MESSRS. EDITORS—The SCIENTIFIC AMERICAN stands deservedly high. I have every volume but the first, carefully bound, and for reference it is invaluable. I therefore feel a pride in having it put forth sound opinions and facts, that will bear reference hereafter. When I saw your article recommending in effect the abandonment of the Erie Canal, it astonished me—it " smelt of the shop." New York city owes its immense growth and wealth to the Erie Canal; "yet the most active opposition to this grandest work of the present century has been, and yet continues, from that very city. Such glaring stupidity should not be supported by the SCIENTIFIC AMERICAN. In your remarks on my article in No. 38, you change your position of abandonment of this canal, and say that the statements and conclusions of the friends of the canal are contradictory when they ask a tax on railroads for the benefit of this canal, and " their logic and sense of justice are very different from ours." The friends of the canal never claimed that it would construct itself from its earnings before it was made. They do claim that it will refund every dollar of its cost within a short comparative period, and ever after save the people of this State from taxation for the support of government, and furnish beside a vast fund for benevolent purposes. For the purpose of raising funds to enlarge this canal, the State claimed the -rijht to toll property passing from the West to tide-water; and when grants for railroads were given, it was stipulated that they should not carry freight, because it was foreseen that they might destroy this source of revenue while the canal, in its unfinished state, could not compete with them. Railroads were, however, subsequent, ly allowed to carry freight, by paying the same tolls the boatmen navigating the canal paid. Not satisfied with this, the railroad made another attack on the poor boatmel and the canal revenues, and obtained a release from paying tolls at all. The boatmen were ruined under this one-sided competition, and the completion of the canal suspended for want of funds; and in this sad position the SCIENTIFIC AMERICAN and New York city propose to abandon the canal altogether. Better counsels prevailed, and the boot is being rapidly placed- on the right foot. The people, not quite so stupid as the city, decided to complete the canal. The railroad influence, backed by Albany and New York city, prevented tolls being placed on railroads, but it was unable to prevent a partial completion and a reduction of tolls for the aid of the poor boatmen. The result begins to be manifest; the canal has now six feet of water, and boats carrying 160 tuns, or 1,600 barrels of flour, now pass from Buffalo to New York, and carry freight (paying tolls) at a rate that railroads can't touch it without tolls—and the poor boatmen are again doing a profitable business. When the canal has seven feet of water, and boats propelled by steam carry 240 tuns, a further great reduction will then be made; and if railroads cannot now compete, what will be their position then ? Would you ask the abandonment of the canal ? But for hostile influences this enlargement would have been completed in 1845, as was first proposed. How grand would our position now be, had evil counsels not prevailed ! Thanks to the wisdom of the people, the glorious work will soon be accomplished, vindicating Ug friends, and covering with shame the stupid opposition of its enemies. My object in making these remarks is to place on record in your valuable paper the facts. Let the intelligent reader judge. x. Y. z. Lockport, N. Y., June, 1858. [Our old and constant reader in his zeal for the interests of the Erie Canal, forgets our independent position—that we care not for the opinions of cities, cliqnes, or classes, in forming and expressing our own opinions. We view every question in the light of its own merits ; and we could not produce stronger testimony in favor of the correctness imd justice of the sentiments we have already expressed in reference to this question, than the foregoing letter of our correspondent. Our words will be few and final in reply. The New York and Erie Canal—which is the property of the State—was completed and in successful operation long before the advent of railroads. When the first line of the latter was laid through the State it was treated as an interloper by the political monopoly of the canal, and was forbid to carry freight, because this would interfere with the canal revenue. By and bye, however, the wants of the community demanded the repeal of this unjust policy, and railroads were then allowed to carry freight, but only by paying toll for the privilege. Every person not personally interested in the Erie Canal saw and felt that this was rank injustice, and this feeling at last grew strong enough to get the act repealed ; and so New York railroads have been free for a few years from this canal black-mail. But the spirit of aggression against our railroads is not dead yet. Last winter it was proposed to our Legislature to levy contributions on the railroads for enlarging the canal, upon assumptions like those set forth in the above letter. The attitude of the canal towards our railroads in this case, was like that of a sturdy beggar professing ability to do a better and more economical business, if the railroads were only compelled to furnish the means to enable him to go on and improve his condition ; and those who oppose this injustice must be Bet down as enemies of the " poor boatmen." We have not counseled the abandonment of the canal; but if it canno* "be enlarged without imposing unjust taxes on railroads, it ought to he abandoned. From the step-dame disposition manifested towards railroads by ti State, we think that had it owned the stage routes as it owned the Erie Canal, when railroads were first introduced, the latter (railroads) would have been taxed so much per head for each passenger, for the benefit of the "poor stage-drivers," upon the same feelings, principles, and sympathies exhibited for the " poor boatmen."—EDS.