James Rennell - Rennell's Achievements

Rennell's Achievements

His most valuable works include the Bengal Atlas (1779), the first approximately correct map of India (1783), the Geographical System of Herodotus (1800), the Comparative Geography of Western Asia (1831), and important studies on the geography of northern Africa—apparent in introductions to the Travels of Mungo Park and Hornemann. He however forged the geographic data of Park by introducing a mountain range, the Mountains of Kong, supposedly located in the western part of Africa. The fake was intended to support his own theory about the course of the Niger River. The Mountains of Kong remained present in maps until the early 20th century. He also contributed papers to Archaeologia on the site of Babylon, the island of St Paul's shipwreck, and the landing-place of Caesar in Britain.

Beside his geographical and historical works James Rennell is known today for his hydrographical works about the currents in the Atlantic and Indian oceans. He started his research on these topics, when he was travelling by a sailing ship with his family from India to Britain after his retirement in 1777. During the extraordinary long voyage around the Cape of Good Hope he mapped "the banks and currents at the Lagullas" and published in 1778 the work about what is today called the Agulhas Current. This was one of the first contributions to the science of Oceanography. He was the first to explain the causes of the occasional northern current found to the south of the Scilly Isles, which has since become known as Rennell's Current.

While in India he had married (1772) Jane Thackeray, daughter of Dr. Thomas Thackeray, headmaster of Harrow, and a great-aunt of the novelist William Makepeace Thackeray. His second son, William, was in the Bengal civil service, and died in 1819, leaving no children; the eldest, Thomas, was unmarried, and survived until 1846. His talented daughter Jane was married, in 1809, to Admiral Sir John Tremayne Rodd, KCB. Lady Rodd devoted several years to the labour of publishing her father's current charts and revising new editions of his principal works. She died in December 1863.

After the death of his wife in 1810 he returned to the oceanographic topics. His numerous naval friends gave him a mass of data from their logs, which he assimilated to a chart of all currents in the Atlantic ocean. During his last years he wrote his final and most important work Currents of the Atlantic Ocean, published posthumously by his daughter Jane in 1832, which was not significantly overtaken until 1936.

He was elected a fellow of the Royal Society in 1781; and he received the Copley Medal of the Royal Society in 1791, and the gold medal of the Royal Society of Literature in 1825.

He died on 29 March 1830. He was interred in the nave of Westminster Abbey, and there is a tablet to his memory, with a bust, near the western door. The year of his death saw the foundation of the Royal Geographical Society.

Rennell was "of middle height, well proportioned, with a grave yet sweet expression of countenance. He was diffident and unassuming, but ever ready to impart information. His conversation was interesting, and he had a remarkable flow of spirits. In all his discussions he was candid and ingenuous".