“Do not you feel a certain vibration of the soil?” asked Cyrus Harding.
“Yes,” replied Gideon Spilett, “but there is a great difference between that and an earthquake.”
“I do not affirm that we are menaced with an earthquake,” answered Cyrus Harding, “may God preserve us from that! No; these vibrations are due to the effervescence of the central fire. The crust of the earth is simply the shell 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 vapors. 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 machine-guns.
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 vapors 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?’