28 SECTIONAL ADDRESSES 



Acoustics and the British Association. 



In passing to the subject matter of this Address, I may perhaps mention 

 that a search through the Reports of the Association reveals that through- 

 out its entire existence of over a hundred years, no previous Presidential 

 Address in Section A has dealt with acoustical matters. Neither can I 

 find a precedent for an experimental address such as I am venturing 

 to offer you to-day. It is fitting that the subject of acoustics should 

 occupy us in this lecture theatre, which was one of Prof. Barton's last 

 achievements. 



During the course of the search, one could not fail to be impressed by 

 the galaxy of distinguished mathematicians and physicists who have 

 presided over our Section in the past. Here is a random selection of 

 pre-war names : Brewster, Herschel, Forbes, Stokes, Airy, Rankine, 

 Cayley, Wheatsone, Tyndall, Maxwell, Tait, Balfour Stewart, Lord 

 Kelvin, Carey Foster, Johnstone Stoney, the late Lord Rayleigh, Chrystal, 

 G. H. Darwin, Fitzgerald, Sir Oliver Lodge, Schuster, Glazebrook, 

 Riicker, Hicks, Sir J. J. Thomson, Prof. Forsyth, Poynting, Larmor, 

 Sir Chas. Boys, Lamb, Sir Napier Shaw, Lord Rutherford, Hobson, 

 Turner, Callendar, Baker, Sir Frank Dyson and Prof. Whitehead. 



Except for two war years (1917 and 191 8), the British Association has 

 never failed to meet annually, nor has the Section omitted to play its 

 part. Since the war, we find further names no less eminent : Andrew 

 Gray, Prof. O. W. Richardson, Prof. G. H. Hardy, McLennan, Sir Wm. 

 Bragg, Sir George Simpson, Prof. Porter, Prof. Whittaker, Prof. A. 

 Fowler, Lord Rayleigh, Sir Frank Smith, Sir J. J. Thomson, Prof. 

 Rankine, Sir Gilbert Walker, Macdonald, Dr. Aston and Prof. Ferguson. 



It was not until 1843 (twelve years after the inaugural year of the 

 British Association) that the first Presidential Address was given to the 

 Section of Mathematics and Physics by M'CuUagh. His lead was by 

 no means always followed in subsequent years, and even when it was, 

 the address had clearly assumed no particular moment. Stokes's 

 Sectional address in 1862 seems to have occupied about four minutes, 

 while Whewell, the renowned Master of Trinity, in the course of a brief 

 address four years earlier at Leeds, lamented the small size of the meeting 

 room, but on reflection thought it might suffice, as ' we in this Section 

 are very much in the habit of treating our subjects in so sublime a manner 

 that we thin the room very speedily.' Since about 1868, the Sectional 

 programme has invariably included a Presidential Address, though over 

 a long period it was given no title. Lord Kelvin, ever a stalwart supporter 

 of the British Association, was the first to supply a title (in 1876) and kept 

 up the practice in his later addresses, his example being followed by Sir 

 Robert Ball in 1887. But the innovation found no other supporters, and 

 it was not until 1911 that Prof. Turner adopted a title ; since 1920 the 

 Presidential Addresses in Section A have all borne titles. 



As regards the two previous Nottingham meetings, at the first of these 

 in 1866, Wheatstone apparently dispensed with a Sectional Address ; 

 while at the second meeting in 1893, the late Sir Richard Glazebrook 

 gave an address on optical theories and the ether. Those who then 



