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of Edinburgh, Session 1875 - 76 . 
large blocks. Some of these were of sandstone, weighing 10 or 
12 tons, and appeared to be of the same rock as that worked at 
Granton and Craigleith Quarries to the westward. Beneath the 
boulder clay, there was found what the engineers call a “running 
sand ” lying over strata of shale and sandstone. 
Before concluding, the Committee may advert to the circumstance 
that a part of the district comprehended in this Report was. many 
years ago described by an eminent Scotch geologist — the late Charles 
M‘Laren — and with reference to the very matters embraced in this 
report. Mr M‘Laren read papers in this Society, in the years 
1846-47, describing the boulders then existing on the shores of 
the Gairloch, and on the hills between that loch and Lochlong. 
Even then the destruction of boulders in that quarter had begun, 
being appropriated, as Mr McLaren states, to building purposes ; 
and probably by this time they have all been annihilated. 
Mr M‘Laren in these papers described also the striation and 
smoothings of the rocks, which he found from the sea-shore 
up to the tops of the ridges, between the Gairloch and Lochlong, 
at heights of about 1000 feet above the sea. It is due alike to 
the memory of our Associate, and to the interests of geological 
science, to mention, that the boulders referred to by him, as 
found on the Gairloch, consisted of grey granite, of which he 
counted above a hundred, one-third of them exceeding 30 tons in 
weight; as also mica slate, which, though less numerous, had 
had among them blocks of 60 and 80 tons in weight. As 
the rocks of the Gairloch in situ , are of a more recent kind — viz. 
clay slate-— Mr M'Laren justly inferred that the boulders were of 
northern origin. For those of granite, he pointed to Ben Cruachan, 
a mountain exceeding 3000 feet in height, situated to the N.N.W., 
and distant about thirty miles. The mica slate hills are also in 
the same direction, somewhat more distant. From his study of the 
boulders and other phenomena in this district, Mr McLaren drew 
two important conclusions. One conclusion was, that the boulders 
must have been brought to the district from the parent moun- 
tains, across valleys and ranges of hills, on ice floating on a sea 
which stood from 1500 to 2000 feet above the present sea-level, and 
in which a strong current had prevailed from the N.W. This con- 
clusion, it will be noticed, is confirmed by the facts specified in the 
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