LIFE OF JAMES DWIGHT DANA 



hot springs and vapor baths, yet burn. A mountain, 

 which has ejected such immense quantities of lava as 

 has Vesuvius, must necessarily have a great extent of 

 volcanic fires. If, as says Braccini, and from experiment, 

 the descent to the internal plain, in 1631, was by a rapid 

 declivity of three miles, and consequently its situation 

 was far below the level of the sea, what limits ought to 

 be assigned to the fires which then, as they were latent, 

 must have been far below the plain he reached ? It will 

 not, therefore, require much credulity to believe a radius 

 of six or eight miles necessary to include the fires 

 of Vesuvius, even supposing that there are no others in 

 the neighborhood. But others do exist; and judging of 

 their probable limits by the size of the old crater, is there 

 not reason to believe that they also extend six or eight 

 miles and thus meet those of Vesuvius ? or rather, that 

 there is but one source, one great furnace of which Vesu- 

 vius is the present spiracle ? Whether such is the case or 

 not I would submit to your superior judgment. 



' We passed Stromboli Tuesday evening, June i6th, a 

 more extensive mountain than Vesuvius; its red fiery 

 expirations had more breadth and extended to a greater 

 height, but they were less frequent than those of that 

 volcano, happening not oftener than once in fifteen or 

 twenty minutes. The next day Etna was in sight ; but 

 she gave us not the least evidence of her volcanic charac- 

 ter, except in her external appearance. 



" I hardly know what apology to make for writing an 

 epistle so long and perhaps tedious. But I hope that the 

 interest I supposed might properly be taken in the sub- 

 ject, and my own interest in it, will make further apology 

 unnecessary." 



3/6 



