246 OF SOUND A\D HEARING. 



whether? (which sort of question in matters of this kind 

 has ruined all) but by the way, how far ? and that not by 

 arguments discursive, but by opposite experiments and 

 crucial instances. 



OF THE COMMUNICATION OF THR AIR PERCUSSED AND 

 ELIDED WITH THE AMBIENT A1K, AND BODIES, OK 

 THEIH SPIRITS. 



In the striking of a bell, the sound given by chiming 

 upon the bell with an hammer on the outside, and by the 

 tongue within, is of the same tone. So that the sound 

 yielded by the chiming upon the outside, cannot be gene 

 rated by the collision of the air, between the hammer and 

 the outside of the bell, since it is according to the concave 

 of the bell within. And if it were a flat plate of brass, and 

 not concave, the sound should, I think, be different. 



If there be a rift in a bell, it gives a hoarse sound, not 

 pleasant or grateful. 



It would be known how the thickness of the percussed 

 body may affect the sound, and how far forth : as if of the 

 same concave, one bell should be thicker, another thinner. 

 I have proved in a bell of gold, that it gave an excellent 

 sound, nothing worse, yea better, than a bell of silver or of 

 brass. But money of gold rings not so well as money of 

 silver. 



Empty casks yield a deep and resounding sound, full 

 ones a dull and dead sound. But in the viol, and the lute, 

 and other such, although the first percussion be between 

 the string and the exterior air, yet that air straight com 

 municates with the air in the belly, or concave of the viol 

 or lute. Wherefore in instruments of this kind is ever 

 some perforation made, that the outward air may commu 

 nicate with the confined air, without which the sound 

 would be dull and dead. 



Let there be a trial made of the nightingale-pipe, that it 

 be filled with oil, and not with water ; and let it be noted, 

 how much softer or more obtuse the sound shall be. 



When sound is created between the breath and the per 

 cussed air, as in a pipe, or flute, it is yet so produced, as it 

 hath some communication with the body of the flute, or 

 pipe. For there is one sound produced in a trumpet of 

 wood, another in one of brass; another, I judge, if the 

 trumpet were lined within, or perhaps even covered, on the 

 outside, with silk or cloth : one perchance if the trumpet 



