[ Arlene F. Smart wrote in 041202 MMDigest: ]

> The valve box has three primary valves and two secondary valves.
> Five tubes come up from underneath.  The tracking pneumatic has
> two holes, rather than the usual three.

It sounds like you have a very early Duo-Art from around 1914.
They had a valve operated tracker, but in later years they changed it.
I believe that of the five valves in the box you describe, the two
secondaries (with a screw-on brass cover) are the Themodist primaries.
Two others are for the tracker.

The last one is likely to be a sustaining pedal primary but I am not
certain about this.  They eliminated the valves in the tracker because
a method was found to make them superfluous.  I believe that the signals
from the fingers at the side of the roll will go through a "cut out"
box before it hits the primary valve.  This way, the signals will be
cut out during reroll and the pneumatic will center itself to reduce
the possibility of roll damage.

It is possible that the fifth valve that I think is going to the damper
pedal will control the cut out box for the tracker.  I will be happy to
discuss this on the phone to help make it clearer: tel. 1-718-520-1443

Regards,
Randolph Herr