414 Natural Bridge in Virginia. 



peninsula of East Florida, to the exploring of which I mean to 

 devote some time. — Very faithfully your's, 



John James Audubon. 



NATURAL BRIDGE IN ROCKBRIDGE COUNTY, VIRGINIA. 



The celebrity which Mr. Jefferson, in his Notes on the State of 

 Virginia, gave to this remarkable natural curiosity, has been 

 deservedly great. He has very eloqently expressed the emotions 

 which an upward view of this " arch, so elevated, so light, and 

 springing as it were up to heaven," excites in the spectator. 



In a geological point of view, it is in all respects the same as 

 the natural tunnel so well described by Lt. Col. Long, in our 

 last number ; being originally a natural cavity in the limestone 

 rock, (carboniferous,) enlarged by the disintegration of the 

 rock in long periods of time. Cedar creek, the small stream 

 which passes under it, has its source only about two miles from 

 the bridge, where it is only from 20 to 30 feet wide. It cannot 

 be readily supposed, that a limited drainage of this nature could 

 have perforated this rock ; we therefore suppose, and for the 

 reasons given in our remarks on Lt. Col. Long's paper, that the 

 stream has always escaped through one of those natural cavities, 

 so abundant in this limestone. The height of the two spurs thus 

 traversed by Stock creek in Scott county, and Cedar creek, in 

 Rockbridge county, are nearly the same; but on account of the 

 comparatively small extent of this natural bridge, which is, as 

 it were, a cavity in the open air, the disintegration of the rock 

 has been much more rapid. In process of time, if nothing is done 

 to arrest annual waste, the whole mineral substance which now 

 forms the arch, will fall to the bottom, leaving a chasm resem- 

 bling that described by Ulloa, in Angaraez, of which Mr. Jefferson 

 speaks in a note. It is in this slow but sure way, that the ap- 

 pearances on the surface of the earth, arc constantly undergoing 

 a variety of changes ; especially cavernous hills, exposed to the 

 action of external circumstances. 



The comparative dimensions of the natural tunnel, and the 

 natural bridge are as follows : 



