As Mark gazed down into the depths, which seemed fathomless, and which
were as black as night, he saw his friend clinging to a rocky
projection on the side of the extinct volcano. Jack had managed to
grasp a part of the rough surface as he slid down it after his reckless
jump. He looked up and saw Mark.

"Oh, Mark, can't you save me?" he gasped. "Call Professor Henderson!"

"I'll get you up, don't worry!" called Mark, as confidently as he
could. "Hold tight, Jack. What has become of your life-torch?"

"I have it here by me. I didn't drop it, and it's on a piece of the
rock near my head. Otherwise I couldn't breathe. Oh, this place is
fearfully deep. I guess it hasn't any bottom."

"Now, keep still, and don't think about that. Save your strength, hold
fast, and I'll get you up."

But, having said that much, Mark was not so sure how next to proceed.
It was going to be no easy task to haul up Jack, and that without ropes
or other apparatus. Another matter that added to the danger was the
necessity of keeping the life-torch close to one's face in order to
prevent death by the poisonous gases.

Mark's first impulse was to hasten back and call the two professors,
but he looked over the desolate landscape, and could not see them, and
he feared that if he went away Jack might slip and fall into the
unknown depths of the crater.