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,[1] 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
- ↑ When Engineers speak of a 25 horse Engine, they mean one which would do the work of that number of horses constantly acting, but supposing that the same horses could work only 8 hours in every 24, there must be 75 horses kept at least to produce the effect of such an Engine.
The largest Engine in Cornwall may, if worked to the full extent, be equal to from 300 to 350 horse power, and would therefore require 1000 horses to be kept to produce the same constant effect. In this way it has been said than an Engine was of 1000 horse power, but this is not according to the usual computation.
Letter from J. Taylor, Esq. to Dr. Buckland.
