GREAT GLEN OF SCOTLAND. 
199 
The grains of this granite, which are red, depending on 
the felspar, vary in size from small to very fine, even to 
microscopic; and when the rock occurs in this latter state, 
it might easily be confounded with sandstone. One hill, 
in fact, not far from Dochfour, which presents a red, crum- 
bling declivity, might apparently be described as composed 
of red sandstone. An examination, however, of the rock 
in its original position would soon disprove this fallacy. 
After passing Maulfourvoney, this granite, which occupies 
the whole of this chain, at least on the side next Loch Ness, 
gives place to gneiss, which continues as the prevailing rock 
to Fort Augustus, and from thence all the way to the op- 
posite shore of Lochaber. 
The strata of the granite seem not to be very regular as 
to inclination and bearing, but their alternations with gneiss 
are frequent and distinct. Whether this rock is itself to 
be considered as a mere variety of gneiss, I have not yet 
sufficiently determined. As far, however, as ray partial 
observation has gone, I have observed little of the slaty 
structure characteristic of gneiss; but, on the contrary, 
have almost always found the masses of these strata to be 
quite compact, and destitute of every appearance of regu- 
larity or alternation of the ingredients 
Their hardness and compactness, in fact, seem to make 
them well adapted for building ; and they have, I believe, 
been accordingly used in the construction of the locks of 
the Canal at Fort Augustus. 
This mountain range, which may be considered as com- 
posed of granite and gneiss, also contains beds of granular 
foliated limestone, which are situated in the gneiss. The 
best known beds are those in Glen Urquhart. These beds 
* Professor Jameson, I believe, considers the rock of this district as 
gneiss. 
