ely most
people carry on their mental processes in accordance with certain
uniformities. Under this uniformity of thought no patentable
relationship may be alleged between a quarto volume and the subject of
history or between a leather binding and the German language; wherefore
4 classes of coordinate value, based on the 4 characteristics, each
divided into 4 subclasses, 16 divisions in all, may serve the purpose of
a Patent Office search. But if, as sometimes happens, a patentable
relationship had been assumed and admitted between a leather binding and
any of the languages, or any of the subjects, or between any two or more
of those different characteristics, provision could be made for such
combinations by the following expedients:

(1) Arrange the characteristics, in the order of relative significance
or importance for the purpose in view, in four groups, giving each group
the characteristic title. Under each title arrange the varieties in a
similar relation as follows in either (1) or (2):

(1) (2)
Cl. X.--BOOKS. Cl. X.--BOOKS.

0. Miscellaneous. 1. Subject-matter--
0.5 Subject-matter-- 2. History.
1. History. 3. Science.
2. Science. 4. Art.
3. Art. 5. Fiction.
4. Fiction-- 6. Language--
4.5 Language-- 7. English.
5. English. 8. German.
6. German. 9. French.
7. French. 10. Spanish.
8. Spanish. 11. Size--
8.5 Size-- 12. Folio.
9. Folio. 13. Quarto.
10. Quarto. 14. Octavo.
11. Octavo. 15. Duodecimo.
12. Duodecimo. 16. Binding--
12.5 Binding material-- 17. Leather.
13. Leather. 18. Rawhide.
14. Rawhide. 19. Cloth.
15. Cloth. 20. Paper.
16. Paper.

Subject-matter, assumed to be the most important characteristic, is
placed first. Any exhibit of mere material for binding, mere size, mere
language, or mere subject-matter, would fall into the correspondingly
entitled group. If, however, a book on history in German or a history in
red leather, etc., were to be classified, it w