a
serpent on one side and savages on the other, was not more alarmed.

"Keep still," whispered the major; "we must hear them directly. What's
that?"

"The dog," said Mark in the same low tone, for Bruff had softly crept to
their side, looked up in their faces, and lain down.

"Why, hallo!" exclaimed the major, "this isn't natural."

"What?"

"This dog. There can't be any savages on the way; and, what is more,
you can't have shot a serpent, or Bruff here would have been excited and
routed him out. Did you see the serpent?"

"No, sir; I didn't see it exactly, but you heard it hiss."

"But, hang it all, Mark! You didn't shoot at a hiss, did you?"

"Well, no, sir. I was horribly startled, and shot down at the soft
thing upon which I jumped."

"But if you are entrusted with a gun," said the major angrily, "you
mustn't take fright and shoot at what you hear and feel, my lad."

"Did you see the savages, sir?" said Mark in self-defence.

"Well, no, but I saw the smoke of their fire; and here, Bruff, fetch him
out, boy," he continued, breaking off his speech, and with cocked gun he
parted the twigs and fronds cautiously as he stepped down into the
hollow from which Mark had fled.

Hiss! hiss! hiss! came sharply from where the major stepped, and he in
turn bounded back to Mark's side, falling over the dog, and having some
difficulty in recovering himself.

"That's good! I like that," he cried, as, instead of helping him, Mark
covered his escape by taking a step forward, and bringing his gun to
bear on the spot whence the sounds came.

"Did--did you see it?" said Mark huskily.

"See it! No, my lad. Only that! Look!"

He pointed as he rose to a filmy vapour floating away and dissolving in
the sunshine. "You did not see that before because you fired. Don't
you see? It's steam."

"Steam!" said Mark.

"Yes. Look here. Give me your hand. I don't want to go through."

He caught Mark's hand and stepped cautiously down, keeping one foot on
sure ground, as with the other he pressed and stamped upon a spot that
was quite elastic. At every stamp there was a hiss--a sharp, angry hiss
and a puff of vapour rose from among the leaves.

"There's your serpent," he said, laughing. "No wonder you did not hit
it."

"Then that must be steam we saw over yonder, and not savages' fires."

"Right, my lad. A false alarm. We're in a volcanic land, and if we
search about I daresay we shall find hot springs somew