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Proceedings of the Royal Society 
possible that the balls found in the Leith boulder clay form a 
portion of the debris of these pyrites strata so broken up. 
What agent can fit into all these conditions so well, as a sea 
current loaded with ice ? 
On this theory, it is intelligible why the rocks along the moors 
of Craigend and Craigmaddie, stretching for 5 or 6 miles in a 
direction S.E. and S.S.E., at a level of from 500 to 700 feet above 
the sea, should show more effects of grinding and striation than the 
rocks at a lower level. Had a glacier been the agent, the grinding 
would have been chiefly at the lowest, not at the highest levels. 
The subjoined plan and section of Campsie hills and valley will 
make the foregoing explanations more intelligible. The plan is 
copied from a published map by Johnston. The section has been 
Ground Plan of Campsie Yalley. 
A, Pyrites coal strata, out-crop of. 
B, Craigend Moor, 450 feet. 
C, Craigmaddie Moor, 700 feet. 
D, Boulder and striated rocks at Croyhill. 
K, Kilsyth coal strata. 
Boulders shown by black dotts. 
Striae on rocks by arrows. 
FAE, Line of section across Campsie Valley. 
kindly drawn for me by Mr John Young of Glasgow, who is 
thoroughly well acquainted with the geology of the district. In his 
letter sending the section, Mr Young says — “ The Campsie coal and 
limestone is at present worked on the flank of the north hill, as well 
as in the mine which you saw in the south hill. The valley 
