132 CO-OPERATION AMONG 10 Mark, a periodical volume for 30 Mark, a news- paper volume or a seventeenth century volume for 50 Mark, a sixteenth century volume for 100 Mark. Sometimes even reference libraries (for instance, the Library of the Imperial Patent Office at Berlin) send books to other places and even abroad if they learn from the Information-bureau that these books are nowhere else available. III. THE PRACTICE OF THE INTER- LIBRARY LOAN SERVICE. IN order to show how the inter-library loan service works in detail, I will set out the practice of borrowing chiefly as carried on in one of the smaller non-Prussian University libraries a few years ago, and the practice of lending chiefly as now carried on in the Royal Library at Berlin, as lending prevails here and borrowing there. i. THE PRACTICE OF BORROWING. If a frequenter of the University Library, say at Jena, wants a book which is not in the library, and will not be acquired by the library, he is advised to apply to the Royal Library at Berlin, and fills in the green Berlin order slip available at Jena. Twice a week, a member of the Jena staff examines these order slips, and corrects them by the aid of biblio- graphies, as far as necessary or possible, stamps them with the library stamp, and adds his signature. He fills in a letter form asking for the books named in the order slips, and stating the number of the
