Recency of Equal Temperament's becoming nearly universal

I've discovered a reprinted volume of the Encyclopaedia of Music by John W.
Moore, published in 1854 (Boston, Cleveland, New York, and London) at the UC
San Diego music library. The encyclopedia contains a full article on the
pianoforte, and the description is consistent with that of a piano tuned to a
mean tone temperament. Contrasting the piano with the guitar, the author
writes: "The guitar is capable, in a small space, of the most heart-touching
expression; but then its tone is not fit to be heard from afar, even in a
theatre or concert room; besides, ITS STYLE OF HARMONY (in the best of hands)
is not (ital.) comme il faut, or perfectly according to severe counterpoint;
nor, strange as the assertion may seem, can it admit of alteration without
injuring the genius of the instrument. This is plain from a comparison of
Huerta's performance with that of the accomplished and scientific Sor." I.e. -
the guitar is (without adjustments not widely known of in 1854) constrained to
be in equal temperament, but the piano is not subject to that limitation.

I found nothing about tuning practices under entries for tuning, temperament,
etc., in that encyclopedia, but I found an entry under BEARING NOTES which
reads as follows:

"In the tuning of keyed instruments, harps, etc., bearing notes signify those
notes between which the most erroneous or highly tempered fifth is situate, on
which also the is said to be thrown. Many tuners begin at C, and
tune upwards through the progression of fifths, C, G, D, A, E, B, Gb, Db, and
Ab, and then stop and begin again at C, the octave above the former note, and
tune downwards, through the fifths F, Bb, and Eb, and thus the resulting fifth
Ab, Eb, produces ; owing to each fifth having been made
more or less flat than the system of twelve notes will bear, the sum> of all their errors or temperaments being the . Some
tuners are in the habit of throwing their into the fifth Ab, Db,
and others into that of Db, Gb, which last, as being nearest to the middle of
the whole progression of fifths, seems its most appropriate place for general
use."

The entry for DIASCHISMA reads:

DIASCHISMA. (From the Greek) An interval in the ancient music, forming the
half of a minor semitone.

The entry for SEMITONE reads:

SEMITONE. Half a tone; the smallest of all the intervals admitted in modern
music. There are two species of semitone; the major and the minor. The
semitone major is produced by rising a degree, as from G natural to A flat;
the semitone minor, by passing from a natural note to its sharp.

As the just intonation minor semitone is about 72 cents, this would make a
diaschisma about 36 cents, which is about the size of the wolf in quarter
comma mean tone temperament. I would infer from this entry that, as late as
1854 in the United States, mean tone temperaments, including quarter comma
were the ones in most widespread use for the piano and other keyboard
instruments.

Regarding Silbermann, it is my understanding that he is associated with a
"Silbermann temperament" which is essentially identical with sixth comma mean
tone temperament, which is about halfway between quarter comma mean tone
temperament (with just 5/4 thirds) and equal temperament with thirds sharp
from just by 13.7 cents. (the 1/6 comma MT third is sharp by about 7.2
cents).

I had my piano tuned first to sixth comma mean tone temperament last summer.
Putting it into that tuning caused its sound to be dramatically different than
the sound it had in equal temperament - more gently harmonious and strikingly
resonant - just a "different animal", hardly the same kind of musical
instrument as a piano in equal temperament. More recently I have been playing
a rented piano in quarter comma mean tone temperament. The sound of the
different piano in this latter tuning is again very different from the sound
either of equal temperament or sixth comma mean tone temperament - to my ears
a very beautiful sound - and to a number of others it was an amazing surprise
to hear a piano sounding as it does in mean tone temperament. Although I have
been working with just intonation music synthesis for nearly 20 years, I
myself was amazed to hear the sound of a piano in mean tone temperament and I
still have not gotten over this "discovery".

If I were to compare the sounds of the sixth comma mean tone piano and the
quarter comma mean tone piano, I'd say they both sound very beautiful and they
sound very different, one from another. I would think there was plenty of
room for pianos tuned both in 1/6 comma and quarter comma.

>Call me ignorant, but I have no idea what you guys are talking about. But
>I would like to learn. Any suggestions on a good information source?

Is any particular topic especially unclear?