instead of the
most important Section number with cross references.

Collected works, libraries, etc., are either kept together and assigned
like individual books to the most specific head that will contain them;
or assigned to the most prominent of the various subjects on which they
treat with cross references from the others; or are separated and the
parts classed as independent works. Translations are classed with their
originals.

The Alphabetical Subject Index is designed to guide, both in numbering
and in finding the books. In numbering, the most specific head that will
contain the book having been determined, reference to that head in the
Index will give the class number to which it should be assigned. In
finding books on any given subject, reference to the Index will give the
number under which they are to be sought on the shelves, in the Shelf
Catalogue, or in the Subject Catalogue. The Index gives after each
subject the number of the class to which it is assigned. Most names of
countries, towns, animals, plants, minerals, diseases, &c, have been
omitted, the aim being to furnish an Index of Subjects on which books
are written, and not a Gazetteer or a Dictionary of all the nouns in the
language. Such subjects will be found as special chapters or sections
of books on the subjects given in the Index. The names of individual
subjects of biographies will be found in the Class List of Biography.
Omissions of any of the more general subjects will be supplied when
brought to notice.

In arranging the books on the shelves, the absolute location by shelf and
book number is wholly abandoned, the relative location by class and book
number being one of the most valuable features of the plan. The class
number serves also as the location number and the shelf number in common
use is entirely dispensed with. Accompanying the class number is the
_book_ number, which prevents confusion of different books on the same
subject. Thus the first Geometry catalogued is marked 513-1; the second
513-2, and so on to any extent, the last number showing how many books
the library has on that subject. The books of each section are all
together, and arranged by book numbers, and these sections are also
arranged in simple numerical order throughout the library. The call
number 513-11 signifies not the 11th book on shelf 513; or alcove 5,
range 1, shelf 3, as in most libraries, but signifies the 11th book in
subject 513 or the 11th Geometr