From Fly Fishing by Viscount Grey of Fallodon 1899.
After a course of some miles in an open channel, through moor or soft ground, the Cassley enters a narrow gorge about a mile before it gets to the bridge at Rosehall. The pools in this gorge are deep, dark, and interesting to look upon, but only once in April did we see a sign of a fish in these pools; it was a clean fish, but was not in the water, but on a rock at the edge, where no doubt it had been put by an otter, for a piece was eaten out of it. Some way down the gorge is a formidable waterfall, broad and steep, and below it a great pool— a typical Falls pool—and a very fine one for a river of such moderate size. Only in low water and in precociously warm weather do salmon ascend into this pool in April. Occasionally, but not often, we got a fish in it. When fishing is not productive it is pleasant to lie in the warm April sun at the edge of the trees on the top of the high bank on the left-hand side of the river, and to look down upon this pool; for it is a fine, fascinating, and beautiful place.
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From the Falls Pool the river makes a steep and rough descent, its course impeded by great rocks. On the top opportunity to turn to the left in the direction of the quiet Kyle for which it is bound. At this point floods have hollowed out a piece of soft moorland bank on the right side, and have made a large dark pool; but this side of the pool is out of the current and of no use for fishing: except that in very high water a side stream is formed that runs along the right bank, and often gives a fish, when the main stream is a raging torrent. Near the end this pool is narrowed again by a ridge of grey rock that projects from the right bank, and on its upper side stands sheer above or almost overhangs the black water. This ridge was known to us as the “goat rocks,” and came by this name for the following reason. In April 1919 a friend and contemporary was fishing the Cassley with me. At Winchester he had excelled both in cricket and football, but advancing years had cur- tailed his physical activity. When invited by the gillie to go out upon this narrow ridge he flatly refused, saying indignantly, “Do you take me for a goat?”
Nevertheless, it is easy to get on to the neck of the ridge, and not difficult to get along the narrow top to the tip of it, where the angler has just enough footing to be able to stand and to cast. From this point of vantage the tail of the pool fishes best. It is not a pleasant place from which to play a fish: the angler cannot move; the fish comes up into the deep still heart of the pool, and in this a fish has once, at any rate, broken my cast round a hidden rock. In any case the angler must play the salmon, unable to move himself, and standing high and directly above the fish—always, in my opinion, an unsatisfactory position—which puts a great strain upon of one great rock, which stands up high in midstream, grows a Scots fir tree. In a narrow cleft on the bare top of this rock a pine seed must once have germinated and put up a shoot that has become a small sturdy tree. There can be no nutriment for its root except such of its own pine needles or other chance leaves that the wind has blown into the small cleft. There is nothing visible except bare rock to nourish its life. In all the years that I have known the Cassley this tree has held its own. It is stunted in growth and of small stature, but has asserted its right to be a tree. Its needles have a yellowish tinge, as if its complexion were sere from hardship. Drought has not starved it, nor flood overwhelmed it, though in big spates I have seen the spray reach it. It has not thriven, but it has lived, and it stands there on a bare rock, isolated by rushing water, an embodiment of dogged determination to demonstrate its right and power to live, where life seems impossible. Year after year I visited the place expecting to find it dead or gone; but always it was there un- changed and undaunted, and I paid a silent tribute of admiration to its hardihood.
At the end of this steep descent are the lower falls, as formidable to salmon as the upper falls; indeed, one would be disposed to say that both falls were impracticable for salmon but for the fact that salmon do ascend them. For sea trout apparently the falls are impracticable. There is no great wide pool under the lower falls; the water hurries away in a deep narrow channel, with high steep rock on the left side, till this rock terminates abruptly and the river takes immediate the rod. But when the fish is tired and under control, it can be steered into a narrow quiet inlet of water on the downstream side of the rocky ridge, and easily netted by a gillie. Even when alone it is not difficult for the angler to net his own fish; for on the downstream side the ridge, though it is too steep to be climbed, is not sheer, and the angler can slither down to the inlet and net his own fish." ............ Sir Edward Grey, Viscount Grey of Fallodon