18 13.] made in the Highlands of Scotland. 29 



Callander ; but this, I am sorry to say, was not done in the 

 manner I could have wished, having been deceived by the expec- 

 tation of meeting with enough of conglomerate for that purpose 

 next day on our way to Loch Catherine. In as far, however, as 

 I did examine the nodules, 1 found them to consist principally of 

 white quartz ; but met also with a few nodules of clay slate and 

 hornstoue porphyry. 



In the evening of the 16th we visited the fine fall at Brarklin 

 bridge, about a mile to the east of Callander. The rock is 

 conglomerate, and broken down by the action of the water into 

 many fine and fantastic forms. We had the conglomerate all 

 along from Callander to this fall; and on tracing the river about 

 two miles up observed no other rock : but Mr. Jardine told me 

 that some time ago Sir James Hall found grey vvacke about a 

 mile or two higher up than wc were. Night prevented our 

 reaching it. 



The grey wacke and grey wacke slate appear about two miles 

 after leaving Callander, on the road to Loch Catherine. They 

 continue all along the valley of Loch Vena< liar and Loch 

 Achray to the Trossacks, and the eastern part of these hills is 

 composed of grey wacke. The western part, next to Loch 

 Catherine, is mica slate; and this is the rock all along the banks 

 of the lake to its top. The Lady's Isle, rendered now so famous 

 by the poetry of Mr. Scott, is a roundish mass of mica slate, 

 about 100 yards diameter, projecting finely from the surface of 

 the water, and covered with wood. On the Isle of I'ontenellan, 

 very near the head of the lake, we found a large rolled mass 

 (about two feet diameter) of very beautiful primitive greenstone ; 

 but saw no rock in situ except the mica slate. 



About half way between Callander and the Trossacks, that is, 

 five miles from each, is a quarry of clay slate. It is on the 

 right hand of the road as we go toward the Trossacks, on the 

 banks of Loch Venachar, and 100 feet at least above the level 

 of the lake. I examined it; but could not see the junction of 

 this slate with the grey wacke or the mica slate. The strata are 

 highly inclined, between 70° and 80°, and dip towards the hill. 

 Having no compass (as wc had unfortunately brought one with 

 us which was good for nothing) I could not ascertain their direc- 

 tion, but it is somewhere between E. and N. E. 

 _ At Stewart's House, two miles from the foot of Loch Cathe- 

 rine, wc have the grey wacke; and about 1 :>0 yards up the hill, 

 towards the N. in the bed cf the rivulet, appears slate which I 

 to'jk to be transition. The hill rises rapidly, and m less than 

 100 yards more we have the mica slate. 



On leaving Stewart's wc proceeded over tin' hills to the head of 

 Look Lubnaig, a walk of nine miles. In this route we crossed 

 Gleofinlasc, the mica state formation accompanying us all the 

 4 



