on the 29th of August, 1874. 129 



300 metres and a diameter of about 100 metres, and a height of 

 50 metres from its base : this, with an inclination of the sides of 

 about 30°, gives us a base of 860 metres circumference ; and 

 the mound occupies therefore an area of 117,734 square metres. 

 This crater, which looks like a new mountain, is formed of a 

 heap of fragments of doleritic and prehistoric labradoritic lavas 

 of a grey colour, which have been brought up from a great 

 depth by the force of the outbreak of modern lava, which seems 

 in parts to have kneaded the other together. It is singular to see 

 all round this new crater for an area of half a kilometre radius, 

 blocks, lumps, and larger or smaller fragments of this prehistoric 

 lava of a clear grey colour scattered about, contrasting with the 

 present lava, which is very black, and with which they seem here 

 and there to be lined ; so that we thus have the lavas of two 

 widely distant epochs brought into contact — one representing an 

 eruption which no man can have witnessed, the other produced 

 by an eruption of today. 



The interior of the crater exhibits the usual funnel-shaped 

 form ; but its depth has no visible limits. We look across a dark 

 cavernous mouth on whose walls may be seen (as far as the light 

 reaches) jutting out strata of lava of various epochs one above 

 another. The structure and origin of this crater are of great 

 scientific interest. 



Moving from this culminating point and following the chasm 

 on which it is placed, we find that for some distance it passes 

 across a stream of lava of uncertain date, but of the past century, 

 for a distance of about half a kilometre. 



Here near the base of the crater the chasm presents a maxi- 

 mum breadth of from 50 to 60 metres ; and here we see ten 

 small craters of some considerable depth, which, placed one after 

 the other, resemble a row of button-holes. Of these, those near- 

 est to the crater are wide abysses 25 or 30 metres in diameter ; 

 the others have a mean diameter of about 10 metres. 



After these ten openings, constituting the first group of small 

 craters, and as we continue to follow the chasm as it grows nar- 

 rower, we find, after a short interval produced by an inequality 

 of the ground, four others near each other, their mean distance 

 from each other being from 2 to 3 metres. Then at a distance 

 of 10 metres further on we find four others in the same proximity 

 to each other as the first four ; and these eight together form a 

 distinct group. 



Another interval of about 50 metres then occurs, the chasm 

 continuing without any further openings until again four other 

 small craters appear very near each other, three being on the 

 principal chasm. The chasm at this point crosses the side of one 

 of the hills called the Fratelli Pii or the Due Pizzi, which con- 



Phil Mag. S. 4. Vol. 49. No. 323. Feb. 1875. K 



