In reply to Hal Davis regarding the voicing machine.  As Hal says,
why has it taken so long to come up with a foot-operated wind supply
for voicing pipes?  This is a superb idea -- the perfect solution,
I would think.

I made a voicing machine some years ago for experimenting with violin
pipes.  This used a small electric motor and reduction belts, driving
a 4 inch x 10 inch bellow into a similar sized reservoir with springing
to give pressures up to 6 inches WC pressure.  This has three
finger-operated valves so that pipes can be balanced to one another.

The belts are always requiring adjustment; I was going to re-engineer
it but now, when I do, it will be foot operated.  Thanks to Hal for
a very good idea.

John Smith
Flitwick, UK