It is obvious that a work of this kind must be of the greatest utility, and as the _English Catalogue_ is merely a continuation of the _London Catalogue_ and the _British Catalogue_, the former of which commenced so far back as the year 1811, it will be seen that a comprehensive view can be taken of the whole range of English literature from that date to the present. The _Catalogue_ has not, however, always been so carefully prepared as it is now, and consequently in the earlier days many publications were omitted. When this is the case Lowndes and Watt will be found of material assistance, the latter especially. A complete set of these catalogues, unfortunately, is very difficult to obtain, and as the earlier ones are not indispensable, it may be perhaps advisable to forego them and to commence in 1814. The volumes to be acquired therefore would be _London Catalogue_, 1816-51; _English Catalogue_, 1835-63, 1863-71, 1872-80, 1881-89; with the accompanying subject indexes to the _London Catalogue_, 1814-46; and to the _English Catalogue_, 1835-55, 1856-75, 1874 (_sic_)-80. It will be noticed that the dates sometimes overlap each over, but this is an advantage rather than a drawback. Among the other books frequently consulted by both dealers and amateurs are Mr. Swan Sonnenschein's _The Best Books_; the _Reference Catalogue of Current Literature_, and Halkett & Laing's _Dictionary of Anonymous and Pseudonymous Literature of Great Britain_, in 4 vols. These are mentioned together because they are essentially subject indexes and the best of their kind. Sonnenschein's _The Best Books_, already in a second and vastly improved edition, is a comparatively recent publication, in which, under subjects arranged systematically, are placed the best current books, whether ancient or modern, on each subject, with the prices, sizes, publisher's name and dates of the first and last editions of each. There are about 50,000 works included, and they together give a very good idea of all the material in the various departments of research which the specialist is likely to have occasion to read or refer to. Old books are included where they are of actual present-day value to the student. The selection is not, of course, entirely made by the author, as it is impossible for him to have read a hundredth part of the books recommended; most probably the list has been compiled from the works of specialists, the various encyclopaedias, and so forth; but however this may be, it is a very useful one in the hands of a person capable of discrimination (towards which the numerous critical and bibliographical notes and the system of asterisks are a great help), especially if he live near one or other of the large libraries now springing up in different parts of the country.