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