All that we have to do is follow it, and sooner or later we shall come upon its source."We were already rather close in; but I ordered the U-33's prow turned inshore and we crept slowly along, constantly dipping up the water and tasting it to assure ourselves that we didn't get outside the fresh-water current. There was a very light off-shore wind and scarcely any breakers, so that the approach to the shore was continued without finding bottom; yet though we were already quite close, we saw no indication of any indention in the coast from which even a tiny brooklet might issue, and certainly no mouth of a large river such as this must necessarily be to freshen the ocean even two hundred yards from shore. The tide was running out, and this, together with the strong flow of the freshwater current, would have prevented our going against the cliffs even had we not been under power; as it was we had to buck the combined forces in order to hold our position at all. We came up to within twenty-five feet of the sheer wall, which loomed high above us.
There was no break in its forbidding face. As we watched the face of the waters and searched the cliff's high face, Olson suggested that the fresh water might come from a submarine geyser. This, he said, would account for its heat; but even as he spoke a bush, covered thickly with leaves and flowers, bubbled to the surface and floated off astern.
"Flowering shrubs don't thrive in the subterranean caverns from which geysers spring," suggested Bradley.
Olson shook his head. "It beats me," he said.
"I've got it!" I exclaimed suddenly. "Look there!" And I pointed at the base of the cliff ahead of us, which the receding tide was gradually exposing to our view. They all looked, and all saw what I had seen--the top of a dark opening in the rock, through which water was pouring out into the sea. "It's the subterranean channel of an inland river," I cried. "It flows through a land covered with vegetation--and therefore a land upon which the sun shines. No subterranean caverns produce any order of plant life even remotely resembling what we have seen disgorged by this river. Beyond those cliffs lie fertile lands and fresh water--perhaps, game!""Yis, sir," said Olson, "behoind the cliffs! Ye spoke a true word, sir--behoind!"Bradley laughed--a rather sorry laugh, though. "You might as well call our attention to the fact, sir," he said, "that science has indicated that there is fresh water and vegetation on Mars.""Not at all," I rejoined. "A U-boat isn't constructed to navigate space, but it is designed to travel below the surface of the water.""You'd be after sailin' into that blank pocket?" asked Olson.
"I would, Olson," I replied. "We haven't one chance for life in a hundred thousand if we don't find food and water upon Caprona.
This water coming out of the cliff is not salt; but neither is it fit to drink, though each of us has drunk. It is fair to assume that inland the river is fed by pure streams, that there are fruits and herbs and game. Shall we lie out here and die of thirst and starvation with a land of plenty possibly only a few hundred yards away? We have the means for navigating a subterranean river. Are we too cowardly to utilize this means?""Be afther goin' to it," said Olson.
"I'm willing to see it through," agreed Bradley.
"Then under the bottom, wi' the best o' luck an' give 'em hell!"cried a young fellow who had been in the trenches.
"To the diving-stations!" I commanded, and in less than a minute the deck was deserted, the conning-tower covers had slammed to and the U-33 was submerging--possibly for the last time. I know that I had this feeling, and I think that most of the others did.
As we went down, I sat in the tower with the searchlight projecting its seemingly feeble rays ahead. We submerged very slowly and without headway more than sufficient to keep her nose in the right direction, and as we went down, I saw outlined ahead of us the black opening in the great cliff. It was an opening that would have admitted a half-dozen U-boats at one and the same time, roughly cylindrical in contour--and dark as the pit of perdition.
As I gave the command which sent the U-33 slowly ahead, I could not but feel a certain uncanny presentiment of evil. Where were we going? What lay at the end of this great sewer? Had we bidden farewell forever to the sunlight and life, or were there before us dangers even greater than those which we now faced? I tried to keep my mind from vain imagining by calling everything which Iobserved to the eager ears below. I was the eyes of the whole company, and I did my best not to fail them. We had advanced a hundred yards, perhaps, when our first danger confronted us.
Just ahead was a sharp right-angle turn in the tunnel. I could see the river's flotsam hurtling against the rocky wall upon the left as it was driven on by the mighty current, and I feared for the safety of the U-33 in making so sharp a turn under such adverse conditions; but there was nothing for it but to try.
I didn't warn my fellows of the danger--it could have but caused them useless apprehension, for if we were to be smashed against the rocky wall, no power on earth could avert the quick end that would come to us. I gave the command full speed ahead and went charging toward the menace. I was forced to approach the dangerous left-hand wall in order to make the turn, and Idepended upon the power of the motors to carry us through the surging waters in safety. Well, we made it; but it was a narrow squeak. As we swung around, the full force of the current caught us and drove the stern against the rocks; there was a thud which sent a tremor through the whole craft, and then a moment of nasty grinding as the steel hull scraped the rock wall. I expected momentarily the inrush of waters that would seal our doom; but presently from below came the welcome word that all was well.
