Geology, ^c, of the Connecticut. 85 



subject,) that a careful examination of the bowlder stones 

 along the Connecticut would favor the supposition. Mas- 

 ses of greenstone are found at a greater distance, and in 

 much greater quantities on the western side of the ridges 

 than on the eastern. As we ascend the primitive region 

 on the west side of the river, secondary rolled stones are 

 seen for one or two miles ; but on the eastern side, if I 

 mistake not, nothing of this kind appears ; and I should 

 suppose the bowlders of Woodbridge and Miiford, being 

 evidently brought from the country to the north, would tes- 

 tify in favor of such an hypothesis. 



Suggestion concerning rolled Stones. 



Is it not a fact that rolled masses are more abundant and 

 more perfectly rounded along the limits between the primi- 

 tive, and transition, or secondary ? This question has often 

 occurred to me when travelling in the south eastern part of 

 Massachusetts, when going over the country along the 

 Connecticut in Bernardston and its vicinity, when descend- 

 ing the Hoosack and Green Mountains on the west, and 

 when passing over the country west of New-Haven. If 

 *uch be the fact it may, when it occurs in the geologist's 

 tours, be a warning to him to expect a change in the rocks 

 in place. 



Fact relating to the detachment of large bowlder stones from 

 their bed. 



Deerfield river in the greater part of its course is a 

 mountain torrent, very rapid and powerful. It has worn 

 a passage often four hundred feet deep, the banks being al- 

 most perpendicular. Its winter floods are most powerful 

 in effecting this work. The ice freezes three or four feet 

 thick, and when a sudden rain melts the snows on its banks, 

 it rises rapidly and lifts up and urges forward with tumultu- 

 ous fury, this immense body of ice. As the banks among 

 the mountains are steep and rocky, they prevent the ac- 

 cumulation of water and ice from spreading to the right or 

 left, and it is raised proportionally higher ; and thus an im- 

 mense force is exerted upon obstacles in the bottom of the 



