Irish Volcanoes. 189 



Causeway, and the nature of the evidence on which we assert 

 that it represents a condition of the earth when the volcanic 

 fires, that have now retreated to Iceland, burnt "fiercely 

 beneath the British Islands. There is, indeed, no great 

 accumulation of ashes or other products indicating a volcanic 

 mountain on land; but submarine volcanoes, such as still burst 

 forth occasionally, are not less real than Etna and Vesuvius. 

 The story enacted thirty years ago in the Mediterranean, 

 between Sicily and the site of old Carthage, will illustrate the 

 nature of the case. There, in water a hundred fathoms deep, 

 ships passing over the surface felt earthquake shocks which 

 extended to the land of Sicily. Columns of water were thrown 

 into the air sixty feet high and half a mile in circumference, 

 columns of steam succeeded them, reaching nearly 2000 feet 

 above the sea level, and at length a solid island appeared. 

 The island grew till it was more than three miles in circum- 

 ference, and ninety feet high ; but very soon it was reduced 

 by the waves, and at length disappeared, and within a few 

 months from the first appearance the whole affair had termi- 

 nated. Perhaps some such history may have belonged to 

 the north-eastern Atlantic, before the ice from the polar land 

 chilled the islands that then existed, or the glaciers and 

 icebergs, loaded with gravel and mud, were caught and stranded 

 on the shoals which were afterwards to be the hills and plains 

 of the British Islands. That there was a time, long after the 

 chalk-mud had been deposited and hardened, when the ocean 

 floor of chalk and flint was rent to admit the passage of molten 

 rock, the Giant's Causeway clearly proves. That this time, 

 though so recent, compared with the formation of many well- 

 known rocks, preceded the epoch of doubtful though vast 

 antiquity, when men and elephants, tigers and rhinoceroses, 

 lived in northern Europe with the beaver and the wolf, the 

 reindeer and the large-horned extinct Irish elk, is equally 

 beyond cavil. Thus the study of the Causeway is an instruc- 

 tive chapter in geological history, and the remains of Irish 

 volcanoes are of some value as records of past events, as well 

 as in their quality of introducing a peculiar rock, and framing 

 some of the most singular scenery on the shores of the British 

 isles. 



