CENTRAL VOLCANOES. 91 



of them seem to be, as it were, the fiery centres of 

 B volcanic district surrounding them in circles of 

 greater or less extent. They are generally the 

 loftiest peaks of whole groups of craters which are 

 crowded together, and of which one or another has 

 at some time shown signs of activity. Such are 

 called Central Volcanoes. Instances of these are 

 — Vesuvius, being about three thousand eight 

 hundred feet high, and the only volcano that still 

 remains active on the continent of Europe; Etna, 

 which is about ten thousand five hundred feet 

 high; the still loftier Peak of Teyde, in Tene- 

 riffe; the Pico of the Azores; Mowna Roa, in 

 Owyhee, the highest known island mountain, 

 reaching, according to some measurements, to a 

 height of fourteen thousand feet ; the volcano of the 

 Isle of Bourbon, famous for its frequent and 

 mighty outbursts; and several others. Mount 

 Erebus, too, about twelve thousand five hundred 

 feet high, discovered only a few years ago on the 

 Antarctic Ocean, under south latitude 78°, is pro- 

 bably a central volcano. 



In the case of the smaller crater-cones, which 

 surround the central volcano, we know generally 

 of but one outburst of each of them, and that the 

 one to which they owe their origin, and before 

 and after which the volcanic agency has found 

 itself an outlet at some other point more or less 

 distant. Thus, savs Leopold von Buch, the 



