The testimony shows that Gutenberg had a knowledge of three distinct arts. The one earliest practised, from which Dritzehen derived a good profit, was the polishing of stones or gems. The second, was that of making mirrors. Gutenberg was not the inventor of this art, but he was one of the [p391] first to practise it.[235] The early German mirrors were small, but they had broad frames, and were richly gilt and adorned with carved or moulded work in high relief. Ottley thinks that the press was used for pressing mouldings for the frames of mirrors, and that the lead was used for the metallic face. The third art is imperfectly described. If Dünne’s testimony had been lost, it would not appear that this art was printing, for there is no mention of books, paper, ink, types, or wood-cuts. The lead, the press, and the goldsmith’s work on things relating to printing, could be regarded as materials required in the art of mirror-making. But “the thing,” and “the nice things,” which provoked exclamations of surprise at their great cost, could not have been looking-glasses. Dünne said, very plainly, that this art was printing; but Dünne’s testimony could be set aside, and Gutenberg’s connection with typography at the period of this trial could be inferred from other evidence. The thoroughness of the workmanship in the books printed by Gutenberg after 1450 is a thoroughness which could have been acquired only by practice. Before he began this practice he must have devoted much time to experiment and to the making of the tools he needed. No inventor, no printer can believe that the skill [p392] he subsequently showed as a printer could have been attained by the labor of a few months or years. If it is also considered that Gutenberg was poor, and that he collected the money he needed with great delay and difficulty, the doubt may assume the form of denial. It is a marvel that he was so well prepared at the end of the ten years which Zell says were given up to investigation.