Hello MMD.  Before returning the microscope I mentioned recently
[090305 MMDigest] to its rightful owner (The Uni of Tasmania), I looked
at the Aeolian stack sitting in its never-touched condition on my
workbench.  I realized that I had the opportunity to measure the travel
of all 88 valves before they were disturbed.  I think I was possessed
by the same forces that cause someone to climb Mt. Everest or to crawl
from Greenbelt to Baltimore, pushing a peanut along with his nose.
It was indeed very tedious.  However, for the two or three people who
may want to know, here are the results, measured at 12" water vacuum:

  Mean Valve Travel : 0.041"
  Standard Deviation in the Mean : 0.0040"
  Maximum Observed Travel : 0.0542"
  Minimum Observed Travel : 0.0332"

The microscope has one advantage over a dial gage if you want to measure
valve travels in an undisturbed stack.  It has a working distance of
about 5", so it easily can see the movements of the odd-numbered valves
in the lower deck.  You can't do that with a dial gage.

What I did note was how economical Aeolian were with the length of
their valve stems.  In the 'off' state, some of them barely protruded
above their red fiber stem guides.  This suggests that, in choosing
replacement leather for the valve facings, one needs to select leather
for the bottom facing that is at least as thick as the original.  If
any thinner some valve stems will be in danger of jamming under the
upper stem guide.

I think I've now squeezed all possible blood from this particular
stone.

John Phillips in Hobart, Tasmania