BOWLDERS. 57 



limestone, for instance, are rarely seen, even when we know from the direction in which 

 drift was transported, that they must have been torn off from the ledges. Thus we know 

 that the vast amount of drift covering the western slopes and higher parts of the Green 

 Mountains was mainly derived from the valleys and lesser ridges lying west of those moun- 

 tains ; and although those valleys are mainly underlaid by limestone, yet fragments of it 

 are rare among the hard blocks of quartz, gneiss, &c. of the drift. This fact, as well as the 

 rounded form of most of the masses, shows that they were driven along the surface me- 

 chanically sometimes, although other facts show that they must also have been sometimes 

 transported from one spot to another without touching the surface. 



The great size and weight of these bowlders sometimes impresses the observer with the 

 great energy of the force by which they were transported over deep valleys and up the 

 sides of lofty mountains. I will give a few examples. 



An inspection of the Geological Map will show a deposit of granite in the southwest 

 part of the state, forming the high hill lying between Stamford and Pownal, which is 

 almost as high as the Green and Hoosac Mountains east and southeast. Over those 

 mountains the drift took a southeasterly direction. The consequence has been that all 

 the western side of the Green and Hoosac Mountains is strewed over with bowlders of 

 this granite. Indeed they extend southeastei'ly over the very hilly region in that direction, 

 nearly across Massachusetts. It is a kind of rock easily distinguished from all others by 

 its tendency to disintegration, by its blue quartz and the porphyritic aspect given to it by 

 its oval foliated masses of feldspar. Being associated with quartz rock in Oak Hill, from 

 whence it starts, bowlders of the latter rock accompany the granite in its dispersion. Nay, 

 the quartz being much the hardest, its bowlders extend southerly much the farthest, being 

 strewed over the whole width of Connecticut as well as Massachusetts, and not uncom- 

 mon in the drift and modified drift of Long Island. But if any one wishes to get strong- 

 ly impressed with the tremendous power exerted by the drift agency, let him pass up 

 the hill west of Stamford towards Pownal, and he will be amazed at the accumulation and 

 size of the bowlders, chiefly of granite, here almost covering the surface and preventing 

 cultivation. We know of no place in Vermont better adapted to show the dynamics of 

 drift than this, although many others of a striking character might be named. 



There is one bowlder of this granite, however, which from its size and situation we 

 would point out, although it has been carried a little distance over the line into Massa- 

 chusetts. (Fig. 20.) Ascending Hoosac Mountain from North Adams into Florida on 

 the Greenfield road, and turning northerly at its top so as to pass near the edge of the 

 mountain a mile and a half in an unfrequented path, we come at length, in the midst of 

 the woods, upon the huge bowlder of Stamford granite figured below from a hasty sketch. 

 It lies nearly all out of the ground, resting on the ledges of slate beneath the thin soil. 

 Its height is 15 feet, and it is 76 feet in circumference, weighing by estimation 510 tons. 

 Few other bowlders are near it, and if the trees were cleared away it would be a striking 

 object, especially if we turn our eyes westward and look into the valley running from 

 Stamford southerly through Adams, and which is over 1300 feet deep. On its northwest 

 side rises Oak Hill, which is some 200 feet higher than the bowlder, and where the granite is 

 in place, from which some agency has torn it off and transported it many miles across the 

 intervening valley 1300 feet deep. The fact seems the more striking because the western 



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