592 



Original Articles. 



[Oct. 



most delicate philosophical instrument. This apparatus is constructed 

 with the greatest care, in order to produce certain musical effects 

 which are characteristic of each kind of instrument, and the slightest 

 uncertainty in the quality of the sound will make the difference 

 between a good and bad instrument. 



It would be supposed that the physical principles involved in so 

 delicate a matter would be, to a certain extent at least, understood by 

 the workman or the manufacturer, but, strange to say, this is not the 

 case. Although the various musical instruments in use at present 

 have been constantly improved until the quality of the sound leaves 

 little to be desired, all this excellence appears to be the result of pure 

 empiricism, of experiment, and of the rule of thumb. It is only in the 

 last few years that any serious attempts have been made to ascertain 

 on what the quality of sound depends, and, indeed, what it is that is 

 meant by the term quality. Among these workers Professor Helmholtz, 

 of Heidelberg, occupies the foremost place. He has been enabled, by 

 means of peculiar apparatus devised by himself, to analyze various 

 kinds of sounds, and to determine the nature of that property of 

 sound which is called quality. 



Musical sounds differ in pitch and in loudness. The pitch is 

 regidated by the frequency, and the loudness by the extent, of the 

 vibrations ; but though the pitch and the loudness may be the same, 

 the sound of a violin differs very greatly from that of the trumpet on 

 the one hand, and from the flute or tuning-fork on the other ; that is, 

 though the same for musical purposes in all other respects, the quality 

 is different. 



The following tables will be found useful for indicating the 

 number of vibrations requisite for, and the names of the notes in the 

 musical scale, as it will frequently be necessary to mention them by 

 name, and it would be inconvenient to have recourse to the staff: — 



Notes. 



C B 



C B 



c b 



c' b' 



c" b" 



c'" V" 



c"" b"" 



C 



33 



66 



132 



264 



528 



1056 



2112 



D 



37-125 



74-25 



148-5 



297 



594 



1188 



2376 



E 



41-25 



82-5 



165 



330 



660 



1320 



2640 



P 



44 



88 



176 



352 



704 



1408 



2816 



G 



49-5 



99 



198 



396 



792 



1584 



3168 



A 



55 



110 



220 



440 



880 



1760 



3520 



B 



61-875 



123-75 



247-5 



495 



990 



1980 



3960 



Third 

 of 



Fifth 

 of 



m 





E F 



D. E. ' ' 



G A ]j c d e f 



132 165 198 



"27 



c, 



33 



