[10] He served most of his civil service career in Federated Malay States and Straits Settlements.
[9] In November 1919, he was appointed as the Collector of Land Revenue (Kuala Lumpur) and Registrar of Titles (Selangor).
[9] In 1924, he was the Acting Under-Secretary when Sir Frederick James became Governor of the Windward Islands.
[9] In 1930, Hemmant was appointed Chief Secretary to the Government of Nigeria to replace Sir Frank Baddeley who was retiring.
[6][7] He married Gladys Evelyn, younger daughter of Mr and Mrs E. A. Knight of Oaklands, St Leonards on 11 June 1925 in London.