120 CO-OPERATION AMONG in 1912-13 one ' Bibliothekar,' one clerk, three (lady) assistants, and one attendant had to deal exclusively with the information work. Both are also closely connected with the Royal Library and are housed in the new buildings of the library. The salary for a Prussian Bibliothekar at Berlin is 4,000 - 8,500 Mark. The other annual expenses in 1912-13 were: 6,300 Mark for the clerk and the assistants, 2,600 Mark for the attendant and the office expenditure, and 500 Mark for bibliographies in course of publication. The office contains : 1. The Prussian Central Catalogue on cards (3ist March, 1913* about 1,250,000 cards). 2. The so-called 'Supplement Catalogue' (3ist March, 1913 about 33,000 cards), which records all books not to be found in any of the eleven libraries. It is chiefly built up from the search- cards (see below). By a special arrangement in connection with the re-cataloguing of the Royal and Provincial Library at Hanover (which is done by comparing the old Hanover title entries with the more correct modern ones of the Central Cata- logue) 1 it will moreover record all books which are in this library, but in none of the eleven. A small part of the Leipsic Library Catalogue has also been compared with the Central Catalogue. Cards explaining difficult abbreviations of titles or correfting incomplete or wrong titles in references 1 Cf. K. Kunze, 'Die Neukatalogisierung der Koniglichen Bibliothek Hannover': Zentralblatt,' 26, 1909, p. 394-407.
