68 HISTORY of the SOCIEtT. 



One of the places where he knew that a junction of the kind 

 he wifhed to examine muft be found, was the line where the 

 great body of granite which runs from Aberdeen weftward, 

 forming the central chain of the Grampians, comes in contact 

 with the fchiftus which compofes the inferior ridges of the fame 

 mountains toward the fouth. The neareft and mofl accefllble 

 point of this line feemed likely to be {ituated not far to the eaft- 

 ward of Blair in Athol, and could hardly fail to be vifible 

 in the beds of fome of the mofl northern dreams which run 

 into the Tay. Dr Hutton having mentioned thefe circum- 

 ftances to the Duke of Athol, was invited by that nobleman to 

 accompany him in the (hooting feafon into Glentilt, which he 

 did accordingly, together with his friend Mr Clerk of Elden, in 

 fummer 1785. 



The Tilt is, according to the feafons, a fmall river, or an im- 

 petuous torrent, which runs through a glen of the fame name, 

 nearly fouth-weft, and deeply interfects the fouthern ridges of 

 the Grampian Mountains. The rock through which its bed is 

 cut is in general a hard micaceous fchiftus ; and the glen pre- 

 fents a fcene of great boldnefs and afperity, often embellifhed, 

 however, with the accompaniments of a fofter landfcape. 



When they had reached the Foreft Lodge, about feven miles 

 up the valley, Dr Hutton already found himfelf in the midft 

 of the objects which he wifhed to examine. In the bed of the 

 river, many veins of red granite, (no lefs, indeed, than fix large 

 veins in the courfe of a mile), were ieen traverfing the black 

 micaceous fchiftus, and producing, by the contraft of colour, an 

 effect that might be ftriking even to an unfkilful obferver. The 

 fight ot objects which verified at once fo many important con- 

 clufions in his fyftem, filled him with delight; and as his feelings, 

 on fuch occafions, were always ftrongly expreffed, the guides 

 who accompanied him were convinced that it muft be nothing 



lefs 



