10 
Records of the Geological Survey of India. 
On the other hand the roof is frequently, (hough not always, coarse sandstone. The 
seams are not of even thickness throughout, some, perhaps all, being very variable. Most of 
them are only seen for a few feet, and in only two cases could I trace them the whole distance 
across the river. One so traced varied but slightly in thickness, being about 1 foot to 1 foot 
3 inches; the other was 2 feet thick on one bank of the stream, and gradually thinned away, 
vanishing completely before reaching the other bank, less than 50 yards distant. Both these 
seams were associated with (lags and shales. 
It will thus he seen that, except at Rawundeo, not one seam is known to occur exceed¬ 
ing 3 feet in thickness, and I doubt if any seam of that thickness can he profitably mined in 
India. I am aware that much thinner seams are worked in England, some, I believe, not 
exceeding 18 inches, though that is exceptional. But in England there are three advantages at 
least which are wanting in India. These are—1. A large local demand ; 2. Excellence of 
quality j 3. A skilled mining population. 
In India, in a place like the Tawa Valley, there is no local demand, nor is it very 
probable that there ever will be. The best Indian coal from the Damuda beds is about 
half as good as the best English coal, that is, if used in a, steam engine, for instance, it takes 
twice as much Indian coal to do the same work. The value consequently, weight for 
weight, is about one-half, and a 3 feet seam of Darnuda coal is, on this account alone, only 
an equivalent of an 18 inch seam of English coal. Another disadvantage entailed by the 
inferiority of quality, is of course, increased expense for carriage. 
The want of skilled labour causes more coal to he cut to waste besides largely increasing 
the cost of superintendence. 
Taking all the disadvantages into consideration, my own impression is that from 4 feet 
6 inches to 5 feet is the minimum thickness of a coal seam which can be profitably mined 
in India under ordinary circumstances. In the immediate neighbourhood of a railway, or 
of any other large source of demand, perhaps rather thinner seams might be worked. 
Of course a considerable quantity of coal, some thousands of tons in many cases, may 
be profitably extracted from thinner seams near the surface. 
Of course too, the conditions of the profitable mining of Indian coal depend upon a 
variety of circumstances liable to change. A mining population might gradually spring 
up, the demand for fuel may, and probably will, increase, while other supplies may fail or 
increase in value to such an exent as to raise the price of the article permanently. These other 
supplies, at present, are wood and English coal, either of which may at any time become 
unprocurable. On the other hand, if India ever attains a civilization at all approaching that 
of Europe, it will undoubtedly grow timber for fuel largely, as is done in all other civilized 
countries not rich in coal. At present the principal efforts of the whole Native population of 
India, and of no inconsiderable proportion of the European population, appear to he devoted 
to the destruction of the forests, and it is but fair to say that their labours have been rewarded 
with great success. 
Supposing, however, that seams of 4 feet in thickness could be worked or that two or three 
seams were mined from one shaft, thus diminishing the cost of sinking and of machinery, 
there appears a possibility that the Rawundeo coal might he mined, especially as the 
quality is, in some seams, exceptionally good. But there is still one point which must be 
satisfactorily determined before the seams could he pronounced workable, aud that is the 
question how far the seams can he trusted to he constant in thickness. 
Where merely small sections are seen in the hanks of rivers, not extending frequently 
more than 5 or 6 yards, this question is difficult to answer. Of all the seams seen in the Tawa 
Machna, and Bora streams, the outcrops of not more than 3 or 4 can he traced for 50 yards, 
and out of these few, one in the Tawa dwindles from 2 feet to nothing in that distance, and 
a second at Murdunpoor on the Machna, appears to do the same, and certainly, out of a 
total of barely 3 feet, varies as much as a foot- within 20 yards. Moreover, nothing is more 
common than to find coal seams of variable thickness when their roof consists of coarse sand¬ 
stone ; it appears always to mark slight local unconformity, and denudation of the coal seam 
beneath But in the case of the seam at Rawundeo which is seen to thin out, its irre¬ 
gularity is not due to this cause, the roof being of flaggy sandstone. 
In describing the Eanigunj coal field, l showed that there were two sub-divisions of 
the coal heaving rocks or Damudas, the lower containing numerous coal seams of great size 
