(dp) 
SySefn of 8, corififting of 7 Interval?, or 8 Notes 
clufive, is called Diapafon, and every 0(9:ave or Syftem 
above or below it aicends or defcends by the fame In- 
tervals, Then he gives the Reafon why thty fo pfeafe 
the Eir, and this heftews to be from the more frequerit 
coincidence of their appropriate Vibrations. As the 
Unifons unite ia every Vibration being perfedly Kb- 
chrcn; 8tlis. every 2d. of the quicker, ^ths. every 3d, of 
the quicker, . 4ths. every 4th. of the quicker, 3d. majon 
or Ditons every 5th. minors every ^Jch, and tw'o , 
firings of eqaai bignefs and tenfioa wil! give thefe fn» 
tervals, if their lengths be in proportion to one anorher, 
as I to X, 2 to 3, 3 to 4, 4 to 5", and 5 to 6. Upon 
the occafion of the difference of 3d$, and the difference 
of 6ths, he difcourfes which of them may be more pro- 
perly made ufe of in movements of Confort-Mufick , 
but only it\ tranfitu^ as being not pertinent to his pre- 
fent Defign, but to avoid ambiguity of Name, he has 
given a Table both 6F the feveral Intervals, and atfo of 
the feverai Names of each Interval, pag, 66. 
In the Fifth Chapter he fpeaks fomewhat of Propor- 
tion in general, and then of three kinds of it ; Arith- 
metical, Geometrical, and Muficalwhich he in ftiort de- 
fines and explains : Then he explains the feverai Deno- 
minations of Geometrical Rations, as Multiplex, Super- 
particular, Superpartient, and then comes to (hew 
how this Doflrine is ufeful and applicable to Harmony 
and Mufick, and that the Philofophy thereof confifls in 
the Rations or Proportion of the Bodies, of the ^lotions 
and of the Intervals of Sound, in the very Coniernpla- 
tion of which there is no lefs pleafure^and fatisfk^tion 
than in the hearing it felf of good Mufick : The Rati- 
ons he fliews to be found by Mu'nplications and Divi- 
fions, and thereby the Progreffions and the Mediums 
may alfo be eafily reduced to be expreffible by whole 
Numbers. Thus^ adding of Rations is performed by 
L Mul- 
I 
