Supposing it were to become the custom of small libraries to send books and pamphlets which they can get, but do not need, to large neighboring libraries where they would be useful. Such action would lead to an exchange of various civilities. Then, too, as the desirability of having large libraries help smaller ones by loans of books becomes more and more obvious, will not persons of means give money to the former to enable them to do this kind of work for small towns generally or for particular towns in which they may be specially interested? Mr. Adams's advice to libraries is, not to accumulate books promiscuously, but to practice a systematic differentiation in collecting. Books which cumber the shelves of one library may be of the greatest value in another. The public documents only of its own town and State, and a few of the national documents relating to matters of general interest, are in place in the library of a small town. But all public documents have come to be of the greatest service in large libraries and in libraries connected with important educational institutions. Even those which seem driest, because exclusively of statistics, are much in demand in colleges where students of history and political economy are required to examine original sources. Mr. Charles A. Cutter said several years ago, regarding the proper disposition of pamphlets, that local pamphlets should be given to local libraries, professional or scientific pamphlets to special libraries, miscellaneous and all sorts of pamphlets to larger general libraries. This is excellent advice. Even large general libraries practice differentiation, many of them excluding professional books and leaving special libraries in their neighborhood to accumulate them. A State library may properly make a specialty of public documents, and perhaps law books, and pay little attention to accumulating other books. A general subscription library with a constituency mainly of people of leisure may find it more useful to collect books in belles-lettres, biography, history, travel, etc., than to buy many dealing with industrial subjects. But a public library in a great manufacturing town, or a special library for architects and engineers, must specialize on technical books. It is not proposed to destroy books taken out of libraries where they are not needed, but to place them within reach of those most needing them, either through other libraries or auction rooms or secondhand bookstores. No countenance would be given to such a proceeding as that of the administrators of the estate of the well-known collector of old books, Mr. T.O.P.H. Burnham, who are said to have sent a ton or more of material from his stock to the paper mill.[5]