The details of the life and early work of Gutenberg are at best but fragmentary, and have been a subject of much discussion. It is not necessary, for the purpose of this treatise, to give detailed consideration to the long series of controversies as to the respective claims of Gutenberg of Mayence, of Koster of Haarlem, or of other competitors, as to the measure of credit to be assigned to each in the original discovery or of the practical development of the the printing-press. It seems in any case evident that whatever minds elsewhere were at that time puzzling over the same problem, it was the good fortune of Gutenberg to make the first practical application of the printing-press to the production of impressions from movable type, while it was certainly from Mayence that the art spread throughout the cities, first of Germany, and later of Italy and France. It is to be borne in mind (and I speak here for the non-technical reader) that, as indicated in the above reference, the distinction and important part of the invention of Gutenberg was, not the production of a press for the multiplication of impressions, but the use of movable type and the preparation of the form from which the impressions were struck off. The art of printing from blocks, since classified as xylographic printing, had been practised in certain quarters of Europe for fifty years or more before the time of Gutenberg, and if Europe had had communication with China, xylography might have been introduced four or five centuries earlier.