on the 29th of August, 1874. 131 



extends for a length of 3 kilometres, with a width varying from 

 60 to 3 metres. This is set in the direction N. 8° E., and if 

 extended upwards would join on to the central crater of Etna 

 like a sort of ray, which, prolonged downwards to the extreme 

 circumference of the mountain, would meet the old crater of 

 Majo. Besides this principal chasm there are innumerable 

 cracks which seem collateral and radiating from the centres of 

 strong dynamic action. 



2nd. Next to this chasm the principal effect of the eruption is 

 the t new mountain, raised up in a few hours, which constitutes the 

 crater, formed of a regularly shaped heap of blocks and frag- 

 ments of old labradoritic lavas brought up by the shock from 

 the great depths and partly cemented together by the new lava. 

 Then also there are the six groups of small craters, numbering 

 in all thirty-five, which, following the eruption, constitute a 

 system of elevated crater-shaped mounds. 



3rd. The lava, which, besides that forming the crater, and 

 that which is spread over a vast belt in the form of cinders, 

 scoria, and sand, also constitutes two torrents, one 150 metres 

 long, the other 400 metres. 



According to the above measurements of these torrents and of 

 the crater, we find that the following quantity of lava was pro- 

 duced by the eruption : — 



By the first torrent, in cubic metres . . * 18,000 



By the second torrent, „ .... 64,000 



By the crater „ „ .... 1,269,000 



Total mass brought to the surface, in cub. met. 1,351,000 



All this mass occupied a surface of: — 



Eor the first torrent of lava, in square metres . 32,000 

 Second torrent, „ „ „ . 90,000 



Crater „ „ „ „ . 117,734 



Total, in square metres 239,734 



That is; equal in extent to 24 hectares, yet without doing any 

 damage, the soil here being entirely formed of bare rocks. 



If, however, the lava had been able to continue its course, it 

 would soon have come into contact with a wood lying between 

 Randazzo and Lingua Glossa. 



4th. The old lavas, irrupted from strata deep in the earth, 

 consist of a pale-coloured dolerite, and grey and compact augitic 

 labradorite, identical with that which forms part of the backbone 

 of Etna and crops up in the exposed strata or in the banks of the 

 Valle del Bove. The new lava, on the contrary, is more or less 

 full of scoria, of an augitic character and of a black colour, like all 

 modern lavas -, and it often has a metallic lustre. It is also mag- 



K2 



