[Illustration: FIG. 34.--Details of Lambert’s Adjustable Metal Shelving (Section 149).]
=150.= A special form of this type of metal bookcase has been designed for book-storage in small spaces, and as applied to the India Office Library, London, and Bodleian Library, Oxford, has been found convenient and economical. The same shelf adjustment is used, but the presses instead of resting on the floor are swung from iron girders, so as to slide easily whenever wanted. These presses are swung closely side by side and drawn out, one at a time, as required.
A somewhat similar plan for increasing the storage capacity was introduced into the British Museum many years ago, the chief difference being that the sliding presses go face to face with the existing standards, one here and there, instead of in solid rows as at the India Office.
[Illustration: FIG. 35.--Metal Shelving, Patent Office Library, London (Section 149).]
=151.= It is not proposed to describe every variety of iron or metal bookcase which has been introduced, such as the Library Bureau, Smith, Lawrence, Cotgreave, etc., and it will be sufficient to mention that in Britain, Germany and America there are several interesting forms used.
=152. Special Bookcases.=--In Section 146 a form of special wall-case is described which is suitable for storing folio and quarto volumes. In very large libraries it may be necessary to provide additional storage space for bound files of newspapers, extra large folios and prints. Files of newspapers can be stored in a special form of double rack, as illustrated in Fig. 36. As small libraries will bind only the files of local papers, the provision by them of shelves for this purpose need not be a very serious matter.
=153.= Large folio volumes are best kept flat on sliding trays or shelves. When they are kept upright they are very apt to suffer through the heavy leaves sagging and dragging at the binding. Valuable folios should always be kept in flat positions. A suitable method of storage is to provide a large double-sided case, with a sloping top, which can be used for consulting the books. The shelves should be arranged to slide out and in on runners, and each shelf may have a brass handle on its fore-edge to enable it to be easily pulled out. The dimensions of such a case will depend upon the number of folios to be stored and their size, but the following illustration (Fig. 37) will be found suitable for all ordinary purposes.