ON BEATS OF IMPERFECT HARMONIES. 413 



note false. It is not because of the comparative 

 slowness of the beat on the multiple harmony ; 

 for by taking alternately beats with one note 

 slightly false in a binary harmony, and the same 

 note made more false in a ternary or multiple 

 harmony to such a degree as to give the same 

 number of beats, I have always found the beats in 

 the latter case much more prominent than in the 

 former. Thus by taking first the perfect harmony 

 C E G (4, 5, 6), and the three binary harmonies 

 C G (2 : 3), C E (4 : 5), E G (5 : 6), and flattening 

 slightly any one of the three notes by screwing on 

 a small mass of brass to cither or to each prong 

 of the tuning-fork producing it, it is easy after a 

 little practice to count the beats on each of the 

 binary harmonies. Thus, for example (supposing 

 E, to designate a note of a slightly lower pitch than 

 E), after a little practice it is easy to count the 

 beats on C E, and on the E, G, and to verify that 

 their frequencies are, the first of them four times, 

 and the second of them six times, the error of 

 frequency of the E,, and then to verify that 

 the much louder beats on the ternary har- 



