614 Proceedings of the Royal Society 
which the boulders near Tulla had been carried about ten miles in a 
direction E.S.E. 
As it was thought desirable to see whether these boulders could 
be traced farther to the eastward, I tracked them back to the west 
and north shores of the lake, and thereafter for 2 or 3 miles up the 
course of the water of Tulla. They evidently diminished in numbers 
towards the east. Some of the boulders at Loch Tulla were about 
8 cubic feet in size. 
A search was next made along the southern range of hills, of 
which Meal Buidh, Ben Creachan, and Ben Achallater are the 
highest. But no boulders of the same or of any kind were found 
on them. 
These boulders, therefore, had been carried, as it were, in a stream, 
and one of no great width, towards the S.E. 
The valley, which gradually ascends westward from Loch Tulla 
towards the great massive hill of Starrav, becomes very narrow im- 
mediately to the east of Loch Dochard. 
If any powerful agent passed through this valley eastward, it is 
probable that there would be great obstruction and a violent pressure 
on and rending of the adjoining rocks. 
The lower part of the pass contains much till, and occasionally 
rock rises up through the till with finely smoothed hunches, showing 
striations from the W.N.W. 
On the south side of the lake there are some enormous boulders, 
mostly angular, several of which are broken or fractured, as if by 
falling from a height. A sketch is given of one of these, fig. 7 on 
plate XVIII., as it is the largest I have seen or heard of in Scotland, 
except one in Arran. Its size is 45x22x26 feet, and amounting 
therefore in weight to about 1900 tons. It consists of mica gneiss, 
and lies upon till. The view in the figure is taken from X.N.W. 
Other boulders of a similar rock occur at the same place, nearly 
equally large. 
The hill immediately to the south of this boulder is composed of 
a similar sort of rock; so that very possibly, nay probably, the 
boulder may have been detached from the hill. But it is so far from 
the hill, and the intervening ground is of such a nature, that nothing 
but ice could have brought it into its present position. 
The rocks at this place are much rounded, and show striae running 
