294 



On the Sirene, a new Acoustic Instrument. 



ther the sounds of the machine accorded with the notes of a 

 standard instrument, namely, the Harmonica, consisting of an ar- 

 rangement of steel bars made to vibrate by a bow. Thus ar- 

 ranged, the machine was made to produce the diatonic notes of 

 the gamut, and some beyond them : the revolutions of the plate 

 were ascertained bv the revolutions of a wheel, which made one 

 revolution while the plate made thirteen and a half. 



The vibrations indicated in the table which follows are the re- 

 sults of preliminary experiments as exact as the imperfection of 

 the instrument employed would admit of: it deserves to be re- 

 marked, however, that thcyapproximate vpiy nearly to the theory 

 proposed by Sauveur in his works on Acoustics. I have strong 

 hopes, nevertheless, that I shall be able to push these experiments 

 much further when I shall have completed the apparatus I am 

 now engaged in making, and which, being wholly appropriated 

 to this object, must give results much more exact. 



Table. 



If water is passed through the Sirene instead of air, sound is 

 equally produced, even when it is entirely immersed in the fluidj 

 and the same number of shocks produce the same notes as are 

 done by the air. It is on account of this property of being so- 

 norous in water that I have given it the name of Sirene. 



It may not perhaps be improper to mention, that when the 

 Sirene is moved with a certain quickness it produces octave sounds 

 higher than the last fa of pianos with six octaves, and much 

 better characterized. • i 



XLIV. Ra- 



