Lady Mabel now joined them; and L'Isle, pointing out a belt of low woods that wound along the hollow ground at no great distance below them, offered Mrs. Shortridge his arm, and induced her to make an effort to reach its shelter. On drawing nearer to it, they found themselves in a rough path, made by the flocks of the neighborhood, which led them at first through thickets of evergreen shrubs, and then abruptly down the rocky and almost precipitous bank of that stream, which a mile or two below reached and supplied the aqueduct of Elvas. Here the clear, cool waters glided over a rocky bed, and when they had quenched their thirst, the ladies found time to look around. On either hand they were shut in by masses of rock, which, with their stratified and fractured lines, resembled walls, the rude masonry of giants. A projecting crag shut out from sight the stream above them; but, attracted by the sound of falling waters, they pushed their way by a few careful steps round it, and full in view, and close at hand, the stream fell over a ledge of rock in a beautiful cascade, descending at once twenty feet into a rock-girdled pool, which in the course of ages it had hollowed out for itself. Here the water ran eddying round, as lingering on a spot it loved, and loath to resume its onward course. The perpetually falling waters fanned and freshened the noonday air; while overhead, on every ledge that gave footing to their roots, the myrtle and lauristinus, mingled with the oleander, the rhododendron ponticum, and other evergreen shrubs, fed by the fostering moisture of the atmosphere, almost to the size of trees, spread out their luxurious branches to shut out each straggling sunbeam, and deepen the shade of the narrow dell almost to twilight. It was a cavern, with its vaulted roof removed, laying it gently open to the light of day, without its glare. The wood-pigeon amidst the boughs mingled his plaintive notes with the murmur of the falling water, and the speckled trout sported in the pool--now displaying his glistening scales at the surface, then suddenly and coyly hiding in some deep and dark recess. Lady Mabel stood in silent, motionless delight, drinking in with eye, and ear, and breath, the thrilling sensations crowding on her in this enchanted spot. The exclamation in which Mrs. Shortridge's admiring surprise found vent, jarred on her young companions' nerves, and seemed to break a mystic spell.