418 ©. Messrs. W. Phillips and S. Woods on the (Dec. 
tain in being much whiter, and more rugged ; while in the dist- 
- ance, the line of their extended summits 1s more nearly horizon- 
tal than those of any other mountains we had seen; and there 
are still lower ranges, apparently consisting of the same rock, 
running parallel with them towards the sea coast. It is undoubt- 
edly difficult to determine the precise run of these ranges in the 
circumstances under which we viewed them, but we judged by 
the bearing of the compass, that the run of their ridges is in the 
direction nearly of NE and SW ; that is, parallel to the direction 
of the cleavage plane of the slates here and almost every where 
else. 
{In our route to Machynlleth, we crossed Cader Idris, 
descending by Craig y Caie to the Mynfedd Inn ; and being 
aware that itis the intention of Mr. Aikin, ere long, to present to 
the public a detailed account of the geology of this mountain, we 
abstain from more than a general remark or two, viz. that many 
varieties of the rocks prevalent at Moel Shabod appear likewise in 
this mountain, the escarpment of which towards the north con- 
sists of columnar rocks, bearing generally more completely the 
character of greenstone than any rock we have observed on the 
north of that mountain; that on the face of this escarpment are 
visible two or more beds of slates, interstratified with the 
columns of greenstone, the slates resting on the summits of the 
lower columns, while the bases of the upper rest upon the slates; 
that the plane of the slaty cleavage is about at right angles 
to the position of the columns, running NE and SW, and dip- 
ping at about the angle of 68° to the SE. 
In ascending the mountain, we found several impressions of a 
shell differing from those observed on the summit of Snowdon, 
and also from those found near the base of Ben Glog and at 
Moel Shabod, in a rock which is fine-grained, soft, apparently 
composed chiefly of steatite, and perfectly resembling a variety 
occurring at the base of the latter mountain, and in many other 
laces. 
» The road to Machynlleth runs chiefly along narrow vallies 
often bounded by lofty and steep hills. For the first two or 
three miles, their sides, though verdant to the very summits, are 
neither well wooded nor cultivated, and wherever a rock became 
visible, it was always slate, nor did any solid rock appear during 
the whole of the route to Machynlleth, either by the sides of the 
road, or in the form of ridges as heretofore; the stone fences 
are of slate, and the road being composed of the same material, 
is, though hilly, superior to most we had lately travelled. After 
the first two or three miles from the Mynfedd Inn, extensive 
woods of young oaks covered the sides of the mountains often 
nearly or quite to their summits, almost the whole of the way 
to Machynlleth ; while here and there the oak, the ash, and the 
sycamore, were of a considerable size; the appearance on 
either hand forming a perfect contrast to the general scenery of 
