88 Sir Charles Lyell [April 27, 



d. Knob in the range A, from -which most of the train No. 6, is supposed to 

 have been derived. 



c. Supposed starting point of the train No. 5, in the range A. 



f. Hiatus of 175 yards, or space without blocks. 



g. Sliorman's House. 

 h. Perry's Peak. 



k. Flat Rock. 



/. Merriman's Mount. 



in. Dupey's Mount. 



n Largest block of train, No. 6. 



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 Richmond, 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 Richmond 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 30 feet in diameter, 

 running to the north-west of the Richmond Station, and passing south of the 

 Methodist Meeting-house, where it is intersected by a railway cutting. 



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

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

 and is three-quarters of a mile north of the preceding train fNo. 4). 



No. 6. The great or principal train (north train of Dr. Reid), 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 Richmond to the slope of the Lenox range. 



Dr. Reid, the agriculturist of Berkshire, first called attention in 

 1842 and 1845 to these phenomena. Professor Hitchcock con- 

 tributed many valuable observations in 1844, and Professors Henry 

 D. and William B. Rogers treated of the same subject in 1846.* 

 The district was re-examined in October 1852, by Professor J. 

 Hall and Sir Charles Lyell, by whom some of the data referred to 

 in this discourse were ascertained. Within the area particularly 

 referred to, the trains Nos. 5 and 6 are the most conspicuous, by 

 their length and by the magnitude and frequency of the blocks 

 composing them. These fragments consist of a green chloritic 

 rock, remarkably tough, sometimes compact, but occasionally 

 schistose. It is met with in place at c/, in the highest crest of 

 the Canaan ridge, and reappears in its more slaty form in the 

 western division of the Richmond ridge B. at Z, or Merriman's 

 Mount. It passes on the one hand into a quartzose conglomerate, 



* " Boston Journal of Natural History," for .Tune 1846. 



