AMERICAN GEOLOGY — DECAD.E OE 1840-1849. 



403 



Berkshire (Richmond) bowlder train, first brought to notice by Hitch- 

 cock (see p. 394). 



According' to the descriptions now given, the trains start, each from 

 its particular depression in the summit of a high ridge, in Canaan, New 

 York. Taking a direction S. 35° E M they cross the higher ridges and 



S ^2SLD 



Fig. 42.— Sketch map of Richmond Bowlder Train. (After E. R. Benton.) 



their intervening valleys, the longer for a distance of 20 miles and the 

 shorter for 1<> miles. The individual trains are neither of them more 

 than 300 or 400 feet in breadth, and not over half a mile asunder. 

 The transported blocks are of all sizes up to 20 feet in diameter, 

 sharply angular, free from scratches, and all of the same lithological 



