Lesson xvin.] SOUND. 103 



galleries, than behind others. Our seats, rising 

 so little above each other, occasion this defect j 

 which would be remedied, could we have the seats 

 to rise their whole height above each other, as iu 

 the ancient theatres. 



Water has been little noticed with respect to 

 its conducting of sound ; but it has been lately- 

 found to conduct sound more than any other 

 body whatever. A conversation delivered- in no 

 very loud tone, has been distinctly heard, on 

 water, at the distance of a mile ; and a whisper 

 has been heard at the distance of more than two 

 hundred yards. 



Stone is sonorous, but gives a harsh disa- 

 greeable tone, unfavourable to music. Brick, in 

 respect to sound, has nearly the same properties 

 as stone. 



Wood is sonorous, conductive, and vibrative. Of 

 all materials, it produces a tone the most agreeable 

 and melodious; and it is, therefore, the fittest for 

 musical instruments, and for lining rooms and 

 theatres. 



Paint has been generally thought unfavourable 

 to sound, from its being so to musical instruments, 

 whose effects it entirely destroys. Musical instru- 

 ments mostly depend on the vibrative or tremulous 

 property of the material, which a body of colour 

 hardened in oil must very much alter : but we 

 should distinguish that this regards information 

 of sound, which may not altogether be the case in 

 the progress of it. 



A remarkable circumstance in the nature of 

 F 4 sounds, 



