1890.] 



on the Physical Foundation of Music. 



229 



cut out in comb-fashion, and screwed, as shown in Fig. 12, to a lever 

 handle, the mouth-pieces, or any set of them can be displaced at will, 

 producing any pre-arranged difference of phase. Fig. 9 shows the 



Fig. 8. 



Koenig's Compound Wave-siren for synthetic researches on the quality of 



Compound Tones. 



way in which the 15 movable slits are arranged with respect to the 

 wave-disks and to the one fixed slit of the fundamental note ; they 

 are set in two radial lines for convenience of grouping, and so that 



Q 3 



