To answer Mr. Sanderson's question about the 'half Duo-Art' Steck,
with binary control only on the accompaniment vacuum supply:  This is
the normal configuration for a foot-pumped Duo-Art, common in the UK.
Is your instrument from England, where Steck was one of the most common
Aeolian brand names?

In the foot-pumped version, the pianolist controls the theme level by
pumping.  (The theme level is the full vacuum in the reservoir, which
is switched on by the accent perforations.)  A 'melody line' was printed
on the roll to guide the player in keeping the vacuum at the correct
level for when it is called for by the accents.

This was done because if there had been automatic control for both the
accompaniment and the theme level, the player would have had to keep
the piano pumped up to full vacuum at all times to 'anticipate' the
accompaniment digital instructions, an impossibly tiring effort.

All Duo-Art pianos can be said to be 'automated Themodist' players
(in the case of the pumped version, 'semi-automated').  They are back-
compatible with Themodist rolls, and work well with Themodist or plain
88 note rolls, once the pianolist has mastered the use of the hand
controls and foot pedals.

Douglas Henderson has published some interesting papers on how one does
this, on his web site newsletter:

http://www.wiscasset.net/artcraft/rollnews.htm

Richard Vance

 [ I'd sure like to have a special foot-pumped Themodist wherein the
 [ accompaniment level is always maintained at about 6 decibels down
 [ from the theme volume.  The normal Themodist has a fixed accomp
 [ level (set by the spring tension), and thus can't follow the
 [ pumping dynamics of the pianolist.  --  Robbie