AND QUARTZ DEPOSITS OF ASSYNT. 345 
ever, detailing the results of single excursions, let me attempt 
briefly describing the entire system in the ascending order, from 
the base upwards. 
The gneiss upon which the system rests is exactly the same 
fundamental deposit here that we find it to be in the Highlands 
of Scotland generally. It is of the ordinary mineralogical 
composition, too, and mixed up, as elsewhere, with the usually 
associated rocks and minerals, existing in the character of veins, 
beds, and included masses. It presents, however, a peculiarity 
in the cast of its scenery, — shared also by the gneiss districts 
of Wester Ross, — which renders what I may term its pictorial 
aspect widely different from that of the gneiss of the central 
and eastern Highlands. Our gneiss hills generally are squat, 
truncated, confluent, massive prominences, traversed by wide 
straths, and open glens; and, though imposing often from their 
vast proportions, they are somewhat monotonous when spread 
over a wide tract, from their obtuse and rounded outlines, and 
and from their lack of height in proportion to their great breadth 
of base. Ben Weavis in Ross-shire, that rises to an altitude 
of little more than three thousand feet from a base some five 
or six miles either way, and on whose flat summit another hill 
as tall as itself might be set down, may be regarded as a some- 
what extreme but characteristic specimen of the class. And 
such, over an area of some seven or eight thousand square 
miles, is the ordinary scenic character of our gneiss hills. The 
gneiss hills of Assynt, with those of the adjoining districts, — 
Eddrachilles on the one hand, and Wester Ross on the other, 
—are, on the contrary, not massive, and rarely confluent: they 
never rise more than a few hundred feet in height; they are 
seldom traversed by continuous valleys; and they are extremely 
abrupt and rugged in their outline. Seen from one of their 
summits, the appearance presented is that of a rough cockling 
sea; while in travelling among them, so thickly do they stand to- 
