THE EARTH. 55 



we shall never account; and many questions may be asked, which 

 no conjectures can thoroughly resolve. It was the fault of the phi- 

 losophers of the last age, to be more inquisitive after the causes 

 of things than after the things themselves. They seemed to tlunk 

 that a confession of ignorance cancelled their claims to wisdom ; they, 

 therefore, had a solution for every demand. But the present age has 

 grown, if not more inquisitive, at least more modest; and none am 

 now ashamed of that ignorance, which labour can neither remedy nor 



CHAPTER XL 



OF THE APPEARANCE OP NEW ISLANDS AND TRACTS ; AND OP THE 

 DISAPPEARANCE OF OTHERS. 



HITHERTO we have taken a survey only of the evils which are pro 

 duced by subterranean fires, but we have mentioned nothing of th 

 benefits they may possibly produce. They may be of use in warm- 

 ing and cherishing the ground, in promoting vegetation, and giving a 

 more exquisite flavour to the productions of the earth. The imagina- 

 tion of a person who has never been out of our own mild region, can 

 scarcely reach to that luxuriant beauty with which all nature appears 

 clothed in those very countries that we have just now described as 

 desolated by earthquakes, and undermined by subterranean fires. It 

 must be granted, therefore, that though in those regions they have a 

 greater share in the dangers, they have also a larger proportion in the 

 benefits of nature. 



But there is another advantage arising from subterranean fires, 

 which, though hitherto disregarded by man, yet may one day become 

 serviceable to him ; I mean, that while they are found to swallow up 

 cities and plains in one place, they are also known to produce promon- 

 tories and islands in another. VVe have many instances of islands be- 

 ing thus formed in the midst of the sea, which though for a long time 

 barren, have afterwards become fruitful seats of happiness and in- 

 dustry. 



New islands are formed in two ways ; either suddenly, by the ac- 

 tion of subterranean fires ; or more slowly, by the deposition of mud, 

 carried down by rivers, and stopped by some accident.* With re- 

 spect particularly to the first, ancient historians, and modern travellers, 

 give us such accounts as we can have no room to doubt of. Seneca as- 

 sures us, that in his time the island of Therasia appeared unexpected- 

 ly to some mariners, as they were employed in another pursuit. Pliny 

 assures us, that thirteen islands in the Mediterranean appeared at onca 

 emerging from the water ; the cause of which he ascribes rather to 

 the retiring of the sea in those parts, than to any subterraneous eleva- 

 tion. However, he mentions the island of Hiera, near that of Thera- 

 sia. as formed by subterraneous explosions ; and adds to his list several 

 others formed in the same manner. In one of which he relates that 



* BufFon. ol. ii. p. 347. 



