Wooden boards previously used to group the letters thematically. The divides are 'carronades, introduction of 1779 - 1782, Mr Gascoignes letters experiments; fleet operations afloat 1794-1795; convicts; appendix; West Indies miscellaneous papers but all connected with Sir Charles' services in that country 1757-1760, also coast of Africa ships on that station; Chest at Chatham; finance of the navy; coppering the navy; papers on rigging and the outfit of ships after launching, mast making; foreign navies also the arsenal of Toulon; land revenue and crown lands.'