1840.] 



Eeport of the Coal Committee, 



coal it has been customary to use will always have the advantage of a 

 new coal in such trials, in as much as the form of the furnace, and the 

 manner of keeping up the supply will be such as are suited to the old 

 coal, while the necessary experience is wanting with regard to the most 

 favourable circumstances for burning the new. 



If the draught of the furnace be too great for the eoal, the fire will 

 burn down too rapidly, and the coal will be wasted in an unnecessary 

 quantity; and if not sufficient, the fire will burn too slowly, and the 

 stoaker perhaps accustomed to throw in fresh fuel at certain intervals 

 will keep the fire choked, so as to require more frequent stoaking than 

 necessary, and (as Colonel Presgrave remarked on the late trial of Pala- 

 mow coal) every time the door is opened for this purpose, a volume of 

 cold air enters, the effect of which is to lower the steam. 



On board the Jumna steamer, 13th March last, three samples of Pa» 

 lamow coal were tried, one furnished to Mr. Ravenshaw by Cazee Mo- 

 humdeCj mixed however with Chupree coal , and the other two from Mr« 

 Tytler; the first seemed to answer best, though evidently raised with- 

 out judgment, and mixed with shale. The faults of this compared with 

 the best Burdwan coal were, that it required a much larger quantity to 

 keep up steam, and that it ran into slags or clinkers, which choked the 

 bars of the furnace. This last effect may have been owing to the 

 coal being mixed,* and perhaps would not have taken place had the 

 bars of the furnace been wider apart. Mr. Ty tier's sample from Lower 

 Miral appeared to burn very freely, but compared with the best Burd- 

 wan coal, twice the quantity was recjuired to keep up steam. On a 

 third sample from Upper Miral being tried, it was found that even with 

 an excessive consumption of the fuel, it could not keep the engine at 

 full work. The value of these experiments will however depend on 

 two circumstances, namely, whether the samples tried were the best 

 that could be chosen, and whether the furnaces of the Jumna are as well 

 suited to the nature of the coal as any that could be constructed. 



Mr. Ravenshaw thinks he can procure a contract for the supply of 

 Palamow coal at Dinapore for six annas per maund, it would therefore 

 be of some importance to have the question of its quality fairly set at 

 rest. 



• A small quantity of carbonate of lime or soda would have the effect ©f rendering the 

 earthy parts of coal fusible. We think in another trial of Mr. Ravenshaw'3 mixed coal 

 we could easily select the pieces which formed slags from the general mass, as they are 

 covered on the surface with an efflorescence of soda. We think they belong to Singrft 

 one of the Palamow beds, and the peculiarity is probably very local. 



