=The Main Catalogue= is a record of the works in the library. It gives an entry under author, under title, if distinctive or in case of periodicals, and also under specific subject or subjects if the books have been classified according to the Library of Congress scheme. For example, James Allan’s “Under the dragon flag” (reclassified) is entered in the catalogue under Allan, James; by title: Under the dragon flag; and by subject: Chinese-Japanese war, 1894-1895. Thus there are three avenues of approach, one for the reader who knows the author’s name, another for the reader who remembers the title, but cannot recall the author, and a third for the reader who wishes something on the Chinese-Japanese war and has no definite book in mind. Books not classified by the Library of Congress scheme but still under the Rowell classification have the usual author and distinctive title cards in the main catalogue, but in place of a subject entry will be found a reference from the subject to that number in the classed subject catalogue where it will be found. For example, Freud’s “Interpretation of dreams” appears in the main catalogue under Freud, Sigmund, and under Interpretation of dreams; but instead of appearing under the subject Dreams there is a reference card under that word which reads: Dreams, see subject catalogue under 11 _d._ On turning to the subject catalogue at that number the reader finds not only Freud’s book, but all other books in the library on the subject of dreams. =The Classed Subject Catalogue= occupies one face of the two cases nearest the entrance to the Reference Room and covers only the subjects still under the Rowell classification. It is a numerical arrangement of the cards in the order in which the books stand on the shelves i.e., all cards on a given subject are grouped together under one number. Indexes in book form referring from subject to number are to be found on the tables reserved for consulting the catalogue. The reader wishing books on meteors, for example, finds in the index opposite the word meteors the number 369. He turns to the classed subject catalogue at that number and sees there the library’s resources on that subject. He will also find in the main catalogue under the word meteors, a reference card: Meteors, see subject catalogue under 369. So whether he consults the printed index or the main catalogue, he will be referred to the same place in the classed subject catalogue. =The Call Number= (which indicates the classification and the shelf location of the book) is in the upper left hand corner of the catalogue card. It must be exactly copied in the corresponding place on the call slip to enable an attendant to find the book.