Charles F. Close, surveyor and geographer, attended the Royal Military Academy at Woolwich from 1882. He was commissioned in the Royal Engineers in 1884, and joined the School of Military Engineering at Chatham. From 1889 to 1893 he headed the great trigonometrical survey of India. In 1895 he was sent to West Africa as part of an Anglo-German party to survey the boundary between the Niger Coast Protectorate and the German Cameroons. On his return to England he was appointed to the Ordnance Survey. In 1898 he was British Commissioner for the delimitation of the frontiers between British Central Africa and Northern Rhodesia (now Zambia) on the one hand and German East Africa. During this work he collaborated with Dr David Gill*, H.M. Astronomer at the Cape, to determine the necessary longitudes, and published a "Note on the heights of Lakes Nyassa and Tanganyika above sea level" in the Geographical Journal (1899). He was honoured as a Companion of the Order of St Michael and St George (CMG) in 1899.
Shortly after the outbreak of the Anglo-Boer War (1899-1902) Close was put in charge of the first military survey unit sent to South Africa by the British War Office, arriving in February 1900. The unit formed part of the Field Intelligence Division and consisted of eight surveyors, who compiled and printed various military maps. At the end of the war, in 1902, Captain Close was appointed assistant superintendent of the geodetic survey of the Transvaal and Orange River Colonies, under Colonel W. Morris*. However, he was invalidated home and later that year became chief instuctor in surveying at Chatham, a post he held to 1905. In March 1904, then a major, he returned briefly to South Africa to represent the War Office at a geodetic congress in Cape Town at which the further geodetic and topographic survey of southern Africa was planned.
In 1905 Close and Captain H.J.L. Winterbotham* produced their Text book of topographical and geographical surveying, which became a standard work (3rd ed. 1925). Also in 1905, Close was appointed head of the Geographical Section of the General Staff (GSGS) at the War Office. That same year he created a new advisory body, the Colonial Survey Committee, which consisted of members from GSGS, the Ordnance Survey and the Colonial Office. The committee's early annual reports dealt mainly with African survey issues. Close appreciated both the importance of disseminating practical information and the value of scientific inquiry for its own sake. He believed in the fundamental importance of accurate mapping of the colonies for their future economic and scientific development.
In 1911 he became director-general of the Ordnance Survey where, among others, he directed a second geodetic levelling of the United Kingdom. He retired in 1922. Among his publications were Notes on the geodesy of the British Isles (1914), The early years of the Ordnance Survey (1926), and some papers on map projections. In 1933 he published a paper, "A fifty year retrospect", in the Empire Survey Review. He served on the council of the Royal Geographical Society from 1904 to 1940, and was its president from 1927 to 1930. He was elected a Fellow of the Royal Society in 1919, was awarded an honorary Doctor of Science degree by the University of Cambridge in 1928, and served as president of the International Geographical Union from 1934 to 1938. In the latter year he changed his surname to Arden-Close. Under this name he wrote a paper on "The state of the surveys in British Africa in 1905-1906", which was published in the Empire Survey Journal in 1950.
Close ended his career with the rank of colonel. He was appointed Companion of the Order of the Bath (CB) in 1916 and Knight Commander of the Order of the British Empire (KBE) in 1918.