(73) 
of Seconds, and two other kinds of Thirds, and of 
Sixths, and of Seveoihs. Bat among theie two are 
moft emiiimr, I e. the Tritme or fdfe fourth^ made of 
two Tones major ^ and one Tone minor ^ being as 45- to 
31, AnA ih^ falfe fifth, or Semidiapenre, made of a 
Fourth and Hemitone major ^ i.e. 64 1045. Thefe 
Difcords, as alfo the Seconds and Sevenths are notwith- 
{landing of great uft in Mufick for Delight when judi- 
cioufly ufed. He reckons feven of thefe within the 
Oilavey i. e, three Seconds, two Sevenths, and the Tri- 
tone and Secnidiapente. And as many alfo in the fe« 
cond and third Diapafons, All thefe Proportions he 
particularly explains, and flievvs how they arife and are 
produced. He next Obferves, that all Progreflions by 
Concords, except by Eighths, produce Difcord, as two 
Thirds wj/V, two Thirds minor^ two Fourths, two Fifths, 
two Sixths minor^ two Sixths majory to which may be 
added two Tones minor , and two Tones major. And 
upon this Account he Ihews the beft way how to have 
an Organ or Virginal tuned to make it more compre- 
henfive and accommodate to divers Cliffs, though it be 
not ftriftly true to any, by Tuning certain Keys^either a 
little higher, or a little lower than the due pitcb« 
In tl^ Eighth Chapter he fpeaks of Differences, or 
the feveral Intervals between any two Notes reduced to 
Proportion ; as a Fifth differs from a Fourth by a Tone 
major; that is, the Proportion of 3 to x is greater than 
the Proportion of 4 to 3 by the Proportion of 9 to 8. 
And fo of all other Proportions the Difference between 
any two of them is that which is here meant by Dif- 
ferences ; however thofe which he here treats of are ge- 
nerally le(s than a Tone, they are all eafily found by 
the Doftrine of Addition and Subftradiog of Propor- 
tions, according to which he has given one Table of 
true Diatonkk Intervals, and another of falfe Diato» 
nick Intervals, wherein a Comma or Diefis is oft found 
abound- 
