Thanks for the links, Steve!
The second article includes the Ellis chart, which was done in 1880.
Notice how many times 432 appears on that chart - exactly none.
In the source references of my 432 article, I include a link to an updated version of Ellis' chart which goes beyond 1880. There are three references to 432 with only one of them being a standard set in Milan, Italy in 1881. By 1885, Italy had accepted a new international standard agreement of 435. Also, it should be noted that one of those three references, the one that says 432.54 is actually a mistake and should read 430.54 - so there's really only two times 432 is listed, one of which was an unadopted proposal in Belgium. (yes, I know, the chart does not include Verdi's unadopted proposal for 432, unless that was the Belgium proposal. And no, regardless of what the Schiller Institute says, Verdi did NOT write his operas in 432 "which was the standard of the time". 432 was not the standard of the time. 435 was the French standard, and later the Vienna agreed international European standard, and that is the pitch he wrote them for. Regardless of a prestigious sounding name like "The Schiller Institute" - they share some inaccurate information on this topic.)
Furthermore, and propagated by SI and others, 432 is NOT in French physicist and non-musician Joseph Sauveur's 'Scientific Pitch' (or 'Philosophical Pitch') tuning. 'A' is 430.54 in this system if using Equal Temperment and is 426.66 if using Perfect Intonation to calculate the scale. It is called 'Scientific' for one reason only: easy numbers! It is built on 'C' starting at 1 with mathematically 'easy' octaves of 2, 4, 8, 16, 32, 64, 128, 256, 512 etc....
Verdi did briefly propose 'Scientific Pitch' for orchestras and he also briefly proposed A432, without much success.
What I am not sure of is whether Verdi combined the two, using Pythagorean 5ths to arrive at A432 from C256. (Which I
am guessing that SI does.) I say I am not sure since I personally have seen no official evidence to support this idea.
If anyone has any legitimate information on this please post it here. The thing is, Verdi would have doubtlessly been
aware that the Pythagorean 5ths scale does not give good tuning for harmony and I doubt would have expected orchestras
to play with that intonation.
I am also not sure if the short-lived 432 Milan adoption in 1881 was a result of Verdi's efforts or not.
I like Ellis' guidelines for handling tuning forks!
1. Tuning forks should not be touched by the bare hand or carried in the pocket.
2. When a tuning fork is sharply struck, the blow causes heat and therefore slightly flattens the fork.
3. Tuning forks are tuned by filing which causes heat and unsettles the molecular structure of the metal. After filing a fork, it should rest for about a week and then be rechecked. It will often rise by several beats in ten seconds in the course of cooling and settling.
4. Tuning forks are damaged by wrenching & twisting the prongs which is usually caused by dropping the fork.
5. Rust will slightly flatten a tuning fork and is generally more serious at the bend than on the prongs. Modern forks are plated or blued to protect them from rust.
Ah yes, remember to wait a week before rechecking the tuning of your tuning fork.
And I've really got to stop wrenching and twisting the prongs. For me it usually happens when I use them to pry off the hubcaps on my car or chip ice off of the front steps in the winter. (Hey, it was sold to me as an 'all-purpose' tuning fork!)