ROCKS OF SCOTLAND. 329 
and its neighborhood. And they, teo, like the English preci- 
pices, are composed of a Silurian Limestone, rich in fossils. 
Far beneath, however, and in what at first seems an inferior 
position, we see rising among the trees the peculiar groups of 
buildings, with their tall chimneys and long armed engines, 
that indicate a coal-producing district, and mark on a sloping 
hill-side, immediately over a thick wood, a slim column of smoke 
ascending out of the ground, — where one of the seams beneath 
has been burning for years, — like the smoke of some subordi- 
nate volcano. The valley of the Girvan forms a deep and 
very irregular basin, composed of Silurian rocks, but occupied 
for several miles by a small though not unproductive patch of 
the Coal Measures, which abuts unconformably against the 
older deposits, and lies so low in the system as to be overlaid 
by the Mountain Limestone. The explorer, in passing down- 
wards, should strike off to the north from the public road at 
the pleasant village of New Dailly, and rise on the hill-side, 
after crossing the stream and passing the Castle of Dalquhar- 
ran, towards the older rocks, turning first, however, by the way, 
to visit the coal-workings immediately above the Castle, and 
then, a little further on, to examine, in a chance opening among 
the trees, the overlying fossils of the Carboniferous Limestone. 
He would do well, however, if desirous to economize time, and 
make himself sure of seeing all in the district that is worthy 
of being seen, to secure the services of Mr. Alexander M‘Cal- 
lum, the ingenious fossil collector of Girvan, under whose guid- 
ance he will learn more in a day than he could perhaps find 
out for himself in a week. Under the intelligent direction of 
Mr. M‘Callum, whose services Sir Roderick Murchison has 
deemed worthy of special acknowledgment in his paper, I struck 
up from the coal-works and overlying limestone and shale, in 
which well known fossils, such as Productus giganteus and 
Producius Martini, may be detected, and reached the steep 
28* 
