increasing thirst for knowledge which at this period was every where manifesting itself, arrested his attention, and convinced him of the desirability, as well as the profitableness, of devising some method for its more ready and abundant supply. The problem of the mechanical multiplication of manuscripts had already been partially solved in the block-books which were manufactured in Holland. In the study of these, Gutenberg perceived the immense advantages which would follow from having every letter made separate, with sufficient quantities of each to allow of their being combined into words, sentences, and pages, instead of continuously engraving whole series of lines in solid blocks as in the specimens before him. That idea once clearly seen, time and patience, with the ability to engrave, were all that were required for its realization, so far at least as concerned the mere making of the types or letters. The first experiments would naturally be, as indeed we are informed they were, on wood. And one can well imagine the flush of triumph that mantled on his brow, when, after having engraved a few continuous sentences, or sets of alphabets, with spaces between each line and letter; and after having sawn each line asunder, and separated each letter from the one adjoining, and trimmed and squared the whole to his mind, Gutenberg recomposed the letters into words, and other words, which differed from the original, and saw his cherished thought worked out complete before him. But, while thus on the very threshold of success, obstacles and difficulties began to present themselves, which taxed his ingenuity and tried his perseverance to an extent which it was scarcely possible for him to have foreseen. In the first place, whatever plan he may have adopted to produce impressions in his earliest experiments, he could not fail to find out in a very short time that the Chinese method, adopted by the block-book printers, would not answer for his separable types; and moreover, that the fine strokes and edges of his wooden letters were liable to damage and destruction from other causes besides those arising from the amount of pressure it was necessary to subject them to in order to ensure a clear readable impression. It was necessary therefore to resort to metal. This was, in itself, a serious matter to begin with, for engraving on metal is a much more difficult, tedious, and expensive process, than engraving on wood. With separable types, and direct perpendicular pressure to produce impressions, a different kind of ink or pigment to that hitherto used by scribes, or stencillers, or block-book printers, also became necessary, as well as a different method of applying it to the face of the types; and many an experiment must have been made, and much time and money lost, before these difficulties were overcome, and success attained in these as in the preceding step.[35]