1813.] made In the Highlands of Scoiland. Bi 



Ambleree to Glenalmond we found the same formation. This 

 glen struck us as narrower and more confined than any we had 

 icen, and the rocks on each side are extremely precipitous. Still 

 mica slate strata nearly vertical ; but as soon as we had got a 

 mile, or a mile and a half, down from the bridge, we came upon 

 transition rocks, grey wacke, and grey wacke slate. We saw also 

 about 6'0 yards up the hill on our right a small quarry, in what 

 we deemed to be clay slate. Indeed, we had no doubt of its 

 being so, from some fragments we found on the road. On 

 advancing some miles farther on our way towards Crieff, we again 

 fell in with the conglomerate. 



On our way from Crieff to Comrie, near the House of Lawers, 

 on the right hand side of the road, I observed in the conglome- 

 rate a very distinct nodule of mica slate ; the only one of the sort 

 I saw in all this district. I nowhere observed any granite or 

 gneiss nodules. 



The country, looking west from Comrie, is primitive, and 

 extremely bold. And the view up the Ern towards Duneira, a 

 distance of nine miles, is picturesque in a high degree. On a 

 well-chosen eminence to the north of Comrie they are erecting 

 a monument to the memory of the late Lord Melville, of a 

 beautiful variety of sienite, in which the felspar is almost snow 

 white. 



About three miles to the south of Comrie the road is cut 

 through the conglomerate, in some places to the depth of 20 

 feet. The nodules almost all of the trap kind, amygdaloid, trap- 

 tuff, basalt, greenstone, wacke, grey wacke, hornstone porphyry. 

 From this place to the bridge of Ardoch (nine miles) the rock 

 appeared every where, to be the old red sandstone of a small 

 grain, such as we observed it in the bottom of the river at the 

 bridge of Doune ; and nothing but sandstone presented itself till 

 we came into Glenagles, which enters the Ochil Hills by the 

 north, and there we found the rock to be porphyry slate. On 

 leaving the head of Glenagles, and descending into Glendevon 

 we observed conglomerate lying on grey wacke and transition 

 slate, on the north bank of the river, about three miles above 

 the church. 



The river Devon struck us as flowing all along with uncommon 

 rapidity. It is altogether, perhaps, one of the most singular 

 rivers in Scotland. The rapidity of its fall from its source down the 

 glen till it arrive at the Crook, where, from an easterly, it changes 

 its course to a westerly direction; and then the surprising and very 

 extraordinary phenomena it exhibits at the Devil's Mill, the Hum- 

 bling Bridge, ami Cauldron Lin, are very striking objects. At the 

 mill and the bridge the rock is a hard conglomerate; at the 

 Cauldron Lin it is greenstone. When proceeding from the top 

 of the Cauldron Lin down to the bottom, By the right bank of 



