The only mechanical feature which leads to positive conclusions as to age is the manner in which they were printed. The books printed in black ink and on both sides of the paper were certainly printed after the invention of typography, and by typographic apparatus. The books in brown ink and on one side of the paper are of an earlier period. There is a peculiar rudeness about the books in brown ink which is not to be found in typographic work, a rudeness which we know began with the makers of cards or printers of images. If we consider, as we must, that the block-books are only collections of image prints, which were put in the form of books as soon as paper became cheap and popular, we may conclude with confidence that they could have been made, and probably were made, in the first quarter of the fifteenth century. The great popularity of the block-books even after 1450, when types had been invented, proves that the business of making them was then firmly established, and that it was not checked by the superior advantages offered by types. It is obvious that the block-printers of 1450 had long practice in the older method, that they were firmly attached to it, and would not abandon it in favor of the new invention. Their preference for the older method of xylography is very plainly shown by the numerous editions of the _Donatus_. [p254] XIII The Donatus, or Boy’s Latin Grammar. A Very Old Book . . . A Favorite with the Early Xylographers . . . Frequently Printed . . . Scarcity of Fragments . . . Printed by Typographic Process . . . Printed before and after Invention of Typography . . . Testimony of the Cologne Chronicle . . . Of Accursius . . . Of Scaliger . . . Of Sweinheim and Pannartz . . . Fac-simile of a German Donatus . . . Of a Dutch Donatus . . . The Arrangement of Words in the Donatus . . . Obscurity of the Letters . . . Fac-simile of a Dutch Horarium . . . Xylographic Editions are Imitations of Typographic Editions . . . Irregularities of Engraved Letters . . . The Donatus a Relic of the Past . . . Shows the Retrogressive Tendencies of the Teachers of the Period . . . The Pettiness of all Block-Books . . . An Evidence of the Limitations of Xylography. * * * * * Although the art of printing, as has been said, was discovered at Mentz, in the manner as it is now generally used, yet the first prefiguration was found in Holland, in the Donatuses which were printed there before that time. And from these Donatuses the beginning of the art was taken. _Cologne Chronicle of 1499._ * * * * *