176 Vvoi. Y>iVVii\\\ a AccoiuU q/' the Earthquakes 



for these spring from a complication of causes; from the soil, 

 its greater or less capacity of receiving and communicating 

 motion, from the manner in which it presents itself to the pro- 

 gressive motion, and from the state of the edifices. These 

 circumstances may sometimes produce anomalies which easily 

 deceive those who do not bestow in the examination of them 

 the attention which they deserve: but without fear of error I 

 may say, that in general the shock was much the most forcible 

 on the northern shore, and at a little distance from it; and 

 that it went on gradually diminishing towards the interior. The 

 moving force, then, must have been in operation somewhere 

 under the sea opposite this part of the island. Naso was al- 

 most entirely ruined ; Patti, and all the towns about Capes 

 Orlando and Calava, and which are nearer Eolia, were consi- 

 derably damaged. Some very small thinly inhabited towns 

 lost little, because they had little to lose; others were in some 

 measure defended by their situations. Palermo, at the bottom 

 of a bay which curves towards these burning islands, and sur- 

 rounded by large and high mountains on the other side, was 

 exposed to the whole force of the motion against it : this it 

 was, together with the degraded state of its buildings, which 

 brought such ruin upon this beautiful city. Every thing 

 seemed then to announce to us that the most expansive va- 

 pours which proceed from the burning furnaces of Eolia, in 

 developing their immense volumes, urged against the sides of 

 those cavities which once contained the matter of which all 

 these islands are formed, produced the motion that struck 

 obliquely against Sicily, and moving along the siiore towards 

 the west, spread despair throughout Palermo. After the shock 

 of the 5th, their motion was more free ; and they were heard 

 murmuring under the soil near our island, seeking an outlet 

 from the obscure caverns in which they were generated, but 

 not propagating their motion to any considerable distance. 

 The course of that of the 7th was in the same direction with 

 that of the 5th; but that of the 31st was in a direction di- 

 rectly opposite ; since it was felt at Messina, and not at Pa- 

 lermo. The undulations were determined by the horizontal 

 direction of the motion ; the perpendicular shocks, by a force 

 acting from below upwards, which supposes a much greater 

 depth in the situation of the acting force than the other, with- 

 out ever being in any case nearer the surface. Every one 

 may easily distinguish the difference which subsists between 

 the superficial motion caused by the rapid passing of a heavy 

 carriage, or by the sudden combustion of a large quantity of 

 confined gunpowder, which would cause the darting of a large 

 accumulation of electric fluid to restore the equilibrium be- 

 tween 



