PLAN The Author Catalogue is the first and most co . Authors are, ar ranged in strict alphabetic order like a diction ary. and under each author are further arranged alphabetically by titles all works by him which the library possesses. A separate title catalogue is rarely made: yet titles must be given for anonymous publications, and also for books hav ing titles specially likely to be remcmhered. These are usually inserted in the same alphabet with authors, The Subject Catalogue has now come to he regarded as essential as the author catalogue. It alone can tell what the library has on any subject. and obviously its educative value is very great. There are three distinct types: (1) c/assta.—This has all subjects ar ranged in logical order, and to be conveniently usable must employ a system of notation with numbers or letters referring to each specific subject instead of to pages, and an alphabetic index where the most minute topic will be found followed by this number. (2) Alpha betico dassed.—In this the main subjects are in alpha betic order, and under each iu sub-alphabets are divisions and sections, so that the catalogue is its own index. Cross-references may be inserted at any point, so that a topic can surely be found from the main alphabet without a subordinate index. (3) Diet ionary—This is naturally the most common type of catalogue, and its use has been growing steadily for a generation. It in troduces specific subject entries in the same alpha bet with authors and titles, thus making simple dictionary order. The easy rule to consult it like a dictionary, whether author, title, or subject is sought. appeals strongly to most readers. In spite. however, of its apparent simplicity, it requires the greatest skill to make, and while un excelled for reference to a single topic, which is most common in popular libraries. in its nature it cannot put before the reader the resources of the library on generic subjects with the clearness or helpfulness of the classed catalogue.
If one wishes to see all the geometries in a library, direct reference to this word under the dictionary gives them as well as would sim ilar reference to "Geometry" in the classed cata logue, hut in the dictionary these are preceded by e.g. "Geology" and followed by "Geoponieon
in sermanem Syriaeum versornm supersunt." In the classed catalogue, however, geometry is preceded by algebra find arithemetie and followed by trigonometry, calculus, and the other subjects most nearly related. If one wishes to see the mathematics of the library he must look in the dictionary under a dozen distinctly different heads to collect his titles, while in the classed catalogue they stand close together in logical order. If one makes a dictionary catalogue un der the simple rule to write the subject at the head of the card and drop it into alphabetic order, the result will be largely worthless. It requires. like the class catalogue. a carefully elaborated ,-y.trin worked out in advance and scrupulously followed. otherwise books on the identical subject will be scattered all over the alphabet by the ac eident of the first word or of the word that hap pened to be in the cataloguer's mind when writ ing the headings. A book discussing protection and free trade might appear under P. F. or T. or under Tariff, Revenues. Subsidies, Customs. Du ties, or other heads. All things considered, the merits of the two systems are well balanced. In the smallest library the classed list appeals strongly to teachers and others interested in the educational work of the library. because they know what its influence will be on inexperieneed readers. Its large libraries the classed form ap peals to students and investigators who study not only speeifie. but generic and appreciate keenly the practical advantages possible only with an arrangement which follows the natural rela tion of subjects to each other rather than the purely accidental order of the alphabet.
Bturaocaarny. Illaekbu•n. Cam/of/1w Titles, Index Entries (London. 1884) Cutter. Rules for a Dictionary Catalogue (Washington. 1891); Dewey, Simplified Library School Rules (Bos ton. 1S09) : id.. Dtcitnal Classification (Boston. 18851 Linderfelt, &feet le Carr/ Catalogue Rules, Author and Title Entries (11o;ston. 1890) ; Quinn, Manual of Library Cataloguing (London, ; Wheatley, //ow to Catalogue it Library Landon. 1889) : Riehardson.•Classification, Theo retical and Practical (New York, 1S91).