COAL. )) 



in which does not exceed 5 or 6 per cent.; that of the Vl-feet Tindharia 

 seam, which contains 1£ per cent, or so of volatile matter, cakes to a 

 slight degree in the fire. A qualitative analysis of the ash of this coal 

 proved the absence of both sulphur and phosphorus, a most important 

 advantage in the manufacture of iron. 



Mr. Blanford gives assays of coal from seventeen of the Raniganj 

 mines.* The mean of these shows an average composition of free carbon 

 51*09, volatile matter 82'64, ash 16*27. If we assume, as we fairly may, 

 that the Darjiling coal, in its undisturbed state, had about the same 

 composition as the Raniganj, it follows that during and since the eleva- 

 tion and contortion of the former, and its associated beds, the coal has 

 lost on an average more than two-thirds of its volatile matter. The 

 percentages of free carbon and ash are thereby of course increased.f 



The question of whether the Darjiling coal can be profitably de- 

 livered at the terminus of the Northern Bengal 



Mining. . 



State Railway, say at Sukna, may be conveniently 

 discussed under three heads, viz., mining, conveyance of the coal to the 

 foot of the hills, and conversion into a usable form of fuel. 



The high inclination of most of the seams, as well as the softness 

 of the coal, would necessitate a method of mining altogether different 



* Vol. Ill, pt. 1, p. 189. 



f A similar change has been shewn by Prof. H. D. Rogers to have taken place in the 

 coal of the Appalachian field, where the strata are folded up in the Alleghany Mountains. 

 In the western part of the field, where the bedding is level and unbroken, the percentage of 

 volatile matter ranges from 40 to 50 per cent. " Eastward of this, on the Monongahela, 

 it still approaches 40 per cent., where the strata begin to experience some gentle flexures. 

 On entering the Alleghany Mountains, where the distinct anticlinal axes begin to show 

 themselves, but before the dislocations are considerable, the volatile matter is generally 

 in the proportion of 18 or 20 per cent. At length, when we arrive at some insulated 

 coal-fields associated with some of the boldest flexures of the Appalachian chain, where the 

 strata have been actually turned over, as near Pottsville, we find the coal to contain only 

 from 6 to 12 per cent, of bitumen, thus becoming a genuine anthracite," (Lyell's Elements 

 of Geology, sixth edition, p. 499. — Coal containing as much as 12 per cent, of volatile 

 matter can scarcely be considered a true anthracite). 



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