178 



cox. 



Proximate analysis of the coal. 

 [The figures give percentages.] 



Source 

 of tlie coal. 



Methoa of 

 analy.sis. 



Water. 



Volatile 

 combus- 

 tible. 



Fixed 

 carbon. 



Ash. 



Sulphur. 



Australia 



Do 



Official » '. 



do 



2.53 

 2.53 



36.12 

 36.07 



48.99 

 48.96 



12.36 

 12.44 



0.09 









AiKilysis of the coke. 

 [The figures give percentages.] 



No. 



Source of the coal. 



Method of anal.vsis. 



^Tatte""' ^^h- Sulphur. 



1 



2 



Australia 



Official 



79.85 

 79.74 



20.15 1 Trace. 

 20.26 



do 



do - 









» By difference. 



Calorific value of the coke in calories: 



1 2 



6550 6562 



Calculated calorific value of tlie pure coke (free from ash) : 



1 



8209 



2 

 8224 



The latter results corroborate those of Goutal and substantiate his formula for 

 coking coals, that — 



P=82C+ttV where, 

 P=the heating power in calories. 



C=j)ercentage of fixed carbon as determined b}' analysis. 

 V=percentage of volatile combustible, as determined by analysis. 

 «= function of the ratio between the volatile combustible and the total com- 

 bustible matter in the coal, that is : 



per cent of volatile combustible matter 

 100 — (per cent moisture+per cent ash) 



In my previous publication, as was stated, the values for a were given 

 tentativelj', as sufficient data were not available thoroughly to test the 

 accuracy of the formula when applied to coals of these Islands. Atten- 

 tion was called to the fact that greater discrepancies between calculated 

 and determined values were noted in the analyses of Philippine coals than 

 in the ones from which the numbers were calculated. A satisfactory 

 explanation was not then at hand, but it is now believed that these were 

 due to the inaijplicability of the methods of analysis existing at that time, 

 as will be shown below. The numbers were calculated from American 



"Accurate. Cf. This Journal, Sec. A. (1907), 2, 52. 



