212 Report of the Coal Committee, [No. 98. 



ever 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 coal, 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 inter- 

 vals will keep the fire choked, so as to require more frequent stoak- 

 ing than necessary, and (as Colonel Presgrave remarked on the late 

 trial of Palamow 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 

 Palamow coal were tried, one furnished to Mr. Ravenshaw by Cazee 

 Mohumdee, mixed however with Chupree coal, and the other two 

 from Mr. Tytler ; the first seemed to answer best, though evidently 

 raised without 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. Tytler's 

 sample from Lower Miral appeared to burn very freely, but compared 

 with the best Burdwan coal, twice the quantity was required 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 of rendering 

 the earthy parts of coal fusible. We think in another trial of Mr. Ravenshaw's 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 

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



