rocks, and no transported 
bowlders anywhere upon the summit. This view is strength- 
ened by the fact that there are no transported rocks in the 
Basin, into which an innumerable quantity of bowlders would 
have been hurled if the drift agency had ever crossed the 
summit. 
"Only one feature appeared favorable to the view that the 
drift passed over the top. The whole of the northwest side of 
the summit appears like one great stoss side, while the lee 
side is very ragged, just as would be the case if the ice went 
over the top. But in answer to this it may be said, this appar- 
ent stoss side is only the natural shape of the mountain, and its 
position accidental. This view is partially confirmed by the 
fact that for a great distance from the summit on the north- 
west slope no ledges can be seen, only the fragments which 
have been loosened by frost. Generally, when ledges have 
been struck by drift, even if the scratches are obliterated, the 
rocks are not so thoroughly split up by frost but that the 
rounded ledges remain very slightly affected. This is certainly 
the case upon Mt. Washington. The drift force seems often 
to have been strong enough to remove all the loose and prom- 
inent parts of ledges, leaving the solid foundation so firmly 
rooted that atmospheric agencies have not yet had time 
enough to break them up. We are fully satisfied that a large 
part of the Katahdin summits have never been swept over by 
drift, even if we must believe that the highest portion has 
been struck."' 
Professor A. S. Packard, Jr, compares the aspect of the top 
cf Katahdin, "strewn thickly with huge angular blocks broken 
off by frosts from the subjacent strata," with Mt. Washing- 
' Sixth Annual Report of the Secretary of the Maine Board of Agri- 
culture, 1861. 
