William Mawhood's diary is contained in forty-nine note-books (6" x 4") with a total of just over four thousand pages and probably half a million words. The first entry is dated 14th July 1764 and the last 18th October 1790. He began using these note-books for business memoranda, but gradually he formed the habit of adding
notes of a personal or family interest, so that, in the later volumes, business affairs take a subordinate place. William Mawhood also copied into his note-books drafts of letters concerning family matters.