171 
of Edinburgh, Session 1878-79. 
inches long by 9 broad and 7 thick, but the generality are much 
smaller ” (page 28). 
Referring to this peculiar rock, Professor McoL observes : — 
“ The red sandstone in this district has undergone enormous de- 
nudation. On the shore of Loch Maree it is often broken up into 
huge masses or divided by gaps and fissures, some of them 20 to 
30 feet deep. The surface of the beds is strewed with [immense 
angular and ruin-like blocks, some of them poised on a single 
corner on the very edge of a cliff. All this indicates extensive 
destruction of the strata. Detached fragments of the breccia are 
found in hollows of the gneiss hills, far from the main masses 
evidently left there in the general denudation.” 
Now in what direction were these “ fragments carried,” and from 
what quarter did this “general denudation” — this “enormous 
denudation ” — come 1 
The following facts leave no doubt on the subject : — The smoothed 
surfaces of these breccia rocks face N.W. ; the rough sides are 
towards the S.E. Fragments lie on the surface to the south, 
beyond the line which separates these rocks as a formation 
from the quartzite rocks of Ben Eay. Within the limits of 
the formation, huge masses, weighing hundreds of tons, are 
lying at the north base of cliffs — not having fallen from these 
cliffs, but apparently brought there from the north, and left there, 
in consequence of having been obstructed and arrested by the cliffs 
in their further progress to the south. 
These facts are in entire consistency with the theory of a strong 
ice-laden sea current which flowed from the N.W. The valley now 
occupied by Loch Maree, with mountains on each side exceeding 
1000 feet in height, happens to run N.W. and S.E., so that when 
this district was submerged, a glacial current flowing from a northerly 
point would produce all the effects on these breccia rocks which 
have been described. 
Before passing from the district of Gairloch and Loch Maree, the 
Convener thinks it only due to his friend the late Robert Chambers 
to advert to the observations which he made in districts adjoining 
to the north. He makes this reference, as the facts observed by 
Chambers have a close relation to those which the Convener has 
just been describing. 
