On GRANITE, 70 



# /y 



the Alpine ftrata ; that is to fay, I wanted to fee, whether the 

 granite mafs, in point of time, had been prior or pofterior to 

 thefe water-formed bodies ; and, as to the manner of operation, 

 I particularly defired to know, if that granite had been made to 

 flow, in the ftate of fufion, among the broken and diflocated 

 ftrata. 



Having thus fufpended my opinion, until I fhould have an 

 opportunity of finding fome decifive appearance, by which 

 this important queftion might be determined with certainty, I 

 confidered where it might be mofl likely to find the junction of 

 the granite country with the Alpine ftrata. Mr Clerk of Eldin 

 and I had an engagement to vifit the Duke of Athol, at Blair. 

 I concluded, that from Blair it could not be far before the great 

 mafs of granite, which runs fouth-weft from Aberdeen, would 

 be met with, in afcending the river Tilt, or fbme of its branches. 

 Mr Clerk and I were, however, refolved to find it out, to what- 

 ever diftance the purfuit might lead us among the mountains of 

 this elevated track. Little did we imagine that we fhould be 

 £0 fortunate as to meet with the object of our fearch almoft upon 

 the very fpot where the Duke's hunting-feat is fituate, and where 

 we were entertained with the utmoft hofpitalky and ele- 

 gance. 



It is in Glen Tilt, and precifely in the bed of the river, that 

 this jundion is formed of the granite with the Alpine ftrata. 

 But this circumftance, of being in the bed of the river, where 

 the rocks are often wafhed bare, is of fuch importance, that 

 had this jun&ion been only to be found in the mountains co- 

 vered with heath and mofs, we might have been upon the fpot, 

 and yet been ignorant of the molt material circumftances of the 

 fact, which we wanted to explore. 



I here had every fatisfadion that it was pofhble to defire, 

 having found the mod perfeft evidence, that the granite had been 

 made to break the Alpine ftrata, and invade that country in a 

 fluid ftate. This correfponded perfeftly with the conclusion 



which 



