That portion of his responsible task which pertains to the arrangement and classification of books has been elsewhere treated. But there is required in addition, a faculty of arranging his time, so as to meet seasonably the multifarious drafts upon it. He should early learn not only the supreme value of moments, but how to make all the library hours fruitful of results. To this end the time should be apportioned with careful reference to each department of library service. One hour may be set for revising one kind of work of assistants; another for a different one; another for perusing sale catalogues, and marking _desiderata_ to be looked up in the library catalogue; another for researches in aid of readers or correspondents; still another for answering letters on the many subjects about which librarians are constantly addressed; and still another for a survey of all the varied interests of the library and its frequenters, to see what features of the service need strengthening, what improvements can be made, what errors corrected, and how its general usefulness can be increased. So to apportion one's time as to get out of the day (which is all too short for what is to be done in it) the utmost of accomplishment is a problem requiring much skill, as well as the ability to profit by experience. One has always to be subject to interruptions--and these must be allowed for, and in some way made up for. Remember, when you have lost valuable time with some visitor whose claims to your attention are paramount, that when to-morrow comes one should take up early the arrears of work postponed, and make progress with them, even though unable to finish them.