B305·1 Building Construction, Bibliography B305·3 -- -- Text-books, Systematic B305·10 -- -- History B329·1 Roofs, Bibliography These categorical tables are therefore of universal application, and as they contain nearly one thousand qualifying forms, phases, etc., it will be seen that their use will greatly simplify the practical work of classification. As will be seen by the above examples, the symbols of the Notation are perfectly simple combinations of letters and numbers. By treating the numbers decimally, it is possible to intercalate as many new ones as desired between any of the existing numbers, thus providing an infinity of places. The Index is very extensive in the number of subject-words it contains, and comprises practically every topic likely to be encountered in ordinary practice. The Classification Tables themselves provide places somewhere for every remote subject, and the Introduction describes how such out-of-the-way matters are to be treated. It is impossible to set forth all the features of this system of classification--its elaborate series of _biographical numbers_ for arranging Fiction, Poetry and other alphabetical classes; its new system of short _date-marks_; its rules for the _arrangement of special subjects_, authors, etc.; and its notes on the simplification of the whole subject of book classification. Reference can only be made to the Summary Table of Main Classes for an idea of the size and style of the book. SUMMARY TABLE OF MAIN CLASSES, WITH ABRIDGED NOTATION _Main Classes_ A--Generalia B-D--Physical Science E-F--Biological Science G-H--Ethnology, Medicine I--Economic Biology, Domestic Arts J-K--Philosophy and Religion L--Social and Political Science M--Language and Literature N--Literary Forms, Fiction, Poetry O-W--History and Geography X--Biography A Generalia A0 Generalia A1 Education A3 Logic A4 Mathematics A5 Geometry A6 Graphic and Plastic Arts A9 General Science B, C, D Physical Science B0 Physics, Dynamics B1 Mechanical engineering B2 Civil engineering B3 Architecture B5 Railways, Vehicles B6 Transport, Shipbuilding B8 Naval and Military science C0 Electricity C1 Optics C2 Heat C3 Acoustics C4 Music C8 Astronomy D0 Physiography D1 Hydrography, Hydrostatics D2 Meteorology, Pneumatics D3 Geology, Petrology D4 Crystallography, Mineralogy D6 Metallurgy, Mining, Metal trades D7 Chemistry D9 Chemical technology E, F Biological Science E0 Biology E1 Botany E2 Cryptogams E3 Phanerogams F0 Zoology F1 Metazoa F2 Mollusca F3 Insecta F4 Pisces (Fishes) F5 Reptilia F6 Aves (Birds) F7 Mammalia