206 THE STORY-BOOK OF SCIENCE 



threw to a prodigious height a column of flames and 

 smoke; then the whole mountain shook, and all the 

 crests that dominated its crater fell into the depths 

 of the volcano. The next day four mountaineers 

 dared to climb to the top of Etna. They found 

 the crater very much enlarged by the f alling-in of the 

 day before : its orifice, which before had measured 

 one league, now measured two. 



"In the meantime, torrents of lava were pouring 

 from all the crevasses of the mountain down upon 

 the plain, destroying houses, forests, and crops. 

 Some leagues from the volcano, on the seacoast, lies 

 Catania, a large town surrounded then by strong 

 walls. Already the liquid fire had devoured several 

 villages, when the stream reached the walls of Ca- 

 tania and spread over the country. There, as if to 

 show its strength to the terrified Catanians, it tore 

 a hill away and transported it some distance ; it lifted 

 in one mass a field planted with vines and let it float 

 for some time, until the green was reduced to char- 

 coal and disappeared. Finally, the fiery stream 

 reached a wide and deep valley. The Catanians be- 

 lieved themselves saved : no doubt the volcano would 

 exhaust its strength by the time it covered the vast 

 basin which the lava had just entered. But what 

 an error of judgment! In the short space of six 

 hours, the valley was filled, and the lava, overflow- 

 ing, advanced straight toward the town in a stream 

 half a league wide and ten meters high. It would 

 have been all over with Catania if, by the luckiest 

 chance, another current, whose direction crossed the 

 first, had not come and struck against the fiery flood 



