to be huge,
rounded lumps placed here and there upon heaps of broken stones or
blocks which had fallen from the roof some ten or a dozen feet overhead,
while at one end the top of the cave sloped down to join the rising
floor.

"This seems to be the bottom of the cave," said Captain Roby. "Now,
sharp, my lads. Keep that way out safe."

"Which?" said Dickenson. "Here's another hole in the floor. Lantern
here. Yes, there's another private staircase with a flight of steps
ready. This ought to be the well. Yes; come and listen. You can hear
water rushing."

Sure enough, as they bent over the gloomy, mysterious-looking hole, up
which a cool, moist breath of air arose, they could hear the gurgling
rush of hurrying water, while the light held down showed the rugged bark
of another tree ready for descent.

"Will you go down, Lennox?" said the captain.

"Oh yes, I'll go down," was the reply.

"Well, undress," said Dickenson banteringly. "It means a swim. Don't
spoil your neat uniform."

"Will you go?" asked Lennox sharply.

"Oh yes, I'll go," said Dickenson.

"Thank you," replied Lennox through his set teeth.--"Here, sergeant,
give me the lantern."

Catching it from the man, he planted his foot upon the first branch
stump a foot below the edge of the yawning hole; but the moment he
touched it a violent jerk was given to the tree-trunk, just as if it had
been seized by some one below and wrenched round.

Lennox's position was so insecure, with one hand holding the lantern,
that he was thrown off his balance, and he would have fallen headlong
down but for the snatch he made at the sergeant, who also caught at him,
slipped, and the two were nearly precipitated down the horrible place at
the bottom of which the water was rushing with a hollow, echoing,
whispering sound.

The tree saved them, the sergeant getting a firm hold; but between them
the light of the lantern was shut off, hidden between the two men for
the moment, and an attempt was made by Dickenson to reach and drag it
up.

"I've got it," he cried. "Let it come. No, I haven't; mind."

For it had slipped through his fingers, and it went clattering down the
rough, well-like place, striking against one of the projecting stumps of
the tree-trunk, which turned it right over and threw it with an echoing
crash against the wall, lit it up for a moment, and then the flame
within was extinguished.

"Yah!" roared Captain Roby as the place was plunged