AGRICULTURAL GEOLOGY. 189 



It does not appear that the distribution of plants in this region is 

 inlluenced by the kind of rock which lias furnished the subsoil, with 

 llie exception of a few instances in which a limestone basis seems 

 Lo have produced spots congeflial to a peculiar growth. 



Face of the country. 



All that is peculiar to the surface of this region, may be described 

 n a few words. It is, in the first place, hilly, and the hills are long 

 owards the more mountainous parts, and run north and south. To- 

 wards the western slope, adjacent to the valley of the Hudson, 

 hey are more rounded, like haycocks, and rise up from circular 

 epressions, many of which are peat swamps with marl, and always 

 lontain more or less muck. The hills are frequently composed of 

 ounded gravel, but sometimes qf that kind called flat gravel. Upon 

 he extreme eastern border, the hills are highly charged with cobble- 

 tone, derived form the granular quartz. Cobblestone almost as 

 urable, of a reddish kind, occurs in the western hills, derived from 

 16 Potsdam sandstone and a siliceous variety of the Calciferous 

 andstone. 



The hills under consideration are those usually called " drift 

 ills ;" that is, they were formed by the great northern current of 

 faXer which passed over this country at a former epoch. The time 

 hen this event happened is not determined, only it was one of 

 le latest of the great changes which have happened, and which 

 rere preparatory for the residence of man. We regard the drift 

 urrent, then, as having given shape to this country ; as having worn 

 own all the asperities of the rocks ; as having mingled the soils 

 'om the different rocks ; in fine, as having performed in these re- 

 lects most essential changes of the surface, and such as were well 

 Iculated to favor the operations of the husbandman. 



The actual elevation of some places will convey to the reader a 

 Btter idea of this region, than if we confined ourselves to general 

 atements. Along the eastern margin of the region, in Massachu- 

 >tts, we have the following elevations, namely : Bed of the Hoosic 

 ver at Williamstown, 580 feet ; Adams village, 764 ; Lenox vil- 

 ge, 1178 ; Piltsfield, 1035 ; Richmond, 1091 ; all estimated above 

 de at Albany. Sheffield rises 630 feet above tide water at Derby 



Connecticut. The elevation of the Taconic range, between New- 

 ork and Massachusetts, is from 1200 to 1600 feet. From this 



