THE EAHTH. 93 



Kut 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 promontories and islands in another. We 

 have many instances of islands being thus formed in the midst 

 of the sea, which though for a long time barren, have afterwaids 

 become fruitful seats of happiness and industry. 



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

 action of subterraneous fires ; or more slowly, by the deposition 

 of mud, carried down by rivers, and stopped by some accident.' 

 With respect particularly to the first, ancient historians, and 

 modern travellers, give us such accounts as we can have no room 

 to doubt of. Seneca assures us, that in his time the island 

 of Therasia appeared unexpectedly to some mariners, as they 

 were employed in another pursuit. Pliny assures us, that thir- 

 teen islands in the INIediterranean appeared at once emerging 

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

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

 elevation. However, he mentions the island of Hiera, near that 

 of Therasia, as formed by subterraneous explosions ; and adds 

 to his list several others formed in the same manner. In one of 

 which he relates that fish in great abundance were found, and 

 that all those who ate of them died shortly after. 



" On the twenty-fourth of May,' in the year 1707, a slight 

 earthquake was perceived at Santorin ; and the day following, at 

 sun-rising, au object was seen by the inhabitants of that island, 

 at two or three mUes distance at sea, which appeared like a 

 floating rock. Some persons, desirous either of gain, or incited 

 by curiosity, went there, and found, even while they stood upon 

 this rock, that it seemed to rise beneath their feet. They per 

 ceived also, that its surface was covered with pumice-stones ai:d 

 oys^ters, wLicu it had raised from the bottom. Every day after, 

 until the fourteenth of June, this rock seemed considerably to 

 increase ; and then was found to be half a mile round, and about 

 thirty feet above the sea. The earth of which it was composed 

 seemed whitish, with a small proportion of clay. Soon after 

 this the sea again appeared troubled, and streams arose which 



I Buffon, vol, ii. p. 343. 2 Hist, de 1' Acid. an. n(R p. 23. 



