James Grantham of the Royal Engineers was responsible for laying out Aldershot military camp in Britain and served in the East Indies. He was posted to Natal Colony in 1856, arriving with his wife Ellen and three children. One of his first tasks was a survey of Durban harbour in 1857. His report on this work is dated 3 February 1858. That year, with the rank of Captain, he was based at Fort Napier, Pietermaritzburg. In April that year he sent his family back to Britain and soon afterwards was involved in a scandal involving a married woman, Emma Parish, with whom he eventually had four children. However, the affair did not affect his professional status.
Grantham was next employed by the British War Office to survey the borders of the colony and the Drakensberg passes. Following this survey and based on information in the office of the Surveyor-General of Natal (P.C. Sutherland*) he compiled a Map of the Colony of Natal (scale 4 miles to the inch, i.e., 1:253 440) which was more detailed than the earlier maps by J.A. Watts* and Dr R. Mann*. Grantham's map was printed by the British War Office in 1863. On this neat and comprehensive wall map, consisting of three sheets, he indicated topographical detail of hilly terrain by means of hill-shading. It also contained a number of spot heights and indicated for the first time the position of the border between Natal and Basutoland (now Lesotho). A copy of the map was later housed in the Durban City Library.
Grantham is mentioned incidentally by Spencer (1981-) as the owner of a land grant in or near the Karkloof Valley, Natal. He later designed Fort Buckingham in Natal and also worked in Canada, Mauritius and Australia. In 1873 he retired from the army and settled in Natal on a farm in the Rietvlei area. Later he went to Australia again where he worked on a harbour survey, returning to Natal in 1881. He continued doing survey work until his death in 1896.