In the year 1869 Professor Domenico Berti obtained permission to inspect and turn to account the Acts of Galileo’s Trial carefully preserved in the Vatican, and in 1876 he published a portion of these important documents, which essentially tended to complete the very partial publication of them by Henri de L’Epinois, in 1867. In 1877 M. de L’Epinois and the present writer were permitted to resuscitate the famous volume, which again lay buried among the secret papal archives; that is, to inspect it at leisure and to publish the contents in full. It was, however, not only of the greatest importance to become acquainted with the Vatican MS. as a whole, and by an exact publication of it to make it the common property of historical research; it was at least of equal moment to make a most careful examination of the material form and external appearance of the Acts. For the threefold system of paging had led some historians to make the boldest conjectures, and respecting one document in particular,—the famous note of 26th February, 1616,—there was an apparently well-founded suspicion that there had been a later falsification of the papers. While, on the one hand, the knowledge gained of the entire contents of the Vatican MS., for the purpose of my own publication of it,[1] only confirmed, in many respects, my previous opinions on the memorable trial; on the other hand, a minute and repeated examination of the material evidence afforded by the suspicious document, which, up to that time, had been considered by myself and many other authors to be a forgery of a later date, convinced me, contrary to all expectation, that it indisputably originated in 1616. This newly acquired experience, and the appearance of many valuable critical writings on the trial of Galileo since the year 1876, rendered therefore a partial revision and correction of the German edition of this work, for the English and an Italian translation, absolutely necessary. All the needful emendations have accordingly been made, with constant reference to the literature relating to the subject published between the spring of 1876 and the spring of 1878. I have also consulted several older works which had escaped my attention when the book was first written. May the work then, in its to some extent new form, make its way in the British Isles, and meet with as friendly a reception there as the German edition has met with in Austria and Germany. To you, Madam, I offer my warm thanks for the care with which you have executed the difficult and laborious task of translation. Accept, Madam, the assurance of my sincere esteem. KARL VON GEBLER.[2] MERAN, _1st April, 1878_. NOTE BY THE TRANSLATOR.