To the above account it may be added, that the blocks, each containing two pages, are frequently engraved on both sides; that the sheets printed are small, and impressed on one side only; and that each sheet when dry is folded back, so as to present the appearance of a leaf impressed on both sides. The history of printing in China, and the productions of the Chinese press, are subjects which Oriental bibliographers have more or less touched upon. Interesting as they are, there will probably be no occasion to allude to them in these pages more than once again. But the history of books in Europe, the productions of the early printers in the various countries to which they carried their art, is one to which our subject is most closely allied; and European bibliography is a study to which many men of great ability have devoted themselves during the last three centuries, in Germany, Holland, England, Spain, France, Italy, Belgium, and other countries. To their labours all later writers on the subject are under manifold obligations.[8] But in attributing various undated books to one or other of the earliest established presses, guess-work, and the bias of national prejudice, have largely prevailed amongst even the most painstaking of European bibliographers. This unscientific method, long felt to be a reproach to learning and literature, has of late years been attempted to be remedied by a more close and critical examination of the Incunabula, or books printed in the Fifteenth century. “The method of arranging these early books under the countries, towns, and presses at which they were produced,” says Mr. Henry Bradshaw, the Librarian of the University of Cambridge, “is the only one which can really advance our knowledge of the subject. This is comparatively easy with dated books, though there is no safeguard against the misleading nature of an erroneous date. But the study is of little use unless the bibliographer will be content to make such an accurate and methodical study of the types used and habits of printing observable at different presses, as to enable him to observe and be guided by these characteristics in settling the date of a book which bears no date on the surface. We do not want the _opinion_ or _dictum_ of any bibliographer, however experienced; we desire that the types and habits of each printer should be made a special subject of study, and those points brought forward which shew changes or advance from year to year, or where practicable, from month to month. When this is done, we have to say of any dateless or falsely dated book, that it contains such and such characteristics, and we therefore place it at such a point of time, the time we name being merely another expression for the characteristics we notice in the book. In fact each press must be looked upon as a _genus_, and each book as a _species_, and our business is to trace the more or less close connection of the different