RadioBanter - View Single Post

April 28th 04, 08:08 PM

wrote:
I believe Pascal's law remains in effect in a thermometer, but
is overshadowed by other factors, including the design you mention,
the details of which I don't know.

Pascals law, just as any other natural law, always remains in effect.
The point is simply that a sealed column of liquid will NOT change
length by a factor of the square root of two at an inclination of 45
degrees. That was initially my issue with Cecil.

A barometer on the other hand is obviously not sealed. The weight of
the column of mercury is balanced against the weight of the atmosphere
acting on an open reservoir of mercury at the bottom of the column. The
reservoir will act to maintain the column at a constant vertical height
by adjusting the length of the column as a funtion of tilt angle. A
sealed column does not act that way.

I disagree that it's specious to point out that rather significant and
fundamental difference.

73, ac6xg