21 
of Edinburgh, Session 1872-73. 
the same quarter, as if moved into that position by some agent 
which had been flowing past them. These facts seem to indicate 
conclusively, that some powerful agent had passed over this part 
of the earth’s surface, crossing what is now an arm of the sea, the 
Moray Firth, carrying great masses of rock, and dropping them at 
considerable distances. 
“In the counties of Moray and Nairn, the boulders are at all 
heights, from the sea-level close to the shore, up to the height of 
about 500 feet. But in other districts they are to be seen as 
high up as 2500 feet above the sea. Many of them are perched 
on hill-tops, or very near the tops, and many are in such positions 
as to indicate that, whatever was the transporting agent, they 
could not have fallen from any height. These positions are rocky 
hill-sides, where the slope is so considerable that the boulders could 
easily have slid down with a very small amount of force applied. 
“ The angular form of the boulders is also instructive. Thus 
there is one huge cubical block of old conglomerate on the border 
of Nairn with Inverness, called “ Tom Riach,” to which Captain 
White first called attention, each side measuring almost exactly 21 
feet. It lies on nearly horizontal beds of Old Red Sandstone, in a 
wide valley, with no cliff near it. There can be no doubt that this 
boulder, weighing betwixt 600 and 700 tons, must have been brought 
from a great distance — and otherwise than by rolling or pushing, 
because, from the sharpness of its angles, it evidently had undergone 
no friction. There are hundreds of boulders, which, lying on the 
open surface of the country, sometimes on bare rocks, sometimes 
on gravel deposits, give similar proofs that they must have been 
transferred by some agent, without friction. The boulders referred 
to, are generally single ; but there are two districts where they are 
huddled or grouped together in such a way, as to indicate that 
they had been all brought to the spot by one transporting agent 
which went no further in its forward course. One of these places 
is to the south of Inverness, at or near the mouths of two valleys 
which unite at their lower ends. It is just beyond the mouths of 
these two valleys that the boulders occur in enormous numbers, 
composed of rocks existing in the valleys, to the west and north 
west. Another place is Lochaber, where there are long thick 
lines, or trainees, of boulders, forming parts of a semicircle or horse- 
