ADDKESS. 5 1 



stimulus of our meetings, by the lectures and memoirs to wliich I have 

 had the advantage of listening, and above all, by the many friendships 

 which I owe to this Association, 



Summing up the principal results which have been attained in the last 

 half-century we may mention (over and above the accumulation of facts) 

 the theory of evolution, the antiquity of man, and the far greater anti- 

 quity of the world itself ; the correlation of physical forces and the con- 

 servation of energy ; spectrum analysis and its application to celestial 

 physics ; the higher algebra and the modern geometry ; lastly, the in- 

 numerable applications of science to practical life — as, for instance, in 

 photography, the locomotive engine, the electric telegraph, the spectro- 

 scope, and most recently the electric light and the telephone. 



To science, again, we owe the idea of progress. The ancients, says 

 Bagehot, ' had no conception of progress ; they did not so much as 

 reject the idea ; they did not even entertain it.' It is not, I think, going 

 too far to say that the true test of the civilisation of a nation must now 

 be measured by its progress in science. It is often said, however, that 

 great and unexpected as the recent discoveries have been, there are certain 

 ultimate problems which mtist ever remain unsolved. For my part I would 

 prefer to abstain from laying down any such limitations. "When Park 

 asked the Arabs what became of the sun at night, and whether the sun was 

 always the same, or new each day, they replied that such a question was 

 childish and entii-ely beyond the reach of human investigation. I have 

 already mentioned that, even as lately as 1842, so high an authority as 

 Comte treated as obviously impossible and hopeless any attempt to 

 determine the chemical composition of the heavenly bodies. Doubtless 

 there are questions, the solution of which we do not as yet see our way 

 even to attempt ; nevertheless the experience of the past warns us not 

 to limit the possibilities of the future. 



But however this may be, though the progress made has been so rapid, 

 and though no similar period in the woi-ld's history has been nearly so 

 prolific of great results, yet, on the other hand, the prospects of the 

 future were never more encouraging. We must not, indeed, shut our 

 eyes to the possibility of failure ; the temptation to military ambition ; 

 the tendency to over-interference by the state ; the spirit of anarchy and 

 socialism ; these and other elements of danger may mar the fair prospects 

 of the future. That they will succeed, however, in doing so, I cannot 

 believe. I cannot but feel confident that fifty years hence, when 

 perhaps the city of York may renew its hospitable invitation, my suc- 

 cessor in this chair — more competent, I trust, than I have been to do 

 justice to so grand a theme — will have to record a series of discoveries 

 even more unexpected and more brilliant than those which I have, I fear 

 so imperfectly, attempted to bring before you this evening, for assuredly 

 one great lesson which science teaches is, how little we yet know, and how 

 much we have still to learn. 



E 2 



