34 



UNITED STATES 



hence concludes that this valley has in the beginning 

 been a branch or inlet of the ocean, which received 

 into its bosom this great river. All this prodigious 

 space is now filled with soil more or less solid, and 

 at Natchez is 100 feet above the level of the sea !* 



Of the alluvial nature of the soil of many parts of 

 our continent there are additional proofs. 



On the shores of York river the bones of whales 

 abound ; and in walking the sand beach of that river, 

 during the recess of the tide, and looking up at the 

 high cliif or bank above, we find strata of sea shells 

 not yet decomposed, of the same kind as those which 

 lay on the beach under the feet, interposed with strata 

 of earth (the joint result, no doubt, of sand and pu- 

 trid vegetables), exhibiting at once a sample of the 

 manner in which the adjacent soil had been formed, 

 and proof of the comparatively recent deposition of 

 the waters. t 



The noble hill on which the Capitol or Congress 

 House at Washington has been erected, is more than 

 eighty feet above the level of the tide-water, and 

 about sixty or seventy above the level of the adjacent 

 or low ground. In all probability this high ground 

 formerly extended much nearer to the channel 

 where now the Potowmack ruhs ; and it is equally 

 probable that, in distant ages, the bed of that stream 

 was not near so deep as it is at present, nor capable 

 of containing so much water. Consequently, in the 

 remote ages alluded to, all the low land betv/een the 



* Trans. Amer, Phil.lSoc* Vol. vi. 



