上学期《英汉笔译》试卷第一道题的英文原文，当中有个词组：cradle books，该词组直译就是“摇篮书”或者“摇篮本”。这到底是什么书？
这个英文词组有一个更为常见的对应的单词：incunabulum，读音[ˌɪnkju(ː)ˈnæbjʊləm]，复数是incunabula。这个单词源于拉丁语，意为in the cradle （摇篮期，初期，早期），譬如说：the incunabula of jazz（爵士乐的早期），引申指“1501年前采用活字印刷的书”，通俗的译法是“故版本”。
耶鲁大学贝内克珍本与手稿图书馆（Beinecke Rare Book and Manuscript Library）是一座恒温图书馆，馆藏的是全部是古籍善本，镇馆之宝包括一部《圣经》摇篮本，即欧洲最早的活字印刷本《古腾堡圣经》（Gutenberg Bible），1450年代印刷于德国。据说现存完整的《古腾堡圣经》，全世界共有21部，当中就包括耶鲁收藏的这一部。
网上有对incunabula这个单词的介绍：
Incunabula, books printed during the earliest period of typography—i.e., from the invention of the art of typographic printing in Europe in the 1450s to the end of the 15th century (i.e., January 1501). Such works were completed at a time when books—some of which were still being hand-copied—were sought by an increasingly large number of readers.
The year 1500 as the limit of the period of incunabula was first adopted in 1643 by Johann Saubert in his history of the Nürnberg library (Historia Bibliothecae Noribergensis), which includes the first known catalog of a collection of such books. The limit is convenient but arbitrary, since no special development in the printing art can be connected with it.
The celebration in 1640 of the second centenary (as it was considered) of the invention of printing in Europe may be taken as the date from which incunabula began to be studied and collected for their own sake—that is, apart from their literary interest. Even so, copies of some books printed by William Caxton in the 15th century could be bought for a few shillings up to the end of the 17th century.
The concept of early printing as “incunabula” seems to have first been used by Bernard von Mallinckrodt in De Ortu ac Progressu Artis Typographicae, Dissertatio Historica (1639); the concept was also applied generally by Jesuit scholar Philippe Labbé in Nova Bibliotheca (1653), but it was Cornelius à Beughem who applied the term more specifically to 15th-century books. His use of the word appeared in a sale catalog, Incunabula Typographiæ, issued in 1688. In Classical times incunabulum signified “cradle” or “swaddling clothes” and so “beginning.” The Latin word was adopted also in French (incunables) and Italian (incunaboli) as well as in other languages, and the German Wiegendrucke expresses the same idea.
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