# Dictionary of National Biography, 1912 supplement/Hennessey, John Bobanau Nickerlieu

John Baboneau Nickterlien Hennessey in the ODNB.
​HENNESSEY, JOHN BOBANAU NICKERLIEU (1829–1910), deputy surveyor-general of India, born at Fatehpur, Northern India, on 1 Aug. 1829, was son of Michael Henry Hennessey by a native mother. After being educated locally, he was admitted to the junior branch of the great trigonometrical survey on 14 April 1844. For some years he worked in the marshy jungle tracts of Bengal and the north-west provinces bordering the Nepal Terai. Of the party of 140 officers and assistants which he joined, forty were carried off by fever in a few days, and he was often incapacitated by illness. But his zeal and thoroughness attracted notice, and, transferred to the Punjab in 1850, he fixed the longitudinal position of Lahore, Amritsar, Wazirabad, and other places.
Attached to the superintendent's field office in 1851, he helped the astronomical assistant to collate the various computations of latitude observations and in other work. In Oct. 1853 he was placed in charge of the branch computing office, and in the following year assisted the surveyor-general at the Chach base line. Promoted to the senior branch on 25 April 1854, he was employed at headquarters (Dehra Dun) in reducing the measurements of the Chach base line, and preparing (in ​triplicate manuscript) a general report on the north-east longitudinal series. During the Mutiny he was at Mussoorio, a hill station ten miles beyond Dehra Dun. For nearly five months he was under arms and on harassing duty.
After service with the base line at Vizagapatam, in the south, he took two years' leave to England in March 1863. Entering Jesus College, Cambridge, on 31 Oct. as a fellow commoner, he pursued mathematical studies with great aptitude under professors Adams, Challis, and Walton. With the sanction of the secretary of state he learned the new process of photo-zincography at the ordnance survey offices, Southampton, and returning to duty in India (April 1865) took out an extensive apparatus with which he established the process at survey headquarters. By this means the rapid reproduction of maps and survey sheets became possible, and the great cost and delay of sending orders to England were avoided.
Hennessey, appointed to the charge of the amalgamated computing office and calculating branch, made (1866) the comparisons of standards and determined the 10 feet standard bar of the trigonometrical survey. He also took in hand the vast accumulations of material provided by the labours of William Lambton [q. v.]. Sir George Everest [q. v.], and Sir Andrew Scott Waugh [q. v.], and with the help of a large staff reduced them to order.
Hennessey assisted his chief, General James Thomas Walker [q. v.], in the editorship of the monumental 'Account of the Operations of the Great Trigonometrical Survey of India,' of which the first volume was issued in 1870. He was a large contributor to some of the volumes, fourteen of which were issued during his tenure of office. He also wrote the report on 'Explorations in Great Tibet and Mongolia, made by A——k in 1879–82' (Dehra Dun, 1884). He was designated deputy superintendent of the trigonometrical survey in Sept. 1869, officiated as its superintendent in 1874, and after the three branches of survey operations had been amalgamated under the title of the Survey of India, he was appointed (Feb. 1883) deputy surveyor-general.
On 9 Dec. 1874, with the equatorial of the Royal Society, he observed from Mussoorie (6765 ft.) the transit of Venus (see Trans. Roy. Soc. Nos. 159 and 161, 1875). This won him the fellowship of the society (1875), to the 'Transactions' of which he had contributed in 1867, 1870, 1871, and twice in 1873. Cambridge conferred upon him the honorary M.A. dedree in 1876, and after his retirement on 1 Oct. 1884 on a special pension granted by government, he was made a C.I.E. (6 June 1885).
At Mussoorie, where he at first lived after retirement, he was an active member of the municipality, captain of the local volunteer corps, and discoverer of the spring from which the water-supply is obtained. Coming to London, he resided in Alleyn park, West Dulwich, where he died on 23 May 1910, being interred at Elmer's End cemetery.
He married at Calcutta in March 1868 Elizabeth Golden, only daughter of R. Malcolm Ashman; by her he had a son and daughter. The son, Lieut. J. A. C. Hennessey, 45th (Rattray) Sikhs, was killed in action at Jandola, Waziristan, in Oct. 1900; memorial prizes for moral worth were founded at his old school, Dulwich.
[Memoir on Indian Surveys, by Sir C. Markhara, 1878, and cont. by C. E. D. Black, 1891; List of Officers in Survey Dept. to Jan. 1884, Calcutta; Indian Survey Report for 1888–5, Calcutta; The Times, 26 May 1910; personal knowledge.]
F. H. B.