[Illustration: FIG. 102.--Leyden Slip Holder (Section 283).] =283.= The slip catalogue known as the Leyden, from its first use in the University Library of Leyden, in Holland, in 1871, consists of bundles of slips, notched as shown in the illustration (Fig. 102), and secured by means of cord or catgut. The outer boards are hinged, and notched to correspond with the slips, and the cord is tied firmly round the volume and into the slots, so as to bind the whole. These Leyden holders are only adapted for private or staff use, and must be kept in very thin sections, as the volumes get more loose and insecure the thicker they are made. As a means of holding any kind of temporary slip, this is, however, a useful device. [Illustration: FIG. 103.--Volume of Staderini Sheaf Catalogue (Section 284).] =284.= A much more mechanically perfect slip catalogue-holder is the screw-binder invented by Mr A. Staderini, of Rome. It comprises a fixed back and boards, to which two iron screw-bolts are attached. On these the slips, which are perforated to correspond with the bolts, are threaded, and the books are secured by means of brass screw-caps which fasten the boards to the bolts, and so make the volume rigid and the slips secure. These volumes are numbered and kept in pigeon-holes, which bear the volume numbers and letters denoting the section of the alphabet contained in each sheaf (Figs. 103-104). [Illustration: FIG. 104.--Staderini Sheaf Catalogue in the Victor Emmanuel Library, Rome (Section 284).] =285.= A “sheaf”-holder on exactly the same principle, but with a different and neater fastening, was invented in 1891 by Mrs Sacconi-Ricci, of Florence. This holder also fits into numbered pigeon-holes, and consists of perforated slips threaded on to two upright rods, which are kept in place by means of a sliding bar which, when screwed into place, locks the slips and boards into one compact volume (Fig. 105). [Illustration: FIG. 105.--Sacconi Sheaf Catalogue (Section 285).] [Illustration: FIG. 106.--Adjustable Sheaf Catalogue, Clamp Fastening (Section 286).]