Letter listing for 1820–1829
- Caroline Lucretia Herschel to Sir John Frederick William Herschel, 1st baronet of Slough, 8 May 1827
- Caroline Lucretia Herschel to Mary Herschel [née Baldwin], 10 July 1827
- Clara Mary Jane Clairmont to Mary Wollstonecraft Shelley [née Godwin], 23 July 1827
- Caroline Lucretia Herschel to Sir John Frederick William Herschel, 1st baronet of Slough, 15 August 1827
- Caroline Lucretia Herschel to Sir John Frederick William Herschel, 1st baronet of Slough, 25 September 1827
- Charles William Wentworth Fitzwilliam, 3rd Earl Fitzwilliam to Reverend William Venables Vernon Harcourt, 16 November 1827
- Reverend William Venables Vernon Harcourt to Charles William Wentworth Fitzwilliam, 3rd Earl Fitzwilliam, before 16 November 1827
- Caroline Lucretia Herschel to Sir John Frederick William Herschel, 1st baronet of Slough, 22 December 1827
- Sir Roderick Impey Murchison to John Phillips, before 21 January 1828
- John Phillips to Sir Roderick Impey Murchison, 21 January 1828
- Awards address by Sir James South for Royal Astronomical Society, 8 February 1828
- Clara Mary Jane Clairmont to Jane Johnson [née Cleveland], 14 March 1828
- Sir John Frederick William Herschel, 1st baronet of Slough to Caroline Lucretia Herschel, 5 May 1828
- Caroline Lucretia Herschel to Mary Herschel [née Baldwin], 9 May 1828
- Sir John Frederick William Herschel, 1st baronet of Slough to Caroline Lucretia Herschel, 28 May 1828