Volcanos and Earthquakes. 349 



phyry of Chlmhora^o, and if this colossal mountain should be- 

 come an active volcano. At all times, analogous facts have 

 given rise to similar hypotheses. The ancient Greeks, who, 

 like us, attributed earthquakes to the force of elastic fluids, 

 brought forward, in support of their opinion, the total cessation 

 of earthquakes in the island of Euboa, after the opening of a 

 chasm in the Lelantic fields.* 



The intimate connection of earthquakes with volcanos is not 

 less clearly proved by the direction which the former take. 

 With the assistance of a simple instrument (the sismograph) 

 invented by Cacciatore, and erected at Palermo, it was found 

 in twenty- seven cases that the shock was propagated in a fixed 

 linear direction, which coincided remarkably with the cardinal 

 points. In nineteen cases the shocks were transmitted in a di- 

 rection from east to west, corresponding with the situation 

 of Mount Etna, the source of all these subterranean concus- 

 sions, which lies directly to the east of Palermo. In four cases 

 it was from south to north ; but, for want of corresponding ob- 

 servations, the seat of these shocks cannot be determined ; and 

 it certainly does not seem to have been the effect of chance that 

 three shocks, which were felt on the 9th February, 30th June, 

 and 2d July 1831, travelled from the south-west to the north* 

 east : for it was precisely in that direction, at a distance of 

 about 70 Italian miles, that the small new volcano suddenly 

 appeared in the sea, probably on the 2d July. The two latter 

 shocks were also the very same that were felt with greater 

 force at Sciacca, on the southern coast, opposite to the new 

 volcano, t 



On the other hand, Boussingault J asserts that the most me- 

 morable earthquakes in the New World, which ravaged the 

 towns of Latacunga^ Riohamha, Honda, Caraccas, Laguayra, 

 Mcrida, Barquisimeto, &c. do not coincide with any well esta- 

 blished volcanic eruption. The oscillation of the surface, 

 owing to an eruption, is, as it were, local; whilst an earthquake, 

 which is not subject (at least apparently) to any volcanic erup- 

 tion, extends to incredible distances, in which case it has also 



* Strabo, lib. i. ed. Oxon. 1807, t. i p. 85. 



t F. Hoffman in Poggend. Ann. t. xxiv. p. 63. 



X Annal. de Chim. et de Phys. t. Iviii. p. 83. 



