He spent two years post graduate study in the Dunboyne Establishment and joined the staff of St Columb's College in 1893.
[1] He was a brilliant scientist, a regular contributor to technical journals on astronomy, light and radio waves and fascinated by the development of the modern wireless system.
He served as College President from 1905 to 1919 when he was appointed Parish Priest of Maghera and, in time, Vicar General of the Diocese.
[2] His appointment was a popular one and, given his experience in education, he made the provision of schools a key part of his pastoral work across his diocese, divided into two sovereign states by Partition of Ireland.
Mooney in Kilrea after a long illness in January 1939 and the Irish Times reported that "10,000 men followed his coffin as it arrived back into his Cathedral city"[5]