Tuning Question

[Richard Brekne]

Hi Folks... gee...perhaps I get to stay in touch long enough this time to actually get a couple thoughts from you all on something.

I was doing some thinking on some of the neat little ways different techs have of checking out a tuning during the exams, and tried out one little test as part of a tuning. 
It is as follows. For any given note, the minor third above should beat just a bit quicker then the major 6th above that same note. Ok.... so in tuning the tenor and bass, 
moveing downwards note for note from the just finished temperament I tried simply comparing these two intervals and leaving the note to be tuned such that the Major 
6th above was just a tad bit slower then the minor 3rd. I didnt do any other checks.. just barely listened to the octave and whipped out the tenor / bass. Then I went 
back and checked. I was suprised that I  didnt really need to do much of anything. Really really even thirds and tenths all the way down. Best of all this was very easy 
to hear and judge.

So what I want to be certain of is just how valid this is... Is it always such over the entire range of the piano, and for every piano, that the minor third shall beat faster 
then the major sixth ?  If so is can the difference be expressed in some sort of percentage figure or the like. If there are exceptions then what and why?

Just musing as usal
Ric B