The Coal Question

Day by day it becomes more evident that the Coal we happily possess in excellent quality and abundance is the mainspring of modern material civilization. As the source of fire, it is the source at once of mechanical motion and of chemical change. Accordingly it is the chief agent in almost every improvement or discovery in the arts which the present age brings forth. It is to us indispensable for domestic purposes, and it has of late years been found to yield a series of organic substances, which puzzle us by their complexity, please us by their beautiful colours, and serve us by their various utility.
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In considering the geological aspects of the question, I endeavour to give some notion of the way in which an estimate of the existing coal is made, and of the degree of certainty attaching to it, deferring to the chapter upon Coal Mining the question of the depth to which we can follow seams of coal. It is shown that in all probability there is no precise physical limit of deep mining, but that the growing difficulties of management and extraction of coal in a very deep mine must greatly enhance its price. It is by this rise of price that gradual exhaustion will be manifested, and its deplorable effects occasioned.
I naturally pass to consider whether there are yet in the cost of coal any present signs of exhaustion; it appears that there has been no recent rise of importance, but that, at the same time, the high price demanded for coals drawn from some of the deepest pits indicates the high price that must in time be demanded for even ordinary coals.

Published in: London by Macmillan and Co., 1866. (Second edition, revised)
Available from: The Library of Economics & Liberty
Also available from: Encyclopedia of Earth (e-book)