420 



Acoustics. 



No. 53199 



53 201. 1 : 7. 



53 204. 1 : 3. 



53 208. 1 : 3. 



Sound Generation, Sirens and Blowers. 



s. d. 



62,315. Apparatus after Wertheim, Figure 62,315, p. 957, for demonstrating the tones 



of steel when magnetized (M. P., 9 th Edn., Ill, Fig. 530) i 2. 10. 



53.199. Trevelyan's Rocker, Figure (W. D. Fig. 206 [192]), with resonance box, for pro- 

 ducing tones by a succession of concussions 0. 15. 



53.200. - - idem, without resonance box 0. 12. 



53.201. - - idem, after Konig, Figure 0. 14. 



52.028. Savart's Toothed Wheels, see Fig. 52,028, p. 283; 4 wheels, giving the common 



chord, suitable for Whirling Table, of zinc 0. 9. 



52.029. --idem, of brass 0. 12. 



52,021. Siren Disc, F i g. 52,021, p. 283 (Seebeck's Siren), with four rows of holes, giving 



the major chord, for placing on the whirling table 0. 5. 



53,203 a. Siren Disc, with 8 rows of holes, giving the scale, for the Whirling Table ... 0. 7. 



53,203 b. - - idem, with 8 rows of holes, giving major and minor chords 0. 7. 



53,204. Pipe with 4 nozzles, Figure, for blowing the preceding Siren Discs 0. 5. 



52.026. Siren Disc after Oppelt, with 22 rows of holes, for placing on the Whirling Table 0. 16. 



The disc has 22 rows of holes; 15 give simple tones, 7 give different intervals as combined tones. 



52.027. Siren Disc after Appunn, for placing on the Whirling Table, with 32 rows of holes; 

 gives the simple chromatic scale, the passage of thirds, also the entire song, ,,Du Schwert 



an meiner Linken" in the four parts 3. 6. 



52.024. Wave Siren Disc after Konig, for placing on the Whirling Table, with 2 tubes for 

 blowing the rows of holes and the wave line 0. 15. o 



The Wave Siren Disc has 4 rows of holes having respectively 32, 40, 48 and 64 holes and a wave 

 line on the edge corresponding to the algebraic addition of 4 sine curves corresponding with the above 

 numbers of vibrations. When the wave line is blown upon, the result is a sound which is broken up 

 by the ear into its single constituents, prima, third, fifth and octave. The disc is excellently adapted 

 for explaining the sound action of the phonograph and gramaphone. 



52.025. - - idem, after Konig, larger, shaped to correspond to the flame image of the tone. 

 Is supplied hi the intervals 8:9, 8 : 11, 8 : 12, 8 : 13, 8 : 15, 8 : 16, 8 : 18, 8 : 20, 



8 : 23, 8 : 24 Price each 3. 6. 



53.208. Universal Mouthpiece for blowing the cavum oris, flasks etc.; comprising rubber tubing 

 with flat tapering brass tube (W. D. p. 312). with conical endpiece for inserting in a 



valve aperture of the blowing table 0. 7. <) 



53.209. Siren after Cagniard de Latour, Figure, small pattern, with row of 12 holes, with- 

 out counting mechanism (Helmholtz, Tonempfindungen, 4 th Kdn., 1877, p. 22), with 

 conical tube for placing on the wind chest. All holes are blown through simultaneously, 



thus adding to the intensity of the effect 1 . 10. 



53,2.10. i d e in, with counting mechanism, Figure (M. P. I, Figs. 673 675 [699701]) 2. 0. ( 



53.211. -- idem, larger pattern, with series of 20 holes, without counting meetianism, 

 Figure, with conical tube attachment for placing on the wind chest and with wood 

 base for protecting 



53.212. - - idem, with counting mechanism 4. 10. 



' i :isoi, 1051. 



1054, 4146. 



