Conformity in general to the Library of Congress headings was my aim, and in most cases of doubt the usage of the Library of Congress, if known, was the determining factor in the decision. But when, fortified by the approval of such advisers as were available, including in important cases the member of the Publishing Board who is now president of the American Library Association, I was convinced that some other form of entry would be more helpful to the users of a public library, I adopted that form, even though inconsistent--as in the treatment of English language,--or not altogether accurate--as in the substitution of Corn and Rubber for Maize and India-rubber. I may add that in no case did I decide in opposition to the majority of the members of the advisory committee, though only a few specific headings were submitted to them. The list, being prepared for moderately large libraries, contains many headings that may well be ignored by the smaller libraries. Not only are most of the subdivisions unnecessary, but so also are many distinctions which would result in separation of material that might better be kept together if the entries are few, such as Charity organization, Infants (Children being a sufficient entry), Soil absorption, Soil moisture. The list is not intended as a guide to be followed blindly, but to be adapted to individual needs, by the exercise of common sense--perhaps the most necessary part of a cataloger's equipment. Consideration of cost and weight of the book necessitated limitation of the scope. There was a strong plea for the inclusion of geographical terms, at least in cases of disputed spelling. A list of such names was prepared by Miss Crawford, with full references and definitions. It was estimated that this list would add perhaps one hundred pages to the book, and the Publishing Board did not feel that it was advisable to include them. Very many headings that might be considered as falling within the scope of the book were omitted because their use would be infrequent, and it was thought better that the occasional cataloger should write these headings on the blank pages, rather than that all should be required to pay for an unnecessarily long and correspondingly heavy list.