All at once they descried below them a peculiar sight. As far as they could see, there were piled up hundreds of miles of rocks, the _bases_ lit with a peculiar haze, or glow, which came from the ground itself like a giant _ignis fatuus_, or ‘will-o’-the-wisp,’ the origin of which is, even to-day, a mystery to science, and though many explanations have been attempted, none are conclusive, or even tenable. Then numbers of these flashing lights appeared, as though a multitude of people were carrying huge candles or lanterns, some of the lights being blue, others greenish and yellow, but the majority purple, and all these flitted in and out and about the bases of the hills, and clambered up and rested on peak after peak in the most ghostly manner imaginable. Then all was dark again. The ground heaved and split, and the ‘marsh gas,’ the colliers’ ‘fire-damp’ (evolved during the process of decomposition of the dead and dying vegetable matter in the ground and in the changes taking place while coal was being formed), had found a means of outlet through the opening, and, mixing with the air, formed the well-known explosive mixture which, with an awful though silent disruption, laid low hill after hill, and a few seconds later what had been a range of mountains became a desolate plain. The ship was made in equipoise, and in complete amazement, all watched the surface of the world below them change its shape and configuration every few minutes—it was in constant fret, and though not losing its shape as a whole, yet valleys were turned into hills and mountains into deserts with an awfulness which the darkness and silence rendered even more frightful. All would be dark—black; then from point to point in the distance the light would come again, roving here and there like a lost spirit fruitlessly searching in a desolate world for its soul, and would run up the rocks in a gliding flow, hanging for a few moments on dizzy pinnacles, and then, in apparent despair, precipitate itself headlong, or wash itself down the steep sides like an avalanche of sliding snow; perhaps, when half-way down, suddenly to stop and take a fresh movement, spreading and stretching itself like a flickering, elastic web, embracing hill after hill in its toils, till the whole horizon was covered with it, and there lay below them a snowy world, with every summit frowning and black by contrast, showing above it as though impaled. A second later the whole landscape, shuddering under its cloak, would shake itself and the light suddenly vanish, leaving black darkness again everywhere. The _Regina’s_ search-lights were switched off, and the whole vessel plunged in darkness, so that the occupants could better examine the strange world below them as they crowded round all the windows, intently watching through their glasses.