But an
island like this would be nothing to it without the coral insects
stopped it. Some volcanoes rise in these seas and never get much above
the surface--the waves wash them away as fast as they form. You see
they are only made up of loose cinders and ashes which fall over outside
as they are thrown up. Others are more solid if liquid lava boils over
the edge of the crater and runs down. This gradually hardens into
massive rock, and resists the beating of the sea till the coral insects
have done their work, building up to the surface of the sea, and then
going on at the sides."

"I suppose you are right," said Jack with a yawn, "but the sooner we get
away from this ugly place the better."

"Think so? Well, wait and see it by daylight first. Look!"

He pointed to where, nearly a mile above them, a bright golden spot had
appeared.

"Why, the volcano's burning," cried Jack excitedly. "Look! It's
red-hot, and gradually increasing. There's going to be an eruption.
How grand! But shall we be safe here?"

"Quite," said the mate, smiling, and he stood watching his companion's
face, and its changes in the glowing light of the magnificent spectacle,
as the golden red-hot aspect of the mountain top rapidly increased,
displaying every seam, ravine, and buttress, that seemed to be of
burning metal, fiery spot after fiery spot, that the minute before was
of a deep violet black. And this went on, with the fire appearing to
sink gradually down till the whole of the mountain top was one grand
blaze of glory, which went on apparently sinking behind a belt of
clouds, till from being of dark and gloomy grey they began to glow and
become of a wonderful translucency.

"Oh!" panted the lad, "I never saw anything so grand as that. Look how
the awful fire is reflected in the sky all round there."

"Yes, it's brightening it well up," said the mate, smiling; and then the
boy looked in his face, and the truth came to him like a flash from the
great orb to enlighten his understanding.

"Why, you're laughing at me," he cried. "How stupid! I thought the
mountain was burning. You should have told me. How was I to--Yes, I
ought to have known that mountain tops first caught the light. Oh, I
wish I were not so ignorant."

"You are not the first who has been deceived," said the mate quietly.
"Well, the mountain does not look so gloomy now, does it?"

"Glorious! Up there it is grand. I wish we were on the top."

"All in