340 Dr. Weber on Savart' s Experiments on the 



mena. Thus the fundamental lines, where the sand keeps its 

 position, may have the form fig. 16. No. 1. As the tone be- 

 comes deeper, all these lines approach the end B, so that the 

 interval An, and n n\ and n' n l! , become larger ; but n" finally 

 advances to B, so that the membrane has only two lines left. 

 Another change is shown in fig. 17. 



Savart has formed the hypothesis, that the membrane agi- 

 tated by the undulations of the air is also in a standing and 

 sounding vibration ; that from this sounding membrane waves 

 of sound are proceeding exactly of the breadth of those which 

 arrive at it : that he therefore knew the breadth of the waves 

 of sound proceeding from the membrane, from knowing the 

 breadth of those which arrive at it. From these hypotheses 

 it is inferred, that the modes of vibration produced by various 

 flageolet sounds are gradually transfused into one another by 

 an uninterrupted series of intermediate tones. What now 

 may be said of sounding membranes, says Savart, is probably 

 also the case with sounding elastic plates. But according to 

 Chladni's account, it is not so with sounding plates. Savart 

 thinks that Chladni has been mistaken in his observations. 

 (See the beginning of this paper.) But in all the experi- 

 ments I have hitherto made, I have always found Chladni's 

 observations confirmed. But should Savart find a different 

 result, it would be desirable that he should exactly point out 

 the material, form, and thickness of the plate with which he 

 made his experiments, as well as the manner of his having 

 fastened the plate and made it vibrate, in order that the ex- 

 periment may be repeated *. 



These discoveries of Savart merely concern the extension of 

 small oscillations in form bodies, in membranes; as there is no 

 question here about sounding bodies, nay not even of rever- 

 berating bodies, as one may be convinced by the ear, but only 

 as to vibrations and soundless motions, which however show 

 much similarity to the motions of reverberating and even 

 sounding bodies. 



I had a small wooden square'frame made, which measured in 

 the hollow six Paris-inches in length and breadth. Upon this 

 I glued a sheet of wet English letter-paper (wove paper, with- 

 out any wire-marks), which was perfectly free from thin places 

 or other defects, and glued upon this paper small laths, so that 

 it was equally stretched, and its edge everywhere immoveable. 



* Chladni has investigated, in his Acoustics, Leipzig, 1802. § 114. p. 131. 

 a particular case, in which with a similar fundamental figure, but which once 

 has received a curve outward, and at another time inward, several tones 

 are produced, and has proved that here too no transition from one flageo- 

 let^tone to another, through an uninterrupted series of tones, is manifested. 



Such 



