COAL FORMATIONS OF THE BRITISH NORTH AMERICAN PROVINCES.
The total area of the Arcadian coal formation is not less than 9000 square miles; but only a small portion of it contains workable coal,— perhaps not more than 2200 square miles.
If we deduct from the above 1000 square miles for faults, trap dikes, and "worked-out" territory, we may estimate the remainder, or about 5000 square miles, as the present available resources of the British coal mines.
The average thickness of the six principal English coal-fields is about 75 feet. Of this amount we may safely estimate two-thirds, or 50 feet, will be available, since the time will come when the seams which are now con sidered too small to "get" will be found workable. We know that seams of the more valuable coal, 12 inches thick, have been worked successfully, as we shall describe further on.
We may calculate the amount of available English coals on this esti mate, and not be wide of the mark. Each foot vertical will yield 1500
tons of coal to the acre ; or 50 feet total thickness will yield 75,000 tons per acre. Thus, 5000 square miles, at 640 acres to the mile, will produce 240,000,000,000 tons ; but how much should be deducted for denudation and small extent of upper seams we cannot determine. We refer to the table on the next page.
In the following table will be found a comparative estimate of the coal resources of the principal coal-producing countries. We have assumed that one-third of the total thickness of the coal-seams is available, and that each foot of coal in vertical thickness will produce 1500 tons of coal per acre, leaving 1613 tons as waste, which will cover the waste of the English miners, but will not cover the general waste.