1857.] Practical Notes on Burdwan Coal. 255 



4. Again : every engineer knows that some coal contains too 

 large a proportion of gaseous matter and too little carbon (coke) ; so 

 that though it will light and flame up easily, and thereby raise the 

 steam quickly, yet it does not leave a good bed of glowing coke to 

 keep it up steadily for a long time, and is thus both a wasteful and 

 so to say an uncertain coal ; wasteful because it burns away too 

 fast, and uncertain as giving at one time too much steam and ano- 

 ther too little. And moreover an improper coal for sea-going Steam- 

 ers as they can only carry a given quantity. 



5. The opposite kind, where there is too little gas and too much 

 carbon, raises steam slowly and is apt to coke and clinker and the 

 fire to get slack, for it then approaches to a coke or anthracite fire 

 in a coal furnace. And thus the steam is apt to get low. 



6. Again as to the earthy matter. Up to a small per centage, 

 say perhaps 5 per cent, it does not do harm when burnt in coal, 

 though it tells heavily in the coke, and it perhaps keeps the coal toge- 

 ther while burning; but being incombustible itself, if this proportion 

 is exceeded, the burning of the coal is to a certain extent impeded, 

 and the coal clinkers very much, so as to require constant, and to 

 the firemen, fatiguing attention. And there is much waste in the 

 clinker which, when examined, will be usually found to contain a 

 considerable proportion of coke in the cinder. 



7. The gaseous contents of coal and its carbon are also to be 

 considered, and here we have from the same authority as before. 



Gaseous. Carbon. 



English Pit Coal, 31.00 .... 67.3 



Welsh Coal, 29.25 .... 68.75 



Burdwan Coal, 36.2 50.2 



We have therefore in the Burdwan Coal an excess of gaseous 

 matter and a deficiency of about 18 per cent, of carbon (coke) of 

 which 13^ per cent, is made up by earthy matter and the remainder 

 by water, of which it usually contains from 4 to 8 per cent. 



8. We build Steamers, such as they are, in India ; but their 

 machinery is sent out from England, where the engineers and 

 boiler-makers have no idea of these peculiarities in our Indian Coal, 

 and of course construct their furnaces for burning English Coal, 

 and as our officers and engineers know little or nothing also of 



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