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Tudalen:Traethawd ar Gaio a i hynafiaethau.djvu/45

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majority of the workings, extending to a considerable depth for some acres over the side of the hill, are open to the day, or worked as usual in the early days of mining, like a quarry, and the rock through which the lodes run, a portion of the lower silurian rocks, is in many cases exposed, and exhibits beds much contorted and broken, though having a general tendency to dip northward. Here and there a sort of cave has been opened on some of the quartz veins, and in some cases has been pushed on as a gallery, of the dimensions of the present day, viz. 6 or 7 feet high, and 5 or 6 feet wide; and among these, two of the most remarkable are kept clear by Mr. Johnes, and, being easily accessible, allow of close examination. The upper surface of the hill is at this, the south-western extremity of the workings, deeply marked by a trench running north-east and south-west, similar to the excavations technically called open casts, where the upper portion of the lodes were in very early times worked away; and when it was afterwards found disadvantageous to pursue the lode in this manner, a more energetic and experienced mind must have suggested the plan of driving adit levels from the north face of the hill through the barren rock, in order to cut the lode at a greater depth than it could be otherwise reached; and the perseverance in driving 170 feet through the slate, in each of the levels in question, was no doubt based on a sufficient knowledge of the continuous nature of the mineral lode."

"Subsequently follows a parallel between the Gogovau and the extraordinary hill called Cstate, at Verespatal, in Transylvannia, within the confines of Dacia Ulterior, where the grand arches and roomy tunnels, wrought in hard sandstone and porphyry,