As time passed, the firm occasionally sold a copy of the “History,” but receipts were smaller than had been anticipated. Few of the common people could read,--its circulation was therefore mostly confined to the priests and nobility. The former rarely needed to purchase it, as each one could, if he desired, secure one of the kind by copying; and trouble, expense, and time were involved in gaining access to the higher classes. Gutenberg consoled himself by reasoning that his books would be called for gradually, and that he must as soon as possible issue another work suitable for a more accessible class. These were the youth in the Cathedral, studying for the priesthood, who were under the necessity of copying their “Donatuses,” or manuals of grammar. Why should he not prepare an edition for their use? He would be sure of some customers, and there would be no risk in trying his hand at a “Donatus.” The firm at once went to work upon the manual, which was one of the first school-books adapted to beginners. The children and youth of four hundred years ago had few aids in study, and few were educated. The voice of the living teacher, usually a priest, served to make passable the otherwise inaccessible paths of learning. As the busy company wrought on the “Donatus,” the curiosity of certain neighbors was excited respecting the nature of their evening employment, and it was deemed advisable more fully to remove the hidden art to Dritzhn’s shop, from which printing-office the new manuals of grammar in due time were issued. They sold more readily than the “History,” and the edition of fifty copies was soon exhausted. Many of the scholars in the Cathedral school bought them; and for a time Gutenberg and his firm were busy in issuing and Peter Schoeffer in circulating the work. The lapidary and mirror arts were still pursued by turns, although very naturally the firm felt more interest in the fascinating occupation of imprinting. After a few weeks the demand for the “Donatus” almost ceased, the pupils in Strasbourg and vicinity having been supplied, and the means of communication with other places being infrequent. There were no newspapers, and none of the methods of advertising now in vogue with publishers. Still the company was not discouraged; the sale of one book was a greater event then than is now the sale of many thousands. The call for the “Donatus” declining, the inventor turned his attention to a work of quite a different description, which was a great favorite with the more devout monks. This was the “Ars Memorandi,” or “Art of Remembering.” We have no means of ascertaining the size of this book; but it could not have been large, as almost in immediate connection with it were engraved the blocks of a religious and devotional work called “Ars Moriendi,” or the “Art of knowing how to Die.” The numerous engravings illustrating these books, Gutenberg seems to have omitted.