Irish Volcanoes. 179 



bog-pine they contain, nothing can render them in any sense 

 picturesque. A considerable tract of nearly level ground has 

 been recently gained from the lake, and this, no doubt, takes 

 yet more from its beauty. There are not known in Lough 

 Neagh any remains of those singular lake habitations so 

 common in other parts of Ireland, but some of them are 

 believed to have been constructed on Lough Beg, where the 

 islands are more numerous, and the facilities for such dwellings 

 were perhaps greater. Remains of that curious extinct deer, 

 called the Irish elk, have been found in the neighbourhood. 



The Giant's Causeway is some distance from Lough Neagh, 

 but the basaltic or lava floor is continuous from the lake to the 

 sea. At Portrush we come upon the coast, and though the 

 village is not much above the sea level, the cliffs rise behind 

 it, and on each side to some elevation, and very boldly. A 

 short distance out at sea are several rocky islets known as the 

 Skerries ; these also are capped with basalt. Everywhere there 

 is the same curious phenomenon — a white rocky base of the cliff 

 covered more or less thickly by a gloomy black pall. Here 

 and there only, a few hills of sand and boulders conceal this 

 covering. On the shore, at the bottom of these cliffs, is a 

 singular mixture of dead black and brilliant white pebbles, 

 covered occasionally with fine sand. The structure of the cliffs, 

 the variety of form of the detached and semi-detached blocks, 

 and the numerous examples of pierced rocks, caverns, and 

 broken, jagged, precipitous masses, is extremely striking ; and 

 the whole drive from Portrush to the Causeway, a distance of 

 about eight miles, forms a fit introduction to the wonders of the 

 locality. Dunluce Castle, a mediaeval structure, now in ruins, 

 is about half way ; it is almost detached, and stands out boldly 

 from the main line of the cliff. 



What strikes the observer chiefly at this point is the fact 

 that the white limestone below is separated from the dark 

 rock above by a well-marked line, but that fragments of the 

 white rock appear occasionally in the overlying black mass ; 

 while the black, or basaltic rock, often contains a considerable 

 quantity of chalk, mixed up with and forming part of it. The 

 white limestone, though hard, compact, and splintery, besides 

 having a pinkish colour, is beyond all doubt the geological equi- 

 valent of the chalk of the north and south downs of England. The 

 same admixture of flints, and, above all, the same curious and 

 varied fossil species, are found in both ; but the flints are altered 

 as much as the chalk. Instead of being black, they are more 

 generally red, and indeed are often converted into pure jasper. 

 They are also cracked as if by burning, and look as if they had 

 been re-cemented. Close to the junction of the two rocks, 

 the white and the black, there are bands of red ochre, and a 



VOL. VI. NO. III. N 



