269 
of Edinburgh, Session 1880 - 81 . 
The rocks about in situ , are Greywacke. The boulder is also 
Greywacke, but much more gritty than any of these rocks in its 
neighbourhood. 
In walking some distance up the valley, at the mouth of which 
the boulder lies, gritty rock, similar to that of the boulder, was met 
with on the slopes of D unlaw Hill. 
(2.) The other boulder lies within a field on the north side of 
C ran wich Water, about half way between the farm of Crossbank and 
Spango Bridge. 
This stone protrudes about 4 feet above the ground, — and is 
nearly rectangular, the breadth of the sides being each about 
2| feet. 
It is a Dolerite, formed of platey augite in large crystals, with 
very little felspar. It has an unusually rough surface. It differs 
from any rocks in the neighbourhood, but resembles the rock of 
three Dolerite dykes which cross the country some miles to the 
north. 
(3.) To try and discover the parent rocks of these boulders, a 
walk was taken along the central ridge of the Lowthers, as well as 
along several of the spurs and valleys stretching on the one hand to 
the Clyde, and on the other to the hfith, but without result. 
To save trouble to future explorers, it may be mentioned that the 
following hills were ascended, viz., Lowther Hill, Green Lowther, 
Dungrain Law, D unlaw, Hawk Wood, Broad Law, Hunt Law, 
Slough Hill, Stoor Hill, Glen Gober Hill, Low Mill Knowe, Clock- 
hill Hill, The Dods. 
Highlands. 
Lor the reason just assigned, the Professor notes in detail the 
various mountains visited, though no boulders were found on them. 
He observes, that had this practice been followed by previous 
geological surveyors, he would probably have been saved many a 
toilsome climb during the last two years. 
But he states an additional reason for indicating the mountains 
where no boulders were discovered. 
From last year’s Beport it will be seen, that he had observed, in 
at least two districts of Argyleshire, distinct “ streams of boulders ” 
while the districts adjoining these streams contained none. 
