In the Library of Congress, the replacement of books upon the shelves is carried out much more frequently than once daily. As fast as books come in at the central desk by the returns of readers, they are sent back through the book-carriers, to the proper floors, where the outside label-numbers indicate that they belong, and replaced by the attendant there on their proper shelves. These mechanical book-carriers run all day, by electric power, supplied by a dynamo in the basement, and, with their endless chain and attached boxes constantly revolving, they furnish a near approach to perpetual motion. Thus I have seen a set of Macaulay's England, called for by ticket from the reading-room, arrive in three minutes from the outlying book-repository or iron stack, several hundreds of feet distant on an upper floor, placed on the reader's table, referred to, and returned at once, then placed in the book-carrier by the desk attendant, received back on its proper floor, and distributed to its own shelf by the attendant there, all within half an hour after the reader's application. Another rule to be observed by the reading-room attendants is to examine all call-slips, or readers' tickets, remaining uncalled for at the close of each day's business, and see if the books on them are present in the library. This precaution is demanded by the security of the collection, as well as by the good order and arrangement of the library. Neglect of it may lead to losses or misplacements, which might be prevented by careful and unremitting observance of this rule. Another rule of eminent propriety is that librarians or assistants are not to read newspapers during library hours. When there happen to be no readers waiting to be helped, the time should be constantly occupied with other library work. There is no library large enough to be worthy of the name, that does not have arrears of work incessantly waiting to be done. And while this is the case, no library time should be wasted upon periodicals, which should be perused only outside of library hours. If one person employed in a library reads the newspaper or magazine, the bad example is likely to be followed by others. Thus serious inattention to the wants of readers, as well as neglect of library work postponed, will be sure to follow. A fourth rule, resting upon the same reason, should prevent any long sustained gossip or conversation during library hours. That time belongs explicitly to the public or to the work of the library. The rule of silence which is enforced upon the public in the interest of readers should not be broken by the library managers themselves. Such brief question and answer as emergency or the needful business of the library requires should be conducted in a low tone, and soon ended. Library administration is a business, and must be conducted in a business way. No library can properly be turned into a place of conversation.