, black, rounded cone, like
the cupola of an immense blast furnace. This cone was about fifty feet
high, and there was an opening at the top eight or ten feet in diameter,
which glowed with a furious heat, and emitted quietly, but continually,
a red-hot breath of sulphurous vapor.

After remaining thus quiet for a few moments, suddenly it would give a
gasp, and immediately afterwards there would burst forth a thundering
explosion, which seemed to come up from a great depth below, and threw
into the air a shower of stones and scraps of molten lava, which, after
ascending to a great height, came down again, and fell, with a dripping
sound, upon and around the cone. Similar explosions occurred at
intervals of a few minutes, all the time that the party remained.

Rosie was at first very much afraid of these explosions, and she wished
to go back. Mr. George himself was also afraid at first to stand very
near the edge of the crater; but it was not on account of the
explosions, but for fear that the cliff might cave in. Indeed, the
cliffs all around were cracked off, and in some places leaning over,
apparently ready to fall; and even at the spot where the spectators
stood looking into the crater, there was a fissure running along
parallel to the cliff, some feet behind them. At first Mr. George was
afraid to step over this crack.

"How do they know," said he to himself, "but that the whole mass will
fall and carry them all down into the gulf below?"

He found, however, after waiting a little while, that it did not fall,
and there were besides other masses a little farther along, as seen in
the engraving, which had become separated entirely from the cliff behind
them, leaving a chasm open two or three feet wide; and yet they did not
fall. So Mr. George gradually acquired more confidence, and at length
went cautiously forward, and looked over the brink.

Rosie, however, hung back. She was alarmed to see Rollo and Josie go so
near.

"Come back, Josie," said she; "come back. You _must not_ go so near."

So Mr. George called the boys back, and they obeyed.

The walls of this crater were on every side almost perpendicular. As the
central part had gradually sunk, the sides had caved off and fallen in,
and then afterwards the lava that had been thrown up had spread over the
floor, and covered it with a bed of a half-fluid looking substance,
that was as black as pitch, and which, though it was really now pretty
hard, looked as