I do not intend to dwell on the case where the books in a library are themselves treated as museum objects, although possibly this is the one that may first occur to the mind in this connection. Books that are curiosities on account of their rarity or for other reasons are limited usually to very large libraries. The Lenox Library in New York, now part of the Public Library, was almost entirely a book-museum and was so intended by its founder. The private libraries of great collectors, such as J. Pierpont Morgan, or the Huntingtons, are often largely book-museums, and in general, a book that brings a high price, brings it for its value as a curiosity, not as a book. The freer a book is the more value it has as a book; the more restricted it is the greater its value as a curiosity. Of course, even a small library may have one or two books that are worth display as curiosities, because they are old, or rare, or have interesting local associations either through the author, or the owner, or in some other way. The Hawthorne and Longfellow room in the Bowdoin College Library is an example of this latter case. But a book, or anything else, owned and displayed as a mere curiosity, is of not much real value, no matter what price it may bring at auction. The things that make a good museum what it is are not curiosities at all, in the vulgar sense. They illustrate some science or art and make its study easier and more interesting; they throw light on geology or history or sculpture. Once in a while we see a museum collection of books made for this object, to illustrate the art of binding or the history of printing, or the depredations of book-eating insects. The value of specimens like these has nothing to do with their rarity. Sometimes the smallest library may have books or pamphlets that may be displayed with this object, especially where the subject is local. It may for instance gather a collection of early pamphlets from local printing offices, or of books once the property of some eminent citizen. These things belong to a museum pure and simple, which is the reason why I am mentioning them at first, to get them out of the way before treating my real subject, which is the debateable ground between library and museum. There is nothing debateable about a book-museum any more than about any other kind of a museum--a collection of historical or geological specimens, for instance, that often finds place in a library building, not because it is a library, but because it is a convenient place, or because it has been thought best to build a library and a museum under one roof, as has been done in Pittsburgh.