author_, in the vast majority of cases, wants simply the number by which
to call for it, and can find it much sooner in a brief title catalogue.
In the rare cases where more is needed the class number refers instantly
to all these facts on the cards. On the other hand, a reader
seeking books on a _known subject_, needs the full title, imprint,
cross-references, and notes, to enable him to choose the book best suited
to his wants.

The Subject Catalogue is a full title Shelf List on cards and is for the
use of the public. The Shelf List is a short title Subject Catalogue in
book form, made of separate sheets laced into an Emerson binder, and is
for official use. We thus have without extra labor, both full and short
title Subject Catalogues and Shelf Lists. The public Authors' Catalogue
is a printed volume; the official Authors' Catalogue or Index is on
cards. As a result each of the public Catalogues is checked by an
official Catalogue; each of the card Catalogues by a book Catalogue; each
of the brief title catalogues by a full title catalogue--an advantage
that will be appreciated by all librarians desiring accuracy of
administration and catalogues.

The Arabic numerals can be written and found more quickly, and with
less danger of confusion or mistake, than any other symbols whatever.
Therefore the Roman numerals, capitals and small letters, and similar
symbols usually found in systems of classification are entirely discarded
and by the exclusive use of Arabic numerals in their regular order
throughout the shelves, classifications, indexes, catalogues and records,
there is secured the greatest accuracy, economy, and convenience. This
advantage is specially prominent in comparison with systems where the
name of the author or the title must be written in calling for or
charging books and in making references.