31S 



Geology, ^c. of Tennessee, ^c. 



county, and Mr. Robert Grattan ; which, with an explanation, 

 and particular description, I hope to be able to transmit to you 

 at a future time. 



From these surveys, it appears that the whole extent of the 

 cave, hitherto discovered, does not exceed eight hundred yards. 

 This was the length stated to me by the guide, when I visited 

 it in August, 1817. I cannot but think there is some mistake 

 in Mr. Kain's remark, that " it is a mile and a half in extent.'' 

 I spent four hours in examining every accessible part, and by 

 permission of Mr. Henry Bingham, the owner, made a large 

 collection of specimens, which were transmitted for the Cabi- 

 net of Yale College.* 



The Natural Bridge, 



2. My object in naming this celebrated curiosity, is not to 

 give a new description of it, but merely to furnish a correct 

 account of its dimensions. I visited it in company with the 

 Rev. Mr. Huson, who had previously found its height by a 

 cord, to be two hundred and ten feet. We now found it by 

 the quadrant, to be two hundred and eleven feet, and the arch 

 through the centre about forty feet. 



Some have attempted to account for this great curiosity, by 

 supposing that a convulsion in nature may have rent the hill, 

 in which it stands, asunder ; thus forming the deep and narrow 

 defile, over which the rocky strata were left, which constitute 

 its magnificent arch. If so, the sides should have correspond- 

 ing parts. At a distance from the base, no such correspondence 

 is perceptible. At the base, the rocks are more or less craggy 

 and irregular. This led me to take the courses and distances 

 of each side. The following was the result. 



Eastern side presents 4 angular points. 



1. N. 55" W. 1 chain. 09 links. 



2. N. 72 W. 1 05i 



3. N. 57 W. 1 — ^ 12| 



4. N. 50 W. 33 



Western side presents 3 angular points. 



* See Number 1. page 59. 



