276 [Proc. B.N.F.C, 



Margie. The archaeologists of the party were loth to leave 

 this interesting spot, but, as the geologists, botanists, and 

 zoologists were anxious to reach Fair Head, the whistle sum- 

 moned us to remount the vehicles and proceed to our ultimate 

 destination, and about half an hour's drive brought us to the 

 farms where the brakes must perforce be abandoned and the 

 remainder of the ascent accomplished on foot. Here we are 

 in close proximity to Lough-na-Cranagh, one of the glacier- 

 formed lakes of the headland, and while some of ' the 

 botanists proceeded thither in search of rare specimens, we 

 viewed the placid waters *of the lake, in the midst of which 

 rises a crannog or artificial island, one of the most perfect 

 examples known to exist in this country of these dwelling- 

 places of primitive man, though believed to have been in- 

 habited well down into the historic period. After a short halt 

 the ascent of the headland was resumed, the various marshes 

 circumscribed, the numerous difficulties of the path safely 

 negotiated, till we stood on the top of Fair Head, gazing down 

 on the sea 600 feet below, and admiring the view displayed 

 from its summit. A short time was devoted to the rearrange- 

 ment of lunch-carrying, after which Mr. Wm. Gray, M.R.I. A., 

 described the various features of the district, saying that the 

 place where we stood was, geologically speaking, the most 

 remarkable spot in Ireland. Fair Head is an intrusive sheet 

 of dolerite, or coarse-grained basalt, which penetrated among 

 the Carboniferous and Mesozoic rocks during a period of vol- 

 canic activity, and in the immediate vicinity are to be found 

 representations of many ages of rock formations. Some of 

 the oldest of the Irish rocks are to be found in Knocklayd, 

 while near at hand are to be seen Carboniferous sandstone 

 containing thick sandstones, shales, coal seams, thin lime- 

 stones, and ironstones ; together with schists, gneiss, and Liassic 

 rocks. The face of Fair Head presents a perpendicular cliflf 

 of 400 feet high, which is gradually being weathered away, 

 and at its foot is a talus, rising about 200 feet above sea level, 

 composed of blocks broken from its face. None of the mem- 

 bers attempted the descent of the head (practicable by the 



