The compilers had discovered the pernicious character of a monograph by William Camden, published in London in 1584, under the patronage of Lord Robert Cecil. Camden undertook to prove that there had been under Elizabeth no persecution of the Catholics on the ground of their faith. In the same group, finds place the title of the monograph by John Knox (but the author’s name is not given) described as _Liber Contra Regimen Feminarum_; the original English title, _The First Blast of the Trumpet against the Monstruous Regiment and Empire of Women_, is correctly printed for the first time in the Index of Benedict, 1758. The edition of the monograph that came into consideration with the Sistine compilers had been printed in Geneva in 1558. The original issue had been censured (under the directions of Queen Elizabeth) by the Archbishop of Canterbury and in 1583 was condemned by the University of Oxford. No sufficient cause appears for the prohibition of the _Chronology_ of Gerard Mercator. In 1663, the famous atlas of Mercator was placed on the prohibited list, a prohibition that was confirmed by Benedict a century and a half later. It is possible that the dedication to Queen Elizabeth of these two books may have worked to their prejudice. The introduction to the treatise _De Mundi Creatione_, which is printed with the atlas, contains some remarks in regard to the six days’ work of creation which may have been thought to be dangerous. The historians are of opinion that succeeding popes, and the Church itself, believed it to be essential for the interest of the Church to suppress this erratic and exceptional production of Pope Sixtus, and as far as any continued influence of the Index itself was concerned, such a result was certainly secured. Hilgers takes the ground that this Index, never having been published, is not to be classed as an authentic utterance of the Church. There is a curious reference, made in the Index published six years later by Clement VIII, to the intention that had been formed by Sixtus for the preparation of an Index and to the fact that he (Sixtus) had departed this life without carrying this plan into execution. The words of Clement are as follows: _Verum cum idem Sixtus, re minime absoluta, ab hominis excesserit: Nos hoc tempore omnino perficiendum atque in lucem edendum duximus._ Gregoris Lati, the biographer of Pope Sixtus, describes the special purpose of a printing-office instituted by him. The description is thought to indicate that some considerable “purification” was at times found advisable in the text of editions issued through the papal press: _Non lungi della Libraria_ [the Vatican] _vi fece fabricare Sixto una Stampa capacissima, acciò che i Libri corotti, e profanati dagli Heretici, e pieni di gravissimi errori si emendassero e si reducissero al primiero candore, ed alla prima puritá, e si rimettessero, alla loro sincera verita, stampandosi, e publicandosi con migliore ordine, e regola._[171]