Dewey on Geology of Williamstown, ^c, 339 



part (E) 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 apeak 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 hundred 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 pnmtVtTJe; 

 lying on the west of the summit of the primitive range, which 

 passes southerly into Connecticut. The rocks and minerals 

 will 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 colour ; the mica black, and 

 the rocks exceedingly hard. I hare never noticed any mine- 

 rals imbedded in it. The vortex of Pownal mountain is also 

 granitic. 



2. Gneiss and Mica Slate. I connect these two, because 

 they are not often distinct, and appear to pass into each other. 

 They are found in large strata on Hoosack Mountain, on a hill 

 (L) connected with Saddle Mountain, and on the east side of Sad- 

 tie 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 



