1817.] to the Giant’s Causeway. 119 
the Isle of Man, to some miles beyond Creetoun, is esteemed one 
of the most beautiful and interesting in the kingdom. On the right 
towers the lofty granite mountain of Cairnsmuir, but no part of the 
granite reaches the high road. In the greywacke formation, a few 
miles to the east of Newton Stewart, and only three or four miles 
from the granite of Cairnsmuir, were formerly worked pretty ex- 
tensive lead-mines. ‘They have now, however, for some years been 
abandoned. It is the opinion of the best mineralogists that the 
galena veins found here are a continuation of those so extensively 
wrought at Leadhills and Wanlockhead. They are, I believe, found 
to run in the same direction, and they are in the same kind of rock. 
The county of Wigton presents altogether a flat uninteresting ap- 
pearance, and is, so far as ] know, all transition. As I already 
hinted, the transition rocks appear in high cliffs and rugged beauty) 
at the harbour of Port Patrick ; and on arriving in Ireland, I found 
them to accompany me for about eight miles on the road from, 
Donaghadee to Belfast. The county then becomes trap. The rock 
appeared to me to be a variety of porous ill-formed clink-stone or 
tuff, loose in its texture, and of a greyish or iron-black colour. 
At the town of Belfast this formation still continues, where the 
flourishing city of 30,000 inhabitants, the river, the bridge of 21 
arches, the bay, the shipping, the rich county of Down extending 
almost as far as the eye can reach to the east, and the perhaps still 
richer county of Antrim stretching along the north-west shore of 
the bay by Carrickfergus on the north, the Black and Cave moun- 
tains rising to the height of Arthur’s Seat or so, to the west, form 
a picture which, to my imagination at least, is not easily surpassed, 
The Black and Cave hills to the west of Belfast are composed of 
green-stone, basalt, or tuff. In these trap rocks there is an im- 
mense bed of greyish-white indurated chalk, or conchoidal lime-_ 
stone. Above this bed, which is worked in various parts, reposes 
some hundred feet of the trap; and in the lime-stone or chalk are 
numerous and large nodules of grey flint. Some of the flint nodules 
are of a cochineal-red, extremely beautiful. Between the lime- 
stone and the green-stone, and in so far as 1 had the opportunity of 
observing on the lower side of the former, is a rock commonly 
called mulatto-stone, of alight grey speckled colour, and which 
seems to be lime-stone mixed with particles of the trap. On this 
trap, at the bottom of the hill, between it and the town, rests a 
vast bed of clay; and in the bed, where it is intersected by a 
rivulet to a considerable depth, I had the opportunity of observing 
and picking up some fine specimens, from numerous veins, of 
foliated and fibrous gypsum. ‘These veins are seen to ran princi- 
pally, I think, in a northerly and southerly direction, and to dip 
towards the east. I observed them from an inch toa foot or more 
thick. 
Leaving Belfast, I pursued my way to the Giant’s Causeway, by 
Antrim, Ballymoney, and Coleraine (60 English miles), The for- 
mation all along this track is the newest floetz trap. I could observe 
