NOME IV. TUFO. 



in ancient lava, decomposed and converted into 

 earth*. After passing those and spots, I ascend- 

 ed a hill, from which I clearly distinguished two 

 new currents of lava: the first had flowed 

 w. N. w. of the crater over the flanks of the 

 cone, between the two territories of Bronte and 

 Aderno ; I was assured that the breadth of this 

 stream was a mile, and its length three miles ; it 

 was formed on the 16th and 17th of July, and 

 on the 18th the rate of its progress had so much 

 diminished that it ceased to advance more than 

 a few fathoms. I was unable to approach it, on 

 account of the steepness of the rocks by which 

 it was surrounded. The second stream, which 

 took the direction N. w. by N., was, at its is- 

 suing from the crater, half a mile in breadth ; it 

 spread afterwards so as to become a mile broad, 

 and descending rather in an oblique line down 

 the rapid slope of this part of the cone, divided 

 into different currents, which left between them 



* tf I was obliged to traverse the current of lava, made by the 

 eruption of 1766, the most recent of any which took this direction ; 

 I saw several streams of lava which had crossed others, and which 

 afforded me evident proofs of the fallacy of the conclusions of those 

 who seek to estimate the period of the formation of the beds of lava 

 from the change they have undergone. Some lavas, of earlier date 

 than others, still resist the weather, and present a vitreous and un- 

 altered surface, while the lavas of later date already begin to be 

 covered with vegetation." 



