Chap. XXIII.] cost of mixing. 
473 
The actual cost of winning the ore varies greatly from mine to mine, 
according to the character of the deposit, the 
Cost of mining. methods employed in working it, and the cost 
oi labour. The area concerning which I have the fullest information 
is the Central Provinces, to which the following remarks particularly 
apply, except where otherwise stated. 
In the sort of quarry that can be described as a hole in the ground 
the actual cost per ton is not very much greater than that paid to the 
contractor. The rate paid to the contractor per 1,000 cubic feet of stacked 
and cleaned ore varies from Rs. 30 to Rs. 60 (and sometimes as high as 
Rs. 75), according to the ease with which the ore can be won (the lower 
rates apply to detrital ore and the higher to ore in situ), the distance the 
waste has to be taken to the dumps, and the situation of the deposit 
with relation to labour centres. I am told that it is found by actual 
experiment that the volume occupied by one ton of stacked and cleaned 
ore ranges from about 15 to 19 cubic feet, the commonest values being 16 
and 17 cubic feet. 
Taking 16| cubic feet as an average value, the weight of 1,000 cubic 
feet of ore is about 60 tons, so that the cost per ton of ore works out at 
8 annas to 1 rupee according as the rate paid to the contractor is 
Rs. 30 or Rs. 60 per 1 ,000 cubic feet. To allow for the fact that the propor- 
tion of ore to waste is very variable even in one mine, it is customary on 
some mines to make a further payment of Rs. 5 to Rs. 6 per 1,000 cubic 
feet of the volume of the cavity made in extracting the ore. The addition 
to the cost per ton of ore due to this payment depends of course on what 
proportion of the cavity made was originally occupied by the manganese- 
ore. The most favourable case is that in which practically the whole 
of the mass of rock extracted is good ore. A good average value for 
the specific gravity of Central Provinces ore would be about 4-4 to 4-5. 
Allowing however for a certain amount of interspaces and friable ore 
which may be expected even in the most favourable circumstances, it will 
be preferable to take this figure as 4. One thousand cubic feet of solid ore 
of specific gravity 4 would weigh about 112 tons. Hence in this case the 
amount, if paid, for the volume of cavity made would be equivalent 
to about 1^ anna per ton of ore extracted. As the other extreme we 
might take a case in which only 1 ton of ore per 1.000 cubic feet of cavity 
was obtained. This would be equivalent to an addition of about Rs. 5 to 
Rs. 6 to the cost of extraction of ore per ton. Such ground would not 
of course be worked unless it were necessary as part of the deadwork 
of the mine. Five tons of ore per 1 ,000 cubic feet would be equivalent 
III E 
