22 MEMOIRS?/ the 
fcale of mufick ffrom double C-fa-ut to C-fol-fa, in ak) the na- 
ture of the higher notes will plainly appear, Fisj. 12. Plate I. 
and thefe are all fet down in the table, only obterve, that the 
pricked notes are imperfe£t, not e>:a6^1y in tune, but a little flat- 
ter or iharper than the places where they Hand, according as/ or 
yis let over them. 
Here we may make two inquiries, i. "Whence it is, that the 
trumpet will perform no other notes (in that compafs) but only 
thofe in the table, which are ufually called by muficians trumpet- 
notes, 2. What is the reafon that the 7th, nth, 19th 'and 14th 
notes are out of tune, and the others exactly in tune. 
In this matter we may receive fome light from the trumpet- 
marine, an inftrument, tho* as unlike as poflible to the trumpet " 
in its frame, one being a wind inftrument, the other a mono- 
chord 5 yet it hath a wonderful agreement with it in its effe6l ; 
the found is lb like, as not to be eafily diftinguirned by the niceffc 
car, and, as it performs the very fame notes, io it hath the fame 
defed:s as a trumpet 5 for if the ftrings be ftopped in any part but 
liich as produces a trumpet-note, it yields a harfh and uncouth 
(not a mufical ) found. 
Let us therefore proceed to our firft enquiry, and examine 
what is the realbn that the trumpet marine will perform no other 
but the trumpet-notes : It is a known experiment of two unifbn 
ftrings, that upon ftriking one of them, the other moves 5 which 
probably proceeds from hence, that the impulfes of the air, 
which are made by one ftring, do more eafily fet another in mo- 
tion, which lies in a difpofition of having its vibrations fynchro- 
nical to them, than a third, whole motion would be crols : We 
may improve this a little farther, by obferving that a ftring will 
move not only at the ftriking of an unifon, but an 8th or 12th, 
tho' after a different manner : If an unifon be ftrnck, it makes 
one entire vibration in the whole ftring, and the motion is moft 
lenfibly in the middle m Fig. 13. for there the vibrations take 
the greateft fcope^ if an 8th be ftruck, it makes two vibrations 5 
and the point m Fig. 14. is in a manner quiefcent, and the moft 
fcnlible motion is at;/, ;/ 5 if a 12th be ftruck, then it makes three 
vibrations, and the greateft motion is at q^ m^ q Fig. 1 5. and hardly 
to be perceived at /?, /> ; {q that, in fliort, this experiment holds,, 
when any note 'vs. ftruck, which is an unilbn to half the ftring, and 
a 1 2th to a third part thereof; In this cafe (the vibrations of the 
equal parts of a ftring being fynchronical ) there is no contrariety 
in -the motion to hinder each other 5 whereas it is otherwife, if a 
note i^ unifon to 'S, Fig. i6'. that does not divide the ftring into 
equal 
