ectric and Magnetic Causes of the Earth's rotary Motion. 1 79 



Sicilv and at Palermo, towards which the direction of the 

 motion seemed to be. Lipari lies between us and Stromboli. 

 Since April the parts of our island which were before agitated 

 have been left in repose; but shocks are still frequent at 

 Stromboli, and keep the poor inhabitants there in continual 

 fear. The subterranean furnace seems to have lost much of 

 its power, as the elastic vapours generated there shake but a 

 very limited space, and the new apertures of the mountains 

 emit now and then but a very small quantity of fine sand, which 

 is always the last product of an expiring conflagration. 



From what I have laid down it is just to conclude, that the 

 fires of Eolia are those which have for a long time been pre- 

 paring the event of last INIarch ; that it was produced by mo- 

 tions generated in those mighty furnaces, and that those mo- 

 tions were propagated to great distances. If Sicily then is so 

 often shocked, the powers which agitate it must exist in vol- 

 canos that burn within its own bosom and in the surrounding 

 sea. Situated in the midst of such grand operations of Nature, 

 Sicily must be exposed to all the effects which such power- 

 ful causes are capable of ])roducing. The chemical subter- 

 ranean operations require that the earth should every where 

 be traversed by vast cavities and canals, running in various 

 directions ; and the forces of the operations act on the differ- 

 ent parts of these cavities. But it is natural to believe, and 

 many fiicts in this memoir demonstrate the truth of it, that 

 places in the vicinity of the three gi'eat volcanic outlets ordi- 

 narily feel the force with the greatest violence. In this re- 

 spect the situation of Palermo is very advantageous ; since it 

 is distant from iEtna and from Eolia, and is near to Sciacca 

 only, which is the least energetic. And this grand and re- 

 spectable city would be less exposed to such grievous disasters 

 than all the other cities of Sicily, did its edifices possess that 

 character, which they might easily be made to possess, which 

 constitutes true solidity and firmness. 



XXVII, On Mr. Stuugeon's Suggestion relative to the Elec- 

 tric and Magnetic Causes of the Earth's Motion, and on its 

 Similarity to the Theory of Mr. W. VlERAPAin. By. 

 Mr. J. P. Bevan. 

 To the Editor of the Philosophical Magazine and Journal, 



Sir, 

 |N opening your Magazine for October last, I was struck 

 witii the similarity between some of the observations of 

 Mr. W. Sturgeon in his jjaper on electro-magnetism, pul)- 

 lislied in that Magazine, and those of my fricna Mr. W. V\&- 



Z 2 rapath, 



O 



