27 



is called the South-west ridge. It then crosses Hard- 

 ware, above the mouth of Hudson's creek, James' river 

 at the mouth of Rockfish, at the marble quarry before 

 spoken of, probably runs up that river to where it ap- 

 pears again at Ross's iron works, and so passes off 

 south-westvvardly by Flat creek of Otter river. It is 

 never more than one hundred yards wide. From the 

 Blue ridge westward ly, the whole country seems to be 

 founded on a rock of hme-stone, besides infinite quan- 

 tities on the surface, both loose and fixed. This is cut 

 into beds, which range, as the mountains and sea-coast 

 do, from south-west to north-east, the lamina of each 

 bed declining from the horizon towards a parallelism 

 with the axis of the earth. Being struck with this ob- 

 servation, I made, with a quadrant, a great number of 

 trials on the angles of their declination, and found them 

 to vary from 22^ to 60° ; but averaging all my trials, 

 the result was within one third of a decree of the ele- 

 vation of the pole or latitude of the place, antl much 

 the greatest part of them taken separately were little 

 different from that : by which it appears, that these 

 lamina are in the main, parallel with the axis of the 

 earth. In some instances, indeed, I found them per- 

 pendicular, and even reclining the other way : but these 

 were extremely rare, and always attended with signs 

 of convulsion, or other circumstances of singularity, 

 which admitted a possibility of removal from their 

 original position. These trials were made between 

 Madison's cave, and the Patowmac. We hear of lime- 

 stone on the Mississippi and Ohio, and in all the moun- 

 tainous country between the eastern and western wa- 

 ters, not on the mountains themselves, but occupying 

 the valleys between them. 



Near the eastern foot of the North mountain are im- 

 mense bodies of Schist, coxna\ning impressions of shells 

 in a variety of forms. I have received petrified shells 

 of very different kinds from the first sources of the 

 Kentucky, which bear no resemblance to any I have 

 ever seen on the tide waters. It is said that shells are 

 found in the Andes, in South America, fifteen thousand 



