Even in vulcano's, it is the opinion of the learned Italian philosopher Borelli, and of other great naturalists, that they are kindled first from the surface, where there is a possibility of ventilation from the air. They imagine, it begins at the top of the mountains; not by any fancied fermentation of the pyrites and sulphureous vapours arising from subterraneous caverns, in the lower parts of mountains.
There is another consideration, which utterly overthrows these suppositions, of earthquakes being caused by anything under-ground; and that is a due consideration of springs, and fountains perpetually flowing; and that from the creation of the world to this day. If we would form any tolerable idea of their nature, we must needs conceive, that God Almighty has laid their pipes, and canals in the earth, from a great depth, even to the surface; like as he has planted the veins, arteries, and glands in an animal body. And likewise that they are more and more ramify'd, as they nearer approach the outward shell of the earth; just so our veins, and arteries, as they come nearer the skin.
The workmen in coal-mines, and those of metals, minerals, and stone-quarries, never fail to meet with springs, and currents of water, every where. Often they ruin, and divert springs another way, only by digging into the earth for foxes, and the like. Whenever they dig for wells, in any kind of earth, they commonly find springs. The colliers, and workers of mines, are oblig'd to drain the waters off with very great expence.
These are circumstances not favorable to subterraneous fires being in the earth in abundance; much less to their being the cause of earthquakes. And further, we cannot possibly think of earthquakes doing their work that way, without absolutely ruining the whole system of springs, and fountains, throughout the whole country, where they pass. But all this is quite contrary to fact; even where an earthquake has been repeatedly. For an instance from home.
On Wednesday, April 6, 1580, about six in the evening, just such another earthquake was felt in London and around it, as these two we have seen. Another exactly similar 1692. In all these four, no houses thrown down, no springs disturb'd thereby, no sensible eruptions nor smells.
These considerations I apply only to this little inconsiderable space, of a circle 30 miles diameter; as with us. But what is that to the earthquakes we read of in history? In the year of our Lord 17, no less than thirteen great and noble cities in Asia minor, were destroyed in one night. Tacitus, Pliny, and many other authors mention it. The fact is so notorious, that some persons here present, have seen a vast block of white marble now standing near Naples; being the pedestal of a coloss statue of Tiberius the emperor; having carv'd on it the genius's, or pictures of all those cities, with their names. The accurate Bulifon and others have wrote treatises upon it. These cities were rebuilt by that emperor. But without going so far, we may see another evidence of it, a coin of that emperor struck upon the occasion, with this inscription,
CIVITATIBUS ASIAE RESTITUTIS.
I have one of them, in large brass, which was found at Colchester.
The compass of this earthquake may be reckon'd to take up 300 miles diameter, as a circle. Now, we cannot conceive, how any subterraneous vapour can produce such an effect, as instantaneously to demolish all these cities; and that such an accident should never happen after. That the whole country of Asia minor should not at the same time be destroy'd, its mountains be renversed, its fountains, springs, and rivers broken up and ruin'd for ever. Instead whereof we find nothing suffered, but those cities; no kind of alteration in the surface of the country; it remains the same as it were in the beginning of time. In 1586 an earthquake in Peru, that extended 900 miles.
From these considerations, I cannot persuade myself, to enter into the opinion of vapours, and eruptions being the cause sought for; and, after we have treated the argument in a superficial view, we must go a little deeper.