Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/404

 400 and can only be overcome by those enlarged powers of draining which Coal, and the steam engine, alone supply. It would be quite impossible to procure the fuel necessary for these engines, from any other source than mineral coal.

The importance of Coal should be estimated, not only by the pecuniary value of the metals thus produced, but by their further and more important value when applied to the infinitely varied operations and productions of machinery and of the arts.

It has been calculated that in this country about 15,000 steam engines are daily at work; one of those in Cornwall is said to have the power of a thousand horses, the power of each horse, according to Mr. Watt, being equal to that of five and a half men; supposing the average power of each steam engine to be that of twenty-five horses, we have a total amount of steam power equal to that of about two millions of men. When we consider, that a large proportion of this power is applied to move machinery, and that the amount of work now done by machinery in England, has been supposed to be equivalent to that of between three and four hundred millions of men by direct labour, we are almost astounded at the influence of Coal and Iron and Steam, upon the fate and fortunes of the human race. "It is on the rivers," (says Mr. Webster,) "and the boatman may repose on his oars; it is in highways, and begins to exert itself along the courses of land conveyances; it is at the bottom of mines, a thousand (he might have said, 1800) feet below the earth's surface; it is in the mill, and in the