126 CALORIfIC POWER OF FUELS. 



Sulphur. The atomic weights of sulphur and oxygen 

 being as 32 to 16, and sulphurous acid containing I atom of 

 sulphur and 2 atoms of oxygen, we have 



32 : 32 = i : i. 



I kilogram of oxygen occupies 0.699 cubic metre; I kilo- 

 gram of sulphur needs, then, to form sulphurous acid 



i x 0.699 0-699 cubic metre of oxygen. 



As most fuels have some oxygen in their composition, we 

 must deduct this at the rate of 0.699 cubic metre per kilo- 

 gram. 



Then multiplying these results by 4.77 (Table XIV) we 

 obtain the number of cubic metres of air required. 



A similar method of calculation will give 



For one pound of carbon 29.86 cubic feet of oxygen. 



" " " " hydrogen 89.60 " " " 



" " " " sulphur 11.20 " " " 



As an example, take a coal containing 90$ C, 5$ H, 3.5$ 

 O, o.i# N, and 0.5$ S. 



C 0.900 X 1.863 = 1.677 cubic metres. 



H 0.040X5.592=0.224 



S 0.005 X 0.699 = 0.003 



Total oxygen 1 .904 



O 0.035 X 0.699 0.024 



1.880 



i. 880 X 4-77 = 8.967 cubic metres of air per kilogram of 

 coal; or 143.98 cubic feet of air to the pound of coal. 



This result of course is only approximate, as complete 

 combustion is not attained with coal and solid fuels. With 

 liquid fuels, and especially gases, however, the combustion is 

 usually complete. 



