408 EXPERIMENTS ON DISCORD AND CONCORD.- 



pleasant dissonance if sounded upon any common musical instru- 

 ment, sounds quite agreeable if the notes employed are free from 

 the overtones, and the rapid beats to which they give rise. Such 

 an interval may be taken between the major and minor third. Of 

 three c" tuning-forks, such as may be easily purchased, one is left- 

 unaltered, so as to give a minor third with a common tuning- 

 fork (a 1 ) ; but one fork is filed down a little at the end until it 

 sounds c"$, that is, the major third of a! ; the third fork is also filed 

 down, but only so far that its note may lie half-way between 

 c" and c"$. The last of these forks struck together with a' and 

 placed upon the table gives as good a consonance as a/, c", and 



