376 
POPULAR SCIENCE REVIEW. 
not make itself more rapidly and energetically felt. Their 
remoteness may perhaps account for the fact that until the 
year 1817 no systematic description of them, and no scientific 
attempt at an explanation of them, appeared. In that year Dr. 
MaeCulloch, who was then President of the Geological Society, 
presented to that Society a memoir, in which the roads were 
discussed, and regarded as the margins of lakes once embosomed 
in Glen Roy. 
To Dr. MaeCulloch succeeded a man, possibly not so learned 
as a geologist, but obviously fitted by nature to grapple with 
her facts and to put them in their proper setting. I refer to 
Sir Thomas Dick-Lauder, who presented to the Royal Society 
of Edinburgh, on the 2nd of March, 1818, his paper on the 
Parallel Roads of Glen Roy. In looking over the literature of 
this subject, which is now copious, it is interesting to observe 
the differentiation of minds, and to single out those who went 
by a kind of instinct to the core of the question, from those 
who erred in it, or who learnedly occupied themselves with its 
analogies, adjuncts, and details. There is no man, in my 
opinion, connected with the history of the subject, who has 
shown, in relation to it, this spirit of penetration, this force 
of scientific insight, more conspicuously than Sir Thomas Dick- 
Lauder. Two distinct mental processes are involved in its 
Parallel Roads of Glen Rot. 
After a Sketch by Sir Thomas Dick-Lauder. 
