316 ON THE ANCIENT GRAUWACKE 
He was greatly more exact, however, in his appreciation of 
the mechanical peculiarities of the deposit; and his descrip- 
tion of those strange convolutions of the strata which give to 
the south of Scotland its series of axial lines, and its repeti- 
tions of beds and bands that come ever and anon to the sur- 
face, and continue to render the place of at least its nether 
groups of rock so obscure, is still approvingly referred to by 
our higher geologists. To account for these strange foldings, 
Sir James, in his paper in the “ Transactions of the Royal 
Society of Edinburgh,” on the Vertical Position and Convo- 
lutions of certain Strata, and their relations with Granite, 
broached that theory of lateral pressure applied by some un- 
known force outside the area of the foldings themselves, which 
is still regarded as the best yet originated on this subject; and 
illustrated it by his famous experiments of the bands of vari- 
ously-tinted clays, and the layers of differently-colored cloths, 
which he succeeded in pressing, by the application of lateral 
force, from a horizontal into a convoluted position. His paper 
did not appear in its completed form until the year 1812 ; 
but as his theory had been originated more than twenty years 
previously, when, on visiting, in the company of Dr. Hutton 
and Professor Playfair, a portion of the east coast of Ber- 
wickshire, he found no fewer than “sixteen distinct bend- 
? 
ings of the strata in the course of about six miles,” and as, 
long ere the publication of his view and experiments, they 
were well known to his scientific friends, I refer to them at 
this early stage in my brief sketch of the history of geologi- 
eal discovery in our Scottish Grauwacke. 
Dr. Hutton had described the “ Alphine Schistus” of the 
South of Scotland as belonging to the Primary class of rocks, 
and founded an argument for his theory on the fact that, in 
direct opposition to the belief of geologists regarding the de- 
posits of this special division, they yet do contain fossils. In 
