86 Sir Charles Lyell [April 27, 



WEEKLY EVENING MEETING, 



Friday, April 27. 



The Duke of Northumberland, K.G. F.R.S. President, 

 in the Chair. 



Sir Charles Lyell, F.R.S. 



On certain Trains of Erratic Blocks on the Western borders of 

 Massachusetts^ United States. 



On the western borders of the State of Massachusetts, in Berkshire, 

 and on the eastern confines of the adjoining State of New York, a 

 great number of erratic blocks are seen, remarkable for their large 

 size and their distribution in long parallel trains, each of them 

 continuous in nearly straight lines over hill and dale, for the dis- 

 tance of five, ten, or twenty miles or more. These trains are of 

 geological interest, not only from their length, and the size of the 

 blocks, but also from the precision with which they can be traced 

 to their starting points, and the low latitudes in which these starting 

 points are situated. The area alluded to occurs in lat. 42° 25' south, 

 corresponding to that of the north of Portugal ; and the western 

 borders of Berkshire, where they join the State of New York, are 

 about 130 miles from the Atlantic coast, in a direction due west of 

 the city of Boston, in Massachusetts. 



In the accompanying plan. Fig. 1, it will be observed that the 

 mountain ranges ABC run N.N.E. and S.S.W., whereas the 

 trains of erratic blocks (from No. 1 to No. 7 inclusive,) have a 

 direction nearly transverse to these ranges, and consequently to the 

 intervening valleys, their direction being about N.W. and S.E. 

 In one sense we may affirm that the course of the stones has no 

 relation whatever to the present configuration of the country, be- 

 cause the present drainage or flow of the rivers is quite in a different 

 direction ; but in another point of view we shall find that a close 

 relation can be made out between the actual inequalities of hill 

 and dale, and the course and mode of dispersion of the erratics ; so 

 that there is good reason to infer that the superficial inequalities 

 were very nearly what they are now, before any of the trains 

 originated. 



