Towards morning the ascending movement became accelerated. If the heat increased, instead of diminishing, as we approached nearer to the surface of the globe, this effect was due to local causes alone, and those volcanic. The manner of our locomotion left no doubt in my mind. An enormous force, a force of hundreds of atmospheres, generated by the extreme pressure of confined vapours, was driving us irresistibly forward. But to what numberless dangers it exposed us!
Soon lurid lights began to penetrate the vertical gallery which widened as we went up. Right and left I could see deep channels, like huge tunnels, out of which escaped dense volumes of smoke; tongues of fire lapped the walls, which crackled and sputtered under the intense heat.
“See, see, my uncle!” I cried.
“Well, those are only sulphurous flames and vapours, which one must expect to see in an eruption. They are quite natural.”
“But suppose they should wrap us round.”
“But they won’t wrap us round.”
“But we shall be stifled.”
“We shall not be stifled at all. The gallery is widening, and if it becomes necessary, we shall abandon the raft, and creep into a crevice.”
“But the water—the rising water?”
“There is no more water, Axel; only a lava paste, which is bearing us up on its surface to the top of the crater.”
The liquid column had indeed disappeared, to give place to dense and still boiling eruptive matter of all kinds. The temperature was becoming unbearable. A thermometer exposed to this atmosphere would have marked 150°. The perspiration streamed from my body. But for the rapidity of our ascent we should have been suffocated.
But the Professor gave up his idea of abandoning the raft, and it was well he did. However roughly joined together, those planks afforded us a firmer support than we could have found anywhere else.
About eight in the morning a new incident occurred. The upward movement ceased. The raft lay motionless.
“What is this?” I asked, shaken by this sudden stoppage as if by a shock.
“It is a halt,” replied my uncle.
“Is the eruption checked?” I asked.
“I hope not.”
I rose, and tried to look around me. Perhaps the raft itself, stopped in its course by a projection, was staying the volcanic torrent. If this were the case we should have to release it as soon as possible.
But it was not so. The blast of ashes, scoriae, and rubbish had ceased to rise.
“Has the eruption stopped?” I cried.
“Ah!” said my uncle between his clenched teeth, “you are afraid. But don’t alarm yourself—this lull cannot last long. It has lasted now five minutes, and in a short time we shall resume our journey to the mouth of the crater.”
As he spoke, the Professor continued to consult his chronometer, and he was again right in his prognostications. The raft was soon hurried and driven forward with a rapid but irregular movement, which lasted about ten minutes, and then stopped again.
“Very good,” said my uncle; “in ten minutes more we shall be off again, for our present business lies with an intermittent volcano. It gives us time now and then to take breath.”
This was perfectly true. When the ten minutes were over we started off again with renewed and increased speed. We were obliged to lay fast hold of the planks of the raft, not to be thrown off. Then again the paroxysm was over.
I have since reflected upon this singular phenomenon without being able to explain it. At any rate it was clear that we were not in the main shaft of the volcano, but in a lateral gallery where there were felt recurrent tunes of reaction.
How often this operation was repeated I cannot say. All I know is, that at each fresh impulse we were hurled forward with a greatly increased force, and we seemed as if we were mere projectiles. During the short halts we were stifled with the heat; whilst we were being projected forward the hot air almost stopped my breath. I thought for a moment how delightful it would be to find myself carried suddenly into the arctic regions, with a cold 30° below the freezing point. My overheated brain conjured up visions of white plains of cool snow, where I might roll and allay my feverish heat. Little by little my brain, weakened by so many constantly repeated shocks, seemed to be giving way altogether. But for the strong arm of Hans I should more than once have had my head broken against the granite roof of our burning dungeon.
I have therefore no exact recollection of what took place during the following hours. I have a confused impression left of continuous explosions, loud detonations, a general shaking of the rocks all around us, and of a spinning movement with which our raft was once whirled helplessly round. It rocked upon the lava torrent, amidst a dense fall of ashes. Snorting flames darted their fiery tongues at us. There were wild, fierce puffs of stormy wind from below, resembling the blasts of vast iron furnaces blowing all at one time; and I caught a glimpse of the figure of Hans lighted up by the fire; and all the feeling I had left was just what I imagine must be the feeling of an unhappy criminal doomed to be blown away alive from the mouth of a cannon, just before the trigger is pulled, and the
