Vesuvius is, after the Glaciers, the most impressive exhibition of the energies of nature I ever saw. It has not the immeasurable greatness, the overpowering magnificence, nor, above all, the radiant beauty of the glaciers; but it has all their character of tremendous and irresistible strength. From Resina to the hermitage you wind up the mountain, and cross a vast stream of hardened lava, which is an actual image of the waves of the sea, changed into hard black stone by enchantment. The lines of the boiling flood seem to hang in the air, and it is difficult to believe that the billows which seem hurrying down upon you are not actually in motion. This plain was once a sea ofliquid fire. From the hermitage we crossed another vast stream of lava, and then went on foot up the cone - this is the only part of the ascent in which there is any difficulty, and that difficulty has been much exaggerated. It is composed of rocks of lava, and declivities of ashes; by ascending the former and descending the latter, there is very little fatigue. 

On the summit is a kind of irregular plain, the most horrible chaos that can be imagined; riven into ghastly chasms, and heaped up with tumuli of great stones and cinders, and enormous rocks blackened and calcined, which had been thrown from the volcano one upon another in terrible confusion. In the midst stands the conical hill from which volumes of smoke, and the fountains of liquid fire, are rolled forth for ever. The mountain is at present in a slight state of eruption; and a thick heavy white smoke is perpetually rolled out, interrupted by enormous columns of an impenetrable black bituminous vapour, which is hurled up, fold after fold, into the sky with a deep hollow sound, and fiery stones are rained down from its darkness, and a black shower of ashes fell even where we sat. The lava, like the glacier, creeps on perpetually, with a crackling sound as of suppressed fire. There are several springs of lava; and in one place it rushes precipitously over a high crag, rolling down the half-molten rocks and its own overhanging waves; a cataract of quivering fire. We approached the extremity of one of the rivers of lava; it is about twenty feet in breadth and ten in height; and as the inclined plane was not rapid, its motion was very slow. We saw the masses of its dark exterior surface detach themselves as it moved, and betray the depth of the liquid flame. In the day the fire is but slightly seen; you only observe a tremulous motion in the air, and streams and fountains of white sulphurous smoke. 

At length we saw the sun sink between Capreae and Inarime, and, as the darkness increased, the effect of the fire became more beautiful. We were, as it were, surrounded by streams and cataracts of the red and radiant fire; and in the midst, from the column of bituminous smoke shot up into the air, fell the vast masses of rock, white with the light of their intense heat, leaving behind them through the dark vapour trains of splendour. We descended by torch-light, and I should have enjoyed the scenery on my return, but they conducted me, I know not how, to the hermitage in a state of intense bodily suffering.