death.

"Three hundred feet and we shall be there," came the encouraging voice
of the guide. "Half an hour more."

"I could make it half a minute if I wanted to," said Stacy. "But I
don't want to. I feel it my duty to stay and look after my friends."

"Yes, your friends need you," answered Ned sarcastically. "If they
hadn't I never should have pulled you out of the hole in the crater."

"I was just wondering how Chunky could resist the temptation of
falling in here. He'll never have a better opportunity for making a
clean job of said Walter.

"He has explained why," replied Tad. "We need him. Of course we do.
We need him every hour-----"

"And a half," added Ned.

The roar of the river became louder as they descended. Now they were
obliged to raise their voices to make themselves heard. The Professor
was toiling and sweating, but making no complaint of the hardships.
He was plucky, as game as any of those hardy boys for whom he was the
companion, and they knew it.

"Hold on here!" cried Stacy, halting.

All turned to see what was wrong.