NOME IV. TUFO. 



389 



Aurora 

 borealis. 



while the smoke in the west and north-east was 

 furrowed by continual flashes of lightning of Lightnings, 

 various colours; this smoke so much resembled 

 a cloud laden with hail, that every body con- 

 ceived it to forebode a violent storm ; the cloud 

 remained in this state the space of four hours, 

 when it was utterly dissipated by the violence of 

 the wind ; the flames continued three days and 

 nights without intermission. 



" On the 12th and 13th, neither flame nor 

 smoke were visible proceeding from the crater; 

 and on the night of the 13th, three quarters of 

 an hour after nine, a weak aurora borealis was 

 distinguished, beginning towards the west, and 

 extending eastward, passing north of Etna; this 

 illumination ceased about eleven o'clock, but 

 re-appeared, in the same position as before, at 

 one in the morning : it then exhibited radii, ap- 

 parently diverging from a centre behind the 

 mountain, and at intervals shone with more 

 splendour than at others; it continued thus visi- 

 }Ie the space of an hour. 



" On the following days the flames increased, 

 he subterranean roarings were loud, and the 

 concussions so violent as to shake the houses ; 

 leeming myself therefore no longer safe so near 



e summit, I removed to Catania. 



e( In the night of the l?th, and throughout Clouds of sand. 



Shocks. 



