Would it not have been surprising that the pilgrims who were to visit Aix-la-Chapelle on the occasion of the grand jubilee of 1440, should be so anxious to buy ornamented mirrors? As to the art “_of polishing stones_,” which Gutenberg had taught at first to Andrew Dritzehen, who derived from it “_so much profit_,” having anything to do with printing was, no doubt, also questionable; but we have not been able to solve the enigma, and wait to clear up the difficulty till a new _incunable_ (_incunabula_, “a cradle,” the word is applied to the first editions ever printed) is discovered, the work of some Peter (πἑτρος “a stone”) or other; as, for example, the Latin sermons of Hermann de Petra on the Lord’s Prayer; for Gutenberg, when speaking of _polishing stones_, might have enigmatically designated a book he was printing; just as his partner, in answer to the judge, after having raised his hand on high and sworn to give true evidence, could call himself _a maker of mirrors_, without telling a falsehood, without committing perjury. The secret of printing was to be religiously kept by those who knew it. In short, it results from all this that Gutenberg, “an ingenious man and a man of invention,” having seen a xylographie “Donatus,” had endeavoured to imitate it, and had succeeded in doing so, the secret being confided to Andrew Dritzehen; that the other _arts_, which Gutenberg at first kept to himself, but which he subsequently communicated to his partners, consisted in the idea of substituting movable type for tabular printing; a substitution that could only be effected after numerous experiments had been made, and which were just about to be crowned with success when Andrew Dritzehen died. We may then consider it as nearly certain that printing was in some sort discovered twice successively--the first time by Laurent Coster, whose small printed books, or books in letterpress (_en moule_), attracted the attention of Gutenberg; and the second time by Gutenberg, who raised the art to a degree of perfection such as had never been attained by his predecessor.