REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 37 



quantity of heat absorbed by a unit of pure water when its tem- 

 perature is raised 1° C. Both the gram and the kilogram are used 

 as the unit weights of water. 



An approximation of the result obtained by direct determina- 

 tion in a calorimeter may be obtained from the ultimate analysis 

 of the fuel by the following formula, which gives the value as 

 compared with pui^ carbon. 



V=C+4.25 (H— i O) 

 where 



C=percentage of carbon 



H= " hydrogen 



0= " oxygen 



In this case the amount of carbon, hydrogen and oxygen in the 

 fuel must be known, though the sulfur and nitrogem may be 

 neglected on account of the small amount present in most cases. 

 It will be seen that the only analyses in the tables given above 

 that can be used in calorimetric determinations by this method 

 are those of Irish peat quoted from the Dublin Journal of Indus- 

 trial Progress. Some authors hold that the heat value of a fuel 

 may be determined more accurately by using a proximate 

 analysis; but this is doubtful, though in the case of peat a close 

 approximation might be obtained in dry fuel. If the volatile 

 matter were all marsh gas, the proximate analysis would do as 

 w^ell as the ultimate analysis; but the presence of other volatile 

 matter complicates the computation. Another method of deter- 

 mining the heating power of a fuel is by mixing a given weight 

 of the fuel with a quantity of litharge and heating the mixture in 

 a crucible ; the heating power is in proportion to the quantity of 

 lead reduced. Experiments made by Mr C. Cowper gave the 

 following results.^ 



10 gps. of Newcastle coal 284 grs. lead 



10 " oven coke 302 " 



10 " common peat, Bog of Allen 144 " 



10 " same coked in crucible 259 " 



^Taylor. R. C. Statistics of Coal. Phila. 184S. p. 885. 



