Earthquakes explained and practically improved occasioned

2. Before an Earthquake there is something discerned, as an ascending Fume, resembling a long Line, which Fume is the thinner Exhalation, which begins to get forth: but the rest of the Exhalations, by reason of their greater density and straightness of the Passages, are restrained within the bowels of the Earth, from whence an Earthquake doth arise.

3. He saith in his time there were some Earthquakes in Pontus, before ⟨p. 56⟩which the Earth did swell, and at last did burst, or was broke asunder; which was a certain sign of Exhalations shut up and seeking their way out.

Derodon judgeth it more probable that Earthquakes do arise from a sudden inflammation of sulphureous [Brimstone-like] and bituminous [something like Pitch, or fat Slime] Vapours which are kindled in the Caverns and hollow Places under ground, not much distant from the Surface of the Earth, which according as the Caverns are, and as the matter of the Flame is more or less, do variously operate; for the most part they effect nothing, if the Earth be more loose, and hath breathing holes a• which they may get out: sometimes they move it more gently, and make it tremble, if the bulk above it be greater, that this subterraneous Flame can assay, attempt and do no more against it sometimes they shake and overturn, by reason of their greatness, and resistance of the parts of the Earth.