g was reached, not a geyser like those on the
shelf across the long valley, but a little gurgling fount of the most
beautifully pure water, but so heated that it was impossible to thrust a
hand therein.

"Are we going much higher, Mr Mark?" said Billy Widgeon at last.
"Feels to me as if we should go through before we knowed where we was."

"Going to the top, I suppose," said Mark, smiling at the man's face,
though he could not help feeling some slight trepidation as strange
volcanic suggestions of what was beneath them in the mountain kept
manifesting themselves at every step.

"Oh, all right!" said Billy in a tone of resignation; "but I do purtest,
if I am to die, agin being biled."

The climb up the mountain side was continued for some time, fresh
wonders being disclosed at every step. The jungle grew less thick, with
the result that flowers were more plentiful, and if not more abundant
the birds and gloriously-painted insects were easier to see. Hot
springs were plentiful, and formed basins surrounded by the deposit from
the water, a petrifaction of the most delicate tints, while the water
was of the most exquisite blue.

A little higher, and in a narrow ravine among the rocks a perfect chasm,
into which they descended till the sides almost shut out the light of
day, so closely did they approach above their heads, Mark, who was in
advance, made a find of a deposit of a delicate greenish yellow.

"Why, here's sulphur!" he exclaimed, picking up a beautifully
crystallised lump, while the rock above was incrusted with angular
pieces of extreme beauty.

"Yes, sulphur," said the captain; "and I don't think we'll go any
farther here. It may be risky."

"I'll just see how soon this cleft ends," said the major, approaching
what seemed to be the termination of the gorge--quite a jagged rift, cut
or split in the side of the mountain.

The major went on cautiously, for, as he proceeded, it grew darker, the
rift rapidly becoming a cavern.

"It runs right into the mountain!" he cried, and his voice echoed
strangely. "Here, Mark, my lad, if you want to see some specimens of
sulphur, there are some worth picking here."

There was something so weirdly attractive in the cavern that Mark
followed, and in setting his feet down cautiously on the rocky floor his
eyes soon became accustomed to the gloom, and he found that the rock
joined about a dozen feet above their head, and was glittering as if
composed of pale golden