He was a specialist in the Victorian Mines Department, undertook research in Cambridge and was director of the Museum of Victoria from 1931 to 1944.
[1] Mahony was one of the first specialists with a higher degree to be appointed to the Victorian Mines Department briefly replacing as petrologist (Sir) Albert Kitson when he resigned.
[1] Mahony enlisted as second lieutenant in the Royal Artillery in Britain in 1915 and was promoted to the rank of acting captain in August 1917.
A. Kershaw, where he encouraged research and scholarship among the existing staff, despite the funding cuts imposed by the Government during the Depression.
He also re-established the Memoirs of the National Museum of Victoria He also started the practice of engaging honorary staff to assist in the museum's work and promoted its public image through a new display program on modern American methods that had been demonstrated in Australia in 1937, for which he raised funds from private individuals and through a grant from the Carnegie Corporation; he also made a personal benefaction.