Dictionary of National Biography, 1885-1900/Johnson, Manuel John

JOHNSON, MANUEL JOHN (1805–1859), astronomer, was the only son of John William Johnson of Macao, China, where he was born on 23 May 1805. Educated at Addiscombe College, he entered the St. Helena artillery in 1821, and became aide-de-camp to General Walker, who encouraged his taste for astronomy, and induced the East India Company to found an observatory in the island. Johnson made two trips to the Cape, in 1825 and 1828, to advise with Fallows about its construction, and began observing in November 1829 with a transit instrument of 3.8 inches aperture and a mural circle 4 feet in diameter. By April 1833 he had secured materials for ‘A Catalogue of 606 principal Fixed Stars in the Southern Hemisphere,’ printed at the expense of the East India Company in 1835, and distinguished by the Royal Astronomical Society's gold medal (Memoirs, viii. 298). This important catalogue was, besides the Madras catalogues, the only source for exact places of the fixed stars situated beyond the reach of the observatories of Europe. Johnson also observed at St. Helena the solar eclipse of 27 July 1832, and the opposition of Mars, October to December 1832. Upon the disbanding of the artillery corps he returned to Europe, and after some months of continental travel matriculated at Magdalen Hall, Oxford, on 15 Dec. 1835, graduating B.A. 1839, and M.A. 1842. Appointed in 1839 to succeed Professor Rigaud [q. v.] in the charge of the Radcliffe observatory, he quickly gave to the establishment high practical importance. With Mr. Lucas as his sole assistant he laboured indefatigably at the redetermination of Groombridge's circumpolar stars, reducing by day the observations made by night, and publishing with great regularity eighteen volumes of the ‘Radcliffe Observations.’ Sir Robert Peel, then one of the Radcliffe trustees, aided him to procure an improved instrumental outfit. A transit-circle by Simms was erected in 1843, and a heliometer by Repsold of Hamburg in October 1849. The latter instrument, with an object-glass 7½ inches in diameter, is still the largest of its kind in existence, and was fully described by Johnson in the eleventh volume of ‘Observations.’ He observed with it in 1850 twenty-six important double stars, and in 1852–3 measured the chief stars of the Pleiades and the annual parallaxes of 61 Cygni, 1830 Groombridge, and α Lyræ (Radcliffe Observations, vol. xiv.). Similar series for Castor, Arcturus, and α Lyræ were obtained in 1854–5 (ib. vol. xvi.), after which he virtually relinquished the use of the heliometer. A second assistant having been added to his staff in 1851 in the person of Norman Pogson, he proposed to undertake the revision of Piazzi's ‘Catalogue,’ but substituted the plan (frustrated by his premature death) of forming a catalogue of nearly 1,500 stars remarkable for physical or systematic peculiarities (Monthly Notices, xvi. 98). The photographic mode of registering meteorological data was adopted by him in 1854, and an electrical transit-recorder installed in 1858. He was elected a fellow of the Royal Society in 1856, and acted as president of the Royal Astronomical Society in 1857–8. He died suddenly of heart disease on 28 Feb. 1859. He was popular in the university, and the observatory became in his time a chief resort of the Oxford leaders of the high church party, among them of John Henry (afterwards Cardinal) Newman. Johnson left a widow, a daughter of Dr. Ogle, and several young children. He indulged artistic tastes by forming a fine collection of engravings, some of which were shown at the Manchester Exhibition in 1857. His catalogue of 6,317 circumpolar stars was in the printers' hands when he died. It was published in 1860 under the editorship of Mr. Main, and has proved of great value for deducing proper motions. Two additional volumes of his observations (Radcliffe Observations, vols. xix. xx.) were reduced and published by Mr. Main. A prize, instituted in Johnson's memory in 1862, is offered once in four years at Oxford for an essay on an astronomical or meteorological subject.

[Monthly Notices Royal Astronomical Society, xix. 169, xx. 123; Proceedings of Royal Society, vol. x. p. xxi; Mozley's Reminiscences, ii. 189; Times, 4 March 1859; André et Rayet's L'Astronomie Pratique, i. 57; Mémoires couronnés par l'Académie de Bruxelles, XXIII. ii. 64, 1873 (Mailly); Annuaire de l'Observatoire de Bruxelles, 1864, p. 367 (Mailly); Foster's Alumni Oxonienses.]

A. M. C.