same operation is performed simultaneously by the ten cylinders--are sucked in at one end and disgorged at the other printed on one side, thus giving about 20,000 impressions in an hour. Such is the latest marvel of the "noble craft and mystery" of printing; but it is not to be supposed that the limits of production have even now been reached. The greater the supply the greater has grown the demand; the more people read, the more they want to read; and past experience assures us that ingenuity and enterprise will not fail to expand and multiply the powers of the press, so that the increasing appetite for literature may be fully met. * * * * * We have briefly alluded to stereotyping; but some fuller notice seems requisite of a process so valuable and important, without which, indeed, the rapid multiplication of copies of a newspaper, even by a Hoe's six-cylinder machine, would be impossible. If stereotyping had not been invented, the printer would require to "set up" as many "forms" of type as there are cylinders in the machine he uses; an expensive and time-consuming operation which is now dispensed with, because he can resort to "casts." There is yet another advantage gained by the process; "casts" of the different sheets of a book can be preserved for any length of time; and when additional copies or new editions are needed, these "casts" can at once be sent to the machine, and the publisher is saved the great expense of "re-setting." The reader is well aware that while many books disappear with the day which called them forth, so there are others for which the demand is constant. This was found to be the case soon after the invention of printing, and the plan then adopted was the expensive and cumbrous one of setting up the whole of the book in request, and to keep the type standing for future editions. The disadvantages of this plan were obvious--a large outlay for type, the amount of space occupied by a constantly increasing number of "forms," and the liability to injury from the falling out of letters, from blows, and other accidents. As early as the eighteenth century attempts seem to have been made to remedy these inconveniences by cementing the types together at the bottom with lead or solder to effect their greater preservation. Canius, a French historian of printing, states that in June 1801 he received a letter from certain booksellers of Leyden, with a copy of their stereotype Bible, the plates for which were formed by soldering together the bottom of common types with some melted substance to the thickness of about three quires of writing-paper; and, it is added, "These plates were made about the beginning of the last century by an artist named Van du Mey."