of Strings and Rods i tXJ 



JiFth 5 afid one of iron or glafs, about four oftaves and a half 

 tone higher than the cokimn of air in an open pipe of the 

 feme leno;th. If one therefore had a fufficieutly long fcriea 

 of fuch fubftances, the velocity with which found is conveyed 

 through tin would be found to be 7800, through filver 9300, 

 through copper 12,500, through glafs and iron 17,500 Pans 

 feet in a fecond. The kinds of wood I have examined would 

 conduA found from about 11,000 to nearly 18,000, and 

 burnt pipe clay from about 10,000 to 12,000 feet in a fe- 

 cond. 



Profeflbr Wiinfch, in fome papers which he read before 

 the Academy of Berlin* in 1788 and 1789, made known 

 experiments to which he was led by Hook's Micrngraphia, 

 and from which he infers, that found moves with infinite; 

 velocity through hard bodies, or with the fame velocity as 

 light. It follows, however, from the experiments which 

 were made with a ferles of wooden laths not of conliderablc 

 length, tliat found was conduded through thefe fooner than 

 • through the air. 



Hard bodies, in regard to the ftrength with which they 

 convey found, feem to exceed air ; fo that we may coufe- 

 quently admit that air, though the moll common condutlor 

 of found, is however one of the word conduclors of it. If a 

 man holds one end of a flick in his teeth, and applies the other 

 to a founding body, he will clearly hear the found of it though 

 his ears be Itopped ; and in this manner two perfons, almolt 

 deaf, could hear all the notes of my euphon f, even in pia- 

 uillimo :j;. If one holds between tiie teeth a thread, to the 



end 



P.crlin 1793-4. 

 \ For an account of the Euphon fee Phil. Magazine, Vol. 11. p. 3 9'' 

 + About fifty years nt;o a merchant at Cleves named Joriffcn, who had 

 become almoft totally dLaf, fitting one day near a harpfichord while fomc 

 one was playing, and having a tohacco-pipc in his mouth, the bowl of 

 which rcfted accidentilly againll the body of the inftrument, he was agree- 

 ably and unexpeacdly liirprifed to hear all the tones in the moft dillinft 

 ni:»n!icr. By a little rcHedtion and pra(',ticc he agiin obtained the ufs of 



1 3 'I'is 



