528 Mr. J. P. Lacaita, on [May 7, 



WEEKLY EVENING MEETING, 



Friday, May 7. 



The Duke of Northumberland, K.G. F.R.S. President, 

 in the Chair. 



James Philip Lacaita, Esq. LL.D. 

 On the late Earthquakes in Southern Italy. 



Southern Italy is celebrated for its delightful climate, its match- 

 less scenery, its great historical associations ; but it has also a less 

 enviable renown ; it is the classic ground of volcanoes and earth- 

 quakes. Etna and Vesuvius are the two most ^active volcanoes in 

 Europe, and terrific earthquakes have often desolated vast districts 

 of the country. 



Though the common origin, to a certain extent, of the agents 

 producing the phenomena of volcanoes and earthquakes is now 

 scarcely questioned, considerable difference of opinion still prevails 

 with regard to the real nature and character of those agents. It 

 is for men of science to determine whether those agents are to be 

 found in the internal heat of the earth which is supposed to arise 

 from a state of fusion ; or in the heat produced by chemical com- 

 binations and changes ; or in the currents of electricity circulating 

 on the earth's crust ; or in any other causes whatsoever. On this 

 vexata qucestio much light will no doubt be thrown before long by 

 the observations made on the spot by Mr. Mallet, the distinguished 

 author of the " Dynamics of Earthquakes," who, on the first news 

 of the late earthquake in Southern Italy in December last, was 

 sent thither by the Royal Society, for the pursuit of scientific 

 enquiry. Without entering, however, into the field of science, the 

 object of tlie speaker was to give the members of the Royal Insti- 

 tution a short account of six great earthquakes, without counting 

 minor ones, which within the memory of man laid waste extensive 

 tracts of the kingdom of Naples and caused great loss of life; 

 and especially of the last earthquake, which took place on the night 

 of Ihe 16th of December, 1857. 



1. On the 5th of February, 1783, at 1 p.m., the Piana di 

 Monteleone, in the province of Calabria Ultra I., was convulsed 

 by a violent shock of earthquake, which in less than two minutes 

 levelled to the ground 109 towns and villages, and buried 32,000 

 out of 166,000 inhabitants under the ruins of their houses. A 



