130 Prof. O. Silvestri on the Eruption of Etna 



sist of solid lava, and the hill has in consequence been split up 

 in various directions ; and here again one of the eruptive open- 

 ings occurs slightly lateral to the principal chasm. These four 

 last small craters form a third group. The diameter of the open- 

 ing of the second and third groups varies from 1 to 3 metres. 



Following the chasm thus far from the crater (that is, for the 

 length of half a kilometre), we find in this way twenty-two 

 eruptive openings, placed along a line in three groups, existing 

 on a nearly flat surface, the mean elevation of which above the 

 sea is 2440 metres, which is now covered with fragments of old 

 lava and with cinders and scoria from the new lava. 



Proceeding from this flat ground, which seems a sort of table- 

 land, towards the north, we meet with a declivity at an angle of 

 13 to 14 degrees, formed by the great current of solid lava of the 

 year 1614. This is full of numerous and recent cracks, and in 

 some parts is completely broken up by the various earthquakes 

 which have taken place. Still we can trace the continuation of 

 the principal chasm through it, and in this continuation for a 

 distance of about 600 metres there are no openings caused by a 

 more active volcanic force; but at an elevation of 2170 metres 

 we find a fourth group of five small craters from 2 to 3 metres 

 in diameter and of an unknown depth, from which a torrent of 

 lava has escaped which has flowed down to a distance of 150 

 metres with an average width of 60 metres, and having a thick- 

 ness of 2 metres. This lava-stream, following the inclination of 

 the ground, has flowed towards a branch of the lava of 1809, 

 which, standing out prominently, has checked it ; and it has then 

 spread itself out at the base but without passing beyond it. The 

 chasm, however, crosses it, and continues thence downwards 

 through the aforesaid great current of 1614 for another half 

 kilometre ; in this distance appears a fifth group of three small 

 craters at 2150 metres elevation. This is the most active group 

 of all, as it has sent forth a lava-stream about 400 metres in 

 length, 80 in average width, and 2 in thickness ; and this forms 

 two short branches deviating towards the west. 



Finally, the last portion of the chasm in a length of about 50 

 metres presents a sixth and last group of five craters very near 

 together, from 1 to 4 metres in diameter, which have emitted a 

 large quantity of cinder and some fragments of scoria. This 

 sixth group of craters marks the lower limit of the chasm visible 

 on the surface of the soil, this point being at 2030 metres 

 above the level of the sea, 12 kilometres distant. 



To sum up what has been said, we have : — 



1st. The most remarkable rent in the ground, extending from 

 the lower edge of the new crater in the form of a principal chasm 

 slightly tortuous in direction, the most important part of which 



