Another need of paramount importance to all engaged in the pursuit of knowledge is that the contents of the numerous periodicals produced throughout the world, registering advances in all branches of science and research, should be abstracted and indexed, so that the material should be rendered accessible or at any rate its existence fully known.[31] Mention has already been made of the Subject-Index to Periodicals, in which some hundred and fifty periodicals are systematically indexed. This important undertaking was initiated some years ago by Mr. E. Wyndham Hulme, late librarian to H.M. Patent Office; it has been carried on successively under the auspices of the “Athenæum” and of the Library Association. It is at present a heavy burden upon a few devoted shoulders, although a very large part of the labour is performed by volunteers; yet its scheme is susceptible of indefinite expansion, if all the requirements of scientific and technical workers are to be, even approximately, met. It is eminently a task pertaining to the library, the university and college library, the special library, and the research department of all types. Were there a central library department in existence, it would undertake this as part of its ordinary routine. It would also undertake the collateral task of preparing and publishing a union catalogue of the long sets of periodicals of all kinds to which the Subject-Index gives the references, and it would indicate where these sets are to be found. Besides the indexing, it would perhaps carry out the further but hardly less valuable work of drawing up and issuing systematic digests of important new knowledge contained in the learned periodicals. It has been recently proposed that the British Museum should carry out this necessary piece of national work, the cost of which, sales being allowed for, would not be excessive.[32] Such results, however, invaluable as they would be to the whole nation, through the services rendered to several classes of workers, would be only a by-product of the centralizing and systematizing process, the immediate object of which would be the betterment of our libraries. Let us return then from this digression. In the middle of last century and towards its end, Edward Edwards and then his biographer, Thomas Greenwood, both stated their conviction that central control was necessary, and that one of its most useful instruments would be systematic inspection. Greenwood quotes the following from Edwards:-- “If every Library in this country on which the public has any fair claim, could be brought distinctly under public view, by a precise and periodical statement, comprising at least three particulars: (1) what it _is_; (2) what it _has_; and (3) what it _does_; a long train of improvements would inevitably follow. But the systematic inspection of Public Libraries to be effective must be national.”[33] He goes on: