LIFE OF JAMES DWIGHT DANA 



a barren waste of lava, which continues up the cone, there, 

 however, composed also of loose cinders and volcanic 

 ashes. This lava is the current of 1822. It was a tedious 

 walk, both because of the steepness of the acclivity and 

 of the yielding nature of the material over which we 

 travelled. In three quarters of an hour we were relieved 

 by arriving on a plain, the principal summit of the moun- 

 tain, near the centre of which was situated a small cone, 

 the present aperture for the smoke and ejected stones and 

 lava. This plain is the old crater, which but four years 

 since was reached by a descent of upwards of two thou- 

 sand feet, the bottom of an ' immense and frightful gulf.' 

 In 1829, a person, when he had reached the summit, 

 stood upon a narrow ridge and could but look down to 

 this seat of volcanic fires. In 1830, the descent was more 

 easy, but it continued nearly the same till the summer 

 of 1832, when it assumed very nearly the form and ap- 

 pearance that it now has. There was at that time a fall- 

 ing in of the wall of the crater, and also, judging from 

 appearances, I should say that the lava as it boiled up 

 had cooled and thus closed all the view to the burning 

 furnace. I have heard it said that the change in its ap- 

 pearance is so great that it can hardly be recognized as 

 the same mountain. At the eruption of 1832 a stream 

 of lava descended the mountain towards Portici. In the 

 description of every eruption that I have read there is 

 noticed some change in the form of the crater. In 1822 

 the walls of it were so much broken off as to lessen the 

 height of the mountain one hundred feet; and thus it 

 appears that, by an examination of its present state, there 

 can be obtained scarcely any idea of the volcano as it 

 was thirty or forty years since. The present circumfer- 

 ence of this plain is nearly four miles, more than twice 

 that of the mouth of the crater in 1830. Part of the old 

 walls exist on the northeast side, and there only. 



As I walked over the plain, rather a rough one, I 

 noticed in the numerous fissures in the lava, on this the 

 western side, that the rocks were heated to redness, 

 within two or three feet of the surface ; and from many 

 places the sulphurous vapors issued freely. These fissures 

 were too shallow to allow any far insight into the interior 

 of the mountain. The volcano at the time was in con- 

 siderable action. The smoke, mostly sulphurous acid, 



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