bolts are likely to damage the books placed against them.
The revolving shelf-pin, shown in Fig. 10, is that supplied by the Library Bureau. It is made of metal, and allows of adjustment to two heights from the same hole, the most usual being that shown in the illustration. The second adjustment is made by turning the pin with-the projecting part uppermost. The holes for receiving the pin should be drilled in a groove broad enough to receive the square head, otherwise they may sag under the weight and slip out.
The Chivers' adjustable shelf fitting, shown in Fig. 11, consists of a metal strip and brackets. The strip is screwed to the inner side of the upright, and is raised a little from the surface by washers at intervals. The brackets which support the shelves slide up or down this strip as desired, and are held in position by an automatic device. This is one of the latest form of shelf bracket, and, as it gives absolute adjustability, it has considerable advantages over many of the contrivances in use. It has been adopted by the Hampstead Public Library, London Library, and the University Library, Aberdeen.
In Fig 12 is given an illustration of the wedge bracket. The construction will be apparent from the drawing. The bracket slides between uprights, and is held in place by two wedges, one of which has a serrated edge. When it is necessary to alter its position a smart tap given to one of the wedges loosens it, and it can then be slipped up or down as desired. The front of the
