Page:The Library, volume 5, series 3.djvu/134

 122 CO-OPERATION AMONG by means of a gelatine plate. Such cards (the so- called ' search-cards ') in a cover are daily sent to the ten Prussian University Libraries, as far as the incomplete Central Catalogue does not yet afford the desired information, and also to a number of other libraries likely to contain the required book, especially to the Munich Library. In the respec- tive libraries the cards are compared with the catalogues. In a non-Prussian University library I happen to know that an official accustomed to spend several hours daily in looking out the books ordered by readers, spends three-quarters of an hour or so daily on the search-cards. The Prussian University Libraries return all cards with their answer, positive or negative ; the other libraries only those asking for books which they possess. The cards of the first description are returned in a cover, and so their back may be used for a second question. The other cards have the printed address of the bureau on their back, so that the library which has a copy of the required book has only to add its own name, its stamp, and its press- mark. In cases where these efforts do not succeed, the titles are combined to form search-lists. Each c Suchliste ' enumerates books of the same kind, e.g. scientific books, French books, etc. These search-lists are sent to all the supporting libraries likely to contain the required books, and they are also published in the ' Literarisches Zentralblatt.' When the researches have been finished success- fully or unsuccessfully and the book is not yet in the Central Catalogue or the Supplement Catalogue, one copy of the search-card reserved for this pur-