838 



THE WONDERS OF GEOLOGY. Lect. VIII. 



Livy informs us that an event of this kind, which took place 

 about the period of the death of Hannibal, together with 

 other volcanic phenomena, so terrified the Roman people, 

 as to induce them to decree a supplication to the gods, to 

 avert the displeasure of heaven, which these prodigies were 

 supposed to denote. " Nuntiatumque erat haud procul Si- 

 cilia insulam quae nunquam ante fuerat novam editam e 

 mari esse." — Livy, lib. xxxix. c. 56. 



In Iceland, which may be regarded as a submarine vol- 

 canic mountain, with the highest summits above the waters, 

 eruptions are not restricted to the area of dry land ; but 

 often burst out in submarine volcanoes off the coasts. The 

 enormous eruptions which issued from three different vents 

 in the low tract called Shaptar Jokul, in 1783, and poured 

 out lava currents many miles wide, and ninety long, was 

 preceded by the appearance of volcanic cones, vomiting 

 flames and vapour, in the neighbouring sea, many miles 

 from the land.* 



A highly interesting example of the emergence of a 

 submarine volcano took place in 1831. A volcanic island 

 suddenly arose in the Mediterranean, about thirty miles off 

 the S. W. coast of Sicily, where previous soundings had ascer- 

 tained the depth of the sea to be 600 feet. It was preceded 

 by a violent spouting up of steam and water, and at length 



* Travels in Iceland, by Sir G. S. Mackenzie. 



It is worthy of remark that there are active volcanoes both in the Arc- 

 tic and Antarctic regions. Sir James Ross observes, that " the earth's 

 crust, as we approach towards the pole in the southern hemisphere, 

 presents the most striking indications of the vast subterranean fires 

 pent up within it, and, as we now find, having vent in both the frigid 

 zones : the volcano of Jan Mayen actively burning within the Arctic 

 Circle ; and Mount Erebus, rising from the lofty mountain range of 

 the newly-discovered continent of Victoria, to an altitude of more 

 than 12,000 feet above the Antarctic Ocean, and sending forth its 

 smoke and flame to the height of 2,000 feet above its crater, the centre 

 of volcanic action in those regions of eternal snow." — Sir J. C. Boss's 

 Voyaye to the Southern Seas, vol. ii. p. 412. 



