280. An Italian card tray on a somewhat similar principle to this was invented by Mr A. Staderini, of Rome, in 1890. It differs from the Bonnange tray in having a sliding-block gearing with a ratchet which is fastened along the bottom and made to engage or disengage with a key. The cards are similar in principle to those of the Bonnange system, save that the lower hinged half is not slotted. The illustration ([Fig. 100]) will explain better than words the appearance and other accessories of this tray.
Fig. 100.—Staderini Card Trays and Hinged Card ([Section 280]).
Both the Bonnange and Staderini methods share in common an advantage of some importance, viz., the clamped lower portion of the card forms a counterfoil to show what has been taken, should a card by accident or design be removed or torn off. The accession number or brief title of the book can be written on the clamped portion of the card, and so will safeguard against loss and imperfections. This is an advantage not possessed by any of the ordinary card methods, because when cards are torn from the rods they leave no trace, and become lost for ever, leaving it very problematical whether a catalogue is perfect or not.
281.
281. A card catalogue on a somewhat similar principle to the French and Italian forms just described is known as the Duplex Card Catalogue, and was invented in England to enable both sides of the cards to be used, thereby considerably enlarging the capacity of the catalogue, while materially reducing its bulk. It is fitted with falling ends which act as angle-blocks; a travelling angle-block can be adjusted and locked at any point; a locking-rod for threading the cards upon in order to secure them; and xylonite label-holders. The cards are larger than ordinary catalogue cards, and instead of being hinged are simply creased at a short distance above the rod holes. This gives a slight bulge and enables the cards to have the necessary play. The trays are held lengthways in a position parallel to the body, instead of at right angles as in the case of ordinary trays, and the cards or leaves are simply turned over like those of a book.
An extended, illustrated study of the whole of card-cataloguing methodology is Sayers and Stewart’s The Card Catalogue.
Fig. 101.—Duplex Card Catalogue ([Section 281]).