Nevertheless, after this repast each gave way to his own reflections. I wondered what were those of Hans--the man of the extreme north, who was yet gifted with the fatalistic resignation of Oriental character. But the utmost stretch of the imagination would not allow me to realize the truth. As for my individual self, my thoughts had ceased to be anything but memories of the past, and were all connected with that upper world which I never should have left. I saw it all now, the beautiful house in the Konigstrasse, my poor Gretchen, the good Martha; they all passed before my mind like visions of the past. Every time any of the lugubrious groanings which were to be distinguished in the hollows around fell upon my ears, I fancied I heard the distant murmur of the great cities above my head. As for my uncle, always thinking of his science, he examined the nature of the shaft by means of a torch. He closely examined the different strata one above the other, in order to recognize his situation by geological theory. This calculation, or rather this estimation, could by no means be anything but approximate. But a learned man, a philosopher, is nothing if not a philosopher, when he keeps his ideas calm and collected; and certainly the Professor possessed this quality to perfection. I heard him, as I sat in silence, murmuring words of geological science. As I understood his object and his meaning, I could not but interest myself despite my preoccupation in that terrible hour. "Eruptive granite," he said to himself, "we are still in the primitive epoch. But we are going up--going up, still going up. But who knows? Who knows?" Then he still hoped. He felt along the vertical sides of the shaft with his hand, and some few minutes later, he would go on again in the following style: "This is gneiss. This is mica schist--siliceous mineral. Good again; this is the epoch of transition, at all events, we are close to them--and then, and then--" What could the Professor mean? Could he, by any conceivable means, measure the thickness of the crust of the earth suspended above our heads? Did he possess any possible means of making any approximation to this calculation? No. The manometer was wanting, and no summary estimation could take the place of it. And yet, as we progressed, the temperature increased in the most extraordinary degree, and I began to feel as if I were bathed in a hot and burning atmosphere. Never before had I felt anything like it. I could only compare it to the hot vapor from an iron foundry, when the liquid iron is in a state of ebullition and runs over. By degrees, and one after the other, Hans, my uncle, and myself had taken off our coats and waistcoats. They were unbearable. Even the slightest garment was not only uncomfortable, but the cause of extreme suffering. "Are we ascending to a living fire?" I cried; when, to my horror and astonishment, the heat became greater than before.