25* 



Practical Notes on Burdwan Coal. 



[No. 4. 



Total Cyclostoniiclse, Genera, 

 „ „ Species, 



Helicidse Genera, 

 „ Species, 



Auriculidse. Genera, 

 „ Species, 



June 8th, 1857. 



Grand Total, 



9 

 31 



5> 



31 



10 





60 





j> 



60 



2 





3 







3 





.. 





94 



Practical Notes on the best mode of obtaining the highest duty 

 from Burdwan Coal as compared with English Coal. — By Henry 



PlDDINGTON. 



1. I assume in this paper that the coal supplied is the average 

 good Burdwan Coal ; for there can be no doubt that a great deal of 

 inferior, shaly, stuff has been from time to time sold as Burdwan 

 Coal, and hence, and from the cause which I shall subsequently 

 indicate, arises its bad reputation amongst engineers. I assume also 

 that the boiler furnace is one with "joggle bars." 



2. Perfectly pure coal should contain no earthy matter whatso- 

 ever, but this is rarely, perhaps never, met with. Good English Pit 

 Coal contains from 8.00 to 0.8 per cent, of earthy matter ; the aver- 

 age of such as has been examined here being 2.8 per cent, and the 

 Welsh Steam Coal 2.0 per cent. An average of several analyses of 

 good Burdwan Coal gives from 12 to 15 per cent, as the proportion 

 of earthy matters ; so that we have 



English Pit-Coal. Best Welsh Steam Coal. Burdwan Coal. 

 2.8 pr. ct. 2.0 pr. ct. 13| pr. ct. 



3. I do not refer here to the iron and sulphur, of which most 

 coal contains varying proportions; because I am not so much writ- 

 ing a chemical as a practical paper, and while the iron on the one 

 hand is usually included in the earthy matters, the Burdwan Coal 

 on the other does not contain much sulphur. 



