Seventeenth-century letters and papers, 1595-1699 and 1871 of the two branches of the Parsons family, the Parsonses of Bellamont, Co. Dublin, Viscounts Rosse, and the Parsonses of Parsonstown, alias Birr, King's County.
Eighteenth-century letters and papers, 1705-1887, of both branches of the Parsons family, but almost all of them deriving from the Parsonses of Parsonstown - excluding the papers of Sir Laurence Parsons, 5th Baronet, later 2nd Earle of Rosse, which constitute Sections C-F.
Letters and papers, 1765-c. 1820 and 1855, of Sir Laurence Parsons, 5th Baronet, who succeeded in 1807 as 2nd Earl of Rosse (of the second creation, the earldom in the elder branch of the Parsons family having died out in 1764), reflecting Parsons's youthful intimacy with Henry Flood, and consisting of correspondence and speech-notes of Flood, letters to Parsons from and about Flood, and drafts for biographical and historical writings by Parsons on Flood.
Letters, 1791-1834, to Sir Laurence Parsons, 2nd Earl of Rosse, from his principal correspondents, on all manner of personal, political and business matters, arranged chronologically according to the date of the first item in each sub-section.
Letters and papers, 1791-1841, of Sir Laurence Parsons, 2nd Earl of Rosse, including (during his lifetime) papers of his first and second sons, Lord Oxmantown and the Hon. John Clere Parsons, arranged by topic, and chronologically according to the date of the first item in each sub-section.
Notesand drafts, [1765?] and c. 1775-c. 1840, by Sir Laurence Parsons, 2nd Earl of Rosse, in connection with various subjects: parliamentary precedents, his speeches at College Green and Westminster, his poems, the history and genealogy of the Parsons family, and his miscellaneous writings (published or unpublished), with the exception of those on the subject of Henry Flood [for which, see Section C].
Papers (almost exclusively estate and financial), c. 1540-2001, of the Wilmer Field family of Heaton Hall, Bradford, Yorkshire, whose co-heiress, Mary Field, married in 1836 Lord Oxmantown, later 3rd Earl of Rosse, including a few papers about the Heaton estate after its merger with the Rosse estates in Ireland.
Papers of the Hawke family, Lords Hawke, 1682-1824 and 1832-2006, present among the Rosse Papers because of the marriage in 1870 of the Hon. Frances Cassandra Hawke, heiress of her father, the 4th Lord Hawke, to the 4th Earl of Rosse; including some naval, administrative and political papers of Admiral Sir Edward Hawke, K.B., 1st Lord Hawke, victor of the Battle of Quiberon Bay in 1759, and First Lord of the Admiralty, 1766-71.
Correspondence and other papers of the 3rd Earl of Rosse, 1829, 1832 and 1840-2003, as President of the Royal Society, Chancellor of Trinity College, Dublin, Lieutenant of King's County, leading landowner there, and general public figure, excluding where physically possible correspondence of the sort concentrated in Section K.
Correspondence of the 3rd and 4th Earls of Rosse with fellow-astronomers or about the Birr and other observatories, including correspondence of the 5th and 6th Earls about the Birr Observatory, 1840-1909, 1913-14, 1938 and 1964-84.