At 04:28 PM 11/6/2010  -0700, neil n wrote:
>I'll look into that brand of stethescope David. Sounds like a useful
>thing to have. I have used a cardboard tube in the past (as I just did

The cardboard tube will tell you what's going on in the air near its
end.  The metal bar or stethoscope will tell you what's going on
inside the metal.

Yrs,
D
ps -- Lisle is the high-priced spread.  K-D may have one that's
cheaper and works ok.  ISTM I paid ~USD28 for mine.