No. III. — Pausiiipo and the Lago (TAgnano. 245 



perhaps be attributed to the circulation of water and vapour 

 ascending from greater depths ; and if this be the case, it may 

 be difficult to arrive at any just notion of the extent of the 

 progressive increase of the heat in the interior of the earth, 

 from observations made at any depth now accessible." On the 

 exciting cause of the caloric requisite for the formation of 

 vapour, &c. it would, in the present state of the investigation^ 

 be premature to speculate. That electricity may be an active^ 

 agent does not seem improbable ; and to a detail of some facts 

 in support of this opinion I may, on some future occasion, al- 

 low myself the pleasure of returning. 



Art. X. — Physical Notices of the Bay of Naples. By James 

 D. Forbes, Esq. Communicated by the Author. 



No. III. — On the District of Pausiiipo and the Lago d^Ag- 



nano. 



" Pausilypi coUes, et Candida Mergeliina, 

 Et myrteta sacris consita littoribus 



Me tibi, terra beata, dico ■ " 



Flaminius. 



\V E have already noticed the great active volcano which forms 

 the leading feature of the Bay of Naples, and the cities which 

 fell a prey to its early ravages. Proceeding now westward, 

 according to our plan in this paper, we shall consider the most 

 prominent features between the hill of Pausiiipo and the ex- 

 tinct crater of Astroni, including the lake Agnano and its in- 

 teresting environs. The succeeding number of these notices 

 I intend to devote to the Solfatara ; the one following to the 

 temple of Serapis at Pozzuoli, and the curious natural facts 

 which it illustrates, and which have so long perplexed natura- 

 lists : I intend next to proceed with an account of the Monte 

 NuovOjLakeAvernus and its vicinity; and lastly, to add a notice 

 upon the Islands of Procida arid Ischia. We may then in a 

 concluding paper, take a view of the ground we have passed 

 over, and the general conclusions which may be drawn from a 

 survey of this interesting district. 



In the meantime, we proceed with the objects of our pre- 



