Again, Lorentz Beildeck testified that after Andres Dritzehn's death, Gutenberg sent him to Claus, Andres' brother, to tell him "that he should not show to anyone the press which he had under his care," but that "he should take great care and go to the press and open this by means of two little buttons whereby the pieces would fall asunder. He should, thereupon, put those pieces in or on the press, after which nobody could see or comprehend anything." Besides this, Hans Niger von Bischoviszheim said that Andres Dritzehn applied to him for a loan, and when witness asked him his occupation, answered that he was a maker of looking-glasses. Later on, a pilgrimage "to Aix-la-Chapelle about the looking-glasses" is mentioned. By these records, from Mr Hessels' translation of which the above quotations are taken, two things at least are made clear. First, that Gutenberg was in possession of the knowledge of an art unknown to his companions, which he was desirous of keeping to himself, and which those not in the secret wished to learn; and secondly, that a press containing some important and mysterious "pieces," which was not to be exhibited to outsiders until the pieces had been separated, played a prominent part in this secret work. The "looking-glasses," apparently, were imaginary, and intended for the misleading of too curious enquirers. But it has been ingeniously suggested that the word _spiegel_, or looking-glass, was a cryptic reference to the _Spiegel onser Behoudenisse_, or _Mirror of Salvation_, and that Gutenberg and his assistants were engaged in preparing the printed _Speculum_ for sale at the forthcoming fair held on the occasion of the pilgrimages to Aix-la-Chapelle in 1439. This part of his plan, however, was frustrated by the postponement of the fair for a year. It is hardly to be doubted that the researches privately conducted in the deserted convent of St Arbogastus, where Gutenberg dwelt, concerned the great invention usually linked with his name. Were this probability an absolute certainty, then Strasburg might successfully dispute with Mentz the title of birthplace of the art of printing. But to what stage Gutenberg carried his labours in the old convent, or how far he proceeded towards the goal of his ambition, is not known, though it has been conjectured that possibly he and those in his confidence got as far as the making of matrices for types, and that perhaps even the types used for the earliest extant specimens of type-printing were cast there, although not used until Gutenberg had returned to Mentz. On the other hand, there are many who think that matrices and punches are due to the ingenuity of Peter Schoeffer, to whom reference is made below.