Mr. F. Forster's Observations on the South Welsh Coal Basin. 93 



very small proportion to the total quantity worked, but not possessing the 

 property of breaking into cubical pieces, like Newcastle Coal, this small, 

 in the process of working, is generally reduced to powder. The Stone 

 Coal seams, without sustaining any other material alteration in quality, 

 not unfrequently become so soft and tender, for many acres together, as 

 to be fit only for Culm. Stone Coal Culm, from its slow combustion, and 

 the long steady heat it is capable of affording, is well adapted for lime- 

 burning, and large quantities are exported for that purpose ; mixed with 

 Clay, so as to form balls, it is also extensively used in Wales for domes- 

 tic purposes.* 



2d. Free-burning Coal, locally termed " Coking, or Iron-making Coal," 

 also " Glo spagod, or Branching Coal," from a peculiar property hereafter 

 to be described. Under this head, I propose to include all the interme- 

 diate varieties, between Stone Coal and bituminous Coal, the larger 

 fragments of which are capable of being coked, in heaps, although the 

 small or dust, from the Coal being deficient in bitumen, mil not adhere 

 and form Coke. It is inferior in lustre and hardness to Stone Coal ; 

 fracture, variable, in some specimens presenting a great number of very 

 small and brilliant facets ; cleavage, irregular, and at various angles in- 

 tersecting each other, and presenting the peculiar striated surface some- 

 times exhibited by the Newcastle Coal in the vicinity of a Dyke. 

 Many thin bands of carbonaceous matter are interstratified with these 

 seams of freeburning Coal. The proportion of constituent parts include 

 ^ considerable range {see the Table at the end of this paper), but an 

 analysis of the Coal, from one of the most characteristic seams, afforded 

 the following results : — 



Carbon, or Coke, 82 



Volatile Matter, consisting of Gas of very inferior illuminating power, 



and Ammonia (no Coal-tar passing over), 140. 



Incombustible earthy Residuum, in the form of light white Ashes, 3i 



100 



• In the cottages of the peasantry in the counties of Glamorgan and Carmarthen, and 

 more especially in Pembrokeshire, these balls form the principal article of fuel. The Culm 



