PREFACE.

The present list, the eighth of the Library's bibliographical publications, is a new and revised edition of the first list, published in 1900. It is a catalogue of the books kept on open shelves in the general Reading Room, which are used by the public without any formality. The collection includes, besides general works of reference, significant books, both advanced and popular, on subjects coming within the scope of the Library and a few reference books on topics not directly within its field, because required by the demands of the reference work. It is not, however, a collection of "best books." Many books that otherwise would have been included have of necessity been omitted on account of the limited space available. For obvious reasons very valuable books are not placed on the open shelves, nor handbooks for engineers and draftsmen, and similar publications. Books on the medical sciences have been omitted as they are shelved in the Senn Room and have been selected on a different basis. Because of this omission, certain non-medical subjects, such as Foods, are not well represented in the present list. On the other hand a number of books have been included mainly because of the frequent calls for them. Of almanacs, yearbooks, directories, and similar publications appearing periodically, as a rule, only the latest issues are kept in the Reading Room.

The collection contains about four thousand volumes and undergoes constant revision. That it is not unsuccessful in securing its objects is shown by the fact that it and the collection in the Senn Room furnish about one-half the reading in the Library.

The selection is made primarily by the Reference Librarian, and the revision for the present edition has been the work of Mr. C. H. Brown, for whose valuable services the thanks of the Library are due.

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