"_Monday, 19th._--Proceeding onward into Brecknockshire, we suddenly heard the roar of water where we least expected it, and came on the edge of a deep and woody dell. Entering among the trees, we scrambled onwards after our guide, tumbling and slipping, and jumping, and swinging down the steep sides of the dingle, sometimes in the path of a running torrent, sometimes in the projecting fragments of slate, and sometimes where no path or way at all was visible. The thorns opposed our passage, the boughs dashed the drops in our faces, and stones frequently slipped from beneath our feet into the chasm below, in places where the view fell uninterrupted by the perpendicular sides of the precipices. By the time we had reached the bottom of the dingle, our boots were completely soaked, and so slippery that no reliance could be placed on steps taken in them. We managed, however, very well, and were amply rewarded by the beauty of the fall which now came in view. Before us was a chasm enclosed by high perpendicular and water-worn rocks of slate, from the sides of which sprang a luxuriant vegetation of trees, bushes, and plants. In its bosom was a basin of water, into which fell from above a stream divided into minute drops from the resistance of its deep fall. Here and there lay trunks of trees which had been brought down by the torrent--striking marks of its power--and the rugged bed of shingles and rocky masses further heightened the idea other objects were calculated to give of the force it possessed when swelled by rains. We stepped across the river on a few tottering and slippery stones placed in its bed, and passing beneath the overhanging masses ran round on projecting points, until between the sheet of water and the rock over which it descended; and there we remained some time admiring the scene. Before us was the path of the torrent, after the fine leap which it made in this place; but the abundance of wood hid it ere it had proceeded many yards from the place where it fell. No path was discernible from hence, and we seemed to be enclosed on a spot from whence there was no exit, and where no cry for help could be heard because of the torrent-roar." Yet another passage should be quoted from this journal; a passage descriptive of an ascent of Cader Idris during a thunder-storm. A thunder-storm was, all his life long, one of the most moving things to Faraday. It seemed always to quicken him into new life. [Illustration: CADER IDRIS.]