“Hear me to the end,” the Professor went on with a firm voice. “Whilst you were lying there motionless, I went to examine the conformation of that gallery. It penetrates directly downward, and in a few hours it will bring us to the granite rocks. There we must meet with abundant springs. The nature of the rock assures me of this, and instinct agrees with logic to support my conviction. Now, this is my proposal. When Columbus asked of his ships’ crews for three days more to discover a new world, those crews, disheartened and sick as they were, recognised the justice of the claim, and he discovered America. I am the Columbus of this nether world, and I only ask for one more day. If in a single day I have not met with the water that we want, I swear to you we will return to the surface of the earth.”

In spite of my irritation I was moved with these words, as well as with the violence my uncle was doing to his own wishes in making so hazardous a proposal.

“Well,” I said, “do as you will, and God reward your superhuman energy. You have now but a few hours to tempt fortune. Let us start!”