Cooper, Edward Joshua (DNB00)

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COOPER, EDWARD JOSHUA (1798–1863), astronomer, born at Stephen's Green, Dublin, in May 1798, was the eldest son of Edward Synge Cooper, upon whom, in 1800, through the death of his father, the Right Hon. Joshua Cooper of Markree Castle, co. Sligo, and the ill-health of his elder brother, devolved the management of the large family estates. From his mother, Anne, daughter of Harry Verelst, governor of Bengal, Cooper derived his first notions of astronomy. The taste was hereditary on the father's side also, and was confirmed by visits to the Armagh observatory during some years spent at the endowed school of that town. His education was continued at Eton, whence he passed on to Christ Church, Oxford, but left the university after two years without taking a degree. The ensuing decade was mainly devoted to travelling. By his constant practice of determining with portable instruments the latitudes and longitudes of the places visited, he accumulated a mass of geographical data, which, however, remained unpublished. In the summer of 1820 he met Sir William Drummond at Naples, and, by the interest of a controversy with him on the subject of the Dendera and Esneh zodiacs, was induced to visit Egypt for the purpose of obtaining accurate copies of them. He accordingly ascended the Nile as far as the second cataract in the winter of 1820–1, and brought home with him the materials of a volume entitled ‘Views in Egypt and Nubia,’ printed for private circulation at London in 1824. A set of lithographs from drawings by Bossi, a Roman artist engaged by Cooper for the journey, formed its chief interest, the descriptive letterpress by himself containing little novelty.

His excursions eastward reached to Turkey and Persia, while in 1824–5 he traversed Denmark, Sweden, and Norway, as far as the North Cape. Unremitting attention to its conditions led him to regard Munich and Nice as the best adapted spots in Europe for astronomical observation. Succeeding on his father's death in 1830 to his position at Markree, he immediately determined upon erecting an observatory there. An object-glass by Cauchoix, 131/3 inches across and of 25 feet focal length, the largest then in existence, was purchased by him in 1831, and mounted equatorially by Thomas Grubb of Dublin in 1834. Cast iron was for the first time employed as the material of the tube and stand; but a dome of the requisite size not being then feasible, the instrument was set up, and still remains, in the open air. A five-foot transit by Troughton, a meridian-circle three feet in diameter, fitted with a seven-inch telescope, ordered in 1839 on the occasion of a visit to the works of Ertel in Bavaria (see Doberck, Astr. Nach. xcii. 65), and a comet-seeker, likewise by Ertel, acquired in 1842, were successively added to the equipment of what was authoritatively described in 1851 as ‘undoubtedly the most richly furnished of private observatories’ (Monthly Notices, xi. 104).

Cooper worked diligently in it himself when at Markree, and obtained, March 1842, in Mr. Andrew Graham an assistant who gave a fresh impulse to its activity. By both conjointly the positions of fifty stars within two degrees of the pole were determined in 1842–1843 (ib. vii. 14); systematic meridian observations of minor planets were set on foot; the experiment was successfully made, 10–12 Aug. 1847, of determining the difference of longitude between Markree and Killiney, ninety-eight miles distant, by simultaneous observations of shooting stars; and a ninth minor planet was discovered by Graham 25 April 1848, named ‘Metis,’ at the suggestion of the late Dr. Robinson, because its detection had ensued from the adoption of a plan of work laid down by Cooper. Meteorological registers were continuously kept at Markree during thirty years from 1833, many of the results being communicated to the Meteorological Society. In 1844–5 Cooper and Graham made together an astronomical tour through France, Germany, and Italy. The great refractor formed part of their luggage, and, mounted on a wooden stand with altitude and azimuth movements, served the former to sketch the Orion nebula, and to detect independently at Naples, 7 Feb. 1845, a comet (1844, iii.) already observed in the southern hemisphere.

