The growing complexity and diversity of library work and the multiplication of technical and other special libraries call for new types of librarian. The administrator of a large urban or rural system must be a highly educated and many-sided person. Knowledge of the relative values of books on an immense range of subjects is hardly more necessary than ability to help other persons, not only to select the right kind of books, but also to read, not at a venture, but methodically. The able librarian must have a wide comparative acquaintance with the contents and the technique of many libraries. He, or perhaps she--for women are at least as well-fitted as men for almost any kind of library work--must be a competent organizer, a good judge and controller of others, and one who can infuse keenness and interest. It is a tradition that he should be a master of the superficial, a compendium of second-hand learning, knowing something about everything; but that it would detract from his qualifications as a kind of walking index to universal knowledge, if he knew too much about anything in particular. This is an inhuman and impossible ideal. The oft-quoted dictum of Mark Pattison that the librarian who reads is lost, unless it be wantonly interpreted that we have lost the well-read librarian, is a mistaken warning. One must have a hobby for mere vitality’s sake; and, unless we specialize in something, we shall not even know what knowledge is about anything. [Illustration: _Photo by Langley & Sons_ UNIVERSITY COLLEGE, GENERAL LIBRARY.] The corner-stone of the edifice is the science and art of book selection. The librarian must be a first-class judge of books, and of books for definite use. He is to be the guide and counsellor of innumerable readers; the inspirer of untold thousands more. He should be ready at a moment’s notice to deliver a lecture on the art of reading, and, with reasonable time for preparing his notes, to conduct a tutorial class or at any rate lead a reading circle. Some specialization will give him a good start on either run. A mere smattering is not of much use in this branch of library extension work.