sky at night. I was afraid to move, for fear I should tumble into
astronomical distances."

The captain stared about him, apparently as much confounded by the
situation as was the boy. But his mind was quickly brought to the
consideration of things which he could understand. Almost at his feet was
Maka, lying on his face, his arms and head over the edge of what might be
a bank or a bottomless precipice, and yelling piteously. Making a step
toward him, the captain saw that he had hold of another man, several feet
below him, and that he could not pull him up.

"Hold on tight, Maka," he cried, and then, taking hold of the African's
shoulders, he gave one mighty heave, lifted both men, and set them on
their feet beside him.

Ralph would have willingly sacrificed the rest of his school-days to be
able to perform such a feat as that. But the Africans were small, and the
captain was wildly excited.

Well might he be excited. He was wet! The strange man whom he had pulled
up had stumbled against him, and he was dripping with water. Ralph was by
the captain, tightly gripping his arm, and, without speaking, they both
stood gazing before them and around them.

At their feet, stretching away in one direction, farther than they could
see, and what at first sight they had taken to be air, was a body of
water--a lake! Above them were rocks, and, as far as they could see to
the right, the water seemed to be overhung by a cavernous roof. But in
front of them, on the other side of the lake, which here did not seem to
be more than a hundred feet wide, there was a great upright opening in