t instruction, perpetually need to be instructed themselves, with
fuller knowledge upon the themes they are daily called upon to elucidate.
There is no text-book that can teach all, or anywhere near all there is
upon the subject it professes to cover. So the library, which has many
books upon that subject, comes in to supply its deficiencies. And the
librarian is useful to the professors and students just in proportion as
he knows, not the contents, but the range of books upon each subject
sought to be investigated. Here is where the subject catalogue, or the
dictionary catalogue, combining the subjects and the authors under a
single alphabet, comes into play. But, as no catalogue of subjects was
ever yet up to date in any considerable library, the librarian should be
able to supplement the catalogue by his own knowledge of later works in
any line of inquiry.

The most profitable studies carried on in libraries are, beyond all
question, what we may term topical researches. To pursue one subject
though many authorities is the true way to arrive at comprehensive
knowledge. And in this kind of research, the librarian ought to be better
equipped than any who frequent his library. Why? Simply because his
business is bibliography; which is not the business of learned
professors, or other scholars who visit the library.

The late Librarian Winsor said that he considered the librarian's
instruction far more valuable than that of the specialist. And this may
be owing largely to the point of view, as well as to the training, of
each. The specialist, perhaps, is an enthusiast or a devotee to his
science, and so apt to give undue importance to the details of it, or to
magnify some one feature: the librarian, on the other hand, who is
nothing if not comprehensive, takes the larger view of the wide field of
literature on each subject, and his suggestions concerning sources of
information are correspondingly valuable.

In those constantly arising questions which form the subjects of essays
or discussions in all institutions of learning, the well-furnished
library is an unfailing resource. The student who finds his unaided mind
almost a blank upon the topic given out for treatment, resorts at once to
the public library, searches catalogues, questions the librarian, and
surrounds himself with books and periodicals which may throw light upon
it. He is soon master of facts and reasonings which enable him to start
upon a train of thought