Mr. Richardson on the Composition of Coal. 



411 



TABLE I. 



Species of Coal 



Locality. 



Carbon. 



Hydrogen. 



Azote & Oxygen- 



Ashes. 





Wvlara, 



74 823 

 82S24 

 83-753 

 67-597 

 84-846 

 81-204 

 87-952 

 83-274 



6180 

 5-491 

 5-660 

 5-405 

 5048 

 5-452 

 5-239 

 5171 



5-085 

 10-457 



8 039 

 12-432 



8-430 

 11-923 



5-416 



9-036 



13-912 

 1128 

 2-548 



14 566 

 1-676 

 1-421 

 1-393 

 2-519 







Newcastle, 











TABLE II. 



Species of Coal. 



Locality. 



Quantity of Oxygen neces- 

 sary to the perfect com- 

 bustion of 100 parts of 

 Coal, subtractingtheO xy- 

 gen contained in the Coal. 



Relative quantity ol 

 heat given out by 

 the same weight 

 of Coal— 

 Edinbro=100-00. 



Relative quantity of 

 heat given out by 

 the same volume 

 of Coal— 



Edinbro'=100-00. 







240-1 

 250-5 

 256-4 

 217-6 

 253-9 

 244-0 

 266-7 

 2502 



110-34 

 115 12 

 1 1 7-83 

 10000 

 116-68 

 112-12 

 122-56 

 114-98 



108-99 

 114-15 



117-91 



10000 

 112-07 

 107-78 

 11903 

 111-31 





Lancashire, 









The first table requires no explanation: The second contains, in the first column, that 

 quantity of oxygen which 100 parts of the different coals abstracts from the air for perfect 

 combustion This quantity of oxygen expresses the relative heating power of the different 

 coals, in admitting that the quantity of heat, evolved by a combustible substance is propor- 

 tional to the quantity of oxygen, which is consumed in its perfect combustion. This rela- 

 tion, according to weight and volume, is given in the second and third columns. 



For example, 100 volumes being taken, Lancashire Canel coal gives out a quantity of 

 heat, expressed by 17-91 more than the same volume of the Edinbro' coal : and 100 parts 

 by weight being taken, the former coal surpasses the latter in the heat evolved by the quan- 

 tity expressed by 17-83. 



