Note 11 — CHAP. II.

Earthquakes are frequent in the West Indies, and perhaps proceed from a weaker operation of the same cause that originally produced the islands themselves, which seem all to have been raised from the sea by subterraneous fire. There are evident vestiges of volcanoes in them all, except Barbadoes; but there are other unequivocal marks of this island having been raised from the bottom of the sea; for it is entirely formed of coral, and other sub-marine productions, of which the strata are broken, and the parts set at angles to each other, as might be expected from such a cause. There is, perhaps, at all times in the caverns of the earth, elastic vapour struggling to vent itself, and when near the surface, it may sometimes overcome the incumbent masses of matter, and produce certain convulsions of nature. In the account of the hurricane which I wrote to Dr. Hunter, I gave reasons for believing, from the testimony of the inhabitants, that hurricanes are attended with earthquakes; and if a conjecture might be advanced concerning the cause of this, it might be said, that as the atmosphere is lighter at that time, by several inches of the barometer, the elastic vapour, confined by the weight of the incumbent earth and atmosphere, being less compressed, may exert some sensible effects, producing a sort of explosion.