FIRE-CLAY AND ANTHRACITE. 317 



Anthracite is a natural coke. From its position in the 

 earth, and its relations to bituminous coal, as well as from 

 its composition, we are justified in regarding it as a coal 

 that was originally bituminous, but which has been altered 

 by heat, acting under great pressure. In the great coal- 

 field of South Wales, to which we must look for our main 

 supply of anthracite, we are able to trace the action of heat 

 in producing a whole series of different classes of coal in a 

 single seam, which at one part is highly bituminous soft, 

 flaming coal, like the Wallsend, then it becomes harder and 

 less bituminous, then semi-bituminous "stenm coal," then 

 less and less flaming, until at last we have the hard, shiny 

 form of purely carbonaceous coal, that may be handled 

 without soiling the fingers, and which burns without flame, 

 like coke or charcoal. This change proceeds as the seam 

 extends from the east towards the west. In some places 

 the coal at the base of a hill may be anthracite, while that 

 en the outcrop above it may be bituminous. 



An artificial anthracite may be made by heating coal in 

 a closed vessel of sufficient strength to resist the expan- 

 sion of the gases that are formed. It differs from coke in 

 being compact, is not porous, and therefore, of course, 

 much denser, a given weight occupying less space. 



That we Englishmen should be about the last of all the 

 coal-using peoples to apply anthracite to domestic purposes 

 is a very curious fact, but so it is. In America it is the 

 ordinary fuel, and this is the case in all other countries 

 where it is obtainable at the price of bituminous coal. Our 

 perversity in this respect shows out the more strikingly 

 when we go a little further into the subject by comparing 

 the two classes of coal in reference to our methods of using 

 them, and when we consider the fact that our South Wales 

 anthracite is far superior to the American. 



Our open fires only do their small fraction of useful work 

 by radiation. Their convection is all up the chimney. 

 Such being the case, and we being theoretically regarded as 

 rational beings, it might be supposed that for our national 

 and especially radiating fireplaces we should have selected 

 a coal of especial radiating efficiency, but, instead of this, 

 we do the opposite. The flaming coal is just that which 



