Page:Popular Science Monthly Volume 61.djvu/533

Rh Mathematics has a relatively large circulation, but we must not suppose that in May, 1901, 673 citizens of New York devoted themselves to the theory of functions or the calculus of probabilities. Further analysis would reveal the fact that a very large proportion of the books taken out were text-books on arithmetic and algebra.

An examination of the records of the separate libraries reveals some points of interest. For instance the circulation in political science and political economy at Bond Street was twice as great as at Bloomingdale—five miles above. The proportion of Hebrews among the users of the two branches must be in nearly the same ratio—a fact that speaks for itself. On the other hand the circulation in education was larger at Bloomingdale. In English philology, the Chatham Square Branch circulated nearly as many books as all the other branches together, which is noteworthy when we remember that this is in a foreign section, where there are news-stands on which not a single English newspaper is exposed for sale. The same proportion holds good at this branch for general works on natural science (class 500). Some things about the table are inexplicable. Why, for instance, should the Ottendorfer Branch have circulated twice as much zoology as Bond Street, only a half mile distant? Doubtless this was owing to some temporary demand, which another month's record might reverse.

Comparison of the circulation in each class with the number of books in that class shows, as might have been expected, that the larger the stock the larger the circulation. There is a mutual reaction between these two numbers. On the one hand, if the demand for a particular class of books is not great, in any branch library, that library naturally does not call for books on that subject; on the other hand, if a library is meagerly supplied in any subject, so that users who wish to read in that subject can not get what they want, the circulation is apt to remain small. In such cases the circulation may be raised by replenishing the stock. The ratio does not always hold good, however, and there are some notable exceptions.

Evidently these are but a very few of the considerations suggested by a study of the table. Different parts of it will naturally interest different readers, and each will be able to find may things in it that can not be brought out here. Of course the record for a whole year would be still more valuable, but, as has been said, the amount of daily labor necessary to subdivide the report is so great that its continuance beyond a month would hardly be justified. So far as I know this is the first attempt made in any library to subdivide so closely in any subject and to present the results in a form suitable for observation and study.