t66 



CATALOGUE. — ACU8TICS, SOURCES OF SOUND. 



♦Chladni on the propagation of sound. Gilb. 

 III. 159, 177, 182, 184. 



Its velocity in different mediums. 



Chladni infers from the longitudinal vibrations of different 

 substances, a velocity of 7800 feet in a second in tin, OSOO 

 in silver, 12500 in copper, 17500 in glass and iron, 1 lOOO 

 to 18000 in wood, and loooo to 12000 in tobacco pipes. 

 His observations are fully confirmed by calculations from 

 different grounds. According to the elasticity of fir, as 

 inferred from an experiment of Mr. Leslie, the velocity of 

 an impulse should be 17300. The velocity may be easily 

 calculated from the sound of a loose rod ; if the number of 

 vibrations of the gravest sound in a second be n, the velocity 



will be .973 — , I being the length, and d the depth in feet. 

 d 



From an experiment of this kind, I find the velocity 1 7700 

 in crown glass, and 11 800 in brass. 



Von Arnim on the propagation of sound. 



Gilb. III. 1G7. IV. 112. 

 Gough. Manch. M. V. fias. 



Observes, that sound does not diverge equally. 



Englefield and Young on the effect of sound 



on the barometer. Journ. R. f ., I. Repert. 



ii. I. HI. Nich. 8. II. 181. Gilb. XIV. 



214. 

 Biot on the effect of heat in thepropagalion 



of sound. B.Soc.Phil. n. 63. Journ. Phys. 



LV. 173. 



It will appear under the article Capacity for Heat, that 

 some of Dalton's experiments agree more nearly with Biot's 

 calculations than his own conclusions from others warrant- 

 ed us to suppose. See Journ. R. I., L 



At first sight, it might be imagined, that a loud sound 

 ought to be more accelerated by heat than a weak one ; 

 but, on a more accurate examination, we shall find that 

 the law of isochronism of small vibrations will remain un- 

 impaired. 



Parseval on the propagation of sound in all 

 directions. To be printed, S. E. 

 Ca»sini makes the velocity of sound 110? feet, Meyer 



JIGS, Miiller 1109, Pictet about 1130. 



See Vibrations of Fluids. 



Sound conveyed by pipes. See Hearing. 



Decay of Sound. 



The human voice has been heard more than ten miles at 

 Gibraltar. Derham. 



Echos. 



On an echo in Gloucester cathedral. Birch. 



I. 120. 

 Quesnet on an echo. A. P. II. 87- X. 127. 

 Grandi de sono. Ph. tr. 1709- XXVI. 270. 

 Echo from two towers. A. P. 1710. H. 18. 

 Southwell on echos. Ph. tr. 1746. XLIV. 



219. 



A building vrith projecting wings produced 60 repeti- 

 tions. 



Euler on echos. A. Berl. 1765. 335. 

 Guynet on an echo repeating 14 syllables. 



A. P. 1770. H. 23. 

 Actis on an echo at Girgenti. M. Tur. 1788. 



IV. App. 43. 



From the parabolic form of a church. 



An echo in Woodstock park repeats 17 syllables by day, 

 and 20 by night. An echo on the north side of Shipley 

 church in Sussex repeats 21 syllables. Cavallo, &om Plot 

 and Harris. 



Sources of Sound. 



Vibrations of Fluids. 



Mariotte on the sounds of the trumpet. A. 



P. I. 209. 

 Bernoulli on organ pipes. A. P. I762. 431. 



H. 170. 



E.xtr. Hauy Traite de Phys. I. 3l6. 

 Euler on the motion of air in pipes. N. C. 



Petr. XVI. 281. 



Equal and unequal, hyperbolical and conical. All shut 

 pipes are unmusical, except cylindrical ones. 



On the sounds of gases. Nich. III. 43. 

 Chladni on the tones of an organ pipe in 

 different gases. Ph. M. IV. 275. 



