Next in order of importance come statistics of circulation. You should know how many books are given out for home use every day and how these are distributed among the classes. Do not adhere too strictly to your classification. Subdivide and combine your classes so that the results will be of interest to your particular public. Always remember in discussing these statistics that they are not so much a record of work done as a rough proportional indication of that work, and are therefore of relative, not of absolute interest. You are not to attach any meaning to the fact, taken by itself, that your circulation was 5280 for the month of May, but if you find that it was only 3120 in the previous May you may justly conclude that the work of your library is increasing. In the circulation category comes the record of the hall or library use of books, the reference use, and the books outstanding at any particular time. Hall use is very difficult to keep in a free access library, but an attempt should be made to do so. It is not quite synonymous with reference use. If a man sits down in your library and actually reads a novel without taking it home, that is hall or library use, but not reference use. If he merely refers to the same book to find out about some character, that is reference use. It is evidently hard to separate these and many libraries do not attempt to do so. In others, where there is a separate reference room, any use of books in this room is recorded as “reference use.” The number of books outstanding should be taken at least once a month, simply by counting the cards in the circulation tray. This item is very easy to ascertain, very accurate, and is interesting and useful in more than one way.