by E. Cornelius. 221 



the limestone of this division from that already described, is 

 this, ITS STRATA ARE HORIZONTAL. Frequently immense piles 

 may be seen forming bold precipices, but always in horizontal 

 layers, differing in thickness, from a few inches to many feet. 

 How far this arrangement extends to the west and north, I 

 have not yet been able to learn. Travellers always speak of 

 the limestone rocks in West Tennessee and Kentucky asjlat, 

 from which circumstance I conclude that the Cumberland 

 mountain forms for a considerable distance at least, the eastern 

 boundary. I have observed but three other particulars in 

 which the strata of the horizontal differ from those of the 

 inclined limestone. 



1. Its colour is not sc strongly marked with the bluish tinge. 



2. It is not so commonly penetrated with white veins of a 

 semicrystaUized carbonate of lime ; nor is it so frequently as- 

 sociated with the uneven fractured species. 



3. Petrifactions are oftener found in it. 



I will here take the liberty to suggest, whether in our maps 

 of geology, some notice should not be taken of this very im- 

 portant division in the limestone country. Such a division ex- 

 ists in fact ; nature has made it ; and if geology depends on na- 

 ture for its only legitimate inductions, there can be no reason 

 why a feature so prominent as this, should be overlooked. 

 I shall not undertake to account for their difference : but would 

 not every geological theorist consider them as distinct for- 

 mations ?* 



Cumberland Mountain. 



The Cumberland mountain, which forms a part of this di- 

 viding line, is itself a singular formation. It belongs to the 

 class called " Table mountains." Its width varies from a few 



* The modesty of the writer has prevented him from applying to the formations 

 which he has well described, the terms transition and secondary, which there can 

 be little doubt do in fact belong to them. His strata of highly inclined limestone, 

 appear to belong to the transition class of Werner, and his flat strata, to the se» 

 condary. It may be observed in this place, that the specimens alluded to in the 

 text (passim,) appear to be correctly described by Mr. Cornelius, and to justify 

 his geological inferences as far as hand-specimens seen at a distance from their 

 native beds, can form a safe basis for general geological inductions. Editor. 



