58 SECTION PHYSICS. 



contrasted with exact thirds, the harmonic seventh compared with 

 other forms of minor seventh, and numerous other theoretical results 

 reduced to practical knowledge. 



Of the applications of the various systems, I will only say that in 

 my opinion it is a mistake to apply ordinary music to them indis- 

 criminately. Just systems especially, which have both thirds and 

 fifths nearly perfect, must be studied and written for before they can 

 be used with advantage. I need hardly say that I think, when this is 

 done, the advantage will be great. 



Dr. Guthrie here took the chair. 



The CHAIRMAN : I am sure you will all thank Mr. Bosanquet for 

 his communication, and I am sure we are very glad to hear that there 

 is some practical prospect of this very desirable end being brought 

 about We have now the subject of the limits of audible sounds, and 

 if Dr. Stone will introduce the subject, I hope Mr. Galton will illus- 

 trate it by one or two practical results. 



THE LIMITS OF AUDIBLE SOUND. 



Dr. STONE : At the risk of the accusation of irrepressibility perhaps 

 you will allow me to occupy one or two minutes in the way of the Roman 

 nomenclator of old, to start a subject rather than to complete it. I 

 wish to mention the limits of audible and musical sound. Of course 

 we have them both above and below, at either extreme. We have, also, 

 I am proud to say, a very fine collection of illustrative instruments 

 in the exhibition, and I would name three at the upper limit and 

 three at the lower. The first is a curious instrument of Mr. Griesbnch's 

 which is interesting, not only on account of the perfect way in which 

 he illustrates the upper limits of audibility, but because he contrived 

 it so as to show many principles of musical sound which are con- 

 sidered to be of recent discovery. This is the instrument. It is to all 

 intents and purposes a small organ with a key-board, the pipes of 

 which are exceedingly small. They look rather long, but the greater 

 part of the pipe is foot, and the real acting part is very short indeed. 

 Here is a note which would astonish modern pianists to play. It is so 



