⁶ O'Donovan, John, Thomas O'Connor, P. (Patrick) O'Keeffe, and Michael Herity. Ordnance Survey Letters Letters Containing Information Relative to the Antiquities of the County of Kildare Collected during the Progress of the Ordnance Survey in 1837, 1838, and 1839. Dublin: Four Masters, 2002. 180-81 (orig. ms.).