We slept well that night, wrapped in our coats of bearskin, while sentinels watched lest the Goatskins, despite their losses, might come upon us suddenly, and woke to a morning as bright as I had ever seen. The sun blazed fiercely down and by noontime it became so hot that we sought the shade of the rocks, where we lay panting. There had been a little wind in the morning, but this had died away and the leaves upon the bushes did not move. All the world was still as the dead, and, as the sun dropped toward the west, it seemed to change from golden to almost red. The air became strangely heavy and was hard to breathe. The sky was clear, save where, far to the south and west, a cloud hung low on the horizon. It was lighted from above; but low down, close to what were the waters of the sea, there ran along it a strip of darkness. All was strange and it affected our minds, though very great must be the real danger to alarm such reckless men as we. We had never felt such curious dread before, and became the more fearful because we could not tell the reason of it to ourselves. Then followed what was more alarming. There came a tremor to the ground beneath our feet, as if it were alive, then suddenly it heaved and rocked. Three times this happened swiftly, as we leaped for our weapons and other gear and ran together out into a great open space, to await whatever might come to us, and it was well that we did so! The whole earth suddenly lifted and sank again and the huge rocks beside which we had rested and those above them were heaved upward from their beds and went crashing down the slope of the mountainside, though we escaped them all. At the same time, from the westward, came the sound of such bursting explosion and such thundering and appalling roar as surely man had never heard before! The world above was changing. In a moment, as it seemed, the white cloud in the sky low down to the westward had climbed halfway up the heavens, shining gloriously at its crest, while from its base, climbing even more swiftly and eating up the whiteness as some monster might devour its prey, the black cloud followed. Upward it rushed until it hid the sun, and deep gloom followed the brightness. There came another awful roar to the westward and then another, and then the rocking of the earth grew less. Still the black cloud kept towering and climbing until it overhung us and still rushed on until all the sky was blotted out and we were left in almost utter darkness. Then came what threatened us with sudden death! The heavy air had been given a new quality, a surcharge of sulphurous fumes in which we gasped for life, hiding our heads in our skin cloaks. For some time this lasted, but finally there came some abatement to the suffocation and we breathed more freely.