|g8 PROPAGATION OF SOUND IN WATER. 



This prefer- And thus tnaj" any operation in duodecimals be perforni- 



c© imoiirule. ^^ ^^ readily as common multiplication, and the result ob- 

 tained to the greatest degree of accuracy, on both of which 

 accounts, I consider is as preferable to the rule commonly 

 given for this purpose. 



V. 



' On the Propagation of Soimd through nnelastic Fluids. In 

 a Letter from Francis Ellis, Esq, 



To Mr, NICHOLSON. 

 SIR, 



Fropagation of Jj^^ Have accidentally become acquainted with a fact relative 



sound through ^ ^ propai?ation of sound throuorh unelastic fluids, which 



■water. i t ^ o 



seems new ; and if really so, you may perhaps deem it or 

 sutRcient interest, to be made known through the medium ©f 

 your Journal. 



The soand ec- Bathing in a warm bath at Cheltenham, and plunging my 



casioned by \^q^^ under the water, I wassuprised by a harsh, disagreeable 

 the Gondensa- _ ^ j ' o 



tttaa of steam, sound, and jar through both ears, resembling the sound and 

 sensation, that would, I imagine, be received, were a sheet 

 of tin laid on each ear, and struck simultaneously with two 

 small hammers. Induced by curiosity to examine whence 

 this could proceed, I observed, that the bath, which is ten 

 er twelve feet square, was heated by steam conveyed into it 

 at one of its angles by a metallic tube; and that the conden- 

 sation of the steam produced at intervals in this tube a dull 

 clicking sourid. By immersing one ear in the bath, and 

 keeping the other in the air, I ascertained, that it was this 

 sound altered and augmented by being propagated through 

 the water of the bath, which had caused the harsh snapping 

 noise, and jarring sensations, that I have already described. 

 The distance of my head from the entrance of the steam- 

 tube into the bath was seven or eight feet : and it is remark- 

 able, that, when it was submerged, 1 had distinct, though 

 simultaneous sensations of the jarring sound in each ear. 

 I am, Sir, 



Your very obdient servant, 

 Somerset Place, Bath, FRANCIS ELLIS. 



10/ADec. 1909» Observ 



