258 A Short History of Astronomy [CH. X. 



biographer * remarks, " it could not be foreseen that his 

 astronomical labours would lead to any establishment in 

 life, and it became necessary for him to embrace a pro- 

 fession." He accordingly took orders, and was fortunate 

 enough to be presented almost at once to two livings, the 

 duties attached to which do not seem to have interfered 

 appreciably with the prosecution of his astronomical studies 

 at Wansted. 



In 1721 he was appointed Savilian Professor of Astro- 

 nomy at Oxford, and resigned his livings. The work of the 

 professorship appears to have been very light, and for more 

 than ten years he continued to reside chiefly at Wansted, 

 even after his uncle's death in 1724. In 1732 he took a 

 house in Oxford and set up there most of his instruments, 

 leaving, however, at Wansted the most important of all, 

 the " zenith-sector," with which his two famous discoveries 

 were made. Ten years afterwards Halley's death rendered 

 the post of Astronomer Royal vacant, and Bradley received 

 the appointment. 



The work of the Observatory had been a good deal 

 neglected by Halley during the last few years of his life, 

 and Bradley's first care was to effect necessary repairs in 

 the instruments. Although the equipment of the Obser- 

 vatory with instruments worthy of its position and of the 

 state of science at the time was a work of years, Bradley 

 had some of the most important instruments in good 

 working order within a few months of his appointment, 

 and observations were henceforward made systematically. 

 Although the 20 remaining years of his life (1742-1762) 

 were chiefly spent at Greenwich in the discharge of the 

 duties of his office and in researches connected with them, 

 he retained his professorship at Oxford, and continued to 

 make observations at Wansted at least up till 1747. 



207. The discovery of aberration resulted from an attempt 

 to detect the parallactic displacement of stars which should 

 result from the annual motion of the earth. Ever since 

 the Coppernican controversy had called attention to the 

 importance of the problem (cf. chapter iv., 92, and 

 chapter vi., 129), it had naturally exerted a fascination 



* Rigaud, in the memoirs prefixed to Bradley's Miscellaneous 

 Works. 



