I have only one circumstance to add, which may seem not inconsiderable; probably perceived by many, tho' not taken notice of. For a whole week before the first earthquake, the partition wainscot of my house (between the forward and backward rooms) made an odd kind of tremulous, crackling noise continually, as if the wainscot would split; or as if some damage was apprehended to the house. This was observ'd by the family, with a good deal of concern. That in the chamber crackled more than that below. We never perceiv'd it before, nor since; and apparently, it shows the vibratory state of the surface of the earth, at that time.
But whether our conjectures upon this important subject be well founded or no, it certainly becomes a christian philosopher, whilst he is investigating material causes, to look up, and regard the moral use of them. For in reality, every thing, the whole world, was ultimately for that purpose made. When we see such a kind of spirituality impress'd on mere matter, as this amazing property of electricity, it should kindle in us a high ambition of asserting, and exerting the infinitely superior value, and powers, and excellency of the spiritual part of us, destin'd to an immortal duration. And of all the great and public calamities, which affect us mortals, earthquakes claim the first title to the name of warnings and judgments. None so proper to threaten, or to execute vengeance upon a guilty people. Nor has any other, those annexed terrors, so much of the unusual, the unavoidable, the sudden and the horrible apprehension of being crush'd to death, or buried alive. And when in our own sight, these rare and extraordinary phænomena appear, it cannot but be a lesson to us, to do our duty toward that great Being, who, by a drop of water, can produce effects so prodigious.
That earthquakes proclaim themselves to mankind in this light, is further deducible from this observation, the ninth in our recapitulation of circumstances; that they are peculiarly directed to great cities, and maritime towns, those nurseries of wealth, luxury, and of all the evils naturally flowing therefrom. It would be childish to rehearse from old history, or modern, a proof of it. We have no other notices of them. Look upon these two shocks we have here felt. We own that Hampsted-heath, and Finchley-forest, and Kennington-common were affected with it; yet it is notorious, that London was the center, the place to which the finger of God was pointed.
And this leads us in the third place, to consider the moral use and purpose of these magnalia naturæ, and prodigies of the agency of material causes. For nothing sure, but an electrical shock, and that from a divine hand, could have been so well adjusted, as twice, nay four times, so sensibly to shake every house in London, and not throw one down. This duty we will endeavour to execute, from the words of that great man, king David.
[PSALM xviii. 7.]
Then the earth shook, and trembled; the foundations also of the hills moved, and were shaken; because he was wroth.
This Psalm is a triumphal song, which David deliver'd publickly before God, in thankful remembrance of the great mercies he had receiv'd; being firmly established on his throne: and all his enemies, foreign or domestick, subdued.