255 
of Edinburgh, Session 1880-81. 
The boulder would he of the shape of a pear, were a horizontal 
section made through its widest part (fig. 5). Its sharpest end 
points S.W. Its height is about 15 feet, and it has three sides 
tolerably flat, each about 15 feet wide. I calculated its weight at 
from 60 to 70 tons. 
Its axis coincides with the general direction of the valley, and 
its sharpest end is towards the sea, creating a presumption that 
something floating up the loch may have put it and left it in that 
position. 
The boulder is nearly opposite to Castle Sweyn, which is on the 
south bank of the loch. There is a rocky knoll about 40 feet above 
the loch on which the castle had been built. On the west side of 
this knoll there is a great number of huge angular boulders, which 
seem to have come from the westward, and been intercepted by the 
knoll in their progress eastwards. The narrowest part of the loch 
is at Castle Sweyn, so that it was the most likely place for an 
obstruction of ice rafts from the west. 
Mr Alexander of Lochgilphead, to whom the Committee are 
indebted for much valuable assistance in giving information about 
boulders on the west coast of Argyle, told me of a cluster of 
boulders on the farm of Taynish, about 4 miles to the south of 
Tayvallich, on Loch Sweyn. There is one large boulder from 9 to 
10 feet high, surrounded by a number of small boulders. They lie 
on a bit of bare rock. The land slopes towards S.W. They are 
about 30 feet above the level of the sea, and distant from it about 
300 yards. 
2 K 
VOL. XI. 
