The negro and Herbert ran to some pine and evergreens growing upon the bank, and soon returned with branches which were made into torches. Having lit them, the colonists, with Smith leading, entered the dark passage, but recently filled with water. Contrary to their expectation, the passage grew higher as they advanced, until soon they were able to walk upright. The granite walls, worn, by the water, were very slippery, and the party had to look out for falls. They, therefore, fastened themselves together with a cord, like mountain climbers. Fortunately, some granite steps made the descent less perilous. Drops of water, still clinging to the rocks, glistened like stalactites in the torchlight. The engineer looked carefully at this black granite. He could not see a stratum or a flaw. The mass was compact and of fine grain, and the passage must have been coeval with the island. It had not been worn little by little by the constant action of water. Pluto, and not Neptune, had shaped it; and the traces of igneous action were still visible upon its surface. The colonists descended but slowly. They experienced some emotion in thus adventuring into the depths of the earth, in being its first human visitants. No one spoke, but each was busied with his own reflections and the thought occurred to more than one, that perhaps some pulp or other gigantic cephalopod might inhabit the interior cavities which communicated with the sea. It was, therefore, necessary to advance cautiously. Top was ahead of the little troop and they could rely on the dog’s sagacity to give the alarm on occasion. After having descended 100 feet, Smith halted, and the others came up with him. They were standing in a cavern of moderate size. Drops of water fell from the roof, but they did not ooze through the rocks, they were simply the last traces of the torrent which had so long roared through this place, and the air, though humid, emitted no mephitic vapor. “Well, Cyrus,” said Spilett, “here is a retreat sufficiently unknown and hidden in the depths, but it is uninhabitable.” “How, uninhabitable?” asked the sailor. “Why, it is too small and too dark.” “Cannot we make it bigger, blast it out, and make openings for the light and air?” answered Pencroff, who now thought nothing impracticable. “Let us push on,” said Smith. “Perhaps lower down, nature will have spared us this work.” “We are only a third of the way down,” observed Herbert. “But 100 feet,” responded Cyrus; “and it is possible that 100 feet lower—.” “Where is Top?” asked Neb, interrupting his master. They looked about the cavern. The dog was not there.