Already, before the Dream of Poliphilo had been published in Venice, wood-engraving in the North had passed into the hands of the great German master who was to transform it; in the studio of Albert Dürer (1471-1528) it had entered upon its great period. The earlier German engravers, whose woodcuts in simple outline, shadowed by courses of short parallel lines, showed a naïve spirit almost too simple for modern taste, a force ignorant of the channels of expression and feeling inexpert in utterance, did not know the full resources of their art. It was not until the very close of the fifteenth century, when they discarded the aid of the colorists, and sought all their effects from simple contrast of black and white, that they conceived of wood-engraving as an independent art; even then their sense of beauty was so insignificant, and their power of thought was so feeble, that their works have only an historical value. Dürer was the first to discover the full capacities of wood-engraving as a mode of artistic expression; it had begun to imitate the methods of copperplate-engraving before his day, but he saw immediately that it could not equal the rival art in that delicacy of line and harmony of tone on which copperplate-engraving depends for its excellence; the materials and processes of wood-engraving required different methods, and Dürer prescribed them. He increased the size of the cuts, gave breadth and boldness to the lines, and obtained new and pleasing effects from strong contrasts of black and white. He thus showed the true method of wood-engraving; but the art owes to him much more than this: he brought to the practice of it the hand and brain of a great master, lifted it, a mechanic’s trade, into the service of high imagination and vigorous intellect, and placed it among the fine arts--a deed of far more importance than any improvements in processes or methods, even though they have such brilliant consequences as followed Bewick’s later innovations. He taught the art a language, put meaning into its words, and made it capable of conveying the ideas which art can express, and of spreading them and the appreciation of them among the people.