Re: absolute pressure

[Herbert H Gottlieb <herbgottlieb@JUNO.COM>]

On Wed, 05 Jun 2002 11:04:26 -0700 Bernard Cleyet <anngeorg@PACBELL.NET>
writes:
> > Why do they call it a "mercury" barometer?
> > as aposed to the original Torricelli barometer? (water)
> http://www.islandnet.com/~see/weather/history/barometerhistory1.htm
>
> Until the advent of S.S. electronics, neroid barometers were
> significantly more efficient (cost per performance) than the
> mechanical  ones (aneroid).

*** Please explain what you mean by the above sentence.

> Geologists use(d) aneroids for mapping. Their
> resolution is ~ one foot. (memory)  The pilot on this list can
> compare  this to his.  [What does he use now?]

*** Pilots are more likely to use either altimeters, which are
specially calibrated aneroid barometers, or radar devices.

> > Herb Gottlieb from New York City
> > (Where we have found ingenious ways to measure the heights of our
> > buildings with mercury barometers)