INCUNABULA, a Latin neuter-plural meaning "swaddling clothes," a "cradle," "birthplace," and so the beginning of any thing, now curiously specialized to denote books printed in the I sth century. Its use in this sense may have originated with the title of the first separately published list of 15th century books, Cornelius a Beughem's Incunabula typographiae (Amsterdam, 1688). The word is generally recognized all over Europe and has produced vernacular forms such as the French incunables, German Inkunabeln (Wiegendrucke), Italian incunaboli, and the anglicized form incunables is now frequently used. Despite the rapid de velopment of printing in some centres as compared with others, the attractions of a round date have caused the word to be ap plied to all books produced before the close of the year 1 soo and to these alone. The earliest important catalogues of them were (i.) Panzer's Annales typographici ab artis inventae origine ad annum MD., printed in five volumes at Nuremberg in 1793 and subsequently in 1803 carried on to 1536 in six additional volumes; (ii.) Hain's Repertorium bibliographicum in quo libri omnes ab ante typographica inventa usque ad annum MD. typis expressi ordine alphabetico vel simpliciter enumerantur vel adcuratius, re censentur (Stuttgart, 18 2 6-38) . In Panzer's Annales the first principle of division is that of the alphabetical order of the Latin names of towns in which incunabula were printed, the books be ing arranged under the towns by the years of publication. In Hain's Repertorium the books are arranged under their authors' names, and in 1891 an invaluable index of printers was added by Konrad Burger. In 1898 Robert Proctor published an Index to the Early Printed Books in the British Museum: from the invention of printing to the year MD., with notes of those it the Bodleian Library. In this work the books were arranged as far as possible chronologically under their printers, the printers chronologically under the towns in which they worked, and the towns and countries chronologically in the order in which printing was introduced into them, the total number of books registered being nearly 1 o,000. After Proctor's premature death in 1903, the trustees of the British Museum ordered a full dress catalogue of its incunabula to be prepared, and of this five volumes have been issued, comprising Germany (including Austria and German speaking Switzerland), Rome and Venice. In France Mlle. Pelle chet in 1897 began a Catalogue general des incunables des biblio theques publiques de France, which was continued by M. Louis Polain but stopped in the middle of G. In Germany after 21 years of preparation the first volume of a Gesarntkatalog der Wiegendrucke was published in 1925.
In any attempt to estimate the extent to which the incunabula still in existence represent the total output of the 15th century presses a sharp distinction must be drawn between the weightier and the more ephemeral literature. Owing to the great religious and intellectual upheaval in the 16th century much of the litera ture previously current went out of date, while the cumbrous early editions of books still read were superseded by handier ones. Before this happened the heavier works had found their way into countless libraries and here they reposed peacefully, only sharing the fate of the libraries themselves when these were pillaged, or, by a happier fortune, amalgamated with other collections in a larger library. The considerable number of copies of many books for whose preservation no special reason can be found encourages a belief that the proportion of serious works now completely lost is remarkably low, except in the case of books of devotion whose honourable destiny was to be worn to pieces by devout fingers. On the other hand, of the lighter literature in book-form, the cheap romances and catchpenny literature of all kinds, the destruction has been very great. Most of the broadsides and single sheets generally which have escaped have done so only by virtue of the i6th century custom of using waste of this kind as a substitute for wooden boards to stiffen bindings. Excluding these broadsides, etc., the total output of the 15th century presses in book form is not likely to have exceeded 40,00o editions. As to the size of the editions we know that the earliest printers at Rome favoured 225 copies, those at Venice 300. By the end of the century these numbers had increased, but the soft metal in use then for types probably wore badly enough to keep down the size of editions, and an average of Soo copies, giving a possible total of 20 million books put on the European market during the 15th century, is probably as near an estimate as can be made.
Types as Evidence.—Very many incunabula contain no in formation as to when, where or by whom they were printed, but the individuality of most of the early types as compared with modern ones has enabled typographical detectives (of whom Robert Proctor, who died in 1903, was by far the greatest) to track most of them down. To facilitate this work many volumes of facsimiles have been published, the most important being K. Burger's Monumenta Germaniae et Italiae Typographica (1892, etc.), J. W. Holtrop's Monuments typograpliiques des Pays-Bas (1868), O. Thierry-Poux's Premiers monuments de l'imprimerie en France au XVe siecle (189o), K. Haebler's Typographie ibtirique du quinzieme siecle (19o1) and Gordon Duff's Early English Printing (1896), the publications of the Type Facsimile Society (1700, etc.) and the Woolley Facsimiles, a collection of 50o photographs, privately printed by George Dunn.
In his Index to the Early Printed Books at the British Museum Proctor enumerated and described all the known types used by each printer, and his descriptions have been usefully extended and made more precise by Dr. Haebler in his Typenrepertorium der Wiegendrucke (1905, etc.) . With the aid of these descriptions and of the facsimiles already mentioned it is usually possible to assign a newly discovered book with some certainty to the press from which it was issued and to fix within narrow limits the date at which it was finished.
The total number still extant of incunabula printed in England is about 36o, of which Caxton produced nearly Ioo. Of the io,000 different incunabula which the British Museum and Bodleian Library owned between them in 1898, about 4,10o are Italian, 3,40o German, i,000 French, 70o from the Netherlands, 40o from Switzerland, 15o from Spain and Portugal, 5o from other parts of the continent of Europe and 200 English, the proportion of these last to the total known being about doubled by the special zeal for collecting them. The celebration in 164o of the second centenary (as it was considered) of the invention of printing may be taken as the date from which incunabula began to be collected for their own sake, apart from their literary interest, and the publication of Beughem's Incunabula typographiae in 1688 marks the in creased attention paid to them. But up to the end of the 17th century Caxton's could still be bought for a few shillings. The third centenary of the invention of printing in 174o again stimu lated enthusiasm, and by the end of the i8th century the really early books were eagerly competed for. Interest in books of the last io or 15 years of the century is a much more modern develop ment, but with the considerable literature which has grown up round the subject is not likely to be easily checked.
The chief collections of incunabula are those of the Bibliotheque Nationale at Paris, Royal library, Munich, and British Museum, London, the number of separate editions in each library exceeding 9,00o with numerous duplicates. The number of separate edi tions at the Bodleian Library is about 5,000. Other important col lections are at the University library, Cambridge, and the John Rylands library, Manchester, the latter being based on the fa mous Althorp library formed by Earl Spencer (see BOOK-COL LECTING). A census of 15th-century books owned in America, compiled by a committee of the Bibliographical Society of Amer ica, published in 1919, enumerated over 13,20o copies of some 6,64o different editions. The chief collections are in the Pierpont Morgan library, New York, the Annmary Brown Memorial, Provi dence, R.I., the Henry Huntington library, San Gabriel, Calif., and the library of Congress at Washington. (A. W. P.)