Even after the new list was begun, it was found impossible to dispense with the "Additions and corrections" lists, as the library catalog grew and expanded. We have continued to issue them from time to time, as occasion has demanded, and have included in them new headings in the section of the alphabet not yet printed, as well as additions to the letters which have already appeared in print.
Each "Additions and corrections" list is cumulative, as far as the additions are concerned, so that a library possessing the main list and the latest supplementary list has a complete record of all the Library of Congress headings which have been printed. As was the case in the lists supplementary to the A. L. A. headings, the corrections noted appear but once, and should be carried over by catalogers to the main list of subject headings.
The classification numbers, and cross references to related subjects, known as the "See also" references, are not included in the supplementary lists. Direct "See" references from one subject to another, or from one form of name to another, are, however, usually included, that the cataloger may avoid the pitfalls lurking for the unwary.
Including the early supplementary lists, there have been, up to the present time, eight lists of "Additions and corrections" issued, and number 9 is ready for the press.
Having now touched upon some general features in regard to the issuing of the list of subject headings, with its supplementary lists, I will conclude with a word as to a later and fuller edition. The list now being issued is a preliminary list, printed as manuscript, and, to some extent, experimental in its nature. While it is being made as complete and inclusive as present conditions seem to warrant, the intention has been to reissue it later in book form, wider in its scope and more inclusive in its references. Concerning the date of issue of the fuller edition, should this desired consummation be brought about, it is impossible at this time to make a statement. Probably it will be best to wait until the remaining classes of books in the library are reclassified and re-cataloged, before any definite decision as to date is reached.
It has been suggested that the next edition of the list might be put into loose-leaf form, with a view to keeping it to date by inserting new leaves, when necessary, in place of old ones. Experiments may be tried along this line, and the relative merits of the various loose-leaf binders investigated. The advocate of this plan suggests that the Linotype slugs be kept standing, and that once a month the sheets on which changes have been made be reprinted, and distributed to the catalogers at the Library of Congress, and to subscribers to the list.
The subject matter of a later list would doubtless agree with the present list in general features, but some minor changes might be found to be desirable. One point to which our attention has been called is the possible advantage of entering subjects in zoology and botany in the plural form rather than in the singular, as most of them have been entered in the present list. Another matter which merits consideration is the substitution of subdivided headings for the inverted forms now in use in certain classes of subjects, as in the headings Oxygen, Physiological effect of, and Man, Origin of. Some other questions to be considered are as to whether it would be advisable to distinguish in the list those subjects which are divided by country and then by city, from the subjects which have direct local subdivision; whether certain classes of headings now included could be advantageously dispensed with; and whether the main subdivisions of the animal and vegetable kingdoms are a valuable feature of the list.
Doubtless other matters will suggest themselves for consideration as time goes on, and we shall hope eventually to publish a list which may commend itself as a valuable tool to library workers. Borrowing the words of Mr. Charles A. Cutter in the preface to his "Rules for a dictionary catalogue" we may say with him: "It is to be expected that a first attempt will be incomplete, and we shall be obliged to librarians for criticisms, objections, or new problems, with or without solutions."
It had been hoped that Mr. J. C. M. Hanson would personally supplement this paper by an informal account of the early practice and experimentation of the Library of Congress. In his unavoidable absence, brief extracts from a personal letter were read by Miss Thompson, who then called upon DR. E. C. RICHARDSON, librarian of Princeton university, to open the discussion with some previously prepared notes on
FUNDAMENTAL PRINCIPLES OF CATALOGING