Some day an industrious student of library economy will tabulate these things that are independent of local conditions, or so nearly so that it is better to standardize them, and tell how the others should be varied with local topography, climate and population. There is no time for that in a single lecture; and if I can leave firmly fixed in your minds the idea that some things are better standardized, while others should be functions of variable local conditions, I shall have accomplished all that I set out to do. I have already noted some of the differences between a branch library and a central library. Possibly these deserve further mention as an instance of the adaptation of methods of distribution to locality. I have frequently had occasion to deal with complaints which on investigation proved to be due to the fact that the complaining reader expected to find at a branch library all the facilities of a central library. He had lived near the central library in one city, and had moved to another where it was more convenient for him to use a branch. The first thing that strikes him is that the reference collection is inadequate. He does not realize that the central reference collection can not possibly be duplicated at branch libraries. Such complaints, however, may often give the librarian a hint. He may have equipped all his branches with the same small, good reference collection, forgetting that reference work varies with locality. Several complaints of this sort from the same branch may indicate the necessity of enlarging the reference collection there or perhaps of adopting some such scheme as we are trying in St Louis of a central reference collection of duplicates for supplying temporary branch needs. It is not always realized that the character of the book-collection in a branch library is influenced by the mere fact that it is a branch, apart from considerations of size, circulation and character of readers. There are many standard books, in small demand, that no library should be without. One copy will serve the needs of the whole town. If there is but one library there the book must form part of that library’s collection, whereas if there are a central building and branches, it should be in the central library--not in the branches. It is for this reason that the A.L.A. catalogue should not be used for stocking a branch. I know of cases where numbers of books lie idle on the shelves of every branch in a city system, because they are not branch books at all. One or two copies at Central would have been sufficient, and to place them in branches has been waste of money.