124 
Proceedings of the Royal Society 
knoll, it was found that those which were uppermost must have 
come from the N.W., otherwise they could not have got into the 
positions they occupy. 
There were no boulders near the top of the knoll on the S.E. 
side ; but at the base of the knoll on that side, several boulders were 
lying, which might have fallen from the top. They were not heaped 
on one another, as they were at the top of the knoll, but lying 
separate. 
2. About 200 yards to the 1ST.E. of the big boulder there is a 
boulder on smoothed rock which dips due north at an angle of 
20°. The size of the boulder is 5 x 4 x 4 feet. The steepness of 
the rock surface on which it lies, is so great, that it would have a 
better chance of obtaining and retaining its position by coming from 
the north, than from any other quarter. 
3. About 300 yards to the S.E. of the “ big boulder ” there is a 
boulder 8| x 6 x 5 feet, at a height of about 228 feet above the 
sea, shown on fig. 10. The boulder at its east end presses closely on 
a rock, which has prevented it moving further in an easterly 
direction. 
4. On the N.W. side of Ben Erival, where its sides slope down 
steeply to the sea, there are numerous boulders, and many of them 
pressing in like manner against the rocks of the hill, in such a 
way as to show that they must have come from some point between 
west and north. They are at various heights, from 400 to 500 feet 
above the sea. 
5. There is a low hill to the N.N.W. of Ben Erival, adjoining 
“ Traigli Voref or Great Strand (a narrow neck of sand which here 
separates the east and west shores), through part of which an open 
fissure in the solid rocks runs for some distance. It has evidently 
been one of those rents alluded to by Macculloch in his Account of 
Barra, which had once been filled by trap, but “ of which the ex- 
posed portions have been washed out.” (Yol. i. p. 89.) 
The height above the sea-level is about 120 feet. 
j 
Eor about 80 yards, this rent or fissure now presents two vertical 
walls of gneiss, from 11 to 12 yards apart, and from 8 to 14 feet 
high. 
The direction of the rent is (by compass) N.W. and S.E. The 
rocks on the north wall are rounded, and in many places present 
