books is the catalogue of maps and plans, reduced, under Professor Douglas's direction, from upwards of three hundred of MS. to two volumes of print as issued to the public, or fourteen as laid down for use in the Reading Room. The four hundred and fifty MS. volumes of the catalogue of music, it is hoped, are on the eve of undergoing similar treatment. Apart from the errors which must inevitably creep into so vast a work, dealing with such a variety of languages and literatures, and now in progress for more than fifty years, a considerable amount of imperfection is evidently inseparable from the very nature of the undertaking. It does not and cannot represent the condition of the library at any given moment. The volumes containing A, for example, will comprise the books under that letter possessed by the Museum in 1882 or 1883; but T, which for reasons which we have no space to explain, will probably be the last letter to be printed, will represent the condition of the library, as regards that letter, about the year 1900. During the whole progress of the catalogue an incessant shower of new titles representing the new books continually being acquired, will have been descending at the rate of some 40,000 a year. Those belonging to letters not yet at press will have been taken up and absorbed by the catalogue in its progress; those belonging to the letters already in type must fall into a supplement. The article Thackeray, therefore, will be more complete than Dickens, and Thucydides than Herodotus. As concerns the student at the Museum, this is of no importance; the additions being regularly incorporated in the Reading Room catalogue in the manner above described. The catalogue as issued to subscribers, however, is necessarily imperfect and irregular. Supposing, for example, that Lord Tennyson and Mr. Browning were to simultaneously publish translations of Homer when the printing of the catalogue had reached the article Jones, Lord Tennyson's version would appear under Tennyson, but not under Homer, and Mr. Browning's version would not appear at all. There is but one way of obtaining a perfect index to the condition of the national library at a given time: the catalogue must be reprinted along with the numerous accessions which have been accumulating while the first edition has been going through the press—a national undertaking which will commend itself to men of letters more readily than to ministers of finance. Should, however, the completion of the catalogue nearly coincide with the commencement of the twentieth century, it may be hoped that this will be one of the many ways in which, if the new century does not, like its predecessors, find the nation traversing a crisis, the epoch will assuredly be commemorated. It would remain to provide for the regular reprinting of the catalogue with its accessions at intervals, say of a quarter of a century. England would then possess a complete