The majority of this collection comprises volumes of letters assembled and bound by the 8th Viscount; it is probable that the loose papers of the 5th Viscount were in the process of being assembled on the death of the 8th Viscount in 1907. Also included is an out letter book of 4th Viscount (-/16), which forms part of a series; other volumes in the series are in G145.
A volume of correspondence of the 3rd and 4th Viscounts relating to the Irish estates, 1751-1784, appears first in this list (-/13), followed by two volumes of correspondence of the 4th Viscount, 1767-1836 (-/14 and -/15), and a letter book, 1776-1782 (-/16), of the 4th Viscount, all relating the Irish estates; six volumes of letters from the Rev Charles Brodrick to his brother, the 4th Viscount, 1784-1824, are at -/17 to -/22, and three further volumes of letters of the 4th Viscount relating to the Irish estates, 1774-1882, are at -/23 to -/25. The two final volumes are letters to the 5th Viscount relating to the Irish estates, 1838-1845 (-/25), and letters to the 5th Viscount, chiefly from Augustus Welby Pugin, relating to building works at Peper Harow and Midleton (Co Cork).