EARTHQUAKES. 259 



miles.' The eruption which took place in the island of 

 St. Vincent on the 30th of April, 1812, produced sub- 

 terranean noises resembling the loudest peals of thunder 

 in Caraccas, in the plains of Calabozo, and on the banks 

 of the Kio Apure, a distance of upwards of 700 geo- 

 graphical miles. 'This, in respect of distance,' says 

 Humboldt, ' was as if an eruption of Mount Vesuvius 

 were to be heard in the north of France.' 



But it is remarkable that subterranean rumblings 

 and bellowings are sometimes heard when neither an 

 earthquake nor the kindred phenomenon a volcano is 

 in progress. 'Sonorous phenomena,' Humboldt tells 

 us, ' when accompanied by no perceptible shocks, leave 

 a remarkably deep impression even with those who have 

 long dwelt in districts subject to repeated earthquakes.' 

 A singular instance occurred in the year 1784, in the 

 high lands of Mexico. A sound was heard as of heavily 

 rumbling thunder alternating with sharp explosive 

 bursts beneath the feet of the startled inhabitants of 

 Gruanaxato. The subterranean bellowings and thun- 

 derings (bramidos y truenos subterraneos) grew gra- 

 dually more and more intense, and then decreased as 

 gradually. Terrified by a phenomenon which seemed 

 to forewarn them of an approaching and terrible 

 catastrophe, the inhabitants fled from the town, leaving 

 great piles of silver bars a prey to bands of robbers. 

 But after a time the more courageous returned and 

 repossessed themselves of their treasure. For one 

 month the subterranean grumblings were heard at 

 intervals, though neither on the surface of the earth, 



s2 



