Ill 



" Though the substance and quality of this coal, in its several 

 strata, are much alike, and it is all indiscriminately used for the 

 same purposes ; yet there is some difference in the colour, form, 

 and texture of the several veins. The exterior parts, which lie 

 nearest to the clay, have a greater mixture of earth, and are ge- 

 nerally of a dark brown, or chocolate colour ; some of them appear 

 like a mass of coal and earth mixed ; others have a laminous tex- 

 ture, but the Iamina3 run in such oblique, waving, and undulating 

 forms, that they bear a strong resemblance to the roots of trees, of 

 which kind, the Doctor says, I have seen some specimens from 

 Lough Neagh, in Ireland, which seem to be the same sort of fossil. 



" There are other veins of this coal, which lie more in the centre 

 of these strata, and abound most in the lowest and thickest bed, 

 the substance of which is more compact and solid : these are as black, 

 and almost as heavy, as pit-coal ; they do not so easily divide into 

 laminae, and seem to be more strongly impregnated with bitumen : 

 these are distinguished by the name of stone coals, and the fire of 

 them is more strong and lasting than that of other veins. 



" But the most remarkable and curious vein, in these strata, is that 

 which they call the wood-coal, or board-coal, from the resemblance 

 which the pieces have to the grain of deal boards. It is sometimes 

 of a chocolate colour, and sometimes of a shining black. The for- 

 mer sort seems to be less impregnated with bitumen, is not solid 

 and heavy, as the latter, and has more the appearance of wood. It 

 lies in straight and even veins, and is frequently dug in pieces, of 

 three or four feet long, and, with proper care, might be taken out 

 of a much greater length. Other pieces of the same kind are found 

 lying upon them, in all directions, but without the least intermix- 

 ture of earth, and without any interstices, except some small cre- 

 vices, by which the pieces are divided from each other, in all di- 

 rections. When it is first dug, and moist, the thin pieces of itwill 

 bend like horn ; but when dry, it loses all its elasticity, and becomes 



