of the North of Ireland. 



157 



It may not be improper to subjoin here the series of the rock- 

 measures at two or three of the collieries which I visited in the 

 north of Ireland. I shall first give the provincial names, adding 

 the scientific terms which appear to correspond to them. 



ROCK-MEASURES OF THE MARY ANN PIT, 



IN THE COUNTY OF TYRONE, 



from the surface downwUids. 



I 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



PROVINCIAL TERMS. 



Sandstone 



White -metal . . , . 



Slate 



Craw-coal 



Turbage 



Grey-metal 



Slate 



Bone-coal 



Turbage 



Grey Bind 



Black-measure . . . . 



Grey-metal 



Slate 



Main Seam of Coal 



GEOGNOSTIC NAMES. 



Grey-white clay Ironstone 



Slate-clay 



Slate-coal 



Soft slate-clay 



Reddish brown clayiron-st 

 Slate-clay 



as above ... 



like Sand ? 



Slate-clay. 



FEET. INCHES 



33 



4 



2 



1 



3 

 21 



1 



2 



4 



9 



9 



6 



2 

 5 to 6 



Total 



104 



This account of rock-measures falls short of the depth of the pit 

 itself, by seventy six feet ; and we must either suppose that some of 

 them recur once or twice more in the series, or rather that it is not 

 perfectly correct : my authorities in this and the following table 

 were the miners who attended me as guides. 



