GLACIAL PHENOMENA IN MAINE. 
115 
ence to glacial phenomena. To the north of 
the Iron Works there are two ranges of hills, 
one to the east, the more prominent masses 
of which are respectively known by the names 
of Horseback and Spruceback, while to the 
west corresponding summits have been chris¬ 
tened the Iron Mountain and Chairback. These 
two ranges are separated by a depression called 
the Gulf, at the foot of which, between Horse¬ 
back and Iron Mountain, there lies a little lake. 
Here a practised eye will at once detect the 
unmistakable action of a glacier in two suc¬ 
cessive periods of its history. In the direction 
of Iron Mountain and the Chairback, one hun¬ 
dred feet and more above the level of the lake, 
may be seen old lateral moraines, more or less 
disintegrated, marking an ancient glacial level. 
At a much less height, indeed but little above 
the bottom of the valley, a magnificent cres¬ 
cent-shaped terminal moraine is thrown across 
the southern end of the lake. By this wall 
the waters drained from the wdiole valley are 
held back to form a lake, although the barrier 
is not perfectly impassable, for a little stream 
oozes through it, just in front. Evidently 
this moraine is an accumulation of loose ma- 
