126 Proceedings of the Royal Physical Society. 
XV. The Ancient Lakes of Hdinburgh.. By JAMES BENNIE, 
Geological Survey of Scotland, and THomAs ScorTT, 
F.LS., Naturalist to the Fishery Board of Scotland. 
(Read 17th April 1889.) 
The country round Edinburgh is markedly picturesque 
from the combination of crag and hollow in the more rocky 
parts, and of softly contoured hillocks with wide open spaces 
between them, where boulder clay, the peculiar drift of 
glacial periods, prevails. The crags and hillocks have often 
captivated the attention of the painter and the geologist, 
and their forms have been portrayed and their structure 
described in pictures or. essays which have made them 
famous as illustrations of scenic beauty or geological 
phenomena. ~The crags, consisting chiefly of trap-rocks, 
have been taken as types of volcanic action in open eruptions 
or injections of lava among sedimentary strata, and the 
hillocks, composed chiefly of boulder clay, as typical of ice 
action by ice-sheets or glaciers. The hollows which contain 
lake marls, silts, or peats, have not been so much studied, 
partly because such deposits do not obtrude on general 
observers, and partly because the knowledge to understand 
them is rarer and more special. But in certain moods these 
lake marls, silts, or peats have also an attraction not only 
