J. M. R. Cameron in his 'Introduction' to The Millendon Memoirs: Geroge Fletcher Moore's Western Australian Diaries and Letters, 1830-1841, explains that '[b]efore leaving home, Moore promised to keep his family and his friends fully informed of all his doings. His first letter, to his father but intended for the whole family, was begun on Friday 12 November 1830 ... and was accompanied by a shipboard journal. Shorter letters to brother Joseph and his sisters followed.'
In order to help Moore's claim for a judicial appointment, his brother Joseph Scott Moore presented the Colonial Office in London with an 'edited and printed collection of letters and journals for the period up to November 1831.' The letters were printed in 1832 as Extracts from Letters Written by a Gentleman Lately Established on the Swan River in Western Australia.
Source : J. M. R. Cameron, 'Introduction' The Millendon Memoirs: Geroge Fletcher Moore's Western Australian Diaries and Letters, 1830-1841 (2006): vii-viii.