This artist produced well-authenticated works; one of them is signed, and leaves no doubt: the _Livre de Perspective de Jehan Cousin Senonois, Maistre Painctre_, published in 1560 by Jean le Royer, printer to the King for mathematics. This profession of printer for mathematics had its difficulties of engraving, for Le Royer tells us in his preface that he had himself finished the plates commenced by Albin Olivier. In another practical treatise, entitled _Livre de Portraiture_, published in 1593, John Cousin is styled _peintre géometrien_. It is beyond doubt that this master produced for many works figures and ornaments, but what were the books? The manner was then to repeat the engraved borders of titles, the _passe-partout_, in the centre of which the text was printed. Cousin designed many of these title-pages on wood; that of the _Livre de Portraiture_ affords a curious element of comparison; but he was not by any means the inventor. In 1555 was sold at Antwerp a book printed from engraved plates after John Vriedman, by Gerard Juif, which is simply a collection of engravings for title-pages for the use of publishers. [Illustration: Fig. 61.--Title of John Cousin's _Livre de Portraiture_, published in 1593 by Le Clerc. (The spot on the title is in the original, preserved among the prints of the Bibliothèque Nationale.)] It is about this time that metal plates may be seen in conjunction with wood engraving in the illustration of the Book, and the best artists attached their names to important publications of this kind. We have explained in a former chapter in what this process is least convenient in the impression of a book. In fact, two successive printings, that of the plates and that of the text, were additional trouble and a frequent cause of errors; but wood-cutting was somewhat abandoned in the middle of the sixteenth century, especially for separate plates, and engraved plates took a considerable importance under different artistic influences. The first was the facility of engraving a metal plate compared to the difficulty of cutting a wood block. It thus naturally happened that the artists of the burin wished to employ their art in illustration, and taste was soon drawn to the new process. In France the first volume of this kind was printed in 1488 by Topie de Pymont in folio: the _Pérégrinations en Terre Sainte_ of Bernard de Breydenbach, with figures on engraved plates copied from the Mayence edition of 1486. Since this manner was abandoned until about 1550, as much for the reasons given above as for others, we only meet with a stray plate now and again, which remains as a bait, and relates to nothing. Under the reign of Henri II. the smallness of the volumes did not always admit of wood engravings, and the artists in metal found a footing among illustrators; they made attempts, such as that of the _Histoire de Jason_ of Réné Boivin in 1563, which came out under Charles IX. in a charming volume of engraved plates by P. Woériot.