There are many disadvantages in this plan of putting press-marks to references, but it is adopted at the British Museum, and it certainly is annoying to have to run from one end of a many-volumed catalogue to another.
In Mr. Nichols's Handbook for Readers it is said (p. 42) that "a work is never entered at full length more than once and it is only from the main entry that the book-ticket must be made out." But if the press-marks are added to the references, one would imagine that they are intended to be used, and it is scarcely to be expected that any one will take the trouble to refer to another place when he has sufficient information under his eyes.
Catalogue work is different from index work, where the entries may be duplicated without inconvenience; but in the case of books, if all the references have press-marks, there is considerable danger of confusion whenever the position of a book is changed. The main entries will be corrected, but some of the references will almost certainly be overlooked. If the books are never moved, there is no great harm in putting press-marks to the references.
It must, I think, be conceded that when the references are so long as they often are in the British Museum Catalogue, and as seems to be contemplated by Mr. Cutter's remark quoted above, they are really duplicate or subsidiary entries rather than references.
There is no real necessity to copy any part of the titles in the great majority of references. Take, for instance, the following two modes of referring from the subject of a biography to the authors:—
Shakespeare:
| —— and his Contemporaries. Nares. 1822. 4to. | 27342 |
| —— and his Times. Drake. 1817. 2 vols. 4to. | 7212 |
| —— Biography. De Quincey. vol. xv. 8vo. | 1808 |
| —— —— Knight. 1842. 8vo. | 13296 |
| —— Biographical Memoir. 1825. 8vo. | 21294 |
| —— History of. Fullom. 1864. 8vo. | 29492 |
| —— Illustrations of his Life. Halliwell. 1874. 4to. | 47851 |
| —— Life. Chalmers. German trans. Leipzig. 8vo. | 35270 |
| —— —— Halliwell. 1848. 8vo. | 10430 |
| —— —— Skottowe. 1824. 2 vols. 8vo. | 21673 |
These entries are taken from a large heading, and do not come together as they do here. By following the wording of the title in this way you do not get a true index. For instance, under this same main heading of Shakespeare we have in different parts of the sub-alphabet:—
| Illustrated. Lennox. 1753-4. 3 vols. 12mo. | 13861 |
| Life. Skottowe. 1824. 2 vols. 8vo. | 21673 |
| Plots. Simrock. 1850. 8vo. | 21617 |