VESUVIUS. 191 



the district extending from the Canaries and the Azores, 

 across the whole of the Mediterranean, and into Syria 

 itself, belong to but one great centre of internal action. 

 But it is quite certain that Ischia and Vesuvius are 

 outlets from a single source. 



"While Vesuvius was dormant, resigning for a while 

 its pretensions to be the principal vent of the great 

 Neapolitan volcanic system, Ischia, we have seen, was 

 rent by frequent convulsions. But the time was ap- 

 proachiiig when Vesuvius was to resume its natural 

 functions, and with all the more energy that they had 

 been ibr a while suspended. 



In the year 63 (after -Christ) there occurred a 

 violent convulsion of the earth around Vesuvius, 

 during which much injury was done to neighboring 

 cities, and many lives were lost. From this period 

 shocks of earthquake were felt from time to time for 

 sixteen years. These grew gradually more and more 

 violent, until it began to be evident that the volcanic 

 fires were about to return to their main vent. The 

 obstruction which had so long impeded the exit of the 

 confined matter was not, however, readily removed, and 

 it was only in August of the year 79, after numerous 

 and violent internal throes, that the superincumbent 

 mass was at length hurled forth. Kocks and cinders, 

 lava, sand, and scoriae, were propelled from the crater, 

 and spread many miles on every side of Vesuvius. 



We have an interesting account of the great 



