Denny Esterline wrote:
> I think the pendulum apparatus would be the easiest to produce, it's
> basically just a high precision frequency counter that can average over
> many cycles.

This is a little off topic, but I used this technique to make a very
accurate thermometer once for fun.  I deliberately used about a 1m thin
copper pipe with a mass on the end as the pendulum.  The thermal expansion
of the pipe changed the pendulum length, which made a surprisingly easy to
measure shift in the pendulum period.  In this case I used an ordinary
crystal as the time reference and assumed gravity was constant.  Holding all
this constant and trying to measure gravity instead seems like a few orders
of magnitude more difficult.

This thing was sensitive enough so that you could see the temperature go up
as you stood next to it.


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