Since the beginning of the present century, and more especially within the last thirty years, presses wholly of iron, on the nicest scientific principles, have been invented by men of mechanical genius, so as to simplify the process of printing in an extraordinary degree; and the invention of presses composed of cylinders, and wrought by steam, has triumphantly crowned the improvements in this art. The alteration effected by steam power has been as great in the printing business, as in any branch whatever; for example, with the old wooden press, it took a man two days to complete 1000 sheets, (that is, printed on both sides); whereas the London “Times,” by means of the steam press completes 24,000 in one hour! Almost every newspaper in the kingdom is printed by cylinder-presses, although some are worked by hand instead of steam; they are also used in other departments of the printing business. The introduction of steam-presses would have been of comparatively little benefit, if it had not been furthered by another invention of a very simple nature, now of great value to the printer. We here allude to the invention of the roller for applying the ink, instead of the old clumsy and inefficient balls. The roller, which is simply a composition of glue and treacle, cast upon wooden centre-pieces, was invented by a journeyman printer from Edinburgh, about thirty years ago, and was so much appreciated by the trade, as at once to spread over the whole of Europe. Were it possible to conjure up the spirits of the illustrious Guttenburg and his contemporaries within the office of the London “Times,” or some other large printing-office, where everything is conducted with rapidity, quietness, and order, John Faust might well think that the printers of the nineteenth century had actually consummated what he was only accused of in the fifteenth--completed a compact with the devil! As it would be a waste of time for us to pretend to describe the various processes and materials required in this beautiful art, as we are aware that, without actual observation, no conception can be formed,--this we know from experience, and though we might, like many others, have pretended to give a description, we are perfectly aware that we would have been unintelligible to the majority of our readers, and very deservedly laughed at for our trouble by any practical printer who might happen to read our pages; as far as we have gone, however, in giving a brief historical account of the art of printing, we have no doubt it will be found correct, as have consulted the best authorities. STEREOTYPE.