_Believing that a verbal description of old books and prints, without pictorial illustrations, would be unsatisfactory, I have provided many fac-similes of early printing. No part of this work will more fully repay examination than its illustrations, which have been carefully selected from approved authorities, or from originals. Reproduced by the new process of photo-engraving, they are accurate copies of the originals, even when of reduced size. As they are printed with the descriptive text by the same method of typographic presswork, it is believed that they will more clearly illustrate the subject than lithographed fac-similes on straggling leaves._ _In trying to make plain whatever may be obscure about the mechanics of printing, I have thought proper to begin the explanation with a description of its different methods. An introduction of this nature is not an unwarrantable digression. It is important that the reader should have an understanding of the radical differences between typography and xylography on the one side, and lithographic and copper-plate printing on the other, as well as some knowledge of the construction and uses of the more common tools of type-founders._ _I do not propose to give any extended quotations in foreign languages. Wherever an approved translation in English has [p014] been found, it has been substituted for the original text; where translations have not been approved, they have been made anew. Writing for the general reader, I have assumed that he would prefer, as I do, in every book to be read and not studied, a version in English rather than the original text. Believing that the frequent citation of authorities, especially in instances where the facts are undisputed, or where the books are inaccessible, is an annoyance, I have refrained from the presentation of foot-notes which refer to books only. I have, in a few cases, deviated from this course where the matters stated were of a character which seemed to require the specification of authority._ _One of the greatest impediments I encountered when about to begin the compilation of this work was the difficulty of access to books of authority. I do not mention this in disparagement of the management of our public libraries, for I know that old books are liable to injury in the hands of the merely curious, and that librarians have little encouragement to collect scarce books on typography. To prove that there is small inquiry for treatises of this character, it is enough to say that I have had to cut open the leaves of valuable books after their rest for many years on the shelves of one of the largest libraries of this city. But if these books were ever so abundant, the proper restrictions placed on their use were a hindrance to one whose chief opportunity for consulting them is at night._