It is very customary for boards of library officers to assume the charge of the administration so far as regards the library staff, and to make appointments, promotions or removals at their own pleasure. In most libraries, however, this power is exercised mainly on the advice or selection of the librarian, his action being confirmed when there is no serious objection. In still other cases, the librarian is left wholly free to choose the assistants. This is perhaps the course most likely to secure efficient service, since his judgment, if he is a person of tried capacity and mature experience, will lead to the selection of the fittest candidates, for the work which he alone thoroughly knows. No library trustee can put himself fully in the place of a librarian, and see for himself the multitude of occasions arising in the daily work of the library, where promptness, tact, and wide knowledge of books will make a success, and the want of any of these qualities a failure. Still less can he judge the competency or incompetency of one who is to be employed in the difficult and exact work of cataloguing books. Besides, there is always the hazard that trustees, or some of them, may have personal favorites or relatives to prefer, and will use their influence to secure the appointment or promotion of utterly uninstructed persons, in place of such candidates as are known to the librarian to be best qualified. In no case should any person be employed without full examination as to fitness for library work, conducted either by the librarian, or by a committee of which the librarian is a member or chief examiner. A probationary trial should also follow before final appointment. The power of patronage, if unchecked by this safeguard, will result in filling any library with incompetents, to the serious detriment of the service on which its usefulness depends. The librarian cannot keep a training school for inexperts: he has no time for this, and he indispensably needs and should have assistants who are competent to their duties, from their first entrance upon them. As he is held responsible for all results, in the conduct of the library, both by the trustees and by the public, he should have the power, or at least the approximate power, to select the means by which those results are to be attained. In the Boston Public Library, all appointments are made by the trustees upon nomination by the librarian, after an examination somewhat similar to that of the civil service, but by a board of library experts. In the British Museum Library, the selection and promotion of members of the staff are passed upon by the trustees, having the recommendation of the principal librarian before them. In the Library of Congress, appointments are made directly by the librarian after a probationary trial, with previous examination as to education, former experience or employments, attainments, and fitness for library service.