The hand lever on my Aeolian Pianola is labeled "Re-roll, Silent,
Play".  (There is no separate button for "Silence".)  The various
gears and linkages are adjusted such that when the lever is completely
to the right, in "Play" position, the right edge of the translating
small gear is almost coincident with the right edge of the large gear
affixed to the take-up spool shaft.

As the lever is gradually moved toward the left (and the translating
gear shaft moves to the right), the sliding valve on the air motor
governor moves to allow airflow to bypass the governed suction chamber,
so that the motor turns much faster than in "Play" mode; the player
action continues to play the notes.  This is "Play Fast Forward".

When the left edge of the translating small gear approximately
coincides with the left edge of the large gear on the take-up spool
shaft, the action cut-out valve operates, silencing the player action.
This is "Silent Fast Forward".  (On my player the lever is opposite
the "e" in "Silent".)

All further movement of the lever to the left, toward "Re-roll", simply
moves the small gear out of contact with the large gear, and then the
pin clutch engages the chain drive for "Re-roll".

Adjusting everything necessitates a fair amount of fiddling with the
position of the pin clutch on the translating shaft, the turnbuckle
adjustments of the linkages, and the position of the leather nuts on
the slide valves.

It might be necessary to reduce the thickness of the felt pieces at
each end of the slot in the keybed through which the lever moves,
so as to realize a bit more lever travel distance.  The resulting
extra modes, "Play Fast Forward" and "Silent Fast Forward", are worth
the effort spent adjusting.

Robbie Rhodes
Etiwanda CA