Gradually, then, the manuscript materials came in, until at last, in 1882, Mr Child felt justified in beginning to print. Other important documents were, however, discovered or made accessible as time went on. Especially noteworthy was the great find at Abbotsford (see the Advertisement to Part VIII). In 1877 Dr David Laing procured, "not without difficulty," leave to prepare for Mr Child a copy of the single manuscript of ballads then known to remain in the library at Abbotsford. This MS., entitled "Scottish Songs," was so inconsiderable, in proportion to the accumulations which Sir Walter Scott had made in preparing his Border Minstrelsy, that further search seemed to be imperatively necessary. In 1890 permission to make such a search, and to use the results, was given by the Honorable Mrs Maxwell-Scott. The investigation, made by Mr Macmath, yielded a rich harvest of ballads, which were utilized in Parts VII-IX. To dwell upon the details would be endless. The reader may see a list of the manuscript sources at pp. 397 ff. of the fifth volume; and, if he will observe how scattered they were, he will have no difficulty in believing that it required years, labor, and much delicate negotiation to bring them all together. One manuscript remained undiscoverable, William Tytler's Brown MS., but there is no reason to believe that this contained anything of consequence that is not otherwise known.[9] Meanwhile, concurrently with the toil of amassing, collating, and arranging texts, went on the far more arduous labor of comparative study of the ballads of all nations; for, in accordance with Mr Child's plan it was requisite to determine, in the fullest manner, the history and foreign relations of every piece included in his collection. To this end he devoted much time and unwearied diligence to forming, in the Library of the University, a special collection of "Folk-lore," particularly of ballads, romances, and _Märchen_. This priceless collection, the formation of which must be looked on as one of Mr Child's most striking services to the university, numbers some 7000 volumes. But these figures by no means represent the richness of the Library in the departments concerned, or the services of Mr Child in this particular. Mediæval literature in all its phases was his province, and thousands of volumes classified in other departments of the University Library bear testimony to his vigilance in ordering books, and his astonishing bibliographical knowledge. Very few books are cited in the present collection which are not to be found on the shelves of this Library.