One of the most startling phenomena, however, results from a perspective view into the cavern, when about midway, or rather less, from its portal. The rocky vista ends in obscurity; but gleams and columns of light burst down, in many places, from the meridian sun, through this “palpable obscure,” so as to produce a wonderful variety of light and shade, as well as of bas-relief, along the fractured walls. While sitting on the rude wooden conduit before alluded to, and meditating on the infernal region upon which I had entered, I was surprised to behold, at a great distance, the figures of human beings, or thin shadows (for I could not tell which), advancing slowly towards me—suspended between Heaven and earth—or, at least, between the vault of the cavern and the torrent of the Tamina, without any apparent pathway to sustain their steps, but seemingly treading in air, like disembodied spirits! While my attention was rivetted on these figures, they suddenly disappeared; and the first impression on my mind was, that they had fallen and perished in the horrible abyss beneath. The painful sensation was soon relieved by the reappearance of the personages in more distinct shapes, and evidently composed of flesh and blood. Again they vanished from my sight; and, to my no small astonishment, I beheld their ghosts or their shadows advancing along the opposite side of the cavern! These, and many other optical illusions, were caused, of course, by the peculiar nature of the locality, and the unequal manner in which the light penetrated from above into this sombre chasm.
Surprise was frequently turned into a sense of danger, when the parties, advancing and retreating, met on this narrow scaffold. The “laws of the road” being different on the Continent from those in Old England, my plan was to screw myself up into the smallest compass, close to the rock, and thus allow passengers to steal by without opposition. We found that comparatively few penetrated to the extremity of the cavern and the source of the Thermæ—the majority being frightened, or finding themselves incapable of bearing the sight of the rapid torrent under their feet, without any solid security against precipitation into the infernal gulf. To the honour of the English ladies, I must say that they explored the source of the waters with the most undaunted courage, and without entertaining a thought of returning from a half-finished tour to the regions below.[40]