The poverty of our American libraries in research books is a matter of almost daily observation in research libraries. We are rich in the books for learning and teaching, that is, in all the machinery for spreading common knowledge; but when it comes to the search for new knowledge, those sciences which, like history and philology, find their chief sources in books, are handicapped at every turn. It was estimated three or four years ago that there are at least five million live research books in the world, i.e., books liable to be sought at the reference desk any day. Of these it was said perhaps one million can be found in the great reference libraries, another million exist in America somewhere, if only they could be located, and the rest are only to be found abroad. Since that time it has been found that both the number which can be found and the number, in America which might be found are increasing rapidly, but the problem is still very far from approaching solution. Every few weeks, if not oftener, any one actively engaged in research work runs up against a concrete instance. The writer has already met several during the first month of the academic year. The most recent is as typical as any.