J26 ON THE HIGHLANDS. 



section of the internal structure of* Ben -Nevis, 

 The precipice itself consists almost wholly of 

 the dark- coloured rock ; which, above the wedge- 

 shaped mass now described, appears to spread it- 

 self horizontally over the subjacent reddish felspar. 



The rocks on which the entire mass of Ben- 

 Nevis rests, are Gneiss ; and Mica-slate, in some 

 places approaching to clay-slate. These, at dif- 

 ferent points of the base, may be seen distinctly 

 running beneath the body of the mountain, in the 

 usual direction of the Highland strata. For ex- 

 ample, on the level ground between Fort William 

 and the beginning of the ascent, mica-slate is to be 

 traced, passing under the north west corner of the 

 base, and appearing beyond it, in the channels of 

 the rivulets which descend on that side. Along 

 the course of the Nevis also, the strata are ob- 

 served in many places, crossing the bed, and run- 

 ning directly under the mountain. Nearly op- 

 posite to Glen-Nevis house, I found the junction 

 with the superincumbent formation, in the bed of 

 a small rivulet, where the debris of the higher 

 rocks begin to cover the soil of the glen ; and a 

 little to the north, on the same side, a considerable 

 front of mica-slate presents itself, at some height 

 above the river. At last, however, after ascend- 

 ing to a considerable elevation, the strata forming 

 this front, disappear beneath the mass of the 

 mountain-base. 



This general view of the structure of Ben-Nevis 

 is illustrated by a reference, on the grand geognos- 

 tic scale, to the nature of the adjoining country. 



