=Simple forms of Classification.=—The most common plan in English libraries is a modification of this scheme. The books are divided into about ten classes and the books in each class are arranged in the order in which they are received. The classes are distinguished by capital letters. An example said to be very common in England, is as follows. A. Theology and philosophy. B. History and biography. C. Travel and topography. D. Law, politics, commerce. E. Arts and sciences. F. Fiction. G. Philology. H. Poetry and drama. J. Juvenile. K. Miscellaneous and magazines. As an illustration of the way a book is marked in this scheme, B 2574 might be Green’s “History of the English people.” This book is marked B. because it is a history. It is marked 2574 because there were already 2573 books in this class at the time this book was added. This mark, B 2574, is a very simple one and to that extent satisfactory. The scheme is a great advance over the preceding one, because it brings the books of a kind together. Since there are ten classes in this scheme, it is evident that if a reader wishes to see all the books on one subject he will have to examine only one-tenth of the library instead of the whole of it, but even this is not felt to be minute enough. If the library contains 200,000 volumes one class would contain, on the average, 20,000 volumes, which is altogether too great a collection to search through. If Green’s “History of the English people” were marked B 2574, the next book might be Robinson’s “History of Peru,” marked B 2575, which is of course a very different subject. The case is still worse in class E, which includes fine arts, useful arts and all the sciences, so that a book on chemistry might stand between a book on medicine and one on Raphael. This would not satisfy the reading public of to-day,—nor the modern librarian. The classes F, fiction, and J, juvenile, are not so bad; there is not so great a difference between the books in these classes. They are used more by people seeking recreation, rather than by those looking for definite titles. Jacob Abbott wrote some two hundred juvenile books and many of these might be scattered among the large class J. In class F, fiction, the English, French, and German authors would all be thrown together. This would be a disadvantage for any one desiring to read along a particular line. =Open vs. Close Classification.=—The question of open vs. close classification is an important one. By open classification we mean one without minute subdivisions. An illustration of open classification is the scheme of ten classes described above. As an extreme case of open classification mention may be made of the theological library in which only two classes were used, the one class containing the books that were sound in their theology, the other the books that were unsound.