338 



described by bim, Count Montlosier proceeds to show that the 

 Monte Somma Is the true Vesuvius of the ancients, the present 

 volcano being of posterior formation; and he arrives at this conclu- 

 sion by variuus considerations upon the nature and form of Somma, 

 which he supposes to be the remaining segment of a vast elliptical 

 cavity, the other sides of which have since been destroyed. The 

 chief object of the author, however, is to point out the very dif- 

 ferent origin of such a large crateriform hollow as that of the ancient 

 Vesuvius or Somma, which he attributes to explosions, and the small 

 crater of the present Vesuvius, which gives vent to currents of 

 lava. The former having destroyed the towns of Pompeii and Stabiee, 

 with showers of puzzolana and ashes, the latter having overflowed 

 Herculaneum. He endeavours to strengthen this theory by reference 

 to a peculiar class of extinct craters in the Eyfel, in Central France, 

 and in the Phlegrcean fields; the circular hollows of which have since 

 been occupied by small lakes usually of great depth. As none of 

 these have lava-currents issuing from them, and many of them are 

 devoid of marks of igneous alteration, they are considered by the 

 author to be of the same origin as the ancient Vesuvius, i. e. craters 

 formed by sudden explosion. 



Strabo, Pliny, and Dionysius of Halicarnassus,are quoted in proof 

 of the ancient Vesuvius having had the outline of only one moun- 

 tain ; and it is stated that an antique painting, recently discovered 

 at Pompeii, represented the same fact. 



The notice was accompanied by drawings of the supposed form 

 of the Vesuvius of antiquity, before the great eruption under Titus ; 

 of the condition of the mountain after that catastrophe, by which 

 it is presumed that its summit was destroyed and blown away in 

 detritus and puzzolana, leaving an enormous crater; and lastly, of 

 the final state of the mountain, presenting three sides of the an- 

 cient area broken down, with a parasitic cone and crater established 

 on its flank. 



Nov. 30. — Lord Teynham, of Bruton-street ; Alexander Logan, 

 Esq. of Verestreet, Oxford-street; Sir Thomas Winnington, Bart, 

 of Stamford Park, Worcestershire; Thomas Egerton, Esq. of Christ 

 Church Oxford, and Tatton Park, Cheshire; Colonel Wingfield, 

 of Onslow House, near Shrewsbury ; George Stewart Nicholson, 

 Esq. of Robert-street, Adelphi ; W. Long Wrey, Esq. of Thornhill, 

 near Swansea, were elected Fellows of this Society. 



A paper " On the Geology of the Southern Provinces of Spain," 

 by Capt. Edward Cook, R.N. F.G.S., was begun ; and a communi- 

 cation containing extracts from the memoirs published by M. de 

 Buch in the Preussische Staats Zeitung, " On the new volcanic 

 island in the Mediterranean, and its connection with the extinct 

 volcanic island of Pantellaria, and the hot springs of Sciacca on 

 the coast of Sicily," by Leonard Horner, Esq. V.P.G.S. and ad- 

 dressed to the President, was read. 



About twenty-four miles S.E. from the point where Sicily and 

 Africa lie nearest together, is the small island of Pantellaria, almost 

 half way between the two coasts, but rather nearer Africa. It is 



