C 92 ] 



XV. An Account of the Earthquakes 'which occurred in Sicily 

 in March 1823. By Sig. Abate Ferrara, Professor of 

 Natural Philosophy in the University of Catania, Sfc. S^c* 



ON Wednesday the 5th of March 1823, at 26 minutes after 

 5 P. M., Sicily suffered a violent shock of an earthquake. 

 I was standing in the large plain before the palace, in a situa- 

 tion where I was enabled to preserve that tranquillity of mind 

 necessary fbr observation. The first shock was indistinct, 

 but tending from below upwards ; the second was undulatory, 

 but more vigorous, as though a new impulse had been added 

 to the first, doubling its force ; the third was less strong, but 

 of the same nature ; a new exertion of the force rendered the 

 fourth equal on the whole to the second ; the fifth, like the 

 first, had an evident tendency upwards. Their duration was 

 between sixteen and seventeen seconds ; the time was pre- 

 cisely marked by the seconds hand of a watch which I had 

 with me. The direction was from north-east to south-west. 

 Many persons who ran towards me from the south-west at the 

 time of this terrible phaenomenon were opposed by the resist- 

 ance of the earth. The spear of the vane on the top of the 

 new gate connected with the palace, and upon which I fixed 

 my eyes, bowed in that direction, and remained so until the 

 Sunday, when it fell ; it was inclined to the south-west in an 

 angle of 20°. The waters in the great basin of the botanical 

 garden, as was told me by an eye-witness, were urged up in 

 the same direction by the second shock ; and a palm-tree 

 thirty feet high, in the same garden, was seen to bow its long 

 leafless branches alternately to the north-east and south-west, 

 almost to the ground. The clocks in the observatory, which 

 vibrated from north to south and from east to west, were stopped, 

 because the direction of the shock cut obliquely the plane of 

 their respective vibi'ations ; and the weight of one of them 

 broke its crystal. But two small clocks in my chamber kept 

 their motion, as their vibrations were in the direction of the 

 shock. The mercury in the sismometerf preserved in the 

 observatory was put into violent motion, and at the fifth shock 

 it seemed as much agitated as if it were boiling. 



To the west of Palermo, within the mountains, the earth- 

 quake retained little of its power ; since at Morreale, four miles 

 distant, trifling injury only was sustained by the (Benedictine) 

 monastery of S. Castrense, the house of the P. P. Conviventi, 

 and the seminary of the clergy. At Parco, six miles distant, 



* From the Boston Journal of Philosophy and the Arts for Sept. 1824. 

 •j- An instrument, apparently, for the purpose of showing the violence 

 of the shock of an earthquake. — Tb. 



Mary's 



