The property that the librarian is expected to conserve consists of books--the material in which he works and with which he is expected to produce his effects, and of money and objects--buildings, furniture and utensils--intended to aid him in handling the books properly and in getting them and the users together. The Philadelphia alderman who proposed to do away with the buildings, furniture and staff of the library altogether, spend the money for books, dump these on the city-hall floor, and let the public choose, may have been somewhat crude in his ideas; but he at least understood that books are the basis of a library and that librarians and buildings are but subsidiary. His attitude was vastly more intelligent than that of some persons who appear to think that a good librarian in a fine building ought to produce satisfactory results without any books at all. The librarian, then, must provide above all for the care and preservation of the books. If his library is on open shelves it must assure careful watch against thievery; it must insure, by an adequate charging system, the due return of borrowed volumes; it must see that the physical structure of the book is protected, and repaired when needful; it must watch and count the books at intervals to see that they are all on the shelves. This last means the taking of a regular and careful inventory--the bane of the average librarian. Yet how can he shirk it? Books are valuable property entrusted to his care. If he were custodian of money or funds he would not be let off year after year with the statement that the labor of ascertaining how much remained in his possession was greater than it was worth. One may omit to inventory his private collection, just as he may omit to count the money in his purse, if he chooses, not that of others. And if it is his duty to see that the quantity of his collection remains unimpaired, it is equally so to see to the quality. A library system that counts the books carefully, but esteems a torn and filthy volume as good a unit as one in proper condition, will no longer pass muster.