Frederick John Owen Evans

Sir Frederick John Owen Evans KCB, FRS (9 March 1815 – 20 December 1885), was an officer of the Royal Navy. He became a distinguished hydrographer during his career and served as Hydrographer of the Navy.

Biography
Evans, son of John Evans, a master in the Royal Navy, was born on 9 March 1815. He entered the navy as a second-class volunteer in 1828. After serving in HMS Rose (1821) and HMS Winchester (1822) he was transferred in 1833 to HMS Thunder (1829), under Captain Richard Owen, and spent three years in surveying the coasts of Central America, the Demerara River, and the Bahama Banks. Evans subsequently served in the Mediterranean on board HMS Caledonia (1808), the flagship of the Mediterranean Fleet, and then on HMS Asia (1824), HMS Rapid (1829), HMS Rolla (1829), HMS Dido (1836), and HMS Wolverine (1836), passing through the different ranks of the ‘master's’ line, the officers then charged with the duties of navigation. In 1841 Evans was appointed master of HMS Fly (1831), and for the next five years he was employed in surveying the Coral Sea, the Great Barrier Reef of Australia, and Torres Straits. Joseph Jukes, the geologist, was on board the Fly, and wrote an account of the expedition.

After a short spell of duty in the Isle of Man, Evans returned, in 1847, in HMS Acheron (1838), to New Zealand, where he was engaged for four years in surveying the Middle and South Islands. During the Crimean War he served in the Baltic Sea, receiving the special thanks of Sir Charles Napier for his share in piloting the fleet through the Åland Islands.

By this time Evans had become known by his scientific qualifications, and in 1855 he was appointed superintendent of the compass department of the navy. He had at once to consider a difficult problem, the use of the compass in iron ships and armour-clads. It was necessary to deal with the disturbing elements arising from the iron and the magnetisation of the ships. Evans, in co-operation with Archibald Smith, accomplished the task satisfactorily. He contributed seven papers, all dealing with the magnetism of ships, to the Philosophical Transactions of the Royal Society, of which he was elected a fellow in 1862.

Publications
In 1858 Evans prepared a ‘Chart of Curves of Equal Magnetic Declination,’ which was published by the Admiralty. In 1860 he wrote a valuable ‘Report on Compass Deviations in the Royal Navy;’ this treated of the magnetic character of the various iron ships in the navy, and also of the SS Great Eastern. His most important work was the ‘Admiralty Manual for Deviations of the Compass,’ of which Smith and himself were joint editors (1st ed. 1862, 2nd ed. 1863, 3rd ed. 1869). A simple account of the same subject was issued by Evans in 1870 as an ‘Elementary Manual for Deviations of the Compass.’ These have become standard textbooks, having been translated and adopted by all the great maritime nations.

At a later date Evans devoted much attention to terrestrial magnetism. He compiled the magnetical instructions for the observers on board HMS Challenger (1858) in 1872, and delivered a lecture on the ‘Magnetism of the Earth’ to the Royal Geographical Society in 1878. Evans was made a staff-commander in 1863, staff-captain in 1867, and full captain in 1872. In 1865 he was appointed chief naval assistant to the then hydrographer to the admiralty, Captain George Henry Richards, whom he succeeded in 1874. He was made Companion of the Order of the Bath in 1873, and Knight Commander of the Order of the Bath in 1881. He was vice-president of the Royal Geographical Society from 1879 to 1881, and president of the geographical section of the British Association in 1876. In 1881 he contributed a paper to the latter body on ‘Oceanic or Maritime Discovery from 1831 to 1881.’

Later life
After resigning the post of hydrographer in 1884, Evans was appointed one of the British delegates to the International Meridian Conference held at Washington, D.C. in 1885, to fix a prime meridian and universal day.

He died at his residence, 21 Dawson Place, Pembridge Square, London, on 20 December 1885. He had married, on 12 November 1846, Elizabeth Mary, eldest daughter of Captain Charles Hall, R.N., of Plymouth.