The latest issue of the Early Keyboard Journal, published by the SE
Historical Keyboard Society and the Midwestern HKS, contains a
translation of a tuning/maintenance manual for the fortepiano published
by Johann Lehmann in 1827. The introduction, translation and notes are by
Thomas McGeary.  Section 42, found on pp 90-91, contains an intriguing
description of an octave coupler invented by J-B Streicher in 1824.
 
To quote in part, "by the new contrivance--for whose invention a patent
was granted to the above-mentioned [inventor] and which in essence
consists of a very simple pedal-operated mechanism--an upper octave is
added to every note precisely so that one and the same key puts in motion
its own hammer and the hammer (not the key) of the next upper octave.
 
"By this means, the player will be in a position to execute with single
fingers the fastest, boldest octave passages, which otherwise would have
to be played with the outstretched hand, so that the most uncertain leaps
are now easy, and that, if one or both hands take chords, using the pedal
one can repeat thest chords an octave higher, like an echo.  The
simultaneous striking of the octaves makes every tone more distinct (as
with the octave register on the organ), and hence this pedal is suited
chiefly for those places that should make a strong, special effect.  And
one must only take care that an octave remains clear between the two
hands so that the octaves to the bass are not already being struck by the
right hand."
 
It is not quite clear to me what is meant by the allusions to 'leaps' and
'echos', but my main concern is to know whether Lehmann was describing a
mechanism built into an actual piano, or just copying promotional remarks
put out by the Streicher firm.  And if this device was actually
incorporated into the Streicher pianos, why didn't it catch on, or did
it, and if so, is its use called for in the piano music of the time?  One
thinks immediately of difficult passages of octave runs in the sonatas of
Beethoven and Schubert, but these antedate the Streicher invention I believe.
 
Walter Bishop