The collections of modern manuscripts at Trinity fall into three main groups, as described below. The group to which each collection belongs is determined by the date when it was received and its size, not the nature of its contents. A few collections do not belong to one of the main groups. A complete list of the collections will be found here.
Until the 20th century all the Library’s manuscripts were kept in three locked classes, or bays, in the historic Wren Library. These classes are marked B, O, and R, and the references of the manuscripts now or formerly kept in them begin with the same letters. Most of these items are manuscript books or loose papers bound as volumes. The medieval manuscripts are described in the online James Catalogue and the present catalogue contains descriptions of many of the rest, but they are still being added.
By the middle of the 20th century it had become inconvenient to continue adding manuscripts to the classes in the Wren Library, and a new category of Additional Manuscripts was created. At first, new accessions were distributed among four series—Add. MS a, Add. MS b, Add. MS c, and Add. MS d—according to size. The first of these series is the only one still in use, and the distinction of size has been abandoned. Most of the items in these series are loose papers in boxes. They include a number of fairly large archives of personal papers which we would now class separately as named collections (see below). Some of these larger archives are together in a continuous sequence, but others are scattered in several places.
After the Additional Manuscripts series had been in use for some years it was decided that large collections should be catalogued separately. Each named collection has its own prefix, usually consisting of four letters: e.g. the papers of Ludwig Wittgenstein have the prefix WITT. There are about eighty of these collections. Some ‘artificial’ named collections have been created in the present catalogue to bring together descriptions of papers which belong together but which are scattered in different places: e.g. those of William Whewell (WHWL*). The prefixes of artificial collections end with an asterisk. Some named collections are not personal or family archives but collections of manuscripts relating to a particular subject. The prefixes of these collections consist of full names, thus: Crewe MS (various subjects), Cullum MS (autographs), Rothschild MS (18th century literature), Sraffa MS (history of economics).
There are a few collections which do not fall into one of the above categories, but the only one presently described in this catalogue is Manuscripts in Printed Books (MSPB).