M i\ Weaver on ihe Structure of the Soui/i of Ireland. 211 



Soc, in May, 1839*; and, Srd, in a paper read before the 

 Geological Society of Dublin, on the 13th June, 1839, the 

 last-mentioned being accompanied by two sections, one re- 

 ferring to the south-eastern portion of the island, and the 

 other to a part of the extreme west, in the count}^ of 

 Kerryf. The views of Mr. Griffith thus appearing in an 

 authenticated form before the public, and the author having 

 in his last production, while attempting to explain his own 

 positions, found it necessary to assail mine, the time has fully 

 arrived for adverting to those views. Being thus put on ray 

 defence, I shall proceed to consider, in connexion, the Outline 

 with its Geological Map, and the three later written communi- 

 cations, with the two sections supplied by the author ; and in so 

 doing, I shall feel no difficulty in showing that many of Mr. 

 Griffith's representations are not only irreconcilable with the 

 facts, but that those representations contradict each other :j;. 



The question at issue lies more particularly between the 

 older stratified rocks of the south of Ireland and the old red 

 sandstone properly so called, which occurs in different por- 

 tions in that quarter of the island. 



In the Outline (at p. 7), Mr. Griffith professes to distinguish 

 the older stratified rocks as consisting of an older and a newer 

 transition series, the latter, which is coloured purple, being 

 said usually to repose unconformably on the former, which 

 is coloured grey ; or, as it is later expressed in another place§, 

 usually resting unconformably on the greywacke slate or Si- 

 lurian series ; and the old red sandstone, which is said to 

 succeed, being distinguished partly by a reddish-brown and 



* Proceedings of the Geological Society, 22nd May, ] 839. 



t Journal of the Geological Society of Dublin, vol. ii. part 1., 1839. 



X This paper was drawn up before I had seen another Geological Map 

 of Ireland put forth by the author, on a large scale, in 1839 "j and to this 

 latter map, it appears, Mr. Griffith's twQ last-mentioned communications 

 refer also in part. If the discrepancies in the map appended to the " Out- 

 line" were startling, the numerous arbitrary alterations introduced in the 

 new map are no less striking; and it may fairly be inquired what reliance 

 is to be placed on either of them, disagreeing largely as they do with each 

 other. I can perceive, in the nev/ map, an approximation in some parts to 

 my own views, but an utter discordance in other parts. As, however, the 

 alterations which have been made ia the new map do not materially inter- 

 fere with the course of my argument, which in the first instance bears di- 

 rectly on the map attached to the "Outline," I have left the text un- 

 changed, merely adding incidentally a few notes in reference to the new 

 map, for the purpose of continuing the comparison. The discrepancies 

 between Mr. Griffith's two maps and my own map of the south of Ireland, 

 will thus become doubly apparent. 



§ Journal of Geol. Soc. of Dublin, vol. ii. p. 85. 



Hodges and Smith, Dublin, and James Gardner, London. 



