to the Mineral Structure of the South of Ireland, 167 



placed one beneath the other, by which means the continuity 

 is broken. 



Suppose the scale of height adopted for a section of a 

 mountainous district be 2000 feet to an inch, and the distance 

 between the termini be 100 miles, on equal scales, the length 

 of such a section would be 22 feet; while by adopting a scale 

 of 8 to 1 for the height, the length would be but 2 feet 9 in., 

 and if carefully constructed the latter would give as clear a re- 

 presentation of the structure of the country as the other. 



In regard to the second point, namely, the accuracy of my 

 sections, Mr. Weaver observes, " that they appear to him in 

 many respects drawn rather according to the conceptions of 

 their author, than the occurrences in nature." This is cer- 

 tainly not complimentary; but as my sections through the 

 same district differ in many important points from those made 

 by Mr. Weaver, I cannot be surprised at the opinion : my 

 consolation is, that should I prove mine to be correct, his 

 opinion of my work will be applicable to his own. 



The part of my section near the east coast to which Mr. 

 Weaver objects, is from the valley of the river Suire to the 

 south coast in the county of Cork ; and first, as he observes, 

 respecting te that part which lies between the valley of the 

 Suire and the vale of Dungarvan, which latter extends west- 

 ward to the Blackwater." 



As far southward as the conglomerate of the Monavoullagh 

 mountains, which rests unconformably on the old clayslate of 

 the county of Waterford, there is no difference of opinion be- 

 tween Mr. Weaver and me ; we both consider the limestone 

 trough of the Suire to be carboniferous limestone, and the red 

 slate and conglomerate to be the old red sandstone ; but Mr. 

 Weaver states that I am incorrect in making the old clayslate 

 to the south of the Suire dip north ; he says, the dip is to the 

 south. Now I have examined the stratification with great care, 

 both previously and subsequently to the publication of his 

 paper, and I must state, that in the line of my section from the 

 hill of Carrick southward by Millvale to Rathcormuck, the ge- 

 neral dip of the cleavage in the old slate series is to the south, 

 but the dip of the strata, as determined by the sedimentary 

 lines 3 is to the northward ; consequently Mr. Weaver in this 

 case must have mistaken cleavage for stratification. It should 

 be observed in this place, that although the slate strata dip 

 towards the north, they are not conformable with the over- 

 lying conglomerate of the valley of the Suire, the latter dip- 

 ping to the north at an angle of 80°, while the ends of the 

 slate beds, where the junction is clearly visible, abut obliquely 

 against the conglomerate, and dip 30° to the west of north 

 at angles varying from 35° to 60°. 



