39 



Griffith also describes a boring made in Sandy Bay, and in a depth 

 of 76 feet there occurred three beds of Lignite, one 25 feet, one 15 

 feet, and one 20 feet thick, giving 60 feet of Lignite, and 16 feet 

 of clay. 



This deposit had been previously described by Dr. Boate in 

 1652, Dr. Molyneux in 1684, and by Barton, in lectures on the 

 Natural History of Lough Neagh, 1757. Subsequently it was fully 

 described by Dr. Scouler, in a paper read before the Geological 

 Society of Dublin, January, 1837. Dr. Scouler, referring to Barton's 

 description of the occurrence of the silicified wood in the Lignite 

 beds opposite Ram's Island, says: — "This stratum of wood is of one 

 uniform mass, and is capable of being cut with a spade. Some- 

 times the wood will not easily break, in that, case it requires the 

 aid of some other wood to separate it from the mass, and may, if 

 properly done, afford a block of two, three, or four hundred pounds, 

 which being carefully examined is found to consist more or less of 

 stone." Here we have the well known silicified wood of Lough 

 Neagh described as occurring in the Lignite of the Tertiary clays. 



Colonel Portlock, in his report on the Geology of Londonderry, 

 Tyrone, and Fermanagh, says: — "In respect to this connection 

 of the basalt with the silicified woods, more evidence is necessary." 



Mr. Gray then described the occurrence of silicified wood in the 

 basalt at Laurencetown, where there is a bed of Lignite in the basalt 

 about 30 feet below the surface, and in this Lignite there are layers of 

 wood charged with silicious matter, and resembling the wood erro- 

 neously supposed to be petrified by the waters of Lough Neagh. 

 The latter is often found quite hard outside, but when broken por- 

 tions of the inside are quite soft and fibrous, like Lignite, and pass 

 from soft wood into compact stone, the semi-silicious portions 

 being almost identical with the hard portions of the Laurence- 

 town Lignite. This fact supplies the evidence Colonel Portlock 

 admitted was wanting. 



The Rev. Dr. Macloskie, in an elaborate paper read before the 

 Natural History and Philosophical Society, in February, 1872, 

 very fully described the silicified wood of Lough Neagh, and after 

 a careful microscopic examination, he states that " in all essential 

 characters it agrees with the wood of the cypress." 



