In addition to the characters already mentioned, he greatly improved the Greek letter of the day. The _Christianæ Pietatis Prima Institutio_, printed by him in 1578, is in a beautiful type, which is considered to be equal to that of the great Greek typographers of Paris—the Estiennes. Among his further enterprises in letter-cutting may be mentioned the Hebrew words, cut in wood, which he used in Humphrey’s _Life of Jewell_, in 1573, and in Baro’s _Readings on Jonah_, in 1579; and the musical notes which he introduced into his editions of the metrical _Psalter_. These notes are chiefly lozenge-shaped and hollow, differing from those used by Grafton in 1550, in Merbecke’s _Booke of Common Praier_, _noted_, which are mostly square and solid. He also, as he himself stated in a book printed in 1582, “caused a new print of note to be made, with letters to be joined to every note, whereby thou mayest know how to call every note by its right name.” Besides these, he made use of a considerable number of signs, mathematical and other, not before cast in type; while his works abound with handsome woodcut initials, vignettes and portraits, besides a considerable variety of metal “flowers.” Of the disposal of Day’s punches and matrices after his death we have no precise information, but the reappearance of the beautiful Double Pica Roman and Italic of the _Ælfredi_, in the _Bibles_ printed by the Barkers, in Young’s _Catena on Job_ in 1637, in Walton’s _Polyglot_ in 1657, and other works, most of them executed by the royal printers, suggests that these founts at any rate were retained (probably under archiepiscopal control), and handed down for the service of the privileged presses. [Illustration: 19. Portrait of JOHN DAY, 1562. (From the Colophon to Peter Martir’s _Commentaries on the Romans_, 1568.)]