The question of the most economical, and at the same time satisfactory
manner of caring for documents in a library, cannot be considered in
the space of so brief an article as this necessarily must be. After
all, it is a question that must be settled by each library for itself,
since it rests chiefly upon the extent to which the library can afford
duplication.

Depository libraries have better opportunities than others for filling
up the sheep set, and having this set they have the greater portion
of those documents useful to the average library. A complete sheep
set from the 15th Congress to the close of the 53d Congress numbers
slightly over 3343V., and will require 860 feet of shelving, or six
modern iron book stacks.

Though it is done in a few cases, the subject classification of the
sheep set is not to be recommended. Where subject classification, or
the incorporation of the documents in the general library, is desired,
the cloth set is preferable, and is in most cases procurable. If
a library can afford shelf room for both, it will be found more
satisfactory to keep the sheep set intact, and to make a selection
of such reports from the cloth set as will be locally useful to the
library.

No small library should undertake to acquire any documents but those
for which it has an actual use; only the largest libraries can afford
the task of filling up sets of documents simply for the sake of having
a complete record.

Small libraries, and all libraries in need of any special report or
document, can get it, in most cases, by applying to the superintendent