eo 
“NI 
D. MILNE HOME ON THE PARALLEL ROADS OF LOCHABER. 6: 
Author’s Views. 
In reference to the phenomena last described, which Messrs JAMIESON and 
JOLLY have sought to explain on Glacier principles, I venture to bronese an 
explanation of a different character. 
It occurs to me to suggest whether these phenomena rather do not indicate 
the action of ice floating in a sea at least 2000 feet above the present sea-level ? 
If Glen Spean then formed a Kyle or submarine valley, the floating ice would 
grate upon the sides of the hills, and plough through the detritus covering 
them, and occasionally form troughs and banks, more or less parallel with the 
valley. The markings on the rocks where the valley is narrow evidently 
indicate some powerful agency, such as an iceberg. At the Bruach Valley, 
where there would be a bay in this ancient sea between Ben Chlinaig on the 
north and the rocks of Meal Laire and Loch Treig on the south, there might 
have been eddies, which would account for the large accumulation there of 
gravel and sand in the form of long embankments. 
Farther east, Glen Spean becomes somewhat more contracted by the pro- 
jecting rocks at Loch Treig on the south side, and the Coinnichte Hill rocks on 
the north side. But beyond that point, it will be observed from the Ordnance 
contour lines * that the valley expands greatly, especially towards the east. A 
current flowing eastward through the narrow part, between Ben Chlinaig and 
Craig Dhu, when it reached the part beyond Inverlair and Loch Treig, would 
become almost stagnant, or form slow eddies. The probability is, that any 
current coming up the valley from Ben Chlinaig would strike on the projecting 
rocks east of Glen Treig, and if there was ice floating in the current it would 
impinge on these rocks and throw down at the foot of the rocks the boulders 
now lying there in heaps. (See p. 641.) 
The foregoing remarks apply to Glen Spean, but similar facts are supplied 
from other adjoining districts. 
In the upper part of Glen Roy there are hard grey granite rocks in the 
middle of the valley, which in my first memoir I noticed as affording evidence 
of some agent which had ground them down to a remarkable smoothness of 
surface. These rocks have been smoothed on their west sides, and are rough on 
their east sides. Had a glacier ever existed in Glen Roy, these rocks would 
have been smoothed on their east sides, and been rough on their west sides. 
This fact favours the theory I have advanced of a sea laden with ice, which, 
besides flowing up through Glen Spean had flowed also up through Glen Roy, 
then a submarine valley. 
In another part of Glen Roy, viz., on the south side, nearly opposite to the 
Gap, and at a height of 1238 feet above the sea, I found rocks with smoothed 
* See Plates XLI. and XLIII. 
