After far too many interruptions and delays I have finally resumed
the restoration of my Melville Clark Solo Art Apollo expression piano.
Today I re-tubed the 88-note "main stack" and began to try and figure
out the proper tubing for the "solo stack".  Some of the original
tubing had long ago disintegrated and disappeared, but there was enough
left to get a good start.  I made a discovery that I cannot explain
however, and hope that somebody on MMDigest can offer some information.

There are 88 striking pneumatics in the "main stack" and 55 more in the
"solo stack", which is located behind the "main" stack and operates by
pushing up on the stickers in the piano action (as opposed to pushing
down directly on the keys for the main stack).

  88 + 55 = 143 striking pneumatics.

First difficulty:  There are only 134 holes in the tracker bar.
This made me think that some of the notes are tied together in octaves,
since some of the 134 holes are supposed to be used for the expression,
and Melville Clark bragged in advertising (I collect ads by his
company) that they could transpose into 8 keys, so I believe that not
every hole outside the 88 could be used up for expression or Solo
purposes.

I could not figure out how all the different notes would be activated.
If they could not be activated independently, it would rather defeat
the purpose of having them there in the first place.

Then I discovered another difficulty:  The 55 Solo pneumatics have only
36 brass nipples leading to them in the stack.  After cleaning away all
of the 'reside' deposited around the tubing nipples by the former
(rodent) inhabitants of the piano, I found that there are a number of
holes in line with the brass nipples that were clearly plugged at the
factory with dowels and finished over with the original shellac finish.

I took the covers off the pouch pneumatics and discovered that there
are 55 pouch pneumatics, but 10 of them at the treble end, and 9 on
the bass end, have screws set into the bleeds to plug them up and
render them inoperable.  These pneumatics are located perfectly in line
with the factory-plugged holes that would have had brass nipples
inserted.

There are also 55 valves for the Solo pneumatics.  The facings
(leather washers) show absolutely no evidence of wear on those 19
pneumatics -- they stand out very visibly as different from the 36
that _are_ tubed-in -- so it is impossible to believe that they were
ever operational and that somehow this disabling is a post-factory job.
The piano is unquestionably unrestored original.

It would have required great inventiveness and effort on somebody's
part to do this outside the factory, which would bring up the question
as to why they would ever want to.  If the piano were malfunctioning
somehow long ago, it would have required far less skill to repair
whatever the problem was than to contrive this type of 'solution' to
whatever problem somebody thought they were having.  If the system
were working fine, why go to so much effort to disable so much of it?

Does anyone have any idea why Melville Clark would have gone to the
trouble of installing all these extra pneumatic parts just to plug and
disable them before the piano ever left the factory?  I cannot imagine
why this would have been done.

It would seem that they knew these pneumatic parts would not be used
(no tracker bar tubing for them), so why even install them to begin
with?  The pouch and valve pneumatics are essential invisible to anyone
not disassembling the piano and could have been easily hidden from the
owner, but the 19 extra striking pneumatics that never moved would have
been potentially visible if anyone cared to look in the right place.

If anyone has any information that could shed some light on this for
me, I would greatly appreciate it.

Thank you and best regards,

Troy Taylor
Edmonds, Washington

 [ Melville Clark was known for continuously changing the design,
 [ which the shop foreman undoubtedly found maddening!  -- Robbie