The main focus of Braikenridge's activity was his copy of William Barrett's History and Antiquities of the City of Bristol. It was common then for possessors of such histories to extra-illustrate or "grangerise" them, that is, to collect additional illustrations to be interleaved with the text. The items that Braikenridge collected for this purpose were eventually sufficient to fill 36 portfolios. They included a wide variety of printed, engraved and written materials and assorted ephemera. Braikenridge's copy of Barrett's book together with this interleaved collection is in the Bristol Central Library.
