A knowledge of the different classes and bodies of Letter used by Printers is necessary to the accu rate description of Books, and discrimination of editions. The Bibliographer must also be acquaint ed with the corresponding appellations assigned to the different bodies -of letter by foreign Printers. Thus the form called pica by English Printers, is called Cicero by those of France and Germany, be cause Cicero's Epistles were printed in that type. The form called paragon. is the only one which re tains the same name among the Printers of all coun tries. Upon all these points, Stower's Printer's Grammar, and Fournier's Manuel T Traphique, may be consulted with advantage. s e latter is rich in specimens very neatly executed. It consists of two octavo volumes published in 1764, to which the author, whe was a Parisian Letter-founder, and Engraver of great ingenuity and taste, intended to have added two more, but was presented by his death, which happened in 1768. s ' The Books of the Ancients were generally in the form of cylinders, made by rolling the joined sheets upon a stick, to the ends of which, nobs or balls were affixed, often richly ornamented • there being just as much foppery among the Collectors of an cient times, as to the matter of ornamenting their Books, as among the Bibliomardacs of the present ' day. In the infancy of Printing, the sizes were ge nerally folio and quarto ; and some have supposed that no Books were printed in the smaller forms till after 1480 ; but M. Peignot instances many editions in the smallest forms, of' an earlier date ; as may be seen in the article Format of the Supplement to his Dictionnaire de Bibliologie. An accurate know ledge of the different forms of Books is necessary to the Bibliographer, as, without this, no Book can be correctly described ; and however easy of acquisi tion this knowledge may appear, it is yet certain, that errors in this respect are sometimes committed even by experienced Bibliographers; and that doubts have been entertained as to the existence of edi tions, owing to their forms having been inaccurately described. • These mistakes generally proceed from this, that there are different sizes of paper comprehended under the same name. But the water lines in the sheets afford a test; as they are uniformly 'perpendicular in all folio and octavo sizes, and bon iontal in all quarto and duodecimo sizes.
When Books have gone through more than one edition, various minute inquiries must often be made, in order to determine the respective merits of those editions. It is a principal object of the Biblio graphical Dictionaries, to be afterwards mentioned, to point out the editions of important works, which such inquiries have ascertained to be the best. There are many particulars in which one edition may differ from, or excel another. There may be differences and ground& of preference in Size, in Paper, and in Printing. The Text of one edition may be more correct than that, either of a preceding, or a subse quent one. An author sometimes corrects errors, makes alteritions, or introduces new matter when his work comes to be reprinted, thereby giving the edition so altered a decided superiority over it predecessor. One edition may differ from another by having Notes, an Index, or Table of Contents, which that other wants ; or these accompaniments may themselves furnish grounds of preference by be ing superior in their kind in particular editions. Plates make great differences in the value of edi tions, and even in the value of Copies of the same ' edition. In the beautiful engraved edition of Ho race by Pine, there is, in the copies first thrown off, a small error, which serves as a test by which Biblio graphers immediately judge whether any copy has the best impressions of those elegant vignettes which illustrate that edition. The medal of Augustus In
page 108 of the Second volume, has, in the copies first thrown off, the incorrect reading Post Est for Potest ; this was rectified in the after impressions ; but as the Plates had previously sustained some in jury, the copies which show the incorrect reading are, of course, esteemed the best. Mr Dibdin, in his Book called The Bibliomania, very absurdly points out this as an instance of preference founded on a defect ; whereas the ground of preference is the superiority of the impressions, ascertained, with out the necessity of any comparison, by the pre sence of this trifling defect. There are, sometimes, owing to particular circumstances, differences be tween Copies of the same edition of a work ; and which, therefore, stand to each other in the same relation, as if there had been another edition with some variations. Walton's Polyglott Bible is a ce lebrated instance. The printing of that great work, for which Cromwell liberally allowed paper to be imported free of duty, was begun in 1653, and completed in 1657 ; and the preface to it, in some copies, contains a respectful acknowledgment of this piece of patronage on the part of the Protector ; ,hut in other copies, this compliment is expunged, and replaced by some invectives against the Republi cans, Dr Walton having, at the Restoration, printed another preface to the copies which were undisposed of at that event, • The copies, with the original preface, are much rarer, and of course more prized, than those with the loyal one, which latter seems to have helped the author to-the Bishopric he after. wards obtained.
The productions of the Press, in the different countries of Europe, during the century in which Printing was invented, have engaged much of the at tention of Bibliographers, and have been described in various works, compiled for that purpose. The first of those productions to which the name of Books has been applied, were printed, not with moveable types, but with solid wooden blocks ; and consisted of a few leaves only, on which were impressed images of Saints, and other historical pictures, with-appropriate texts or descriptions. These leaves were printed only on one side, and the blank sides were generally, though not always, pasted together, so as to look like single leaves. The ink used was of a brownish hue, and glutinous quality, to prevent it from spread. ing. These curious specimens of the infant art are called Image Books or Block Books. They have often been largely described, every particular con cerning them being fondly cherished by Bibliogra phers. Their number is fixed by some at seven, and by others carried to ten ; but there have been numerous editions of' most of them ; for they maintained their popularity long after the inven tion of the art of Printing, properly so called. One of the most celebrated is the Biblia Pauperum, consisting of forty leaves, printed on one side, as to make twenty when pasted together ; upon which, certain historical passages of the Old and New Tes tament are represented by means of figures, with rela tive inscriptions. It was originally intended, as its name imports, for the use of those poor persons who' could not afford to purchase complete copies of the Bible. There is a copious account of all the Block Books, in Baron Heinecken's learned work, Idecl nirak dune Collection complette d'Estanipes, publish ed in 1771, in one volume octavo. Mr Dibdin's Bibli otheca Spenceriana contains facsimiles of the figures in several of them, as does also Mr Ottley's History of Engraving.