To add to the ordinary engagements of librarian, too, it was determined, sometime after Mezzofanti's appointment, to prepare a Catalogue Raisonne, in which the Oriental and Greek department naturally fell to his share. For the Oriental department of the library there seems, up to this time, to have been no catalogue, or at least an exceedingly imperfect and inaccurate one; and as a definite time was fixed for the completion of the task, it became for Mezzofanti a source of serious and protracted embarrassment, to which he alludes more than once in his correspondence.