Born at Norwich, the son of James Mann, and was educated at University College, London. He practised for some years in Norwich and Buxton, but weak health led him to give up medicine. He published in 1845 *The Planetary and Stellar Universe*, which was followed by a long series of text-books on astronomy, chemistry, physiology, and health, designed to popularize science. He graduated MD at St Andrews in 1854, and in 1857 he left England for Natal on the invitation of Bishop Colenso, and lived in the Colony for the next nine years. He was appointed to the newly established office of Superintendent of Education two years after his arrival, and established the system of primary education which long remained in force. He also made a careful and valuable record of the meteorology of Natal. He returned to London in 1866 with a special appointment as Emigration Officer for the Colony, and became President of the Meteorological Society, a post he held for three years. He was also, for the same length of time, one of the Board of Visitors of the Royal Institution. From 1874-1886 he was Secretary of the African and the Foreign and Colonial sections of the Royal Society of Arts. He took an active part in the organization of the scientific apparatus at the South Kensington Exhibition in 1876, having superintended the collection and dispatch of the Natal collections to the Great Exhibition of 1862. He also compiled the catalogue of the Natal Court at the Colonial and Indian Exhibition of 1886. He died at Wandsworth on August 8th, 1886, and was buried at Kensal Green Cemetery.