BOOK III. EXCURSIONS, WITH GEOLOGICAL AND MISCELLANEOUS OBSERVATIONS AND REFLECTIONS. [A number of districts remarkable for certain kinds of natural scenery, or for combinations of different kinds of natural scenery, are here selected, that phenomena considered separately in the preceding book may be viewed in connection. Many districts, some of them, perhaps, as instructive as those here introduced, are necessarily omitted.] I. FROM MINERA TO LLANGOLLEN BY WAY OF THE WORLD'S END-AN EPISODE IN THE GEOLOGICAL HISTORY OF LLANGOLLEN VALE. IN May, 1865, on calling at the office of the Minera Limeworks Company, Mr. Jones, the manager, very obligingly offered to be my guide over the small limestone table-land which lies to the west. This upland plain has been cut into two by denudation, in all probability following the course of a fracture. A brook now flows through the dividing gorge, but as the latter is open at both ends, there is no necessity for supposing the brook to have been the main excavator, more especially as currents must have rushed through this gorge when the marine drift, farther south, was in course of being deposited. On the north side of the gorge, the * table-land presents a rocky floor, with wonderfully regular rows of limestone flags separated by rents. They looked like an immense assemblage of gravestones; and as we proceeded in our examination, we found that they were not without inscriptions of a kind that revealed more eloquently than words the nature of the denuding cause which must have formed this natural cemetery. The inscriptions were not mere random impressions, but regular, smooth, and curvilinear grooves, generally more or less parallel. I believe that waves wielding stones, or ice charged with stones, and moved to and fro by waves, must have been the sculptors employed in fashioning the many thousands of grooves which are here crowded within the narrow compass of a few acres. Before reaching the farther edge of the table-land, I had resolved on walking to Llangollen over the moor, instead of going back to Wrexham, and returning by rail. I soon found that the brook which ran through the gorge did not enter it in a straight line, but, as is common with brooks as well as rivers, made a sudden bend, as if the gorge had diverted it from its previous course. I walked up the channel of the brook in a direction at nearly right angles to that of the gorge, and saw a phenomenon very common in Wales, namely, a brisk stream running down the declivity of the ravine, without having excavated any channel farther than was necessary to contain its waters. Farther on we reached a smaller natural graveyard of sculptured limestone slabs, which was probably at one time much more extensive. The imposing Lower Silurian ridge of Cyrn-y-brain now appeared on the right. On the left and in front, a moor sloped gently towards the west, until it merged into a pass running * See article_by Author in Quart. Journ. Geol. Soc. vol. xxiv. No. 95, p. 277. UNFOUNDED SUSPICIONS. 299 NE. and SW. along the base of Cyrn-y-brain. Our way lay along the south-east side of this pass. The moor soon became more or less boggy, and after parting company with Mr. Jones, I lost my way through trying to travel in a straight line, but this afforded an opportunity of seeing the extraordinary havoc committed by the brook already mentioned in the upper part of its course. An enormous mass of drift was in several places cut down to a great depth. The commencement of the channel of the brook in this drift was well defined. On returning to a solitary miner's cottage, I was directed along a cart road, which eventually led to Llangollen. The limestone rock was buried beneath a covering of fine shingle with a matrix of clay. Many of the pebbles appeared as if they had been very much rolled. Being without a map, and fancying that the cart road was roundabout, I turned to the left, and on walking over a heath-clad eminence, I soon descried the figure of a man at some distance. It turned out to be a shepherd, a Scotchman, who very obligingly conducted me to the World's End. At first I thought he might possibly be an undeveloped Hugh Miller, but as the distance from any house, or any other human being, increased, and I fancied he was leading me in a wrong direction, I became somewhat suspicious, a circumstance I have ever since regretted. But it was about the time when the newspapers were filled with cases of garroting. We passed a deep circular cavity lined with loose stones. Whether they had been thrown in by human hands, or left by eddies in the glacial sea, I had not time to consider. It was probably a swallow hole (a subject on which it is very easy to broach unorthodox ideas, or to be out of the geological fashion), and the Scotchman informed me there were others in the neighbourhood. The thought of the possibility of |