The wonders of the world

by John Loraine Abbott

Crushed horrible, and pile on pile o’erturned,

Fall total.”—Mallet.

“The globe around earth’s hollow surface shakes,

And is the ceiling of her sleeping sons.

O’er devastation we blind revels keep;

Whose buried towns support the dancer’s heel.”—Young.

That fires, to a very great extent, and produced by various causes, exist at different depths beneath the surface of the earth, must be entirely evident to those who have perused the accounts of volcanoes in our previous pages; and recent experiments have shown, that where the substances in which such fires occur, lie at a considerable depth, and are surmounted by a very deep and heavy superincumbent pressure, more especially when they contain large portions of elastic gases, the effect of such fires will be much greater, and more diversified, than where these circumstances are absent.

Among the most powerful and extraordinary of these effects earthquakes are to be reckoned. They are unquestionably the most dreadful of the phenomena of nature, and are not confined to those countries which, from the influence of climate, their vicinity to volcanic mountains, or any other similar cause, have been considered as more particularly subject to them, their effects having oft been felt in North America, although not in so extensive and calamitous a degree. Their shocks and the eruptions of volcanoes, have been considered as modifications of the effects of one common cause; and where the agitation produced by an earthquake extends further than there is reason to suspect a subterraneous commotion, it is probably propagated through the earth nearly in the same way that a noise is conveyed through the air. The different hypotheses which have been imagined on this subject may be reduced to the following. Some naturalists have ascribed earthquakes to water, others to fire, and others, again, to air; each of these powerful agents being supposed to operate in the bowels of the earth, which they assert to abound everywhere with huge subterraneous caverns, veins and canals, some filled with water, others with gaseous exhalations, and others replete with various substances, such as niter, sulphur, bitumen and vitriol. Each of these opinions has its advocates, who have written copiously on the subject.

In a paper published in the “Philosophical Transactions,” Dr. Lister ascribes earthquakes, as well as thunder and lightning, to the inflammable breath of the pyrites, a substantial sulphur, capable of spontaneous combustion; in a word, as Pliny had observed before him, he supposes an earthquake to be nothing more than subterraneous thunder. Dr. Woodward thinks, that the subterraneous fire which continually raises the water from the abyss, or great reservoir, in the center of the earth, for the supply of dew, rain, springs and rivers, being diverted from its ordinary course by some accidental obstruction in the pores through which it is used to ascend to the surface, becomes, by such means, preternaturally assembled in a greater quantity than usual, in one place, and thus causes a rarefaction and intumescence of the water of the abyss, throwing it into greater commotions, and at the same time making the like effort on the earth, which, being expanded on the surface of the abyss, occasions an earthquake. Mr. Mitchell supposes these phenomena to be occasioned by subterraneous fires, which, if a large quantity of water be let loose on them suddenly, may produce a vapor, the quantity and elastic force of which may fully suffice for the purpose. Again, M. Amontus, a member of the French Academy of Sciences, endeavors to prove, that, on the principle of experiments made on the weight and elasticity of the air, a moderate degree of heat may bring that element into a state capable of causing earthquakes.

Modern electrical discoveries have thrown much light on this subject. Dr. Stukely strenuously denies that earthquakes are to be ascribed to subterraneous winds, fires or vapors, and thinks that there is not any evidence of the cavernous structure of the earth, which such a hypothesis requires. Subterraneous vapors he thinks, are altogether inadequate to the effects produced by earthquakes, more particularly in cases where the shock is of considerable extent: for a subterraneous power, capable of moving a surface of earth only thirty miles in diameter, must be lodged at least fifteen or twenty miles below the surface, and move an inverted cone of solid earth, whose basis is thirty miles in diameter, and its axis fifteen or twenty miles, which he thinks absolutely impossible. How much more inconceivable is it, then, that any such power could have produced the earthquake of 1755, which was felt in various parts of Europe and Africa, and in the Atlantic ocean; or that which in Asia Minor, in the seventeenth year of the Christian era, destroyed thirteen great cities in one night, and shook a mass of earth three hundred miles in diameter. To effect this, the moving power, supposing it to have been internal fire or vapor, must have been lodged two hundred miles beneath the surface of the earth! Besides, in earthquakes, the effect is instantaneous; whereas the operation of elastic vapor, and its discharge, must be gradual, and require a long space of time; and if these be owing to explosions, they must alter the surface of the country where they happen, destroy the fountains and springs, and change the course of its rivers, results which are contradicted by history and observation.