A person is always mal-employed when he is leaving a more important thing undone, to do a less important one. The degree of mal-employment in this case is measured, of course, by the difference in value between the two things. Mr. E.L. Pearson, in one of his library articles in the _Boston Transcript_, calls attention to what he names “side-shows” in libraries, and asserts that the chief business of a library, the proper care and distribution of books, is often neglected that other things may be attended to, and that money needed for books is often diverted to these other uses. This is undoubtedly true in many cases, and in so far as it is true some librarians and library assistants are mal-employed. The scope of library work has broadened out enormously of late and libraries are doing all sorts of things that are subsidiary to their main work--things that will make that work easier and more effective. This is as it should be, provided that these numerous tails do not wag the dog. To take an extreme instance we will assume that a small library is in great need of books and that a small gift of money, instead of being expended for these is put into material for picture bulletins. We should have no difficulty in concluding that the person who makes the bulletins is mal-employed; and in so doing we should not be condemning picture bulletins at all or saying that money spent for them is wasted. Take again a case specially noted by Mr. Pearson, which is bothering the heads of some of our library trustees at this moment--the acceptance and preservation of full sets of the printed catalogue cards of the Library of Congress. There can be no doubt of the value of such depository sets to certain libraries, and as they are given free of charge the only expense connected with them is the cost of an assistant’s time in filing them, amounting perhaps to an hour or two a day, and that of cabinets in which to keep them. Whether this cost is far outweighed by the usefulness of the collection to the library and its patrons, or whether that usefulness is practically _nil_, making the outlay wasteful, no matter how small it may be, must be answered by each library for itself. In some cases, labor expended on the filing of L.C. cards is undoubtedly mal-employment. Certain kinds of work which were either not mal-employment when they were adopted, or were not recognized as such, have become so by reason of a change, either in the conditions of the work itself or in the way in which it is regarded by those who are doing it and by the public that benefits by it.