THE EARTH. 91 



CHAPTER X. 



OF EARTHQUAKES. 



HAVING given the theory of volcanoes, we have 

 in some measure given also that of earthquakes. 

 They both seem to proceed from the same cause, 

 only with this difference, that the fury of the 

 volcano is spent in the eruption, that of an earth- 

 quake spreads wider, and acts more fatally by 

 being confined. The volcano only affrights a 

 province, earthquakes have laid whole kingdoms 

 in ruin. 



Philosophers * have taken some pains to distin- 

 guish between the various kinds of earthquakes, 

 such as the tremulous, the pulsative, the perpen- 

 dicular, and the inclined; but these are rather 

 the distinctions of art than of nature, mere acci- 

 dental differences, arising from the situation of 

 the country or of the cause. If, for instance, 

 the confined fire acts directly under a province 

 or a town, it will heave the earth perpendicular- 

 ly upward, and produce a perpendicular earth- 

 quake. If it acts at a distance, it will raise that 

 tract obliquely, and thus the inhabitants will per- 

 ceive an inclined one. 



Nor does it seem to me that there is much 

 greater reason for M. Buffon's distinction of earth- 

 quakes, one kind of which he supposes! to be 



* Aristotle, Agiicola, Buffbn. f Buffon, voL ii. p. 328. 



