861 
of Edinliirgh, Session 1883 - 84 . 
Convener along coast to north of the Gairloch Hotel, and at all 
heights up to the very summits of the hills, reaching to nearly 
1 000 feet above sea. The late Professor McoPs description of these 
boulders is not inappropriate, when he says that these “ hills about 
Loch Maree and Gairloch are strewed with innumerable fragments 
of red sandstone, perched, like sentinels, in the most exposed and 
perilous positions, on the very edge of some lofty cliff, or on the 
polished summit of domes of gneiss.” These red sandstone boulders 
belong mostly to what has been termed the Cambrian formation, 
reddish-brown sandstone rocks, which exist along the coast towards 
the north, and partially also in the east coast of the Lewis. The 
rocks of the Gairloch Hills are generally gneiss. 
Lithograph JSTo, 40 (Plate X.) represents a granite boulder on 
the edge of a high sea-clifiE facing the west, 747 feet above the sea, 
projecting 2|- feet beyond the edge of the cliff ; having apparently 
been lodged there by some agent which, striking upon the cliff, 
caused the boulder to slide off upon the cliff. 
Lithograph Xo. 41 (Plate X.) represents one of the hills on the 
coast, to the north of the Gairloch Hotel, 585 feet above the sea, with 
two boulders on the west side of its summit. The Convener, on 
ascending the hill to examine the boulders, found that the large 
boulder was 7 feet long by 3.J feet high, and that it projected 2 feet 
beyond the edge of the cliff. As the rock on which it rests slopes 
down towards X.W. at an angle of 15°, the Convener thought there 
would not be much difficulty, by means of a crowbar, in projecting 
it over the cliff altogether. 
Lithograph Xo. 42 (Plate X.) shows the foregoing boulder, with 
the rock it rests on, on a larger scale. This boulder is a blue whinstone, 
the small boulder a red sandstone, and the rock of the hill clay slate. 
Lithograph Xo. 43 (Plate X.) shows a rocky knoll, near the base 
of the same hill, on which a number of true erratics are clustered. 
The uppermost of these (6x5x3 feet) rests on the others, in such 
a position as to show that it had come from the X. W. 
On the hills between Gairloch and Loch Pionn, the position of 
the smoothed rocks, and also of boulders, seemed to indicate a 
movement rather from W.S.W. than from the usual direction of 
X.W. The deflection, the Convener thought, could be accounted 
for by a range of hills there, against which the transporting agent 
may have struck {Fifth Report^ p. 56), 
