‘Dewey on Geology of Williamstown, Gc. 339 
part () of the west range is nearly two miles in length, and 
rises to the height of eighteen hundred feet; the southern (I) 
rises abruptly into a peak of the elevation of seventeen hundred 
feet. The height of the valley between the two ranges is about 
fourteen hundred feet. You enter the Hopper from the west, . 
passing along a branch of Green River, and a romantic, wild, 
and sublime prospect opens before you. Nearly east of the 
entrance into the Hopper, lies the highest point of the Saddle, 
familiarly called Gray Lock, (F) being about twenty-eight hun- 
dred feet above the college, and probably four thousand feet 
above the tide-water of the Hudson at Troy. This is the high- 
est land in Massachusetts. About two miles north northeast, 
is the northern peak (G) elevated twenty-three hundred feet. 
The valley in Adams is bounded on the east by Hoosack 
mountain, (K) elevated from fourteen bundred to eighteen hun- 
dred feet, and extending several miles west of south: it forms 
a part of the range which commences at West Rock in Con- 
necticut. 
The country included in this sketch is principally primitive ; 
lying on the west of the summit of the primitive range, which 
passes southerly into Connecticut. The rocks and minerals 
wil be mentioned in the following order. 
1. Granite. A few pieces have been found at the foot of 
Oak hill, one mile-northeast of the college. It consists prin- 
Cipally of feldspar. Four miles east, are large masses of gra- 
nite on both sides of the Hoosack, and on ascending Hoosack 
Mountain they become more numerous. The principal part of 
this is quartz, often of a purple color; the mica black, and 
the rocks exceedingly hard. I have never noticed any min- 
erals imbedded in it. The vertex of Pownal mountain is also 
Stanitic. 
2. Gneiss and. Mica Slate. 1 connect these two, because 
they are not often. distinct, and appear to pass into each other. 
They are foundin large strata on Hoosack. Mountain, om a hill 
(L) connected with Saddle Mountain, and on the east'side of Sad- 
dle Mountain. The highest and the west ridge of Saddle Moun- 
tain are mica slate. The Hopper shows the inclination of the 
strata quite to. the base of the mountain. The: inclination is to 
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