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within him, driving him into an incessant and restless activity of body and mind. All the amusements which require time; the luxurious indulgences which consume it; the absurdity of quiet; the unnatural condition of rest; all these he scorns, as unworthy of men whose destiny it is to create, and to build up, and to found, works, and cities, and states. Here is a whole

nation, with few rich men, and no idle men; every head and every hand busy, with a thousand projects, and only one holyday,-the Fourth of July,-working from morning till night, with the most intense industry. Yet it is not merely a sordid spirit which impels them; for what they earn thus hardly, they spend with a recklessness quite as characteristic. They work, not to accumulate, but because they must work, or die of apathy. Such a temperament is inseparable from many follies, and leads to many vices; but, after all, it is the true instinct to achieve great things, and whenever it becomes concentrated on some favorite object, wo to the rival whose path it crosses !

My hope, therefore, is, that when the country shall see what marvellous results will repay its industry, in their new career, it will enter upon it with its characteristic energy. If coal and iron have made Great Britain what she is; if they have given to her the power of four hundred millions of men, and impelled the manufactories which made us, like the rest of the world, her debtors; why should not we, with at least equal advantages, make them the instruments of our own independence?

To begin that great work, no time would be more proper than the present. Nations seem subject to the same laws as individuals, and they must go through the same diseases which afflict infancy; the same passions which mislead youth; the same infirmities which distress old age. It is, therefore, a subject rather of regret than surprise, that the last few years have been years of great national extravagance. We have bought far too much from foreign nations, and have indulged,

with a childish excess, in all the luxurious follies of the old world. Look only where this has led us. During the last ten years, we have imported about one hundred and eighteen millions of dollars of silks, and more than forty-one millions of dollars of wines and spirits, making an aggregate of more than one hundred and fifty-nine millions, for articles of the merest luxury. If we had been able to barter for these the grain and the iron which are within our reach, we might have made our industry some apology for our extravagance. But, during the same time, the productions of our farms were rigorously excluded from Great Britain, and we imported more than eighty-four millions of dollars of iron. Here, then, are

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paid, in fact, for things which we should have supplied, ourselves, or have dispensed with altogether. And having done all this, we wonder that we are so much in debt! Fortunately, too, if young nations have the errors, they have the elastic spirit and resources, of youth; and if we only cease the extravagant importation of luxuries, and cultivate our own resources, we shall soon recover from these temporary embarrassments.

To no part of the Union will such a change be more beneficial than to our own Pennsylvania. With the zeal characteristic of our American temperament, she has gone too suddenly into great public improvements, beyond the immediate wants of the State. The necessity, too, of winning over to any general system the aid of particular portions of the State, has induced her to commence too many works at one time; and, unfortunately, she has too often had, as counsellors, the two most expensive advisers in all great enterprises, ignorance and parsimony; the one directing blindly, the

other executing badly. I think it may be said, without reflecting harshly on errors, of which we must now all bear our share, that all the works executed for the developement of our Pennsylvania resources ought to have been made for two thirds of what they have actually cost; and that our debt, instead of thirty-two millions, ought not, at this day, to have exceeded twentytwo millions. But there it is, and we have nothing to do but to pay it; pay it, cheerfully and honestly; by ordinary revenue, if we can, by taxes, if we must. ter all, it is not worth while to despond over it. We owe thirty-two millions of dollars. Why, Great Britain and Ireland are not three times as large as Pennsylvania, and they owe four thousand millions of dollars.

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They pay it with coal and iron. Why may not we? If Pennsylvania, now that she will soon cease to require laborers on her public works, were to apply herself to the resources of coal and iron, which she possesses above all her sister States, she will have her rail-roads and canals covered with these heavy burdens, increasing tenfold the income from her public works, and a fresh tide of prosperity will set into the State, which will enable her citizens to carry her triumphantly through all her troubles. That she must and shall be so upheld, we all feel, since no reproach or degradation can come upon our Commonwealth, without involving all of us in a common shame.

VIII. PAGE 216.

ENGRAVING BY GALVANIC ELECTRICITY.

IN common copper-plate engraving, the lines which are to be copied by the ink on paper are cut into the surface of the metal. This circumstance renders necessary a peculiar mode of printing off the sheets, much slower and more expensive than printing with raised

types, and so unlike it, that the two kinds can never be combined in the same impression. There are many cases in which such a combination is highly desirable, especially in the figures and drawings to illustrate such a work as this. To supply the place of them, much coarser engravings on wood, or metallic castings from such engravings, are used as substitutes. Recently, a method has been discovered of producing raised lines on the copper-plate, by a very ingenious application of galvanic electricity.

The first publication on this subject appears to have been in a letter from Professor Jacobi, of St. Petersburgh, to Mr. Faraday, of London, dated in June, 1839, and published in the London Philosophical Magazine, for September of that year. In the course of the same month, (September,) a pamphlet was published by Mr. Thomas Spencer, of Liverpool, in which he states that he had made the discovery as early as September, 1837, and had been engaged in a series of experiments to bring it to a useful state of improvement. Whether or not we concede to Mr. Spencer the right which he claims, and apparently with justice, of priority of discovery, it is evident that he had, at the time of publication, advanced much further in producing useful practical results than Professor Jacobi. Another paper by Mr. Spencer, giving some results of his further experience, is published in the London Athenæum, for April, 1840. We have not seen Mr. Spencer's original pamphlet ; but an extended extract, containing apparently nearly the whole of it, is contained in the London Mechanics' Magazine, for October, 1839. From this, and from Mr. Spencer's second paper, we have prepared the following abstract.

To render the operation intelligible to those who are not familiar with the chemical effects of galvanism, it is necessary to premise a short explanation. All the metallic salts are made up of an oxide of the metal as its base, united with an acid. If the acid is withdrawn, by a stronger affinity, the metallic oxide is deposited;

or, if both the acid and the oxygen are withdrawn, the metal is deposited in a pure state. The metallic salts, as well as the other salts, are all capable of being thus decomposed by galvanic electricity; and the metal is deposited upon the surface of the wire, or plate, which forms the medium of communication of the galvanic circuit. Thus, if a solution of sulphate of copper is brought under galvanic influence, all that part of the wire which is immersed in the solution will be coated over with a film of pure copper; or, if a metallic plate be soldered to the wire, and immersed in the solution, the whole plate will be thus coated. In this case, it matters not whether the conducting metal be the same with that of the base of the salt in solution, or not.

A very simple apparatus is sufficient to excite the galvanic action for the purpose of engraving. That used by Mr. Spencer is a little more complicated. It is as follows. Take an oblong vessel, or trough, of convenient size, of earthenware or wood. Into this fit a smaller vessel, of similar form, but so much more shal

low, as to allow a sufficient space for the copper plate and the solution in which it is placed, between the two vessels. The bottom of the inner vessel must be composed of some porous substance, suitable for the transmission of the galvanic action. Mr. Spencer at first used plaster of Paris; but, in his late communication, he recommends brown paper, as rendering the deposition of copper more rapid and more firm than any thing else that he had tried; "not the brown paper usually sold by the stationers, but a thicker sort, manufactured by the papermakers to enclose their parcels." This paper he fastens to the bottom of the vessel by melted pitch, or the common resinous cement used by philosophical-instrument makers. It will be perceived, that we have, by this rangement, a galvanic apparatus with two cells, diffeg from the common apparatus only in providing for a horizontal position of the plates in the cells, and at the same time preserving their parallelism; the porous bottom of the interior vessel operating as a partition be

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