We had nothing to fear either from savages or from wild beasts.
After a night's sweet repose, we awoke fresh and ready for action. There being nothing to detain us, we started on our journey. We continued to burrow through the lava tunnel as before. It was impossible to make out through what soil we were making way. The tunnel, moreover, instead of going down into the bowels of the earth, became absolutely horizontal.
I even thought, after some examination, that we were actually tending upwards. About ten o'clock in the day this state of things became so clear that, finding the change very fatiguing, I was obliged to slacken my pace and finally come to a halt.
"Well," said the Professor quickly, "what is the matter?"
"The fact is, I am dreadfully tired," was my earnest reply.
"What,"
