C 2GG THEORY OF COMPOUND SOUNDS. 



ihc founds arrive at the ear " in the fame direction." p. 1:31. 

 Surely Mr. Gough will not deny the poflibility of fuch a co- 

 incidence in direction, fo far at leaf! that the phyfical effefi 

 may be the fame as if the coincidence were perfect : when, 

 for in fiance, we Men to two or more founds palling through 

 a long tube, or to the various fubordinate founds of the fame 

 chord or pipe. If he be actually difpofed to deny the perfect 

 coincidence in practical cafes, I (hall only appeal to experi- 

 ence, which (hows that the effect of a third found is raoft dif- 

 tinctly heard, whenever the theory leads us to expedt it ; but 

 there will always be a much greater portion of each found fo 

 reflected from the furrpunding objects as not to coincide in 

 direction fufficiently for coalefcence, and hence the original 

 notes will always be much more audible than the new com- 

 pound. The ear indeed appears to have greater powers of 

 analyfis than one would naturally have expected, it decom-, 

 pofes a " compound" juft as if it were a mere M mixture/' 

 not only in this cafe but in many others : how it performs this 

 not by lofmg operation, I do not pretend to determine. When Mr. Gough 

 their refpeftive re p re fents me as maintaining that two mufical firings, differ-. 



tones in one fin- ... . r . . .. . , . . ., 



g!e found; but i.ng in, the times of their vibration, and happening to vibrate m 

 by producing an concert, do no.t occafion two diftinct founds, and that the 

 Jr found. * waves of air are compelled by their mutual interference ta 

 coalefce, thereby producing a new fucceffion of pulfes, con- 

 fiituting a fmgle found in the place of the former ; his expref, 

 lions tend to impute to me an opinion which could only be. 

 maintained by a perfon who had never heard a fingle mufical 

 compofition, or ever been prefent a,t the. converfation of a, 

 mixed company. 

 All imperfe£l I am not folicitous for the application, of the term compound 



by coalefcence, to the human Voice ; but Mr. Gough can 

 fcarcely form to himfelf a diflinct conception of it, very dif- 

 ferent from mine. A mixture of imperfect uniibns would in- 

 evitably be accompanied by the production of beats; and if he 

 alfert that the imperfection is too fmall to produce this effect, 

 I will only requeft him to. affign any reafonable limit to its. 

 magnitude, and by producing the note long enough, I will 

 (how that a beat muft neceflarily enfue. Perhaps a wifh to 

 retain the Newtonian theory of the law of the undulations may. 

 have led him into thefe fuperfluous refinements, 



M 



unifons muft 

 produce beats 



