VOL. LX.] PHILOSOPHICAL TRANSACTIONS. 3 



branching out and extending much farther and deeper than they chose to venture, 

 the cold there being excessive, and a violent wind frequently extinguishing some 

 of their torches. These caverns undoubtedly contained the lava that issued 

 forth and extended quite to Catania. There are many of these subterraneous 

 cavities known, on other parts of Etna. Some of them are made use of as 

 magazines for snow ; the whole island of Sicily and Malta being supplied with 

 this essential article from mount Etna ; many more would doubtless be found, 

 if searched for, particularly near and under the craters, whence great lavas have 

 issued ; as the immense quantities of such matter we see above ground must 

 necessarily suppose very great hollows beneath. 



After having passed the morning of the 25th in these observations, they pro- 

 ceeded through the 2d, or middle region of Etna, called La Selvosa, the woody, 

 than which nothing can be more beautiful. On every side are mountains, or 

 fragments of mountains, that have been thrown up by various ancient explo- 

 sions : some are near as high as mount Vesuvius, one in particular, is little less 

 than one mile in perpendicular height, and 5 in circumference at its basis. 

 They are all more or less covered, even within their craters, as well as the rich 

 valleys between them, with the largest oak, chestnut, and fir trees, he ever saw 

 any where; and indeed it is hence chiefly, that his Sicilian majesty's dock-yards 

 are supplied with timber. As this part of Etna was famous for its timber in the 

 time of the tyrants of Syracusa, and as it requires the great length of time 

 already mentioned before the matter is fit for vegetation, we may conceive the 

 great age of this respectable volcano. The chestnut-trees predominated in the 

 parts through which they passed, and, though of a very great size, are not to be 

 compared to some on another part of the Regione Selvosa, called Carpinetto. 

 It is amazing that trees should flourish in so shallow a soil, for they cannot 

 penetrate deep without meeting with a rock of lava ; and indeed great part of 

 the roots of the large trees are above ground, and have acquired, by the im- 

 pression of the air, a bark like that of their branches. In this part of the 

 mountain are the finest horned cattle in Sicily ; in general the horns of the 

 Sicilian cattle are near twice the size of any they had ever seen ; the cattle them- 

 selves are of the common size. They passed by the lava of the last eruption in 

 the year 1766, which has destroyed above 4 miles square of the beautiful wood 

 abovementioned. The mountain raised by this eruption abounds with sulphur 

 and salts, exactly resembling those of Vesuvius. 



In about 5 hours from the time they had left the convent of St. Nicolo dell' 

 Arena, they arrived at the borders of the 3d region, called La Netta, or Sco- 

 perta, clean, or uncovered, where they found a very sharp air indeed ; so at in 

 the same day. the 4 seasons of the year were sensibly felt on this mountain ; 

 excessive summer heats in the Piemontese, spring and autumn temperature in 



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