Both these posts he retained till his death; but he always resided at Armagh. In 1872 he was nominated prebendary of St. Patrick's, Dublin.
The work which gives Robinson his title to fame was done at Armagh Observatory, founded by Richard Robinson, first baron Rokeby [q. v.], in 1793. Little work had been done there before his appointment in 1823, but between 1827 and 1835 additional instruments were supplied by Lord John George Beresford, and the new astronomer's energy bore early fruit in the publication of ‘Armagh Observations, 1828–30’ (vol. i. pts. i., ii., iii., 1829–32). In 1859 he published his great book, ‘Places of 5,345 Stars [principally Bradley's stars] observed at Armagh from 1828 to 1854.’ For a great part of this period there are few other contemporary observations. Robinson's results have been used by the Prussian astronomer Argelander in determining proper motions, and also for the ‘Nautical Almanac.’ Robinson himself made many of the observations, besides writing an introduction on the instruments used. It was chiefly for this work that he obtained a royal medal from the Royal Society in December 1862 (Royal Society's Proceedings, 1862–3, pp. 295–7). The observatory instruments having been again improved, one thousand of Lalande's stars were observed between 1868 and 1876, and the results published in ‘Transactions of the Royal Dublin Society,’ 1879. The observations made from 1859 to 1883, nearly all under Robinson's direction, were published by his successor, J. L. E. Dreyer, in the ‘Second Armagh Catalogue of 3,300 Stars,’ 1886. Robinson also made a determination of the constant of nutation which deserves mention, but has not come into general use. In 1830 he was one of forty members of the nautical almanac committee (Sophia Elizabeth de Morgan, Memoir of De Morgan, p. 333).
Robinson is also well known as the inventor of the cup-anemometer, of which he devised the essential parts in 1843. He completed it in 1846, and in the same year described it before the British Association. At various subsequent times he made experiments and wrote papers on the theory of the instrument. While at Armagh he made many researches in physics. He published a great many papers on astronomy, as well as others dealing with such diverse subjects as electricity and magnetism, heat, the cup-anemometer, sun-dials, turbines, air-pumps, gasometers, fog-signals, and captive balloons. They are to be found in the ‘Royal Irish Academy Transactions,’ 1818–59; ‘Royal Irish Academy Proceedings,’ 1836–77; ‘Memoirs of the Royal Astronomical Society,’ 1831–52; ‘Monthly Notices of the Royal Astronomical Society,’ 1873–82; ‘British Association Report,’ 1834–69; ‘Philosophical Magazine,’ 1836–67; ‘Royal Society Philosophical Transactions,’ 1862–81; ‘Royal Society Proceedings,’ 1868, 1869; and ‘Journal of Microscopic Science,’ 1855.
Robinson was intimately associated with William Parsons, third earl of Rosse [q. v.], in the experiments culminating in the erection of Rosse's great reflector at Parsonstown, and lived on terms of intimacy with Sir William Fairbairn, Whewell, Sir Samuel Ferguson, and other men of learning. He was elected F.R.A.S. on 14 May 1830, and F.R.S. on 5 June 1856. He was president of the Royal Irish Academy, 1851–6, and president of the British Association at Birmingham in 1849. The degrees of D.D., LL.D. (Dublin and Cambridge), D.C.L. (Oxford), honorary and corresponding membership of various foreign societies, were also conferred on him.
He died suddenly on 28 Feb. 1882 at the observatory, Armagh. Robinson married, first, in Dublin, in 1821, Eliza Isabelle Rambaut (d. 1839), daughter of John Rambaut and Mary Hautenville, both of Huguenot families. By her he had three children; one, Mary Susanna, married in 1857 Sir George Gabriel Stokes, first baronet (1819–1903). In 1843 he married a second wife, Lucy Jane Edgeworth, youngest daughter of Richard Lovell Edgeworth, and half-sister to Maria Edgeworth (see Ferguson, op. cit. infra). A portrait, painted by Miss Maude Humphrey from a photograph, is at the Royal Irish Academy. Sir George and Lady Stokes (his daughter) possessed two portraits of him by his father, and a good medallion by Mr. Bruce Joy.
It is seldom that ‘the early promise of boyhood has been succeeded by a more brilliant manhood’ than in Robinson's career. ‘Eminent in every department of science, there was no realm of divinity, history, literature, or poetry that Robinson had not made his own.’ Gifted with brilliant conversational powers and eloquence, and with a marvellous memory, he was of powerful physique, and showed exceptional coolness in the presence of danger.
Besides the works noticed, and some sermons and speeches, Robinson published: 1. ‘Report made at the Annual Visitation of Armagh Observatory,’ 1842. 2. ‘British Association Catalogue of Stars’ (completed by Robinson, Challis, and Stratford), 1845. 3. ‘Letter on the Lighthouses of Ireland,’ 1863.
