Irish Volcanoes. 175 



Sicily; 01% at least, there are results of similar volcanic dis- 

 turbances to those which take place at the bottom of the sea 

 near Hecla and Vesuvius, and these are by no means small or 

 unimportant. A tolerably extensive district in the north of 

 Ireland is covered with lava once poured out in a fluid state 

 from yawning crevices in the solid earth. Grand and lofty 

 cliffs owe their grandeur and elevation to the protection 

 afforded by this late, though not last, event in the physical 

 history of the country, and one of the most striking and best 

 known of the picturesque phenomena of Ireland — the Giant's 

 Causeway — is nothing more than a very small fragment of this 

 floor of old volcanic workmanship exhibited under peculiar 

 conditions, and invested with a legendary interest professing 

 to date back to the heroic period when great men were giants, 

 and when giants were supposed able to conquer nature, and 

 perform miracles of strength and intelligence. 



The tourist crossing from Fleetwood or Morecambe to 

 Belfast, and travelling northward or westward by road or rail ; 

 and the navigator sailing round Fairhead on his way into the 

 open Atlantic, are generally little aware that they are crossing 

 a floor of lava as clearly marked and as characteristic as any 

 that have been poured out from the sides of a volcano during 

 the present century. And yet nothing can be more certain ; 

 and there are many places along the coast and in the interior 

 where successive beds of old lava may be seen resting upon 

 the ancient sea bottom of chalk, and where we may study with 

 perfect convenience the effect of the presence of molten rock 

 on a material once identical with the soft chalk of the south- 

 east of England. 



And the scenery of this district is not less picturesque than 

 it is interesting and instructive. Except the corresponding 

 but smaller scenery in the Isle of Skye, on the opposite coast 

 of Scotland, there is nothing at all like it in the British 

 Islands. 



There is indeed no example of columnar basalt so well 

 adapted to show the history of the formation in any part of 

 Europe ; for though in the volcanic districts similar deposits 

 may be made from time to time, they are not visible, since they 

 can only be perfected under a considerable depth of water, 

 producing slow cooling under great pressure. The baths of 

 Bertrich in the Eifel, and some localities on the Rhine near 

 Bonn, are the nearest similar examples. 



To see only the Giant's Causeway, then, is to obtain but a 

 very imperfect notion of the whole of the phenomena. The few 

 acres there exhibited are but a minute fraction of the four or five 

 hundred square miles of lava poured out and spread in thin 

 layers over the chalk of the north-eastern counties of Ireland. 



