Possibly the swiftest route to your roots.
Irish genealogy website directory.
www.from-ireland.net/county/article/Official-Authorities%2C-1834%2C-Co.-Mayo/Mayo
Description:
Representative: John Browne, Esq., (cousin to the Marquess of Sligo), 2 Mansfield street, London and Mount Brown, Co. Mayo, Dominick Browne, Esq., Brookes Club House, London and Castlemacgarret, Co. Mayo.