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 calculations, might 'look for the planet and find it, so that this country might have had the full credit of the discovery' (private letter). He sent Airy improved elements of the planet on 2 Sept. 1846, and drew up shortly afterwards a paper on the subject for the British Association, but reached Southampton a day too late to present it. Finally, on 13 Nov. 1846, he laid before the Royal Astronomical Society the long-suppressed investigation in which he had determined, from the irregularities of Uranus, the orbit and place of Neptune (Memoirs Royal Astronomical Soc. vol. xvi.). The importance attached to it was signified by its issue as an appendix to the 'Nautical Almanac' for 1861, and as a supplement to No. 693 of the 'Astronomische Nachrichten' (2 March 1847). A French version, with a brief appendix by Adams, appeared in 1876 in Liouville's 'Journal de Mathématiques' (ii. 83).

The publication stirred widespread excitement. A long and bitter controversy ensued. The scientific world split into 'Adamite' and 'anti-Adamite' factions. But their contentions were unshared by the personages to whom they related. Adams's conduct throughout was marked by the utmost dignity and forbearance. He uttered no complaint; he laid no claim to priority ; Leverrier had no warmer admirer. He made personal acquaintance with him at the Oxford meeting of the British Association in June 1847, and both were Sir John Herschel's guests at 'Collingwood in the ensuing month.

Adams refused knighthood in 1847, but the Adams prize, awarded bi-annually for the best essay in astronomy, mathematics, or physics, was founded in 1848, at the university of Cambridge, to commemorate his 'deductive discovery ' of Neptune. He was elected a fellow of the Royal Society on 7 June 1849. He observed the total eclipse of the sun on 28 July 1851 at Frederiksvaern in Sweden (Memoirs Royal Astron. Soc. xxi. 103). Adams was an unsuccessful candidate for the post of superintendent of the 'Nautical Almanac,' vacant by the death of William Samuel Stratford [q. v.] in 1853. His fellowship at St. John's expiring in 1852, he was elected in February 1853 to a fellowship of Pembroke College, which he held until his death. He occupied the chair of mathematics in the university of St. Andrews during the session of 1858-9, vacating it in consequence of his election, late in 1858, to succeed George Peacock [q. v.] as Lowndean professor of astronomy and geometry at Cambridge. His lectures in this capacity were generally on the lunar theory.

Adams's new tables of the lunar parallax, communicated to the Royal Astronomical Society in 1852, were appended to the 'Nautical Almanac' for 1856. In 1853 he presented to the Royal Society a memoir on the secular acceleration of the moon's mean motion, demonstrating the incompleteness of Laplace's explanation of the phenomenon (Phil. Trans, cxliii. 397). This was highly displeasing to French geometers; but the attacks of Plana, Hansen, and Pontecoulant left unshaken conclusions which were independently verified by Delaunay, Cayley, and Sir John William Lubbock [q.v.] Adams replied to objections in the 'Monthly Notices' for April 1860 ; Plana attempted a rejoinder in a series of letters to Sir John Lubbock in June ; and Pont6coulant continued for some time longer to urge threadbare arguments in the 'Comptes Rendus.' An admirable account of the discussion was inserted by Delaunay in the 'Connaissance des Temps' for 1864. Adams refined his methods and improved his results in papers published in the 'Comptes Rendus' for January 1859 and in ' Monthly Notices,' June 1880. The final upshot was to reduce the value for lunar acceleration from 10" to about 6" a century. Other points connected with the lunar theory were treated of by him in separate memoirs presented at intervals to the Royal Astronomical Society.

The Leonid shower of 1866 directed his attention to the movements of those meteors. Laboriously calculating the effects upon them of planetary perturbations, he applied them as a criterion for the determination of their orbit and period (Monthly Notices, xxvii. 247). This, like most of his work, was definitively done. His published writings in pure mathematics were more elegant than extensive, but he enjoyed manipulating long lines of figures, and, having calculated thirty-one 'Bernouillian numbers,' he employed them to obtain the values of 'Euler's constant' to 263 places of decimals. His aid was frequently asked and granted in computations of ancient eclipses and of other astronomical phenomena. He was an assiduous student of Sir Isaac Newton's works, and catalogued with elaborate care the voluminous collection of his manuscripts presented by Lord Portsmouth to the university. He succeeded Challis as director of the Cambridge observatory in 1861, and the acquisition in 1870 of a fine transit-circle by Simms decided him to undertake one of the star-zones assigned for observation to various co-operators by the German