112 GLACIAL PHENOMENA IN MAINE. 
south, though their course is somewhat wind¬ 
ing, seldom following a perfectly straight line. 
They are unquestionably of a morainic nature, 
and yet they are not moraines in the ordinary 
sense of the term, but rather ridges of glacial 
drift heaped up in this singular form, as if 
they had been crowded together by some lat¬ 
eral pressure. Had they been accumulated and 
carried along upon the edge of the glacier, 
they could not be found in their present posi¬ 
tion. They differ also from moraines proper 
in their rounded materials, containing many 
scratched and polished pebbles, while moraines 
are built chiefly of angular fragments of rocks. 
Neither can they have been accumulated by 
currents of water; for they occur in positions 
where any flood passing over the country, far 
from producing such an arrangement, must 
have swept them away, or at least have scat¬ 
tered them and destroyed their ridge-like char¬ 
acter. They are, indeed, identical with the 
bottom glacial drift, that is, with the materials 
collected beneath the present glaciers, and 
ground to a homogeneous paste by their press¬ 
ure and onward movement. I would call 
such accumulations ground moraines , that is, 
