The press Gutenberg was using was a very simple affair. Two upright posts were fastened together by crosspieces at top and bottom. In this frame a big iron screw was worked by means of a handle. A board was fastened beneath the screw, and the type, when inked and set in a wooden frame, were placed on this board. The printing paper was laid over the type, and the screw forced the platen, which was the board fixed to it, down upon the paper. Then the screw was raised by the handle, the platen was lifted with it, and the printed paper was ready to be taken out. The screw was worked up and down in a box, called a hose, and the board on which the type were set for the printing was actually a sort of sliding table. The frame or chase of type was fixed on this table, and when inked and with the paper laid in place, was slid under the platen, which was a smooth planed board. The screw was turned down, the platen was pressed against the sheet of paper, and the printing was done. Each of the workers at the Zum Jungen suggested valuable changes and additions. Schœffer proved wonderfully adept at cutting type, and later at illuminating the initial letters that were needed. The copies we have of the books published by this first Mainz press bear striking witness to the rare skill and taste Peter Schœffer showed in designing and coloring the large capital letters that were considered essential at that day. The firm had by now prepared several hundred pounds’ weight of metal type for the Bible, had discovered that a mixture of linseed oil and lampblack made the best ink, and had invented ink-dabbers made of skin stuffed with wool. Then it occurred to Schœffer that there must be some easier way of making type than by cutting it out by hand. After some study he found it, and the firm began taking casts of type in plaster moulds. But the success of this method seemed very doubtful at first, for it was hard to get a good impression of such small things as type in the soft plaster. Again Schœffer showed his skill. He planned the cutting of punches which would stamp the outline of the type upon the matrix. He cut matrices for the whole alphabet, and then showed the letters cast from them to Gutenberg and Faust. “Are these letters cast in moulds?” exclaimed the astonished Faust. “Yes,” answered Schœffer. “This is the greatest of all thy inventions then,” said Faust. “Thou art beyond all question a great genius!” With type cast in this new way the firm printed the first page of their Bible in the spring of 1450. The press worked to perfection, and when they removed the vellum sheet the printed letters were clear, beautifully formed, and ranged in perfect lines. So began the printing of what was to become famous as the Mazarine Bible. But it was not until five years later, in 1455, that the book was finished.