How to choose Temperament? was Another Recital in 1/7 Comma

[A440A@AOL.COM]

 Bill Bremmer writes:

>It should be said that all of these Meantone temperaments are defined by
>the 
>Syntonic Comma, <snip>
>  The Syntonic Comma is the amount short of an
>octave  that you get when you tune 3 pure contiguous 3rds.  That 21.5 cents 
>(theoretical) difference, gap or shortfall is called the Comma.  

Greetings, 
    I must disagree.  
A pure M3 is 386 cents wide.  Three of these span a distance of 1158 cents.  
An octave is 1200 cents wide.     The difference between three Just 
contiguous thirds and an octave is a diesis, and it is approx. 41 cents.  
  A syntonic comma is the difference between four just fifths and two Just 
octaves. See Jorgensen, "Tuning", pg 777
Regards, 
Ed Foote RPT