160 Analysis of Scientific Boohs and Memoirs. 



After the shock of the 5th, the black clouds which covered the heavens 

 on the north and west, formed a dark band, measuring from the zenith 

 towards the horizon 60°, and extending from north to south. It was ter- 

 minated at its base by a circular line, passing from north to south, through 

 the west, and elevated at the southern part about 30° above the horizon. 

 The sky itself was very clear, and its extreme brightness was increased by 

 the contrast with the dark band above, and by the sun just on the point of 

 setting. A little below the band were two other lines, parallel and perfectly 

 regular. This mysterious appearance inspired with fear the minds of the 

 people, who are always seeking in the heavens for signs of future events. 

 But it prepared a tempestuous night, which followed, with torrents of rain, 

 with thunder, snow, hail, and wind.* 



ries, and sometimes even three, and not with much solidity. Since the middle of 

 the last century, the excellent materials afforded them by jEtna, the good method and 

 prudent regulation of the stories, have promised long duration to this city. It may 

 possibly be injured, but cannot be easily ruined, although at the foot of the most 

 formidable volcano in the world. A fter the catastrophe of the 5th of March in Pa- 

 lermo, the lieutenant, the pretor, senators, and police exerted all their zeal. They 

 obliged proprietors to prop up their houses within twenty-four hours ; or to demo- 

 lish them if they were not susceptible of propping. The senate took upon themselves 

 the charge of repairing the houses of poor proprietors, together with the expences. 



" In all times, signs have been mentioned as announcing earthquakes near at 

 hand. People read them in the air and upon the earth ; and some philosophers 

 even have given them credence. The frequent occurrence of these signs, without 

 the expected phenomena, is a sufficient argument against them. But less uncertain 

 are those which accompany the phenomena, as rain and thunder. To that of 1C93 

 such fearful storms succeeded, that, for many hours, at Catania, the groans and 

 voices of the miserable wretches buried under the ruins, were drowned by the roar- 

 ing of the torrents of rain and the tremendous thunders. The same circumstances 

 took place at Calabria in 1783 ; and we were witnesses of the same on the night of 

 die 5th of March. An extraordinary quantity of electric fluid is developed, and 

 being conducted from the deep cavities of the earth to the surface, by the force of 

 equilibrium, produces there extraordinary vaporization, when hygrometers have 

 shown extreme dryness. The atmosphere, charged beyond measure with vapours, 

 will give room to their decomposition, which changes them into vesicles, and then 

 into rain. Fiery meteors will be produced by the electric fluid, liberated by the 

 passage of the vapours to water. If hydrogen gas escape from the earth, it may be 

 inflamed by the electric spark, and present the appearance of fires. I should men- 

 tion here, that, in yolcanic regions, signs may sometimes precede earthquakes ; but 

 this happens from the proximity of the place of the subterranean operations to 

 the surface of the earth, which circumstance connects the internal phenomena with 

 those of the adjacent atmosphere. On the morning of the 8th of March 16G9, at 

 Pidara, a town on the side of jEtna, the air became obscure, as by a partial eclipse 

 of the sun; soon after the earth began to shake, and continued so until the 11th, 

 when an immense fissure opened near Nicolosi, a neighbouring town, a sparkling 

 light appeared over the fissure ; and, on that very day, while the terrible shocks were 

 levelling Nicolosi with the ground, an enormous burning river, amidst herrid rum- 

 blings, roarings, and explosions, was belched out, which flowed fifteen miles, cover- 

 ing a great extent of land, and for four months spreading terror over Sicily— J?or. 

 <lc. inc. JEtn.—Fcrr, Dcscr. dell JElna. 



