Peripateticall institutions. In the way of that eminent person and excellent philosopher Sr. Kenelm Digby. The theoricall part. Also a theologicall appendix of the beginning of the world. / By Thomas White Gent.

LESSON XI.

Of Earth-quakes and their Effects.

1. BUt, because we have said, there are Caves under ground; and both our experience of Pits sunk, and many extraordinary effects demon∣strate Fire & water, there, too: there must necessarily be notable effects of the va∣pours extracted out of the bowells of the Earth.

2. If, therefore, out of some subterrane∣ous humidbody, vapours chance to be rais'd, by a subterraneous fire, too; and they prove too bigg for their place: 'tis manifest that, alwaies increasing and be∣coming condens'd, by the continuall ac∣cesse of new vapours, they'l seek themselves a way out, according to the force they have, where ther's the easiest passage. If that chance to lead into any vast under∣ground Cave, the Earth will quake with a great impetus and groan; but nothing will appear above ground.

3. But, if the easiest issue be towards the superficies of the Earth, the vapour will burst out through it: and, if it be noxious to Beasts or Birds, 'twill bring

either Death or a Disease along with it; making with the eruption either a gaping Hollow or a Mountain, according as the Earth either sinks or is sustain'd and, as it were, vaulted. Sometimes 'twill bury and swallow up Cities; sometimes transport vast pieces of Earth; and produce other effects, whereof we find expresse memori∣alls in History.

4. The Prognosticks of an Earth-quake, they say, are an infection of the Fountains with a sulphurious savour; an unusuall calmnesse of the Air and Birds; a swelling of the Sea without any apparent cause; blackish streaks under the Sun of an unu∣suall length: all (if they are truly Progno∣sticks, and not onely Accidents, which, sometimes and not for the most part, hap∣pen) are the effects of a spirituous Va∣pour bursting out from the bowells of the Earth.

5. They are said to happen chiefly in the Spring and Autumn, therefore, (if the opinion be true) because the Superficies of the Earth, being warm, becomes slacker with the rain: But, I should rather believe it a chance that many should be recorded in Histories about these seasons; for, both Winter and Summer have felt their Earth∣quakes,

and in the Torrid Zone, where they are most frequent, the differences of Spring and Autumn from the other sea∣sons are very inconsiderable.

6. The Sea-shores are most subject to these motions; because the subterranious flames and fumes receive no little nourish∣ment from the Sea; and the moisture which soaks into the Earth, renders it very fit for breeding vapours.