Following the death of Edward O'Reilly in August 1830, he was recruited to the Topographical Department of the first Ordnance Survey of Ireland under George Petrie in October 1830. Apart from a brief period in 1833, he worked steadily for the Survey on place-name researches until 1842, unearthing and preserving many manuscripts.
After Edward O'Reilly's passing in August 1830, he was recruited for the Topographical Department of Ireland's first Ordnance Survey under George Petrie in October 1830. Except for a brief period in 1833, he diligently worked on place-name researches until 1842, uncovering and preserving many manuscripts.