The Detroit Free Press gives the following well prepared summary of all the wool purchased, carded, or manufactured in Michigan for 1862 and 1860: ON THE LINE OF THE MICHIGAN CENTRAL RAILROAD. ON THE LINE OF THE DETROIT AND MILWAUKEE RAILROAD. The coal trade to July 11th sums up as follows, compared with last year: From the above we see that there has been an increase of 1,210,479 tons of coal this year as compared with the same period in 1862. This immense surplus cannot, under any circumstances, be absorbed by the government in furnishing supplies for the navy, or in meeting increased exigencies of manufacture. It is doubtful whether a much larger amount is required for the former purpose than was taken last year, when our steam naval armament was upon nearly as extensive a footing as at present; and we all know the consumption for manufacturing purposes, owing to the suspension of our cotton mills, has largely fallen off this season. In fact, this increased production is not so much owing to an increased demand as to the greatly enlarged facilities for mining, of a mechanical description, which have lately been carried into effect; and hence the pretended danger of a scarcity of this commodity is merely one of the customary expedients got up by trade combinations to keep up prices, when in the natural course of events they would be certain to fall. The truth undoubtedly is, there was much danger of an over-production in this branch of industry, and the supply was considerably ahead of the demand when General LEE marched his army across the Northern border -without, however, in any manner threatening the mining interest, as he had plenty of "other fish to fry." Hence with a stock on hand which would otherwise, at this season, have speedily brought down the market—which retailers throughout the country were daily expecting, and for which they were persistently holding off instead of laying in their supplies-this raid furnished the mining combination a most opportune pretext for suspending operations for awhile, and playing a bold game of bluff by pretending to shut down upon the trade. By this artifice they expected to accomplish the triple purpose of preventing too great an accumulation of stock, of keeping prices up when they ought to go down, and of inducing the trade to bite sharply and buy freely when the embargo was removed. How far they have attained these ends the public well know. The stocks of retailers, who have been disappointed in securing their customary supplies at reasonable rates, are generally very low, and consumers are obliged to pay the highest rates of last winter. The official bulletin of the combination which announces the re-opening of the market in Philadelphia, also promulgates their gracious permission for dealers to purchase cargoes at former prices, with the addition of the advanced freight charge from the Schuylkill mines over the Reading Railroad. But why this advance in freight? To be sure it has been made sometimes in former years on the plea of protecting dealers who bought their supplies early in the season, at higher prices than are current in midsummer. But, this year, those who laid in their stocks early are the fortunate ones, and need no protection. We think, however, there must be a better time coming. With such an increase in supply there certainly can be no danger of scarcity, and prices must take a tumble as soon as that fact becomes apparent. JOURNAL OF MINING, MANUFACTURES, AND ART. MANUFACTURERS OPPOSITION TO THE INCOME TAX. WHY is it that all the world goes to Chicago to hold conventions? The manufacturers feeling themselves agrieved by the income tax have lately been there, held a convention, passed resolutions, and gone home. Western members of the craft were not very largely represented, as they are probably but slightly affected by the provisions of the internal revenue law. As to the resolutions passed they are certainly plain spoken, and to the point. The Secretary of the Treasury is by them politely requested to suspend the operation of the objectionable provision till the assembling of the next Congress. Such a request as this, must be based, we suppose, upon the assumption that the imposition of the tax is purely a mistake, made through the inadvertence of the last Congress, which its successor will hasten to rectify that the framers of the law could not, in their superabundant wisdom and well-known regard for this branch of our national industry, have intended to tax the profits of manufacturers, after having heavily taxed the manufactures themselves; but, through carelessness, left the statute open to such a construction. The following is the decided answer that the Department returns to the resolutions: Treasury Department, Office of Internal Revenue, SIR: Yours of the 11th instant, addressed to the Honorable Secretary of the Treasury, with accompanying note from Hon. Mr. CHANDLER, your own letter to the Manufacturers' Convention, and the resolutions of said Convention, have been received and forwarded to this office. In reply, allow me to express my profound gratification at the lucid manner in which you demonstrate the justice of the law. Rest assured that the law is not considered by this office in the light either of a mistake or an accident, and that its provisions will be neither explained away, nor its operations suspended. E. B. WARD, Esq., Detroit. Very respectfully, EDWARD MCPHERSON. We think another convention will now be in order, and would suggest that all taxpayers be let in, for we apprehend that manufacturers have less reason to complain than falls to the lot of many classes of business men under this tax-reduplicating dispensation. Indeed, the farther removed from the point of consumption any class may be, the lighter its burdens, as a general thing, under the practical workings of the system; so that those who stand at the source of supply, whence the stream of taxation swells and gathers strength in its downward course, are really least affected by it. Like importers under the tariff system, whose individual contributions to the pub lic revenue seem to be enormous only at first sight, the manufacturers are really the most disinterested persons in the community so far as the tax upon their products is concerned. There is not even a division of this tax between the producer and consumer; but the whole of it, both specific and ad valorem, is invariably added to the prime cost of the manufactured article, and ultimately falls either wholly upon the consumer, or is partially shared by the retailer-who of all others should be exempt from any portion of it, since he stands in the gap between the government and his customers and guaranties to them that the former has no lien upon his goods, and that all excise duties accruing upon them have been honestly paid. The income tax complained of is really the only government charge in any shape which touches the pockets of manufacturers; and the public treasury will undoubtedly derive a considerable revenue from this source, as their profits have been enormous during the year past. With a tariff which shuts out foreign competition, and gives them a virtual monopoly of the home market-such as this great interest has always sought for and at last obtained-it seems to us, so long as the government must needs rely in a great measure upon the productive industry of the country for support, that a class so peculiarly favored, in the abundance of their prosperity, will not generally object to rendering this simple quid pro quo in the present emergency of our national affairs. If they seek to evade it, it is to be feared their example may have a bad influence upon other classes, less interested, perhaps, in sustaining the government. LEATHER CLOTH. On the subject of leather cloth the London Times has the following:"The recent continuous increase in the price of leather has naturally directed the attention of practical chemists to the best methods of perfecting the imitations which, under the name of leather cloth, are now so largely used as substitutes for leather itself. The improvement in this branch of manufacture has been so steadily progressive that the original standard taken for Imitation-the American leather cloth--has been long since surpassed, and it is, perhaps, not too much to say that the art of making artificial leather has now attained a perfection which promises to make the imitation a better, and, though cheaper, a more valuable article than that which it imitates. Among the many new processes and inventions shown in the late Exhibition, there was no lack of English representative of this rising branch of manufacture, striving to displace the American fabric. Nearly all these, however, were too much like the Transatlantic article to be successful. With its merits they reproduced its grave defects--the liability of the varnish to crack, the colors to fade, and the material itself to wear out fast as compared with real leather. One series of specimens, however, in this class attracted a good deal of attention, though they failed to attract a medal. These specimens were shown by Mr. SZERELMY, a gentleman well known for his most curious chemical discoveries in hardening wood, stone, and paper; and, to the present time, the most successful of all the many competitors for preserving the House of Parliament from further decay by indurating the surface of the stone with a fluid silica, which, it is asserted, renders the stone beneath perfectly indestructible. The leather cloth of |