Page:History of the Royal Astronomical Society (1923).djvu/186

 158 HISTORY OF THE [1860-; The announcement of Bond's death on 1865 February i seven days after the delivery of De la Rue's address, was mac in the same number of the Monthly Notices that contained tl address. At a later meeting the President was able to assure tl Society that Bond had known of the award before his deat] and greatly appreciated the recognition of his labours. Amor his other achievements, Bond had discovered the crape ring < Saturn and also Hyperion, the eighth satellite of Saturn. Indepei dent discovery of these had been made respectively by " eagle-eyed Dawes and by Lassell. De la Rue's second address was given in 1866 February c the award of the medal to Adams. It was a very able addres and in the preparation of it, as Dr. Glaisher has recorded in h obituary notice of Adams (M.A T ., 53, 199), he had the invaluab assistance of Delaunay, and gave an excellent history of the proble of the secular acceleration of the moon. Adams [1819-92] was President of the Society in 1851 ar 1852, and in the latter year he communicated to our Society ne tables of the moon's parallax. In 1853 he communicated to t] Royal Society his celebrated paper (of ten pages) on the secul acceleration of the moon's mean motion. It was for these tv pieces of work in the development of Lunar Theory that tl award of the medal was made in 1866. In the interval of fourteen years a great controversy rage In 1853, Laplace's discovery in 1787 that the secular variation the eccentricity of the earth's orbit produced secular terms in t] moon's motion was still regarded as having set the question the moon's acceleration at rest. Adams showed that the tri value of the acceleration requires the insertion of addition terms into the equations, and the result of such insertion is decrease the then accepted value of the acceleration. Plai remonstrated, Delaunay intervened. Pontecoulant attacke Hansen calculated. Le Verrier inclined towards an incorre theory because observation supported it. Lubbock, Donkin, ai Cayley joined in the calculations and discussions. " The whc controversy forms a very extraordinary episode in the history physical astronomy ; the indifference with which Adams's Memc of 1853 was at first received, in spite of the interest and importan of the subject, being followed by the violent controversy whi< resulted in so many independent investigations by which Adam* result was confirmed " (Glaisher, M.N., 53, 198). Delaunaj account of the whole discussion appeared in the supplement the Connaissance des Temps for 1864. He says. " L'apparition ( memoire de M. Adams a te un veritable evenement ; c'et? toute une revolution qu'il operait dans cette partie de 1'astronoir