/ 



374 



ILLUSTRATIONS OF THE 



which is the bafe of this heath, as far as can bc; 

 difcovered, is limeftone, and over the furface 



r 



of it large flints, in the form of gravel, are 

 very thickly fpread. There is no higher ground 

 in the neighbourhood from which this gravel 

 can be fuppafed to have come, nor any ftream 

 that can have carried it, fo that no explanation 

 of it remains, but that it is formed of the flints 



r 



contained in beds of limcfl:one, which are now 

 wom away. The flints on the heath are pre- 

 cifely of the kind found in lim^one ; ma- 

 ny of them are not much worii, and cannot 

 have travelled far from the rock in which 



they 



ginally contained. It feems cer- 



tain, therefore, that they are the dehr'is of 

 Hone ftrata, now entirely decompofed, that 

 lay above the ftrata which at prefent 



forni 



the bafe 



f th 



elevated 



and proba 



bly covered them to a conliderabl 



height 



This explanation carries the greater probability 



th 



It, that any other way of accounting for 

 the fad: in queflion, as the travelling of the gra- 

 vel from higher grounds, or the immerfion of 



the furf 



under the fea 



ill imply chang 



th 



the face of the country, incomparably gre 

 m are here fuppofed. Our hypothefis fe 



give the minimum of 



the kinds of chang 



that can poffibly account for the pheij 



336. The 



