in England, some from the West-Indies (in both which countries earthquakes are more frequent than with us) did seem to apprehend our first earthquake, from the apparent temper of the weather; and observations of this kind are as old as Aristotle. It is observed in Jamaica when the air is extraordinary calm, an earthquake is always apprehended.
We had lately read at the Royal Society, a very curious discourse, from Mr. Franklin of Philadelphia, concerning thundergusts, lightning, the northern lights, and like meteors. All which he rightly solves from the doctrine of electricity. For, if a cloud raised from the sea, which is a non-electric, happens to touch a cloud raised from exhalations of the land, when electrified, it must immediately cause thunder and lightning. The electrical fire flowing from the touch of perhaps a thousand miles compass of clouds, makes that appearance which we call lightning. The snap which we hear in our electrical experiments, when re-echoed from cloud to cloud, the extent of the firmament, makes that affrightning sound of thunder.
From the same principle I infer, that, if a non-electric cloud discharges its contents upon any part of the earth, when in a high electrified state, an earthquake must necessarily ensue. The snap made upon the contact of many miles compass of solid earth, is that