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     The British Museum [Library] began to isolate sheet
     maps and atlases from books in the late eighteenth
     century.  By the 1830s this was general practice in the
     Museum, particularly in the increasing number of cases
     of geological memoirs accompanying maps.  Each part of
     such a composite work was liable to take on a library
     life of its own (with a pressmark of its own), and it
     is now the devil's own job to re-establish the 'as
     published' entity.  Often the only way to do it is to
     guess a connection from present-day catalogues, pull
     the items, and compare the superseded and deleted
     pressmarks on each.
 
     Wendy Mann's and Paul Larson's priorities may sound
     fine, but, if the collections they presently manage are
     designed to live through more than one generation of
     curators, how can they be sure that their successors
     will recognise and maintain the connections?  Too often
     one can find that one part of such a connection has
     been discarded, leaving the other as a useless
     dinosaur.
 
     If the total published work is so important, take also
     the book into the Map Collection as 'associated
     documentation'.  If that effectively restricts open
     access to it, that's probably a good curatorial
     decision.
 
     If you have physically to separate map and book, even
     within the map collection, then generate a storage and
     call number for each separated map which embodies the
     unique accession or inventory number of the parent
     book.  In an archive context, for a 'removed' map, we
     take the unique document reference for the parent file,
     prefix it with a letter signifying 'removed maps', and
     suffix it with an ordinal number to signify the first
     (second, third) map removed from that file.  For
     example, W/H/726/1 identifies the first map separated
     from file H/726.  We mark the parent file, at the point
     of removal, with the 'removed map' call number.  A
     patron surveying a map list will see immediately how to
     call the parent file, and a patron examining the file
     will see how to call the removed map, without further
     reference to catalogues.  This also alerts curators
     taking decisions about items in one class of material
     to consider also the associated items elsewhere.  Which
     is where I came in ...
 
     HTH
 
     Dr A S Cook
     Map Archivist
     India Office Records
     The British Library
     197 Blackfriars Road          E-mail: [log in to unmask]
     London SE1 8NG                  Phone: +44 171 412 7828
     United Kingdom                    Fax: +44 171 412 7858