Of the many advantages to the teaching and study of history which might be expected to accrue from the general provision of such facilities as have here been indicated--economy of physical effort, more accurate study of texts, improved note-taking and care of material, wider use of books and illustrative helps, general compulsory map-drawing, and many others--one in particular deserves more than passing mention. I refer to the change which would thereby be furthered in the prevailing conception of the nature and function of the university library. With only the exceptions that prove the rule, our libraries are supported and administered on the assumption that one copy of a book is sufficient for the needs of the whole institution, and that every one who has occasion to use the book must seek it at the main or central repository. It would seem to be obvious, however, that wherever books form the fundamental material for study, and, from the nature of the case, cheap reprints of selected texts or a few duplicates of inexpensive volumes will not suffice, the library has need of as many copies of a book as there are departments to use it; and that if, with but a single copy available, resort must be had by every one to the central library, the conflicting and often irreconcilable demands of different departments present one of the most serious barriers to the development of proper methods of instruction in non-laboratory subjects. No modern department of biology is asked to get along with one microscope, and that, perhaps, of ancient pattern and in bad order. Scientific apparatus in all lines is freely duplicated as a matter of course, the adequacy of the supply being not seldom used as an advertising argument to attract students; though, as a matter of fact, there is but little greater need for duplicate apparatus than there is for duplicate books. Practical considerations, of course, will preclude extensive duplication of large or costly sets, but a multiplication of copies far beyond what is now usual, and their distribution among the various departments having constant need of them, are necessities to be met if waste is to be stopped.