14 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



are not solid. It would not include kerosene shale, as this is 

 not employed as a fuel per se, but as a producer of oil or gas, 

 neither would it include asphalt, ozocerite, and such like sub- 

 stances, which cannot be looked upon as fuels. Coal, in a 

 mineralogical sense, must not be confused with coal 

 in a commercial sense, any more than "ore" in a 

 mineralogical sense, which means any metallic mineral, should 

 be confused with "ore" used in the technological sense, which 

 means any mineral or mineral compound from which metals or 

 metallic combinations can be obtained in an economic manner; 

 thus including the gauge, or matrix, as well as the ore proper. 

 A coal seam may be so impure that certain portions of it may 

 not be worth working, in which case only the commercial coal 

 is extracted; unless it is necessary to break down the inferior 

 coal for head room, when, being broken, the lesser price it 

 realises may go towards covering the expense of raising and 

 marketing it. Since coal mining is prosecuted with the object 

 of making money, it must be obvious that when a lessee agrees 

 to extract all the coal, it is understood to mean that quality of 

 coal on which a profit can be made, for it is not a custom of 

 the trade to mine, and place on the market a product for which 

 there is no sale. To force a lessee to mine, and pay a royalty 

 on worthless material, or that which would cost more than the 

 product was worth to clean it, would be shortsighed policy, 

 though it has been tried, for either the lessee would be ruined 

 in time, or else his coal would get such a bad name that his 

 output would be diminished, and, in consequence, the amount 

 of royalty paid per annum. It is neither fair nor equitable to 

 force a lessee to work an unpayable portion of a seam at the 

 expense of the good coal. 



Coals being variable mixtures, do not lend themselves to a 

 strictly scientific classification. What consumers require is 

 some simple method of distinguishing different varieties, 

 typical examples of which are readily recognised, more especi- 

 ally those whose qualities render them valuable for certain 

 purposes, such as gas-making, steaming or coking. So 

 far, there has not been any special attempt to classify Austra- 

 lian coals. Turning to the work done in other countries, 

 classification, whether based on physical characteristics or 

 chemical composition, have neither of them proved satisfac- 

 tory. The term bituminous includes a great variety of coals 

 that require subdividing. If we take the results of proximate 

 analysis, these include impurities which are largely a matter 

 of accident during the formation of the coal. If we take the 

 physical properties of coals, these give no adequate idea of 

 their composition. The classification adopted by the Pennsyl- 

 vanian Geological Survey was based on the fuel ratio, i.e., 



