ON VOLCANOES AND EARTHQUAKES. 377 



and the sea swells and roars, generally undulating in 

 an unusual manner, even without wind. During the 

 commotion, the shocks are generally numerous, suc- 

 ceeding each other with various degrees of rapidity. 

 The earth undulates, heaving and alternately subsiding ; 

 or, in slighter cases, is merely in a tremulous state. 

 In violent earthquakes, it opens ; and, in these fis- 

 sures, which are often of great size, towns and animals 

 are ingulfed. The fissures sometimes emit smoke and 

 flame, sometimes water ; and flame and smoke are also 

 often seen to issue out of the earth, without visible 

 openings, as they do sometimes out of the sea also. 

 The effect of the shocks on the water is remarkable ; 

 ships sometimes feeling the same sensation as if they 

 had struck the ground, or received the blow of a 

 wave. 



The proofs of the connexion between earthquakes 

 and volcanoes are innumerable ; and the latter indeed 

 often appear to give vent to that elastic matter which, 

 being pent up, is the cause of the motion and the 

 tremors of the earth. An earthquake extending to a 

 distance of fifty miles, accompanied the eruption of 

 flames in the sea of Azof which attended the forma- 

 tion of an island ; and the ejection of Sabrina off the 

 Azores, was also marked by the same circumstance. 

 The same occurred when the volcanic islands arose out 

 of the sea on the coast of Iceland. The great earth-- 

 quakes of Sicily and Calabria were accompanied by 

 eruptions of the Lipari Isles ; and those of ^Etria, 

 Vesuvius, and other volcanoes, have equally been 

 attended by earthquakes. Those of Cumana were 

 connected with similar phenomena in the West Indies ; 

 and are supposed to have been dependent on the erup- 

 tions of the Andes. The earthquake of Quito in 1797 

 was marked by an eruption in Guadeloupe ; and the 



