It is sometimes contended that the day of canals has passed, and henceforward the railway must take their place. But this notion is opposed to the present economic necessities of the world, as well as to the provisions of Nature, which evidently point to the utilization of the hydraulic systems of the globe. The lavish and prodigal use of the coal-deposit of the earth, and the deforesting of vast tracts of soil to supply fuel for the locomotive and the stationary engine, have already wrought incalculable and almost irremediable evils. The past year has seen the prices of all English coals go up at least eighty per cent., and the coal-famine of Great Britain, foreseen some years ago, has already threatened to sap the vigor of her industrial systems and destroy her manufacturing supremacy, or, at any rate, place her at the mercy of the United States for the fuel with which to operate them. The denudation of the vast territories of the United States by the axe of emigration has already told in a marked degree upon the condition of its climate, and greatly affected its meteorology and rainfall; while the railroads, which have spread their Briarean arms over the whole country, by their immense consumption of wood for cross-ties, sills, fuel, snow-sheds, bridges, etc., have wellnigh stripped the land of its timber, leaving its bosom exposed to the biting blasts of winter and to the fiery blaze of the summer sun. The problem of more rapid canal navigation is speedily approaching solution, and to give up the water-lines of the larger sections would be fatal to their commercial development. "The Erie Canal," said a distinguished citizen of New York a short time ago, "now conveys one-fourth of the whole export of that vast interior region I have described (the Mississippi drainage), and as much of it during its six months of uninterrupted navigation as all of the trunk railways together during the same time." "Every canal-boat," he added, "which comes to Albany with an average cargo is more than the average of the New York Central Railroad trains. In the busy canal season more than one hundred and fifty such boats come daily to tide-water, and the New York Central Railroad traffic never reaches thirty trains a day." Such a canal traffic would make more than twenty miles of uninterrupted railroad-cars, which could not, by any possibility, be handled by the largest force of railroad employes with expedition or convenience. The _furore_ which the steam-engine has excited and so long maintained in the mechanical world is decidedly abating. Engineers are everywhere at work studying the practicability of employing new forces. The solar heat, the wind-power, the water-power of rivers, and even the tidal energy of the sea, have been and are now being harnessed to the machineries of Europe. These reservoirs of force are kept perennially full by the sun and the moon, to whose action they are due, and at a