First. The library circulates no books on plumbing. For the librarian of the day before yesterday, this is no problem at all. Probably his library has no books on plumbing. His library is not for plumbers, and he has never suspected that it could be. As for the plumbers in his community, they too have never considered the possibility that they might learn something of their work from books in a public library. They are therefore silent and uncomplaining. Peace reigns and there is a general state of satisfaction all around--the satisfaction of blissful ignorance and of the day before yesterday. The librarian of yesterday, on the other hand, sees the problem clearly and is concerned about it. He has good books on plumbing and nobody reads them. Evidently the more advanced grade of the librarian has not affected the plumbers--they still remain in ignorance of the public library. But what is he to do? Here is the library; here are the books; here is the librarian, ready and willing to distribute them to all who may come. If the generation--or any part of it--is so wicked and perverse that it comes not, what is there to do? What, indeed! And so library and community remain in the twilight of yesterday just before the dawn. The librarian of to-day not only sees the problem and is concerned about it, but he proceeds to do something. Just what he does or how he does it is of far less consequence than the fact that he sees action in the matter to be necessary and possible. He may go personally and interview the plumbers; he may send them lists; he may get permission to address the plumbers’ union; he may do one or many of a thousand things to remedy matters, and although it is certain that what he does will not be completely effective, it is equally certain that it will have _some_ good effect, which is the main thing. Problem Second. Examination of the registry list shows that there are practically no card holders in a certain part of the town. As in the former case, this is no problem at all to the day before yesterday librarian. Its existence would in general not appear to him, certainly not as the result of any kind of statistical investigation. If he were informed of it he would regard the fact with complacency. The library is for readers, and if certain persons are non-readers they had better keep away. Nothing could be simpler. The librarian of yesterday, on the other hand, feels that all is not right. It is certainly too bad that when library privileges are offered free to all, so large a portion of the community should fail to take advantage of them. The library stands ready to help these people, if they will only come. Why don’t they?