Welsh Journals

overlying ground, the valley is pitted by many hollows varying from a few feet to many yards across like Lower Daw Pit, and many other pits in the district originated by subsidence in this manner, as for example, High Daw Pit and Gwynspark Pit. In contrast, the whole character of the valley changes and opens out once the river emerges permanently to the surface. The river meanders across a wide, flat, even, valley floor covered by a layer of fine deposits which conceal the solid rock and show that the river is no longer cutting downwards at any appreciable rate. Here the gradient is very gentle, falling less than 50 feet throughout the rest of the course to the sea. The valley sides remain fairly steep owing to the strong, massive nature of the limestone but even they are less precipitous than the cliffs higher up in the dry course. Moreover, they are wider apart, having retreated as boulders falling down from the cliffs have been broken up by weathering action and have been carried away to the sea by the river which is able to keep its valley clear. It has been said that, Land forms are seen in their true significance only if it be remembered that they have developed, and are developing." It is possible, in walking down the Bishopston Valley, not only to reconstruct some of the events in the history of its past development, as we have already seen, but also to look forward and gain some picture of the future development of the valley. This requires no idle flights of fancy if we assume that our understanding of the present develop- ment of the river is a satisfactory working hypothesis, for these same processes will continue to operate so long as the conditions remain unaltered. It is possible therefore to imagine (if the climate and sea- level remain unchanged) the river continuing to develop in much the same way as it has done so far. The lower section of the valley with its permanent river flowing across a wide gently sloping floor will extend gradually upstream as the river slowly cuts back where it finally emerges to the surface. As more debris is carried to the sea, so the valley sides will also retreat, while upstream the sporadic overflow wears away the valley slightly and continued collapse of the floor helps prepare for the attack of headward erosion by the river establishing a permanent course along its whole length. It is not likely that any appreciable change will become visible in our lifetime, as, according to recent calculations, it is well over a million years since the river first began to flow across the emerging aea floor. Gillian E. Groom. DEATH COMING ON THE HILLS When I was a child, I knew a fairy-tale which attracted me above all others. Nor has its attraction palled with the years. Indeed, now that I am older, I am strengthened, revived, bidden to go on by this story of the imperfection of perfection.