ADDRESS. IxXXix 



laboratory in any one of the Qneen's Colleges in Ireland — a want which 

 surely ought not to remain unsupplied. Each of these institutions (the 

 four Scotch Universities, the three Queen's Colleges, and Owens College, 

 Manchester) requires two professors of Natural Philosophy — one who shall 

 be responsible for the teaching, the other for the advancement of science by 

 experiment. The University of Oxford has already established a physical 

 laboratory. The munificence of its Chancellor is about to supply the Univer- 

 sity of Cambridge with a splendid laboratory, to be constructed under the 

 eye of Professor Clerk Maxwell. On this subject I shall say no more at 

 present, but simply read a sentence which was spoken by Lord Milton in the 

 first Presidential Address to the British Association, when it met at York in 

 the year 1831 : — " In addition to other more direct benefits, these meetings 

 " [of the British Association], I hope, will be the means of impressing on the 

 " Government the conviction, that the love of scientific pursuits, and the 

 " means of pursuing them, are not confined to the metropolis ; and I liopc 

 " that when the Government is fuUy impressed with the knowledge of the 

 " great desire entertained to promote science in every part of the empire, they 

 " wiU see the necessity of affording it due encouragement, and of giving every 

 " proper stimulus to its advancement." 



Besides abstracts of papers read, and discussions held, before the Sec- 

 tions, the annual Reports of the British Association contain a large mass 

 of valuable matter of another class. It was an early practice of the Associa- 

 tion, a practice that might weU be further developed, to call occasionally for 

 a special report on some particular branch of science from a man eminently 

 (jualified for the task. The reports received in compliance with these invita- 

 tions have all done good service in their time, and they remain permanently 

 useful as landmarks in the history of science. Some of them have led to 

 vast practical results ; others of a more abstract character are valuable to 

 this day as powerful and instructive condensations and expositions of the 

 branches of science to which they relate. I cannot better illustrate the two 

 kinds of efiicieucy realized in this department of the Association's work than 

 by referring to Cayley's Report on Abstract Dynamics * and Sabine's Report 

 on Terrestrial Magnetism t (1838). 



To the great value of the former, personal experience of benefit received 

 enables me, and gratitude impels me, to testify. In a few pages full of 

 precious matter, the generalized dynamical equations of Lagrange, the 

 great principle evolved from Maupertuis' " least action " by Hamilton, and 

 the later developments and applications of the Hamiltonian principle by 

 other authors are described by Cayley so suggestively that the reading of 

 thousands of quarto pages of papers scattered through the Transactions of the 

 various learned Societies of Europe is rendered superfluous for any one who 

 desires only the essence of these investigations, with no more of detail than is 

 necessary for a thorough and practical understanding of the subject. 



Sabine's Report of 1838 concludes with the following sentence : — " Yiewed 

 " in itself and its various relations, the magnetism of the earth cannot 

 " be counted less than one of the most important branches of the physical 

 " history of the planet we inhabit ; and we may feel quite assured tliat the 

 " completion of our knowledge of its distribution on the surface of the earth 



* Eeport on the Recent Progress of Theoretical Dj'naiuics, by A. Cayley (Report of tlie 

 British Association 1857, p. 1). 



t Eeport on tlio Variations of the Magnetic Intensity observed at different points of (lie 

 Earth's Surface, by Major Sabine, F.E.S. (forming part of the 7th Eeport of the Biitish 

 Association). 



