358 REMARKABLE TRAINS OF ERRATIC BLOCKS. CHAP. xvm. 



m Dupey's Mount. 



n Largest block of train, No. 6. See figs. 51 and 52, p. 359. 



p Point of divergence of part of the train No. 6, where a branch is sent off 

 to No. 5. 



No. 1 The most southerly train examined by Messrs. Hall and Lyell, 

 between Stockbridge and Kichmond, composed of blocks of black slate, blue 

 limestone, and some of the green Canaan rock, with here and there a boulder 

 of white quartz. 



No. 2 Train composed chiefly of large limestone masses, some of them 

 divided into two or more fragments, by natural joints. 



No. 3 Train composed of blocks of limestone and the green Canaan rock ; 

 passes south of the Kichmond Station on the Albany and Boston railway; is 

 less defined than Nos. 1 and 2. 



No. 4 Train chiefly of limestone blocks, some of them thirty feet in 

 diameter, running to the north-west of the Eichmond Station, and passing 

 south of the Methodist Meeting-house, where it is intersected by a railway 

 cutting. 



No. 5 South train of Dr. Eeid, composed entirely of large blocks of the 

 green chloritic Canaan rock ; passes north of the Old Eichmond Meeting-house, 

 and is three-quarters of a mile north of the preceding train (No. 4). 



No. 6 The great or principal train (north train of Dr. Eeid), composed of 

 very large blocks of the Canaan rock, diverges at p, and unites by a branch 

 with train No. 5. 



No. 7 A well-defined train of limestone blocks, with a few of the Canaan 

 rock, traced from the Eichmond to the slope of the Lenox range. 



trains 5 and 6 have evidently come from the ridge A, 

 and a large proportion of the whole from its highest summit, 

 d, where the crest of the ridge has been worn into those dome- 

 shaped masses called f roches moutonnees,' already alluded to 

 (pp. 269 and 293), and where several fragments having this 

 shape, some of them thirty feet long, are seen in situ, others 

 only slightly removed from their original position, as if they 

 had been just ready to set out on their travels. Although 

 smooth and rounded on their tops, they are angular on their 

 lower parts, where their outline has been derived from the 

 natural joints of the rock. Had these blocks been conveyed 

 from d by glaciers, they would have radiated in all directions 

 from a centre, whereas not one even of the smaller ones is 

 found to the westward of A, though a very slight force would 

 have made them roll down to the base of that ridge, which is 

 very steep on its western declivity. It is clear, therefore, that 

 the propelling power, whatever it may have been, acted 

 exclusively in a south-easterly direction. Professor Hall and 



