Etidorhpa; or, The End of Earth. / The Strange History of a Mysterious Being and the Account of a Remarkable Journey

by John Uri Lloyd

"See," he observed, and dipping his finger into the water he held it before him with a drop of water attached thereto (Figure 27), the globule being of considerable size, and lengthened as though it consisted of some glutinous liquid.

"How can a thin stratum of water give rise to a volcanic eruption?" I next queried. "There seems to be no melted rock, no evidence of intense heat, either beneath or about us."

"I informed you some time ago that I would partially explain these facts. Know then, that the theories of man concerning volcanic eruptions, in connection with a molten interior of the earth, are such as are evolved in ignorance of even the sub-surface of the globe. The earth's interior is to mankind a sealed chamber, and the wise men who elucidate the curious theories concerning natural phenomena occurring therein are forced to draw entirely upon their imagination. Few persons realize the paucity of data at the command of workers in science. Theories concerning the earth are formulated from so little real knowledge of that body, that our science may be said to be all theory, with scarcely a trace of actual evidence to support it. If a globe ten inches in diameter be covered with a sheet of paper, such as I hold in my hand, the thickness of that sheet will be greater in proportion to that of such a globe than the depth men have explored within the earth is compared with the thickness of the crust of the earth. The outer surface of a pencil line represents the surface of the earth; the inner surface of the line represents the depth of man's explorations; the highest mountain would be represented by a comma resting on the line. The geologist studies the substances that are thrust from the crater of an active volcano, and from this makes conjectures regarding the strata beneath, and the force that casts the excretions out. The results must with men, therefore, furnish evidence from which to explain the cause. It is as though an anatomist would form his idea of the anatomy of the liver by the secretion thrown out of that organ, or of the lung texture by the breath and sputum. In fact, volcanoes are of several descriptions, and usually are extremely superficial. This lake, the surface of which is but one hundred and fifty miles underground, is the mother of an exceptionally deep one. When the water pours over this ledge it strikes an element below us, the metallic base of salt, which lies in great masses in some portions of the earth's crust.[9] Then an immediate chemical reaction ensues, the water is dissociated, intense heat results, part of the water combines with the metal, part is vaporized as steam, while part escapes as an inflammable gas. The sudden liberation of these gases causes an irregular pressure of vapor on the surface of the lake, the result being a throbbing and rebounding of the attenuated atmosphere above, which, in gigantic waves, like swelling tides, dashes great volumes of water over the ledge beside us, and into the depth below. This water in turn reacts on fresh portions of the metallic base, and the reflex action increases the vapor discharges, and as a consequence the chamber we are in becomes a gasholder, containing vapors of unequal gas pressures, and the resultant agitation of the lake from the turmoil continues, and the pulsations are repeated until the surface of the lake is lowered to such a degree as at last to prevent the water from overflowing the barrier. Finally the lake quiets itself, the gases slowly disappear by earth absorption, and by escape from the volcanic exit, and for an unrecorded period of time thereafter the surface of the lake continues to rise slowly as it is doing now."

[9] This view is supported in theory by a note I believe to have somewhere seen recorded. Elsewhere other bases are mentioned also.—J. U. L.

"But what has this phenomenon to do with the volcano?"

"It produces the eruption; the water that rushes down into the chasm, partly as steam, partly as gas, is forced onward and upward through a crevice that leads to the old crater of the presumed extinct but periodically active Mount Epomeo. These gases are intensely heated, and they move with fearful velocity. They tear off great masses of stone, which the resultant energy disturbances, pressure, gas, and friction, redden with heat. The mixture of gases from the decomposed water is in large amount, is burning and exploding, and in this fiery furnace amid such convulsions as have been described, the adjacent earth substance is fused, and even clay is melted, and carried on with the fiery blast. Finally the current reaches the earth's surface through the funnel passage, the apex of which is a volcano—the blast described a volcanic eruption."

"One thing is still obscure in my mind," I said. "You assert that the reaction which follows the contact of the flowing water and metallic bases in the crevice below us liberates the explosive gases, and also volumes of vapor of water. These gases rush, you say, and produce a volcanic eruption in a distant part of the crust of the earth. I can not understand why they do not rush backward as well, and produce another eruption in Kentucky. Surely the pressure of a gas in confinement is the same in all directions, is it not?"

"Yes," he replied, "but the conditions in the different directions are dissimilar. In the direction of the Kentucky cavern, the passage is tortuous, and often contracts to a narrow crevice. In one place near the cavern's mouth, as you will remember, we had to dive beneath the surface of a stream of water. That stratum of water as effectually closed the exit from the earth as the stopper prevents water escaping from a bottle. Between the point we now occupy and that water stopper, rest thousands of miles of quiescent air. The inertia of a thousand miles of air is great beyond your comprehension. To move that column of air by pushing against this end of it, and thus shoving it instantly out of the other end, would require greater force than would burst the one hundred and fifty miles of inelastic stone above us. Then, the friction of the sides is another thing that prevents its accomplishment. While a gradually applied pressure would in time overcome both the inertia of the air and the friction of the stone passages, it would take a supply of energy greater than you can imagine to start into motion the elastic mass that stands as solid and immovable as a sentinel of adamant, between the cavern you entered, and the spot we now occupy. Time and energy combined would be able to accomplish the result, but not under present conditions.

"In the other direction a broad open channel reaches directly to and connects with the volcanic shaft. Through this channel the air is in motion, moving towards the extinct crater, being supplied from another surface orifice. The gases liberated in the manner I have described, naturally follow the line of least resistance. They turn at once away from the inert mass of air that rests behind us, and move with increasing velocity towards the volcanic exit. Before the pressure that might be exerted towards the Kentucky cavern would have more than compressed the intervening column of air enough to raise the water of a well from its usual level to the surface of the earth, the velocity in the other direction would have augmented prodigiously, and with its increased rapidity a suction would follow more than sufficient to consume the increasingly abundant gases from behind."