Damon Atchison asks about a design for a lock-and-cancel valve.  Durrell
Armstrong's Player Piano Company sells one, which looks from the
illustration like it is made out of two Wurlitzer unit blocks and some
channeling of no great complexity.  Anyone who understands pneumatic valve
operation could design his own.  All you need to do is have one Wurlitzer
or Lauter-Humana block (or similar channeling in a block of wood) arranged
so that when the "on" tube from the tracker bar opens to atmosphere,
tripping the valve, the valve by some pneumatic or mechanical action
maintains that "on" tube open to atmosphere via a teed connection.  The
cancel valve, when it is tripped by the "off" tube from the tracker bar
simply momentarily blocks the continuously-open-to- atmosphere connection
to block 1, causing block 1 to return to closed position and remain there
until another "on" signal starts the cycle over again.  I _love_ pneumatic
valves!

In another note, Damon asked us to fill in the blanks in this: Tickle The
Ivories, played by Walter H---er.  Our own Rob DeLand's roll catalog has
the answer: QRS Autograph Roll 100066 is "Tickle The Ivories", played by
Joe Collins, composed by Wallie Herzer.  The same catalog lists one other
roll composed by Wallie Herzer, but none played by him.  So far I have
come up cold on Damon's other mystery, in which he asks us to complete the
title: "When You Wore Wh------".  Monday I'll take a look in the ol'
copyright files.

 [ It might be "When You Wore What I Wore"(?), telling of two ladies
 [ who discover that they're wearing identical dresses ! -- Robbie