xxxvi Annual Report of the Cowicil. 



Oxford Mathematical Society. Ill health compelled him to 

 take a rest in 1890, and he visited Australia, taking temporary 

 charge of a church in Sydney. After his return he became, in 

 1892, minister of Heath, near Halifax. In 1895 he retired from 

 the ministry, and afterwards resided at Forest Hill, eagerly 

 pursuing to the last his mathematical studies, and doing much 

 honorary preaching, tem[jerance, and philanthropic work. 



It was as a mathematician that Mr. Harley attained dis- 

 tinction, but science had never more than a secondary claim on 

 his time. Of his mathematical work JSatiire says: — "The 

 application of mathematics to logic, as developed by George 

 Boole, captivated his intelligence, and he became the most 

 notable of Boole's admirers and followers, as also his biographer. 

 His greatest mathematical achievements were, however, in 

 another field. The unsolved problem of the solution of quintic 

 equations fascinated him. Having once granted the impossibility 

 of the solution by radicals, he proceeded to exhibit with remark- 

 able power and patience the place of certain sextic resolvents 

 in connection with such equations. Simultaneously, the la'e 

 Sir James Cockle was engaged on like work ; but Harley was the 

 clearer writer on the difiticult subject. Their work, and in par- 

 ticular Harley's, -was welcomed enthusiastically by Cayley, who 

 himself took it up and continued it. All three probably were 

 not aware at the time that certain continental writers had 

 possessed some of their ideas beforehand ; but everyone must 

 recognise that Harley's development of the ideas was masterly. 

 Ii secured for him the Fellowship of the Royal Society in 1863." 



Mr. Harley was twice secretary, and three times vice- 

 president, of the "A" Section of the British Association. 



His contributions to the literature of pure mathematics and 

 symbolic logic were numerous. Of these, the following were 

 contributed to this Society : — 



Papers : — 

 *'On Impossible and certain other Surd Equations."' (1851,) Mem. (2) 

 ix. 207. 



