The eastern branch of the cave, through which the main stream flows, is much larger than the branch above described; it is also easily navigated, as it contains but two reefs and a small number of cliffs. On first ascending the stream, the continually increasing roar of waters announces a considerable waterfall. Enormous masses of stone, piled up by the falling in of the roof, have blocked up and narrowed the bed of the river to fifteen feet, and cause the stream to shoot down in a broad sheet ten feet high. The cataract, madly rushing over the jet-black rocks and casting up flakes of milk-white foam, is very beautiful, and, when brightly illuminated, must produce a truly magical effect. Beyond the cataract the river flows for a short space in an invisible channel, as its waters are completely hidden under rocks. It was no easy task to carry the planks of the dismembered boat over these rugged blocks of stone, but after reconstructing it on the opposite side of the mound, and overcoming the minor obstacles of a couple of reefs, the river was found to flow in a deep channel between steep walls, and a free navigation opened to a distance of at least a league and a half. ‘No description,’ said Dr. Schmidl, ‘can do justice to the fascination of this subterranean voyage. In some parts the roof is adorned with coral-shaped draperies of snow-white stalactites, but generally the walls are mere black, naked stone. Here and there sources gurgle down their sides, and, along with the melancholy trickling of single drops of water from the vault, alone break the silence of the dark interminable cave. The breathless attention we bestowed on the guidance of our boat and on the wonders that surrounded us sealed our lips, and we glided silently along through the dark waters, that now, for the first time since they began to flow, reflected the glare of a torch.’ Throughout the whole distance of 1,140 fathoms beyond the second reef, there is but one landing-place; everywhere else the walls rise precipitously from the water. In some parts the roof descends so low that the explorers were obliged to lie down in the boat and to shove it along by holding to the projections of the vault, which finally left but a few inches’ space above the water, and thus opposed an invincible obstacle to all further progress. In another grotto—called the Piuka Jama—the Poik again flows in the midst of the grandest subterranean scenery. About a league to the north of Adelsberg, the wanderer, after traversing a thicket of underwood, suddenly finds himself on the brink of a yawning precipice, from the bottom of which is heard distinctly the noise of a rushing stream. The walls of the chasm are almost perpendicular, except where a small ravine, overgrown with shrubs, leads to an enormous rock, on which it is possible to stand, and, if perfectly free from giddiness, to look down into the gulf below, where the huge portal of a cave is seen to open.