189 
of Edinburgh , Session 1878 - 79 . 
Reservoir, at an elevation of 900 feet (H 5). It is a stiff reddish clay, 
full of well rubbed and scratched stones, and differing in no way from 
the boulder clay of the lower districts. The other locality is about 
three miles to the S. W. of this, in the same line of valley between the 
hills, at an elevation of about 1100 feet. It is of the same character 
as the last, but is covered by a great deposit of gravel and boulders, 
which extends across the broad valley between Hare Hill and 
South Black Hill (H. 6). 
Another large deposit of gravel and boulders is at the mouth of 
the broad valley in which the Bonally Pond lies, at an elevation 
also of 1100 feet above the sea. This deposit encloses some very 
large boulders of greenstone (H. 6). 
III. 
The Convener appends ' to the foregoing Notes by Messrs Somervail 
and Henderson , the References by the late Charles Maclaren , 
by Professor Geikie , and Mr Jas. Croll, to Striae and Boidders on 
the Pentlands, as the localities are embraced in the same map. 
1. Mr M‘Laren, in his “ Geology of Pife and the Lothians,” 
states : — 
(1.) “ There are few opportunities of observing ‘ groovings 5 on the 
Pentland Hills. I noticed them, however, at Westwater of Dun- 
syre, on the top of a thick bed of hard sandstone, from which 1 2 or 
14 feet of alluvium had been removed. The dressings pointed 
exactly east and west ; and the evidence was the more satisfactory, 
as the direction of the stream on whose bank the rock was situated, 
and of the valley in which the stream flowed, was south and north. 
They were very distinct, the larger groovings being about 1J inch 
broad, and ^ths of an inch deep. The locality must be 800 or 900 
feet above the sea” (page 294). 
(2.) Travelled blocks are important in two respects: — -first, as 
indicating the action of currents or other transporting agents no 
longer operating; and next , as illustrating changes which have taken 
place subsequently to their deposition in the spots where we find 
them. 
