Chapter XVII: Section 145: are usually divided down the middle, at the back of each set

of shelves, by means of a wire-work grill. This does not obstruct oversight, light or air, yet serves to prevent books on one face of the standard from being accidentally or otherwise transferred to the opposite face. There are points of safety, convenience and adjustability about metal bookcases which make them preferable to all other forms.

=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.

=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.

This case will store about 150 to 200 folio volumes, according to their thickness, which is ample space for all ordinary municipal public libraries. The shelves of this case should be covered on their upper surfaces with leather or thick cloth. A similar style of rack can be used for storing large collections of prints, the only difference being that the prints would be kept in special boxes as described in Section 307, which would take the place of volumes.

=154.= In calculating the number of volumes which can be shelved in a given space, the following general rules will be found fairly accurate:--

Nine lending library books will occupy one foot run of space.

Eight reference library books will occupy one foot run of space.

Allowance must be made, in calculating from plans, for the space occupied by uprights, etc., and care must be taken to reckon dwarf bookcases only according to their capacity. If nine inches are allowed as the average height of books, which will give eight shelves to a tier seven feet six inches high, excluding cornices, plinth or thickness of shelves, then a single-sided case of the dimensions shown in Section 146 will store 216 volumes in a lending library and about 192 in a reference library. A double-sided case will hold 432 and 384 volumes respectively.

=155. Racks for Filing.=--Wooden racks or iron-pipe racks may be used for a variety of purposes, such as storing unbound newspapers and periodicals, pamphlets, and all kinds of loose papers or bundles. Such racks are best made in a light, open form, so as to reduce the collection of dust to a minimum, while admitting air and light freely.

=156. Galleries.=--Galleries of iron are sometimes added to reference libraries and in other departments to provide a means of reaching high wall-shelves, and also to give additional accommodation for storage. They are a feature of the large stack rooms of American libraries, wherein the books are all massed together, gallery above gallery and tier above tier. Unless there is some very strong reason, architectural or otherwise, galleries should be avoided in every public library where rapid service of readers is necessary. Save for storing little-used stock, galleries are not recommended in any situation, unless the pressure for book space is very great. When galleries must be provided, care should be taken to provide adequate approaches. If a straight staircase is out of the question, a circular iron one should be provided, wide enough to enable an assistant to go up or down comfortably with an armful of books. In some libraries the circular iron staircases are more like exaggerated corkscrews than proper means of getting up and down from a gallery or floor. It is much better to have stairways in a single flight, which will allow of two persons passing each other, and for this purpose they ought to be at least three feet wide.

In libraries with bookcases of the uniform height of seven feet six inches, long ladders will be unnecessary, but in cases where they must be used, step ladders are preferable to rung ones. A light form of step ladder which is used in many public libraries and shops is illustrated (Fig. 38). For all practical purposes this ladder will be found ample.

Short steps for enabling the upper shelves of seven foot six inch cases to be scanned easily are made in various forms, some being folding and others fixed. The variety as illustrated (Fig. 39) will be found useful.

=157.= In some open access libraries it has been found advisable, in cases where the top shelves are out of reach, to provide a continuous fixed step of wood or iron at the base of each bookcase, to enable readers to reach the upper shelves without using movable steps of the sort figured above. A strong, wide iron rail projecting about four inches or six inches from the case, about nine inches or twelve inches above the ground, has been found useful, especially when associated with a handle fastened to the upright at a convenient height above. The illustration (Fig. 40) will give an idea of such a continuous step and handle applied in wood.

=158.= Detached steps secured to the uprights of bookcases, combined with handles, are very often used for staff purposes in place of the ordinary movable wooden steps or ladders. There is one form with an automatic adjustment which enables the step to spring up flat against the upright out of the way when not wanted as figured in illustration (Fig. 41). It is not necessary to fit this into the uprights, and to cut away the woodwork in order to let it into its place. There is still another variety, used at Hull, Kilmarnock, etc., which is always in position for use, but which also possesses an automatic adjustment enabling it to be brushed aside harmlessly by anyone passing, and to return to its “ready” position at once. This form can be attached to any ordinary wooden upright by means of screws, without cutting away or fitting. The handle supplied with this has a superior shape and grip (Fig. 42).