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 Geometry belonging to the library.  In finding the book, the printed numbers on the backs are followed, the upper being the class and the lower the book number.  The class is found in its numerical order among the classes as the shelf is found in the ordinary system:  the book in its numerical order in the class.  The shelves are not numbered, as the increase of different departments, the opening of new rooms, and any arrangement of classes to bring the books most circulated nearest to the delivery desk, will bring different class numbers on a given shelf.  New books as received are numbered and put into place, in the same way that new titles are added to the card catalogue.

The single digit occasionally prefixed to the book number, e.g. the 3 in 421-3-7 is the nearest height in decimeters of books too large to be put on the regular library shelves, which are only 2-1/2 decimeters apart.  The great mass of the library consists of 2-decimeter books, the size numbers of which are omitted.  Books from 2-1/2 to 3-1/2 decimeters in height have 3 prefixed to the book number, and are found on the bottom shelf of each range.  The larger sizes are prefixed with 4, 5, &c., and are found on the special shelves provided, in order to avoid the great waste of space otherwise occasioned by the relative location.  By this use of the size numbers a close economy of space is secured.

Thus all the books on any given subject are found standing together, and no additions or changes ever separate them.  Not only are all the books on the subject sought, found together, but the most nearly allied subjects precede and follow, they in turn being preceded and followed by other allied subjects as far as practicable.  Readers not having access to the shelves find the short titles arranged in the same order on the Shelf Catalogue, and the full titles, imprints, cross references, notes, &c., on the Subject Catalogue.  The uncatalogued pamphlets treating of any subject bear the same class number and are arranged on the shelves immediately after the books of each section.