1881.] 



President's Address. 



41 



but certain it is that he showed the fertility of the method by con- 

 tinuing to deduce from it an apparently inexhaustible flow of theorems, 

 even after the more serious part of his mathematical work had been 

 done. And there is little doubt that long after the time when many 

 subsequent works have fulfilled their purpose, and have fallen into 

 a natural oblivion, his "Apercu Historique," his " Geometrie Supe- 

 rieure," and the fragment of his " Traite des Sections Coniques," will 

 be regarded as classics in the library of the mathematician. 



Turning to the home list, the remark made in my last address, viz., 

 that our losses had been mainly among our older Fellows, might be 

 repeated with even more emphasis on the present occasion. Of the 

 twenty-two who have died during the intervening period nine had 

 reached the age of three score and ten, eight that of four score, and one, 

 Dr. Billing, had attained his ninety-first year. 



In Lord Beaconsfield and Sir James Colvile we have lost two distin- 

 guished members, elected under the statute which gave a new definition 

 of the privileged class a few years ago. Lord Hatherley will be recol- 

 lected as having served on our Council within recent years, and as 

 having often given us very useful advice on subjects requiring the 

 sound judgment of an experienced mind. Although Lord Hatherley 

 would doubtless have been elected, as a member of the Privy Council, 

 under the statute above mentioned, it is perhaps worth remark that 

 he was elected under statute previously existing, and that his fellow- 

 ship dated from the year 1833. 



The late Dean of Westminster furnishes another instance of the 

 wise exercise of a power which the Royal Society has always reserved 

 to itself, notwithstanding the changes made in 1847, of electing from 

 time to time men of eminent distinction in other avocations of life 

 than those of strict science. Of Dr. Stanley's attainments and merits 

 in those other directions it is not my province to speak ; and, indeed, 

 it is the less necessary that I should do so, for they were so many and 

 so varied that in one way or other they were known to all. But he 

 was conspicuous, both among the members of his own profession and 

 among many others who have neither predilection nor training for 

 actual science, for his genuine and honest sympathy with its principles 

 and its objects, and with the labours of those who cultivate it. 



In Dr. Lloyd, whose age was coeval with the century, and who was 

 a fellow-worker with Herschel, Whewell, Peacock, and Sir W. H. 

 Hamilton, we seem to have lost one of the links which connected us 

 with a past generation. While himself no mean mathematician, he was 

 distinguished especially in the sciences of optics and of magnetism. 

 In the subject of optics he had the rare opportunity of supplying 

 the experimental verification of Sir W. R. Hamilton's brilliant 

 geometrical conclusions on the configuration of the wave- surface ; 

 and it was largely due to his patience, his delicacy of touch, and 



