430 



Acoustics. 



No. 53286 



53 294 B. 1:1. 



53289. 1:11. 



53 287. 1 : 10. 



53 290. 1 : 20. 



53291. 1:8. 



53 294 A. 1:8. 



52.286. Chemical Harmonica (Apparatus for singing Flames), cf. Fig. 63,287 (W. D. Fig. 211 

 [197]), comprising 4 tubes tuned to give a chord, each provided with stopcock and with 

 cap for covering the tubes so that each tone can be sounded singly 



53.287. - - idem, with covering flaps, Figure (W. D. Fig. 211 [197]) 



53.288. - - i d e m, with only 2 tubes and covering caps 



53.289. - - idem, with 1 tube only, Figure 



53.290. Chemical Harmonica, after Dr. Bresina, Figure (Carls Bepertorium, 18, 1882, 

 p. 84, and Ztschr. zur Forderung des physik. Unterr., 1884, p. 36), with 2 flames, and 

 3 burners on stand for analysing the flames 



53.291. Gas Harmonica, Figure (W. D. Fig. 213 [199]), 2 m high, for showing the existence 

 of overtones along with the fundamental tone, with burner for house gas and 6 conical 

 open resonators of sheet zinc for the overtones g , d 1? b x , d 2 , f 2 (sol,, re 3 , si 3 , re 4 , fa 4 ) j 



53.292. Pyrophone (W. D. Fig. 212 [198]), with one glass tube with two burners .... 



53.293. Tube for Rijke's experiment (W. D. p. 269 [242]), on stand, with wire net and burner 



53.294. Electric Harmonica, after Pflaum, Figs. A and B, for showing that the tone of the 

 gas harmonica is not produced by successive explosions 



The tone is produced by an incandescent platinum win- net. shown plainly in Fie- 53,294 B. 

 As the net is provided with suitable pieces for connecting up to the current it can easily be inter- 

 changed. 



53,294 B. Platinum Wire Netting alone, Figure 



s. d. 



2.16.0 

 3. 4.0 

 2. 0.0 

 1. 6.0 



3. 12. 



2.1(1. 

 0. lli. 

 0. 15. 



2. 10. 

 0. 15. 



(1. 1073, 1068, 



1067, 1070, 1071, 1072. 



