184 



Further on we arrive at the quarries of Dyffryn Crownan, which I have 

 examined, and did not find a single specimen of any sort, seeming as if they 

 decreased as the range went further west. Dyffryn Crownan is, however, well 

 worth a visit. It is a narrow gorge of horse-shoe shape, above which the lime- 

 stone rocks tower precipitously, and forming one of the most lovely views in 

 South Wales, although it is so remote from any tourist track, that I question 

 whether it is known by fifty people in the county. Geologically it is interesting, 

 as affording the most perfect junction line with the Old Red Sandstone that I 

 ever saw ; so exactly is it marked that a person could almost make a circuit of 

 the gorge, and trace it with a spade. The next section displayed is that of the 

 Rhymney quarries, in the Valley of the Taff Vechan ; followed by the Penydarren 

 quarries to the north of Merthyr ; but as I have not examined any of them, I 

 merely mention them as a guide to anybody who might wish to visit the whole 

 series. 



Retracing our steps to Beaufort from the Trefil, a fine and instructive view 

 is gained. To the north we see, in the horizon, the undulating Silurian hills about 

 Builth and Radnor Forest. To the left the Old Red Sandstone of the Beacons 

 tower up. Right opposite us we have the whole range of the Black Mountains 

 and Pen-cerj'g-calch, with its isolated covering of Grit and Limestone, like that on 

 which we stand. Far in the distance to the north-east, the Malverns show their 

 plutonic heads. That faint smoke in the far east is the Forest of Dean Coal field, 

 once allied to our own. Looking to the south, we are struck with the parallel 

 edges of the Pennant grit, and between us and them the dense smoke points out 

 the site of the busy iron works. If it is very clear, we may see beyond it all the 

 Mountain Limestone of the Mendip range in Somersetshire. Again, I do not know 

 who would be most pleased — the artist or geologist. I think they should always 

 go together, for the scenery that delights the eye is generaUy one of scientific 

 interest. This rule, however, will not apply to the Coal Measures, more particularly 

 to those of Beaufort, which we are now entering. The surface on which we are 

 now standing is a vast slope of MUlstone Grit or Farewell rock, which, by the bye, 

 is wrongly coloured in the Ordnance map, in which a considerable district is 

 marked as Coal Measures, whereas it is Millstone Grit. As a rock, it is here as 

 elsewhere, an excessively hard material, almost destitute of fossil remains. 

 Although the name " Farewell rock " implies to the collier that there is no more 

 coal to be found underneath, that is not the fact, for there are occasional seams, 

 termed Rosser veins, to which I shall more particularly allude. The following 

 section wUl describe the Millstone Grit, in about eighty yards of thickness. 



Sandstone. 



Strong white sandstone. 



Sandstone and argillaceous shale. 



Sandstone. 



Argillaceous shale. 



Coal, 4 in. 



Sandstone and shale beds. 



Coal, I ft. 6 in. 



