ell of a boiler, and you know that such a shell, under the
pressure of steam, vibrates like a sonorous plate. It is this effect
which is being produced at this moment."

"What magnificent flames!" exclaimed Herbert.

At this instant a kind of bouquet of flames shot forth from the crater,
the brilliancy of which was visible even through the vapours. Thousands
of luminous sheets and barbed tongues of fire were cast in various
directions. Some, extending beyond the dome of smoke, dissipated it,
leaving behind an incandescent powder. This was accompanied by
successive explosions, resembling the discharge of a battery of
mitrailleuses.

Cyrus Harding, the reporter, and Herbert, after spending an hour on the
plateau of Prospect Heights, again descended to the beach, and returned
to Granite House. The engineer was thoughtful and preoccupied, so much
so, indeed, that Gideon Spilett inquired if he apprehended any immediate
danger, of which the eruption might directly or indirectly be the cause.

"Yes, and no," answered Cyrus Harding.

"Nevertheless," continued the reporter, "would not the greatest
misfortune which could happen to us be an earthquake which would
overturn the island? Now, I do not suppose that this is to be feared,
since the vapours and lava have found a free outlet."

"True," replied Cyrus Harding, "and I do not fear an earthquake in the
sense in which the term is commonly applied to convulsions of the soil
provoked by the expansion of subterranean gases. But other causes may
produce great disasters."

"How so, my dear Cyrus?"

"I am not certain. I must consider. I must visit the mountain. In a
few days I shall learn more on this point."

Gideon Spilett said no more, and soon, in spite of the explosions of the
volcano, whose intensity increased, and which were repeated by the
echoes of the island, the inhabitants of Granite House were sleeping
soundly.

Three days passed by--the 4th, 5th, and 6th of January. The
construction of the vessel was diligently continued, and without
offering further explanations the engineer pushed forward the work with
all his energy. Mount Franklin was now hooded by a sombre cloud of
sinister aspect, and, amid the flames, vomited forth incandescent rocks,
some of which fell back into the crater itself. This caused Pencroft,
who would only look at the matter in the light of a joke, to exclaim--

"Ah! the giant is playing at cup and ball; he is a conjuror."