James Rennell

Beside his geographical and historical works, James Rennell is known today for his hydrographical works on 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 prolonged voyage around the Cape of Good Hope^[12] he mapped "the banks and currents at the Lagullas" and published in 1778 the work on 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 Isles of Scilly, which has since been called as Rennell's Current.^[3]

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 into a chart of all currents in the Atlantic Ocean. During his last years, he wrote his last work Currents of the Atlantic Ocean, published posthumously by his daughter Jane in 1832.^[13]

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.^[3] James Rennell has been called the Father of Indian Geography,^[14] and for his pioneering work on oceanography as the Father of Oceanography.^[15]

In later life Rennell suffered from gout and in 1829 he fell from a chair and broke his thigh. He died on 29 March 1830 at his home on Suffolk Street. He was interred in the nave of Westminster Abbey, and there is a tablet to his memory, with a bronze bust by Ludwig Hagbold, near the western door.^[16] The year of his death saw the foundation of the Royal Geographical Society.^[3] His collection of books were gifted by his heirs to the Royal Geographical Society.^[17]

In 1851, botanist

James Rennell is credited with the original mapping of the Mountains of Kong, supposedly located in the western part of Africa, based on information supplied by explorer Mungo Park. This range was intended to support his own theory on the course of the Niger River, and eventually led to a major impact on the mapping industry to include the mountains. In 1802, Aaron Arrowsmith released a map that included the Mountains of Kong as a main physical geographic feature of western Africa,^[19] which encouraged other publishers to update their maps to match.

Debate surrounding the existence of the mountain range occurred frequently, however, it was French officer and explorer Louis-Gustave Binger officially reported that the Mountains of Kong did not exist during an expedition in 1887-1888.^[19] It was not long after this that the Mountains of Kong were dropped from most map publications.

While the Mountains of Kong have been disproven, it has remained periodically on maps in until the early 20th century.^[19]

Personal life

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".^[3] Rennell was however irrational in proposing that the Niger ended in a lake without reaching the sea. He was also strongly opposed to the methods of William Lambton in his proposed trigonometrical survey. His opposition had to be neutralized by Sir Nevil Maskelyne before Lambton's plan was approved.^[20]

While at Dacca, Rennell became a close friend of John Cartier. It was in Cartier's home that he met Jane Thackeray (d. 1810), daughter of Dr Thomas Thackeray, headmaster of Harrow, and a great-aunt of the novelist William Makepeace Thackeray and he married her in 1772. Their older son Thomas (born 1779) died unmarried in 1846, while the second son William (born 1781) worked in the Bengal civil service and died in 1819 without leaving any children. One daughter named Jane (born 1773) died young and was buried in Dhaka, whilst another daughter, also Jane, born in 1777 on St Helena where he had stopped on his way to England married Admiral Sir John Tremayne Rodd, KCB in 1809. Lady Rodd devoted several years publishing her father's current charts and revising new editions of his principal works. She died in December 1863.^[3][2]

References