Query Vl

Pignut ridge of mountains; thence it paffes on nearly parallel with that, and crofTes the Rivanna about five miles below it, where it is cal- led the South-weft-ridge. It then crofles Hard-ware, above the mouth of Hudfon's creek, James' river at the mouth of Rock- fifh, at the marble quarry before fpoken L 55 ] of, probably runs up that river to where it appears again at Rofs's iron-works, and fo pafles off fouth-weftwardly by Flat cceek of Otter river. It is never more than one hundred yards wide. From the Blue ridge weftwardly, the whole country feems to be founded on a rock of lime-flone, befides infinite quantities on the furface, both loofe and fixed. This is cut into beds, which range, as the mountains and fea-coaft do, from fouth-weft to north- eaft, the lamina of each bed declining from the horizon towards a parallelifm with the axis of the earth. Being ftruck with this obfervation, I made, with a quadrant, a great number of trials on the angles of their declination, and found them to vary from 22^- to 6o''; but averaging all my trials, the refult was within one-third of a degree of the elevation of the pole or latitude of the place, and much the greateft part of them taken feparately were little different from that: by which it appears, that thefe lamina are in the main, parrallel with the axis of the earth. In fome inftances, indeed, I found [ 5(> ] them perpendicular, and even reclining the other way; but thefe were extremely rare, and always attended with figns of convulfion, or other circumftances of An- gularity, which admitted a poflibility of removal from their original pofition. Thefe trials were made between Madifon's cave and the Patowmac We hear of lime- ftone on the Miffifipi and Ohio, and in all the mountainous country between the eaftern and weftern waters, not on the mountains themfelves, but occupying the vallies between them Near the eaftern foot of the North mountain are immenfe bodies of Schijl^ containing imprefTions of fhells in a variety of forms. I have received petrified fliells of very different kinds from the firft fources of the Kentucky, which bear no refemblance to any I have ever feen on the tide-waters. It is faid that fhells are found in the Andes, in South-America, fifteen thoufand feet above the level of the ocean. This is