John George Hatchard, railway engineer and amateur astronomer, was educated at the University College School, London, and then served an apprenticeship at the London and North-Western Railway Works at Crewe, England. For several years he worked in the drawing office there. He superintended special experimental work and testing of iron, steel, alloys and oils. Meanwhile he conducted technical classes at the local Mechanics Institute, a voluntary organisation for promoting adult education of the working classes. In August 1895 he married Bernice Cooke, with whom he had three children.
Hatchard came to South Africa shortly after the Anglo-Boer War (1899-1902) and was employed at the Pretoria works of the Central South African Railways (CSAR) in March 1903. Because of his experience in technical education he was transferred to Bloemfontein in January 1904 to initiate technical classes there for the CSAR. He became chairman and managing director of the Orange River Colony Civil Service Supply Association, and served on the committee of the Railway Institute, Bloemfontein. After the amalgamation of the CSAR with the Cape Government Railways and Natal Government Railways to form the South African Railways in 1912, he became an instructor to locomotive staff in the locomotive drawing office at Bloemfontein. He joined the South African Institute of Engineers in September 1908 and in January 1916, still in Bloemfontein, became a member of the (British) Institution of Mechanical Engineers.
Hatchard's principal hobby was astronomy, with a particular interest in stellar spectroscopy. He was a foundation member of the British Astronomical Association and in 1902 was elected a Fellow of the Royal Astronomical Society. He was also interested in ornithology, for in 1904 he became a foundation member of the South African Ornithologists' Union, serving on its council in 1906 as representative for the Orange River Colony. He joined the South African Association for the Advancement of Science in 1905 and was still a member in 1918. During the last ten years of his life he was involved in several law suits.