Mechanical Methods of Displaying Catalogues and Indexes. 59 recent origin. My first intimation of this idea was received nearly ten years ago, when Mr. Mason, then in Glasgow, hinted in a mysterious way about a plan he had of revolutionizing the prevalent methods of displaying catalogues. He took no steps to achieve this result till 1891, when he showed us at Nottingham a somewhat crude specimen of his contrivance. Since then he has greatly improved upon the manner of operat- ing his cylinders, and anyone can see in daily use at St.-Martin- in-the-Fields the revolving drum form of " Panoramic" catalogue, which is, so far as I can ascertain, the very first of its species. I have no idea of its cost, or to what extent, and how, it is used by the public. The idea of a continuous band with entries attached in alphabetical order, occurred to Miss James as it has occurred to Mr. Mason and others, and she prepared, some time ago, the little model which I have here to show you. With rollers in the cellar and attic, there is no reason why this style of appliance should not be made to carry the whole catalogue of a library, and perhaps make a useful lift ! The most recent of these " Panoramic " catalogue holders is the Rudolph Continuous Indexer, invented by the Mr. Rudolph whom I have already mentioned. The illustrations which I have will serve to give some idea of its appearance and method of working. It con- sists of a cabinet standing 3ft. 6in. high, by ift. Sin. wide, and 2ft. 6in. broad, with a plate-glass top, through which the catalogue can be examined. Inside there are 600 slats, which revolve over two hexagonal drums in a continuous chain, and these are looped up for storage purposes in hanging folds by the very ingenious mechanical means provided. Each slat has metal grooves at the edges, under which cardboard slips bearing entries are arranged as desired. The slats are detach- able, so that a fresh one can be inserted anywhere in the chain when congestion occurs. The machine is operated by a crank, and I can bear testimony to the claim that it works rapidly, easily, and without noise. Each slat will hold 136 single line entries, and the total capacity of a complete cabinet may be put at 40,800 double line entries. It has, therefore, some advantage as regards storage capacity, adjustability, and ease of working. On the other hand, I regard it as a fatal defect, as far as library use is concerned, that one con- suitor can monopolize the whole 40,800 entries. Even when broken up into smaller cabinets the objection would be but little remedied, and the additional expense might make any advantage
