672 
Proceedings of the Royal Society 
other places in the West Highlands where there are fresh-water 
lakes close to the sea, formed in like manner. 
With regard to the boulders, it occurred to the Convener, judging 
from their locality and their position, that they had probably been 
floated up Loch Creran, and been then stopped in their further pro- 
gress by the contraction of the valley and the higher level of the land. 
But if they were floated up Loch Creran, from what quarter did 
they come ? It was natural to look to places facing the mouth of 
Loch Creran, if in these places there were mountains composed of 
rocks similar in composition to the boulders. The island of Mull, 
situated to the W.S.W. of Loch Creran, seemed therefore to he one 
locality which might have supplied the boulders, as from Mr Judd’s 
instructive paper on Mull,* describing numerous varieties of granite 
in the mountains of that island, it appeared likely that rocks of 
the same character as the Fasnacloich boulders existed there. With 
the view of testing this idea, the Convener sent specimens of 
the boulders to Professor Judd, who he heard had, during the 
past autumn, spent three months among the Mull mountains, 
and asked him to state whether he recognised the rock composing 
these boulders as being identical with, or at all events similar to, 
any of the Mull rocks ? Professor J udd was so obliging as to respond 
to the application. 
With the Fasnacloich specimens, there went to Professor Judd 
specimens of the rock composing two very large boulders on the 
shore at Appin, which rock the Convener found on examination 
to he the same as that of the Fasnacloich boulders. These Appin 
boulders lie on upturned blue clay slate rocks. Their shape indi- 
cated that they had undergone great friction, in consequence pro- 
bably of being rolled over the sea-bottom by icebergs floating through 
what was then a sea strait, but now the Linnhe Loch, and the 
chain of lakes forming the Caledonian Canal. Sketches of these 
Appin boulders were taken. The largest is!5xllxl0 feet. Both 
boulders are well rounded at the angles. 
Professor Judd’s Beport is in the following terms : — 
“Appin Boulder s, No. 1. — This rock is not a granite, but a rock of 
basic composition. It appears to be a gabbro with some black mica. 
It is very similar in character to the gabbro of Skye, Bum, Ardna- 
* See 1 ‘ Geolog. Society’s Trans. ” 
