stability of pitch raises

[Scott Jackson]

It's interesting to follow the discussion about pitch raises. It seems that some modern research 
just confirms what has been known for a long time.

>
>- ----- Original Message -----
>From: "Z! Reinhardt" <diskladame@provide.net>
>To: "Pianotech" <pianotech@ptg.org>
>Sent: Friday, August 31, 2001 12:22 AM
>Subject: Re: stability of pitch raises
>
>
> One person you might want to talk to is Doc Sanderson (Dr SAT himself) at
> Inventronics.  He has done research on the effects of doing a pitch raise
> "piecemeal" (start with a temperament, tune single strings, then pull in
> unisons) versus "brute force" (crank all pins from one end of the piano to
> the other).  If I remember correctly, he has found that the "brute force"
> method [my terminology] results in more stable tuning at pitch using a
> smaller overpull than would be necessary to do a "piecemeal" pitch raise.
> He may have an explanation for this phenomenon.
>

It seems this may have been recognised as early as 1917.
On page 227 of "Page Tuning and Allied Arts fifth edition", William Braid White says:

	"The object of pulling up the first time from the extreme bass, is to put on the 
additional stress beginning at the heaviest part of the iron plate. If the work be begun in the 
middle, the structure will at once act to equalize the new stresses and the pitch will drop as 
soon as it is reached."

So..........., nothing new!

Scott Jackson
Jurjens Pianos
Wollongong Australia