ANALYSIS OF CUMBERLAND, FORMOSA, AND JAPAN COAL. 



169 



The carbon and hydrogen were determined hy combustion with oxide of copper, metallic 

 copper, and oxygen gas, by a modification of the method of Dumas and Stass. 



The nitrogen was determined by Dumas' method, and the sulphur by Liebig's method in the 

 dry way. 



Some of the deductions from the analytical results may be stated as follows : 



The most desirable qualities of coal for sea steamers are — 



1st. High heating or evaporative power. 



2d. Compact structure, so that the greatest quantity may be stowed in the smallest space. 



3d. Eeady inflammability and quick action, that steam may be got up easily and quickly. 



4th. Infusibility, or absence of the quality of caking, so that the draught may remain free, 

 and the combustion perfect. 



5th. Freedom from sulphur and other substances injurious to the metal of grate-bars, boilers, 

 and chimneys. 



6th. Small residue after combustion ; and this residue infusible or indisposed to form clinker, 

 so that it may pass the grate-bars with the least possible labor and interference with the com- 

 bustion. 



•7th. Not smoky, so that the fires may be kindled or kept without disclosing the circumstance 

 to an enemy. 



The amount of carbon in a fuel forms the best single indication of its evaporative power, 

 though the hydrogen must give additional value to the fuel that contains it in greatest propor- 

 tion, everything else being equal, because it produces great heat and a long flame. Therefore 

 the 1st of the requisite qualities is deduced from the proportion of these two elements. 



The 2d requisite quality is deduced from the specific gravity. 



The 3d, 4th, and 7th are estimated from separate practical observations. 



The 5th is deduced from the proportion of nitrogen and sulphur. 



The 6th is deduced from the proportion of ash and from separate practical observation. 



The deductions may be tabulated from these data, so as to indicate the comparative value of 

 the coal examined, by the difference in the sum of the advantages calculated per centum. 



1 — 1 

 03 

 3 



-Sj 



:§ a 



H. & 



^ 3 



OJ M 

 ►" !». 



,3 "* 



Cumberland coal has 

 the per-centage ad- 

 vantage over For- 

 mosa. 



Formosa coal has the 

 per-centage advan- 

 tage over Cumber- 

 land. 



Cumberland coal has 

 the per-centage ad- 

 vantage over Ja- 

 pan, (1st variety.) 



Japan coal (1st va- 

 riety) has the per- 

 centage advantage 

 over Cumberland. 



Cumberland coal has 

 the per-centage ad- 

 vantage over Ja- 

 pan, (2d variety.) 



Japan coal (2d va- 

 riety) has the per- 

 centage advantage 

 over Cumberland. 



Cumberland coal 

 would have the per- 

 centage advantage 

 over a mixture of 

 equal proportions 

 of Japan. 



A mixture of equal 

 proportions of Ja- 

 pan coal would 

 have the per-cent- 

 age advantage over 

 Cumberland. 



1 



8.6 



8. 





15.6 

 6. 





38.6 





27.1 





2 







14. 

 2. 

 5. 

 1.4 



4. 



3 



2. 

 1. 

 0.5 



3.7 



1. 







1.5 



4 





15. 



2.7 

 12.8 





8. 

 1.3 

 21.4 





5 











6 







30. . 





7 



2. 





2. 



2. 



















18.6 

 7.2 



7.2 



52.1 

 1. 



1. 



68.6 

 24.4 



24.4 



57.8 

 7.5 



7.5 





11.4 



51.1 



44.2 



50.3 





22 s 



