re a natural wonder presented itself. From a hole about
fifteen feet above them issued a cascade, which poured in a foaming fall
over a ledge of rock, ran for a distance of about eight yards over the
floor of the cavern, then plunged into a deep hole and disappeared.

"I wonder where it comes out--if it ever comes out at all?" said
Dorothy, shuddering as she watched the black water whirl into the dark
abyss.

"Lower down the mountain, probably, but I shouldn't care to try the
experiment of jumping in to find out," said Eric. "It's a weird place,
but it's worth seeing. I'm glad we came. I believe it's finer than
Lingham. And we've done it on our own, too, without any bothersome
guide."

"We've got to go back yet," said Gabrielle. "Hadn't we better make a
start? It must be getting late."

"Exactly twenty minutes to four," said Percy, consulting his watch.

"Then we must go at once. Remember, we have a long walk before us."

Quite loath to leave the marvels of the subterranean chamber, they tore
themselves away, each first breaking off a small stalactite as a
souvenir.

"I shall treasure my limestone 'icicle'," said Dorothy. "I shall score
if I take it to the geology class at school."

"I've got an extra one to give to the College museum," said Gabrielle.
"I hope they won't break in my pocket. I've wrapped them carefully in my
handkerchief."

Arrived at the chute, Percy climbed up first, with one end of the rope
in his hand, then, stationing himself firmly at the top, announced his
readiness to haul up the others. Gabrielle started next, crawling on
hands and knees, and helping herself as best she could by the
projections of rock at the side. It was much more difficult to ascend
than to descend, for the surface was so smooth and slippery, it was
impossible to get any grip. Almost her whole weight depended upon the
rope; she was a heavy girl, and the strain was great. Percy at the top
heaved with all his strength.

"Oh dear, it's dreadful!" cried Gabrielle. "It's cutting my waist in
two. Wait a moment, Percy; don't tug so hard. I want to catch this
ledge."

"Let go of the rock, and I'll give one good pull," commanded Percy. "If
you'll trust yourself absolutely to me, I'll have you up in a jiffy."

Gabrielle loosened her hold, and for one moment threw herself entirely
upon the rope. Perhaps it was not strong enough for the purpose, or
possibly it had been frayed in the descent by contact with a sharp rock;
th