If it should be objected that this computation includes the surface of the ocean and uninhabitable regions of the earth, where this power could not be applied for our purposes, Mr. Etzler is quick with his reply—“But, you will recollect,” says he, “that I have promised to show the means for rendering the ocean as inhabitable as the most fruitful dry land; and I do not exclude even the polar regions.” The reader will observe that our author uses the fence only as a convenient formula for expressing the power of the wind, and does not consider it a necessary method of its application. We do not attach much value to this statement of the comparative power of the wind and horse, for no common ground is mentioned on which they can be compared. Undoubtedly, each is incomparably excellent in its way, and every general comparison made for such practical purposes as are contemplated, which gives a preference to the one, must be made with some unfairness to the other. The scientific tables are, for the most part, true only in a tabular sense. We suspect that a loaded wagon, with a light sail, ten feet square, would not have been blown so far by the end of the year, under equal circumstances, as a common racer or dray horse would have drawn it. And how many crazy structures on our globe’s surface, of the same dimensions, would wait for dry-rot if the traces of one horse were hitched to them, even to their windward side? Plainly, this is not the principle of comparison. But even the steady and constant force of the horse may be rated as equal to his weight at least. Yet we should prefer to let the zephyrs and gales bear, with all their weight, upon our fences, than that Dobbin, with feet braced, should lean ominously against them for a season. Nevertheless, here is an almost incalculable power at our disposal, yet how trifling the use we make of it. It only serves to turn a few mills, blow a few vessels across the ocean, and a few trivial ends besides. What a poor compliment do we pay to our indefatigable and energetic servant! “If you ask, perhaps, why this power is not used, if the statement be true, I have to ask in return, why is the power of steam so lately come to application? so many millions of men boiled water every day for many thousand years; they must have frequently seen that boiling water, in tightly closed pots or kettles, would lift the cover or burst the vessel with great violence. The power of steam was, therefore, as commonly known down to the least kitchen or wash-woman, as the power of wind; but close observation and reflection were bestowed neither on the one nor the other.”