342 MR MILNE ON THE MID-LOTHIAN AND EAST-LOTHIAN COAL-FIELDS. 



of which the extent of the latter bears but a small proportion to that of the former, the calculation is 

 attended with difficulty. Even, however, if we could accurately ascertain the quantity of coal in each 

 individual stratum, it would be wrong to include the whole as available or attainable fuel. Several of 

 these coal-seams, and the best of them, are at some places at such a depth from the surface, as not to 

 be capable of being reached by any means that are either known or likely to be invented. This re- 

 mark is particularly applicable to the " North Greens" Coal, which affords the largest supplies of parrot 

 coal, and which it is probable is, all along the trough of the Esk basin, not less than from 500 to 800 

 fathoms below the surface. It may be safely said, that all the coal of this and other seams which are 

 more than 200 fathoms below the surface, is entirely unattainable. 



According to this view, the uppermost or Brunstain series of coal would all be brought within our cal- 

 culation, as its lowest beds are not nearly so deep as 200 fathoms from the surface. They do not stretch 

 farther south than the great 80 fathom slip, which runs under SherifiFhall pigeon-house and Dalkeith 



Palace, having been all washed away on the south side of that slip. They extend, therefore, in a N. and 



S. direction about four miles, and in an E. and W. direction about three miles, so that, if they had been 

 all horizontal, there would have been twelve square miles of coal. As they are basin-shaped, some addi- 

 tion should be made on that account ; — but on the other hand, as several of them do not run so far as others, 

 a still greater deduction on that account must be made. On the whole, then, it may be not unfairly 

 assumed, that the Brunstain or uppermost series comprises 75 feet or 25 yards of coal, extending over 

 ten square miles. Now 36 cubic yards of coal weighs about 32 tons ; and as there are 3,097,600 

 square yards in a square mile, a square mile of coal, one yard thick, would contain rather more than 

 2 800,000 tons of coal ; — and a square mile of coal 25 yards thick would contain about 7 1 millions of 

 fons- so that the Brunstain group of coals must contain not less than 710 millions of tons. 



From the previous explanations, it is obvious, that it would be much more difficult to calculate the 

 quantity of available coal in the two lower groups of coals. Suppose them all to constitute one seam, 36 

 yards thick, and situated about half-way between the two, — it would, at the deepest part of the Esk 

 basin, viz. at Fisherrow, be about 500 fathoms below the surface, and in the southern parts of the district 

 more than 200 fathoms. It may, therefore, be roughly estimated, that about one-half of these lower 

 coal-seams are altogether unattainable ; —and that instead of calculating their extent at about 100 square 

 miles, we should estimate it at not more than 50 square miles. One square mile of coal 36 yards thick 

 would produce 102 millions of tons, and therefore the two lowermost groups may be supposed to con- 

 tain at least 5000 millions of tons. 



I believe that in such calculations one-half is generally deducted for waste and for deteriorated 



goal ; so that the total quantity of marketable and attainable coals in the Lothians may be estimated at 



about 3000 millions of tons. But from this a deduction must be made for what has been already 

 worked out. What this quantity may be it is very difficult to say ; — but assuming it to be one-fourth, 

 there would be left 2250 millions of tons. The annual home consumption of coal in Great Britain is at 

 present about 30 millions of tons, — so that there is enough in the East- Lothian and Mid-Lothian coal- 

 fields to supply the whole nation, for seventy-five years. 



