Chap. 47.] Formation of new Mountains. 31"] 



fire burfts open its fide, and this is called an eruption. 

 At nrft it emits only a thick fmoke and fhowers ot 

 allies. Thefe are follcnved by red hot (tones, and 

 rocks of a great fize, which are thrown to an immenfe 

 heitrht in the air. Thefe Hones, together with the 

 quantities of aihes difcharged at the fame time, form 

 thole mountains, which cover all the declivities of 

 ./Etna. The fize of them is in proportion to the du- 

 r.uion of the eruption. When it continues a confider- 

 ab:e time, it ibmetimes forms an elevation of one 

 thoufand feet in perpendicular height, which at its 

 bafe is feven or eight miles in circumference. 



' After the formation of the new mountain, the lava 

 commonly burfts out from its lower fide, and, fweep- 

 ing every thing before it, is generally terminated by 

 the fea. Sometimes it iflues from the fide of the 

 mountain, without th.efe attending circumfbnces, 

 v/hich is commonly the cafe with the eruptions of Vo 

 fuvius, in which the elevadon being fo much fmallcr, 

 the melted matter is carried up into the crater, where 

 it is diflcdged without forming any new mountain, but 

 only adding to the height of the old one ; till at length 

 the lava, rifing near the fummit, burfts the fide of the 

 crater. But JEtna being upon a much larger fcale, 

 one crater is not fufikient to give vent to fuch immenfe 

 oceans of liquid fire. 



4 At Nicolofi, which is only twelve miles up the 

 mountain, the climate appears totally changed. When 

 the heats at Catania are infupportable, and the harvcft 

 entirely over, the temperature of the air is moderate 

 at Nicolofi, and in many places the corn quite green. 

 Mr. Brydone, in travelling over JEtna, was (truck 

 with the degree of wijdnefs and ferocity which ap- 

 peared in the inhabitants of the mountain, and which 

 reminded him of an obfervation made by the Padre 

 Y 4 della 



