t)f the North of Mand. X^% 



2. Alluvial Formations* 



At B. Macrevan, in the county of Antrim, half way between 

 Glenevey and Lough Neagh, bituminous wood in disseminated pieces 

 loosely imbedded in a loamy soil has been found. 



Two shafts, each sixty feet deep, were formerly sunk to obtain 

 it, but are now abandoned, the stock being exhausted* I however 

 pfocured some specimens. The wood has evidently retained its 

 fibrous texture, and burns with a vivid flame ; specific gravity 1,124. 



Not far from B. Macrevan, at B. Vorally, in Sandy Bay, there 

 are still remaining on the shore, a few stumps of bituminized wood> 

 the fissures of which are penetrated by silex, and sometimes even 

 lined by quartz crystals. It does not flame, and its specific gravity, 

 from the quartz it contains, amounts to 2,267. 



It was once the general opinion that the waters of the lough had the 

 property of petrifying, and that the quartz contained in the bitumi- 

 nous wood of Sandy Bay had been deposited from them. The ex- 

 periments however, made by Mr. Tennant during his stay at Belfast^ 

 appear to discountenance that belief, since he found no traces of 

 silica whatsoever in the water of the lough. "f 



* On the shore of Belfast Lough i, traces of att anciont forest have been discovered 

 beneath a peat bog. Here a singular phenomenon (first communicated to the Geological 

 Society by Dr. Mac Douncl) occurs, hazel nuts being found, the kernels of wliich ar6 

 often converted into calcareous spar, while the shells remain unaltered. I am not aware 

 that the remains of the elk, so common in the alluvial districts of other parts of Ireland, 

 have yet been found in this quarter. 



+ As this is the oidy pait of Dr. Berger*s notes, in which Lough Neagh is mentioned, I 

 have taken the opportunity of stating some facts concerning it. 



Its height above the level of the sea is 132 feet* 



Its greatest depth between Arboe and Gartrea points nearly in the centre, 45 feet 



Its greatest length from north-west to south-east, 1 9 miles G furlongs. 



Its superfici<il contents 97,775 acres. 



A constant tradition has prevailed in Ireland, at least sinde the days of Oiraldus Cam- 

 brensis, that it owes its origin to some violent convulsion. 



The northern and eastern shores of the lough presents several sandy beaches, in which 

 fine chalcedonic pebbles are found. 



Vol. III. 2 b 



