No. 53214. 



Generation of Sound, Sirens, Blowers. 



421 



53 209. 1 : 4. 



53 210. 1 : 4. 



53 211. 1 : 4. 



53 213 A. 1:4. 



53 213 B. 1:3. 



53 214. 1 : 6. 



53,213. Chord Siren aftei Dove, Figs. A and B, with 4 stops with stop catches, to enable 

 the tones to be sounded singly or together, and with counting mechanism (Helmholtz, 

 Tonempfindungen, 4 th Edn., 1877, p. 23; M. P. I, Figs. 839, 840 [814, 815]) .... 



53,214. Siren arranged to sound under water, Figure, with glass vessel 



This Siren, built on the principle of Cagniard de Latour, is placed in the glass vessel supplied 

 and connected by a length of tubing either with the water lead or with a tank placed on a higher level. 

 If the stopcock is opened the water flows through the siren and the latter sounds. 



6. 14. 



6. 0.0 



Cl. 3669. 3669, 3669 b. 3669 c, 

 3669 e, 36711. 



