GEOLOGICAL SOCIETY OF DUBLIN. 121 



Drumglass and the limestone at Monaghan are geological equivalents, 

 and that the group of shales and sandstones which overlies the Drumglass 

 limestone, and which contains the coal-beds, is the equivalent of the 

 shales and sandstones of the Slievebeagh group, which may also contain 

 coal. If there be 211 yards in thickness of shale and sandstone strata 

 over the limestone in the Slievebeagh mountains, there should be as 

 good a chance of getting the first or lowest bed of coal there as at Drum- 

 glass. I never examined the country in detail with a view to determine 

 this thickness, and am, therefore, not competent to say whether coal is 

 likely to be found there or not ; but it depends on the thickness of the 

 strata of this group existing above the limestone. 



In corroboration of this view, I will state that Colonel Portlock, in his 

 "Geological Survey of Tyrone," &c, made a large collection of fossils. 

 A part of the collection is deposited in the Museum of Irish Industry at 

 Stephen' s-green. Among the plants are Stigmaria, Sigillaria, Lepido- 

 dendron, &c, from the coal districts of Ballycastle and Coal Island. 

 Specimens of Stigmaria, as good as any of those, are to be seen there, 

 from the sandstone of Carnteel, near Monaghan, eight miles to the south- 

 west of Dungannon, in the middle of the country, coloured on the 

 " Map" as calp. Colonel Portlock' s survey appears to have ended before 

 he got so far south as the Slievebeagh mountains. However, in spite 

 of the boundary line drawn at Dungannon, coal plants have been found 

 at both sides of it alike. 



Mr. Griffith in his early life got imbued with a horror of the calp 

 phantom, and in the reports he wrote on the subject of mining he 

 warned proprietors to beware of trying for coal in the calp. In the 

 Report of the Cohnaught Coal District, in a note at bottom of page 9, he 

 says : — "Many fruitless trials have been made in search of coal in dif- 

 ferent parts of the calp country by ignorant miners, who mistook the 

 black slate clay, with which it is interstratified, for the slate clay which 

 forms a principal member in the coal series." 



When a theorist once takes a certain view of a subject in geology, and 

 wishes to make out something new, every fact that appears to support 

 that view is greedily adopted and enlisted into the service, while the 

 facts which tell against it are rejected. Since the period of the disco- 

 very of the calp sandstone at Bundoran by Mr. Griffith, every insulated 

 patch of sandstone in Ireland associated with black shale, which is not 

 clearly below the bottom or above the top of the limestone, has been 

 called calp sandstone. 



The two other calp districts alluded to, with this, comprise together 

 between 1700 and 1800 square miles. This, instead of a barren calp, 

 may possibly, at least a part of it, turn out to be a fertile coal district. I 

 am not, however, so sanguine as to hope there may be coal in all this area : 

 on the contrary, I know there is not ; that a great part of it is the shale 

 which forms the base of the Coal series, and has not sufficient thickness 

 over the limestone to come up to the coal-beds ; but, even if there were 

 coal in one-tenth of the area, see what an effect it would have on the 



VOL. IV. e 



