that the hand of man could have had nothing to do with this coal mine; the vault above would have fallen in; as it was, it was only held together by some miracle of nature. This mighty natural cavern was about a hundred feet wide, by about a hundred and fifty high. The earth had evidently been cast apart by some violent subterranean commotion. The mass, giving way to some prodigious upheaving of nature, had split in two, leaving the vast gap into which we inhabitants of the earth had penetrated for the first time.
The whole singular history of the coal period was written on those dark and gloomy walls. A geologist would have been able easily to follow the different phases of its formation. The seams of coal were separated by strata of sandstone, a compact clay, which appeared to be crushed down by the weight from above.
While we still continued our journey, I forgot the length of the road, by giving myself up wholly to these geological considerations. The temperature continued to be very much the same as while we were traveling amid the lava and the schists. On the other hand my sense of smell was much affected by a very powerful odor. I immediately knew that the gallery was filled to overflowing with that dangerous gas the miners call fire-damp, the explosion of which has caused such fearful and terrible accidents, making a hundred widows, and hundreds of orphans in a single hour.
Happily, we were able to illume our progress by means of the Ruhmkorff apparatus. If we had been so rash and imprudent as to explore this gallery, torch in hand, a terrible explosion would have put an end to our travels, simply because no travelers would be left.
Our excursion through this wondrous coal mine in the very bowels of the earth lasted until evening. My uncle was scarcely able to conceal his impatience and dissatisfaction at the road continuing still to advance in a horizontal direction. The darkness, dense and opaque, a few yards in advance and in the rear, rendered it impossible to make out what was the length of the gallery. For myself, I began to believe that it was simply interminable, and would go on in the same manner for months.
Suddenly, however, at six o'clock, we stood in front of a
