104 NATURAL HISTORY. 



that make recorders, &c. know this already : for 

 that they make them in sets : and likewise bell- 

 founders, in fitting the tune of their bells. So that 

 inquiry may save trial. Surely it hath been observed 

 by one of the ancients, that an empty barrel knocked 

 upon with the finger, giveth a diapason to the sound 

 of the like barrel full ; but how that should be I do 

 not well understand ; for that the knocking of a 

 barrel full or empty, doth scarce give any tone. 



187. There is required some sensible difference 

 in the proportion of creating a note, towards the 

 sound itself, which is the passive : and that it be not 

 too near, but at a distance. For in a recorder, the 

 three uppermost holes yield one tone ; which is a 

 note lower than the tone of the first three. And the 

 like, no doubt, is required in the winding or stopping 

 of strings. 



Experiments in consort touching exterior and interior 



sounds. 



There is another difference of sounds, which we 

 will call exterior and interior. It is not soft nor 

 loud : nor it is not base nor treble : nor it is not 

 musical nor immusical : though it be true, that there 

 can be no tone in an interior sound ; but on the 

 other side, in an exterior sound there may be both 

 musical and immusical. We shall therefore enu 

 merate them, rather than precisely distinguish them ; 

 though, to make some adumbration of what we mean, 

 the interior is rather an impulsion or contusion of 

 the air, than an elision or section of the same : so as 



