G. W. Bulman — Drift Coal in Sandstone. 153 



separate beds of cannel occur ; it is only 'portions of seams of ordinary 

 coal which furnish it. 



In Scotland, again, a seam of coal 2 feet thick, and lying between 

 two beds of limestone, has the upper 8 in. cannel (Geology of 

 Neighbourhood of Edinburgh, Surv. Mem. p. 55). 



It seems the natural conclusion to suppose that the two kinds of 

 coal were formed in the same way. 



Cannel coal, again, is found at times resting on an underclay like 

 an ordinary bituminous coal. The well-known " Boghead " cannel, 

 for example, is thus underlaid. And in the sections from the Coal- 

 field of Cape Breton, given by Sir J. W. Dawson, on p. 414 of his 

 Acadian Geology, four seams of cannel coal are given as resting on 

 underclays. The presence of such underclays beneath coal seams 

 is one of the main arguments in favour of the origin of coal in situ ; 

 and however we interpret it in this case, it is suggestive of a com- 

 mon origin for cannel and ordinary coal in some cases at least. 



And as coal and shale are both found in irregular strings and 

 patches in sandstone, so coal is found associated in the same way 

 with beds of shale. Thus we find described in the Survey Memoir 

 of the Yorkshire Coal-field " a section of strings of coal in shale 

 about 1 foot long and 1 inch at the thickest, thinning out towards 

 each end " (p. 579). And on p. 519 of the same Memoir we find the 

 following section showing the same phenomenon in underclay : — 



Feet. Inches. 



Coal 3 6 



Underclay and Coal-veins 8 



Sandy Underclay 1 6 



Sandy Shale 1 9 



Sandstone ... ... ... ... ... 2 



Undei' clay diuA Coal -veins ... ... ... 4 1 



And from this occurrence of veins of coal in underclay to the 

 following section from the same Memoir, where the coal may be 

 said to play the role of " partings " in a bed of underclay, is but 

 a step : 



Feet. Inches. 



Coal 6 



Underclay ... ... 4 1 



. Coal 1|- 



Underclay 2 2 



Coal 4 



Underclay ... ... ... 1 5 



Coal 3 



(High Moor Lane Pit, p. 167.) Between such a section as the 

 above and the average coal-seam, where underclay or other fine- 

 grained rock forms the "partings," the difference is again merely 

 one of degree. 



And similar patches and veins of coal are found not infrequently 

 in limestone. Here, again, is coal obviously of drift origin, and as 

 in the previous cases it is pure, bright, cleaved coal like that of the 

 ordinary seams of the Coal-measures. 



The fragments of coal in limestone lead to the consideration of 

 the coal-seams associated with limestone strata, as in the Lower 

 Carboniferous of Northumberland and Scotland. In Northumber- 



