Mechanical Methods of Displaying Catalogues and Indexes. 47 points deserving notice in connection with these variations of a single idea. To me, it seems almost impossible to resist the conclusion that, for a large library, a catalogue on the distribu- tive plan of the British Museum is more economical as regards labour and cost ; more serviceable to the consultors, especially if arranged in separate author and subject alphabets ; and more likely to remain longer uncongested, than the plan of concentra- tion adopted at Glasgow. It is only once in a while that several persons wish to consult the same division of a sectional catalogue, and even then, having to wait their turn is just the same as having to wait for a chance of seeing a complete catalogue when all are in use. Apart from this, and the fact that a divided " Page " catalogue will serve many more persons at once than a dozen or more complete catalogues of a similar nature, my objections to guard-books of any kind greatly out-weigh all that I can say in their favour. There is first, their enormous comparative cost ; second, the continuous and unhealthy labour of mounting them up to date ; third, their unfailing tendency to become congested at all times and particularly at places where special precautions are adopted as a certain preventive ; and fourth, the ease and rapidity with which they become soiled and destroyed in a busy library ; not to speak of the continual peeling away of entries. This brings me to the guard-book, or "Page" variety of catalogue, which possesses means for the insertion or abstrac- tion of leaves when required. There are numerous methods of attaining this end, and in the specifications filed at the Patent Office, there are probably a hundred different kinds of binders, files, and albums, in which means for adding or withdrawing leaves are provided by the use of springs, wires, gut or cords, and screws. The earliest of these is doubtless the album laced together with cords, of which I have here an example. Mr. Cowell, of Liverpool, showed a book something like this at the London conference in 1877, and at Liverpool in 1883, but the method of adjustable binding is really old, and has been used in Holland and Germany, probably also in Britain, for many years. Still, it has recently been patented, though not possessing one scrap of novelty. Mr. Cowell's 1877 album provided for the insertion of single slips, a fact worth notice at this point. Another somewhat similar book is used in France, and no doubt some of you who visited Paris in 1892 will recognise the style of catalogue as that used in the Bibliotheque National and else- where. In principle it differs from the cord binders in several
