The multiplying of the printing-presses and the development of machinery for the distribution of the copies of the printed books, together with the rapid increase in the public demand for such books, speedily, however, rendered impracticable the effort on the part of the Church to retain the control of book production. The Louvain Index of 1546 was, as will be noticed in the later summary of the Indexes, followed by several Spanish Indexes which were for the most part compiled and issued under the direction of the Inquisition, and during the succeeding centuries, the general control of the censorship throughout the dominions of Spain remained in the hands of the Inquisition. There was, in such an arrangement, one manifest advantage; the authority that determined the offence was the same as that which put into force the penalties that had been prescribed. As a result of this identity between the power that judged and condemned, and the power that carried the condemnation into effect, the censorship was effective throughout Spanish dominions to an extent which was never reached under any censorship machinery that was put into force in other States. A book that was condemned in Spain did actually pass out of existence, as far, at least, as Spanish territory was concerned, and a similar fate occasionally befell the author. The copies that had been printed were destroyed, and the printing or circulation of further copies was too perilous an undertaking to be ventured upon. If the Inquisition had been in a position to carry on throughout Europe, or even throughout the Catholic States, a censorship as effective as that put into force in Spain, the extermination of books would have been so considerable that there would have been brought about a serious break between the literatures of the centuries. In France, the censorship was exercised in a more fitful and less consistent manner. The Indexes originating in France were for the most part compiled, under the authority of the Crown, by the theologians of the Sorbonne. Books were, however, from time to time condemned under the direct supervision of the royal chancellor. It is to be borne in mind also that a refusal on the part of the chancellor to issue a royal privilege for a book served to prevent its publication, at least in France (the edition must as a rule have been printed before the examination of copies by the royal censors could be made), and was, therefore, practically identical with a prohibition. The title of such an unprivileged and therefore unpublished work would as a rule not find its way into the lists of the French Index. The extent of the repression or restriction of literary activity can, therefore, not be fully measured by the number of titles on the lists of works prohibited.