HISTORY AND GEOGRAPHY.--Historical works which are mere résumés, and not themselves original authorities, may be discarded with comparative safety; but the matter of illustrations again applies here with considerable force. Works of travel of the ordinary globe-trotting description may be discarded when ten years old, along with all kinds of guidebooks, save those which are local. But here, again, beware of discarding illustrated books. Pioneer works of exploration should be retained. Old gazetteers are, as a rule, lumber, but some of the illustrated ones, like Lewis’ for Britain, may be retained for their armorial illustrations. Histories which are literary classics, like Hume, Robertson, Clarendon, should be kept, even if superseded by more accurate modern works. BIOGRAPHY.--Collected biography should never be discarded. The biographies of nonentities in the individual biography class may, however, be weeded pretty freely and frequently after they are from forty to fifty years old. MISCELLANEOUS.--Discard old encyclopædias with care; newspapers or directories freely. Retain all local matter of this kind however. Be extremely chary about storing inferior magazines of the miscellany order. A long set of an old magazine of this kind is a positive incubus, and most modern magazines of the snippet order are not worth house-room. Wear them out in the reading rooms by all means, but do not preserve them. GENERAL.--All works that are defective or dirty should be discarded, or at any rate withdrawn from general circulation. A book defective in a plate or a section or two can sometimes be completed by an application to the publisher for the missing part, which is usually forthcoming at small cost. Dirty books are the bane of municipal lending libraries, and a ruthless policy in regard to them is a public economy. Especially does this remark apply to classic fiction: clean, or fresh, copies should always be available, even if at the cost of obtaining fewer works of inferior fiction. Many of the criticisms levelled at libraries have been due to neglect of this matter; sometimes due, we are sorry to say, to want of money to buy the necessary replacements.