From the time that the possibility of further planetary discoveries had been recalled to the attention of astronomers by the finding of Astræa 8 Dec. 1845, Cooper had it in view to extend the star-maps then in progress at Berlin, so as to include stars of the twelfth or thirteenth magnitude. A detailed acquaintance with ecliptical stars, however, was indispensable for the facilitation of planetary research—Cooper's primary object—and the Berlin maps covered only an equatorial zone of thirty degrees. He accordingly resolved upon the construction of a set of ecliptical star-charts of four times the linear dimensions of the ‘Horæ’ prepared at Berlin. Observations for the purpose were begun in August 1848, and continued until Graham's resignation in June 1860. The results were printed at government expense in four volumes with the title ‘Catalogue of Stars near the Ecliptic observed at Markree’ (Dublin, 1851–6). The approximate places were contained in them of 60,066 stars (epoch 1850) within three degrees of the ecliptic, only 8,965 of which were already known. A list of seventy-seven stars missing from recent catalogues, or lost in the course of the observations, formed an appendix of curious interest. The maps corresponding to this extensive catalogue presented by his daughters after Cooper's death to the university of Cambridge, have hitherto remained unpublished. Nor has a promised fifth volume of star places been forthcoming. For this notable service to astronomy, in which he took a large personal share, Cooper received in 1858 the Cunningham gold medal of the Royal Irish Academy. He had been a member of that body from 1832, and was elected a fellow of the Royal Society 2 June 1853. Cooper had observed and sketched Halley's comet in 1835; Mauvais' of 1844 was observed and its orbit calculated by him during a visit to Schloss Weyerburg, near Innsbrück (Astr. Nach. xxii. 131,209). The elements and other data relative to 198 such bodies, gathered from scattered sources during several years, were finally arranged and published by him in a volume headed ‘Cometic Orbits, with copious Notes and Addenda’ (Dublin, 1852). Although partially anticipated by Galle's list of 178 sets of elements appended to the 1847 edition of Olbers's ‘Abhandlung,’ the physical and historical information collected in the notes remained of permanent value, and constituted the work a most useful manual of reference. The preface contains statistics of the distribution in longitude of the perihelia and nodes of both planetary and cometary orbits, showing what seemed more than a chance aggregation in one semicircle. Communications on the same point were presented by him to the Royal Astronomical Society in 1853 (Monthly Notices, xiv. 68), to the Royal Society in 1855 (Proc. vii. 295), and to the British Association in 1858 (Report, ii. 27).

Cooper succeeded to the proprietorship of the Markree estates on the death without issue in 1837 of his uncle, Mr. Joshua Cooper, and was conservative member of parliament for Sligo co. from 1830 to 1841, and again from 1857 to 1859. He was twice married: first to Miss L'Estrange of Moystown, King's County, who survived but a short time, and left no children; secondly to Sarah Frances, daughter of Mr. Owen Wynne of Haslewood, co. Sligo, by whom he had five daughters. Her death preceded by a brief interval, and probably hastened, his own. He died at Markree Castle 23 April 1863, having nearly completed his sixty-fifth year. He was a kind as well as an improving landlord; his private life was blameless, and he united attractiveness of manner to varied accomplishments. He kept up to the last his interest in scientific pursuits, and numerous records of his work in astronomy were printed in the ‘Monthly Notices,’ the ‘Astronomische Nachrichten,’ and other learned collections. He imparted his observations of the annular eclipse of 15 May 1836 to the Paris Academy of Sciences (Comptes Rendus, xxvi. 110). For some years after his death the Markree observatory was completely neglected. It was, however, restored in 1874, when Mr. W. Doberck was appointed director, and the great refractor began to be employed, according to Cooper's original design, for the study of double stars.

[Proc. R. Soc. xiii. i; Observatory, vii. 283, 329 (Doberck); Times, 27 April 1863; Burke's Landed Gentry, 1868; R. Soc. Cat. Sc. Papers.]

A. M. C.